| 摘要 |
PROBLEM TO BE SOLVED: To provide a new glass material capable of manufacturing a glass product having excellent chemical durability and also having high precision by press molding method. SOLUTION: The glass for press molding is the glass containing 38-45 wt.% SiO<SB>2</SB>, 18-27 wt.% B<SB>2</SB>O<SB>3</SB>, 16-25 wt.% Al<SB>2</SB>O<SB>3</SB>, 2-12 wt.% ZnO,≤3 wt.% MgO,≤3 wt.% CaO,≤3 wt.% BaO, 13-18 wt.% Li<SB>2</SB>O,≤3 wt.% K<SB>2</SB>O and≤2 wt.% Na<SB>2</SB>O and having a glass yield temperature of≤520°C and having water resistance of≥2 grade by a measuring method of chemical durability of an optical glass of Japan Optical Glass Association Industrial Standards. COPYRIGHT: (C)2005,JPO&NCIPI
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