CN112703435B - Optical film, method for producing same, optical laminate, and liquid crystal display device - Google Patents
Optical film, method for producing same, optical laminate, and liquid crystal display deviceDownload PDFInfo
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- CN112703435B CN112703435BCN201980059082.8ACN201980059082ACN112703435BCN 112703435 BCN112703435 BCN 112703435BCN 201980059082 ACN201980059082 ACN 201980059082ACN 112703435 BCN112703435 BCN 112703435B
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- G02B5/3083—Birefringent or phase retarding elements
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C39/00—Shaping by casting, i.e. introducing the moulding material into a mould or between confining surfaces without significant moulding pressure; Apparatus therefor
- B29C39/14—Shaping by casting, i.e. introducing the moulding material into a mould or between confining surfaces without significant moulding pressure; Apparatus therefor for making articles of indefinite length
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
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- B29C41/00—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor
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- B29C41/12—Spreading-out the material on a substrate, e.g. on the surface of a liquid
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
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- B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
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- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
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- B—PERFORMING OPERATIONS; TRANSPORTING
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- B29C55/02—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets
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- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
- B29D11/00—Producing optical elements, e.g. lenses or prisms
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- C08F232/00—Copolymers of cyclic compounds containing no unsaturated aliphatic radicals in a side chain, and having one or more carbon-to-carbon double bonds in a carbocyclic ring system
- C08F232/08—Copolymers of cyclic compounds containing no unsaturated aliphatic radicals in a side chain, and having one or more carbon-to-carbon double bonds in a carbocyclic ring system having condensed rings
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- C08F8/04—Reduction, e.g. hydrogenation
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- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
- C08J5/18—Manufacture of films or sheets
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- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
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- C08L45/00—Compositions of homopolymers or copolymers of compounds having no unsaturated aliphatic radicals in side chain, and having one or more carbon-to-carbon double bonds in a carbocyclic or in a heterocyclic ring system; Compositions of derivatives of such polymers
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- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
- G02B1/04—Optical elements characterised by the material of which they are made; Optical coatings for optical elements made of organic materials, e.g. plastics
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/30—Polarising elements
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/30—Polarising elements
- G02B5/3025—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state
- G02B5/3033—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state in the form of a thin sheet or foil, e.g. Polaroid
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- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
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- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/133528—Polarisers
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
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Abstract
Translated fromChineseDescription
Translated fromChinese技术领域technical field
本发明涉及一种光学膜及其制造方法、光学层叠体以及液晶显示装置。The present invention relates to an optical film, a method for producing the same, an optical laminate, and a liquid crystal display device.
背景技术Background technique
一直以来，已知有使用热塑性树脂形成的光学膜。例如，在专利文献1～5中，记载了使用热塑性降冰片烯系树脂形成的光学膜。Conventionally, optical films formed using thermoplastic resins are known. For example, Patent Documents 1 to 5 describe optical films formed using thermoplastic norbornene-based resins.
现有技术文献prior art literature
专利文献patent documents
专利文献1：日本特开2005-043740号公报；Patent Document 1: Japanese Patent Laid-Open No. 2005-043740;
专利文献2：日本特开2006-235085号公报；Patent Document 2: Japanese Patent Laid-Open No. 2006-235085;
专利文献3：日本特开2006-327112号公报；Patent Document 3: Japanese Patent Laid-Open No. 2006-327112;
专利文献4：日本特开2008-114369号公报；Patent Document 4: Japanese Patent Laid-Open No. 2008-114369;
专利文献5：日本特开2003-238705号公报。Patent Document 5: Japanese Patent Laid-Open No. 2003-238705.
发明内容Contents of the invention
发明要解决的问题The problem to be solved by the invention
近年来，在应用于液晶显示装置等图像显示装置的光学膜中，要求延迟的显现性优异，特别要求厚度方向的延迟Rth的显现性优异的膜。具体而言，要求该光学膜的单位厚度的厚度方向的延迟Rth大的光学膜。作为使用由现有的热塑性树脂形成的膜来得到单位厚度的厚度方向的延迟Rth大的光学膜的方法，考虑以高拉伸倍率进行拉伸的方法。然而，以高拉伸倍率进行拉伸得到的光学膜存在取向角精度降低的倾向。In recent years, optical films used in image display devices such as liquid crystal display devices have been required to exhibit excellent retardation, especially films excellent in retardation Rth in the thickness direction. Specifically, an optical film having a large retardation Rth in the thickness direction per unit thickness of the optical film is required. As a method of obtaining an optical film having a large retardation Rth in the thickness direction per unit thickness using a film formed of a conventional thermoplastic resin, a method of stretching at a high draw ratio is conceivable. However, an optical film obtained by stretching at a high draw ratio tends to lower the orientation angle accuracy.
此外，有时会在各种环境下使用图像显示装置，例如可能在高温环境下使用。因此，要求光学膜具有高耐热性。因此，当着眼于厚度方向的延迟Rth时，要求即使在高温环境下也能够抑制其厚度方向的延迟Rth的变化。In addition, image display devices are sometimes used in various environments, and may be used in high-temperature environments, for example. Therefore, optical films are required to have high heat resistance. Therefore, when focusing on the retardation Rth in the thickness direction, it is required to suppress the change in the retardation Rth in the thickness direction even under a high-temperature environment.
本发明是鉴于上述问题而提出的，因此本发明的目的在于提供一种光学膜及其制造方法、以及包含上述光学膜的光学层叠体和液晶显示装置，上述光学膜使用热塑性降冰片烯系树脂形成、单位厚度的厚度方向的延迟Rth大，取向角精度高且能够抑制高温环境下厚度方向的延迟Rth的变化。The present invention has been made in view of the above problems, and therefore an object of the present invention is to provide an optical film, a method for producing the same, an optical laminate including the above-mentioned optical film, and a liquid crystal display device, and the above-mentioned optical film uses a thermoplastic norbornene-based resin Formation and retardation Rth in the thickness direction per unit thickness are large, the orientation angle accuracy is high, and variations in retardation Rth in the thickness direction can be suppressed under a high-temperature environment.
用于解决问题的方案solutions to problems
发明人为了解决上述问题而进行了深入研究。结果，发明人发现，通过使用具有规定范围的玻璃化转变温度Tg且在以规定的条件进行拉伸的情况下显现规定的双折射ΔnR的树脂作为热塑性降冰片烯系树脂，能够制造单位厚度的厚度方向的延迟大、取向角精度高、且耐热性优异的光学膜，从而完成了本发明。The inventors conducted intensive research to solve the above-mentioned problems. As a result, the inventors found that by using a resin having a glass transition temperature Tg in a predetermined range and exhibiting a predetermined birefringence ΔnR when stretched under predetermined conditions as a thermoplastic norbornene-based resin, it is possible to manufacture The optical film which has a large retardation in the thickness direction, a high orientation angle precision, and excellent heat resistance has completed the present invention.
即，本发明包含下述内容。That is, the present invention includes the following matters.
[1]一种光学膜，其是使用包含降冰片烯系聚合物的热塑性降冰片烯系树脂形成的，[1] An optical film formed using a thermoplastic norbornene-based resin containing a norbornene-based polymer,
上述热塑性降冰片烯系树脂的玻璃化转变温度Tg满足下述式(1)，The glass transition temperature Tg of the thermoplastic norbornene-based resin satisfies the following formula (1),
在Tg+15℃、在对上述热塑性降冰片烯系树脂实施1分钟自由端单轴拉伸至1.5倍的情况下，上述热塑性降冰片烯系树脂显现的双折射ΔnR满足下述式(2)，The birefringence ΔnR exhibited by the thermoplastic norbornene-based resin satisfies the following formula (2 ),
上述光学膜的厚度方向的延迟Rth和上述光学膜的厚度d满足下述式(3)。The retardation Rth in the thickness direction of the optical film and the thickness d of the optical film satisfy the following formula (3).
(1)Tg≥110℃(1) Tg≥110℃
(2)ΔnR≥0.0025(2) ΔnR ≥ 0.0025
(3)Rth/d≥3.5×10-3(3) Rth/d≥3.5×10-3
[2]根据[1]所述的光学膜，其中，上述降冰片烯系聚合物的分子量分布为2.4以下。[2] The optical film according to [1], wherein the norbornene-based polymer has a molecular weight distribution of 2.4 or less.
[3]根据[1]或[2]所述的光学膜，其中，上述降冰片烯系聚合物选自包含25重量％以上四环十二碳烯系单体的单体的聚合物及其氢化物，[3] The optical film according to [1] or [2], wherein the norbornene-based polymer is selected from polymers containing 25% by weight or more of tetracyclododecene-based monomers and polymers thereof. Hydride,
上述四环十二碳烯系单体选自四环十二碳烯、以及四环十二碳烯的环结合了取代基的四环十二碳烯衍生物。The above-mentioned tetracyclododecene-based monomer is selected from the group consisting of tetracyclododecene and tetracyclododecene derivatives in which substituents are bonded to the ring of tetracyclododecene.
[4]根据[1]～[3]中任一项所述的光学膜，其中，上述光学膜的光弹性系数为8Brewster以下。[4] The optical film according to any one of [1] to [3], wherein the photoelastic coefficient of the optical film is 8 Brewster or less.
[5]根据[1]～[4]中任一项所述的光学膜，其中，上述光学膜的面内延迟Re为40nm以上且80nm以下。[5] The optical film according to any one of [1] to [4], wherein the in-plane retardation Re of the optical film is not less than 40 nm and not more than 80 nm.
[6]一种光学膜的制造方法，其为[1]～[5]中任一项所述的光学膜的制造方法，[6] A method for producing an optical film, which is the method for producing an optical film according to any one of [1] to [5],
上述制造方法包含将上述热塑性降冰片烯系树脂通过挤出成型法或溶液浇铸法(solution casting method)进行成型。The above-mentioned production method includes molding the above-mentioned thermoplastic norbornene-based resin by an extrusion molding method or a solution casting method (solution casting method).
[7]一种光学层叠体，其具有偏振片和[1]～[5]中任一项所述的光学膜。[7] An optical laminate comprising a polarizing plate and the optical film according to any one of [1] to [5].
[8]一种液晶显示装置，其具有[7]所述的光学层叠体。[8] A liquid crystal display device comprising the optical laminate according to [7].
发明效果Invention effect
根据本发明，能够提供一种使用热塑性降冰片烯系树脂形成、单位厚度的厚度方向的延迟Rth大、并且取向角精度高且能够抑制高温环境下厚度方向的延迟Rth的变化的光学膜及其制造方法、以及包含上述光学膜的光学层叠体和液晶显示装置。According to the present invention, it is possible to provide an optical film which is formed using a thermoplastic norbornene-based resin, has a large retardation Rth in the thickness direction per unit thickness, has high orientation angle accuracy, and can suppress changes in the retardation Rth in the thickness direction under a high-temperature environment, and the same. A production method, an optical laminate comprising the above-mentioned optical film, and a liquid crystal display device.
具体实施方式Detailed ways
以下，示出实施方式和例示物对本发明进行详细地说明。但是，本发明并不限定于以下示出的实施方式和例示物，在不脱离本发明的请求的范围及与其同等的范围的范围内可以任意地变更实施。Hereinafter, the present invention will be described in detail by showing embodiments and examples. However, the present invention is not limited to the embodiments and illustrations shown below, and can be implemented with arbitrary changes within a range that does not depart from the scope of the claims of the present invention and a range equivalent thereto.
在以下的说明中，只要没有另外说明，膜的面内延迟Re为Re＝(nx-ny)×d所表示的值。此外，只要没有另外说明，膜的厚度方向的延迟Rth为Rth＝[{(nx+ny)/2}-nz]×d所表示的值。在此，nx表示垂直于膜的厚度方向的方向(面内方向)中示出最大折射率的方向的折射率。ny表示在上述面内方向中与nx方向正交的方向的折射率。nz表示厚度方向的折射率。d表示膜的厚度。只要没有另外说明，测定波长为550nm。In the following description, unless otherwise stated, the in-plane retardation Re of the film is a value represented by Re=(nx-ny)×d. In addition, unless otherwise stated, the retardation Rth in the thickness direction of the film is a value represented by Rth=[{(nx+ny)/2}−nz]×d. Here, nx represents a refractive index in a direction (in-plane direction) perpendicular to the thickness direction of the film in a direction showing a maximum refractive index. ny represents the refractive index in the direction perpendicular to the nx direction among the above in-plane directions. nz represents the refractive index in the thickness direction. d represents the thickness of the film. Unless otherwise stated, the measurement wavelength is 550 nm.
在以下的说明中，“长条”的膜是指相对于膜的宽度具有5倍以上长度的膜，优选具有10倍或其以上的长度，具体而言是指具有可卷绕成卷状而保管或运送的程度的长度的膜。膜的长度相对于宽度的比例的上限没有特别限定，例如可为100000倍以下。In the following description, a "long" film refers to a film having a length of 5 times or more, preferably 10 times or more, with respect to the width of the film. The length of the film of the degree of storage or transportation. The upper limit of the ratio of the length to the width of the film is not particularly limited, and may be, for example, 100000 times or less.
在以下的说明中，只要没有另外说明，“偏振片”不仅包含刚性的构件，也包含例如树脂制的膜这样的具有可挠性的构件。In the following description, unless otherwise stated, a "polarizing plate" includes not only rigid members but also flexible members such as resin films.
[1.光学膜的概要][1. Outline of optical film]
本发明的一个实施方式的光学膜为使用热塑性降冰片烯系树脂形成的膜。上述热塑性降冰片烯系树脂包含降冰片烯系聚合物。而且，本实施方式的光学膜满足下述第一～第三的要件。An optical film according to one embodiment of the present invention is a film formed using a thermoplastic norbornene-based resin. The thermoplastic norbornene-based resin includes a norbornene-based polymer. And the optical film of this embodiment satisfies the following first to third requirements.
第一，热塑性降冰片烯系树脂的玻璃化转变温度Tg满足下述式(1)。First, the glass transition temperature Tg of the thermoplastic norbornene-based resin satisfies the following formula (1).
(1)Tg≥110℃(1) Tg≥110℃
第二，热塑性降冰片烯系树脂的评价双折射ΔnR满足下述式(2)。在此，评价双折射表示：在对某材料以比该材料的玻璃化转变温度高15℃的拉伸温度、实施1分钟自由端单轴拉伸至1.5倍的情况下显现的双折射。Second, the evaluated birefringence ΔnR of the thermoplastic norbornene-based resin satisfies the following formula (2). Here, the evaluation of birefringence means the birefringence that appears when a certain material is stretched 1.5 times free-end uniaxially for 1 minute at a stretching temperature 15° C. higher than the glass transition temperature of the material.
(2)ΔnR≥0.0025(2) ΔnR ≥ 0.0025
第三，光学膜的厚度方向的延迟Rth与光学膜的厚度d满足下述式(3)。Third, the retardation Rth in the thickness direction of the optical film and the thickness d of the optical film satisfy the following formula (3).
(3)Rth/d≥3.5×10-3(3) Rth/d≥3.5×10-3
满足上述第一～第三的要件的本实施方式的光学膜如式(3)所表示的那样，单位厚度d的厚度方向的延迟Rth大。此外，该光学膜在高温环境下能够抑制厚度方向的延迟Rth的变化。进而，该光学膜具有如上所述与厚度d相比大的厚度方向的延迟Rth、且能够实现高取向角精度。The optical film of the present embodiment that satisfies the above-mentioned first to third requirements has a large retardation Rth in the thickness direction per unit thickness d, as represented by the formula (3). In addition, the optical film can suppress a change in retardation Rth in the thickness direction under a high-temperature environment. Furthermore, this optical film has retardation Rth in the thickness direction larger than thickness d as mentioned above, and can realize high orientation angle precision.
[2.热塑性降冰片烯系树脂][2. Thermoplastic norbornene-based resin]
热塑性降冰片烯系树脂为包含降冰片烯系聚合物的热塑性树脂。降冰片烯系聚合物为包含使降冰片烯系单体聚合、根据需要进一步进行氢化而得到的结构的聚合物。因此，降冰片烯系聚合物通常包含选自使降冰片烯系单体聚合而得到的重复结构和将上述重复结构氢化而得到的结构中的一种以上的结构。在这样的降冰片烯系聚合物中，可包含例如：降冰片烯系单体的开环聚合物、降冰片烯系单体与任意单体的开环共聚物、以及它们的氢化物；降冰片烯系单体的加成聚合物、降冰片烯系单体与任意单体的加成共聚物、以及它们的氢化物。此外，热塑性降冰片烯系树脂包含的降冰片烯系聚合物可以为一种、也可以为两种以上。The thermoplastic norbornene-based resin is a thermoplastic resin containing a norbornene-based polymer. The norbornene-based polymer is a polymer having a structure obtained by polymerizing a norbornene-based monomer and further hydrogenating it if necessary. Therefore, a norbornene-based polymer usually contains one or more structures selected from a repeating structure obtained by polymerizing a norbornene-based monomer and a structure obtained by hydrogenating the repeating structure. Such norbornene-based polymers include, for example, ring-opening polymers of norbornene-based monomers, ring-opening copolymers of norbornene-based monomers and arbitrary monomers, and hydrogenated products thereof; Addition polymers of norbornene-based monomers, addition copolymers of norbornene-based monomers and optional monomers, and hydrogenated products thereof. In addition, the norbornene-based polymer contained in the thermoplastic norbornene-based resin may be one kind, or two or more kinds.
降冰片烯系单体为在分子内包含降冰片烯结构的单体。作为该降冰片烯系单体，可举出例如：双环[2.2.1]庚-2-烯(常用名：降冰片烯)、三环[4.3.0.12,5]癸-3,7-二烯(常用名：双环戊二烯)、四环[4.4.0.12,5.17,10]十二碳-3-烯(常用名：四环十二碳烯)等不包含芳香环结构的降冰片烯系单体；5-苯基-2-降冰片烯、5-(4-甲基苯基)-2-降冰片烯、5-(1-萘基)-2-降冰片烯、9-(2-降冰片烯-5-基)-咔唑等具有芳香族取代基的降冰片烯系单体；1,4-甲桥-1,4,4a,4b,5,8,8a,9a-八氢芴、1,4-甲桥-1,4,4a,9a-四氢芴(常用名：甲桥四氢芴)、1,4-甲桥-1,4,4a,9a-四氢二苯并呋喃、1,4-甲桥-1,4,4a,9a-四氢咔唑、1,4-甲桥-1,4,4a,9,9a,10-六氢蒽、1,4-甲桥-1,4,4a,9,10,10a-六氢菲等在多环稠合结构中包含降冰片烯环结构和芳香环结构的降冰片烯系单体；以及这些化合物的衍生物(例如、环上具有取代基的化合物)等。A norbornene-based monomer is a monomer containing a norbornene structure in a molecule. Examples of the norbornene-based monomer include bicyclo[2.2.1]hept-2-ene (common name: norbornene), tricyclo[4.3.0.12,5 ]dec-3,7- Diene (common name: dicyclopentadiene), tetracyclo[4.4.0.12,5 .17,10 ]dodeca-3-ene (common name: tetracyclododecene), etc. do not contain aromatic rings Structured norbornene-based monomers; 5-phenyl-2-norbornene, 5-(4-methylphenyl)-2-norbornene, 5-(1-naphthyl)-2-norbornene Norbornene-based monomers with aromatic substituents such as alkenes and 9-(2-norbornen-5-yl)-carbazole; 1,4-methylbridge-1,4,4a,4b,5,8 ,8a,9a-Octahydrofluorene, 1,4-Abridged-1,4,4a,9a-Tetrahydrofluorene (common name: Abridged Tetrahydrofluorene), 1,4-Abridged-1,4,4a ,9a-tetrahydrodibenzofuran, 1,4-methylbridge-1,4,4a,9a-tetrahydrocarbazole, 1,4-methylbridge-1,4,4a,9,9a,10-six Hydrogen anthracene, 1,4-methylbridge-1,4,4a,9,10,10a-hexahydrophenanthrene and other norbornene-based monomers containing norbornene ring structure and aromatic ring structure in polycyclic condensed structure ; and derivatives of these compounds (for example, compounds having substituents on the ring), etc.
作为取代基，可举出例如：甲基、乙基、丙基、异丙基等烷基；亚烷基；烯基；极性基团等。作为极性基团，可举出例如杂原子、或具有杂原子的原子团等。作为杂原子，可举出例如氧原子、氮原子、硫原子、硅原子、卤原子等。作为极性基团的具体例子，可举出：氟基、氯基、溴基、碘基等卤素基团；羧基；羰氧基羰基；环氧基；羟基；氧基；烷氧基；酯基；硅烷醇基；甲硅烷基；氨基；腈基；磺酸基；氰基；酰胺基；酰亚胺基等。取代基的个数可以为一个、也可以为两个以上。此外，两个以上的取代基的种类可以相同、也可以不同。但是，从得到饱和吸水率低、耐湿性优异的光学膜的观点出发，降冰片烯系单体优选极性基团的量少，更优选不具有极性基团。Examples of substituents include alkyl groups such as methyl groups, ethyl groups, propyl groups, and isopropyl groups; alkylene groups; alkenyl groups; polar groups, and the like. As a polar group, a hetero atom, or the atomic group which has a hetero atom, etc. are mentioned, for example. As a hetero atom, an oxygen atom, a nitrogen atom, a sulfur atom, a silicon atom, a halogen atom, etc. are mentioned, for example. Specific examples of polar groups include halogen groups such as fluorine, chlorine, bromine, and iodine; carboxyl; carbonyloxycarbonyl; epoxy; hydroxyl; oxy; alkoxy; esters silanol group; silyl group; amino group; nitrile group; sulfonic acid group; cyano group; amido group; imide group, etc. The number of substituents may be one, or two or more. In addition, the types of two or more substituents may be the same or different. However, from the viewpoint of obtaining an optical film having a low saturated water absorption rate and excellent moisture resistance, the norbornene-based monomer preferably has a small amount of polar groups, and more preferably has no polar groups.
降冰片烯系单体可以单独使用一种、也可以将两种以上以任意比率组合使用。The norbornene-based monomers may be used alone or in combination of two or more in arbitrary ratios.
上述降冰片烯系单体的具体种类和聚合比希望以得到具有期望的玻璃化转变温度Tg和评价双折射ΔnR的热塑性降冰片烯系树脂的方式进行选择。通常降冰片烯系聚合物的玻璃化转变温度和双折射显现性依赖于作为该降冰片烯系聚合物的原料的降冰片烯系单体的种类和聚合比。因此，通过适当地调节降冰片烯系单体的种类和聚合比，能够调节降冰片烯系聚合物的玻璃化转变温度和双折射显现性，因此能够将包含该降冰片烯系聚合物的热塑性降冰片烯系树脂的玻璃化转变温度Tg和评价双折射ΔnR调节至满足式(1)和式(2)。Specific types and polymerization ratios of the above-mentioned norbornene-based monomers are desirably selected so as to obtain a thermoplastic norbornene-based resin having a desired glass transition temperature Tg and an estimated birefringence ΔnR. Generally, the glass transition temperature and birefringence development of a norbornene-based polymer depend on the type and polymerization ratio of a norbornene-based monomer that is a raw material of the norbornene-based polymer. Therefore, by appropriately adjusting the type and polymerization ratio of the norbornene-based monomer, the glass transition temperature and birefringence development of the norbornene-based polymer can be adjusted, and thus the thermoplasticity of the norbornene-based polymer can be adjusted. The glass transition temperature Tg and the evaluation birefringence ΔnR of the norbornene-based resin are adjusted to satisfy the formulas (1) and (2).
从增大降冰片烯系聚合物的玻璃化转变温度和双折射显现性、容易地得到玻璃化转变温度Tg和评价双折射ΔnR大的热塑性降冰片烯系树脂的观点出发，优选使用四环十二碳烯系单体作为降冰片烯系单体。因此，降冰片烯系聚合物优选选自包含四环十二碳烯系单体的单体的聚合物及其氢化物。这样的降冰片烯系聚合物通常包含选自使四环十二碳烯系单体聚合而得到的重复结构、以及将上述重复结构氢化而得到的结构中的一种以上的结构(以下，有时酌情称为“四环十二碳烯系结构”。)。From the viewpoint of increasing the glass transition temperature and birefringence development of norbornene-based polymers, easily obtaining the glass transition temperature Tg, and evaluating a thermoplastic norbornene-based resin with a large birefringence ΔnR , it is preferable to use a tetracyclic resin. The dodecene-based monomer was used as the norbornene-based monomer. Therefore, the norbornene-based polymer is preferably selected from polymers of monomers containing tetracyclododecene-based monomers and hydrogenated products thereof. Such norbornene-based polymers generally contain one or more structures selected from repeating structures obtained by polymerizing tetracyclododecene-based monomers and structures obtained by hydrogenating the repeating structures (hereinafter, sometimes It is referred to as "tetracyclododecene-based structure" as appropriate.).
四环十二碳烯系单体表示选自四环十二碳烯和四环十二碳烯衍生物中的单体。四环十二碳烯衍生物是指具有在四环十二碳烯的环上结合了取代基的结构的化合物。取代基的个数可以为一个、也可以为两个以上。此外，两个以上的取代基的种类可以相同、也可以不同。作为优选的四环十二碳烯衍生物，可举出例如8-亚乙基-四环[4.4.0.12,5.17,10]-十二碳-3-烯(常用名：亚乙基四环十二碳烯)、8-乙基-四环[4.4.0.12,5.17,10]-十二碳-3-烯、8-乙氧基羰基四环[4.4.0.12,5.17,10]-3-十二碳烯、8-甲基-8-甲氧基羰基四环[4.4.0.12,5.17,10]-3-十二碳烯等。四环十二碳烯系单体可以单独使用一种、也可以将两种以上组合使用。The tetracyclododecene-based monomer means a monomer selected from tetracyclododecene and tetracyclododecene derivatives. The tetracyclododecene derivative refers to a compound having a structure in which a substituent is bonded to a tetracyclododecene ring. The number of substituents may be one, or two or more. In addition, the types of two or more substituents may be the same or different. As preferred tetracyclic dodecene derivatives, for example, 8-ethylene-tetracyclo[4.4.0.12,5 .17,10 ]-dodeca-3-ene (common name: ethylene ethyltetracyclododecene), 8-ethyl-tetracyclo[4.4.0.12,5 .17,10 ]-dodeca-3-ene, 8-ethoxycarbonyltetracyclo[4.4. 0.12,5 .17,10 ]-3-dodecene, 8-methyl-8-methoxycarbonyltetracyclo[4.4.0.12,5 .17,10 ]-3-dodecene ene etc. Tetracyclododecene-based monomers may be used alone or in combination of two or more.
相对于100重量％的作为降冰片烯系聚合物的原料的单体的总量，其所包含的四环十二碳烯系单体的比例(聚合比)优选为25重量％以上，更优选为27重量％以上，特别优选为29重量％以上，优选为60重量％以下，更优选为55重量％以下，特别优选为50重量％以下。在四环十二碳烯系单体的聚合比在上述范围的情况下，能够增大降冰片烯系聚合物的玻璃化转变温度和双折射显现性，因此能够容易地将热塑性降冰片烯系树脂的玻璃化转变温度Tg和评价双折射ΔnR控制在式(1)和式(2)的范围。The ratio (polymerization ratio) of the tetracyclododecene-based monomer contained therein is preferably 25% by weight or more, more preferably It is 27% by weight or more, particularly preferably 29% by weight or more, preferably 60% by weight or less, more preferably 55% by weight or less, particularly preferably 50% by weight or less. When the polymerization ratio of the tetracyclododecene-based monomer is in the above range, the glass transition temperature and birefringence development of the norbornene-based polymer can be increased, so that the thermoplastic norbornene-based The glass transition temperature Tg of the resin and the evaluation birefringence ΔnR are controlled within the ranges of formula (1) and formula (2).
通常，来自某单体的重复结构(单体单元)在降冰片烯系聚合物中的比例与该单体在全部单体中的比例(聚合比)一致。因此，通常四环十二碳烯系结构在降冰片烯系聚合物中的比例与四环十二碳烯系单体相对于单体的总量的聚合比一致。因此，四环十二碳烯系结构相对于100重量％的降冰片烯系聚合物的比例优选处于与上述四环十二碳烯系单体的聚合比相同的范围。Usually, the ratio of the repeating structure (monomer unit) derived from a certain monomer in the norbornene-based polymer corresponds to the ratio of the monomer in all monomers (polymerization ratio). Therefore, generally, the ratio of the tetracyclododecene-based structure in the norbornene-based polymer corresponds to the polymerization ratio of the tetracyclododecene-based monomer to the total amount of monomers. Therefore, the ratio of the tetracyclododecene-based structure to 100% by weight of the norbornene-based polymer is preferably within the same range as the polymerization ratio of the aforementioned tetracyclododecene-based monomer.
进而，从增大降冰片烯系聚合物的玻璃化转变温度和双折射显现性、容易地得到玻璃化转变温度Tg和评价双折射ΔnR大的热塑性降冰片烯系树脂的观点出发，优选使用双环戊二烯系单体作为降冰片烯系单体。因此，降冰片烯系聚合物优选选自包含双环戊二烯系单体的单体的聚合物及其氢化物。这样的降冰片烯系聚合物通常包含选自使双环戊二烯系单体聚合而得到的重复结构和将上述重复结构氢化而得到的结构中的一种以上的结构(以下，有时酌情称为“双环戊二烯系结构”。)。Furthermore, from the viewpoint of increasing the glass transition temperature and birefringence development of the norbornene-based polymer, easily obtaining the glass transition temperature Tg, and evaluating a thermoplastic norbornene-based resin with a large birefringence ΔnR, it is preferable to use a bicyclic resin. The pentadiene-based monomer was used as the norbornene-based monomer. Therefore, the norbornene-based polymer is preferably selected from polymers of monomers containing dicyclopentadiene-based monomers and hydrogenated products thereof. Such norbornene-based polymers generally contain one or more structures selected from repeating structures obtained by polymerizing dicyclopentadiene-based monomers and structures obtained by hydrogenating the repeating structures (hereinafter, sometimes referred to as "Dicyclopentadiene-based structure".).
双环戊二烯系单体表示选自双环戊二烯和双环戊二烯衍生物中的单体。双环戊二烯衍生物是指具有在双环戊二烯的环上结合了取代基的结构的化合物。取代基的个数可以为一个、也可以为两个以上。此外，两个以上的取代基的种类可以相同、也可以不同。双环戊二烯系单体可以单独使用一种、也可以将两种以上组合使用。The dicyclopentadiene-based monomer means a monomer selected from dicyclopentadiene and dicyclopentadiene derivatives. The dicyclopentadiene derivative refers to a compound having a structure in which a substituent is bonded to the ring of dicyclopentadiene. The number of substituents may be one, or two or more. In addition, the types of two or more substituents may be the same or different. The dicyclopentadiene-based monomer may be used alone or in combination of two or more.
相对于100重量％的作为降冰片烯系聚合物的原料的单体的总量，其所包含的双环戊二烯系单体的比例(聚合比)优选为50重量％以上，更优选为55重量％以上，特别优选为60重量％以上，优选为80重量％以下，更优选为75重量％以下，特别优选为70重量％以下。在双环戊二烯系单体的聚合比在上述范围的情况下，能够增大降冰片烯系聚合物的玻璃化转变温度和双折射显现性，因此能够容易地将热塑性降冰片烯系树脂的玻璃化转变温度Tg和评价双折射ΔnR控制在式(1)和式(2)的范围。The proportion (polymerization ratio) of the dicyclopentadiene-based monomer contained therein is preferably 50% by weight or more, more preferably 55% by weight, relative to 100% by weight of the total amount of monomers used as a raw material for the norbornene-based polymer. % by weight or more, particularly preferably 60% by weight or more, preferably 80% by weight or less, more preferably 75% by weight or less, particularly preferably 70% by weight or less. When the polymerization ratio of the dicyclopentadiene-based monomer is in the above-mentioned range, the glass transition temperature and birefringence development of the norbornene-based polymer can be increased, so that the thermoplastic norbornene-based resin can be easily synthesized. The glass transition temperature Tg and the evaluation birefringence ΔnR are controlled within the ranges of formula (1) and formula (2).
通常双环戊二烯系结构在降冰片烯系聚合物中的比例与双环戊二烯系单体相对于单体的总量的聚合比一致。因此，双环戊二烯系结构相对于100重量％的降冰片烯系聚合物的比例优选处于与上述双环戊二烯系单体的聚合比相同的范围。Usually, the ratio of the dicyclopentadiene-based structure in the norbornene-based polymer corresponds to the polymerization ratio of the dicyclopentadiene-based monomer to the total amount of monomers. Therefore, the ratio of the dicyclopentadiene-based structure to 100% by weight of the norbornene-based polymer is preferably in the same range as the polymerization ratio of the above-mentioned dicyclopentadiene-based monomer.
特别是在组合使用四环十二碳烯系单体和双环戊二烯系单体来作为降冰片烯系单体的情况下，它们的量的比优选在规定的范围。具体而言，相对于100重量份的四环十二碳烯系单体，双环戊二烯系单体的量优选为100重量份以上，更优选为150重量份以上，特别优选为200重量份以上，优选为500重量份以下，更优选为450重量份以下，特别优选为400重量份以下。因此，在降冰片烯系聚合物中，相对于100重量份的四环十二碳烯系结构，双环戊二烯系结构的量优选为100重量份以上，更优选为150重量份以上，特别优选为200重量份以上，优选为500重量份以下，更优选为450重量份以下，特别优选为400重量份以下。在上述的量比在上述范围的情况下，能够增大降冰片烯系聚合物的玻璃化转变温度和双折射显现性，因此能够容易地将热塑性降冰片烯系树脂的玻璃化转变温度Tg和评价双折射ΔnR控制在式(1)和式(2)的范围。In particular, when a tetracyclododecene-based monomer and a dicyclopentadiene-based monomer are used in combination as a norbornene-based monomer, the quantitative ratio thereof is preferably within a predetermined range. Specifically, the amount of the dicyclopentadiene-based monomer is preferably 100 parts by weight or more, more preferably 150 parts by weight or more, and particularly preferably 200 parts by weight with respect to 100 parts by weight of the tetracyclododecene-based monomer. Above, preferably 500 parts by weight or less, more preferably 450 parts by weight or less, particularly preferably 400 parts by weight or less. Therefore, in the norbornene-based polymer, the amount of the dicyclopentadiene-based structure is preferably 100 parts by weight or more, more preferably 150 parts by weight or more, and particularly 100 parts by weight of the tetracyclododecene-based structure. It is preferably 200 parts by weight or more, preferably 500 parts by weight or less, more preferably 450 parts by weight or less, particularly preferably 400 parts by weight or less. When the above-mentioned quantitative ratio is in the above-mentioned range, the glass transition temperature and birefringence development of the norbornene-based polymer can be increased, so the glass transition temperature Tg and the glass transition temperature of the thermoplastic norbornene-based resin can be easily adjusted Evaluation birefringence ΔnR is controlled within the range of formula (1) and formula (2).
在使用与降冰片烯系单体共聚的任意单体的情况下，该任意单体的种类在可得到具有期望的玻璃化转变温度Tg和评价双折射ΔnR的热塑性降冰片烯系树脂的范围内没有限制。作为能够与降冰片烯系单体开环共聚的任意单体，可举出例如：环己烯、环庚烯、环辛烯等单环状烯烃类及其衍生物；环己二烯、环庚二烯等环状共轭二烯及其衍生物等。此外，作为能够与降冰片烯系单体加成共聚的任意单体，可举出例如：乙烯、丙烯、1-丁烯等碳原子数为2～20的α-烯烃以及它们的衍生物；环丁烯、环戊烯、环己烯等环烯烃以及它们的衍生物；1,4-己二烯、4-甲基-1,4-己二烯、5-甲基-1,4-己二烯等非共轭二烯等。任意单体可以单独使用一种、也可以将两种以上组合使用。In the case of using an arbitrary monomer copolymerized with a norbornene-based monomer, the type of the arbitrary monomer is within a range where a thermoplastic norbornene-based resin having a desired glass transition temperature Tg and an estimated birefringence ΔnR can be obtained There is no limit within. Examples of arbitrary monomers capable of ring-opening copolymerization with norbornene-based monomers include monocyclic olefins such as cyclohexene, cycloheptene, and cyclooctene, and derivatives thereof; Cyclic conjugated dienes such as heptadiene and their derivatives, etc. In addition, examples of optional monomers capable of addition-copolymerization with norbornene-based monomers include α-olefins having 2 to 20 carbon atoms such as ethylene, propylene, and 1-butene, and derivatives thereof; Cycloalkenes such as cyclobutene, cyclopentene, cyclohexene and their derivatives; 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4- Non-conjugated dienes such as hexadiene, etc. Arbitrary monomers may be used alone or in combination of two or more.
作为降冰片烯系聚合物，优选包含使降冰片烯系单体聚合、进一步进行氢化而得到的结构的氢化物。该氢化物可以为将聚合物中的非芳香族性的不饱和键氢化了的氢化物，也可以为将聚合物中的芳香族性的不饱和键氢化了的氢化物，还可以为将聚合物中的非芳香族性的不饱和键和芳香族性的不饱和键这两者氢化了的氢化物。尤其优选将聚合物中的非芳香族性的不饱和键和芳香族性的不饱和键这两者氢化了的降冰片烯系聚合物。通过像这样使用氢化了的降冰片烯系聚合物，能够有效提高厚度方向的延迟Rth的显现性、能够减小光弹性系数。因此，能够兼具大的厚度方向的延迟Rth和低的光弹性系数。进而，通常能够有效地改善光学膜的机械强度、耐湿性、耐热性等特性。The norbornene-based polymer preferably includes a hydrogenated product having a structure obtained by polymerizing a norbornene-based monomer and further hydrogenating it. The hydrogenated product may be a hydrogenated product obtained by hydrogenating the non-aromatic unsaturated bond in the polymer, or may be a hydrogenated product obtained by hydrogenating the aromatic unsaturated bond in the polymer, or may be a hydrogenated product obtained by hydrogenating the unsaturated bond in the polymer. A hydride in which both non-aromatic unsaturated bonds and aromatic unsaturated bonds in the compound are hydrogenated. In particular, a norbornene-based polymer obtained by hydrogenating both non-aromatic unsaturated bonds and aromatic unsaturated bonds in the polymer is preferred. By using the hydrogenated norbornene-based polymer in this way, the development of retardation Rth in the thickness direction can be effectively improved, and the photoelastic coefficient can be reduced. Therefore, both a large retardation Rth in the thickness direction and a low photoelastic coefficient can be achieved. Furthermore, it is generally effective to improve properties such as mechanical strength, moisture resistance, and heat resistance of the optical film.
降冰片烯系聚合物的玻璃化转变温度优选为110℃以上，更优选为112℃以上，特别优选为114℃以上。通过像这样使用具有高玻璃化转变温度的降冰片烯系聚合物，能够抑制高温环境下的降冰片烯系聚合物的取向弛豫。因此，能够抑制高温环境下的光学膜厚度方向的延迟Rth的变化。此外，通常包含以具有上述范围的玻璃化转变温度的方式调节了降冰片烯系单体的种类和聚合比的降冰片烯系聚合物的膜，存在通过拉伸而引起的双折射的显现性大的倾向，因此容易增大光学膜的厚度方向的延迟Rth。降冰片烯系聚合物的玻璃化转变温度的上限没有特别限制，优选为180℃以下，更优选为170℃以下，特别优选为160℃以下。在降冰片烯系聚合物的玻璃化转变温度为上述上限值以下的情况下，容易增大光学膜的厚度方向的延迟Rth。The glass transition temperature of the norbornene-based polymer is preferably 110°C or higher, more preferably 112°C or higher, particularly preferably 114°C or higher. By using a norbornene-based polymer having a high glass transition temperature in this way, the orientation relaxation of the norbornene-based polymer in a high-temperature environment can be suppressed. Therefore, it is possible to suppress a change in the retardation Rth in the thickness direction of the optical film in a high-temperature environment. In addition, in general, a film containing a norbornene-based polymer whose type and polymerization ratio of norbornene-based monomers are adjusted so as to have a glass transition temperature in the above-mentioned range exhibits birefringence caused by stretching. Since it tends to be large, it is easy to increase the retardation Rth in the thickness direction of the optical film. The upper limit of the glass transition temperature of the norbornene-based polymer is not particularly limited, but is preferably 180°C or lower, more preferably 170°C or lower, particularly preferably 160°C or lower. When the glass transition temperature of a norbornene-type polymer is below the said upper limit, retardation Rth of the thickness direction of an optical film will become large easily.
降冰片烯系聚合物的玻璃化转变温度能够使用差示扫描型量热分析仪，基于JISK6911，在升温速度10℃/分钟的条件进行测定。The glass transition temperature of the norbornene-based polymer can be measured using a differential scanning calorimeter based on JIS K6911 under conditions of a temperature increase rate of 10° C./min.
降冰片烯系聚合物的玻璃化转变温度能够通过例如作为降冰片烯系聚合物的原料的降冰片烯系单体的种类和聚合比来进行调节。The glass transition temperature of the norbornene-based polymer can be adjusted by, for example, the type of norbornene-based monomer used as a raw material of the norbornene-based polymer and the polymerization ratio.
降冰片烯系聚合物优选具有大的双折射显现性。因此，降冰片烯系聚合物优选具有大的评价双折射。详细而言，降冰片烯系聚合物的评价双折射优选为0.0025以上，更优选为0.0026以上，特别优选为0.0027以上。通过像这样使用具有大的评价双折射的降冰片烯系聚合物，即使拉伸倍率低也能够显现大的延迟。因此，能够以小的拉伸倍率使光学膜显现大的厚度方向的延迟Rth，所以能够有效地改善光学膜的取向角精度。降冰片烯系聚合物的评价双折射的上限没有特别限制，优选为0.0050以下，更优选为0.0047以下，特别优选为0.0045以下。在降冰片烯系聚合物的评价双折射为上述上限值以下的情况下，能够容易地进行降冰片烯系聚合物的制造。The norbornene-based polymer preferably exhibits large birefringence. Therefore, the norbornene-based polymer preferably has a large estimated birefringence. Specifically, the evaluated birefringence of the norbornene-based polymer is preferably 0.0025 or higher, more preferably 0.0026 or higher, and particularly preferably 0.0027 or higher. By using a norbornene-based polymer having a large estimated birefringence in this way, a large retardation can be expressed even at a low draw ratio. Therefore, since the optical film can express a large retardation Rth in the thickness direction at a small draw ratio, the orientation angle accuracy of the optical film can be effectively improved. The upper limit of the evaluated birefringence of the norbornene-based polymer is not particularly limited, but is preferably 0.0050 or less, more preferably 0.0047 or less, particularly preferably 0.0045 or less. When the evaluated birefringence of the norbornene-based polymer is not more than the above upper limit, the norbornene-based polymer can be easily produced.
降冰片烯系聚合物的评价双折射能够通过下述的方法进行测定。Evaluation of Norbornene-Based Polymer Birefringence can be measured by the following method.
将降冰片烯系聚合物进行成型，得到片材。对该片材实施自由端单轴拉伸。自由端单轴拉伸是指向一个方向的拉伸，表示在该拉伸方向以外不对片材施加约束力的拉伸。上述自由端单轴拉伸的拉伸温度为比降冰片烯系聚合物的玻璃化转变温度高15℃的温度。此外，拉伸时间为1分钟，自由端单轴拉伸的拉伸倍率为1.5倍。拉伸后，在测定波长550nm测定片材中央部的面内延迟，将该面内延迟除以片材中央部的厚度，由此得到评价双折射。The norbornene-based polymer was molded to obtain a sheet. This sheet was subjected to free-end uniaxial stretching. Free-end uniaxial stretching is stretching directed in one direction, which means stretching that does not impose a constraint on the sheet in a direction other than the stretching direction. The stretching temperature of the free-end uniaxial stretching is a temperature 15° C. higher than the glass transition temperature of the norbornene-based polymer. In addition, the stretching time was 1 minute, and the stretching ratio of free-end uniaxial stretching was 1.5 times. After stretching, the in-plane retardation at the central portion of the sheet was measured at a measurement wavelength of 550 nm, and the in-plane retardation was divided by the thickness of the central portion of the sheet to obtain the evaluated birefringence.
降冰片烯系聚合物的评价双折射能够通过例如作为降冰片烯系聚合物的原料的降冰片烯系单体的种类和聚合比、以及降冰片烯系聚合物的分子量分布来进行调节。Evaluation of Norbornene-Based Polymer Birefringence can be adjusted by, for example, the type and polymerization ratio of the norbornene-based monomer used as a raw material of the norbornene-based polymer, and the molecular weight distribution of the norbornene-based polymer.
降冰片烯系聚合物的重均分子量Mw优选为10000～100000，更优选为15000～80000，特别优选为20000～60000。在重均分子量在上述范围的情况下，可高度地平衡光学膜的机械强度和成型性。The weight average molecular weight Mw of the norbornene-based polymer is preferably 10,000 to 100,000, more preferably 15,000 to 80,000, particularly preferably 20,000 to 60,000. In the case where the weight average molecular weight is in the above range, the mechanical strength and moldability of the optical film can be highly balanced.
降冰片烯系聚合物的分子量分布Mw/Mn优选为2.4以下，更优选为2.35以下，特别优选为2.3以下。在降冰片烯系聚合物的分子量分布Mw/Mn在上述范围的情况下，能够提高光学膜的粘接强度，因此能够抑制光学膜的分层(delamination)。分子量分布是指重均分子量与数均分子量的比，以“重均分子量Mw/数均分子量Mn”表示。降冰片烯系聚合物的分子量分布的下限通常为1.0以上。The molecular weight distribution Mw/Mn of the norbornene-based polymer is preferably 2.4 or less, more preferably 2.35 or less, particularly preferably 2.3 or less. When the molecular weight distribution Mw/Mn of the norbornene-based polymer is in the above-mentioned range, the adhesive strength of the optical film can be improved, and thus delamination (delamination) of the optical film can be suppressed. The molecular weight distribution refers to the ratio of the weight average molecular weight to the number average molecular weight, and is represented by "weight average molecular weight Mw/number average molecular weight Mn". The lower limit of the molecular weight distribution of the norbornene-based polymer is usually 1.0 or more.
降冰片烯系聚合物的重均分子量和数均分子量能够通过使用环己烷作为洗脱液的凝胶渗透色谱、以聚异戊二烯换算计来进行测定。在降冰片烯系聚合物不溶解于环己烷的情况下，在上述凝胶渗透色谱中也可以使用甲苯作为洗脱液。当洗脱液为甲苯时，能够以聚苯乙烯换算计来测定重均分子量和数均分子量。The weight-average molecular weight and number-average molecular weight of the norbornene-based polymer can be measured in terms of polyisoprene by gel permeation chromatography using cyclohexane as an eluent. In the case where the norbornene-based polymer is insoluble in cyclohexane, toluene can also be used as an eluent in the above-mentioned gel permeation chromatography. When the eluent is toluene, the weight average molecular weight and the number average molecular weight can be measured in terms of polystyrene.
降冰片烯系聚合物的应力双折射优选为2350×10-12Pa-1以上，更优选为2400×10-12Pa-1以上，特别优选为2550×10-12Pa-1以上，优选为3000×10-12Pa-1以下，更优选为2950×10-12Pa-1以下，特别优选为2800×10-12Pa-1以下。在降冰片烯系聚合物的应力双折射为上述范围的下限值以上的情况下，包含该降冰片烯系聚合物的膜存在通过拉伸而引起的双折射的显现性大的倾向，因此容易增大光学膜的厚度方向的延迟Rth。此外，在降冰片烯系聚合物的应力双折射为上述范围的上限值以下的情况下，易于控制光学膜的延迟Re和Rth，能够抑制延迟的面内偏差。The stress birefringence of the norbornene-based polymer is preferably 2350×10-12 Pa-1 or higher, more preferably 2400×10-12 Pa-1 or higher, particularly preferably 2550×10-12 Pa-1 or higher, preferably 3000×10-12 Pa-1 or less, more preferably 2950×10-12 Pa-1 or less, particularly preferably 2800×10-12 Pa-1 or less. When the stress birefringence of the norbornene-based polymer is greater than or equal to the lower limit of the above-mentioned range, the film containing the norbornene-based polymer tends to exhibit a large birefringence caused by stretching. It is easy to increase the retardation Rth in the thickness direction of the optical film. In addition, when the stress birefringence of the norbornene-based polymer is not more than the upper limit of the above range, it is easy to control the retardation Re and Rth of the optical film, and the in-plane variation of the retardation can be suppressed.
降冰片烯系聚合物的应力双折射能够通过下述的方法进行测定。The stress birefringence of a norbornene-based polymer can be measured by the following method.
将降冰片烯系聚合物成型为片状，得到片材。用夹子固定该片材的两端后，在一侧的夹子上固定规定重量(例如160g)的重物。接着，在设定为规定温度(例如比降冰片烯系聚合物的玻璃化转变温度高5℃的温度)的烘箱内，以未固定重物的另一侧夹子为起点，将片材吊起规定的时间(例如1小时)，进行拉伸处理。将进行了拉伸处理的片材缓慢冷却，恢复至室温。关于该片材，在测定波长650nm测定片材中心部的面内延迟，将该面内延迟除以片材中心部的厚度，由此算出δn值。然后，将该δn值除以施加于片材的应力(在上述的情况下为固定规定的重物时施加的应力)，能够求出应力双折射。The norbornene-based polymer was molded into a sheet to obtain a sheet. After fixing both ends of the sheet with clips, a weight of predetermined weight (for example, 160 g) is fixed to one clip. Next, in an oven set at a predetermined temperature (for example, a temperature 5°C higher than the glass transition temperature of the norbornene-based polymer), the sheet is lifted from the clamp on the other side where the weight is not fixed. Stretching is performed for a predetermined time (for example, 1 hour). The stretched sheet was cooled slowly and returned to room temperature. For this sheet, the in-plane retardation at the center of the sheet was measured at a measurement wavelength of 650 nm, and the δn value was calculated by dividing the in-plane retardation by the thickness of the center of the sheet. Then, the stress birefringence can be obtained by dividing this δn value by the stress applied to the sheet (in the above case, the stress applied when fixing a predetermined weight).
降冰片烯系聚合物的应力双折射能够通过作为降冰片烯系聚合物的原料的降冰片烯系单体的种类和聚合比来进行调节。The stress birefringence of the norbornene-based polymer can be adjusted by the type and polymerization ratio of the norbornene-based monomer used as the raw material of the norbornene-based polymer.
降冰片烯系聚合物能够通过包含例如下述工序的制造方法来制造：在合适的催化剂的存在下，将降冰片烯系单体和根据需要使用的任意单体进行聚合。此外，作为降冰片烯系聚合物，在制造其氢化物的情况下，降冰片烯系聚合物的制造方法也可以包含下述工序：在上述聚合之后，对于得到的聚合物，在包含镍、钯、钌等过渡金属的氢化催化剂的存在下，使其与氢接触，将碳-碳不饱和键进行氢化。The norbornene-based polymer can be produced by, for example, a production method including a step of polymerizing a norbornene-based monomer and optionally used monomers in the presence of a suitable catalyst. In addition, as a norbornene-based polymer, in the case of producing its hydrogenated product, the production method of the norbornene-based polymer may also include the step of: after the above-mentioned polymerization, the obtained polymer is mixed with nickel, In the presence of a hydrogenation catalyst of a transition metal such as palladium or ruthenium, it is brought into contact with hydrogen to hydrogenate a carbon-carbon unsaturated bond.
热塑性降冰片烯系树脂所包含的降冰片烯系聚合物的比例在可得到满足式(1)和式(2)的热塑性降冰片烯系树脂的范围内是任意的。从有效利用降冰片烯系聚合物的优异的特性的观点出发，热塑性降冰片烯系树脂所包含的降冰片烯系聚合物的比例优选为80重量％～100重量％，更优选为90重量％～100重量％，特别优选为95重量％～100重量％。The ratio of the norbornene-based polymer contained in the thermoplastic norbornene-based resin is arbitrary within the range in which the thermoplastic norbornene-based resin satisfying the formulas (1) and (2) can be obtained. From the viewpoint of effectively utilizing the excellent properties of norbornene-based polymers, the proportion of the norbornene-based polymer contained in the thermoplastic norbornene-based resin is preferably 80% by weight to 100% by weight, and more preferably 90% by weight. ~ 100% by weight, particularly preferably 95% to 100% by weight.
热塑性降冰片烯系树脂可以包含除降冰片烯系聚合物以外的任意的成分。作为任意的成分，可举出例如紫外线吸收剂、抗氧化剂、热稳定剂、光稳定剂、防静电剂、分散剂、氯捕获剂、阻燃剂、结晶成核剂、强化剂、抗粘连剂、防雾剂、离型剂、颜料、有机或无机的填充剂、中和剂、润滑剂、分解剂、金属钝化剂、防污染剂、抗菌剂等。任意的成分可以单独使用一种、也可以将两种以上以任意的比率组合使用。The thermoplastic norbornene-based resin may contain arbitrary components other than norbornene-based polymers. Examples of optional components include ultraviolet absorbers, antioxidants, heat stabilizers, light stabilizers, antistatic agents, dispersants, chlorine traps, flame retardants, crystal nucleating agents, strengthening agents, and antiblocking agents. , anti-fog agent, release agent, pigment, organic or inorganic filler, neutralizer, lubricant, decomposer, metal deactivator, anti-pollution agent, antibacterial agent, etc. Arbitrary components may be used individually by 1 type, and may be used combining 2 or more types by arbitrary ratios.
热塑性降冰片烯系树脂具有满足上述式(1)的玻璃化转变温度Tg。详细而言，热塑性降冰片烯系树脂的玻璃化转变温度Tg通常为110℃以上，优选为112℃以上，特别优选为114℃以上。通过像这样使用具有高玻璃化转变温度Tg的热塑性降冰片烯系树脂，能够抑制高温环境下的降冰片烯系聚合物的取向弛豫。因此，能够抑制高温环境下的光学膜厚度方向的延迟Rth的变化。此外，通常包含具有上述范围的玻璃化转变温度Tg的热塑性降冰片烯系树脂的膜存在通过拉伸而引起的双折射的显现性大的倾向，因此容易增大光学膜的厚度方向的延迟Rth。热塑性降冰片烯系树脂的玻璃化转变温度Tg的上限没有特别限制，优选为180℃以下，更优选为170℃以下，特别优选为160℃以下。在热塑性降冰片烯系树脂的玻璃化转变温度Tg为上述上限值以下的情况下，容易增大光学膜的厚度方向的延迟Rth。The thermoplastic norbornene-based resin has a glass transition temperature Tg satisfying the above formula (1). Specifically, the glass transition temperature Tg of the thermoplastic norbornene-based resin is usually 110°C or higher, preferably 112°C or higher, particularly preferably 114°C or higher. By using the thermoplastic norbornene-based resin having a high glass transition temperature Tg in this way, the orientation relaxation of the norbornene-based polymer in a high-temperature environment can be suppressed. Therefore, it is possible to suppress a change in the retardation Rth in the thickness direction of the optical film in a high-temperature environment. In addition, generally, a film containing a thermoplastic norbornene-based resin having a glass transition temperature Tg in the above-mentioned range tends to exhibit a large birefringence caused by stretching, so the retardation Rth in the thickness direction of the optical film tends to be increased. . The upper limit of the glass transition temperature Tg of the thermoplastic norbornene-based resin is not particularly limited, but is preferably 180°C or lower, more preferably 170°C or lower, particularly preferably 160°C or lower. When the glass transition temperature Tg of a thermoplastic norbornene-type resin is below the said upper limit, the retardation Rth of the thickness direction of an optical film will become large easily.
热塑性降冰片烯系树脂的玻璃化转变温度Tg能够使用差示扫描型量热分析仪，基于JIS K 6911，在升温速度10℃/分钟的条件进行测定。The glass transition temperature Tg of the thermoplastic norbornene-based resin can be measured using a differential scanning calorimeter in accordance with JIS K 6911 at a temperature increase rate of 10° C./min.
热塑性降冰片烯系树脂的玻璃化转变温度Tg能够通过例如作为降冰片烯系聚合物的原料的降冰片烯系单体的种类和聚合比、以及降冰片烯系聚合物的含有率来进行调节。The glass transition temperature Tg of the thermoplastic norbornene-based resin can be adjusted by, for example, the type and polymerization ratio of norbornene-based monomers used as the raw material of the norbornene-based polymer, and the content of the norbornene-based polymer. .
热塑性降冰片烯系树脂具有满足上述式(2)的评价双折射ΔnR。详细而言，热塑性降冰片烯系树脂的评价双折射ΔnR通常为0.0025以上，优选为0.0026以上，特别优选为0.0027以上。通过像这样使用具有大的评价双折射ΔnR的热塑性降冰片烯系树脂，即使拉伸倍率低也能够显现大的延迟。因此，能够以小的拉伸倍率使光学膜显现大的厚度方向的延迟Rth，所以能够有效地改善光学膜的取向角精度。热塑性降冰片烯系树脂的评价双折射ΔnR的上限没有特别限制，优选为0.0050以下，更优选为0.0047以下，特别优选为0.0045以下。在热塑性降冰片烯系树脂的评价双折射ΔnR为上述上限值以下的情况下，能够容易地进行热塑性降冰片烯系树脂的制造。The thermoplastic norbornene-based resin has an estimated birefringence ΔnR satisfying the above formula (2). Specifically, the evaluated birefringence ΔnR of the thermoplastic norbornene-based resin is usually 0.0025 or more, preferably 0.0026 or more, particularly preferably 0.0027 or more. By using a thermoplastic norbornene-based resin having a large estimated birefringence ΔnR in this way, a large retardation can be expressed even when the draw ratio is low. Therefore, since the optical film can express a large retardation Rth in the thickness direction at a small draw ratio, the orientation angle accuracy of the optical film can be effectively improved. The upper limit of the evaluated birefringence ΔnR of the thermoplastic norbornene-based resin is not particularly limited, but is preferably 0.0050 or less, more preferably 0.0047 or less, particularly preferably 0.0045 or less. When the evaluated birefringence ΔnR of the thermoplastic norbornene-based resin is not more than the above upper limit, the thermoplastic norbornene-based resin can be easily produced.
热塑性降冰片烯系树脂的评价双折射ΔnR能够通过下述的方法进行测定。Evaluation of thermoplastic norbornene-based resin The birefringence ΔnR can be measured by the following method.
将热塑性降冰片烯系树脂进行成型，得到片材。对该片材实施自由端单轴拉伸。上述自由端单轴拉伸的拉伸温度为比热塑性降冰片烯系树脂的玻璃化转变温度Tg高15℃的温度(即Tg+15℃)。此外，拉伸时间为1分钟，自由端单轴拉伸的拉伸倍率为1.5倍。拉伸后，在测定波长550nm测定片材中央部的面内延迟Re(a)，将该面内延迟Re(a)除以片材中央部的厚度T(a)，由此得到评价双折射ΔnR。The thermoplastic norbornene-based resin is molded to obtain a sheet. This sheet was subjected to free-end uniaxial stretching. The stretching temperature of the free-end uniaxial stretching is a temperature 15° C. higher than the glass transition temperature Tg of the thermoplastic norbornene-based resin (ie, Tg+15° C.). In addition, the stretching time was 1 minute, and the stretching ratio of free-end uniaxial stretching was 1.5 times. After stretching, measure the in-plane retardation Re(a) at the center of the sheet at a measurement wavelength of 550 nm, and divide the in-plane retardation Re(a) by the thickness T(a) of the center of the sheet to obtain the estimated birefringence ΔnR .
热塑性降冰片烯系树脂的评价双折射ΔnR能够通过例如作为降冰片烯系聚合物的原料的降冰片烯系单体的种类和聚合比、降冰片烯系聚合物的分子量分布、以及降冰片烯系聚合物的含有率来进行调节。Evaluation of the thermoplastic norbornene-based resin The birefringence ΔnR can be determined by, for example, the type and polymerization ratio of the norbornene-based monomer used as a raw material for the norbornene-based polymer, the molecular weight distribution of the norbornene-based polymer, and the norbornene-based polymer. Adjust the content of ethylenic polymer.
热塑性降冰片烯系树脂的应力双折射CR优选为2350×10-12Pa-1以上，更优选为2400×10-12Pa-1以上，特别优选为2550×10-12Pa-1以上，优选为3000×10-12Pa-1以下，更优选为2950×10-12Pa-1以下，特别优选为2800×10-12Pa-1以下。在热塑性降冰片烯系树脂的应力双折射CR为上述范围的下限值以上的情况下，包含该热塑性降冰片烯系树脂的膜存在通过拉伸而引起的双折射的显现性大的倾向，因此容易增大光学膜的厚度方向的延迟Rth。此外，在热塑性降冰片烯系树脂的应力双折射CR为上述范围的上限值以下的情况下，易于控制光学膜的延迟Re和Rth，能够抑制延迟的面内偏差。The stress birefringence CR of the thermoplastic norbornene-based resin is preferably 2350×10-12 Pa-1 or more, more preferably 2400×10-12 Pa-1 or more, particularly preferably 2550×10-12 Pa-1 or more, Preferably it is 3000×10-12 Pa-1 or less, more preferably 2950×10-12 Pa-1 or less, particularly preferably 2800×10-12 Pa-1 or less. When the stress birefringenceCR of the thermoplastic norbornene-based resin is equal to or greater than the lower limit of the above-mentioned range, the film containing the thermoplastic norbornene-based resin tends to show a large amount of birefringence caused by stretching. , so it is easy to increase the retardation Rth in the thickness direction of the optical film. In addition, when the stress birefringence CR of the thermoplastic norbornene-based resin is not more than the upper limit of the above range, it is easy to control the retardation Re and Rth of the optical film, and the in-plane variation of retardation can be suppressed.
热塑性降冰片烯系树脂的应力双折射CR能够通过下述的方法进行测定。The stress birefringence CR of the thermoplastic norbornene-based resin can be measured by the following method.
将热塑性降冰片烯系树脂成型为片状，得到片材。用夹子固定该片材的两端后，在一侧的夹子上固定规定重量(例如160g)的重物。接着，在设定为规定温度(例如比热塑性降冰片烯系树脂的玻璃化转变温度Tg高5℃的温度)的烘箱内，以未固定重物的一侧夹子为起点，将片材吊起规定的时间(例如1小时)，进行拉伸处理。将进行了拉伸处理的片材缓慢冷却，恢复至室温。对于该片材，在测定波长650nm测定片材中心部的面内延迟Re(b)，将该面内延迟Re(b)除以片材中心部的厚度T(b)[mm]，由此算出δn值。然后，将该δn值除以施加于片材的应力(在上述的情况下为固定规定的重物时施加的应力)，能够求出应力双折射CR。The thermoplastic norbornene-based resin is molded into a sheet to obtain a sheet. After fixing both ends of the sheet with clips, a weight of predetermined weight (for example, 160 g) is fixed to one clip. Next, in an oven set at a predetermined temperature (for example, a temperature 5°C higher than the glass transition temperature Tg of the thermoplastic norbornene-based resin), the sheet is lifted from the clamp on the side where the weight is not fixed. Stretching is performed for a predetermined time (for example, 1 hour). The stretched sheet was cooled slowly and returned to room temperature. For this sheet, the in-plane retardation Re(b) at the center of the sheet was measured at a measurement wavelength of 650 nm, and the in-plane retardation Re(b) was divided by the thickness T(b) [mm] of the center of the sheet, whereby Calculate the δn value. Then, the stress birefringence CR can be obtained by dividing this δn value by the stress applied to the sheet (in the above case, the stress applied when a predetermined weight is fixed).
热塑性降冰片烯系树脂的应力双折射CR能够通过作为降冰片烯系聚合物的原料的降冰片烯系单体的种类和聚合比、以及降冰片烯系聚合物的含有率来进行调节。The stress birefringence CR of the thermoplastic norbornene-based resin can be adjusted by the type and polymerization ratio of the norbornene-based monomer used as a raw material of the norbornene-based polymer, and the content of the norbornene-based polymer.
[3.光学膜的特性][3. Characteristics of optical film]
本实施方式的光学膜为使用上述的热塑性降冰片烯系树脂形成的膜，其厚度方向的延迟Rth和厚度d满足上述式(3)。详细而言，比Rth/d通常为3.5×10-3以上，优选为3.7×10-3以上，特别优选为4.0×10-3以上。像这样，本实施方式的光学膜能够增大单位厚度d的厚度方向的延迟Rth。因此，能够使厚度d薄化并且增大厚度方向的延迟Rth。比Rth/d的上限没有特别限制，从有效地抑制光学膜的分层的观点出发，优选为8.0×10-3以下，更优选为6.0×10-3以下。The optical film of this embodiment is a film formed using the above-mentioned thermoplastic norbornene-based resin, and its retardation Rth in the thickness direction and thickness d satisfy the above-mentioned formula (3). Specifically, the ratio Rth/d is usually 3.5×10-3 or more, preferably 3.7×10-3 or more, particularly preferably 4.0×10-3 or more. In this manner, the optical film of the present embodiment can increase the retardation Rth in the thickness direction per unit thickness d. Therefore, the thickness d can be thinned and the retardation Rth in the thickness direction can be increased. The upper limit of the ratio Rth/d is not particularly limited, but is preferably 8.0×10-3 or less, more preferably 6.0×10-3 or less from the viewpoint of effectively suppressing delamination of the optical film.
降冰片烯系聚合物的玻璃化转变温度和双折射显现性通常依赖于作为该降冰片烯系聚合物的材料的降冰片烯系单体的种类和聚合比。因此，包含该降冰片烯系聚合物的热塑性降冰片烯系树脂的玻璃化转变温度Tg和评价双折射ΔnR与作为降冰片烯系聚合物的材料的降冰片烯系单体的种类和聚合比具有相关性。因此，热塑性降冰片烯系树脂的玻璃化转变温度Tg和评价双折射ΔnR通常反映了该热塑性降冰片烯系树脂所包含的作为降冰片烯系聚合物的原料的降冰片烯系单体的种类和聚合比。根据本发明人的研究，明确了像这样包含采用了下述降冰片烯系单体的降冰片烯系聚合物的热塑性降冰片烯系树脂通过拉伸而引起的厚度方向的延迟Rth的显现性优异，该降冰片烯系单体的种类和量是以上述树脂具有规定范围的玻璃化转变温度Tg和评价双折射ΔnR的方式而选择的。因此，上述那样的具有高Rth/d的光学膜能够使用上述的包含降冰片烯系聚合物的热塑性降冰片烯系树脂作为拉伸膜而进行制造。The glass transition temperature and birefringence development of a norbornene-based polymer generally depend on the type and polymerization ratio of a norbornene-based monomer that is a material of the norbornene-based polymer. Therefore, the evaluation of the glass transition temperature Tg and birefringence ΔnR of the thermoplastic norbornene-based resin containing the norbornene-based polymer depends on the type and polymerization of the norbornene-based monomer that is the material of the norbornene-based polymer. than correlated. Therefore, the glass transition temperature Tg and the estimated birefringence ΔnR of the thermoplastic norbornene-based resin generally reflect the properties of the norbornene-based monomer that is a raw material of the norbornene-based polymer contained in the thermoplastic norbornene-based resin. species and aggregation ratios. According to the studies of the present inventors, it was clarified that the thermoplastic norbornene-based resin comprising a norbornene-based polymer using the following norbornene-based monomers exhibits the retardation Rth in the thickness direction caused by stretching Excellent, the type and amount of the norbornene-based monomer are selected so that the above-mentioned resin has a glass transition temperature Tg within a predetermined range and birefringence ΔnR is evaluated. Therefore, an optical film having a high Rth/d as described above can be produced using the above-mentioned thermoplastic norbornene-based resin containing a norbornene-based polymer as a stretched film.
本实施方式的光学膜的光弹性系数优选小。光学膜的具体的光弹性系数优选为8Brewster以下，更优选为7Brewster以下，特别优选为6Brewster以下。在此，1Brewster＝1×10-13cm2/dyn。在光学膜的光弹性系数小的情况下，该光学膜即使产生翘曲，延迟等光学特性也不易产生变化。因此，在将光学膜设置于液晶显示装置的情况下，能够抑制因光学膜的翘曲引起的漏光的发生。漏光是指在使液晶显示装置为黑显示状态的情况下、应当被遮蔽的光从屏幕漏出、屏幕变亮的现象。光弹性系数的下限没有特别限制，优选为0.5Brewster以上，更优选为1.0Brewster以上，特别优选为1.5Brewster以上。The optical film of the present embodiment preferably has a small photoelastic coefficient. The specific photoelastic coefficient of the optical film is preferably 8 Brewster or less, more preferably 7 Brewster or less, particularly preferably 6 Brewster or less. Here, 1 Brewster = 1×10-13 cm2 /dyn. When the photoelastic coefficient of the optical film is small, even if the optical film is warped, optical characteristics such as retardation are less likely to change. Therefore, when an optical film is provided in a liquid crystal display device, the generation|occurrence|production of the light leakage by the curvature of an optical film can be suppressed. Light leakage refers to a phenomenon in which, when the liquid crystal display device is in a black display state, light that should be blocked leaks from the screen and the screen becomes brighter. The lower limit of the photoelastic coefficient is not particularly limited, but is preferably 0.5 Brewster or higher, more preferably 1.0 Brewster or higher, particularly preferably 1.5 Brewster or higher.
光学膜的光弹性系数能够通过椭偏仪进行测定。The photoelastic coefficient of an optical film can be measured with an ellipsometer.
具有小的光弹性系数的光学膜能够通过例如使用包含被氢化了的降冰片烯系聚合物的热塑性降冰片烯系树脂来实现。An optical film having a small photoelastic coefficient can be realized, for example, by using a thermoplastic norbornene-based resin containing a hydrogenated norbornene-based polymer.
本实施方式的光学膜能够实现高取向角精度。具体而言，光学膜在与其厚度方向垂直的面内方向具有慢轴。而且，光学膜能够抑制该慢轴的方向的偏差。因此，能够抑制作为慢轴与某基准方向所成的角度的取向角θ的偏差，所以能够实现高取向角精度。取向角精度高的光学膜在设置于液晶显示装置的情况下，能够使屏幕的亮度、对比度等显示特性在面内均匀。The optical film of this embodiment can realize high orientation angle precision. Specifically, the optical film has a slow axis in an in-plane direction perpendicular to its thickness direction. And the optical film can suppress the deviation of the direction of this slow axis. Therefore, variation in the orientation angle θ, which is an angle formed by the slow axis and a certain reference direction, can be suppressed, so that high orientation angle accuracy can be realized. When the optical film with high orientation angle precision is provided in a liquid crystal display device, it can make display characteristics, such as the brightness of a screen and contrast, uniform in a plane.
光学膜的取向角精度能够通过取向角θ的标准偏差θσ来进行评价。光学膜的取向角θ的标准偏差θσ越小越好。具体而言，光学膜的取向角θ的标准偏差θσ优选为0°～0.15°，更优选为0°～0.14°，特别优选为0°～0.13°。The orientation angle accuracy of the optical film can be evaluated by the standard deviation θσ of the orientation angle θ. The smaller the standard deviation θσ of the orientation angle θ of the optical film, the better. Specifically, the standard deviation θσ of the orientation angle θ of the optical film is preferably 0° to 0.15°, more preferably 0° to 0.14°, and particularly preferably 0° to 0.13°.
光学膜的取向角θ的标准偏差θσ能够通过下述的方法来进行测定。The standard deviation θσ of the orientation angle θ of the optical film can be measured by the following method.
将光学膜的慢轴与某基准方向所成的角度的绝对值作为取向角θ来进行测定。在光学膜的宽度方向50mm的间隔、在长度方向10m的间隔的多个测定位置进行该测定。然后，根据这些测定结果，能够计算取向角θ的标准偏差θσ。The absolute value of the angle formed by the slow axis of the optical film and a certain reference direction was measured as an orientation angle θ. The measurement was performed at a plurality of measurement positions at intervals of 50 mm in the width direction of the optical film and at intervals of 10 m in the longitudinal direction. Then, based on these measurement results, the standard deviation θσ of the orientation angle θ can be calculated.
通常，光学膜可使用热塑性降冰片烯系树脂作为拉伸膜来进行制造。此外，由于热塑性降冰片烯系树脂的双折射显现性优异，所以用于显现满足式(3)的程度的大的延迟所需要的拉伸倍率小。因此，在作为使用热塑性降冰片烯系树脂来形成拉伸膜而制造光学膜时，能够减小拉伸倍率。通过这样小的拉伸倍率，上述的光学膜能够实现高取向角精度。Generally, an optical film can be manufactured using a thermoplastic norbornene-type resin as a stretched film. In addition, since the thermoplastic norbornene-based resin exhibits excellent birefringence, the draw ratio required to develop a large retardation satisfying the formula (3) is small. Therefore, when an optical film is produced as a stretched film using a thermoplastic norbornene-based resin, the draw ratio can be reduced. With such a small stretch ratio, the above-mentioned optical film can achieve high orientation angle accuracy.
本实施方式的光学膜的耐热性优异。具体而言，光学膜能够抑制高温环境下的厚度方向延迟Rth的变化。耐热性优异的光学膜能够应用于在高温环境下使用的液晶显示装置。The optical film of this embodiment is excellent in heat resistance. Specifically, the optical film can suppress a change in thickness direction retardation Rth in a high-temperature environment. An optical film excellent in heat resistance can be applied to a liquid crystal display device used in a high-temperature environment.
光学膜的耐热性能够通过在高温环境下的耐久试验得到的厚度方向的延迟Rth的变化率来进行评价。例如，测定了光学膜的厚度方向的延迟Rth0之后，对该光学膜进行在85℃的环境下保管500小时的耐久试验。耐久试验后，测定光学膜的厚度方向的延迟Rth1。然后，将耐久试验得到的光学膜的厚度方向的延迟的变化量Rth0-Rth1除以耐久试验前的光学膜的厚度方向的延迟Rth0，能够计算该变化率。根据本实施方式的光学膜，能够使上述的厚度方向的延迟Rth的变化率优选为3％以下。The heat resistance of an optical film can be evaluated by the change rate of the retardation Rth in the thickness direction obtained by the endurance test in a high-temperature environment. For example, after measuring the retardation Rth0 in the thickness direction of the optical film, the durability test in which the optical film was stored in an environment of 85° C. for 500 hours was performed. After the durability test, retardation Rth1 in the thickness direction of the optical film was measured. Then, the rate of change can be calculated by dividing the change amount Rth0-Rth1 of the retardation in the thickness direction of the optical film obtained in the durability test by the retardation Rth0 in the thickness direction of the optical film before the durability test. According to the optical film of the present embodiment, the rate of change in retardation Rth in the thickness direction described above can be preferably 3% or less.
光学膜包含的热塑性降冰片烯系树脂具有高的玻璃化转变温度Tg。因此，即使在高温环境下，热塑性降冰片烯系树脂中包含的降冰片烯系聚合物的分子也不易产生取向弛豫。因此，能够如上述那样抑制高温环境下的厚度方向的延迟Rth的变化。The thermoplastic norbornene-based resin contained in the optical film has a high glass transition temperature Tg. Therefore, the molecules of the norbornene-based polymer contained in the thermoplastic norbornene-based resin are less likely to undergo orientation relaxation even under a high-temperature environment. Therefore, as described above, it is possible to suppress a change in the retardation Rth in the thickness direction under a high-temperature environment.
本实施方式的光学膜优选具有高耐湿性。因此，光学膜优选能够抑制高湿度环境下的厚度方向的延迟Rth的变化。耐湿性优异的光学膜能够应用于在高湿度环境下使用的液晶显示装置。The optical film of the present embodiment preferably has high moisture resistance. Therefore, it is preferable that the optical film can suppress a change in retardation Rth in the thickness direction under a high-humidity environment. An optical film excellent in moisture resistance can be applied to a liquid crystal display device used in a high-humidity environment.
光学膜的耐湿性能够通过在高湿度环境下的耐久试验得到的厚度方向的延迟Rth的变化率来进行评价。例如，在测定了光学膜的厚度方向的延迟Rth0之后，对该光学膜进行在60℃、湿度90％的环境下保管500小时的耐久试验。耐久试验后，测定光学膜的厚度方向的延迟Rth2。然后，将耐久试验得到的光学膜的厚度方向的延迟的变化量Rth0-Rth2除以耐久试验前的光学膜的厚度方向的延迟Rth0，能够计算该变化率。根据本实施方式，能够使上述的厚度方向的延迟Rth的变化率优选为3％以下。The moisture resistance of an optical film can be evaluated by the change rate of the retardation Rth in the thickness direction obtained by the durability test in a high-humidity environment. For example, after measuring the retardation Rth0 in the thickness direction of the optical film, the optical film was subjected to a durability test in which it was stored in an environment of 60° C. and a humidity of 90% for 500 hours. After the endurance test, the retardation Rth2 in the thickness direction of the optical film was measured. Then, the rate of change can be calculated by dividing the change amount Rth0-Rth2 of the retardation in the thickness direction of the optical film obtained in the durability test by the retardation Rth0 in the thickness direction of the optical film before the durability test. According to the present embodiment, the rate of change in the retardation Rth in the thickness direction described above can preferably be 3% or less.
降冰片烯系聚合物优选耐湿性优异，因此光学膜容易抑制湿气的侵入。因此，即使在高湿度环境下，光学膜中包含的降冰片烯系聚合物的分子也不易产生取向弛豫。因此，能够如上述那样抑制高湿度环境下的厚度方向的延迟Rth的变化。Since the norbornene-based polymer is preferably excellent in moisture resistance, the optical film can easily suppress the intrusion of moisture. Therefore, even in a high-humidity environment, the molecules of the norbornene-based polymer contained in the optical film are less likely to undergo orientation relaxation. Therefore, as described above, it is possible to suppress a change in retardation Rth in the thickness direction under a high-humidity environment.
本实施方式的光学膜优选具有低吸水率。例如，在23℃的水中浸渍了24小时的情况下，光学膜的重量基准的吸水率优选为0％～0.15％，更优选为0％～0.10％，特别优选为0％～0.05％。在像这样具有低吸水率的情况下，光学膜能够具有上述那样优异的耐湿性。The optical film of the present embodiment preferably has a low water absorption. For example, when immersed in water at 23° C. for 24 hours, the water absorption of the optical film is preferably 0% to 0.15%, more preferably 0% to 0.10%, particularly preferably 0% to 0.05%. When having such a low water absorption rate, the optical film can have the above-mentioned excellent moisture resistance.
本实施方式的光学膜优选能够抑制分层。因此，在光学膜使用粘接剂对偏振片等膜进行贴合的情况下，能够不易剥离光学膜。鉴于包含降冰片烯系聚合物的现有的拉伸膜通常容易产生分层，本实施方式的光学膜能够抑制分层为该光学膜的优点之一。It is preferable that the optical film of this embodiment can suppress delamination. Therefore, when an optical film is bonded to films, such as a polarizing plate, using an adhesive agent, it can become difficult to peel an optical film. In view of the fact that conventional stretched films containing norbornene-based polymers are generally prone to delamination, the optical film according to the present embodiment can suppress delamination, which is one of the advantages of the optical film.
本实施方式的光学膜的面内延迟Re根据该光学膜的用途可以是任意的值。当示出具体的范围时，光学膜的面内延迟Re优选为40nm以上，更优选为45nm以上，特别优选为50nm以上，优选为80nm以下，更优选为75nm以下，特别优选为70nm以下。在光学膜的面内延迟Re为上述范围的下限值以上的情况下，容易使延迟的显现性良好。此外，在光学膜的面内延迟Re为上述范围的上限值以下的情况下，能够抑制延迟在面内的偏差。面内延迟Re可根据图像显示装置的设计在上述范围内适当地进行选择。The in-plane retardation Re of the optical film of the present embodiment may be any value depending on the use of the optical film. When a specific range is shown, the in-plane retardation Re of the optical film is preferably 40 nm or more, more preferably 45 nm or more, particularly preferably 50 nm or more, preferably 80 nm or less, more preferably 75 nm or less, particularly preferably 70 nm or less. When the in-plane retardation Re of an optical film is more than the lower limit value of the said range, it becomes easy to make retardation favorable. Moreover, when the in-plane retardation Re of an optical film is below the upper limit of the said range, the variation in retardation in a plane can be suppressed. The in-plane retardation Re can be appropriately selected within the above range according to the design of the image display device.
本实施方式的光学膜的厚度方向的延迟Rth根据该光学膜的用途可以是任意的值。当示出具体的范围时，光学膜的厚度方向的延迟Rth优选为100nm以上，更优选为120nm以上，特别优选为150nm以上，优选为400nm以下，更优选为380nm以下，特别优选为360nm以下。在光学膜的厚度方向的延迟Rth为上述范围的下限值以上的情况下，能够提高图像显示装置在倾斜方向的对比度。此外，在光学膜的厚度方向的延迟Rth为上述范围的上限值以下的情况下，能够抑制厚度方向的延迟Rth和取向角在面内的偏差。厚度方向的延迟Rth可根据图像显示装置的设计在上述范围内适当地进行选择。The retardation Rth in the thickness direction of the optical film of the present embodiment may be any value depending on the use of the optical film. When a specific range is shown, the retardation Rth in the thickness direction of the optical film is preferably 100 nm or more, more preferably 120 nm or more, particularly preferably 150 nm or more, preferably 400 nm or less, more preferably 380 nm or less, particularly preferably 360 nm or less. When the retardation Rth in the thickness direction of an optical film is more than the lower limit value of the said range, the contrast in the oblique direction of an image display apparatus can be improved. Moreover, when the retardation Rth of the thickness direction of an optical film is below the upper limit of the said range, the retardation Rth of a thickness direction and the in-plane variation of an orientation angle can be suppressed. The retardation Rth in the thickness direction can be appropriately selected within the above range according to the design of the image display device.
本实施方式的光学膜优选具有高全光线透过率。光学膜的具体的全光线透过率优选为85％～100％，更优选为87％～100％，特别优选为90％～100％。全光线透过率可以使用市售的分光光度计在波长为400nm以上且700nm以下的范围进行测定。The optical film of the present embodiment preferably has a high total light transmittance. The specific total light transmittance of the optical film is preferably 85% to 100%, more preferably 87% to 100%, particularly preferably 90% to 100%. The total light transmittance can be measured using a commercially available spectrophotometer at a wavelength of not less than 400 nm and not more than 700 nm.
从提高安装了层叠膜的液晶显示装置的图像清晰度的观点出发，本实施方式的光学膜优选雾度小。光学膜的雾度优选为1％以下，更优选为0.8％以下，特别优选为0.5％以下。雾度可以根据JIS K7361-1997使用浊度计来进行测定。It is preferable that the optical film of this embodiment has a small haze from a viewpoint of improving the image clarity of the liquid crystal display device to which the laminated film was mounted. The haze of the optical film is preferably 1% or less, more preferably 0.8% or less, particularly preferably 0.5% or less. Haze can be measured using a turbidimeter according to JIS K7361-1997.
本实施方式的光学膜优选薄。通过使用上述的热塑性降冰片烯系树脂，光学膜即使薄也能够得到大的厚度方向的延迟Rth。此外，在光学膜薄的情况下，能够抑制光学膜的翘曲，因此能够减小因翘曲导致的延迟等光学特性的变化。因此，在将光学膜设置于液晶显示装置的情况下，能够抑制因光学膜的翘曲引起的漏光的发生。光学膜的具体的厚度d优选为120μm以下，更优选为100μm以下，特别优选为80μm以下。厚度d的下限没有特别限制，从抑制分层的观点出发，优选为20μm以上，更优选为30μm以上，特别优选为40μm以上。The optical film of this embodiment is preferably thin. By using the above-mentioned thermoplastic norbornene-based resin, even if the optical film is thin, it is possible to obtain a large retardation Rth in the thickness direction. In addition, when the optical film is thin, warping of the optical film can be suppressed, and thus changes in optical characteristics such as retardation due to warping can be reduced. Therefore, when an optical film is provided in a liquid crystal display device, the generation|occurrence|production of the light leakage by the curvature of an optical film can be suppressed. The specific thickness d of the optical film is preferably 120 μm or less, more preferably 100 μm or less, particularly preferably 80 μm or less. The lower limit of the thickness d is not particularly limited, but from the viewpoint of suppressing delamination, it is preferably 20 μm or more, more preferably 30 μm or more, particularly preferably 40 μm or more.
[4.光学膜的制造方法][4. Manufacturing method of optical film]
上述的光学膜能够通过例如包含下述工序的制造方法来进行制造：将热塑性降冰片烯系树脂进行成型得到树脂膜的工序；拉伸该树脂膜的工序。为了将拉伸前的树脂膜与拉伸后得到的光学膜进行区别，以下有时酌情称为“拉伸前膜”。The aforementioned optical film can be produced by, for example, a production method including the steps of molding a thermoplastic norbornene-based resin to obtain a resin film, and stretching the resin film. In order to distinguish the resin film before stretching from the optical film obtained after stretching, it may be referred to as a "film before stretching" below as appropriate.
在将热塑性降冰片烯系树脂进行成型而得到拉伸前膜的工序中，成型方法没有限制。作为成型方法，可举出例如挤出成型法、溶液浇铸法、吹塑(inflation)成型法等。其中，优选挤出成型法和溶液浇铸法，特别优选挤出成型法。In the step of molding the thermoplastic norbornene-based resin to obtain a film before stretching, the molding method is not limited. As a molding method, an extrusion molding method, a solution casting method, an inflation molding method, etc. are mentioned, for example. Among them, the extrusion molding method and the solution casting method are preferable, and the extrusion molding method is particularly preferable.
准备了拉伸前膜后，进行将该拉伸前膜进行拉伸的工序。通过该拉伸可使膜中的降冰片烯系聚合物的分子取向，因此可得到具有上述光学特性的光学膜。在将拉伸前膜进行拉伸的工序中的拉伸条件能够在可得到期望的光学膜的范围任意地设定。After the pre-stretched film is prepared, a step of stretching the pre-stretched film is performed. By this stretching, the molecules of the norbornene-based polymer in the film can be oriented, so that an optical film having the above-mentioned optical properties can be obtained. The stretching conditions in the step of stretching the film before stretching can be set arbitrarily within the range in which a desired optical film can be obtained.
关于拉伸前膜的拉伸方式，例如可以为沿1个方向进行拉伸的单轴拉伸，也可以为沿非平行的2个方向进行拉伸的双轴拉伸。此外，关于双轴拉伸，可以为同时进行向2个方向的拉伸的同时双轴拉伸，也可以为进行了向一个方向的拉伸后再进行向另一个方向拉伸的逐次双轴拉伸。在这些之中，从容易制造厚度方向的延迟Rth大的光学膜的观点出发，优选双轴拉伸，更优选逐次双轴拉伸。The stretching method of the film before stretching may be, for example, uniaxial stretching in one direction or biaxial stretching in two non-parallel directions. In addition, the biaxial stretching may be simultaneous biaxial stretching that stretches in two directions at the same time, or sequential biaxial stretching that stretches in the other direction after stretching in one direction. stretch. Among these, biaxial stretching is preferable, and sequential biaxial stretching is more preferable from the viewpoint of easy production of an optical film having a large retardation Rth in the thickness direction.
拉伸前膜的拉伸方向可以任意地进行设定。例如，在拉伸前膜为长条的膜的情况下，拉伸方向可以为纵向、可以为横向，也可以为斜向。纵向表示长条的膜的长度方向，横向表示长条的膜的宽度方向，斜向表示与长条的膜的长度方向既不平行也不垂直的方向。The stretching direction of the film before stretching can be set arbitrarily. For example, when the film before stretching is a long film, the stretching direction may be longitudinal, transverse or oblique. The longitudinal direction indicates the longitudinal direction of the elongated film, the lateral direction indicates the width direction of the elongated film, and the oblique direction indicates a direction neither parallel nor perpendicular to the longitudinal direction of the elongated film.
拉伸前膜的拉伸倍率优选为1.4以上，更优选为1.5以上，优选为2.2以下，更优选为2.1以下。在拉伸倍率为上述范围的下限值以上的情况下，能够容易地得到厚度方向的延迟Rth大的光学膜。此外，在拉伸倍率为上述范围的上限值以下的情况下，能够容易地提高光学膜的取向角精度。在进行双轴拉伸的情况下，优选用向一个方向拉伸的拉伸倍率与向另一个方向拉伸的拉伸倍率的积所表示的整体的拉伸倍率处于上述范围。The stretch ratio of the film before stretching is preferably 1.4 or more, more preferably 1.5 or more, preferably 2.2 or less, more preferably 2.1 or less. When a draw ratio is more than the lower limit of the said range, the optical film with large retardation Rth in a thickness direction can be obtained easily. Moreover, when a draw ratio is below the upper limit of the said range, the orientation angle precision of an optical film can be improved easily. In the case of biaxial stretching, it is preferable that the overall stretching ratio represented by the product of the stretching ratio in one direction and the stretching ratio in the other direction is within the above-mentioned range.
拉伸前膜的拉伸温度优选为Tg℃以上，更优选为Tg+5℃以上，优选为Tg+40℃以下，更优选为Tg+30℃以下。在拉伸温度在上述范围的情况下，易使光学膜的厚度均匀。The stretching temperature of the film before stretching is preferably Tg+5°C or higher, more preferably Tg+5°C or higher, preferably Tg+40°C or lower, more preferably Tg+30°C or lower. When the stretching temperature is in the above range, it is easy to make the thickness of the optical film uniform.
如上所述，在上述的制造方法中能够通过对拉伸前膜进行拉伸来得到光学膜，但上述的制造方法也可以进一步包含任意的工序。As described above, the optical film can be obtained by stretching the film before stretching in the above-mentioned production method, but the above-mentioned production method may further include an arbitrary step.
例如，上述的制造方法也可以包含修剪光学膜的工序、对光学膜实施表面处理的工序等。For example, the above-mentioned manufacturing method may include a step of trimming the optical film, a step of surface-treating the optical film, and the like.
[5.光学层叠体][5. Optical laminated body]
本发明的一个实施方式的光学层叠体具有上述的光学膜和偏振片。光学膜即使厚度方向的延迟Rth大也能够使厚度薄，因此能够使光学层叠体薄、或者抑制光学层叠体的翘曲。此外，光学膜具有高取向角精度，因此能够使光学层叠体的光学特性在面内均匀。进而，由于光学膜具有高耐热性，所以光学层叠体也能够具有高耐热性。这样的光学层叠体能够优选地应用于液晶显示装置等图像显示装置。An optical laminate according to one embodiment of the present invention has the above-mentioned optical film and a polarizing plate. Even if the retardation Rth in the thickness direction of the optical film can be thinned, the optical layered body can be thinned or warping of the optical layered body can be suppressed. In addition, since the optical film has high orientation angle accuracy, the optical characteristics of the optical layered body can be made uniform in the plane. Furthermore, since the optical film has high heat resistance, the optical laminate can also have high heat resistance. Such an optical layered body can be preferably applied to image display devices such as liquid crystal display devices.
作为偏振片，可使用例如具有起偏器层的膜。作为起偏器层，可以使用例如对适当的乙烯醇系聚合物的膜以适当的顺序和方式实施适当的处理的起偏器层。作为该乙烯醇系聚合物的例子，可举出聚乙烯醇和部分甲缩醛化聚乙烯醇。作为膜的处理的例子，可举出使用碘和二向色性染料等二向色性物质的染色处理、拉伸处理及交联处理等。起偏器层是可以吸收具有与吸收轴平行的振动方向的线偏振光的起偏器层，特别优选偏光度优异的起偏器层。起偏器层的厚度一般为5μm～80μm，但并不限定于此。As the polarizing plate, for example, a film having a polarizer layer can be used. As the polarizer layer, for example, a film of an appropriate vinyl alcohol-based polymer that has been appropriately treated in an appropriate order and in an appropriate manner can be used. Examples of the vinyl alcohol-based polymer include polyvinyl alcohol and partially methylalized polyvinyl alcohol. Examples of the treatment of the film include dyeing treatment using a dichroic substance such as iodine and a dichroic dye, stretching treatment, and crosslinking treatment. The polarizer layer is a polarizer layer capable of absorbing linearly polarized light having a vibration direction parallel to the absorption axis, and a polarizer layer having an excellent degree of polarization is particularly preferable. The thickness of the polarizer layer is generally 5 μm to 80 μm, but is not limited thereto.
偏振片可以在起偏器层的一侧或两侧具有保护膜层用于保护起偏器层。作为保护膜层，可使用任意的透明膜层。其中，优选透明性、机械强度、热稳定性、防潮性等优异的树脂的膜层。作为这样的树脂，可举出三乙酸纤维素等乙酸树脂、聚酯树脂、聚醚砜树脂、聚碳酸酯树脂、聚酰胺树脂、聚酰亚胺树脂、聚烯烃树脂、热塑性降冰片烯系树脂、(甲基)丙烯酸树脂等。其中，从双折射小的方面出发，优选乙酸树脂、热塑性降冰片烯系树脂、(甲基)丙烯酸树脂，从透明性、低吸湿性、尺寸稳定性、轻质性等观点出发，特别优选热塑性降冰片烯系树脂。The polarizing plate may have a protective film layer on one or both sides of the polarizer layer for protecting the polarizer layer. As the protective film layer, any transparent film layer can be used. Among them, film layers of resins excellent in transparency, mechanical strength, thermal stability, moisture resistance, and the like are preferable. Examples of such resins include acetate resins such as cellulose triacetate, polyester resins, polyethersulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, and thermoplastic norbornene-based resins. , (meth)acrylic resin, etc. Among them, acetate resins, thermoplastic norbornene-based resins, and (meth)acrylic resins are preferable from the viewpoint of small birefringence, and thermoplastic resins are particularly preferable from the viewpoints of transparency, low hygroscopicity, dimensional stability, and light weight. norbornene-based resin.
上述的偏振片例如能够将起偏器层和保护膜层贴合而制造。在贴合时，可以根据需要使用粘接剂。The above-mentioned polarizing plate can be manufactured by, for example, bonding a polarizer layer and a protective film layer together. When laminating, an adhesive can be used as needed.
光学层叠体可以进一步包含任意的构件与光学膜和偏振片组合。例如，光学层叠体也可以具有用于将光学膜与偏振片贴合的粘接层。The optical laminate may further include arbitrary members in combination with an optical film and a polarizing plate. For example, an optical laminated body may have the adhesive layer for bonding an optical film and a polarizing plate together.
光学层叠体的厚度没有特别限制，优选为30μm以上，更优选为50μm以上，优选为150μm以下，更优选为130μm以下。The thickness of the optical laminate is not particularly limited, but is preferably 30 μm or more, more preferably 50 μm or more, preferably 150 μm or less, more preferably 130 μm or less.
[6.液晶显示装置][6. Liquid crystal display device]
本发明的一个实施方式的液晶显示装置具有上述的光学层叠体。如上所述，光学层叠体具有的光学膜能够很薄，因此光学层叠体不易产生翘曲。因此，能够抑制因在翘曲部分的光学膜的光学特性变化而导致的漏光的发生。上述的翘曲通常容易在液晶显示装置的屏幕的边角处产生，但在本实施方式的液晶显示装置中，能够抑制这样的在边角处的漏光。此外，光学膜能够具有高取向角精度，因此在本实施方式的液晶显示装置中，能够使屏幕的亮度、对比度等显示特性在屏幕的面内均匀。进而，由于光学膜具有高耐热性，所以本实施方式的液晶显示装置能够抑制高温环境下的显示特性的变化。A liquid crystal display device according to one embodiment of the present invention has the above-mentioned optical layered body. As mentioned above, since the optical film which an optical laminated body has can be made thin, warping does not generate|occur|produce easily in an optical laminated body. Therefore, it is possible to suppress the occurrence of light leakage due to changes in the optical characteristics of the optical film at the warped portion. The above-mentioned warpage is usually likely to occur at the corners of the screen of a liquid crystal display device, but in the liquid crystal display device of this embodiment, such light leakage at the corners can be suppressed. In addition, since the optical film can have high orientation angle accuracy, in the liquid crystal display device of this embodiment, display characteristics such as brightness and contrast of the screen can be made uniform within the screen surface. Furthermore, since the optical film has high heat resistance, the liquid crystal display device of this embodiment can suppress the change of the display characteristic in a high-temperature environment.
通常，液晶显示装置具有液晶单元，在该液晶单元的至少一侧具有光学层叠体。其中，光学层叠体优选依次并排设置液晶单元、光学膜及观看侧起偏器。在这样的结构中，光学膜能够作为视角补偿膜发挥作用。Generally, a liquid crystal display device has a liquid crystal cell, and has an optical layered body on at least one side of the liquid crystal cell. Among them, it is preferable to arrange a liquid crystal cell, an optical film, and a viewing-side polarizer side by side in this order in the optical laminated body. In such a structure, an optical film can function as a viewing angle compensation film.
液晶单元可以使用例如共面开关(IPS)模式、垂直取向(VA)模式、多畴垂直取向(MVA)模式、连续焰火状排列(CPA)模式、混合排列向列(HAN)模式、扭曲向列(TN)模式、超扭曲向列(STN)模式、光补偿双折射(OCB)模式等任意模式的液晶单元。Liquid crystal cells can use, for example, in-plane switching (IPS) mode, vertical alignment (VA) mode, multi-domain vertical alignment (MVA) mode, continuous pyrotechnic alignment (CPA) mode, mixed alignment nematic (HAN) mode, twisted nematic (TN) mode, super twisted nematic (STN) mode, optically compensated birefringence (OCB) mode and other liquid crystal cells in any mode.
实施例Example
以下示出实施例对本发明进行具体地说明。但是，本发明并不限定于以下的实施例，在不脱离本发明的请求的范围和其同等的范围的范围内，可以任意地变更实施。Hereinafter, an Example is shown and this invention is demonstrated concretely. However, the present invention is not limited to the following examples, and can be arbitrarily modified and implemented within a range not departing from the claimed scope of the present invention and a range equivalent thereto.
在以下的说明中，只要没有另外说明，表示量的“％”和“份”为重量基准。只要没有另外说明，以下的操作在常温常压大气中进行。In the following description, unless otherwise stated, "%" and "part" which show an amount are based on weight. Unless otherwise stated, the following operations were carried out in the atmosphere at normal temperature and pressure.
[I.聚合物的物性值的测定方法和计算方法][I. Measuring method and calculating method of physical property value of polymer]
(聚合物的重均分子量Mw、数均分子量Mn及分子量分布Mw/Mn的测定方法)(Measurement method of weight average molecular weight Mw, number average molecular weight Mn and molecular weight distribution Mw/Mn of polymers)
聚合物的重均分子量Mw和数均分子量Mn通过以环己烷为洗脱液的凝胶渗透色谱(GPC)进行测定，作为标准聚异戊二烯换算值而求出。The weight-average molecular weight Mw and the number-average molecular weight Mn of the polymer were measured by gel permeation chromatography (GPC) using cyclohexane as an eluent, and obtained as values in terms of standard polyisoprene.
作为标准聚异戊二烯，使用TOSOH CORPORATION制标准聚异戊二烯(Mw＝602、1390、3920、8050、13800、22700、58800、71300、109000、280000)。As the standard polyisoprene, standard polyisoprene (Mw=602, 1390, 3920, 8050, 13800, 22700, 58800, 71300, 109000, 280000) manufactured by TOSOH CORPORATION was used.
测定使用3根串联连接的TOSOH CORPORATION制的柱(TSKgelG5000HXL、TSKgelG4000HXL及TSKgelG2000HXL)，在流速1.0mL/分钟、样品注射量100μL、柱温40℃的条件进行。The measurement was performed using three TOSOH CORPORATION columns (TSKgelG5000HXL, TSKgelG4000HXL, and TSKgelG2000HXL) connected in series under the conditions of a flow rate of 1.0 mL/min, a sample injection volume of 100 μL, and a column temperature of 40°C.
分子量分布Mw/Mn使用通过上述方法测定的重均分子量Mw和数均分子量Mn的测定值来算出。The molecular weight distribution Mw/Mn is calculated using the measured values of the weight average molecular weight Mw and the number average molecular weight Mn measured by the above method.
(玻璃化转变温度Tg的测定方法)(Measuring method of glass transition temperature Tg)
玻璃化转变温度Tg使用差示扫描型量热分析仪(Nano Technology Co.Ltd.制“DSC6220SII”)，基于JIS K 6911，在升温速度10℃/分钟的条件进行测定。The glass transition temperature Tg was measured using a differential scanning calorimeter ("DSC6220SII" manufactured by Nano Technology Co. Ltd.) based on JIS K 6911 under conditions of a temperature increase rate of 10° C./min.
(评价双折射ΔnR的测定方法)(Measurement method for evaluating birefringence ΔnR )
将树脂成型为宽50mm×长100mm×厚100μm的片状，得到样品片材。使用带恒温槽的拉伸试验机(Instron Japan Company Limited制“5564型”)对该样品片材实施自由端单轴拉伸。该拉伸条件如下所述。The resin was molded into a sheet having a width of 50 mm x a length of 100 mm x a thickness of 100 μm to obtain a sample sheet. This sample sheet was subjected to free-end uniaxial tension using a tensile testing machine ("5564 type" manufactured by Instron Japan Company Limited) equipped with a constant temperature bath. The stretching conditions are as follows.
拉伸温度：Tg+15℃Stretching temperature: Tg+15℃
夹子间距离：65mmDistance between clips: 65mm
拉伸倍率：1.5倍(拉伸距离32.5mm)Stretch ratio: 1.5 times (stretch distance 32.5mm)
拉伸时间：1分钟Stretching time: 1 minute
拉伸速度：32.5mm/分钟Tensile speed: 32.5mm/min
进行拉伸处理后，将拉伸了的样品片材恢复至室温，得到测定试样。After performing the stretching treatment, the stretched sample sheet was returned to room temperature to obtain a measurement sample.
对于该测定试样，使用相位差计(Axometrics,Inc.制“AXOSCAN”)，在测定波长550nm对测定试样的中心部的面内延迟Re(a)[nm]进行测定。此外，对测定试样的上述中心部的厚度T(a)[mm]进行测定。使用这些测定值Re(a)和T(a)、通过下述式子(X1)计算树脂的评价双折射ΔnR。For this measurement sample, the in-plane retardation Re(a) [nm] of the center portion of the measurement sample was measured at a measurement wavelength of 550 nm using a retardation meter (“AXOSCAN” manufactured by Axometrics, Inc.). Moreover, the thickness T(a) [mm] of the said center part of a measurement sample was measured. The evaluation birefringence ΔnR of the resin was calculated by the following formula (X1) using these measured values Re(a) and T(a).
ΔnR＝Re(a)×(1/T(a))×10-6 (X1)ΔnR = Re(a)×(1/T(a))×10-6 (X1)
(应力双折射CR的测定方法)(Measurement method of stress birefringence CR )
将树脂成型为长35mm×宽10mm×厚1mm的片状，得到样品片材。用夹子固定该样品片材的两端后，在一侧夹子上固定160g的重物。接着，在温度设定为树脂的玻璃化转变温度Tg+5℃的烘箱内，以未固定重物的另一侧夹子作为起点，将样品片材吊起1小时，进行拉伸处理。然后，将样品片材缓慢冷却，恢复至室温，得到测定试样。The resin was molded into a sheet having a length of 35 mm x a width of 10 mm x a thickness of 1 mm to obtain a sample sheet. After fixing both ends of the sample sheet with clips, a 160-g weight was fixed to one side of the clips. Next, in an oven set at the glass transition temperature Tg of the resin + 5°C, the sample sheet was suspended for 1 hour from the other side of the clamp where no weight was fixed as a starting point, and stretching was performed. Then, the sample sheet was cooled slowly and returned to room temperature to obtain a measurement sample.
对于该测定试样，使用双折射计(Photonic Lattice,Inc.制“WPA-100”)，在测定波长650nm对测定试样的中心部的面内延迟Re(b)[nm]进行测定。此外，对测定试样的上述中心部的厚度T(b)[mm]进行测定。使用这些测定值Re(b)和T(b)，通过下述式子(X2)算出δn值。For this measurement sample, the in-plane retardation Re(b) [nm] at the center of the measurement sample was measured at a measurement wavelength of 650 nm using a birefringence meter (“WPA-100” manufactured by Photonic Lattice, Inc.). Moreover, the thickness T(b) [mm] of the said center part of a measurement sample was measured. Using these measured values Re(b) and T(b), the δn value was calculated by the following formula (X2).
δn＝Re(b)×(1/T(b))×10-6 (X2)δn=Re(b)×(1/T(b))×10-6 (X2)
使用该δn值和施加于样品的应力F，通过下述式子(X3)计算应力双折射CR。Using this δn value and the stress F applied to the sample, the stress birefringence CR is calculated by the following formula (X3).
CR＝δn/F (X3)CR ＝δn/F (X3)
[II.光学膜的特性的评价方法][II. Evaluation method of properties of optical film]
(光学膜的光弹性系数的测定方法)(Measuring method of photoelastic coefficient of optical film)
光学膜的光弹性系数能够通过椭偏仪进行测定。The photoelastic coefficient of an optical film can be measured with an ellipsometer.
(光学膜的取向角精度的评价方法)(Evaluation Method of Orientation Angle Accuracy of Optical Film)
将光学膜的慢轴与长度方向所成的角度的绝对值作为取向角θ来进行测定。该测定使用偏光显微镜(Olympus Corporation制的偏光显微镜“BX51”)进行。此外，在光学膜的宽度方向50mm的间隔、在长度方向10m的间隔的多个测定位置进行上述取向角θ的测定。计算这些测定结果的标准偏差θσ作为取向角精度的评价指标。取向角θ的标准偏差θσ越小则取向角θ的偏差越小，越优选。The absolute value of the angle formed by the slow axis of the optical film and the longitudinal direction was measured as an orientation angle θ. This measurement was performed using a polarizing microscope (polarizing microscope "BX51" manufactured by Olympus Corporation). Moreover, the measurement of the said orientation angle (theta) was performed at the interval of 50 mm in the width direction of an optical film, and the some measurement position of the interval of 10 m in the longitudinal direction. The standard deviation θσ of these measurement results was calculated as an evaluation index of the orientation angle accuracy. The smaller the standard deviation θσ of the orientation angle θ is, the smaller the deviation of the orientation angle θ is, which is more preferable.
(光学膜的分层的评价方法)(Evaluation method of delamination of optical film)
作为被粘物(adherend)，准备使用包含降冰片烯系聚合物的树脂形成的未拉伸膜(日本瑞翁株式会社制“Zeonor film”、厚度100μm、树脂的玻璃化转变温度160℃、未实施拉伸处理的膜)。在作为测定对象膜的光学膜的单面和上述未拉伸膜的单面实施电晕处理。在光学膜的实施了电晕处理的面和未拉伸膜的实施了电晕处理的面这两个面附着粘接剂(Toyochem co.,ltd.制的UV粘接剂CRB系列)。将附着了粘接剂的面彼此进行贴合。然后，使用无极UV照射装置(Heraeus Ltd.制)，对粘接剂进行紫外线照射，使粘接剂固化。关于上述的紫外线照射，使用D型灯作为灯具，在峰值照度100mW/cm2、累积光量3000mJ/cm2的条件进行。由此，得到具有未拉伸膜/粘接剂的层/光学膜的层结构的样品膜。As an adherend (adherend), an unstretched film ("Zeonor film" manufactured by Nippon Zeon Co., Ltd., thickness 100 μm, resin glass transition temperature 160° C., unstretched film) formed using a resin containing a norbornene-based polymer was prepared. Stretched film). Corona treatment was given to one side of the optical film which is the film to be measured and one side of the above-mentioned unstretched film. An adhesive (UV adhesive CRB series manufactured by Toyochem Co., Ltd.) was attached to both surfaces of the corona-treated surface of the optical film and the corona-treated surface of the unstretched film. The surfaces to which the adhesive is applied are bonded together. Then, the adhesive was irradiated with ultraviolet rays using an electrodeless UV irradiation device (manufactured by Heraeus Ltd.) to cure the adhesive. The above ultraviolet irradiation was carried out under the conditions of a peak illuminance of 100 mW/cm2 and a cumulative light intensity of 3000 mJ/cm2 using a D-type lamp as a lamp. Thus, a sample film having a layer structure of an unstretched film/adhesive layer/optical film was obtained.
对于得到的样品膜，按照下述步骤实施90度剥离试验。About the obtained sample film, the 90 degree peeling test was implemented according to the following procedure.
将样品膜裁剪为宽度15mm，得到膜片。将该膜片的光学膜侧的面使用粘结剂贴合至载玻片的表面。此时，作为粘结剂，使用双面粘结胶带(Nitto Denko Corporation制，产品编号“CS9621”)。将膜片中包含的未拉伸膜夹在高性能型数显式推拉力计(IMADA Co.,Ltd.制“ZP-5N”)的顶端，沿载玻片表面的法线方向，以300mm/分钟的速度牵引该未拉伸膜，测定牵引力的大小，将其作为剥离强度。剥离强度的评价按照以下的评价基准进行。The sample film was cut to a width of 15 mm to obtain a film piece. The surface on the optical film side of the film sheet was bonded to the surface of a slide glass using an adhesive. At this time, as an adhesive, a double-sided adhesive tape (manufactured by Nitto Denko Corporation, product number "CS9621") was used. The unstretched film contained in the diaphragm is clamped on the top of a high-performance digital display push-pull gauge ("ZP-5N" manufactured by IMADA Co., Ltd.), along the normal direction of the surface of the slide glass, at a distance of 300mm This unstretched film was pulled at a speed of 1/min, the magnitude of the pulling force was measured, and this was defined as the peel strength. The evaluation of the peel strength was performed according to the following evaluation criteria.
良：1.0N/15mm以上。Good: 1.0N/15mm or more.
不良：小于1.0N/15mm。Bad: less than 1.0N/15mm.
(光学膜的延迟Rth、Re及厚度d的测定方法、以及Rth/d的评价方法)(Measurement method of retardation Rth, Re and thickness d of optical film, and evaluation method of Rth/d)
光学膜的厚度方向的延迟Rth和面内延迟Re使用相位差计(Axometrics,Inc.制“AXOSCAN”)在测定波长550nm进行测定。Retardation Rth in the thickness direction of the optical film and in-plane retardation Re were measured at a measurement wavelength of 550 nm using a retardation meter ("AXOSCAN" manufactured by Axometrics, Inc.).
光学膜的厚度d通过卡规(Mitutoyo Corporation制“ID-C112BS”)进行测定。The thickness d of the optical film was measured with a caliper (“ID-C112BS” manufactured by Mitutoyo Corporation).
将测定的厚度方向的延迟Rth除以厚度d，算出Rth/d。Rth/d was calculated by dividing the measured retardation Rth in the thickness direction by the thickness d.
(85℃、经过500小时后的光学膜的厚度方向的延迟Rth的变化率的评价方法)(Evaluation method of change rate of retardation Rth in the thickness direction of an optical film after 500 hours at 85°C)
在下述的耐久试验之前，测定光学膜的厚度方向的延迟Rth0。然后，对光学膜进行在85℃的环境下保管500小时的耐久试验。耐久试验后，测定光学膜的厚度方向的延迟Rth1。根据这些测定值Rth0和Rth1，按照下述式(X4)计算基于耐久试验的光学膜的厚度方向的延迟的变化率(Rth变化率)。Before the durability test described below, the retardation Rth0 in the thickness direction of the optical film was measured. Then, the durability test which stored the optical film in the environment of 85 degreeC for 500 hours was done. After the durability test, retardation Rth1 in the thickness direction of the optical film was measured. Based on these measured values Rth0 and Rth1, the change rate (Rth change rate) of the retardation in the thickness direction of the optical film based on the endurance test was calculated according to the following formula (X4).
Rth变化率(％)＝{(Rth0-Rth1)/Rth0}×100 (X4)Rth change rate (%)={(Rth0-Rth1)/Rth0}×100 (X4)
上述的Rth变化率越小，则表示光学膜的耐热性越优异。因此按照下述的评价基准评价求出的Rth变化率。The smaller the above-mentioned Rth rate of change, the more excellent the heat resistance of the optical film. Therefore, the obtained Rth change rate was evaluated according to the following evaluation criteria.
良：Rth变化率为3％以下。Good: The rate of change in Rth is 3% or less.
不良：Rth变化率大于3％。Bad: The rate of change of Rth is more than 3%.
(60℃、湿度90％、经过500小时后的光学膜的厚度方向的延迟Rth的变化率的评价方法)(Evaluation method of the rate of change in retardation Rth in the thickness direction of the optical film after 60°C, humidity 90%, and 500 hours)
在下述的耐久试验之前，测定光学膜的厚度方向的延迟Rth0。然后，对光学膜进行在60℃、湿度90％的环境下保管500小时的耐久试验。耐久试验后，测定光学膜的厚度方向的延迟Rth2。根据这些测定值Rth0和Rth2，按照下述式(X5)计算基于耐久试验的光学膜的厚度方向的延迟的变化率(Rth变化率)。Before the durability test described below, the retardation Rth0 in the thickness direction of the optical film was measured. Then, the durability test which stored the optical film in the environment of 60 degreeC and 90% of humidity for 500 hours was done. After the endurance test, the retardation Rth2 in the thickness direction of the optical film was measured. From these measured values Rth0 and Rth2, the change rate (Rth change rate) of the retardation in the thickness direction of the optical film based on the durability test was calculated according to the following formula (X5).
Rth変化率(％)＝{(Rth0-Rth2)/Rth0}×100 (X5)Rth change rate (%)={(Rth0-Rth2)/Rth0}×100 (X5)
上述的Rth变化率越小，则表示光学膜的耐热性和耐湿性越优异。因此按照下述的评价基准评价求出的Rth变化率。The smaller the above-mentioned Rth rate of change, the more excellent the heat resistance and moisture resistance of the optical film. Therefore, the obtained Rth change rate was evaluated according to the following evaluation criteria.
良：Rth变化率为3％以下。Good: The rate of change in Rth is 3% or less.
不良：Rth变化率大于3％。Bad: The rate of change of Rth is more than 3%.
(光学膜的吸水率的测定方法)(Measurement method of water absorption rate of optical film)
将光学膜的一部分切断，准备试验片(尺寸：100mm×100mm)，测定该试验片的重量w0。然后，将该试验片在23℃的水中浸渍24小时。浸渍后，测定试验片的重量w1。然后，计算因浸渍增加的试验片的重量w1-w0相对于浸渍前的试验片的重量w0的比例(w1-w0)/w0，将其作为吸水率(％)。优选吸水率小。A part of the optical film was cut to prepare a test piece (size: 100 mm×100 mm), and the weight w0 of the test piece was measured. Then, this test piece was immersed in 23 degreeC water for 24 hours. After immersion, the weight w1 of the test piece was measured. Then, the ratio (w1-w0)/w0 of the weight w1-w0 of the test piece increased by immersion to the weight w0 of the test piece before immersion was calculated, and this was defined as the water absorption (%). It is preferable that the water absorption rate is small.
[III.液晶显示装置的特性的评价方法][III. Evaluation method of characteristics of liquid crystal display device]
(边角不均匀(Corner Mura)的评价)(Evaluation of Corner Mura)
对液晶显示装置进行在85℃的环境下保管100小时的耐久试验。然后，使液晶显示装置的屏幕为黑显示状态，目视确认屏幕的周围有无漏光(边角不均匀)。A durability test in which the liquid crystal display device was stored in an environment of 85° C. for 100 hours was performed. Then, the screen of the liquid crystal display device was turned into a black display state, and the presence or absence of light leakage (edge unevenness) around the screen was visually confirmed.
良：完全没有发现屏幕周围的漏光。Good: No light leakage around the screen was found at all.
不良：屏幕周围的漏光显著。Bad: Significant light leakage around the screen.
[实施例1][Example 1]
(1-1)开环聚合物的制造：(1-1) Manufacture of ring-opened polymers:
在内部进行了氮置换的玻璃制反应容器中，室温下在反应器中加入相对于100重量份的下述的单体的合计为200份的脱水环己烷、0.75mol％的1-己烯、0.15mol％的二异丙醚及0.44mol％的三异丁基铝，进行混合。然后，一边保持在45℃，一边历经2小时在反应器中连续地同时添加作为单体的、29重量份的四环十二碳烯(TCD)、68重量份的双环戊二烯(DCPD)及3重量份的降冰片烯(NB)、以及0.02mol％的六氯化钨(0.65重量％甲苯溶液)，进行聚合。接下来，在聚合溶液中加入0.2mol％的异丙醇，使聚合催化剂失活，终止聚合反应。在上述的说明中，单位“mol％”所表示的量均为将单体的合计量设为100mol％的值。得到的降冰片烯系开环聚合物的重均分子量Mw为2.8×104，分子量分布(Mw/Mn)为2.1。此外，单体向聚合物的转化率为100％。Into a glass reaction vessel whose interior was replaced with nitrogen, a total of 200 parts of dehydrated cyclohexane and 0.75 mol% of 1-hexene were added to the reactor at room temperature with respect to 100 parts by weight of the following monomers , 0.15 mol% of diisopropyl ether, and 0.44 mol% of triisobutylaluminum were mixed. Then, 29 parts by weight of tetracyclododecene (TCD) and 68 parts by weight of dicyclopentadiene (DCPD) were continuously and simultaneously added to the reactor over 2 hours while keeping the temperature at 45°C. and 3 parts by weight of norbornene (NB), and 0.02 mol% of tungsten hexachloride (0.65% by weight of toluene solution), and polymerized. Next, 0.2 mol% isopropanol was added to the polymerization solution to deactivate the polymerization catalyst and terminate the polymerization reaction. In the above description, all the quantities represented by the unit "mol%" are values based on the total amount of monomers being 100 mol%. The obtained norbornene-based ring-opening polymer had a weight average molecular weight Mw of 2.8×104 and a molecular weight distribution (Mw/Mn) of 2.1. Furthermore, the conversion of monomer to polymer was 100%.
(1-2)氢化的降冰片烯系聚合物的制造：(1-2) Production of hydrogenated norbornene-based polymers:
接着，将300份的上述工序(1-1)所得到的包含开环聚合物的反应溶液转移至带搅拌器的高压釜中，添加3份的硅藻土担载镍催化剂(日挥化学株式会社制“T8400RL”、镍担载率57％)，在氢压4.5MPa、160℃进行4小时氢化反应。Next, 300 parts of the reaction solution containing the ring-opened polymer obtained in the above step (1-1) was transferred to an autoclave with a stirrer, and 3 parts of diatomaceous earth-supported nickel catalyst (Nichiwa Chemical Co., Ltd. "T8400RL" manufactured by the company, nickel loading rate 57%), hydrogenation reaction was performed at 4.5 MPa of hydrogen pressure and 160 degreeC for 4 hours.
氢化反应结束后，以RADIOLITE#500作为过滤床，以压力0.25MPa对得到的溶液进行加压过滤(石川岛播磨重工业株式会社制“Fundaback Filter”)，除去氢化催化剂，得到无色透明的溶液。将得到的溶液注入大量的异丙醇中，使作为开环聚合物的氢化物的降冰片烯系聚合物沉淀。过滤沉淀了的降冰片烯系聚合物后，相对于100份的降冰片烯系聚合物，添加2.0份的溶解了0.1份的抗氧化剂[季戊四醇-四[3-(3,5-二叔丁基-4-羟基苯基)丙酸酯](Ciba·Specialty·Chemicals Corporation制、产品名“Irganox(注册商标)1010”)]的二甲苯溶液。接着，使用真空干燥机(220℃、1Torr)使其干燥6小时，得到热塑性降冰片烯系树脂。降冰片烯系聚合物的重均分子量为4.0×104，分子量分布Mw/Mn为2.3。After the hydrogenation reaction was completed, the obtained solution was pressure-filtered at a pressure of 0.25 MPa using RADIOLITE #500 as a filter bed ("Fundaback Filter" manufactured by Ishikawajima Harima Heavy Industries Co., Ltd.) to remove the hydrogenation catalyst and obtain a colorless and transparent solution. The obtained solution was poured into a large amount of isopropanol to precipitate a norbornene-based polymer which is a hydrogenated product of a ring-opened polymer. After filtering the precipitated norbornene-based polymer, 2.0 parts of an antioxidant [pentaerythritol-tetrakis[3-(3,5-di-tert-butyl 4-hydroxyphenyl) propionate] (manufactured by Ciba Specialty Chemicals Corporation, product name "Irganox (registered trademark) 1010")] in xylene solution. Next, it was dried for 6 hours using a vacuum dryer (220° C., 1 Torr) to obtain a thermoplastic norbornene-based resin. The norbornene-based polymer had a weight average molecular weight of 4.0×104 and a molecular weight distribution Mw/Mn of 2.3.
使用上述的方法测定得到的热塑性降冰片烯系树脂的玻璃化转变温度Tg、评价双折射ΔnR及应力双折射CR。热塑性降冰片烯系树脂的玻璃化转变温度Tg为110℃，评价双折射ΔnR为0.0030，应力双折射CR为2600×10-12Pa-1。The glass transition temperature Tg of the obtained thermoplastic norbornene-based resin was measured, and the birefringence ΔnR and stress birefringence CR were evaluated by the method described above. The glass transition temperature Tg of the thermoplastic norbornene-based resin was 110°C, the estimated birefringence ΔnR was 0.0030, and the stress birefringence CR was 2600×10-12 Pa-1 .
(1-3)拉伸前膜的制造：(1-3) Manufacture of film before stretching:
在双螺杆挤出机中加入上述工序(1-2)所得到的热塑性降冰片烯系树脂，通过热熔融挤出成型，成型为股状的成型体。将该成型体使用造粒切割机(strand cutter)切碎，得到热塑性降冰片烯系树脂的颗粒。The thermoplastic norbornene-based resin obtained in the above step (1-2) was added to a twin-screw extruder, and hot-melt extrusion was performed to form a strand-shaped molded body. This molded body was chopped using a pellet cutter (strand cutter) to obtain pellets of a thermoplastic norbornene-based resin.
将该颗粒在100℃干燥5小时。然后，通过常规方法将该颗粒供给至挤出机，在250℃使其熔融。然后，将熔融的热塑性降冰片烯系树脂从模头吐出至冷却鼓上，得到厚110μm的长条的拉伸前膜。The particles were dried at 100°C for 5 hours. Then, the pellets were supplied to an extruder by a conventional method and melted at 250°C. Then, the molten thermoplastic norbornene-based resin was discharged from the die onto a cooling drum to obtain a long film before stretching with a thickness of 110 μm.
(1-4)光学膜的制造：(1-4) Manufacture of optical film:
准备在辊间采用了浮动方式的纵拉伸机。使用该纵拉伸机，将上述的拉伸前膜沿纵向拉伸1.26倍，得到中间膜。使用了纵拉伸机的上述拉伸的拉伸温度为120℃，这是比热塑性降冰片烯系树脂的玻璃化转变温度Tg高10℃的温度(Tg+10℃)。A longitudinal stretching machine using a floating system between rolls is prepared. Using this longitudinal stretching machine, the aforementioned film before stretching was stretched 1.26 times in the longitudinal direction to obtain an intermediate film. The stretching temperature of the stretching using the longitudinal stretching machine was 120°C, which was 10°C higher than the glass transition temperature Tg of the thermoplastic norbornene-based resin (Tg+10°C).
然后，将上述中间膜供给至使用了扩幅法的横拉伸机，一边调节卷取张力和扩幅链张力一边沿横向拉伸至1.43倍，得到作为双轴拉伸膜的长条的光学膜。使用了横拉伸机的上述拉伸的拉伸温度为120℃，这是比热塑性降冰片烯系树脂的玻璃化转变温度Tg高10℃的温度(Tg+10℃)。得到的光学膜的面内延迟Re为60nm，厚度方向的延迟Rth为320nm，厚度d为65μm。Then, the above-mentioned intermediate film was supplied to a transverse stretching machine using an expander method, and stretched to 1.43 times in the transverse direction while adjusting the take-up tension and the expander chain tension to obtain a long optical fiber as a biaxially stretched film. membrane. The stretching temperature of the stretching using a transverse stretching machine was 120°C, which was 10°C higher than the glass transition temperature Tg of the thermoplastic norbornene-based resin (Tg+10°C). The in-plane retardation Re of the obtained optical film was 60 nm, the retardation Rth in the thickness direction was 320 nm, and the thickness d was 65 μm.
对于得到的光学膜，按照上述的方法进行了评价。The obtained optical film was evaluated according to the above-mentioned method.
(1-5)光学层叠体的制造：(1-5) Manufacture of optical laminated body:
作为长条的原料膜，准备了厚度为65μm的未拉伸聚乙烯醇膜(维尼纶膜、平均聚合物度约2400、皂化度99.9mol％)。通过导辊一边将该原料膜沿长度方向连续地运送，一边对该膜进行在30℃在纯水中浸渍1分钟的溶胀处理以及在32℃在染色溶液(以摩尔比1∶23包含碘和碘化钾的染色剂溶液、染色剂浓度1.2mmol/L)中浸渍2分钟的染色处理，使膜吸附碘。然后，将膜用硼酸3％水溶液在35℃清洗30秒。然后，在57℃，在包含硼酸3％和碘化钾5％的水溶液中，将膜拉伸至6.0倍。然后，在35℃、在包含碘化钾5％和硼酸1.0％的水溶液中对膜进行补色处理。然后，将膜在60℃干燥2分钟，得到厚度为23μm的长条的起偏器层。使用紫外可见分光光度计(JASCO Corporation制“V-7100”)测定该起偏器层的偏光度，结果为99.996％。As a long raw material film, an unstretched polyvinyl alcohol film (vinylon film, average polymer degree about 2400, saponification degree 99.9 mol%) with a thickness of 65 μm was prepared. While the raw material film is continuously conveyed in the longitudinal direction by guide rollers, the film is subjected to a swelling treatment of immersion in pure water at 30° C. for 1 minute and a dyeing solution (containing iodine and The staining treatment was performed by immersing in a dye solution of potassium iodide (a dye concentration of 1.2 mmol/L) for 2 minutes to allow iodine to be adsorbed to the membrane. Then, the membrane was washed with a 3% boric acid aqueous solution at 35° C. for 30 seconds. Then, the film was stretched to 6.0 times in an aqueous solution containing 3% of boric acid and 5% of potassium iodide at 57°C. Then, the film was subjected to color correction treatment at 35° C. in an aqueous solution containing potassium iodide 5% and boric acid 1.0%. Then, the film was dried at 60° C. for 2 minutes to obtain a long polarizer layer having a thickness of 23 μm. When the degree of polarization of this polarizer layer was measured using an ultraviolet-visible spectrophotometer ("V-7100" manufactured by JASCO Corporation), it was 99.996%.
将丙烯酸树脂(住友化学株式会社制“SUMIPEXHT55X”)供给至具备T模头的热熔融挤出膜成型机。从T模头挤出丙烯酸树脂，将丙烯酸树脂成型为膜状。由此，得到使用丙烯酸树脂形成的厚度为40μm的长条的保护膜层。An acrylic resin ("SUMIPEXHT55X" manufactured by Sumitomo Chemical Co., Ltd.) was supplied to a hot-melt extrusion film molding machine equipped with a T-die. Extrude the acrylic resin from a T-die, and mold the acrylic resin into a film. Thus, a long protective film layer having a thickness of 40 μm formed using an acrylic resin was obtained.
对得到的保护膜层的单面实施电晕处理。然后，在实施了电晕处理的保护膜层的面涂覆紫外线固化型粘接剂(株式会社ADEKA制“Arkls KRX-7007”)，形成粘接层。经由该粘接层，使用夹辊将起偏器层和保护膜层贴合。紧接着，使用UV照射装置对粘接层进行750mJ/cm2的紫外线照射，使粘接层固化。由此，得到具有起偏器层/粘接层(厚度2μm)/保护膜层的层结构的长条的偏振片。Corona treatment was given to one surface of the obtained protective film layer. Then, an ultraviolet curable adhesive ("Arkls KRX-7007" manufactured by ADEKA Corporation) was applied to the surface of the corona-treated protective film layer to form an adhesive layer. Through this adhesive layer, the polarizer layer and the protective film layer were bonded together using a nip roll. Next, the adhesive layer was irradiated with ultraviolet rays of 750 mJ/cm2 using a UV irradiation device to cure the adhesive layer. Thus, a long polarizing plate having a layer structure of polarizer layer/adhesive layer (thickness 2 μm)/protective film layer was obtained.
对光学膜的单面实施电晕处理。然后，在实施了电晕处理的光学膜的面，涂覆紫外线固化型粘接剂(株式会社ADEKA制“Arkls KRX-7007”)，形成粘接层。经由该粘接层，使用夹辊将偏振片和光学膜贴合。紧接着，使用UV照射装置对粘接层进行750mJ/cm2的紫外线照射，使粘接层固化。贴合以光学膜的慢轴与起偏器层的吸收轴从厚度方向看为垂直的方式进行。由此，得到了具有光学膜/粘接层/起偏器层/粘接层/保护膜层的层结构的长条的光学层叠体。Corona treatment was performed on one side of the optical film. Then, an ultraviolet curable adhesive ("Arkls KRX-7007" manufactured by ADEKA Corporation) was applied to the surface of the corona-treated optical film to form an adhesive layer. A polarizing plate and an optical film were bonded together using a nip roll via this adhesive layer. Next, the adhesive layer was irradiated with ultraviolet rays of 750 mJ/cm2 using a UV irradiation device to cure the adhesive layer. Bonding was performed so that the slow axis of the optical film and the absorption axis of the polarizer layer were perpendicular when viewed in the thickness direction. Thus, a long optical laminate having a layer structure of optical film/adhesive layer/polarizer layer/adhesive layer/protective film layer was obtained.
(1-6)VA型液晶显示装置的制造：(1-6) Manufacture of VA type liquid crystal display device:
准备了VA型的液晶显示装置(Panasonic Corporation制的40寸电视机“TH-40AX700”)。该液晶显示装置具有贴合于液晶单元的玻璃面的观看侧的偏振片。从液晶显示装置剥离该观看侧的偏振片。然后，将上述工序(1-5)中制造的长条的光学层叠体裁剪为适合于液晶显示装置的大小，将光学膜侧的面贴合于液晶单元的玻璃面，制造试验用的VA型液晶显示装置。上述贴合以液晶显示装置原本具有的观看侧的偏振片的吸收轴方向与新贴合于液晶单元的光学层叠体的起偏器层的吸收轴方向一致的方式进行。A VA-type liquid crystal display device (40-inch TV "TH-40AX700" manufactured by Panasonic Corporation) was prepared. This liquid crystal display device has a polarizing plate bonded to the viewing side of the glass surface of the liquid crystal cell. The polarizing plate on the viewing side was peeled off from the liquid crystal display device. Then, the elongated optical laminate produced in the above step (1-5) was cut into a size suitable for the liquid crystal display device, and the surface on the optical film side was bonded to the glass surface of the liquid crystal cell to manufacture a VA type laminated body for testing. Liquid crystal display device. The bonding is carried out so that the direction of the absorption axis of the polarizing plate on the viewing side originally included in the liquid crystal display device coincides with the direction of the absorption axis of the polarizer layer of the optical laminate newly bonded to the liquid crystal cell.
对于得到的液晶显示装置，用上述的方法进行评价。The obtained liquid crystal display device was evaluated by the method mentioned above.
[实施例2][Example 2]
将上述的工序(1-1)中使用的单体的组合变更为31重量份的四环十二碳烯(TCD)、68重量份的双环戊二烯(DCPD)及1重量份的降冰片烯(NB)。The combination of the monomers used in the above step (1-1) was changed to 31 parts by weight of tetracyclododecene (TCD), 68 parts by weight of dicyclopentadiene (DCPD) and 1 part by weight of norbornanol ene (NB).
在上述的工序(1-4)中，将纵向的拉伸倍率变更为1.28倍、横向的拉伸倍率变更为1.48倍。此外，在上述的工序(1-4)中，将纵向和横向的拉伸温度变更为122.5℃，这是比热塑性降冰片烯系树脂的玻璃化转变温度Tg高10℃的温度(Tg+10℃)。In the above-mentioned step (1-4), the stretch ratio in the longitudinal direction was changed to 1.28 times, and the stretch ratio in the transverse direction was changed to 1.48 times. In addition, in the above-mentioned process (1-4), the stretching temperature in the longitudinal and transverse directions was changed to 122.5°C, which is a temperature 10°C higher than the glass transition temperature Tg of the thermoplastic norbornene-based resin (Tg+10 ℃).
除了以上的事项以外，通过与实施例1同样的操作，进行热塑性降冰片烯系树脂、光学膜及液晶显示装置的制造和评价。Production and evaluation of thermoplastic norbornene-based resins, optical films, and liquid crystal display devices were performed in the same manner as in Example 1 except for the above matters.
[实施例3][Example 3]
将上述的工序(1-1)中使用的单体的组合变更为29重量份的四环十二碳烯(TCD)、68重量份的双环戊二烯(DCPD)及3重量份的亚乙基四环十二碳烯(ETD)。The combination of the monomers used in the above step (1-1) was changed to 29 parts by weight of tetracyclododecene (TCD), 68 parts by weight of dicyclopentadiene (DCPD) and 3 parts by weight of ethylene Tetracyclododecene (ETD).
在上述的工序(1-4)中，将纵向的拉伸倍率变更为1.27倍，横向的拉伸倍率变更为1.44倍。此外，在上述的工序(1-4)中，将纵向和横向的拉伸温度变更为124℃，这是比热塑性降冰片烯系树脂的玻璃化转变温度Tg高10℃的温度(Tg+10℃)。In the above-mentioned step (1-4), the stretch ratio in the longitudinal direction was changed to 1.27 times, and the stretch ratio in the transverse direction was changed to 1.44 times. In addition, in the above-mentioned process (1-4), the stretching temperature in the longitudinal and transverse directions was changed to 124°C, which is a temperature 10°C higher than the glass transition temperature Tg of the thermoplastic norbornene-based resin (Tg+10 ℃).
除了以上的事项以外，通过与实施例1同样的操作，进行热塑性降冰片烯系树脂、光学膜及液晶显示装置的制造和评价。Production and evaluation of thermoplastic norbornene-based resins, optical films, and liquid crystal display devices were performed in the same manner as in Example 1 except for the above matters.
[实施例4][Example 4]
将上述的工序(1-1)中使用的单体的组合变更为31重量份的四环十二碳烯(TCD)、68重量份的双环戊二烯(DCPD)及1重量份的亚乙基四环十二碳烯(ETD)。The combination of the monomers used in the above step (1-1) was changed to 31 parts by weight of tetracyclododecene (TCD), 68 parts by weight of dicyclopentadiene (DCPD) and 1 part by weight of ethylene Tetracyclododecene (ETD).
在上述的工序(1-4)中，将纵向的拉伸倍率变更为1.30倍、横向的拉伸倍率变更为1.50倍。此外，在上述的工序(1-4)中，将纵向和横向的拉伸温度变更为125℃，这是比热塑性降冰片烯系树脂的玻璃化转变温度Tg高10℃的温度(Tg+10℃)。In the above-mentioned step (1-4), the stretch ratio in the longitudinal direction was changed to 1.30 times, and the stretch ratio in the transverse direction was changed to 1.50 times. In addition, in the above-mentioned process (1-4), the stretching temperature in the longitudinal and transverse directions was changed to 125°C, which is a temperature 10°C higher than the glass transition temperature Tg of the thermoplastic norbornene-based resin (Tg+10 ℃).
除了以上的事项以外，通过与实施例1同样的操作，进行热塑性降冰片烯系树脂、光学膜及液晶显示装置的制造和评价。Production and evaluation of thermoplastic norbornene-based resins, optical films, and liquid crystal display devices were performed in the same manner as in Example 1 except for the above matters.
[实施例5][Example 5]
将上述的工序(1-1)中使用的单体的组合变更为30重量份的四环十二碳烯(TCD)和70重量份的双环戊二烯(DCPD)。The combination of the monomers used in the above step (1-1) was changed to 30 parts by weight of tetracyclododecene (TCD) and 70 parts by weight of dicyclopentadiene (DCPD).
在上述的工序(1-4)中，将纵向的拉伸倍率变更为1.256倍。此外，在上述的工序(1-4)中，将纵向和横向的拉伸温度变更为125.5℃，这是比热塑性降冰片烯系树脂的玻璃化转变温度Tg高10℃的温度(Tg+10℃)。In the above-mentioned step (1-4), the stretch ratio in the longitudinal direction was changed to 1.256 times. In addition, in the above-mentioned process (1-4), the stretching temperature in the longitudinal and transverse directions was changed to 125.5°C, which is a temperature 10°C higher than the glass transition temperature Tg of the thermoplastic norbornene-based resin (Tg+10 ℃).
除了以上的事项以外，通过与实施例1同样的操作，进行热塑性降冰片烯系树脂、光学膜及液晶显示装置的制造和评价。Production and evaluation of thermoplastic norbornene-based resins, optical films, and liquid crystal display devices were performed in the same manner as in Example 1 except for the above matters.
[比较例1][Comparative example 1]
将上述的工序(1-1)中使用的单体的组合变更为31重量份的四环十二碳烯(TCD)、68重量份的双环戊二烯(DCPD)及1重量份的降冰片烯(NB)。进而，将上述的工序(1-1)中的聚合温度变更为55℃。The combination of the monomers used in the above step (1-1) was changed to 31 parts by weight of tetracyclododecene (TCD), 68 parts by weight of dicyclopentadiene (DCPD) and 1 part by weight of norbornanol ene (NB). Furthermore, the polymerization temperature in the above-mentioned process (1-1) was changed to 55 degreeC.
在上述的工序(1-4)中，将纵向的拉伸倍率变更为1.25倍、横向的拉伸倍率变更为1.45倍。此外，在上述的工序(1-4)中，将纵向和横向的拉伸温度变更为122℃，这是比热塑性降冰片烯系树脂的玻璃化转变温度Tg高10℃的温度(Tg+10℃)。In the above-mentioned step (1-4), the stretch ratio in the longitudinal direction was changed to 1.25 times, and the stretch ratio in the transverse direction was changed to 1.45 times. In addition, in the above-mentioned process (1-4), the stretching temperature in the longitudinal and transverse directions was changed to 122°C, which is a temperature 10°C higher than the glass transition temperature Tg of the thermoplastic norbornene-based resin (Tg+10 ℃).
除了以上的事项以外，通过与实施例1同样的操作，进行热塑性降冰片烯系树脂、光学膜及液晶显示装置的制造和评价。Production and evaluation of thermoplastic norbornene-based resins, optical films, and liquid crystal display devices were performed in the same manner as in Example 1 except for the above matters.
[比较例2][Comparative example 2]
将上述的工序(1-1)中使用的单体的组合变更为5重量份的四环十二碳烯(TCD)、80重量份的双环戊二烯(DCPD)及15重量份的亚乙基四环十二碳烯(ETD)。The combination of the monomers used in the above step (1-1) was changed to 5 parts by weight of tetracyclododecene (TCD), 80 parts by weight of dicyclopentadiene (DCPD), and 15 parts by weight of ethylene Tetracyclododecene (ETD).
在上述的工序(1-4)中，将纵向的拉伸倍率变更为1.35倍、横向的拉伸倍率变更为1.55倍。此外，在上述的工序(1-4)中，将纵向和横向的拉伸温度变更为114℃，这是比热塑性降冰片烯系树脂的玻璃化转变温度Tg高10℃的温度(Tg+10℃)。In the above-mentioned step (1-4), the stretch ratio in the longitudinal direction was changed to 1.35 times, and the stretch ratio in the transverse direction was changed to 1.55 times. In addition, in the above-mentioned process (1-4), the stretching temperature in the longitudinal and transverse directions was changed to 114°C, which is a temperature 10°C higher than the glass transition temperature Tg of the thermoplastic norbornene-based resin (Tg+10 ℃).
除了以上的事项以外，通过与实施例1同样的操作，进行热塑性降冰片烯系树脂、光学膜及液晶显示装置的制造和评价。Production and evaluation of thermoplastic norbornene-based resins, optical films, and liquid crystal display devices were performed in the same manner as in Example 1 except for the above matters.
[比较例3][Comparative example 3]
将上述的工序(1-1)中使用的单体的组合变更为10重量份的甲桥四氢芴(MTF)、40重量份的四环十二碳烯(TCD)及50量份的双环戊二烯(DCPD)。Change the combination of monomers used in the above-mentioned step (1-1) to 10 parts by weight of methylene tetrahydrofluorene (MTF), 40 parts by weight of tetracyclododecene (TCD) and 50 parts by weight of bicyclic pentadiene (DCPD).
在上述的工序(1-4)中，将纵向的拉伸倍率变更为1.60倍、横向的拉伸倍率变更为1.80倍。此外，在上述的工序(1-4)中，将纵向和横向的拉伸温度变更为138℃，这是比热塑性降冰片烯系树脂的玻璃化转变温度Tg高10℃的温度(Tg+10℃)。In the above-mentioned step (1-4), the stretch ratio in the longitudinal direction was changed to 1.60 times, and the stretch ratio in the transverse direction was changed to 1.80 times. In addition, in the above-mentioned process (1-4), the stretching temperature in the longitudinal and transverse directions was changed to 138°C, which is a temperature 10°C higher than the glass transition temperature Tg of the thermoplastic norbornene-based resin (Tg+10 ℃).
除了以上的事项以外，通过与实施例1同样的操作，进行热塑性降冰片烯系树脂、光学膜及液晶显示装置的制造和评价。Production and evaluation of thermoplastic norbornene-based resins, optical films, and liquid crystal display devices were performed in the same manner as in Example 1 except for the above matters.
[比较例4][Comparative example 4]
将上述的工序(1-1)中使用的单体的组合变更为10重量份的甲桥四氢芴(MTF)、40重量份的四环十二碳烯(TCD)及50量份的双环戊二烯(DCPD)。Change the combination of monomers used in the above-mentioned step (1-1) to 10 parts by weight of methylene tetrahydrofluorene (MTF), 40 parts by weight of tetracyclododecene (TCD) and 50 parts by weight of bicyclic pentadiene (DCPD).
在上述的工序(1-4)中，将纵向的拉伸倍率变更为1.20倍、横向的拉伸倍率变更为1.40倍。此外，在上述的工序(1-4)中，将纵向和横向的拉伸温度变更为138℃，这是比热塑性降冰片烯系树脂的玻璃化转变温度Tg高10℃的温度(Tg+10℃)。In the above-mentioned step (1-4), the stretch ratio in the longitudinal direction was changed to 1.20 times, and the stretch ratio in the transverse direction was changed to 1.40 times. In addition, in the above-mentioned process (1-4), the stretching temperature in the longitudinal and transverse directions was changed to 138°C, which is a temperature 10°C higher than the glass transition temperature Tg of the thermoplastic norbornene-based resin (Tg+10 ℃).
除了以上的事项以外，通过与实施例1同样的操作，进行热塑性降冰片烯系树脂、光学膜及液晶显示装置的制造和评价。Production and evaluation of thermoplastic norbornene-based resins, optical films, and liquid crystal display devices were performed in the same manner as in Example 1 except for the above matters.
[比较例5][Comparative Example 5]
作为单体使用50重量份的四环十二碳烯(TCD)和50重量份的8-甲基四环十二碳烯(MTD)，除此以外，进行与实施例1的工序(1-1)相同的操作，得到开环聚合物。开环聚合物的重均分子量Mw为4.0×104，分子量分布Mw/Mn为2.0。单体向聚合物的转化率为100％。Use 50 parts by weight of tetracyclododecene (TCD) and 8-methyltetracyclododecene (MTD) of 50 parts by weight as a monomer, in addition, carry out the operation (1- 1) Same operation to obtain ring-opened polymer. The weight average molecular weight Mw of the ring-opened polymer was 4.0×104 , and the molecular weight distribution Mw/Mn was 2.0. The conversion of monomer to polymer was 100%.
将300份的包含像这样而得到的开环聚合物的聚合反应溶液转移至带搅拌器的高压釜中，添加3份的硅藻土担载镍催化剂(日挥化学株式会社制“T8400RL”、镍担载率57％)，在氢压4.5MPa、160℃进行4小时氢化反应。300 parts of the polymerization reaction solution containing the ring-opened polymer thus obtained was transferred to an autoclave with a stirrer, and 3 parts of a diatomaceous earth-supported nickel catalyst ("T8400RL" manufactured by Nikki Chemical Co., Ltd., Nickel loading rate 57%), hydrogenation reaction was performed at 4.5 MPa of hydrogen pressure and 160 degreeC for 4 hours.
氢化反应结束后，以RADIOLITE#500作为过滤床，以压力0.25MPa对得到的溶液进行加压过滤(石川岛播磨重工业株式会社制“Fundaback Filter”)，除去氢化催化剂，得到无色透明的溶液。将得到的溶液注入大量的异丙醇中，使聚合物沉淀。过滤沉淀了的聚合物后，使用真空干燥机(220℃、1Torr)干燥6小时，得到上述的开环聚合物的氢化物。该开环聚合物的氢化物的玻璃化转变温度Tg为158℃。After the hydrogenation reaction was completed, the obtained solution was pressure-filtered at a pressure of 0.25 MPa using RADIOLITE #500 as a filter bed ("Fundaback Filter" manufactured by Ishikawajima Harima Heavy Industries Co., Ltd.) to remove the hydrogenation catalyst and obtain a colorless and transparent solution. The resulting solution was poured into a large volume of isopropanol to precipitate the polymer. After filtering the precipitated polymer, it was dried using a vacuum dryer (220° C., 1 Torr) for 6 hours to obtain a hydrogenated product of the above-mentioned ring-opened polymer. The glass transition temperature Tg of the hydrogenated product of this ring-opened polymer was 158°C.
将28重量份的该开环聚合物的氢化物、10重量份的马来酸酐及3重量份的过氧化二异丙苯溶解于130重量份的叔丁基苯，在140℃反应6小时。将得到的反应产物溶液注入甲醇中，使反应产物凝固。将该凝固物使用真空干燥机(220℃、1Torr)干燥6小时，得到马来酸改性开环聚合物氢化物。以下，有时将该马来酸改性开环聚合物氢化物称为“极性COP”。极性COP的马来酸基含有率为25摩尔％。28 parts by weight of the hydrogenated ring-opened polymer, 10 parts by weight of maleic anhydride, and 3 parts by weight of dicumyl peroxide were dissolved in 130 parts by weight of t-butylbenzene, and reacted at 140° C. for 6 hours. The obtained reaction product solution was poured into methanol to solidify the reaction product. This solidified product was dried using a vacuum dryer (220° C., 1 Torr) for 6 hours to obtain a hydrogenated maleic acid-modified ring-opened polymer. Hereinafter, this hydrogenated maleic acid-modified ring-opened polymer may be referred to as "polar COP". The maleic acid group content rate of polar COP was 25 mol%.
在上述的工序(1-3)中，作为拉伸前膜的材料的树脂，使用上述的极性COP。In the above-mentioned step (1-3), the above-mentioned polar COP is used as the resin of the material of the film before stretching.
在上述的工序(1-4)中，将纵向的拉伸倍率变更为1.62倍、横向的拉伸倍率变更为1.82倍。此外，在上述的工序(1-4)中，将纵向和横向的拉伸温度变更为180℃，这是比马来酸改性开环聚合物氢化物的玻璃化转变温度Tg高10℃的温度(Tg+10℃)。In the above-mentioned step (1-4), the stretch ratio in the longitudinal direction was changed to 1.62 times, and the stretch ratio in the transverse direction was changed to 1.82 times. In addition, in the above-mentioned step (1-4), the stretching temperature in the longitudinal and transverse directions was changed to 180°C, which was 10°C higher than the glass transition temperature Tg of the hydrogenated product of the maleic acid-modified ring-opening polymer. Temperature (Tg+10°C).
除了以上的事项以外，通过与实施例1同样的操作，进行光学膜和液晶显示装置的制造及评价。Production and evaluation of an optical film and a liquid crystal display device were performed in the same manner as in Example 1 except for the above matters.
[结果][result]
上述的实施例和比较例的结果示于下述表1和表2。在下述的表1和表2中，简称的意思如下所述。The results of the above-mentioned Examples and Comparative Examples are shown in Tables 1 and 2 below. In Table 1 and Table 2 below, the meanings of the abbreviations are as follows.
单体栏的“T”：四环十二碳烯(TCD)。"T" in the monomer column: Tetracyclododecene (TCD).
单体栏的“D”：双环戊二烯(DCPD)。"D" in the monomer column: dicyclopentadiene (DCPD).
单体栏的“N”：降冰片烯(NB)。"N" in the monomer column: norbornene (NB).
单体栏的“E”：亚乙基四环十二碳烯(ETD)。"E" in the monomer column: ethylenetetracyclododecene (ETD).
单体栏的“M”：甲桥四氢芴(MTF)。"M" in the monomer column: methyl-bridged tetrahydrofluorene (MTF).
Rth变化率(85℃)：基于在85℃的环境下保管500小时的耐久试验的光学膜的厚度方向的延迟的变化率。Rth change rate (85° C.): change rate of retardation in the thickness direction of the optical film based on a durability test stored in an environment of 85° C. for 500 hours.
Rth变化率(60℃90％)：就在60℃、湿度90％的环境下保管500小时的耐久试验的光学膜的厚度方向的延迟的变化率。Rth change rate (60° C. 90%): The change rate of the retardation in the thickness direction of the optical film in an endurance test stored in an environment of 60° C. and a humidity of 90% for 500 hours.
[表1][Table 1]
[表1.实施例的结果][Table 1. Results of Examples]
[表2][Table 2]
[表2.比较例的结果][Table 2. Results of Comparative Examples]
[参考例1.关于剥离强度的测定方法的妥当性][Reference Example 1. Validity of the method for measuring peel strength]
对于是否能够认为在上述实施例和比较例中采用的剥离强度的测定方法反映了被粘物为偏振片的情况下的剥离强度的评价，进行了评价试验。An evaluation test was performed to evaluate whether the peel strength measurement method used in the above-mentioned Examples and Comparative Examples can be considered to reflect the evaluation of the peel strength when the adherend is a polarizing plate.
通过与日本特开2005-70140号公报的实施例1所记载的方法相同的方法，准备了偏振膜和粘接剂。此外，作为测定对象膜，准备了本申请的实施例1所得到的光学膜。对该光学膜的单面实施电晕处理，经由粘接剂，将该电晕处理面贴合于偏振膜的一个表面。在偏振膜的另一个表面，经由粘接剂贴合三乙酸纤维素膜。然后，在80℃干燥7分钟使粘接剂固化，得到样品膜。对于得到的样品膜，进行与上述的(光学膜的分层的评价方法)中相同的90度剥离试验。结果，得到了与本申请实施例1所得到的值相同的剥离强度的值。A polarizing film and an adhesive were prepared by the same method as described in Example 1 of JP-A-2005-70140. In addition, the optical film obtained in Example 1 of the present application was prepared as a film to be measured. Corona treatment was performed on one surface of the optical film, and the corona-treated surface was bonded to one surface of the polarizing film via an adhesive. On the other surface of the polarizing film, a cellulose triacetate film was bonded via an adhesive. Then, the adhesive was cured by drying at 80° C. for 7 minutes to obtain a sample film. For the obtained sample film, the same 90-degree peeling test as in the above (evaluation method of delamination of an optical film) was performed. As a result, the same peel strength value as that obtained in Example 1 of the present application was obtained.
根据该结果，确认了基于上述实施例和比较例所采用的剥离强度的测定方法所得到的剥离强度的测定结果反映了被粘物为偏振片的情况下的剥离强度的评价。From this result, it was confirmed that the peel strength measurement results obtained by the peel strength measurement methods employed in the above-mentioned Examples and Comparative Examples reflect the evaluation of the peel strength when the adherend is a polarizing plate.
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| TWI808262B (en) | 2023-07-11 |
| KR102822286B1 (en) | 2025-06-18 |
| CN112703435A (en) | 2021-04-23 |
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