A special optical glass, its preparation method and application

Abstract

The present invention relates to a special optical glass, a preparation method thereof and an application. The preparation method comprises the following steps: 1) Weigh raw materials according to the component ratio of the special optical glass and mix them evenly; by weight percentage, the components of the special optical glass include: Bi 2 O 3 : 30% - 40%; Ga 2 O 3 : 20% - 30%; B 2 O 3 : 15% - 25%; Tb 2 O 3 : 2% - 8%; BaO: 2% - 6%; La 2 O 3 : 1% - 5%; Nb 2 O 5 : 1% - 5%; HfO 2 : 1% - 5%; SiO 2 : 0% - 5%; 2) Melting the mixture into glass liquid under a vacuum condition with a pressure ≤ 0.01 Pa, clarifying and homogenizing the glass liquid under stirring conditions, forming, and annealing to obtain the special optical glass; wherein, the container and stirrer in contact with the glass liquid during the melting process are made of Pt material. The technical problem to be solved by the present invention is how to prepare a special optical glass that has both high transmittance (the internal transmittance at 440 nm ≥ 94%) and high refractive index (n d ≥ 2.0), and also has good chemical stability and optical homogeneity, its water resistance stability is better than grade 1, and the optical homogeneity is better than 3×10 ‑5 .

Description

Technical Field

[0001] The present invention belongs to the technical field of special glass, and in particular relates to a special optical glass and a preparation method and application thereof. Background Art

[0002] Refractive index is an important indicator of optical glass. High refractive index glass is an important component of the optical system. High refractive index optical glass can make optical components have the characteristics of ultra-wide viewing angle, which can enable the system to obtain a wider field of view and higher-definition optical clarity. At the same time, it is conducive to the miniaturization and wearability of components. Therefore, it is very important for the development of important technologies such as humanities, high-end materials and industrial robots, professional cameras, and semiconductor integrated circuit chip short-wave lithography. In the future, it is expected to be more used in automotive autonomous driving cameras, optical information science, augmented reality and mixed reality.

[0003] The high refractive index glass in the prior art often has a low transmittance due to the characteristics of the components and the preparation process. Although those skilled in the art have conducted a lot of research on the component ratio and preparation process of high refractive index glass, it is still difficult for the current optical glass to take into account both the high refractive index and high transmittance of the glass, and the chemical resistance and optical uniformity of the glass are not good, which greatly restricts the application and promotion of optical glass in the field of special glass. Therefore, how to prepare a composite functional glass with both high transmittance and high refractive index and good comprehensive performance has become an urgent problem to be solved in this field. Summary of the invention

[0004] The main purpose of the present invention is to provide a special optical glass and its preparation method and application. The technical problem to be solved is how to prepare a special optical glass with both high transmittance (internal transmittance at 440nm ≥ 94%) and high refractive index (n d ≥2.0), and also has good chemical stability and optical uniformity. Its water resistance is better than level 1, and its optical uniformity is better than 3×10 -5 , making it more suitable for practical use.

[0005] The purpose of the present invention and the technical problem to be solved are achieved by adopting the following technical solutions. According to a method for preparing special optical glass proposed by the present invention, the method comprises the following steps:

[0006] 1) Weigh the raw materials according to the composition ratio of the special optical glass and mix them evenly; in terms of weight percentage, the components of the special optical glass include: Bi 2 O 3 :30%-40%; Ga 2 O 3 : 20%-30%; B 2 O3 :15%-25%; Tb 2 O 3 : 2%-8%; BaO: 2%-6%; La 2 O 3 :1%-5%; Nb 2 O 5 :1%-5%; HfO 2 :1%-5%; SiO 2 : 0%-5%;

[0007] 2) Melting the mixture into glass liquid under vacuum conditions with a pressure of ≤0.01Pa, clarifying and homogenizing the glass liquid under stirring conditions, shaping, and annealing to obtain special optical glass; wherein, the container and stirrer in contact with the glass liquid during the melting process are made of Pt material.

[0008] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0009] Preferably, in the above-mentioned preparation method, the components of the special optical glass include: Bi 2 O 3 :35%-40%; Ga 2 O 3 : 20%-25%; B 2 O 3 :15%-20%; Tb 2 O 3 : 2%-5%; BaO: 4%-6%; La 2 O 3 :1%-3%; Nb 2 O 5 :1%-3%; HfO 2 :1%-3%; SiO 2 : 3%-5%.

[0010] Preferably, in the aforementioned preparation method, the pressure ranges from 0.001Pa to 0.01Pa.

[0011] Preferably, in the aforementioned preparation method, the Pt material is zirconium-reinforced Pt, wherein the zirconium oxide content is 100-1000 ppm.

[0012] Preferably, in the aforementioned preparation method, the melting temperature is 1300°C-1360°C, and the time is 3h-5h; the stirring is carried out using a frame stirrer, the rotation speed is 30rpm-50rpm, and the time is 1h-2h; the molding temperature is 1050°C-1100°C, and the preheating mold temperature is 300°C-350°C; the annealing temperature is 500°C-550°C, and the annealing time is 3h-6h.

[0013] The purpose of the present invention and the technical problem to be solved are also achieved by the following technical solutions. According to the special optical glass proposed by the present invention, it includes the following oxide components in terms of weight percentage: Bi 2 O 3 :30%-40%;Ga 2 O 3 : 20%-30%; B 2 O 3 :15%-25%; Tb 2 O 3 : 2%-8%; BaO: 2%-6%; La 2 O 3 :1%-5%; Nb 2 O 5 :1%-5%; HfO 2 :1%-5%; SiO 2 : 0%-5%; the refractive index of the special optical glass n d ≥2.0, internal transmittance at 440nm ≥94%, water resistance stability better than level 1, optical uniformity better than 3×10 -5 .

[0014] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0015] Preferably, the aforementioned special optical glass does not contain TiO 2 .

[0016] Preferably, the aforementioned special optical glass is prepared according to the aforementioned preparation method.

[0017] The purpose of the present invention and the technical problem solved by the present invention are also achieved by the following technical solutions: A lens proposed by the present invention is made of the aforementioned special optical glass.

[0018] The purpose of the present invention and the technical problem solved by the present invention are also achieved by the following technical solutions: According to the present invention, a lens as mentioned above is applied in the field of virtual reality, digital camera, microscope, or vehicle-mounted display technology.

[0019] By means of the above technical solution, the special optical glass and its preparation method and application proposed by the present invention have at least the following advantages:

[0020] The invention provides a special optical glass and a preparation method and application thereof. Firstly, the components of the special optical glass are designed to contain a large amount of heavy metal oxide Bi. 2 O 3 , Tb 2 O3 , Nb 2 O 5 and BaO, making the refractive index of the special optical glass body n d ≥2.0; then by designing special optical glass components containing a certain amount of Ga 2 O 3 and HfO 2 , so that it can have good chemical stability, and its water resistance stability is better than level 1; finally, by designing the special optical glass components without the coloring component TiO 2 To avoid TiO 2 The transmittance of special optical glass is affected; at the same time, the preparation process is controlled by melting under vacuum conditions with a pressure of ≤0.01Pa, which avoids the oxidation of impurity iron elements in the raw material components to Fe 2+ and Fe 3+ , avoiding Fe 3+ The transmittance of the special optical glass is affected; through the combined effect of various technical means such as the component ratio design of the special optical glass and melting under specific vacuum conditions, it is ensured that the internal transmittance of the special optical glass at 440nm can be as high as 94% or more; since the special optical glass of the technical solution of the present invention contains a large amount of heavy metals, most of which are elements with large atomic coefficients, mainly heavy metal elements, and are highly corrosive, in order to avoid the corrosion of the crucible container, the stirrer and other parts when they are in contact with the high-temperature glass liquid due to the corrosiveness of the mixed material during the melting process, the corroded crucible container and the stirrer may introduce unwanted elements The elements and ions are mixed into the glass liquid, which leads to poor optical uniformity of the special optical glass and makes it useless. In the technical solution of the present invention, the glass is melted under strict vacuum conditions, and the materials of the container and the stirrer in contact with the glass liquid during the melting process are controlled to be Pt materials. Since the Pt material has a high tolerance to the glass liquid of the special optical glass of the present invention, the corrosion of the container and the stirrer by the heavy metal content in the special optical glass formula of the present invention is avoided, and the influence of the material of the container and the stirrer on the optical uniformity of the special optical glass is avoided, so that the optical uniformity of the special optical glass of the present invention is better than 3×10 -5 The technical solution of the present invention uses the above-mentioned multiple technical means in a comprehensive manner, and the technical features cooperate and support each other, and finally obtains a special optical glass with good comprehensive performance; the refractive index n of the special optical glass prepared by the present invention is d ≥2.0, internal transmittance at 440nm ≥94%, water resistance stability better than level 1, optical uniformity better than 3×10 -5, which can be used in technical fields such as virtual reality, digital cameras, microscopes or car displays, greatly promoting the application and promotion of special optical glass in the field of special glass.

[0021] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail as follows. DETAILED DESCRIPTION

[0022] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of a special optical glass and its preparation method and its specific implementation, structure, characteristics and effects proposed by the present invention in combination with the preferred embodiments. In the following description, different "one embodiment" or "embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0023] The present invention provides a method for preparing special optical glass, which comprises the following steps:

[0024] 1) Weigh the raw materials according to the composition ratio of the special optical glass and mix them evenly; in terms of weight percentage, the components of the special optical glass include: Bi 2 O 3 :30%-40%;Ga 2 O 3 : 20%-30%; B 2 O 3 :15%-25%; Tb 2 O 3 : 2%-8%; BaO: 2%-6%; La 2 O 3 :1%-5%; Nb 2 O 5 :1%-5%; HfO 2 :1%-5%; SiO 2 : 0%-5%;

[0025] 2) Melting the mixture into glass liquid under vacuum conditions with a pressure of ≤0.01Pa, clarifying and homogenizing the glass liquid under stirring conditions, shaping, and annealing to obtain special optical glass; wherein, the container and stirrer in contact with the glass liquid during the melting process are made of Pt material.

[0026] In the above technical solution, the component ratio of the special optical glass, the melting environment of the mixture, especially the vacuum degree of the melting environment and the materials of the container and stirrer contacting the glass liquid work together to obtain the special optical glass of the present invention.

[0027] The special optical glass proposed in the present invention has a refractive index n d ≥2.0, internal transmittance at 440nm ≥94%, water resistance stability better than level 1, optical uniformity better than 3×10 -5 It has both high transmittance and high refractive index, and also has good chemical stability and optical uniformity.

[0028] In the special optical glass component of the present invention, B 2 O 3 The component is an important network former of the special optical glass provided by the present invention, which can improve the glass-forming ability of the glass. 2 O 3 The weight percentage of the component is controlled to be 15%-25%, preferably 15%-20%, so that the special optical glass can obtain a homogeneous glass body and ensure that the special optical glass has a high refractive index. If the weight percentage of the component is less than 15%, its glass-forming ability becomes poor; and if the weight percentage of the component exceeds 25%, the refractive index of the glass will decrease.

[0029] SiO 2 The component is an important network former of the special optical glass provided by the present invention, which can improve the glass-forming ability, strength and chemical stability of the glass. If the component is not added to the special optical glass, its glass-forming ability and chemical properties will deteriorate. At this time, if a larger glass is prepared, surface crystallization problems may occur, so it can only be used to prepare smaller glasses. In the embodiment of the present invention, SiO 2 The weight percentage of the component is controlled to be 0%-5%, preferably 1%-5%, and more preferably 3%-5%, so that a homogeneous glass body can be obtained and the special optical glass can have a high refractive index. If the weight percentage of the component exceeds 5%, the refractive index of the special optical glass will be reduced.

[0030] Bi 2 O 3 It is a necessary component for special optical glass to have a higher refractive index. The weight percentage of this component is controlled to be 30%-40%, preferably 35%-40%. 2 O 3 If the weight percentage of the component is less than 30%, it is difficult to ensure that the refractive index of the glass is ≥ 2.0. 2 O 3 If the weight percentage of the component exceeds 40%, the chemical stability of the glass may be deteriorated.

[0031] Ga 2 O 3It is a necessary component for special optical glass to have good chemical stability and high refractive index, and can improve the water resistance and refractive index of glass. The weight percentage of this component is controlled at 20%-30%, preferably 20%-25%. If the weight percentage of this component is less than 20%, the water resistance of the glass is not significantly improved; and if the weight percentage of this component exceeds 30%, the glass will crystallize and the glass forming property will deteriorate.

[0032] Tb 2 O 3 It is a component necessary for special optical glass to have a higher refractive index. The weight percentage of this component is controlled to be 2%-8%, preferably 2%-5%. 2 O 3 If the weight percentage of the component is less than 2%, it is difficult to ensure that the refractive index of the glass is ≥ 2.0. 2 O 3 When the weight percentage of the component exceeds 8%, the glass will crystallize and the glass-forming property will deteriorate.

[0033] BaO is a component necessary for special optical glass to have a high refractive index, and the weight percentage of this component is controlled to be 2%-6%, preferably 4%-6%. If the weight percentage of the BaO component is less than 2%, it is difficult to ensure that the refractive index of the glass is ≥2.0, and if the weight percentage of the BaO component exceeds 6%, the chemical stability of the glass will deteriorate.

[0034] La 2 O 3 It is a necessary component for special optical glass to have a higher refractive index. The weight percentage of this component is controlled to be 1%-5%, preferably 1%-3%. 2 O 3 If the weight percentage of the component is less than 1%, it is difficult to ensure that the refractive index of the glass is ≥ 2.0. 2 O 3 When the weight percentage of the component exceeds 5%, the glass will crystallize and the glass-forming property will deteriorate.

[0035] Nb 2 O 5 It is helpful to improve the glass forming properties and refractive index of special optical glass. The weight percentage of this component is controlled at 1%-5%, preferably 1%-3%. If the weight percentage of this component is less than 1%, the refractive index of the glass will not be significantly improved; if the weight percentage of this component exceeds 5%, Nb 2 O 5 It is difficult to fully melt in the glass, and the optical homogeneity of the glass deteriorates.

[0036] HkDJ 2It is a necessary component for special optical glass to have a higher refractive index. The weight percentage of this component is controlled to be 1%-5%, preferably 1%-3%. 2 If the weight percentage of the component is less than 1%, it is difficult to ensure that the refractive index of the glass is ≥ 2.0. 2 When the weight percentage of the component exceeds 5%, the glass will crystallize and the glass-forming property will deteriorate.

[0037] The technical solution of the present invention is to design the components of special optical glass to contain a large amount of heavy metal oxide Bi 2 O 3 , Tb 2 O 3 , Nb 2 O 5 and BaO, making the refractive index of the special optical glass body n d ≥2.0; by designing special optical glass components containing a certain amount of Ga 2 O 3 and HfO 2 , so that it can have good chemical stability, and its water resistance stability is better than level 1; and by designing the special optical glass components without the coloring component TiO 2 To avoid TiO 2 Affects the transmittance of special optical glass.

[0038] The technical solution of the present invention adopts the melting under vacuum conditions with a pressure of ≤0.01Pa in the preparation process control, which avoids the impurity iron element that may be contained in the raw material components from being oxidized to Fe 2+ and Fe 3+ , thus avoiding Fe 3+ It affects the transmittance of special optical glass; through the combined effect of various technical means such as the component ratio design of the above-mentioned special optical glass and melting under specific vacuum conditions, it is ensured that the internal transmittance of special optical glass at 440nm can be as high as 94% or more.

[0039] Since the special optical glass of the technical solution of the present invention contains a large amount of heavy metals, which are highly corrosive, the material of the container and the stirrer in contact with the glass liquid during the melting process is controlled to be Pt material, such as pure platinum, to avoid the corrosion of the container and the stirrer by the heavy metal content in the special optical glass formula of the present invention, and to avoid the influence of the material of the container and the stirrer on the optical uniformity of the special optical glass, so that the optical uniformity of the special optical glass of the present invention is better than 3×10 -5 .

[0040] The pressure range of high temperature melting is preferably 0.001Pa~0.01Pa; the reason for this setting is to ensure that the vacuum degree of high temperature melting is large enough, so that the furnace chamber pressure is ≤0.01Pa, and to prevent the iron element in the raw material impurities from being oxidized to Fe in the atmospheric environment. 3+ , such as in Example 3, which results in aggravated glass coloring and poor internal transmittance; and to prevent the iron element in the raw material impurities from being mainly Fe 3+ It exists in the form of, for example, comparative example 4, resulting in low transmittance in the glass; on the other hand, after the vacuum degree reaches the requirement, further increasing the vacuum degree does not significantly improve the performance of the special optical glass, but will increase unnecessary energy consumption. Therefore, the preferred pressure range of the present invention is preferably 0.001Pa to 0.01Pa.

[0041] The material of the container and the agitator in contact with the glass liquid is further preferably zirconium-reinforced Pt, wherein the zirconium oxide content is 100 to 1000 ppm; the reason for this arrangement is that the glass components of the present invention contain more heavy metals with large atomic coefficients. Although the pure platinum material has a high tolerance to the glass liquid melted at high temperature of the mixture, it still has the possibility of chemical reaction. If a trace amount of Pt enters the glass structure to form a platinum flash point, it will affect the transmittance and optical uniformity of the special optical glass. The present invention preferably uses zirconium-reinforced Pt materials for the crucible and frame agitator for melting the mixture.

[0042] When the mixed material of the present invention is melted, the melting temperature is preferably 1300°C-1360°C and the time is 3h-5h. By limiting the temperature and time of high-temperature melting within a reasonable range, it can be ensured that each raw material is heated at high temperature to form a uniform, bubble-free glass liquid that meets the molding requirements, which is beneficial to subsequent processing and molding.

[0043] Preferably, stirring is performed using a frame stirrer at a speed of 30 rpm-50 rpm for 1 h-2 h; further limiting the type of stirrer, stirring speed and stirring time used in the high-temperature melting process is beneficial to improving the efficiency of high-temperature melting.

[0044] The preferred molding temperature is 1050°C-1100°C, and the preheating mold temperature is 300°C-350°C; by limiting the molding temperature and preheating mold temperature of the casting molding within a reasonable range, the casting molding efficiency can be improved.

[0045] The preferred annealing temperature is 500° C.-550° C., and the annealing time is 3 h-6 h. By limiting the annealing temperature and annealing time within a reasonable range, it is beneficial to better eliminate the stress in the special optical glass and improve its optical transparency and mechanical strength.

[0046] The special optical glass of the present invention is preferably prepared by the preparation method of the present invention.

[0047] The present invention also provides a lens, the material of which is the aforementioned special optical glass.

[0048] The present invention also proposes an application of the aforementioned lens in the field of virtual reality, digital camera, microscope, or vehicle-mounted display technology.

[0049] The present invention will be further described below in conjunction with specific embodiments, but this should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by technicians in this field based on the above-mentioned contents of the present invention still fall within the scope of protection of the present invention.

[0050] Unless otherwise specified, the materials, reagents, etc. involved below are all commercially available products well known to those skilled in the art; unless otherwise specified, the methods described are all methods well known in the art. Unless otherwise defined, the technical terms or scientific terms used should have the common meanings understood by ordinary technicians in the field to which the present invention belongs.

[0051] When the special optical glass components are prepared in the embodiment of the present invention, B 2 O 3 The components are converted according to the content of B element and boric acid is selected as the raw material; SiO 2 The components are converted according to the Si element content and quartz sand is selected as the raw material; Bi 2 O 3 , Ga 2 O 3 , Tb 2 O 3 ,BaO,La 2 O 3 , Nb 2 O 5 , HfO 2 The oxide itself can be directly used as the raw material, or the corresponding carbonate or nitrate can be selected as the raw material after conversion according to the content of each element.

[0052] The testing methods of various performance indicators in the embodiments of the present invention are as follows:

[0053] The refractive index is tested according to the method of GB / T 7962.1-2010 "Test methods for colorless optical glass Part 1: Refractive index and dispersion coefficient".

[0054] The internal transmittance is tested according to the method of GB / T 7962.12-2010 "Test methods for colorless optical glass Part 12: Spectral internal transmittance".

[0055] The water resistance stability is tested according to the method of GB / T6582-2021 "Particle test method and classification of water resistance of glass at 98°C".

[0056] Optical uniformity is tested according to the method of GB / T 7962.2-2010 "Test methods for colorless optical glass Part 2: Optical uniformity - Fizeau plane interferometry".

[0057] Example 1

[0058] Weigh the corresponding weight of raw materials according to the glass components in Table 1, and mix these raw materials evenly to obtain the batch material. Add the batch material balls into the zirconium-reinforced Pt crucible, melt at 1360°C for 5 hours under vacuum conditions, the furnace chamber pressure is 0.01Pa, and the glass liquid is mechanically stirred by a zirconium-reinforced Pt stirrer, the speed is 30rpm, and the stirring time is 2 hours. The zirconium content in the zirconium-reinforced Pt is 100ppm. The homogenized glass liquid is formed into a preheated mold by leaking material, the forming temperature is 1100°C, and the preheating mold temperature is 350°C. The formed glass is annealed at 550°C for 3 hours, and the annealing furnace power is turned off; finally, the high refractive index special optical glass is subjected to performance testing, and the test results are shown in Table 1.

[0059] Example 2

[0060] Weigh the corresponding weight of raw materials according to the glass components in Table 1, and mix these raw materials evenly to obtain the batch material. Add the batch material balls into the zirconium-reinforced Pt crucible, melt at 1300℃ for 4h under vacuum conditions, the furnace chamber pressure is 0.001Pa, and the glass liquid is mechanically stirred by a zirconium-reinforced Pt stirrer, the speed is 50rpm, and the stirring time is 2h. The zirconium content in the zirconium-reinforced Pt is 250ppm. The homogenized glass liquid is formed into a preheated mold by leaking material, the forming temperature is 1050℃, and the preheating mold temperature is 320℃. The formed glass is annealed at 530℃ for 5h, and the annealing furnace power is turned off; finally, the high refractive index special optical glass is tested for performance, and the test results are shown in Table 1.

[0061] Example 3

[0062] Weigh the corresponding weight of raw materials according to the glass components in Table 1, and mix these raw materials evenly to obtain the batch material. Add the batch material balls into the zirconium-reinforced Pt crucible, melt at 1330°C for 3 hours under vacuum conditions, the furnace chamber pressure is 0.018Pa, and the glass liquid is mechanically stirred by a zirconium-reinforced Pt stirrer, the speed is 40rpm, and the stirring time is 1 hour. The zirconium content in the zirconium-reinforced Pt is 400ppm. The homogenized glass liquid is formed into a preheated mold by leaking material, the forming temperature is 1100°C, and the preheating mold temperature is 300°C. The formed glass is annealed at 500°C for 6 hours, and the annealing furnace power is turned off; finally, the high refractive index special optical glass is subjected to performance testing, and the test results are shown in Table 1.

[0063] Example 4

[0064] Weigh the corresponding weight of raw materials according to the glass components in Table 1, and mix these raw materials evenly to obtain the batch material. Add the batch material balls into the zirconium-reinforced Pt crucible, melt at 1320°C for 3 hours under vacuum conditions, the furnace chamber pressure is 0.05Pa, and the glass liquid is mechanically stirred by a zirconium-reinforced Pt stirrer, the speed is 30rpm, and the stirring time is 2 hours. The zirconium content in the zirconium-reinforced Pt is 550ppm. The homogenized glass liquid is formed into a preheated mold by leaking material, the forming temperature is 1080°C, and the preheating mold temperature is 300°C. The formed glass is annealed at 520°C for 6 hours, and the annealing furnace power is turned off; finally, the high refractive index special optical glass is subjected to performance testing, and the test results are shown in Table 1.

[0065] Example 5

[0066] Weigh the corresponding weight of raw materials according to the glass components in Table 1, and mix these raw materials evenly to obtain the batch material. Add the batch material balls into the zirconium-reinforced Pt crucible, melt at 1350°C for 4 hours under vacuum conditions, the furnace chamber pressure is 0.01Pa, and the glass liquid is mechanically stirred by a zirconium-reinforced Pt stirrer, the speed is 50rpm, and the stirring time is 1 hour. The zirconium content in the zirconium-reinforced Pt is 700ppm. The homogenized glass liquid is formed into a preheated mold by leaking material, the forming temperature is 1080°C, and the preheating mold temperature is 330°C. The formed glass is annealed at 530°C for 5 hours, and the annealing furnace power is turned off; finally, the high refractive index special optical glass is subjected to performance testing, and the test results are shown in Table 1.

[0067] Example 6

[0068] Weigh the corresponding weight of raw materials according to the glass components in Table 1, and mix these raw materials evenly to obtain the batch material. Add the batch material balls into the zirconium-reinforced Pt crucible, melt at 1310°C for 5 hours under vacuum conditions, the furnace chamber pressure is 0.08Pa, and the glass liquid is mechanically stirred with a zirconium-reinforced Pt stirrer at a speed of 30rpm and a stirring time of 2 hours. The zirconium content in the zirconium-reinforced Pt is 850ppm. The homogenized glass liquid is formed into a preheated mold by leaking material, the forming temperature is 1100°C, and the preheating mold temperature is 300°C. The formed glass is annealed at 500°C for 6 hours, and the annealing furnace power is turned off; finally, the high refractive index special optical glass is subjected to performance testing, and the test results are shown in Table 1.

[0069] Example 7

[0070] Weigh the corresponding weight of raw materials according to the glass components in Table 1, and mix these raw materials evenly to obtain the batch material. Add the batch material balls into the zirconium-reinforced Pt crucible, melt at 1350°C for 4 hours under vacuum conditions, the furnace chamber pressure is 0.06Pa, and the glass liquid is mechanically stirred by a zirconium-reinforced Pt stirrer, the speed is 50rpm, and the stirring time is 2 hours. The zirconium content in the zirconium-reinforced Pt is 1000ppm. The homogenized glass liquid is formed into a preheated mold by leaking material, the forming temperature is 1075°C, and the preheating mold temperature is 350°C. The formed glass is annealed at 500°C for 3 hours, and the annealing furnace power is turned off; finally, the high refractive index special optical glass is subjected to performance testing, and the test results are shown in Table 1.

[0071] Example 8

[0072] Same as Example 7. The difference is that the crucible and stirrer used are made of pure platinum. The test results are shown in Table 1.

[0073] Comparative Example 1

[0074] The corresponding weights of raw materials were weighed according to the glass components in Table 1. The glass preparation method was the same as that in Example 7. The test results are shown in Table 1 for details.

[0075] Comparative Example 2

[0076] The corresponding weights of raw materials were weighed according to the glass components in Table 1. The glass preparation method was the same as that in Example 7. The test results are shown in Table 1 for details.

[0077] Comparative Example 3

[0078] According to the glass components in Table 1, corresponding weights of raw materials were weighed, and the glass preparation method was the same as in Example 7. The difference was that during the glass preparation process, melting was carried out under atmospheric environment. The test results are shown in Table 1.

[0079] Comparative Example 4

[0080] According to the glass components in Table 1, corresponding weights of raw materials are weighed. The glass formula and preparation method are the same as those in Example 7. The difference is that during the glass preparation process, the melting vacuum degree is 0.5 Pa. The test results are shown in Table 1.

[0081] Comparative Example 5

[0082] The corresponding weights of raw materials were weighed according to the glass components in Table 1. The glass preparation method was the same as that in Example 7. The test results are shown in Table 1 for details.

[0083] Comparative Example 6

[0084] The corresponding weights of raw materials were weighed according to the glass components in Table 1. The glass formula and preparation method were the same as those in Example 7. The difference was that a corundum crucible and a corundum stirrer were used in the glass preparation process. The test results are shown in Table 1.

[0085] Table 1 Composition and performance test results of special optical glass in various embodiments and comparative examples

[0086]

[0087]

[0088] In Table 1, the content of each component is weight percentage, unit %; the wavelength of the refractive index test is 587.6nm; the wavelength of the internal transmittance test is 440nm, unit %; the unit of water resistance stability is level; the optical uniformity is ×10 -6 The numerical value of .

[0089] It can be seen from the test data shown in Table 1 that the special optical glass prepared in all embodiments of the present invention has a high refractive index (≥2.0), good internal transmittance (transmittance at 440nm ≥94%), excellent chemical stability (grade 1) and good optical uniformity (better than 3×10 -5 ), the comprehensive performance of special optical glass is excellent.

[0090] It can be seen from the test data shown in Table 1 that the raw material composition ratio of the special optical glasses of Comparative Examples 1, 2, and 5 does not conform to the technical solution of the present invention, and the prepared special optical glasses have poor performance; specifically, Bi in Comparative Example 1 2 O 3 The content is relatively high. Although the refractive index of the special optical glass prepared by this ratio is high, its chemical stability is poor, which is level 3. 2 O 3 The content is low, and the refractive index of the special optical glass prepared by this ratio is low. d <2.0; Ga in Comparative Example 5 2 O 5 and HfO2 The content is on the low side, and the water resistance stability of the special optical glass prepared by this ratio becomes poor, and the water resistance grade is 3.

[0091] It can be seen from the test data shown in Table 1 that the preparation processes of the special optical glasses of Comparative Examples 3, 4, and 6 do not conform to the technical solution of the present invention, and the prepared special optical glasses have poor performance; specifically, the melting process of the special optical glass of Comparative Example 3 is carried out under an atmospheric environment, resulting in the impurity Fe ions in the glass being in a high-valent state Fe 3+ The glass is colored more and the internal transmittance is poor. The special optical glass of Comparative Example 4 is melted in a low vacuum environment, and the Fe ions in the glass are still mainly Fe 3+ The special optical glass of Example 6 adopts a corundum crucible and a stirrer, which are greatly corroded by the high-temperature glass liquid, resulting in the introduction of unwanted ions into the glass liquid, which deteriorates the light transmittance and optical uniformity of the glass.

[0092] From the test data shown in Table 1, it can be seen that the optical uniformity of the crucibles and stirrers made of zirconium-reinforced platinum in Examples 1 to 7 is very good; the optical uniformity of the crucible and stirrer made of pure platinum in Example 8 is 2.5×10 -5 , and the results are also good, but from the test data of optical uniformity, the use of zirconium-reinforced platinum can further improve the optical uniformity of special optical glass.

[0093] The technical features in the claims and / or the specification of the present invention may be combined, and the combination is not limited to the combination obtained by reference in the claims. The technical solution obtained by combining the technical features in the claims and / or the specification is also within the protection scope of the present invention.

[0094] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A preparation method of a special optical glass, characterized in that, it comprises the following steps: 1) Weigh the raw materials according to the component ratio of the special optical glass and mix them evenly; by weight percentage, the components of the special optical glass are: Bi 2 O 3 : 30% - 40%; Ga 2 O 3 : 20% - 30%; B 2 O 3 : 15% - 25%; Tb 2 O 3 : 2% - 8%; BaO: 2% - 6%; La 2 O 3 : 1% - 5%; Nb 2 O 5 : 1% - 5%; HfO 2 : 1% - 5%; SiO 2 : 0% - 5%; and the impurity iron element introduced in the raw materials; 2) Melting the mixture into a glass melt under a vacuum condition with a pressure ≤ 0.01 Pa, clarifying and homogenizing the glass melt under stirring conditions, forming, and annealing to obtain the special optical glass; wherein, the container and stirrer in contact with the glass melt during the melting process are made of Pt material.

2. The preparation method according to claim 1, characterized in that, The components of the special optical glass include: Bi 2 O 3 : 35% - 40%; Ga 2 O 3 : 20% - 25%; B 2 O 3 : 15% - 20%; Tb 2 O 3 : 2% - 5%; BaO: 4% - 6%; La 2 O 3 : 1% - 3%; Nb 2 O 5 : 1% - 3%; HfO 2 : 1% - 3%; SiO 2 : 3% - 5%.

3. The preparation method according to claim 1, characterized in that, the range of the pressure is 0.001 Pa to 0.01 Pa.

4. The preparation method according to claim 1, characterized in that, the Pt material is zirconium-reinforced Pt, and the zirconia content is 100 to 1000 ppm.

5. The preparation method according to claim 1, characterized in that, the temperature of the melting is 1300 °C - 1360 °C, and the time is 3 h - 5 h; the stirring is carried out by a frame stirrer, the rotation speed is 30 rpm - 50 rpm, and the time is 1 h - 2 h; the temperature of the forming is 1050 °C - 1100 °C, and the preheating temperature of the mold is 300 °C - 350 °C; the temperature of the annealing is 500 °C - 550 °C, and the annealing time is 3 h - 6 h.

6. A special optical glass prepared by the preparation method according to any one of claims 1 to 5, characterized in that, Its refractive index n d ≥2.0, the internal transmittance at 440 nm ≥ 94%, the water resistance stability is better than grade 1, and the optical uniformity is better than 3×10 -5 .

7. A lens, characterized in that, its material is the special optical glass according to claim 6.

8. An application of the lens according to claim 7 in the fields of virtual reality, digital cameras, microscopes or in-vehicle display technologies.

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