Heat-shrinkable film, molded product and heat-shrinkable label employing the film, and container employing the molded product or having the label fitted thereon

摘要

A heat-shrinkable film having a layer made of a mixed resin containing a polylactic acid resin and a polyolefin resin as the main components, wherein the mass ratio of the polylactic acid resin and the polyolefin resin is 95/5 to 50/50, the polylactic acid resin is a copolymer of D-lactic acid and L-lactic acid or a mixed resin of the copolymer, the D/L ratio of D-lactic acid and L-lactic acid is 3/97 to 15/85 or 85/15 to 97/3, the storage elastic modulus of the polyolefin resin or the soft acrylic resin at 20° C. is ≦100 MPa as measured at an oscillation frequency of 10 Hz and a strain of 0.1%, the film is stretched in at least one direction, and the heat shrinkage ratio of the film in the main shrinking direction is ≧20% as measured after the film is immersed in 80° C. water for 10 seconds.

主权项

1. A heat-shrinkable film consisting of a layer or comprising at least one layer,
wherein the layer is made of a mixed resin containing a polylactic acid resin and a soft acrylic resin as the main components, wherein mass ratio of the polylactic acid resin and the soft acrylic resin is 95/5 to 50/50 by mass, the polylactic acid resin being a copolymer of D-lactic acid and L-lactic acid or a mixed resin of the copolymer, the soft acrylic resin comprises: at least one polymer block (A) composed of an acrylic acid ester (a); and at least one polymer block (B) composed of a (meth) acrylic acid ester (b-1) whose chemical structure is different from that of the acrylic acid ester (a), the storage elastic modulus (E′) of the soft acrylic resin at 20 degree C. being 100 MPa or less as measured at an oscillation frequency of 10 Hz and a strain of 0.1%, the film being stretched in at least one direction, the heat shrinkage ratio of the film in the main shrinking direction being 20% or more as measured after the film is immersed in hot water of 80 degree C. for 10 seconds, and the heat shrinkage ratio of the film in the direction perpendicular to the main shrinking direction being 10% or less after the film is immersed in hot water of 80 degree C. for 10 seconds.