US 6,441,081 B1 · Polypropylene-base resin composition and products of injection molding thereof

Abstract

A polypropylene resin composition which comprises: (1) 55 to 75% by weight of (A) a polypropylene resin consisting of a mixture of the following polymers (i) and (ii): (i) a propylene-ethylene block copolymer having a propylene homopolymer part which is the first segment and having a propylene-ethylene random copolymer part which is the second segment and (ii) a propylene homopolymer having an intrinsic viscosity [η]P of 0.8 to 1.8 dl/g as measured in tetralin at 135° C., (2) 21 to 30% by weight of (B) an ethylene-1-octene copolymer rubber having a melt flow rate (JIS-K-6758 at 190° C.) of 2 to 10 g/10 min and having a 1-octene component content of 20 to 25% by weight, and (3) 5 to 20% by weight of (C) talc having an average particle diameter of not more than 3 μm, wherein when the amount of the second segment contained in the propylene-ethylene block copolymer of the polypropylene resin (A) is designated as (A)′ and the ethylene-1-octene copolymer rubber content is designated as (B)′, the following expression is satisfied: 0.10≦{(A)′/[(A)′+(B)′]}≦0.30, and when the above composition is subjected to a tensile test according to ASTM D638, it exhibits, an ultimate elongation of at least 400%, and the melt flow rate (JIS-K-6758 at 230° C.) of the composition is at least 30 g/10 min, and an injection-molded article obtained by injection molding the above polypropylene resin composition.

Claims10

Dependent claims

A polyropylene resin composition which comprises:

(1) 55 to 75% by weight of (A) a polypropylene resin consisting of a mixture of the following polymers (i) and (ii):
(i) 10 to 40% by weight of a propylene-ethylene block copolymer comprised-of a propylene homopolymer first segment and a propylene-ethylene random copolymer second segment, said second segment having an ethylene content of 25 to 55% by weight, and said second segment being present in said block copolymer in an amount of 5 to 30% by weight and
(ii) 90 to 60% by weight of a propylene homopolymer having an intrinsic viscosity [η]P of 0.8 to 1.8 dl/g as measured in tetralin at 135° C., wherein the amount of (i)+(ii) is 100% by weight,
(2) 21 to 30% by weight of (B) an ethylene-1-octene copolymer rubber having a melt flow rate measured according to JIS-K-6758 under a load of 2.16 kg at 190° C. of 2 to 10 g/10 min and having a 1-octene component of 20 to 25% by weight, and
(3) 5 to 20% by weight of (C) talc having an average particle diameter of not more than 3 μm, wherein when the amount of the second segment contained in the propylene-ethylene block copolymer of the polypropylene resin (A) is designated as (A)′ and the ethylene-1-octene copolymer rubber content is designated as (B)′, the following expression is satisfied:
0.10≦{(A)′/[(A)′+(B)′]}≦0.30,
when the composition is subjected to a tensile test according to ASTM D638 at 23° C., it exhibits an ultimate elongation of at least 400%, and the melt flow rate measured according to JIS-K-6758 under a load of 2.16 kg at 230° C. of the composition is at least 30 g/10 min.

4 more elements

A polypropylene resin composition which comprises:

(1) 55 to 75% by weight of (A) a polypropylene resin consisting of a mixture of the following polymers (i) and (ii):
(i) 10 to 40% by weight of a propylene-ethylene block copolymer comprised of a propylene homopolymer first segment and a propylene-ethylene random copolymer second segment, said second segment having an ethylene content of 25 to 55% by weight, and said second segment being present in said block copolymer in an amount of 5 to 30% by weight and
(ii) 90 to 60% by weight of a propylene homopolymer having an intrinsic viscosity [η]P of 0.8 to 1.8 dl/g as measured in tetralin at 135° C., wherein the total of (i)+(ii) is 100% by weight, and the propylene homopolymer part of (i) and (ii) respectively has a Q value, which is the weight average molecular weight (Mw)/number average molecular weight (Mn) ratio, of 3.0 to 5.0 and an isotactic pentad fraction as calculated by 13C-NMR of at least 0.97,
(2) 21 to 30% by weight of (B) an ethylene-1-octene copolymer rubber having a melt flow rate measured according to JIS-K-6758 under a load of 2.16 kg at 190° C. of 2 to 10 g/10 min, a 1-octene component content of 20 to 25% by weight and a density of 0.860 to 0.875 g/cm31, and
(3) 5 to 20% by weight of (C) talc having an average particle diameter of not more than 3 μm, wherein when the amount of the second segment contained in the propylene-ethylene block copolymer of the polypropylene resin (A) is designated as (A)′ and the ethylene-1-octene copolymer rubber content is designated as (B)′, the following expression is satisfied:
0.10≦{(A)′/[(A′+(B)′]}≦0.30,
when the composition is subjected to a tensile test according to ASTM D638 at 23° C., it exhibits an ultimate elongation of at-least 400%, the melt flow rate measured according to JIS-K-6758 under a load of 2.16 kg at 230° C. of the composition is at least 30 g/10 min, and the density of the polypropylene resin composition is 0.95 to 1.05 g/cm3.

4 more elements

Dependencies are inferred from the claim text.

Polypropylene-base resin composition and products of injection molding thereof

Life of this patent

Polypropylene-base resin composition and products of injection molding thereof

Life of this patent

Abstract

Claims10