Abstract: According to the present disclosure, a resin raw material composition comprising resin pellets, a powder and a liquid component is provided. The resin raw material composition is a resin raw material composition for molding use or a resin raw material composition for microporous membranes. The resin raw material composition comprises granular bodies in each of which the liquid component is coated on at least a portion of the surface of each of the resin pellets and the powder is adhered to the liquid component.

Abstract: The purpose of the present disclosure is to provide: a safer polyolefin microporous membrane; an electricity storage device separator, electricity storage device assembly kit, and electricity storage device using the polyolefin microporous membrane; and an electricity storage device. In one embodiment, the polyolefin microporous membrane comprises at least one of each of a layer A and a layer B, a polyolefin contained in at least one of the layer A and the layer B has one or more types of functional groups, and a crosslinked structure is formed by (1) the functional groups undergoing condensation reactions with each other, (2) the functional group reacting with a chemical substance inside the electricity storage device, or (3) the functional group reacting with a different type of functional group, after accommodation in the electricity storage device.

Abstract: Provided is a method for producing a separator for a power storage device, the method including: a step for extruding powdered polyethylene, pelletized polypropylene, and a plasticizer into a sheet form using an extruder to form a molded body; and a step for making the molded body porous by a wet method.