Isocyanate-terminated prepolymers, a process of producing polyurethane/polyurea elastomers therefrom, and the resultant elastomers

摘要

This invention relates to isocyanate-terminated prepolymers, a process for the preparation of these isocyanate-terminated prepolymers, a process for the production of polyurethane+544 polyurea elastomers prepared from a diisocyanate comprising these prepolymers, and the elastomers produced by this process. These isocyanate-terminated prepolymers have a viscosity less than about 6000 mPa.s at 80 DEG C. and an NCO content of about 3 to 10%. These isocyanate-terminated prepolymers are the reaction product of a) an aromatic diisocyanate, b) a polyether polyol having an OH number of about 25 to 125 and containing from about 1.8 to 2.5 hydroxyl groups, and c) an aliphatic diisocyanate. The equivalent ratio of the polyether polyol to the aromatic diisocyanate is from about 1.0:0.7 to 1.0:1.1.