THERMOPLASTIC POLYURETHANES FROM POLYOL BLENDS

• Main Authors: OERTEL, RICHARD W., III, EHRLICH, BENJAMIN S
• Format: Patent
• Language: English; French
• Published: 23.10.1984
• Edition: 7
• 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

Thermoplastic polyurethane elastomers are disclosed which have flexural moduli of at least about 9,000 psi at ambient temperature and which are characterized by improved low temperature impact strength over prior art polyurethane elastomers with comparable physical properties. The subject elastomers are the reaction product of A. 4,4'-methylenebis(phenylisocyanate); B. a polyol component comprised of (1) about 40 to about 85 weight percent of a diol selected from (a) a particular polyoxypropylene-polyoxyothylene copolymer of 1000 to 3000 MW and having a particular primary hydroxyl content and ethylene oxide residue content, or (b) a 1000 to 4000 MW polyester diol, or mixtures of (a) and (b); and (2) about 15 to 60 weight percent of a polyoxypropylene-polyoxy-ethylene diol of triol having a 3500 to 7000 MW and an ethylene oxide content of at least 10 percent by weight with the maximum content governed by the diol or triol molecular weight; and C. a difunctional extender, wherein the equivalent proportions of said polyol component (a) to said extender (C) fall within the range of about 1:4 to about 1:20 and the NCO to OH equivalents are within the range of about 0.99:1 to 1.06:1. The elastomers find particular utility in the manufacture of ski boots, hockey boots and automotive exterior panels, bumpers, fascia, and the like.