| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a vacuum heat insulating material with a solid component whose heat conduction is kept lower while suppressing the rupture of glass fibers in a core material due to the atmospheric pressure applied during vacuum package. <P>SOLUTION: The vacuum heat insulating material comprises the core material 3 formed of the glass fibers 1 and covered with an outer shell whose inner pressure is reduced. The glass fibers 1 have greater tensile rupture strength but larger rate, and so the core material 3 has greater tensile rupture strength. Since the glass fibers 1 have greater tensile rupture strength, no rupture of the glass fibers 1 is caused even when the core material 3 is compressed with the atmospheric pressure, peripheral spaces are held and the peripheral fibers 1 hardly contact each other. An increase in the heat conduction of the solid component is suppressed due to the contact of a rupture portion as a free end with the periphery. Thus, the vacuum heat insulating material is provided with the solid component whose heat conduction is kept lower. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
