Method for catalytic dimerization of isocyanates
US7297752B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 20, 2001 |
| Grant date | Nov 20, 2007 |
| Priority date | — |
| Expiry date | Apr 16, 2022 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G18/027
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The invention concerns a method for preparing polyisocyanates by cyclodimerization of isocyanate functions borne by initial monomer isocyanates. The invention is characterised in that it comprises steps which consist in: a) providing a reaction medium comprising initial monomer isocyanates, optionally in the presence of a solvent; b) adding to said reaction mixture a (cyclo)dimerization catalyst comprising a compound of the family of super acids; c) heating the reaction medium to a temperature ranging between 0° C. and 300° C., advantageously between 20° C. and 200° C. until the desired rate of transformation is obtained; d) optionally inactivating or eliminating the reaction catalyst; and e) optionally eliminating the unreacted monomer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.