JP2019019050A5

JP2019019050A5 -

Info

Publication number: JP2019019050A5
Application number: JP2018125896A
Authority: JP
Filing date: 2018-07-02
Publication date: 2019-03-22
Anticipated expiration: 2038-07-02

Claims

₁ to 45% by mass of B ₂ O ₃ and 10 to 60% by mass of La ₂ O ₃ ,
Comprising at least one oxide selected from the group consisting of TiO ₂ , Nb ₂ O ₅ , WO ₃ and Bi ₂ O ₃ ;
Optical glass whose value of (beta) OH shown to following formula (2) is 0.1-2.0 mm < ^-1 >.
βOH = − [ln (B / A)] / t (2)
[In the formula (2), t represents the thickness (mm) of the glass used for measuring the external transmittance, and A represents the external transmission at a wavelength of 2500 nm when light is incident on the glass in parallel with the thickness direction. B represents the external transmittance (%) at a wavelength of 2900 nm when light is incident on the glass in parallel to the thickness direction. In is a natural logarithm. ]

Containing SiO ₂ 0.1 to 25 wt%, the optical glass according to claim 1.

The SiO ₂ 0.5 to 15 _wt%, the B 2 _{O 3} 1 to 30 wt%, the _La 2 _{O 3} containing 20 to 60 wt%, the optical glass according to claim 1.

The optical glass according to claim 1, wherein the content of B ₂ O ₃ is larger than the content of SiO ₂ in terms of mass%.

The mass ratio [TiO ₂ / (B ₂ O ₃ + La ₂ O ₃ )] of the content of TiO ₂ to the total content of B ₂ O ₃ and La ₂ O ₃ is 0.030 or more. The optical glass according to any one of the above.

Abbe number νd is 20 to 45,
Optical glass in any one of Claims 1-5 whose refractive index nd is 1.75-2.50.

P _２2 O _５5 The optical glass in any one of Claims 1-6 whose content of is less than 7 mass%.

Nb _２2 O _５5 And TiO _２2 The optical glass in any one of Claims 1-7 whose total content of is 13 mass% or more.

Nb _２2 O _５5 And TiO _２2 The optical glass in any one of Claims 1-8 whose total content of is 40 mass% or less.

Nb _２2 O _５5 TiO _２2 , WO _３3 And Bi _２2 O _３3 The optical glass in any one of Claims 1-9 whose total content of is 40 mass% or less.

Nb _２2 O _５5 TiO _２2 , WO _３3 And Bi _２2 O _３3 The optical glass in any one of Claims 1-10 whose total content of is 1.0 mass% or more.

B _２2 O _３3 , La _２2 O _３3 , SiO _２2 , P _２2 O _５5 , Al _２2 O _３3 , ZnO, BaO, MgO, CaO, SrO, Gd _２2 O _３3 , Y _２2 O _３3 , Yb _２2 O _３3 , ZrO _２2 TiO _２2 , Nb _２2 O _５5 , WO _３3 , Bi _２2 O _３3 , Ta _２2 O _５5 , Li _２2 O, Na _２2 O, K _２2 O, Cs _２2 O, Sc _２2 O _３3 , HfO _２2 , Lu _２2 O _３3 And GeO _２2 The optical glass according to claim 1, wherein the total content of is more than 95% by mass.

  B _２2 O _３3 1 to 45 mass%, La _２2 O _３3 10-60 mass%, TiO _２2 More than 0% by mass, ZnO more than 0% by mass,
  Nb _２2 O _５5 TiO _２2 , WO _３3 And Bi _２2 O _３3 TiO with respect to the total content of _２2 The mass ratio of the content of [TiO _２2 / (Nb _２2 O _５5 + TiO _２2 + WO _３3 + Bi _２2 O _３3 )] Is 0.4 or more,
  The value of βOH shown in the following formula (2) is 0.1 to 2.0 mm. ^−１-1 Is optical glass.
  βOH = − [ln (B / A)] / t (2)
[In the formula (2), t represents the thickness (mm) of the glass used for measuring the external transmittance, and A represents the external transmission at a wavelength of 2500 nm when light is incident on the glass in parallel with the thickness direction. B represents the external transmittance (%) at a wavelength of 2900 nm when light is incident on the glass in parallel to the thickness direction. In is a natural logarithm. ]

The optical glass according to claim 1, wherein the content of platinum Pt is less than 10 ppm by mass.

The optical glass according to any one of claims 1 to 14, having a volume of 100 ml or more and a refractive index distribution of 0.00050 or less.

An optical element formed of the optical glass according to any one of claims 1 to 15.