Resin Modifier, Polycarbonate Resin Composition and Molded Article Thereof

摘要

A polycarbonate resin composition and a molded article thereof are described, which have good flame retardance and high thermal stability when molded under high temperature. The resin composition contains a resin modifier (B) containing a tetrafluoroethylene-based polymer (p1) and a vinyl polymer (p2) other than the polymer (p1). The resin modifier (B) is obtained by using an alkaline (earth) metal salt other than a sulfate salt to segregate from a latex containing the polymer (p1) and the polymer (p2). The polymer (p2) is formed by performing polymerization on a vinyl monomer (X) containing at least 20 mass % of an aromatic vinyl monomer (x1) in the presence of at least one emulsifier selected from a phosphoric acid-based emulsifier, a carboxylic acid-based emulsifier, and a nonionic emulsifier.

主权项

1. A resin modifier (B) containing a tetrafluoroethylene-based polymer (p1) and a vinyl polymer (p2) other than the polymer, and rendering the following resin composition containing the resin modifier meet the following conditions [1] and [2], wherein the resin composition comprises:
1 part by mass of the resin modifier (B), 100 parts by mass of a polycarbonate resin represented by formula (1) and having a viscosity-average molecular weight (Mv) of 23000, 0.1 part by mass of a phenol-based antioxidant represented by formula (2), 0.1 part by mass of a phosphite-based antioxidant represented by formula (3), and 0.05 parts by mass of potassium perfluorobutanesulfonate; the viscosity-average molecular weight of the polycarbonate resin is obtained by measuring a limiting viscosity [η] of a 0.5 g/dL methylene chloride solution at 25° C. with a Ubbelohde viscometer and the following equation:
[η]=1.23×10−4Mv0.83; the condition [1] is:
ΔMFR=(MFRA−MFRB)/MFRB×100(%)≦30(%), wherein MFRB is a melt mass-flow rate of the resin composition measured under conditions of a cylinder temperature of 320° C. and a load of 1.2 kg according to ISO1133, and MFRA is a melt mass-flow rate of the resin composition measured, after being left in a cylinder at a temperature of 320° C. for 15 minutes, under a condition of a load of 1.2 kg according to ISO1133; and the condition [2] is:
YI (yellowness index) value of a slab≦−20; wherein the YI value of the slab is measured by a reflected-light measurement method under conditions of a C-light source and a viewing angle of 2 degrees with a light-splitting colorimeter according to JIS K7105, dimensions of the slab are a length of 100 mm, a width of 50 mm, and a thickness of 2 mm, and the slab is made by performing an injection molding after the resin composition is left in a cylinder of an injection molding machine at a cylinder temperature set at 300° C. for 15 minutes.