| 摘要 |
PROBLEM TO BE SOLVED: To effectively prevent an internals short circuit, reduce the number of laminating sheets of separator paper, and increase battery capacity by including alkali resistant cellulose fiber by wt.% of a specific range, beating it in a free shape in which a beating degree is a specific range ml in an CSF value, and applying it to paper manufacture mixing with synthetic fiber. SOLUTION: Marcerized pulp of 10 to 50 wt.% obtained by performing cold alkali treatment on beatable natural cellulose fiber excellent in alkali resistance such as broadleaf tree wood pulp is used. After this is beaten to a range where a beating degree is 500 ml to 0 ml in CSF(Canda standard opening hydrature), vinylon fiber (0.5 d×2 mm) and polyvinyl alcohol fiber are added and mixed by 90 to 50 wt.%, and are formed as a raw material. This raw material is applied to a paper machine, and separator paper which has a thickness of 100μm and has basis weight of 32.5 g/cm<3> and has a small hole diameter and whose fiber is made dense and which holds airtightness high, can be obtained. Therefore, an internal short circuit by contact of a bipolar active material is prevented, and a thickness is thinned, and battery capacity can be increased. |
