Thermoplastic polyurethane prepared from a poly-1,2-propylene ether glycol, a low molecular weight glycol and 2,4-tolylene diisocyanate

Claim 1

A thermoplastic, linear and segmented poly- 1,2-propylene ether urethane consisting essentially of the reaction product of (1) tolylene diisocyanate comprising from about 55% to 100% by weight of 2,4-tolylene diisocyanate and the balance 2,6-tolylene diisocyanate, (2) a glycol selected from the group consisting of ethylene glycol, 2,3-butane diol and neopentyl glycol and mixtures thereof and (3) a poly-1,2-propylene ether glycol having an average molecular weight of from 3,300 to 14,000, the equivalent ratio of the diisocyanate to the glycols being from about 0.98 to 1.08:1, the weight ratio of the urethane segments (tolylene diisocyanate plus ethylene glycol, 2,3-butane diol and/or neopentyl glycol) to poly-1,2-propylene ether segments being from about 0.4:1.0 to 1.5:1.0, the glass transition temperature of the poly-1,2-propylene ether segments of the polyurethane being below about -30° C., the poly-1,2-propylene ether glycol having been made by the reaction of propylene oxide with a low molecular weight aliphatic glycol using a polymerization catalyst of the double metal cyanide complex class and the polyurethane having a 100% modulus of at least about 400 p.s.i.