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: A tetrahydroxanthone derivative represented by the general formula: ##STR1## wherein R is a hydrogen atom, a hydroxyl, cyano, lower alkyl, lower alkoxy, lower acyloxy, benzoyloxy or tetrazolyl group, or ##STR2## (R.sub.3 is a hydrogen atom, R.sub.4 is a hydrogen atom, a phenyl group which may be optionally substituted, or a tetrazolyl group; or R.sub.3 and R.sub.4 commonly form a ring together with the adjacent nitrogen atom and another nitrogen atom or an oxygen atom); R.sub.1 is a hydrogen or halogen atom, a lower alkyl, cyano, carboxyl or tetrazolyl group, or ##STR3## (R.sub.5 is a hydrogen atom, R.sub.6 is a phenyl group which may be optionally substituted, or a tetrazolyl group; or R.sub.5 and R.sub.6 commonly form a ring together with the adjacent nitrogen atom and an oxygen atom); and R.sub.2 is a hydrogen or halogen atom, or a lower alkyl group; with the proviso that neither R nor R.sub.1 is a hydrogen atom; when R is --CONH.sub.2, R.sub.1 and R.sub.

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.