| 摘要 |
PURPOSE:To obtain a polyester outstanding in transparency, suitable for bottles, by solid phase polymerization of chips with specified acid value. CONSTITUTION:(A) aromatic dicarboxylic acid consisting mainly of terephthalic acid and (B) glycol consisting mainly of ethylene glycol are made to react to carry out polymerization followed by delivery and cooling to make chips pref. with an acid value 20-50eq/10<6>g, diameter 1-5mm and moisture content 0.1-0.5wt.%. Said chips are brought to solid phase polymerization in e.g. an inert gas (e.g. nitrogen) stream at a temperature below the melting point, thus obtaining the objective polyester.
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