EP2258457A1

Movatterモバイル変換

Info

Publication number: EP2258457A1
Application number: EP09161663A
Authority: EP
Inventors: Albertus Antonius Theodoor Gebbing; Martinus Louis Maria Bos; Hans Wilderbeek
Original assignee: Mitsubishi Chemical Europe GmbH
Current assignee: Mitsubishi Chemical Europe GmbH
Priority date: 2009-06-02
Filing date: 2009-06-02
Publication date: 2010-12-08

Abstract

The present invention relates to a building element comprising a moulded part that further contains plated metal areas, wherein the moulded part comprises a layer that consists of a composition comprising a polymer and a metal compound having a spinel structure. The building element according to the invention can have a wall thickness of 5 mm or less, even a wall thickness of 4 mm or less, even a wall thickness of 3 mm or less and even a wall thickness of 2 mm or less and still have the required mechanical properties and a sufficient high resolution of the metallization can still be obtained.

Description

The present invention relates to a building element comprising a moulded part that further contains plated metal areas. Such building elements are used, for example, for educational, instructional, entertaining and/or playing purposes. Uses include educational kits for electrical engineering students and toys for children. The plated metal areas may fulfill a decorative, aesthetic, reflecting, electrical conductive and/or protective purpose. The present invention in particular relates to connectible building elements which may be removable attached to each other. By connecting a first building element to a second building element, either identical or non-identical, a plated metal area of the first building element can be connected to a plated metal area of the second building element thereby forming for example plated metal pathways. The moulded part must provide the required aesthetical and mechanical characteristics to the building element, such as strength, durability, and ductility characteristics.
Such a building element is known fromUS2008/0166926. The building element described there contains conductive paths and mechanical cylinders which may be conductive. The conductive paths may be located on the top surface of the building block and/or inside the building block. This patent publication describes that in one embodiment the conductive paths are a plated metal such as copper, nickel or tin.
A disadvantage of the use of metal plating for providing plated metal areas on a building element is that it is difficult or even impossible to obtain plated metal building elements of which the moulded part has a low wall thickness.
The object of the invention is being able to obtain a building element of a moulded part that further contains plated metal areas of which the moulded part possesses a low wall thickness.
This object is achieved in that the moulded part comprises a layer consisting of a composition comprising a polymer and a metal compound having a spinel structure.
It has surprisingly been found that with such building elements the wall thickness of the moulded part can be reduced while the building element still has the required mechanical properties and the plated metal areas can still be provided onto the moulded part with a high resolution. A low wall thickness is advantageous as this results in low material use. The building element according to the invention can have a wall thickness of 5 mm or less, even a wall thickness of 4 mm or less, even a wall thickness of 3 mm or less and even a wall thickness of 2 mm or less and still have the required mechanical properties and a sufficient high resolution of the metallization can still be obtained.
Another advantage of the building elements according to the invention is that the plated metal areas can be provided onto the moulded part easily and with high selectivity (i.e. providing the metallization at the desired place with the desired resolution). In particular with a trend of miniaturization and downsizing in dimensions, a very high selectivity is advantageous. Furthermore, a high selectivity is advantageous as the metal plated areas of the building elements can be connected with each other in a robust and selective way.
Another advantage of the building elements according to the invention is that the plated metal areas can be provided onto the moulded part easily and at high selectivity at places of the building elements which are difficult to reach, such as for example curved or sharp edges, resulting in that building elements with complex geometry can be provided with plated metal areas.
In an embodiment of the invention, the metal plated areas are electrically conductive areas that are provided onto the building elements for constructing electrical circuits in particular between at least two building elements that are connectible with each other. Generally, at least part of the electrically conductive area becomes in electrical communication as soon as an electrical power source is added to at least one such building element and activated. In particular, the metal plated areas are connected such that metal plated pathways are provided.
In a preferred embodiment of the invention, the building elements are toy building elements such as for example building blocks, base plates, gears, shafts, wheels and figures. In this embodiment, a building element may be removable attached to a second building element, either identical or non-identical, by means of for example protruding cylinders located on the top of the building elements.
The present invention will be explained more fully below in connection with preferred embodiments and with reference to the drawings, in which

Figure 1A is a perspective view of a structure built with building elements according to the invention.
Figure 1B is a perspective view of the top surface of a part of the base plate as shown inFigure 1A.
Figure 1C is a perspective view of the bottom surface of a part of the base plate as shown inFigure 1A.
Figure 2 illustrates a perspective view of the top surface of a building block according to the present invention.
Figure 3 illustrates a bottom perspective view of a building block according to the present invention.
Figure 1A shows a structure built with an electrically conductive base plate (101), building blocks (102), a figure (103), a lantern (104) and lamps (105). As soon as an electrical power source is added to at least one such building element and activated, there is possible electrical communication between the different building elements.Figure 1B shows plated metal areas (107) on the top surface of the base plate (101) andFigure 1C shows plated metal areas (106) on the bottom surface of the base plate (101).
Figure 2 shows an electrically conductive building block with conductive plated metal areas (201 and 202) which may be located on, for example, the top surface (203) of the building block and/or openings (204).Figure 2 further shows mechanical stackable cylinders (205) which are coupling studs for cooperation with coupling means on another building element (not shown).
Figure 3 shows an electrically conductive building block with conductive plated metal areas (201 and 202) on the coupling cylinders (301) for cooperation with the coupling studs on another building element (not shown)

Preferably, the moulded part consists of a composition comprising a polymer and a metal compound having a spinel structure. This is advantageous as the moulded part can be manufactured using the standard moulding processes (1K-moulding process).
Generally, the composition comprising a polymer and a metal compound having a spinel structure includes a composition comprising a polymer and laser sensitive metal complex that may be activated when exposed to the laser light. In particular, the laser sensitive metal complex is a metal compound that is capable of being activated by electromagnetic radiation, thereby forming elemental metal nuclei.
The metal compound that is capable of being activated by radiation is a metal-containing (inorganic or organic) compound which as a consequence of absorption of electromagnetic radiation liberates metal in elemental form, in a chemical reaction. It is also possible that the electromagnetic radiation is not directly absorbed by the metal-containing compound, but is absorbed by other substances which then transfer the absorbed energy to the metal-containing compound and thus bring about the liberation of elemental metal. The electromagnetic radiation may be UV light (wavelength from 100 to 400 nm), visible light (wavelength from 400 to 800 nm), or infrared light (wavelength from 800 to 25 000 nm). Other preferred forms of radiation are X-rays, gamma rays, and particle beams (electron beams, [alpha]-particle beams, and [beta]-particle beams).
The metal compound is capable of being activated by electromagnetic radiation and thereby forming elemental metal nuclei within the composition. The metal compound capable of being activated by radiation is comprised of electrically non-conductive high-thermal-stability organic or inorganic metal compounds which are preferably insoluble and stable in aqueous acidic or alkaline metalizing baths. Particularly suitable compounds are those which absorb a very large proportion of the light at the wavelength of the incident light. Compounds of this type are described inEP-A-1 274 288. Preference is given here to compounds of metals of the d and f group of the Periodic Table of the Elements with non-metals. The metal-containing compounds are particularly preferably metal oxides, in particular oxides of the d-metals of the Periodic Table of the Elements. Higher metal oxides which contain at least two different kinds of cations and have a spinel structure or spinel-related structure, and which remain unchanged in non-irradiated areas of the moulded part that contains the composition of the present invention are particularly suitable. In one particularly preferred embodiment of the invention, the higher oxides are spinels, in particular copper-containing spinels, such as CuCr₂O₄. Suitable copper-containing spinels are commercially available, an example being PK 3095 from Ferro (DE) or 34E23 or 34E30 from Johnson Matthey (DE). Copper oxides of the formula CuO or Cu₂O are also particularly suitable, and use is preferably made here of nanoparticles, such as NANOARC(R) Copper Oxide from Nanophase Technologies Corporation, Illinois, USA. In another particularly preferred embodiment of the invention, the higher spinel oxide is a manganese-containing spinel. As will be understood by a man skilled in the art also a mixture of metal compounds having a spinel structure can be used.
Preferably, the metal compound is represented by the chemical formula AB₂O₄ or B(AB)O₄. The A component of the formulas is a metal cation having a valence of 2 and is selected from the group consisting of cadmium, zinc, copper, cobalt, magnesium, tin, titanium, iron, aluminum, nickel, manganese, chromium, and combinations of two or more of these. The B component of the formulas is a metal cation having a valence of 3 and is selected from the group consisting of cadmium, manganese, nickel, zinc, copper, cobalt, magnesium, tin, titanium, iron, aluminum, chromium, and combinations of two or more of these.
The building element according to the invention comprises a moulded part that comprises a layer consisting of a composition comprising polymer and metal compound having a spinel structure. Generally, such composition comprises polymer and laser sensitive metal complex that may be activated when exposed to the laser light. In a preferred embodiment, the polymer composition has dispersed therein metal compound(s), where the metal compound preferably comprises two or more metal oxide cluster configurations within a definable crystal formation. The overall crystal formation, when in an ideal (i.e., non-contaminated, non-derivative) state, has the following general formula:

AB₂O₄,

where

i. A is selected from the group consisting of cadmium, zinc, copper, cobalt, magnesium, tin, titanium, iron, aluminum, nickel, manganese, chromium, and combinations thereof, which provides the primary cation component of a first metal oxide cluster ("metal oxide cluster 1 ") typically a tetrahedral structure,
ii. B is selected from the group consisting of cadmium, manganese, nickel, zinc, copper, cobalt, magnesium, tin, titanium, iron, aluminum, chromium, and combinations thereof and which provides the primary cation component of a second metal oxide cluster ("metal oxide cluster 2") typically an octahedral structure,
iii. where within the above groups A or B, any metal cation having a possible valence of 2 can be used as an "A", and any metal cation having a possible valence of 3 can be used as a "B",
iv. where the geometric configuration of "metal oxide cluster 1" (typically a tetrahedral structure) is different from the geometric configuration of "metal oxide cluster 2" (typically an octahedral structure),
v. where a metal cation from A and B can be used as the metal cation of "metal oxide cluster 2" (typically the octahedral structure), as in the case of an 'inverse' spinel-type crystal structure,
vi. where O is primarily, if not exclusively, oxygen; and
vii. where the "metal oxide cluster 1" and "metal oxide cluster 2" together provide a singular identifiable crystal type structure having heightened susceptibility to electromagnetic radiation.

The concentration of these metal components present in the polymer composition is from 0.5 up to 20 mass%, preferably from 1 up to 20 mass%, preferably from 3 up to 10 mass%, more preferably from 4 up to 10 mass%, and particularly preferably from 5 up to 10 mass% (relative to the total polymer composition of the laser direct structuring material).
The polymer is preferably selected from the group consisting of polyamides, polyesters, polycarbonate, styrene containing polymers and blends thereof. More preferably, the polymer is selected from the group consisting of polyamides, polycarbonate, ABS and blends thereof.
The metal compound and optionally other compounds and additives may be introduced into the polymer by means of suitable mixing devices such as single-screw or twin-screw extruders, preferably a twin-screw extruder is used. Preferably, polymer pellets are introduced into the extruder together with at least the metal compound and extruded, then quenched in a water bath and then pelletized.
The invention relates in particular to building element that comprises a moulded part produced by injection moulding of the polymer composition as described above.
The invention further relates to a process for producing a building element according to the present invention which process comprises the steps of providing a composition comprising a polymer and a metal compound having a spinel structure, moulding said composition into a moulded part comprising a layer of said composition, irradiating areas of said layer with electromagnetic radiation to break down the metal compound and releasing metal nuclei (by chemical reduction), and subsequently metallizing the irradiated areas. Preferably, the process comprises the steps of providing a composition comprising a polymer and a metal compound having a spinel structure, moulding said composition into a moulded part, irradiating areas of said part with electromagnetic radiation to break down the metal compound and releasing metal nuclei (by chemical reduction), and subsequently metallizing the irradiated areas. In a preferred embodiment, electromagnetic radiation is used to simultaneously release metal nuclei and effect ablation of the part while forming an adhesion-promoting surface. This provides a simple means to achieve excellent adhesive strength of the deposited metallic conductor tracks. Advantageously, a laser is used to produce the electromagnetic radiation to release the metal nuclei. Thus, the electromagnetic radiation is preferably laser radiation. The wavelength of the laser is advantageously 248 nm, 308 nm, 355 nm, 532 nm, 1064 nm or of even 10600 nm. The deposition of further metal onto the metal nuclei generated by electromagnetic radiation preferably takes place via plating (solution-chemistry) processes. Said metallizing is preferably perfomed by immersing the moulded part in at least one electroless plating bath to form electrically conductive pathways on the irradiated areas of the moulded part.

Claims

Building element comprising a moulded part that further contains plated metal areas,characterized in that the moulded part comprising a layer consisting of a composition comprising a polymer and a metal compound having a spinel structure.
Building element according to claim 1,characterized in that the wall thickness of the moulded part is 5 mm or less.
Building element according to claim 1 or 2,characterized in that the moulded part consists of a composition comprising a polymer and a metal compound having a spinel structure.
Building element according to anyone of claims 1-3,characterized in that the plated metal areas are electrically conductive areas.
Building element according to anyone of claims 1-4,characterized in that the metal compound is capable of being activated by electromagnetic radiation, thereby forming elemental metal nuclei.
Building element according to anyone of claims1-5,chararacterized in that the metal compound is a metal oxide.
Building element according to anyone of claims 1-6,chararacterized in that the metal compound is a copper containing spinel.
Building element according to anyone of claims 1-7,chararacterized in that the polymer is selected from the group consisting of polyamides, polyesters, polycarbonate, styrene containing polymers and blends thereof.
Building element according to anyone of claims 1-7,chararacterized in that the polymer is selected from the group consisting of polyamides, polycarbonate, ABS and blends thereof.
Building element according to anyone of claims 1-9,chararacterized in that the building element is a toy building element.
Building element according to anyone of claims 1-10,chararacterized in that the moulded part is an injection moulded part
A process for producing building elements according to anyone of claims 1-11,characterized in that the process comprises the steps of providing a composition comprising a polymer and a metal compound having a spinel structure, moulding said composition to obtain a moulded part comprising a layer of said composition, irradiating areas of said layer with electromagnetic radiation, and subsequently metallizing the irradiated areas.