Oriented polymeric microporous films

• US 5,317,035 A
• Filed: 12/18/1992
• Issued: 05/31/1994
• Est. Priority Date: 12/21/1990
• Status: Expired due to Term

• Current Assignee: Rkw Se (JM Holding GmbH & Co. KGaA)
• Original Assignee: Amoco Corporation (BP PLC)
• Inventors: Clingman, Scott R., Jacoby, Philip, Bauer, Charles W., Tapp, William T.
• Primary Examiner(s): Lesmes, George F.
• Assistant Examiner(s): RAIMUND, CHRISTOPHER W
• Application Number:
  US07/993,300
• Time in Patent Office: 529 Days
• Field of Search: 521/143, 525/95, 525/191, 524/427
• US Class Current: 521/143
• CPC Class Codes: C08J 2323/10 Homopolymers or copolymers of propene
• CPC Class Codes: C08J 5/18 Manufacture of films or sheets
• CPC Class Codes: C08L 2205/02 containing two or more polymers of the same C08L -group
• CPC Class Codes: C08L 2205/03 containing three or more polymers in a blend
• CPC Class Codes: C08L 2205/035 containing four or more polymers in a blend
• CPC Class Codes: C08L 2205/242 Beta spherulite nucleating agents
• CPC Class Codes: C08L 23/10 Homopolymers or copolymers of propene
• CPC Class Codes: C08L 23/12 Polypropene
• CPC Class Codes: C08L 23/14 Copolymers of propene C08L23/16 takes precedence
• CPC Class Codes: C08L 23/20 having four to nine carbon atoms
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 2666/04 Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
• 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 51/06 grafted on to homopolymers or copolymers of aliphatic hydrocarbons containing only one carbon-to-carbon double bond
• 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
• CPC Class Codes: Y10T 428/249978 Voids specified as micro
• CPC Class Codes: Y10T 428/249986 Void-containing component contains also a solid fiber or solid particle

Abstract

Polyolefin resin compositions and oriented microporous films prepared from same comprising an ethylene-propylene block copolymer having an ethylene content of about 10 to about 50 wt %, a propylene homopolymer or random propylene copolymer having up to about 10 wt % of a comonomer of ethylene or an α-olefin of 4 to 8 carbon atoms, a low molecular weight polypropylene, a beta-spherulite nucleating agent and an inorganic filler. The microporous films have improved breathability, strength, toughness and break elongation.

Claims

1. A polymeric composition comprising,

about 40 to about 90 parts by weight of a component A comprising an ethylene-propylene block copolymer having an ethylene content of about 10 to about 50 wt %,

about 5 to about 40 parts by weight of a component B comprising a propylene homopolymer or random copolymer having up to about 10 wt % of a comonomer of ethylene or an α

-olefin of 4 to 8 carbon atoms,

about 1 to about 5 parts by weight, per 100 parts by weight of components A and B, of a component C comprising a low molecular weight polypropylene having a melt viscosity of about 50 to about 1,000 poise measured at a shear rate of 136 sec^-1 and 190°

C.,

about 5 to about 30 parts by weight, per 100 parts by weight of components A and B, of a component D comprising calcium carbonate, and

about 0.1 to about 10 ppm, per 100 parts by weight of components A and B, of a component E comprising a beta-spherulite nucleating agent.

2. The polymeric composition of claim 1 wherein said beta-spherulite nucleating agent comprises a red quinacridone dye.

3. The polymeric composition of claim 2 wherein said red quinacridone dye has the structural formula:

##STR3##

4. The polymeric composition of claim 3 wherein said low molecular weight polypropylene has a melt viscosity of about 70 to about 550 poise measured at a shear rate of 136 sec^-1 and 190°

C.

5. The polymeric composition of claim 4 wherein said ethylene-propylene block copolymer has an ethylene content of about 30 to about 45 wt %.

7. The polymeric composition of claim 1 or 6 wherein said component B consists of a propylene homopolymer.

6. A polymeric composition comprising,

about 30 to about 95 parts by weight of a component A comprising an ethylene-propylene block copolymer having an ethylene content of about 10 to about 50 wt %,

about 70 to about 5 parts by weight of a component B comprising a propylene homopolymer or random copolymer having up to about 10 wt % of a comonomer of ethylene or an α

-olefin of 4 to 8 carbon atoms,

about 1 to about 10 parts by weight, per 100 parts by weight of components A and B, of a component C comprising a low molecular weight polypropylene having a melt viscosity of about 50 to about 1,000 poise measured at a shear rate of 136 sec^-1 and 190°

C.,

about 5 to about 30 parts by weight, per 100 parts by weight of components A and B, of a component D comprising calcium carbonate, and

about 0.1 to about 10 ppm, per 100 parts by weight of components A and B, of a component E comprising a beta-spherulite nucleating agent.