Abstract: In a first embodiment of a process for making mercaptoalkylalkoxysilanes, a pH adjusting agent and a sulfide containing compound are mixed in an aqueous phase to provide a pH of 4-9, a phase transfer catalyst is added to the aqueous phase, a haloalkylalkoxysilane is then added to the aqueous phase to form a reaction mixture containing mercaptoalkylalkoxysilanes and water soluble byproducts, and the desired mercaptoalklyalkoxysilanes are separated from the water soluble byproducts. In an alternate embodiment, the haloalkylalkoxysilane, the phase transfer catalyst, and an anhydrous pH adjusting agent such as sulfur dioxide, carbon dioxide, hydrogen sulfide, phosphoric acid, boric acid, and hydrochloric acid, are mixed, then an aqueous solution of a sulfide containing compound is added to form a reaction mixture containing mercaptoalkylalkoxysilanes and water soluble byproducts, and desired mercaptoalklyalkoxysilanes are separated from water soluble byproducts.

Abstract: A process for the production of sulfur containing organosilicon compounds of the formula: (RO)3−mRmSi—Alk—Sn—Alk—SiRm(OR)3−m where R is independently a monovalent hydrocarbon of 1 to 12 carbon atoms; Alk is a divalent hydrocarbon of 1 to 18 carbon atoms; m is an integer of 0 to 2, n is a number from 1 to 8; based on phase transfer catalysis techniques is disclosed. The process comprises reacting: (A) a sulfide compound having the formula M2Sn or MHS, where H is hydrogen, M is ammonium or an alkali metal, n is as defined above, with (B) a silane compound of the formula; (RO)3−mRmSi—Alk—X where X is Cl, Br or I, and m is the same as above, and optionally, (C) sulfur in the presence of a phase transfer catalyst and an aqueous phase containing a buffer. The improvement of the present invention is characterized by adding a buffer to the aqueous phase, which minimizes or prevents gelling of the sulfur containing organosilicon compounds.

Abstract: A process for the production of sulfur containing organosilicon compounds of the formula:

Abstract: An improved process for the production of organosilicon compounds of the formula (RO)3−mRmSi—Alk—Sn—Alk—SiRm(OR)3−m where R is independently a monovalent hydrocarbon of 1 to 12 carbon atoms, Alk is a divalent hydrocarbon of 1 to 18 carbon atoms; m is an integer of 0 to 2, n is a number from 1 to 8 is disclosed.

Abstract: A process for the production of organosilicon compounds of the formula (RO)3−mRmSi—Alk—Sn—Alk—SiRm(OR)3−m where R is independently a monovalent hydrocarbon of 1 to 12 carbon atoms, Alk is a divalent hydrocarbon of 1 to 18 carbon atoms; m is an integer of 0 to 2, n is a number from 1 to 8 is disclosed. The process comprises: (A) reacting sulfur, a phase transfer catalyst, a sulfide compound having the formula M2Sn or MHS, where H is hydrogen, M is ammonium or an alkali metal, n is the same as above,  and water to form an intermediate reaction product; (B) reacting said intermediate reaction product with  a silane compound of the formula; (RO)3−mRmSi—Alk—X  where X is Cl, Br or I, and m is the same as above. The invention provides an improvement process characterized by adding the phase transfer catalyst to the aqueous phase prior to mixing the aqueous phase with the silane compound for the reaction.

Abstract: A process for the production of organosilicon compounds of the formula: (RO)3−mRmSi-Alk-Sn-Alk-SiRm(OR)3−m where R is independently a monovalent hydrocarbon of 1 to 12 carbon atoms; Alk is a divalent hydrocarbon of 1 to 18 carbon atoms; m is an integer of 0 to 2, n is a number from 1 to 10; is disclosed. The process comprises: (A) reacting an alkali metal hydroxide compound, a sulfide compound having the formula M2Sn or MHS, where H is hydrogen, M is ammonium or an alkali metal, n is as defined above,  and sulfur in water to form a polysulfide mixture, (B) reacting said polysulfide mixture with a silane compound of the formula; (RO)3−mRmSi-Alk-X where X is Cl, Br or I, and m is the same as above, in the presence of a phase transfer catalyst. The process provides sulfur containing organosilicon compounds based on phase transfer catalysis techniques that result in a final product composition having greater stability, purity, and appearance.