Carbodiimide-modified polymethylene polyphenylene polyisocyanates for use in the preparation of polyisocyanurate-polyurethane foams
US4424288A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 24, 1981 |
| Grant date | Jan 3, 1984 |
| Priority date | — |
| Expiry date | Dec 24, 2001 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S521/902
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Liquid carbodiimide-modified organic polyisocyanates are prepared by reacting a crude polymethylene polyphenylene polyisocyanate containing no more than 70 weight percent diphenylmethane diisocyanate with an isomer mixture of 40 to 100 weight percent 4,4'-, 0 to 50 weight percent 2,4- and 0 to 10 weight percent 2,2'-diphenylmethane diisocyanate and having an average functionality of 2.1 to 2.7 and a free NCO content of at least 30 percent weight percent in the presence of an effective amount of carbodimidization catalyst. Polyisocyanurate-polyurethane foams prepared by reacting the modified polyisocyanates and polyols selected from the group consisting of diethylene glycol and ethylene oxide adducts of trimethylolpropane, trimethylolethane, glycerine, pentaerythritol, .alpha.-methylglucoside, sucrose, toluene diamine and methylene dianiline in the presence of trimerization catalysts exhibit improved compression strengths and K-factors with low friability and smoke density.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.