| 摘要 |
PROBLEM TO BE SOLVED: To provide a base material through which a coating liquid is difficult to exudate to a back surface when applying the coating liquid containing an inorganic pigment in an unwoven fabric base material used for a lithium ion secondary battery separator.SOLUTION: The unwoven fabric base material for a lithium ion secondary battery separator is mainly composed of polyethylene terephthalate fiber, wherein the thickness is 30 μm or less, the density defined by basis weight/thickness is 0.55 g/cmor less, and the tensile strength is 800 N/m or over. |
