| abstract |
The present invention provides a separator for a non-aqueous secondary battery including a porous substrate, and an adhesive porous layer that is formed at one or both sides of the porous substrate, contains (1) polyvinylidene fluoride resin A and (2) polyvinylidene fluoride resin B described below, and has a porosity of from 30% to 60% and an average pore size of from 20 nm to 100 nm:n (1) polyvinylidene fluoride resin A is selected from the group consisting of vinylidene fluoride homopolymers and DVF copolymers containing structural units derived from vinylidene fluoride (VDF) and structural units derived from hexafluoropropylene (HFP), a total content of structural unit derived from HFP in each of the VDF copolymers being 1.5 mol % or less of a total content of structural unit in each of the VDF copolymers; and (2) polyvinylidene fluoride resin B selected from the group consisting of VDF copolymers containing a structural unit derived from VDF and a structural unit derived from hexafluoropropylene, a total content of structural unit derived from HFP in each of the VDF copolymers being greater than 1.5 mol % of a total content of structural unit in each of the VDF copolymers |