Thioallophanate polyisocyanates containing silane groups
The invention relates to thioallophanates which contain silane groups and are of the general formula (I) in which R 1 , R 2 and R 3 are identical or different radicals and are each a saturated or unsaturated, linear or branched, aliphatic or cycloaliphatic radical or an optionally substituted aromatic or araliphatic radical having up to 18 carbon atoms, where said radical may optionally contain up to 3 heteroatoms from the group of oxygen, sulphur and nitrogen, X is a linear or branched organic radical having at least 2 carbon atoms, Y is a linear or branched, aliphatic or cycloaliphatic radical or an araliphatic or aromatic radical having up to 18 carbon atoms, and n is an integer from 1 to 20, to a process for preparation thereof, and to the use thereof as starting components in the production of polyurethane plastics.
1. A polyurethane plastic reaction product from a thioallophanate comprising silane groups, of the formula (I)
wherein,
R 1 , R 2 and R 3 are identical or different radicals and are each a saturated or unsaturated, linear or branched, aliphatic or cycloaliphatic or an optionally substituted aromatic or araliphatic radical having up to 18 carbon atoms, which may optionally contain up to 3 heteroatoms from the series of oxygen, sulfur and nitrogen,
X is a linear or branched organic radical having at least 2 carbon atoms,
Y is a linear or branched, aliphatic or cycloaliphatic, an araliphatic or aromatic radical having up to 18 carbon atoms, and
n is an integer from 1 to 20.
2. The polyurethane plastic reaction product from a thioallophanate according to claim 1 , wherein in formula (I),
R 1 , R 2 and R 3 are identical or different radicals and are each a saturated, linear or branched, aliphatic or cycloaliphatic radical having up to 6 carbon atoms, and may optionally contain up to 3 oxygen atoms, and
X is a linear or branched alkylene radical having 2 to 10 carbon atoms.
3. The polyurethane plastic reaction product from a thioallophanate according to claim 1 , wherein in formula (I),
R 1 , R 2 and R 3 are each alkyl radicals having up to 6 carbon atoms and/or alkoxy radicals which contain up to 3 oxygen atoms, with the proviso that at least one of the radicals R 1 , R 2 and R 3 is an alkoxy radical, and
X is a propylene radical (—CH 2 —CH 2 —CH 2 —).
4. The polyurethane plastic reaction product from a thioallophanate ophanate according to claim 1 , wherein in formula (I),
R 1 , R 2 and R 3 are identical or different radicals and are each methyl, methoxy or ethoxy, with the proviso that at least one of the radicals R 1 , R 2 and R 3 is a methoxy or ethoxy radical, and
X is a propylene radical (—CH 2 —CH 2 —CH 2 —).
5. The polyurethane plastic reaction product from a thioallophanate ophanate according to claim 1 , wherein in formula (I),
Y is a linear or branched, aliphatic or cycloaliphatic radical having 5 to 13 carbon atoms.
6. The polyurethane plastic reaction product from a thioallophanate ophanate according to claim 1 , wherein in formula (I),
Y is an aliphatic and/or cycloaliphatic radical obtained by removing the isocyanate groups from a diisocyanate selected from the group consisting of 1,5-diisocyanatopentane, 1,6-diisocyanatohexane, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane, 2,4′- and 4,4′-diisocyanatodicyclohexylmethane.
7. A process for preparing a thioallophanate by reacting
A) at least one monomeric diisocyanate of the formula (II)
OCN—Y—NCO (II),
in which Y is a linear or branched, aliphatic or cycloaliphatic, an araliphatic or aromatic radical having up to 18 carbon atoms, with
B) a mercaptosilane of the formula (III)
wherein,
R 1 , R 2 and R 3 are identical or different radicals and are each a saturated or unsaturated, linear or branched, aliphatic or cycloaliphatic or an optionally substituted aromatic or araliphatic radical having up to 18 carbon atoms, which may optionally contain up to 3 heteroatoms from the series of oxygen, sulfur and nitrogen,
X is a linear or branched organic radical having at least 2 carbon atoms,
Y is a linear or branched, aliphatic or cycloaliphatic, an araliphatic or aromatic radical having up to 18 carbon atoms, and
n is an integer from 1 to 20,
in an equivalent ratio of isocyanate groups to mercapto groups of 2: 1 to 40: 1,
wherein the reaction is carried out in the presence of a catalyst selected from the group consisting of zinc carboxylates and zirconium carboxylates.
8. The process according to claim 7 , wherein component A) comprises the diisocyanate of the formula (II) in which Y is a linear or branched, aliphatic or cycloaliphatic radical having 5 to 13 carbon atoms.
9. The process according to claim 7 , wherein component A) is selected from the group consisting of 1,5-diisocyanatopentane, 1,6-diisocyanatohexane, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane, 2,4′- and/or 4,4′-diisocyanatodicyclohexylmethane or any desired mixtures thereof.
10. The process according to claim 7 , wherein component B) comprises the mercaptosilane of the formula (III)
wherein
R 1 , R 2 and R 3 are identical or different radicals and are each a saturated, linear or branched, aliphatic or cycloaliphatic radical having up to 6 carbon atoms, and may optionally contain up to 3 oxygen atoms, and
X is a linear or branched alkylene radical having 2 to 10 carbon atoms,
or any desired mixtures thereof.
11. The process according to claim 7 , wherein component B) comprises the mercaptosilane of the formula (III)
wherein
R 1 , R 2 and R 3 are each alkyl radicals having up to 6 carbon atoms and/or alkoxy radicals which contain up to 3 oxygen atoms, with the proviso that at least one of the radicals R 1 , R 2 and R 3 is an alkoxy radical, and
X is a propylene radical (—CH 2 —CH 2 —CH 2 —),
or any desired mixtures thereof.
12. The process according to claim 7 , wherein component B) comprises the mercaptosilane of the formula (III)
wherein
R 1 , R 2 and R 3 are identical or different radicals and are each methyl, methoxy or ethoxy, with the proviso that at least one of the radicals R1, R2 and R3 is a methoxy or ethoxy radical, and
X is a propylene radical (—CH 2 —CH 2 —CH 2 —),
or any desired mixtures of such mercaptosilanes.
13. A polyurethane or polyurea paint or coating composition comprising a reaction product from thioallophanate comprising silane groups, of the formula (I)
wherein,
R 1 , R 2 and R 3 are identical or different radicals and are each a saturated or unsaturated, linear or branched, aliphatic or cycloaliphatic or an optionally substituted aromatic or araliphatic radical having up to 18 carbon atoms, which may optionally contain up to 3 heteroatoms from the series of oxygen, sulfur and nitrogen,
X is a linear or branched organic radical having at least 2 carbon atoms,
Y is a linear or branched, aliphatic or cycloaliphatic, an araliphatic or aromatic radical having up to 18 carbon atoms, and
n is an integer from 1 to 20.
14. A substrate coated with the polyurethane or polyurea paint or coating composition according to claim 13 .