Abstract: A separator for a non-aqueous secondary battery contains: a porous layer that is provided on only one side of the porous substrate, and that contains a resin having at least one bonding group selected from an amide bond, an imide bond, and a sulfonyl bond, in which, in the porous substrate, an absolute value of a difference between a temperature of an endothermic peak observed at 120° C. to 145° C., in a temperature raising process 1, and a temperature of an endothermic peak observed at 120° C. to 145° C., in a temperature raising process 2, is 1.50° C. or higher in DSC measurement when the temperature raising process 1 of continuously raising the temperature from 30° C. to 200° C. at a temperature change rate of 5° C./min in a nitrogen atmosphere, and the temperature raising process 2 of lowering the temperature from 200° C. to 30° C. and raising the temperature from 30° C. to 200° C., are performed.

Abstract: A non-aqueous secondary battery, containing a positive electrode, a negative electrode, an insulating layer that is a single layer contacting the positive electrode on one side and the negative electrode on another side, and an electrolyte, in which (1) the insulating layer includes a polyvinylidene fluoride type resin and inorganic particles, the Mw of the polyvinylidene fluoride type resin is 900,000 to 1,500,000, and a content ratio of the inorganic particles in the insulating layer is 50% by mass to less than 90% by mass; (2) the insulating layer includes a resin and inorganic particles and has a thickness of 5 to 30 ?m, and the inorganic particles include metal sulfate particles; or (3) the insulating layer includes a polyvinylidene fluoride type resin and inorganic particles, the polyvinylidene fluoride type resin contains, as polymerizing components, vinylidene fluoride and a monomer represented by the following formula (1):

Abstract: A non-aqueous secondary battery, containing a positive electrode, a negative electrode, an insulating layer that is a single layer contacting the positive electrode on one side and the negative electrode on another side, and an electrolyte, in which (1) the insulating layer includes a polyvinylidene fluoride type resin and inorganic particles, the Mw of the polyvinylidene fluoride type resin is 900,000 to 1,500,000, and a content ratio of the inorganic particles in the insulating layer is 50% by mass to less than 90% by mass; (2) the insulating layer includes a resin and inorganic particles and has a thickness of 5 to 30 ?m, and the inorganic particles include metal sulfate particles; or (3) the insulating layer includes a polyvinylidene fluoride type resin and inorganic particles, the polyvinylidene fluoride type resin contains, as polymerizing components, vinylidene fluoride and a monomer represented by the following formula (1):

Abstract: A separator for a non-aqueous secondary battery contains: a porous layer that is provided on only one side of the porous substrate, and that contains a resin having at least one bonding group selected from an amide bond, an imide bond, and a sulfonyl bond, in which, in the porous substrate, an absolute value of a difference between a temperature of an endothermic peak observed at 120° C. to 145° C. in a temperature raising process 1, and a temperature of an endothermic peak observed at 120° C. to 145° C. in a temperature raising process 2, is 1.50° C. or higher in DSC measurement when the temperature raising process 1 of continuously raising the temperature from 30° C. to 200° C. at a temperature change rate of 5° C./min in a nitrogen atmosphere, and the temperature raising process 2 of lowering the temperature from 200° C. to 30° C. and raising the temperature from 30° C. to 200° C., are performed.