The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 10, 1981
Filed:
May. 04, 1979
Hans-Jurgen Muller, Cologne, DE;
Rudolf Hombach, Cologne, DE;
Manfred Dollhausen, Odenthal, DE;
Joachim Zirner, Leverkusen, DE;
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
The instant invention is directed to a process for the production of isocyanate polyisocyanates containing at least 50%, by weight, of tris-isocyanatomonoisocyanurates and at most 3%, by weight, of isocyanurate-free diisocyanate. The process comprises catalytically trimerizing the organic diisocyanates free from isocyanurate groups and terminating the trimerization reaction by deactivation of the catalyst after 5 to 40% of the isocyanate groups of the isocyanurate-free diisocyanate have been trimerized. The unreacted isocyanurate-free diisocyanate is then distilled off in the presence of from 1 to 30%, by weight, based on the end product obtained as distillation residue, of an inert liquid distillation aid which boils at a temperature at least 50.degree. C. above the boiling point of the isocyanurate-free diisocyanate. The invention is also directed to the products produced by this process.