Compositions comprising alkoxysilane-containing isocyanates and acid stabilisers

1. A composition comprising

A) an isocyanate of formula (I)

OCN-A-SiR 1 R 2 R 3   (I),

wherein A is a straight-chain, branched, substituted and/or unsubstituted aliphatic hydrocarbyl of 1 to 12 carbon atoms or substituted or unsubstituted cycloaliphatic hydrocarbyl of 4 to 18 carbon atoms,

wherein R 1 has a formula —O—R alk ,

wherein R 2 and R 3 are each independently selected from the group of substituents consisting of —R alk and —O—R alk , and

wherein —R alk is a hydrocarbyl of 1 to 6 carbon atoms, and

B) a Bronstedt or Lewis acid or a compound which releases a Bronstedt or Lewis acid at room temperature selected from the group consisting of a carboxylic acid, a mineral acid, an acyl halide, an alkyl halide, an aryl halide and a mixture thereof

wherein the Bronstedt or Lewis acid or the compound which releases a Bronstedt or Lewis acid at room temperature is present in an amount of 0.0001 to 1 per cent by weight of the mass of the isocyanate in the composition.

2. The composition according to claim 1 , wherein the Bronstedt or Lewis acid or the compound which releases a Bronstedt or Lewis acid at room temperature is an aryl halide a compound of formula (II)

wherein R 5 is selected from the group consisting of halogen, —CO-halogen and —CH 2 -halogen, and R 6 is selected from the group consisting of hydrogen, —CH 2 -halogen, halogen and —CO-halogen.

3. The composition according to claim 1 , wherein the isocyanate has a formula OCN—(CH 2 ) n —Si(OR 7 ) 3 wherein n is 1 to 12 and R 7 is either methyl or ethyl.

4. The composition according to claim 1 , further comprising

C) a compound having one or more NCO-reactive hydroxyl, thiol, —NH—, carbon-acid and/or amine groups.

5. The composition according to claim 4 , wherein a stoichiometric ratio between a totality of NCO-reactive hydroxyl, thiol, NH, carbon-acid and/or amine groups of C) to a totality of NCO groups of A) is 2:1 to 1:2.

6. A process for preparing a polymer, comprising curing the composition according to claim 4 .

7. A process for preparing a stabilized alkoxysilane-containing isocyanate, comprising

e) adding a Lewis or Bronstedt acid or a compound which releases a Bronstedt or Lewis acid at room temperature to an alkoxysilane-containing isocyanate,

wherein the Bronstedt or Lewis acid or the compound which releases a Bronstedt or Lewis acid at room temperature is present in an amount of 0.0001 to 1 per cent by weight of the sum of the acid and isocyanate.

8. A process for preparing a stabilized alkoxysilane-containing isocyanate, comprising

a1) reacting an alkoxysilanealkylamine of formula (III)

H 2 N-A-SiR 1 R 2 R 3   (III)

with urea to form a (cyclo) alkylenebisurea of formula (IV)

H 2 N—OC—NH-A-SiR 1 R 2 R 3   (IV),

b1) reacting the (cyclo)alkylenebisurea of formula (IV) from a) with an alcohol of formula R 8 —OH to form a carbamate of formula (V)

R 8 O—OC—NH-A-SiR 1 R 2 R 3   (V)

or

a2) reacting an alkoxysilanealkylamine of formula (III)

H 2 N-A-SiR 1 R 2 R 3   (III)

with urea in the presence of an alcohol of formula R 8 —OH to form a carbamate of formula (V)

R 8 O—OC—NH-A-SiR 1 R 2 R 3   (V),

and also additionally to the combination of a1) and b1) or additionally to a2)

c) removing the alcohol of formula R 8 —OH after b1) or a2) to form a reaction mixture separated from the alcohol, and

d) thermally cracking the reaction mixture separated from the alcohol, at a temperature of 180 to 280° C. at a pressure of 0.1 to 200 mbar,

wherein A is a straight-chain, branched, substituted and/or unsubstituted aliphatic hydrocarbyl of 1 to 12 carbon atoms or substituted or unsubstituted cycloaliphatic hydrocarbyl of 4 to 18 carbon atoms,

wherein R 1 has a formula —O—R alk ,

wherein R 2 and R 3 are each independently selected from the group of substituents consisting of —R alk , and —O—R alk ,

wherein —R alk is hydrocarbyl of 1 to 6 carbon atoms, and

wherein R 8 is a substituted or unsubstituted alkyl, cycloalkyl, aryl or aralkyl; and

e) adding a Lewis or Bronstedt acid or a compound which releases a Bronstedt or Lewis acid at room temperature to an alkoxysilane-containing isocyanate.

9. The process according to claim 7 , wherein the Bronstedt or Lewis acid or the compound which releases a Bronstedt or Lewis acid at room temperature is selected from the group consisting of a carboxylic acid, a mineral acid, an acyl halide, an alkyl halide, and an aryl halide.

10. The process according to claim 7 , wherein the isocyanate has a formula OCN—(CH 2 ) n —Si(OMe) 3 wherein n is from 1 to 12.

11. The process according to claim 8 , wherein b1) or a) are carried out in a pressure distillation reactor with removal of resultant ammonia.

12. A composition consisting essentially of

A) an isocyanate of formula (I)

OCN-A-SiR 1 R 2 R 3   (I),

wherein A is a straight-chain, branched, substituted and/or unsubstituted aliphatic hydrocarbyl of 1 in 12 carbon atoms or substituted or unsubstituted cycloaliphatic hydrocarbyl of 4 to 18 carbon atoms,

wherein R 1 has a formula —O—R alk ,

wherein R 2 and R 3 are each independently selected from the group of substituents consisting of —R alk and —O—R alk , and

wherein —R alk is a hydrocarbyl of 1 to 6 carbon atoms, and

B) a Bronstedt or Lewis acid or a compound which releases a Bronstedt or Lewis acid at room temperature which is selected from the group consisting of a carboxylic acid, a mineral acid, an acyl halide, an alkyl halide, an aryl halide and a mixture thereof.