Catalyst and a method for the trimerization of isocyanates
View Patent ↗A method is described of preparing (poly)isocyanurate polyisocyanates by catalytic cyclotrimerization of isocyanates. A catalytic system is used which includes a cyclotrimerization catalyst based on a quatemary ammonium salt and imidazole as a cocatalyst.
1. A method of preparing polyisocyanurate polyisocyanates by catalytic cyclotrimerization of monomeric isocyanates comprising:
adding to a reaction medium comprising said isocyanates a catalytic system which comprises imidazole or one of its derivatives;
allowing the reaction to progress and for a period between 1 and 4 hours at a temperature between room temperature and 120° C.; and
isolating the product obtained thereby.
2. The method of claim 1 , wherein the imidazole is of general formula I:
in which R 1 , R 2 and R 3 are identical or different and are selected from the group consisting of H, OH, SH, a C 1 –C 4 alkyl, C 1 –C 4 hydroxyalkyl, C 1 –C 4 aminoalkyl, C 1 –C 4 alkylamino, di(C 1 –C 4 )alkylamino, C 1 –C 4 alkylthio, C 1 –C 4 haloalkyl, C 3 –C 8 cycloalkyl, C 5 –C 10 aryl, (C 5 –C 10 aryl)-C 1 –C 4 alkyl, (C 1 –C 4 alkyl)-C 5 –C 10 aryl group, a heterocyclic group where the heterocycle has 2 to 10 carbon atoms and 1 to 4 identical or different heteroatoms selected from the group consisting of O, S and N and the group NR 4 in which R 4 is C 1 –C 4 alkyl or C 3 –C 8 cycloalkyl, and n is 0, 1 or 2.
3. The method of claim 1 , wherein the imidazole is of general formula I:
in which R 1 represents hydrogen, R 2 and R 3 are identical or different and are selected from the group consisting of H, OH, SH, a C 1 –C 4 alkyl, C 1 –C 4 hydroxyalkyl, C 1 –C 4 aminoalkyl, C 1 –C 4 alkylamino, di(C 1 –C 4 )alkylamino, C 1 –C 4 alkylthio, C 1 –C 4 haloalkyl, C 3 –C 8 cycloalkyl, C 5 –C 10 aryl, (C 5 –C 10 aryl)-C 1 –C 4 alkyl, (C 1 –C 4 alkyl)-C 5 –C 10 aryl group, a heterocyclic group where the heterocycle has 2 to 10 carbon atoms and 1 to 4 identical or different heteroatoms selected from the group consisting of O, S and N and the group NR 4 in which R 4 is C 1 –C 4 alkyl or C 3 –C 8 cycloalkyl, and n is 0, 1 or 2.
4. The method of claim 1 , wherein the imidazole is of general formula I:
in which R 1 , R 2 each represents hydrogen and R 3 is selected from H, OH, SH, a C 1 –C 4 alkyl, C 1 –C 4 hydroxyalkyl, C 1 –C 4 aminoalkyl, C 1 –C 4 alkylamino, di(C 1 –C 4 )alkylamino, C 1 –C 4 alkylthio, C 1 –C 4 haloalkyl, C 3 –C 8 cycloalkyl, C 5 –C 10 aryl, (C 5 –C 10 aryl)-C 1 –C 4 alkyalkyl)-C 5 –C 10 aryl group, a heterocyclic group where the heterocycle has 2 to 10 carbon atoms and 1 to 4 identical or different heteroatoms selected from the group consisting of O, S and N and the group NR 4 in which R 4 is C 1 –C 4 alkyl or C 3 –C 8 cycloalkyl, and n is 0, 1 or 2.
5. The method of claim 1 , wherein the imidazole is of general formula I:
in which R 1 , R 2 and R 3 each represents hydrogen.
6. The method of claim 1 , wherein the amount of imidazole or derivative thereof is from 400 to 800 ppm, relative to the monomeric isocyanate.
7. The method of claim 1 , comprising the preparation of isophorone diisocyanate trimer or of a mixed isophorone diisocyanate and hexamethylene diisocyanate trimer in which the proportion of hexamethylene diisocyanate varies from 5 to 95% by weight.
8. The method of claim 1 , comprising the preparation of norbomane diisocyanate trimer or of a mixed norbornane diisocyanate and hexamethylene diisocyanate trimer in which the proportion of hexamethylene diisocyanate varies from 5 to 95% by weight.
9. The method of claim 1 , comprising the preparation of 4,4′-dicyclohexylmethanediyl diisocyanate trimer or of a mixed 4,4′-dicyclohexylmethanediyl diisocyanate and hexamethylene diisocyanate trimer in which the proportion of hexamethylene diisocyanate varies from 5 to 95% by weight.
10. A composition of polyisocyanurate polyisocyanates obtained by cyclotrimerization of isocyanates, alone or in a mixture, according to the method of claim 1 .
11. A composition of polyisocyanurate polyisocyanates wherein the composition is a product of reaction of a monomeric and/or trimeric isocyanate in the presence of imidazole or one of its derivatives, corresponding to the following general formula:
in which R 1 , R 2 and R 3 are identical or different and are selected from the group consisting of H, OH, SH, a C 1 –C 4 alkyl, C 1 –C 4 hydroxyalkyl, C 1 –C 4 aminoalkyl, C 1 –C 4 alkylamino, di(C 1 –C 4 )alkylamino, C 1 –C 4 alkylthio, C 1 –C 4 haloalkyl, C 3 –C 8 cycloalkyl, C 5 –C 10 aryl, (C 5 –C 10 aryl)-C 1 –C 4 alkyl, (C 1 –C 4 alkyl)-C 5 –C 10 aryl group, a heterocyclic group where the heterocycle has 2 to 10 carbon atoms and 1 to 4 identical or different heteroatoms selected from the group consisting of O, S and N and the group NR 4 in which R 4 is C 1 –C 4 alkyl or C 3 –C 8 cycloalkyl, and n is 0, 1 or 2.
12. The composition of claim 11 , wherein the composition is a product of reaction of a monomeric and/or trimeric isocyanate in the presence of imidazole or one of its derivatives, corresponding to the following general formula:
in which R 1 represents hydrogen, R 2 and R 3 are identical or different and are selected from the group consisting of H, OH, SH, a C 1 –C 4 alkyl, C 1 –C 4 hydroxyalkyl, C 1 –C 4 aminoalkyl, C 1 –C 4 alkylamino, di(C 1 –C 4 )alkylamino, C 1 –C 4 alkylthio, C 1 –C 4 haloalkyl, C 3 –C 8 cycloalkyl, C 5 –C 10 aryl, (C 5 –C 10 aryl)-C 1 –C 4 alkyl, (C 1 –C 4 alkyl)-C 5 –C 10 aryl group, a heterocyclic group where the heterocycle has 2 to 10 carbon atoms and 1 to 4 identical or different heteroatoms selected from the group consisting of O, S and N and the group NR 4 in which R 4 is C 1 –C 4 alkyl or C 3 –C 8 cycloalkyl, and n is 0, 1 or 2.
13. The composition of claim 11 , wherein the composition is a product of reaction of a monomeric and/or trimeric isocyanate in the presence of imidazole or one of its derivatives, corresponding to the following general formula:
in which R 1 and R 2 each represents hydrogen, R 3 is selected from the group consisting of H, OH, SH, a C 1 –C 4 alkyl, C 1 –C 4 hydroxyalkyl, C 1 –C 4 aminoalkyl, C 1 –C 4 alkylamino, di(C 1 –C 4 )alkylamino, C 1 –C 4 alkylthio, C 1 –C 4 haloalkyl, C 3 –C 8 cycloalkyl, C 5 –C 10 aryl, (C 5 –C 10 aryl)-C 1 –C 4 alkyl, (C 1 –C 4 alkyl)-C 5 –C 10 aryl group, a heterocyclic group where the heterocycle has 2 to 10 carbon atoms and 1 to 4 identical or different heteroatoms selected from the group consisting of O, S and N and the group NR 4 in which R 4 is C 1 –C 4 alkyl or C 3 –C 8 cycloalkyl, and n is 0, 1 or 2.
14. The composition of claim 11 , wherein the composition is a product of reaction of a monomeric and/or trimeric isocyanate in the presence of imidazole or one of its derivatives, corresponding to the following general formula:
in which R 1 , R 2 and R 3 each represents hydrogen.