JP2020015662A5 - - Google Patents

Claims (13)

Optical glass made of borosilicate glass
Weight loss _{D NaOH} per unit area when immersed for 15 hours in a NaOH aqueous solution is less than ^{0.25mg / (cm 2 · 15h)} , and the Abbe number νd and partial dispersion ratio Pg, and the F below (4 )formula:
Pg, F> -0.0004νd + 0.5718 ... (4)
Optical glass that meets. Nb ⁵⁺ The optical glass according to claim 1, which contains 1.0 cation% or more. Al ³⁺ And Nb ⁵⁺ The optical glass according to claim 1 or 2, which contains 10 cation% or more in total. O ^2- Content is 10 to 85 anion% and F ⁻ The optical glass according to any one of claims 1 to 3, wherein the content of the optical glass is 15 to 90 anion%. Mg ²⁺ , Ca ²⁺ , Sr ²⁺ And Ba ²⁺ Contains at least one alkaline earth metal component selected from the group consisting of Mg ²⁺ , Ca ²⁺ , Sr ²⁺ And Ba ²⁺ The optical glass according to any one of claims 1 to 4, wherein the total content of the optical glass is 20 cation% or more. P ⁵⁺ And Nb ⁵⁺ O for the total content of ^2- Molar ratio of content (O) ^2- / (P ⁵⁺ + Nb ⁵⁺ )) Is 3.0 or more, the optical glass according to any one of claims 1 to 5. P ⁵⁺ The content of is 5 to 40 cation% and Al. ³⁺ The optical glass according to any one of claims 1 to 6, wherein the content of the optical glass is 5 to 40 cation%. La ³⁺ , Gd ³⁺ , Y ³⁺ , Lu ³⁺ And Yb ³⁺ Contains at least one rare earth component selected from the group consisting of Al ³⁺ La for the content of ³⁺ , Gd ³⁺ , Y ³⁺ , Lu ³⁺ And Yb ³⁺ Mole ratio of total content of ((La) ³⁺ + Gd ³⁺ + Y ³⁺ ＋ Lu ³⁺ + Yb ³⁺ ) / Al ³⁺ The optical glass according to any one of claims 1 to 7, wherein) is 0.3 or less. The content of the alkali metal component is 1 cation% or more, and Li ^＋ The optical glass according to any one of claims 1 to 8, wherein the content of the optical glass is 20 cation% or less. In the glass composition expressed in atomic%, Al ³⁺ O for the content of ^2- Content ratio of (O ^2- / Al ³⁺ ) Is less than 10, the optical glass according to any one of claims 1 to 9. The optical glass according to any one of claims 1 to 10, wherein the abbe number νd is 45 or more. The following (1) to (4):
(1) Internal transmittance of 96.5% or more at a wavelength of 400 nm to 700 nm and a thickness of 10 mm.
(2) D _A Is less than 0.35%,
(3) D _STPP Is 0.40 mg / (cm ² ・ Less than h)
(4) D ₀ Is 5.0 × 10 ^-3 mg / (cm ² ・ Less than h)
The optical glass according to any one of claims 1 to 11, which satisfies at least one of the above. The optical element made of the optical glass according to any one of claims 1 to 12.