Abstract: A hydrochlorination process for the production of monosilanes from the high-boiling residue resulting from the reaction of organochlorides with silicon metalloid in a process typically referred to as the "direct process." The process comprises (A) forming a mixture comprising the high-boiling residue and an organosilane and (B) contacting the mixture with hydrogen chloride in the presence of a catalytic amount of a catalyst composition effective in promoting the formation of monosilanes from the high-boiling residue. A preferred catalyst composition comprises aluminum trichloride, at least a portion of which may be formed in situ during conduct of the direct process and isolation of the high-boiling residue.

Abstract: A one-step process for the production of monosilanes from the high-boiling residue resulting from the reaction of organochlorides with silicon metalloid in a process typically referred to as the "direct process." The process comprises contacting a mixture comprising the high-boiling residue, an organotrichlorosilane, and hydrogen chloride with a catalytic amount of catalyst composition effective in promoting the formation of monosilanes from the high-boiling residue. A preferred catalyst composition comprises aluminum trichloride, at least a portion of which may be formed in situ during conduct of the direct process and isolation of the high-boiling residue. Typically, the monosilane product of the present process comprises almost exclusively methyltrichlorosilane and tetrachlorosilane.

Abstract: A process for the production of monosilanes from the high-boiling residue resulting from the reaction of organochlorides with silicon metalloid in a process typically referred to as the "direct process." The present process comprises forming a mixture comprising an organosilane and the high-boiling residue and contacting the mixture in the presence of hydrogen gas with a catalytic amount of a catalyst composition effective in promoting the formation of monosilanes from the high-boiling residue. A preferred catalyst composition comprises aluminum trichloride, at least a portion of which may be formed in situ during conduct of the direct process and isolation of the high-boiling residue.

Abstract: A process for treating a by-product stream, resulting from the commercial manufacture of methylchlorosilanes, to remove residual silanes where the residual silanes comprise low-boiling hydrosilanes. The process comprises a first step where the by-product stream is contacted with hydrogen chloride in the presence of a chlorination catalyst to convert the low-boiling hydrosilanes to chlorosilanes. In a second step, the modified by-product stream comprising the chlorosilanes is contacted with activated carbon which adsorbs higher-boiling silanes including chlorosilanes, thereby forming a final by-product stream reduced in lower-boiling hydrosilanes and in total silanes. The present process is especially useful for removing silanes from by-product streams intended for incineration, thus reducing silica during combustion of the by-product stream in the incinerator.

Abstract: The present invention is an improved process for the reaction of an alkyl halide with particulate silicon in a fluidized-bed process. The improvement comprises controlling the particle size of the silicon within a range of one micron to 85 microns. Preferred is when the particle size of the silicon has a mass distribution characterized by a 10th percentile of 2.1 to 6 microns, a 50th percentile of 10 to 25 microns, and a 90th percentile of 30 to 60 microns. Most preferred is when the particle size mass distribution of the silicon is characterized by a 10th percentile of 2.5 to 4.5 microns, a 50th percentile of 12 to 25 microns, and a 90th percentile of 35 to 45 microns. The process is run in the presence of a catalyst composition comprising copper and other catalysts.

Abstract: The present invention is a process for the preparation of organofunctional-terminated polydiorganosiloxane polymers and organofunctional polydiorganosiloxane copolymers. The process comprises reacting a chlorine-terminated polydiorganosiloxane polymer with: (1) an organofunctional chlorosilane end-blocker to form an organofunctional terminated polydiorganosiloxane polymer and (2) a mixture of organochlorosilane end-blocker and organofunctional dichlorosilane to form an organofunctional polydiorganosiloxane copolymer. The process is conducted in the presence of an aqueous solution of hydrogen chloride, where the water is present in stoichiometric excess in relation to the hydrolyzable silicon-bonded chlorine.The present process is particularly useful for producing 5-hexenyl-terminated polydimethylsiloxane polymers and for producing siloxane copolymers comprising randomly distributed poly-5-hexenylmethylsiloxy and polydimethylsiloxy blocks.

Abstract: The present invention is a process for preparation of cyclic organohydrosiloxanes. The process comprises contacting an organohydrodihalosilane with a substantially stoichiometric quantity of water to form a mixture containing cyclic and short-chain linear organohydrosiloxanes. This mixture is distilled to separate the cyclic and short-chain linear organohydrosiloxanes from other components of the mixture. The separated cyclic and short-chain linear organohydrosiloxanes are then contacted with an additional quantity of water to effect hydrolysis and condensation of the short-chain linear organohydrosiloxanes to higher molecular weight linear organohydrosiloxanes which are easily separated from the cyclic organohydrosiloxanes by a second distillation step.

Abstract: The instant invention is a one-step process for producing polydiorganosiloxanes (siloxanes). In the described process, a mixture comprising diorganodichlorosilane and a source of triorganosilyl groups is contacted with excess water essentially saturated with hydrogen chloride. Product siloxanes are isolated as well as saturated aqueous hydrogen chloride and anhydrous hydrogen chloride. The amount of triorganosilyl groups present in the mixture is controlled to set the degree of polymerization of product siloxanes. The isolated saturated aqueous hydrogen chloride is recycled to the process. Excess chloride generated in the process is collected as anhydrous hydrogen chloride.

Abstract: The instant invention is a catalyzed process for the redistribution of linear, chloride or hydroxy end-terminated polyorganosiloxanes or cyclic polyorganosiloxanes. Effective catalysts for the described process are alumina, silica-alumina, activated carbon, zeolite, and acid clay. The catalyzed redistribution process can be incorporated as an element of a three-stage process. The three-stage process allows control of the yield of cyclic polyorganosiloxanes.