Patent ID: 8008520

Claim:
A process for the preparation of a thiocarboxylate silane represented by at least one of the formulae: (R—Y—S—) a G 2 (—SiX 3 ) c (1) G 1 [—Y—S-G 2 (—SiX 3 ) c ] a (2) [G 1 (—Y—S—) a ] b [G 2 (—SiX 3 ) c ] d (3) wherein: each occurrence of G 1 and G 2 is, independently, a polyvalent alkyl, alkenyl, aryl, or aralkyl group, with each G 1 and G 2 containing from 1 to 40 carbon atoms; each occurrence of R is, independently, selected from the group consisting of hydrogen, and alkyl, alkenyl, alkynyl, aryl, and aralkyl groups, with each R containing from 0 to 30 carbon atoms; Y is carbonyl, C(═O); each occurrence of X is, independently, selected from the group consisting of RO—, R 2 C═NO—, R 2 NO— or R 2 N—, —R, and —(OSiR 2 ) t (OSiR 3 ) and with the proviso that at least one X is not —R and each occurrence of the subscript t is an integer from 0 to 50; each occurrence of the subscript a is independently an integer from 1 to 6; each occurrence of the subscript b is independently an integer from 1 to 100; each occurrence of the subscript c is independently an integer from 1 to 6; each occurrence of the subscript d is independently an integer from 1 to 100; and, each occurrence of the subscript f is independently an integer from 1 to 6, with the proviso that ab=df; which comprises reacting an aqueous solution of a salt of a thiocarboxylic acid represented by the formula: G 1 (—Y—SM) a (4) wherein: each occurrence of G 1 is independently a polyvalent alkyl, alkenyl, aryl, or aralkyl group, with each G 1 containing from 1 to 40 carbon atoms; each occurrence of M is an alkali metal, ammonium, or a mono-, di-, or tri-substituted ammonium; and each occurrence of the subscript a is independently an integer from 1 to 6; with a silane represented by the formula: L f G 2 (—SiX 3 ) c (5) wherein: each occurrence of G 2 is independently a polyvalent alkyl, alkenyl, aryl, or aralkyl group, with each G 2 containing from 1 to 40 carbon atoms; each occurrence of L is a halogen atom, sulfonate group, sulfinate group, or carboxylate group; each occurrence of X is, independently, selected from the group consisting of RO—, R 2 C═NO—, R 2 NO—,R 2 N—, —R, and —(OSiR 2 ) t (OSiR 3 ), wherein each R is, independently, selected from the group consisting of hydrogen, and alkyl, alkenyl, alkynyl, aryl, and aralkyl groups, with each R containing from 0 to 30 carbon atoms and with the proviso that at least one X is not —R and each occurrence of the subscript t is an integer from 0 to 50; each occurrence of the subscript c is independently an integer from 1 to 6; and, each occurrence of the subscript f is independently an integer from 1 to 6; and in the absence or presence of phase transfer catalyst to provide a thiocarboxylate silane.