| 摘要 |
<p>The present invention provides a glass substrate having high glass transition temperature and small compaction (C) in a heat treatment at a low temperature (150 to 300°C). The present invention relates to a glass substrate including, in mass percent based on the oxides, from 68 to 81% of SiO 2 , from 0.2 to 18% of Al 2 O 3 , from 0 to 3% of B 2 O 3 , from 0.2 to 11% of MgO, from 0 to 3% of CaO, from 0 to 3% of SrO, from 0 to 3% of BaO, from 0 to 1% of ZrO 2 , from 1 to 18% of Na 2 O, from 0 to 15% of K 2 O, and from 0 to 2% of Li 2 O, wherein Al 2 O 3 +K 2 O is from 7 to 27%, Na 2 O+K 2 O is from 11.5 to 22%, MgO+CaO+SrO+BaO is from 0.2 to 14%,
MgO+0.357Al 2 O 3 -0.239K 2 O-5.58 is from -3.0 to 1.5,
Na 2 O+0.272Al 2 O 3 +0.876K 2 O-16.77 is from -2.5 to 2.5, a glass transition temperature is 500°C or higher, and an average thermal expansion coefficient at from 50 to 350°C is 100×10 -7 /°C or less.</p> |
