摘要 |
The invention relates to multilayer heat insulators wherein gas-impermeable layers each made of a metal foil of one member selected from the group consisting of aluminum, nickel and stainless steel and gas-containing layers each made of at least one member selected from the group consisting of glass fiber, asbestos fiber, mineral fiber, ceramic fiber, carbon fiber, silica powder, alumina powder and zirconia powder in the form of wool, paper or mat are laminated alternately so that the same layers do not contact each other. The thickness of the gas-impermeable layer is 10 to 20 mu m, the thickness of the gas-containing layer is 0.3 to 1.8 mm and its porosity is 0.98 to 0.95 to make the thermal conductivity of this laminated multilayer heat insulator about 0.02 kcal/mh DEG C. (200 DEG C.) so that the behavior of the contained gas may be as small as possible, the thermal conduction may be prevented and the heat insulating performance may be improved.
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