Thermoplastic polyurethanes and a two-stage process for their preparation

US3963656A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Ernst Meisert · Leverkusen, DE
• Wilhelm Goyert · Leverkusen, DE

Key dates

• Filing date: Jan 31, 1975
• Grant date: Jun 15, 1976
• Expiry date: Jan 31, 1995

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G18/10
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Polyurethane elastomers suitable for coating textiles, leather, paper and similar substrate and a multi-stage process for their production. The polyurethane elastomers are obtained from PA1 A. a polyol with an average molecular weight between 900 and 5300, PA1 B. 4,4'-diisocyanatodiphenylmethane and PA1 C. a diol with a molecular weight below 500, characterized in that the equivalent ratio ((b)/(a)+(c)) is between 0.87 and 1 and in that (a) contains at least 40% by weight of a polyurethane of the formula ##EQU1## where R is a divalent group such as can be obtained by removing the hydroxyl groups from a diol which has a molecular weight of between 700 and 1750, and PA1 Q is a divalent aliphatic, cycloaliphatic, araliphatic or aromatic group which contains 2 to 20, and preferably, 4 to 15, carbon atoms; but Q is not ##SPC1##