| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide excellent in thermal insualtion property and maintain the thermal insulation property for a long time by vacuum-exhausting a hollow part containing a core material which is covered with a layered product having polyacrylonitrite resin and gas barrier resin composition composed of resin and inorganic layer compound. SOLUTION: A hollow part containing a core material covered with a layered product having a polyacrylonitrile resin and at least one layer of gas barrier resin composition layer composed of resin and inorganic layer compound, respectively, is vacuum-exhausted to manufacture a vacuum thermal insulation material. As the polycrylonitrile resin used as this time, for example, acrylonitrile- methyl acrylate-butadiee copolymer can be included. Moreover, the inorganic layer compound is formed in such a way that its aspect ratio is 50 or more ad 5000 or less, in particular, 200 or more and 3000 or less, and for example, graphite can be included. Moreover, oxygen permeability of the gas barrier resin component layer at a temperature of 23 deg.C and relative humidity of 50% is 0.1 cc/m<2> .day.atm or less.</p> |
