| 摘要 |
PURPOSE:To obtain a vertical magnetizing base film whose thermal resistance is high, moisture uptake is less than that of polyester, the coefficient of linear expansion is small and maximum surface roughness becomes less than 500Angstrom , by making molecular orientation and heat setting of poly-p-phenylenesulfide. CONSTITUTION:Rear tension of more than 80kg/cm<2> is given to a poly-p-phenylenesulfide film at least, and the film is rolled into 1.5-4 times by pressure rolls which makes a pair and is falling within a temperature range of more than 60 deg.C and less than 140 deg.C through linear pressure of more than 100kg/cm at least and fixed thermally at a temperature of more than 220 deg.C and less than the fusion point. In addition to the above, thinning of the film can be done, as the film whose molecule has oriented extermely high is obtained when the film is orientated in the direction of a film width and orientation is applied to a longitudinal direction of the film also as well as rolling of the film. In this case, the film is orientated 1.5-4 times in the direction of the film width and 1.1-2 times in a longitudianl direction respectively at a temperature of more than 80 deg.C and less than 130 deg.C. |
