| 摘要 |
PROBLEM TO BE SOLVED: To stably keep a vacuum condition by sealing the peripheral edge of a resin laminate film prepd. by laminating an aluminum foil with a resin film covering an open-cell urethane foam whose edges are bevelled and making the inside vacuum. SOLUTION: A vacuum heat-insulation material is constituted of an open-cell urethane foam 8 and a resin laminate film prepd. by laminating a resin A, an aluminum foil B and a resin C covering this material into a bag-like shape. A vacuum heat-insulation material is obtd. by covering the open-cell urethane foam 8 with a two sheets of resin laminate films and performing heat fusion under vacuum and sealing them hermetically. As each edge of the open-cell urethane foam 8 covered with the resin laminate films is bevelled, there exists hardly possibility of generating folding and wrinkles on the part of the aluminum foil B of the resin laminate film being brought into contact with the edge part of the open-cell urethane foam 8. Therefore, a possibility of generating cracks on the part of the aluminum foil B and breakage of vacuum therefrom is remarkably decreased and it becomes possible to keep the degree of vacuum for a long time. |
