Process for the production of solid polyisocyanates of retarded reactivity, polymer-coated, finely divided polyisocyanates and their use

US4667008A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Gerhard Grogler · Leverkusen, DE
• Richard Kopp · Cologne, DE
• Heinrich Hess · Cologne, DE

Key dates

• Filing date: May 8, 1985
• Grant date: May 19, 1987
• Expiry date: May 8, 2005

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/2991
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

This invention relates to the production of polymer-coated, finely divided polyisocyanates by mixing PA0 (A) solid, finely divided polyisocyanates (preferably dimeric diisocyanates or urea diisocyanates) with PA0 (B) polyisocyanates differing in composition from those mentioned under (A) (preferably (cyclo) aliphatic polyisocyanates, such as biuretized diisocyanates or trimers or NCO-prepolymers), in quantities of from 0.05 to 50 parts by weight, and preferably in quantities of from 0.2 to 25 parts by weight, of (B) per 100 parts by weight of (A). The solid polyisocyanate particles surface-modified by covering with polyisocyanates (B) and then reacted with PA0 (D) isocyanate-reactive compounds containing reactive hydrogen atoms or with compounds free from active hydrogen atoms which form polymers with isocyanates in sub-equivalent to substantially equivalent quantities (preferably 0.5 to 1.0 equivalent per NCO-equivalent), in the presence of PA0 (C) inert, weakly polar organic solvents, (for example aliphatic hydrocarbons or relatively long chain dialkyl ethers), plasticizers, polyols or aromatic polyamines. A polymer coating is formed by the reaction of (B) and (D) around the soli…