Patent attributes
The invention provides a heat-shrinkable film that has (1) a glass transition temperature (Tg) of 90-140° C.; (2) shrinkage of 12% or less in a main shrinkage direction when treated in glycerin at 80° C. for 10 seconds; (3) shrinkage of 12% or less in a direction orthogonal to the main shrinkage direction when treated in glycerin at 140° C. for 10 seconds; (4) shrinkage of 30%-80% in the main shrinkage direction when treated in glycerin at 140° C. for 10 seconds; (5) a tensile elongation at break of 10% or more both in the main shrinkage direction and the orthogonal direction after aging of 672 hours at 50° C. and 70% RH; and (6) a difference of 5% or less between shrinkage at 140° C. in the main shrinkage direction after aging of 672 hours at 50° C. and 70% RH, and shrinkage at 140° C. in the main shrinkage direction before the aging.
