| 摘要 |
PROBLEM TO BE SOLVED: To provide optical glass which has characteristics of high refractive index and low dispersion, and better moldability. SOLUTION: The optical glass comprises, by weight: 1% or more and 5% or less of SiO<SB>2</SB>; 15% or more and 24% or less of B<SB>2</SB>O<SB>3</SB>; 0.1% or more and 3% or less of Al<SB>2</SB>O<SB>3</SB>; 1% or more and 14% or less of ZnO; 35% or more and 45% or less of La<SB>2</SB>O<SB>3</SB>; 5% or more and 10% or less of Y<SB>2</SB>O<SB>3</SB>; 5% or more and 13% or less of Ta<SB>2</SB>O<SB>3</SB>; and 0.5% or more and 3% or less of Li<SB>2</SB>O. Thereby, the deformation temperature and glass transition temperature are lowered while the high refractive index and the low dispersion are secured. Therein, the inclusion of Al<SB>2</SB>O<SB>3</SB>contributes to stabilization of the structure and hardly causes defective appearance such as fogging upon molding. COPYRIGHT: (C)2011,JPO&INPIT
|
