PURPOSE: To obtain a polyester containing uniform fine particles, which can give a molding of a smooth surface without causing yarn break or the like, by adding a phosphorus compound to a reaction product obtained from a lower alkyl terephthalate and a glycol and adding a specified slurry of CaCO3 to the mixture.
CONSTITUTION: A phosphorus compound (e.g., trimethyl phosphate) as a color stabilizer is added to a reaction product obtained by transesterifying a lower alkyl terephthalate component with a glycol. To the polyester reaction prouduct to which said phosphorus compound has been added is added a 10W20wt% concentration slyrry obtained by adding inert inorganic particles such as CaCO3 of an average diameter of primary particle ≥10μ in an amount to provide a concentration of 204n40wt% to a (mixed) glycol such as ethylene glycol or its mixture with propylene glycol or the like, kneading the resulting mixture by application of shear in, e.g., a mixer to decrease the content of aggloverates, subjecting the mixture at a concentration of 10W30wt% to dispersion treatment by high-speed agitation by means of a high-speed agitator such as a jet agitator impeller and diluting the mixture.
KATAOBE KOICHI
OKAMOTO TSUKASA
