Abstract: Provided is a laminated separator which makes it possible to reduce occurrence of adhesion of separators. A laminated separator (4a) has a heat-resistant layer (2a, 2b) on one surface or both surfaces of a polyolefin-based base material (1), the laminated separator including a particle layer (3a, 3b) on at least one side of the laminated separator, particles contained in the particle layer containing a thermoplastic resin, an average particle diameter of the particles being not less than 0.1 ?m and less than 3.0 ?m, and the heat-resistant layer containing an inorganic filler at a proportion of not more than 70% by weight.

Abstract: Provided is a nonaqueous electrolyte secondary battery laminated separator which achieves both of voltage resistance and ion permeability. A nonaqueous electrolyte secondary battery laminated separator (4a) having a heat-resistant layer (2a, 2b) on one surface or both surfaces of a polyolefin-based base material (1) includes a particle layer (3a, 3b) on at least one side of the laminated separator, the particle layer containing particles having an average particle diameter of 3 ?m to 10 ?m, and the particle layer having a weight per unit area per layer of 0.1 g/m2 to 1.0 g/m2.

Abstract: As a nonaqueous electrolyte secondary battery separator which has improved mechanical strength and which retains flexibility, provided is a nonaqueous electrolyte secondary battery separator including: a mixed layer which contains a heat-resistant resin and a porous base material that includes a porous film containing a polyolefin-based resin as a main component; and a heat-resistant layer which contains the heat-resistant resin and which is in contact with the mixed layer. When an SEM image which includes a cross section of the nonaqueous electrolyte secondary battery separator in a thickness direction is analyzed, luminance distribution of the mixed layer in the thickness direction satisfies specific conditions.

Abstract: As a nonaqueous electrolyte secondary battery separator which has excellent heat resistance and excellent battery performance, provided is a nonaqueous electrolyte secondary battery separator including a mixed layer which contains a heat-resistant resin and a porous base material that includes a polyolefin porous film, in the mixed layer, a weight ratio (W1/W0) between a weight W1 of the heat-resistant resin and a weight W0 of the porous base material being not less than 0.07.

Abstract: As a nonaqueous electrolyte secondary battery separator which has improved mechanical strength and which retains flexibility, provided is a nonaqueous electrolyte secondary battery separator containing a heat-resistant resin that contains N (nitrogen) and a porous base material that includes a porous film containing a polyolefin-based resin as a main component. A ratio of N2 to N1 is not less than 50% and not more than 80%, where N1 is a proportion of N (nitrogen) present when an energy dispersive X-ray analysis is carried out at an acceleration voltage of 1.5 kV and N2 is a proportion of N (nitrogen) present when an energy dispersive X-ray analysis is carried out at an acceleration voltage of 5.0 kV.

Abstract: As a nonaqueous electrolyte secondary battery separator which has excellent heat resistance and excellent voltage withstand characteristics, provided is a separator including a mixed layer which contains a heat-resistant resin and a porous base material that includes a polyolefin porous film. When attenuated total reflection infrared spectroscopy is carried out with respect to an opposite surface of the separator, a ratio between an intensity of a peak indicating the heat-resistant resin and an intensity of a peak indicating the polyolefin-based resin is not less than 0.02.

Abstract: Provided is a nonaqueous electrolyte secondary battery porous layer which has both high-voltage resistance and adhesiveness. The nonaqueous electrolyte secondary battery porous layer contains: a block copolymer; and a filler, the block copolymer having: a block A containing, as a main component, units each represented by “—(NH—Ar1—O—NHCO—Ar2—CO)—”; and a block B containing, as a main component, units each represented by “—(NH—Ar313 NHCO—Ar4—CO—)—”. Not less than 50% of all Ar1 each have a structure in which two aromatic rings are connected by a sulfonyl bond. Not more than 50% of all Ar3 each have a structure in which two aromatic rings are connected by a sulfonyl bond. 30% to 70% of all Ar1 and Ar3 each have a structure in which two aromatic rings are connected by a sulfonyl bond.

Abstract: A nonaqueous electrolyte secondary battery porous layer which has both high-voltage resistance and adhesiveness is provided. The nonaqueous electrolyte secondary battery porous layer contains a resin A, a resin B, and a filler. The resin A has a structure in which a plurality of aromatic rings are connected by chemical bonds, at least some of the chemical bonds being amide bonds, at least some of the chemical bonds being sulfonyl bonds. The resin B is a nitrogen-containing aromatic polymer. The nonaqueous electrolyte secondary battery porous layer contains the resin A in an amount of 20 parts by weight to 80 parts by weight, when a total amount of the resin A and the resin B is regarded as 100 parts by weight.

Abstract: A nonaqueous electrolyte secondary battery laminated body is provided in which a porous layer is less likely to be broken even when an external force is applied when the nonaqueous electrolyte secondary battery laminated body is present in a battery. The nonaqueous electrolyte secondary battery laminated body is such that a peel strength between a first electrode plate and an outermost surface layer of a nonaqueous electrolyte secondary battery laminated separator is lower than a peel strength between a porous layer and a polyolefin porous film when the nonaqueous electrolyte secondary battery laminated body has been subjected to Peeling Test A. Step 1A: A nonaqueous electrolyte secondary battery laminated body is immersed in a predetermined solvent. Step 2A: The first electrode plate is fixed on a substrate. Step 3A: The nonaqueous electrolyte secondary battery laminated separator is peeled off under a predetermined condition.