Polypropylene resin composition, resin molded part and production method thereof

A polypropylene resin composition comprising 2 to 15 wt % of a moldability improver (A) and 85 to 98 wt % of a polypropylene resin (B) based on the total weight of the polypropylene resin composition,

• the moldability improver (A) containing 80 to 95 wt % of a propylene block copolymer (A-1) and 5 to 20 wt % of a propylene block copolymer (A-2) based on the total weight of the moldability improver (A),
• the propylene block copolymer (A-1) including 80 to 95 wt % of a crystalline propylene polymer component (A-11) and 5 to 20 wt % of a propylene-ethylene random copolymer component (A-12) based on the total weight of the propylene block copolymer (A-1) and satisfying the following properties:
• (a-11) the crystalline propylene polymer component (A-11) has a melt flow rate of 300 g/10 minutes or higher;
• (a-12) the propylene-ethylene random copolymer component (A-12) has an ethylene content of 20 to 70 wt %;
• (a-13) the propylene-ethylene random copolymer component (A-12) has an intrinsic viscosity of 6.5 dl/g or higher;
• and (a-14) the propylene block copolymer (A-1) has an overall melt flow rate of 80 g/10 minutes or higher,
• the propylene block copolymer (A-2) including 30 to 65 wt % of a crystalline propylene polymer component (A-21) and 35 to 70 wt % of a propylene-ethylene random copolymer component (A-22) based on the total weight of the propylene block copolymer (A-2) and satisfying the following properties:
• (a-21) the crystalline propylene polymer component (A-21) has a melt flow rate of 20 g/10 minutes or higher;
• (a-22) the propylene-ethylene random copolymer component (A-22) has an ethylene content of 20 to 70 wt %;
• (a-23) the propylene-ethylene random copolymer component (A-22) has an intrinsic viscosity of 4.0 to 9.0 dl/g or higher;
• and (a-24) the propylene block copolymer (A-2) has an overall melt flow rate of 0.1 to 79 g/10 minutes,
• the polypropylene resin (B) containing 55 to 85 wt % of a propylene-ethylene block copolymer (B-1), 5 to 20 wt % of at least one of an ethylene elastomer and a styrene elastomer (B-2) and 10 to 25 wt % of an inorganic filler (B-3) based on the total weight of the polypropylene resin (B),
• the propylene-ethylene block copolymer (B-1) including less than 35 wt % of a propylene-ethylene random copolymer component (B-12) based on the total weight of the propylene-ethylene block copolymer (B-1), and
• the inorganic filler (B-3) being either talc, mica, glass fiber or wisker.