Heat-resistant synthetic resin microporous film, separator for non-aqueous liquid electrolyte secondary battery, non-aqueous liquid electrolyte secondary battery, and method for producing heat-resistant synthetic resin microporous film

Patent metadata

Field	Value
Publication number	US-2017012265-A1
Application number	US-201515121100-A
Country	US
Kind code	A1
Filing date	Mar 5, 2015
Priority date	Mar 18, 2014
Publication date	Jan 12, 2017
Grant date	—

Abstract

Provided are a heat-resistant synthetic resin microporous film having enhanced heat resistance while having reduced deterioration of mechanical strength, and a method for producing the same. Disclosed is a heat-resistant synthetic resin microporous film which includes a synthetic resin microporous film containing a synthetic resin; and a coating layer formed on at least a portion of the surface of the synthetic resin microporous film and containing a polymer of a polymerizable compound having a bifunctional or higher-functional radical polymerizable functional group, the heat-resistant synthetic resin microporous film having a surface aperture ratio of 30% to 55%, gas permeability of 50 sec/100 mL to 600 sec/100 mL, a maximum thermal shrinkage obtainable when the film is heated from 25° C. to 180° C. at a rate of temperature increase of 5° C./min, of 20% or less, and a piercing strength of 0.7 N or more.

First claim

1 . A heat-resistant synthetic resin microporous film comprising:
a synthetic resin microporous film containing a synthetic resin; and a coating layer formed on at least a portion of the surface of the synthetic resin microporous film and containing a polymer of a polymerizable compound having a bifunctional or higher-functional radical polymerizable functional group, the heat-resistant synthetic resin microporous film having a surface aperture ratio of 30% to 55%; gas permeability of 50 sec/100 mL to 600 sec/100 mL; a maximum thermal shrinkage obtainable when the film is heated from 25° C. to 180° C. at a rate of temperature increase of 5° C./min, of 20% or less; and a piercing strength of 0.7 N or more.

2 . The heat-resistant synthetic resin microporous film according to claim 1 , wherein the piercing strength is 1.0 N or more.

3 . The heat-resistant synthetic resin microporous film according to claim 1 , wherein the polymerizable compound is at least one selected from the group consisting of a polyfunctional (meth)acrylate modification product, a dendritic polymer having bifunctional or higher-functional (meth)acryloyl groups, and a urethane (meth)acrylate oligomer having a bifunctional or higher-functional (meth)acryloyl group.

4 . A heat-resistant synthetic resin microporous film comprising:
a synthetic resin microporous film containing a synthetic resin; and a coating layer formed on at least a portion of the surface of the synthetic resin microporous film and containing a polymer of a polymerizable compound having a bifunctional or higher-functional radical polymerizable functional group, the polymerizable compound being at least one selected from the group consisting of a polyfunctional (meth)acrylate modification product, a dendritic polymer having bifunctional or higher-functional (meth)acryloyl groups, and a urethane (meth)acrylate oligomer having a bifunctional or higher-functional (meth)acryloyl group, the heat-resistant synthetic resin microporous film having a surface aperture ratio of 30% to 55%; gas permeability of 50 sec/100 mL to 600 sec/100 mL; and a maximum thermal shrinkage obtainable when the film is heated from 25° C. to 180° C. at a rate of temperature increase of 5° C./min, of 20% or less.

5 . The heat-resistant synthetic resin microporous film according to claim 1 , wherein the coating layer contains a polymer obtained by polymerizing the polymerizable compound having a bifunctional or higher-functional radical polymerizable functional group by irradiation of active energy radiation.

6 . The heat-resistant synthetic resin microporous film according to claim 1 , wherein the gel fraction is 5% by weight or more.

7 . The heat-resistant synthetic resin microporous film according to claim 1 , wherein the synthetic resin includes a propylene-based resin.

8 . A separator for a non-aqueous liquid electrolyte secondary battery, comprising the heat-resistant synthetic resin microporous film according to claim 1 .

9 . A non-aqueous liquid electrolyte secondary battery comprising the separator for a non-aqueous liquid electrolyte secondary battery according to claim 8 .

10 . A method for producing a heat-resistant synthetic resin microporous film, the method comprising coating at least a portion of the surface of a synthetic resin microporous film containing a synthetic resin with a polymerizable compound having a bifunctional or higher-functional radical polymerizable functional group, and then irradiating the synthetic resin microporous film with active energy radiation.

11 . The method for producing a heat-resistant synthetic resin microporous film according to claim 10 , wherein the polymerizable compound is at least one selected from the group consisting of a polyfunctional (meth)acrylate modification product, a dendritic polymer having a bifunctional or higher-functional (meth)acryloyl group, and a urethane (meth)acrylate oligomer having a bifunctional or higher-functional (meth)acryloyl group.

Assignees

• Sekisui Chemical Co Ltd

Inventors

• NAKADATE Junichi
• Sawada Takahiko
• Tada Hiroshi
• Sakurai Yuki
• Cho Taehyung

Classifications

• C08J7/0427

  with only one layer of a composition containing a polymer binder (with more layers C08J7/042) · CPC title

• C08J7/123

  Treatment by wave energy or particle radiation (C08J7/18 takes precedence) · CPC title

• H01M10/0525

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

• B32B2307/308

  Heat stability · CPC title

• B32B2307/50

  having particular mechanical properties · CPC title