Optical glass and optical elements

Abstract

To provide optical glass and the like that achieves target parameters such as reducing costs, stabilizing the glass, and maintaining the glass's melting properties. [Solution] In the glass composition of the optical glass, the SiO2 content is 10-50%, the ZrO2 content is 3-30%, the Nb2O5 content is 0-7.5%, the TiO2 content is 5-50%, the CaO content is greater than 0% and 50% or less, the B2O3 content is greater than 0% and 50% or less, the La2O3 content is 0-25%, and the Li2O content is 0- The present invention provides optical glass with a concentration of 6%, a Y2O3 content of 0-30%, and the following ratios: (ZrO2+TiO2) / (SiO2+B2O3)=0.40-1.12, (Li2O+Na2O+K2O) / CaO=0-0.38, (La2O3+Gd2O3+Y2O3) / (ZrO2+TiO2)=0-0.97, and SiO2 / (SiO2+B2O3)=0.41-1.00.

Description

[Technical Field]

[0001] The present invention relates to an optical glass that reduces cost while being stable and achieving target parameters, and to an optical element containing the optical glass. [Background technology]

[0002] In the composition of optical glass, niobium oxide (Nb2O5) can improve the refractive index, lower the Abbe number, and stabilize the glass to some extent. However, if its content is too high, the stability of the glass decreases, its meltability deteriorates, and the unit price of Nb2O5 raw materials is too high, making it unfavorable from a cost perspective. Therefore, it is desirable to reduce the content of Nb2O5 in the glass composition through compositional adjustment. Patent Document 1 discloses optical glass containing Nb2O5, but the Nb2O5 content is relatively high. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 62-132741 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] Therefore, the present invention was developed in view of the above-mentioned problems, and its objective is to provide optical glass and optical elements including said optical glass that reduce costs while simultaneously achieving target parameters such as glass stabilization and maintenance of glass meltability. [Means for solving the problem]

[0005] The gist of this invention is, for example, as follows: (1) In the glass composition of optical glass expressed in mass%, when the total mass of the optical glass is taken as 100% by mass, The SiO2 content is 10-50% by mass. The ZrO2 content is 3-30% by mass. The Nb2O5 content is 0-7.5% by mass. The TiO2 content is 5-50% by mass. The CaO content is greater than 0% and less than or equal to 50% by mass. The B2O3 content is greater than 0% and less than or equal to 50% by mass. The La2O3 content is 0-25% by mass. The Li2O content is 0-6% by mass. The Y2O3 content is 0-30% by mass. The mass ratio of the total content of ZrO2 and TiO2 to the total content of SiO2 and B2O3 (ZrO2 + TiO2) / (SiO2 + B2O3) is 0.4 to 1.12. The mass ratio of the total content of Li2O, Na2O, and K2O to the CaO content (Li2O+Na2O+K2O) / CaO is between 0 and 0.38. The mass ratio of the total content of La2O3, Gd2O3, and Y2O3 to the total content of ZrO2 and TiO2 is (La2O3+Gd2O3+Y2O3) / (ZrO2+TiO2) between 0 and 0.97. Optical glass in which the mass ratio of SiO2 content to the total content of SiO2 and B2O3, SiO2 / (SiO2+B2O3), is 0.41 to 1.00. (2) The optical glass described in (1) that satisfies at least one of the following conditions, The BaO content is 0-30% by mass. The SrO content is 0-20% by mass. The MgO content is 0-10% by mass. The Na2O content is 0-10% by mass. The K2O content is 0-10% by mass. The Ta2O5 content is 0-10% by mass. The WO3 content is 0-10% by mass. The Gd2O3 content is 0-10% by mass. The ZnO content is 0-20% by mass.

[0006] (3) The optical glass according to (1) or (2), satisfying at least one of the following: The mass ratio (La2O3 + Gd2O3 + Y2O3) / B2O3 of the total content of La2O3, Gd2O3 and Y2O3 to the B2O3 content is 0.65 to 2.30, The mass ratio (Li2O + Na2O + K2O) / SiO2 of the total content of Li2O, Na2O and K2O to the SiO2 content is 0 to 0.30, The mass ratio CaO / (ZrO2 + TiO2) of the CaO content to the total content of ZrO2 and TiO2 is 0 to 1.20, The mass ratio (Li2O + Na2O + K2O) / (ZrO2 + TiO2) of the total content of Li2O, Na2O and K2O to the total content of ZrO2 and TiO2 is 0 to 0.26, The mass ratio (BaO + SrO) / (CaO + MgO) of the total content of BaO and SrO to the total content of CaO and MgO is 0 to 2.95, The mass ratio (Nb2O5 + Ta2O5 + WO3) / (La2O3 + Gd2O3 + Y2O3) of the total content of Nb2O5, Ta2O5 and WO3 to the total content of La2O3, Gd2O3 and Y2O3 is 0 to 0.44.

[0007] (4) The optical glass according to any one of (1) to (3), satisfying at least one of the following: The refractive index nd is 1.7620 to 1.8260, The Abbe number vd is 28.00 to 40.00, The specific gravity is 3.00 to 4.20, λ 80 is 390 to 550 nm, λ 70 is 365 to 460 nm, λ5 is 340 to 370 nm.

[0008] (5) The optical glass according to any one of (1) to (4), satisfying at least one of the following: The SiO2 content is 11 to 45 mass%, The ZrO2 content is 4-25% by mass. The Nb2O5 content is 0-7% by mass. The TiO2 content is 8-45% by mass. The CaO content is 3-45% by mass. The B2O3 content is 0.5 to 40% by mass. The La2O3 content is 0-24% by mass. The Li2O content is 0-5% by mass. The Y2O3 content is 0-28% by mass. The BaO content is 0-28% by mass. The SrO content is 0-18% by mass. The MgO content is 0-9% by mass. The Na2O content is 0-9% by mass. The K2O content is 0-8% by mass. The Ta2O5 content is 0-8% by mass. The WO3 content is 0-8% by mass. The Gd2O3 content is 0-8% by mass. The ZnO content is 0-18% by mass. The mass ratio of the total content of ZrO2 and TiO2 to the total content of SiO2 and B2O3 (ZrO2 + TiO2) / (SiO2 + B2O3) is 0.50 to 1.10. The mass ratio of the total content of Li2O, Na2O, and K2O to the CaO content (Li2O+Na2O+K2O) / CaO is between 0 and 0.35. The mass ratio of the total content of La2O3, Gd2O3, and Y2O3 to the total content of ZrO2 and TiO2 (La2O3+Gd2O3+Y2O3) / (ZrO2+TiO2) is between 0.20 and 0.96. The mass ratio of SiO2 content to the total content of SiO2 and B2O3, SiO2 / (SiO2+B2O3), is between 0.42 and 0.97. The mass ratio of the total content of La2O3, Gd2O3, and Y2O3 to the B2O3 content (La2O3+Gd2O3+Y2O3) / B2O3 is between 0.70 and 2.10. The mass ratio of the total content of Li2O, Na2O, and K2O to the SiO2 content (Li2O+Na2O+K2O) / SiO2 is between 0.02 and 0.26. The mass ratio of CaO content to the total content of ZrO2 and TiO2, CaO / (ZrO2+TiO2), is between 0.10 and 1.15. The mass ratio of the total content of Li2O, Na2O, and K2O to the total content of ZrO2 and TiO2 (Li2O+Na2O+K2O) / (ZrO2+TiO2) is between 0.01 and 0.23. The mass ratio of the total content of BaO and SrO to the total content of CaO and MgO (BaO+SrO) / (CaO+MgO) is between 0 and 2.50. The mass ratio of the total content of Nb2O5, Ta2O5, and WO3 to the total content of La2O3, Gd2O3, and Y2O3 is (Nb2O5+Ta2O5+WO3) / (La2O3+Gd2O3+Y2O3) between 0 and 0.40. The refractive index nd is 1.7700 to 1.8210. The Abbe number vd is between 29.00 and 39.00. The specific gravity is 3.05 to 4.10. λ 80 The range is 392-545nm, λ 70 The range is 367-455nm, λ5 is between 341 and 369 nm.

[0009] (6) Optical glass described in any one of items (1) to (4) below, which satisfies at least one of the following conditions The SiO2 content is 13-40% by mass. The ZrO2 content is 5-20% by mass. The Nb2O5 content is 0-6% by mass. The TiO2 content is 11-40% by mass. The CaO content is 6-40% by mass. The B2O3 content is 1-30% by mass. The La2O3 content is 0-23% by mass. The Li2O content is 0-4% by mass. The Y2O3 content is 0-26% by mass. The BaO content is 0-26% by mass. The SrO content is 0-16% by mass. The MgO content is 0-8% by mass. The Na2O content is 0-7% by mass. The K2O content is 0-4% by mass. The Ta2O5 content is 0-6% by mass. The WO3 content is 0-6% by mass. The Gd2O3 content is 0-6% by mass. The ZnO content is 0-16% by mass. The mass ratio of the total content of ZrO2 and TiO2 to the total content of SiO2 and B2O3 (ZrO2 + TiO2) / (SiO2 + B2O3) is 0.60 to 1.00. The mass ratio of the total content of Li2O, Na2O, and K2O to the CaO content (Li2O+Na2O+K2O) / CaO is between 0.02 and 0.30. The mass ratio of the total content of La2O3, Gd2O3, and Y2O3 to the total content of ZrO2 and TiO2 (La2O3+Gd2O3+Y2O3) / (ZrO2+TiO2) is between 0.30 and 0.92. The mass ratio of SiO2 content to the total content of SiO2 and B2O3, SiO2 / (SiO2+B2O3), is between 0.44 and 0.94. The mass ratio of the total content of La2O3, Gd2O3, and Y2O3 to the B2O3 content (La2O3+Gd2O3+Y2O3) / B2O3 is between 0.75 and 2.00. The mass ratio of the total content of Li2O, Na2O, and K2O to the SiO2 content (Li2O+Na2O+K2O) / SiO2 is between 0.04 and 0.22. The mass ratio of CaO content to the total content of ZrO2 and TiO2, CaO / (ZrO2+TiO2), is between 0.20 and 1.05. The mass ratio of the total content of Li2O, Na2O, and K2O to the total content of ZrO2 and TiO2 (Li2O+Na2O+K2O) / (ZrO2+TiO2) is between 0.02 and 0.17. The mass ratio of the total content of BaO and SrO to the total content of CaO and MgO (BaO+SrO) / (CaO+MgO) is between 0 and 2.05. The mass ratio of the total content of Nb2O5, Ta2O5, and WO3 to the total content of La2O3, Gd2O3, and Y2O3 is (Nb2O5+Ta2O5+WO3) / (La2O3+Gdx2O3+Y2O3) between 0 and 0.36. The refractive index nd is 1.7800 to 1.8160. The Abbe number vd is between 30.00 and 37.00. The specific gravity is 3.10 to 4.00. λ 80 The wavelength range is 396-540nm. λ 70 The wavelength is 369-450nm, λ5 is between 343 and 367 nm.

[0010] (7) Optical glass described in any one of items (1) to (4) below, which satisfies at least one of the following conditions The SiO2 content is 15-36% by mass. The ZrO2 content is 6-15% by mass. The Nb2O5 content is 0-5% by mass. The TiO2 content is 14-30% by mass. The CaO content is 9-35% by mass. The B2O3 content is 2-20% by mass. The La2O3 content is 0-22% by mass. The Li2O content is 0-3% by mass. The Y2O3 content is 0-24% by mass. The BaO content is 0-24% by mass. The MgO content is 0-7% by mass. The Na2O content is 0-5% by mass. The K2O content is 0-2% by mass. The Ta2O5 content is 0-2% by mass. The WO3 content is 0-2% by mass. The Gd2O3 content is 0-2% by mass. The ZnO content is 0-14% by mass. The mass ratio of the total content of La2O3, Gd2O3, and Y2O3 to the total content of ZrO2 and TiO2 (La2O3+Gd2O3+Y2O3) / (ZrO2+TiO2) is between 0.40 and 0.87. The mass ratio of the total content of La2O3, Gd2O3, and Y2O3 to the B2O3 content (La2O3+Gd2O3+Y2O3) / B2O3 is 0.85 to 1.90. The mass ratio of the total content of Li2O, Na2O, and K2O to the SiO2 content (Li2O+Na2O+K2O) / SiO2 is 0.08 to 0.18. The mass ratio of CaO content to the total content of ZrO2 and TiO2, CaO / (ZrO2+TiO2), is 0.40 to 0.90. The mass ratio of the total content of Li2O, Na2O, and K2O to the total content of ZrO2 and TiO2 (Li2O+Na2O+K2O) / (ZrO2+TiO2) is between 0.04 and 0.11. The mass ratio of the total content of BaO and SrO to the total content of CaO and MgO (BaO+SrO) / (CaO+MgO) is between 0 and 1.60. The mass ratio of the total content of Nb2O5, Ta2O5, and WO3 to the total content of La2O3, Gd2O3, and Y2O3 is (Nb2O5+Ta2O5+WO3) / (La2O3+Gd2O3+Y2O3) between 0 and 0.32. The Abbe number vd is between 30.00 and 36.00. The specific gravity is 3.15 to 3.80. λ 80 The wavelength range is 400-530nm. λ 70 The range is 371-445nm, λ5 is between 345 and 365 nm.

[0011] (8) Optical glass described in any one of items (1) to (4) below, which satisfies at least one of the following conditions The K2O content is 0% by mass. The Ta2O5 content is 0% by mass. The WO3 content is 0% by mass. The Gd2O3 content is 0% by mass. The mass ratio of the total content of La2O3, Gd2O3, and Y2O3 to the total content of ZrO2 and TiO2 (La2O3+Gd2O3+Y2O3) / (ZrO2+TiO2) is between 0.50 and 0.82. (9) An optical element comprising optical glass as described in any one of items (1) to (8). [Effects of the Invention]

[0012] According to the present invention, it is possible to provide optical glass that reduces costs while simultaneously achieving target parameters such as glass stabilization and maintenance of glass meltability, as well as optical elements containing said optical glass. [Modes for carrying out the invention]

[0013] Embodiments of the present invention will be described below. In the present invention and this specification, unless otherwise specified, the glass composition of optical glass is expressed on an oxide basis. Here, "glass composition on an oxide basis" means that it is based on the glass composition obtained by calculating the substances that exist as oxides in the optical glass after all of the glass raw materials have decomposed during melting, and each glass component is expressed as SiO2, TiO2, etc., according to convention. Unless otherwise specified, the content and total content of glass components are on a mass basis, and "%" refers to "mass%". The content of glass components can be quantified by known methods, such as inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS). In this specification and the present invention, a component content of 0% means that the component is substantially absent, and that the presence of unavoidable impurities is permitted at unavoidable impurity levels (usually less than 1% by mass overall, more specifically less than 1% by mass or 0.5% by mass for Al2O3, less than 0.15% by mass for HfO2, and less than 10 ppm for Fe-containing compounds and Cr-containing compounds). In this specification, unless otherwise specified, the refractive index refers to the refractive index nd at the helium d-line (wavelength 587.56 nm). The glass composition of the optical glass of the present invention will be described in more detail below.

[0014] (Glass composition) In the optical glass of the present invention, the SiO2 content may be 10 to 50%. The lower limit of the SiO2 content is preferably 11%, and more preferably 12%, 13%, 14%, and 15%, in that order. The upper limit of the SiO2 content is preferably 48%, and more preferably 46%, 45%, 44%, 43%, 42%, 41%, 40%, 39%, 38%, 37%, 36%, and 35%, in that order. The upper limit of the SiO2 content may also be 30%, 25%, and 20%. SiO2 is a component of the glass's network structure, and the addition of SiO2 can improve the stability of the glass and lower its specific gravity. As long as the SiO2 content is not too high, the glass melting temperature will not become too high. In the optical glass of the present invention, the B2O3 content may be greater than 0% and less than or equal to 50%. The lower limit of the B2O3 content is preferably 0.01%, and more preferably 0.1%, 0.2%, 0.5%, 1%, 1.5%, 2%, and 2.5% in the following order. The lower limit of the B2O3 content may also be 5%, 10%, and 15%. The upper limit of the B2O3 content is preferably 45%, and more preferably 40%, 38%, 36%, 35%, 34%, 32%, 30%, 29%, 28%, 27%, 26%, 25%, 24%, 23%, 22%, 21%, 20%, and 19% in the following order. B2O3 is a glass network forming body with a low refractive index and can lower the devitrification temperature and specific gravity of the glass. As long as the B2O3 content is not too high, it will not reduce the viscosity of the glass.

[0015] In the optical glass of the present invention, the ZrO2 content may be 3 to 30%. The lower limit of the ZrO2 content is preferably 3.5%, and more preferably 3.8%, 4.0%, 4.2%, 4.5%, 4.8%, 5%, 5.2%, 5.5%, 5.8%, and 6%, in the following order. The lower limit of the ZrO2 content may also be 7% or 8%. The upper limit of the ZrO2 content is preferably 28%, and more preferably 26%, 25%, 24%, 23%, 22%, 21%, 20%, 19%, 18%, 17%, 16%, 15%, 14%, and 11%, in the following order. ZrO2 is a component that can improve the refractive index and Abbe number of the glass, and also improve the devitrification resistance of the glass. If the ZrO2 content is not too high, the devitrification temperature of the glass will not rise too much, and the stability of the glass can be maintained. In the optical glass of the present invention, the Nb2O5 content may be 0 to 7.5%. The Nb2O5 content is preferably 7% or less, and more preferably 6.5% or less, 6% or less, 5.5% or less, 5% or less, 4.5% or less, 4% or less, 3.5% or less, 3% or less, 2.5% or less, 2% or less, 1.5% or less, 1% or less, 0.5% or less, 0.2% or less, and most preferably 0%. The Nb2O5 component can improve the refractive index and lower the Abbe number, and can also stabilize the glass to a certain extent. If the Nb2O5 content is not too high, the stability and meltability of the glass will not deteriorate, and the cost of the glass material will not increase.

[0016] In the optical glass of the present invention, the TiO2 content may be 5 to 50%. The lower limit of the TiO2 content is preferably 6%, and more preferably 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, and 15%, in the following order. The upper limit of the TiO2 content is preferably 45%, and more preferably 40%, 38%, 36%, 35%, 32%, 30%, 29%, 28%, 27%, 26%, 25%, and 20%, in the following order. TiO2 is a glass intermediate oxide and can improve the refractive index and chemical stability of the glass. If the TiO2 content is not too high, discoloration of the glass can be avoided and transmittance can be maintained. In the optical glass of the present invention, the CaO content may be greater than 0% and less than or equal to 50%. The lower limit of the CaO content is preferably 0.01%, and more preferably 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, and 20%, in the following order. The upper limit of the CaO content is preferably 48%, and more preferably 45%, 42%, 40%, 39%, 38%, 37%, 36%, 35%, 34%, 33%, 32%, and 31%, in the following order. The upper limit of the CaO content may also be 30%, 25%, and 20%. CaO is an outer oxide of the glass network, and it plays a certain melting aiding role and can lower the specific gravity of the glass. If the CaO content is not too high, it will not lead to a decrease in the refractive index of the glass.

[0017] In the optical glass of the present invention, the La2O3 content may be 0 to 25%. The lower limit of the La2O3 content may preferably be 2%, 4%, 6%, or 8%. The upper limit of the La2O3 content is preferably 24.5%, and more preferably 24%, 23.5%, 23%, 22.5%, 22%, 21.5%, and 21%, in the following order. The upper limit of the La2O3 content may also be 19%, 16%, or 13%. La2O3 plays a role in improving the refractive index and Abbe number in glass. If the La2O3 content is not too high, the specific gravity of the glass will not increase, and the stability of the glass can be maintained. In the optical glass of the present invention, the Li2O content is 0 to 6%. The Li2O content is preferably 5.5% or less, and more preferably 5% or less, 4.5% or less, 4% or less, 3.5% or less, 3% or less, and 2.5% or less, in the following order. Li2O is an outer oxide of the glass network and plays a certain role in melting assistance in the glass. If the Li2O content is not too high, the tendency for crystallization of the glass will not increase.

[0018] In the optical glass of the present invention, the Y2O3 content can be 0 to 30%. The lower limit of the Y2O3 content is preferably 1%, and more preferably 2%, 3%, 4%, and 5%, in that order. The upper limit of the Y2O3 content is preferably 29%, and more preferably 28% or less, 27% or less, 26% or less, 25% or less, 24% or less, and 23% or less, in that order. The upper limit of the Y2O3 content may also be 20%, 18%, 15%, 13%, and 10%. Y2O3 plays a role in improving the refractive index and Abbe number in glass. If the Y2O3 content is not too high, the specific gravity of the glass will not increase, and the stability of the glass can be maintained. In the optical glass of the present invention, the BaO content may be 0 to 30%. The BaO content is preferably 29% or less, and more preferably 28% or less, 27% or less, 26% or less, 25% or less, 24% or less, and 23% or less, in the following order. The BaO content may also be 20% or less, 15% or less, 10% or less, 5% or less, and 0%. BaO is an outer oxide of the glass network and can improve the meltability and devitrification resistance of the glass. If the BaO content is not too high, the specific gravity of the glass will not increase.

[0019] In the optical glass of the present invention, the SrO content is 0 to 20%. The SrO content is preferably 19% or less, more preferably 18% or less, 17% or less, 16% or less, and 15% or less, in the following order, and the SrO content may be 10% or less, 5% or less, and 0%. SrO is an outer oxide of the glass network, and if included in small amounts, it can improve the meltability of the glass. If the SrO content is not too high, it will not increase the tendency of the glass to crystallize, nor will it increase the specific gravity of the glass. In the optical glass of the present invention, the MgO content may be 0 to 10%. The MgO content is preferably 9.5% or less, and more preferably 9% or less, 8.5% or less, 8% or less, 7.5% or less, and 7% or less, in the following order. The MgO content may also be 6% or less, 4% or less, 2% or less, and 0%. MgO is an outer oxide of the glass network, and its presence in small amounts can improve the melting properties of the glass. If the MgO content is not too high, the tendency of the glass to crystallize will not increase. In the optical glass of the present invention, the Na2O content may be 0 to 10%. The Na2O content is preferably 9% or less, and more preferably 8% or less, 7% or less, 6% or less, 5% or less, 4% or less, and 3% or less, in the following order. The Na2O content may also be 2% or less or 0%. Na2O is an outer oxide of the glass network and can improve the meltability of the glass. If the Na2O content is not too high, it will not reduce the refractive index and viscosity of the glass.

[0020] In the optical glass of the present invention, the K2O content may be 0 to 10%. The K2O content is preferably 9% or less, more preferably 8% or less, 7% or less, 6% or less, 5% or less, 4% or less, 3% or less, 2% or less, 1% or less, and most preferably 0%. K2O is an outer oxide of the glass network and can improve the meltability of the glass. If the K2O content is not too high, it will not reduce the refractive index and viscosity of the glass. In the optical glass of the present invention, the Ta2O5 content may be 0 to 10%. The Ta2O5 content is preferably 9% or less, more preferably 8% or less, 7% or less, 6% or less, 5% or less, 4% or less, 3% or less, 2% or less, 1% or less, and most preferably 0%. Ta2O5 is a component that improves the refractive index of the glass and lowers the Abbe number. The melting temperature of Ta2O5 is relatively high. If the Ta2O5 content is not too high, the stability of the glass can be maintained without degrading the melting properties of the glass.

[0021] In the optical glass of the present invention, the WO3 content may be 0 to 10%. The WO3 content is preferably 9% or less, more preferably 8% or less, 7% or less, 6% or less, 5% or less, 4% or less, 3% or less, 2% or less, 1% or less, and most preferably 0%. WO3 is a component that improves the refractive index of the glass and lowers the Abbe number, and if included in small amounts, it can reduce the tendency of glass crystallization. If the WO3 content is not too high, the transmittance can be maintained without increasing the coloration of the glass. In the optical glass of the present invention, the Gd2O3 content can be 0 to 10%. The Gd2O3 content is preferably 9% or less, more preferably 8% or less, 7% or less, 6% or less, 5% or less, 4% or less, 3% or less, 2% or less, 1% or less, and most preferably 0%. Gd2O3 is a component that improves the refractive index and Abbe number of the glass. If the Gd2O3 content is not too high, it will not increase the specific gravity of the glass, nor will it increase the tendency for glass crystallization.

[0022] In the optical glass of the present invention, the ZnO content may be 0 to 20%. The ZnO content is preferably 19% or less, and more preferably 18% or less, 17% or less, 16% or less, 15% or less, and 14% or less, in the following order. The ZnO content may also be 10% or less, 5% or less, and 0%. ZnO is an outer oxide of the glass network, and can improve the chemical stability of the glass, effectively lower the glass transition temperature Tg, and reduce the viscosity of the glass. If the ZnO content is not too high, the stability of the glass can be maintained and the tendency for crystallization will not increase. In the optical glass of the present invention, the mass ratio (ZrO2+TiO2) / (SiO2+B2O3) of the total content of ZrO2 and TiO2 to the total content of SiO2 and B2O3 can be 0.40 to 1.12. The lower limit of this mass ratio (ZrO2+TiO2) / (SiO2+B2O3) is preferably 0.45, and more preferably 0.50, 0.55, 0.60, 0.65, and 0.70 in the following order. The upper limit of this mass ratio (ZrO2+TiO2) / (SiO2+B2O3) is preferably 1.10, and more preferably 1.05, 1.00, 0.95, and 0.90 in the following order. ZrO2 and TiO2 can improve the weather resistance of glass as glass intermediate oxides, but they require relatively high melting temperatures. By setting the mass ratio (ZrO2+TiO2) / (SiO2+B2O3) within the above range, an optical glass with relatively good meltability and a certain degree of weather resistance can be obtained.

[0023] In the optical glass of the present invention, the mass ratio of the total content of Li2O, Na2O, and K2O to the CaO content (Li2O+Na2O+K2O) / CaO can be 0 to 0.38. The lower limit of this mass ratio (Li2O+Na2O+K2O) / CaO is preferably 0.01, and more preferably 0.02, 0.03, 0.04, 0.05, and 0.06 in the following order. The upper limit of this mass ratio is preferably 0.35, and more preferably 0.32, 0.30, 0.29, 0.28, 0.27, 0.26, 0.25, 0.24, 0.20, 0.18, and 0.15 in the following order. Li2O, Na2O, K2O, and CaO all exhibit a certain melting-assisting effect. If the content of Li2O, Na2O, and K2O is not too high, the stability of the glass can be maintained without destroying the cross-linked oxygen bonds. By setting the mass ratio (Li2O+Na2O+K2O) / CaO within the above range, an optical glass that is relatively stable and has relatively good meltability can be obtained.

[0024] In the optical glass of the present invention, the mass ratio (La2O3+Gd2O3+Y2O3) / (ZrO2+TiO2) of the total content of La2O3, Gd2O3, and Y2O3 to the total content of ZrO2 and TiO2 can be between 0 and 0.97. The lower limit of this mass ratio (La2O3+Gd2O3+Y2O3) / (ZrO2+TiO2) is preferably 0.1, and more preferably 0.20, 0.30, 0.40, and 0.50 in the following order. The upper limit of this mass ratio (La2O3+Gd2O3+Y2O3) / (ZrO2+TiO2) is preferably 0.96, and more preferably 0.95, 0.92, 0.87, 0.82, and 0.77 in the following order. La2O3, Gd2O3, Y2O3, ZrO2, and TiO2 can all improve the refractive index of glass, but they have different effects on the Abbe number. By setting the mass ratio (La2O3+Gd2O3+Y2O3) / (ZrO2+TiO2) within the above range, the target Abbe number can be obtained.

[0025] In the optical glass of the present invention, the mass ratio of the SiO2 content to the total content of SiO2 and B2O3, SiO2 / (SiO2+B2O3), can be 0.41 to 1.00. The lower limit of the mass ratio SiO2 / (SiO2+B2O3) is preferably 0.42, and more preferably 0.43, 0.44, 0.45, and 0.47 in the following order. The upper limit of the mass ratio SiO2 / (SiO2+B2O3) is preferably 0.99, and more preferably 0.98, 0.97, 0.96, 0.95, 0.94, and 0.93 in the following order. The upper limit of the mass ratio may also be 0.90, 0.85, 0.80, 0.75, and 0.70. Both SiO2 and B2O3 are structural components of glass, and B2O3 reduces the viscosity of the glass. By keeping the mass ratio SiO2 / (SiO2+B2O3) within the above range, it is possible to guarantee that the molded glass will have a certain viscosity.

[0026] In the optical glass of the present invention, the mass ratio of the total content of Li2O, Na2O, and K2O to the SiO2 content (Li2O+Na2O+K2O) / SiO2 can be 0 to 0.30. The lower limit of the mass ratio (Li2O+Na2O+K2O) / SiO2 is preferably 0.01, and more preferably 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, and 0.08 in the following order. The upper limit of the mass ratio (Li2O+Na2O+K2O) / SiO2 is preferably 0.29, and more preferably 0.28, 0.27, 0.26, 0.25, 0.24, 0.23, 0.22, 0.21, 0.20, 0.19, 0.18, and 0.14 in the following order. Alkali metal oxides such as Li2O, Na2O, and K2O have a melting aiding effect. If the content is not too high, it will not break the cross-linked oxygen bonds, nor will it increase the tendency for glass crystallization. By setting the mass ratio (Li2O+Na2O+K2O) / SiO2 within the above range, the desired stability and melting properties can be obtained. In the optical glass of the present invention, the mass ratio of CaO content to the total content of ZrO2 and TiO2, CaO / (ZrO2+TiO2), can be 0 to 1.20. The lower limit of the mass ratio CaO / (ZrO2+TiO2) is preferably 0.05, and more preferably 0.10, 0.15, 0.20, 0.25, 0.30, 0.40, and 0.50, in the following order. The upper limit of the mass ratio CaO / (ZrO2+TiO2) is preferably 1.19, and more preferably 1.15, 1.10, 1.05, 1.00, 0.95, 0.90, 0.85, and 0.80, in the following order. CaO is a low refractive index component, and ZrO2 and TiO2 are high refractive index components, and by setting the mass ratio CaO / (ZrO2+TiO2) within the above range, the target refractive index can be obtained.

[0027] In the optical glass of the present invention, the mass ratio (La2O3+Gd2O3+Y2O3) / B2O3 of the total content of La2O3, Gd2O3, and Y2O3 to the B2O3 content can be 0.65 to 2.30. The lower limit of this mass ratio (La2O3+Gd2O3+Y2O3) / B2O3 is preferably 0.66, and more preferably 0.67, 0.68, 0.69, 0.70, 0.71, 0.72, 0.73, 0.74, 0.75, 0.80, 0.85, and 0.90, in the following order. The upper limit of the mass ratio (La2O3+Gd2O3+Y2O3) / B2O3 is preferably 2.29, and more preferably 2.28, 2.27, 2.26, and 2.25 in the following order, and may also be 2.20, 2.10, 2.00, 1.90, 1.80, 1.70, 1.60, and 1.50. La2O3, Gd2O3, and Y2O3 are components with high refractive indices and are difficult to melt, while B2O3 is a component with a low refractive index and is easily melted. By setting the mass ratio (La2O3+Gd2O3+Y2O3) / B2O3 within the above range, an optical glass with relatively good meltability and target parameters can be obtained.

[0028] In the optical glass of the present invention, the mass ratio (Li2O+Na2O+K2O) / (ZrO2+TiO2) of the total content of Li2O, Na2O, and K2O to the total content of ZrO2 and TiO2 can be 0 to 0.26. The lower limit of the mass ratio (Li2O+Na2O+K2O) / (ZrO2+TiO2) is preferably 0.01, and more preferably 0.02, 0.03, and 0.04 in the following order. The upper limit of the mass ratio (Li2O+Na2O+K2O) / (ZrO2+TiO2) is preferably 0.25, and more preferably 0.24, 0.23, 0.22, 0.21, 0.20, 0.19, 0.18, 0.17, 0.14, and 0.11 in the following order. Alkali metal oxides such as Li2O, Na2O, and K2O have a melting aid effect and do not reduce glass strength unless present in large quantities. ZrO2 and TiO2 can improve glass strength as glass intermediate oxides, and by setting their mass ratio (Li2O+Na2O+K2O) / (ZrO2+TiO2) within the above range, optical glass with relatively good meltability and a certain strength can be obtained.

[0029] In the optical glass of the present invention, the mass ratio (BaO+SrO) / (CaO+MgO) of the total content of BaO and SrO to the total content of CaO and MgO can be 0 to 2.95. The upper limit of the mass ratio (BaO+SrO) / (CaO+MgO) is preferably 2.95, and more preferably 2.80, 2.70, 2.60, 2.50, 2.40, 2.30, 2.20, 2.05, 2.00, 1.90, 1.80, 1.70, 1.60, and 1.50 in the following order, and may also be 1.00, 0.50, and 0. Among the divalent alkali metals, BaO and SrO are high specific gravity components, and CaO and MgO are low specific gravity components, and by setting the mass ratio (BaO+SrO) / (CaO+MgO) within the above range, a target relatively low specific gravity can be obtained. In the optical glass of the present invention, the mass ratio (Nb2O5+Ta2O5+WO3) / (La2O3+Gd2O3+Y2O3) of the total content of Nb2O5, Ta2O5, and WO3 to the total content of La2O3, Gd2O3, and Y2O3 can be between 0 and 0.44. The upper limit of this mass ratio (Nb2O5+Ta2O5+WO3) / (La2O3+Gd2O3+Y2O3) is preferably 0.42, and more preferably 0.40, 0.38, 0.36, 0.34, 0.32, and 0.30 in the following order, and may also be 0.20, 0.10, and 0. Nb2O5, Ta2O5, and WO3 are low Abbe number components, while La2O3, Gd2O3, and Y2O3 are high Abbe number components. By setting the mass ratio (Nb2O5+Ta2O5+WO3) / (La2O3+Gd2O3+Y2O3) within the above range, the target Abbe number can be obtained.

[0030] (Glass properties) <refractive index nd> The refractive index nd of the optical glass of the present invention may be between 1.7620 and 1.8260. The lower limit of the refractive index nd is preferably 1.7660, and more preferably 1.7700, 1.7720, 1.7740, 1.7760, 1.7780, and 1.7800, in the following order. The upper limit of the refractive index nd is preferably 1.8240, and more preferably 1.8220, 1.8210, 1.8200, 1.8180, and 1.8160, in the following order. The refractive index nd can be set to a desired value by appropriately adjusting the content of each glass component. Alternatively, the refractive index nd can also be set to a desired value by appropriately adjusting the respective content ratios.

[0031] <Abbe number vd> The Abbe number vd is a value indicating the property related to chromatic dispersion, and is expressed as vd = (nd - 1) / (nF - nC) using the refractive indices nd, nF, and nC at the d-line, F-line, and C-line. In the optical glass of the present invention, the Abbe number vd is preferably 28.00 to 40.00. The lower limit of the Abbe number vd is preferably 28.50, and more preferably 29.00, 29.50, 30.00 in the following order. The upper limit of the Abbe number vd is preferably 39.50, and more preferably 39.00, 38.50, 38.00, 37.50, 37.00, 36.50, 36.00 in the following order. By appropriately adjusting the content of each glass component, the Abbe number vd can be set to a desired value. Also, for example, by appropriately adjusting the above-mentioned content ratios, the Abbe number vd can be set to a desired value.

[0032] <Specific gravity of glass> The specific gravity (g / cm 3 ) of the optical glass of the present invention can be 3.00 to 4.20. The lower limit of the specific gravity of the optical glass of the present invention is preferably 3.05, and more preferably 3.10, 3.15, 3.20 in the following order. The upper limit of the specific gravity is preferably 4.15, and more preferably 4.​​​​​​​​​​​​​​​​​Let λ5 be the wavelength at which the external transmittance is 5%. The optical glass of the present invention 80 It can be 390-550 nm. λ 80 The lower limit is preferably 392 nm, and more preferably 394 nm, 396 nm, 398 nm, and 400 nm, in the following order: λ 80 The upper limit is preferably 545nm, and more preferably 540nm, 535nm, and 530nm in the following order. The optical glass of the present invention 70 λ can be 365-460 nm. 70 The lower limit is preferably 366 nm, and more preferably 367 nm, 368 nm, 369 nm, 370 nm, and 371 nm, in the following order: λ 70 The upper limit is preferably 455nm, and more preferably 452nm, 450nm, 448nm, and 445nm in the following order. The λ5 of the optical glass of the present invention may be 340 to 370 nm. The lower limit of λ5 is preferably 341 nm, and more preferably 342 nm, 343 nm, 344 nm, and 345 nm in the following order. The upper limit of λ5 is preferably 369 nm, and more preferably 368 nm, 367 nm, 366 nm, and 365 nm in the following order. Furthermore, the λ of the optical glass of the present invention 80 , λ 70 And λ5 can be brought to a desired range by adjusting the content of each glass component and the respective content ratios.

[0034] (Manufacturing of optical glass) The glass of the present invention can be produced by blending glass raw materials to achieve the predetermined composition described above, and then using the blended glass raw materials according to known glass manufacturing methods. For example, several types of compounds can be blended and thoroughly mixed to form a batch raw material, and the batch raw material can be placed in a quartz crucible or a platinum crucible and subjected to rough melting. The molten material obtained from rough melting can be rapidly cooled and crushed to form cullet. Furthermore, the cullet can be placed in a platinum crucible, heated, and remelted to form molten glass, and after further clarification and homogenization, the molten glass can be shaped and slowly cooled to obtain optical glass. Known methods can be used for shaping and slow cooling of the molten glass. Furthermore, as long as the desired glass components can be introduced into the glass to achieve the desired content, the compounds used in the batch raw material formulation are not particularly limited, and examples of such compounds include oxides, carbonates, nitrates, hydroxides, and fluorides.

[0035] (Manufacturing of optical elements, etc.) When manufacturing optical elements using the optical glass of the present invention, known methods may be used. For example, in the manufacture of the optical glass described above, molten glass is poured into a mold and formed into a plate to produce a glass material made of the optical glass of the present invention. The obtained glass material is cut, ground, and polished as appropriate to produce fragments of a size and shape suitable for press molding. The fragments are heated and softened, and press molded (reheat press) is performed by known methods to produce an optical element blank that approximates the shape of the optical element. The optical element blank is annealed, and then ground and polished by known methods to produce an optical element. Depending on the intended use, the optical functional surface of the fabricated optical element may be coated with an anti-reflective coating, a total reflection coating, or the like. According to one embodiment of the present invention, an optical element formed from the above-mentioned optical glass can be provided. Examples of types of optical elements include lenses such as spherical lenses and aspherical lenses, prisms, and diffraction gratings. Examples of lens shapes include various shapes such as biconvex lenses, plano-convex lenses, biconcave lenses, plano-concave lenses, convex meniscus lenses, and concave meniscus lenses. The optical element can be manufactured by a method that includes a process of processing a glass molded body formed from the above-mentioned optical glass. Examples of processing include cutting, machining, rough grinding, finish grinding, and polishing. When performing such processing, using the above-mentioned glass can reduce breakage and stably provide high-quality optical elements. [Examples]

[0036] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to the embodiments shown in the examples. Glass samples with the glass compositions shown in Tables 1 to 13 were prepared in the following order, and each was evaluated.

[0037] [Manufacturing of optical glass] First, oxides, hydroxides, carbonates, and nitrates corresponding to the constituent components of glass were prepared as raw materials. These materials were weighed and blended so that the resulting optical glass composition matched the compositions shown in Tables 1 to 13, and the materials were thoroughly mixed. The resulting blended raw materials (batch raw materials) were placed in a platinum crucible and heated at 1350°C to 1400°C for 2 to 4 hours to form molten glass. The mixture was then stirred to homogenize it, clarified, and the molten glass was cast into a mold preheated to an appropriate temperature. The cast glass was heat-treated at an arbitrary temperature between Tg and 100°C below the glass transition temperature Tg for 30 minutes, and then allowed to cool to room temperature (25°C) in a furnace to obtain a glass sample.

[0038] [Confirmation of glass component composition] The content of each glass component in the obtained glass samples was measured by inductively coupled plasma atomic emission spectrometry (ICP-AES), and it was confirmed that the compositions matched those shown in Tables 1 to 13.

[0039] [Measurement of optical properties] The obtained glass samples were further subjected to annealing treatment at approximately 30 minutes to 2 hours near the glass transition temperature Tg, and then cooled in a furnace at a cooling rate of -30°C / hour to room temperature (25°C) to obtain annealed samples. The refractive index nd, Abbe number vd, specific gravity, and λ of the obtained annealed samples were determined. 80 , λ 70 The values ​​of λ5 and λ5 were measured, and the results are shown in Tables 1 to 13, respectively. (i) Refractive index nd and Abbe number vd For the above annealing samples, the refractive index nd was measured at the 12 wavelengths shown in Table A, according to the Japanese Industrial Standard (JIS) JIS B7071-1 Method for measuring the refractive index of optical glass - Part 1: Minimum deflection method. Next, the refractive indices of each radiation obtained by measurement were substituted into the shot dispersion formula specified in Appendix B of the Japanese Industrial Standard (JIS) JIS B7071-1 Method for Measuring the Refractive Index of Optical Glass - Part 1: Minimum Declination Method, and the constants of the shot dispersion formula were determined by the least squares method. Subsequently, the Abbe number vd was calculated using the shot dispersion formula with the specified constants. (ii) Specific gravity The specific gravity was measured using the Archimedes method. (iii)λ 80 , λ 70 λ5 The above annealing sample was processed to have a thickness of 10 mm and parallel, optically polished planes, and the spectral transmittance was measured in the wavelength range of 200 nm to 700 nm. The intensity of light rays incident perpendicularly to one of the optically polished planes was defined as intensity A, and the intensity of light rays emitted from the other plane was defined as intensity B, and the spectral transmittance B / A was calculated. The wavelength at which the spectral transmittance was 80% was defined as λ. 80 The wavelength at which the spectral transmittance is 70% is λ 70 The wavelength at which the spectral transmittance is 5% was defined as λ5. Note that the spectral transmittance includes the reflection loss of light rays from the surface of the test sample.

[0040] [Table 1] [Table 2] [Table 3] [Table 4] [Table 5] [Table 6] [Table 7] [Table 8] [Table 9] [Table 10] [Table 11] [Table 12] [Table 13] As described in Tables 1 to 13 above, the present invention can realize optical glass that achieves target parameters such as reducing costs, stabilizing the glass, and maintaining the melting properties of the glass.

[0041] Furthermore, all embodiments disclosed herein are illustrative and not restrictive. The scope of the present invention should be understood to be defined by the claims rather than the foregoing description and to encompass all variations equivalent to the claims in meaning and scope. For example, by performing the compositional adjustments described in the specification on the glass composition exemplified above, an optical glass according to one embodiment of the present invention can be produced. Furthermore, naturally, two or more items described as examples or preferred scopes in the specification can be arbitrarily combined.

Claims

1. In the glass composition of optical glass, when the total mass of the optical glass is taken as 100% by mass, SiO 2 The content is 10 to 50% by mass, ZrO 2 The content is 3 to 30% by mass, Nb 2 O 5 The content is 0 to 7.5% by mass. TiO 2 The content is 5 to 50% by mass. The CaO content is greater than 0% by mass and 50% by mass or less. B 2 O 3 The content is greater than 0% and less than or equal to 50% by mass. La 2 O 3 The content is 0 to 25% by mass, Li 2 The oxygen content is 0 to 6% by mass. Y 2 O 3 The content is 0 to 30% by mass, ZrO 2 and TiO 2 Total content of SiO 2 and B 2 O 3 The mass ratio of the total content (ZrO 2 +TiO 2 ) / (SiO 2 +B 2 O 3 ) is between 0.40 and 1.12, Li 2 O, Na 2 O and K 2 The mass ratio of the total O content to the CaO content (Li 2 O + Na 2 O+K 2 O) / CaO is 0 to 0.38, La 2 O 3 , Gd 2 O 3 and Y 2 O 3 Total content of ZrO 2 and TiO 2 Mass ratio of total content (La 2 O 3 +Gd 2 O 3 +Y 2 O 3 ) / (ZrO 2 +TiO 2 ) is between 0 and 0.97, SiO 2 SiO content 2 and B 2 O 3 Mass ratio of SiO to total content 2 / (SiO 2 +B 2 O 3 Optical glass in which the ratio is 0.41 to 1.

00.

2. The optical glass according to claim 1, which satisfies at least one of the following conditions. The BaO content is 0 to 30% by mass. The SrO content is 0 to 20% by mass. The MgO content is 0 to 10% by mass. Na 2 The oxygen content is 0 to 10% by mass. K 2 The oxygen content is 0 to 10% by mass. Ta 2 O 5 The content is 0 to 10% by mass, WO 3 The content is 0 to 10% by mass, Gd 2 O 3 The content is 0 to 10% by mass, The ZnO content is 0 to 20% by mass.

3. The optical glass according to claim 1, which satisfies at least one of the following conditions. La 2 O 3 , Gd 2 O 3 and Y 2 O 3 Total content of B 2 O 3 Mass ratio to content (La 2 O 3 +Gd 2 O 3 +Y 2 O 3 ) / B 2 O 3 The values ​​range from 0.65 to 2.

30. Li 2 O, Na 2 O and K 2 Total O content of SiO 2 Mass ratio to content (Li 2 O + Na 2 O+K 2 O) / SiO 2 The range is 0 to 0.

30. ZrO with CaO content 2 and TiO 2 Mass ratio of CaO / (ZrO) to total content 2 +TiO 2 ) is between 0 and 1.20, Li 2 O, Na 2 O and K 2 The total content of O in ZrO 2 and TiO 2 The mass ratio of (Li 2 O + Na 2 O + K 2 O) / (ZrO 2 + TiO 2 ) is 0 to 0.26, The mass ratio of the total content of BaO and SrO to the total content of CaO and MgO (BaO + SrO) / (CaO + MgO) is between 0 and 2.

95. Nb 2 O 5 Ta 2 O 5 and WO 3 The total content of La 2 O 3 , Gd 2 O 3 and Y 2 O 3 Mass ratio of total content (Nb 2 O 5 +Ta 2 O 5 +WO 3 ) / (La 2 O 3 +Gd 2 O 3 +Y 2 O 3 The value is between 0 and 0.

44.

4. The optical glass according to claim 1, which satisfies at least one of the following conditions. The refractive index nd is 1.7620 to 1.8260. The Abbe number vd is between 28.00 and 40.

00. The specific gravity is 3.00 to 4.

20. λ 80 The wavelength is 390-550 nm. λ 70 The wavelength is 365-460 nm. λ 5 The wavelength is 340-370 nm.

5. The optical glass according to claim 1, which satisfies at least one of the following conditions. SiO 2 The content is 11 to 45% by mass. ZrO 2 The content is 4 to 25% by mass. Nb 2 O 5 The content is 0 to 7% by mass, TiO 2 The content is 8 to 45% by mass. The CaO content is 3 to 45% by mass. B 2 O 3 The content is 0.5 to 40% by mass. La 2 O 3 The content is 0 to 24% by mass, Li 2 The oxygen content is 0 to 5% by mass. Y 2 O 3 The content is 0 to 28% by mass, The BaO content is 0 to 28% by mass. The SrO content is 0 to 18% by mass. The MgO content is 0-9% by mass. Na 2 The oxygen content is 0 to 9% by mass. K 2 The oxygen content is 0 to 8% by mass. Ta 2 O 5 The content is 0 to 8% by mass, WO 3 The content is 0 to 8% by mass, Gd 2 O 3 The content is 0 to 8% by mass, The ZnO content is 0 to 18% by mass. ZrO 2 and TiO 2 Total content of SiO 2 and B 2 O 3 The mass ratio of the total content (ZrO 2 +TiO 2 ) / (SiO 2 +B 2 O 3 ) is between 0.50 and 1.10, Li 2 O, Na 2 O and K 2 The mass ratio of the total O content to the CaO content (Li 2 O + Na 2 O+K 2 O) / CaO is 0 to 0.35, La 2 O 3 , Gd 2 O 3 and Y 2 O 3 Total content of ZrO 2 and TiO 2 Mass ratio of total content (La 2 O 3 +Gd 2 O 3 +Y 2 O 3 ) / (ZrO 2 +TiO 2 ) is between 0.20 and 0.96, SiO 2 SiO content 2 and B 2 O 3 Mass ratio of SiO to total content 2 / (SiO 2 +B 2 O 3 ) is between 0.42 and 0.97, La 2 O 3 , Gd 2 O 3 and Y 2 O 3 Total content of B 2 O 3 Mass ratio to content (La 2 O 3 +Gd 2 O 3 +Y 2 O 3 ) / B 2 O 3 The values ​​range from 0.70 to 2.

10. Li 2 O, Na 2 O and K 2 Total O content of SiO 2 Mass ratio to content (Li 2 O + Na 2 O+K 2 O) / SiO 2 The values ​​range from 0.02 to 0.

26. ZrO with CaO content 2 and TiO 2 Mass ratio of CaO / (ZrO) to total content 2 +TiO 2 ) is between 0.10 and 1.15, Li 2 O, Na 2 O and K 2 Total O content of ZrO 2 and TiO 2 Mass ratio of total content (Li 2 O + Na 2 O+K 2 O) / (ZrO) 2 +TiO 2 ) is between 0.01 and 0.23, The mass ratio of the total content of BaO and SrO to the total content of CaO and MgO (BaO + SrO) / (CaO + MgO) is between 0 and 2.

50. Nb 2 O 5 Ta 2 O 5 and WO 3 The total content of La 2 O 3 , Gd 2 O 3 and Y 2 O 3 Mass ratio of total content (Nb 2 O 5 +Ta 2 O 5 +WO 3 ) / (La 2 O 3 +Gd 2 O 3 +Y 2 O 3 ) is between 0 and 0.40, The refractive index nd is 1.7700 to 1.8210. The Abbe number vd is between 29.00 and 39.

00. The specific gravity is 3.05 to 4.

10. λ 80 The range is 392-545 nm, λ 70 The wavelength is 367-455 nm. λ 5 The wavelength range is 341–369 nm.

6. The optical glass according to claim 1, which satisfies at least one of the following conditions. SiO 2 The content is 13 to 40% by mass. ZrO 2 The content is 5 to 20% by mass. Nb 2 O 5 The content is 0 to 6% by mass, TiO 2 The content is 11 to 40% by mass. The CaO content is 6 to 40% by mass. B 2 O 3 The content is 1 to 30% by mass, La 2 O 3 The content is 0 to 23% by mass, Li 2 The oxygen content is 0 to 4% by mass. Y 2 O 3 The content is 0 to 26% by mass, The BaO content is 0 to 26% by mass. The SrO content is 0 to 16% by mass. The MgO content is 0 to 8% by mass. Na 2 The oxygen content is 0 to 7% by mass. K 2 The oxygen content is 0 to 4% by mass. Ta 2 O 5 The content is 0 to 6% by mass, WO 3 The content is 0 to 6% by mass, Gd 2 O 3 The content is 0 to 6% by mass, The ZnO content is 0 to 16% by mass. ZrO 2 and TiO 2 Total content of SiO 2 and B 2 O 3 The mass ratio of the total content (ZrO 2 +TiO 2 ) / (SiO 2 +B 2 O 3 ) is between 0.60 and 1.00, Li 2 O, Na 2 O and K 2 The mass ratio of the total O content to the CaO content (Li 2 O + Na 2 O+K 2 O) / CaO is 0.02 to 0.30, La 2 O 3 , Gd 2 O 3 and Y 2 O 3 Total content of ZrO 2 and TiO 2 Mass ratio of total content (La 2 O 3 +Gd 2 O 3 +Y 2 O 3 ) / (ZrO 2 +TiO 2 ) is between 0.30 and 0.92, SiO 2 SiO content 2 and B 2 O 3 Mass ratio of SiO to total content 2 / (SiO 2 +B 2 O 3 ) is between 0.44 and 0.94, La 2 O 3 , Gd 2 O 3 and Y 2 O 3 Total content of B 2 O 3 Mass ratio to content (La 2 O 3 +Gd 2 O 3 +Y 2 O 3 ) / B 2 O 3 The range is 0.75 to 2.

00. Li 2 O, Na 2 O and K 2 Total O content of SiO 2 Mass ratio to content (Li 2 O + Na 2 O+K 2 O) / SiO 2 The values ​​range from 0.04 to 0.

22. ZrO with CaO content 2 and TiO 2 Mass ratio of CaO / (ZrO) to total content 2 +TiO 2 ) is between 0.20 and 1.05, Li 2 O, Na 2 O and K 2 Total O content of ZrO 2 and TiO 2 Mass ratio of total content (Li 2 O + Na 2 O+K 2 O) / (ZrO) 2 +TiO 2 ) is between 0.02 and 0.17, The mass ratio of the total content of BaO and SrO to the total content of CaO and MgO (BaO + SrO) / (CaO + MgO) is between 0 and 2.

05. Nb 2 O 5 Ta 2 O 5 and WO 3 The total content of La 2 O 3 , Gd 2 O 3 and Y 2 O 3 Mass ratio of total content (Nb 2 O 5 +Ta 2 O 5 +WO 3 ) / (La 2 O 3 +Gd 2 O 3 +Y 2 O 3 ) is between 0 and 0.36, The refractive index nd is 1.7800 to 1.8160. The Abbe number vd is between 30.00 and 37.

00. The specific gravity is 3.10 to 4.

00. λ 80 The wavelength range is 396-540 nm. λ 70 The wavelength is 369-450 nm. λ 5 The wavelength range is 343–367 nm.

7. The optical glass according to claim 1, which satisfies at least one of the following conditions. SiO 2 The content is 15 to 36% by mass. ZrO 2 The content is 6 to 15% by mass. Nb 2 O 5 The content is 0 to 5% by mass. TiO 2 The content is 14 to 30% by mass. The CaO content is 9 to 35% by mass. B 2 O 3 The content is 2 to 20% by mass, La 2 O 3 The content is 0 to 22% by mass, Li 2 The oxygen content is 0 to 3% by mass. Y 2 O 3 The content is 0 to 24% by mass, The BaO content is 0 to 24% by mass. The MgO content is 0-7% by mass. Na 2 The oxygen content is 0 to 5% by mass. K 2 The oxygen content is 0 to 2% by mass. Ta 2 O 5 The content is 0 to 2% by mass, WO 3 The content is 0 to 2% by mass, Gd 2 O 3 The content is 0 to 2% by mass, The ZnO content is 0 to 14% by mass. La 2 O 3 , Gd 2 O 3 and Y 2 O 3 Total content of ZrO 2 and TiO 2 Mass ratio of total content (La 2 O 3 +Gd 2 O 3 +Y 2 O 3 ) / (ZrO 2 +TiO 2 ) is between 0.40 and 0.87, La 2 O 3 , Gd 2 O 3 and Y 2 O 3 Total content of B 2 O 3 Mass ratio to content (La 2 O 3 +Gd 2 O 3 +Y 2 O 3 ) / B 2 O 3 The values ​​are 0.85 to 1.

90. Li 2 O, Na 2 O and K 2 Total O content of SiO 2 Mass ratio to content (Li 2 O + Na 2 O+K 2 O) / SiO 2 The values ​​are 0.08 to 0.

18. ZrO with CaO content 2 and TiO 2 Mass ratio of CaO / (ZrO) to total content 2 +TiO 2 ) is between 0.40 and 0.90, Li 2 O, Na 2 O and K 2 Total O content of ZrO 2 and TiO 2 Mass ratio of total content (Li 2 O + Na 2 O+K 2 O) / (ZrO) 2 +TiO 2 ) is between 0.04 and 0.11, The mass ratio of the total content of BaO and SrO to the total content of CaO and MgO (BaO + SrO) / (CaO + MgO) is between 0 and 1.

60. Nb 2 O 5 Ta 2 O 5 and WO 3 The total content of La 2 O 3 , Gd 2 O 3 and Y 2 O 3 Mass ratio of total content (Nb 2 O 5 +Ta 2 O 5 +WO 3 ) / (La 2 O 3 +Gd 2 O 3 +Y 2 O 3 ) is between 0 and 0.32, The Abbe number vd is between 30.00 and 36.

00. The specific gravity is 3.15 to 3.

80. λ 80 The wavelength is 400-530 nm. λ 70 The range is 371-445 nm. λ 5 The wavelength range is 345–365 nm.

8. The optical glass according to claim 1, which satisfies at least one of the following conditions. K 2 The O content is 0% by mass. Ta 2 O 5 The content is 0% by mass, WO 3 The content is 0% by mass, Gd 2 O 3 The content is 0% by mass, La 2 O 3 , Gd 2 O 3 and Y 2 O 3 Total content of ZrO 2 and TiO 2 Mass ratio of total content (La 2 O 3 +Gd 2 O 3 +Y 2 O 3 ) / (ZrO 2 +TiO 2 The value is between 0.50 and 0.

82.

9. An optical element comprising the optical glass described in any one of claims 1 to 8.

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