Polypropylene-based resin composition and foam sheet

Patent metadata

Field	Value
Publication number	US-9284427-B2
Application number	US-201314372936-A
Country	US
Kind code	B2
Filing date	Feb 22, 2013
Priority date	Feb 23, 2012
Publication date	Mar 15, 2016
Grant date	Mar 15, 2016

Abstract

Provided is a polypropylene-based resin composition which gives uniform and fine cells and from which a foamed sheet and thermoform excellent in appearance, thermoformability, impact resistance, lightness, stiffness, heat resistance, heat insulating properties, oil resistance and the like can be produced. A polypropylene-based resin composition comprising (X) 5 to 99% by weight of a polypropylene resin having a structure with long chain branches, and (Y) 1 to 95% by weight of a propylene-based block copolymer produced by sequential polymerization, which block copolymer comprises (Y-1) a propylene (co)polymer and (Y-2) a propylene-ethylene copolymer.

First claim

The invention claimed is:

1. A polypropylene-based resin composition comprising:
(X) 5 to 99% by weight of a polypropylene resin having a structure with long chain branches, and
(Y) 1 to 95% by weight of a propylene-based block copolymer produced by sequential polymerization, which comprises:
(Y-1) a propylene (co)polymer, and
(Y-2) a propylene-ethylene copolymer,

wherein the resin (X) has the following properties (X-i) to (X-iv):
(X-i): MFR of 0.1 to 30.0 g/10 minutes,
(X-ii): a molecular weight distribution Mw/Mn of 3.0 to 10.0 measured by GPC and Mz/Mw of 2.5 to 10.0,
(X-iii): a melt tension (MT) (unit: g) satisfying the relationship:
log(MT)≧−0.9×log(MFR)+0.7, or

MT≧15,

(X-iv): a content of p-xylene soluble components (CXS) at 25° C. of less than 5% by weight based on a total amount of the resin (X), and

the block copolymer (Y) has the following properties (Y-i) to (Y-v):
(Y-i): ratios of the amounts of the (Y-1) and (Y-2) of 50 to 99% by weight and 1 to 50% by weight, respectively, with the proviso that each ratio is calculated based on a total of 100% by weight of the block copolymer (Y),
(Y-ii): MFR of the block copolymer (Y) of 0.1 to 200.0 g/10 minutes,
(Y-iii): melting point of the block copolymer (Y) of more than 155° C.,
(Y-iv): an ethylene content of the (Y-2) of 11.0 to 38.0% by weight, with the proviso that the ethylene content is calculated based on a total of 100% by weight of monomers constructing the (Y-2), and
(Y-v): an intrinsic viscosity [η] (unit: dl/g) of the (Y-2) measured at 135° C. in decalin of 5.3 or more.

2. The composition of claim 1 , wherein the resin (X) further has the following property (X-v):
(X-v): a branching index g′ of 0.30 or more and less than 1.00 at an absolute molecular weight M abs of 1,000,000.

3. The composition of claim 2 , wherein the resin (X) further has the following property (X-vi):
(X-vi): mm fraction of 95% or more in the propylene unit triads measured by 13 C-NMR.

4. A polypropylene-based resin composition comprising:
100 parts by weight of the composition of claim 1 , and
0.05 to 6.0 parts by weight of a blowing agent.

5. A polypropylene-based resin foamed sheet obtained by a process comprising subjecting the composition of claim 4 to extrusion.

6. A polypropylene-based resin multi-layer foamed sheet obtained by a process comprising subjecting the foamed sheet of claim 5 and a non-foamed layer comprising a thermoplastic resin composition to co-extrusion.

7. The multi-layer foamed sheet of claim 6 , wherein the thermoplastic resin composition comprises:
100 parts by weight of a thermoplastic resin, and
50 parts by weight or less of an inorganic filler.

8. A molded article obtained by a process comprising subjecting the foamed sheet of claim 5 to thermoforming.

9. A molded article obtained by a process comprising subjecting the composition of claim 1 to injection molding, thermoforming, extrusion, blow molding or bead expansion molding.

10. A propylene-based resin composition comprising:
100 parts by weight of the composition of claim 1 , and
(Z) more than 0 part by weight and 1000 parts by weight or less of another resin having none of the properties (X-i) to (X-iv) and (Y-i) to (Y-v).

11. The composition of claim 10 , wherein the resin (Z) is a polypropylene-based resin.

Assignees

• Japan Polypropylene Corp

Inventors

• Hotta Sachio
• Asuka Kazuo
• Kitade Shinichi
• Takahashi Kuninori
• Kouzai Iku
• Tayano Takao

Classifications

• C08L23/12 Primary

  Polypropene · CPC title

• B29K2509/00

  Use of inorganic materials not provided for in groups {B29K2503/00 - B29K2507/00,} as filler · CPC title

• B32B2307/558

  Impact strength, toughness · CPC title

• C08L2203/14

  used for foams · CPC title

• B29K2023/12

  PP, i.e. polypropylene · CPC title