| 摘要 |
PROBLEM TO BE SOLVED: To provide an effective method for producing a polyester free from heavy metals such as antimony, having excellent color tone and little in the content of DEG(diethylene glyeol). SOLUTION: A polyester is produced from terephthalic acid, bifunctional carboxylic acids composed mainly of terephtalic acid or an ester-forming derivative of terephtalic acid, with ethylene glycol, glycols mainly composed of ethylene glycol or an ester-forming derivative of ethylene glycol. In the production, (1) an aromatic sulfonic acid compound or its anhydride, (2) an alkali metal compound or an alkaline earth metal compound and (3) a phosphorus compound, are added each in a specific amount, as catalyst.
|
