US Patent 7611761 Vacuum heat insulating material and refrigerating apparatus including the same

Vacuum heat insulating material having core material consisting of inorganic fibers and exterior covering material for storing the core material. The inorganic fibers include silicon oxide as a main component. The surface of the inorganic fibers has Si—OH/Si—O ratio equal to or higher than 0.1 and equal to or lower than 20. The vacuum heat insulating material has intersecting points at which the fibers are adhered to one another by an intermolecular interaction due to Si—OH groups.