Isocyanate prepolymers, a process for their preparation and their use

US5574124A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Lutz Schmalstieg · Neunburg vorm Wald, DE
• Rainer Rettig · Amagasaki, JP
• Ulrich Walter · Langenfeld, DE
• Edwin R. Hortelano · Dorpsstraat, US

Key dates

• Filing date: Aug 3, 1995
• Grant date: Nov 12, 1996
• Expiry date: Aug 3, 2015

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G2190/00
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Isocyanate prepolymers having an NCO content of 1.5 to 5.0 wt. % and a monomeric diisocyanate content of less than 0.5 wt. % which are the reaction products of PA1 A) aromatic or cycloaliphatic diisocyanates with PA1 B) mixtures of PA2 B1) polyether polyols having a molecular weight of 1000 to 3000 and PA2 B2) polyester carbonate diols having a molecular weight of 700 to 3000, PA1 wherein components B1) and B2) are present in a weight ratio of 0.25:1 to 1.5:1; a process for the preparation of these isocyanate prepolymers by reacting the preceding starting materials at an NCO/OH equivalent ratio of at least 1.5:1 and optionally with subsequent removing unreacted monomeric diisocyanate by distillation; and the use of these isocyanate prepolymers as binders for sealing or coating compositions.