BATTERY SEPARATOR AND ITS MANUFACTURE

摘要

PURPOSE:To improve gas absorptiveness at the time of charging a sealed battery and enhance the self-charging property by using as separator a porous substance formed by placing a polyvinyl alcohol film over the surface of a polyolefin fiber. CONSTITUTION:A porous substance is used which is formed by coating polyvinyl alcohol over the surface of polyolefin fiber. Therein the polyvinyl alcohol does not form a film as in a conventional arrangement, but merely covers surfaces of the polyolefin fiber itself. Accordingly inclusion of polyvinyl alcohol still allows keeping of porosity for passage of gas This provides separators for sealed type alkaline battery at low cost wherein possible drop of gas absorption characteristic due to too large electrolyte retaining capacity is suppressed in the early period while the porous body consisting of polyolefin maintains its resistance against electrolyte, and in a long-term view the charging/discharging characteristic is prevented from deterioration.