Patent ID: 9142816
Filing Date: 2015-09-22
Classification: H01M,Y02E

Abstract:
1. An alkaline battery separator, comprising: a coarse layer comprising a first alkaline-resistant synthetic fiber, a first alkaline-resistant binder fiber, and at least two kinds of first alkaline-resistant cellulose fibers having different freeness values from each other; and a dense layer comprising a second alkaline-resistant synthetic fiber, a second alkaline-resistant binder fiber, and a second alkaline-resistant cellulose fiber wherein the coarse layer comprises the at least two kinds of the first alkaline-resistant cellulose fibers in a proportion of from 25 to 65% by weight of the coarse layer, the at least two kinds of the first alkaline-resistant cellulose fibers, as a whole, have a freeness value of from 350 to 650 ml, a difference in freeness values between one of the at least two kinds of the first alkaline-resistant cellulose fibers having a highest freeness value and one of the at least two kinds of the first alkaline-resistant cellulose fibers having a lowest freeness value is from 300 to 700 ml, the dense layer is denser than the coarse layer, the second alkaline-resistant cellulose fiber has, as a whole, a freeness value of from 0 to 400 ml, the alkaline battery separator has a maximum pore size of 65 μm or smaller and a liquid absorption capacity of 5 g/g or higher, and a difference in freeness values between the whole freeness value of the first alkaline-resistant cellulose fiber and the whole freeness value of the second alkaline-resistant cellulose fiber is from 100 to 450 ml.