PURPOSE: To obtain a molded product which generates little gas at the time of molding and has a favorable surface form, by performing injection molding of copolyester whose concentration of a terminal acetyl group is low.
CONSTITUTION: Injection molding of copolyester which possesses a unit shown by a formula at 5W95mol% of the whole repeating unit constituting a main chain of polyester and concentration of a terminal acetyl group is 10 equivalents/106g or lower is performed. When transparency is made much of, noncrystalline material is favorable; when heat resistance is made much of, though the fusion point becomes high, a crystalline material is favorable; and to make the heat resistance and melt molding properties compatible with each other, a thermotropic liquid crystalline material is favorable. Intrinsic viscosity (η) of the copolyester is preferably 0.6W10.0. When the viscosity is lower than this range, the title molded product is inferior in physical and mechanical charac teristic values including heat resistance and when the viscosity is higher than this range, it follows that fluidity is spoiled and moldability becomes worse.
MATSUMOTO TETSUO
MAKITA HIROTOSHI
SAKAI KUMIKO
