Abstract: An alkaline battery separator containing an alkali resistant fiber and a binder, wherein the alkaline battery separator has two surfaces which are a surface A that is smoother comparing with the other surface and has an arithmetic mean surface roughness Ra (A), and a surface B that is rougher and has an arithmetic mean surface roughness Ra (B), the amount of the binder is 5 to 20% by mass based on the total mass of the separator, a value obtained by dividing the arithmetic mean surface roughness Ra (A) by the arithmetic mean surface roughness Ra (B) [Ra (A)/Ra (B)] is 0.700 or more and 0.980 or less, and the arithmetic mean surface roughness Ra (B) of the surface B is 3.0 ?m or more and 10 ?m or less.

Abstract: Provided is a space filling material having excellent strength in reinforcing a predetermined space to be filled with the space filling material and/or strength in fixing a material to be fixed therewith. The space filling material (11) includes reinforcing fibers and a thermoplastic resin, wherein the reinforcing fibers form a plurality of intersections at least a part of which are bonded with the thermoplastic resin, and among all of the reinforcing fibers, a proportion in volume of reinforcing fibers each having a bent ratio of 1.004 or higher is 20 vol % or more relative to a total volume of the reinforcing fibers, the bent ratio being defined as a ratio of fiber length/shortest distance between opposite ends of fiber. The space filling material (11) expands to fill a predetermined space (13) when the thermoplastic resin is softened by heating to release bending loads of the reinforcing fibers.

Abstract: An alkaline battery separator containing an alkali resistant fiber and a binder, wherein the alkaline battery separator has two surfaces which are a surface A that is smoother comparing with the other surface and has an arithmetic mean surface roughness Ra (A), and a surface B that is rougher and has an arithmetic mean surface roughness Ra (B), the amount of the binder is 5 to 20% by mass based on the total mass of the separator, a value obtained by dividing the arithmetic mean surface roughness Ra (A) by the arithmetic mean surface roughness Ra (B) [Ra (A)/Ra (B)] is 0.700 or more and 0.980 or less, and the arithmetic mean surface roughness Ra (B) of the surface B is 3.0 ?m or more and 10 ?m or less.