Cold impact resistant urethane foam
US4102833A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 16, 1977 |
| Grant date | Jul 25, 1978 |
| Priority date | — |
| Expiry date | Mar 16, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S264/83
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A quasi-prepolymer-type urethane foam for a reaction injection molding (RIM) system comprises, for the polyol side, a blend of a long-chain polyol with a short-chain diol and/or triol and an organometallic catalyst and, for the prepolymer side, a unique high--27 to 31% --free NCO quasi-prepolymer made by reacting an essentially pure MDI with a selected low molecular weight (240 to 1500) polyol having a functionality of about 2.7 to 3.3. The selected low molecular weight polyol is specifically a polyether polyol (i.e. a polyoxpropylene and/or ethylene polyol) initiated with TMP, hexanetriol, glycerine or other suitable polyol. The quasi-prepolymer, while having the expected high reactivity, surprisingly gives good rapid cures in less than 2 minutes. The resulting urethane foam is characterized by its excellent low temperature properties, especially -20% F cold flexibility and -20% F dart impact. The quasi-prepolymer storage stability can be greatly improved by the inclusion of a small amount of a liquid MDI.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.