TWI779744B - Optical glass, glass preform and optical element - Google Patents

Abstract

The present invention provides an optical glass, a glass preform and an optical element and relates to the technical field of glass. The optical glass of the present invention is expressed in weight percentage and contains: SiO₂ : 5-12%; B₂ O₃ : 8-15%; Y₂ O₃ : 5 -15%; ZrO₂ : 1-10%; ZnO: 0.2-10%; La₂ O₃ : 40-55%; TiO₂ +WO₃ +Nb₂ O₅ : 5-20%, wherein TiO₂ /(TiO₂ +WO₃ +Nb₂ O₅ ) is 0.38-1.0, and the optical glass of the invention has high weather resistance and excellent refractive index temperature coefficient.

Description

Optical glass, glass preforms and optical components

The invention belongs to the technical field of glass, and in particular relates to an optical glass with a refractive index above 1.90 and an Abbe number above 30, as well as a glass preform and an optical element formed from the optical glass.

Optical components and optical instruments are developing rapidly in terms of miniaturization, integration and high precision, which puts forward higher requirements for the performance of optical glass used in optical instruments and optical components of equipment, especially in recent years, vehicle, monitoring security A large number of high-refractive-index optical glasses are used in fields such as automotive and security. Due to long-term exposure outdoors, the performance of the glass may deteriorate due to changes in outdoor temperature and humidity, resulting in a decline in imaging quality. Therefore, in the field of optoelectronic materials, there is an increasingly urgent need for high-refractive index optical glass to improve performance requirements such as weather resistance and temperature coefficient of refraction index.

Usually, high refractive index optical glasses with a refractive index n _d above 1.90 and an Abbe number v _d above 30 contain Ta, Gd and other elements, but Ta and Gd raw materials are expensive, which is not conducive to obtaining cost-effective materials.

Therefore, it is particularly necessary to develop optical glasses with a refractive index n _d above 1.90, an Abbe number v _d above 30, no precious elements such as Ta and Gd, and excellent performances such as weather resistance and temperature coefficient of refraction index.

The object of the present invention is to provide an optical glass with a refractive index n _d above 1.90, an Abbe number v _d above 30, no precious elements such as Ta and Gd, and more excellent performances such as weather resistance and temperature coefficient of refraction index.

The object of the invention is achieved through the following technical solutions:

(1) Optical glass, characterized in that its components are expressed in weight percent, containing: SiO ₂ : 5-12%; B ₂ O ₃ : 8-15%; Y ₂ O ₃ : 5-15%; ZrO ₂ : 1-10%; ZnO: 0.2-10%; La ₂ O ₃ : 40-55%; TiO ₂ +WO ₃ +Nb ₂ O ₅ : 5-20%, of which: TiO ₂ /(TiO ₂ +WO ₃ +Nb ₂ O ₅ ) is 0.38-1.0.

(2) The optical glass according to (1), the components of which are expressed in weight percent, also contain: RO: 0-10%; and/or high-temperature molten glass surface tension improver: 0-0.5%, the RO It is one or more of BaO, SrO, CaO, MgO, and the high-temperature molten glass surface tension improving agent is one or more of Sb ₂ O ₃ , SnO, SnO ₂ , and CeO ₂ components.

(3) Optical glass, its composition contains SiO ₂ , B ₂ O ₃ , Y ₂ O ₃ , ZrO ₂ , ZnO, La ₂ O ₃ , its composition is expressed in weight percentage, TiO ₂ +WO ₃ +Nb ₂ O ₅ : 5-20%, wherein: TiO ₂ /(TiO ₂ +WO ₃ +Nb ₂ O ₅ ) is 0.38-1.0, the refractive index n _d of the optical glass is above 1.90, and the Abbe number v _d is 30 Above, the weather resistance is Class 2 or above.

(4) The optical glass according to (3), the composition of which is expressed in weight percent, contains: SiO ₂ : 5-12%; and/or B ₂ O ₃ : 8-15%; and/or Y ₂ O ₃ : 5-15%; and/or ZrO ₂ : 1-10%; and/or ZnO: 0.2-10%; and/or La ₂ O ₃ : 40-55%; and/or RO: 0-10% and/or high temperature molten glass surface tension improving agent: 0-0.5%, the RO is one or more of BaO, SrO, CaO, MgO, and the high temperature molten glass surface tension improving agent is Sb ₂ O ₃ , SnO, SnO _2. One or more of CeO ₂ components.

(5) Optical glass, the composition of which is represented by weight percentage, consisting of SiO ₂ : 5-12%; B ₂ O ₃ : 8-15%; Y ₂ O ₃ : 5-15%; ZrO ₂ : 1-10% ; ZnO: 0.2-10%; La ₂ O ₃ : 40-55%; RO: 0-10%; high temperature glass liquid surface tension improver: 0-0.5% composition, TiO ₂ + WO ₃ + Nb ₂ O ₅ : 5-20%, wherein: TiO ₂ /(TiO ₂ +WO ₃ +Nb ₂ O ₅ ) is 0.38-1.0, the RO is one or more of BaO, SrO, CaO, MgO, and the surface tension of the high-temperature glass liquid is improved The agent is one or more of Sb ₂ O ₃ , SnO, SnO ₂ , and CeO ₂ components.

(6) The optical glass according to any one of (1) to (5), the components of which are expressed in weight percent, wherein: TiO ₂ +WO ₃ +Nb ₂ O ₅ : 5-14.8%; and/or TiO ₂ /(TiO ₂ +WO ₃ +Nb ₂ O ₅ ) is 0.4-1.0; and/or WO ₃ /TiO ₂ is less than 1.0; and/or TiO ₂ /(WO ₃ +Nb ₂ O ₅ ) is 0.6-15; And/or WO ₃ /La ₂ O ₃ is less than 0.05; and/or (SiO ₂ +La ₂ O ₃ +TiO ₂ )/(B ₂ O ₃ +WO ₃ +Nb ₂ O ₅ ) is 2.85-7.25.

(7) The optical glass according to any one of (1) to (5), the composition of which is expressed in weight percentage, wherein: SiO ₂ : 5-10%; and/or B ₂ O ₃ : 10-15%; and/or Y ₂ O ₃ : 7-14%; and/or ZrO ₂ : 2-8%; and/or ZnO: 0.5-8%; and/or La ₂ O ₃ : 40-52%; and/or RO: 0-5%; and/or high-temperature molten glass surface tension improver: 0-0.3%; the RO is one or more of BaO, SrO, CaO, MgO, and the high-temperature glass molten surface tension improver is Sb ₂ One or more of O ₃ , SnO, SnO ₂ , and CeO ₂ components.

(8) The optical glass according to any one of (1) to (5), the components of which are expressed in weight percent, wherein: TiO ₂ +WO ₃ +Nb ₂ O ₅ : 5-12%; and/or TiO ₂ /(TiO ₂ +WO ₃ +Nb ₂ O ₅ ) is 0.47-1.0; and/or WO ₃ /TiO ₂ is 0.4 or less; and/or TiO ₂ /(WO ₃ +Nb ₂ O ₅ ) is 0.6-14; And/or WO ₃ /La ₂ O ₃ is 0.03 or less; and/or (SiO ₂ +La ₂ O ₃ +TiO ₂ )/(B ₂ O ₃ +WO ₃ +Nb ₂ O ₅ ) is 2.85-7.0.

(9) The optical glass according to any one of (1) to (5), the composition of which is expressed in weight percentage, wherein: ZnO: 0.5-4.5%; and/or La ₂ O ₃ : 44-52%; and /or RO: 0-3%, the RO is one or more of BaO, SrO, CaO, MgO.

(10) The optical glass according to any one of (1) to (5), the components of which are expressed in weight percent, wherein: WO ₃ : 0-2.4%; and/or TiO ₂ : 6-15%; and/or or Nb ₂ O ₅ : 0-8%; and/or BaO: 0-5%; SrO: 0-5%; and/or CaO: 0-5%; and/or MgO: 0-5%.

(11) The optical glass according to any one of (1) to (5), the components of which are expressed in weight percent, wherein: WO ₃ : 0.1-2.4%; and/or TiO ₂ : 6-12%; and/or or Nb ₂ O ₅ : 0-7%; and/or BaO: 0-3%; SrO: 0-3%; and/or CaO: 0-3%; and/or MgO: 0-3%.

(12) The optical glass according to any one of (1) to (5), its components are expressed in weight percent, wherein: the total content of La ₂ O ₃ + Y ₂ O ₃ is 50-70%, preferably 54- 67%, more preferably 57-65%; and/or La ₂ O ₃ /Y ₂ O ₃ ≤5.90, preferably La ₂ O ₃ /Y ₂ O ₃ ≤5.10, more preferably La ₂ O ₃ /Y ₂ O ₃ ≤4.70.

(13) The optical glass according to any one of (1) to (5), whose components do not contain Gd ₂ O ₃ ; and/or do not contain Yb ₂ O ₃ ; and/or do not contain Ta ₂ O ₅ ; and/or do not contain RO.

(14) The optical glass according to any one of (1) to (5), wherein the optical glass has a refractive index n _d of 1.90 or more, preferably 1.90-1.95, more preferably 1.90-1.94; the Abbe number v _d is 30 Above, preferably 30-40.

(15) The optical glass according to any one of (1) to (5), wherein the weather resistance of the optical glass is at least Class 2, preferably Class 1; and/or the upper limit temperature of crystallization of the optical glass is 1250 °C or lower, preferably lower than 1200 °C; and/or the temperature coefficient of the refractive index is lower than 5.5×10 ^-6 /°C, preferably lower than 5.0×10 ^-6 /°C; and/or the degree of abrasion is 90-200, preferably 90 -160; and/or the acid resistance stability is above class 2, preferably class 1; and/or the Knoop hardness H _K is 650-750×10 ⁷ Pa, preferably 660-720×10 ⁷ Pa.

(16) A glass preform made of the optical glass described in any one of (1) to (15) above.

(17) An optical element made of the optical glass described in any one of (1) to (15) above or the glass preform described in (16).

(18) An optical instrument made of the optical glass described in any one of (1) to (15) above or the optical element described in (17).

The optical glass of the present invention has a refractive index n _d of more than 1.90, an Abbe number v _d of more than 30, does not use noble elements such as Ta and Gd, and has excellent performances such as weather resistance and temperature coefficient of refraction index.

Hereinafter, although embodiment of the optical glass of this invention is demonstrated in detail, this invention is not limited to the following embodiment, It can change suitably within the objective range of this invention, and can implement. In addition, with regard to the repeated description, although the description may be appropriately omitted, the gist of the invention will not be limited accordingly. In the following content, the optical glass of the present invention is sometimes simply referred to as glass.

[Optical glass]

The scope of each component (ingredient) of the optical glass of the present invention will be described below. In this specification, unless otherwise specified, the content of each component is expressed in weight percent (wt %) relative to the total amount of glass substances converted into an oxide composition. Here, the "composition in terms of oxides" refers to the case where oxides, composite salts, hydroxides, etc. used as raw materials for the optical glass composition of the present invention are decomposed and converted into oxides during melting , and the total amount of the oxide is taken as 100%.

Unless otherwise indicated in a specific instance, the numerical ranges set forth herein include the upper and lower values, "above" and "below" include the endpoints, and all integers and fractions within the range, without limitation. Specific values listed when limiting scope. The term "and/or" herein is inclusive, for example, "A and/or B" means only A, or only B, or both A and B.

<Essential Components and Optional Components>

SiO ₂ is an oxide that forms a glass network, and is an effective component for maintaining the meltability and flow viscosity of the glass. In addition, in order to effectively and stably maintain the glass structure and effectively improve the devitrification resistance, the content of SiO ₂ is limited. However, if the _SiO2 content exceeds 12%, the refractive index of the glass will decrease, the meltability will decrease, and the high refractive index glass of the present invention cannot be obtained, so the _SiO2 content is limited to 12% or less, preferably 10% %the following.

B ₂ O ₃ is an essential component of glass. It can form a glass skeleton with [SiO ₄ ], or it can form a skeleton alone. It has the effect of improving the stability of the glass structure. If its content is less than 8%, the glass forming ability will become poor. The anti-devitrification property deteriorates, and the glass is easy to devitrify; if the content of B ₂ O ₃ is greater than 15%, it will also reduce the refractive index of the glass and make it difficult to obtain the required high refractive index. Therefore, the content of B ₂ O ₃ in the present invention is 8-15%, preferably 10-15%.

Rare earth oxides such as La ₂ O ₃ , Y ₂ O ₃ , Gd ₂ O ₃ , and Yb ₂ O ₃ are the key components to obtain high-refractive index and low-dispersion glass, but too much introduction will cause deterioration of the anti-devitrification performance of the glass, making it difficult to obtain Good quality product. In order to obtain high refractive index and low dispersion characteristics, the coexistence of La ₂ O ₃ , Y ₂ O ₃ , and Gd ₂ O ₃ oxides is usually used to increase the amount introduced into the glass and improve the anti-devitrification performance of the glass. Gd ₂ O ₃ is a heavy rare earth, the price is lower than the light rare earth La ₂ O ₃ , Y ₂ O ₃ is expensive, Yb ₂ O ₃ will produce near-infrared intrinsic absorption in the glass, which will affect the imaging quality, so in order to improve the economical efficiency of the material , to reduce near-infrared absorption, the inventors found through hard experiments that, without using Gd ₂ O ₃ and Yb ₂ O ₃ , by using La ₂ O ₃ and Y ₂ O ₃ with a specific composition content, that is, La ₂ O The total content of ₃ + Y ₂ O ₃ is controlled within the range of 50-70% and La ₂ O ₃ /Y ₂ O ₃ ≤5.90, preferably the content of La ₂ O ₃ + Y ₂ O ₃ is 54-67%, La ₂ O ₃ /Y ₂ O ₃ ≤5.10, more preferably the content of La ₂ O ₃ + Y ₂ O ₃ is 57-65%, when La ₂ O ₃ /Y ₂ O ₃ ≤4.70, it can maintain the high refractive index and low dispersion of the glass , significantly increase the high-temperature viscosity of the glass, thereby significantly improving the anti-devitrification performance of the glass, and is conducive to obtaining a better glass forming viscosity and improving the internal streak level of the glass. Wherein, the La ₂ O ₃ content is limited to 40-55%, preferably 40-52%, and the Y ₂ O ₃ content is limited to 5-15%, preferably 7-14%.

TiO ₂ , Nb ₂ O ₅ , and WO ₃ are all effective ingredients for increasing the refractive index, and their coexistence can effectively adjust the optical constants of the glass and improve glass crystallization and coloring. Since TiO ₂ is a high refractive index and high dispersion component, if the content exceeds 15%, it is difficult to obtain a product with an Abbe number v _d greater than 30 while ensuring a high refractive index, and the loss resistance of the glass is significantly reduced during processing and heat treatment, so The content of _TiO2 is limited to 6-15%, preferably 6-12%. If the Nb ₂ O ₅ content exceeds 8%, the thermal stability of the glass will decrease, so the Nb ₂ O ₅ content is limited to 8% or less, preferably 7% or less. When the WO ₃ content is higher than 2.4%, the light transmittance of the glass in the short-wavelength region of the visible light region deteriorates. Therefore, the upper limit of the WO ₃ content is 2.4%, and the preferred content is 0.1-2.4%.

In some embodiments of the present invention, the total content of TiO ₂ , WO ₃ , and Nb ₂ O ₅ TiO ₂ +WO ₃ +Nb ₂ O ₅ is controlled between 5-20%, which can make the glass obtain the desired high refraction rate while improving the coloring degree of the glass, if the TiO ₂ +WO ₃ +Nb ₂ O ₅ exceeds 20%, the coloring of the glass will increase and the devitrification resistance will deteriorate; further, control the TiO ₂ +WO ₃ +Nb ₂ O ₅ in Between 5-14.8%, more preferably 5-12%, the glass can obtain more excellent coloring degree and improve thermal stability.

In some embodiments of the present invention, controlling TiO ₂ /(TiO ₂ +WO ₃ +Nb ₂ O ₅ ) between 0.38-1.0 will greatly improve the weather resistance of the glass, which is very important for the glass to be used outdoors. Very favorable; further, preferably TiO ₂ /(TiO ₂ +WO ₃ +Nb ₂ O ₅ ) is 0.4-1.0, more preferably 0.47-1.0.

In some embodiments of the present invention, by setting TiO ₂ /(WO ₃ +Nb ₂ O ₅ ) between 0.6-15, the phase separation of glass can be prevented, and the volatilization of components at high temperature can be reduced; further control of TiO ₂ / (WO ₃ +Nb ₂ O ₅ ) between 0.6-14, the glass has better acid resistance stability.

In some embodiments of the present invention, when the content ratio of WO ₃ and TiO ₂ ie WO ₃ /TiO ₂ is controlled below 1.0, especially below 0.4, the gloss and devitrification resistance of the glass are better, and the optical glass can also be made Obtain better grinding performance, make the glass wear degree between 90-200, which is more conducive to optical grinding of glass. More preferably, when the lower limit of WO ₃ /TiO ₂ is greater than 0, it is more beneficial to the clarification of the optical glass and the elimination of air bubbles.

During the experiment, the inventor found that by controlling the ratio between the total content of SiO ₂ , La ₂ O ₃ and TiO ₂ and the total content of B ₂ O ₃ , WO ₃ and Nb ₂ O ₅ (ie: (SiO ₂ + La ₂ O ₃ +TiO ₂ )/(B ₂ O ₃ +WO ₃ +Nb ₂ O ₅ )) is between 2.85-7.25, which can better adjust the mutual transition between [BO ₃ ] and [BO ₄ ] and stabilize Glass properties, improve chemical stability, heat resistance stability, reduce glass crystallization tendency, crystallization upper limit temperature can be better controlled below 1250 °C, further, by controlling (SiO ₂ +La ₂ O ₃ +TiO ₂ )/ (B ₂ O ₃ +WO ₃ +Nb ₂ O ₅ ) is between 2.85-7.0, and the ideal Knoop hardness H _K can also be obtained, so that H _K is between 650×10 ⁷ -750×10 ⁷ Pa, both It is conducive to improving the mechanical strength of the glass, and is also conducive to subsequent grinding and cold processing.

The La ₂ O ₃ field is strong and the radius is large, so it is easy to accumulate and reduce the scope of glass production. In some embodiments of the present invention, by controlling the ratio of WO ₃ /La ₂ O ₃ to less than 0.05, preferably less than 0.03, an ideal temperature coefficient of the refractive index can be obtained, so that the dn/dt of the glass is lower, and the refractive index of the glass is affected by the temperature The impact of changes is small, which is more conducive to outdoor high-temperature use. It can also better solve the problem of streaks caused by crystallization and clarified viscosity in the process of glass smelting. Glass streaks are easier to eliminate.

ZrO2 can greatly improve the system stability of high _- refractive index borate glass, and has superior alkali resistance. Appropriate introduction can significantly improve the chemical stability of glass. The present invention obtains the above-mentioned effects by introducing more than ₁ % ZrO2; If the content of ZrO2 is greater _than 10%, the difficulty of melting will increase greatly, and stones will easily form inside the glass. Therefore, the content of ZrO2 is limited to 1-10%, preferably _2-8 %.

ZnO in the glass system of the present invention can reduce the high-temperature viscosity of the glass, promote the elimination of bubbles and the melting of refractory raw materials in the raw materials, and improve the gloss of the glass very well. The present invention obtains the above effects by introducing not less than 0.2% of ZnO If ZnO exceeds 10%, glass is difficult to obtain required high refractive index, and glass is eroded to smelting crucible and increases, therefore the content of ZnO is limited to 0.2-10% in the present invention, is preferably 0.5-8%, more preferably in 0.5-4.5%.

The introduction of RO (RO is one or more of BaO, SrO, CaO, and MgO) can play a role in fluxing and improve moisture resistance stability, but too much content will make it difficult to obtain the required high refractive index and deteriorate the glass. Anti-devitrification properties. Therefore, the present invention limits the RO content to 0-10%, preferably 0-5%, more preferably 0-3%, and further preferably does not contain RO. Wherein, the respective contents of BaO, SrO, CaO, and MgO are limited to 0-5%, preferably 0-3%, more preferably not contained.

The present invention increases the high-temperature viscosity of the glass through the above-mentioned various creative measures, and improves the crystallization resistance of the glass, but the increase of the high-temperature viscosity of the glass has some adverse effects on the elimination of glass bubbles. By using sulfate and halogen element compounds in the glass as high-temperature glass liquid surface tension improvers, although it can eliminate air bubbles, sulfate decomposition and halide volatilization at high temperatures will produce sulfides that are harmful to the atmospheric environment. , halides (such as fluoride) and other substances, so it is not suitable to use. The inventors have found through arduous experiments that the problem of glass bubbles can be solved by reducing the gas in the raw materials, increasing the clarification temperature, and prolonging the clarification time. The inventor also found that by adding one or more trace components of Sb ₂ O ₃ , SnO, SnO ₂ , and CeO ₂ components in the glass, it can be obviously Reduce the surface tension of the molten glass at high temperature, which is beneficial to the escape of bubbles in the molten glass, so that a glass product with good bubbles can be obtained under the conditions of a lower temperature for eliminating bubbles and a shorter time for eliminating bubbles. Therefore, in the present invention, the total content of Sb ₂ O ₃ , SnO, SnO ₂ , and CeO ₂ is controlled below 0.5%, and exceeding 0.5% will be detrimental to the glass transmittance, and the total content is preferably below 0.3%. Among them, the content of Sb ₂ O ₃ is 0-0.1%, preferably 0-0.05%; the content of SnO ₂ is 0-0.5%, preferably 0-0.3%; the content of SnO is 0-0.5%, preferably 0% ~0.3%; the content ratio of CeO ₂ is basically the same as that of SnO ₂ , and its content is 0-0.5%, preferably 0-0.3%, and more preferably not contained.

Ta ₂ O ₅ has the effect of increasing the refractive index, and its effect on maintaining low dispersion of the glass is better than that of Nb ₂ O ₅ . If the stability of the glass needs to be further improved, a small amount of Ta ₂ O ₅ can be introduced to replace part of Nb ₂ O ₅ . However, compared with other components, Ta ₂ O ₅ is very expensive, so the present invention reduces its usage in view of practicality and cost. The content of Ta ₂ O ₅ in the present invention is 0-5%, more preferably not contained.

＜Components that should not be contained＞

In the glass of the present invention, even if oxides of transition metals such as V, Cr, Mn, Fe, Co, Ni, Cu, Ag, and Mo are contained alone or in a small amount in combination, the glass will be colored, and the glass will be colored in the visible and near Specific wavelengths in the infrared region absorb, thereby weakening the properties of the glass of the present invention to increase the visible light transmittance effect. Therefore, especially for optical glasses that require transmittance in the visible region wavelengths, it is preferable not to contain it substantially.

Oxides of Th, Cd, Tl, Os, Be, and Se have tended to be controlled and used as harmful chemical substances in recent years, not only in the manufacturing process of glass, but also in the process of processing and disposal after production. Measures are required. Therefore, when emphasis is placed on the influence on the environment, it is preferable not to contain them substantially except for unavoidable mixing. Thereby, the optical glass becomes practically free of environmental polluting substances. Therefore, the optical glass of the present invention can be manufactured, processed, and discarded 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 "does not contain" and "0%" described herein mean that no such compound, molecule or element is intentionally added as a raw material to the optical glass of the present invention; but as a raw material and/or equipment for producing optical glass, there will be some Impurities or components that are not intentionally added may be contained in small or trace amounts in the final optical glass, and this situation is also within the protection scope of the patent of the present invention.

Next, the performance and testing method of the optical glass of the present invention will be described.

1. Refractive index n _d and Abbe number v _d

Refractive index and Abbe number are tested according to the method specified in GB/T7962.1-2010.

The optical glass of the present invention has a refractive index ( _nd ) of 1.90 or more, preferably 1.90-1.95, more preferably 1.90-1.94, and an Abbe number (v _d ) of 30 or more, preferably 30-40.

2. Crystallization upper limit temperature

The crystallization performance of glass is measured by the temperature gradient furnace method. The glass is made into a sample of 180*10*10mm, the side is polished, and it is placed in a furnace with a temperature gradient (5°C/cm) and heated to 1400°C for 4 hours and then taken out. Naturally cool to room temperature, observe the crystallization of the glass under a microscope, the highest temperature corresponding to the appearance of crystals in the glass is the crystallization upper limit temperature of the glass. The lower the crystallization upper limit temperature of the glass, the stronger the stability of the glass at high temperature, and the better the production process performance.

The crystallization upper limit temperature of the optical glass of the present invention is not higher than 1250°C, preferably not higher than 1200°C.

3. Weather resistance CR

Place the sample in a test box in a saturated water vapor environment with a relative humidity of 90%, and cycle alternately at 40°C~50°C every 1h for 15 cycles. The weather resistance category is divided according to the amount of turbidity change before and after the sample is placed. The turbidity refers to the deterioration layer such as "white spot" or "cloudy" on the surface of the colorless optical glass after being eroded by the atmosphere. The erosion degree of the glass surface is determined by measuring the turbidity difference before and after the erosion of the sample. The turbidity measurement is carried out with an integrating sphere turbidity meter with a relative error of haze indication within ±5%. The following table 1 shows the classification of weather resistance:

Table 1 Weather resistance classification category 1 2 3 4 a b c Turbidity increase △H (%) <0.3 0.3-1.0 1.0-2.0 2.0-4.0 4.0-6.0 ≥6.0

The weather resistance (CR) of the optical glass of the present invention is Class 2 or higher, preferably Class 1.

4. Refractive index temperature coefficient

The temperature coefficient of refraction index (dn/dt) is tested according to the method specified in GB/T 7962.4-2010, and the temperature coefficient of refraction index of the d-line at 40-60 °C is measured.

The temperature coefficient of refractive index (dn/dt) of the present invention is 5.5×10 ^-6 /°C or less, preferably 5.0×10 ^-6 /°C or less.

5. Acid resistance stability RA(S) (surface method)

The acid resistance stability RA(S) (surface method) of the optical glass of the present invention is tested according to the method specified in GB/T 7962.14-2010.

The RA(S) of the optical glass of the present invention is at least two types, preferably one type.

6. Abrasion (F _A )

Abrasion degree refers to the value obtained after multiplying the ratio of the wear amount of the sample to the wear amount (volume) of the standard sample (K9 optical glass) by 100 under exactly the same conditions, expressed as:

F _A =V/V ₀ ×100=(W/ρ)÷(W ₀ /ρ ₀ )×100 In the formula, V and V ₀ represent the volume wear of the tested sample and the standard sample, respectively, and W and W ₀ represent The quality wear of the tested sample and the standard sample, ρ and ρ ₀ represent the density of the tested sample and the standard sample, respectively.

The abrasion degree of the glass of the present invention is in the range of 90-200, preferably in the range of 90-160.

7. Knoop hardness H _K

Knoop hardness is measured according to the test method specified in GB/T 7962.18-2010.

The Knoop hardness H _K of the present invention is 650×10 ⁷ -750×10 ⁷ Pa, preferably 660×10 ⁷ -720×10 ⁷ Pa.

Example

The present invention will be described below with reference to specific embodiments. It should be noted that these embodiments are only illustrative and do not limit the present invention in any way.

In order to obtain glasses with the compositions shown in Table 2 to Table 4, the oxides in the table (including but not limited to carbonates, nitrates, hydroxides, oxides, boric acid, etc.) The corresponding raw materials are weighed in proportion, mixed thoroughly to become blended raw materials, put the blended raw materials into platinum (or platinum alloy) crucibles, heated to 1250~1500°C, melted, stirred and clarified to form a uniform Melt the glass, then pour the molten glass into a preheated mold after cooling down moderately, keep it near the glass transition temperature for 2 to 4 hours, and then slowly cool it to obtain optical glass. Moreover, the characteristic of each glass was measured by the method shown above, and the measurement result is shown in Table 2 - Table 4.

Table 2 wt% Example 1 2 3 4 5 6 7 8 9 10 SiO ₂ 6.00 5.24 7.50 8.20 4.23 6.00 4.23 6.80 6.51 7.10 B ₂ O ₃ 15.00 13.71 13.20 11.20 13.71 13.90 14.32 12.00 11.88 12.10 La ₂ O ₃ 52.00 49.35 51.50 47.00 49.35 48.00 49.01 47.60 44.36 48.80 Y ₂ O ₃ 9.90 11.40 11.40 9.50 11.40 12.50 11.40 9.40 14.40 10.50 TiO ₂ 5.00 5.23 6.50 10.70 6.02 7.10 6.02 6.10 7.13 6.50 Nb ₂ O ₅ 3.50 4.01 4.01 4.85 6.50 4.85 5.50 5.22 6.00 WO ₃ 2.30 1.80 1.80 0.80 1.80 0.60 2.10 1.94 1.00 _ZrO2 4.70 4.89 3.49 4.80 4.37 5.20 4.52 5.80 4.52 5.50 ZnO 1.50 4.27 0.50 7.80 4.27 0.80 5.05 2.80 4.04 2.50 BaO 1.90 SrO 0.05 CaO MgO 0.05 Gd ₂ O ₃ Ta ₂ O ₅ Sb ₂ O ₃ 0.05 0.05 _SnO2 0.10 WO ₃ /TiO ₂ 0.46 0.34 0.28 0.07 0.30 0.00 0.10 0.34 0.27 0.15 TiO ₂ +WO ₃ +Nb ₂ O ₅ 10.80 11.04 12.31 11.50 12.67 13.60 11.47 13.70 14.29 13.50 TiO ₂ /(WO ₃ +Nb ₂ O ₅ ) 0.86 0.90 1.12 13.38 0.91 1.09 1.10 0.80 1.00 0.93 TiO ₂ /(TiO ₂ +WO ₃ +Nb ₂ O ₅ ) 0.46 0.47 0.53 0.93 0.48 0.52 0.52 0.45 0.50 0.48 WO ₃ /La ₂ O ₃ 0.04 0.04 0.03 0.02 0.04 0.00 0.01 0.04 0.04 0.02 (SiO ₂ +La ₂ O ₃ +TiO ₂ )/(B ₂ O ₃ +WO ₃ +Nb ₂ O ₅ ) 3.03 3.06 3.45 5.49 2.93 3.00 3.00 3.09 3.05 3.27 La ₂ O ₃ +Y ₂ O ₃ 61.90 60.75 62.90 56.50 60.75 60.50 60.41 57.00 58.76 59.30 La ₂ O ₃ /Y ₂ O ₃ 5.25 4.33 4.52 4.95 4.33 3.84 4.30 5.06 3.08 4.65 total 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 Refractive index n _d 1.9070 1.9055 1.9016 1.9123 1.9183 1.9080 1.9086 1.9068 1.9036 1.9089 Abbe number v _d 35.63 35.93 36.01 34.77 35.36 35.31 36.31 35.46 34.76 35.38 Crystallization upper limit temperature (°C) 1100 1205 1210 1195 1190 1190 1190 1185 1200 1190 Weather resistance CR Class 2 Class 1 Class 1 Class 1 Class 1 Class 1 Class 1 Class 2 Class 1 Class 1 Abrasion degree F _A 168 139 140 139 145 140 145 140 155 135 Acid Stability RA Class 1 Class 1 Class 1 Class 1 Class 1 Class 1 Class 1 Class 1 Class 1 Class 1 Refractive index temperature coefficient dn/dt(×10 ^-6 /℃) 4.5 4.6 4.2 4.2 4.4 4.1 4.1 4.6 4.5 4.0 Knoop hardness H _K (×10 ⁷ Pa) 678 685 695 699 701 689 691 679 685 692

table 3 wt% Example 11 12 13 14 15 16 17 18 19 20 SiO ₂ 5.88 5.88 8.20 8.20 8.50 5.88 8.23 7.90 7.28 8.40 B ₂ O ₃ 12.35 12.35 11.20 10.55 10.00 12.35 11.05 11.50 12.03 11.00 La ₂ O ₃ 43.62 45.11 44.50 51.28 51.10 49.66 51.38 47.80 50.00 47.00 Y ₂ O ₃ 13.22 13.42 9.50 11.03 9.34 13.37 10.10 11.90 9.63 9.50 TiO ₂ 7.33 7.33 8.20 5.31 8.98 7.33 6.51 5.40 7.01 9.50 Nb ₂ O ₅ 5.22 5.22 5.00 3.39 5.22 3.91 7.00 7.11 2.00 WO ₃ 1.94 1.33 0.80 1.75 0.60 1.13 1.62 0.88 _ZrO2 5.42 4.52 4.80 3.77 3.68 4.02 4.11 5.50 4.02 4.80 ZnO 5.02 4.84 7.80 4.22 7.21 1.04 3.09 3.00 2.04 7.80 BaO SrO 0.5 CaO 0.54 MgO Gd ₂ O ₃ Ta ₂ O ₅ Sb ₂ O ₃ 0.05 _SnO2 WO ₃ /TiO ₂ 0.26 0.18 0.10 0.33 0.07 0.15 0.25 0.00 0.13 0.00 TiO ₂ +WO ₃ +Nb ₂ O ₅ 14.49 13.88 14.00 10.45 9.58 13.68 12.04 12.40 15.00 11.50 TiO ₂ /(WO ₃ +Nb ₂ O ₅ ) 1.02 1.12 1.41 1.03 14.97 1.15 1.18 0.77 0.88 4.75 TiO ₂ /(TiO ₂ +WO ₃ +Nb ₂ O ₅ ) 0.51 0.53 0.59 0.51 0.94 0.54 0.54 0.44 0.47 0.83 WO ₃ /La ₂ O ₃ 0.04 0.03 0.02 0.03 0.01 0.02 0.03 0.00 0.02 0.00 (SiO ₂ +La ₂ O ₃ +TiO ₂ )/(B ₂ O ₃ +WO ₃ +Nb ₂ O ₅ ) 2.91 3.09 3.58 4.13 6.47 3.36 3.99 3.30 3.21 4.99 La ₂ O ₃ +Y ₂ O ₃ 56.84 58.53 54.00 62.31 60.44 63.03 61.48 59.70 59.63 56.50 La ₂ O ₃ /Y ₂ O ₃ 3.30 3.36 4.68 4.65 5.47 3.71 5.09 4.02 5.19 4.95 total 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 Refractive index n _d 1.9002 1.9038 1.9093 1.9017 1.9128 1.9263 1.9007 1.9078 1.9105 1.9038 Abbe number v _d 34.59 34.90 34.18 35.86 35.48 34.87 35.88 35.49 34.79 35.03 Crystallization upper limit temperature (°C) 1185 1200 1190 1205 1210 1190 1195 1195 1200 1185 Weather resistance CR Class 1 Class 1 Class 1 Class 1 Class 1 Class 1 Class 1 Class 2 Class 2 Class 1 Abrasion degree F _A 152 149 142 154 143 150 144 139 146 143 Acid Stability RA Class 1 Class 1 Class 1 Class 1 Class 2 Class 1 Class 1 Class 1 Class 1 Class 1 Refractive index temperature coefficient dn/dt(×10 ^-6 /℃) 4.5 4.2 4.2 4.3 4.1 4.2 4.3 4.1 4.2 4.1 Knoop hardness H _K (×10 ⁷ Pa) 696 685 683 677 689 698 699 693 688 696

Table 4 wt% Example twenty one twenty two twenty three twenty four 25 26 27 28 29 30 31 SiO ₂ 6.48 5.29 8.20 8.99 8.20 8.07 6.50 6.94 8.50 5.80 6.70 B ₂ O ₃ 11.33 13.71 10.55 10.30 11.20 11.49 11.20 12.65 10.42 10.80 10.00 La ₂ O ₃ 48.31 49.35 51.28 47.80 44.50 51.28 48.22 43.62 49.25 49.50 50.00 Y ₂ O ₃ 10.77 11.40 10.53 11.90 10.31 11.55 10.77 12.90 8.44 8.80 9.00 TiO ₂ 10.70 5.23 7.01 4.37 9.38 7.55 10.70 7.33 11.70 9.00 9.00 Nb ₂ O ₅ 0.09 4.01 2.21 7.13 5.00 3.03 0.29 5.72 8.00 8.00 WO ₃ 0.80 1.99 1.52 0.62 1.08 0.80 1.94 0.80 1.30 0.80 _ZrO2 4.53 4.79 6.26 6.40 3.99 3.33 4.53 5.62 3.68 5.80 5.50 ZnO 6.99 4.18 1.44 3.11 6.80 2.62 6.99 3.28 7.21 1.00 1.00 BaO 1.00 SrO CaO MgO Gd ₂ O ₃ Ta ₂ O ₅ Sb ₂ O _{3 SnO2} 0.05 WO ₃ /TiO ₂ 0.07 0.38 0.22 0.00 0.07 0.14 0.07 0.26 0.07 0.14 0.09 TiO ₂ +WO ₃ +Nb ₂ O ₅ 11.59 11.23 10.74 11.50 15.00 11.66 11.79 14.99 12.50 18.30 17.80 TiO ₂ /(WO ₃ +Nb ₂ O ₅ ) 12.02 0.87 1.88 0.61 1.67 1.84 9.82 0.96 14.63 0.97 1.02 TiO ₂ /(TiO ₂ +WO ₃ +Nb ₂ O) 0.92 0.47 0.65 0.38 0.63 0.65 0.91 0.49 0.94 0.49 0.51 WO ₃ /La ₂ O ₃ 0.02 0.04 0.03 0.00 0.01 0.02 0.02 0.04 0.02 0.03 0.02 (SiO ₂ +La ₂ O ₃ +TiO)/(B ₂ O ₃ +WO ₃ +Nb ₂ O) 5.36 3.04 4.66 3.51 3.69 4.29 5.32 2.85 6.19 3.20 3.49 La ₂ O ₃ +Y ₂ O ₃ 59.08 60.75 61.81 59.70 54.81 62.83 58.99 56.52 57.69 58.30 59.00 La ₂ O ₃ /Y ₂ O ₃ 4.49 4.33 4.87 4.02 4.32 4.44 4.48 3.38 5.84 5.63 5.56 total 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 Refractive index n _d 1.9396 1.9060 1.9082 1.9018 1.9135 1.9028 1.9405 1.9030 1.9268 1.9502 1.9489 Abbe number v _d 33.98 35.75 35.96 36.36 33.47 35.54 33.94 34.55 33.48 32.37 32.41 Crystallization upper limit temperature (°C) 1195 1200 1195 1200 1190 1190 1195 1195 1200 1240 1230 Weather resistance CR Class 1 Class 2 Class 1 Class 2 Class 1 Class 1 Class 1 Class 1 Class 1 Class 1 Class 1 Abrasion degree F _A 148 147 151 160 145 457 146 147 149 109 112 Acid Stability RA Class 1 Class 1 Class 1 Class 1 Class 1 Class 1 Class 1 Class 1 Class 2 Class 1 Class 1 Refractive index temperature coefficient dn/dt(×10 ^-6 /℃) 4.2 4.6 4.2 4.0 4.1 4.2 4.2 4.5 4.2 4.3 4.2 Knoop hardness H _K (×10 ⁷ Pa) 684 679 688 694 692 689 699 702 683 693 697

[Glass Preforms and Optical Components]

The present invention provides a glass preform. According to an embodiment of the present invention, the glass preform is made of the above-mentioned optical glass. Specifically, the obtained optical glass is cut into a predetermined size, and then a release agent composed of boron nitride powder is uniformly coated on the surface, and then heated, softened, and pressed to form a concave meniscus. Lenses, convex meniscus lenses, bi-convex lenses, bi-concave lenses, plano-convex lenses, plano-concave lenses, etc. Various lenses and prefabricated parts. It should be noted that the features and advantages described above for the optical glass are also applicable to the glass preform, and will not be repeated here.

The present invention proposes an optical element. According to an embodiment of the present invention, the optical element is made of the above-mentioned optical glass or glass prefabricated parts, which can provide various optical elements such as lenses and glass with excellent performance at low cost. For example, various lenses such as a convex meniscus lens, a concave meniscus lens, a biconvex lens, a biconcave lens, a plano-convex lens, and a plano-concave lens with a spherical or aspherical lens surface can be used as the lens. This lens can correct chromatic aberration by combining it with a lens made of high-refractive-index high-dispersion glass, making it suitable as a lens for correcting chromatic aberration. In addition, it is also an effective lens for downsizing the optical system. In addition, due to its high refractive index, it is possible to realize a compact and wide-angle optical system by combining it with the imaging optical system and bending the optical path to the desired direction. Specifically, the above-mentioned glass preforms are annealed, and fine-tuning is performed while reducing the deformation inside the glass, so that the optical properties such as the refractive index reach the required values, and then, each preform is ground and ground to produce a concave meniscus lens Various lenses such as convex meniscus lens, biconvex lens, biconcave lens, plano-convex lens, plano-concave lens, etc., are optical elements, and the surface of the obtained optical element can also be coated with an anti-reflection film. It should be noted that the features and advantages described above for the optical glass and the glass preform are also applicable to the optical element, and will not be repeated here.

[Optical Instruments]

The present invention proposes an optical instrument which, according to an embodiment of the invention, has the optical element described above. Therefore, by using the above-mentioned optical element with excellent performance on the optical instrument, the customer experience of the optical instrument can be improved. Specifically, the optical instrument of the present invention may be a digital camera, a video camera, and the like. It should be noted that the features and advantages described above for the optical element are also applicable to the optical instrument, and will not be repeated here.

Note: 100% of the total amount in the above table is the data after deducting measurement errors, equipment precision and unavoidable impurities.

In the description of this specification, descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific examples", or "some examples" mean that specific features described in connection with the embodiment or example , structure, material or characteristic is included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the described specific features, structures, materials or characteristics may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples and features of different embodiments or examples described in this specification without conflicting with each other.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

none

none

Claims (28)

An optical glass, characterized in that its components are represented by weight percentage, including: SiO ₂ : 5-12%; B ₂ O ₃ : 8-15%; Y ₂ O ₃ : 5-15%; ZrO ₂ : 1 -10%; ZnO: 0.2-10%; La ₂ O ₃ : 40-55%; TiO ₂ +WO ₃ +Nb ₂ O ₅ : 5-20%, of which: TiO ₂ /(TiO ₂ +WO ₃ +Nb ₂ O ₅ ) is 0.38-1.0, the total content of La ₂ O ₃ +Y ₂ O ₃ is 50-70%, La ₂ O ₃ /Y ₂ O ₃

5.90. As described in claim 1, it is optical glass, characterized in that its components are expressed in weight percent, and also contain: RO: 0-10%; and/or high-temperature molten glass surface tension improving agent: 0-0.5%, said RO is one or more of BaO, SrO, CaO, and MgO, and the high-temperature molten glass surface tension improver is one or more of Sb ₂ O ₃ , SnO, SnO ₂ , and CeO ₂ components. An optical glass, characterized in that its components contain SiO ₂ , B ₂ O ₃ , Y ₂ O ₃ , ZrO ₂ , ZnO, La ₂ O ₃ , and its components are expressed in weight percent, TiO ₂ +WO ₃ + Nb ₂ O ₅ : 5-20%, wherein: TiO ₂ /(TiO ₂ +WO ₃ +Nb ₂ O ₅ ) is 0.38-1.0, the refractive index n _d of the optical glass is above 1.90, and the Abbe number v _d 30 or more, weather resistance class 2 or above, the total content of La ₂ O ₃ +Y ₂ O ₃ is 50-70%, La ₂ O ₃ /Y ₂ O ₃

5.90. The optical glass as claimed in item 3 is characterized in that its components are expressed in weight percent, including: SiO ₂ : 5-12%; and B ₂ O ₃ : 8-15%; and Y ₂ O ₃ : 5% -15%; and ZrO ₂ : 1-10%; and ZnO: 0.2-10%; and La ₂ O ₃ : 40-55%; and RO: 0-10%; -0.5%; the RO is one or more of BaO, SrO, CaO, and MgO, and the high-temperature molten glass surface tension improving agent is one or more of Sb ₂ O ₃ , SnO, SnO ₂ , and CeO ₂ components. The optical glass as claimed in item 3 is characterized in that its components are represented by weight percentage, including: SiO ₂ : 5-12%; or B ₂ O ₃ : 8-15%; or Y ₂ O ₃ : 5% -15%; or ZrO ₂ : 1-10%; or ZnO: 0.2-10%; or La ₂ O ₃ : 40-55%; or RO: 0-10%; or high temperature glass liquid surface tension improver: 0 -0.5%; the RO is one or more of BaO, SrO, CaO, and MgO, and the high-temperature molten glass surface tension improving agent is one or more of Sb ₂ O ₃ , SnO, SnO ₂ , and CeO ₂ components. An optical glass, characterized in that its components are represented by weight percentage, consisting of SiO ₂ : 5-12%; B ₂ O ₃ : 8-15%; Y ₂ O ₃ : 5-15%; ZrO ₂ : 1-15% 10%; ZnO: 0.2-10%; La ₂ O ₃ : 40-55%; RO: 0-10%; the total content of La ₂ O ₃ +Y ₂ O ₃ is 50-70%, La ₂ O ₃ /Y ₂ O ₃

5.90; high-temperature molten glass surface tension improver: 0-0.5% composition, TiO ₂ +WO ₃ +Nb ₂ O ₅ : 5-20%, where: TiO ₂ /(TiO ₂ +WO ₃ +Nb ₂ O ₅ ) is 0.38-1.0, the RO is one or more of BaO, SrO, CaO, and MgO, and the high-temperature molten glass surface tension improver is one or more of Sb ₂ O ₃ , SnO, SnO ₂ , and CeO ₂ components. The optical glass as described in any one of claim items 1-6 is characterized in that its components are expressed in weight percent, wherein: TiO ₂ +WO ₃ +Nb ₂ O ₅ : 5-14.8%; and TiO ₂ /(TiO ₂ +WO ₃ +Nb ₂ O ₅ ) is 0.4-1.0; and WO ₃ /TiO ₂ is 1.0 or less; and TiO ₂ /(WO ₃ +Nb ₂ O ₅ ) is 0.6-15; and WO ₃ / La ₂ O ₃ is less than 0.05; and (SiO ₂ +La ₂ O ₃ +TiO ₂ )/(B ₂ O ₃ +WO ₃ +Nb ₂ O ₅ ) is 2.85-7.25. The optical glass as described in any one of claim items 1-6 is characterized in that its components are expressed in weight percent, wherein: TiO ₂ +WO ₃ +Nb ₂ O ₅ : 5-14.8%; or TiO ₂ /(TiO ₂ +WO ₃ +Nb ₂ O ₅ ) is 0.4-1.0; or WO ₃ /TiO ₂ is less than 1.0; or TiO ₂ /(WO ₃ +Nb ₂ O ₅ ) is 0.6-15; or WO ₃ / La ₂ O ₃ is less than 0.05; or (SiO ₂ +La ₂ O ₃ +TiO ₂ )/(B ₂ O ₃ +WO ₃ +Nb ₂ O ₅ ) is 2.85-7.25. The optical glass as described in any one of claim items 1-6 is characterized in that its components are expressed in weight percent, wherein: SiO ₂ : 5-10%; and B ₂ O ₃ : 10-15%; and Y ₂ O ₃ : 7-14%; and ZrO ₂ : 2-8%; and ZnO: 0.5-8%; and La ₂ O ₃ : 40-52%; and RO: 0-5%; Liquid surface tension improving agent: 0-0.3%; the RO is one or more of BaO, SrO, CaO, MgO, and the high-temperature glass liquid surface tension improving agent is Sb ₂ O ₃ , SnO, SnO ₂ , CeO ₂ components one or more of. The optical glass as described in any one of claim items 1-6 is characterized in that its components are expressed in weight percent, wherein: SiO ₂ : 5-10%; or B ₂ O ₃ : 10-15%; Or Y ₂ O ₃ : 7-14%; or ZrO ₂ : 2-8%; or ZnO: 0.5-8%; or La ₂ O ₃ : 40-52%; or RO: 0-5%; or high temperature glass Liquid surface tension improving agent: 0-0.3%; the RO is one or more of BaO, SrO, CaO, MgO, and the high-temperature glass liquid surface tension improving agent is Sb ₂ O ₃ , SnO, SnO ₂ , CeO ₂ components one or more of. The optical glass according to any one of claims 1-6, characterized in that its components are expressed in weight percent, wherein: TiO ₂ +WO ₃ +Nb ₂ O ₅ : 5-12%; and TiO ₂ /(TiO ₂ +WO ₃ +Nb ₂ O ₅ ) is 0.47-1.0; and WO ₃ /TiO ₂ is 0.4 or less; and TiO ₂ /(WO ₃ +Nb ₂ O ₅ ) is 0.6-14; and WO ₃ / La ₂ O ₃ is 0.03 or less; and (SiO ₂ +La ₂ O ₃ +TiO ₂ )/(B ₂ O ₃ +WO ₃ +Nb ₂ O ₅ ) is 2.85-7.0. The optical glass as described in any one of claim items 1-6 is characterized in that its components are expressed in weight percent, wherein: TiO ₂ +WO ₃ +Nb ₂ O ₅ : 5-12%; or TiO ₂ /(TiO ₂ +WO ₃ +Nb ₂ O ₅ ) is 0.47-1.0; or WO ₃ /TiO ₂ is less than 0.4; or TiO ₂ /(WO ₃ +Nb ₂ O ₅ ) is 0.6-14; or WO ₃ / La ₂ O ₃ is 0.03 or less; or (SiO ₂ +La ₂ O ₃ +TiO ₂ )/(B ₂ O ₃ +WO ₃ +Nb ₂ O ₅ ) is 2.85-7.0. The optical glass as described in any one of claim items 1-6 is characterized in that its components are expressed in weight percent, wherein: ZnO: 0.5-4.5%; and La ₂ O ₃ : 44-52%; and RO: 0-3%, said RO is one or more of BaO, SrO, CaO, MgO. The optical glass as described in any one of claim items 1-6 is characterized in that its components are expressed in weight percentage, wherein: ZnO: 0.5-4.5%; or La ₂ O ₃ : 44-52%; or RO: 0-3%, said RO is one or more of BaO, SrO, CaO, MgO. Optical glass as described in any one of claims 1-6, characterized in that its components are expressed in weight percent, wherein: WO ₃ : 0-2.4%; and TiO ₂ : 6-15%; and Nb ₂ O ₅ : 0-8%; and BaO: 0-5%; SrO: 0-5%; and CaO: 0-5%; and MgO: 0-5%. The optical glass as described in any one of claim items 1-6 is characterized in that its components are expressed in weight percent, wherein: WO ₃ : 0-2.4%; or TiO ₂ : 6-15%; or Nb ₂ O ₅ : 0-8%; or BaO: 0-5%; SrO: 0-5%; or CaO: 0-5%; or MgO: 0-5%. Optical glass as described in any one of claims 1-6, characterized in that its components are expressed in weight percent, wherein: WO ₃ : 0.1-2.4%; and TiO ₂ : 6-12%; and Nb ₂ O ₅ : 0-7%; and BaO: 0-3%; SrO: 0-3%; and CaO: 0-3%; and MgO: 0-3%. The optical glass as described in any one of claim items 1-6 is characterized in that its components are expressed in weight percent, wherein: WO ₃ : 0.1-2.4%; or TiO ₂ : 6-12%; or Nb ₂ O ₅ : 0-7%; or BaO: 0-3%; SrO: 0-3%; or CaO: 0-3%; or MgO: 0-3%. The optical glass as described in any one of claim items 1-6 is characterized in that its components are expressed in weight percent, wherein: the total content of La ₂ O ₃ +Y ₂ O ₃ is 54-67%, preferably 57-65%; and La ₂ O ₃ /Y ₂ O ₃

5.10, more preferably La ₂ O ₃ /Y ₂ O ₃

4.70. The optical glass as described in any one of claim items 1-6 is characterized in that its components are expressed in weight percent, wherein: the total content of La ₂ O ₃ +Y ₂ O ₃ is 54-67%, preferably 57-65%; or La ₂ O ₃ /Y ₂ O ₃

5.10, more preferably La ₂ O ₃ /Y ₂ O ₃

4.70. The optical glass according to any one of claims 1-6, characterized in that its components do not contain Gd ₂ O ₃ ; and do not contain Yb ₂ O ₃ ; and do not contain Ta ₂ O ₅ ; and do not contain Contains RO. The optical glass according to any one of claims 1-6, characterized in that its components do not contain Gd ₂ O ₃ ; or do not contain Yb ₂ O ₃ ; or do not contain Ta ₂ O ₅ ; or do not contain Contains RO. The optical glass as described in any one of claims 1-6, wherein the optical glass has a refractive index n _d above 1.90, preferably 1.90-1.95, more preferably 1.90-1.94; Abbe number v _d It is more than 30, preferably 30-40. The optical glass according to any one of claims 1-6, wherein the weather resistance of the optical glass is more than Class 2, preferably Class 1; and the crystallization upper limit temperature of the optical glass is 1250 °C or lower, preferably lower than 1200 °C; and the temperature coefficient of the refractive index is lower than 5.5×10 ^-6 /°C, preferably lower than 5.0×10 ^-6 /°C; and the degree of abrasion is 90-200, preferably 90-160; and The acid resistance stability is above class 2, preferably class 1; and the Knoop hardness H _K is 650×10 ⁷ -750×10 ⁷ Pa, preferably 660×10 ⁷ -720×10 ⁷ Pa. The optical glass according to any one of claim items 1-6, characterized in that, the weather resistance of the optical glass is above Class 2, preferably Class 1; or the crystallization upper limit temperature of the optical glass is 1250 °C or lower, preferably lower than 1200 °C; or the temperature coefficient of the refractive index is lower than 5.5×10 ^-6 /°C, preferably lower than 5.0×10 ^-6 /°C; or the degree of abrasion is 90-200, preferably 90-160; or The acid resistance stability is above class 2, preferably class 1; or the Knoop hardness H _K is 650×10 ⁷ -750×10 ⁷ Pa, preferably 660×10 ⁷ -720×10 ⁷ Pa. A glass preform, which is made of the optical glass described in any one of claims 1-6. An optical element, which is made of the optical glass described in any one of claims 1-6 or the glass preform described in claim 24. An optical instrument made of the optical glass described in any one of claims 1-6 or the optical element described in claim 26.