WO2013049988A1 - Optical glass and manufacturing method thereof, and optical element - Google Patents

Abstract

The present invention provides an optical glass, which comprises 5wt%-10wt% of SiO₂; 10wt%-18wt% of mixture of B₂O₃ and SiO₂, wherein SiO₂≥B₂O₃; more than 30wt% and less than or equal to 50wt% of La₂O₃; 0-15wt% of mixture of Gd₂O₃, Y₂O₃ and Yb₂O₃, wherein the Gd₂O₃ is 0-12wt%; 10wt%-22wt% of TiO₂; more than 8wt% and less than 15wt% of Nb₂O₅; 0.5wt%-5wt% of ZnO; 0-6wt% of WO₃; 2wt%-10wt% of ZrO₂; more than 2wt% and less than 15wt% of BaO; 0-10wt% of mixture of CaO, SrO and MgO, wherein the SrO is 0-8wt%; 0-0.1wt% of Sb₂O₃; and 0-0.9wt% of SnO.

Description

 Optical glass and its manufacturing method, optical component

 The invention belongs to the technical field of glass, and in particular relates to an optical glass, a manufacturing method thereof and an optical element.

Background technique

 In recent years, with the popularity of digital cameras, digital video cameras, camera phones, and the like, optical systems have been increasingly developed to be high-precision, lightweight, and miniaturized, and glass having a high refractive index is suitable for use as optical components for producing small lenses; In addition, the imaging quality of the optical system is closely related to the transmittance of the optical glass. The higher the transmittance of the glass, the better the imaging quality of the optical system.

 In order to achieve the purpose of improving the optical constant consistency of the optical glass, the prior art generally performs the melting of the optical glass by a two-step melting method, that is, first, the glass batch is melted into a glass crucible, that is, clinker, and then The clinker, which knows the optical constant, is prepared in proportion and then subjected to a second fine smelting to obtain a high quality optical glass blank. In the smelting process of clinker, platinum or quartz crucible is generally used, and platinum is used to increase the use and consumption of expensive platinum, increase the manufacturing cost of glass, and in the process of clinker smelting, platinum. Will enter the glass to cause deterioration of the transmittance of glass, especially high refractive optical glass; and quartz crucible is not only cheap, but does not cause deterioration of glass transmittance. However, when preparing clinker with quartz crucible, in order to avoid the cost increase caused by the large amount of etching of the quartz crucible by the molten glass, the optical glass needs to meet the following requirements, that is, the etching of the quartz crucible by the molten glass at the required melting temperature. The amount should be as low as possible. If the glass solution has a large amount of etching on the quartz crucible, the large amount of wear of the quartz crucible will not only increase the preparation cost of the glass, but also change the composition of the glass, affecting the refractive index and transmittance of the optical glass. Optical performance.

In addition, when the optical glass is formed into a glass material such as a strip, a block or a bar, if the viscosity of the molten glass is too small at the molding temperature, the glass liquid may be streaked due to internal convection or the like, and usually such stripes are Known as forming strips, forming strips reduce the optical properties of the glass, which reduces the imaging quality of the optical system. The prior art generally uses the viscosity of the glass corresponding to the liquidus temperature of the glass, which can be referred to as the viscosity of the liquid phase, to measure the pros and cons of the glass forming property, if the liquid viscosity of the glass is lower than 4 poise (1 poise = ldPa.s) It is difficult to obtain a high-quality product without streaks when the glass is formed into a blank. Therefore, in the preparation of optical glass, it is necessary to consider not only the optical properties of the obtained optical glass. The number, the liquid phase viscosity of the glass must also meet the quality requirements of the molding. However, the optical glass having a high refractive index and good transmittance disclosed in the prior art generally has a low glass liquid viscosity, and it is difficult to meet the quality requirements of the molding.

Summary of the invention

 In view of the above, the technical problem to be solved by the present invention is to provide an optical glass, a manufacturing method thereof, and an optical element. The optical glass provided by the present invention has a refractive index of 1.99 or more, an Abbe number of 23 or more, and a glass forming viscosity of 4.5 poise. The above, not only the optical performance is good, but also the molding performance is good.

 The invention provides an optical glass, comprising:

5 wt% to 10 wt% of Si0 ₂ ;

10 wt% to 18 wt% of B ₂ O ₃ and Si0 ₂ , wherein Si0 ₂ ≥ B ₂ 0 ₃ ;

More than 30% by weight and less than or equal to 50% by weight of La ₂ 0 ₃ ;

0~15^% of Gd ₂ 0 ₃ , Y ₂ 0 ₃ and Yb ₂ 0 ₃ , wherein Gd ₂ 0 ₃ is 0 to 12 wt%;

10wt%~22wt°/々Ti0 ₂ ;

More than 8 wt% and less than 15 wt% of Nb ₂ 0 ₅ ;

 0.5wt%~5wt% ZnO;

0~6wt% of W0 ₃ ;

2wt%~10wt°/々Zr0 ₂ ;

 More than 2wt% and less than 15wt% BaO;

 0~10wt% of CaO, SrO and MgO, wherein SrO is 0~8 wt%;

0~0.1wt% of Sb ₂ 0 ₃ ;

0~0.9wt% of Sn0 ₂ .

Preferably, 31 wt% to 45 wt% of La ₂ O _{3 is included} .

Preferably, it comprises 32.5 wt% to 38 wt% of La ₂ O ₃ .

Preferably, it comprises 0.5wt~15wt°/c^Gd ₂ 0 ₃ , Y ₂ 0 ₃ and Yb ₂ 0 ₃ , wherein Gd ₂ 0 ₃ is 0.5 wt% to 8 wt%.

Preferably, 13 wt% to 22 wt% of Ti0 _{2 is included} .

Preferably, 19.2 wt% to 22 wt% of Ti0 _{2 is included} .

Preferably, it comprises 8.2 wt% to 14 wt% of Nb ₂ 0 ₅ .

Preferably, more than 5 wt% and less than 15 wt% of BaO are included. Preferably, more than 10% by weight and less than 15% by weight of BaO are included.

Preferably, it comprises 3 wt% to 9 wt% of Zr0 ₂ .

Preferably, more than 5.5 wt% and less than 8 wt% of B ₂ O _{3 are included} .

 Preferably, the optical glass has the following properties:

 The refractive index is 1.99 or more;

 The Abbe number is 23 or more;

 The viscosity of the glass liquid phase is 4.5 poise or more;

When the transmittance reaches 70%, the corresponding wavelength λ _{7 ()} is 455 nm or less.

 The invention also provides a method for manufacturing optical glass, comprising the following steps:

 Melting the optical glass clinker described in the above technical solution in a quartz crucible;

The optical glass clinker is subjected to secondary fine melting, clarified, and homogenized to obtain an optical glass. The present invention also provides an optical element formed of the optical glass described in the above technical solution. Compared with the prior art, the optical glass provided by the present invention comprises: 5 wt% to 10 wt. /c^ Si0 ₂ ; 10wt%~18wt. / (^ B ₂ 0 ₃ and Si0 _2, wherein, Si0 ₂ ≥B ₂ 0 _3; greater than 30wt% and 50wt% or less of _{La 2 0 3; 0 ~ 15} ^% of _{Gd 2 0 3, Y 2 0} 3 And Yb ₂ 0 ₃ , wherein Gd ₂ 0 ₃ is 0 to 12 wt%; 10 wt% to 22 wt% of Ti0 ₂ ; more than 8 wt% and less than 15 wt% of Nb ₂ 0 ₅ ; 0.5 wt% to 5 wt% of ZnO; ~6wt% of W0 ₃ ; 2wt%~10wt° / 々Zr0 ₂ ; more than 2wt% and less than 15wt% of BaO; 0~10wt% of CaO, SrO and MgO, wherein SrO is ~ 8 wt%; 0~ 0.1 wt% of Sb ₂ 0 ₃ ; 0 to 0.9 wt% of Sn0 ₂ . The present invention introduces 5 wt% to 10 wt% of SiO ₂ in the optical glass, which not only effectively increases the viscosity of the glass liquid phase, but also reduces the glass liquid. For the etching of quartz crucible, especially when the content of SiO _{2 is} greater than or equal to the content of B ₂ 0 ₃ , the amount of etching of quartz crucible is more significantly reduced; the invention introduces more than 30 wt% and less than or equal to 50 wt% in the optical glass. La ₂ 0 ₃ , ensuring the optical constant of the optical glass in the case where the content of B ₂ 0 _{3 is} low; the invention introduces 10 wt% to 22 wt ° / 々 Ti 0 ₂ in the optical glass, which significantly increases the refraction of the glass Rate, effectively reducing the density of the glass, while introducing more than 2wt% To 15wt% of BaO, Ti0 ₂ is introduced to effectively improve the degree of coloring caused by such phenomena deteriorates. The present invention, by optimizing the glass formulation, to obtain an optical glass having good optical properties not only a higher refractive index, Abbe number, etc. And having a high glass liquid viscosity and other good molding properties. Experiments show that the optical glass provided by the present invention has a refractive index of 1.99 or more; Abbe number is 23 or more; glass liquid viscosity reaches 4.5 poise or more; transmittance When the ratio reaches 70%, the corresponding wavelength λ _{7 ()} is 455 nm or less. detailed description

 The technical solutions in the embodiments of the present invention will be clearly and completely described below. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

 The invention provides an optical glass, comprising:

5 wt% to 10 wt% of Si0 ₂ ;

10 wt% to 18 wt% of B ₂ O ₃ and Si0 ₂ , wherein Si0 ₂ ≥ B ₂ 0 ₃ ;

More than 30% by weight and less than or equal to 50% by weight of La ₂ 0 ₃ ;

0~15^% of Gd ₂ 0 ₃ , Y ₂ 0 ₃ and Yb ₂ 0 ₃ , wherein Gd ₂ 0 ₃ is 0 to 12 wt%;

10wt%~22wt°/々Ti0 ₂ ;

More than 8 wt% and less than 15 wt% of Nb ₂ 0 ₅ ;

 0.5wt%~5wt% ZnO;

0~6wt% of W0 ₃ ;

2wt%~10wt°/々Zr0 ₂ ;

 More than 2wt% and less than 15wt% BaO;

 0~10wt% of CaO, SrO and MgO, wherein SrO is 0~8 wt%;

0~0.1wt% of Sb ₂ 0 ₃ ;

0~0.9wt% of Sn0 ₂ .

Si0 ₂ is an important form of forming an optical oxide. In the present invention, not only the optical constant of the glass is adjusted, but also the anti-devitrification effect of the glass is maintained, and by adjusting the content thereof, the viscosity of the glass liquid phase is effectively increased, and the viscosity is lowered. The effect of glass liquid on the etching of quartz crucibles. In the present invention, when the content of Si0 _{2 is} less than 5% by weight, the effect of increasing the viscosity of the liquid phase of the glass cannot be achieved; when the content is more than 10% by weight, the melting property of the glass is deteriorated, and it is difficult to achieve a high refractive index; therefore, the content of Si0 ₂ It is limited to 5 wt% to 10 wt%, preferably 6 wt% to 9 wt%, more preferably 6.5 wt% to 8.5 wt%.

B ₂ 0 _{3 is} also a bulk oxide of glass, which can effectively improve the thermal stability and chemical stability of the glass, increase the resistance to devitrification of the glass, increase the dissolution rate of the glass to the high refractive index oxide, and increase the glass. Mechanical properties. In the present invention, the total content of B ₂ O ₃ and SiO ₂ is from 10% by weight to 18% by weight, preferably from 12% by weight to 18% by weight, more preferably from 12.5% by weight to 16% by weight. The inventors have found through research that when the content of Si0 ₂ is kept higher than or equal to the content of B ₂ 0 ₃ , the vitreous quartz crucible can be significantly lowered. Etching amount of the crucible; Further, if the content of Si0 ₂ content greater than or equal to 0 ₃ B _2, especially 0 ₃ content is controlled within a range of more than 8wt% and less than 5.5wt%, and preferably from 6wt% ~ 7.5wt% When obtained, the optical glass can not only maintain a high refractive index but also have a high glass liquid viscosity, can produce a glass blank without forming streaks, and can solve the problem that the Si0 ₂ content is greater than or equal to the B ₂ 0 ₃ content. The problem of deterioration of glass coloration and the like makes the optical glass of the obtained optical fiber have better light transmission performance.

La ₂ 0 ₃ is an essential component for obtaining a high refractive index glass, and the present invention ensures the optical constant of the optical glass by introducing an appropriate amount of La ₂ O ₃ while reducing the B ₂ 0 ₃ content; when La ₂ 0 ₃ When the content is 30% by weight or less, the refractive index of the glass is insufficient; when the content is more than 50% by weight, the devitrification resistance of the glass is lowered, and it is difficult to obtain a glass which can be stably produced. Therefore, the present invention will La ₂ 0 ₃ The content is limited to more than 30% by weight and less than or equal to 50% by weight, preferably from 31% by weight to 45% by weight, more preferably from 32.5% by weight to 38% by weight.

Yb ₂ 0 ₃ , Y ₂ 0 ₃ and Gd ₂ 0 ₃ all have the effect of increasing the refractive index of the glass and reducing the dispersion. In the present invention, the total content of Yb ₂ 0 ₃ , Y ₂ 0 ₃ and Gd ₂ 0 ₃ is 0~ 15 wt%, preferably 0.5 wt% to 15 wt%, more preferably 1 wt% to 14 wt%. In the present invention, Gd ₂ 0 ₃ can not only increase the refractive index of the glass, but also reduce the dispersion of the glass, and can be mixed with a high refractive index oxide such as La ₂ 0 _{3 to} improve the production stability of the glass. The content of the Gd ₂ 0 ₃ is 0 wt% to 12 wt%, preferably 0.5 wt% to 8 wt%, more preferably 0.5 wt% to 2.5 wt%. When the Gd ₂ 0 ₃ content is less than 0.5% by weight, although the refractive index and the dispersion are lowered, the effect is not remarkable; when the Gd ₂ 0 ₃ content is more than 12% by weight, the glass resistance is lowered. In the present invention, the content of the Yb ₂ 0 ₃ is preferably 0 wt% to 2 wt%, more preferably 0.1 wt% to 0.8 wt%; and the content of Y ₂ 0 ₃ is preferably 0 wt% to 2 wt%, more preferably 0.1. Wt%~lwt%.

Nb ₂ 0 ₅ can increase the refractive index of the glass and can improve the resistance to devitrification of the glass. When the content is 8 wt% or less, the above effect is not obvious, but when the content of Nb ₂ 0 ₅ is 15 wt% or more, the transmission of the glass The rate deteriorates, especially the transmittance on the short-wavelength side sharply deteriorates; therefore, the present invention limits the content of Nb ₂ 0 ₅ to more than 8 wt% to less than 15 wt%, preferably from 8.2 wt% to 14 wt%, more preferably 8.2 wt%. 12wt%.

In the present invention, Ti0 ₂ can significantly increase the refractive index of the glass and enhance the chemical stability, and an appropriate amount of introduction can also effectively reduce the glass density, but when the Ti0 ₂ content is less than 10 wt%, the low-density performance of the glass is not obvious, and the content thereof exceeds 22wt%, glass transition temperature rises sharply, glass The coloring is increased. Therefore, the present invention limits the content of Ti0 ₂ to 10 wt% to 22 wt%, preferably 13 wt% to 22 wt%, more preferably 19.2 wt% to 22 wt%, and most preferably 19.5 wt% to 21.8 wt%. It is also preferably from 19.7 wt% to 21.5 wt%.

BaO can effectively adjust the optical constant of the glass. In the present invention, not only the refractive index of the glass can be increased, the dispersion can be reduced, but also the phenomenon of poor coloration due to the introduction of Ti0 ₂ can be effectively improved, and the chemical stability can be improved. The carbonate or nitrate form also has the effect of promoting glass defoaming when used as a raw material; in the present invention, the BaO content is more than 2% by weight and less than 15% by weight, preferably more than 5% by weight and less than 15% by weight, more preferably More than 10 wt% is less than 15 wt%, and most preferably 12 wt% to 14 wt%. When the content of BaO is 2% by weight or less, the effect is not remarkable, and when the content is 15% by weight or more, the glass resistance is impaired, and it is difficult to obtain a glass which can be stably produced.

Wo ₃ can increase the refractive index of the optical glass, and when it is added in a small amount, the devitrification resistance of the glass can also be improved. In the invention, an appropriate amount of introduction can also effectively improve the crystallization property of the glass. However, when the content is more than 6 wt% and coexists with Ti0 ₂ and Nb ₂ 0 ₅ , the transmittance of the glass is deteriorated, and particularly, the transmittance on the short-wavelength side is rapidly deteriorated, and the glass is extremely easy to develop color. Therefore, the present invention limits the content of W0 ₃ to 0 wt% to 6 wt%, preferably 0.1 wt% to 3 wt%, more preferably 0.4 wt% to 1 wt%.

 ZnO can lower the glass transition temperature of glass, and can also improve the anti-devitrification of glass and reduce the viscous flow temperature of glass. The content of ZnO is from 0.5 wt% to 5 wt%, preferably from 1.5 wt% to 4 wt%, more preferably from 1.5 wt% to 2.5 wt%. When the ZnO content is less than 0.5% by weight, the glass transition temperature of the glass is not significantly lowered; when the content of ZnO is more than 5% by weight, the refractive index of the glass is lowered.

Zr0 ₂ can moderately increase the refractive index and thermal stability of the glass, and when it is added in a small amount, it can improve the devitrification resistance of the glass. However, if the amount of addition is too large, the devitrification resistance of the glass is drastically lowered. The invention limits the content of ZrO ₂ to 2 wt% to 10 wt%, preferably 3 wt% to 9 wt%, more preferably 5 wt% to 7 wt%.

CaO, SrO, and MgO may be appropriately introduced in the present invention, and the total content of CaO, SrO, and MgO is from 0 wt% to 10 wt%, preferably from 0 wt% to 5 wt%, more preferably from 0.5 wt% to 3.5 wt%; wherein, CaO The content of MgO is preferably 0 wt% to 1 wt%, more preferably 0.5 wt% to 1 wt%; the content of SrO is preferably 0 wt% to 8 wt%, more preferably 0.1 wt% to 5 wt%; and the content of MgO is preferably 0 wt% to 2 wt%. %, more preferably 0.5% by weight to 1% by weight. Sb ₂ 0 ₃ and Sn0 ₂ can be used not only for defoaming but also for the melting atmosphere of the glass. The present invention limits the content of Sb ₂ 0 ₃ to 0 wt% to 0.1 wt%, preferably 0.005 wt% to 0.09 wt%, more preferably 0.01 wt% to 0.08 wt%; and the content of Sn0 ₂ is limited to 0 wt% to 0.9 wt. % is preferably 0.001% by weight to 0.85% by weight, more preferably 0.01% by weight to 0.08% by weight.

By optimizing the glass formulation, the obtained optical glass not only has good optical properties such as high refractive index and Abbe number, but also has good molding properties such as high glass liquid viscosity. In the present invention, the refractive index of the optical glass is preferably 1.99 or more, more preferably 1.993 or more, most preferably 1.995 or more, and most preferably 2.0 to 2.1; and the Abbe number is preferably 23 or more, and more preferably 24 or more. Most preferably 25 or more, most preferably 23 to 29; the glass liquid viscosity is preferably 4.5 poise or more, more preferably 4.7 poise or more, most preferably 5 poise or more, and most preferably 5.5 poise or more; The wavelength λ _{7 ()} corresponding to 70% is preferably 455 nm or less, more preferably 454 nm or less, and most preferably 450 nm or less.

 The invention also provides a method for manufacturing optical glass, comprising the following steps:

 Melting the optical glass clinker described in the above technical solution in a quartz crucible;

 The optical glass clinker is subjected to secondary fine melting, clarified, homogenized, and cooled to obtain an optical glass.

 According to the present invention, the oxide, hydroxide, carbonate or nitrate of the component described in the above technical solution is used as a raw material, and the mixture is thoroughly mixed and placed in a quartz crucible for the first smelting. Since the silica content in the glass is high, the etching of the quartz crucible is small, so that the cost can be reduced. In the present invention, the temperature of the first smelting is preferably from 1160 °C to 1200 °C, more preferably from 1170 °C to 1190 °C.

 After the first smelting is completed, a glass clinker, which is commonly known as a glass crucible, is obtained; the glass clinker is subjected to secondary refining, and after the glass is clarified and homogenized, a molten glass is obtained. In the present invention, the secondary finish smelting is preferably carried out in a platinum crucible, and the temperature of the finish smelting is preferably from 1280 °C to 1350 °C, more preferably from 1290 °C to 1340 °C. The finely smelted glass liquid is lowered into a preheated metal mold by dropping to 1,250 ° C, preferably 1200 ° C or less, according to a method well known to those skilled in the art, and quenching to obtain an optical glass.

 The performance test of the optical glass is as follows:

The refractive index (nd) value is (-2 ° C / h) - ( -6 ° C / h) annealing value, refractive index and Abbe number according to the colorless optics provided in GB/T 7962.1-1987 Measurement of refractive index and dispersion coefficient of glass Test method to test;

The glass was made into a sample having a thickness of 10 mm ± 0.1 mm, and the glass was tested to have a transmittance of 70% corresponding to the wavelength λ _{7 ()} .

 The viscosity is tested using a BROOKFIELD DV-ΠΙ ULTRA type high temperature rotational viscometer or a plate viscometer.

A glass crucible of about 50 cm ³ was placed in a plurality of platinum crucibles, and then placed in a ladder furnace with a temperature gradient of 10 ° C for two hours. The glass was taken out and cooled, and the glass was not observed. The lowest temperature of crystallization is the liquidus temperature.

 The optical glass provided by the present invention has been tested to have the following properties:

 The refractive index is 1.99 or more;

 The Abbe number is 23 or more;

 The liquidus viscosity is above 4.5 poise;

When the transmittance reaches 70%, the corresponding wavelength λ _{7 ()} is 455 nm or less.

 The present invention also provides an optical element formed by the optical glass described in the above technical solution in accordance with a method well known to those skilled in the art. Since the optical glass has a high refractive index and a high transmittance, the optical element also has a high refractive index and a high transmittance, and can be applied to devices such as digital cameras, digital video cameras, and camera phones.

Compared with the prior art, the optical glass provided by the present invention comprises: 5 wt% to 10 wt. /c^ Si0 ₂ ; 10wt%~18wt. / (^ B ₂ 0 ₃ and Si0 _2, wherein, Si0 ₂ ≥B ₂ 0 _3; greater than 30wt% and 50wt% or less of _{La 2 0 3; 0 ~ 15} ^% of _{Gd 2 0 3, Y 2 0} 3 And Yb ₂ 0 ₃ , wherein Gd ₂ 0 ₃ is 0 to 12 wt%; 10 wt% to 22 wt% of Ti0 ₂ ; more than 8 wt% and less than 15 wt% of Nb ₂ 0 ₅ ; 0.5 wt% to 5 wt% of ZnO; ~6wt% of W0 ₃ ; 2wt%~10wt° / 々Zr0 ₂ ; more than 2wt% and less than 15wt% of BaO; 0~10wt% of CaO, SrO and MgO, wherein SrO is ~ 8 wt%; 0~ 0.1 wt% of Sb ₂ 0 ₃ ; 0 to 0.9 wt% of Sn0 ₂ . The optical glass obtained by the invention is optimized not only has high refractive index, Abbe number and the like, but also has good optical properties. Good moldability such as higher glass liquid viscosity.

 In order to further understand the present invention, the preferred embodiments of the present invention are described in the accompanying drawings.

Example 1~14 Glass composition w According to the following steps, optical glass is produced according to the ratio of raw materials shown in Table 1 and Table 2:

%

 The raw materials described in Table 1 were thoroughly mixed and placed in a quartz crucible. After the first melting, the glass crucible was formed into a glass crucible, and the glass crucible was placed in a platinum crucible, and the second fine melting was performed. After the glass was clarified and homogenized, Molten glass

 The molten glass is lowered to 1200 ° C or lower, poured into a preheated metal mold, and cooled to obtain an optical glass.

 The optical glass was subjected to performance test, and the results are shown in Table, Table 1 and Table 2 are performance parameters of the optical glass prepared in the examples of the present invention.

 Comparative example 1~2

 According to the following steps, the optical glass was prepared according to the ratio of raw materials shown in Table 1 and Table 2: The raw materials described in Table 1 were thoroughly mixed and placed in a quartz crucible. After the first melting, the glass crucible was formed, and then the glass crucible was formed. Put into the platinum crucible, the second fine smelting, after the glass is clarified and homogenized, the molten glass is obtained;

 The molten glass is lowered to 1200 ° C or lower, poured into a preheated metal mold, and cooled to obtain an optical glass.

 The optical glass was subjected to performance test, and the results are shown in Table, Table 1 and Table 2 are performance parameters of the optical glass prepared in the examples of the present invention.

 Table 1 Performance parameters of optical glass prepared in Examples 1 to 8 of the present invention

 Buying a case 1 2 3 4 5 6 7 8

Si0 ₂ +B ₂ 0 ₃ 14.8 14.7 15.5 16.5 13.2 15 17.6 15.4

Si0 ₂ 7.5 7.7 8.3 8.5 7.0 7.3 9.0 8.1

B ₂ 0 ₃ 7.3 7.0 7.2 7.0 6.2 7.7 8.6 7.3

La ₂ 0 ₃ 34 35.1 37 34.2 34.2 34 33.5 35

Gd ₂ 0 ₅ +Y ₂ 0 ₃ +Yb

2 1.5 0.5 0.9 0.4 1 1.9 0 20 ₃

Gd ₂ 0 ₅ 2 1.5 0 0.9 0.4 1 1.9 0

Yb ₂ 0 ₃ 0 0 0.5 0 0 0 0 0

Ti0 ₂ 18.9 19.0 18.3 18.7 18.4 19.7 21.5 21 b ₂ 0 ₅ 9.6 8.3 9.1 8.1 10.2 8.8 8.5 11.3

W0 ₃ 0.3 0 0 0 0 0.5 0.6 0

Zr 0 ₂ 3.5 6.6 5.5 6.5 8.2 6.2 4.7 6.0

ZnO 2.2 2.9 1 3.4 3.0 2.3 0.9 0.8

BaO 14.7 10.9 12.6 11.7 12.4 12.5 10.8 10.5

CaO+SrO+MgO 0 1 0.5 0 0 0 0 0 CaO 0 0 0.5 0 0 0 0 0

SrO 0 1 0 0 0 0 0 0

MgO 0 0 0 0 0 0 0 0

Sb ₂ 0 ₃ 0.05 0.02 0.03 0 0.06 0.05 0.05 0

Sn0 ₂ 0 0 0 0.1 0 0 0 0.05 Total 100 100 100 100 100 100 100 100 First melting temperature ( °C ) 1160 1165 1170 1175 1180 1185 1190 1195 Second fine melting temperature ( ) 1280 1285 1290 1295 1300 1350 1295 1285

 Refractive index (

5.54 25.26 乡 液相粘度（dPa.s ) 5.5 6 6.3 6.5 5 5.5 7.6 6.1 λ70(ηηι) 450 450 448 450 455 452 450 454 Abbe number ( ― 2

5.54 25.26 Township liquid viscosity (dPa.s) 5.5 6 6.3 6.5 5 5.5 7.6 6.1 λ70(ηηι) 450 450 448 450 455 452 450 454

Table 2 Performance parameters of optical glasses prepared in Examples 9 to 14 and Comparative Examples of the present invention

 Comparative comparison Example 9 10 11 12 13 14

 Example 1 Example 2

Si0 ₂ +B ₂ 0 ₃ 13.1 13.8 13.4 12.9 17.0 15.1 14.46 16.8

Si0 ₂ 6.8 7 6.8 6.5 9.0 8.0 6.16 6.3

B ₂ 0 ₃ 6.3 6.8 6.6 6.4 8.0 7.1 8.3 10.5

La ₂ 0 ₃ 40.9 45.3 40.4 44 35.4 34.6 33.41 34

Gd ₂ 0 ₅ +Y ₂ 0 ₃ +Yb ₂

10.4 9 11 10.7 0 1 0 0 o ₃

Gd ₂ 0 ₃ 10.4 8 9 9 0 0 0 0

Y ₂ 0 ₃ 0 1 2 1.7 0 1 0 0 Glass Yb ₂ 0 ₃ 0 0 0 0 0 0 0 0 Glass Ti0 ₂ 13.8 13.6 13 13.2 20 20.5 20.29 18.5 Group Nb ₂ 0 ₅ 8.5 8 9.7 8.2 9.5 11.2 8.32 7.1 W0 ₃ 0 0 0 0 0 0 0 0

( wt % ) Zr0 ₂ 7 6 5.8 6 3.0 3.5 6.54 4.5

 ZnO 0.5 1.5 0.7 1 1.5 1.9 1.31 2.1

BaO 5.8 2.8 6 4 13.6 12.2 15.66 17

CaO+SrO+MgO 0 0 0 0 0 0 0 0

CaO 0 0 0 0 0 0 0 0

SrO 0 0 0 0 0 0 0 0

MgO 0 0 0 0 0 0 0 0

Sn02 0 0 0.2 0 0 0 0 0

Sb ₂ 0 ₃ 0.01 0 0 0 0.4 0 0.01 0 Total 100 100 100 100 100 100 100 100 First melting temperature ( °C ) 1160 1165 1170 1200 1180 1185 1190 1195 Second finishing smelting temperature (°c ) 1280 1285 1290 1295 1300 1350 1295 1285 W t _Λ ^ 2.0000 1.9991 1.9952 2.0025 1.995 2.017 2.0006 1.9980 Refractive index

l _iL ^ 9 6 0 8 4 3 9 0 performance,

_iL Abbe number 28.56 28.94 28.85 29.23 25.45 25.24 25.46 24.9 Parameters

Liquid phase viscosity (dPa.s) 4.8 4.9 4.9 4.7 7.8 5.8 3.58 3.4 λ70 (ηιη) 438 436 435 436 450 454 470 466 As can be seen from Tables 1 and 2, the optical glass provided by the present invention has a high refractive index and a high transmission. The ratio and the higher viscosity of the glass liquid phase; and when the content of SiO ₂ is lower than that of B ₂ 0 ₃ , since the liquidus viscosity of the glass becomes small, streaks are easily generated in the glass forming process, and the coloration of the glass is deteriorated.

 The above description is only a preferred embodiment of the present invention, and it should be noted that those skilled in the art can also make several improvements and retouchings without departing from the principles of the present invention. It should be considered as the scope of protection of the present invention.

Claims

1. An optical glass comprising: 5 wt% to 10 wt% of Si0 ₂ ; 10 wt% to 18 wt% of B ₂ O ₃ and Si0 ₂ , wherein Si0 ₂ ≥ B ₂ 0 ₃ ; More than 30% by weight and less than or equal to 50% by weight of La ₂ 0 ₃ ; 0~15^% of Gd ₂ 0 ₃ , Y ₂ 0 ₃ and Yb ₂ 0 ₃ , wherein Gd ₂ 0 ₃ is 0 to 12 wt%; 10wt%~22wt°/々Ti0 ₂ ; More than 8 wt% and less than 15 wt% of Nb ₂ 0 ₅ ;  0.5wt%~5wt% ZnO; 0~6wt% of W0 ₃ ; 2wt%~10wt°/々Zr0 ₂ ;  More than 2wt% and less than 15wt% BaO;  0~10wt% of CaO, SrO and MgO, wherein SrO is 0~8 wt%; 0~0.1wt% of Sb ₂ 0 ₃ ; 0~0.9wt% of Sn0 ₂ . The optical glass according to claim 1, comprising 31% by weight to 45% by weight of La ₂ O ₃ . The optical glass according to claim 2, which comprises 32.5 wt% to 38 wt% of La ₂ O ₃ . The optical glass according to claim 1, comprising 0.5 wt% to 15 wt% of Gd ₂ O ₃ , Y ₂ 0 ₃ and Yb ₂ 0 ₃ , wherein Gd ₂ 0 ₃ is 0.5 wt% to 8 wt. %. The optical glass according to claim 1, comprising 13 wt% to 22 wt% of Ti0 ₂ . The optical glass according to claim 5, which comprises 19.2% by weight to 22% by weight of Ti0 ₂ . The optical glass according to claim 1, comprising 8.2 wt% to 14 wt% of Nb ₂ 0 ₅ . 8. The optical glass according to claim 1, comprising more than 5 wt% and less than 15 wt% of BaO. The optical glass according to claim 8, which comprises more than 10% by weight and less than 15% by weight of BaO. The optical glass according to claim 1, comprising 3 wt% to 9 wt% of Zr0 ₂ . The optical glass according to claim 1, comprising more than 5.5 wt% and less than 8 wt% of B ₂ O ₃ .  The optical glass according to any one of claims 1 to 11, wherein the optical glass has the following properties:  The refractive index is 1.99 or more;  The Abbe number is 23 or more;  The viscosity of the glass liquid phase is 4.5 poise or more; When the transmittance reaches 70%, the corresponding wavelength λ _{7 ()} is 455 nm or less.  13. A method of manufacturing an optical glass, comprising the steps of:  The optical glass clinker according to any one of claims 1 to 12 is melted in a quartz crucible; the optical glass clinker is subjected to secondary fine melting, clarified, homogenized, and cooled to obtain an optical glass.  An optical element comprising the optical glass according to any one of claims 1 to 12.