| 摘要 |
PURPOSE:To manufacture a bi-axially oriented polypropylene film having a good releasability, by reducing the face orientation of the film by either shrinking its area in a heat-setting after a bi-axial orientation or heat-treating it at the degree causing a surface whitening, or doing both jointly. CONSTITUTION:By either doing a shrinkage of 15-30% in an area ratio in a heat-setting after applying a thermosetting silicone resin after a longitudinal orientation and before a lateral stretching and finishing the lateral orientation or heat-treating it until causing a surface whitening, or doing both jointly a releasable bi-axially oriented polypropylene film is manufactured. |
