MULTILAYERED POLYSTYRENIC HEAT-SHRINKABLE FILM

摘要

PROBLEM TO BE SOLVED: To reduce a natural shrinkage factor and to enhance strength, surface characteristics, stiffness and low temp. shrinkability. SOLUTION: A multilayered polystyrenic heat-shrinkable film has at least three-layered structure wherein both outer layers comprise a mixture consisting of 92-99.5 wt.% of a styrene/butadiene/styrene block copolymer with a butadiene unit content of at least 15 wt.% and 0.5-8 wt.% of a styrene/butyl acrylate and an intermediate layer comprises a mixture consisting of 10-50 wt.% of a styrene/butadiene/styrene block copolymer with a butadiene unit content of at least 15 wt.% and 50-90 wt.% of a styrene/butyl acrylate copolymer. The ratio of the intermediate layer to the whole is 50-90 wt.% and the total butadiene unit content to the whole is 5-15 wt.%.