Abstract: A one-component room temperature vulcanizable silicone rubber composition comprising (A) silanol end-terminated polyorganosiloxane base polymer, (B) organotriacyloxysilane cross-linker, (C) polysiloxane-polyether copolymer rheology modifier, and (D) particulate silica. The rheology modifying agent is particularly useful for adjusting the viscosity and plateau stress of the silicone rubber compositions.

Abstract: A method for preparing compounds containing (hydrocarbonoxy)silyl groups by reacting an unsaturated organic compound with a hydrido (hydrocarbonoxy)silane compounds by means of the catalytic action of platinum or a platinum compound in the presence of a carboxylic acid compound.

Abstract: Liquid silicone rubber compositions that prior to cure have good fluidity and excellent moldability and that cure into a highly flame retardant silicone rubber with excellent high-voltage electrical insulating properties. The liquid silicone rubber compositions comprise: (A) polyorganosiloxane; (B) fumed silica; (C) surface-treated zinc carbonate powder as afforded by treating the surface of (a) zinc carbonate powder or basic zinc carbonate powder with (b) an organosilicon compound selected from organosilanes, organosilazanes, and organosiloxane oligomers; (D) polyorganohydrogensiloxane; and (E) platinum catalyst. The liquid silicone rubber compositions may further comprise (F) surface treated aluminum hydroxide powder, (G) triazole compound, and (H) a reaction mixture of (d) platinum compound and (e) 3,5-dimethyl-1-hexyn-3-ol.

Abstract: A method for selecting chemical grade silicon metalloid having improved performance in a direct process for making organohalosilanes. The method comprises (A) heating a chemical grade silicon metalloid sample at a temperature ramp speed controlled to effect a stepwise reduction of oxide impurities present in the chemical grade silicon metalloid to a temperature greater than about 2300.degree. C. in the presence of a carbon source thereby effecting the formation of a reduction product consisting of carbon monoxide and carbon dioxide, (B) determining the amount of the reduction product formed above a temperature of about 1900.degree. C., and (C) selecting a chemical grade silicon metalloid for use in the direct process for making organohalosilanes based upon the amount of the reduction product formed above a temperature of about 1900.degree. C.

Abstract: A silicone rubber composition that does not foam or evolve an unpleasant odor during its cure and that cures into low-surface-tack, non-yellowing silicone rubber moldings comprises:(A) polydiorganosiloxane gum with the average component formula R.sub.a SiO.sub.(4-a)/2 where R represents substituted and unsubstituted monovalent hydrocarbon groups and a is from 1.9 to 2.1,(B) microparticulate silica,(C) bis(ortho-methylbenzoyl)peroxide, and(D) bis(para-methylbenzoyl)peroxide,wherein the component (C) to component (D) weight ratio is from 1:9 to 8:2.

Abstract: The discoloration of a non-acidic room temperature vulcanizable silicone sealant containing a ultraviolet radiation degradable fungicide is delayed by adding zinc oxide.

Abstract: A process for separating a gaseous mixture comprising C.sub.1 chlocarbons and noncondensible gases into a liquid component comprising the C.sub.1 chlorocarbons and a component comprising the noncondensible gases. The method employs a liquid hydrocarbon having an average molecular weight within a range of about 142 to 422 to adsorb the C.sub.1 chlorocarbons from the gaseous mixture. The present process is especially useful for separating methyl chloride from a gaseous mixture resulting from an oxychlorination process where the gaseous mixture further comprises, methane, water vapor, and hydrogen chloride.

Abstract: A method for the preparation of hydrophobic fumed silicas which are useful, for example, as reinforcing fillers in rubber compositions. The method comprises two steps, where in the first step an aqueous suspension of fumed silica is contacted with an organosilicon compound in the presence of a catalytic amount of an acid to effect hydrophobing of the fumed silica. In the preferred method the first step is conducted in the presence of a water miscible organic solvent which facilitates hydrophobing of the fumed silica with the organosilicon compound and the fumed silica has a BET surface area greater than 50 m.sup.2 /g. In the second step the aqueous suspension of the fumed silica is contacted with a water-immiscible organic solvent at a solvent to silica weight ratio greater than 0.1:1 to effect separation of the hydrophobic fumed silica from the aqueous phase. In a preferred process the hydrophobic fumed silica has a surface area within a range of about 100 m.sup.2 /g to 750 m.sup.2 /g.

Abstract: An improved structured packing for use in a liquid-vapor contact column. More specifically in a structured packing for liquid-vapor contact where the structured packing comprises laterally orientated channels having peripheral openings, the improvement comprises substantially occluding the peripheral openings with a barrier film. The present invention also includes an improved liquid-vapor contact column comprising a column shell having positioned within a structured packing comprising an outer surface in non-occlusive proximation to the column shell and laterally orientated channels having peripheral openings through the outer surface, the improvement comprising substantially occluding the peripheral openings with a barrier film.

Abstract: A silicone rubber electrical wire insulating covering formed by curing a composition comprising (A) 100 parts by weight of a polydiorganosiloxane gum, (B) 10 to 150 parts by weight of finely powdered silica, (C) 0.01 to 20 parts by weight of a zinc compound, and (D) 0.1 to 10 parts by weight of a methyl-group-substituted benzoyl peroxide. When cured the composition has good electrical insulating characteristics and does not adhere to electrical conductors.

Abstract: A method for inhibiting polymerization of acrylic-functional silanes comprising forming a mixture comprising an acrylic-functional silane and a polymerization inhibitor described by formula ##STR1## where n is 0 or 1; M is an atom selected from a group consisting of N, P, As, Sb, O, S, Se, Sn, and I; R is an independently selected monovalent hydrocarbon group or hydrogen atom; m is 1, 2, or 3; and X is a conjugate base of an organic acid or inorganic acid.

Abstract: A silicone rubber composition comprising(A) polyorganosiloxane described by average formula R.sub.a SiO.sub.(4-a)/2, where R denotes substituted and unsubstituted monovalent hydrocarbon groups and a is a number from 1.95 to 2.05 and having at least 2 silicon-bonded alkenyl groups in each molecule;(B) microparticulate silica;(C) the reaction mixture of(a) a platinum compound and(b) an organosilicon compound described by general formula ##STR1## where R.sup.1, R.sup.2, and R.sup.3 represent C.sub.1 to C.sub.10 monovalent hydrocarbon groups and a is 1, 2, or 3;(D) curing agent, and optionally(E) triazole compound.

Abstract: A silicone rubber composition that cures into a highly flame-retardant silicone rubber with excellent electrical insulation characteristics and that does so without sacrificing mechanical strength. The silicone rubber composition comprises:(A) polyorganosiloxane described by average formula R.sub.a SiO.sub.(4-a)/, where R denotes substituted and unsubstituted monovalent hydrocarbon groups and a is a number from 1.95 to 2.05 and having at least 2 silicon-bonded alkenyl groups in each molecule;(B) microparticulate silica;(C) the reaction mixture of(a) a platinum compound and(b) a compound containing a carbon-carbon double bond and a carbon-carbon triple bond;(D) curing agent, and optionally(E) a triazole compound.

Abstract: A method for the preparation of hydrophobic precipitated silicas which are useful, for example, as reinforcing fillers in rubber compositions. The method comprises two steps, where in the first step an aqueous suspension of precipitated silica is contacted with an organosilicon compound in the presence of a catalytic amount of an acid to effect hydrophobing of the precipitated silica. In the second step the aqueous suspension of the hydrophobic precipitated silica is contacted with a water-immiscible organic solvent at a solvent to silica weight ratio greater than 5:1 to effect separation of the hydrophobic precipitated silica from the aqueous phase.

Abstract: A liquid silicone rubber composition for a lubricant seal having after it is cured high resistance to lubricant, with high stability displayed even in lubricant that has been subjected to thermal and oxidative degradation, and having its rubber elasticity well maintained. The liquid silicone rubber composition for a lubricant seal comprises the following ingredients: (A) an organopolysiloxane containing 2 or more silicon-atom-bonded alkenyl groups in each molecule; (B) an inorganic filler; (C) an oxide or hydroxide of an alkaline-earth metal with an atomic weight of 40 or greater; (D) an organohydrogensiloxane containing 3 or more silicon-atom-bonded hydrogen atoms in each molecule; and (E) a platinum-type catalyst.

Abstract: A silicone rubber composition that yields silicone rubber whose durometer can be freely reduced without a concomitant reduction in the mechanical properties of the silicone rubber. The reduction in durometer is achieved by controlling the concentration of an organosiloxane having hydrogen substitution on terminal silicon atoms.

Abstract: The present invention is a reactor for the hydrogenation of chlorosilanes at temperatures above about 600.degree. C. The reactor comprises one or more of the following improvements: (1) a reaction chamber formed from a silicon carbide coated carbon fiber composite, (2) a heating element formed from a silicon carbide coated carbon fiber composite, and (3) one or more silicon nitride insulators electrically insulating the heating element.

Abstract: A manufacturing method for making a composite comprising silicone rubber and a thermoplastic resin in high precision and in high productivity. In the method, a thermoplastic resin is injected into the cavity of a mold. Then, a liquid silicone rubber composition which comprises (A) organopolysiloxane, (B) spherical fine particle catalyst consisting of platinum base catalyst-containing thermoplastic resin, (C) organohydrogenpolysiloxane, and (D) hydrosilylation reaction inhibiting compound, is injected into the same mold and cured.

Abstract: A continuous mixer for liquids comprises a casing having a conical interior surface and a discharge outlet at the apex of the cone formed by the conical interior surface, a rotor that rotates at its center on the axis of the cone and has a conical exterior surface whose vertical angle is approximately equal to the vertical angle of the conical interior surface, a pressure-transport device that has one or more feed lines which communicate with a gap between the interior surface of the casing and the exterior surface of the rotor a position removed from the discharge outlet and that delivers one or more liquid inputs under pressure through the feed lines, and a gap-adjustment device capable of axially adjusting the rotor within the casing to adjust the gap. The internal pressure and temperature or the mixer can be controlled or adjusted while the rotor is rotating by changing the gap width along the axial direction.

Abstract: A method for making (meth)acryloxy-functional organosilicon compounds comprising conducting an addition reaction between(A) an acrylate ester or methacrylate ester of an aliphatically unsaturated alcohol and(B) a SiH-functional organosilicon compound in the presence of(C) a hydrosilylation-reaction catalyst and(D) a compound described by general formula ##STR1## where A is a (N,N-dialkylamino)alkyl and R is a monovalent hydrocarbon group or a hydrogen atom. The presence of component (D) in the present method inhibits the generation of reaction by-products and prevents gelation during the addition reaction and very efficiently produces high-purity (meth)acryloxy-functional organosilicon compounds in high yields.