| 摘要 |
PROBLEM TO BE SOLVED: To obtain a polyethylene terephthalate having an excellent hue and electroadhesion by feeding a solution prepared by dissolving a mixture of an Mg compound and an Sb compound in ethylene glycol to the production system after esterification reaction and before the start of polycondensation reaction. SOLUTION: The slurry of terephthalic acid, ethylene glycol and ethyl acid phosphate (in an amount of 10-1,000ppm in terms of the P atoms) is fed into an esterification reactor and reacted at a temperature of 220-270 deg.C under a pressure of 760-1,900mmHg. After the esterification reaction, an Mg compound (e.g. magnesium acetate) in an amount of 10-100ppm in terms of the Mg atoms and an Sb compound (e.g. Sb2 O3 ) in an amount to give an Mg/compound/Sb compound molar ratio of 0.5/1 to 2.5/1 are dissolved in ethylene glycol, and the obtained solution is added to the slurry. Next, the entire mixture is reacted at a temperature of 260-300 deg.C under a pressure of 0.1-20mmHg for a definite time in a polycondensation reactor. After the reaction, the formed polymer is withdrawn to obtain polyethylene terephthalate having a volume resistivity of 1×10<5> to 1×10<10>Ω.cm.
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