| 摘要 |
PURPOSE:To make the titled tape resistant to variations in the tension due to a sudden start and a sudden stop by providing a magnetic layer on one surface of a biaxially oriented polyethylene-2,6-naphthalene dicarboxylate having specified F-5 value in the longitudinal direction, refractive index in the thickness direction, intrinsic viscosity, and air leakage index. CONSTITUTION:The magnetic layer is provided on the surface of a biaxially oriented polyethylene-2,6-naphthalene dicarboxylate having >=20kg/mm<2> F-5 value (stress manifested in 5% elongation), >=1.490 refractive index Nz in the thickness direction, >=0.50 intrinsic viscosity, and <=1,000sec air leakage index to obtain the magnetic recording tape. When the F-5 value in the longitudinal direction is less than the value, strain remains when instantaneous high tension is exerted, the film can not be thinned, and eventually the recording density per unit volume can not be enhanced. When the refractive index Nz in the thickness direction and the intrinsic viscosity are beyond the limits, the end face of the slit tape becomes a so-called high edge, the appearance of the roll when the tape is rolled up on a reel is worsened, and the collapse of the roll can be caused. |
