【０００１】[0001]
【産業上の利用分野】本発明は、熱可塑性重合体中に導
電粉を分散混合してなり、かつ正の温度特性を有する有
機抵抗体に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic resistor obtained by dispersing and mixing conductive powder in a thermoplastic polymer and having a positive temperature characteristic.
【０００２】[0002]
【従来の技術】一般に結晶性の熱可塑性重合体中に１種
またはそれ以上の導電性充填剤（導電フィラー）である
例えばカーボンブラック、または微粉化された金属を分
散させた有機抵抗体は正の温度特性を有し、セラミック
製の正の温度特性を有する抵抗体に比較し、比較的大電
流の用途に用いられる。そのうち、よく知られたものと
しては、特公昭６４−３３２２号公報に開示されている
ように、高密度ポリエチレンにカーボンブラックを導電
フィラーとしたものがある。また、導電フィラーとして
金属粉を用いる場合、例えば特開昭５６−１６１４６４
号公報に開示されているように、金属粉として、一般
に、Ag、Ni、Al等の低抵抗の金属が用いられている。2. Description of the Related Art Generally, one or more conductive fillers (conductive fillers) such as carbon black or an organic resistor in which a finely divided metal is dispersed in a crystalline thermoplastic polymer is positive. It has a temperature characteristic of, and is used for a relatively large current as compared with a resistor made of a ceramic and having a positive temperature characteristic. Among them, a well-known one is a high density polyethylene containing carbon black as a conductive filler, as disclosed in Japanese Patent Publication No. 64-3322. When metal powder is used as the conductive filler, for example, JP-A-56-161464
As disclosed in the publication, a low resistance metal such as Ag, Ni, Al is generally used as the metal powder.
【０００３】[0003]
【発明が解決しようとする課題】しかし、従来実用可能
な有機抵抗体（高密度ポリエチレン＋カーボンブラッ
ク）においては、室温比抵抗が２Ω・cmと大きく、金属
粉を導電フィラーを用いたものに比較し、大電流用途に
は不向きである。一方、金属粉を導電フィラーとして添
加した抵抗体は、初期比抵抗は低くできるものの、金属
表面の酸化により、特性が劣化し、実用に耐えられるも
のではなかった。この特性の劣化は、金属粉の充填率を
あげるためにその粒径を小さくするほど顕著になる。本
発明は、上記従来技術の問題点に鑑み、室温比抵抗を低
く抑えることができ、もって大電流用途に用いることが
可能になると共に、経時変化が小さく、実用に耐えられ
る正の温度特性を有する有機抵抗体を提供することを目
的とする。However, the organic resistor (high-density polyethylene + carbon black) that can be used conventionally has a large room temperature specific resistance of 2 Ω · cm, and is compared with a metal powder containing a conductive filler. However, it is not suitable for high current applications. On the other hand, although the resistance to which metal powder is added as a conductive filler can reduce the initial specific resistance, the characteristics are deteriorated due to the oxidation of the metal surface, and the resistance is not practical. This deterioration of the characteristics becomes more remarkable as the particle size is reduced in order to increase the filling rate of the metal powder. In view of the above-mentioned problems of the prior art, the present invention can suppress the room temperature specific resistance to a low level, and thus can be used for large current applications, has a small change over time, and has a positive temperature characteristic that can withstand practical use. It is an object to provide an organic resistor having the same.
【０００４】[0004]
【課題を解決するための手段】本発明は、上記目的を達
成するため、炭化物、ホウ化物、または窒化物を表面に
形成した導電性金属粉の１種以上のものを熱可塑性重合
体中に分散混合して正の温度特性を有する有機抵抗体を
構成したことを特徴とする。金属粉の炭化物、ホウ化
物、または窒化物をそのまま製品に用いると、比抵抗が
やや高くなるが、金属粉の表面処理によって金属粉の表
面のみにこれらの化合物を形成することにより、導電フ
ィラーとしての金属粉の抵抗の増大が低く抑えられると
共に、表面化合物が酸化防止膜としても作用する。すな
わち、本発明において用いられる金属粉は、その表面処
理により表面に前記化合物を形成する際に、その化合物
が導電性を持つことが必要である。より具体的には、金
属粉として、例えばTi、Zr、Hf、 V、Ta、Nb、W 、Cr等
が、表１で示すように、炭化物、ホウ化物または窒化物
として比抵抗の低いものが得易い点において好ましい。
例えばAlの窒化物（AlN ）等は比抵抗が２×１０17Ω・
cmとなり、絶縁物となるから、好ましくない。また、表
２は、表１の金属について、表面処理により粒子表面に
前記化合物を形成したものの比抵抗を示しており、表１
に示した金属粉は表面処理により比抵抗が１００μΩ・
cm以下のものが容易に得られる。In order to achieve the above object, the present invention provides a thermoplastic polymer with one or more conductive metal powders having carbides, borides, or nitrides formed on the surface thereof. It is characterized in that it is dispersed and mixed to form an organic resistor having a positive temperature characteristic. If the carbide, boride, or nitride of the metal powder is used in the product as it is, the specific resistance is slightly increased, but by forming these compounds only on the surface of the metal powder by the surface treatment of the metal powder, the conductive filler is used. The increase in resistance of the metal powder is suppressed to a low level, and the surface compound also functions as an antioxidant film. That is, the metal powder used in the present invention is required to have conductivity when the compound is formed on the surface by the surface treatment. More specifically, as the metal powder, for example, Ti, Zr, Hf, V, Ta, Nb, W, Cr, etc., and as shown in Table 1, those having a low specific resistance such as carbide, boride or nitride are used. It is preferable because it is easy to obtain.
For example, Al nitride (AlN) has a resistivity of 2 × 1017 Ω ・
It becomes cm and becomes an insulator, which is not preferable. Table 2 shows the specific resistance of the metal of Table 1 in which the compound is formed on the particle surface by the surface treatment.
The surface resistance of the metal powder shown in is 100μΩ.
It is easy to obtain those with a size of less than cm.
【０００６】[0006]
【表１】[Table 1]
【０００７】[0007]
【表２】[Table 2]
【０００８】本発明において、混合する金属粉の好まし
い平均粒径は、０．５μｍ〜５０μｍ、より好ましくは
１．０μｍ〜２０μｍである。粒径が小さ過ぎると凝集
もしくは発火のおそれがある上、取扱いが困難となり、
また大き過ぎると室温における比抵抗が大となる。ま
た、室温における比抵抗を所定以下の値にするには、表
面処理された金属粉（導電フィラー）の充填率は少なく
とも１０体積％あり、また室温比抵抗と最大比抵抗との
比である抵抗変化率（後述の（１）式で表示される）と
して所定値以上の値を得るには、７０体積％以下である
ことが好ましい。また、室温比抵抗と抵抗変化率の双方
についてより満足すべき値を得るには、導電フィラー充
填率はより好ましくは２０体積％〜５０体積％、さらに
好ましくは３０体積％〜４０体積％である。In the present invention, the average particle size of the metal powder to be mixed is preferably 0.5 μm to 50 μm, more preferably 1.0 μm to 20 μm. If the particle size is too small, there is a risk of aggregation or ignition, and handling becomes difficult,
If it is too large, the specific resistance at room temperature becomes large. Further, in order to bring the resistivity at room temperature to a predetermined value or less, the filling factor of the surface-treated metal powder (conductive filler) is at least 10% by volume, and the resistivity which is the ratio of the room temperature resistivity and the maximum resistivity. In order to obtain a value higher than a predetermined value as the rate of change (displayed by the formula (1) described later), it is preferably 70% by volume or less. Further, in order to obtain more satisfactory values for both the room temperature specific resistance and the resistance change rate, the conductive filler filling rate is more preferably 20% by volume to 50% by volume, and further preferably 30% by volume to 40% by volume. .
【０００９】また、本発明において用いる熱可塑性重合
体としては、結晶性の高密度ポリエチレン、ポリプロピ
レン、ナイロン６、ナイロン６６等のナイロン、ポリア
セタール、ポリ塩化ビニル、ポリ塩化ビニリデン、ポリ
フッ化ビニリデン、ポリ四フッ化エチレン、ポリエチレ
ンテレフタレート等のポリエステル等が挙げられ、なか
でもポリフツ化ビニリデンまたは高密度ポリエチレンが
好ましい。本出願人は既に、特開平２−１４０９０２号
公報において、ポリフツ化ビニリデンまたは高密度ポリ
エチレンに対し架橋剤としてシラン化合物を用い、架橋
化物を構成することにより、熱サイクルに強い抵抗体が
得られることを報告しており、また、特公平４−１１５
７５号公報においては、ポリフツ化ビニリデンにシラン
化合物を遊離基発生剤の存在下にグラフトさせた後、シ
ラノール縮合触媒の存在下に水あるいは水系媒体と接触
させることにより、架橋ポリフツ化ビニリデンを得る技
術について開示しており、この方法によれば、高架橋度
で耐熱性、耐水性、耐薬品性の点で優れたものが得られ
る。また、これらの重合体は少なくとも１０％の結晶度
を持つことが好ましい。As the thermoplastic polymer used in the present invention, crystalline high density polyethylene, nylon such as polypropylene, nylon 6, nylon 66, polyacetal, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, and polytetrafluoroethylene are used. Examples thereof include polyesters such as fluorinated ethylene and polyethylene terephthalate. Among them, polyvinylidene fluoride or high density polyethylene is preferable. The applicant already disclosed in JP-A-2-140902 that a silane compound is used as a cross-linking agent for polyvinylidene fluoride or high-density polyethylene to form a cross-linked product, whereby a strong resistance to heat cycle can be obtained. In addition, Japanese Patent Publication No. 4-115
In JP-A-75, a technique for obtaining a crosslinked vinylidene fluoride by contacting polyvinylidene fluoride with a silane compound in the presence of a free radical generator and then contacting it with water or an aqueous medium in the presence of a silanol condensation catalyst. According to this method, a product having a high degree of crosslinking and excellent heat resistance, water resistance, and chemical resistance can be obtained. Also, these polymers preferably have a crystallinity of at least 10%.
【００１０】[0010]
【作用】本発明においては、導電フィラーとしてカーボ
ンブラックに比較して低い比抵抗を有する金属粉を用い
たので、比抵抗の低い抵抗体が得られると共に、表面が
炭化物、ホウ化物、または窒化物となるように表面処理
を行ったので、金属粉の酸化が防止され、金属粉の抵抗
増加による特性の劣化が防止される。In the present invention, since metal powder having a lower specific resistance than carbon black is used as the conductive filler, a resistor having a low specific resistance can be obtained, and the surface thereof is a carbide, boride, or nitride. Since the surface treatment is performed so as to prevent the metal powder from being oxidized, deterioration of the characteristics due to an increase in resistance of the metal powder is prevented.
【００１１】[0011]
【実施例】図１（Ａ）は本発明により作製した有機抵抗
体の構造例を示す断面図であり、１は本発明による抵抗
体、２はその両面に被着したNi等からなる電極、３は各
電極２に半田付け等により固定したリード線、４はこれ
らの部材をリード線３の引き出し部を除いて一体に覆う
ように成形したエポキシ樹脂等でなるモールド樹脂であ
る。図１（Ｂ）は本発明において用いる金属粉を概念的
に説明する図であり、金属粉５の表面処理により、炭化
物、ホウ化物、または窒化物でなる表面層５ａを形成し
たものである。EXAMPLE FIG. 1 (A) is a cross-sectional view showing a structural example of an organic resistor manufactured according to the present invention, in which 1 is a resistor according to the present invention, 2 is an electrode made of Ni or the like deposited on both surfaces thereof, Reference numeral 3 is a lead wire fixed to each electrode 2 by soldering or the like, and 4 is a molding resin made of epoxy resin or the like formed so as to integrally cover these members excluding the lead wire 3. FIG. 1B is a diagram conceptually explaining the metal powder used in the present invention, in which a surface layer 5a made of carbide, boride, or nitride is formed by the surface treatment of the metal powder 5.
【００１２】［Ti粉の窒化処理の例］ 金属Ti粉を窒化処理した導電フィラーの実施例について
説明する。窒化処理は、平均粒径が１．０μｍのTi粉を
８００℃の窒素還元雰囲気において１０分間処理するこ
とにより行った。このようにして窒化処理したTi粉の比
抵抗は５９μΩ・cmであった。窒化処理したTi粉１１０
ｇをマトリックス材となる粒状ポリフッ化ビニリデン１
００ｇに２００℃で加熱したニーダーで混練した。さら
に遊離基発生剤としての液状のジクミルパーオキサイド
０．５ｇを溶解した架橋剤としてのシラン化合物の１種
である液状のビニルトリメトキシシラン５ｇを加えて混
練した後、混練物を２００℃にてプレス成形してシート
状にした。[Example of nitriding treatment of Ti powder] An example of a conductive filler obtained by nitriding metal Ti powder will be described. The nitriding treatment was performed by treating Ti powder having an average particle size of 1.0 μm in a nitrogen reducing atmosphere at 800 ° C. for 10 minutes. The resistivity of the Ti powder thus nitrided was 59 μΩ · cm. Ni powder 110
Grained polyvinylidene fluoride 1 as matrix material
It was kneaded with 00 g in a kneader heated at 200 ° C. Further, 5 g of liquid vinyltrimethoxysilane, which is one kind of silane compound as a cross-linking agent, in which 0.5 g of liquid dicumyl peroxide as a free radical generator is dissolved is added and kneaded, and then the kneaded product is heated to 200 ° C. And press formed into a sheet.
【００１３】このようにして得た成形物をシラノール縮
合触媒であるジブチルスズラウレートを１０％含有した
水性懸濁液５００mlに浸漬し、８０℃で２４時間架橋反
応（シラノール縮合反応）させ、架橋ポリフッ化ビニリ
デンを生成させた。このようにして得られる抵抗体のTi
粉の充填率は約３０体積％である。The molded product thus obtained is immersed in 500 ml of an aqueous suspension containing 10% of dibutyltin laurate, which is a silanol condensation catalyst, and subjected to a crosslinking reaction (silanol condensation reaction) at 80 ° C. for 24 hours to obtain a crosslinked polyfluoride. Vinylidene chloride was produced. Ti of the resistor obtained in this way
The filling factor of the powder is about 30% by volume.
【００１４】その後、図１（Ａ）に示した電極２として
のNi金属箔を加熱加圧接着した。このときのシートの厚
みは０．７mm、Ni箔の厚みは３０μｍとした。その後、
このシートを１０mmの直径の円形に打ち抜き、この電極
２にリード線３を半田付けし、室温から１８０℃にわた
って５分で昇温、続いて室温まで５分で降温させて抵抗
の変化を測定する試験を繰り返し、特性の劣化を見た。
図２はこのようなサイクル試験の結果を示すグラフであ
る。Thereafter, the Ni metal foil as the electrode 2 shown in FIG. 1 (A) was heated and pressure-bonded. At this time, the thickness of the sheet was 0.7 mm, and the thickness of the Ni foil was 30 μm. afterwards,
This sheet is punched out into a circle with a diameter of 10 mm, the lead wire 3 is soldered to the electrode 2, the temperature is raised from room temperature to 180 ° C. in 5 minutes, and then the temperature is lowered to room temperature in 5 minutes to measure the change in resistance. The test was repeated and the deterioration of the characteristics was observed.
FIG. 2 is a graph showing the results of such a cycle test.
【００１５】［比較例：未処理金属粉のみ］ 比較例として、平均粒径が１．０μｍのTi粉を導電フィ
ラーとし、このTi粉を表面処理せずそのまま用い、前記
と同様の製法ならびに導電フィラー充填率で有機抵抗
体を作製し、前記と同様の熱サイクル試験を行った。そ
の熱サイクル試験の結果を図３に示し、また、試験前の
抵抗変化率（下記の（１）式で示す）と、熱サイクル試
験前と、１００回の熱サイクル繰り返し後の２５℃にお
ける比抵抗を、前記窒化処理Ti粉を導電フィラーとして
使用した場合と対比して表３に示す。 抵抗変化率（桁）＝Log(Rmax/R25）……（１） （ただし、ＲmaxとＲ25はそれぞれ最大比抵抗、温度２
５℃における比抵抗を表す。）[Comparative Example: Only untreated metal powder] As a comparative example, Ti powder having an average particle size of 1.0 μm was used as a conductive filler, and this Ti powder was used as it was without surface treatment. An organic resistor was prepared with the filler filling rate, and the same thermal cycle test as described above was performed. The results of the heat cycle test are shown in FIG. 3, and the resistance change rate before the test (shown by the following equation (1)) and the ratio at 25 ° C. before the heat cycle test and after 100 heat cycle repetitions are shown. The resistance is shown in Table 3 in comparison with the case where the nitriding Ti powder is used as a conductive filler. Resistance change rate (digit) = Log (Rmax / R25 ) …… (1) (However, Rmax and R25 are maximum specific resistance and temperature 2 respectively.
Indicates the specific resistance at 5 ° C. )
【００１６】[0016]
【表３】[Table 3]
【００１７】図３に示すように、表面処理しないTi粉を
用いたものにおいては、１００回の熱サイクル試験後、
室温における比抵抗が試験前の値の約１０倍程度に増大
した。一方、窒化処理Ti粉による場合には、室温におけ
る比抵抗が金属Ti粉の場合とあまり変わらないほど低
く、従ってカーボンブラックを導電として使用する場合
に比較して室温比抵抗が格段に低く、しかも１００回の
熱サイクル試験後も室温における比抵抗は試験前とほと
んど変わらなかった。このような結果から、本発明によ
る表面処理により金属粉の酸化を防止すれば、特性の劣
化を防止でき、大電流用として実用に供することができ
ることが分かる。As shown in FIG. 3, in the case of using the Ti powder without surface treatment, after 100 thermal cycle tests,
The specific resistance at room temperature increased to about 10 times the value before the test. On the other hand, in the case of using the nitriding Ti powder, the resistivity at room temperature is so low that it is not so different from that of the metal Ti powder, and therefore the resistivity at room temperature is remarkably low as compared with the case of using carbon black as a conductive material. After 100 heat cycle tests, the resistivity at room temperature was almost the same as before the test. From such a result, it can be seen that if the metal powder is prevented from being oxidized by the surface treatment according to the present invention, the deterioration of the characteristics can be prevented and the metal powder can be practically used for a large current.
【００１８】［Ti粉の窒化処理の例］ Tiを金属粉として用い、これを炭化処理した実施例につ
いて説明する。炭化処理は、平均粒径が１．０μｍのTi
粉をカーボンと混合し、水素雰囲気下１５００℃で加熱
処理することにより行った。その他、比較例として、導
電フィラーとして金属粉と同径のTiC 粉（粒子全体がTi
C でなるもの）を用い、と同様の製法ならびに導電フ
ィラー充填率で作製したものについて試験を行った結果
を表４に示す。[Example of nitriding treatment of Ti powder] An example in which Ti is used as a metal powder and carbonized is described. The carbonization treatment is performed with Ti having an average particle size of 1.0 μm.
The powder was mixed with carbon and heat-treated at 1500 ° C. in a hydrogen atmosphere. In addition, as a comparative example, as a conductive filler, TiC powder with the same diameter as the metal powder
Table 4 shows the results of the tests conducted on the products prepared by the same manufacturing method as above and the conductive filler filling rate.
【００１９】[0019]
【表４】[Table 4]
【００２０】表４から明らかなように、TiC 粉を用いた
場合には、１００回の熱サイクル繰り返し後の特性の劣
化は少ないものの、２５℃における比抵抗が高くなり、
大電流の用途には向かない。一方、炭化表面処理したTi
粉においては、２５℃における比抵抗はTiC 粉の場合よ
りはるかに低く、１００回の熱サイクル試験後の比抵抗
の増加も、表３に示した金属Tiの場合よりはるかに小さ
い。As is apparent from Table 4, when TiC powder was used, the characteristic resistance after 100 thermal cycles was small, but the specific resistance at 25 ° C. was high.
Not suitable for high current applications. On the other hand, Ti with carbonized surface treatment
In the powder, the specific resistance at 25 ° C. is much lower than that of the TiC powder, and the increase in the specific resistance after 100 thermal cycle tests is also much smaller than that of the metallic Ti shown in Table 3.
【００２１】［導電フィラー充填率の検討］ 平均粒径が１．０μｍのTi粉をで記載のように窒化処
理したものについて、重合体に対する窒化Ti粉の充填率
（体積％）を種々に変化させ、他の製法はと同様にし
て抵抗体を作製し、２５℃における比抵抗と抵抗変化率
を調べた。その結果を表５に示す。（以下余白）[Study of Filling Ratio of Conductive Filler] With respect to the Ti powder having an average particle diameter of 1.0 μm and subjected to the nitriding treatment as described in, the filling ratio (volume%) of the Ti nitride powder with respect to the polymer was variously changed. Then, a resistor was manufactured in the same manner as in the other manufacturing methods, and the specific resistance and the resistance change rate at 25 ° C. were examined. The results are shown in Table 5. (Below margin)
【００２２】[0022]
【表５】[Table 5]
【００２３】表５から明らかなように、室温における比
抵抗が約１０Ω・cm以下でしかも約５桁以上の抵抗変化
率を得るには、導電フィラー充填率が１０体積％以上で
７０体積％以下であることが好ましい。また、室温にお
ける比抵抗と抵抗変化率の双方について、導電フィラー
充填率の望ましい値は、２０体積％〜５０体積％、さら
に好ましくは３０体積％〜４０体積％である。As is clear from Table 5, in order to obtain a resistivity change rate at room temperature of about 10 Ω · cm or less and a resistance change rate of about 5 digits or more, the conductive filler filling rate is 10 volume% or more and 70 volume% or less. Is preferred. Further, with respect to both the specific resistance and the resistance change rate at room temperature, the desirable value of the conductive filler filling rate is 20% by volume to 50% by volume, more preferably 30% by volume to 40% by volume.
【００２４】［導電フィラーの粒径の検討］ 前記Ti粉の窒化処理したものにおいて、Ti粉の粒径のみ
を０．５μｍ〜５０μｍに変化させ、前記同様に導電フ
ィラー充填率を３０体積％とし、前記と同様の製法に
よって抵抗体を作製した場合における２５℃における比
抵抗と抵抗変化率を測定した。その結果を表６に示す。
（以下余白）[Study of Particle Size of Conductive Filler] In the nitriding treatment of the Ti powder, only the particle size of the Ti powder was changed to 0.5 μm to 50 μm, and the conductive filler filling rate was set to 30% by volume in the same manner as above. The specific resistance and the resistance change rate at 25 ° C. in the case where the resistor was manufactured by the same manufacturing method as described above were measured. The results are shown in Table 6.
(Below margin)
【００２５】[0025]
【表６】[Table 6]
【００２６】表６から、０．５μｍ〜５０μｍの範囲に
おいては、抵抗変化率の面では約５以上の値は得られる
ものの、２５℃における比抵抗においては、２Ω・cm未
満の比抵抗を得るには導電フィラーの平均粒径は２０μ
ｍ以下であることが好ましいことが分かる。From Table 6, in the range of 0.5 μm to 50 μm, although a value of about 5 or more can be obtained in terms of the rate of change in resistance, the specific resistance at 25 ° C. is less than 2 Ω · cm. The average particle size of the conductive filler is 20μ
It can be seen that it is preferably m or less.
【００２７】［他の金属粉の例］ V、W、Crの窒化物を前記TiN と同様に作製し、それぞれ導
電フィラーの材質以外は前記と同様の製法により抵抗
体を作製し、抵抗体の２５℃における比抵抗、抵抗変化
率を測定した。その結果について表７に示す。表７中、
導電フィラー充填率は体積％である。[Examples of other metal powders] V, W, and Cr nitrides were prepared in the same manner as TiN, and a resistor was prepared by the same method as above except for the material of the conductive filler. The specific resistance and resistance change rate at 25 ° C. were measured. The results are shown in Table 7. In Table 7,
The filling rate of the conductive filler is% by volume.
【００２８】[0028]
【表７】[Table 7]
【００２９】また、前記重合体としてポリフッ化ビニリ
デンの代わりに高密度ポリエチレンを用い、導電フィラ
ーを前記窒化処理した１．０μｍのTi粉を用い、充填率
も前記と同様に３０体積％として前記同様の製法により
２５℃における比抵抗を測定したところ、0.12Ω・cmと
なり、 また、抵抗変化率は5.8 となり、満足すべき値で
あった。Further, as the polymer, high-density polyethylene was used in place of polyvinylidene fluoride, 1.0 μm Ti powder obtained by nitriding the conductive filler was used, and the filling rate was 30% by volume as in the above. When the specific resistance at 25 ° C. was measured by the manufacturing method of No. 1, it was 0.12 Ω · cm, and the resistance change rate was 5.8, which was a satisfactory value.
【００３０】[0030]
【発明の効果】請求項１によれば、導電フィラーとして
カーボンブラックに比較して低い比抵抗を有する金属粉
を用いたので、比抵抗の低い抵抗体が得られると共に、
表面が炭化物、ホウ化物、または窒化物となるように表
面処理を行ったので、導電フィラーの比抵抗の増大が抑
えられ、大電流用の正の抵抗特性を有する有機抵抗体が
提供可能になると共に、金属粉の酸化が防止され、金属
粉の抵抗増加による特性の劣化が防止されるので、大電
流用として十分実用に供し得るものが提供できる。請求
項２によれば、導電フィラーとして比抵抗の低い材料が
用いたため、より比抵抗の低い抵抗体が得られる。請求
項３によれば、導電フィラーの充填率を上記範囲内に設
定したため、室温における比抵抗と抵抗変化率の双方の
面で十分な特性の抵抗体が得られる。請求項４によれ
ば、マトリックスを構成する重合体を上記材質のものに
したことにより、導電フィラーのみならず、マトリック
スの面からも熱サイクルによる特性劣化の少ない抵抗体
が提供できる。According to the first aspect of the present invention, since metal powder having a lower specific resistance than carbon black is used as the conductive filler, a resistor having a low specific resistance can be obtained, and
Since the surface treatment is performed so that the surface becomes a carbide, boride, or nitride, it is possible to suppress an increase in the specific resistance of the conductive filler and to provide an organic resistor having a positive resistance characteristic for a large current. At the same time, oxidation of the metal powder is prevented, and deterioration of the characteristics due to an increase in resistance of the metal powder is prevented, so that a product that can be sufficiently put into practical use for a large current can be provided. According to the second aspect, since a material having a low specific resistance is used as the conductive filler, a resistor having a lower specific resistance can be obtained. According to the third aspect, since the filling rate of the conductive filler is set within the above range, it is possible to obtain a resistor having sufficient characteristics in terms of both the specific resistance at room temperature and the rate of resistance change. According to the fourth aspect, since the polymer constituting the matrix is made of the above-mentioned material, it is possible to provide a resistor which is less likely to be deteriorated in characteristics due to thermal cycles not only from the conductive filler but also from the surface of the matrix.
【図１】（Ａ）は本発明において作製される抵抗体の一
例を示す断面図、（Ｂ）は本発明における導電フィラー
の粉１個の構造を概念的に示す断面図である。FIG. 1A is a sectional view showing an example of a resistor produced in the present invention, and FIG. 1B is a sectional view conceptually showing the structure of one conductive filler powder in the present invention.
【図２】本発明において、Ti粉を窒化処理した導電フィ
ラーを用いた場合の熱サイクル試験における抵抗値の変
化を示すグラフである。FIG. 2 is a graph showing a change in resistance value in a heat cycle test when a conductive filler obtained by nitriding Ti powder is used in the present invention.
【図３】従来のようにTi粉をそのまま導電フィラーとし
て用いた場合の熱サイクル試験における抵抗値の変化を
示すグラフである。FIG. 3 is a graph showing a change in resistance value in a heat cycle test when Ti powder is used as it is as a conductive filler as in the prior art.
１：抵抗体 ２：電極 ３：リード線 ４：モールド樹
脂 ５：金属粉 ５ａ：表面処理により生成した化合物1: Resistor 2: Electrode 3: Lead wire 4: Mold resin 5: Metal powder 5a: Compound produced by surface treatment
フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｃ０８Ｌ 101/00 Ｈ０１Ｂ 1/22 ＣContinuation of the front page (51) Int.Cl.6 Identification number Office reference number FI technical display location C08L 101/00 H01B 1/22 C
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7939094AJPH07263202A (en) | 1994-03-25 | 1994-03-25 | Organic resistor having positive temperature characteristics |
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7939094AJPH07263202A (en) | 1994-03-25 | 1994-03-25 | Organic resistor having positive temperature characteristics |
| Publication Number | Publication Date |
|---|---|
| JPH07263202Atrue JPH07263202A (en) | 1995-10-13 |
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7939094AWithdrawnJPH07263202A (en) | 1994-03-25 | 1994-03-25 | Organic resistor having positive temperature characteristics |
| Country | Link |
|---|---|
| JP (1) | JPH07263202A (en) |
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| EP0866471A1 (en)* | 1997-02-28 | 1998-09-23 | Mitsubishi Denki Kabushiki Kaisha | Polymeric PTC composition and circuit protection device made from the same |
| CN100428374C (en)* | 2001-10-12 | 2008-10-22 | 株式会社Ceratech | Polymerized positive temperature coefficiency device capable of returning to initial resistance after over current flow protection |
| JP2015506579A (en)* | 2011-12-31 | 2015-03-02 | 上海長園維安電子線路保護有限公司 | Polymer conductive composite material and PTC element |
| WO2018080441A1 (en)* | 2016-10-25 | 2018-05-03 | Hewlett-Packard Development Company, L.P. | Temperature sensors |
| Publication number | Priority date | Publication date | Assignee | Title |
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| EP0866471A1 (en)* | 1997-02-28 | 1998-09-23 | Mitsubishi Denki Kabushiki Kaisha | Polymeric PTC composition and circuit protection device made from the same |
| CN100428374C (en)* | 2001-10-12 | 2008-10-22 | 株式会社Ceratech | Polymerized positive temperature coefficiency device capable of returning to initial resistance after over current flow protection |
| JP2015506579A (en)* | 2011-12-31 | 2015-03-02 | 上海長園維安電子線路保護有限公司 | Polymer conductive composite material and PTC element |
| WO2018080441A1 (en)* | 2016-10-25 | 2018-05-03 | Hewlett-Packard Development Company, L.P. | Temperature sensors |
| US11199456B2 (en) | 2016-10-25 | 2021-12-14 | Hewlett-Packard Development Company, L.P. | Temperature sensors |
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| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Withdrawal of application because of no request for examination | Free format text:JAPANESE INTERMEDIATE CODE: A300 Effective date:20010605 |