| 摘要 |
PURPOSE:To obtain a polyester which can give a molding of excellent strength, by adding a liquid crystal polyester to the reaction system in the early stage of a polycondensation reaction of a reaction product of an aromatic dicarboxylic acid (lower alkyl ester) with an alkylene glcyol. CONSTITUTION:A copolymer oligomer obtained by decomposing a polyester (e.g., polyethylene terephthalate) with an aromatic hydroxymonocarboxylic acid (e.g., p-acetoxybenzoic acid) is acetylated and then polycondensed to obtain a liquid crystal polyester (B) represented by the formula (wherein Ar1-2 are each phenylene or naphthylene and R is polymethylene) and having an intrinsic viscosity as determined in an o-chlorophenol solvent at 30 deg.C of 0.10-0.60. While a reaction product (A) of an aromatic dicarboxylic acid (lower alkyl ester) [e.g., terephthalic acid (methyl ester)] with an alkylene glycol (e.g., ethylene glcyol) is being polycondensed at normal pressure, 1-20wt%, based on component A, component B is added and then polycondensed in a vacuum.
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