| 摘要 |
PURPOSE:To obtain the captioned film free from lateral creases, by performing longitudinal stretching at a specified multiplication rate different from that in the lateral direction to maintain a specified shrinkage relaxing stress when a block copolymer of styrene and butadiene is stretched biaxially. CONSTITUTION:A shrinkable film of biaxially-stretched styrene resin which is a biaxially-stretched film having as base resin a block copolymer of styrene and butadiene whose styrene content is 65-90wt%, or a polyblend of said block copolymer and polystyrene, and wherein an orientation relaxing stress measured in conformity with ASTM-D-1504 of this film is 0.5-4kg/cm<2> in the longitudinal direction of this film and 4-15kg/cm<2> in the lateral direction thereof. By the difference of the multiplication rate of stretching in the longitudinal direction from that in the lateral direction, a specified shrink relaxing stress is maintained in the longitudinal direction so that the generation of lateral creases is prevented. |
