Porous Membrane and Multilayer Porous Membrane

• US 20170194613A1
• Filed: 03/17/2017
• Published: 07/06/2017
• Est. Priority Date: 03/28/2012
• Status: Active Grant

• Current Assignee: Asahi Kasei E-materials Corporation (Asahi Kasei Corporation)
• Original Assignee: Asahi Kasei E-materials Corporation (Asahi Kasei Corporation)
• Inventors: Ishikawa, Masaki, Murata, Hiroshi, Hatayama, Hiroshi, Uchida, Yuki
• Granted Patent: US 9,911,960 B2
• Time in Patent Office: Days
• CPC Class Codes: B32B 2255/10 on synthetic resin layer or on natural or synthetic rubber layer
• CPC Class Codes: B32B 2255/26 Polymeric coating
• CPC Class Codes: B32B 2264/102 Oxide or hydroxide
• CPC Class Codes: B32B 2307/306 Resistant to heat
• CPC Class Codes: B32B 2307/518 bi-axially
• CPC Class Codes: B32B 2307/724 Permeability to gases, adsorption
• CPC Class Codes: B32B 2457/10 Batteries
• CPC Class Codes: B32B 27/08 of synthetic resin
• 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: C08J 2323/06 Polyethene
• CPC Class Codes: C08J 2323/16 Ethene-propene or ethene-propene-diene copolymers
• CPC Class Codes: C08J 2423/10 Homopolymers or copolymers of propene
• CPC Class Codes: C08J 5/18 Manufacture of films or sheets
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 2220/30 Batteries in portable systems, e.g. mobile phone, laptop
• CPC Class Codes: H01M 50/403 Manufacturing processes of separators, membranes or diaphragms
• CPC Class Codes: H01M 50/406 Moulding; Embossing; Cutting
• CPC Class Codes: H01M 50/417 Polyolefins
• CPC Class Codes: H01M 50/42 : Acrylic resins
• CPC Class Codes: H01M 50/423 : Polyamide resins
• CPC Class Codes: H01M 50/426 : Fluorocarbon polymers
• CPC Class Codes: H01M 50/429 : Natural polymers
• CPC Class Codes: H01M 50/446 : Composite material consisting of a mixture of organic and inorganic materials
• 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: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02E 60/13 : Energy storage using capacitors

Abstract

A multilayer porous membrane comprising: a porous membrane containing a polyolefin resin as a main component; and a porous layer containing an inorganic filler and a resin binder and laminated on at least one surface of the porous membrane;

• • wherein the porous membrane has an average pore size d=0.035 to 0.060 μm, a tortuosity τ_a=1.1 to 1.7, and the number B of pores=100 to 500 pores/μm², which are calculated by a gas-liquid method, and the porous membrane has a membrane thickness L=5 to 22 μm.

Claims

1-11. -11. (canceled)

12. A separator for nonaqueous electrolyte batteries comprising:

a porous membrane (A) comprising a polyolefin resin as a main component; and

a porous layer (B) comprising an inorganic filler and a resin binder, where the porous layer is laminated on at least one surface of the porous membrane (A);

wherein the porous membrane (A) has a porosity of not less than 50% and not more than 90%, and a number of pores of not less than 100 pores/μ

m² and not more than 500 pores/μ

m², and

wherein the resin binder present in the porous layer (B) is a resin latex binder having an average particle size of not less than 50 nm and not more than 500 nm.

14. A nonaqueous electrolyte battery, comprising:

the separator for nonaqueous electrolyte batteries according to claim 12,

a positive electrode,

a negative electrode, and

an electrolytic solution.

15. The separator for nonaqueous electrolyte batteries according to claim 12, wherein the polyolefin composition comprises polypropylene and a polyolefin other than the polypropylene.

16. The separator for nonaqueous electrolyte batteries according to claim 12, wherein a proportion of polypropylene based on total polyolefin present in the resin is 1 to 35% by mass.

17. The separator for nonaqueous electrolyte batteries according to claim 12, wherein a viscosity average molecular weight of the polyolefin resin is not less than 50,000 and less than 2,000,000.

13. (canceled)