THERMOPLASTIC RESIN COMPOSITION, INJECTION MOLDING METHOD THEREOF AND INJECTION MOLDED ARTICLE

摘要

A thermoplastic resin composition comprising a thermoplastic resin (A) not forming an anisotropic melt phase and a liquid crystal polymer (B) capable of forming an anisotropic melt phase, an injection molding method thereof and an injection molded article capable of providing a thin molded article having excellent mechanical strength. A thermoplastic resin composition (C) comprises 99 to 50 wt.% of the thermoplastic resin (A) and 1 to 50 wt.% of the liquid crystal polymer (B). The liquid crystal polymer (B) is microscopically dispersed in an island form in the matrix phase of the thermoplastic resin (A) so that when the composition (C) is heat-treated at a temperature not lower than the melting point of the liquid crystal polymer (B) under a non-load state and is then cooled, the liquid crystal polymer (B) has a weight average particle diameter within the range of 10 to 40 micrometers and at least 80 wt.% thereof has a particle diameter within the range of 0.5 to 60 micrometers. The injection molding method comprises carrying out injection molding of the thermoplastic resin composition (C) at a processing temperature greater than or equal to the flow beginning temperature of the liquid crystal polymer (B) and at a gate passage rate of the molten resin of at least 500 m/min, and an injection molded article characterized in that the liquid crystal polymer (B) is dispersed in a fibrous form in the matrix phase of the thermoplastic resin (A) at a mean aspect ratio of at least 6.