| 摘要 |
PROBLEM TO BE SOLVED: To recover an aromatic dicarboxylic acid, in particular terephthalic acid having sufficient purity and satisfactory color characteristics from an article produced from an ethylene terephthalic acid copolymer or an article containing the copolymer so as to reuse the aromatic dicarboxylic acid. SOLUTION: In aromatic polyester-resin article fragmented into a chip from is reacted in a solution in a carboxylic acid with 2-6 carbon atoms and with a pKa from 4 to 6, preferably glacial acetic acid in the presence of a catalytic quantity of a strong acid with a pKa of less than 1, preferably aqueous hydrochloric acid or sulfuric acid at temperatures from 160 deg.C to 250 deg.C.
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