| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce the cutting frequency of glass fibers for a vacuum heat insulating material, and reduce mixing probability of a shot. <P>SOLUTION: A glass fiber constituting a core material 2 is composed of a glass composition constituted such that SiO<SB POS="POST">2</SB>of 50 to 70%, Al<SB POS="POST">2</SB>O<SB POS="POST">3</SB>of 0 to 7%, Na<SB POS="POST">2</SB>O and K<SB POS="POST">2</SB>O of 8 to 20%, MgO of 0 to 6%, CaO of 2 to 15%, and other compositions of 3% or less by weight, and the total wt.% of the respective compositions is 100%, and the surface tension of the melt is ≤300 mN/m. Further, the innermost layer of an external encapsulating material 4 is a resin-made film with thickness of 15 μm to 50 μm. Thereby, the cutting frequency during glass fiberization is reduced, and mixing probability of a shot can be significantly reduced. <P>COPYRIGHT: (C)2013,JPO&INPIT |
