Electrically conductive silicon compositions
AssigneeDow Corning Corporation
InventorLoretta N. Kroupa
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Abstract
An improved electrically conductive polydiorganosiloxane of the type comprising a polydiorganosiloxane and conductive carbon particles has been developed. The improved electrical conductivity results from the addition of a conductivity improver comprising disilazane of the formula (R.sub.3 Si).sub.2 NH where R is a substituted or unsubstituted alkyl radical of from 1 to 6 carbon atoms or hydroxyl endblocked polymethylphenylsiloxane.
Claims8
An electrically conductive composition comprising polydiorganosiloxane and conductive carbon particles, wherein the improvement comprises adding from 6 to 30 parts by weight per 100 parts of the carbon particles of conductivity improver comprising disilazane of the formula (R.sub.3 Si).sub.2 NH where R is a substituted or unsubstituted alkyl radical of from 1 to 6 carbon atoms.
An electrically conductive, curable composition comprising a curable polydiorganosiloxane and a crosslinking agent in combination with conductive carbon particles, wherein the improvement comprises adding from 6 to 30 parts by weight per 100 parts of the carbon particles of conductivity improver comprising disilazane of the formula (R.sub.3 Si).sub.2 NH where R is a substituted or unsubstituted alkyl radical of from 1 to 6 carbon atoms.
A method of preparing an electrically conductive silicone composition comprising
- (A) adding 100 parts by weight of polydiorganosiloxane to a shearing mixer,
- (B) admixing from 3 to 40 parts by weight of conductive carbon particles, and from 6 to 30 parts by weight per 100 parts by weight of the carbon particles of conductivity improver comprising disilazane of the formula (R.sub.3 Si).sub.2 NH where R is a substituted or unsubstituted alkyl radical of from 1 to 6 carbon atoms.
A method of preparing an electrically conductive silicone composition curable to an elastomer comprising
- (A) adding 100 parts by weight of curable polydiorganosiloxane to a shearing mixer,
- (B) admixing from 3 to 40 parts by weight of conductive carbon particles, and from 6 to 30 parts by weight per 100 parts by weight of the carbon particles of a conductivity improver comprising disilazane of the formula (R.sub.3 Si).sub.2 NH where R is a substituted or unsubstituted alkyl radical of from 1 to 6 carbon atoms,
- (C) removing the mixture from the mixer and placing the mixture on a two roll mill, where it is massed and admixed with means for curing the polydiorganosiloxane, to give a curable composition which has a high electrical conductivity when cured and resists change in conductivity when processed.
A method of preparing an electrically conductive silicone composition curable to an elastomer comprising
- (A) adding 100 parts by weight of hydroxyl endblocked polydiorganosiloxane to a shearing mixer,
- (B) admixing from 3 to 40 parts by weight of treated conductive carbon particles obtained from a method of preparing an improved electrically conductive carbon particle comprising
- (a) adding 100 parts by weight of inert solvent to a mixer,
- (b) admixing from 6 to 30 parts by weight per 100 parts by weight of the carbon particles of (C) of conductivity improver selected from the group consisting of disilazane of the formula (R.sub.3 Si).sub.2 NH where R is a substituted or unsubstituted alkyl radical of from 1 to 6 carbon atoms, and hydroxyl endblocked polymethylphenylsiloxane having a viscosity of from 0.1 to 1.0 Pa.s at 25.degree. C.,
- (c) admixing from 3 to 40 parts by weight of conductive carbon particles, and
- (d) drying and powdering the resulting hydrophobic carbon particles.
- (C) removing the mixture from the mixer and placing the mixture on a two roll mill, where it is massed and admixed with means for curing the polydiorganosiloxane, to give a curable composition which has a high electrical conductivity when cured and resists change in conductivity when processed.
Dependencies are inferred from the claim text.