Process for the preparation of aromatic polyisocyanates containing urea and/or biuret groups

US4618706A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Hans-Joachim Scholl · Cologne, DE
• Hans Hettel · Cologne, DE

Key dates

• Filing date: Apr 2, 1982
• Grant date: Oct 21, 1986
• Expiry date: Apr 2, 2002

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G18/8038
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

This invention relates to a process for the preparation of aromatic polyisocyanates containing urea and/or biuret groups, optionally in the form of a mixture of homologues and/or isomers, by the reaction of aromatic diisocyanates with diamines having primary or secondary amino groups at about 20.degree. to 180.degree. C., and at an equivalent ratio of isocyanate groups to amino groups in the range of 5:1 to 100:1, at least 25 mol percent of the diisocyanates put into the process and/or at least 25 mol percent of the diamines put into the process being alkyl-phenylene diisocyanates or, respectively, alkyl-phenylene diamines, in which the alkyl substituents have 6 to 18 carbon atoms, and the use of the products of the process, optionally as solutions in excess starting diisocyanate, as isocyanate components in the production of polyurethanes.