High-refractive-index infrared glass as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of infrared glass, and particularly relates to high-refractive-index infrared glass as well as a preparation method and application thereof, and the infrared glass comprises the following components in percentage by mole: 16-28% of Ge, 58-64% of Te, 7-14% of Se, 2-10% of As and 0-2% of Sb. The preparation method comprises the three steps of raw material deoxidization, raw material mixing and heating smelting. By optimizing the components and the proportion of the glass and further performing secondary deoxidization on the raw materials, the refractive index of the infrared glass is improved, and the absorption peak of the infrared glass in a far infrared region is reduced, so that the infrared glass can be applied to infrared thermal imaging equipment, and the sensitivity of the equipment is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of infrared glass, and in particular relates to high-refractive-index infrared glass. Background Art

[0002] At present, there are three main systems of chalcogenide glass that are widely used at home and abroad, namely As-Se, Ge-As-Se, and Ge-Sb-Se. Among them, As40Se60 far-infrared glass has the highest refractive index, with a refractive index of 2.7 at a wavelength of 10.6μm. It is the chalcogenide glass with the highest demand in the current market and is favored by many optical designers.

[0003] However, with the continuous expansion of the infrared market, many designers have put forward higher technical requirements for chalcogenide glass. They need a new material with good glass transition temperature, high refractive index, and can meet the requirements of coating temperature and precision molding process. For example, with the popularity and demand of infrared thermal imaging technology, if the traditional infrared glass requires 3 lenses to achieve the lens, the high refractive index infrared glass only needs 2 lenses to achieve the same performance, so the demand for high refractive index infrared glass is increasing.

[0004] In the prior art, for example, Chinese patent publication number CN104402220A discloses a chalcogenide optical glass, whose system is Ga-Ge-S-Te, does not contain harmful substances such as arsenic, selenium, antimony, and has a refractive index of 2.7 to 3.6 at 10 μm. Another example is Chinese patent publication number CN105541111A discloses a far-infrared high nonlinear Ge-Te-Se chalcogenide glass, whose composition formula is Ge20TexSe(80-x), wherein x=1-70, x is a molar fraction, and the chalcogenide glass does not contain the toxic As element added to the traditional chalcogenide glass, and introduces the green and environmentally friendly Te element into the Ge-Se chalcogenide glass, and optimizes the Ge-Se chalcogenide glass by utilizing the high polarizability of the Te element, and the obtained Ge-Te-Se chalcogenide glass has good transmittance, glass-forming ability and ultra-high nonlinear refractive index, and the chalcogenide glass has a wide range of applications in the far-infrared region.

[0005] However, the infrared glass prepared by the above-mentioned prior art has obvious absorption peaks at 12 to 14 μm, which will reduce the sensitivity of infrared thermal imaging equipment and limit the scope and field of its application. Summary of the invention

[0006] In view of the problem that the existing infrared glass mentioned in the background technology has an obvious absorption peak in the far infrared, which will reduce the sensitivity of the equipment when it is used in infrared thermal imaging equipment, the present invention improves the refractive index of the infrared glass and reduces its absorption peak in the far infrared region by optimizing the glass components and their ratios and processing the raw materials.

[0007] The specific techniques of the present invention are as follows:

[0008] A high refractive index infrared glass comprises the following components in mole percentage: 16-28% Ge, 58-64% Te, 7-14% Se, 2-10% As and 0-2% Sb.

[0009] Furthermore, the refractive index of the infrared glass at 10 μm is 2.9 to 3.4.

[0010] Furthermore, the infrared glass comprises the following components in molar percentage: 23-25% Ge, 61-63% Te, 9-11% Se, 3-6% As and 0-0.2% Sb; the refractive index of the infrared glass at 10 μm is 3.1-3.3.

[0011] Furthermore, the infrared transmittance of the infrared glass in the 4-16 μm band is 56-59%, and the infrared transmittance in the 8-14 μm band is 57-63%.

[0012] Furthermore, the softening temperature of the infrared glass is 150-240°C.

[0013] The present invention also provides a method for preparing high refractive index infrared glass, comprising the following steps:

[0014] Step 1: Deoxygenation of raw materials: Deoxygenate the raw materials selenium, tellurium and arsenic in the purification tube and transfer them to an operating table protected by inert gas;

[0015] Step 2, mixing raw materials: weighing and mixing the components according to the component ratio on an operating table protected by inert gas to obtain a mixture, then putting the mixture into a sealed bottle, and sealing the vacuum port in the sealed bottle;

[0016] Step 3, heating and melting: transfer the sealed bottle to a melting furnace for heating and melting. Keep the sealing sheet shaking during the melting process. After the melting is completed, take out the sealed bottle for annealing. After the annealing is completed, an infrared glass ingot is obtained.

[0017] Furthermore, the deoxygenation of selenium and tellurium in step 1 includes the following steps: placing selenium and tellurium in a quartz purification tube respectively and continuously introducing high-purity hydrogen, heating the selenium and tellurium to a molten state after the air in the tube is completely removed, stopping heating after complete reaction and continuously introducing high-purity hydrogen, stopping ventilation after the temperature drops to room temperature, taking out the selenium and tellurium from the purification tube and quickly transferring them to an operating platform protected by inert gas.

[0018] Furthermore, the deoxygenation of arsenic in step one includes the following steps: placing arsenic in a quartz purification tube, evacuating it to below 10 Pa and then heating it to 300 degrees, keeping the temperature at this temperature to react and remove oxygen in the arsenic, cooling it to room temperature after the reaction is completed, filling it with high-purity nitrogen to normal pressure, and then quickly taking out the arsenic and transferring it to an operating platform protected by inert gas.

[0019] Furthermore, in the step three, the smelting temperature is 850-1100° C., and the smelting time is 16-20 h; the annealing temperature is 160-200° C., and the annealing rate is -10--1° C. / h.

[0020] The invention also provides an application of high-refractive-index infrared glass in infrared thermal imaging equipment.

[0021] Compared with the prior art, the present invention has the following effective effects:

[0022] 1. The infrared glass prepared by the present invention has a higher refractive index than traditional infrared glass by optimizing the glass components and their ratios, and the refractive index at 10 μm is above 2.9, and can reach up to 3.4. At the same time, compared with other high-refractive infrared glasses, the present invention reduces the oxygen content in the raw materials by deoxygenating the raw materials of selenium, tellurium and arsenic, so that the infrared glass prepared by the present invention expands the passing range in the long-wave direction and reduces its absorption peak in the 12-14 μm band, which will not cause the transmittance of the 8-14 μm band used by the infrared thermal imaging equipment to decrease, thereby affecting its sensitivity.

[0023] 2. The present invention reduces the crystallization tendency of glass by adding a small amount of arsenic and a trace amount of antimony into the glass, thereby reducing the difficulty of glass production, expanding the secondary molding softening temperature range of the glass, and improving the molding performance of the glass. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a Fourier infrared spectrum of a high refractive index infrared glass in Example 1 of the present invention;

[0025] Figure 2 is a Fourier infrared spectrum of a high refractive index infrared glass in Example 2 of the present invention;

[0026] Figure 3 is a Fourier infrared spectrum of a high refractive index infrared glass in Example 3 of the present invention;

[0027] Figure 4 This is a Fourier infrared spectrum of a high refractive index infrared glass in Comparative Example 1 of the present invention;

[0028] Figure 5 This is a Fourier infrared spectrum of a high refractive index infrared glass in Comparative Example 6 of the present invention. DETAILED DESCRIPTION

[0029] The specific implementation of the present invention is further explained below through the drawings and examples.

[0030] Example 1

[0031] The present embodiment provides a high refractive index infrared glass, which comprises the following components in mole percentage: 24% Ge, 61.5% Te, 10% Se, 4% As and 0.5% Sb.

[0032] This embodiment also provides a method for preparing high refractive index infrared glass, comprising the following steps:

[0033] Step 1: Deoxygenation of raw materials: Deoxygenate the raw materials selenium, tellurium and arsenic in the purification tube and transfer them to an operating table protected by inert gas;

[0034] Specifically, selenium and tellurium are placed in quartz purification tubes respectively and high-purity hydrogen is continuously introduced. After the air in the tube is completely removed, selenium and tellurium are heated to a molten state. After the reaction is complete, heating is stopped and high-purity hydrogen is continuously introduced. After the temperature drops to room temperature, ventilation is stopped. Selenium and tellurium are taken out of the purification tubes and quickly transferred to a glove box protected by inert gas.

[0035] Arsenic is placed in a quartz purification tube, evacuated to below 10 Pa, and then heated to 300 degrees. At this temperature, the reaction is kept to remove oxygen from the arsenic. After the reaction is completed, the temperature is cooled to room temperature and filled with high-purity nitrogen to normal pressure. Then the arsenic is quickly taken out and transferred to an operating platform protected by inert gas. Germanium and antimony are relatively stable and do not need to be deoxygenated separately.

[0036] Step 2, mixing raw materials: weighing and mixing the components according to the component ratio on an operating table protected by inert gas to obtain a mixture, then putting the mixture into a sealed bottle, and sealing the vacuum port in the sealed bottle;

[0037] Specifically, in an inert gas-protected glove box, each component of the infrared glass is weighed in proportion and mixed to obtain a mixture, and then the mixture is placed in a quartz ampoule. The quartz ampoule containing the mixture is then taken out of the glove box, quickly connected to a vacuum pump, and evacuated to below 10-5Pa, and the evacuation is continued for a period of time so that the gas adsorbed on the surface of the raw material can completely overflow and be evacuated, and then the quartz bottle is sealed with a hydrogen-oxygen welding gun, and the evacuation is continued during the sealing process until completion.

[0038] Step 3, heating and melting: transfer the sealed bottle to a melting furnace for heating and melting. Keep the sealing sheet shaking during the melting process. After the melting is completed, take out the sealed bottle for annealing. After the annealing is completed, an infrared glass ingot is obtained.

[0039] Specifically, the sealed quartz ampoule is transferred to a melting furnace and heated for melting. During the heating process, the furnace is continuously swung so that the glass liquid formed after the mixture in the bottle is melted can be shaken evenly. After the melting time is up, the quartz ampoule is taken out of the melting furnace and placed in an annealing furnace for annealing according to the process. After the annealing is completed, the quartz ampoule is taken out, and the quartz ampoule is gently broken to take out the solidified glass liquid to obtain an infrared glass ingot. The melting temperature is 1000°C, the melting time is 18h, the annealing temperature is 180°C, and the annealing rate is -5°C / h. The Fourier infrared spectrum of the infrared glass formed is shown in the attached figure. Figure 1 shown.

[0040] The present invention also provides an application of high refractive index infrared glass in infrared thermal imaging equipment. The high refractive index infrared glass is prepared according to the above-mentioned component proportion and preparation method.

[0041] Example 2

[0042] The difference between this embodiment and embodiment 1 is that the molar composition of the infrared glass is different. Specifically, the infrared glass comprises the following components in terms of molar percentage: 24% Ge, 60% Te, 10% Se, 4% As and 2% Sb. The Fourier infrared spectrum of the infrared glass formed is shown in the attached figure. Figure 2 shown.

[0043] Example 3

[0044] The difference between this embodiment and embodiment 1 is that the molar composition of the infrared glass is different. Specifically, the infrared glass comprises the following components by molar percentage: 18.2% Ge, 62.5% Te, 6% Se, 12.5% ​​As and 0.5% Sb. The Fourier infrared spectrum of the infrared glass formed is shown in the attached figure. Figure 3 shown.

[0045] Comparative Example 1

[0046] The difference between this comparative example and Example 1 is that the molar composition of the infrared glass is different. Specifically, the infrared glass comprises the following components by molar percentage: 11% Ge, 61% Te, 5.5% Se, 22% As and 0.5% Sb. The Fourier infrared spectrum of the infrared glass formed is shown in the attached figure. Figure 4 shown.

[0047] Comparative Example 2

[0048] The difference between this comparative example and Example 1 is that the molar composition of the infrared glass is different. Specifically, the infrared glass includes the following components in molar percentage: 28% Ge, 61.5% Te, 6% Se, 4% As and 0.5% Sb.

[0049] Comparative Example 3

[0050] The difference between this comparative example and Example 1 is that the molar composition of the infrared glass is different. Specifically, the infrared glass includes the following components in molar percentage: 23.5% Ge, 63% Te, 6.5% Se, 6.5% As and 0.5% Sb.

[0051] Comparative Example 4

[0052] The difference between this comparative example and Example 1 is that the molar composition of the infrared glass is different. Specifically, the infrared glass includes the following components in molar percentage: 20% Ge, 60% Te, 20% Se, 0% As and 0.5% Sb.

[0053] Comparative Example 5

[0054] The difference between this comparative example and Example 1 is that the molar composition of the infrared glass is different. Specifically, the infrared glass includes the following components in molar percentage: 28% Ge, 59% Te, 6% Se, 4% As and 3% Sb.

[0055] Comparative Example 6

[0056] The difference between this comparative example and Example 1 is that the preparation method is different. Specifically, step 1 in the preparation method is omitted. The Fourier infrared spectrum of the infrared glass formed is shown in the attached figure. Figure 5 shown.

[0057] The infrared glass properties of the above embodiments and comparative examples were tested, and the test results are shown in Table 1 below:

[0058] Table 1: Performance test table of embodiments and comparative examples

[0059]

[0060]

[0061] Analysis of experimental results: From the above test results, it can be seen that the infrared glass prepared by the raw material composition ratio of the present invention does not have crystallization phenomenon and can form a glass phase. And the test shows that its refractive index can reach about 3.1, which is significantly improved compared with the general infrared glass refractive index. At the same time, its softening temperature can reach above 200°C, which is convenient for further processing and production of infrared glass. Its transmittance in the far infrared region of 8-14μm can reach 56-59%, and the absorption peak between 12-14μm is very small.

[0062] Comparative Examples 1 to 5 changed the raw material composition ratio. Although the infrared glass formed in Comparative Example 1 can form a glass phase, its softening temperature is about 100° C. and has no practical value. The infrared glass formed in Comparative Examples 2 to 5 has crystallization phenomenon and cannot be used.

[0063] In the preparation process of Comparative Example 6, the raw materials were not subjected to secondary deoxygenation, and the infrared glass prepared therefrom had an obvious absorption peak between 12 and 14 μm, resulting in a significant reduction in the transmittance of the infrared glass prepared therefrom in the far-infrared region of 8 to 14 μm, affecting its use scenario.

Claims

1. A high refractive index infrared glass, characterized in that: The infrared glass comprises the following components by mole percentage: 16-28% Ge, 58-64% Te, 7-14% Se, 2-10% As and 0-2% Sb.

2. According to the high refractive index infrared glass described in claim 1, it is characterized in that: The refractive index of the infrared glass at 10 μm is 2.9-3.

4.

3. According to the high refractive index infrared glass described in claim 1, it is characterized in that: The infrared glass comprises the following components in terms of mole percentage: 23-25% Ge, 61-63% Te, 9-11% Se, 3-6% As and 0-0.2% Sb; the refractive index of the infrared glass at 10 μm is 3.1-3.

3.

4. The high refractive index infrared glass according to claim 1, characterized in that: The infrared transmittance of the infrared glass in the 4-16 μm band is 56-59%, and the infrared transmittance in the 8-14 μm band is 57-59%.

5. The high refractive index infrared glass according to claim 1, characterized in that: The softening temperature of the infrared glass is 150-240°C.

6. A method for preparing a high refractive index infrared glass as claimed in any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: Deoxygenation of raw materials: Deoxygenate the raw materials selenium, tellurium and arsenic in the purification tube and transfer them to an operating table protected by inert gas; Step 2, mixing raw materials: weighing and mixing the components according to the component ratio on an operating table protected by inert gas to obtain a mixture, then putting the mixture into a sealed bottle, and sealing the vacuum port in the sealed bottle; Step 3, heating and melting: transfer the sealed bottle to a melting furnace for heating and melting. Keep the sealing sheet shaking during the melting process. After the melting is completed, take out the sealed bottle for annealing. After the annealing is completed, an infrared glass ingot is obtained.

7. A method for preparing a high refractive index infrared glass according to claim 6, characterized in that: The deoxygenation of selenium and tellurium in step 1 comprises the following steps: placing selenium and tellurium in a quartz purification tube respectively and continuously introducing high-purity hydrogen, heating the selenium and tellurium to a molten state after the air in the tube is completely removed, stopping heating after the complete reaction and continuously introducing high-purity hydrogen, stopping ventilation after the temperature drops to room temperature, taking out the selenium and tellurium from the purification tube and quickly transferring them to an operating platform protected by inert gas.

8. The method for preparing a high refractive index infrared glass according to claim 6, characterized in that: The deoxygenation of arsenic in step 1 includes the following steps: placing arsenic in a quartz purification tube, evacuating it to below 10 Pa and then heating it to 300 degrees, keeping it warm at this temperature to react and remove oxygen from the arsenic, cooling it to room temperature after the reaction is completed, filling it with high-purity nitrogen to normal pressure, and then quickly taking out the arsenic and transferring it to an operating platform protected by inert gas.

9. The method for preparing a high refractive index infrared glass according to claim 6, characterized in that: The smelting temperature in step three is 850-1100° C., and the smelting time is 16-20 hours; the annealing temperature is 160-200° C., and the annealing rate is -10--1° C. / h.

10. Use of a high refractive index infrared glass as described in any one of claims 1 to 5 or prepared using any one of claims 6 to 9 in infrared thermal imaging equipment.

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