JPH0794018A - Conductive compound - Google Patents
Conductive compoundInfo
- Publication number
- JPH0794018A JPH0794018A JP26196893A JP26196893A JPH0794018A JP H0794018 A JPH0794018 A JP H0794018A JP 26196893 A JP26196893 A JP 26196893A JP 26196893 A JP26196893 A JP 26196893A JP H0794018 A JPH0794018 A JP H0794018A
- Authority
- JP
- Japan
- Prior art keywords
- resistance
- molecular weight
- conductive composite
- conductive
- glassy carbon
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 150000001875 compounds Chemical class 0.000 title abstract 3
- 229910021397 glassy carbon Inorganic materials 0.000 claims abstract description 18
- 239000004699 Ultra-high molecular weight polyethylene Substances 0.000 claims description 15
- 229920000785 ultra high molecular weight polyethylene Polymers 0.000 claims description 15
- 241000120529 Chenuda virus Species 0.000 claims 1
- 239000004020 conductor Substances 0.000 claims 1
- 239000002245 particle Substances 0.000 abstract description 14
- 238000010438 heat treatment Methods 0.000 abstract description 6
- 238000002156 mixing Methods 0.000 abstract description 6
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 abstract description 4
- 239000003963 antioxidant agent Substances 0.000 abstract description 2
- 230000003078 antioxidant effect Effects 0.000 abstract description 2
- 229910000019 calcium carbonate Inorganic materials 0.000 abstract description 2
- 239000000945 filler Substances 0.000 abstract description 2
- 235000010216 calcium carbonate Nutrition 0.000 abstract 1
- 239000000314 lubricant Substances 0.000 abstract 1
- 239000002131 composite material Substances 0.000 description 40
- 239000000203 mixture Substances 0.000 description 16
- 238000003825 pressing Methods 0.000 description 13
- 238000012360 testing method Methods 0.000 description 10
- 239000000843 powder Substances 0.000 description 7
- 239000006229 carbon black Substances 0.000 description 5
- 238000000465 moulding Methods 0.000 description 5
- 238000005259 measurement Methods 0.000 description 4
- -1 polyethylene Polymers 0.000 description 4
- 239000004698 Polyethylene Substances 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 229920000573 polyethylene Polymers 0.000 description 3
- 229920000642 polymer Polymers 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 238000000748 compression moulding Methods 0.000 description 2
- NNBZCPXTIHJBJL-UHFFFAOYSA-N decalin Chemical compound C1CCCC2CCCCC21 NNBZCPXTIHJBJL-UHFFFAOYSA-N 0.000 description 2
- 238000010894 electron beam technology Methods 0.000 description 2
- 150000001451 organic peroxides Chemical class 0.000 description 2
- 239000005011 phenolic resin Substances 0.000 description 2
- SGTNSNPWRIOYBX-UHFFFAOYSA-N 2-(3,4-dimethoxyphenyl)-5-{[2-(3,4-dimethoxyphenyl)ethyl](methyl)amino}-2-(propan-2-yl)pentanenitrile Chemical compound C1=C(OC)C(OC)=CC=C1CCN(C)CCCC(C#N)(C(C)C)C1=CC=C(OC)C(OC)=C1 SGTNSNPWRIOYBX-UHFFFAOYSA-N 0.000 description 1
- 239000004677 Nylon Substances 0.000 description 1
- 241000282320 Panthera leo Species 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 229920001940 conductive polymer Polymers 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- XPFVYQJUAUNWIW-UHFFFAOYSA-N furfuryl alcohol Chemical compound OCC1=CC=CO1 XPFVYQJUAUNWIW-UHFFFAOYSA-N 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 238000001746 injection moulding Methods 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 229920001778 nylon Polymers 0.000 description 1
- 229920000620 organic polymer Polymers 0.000 description 1
- 239000008188 pellet Substances 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- 229920001187 thermosetting polymer Polymers 0.000 description 1
- PXXNTAGJWPJAGM-UHFFFAOYSA-N vertaline Natural products C1C2C=3C=C(OC)C(OC)=CC=3OC(C=C3)=CC=C3CCC(=O)OC1CC1N2CCCC1 PXXNTAGJWPJAGM-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Manufacture Of Macromolecular Shaped Articles (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Conductive Materials (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、耐電圧に優れ、極めて
狭い温度範囲において抵抗の最大変化率が極めて大きい
という正特性温度係数（以下、ＰＴＣという）を有する
導電性複合体に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive composite having a positive temperature coefficient (hereinafter referred to as PTC) which is excellent in withstand voltage and has a very large maximum change rate of resistance in an extremely narrow temperature range. .
【０００２】[0002]
【従来の技術】ＰＴＣとは、特定の温度領域において、
その電気抵抗値が温度の上昇と共に急激に増加する性質
のことであり、従来ＰＴＣの性質を有する導電性組成物
としては、ポリエチレンやポリプロピレンあるいはナイ
ロンなどの結晶性ポリマーにカーボンブラックや金属粉
末を充填した導電性組成物が知られている。例えば、特
開昭６１−２１８１１７号公報には、分子量２０〜４０
万のポリエチレンとカーボンブラックを混合しペレット
化した後、射出成形法により得られた成形物に電子線を
照射して得た、ＰＴＣの性質を有する導電性組成物が開
示されている。また、特開昭６２−１６７３５８号公報
には、ポリエチレン等の有機高分子とカーボンブラック
を溶融混合し、それを微粉砕し電子線を照射した後、マ
トリックスポリマーとブレンドして成形し、さらに電子
線を照射して得た、ＰＴＣの性質を有する導電性ポリマ
ー組成物が開示されている。また、特開平１−１１０７
０２号公報には、グラファイトやカーボンブラックの存
在下で結晶性高分子物質を混練する際に、有機過酸化物
を添加し、この有機過酸化物の熱分解以上で混練してグ
ラフト化させることによりＰＴＣ特性を繰り返した後も
抵抗値が安定している過電流保護素子が開示されてい
る。さらに、特開平４−９６２０２号公報には、超高分
子量ポリオレフィンと微粒状グラッシーカーボンとから
なり、電気抵抗値が正特性温度係数を有する導電性複合
体が開示されている。2. Description of the Related Art PTC is a specific temperature range
The electric resistance value of the conductive composition rapidly increases as the temperature rises. As a conductive composition having the conventional PTC property, crystalline polymer such as polyethylene, polypropylene or nylon is filled with carbon black or metal powder. Conductive compositions are known. For example, JP-A-61-218117 discloses a molecular weight of 20-40.
There is disclosed a conductive composition having the property of PTC, which is obtained by irradiating a molded product obtained by injection molding with an electron beam after mixing polyethylene and carbon black into pellets. Further, in JP-A-62-167358, an organic polymer such as polyethylene and carbon black are melt-mixed, finely pulverized and irradiated with an electron beam, and then blended with a matrix polymer to be molded, and then an electron A conductive polymer composition having the properties of PTC, obtained by irradiation with rays, is disclosed. In addition, JP-A 1-1107
No. 02 discloses that when a crystalline polymer substance is kneaded in the presence of graphite or carbon black, an organic peroxide is added, and kneading and grafting are performed by thermal decomposition of the organic peroxide or more. Discloses an overcurrent protection element having a stable resistance value after repeating PTC characteristics. Further, Japanese Patent Application Laid-Open No. 4-96202 discloses a conductive composite composed of ultra-high molecular weight polyolefin and fine granular glassy carbon and having an electric resistance value having a positive temperature coefficient.
【０００３】[0003]
【発明が解決しようとする課題】しかし、上記の従来の
ものは、いずれの場合にも、抵抗の変化する温度範囲が
広く、周囲の温度の影響を受けやすいという欠点を有し
ていた。本発明の目的は、極めて狭い温度範囲において
抵抗の最大変化率が極めて大きいというＰＴＣ特性を有
する導電性複合体を提供することにある。However, in any case, the above-mentioned conventional ones have a drawback that the temperature range in which the resistance changes is wide and is easily influenced by the ambient temperature. An object of the present invention is to provide a conductive composite having a PTC characteristic that the maximum rate of change in resistance is extremely large in an extremely narrow temperature range.
【０００４】[0004]
【課題を解決するための手段】本発明者らは、上記課題
を解決すべく鋭意研究した結果、超高分子量ポリエチレ
ンと、粒状グラッシーカーボンとからなる導電性複合体
により、上記の課題が解決できることを見い出し、本発
明に到達したものである。すなわち、本発明は、超高分
子量ポリエチレンと粒状グラッシーカーボンとからな
り、１２５〜１４０℃の温度範囲において抵抗の最大変
化率が１×１０5 以上のＰＴＣを有することを特徴とす
る導電性複合体を要旨とするものである。Means for Solving the Problems As a result of intensive studies to solve the above problems, the inventors of the present invention have found that the above problems can be solved by a conductive composite composed of ultrahigh molecular weight polyethylene and granular glassy carbon. They have found the present invention and reached the present invention. That is, the present invention is a conductive composite comprising ultra-high molecular weight polyethylene and granular glassy carbon, and having a PTC having a maximum resistance change rate of 1 × 10 5 or more in a temperature range of 125 to 140 ° C. Is the gist.
【０００５】以下、本発明を詳細に説明する。本発明の
導電性複合体は、超高分子量ポリエチレンと粒状グラッ
シーカーボンとからなり、粒状グラッシーカーボンの含
有量としては、２０〜８０重量％が好ましく、特に３０
〜６０重量％が好ましい。グラッシーカーボンの含有量
が２０重量％未満では充分な導電性が得られ難く、８０
重量％を超えると複合体の強度が弱くなる傾向にあり、
好ましくない。The present invention will be described in detail below. The conductive composite of the present invention is composed of ultra-high molecular weight polyethylene and granular glassy carbon, and the content of the granular glassy carbon is preferably 20 to 80% by weight, particularly 30.
-60% by weight is preferred. If the glassy carbon content is less than 20% by weight, it is difficult to obtain sufficient conductivity.
If the content exceeds 10% by weight, the strength of the composite tends to be weak,
Not preferable.
【０００６】本発明で用いられる超高分子量ポリエチレ
ンとは、デカリン溶媒中（１３５℃）で測定した分子量
が１００万以上のものをいい、特に１００万以上、６０
０万以下のものが好ましい。分子量が１００万未満であ
ると得られた複合体の強度が充分でなく、６００万を超
えると成形が困難になることがある。本発明で用いられ
る超高分子量ポリエチレンとしては、例えば、平均粒子
径が５〜８００μｍのものが使用され、特に１０〜１０
０μｍのものが好ましい。平均粒子径が５μｍ未満のも
のは二次凝集をおこしやすく、８００μｍを超えるもの
を使用すると充分な強度を有する複合体が得られにくく
なる。本発明で用いられる粒状グラッシーカーボンとし
ては、フルフリルアルコール樹脂、フェノール樹脂等の
熱硬化性樹脂を原料として炭素化又は黒鉛化したものが
使用できるが、球状フェノール樹脂粒子を１０００℃以
上で焼成したもの（例えば、ユニチカ社製のユニベック
スとして入手できる。）が最も好ましい。本発明におい
ては、平均粒子径が１〜７０μｍの粒状グラッシーカー
ボンを使用することが好ましく、特に、平均粒子径が１
０〜５０μｍのものが好ましい。平均粒子径が１μｍ未
満のものでは、充分なＰＴＣの性質が得られず、また、
平均粒子径が７０μｍより大きいものではＰＴＣの性質
を示した後、常温に戻したとき初期の抵抗値に戻りにく
くなる。The ultrahigh molecular weight polyethylene used in the present invention is one having a molecular weight of 1,000,000 or more, particularly 1,000,000 or more, measured in a decalin solvent (135 ° C.).
It is preferably 100,000 or less. When the molecular weight is less than 1,000,000, the strength of the obtained composite is insufficient, and when it exceeds 6,000,000, molding may be difficult. As the ultra high molecular weight polyethylene used in the present invention, for example, those having an average particle diameter of 5 to 800 μm are used, and particularly 10 to 10
It is preferably 0 μm. If the average particle size is less than 5 μm, secondary aggregation is likely to occur, and if the average particle size exceeds 800 μm, it becomes difficult to obtain a composite having sufficient strength. The granular glassy carbon used in the present invention may be carbonized or graphitized from a thermosetting resin such as a furfuryl alcohol resin or a phenol resin as a raw material, but spherical phenol resin particles are fired at 1000 ° C. or higher. Most preferred are those available as Univex manufactured by Unitika Ltd. In the present invention, it is preferable to use granular glassy carbon having an average particle size of 1 to 70 μm, and particularly, an average particle size of 1
It is preferably from 0 to 50 μm. If the average particle size is less than 1 μm, sufficient PTC properties cannot be obtained, and
If the average particle size is larger than 70 μm, after exhibiting the properties of PTC, it becomes difficult to return to the initial resistance value when the temperature is returned to room temperature.
【０００７】これらの成分の配合により、室温（１０〜
３０℃）で約５Ω・ｃｍ以下の体積抵抗率を有し、１２
５〜１４０℃の温度範囲において抵抗の最大変化率が１
×１０5 以上のＰＴＣを有する導電性複合体が得られ
る。ここで、抵抗の最大変化率とは１２５〜１４０℃の
温度範囲における抵抗の最大値と最小値の比のことであ
る。By blending these components, room temperature (10 to 10
Has a volume resistivity of about 5 Ω · cm or less at 30 ° C., 12
Maximum rate of change of resistance is 1 in the temperature range of 5 to 140 ℃
A conductive composite having a PTC of × 10 5 or more is obtained. Here, the maximum rate of change in resistance is the ratio of the maximum value and the minimum value of resistance in the temperature range of 125 to 140 ° C.
【０００８】本発明の導電性複合体を製造するには、超
高分子量ポリエチレンと粒状グラッシーカーボンを所定
量混合した後、混合物を加熱下で圧縮成形することによ
り製造することができる。このとき、必要に応じて、離
型剤、酸化防止剤、炭酸カルシウム等の充填剤を添加し
てもよい。The electroconductive composite of the present invention can be produced by mixing a predetermined amount of ultrahigh molecular weight polyethylene and granular glassy carbon and then compression-molding the mixture under heating. At this time, if necessary, a release agent, an antioxidant, a filler such as calcium carbonate may be added.
【０００９】加熱下で圧縮成形するときの加熱温度とし
ては、１３０〜２００℃の範囲が好ましく、１４０〜１
９０℃の範囲がより好ましい。１３０℃より低い温度で
は、充分な強度が得られず、２００℃より高い温度で
は、超高分子量ポリエチレンが粒状グラッシーカーボン
の表面を覆うために充分な導電性が得られにくくなる。The heating temperature for compression molding under heating is preferably in the range of 130 to 200 ° C., and 140 to 1
The range of 90 ° C is more preferable. At a temperature lower than 130 ° C., sufficient strength cannot be obtained, and at a temperature higher than 200 ° C., it becomes difficult to obtain sufficient conductivity because the ultrahigh molecular weight polyethylene covers the surface of the granular glassy carbon.
【００１０】成形圧力としては、１０〜１５００Kg/cm2
が適当であり、好ましくは４０〜７００Kg/cm2である。
プレス時間としては、１０〜３６０秒が適当であり、好
ましくは２０〜３００秒である。プレス圧が１０Kg/cm2
より小さい場合や、プレス時間が１０秒より少ない場合
は、充分な強度が得られにくくなる。また、プレス圧が
１５００Kg/cm2を超える場合や、プレス時間が３６０秒
を超える場合は不経済であり、好ましくない。このよう
にして得られた導電性複合体は、より安定したＰＴＣを
得るために熱処理することが好ましい。熱処理の条件と
しては、８０〜２００℃、１０分〜２０時間が好まし
く、特に、１３０〜１８０℃、３０分〜５時間が好まし
い。８０℃及び１０分未満では、充分なＰＴＣの性質が
得られにくくなり、２００℃及び２０時間を超えると、
超高分子量ポリエチレンが劣下してしまい好ましくな
い。The molding pressure is 10 to 1500 Kg / cm 2.
Is suitable, and preferably 40 to 700 kg / cm 2 .
The pressing time is suitably 10 to 360 seconds, preferably 20 to 300 seconds. Pressing pressure is 10 kg / cm 2
If it is smaller or if the pressing time is less than 10 seconds, it becomes difficult to obtain sufficient strength. If the pressing pressure exceeds 1500 kg / cm 2 or the pressing time exceeds 360 seconds, it is uneconomical and not preferable. The conductive composite thus obtained is preferably heat-treated in order to obtain a more stable PTC. The conditions for the heat treatment are preferably 80 to 200 ° C. and 10 minutes to 20 hours, and particularly preferably 130 to 180 ° C. and 30 minutes to 5 hours. At 80 ° C and less than 10 minutes, it becomes difficult to obtain sufficient PTC properties, and at over 200 ° C and 20 hours,
Ultra high molecular weight polyethylene deteriorates, which is not preferable.
【００１１】[0011]
【実施例】次に、本発明を実施例によって具体的に説明
する。なお、実施例中の測定項目は次のようにして測定
した。EXAMPLES Next, the present invention will be specifically described with reference to examples. The measurement items in the examples were measured as follows.
【００１２】１）室温（２５℃）、８０℃での体積抵抗
率 Loresta AP MCP-T400 （三菱油化社製）により測定し
た。尚、測定に使用した導電性複合体のサイズは15mm
φ,1mm厚である。1) Volume resistivity at room temperature (25 ° C.) and 80 ° C. Measured with Loresta AP MCP-T400 (manufactured by Mitsubishi Petrochemical Co., Ltd.). The size of the conductive composite used for measurement is 15 mm.
φ, 1 mm thick.
【００１３】２）抵抗の最大変化率 加圧成形後の導電性複合体（15mmφ,1mm厚）に導電性ペ
ーストを塗布し、この複合体をオーブン中、１℃／分で
昇温していき、１２５〜１４０℃の温度範囲における抵
抗の最大値と最小値の比を求めた。2) Maximum rate of change in resistance A conductive paste (15 mmφ, 1 mm thick) after pressure molding was coated with a conductive paste, and this composite was heated in an oven at 1 ° C./min. , The ratio of the maximum value and the minimum value of the resistance in the temperature range of 125 to 140 ° C. was obtained.
【００１４】３）サイクルテスト 加圧成形後の導電性複合体（15mmφ,1mm厚）に導電性ペ
ーストを塗布し、１０Ｖで１５秒間保持し、電圧を印加
せずに３４５秒間保持し、これを１サイクルとして、１
０サイクル行った後、ペーストを剥し、室温（２５℃）
での体積抵抗率を測定し、サイクルテスト前の体積抵抗
率からの変化率を次式により算出した。 3) Cycle test A conductive paste (15 mmφ, 1 mm thick) after pressure molding was coated with a conductive paste, held at 10 V for 15 seconds, and held for 345 seconds without applying a voltage. 1 cycle
After 0 cycles, peel off the paste and leave at room temperature (25 ℃)
The volume resistivity was measured, and the rate of change from the volume resistivity before the cycle test was calculated by the following formula.
【００１５】４）耐電圧 耐電圧とは、ＰＴＣの性質を安定して維持できる限界の
電圧値のことであり、ＰＴＣの性質を示しているときに
は、理論的に次式が成立する。Ｐ＝ＶＩ＝一定 、両辺
の対数をとると ＬｏｇＶ＋ＬｏｇＩ＝Ｌｏｇｋ（ｋは定数）…………（１） ここでＰは電力、Ｖは電圧、Ｉは電流を表す。そこで、
加圧成形後の導電性複合体（15mmφ,1mm厚）に導電性ペ
ーストを塗布し、この複合体に電圧を徐々に印加してい
き、次式（２）の計算値が−０．８５以上になるときの
電圧値を耐電圧とした。 ここでＶ10は１０Ｖを、Ｉ10は１０Ｖでの電流値を、
Ｖ、Ｉはそれぞれ１０Ｖを超える電圧値とそのときの電
流値とを表す。4) Withstand Voltage Withstand voltage is the limit at which the properties of PTC can be stably maintained.
It is the voltage value, and when it shows the properties of PTC
In theory, the following equation holds. P = VI = constant, both sides
Log V + Log I = Logk (k is a constant) (1) where P is power, V is voltage, and I is current. Therefore,
The conductive composite (15 mmφ, 1 mm thickness) after pressure molding is applied to the conductive paste.
Applied and gradually apply voltage to the composite.
When the calculated value of the following equation (2) becomes -0.85 or more,
The voltage value was defined as the withstand voltage. Where VTenIs 10V, ITenIs the current value at 10V,
V and I are voltage values exceeding 10V and the voltage at that time, respectively.
And the flow value.
【００１６】実施例１ 分子量２００万の超高分子量ポリエチレン粉末（ミペロ
ン、三井石油化学社製）６０重量％と、１９００℃で焼
成された平均粒子径１５μｍの粒状グラッシーカーボン
（ユニチカ社製）４０重量％とをドライブレンドして混
合物を得た。この混合物を金型に充填し、金型温度１８
０℃、プレス圧４０kg/cm2で５分間プレスを行い、加圧
下で冷却して導電性複合体を得た。このようにして得ら
れた導電性複合体をさらに１５０℃で１時間熱処理し
て、室温での体積抵抗率が１．２×１０0 Ω・ｃｍであ
る導電性複合体を得た。Example 1 60% by weight of ultra high molecular weight polyethylene powder having a molecular weight of 2,000,000 (Miperon, manufactured by Mitsui Petrochemical Co., Ltd.) and 40% by weight of granular glassy carbon (manufactured by Unitika Co., Ltd.) having an average particle diameter of 15 μm and calcined at 1900 ° C. % Was dry blended to obtain a mixture. This mixture was filled in a mold and the mold temperature was adjusted to 18
Pressing was carried out at 0 ° C. and a pressing pressure of 40 kg / cm 2 for 5 minutes, followed by cooling under pressure to obtain a conductive composite. The conductive composite thus obtained was further heat-treated at 150 ° C. for 1 hour to obtain a conductive composite having a volume resistivity of 1.2 × 10 0 Ω · cm at room temperature.
【００１７】この導電性複合体に導電性ペーストを塗布
し、以下の実験を行った。この導電性複合体をオーブン
中に保持し、１℃／分で昇温していき、抵抗値を測定し
ていくと１２５℃付近から抵抗が大きく上昇し始め、１
３５℃で最大の抵抗を示した。この結果から、この複合
体の１２５〜１４０℃の温度範囲において、抵抗の最大
変化率を算出すると、３．５×１０6 であった。また、
ＰＴＣの性質を発現させた後、常温（２５℃）に戻した
ときに体積抵抗率が初期の値に戻っているかどうかを調
べるために、サイクルテストを行った結果、サイクルテ
スト前に対する体積抵抗率の変化率は３．０％と安定し
ていた。また、ＰＴＣの性質を安定して維持できる限界
の電圧値を耐電圧として試験をしてみたところ、この導
電性複合体の耐電圧は７０Ｖであった。抵抗の最大変化
率とサイクルテストの結果及び耐電圧を表１に示す。A conductive paste was applied to this conductive composite, and the following experiment was conducted. When this conductive composite was held in an oven and heated at a rate of 1 ° C./minute, and the resistance value was measured, the resistance began to increase greatly at around 125 ° C.
Maximum resistance was exhibited at 35 ° C. From this result, the maximum change rate of resistance in the temperature range of 125 to 140 ° C. of this composite was calculated to be 3.5 × 10 6 . Also,
After expressing the properties of PTC, a cycle test was conducted to check whether the volume resistivity returned to the initial value when the temperature was returned to room temperature (25 ° C). The rate of change was stable at 3.0%. Further, when a test was conducted using a withstand voltage as a limit voltage value capable of stably maintaining the properties of PTC, the withstand voltage of this conductive composite was 70V. Table 1 shows the maximum rate of change in resistance, the result of the cycle test, and the withstand voltage.
【００１８】実施例２ 分子量２００万の超高分子量ポリエチレン粉末（ミペロ
ン、三井石油化学社製）４７．５重量％と、１０００℃
で焼成された平均粒子径１５μｍの粒状グラッシーカー
ボン（ユニチカ社製）５２．５重量％とをドライブレン
ドして混合物を得た。この混合物を金型に充填し、金型
温度１８０℃、プレス圧４０kg/cm2で５分間プレスを行
い、加圧下で冷却して導電性複合体を得た。このように
して得られた導電性複合体をさらに１５０℃で１時間熱
処理して、室温（２５℃）での体積抵抗率が１．８×１
０0 Ω・ｃｍである導電性複合体を得た。このようにし
て得た導電性複合体を実施例１と同様にして１２５〜１
４０℃の温度範囲における抵抗の最大変化率とサイクル
テスト及び耐電圧を測定した結果を表１に示す。Example 2 47.5% by weight of ultra-high molecular weight polyethylene powder having a molecular weight of 2,000,000 (Miperon, manufactured by Mitsui Petrochemical Co., Ltd.) and 1000 ° C.
The mixture was obtained by dry blending with 52.5% by weight of granular glassy carbon (manufactured by Unitika Ltd.) having an average particle diameter of 15 μm, which was calcined in. This mixture was filled in a mold, pressed at a mold temperature of 180 ° C. and a pressing pressure of 40 kg / cm 2 for 5 minutes, and cooled under pressure to obtain a conductive composite. The conductive composite thus obtained was further heat-treated at 150 ° C. for 1 hour so that the volume resistivity at room temperature (25 ° C.) was 1.8 × 1.
A conductive composite having a resistance of 0 0 Ω · cm was obtained. The conductive composite thus obtained was treated in the same manner as in Example 1 to obtain 125-1.
Table 1 shows the results of measurement of the maximum resistance change rate, the cycle test, and the withstand voltage in the temperature range of 40 ° C.
【００１９】実施例３ 分子量２００万の超高分子量ポリエチレン粉末（ミペロ
ン、三井石油化学社製）４７．５重量％と、１０００℃
で焼成された平均粒子径２０μｍの粒状グラッシーカー
ボン（ユニチカ社製）５２．５重量％とをドライブレン
ドして混合物を得た。この混合物を金型に充填し、金型
温度１８０℃、プレス圧４０kg/cm2で５分間プレスを行
い、加圧下で冷却して導電性複合体を得た。このように
して得られた導電性複合体をさらに１５０℃で１時間熱
処理して、室温（２５℃）での体積抵抗率が３．５×１
０0 Ω・ｃｍである導電性複合体を得た。このようにし
て得た導電性複合体を実施例１と同様にして１２５〜１
４０℃の温度範囲における抵抗の最大変化率とサイクル
テスト及び耐電圧を測定した結果を表１に示す。Example 3 Ultra-high molecular weight polyethylene powder having a molecular weight of 2,000,000 (Miperon, manufactured by Mitsui Petrochemical Co., Ltd.) 47.5% by weight and 1000 ° C.
A mixture was obtained by dry blending with 52.5% by weight of granular glassy carbon (manufactured by Unitika Ltd.) having an average particle diameter of 20 μm, which was fired at. This mixture was filled in a mold, pressed at a mold temperature of 180 ° C. and a pressing pressure of 40 kg / cm 2 for 5 minutes, and cooled under pressure to obtain a conductive composite. The conductive composite thus obtained was further heat-treated at 150 ° C. for 1 hour so that the volume resistivity at room temperature (25 ° C.) was 3.5 × 1.
A conductive composite having a resistance of 0 0 Ω · cm was obtained. The conductive composite thus obtained was treated in the same manner as in Example 1 to obtain 125-1.
Table 1 shows the results of measurement of the maximum resistance change rate, the cycle test, and the withstand voltage in the temperature range of 40 ° C.
【００２０】実施例４ 分子量２００万の超高分子量ポリエチレン粉末（ミペロ
ン、三井石油化学社製）５５重量％と、１９００℃で焼
成された平均粒子径２０μｍの粒状グラッシーカーボン
（ユニチカ社製）４５重量％とをドライブレンドして混
合物を得た。この混合物を金型に充填し、金型温度１８
０℃、プレス圧４０kg/cm2で５分間プレスを行い、加圧
下で冷却して導電性複合体を得た。このようにして得ら
れた導電性複合体をさらに１５０℃で１時間熱処理し
て、室温（２５℃）での体積抵抗率が４．４×１０0 Ω
・ｃｍである導電性複合体を得た。このようにして得た
導電性複合体を実施例１と同様にして１２５〜１４０℃
の温度範囲における抵抗の最大変化率とサイクルテスト
及び耐電圧を測定した結果を表１に示す。Example 4 55% by weight of ultra-high molecular weight polyethylene powder having a molecular weight of 2,000,000 (Miperon, manufactured by Mitsui Petrochemical Co., Ltd.) and 45% by weight of granular glassy carbon (manufactured by Unitika Co., Ltd.) having an average particle diameter of 20 μm and calcined at 1900 ° C. % Was dry blended to obtain a mixture. This mixture was filled in a mold and the mold temperature was adjusted to 18
Pressing was carried out at 0 ° C. and a pressing pressure of 40 kg / cm 2 for 5 minutes, followed by cooling under pressure to obtain a conductive composite. The conductive composite thus obtained was further heat-treated at 150 ° C. for 1 hour to have a volume resistivity of 4.4 × 10 0 Ω at room temperature (25 ° C.).
A conductive composite of cm was obtained. The conductive composite thus obtained was treated in the same manner as in Example 1 at 125 to 140 ° C.
Table 1 shows the results obtained by measuring the maximum rate of change in resistance, the cycle test, and the withstand voltage in the temperature range.
【００２１】比較例１ 分子量１００万の超高分子量ポリエチレン粉末（PE-COM
P-1407、東洋インキ社製）７０重量％と、１９００℃で
焼成された平均粒子径２０μｍの粒状グラッシーカーボ
ン（ユニチカ社製）３０重量％とをドライブレンドして
混合物を得た。この混合物を金型に充填し金型温度１４
５℃、プレス圧１５０Kg/cm2で１０秒間プレスを行い加
圧下で冷却することにより、室温での体積抵抗が１．３
×１０0Ω・ｃｍである導電性複合体を得た。このよう
にして得た導電性複合体を実施例１と同様にして１２５
〜１４０℃の温度範囲における抵抗の最大変化率とサイ
クルテスト及び耐電圧を測定した結果を表１に示す。Comparative Example 1 Ultrahigh molecular weight polyethylene powder having a molecular weight of 1,000,000 (PE-COM
70% by weight of P-1407 (manufactured by Toyo Ink Co., Ltd.) and 30% by weight of granular glassy carbon (manufactured by Unitika Co., Ltd.) having an average particle diameter of 20 μm, which was fired at 1900 ° C., were dry blended to obtain a mixture. This mixture was filled in a mold and the mold temperature was adjusted to 14
By pressing at 5 ° C and a pressing pressure of 150 kg / cm 2 for 10 seconds and cooling under pressure, the volume resistance at room temperature becomes 1.3.
A conductive composite having a density of × 10 0 Ω · cm was obtained. The conductive composite thus obtained was treated with 125
Table 1 shows the results of measuring the maximum rate of change in resistance, the cycle test, and the withstand voltage in the temperature range of up to 140 ° C.
【００２２】比較例２ 分子量１００万の超高分子量ポリエチレン粉末（PE-COM
P-1407、東洋インキ社製）７０重量％及びカーボンブラ
ック（ケッチェンブラック ＥＣ、ライオン社製）３０
重量％に代えた以外は、実施例１と同様に処理し、室温
での体積抵抗率が２．４×１０0 Ω・ｃｍである導電性
複合体を得た。このようにして得た導電性複合体を実施
例１と同様にして１２５〜１４０℃の温度範囲における
抵抗の最大変化率とサイクルテスト及び耐電圧を測定し
た結果を表１に示す。Comparative Example 2 Ultrahigh molecular weight polyethylene powder having a molecular weight of 1,000,000 (PE-COM
P-1407, manufactured by Toyo Ink) 70% by weight and carbon black (Ketjen Black EC, manufactured by Lion) 30
The procedure of Example 1 was repeated except that the content was changed to wt% to obtain a conductive composite having a volume resistivity at room temperature of 2.4 × 10 0 Ω · cm. Table 1 shows the results of measuring the maximum rate of change in resistance, the cycle test, and the withstand voltage of the conductive composite thus obtained in the same manner as in Example 1 in the temperature range of 125 to 140 ° C.
【００２３】[0023]
【表１】 [Table 1]
【００２４】表１から、実施例１〜４は、比較例１〜２
と比べて室温での体積抵抗率と８０℃での体積抵抗率と
がほとんど変化していないので、周囲の温度を受けにく
いことが明らかである。From Table 1, Examples 1 to 4 are Comparative Examples 1 to 2.
Compared with the above, since the volume resistivity at room temperature and the volume resistivity at 80 ° C. hardly change, it is clear that it is difficult to receive the ambient temperature.
【００２５】[0025]
【発明の効果】本発明の導電性複合体は、耐電圧に優
れ、１２５〜１４０℃という極めて狭い温度範囲におい
て抵抗の最大変化率が極めて大きいＰＴＣを有している
ので、周囲の温度を受けにくく、電気デバイスのヒュー
ズ、面状発熱体等に最適に用いられる。INDUSTRIAL APPLICABILITY The conductive composite of the present invention has a high withstand voltage and has a PTC having an extremely large maximum rate of change of resistance in an extremely narrow temperature range of 125 to 140 ° C. It is difficult to use and is optimally used for fuses of electric devices and sheet heating elements.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 岩屋 嘉昭 京都府宇治市宇治小桜23番地 ユニチカ株 式会社中央研究所内 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Yoshiaki Iwaya 23 Uji Kozakura, Uji City, Kyoto Prefecture Unitika Ltd. Central Research Laboratory
Claims (1)
ーカーボンとからなり、１２５〜１４０℃の温度範囲に
おいて抵抗の最大変化率が１×１０5 以上の正特性温度
係数を有することを特徴とする導電性複合体。1. A conductive material comprising ultra-high molecular weight polyethylene and granular glassy carbon and having a positive temperature coefficient of 1 × 10 5 or more in a maximum resistance change rate in a temperature range of 125 to 140 ° C. Complex.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26196893A JPH0794018A (en) | 1993-09-24 | 1993-09-24 | Conductive compound |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26196893A JPH0794018A (en) | 1993-09-24 | 1993-09-24 | Conductive compound |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0794018A true JPH0794018A (en) | 1995-04-07 |
Family
ID=17369162
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP26196893A Pending JPH0794018A (en) | 1993-09-24 | 1993-09-24 | Conductive compound |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0794018A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0730282A3 (en) * | 1995-02-28 | 1997-06-04 | Unitika Ltd | PTC element and process for producing the same |
| JP2008138134A (en) * | 2006-12-05 | 2008-06-19 | Sakushin Kogyo Kk | Semiconductive ultra-high-molecular-weight polyethylene composition, film composed thereof and its manufacturing method |
| US8623801B2 (en) | 2008-09-30 | 2014-01-07 | Ntn Corporation | Electrically conductive polyethylene resin composition, electrically conductive polyethylene resin molding sliding bearing, and sliding sheet |
-
1993
- 1993-09-24 JP JP26196893A patent/JPH0794018A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0730282A3 (en) * | 1995-02-28 | 1997-06-04 | Unitika Ltd | PTC element and process for producing the same |
| JP2008138134A (en) * | 2006-12-05 | 2008-06-19 | Sakushin Kogyo Kk | Semiconductive ultra-high-molecular-weight polyethylene composition, film composed thereof and its manufacturing method |
| US8623801B2 (en) | 2008-09-30 | 2014-01-07 | Ntn Corporation | Electrically conductive polyethylene resin composition, electrically conductive polyethylene resin molding sliding bearing, and sliding sheet |
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