摘要 |
A linear, highly polymerized polyester is prepared by polycondensing a glycol ester of aromatic dicarboxylic acid and/or a low molecular weight condensate thereof by using as polycondensation catalyst a preformed antimony compound which is obtained from the reaction of esterified trimellitate with an antimony compound selected from a member of antimony halide, antimony carbyxylate and antimony carbyxylate. The above-mentioned esterified trimellitate is prepared by reacting trimellitic acid or trimellitic anhydride with alcohols such as alkyl alcohol or alkane diol and treating successively organic or inorganic base with the resultant reaction product, and comprises, depending on the type of alcohol used, a mixture of 1-alkoxycarbonyl-2,4-benzenedicarboxylate and 2-alkoxycarbonyl-1,4-benzenedicarboxylate or a mixture of 1-(hydroxyalkoxycarbonyl)-2,4-benzenedicarboxylate and as a main 2-(hydroxyalkoxycarbonyl)-1,4-benzenedicarboxylate component. A high quality polyester having a low content of terminal carboxyl group and diethylene glycol group, an excellent color tone and a high melting point may be prepared by using preformed antimony compound in a short polycondensation time.
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