Liquification of diphenylmethane diisocyanate by partially reacting the isocyanate groups with blocking agents

Abstract

The present invention relates to a liquid, storage-stable isocyanate having a viscosity of less than 100,000 mPa.s at 25.degree. C. and an isocyanate content of from about 10 to 29% by weight, and is prepared by reacting a solid or semi-solid diphenylmethane diisocyanate with a blocking agent. More generally, the liquid isocyanate is prepared by reacting the solid or semi-solid diphenylmethane diisocyanate with the blocking agent in quantities such that from 7 to 55% of the isocyanate groups are blocked. Preferred blocking agents are the ketoximes, and mixtures thereof.

Dependencies are inferred from the claim text.