| abstract |
In a vacuum heat insulation box having a double wall structure, deformation, cracks and distortion of the box are suppressed, and reliability and heat insulation performance are improved. A vacuum heat insulating box 1 has a box made of at least an outer box 3 and an inner box 5 made of a gas barrier material, and a box and a heat insulating space 7 between the outer box 3 and the inner box 5 A vacuum heat insulating box 1 having a vacuum heat insulating structure by providing a contacting core material 6 and depressurizing the heat insulating space 7, wherein the volume change rate before and after the pressure reduction of the core material 6 due to the deformation of the box body due to atmospheric compression by the reduced pressure Is within 50%. Thereby, even if the box is compressed by atmospheric compression by decompression, since the volume change of the core material 6 is small, the deformation of the box can be suppressed, and the reliability such as the suppression of deformation and cracks can be improved. [Selection] Figure 3 |