This organopolysiloxane composition for use in release paper or release film, said organopolysiloxane composition containing (A) an organopolysiloxane having two or more silicon atom-bonded alkenyl groups in each molecule, (B) an organohydrogen polysiloxane having two or more silicon atom-bonded hydrogen atoms (Si—H groups) on average in each molecule, (C) an organic peroxide and (D) a specific amount of a platinum group metal-based catalyst, is capable of undergoing an addition reaction with a smaller amount of the platinum group metal-based catalyst in comparison to the prior art, thereby being capable of forming a cured coating film which has a release strength equivalent to that of the prior art even in cases where a component that inhibits the catalytic activity of the platinum group metal-based catalyst is contained in the composition. In addition, this organopolysiloxane composition is capable of forming a cured coating film by means of an addition reaction even on a base material containing a catalyst poison component, on said base material conventional compositions being not able to be cured.

The present invention is a thermally conductive sheet comprising a plurality of unit layers, each comprising a silicone resin and a thermally conductive filler, the plurality of unit layers being laminated such that the plurality of unit layers are adhered to each other, wherein a volume content of the silicone resin is 32% by volume or less, and a compressive load at a sheet area of 25.4 mm×25.4 mm when the thermally conductive sheet is 30% compressed from a direction perpendicular to an adhesion plane on which the plurality of unit layers are adhered to each other is 7.0 kgf or less. According to the present invention, it is possible to improve the thermal conductivity and enhance the softness of a thermally conductive sheet using a silicone resin as a matrix component and composed of a large number of unit layers laminated as compared with the conventional one.

A curable hot-melt silicone composition that is less susceptible to curing inhibition and with excellent storage stability, and a sheet or film containing the same, is provided. The composition comprises: (A) a solid organopolysiloxane resin containing a specific ratio of (A1) an organopolysiloxane resin having a curing reactive functional group that contains a carbon-carbon double bond and containing 20 mol % or more of a Q unit, and (A2) an organopolysiloxane resin not having a curing reactive functional group that contains a carbon-carbon double bond and containing 20 mol % or more of a Q unit; (B) a chain organopolysiloxane having a curing reactive functional group that contains at least two carbon-carbon double bonds; (C) an organohydrogenpolysiloxane resin having a mass loss ratio relative to pre-exposure of 10% or less after exposure to 100° C. for 1 hour under atmospheric pressure; and (D) a hydrosilylation reaction catalyst. The composition generally has hot-melt properties.

The invention relates to a silicone rubber composition having specific dielectric properties which can be used as insulator material in high voltage direct current applications and a method for the manufacture of cable accessories like cable joints. The invention comprises as well a method for the determination of the optimum dielectric properties and the related amount of dielectric active additives.

An (A) additive organopolysiloxane composition is disclosed, which includes (A1) a branched organopolysiloxane polymer comprising M, D and Q siloxy units, (A2) a silicone resin, and (A3) a polydiorganosiloxane oligomer. A curable composition is also disclosed, the curable composition including the (A) additive organopolysiloxane composition, (B) an organosilicon compound having at least two silicon-bonded hydrogen atoms per molecule, and (C) a hydrosilylation catalyst. A method of preparing the curable composition, and a method of forming a film with the curable composition are also disclosed. The compositions and methods are useful for forming silicone release coatings with high release force.

Methods for plasma depositing polymers comprising cyclic siloxanes and related articles and compositions are generally provided. In some embodiments, the methods comprise flowing a precursor gas in proximity to a substrate within a PECVD reactor, wherein the precursor gas comprises an initiator and at least one monomer comprising a cyclic siloxane and at least two vinyl groups, and depositing a polymer formed from the at least one monomer on the substrate.

Cyclopentadienyl platinum complexes bearing ethylenic unsaturation are efficient photocatalysts for hydrosilylation of compounds containing aliphatic carbon-carbon multiple bonds, while exhibiting extended dark time, and are particularly useful in addition-curable organopolysiloxane compositions.

The present invention relates to a hardenable silicone composition including an irradiation-activated system for temporarily inhibiting the hydrosilylation reaction. Said system includes at least one inhibitor selected from among α-acetylenic alcohols, α-α′-acetylenic diesters, conjugated ene-yne compounds, α-acetylenic ketones, acrylonitriles, maleates, fumarates, the mixture thereof, at least one photoinitiator, and tris(trimethylsilyl)silane (TTMSS). The invention also relates to a method for preparing a silicone coating and hard elastomer materials provided comprising said silicone composition.

The present invention relates to a curable silicone composition comprising: (A) at least one organopolysiloxane having at least two alkenyl groups per molecule; (B) at least one mercapto functional organopolysiloxane having at least two thiol groups per molecule; (C) at least one photopolymerization initiator; and, (D) 2,6-di-tert-butyl-4-methylphenol (BHT), wherein the composition has a viscosity of less than 200 mPa.Math.s at 25° C.

A crosslinked silicone material Y obtained by heating to a temperature of between 70 and 200° C., a crosslinkable composition X including an organopolysiloxane compound A containing, per molecule, at least two C.sub.2-C.sub.6 alkenyl radicals bonded to silicon atoms; an organohydrogenopolysiloxane compound B containing, per molecule, at least two hydrogen atoms bonded to an identical or different silicon atom; a catalyst C of formula [Ni(L.sup.1).sub.2] where Ni represents nickel at degree of oxidation II; L.sup.1 which may be identical or different, represents a β-dicarbonylato anion or the enolate anion of a β-dicarbonylated compound; optionally an adhesion promoter D; and optionally a charge E.