| 摘要 |
PURPOSE:To obtain the titled polyester excellent in anti-slip property by using the film base satisfying a specific relation formula between the refractive index in the thickness direction of the film and the intrinsic viscosity thereof. CONSTITUTION:Being based on a biaxially oriented film wherein the refraction index [nz] in the thickness direction and the intrinsic viscosity [eta] of polymer are regulated in the ranges of FormulasI-III, a magnetic body (such as magnetic coating material obtained by dispersing metallic powder such as gamma-Fe2O3 etc. in a binder composed of a copolymer such as polyvinyl chloride, polyvinyl acetate, etc., or a mixture thereof or other resin) is vaporized in polyester (homopolymer having polyethylene terephthalate as the main component is preferable) to obtain the desired film. USE:Audio tape, video tape, computer tape, etc. |
