Porous Membrane and Multilayer Porous Membrane

Patent metadata

Field	Value
Publication number	US-2017194612-A1
Application number	US-201715462790-A
Country	US
Kind code	A1
Filing date	Mar 17, 2017
Priority date	Mar 28, 2012
Publication date	Jul 6, 2017
Grant date	—

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/μm 2 , which are calculated by a gas-liquid method, and the porous membrane has a membrane thickness L=5 to 22 μm.

First claim

1 . A separator for nonaqueous electrolyte batteries comprising:
a porous membrane comprising a polyolefin resin as a main component; and a porous layer comprising an inorganic filler and a resin binder, where the porous layer is 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 a number B of pores equal to 100 to 500 pores/μm 2 , and wherein the inorganic filler is present in the porous layer in a proportion of not less than 50% and less than 100% by mass.

2 . The separator for nonaqueous electrolyte batteries according to claim 1 , wherein the porous membrane has a porosity ε=of 50 to 90%.

3 . The separator for nonaqueous electrolyte batteries according to claim 1 , wherein the polyolefin resin composition comprises polypropylene and a polyolefin other than the polypropylene.

4 . The separator for nonaqueous according to claim 3 , wherein a proportion of the polypropylene based on total polyolefin in the resin composition is 1 to 35% by mass.

5 . A separator for nonaqueous electrolyte batteries comprising the multilayer porous membrane according to claim 1 .

6 . A nonaqueous electrolyte battery, comprising:
the separator for nonaqueous electrolyte batteries according to claim 5 , a positive electrode, a negative electrode, and an electrolytic solution.

7 - 14 . (canceled)

Assignees

• Asahi Kasei E Materials Corp

Inventors

• Murata Hiroshi
• Hatayama Hiroshi
• Uchida Yuki
• Ishikawa Masaki

Classifications

• B32B27/32 Primary

  comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)} · CPC title

• B32B2457/10

  Batteries · CPC title

• B32B2307/724

  Permeability to gases, adsorption · CPC title

• B32B27/20

  using fillers, pigments, thixotroping agents · CPC title

• C08J2323/16

  Ethene-propene or ethene-propene-diene copolymers · CPC title