Fluorophosphate optical glass, method for producing the same, and optical element

Abstract

The present application provides a kind of fluorophosphate optical glass and its preparation method and optical element.Fluorophosphate optical glass includes the following components by compound: Al (PO3) 3:5-12%; AlF3:22-33%; BaF2:7.5-15%; SrF2:20-30%; CaF2:20-30%; MgF2:2-7%; YF3:0.5-8%; LiF:0.05-0.45%; the above percentage is mass percentage; the refractive index n of the fluorophosphate optical glass d It is 1.43-1.46, and the Abbe number υ d It is 90-100.The fluorophosphate optical glass of the present application is high enough in internal transmittance in the visible light range.Moreover, the fluorophosphate glass of the present application not only has low cost, but also has good chemical stability, coloration degree; the glass transition temperature is relatively low, which is beneficial to precision mold forming.

Description

Technical Field

[0001] This invention relates to a fluorophosphate optical glass, its preparation method, and optical components, belonging to the field of optical glass. Background Technology

[0002] Low-refractive-index, low-dispersion fluorophosphate optical glass, due to its superior properties of low dispersion and elimination of secondary spectral dispersion, is widely used in lens modules of optical instruments for high-precision chromatic aberration correction, and has become an indispensable component material in related optical designs. In recent years, with the rapid development of digitalization and high precision in optical equipment, imaging pixels have been increasing, thus demanding higher resolution.

[0003] The optical glasses disclosed in patent applications CN102745899A and CN1931761A both contain more than 5% P. 5+ However, excessive introduction of P 5+ This will inevitably introduce a large number of O 2- This leads to increased dispersion, making it impossible to obtain a lower dispersion value.

[0004] Patent application CN102674689A discloses a fluorophosphate optical glass, wherein Zn 2+ The content is 0.5-15%, Zn 2+ With a large ionic radius, excessive introduction of Zn 2+ This will disrupt the glass's network structure, reducing its crystallization properties, chemical stability, and colorfastness. Furthermore, introducing Zn(PO3)2 into Zn... 2+ This will inevitably introduce a large number of O 2- This leads to increased dispersion, making it impossible to obtain a lower dispersion value.

[0005] The fluorophosphate optical glass disclosed in patent application CN101544468B, wherein O 2- / P 5+ The molar ratio is greater than 3.5, introducing more O. 2- This leads to increased dispersion, making it impossible to obtain a lower dispersion value. In this invention, O... 2- / P 5+ The molar ratio is 3.

[0006] Patent application CN106904831A discloses a fluorophosphate optical glass containing 0.5% to 8% LiF. Because Li... + The radius is small, and too much Li + This will cause a sharp decline in the alkali resistance of the glass, a worsening of its abrasion resistance, which will seriously affect the subsequent processing and coating of optical glass lenses. At the same time, the crystallization performance will deteriorate, and the streaks caused by crystallization during the melting process will be severe, greatly reducing the yield of the glass. SUMMARY

[0007] Problems to be solved by the invention

[0008] The present application provides a fluorophosphate optical glass, a preparation method thereof and an optical element. The fluorophosphate optical glass has a refractive index n d of 1.43-1.46, an Abbe number υ d of 90-100. The fluorophosphate optical glass has good chemical stability, high visible light transmittance and low glass transition temperature, and can eliminate the defects of high melting temperature and difficult control of volatile streaks of existing optical glasses.

[0009] Further, the present application also provides a preparation method of the fluorophosphate optical glass, which is simple and easy to operate, raw materials are easy to obtain, and stable batch production can be realized.

[0010] Solution to the problem

[0011] The present application provides a fluorophosphate optical glass, which comprises the following components in terms of compounds:

[0012] Al(PO3)3: 5%-12%, preferably 6%-10%;

[0013] AlF3: 22%-33%, preferably 23%-30%;

[0014] BaF2: 7.5%-15%, preferably 9%-13%;

[0015] SrF2: 20%-30%, preferably 22%-29%;

[0016] CaF2: 20%-30%, preferably 22%-28%;

[0017] MgF2: 2%-7%, preferably 2%-5%;

[0018] YF3: 0.5%-8%, preferably 0.5%-6%;

[0019] LiF: 0.05%-0.45%, preferably 0.1%-0.35%;

[0020] The above percentages are mass percentages;

[0021] The fluorophosphate optical glass has a refractive index n d of 1.43-1.46, an Abbe number υ d of 90-100.

[0022] The fluoro phosphate optical glass according to the present application, wherein the ratio BaF2 / CaF2 of the content of BaF2 to the content of CaF2 is 0.35 to 0.72, preferably 0.36 to 0.64, in terms of weight percentage; and / or, the ratio BaF2 / (MgF2+CaF2) of the content of BaF2 to the sum of the contents of MgF2 and CaF2 is 0.3 to 0.64, preferably 0.32 to 0.56; and / or,

[0023] The ratio Al(PO3)3 / LiF of the content of Al(PO3)3 to the content of LiF is 13 to 180, preferably 13 to 150.

[0024] The fluoro phosphate optical glass according to the present application, wherein the fluoro phosphate optical glass does not contain at least one of P2O5, NaF, KF, SnF4, La2O3, Gd2O3, Y2O3, Yb2O3, Ta2O5, GeO2, CaO, BaO, SrO and MgO in the composition thereof.

[0025] The fluoro phosphate optical glass according to the present application, wherein the fluoro phosphate optical glass has a crystallization upper limit temperature L t of 680°C or lower, a glass transition temperature T g of 440°C or lower; and / or,

[0026] The fluoro phosphate optical glass has a devitrification resistance T g / L t of more than 0.64.

[0027] The fluoro phosphate optical glass according to the present application, wherein the fluoro phosphate optical glass has a coloration degree λ 80 / λ5 in which λ 80 is 310 nm or lower and λ5 is 190 nm or lower.

[0028] The fluoro phosphate optical glass according to the present application, wherein the fluoro phosphate optical glass has a specific gravity of 3.80 g / cm 3 or more.

[0029] The fluoro phosphate optical glass according to the present application, wherein the fluoro phosphate optical glass has an alkali resistance R OH (S) of 4 or more; and / or

[0030] The fluoro phosphate optical glass has an abrasion degree F A of 455 or less.

[0031] The application further provides a preparation method of the fluorophosphate optical glass, which comprises the following steps: weighing and mixing components according to proportions, melting after uniform mixing, and making volatile gas sufficiently escape during the melting process; preferably, the temperature of the melting is 800-900 DEG C; then pouring or pouring into a forming mold, or directly pressing into shape.

[0032] According to the preparation method, after the melting, the temperature is increased to 900-1000 DEG C under a closed environment, and a stirrer is started to stir for 3-8 h; after the stirring is completed, the temperature is increased to 1000-1050 DEG C and kept for 4-9 h to clarify, so that bubbles are sufficiently floated up, and then the temperature is decreased to 600-700 DEG C.

[0033] The application further provides an optical element comprising the fluorophosphate optical glass.

[0034] Effects of the application

[0035] The fluorophosphate optical glass has high internal transmittance in the visible light range. Moreover, the fluorophosphate glass has low cost, good chemical stability, coloring degree, low glass transition temperature, low specific gravity, excellent achromatic performance, low crystallization temperature, and the like.

[0036] Further, the preparation method of the fluorophosphate optical glass is simple and easy to implement, raw materials are easy to obtain, and the method is suitable for mass production. DETAILED DESCRIPTION

[0037] Various exemplary embodiments, features, and aspects of the present application will be described in detail below. The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations.

[0038] In addition, in order to better illustrate the present application, numerous specific details are given in the following detailed description. Those skilled in the art should understand that the present application can be implemented without some specific details. In some other examples, methods, means, apparatuses and steps that are well known to those skilled in the art are not described in detail, so as to highlight the main idea of the present application.

[0039] Unless otherwise specified, the units used in the specification are international standard units, and the numerical values and numerical ranges appearing in the present application should be understood as including systematic errors that are inevitable in industrial production.

[0040] In the present specification, the meaning indicated by use of "may" includes both the meaning of performing a certain process and the meaning of not performing a certain process.

[0041] In the present specification, reference to "some specific / preferred embodiments", "other specific / preferred embodiments", "embodiments", and the like indicates that a particular element (e.g., feature, structure, property, and / or characteristic) described is included in at least one embodiment of what is described herein, and can or can not be present in other embodiments. In addition, it is to be understood that the described elements can be combined in any suitable manner in various embodiments.

[0042] In the present specification, a numerical range indicated by use of "numerical value A to numerical value B" indicates a range including the end point numerical values A, B.

[0043] In the present specification, when "ordinary temperature" or "room temperature" is used, the temperature can be 10 to 40°C.

[0044] The present application first provides an optical glass comprising, in terms of compounds:

[0045] Al(PO3)3: 5 to 12%, preferably 6 to 10%;

[0046] AlF3: 22 to 33%, preferably 23 to 30%;

[0047] BaF2: 7.5 to 15%, preferably 9 to 13%;

[0048] SrF2: 20 to 30%, preferably 22 to 29%;

[0049] CaF2: 20 to 30%, preferably 22 to 28%;

[0050] MgF2: 2 to 7%, preferably 2 to 5%;

[0051] YF3: 0.5 to 8%, preferably 0.5 to 6%;

[0052] LiF: 0.05 to 0.45%, preferably 0.1 to 0.35%;

[0053] The above percentages are mass percentages;

[0054] The fluorophosphate optical glass has a refractive index n d of 1.43 to 1.46, and an Abbe number υ d of 90 to 100.

[0055] The raw material introduction method is in a form capable of introducing the respective contents of the compounds. In the following description, the contents of the components are expressed in mass percent.

[0056] Al(PO3)3 is a necessary component for introducing Al, P, and O into the glass. Al, P, and O are main elements constituting the glass network, and can promote the formation of stable glass and improve the mechanical properties and chemical durability of the glass. When the content of Al(PO3)3 is less than 5%, the tendency of the glass to crystallize increases, and the mechanical properties and stability deteriorate, while when the content of Al(PO3)3 is more than 12%, the refractive index and dispersion increase, and a low-refractive, low-dispersion optical glass cannot be obtained. Therefore, the content of Al(PO3)3 can be controlled to be 5% to 12%, and preferably 6% to 10%.

[0057] The two elements (aluminum and fluorine) introduced by AlF3 are also components constituting the glass network, and the fluorine element is also a key component for reducing the dispersion of the product and increasing the Abbe number υ d . AlF3 is effective for improving the devitrification resistance and chemical stability of the glass, and is also important for improving the mechanical properties and linear expansion coefficient of the glass. In the glass system of the present application, when the content of AlF3 is less than 22%, it is difficult to achieve the goal of increasing the Abbe number υ d , i.e., it is difficult to achieve the matching relationship of n d , υ d . When the content of AlF3 is more than 33%, the transition temperature Tg of the glass increases significantly, causing the molding temperature to increase, and in addition, an excessive amount of AlF3 increases the tendency of the glass to become cloudy, increases the brittleness, and increases the degree of wear. Therefore, the content of AlF3 is 22% to 33%, and preferably 23% to 30%.

[0058] BaF2 can effectively adjust the refractive index of the glass and improve the crystallization properties of the glass. When the content of BaF2 is less than 7.5%, these effects cannot be sufficiently achieved. When the content of BaF2 is more than 15%, the refractive index of the glass becomes excessively large, it is difficult to achieve the intended optical properties, and the chemical stability of the glass also decreases. In the present application, the content of BaF2 can be controlled to be 7.5% to 15%, and preferably 9% to 13%.

[0059] CaF2 can reduce the dispersion of the glass and improve the stability of the glass. When the content of CaF2 is less than 20%, these effects cannot be sufficiently achieved. When the content of CaF2 is more than 30%, the glass cannot sufficiently achieve the intended optical properties, and the chemical stability of the glass also decreases, and the tendency of the glass to crystallize increases. In the present application, the content of CaF2 can be controlled to be 20% to 30%, and preferably 22% to 28%.

[0060] Further, the inventors have found that when the ratio BaF2 / CaF2 is too low, the anti-crystallization ability and chemical stability of the glass decrease; when the ratio BaF2 / CaF2 is too high, the specific gravity of the glass increases, and it is difficult to achieve the purpose of light weight. Therefore, in the present application, the ratio BaF2 / CaF2 is limited to 0.35-0.72, preferably 0.36-0.64.

[0061] SrF2 can effectively adjust the refractive index of the glass and improve the crystallization performance of the glass. When the content of SrF2 is less than 20%, these effects cannot be fully achieved. When the content of SrF2 is higher than 30%, the glass cannot fully achieve the desired optical properties, and the chemical stability of the glass is also reduced. In the present application, the content of SrF2 can be controlled to be 20%-30%, preferably 22%-29%.

[0062] MgF2 is added as an optional component in the present application. MgF2 can reduce the dispersion and refractive index of the glass, and can improve the chemical stability of the glass. When the content of MgF2 is less than 2%, it is not possible to form low dispersion and refractive index. However, when the content of MgF2 is higher than 7%, the crystallization performance of the glass deteriorates. Therefore, in the present application, the amount of MgF2 can be controlled to be 2%-7%, preferably 2%-5%.

[0063] Further, the inventors have found that the value of BaF2 / (CaF2+MgF2) is closely related to the crystallization performance, chemical stability, etc. of the glass. When the value of BaF2 / (CaF2+MgF2) is too low, the anti-crystallization performance of the glass becomes poor, and the chemical stability also becomes poor; when the value of BaF2 / (CaF2+MgF2) is too high, the specific gravity of the glass increases, and the dispersion of the glass increases, and it is not possible to form low dispersion. Therefore, in the present application, the value of BaF2 / (CaF2+MgF2) is limited to 0.3-0.64, preferably 0.32-0.56.

[0064] YF3 is beneficial for adjusting the optical properties such as refractive index and dispersion of the glass, and can significantly improve the chemical stability of the glass, increase the forming viscosity of the glass, and is beneficial for the forming of the glass. However, if it is introduced in excess, the anti-crystallization performance of the glass decreases, the refractive index and dispersion increase substantially, and it is not possible to achieve the desired optical properties. Therefore, in the present application, the amount of YF3 can be controlled to be 0.5%-8%, preferably 0.5%-6%.

[0065] The inventors have found that LiF can reduce the surface tension during the melting process of the glass, and effectively eliminate the problem of bubbles in fluorophosphorus glass, so LiF is a necessary component in the present application. However, when the content of LiF exceeds 0.45%, LiF will react with other components in the glass, and the chemical stability of the glass will be reduced. Therefore, in the present application, the content of LiF is limited to 0.1%-0.45%, preferably 0.1%-0.35%. +The chemical stability of the glass will decrease, the crystallization performance of the glass will become poor, and the abrasion degree will increase. Therefore, in the present application, the amount of LiF can be controlled between 0.05% and 0.45%, preferably between 0.1% and 0.35%.

[0066] Further, the present inventors have found that the ratio of Al(PO3)3 / LiF is closely related to the crystallization performance of the glass. When the ratio of Al(PO3)3 / LiF is too low, the crystallization performance of the glass becomes poor; when the ratio of Al(PO3)3 / LiF is too high, the refractive index and dispersion will greatly increase, the effect of low refractive index and low dispersion cannot be achieved, and the bubbles and foreign matters in the melting process are difficult to eliminate. Therefore, in the present application, the ratio of Al(PO3)3 / LiF is controlled between 13 and 180, preferably between 13 and 150.

[0067] The content of fluorine (F) in the glass is effective for reducing the refractive index n d and dispersion of the glass. If the content of fluorine (F) is too low, the refractive index and dispersion tend to increase, and the target of low refractive index and low dispersion cannot be achieved. On the contrary, if the content of fluorine (F) is too high, the ionic bonds in the glass will increase, and the characteristics of small ionic bond energy will lead to instability of the glass framework, which will make the glass more likely to devitrify. In addition, too high content of fluorine (F) will increase the abrasion degree of the product, and the large abrasion degree value is not conducive to the tolerance control in the glass polishing process. In the present application, the fluorine (F) in the glass is introduced by adding AlF3, BaF2, CaF2, SrF2, MgF2 and LiF, and no other fluorides are artificially introduced in the present application.

[0068] The present application has found that the refractive index and dispersion of the fluorophosphate glass are related to the oxygen fluorine ratio (O / F) in the glass. The larger the oxygen fluorine ratio (O / F), i.e. the higher the oxygen content, the higher the refractive index and the larger the dispersion of the glass. In the present application, the content and ratio of the above oxides and fluorides are used to control the oxygen fluorine ratio (O / F) in the glass.

[0069] The content of hydroxyl (OH) in the glass is closely related to the alkali resistance of the glass. The hydroxyl in the glass will destroy the network structure of the glass, reduce the stability of the glass framework, and when the glass is eroded by an alkaline solution, the structure is more easily destroyed, which will greatly reduce the alkali resistance of the glass. Therefore, in the present application, the hydroxyl in the glass will be reduced as much as possible.

[0070] Further, the fluorophosphate optical glass of the present application does not contain at least one of P2O5, NaF, KF, SnF4, La2O3, Gd2O3, Y2O3, Yb2O3, Ta2O5, GeO2, CaO, BaO, SrO and MgO, preferably none of them.

[0071] In the present application, the crystallization upper limit temperature L t of the fluorophosphate optical glass is 680℃ or lower, the glass transition temperature T g is 440℃ or lower; and / or, the devitrification resistance T g of the fluorophosphate optical glass is greater than 0.64. The coloration degree λ t of the fluorophosphate optical glass is less than 0.64. The λ 80 in λ 80 / λ5 is 310nm or lower, and λ5 is 190nm or lower. The specific gravity of the fluorophosphate optical glass is 3.80g / cm 3 or lower. The alkali resistance R OH (S) of the fluorophosphate optical glass is grade 4 or higher; and the abrasion degree F A of the fluorophosphate optical glass is 455 or lower.

[0072] Further, the present application also provides a preparation method of the fluorophosphate optical glass according to the present application, characterized in that, comprising: weighing and mixing the components according to the proportion, then melting, and in the melting process, making the volatile gas sufficiently escape; preferably, the temperature of the melting is 800-900℃; then pouring or pouring in a forming mold, or directly pressing into shape.

[0073] In the present application, when the glass powder is just put into the crucible, a large amount of volatile matter will be produced due to the strong volatilization characteristics of the fluoride. Since the fluoride volatilizes a lot, the hydroxyl in the glass will be taken out in the form of H2O, which can greatly reduce the content of hydroxyl in the glass. Therefore, the optical glass manufacturing process of the present application needs to be treated in a way during the melting process, so that the volatile gas can sufficiently escape.

[0074] Further, after the melting, the temperature is raised to 900-1000℃ and the stirrer is started to stir, and the stirring time is controlled to be 3-8h; after the stirring is completed, the temperature is raised to 1000-1050℃ and kept for 4-9h for clarification, so that the bubbles can sufficiently float up, and then the temperature is reduced to 600-700℃.

[0075] Specifically, the melting is completed, and the sealing treatment needs to be performed during the stages of stirring, homogenization, clarification, and temperature reduction and discharging. At this time, the volatilization amount of the glass after the melting process is greatly reduced. If it is opened, the H2O in the air will again enter the glass liquid, increasing the content of hydroxyl. Therefore, the optical glass manufacturing process of the present application needs to be treated in a way during the stages of stirring, homogenization, clarification, and temperature reduction and discharging.

[0076] The fluorophosphate glass has strong volatility due to the large amount of fluorine contained therein. In order to reduce the optical unevenness (streaks) on the surface of the glass caused by the volatilization of fluorine and the pollution to the environment, preferably, in the production of the fluorophosphate glass, a cooling cover plate is provided on the upper surface of the glass liquid flowing through the forming mold, and an inert gas is introduced to the surface of the glass liquid through the cooling cover plate to cool the glass liquid as soon as possible. In addition, in order to prevent the glass from eroding the smelting crucible, preferably, the smelting is carried out in a non-reducing atmosphere, and specifically, oxygen can be introduced into the smelting crucible or an oxidizing bath can be provided.

[0077] In addition, the present application also provides an optical element comprising the fluorophosphate optical glass according to the present application. The optical element can be produced by one or two times of press forming of the fluorophosphate optical glass, and can be used in the optical system of various optical instruments.

[0078] The embodiments of the present application will be described in detail below with reference to the examples, but those skilled in the art will understand that the following examples are only used to illustrate the present application and should not be regarded as limiting the scope of the present application. The specific conditions not mentioned in the examples are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are not marked with the manufacturer, which are all conventional products that can be obtained by purchase.

[0079] The examples 1-20 in the table are typical experiments for obtaining the fluorophosphate optical glass with the refractive index n d of 1.43-1.46, the Abbe number υ d of 90-100 according to the present application.

[0080] Examples 1-20

[0081] Each component in the following Table 1, Table 2, Table 3 and Table 4 is calculated, weighed and mixed according to the specified proportion, and is put into a platinum-made crucible to be smelted at a temperature of 850°C. During the smelting process, the crucible is open to allow the gas to escape fully. After the raw materials are melted into a glass liquid, the temperature is increased to 950°C in a closed environment, and a platinum-made stirrer is started to stir and homogenize, and the stirring time is controlled to be 5h. After the stirring is completed, the temperature is increased to 1000°C and is kept for 6h for clarification, so that the bubbles can float up fully. Then, the temperature is decreased to 750°C to be cast or poured into a forming mold, and a cooling cover plate is provided on the forming mold as described above, and an inert gas is introduced to the surface of the glass liquid through the cooling cover plate to solve the volatilization streak problem caused by fluorine loss. Finally, the optical glass or optical element of examples 1-20 is obtained after annealing and processing.

[0082] Comparative examples A-C

[0083] The raw materials corresponding to the components in Table 4 below were weighed according to the specified proportions and prepared using the same preparation method as in Examples 1 to 20 to obtain optical glasses of Comparative Examples A, B, and C.

[0084] Comparative Example D

[0085] The raw materials corresponding to the components of Example 1 were weighed in the prescribed proportions. The difference between Comparative Example D and Example 1 is that the melting process was sealed, and the crucible was opened during the stirring, homogenization, clarification, and cooling stages after melting. Otherwise, they were completely the same.

[0086] Comparative Example E

[0087] The raw materials corresponding to the components of Example 1 were weighed in the prescribed proportions. The difference between Comparative Example E and Example 1 is that the melting process was sealed, and after the melting was completed, the stirring, homogenization, clarification, and cooling and unloading stages were also sealed. The rest were exactly the same.

[0088] Performance tests

[0089] The properties of the obtained fluorophosphate optical glass were measured using the following methods.

[0090] The refractive index nd and Abbe number υd of the fluorophosphate optical glass were measured according to the test method of GB / T7962.1-2010.

[0091] The short-wavelength transmission spectral characteristics of optical glass are expressed using colorimetric λ. 80 / λ5 represents λ. 80 λ5 refers to the wavelength corresponding to a spectral transmittance of 80%, while λ6 refers to the wavelength corresponding to a spectral transmittance of 5%. The light transmittance of glass with a thickness of 10 ± 0.1 mm, ground on parallel surfaces, was measured according to the "Method for Determining the Colorimetric Value of Optical Glass" (JOGIS02-2003) of the Japan Glass Industry Association. It should be noted that, since the lower limit of λ5 measurement is 190 nm, all λ5 measurement results are below 190 nm.

[0092] According to the test method of GB / T7962.12-2010, the internal transmittance (τ) at wavelengths of 700nm, 400nm, and 300nm was measured. 10 The sample thickness was 10±0.1 mm.

[0093] The specific gravity of the obtained optical glass was tested according to the test method of GB / T7962.20-2010.

[0094] The transition temperature T of the obtained optical glass was determined according to the test method of GB / T7962.16-2010. g Conduct the test.

[0095] L t The liquidus temperature, i.e. the upper limit of crystallization temperature, is tested by using the DTA (differential thermal analysis) method, and the temperature corresponding to the highest heat absorption peak in the DTA curve is the L t .

[0096] The abrasion degree F A of the obtained optical glass is tested according to the test method of GB / T 7962.19-2010.

[0097] The alkali resistance stability of the optical glass is represented by R OH (S), and the test is that a sample with a six-side polished size of 40mm x 40mm x 5mm is immersed in a sodium hydroxide solution with sufficient stirring, a constant temperature of 50℃±3℃ and a concentration of 0.01mol / L for 15 hours.

[0098] The hydroxyl content in the glass cannot be quantitatively tested, but the hydroxyl has a significant absorption peak at the 3000nm waveband, so in the present application, the content of the hydroxyl in the glass is represented by testing the 3000nm transmittance of the glass. According to the test method of GB / T 7962.12-2010, the internal transmittance (τ 10 at the 3000nm position is determined, and the sample thickness is 10±0.1mm.

[0099] Table 1 Glass components and performance parameters of examples 1-6

[0100]

[0101] Table 2 Glass components and performance parameters of examples 7-12

[0102]

[0103] Table 3 Glass components and performance parameters of examples 13-18

[0104]

[0105] Table 4 Glass components and performance parameters of examples 19-20 and comparative examples A, B, C

[0106]

[0107] Table 5 Performance parameters of examples 1 and comparative examples D, E

[0108]

[0109] As can be seen from Examples 1-20, the present invention preferably uses P2O5 introduced in the form of Al(PO3)3, which has the advantage of significantly reducing the number of production anomalies and making product performance more stable and controllable. When achieving the same expected optical constants, the glass of the examples exhibits higher chemical stability and a lower glass transition temperature than the comparative example. The lower glass transition temperature indicates that the product is more suitable for precision molding.

[0110] In Comparative Example A, when the LiF content is higher than 0.45%, R OH A sharp increase in (S) value leads to increased leaching quality, decreased alkali resistance, and reduced chemical stability of the glass. g / L t As the value decreases, the crystallization properties of the glass also deteriorate. Simultaneously, the abrasion degree F... A This also increases the difficulty of tolerance control during the glass grinding and polishing process.

[0111] In Comparative Example B, the BaF2 content was less than 7.5%, resulting in a BaF2 / (CaF2+MgF2) ratio of less than 0.3, and thus, alkali resistance D. A Level 5, D A The significantly increased leaching quality indicates a severe deterioration in the chemical stability of the glass. g A decrease in the / Lt value indicates a deterioration in the crystallization properties of the glass, which is detrimental to glass forming and also worsens the abrasion resistance.

[0112] In Comparative Example C, the Al(PO3)3 / LiF ratio was too low. All other components were within the limits of this invention, including nd, vd, alkali resistance, abrasion resistance, and specific gravity. However, due to the Al(PO3)3 / LiF ratio being lower than 13, the crystallization performance deteriorated.

[0113] As can be seen from Table 5, the preparation methods of Comparative Examples D and E are different from those of Example 1. The glass in Comparative Examples D and E has a higher hydroxyl content and a lower transmittance in the 3000nm band, resulting in poorer alkali resistance. The glass prepared by the method in Example 1 has a lower hydroxyl content, higher transmittance in the 3000nm band, and improved alkali resistance.

[0114] It should be noted that although the technical solution of the present invention has been described with specific examples, those skilled in the art will understand that the present invention should not be limited thereto.

[0115] Having described various embodiments of the application, it is to be understood that the above description is meant not to limit and not to encompass all of the possible embodiments covered by the claims. Many modifications and variations of this application can be apparent to those of ordinary skill in the art without departing from the spirit and scope of the described embodiments. It is intended that the scope of the application should only be limited by the appended claims.

Claims

1. A fluorophosphate optical glass, characterized by, It consists of the following components by weight: Al(PO3)3: 5%~12%; AlF3: 22%~33%; BaF2: 7.5%~15%; SrF2: 20%~30%; CaF2: 25.17%~30%; MgF2: 2%~7%; YF3: 0.5%~8%; LiF: 0.05%~0.45%; The ratio of the content of Al(PO3)3 to the content of LiF, Al(PO3)3 / LiF, is 13~180; the above percentages are all mass percentages; The refractive index n of the fluorophosphate optical glass d The Abbe number is υ, ranging from 1.43 to 1.

46. d It is 90~100.

2. The fluorophosphate optical glass according to claim 1, characterized by It consists of the following components by weight: Al(PO3)3: 5%~12%; AlF3: 22%~33%; BaF2: 7.5%~15%; SrF2: 20%~30%; CaF2: 25.17%~30%; MgF2: 2%~7%; YF3: 0.5%~8%; LiF: 0.05%~0.45%; 3. The fluorophosphate optical glass according to claim 1 or 2, characterized by The ratio of the content of Al(PO3)3 to the content of LiF, Al(PO3)3 / LiF, is 13~180; the above percentages are all mass percentages; It consists of the following components by weight:

4. The optical glass according to claim 3, characterized by Al(PO3)3: 5%~12%; AlF3: 22%~33%; BaF2: 7.5%~15%; 5. The fluorophosphate optical glass according to claim 1 or 2, characterized by The crystallization upper limit temperature L of the fluorophosphate optical glass t is 680°C or lower, the glass transition temperature T g is 440°C or lower; and / or, The fluorophosphate optical glass has a resistance to devitrification T g / L t greater than 0.

64.

6. The fluorophosphate optical glass according to claim 1 or 2, characterized by The degree of coloring λ of the fluorophosphate optical glass 80 λ in λ5 80 is 310 nm or less, and λ5 is 190 nm or less.

7. The fluorophosphate optical glass according to claim 1 or 2, characterized by The fluorophosphate optical glass has a specific gravity of 3.80 g / cm 3 The following.

8. The fluorophosphate optical glass according to claim 1 or 2, characterized by The alkali resistance R of the fluorophosphate optical glass OH (S) is 4 or more; and / or The degree of abrasion F of the fluorophosphate optical glass A is 455 or less.

9. A method of producing a fluorophosphate optical glass according to any one of claims 1 to 8, characterized by, SrF2: 20%~30%; CaF2: 25.17%~30%; 10. The method of claim 9, wherein, MgF2: 2%~7%; 11. The production method according to claim 9 or 10, characterized by, YF3: 0.5%~8%; 12. An optical element, characterized by, LiF: 0.05%~0.45%; The ratio of the content of Al(PO3)3 to the content of LiF, Al(PO3)3 / LiF, is 13~180; the above percentages are all mass percentages; It consists of the following components by weight: Al(PO3)3: 5%~12%; AlF3: 22%~33%; BaF2: 7.5%~15%; SrF2: 20%~30%; CaF2: 25.17%~30%; MgF2: 2%~7%; YF3: 0.5%~8%; LiF: 0.05%~0.45%; The ratio of the content of Al(PO3)3 to the content of LiF, Al(PO3)3 / LiF, is 13~180; the above percentages are all mass percentages; It consists of the following components by weight: Al(PO3)3: 5%~12%; AlF3: 22%~33%; BaF2: 7.5%~15%; SrF2: 20%~30%; CaF2: 25.17%~30%; MgF2: 2%~7%; YF3: 0.5%~8%; LiF: 0.05%~0.45%; The ratio of the content of Al(PO3)3 to the content of LiF, Al(PO3)3 / LiF, is 13~180; the above percentages are all mass percentages; It consists of the following components by weight: Al(PO3)3: 5%~12%; AlF3: 22%~33%; BaF2: 7.5%~15%; SrF2: 20%~30%; CaF2: 25.17%~30%; MgF2: 2%~7%; YF3: 0.5%~8%; LiF: 0.05%~0.45%; The ratio of the content of Al(PO3)3 to the content of LiF, Al(PO3)3 / LiF, is 13~180; the above percentages are all mass percentages; It consists of the following components by weight: Al(PO3)3: 5%~12%; AlF3: 22%~33%; BaF2: 7.5%~15%; SrF2: 20%~30%; CaF2: 25.17%~30%; MgF2: 2%~7%; YF3: 0.5%~8%; LiF: 0.05%~0.45%; The ratio of the content of Al(PO3)3 to the content of LiF, Al(PO3)3 / LiF, is 13~180; the above percentages are all mass percentages; It consists of the following components by weight: Al(PO3)3: 5%~12%; AlF3: 22%~33%; BaF2: 7.5%~15%; SrF2: 20%~30%; CaF2: 25.17%~30%; MgF2: 2%~7%; YF3: 0.5%~8%; LiF: 0.05%~0.45%; The ratio of the content of Al(PO3)3 to the content of LiF, Al(PO3)3 / LiF, is 13~180; the above percentages are all mass percentages; It consists of the following components by weight: Al(PO3)3: 5%~12%; AlF3: 22%~33%; BaF2: 7.5%~15%; SrF2: 20%~30%; CaF2: 25.17%~30%; MgF2: 2%~7%; YF3: 0.5%~8%; LiF: 0.05%~0.45%; The ratio of the content of Al(PO3)3 to the content of LiF, Al(PO3)3 / LiF, is 13~180; the above percentages are all mass percentages;

Images