Polypropylene resin composition

• US 20020040105A1
• Filed: 06/27/2001
• Published: 04/04/2002
• Est. Priority Date: 06/30/2000
• Status: Active Grant

• Current Assignee: Sumitomo Chemical Company Limited
• Original Assignee: Sumitomo Chemical Company Limited
• Inventors: Atarashi, Kenji, Kanzaki, Susumu, Tsuji, Mitsuji
• Granted Patent: US 6,472,477 B2
• Time in Patent Office: Days
• US Class Current: 525/240
• CPC Class Codes: C08L 23/12 Polypropene
• CPC Class Codes: C08L 23/16 Elastomeric ethene-propene or ethene-propene-diene copolymers, e.g. EPR and EPDM rubbers
• CPC Class Codes: C08L 2666/24 Graft or block copolymers according to groups C08L51/00, C08L53/00 or C08L55/02; Derivatives thereof
• CPC Class Codes: C08L 53/00 Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers

Abstract

A polypropylene resin composition comprising:

95 to 50% by weight of a propylene homopolymer (A) having an intrinsic viscosity [η]^A of not more than 1.3 dl/g; and

5 to 50% by weight of a propylene-ethylene block copolymer (B) having a propylene homopolymer portion having an intrinsic viscosity [η]^B_P of from 1.4 to 2.0 dl/g, and a propylene-ethylene random copolymer portion having an intrinsic viscosity [η]^B_EP of from 4.0 to 15 dl/g, the polypropylene resin composition having a melt flow rate of from 5.0 to 150 g/10 min.

Claims

1. A polypropylene resin composition comprising:

95 to 50% by weight of a propylene homopolymer (A) having an intrinsic viscosity [η

]^A of not more than 1.3 dl/g; and

5 to 50% by weight of a propylene-ethylene block copolymer (B) having a propylene homopolymer portion having an intrinsic viscosity [η

]^B_P of from 1.4 to 2.0 dl/g, and a propylene-ethylene random copolymer portion having an intrinsic viscosity [η

]^B_EP of from 4.0 to 15 dl/g, the polypropylene resin composition having a melt flow rate of from 5.0 to 150 g/10 min. and the sum of the (A) and (B) being 100% by weight.

2. The polypropylene resin composition according to claim 1, wherein the intrinsic viscosity [η

]^A of the propylene homopolymer portion is from 0.7 to 1.3 dl/g.

3. The polypropylene resin composition according to claim 1, wherein the intrinsic viscosity [η

]^B_P of the propylene-ethylene random copolymer portion is from 1.5 to 1.9 dl/g.

4. The polypropylene resin composition according to claim 1, wherein the intrinsic viscosity [η

]^B_EP of the propylene-ethylene random copolymer portion is from 4.0 to 8.0 dl/g.

5. The polypropylene resin composition according to claim 1, comprising 90 to 60% by weight of the polypropylene propylene homopolymer (A), and 10 to 40% by weight of the propylene-ethylene block copolymer (B).

6. The polypropylene resin composition according to claim 1, wherein the melt flow rate (MFR) of the polypropylene resin composition is from 10 to 120 g/10 min.

7. The polypropylene resin composition according to claim 1, wherein the propylene-ethylene block copolymer (B) is obtained by a gas phase continuous polymerization method.

8. The polypropylene resin composition according to claim 1, wherein the die swell of the polypropylene resin composition is not less than 1.45.

9. The polypropylene resin composition according to claim 1, wherein the die swell of the polypropylene resin composition is not less than 1.50.

10. A molded product comprising the polypropylene resin composition according to claim 1.