Curable organosiloxane compositions and semiconductor devices

Claim 2

A curable organopolysiloxane composition consisting essentially of: (A) 100 weight parts of a mixture of (a) 5 to 95 weight % of an alkoxy-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkoxy groups per molecule, and wherein the alkoxy-substituted organopolysiloxane is free of silicon-bonded alkenyl groups; and (b) 95 to 5 weight % of an alkenyl-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkenyl groups per molecule, and wherein the alkenyl-substituted organopolysiloxane is free of silicon-bonded alkoxy groups; and (B) a polyorganosiloxane having a viscosity at 25° C. of 2 to 20,000 mPa.s and containing an average of at least two silicon-bonded hydrogen atoms per molecule, in a quantity that affords a value of 0.5 to 20 for the molar ratio of silicon-bonded hydrogen atoms in component (B) to silicon-bonded alkenyl groups in component (b); (C) 0.01 to 10 parts by weight of a condensation reaction catalyst selected from the group consisting of organotitanium, organozirconium, and organoaluminum condensation reaction catalysts; and (D) platinum catalyst in a catalytic quantity.

Claim 3

The curable organosiloxane composition of claim 1 further comprising (E) 50 to 2000 weight parts of an electrically conductive filler.

Claim 4

The curable organosiloxane composition of claim 2 wherein component (E) is present in an amount ranging from 300 to 1000 parts by weight per 100 parts by weight of component (A).

Claim 5

The curable organosiloxane composition of claim 2 wherein component (E) is selected from the group consisting of gold micropowder and silver micropowder.

Claim 6

The curable organosiloxane composition of claim 4 wherein component (E) is silver micropowder.

Claim 7

The curable organosiloxane composition of claim 1 wherein the silicon-bonded alkoxy groups of component (a) are individually selected from the group consisting of methoxy, ethoxy, propoxy, butoxy, methoxymethoxy and methoxyethoxy.

Claim 8

The curable organosiloxane composition of claim 6 wherein the silicon-bonded alkoxy groups of component (a) are methoxy.

Claim 9

The curable organosiloxane composition of claim 1 wherein the viscosity of at 25° C. of component (a) is from 100 to 100,000 mPa.s.

Claim 10

The curable organosiloxane composition of claim 1 wherein the silicon-bonded alkenyl groups of component (b) are individually selected from the group consisting of vinyl, allyl, butenyl, pentenyl and hexenyl.

Claim 11

The curable organosiloxane composition of claim 9 wherein the silicon-bonded alkenyl groups of component (b) are vinyl.

Claim 12

The curable organosiloxane composition of claim 1 wherein the viscosity of at 25° C. of component (b) is from 100 to 100,000 mPa.s.

Claim 13

The curable organosiloxane composition of claim 1 wherein component (C) is present in an amount ranging from 0.1 to 5 weight parts per 100 weight parts component (A).

Claim 14

A product prepared by admixing materials consisting essentially of: (A) 100 weight parts of a mixture of (a) 5 to 95 weight % of an alkoxy-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkoxy groups per molecule, and wherein the alkoxy-substituted organopolysiloxane is free of silicon-bonded alkenyl groups; and (b) 95 to 5 weight % of an alkenyl-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkenyl groups per molecule, and wherein the alkenyl-substituted organopolysiloxane is free of silicon-bonded alkoxy groups; and (B) a polyorganosiloxane having a viscosity at 25° C. of 2 to 20,000 mPa.s and containing an average of at least two silicon-bonded hydrogen atoms per molecule, in a quantity that affords a value of 0.5 to 20 for the molar ratio of silicon-bonded hydrogen atoms in component (B) to silicon-bonded alkenyl groups in component (b); (C) 0.01 to 10 parts by weight of a condensation reaction catalyst selected from the group consisting of organotitanium, organozirconium, and organoaluminum condensation reaction catalysts; and (D) platinum catalyst in a catalytic quantity.

Claim 15

A product prepared by admixing materials consisting essentially of: (A) 100 weight parts of a mixture of (a) 5 to 95 weight % of an alkoxy-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkoxy groups per molecule, and wherein the alkoxy-substituted organopolysiloxane is free of silicon-bonded alkenyl groups; and (b) 95 to 5 weight % of an alkenyl-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkenyl groups per molecule, and wherein the alkenyl-substituted organopolysiloxane is free of silicon-bonded alkoxy groups; and (B) a polyorganosiloxane having a viscosity at 25° C. of 2 to 20,000 mPa.s and containing an average of at least two silicon-bonded hydrogen atoms per molecule, in a quantity that affords a value of 0.5 to 20 for the molar ratio of silicon-bonded hydrogen atoms in component (B) to silicon-bonded alkenyl groups in component (b); (C) 0.01 to 10 parts by weight of a condensation reaction catalyst selected from the group consisting of organotitanium, organozirconium, and organoaluminum condensation reaction catalysts; and (D) platinum catalyst in a catalytic quantity.

Claim 16

A product prepared by admixing materials consisting essentially of: (A) 100 weight parts of a mixture of (a) 5 to 95 weight % of an alkoxy-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkoxy groups per molecule, and wherein the alkoxy-substituted organopolysiloxane is free of silicon-bonded alkenyl groups; and (b) 95 to 5 weight % of an alkenyl-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkenyl groups per molecule, and wherein the alkenyl-substituted organopolysiloxane is free of silicon-bonded alkoxy groups; and (B) a polyorganosiloxane having a viscosity at 25° C. of 2 to 20,000 mPa.s and containing an average of at least two silicon-bonded hydrogen atoms per molecule, in a quantity that affords a value of 0.5 to 20 for the molar ratio of silicon-bonded hydrogen atoms in component (B) to silicon-bonded alkenyl groups in component (b); (C) 0.01 to 10 parts by weight of a condensation reaction catalyst selected from the group consisting of organotitanium, organozirconium, and organoaluminum condensation reaction catalysts; (D) platinum catalyst in a catalytic quantity; and (E) 50 to 2000 parts by weight of an electrically conductive filler.

Claim 17

A product prepared by admixing materials consisting essentially of: (A) 100 weight parts of a mixture of (a) 5 to 95 weight % of an alkoxy-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkoxy groups per molecule, and wherein the alkoxy-substituted organopolysiloxane is free of silicon-bonded alkenyl groups; and (b) 95 to 5 weight % of an alkenyl-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkenyl groups per molecule, and wherein the alkenyl-substituted organopolysiloxane is free of silicon-bonded alkoxy groups; and (B) a polyorganosiloxane having a viscosity at 25° C. of 2 to 20,000 mPa.s and containing an average of at least two silicon-bonded hydrogen atoms per molecule, in a quantity that affords a value of 0.5 to 20 for the molar ratio of silicon-bonded hydrogen atoms in component (B) to silicon-bonded alkenyl groups in component (b); (C) 0.01 to 10 parts by weight of a condensation reaction catalyst selected from the group consisting of organotitanium, organozirconium, and organoaluminum condensation reaction catalysts; (D) platinum catalyst in a catalytic quantity; and (E) 50 to 2000 parts by weight of an electrically conductive filler.

Claim 18

A curable organosiloxane composition, which is curable via both addition and condensation reactions, said curable organopolysiloxane composition consisting essentially of: (A') 100 parts by weight of an alkenyl-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkenyl groups per molecule; (B') a polyorganosiloxane having a viscosity at 25° C. of 2 to 20,000 mPa.s, and containing an average of at least two silicon-bonded hydrogen atoms per molecule in a quantity that affords a value from 0.5 to 20 for the molar ratio of silicon-bonded hydrogen atoms in component (B') to silicon-bonded alkenyl groups in component (A'); (C) 0.01 to 10 parts by weight of a condensation reaction catalyst selected from the group consisting of organotitanium, organozirconium, and organoaluminum condensation reaction catalysts; and (D) platinum catalyst in a catalytic quantity; with the proviso that at least one of components (A') and (B') contains an average of at least two silicon-bonded alkoxy groups per molecule.

Claim 19

A curable organosiloxane composition, which is curable via both addition and condensation reactions, said curable organopolysiloxane composition consisting essentially of: (A') 100 parts by weight of an alkenyl-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkenyl groups per molecule; (B') a polyorganosiloxane having a viscosity at 25° C. of 2 to 20,000 mPa.s, and containing an average of at least two silicon-bonded hydrogen atoms per molecule in a quantity that affords a value from 0.5 to 20 for the molar ratio of silicon-bonded hydrogen atoms in component (B') to silicon-bonded alkenyl groups in component (A'); (C) 0.01 to 10 parts by weight of a condensation reaction catalyst selected from the group consisting of organotitanium, organozirconium, and organoaluminum condensation reaction catalysts; and (D) platinum catalyst in a catalytic quantity; with the proviso that at least one of components (A') and (B') contains an average of at least two silicon-bonded alkoxy groups per molecule.

Claim 20

The curable organosiloxane composition of claim 15 wherein the silicon-bonded alkenyl groups of component (A') are individually selected from the group consisting of vinyl, allyl, butenyl, pentenyl, hexenyl, and heptenyl.

Claim 21

The curable organosiloxane composition of claim 16 wherein the silicon-bonded alkenyl groups of component (A') are vinyl.

Claim 22

The curable organosiloxane composition of claim 15 wherein the viscosity of at 25° C. of component (A') is from 100 to 100,000 mPa.s.

Claim 23

The curable organosiloxane composition of claim 15 wherein component (C) is present in an amount ranging from 0.1 to 5 weight parts per 100 weight parts component (A').

Claim 24

The curable organosiloxane composition of claim 15 further comprising (E) 50 to 2000 weight parts of an electrically conductive filler.

Claim 25

The curable organosiloxane composition of claim 20 wherein component (E) is present in an amount ranging from 300 to 1000 parts by weight per 100 parts by weight of component (A).

Claim 26

The curable organosiloxane composition of claim 20 wherein component (E) is selected from the group consisting of gold micropowder and silver micropowder.

Claim 27

The curable organosiloxane composition of claim 22 wherein component (E) is silver micropowder.

Claim 28

A product prepared by admixing materials consisting essentially of: (A') 100 parts by weight of an alkenyl-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkenyl groups per molecule; (B') a polyorganosiloxane having a viscosity at 25° C. of 2 to 20,000 mPa.s, and containing an average of at least two silicon-bonded hydrogen atoms per molecule in a quantity that affords a value from 0.5 to 20 for the molar ratio of silicon-bonded hydrogen atoms in component (B') to silicon-bonded alkenyl groups in component (A'); (C) 0.01 to 10 parts by weight of a condensation reaction catalyst selected from the group consisting of organotitanium, organozirconium and organoaluminum condensation reaction catalysts; and (D) platinum catalyst in a catalytic quantity; with the proviso that at least one of components (A') and (B') contains an average of at least two silicon-bonded alkoxy groups per molecule.

Claim 29

A product prepared by admixing materials consisting essentially of: (A') 100 parts by weight of an alkenyl-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkenyl groups per molecule; (B') a polyorganosiloxane having a viscosity at 25° C. of 2 to 20,000 mPa.s, and containing an average of at least two silicon-bonded hydrogen atoms per molecule in a quantity that affords a value from 0.5 to 20 for the molar ratio of silicon-bonded hydrogen atoms in component (B') to silicon-bonded alkenyl groups in component (A'); (C) 0.01 to 10 parts by weight of a condensation reaction catalyst selected from the group consisting of organotitanium, organozirconium and organoaluminum condensation reaction catalysts; and (D) platinum catalyst in a catalytic quantity; with the proviso that at least one of components (A') and (B') contains an average of at least two silicon-bonded alkoxy groups per molecule.

Claim 30

A product prepared by admixing materials consisting essentially of: (A') 100 parts by weight of an alkenyl-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkenyl groups per molecule; (B') a polyorganosiloxane having a viscosity at 25° C. of 2 to 20,000 mPa.s, and containing an average of at least two silicon-bonded hydrogen atoms per molecule in a quantity that affords a value from 0.5 to 20 for the molar ratio of silicon-bonded hydrogen atoms in component (B') to silicon-bonded alkenyl groups in component (A'); (C) 0.01 to 10 parts by weight of a condensation reaction catalyst selected from the group consisting of organotitanium, organozirconium, and organoaluminum condensation reaction catalysts; (D) platinum catalyst in a catalytic quantity; and (E) 50 to 2000 parts by weight of an electrically conductive filler; with the proviso that at least one of components (A') and (B') contains an average of at least two silicon-bonded alkoxy groups per molecule.

Claim 31

A product prepared by admixing materials consisting essentially of: (A') 100 parts by weight of an alkenyl-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkenyl groups per molecule; (B') a polyorganosiloxane having a viscosity at 25° C. of 2 to 20,000 mPa.s, and containing an average of at least two silicon-bonded hydrogen atoms per molecule in a quantity that affords a value from 0.5 to 20 for the molar ratio of silicon-bonded hydrogen atoms in component (B') to silicon-bonded alkenyl groups in component (A'); (C) 0.01 to 10 parts by weight of a condensation reaction catalyst selected from the group consisting of organotitanium, organozirconium, and organoaluminum condensation reaction catalysts; (D) platinum catalyst in a catalytic quantity; and (E) 50 to 2000 parts by weight of an electrically conductive filler; with the proviso that at least one of components (A') and (B') contains an average of at least two silicon-bonded alkoxy groups per molecule.

Claim 32

A semiconductor device comprising (A) a semiconductor chip; (B) a substrate; and (C) a silicone die attach adhesive prepared by curing a curable organosiloxane composition which is curable via both addition and condensation reactions; wherein the semiconductor chip is bonded to the substrate with the silicone die attach adhesive.

Claim 33

A semiconductor device comprising (A) a semiconductor chip; (B) a substrate; and (C) a silicone die attach adhesive prepared by curing a curable organosiloxane composition which is curable via both addition and condensation reactions; wherein the semiconductor chip is bonded to the substrate with the silicone die attach adhesive.

Claim 34

The semiconductor device of claim 26 wherein the curable organosiloxane composition consists essentially of: (A) 100 weight parts of a mixture of (a) 5 to 95 weight % of an alkoxy-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkoxy groups per molecule, and wherein the alkoxy-substituted organopolysiloxane is free of silicon-bonded alkenyl groups; and (b) 95 to 5 weight % of an alkenyl-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkenyl groups per molecule, and wherein the alkenyl-substituted organopolysiloxane is free of silicon-bonded alkoxy groups; and (B) a polyorganosiloxane having a viscosity at 25° C. of 2 to 20,000 mPa.s and containing an average of at least two silicon-bondedhydrogen atoms per molecule, in a quantity that affords a value of 0.5 to 20 for the molar ratio of silicon-bonded hydrogen atoms in component (B) to silicon-bonded alkenyl groups in component (b); (C) 0.01 to 10 parts by weight of a condensation reaction catalyst selected from the group consisting of organotitanium, organozirconium, and organoaluminum condensation reaction catalysts; and (D) platinum catalyst in a catalytic quantity.

Claim 35

The semiconductor device of claim 26 wherein the curable organosiloxane composition consists essentially of: (A) 100 weight parts of a mixture of (a) 5 to 95 weight % of an alkoxy-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkoxy groups per molecule, and wherein the alkoxy-substituted organopolysiloxane is free of silicon-bonded alkenyl groups; and (b) 95 to 5 weight % of an alkenyl-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkenyl groups per molecule, and wherein the alkenyl-substituted organopolysiloxane is free of silicon-bonded alkoxy groups; and (B) a polyorganosiloxane having a viscosity at 25° C. of 2 to 20,000 mPa.s and containing an average of at least two silicon-bonded hydrogen atoms per molecule, in a quantity that affords a value of 0.5 to 20 for the molar ratio of silicon-bonded hydrogen atoms in component (B) to silicon-bonded alkenyl groups in component (b); (C) 0.01 to 10 parts by weight of a condensation reaction catalyst selected from the group consisting of organotitanium, organozirconium, and organoaluminum condensation reaction catalysts; (D) platinum catalyst in a catalytic quantity; and (E) 50 to 2000 weight parts of an electrically conductive filler.

Claim 36

The semiconductor device of claim 26 wherein the curable organosiloxane composition consists essentially of: (A') 100 parts by weight of an alkenyl-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkenyl groups per molecule; (B') a polyorganosiloxane having a viscosity at 25° C. of 2 to 20,000 mPa.s, and containing an average of at least two silicon-bonded hydrogen atoms per molecule in a quantity that affords a value from 0.5 to 20 for the molar ratio of silicon-bonded hydrogen atoms in component (B') to silicon-bonded alkenyl groups in component (A'); (C) 0.01 to 10 parts by weight of a condensation reaction catalyst selected from the group consisting of organotitanium, organozirconium, and organoaluminum condensation reaction catalysts; and (D) platinum catalyst in a catalytic quantity; with the proviso that at least one of components (A') and (B') contains an average of at least two silicon-bonded alkoxy groups per molecule.

Claim 37

The semiconductor device of claim 26 wherein the curable organosiloxane composition consists essentially of: (A') 100 parts by weight of an alkenyl-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkenyl groups per molecule; (B') a polyorganosiloxane having a viscosity at 25° C. of 2 to 20,000 mPa.s, and containing an average of at least two silicon-bonded hydrogen atoms per molecule in a quantity that affords a value from 0.5 to 20 for the molar ratio of silicon-bonded hydrogen atoms in component (B') to silicon-bonded alkenyl groups in component (A'); (C) 0.01 to 10 parts by weight of a condensation reaction catalyst selected from the group consisting of organotitanium, organozirconium, and organoaluminum condensation reaction catalysts; (D) platinum catalyst in a catalytic quantity; and (E) 50 to 2000 weight parts of an electrically conductive filler; with the proviso that at least one of components (A') and (B') contains an average of at least two silicon-bonded alkoxy groups per molecule.

Claim 40

The method of claim 31 wherein the curable organosiloxane composition consists essentially of: (A) 100 weight parts of a mixture of (a) 5 to 95 weight % of an alkoxy-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkoxy groups per molecule, and wherein the alkoxy-substituted organopolysiloxane is free of silicon-bonded alkenyl group; and (b) 95 to 5 weight % of an alkenyl-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkenyl groups per molecule, and wherein the alkenyl-substituted organopolysiloxane is free of silicon-bonded alkoxy groups; and (B) a polyorganosiloxane having a viscosity at 25° C. of 2 to 20,000 mPa.s and containing an average of at least two silicon-bonded hydrogen atoms per molecule, in a quantity that affords a value of 0.5 to 20 for the molar ratio of silicon-bonded hydrogen atoms in component (B) to silicon-bonded alkenyl groups in component (b); (C) 0.01 to 10 parts by weight of a condensation reaction catalyst selected from the group consisting of organotitanium, organozirconium, and organoaluminum condensation reaction catalysts; and (D) platinum catalyst in a catalytic quantity.

Claim 41

The method of claim 31 wherein the curable organosiloxane composition consists essentially of: (A) 100 weight parts of a mixture of (a) 5 to 95 weight % of an alkoxy-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkoxy groups per molecule, and wherein the alkoxy-substituted organopolysiloxane is free of silicon-bonded alkenyl groups; and (b) 95 to 5 weight % of an alkenyl-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkenyl groups per molecule, and wherein the alkenyl-substituted organopolysiloxane is free of silicon-bonded alkoxy groups; and (B) a polyorganosiloxane having a viscosity at 25° C. of 2 to 20,000 mPa.s and containing an average of at least two silicon-bonded hydrogen atoms per molecule, in a quantity that affords a value of 0.5 to 20 for the molar ratio of silicon-bonded hydrogen atoms in component (B) to silicon-bonded alkenyl groups in component (b); (C) 0.01 to 10 parts by weight of a condensation reaction catalyst selected from the group consisting of organotitanium, organozirconium, and organoaluminum condensation reaction catalysts; (D) platinum catalyst in a catalytic quantity; and (E) 50 to 2000 weight parts of an electrically conductive filler.

Claim 42

The method of claim 31 wherein the curable organosiloxane composition consists essentially of: (A') 100 parts by weight of an alkenyl-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkenyl groups per molecule; (B') a polyorganosiloxane having a viscosity at 25° C. of 2 to 20,000 mPa.s, and containing an average of at least two silicon-bonded hydrogen atoms per molecule in a quantity that affords a value from 0.5 to 20 for the molar ratio of silicon-bonded hydrogen atoms in component (B') to silicon-bonded alkenyl groups in component (A'); (C) 0.01 to 10 parts by weight of a condensation reaction catalyst selected from the group consisting of organotitanium, organozirconium, and organoaluminum condensation reaction catalysts; and (D) platinum catalyst in a catalytic quantity; with the proviso that at least one of components (A') and (B') contains an average of at least two silicon-bonded alkoxy groups per molecule.

Claim 43

The method of claim 31 wherein the curable organosiloxane composition consists essentially of: (A') 100 parts by weight of an alkenyl-substituted organopolysiloxane having a viscosity at 25° C. of 20 to 200,000 mPa.s and containing an average of at least two silicon-bonded alkenyl groups per molecule; (B') a polyorganosiloxane having a viscosity at 25° C. of 2 to 20,000 mPa.s, and containing an average of at least two silicon-bonded hydrogen atoms per molecule in a quantity that affords a value from 0.5 to 20 for the molar ratio of silicon-bonded hydrogen atoms in component (B') to silicon-bonded alkenyl groups in component (A'); (C) 0.01 to 10 parts by weight of a condensation reaction catalyst selected from the group consisting of organotitanium, organozirconium, and organoaluminum condensation reaction catalysts; (D) platinum catalyst in a catalytic quantity; and (E) 50 to 2000 weight parts of an electrically conductive filler; with the proviso that at least one of components (A') and (B') contains an average of at least two silicon-bonded alkoxy groups per molecule.