JPS63221601A - Polymer positive temperature characteristics resistor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a polymer positive temperature characteristic resistor, and more specifically, the present invention relates to a polymer positive temperature characteristic resistor. Polymer with temperature characteristics!
The present invention relates to a polymeric positive temperature characteristic resistor which is a resistor using a polymer compound, generates heat at a low temperature, and can be used, for example, as a low-temperature heating element, a temperature fuse, an overcurrent fuse, etc.

[Prior art and its problems] Materials with positive temperature characteristics have conventionally been made by blending an inorganic material such as barium titanate or a crystalline polymer with conductive particles such as carbon black powder. Compositions are known.

Such compositions include, for example, polyethylene mixed with carbon black powder and ethylene-
It has been proposed that carbon black powder is blended with vinyl acetate resonance combination (JP-A-55-78408, JP-A-58-839, JP-A-59-122524, JP-A-61-250058). number, etc.).

However, when these compositions are used as heating elements, the exothermic temperature is, for example, about 100°C when using low density polyethylene, and about 70°C when using ethylene-vinyl acetate copolymer. Since the temperature is relatively high at 0.degree. C., there is a problem in that conventional polymer positive temperature heating elements cannot be used in fields where heat generation at lower temperatures is required.

In addition, from the perspective of positive temperature characteristics, in a temperature range exceeding the temperature range that causes a rapid increase in resistance I1, conventional polymer positive temperature characteristics compositions exhibit a phenomenon in which the resistance value rapidly decreases. There was a safety problem when it overheated.

[Object of the Invention] An object of the present invention is to solve the above-mentioned problems and to provide a polymer positive temperature characteristic resistor that exhibits positive temperature characteristics at a lower temperature than conventionally proposed compositions. be.

[Means for achieving the above object] In order to achieve the above object, as a result of extensive research by this inventor, a composition containing a specific crystalline polymer and conductive particles in a specific ratio was developed. This invention was based on the discovery that a material exhibits positive temperature characteristics at relatively low temperatures, and that the resistance value does not decrease even in a high temperature range exceeding the temperature range where the resistance value increases due to the positive temperature characteristics. reached.

That is, the outline of the first invention is: A polymer positive temperature characteristic resistor comprising a composition of 10 to 80% by weight of trans-1,4-polyisoprene and 20 to 90% by weight of conductive particles.

The outline of the second invention is as follows.

A composition containing 10 to 80% of tri-7s-1,4-polyisoprene and 20 to 90% of conductive particles contained 10 to 300 parts by weight of semiconductive particles per 100 parts by weight. This is a polymer positive temperature characteristic resistor made of a composition.

As the trans-1,4-polyinprene, one with a heavy number may be used, but for example, an extraction method of extracting from a C5 fraction, a precision distillation method, a method of extracting 2-methyl-2-pentene at a high temperature in the presence of a catalyst, etc. Propylene z-quantification method to decompose, inamicin dehydrogenation method to dehydrogenate isobutylene, 4 obtained by pressurizing isobutylene and formalin in the presence of sulfuric acid,
4'-Dimethyl-1,3-metadioxane is decomposed using the tyrene-formalin method, in which 2-methyl-1-butyn-3-ol obtained by reacting acetone and acetylene in ammonia is hydrogenated. 2-methyl-1-butene-
It is also possible to use a monomer obtained by polymerizing a monomer obtained by a method such as the 7cetone-acetylene method in which 3-ol is dehydrated in the presence of a catalyst such as alkyllithium.

Examples of the conductive particles include carbon black such as furnace black, thermal black and acetylene black; graphite powder; iron, aluminum,
Examples include metal powders such as nickel, zinc, and copper; pulverized carbon fibers such as PAN and pitch; and pulverized metal fibers.

These may be used alone or in combination of two or more.

Among these, carbon black, graphite powder and mixtures thereof are particularly preferred.

The average particle size of the conductive particles other than the carbon black is usually 0.01 to 10 Gpm.

Preferably it is 0.1 to 50 ILm, and for carbon black it is usually 10 to 200 m#L, preferably 15 to 100 m#L.

When the average particle diameter of the conductive particles is less than 0.01 m (10 mμ for carbon black).

The resulting polymer positive temperature resistor may not have a sufficient resistance increase factor in a specific temperature range, resulting in decreased sensitivity.

On the other hand, when the average particle size exceeds 200m#L (for 10100p carbon black), the electrical resistance value of the resulting polymeric positive temperature resistor at room temperature increases, and the amount of heat generated when used as a heating element increases. This is not desirable because it becomes smaller.

As the semiconductive particles, for example, silico y(!3+
), germanium (Ge), silicon carbide (SiG), boron carbide (e.g. BsC), lithium nitride (1;
3N), β-alumina (β-A1203), tin oxide (SJIO), gallium oxide (CaSb),
Gallium phosphide (GaP), gallium arsenide (GaS)
b), indium antimony (IuSb), indium selenium (InSe), gallium φ selenium (GaS
e), particles of indium tellurium (InTe), gallium tellurium (GaTe), and the like.

These semiconductive particles may be used alone, or
Two or more types may be used in combination.

Among these, silicon carbide J (SiC), borocarbide J
(e.g. BsC), lithium nitride (Li3N), β
- Alumina (β-A h 03 ) and mixtures thereof are preferred, particularly silicon carbide (SiC).

The average particle size of the semiconductive particles is usually 300 gm or less, preferably 100 gm or less.

If the average particle diameter of the conductive film exceeds 3001 Lmt-, the effect of improving voltage resistance and heat generation uniformity will be reduced.

In the first invention, the trans-1,4-polyisoprene and the conductive particles are blended in a specific ratio, and then kneaded and used.

The blending ratio of the trans-1,4-polyisoprene and the conductive membrane is 10 to 80% by weight of the trans-1,4-polyisoprene and 20 to 80% by weight of the conductive particles. In particular, when carbon black is used as the conductive particles, it is preferably 25 to 60% by weight.

When the blending ratio of the conductive particles is less than 20% by weight, sufficient conductivity may not be obtained.

On the other hand, if the blending ratio of the conductive particles exceeds 80% by weight, sufficient positive temperature characteristics may not be exhibited, and blending and kneading of the conductive particles may become difficult.

: In issue 11 of iS2, IIi of the first invention
Jingji semiconductive particles are blended in a specific ratio to the composition 100@Q part.

The blending ratio of the semiconductive particles is 10 to 300 parts by weight based on 100 parts by weight of the composition of the first invention.

If the blending ratio of the semiconductive particles is less than 1 part, the resulting polymeric positive temperature characteristic resistor may not have sufficient uniformity in withstand voltage or heat generation temperature distribution. On the other hand, if the blending ratio of the semiconductive particles exceeds 300 parts by weight, blending and kneading of the semiconductive particles may become difficult. The mixing in the first invention and the second invention can be carried out using a common resin kneading machine, such as a panburi mixer, mixing roll, or center screw extruder.

In the above-mentioned kneading, a commonly used crosslinking agent such as dicumyl peroxide can also be blended.

In addition, if necessary, after forming the mixed material, zm due to radiation
may be done.

The polymer positive temperature characteristic resistor of the present invention generates heat in a lower temperature range compared to conventional polymer positive temperature characteristic resistors.
It can be suitably used for low-temperature heating elements, temperature fuses, overcurrent fuses, etc., for which polymer positive temperature characteristic resistors could not be used conventionally.

[4 Effects of IJT] According to this invention, (1) Positive temperature characteristics are exhibited in a lower temperature range compared to conventional polymer positive temperature characteristics resistors.

(2) After the electrical resistance rises steeply in a specific temperature range, it shows a stable electrical resistance and has a high withstand voltage; (3) It has low adhesiveness and is easy to handle, etc. A polymer positive temperature characteristic resistor having various effects can be provided.

[Example 1 Next, examples and comparative examples of this 911JJ will be shown.

This invention will be explained in more detail.

(Example 1) 80 parts by weight of trans-1,4-polyisoprene [manufactured by Cutelisoprene Chemical Lu, trade name: "DingP3QIJl] and carbon black [average particle size 43 m4, made by Mitsubishi Chemical Corporation, trade name: " Dia black EJ] 40 heavy fi
1 part and fed to a Rabogutist mill.

IIfI crosstalk was carried out for 20 minutes at a temperature of 120°C.

Next, the obtained composition is formed into a sheet.

Furthermore, electrolytic nickel foil with a wall thickness of 20 gm was pressed onto both the front and back surfaces of the film and press-molded to obtain a Me receipt with a wall thickness of Inn.

A 1 cm square section was cut from this laminated sheet, and the change in resistance value due to temperature was measured.

The measurement results are shown in 1A.

From this result, the specific resistance of the obtained composition at room temperature was 25.8 Ω·cm, which was 70% of the resistance value at room temperature.
The ratio of resistance f^ at °C (resistance increase magnification) is 194.5
It was confirmed that this resistance increase factor was maintained even when the temperature exceeded 100°C. Moreover, the composition obtained by cross-wiring had no stickiness and was easy to handle.

(Comparative Example 1) The same procedure as described above was carried out in Example 1 except that ethylene-vinyl acetate copolymer [manufactured by Toyo Sakuda Kogyo ■, trade name: ruE834J] was used instead of trans-1,4-polyisoprene. The change in resistance value due to temperature was measured in the same manner as in Example 1.

The results are shown in Figure 1.

From this result, the specific resistance of the obtained composition at room temperature is 88 Ω・cm, and the resistance increase factor shows a maximum value of 103.5 at 80°C, and the resistance value tends to decrease as the temperature further increases by 11. I confirmed that there is.

In addition, this composition had high adhesiveness and was not easy to handle during processing into a sheet.

(Example 2) Carbonized Ke-f raw powder [manufactured by Fujimi Togyo Co., Ltd.] was added to 100 parts by weight of a composition consisting of 84 parts of trans-1,4-polyisoprene and 36 parts of carbon black. Product name;
rsic #20QOJ] and kneaded for 20 minutes at a temperature of 120° C. using a Labo Plastomill to obtain a composition.

A test piece was prepared using this composition in the same manner as in Example 1, and the change in resistance value due to temperature was measured.

The results are shown in Figure 2.

From this result, the specific resistance of this composition at room temperature is 62
．． 6Ω・cm, and the resistance increase factor at 70°C is l
It was confirmed that it was Q4.3.

Next, a voltage was momentarily applied to this test piece at room temperature to measure the voltage at which breakdown occurred (dynamic withstand voltage), and the dynamic withstand voltage was 125 V.

moreover,! When we cut a 4cm square test piece from the 11-layer sheet and applied a DC 30V voltage to its front and back surfaces to examine its heat generation characteristics, the surface temperature was 53°C, and the temperature distribution difference was extremely narrow, within 5°C. Met.

(Comparative example 2) In place of the composition used in Example 2 above.

Except that a composition was used in which 87 parts by weight of silicon carbide powder was blended with 100 parts by weight of a mixture of ethylene-vinyl acetate copolymer and carbon black in which the proportion of carbon black was 42@31%. In the same manner as in Example 2, the change in resistance value of the composition due to temperature was measured.

The results are shown in Figure 2.

From this result, the specific resistance of this composition at room temperature is 43
．． 8Ω·cm, and the resistance increase factor at 80°C was lQ3.2, confirming that the resistance value decreases when the temperature exceeds 80°C.

Next, when we applied a voltage instantaneously to this test piece at room temperature and measured the voltage that would lead to breakdown (dynamic withstand voltage), the dynamic withstand voltage was as low as 50y, indicating that there was insufficient margin for safety. It was something.

Furthermore, a 4 cm square test piece was cut from the Ja layer receipt, and a voltage of 30 V DC was applied to the front and back surfaces of the test piece to investigate the heat generation characteristics.The surface temperature was 70°C, and the resistor of Example 2 The temperature was considerably higher than that of

(Comparative example 3) In place of the composition used in Example 2 above.

Low-density polyethylene with a carbon black content of 76% by weight [manufactured by Toyo Sakudatsu Co., Ltd., product name: "Petrocene 1"]
Same as Example 2, except that 43 parts by weight of silicon carbide powder was mixed with 100 parts by weight of the mixture of "70"] and carbon black, and kneaded for 20 minutes at a temperature of 150°C using a Laboplast Mill. The change in resistance value due to temperature of the composition was measured.

The results are shown in Figure 2.

From this result, the specific resistance of this composition at room temperature is 44
．． 2Ω·cm, and the resistance increase factor at 107°C was 1043, confirming that the resistance value decreased when the temperature exceeded 107°C.

Further, the dynamic withstand voltage was a low value of 50V.

Further, a 4 cm square test piece was cut out from the line layer sheet, and a voltage of 30 V DC was applied to the front and back surfaces of the test piece to examine its heat generation characteristics, and the surface temperature was as high as 104°C.

(Example 3) A mixture of trans-1,4-polyinprene and carbon black with a carbon black blending ratio of 40 @ fi%! 0.00 tons of silicon carbide powder was mixed with 43 tons of silicon carbide powder, and the mixture was heated at 150°C using a laboplast mill.
The mixture was kneaded for 0 minutes.

Next, 0.13 parts by weight of dicumyl peroxide as a crosslinking agent was added to this kneaded product, and the mixture was further kneaded for 3 minutes.

? The obtained composition was evaluated in the same manner as in Example 2 above.

Figure 3 shows the change in resistance value due to temperature.

From this result, the specific resistance at room temperature is 50.2Ω・cm
The resistance increase factor at 80° C. was 103.8.

Further, the dynamic withstand voltage was 150 V, and the 9i ripening temperature distribution was also extremely narrow, similar to Example 2.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the relationship between specific resistance and temperature for a polymer positive temperature characteristic resistor which is an example of the development fjl of ii and an example of a conventional polymer positive temperature characteristic resistor; FIG. 2 shows the relationship between specific resistance and temperature for a polymer positive temperature characteristic resistor which is an example of the second IJ+, another example of a conventional polymer positive temperature characteristic resistor, and still another example. FIG. 3 is an explanatory diagram showing the relationship between specific resistance and temperature for a polymer positive temperature characteristic resistor which is another embodiment of the second invention. 4:゛・r Figure 1 Figure 2 Figure 3 Temperature ('C)

Claims (2)

[Claims] (1) A polymer positive temperature characteristic resistor comprising a composition of 10 to 80% by weight of trans-1,4-polyisoprene and 20 to 90% by weight of conductive particles. (2) A composition containing 10 to 300 parts by weight of semiconductive particles per 100 parts by weight of a composition of 10 to 80% by weight of trans-1,4-polyisoprene and 20 to 90% by weight of conductive particles. Polymer positive temperature characteristic resistor consisting of.