| 摘要 |
Copolyesters are made by polycondensing (a) one or more aliphatic, cycloaliphatic or aromatic dicarboxylic acids or anhydrides, esters or ammonium salts thereof, with at least an equivalent amount of (b) a substantially pure bis-(b -hydroxy ethyl) ester of a benzene dicarboxylic acid or a nuclear substituted derivative thereof, which acid is different from the aromatic acid of (a). Specified for (a) are adipic, sebacic, maleic acids, tetrahydrophthalic, tetrachloroterephthalic and ortho-, iso- and terephthalic acids. Specified for (b) are ortho-, iso- and tere-phthalic acids and their chloro and alkyl substitution products. Examples disclose reacting (1)-(4) bis-(b -hydroxyethyl) terephthalate and tetrachloroterephthalic acid, isophthalic acid, tetrahydrophthalic acid of diammonium isophthalate; (5) bis-(b -hydroxyethyl) tetrachlorophthalate and monomethyl terephthalate. |
