Preparation of isocyanato silanes

1. A process for the preparation of an alkoxysilyl group-containing isocyanate compound having the general Formula (I):

(R 1 O) 3-a R 2 a Si—R 3 —NCO  (I)

wherein

each R 1 is independently a branched or straight chain alkyl or cycloalkyl group of from 1 to 6 carbon atoms;

each R 2 is independently a branched or straight chain alkyl or cycloalkyl group of from 1 to 6 carbon atoms;

R 3 is a branched or straight chain alkylene or cycloalkylene group of from 1 to 12 carbon atoms, an arylene group of from 6 to 10 carbon atoms, or an aralkylene group of from 7 to 10 carbon atoms; and

a is 0, 1 or 2 comprising:

(i) reacting ClC(═O)Cl with a corresponding alkoxysilyl group-containing amine having the general Formula (II):

(R 1 O) 3-a R 2 a Si—R 3 —NH 2   (II)

wherein

each R 1 is independently a branched or straight chain alkyl or cycloalkyl group of from 1 to 6 carbon atoms;

each R 2 is independently a branched or straight chain alkyl or cycloalkyl group of from 1 to 6 carbon atoms;

R 3 is a branched or straight chain alkylene or cycloalkylene group of from 1 to 12 carbon atoms, an arylene group of from 6 to 10 carbon atoms, or an aralkylene group of from 7 to 10 carbon atoms; and

a is 0, 1 or 2,

in the presence of a tertiary amino-containing compound having the general Formula (II):

R 4 R 5 NR 6 O—[CH 2 CH 2 O—] x [CH 2 CH(CH 3 )O—] y [C 4 H 8 O—] z R 7 —X  (III)

wherein

each R 4 is independently a straight or branched chain alkyl, cycloalkyl, alkenyl, aryl, aralkyl or arenyl group up to 18 carbon atoms, a heterocarbon group containing from 2 to 18 carbon atoms and at least one oxygen or (—) 2 NR 8 group, wherein R 8 is a straight or branched chain alkyl, cycloalkyl, akenyl, aryl, aralkyl or arenyl group from 1 to 10 carbon atoms, or a group in which R 4 has a chemical bond with R 5 to form a cyclic structure containing the nitrogen atom;

each R 5 is independently a straight or branched chain alkyl, cycloalkyl, alkenyl, aryl, aralkyl or arenyl group up to 18 carbon atoms, a heterocarhon group containing from 2 to 18 carbon atoms and at least one oxygen or (—) 2 NR 8 group, wherein R 8 is a straight or branched chain alkyl, cycloarkyl, akenyl, aryl, aralkyl or arenyl group from 1 to 10 carbon atoms, or a group in which R 5 has a chemical bond with R 4 to form a cyclic structure containing the nitrogen atom;

R 6 is a straight or branched alkylene group of from 1 to 10 carbon atoms, a cycloalkylene or arylene group of from 5 to 10 carbon atoms, or a —R 9 C(═O)— group wherein R 9 is a straight or branched alkylene group of from 1 to 10 carbon atoms, a cycloalkylene group of from 5 to 10 carbon atoms or an arylene group of from 1 to 10 carbon atoms;

R 7 is a straight or branched alkylene group of from 1 to 10 carbon atoms, a cycloalkylene or arylene group of from 5 to 10 carbon atoms, or a —(O═C—)R 9 — group wherein R 9 is a straight or branched alkylene group of from 1 to 10 carbon atoms, a cycloalkylene group of from 5 to 10 carbon atoms or an arylene group of from 1 to 10 carbon atoms;

X is hydrogen or a —NR 4 R 5 group, wherein R 4 and R 5 have the same meanings as above;

x is 0 to 50;

y is 0 to 50; and

z is 0 to 50, with the proviso that the sum of x+y+z is from 2 to 100,

to provide for an alkoxysilyl group-containing isocyanate compound;

(ii) separating the hydrochloride salt tertiary amino-containing compound from the alkoxysilyl group-containing isocyanate compound of step (i); and optionally,

(iii) purifying the alkoxysilyl group-containing isocyanate of step (ii).

2. The process of claim 1 wherein the alkoxysilyl group-containing amine represented by the general Formula (II) is selected from the group consisting of 3-trimethoxysilylpropylamine, 3-triethoxysilylpropylainine, 3-tributoxysilylpropylamine, 3-tripropoxysilylpropylamine, 1-trimethoxysilylmethylamine, 1-dimethoxymethylsilylmethylamine, 1-diethoxymethylsilylmethylamine, 1-dimethoxymethylsilylpropylamine and 1-diethoxymethylsilylpropylamine.

3. The process of claim 2 wherein the alkoxysilyl group-containing amine represented by the general formula (II) is 3-trimethoxysilylpropylamine.

4. The process of claim 1 , wherein the tertiary amino-containing compound is selected from the group consisting of:

wherein in each of formulae (IV)-(XV):

R 1 is a straight or branched alkylene group of from 1 to 6 carbon atoms, a cycloalkylene or arylene group of 6 carbon atoms;

R 9 is a straight or branched alkylene group of from 1 to 6 carbon atoms, a cycloalkylene or an arylene group of from 6 carbon atoms;

each x and y is independently from 0 to 50, provided that the sum of x and y is from 2 to 100.

5. The process of claim 4 , wherein each x and y is independently from 0 to 10.

6. The process of claim 5 , wherein each x and y is independently from 3 to 15.

7. The process of claim 4 , wherein each R 7 and R 9 is independently selected from the group consisting of —CH 2 CH 2 —, —CH 2 CH 2 CH 2 — and —CH 2 CH(CH 3 )—.

8. The process of claim 1 wherein the tertiary a nine-containing compound of step (i) is used at a molar ratio H 2 N/Cl of from 0.4 to (16.

9. The process of claim 1 wherein the process further comprises using an inert organic solvent in step (i), step (ii), or steps (i) and (ii).

10. The process claim 9 wherein the inert solvent is selected from the group consisting of hydrocarbons, halogenated hydrocarbons, ethers, esters and combinations thereof.

11. The process of claim 1 wherein the reaction is carried out at a temperature of −50° C. to +150° C.

12. The process of claim 1 , wherein the composition of step (ii) has a chloride level of less than 1000 parts per million, based on the weight of the alkoxysilyl-containing isocyanate compound.

13. The process of claim 12 , wherein the chloride level is less than 100 parts per million, based on the weight of the alkoxysilyl-containing isocyanate compound.

14. The process of claim 1 , wherein the alkoxysilyl group-containing isocyanate compound of the general formula (I) is separated from the resulting base hydrochloride salt in step (ii) by decantation, centrifugation or filtration.

15. The process of claim 1 , wherein step (iii) is effected in order to provide a purified alkoxysilyl group-containing isocyanate.

16. The process of claim 15 , wherein the alkoxysilyl group-containing isocyanate compound of Formula (I) is purified by distillation.

17. The process of claim 16 , wherein the alkoxysilyl group-containing isocyanate compound of Formula (I) has a chloride level of less than 100 parts per million, based on the weight of the alkoxysilyl-containing isocyanate compound.

18. A composition comprising an alkoxysilyl group-containing isocyanate compound made by the process of claim 1 .

19. The composition of claim 18 , wherein the alkoxysilyl group-containing isocyanate compound is selected from the group consisting of 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, and 1-isocyanatomethyltrimethoxysilane.