| 摘要 |
PROBLEM TO BE SOLVED: To provide a separator for a nonaqueous battery having both of internal short circuit prevention and heat resistance. SOLUTION: This separator for the nonaqueous secondary battery is a nonwoven fabric made of synthetic resin fibers having a mean diameter of 20μm or less, and formation (σ) obtained from variations of brightness obtained by a white light transmission method and the distribution of the variations of the brightness is 3.0 or less. The formation (σ) is measured in such a way that intensity of light from a light source is automatically adjusted so that the amount of average transmitted light is made constant, and by image analysis technique using a CCD camera, variations of brightness at a measuring point of 245, 760 pixels to a measuring area of 64 mm×64 mm are caught, then the results are distinguished in gray level 256 steps, a histogram is prepared by plotting, and the variations of brightness (Ti) and the distribution (Hi) of the variations of the brightness are used for calculation. COPYRIGHT: (C)2003,JPO |
