Polyisocyanate mixtures which are liquid at greater than 5.degree. C
US5610260A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 9, 1996 |
| Grant date | Mar 11, 1997 |
| Priority date | — |
| Expiry date | Feb 9, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C275/60
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The present invention relates to polyisocyanate mixtures which are reaction products of 4,4'-diphenylmethane diisocyanate as the isocyanate component, are liquid at greater than 5.degree. C. and have an NCO content of 14.5 to 24% by weight and an allophanate group content (calculated as C.sub.2 HN.sub.2 O.sub.3, molecular weight = 101) of 7.7 to 14.5% by weight; a process for the production of these polyisocyanate mixtures by reacting 4,4'-diphenylmethane diisocyanate as the exclusive isocyanate component with one or more monohydric alcohols having 4 to 16 carbon atoms at an NCO/OH equivalent ratio of 5:1 to 8.5:1 and at a temperature of up to 160.degree. C. to form urethane groups and during or subsequent to urethane formation, converting the urethane groups to allophanate groups in the presence of a catalyst which promotes allophanate formation; and the use of these polyisocyanate mixtures as the polyisocyanate component in two-component polyurethane coating compositions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.