Patent ID: 7638181

Claim:
A vacuum heat insulator comprising: a core formed of a laminated body where glass fibers are laminated in a thickness direction of the vacuum heat insulator, wherein the glass fibers contain an alkali content of at least 0.8% and at most 20% in weight, and the average diameter of the glass fibers is 3.5 μM; and an enveloping member covering the core and having gas barrier property, wherein the core is heat-pressed at a temperature of 480° C. for 5 minutes, such temperature being lower than the strain point of the glass fibers and insufficient to cross-link the glass fibers through necks formed between the glass fibers, and molded so that the laminated body has a density of 100 kg/m 3 to 400 kg/m 3 , thereby a shape of the core during heat-press is kept by an anchor effect due to entanglement of parts of the glass fibers instead of binding of the glass fibers and an effect in which the glass fibers are drawn by heat deformation of the glass fibers, and the glass fibers are not cross-linked through necks formed between the glass fibers.