Fluorophosphate optical glass, optical preforms and optical components

Abstract

This invention provides a fluorophosphate optical glass, the composition of which is expressed as a mole percentage, and the cationic component contains: Al 3+ 30-42%; Mg 2+ 3-10%; Ca 2+ : 15~27%; Sr 2+ : 15~30%; Ba 2+ : 1~10%; Y 3+ : 1~6%; Li + : 2~6%; P 5+ : 1~9%; La 3+ : 0~3%; Gd 3+ : 0~3%; Na + :0~3%, of which Y 3+ / (La 3+ +Gd 3+ The value is above 1.0; the anionic component contains: O 2‑ : 1.5~20%; F ‑ : 80~98.5%; Cl ‑ : 0~0.5%. Through reasonable component design, the optical glass of the present invention has a high Abbe number and good anti-crystallization properties.

Description

[0001] This application is a divisional application of the invention patent application with application number 202310731889.X, application date June 20, 2023, entitled "Fluorophosphate optical glass, optical preforms and optical elements". Technical Field

[0002] This invention relates to the field of optical glass, and more specifically to an ultra-low dispersion fluorophosphate optical glass. Background Technology

[0003] Compact optical systems such as camera lenses and telescopes are often made of low-dispersion, low-refractive-index materials and high-refractive-index materials. Fluorophosphate glass is a type of optical glass that can achieve low dispersion and has better manufacturing performance than fluorine glass.

[0004] For fluorophosphate glasses, one development direction is to achieve ultra-low dispersion, i.e., glasses with an Abbe number greater than 95, to achieve excellent achromatic and apochromatic capabilities and improve the imaging quality of optical systems. Existing patents disclose fluorophosphate glasses with Abbe numbers greater than 95, such as Chinese patent CN103708727A, which discloses a fluorophosphate optical glass with an Abbe number of 90-100, and Chinese patent CN102300823A, which discloses a fluorophosphate optical glass with an Abbe number above 85. However, the glass composition in these patents is not fully optimized, leaving room for improvement in their anti-crystallization performance. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a fluorophosphate optical glass with a high Abbe number and excellent anti-crystallization performance.

[0006] The technical solution adopted by this invention to solve the technical problem is: Fluorophosphate optical glass, whose composition is expressed as mole percentage, contains the following cationic components: Al 3+ 30-42%; Mg 2+ 3-10%; Ca 2+ : 15~27%; Sr 2+ : 15~30%; Ba 2+ : 1~10%; Y 3+ : 1~6%; Li + : 2~6%; P 5+ : 1-9%; The anionic component contains: O 2- : 1.5~20%; F - : 80~98.5%.

[0007] Furthermore, the fluorophosphate optical glass, whose composition is expressed as a mole percentage, also contains the following cationic component: La3+ : 0–3%; and / or Gd 3+ : 0–3%; and / or Na + : 0-3%.

[0008] Fluorophosphate optical glass, the composition of which is expressed as a mole percentage, with the cationic component consisting of Al 3+ 30-42%; Mg 2+ 3-10%; Ca 2+ : 15~27%; Sr 2+ : 15~30%; Ba 2+ : 1~10%; Y 3+ : 1~6%; Li + : 2~6%; P 5+ : 1~9%; La 3+ : 0~3%; Gd 3+ : 0~3%; Na + Composition: 0-3%; The anionic component consists of O 2- : 1.5~20%; F - : 80~98.5%; Cl - Composition: 0-0.5%.

[0009] Furthermore, the composition of the aforementioned fluorophosphate optical glass is expressed as a mole percentage, wherein: Ca 2+ / Sr 2+ The value is 0.6–1.6, with Ca being the preferred choice. 2+ / Sr 2+ The value is 0.7–1.4, with Ca being more preferred. 2+ / Sr 2+ The value ranges from 0.75 to 1.35.

[0010] Furthermore, the composition of the aforementioned fluorophosphate optical glass is expressed as a mole percentage, wherein: Y 3+ +La 3+ +Gd 3+ The concentration is 1.5% to 7%, with Y being the preferred choice. 3+ +La 3+ +Gd 3+ The value is 2-6%, with Y being more preferred. 3+ +La 3+ +Gd 3+ It ranges from 2.5% to 4.5%.

[0011] Furthermore, the composition of the aforementioned fluorophosphate optical glass is expressed as a mole percentage, wherein: Y 3+ / (La 3+ +Gd 3+ If the value is 1.0 or higher, Y is preferred. 3+ / (La3+ +Gd 3+ A value of 2.0 or higher is preferred for Y. 3+ / (La 3+ +Gd 3+ The value ranges from 2.0 to 15.0.

[0012] Furthermore, the composition of the aforementioned fluorophosphate optical glass is expressed as a mole percentage, wherein: Li + / Mg 2+ The value is 0.28–0.8, with Li being the preferred choice. + / Mg 2+ The value is 0.3 to 0.75, with Li being more preferred. + / Mg 2+ The value ranges from 0.32 to 0.7.

[0013] Furthermore, the composition of the aforementioned fluorophosphate optical glass is expressed as a mole percentage, wherein: Li + / (Li + +Na + The value is 0.5 or higher, with Li being the preferred choice. + / (Li + +Na + The value is 0.6 or higher, and Li is preferred. + / (Li + +Na + The value is above 0.75.

[0014] Furthermore, the composition of the aforementioned fluorophosphate optical glass is expressed as a mole percentage, wherein: O 2- / P 5+ The value is 2.5–3.5, with O being the preferred value. 2- / P 5+ The value is 2.5 to 3.25, with O being more preferred. 2- / P 5+ It ranges from 2.5 to 3.0.

[0015] Furthermore, the composition of the aforementioned fluorophosphate optical glass is expressed as a mole percentage, wherein: Al 3+ 33-41%, with Al being the preferred choice. 3+ 36-40%; and / or Mg 2+ 4-9%, preferably Mg 2+ 5-8%; and / or Ca 2+ 16-25%, preferably Ca 2+ : 17-23%; and / or Sr 2+ 16-28%, with Sr preferred 2+ : 17–26%; and / or Ba 2+ 2-8%, Ba is preferred 2+ : 3-6%; and / or Y3+ 1.5-5%, Y is preferred 3+ 2-4%; and / or Li + 2.5%–5.5%, with Li preferred. + 3-5%; and / or P 5+ 2-8.5%, P is preferred 5+ 3-8%; and / or La 3+ 0.2-2.5%, with La preferred. 3+ 0.3–2%; and / or Gd 3+ 0.1-2.5%, with Gd preferred. 3+ 0.2–2%; and / or Na + 0.3-2%, preferably Na + : 0.4~1%.

[0016] Furthermore, the composition of the aforementioned fluorophosphate optical glass is expressed as a mole percentage, wherein: O 2- 4-18%, preferred O 2- : 7–16%; and / or F - 82-96%, with F being the preferred option. - : 84~93%.

[0017] Furthermore, the aforementioned fluorophosphate optical glass, whose composition is expressed as a mole percentage, also contains: Cl - 0-0.5%, preferably Cl - 0-0.2%, more preferably Cl - : 0~0.1%.

[0018] Furthermore, the aforementioned fluorophosphate optical glass does not contain potassium (K) in its composition. + ; and / or does not contain Zr 4+ ; and / or does not contain Zn 2+ ; and / or does not contain Be 2+ ; and / or does not contain Pb 2+ ; and / or does not contain Tl + ; and / or does not contain Rb + ; and / or does not contain Cs + .

[0019] Furthermore, the refractive index n of the fluorophosphate optical glass... d The Abbe number ν ranges from 1.4200 to 1.4350. d The preferred refractive index is 95-99. d and Abbe number ν dIn the field of optical glass, the region enclosed by the lines connecting the following four points on the diagram is: refractive index 1.425, Abbe number 95.50; refractive index 1.4340, Abbe number 96.50; refractive index 1.4210, Abbe number 97.80; refractive index 1.43170, Abbe number 98.50, and more preferably, refractive index n. d and Abbe number ν d In the field of optical glass, the region enclosed by the lines connecting the following four points is: refractive index 1.4255, Abbe number 96.10; refractive index 1.4335, Abbe number 96.80; refractive index 1.4330, Abbe number 97.55; refractive index 1.4317, Abbe number 98.20.

[0020] Furthermore, the fluorophosphate optical glass described above (T) x -T g ) / (T m -T g The value of T is 0.36 or higher, preferably 0.38 or higher, and more preferably 0.40 or higher, wherein T g T is the temperature at which the lowest endothermic peak in the differential thermal analysis curve is tangent to the baseline. x T represents the temperature corresponding to the peak position of the lowest temperature crystallization exothermic peak in the differential thermal analysis curve. m The temperature corresponding to the peak position of the highest crystallization exothermic peak in the differential thermal analysis curve; and / or the stability due to water resistance, D. w Class 3 or more, preferably Class 2 or more; and / or acid resistance stability D A It should be of 4 or more categories, preferably 3 or more categories.

[0021] The optical preform is made of the aforementioned fluorophosphate optical glass.

[0022] The optical element is made of the aforementioned fluorophosphate optical glass or the aforementioned optical preform.

[0023] The beneficial effects of this invention are: through reasonable component design, the optical glass of this invention has a high Abbe number and good anti-crystallization properties. Detailed Implementation

[0024] The embodiments of the fluorophosphate optical glass of the present invention will now be described in detail. However, the present invention is not limited to the embodiments described below, and appropriate modifications can be made to implement it within the scope of the purpose of the present invention. Furthermore, regarding repeated descriptions, although there are appropriate omissions, this will not limit the spirit of the invention. In the following text, the fluorophosphate optical glass of the present invention will sometimes be simply referred to as optical glass or glass.

[0025] [Fluorophosphate optical glass] The composition range of each component in the optical glass of this invention is described below. In this specification, unless otherwise specified, the content of a cationic component is expressed as the molar percentage (mol%) of the cation in all cationic components, and the content of anionic components is expressed as the molar percentage of the anion in all anionic components; the ratio between the contents of cationic components is the ratio of the molar percentage contents of each cationic component; the ratio between the contents of anionic components is the ratio of the molar percentage contents of each anionic component; the total content is expressed as an ion molar percentage. It should be noted that the valence values ​​of each component in this invention are representative values ​​used for convenience and are not different from other ion valence values. Some elements mentioned in the following description may have one or more possible valence states; in this specification, a representative valence state of the element is used for description.

[0026] In this invention, the description of the relationships between the contents of each component involves multiplication and / or division. The component content is calculated using its actual percentage value. For example, when the component content percentage is 10%, it is calculated as 0.1 in multiplication and / or division relationships.

[0027] Unless otherwise specified in the specific context, the numerical ranges listed herein include upper and lower limits. "Above" and "below" include endpoint values ​​and all integers or fractions included within the range, but are not limited to the specific values ​​listed when the range is defined. The term "and / or" as used herein is inclusive; for example, "A and / or B" means either only A, or only B, or both A and B.

[0028] The glass of this invention, based on the aluminum fluoride glass system, achieves not only ultra-low dispersion through appropriate component design and reasonable addition of additional components, but also possesses a relatively high refractive index, making it more suitable for compact, high-image-quality optical systems. Furthermore, the fluorophosphate glass of this invention also exhibits good manufacturing performance.

[0029] <Catonic Components> The glass of this invention has a total cation content of 100%. Impurity elements are not included in the cation content.

[0030] Al 3+ It exhibits good glass-forming properties in fluoride glass systems. Al 3+ It helps to increase the Abbe number of glass, but Al 3+ Excessive Al content can easily lead to the precipitation of AlF3 crystals in the glass, resulting in a significant decrease in the glass's resistance to crystallization. Therefore, Al... 3+ The content is 30-42%, preferably 33-41%, and more preferably 36-40%.

[0031] In the glass of this invention, Mg2+ It helps to increase the Abbe number of the glass, thereby achieving low dispersion properties. However, Mg... 2+ When the content exceeds a certain limit, the glass's resistance to crystallization will significantly deteriorate. Therefore, Mg... 2+ The content is 3-10%, preferably 4-9%, and more preferably 5-8%.

[0032] Ca 2+ It exhibits good glass-forming properties in fluoride glasses. In the glass of this invention, Ca... 2+ The content of Ca needs to be greater than a certain range to ensure that other components in the glass have appropriate contents and that the glass has good resistance to crystallization. However, Ca... 2+ At higher concentrations, CaAlF5 crystals tend to form in the glass, leading to a decrease in the glass's resistance to crystallization. Therefore, Ca... 2+ The content is 15-27%, preferably 16-25%, and more preferably 17-23%.

[0033] Sr 2+ The glass-forming properties of Ca 2+ Essentially similar. In the glass of this invention, due to the matching relationship of cation radii, within a certain range, Sr... 2+ Increasing the content of Sr can improve the glass's resistance to crystallization. 2+ The presence of Sr also makes it difficult for CaAlF5 crystals to precipitate in the glass, because Sr 2+ Can occupy Ca 2+ The position of Sr within the CaAlF5 crystal appropriately increases the difficulty of CaAlF5 crystal precipitation in the glass. Therefore, Sr 2+ The content is 15-30%, preferably 16-28%, and more preferably 17-26%.

[0034] In some implementations, controlling Ca 2+ / Sr 2+ Within the range of 0.6 to 1.6, the tendency for CaAlF5 and SrAlF5 crystals to precipitate in the glass is low, resulting in excellent resistance to crystallization and good acid resistance. Therefore, CaAlF5 is preferred. 2+ / Sr 2+ The value is 0.6–1.6, with Ca being more preferred. 2+ / Sr 2+ The value of Ca is 0.7–1.4, with further optimization. 2+ / Sr 2+ The value ranges from 0.75 to 1.35.

[0035] Ba 2+ It can improve the anti-crystallization properties of glass, but Ba 2+Excessive Ba content makes it difficult to achieve high Abbe number properties in glass. Therefore, Ba... 2+ The content is 1-10%, preferably 2-8%, and more preferably 3-6%.

[0036] Y 3+ It is an essential component of the glass of this invention. Appropriately containing Y in the glass... 3+ This is beneficial for improving the chemical stability and anti-crystallization properties of glass. Meanwhile, Y... 3+ Its contribution to the Abbe number is superior to that of Ca. 2+ 、Sr 2+ Ba 2+ The glass contains a certain amount of Y, therefore it has the same composition. 3+ It has a good effect on increasing the Abbe number of glass. However, Y 3+ If the content exceeds a certain limit, the glass composition falls outside the glass-forming region, and glass cannot form. Therefore, Y 3+ The content is 1-6%, preferably 1.5-5%, and more preferably 2-4%.

[0037] La 3+ The ability to improve the Abbe number of glass and the ability to improve the glass's resistance to crystallization are both slightly lower than those of Y. 3+ However, the glass contains a small amount of La. 3+ This helps reduce the tendency of glass to crystallize. Therefore, La 3+ The content is 0-3%, preferably 0.2-2.5%, and more preferably 0.3-2%.

[0038] Gd 3+ The ability to improve the anti-crystallization properties of glass, the effect on the glass refractive index, and the ability to increase the Abbe number are all related to La. 3+ Similarly, small amounts of Gd are present in the glass. 3+ This helps reduce the tendency of glass to crystallize. Therefore, Gd 3+ The content is 0-3%, preferably 0.1-2.5%, and more preferably 0.2-2%.

[0039] In some implementations, controlling Y 3+ +La 3+ +Gd 3+ Within the range of 1.5% to 7%, the glass exhibits good resistance to crystallization. Therefore, Y is preferred. 3+ +La 3+ +Gd 3+ The content is 1.5% to 7%, with Y being more preferred. 3+ +La 3+ +Gd 3+ The value is 2-6%, and Y is further optimized. 3+ +La 3+ +Gd 3+It ranges from 2.5% to 4.5%.

[0040] In some implementations, controlling Y 3+ / (La 3+ +Gd 3+ A value above 1.0 is beneficial for improving the glass's resistance to crystallization and its stability under water resistance. Therefore, Y is preferred. 3+ / (La 3+ +Gd 3+ A value of 1.0 or higher is preferred for Y. 3+ / (La 3+ +Gd 3+ If the value is 2.0 or higher, Y will be further optimized. 3+ / (La 3+ +Gd 3+ The value ranges from 2.0 to 15.0.

[0041] Li + It is an essential component of the glass of this invention. In fluoride glasses, Li is... + It can significantly improve the Abbe number of glass. In terms of processing, the glass contains Li... + It facilitates the melting of glass raw materials, indirectly reducing the volatilization of fluorine during the melting process, thereby contributing to an increase in the Abbe number of the glass of this invention. However, Li... + It significantly reduces glass viscosity, which is a negative property in fluoride glasses, making it difficult to control the viscosity of the molten glass and reducing the forming operation window. On the other hand, a higher Li content... + This will reduce the refractive index of the glass, thus limiting its effectiveness in achromatic applications. Meanwhile, Li... + If the Li content exceeds a certain range, it can easily lead to the formation of Li-containing crystals in the glass. Therefore, the Li content in the glass of this invention... + The content is 2-6%, preferably 2.5-5.5%, and more preferably 3-5%.

[0042] In some implementations, controlling Li + / Mg 2+ Within the range of 0.28 to 0.8, the tendency for Li₂MgF₄ crystals to precipitate in the glass decreases, indicating good resistance to crystallization. Therefore, Li₂MgF₄ is preferred. + / Mg 2+ The value is 0.28 to 0.8, with Li being more preferred. + / Mg 2+ The value is 0.3–0.75, with Li being the most preferred. + / Mg 2+ The value ranges from 0.32 to 0.7.

[0043] In the glass of this invention, Na + The increased content of [Li] leads to a decrease in the Abbe number of the glass. However, in the glass of this invention containing Li...+ In the case of Na in glass + The presence of [Li] can increase the refractive index of the glass without significantly reducing the Abbe number, causing the refractive index of the glass to deviate from the typical refractive index-Abbe number relationship of fluorophosphate glasses, thus making the glass more suitable for achromatic optical design. In this invention, the glass contains Li... + In the case of Na in glass + The presence of Na also contributes to improved glass chemical stability. However, Na... + Excessive Na content not only leads to a significant decrease in the Abbe number of the glass but also reduces its chemical stability. Therefore, the Na content in the glass of this invention... + The content is 0-3%, preferably 0.3-2%, and more preferably 0.4-1%.

[0044] In some implementations, controlling Li + / (Li + +Na + When the refractive index is 0.5 or higher, preferably 0.6 or higher, and more preferably 0.75 or higher, the refractive index and Abbe number of the glass are more likely to reach the target values ​​of the present invention.

[0045] P 5+ It is an essential component of the glass of this invention. In fluorophosphate glass, within a certain range, P... 5+ Increasing the content can significantly improve the glass's resistance to crystallization. However, P 5+ Excessive P content will significantly reduce the Abbe number of the glass. Therefore, P 5+ The content is 1-9%, preferably 2-8.5%, and more preferably 3-8%.

[0046] K + Zr 4+ In glass, this will severely impair the glass's resistance to crystallization. Therefore, the glass of the present invention preferably does not contain K. + and / or does not contain Zr 4+ .

[0047] Zn 2+ It can modify glass, provide gloss, and improve the chemical stability of glass. However, ZnF2 is a highly toxic raw material. Therefore, this invention preferably does not contain Zn. 2+ .

[0048] The glass of this invention does not contain biotoxic Be. 2+ Pb 2+ 、Tl + And expensive Rb + Cs + Components.

[0049] <Anionic components> O 2- It is a component that forms the glass network. 2- This is beneficial for improving the glass's resistance to crystallization and its production performance. However, O 2- Excessive content makes it difficult to achieve the desired refractive index and dispersion properties of the glass of this invention. Therefore, O 2- The content is 1.5-20%, preferably 4-18%, and more preferably 7-16%.

[0050] F - It can combine with the cations contained in the glass of this invention to form an ionic glass. However, F - Excessive content reduces the glass's resistance to crystallization and its production performance. Therefore, F - The content is 80-98.5%, preferably 82-96%, and more preferably 84-93%.

[0051] Cl - Cl has a certain clarifying effect on glass. - The content ranges from 0 to 0.5%, preferably from 0 to 0.2%, and more preferably from 0 to 0.1%.

[0052] O 2- / P 5+ The value of O is mainly related to the way phosphorus is introduced into the glass; different introduction methods correspond to different values. 2- / P 5+ Different. In glass, O 2- When all phosphorus is introduced as phosphorus oxide, the glass O 2- / P 5+ It is 2.5. 2- / P 5+ An excessively high O value leads to the presence of free oxygen in the glass. This free oxygen, located within the fluorine network, easily degrades the glass's crystallization properties. However, the O value in the glass... 2- / P 5+ If the value is too small, the corresponding raw material introduction methods are mainly phosphorus oxide and phosphoric acid, which are hygroscopic and toxic, which are detrimental to personnel safety protection and control of glass refractive index stability during the production process. Therefore, O is preferred in the glass of this invention. 2- / P 5+ The value is 2.5 to 3.5, with O being more preferred. 2- / P 5+ The value is 2.5–3.25, with O being the preferred option. 2- / P 5+ It ranges from 2.5 to 3.0.

[0053] The performance of the optical glass of the present invention will now be described.

[0054] <Refractive index and Abbe number> The refractive index (n) of the glass was tested using the standard method specified in GB / T 7962.1-2010. d ) and Abbe number (ν d ).

[0055] In some embodiments, the refractive index (n) of the glass of the present invention d The Abbe number (ν) ranges from 1.4200 to 1.4350. d The preferred refractive index (n) of the glass of this invention is 95-99. d Abbe number (ν) d The region enclosed by the lines connecting the following four points on the optical glass diagram is defined as follows: (refractive index 1.425, Abbe number 95.50), (refractive index 1.4340, Abbe number 96.50), (refractive index 1.4210, Abbe number 97.80), and (refractive index 1.43170, Abbe number 98.50). A more preferred refractive index (n) for the glass of the present invention is... d Abbe number (ν) d The region enclosed by the lines connecting the following four points on the optical glass field diagram is: (refractive index 1.4255, Abbe number 96.10), (refractive index 1.4335, Abbe number 96.80), (refractive index 1.4330, Abbe number 97.55), and (refractive index 1.4317, Abbe number 98.20).

[0056] Anti-crystallization properties For fluorophosphate glasses, especially ultra-low dispersion fluorophosphate glasses, anti-crystallization performance is the most critical property, directly determining whether a stable product can be formed and applied in optical design. Poor anti-crystallization performance leads to problems such as more inclusions in the glass, poor production yield, difficulty in controlling the melting and forming process, and incompatibility with hot working processes.

[0057] This invention characterizes the anti-crystallization properties of glass using differential thermal analysis (DTA). Glass samples free of crystallization, internal defects, and casting surface layers are ground into powder and subjected to DTA testing at a fixed heating rate of 10°C per minute. The glass transition temperature (Tg) is obtained from the DTA curve. g ), main crystallization peak temperature (T) x ), lower limit temperature of glass liquid phase (T) m In this invention, the relationship between the above temperature and the differential thermal analysis curve is as follows: T g The temperature at the point where the lowest endothermic peak in the differential thermal analysis curve is tangent to the baseline.

[0058] T x The temperature corresponding to the peak position of the lowest exothermic crystallization peak in the differential thermal analysis curve. In fluorophosphate glass, this crystallization peak is generally the dominant crystallization peak.

[0059] T m The temperature corresponding to the peak position of the highest temperature crystallization exothermic peak in the differential thermal analysis curve.

[0060] Use (T) x -T g ) / (T m -T g The evaluation of the glass's resistance to crystallization is based on (T). x -T g The larger the value of T, the stronger the glass's ability to withstand supercooling without crystallization, and the greater its resistance to crystallization during the forming process; m -T g The larger the temperature of the glass melt, the faster it needs to be cooled during the forming process to prevent crystallization, which often results in the glass remaining at temperature T. x The longer the time spent nearby, the weaker the ability to resist crystallization.

[0061] In some embodiments, the glass of the present invention (T) x -T g ) / (T m -T g The value is 0.36 or higher, preferably 0.38 or higher, and more preferably 0.40 or higher.

[0062] <Stability under water resistance> Water resistance stability of glass (D) w Test according to the method specified in GB / T 17129.

[0063] In some embodiments, the water resistance stability (D) of the glass of the present invention is... w () There are 3 or more categories, preferably 2 or more categories.

[0064] <Stability under acid conditions> Acid resistance stability of glass (D) A Test according to the method specified in GB / T 17129.

[0065] In some embodiments, the acid resistance stability (D) of the glass of the present invention is... A The number of categories is 4 or more, preferably 3 or more.

[0066] [Manufacturing Method] The manufacturing method of the glass of this invention is as follows: Common glass raw materials (such as fluorides, phosphates, metaphosphates, phosphorus oxides, phosphoric acid, oxides, hydroxides, etc.) are weighed and mixed according to the glass composition. The mixed raw materials are placed in a melting device and heated and melted. The melting process of the glass raw materials of this invention is generally completed in a platinum chamber. Before the melting process begins, the glass raw materials should be placed in a heating furnace with a certain drying temperature to avoid moisture absorption; preferably, the drying temperature is higher than 120°C. The melting temperature (melting temperature) of the glass raw materials of this invention is preferably 800–1100°C, more preferably 825–1050°C, and even more preferably 850–1000°C. After the above raw materials are completely melted and vitrified, the glass temperature is raised or lowered to its clarification temperature and maintained for a certain period of time to clarify the molten glass. The clarification temperature of the glass of this invention is preferably 750–1100°C, more preferably 775–1050°C, and even more preferably 800–1000°C. The clarification time is preferably 0.2 to 12 hours, more preferably 0.5 to 11 hours, and even more preferably 1 to 10 hours. The molten glass after the clarification process is homogenized by stirring, or continuously supplied to a glass outflow pipe for outflow, and then rapidly cooled and solidified in a glass mold to obtain a glass composition; or it is poured from a molten container into a mold of a specific shape, and after rapid cooling, solidification, and annealing, glass is obtained.

[0067] During the melting and refining process of the glass of this invention, appropriate equipment and processes should be used to minimize the volatilization of sulfur (F). During the mixing, weighing, and melting process of the raw materials for the glass of this invention, appropriate equipment and processes should be used to prevent the raw materials from absorbing moisture. Within the above principles and process parameters, those skilled in the art can appropriately select raw materials, process methods, and process parameters based on equipment characteristics and actual needs.

[0068] <Example of Optical Glass> To further clarify and illustrate the technical solution of the present invention, the following non-limiting embodiments are provided. In this embodiment, optical glasses as shown in Tables 1 to 4 are obtained using the aforementioned optical glass manufacturing method. Furthermore, the characteristics of each glass are measured using the testing method described in this invention, and the measurement results are shown in Tables 1 to 4.

[0069] Table 1.

[0070] Table 2.

[0071] Table 3.

[0072] Table 4.

[0073] <Optical Preform Example> The optical glass obtained in Examples 1 to 24 of Tables 1 to 4 is cut into predetermined sizes, and a release agent composed of boron nitride powder is uniformly coated on the surface. Then, it is heated and softened, and pressure molded to produce preforms of various lenses and prisms such as concave meniscus lenses, convex meniscus lenses, biconvex lenses, biconcave lenses, plano-convex lenses, and plano-concave lenses.

[0074] <Optical Component Examples> Annealing these preforms obtained from the above-described optical preform embodiments reduces internal deformation of the glass while fine-tuning them so that optical properties such as refractive index reach the desired values.

[0075] Next, the prefabricated parts are ground and polished to produce various lenses and prisms, such as concave meniscus lenses, convex meniscus lenses, biconvex lenses, biconcave lenses, plano-convex lenses, and plano-concave lenses. An anti-reflective film can also be coated on the surface of the resulting optical elements.

Claims

1. Fluorophosphate optical glass, characterized in that, Its components are expressed as mole percentages, and the cationic component contains: Al 3+ 30-42%; Mg 2+ 3-10%; Ca 2+ : 15~27%; Sr 2+ : 15~30%; Ba 2+ : 1~10%; Y 3+ : 1~6%; Li + : 2~6%; P 5 + : 1~9%; La 3+ : 0~3%; Gd 3+ : 0~3%; Na + :0~3%, of which Y 3+ / (La 3+ +Gd 3+ The value is 1.0 or higher; The anionic component contains: O 2- : 1.5~20%; F - : 80~98.5%; Cl - : 0~0.5%.

2. Fluorophosphate optical glass, characterized in that, Its components are expressed as mole percentages, with the cationic component consisting of Al 3+ 30-42%; Mg 2+ 3-10%; Ca 2+ : 15~27%; Sr 2+ : 15~30%; Ba 2+ : 1~10%; Y 3+ : 1~6%; Li + : 2~6%; P 5+ : 1~9%; La 3+ : 0~3%; Gd 3+ : 0~3%; Na + Composed of 0-3%, of which Y 3+ / (La 3+ +Gd 3+ The value is 1.0 or higher; The anionic component consists of O 2- : 1.5~20%; F - : 80~98.5%; Cl - Composition: 0-0.5%.

3. The fluorophosphate optical glass as described in claim 1 or 2, characterized in that, Its components are expressed as mole percentages, where: Ca 2+ / Sr 2+ The value is 0.6–1.6, with Ca being the preferred choice. 2+ / Sr 2+ The value is 0.7–1.4, with Ca being more preferred. 2+ / Sr 2+ The value of Ca is 0.75–1.35, with further optimization. 2+ / Sr 2+ The value is 0.75 to 1.253; and / or Y 3+ +La 3+ +Gd 3+ The concentration is 1.5% to 7%, with Y being the preferred choice. 3+ +La 3+ +Gd 3+ The value is 2-6%, with Y being more preferred. 3+ +La 3+ +Gd 3+ It is 2.5% to 4.5%; and / or Y 3+ / (La 3+ +Gd 3+ A value of 2.0 or higher is preferred for Y. 3+ / (La 3+ +Gd 3+ The value of Y is 2.0 to 15.0, with Y being more preferred. 3+ / (La 3+ +Gd 3+ The value is 2.0–10.0; and / or Li + / Mg 2+ The value is 0.28–0.8, with Li being the preferred choice. + / Mg 2+ The value is 0.3 to 0.75, with Li being more preferred. + / Mg 2+ 0.32–0.7; and / or Li + / (Li + +Na + The value is 0.5 or higher, with Li being the preferred choice. + / (Li + +Na + The value is 0.6 to 0.968, with Li being more preferred. + / (Li + +Na + The value of Li is 0.75–0.938, and Li is further preferred. + / (Li + +Na + The value is 0.75–0.9; and / or O 2- / P 5+ The value is 2.5–3.5, with O being the preferred value. 2- / P 5+ The value is 2.5 to 3.25, with O being more preferred. 2- / P 5+ It ranges from 2.5 to 3.

0.

4. The fluorophosphate optical glass as described in claim 1 or 2, characterized in that, Its components are expressed as mole percentages, of which: Al 3+ 33-41%, with Al being the preferred choice. 3+ 36-40%; and / or Mg 2+ 4-9%, preferably Mg 2+ 5-8%; and / or Ca 2+ 16-25%, preferably Ca 2+ : 17-23%; and / or Sr 2+ 16-28%, with Sr preferred 2+ : 17–26%; and / or Ba 2+ 2-8%, Ba is preferred 2 + : 3-6%; and / or Y 3+ 1.5-5%, Y is preferred 3+ 2-4%; and / or Li + 2.5%–5.5%, with Li preferred. + 3-5%; and / or P 5 + 2-8.5%, P is preferred 5+ 3-8%; and / or La 3+ 0.2-2.5%, with La preferred. 3+ 0.3–2%; and / or Gd 3+ 0.1-2.5%, with Gd preferred. 3+ 0.2–2%; and / or Na + 0.3-2%, preferably Na + : 0.4~1%.

5. The fluorophosphate optical glass as described in claim 1 or 2, characterized in that, Its components are expressed as mole percentages, of which: O 2- 4-18%, preferred O 2- : 7–16%; and / or F - 82-96%, with F being the preferred option. - : 84–93%; and / or Cl - 0-0.2%, preferably Cl - : 0~0.1%.

6. The fluorophosphate optical glass as described in claim 1 or 2, characterized in that, Its components do not contain K + ; and / or does not contain Zr 4+ ; and / or does not contain Zn 2+ ; and / or does not contain Be 2+ ; and / or does not contain Pb 2+ ; and / or does not contain Tl + ; and / or does not contain Rb + ; and / or does not contain Cs + .

7. The fluorophosphate optical glass as described in claim 1 or 2, characterized in that, The refractive index n of the fluorophosphate optical glass d The Abbe number ν ranges from 1.4200 to 1.4350. d The preferred refractive index is 95-99. d and Abbe number ν d In the field of optical glass, the region enclosed by the lines connecting the following four points on the diagram is: refractive index 1.425, Abbe number 95.50; refractive index 1.4340, Abbe number 96.50; refractive index 1.4210, Abbe number 97.80; refractive index 1.43170, Abbe number 98.50, and more preferably, refractive index n. d and Abbe number ν d In the field of optical glass, the region enclosed by the lines connecting the following four points is: refractive index 1.4255, Abbe number 96.10; refractive index 1.4335, Abbe number 96.80; refractive index 1.4330, Abbe number 97.55; refractive index 1.4317, Abbe number 98.

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8. The fluorophosphate optical glass as described in claim 1 or 2, characterized in that, The fluorophosphate optical glass (T) x -T g ) / (T m -T g The value of T is 0.36 or higher, preferably 0.38 or higher, and more preferably 0.40 or higher, wherein T g T is the temperature at which the lowest endothermic peak in the differential thermal analysis curve is tangent to the baseline. x T represents the temperature corresponding to the peak position of the lowest temperature crystallization exothermic peak in the differential thermal analysis curve. m The temperature corresponding to the peak position of the highest crystallization exothermic peak in the differential thermal analysis curve; and / or the stability due to water resistance, D. w Class 3 or more, preferably Class 2 or more; and / or acid resistance stability D A It should be of 4 or more categories, preferably 3 or more categories.

9. An optical preform, characterized in that, It is made of fluorophosphate optical glass as described in any one of claims 1 to 8.

10. An optical element, characterized in that, It is made of fluorophosphate optical glass as described in any one of claims 1 to 8, or of optical preform as described in claim 9.

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