CN109081578B

CN109081578B - Optical glass, preform thereof, optical element and optical instrument

Info

Publication number: CN109081578B
Application number: CN201811138264.8A
Authority: CN
Inventors: 孙伟
Original assignee: Chengdu Guangming Optoelectronics Co Ltd
Current assignee: Chengdu Guangming Optoelectronics Co Ltd
Priority date: 2018-09-28
Filing date: 2018-09-28
Publication date: 2020-02-07
Anticipated expiration: 2038-09-28
Also published as: TW202012330A; CN109081578A; TWI729504B

Abstract

The invention provides a composition which comprises SiO in percentage by weight₂：0‑10％，B₂O₃：5‑25％，ZrO₂：0‑15％，ZnO：10‑25％，TiO₂+Nb₂O₅+WO₃：2‑30％，Ln₂O₃: 30-55% of optical glass, Ln₂O₃Is La₂O₃、Gd₂O₃、Y₂O₃And Yb₂O₃In total, wherein B₂O₃/Ln₂O₃Is 0.3-0.8, Y₂O₃/B₂O₃Is 0.15-2. The optical glass has a refractive index (nd) of 1.84-1.87 and an Abbe number (vd) of 38-41, and is excellent in devitrification resistance and bubble degree and good in chemical stability.

Description

Optical glass, preform thereof, optical element and optical instrument

Technical Field

The invention belongs to the field of optical glass, and particularly relates to optical glass, a prefabricated member, an optical element and an optical instrument which are manufactured by the optical glass.

Background

The optical glass can be used for manufacturing lenses, prisms, mirrors and the like in optical instruments, and components made of the optical glass are key elements in the optical instruments. Optical glass having a refractive index (nd) of 1.84 to 1.87 and an Abbe number (vd) of 38 to 41 is widely used for manufacturing lenses of cameras, telescopes, microscopes and other precision optical instruments because of its good transmission property and high refractive index. In recent years, there has been a trend toward downsizing and weight reduction of optical instruments by reducing the number of optical elements using aspherical lenses, and the market demand has been increasing.

However, the production of aspherical lenses by conventional methods such as hot press molding, regrinding and polishing, and molten glass remanufacturing is costly and complicated in working steps. Precision press molding is a method for preparing optical elements from optical glass materials with simpler operation and lower cost. But the method for manufacturing the aspheric lens puts higher requirements on the performance of the glass material. It is required to be easily subjected to precision press molding, to have high devitrification resistance, to have a low melting point, to have excellent bubble content, and the like. If the optical element is used in outdoor long-term use of photographic equipment such as digital cameras, video cameras and the like, the optical glass material is required to have better chemical stability so as to resist corrosion of water, acid and the like in outdoor environment and ensure the service quality and the service life of the lens. In addition, for optical instruments that need to operate at a particular temperature, the glass material is also required to have a good coefficient of thermal expansion to reduce the extent to which the glass expands and contracts under temperature changes.

Patents CN104803600A, CN104098267A, CN105819682A, etc. provide optical glasses having the same or similar refractive index (nd) and abbe number (vd) as the present invention, respectively, but still cannot satisfy the other requirements mentioned above.

Disclosure of Invention

In view of the foregoing disadvantages of the prior art, it is an object of the present invention to provide an optical glass having a refractive index (nd) of 1.84 to 1.87 and an Abbe number (vd) of 38 to 41. The optical glass is easy to perform precision compression molding, and has high devitrification resistance, excellent bubble degree, good chemical stability and low cost.

The invention also provides a prefabricated member, an optical element and an optical instrument which are made of the optical glass.

The technical scheme adopted by the invention for realizing the purpose is as follows:

an optical glass comprising, in weight%: SiO 2₂：0-10％，B₂O₃：5-25％，ZrO₂：0-15％，ZnO：10-25％，TiO₂+Nb₂O₅+WO₃：2-30％，Ln₂O₃: 30-55%, the Ln₂O₃Is La₂O₃、Gd₂O₃、Y₂O₃And Yb₂O₃In total, wherein B₂O₃/Ln₂O₃Is 0.3-0.8, Y₂O₃/B₂O₃Is 0.15-2.

Further, the optical glass further contains, in weight%: 0-10% of RO, 0-10% of Rn₂O, 0-1% of clarifying agent, wherein RO is one or more of MgO, CaO, SrO or BaO, and Rn₂O is Li₂O、Na₂O、K₂One or more of O, and Sb as the clarifying agent₂O₃、SnO₂、CeO₂One or more of (a).

Optical glass consisting of 0-10% by weight of SiO₂5-25% of B₂O₃0-15% of ZrO₂10-25% of ZnO and 2-30% of TiO₂+Nb₂O₅+WO₃30-55% Ln₂O₃0-10% of RO, 0-10% of Rn₂O, 0-1% of clarifying agent, the Ln₂O₃Is La₂O₃、Gd₂O₃、Y₂O₃And Yb₂O₃RO is one or more of MgO, CaO, SrO and BaO, and Rn₂O is Li₂O、Na₂O、K₂One or more of O, and Sb as the clarifying agent₂O₃、SnO₂、CeO₂Wherein B is₂O₃/Ln₂O₃Is 0.3-0.8, Y₂O₃/B₂O₃Is 0.15-2.

Further, in the optical glass, the content of each component satisfies one or more of the following 4 cases:

1)SiO₂/(SiO₂+B₂O₃) 0 to 0.25;

2)Y₂O₃/Ln₂O₃0.08-0.45;

3)Y₂O₃/Gd₂O₃0.3 to 3;

4)Y₂O₃/(SiO₂+B₂O₃) Is 0.16-0.8.

Further, the optical glass described above, wherein: SiO 2₂: 1-8%, and/or B₂O₃: 10-23%, and/or ZrO₂: 1-10%, and/or ZnO: 10-20%, and/or TiO₂+Nb₂O₅+WO₃: 4-22%, and/or Ln₂O₃: 35-52%, and/or RO: 0-5%, and/or R₂O: 0-5% and/or clarifying agent 0-0.5%.

Further, in the aforementioned optical glass, the content of each component satisfies one or more of the following 6 cases:

1)SiO₂/(SiO₂+B₂O₃) 0.05-0.23;

2)Y₂O₃/Ln₂O₃0.1-0.4;

3)Y₂O₃/Gd₂O₃0.5-2.5;

4)Y₂O₃/(SiO₂+B₂O₃) 0.2 to 0.7;

5)B₂O₃/Ln₂O₃0.3-0.6;

6)Y₂O₃/B₂O₃is 0.2-1.5.

Further, the optical glass described above, wherein: SiO 2₂: 1-4%, and/or B₂O₃: 15-20%, and/or ZrO₂: 2-6%, and/or ZnO: 13-17%, and/or TiO₂+Nb₂O₅+WO₃: 10-18%, and/or Ln₂O₃：40-50％。

1)SiO₂/(SiO₂+B₂O₃) 0.08-0.2;

2)Y₂O₃/Ln₂O₃0.1-0.3;

3)Y₂O₃/Gd₂O₃greater than 1 but less than or equal to 2;

4)Y₂O₃/(SiO₂+B₂O₃) 0.3-0.6;

5)B₂O₃/Ln₂O₃0.3-0.5;

6)Y₂O₃/B₂O₃is 0.3-1.

Further, the optical glass described above, wherein: nb₂O₅: 1-15%, and/or WO₃: 1-15%, and/or TiO₂: 0-10%, and/or La₂O₃: 20-45%, and/or Gd₂O₃: 0-15%, and/or Y₂O₃：1-15％And/or Yb₂O₃：0-5％。

Further, the optical glass described above, wherein: nb₂O₅: 2-10%, and/or WO₃: 2-12%, and/or TiO₂: 0-5%, and/or La₂O₃: 25-40%, and/or Gd₂O₃: 1-10%, and/or Y₂O₃：3-15％。

Further, the optical glass described above, wherein: nb₂O₅: 4-8%, and/or WO₃: 6-10%, and/or La₂O₃: 30-35%, and/or Gd₂O₃: 3-7%, and/or Y₂O₃: 6-10% and/or no TiO₂。

Further, the aforementioned optical glass has a refractive index (nd) of 1.84 to 1.87, preferably 1.85 to 1.86; the Abbe number (vd) is 38.0 to 41.0, preferably 38.5 to 40.0.

Further, the above optical glass has water resistance stability by powder method (D)_W) Is 2 or more, preferably 1, and is resistant to acid by powder process (D)_A) Is 3 or more, preferably 2; the bubble degree is A grade or above, preferably A grade₀Stage A or₀The above.

Further, the optical glass has a thermal expansion coefficient (α)_-30℃-70℃)≤75×10^-7/K, preferably α_-30℃-70℃≤70×10^-7K; its transition temperature (T)_g) Is 640 ℃ or lower, preferably 630 ℃ or lower, more preferably 625 ℃ or lower; the upper limit temperature of crystallization of the optical glass is 1250 ℃ or less, preferably 1200 ℃ or less, and more preferably 1180 ℃ or less.

The glass preform is made of the optical glass.

The optical element is made of the optical glass or the glass prefabricated member.

The optical instrument is made of the optical element.

The high-refraction low-dispersion glass material has excellent devitrification resistance, is easy to perform precision compression molding, controls the content of high-price raw materials such as rare earth oxide and the like, has low cost, and is suitable for being popularized and applied to precision compression molding processes. Meanwhile, the chemical stability and the bubble degree of the glass are improved through the reasonable component proportion, and the yield of the product is improved. Some preferred technical schemes further optimize the component proportion so as to reduce the thermal expansion coefficient of the glass, optimize the devitrification resistance of the glass and strengthen the chemical stability. Provides a high cost performance glass material for manufacturing optical elements and optical instruments with better quality and longer service life.

Detailed Description

Optical glass

The composition of the optical glass of the present invention is described in detail below, and when not otherwise specified, the content and the total content of the respective glass components each mean a weight content, expressed in% by weight, which is a percentage of the weight of a certain component or the sum of the weights of several components based on the total weight of the optical glass; the ratio of the glass components or the sum of the components is the ratio of the corresponding weight contents or the ratio of the sum of the weight contents.

The optical glass of the present invention has optical properties required for producing a lens material for precision instruments, a refractive index (nd) of 1.84 to 1.87 and an Abbe number (vd) of 38 to 41, is easy to precision press mold, and is excellent in chemical stability and bubble degree. The optical glass contains the following components in percentage by weight: SiO 2₂：0-10％，B₂O₃：5-25％，ZrO₂：0-15％，ZnO：10-25％，TiO₂+Nb₂O₅+WO₃：2-30％，Ln₂O₃: 30-55%, the Ln₂O₃Is La₂O₃、Gd₂O₃、Y₂O₃And Yb₂O₃And wherein B is₂O₃/Ln₂O₃Is 0.3-0.8, Y₂O₃/B₂O₃Is 0.15-2.

Wherein, B₂O₃Is a glass network forming component and has the functions of improving the meltability and the devitrification resistance of the glass. In order to achieve the above effects, the present invention providesMore than 5% of B₂O₃Preferably, more than 10% of B is introduced₂O₃More preferably, 15% or more of B is introduced₂O₃(ii) a However, when the amount of incorporation exceeds 25%, glass forming stability is lowered and refractive index is lowered, so that B of the present invention₂O₃The upper limit of the content of (b) is 25%, preferably 23%, more preferably 20%.

SiO₂Is an optional component in the present invention which also constitutes a glass former. SiO 2₂The three-dimensional network of silicon-oxygen tetrahedrons is formed in the glass, and is very compact and firm. The network is added into the glass to reinforce the loose boron-oxygen triangular network, so that the boron-oxygen triangular network becomes compact, and the high-temperature viscosity of the glass is improved. Furthermore, SiO₂Higher contents are more advantageous in reducing the thermal expansion coefficient of the glass. SiO in the optical glass of the present invention₂The lower limit of the content is 0%, preferably 1%; if SiO₂Since the content of (b) is too large, the glass transition temperature is increased, the glass meltability is lowered, and the process difficulty is increased, the upper limit of the content is 10%, preferably 8%, and more preferably 4%.

SiO₂And B₂O₃Are all glass network forming components, and through the research of the inventor, SiO is found under the formula of the invention₂/(SiO₂+B₂O₃) The devitrification resistance and the thermal expansion coefficient of the glass are affected. SiO 2₂/(SiO₂+B₂O₃) The larger the value of (A), the lower the thermal expansion coefficient of the glass, which is advantageous in reducing the sensitivity of the glass to temperature, but at the same time, results in deterioration of the devitrification resistance of the glass. It has been found that in the formulation of the present invention, when SiO is used₂/(SiO₂+B₂O₃) When the value of (A) is in the range of 0 to 0.25, the thermal expansion coefficient of the glass can be made lower than 75X 10^-7A ratio of 0.05 to 0.23, preferably 0.08 to 0.2.

ZrO₂As an optional component in the present invention, a high refractive index, low dispersion oxide is added to the glassTo raise the refractive index of the glass and to adjust the dispersion. At the same time, an appropriate amount of ZrO₂When the glass is added, the devitrification resistance and the chemical stability of the glass can be improved. However, in the optical glass of the present invention, if the content is more than 15%, the glass becomes difficult to melt, the melting temperature increases, and inclusions in the glass and the transmittance thereof tend to decrease. Therefore, the content thereof is set to 0 to 15%, preferably 1 to 10%, and more preferably 2 to 6%.

ZnO can adjust the refractive index and dispersion of glass, improve the devitrification resistance of the glass, reduce the transition temperature of the glass and improve the chemical stability of the glass. ZnO can also reduce the high-temperature viscosity of the glass, so that the glass can be smelted at a lower temperature, and the transmittance of the glass can be improved. However, if the amount of ZnO added is too large, the devitrification resistance of the glass is rather lowered, and the high-temperature viscosity is small, which makes molding difficult. Therefore, in the glass system of the present invention, the lower limit of the content of ZnO is set to 10%, and the preferable lower limit is 13%; the upper limit of the content of ZnO is 25%, preferably 20%, and more preferably 17%.

TiO₂As optional components, the refractive index of the glass can be improved, and TiO is added in proper amount₂The glass of the invention can increase the anti-crystallization stability of the glass and can replace Nb to a certain extent₂O₅And WO₃. However, too high a content will result in a decrease in the glass transmittance. In the optical glass of the present invention, TiO₂Is 0 to 10%, preferably 0 to 5%, more preferably 0%.

Nb₂O₅Is a component capable of improving the chemical stability and refractive index of the glass. When Nb₂O₅When the content of (A) is less than 1%, the optical constant cannot meet the design requirement; when the content exceeds 15%, the devitrification resistance of the glass is lowered, and therefore, Nb₂O₅The content of (B) is limited to 1 to 15%, preferably 2 to 10%, more preferably 4 to 8%.

WO₃The main function of the glass is to maintain optical constants and improve the devitrification performance of the glass, but the content of the glass is too high, so that the transmittance of the glass is reduced, the degree of coloration is increased, andthe crystallization performance is deteriorated. Therefore, WO₃Is preferably 1 to 15%, more preferably 2 to 12%, and still more preferably 6 to 10%.

Due to TiO₂、Nb₂O₅、WO₃All have the effect of increasing the refractive index but also the dispersion, and therefore, from the requirement that the optical glass of the present invention should have high refraction, low dispersion and high transmittance, TiO is used₂+Nb₂O₅+WO₃The upper limit of (2) is 30%, a preferable upper limit is 22%, and a more preferable upper limit is 18%. However, when TiO₂+Nb₂O₅+WO₃Since too low a content will result in lowering the thermal stability and compressibility of the glass, the lower limit is set to 2%, the preferred lower limit is set to 4%, and the more preferred lower limit is set to 10%.

Adding rare earth oxide Ln₂O₃(La₂O₃、Gd₂O₃、Y₂O₃And Yb₂O₃) It contributes to increase of the refractive index of the glass, and when the total content thereof is less than 30%, the desired optical constants cannot be obtained, but when the total content thereof exceeds 55%, the chemical stability, resistance to devitrification of the glass will be reduced, and the raw material cost of the glass will be increased. Thus La₂O₃、Gd₂O₃、Y₂O₃And Yb₂O₃Total content Ln of₂O₃The content is set to 30 to 55%, preferably 35 to 52%, and more preferably 40 to 50%.

Rare earth oxide Ln₂O₃Dispersed in the glass network, mainly for improving the refractive index, but the inventors of the present application found in the research that the glass network component B₂O₃And Ln₂O₃The ratio of (A) has an important influence on the chemical stability of the glass. When B is present₂O₃/Ln₂O₃Below 0.3, the chemical stability, especially the acid resistance, is not satisfactory, while when B is used₂O₃/Ln₂O₃Above 0.8, the refractive index is lowered, and therefore the present invention sets the range to 0.3 to 0.8, preferably 0.3 to 0.6, more preferably 0.3 to 0.5.

La in rare earth oxide₂O₃Is a component which can improve the optical characteristics of the glass, but when the content thereof exceeds 45%, both devitrification resistance and melting property of the glass are deteriorated. Therefore, La of the present invention is preferable₂O₃The content of (B) is 20 to 45%, more preferably 25 to 40%, still more preferably 30 to 35%.

Gd₂O₃As an optional component, the refractive index of the glass can be increased without significantly increasing the dispersion of the glass, by introducing Gd in the present invention₂O₃The stability of the formed glass can be improved, the chemical stability of the glass is obviously enhanced, and the excessive rise of the dispersion is controlled while the refractive index is maintained; however, if the content exceeds 15%, the devitrification resistance of the glass is lowered and the density of the glass tends to be increased. Thus, Gd of the present invention₂O₃The content of (B) is 0 to 15%, preferably in the range of 1 to 10%, more preferably in the range of 3 to 7%.

Y₂O₃The glass composition is a component which can improve the melting property and devitrification resistance of the glass while maintaining a high refractive index and a high Abbe number and suppressing the cost increase of the glass material, and can lower the glass crystallization upper limit temperature and the specific gravity, but when the content thereof exceeds 15% in the formulation of the present invention, the chemical stability and devitrification resistance of the glass are lowered. Therefore, Y is preferred₂O₃The content is in the range of 1 to 15%, more preferably in the range of 3 to 15%, still more preferably in the range of 6 to 10%.

Y₂O₃Can improve the refractive index of glass with other rare earth oxides and has higher cost than Gd₂O₃Low, and can reduce the density of the glass, which is beneficial to lightening, therefore, the component is introduced into more prior art. However, in the formulation system of the present invention, Y₂O₃Not only independently have the aforementioned effect on the glass, but also cooperate with other components to adjust various properties of the glass. Which comprises the following steps:

when the optical glasses of the present invention each contain Y₂O₃And La₂O₃In this case, the devitrification resistance of the glass can be more effectively improved, and the glass can be made of a glass materialWhen the glass element is made, the precision compression molding is easier to be carried out, and the difficulty of manufacturing the glass element is reduced;

when Y is₂O₃/B₂O₃When the content is too low, gas is not easy to discharge in the smelting process, so that the bubble degree of the glass is poor, and Y is₂O₃/B₂O₃The lower limit of the value of (b) is 0.15, preferably 0.2, more preferably 0.3; but Y is₂O₃/B₂O₃Too high, the glass tends to have a reduced chemical stability, so that Y₂O₃/B₂O₃The upper limit 2 of the value of (b) is preferably 1.8, more preferably 1.5, still more preferably 1.3, and yet more preferably 1;

Gd₂O₃and Y₂O₃Can be replaced to some extent in increasing the refractive index, Y₂O₃/Gd₂O₃The higher the value of (A), the more advantageous is the reduction in raw material cost, and furthermore, the inventors have found that when Y is used₂O₃/Gd₂O₃When the amount is less than 0.3 or more than 3, the devitrification resistance of the glass is deteriorated, and therefore, Y is added₂O₃/Gd₂O₃Is set to 0.3 to 3, preferably 0.5 to 2.5, more preferably greater than 1 but equal to or less than 2;

Y₂O₃ratio Y in all rare earth oxides₂O₃/Ln₂O₃Has obvious regulation effect on the devitrification resistance of glass, when Y is₂O₃/Ln₂O₃When the value of (A) is 0.08 to 0.45, the resistance to devitrification is excellent, and more preferably 0.1 to 0.4, and still more preferably 0.1 to 0.3.

Furthermore, Y₂O₃/(SiO₂+B₂O₃) The chemical stability of the glass is influenced, when the value is 0.16-0.8, the chemical stability of the glass is excellent, the corrosion resistance is strong, the service life of an optical instrument can be effectively prolonged, and Y is more preferable₂O₃/(SiO₂+B₂O₃) The value of (B) is 0.2 to 0.7, more preferably 0.3 to 0.6.

Yb₂O₃Is of high refractive index and low colorWhen the content of the dispersion component exceeds 5%, the stability and devitrification resistance of the glass are lowered, and thus Yb₂O₃The content range is limited to 0-5%. At the same time, since Yb₂O₃Relative to Gd₂O₃、Y₂O₃It is expensive and has little effect of improving the melting property of the glass, and therefore, it is preferable not to introduce it.

RO belongs to the alkaline earth metal oxides and is one or more of CaO, MgO, SrO and BaO, which are optional components in the present invention. The addition of an appropriate amount of alkaline earth metal oxide to the glass can raise the Young's modulus of the glass, lower the high temperature viscosity of the glass, and at the same time balance the glass components, improving the melting properties of the glass. However, when the total content of RO is more than 10%, the excessive alkaline earth metal oxide may lower the devitrification resistance of the glass. Therefore, the present invention sets the value of RO to 0 to 10%, preferably 0 to 5%.

Rn₂O is an alkali metal oxide, being Li₂O、Na₂O、K₂One or more of O, are optional components in the present invention. In the glass system of the present invention, the desired high temperature viscosity can be obtained by an appropriate amount of alkali metal oxide, and at the same time, when an appropriate amount of alkali metal oxide is mixed with B₂O₃In coexistence, B can be increased₂O₃The compactness of the network can obtain better light transmittance. Too little alkali metal oxide cannot adjust the viscosity of the glass to a suitable range, while too much alkali metal oxide abruptly deteriorates the devitrification resistance of the glass. In the invention, Rn₂The value of O is set to 0 to 10%, preferably 0 to 5%.

In addition, the glasses of the present invention may incorporate 0-1%, preferably 0-0.5%, of a fining agent, optionally Sb₂O₃Or/and CeO₂Or/and SnO₂。

Other components not mentioned above, such as P, can be added in small amounts as required within the range not impairing the characteristics of the glass of the present invention₂O₅、Bi₂O₃、TeO₂、Ga₂O₃、GeO₂、Ta₂O₅、Lu₂O₃And the like. However, since the glass is colored and absorbs at a specific wavelength in the visible light region even when a small amount of a transition metal component such as V, Cr, Mn, Fe, Co, Ni, Cu, Ag, and Mo is contained alone or in combination, thereby reducing the property of the present invention to improve the effect of the visible light transmittance, it is preferable that the optical glass, which requires transmittance at a wavelength in the visible light region, is not substantially contained.

In recent years, compounds of Pb, As, Th, Cd, Tl, Os, Be, and Se tend to Be used As harmful chemical substances under control, and measures for protecting the environment are required not only in the glass production process but also in the processing process and disposal after commercialization. Therefore, when importance is attached to the influence on the environment, it is preferable that these components are not substantially contained except for inevitable mixing. Thereby, the optical glass becomes practically free from substances contaminating the environment. Therefore, the optical glass of the present invention can be manufactured, processed, and discarded without taking special measures for environmental countermeasures.

Properties of optical glass

[ optical Properties ]

The refractive index (nd) was measured according to GB/T7962.1-2010 method.

The Abbe number (vd) was measured according to GB/T7962.1-2010 method.

[ thermal Properties ]

Coefficient of thermal expansion (α)_-30℃-70℃) Tested according to the method GB/T7962.16-2010, Unit 10^-7/K。

Transition temperature (T)_g) Measured according to the method specified in GB/T7962.16-2010, the unit: DEG C.

The crystallization upper limit temperature test method comprises the following steps: measuring the crystallization performance of the glass by adopting a gradient temperature furnace method, manufacturing the glass into a sample of 180 x 10mm, polishing the side surface, putting the sample into a furnace with a temperature gradient (5 ℃/cm), heating to 1400 ℃, keeping the temperature for 4 hours, taking out the sample, naturally cooling to room temperature, observing the crystallization condition of the glass under a microscope, wherein the highest temperature corresponding to the occurrence of crystals of the glass is the crystallization upper limit temperature of the glass. The lower the crystallization upper limit temperature of the glass is, the stronger the stability of the glass at high temperature is, and the better the production process performance is.

[ chemical stability ]

Stability against Water action (D)_W) Testing according to GB/T17129.

Stability against acid action (D)_A) Testing according to GB/T17129.

[ degree of bubbling ]

The bubble degree was measured according to the method GB/T7962.8-2010.

The glass according to the invention has, as tested, the following properties of a refractive index (nd) of 1.84 to 1.87, preferably 1.85 to 1.86, an Abbe number (vd) of 38 to 41, preferably 38.5 to 40, a coefficient of thermal expansion (α)_-30℃-70℃)≤75×10^-7K, preferably ≤ 70 × 10^-7K; stability against Water action (D)_W) Up to 2 or more, preferably 1; the stability of acid resistance is more than 3 types, preferably more than 2 types; the upper limit temperature of crystallization is 1250 ℃ or lower, preferably 1200 ℃ or lower, and more preferably 1180 ℃ or lower; the bubble degree reaches above A grade, preferably A₀More preferably A or more₀₀A stage; glass transition temperature (T)_g) Is 640 ℃ or lower, preferably 630 ℃ or lower, and more preferably 625 ℃ or lower.

Examples of optical glasses

In order to further clarify the explanation and explanation of the technical solution of the present invention, the following non-limiting examples are provided.

Examples 1 to 48 of tables 1 to 6 and comparative examples 1 to 5 of table 7 were obtained by weighing and mixing ordinary raw materials (such as oxides, hydroxides, carbonates, nitrates, etc.) for optical glass in the respective contents corresponding to the respective examples or comparative examples, placing the mixed raw materials in a platinum crucible, melting at 1200-1500 deg.c for 2 to 6 hours, and after fining, stirring and homogenizing, obtaining a homogeneous molten glass, casting this molten glass in a mold and annealing.

TABLE 1

TABLE 2

TABLE 3

TABLE 4

TABLE 5

TABLE 6

TABLE 7

The optical glass of the above embodiment of the present invention is easy to be precision press molded, has good devitrification resistance, and Ln₂O₃The content of (A) is less than 55%, and the cost is low. Water stability (D)_W) Is more than 2 types, and in a preferred technical scheme, D_WThe acid resistance is more than 3, in the preferred technical scheme, more than 2, the chemical stability is good, the bubble degree is more than A grade, in the preferred technical scheme, more than A0 grade, in the more preferred technical scheme, more than A00 grade, the bubble degree is excellent, and the thermal expansion coefficient (α)_-30℃-70℃)≤75×10^-7Per K, more preferably α_-30℃-70℃≤70×10^-7and/K, the degree of expansion or contraction due to temperature is low. Meanwhile, the anti-crystallization coating has excellent anti-crystallization performance.

Glass preform examples

The optical glasses obtained in examples 1 to 48 were cut into a predetermined size, and then a release agent was uniformly applied to the surface of the optical glass, followed by heating, softening and press-molding to prepare preforms of various lenses and prisms such as a concave meniscus lens, a convex meniscus lens, a biconvex lens, a biconcave lens, a plano-convex lens, and a plano-concave lens. Alternatively, preforms for precision press molding were formed using the optical glasses obtained in examples 1 to 48, and then precision press molding was carried out to form lenses and prisms, thereby producing preforms.

Optical element embodiments

The preforms obtained in the above examples of glass preforms were annealed to reduce the deformation in the glass and to fine-tune the optical properties such as refractive index to desired values.

Next, each preform is ground and polished to produce various lenses such as a concave meniscus lens, a convex meniscus lens, a biconvex lens, a biconcave lens, a plano-convex lens, and a plano-concave lens, and prisms. The surface of the resulting optical element may be coated with an antireflection film.

Optical instrument embodiments

The optical element produced by the above-described embodiments of the optical element can be used, for example, for imaging devices, sensors, microscopes, medical technology, digital projection, communication, optical communication technology/information transmission, optics/illumination in the automotive field, lithography, excimer lasers, wafers, computer chips, and integrated circuits and electronic devices including such circuits and chips, by optical design, by forming an optical component or optical assembly using one or more optical elements, and particularly for image pickup devices and apparatuses in the automotive field.

Claims

1. Optical glass, characterized by comprising, in weight%: SiO 2₂：0-10％，B₂O₃：5-25％，ZrO₂：0-15％，ZnO：10.1-25％，TiO₂+Nb₂O₅+WO₃：2-30％，Ln₂O₃: 30-55%, the Ln₂O₃Is La₂O₃、Gd₂O₃、Y₂O₃And Yb₂O₃In total, wherein B₂O₃/Ln₂O₃Is 0.3-0.8, Y₂O₃/B₂O₃0.15 to 2; the optical glass does not contain Ta₂O₅。

2. The optical glass according to claim 1, wherein: also contains 0-10% of RO and 0-10% of Rn₂O, 0-1% of clarifying agent, and RO is MOne or more of gO, CaO, SrO or BaO, and the Rn₂O is Li₂O、Na₂O、K₂One or more of O, and Sb as the clarifying agent₂O₃、SnO₂、CeO₂One or more of (a).

3. Optical glass characterized by consisting of 0-10% by weight of SiO₂5-25% of B₂O₃0-15% of ZrO₂10.1-25% of ZnO and 2-30% of TiO₂+Nb₂O₅+WO₃30-55% Ln₂O₃0-10% of RO, 0-10% of Rn₂O, 0-1% of clarifying agent, the Ln₂O₃Is La₂O₃、Gd₂O₃、Y₂O₃And Yb₂O₃RO is one or more of MgO, CaO, SrO and BaO, and Rn₂O is Li₂O、Na₂O、K₂One or more of O, and Sb as the clarifying agent₂O₃、SnO₂、CeO₂Wherein B is₂O₃/Ln₂O₃Is 0.3-0.8, Y₂O₃/B₂O₃Is 0.15-2.

4. An optical glass according to any one of claims 1 to 3, characterized in that: the content of each component meets more than one of the following 4 conditions:

1)SiO₂/(SiO₂+B₂O₃) 0 to 0.25;

2)Y₂O₃/Ln₂O₃0.08-0.45;

3)Y₂O₃/Gd₂O₃0.3 to 3;

4)Y₂O₃/(SiO₂+B₂O₃) Is 0.16-0.8.

5. An optical glass according to any of claims 1 to 3, characterised in thatThe method comprises the following steps: SiO 2₂: 1-8%, and/or B₂O₃: 10-23%, and/or ZrO₂: 1-10%, and/or ZnO: 10.1-20%, and/or TiO₂+Nb₂O₅+WO₃: 4-22%, and/or Ln₂O₃: 35-52%, and/or RO: 0-5%, and/or R₂O: 0-5% and/or clarifying agent 0-0.5%.

6. An optical glass according to any one of claims 1 to 3, characterized in that: the content of each component satisfies more than one of the following 6 conditions:

1)SiO₂/(SiO₂+B₂O₃) 0.05-0.23;

2)Y₂O₃/Ln₂O₃0.1-0.4;

3)Y₂O₃/Gd₂O₃0.5-2.5;

4)Y₂O₃/(SiO₂+B₂O₃) 0.2 to 0.7;

5)B₂O₃/Ln₂O₃0.3-0.6;

6)Y₂O₃/B₂O₃is 0.2-1.5.

7. An optical glass according to any one of claims 1 to 3, characterized in that: SiO 2₂: 1-4%, and/or B₂O₃: 15-20%, and/or ZrO₂: 2-6%, and/or ZnO: 13-17%, and/or TiO₂+Nb₂O₅+WO₃: 10-18%, and/or Ln₂O₃：40-50％。

8. An optical glass according to any one of claims 1 to 3, characterized in that: the content of each component satisfies more than one of the following 6 conditions:

1)SiO₂/(SiO₂+B₂O₃) 0.08-0.2;

2)Y₂O₃/Ln₂O₃is 0.1-0.3；

3)Y₂O₃/Gd₂O₃Greater than 1 but less than or equal to 2;

4)Y₂O₃/(SiO₂+B₂O₃) 0.3-0.6;

5)B₂O₃/Ln₂O₃0.3-0.5;

6)Y₂O₃/B₂O₃is 0.3-1.

9. An optical glass according to any one of claims 1 to 3, characterized in that: nb₂O₅: 1-15%, and/or WO₃: 1-15%, and/or TiO₂: 0-10%, and/or La₂O₃: 20-45%, and/or Gd₂O₃: 0-15%, and/or Y₂O₃: 1-15%, and/or Yb₂O₃：0-5％。

10. An optical glass according to any one of claims 1 to 3, characterized in that: nb₂O₅: 2-10%, and/or WO₃: 2-12%, and/or TiO₂: 0-5%, and/or La₂O₃: 25-40%, and/or Gd₂O₃: 1-10%, and/or Y₂O₃：3-15％。

11. An optical glass according to any one of claims 1 to 3, characterized in that: nb₂O₅: 4-8%, and/or WO₃: 6-10%, and/or La₂O₃: 30-35%, and/or Gd₂O₃: 3-7%, and/or Y₂O₃: 6-10% and/or no TiO₂。

12. An optical glass according to any one of claims 1 to 3, characterized in that: the refractive index of the optical glass is 1.84-1.87, and the Abbe number is 38.0-41.0.

13. The optical glass according to any one of claims 1 to 3, wherein the water-resistant stability of the optical glass powder method is 2 or more types; the powder method has acid stability of more than 3 types.

14. An optical glass according to any of claims 1 to 3, wherein the optical glass has a coefficient of thermal expansion of 75 x 10 or less^-7/K。

15. An optical glass according to any one of claims 1 to 3, wherein the optical glass has a bubble degree of class A or more.

16. An optical glass according to any one of claims 1 to 3, wherein the transition temperature of the optical glass is 640 ℃ or lower; the upper limit temperature of crystallization of the optical glass is 1250 ℃ or lower.

17. An optical glass according to any one of claims 1 to 3, characterized in that: the refractive index of the optical glass is 1.85-1.86.

18. An optical glass according to any one of claims 1 to 3, characterized in that: the abbe number of the optical glass is 38.5-40.0.

19. The optical glass according to any one of claims 1 to 3, wherein the water-resistant stability of the optical glass powder method is class 1.

20. The optical glass according to any one of claims 1 to 3, wherein the acid resistance stability of the optical glass powder method is class 2.

21. An optical glass according to any of claims 1 to 3, wherein the optical glass has a coefficient of thermal expansion of 70 x 10 or less^-7/K。

22. Optical glass according to any of claims 1 to 3, characterised in that it is an optical glassThe bubble degree of the glass is A₀More than grade.

23. An optical glass according to any one of claims 1 to 3, wherein the transition temperature of the optical glass is 630 ℃ or lower.

24. An optical glass according to any of claims 1 to 3, wherein the transition temperature of the optical glass is 625 ℃ or lower.

25. The optical glass according to any one of claims 1 to 3, wherein the upper limit temperature of devitrification of the optical glass is 1200 ℃ or lower.

26. The optical glass according to any one of claims 1 to 3, wherein the upper limit temperature of devitrification of the optical glass is 1180 ℃ or lower.

27. A glass preform made from the optical glass of any of claims 1-26.

28. An optical element made of the optical glass according to any one of claims 1 to 26 or the glass preform according to claim 27.

29. An optical device made using the optical element of claim 28.