| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical glass which has a low glass transition temperature (Tg), does not contain substances detrimental to the environment and is excellent in homogeneity. SOLUTION: The optical glass does not contain Pb and As compounds and contains P<SB>2</SB>O<SB>5</SB>, SnO and R<SB>2</SB>O (R is not less than one kind selected from among the group consisting of Li, Na, K and Cs) as indispensable components. The optical glass contains SnO, TiO<SB>2</SB>, Nb<SB>2</SB>O<SB>5</SB>and WO<SB>3</SB>in a way that 1-60% of SnO and not more than 3% of the aggregate of TiO<SB>2</SB>, Nb<SB>2</SB>O<SB>5</SB>and WO<SB>3</SB>in terms of oxide-based mol% are included has a shortest wavelength of a light having a light transmittance exceeding 80% (λ80) of not more than 450 nm. The optical glass as described in Claim 1 or 2 contains 30-80% of P<SB>2</SB>O<SB>5</SB>and 1-35% of R<SB>2</SB>O (R is not less than one kind selected from among the group consisting of Li, Na, K and Cs) in terms of oxide-based mol%. COPYRIGHT: (C)2009,JPO&INPIT
|
