Abstract: There is provided a low-cost alkaline storage battery separator capable of implementing stable fiber spinning and excellent ammonia trapping function so as to control self-discharge. Spinning fiber using resin including 1.0 mass % or greater of low crystalline polyolefin, crystalline polyolefin and maleic anhydride-modified polyolefin corresponding to a maleic anhydride component content of 3.5 to 35 mass % in the fiber assures stability during fiber spinning. Moreover, making a nonwoven fabric using the fiber act as a separator allows a high level of ammonia trapping function and controls self-discharge of the alkaline storage battery.

Abstract: A separator paper is provided which simultaneously satisfies the requirements to have a high denseness that can prevent internal shortage due to such as the deposition of the zinc oxide dendrite accompanied by not adding mercury, and a high liquid impregnate properties that can improve heavy discharging properties.