| abstract |
PURPOSE:To manufacture a film having excellent properties at favorable yield, by making specific particulates inactive to polyester exist within the film. CONSTITUTION:As for the titled film, substance containing substantially 0.01-1wt% anatase-type titanium dioxide compound whose mean particle diameter is 0.1-0.6mu, Ra is 0.005-0.015mu and Rmax is less than 0.18mu as surface roughness, F-5 value in a longitudinal direction is more than 14kg/mm<2> and a relation between a heat shrinkage factor and the F-5 satisfies an expression 1 is used. With this construction, a base film for high recording density which is superior in easily lubricating properties and winding characteristics, moreover, generates few flaw at a manufacturing process, and is superior in electromagnetic characteristics, thermal dimensional stability and skew characteristics can be obtained at favorable yield when the film is processed into a magnetic tape. |