Composition for mid-infrared light transmitting glass and method for producing same

Abstract

To provide a composition for mid-infrared light transmitting glass that can be formed into a lens that has excellent optical properties and secures all of excellent physical properties, and a method for preparing the same.SOLUTION: A composition for glass allows passage of light in a mid-infrared wavelength band by a preset reference value or more, wherein the composition for glass includes preset contents of TeO2, BaO, ZnO and a dopant that changes optical properties of glass.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a glass composition that transmits light in the mid-infrared wavelength range and a method for producing the same. [Background technology]

[0002] The material described in this section is merely intended to provide background information regarding one embodiment of the present invention and may not constitute prior art.

[0003] Mid-infrared transmitting lenses have been mainly used in the military sector for image processing purposes such as missile tracking. Mid-infrared transmitting lenses used in the military sector must maintain excellent performance even in high-temperature environments, so they are manufactured by molding crystals such as germanium into the shape of a lens one by one. As a result, the material is expensive and the productivity is low, making it difficult for such military mid-infrared transmitting lenses to be used in the civilian sector.

[0004] Meanwhile, in the civilian sector, there is an increasing demand for external infrared lenses that can be attached to small devices such as smartphones. For this reason, conventional infrared-transmitting lenses have been made of chalcogenide materials and used in various fields that require infrared light to pass through.

[0005] However, chalcogenides can transmit mid-infrared (3μm~5μm) and far-infrared (15μm or more), so they are a possible material for mid-infrared transmitting lenses. However, chalcogenides have a significantly low glass transition temperature of about 350℃, so chalcogenide glass lenses cannot be used in industrial environments including blast furnaces, glass manufacturing plants, and high-temperature processes. In summary, infrared transmitting lenses made of chalcogenide materials can operate smoothly in normal temperature environments, but in high-temperature environments of several hundred degrees Celsius or more, the lens shape and optical characteristics change significantly and they cannot operate smoothly. For example, in factories and blast furnaces that process high-temperature materials, infrared transmitting lenses made of conventional expensive crystalline materials must be used due to the above-mentioned characteristics. For this reason, mid-infrared cameras, which have a relatively high resolution compared to far-infrared cameras, have only been used in military applications, and it has been difficult to expand the market to the civilian market.

[0006] Therefore, there is a great demand for mid-infrared transmitting lenses that can replace existing Ge, ZnS, ZnSe or crystalline materials and are relatively inexpensive and easy to mass-produce by applying a molding process so that they can be applied in various environments in the civilian sector. Summary of the Invention [Problem to be solved by the invention]

[0007] An object of one embodiment of the present invention is to provide a composition for mid-infrared light transmitting glass that can be manufactured into a lens that has excellent optical properties and at the same time ensures all of the excellent physical properties, and a method for manufacturing the same.

[0008] Another object of one embodiment of the present invention is to provide a composition for mid-infrared light transmitting glass that has excellent optical and physical properties and can be mass-produced into lenses, and a method for producing the same. [Means for solving the problem]

[0009] According to one aspect of the present invention, there is provided a glass composition that transmits light in the mid-infrared wavelength band at a predetermined standard value or more, the glass composition containing TeO2, La2O3 and ZnO in predetermined amounts.

[0010] According to one aspect of the present invention, the glass composition is characterized in that it contains 55 to 80 mol % of TeO2, 5 to 10 mol % of La2O3, and 10 to 40 mol % of ZnO.

[0011] According to one aspect of the present invention, there is provided a glass composition that transmits light in the mid-infrared wavelength band at a predetermined reference value or more, the glass composition containing TeO2, La2O3 and BaO in predetermined amounts.

[0012] According to one aspect of the present invention, the glass composition is characterized in that it contains 70 to 80 mol % of TeO2, 10 mol % of La2O3, and 10 to 20 mol % of BaO.

[0013] According to one aspect of the present invention, there is provided a glass composition that transmits light in the mid-infrared wavelength band at a predetermined reference value or more, the glass composition containing TeO2, BaO and ZnO in predetermined amounts.

[0014] According to one aspect of the present invention, the glass composition is characterized in that it contains 50 to 70 mol % of TeO2, 5 to 20 mol % of BaO, and 20 to 30 mol % of ZnO.

[0015] According to one aspect of the present invention, there is provided a glass composition that transmits light in the mid-infrared wavelength band at a predetermined reference value or more, the glass composition comprising TeO2, ZnO, La2O3, and a dopant for varying the optical properties of the glass, each in a predetermined content.

[0016] According to one aspect of the present invention, the dopant is Nb2O3, MoO3 or ZnF2.

[0017] According to one aspect of the present invention, the glass composition is characterized by containing 65 to 70 mol % of TeO2, 5 to 20 mol % of ZnO, 10 mol % of La2O3, and 5 to 15 mol % of the dopant.

[0018] According to one aspect of the present invention, there is provided a glass composition that transmits light in the mid-infrared wavelength band at a predetermined reference value or more, the glass composition comprising TeO2, BaO, ZnO, and a dopant for varying the optical properties of the glass, each in a predetermined content.

[0019] According to one aspect of the present invention, the dopant is Nb2O3 or MoO3.

[0020] According to one aspect of the present invention, the glass composition contains 60 mol % of TeO2, 10 mol % of BaO, 20 to 25 mol % of ZnO, and 5 to 10 mol % of the dopant.

[0021] According to one aspect of the present invention, there is provided a glass composition that transmits light in the mid-infrared wavelength band at a predetermined reference value or more, the glass composition comprising TeO2, BaO, La2O3, and a dopant for varying the optical properties of the glass, each in a predetermined content.

[0022] According to one aspect of the present invention, the dopant is Nb2O3 or MoO3.

[0023] According to one aspect of the present invention, the glass composition contains 70 mol % of TeO2, 5 to 15 mol % of BaO, 10 mol % of La2O3, and 5 to 15 mol % of the dopant.

[0024] According to one aspect of the present invention, there is provided a method for producing a glass composition that transmits light in the mid-infrared wavelength band at a predetermined reference value or more, the method comprising: a mixing process for mixing predetermined raw materials including TeO2 in predetermined contents; a melting process for melting the material mixed in the mixing process at a first predetermined temperature for a first predetermined time; and an annealing process for annealing the material melted in the melting process in a mold in a first predetermined environment.

[0025] According to one aspect of the present invention, the method for producing a composition for glass further includes an exposure process of charging the materials mixed in the mixing process into a predetermined container and exposing them to a second predetermined environment for a second predetermined time.

[0026] According to one aspect of the present invention, the predetermined raw materials include any two of La2O3, BaO, and ZnO. Effect of the Invention

[0027] As described above, one aspect of the present invention has the advantage that it is possible to manufacture a lens that has excellent optical characteristics while at the same time ensuring all of the excellent physical characteristics.

[0028] Furthermore, according to one aspect of the present invention, there is an advantage in that mass productivity can be ensured when the composition for mid-infrared light transmitting glass is produced into a lens. [Brief description of the drawings]

[0029] [Figure 1] 1 is a flowchart showing a method for manufacturing a composition for mid-infrared light transmitting glass according to an embodiment of the present invention. [Diagram 2] 1 is a three-component system showing the contents of components constituting a mid-infrared light transmitting glass composition according to a first embodiment of the present invention. [Diagram 3] 1 is a diagram showing a mid-infrared light transmitting glass according to a first embodiment of the present invention. [Figure 4]2 is a graph showing the wavelength-dependent transmittance of a composition for mid-infrared light transmitting glass according to a first embodiment of the present invention. [Diagram 5] 1 is a graph showing glass transition temperature, peak temperature, and thermal stability according to the composition of a mid-infrared light transmitting glass composition according to a first embodiment of the present invention. [Figure 6] 1 is a graph showing glass transition temperatures and softening temperatures according to compositions of mid-infrared light transmitting glass compositions according to a first embodiment of the present invention. [Figure 7] 4 is a graph showing hardness depending on the composition of the mid-infrared light transmitting glass composition according to the first embodiment of the present invention. [Figure 8] 4 is a three-component system showing the contents of components constituting a mid-infrared light transmitting glass composition according to a second embodiment of the present invention. [Figure 9] FIG. 1 is a diagram showing a mid-infrared light transmitting glass according to a second embodiment of the present invention. [Figure 10] 4 is a graph showing the wavelength-dependent transmittance of a composition for mid-infrared light transmitting glass according to a second embodiment of the present invention. [Figure 11] 5 is a graph showing the glass transition temperature, peak temperature, and thermal stability according to the composition of a mid-infrared light transmitting glass composition according to a second embodiment of the present invention. [Figure 12] 5 is a graph showing the glass transition temperature and the softening temperature according to the composition of the mid-infrared light transmitting glass composition according to the second embodiment of the present invention. [Figure 13] 1 is a graph showing hardness depending on the composition of a mid-infrared light transmitting glass composition according to a second embodiment of the present invention. [Figure 14] FIG. 11 is a diagram showing the contents of components constituting a mid-infrared light transmitting glass composition according to a third embodiment of the present invention. [Figure 15] FIG. 13 is a diagram showing a mid-infrared light transmitting glass according to a third embodiment of the present invention. [Figure 16] 1 is a graph showing the glass transition temperature, crystallization temperature, and thermal stability according to the composition of a mid-infrared light transmitting glass composition according to a third embodiment of the present invention. [Figure 17]10 is a graph showing the glass transition temperature and the softening temperature according to the composition of a mid-infrared light transmitting glass composition according to a third embodiment of the present invention. [Figure 18] FIG. 11 is a diagram showing the contents of components constituting a mid-infrared light transmitting glass composition according to a fourth embodiment of the present invention. [Figure 19] FIG. 13 is a diagram showing a mid-infrared light transmitting glass according to a fourth embodiment of the present invention. [Figure 20] FIG. 13 is a diagram showing the contents of components constituting a mid-infrared light transmitting glass composition according to a fifth embodiment of the present invention. [Figure 21] FIG. 13 is a diagram showing a mid-infrared light transmitting glass according to a fifth embodiment of the present invention. [Figure 22] 10 is a graph showing the wavelength-dependent transmittance of a composition for mid-infrared light transmitting glass according to a fifth embodiment of the present invention. [Diagram 23] FIG. 13 is a diagram showing the contents of components constituting a mid-infrared light transmitting glass composition according to a sixth embodiment of the present invention. [Figure 24] FIG. 13 is a diagram showing a mid-infrared light transmitting glass according to a sixth embodiment of the present invention. [Diagram 25] 13 is a graph showing the wavelength-dependent transmittance of a mid-infrared light transmitting glass composition according to a sixth embodiment of the present invention. [Figure 26] 13 is a graph showing the glass transition temperature, crystallization temperature, and thermal stability according to the composition of a mid-infrared light transmitting glass composition according to a sixth embodiment of the present invention. [Figure 27] 13 is a graph showing the glass transition temperature and the softening temperature according to the composition of a mid-infrared light transmitting glass composition according to the sixth embodiment of the present invention. [Figure 28] 13 is a graph showing the thermal expansion coefficient depending on the composition of a mid-infrared light transmitting glass composition according to a sixth embodiment of the present invention. [Figure 29] FIG. 13 is a diagram showing the contents of components constituting a mid-infrared light transmitting glass composition according to a seventh embodiment of the present invention. [Diagram 30] FIG. 13 is a diagram showing a mid-infrared light transmitting glass according to a seventh embodiment of the present invention. [Diagram 31]FIG. 13 is a diagram showing the contents of components constituting a mid-infrared light transmitting glass composition according to an eighth embodiment of the present invention. [Diagram 32] FIG. 13 is a diagram showing a mid-infrared light transmitting glass according to an eighth embodiment of the present invention. [Diagram 33] 13 is a graph showing the glass transition temperature, crystallization temperature, and thermal stability according to the composition of a mid-infrared light transmitting glass composition according to an eighth embodiment of the present invention. [Diagram 34] 13 is a graph showing the glass transition temperature and the softening temperature according to the composition of a mid-infrared light transmitting glass composition according to the eighth embodiment of the present invention. [Diagram 35] 13 is a graph showing the thermal expansion coefficient depending on the composition of a mid-infrared light transmitting glass composition according to an eighth embodiment of the present invention. [Diagram 36] FIG. 13 is a diagram showing the contents of components constituting a mid-infrared light transmitting glass composition according to a ninth embodiment of the present invention. [Figure 37] FIG. 13 is a diagram showing a mid-infrared light transmitting glass according to a ninth embodiment of the present invention. [Figure 38] FIG. 23 is a diagram showing the contents of components constituting a mid-infrared light transmitting glass composition according to a tenth embodiment of the present invention. [Figure 39] FIG. 17 is a diagram showing a mid-infrared light transmitting glass according to a tenth embodiment of the present invention. [Diagram 40] 13 is a graph showing the glass transition temperature, crystallization temperature, and thermal stability according to the composition of a mid-infrared light transmitting glass composition according to a tenth embodiment of the present invention. [Diagram 41] 13 is a graph showing the glass transition temperature and softening temperature depending on the composition of a mid-infrared light transmitting glass composition according to a tenth embodiment of the present invention. [Diagram 42] 13 is a graph showing the thermal expansion coefficient depending on the composition of a mid-infrared light transmitting glass composition according to a tenth embodiment of the present invention. [Diagram 43] FIG. 15 is a diagram showing the contents of components constituting a mid-infrared light transmitting glass composition according to an eleventh embodiment of the present invention. [Diagram 44] 13 is a graph showing the wavelength-dependent transmittance of a mid-infrared light transmitting glass composition according to an eleventh embodiment of the present invention. [Diagram 45]13 is a graph showing the glass transition temperature, crystallization temperature, and thermal stability according to the composition of a mid-infrared light transmitting glass composition according to an eleventh embodiment of the present invention. [Diagram 46] 13 is a graph showing refractive indexes depending on the compositions of mid-infrared light transmitting glass compositions according to an eleventh embodiment of the present invention. [Figure 47] FIG. 23 is a diagram showing the contents of components constituting a mid-infrared light transmitting glass composition according to a twelfth embodiment of the present invention. [Figure 48] 14 is a graph showing the wavelength-dependent transmittance of a composition for mid-infrared light transmitting glass according to a twelfth embodiment of the present invention. [Figure 49] 13 is a graph showing the glass transition temperature, crystallization temperature, and thermal stability according to the composition of a mid-infrared light transmitting glass composition according to the twelfth embodiment of the present invention. [Figure 50] 13 is a graph showing the refractive index depending on the composition of a mid-infrared light transmitting glass composition according to a twelfth embodiment of the present invention. [Figure 51] 13 is a graph showing hardness depending on the composition of a mid-infrared light transmitting glass composition according to the twelfth embodiment of the present invention. [Figure 52] FIG. 23 is a diagram showing the contents of components constituting a mid-infrared light transmitting glass composition according to a thirteenth embodiment of the present invention. [Figure 53] 13 is a graph showing the wavelength-dependent transmittance of a mid-infrared light transmitting glass composition according to a thirteenth embodiment of the present invention. [Figure 54] 13 is a graph showing the glass transition temperature, crystallization temperature, and thermal stability according to the composition of a mid-infrared light transmitting glass composition according to the thirteenth embodiment of the present invention. [Figure 55] 13 is a graph showing the refractive index depending on the composition of a mid-infrared light transmitting glass composition according to a thirteenth embodiment of the present invention. [Figure 56] FIG. 23 is a diagram showing the contents of components constituting a mid-infrared light transmitting glass composition according to a fourteenth embodiment of the present invention. [Figure 57] 23 is a graph showing the wavelength-dependent transmittance of a composition for mid-infrared light transmitting glass according to a fourteenth embodiment of the present invention. [Figure 58]15 is a graph showing the glass transition temperature, crystallization temperature, and thermal stability according to the composition of a mid-infrared light transmitting glass composition according to the fourteenth embodiment of the present invention. [Figure 59] 23 is a graph showing hardness depending on the composition of a mid-infrared light transmitting glass composition according to the fourteenth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] Although the present invention can be modified in various ways and has various embodiments, a specific embodiment will be illustrated in the drawings and described in detail. However, it is not intended to limit the present invention to the specific embodiment, and it should be understood that the present invention includes all modifications, equivalents, and alternatives within the spirit and technical scope of the present invention. In describing each drawing, similar reference numerals are used for similar components.

[0031] Terms such as first, second, A, B, etc. are used to describe various components, but the components should not be limited by the terms. The terms are used only to distinguish one component from another. For example, a first component may be named a second component, and similarly, a second component may be named a first component, without departing from the scope of the invention. The term and / or includes a combination of multiple associated listed items or any item of multiple associated listed items.

[0032] When a component is said to be "coupled" or "connected" to another component, it should be understood that it may be directly coupled or connected to the other component, but that there may be other components in between. In contrast, when a component is said to be "directly coupled" or "directly connected" to another component, it should be understood that there are no other components in between.

[0033] The terms used in this application are merely used to describe specific embodiments and are not intended to limit the present invention. A singular expression includes a plural expression unless the context clearly indicates otherwise. In this application, it should be understood that terms such as "include" or "have" do not preclude the possibility of the presence or addition of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification.

[0034] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0035] Terms defined in commonly used dictionaries should be construed to have a meaning consistent with the meaning they have in the context of the relevant art, and not to be construed in an idealized or overly formal sense unless expressly defined in this application.

[0036] In addition, the configurations, processes, steps, or methods included in each embodiment of the present invention may be shared within a scope that is not technically inconsistent with each other.

[0037] FIG. 1 is a flow chart showing a method for producing a mid-infrared light transmitting glass composition according to one embodiment of the present invention.

[0038] The composition for glass is manufactured into mid-infrared light transmitting glass through the manufacturing process described below. The mid-infrared light transmitting glass has a transmittance equal to or higher than a predetermined reference value, particularly for light in the mid-infrared wavelength band among incident light. The mid-infrared light transmitting glass can be used in various forms not only in the military field but also in the civilian field, such as in an environment where chemical gas, fog, or sea fog is thick and it is difficult to identify objects with the naked eye, or in an environment where it is necessary to monitor whether a high-temperature object is leaking, such as a factory or a blast furnace. In this case, in order to use the mid-infrared light transmitting glass in various fields, it can be used as glass itself, but it is more often formed into optical parts such as lenses and used. For this reason, the compositions for mid-infrared light transmitting glass according to one embodiment of the present invention are mixed in a predetermined ratio and then subjected to the manufacturing process described below, so that mid-infrared light transmitting lenses having excellent optical properties and excellent physical properties can be mass-produced.

[0039] The predetermined raw materials are mixed together in predetermined amounts (S110).

[0040] The raw materials constituting the glass composition include a main component and a dopant. The main component is a component that must be included in order for the raw materials to be manufactured into a mid-infrared light transmitting glass composition or a mid-infrared light transmitting glass. TeO2 is included as a main component, and any two of ZnO, BaO, and La2O3 are included selectively. The content of each main component varies depending on the selected component. When TeO2, La2O3, and ZnO are included as main components, TeO2 is included in the range of 55 to 80 mol%, La2O3 is included in the range of 5 to 10 mol%, and ZnO is included in the range of 10 to 40 mol%, respectively. When TeO2, La2O3, and BaO are included as main components, TeO2 is included in the range of 70 to 80 mol%, La2O3 is included in only 10 mol%, and BaO is included in the range of 10 to 20 mol%, respectively. When TeO2, BaO and ZnO are included as main components, TeO2 is included within the range of 50-70 mol%, BaO is included only within the range of 5-20 mol%, and ZnO is included within the range of 20-30 mol%. By including the selected components as the main components of the raw materials according to the above-mentioned contents, it is possible to ensure a glass-forming region. Furthermore, when the contents of the selected components are appropriately adjusted, the finally manufactured mid-infrared lens can ensure optical properties such as excellent mid-infrared light transmittance, thermal stability, or refractive index. As the refractive index increases, the mid-infrared lens can be designed to have a thinner thickness, and can be manufactured into an optical system with a thinner structure. Furthermore, the depth (shape) of the lens surface can be designed to be smaller, and the lens manufacturing yield can be improved.

[0041] As the raw material constituting the glass composition, a dopant is additionally included in addition to the main component. The dopant is a component that allows the glass to additionally have desired physical properties, such as hardness, without impairing the optical properties of the mid-infrared light transmitting lens to be manufactured. The dopant includes any one of ZnF2, MoO3, and Nb2O3. Depending on the components selected as the main components and the contents of each component, an appropriate dopant is selected and added in an appropriate content. When an appropriate dopant is selected and added in an appropriate content, the optical properties of the mid-infrared light transmitting lens to be manufactured are not impaired, and the desired physical properties of the glass can be improved.

[0042] Each raw material including the main component or the main component and the dopant is mixed. A ball mill can be used for mixing. Each raw material is placed in a container, for example, a Nalgene bottle, and mixed by zirconia balls having a certain amount of material and a certain volume. The raw materials can go through the above-mentioned mixing process and are mixed for a predetermined time (for example, 1 hour).

[0043] The mixed ingredients are loaded into a container and exposed to a first predetermined environment for a first predetermined time (S120).

[0044] The raw materials mixed by the above-mentioned process are charged into a predetermined container. Here, the predetermined container may be a platinum crucible having a size equal to or larger than a standard value. In particular, the platinum crucible has a size equal to or larger than a standard value, for example, 2,000 cc. When the raw materials are manufactured into a glass composition or glass, the manufactured glass particles must be larger than a certain size (bulk-up) to have an excellent yield when the glass is molded into an optical component. However, when the mixed raw materials are loaded into a container having a size equal to or smaller than a certain standard value (size) and undergo the process described below, the manufactured glass particles become excessively fine. The glass composition or glass manufactured in this way is not suitable for molding into an optical component, so the mixed materials are loaded into a predetermined container.

[0045] After the mixed materials are charged into the container, they are exposed to a first predetermined environment for a first predetermined time. The first predetermined environment can have a temperature of about 300° C. under a nitrogen atmosphere. For example, such an environment is formed by mounting a container (platinum crucible) in which the raw materials are charged into an electric furnace in a nitrogen atmosphere. In this way, the raw materials are exposed to the first predetermined environment, and surface water is removed. The OH group contained in the raw materials has a property of absorbing light in the mid-infrared wavelength band, causing a problem of reducing the mid-infrared transmittance of the manufactured glass or optical components molded therefrom. For this reason, the raw materials charged into the container are exposed to the first predetermined environment, and the OH group in the raw materials is removed. In order to sufficiently remove the OH group in the raw materials, the raw materials are exposed to the first predetermined environment for a first predetermined time (for example, 1 hour).

[0046] The mixed material is melted at a first predetermined temperature for a second predetermined time (S130). The material that has undergone a surface water removal process is melted at the first predetermined temperature, for example, about 900° C., for a second predetermined time, for example, 2 to 4 hours.

[0047] The molten material is formed into a mold and then annealed in a second predetermined environment (S140). The molten material is cast into a mold and then undergoes a forming process such as pressing. The material that has undergone the forming process is annealed in a second predetermined environment to manufacture a mid-infrared light transmitting glass. At this time, the molten material is vitrified through a quenching process, but internal stress occurs during the quenching process. The molten material is annealed in a second predetermined environment to relieve the stress. Here, the second predetermined environment has a temperature that is a predetermined temperature (e.g., 10 to 20 degrees or more) higher than the glass transition temperature (Tg) of the main material contained in the raw material. The molten material is annealed from the temperature of the second predetermined environment to room temperature to manufacture a composition for mid-infrared light transmitting glass or mid-infrared light transmitting glass.

[0048] FIG. 2 is a three-component system showing the contents of components constituting the mid-infrared light transmitting glass composition according to the first embodiment of the present invention.

[0049] The mid-infrared light transmitting glass composition according to the first embodiment of the present invention (hereinafter, abbreviated as "first composition") is manufactured by using TeO2, La2O3, and ZnO as raw materials. To manufacture the first composition, TeO2, La2O3, and ZnO are contained in the following amounts, respectively. 1)TeO2:80mol%, La2O3:10mol%, ZnO:10mol% 2)TeO2:70mol%, La2O3:10mol%, ZnO:20mol% 3)TeO2:60mol%, La2O3:10mol%, ZnO:30mol% 4)TeO2:55mol%, La2O3:5mol%, ZnO:40mol%

[0050] In producing each of the first compositions, the content of ZnO was varied, and along with the change in the content of ZnO, the contents of TeO2 or both of TeO2 and La2O3 were varied.

[0051] The glass realized with the first composition containing the above-mentioned amounts of each raw material is shown in FIG.

[0052] FIG. 3 is a diagram showing a mid-infrared light transmitting glass according to a first embodiment of the present invention.

[0053] 3(a) to (d) show glasses realized from each of the first compositions. Referring to FIG. 3(a) to (d), it was confirmed that no crystallization occurred in any of the first compositions when they were realized into glass.

[0054] 4 is a graph showing the transmittance by wavelength of the composition for mid-infrared light transmitting glass according to the first embodiment of the present invention. The transmittance of the first composition and the compositions mentioned below were measured by an FTIR / UV-VIS Spectrometer.

[0055] Each of the first compositions has a light transmittance as shown in the graph of FIG. 4. Here, each of the first compositions exhibits a high transmittance of 70% or more on average in the mid-infrared wavelength band of 3 to 5 μm. Therefore, each of the first compositions has properties suitable for realizing mid-infrared light transmitting glass. Furthermore, glass realized with each of the first compositions has excellent release properties and can be anti-reflection coated on the surface. When anti-reflection coating is applied to the surface of glass realized with each of the first compositions, better mid-infrared light transmittance can be ensured.

[0056] 5 is a graph showing the glass transition temperature, peak temperature, and thermal stability according to the composition for mid-infrared light transmitting glass according to the first embodiment of the present invention. The glass transition temperature and peak temperature of the first composition and the compositions mentioned below were measured by TG-DTA (STA409PC, NETZSCH) using a powder test piece size.

[0057] Thermal stability is determined by the crystallization temperature (T x ) and glass transition temperature (T g ) and is a factor that can determine whether crystallization will occur when the manufactured glass is molded into an optical component. After being reheated and softened, the glass is cooled into the desired shape (e.g., lens shape) through molding, etc., and molded into an optical component. During this process, if the composition that forms the glass has low thermal stability, the glass will crystallize during the process of softening and cooling. Crystallization causes the incident light to disperse, reducing the transmittance of the glass.

[0058] Therefore, only when the thermal stability is high can the glass realized by the composition have excellent optical properties without crystallization when molded into optical components, and can also be excellent in mass production. Generally, if the thermal stability is 100°C or higher, crystallization does not occur well during molding into optical components, and the composition is considered to have thermal stability. Furthermore, if the thermal stability is 130°C or higher, the composition is considered to have very good thermal stability.

[0059] However, if the crystallization temperature is not clear during thermal analysis of the composition, the peak temperature (T p The difference between the viscosity and the glass transition temperature is used to evaluate the thermal stability between the relative compositions.

[0060] 5, the lower the ZnO content in the first composition, the higher the thermal stability (calculated using the difference between the peak temperature and the glass transition temperature). In particular, when the composition contains 20 mol% or less of ZnO, it was confirmed that the composition has excellent thermal stability of 150°C or more.

[0061] FIG. 6 is a graph showing the glass transition temperature and the softening temperature according to the composition of the mid-infrared light transmitting glass composition according to the first embodiment of the present invention.

[0062] The softening temperature is the temperature at which the solid glass (first composition) begins to deform and soften due to heat in order to mold the glass (composition for glass). If the softening temperature of the composition is excessively high, it may be difficult to mold the glass realized from the composition for glass into an optical component. This reduces the mass productivity of the glass as an optical component. In addition, if the softening temperature is excessively high, crystallization may progress in the glass during the process of softening the glass by applying heat for molding. Therefore, it is preferable that the composition for glass has a softening temperature equal to or lower than a certain reference value. Here, the reference value may be 520°C.

[0063] Referring to the graph shown in FIG. 6, it was confirmed that regardless of the amount of ZnO contained in the first composition, all of the compositions had a softening temperature significantly lower than the reference value. In particular, when the composition contained 20 mol % or less of ZnO or only 40 mol %, the composition had a relatively lower softening temperature.

[0064] 7 is a graph showing hardness depending on the composition of the mid-infrared light transmitting glass composition according to the first embodiment of the present invention. The hardness of the first composition and the compositions mentioned below were measured using a micro Vickers hardness tester (Mitutoyo, HM-220B).

[0065] 7, the glass realized with the first composition has a tendency to have a higher hardness as the ZnO content increases. It can be seen that the glass has the highest hardness when the ZnO content is 30 mol%, and the glass realized with the first composition has a hardness of 335 KgF / mm 2 It was confirmed that the hardness was equal to or higher than that of the conventional hardness test pieces.

[0066] When each of the first compositions is contained in the above-mentioned amounts and manufactured into glass, it was confirmed that excellent optical properties and physical properties are ensured, as described with reference to FIGS. 4 to 7.

[0067] FIG. 8 is a three-component system showing the contents of components constituting a mid-infrared light transmitting glass composition according to a second embodiment of the present invention.

[0068] A mid-infrared light transmitting glass composition according to a second embodiment of the present invention (hereinafter, abbreviated as "second composition") is manufactured by using TeO2, La2O3, and BaO as raw materials. For manufacturing the second composition, TeO2, La2O3, and BaO are contained in the following amounts, respectively. 1)TeO2:80mol%, La2O3:10mol%, BaO:10mol% 2)TeO2:70mol%, La2O3:10mol%, BaO:20mol%

[0069] In producing each of the second compositions, the BaO content was varied, and the TeO2 content was also varied in accordance with the change in the BaO content.

[0070] The glass realized with the second composition containing the above-mentioned amounts of each raw material is shown in FIG.

[0071] FIG. 9 is a diagram showing a mid-infrared light transmitting glass according to a second embodiment of the present invention.

[0072] 9(a) and (b) show the glasses realized from each of the second compositions. Referring to FIG. 9(a) and (b), it was confirmed that no crystallization occurred in any of the second compositions when they were realized into glasses.

[0073] FIG. 10 is a graph showing the transmittance by wavelength of the mid-infrared light transmitting glass composition according to the second embodiment of the present invention.

[0074] Each of the second compositions has a light transmittance as shown in the graph of FIG. 10. Here, each of the second compositions exhibited a high transmittance of 72% or more on average in the mid-infrared wavelength band of 3 to 5 μm. Therefore, each of the second compositions has properties suitable for realizing mid-infrared light transmitting glass. Furthermore, the glass realized with each of the second compositions has excellent release properties and can be anti-reflective coated on the surface. When the surface of the glass realized with each of the second compositions is anti-reflective coated, the glass can ensure a mid-infrared light transmittance equal to or higher than the above-mentioned transmittance.

[0075] FIG. 11 is a graph showing the glass transition temperature, peak temperature, and thermal stability depending on the composition of the mid-infrared light transmitting glass composition according to the second embodiment of the present invention.

[0076] 11, it was confirmed that the second compositions all had thermal stability of 100° C. or more, regardless of the BaO content. In particular, the higher the BaO content in the second composition, the higher the thermal stability of the composition.

[0077] FIG. 12 is a graph showing the glass transition temperature and the softening temperature according to the composition of the mid-infrared light transmitting glass composition according to the second embodiment of the present invention.

[0078] 12, it was confirmed that regardless of the content of BaO in the second composition, all compositions had a softening temperature significantly lower than the reference value (550°C). The lower the content of BaO in the second composition, the lower the softening temperature of the composition.

[0079] FIG. 13 is a graph showing hardness depending on the composition of the mid-infrared light transmitting glass composition according to the second embodiment of the present invention.

[0080] 13, the glass realized with the second composition has a tendency to have a higher hardness as the BaO content decreases. Regardless of the content, the glass realized with the second composition has a hardness of 320 KgF / mm 2 It was confirmed that the hardness was equal to or higher than that of the conventional hardness test pieces. When each of the second compositions is contained in the above-mentioned amounts and manufactured into glass, it has been confirmed that excellent optical properties and physical properties are ensured, as described with reference to FIGS. 10 to 13.

[0081] FIG. 14 is a diagram showing the contents of components constituting a mid-infrared light transmitting glass composition according to a third embodiment of the present invention.

[0082] A mid-infrared light transmitting glass composition according to a third embodiment of the present invention (hereinafter, abbreviated as "third composition") is prepared by using TeO2, BaO, and ZnO as raw materials. To prepare the third composition, TeO2, BaO, and ZnO are contained in the following amounts, respectively. 1)TeO2:65mol%, BaO:5mol%, ZnO:30mol% 2)TeO2:60mol%, BaO:10mol%, ZnO:30mol% 3)TeO2:55mol%, BaO:15mol%, ZnO:30mol% 4)TeO2:50mol%, BaO:20mol%, ZnO:30mol% 5)TeO2:70mol%, BaO:10mol%, ZnO:20mol%

[0083] In producing each of the third compositions, the ZnO content was varied in the range of 20 to 30 mol%, and the TeO2 content was varied in the range of 50 to 70 mol%, and the La2O3 content was varied in the range of 5 to 20 mol% in accordance with the change in the ZnO content. However, when the ZnO content was reduced to 10 mol%, crystallization occurred during the glass manufacturing process.

[0084] The glass realized with the third composition containing the above-mentioned amounts of each raw material is shown in FIG.

[0085] FIG. 15 is a diagram showing a mid-infrared light transmitting glass according to a third embodiment of the present invention.

[0086] (a) to (e) in Figure 3 show glasses realized from each of the third compositions. With reference to (a) to (e) in Figure 3, it was confirmed that no crystallization occurred in any of the third compositions when they were realized into glass.

[0087] FIG. 16 is a graph showing the glass transition temperature, crystallization temperature, and thermal stability according to the composition of the mid-infrared light transmitting glass composition according to the third embodiment of the present invention.

[0088] 16, it can be seen that the third composition has a thermal stability of 100° C. or more regardless of the BaO content. In particular, the higher the BaO content in the third composition, the higher the thermal stability of the composition.

[0089] FIG. 17 is a graph showing the glass transition temperature and the softening temperature according to the composition of the mid-infrared light transmitting glass composition according to the third embodiment of the present invention.

[0090] 17, it can be seen that regardless of the content of BaO in the third composition, all of them have a softening temperature significantly lower than the reference value (550°C). The lower the content of BaO in the third composition, the lower the softening temperature.

[0091] FIG. 18 is a diagram showing the contents of components constituting a mid-infrared light transmitting glass composition according to a fourth embodiment of the present invention.

[0092] A composition for mid-infrared light transmitting glass according to a fourth embodiment of the present invention (hereinafter, abbreviated as "fourth composition") is prepared by using TeO2, BaO, and WO3 as raw materials. To prepare the fourth composition, TeO2, BaO, and WO3 are contained in the following amounts, respectively. 1)TeO2:80mol%, BaO:10mol%, WO3:10mol% 2)TeO2:70mol%, BaO:10mol%, WO3:20mol% 3)TeO2:60mol%, BaO:10mol%, WO3:30mol%

[0093] In producing each of the fourth compositions, the content of WO3 was varied, and the content of TeO2 was also varied in accordance with the change in the content of WO3. However, when the content of WO3 exceeded 30 mol% or the content of BaO exceeded 10 mol%, crystallization occurred during the glass production process.

[0094] The glass realized with the fourth composition containing the above-mentioned amounts of each raw material is shown in FIG.

[0095] FIG. 19 is a diagram showing a mid-infrared light transmitting glass according to a fourth embodiment of the present invention.

[0096] (a) to (c) in Fig. 19 show glasses realized from each of the fourth compositions. With reference to (a) to (c) in Fig. 19, it was confirmed that no crystallization occurred in any of the fourth compositions when they were realized into glass.

[0097] FIG. 20 is a diagram showing the contents of components constituting a mid-infrared light transmitting glass composition according to a fifth embodiment of the present invention.

[0098] A mid-infrared light transmitting glass composition according to a fifth embodiment of the present invention (hereinafter, abbreviated as "fifth composition") is prepared by including TeO2, ZnO, and La2O3 as main materials and MoO3 as a dopant. To prepare the fifth composition, TeO2, ZnO, La2O3, and MoO3 are included in the following ratio of 70:(20-x):10:x, respectively. 1)TeO2:70mol%, ZnO:15mol%, La2O3:10mol%, MoO3:5mol% 2)TeO2:70mol%, ZnO:10mol%, La2O3:10mol%, MoO3:10mol% 3)TeO2:70mol%, ZnO:5mol%, La2O3:10mol%, MoO3:15mol%

[0099] In producing each of the fifth compositions, the content of MoO3 was varied, and the content of ZnO was also varied in accordance with the change in the content of MoO3.

[0100] FIG. 21 is a diagram showing a mid-infrared light transmitting glass according to a fifth embodiment of the present invention.

[0101] (a) to (c) in Fig. 21 show glasses realized from each of the fifth compositions. With reference to (a) to (c) in Fig. 21, it was confirmed that no crystallization occurred in any of the fifth compositions when they were realized into glass.

[0102] FIG. 22 is a graph showing the transmittance by wavelength of a mid-infrared light transmitting glass composition according to the fifth embodiment of the present invention.

[0103] Each of the fifth compositions has a light transmittance as shown in the graph of Fig. 22. Here, each of the fifth compositions exhibited a high transmittance of 75% or more on average in the mid-infrared wavelength band of 3 to 5 μm. It was confirmed that the fifth composition additionally contains a dopant, and thus the transmittance, which is one of the optical properties of the composition, is relatively superior to a composition to which no dopant is added.

[0104] Furthermore, the glass produced using each of the fifth compositions also has excellent releasability and an anti-reflective coating is applied to the surface. When an anti-reflective coating is applied to the surface of the glass produced using each of the fifth compositions, it can be confirmed that the composition ensures a mid-infrared light transmittance (e.g., 94%) that is equal to or higher than the aforementioned transmittance.

[0105] FIG. 23 is a diagram showing the contents of components constituting a mid-infrared light transmitting glass composition according to a sixth embodiment of the present invention.

[0106] A composition for mid-infrared light transmitting glass according to a sixth embodiment of the present invention (hereinafter, abbreviated as "sixth composition") is prepared by including TeO2, ZnO, and La2O3 as main materials and Nb2O3 as a dopant. To prepare the sixth composition, TeO2, ZnO, La2O3, and Nb2O3 are included in the following ratio of 70:(20-x):10:x, respectively. 1)TeO2:70mol%, ZnO:15mol%, La2O3:10mol%, Nb2O3:5mol% 2)TeO2:70mol%, ZnO:10mol%, La2O3:10mol%, Nb2O3:10mol% 3)TeO2:70mol%, ZnO:5mol%, La2O3:10mol%, Nb2O3:15mol%

[0107] In producing each of the sixth compositions, the Nb2O3 content was varied, and the ZnO content was also varied in accordance with the change in the Nb2O3 content.

[0108] FIG. 24 is a diagram showing a mid-infrared light transmitting glass according to a sixth embodiment of the present invention.

[0109] (a) to (c) in Fig. 24 show glasses realized from each of the sixth compositions. With reference to (a) to (c) in Fig. 24, it was confirmed that no crystallization occurred in any of the sixth compositions when they were realized into glass.

[0110] FIG. 25 is a graph showing the transmittance by wavelength of a mid-infrared light transmitting glass composition according to the sixth embodiment of the present invention.

[0111] Each of the sixth compositions has a light transmittance as shown in the graph of FIG. 25. Here, each of the sixth compositions exhibited a high transmittance of 71% or more on average in the mid-infrared wavelength band of 2 to 5 μm. Therefore, each of the sixth compositions has properties suitable for realizing a mid-infrared light transmitting glass. That is, it was confirmed that even if Nb2O3 is contained as a dopant, the optical properties of the glass are not impaired. Furthermore, the glass realized with each of the sixth compositions also has excellent release properties and is anti-reflective coated on the surface. When an anti-reflective coating is applied to the surface of the glass realized with each of the sixth compositions, a mid-infrared light transmittance equal to or higher than the above-mentioned transmittance can be secured.

[0112] FIG. 26 is a graph showing the glass transition temperature, crystallization temperature, and thermal stability according to the composition of a mid-infrared light transmitting glass composition according to the sixth embodiment of the present invention.

[0113] Referring to the graph shown in FIG. 26, it can be seen that the sixth composition has excellent thermal stability of 170°C or more regardless of the content of Nb2O3. The lower the content of Nb2O3 in the sixth composition, the higher the thermal stability. It can be seen that the excellent thermal stability of the composition is achieved by including Nb2O3 as a dopant together with the main material.

[0114] FIG. 27 is a graph showing the glass transition temperature and the softening temperature according to the composition of the mid-infrared light transmitting glass composition according to the sixth embodiment of the present invention.

[0115] 27, it was confirmed that the sixth composition had a softening temperature lower than the reference value (550°C) regardless of the content of Nb2O3. The lower the content of Nb2O3 in the sixth composition, the lower the softening temperature of the composition.

[0116] FIG. 28 is a graph showing the thermal expansion coefficient depending on the composition of the mid-infrared light transmitting glass composition according to the sixth embodiment of the present invention.

[0117] The coefficient of thermal expansion (CTE) refers to the degree to which the volume of an object changes when the temperature of the object changes. A glass composition or glass having a high coefficient of thermal expansion means that the volume of the glass or an optical component molded from the glass can change to a significant level when exposed to an environment with frequent temperature changes. Since it is preferable for a glass composition or glass to be insensitive to temperature changes, it is preferable for the coefficient of thermal expansion of the glass composition or glass to be equal to or less than a certain reference value. Here, the reference value is 15(*10 -6 / K).

[0118] Referring to the graph shown in FIG. 28, no matter how much Nb2O3 is contained in the sixth composition, all of them are within the standard value (15*10 -6 / K), the higher the content of Nb2O3 in the sixth composition, the lower the thermal expansion coefficient of the composition.

[0119] FIG. 29 is a diagram showing the contents of components constituting a mid-infrared light transmitting glass composition according to a seventh embodiment of the present invention.

[0120] A mid-infrared light transmitting glass composition according to a seventh embodiment of the present invention (hereinafter, abbreviated as "seventh composition") is prepared by including TeO2, BaO, and ZnO as main materials and MoO3 as a dopant. To prepare the seventh composition, TeO2, BaO, ZnO, and MoO3 are included in the following ratio of 60:10:(30-x):x, respectively. 1)TeO2:60mol%, BaO:10mol%, ZnO:25mol%, MoO3:5mol% 2)TeO2:60mol%, BaO:10mol%, ZnO:22.5mol%, MoO3:7.5mol% 3)TeO2:60mol%, BaO:10mol%, ZnO:20mol%, MoO3:10mol%

[0121] In producing each of the seventh compositions, the content of MoO3 was varied, and the content of ZnO was also varied in accordance with the change in the content of MoO3.

[0122] FIG. 30 is a diagram showing a mid-infrared light transmitting glass according to a seventh embodiment of the present invention.

[0123] (a) to (c) in Fig. 30 show glasses realized from each of the seventh compositions. With reference to (a) to (c) in Fig. 30, it was confirmed that no crystallization occurred in any of the seventh compositions when they were realized into glass.

[0124] FIG. 31 is a diagram showing the contents of components constituting a mid-infrared transmitting glass composition according to an eighth embodiment of the present invention.

[0125] The composition for mid-infrared light transmitting glass according to the eighth embodiment of the present invention (hereinafter, abbreviated as "the eighth composition") is prepared by including TeO2, BaO, and ZnO as main materials and Nb2O3 as a dopant. To prepare the eighth composition, TeO2, BaO, ZnO, and Nb2O3 are included in the ratio of 60:10:(30-x):x, respectively, and are included in the following amounts. 1)TeO2:60mol%, BaO:10mol%, ZnO:25mol%, Nb2O3:5mol% 2)TeO2:60mol%, BaO:10mol%, ZnO:22.5mol%, Nb2O3:7.5mol% 3)TeO2:60mol%, BaO:10mol%, ZnO:20mol%, Nb2O3:10mol%

[0126] In producing each of the eighth compositions, the Nb2O3 content was varied, and the ZnO content was also varied in accordance with the change in the Nb2O3 content.

[0127] FIG. 32 is a diagram showing a mid-infrared light transmitting glass according to an eighth embodiment of the present invention.

[0128] (a) to (c) in Fig. 32 show glasses realized from each of the eighth compositions. With reference to (a) to (c) in Fig. 32, it was confirmed that no crystallization occurred in any of the eighth compositions when they were realized into glass.

[0129] FIG. 33 is a graph showing the glass transition temperature, crystallization temperature, and thermal stability according to the composition of the mid-infrared light transmitting glass composition according to the eighth embodiment of the present invention.

[0130] Referring to the graph shown in Fig. 33, it can be seen that the eighth composition has excellent thermal stability of 190°C or more regardless of the Nb2O3 content. The thermal stability increases as the Nb2O3 content in the eighth composition decreases or increases from 7.5mol% as a reference. It can be seen that the excellent thermal stability is achieved by including Nb2O3 as a dopant together with the main material.

[0131] FIG. 34 is a graph showing the glass transition temperature and the softening temperature according to the composition of the mid-infrared light transmitting glass composition according to the eighth embodiment of the present invention.

[0132] Referring to the graph shown in Figure 34, it can be seen that no matter how much Nb2O3 is contained in the eighth composition, all of them have a softening temperature significantly lower than the reference value (550°C). When the eighth composition contains only 7.5 mol% Nb2O3, it has the lowest softening temperature. It can be seen that the softening temperature is very low because the dopant Nb2O3 is contained together with the main material.

[0133] FIG. 35 is a graph showing the thermal expansion coefficient depending on the composition of the mid-infrared light transmitting glass composition according to the eighth embodiment of the present invention.

[0134] Referring to the graph in FIG. 35, no matter how much Nb2O3 is contained in the eighth composition, all of them are within the standard value (15*10 -6 / K), the higher the content of Nb2O3 in the eighth composition, the lower the thermal expansion coefficient of the composition.

[0135] FIG. 36 is a diagram showing the contents of components constituting a mid-infrared transmitting glass composition according to a ninth embodiment of the present invention.

[0136] A mid-infrared light transmitting glass composition according to a ninth embodiment of the present invention (hereinafter, abbreviated as "ninth composition") is prepared by including TeO2, BaO, and La2O3 as main materials and MoO3 as a dopant. To prepare the ninth composition, TeO2, BaO, La2O3, and MoO3 are included in the following ratio of 70:(20-x):10:x, respectively. 1)TeO2:70mol%, BaO:15mol%, La2O3:10mol%, MoO3:5mol% 2)TeO2:70mol%, BaO:10mol%, La2O3:10mol%, MoO3:10mol% 3)TeO2:70mol%, BaO:5mol%, La2O3:10mol%, MoO3:15mol%

[0137] In producing each of the ninth compositions, the content of MoO3 was varied, and the content of BaO was also varied in accordance with the change in the content of MoO3.

[0138] FIG. 37 is a diagram showing a mid-infrared light transmitting glass according to a ninth embodiment of the present invention.

[0139] (a) to (c) in Fig. 37 show glasses realized from each of the ninth compositions. With reference to (a) to (c) in Fig. 37, it was confirmed that no crystallization occurred in any of the ninth compositions when they were realized into glass.

[0140] FIG. 38 is a diagram showing the contents of components constituting a mid-infrared transmitting glass composition according to a tenth embodiment of the present invention.

[0141] A mid-infrared light transmitting glass composition according to a tenth embodiment of the present invention (hereinafter, abbreviated as "tenth composition") is manufactured by including TeO2, BaO, and La2O3 as main materials and Nb2O3 as a dopant. To manufacture the tenth composition, TeO2, BaO, La2O3, and Nb2O3 are included in the following amounts in the ratio of 70:(20-x):10:x, respectively. 1)TeO2:70mol%, BaO:15mol%, La2O3:10mol%, Nb2O3:5mol% 2)TeO2:70mol%, BaO:10mol%, La2O3:10mol%, Nb2O3:10mol% 3)TeO2:70mol%, BaO:5mol%, La2O3:10mol%, Nb2O3:15mol%

[0142] In producing each of the tenth compositions, the Nb2O3 content was varied, and the BaO content was also varied in accordance with the change in the Nb2O3 content.

[0143] FIG. 39 is a diagram showing a mid-infrared light transmitting glass according to a tenth embodiment of the present invention.

[0144] Figure 39 (a) to (c) show the glasses realized from each of the tenth compositions. With reference to Figure 39 (a) to (c), it was confirmed that no crystallization occurred in any of the tenth compositions when they were realized into glass.

[0145] FIG. 40 is a graph showing the glass transition temperature, crystallization temperature, and thermal stability depending on the composition of the mid-infrared light transmitting glass composition according to the tenth embodiment of the present invention.

[0146] Referring to the graph shown in Fig. 40, it can be seen that the tenth composition has excellent thermal stability of 130°C or more regardless of the Nb2O3 content. As the Nb2O3 content in the tenth composition increases, the thermal stability tends to become higher. In particular, when the Nb2O3 content is 10 mol%, it can be seen that the composition has very excellent thermal stability of 200°C or more.

[0147] FIG. 41 is a graph showing the glass transition temperature and softening temperature depending on the composition of the mid-infrared light transmitting glass composition according to the tenth embodiment of the present invention.

[0148] 41, it was confirmed that, regardless of the amount of Nb2O3 contained in the tenth composition, all of them had a softening temperature lower than the reference value (550°C). The lower the amount of Nb2O3 contained in the tenth composition, the lower the softening temperature of the composition.

[0149] FIG. 42 is a graph showing the thermal expansion coefficient depending on the composition of the mid-infrared light transmitting glass composition according to the tenth embodiment of the present invention.

[0150] Referring to the graph shown in FIG. 42, when the 10th composition contains 7.5 mol% or more of Nb2O3, the reference value (15*10 -6 / K), the higher the content of Nb2O3 in the tenth composition, the lower the thermal expansion coefficient of the composition.

[0151] FIG. 43 is a diagram showing the contents of components constituting a mid-infrared transmitting glass composition according to an eleventh embodiment of the present invention.

[0152] The mid-infrared light transmitting glass composition according to the eleventh embodiment of the present invention (hereinafter, abbreviated as "eleventh composition") is prepared by including TeO2, ZnO, and La2O3 as main materials and ZnF2 as a dopant. To prepare the eleventh composition, TeO2, ZnO, La2O3, and ZnF2 are included in the ratio of 70:(20-x):10:x, respectively, and are included in the following amounts. 1)TeO2:70mol%, ZnO:18.5mol%, La2O3:10mol%, ZnF2:1.5mol% 2)TeO2:70mol%, ZnO:17.5mol%, La2O3:10mol%, ZnF2:2.5mol% 3)TeO2:70mol%, ZnO:16.5mol%, La2O3:10mol%, ZnF2:3.5mol% 4)TeO2:70mol%, ZnO:15mol%, La2O3:10mol%, ZnF2:5.0mol%

[0153] In producing each of the eleventh compositions, the ZnF2 content was varied, and the ZnO content was also varied in accordance with the change in the ZnF2 content. However, when the ZnF2 content exceeded 5.0 mol%, crystallization occurred during the glass production process.

[0154] FIG. 44 is a graph showing the transmittance by wavelength of a mid-infrared light transmitting glass composition according to the eleventh embodiment of the present invention.

[0155] Each of the eleventh compositions has a light transmittance as shown in the graph of FIG. 44. Here, each of the eleventh compositions exhibited an average transmittance of 69% or more in the mid-infrared wavelength band of 3 to 5 μm. Therefore, it was confirmed that the optical properties of the glass produced are not impaired even if ZnF2 is contained as a dopant. Furthermore, the glass produced with each of the eleventh compositions has excellent release properties and is anti-reflective coated on the surface. When the surface of the glass produced with each of the eleventh compositions is anti-reflective coated, the composition can ensure a mid-infrared light transmittance equal to or higher than the transmittance described above.

[0156] FIG. 45 is a graph showing the glass transition temperature, crystallization temperature, and thermal stability according to the composition of the mid-infrared light transmitting glass composition according to the eleventh embodiment of the present invention.

[0157] 45, it can be seen that composition 11 has excellent thermal stability of 150° C. or more regardless of the ZnF2 content. As the ZnF2 content in composition 11 increases, the thermal stability tends to decrease.

[0158] FIG. 46 is a graph showing the refractive index depending on the composition of the mid-infrared light transmitting glass composition according to the eleventh embodiment of the present invention.

[0159] Referring to the graph shown in FIG. 46, the composition containing ZnF2 as a dopant (TZL-ZF(A)) exhibited optical properties (reduced Abbe number) with a lower refractive index and an increased dispersion value compared to the composition (TZL) containing TeO2, ZnO and La2O3 as main materials without the addition of a dopant. Regardless of the presence or absence of the dopant, all compositions have excellent optical properties with a refractive index of 1.9 or more in the mid-infrared wavelength band (3 to 5 μm). Therefore, the eleventh composition can be designed into a lens having a thin thickness and can be fabricated into an optical system with a thin structure. In addition, the depth (shape) of the lens surface can be designed to be small, and the fabrication yield can be improved when the eleventh composition is fabricated into a lens.

[0160] FIG. 47 is a diagram showing the contents of components constituting a mid-infrared transmitting glass composition according to a twelfth embodiment of the present invention.

[0161] A composition for mid-infrared light transmitting glass according to a twelfth embodiment of the present invention (hereinafter, abbreviated as "composition no. 12") is also prepared by including TeO2, ZnO, and La2O3 as main materials and ZnF2 as a dopant, like composition no. 11. However, unlike composition no. 11, for preparing composition no. 12, TeO2, ZnO, La2O3, and ZnF2 are included in the ratio of (70-x):20:10:x, respectively, and are included in the following amounts, respectively. 1)TeO2:68.5mol%, ZnO:20mol%, La2O3:10mol%, ZnF2:1.5mol% 2)TeO2:67.5mol%, ZnO:20mol%, La2O3:10mol%, ZnF2:2.5mol% 3)TeO2:66.5mol%, ZnO:20mol%, La2O3:10mol%, ZnF2:3.5mol% 4)TeO2:65mol%, ZnO:20mol%, La2O3:10mol%, ZnF2:5.0mol%

[0162] In producing each of the twelfth compositions, the ZnF2 content was varied, and the TeO2 content was also varied in accordance with the change in the ZnF2 content. However, when the ZnF2 content exceeds 5.0 mol%, crystallization occurs during the glass production process.

[0163] FIG. 48 is a graph showing the transmittance by wavelength of a mid-infrared light transmitting glass composition according to the twelfth embodiment of the present invention.

[0164] Each of the twelfth compositions has a light transmittance as shown in the graph in Figure 48. Here, each of the twelfth compositions exhibits an average transmittance of 70% or more in the mid-infrared wavelength band of 3 to 5 μm. Therefore, it was confirmed that even if the combination of the main components contains ZnF2 as a dopant, the optical properties of the glass produced are not impaired.

[0165] Furthermore, the glass produced from each of the twelfth compositions has excellent releasability and has an anti-reflective coating on the surface. When the glass produced from each of the twelfth compositions has an anti-reflective coating on the surface, it has been confirmed that the glass has a mid-infrared transmittance (e.g., 86% or more) equal to or higher than the above-mentioned transmittance.

[0166] FIG. 49 is a graph showing the glass transition temperature, crystallization temperature, and thermal stability according to the composition of the mid-infrared light transmitting glass composition according to the twelfth embodiment of the present invention.

[0167] 49, it can be seen that composition 12 has thermal stability of 100°C or more regardless of the ZnF2 content. As the ZnF2 content in composition 12 increases, the thermal stability of the composition decreases.

[0168] FIG. 50 is a graph showing the refractive index depending on the composition of the mid-infrared light transmitting glass composition according to the twelfth embodiment of the present invention.

[0169] Referring to the graph shown in FIG. 50, the composition containing ZnF2 as a dopant (TZL-ZF(B)) exhibited optical properties (a decrease in Abbe number) in which the refractive index was decreased and the dispersion value was increased compared to the composition (TZL) containing TeO2, ZnO, and La2O3 as main materials without the addition of a dopant. In particular, the composition containing only 5 mol% of ZnF2 exhibited optical properties (an increase in Abbe number) in which the refractive index was relatively increased and the dispersion value was decreased compared to the other compositions. Regardless of the presence or absence of the addition of a dopant, all compositions have excellent optical properties with a refractive index of 1.9 or more in the mid-infrared wavelength band (3 to 5 μm). Therefore, the twelfth composition can have the same merits as the eleventh composition.

[0170] In addition, the smaller the dispersion value, the smaller the deviation of the focal length according to the wavelength of the optical configuration, which is advantageous in correcting chromatic aberration. Since the optical configuration is advantageous in correcting chromatic aberration, it can have excellent image resolution. Therefore, an optical configuration made of a composition having a characteristic of relatively reduced dispersion value can ensure excellent image resolution.

[0171] FIG. 51 is a graph showing hardness depending on the composition of the mid-infrared light transmitting glass composition according to the twelfth embodiment of the present invention.

[0172] 51, the glass realized with composition 11 showed a tendency for the hardness to increase as the ZnF2 content decreased, while the glass realized with composition 12 showed a tendency for the hardness to increase as the ZnF2 content increased. It was confirmed that when the ZnF2 content was 1.5 mol%, the glass realized with composition 11 had the hardest hardness, and regardless of the content, the glass realized with composition 11 had a hardness of 355 KgF / mm 2 On the other hand, when the ZnF2 content was 5.0 mol%, the glass realized with the 12th composition had the highest hardness, and the glass realized with the 12th composition had a hardness of 355 KgF / mm 2 It was confirmed that the hardness was equal to or higher than that of the conventional hardness test pieces.

[0173] In addition, it was confirmed that glasses made of compositions containing ZnF2 as a dopant all have a hardness above a certain level on average, compared to glasses made of compositions not containing ZnF2 as a dopant.

[0174] FIG. 52 is a diagram showing the contents of components constituting a mid-infrared light transmitting glass composition according to a thirteenth embodiment of the present invention.

[0175] A mid-infrared light transmitting glass composition according to a thirteenth embodiment of the present invention (hereinafter, abbreviated as "thirteenth composition") is prepared by including TeO2, ZnO, and La2O3 as main materials and MoO3 as a dopant. To prepare the thirteenth composition, TeO2, ZnO, La2O3, and MoO3 are included in the following ratio of 60:30:(10-x):x, respectively. 1)TeO2:60mol%, ZnO:30mol%, La2O3:8.0mol%, MoO3:2.0mol% 2)TeO2:60mol%, ZnO:30mol%, La2O3:7.0mol%, MoO3:3.0mol% 3)TeO2:60mol%, ZnO:30mol%, La2O3:6.0mol%, MoO3:4.0mol% 4)TeO2:60mol%, ZnO:30mol%, La2O3:5.0mol%, MoO3:5.0mol%

[0176] In producing each of the thirteenth compositions, the MoO3 content was varied, and the La2O3 content was also varied in accordance with the change in the MoO3 content.

[0177] FIG. 53 is a graph showing the transmittance by wavelength of a mid-infrared light transmitting glass composition according to the thirteenth embodiment of the present invention.

[0178] Each of the 13th compositions has a light transmittance as shown in the graph of FIG. 53. Here, each of the 13th compositions exhibits an average transmittance of 70% or more in the mid-infrared wavelength band of 3 to 5 μm. In particular, a composition containing only 2.0 mol % or 3.0 mol % of MoO3 exhibits an excellent mid-infrared light transmittance of 76% or more. Therefore, each of the 13th compositions has properties suitable for realizing a mid-infrared light transmitting glass.

[0179] Furthermore, the glass produced using each of the thirteenth compositions has excellent releasability and can be anti-reflective coated on its surface. When the glass produced using each of the thirteenth compositions has an anti-reflective coating on its surface, it can be confirmed that the glass has a mid-infrared transmittance (e.g., 94% or more) equal to or higher than the above-mentioned transmittance.

[0180] FIG. 54 is a graph showing the glass transition temperature, crystallization temperature, and thermal stability according to the composition of a mid-infrared light transmitting glass composition according to the thirteenth embodiment of the present invention.

[0181] Referring to the graph in Figure 54, it can be seen that composition 13 has excellent thermal stability of 175°C or more regardless of the MoO3 content. As the MoO3 content in composition 13 increases, the thermal stability tends to increase. It can be seen that the thermal stability of the composition is excellent due to the inclusion of MoO3 as a dopant.

[0182] In other words, it was confirmed that the inclusion of MoO3 as a dopant not only does not impair the optical properties of the composition, but also that the optical properties of the composition are superior to those of a composition not containing the dopant.

[0183] FIG. 55 is a graph showing the refractive index depending on the composition of a mid-infrared light transmitting glass composition according to the thirteenth embodiment of the present invention.

[0184] Referring to the graph shown in FIG. 55, the composition containing MoO3 as a dopant (TZL-Mo(A)) exhibited optical properties (reduced Abbe number) with a lower refractive index and an increased dispersion value than the composition (TZL) containing TeO2, ZnO, and La2O3 as main materials without the addition of a dopant. Moreover, regardless of the presence or absence of the addition of a dopant, all compositions have excellent optical properties with a refractive index of 1.9 or more in the mid-infrared wavelength band (3 to 5 μm). Therefore, the thirteenth composition can have the same merits as the twelfth and eleventh compositions.

[0185] FIG. 56 is a diagram showing the contents of components constituting a mid-infrared light transmitting glass composition according to a fourteenth embodiment of the present invention.

[0186] A mid-infrared light transmitting glass composition according to a fourteenth embodiment of the present invention (hereinafter, abbreviated as "fourteenth composition") is prepared by including TeO2, ZnO, and La2O3 as main materials and MoO3 as a dopant. However, unlike the thirteenth composition, in order to prepare the fourteenth composition, TeO2, ZnO, La2O3, and MoO3 are included in the following amounts in the ratio of 70:20:(10-x):x. 1)TeO2:70mol%, ZnO:20mol%, La2O3:8.0mol%, MoO3:2.0mol% 2)TeO2:70mol%, ZnO:20mol%, La2O3:7.0mol%, MoO3:3.0mol% 3)TeO2:70mol%, ZnO:20mol%, La2O3:6.0mol%, MoO3:4.0mol% 4)TeO2:70mol%, ZnO:20mol%, La2O3:5.0mol%, MoO3:5.0mol%

[0187] In producing each of the thirteenth compositions, the MoO3 content was varied, and the La2O3 content was also varied in accordance with the change in the MoO3 content.

[0188] FIG. 57 is a graph showing the transmittance by wavelength of a mid-infrared light transmitting glass composition according to the fourteenth embodiment of the present invention.

[0189] Each of the 14th compositions has a light transmittance as shown in the graph of FIG. 57. Here, each of the 14th compositions exhibited an average transmittance of 65% or more at wavelengths of 3 to 5 μm, which is the mid-infrared wavelength band. In particular, the remaining compositions, except for the composition containing only 5.0 mol% MoO3, exhibited excellent mid-infrared light transmittance of 69% or more on average. Therefore, it was confirmed that the optical properties of the glass produced are not impaired even if the combination of the main components contains MoO3 as a dopant. Furthermore, the glass produced from each of the 14th compositions has excellent release properties and can be anti-reflectively coated on the surface. When an anti-reflective coating is applied to the surface of the glass produced from each of the 14th compositions, a mid-infrared light transmittance equal to or higher than the above-mentioned transmittance can be secured.

[0190] FIG. 58 is a graph showing the glass transition temperature, crystallization temperature, and thermal stability depending on the composition of the mid-infrared light transmitting glass composition according to the fourteenth embodiment of the present invention.

[0191] Referring to the graph in Figure 58, it can be seen that composition 14 has excellent thermal stability of about 130°C or more regardless of the MoO3 content. As the MoO3 content in composition 13 increases, the thermal stability tends to decrease, and the composition containing 3.0 mol% MoO3 showed the best thermal stability. It can be seen that the excellent thermal stability is due to the inclusion of MoO3 as a dopant.

[0192] FIG. 59 is a graph showing hardness depending on the composition of the mid-infrared light transmitting glass composition according to the fourteenth embodiment of the present invention.

[0193] Referring to Figure 59, the glass realized with composition 13 showed a tendency for the hardness to increase as the MoO3 content decreased or increased from 4.0mol%, while the glass realized with composition 14 showed a tendency for the hardness to increase as the MoO3 content decreased. It can be seen that when the MoO3 content was 5.0mol%, the glass realized with composition 13 had the hardest hardness, with a hardness of 330KgF / mm, regardless of the content. 2 On the other hand, when the content of MoO3 was 2.0 mol%, the glass realized with the 14th composition had the hardest hardness, and the glass realized with the 14th composition had a hardness of 340 KgF / mm3 regardless of the content. 2 It was confirmed that the hardness was equal to or higher than that of the conventional hardness test pieces.

[0194] In Fig. 1, each process is described as being performed sequentially, but this is merely an example of the technical idea of ​​an embodiment of the present invention, and Fig. 1 is not limited to a chronological order because a person skilled in the art to which the embodiment of the present invention pertains can change the order described in each drawing and perform the process or perform one or more processes in parallel in various modifications and alterations without departing from the essential characteristics of the embodiment of the present invention.

[0195] Meanwhile, the process shown in Fig. 1 can be embodied as computer readable code in a computer readable recording medium. The computer readable recording medium includes all kinds of recording devices in which data read by a computer system is stored. That is, the computer readable recording medium includes storage media such as magnetic storage media (e.g., ROM, floppy disk, hard disk, etc.) and optically readable media (e.g., CD-ROM, DVD, etc.). Also, the computer readable recording medium can be distributed among computer systems connected via a network so that the computer readable code can be stored and executed in a distributed manner.

[0196] The above description is merely an illustrative example of the technical idea of ​​the present embodiment, and various modifications and variations may be made by a person having ordinary knowledge in the technical field to which the present embodiment belongs, without departing from the essential characteristics of the present embodiment. Therefore, the present embodiment is intended to explain, not to limit, the technical idea of ​​the present embodiment, and the scope of the technical idea of ​​the present embodiment is not limited by such an embodiment. The scope of protection of the present embodiment should be interpreted according to the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present embodiment.

[0197] CROSS-REFERENCE TO RELATED APPLICATIONS This patent application claims priority under 35 U.S.C. § 119(a) to patent application serial number 10-2020-0050852, filed in Korea on April 27, 2020, the entire contents of which are incorporated herein by reference. At the same time, this patent application claims priority to countries other than the United States for the same reasons as above, the entire contents of which are incorporated herein by reference. [Aspect 1] A glass composition that transmits light in the mid-infrared wavelength band at a predetermined standard value or more, TeO 2 , La 2 O 3 and ZnO in respective predetermined contents. [Aspect 2] The glass composition comprises: TeO 2 55-80 mol% of La 2 O 3 2. The composition for glass according to claim 1, comprising 5 to 10 mol % of ZnO and 10 to 40 mol % of ZnO. [Aspect 3] A glass composition that transmits light in the mid-infrared wavelength band at a predetermined standard value or more, TeO 2 , La 2 O 3 and BaO in respective predetermined contents. [Aspect 4] The glass composition comprises: TeO 2 Only 70-80 mol% of La 2 O 3 4. The glass composition according to claim 3, comprising 10 mol % of and 10 to 20 mol % of BaO. [Aspect 5] A glass composition that transmits light in the mid-infrared wavelength band at a predetermined standard value or more, TeO 2 , ZnO, La 2 O 3 and a dopant for varying the optical properties of the glass, each of which is contained in a predetermined amount. [Aspect 6] The dopant is Nb 2 O 3 , MoO 3 or ZnF 2 6. The composition for glass according to claim 5, wherein [Aspect 7] The glass composition comprises: TeO 2 65-70mol%, ZnO 5-20mol%, La 2 O 3 6. The composition for glass according to aspect 5, comprising 10 mol % of the above-mentioned component (I) and 5 to 15 mol % of the above-mentioned dopant. [Aspect 8] A glass composition that transmits light in the mid-infrared wavelength band at a predetermined standard value or more, TeO 2 A glass composition comprising BaO, ZnO and a dopant for varying the optical properties of the glass, each in a predetermined content. [Aspect 9] The dopant is Nb 2 O 3 or MoO 3 9. The composition for glass according to claim 8, wherein [Aspect 10] The glass composition comprises: TeO 2 9. The glass composition according to claim 8, comprising 60 mol % of BaO, 10 mol % of ZnO, and 5 to 10 mol % of the dopant. [Aspect 11] A glass composition that transmits light in the mid-infrared wavelength band at a predetermined standard value or more, TeO 2 , BaO, La 2 O 3 and a dopant for varying the optical properties of the glass, each of which is contained in a predetermined amount. [Aspect 12] The dopant is Nb 2 O 3 or MoO 3 12. The composition for glass according to claim 11, wherein [Aspect 13] The glass composition comprises: TeO 2 70 mol%, BaO 5 to 15 mol%, La 2 O 3 12. The composition for glass according to claim 11, comprising 10 mol % of the above-mentioned component (I) and 5 to 15 mol % of the above-mentioned dopant. [Aspect 14] A method for producing a glass composition that transmits light in the mid-infrared wavelength band at a predetermined standard value or more, comprising the steps of: TeO 2 A mixing process in which the specified raw materials, including a melting step of melting the material mixed in the mixing step at a first predetermined temperature for a first predetermined time; an annealing step of annealing the material melted in the melting step into a mold in a first predetermined environment; A method for producing a composition for glass, comprising: [Aspect 15] The method for producing a glass composition according to aspect 14, further comprising an exposure step of placing the materials mixed in the mixing step in a predetermined container and exposing them to a second predetermined environment for a second predetermined time. [Aspect 16] The predetermined raw materials are: La 2 O 3 15. The method for producing a composition for glass according to claim 14, wherein the composition contains any two of BaO and ZnO.

Claims

[Claim 1] A glass composition that transmits light in the mid-infrared wavelength band in the range of 3 μm to 5 μm, TeO ２ 60 mol % of BaO, 10 mol % of ZnO, and 5 to 10 mol % of a dopant for changing the optical properties of the glass; The dopant is Nb 2 O 3 or MoO 3 ; Glass compositions.

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