Polyolefin micro porous film, separator film for power-storage device, and power-storage device

Patent metadata

Field	Value
Publication number	US-2018175353-A1
Application number	US-201615735057-A
Country	US
Kind code	A1
Filing date	Jun 17, 2016
Priority date	Jun 19, 2015
Publication date	Jun 21, 2018
Grant date	—

Abstract

A polyolefin micro porous film includes at least one of polyethylene and polypropylene, in which the compressive elastic modulus is 95 MPa or more and 150 MPa or less, the surface roughness (Ra) of a film surface is measured for a front surface and a rear surface, and the average value (Ra(ave)) thereof is 0.01 μm to 0.30 μm.

First claim

1 . A polyolefin micro porous film having:
a compressive elastic modulus is 95 MPa or more and 150 MPa or less, and an average value (Ra(ave)) of a surface roughness (Ra) of a film surface measured at a front surface and a rear surface of substantially 0.30 μm or less.

2 . The polyolefin micro porous film according to claim 1 , wherein, after a pressure of 17.3 MPa is applied thereto, a Gurley value obtained when the pressure is released is higher than a Gurley value obtained before the pressure is applied thereto, and its increase rate of the Gurley value is 0.5% or more and 29.0% or less.

3 . The polyolefin micro porous film according to claim 1 , wherein, after a pressure of 11.5 MPa is applied thereto, a Gurley value obtained when the pressure is released is higher than a Gurley value obtained before the pressure is applied thereto, and its increase rate of the Gurley value is 0.05% or more and 6.0% or less.

4 . The polyolefin micro porous film according to claim 1 , wherein, an amount of strain in a stress-strain curve in a compression direction obtained when 2.7 MPa is applied thereto is 0.010 to 0.055.

5 . The polyolefin micro porous film according to claim 1 , wherein a thermal shrinkage ratio in a TD direction is −1.0% to 1.0%, and a thermal shrinkage ratio in an MD direction is 0.5% to 8.0%.

6 . The polyolefin micro porous film according to claim 1 , wherein the polyolefin is at least one of polyethylene and polypropylene, and
the average value (Ra(ave)) of the surface roughness (Ra) is 0.01 μm to 0.30 μm.

7 . The polyolefin micro porous film according to claim 6 , wherein the polypropylene layer and a polyethylene layer are laminated.

8 . The polyolefin micro porous film according to claim 7 , wherein the polypropylene layers are provided on both surfaces of the polyethylene layer.

9 . The polyolefin micro porous film according to claim 8 , wherein a shutdown temperature is 130° C. to 140° C., and a meltdown temperature is 175° C. or higher and 190° C. or lower.

10 . The polyolefin micro porous film according to claim 9 , wherein a Gurley value is 100 to 600 sec/100 cc, a film thickness is 10 to 40 μm, a puncture strength is 200 to 700 gf, and a maximal pore diameter by a mercury porosimeter is in a range of 0.05 to 0.3 pun.

11 . The polyolefin micro porous film according to claim 1 , wherein a heat-resistant porous layer primarily containing heat-resistant fine particles and containing a resin binder is provided on the polyolefin micro porous film.

12 . A separator film for a power-storage device using the polyolefin micro porous film according to claim 1 .

13 . A power-storage device comprising:
a positive electrode; a negative electrode; the polyolefin micro porous film according to claim 1 interposed between the positive electrode and the negative electrode; and a nonaqueous electrolyte with which the polyolefin micro porous film is impregnated, wherein a resistance value obtained by DC-R measurement performed by applying a pressure of 2.7 MPa is 100.1% to 105.0% when a resistance value obtained before the pressure is applied is assumed to be 100%.

Assignees

• Ube Industries

Inventors

• Sakimoto Ryo
• Kawabata Kenji
• NAGUMO Hiroki
• Adachi Taiga

Classifications

• B32B3/26

  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 title

• B32B2250/04

  4 layers · CPC title

• B32B2307/732

  Dimensional properties · CPC title

• B32B2307/42

  Polarizing, birefringent, filtering · CPC title

• B32B27/20 Primary

  using fillers, pigments, thixotroping agents · CPC title