| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical glass that has optical constants of a refractive index (nd) of 1.55-less than 1.67 and an Abbe number (νd) of 30-45; does not contain environmental pollutants such as PbO and components made from expensive raw materials such as Ta<SB>2</SB>O<SB>5</SB>and Nb<SB>2</SB>O<SB>5</SB>; has less environmental pollution; and can be produced at a low cost. SOLUTION: This optical glass comprises, by mass%, 40-60% of SiO<SB>2</SB>, 1-less than 5% of B<SB>2</SB>O<SB>3</SB>, 0-3% of Al<SB>2</SB>O<SB>3</SB>, 15.5-19% of TiO<SB>2</SB>, 0-1% or ZrO<SB>2</SB>, 0-5% of WO<SB>3</SB>, 0-5% of ZnO, 0-4% of CaO, 0-10% of SrO, 10.5-20% of BaO, 0-9% of Na<SB>2</SB>O, 6-20% of K<SB>2</SB>O, wherein Na<SB>2</SB>O+K<SB>2</SB>O is 10.5-20%, and 0-1% of a defoaming agent, wherein it has the optical constants in the range of a refractive index (nd) of 1.55-less than 1.67 and an Abbe number (νd) of 30-45. COPYRIGHT: (C)2004,JPO
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