Polypropylene-based resin composition and molded article

A polypropylene-based resin composition, comprising

• a polypropylene-based resin (A) as the only resin component of the composition, or the polypropylene-based resin (A) and a polyethylene-based resin as the only resin components of the composition, and which comprise:
• 100 parts by mass of a polypropylene-based resin (A) (provided that, when the polypropylene-based resin composition contains the polyethylene-based resin and/or inorganic fillers, the total amount of the polypropylene-based resin (A) and the polyethylene-based resin and/or inorganic fillers is taken as 100 parts by mass),
• 0.80 to 5.0 parts by mass of one or more kinds of aluminum flakes (B) having an average particle size of 5 to 90 μm and
• 0.008 to 0.03 parts by mass of carbon black (C) and,
• wherein, when incident light is irradiated from the direction of 45° to the surface of a test piece obtained by molding the polypropylene-based resin composition by the following injection molding method, the lightness in the highlight direction)(L15°) and the lightness in the shade direction)(L110°) defined below satisfy the following relationships:
• L15°/L110°≥3.3 1.
• L110°≤27.0 2.
• [Lightness in highlight direction (L15°)] 3.
• When the regular reflection position of 90° with respect to the incident light at 45° is defined as 0°, the lightness in the highlight direction)(L15°) is the lightness of the reflected light at an angle shifted toward the incident light direction side by 15°) from this 0°,
• [Lightness in shade direction (L110°)] 4.
• When the regular reflection position of 90° with respect to the incident light at 45° is defined as 0°, the lightness in the shade direction)(L110°) is the lightness of the reflected light at an angle shifted toward the incident light direction side by 110°) from this 0°,
• [Injection Molding Method] 5.
• The polypropylene-based resin composition is injection-molded under conditions in which the barrel temperature is higher by (20 to 120°) C. than the highest temperature of the glass transition temperature and/or crystal melting temperature of the polypropylene-based resin (A) and the polyethylene-based resin, the injection speed is 30 to 50 mm/sec, the mold set temperature is lower by (50 to 100°) C. than the highest temperature of the glass transition temperature and/or crystallization temperature of the polypropylene-based resin (A) and the polyethylene-based resin, the cooling time is 10 to 20 seconds, and the mold clamping pressure is 30 to 80 t, to obtain a test piece composed of a square plate with a thickness of 2 mm.