Polyurethane resin with a wide elastomeric range for fibres prodn.

摘要

A polyurethane resin with a mean mol. wt. of 30,000-500,000 and a wide elastomeric range contains repeating units (A) and (B) of formula (I) and (II) respectively, in a random sequence and with a ratio of A/B = 0.1-2.0: -CONH-X-NHCOO-Y-O- (I) -CONH-X-NHCOO-Z-O- (II) X = residue of p-phenylene di-isocyanate, 2,4- or 2,6-TDI, 4,4'-diphenylmethanediisocyanate, 1,5-naphthalenediisocyanate or 3,3'-dimethyldiphenyl-4,4'-di-isocyanate; Y = residue of a poly(alkylene-ether)-diol with a mol. wt. of 500-10,000, contg. gps. of formula: -(CH2)4O- and -CHR1CHR2CHR3CHR4O- in the main chain (with one of the R gps. = lower alkyl, and the others = H); and Z = residue obtd. by removing OH gps. from 3,9-bis-(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxa spiro5.5undecane (= spiro-diol). Also claimed is a process for the prodn. of (I) (see below).