Patent ID: 8785032
Filing Date: 2014-07-22
Classification: B32B,C08J,C08L,H01M,Y02E,Y10T

Abstract:
1. A multilayer porous film, comprising: a coating layer, a filler, a resin binder, and a base layer comprising a porous polyolefin resin film, wherein said coating layer is laminated on at least one surface of the porous polyolefin resin film of said base layer, Du is an average particle diameter of said filler which is disposed downward from an upper surface of said coating layer composing an upper surface of said multilayer porous film and has a thickness within 25% of a thickness of said coating layer, Db is an average particle diameter of said filler which is disposed upward from an interface between said coating layer and said base layer and has a thickness within 25% of said thickness of said coating layer, a ratio of Db/Du is a value of from 1.2 to 10; and Du is not more than 0.5 μm.