| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To improve the pin hole-resistance of an outer covering material by solving such problems with a vacuum insulating material that pin holes are produced by the insertion of a core material into the outer covering material or the bending of a corrugated part of the vacuum insulating material and, for the vacuum insulating material mounted in a refrigerator, the problem appears remarkably since the size thereof is increased. <P>SOLUTION: The pin holes in the vacuum insulating material are caused mainly by the anisotropy of a film used for the heat-fused layer of the outer covering material. To reduce the production of the pin holes, a straight chain low density polyethylene is used for the heat-fused layer of the outer covering material as an anisotropy-free material. Also, a high gas-barrier performance in addition to the pin-hole resistance can be assured by setting the specific gravity of the straight chain low density polyethylene to 0.935 or higher and blending a high density polyethylene with the low density polyethylene. <P>COPYRIGHT: (C)2004,JPO</p> |
