Abstract A polypropylene composition useful for producing a shaped article, for example, a bumper, having excellent rigidity, resistance to mechanical impact at a low temperature and superior lacquer-bonding property and appearance, comprises: (A) 40% to 75% by weight of at least one crystalline ethylene-propylene block copolymer in which the content of the polymerized ethylene is in the range of from 5% to 10% by weight, in which the polypropylene component has a fraction thereof insoluble in boiling n-heptane, in an amount of 97% or more, in which a fraction of the block copolymer soluble in p-xylene at room temperature, has an intrinsic viscosity of from 2.5 to 4 determined in decahydronaphthalene at a temperature of 135 DEG C. and which has a melt flow index of from 11 to 70; (B) 20% to 40% by weight of at least one amorphous ethylene-propylene copolymer having an intrinsic viscosity of from 1.0 to 2.0 determined in decahydronaphthalene at a temperature of 135 DEG C., and a Mooney viscosity ML1+4 of from 5 to 40 determined at a temperature of 100 DEG C.; and (C) 5% to 20% by weight of talc in the form of fine particles having an average size of from 0.1 to 5 microns.
Inventors
👤 Osamu Fukui
👤 Yoshiro Umemoto
👤 Tsugumi Sanmiya
👤 Yutaka Sano
👤 Kazuyoshi Tanaka
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-10-30 06:39
CPC Classifications
C; C08; C08K; C08K3/00; C08K3/34; C08L; C08L53/00
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
186 words
A propylene polymer composition comprising (A) 40% to 75% by weight of at least one crystalline ethylene-propylene block copolymer in which the content of the polymerized ethylene is in the range of from 5% to 10% by weight, in which the polypropylene component has a fraction thereof insoluble in boiling n-heptane, in an amount of 97% or more based on the weight of said polypropylene component, in which a fraction of the block copolymer soluble in p-xylene at room temperature, has an intrinsic viscosity of from 2.5 to 4 determined in decahydronaphthalene at a temperature of 135° C. and which block copolymer has a melt flow index of from 11 to 70; (B) 20% to 40% by weight of at least one amorphous ethylene-propylene copolymer having an intrinsic viscosity of from 1.0 to 2.0 determined in decahydronaphthalene at a temperature of 135° C., and a Mooney viscosity ML 1+4 of from 5 to 40 determined at a temperature of 100° C.; and (C) 5% to 20% by weight of talc in the form of fine particles having an average size of from 0.1 to 5 microns.
Claim 2
Dependent Claim
186 words
A propylene polymer composition comprising (A) 40% to 75% by weight of at least one crystalline ethylene-propylene block copolymer in which the content of the polymerized ethylene is in the range of from 5% to 10% by weight, in which the polypropylene component has a fraction thereof insoluble in boiling n-heptane, in an amount of 97% or more based on the weight of said polypropylene component, in which a fraction of the block copolymer soluble in p-xylene at room temperature, has an intrinsic viscosity of from 2.5 to 4 determined in decahydronaphthalene at a temperature of 135° C. and which block copolymer has a melt flow index of from 11 to 70; (B) 20% to 40% by weight of at least one amorphous ethylene-propylene copolymer having an intrinsic viscosity of from 1.0 to 2.0 determined in decahydronaphthalene at a temperature of 135° C., and a Mooney viscosity ML 1+4 of from 5 to 40 determined at a temperature of 100° C.; and (C) 5% to 20% by weight of talc in the form of fine particles having an average size of from 0.1 to 5 microns.
Claim 3
Dependent Claim
17 words
The composition as claimed in claim 1, which exhibits a melt flow index of at least 7.0.
Claim 4
Dependent Claim
22 words
The composition as claimed in claim 1, wherein said crystalline ethylene-propylene block copolymer has a melt flow index of 12 to 50.
Claim 5
Dependent Claim
25 words
The composition as claimed in claim 1, wherein the Mooney viscosity of said amorphous ethylene-propylene copolymer is in the range of from 10 to 40.
Claim 6
Dependent Claim
22 words
The composition as claimed in claim 1, wherein said talc fine particles have an average size of from 0.5 to 3 microns.
Claim 7
Dependent Claim
34 words
The composition as claimed in claim 1, wherein the amounts of said crystalline ethylene-propylene block copolymer and said amorphous ethylene-propylene copolymer are 45% to 70% by weight and 20% to 35% by weight, respectively.