Process for the production of polyisocyanates with biuret structures

US4837359A · kind A · utility

Assignees

• BAYER HEALTHCARE LLC · DE
• Mobay Corporation · US

Inventors

• Helmut Woynar · Dormagen, DE
• Klaus Konig · Leverkusen, DE
• Josef Pedain · Cologne, DE
• William E. Slack · Moundsville, US

Key dates

• Filing date: Dec 30, 1987
• Grant date: Jun 6, 1989
• Expiry date: Dec 30, 2007

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G18/7831
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Polyisocyanates with biuret structures are produced at temperatures above 250.degree. C. More specifically, an excess of a diisocyanate having aliphatically and/or cycloaliphatically bound isocyanate groups is reacted with a diamine containing aliphatically and/or cycloaliphatically bound amino groups at temperatures above 250.degree. C. for relatively brief periods of time. Water and/or polyvalent alcohols may optionally be included in the reaction mixture. The polyisocyanates with biuret structures produced by this process are characterized by good color, good dilutability with covalent solvents and comparatively low viscosity.