| 摘要 |
A process for the production of polyester urethanes which are stable in the molten state and can be melt spun, comprises condensing at above 100 DEG C. in an aromatic chlorinated solvent having a B.P. of 120-200 DEG C. a mixture of: (a) 1 molecular proportion of at least one polyester having terminal hydroxyl groups and of M.W. 1200-5000 obtained by condensation of at least one aliphatic dicarboxylic acid having 4-12 C with at least one diol having 2-10 C, (b) 2-4 molecular proportions of at least one diol in which the hydroxyl groups are primary and which has more than 3 C, and optionally (c) at most 0.5 molecular proportions of at least one triol in which the hydroxyl groups are primary and/or secondary and which is soluble at elevated temperatures in the mixture of (a) and (b) with the solvent with (d) an aliphatic diisocyanate in amount such that the number of -NCO groups is equivalent to the number of hydroxyl groups in the mixture of (a) + (b) + (c), and separating the polyurethane from the solvent. Solvents may be chlorobenzene or o-dichlorobenzene. In a typical Example (1) a polyethylene adipate polyester in admixture with bis-(hydroxymethyl)-1,4-cyclohexane and tri-(hydroxymethyl) propane was reacted with hexane 1,6-diisocyanate in chlorobenzene. Specification 862,675 is referred to.
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