| 摘要 |
<p>PROBLEM TO BE SOLVED: To retain a heat-insulating capacity for a long period, by limitting the total gas volume permeating from the end face of a plastic film laminated in the inside of metallic foil of an external bag within a specified volume. SOLUTION: Heat fused plastic films are laminated in the inside of a gas- barrier layer including a metallic foil to form an external bag made of a vacuum heat-insulation material. Most of gas permeates from the heat fused layer into the external bag. The permeating volume is proportional to the gas permeability of the film. And hence, A heat fused plastic film of which total permeation gas volume is 0.08μL/day or smaller per 1 lit. of the inner volume of the vacuum heat-insulation material at 25 deg.C, 50% RH atmosphere, is used, in the gas permeation from the end face of the plastic film laminated in the inside of a metallic foil of the external bag of the vacuum heat-insulation material. In this way, even if a getter is not used against gas permeation from the outside, the heat- insulating capacity can be retained for a long period.</p> |
