JP2024001857A - Optical glass and optical element - Google Patents

Abstract

To provide an optical glass having excellent intrinsic quality and suitable for precision press working.SOLUTION: An optical glass according to the present invention comprises, in wt.%, SiO2: 17-47%, B2O3: 20-50%, Al2O3: 0.5-8%, ZnO: 0.5-8%, RO: 6-45%, La2O3+Y2O3+Gd2O3: 0.5-15%, and Li2O+Na2O+K2O: less than 15%, with ZnO/(La2O3+Y2O3+Gd2O3) of 0.2-4.0, where the RO is the total content of BaO, SrO, CaO, and MgO. Through reasonable component design, the inventive optical glass has a low yield point temperature and excellent intrinsic quality while having an expected refractive index and Abbe number.

Description

TECHNICAL FIELD The present invention relates to optical glass, and particularly to optical glass that has excellent intrinsic quality and is suitable for precision press processing, and glass preforms, optical elements, and optical instruments manufactured therefrom.

Optical glass is a glass material used for manufacturing lenses, prisms, mirrors, windows, etc. in optical equipment and mechanical systems. Currently, the main method of manufacturing optical glass as an optical element is precision press molding (including direct press method and secondary press method), and lenses manufactured using precision press technology require grinding and polishing. Since it is not necessary, it can reduce the consumption of raw materials, reduce human and material costs, and reduce environmental pollution. Therefore, using this technology, optical elements can be produced in large quantities at low cost. Precision pressing is the process of press-molding a glass preform with a high-precision mold having a predetermined product shape at a constant temperature and pressure to obtain a glass product with the shape and optical function of the finished product. Precision press technology allows us to manufacture a variety of optical glass products, including spherical lenses, aspheric lenses, prisms, and diffraction gratings.

With the rapid development of technologies such as smart driving and facial recognition, the demand for optical aspheric lenses with a refractive index of 1.57 to 1.61 and an Abbe number of 58 to 64 has rapidly increased. In addition, the intrinsic quality of optical glass is extremely important for its application, and superior optical glass products are required to have low porosity and even contain no air bubbles. Optical glass aspherical precision press processing technology can obtain aspherical lenses at low cost, so it has a refractive index of 1.57 to 1.61, an Abbe number of 58 to 64, excellent intrinsic quality, and is suitable for precision press processing. The development of optical glass has important significance for the development of the optoelectronic industry.

The technical problem to be solved by the present invention is to provide an optical glass that has excellent intrinsic quality and is suitable for precision press processing.

The technical solutions adopted by the present invention to solve the technical problems are as follows.

(1) Optical glass containing the following in weight%: SiO ₂ : 17-47%, B ₂ O ₃ : 20-50%, Al ₂ O ₃ : 0.5-8%, ZnO: 0.5-8 %, RO: 6-45%, La ₂ O ₃ + Y ₂ O ₃ + Gd ₂ O ₃ : 0.5-15%, Li ₂ O + Na ₂ O + K ₂ O: less than 15%, ZnO/(La ₂ O ₃ +Y ₂ O ₃ +Gd ₂ O ₃ ) is 0.2 to 4.0, and the RO is the total content of BaO, SrO, CaO, and MgO.

(2) The optical glass according to (1), further comprising the following components in weight%: P ₂ O ₅ : 0 to 3%, and/or ZrO ₂ : 0 to 3%, and/or clarifier: 0 ~1%, and the refining agent is one or more of Sb ₂ O ₃ , SnO ₂ , Na ₂ SiF ₆ , and K ₂ SiF ₆ .

(3) Optical glass containing SiO ₂ , B ₂ O ₃ , Al ₂ O ₃ , ZnO and alkaline earth metal oxides, further containing the following components in weight%: 0.5-15% La ₂ O ₃ +Y ₂ O ₃ +Gd ₂ O ₃ , ZnO/(La ₂ O ₃ +Y ₂ O ₃ +Gd ₂ O ₃ ) is 0.2 to 4.0, and the refractive index n _d of the optical glass is 1. 57 to 1.61, the Abbe number ν _d is 58 to 64, and the degree of bubbles is A class or higher.

(4) Optical glass according to (3), containing the following components in weight%: SiO ₂ : 17 to 47%, and/or B ₂ O ₃ : 20 to 50%, and/or Al ₂ O ₃ : 0.5 to 8%, and/or ZnO: 0.5 to 8%, and/or RO: 6 to 45%, and/or Li ₂ O + Na ₂ O + K ₂ O: less than 15%, and/or P ₂ O ₅ : 0 to 3%, and/or ZrO ₂ : 0 to 3%, and/or clarifier: 0 to 1%, and the RO is the total content of BaO, SrO, CaO, and MgO; _The agent is one or more _{of Sb2O3} , _{SnO2 , Na2SiF6} , _K2SiF6 .

(5) The optical glass according to one of (1) to (4), which contains the following components in weight% and satisfies one or more of the following seven conditions:
1) B ₂ O ₃ /SiO ₂ is 0.55 to 2.3, preferably B ₂ O ₃ /SiO ₂ is 0.7 to 2.0, more preferably B ₂ O ₃ /SiO ₂ is 0.8. ~1.8, more preferably B ₂ O ₃ /SiO ₂ is 1.0 to 1.5;
2) (ZrO ₂ + Al ₂ O ₃ )/B ₂ O ₃ is 0.05 to 0.4, preferably (ZrO ₂ + Al ₂ O ₃ )/B ₂ O ₃ is 0.05 to 0.3, more preferably (ZrO ₂ + Al ₂ O ₃ )/B ₂ O ₃ is 0.05 to 0.25, more preferably (ZrO ₂ + Al ₂ O ₃ )/B ₂ O ₃ is 0.05 to 0.2;
3) BaO/RO is 0.4 to 0.95, preferably BaO/RO is 0.5 to 0.95, more preferably BaO/RO is 0.65 to 0.95, even more preferably BaO/RO is 0.7-0.9;
4) RO/B ₂ O ₃ is 0.3 to 1.3, preferably RO/B ₂ O ₃ is 0.4 to 1.2, more preferably RO/B ₂ O ₃ is 0.5 to 1. 0, more preferably RO/B ₂ O ₃ is 0.6 to 0.9;
5) (La ₂ O ₃ +Y ₂ O ₃ +Gd ₂ O ₃ )/RO is 0.05 to 0.9, preferably (La ₂ O ₃ +Y ₂ O ₃ +Gd ₂ O ₃ )/RO is 0.1 to 0.9. 0.6, more preferably (La ₂ O ₃ +Y ₂ O ₃ +Gd ₂ O ₃ )/RO is 0.1 to 0.4, even more preferably (La ₂ O ₃ +Y ₂ O ₃ +Gd ₂ O ₃ )/ RO is 0.1-0.35;
6) ZnO/(La ₂ O ₃ +Y ₂ O ₃ +Gd ₂ O ₃ ) is 0.3 to 3.0, preferably ZnO/(La ₂ O ₃ +Y ₂ O ₃ +Gd ₂ O ₃ ) is 0.5 to 3.0. 2.0, more preferably ZnO/(La ₂ O ₃ + Y ₂ O ₃ + Gd ₂ O ₃ ) is 0.6 to 1.6;
7) (Na ₂ O+K ₂ O)/Li ₂ O is 0.1 to 1.5, preferably (Na ₂ O+K ₂ O)/Li ₂ O is 0.1 to 1.0, more preferably (Na ₂ O+K ₂ O)/Li ₂ O is 0.2 to 0.8, more preferably (Na ₂ O+K ₂ O)/Li ₂ O is 0.25 to 0.65;
The RO is the total content of BaO, SrO, CaO, and MgO.

(6) Optical glass according to any one of (1) to (4), containing the following components in weight%: SiO ₂ : 22 to 40%, preferably SiO ₂ : 25 to 38%, and/ or B ₂ O ₃ : 22 to 38%, preferably B ₂ O ₃ : 23 to 35%, and/or Al ₂ O ₃ : 1 to 7%, preferably Al ₂ O ₃ : 1 to 6.5%, and/or ZnO: 1 to 7%, preferably ZnO: 1 to 6%, and/or RO: 8 to 40%, preferably RO: 10 to 35%, and/or La ₂ O ₃ + Y ₂ O ₃ + Gd ₂ O ₃ : 1 to 12%, preferably La ₂ O ₃ + Y ₂ O ₃ + Gd ₂ O ₃ : 2 to 10%, and/or Li ₂ O + Na ₂ O + K ₂ O: less than 12%, preferably Li ₂ O + Na ₂ O+K ₂ O: less than 10%, more preferably Li ₂ O + Na ₂ O + K ₂ O: less than 8%, and/or P ₂ O ₅ : 0 to 1.5%, and/or ZrO ₂ : 0 to 2%, preferably is ZrO ₂ :0 to 1%, and/or clarifying agent: 0 to 0.8%, preferably clarifying agent: 0 to 0.5%, and the RO is the total content of BaO, SrO, CaO, and MgO. The clarifying agent is one or more of Sb ₂ O ₃ , SnO ₂ , Na ₂ SiF ₆ , and K ₂ SiF ₆ .

(7) Optical glass according to any one of (1) to (4), containing the following components in weight%: BaO: 5 to 30%, preferably BaO: 6 to 28%, more preferably BaO :8 to 25%, and/or SrO: 0.5 to 15%, preferably SrO: 0.5 to 13%, more preferably SrO: 0.5 to 12%, and/or CaO: 0 to 10%. , preferably CaO: 0-9%, more preferably CaO: 0-8%, and/or MgO: 0-5%, preferably MgO: 0-3%, and/or La ₂ O ₃ : 0.5. ~10%, preferably La ₂ O ₃ : 1 to 9%, more preferably La ₂ O ₃ : 1.5 to 8%, and/or Y ₂ O ₃ : 0 to 8%, preferably Y ₂ O ₃ : 0 to 5%, more preferably Y ₂ O ₃ : 0 to 3%, and/or Gd ₂ O ₃ : 0 to 5%, preferably Gd ₂ O ₃ : 0 to 3%, and/or Li ₂ O : 1 to 7%, preferably Li ₂ O: 2 to 6.5%, more preferably Li ₂ O: 3 to 5.5%, and/or Na ₂ O: 0.1 to 7%, preferably Na ₂ O: 0.1 to 6%, more preferably Na ₂ O: 0.5 to 5%, and/or K ₂ O: 0 to 5%, preferably K ₂ O: 0 to 2%, more preferably K ₂ O: 0 to 1%.

(8) The optical glass according to any one of (1) to (4), further comprising the following components in weight%: F: 0 to 10%, preferably F: 0 to 5%, more preferably F: 0 to 3%.

(9) Any of (1) to (4) whose components do not contain P ₂ O ₅ , and/or do not contain MgO, and/or do not contain Gd ₂ O ₃ , and/or do not contain F. Optical glass described in one of the above.

(10) The refractive index n _d is 1.57 to 1.61, preferably 1.575 to 1.605, more preferably 1.575 to 1.60, and the Abbe number ν _d is 58 to 64, preferably 58. The optical glass according to any one of (1) to (4), which has a molecular weight of 5 to 63.5, more preferably 59 to 63.

(11) N _d consistency within ±50×10 ⁻⁵ , preferably N _d consistency within ±30×10 ⁻⁵ , and/or T _s stability within ±5°C, preferably T _s stability The optical glass according to any one of (1) to (4), wherein the temperature is within ±3°C.

(12) Yield point temperature T _s is 610°C or lower, preferably 600°C or lower, more preferably 595°C or lower, and/or thermal expansion coefficient α _20-300°C is 85×10 ⁻⁷ or lower, preferably 83×10 ^-7 or less, more preferably 81 x 10 ^-7 or less, and/or acid resistance stability D _A is class 5 or higher, preferably class 4 or higher, and/or water resistance stability D _W is class 4 or higher, preferably class 3. or above, and/or the degree of pores is above A class, preferably above A ₀ class, more preferably above A ₀₀ class, and/or has a stripe C class above, preferably above B class, and/or has a high temperature viscosity of 1200°C. 25 dPaS or less, preferably 23 dPaS or less, more preferably 20 dPaS or less, and/or the high temperature viscosity at 900°C is 35 dPaS or more, preferably 40 dPaS or more, more preferably 50 dPaS or more, and/or the upper limit crystal temperature is 1100°C or less, preferably 1050°C or less, more preferably 1020°C or less, and/or thermoplastic crystallization stability is class B or higher, preferably class A, and/or refractive index temperature coefficient dn/dt is 6.0×10 ^-6 /°C The optical glass according to any one of (1) to (4), wherein the temperature is preferably 5.5×10 ⁻⁶ /°C or less, more preferably 5.0×10 ⁻⁶ /°C or less.

(13) A glass preform manufactured from the optical glass according to any one of (1) to (12).

(14) An optical element manufactured using the optical glass according to one of (1) to (12) or the glass preform according to (13).

(15) An optical device comprising the optical glass according to one of (1) to (12) and/or the optical element according to (14).

The beneficial effects of the present invention are as follows. Through rational component design, the optical glass obtained by the present invention has a desired refractive index and Abbe number, as well as a low yield point temperature and excellent intrinsic quality.

Hereinafter, embodiments of the optical glass according to the present invention will be described in detail, but the present invention is not limited to the embodiments described below, and may be implemented with appropriate modifications within the scope of the purpose of the present invention. is possible. Furthermore, although some omissions may be made as appropriate, the gist of the present invention is not limited by repeating the description. Below, the optical glass of the present invention may be simply referred to as glass.

[Optical glass]
Below, the range of components of the optical glass of the present invention will be explained. In this manual, the content of each component and the total content are expressed in weight percent (wt%) unless otherwise specified. That is, the content of each component and the total content are expressed in percent by weight based on the total weight of the glass material converted into the oxidized composition. Here, "converted into an oxide composition" means that the oxide, complex salt, hydroxide, etc. used as the raw material for the optical glass composition of the present invention decomposes during melting and is converted into an oxide. This is when the total weight of the oxide material is taken as 100%.

Specifically, numerical ranges set forth herein include upper and lower limits, and "greater than" and "less than" include endpoint values, and all whole numbers and fractions included in the range. It is not intended to be limiting to the specific values listed if included or limited in scope. References herein to "and/or" are inclusive, eg, "A and/or B" means only A, only B, or both A and B.

<Essential and optional ingredients>
_SiO2 is a necessary component of the glass of the present invention, and if its content exceeds 47%, the refractive index and Abbe number of the glass will be lower than the design requirements. On the other hand, when the melting temperature of glass increases rapidly, the degree of melting difficulty increases, especially when it contains a large amount of alkali metal oxide components, the erosion ability of glass to the melting furnace increases rapidly, reducing the service life of the furnace body. At the same time, the degree of difficulty in controlling N _d consistency and T _s stability increases, and there is a risk that the content of bubbles and inclusions in the glass will increase, and quality requirements may not be met. If the content of _SiO2 is less than 17%, the chemical stability of the glass will decrease rapidly, the water resistance will not meet the design requirements, and atomized defects will occur on the surface when polishing aspherical preforms. This reduces the yield rate of aspherical preforms. Therefore, the content of SiO ₂ is 17 to 47%, preferably 22 to 40%, more preferably 25 to 38%.

B ₂ O ₃ can improve the refractive index and Abbe number of the glass, and lower the T _s of the glass. By adding _an appropriate amount of _B2O3 to form a glass network at the same time as _SiO2 , the strength of the glass network can be further improved, and the chemical stability of the glass, especially the acid resistance of the glass, can be further improved. . When the content of B ₂ O ₃ exceeds 50%, the glass network becomes loose due to B ₂ O ₃ and the water resistance rapidly decreases. During production, _B2O3 is usually introduced in the form of boric acid, and after extensive research the inventors found that high content _of boric acid accelerates erosion into the melting furnace during melting. , while in dissolution, excess boric acid intensifies the volatilization, the glass composition changes significantly, and the N _d consistency and T _s stability decrease rapidly. Furthermore, boric acid decomposes to H ₂ O during dissolution, and H ₂ O is usually present in the hot glass liquid in the form of bubbles, and excess boric acid poses a great challenge to the subsequent clarification step. When the content of B ₂ O ₃ is less than 20%, the Abbe number and T _s of the glass cannot easily meet the design requirements. Therefore, the content of B ₂ O ₃ is 20 to 50%, preferably 22 to 38%, more preferably 23 to 35%.

As a result of repeated research by the inventors, in the glass system of the present invention, when the value of B ₂ O ₃ /SiO ₂ is greater than 2.3, the time required for the glass liquid to cool from liquid to solid at the molding temperature is significantly reduced. During molding, the surface cools and hardens first, but the temperature in the middle part is still high, and the time difference between the surface and middle part hardens is very large, and it is easy to form stripes inside the glass, especially for thick products. I found it to be serious. The glass system of the present invention usually has a forming temperature of 900-1000°C, and within this temperature range, if its viscosity is less than 35 dPas, the glass is prone to the above problems, and the stripes do not meet the requirements. be. Therefore, the value of B ₂ O ₃ /SiO ₂ is preferably 2.3 or less, more preferably 2.0 or less, still more preferably 1.8 or less, even more preferably 1.5 or less. If the value of B ₂ O ₃ /SiO ₂ is less than 0.55, the T _s of the glass will rise rapidly, making it difficult to achieve the design target, and at the same time, the high temperature viscosity of the glass of 1200 °C will exceed the design. Difficulty achieving goals. In some embodiments, if the high temperature viscosity of the glass at 1200 °C is too large, it is very difficult to eliminate air bubbles inside the glass, and the temperature needs to be increased to effectively eliminate air bubbles. However, the ability of glass liquid at 1200°C or higher to corrode the furnace body rapidly increases. Therefore, the value of B ₂ O ₃ /SiO ₂ is preferably 0.55 or more, more preferably 0.7 or more, still more preferably 0.8 or more, even more preferably 1.0 or more.

A suitable amount of _Al2O3 can strengthen the glass network, increase the chemical stability of the glass, and increase the high temperature viscosity of _the glass. However, in the glass of the present invention, when adding more than 8% _Al2O3 , the network structure in the glass quickly becomes loose, producing an _aspherical preform, especially when the _{B2O3 content} is relatively high. During the polishing process, corrosion points are likely to occur on the element surface, resulting in a rapid drop in the yield rate. Furthermore, since Al ₂ O ₃ has a large dispersion, if it is contained excessively, the Abbe number may become lower than the design requirement. If the content is less than 0.5%, the corrosiveness to the furnace body during the glass raw material melting process will rapidly increase, and at the same time, the chemical stability, especially water resistance, will rapidly decrease. Therefore, the content of Al ₂ O ₃ is limited to 0.5 to 8%, preferably 1 to 7%, more preferably 1 to 6.5%.

By adding _ZrO2 to glass, it is possible to reduce the erosive ability of the glass liquid to the furnace body, extend the service life of the melting furnace, and increase the crystallization resistance of the glass. When the content of ZrO ₂ exceeds 3%, insoluble matter tends to appear in the glass, the intrinsic quality of the glass deteriorates, and the crystallization resistance of the glass rapidly decreases. Therefore, the content of ZrO ₂ is 3% or less, preferably 2% or less, more preferably 1% or less.

In some embodiments, the use of _a mixture of _ZrO2 and _Al2O3 has a significant effect on the structural state of _B2O3 , especially when the content of alkaline earth metal oxides is _high , and the glass Affects thermoplastic crystallization stability. When the value of (ZrO ₂ + Al ₂ O ₃ )/B ₂ O ₃ is less than 0.05, increasing the thermoplastic crystallization resistance stability is not significant, and (ZrO ₂ + Al ₂ O ₃ )/B ₂ O When the value of ₃ is greater than 0.4, the thermoplastic crystallization stability of the glass is rather rapidly reduced. Therefore, the value of (ZrO ₂ +Al ₂ O ₃ )/B ₂ O ₃ is preferably 0.05 to 0.4, more preferably 0.05 to 0.3, even more preferably 0.05 to 0.25, Even more preferably it is 0.05 to 0.2.

A suitable amount of ZnO can significantly improve the refractive index and chemical stability of the glass, and reduce the thermal expansion coefficient and _Ts of the glass, and when its content is less than 0.5%, the above effects are remarkable. isn't it. When the ZnO content exceeds 8%, especially when the B ₂ O ₃ content is relatively high, the Abbe number of the glass becomes difficult to meet the design requirements, and the bubble elimination ability of the glass decreases. Therefore, the ZnO content is 0.5 to 8%, preferably 1 to 7%, more preferably 1 to 6%.

BaO, SrO, CaO, and MgO are alkaline earth metal oxides, and an appropriate amount of alkaline earth metal oxides can increase the refractive index of glass and strengthen the crystallization stability of glass, but their total content If the amount RO exceeds 45%, the anti-crystallization stability of the glass decreases rapidly and the glass even emulsifies. Therefore, the total content RO of BaO, SrO, CaO, and MgO is 6 to 45%, preferably 8 to 40%, and more preferably 10 to 35%.

As a result of a large amount of experimental research, the inventors found that BaO>SrO>CaO>MgO in terms of the ability to improve the crystallization stability of glass. Therefore, in the glass of the present invention, it is preferable to use BaO to improve the refractive index and crystallization resistance stability of the glass, but if the content exceeds 30%, the water resistance of the glass decreases rapidly, and the glass Bubbles are easily deposited during melting and are difficult to eliminate, seriously affecting the stability of the production process, and further affecting the _Nd consistency and _Ts stability of the glass. When the BaO content is less than 5%, the refractive index of the glass becomes difficult to meet the design requirements, and the crystallization stability of the glass rapidly decreases. Therefore, the BaO content is 5 to 30%, preferably 6 to 28%, more preferably 8 to 25%.

SrO forms a synergistic effect with BaO in the glass, which is advantageous in improving the crystallization resistance stability of the glass more effectively and increasing the refractive index of the glass. If the content is less than 5%, the above-mentioned effects are not significant, and if the content exceeds 15%, the synergistic effect of anti-crystallization weakens and the cost of the glass increases rapidly. Therefore, the content of SrO is 0.5 to 15%, preferably 0.5 to 13%, more preferably 0.5 to 12%.

CaO can improve the crystallization resistance stability of glass, increase the refractive index of glass, rapidly lower the high temperature viscosity of glass, and make bubble elimination relatively easy, especially when the relative content of BaO is low. The effect is relatively significant. When the content of CaO exceeds 10%, the crystallization stability of the glass rapidly decreases, and the Abbe number becomes lower than the design requirements. Therefore, the content of CaO is 0 to 10%, preferably 0 to 9%, more preferably 0 to 8%.

Although MgO can improve the stability of glass, if its content exceeds 5%, the crystallization resistance of the glass will decrease rapidly, and the Abbe number will become lower than the design requirements. Therefore, the MgO content is limited to 5% or less, preferably 3% or less, and more preferably MgO is not included.

In some embodiments, the alkaline earth metal oxide of the glass of the present invention is primarily BaO, and the BaO/RO value is preferably between 0.4 and 0.95, more preferably between 0.5 and 0. 95, more preferably from 0.65 to 0.95, even more preferably from 0.7 to 0.9, the lowering of the upper limit crystallization temperature of the glass due to the synergistic effect between the alkaline earth metal oxides is most remarkable. be.

In some embodiments, the free oxygen provided by alkaline earth metal oxides can strengthen the _B2O3 network, enhance its compactness, and further improve _the water and weather resistance of the glass. However, when the value of RO/B ₂ O ₃ is less than 0.3, the above-mentioned effect is not significant and the coefficient of thermal expansion increases. If the value of RO/B ₂ O ₃ exceeds 1.3, the excessive alkaline earth metal component will destroy the glass network, and the water resistance and weather resistance of the glass will rapidly decrease. Therefore, the value of RO/B ₂ O ₃ is preferably 0.3 to 1.3, more preferably 0.4 to 1.2, even more preferably 0.5 to 1.0, even more preferably 0.6. ~0.9.

La ₂ O ₃ can increase the refractive index of glass and reduce the high temperature viscosity of glass, but when its content is less than 0.5%, the above effects are not significant. When the content of La ₂ O ₃ exceeds 10%, the acid resistance of the glass decreases rapidly, the thermoplastic crystallization resistance of the glass decreases rapidly, and the T _s of the glass increases. Therefore, the content of La ₂ O ₃ is 0.5 to 10%, preferably 1 to 9%, more preferably 1.5 to 8%.

Y ₂ O ₃ can improve the refractive index and thermal shock resistance by adding it to glass, but when its content exceeds 8%, the chemical stability of the glass rapidly decreases. Therefore, the content of Y ₂ O ₃ is limited to 8% or less, preferably 5% or less, more preferably 3% or less.

Gd ₂ O ₃ can improve the refractive index, water resistance and weather resistance of glass, but if its content exceeds 5%, the cost of the glass will increase rapidly and the crystallization resistance will decrease rapidly. Therefore, the content of Gd ₂ O ₃ is limited to 5% or less, preferably 3% or less, and more preferably Gd ₂ O ₃ is not included.

The glass of the present invention requires a longer time to cool from a high temperature solution to a solid state than general optical glasses, and then requires two additional high temperature forming processes, so that excessive La ₂ O ₃ , Y ₂ O ₃ , and Gd ₂ The addition of _O3 rapidly reduces the thermoplastic crystallization resistance of the glass, which generates crystals during thermoplastic processing and further emulsification, causing a rapid decline in acid resistance. Therefore, the total content of La ₂ O ₃ , Y ₂ O ₃ , and Gd ₂ O ₃ (La ₂ O ₃ +Y ₂ O ₃ +Gd ₂ O ₃₎ is preferably 0.5 to 15%, more preferably 1 to 12%, More preferably, it is 2 to 10%.

In some embodiments, appropriate amounts of La ₂ O ₃ , Y ₂ O ₃ , Gd ₂ O ₃ and RO can enhance the refractive index and Abbe number of the glass, and more importantly, a large amount of RO can increase the refractive index and Abbe number of the glass. At the same time, it is advantageous to control the acid resistance within the design range, reduce the high-temperature viscosity of the glass, and further lower the melting temperature of the glass, while reducing the problem of decreased glass water resistance caused by (La ₂ O ₃ +Y ₂ O ₃ +Gd ₂ O ₃ )/RO is less than 0.05, the above effect is not significant. When the value of (La ₂ O ₃ + Y ₂ O ₃ + Gd ₂ O ₃ )/RO exceeds 0.9, the erosivity of the glass liquid to the furnace body increases, the stability of the glass rapidly decreases, and T _s increases, making it difficult to meet design requirements. Therefore, the value of (La ₂ O ₃ + Y ₂ O ₃ + Gd ₂ O ₃ )/RO is preferably 0.05 to 0.9, more preferably 0.1 to 0.6, and still more preferably 0.1 to 0. .4, more preferably 0.1 to 0.35.

In some embodiments, the presence of components such as La ₂ O ₃ , Y ₂ O ₃ , Gd ₂ O ₃ in the glass reduces the stability of the glass and makes it more susceptible to the generation of microscopic bubbles upon cooling; May cause product waste. As a result of a large amount of experimental research conducted by the inventors, we found that ZnO coexists with La ₂ O ₃ , Y ₂ O ₃ , and Gd ₂ O ₃ , and that ZnO/(La ₂ O ₃ + Y ₂ O ₃ + Gd ₂ O ₃ ) It has been found that when the value is within the range of 0.2 to 4.0, the stability of the glass and the degree of porosity can be prevented from decreasing. Therefore, the value of ZnO/(La ₂ O ₃ + Y ₂ O ₃ + Gd ₂ O ₃ ) is preferably 0.2 to 4.0, more preferably 0.3 to 3.0, even more preferably 0.5 to 2. .0, more preferably 0.6 to 1.6.

Alkali metal oxides (Li ₂ O, Na ₂ O, K ₂ O, etc.) are one of the main components of the glass of the present invention, and their content and relative content are determined by the T _s , refractive index, Abbe It has a great influence on important indicators such as number, coefficient of thermal expansion, chemical stability and crystallization resistance.

From the perspective of the action of single alkali metal oxides, Li ₂ O has the strongest ability to lower the T _s of glass, and when its content is less than 1%, the T _s of the glass is higher than the design requirement, and the glass The chemical stability decreases rapidly and the high temperature viscosity of the glass increases rapidly. If the Li ₂ O content exceeds 7%, it not only rapidly increases the corrosivity of the glass liquid to the furnace body, but also erodes the platinum product during melting, generates platinum inclusions in the glass, and at the same time The degree of difficulty in controlling N _d consistency and T _s stability becomes relatively high. Therefore, the content of Li ₂ O is 1 to 7%, preferably 2 to 6.5%, more preferably 3 to 5.5%.

A suitable amount of Na ₂ O can improve the melting performance of glass, lower the T _s of glass, and reduce the high temperature viscosity of glass, but if its content is less than 0.1%, the above effects will not be achieved. is not significant. If the content of Na ₂ O exceeds 7%, the erosivity of the glass to the furnace body increases, the chemical stability of the glass decreases, and at the same time the thermal expansion coefficient increases rapidly. Therefore, the content of Na ₂ O is 0.1 to 7%, preferably 0.1 to 6%, more preferably 0.5 to 5%.

When the content of K ₂ O exceeds 5%, the glass network structure is severely destroyed, making it difficult for the water resistance and weather resistance of the glass to meet the design requirements. Therefore, the content of K ₂ O is limited to 5% or less, preferably 2% or less, more preferably 1% or less.

As a result of repeated research by the inventors, it was found that when three types of alkali metal oxides, Li ₂ O, Na ₂ O, and K ₂ O, are present in a mixture, a complex synergistic effect occurs, causing corrosion to the furnace body. It was found that the temperature coefficient of refraction, high temperature viscosity, and refractive index temperature coefficient were further influenced. By using aspheric lenses, it is possible to achieve high-definition imaging while significantly reducing the number of lenses used. However, for lenses used in environments with relatively large temperature differences (vehicles, safety lenses, etc.), the temperature coefficient of refraction of the glass is too large, and if the number of lenses is small, the "temperature drift" of the lens is extremely difficult to control. This creates a serious problem in that the imaging quality differs at different temperatures. The inventors have found that in some embodiments, the value of Li ₂ O + Na ₂ O + K ₂ O is preferably less than 15%, more preferably less than 12%, even more preferably less than 10%, even more preferably less than 8%. It has been found that when , the erosivity of the glass liquid to the furnace body is reduced, the T _s stability meets the design requirements, and the temperature coefficient of refractive index of the glass does not exceed the design requirements.

In some embodiments, the value of (Na ₂ O + K ₂ O)/Li ₂ O is preferably between 0.1 and 1.5, more preferably between 0.1 and 1.0, even more preferably between 0.2 and 0. .8, more preferably 0.25 to 0.65, the erosivity of the glass liquid to the furnace body is reduced, the T _s stability meets the design requirements, and the temperature coefficient of refractive index of the glass meets the design requirements. It cannot be exceeded. More importantly, if the above three types of alkali metal oxides are within the above range, a lower coefficient of thermal expansion can also be achieved, which is very helpful in reducing lens rupture in aspherical stamping. It is important for this purpose, and greatly improves the flexibility and stability of aspheric press processing.

_P2O5 can adjust the refractive index and dispersion of the glass, but in the glass system of the present invention, if its _content exceeds 3%, the crystallization resistance of the glass will rapidly decrease, and the melting of the glass will deteriorate. Since it has a devastating effect on important processes such as production, blank secondary press processing, and aspheric precision press processing, its content is limited to 3% or less, preferably 1.5% or less, and more preferably P. ₂ O ₅ is not included.

An appropriate amount of F (fluorine) can significantly lower the T _s of the glass, increase the Abbe number of the glass, and reduce the use of alkali metal oxides in the glass. When its content exceeds 10%, F is extremely volatile during high-temperature melting, and its unit content has a particularly large effect on the refractive index and Abbe number, so the _Nd consistency and _Ts stability are affected during the melting process. This makes it extremely difficult to control, which has a devastating effect on the subsequent aspherical pressing process. Therefore, the F content is limited to 10% or less, preferably 5% or less, and more preferably 3% or less. If the component design can satisfy the design requirements of _Ts , it is more preferable not to include F.

Sb ₂ O ₃ , SnO ₂ , Na ₂ SiF ₆ , K ₂ SiF ₆ and the like can be used as fining agents and are advantageous in increasing the degree of porosity of glass, and when present alone or in combination, the content is 1% or less, preferably is 0.8% or less, more preferably 0.5% or less.

In addition to optimizing glass meltability and improving glass porosity through component design, similar high-viscosity silicate glasses typically introduce oxide components with nitrate to optimize glass meltability and porosity. become During the melting process of nitrates, most of the nitrogen elements are emitted into the atmosphere as _NOx gas, and nitrogen oxides are extremely harmful to human health, and long-term inhalation poses a risk of causing lung cancer. Therefore, the inventors are engaged in research to reduce nitrogen oxide emissions while guaranteeing glass melting performance. As a result of extensive experimental research by the present inventors, nitrates were introduced in the form of KNO ₃ and Ba(NO ₃ ) ₂ , and the above-mentioned fining agents (Sb ₂ O ₃ , SnO ₂ , Na ₂ SiF ₆ , It has been discovered that when used in combination with other materials (such as K ₂ SiF ₆ ), the degree of porosity of the glass can meet quality requirements and the emissions of nitrogen oxides can be reduced to lower levels. By conversion, the N (nitrogen) element content in the glass raw material (N element introduction amount when melting 100 kg of theoretical glass/100 kg glass weight x 100%) is less than 2.0%, preferably less than 1.5%, More preferably it is less than 1.0%.

<Ingredients that should not be included>
In the glass of the present invention, even when oxides of transition metals such as V, Cr, Mn, Fe, Co, Ni, Cu, Ag, and Mo are contained alone or in combination in small amounts, the glass is colored; Since specific wavelengths in the visible light region are absorbed, weakening the visible light transmission effect of the present invention, it is actually preferable not to include optical glass that particularly requires wavelength transmittance in the visible light region.

In recent years, the use of Th, Cd, Tl, Os, Be, and Se oxides has been controlled as hazardous chemicals, and they are used not only in the glass manufacturing process but also in the processing process and treatment of finished products. Efforts to protect the environment are necessary. Therefore, when placing importance on the impact on the environment, it is preferable not to include them unless they are unavoidably mixed. This makes the optical glass free from substances that actually pollute the environment. Therefore, the optical glass of the present invention can be manufactured, processed, and disposed of without taking special environmental measures. In order to be environmentally friendly, the optical glass of the present invention preferably does not contain As ₂ O ₃ and PbO.

The terms "not added," "not included," and "0%" as used herein mean that this component was not intentionally added as a raw material for the glass of the present invention. However, as raw materials and/or equipment for manufacturing glass, impurities and components that are not intentionally added may exist in small amounts or trace amounts in the final glass, and these are also covered by the patent of the present invention. Targeted.

Below, the performance of the optical glass of the present invention will be explained.
<Refractive index and Abbe number>
The refractive index (n _d ) and Abbe number (ν _d ) of optical glasses are tested according to the method specified in GB/T7962.1-2010. In some embodiments, the optical glasses of the present invention have a refractive index (n _d ) of 1.57 to 1.61, preferably a refractive index (n _d ) of 1.575 to 1.605, more preferably a refractive index of (n _d ) is 1.575 to 1.60. In some embodiments, the optical glass of the present invention has an Abbe number (ν _d ) of 58 to 64, preferably an Abbe number (ν _d ) of 58.5 to 63.5, more preferably an Abbe number (ν _d ) of 58.5 to 63.5. is 59-63.

< _Nd consistency>
A total of 5 glass samples were extracted every 24 hours during production, and after annealing, the refractive index (N _d ) was measured according to the method specified in GB/T7962.1-2010, and the difference from the standard value was N _d Consistency. In some embodiments, the optical glasses of the present invention have an N _d match of within ±50×10 ⁻⁵ , preferably an N _d match of within ±30×10 ⁻⁵ .

<Yield point temperature>
The yield point temperature (T _s ) of optical glass is measured according to the method specified in GB/T7962.16-2010. In some embodiments, the optical glass of the present invention has a yield point temperature (T _s ) of 610° C. or less, preferably a yield point temperature (T _s ) of 600° C. or less, more preferably a yield point temperature (T _s ) of 600° C. or less. The temperature is 595°C or less.

< _Ts stability>
A total of 5 glass samples are extracted every 24 hours during production, and after annealing, T _s is measured according to the method specified in GB/T7962.16-2010, and the difference from the standard value is considered T _s stability. . In some embodiments, the optical glasses of the present invention have a T _s stability within ±5°C, preferably a T _s stability within ±3°C.

<Thermal expansion coefficient>
The thermal expansion coefficient (α _20-300°C ) of optical glass is data measured at 20-300°C according to the method specified in GB/T7962.16-2010. In some embodiments, the optical glass of the present invention has a coefficient of thermal expansion (α _20-300°C ) of 85×10 ⁻⁷ or less, preferably a coefficient of thermal expansion (α _20-300°C ) of 83×10 ⁻⁷ or less , more preferably (α _20-300°C ) is 81×10 ⁻⁷ or less.

<Acid resistance stability>
The acid resistance stability (D _A ) (powder method) of optical glass is tested by the method specified in GB/T17129. In this specification, acid resistance stability may be referred to as acid resistance. In some embodiments, the optical glass of the present invention has an acid resistance stability (D _A ) of class 5 or higher, preferably an acid resistance stability (D _A ) of class 4 or higher.

<Water resistance stability>
The water resistance stability (D _W ) (powder method) of optical glass is tested by the method specified in GB/T17129. In this specification, water resistance stability may be referred to as water resistance. In some embodiments, the optical glass of the present invention has a water resistance stability (D _W ) of class 4 or higher, preferably a water resistance stability (D _w ) of class 3 or higher.

<Bubble degree>
The porosity of optical glass is tested according to the method specified in GB/T7962.8-2010. In some embodiments, the optical glass of the present invention has a bubble degree of A class or higher, preferably A ₀ class or higher, and more preferably A ₀₀ class.

<Stripe>
Stripes on optical glass are confirmed by comparing a standard sample from the direction where the stripes are most visible using a stripe meter consisting of a point light source and a lens. Grades are divided into four stages. Specifically, refer to Table 1. In some embodiments, the optical glass stripes of the present invention are of grade C or higher, preferably of grade B or higher.

<High temperature viscosity>
The high-temperature viscosity of optical glasses is tested according to the following method: tested by the rotation method using a THETA Rheotronic II high-temperature viscometer, the numerical unit is dPaS (poise), the lower the number, the lower the viscosity. . In some embodiments, the optical glass of the present invention has a high temperature viscosity at 1200° C. of 25 dPaS or less, preferably a 1200° C. high temperature viscosity of 23 dPaS or less, more preferably a 1200° C. high temperature viscosity of 20 dPaS or less. In some embodiments, the optical glass of the present invention has a high temperature viscosity at 900° C. of 35 dPaS or more, preferably a 900° C. high temperature viscosity of 40 dPaS or more, and more preferably a 900° C. high temperature viscosity of 50 dPaS or more.

<Crystallization resistance>
Glass used in aspherical precision press processing requires three stages of high-temperature processing, including high-temperature forming, high-temperature secondary press processing, and high-temperature precision press processing, so the crystallization resistance stability of the glass is extremely important. be. Crystallization resistance stability can be divided into two types. One is crystallization resistance during the process of cooling the glass liquid from a liquid to a solid state, and is represented by the upper limit temperature of crystallization. Crystallization resistance can be represented by a thermoplastic crystallization resistance test. Crystal resistance (or glass stability) as described herein generally refers to the two types of crystal resistance described above.

Crystallization resistance stability can be divided into two types. One is crystallization resistance during the process of cooling the glass liquid from a high temperature (1000 to 1200°C) liquid to a solid state, and is represented by the upper limit temperature of crystallization. Crystallization resistance during processing and high-temperature precision press processing can be represented by a thermoplastic crystallization resistance test.

The test method for the upper limit temperature of crystallization is as follows: Measure the crystallization performance of glass using the temperature gradient furnace method, polish the side of a 180 x 10 x 10 mm glass sample, and then The maximum temperature range of devitrification of the glass is 1400℃. This is the upper limit temperature of glass crystallization. In some embodiments, the upper limit crystal temperature of the optical glass of the present invention is 1100°C or lower, preferably 1050°C or lower, more preferably 1020°C or lower.

The thermoplastic crystallization resistance stability test method is as follows: A sample processed into a size of 20 x 20 x 10 mm is polished on both sides, placed in a crystal precipitation furnace at T _s +200°C, kept warm for 30 minutes, and taken out. After cooling, the two large surfaces were polished and the crystallization resistance performance of the glass was judged based on Table 2, with A grade being the best and E grade being the worst. In some embodiments, the optical glass of the present invention has thermoplastic crystallization stability of grade B or higher, preferably grade A, and has excellent crystallization resistance.

<Refractive index temperature coefficient>
The refractive index temperature coefficient (dn/dt) of the optical glass is determined according to the method specified in GB/T7962.4-2010. 10 ⁻⁶ /°C)). In some embodiments, the optical glass of the present invention has a refractive index temperature coefficient (dn/dt) of 6.0×10 ⁻⁶ /°C or less, preferably 5.5×10 ⁻⁶ /°C or less, more preferably It is 5.0×10 ⁻⁶ /°C or less.

[Production method]
The method for producing the optical glass of the present invention is as follows: The glass of the present invention can be prepared using oxides, hydroxides, fluorides, various salts (carbonates, nitrates, sulfates, phosphates, metaphosphates). ), boric acid, etc., manufactured using conventional raw materials, conventional processes, and compounded by conventional methods, the prepared furnace material is melted in a melting furnace (platinum, gold, or platinum alloy) at 1400 to 1550 °C. (e.g., a crucible) and melt it. Thereafter, the glass is clarified and homogenized to obtain a homogeneous molten glass without bubbles or unmelted substances, and this molten glass is cast in a mold and annealed. Those skilled in the art can appropriately select raw materials, manufacturing methods and process parameters according to actual needs.

[Glass preform and optical element]
A glass preform can be manufactured from optical glass created using a press molding method such as direct drop molding, polishing, or hot press molding. That is, we can manufacture molten optical glass into precision glass preforms by direct precision drop molding, we can manufacture glass preforms by mechanical processing such as grinding and polishing, or we can use optical glass to create preform blanks for press molding. This preform blank is then hot-pressed and polished to produce a glass preform. It should be noted that the means for manufacturing the optical preform is not limited to the above-mentioned means.

As described above, the optical glass of the present invention is useful for various optical elements and optical designs, and in particular, a blank is formed from the optical glass of the present invention, and this blank is used for hot press molding, precision press molding, etc. It is preferable to produce optical elements such as lenses, prisms, etc.

Both the optical preform and the optical element of the present invention are formed from the optical glass of the present invention. The optical preform of the present invention has the excellent properties of optical glass, and the optical element of the present invention has the excellent properties of optical glass, and various lenses with high optical value, Optical elements such as prisms can be provided.

Examples of lenses include various lenses such as concave meniscus lenses, convex meniscus lenses, biconvex lenses, biconcave lenses, plano-convex lenses, and plano-concave lenses, each having a spherical or aspheric lens surface. The lens according to the invention further includes a lens for an automobile lamp.

[Optical equipment]
The optical element made of optical glass of the present invention can be used for manufacturing optical equipment including, but not limited to, photographic devices, imaging devices, projection devices, display devices, vehicle-mounted devices (including lamps), monitoring devices, etc. .

<Optical glass example>
In order to more clearly explain the technical solution of the present invention, the following non-limiting examples are provided.

In this example, optical glasses having the compositions shown in Tables 3 to 5 are obtained using the optical glass manufacturing method described above. Further, the characteristics of each glass were measured by the test method described in the present invention, and the results are shown in Tables 3 to 5.

<Glass preform example>
The glasses obtained in Optical Glass Examples 1 to 20 are processed into concave meniscus lenses, convex meniscus lenses, biconvex lenses, biconcave lenses, and plano-convex lenses by using press forming means such as polishing, hot press molding, and precision press molding. , various lenses such as plano-concave lenses, and preforms such as prisms.

<Optical element example>
The preform obtained in the above optical preform example is tempered, and the refractive index is finely adjusted while reducing the strain inside the glass so that the optical properties such as the refractive index reach a desired value.

Next, each preform is ground and polished to produce various lenses and prisms such as concave meniscus lenses, convex meniscus lenses, biconvex lenses, biconcave lenses, plano-convex lenses, and plano-concave lenses. An antireflection film can also be applied to the surface of the obtained optical element.

<Example of optical equipment>
Optical elements manufactured in the optical element embodiments described above can be used in imaging devices, sensors, microscopes, pharmaceutical technology, digital Projection, communications, optical communication technology/information transmission, optics/illumination in the automotive sector, photolithography technology, excimer lasers, wafers, computer chips and integrated circuits and electronic devices containing such circuits and chips, or imaging equipment in the automotive sector and devices.

Claims (20)

SiO ₂ : 17-47%, B ₂ O ₃ : 20-50%, Al ₂ O ₃ : 0.5-8%, ZnO: 0.5-8%, RO: 6-45%, La ₂ O ₃ +Y ₂ O ₃ +Gd ₂ O ₃ : 0.5 to 15%, Li ₂ O + Na ₂ O + K ₂ O: less than 15%, ZnO/(La ₂ O ₃ +Y ₂ O ₃ +Gd ₂ O ₃ ): 0. Contains ingredients of 2 to 4.0,
The RO is the total content of BaO, SrO, CaO, and MgO. Optical glass. Further comprising the following components in weight%: P ₂ O ₅ : 0 to 3%, and/or ZrO ₂ : 0 to 3%, and/or clarifier: 0 to 1%,
The optical glass according to claim 1, wherein the clarifier _is one _or more _{of Sb2O3} , _SnO2 , _Na2SiF6 , and _K2SiF6 . An optical glass containing SiO ₂ , B ₂ O ₃ , Al ₂ O ₃ , ZnO and an alkaline earth metal oxide,
Components in weight%: La ₂ O ₃ + Y ₂ O ₃ + Gd ₂ O ₃ : 0.5 to 15%, ZnO/(La ₂ O ₃ + Y ₂ O ₃ + Gd ₂ O ₃ ): 0.2 to 4.0. further including;
The optical glass has a refractive index n _d of 1.57 to 1.61, an Abbe number ν _d of 58 to 64, and a bubble degree of class A or higher. SiO ₂ : 17-47%, and/or B ₂ O ₃ : 20-50%, and/or Al ₂ O ₃ : 0.5-8%, and/or ZnO: 0.5-8% in weight%. , and/or RO: 6 to 45%, and/or Li ₂ O + Na ₂ O + K ₂ O: less than 15%, and/or P ₂ O ₅ : 0 to 3%, and/or ZrO ₂ : 0 to 3%, and/or clarifying agent: 0 to 1%,
The RO is the total content of BaO, SrO, CaO, and MgO,
The optical glass according to claim ₃ , wherein _the clarifier _is one or more of _Sb2O3 , _SnO2 , _Na2SiF6 , and _K2SiF6 . The ingredients expressed in weight% are
1) B ₂ O ₃ /SiO ₂ is 0.55 to 2.3;
2) (ZrO ₂ +Al ₂ O ₃ )/B ₂ O ₃ is 0.05 to 0.4;
3) BaO/RO is 0.4-0.95;
4) RO/B ₂ O ₃ is 0.3 to 1.3;
5) (La ₂ O ₃ + Y ₂ O ₃ + Gd ₂ O ₃ )/RO is 0.05 to 0.9;
6) ZnO/(La ₂ O ₃ + Y ₂ O ₃ + Gd ₂ O ₃ ) is 0.3 to 3.0;
7) (Na ₂ O + K ₂ O)/Li ₂ O satisfies one or more of 0.1 to 1.5,
The optical glass according to any one of claims 1 to 4, wherein the RO is the total content of BaO, SrO, CaO, and MgO. The ingredients expressed in weight% are
1) B ₂ O ₃ /SiO ₂ is 0.7 to 2.0;
2) (ZrO ₂ +Al ₂ O ₃ )/B ₂ O ₃ is 0.05 to 0.3;
3) BaO/RO is 0.5-0.95;
4) RO/B ₂ O ₃ is 0.4 to 1.2;
5) (La ₂ O ₃ + Y ₂ O ₃ + Gd ₂ O ₃ )/RO is 0.1 to 0.6;
6) ZnO/(La ₂ O ₃ + Y ₂ O ₃ + Gd ₂ O ₃ ) is 0.5 to 2.0;
7) (Na ₂ O + K ₂ O)/Li ₂ O satisfies one or more of 0.1 to 1.0,
The optical glass according to any one of claims 1 to 4, wherein the RO is the total content of BaO, SrO, CaO, and MgO. The ingredients expressed in weight% are
1) B ₂ O ₃ /SiO ₂ is 0.8 to 1.8;
2) (ZrO ₂ +Al ₂ O ₃ )/B ₂ O ₃ is 0.05 to 0.25;
3) BaO/RO is 0.65-0.95;
4) RO/B ₂ O ₃ is 0.5 to 1.0;
5) (La ₂ O ₃ + Y ₂ O ₃ + Gd ₂ O ₃ )/RO is 0.1 to 0.4;
6) ZnO/(La ₂ O ₃ + Y ₂ O ₃ + Gd ₂ O ₃ ) is 0.6 to 1.6;
7) (Na ₂ O + K ₂ O)/Li ₂ O satisfies one or more of 0.2 to 0.8,
The optical glass according to any one of claims 1 to 4, wherein the RO is the total content of BaO, SrO, CaO, and MgO. The ingredients expressed in weight% are
1) B ₂ O ₃ /SiO ₂ is 1.0 to 1.5;
2) (ZrO ₂ +Al ₂ O ₃ )/B ₂ O ₃ is 0.05 to 0.2;
3) BaO/RO is 0.7-0.9;
4) RO/B ₂ O ₃ is 0.6 to 0.9;
5) (La ₂ O ₃ + Y ₂ O ₃ + Gd ₂ O ₃ )/RO is 0.1 to 0.35;
6) (Na ₂ O + K ₂ O)/Li ₂ O satisfies one or more of 0.25 to 0.65,
The optical glass according to any one of claims 1 to 4, wherein the RO is the total content of BaO, SrO, CaO, and MgO. SiO ₂ : 22 to 40%, and/or B ₂ O ₃ : 22 to 38%, and/or Al ₂ O ₃ : 1 to 7%, and/or ZnO: 1 to 7%, and/or RO: 8-40%, and/or La ₂ O ₃ + Y ₂ O ₃ + Gd ₂ O ₃ : 1-12%, and/or Li ₂ O + Na ₂ O + K ₂ O: less than 12%, and/or P ₂ O ₅ : 0 to 1.5%, and/or ZrO ₂ : 0 to 2%, and/or clarifying agent: 0 to 0.8%,
The RO is the total content of BaO, SrO, CaO, and MgO, and the refining agent is one or more of Sb ₂ O ₃ , SnO ₂ , Na ₂ SiF ₆ , and K ₂ SiF ₆ . Optical glass according to any one of the items. In weight percent, SiO ₂ : 25-38%, and/or B ₂ O ₃ : 23-35%, and/or Al ₂ O ₃ : 1-6.5%, and/or ZnO: 1-6%, and /or RO: 10-35%, and/or La ₂ O ₃ + Y ₂ O ₃ + Gd ₂ O ₃ : 2-10%, and/or Li ₂ O + Na ₂ O + K ₂ O: less than 8%, and/or ZrO ₂ :0 to 1%, and/or clarifying agent: 0 to 0.5%,
The RO is the total content of BaO, SrO, CaO, and MgO, and the refining agent is one or more of Sb ₂ O ₃ , SnO ₂ , Na ₂ SiF ₆ , and K ₂ SiF ₆ . Optical glass according to any one of the items. BaO: 5 to 30% by weight, and/or SrO: 0.5 to 15%, and/or CaO: 0 to 10%, and/or MgO: 0 to 5%, and/or La ₂ O ₃ : 0.5 to 10%, and/or Y ₂ O ₃ : 0 to 8%, and/or Gd ₂ O ₃ : 0 to 5%, and/or Li ₂ O: 1 to 7%, and/or Na ₂ The optical glass according to any one of claims 1 to 4, containing a component of O: 0.1 to 7% and/or K ₂ O: 0 to 5%. BaO: 8 to 25% by weight, and/or SrO: 0.5 to 12%, and/or CaO: 0 to 8%, and/or MgO: 0 to 3%, and/or La ₂ O ₃ : 1.5 to 8%, and/or Y ₂ O ₃ : 0 to 3%, and/or Gd ₂ O ₃ : 0 to 3%, and/or Li ₂ O: 3 to 5.5%, and/or The optical glass according to any one of claims 1 to 4, containing a component of Na 2 O: 0.5 to 5% and/or K _{2 O} : 0 to 1%. The optical glass according to any one of claims 1 to 4, further comprising a component of F: 0 to 5% by weight. The optical glass according to any one of claims 1 to 4, wherein the optical glass has a refractive index n _d of 1.57 to 1.61 and an Abbe number ν _d of 58 to 64. The optical glass according to any one of claims 1 to 4, wherein the optical glass has a refractive index n _d of 1.575 to 1.60 and an Abbe number ν _d of 59 to 63. The optical glass has an N _d consistency within ±50×10 ⁻⁵ , and/or a T _s stability within ±5 °C, and/or a yield point temperature T _s of 610 °C or less, and/or a thermal expansion coefficient α _20-300°C is 85×10 ^-7 or less, and/or acid resistance stability D _A is 5 or more, and/or water resistance stability D _W is 4 or more, and/or the degree of pores is A or more. Or the stripe is class C or higher, and/or the high temperature viscosity at 1200°C is 25 dPaS or less, and/or the high temperature viscosity at 900°C is 35 dPaS or more, and/or the upper limit crystal temperature is 1100°C or less, and/or the thermoplastic crystallization stability is stable. The optical glass according to any one of claims 1 to 4, which has a property of class B or higher and/or a refractive index temperature coefficient dn/dt of 6.0×10 ⁻⁶ /°C or lower. The optical glass has a N _d consistency within ±30×10 ⁻⁵ , a T _s stability within ±3 °C, and/or a yield point temperature T _s of 595 °C or less, and/or a thermal expansion coefficient α _20-300°C is 81×10 ^-7 or less, and/or acid resistance stability D _A is class 4 or higher, and/or water resistance stability D _W is class 3 or higher, and/or foam degree is A ₀₀ class, and/or Or the stripe is class B or higher, and/or the high temperature viscosity at 1200°C is 20 dPaS or less, and/or the high temperature viscosity at 900°C is 50 dPaS or more, and/or the upper limit crystal temperature is 1020°C or less, and/or the thermoplastic crystalline stability is stable. The optical glass according to any one of claims 1 to 4, which has a grade A property and/or a refractive index temperature coefficient dn/dt of 5.0×10 ⁻⁶ /°C or less. A glass preform manufactured from the optical glass according to any one of claims 1 to 4. An optical element manufactured from the optical glass according to any one of claims 1 to 4. An optical device comprising the optical glass according to any one of claims 1 to 4.