Polyolefin microporous membrane and separator for nonaqueous electrolyte battery

Patent metadata

Field	Value
Publication number	US-2016181584-A1
Application number	US-201615055353-A
Country	US
Kind code	A1
Filing date	Feb 26, 2016
Priority date	Sep 20, 2006
Publication date	Jun 23, 2016
Grant date	—

Abstract

The present invention provides a polyolefin microporous membrane made of a polyolefin resin and an inorganic particle, and the puncture strength of the microporous membrane is 3 N/20 μm or more and the membrane thickness retention ratio in penetration creep is 16% or more, thereby being excellent in safety and long-term reliability, and a separator for a nonaqueous electrolyte battery, and the like can be provided.

First claim

1 - 20 . (canceled)

21 . A polyolefin microporous membrane, comprising a polyolefin resin and inorganic particles,
wherein the microporous membrane has a puncture strength of 3 N/20 μm or more, a membrane thickness retention ratio in penetration creep of 20% or more, and a membrane thickness reduction rate in penetration creep of 10% or less, wherein a content of the inorganic particles is 20% by mass or more and less than 60% by mass, wherein a particle diameter of the inorganic particles is 1 nm or more and less than 100 nm, and wherein the polyolefin resin comprises a composition containing polypropylene, and the polypropylene is contained in an amount of 1% by weight or more and less than 50% by weight in 100% by weight of the polyolefin resin.

22 . The polyolefin microporous membrane according to claim 21 , wherein the polypropylene is contained in an amount of 5% by weight or more and less than 40% by weight in 100% by weight of the polyolefin resin.

23 . The polyolefin microporous membrane according to claim 21 , wherein the polypropylene is contained in an amount of 20% by weight or more and less than 40% by weight in 100% by weight of the polyolefin resin.

24 . The polyolefin microporous membrane according to claim 21 , wherein the inorganic particles comprise one, or two or more kinds selected from oxides and nitrides of silicon, aluminum and titanium, and carbonates and sulfates of calcium and barium.

25 . The polyolefin microporous membrane according to claim 21 , wherein inorganic particles having a hydrophilic group and inorganic particles subjected to a hydrophobic treatment are used in combination as the inorganic particles.

26 . The polyolefin microporous membrane according to claim 25 , wherein the inorganic particles having a hydrophilic group in a proportion of 1% by weight or more and less than 50% by weight of all inorganic particles and the inorganic particles subjected to a hydrophobic treatment in a proportion of 50% by weight or more and less than 99% by weight of all inorganic particles are used in combination.

27 . The polyolefin microporous membrane according to claim 21 , wherein a viscosity average molecular weight of the microporous membrane is 50,000 or more and less than 10,000,000.

28 . The polyolefin microporous membrane according to claim 21 , wherein a viscosity average molecular weight of the microporous membrane is 50,000 or more and 500,000 or less.

29 . The polyolefin microporous membrane according to claim 21 , wherein a viscosity average molecular weight of the microporous membrane is more than 500,000 and less than 2,000,000.

30 . A separator for a nonaqueous electrolyte battery, comprising the polyolefin microporous membrane according to claim 21 .

31 . A lithium ion secondary battery containing a polyolefin microporous membrane according to claim 21 .

32 . A lithium ion secondary battery for a hybrid automobile comprising the polyolefin microporous membrane according to claim 21 .

Assignees

• Asahi Kasei Chemicals Corp

Inventors

• Hatayama Hiroshi
• Sogo Hiroshi

Classifications

• C08J2323/00

  Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title

• C08J5/18 Primary

  Manufacture of films or sheets · CPC title

• H01M50/417

  Polyolefins · CPC title