LEAD-ACID BATTERY SEPARATOR AND ITS MANUFACTURE

PROBLEM TO BE SOLVED: To provide a lead-acid battery separator in which deterioration of the separator can be suppressed to prevent the early internal short-circuit at a high temperature by locally providing a part improved in oxidation resistance and electric insulating property. SOLUTION: A separator having a fine pore formed by kneading, for example, polyethylene, an inorganic powder and mineral oil into a sheet, and then extracting a prescribed quantity of mineral oil is used. The separator has a base 1b 0.25mm in thickness, and a plurality of ribs 1a vertically continued with a height of 0.75mm on the surface, and it is worked into a bag by folding in two and thermally fusing both side surfaces. The mineral oil is impregnated in 12% in this state, but the slash line part of the drawing or both surface parts 10mm of the separator 1 are further dipped in mineral oil to increase the content. A positive electrode plate 2 is housed in the inner part, and a negative electrode plate is combined thereto to form an automotive lead-acid storage battery. A battery excellent in life characteristic, compared with a one uniformly containing the mineral oil can be provided.