| 摘要 |
PROBLEM TO BE SOLVED: To provide: a base material for a lithium ion secondary battery separator, excellent in workability during manufacture, and also excellent in strength, uniformity, and handleability during a post-process; and a lithium ion secondary battery separator manufactured using the base material for a lithium ion secondary battery separator.SOLUTION: A base material for a lithium ion secondary battery separator contains polyethylene terephthalate fibers. An average fiber diameter of the polyethylene terephthalate fibers is 9.0 μm or less, a relative X-ray diffraction intensity derived from the polyethylene terephthalate fibers is 300 cps/(g/m) or more, and a coefficient of variation of the relative X-ray diffraction intensity is 12.0% or less. In a method for producing a base material for a lithium ion secondary battery separator, a base paper containing polyethylene terephthalate fibers is subjected to thermal calendering treatment by means of a thermal calendering device including a resin roll and a heated metal roll. A lithium ion secondary battery separator is obtained by forming a coating layer containing inorganic particles on the base material for a lithium ion secondary battery separator of the present invention. |
