Stable liquid carbodiimide-containing polyisocyanate compositions
US4199524A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 1978 |
| Grant date | Apr 22, 1980 |
| Priority date | — |
| Expiry date | Oct 30, 1998 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G18/725
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Highly stable liquid 4,4'-diphenylmethane diisocyanate (MDI) containing MDI-carbodiimide adducts are prepared by heating MDI at a temperature of from 180.degree. C. to 250.degree. C. for a period of from one hour to ten hours in the presence of tris(chloromethyl)phosphine oxide and thereafter equilibrating the adduct formation. Equilibration can occur by any of several methods, i.e., by cooling the composition to a temperature of from 60.degree. C. to 90.degree. C. within twenty minutes, maintaining the composition at this temperature for a period of from one hour to four hours and thereafter cooling the composition to room temperature or by cooling the composition to a temperature less than 100.degree. C. within twenty minutes, further cooling to room temperature, and maintaining the composition at room temperature for one week to two weeks. The resulting compositions have very low sediment contents and are particularly useful in the preparation of microcellular polyurethane foams.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.