Abstract: The present invention provides a separator for power storage devices, the separator comprising a base material 10 which is a polyolefin microporous membrane that contains a polyolefin as a main component, and a cover layer 20 which is arranged on at least one surface of the base material 10. With respect to this separator for power storage devices, the cover layer 20 contains an inorganic filler 1 and a thermoplastic polymer; the thermoplastic polymer forms particulate polymers 2 that protrude from an inorganic filler portion L1; and the coefficient of static friction of the cover layer 20 is 0.40 to 0.60.

Abstract: Provided is a multilayered porous membrane that comprises a porous membrane containing polyolefin resin as the main component thereof, and that comprises a porous layer layered on at least one surface of the porous membrane and containing inorganic particles and a binder polymer. The total thickness of the porous layer is 0.5-3.0 ?m; the number of pores in the porous layer having an area for the individual pore of at least 0.001 ?m2 is 65-180 per 10 ?m2 of the field of observation; of the pores in the porous layer that have an area of at least 0.001 ?m2, the proportion therein of pores in the range from 0.001 ?m2 to 0.05 ?m2 is at least 90%; the proportion taken up by the inorganic particles in the porous layer is from 90-99 mass %; and the aspect ratio of the inorganic particles is from 1.0-3.0.

Abstract: A separator for an electricity storage device, including: a layer (A) containing a polyolefin; and a layer (B) disposed on at least one surface of the layer (A) and containing an inorganic filler, a water-insoluble binder, a water-soluble binder, and a polyacrylic acid-based dispersant, wherein a heat shrinkage rate S1 of the separator for the electricity storage device at 140° ° C. in propylene carbonate is 5% or less.

Abstract: Provided is a multilayered porous membrane that comprises a porous membrane containing polyolefin resin as the main component thereof, and that comprises a porous layer layered on at least one surface of the porous membrane and containing inorganic particles and a binder polymer. The total thickness of the porous layer is 0.5-3.0 ?m; the number of pores in the porous layer having an area for the individual pore of at least 0.001 ?m2 is 65-180 per 10 ?m2 of the field of observation; of the pores in the porous layer that have an area of at least 0.001 ?m2, the proportion therein of pores in the range from 0.001 ?m2 to 0.05 ?m2 is at least 90%; the proportion taken up by the inorganic particles in the porous layer is from 90-99 mass %; and the aspect ratio of the inorganic particles is from 1.0-3.0.

Abstract: This separator for electricity storage devices comprises a porous base and a thermoplastic polymer layer that is arranged in at least a part of the outermost surface of at least one surface of the porous base, and wherein: a thermoplastic polymer contained in the thermoplastic polymer layer contains a copolymer that has, as a monomer unit, an ethylenically unsaturated monomer (P) having a polyalkylene glycol group; and the thermoplastic polymer layer contains the thermoplastic polymer in an amount of more than 3% by mass but 100% by mass or less if the thermoplastic polymer layer is taken as 100% by mass.

Abstract: This separator for electricity storage devices comprises a porous base and a thermoplastic polymer layer that is arranged in at least a part of the outermost surface of at least one surface of the porous base, and wherein: a thermoplastic polymer contained in the thermoplastic polymer layer contains a copolymer that has, as a monomer unit, an ethylenically unsaturated monomer (P) having a polyalkylene glycol group; and the thermoplastic polymer layer contains the thermoplastic polymer in an amount of more than 3% by mass but 100% by mass or less if the thermoplastic polymer layer is taken as 100% by mass.

Abstract: Methylmethioninesulfonium compounds of the formula ##STR1## wherein X.crclbar. represents an anion;R.sup.1 represents a hydrogen atom or an acyl group of the formula -COR.sup.3 in which R.sup.3 represents an alkyl group with 1 to 20 carbon atoms, the group --CH.sub.2).sub.2 COOH or the group ##STR2## in which Z represents a direct bond or a methylene or vinylene linkage, Y represents C or N, R.sup.4 represents a member selected from the class consisting of a hydrogen atom, lower alkyl groups, lower alkoxy groups, di-lower-alkylamino groups and a sulfamoyl group, n is a number of 1 to 3, and two or more R.sup.4 groups may be identical or different; andR.sup.2 represents the group --COOR.sup.5 in which R.sup.5 represents a hydrogen atom, an alkyl group with 1 to 5 carbon atoms or a metal- or metal complex-forming moiety, or the group ##STR3## in which R.sup.6 groups may be identical or different, and each represent a hydrogen atom or an alkyl group with 1 to 5 carbon atoms, with the proviso that when R.sup.