JPS6090235A - Electrically conductive chloroprene rubber composition - Google Patents

Abstract

PURPOSE:An electrically conductive chloroprene rubber composition obtained by adding a specific compound to chloroprene rubber without causing variation in volume resistivity by kneading conditions or external force, etc. in incorporating carbon black therewith. CONSTITUTION:An electrically conductive chloroprene rubber composition obtained by adding (B) 2-20pts.wt. ''Ketjenblack EC'', e.g. manufactured by AKZO N.V. in the Netherlands or Lion Corporation, and (C) 10-70pts.wt. electrically nonconductive carbon black having >=11mmu average particle diameter, e.g. furnace black or thermal black to (A) 100pts.wt. chloroprene rubber. The resultant composition is used for electrically conductive molded articles, e.g. packagings or vibration-damping materials in addition to uses for inner layer sheath of explosion-proof cabtyre cables to exhibit improved practical effect with constant volume resistivity.

Description

Detailed Description of the Invention [Backbone and Object of the Invention] The present invention relates to an IX electrically conductive chloroprene rubber composition, and more particularly, to an electrically conductive chloroprene rubber composition used for sheathing the inner layer of a chloroprene-sheathed explosion-proof cabtyre cable. It is related to things.

Conventionally, conductive chloroprene rubber is obtained by blending a large amount of 1j conductive material such as metal powder, graphite powder, conductive carbon black, or electrolyte into chloroprene rubber.

Among these conductive substances, carbon black having a high degree of conductivity, such as acetylene black, is mainly used industrially from the viewpoint of characteristics and economy.
It is manufactured by blending 11 parts of 0ff with 30 parts or more of drying, and adding a vulcanizing agent, an anti-aging agent, a softening agent, etc. as necessary. However, these conductive chloroprene rubbers have a resistance of 10Ω
- A product with a volume resistivity as high as 100% can be obtained, but its resistance value varies wildly depending on the crosstalk conditions when blending carbon black with chloroprene rubber, and in this way, When the obtained conductive chloroprene rubber is subjected to external forces such as stretching, compression, and bending, its resistance value increases.
The disadvantage is that the conductivity is significantly reduced, so
The reliability of conductive chloroprene rubber was not established.

An object of the present invention is to eliminate the above-mentioned drawbacks and to provide a conductive chloroprene rubber composition that does not cause fluctuations in volume resistivity due to crosstalk conditions when blending carbon black or external force t9.

"Summary of the Invention" The present invention includes a Jooaa part of chloroprene rubber, a part of Ketjen Black EC2-2 Offi, and an average particle size of 1 part.
It is characterized in that 10 to 70 parts by weight of non-conductive carbon black of 1 mμ or more is added.

The chloroprene rubber used in the present invention is G type, W type
Examples include various grades such as type, GW type, T type, and even gel type.

For Ketjenblack EC, a commercially available product (for example, manufactured by Akzo of the Netherlands or manufactured by Lion Corporation) is used.
The reason for adding m2 to 20 ffl is that if it is less than 2 parts by weight, sufficient conductivity cannot be obtained, and if it is more than 20 parts by weight, the viscosity becomes high and processing becomes difficult.

Further, examples of non-conductive carbon black having an average particle diameter of 11 mμ or more include furnace black and thermal black.

And as a furnace black, 5AF1S8F
-1-1s, 5AF-LS, l5AF.

l5AF-1-1s, ISAF-LSllSAF-LM
, l-l5AF-H8, HAF, 1-I A F -H
S, HAF-LS.

) IAF-LS-3C, MAF, FEF, ]2 [F-
LS, HMF, SRF, SRF-HS, SR
F-LM, 5RF-LS, 5PF-1GPF.

There are APF, FFCF, SC, F, ECI=, etc.

Furthermore, examples of thermal black include FT and MT. Products made in the United States have a slow vulcanization rate [N: normal, S:
N-11
They are classified by names such as 0 (equivalent to SAF) and N-3301 AF (equivalent), but they are all included in the above-mentioned display types that are commonly used in this country. The reason why these additions (1) should be 10 to 70 parts by weight is that if the amount is less than 10 mm part, the volume resistivity of the conductive chloroprene rubber obtained will be unstable, and if it is more than 70 parts by weight, the viscosity will become high and processing will be difficult. This is to become.

[Example] The present invention will be described in detail below. Table 1 shows Examples of the present invention and Comparative Examples, and Examples 1 to 4 all have little variation in volume resistivity and exhibit good conductivity. In addition, it has good extrusion processability, and its tensile properties meet the standards for internal sheathing material for chloroprene sheathed explosion-proof cabtie A7 cables. On the other hand, Comparative Examples 1 to 4 have defects in extrusion processability, volume resistivity, tensile properties, etc., and are not suitable for practical use.

Note that these experiments were conducted as follows. First, the material is prepared by weighing a predetermined amount of chloroprene rubber, carbon black, vulcanizing agent, and other compounding agents, and then kneading them at room temperature using a 6' open roll. 5 minutes after entering the blend rubber, then heated to 145℃ by steam press.
Vulcanization molding was carried out under the conditions of x40 minutes to obtain a sheet of approximately 0.2 mm. Volume resistivity is 3cm x 8an x 0.2cpa
Lead wires were attached to both ends of the strip-shaped sample, and silver paint was applied to these areas to improve contact between the lead wires and the sample, and measurements were made using the Wheatstone bridge method. All other properties are JIS except for tear strength.
Measured according to the regulations.

The conductive chloroprene rubber composition obtained by this invention can be used as an inner sheath for explosion-proof cabtire cables, and can also be applied to other conductive molded products, such as backings and vibration-proofing materials, to improve volume resistivity. It can exhibit constant and excellent practical effects.

[As described in detail, the present invention provides an S-electrochloroprene rubber composition in which the volume resistivity does not fluctuate due to crosstalk conditions when blending carbon black or when subjected to external forces. By using this conductive chloroprene rubber composition for the inner sheath layer, a high-performance chloroprene sheathed explosion-proof cabtie A7 cable can be easily produced, which is an excellent industrial effect. can.

Claims (1)

[Claims] Conductive chloroprene rubber characterized by adding 2 to 20 parts by weight of Touch 1 black E0 and 910 to 0 parts by weight of non-conductive carbon bluff with an average particle size of 11γnμ or more to 100 parts by weight of chloroprene rubber. Composition.