| abstract |
One embodiment of the present invention provides a nonaqueous secondary battery separator equipped with a porous base material and an adhesive porous layer comprising resin A and resin B1. Resin A is a copolymer comprising vinylidene fluoride (VDF) and hexafluoropropylene (HFP), wherein the molar ratio of the HFP monomer unit is more than 1.5 mol% but not more than 3.5 mol% with respect to the sum molar quantity of the VDF monomer unit and the HFP monomer unit. Resin B1 is a copolymer comprising VDF, HFP, and the monomer of formula (1), wherein the molar ratio of the HFP monomer unit is more than 3.5 mol% and but not more than 15 mol% with respect to the sum molar quantity of the VDF monomer unit, HFP monomer unit, and the monomer unit represented by formula (1) (R 1 -R 3 each represent a hydrogen atom, a halogen atom, or a C1-C5 alkyl group such as a carboxyl group, X represents a single bond, a C1-C5 alkylene group, or the like, Y represents a hydrogen atom, a C1-C5 alkyl group, or the like). |