JPS60135441A - Semiconducting resin composition - Google Patents

Abstract

PURPOSE:To produce easily the titled composition having an electrical resistivity of 10<3>-10<6>OMEGA.cm, by incorporating a conductive carbon black in combination with a thermal carbon black having a larger particle size into an ethylenic polymer. CONSTITUTION:100pts.wt. ethylenic polymer (e.g. polyethylene or an ethylene- vinyl acetate copolymer), a conductive carbon black (preferably acetylene black or furnace black) in a prescribed amount, and about 5-20pts.wt. thermal carbon black (e.g. MI carbon) are kneaded in a Banbury mixer, etc. to give a semiconducting resin composition with a required resistivity.

Description

DETAILED DESCRIPTION OF THE INVENTION 1. Background and Objectives of the Invention The present invention relates to a semiconductive resin composition, and particularly to a semiconductive resin composition that has an electrical resistance of 1.
The present invention relates to a semi-S conductive resin composition suitable for achieving a resistance of 03 to 106 Ω/ax.

Conventionally, semiconductive resin compositions have been made using polyolefins such as polyethylene, ethylene vinyl acetate copolymers,
J-ethylene blue acrylate or ethylene-propylene rubber filled with conductive and electrically conductive carbon black has been used.

In this case, those with electrical resistance of 1030/cm or more,
The electrical resistance decreases as the amount of carbon black filled increases, so it can be obtained by controlling the amount of carbon black packed. Also, the electrical resistance is 10”Ω/CI
Those of n or more can be easily obtained by using carbon black and an inorganic filler in combination.

However, it is difficult to adjust the resistance value of fLNJII electrical resistance of 103 to 10 lIΩ/cm, and increasing or decreasing the amount of carbon black filled causes a large change in electrical resistance, and it is difficult to obtain the desired electrical resistance. It wasn't easy. Even a slight change in the crosstalk conditions causes large variations in electrical resistance, making it difficult to obtain a desired electrical resistance.

The present invention has been made in view of the above, and its purpose is to provide a semiconductive resin composition that can easily have any electrical resistance within the range of 103-106 Ω/cm. There are 4 things to offer.

[Summary of the Invention] Kikomei is characterized by a composition in which conductive carbon black and thermal carbon black, which has a larger particle size than the conductive carbon black, are added to a 1-tyrene polymer.

One way to add conductive carbon black to ethylene polymer is to knead it using a panburi mixer or roll kneader, but the electrical resistance changes easily depending on the cross-wire conditions, making it difficult to obtain a stable value. There's a problem. It is said that this is because the connections (straftures) of carbon particles are cut.

Therefore, in the present invention, in order to solve the above-mentioned problems, a large particle diameter 4
By adding a normal carbon blank, it was possible to reduce the decrease in conductivity. In addition, by using 4 Jl of conductive carbon black and thermal carbon black, the flow during extrusion molding becomes uniform, resulting in uniform dispersion of carbon black, which has the advantage of reducing variations in electrical resistance.

The conductive carbon black Toji C used here may be acetylene black or furnace black. Ketjen black EC is not suitable because the electric 41U resistance becomes too small due to the tunnel effect and jump effect of carbon particles.

L Example J Next, specific examples and comparative examples will be explained.

Table 1 shows examples and comparative examples. By the way, the fabrication of a module cable for measuring volume resistance and the measurement of volume resistance were carried out as follows. Knead the compounds of each composition using a Pan Bali mixer,
Pass the extruder through an extrusion bell with a diameter of 1 mm and a width of 35 m.
Next, this was wrapped 10 times along the length of the noflumi pipe with 1/3 razo wrapping of polyethylene tape containing a cross-linking agent, and the insulation thickness was 5 times.
It was made into a gel cable in mm. Then this [7
The vapor pressure of the kaesol is 13! /ci high pressure cooker for 10 minutes, cut out the terminal, wrapped lead wires around both ends, and fixed with conductive paint to eliminate contact resistance. To measure the volume resistance, measure the resistance value with a Wheatstone bridge and convert it to volume resistance (Ω/cm).

The first time of kneading the kneading strip A'1 using the Pan Bali mixer was at a maximum temperature of 130-140''C for 1 hour and 4 minutes, and the second and third kneading times were at a maximum temperature of 120-130°C and a time of 2 minutes.

In Table 1, the base polymer is ethylene vinyl acetate copolymer (vinyl acetate 12%, MI = 2) 70% by weight.
Medium-density polyethylene (density 0.934, MI
= 2) was used as a 3% blend. Furthermore, FEF (Attitude #100) was used as the furnace black.

FIG. 1 is a diagram showing the relationship between the number of times of kneading using the Pan Bali mixer and volume resistance for each of the Examples and Comparative Examples shown in Table 1. An example in which conductive carbon black and Ml carbon (thermal carbon black) were filled into the base polymer consisting of J, uni, ethylene vinyl acetate polymer and poly 1'J shown in Table 1 and Figure 1. For Nos. 1 to 4, even if the number of times of kneading by Panhari Miki 1 No was increased from 1 to 3, there was little change in volume resistivity and a stable value was obtained. This is because even if the roughtures are cut into the conductive carbon black slivers by kneading, the change in electrical resistance is reduced due to the positive effect of the M l-carbon black having a large particle size.

On the other hand, in the case of Comparative Examples 1 to 3 in which only conductive carbon black without M1 carbon was added, the number of kneading was 1.
As the number of times increases from 3 times to 3 times, the volume resistance increases significantly and becomes more than 10 times that in the above case. , Furthermore, M
When the amount of T carbon added is 5% by weight or more, a remarkable effect appears, and when it is 20% by weight or more, the effect is almost lυ
Nothing changed. Therefore, it is desirable that the amount of M1 carbon added is 5 to 20% by weight.

In addition to the above-mentioned examples, Pace Polymer Binding C also includes low-density polyJ-tyrene, high-density polyJ-dylene, dylene-vinyl acetate co-Φ combination, ]0 tyremp[' pyrene rubber alone; -C is also good.

U Effect of the invention 1 As explained above, according to the present invention, the electrical resistance is 10
J3 is in the range of 3 to 106 Ω/cm (fFf<6), which is effective.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the experimental results of the relationship between the number of times of kneading with a panburi mixer and the volume resistance of a semiconductive resin composition.

Claims (1)

[Claims] (1) A semiconductive resin composition characterized in that it is formed by adding conductive carbon black and thermal carbon black having a larger particle size than the conductive carbon black to an ethylene-based polymer. (2) The semiconductive resin composition according to claim 1, wherein the amount of the thermal carbon black added is 5% to 20% by weight based on 7100% by weight of the ethylene-based poly.