THERMOPLASTIC RESIN COMPOSITION HAVING SUPPRESSED MOLD-STAINING PROPERTY

摘要

PROBLEM TO BE SOLVED: To obtain a thermoplastic resin composition suitable for an injection molded article such as an interior automotive trim and having suppressed mold-staining properties. SOLUTION: This composition is obtained by compounding 100 pts.wt. of a mixture of components of (A) to (D) with components (E) to (G) each in an amount shown below. The mixture comprises (A) 55-75wt.% of a propylene-ethylene block copolymer having a melt flow rate(MFR) of a propylene homopolymer part of 15-50g/10min, an isotactic pentad fraction of a propylene homopolymer part of >=0.97 and an MFR of the block copolymer of 10-30g/10min and an ethylene content of 2-6wt.%, (B) 0-10wt.% of an ethylene-propylene copolymer rubber having a melting temperature of 30-60 deg.C and an MFR of 0.2-2g/10min, (C) 5-15wt.% of an ethylene-α-olefin copolymer rubber having a melting temperature of 60-100 deg.C and an MRF of 0.3-2g/10min and (D) 15-25wt.% of talc having an average particle size of <=5μm and a specific surface area of >=3.5m<2> /g. (E) A hindered amine having a structure of the formula in an amount of 0.05-2 pts.wt. (F) A triarylphosphite in an amount of 0.01-1 pts.wt. (G) A metal salt expressed by the formula, (RCOO)2 X (R is a monovalent hydrocarbon group having a molecular weight of 290-500; X is Zn, Mg or Ca) in an amount of 0.05-4 pts.wt.