LAMINATED POROUS FILM AND SEPARATOR FOR BATTERY

• US 20110212358A1
• Filed: 02/26/2010
• Published: 09/01/2011
• Est. Priority Date: 02/26/2010
• Status: Active Grant

• Current Assignee: Mitsubishi Chemical Corporation (Mitsubishi Chemical Group Corp.)
• Original Assignee: Mitsubishi Plastics Incorporated (Mitsubishi Chemical Holdings Corporation)
• Inventors: Takagi, Jun, USAMI, Yasushi, Yamada, Takeyoshi
• Granted Patent: US 8,592,071 B2
• Time in Patent Office: Days
• US Class Current: 429/145
• CPC Class Codes: B32B 2264/0235 Aromatic vinyl resin, e.g. styrenic (co)polymers
• CPC Class Codes: B32B 2264/025 Acrylic resin particles, e.g. polymethyl methacrylate or ethylene-acrylate copolymers
• CPC Class Codes: B32B 2264/0257 Polyolefin particles, e.g. polyethylene or polypropylene homopolymers or ethylene-propylene copolymers
• CPC Class Codes: B32B 2264/0278 Polyester particles
• CPC Class Codes: B32B 2264/0285 PET or PBT
• CPC Class Codes: B32B 2307/306 Resistant to heat
• CPC Class Codes: B32B 2307/50 having particular mechanical properties
• CPC Class Codes: B32B 2307/518 bi-axially
• CPC Class Codes: B32B 2307/581 Resistant to cut
• CPC Class Codes: B32B 2307/5825 Tear resistant
• CPC Class Codes: B32B 2307/7246 Water vapor barrier
• CPC Class Codes: B32B 2307/732 Dimensional properties
• CPC Class Codes: B32B 2410/00 Agriculture-related articles
• CPC Class Codes: B32B 2419/04 Tiles for floors or walls tiles for roofs B32B2419/06
• CPC Class Codes: B32B 2457/00 Electrical equipment
• CPC Class Codes: B32B 2457/10 Batteries
• CPC Class Codes: B32B 2535/00 Medical equipment, e.g. bandage, prostheses, catheter medical patches B32B2556/00
• CPC Class Codes: B32B 2551/00 Optical elements
• CPC Class Codes: B32B 2607/02 Wall papers, wall coverings
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/18 : characterised by the use of special additives
• CPC Class Codes: B32B 27/20 : using fillers, pigments, thixotroping agents
• CPC Class Codes: B32B 27/32 : comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: B32B 3/26 : characterised by a particular shape of the outline of the cross-section of a continuous layer; characterised by a layer with cavities or internal voids foam layer B32B5/18; layer of synthetic resin characterised by fillers that create voids or cavities B32B27/205; characterised by an apertured layer
• CPC Class Codes: B32B 5/32 : at least two layers being foamed and next to each other
• CPC Class Codes: H01M 50/414 : Synthetic resins, e.g. thermoplastics or thermosetting resins
• CPC Class Codes: H01M 50/417 : Polyolefins
• CPC Class Codes: H01M 50/426 : Fluorocarbon polymers
• CPC Class Codes: H01M 50/451 : comprising layers of only organic material and layers containing inorganic material
• CPC Class Codes: H01M 50/491 : Porosity
• CPC Class Codes: H01M 50/494 : Tensile strength
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y10T 428/249981 : Plural void-containing components

Abstract

A laminated porous film having at least two porous layers layered one upon another. One porous layer consists of a resin layer containing a polypropylene resin. The other layer is a heat-resistant layer consisting of a resin composition whose crystal fusion peak temperature is higher than that of the resin composition of the layer containing the polypropylene resin. The laminated porous film has a β activity and/or a β crystal generation power.

Claims

1. A laminated porous film comprising:

at least two porous layers consisting of a first layer and a second layer laminated one upon another,

wherein said first layer contains a polypropylene resin; and

said second layer is a heat-resistant layer consisting of a resin composition whose crystal fusion peak temperature is higher than that of a resin composition of said first layer;

said laminated porous film having a β

activity and/or a β

crystal generation power.

3. The laminated porous film according to claim 1, wherein said second layer is made of a composition consisting of a mixed resin of said polypropylene resin and a thermoplastic resin whose crystal fusion peak temperature is not less than 170°

C.; and

in said first layer, a mixing ratio of said thermoplastic resin is lower than that in said second layer or said thermoplastic resin is not mixed with said polypropylene resin.

4. The laminated porous film according to claim 3, wherein in said second layer, a mixing mass ratio of said polypropylene resin to said thermoplastic resin is 10 to 90/90 to 10.

5. The laminated porous film according to claim 1 or 2, wherein said first layer consists of a composition containing a mixed resin of said polypropylene resin and a resin whose crystal fusion peak temperature is lower than that of said polypropylene resin and is not less than 100°

C.

6. The laminated porous film according to claim 5, wherein in said mixed resin of said first layer, a mixing mass ratio of said polypropylene resin to said resin whose crystal fusion peak temperature is not less than 100°

C. nor more than 150°

C. is 10 to 90 to 90 to 10.

7. The laminated porous film according to claim 6, wherein said resin whose crystal fusion peak temperature is not less than 100°

C. nor more than 150°

C. is polyethylene resin.

8. The laminated porous film according to claim 5, wherein a shut-down temperature at which pores of said porous layer are closed is set to a range more than 100°

C. and not more than 160°

C.

9. The laminated porous film according to claim 1, further comprising a third layer consisting of a composition whose crystal fusion peak temperature is lower than that of said composition of said first layer.

10. The laminated porous film according to claim 9, wherein said third layer contains a thermoplastic resin whose crystal fusion peak temperature is not less than 100°

C. nor more than 150°

C. and is formed as a shut-down layer having a function of closing pores at not less than 100°

C. nor more than 150°

C.

11. The laminated porous film according to claim 10, wherein said thermoplastic resin, of said third layer, whose crystal fusion peak temperature is not less than 100°

C. nor more than 150°

C. is polyethylene resin.

12. The laminated porous film according to claim 1, wherein a β

crystal nucleating agent is contained in a resin composition of said layer containing said polypropylene resin so that said layer has said β

activity and/or said β

crystal generation power.

13. The laminated porous film according to claim 1, wherein a β

crystal nucleating agent is added to said polypropylene resin so that said polypropylene resin has said β

activity and/or said β

crystal generation power.

14. The laminated porous film according to claim 1, wherein said β

crystal nucleating agent is mixed with said polypropylene resin at a ratio of 0.0001 to 5.0 parts by mass to 100 parts by mass of said polypropylene resin.

15. The laminated porous film according to claim 1, wherein said second layer contains a thermoplastic resin whose crystal fusion peak temperature is not less than 200°

C. and has a break-down temperature at not less than 200°

C. at which said laminated porous film breaks.

16. The laminated porous film according to claim 15, wherein said thermoplastic resin whose crystal fusion peak temperature is not less than 200°

C. is at least one kind of a resin selected from a group consisting of a polyester resin, a polystyrene resin, a fluorine resin, and a polymethylpentene resin.

17. The laminated porous film according to claim 1, wherein an air permeability resistance is 1 to 10000 seconds/100 ml.

18. The laminated porous film, according to claim 1, wherein a pin puncture strength is not less than 1.5N.

19. A separator for a battery comprising a laminated porous film as defined in claim 1 and having an air permeability resistance of 5 to 3000 seconds/100 ml.

20. The battery in which a separator for a battery as defined in claim 19 is incorporated.

2. A laminated porous film comprising:

at least two porous layers consisting of a first layer and a second layer laminated one upon another,

wherein said first layer contains a polypropylene resin; and

said second layer is a heat-resistant layer consisting of a resin composition containing a filler;

said laminated porous film having a β

activity and/or a β

crystal generation power.