Poly(oxy-1,4-butanediyl), .alpha.-4(or 6)-methyl-3-(1-methylpropylidene)aminooxycarbonylaminophenylaminocarbonyl-.omega.-4(or 6)-methyl-3-(1-methylpropylidene)aminooxycarbonylaminophenylaminocarbonyloxy-

Poly(oxy-1,4-butanediyl), α-[[[4(or 6)-methyl-3-[[[[(1-methylpropylidene) amino]oxy]carbonyl]amino]phenyl]amino ]carbonyl]-ω-[[[[4(or 6)-methyl-3-[[[[(1-methylpropylidene) amino]oxy]carbonyl]amino]phenyl]amino ]carbonyl]oxy]-