| abstract |
The invention provides a polycondensation catalyst for producing polyester by an esterification reaction or a transesterification reaction between a dicarboxylic acid or ester-forming derivative thereof and a glycol, wherein the polycondensation catalyst comprises particles of a solid base having on their surfaces either a coat layer of titanic acid in an amount of from 0.1 to 50 parts by weight in terms of TiO 2 per 100 parts by weight of the solid base, or an inner coat layer of an oxide of at least one element selected from silicon, aluminum and zirconium or a composite oxide of at least two elements selected from silicon, aluminum and zirconium in an amount of from 1 to 20 parts by weight per 100 parts by weight of the solid base and an outer coat layer of titanic acid in an amount of from 0.1 to 50 parts by weight in terms of TiO 2 per 100 parts by weight of the solid base |