Process for the production of polyisocyanates
US3952042A · kind A · utility
11Cited by
2References
2Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Nov 11, 1974 |
| Grant date | Apr 20, 1976 |
| Priority date | — |
| Expiry date | Nov 11, 1994 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G18/7664
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process is provided for making a mixture of diisocyanate and polyisocyanates having more than two amino groups of the diphenylmethane series which has a low content of the o-isomers wherein a mixture of aniline and a polyamine prepared by condensation of aniline and formaldehyde is condensed with formaldehyde, at least 90% of the amino groups in the mixture being protonized with an acid, and phosgenating the resulting condensation product to form corresponding polyisocyanates.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.