The present invention discloses a silicone rubber and a method for preparing it, and a phenolic modified silicone rubber resin and a method for preparing it. The structural formula of the silicone rubber is shown as follows: ##STR00001## Wherein x=70-80, y=10-20. The structural formula of the phenolic-modified silicone rubber resin is shown as follows: ##STR00002## wherein n, x, y are degrees of polymerization, n=10-20, x=70-80, y=10-20. A method for preparing the phenolic-modified silicone rubber resin orderly comprises: adding 90-110 parts by mass of brominated phenolic resin and 180-220 parts of organic solvent into 100 parts by mass of silicone rubber, reacting at 70-80° C. for 24-48 h until the solution is clear and transparent; adding 9-11 parts by mass of capping agent, reacting for another 4-5 h to obtain a reaction liquid containing phenolic-modified silicone rubber resin. The phenolic-modified silicone rubber resin prepared in the present invention can solve the problem of easy pulverization in the ablation process of conventional silicone rubber and meanwhile has high mechanical properties.

Intermediate laminates and articles comprising a low adhesion backsize coating are described. The laminate comprises a substrate having a major surface and opposing surface and a coating comprising a block copolymer disposed on a major surface of the substrate wherein the block copolymer comprises a polyorganosiloxane block and a polyolefin block, the polyolefin block having a melt point of at least 110° C. Also described are medical dressings comprising such laminate.

Provided are rapidly cross-linkable silicone foam compositions, kits, and methods for filling implanted medical devices in situ or in vivo, the implanted medical devices, including for example, body implants and tissue expanders, the compositions including a platinum divinyl disiloxane complex; a low viscosity vinyl terminated polydimethylsiloxane; a low viscosity hydride terminated polydimethylsiloxane; a silicone cross-linker; and a gas and/or gas-filled microcapsules, where the rapidly cross-linkable silicone foam composition has a viscosity of ≤150 cPs for ≥1 min. post-preparation and ≤300 cPs≤5 min. post-preparation, at ambient temperature.

Provided are rapidly cross-linkable silicone foam compositions, kits, and methods for filling implanted medical devices in situ or in vivo, the implanted medical devices, including for example, body implants and tissue expanders, the compositions including a platinum divinyl disiloxane complex; a low viscosity vinyl terminated polydimethylsiloxane; a low viscosity hydride terminated polydimethylsiloxane; a silicone cross-linker; and a gas and/or gas-filled microcapsules, where the rapidly cross-linkable silicone foam composition has a viscosity of ≤150 cPs for ≥1 min. post-preparation and ≤300 cPs≤5 min. post-preparation, at ambient temperature.

Provided is a curable silicone composition and applications thereof. The curable silicone composition has low modulus and flexibility even at high temperature of a cured product formed therefrom, and superior stress relaxation properties, so that the cured product does not readily warp or become defective when integrally molded with a base material, and has superior demolding property (e.g. mold release) of the cured product after transfer molding. A curable silicone composition for transfer molding, where (1) the maximum torque measured from a molding temperature of room temperature through 200° C. using a moving die rheometer (MDR) is less than 50 dN-m, and (2) the loss tangent (tans) expressed by the ratio of stored torque value/lost torque value is less than 0.2.

Provided is a curable silicone composition and applications thereof. The curable silicone composition has low modulus and flexibility even at high temperature of a cured product formed therefrom, and superior stress relaxation properties, so that the cured product does not readily warp or become defective when integrally molded with a base material, and has superior demolding property (e.g. mold release) of the cured product after transfer molding. A curable silicone composition for transfer molding, where (1) the maximum torque measured from a molding temperature of room temperature through 200° C. using a moving die rheometer (MDR) is less than 50 dN-m, and (2) the loss tangent (tans) expressed by the ratio of stored torque value/lost torque value is less than 0.2.

Curable silsesquioxane polymers are described comprising a core comprising a first silsesquioxane polymer and an outer layer comprising a second silsesquioxane polymer bonded to the core. The silsesquioxane polymer of the core, outer layer, or combination thereof comprises reactive groups that are not ethylenically unsaturated groups. The first silsesquioxane polymer of the core is bonded to the second silsesquioxane polymer of the outer layer via silicon atoms bonded to three oxygen atoms. In some embodiments, the outer layer has a higher concentration of reactive groups than the core. In this embodiment, the core may be substantially free of reactive groups. In other embodiments, the core has a higher concentration of reactive groups than the core. In this embodiment, the outer layer may be substantially free of reactive groups. The core and outer layer each comprise a three-dimensional branched network of a different silsesquioxane polymer. The silsesquioxane polymers of the core and outer layer may be homopolymers or copolymers. Also described are methods of preparing curable silsesquioxane polymer comprising a core and outer layer bonded to the core, articles comprising curable or cured compositions comprising the silsesquioxane core/outer layer polymers, and methods of curing.

The present disclosure provides hydrosilylation curable compositions comprising resin linear organosiloxane block copolymers comprising, among other things, from about 0.5 to about 5 mole % C.sub.1 to C.sub.30 hydrocarbyl group comprising at least one aliphatic unsaturated bond. Such hydrosilylation curable resin-linear organosiloxane block copolymers have significantly faster cure speed, relative to their condensation curable counterparts. A faster cure speed can be important for encapsulating electronic devices, such as light-emitting diode (LED) chip devices, particularly devices having tall structures.

The present disclosure provides hydrosilylation curable compositions comprising resin linear organosiloxane block copolymers comprising, among other things, from about 0.5 to about 5 mole % C.sub.1 to C.sub.30 hydrocarbyl group comprising at least one aliphatic unsaturated bond. Such hydrosilylation curable resin-linear organosiloxane block copolymers have significantly faster cure speed, relative to their condensation curable counterparts. A faster cure speed can be important for encapsulating electronic devices, such as light-emitting diode (LED) chip devices, particularly devices having tall structures.

The present invention relates to an emulsion-based high release additive for a release sheet, the additive being characterized by being obtained by dispersing in water a condensation product (A) obtained by subjecting the following to a dehydration condensation reaction: (A-1) a polydiorganosiloxane which has an average degree of polymerization of 100-300,000 and which has one or more hydroxyl groups or hydrolyzable groups per molecule; and (A-2) a polyorganosiloxane resin, which contains (SiO.sub.4/2) units and (R.sub.3SiO.sub.1/2) units (in the formulae, the R groups each represent independently a monovalent hydrocarbon group having 1-12 carbon atoms and not having an aliphatic unsaturated bond or an alkenyl group having 2-6 carbon atoms) as primary components, in which the molar ratio of (R.sub.3SiO.sub.1/2) units relative to (SiO.sub.4/2) units is 0.6-1.2 and in which the total content of hydroxyl groups and hydrolyzable groups is not lower than 2.1 mass % and lower than 10.0 mass %. The present invention can obtain a silicone cured coating film having a high release force by adding the additive to a curable composition for a release sheet such as a release paper or release film, coating the same on a variety of base materials and curing.