Liquification of trans, trans-4,4'-diisocyanate dicyclohexylmethane by partially reacting the isocyanate groups with blocking agents
US5455374A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 1993 |
| Grant date | Oct 3, 1995 |
| Priority date | — |
| Expiry date | Jun 30, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G18/80
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The present invention relates to a liquid, storage-stable isocyanate having a viscosity of less than 100,000 mPa.s at 23.degree. C. and an isocyanate content of from about 9 to 20% by weight, and is prepared by reacting a solid 4,4'-methylene bis(cyclohexyl isocyanate) with a blocking agent. The 4,4'-methylene bis(cyclohexyl isocyanate) must contain at least 35 to 100% by weight of the trans,trans isomer. More generally, this liquid isocyanate is prepared by reacting the solid or semi-solid 4,4'-methylene bis (cyclohexyl isocyanate) with the blocking agent in quantities such that at least 22% but less than 60% of the isocyanate groups are blocked. Preferred blocking agents are the ketoximes, and mixtures thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.