Process for the production of polyisocyanates containing isocyanurate groups and their use

US6765111B1 · kind B1 · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Josef Pedain · Cologne, DE
• Manfred Bock · Leverkusen, DE
• Carl-Gerd Dieris · Dormagen, DE

Key dates

• Filing date: Jan 16, 1997
• Grant date: Jul 20, 2004
• Expiry date: Jan 16, 2022

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D251/34
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The present invention is directed to a process for the production of polyisocyanates containing isocyanurate groups by trimerizing a portion of the isocyanate groups of hexamethylene diisocyanate using N,N,N-trialkyl-N-benzyl-quaternary ammonium hydroxides as the trimerization catalyst, terminating the trimerization reaction at the desired degree of trimerization by adding a catalyst poison and/or by thermally deactivating the catalyst and removing unreacted hexamethylene diisocyanate to a residual content of at most 0.2% by weight, characterized in thata) the hexamethylene diisocyanate used as starting material is freed from carbon dioxide to a residual content of less than 20 ppm (weight) andb) the catalyst is used in a quantity of less than about 0.03% by weight, based on the weight of the hexamethylene diisocyanate used.The present invention is also directed to the polyisocyanates containing isocyanurate groups obtained by this process and to their use, optionally blocked by blocking agents for isocyanate groups, as the isocyanate component for the production of polyisocyanate polyaddition products.