POLYESTER RESIN PELLET

• Main Authors: OZAWA FUMIO, TAKEGUCHI SHOHEI
• Format: Patent
• Language: English
• Published: 02.08.2000
• Edition: 7
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP

PROBLEM TO BE SOLVED: To provide polyester resin pellets the molding cycle time of which is short by reacting a dicarboxylic acid component comprising phthalic acid and/or isophthalic acid with a glycol component mainly comprising ethylene glycol and by specifying the intrinsic viscosity of the pellets and the content of a polyester resin powder having a specified average particle size. SOLUTION: The resin pellets are prepared by reacting a dicarboxylic acid component comprising terephthalic acid and/or isophthalic acid with a glycol component mainly comprising ethylene glycol, have an intrinsic viscosity of 0.5 or higher, and contain 0.01-5.0 wt.% polyester resin powder having an average particle size of 1 mm or lower. Polyester resin pellets containing a polyester resin powder are prepared, e.g. by a method wherein polyester resin pellets are mixed with a resin powder in the step of drying the pellets, by a method wherein a prepolymer is subjected to solid phase polymerization before or after being mixed with a resin powder, or by a method wherein resin pellets after polycondensation and solid-phase polymerization and having an intrinsic viscosity of 0.5 or higher are mixed with a resin powder, e.g. by using a mixer.