摘要 |
Disclosed are copolyesters based on terephthalic or isophthalic acids, or both and at least one of 1,3 bis(2-hydroxyethoxy)benzene and bis(4- beta -hydroxyethoxyphenyl) sulfone, which also contain 1,4 bis(2-hydroxyethoxy)benzene as one of the diol reactants in order to prepare solid copolyesters having improved folding endurance or fatigue resistance than the same copolyesters without such coreactant.
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