Patent ID: 7824288

Claim:
A power transmission belt comprising a main belt body portion of elastomeric material, a tensile reinforcement disposed in said body portion, and a sheave contact portion integral with said main body portion, said elastomeric material comprising the reaction product of: (A) a polyisocyanate prepolymer composition prepared by reacting (i) a diisocyanate selected from the group consisting of (a) para-phenylene diisocyanate, (b) 2,6-toluene diisocyanate, and (c) a cycloaliphatic diisocyanates with trans or trans, trans geometric structure; (ii) a polyol substantially free of moieties oxidative at less than about 150° C. and selected from the group consisting of (a) polycarbonate polyols, (b) polyester polyols, and (c) mixtures of said polycarbonate polyols and said polyester polyols; and (iii) a triol crosslinker selected from said polyols; and adding there to (iv) a plasticizer selected from the group consisting of alkyl-ether di-alkylesters, polyalkyl-ether di-alkylesters, and polyethylene glycol di-alkylesters; and (B) a chain extender selected from the group consisting of (a) aromatic symmetric primary diamine chain extenders, (b) mixtures of said aromatic symmetric primary diamine chain extenders and aromatic secondary diamine chain extenders, and (c) mixtures of one or more of said aromatic symmetric primary diamine chain extenders and said polyols.