摘要:
A resin composition for an automobile bumper comprising components (A), (B), and (C) described below:
(A) 45 to 74% by weight of a crystalline ethylene-propylene block copolymer having (a) a flexural modulus of 15,000 kg/cm² or more, (b) an ethylene content of 5 to 20% by weight, (c) an intrinsic viscosity (decalin, 135°C) of a portion soluble in p-xylene at room temperature of 3 or more, (d) a melt flow index (MI) of 21 to 70 g/10 min., and (e) a content of a portion insoluble in boiling n-heptane of 97% by weight or more; (B) 21 to 35% by weight of elastomer selected from the group consisting of components (I), (II) and (III) and having a weight ratio of (I) : [(I) + (II) + (III)] of from 0.5 to 1.0, (a) said component (1) being an amorphous ethylene-butene copolymer having a butene content of 10 to 25% by weight and a Mooney viscosity value, (ML₁₊₄, 100°C) of 5 to 20, (b) said component (II) being an amorphous ethylene-propylene copolymer having an ethylene content of 70 to 90% by weight and a Mooney viscosity value (ML₁₊₄, 100°C) of 5 to 40, and (c) said component (III) being a hydrogenated block copolymer consisting of 10 to 40% by weight of an aromatic vinyl polymer block X and 60 to 90% by weight of a conjugate diene polymer block Y, having a structure of said block components being X - Y or X - (Y - X) n , wherein n is 1 or 2, 90 mol% or more of said block Y being hydrogenated and the melt flow index (MI) of the hydrogenated block copolymer being 5 g/10 min. (230°C, 2.16 kg) or more, and; (C) 5 to 10% by weight of talc having a combustion loss of 7% by weight or less, containing no particles having a diameter of 10 µm or more and having an average particle diameter D₅₀ of 1.0 to 3.0 µm.
摘要:
A polypropylene resin composition comprising the following components (A), (B), (C) and (D): (A) a crystalline ethylene-propylene block copolymer containing a room-temperature-p-xylene-soluble fraction Ac having an ethylene content of 12-26% by weight and an intrinsic viscosity (measured at 135°C in decalin) of 6 dl/g or more, (B) a crystalline ethylene-propylene block copolymer containing a room-temperature-p-xylene-soluble fraction Bc having an ethylene content of 27-50% by weight and an intrinsic viscosity (measured at 135°C in decalin) of 4 dl/g or less, (C) an ethylene-α-olefin copolymer obtained by polymerization using a single-site catalyst, having a molecular weight distribution (Mw/Mn) of 2.5 or less, a melt flow ratio (MI 10 /MI 2.16 ) of 6-15 (wherein MI 10 is a melt index measured at 190°C under a load of 10kg and MI 2.16 is a melt index measured at 190°C under a load of 2.16kg) and an α-olefin proportion of 70 mole % or less, and (D) a talc having an average particle diameter of 3-7 µm as measured by laser diffraction. In the composition the weight ratios As and Bs of the room-temperature-p-xylene-soluble fractions Ac and Bc to the total weight of the components (A) and (B) satisfy the following formulas (1) and (2): (1) As + Bs = 7-15% by weight (2) As/(As + Bs) = 0.1-0.6 The polypropylene component contained in each of the components (A) and (B) has an isotactic pentad fraction (mmmm) of 96% or more, and the mixture of the components (A) and (B) has a melt flow rate (measured at 230°C under a load of 2,160 g) of 30-70 g/10-min, the total content of the components (A) and (B) is 50-80% by weight, the content of the component (C) is 5-20% by weight, and the content of the component (D) is 15-30% by weight, and the composition comprising the components (A), (B), (C) and (D) has a melt flow rate (measured at 230°C under a load of 2,160 g) of 25 g/10-min or more. The composition is superior in stiffness, resistance to heat deformation, impact resistance and moldability and can provide a molded article of good appearance.
摘要:
Disclosed is a polypropylene resin composition for car upholstery, comprising (a) a crystalline polypropylene, (b) particular hydrogenated block copolymer(s), (c) particular hydrogenated block copolymer(s) different from (b), and (d) a particular talc.
摘要:
A thermoplastic resin composition with improved low-temperature impact strength and rigidity against heat, comprising (I) 10-40% by weight of a mixture of (a) 10-50% by weight of a propylene homopolymer and/or an ethylene-propylene block copolymer (an isotactic pentad fraction of a propylene homopolymer portion being 0.98 or above) and (b) 50-90% by weight of an olefin-based copolymer rubber, said mixture having been dynamically heat treated in the presence of an organic peroxide and a crosslinking agent, (II) 20-85% by weight of a propylene homopolymer and/or an ethylene-propylene block copolymer (an isotactic pentad fraction of a propylene homopolymer portion being 0.98 or above and a melt index of the propylene homopolymer portion being 30-150 g/10 min), and (III) 5-40% by weight of an inorganic filler.
摘要:
A resin composition having excellent paint coatability comprising: (A) 50-80 weight % of a multi-stage polymerized propylene-ethylene block copolymer consisting essentially of (i) a propylene homopolymer portion, (ii) a propylene-ethylene random copolymer portion, and (iii) an ethylene homopolymer portion, said propylene-ethylene block copolymer being characterized that an intrinsic viscosity of said propylene homopolymer portion (i) is 0.9-1.2 dl/g, an intrinsic viscosity of said propylene-ethylene random copolymer portion (ii) is 4.0 dl/g or more, and an ethylene content of said propylene-ethylene random copolymer portion (ii) is 30-70 weight %; (B) 20-40 weight % of an ethylene-α-olefin copolymer elastomer; and (C) up to 20 weight % of an inorganic filler.