| 摘要 |
PURPOSE:To obtain the titled film whose appearance is good when it is subjected to shrink working and that is suitable for labels, by stretching a sheet of a styrene/butadiene block copolymer or the like at specified temperatures first in one direction and then in a direction normal to the first-mentioned direction at specified rates respectively. CONSTITUTION:After a sheet made of a styrene/butadiene block copolymer (preferably one having a styrene content of 75%) or a mixture consisting of 100pts.wt. styrene/butadiene block copolymer and 5-60pts.wt. polystyrene is stretched in one direction at a temperature 2-15 deg.C higher than its Vicat softening point at a rate of 1.2-1.8 times, it is stretched at a rate of 2.5 times in a direction normal to the first-mentioned direction, that is, generally in a circumferential direction of a cylindrical body into which the film will be formed when it is used as labels of bottles, so that the intended film can be obtained. EFFECT:The film can be prevented from secular cracking. |
