MULTILAYER POROUS FILM, SEPARATOR FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERIES, AND NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

摘要

Provided is a multilayer porous film which has extremely high particle fall-off resistance without lowering high air permeability of porous films, and also has excellent electrolyte solution adsorption and excellent heat resistance. This multilayer porous film exhibits excellent characteristics when used as a separator for batteries. A multilayer porous film which has a coating layer that contains a filler and a resin binder on at least one surface of a polyolefin-based resin porous film. This multilayer porous film is characterized in that: the amount of particles having a particle diameter of less than 0.2 mum (D0.2) in the filler is 1% or more; the filler has a specific surface area of 5 m2/g or more but less than 10 m2/g; and the multilayer porous film satisfies a specific condition.