| 摘要 |
PROBLEM TO BE SOLVED: To provide an oriented film which comprises a biodegradable polymer, such as polylactic acid, has a weight reduced to the level of that of a polyolefin film, and has practical film physical properties, because polyesters used as raw materials for biodegradable films generally have large specific gravities and do not always reduce loads on environments due to larger weights than those of the films of polyolefins of conventional raw materials. SOLUTION: This biodegradable polymer-based foamed oriented film is obtained by melt-kneading the biodegradable polymer, such as polylactic acid, with a foaming agent in an extruder, extruding the melt-kneaded product from a die, cooling to form the biodegradable polymer foamed sheet, such as polylactic acid sheet, having a porosity of 2 to 45% and a space diameter of 0.01 to 1 μm, and then orienting the sheet to form the oriented film. When the oriented film is compounded with titanium dioxide, the oriented film further largely develops white color and can be used for the use of synthetic paper. COPYRIGHT: (C)2007,JPO&INPIT |
