PURPOSE: To provide a vacuum heat insulation material without deformation at the time of vacuum discharge, and without deterioration of vacuum even after being left for a long period of time by laminating plural sheets of manufactured paper comprising inorganic fibers, and binding the inorganic fibers to each other at each intersectional point by component eluted from the fibers.
CONSTITUTION: An average fiber diameter of inorganic fibers is set to 2μm or less, and glass fibers are favorable because they can be obtained easily. Heat diffusion material may be mixed in paper in screening, and it is desirably titanium oxide with relating of heat diffusion effect, handling easiness, etc. In the case of manufacturing a vacuum heat insulation material, the paper sheets obtained by oxidation screening of the inorganic fibers are laminated on each other in plurality, an obtained material is immersed in an atmosphere of PH5 or less, that is acid solution of PH5 or less, for example, it is pressed to a desired thickness, and it is heated and dried. Deformation such as dents, etc., is thus prevented at the time of vacuum discharge, and vacuum deterioration will not occur for a long period of time because it contains no organic or inorganic binder, thereby a vacuum heat insulation material of small vacuum heat conductivity, favorable handling easiness, and excellent heat insulation performance can be provided.
MIYASHITA SEI
MASUDA RYUJI
