| 摘要 |
<p>1. Substantially linear polyester polyurethanes containing hydroxyl end groups, prepared by the reaction of a) polyester diols having a molecular weight above 600 and optionally b) diols in the molecular weight range of from 62 to 600 as chain lengthening agents with c) organic diisocyanates in proportions corresponding to an equivalent ratio of hydroxyl groups of components a) and b) to isocyanate groups of component c) in the range of from 1:0.9 to 1:0.999, characterized in that at least 80 % by weight of component a) consists of polyester diols in the molecular weight range of from 4000 to 6000 based on (i) adipic acid and (ii) mixtures of 1,4-dihydroxybutane and 1,6-dihydroxyhexane in a molar ratio of diols of from 4:1 to 1:4.</p> |
