Abstract: Disclosed are a resin composition comprising a polylactic acid resin and a polyacetal resin, and such a resin composition in which the polylactic acid resin and the polyacetal resin are kept miscible with each other. The resin composition has good moldability, workability, mechanical properties, heat resistance and transparency, and may be worked into moldings, films and fibers for practical use.

Abstract: A polyester composition prepared by melting and blending a polyester with a glycidyl ester compound, a glycidyl ether compound and a catalyst has good hydrolysis resistance and, when melted, gives little gas generation and undergoes little viscosity change. It is most favorable for parts of automobile, electric and electronic appliances such as connectors.

Abstract: A method for producing polybutylene terephthalate comprising continuously esterifying a dicarboxylic acid component consisting essentially of terephthalic acid with a diol component consisting essentially of 1,4-butanediol followed by polycondensing the resulting oligomer, wherein the esterification is effected in a molar ratio, P, of the diol component to the dicarboxylic acid component to fall between 1.1 and 1.6, in the presence of a combination of an organic titanium compound and an organic tin compound that satisfies the following requirement:amount of organic titanium compound (mol %).ltoreq.0.08.times.P-0.07where P=molar ratio of diol component to dicarboxylic acid component, and is followed by the polycondensation.