Abstract: A polymer composition comprises a polymer matrix and a siloxane-containing additive which is substantially incompatible with the polymer matrix, wherein the siloxane of the additive has a hydroxy, alkoxy or epoxy functionality, and a functionality which is capable of bonding with a silicone elastomer-forming composition which is curable by a hydrosilylation reaction. The polymer matrix preferably comprises polyphenylenesulphide, and the additive preferably comprises hydroxy-terminated methylvinyl siloxane. The composition is capable of forming plastics articles to which cured silicone elastomers can adhere.

Abstract: A method for preparing a microporous silicone resin which can be used to form low dielectric constant films useful for electrical insulating coatings on electronic devices comprising (A) contacting a hydridosilicon containing resin with an alkenyltriarylsilane in the presence of a platinum group metal-containing hydrosilation catalyst effecting formation of a silicon resin where at least 5 percent of silicon atoms are substituted with at least one triarylsilylalkylene group and at least 45 percent of silicon atoms are substituted with at least one hydrogen atom and (B) heating the silicon resin of step (A) in an inert atmosphere at a temperature sufficient to effect thermolysis of the triarylsilylalkylene groups from the silicon atoms.

Abstract: A method for purifying 3-methacryloxypropyldimethylhalosilanes or 3-methacryloxypropylmethyldihalosilanes which is characterized by the fact that 1-methyl-2-methacryloxyethyldimethylhalosilanes or 1-methyl-2-methacryloxyethylmethyldihalosilanes contained in products or fractions consisting of 3-methacryloxypropyldimethylhalosilanes or 3-methacryloxypropylmethyldihalosilanes produced by a hydrosilation reaction of allyl methacrylate with dimethylhalosilanes or methyldihalosilanes are decomposed by means of a metal halide which shows the properties of a Lewis acid, after which these compounds are subjected to fractional distillation.

Abstract: A method for making a hydrocarbon oxysilyl functional polymer, which is important as a modified silicone or silicone-modified polymer, by a hydrosilylation reaction between a hydride (hydrocarbonoxy)silane compound having SiH functional groups and a polymer having olefinic or acetylenic unsaturated groups in the presence of a carboxylic acid and a catalytic amount of platinum or a platinum compound.

Abstract: A method for the preparation of hydrophobic precipitated silica. The method comprises contacting an aqueous suspension of a hydrophilic precipitated silica with (1) a catalytic amount of an acid and (2) an organosilicon compound in the presence of (3) a water-miscible organic solvent in an amount sufficient to facilitate reaction of the hydrophilic precipitated silica with the organosilicon compound to form a hydrophobic precipitated silica.

Abstract: A continuous process for producing a silicone polymer comprises the sequential steps of (i) polymerisation of a linear silanol group containing siloxane by condensation polymerisation, or of a cyclosiloxane by ring opening polymerisation, or of a mixture of said linear and cyclosiloxanes with a phosphazene base in the presence of water and the presence or absence of a filler in a static mixer, (ii) neutralising the reaction mixture in a static mixer, an in-line mixer or an extruder, and (iii) stripping the neutralised reaction mixture to remove volatile materials. Preferably step (ii) is performed in a static mixer and step (iii) is performed in a thin film stripper, extruder or co-rotating processor.

Abstract: A Heat-curable silicone rubber composition comprising (A) 100 weight parts organopolysiloxane with the average unit formula RXSiO(4−x)/2 each R is independently selected from the group consisting of hydroxyl and substituted and unsubstituted monovalent hydrocarbon groups and x has a value from 1.9 to 2.1 and containing at least 2 silicon-bonded alkenyl groups in each molecule, (B) 10 to 100 weight parts reinforcing filler, (C) 0.1 to 10 weight parts carboxiloxane dendrimer that contains at least 3 silicon-bonded hydrogen atoms in each molecule, and (D) 0.1 to 10 weight parts organoperoxide.

Abstract: A method for synthesizing silicon compounds that contain a substituent bonded to silicon through a Si—C bond comprising a platinum-catalyzed hydrosilylation reaction between SiH-substituted silicon compounds and unsaturated group-functional organic compounds or unsaturated group-functional organosilicon compounds and exhibits a high catalyst activity and stability and affords a high positional selectivity in the hydrosilylation reaction product.

Abstract: A process for purifying halosilanes consisting of contacting a mixture comprising a halosilane and a hydrocarbon with silica gel, thereby reducing the hydrocarbon content of the mixture. The present process is particularly useful for removing hydrocarbon contaminates from chlorosilanes, where the hydrocarbon contaminates have a boiling point similar to that of the chlorosilanes.

Abstract: A method for densifying particulate silica and a method for compounding a curable silicone composition comprising a reinforcing silica filler. The method is particularly useful for densifying particulate silica to be used as a continuous feed to a compounding apparatus for preparing curable silicone compositions.

Abstract: A method for preparing a nanoporous silicone resin which can be used to form low dielectric constant films useful for electrical insulating coatings on electronic devices comprising (A) contacting a hydridosilicon containing resin with a 1-alkene comprising about 8 to 28 carbon atoms in the presence of a platinum group metal-containing hydrosilation catalyst effecting formation of an alkylhydridosiloxane resin where at least 5 percent of silicon atoms are substituted with at least one group comprising about 8 to 28 carbon atoms and at least 45 percent of silicon atoms are substituted with at least one hydrogen atom and (B) heating the alkylhydridosiloxane resin of step (A) at a temperature sufficient to effect curing and thermolysis of alkyl groups comprising about 8 to 28 carbon atoms from the silicon atoms thereby forming a nanoporous silicone resin.

Abstract: A method for the preparation of a hydrophobic clay by contacting an aqueous suspension of the clay with an organosilane of formula R.sup.1.sub.a SiX.sub.4-a or an organosiloxane comprising units of formula R.sup.2.sub.n SiO.sub.(4-n)/2 in the presence of an acid and a water-miscible solvent. The resulting clay suspension is then contacted with a water-immiscible solvent to effect separation of the hydrophobed clay from the suspension.

Abstract: A moisture curing composition comprising (a) an oxyalkylene polymer having at least one reactive silicon group in each molecule, (b) bis(3-triethoxysilylpropyl)tetrasulfane, and (c) a condensation catalyst. The presence of the bis(3-triethoxysilylpropyl)tetrasulfane in the composition provides for improved physical properties such as tensile strength and elongation. The present compositions are suitable for use in such applications as sealing materials for construction both in the form of extrudable liquid compositions and as cured preformed configurations such as tapes.

Abstract: A process for making a flowable powdered base suitable for use in the formulation of liquid silicone rubber compositions that can be cured to form silicone elastomers. The process comprises (A) fluidizing a reinforcing silica filler in a high-shear mixer, (B) maintaining the content of the mixer at a temperature below about 60.degree. C. while adding to the mixer a silylating agent, a nitrogen containing compound to facilitate the silylation reaction, and water thereby forming an essentially homogeneous mixture comprising a treated reinforcing silica filler; (C) adding a polydiorganosiloxane having a viscosity of about 0.03 to 300 Pa.s at 25.degree. C. to the mixer and forming a flowable powdered base having an average particle size of from about 1 to 1000 microns, and (D) heating the flowable powdered base under conditions sufficient to remove volatiles.

Abstract: A silicone rubber composition that has excellent discharge and flow characteristics prior to its cure and that cures into a highly transparent silicone rubber comprises:(A) polyorganosiloxane,(B) microparticulate silica,(C) methyloligosiloxane endblocked at one molecular chain terminal by silanol and endblocked at the other terminal by trimethylsiloxy, and(D) a curing agent.

Abstract: The present invention is neutral-aged hydrophobic silica gels having a reduced surface area and a method for their preparation. The method comprises three steps, where in the first step a mixture comprising a silica hydrosol and colloidal silica is contacted with a strong mineral acid at a pH less than about 1 to form a silica hydrogel having incorporated therein colloidal silica. In the second step the silica hydrogel is aged at a pH within a range of about pH 3.5 to pH 8. In the third step the silica hydrogel is contacted with an organosilicon compound in the presence of a catalytic amount of a strong acid to effect hydrophobing of the silica hydrogel to form a hydrophobic silica hydrogel having a surface area within a range of about 100 m.sup.2 /g to 450 m.sup.2 /g in the dry state. In a preferred method the hydrophobic silica hydrogel and is further contacted with a sufficient quantity of a water-immiscible organic solvent to convert the hydrophobic silica hydrogel into a hydrophobic silica organogel.

Abstract: The present invention provides a curable composition which comprises (A) a base-generating substance which generates a base when exposed to the action of ultraviolet light, (B) a siloxane polymer which has silicon-hydrogen bonds (Si--H) capable of reacting with hydroxy groups under the effect of the base to form silicon-oxygen bonds (Si--O) and hydrogen molecules (H.sub.2), and (C) an acid substance. This composition is cured by irradiation with ultraviolet light. During this ultraviolet irradiation, a mask is placed between a coating film of the composition and the radiation source, and the uncured portions of the composition are dissolved and removed so that a pattern is formed. The residual portions are then heated to produce a pattern-cured product.

Abstract: A method for recovering particulate silicon essentially free of silicon containing compounds from a by-product stream containing metal salts and high-boiling silicon containing compounds having a boiling point higher than the sublimation temperature of the metal salts. The method comprises first separating the particulate silicon and other solids from the by-product stream by a method such as filtration. The particulates are then washed with a solvent having a boiling point lower than the sublimation temperature of the metal salt, thereby separating residual high-boiling silicon containing compound from the particulate silicon and other solids. The particulate silicon and other solids are then recovered in a dried form, essentially free of silicon containing compounds, by spray drying at a temperature lower than the sublimation temperature of the metal salt.

Abstract: A silicone rubber composition for application as electrical insulation that cures into a highly water-resistant silicone rubber that has excellent electrical properties and in particular has excellent high-voltage electrical insulation properties. The silicone rubber composition comprises(A) polyorganosiloxane,(B) surface-treated aluminum hydroxide powder surface treated with an organosilane or organosilazane, and(C) curing agent.Also, the composition afforded by the addition of 1 to 200 weight parts (D) microparticulate silica to components (A) to (C).

Abstract: The present invention is organosilicon compounds described by formula (1) ##STR1## and formula (2) ##STR2## were R.sup.1 is selected from the group consisting of hydrogen, dichlorosilyl, trichlorosilyl, methyldichlorosilyl, dimethylchlorosilyl, and trimethylsilyl, each R.sup.2, R.sup.3, and R.sup.4 are independently selected from the group consisting of hydrogen, chlorine, alkoxy radicals comprising 1 to about 12 carbon atoms, aryloxy radicals comprising up to about 12 carbon atoms, aryl radicals comprising up to about 12 carbon atoms, and saturated hydrocarbon radicals comprising 1 to about 12 carbon atoms, and n=2 to 6; and methods for the making of organosilicon compounds described by formulas (1) and (2).