Ultraviolet-transmitting glass, preparation method thereof, and application thereof

Abstract

The present invention discloses a UV-transmitting glass, a preparation method thereof, and an application thereof. The preparation method of the UV-transmitting glass comprises: mixing raw materials comprising the following components: 30-50wt% P2O5, 10-20wt% SiO2, 5-10wt% Al2O3, 10-20wt% B2O3, 1-5wt% MgO, 5-10wt% CaO, 3-8wt% Li2O, 2-8wt% Y2O3, and 2-8wt% La2O3, totaling 100wt%; and adding an impurity scavenger, and melting under negative pressure, wherein the impurity scavenger comprises graphite and chloride. The present invention can significantly reduce the impurity content in the glass by rationally designing the components, adding the impurity scavenger, and melting at high temperature under vacuum, thereby achieving UV-transmitting glass with improved UV transmission performance, good chemical stability, and matching thermal expansion coefficient through simple process steps.

Description

Technical Field

[0001] The present invention relates to the technical field of ultraviolet-transmitting glass, and in particular to ultraviolet-transmitting glass, a preparation method thereof, and applications thereof. Background Art

[0002] Ultraviolet light is a ubiquitous electromagnetic wave found in nature, widely used in UV curing, missile warning, biomedicine, biological detection, non-line-of-sight secure communications, photocatalysis, and sterilization and purification. Due to the effects of atmospheric molecules and particles, ultraviolet light in the solar spectrum with wavelengths of approximately 200-280 nm is strongly absorbed by the ozone layer in the atmosphere, providing protection for humans. This portion of the ultraviolet spectrum is also known as the "solar blind zone." Ultraviolet radiation in this wavelength band is virtually absent in the near-Earth atmosphere. If ultraviolet signals are detected in the atmosphere, they can be confirmed to be generated by human activities, such as the launch of missiles, rockets, and other man-made aircraft. Therefore, the detection of ultraviolet light in the "solar blind zone" is of great significance.

[0003] Most colorless optical glasses have high transmittance for visible light, but have varying degrees of absorption of ultraviolet light. This is because the energy of ultraviolet light in the 200-280nm band is 4.4-6.2eV, while the band gap of ordinary optical glass is less than 4.4eV. Under the irradiation of high-energy ultraviolet light, electrons will be stimulated to jump between energy levels, thereby absorbing ultraviolet light. Therefore, ultraviolet light in this band is difficult to pass through ordinary glass. Only a few glasses containing special components have good ultraviolet transmittance. The ultraviolet transmittance cutoff wavelengths of single SiO2, B2O3 and P2O5 glasses are 160nm, 170nm and 145nm respectively, with high ultraviolet transmittance. Therefore, it is expected that high-performance ultraviolet-transmitting glass can be prepared by rationally designing the glass components.

[0004] Many factors influence the UV transmittance of UV-transmitting glass. Besides the glass composition, harmful impurities such as Fe are also a significant factor. Even small amounts of these impurities can significantly impact the glass's UV transmittance. Therefore, throughout the entire glass production process, harmful impurities must be minimized or removed to minimize their impact on glass performance. Summary of the Invention

[0005] In view of this, the main purpose of the present invention is to provide an ultraviolet-transmitting glass, a preparation method and application thereof. The technical problem to be solved is how to achieve the production of ultraviolet-transmitting glass with excellent ultraviolet transmission performance and a suitable thermal expansion coefficient while simplifying the process steps and reducing costs, so as to meet the requirements of the development of ultraviolet detection and other fields for ultraviolet-transmitting glass materials.

[0006] The purpose of the present invention and the technical problems solved therein are achieved by adopting the following technical solutions. According to the present invention, a method for preparing ultraviolet-transmitting glass is proposed, which comprises:

[0007] Mixing raw materials comprising 30-50 wt% of P2O5, 10-20 wt% of SiO2, 5-10 wt% of Al2O3, 10-20 wt% of B2O3, 1-5 wt% of MgO, 5-10 wt% of CaO, 3-8 wt% of Li2O, 2-8 wt% of Y2O3 and 2-8 wt% of La2O3, totaling 100 wt%; and

[0008] Add impurity remover and melt under negative pressure to obtain the ultraviolet transmitting glass.

[0009] Wherein, the impurity scavenger comprises graphite and chloride.

[0010] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0011] Preferably, the method for preparing the ultraviolet-transmitting glass comprises the following steps:

[0012] 1) Weighing the components of the raw materials according to the ratio and mixing;

[0013] 2) adding the impurity scavenger to obtain a mixture;

[0014] 3) placing the mixture in a melting furnace, evacuating the furnace, and melting the mixture under negative pressure to obtain a glass melt;

[0015] 4) The glass melt is clarified, formed into a material, and annealed to obtain the ultraviolet-transmitting glass.

[0016] Preferably, in the aforementioned method for preparing ultraviolet-transmitting glass, in step 2), the chloride is selected from at least one of sodium chloride, potassium chloride, ammonium chloride, calcium chloride, and magnesium chloride.

[0017] Preferably, in the aforementioned method for preparing ultraviolet-transmitting glass, in step 2), the amount of graphite used is 0.5-1.0 wt%, and the amount of chloride used is 0.3-0.8 wt%, based on the total weight of the raw materials.

[0018] Preferably, in the aforementioned method for preparing ultraviolet-transmitting glass, in step 3), the vacuum degree of the melting furnace is -0.05 MPa to -0.01 MPa.

[0019] Preferably, in the aforementioned method for preparing ultraviolet-transmitting glass, in step 3), the melting temperature is 1450-1550° C., and the melting time is 2-4 hours.

[0020] Preferably, in the aforementioned method for preparing ultraviolet-transmitting glass, in step 4), the annealing temperature is 490-530° C. and the time is 3-5 hours.

[0021] The purpose of the present invention and the solution of its technical problems are also achieved by the following technical solutions. According to the present invention, an ultraviolet-transmitting glass comprises, based on the components in the raw materials, 30-50wt% of P2O5, 10-20wt% of SiO2, 5-10wt% of Al2O3, 10-20wt% of B2O3, 1-5wt% of MgO, 5-10wt% of CaO, 3-8wt% of Li2O, 2-8wt% of Y2O3 and 2-8wt% of La2O3, totaling 100wt%.

[0022] Wherein, an impurity scavenger containing graphite and chloride is added to the raw material.

[0023] Wherein, the content of the impurity Fe element in the ultraviolet-transmitting glass in the form of Fe2O3 is less than 1.0 ppm, based on the total weight of the ultraviolet-transmitting glass.

[0024] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0025] Preferably, the aforementioned ultraviolet-transmitting glass is prepared by any of the methods described above.

[0026] Preferably, the thermal expansion coefficient of the aforementioned ultraviolet-transmitting glass is (50±1)×10 -7 / ℃, and the transmittance of ultraviolet rays in the wavelength range of 200-275nm is greater than 82% at a thickness of 2.0mm.

[0027] The purpose of the present invention and the technical problems solved therein are also achieved by the following technical solutions: An optical device according to the present invention includes a high UV transmittance window, a lamp tube or a camera lens, wherein the high UV transmittance window, lamp tube or camera lens comprises any of the above-mentioned UV transmittance glasses.

[0028] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0029] Preferably, the aforementioned optical device is an ultraviolet detector, a large-scale integrated circuit lithography, an ultraviolet optical lens or an ultraviolet spectrometer.

[0030] The present invention reduces or removes harmful impurities (such as iron) in the glass by rationally designing the glass components and introducing impurity scavengers, thereby producing high-performance UV-transmitting glass. P2O5 glass has a UV transmission cutoff wavelength of 145nm, high UV transmittance, and a large thermal expansion coefficient, but its chemical stability is poor, and pure phosphate glass has little practical value. Therefore, SiO2, which has good chemical stability and high UV transmittance, is introduced to prepare silicophosphate glass. At the same time, to ensure the stability of the glass structure, Al2O3 and Li2O are introduced to regulate the glass structure. Replacing P2O5 in the silicophosphate glass system with an appropriate amount of Li2O can change the network structure of the glass, giving it advantages such as good chemical stability, high deep UV transmittance (200-275nm band), and a thermal expansion coefficient that matches that of Kovar alloy. In addition to being related to the glass components, the actual UV transmittance of the glass is also affected by trace impurities, primarily variable valence ions of different valence states, including the transition metal Fe. These impurities may be introduced by the raw materials or contamination from melting technology and processing methods. The influence of trace impurities is deeply eliminated by introducing an impurity scavenger, which contains graphite and chloride, wherein graphite can act as a reducing agent to reduce Fe in the glass melt. 3+ , making it a single substance of Fe and precipitating it to the bottom of the crucible; at the same time, graphite can also form POC bonds in phosphates, and carbon atoms combined with the glass network can capture electrons in non-bridging oxygen, thereby improving the ultraviolet transmittance of the glass. Chlorides will react chemically with the iron element in the glass melt at high temperatures to form volatile reaction products. The combined action of graphite and chlorides can significantly reduce or even eliminate the influence of trace impurities on the ultraviolet transmittance of the glass, thereby improving the ultraviolet transmittance of the glass. In fact, in the impurity remover described in the present invention, graphite and chlorides show a certain synergistic effect in eliminating the influence of impurities and improving the performance of the glass. For example, when graphite and chlorides are used simultaneously to eliminate impurities, the ultraviolet transmittance of the glass is significantly better than the ultraviolet transmittance of the glass when graphite or chlorides are used alone.

[0031] By means of the above technical solution, the ultraviolet-transmitting glass of the present invention and its preparation method and application have at least the following beneficial effects:

[0032] The ultraviolet-transmitting glass and preparation method thereof described in the present invention, by rationally designing the glass components and contents, the glass prepared thereby has excellent ultraviolet transmission performance, and the thermal expansion coefficient matches the thermal expansion coefficient of Kovar alloy, which can meet the performance requirements of application fields such as ultraviolet detection.

[0033] The ultraviolet-transmitting glass and preparation method thereof disclosed in the present invention can efficiently and deeply separate harmful impurities from the glass melt by introducing an impurity scavenger and melting at high temperature under vacuum, without requiring prior iron removal treatment of the glass raw materials. This can reduce the number of glass preparation process steps, lower costs, and effectively improve the ultraviolet transmission performance of the glass.

[0034] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention. DETAILED DESCRIPTION

[0035] To further illustrate the technical means and effectiveness of the present invention in achieving its intended objectives, the following describes in detail the specific implementations, structures, features, and effectiveness of the polarizing glass, its preparation method, and its applications according to the present invention, in conjunction with preferred embodiments. In the following description, different references to "one embodiment" or "embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

[0036] In the examples of the present invention, unless otherwise specified, the materials and reagents involved are commercially available products familiar to those skilled in the art; unless otherwise specified, the methods involved are methods well known in the art. Unless otherwise defined, the technical or scientific terms used shall have the same meaning as those of ordinary skill in the art to which this invention belongs.

[0037] The present invention provides a method for preparing ultraviolet-transmitting glass, which comprises:

[0038] Mixing raw materials comprising 30-50 wt% of P2O5, 10-20 wt% of SiO2, 5-10 wt% of Al2O3, 10-20 wt% of B2O3, 1-5 wt% of MgO, 5-10 wt% of CaO, 3-8 wt% of Li2O, 2-8 wt% of Y2O3 and 2-8 wt% of La2O3, totaling 100 wt%; and

[0039] Add impurity remover and melt under negative pressure to obtain the ultraviolet transmitting glass.

[0040] Wherein, the impurity scavenger comprises graphite and chloride.

[0041] The functions of the components in the raw materials are as follows:

[0042] P2O5 is a network-forming oxide with a short UV cutoff wavelength of only 145nm. It forms the backbone of glass and is the primary component for improving UV transmittance. Within the glass network, P2O5 typically forms double-bonded [PO4] tetrahedrons, connected at their vertex angles. If the P2O5 content is less than 30wt%, high-transmittance UV glass is difficult to achieve. If the P2O5 content exceeds 50wt%, the glass's refractive index decreases and its thermal expansion coefficient increases, while the chemical stability and anti-devitrification properties of the glass decrease.

[0043] SiO2 has an ultraviolet transmission cutoff wavelength of 160nm, and has excellent ultraviolet transmission properties. It is the main component of the glass skeleton and can form a unified network within the glass. The silicon oxide tetrahedron and the phosphorus oxide tetrahedron are connected at the top corners, which shifts the ultraviolet transmission cutoff wavelength to a shorter wavelength. Introducing SiO2 into glass can improve the strength, viscosity and thermal stability of the glass and reduce the thermal expansion coefficient of the glass. If the SiO2 content is less than 10wt%, the overall performance of the glass will deteriorate, making it difficult to obtain glass with high transmittance. If the SiO2 content is higher than 20wt%, the temperature required during the glass melting process will be too high, and defects such as stones will be caused, thus affecting the final performance of the glass.

[0044] Al2O3 can form a network structure with SiO2, making the glass structure more compact and improving a range of glass properties. At the same time, Al2O3 can capture free oxygen in the glass to form aluminum oxide tetrahedra, which, similar to the structure of silicon oxide tetrahedra, can improve and strengthen the structure of phosphate glass, increasing the glass's ultraviolet transmittance and chemical stability. If the Al2O3 content is less than 5wt%, the internal network structure of the glass is low, and properties such as strength, viscosity, and ultraviolet transmittance are poor, while the network gaps are small. If the Al2O3 content is higher than 10wt%, the temperature required for glass melting is too high, which can cause defects such as stones, reduce the thermal expansion coefficient of the glass, and poor compatibility with Kovar alloy, thus affecting the final performance of the glass.

[0045] B2O3 has a UV cutoff wavelength of 170nm, effectively improving the UV transmittance of glass. It is a key component of glass and also serves as a good flux. B2O3 forms boron oxide tetrahedra in glass, compacting the structure and increasing the viscosity of the glass. Its introduction can repair broken network structures within the glass, strengthening the glass's three-dimensional skeleton and promoting UV transmission. A B2O3 content exceeding 20wt% results in excessively high temperatures during the glass melting process. Boron oxide appears in the glass structure as triangular boron oxides rather than tetrahedrons, weakening the glass structure and leading to performance degradation and phase separation. A B2O3 content below 10wt% prevents sufficient boron oxide tetrahedra from forming in the glass, causing the boron structure to shift from a layered to a framework-like structure. The broken network structure within the glass cannot be repaired, resulting in reduced UV transmission.

[0046] MgO is an oxide that is present in the glass network, raising the softening temperature and lowering the thermal expansion coefficient. Introducing MgO into glass containing P2O5 strengthens the structure. If the MgO content is less than 1wt%, the improvement is minimal. If the MgO content is above 5wt%, MgO tetrahedra enter the glass network, reducing the chemical stability and hardness of the glass.

[0047] CaO is an oxide in the glass network, increasing the chemical stability and mechanical strength of the glass. If the CaO content is less than 5wt%, the improvement is insignificant. If the CaO content is greater than 10wt%, the chemical stability of the glass is reduced and the tendency to crystallize is increased.

[0048] Li in Li2O + Its small ionic radius and high electric field strength improve the chemical stability and surface tension of the glass. It also acts as a high-temperature fluxing agent, reducing the glass's high-temperature viscosity. An appropriate amount of Li2O replacing P2O5 in a silicophosphate glass system can alter the glass's network structure, resulting in improved chemical stability and high deep-UV transmittance. When the glass system also contains B2O3 and SiO2, the added Li2O repairs the breakpoints between [PO4], [SiO4], and [BO3], strengthening the network and reducing the number of non-bridging oxygen atoms. However, increasing the amount of Li2O introduced breaks the network bonds, generating non-bridging oxygen atoms. Non-bridging oxygen atoms are closely linked to the UV transmittance of the glass: a higher amount of non-bridging oxygen decreases transmittance, while a lower amount increases it. Li2O content below 3wt% fails to achieve the desired effect. Above 8wt%, it severely corrodes the crucible and reduces the UV transmittance of the glass.

[0049] La2O3 is a lanthanide rare earth oxide, which is a high refractive index and low dispersion oxide. 3+The large ionic radius and strong electric field create a strong aggregation effect in the glass, which can increase the glass's refractive index and UV transmittance. If the La2O3 content is less than 2wt%, the effect of improving UV transmittance is not significant; if the La2O3 content is higher than 8wt%, the glass is prone to crystallization.

[0050] Y2O3, a rare earth oxide, increases the refractive index of glass, lowers its melting and crystallization temperatures, and increases its thermal expansion coefficient. If the Y2O3 content is less than 2wt%, the UV transmittance improvement is minimal. If the Y2O3 content is greater than 8wt%, the glass is prone to crystallization and has an excessively high thermal expansion coefficient, affecting compatibility with Kovar alloys.

[0051] In some embodiments, the method comprises the following steps:

[0052] 1) Weighing the components of the raw materials according to the ratio and mixing;

[0053] 2) adding the impurity scavenger to obtain a mixture;

[0054] 3) placing the mixture in a melting furnace, evacuating the furnace, and melting the mixture under negative pressure to obtain a glass melt;

[0055] 4) The glass melt is clarified, formed into a material, and annealed to obtain the ultraviolet-transmitting glass.

[0056] In step 2) of some embodiments, the chloride may be selected from at least one of sodium chloride, potassium chloride, ammonium chloride, calcium chloride, and magnesium chloride; the amount of graphite used is 0.5-1.0 wt%, and the amount of chloride used is 0.3-0.8 wt%, based on the total weight of the raw materials. Graphite can be used as a reducing agent to reduce the impurity Fe element in the glass melt, reducing it to elemental iron and precipitating it at the bottom of the crucible, thereby eliminating trace impurities introduced into the glass by the raw materials or during the melting process; at the same time, graphite can also form POC bonds in phosphates, and carbon atoms incorporated into the glass network can capture electrons from non-bridging oxygen, thereby improving the ultraviolet transmittance of the glass. If the graphite content is less than 0.5 wt%, the impurity removal effect is not significant, and the ultraviolet transmittance of the glass cannot be effectively improved; if the graphite content is higher than 1.0 wt%, the graphite reacts with the glass components to produce excessive bubbles, affecting the glass properties, and cannot be completely melted in the glass melt, thus forming stones or defects. At high temperatures, chloride reacts with iron in the molten glass to form volatile products, eliminating the iron impurity in the glass and improving its UV transmittance. If the chloride content is less than 0.3wt%, the impurity removal effect is insignificant. If the chloride content is greater than 0.8wt%, it will corrode the crucible and reduce the UV transmittance of the glass.

[0057] In step 3) of some embodiments, the vacuum level of the melting furnace is between -0.05 MPa and -0.01 MPa. Maintaining a certain vacuum level in the melting furnace during the glass melting process is intended to facilitate the volatilization of volatile substances generated by the reaction from the molten glass, thereby promoting the reduction or removal of iron impurities in the molten glass and improving the degree and efficiency of iron separation. If the vacuum level is greater than -0.01 MPa, the volatilization of volatile products from the iron impurities is not significantly promoted. If the vacuum level is less than -0.05 MPa, other substances in the molten glass will volatilize, which is not conducive to controlling the glass composition. Furthermore, the equipment requirements are high, resulting in increased costs and decreased efficiency.

[0058] In step 3) of some embodiments, the melting temperature is 1450-1550°C and the time is 2-4 hours. The glass components contain refractory components such as silicon oxide and aluminum oxide. If the melting temperature is lower than 1450°C, the viscosity of the glass is high, it is difficult to form a uniform glass melt, and the volatile substances produced are difficult to completely remove; if the melting temperature is higher than 1550°C, the volatility of the glass components will increase, thereby affecting the final composition of the glass and increasing energy consumption. If the melting time is less than 2 hours, the homogenization of the glass is not yet completed, affecting the uniformity of the glass; if the melting time is greater than 4 hours, the reaction is already completed, and further increasing the time will lead to reduced efficiency.

[0059] In step 4) of some embodiments, the annealing temperature is 490-530°C for 3-5 hours. The purpose of annealing is to eliminate internal stresses in the glass. Annealing temperatures below 490°C are inefficient; temperatures above 530°C are energy-intensive and generate new internal stresses in the glass. Annealing for less than 3 hours fails to eliminate internal stresses; and annealing for more than 5 hours does not further improve the internal stress elimination effect.

[0060] The present invention also provides an ultraviolet-transmitting glass, which comprises, based on the components in the raw materials, 30-50wt% of P2O5, 10-20wt% of SiO2, 5-10wt% of Al2O3, 10-20wt% of B2O3, 1-5wt% of MgO, 5-10wt% of CaO, 3-8wt% of Li2O, 2-8wt% of Y2O3 and 2-8wt% of La2O3, totaling 100wt%.

[0061] Wherein, an impurity scavenger containing graphite and chloride is added to the raw material.

[0062] Wherein, the content of the impurity Fe element in the ultraviolet-transmitting glass in the form of Fe2O3 is less than 1.0 ppm, based on the total weight of the ultraviolet-transmitting glass.

[0063] In some embodiments, the ultraviolet-transmitting glass is prepared by any of the methods described above.

[0064] As previously mentioned, the method for preparing ultraviolet-transmitting glass of the present invention uses an impurity scavenger to remove harmful impurities such as iron in the glass, wherein the impurity scavenger comprises graphite and chloride, which work together in different ways to deeply remove iron from the glass melt, thereby significantly reducing or even eliminating the effect of trace impurities on the ultraviolet transmission performance of the glass.

[0065] In some embodiments, the content of the impurity Fe element in the ultraviolet-transmitting glass in the form of Fe 2 O 3 is less than 1.0 ppm, based on the total weight of the ultraviolet-transmitting glass.

[0066] In some preferred embodiments, the content of the impurity Fe element in the ultraviolet transmitting glass in the form of Fe2O3 is less than 0.7 ppm, for example, less than 0.5 ppm or 0.1 ppm, based on the total weight of the ultraviolet transmitting glass.

[0067] In some embodiments, the thermal expansion coefficient of the ultraviolet-transmitting glass is (50±1)×10 -7 / ℃, and the transmittance of ultraviolet rays in the wavelength range of 200-275nm is greater than 82% at a thickness of 2.0mm.

[0068] The present invention also provides an optical device, which includes a high ultraviolet transmittance window, a lamp tube or a camera lens, wherein the high ultraviolet transmittance window, the lamp tube or the camera lens comprises any of the ultraviolet transmittance glasses described above.

[0069] In some embodiments, the optical devices are devices such as ultraviolet detectors, large-scale integrated circuit lithography, ultraviolet optical lenses, and ultraviolet spectrometers. The ultraviolet detectors can be used in ultraviolet early warning fields such as solar-blind ultraviolet missile warning systems, power grid security monitoring, and forest fire warnings; the large-scale integrated circuit lithography can be used in fields such as electronic communications; and the ultraviolet optical lenses and ultraviolet spectrometers can be used in fields such as ultraviolet optical performance testing or detection.

[0070] The present invention will be further described below with reference to specific embodiments, but these embodiments should not be construed as limiting the scope of protection of the present invention. Non-essential improvements and adjustments made by those skilled in the art based on the above-mentioned contents of the present invention still fall within the scope of protection of the present invention.

[0071] Transmittance test: Test the luminous flux or luminous energy of the incident light after it passes through the object, and compare the test value with the total luminous flux or luminous energy of the incident light itself to obtain the transmittance of the object. First, the luminous flux or luminous energy of the incident light is directly tested without passing through the sample to obtain reference light data; then the luminous flux or luminous energy of the incident light after it passes through the object is tested to obtain test light data. Specifically, the incident light is irradiated on the ultraviolet-transmitting glass prepared in each embodiment covering the light inlet, and the light passing through the glass prepared in each embodiment is collected and then enters the detector through the detection port. The detector is used to detect the outgoing light data, wherein the wavelength of the incident light used for the test is in the range of 160-1100nm.

[0072] Thermal Expansion Coefficient Test: The sample to be tested is placed in a heating furnace and heated. As the temperature rises, the sample expands, and this expansion is transmitted to the displacement sensor via the ejector pin. The displacement measured by the displacement sensor represents the thermal expansion change of the sample. As the furnace temperature rises, the system collects and processes the changing temperature and displacement signals, transmitting them to a computer in real time. The thermal expansion coefficient of the sample is calculated using the thermal expansion formula.

[0073] Test for Fe content in glass: Use a spectrophotometer to measure the stable absorption in the 700-1100nm region, calculate the difference in absorbance at 1050nm and 770nm, and calculate the mass content of ferrous iron in the glass based on the linear relationship between the mass content of ferrous iron and the absorbance difference; measure the transmittance curve in the 350-1050nm band, record the transmittance at 1000nm and 380nm, and calculate the mass content of ferric iron based on the formula for the ratio of ferrous iron to ferric iron; the sum of the above mass contents of ferrous iron and ferric iron is the total mass content of iron in the glass.

[0074] Example 1

[0075] According to the predetermined composition of the UV-transmitting glass, the raw materials were weighed and mixed uniformly: 50 wt% P2O5, 10 wt% SiO2, 10 wt% Al2O3, 16 wt% B2O3, 2 wt% MgO, 5 wt% CaO, 3 wt% Li2O, 2 wt% Y2O3, and 2 wt% La2O3, with 250 g of P2O5 weighed, and the remaining components adjusted accordingly. To the uniformly mixed raw materials, 0.5 wt% graphite and 0.3 wt% potassium chloride, based on the total weight of the raw materials, were added. The mixture was then melted in a melting furnace at 1500°C for 2 hours, maintaining a vacuum of -0.01 MPa. The resulting glass melt was clarified, formed by sintering, and then annealed at 490°C for 3 hours to produce the UV-transmitting glass. The test results show that the Fe content (calculated as Fe2O3) in the prepared UV-transmitting glass is 0.5ppm, the transmittance of UV rays in the 200-275nm band is 82.8% at a thickness of 2.0mm, and the thermal expansion coefficient is 50.5×10 -7 The ultraviolet-transmitting glass prepared above can be used as a high-ultraviolet-transmitting window of an ultraviolet detector.

[0076] Example 2

[0077] Ultraviolet-transmitting glass was prepared by the same process as in Example 1, except that the proportions of the raw materials were as shown in Table 1, with the weight of P2O5 being 225 g, and the remaining components corresponding thereto. Testing revealed that the Fe content (calculated as Fe2O3) in the prepared ultraviolet-transmitting glass was 0.4 ppm, the transmittance for ultraviolet radiation in the 200-275 nm wavelength range at a thickness of 2.0 mm was 82.5%, and the thermal expansion coefficient was 50.7 × 10 -7 The ultraviolet-transmitting glass prepared above can be used as a high-ultraviolet-transmitting window of an ultraviolet detector.

[0078] Example 3

[0079] Ultraviolet-transmitting glass was prepared by the same process as in Example 1, except that the amount of graphite added was as shown in Table 2, the weight of P2O5 was 250 g, and the remaining components were adjusted accordingly. Testing showed that the Fe content (calculated as Fe2O3) in the prepared ultraviolet-transmitting glass was 0.3 ppm, the transmittance for ultraviolet radiation in the 200-275 nm wavelength range was 83.0% at a thickness of 2.0 mm, and the thermal expansion coefficient was 50.3 × 10 -7 The ultraviolet-transmitting glass prepared above can be used as a high-ultraviolet-transmitting window of an ultraviolet detector.

[0080] Example 4

[0081] Ultraviolet-transmitting glass was prepared by the same process as described in Example 1, except that the amount of potassium chloride added was as shown in Table 2, the weight of P2O5 was 250 g, and the remaining components were adjusted accordingly. Testing showed that the Fe content (calculated as Fe2O3) in the prepared ultraviolet-transmitting glass was 0.5 ppm, the transmittance for ultraviolet light in the 200-275 nm wavelength range was 82.4% at a thickness of 2.0 mm, and the thermal expansion coefficient was 50.8 × 10 -7 The ultraviolet-transmitting glass prepared above can be used as a high-ultraviolet-transmitting window of an ultraviolet detector.

[0082] Example 5

[0083] Ultraviolet-transmitting glass was prepared by the same process as described in Example 1, except that the melting temperature and time were as shown in Table 2, the P2O5 weight was 250 g, and the remaining components were the same. Testing showed that the Fe content (calculated as Fe2O3) in the prepared ultraviolet-transmitting glass was 0.6 ppm, the transmittance for ultraviolet radiation in the 200-275 nm wavelength range was 82.2% at a thickness of 2.0 mm, and the thermal expansion coefficient was 50.8 × 10 -7 The ultraviolet-transmitting glass prepared above can be used as a high-ultraviolet-transmitting window of an ultraviolet detector.

[0084] Example 6

[0085] Ultraviolet-transmitting glass was prepared by the same process as described in Example 1, except that the degree of vacuum during the melting process was as shown in Table 2, the weight of P2O5 was 250 g, and the remaining components were the same. Testing showed that the Fe content (calculated as Fe2O3) in the prepared ultraviolet-transmitting glass was 0.6 ppm, the transmittance for ultraviolet light in the 200-275 nm wavelength range was 82.1% at a thickness of 2.0 mm, and the thermal expansion coefficient was 50.9 × 10 -7 The ultraviolet-transmitting glass prepared above can be used as a high-ultraviolet-transmitting window of an ultraviolet detector.

[0086] Example 7

[0087] Ultraviolet-transmitting glass was prepared by the same process as described in Example 1, except that the annealing temperature and time were as shown in Table 2, the P2O5 weight was 250 g, and the remaining components were the same. Testing showed that the Fe content (calculated as Fe2O3) in the prepared ultraviolet-transmitting glass was 0.5 ppm, the transmittance for ultraviolet radiation in the 200-275 nm wavelength range was 82.6% at a thickness of 2.0 mm, and the thermal expansion coefficient was 50.3 × 10 -7 The ultraviolet-transmitting glass prepared above can be used as a high-ultraviolet-transmitting window of an ultraviolet detector.

[0088] Example 8

[0089] Ultraviolet-transmitting glass was prepared by the same process as in Example 1, except that the proportions of the raw materials were as shown in Table 1, the P2O5 weight was 150 g, and the remaining components were the same. Testing showed that the Fe content (calculated as Fe2O3) in the prepared ultraviolet-transmitting glass was 0.6 ppm, the transmittance for ultraviolet radiation in the 200-275 nm wavelength range was 82.5% at a thickness of 2.0 mm, and the thermal expansion coefficient was 50.5 × 10 -7 The ultraviolet-transmitting glass prepared above can be used as a high-ultraviolet-transmitting window of an ultraviolet detector.

[0090] Example 9

[0091] Ultraviolet-transmitting glass was prepared by the same process as in Example 1, except that the proportions of the raw materials were as shown in Table 1, with the weight of P2O5 being 225 g, and the remaining components corresponding thereto. Testing revealed that the Fe content (calculated as Fe2O3) in the prepared ultraviolet-transmitting glass was 0.7 ppm, the transmittance for ultraviolet light in the 200-275 nm wavelength range at a thickness of 2.0 mm was 82.7%, and the thermal expansion coefficient was 50.1 × 10 -7 The ultraviolet-transmitting glass prepared above can be used as a high-ultraviolet-transmitting window of an ultraviolet detector.

[0092] Example 10

[0093] Ultraviolet-transmitting glass was prepared by the same process as in Example 1, except that the proportions of the raw materials were as shown in Table 1, the P2O5 weight was 250 g, and the remaining components were the same. Testing showed that the Fe content (calculated as Fe2O3) in the prepared ultraviolet-transmitting glass was 0.6 ppm, the transmittance for ultraviolet radiation in the 200-275 nm wavelength range was 82.9% at a thickness of 2.0 mm, and the thermal expansion coefficient was 50.1 × 10 -7 The ultraviolet-transmitting glass prepared above can be used as a high-ultraviolet-transmitting window of an ultraviolet detector.

[0094] Example 11

[0095] Ultraviolet-transmitting glass was prepared by the same process as in Example 1, except that the proportions of the raw materials were as shown in Table 1, with the weight of P2O5 being 225 g, and the remaining components corresponding thereto. Testing revealed that the Fe content (calculated as Fe2O3) in the prepared ultraviolet-transmitting glass was 0.4 ppm, the transmittance for ultraviolet radiation in the 200-275 nm wavelength range was 82.6% at a thickness of 2.0 mm, and the thermal expansion coefficient was 50.3 × 10 -7 The ultraviolet-transmitting glass prepared above can be used as a high-ultraviolet-transmitting window of an ultraviolet detector.

[0096] Example 12

[0097] Ultraviolet-transmitting glass was prepared by the same process as in Example 1, except that the proportions of the raw materials were as shown in Table 1, with the weight of P2O5 being 245 g, and the remaining components corresponding thereto. Testing revealed that the Fe content (as Fe2O3) in the prepared ultraviolet-transmitting glass was 0.5 ppm, the transmittance for ultraviolet radiation in the 200-275 nm wavelength range was 82.2% at a thickness of 2.0 mm, and the thermal expansion coefficient was 50.4 × 10 -7 / ℃. The ultraviolet-transmitting glass prepared above can be used as a high ultraviolet-transmitting window of an ultraviolet detector.

[0098] Example 13

[0099] Ultraviolet-transmitting glass was prepared by the same process as in Example 1, except that the proportions of the raw materials were as shown in Table 1, the weight of P2O5 was 240 g, and the remaining components were the same. Testing showed that the Fe content (calculated as Fe2O3) in the prepared ultraviolet-transmitting glass was 0.3 ppm, the transmittance for ultraviolet rays in the 200-275 nm wavelength range was 82.3% at a thickness of 2.0 mm, and the thermal expansion coefficient was 50.6 × 10 -7 / ℃. The ultraviolet-transmitting glass prepared above can be used as a high ultraviolet-transmitting window of an ultraviolet detector.

[0100] Example 14

[0101] Ultraviolet-transmitting glass was prepared by the same process as described in Example 1, except that the chloride species used were as shown in Table 2, the P2O5 weight was 250 g, and the remaining components were the same. Testing showed that the Fe content (calculated as Fe2O3) in the prepared ultraviolet-transmitting glass was 0.5 ppm, the transmittance for ultraviolet radiation in the 200-275 nm wavelength range was 82.8% at a thickness of 2.0 mm, and the thermal expansion coefficient was 50.7 × 10 -7 / ℃. The ultraviolet-transmitting glass prepared above can be used as a high ultraviolet-transmitting window of an ultraviolet detector.

[0102] Example 15

[0103] Ultraviolet-transmitting glass was prepared by the same process as described in Example 1, except that the chloride species used were as shown in Table 2, the P2O5 weight was 250 g, and the remaining components were the same. Testing showed that the Fe content (calculated as Fe2O3) in the prepared ultraviolet-transmitting glass was 0.7 ppm, the transmittance for ultraviolet radiation in the 200-275 nm wavelength range was 82.1% at a thickness of 2.0 mm, and the thermal expansion coefficient was 50.3 × 10 -7 / ℃. The ultraviolet-transmitting glass prepared above can be used as a high ultraviolet-transmitting window of an ultraviolet detector.

[0104] Example 16

[0105] Ultraviolet-transmitting glass was prepared by the same process as described in Example 1, except that the chloride species used were as shown in Table 2, the P2O5 weight was 250 g, and the remaining components were the same. Testing showed that the Fe content (calculated as Fe2O3) in the prepared ultraviolet-transmitting glass was 0.4 ppm, the transmittance for ultraviolet radiation in the 200-275 nm wavelength range was 82.3% at a thickness of 2.0 mm, and the thermal expansion coefficient was 50.6 × 10 -7 / ℃. The ultraviolet-transmitting glass prepared above can be used as a high ultraviolet-transmitting window of an ultraviolet detector.

[0106] Example 17

[0107] Ultraviolet-transmitting glass was prepared by the same process as described in Example 1, except that the chloride species used were as shown in Table 2, the P2O5 weight was 250 g, and the remaining components were the same. Testing showed that the Fe content (calculated as Fe2O3) in the prepared ultraviolet-transmitting glass was 0.7 ppm, the transmittance for ultraviolet radiation in the 200-275 nm wavelength range was 82.1% at a thickness of 2.0 mm, and the thermal expansion coefficient was 50.5 × 10 -7 / ℃. The ultraviolet-transmitting glass prepared above can be used as a high ultraviolet-transmitting window of an ultraviolet detector.

[0108] Example 18

[0109] Ultraviolet-transmitting glass was prepared by the same process as described in Example 1, except that the melting temperature and time were as shown in Table 2, the P2O5 weight was 250 g, and the remaining components were the same. Testing showed that the Fe content (calculated as Fe2O3) in the prepared ultraviolet-transmitting glass was 0.8 ppm, the transmittance for ultraviolet radiation in the 200-275 nm wavelength range was 82.5% at a thickness of 2.0 mm, and the thermal expansion coefficient was 50.6 × 10 -7 / ℃. The ultraviolet-transmitting glass prepared above can be used as a high ultraviolet-transmitting window of an ultraviolet detector.

[0110] Comparative Example 1

[0111] Glass samples were prepared using the same process as in Example 1, except that no graphite was added to the raw materials (as shown in Table 2). The P2O5 was weighed to 250 g, and the remaining components were adjusted accordingly. Testing revealed that the Fe content (as Fe2O3) in the prepared glass sample was 40 ppm, the transmittance to ultraviolet light in the 200-275 nm wavelength range was 34.0% at a thickness of 2.0 mm, and the thermal expansion coefficient was 50.9 × 10 -7 / ℃.

[0112] Comparative Example 2

[0113] Glass samples were prepared using the same process as in Example 1, except that no chloride was added to the raw materials (as shown in Table 2). The P2O5 was weighed to 250 g, and the remaining components were adjusted accordingly. Testing revealed that the Fe content (calculated as Fe2O3) in the prepared glass sample was 41 ppm, the transmittance to ultraviolet light in the 200-275 nm wavelength range was 39.8% at a thickness of 2.0 mm, and the thermal expansion coefficient was 51.1 × 10 -7 / ℃.

[0114] Comparative Example 3

[0115] Glass samples were prepared using the same process as in Example 1, except that the melting furnace was not evacuated (as shown in Table 2). The P2O5 was weighed to 250 g, and the remaining components were adjusted accordingly. Testing revealed that the Fe content (calculated as Fe2O3) in the prepared glass sample was 35 ppm, the transmittance to ultraviolet light in the 200-275 nm wavelength range was 41.1% at a thickness of 2.0 mm, and the thermal expansion coefficient was 51.2 × 10 -7 / ℃.

[0116] Comparative Example 4

[0117] Glass samples were prepared using the same process as in Example 1, except that no chloride was added, and the amount of graphite added was equivalent to the total amount of chloride and graphite added in Example 1 (as shown in Table 2). The P2O5 was weighed at 250 g, and the remaining components were adjusted accordingly. Testing revealed that the Fe content (calculated as Fe2O3) in the prepared glass sample was 28 ppm, the transmittance to ultraviolet light in the 200-275 nm wavelength range was 48.9% at a thickness of 2.0 mm, and the coefficient of thermal expansion was 51.2 × 10 -7 / ℃.

[0118] Comparative Example 5

[0119] Glass samples were prepared using the same process as in Example 1, except that no graphite was added, and the amount of chloride added was equivalent to the total amount of chloride and graphite added in Example 1 (as shown in Table 2). The P₂O₅ was weighed at 250 g, and the remaining components were adjusted accordingly. Testing revealed that the Fe content (as Fe₂O₃) in the prepared glass sample was 32 ppm, the transmittance to ultraviolet light in the 200-275 nm wavelength range was 43.8% at a thickness of 2.0 mm, and the thermal expansion coefficient was 51.3 × 10⁻¹. -7 / ℃.

[0120] Table 1 Ratio of raw material components of Examples 1-18 and Comparative Examples 1-5

[0121]

[0122]

[0123] Table 2 Preparation process conditions of Examples 1-18 and Comparative Examples 1-5

[0124]

[0125]

[0126] From the test data of Examples 1-18 above, it can be seen that the UV-transmitting glass prepared by the method of the present invention has a transmittance of more than 82% for UV rays in the 200-275 nm band at a thickness of 2.0 mm, and a thermal expansion coefficient of (50±1)×10 -7 / ℃.

[0127] The test data of Comparative Examples 1-3 show that, compared with Example 1, in Comparative Example 1, no graphite is added but only 0.3 wt% of chloride is added. The glass sample prepared at a thickness of 2.0 mm has a transmittance of 34.0% for ultraviolet rays in the 200-275 nm band and a thermal expansion coefficient of 50.9×10 -7 / ℃. In Comparative Example 2, no chloride was added but only 0.5wt% of graphite was added. The glass sample prepared had a transmittance of 39.8% for ultraviolet rays in the 200-275nm band at a thickness of 2.0mm and a thermal expansion coefficient of 51.1×10 -7 / ℃. In Comparative Example 3, the melting furnace was not vacuumed. The prepared glass sample had a transmittance of 41.1% for ultraviolet rays in the 200-275nm band at a thickness of 2.0mm, and a thermal expansion coefficient of 51.2×10 -7 / ℃.

[0128] In addition, the test data of Comparative Examples 4-5 show that in Comparative Example 4, the same total amount of single graphite is used to replace the chloride and graphite in Example 1. The prepared glass sample has a transmittance of 48.9% for ultraviolet rays in the 200-275 nm band at a thickness of 2.0 mm, and a thermal expansion coefficient of 51.2×10 -7 / ℃. In Comparative Example 5, the chloride and graphite in Example 1 were replaced by a single chloride in the same total amount. The prepared glass sample had a transmittance of 43.8% for ultraviolet rays in the 200-275nm band at a thickness of 2.0mm, and a thermal expansion coefficient of 51.3×10 -7 / ℃.

[0129] The ultraviolet-transmitting glass prepared in Examples 1-18 contained an impure Fe content of 0.3-0.8 ppm. The glass samples prepared in Comparative Examples 1-3 contained an impure Fe content of 35-41 ppm. The glass samples prepared in Comparative Examples 4-5 contained an impure Fe content of 28-32 ppm. This indicates that, compared to Comparative Examples 1-3 and 4-5, the method of the present invention can significantly reduce the Fe impurity content in ultraviolet-transmitting glass, even by two orders of magnitude.

[0130] Compared with the above comparative examples, in the embodiments of the present invention (e.g., Example 1), by rationally adjusting the glass composition, introducing an impurity scavenger to reduce or remove the content of harmful impurities such as iron in the glass, and maintaining a certain vacuum during the melting process, high-performance ultraviolet-transmitting glass is obtained. The prepared ultraviolet-transmitting glass has a transmittance of 82.8% for ultraviolet rays in the 200-275nm band at a thickness of 2.0 mm, and a thermal expansion coefficient of 50.5×10 -7 / ℃, the optical performance is greatly improved, and the thermal expansion coefficient is highly matched with Kovar alloy.

[0131] The technical features in the claims and / or the specification of the present invention may be combined, and the manner of combination is not limited to the combination obtained by reference in the claims. Technical solutions obtained by combining the technical features in the claims and / or the specification are also within the scope of protection of the present invention.

[0132] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A method for preparing ultraviolet-transmitting glass, characterized in that: include: Mixing raw materials comprising 30-50 wt% of P2O5, 10-20 wt% of SiO2, 5-10 wt% of Al2O3, 10-20 wt% of B2O3, 1-5 wt% of MgO, 5-10 wt% of CaO, 3-8 wt% of Li2O, 2-8 wt% of Y2O3 and 2-8 wt% of La2O3, totaling 100 wt%; and Add impurity remover and melt under negative pressure to obtain the ultraviolet transmitting glass. Wherein, the impurity scavenger comprises graphite and chloride.

2. The method according to claim 1, characterized in that The following steps are involved: 1) Weighing the components of the raw materials according to the ratio and mixing; 2) adding the impurity scavenger to obtain a mixture; 3) placing the mixture in a melting furnace, evacuating the furnace, and melting the mixture under negative pressure to obtain a glass melt; 4) The glass melt is clarified, formed into a material, and annealed to obtain the ultraviolet-transmitting glass.

3. The method according to claim 2, characterized in that In step 2), the chloride is selected from at least one of sodium chloride, potassium chloride, ammonium chloride, calcium chloride, and magnesium chloride.

4. The method according to claim 2, characterized in that In step 2), the amount of the graphite is 0.5-1.0 wt%, and the amount of the chloride is 0.3-0.8 wt%, based on the total weight of the raw materials.

5. The method according to claim 2, characterized in that In step 3), the vacuum degree of the melting furnace is -0.05 MPa to -0.01 MPa.

6. The method according to claim 2, characterized in that In step 3), the melting temperature is 1450-1550° C. and the melting time is 2-4 hours.

7. The method according to claim 2, characterized in that In step 4), the annealing temperature is 490-530° C. and the time is 3-5 hours.

8. An ultraviolet-transmitting glass, characterized in that: According to the components in the raw materials, it contains: 30-50wt% P2O5, 10-20wt% SiO2, 5-10wt% Al2O3, 10-20wt% B2O3, 1-5wt% MgO, 5-10wt% CaO, 3-8wt% Li2O, 2-8wt% Y2O3 and 2-8wt% La2O3, totaling 100wt%. Wherein, an impurity scavenger containing graphite and chloride is added to the raw material. Wherein, the content of the impurity Fe element in the ultraviolet-transmitting glass in the form of Fe2O3 is less than 1.0 ppm, based on the total weight of the ultraviolet-transmitting glass.

9. The ultraviolet-transmitting glass according to claim 8, characterized in that: Prepared by the method according to any one of claims 1 to 7.

10. The ultraviolet-transmitting glass according to claim 9, characterized in that: The thermal expansion coefficient of the ultraviolet-transmitting glass is (50±1)×10 -7 / ℃, and the transmittance of ultraviolet rays in the wavelength range of 200-275nm is greater than 82% at a thickness of 2.0mm.

11. An optical device, characterized in that: It comprises a high ultraviolet transmittance window, a lamp tube or a camera lens, wherein the high ultraviolet transmittance window, the lamp tube or the camera lens comprises the ultraviolet transmittance glass according to any one of claims 8 to 10.

12. The optical device according to claim 11, characterized in that The optical device is an ultraviolet detector, a large-scale integrated circuit lithography, an ultraviolet optical lens or an ultraviolet spectrometer.

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