To produce a polyester producing catalyst capable of being easily produced and handled and capable of producing such a polyester as to have good color and to be more improved in heat stability, volume specific resistance, an acetaldehyde content, and a foreign matter content than ever, and to provide a method for producing the polyester, capable of producing the polyester having the above excellent characteristics with good productivity, by using the catalyst.
The polyester producing catalyst contains at least (1) a group 4A compound, (2) a compound of at least one kind of element selected from the group consisting of magnesium, calcium, and zinc and an oxygen-containing organic solvent, and if necessary, (3) a silicic acid ester compound. The method for producing the polyester comprises subjecting a dicarboxylic acid component consisting mainly of an aromatic dicarboxylic acid and/or an ester-forming derivative thereof to polycondensation reaction with a divalent alcohol component, by using the polyester producing catalyst, through esterification reaction and/or ester interchange reaction of the components.
MUNAKATA MOTOHIRO
MORI TORU
AKAI TOSHIO
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