To obtain a film excellent in heat shrinkage characteristics and adhesion to a container and capable of being released by an alkaline aqueous solution by imparting a stretched film of a polymer composed mainly of a particle-containing polylactic acid with a heat shrinkage factor of a specific value or more and a maximum heat shrinkage stress of a specific value or less in hot air of a specific temperature.
There is provided a heat-shrinkable film having a thickness of 1-300 μm comprising a polymer composed mainly of a polylactic acid containing 0.01-1 wt.% of particles having an average particle size of 0.001-10 μm. The film has a heat shrinkage factor in at least one direction of at least 20% and a maximum heat shrinkage stress of 5.0 MPa or less in hot air of 120°C and at least 50% of the film can be dissolved in an alkaline aqueous solution having a pH of at least 7. As the lactic acid polymer can be mentioned D-lactic acid polymers, L-lactic acid polymers, D-lactic acid/L-lactic acid copolymers, D-lactic acid/hydroxy carboxylic acid copolymers, and the like. As the particles are employed inorganic particles such as kaolin or the like, organic particles such as calcium oxalate or the like, crosslinked polymer particles such as styrene-divinylbenzene copolymers or the like, inner particles formed in a polymer, or the like.
| JP2002019045 | CONDUCTIVE LAMINATE PACKAGING MATERIAL |
| JP2684913 | MANUFACTURE OF LAMINATED PACKAGING MATERIAL |
MATSUSHIMA HIROKO
KIMURA MASAHIRO
