Thermoplastic polyurethanes and a two-stage process for their preparation

• Main Authors: GOYERT; WILHELM, MEISERT; ERNST
• Format: Patent
• Language: English
• Published: 15.06.1976
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP

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 A. A POLYOL WITH AN AVERAGE MOLECULAR WEIGHT BETWEEN 900 AND 5300, B. 4,4'-DIISOCYANATODIPHENYLMETHANE AND 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 HO-R-O-C-NH-Q-NH-C-O-R-OH PARALLEL PARALLEL OO 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 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