Process for preparing polyurethane elastomer from a soft-segment isocyanate-terminated prepolymer
US5418259A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jan 27, 1994 |
| Grant date | May 23, 1995 |
| Priority date | — |
| Expiry date | Jan 27, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G2120/00
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
This invention relates to a process of preparing polyurethane polymers by reaction of an isocyanate composition having an isocyanate equivalent weight of from 180 to 300 and comprising in from at least 50 weight percent a prepolymer, with an active hydrogen-containing substance in the presence of water which provides for at least 50 mole percent of the total blowing requirement. The prepolymer is obtained by reacting a molar excess of a polyisocyanate comprising, in from at least 70 weight percent, 4,4'-methylene diphenylisocyanate with an isocyanate-reactive composition containing (a) a branched diol or triol having a molecular weight of from 60 to 300, and (b) a polyoxyalkylene polyol or mixtures thereof having an average functionality of from 2 to 4 and a molecular weight of from 3000 to 12000, wherein the parts by weight ratio of (a):(b) is from 0.01:1 to 0.25:1.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.