Method of forming storage-stable polyurethane prepolymers
US4145515A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 1, 1976 |
| Grant date | Mar 20, 1979 |
| Priority date | — |
| Expiry date | Dec 1, 1996 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G18/10
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Methods of forming liquid, low viscosity, low molecular weight, cross-linkable, stable polyurethane prepolymers which comprise: reacting polyisocyanates, and preferably aliphatic and cycloaliphatic diisocyanates, with polyhydroxy compounds or polyols, and preferably diols, triols, tetrols, and mixtures thereof; the polyols having a molecular weight of from about 62 to about 3000; the polyisocyanates and the polyols being added to the reaction mixture in an NCO/OH ratio in the range of from about 0.7:1 to about 6:1, and preferably from about 1.6:1 to about 4:1; the reaction taking place preferably in an inert, non-reactive organic solvent such as xylene; in the absence of any reaction catalysts, or in the presence of a relatively very low concentration of reaction catalysts of from about 0.00005% by weight to about 0.8% by weight, based on the total weight of the reaction mixture; at a reaction temperature of from about 0.degree. C. to about 70.degree. C., and preferably from about 0.degree. C. to about 40.degree. C., for a reaction time of from about 1/2 hour to about 12 hours; and terminating the reaction short of completion at a percent completion of reaction of from about 2% to …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.