| 摘要 |
Copolyesters are made by condensing (a) one or more glycols of formula HO-(CH2)n-OH where n is 2-10, (b) one or more aromatic dicarboxylic acids (or ester-forming derivatives thereof) capable of forming a film- or fibreforming polyester with the above glycols, (c) 2,5-dihydroxyterephthalic acid (or an esterforming derivative thereof) in an amount of up to 3% by weight based on the aromatic dicarboxylic acid and (d) one or more aromatic dihydric alcohols of formula <FORM:1106568/C3/1> where R is a direct linkage or a bridge member, a is 1 to 10 and in which the benzene nuclei A and B may be substituted (e.g. by alkyl groups or halogen atoms). Specified aromatic dicarboxylic acids are terephthalic, isophthalic and naphthalene - 2:6 - dicarboxylic acids and mixtures thereof. Specified bridge members for the aromatic dihydric alcohol are <FORM:1106568/C3/2> <FORM:1106568/C3/3> and -NX-, where X is a hydrogen atom or a substituted or unsubstituted lower alkyl group. Examples disclose the manufacture of copolyesters by reacting (a) ethylene glycol, (b) dimethyl terephthalate or a mixture thereof with dimethyl isophthalate, (c) the dimethyl ester of 2,5-di-hydroxyterephthalic acid and (d) the bis(beta-hydroxyethyl -ether of bisphenol-A. Uses.-Fibres, films and moulded articles. |
