Abstract: Provided is a separator for a non-aqueous secondary battery, the separator contains a porous substrate and an adhesive porous layer that is provided on one side or on both sides of the porous substrate, and that contains a polyvinylidene fluoride type resin and a filler, in which a volume ratio of the filler in the adhesive porous layer excluding pores is from 30% by volume to 67% by volume, and when differential scanning calorimetry is performed with all of the polyvinylidene fluoride type resin contained in the adhesive porous layer as a sample, two or more endothermic peaks and/or two or more exothermic peaks are observed.

Abstract: Provided is a separator for a non-aqueous secondary battery, the separator contains a porous substrate and an adhesive porous layer that is provided on one side or on both sides of the porous substrate, and that contains a polyvinylidene fluoride type resin and a filler, in which the porous substrate contains a fluorine atom, and when differential scanning calorimetry is performed with all of the polyvinylidene fluoride type resin contained in the adhesive porous layer as a sample, two or more endothermic peaks and/or two or more exothermic peaks are observed.

Abstract: Provided is a separator for a non-aqueous secondary battery, the separator contains a porous substrate and an adhesive porous layer that is provided on one side or on both sides of the porous substrate, and that contains a polyvinylidene fluoride type resin and an inorganic filler, in which an average primary particle size of all of the inorganic filler contained in the adhesive porous layer is from 0.01 ?m to less than 0.50 ?m, and when differential scanning calorimetry is performed with all of the polyvinylidene fluoride type resin contained in the adhesive porous layer as a sample, two or more endothermic peaks and/or two or more exothermic peaks are observed.