| abstract |
A polymerization catalyst for polyester production which is a solution of solutes comprising an aluminum compound and an alkali compound in water, an organic solvent, or a mixture of both; and a process for producing a polyester which comprises esterifying or transesterifying an aromatic dicarboxylic acid or an ester-forming derivative thereof with a diol or an ester-forming derivative thereof and condensation-polymerizing the resultant reaction product, characterized by using the polymerization catalyst containing an aluminum compound. The catalyst can yield a polyester having excellent moldability and being usable for producing moldings such as fibers, films, resins, bottles, etc., without posing problems such as nozzle fouling, filtering pressure increase, thread breakage, film breakage, and defects caused by foreign substances. |