1,4-Butanediol, polymer with 1,3-diisocyanatomethylbenzene and .alpha.-hydro-.omega.-hydroxypoly(oxy-1,4-butanediyl) Poly tetramethylene ether glycol polymer with 1,4 butanediol and 1,3-diisocyanatemethylbenzene; 1,4-Butanediol, polymer with 1,3-diisocyanatomethylbenzene and 伪-hydro-��-hydroxypoly( oxy-1,4-butanediyl)