Process for the preparation of (mercaptoorganyl)alkoxysilanes

1. A process for the preparation of(mercaptoorganyl)alkoxysilanes, comprising reacting an alkali metal sulfide with a mixture of (haloorganyl)alkoxysilane and (haloorganyl)-halosilane in an alcohol with the exclusion of air and at elevated pressure.

2. The process of claim 1 , wherein a (mercaptoorganyl)alkoxysilane compound is produced of the general formula I:

wherein the substituents R are identical or different and are selected from the group consisting of: C 1 –C 8 alkyl; C 2 –C 12 alkenyl; C 6 –C 10 aryl; C 7 –C 16 aralkyl; or OR′, wherein the substituents R′ are identical or different and are selected from the group consisting of: a C 1 –C 24 branched or unbranched monovalent alkyl or alkenyl group; an C 6 –C 10 aryl group; and an C 7 –C 16 aralkyl group;

R″ is a branched or unbranched, saturated or unsaturated, aliphatic, aromatic or mixed aliphatic/aromatic divalent C 1 –C 30 hydrocarbon group which is optionally substituted by F, Cl, Br, I, NH 2 or NHR′; and

x is 1–3.

3. The process of claim 1 , wherein said (haloorganyl)alkoxysilane compounds are of the general formula II:

wherein the substituents R are identical or different and are selected from the group consisting of: C 1 –C 8 alkyl; C 2 –C 12 alkenyl; C 6 –C 10 aryl; C 7 –C 16 aralkyl; or OR′, wherein the substituents R′ are identical or different and are selected from the group consisting of: a C 1 –C 24 branched or unbranched monovalent alkyl or alkenyl group; an C 6 –C 10 aryl group; and an C 7 –C 16 aralkyl group;

R″ is a branched or unbranched, saturated or unsaturated, aliphatic, aromatic or mixed aliphatic/aromatic divalent C 1 –C 30 hydrocarbon group which is optionally substituted by F, Cl, Br, I, NH 2 or NHR′;

x is 1–3; and

Hal is chlorine, bromine, fluorine or iodine.

4. The process of claim 1 , wherein said (haloorganyl)halosilane compounds are of the general formula III:

wherein R″ is a branched or unbranched, saturated or unsaturated, aliphatic, aromatic or mixed aliphatic aromatic divalent C 1 –C 30 hydrodarbon group which is optionally substituted by F, Cl, Br, I, NH 2 , or NHR′, wherein the substituent R′ is selected from the group consisting of: a C 1 –C 24 branched or unbranched monovalent alkyl or alkenyl group; an aryl group and an aralkyl group,

x is 1–3; and

Hal is chlorine, bromine, fluorine or iodine; and

the substituents R″′ are identical or different and are selected from the group consisting of: F; Cl; Br; I; C 1 –C 8 alkyl; C 2 –C 12 alkenyl; C 6 –C 10 aryl; C 7 –C 16 aralkyl; and OR′, wherein the substituent R′ is selected from the group consisting of: a C 1 –C 24 branched or unbranched monovalent alkyl or alkenyl group; an C 6 –C 10 aryl group; and an C 7 –C 16 aralkyl group.

5. The process of claim 1 , wherein the molar ratio of(haloorganyl)alkoxysilane to (haloorganyl)halosilane is from 0.001:1 to 2:1.

6. The process of claim 1 wherein the molar ratio of hydrolysable Si-halogen functions in the mixture of (haloorganyl)alkoxysilane and (haloorganyl)halosilane to alkali metal sulfide is from 1:0.51 to 1:1.2.

7. The process of claim 1 , wherein said alkali metal sulfide is selected from the group consisting of: dilithium sulfide (Li 2 S); disodium sulfide (Na 2 S); and dipotassium sulfide (K 2 S).

8. The process of claim 1 , wherein said alcohol is a primary, secondary, tertiary alcohol having from 1 to 24 carbon atoms.

9. The process of claim 1 , further comprising the addition of polar, protic, aprotic, basic or acidic additives to the reaction mixture at the beginning of the reaction and/or during the reaction and/or at the end of the reaction.

10. The process of claim 1 , wherein said process is carried out at a temperature of from 0 to 180° C.