| 摘要 |
PROBLEM TO BE SOLVED: To produce a film for a capacitor having excellent slidability and operability and a good mechanical characteristic, by using a polymer which is polymerized by using a specified range of metallic catalyst as a catalyst at the time of polymerization of a polymer, and to which specified quantities of two types of spherical silica fine particles of different average grain sizes are mixed. SOLUTION: A film for capacitor is produced, the film being made of polyethylene-2,6-naphthalate which contains spherical silica fine particles having a grain size ratio (long diameter/short diameter) of 1.0 to 1.2 and an average grain size of 0.5 to 5μm, at 0.1 to 2 wt.%, and spherical silica fine particles having a grain size ratio (long diameter/short diameter) of 1.0 to 1.2 and an average grain size of 0.01 to 1μm, at 0.1 to 2 wt.%, with a base factor of 3 to 23% and with a density of protrusions with a height of not smaller than 1.5μm on the film surface equal to or less than 50/cm<2> . In this case, a Mn compound and a Sb compound as polymerization catalysts for naphthalate, and a P compound as a thermal stabilizer are contained in quantities satisfying formulas I, II and III, and the content of an alkaline metal is not more than 10 ppm.
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