Optical filter glass, method for producing the same, and optical element

Abstract

The application provides a filter glass, a preparation method thereof and an optical element. The filter glass comprises the following components in percentage by weight: SiO2: 30-70%; B2O3: 3-20%; ZnO: 8-30%; CdS: 1-10%; Se: 0.4-5%; Te: 0.5-5%; Al2O3: 0-3%; the sum of the content of Li2O, Na2O and K2O (Li2O+Na2O+K2O) is 5-28%; and the sum of the content of MgO, CaO, BaO and SrO (MgO+CaO+BaO+SrO) is 0-8%. The filter glass has relatively low production cost, and the ultraviolet and visible light cutoff in the crystal formation process is relatively controllable, and has very high transmittance at the near-infrared end.

Description

TECHNICAL FIELD

[0001] The present application relates to a filter glass, a preparation method thereof and an optical element, and belongs to the field of filter glasses. BACKGROUND

[0002] In recent years, with the development of the photoelectric industry, the application degree of near-infrared band detection is higher and higher, especially in intelligent technologies and devices such as unmanned driving, the real-time perception of the surrounding environment by using near-infrared laser, thereby providing decision-making for the action and movement of intelligent devices. In order to accurately perceive the external environment, the optical system needs to have high near-infrared transmittance, and at the same time, be able to filter out ultraviolet light and visible light well. At present, the methods that can better complete this function in the glass industry are glass coating and glass coloring.

[0003] Compared with glass coloring, the coating technology is more difficult and has higher cost, and the film layer may interfere with the imaging optical signal. In glass coloring, ion-colored glass has light absorption, discontinuous transmittance band and low transmittance, and the preparation process of colloidal colored glass is complex, has high cost and low cutoff degree, so these two types of glasses cannot provide accurate external real scene for the optical system, and semiconductor quantum dot glass, especially CdSe-CdTe quantum dot glass, can realize the properties of ultraviolet and visible light cutoff and high transmittance in the near-infrared region.

[0004] Patent CN105293906A discloses a CdTe quantum dot doped glass and a preparation method thereof, the raw material ZnTe for forming quantum dots has high cost, and is easily oxidized in the high-temperature smelting process, so it is difficult to form CdTe quantum dot crystals in the glass. Patent CN111662008A discloses an Sb2Se3 quantum dot glass with ultraviolet and visible light cutoff and high transmittance in the near-infrared region and a preparation method thereof, and the formation potential of Sb2Se3 quantum dots is relatively large, and the crystal formation is difficult.

[0005] Therefore, it is a technical problem to be solved to study a cutoff type filter glass with ultraviolet and visible light cutoff and high transmittance in the near-infrared region, which has relatively low production cost and a relatively controllable crystal formation process, and a preparation method thereof. SUMMARY

[0006] Problems to be solved by the application

[0007] In view of the technical problems in the prior art, the present application first provides a filter glass with ultraviolet and visible light cutoff and high transmittance in the near-infrared region, which has relatively low production cost and a relatively controllable crystal formation process.

[0008] Further, the present application also provides a preparation method of the filter glass, which is simple and easy to implement, the raw materials are easy to obtain, and is suitable for mass production.

[0009] Solution for solving the problem

[0010] This invention provides a filter glass, comprising the following components in weight percentage:

[0011] SiO2: 30%–70%, preferably 35%–68%, more preferably 38%–65%;

[0012] B2O3: 3%–20%, preferably 4%–15%, more preferably 5%–10%;

[0013] ZnO: 8-30%, preferably 10-28%, more preferably 12-25%;

[0014] CdS: 1-10%, preferably 2-8%, more preferably 2-6%;

[0015] Se: 0.4-5%, preferably 0.7-4%, more preferably 0.8-3.5%;

[0016] Te: 0.5-5%, preferably 0.7-4%, more preferably 0.8-3%;

[0017] Al2O3: 0-3%, preferably 0-2%, more preferably 0-1%;

[0018] The sum of the contents of Li2O, Na2O, and K2O (Li2O+Na2O+K2O) is 5% to 28%, preferably 7% to 23%, and more preferably 9% to 20%.

[0019] The sum of the contents of MgO, CaO, BaO and SrO (MgO+CaO+BaO+SrO) is 0-8%, preferably 0-6%, and more preferably 0-4%.

[0020] According to the filter glass of the present invention, the content of Li₂O in the filter glass, by weight percentage, is 0-3%, preferably 0-1%, more preferably not introduced; the content of Na₂O is 2-9%, preferably 3-8%, more preferably 4-8%; the content of K₂O is 3-16%, preferably 4-14%, more preferably 5-12%; and / or,

[0021] By weight percentage, the filter glass contains 0-2% MgO, preferably 0-1.5%, more preferably 0-1%; 0-2% CaO, preferably 0-1.5%, more preferably 0-1%; 0-2% SrO, preferably 0-1.5%, more preferably 0-1%; and 0-2% BaO, preferably 0-1.5%, more preferably 0-1%.

[0022] The filter glass according to the present application, wherein the ratio of the sum of the contents of SiO2 and Al2O3 to the sum of the contents of B2O3, Li2O, Na2O and K2O, i.e. ∑(SiO2+Al2O3) / ∑(B2O3+Li2O+Na2O+K2O) is 0.5-3.0, preferably 0.8-2.5, more preferably 1-2.2, in terms of weight percentage.

[0023] The filter glass according to the present application, wherein the ratio of ZnO to SiO2, i.e. ZnO / SiO2 is 0.1-1, preferably 0.2-0.8, more preferably 0.3-0.7, in terms of weight percentage.

[0024] The filter glass according to the present application, wherein the ratio of the contents of Se and Te, i.e. Se / Te is less than 2.0, preferably less than 1.5, more preferably less than 1, in terms of weight percentage.

[0025] The filter glass according to the present application, wherein the ratio of the sum of the contents of Se and Te to CdS, i.e. ∑(Se+Te) / CdS is more than 0.05, preferably more than 0.1, more preferably ∑(Se+Te) / CdS is more than 0.2, in terms of weight percentage.

[0026] The filter glass according to the present application, wherein the cut-off wavelength of the filter glass is more than 600 nm when the thickness of the filter glass is 2 mm;

[0027] The transmittance of the filter glass is more than 80% at 850-900 nm, more than 85% at 900-950 nm and more than 88% at 950-2000 nm when the thickness of the filter glass is 2 mm.

[0028] The filter glass according to the present application, wherein the acid resistance of the filter glass is Class 3 or above; the water resistance of the filter glass is Class 3 or above;

[0029] The Young's modulus of the filter glass is more than 61 GPa;

[0030] The coefficient of expansion of the filter glass is more than 80×10-6 / K. 20-300℃ -7 / K.

[0031] The present application also provides a preparation method of the filter glass according to the present application, comprising the following steps:

[0032] The raw materials of the components of the glass are mixed in proportion and then put into a furnace at 1200-1400 ℃ to form a molten glass;

[0033] The molten glass is subjected to homogenization treatment to eliminate the bubbles in the glass;​

[0034] casting or pouring the homogenized molten glass into a mold to form a shaped body;

[0035] placing the shaped body into an annealing furnace, and annealing at 550-700℃ for 24-72h to make the glass perform nucleation reaction, and then annealing at 550-700℃ for 12-72h to make the glass perform crystal growth, thereby obtaining the optical filter glass.

[0036] The present application also provides an optical element comprising the optical filter glass according to the present application.

[0037] Effects of the present application

[0038] The optical filter glass according to the present application has relatively low production cost, and the ultraviolet and visible light cut-off during crystal formation is relatively controllable, and has very high transmittance at the near-infrared end.

[0039] Further, the preparation method of the optical filter glass according to the present application is simple and easy to operate, the raw materials are easy to obtain, and is suitable for mass production. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 is a spectral transmittance curve of the glass of Example 1 of the present application. DETAILED DESCRIPTION

[0041] Various exemplary embodiments, features, and aspects of the present application will be explained in detail in following with reference to the drawings. 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.

[0042] 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 will understand that the present application can be practiced without certain specific details. In some instances, well-known methods, means, instruments and steps have not been described in detail in order to highlight the principles of the present application.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In addition, the nomenclature used in connection with, and the parameters described herein are intended to be consistent with the nomenclature and parameters as commonly used and well understood by those skilled in the art. As used herein, the singular form "a", "an" and "the" include plural references unless the context clearly dictates otherwise.

[0044] In this specification, the meaning of "may" includes both the meaning of performing a certain process and the meaning of not performing a certain process.

[0045] In the present specification, "some specific / preferred embodiments", "other specific / preferred embodiments", "embodiments", and the like mean that the particular element (for example, a feature, structure, property, and / or characteristic) described in relation to the embodiment is included in at least one embodiment described herein, and can or can not be present in other embodiments. In addition, it should be understood that the described elements can be combined in any suitable manner in various embodiments.

[0046] In the present specification, a numerical range expressed using "numerical value A ~ numerical value B" means a range including the end point numerical values A and B.

[0047] In the present specification, when "room temperature" is used, the temperature can be 10 to 40°C.

[0048] "0%" in the present specification means that the compound, element, or the like is not intentionally added as a raw material to the glass of the present application, but some impurities or components not intentionally added can be present as a raw material and / or equipment for producing the glass, and a small amount or a trace amount of the same can be contained in the final glass, and such a case is also within the scope of the present application.

[0049] The present application first provides a filter glass comprising the following components in terms of weight percentage:

[0050] SiO2: 30 to 70%, preferably 35 to 68%, more preferably 38 to 65%;

[0051] B2O3: 3 to 20%, preferably 4 to 15%, more preferably 5 to 10%;

[0052] ZnO: 8 to 30%, preferably 10 to 28%, more preferably 12 to 25%;

[0053] CdS: 1 to 10%, preferably 2 to 8%, more preferably 2 to 6%;

[0054] Se: 0.4 to 5%, preferably 0.7 to 4%, more preferably 0.8 to 3.5%;

[0055] Te: 0.5 to 5%, preferably 0.7 to 4%, more preferably 0.8 to 3%;

[0056] Al2O3: 0 to 3%, preferably 0 to 2%, more preferably 0 to 1%;

[0057] The sum of the contents of Li2O, Na2O, and K2O, Li2O+Na2O+K2O, is 5 to 28%, preferably 7 to 23%, more preferably 9 to 20%;

[0058] The sum of the contents of MgO, CaO, BaO and SrO (MgO+CaO+BaO+SrO) is 0-8%, preferably 0-6%, and more preferably 0-4%.

[0059] The filter glass of the present invention has a relatively low production cost, relatively controllable ultraviolet and visible light cutoff during crystal formation, and very high transmittance at the near-infrared end.

[0060] In the glass system of this invention, SiO2 is a network forger and an important component constituting the proportional framework. It endows the glass with good thermal stability, enabling the quantum dot components to stably combine and form crystals within the glass. Simultaneously, it also gives the glass good chemical stability, mechanical strength, and crystallization properties. If its content is below 30%, the glass has poor thermal stability, uncontrollable quantum dot crystal formation, and the cutoff performance fails to meet design requirements. Furthermore, the glass exhibits poor chemical stability and low mechanical strength. If its content is above 70%, the glass melting process involves high temperatures, leading to significant volatilization of the quantum dot components and a decrease in the glass's cutoff performance. Therefore, the SiO2 content in the composition is 30%–70%, preferably 35%–68%, and more preferably 38%–65%.

[0061] The sum of Li₂O, Na₂O, and K₂O (Li₂O + Na₂O + K₂O) in glass primarily functions to improve glass melting efficiency, reduce high-temperature viscosity, help eliminate bubbles, and enhance the solubility of quantum dot components. When its content is below 5%, the fluxing effect is insignificant, and the glass's expansion properties fall below design standards. If the content exceeds 28%, the free oxygen content in the glass increases, disrupting the network structure and reducing crystallization performance, leading to decreased cutoff performance and near-infrared transmittance, as well as reduced chemical stability and mechanical properties. Therefore, the sum of Li₂O, Na₂O, and K₂O (Li₂O + Na₂O + K₂O) should be 5%–28%, preferably 7%–23%, and more preferably 9%–20%.

[0062] In some specific implementations, Li₂O can effectively reduce the high-temperature viscosity and surface tension of glass, helping to eliminate bubbles in the glass. However, Li… + Li₂O exhibits a strong agglomeration effect in glass, acting as a nucleating agent that easily interferes with the transformation of quantum dot components, reducing the glass's cutoff performance. Furthermore, Li₂O is relatively expensive, and its introduction into glass increases manufacturing costs. Therefore, the Li₂O content in the composition is 0–3%, preferably 0–1%, and more preferably none.

[0063] Na2O in the glass can improve the glass melting efficiency, reduce the high temperature viscosity of glass, help to eliminate bubbles and improve the quantum dot composition dissolution, etc., while also can improve the near-infrared transmittance of glass and the thermal expansion coefficient of glass. When the content of Na2O is too low, the near-infrared transmittance and the expansion coefficient of the glass cannot meet the design requirements, and when the content of Na2O is too high, the chemical stability and crystallization performance of the glass are poor. Therefore, in the present application, the content of Na2O can be 2% to 9%, preferably 3% to 8%, and further preferably 4% to 8%.

[0064] In the present application, the role of Na2O and K2O in the glass is similar, and in addition, K2O improves the steepness of the light absorption curve of the glass. In order to comprehensively ensure the cut-off performance, chemical stability, thermal design requirements and mechanical properties of the glass, the content of K2O in the component is 3% to 16%, preferably 4% to 14%, and further preferably 5% to 12%.

[0065] B2O3 in the glass belongs to the network intermediate, which can accelerate the glass melting and clarification process, but too high content will change the structure of the glass, reduce the solubility of the colorant and the colorant precipitation, resulting in the decline of the glass cut-off performance. Therefore, the content of B2O3 in the component is 3% to 20%, preferably 4% to 15%, and further preferably 5% to 10%.

[0066] Al2O3 in the glass is a network intermediate, which can further enter the network skeleton, making the glass skeleton more compact, and improving the chemical stability, mechanical properties and thermal stability of the glass. However, too high content will increase the difficulty of glass melting, which is not conducive to the formation of quantum dot crystals, therefore the content of Al2O3 in the component is 0 to 3%, preferably 0 to 2%, and further preferably 0 to 1%.

[0067] The viscosity of the glass has an important influence on the growth of quantum dot crystals. In the present application, the ratio of the sum of the content of SiO2 and Al2O3 to the sum of the content of B2O3, Li2O, Na2O and K2O ∑(SiO2+Al2O3) / ∑(B2O3+Li2O+Na2O+K2O) is too high, the glass viscosity is too high, which is not conducive to the formation and growth of crystals in the glass coloring process, and the expansion coefficient of the glass cannot meet the design requirements, if ∑(SiO2+Al2O3) / ∑(B2O3+R2O) is too low, the stability of the glass is poor, which cannot meet the design requirements, therefore ∑(SiO2+Al2O3) / ∑(B2O3+Li2O+Na2O+K2O) is 0.5 to 3.0, preferably 0.8 to 2.5, and further preferably 1 to 2.2.

[0068] ZnO is one of the indispensable components in quantum dot glass. In the process of glass melting, it can form more stable zinc compounds with quantum dot components, which is beneficial to reduce the volatilization of quantum dot components and improve the cut-off performance of the glass. However, if the content of ZnO is too high, it will reduce the crystallization performance of the glass and affect the transmittance performance of the glass. Therefore, the content of ZnO in the component is 8% to 30%, preferably 10% to 28%, and further preferably 12% to 25%.

[0069] In the present application, if the ratio of ZnO to SiO2, ZnO / SiO2, is too low, the cut-off performance of the glass cannot meet the design requirements. If the value of ZnO / SiO2 is too high, the crystallization performance and chemical stability of the glass will be poor. Therefore, ZnO / SiO2 is 0.1 to 1, preferably 0.2 to 0.8, and further preferably 0.3 to 0.7.

[0070] The present inventors have found that MgO, CaO, BaO and SrO can reduce the high temperature viscosity of the glass and improve the dissolution of quantum dot components in the glass, but if the content is too high, it will cause the crystallization performance and chemical stability of the glass to be poor. Therefore, in the present application, the sum of the contents of MgO, CaO, BaO and SrO, MgO+CaO+BaO+SrO, is 0 to 8%, preferably 0 to 6%, and more preferably 0 to 4%.

[0071] MgO can improve the chemical stability of the glass, but if the content is too high, the crystallization performance of the glass will be poor and the cut-off performance of the glass will not meet the design requirements. Therefore, the content of MgO is 0 to 2%, preferably 0 to 1.5%, and further preferably 0 to 1%.

[0072] CaO, BaO and SrO can improve the crystallization performance of the glass and reduce the high temperature viscosity of the glass, but if the content is too high, it will cause the chemical stability of the glass to be poor and interfere with the structure formation of the coloring substance, which will reduce the cut-off performance of the glass. Therefore, the content of CaO, BaO and SrO is all 0 to 2%, preferably 0 to 1.5%, and further preferably 0 to 1%.

[0073] CdS is one of the quantum dot components, which can cause the glass to cut off at 470nm to 500nm. In the present application, CdS mainly acts as a reducing agent, which can avoid the oxidation of quantum dot components Se 2- , Te 2- in the glass, and also provides the formation of quantum dot Cd 2+ . However, if the content of CdS is too high, it will cause the crystallization performance of the glass to be poor, and S has strong absorption in the near-infrared region, which will reduce the transmittance in the near-infrared region of the glass, so that the transmittance performance of the glass cannot meet the design requirements. Therefore, the content of CdS in the component is 1% to 10%, preferably 2% to 8%, and further preferably 2% to 6%.

[0074] Se is one of the quantum dot components in the glass of the present application, and forms CdSe quantum dot crystal in the glass 2+ The formation of CdSe quantum dot crystal can cause the glass to have a cutoff absorption of 500-680 nm. If the content of Se is too high, the glass will have poor crystallization performance, and the transmittance in the near infrared region will not meet the design requirements. Therefore, the content of Se is preferably 0.4-5%, more preferably 0.7-4%, and further preferably 0.8-3.5%. The content of Se in the present application refers to the content of all selenium-containing substances in the glass converted into elemental selenium. In the present application, Se is introduced in the form of elemental selenium and / or selenium-containing compounds.

[0075] Te is one of the quantum dot components in the glass of the present application, and forms CdTe quantum dot crystal in the glass 2+ The formation of CdTe quantum dot crystal can cause the glass to have a cutoff absorption of 500-830 nm. If Te is too high, it will enter the glass network structure, reducing the stability of the glass, and the transmittance in the near infrared region will not meet the design requirements. Therefore, the content of Te is preferably 0.5-5%, more preferably 0.7-4%, and further preferably 0.8-3%. The content of Te in the present application refers to the content of all selenium-containing substances in the glass converted into elemental tellurium. In the present application, Te is introduced in the form of elemental tellurium and / or tellurium-containing compounds.

[0076] It has been found through a large number of experimental studies that when the ratio of the contents of Se and Te, Se / Te, is too high, the cutoff wavelength of the glass is less than 650 nm, and the transmittance cannot meet the design requirements. Therefore, Se / Te is preferably less than 2.0, more preferably less than 1.5, and further preferably less than 1.

[0077] Further, when the sum of the contents of Se and Te, ∑(Se+Te), is too low relative to CdS, ∑(Se+Te) / CdS, the cutoff wavelength of the glass is less than 650 nm, and the transmittance cannot meet the design requirements. The ratio of the sum of the contents of Se and Te to CdS, ∑(Se+Te) / CdS, is greater than 0.05, preferably greater than 0.1, and more preferably ∑(Se+Te) / CdS is greater than 0.2.

[0078] Further, in the present application, when the thickness of the optical filter glass is 2 mm, the cutoff wavelength is greater than 600 nm, preferably greater than 650 nm, more preferably greater than 700 nm, and further preferably greater than 750 nm.

[0079] When the thickness of the optical filter glass is 2 mm, the transmittance at 850-900 nm is greater than 80%, preferably greater than 82%, and more preferably greater than 84%; the transmittance at 900-950 nm is greater than 85%, preferably greater than 86%, and more preferably greater than 87%; and the transmittance at 950-2000 nm is greater than 88%, preferably greater than 89%, and more preferably greater than 90%.

[0080] Further, in the present application, the acid resistance of the filter glass is Class 3 or above, preferably Class 2 or above, and further preferably Class 1; the water resistance of the filter glass is Class 3 or above, preferably Class 2 or above, and further preferably Class 1.

[0081] The Young's modulus of the filter glass is 61 GPa or above, preferably 63 GPa or above, and further preferably 64 GPa or above.

[0082] The expansion coefficient of the filter glass is 80x10 20-300℃ -7 / K or above, preferably 85x10 -7 / K or above, and more preferably 90x10 -7 / K or above.

[0083] Further, the present application also provides a preparation method of the filter glass according to the present application, which comprises the following steps:

[0084] The raw materials of the filter glass are mixed uniformly in proportion and put into a furnace at 1200-1400℃ for melting to form a molten glass.

[0085] The molten glass is subjected to homogenization treatment to eliminate bubbles in the glass.

[0086] The homogenized molten glass is cast or poured into a mold for forming to obtain a formed body.

[0087] The formed body is put into an annealing furnace for nucleation reaction at 550-700℃ for 24-72h, and then the temperature is raised to 550-700℃ for 12-72h to make the crystals in the glass grow, thereby obtaining a filter glass with special transmission.

[0088] In the present application, the raw materials of the filter glass can use composite salts (such as carbonates, phosphates, nitrates, etc.), and / or hydroxides, and / or oxides, and / or sulfides, and / or selenides, and / or fluorides, and / or simple substances, etc.

[0089] The present application also provides an optical element comprising the filter glass according to the present application. In the present application, the optical element can comprise a glass element and a glass preform.

[0090] ​Specifically, the glass preform can be produced using a means such as grinding processing, or a means such as re-hot press forming, precision press forming, or the like. That is, the glass preform can be produced by mechanically processing the glass through grinding and polishing, or by re-hot press forming a preform for press forming made of glass and then performing grinding processing, or by precision press forming a preform made by performing grinding processing. Note that the means for producing the glass preform is not limited to the above means.

[0091] Examples

[0092] The embodiments of the present application will be described in detail below with reference to Examples, but it will be understood by those skilled in the art that the following Examples are for illustrative purposes only and should not be construed as limiting the scope of the present application. When specific conditions are not mentioned in the Examples, conventional conditions or conditions recommended by the manufacturer are used. When the manufacturer of the reagent or instrument is not mentioned, it is a conventional product that can be obtained commercially.

[0093] Examples 1-21

[0094] The optical filter glasses of Examples 1-21 were produced according to the proportions in Table 1-3 by the following method.

[0095] 1) The raw materials of each component of the optical filter glass were mixed in proportion and uniformly put into a 1300°C furnace to be melted, forming a molten glass;

[0096] 2) The molten glass was stirred and homogenized to eliminate bubbles in the glass;

[0097] 3) The homogenized molten glass was cast or poured into a mold to form a shaped body;

[0098] 4) The shaped body was placed in an annealing furnace at 600°C for 30h to allow the glass to undergo nucleation, and then heated to 650°C for 20h to allow the crystals in the glass to grow, obtaining an optical filter glass having a special transmission.

[0099] Performance detection

[0100] 1. Cutoff performance

[0101] The 2mm glass sample was tested for the transmittance curve of 240nm-2000nm using a spectrometer according to the method of GB / T 7962.12-2010, and the wavelength at which the transmittance was 5% was taken as the cutoff wavelength. For the present application, the higher the numerical value of the cutoff wavelength, the better the cutoff performance of the glass, and the lower the numerical value of the cutoff wavelength, the worse the cutoff performance. The test results are shown in Table 1.

[0102] 2. Glass transmittance

[0103] 2mm glass sample according to GB / T 7962.12-2010 method using spectrometer to test the glass 240nm-2000nm transmittance curve, the present application near infrared transmittance refers to the 850nm-2000nm transmittance value. The present application described near infrared transmittance refers to the lowest transmittance in the corresponding waveband range, the detection results are shown in table 1.

[0104] 3, acid resistance stability

[0105] Glass acid resistance stability (D A ) (powder method) according to GB / T 17129 method for testing, the detection results are shown in table 1.

[0106] 4, water resistance stability

[0107] Glass water resistance stability (DW) (powder method) according to GB / T 17129 method for testing. In the present application, water resistance stability is sometimes referred to as water resistance or water stability, the detection results are shown in table 1.

[0108] 5, Young's modulus

[0109] Glass Young's modulus E according to GB / T 7962.6 method for testing, the detection results are shown in table 1.

[0110] 6, thermal expansion coefficient

[0111] The present application described thermal expansion coefficient refers to the glass 20-300℃ average thermal expansion coefficient, expressed as α 20-300℃ , according to GB / T 7962.16-2010 method for testing, the detection results are shown in table 1.

[0112] Table 1

[0113]

[0114] Table 2

[0115]

[0116] Table 3

[0117]

[0118] From the examples 1-21 can be seen, the thickness of the filter glass of the present application is 2mm, the cut-off wavelength is 600nm or more, the 850-900nm transmittance is 80% or more, the 900-950nm transmittance is 85% or more, the 950-2000nm transmittance is 88% or more. At the same time, the glass material also shows good chemical stability and mechanical properties.

[0119] It should be noted that although the technical solutions of the present application are described with specific examples, those skilled in the art can understand that the present application should not be limited thereto.

[0120] The above has described various embodiments of the present application, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles, practical application, or technical improvement in the market of the embodiments, or to enable other ordinary skilled in the art to understand the embodiments disclosed herein.

Claims

1. A filter glass, characterized in that, The following components are contained, expressed as a weight percentage: SiO2: 30%~70%; B2O3: 3%~20%; ZnO: 8~26%; CdS: 4~10%; Se: 0.4~5%; Te: 0.5~5%; Al2O3: 0.2~2%; The sum of the contents of Li2O, Na2O, and K2O (Li2O+Na2O+K2O) is 5%~28%; The sum of the contents of MgO, CaO, BaO and SrO (MgO+CaO+BaO+SrO) is 0~8%; The ratio of the sum of SiO2 and Al2O3 contents to the sum of B2O3, Li2O, Na2O and K2O contents, ∑(SiO2+Al2O3) / ∑(B2O3+Li2O+Na2O+K2O), by weight percentage, is 0.5~3.

0. By weight percentage, the ZnO / SiO2 ratio is 0.3 to 0.7, and the Se / Te ratio is less than or equal to 0.

8.

2. The filter glass according to claim 1, characterized in that, The following components are contained, expressed as a weight percentage: SiO2: 35%~68%; B2O3: 3%~15%; ZnO: 10~26%; CdS: 4~8%; Se: 0.7~4%; Te: 0.7~4%; Al2O3: 0.2~1%; The sum of the contents of Li2O, Na2O, and K2O (Li2O+Na2O+K2O) is 7%~23%; The sum of the contents of MgO, CaO, BaO and SrO is 0~6%.

3. The filter glass according to claim 2, characterized in that, The following components are contained, expressed as a weight percentage: SiO2: 38%~65%; B2O3: 5%~10%; ZnO: 12~26%; CdS: 4~6%; Se: 0.8~3.5%; Te: 0.8~3%; Al2O3: 0.2~0.5%; The sum of the contents of Li2O, Na2O, and K2O (Li2O+Na2O+K2O) is 9%~20%; The sum of the contents of MgO, CaO, BaO and SrO is 0~4% (MgO+CaO+BaO+SrO).

4. The filter glass according to any one of claims 1-3, characterized in that, By weight percentage, the filter glass contains 0-3% Li₂O, 2-9% Na₂O, 3-16% K₂O, and / or... By weight percentage, the filter glass contains 0-2% MgO, 0-2% CaO, 0-2% SrO, and 0-2% BaO.

5. The filter glass according to claim 4, characterized in that, By weight percentage, the filter glass contains 0-1% Li₂O, 3-8% Na₂O, 4-14% K₂O, and / or... By weight percentage, the filter glass contains 0-1.5% MgO, 0-1.5% CaO, 0-1.5% SrO, and 0-1.5% BaO.

6. The filter glass according to claim 5, characterized in that, By weight percentage, the filter glass contains no Li₂O; 4-8% Na₂O; 5-12% K₂O; and / or... By weight percentage, the filter glass contains 0-1% MgO, 0-1% CaO, 0-1% SrO, and 0-1% BaO.

7. The filter glass according to any one of claims 1-3, characterized in that, The ratio of the sum of SiO2 and Al2O3 content to the sum of B2O3, Li2O, Na2O and K2O content, ∑(SiO2+Al2O3) / ∑(B2O3+Li2O+Na2O+K2O), by weight percentage, is 0.8~2.

5.

8. The filter glass according to claim 7, characterized in that, The ratio of the sum of SiO2 and Al2O3 content to the sum of B2O3, Li2O, Na2O and K2O content, ∑(SiO2+Al2O3) / ∑(B2O3+Li2O+Na2O+K2O), by weight percentage, is 1~2.

2.

9. The filter glass according to any one of claims 1-3, characterized in that, The ratio of the sum of the contents of Se and Te to CdS, ∑(Se+Te) / CdS, is greater than 0.05 by weight percentage.

10. The filter glass according to claim 9, characterized in that, The ratio of the sum of the contents of Se and Te to CdS, ∑(Se+Te) / CdS, is greater than 0.1 by weight percentage.

11. The filter glass according to any one of claims 1-3, characterized in that, The ratio of the sum of the contents of Se and Te to CdS, ∑(Se+Te) / CdS, is greater than 0.2 by weight percentage.

12. The filter glass according to any one of claims 1-3, characterized in that, When the thickness of the filter glass is 2mm, its cutoff wavelength is above 600nm; When the thickness of the filter glass is 2mm, the transmittance of 850~900nm is above 80%, the transmittance of 900~950nm is above 85%, and the transmittance of 950~2000nm is above 88%.

13. The filter glass according to any one of claims 1-3, characterized in that, The filter glass has an acid resistance of Class 3 or above; the filter glass has a water resistance of Class 3 or above. The Young's modulus of the filter glass is above 61 GPa; The coefficient of thermal expansion α of the filter glass 20-300℃ 80×10 -7 / K or above.

14. A method for preparing a filter glass according to any one of claims 1-13, characterized in that, Includes the following steps: The various components of the glass raw materials are mixed evenly in proportion and then put into a furnace at 1200~1400℃ to melt and form molten glass. The molten glass is homogenized to eliminate air bubbles in the glass; The homogenized molten glass is poured or poured into a mold to form a shaped body. The molded body is placed in an annealing furnace and held at 550-700℃ for 24-72 hours to allow the glass to undergo a nucleation reaction. The temperature is then raised to 550-700℃ and held for 12-72 hours to allow the crystals in the glass to grow, thus obtaining the filter glass.

15. An optical element, characterized in that, Includes the filter glass according to any one of claims 1-13.

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