Ultraviolet-visible transmitting glass

Abstract

To provide ultraviolet-visible transmitting glass which has high transmittance in an ultraviolet-visible region, hardly causes deterioration of the glass by ultraviolet light, can be press-molded, and has a low melting temperature.　An ultraviolet-visible transmitting glass according to the present invention includes a glass component containing 30 to 50% by weight of SiO(1)2(2), 16 to 30% by weight of Al(3)2(4)O(5)3(6), 20 to 40% by weight of B(7)2(8)O(9)3(10), 3 to 15% by weight of Li(11)2(12)O, a total of 10% by weight or less of Na(13)2(14)O and K(15)2(16)O, a total of 3 to 15% by weight of MgO, CaO, SrO, and BaO, 1% by weight or less of ZnO, and a total of 50 weight ppm or less of As(17)2(18)O(19)5(20), Sb(21)2(22)O(23)3(24), Fe(25)2(26)O(27)3(28), WO(29)3(30), PbO, CeO(31)2(32), and TiO(33)2(34), and has a transmittance of 85% or more at a wavelength of 250 nm.

Description

UV-transparent glass

[0001] This invention relates to ultraviolet-visible glass.

[0002] Currently, there are light sources with high output in the deep ultraviolet range (for example, wavelengths of 200-350 nm) that are used in various fields. In these fields, in addition to light sources, there is a need for materials that efficiently transmit light from ultraviolet to the visible range, and glass materials are particularly often used.

[0003] Conventionally, quartz glass (SiO₂) was used as a glass that transmits ultraviolet light. ２ Quartz glass is known to possess excellent light resistance, heat resistance, and corrosion resistance, as well as very high light transmittance from the ultraviolet to the near-infrared region. One known method for manufacturing quartz glass involves melting quartz powder at over 2000°C and then cooling it to vitrify it, but this method has the disadvantage of being difficult to manufacture due to the high temperature of the melting process. Other manufacturing methods include the CVD method and the sol-gel method, but these methods make it difficult to obtain large bulk materials.

[0004] As a glass that efficiently transmits ultraviolet and visible light, there is a type of glass that contains F or Cl in borosilicate glass, as disclosed in, for example, Patent Document 1 or Patent Document 2. While these glasses transmit more light from ultraviolet to visible ranges and have excellent corrosion resistance, the presence of F in these glasses poses a problem as it necessitates large-scale manufacturing equipment during the production process.

[0005] Glass from which F has been removed is known from Patent Document 3, etc., and is said to be glass that transmits more light from ultraviolet to visible range. However, when light containing ultraviolet light is transmitted for a long time, the energy of the ultraviolet light causes discoloration of the glass, and the transmission of light in the region from ultraviolet to visible range tends to decrease.

[0006] As an example of glass that transmits light even more efficiently, aluminoborsilicate glass disclosed in Patent Document 4 can be cited. Such glass transmits more light from the ultraviolet range to the visible range, and furthermore, even when light containing ultraviolet light is transmitted for a long time, the decrease in light transmission is suppressed. However, this glass composition requires a melting temperature of 1450°C or higher, and is highly viscous, making it difficult to mold. Another example of glass that transmits light efficiently is borosilicate glass proposed in Patent Document 5, but even with this glass composition, a melting temperature of 1500°C or higher is required, and it is highly viscous, making it difficult to mold.

[0007] Patent document 6 discloses a silicate glass that has a low melting point, good water resistance, and is easy to press-form. Although this glass has a low melting point, it does not actively transmit ultraviolet light, but rather transmits as much visible light as possible.

[0008] Patent No. 3192013 Patent No. 2528351 Japanese Patent Publication No. 3-218940 Patent No. 5904864 Patent No. 7289612 Patent No. 4143840

[0009] In recent years, there has been a demand for glass that has high transmittance in the ultraviolet to visible light range, is resistant to degradation by ultraviolet light, and has a low melting temperature that allows for press molding, for various applications.

[0010] The present invention has been made in view of the above, and aims to provide an ultraviolet-visible light-transmitting glass that has high transmittance in the ultraviolet to visible light region, is less susceptible to degradation by ultraviolet light, and has a low melting temperature that allows for press molding.

[0011] The inventors of this invention conducted extensive research to achieve the above objectives and, as a result, discovered that these objectives can be achieved by incorporating a specific glass component as an essential element, thus completing the present invention.

[0012] In other words, the present invention encompasses the subject matter described in the following sections, for example: Section 1: Ultraviolet-visible transparent glass containing a glass component, wherein the glass component comprises, with a total amount of 100% by weight, Component (1) SiO２ The content ratio of it is 30 to 50% by weight, and component (2) Al ２ O ３ The content ratio of is 16 to 30% by weight, and component (3) B ２ O ３ The content ratio of is 20 to 40% by weight, and component (4) Li ２ The content ratio of O is 3 to 15% by weight, and component (5) Na ２ O and K ２ The total content ratio of O is 10% by weight or less, the total content ratio of components (6) MgO, CaO, SrO and BaO is 3 to 15% by weight, the content ratio of component (7) ZnO is 1% by weight or less, and the total content ratio of components (8) As ２ [[ID=,17]]O ５ , Sb ２ O ３ , Fe ２ O ３ , WO ３ , PbO, CeO ２ and TiO ２ The total content ratio of is 50 ppm by weight or less, and the following physical property (1) Physical property (): In the transmittance measurement of irradiating light with wavelengths of 200 to 800 nm on an ultraviolet-visible transmitting glass with a thickness of 3 mm, the transmittance T １ (%) is 85% or more; An ultraviolet-visible transmitting glass that satisfies. Item 2 The following physical property (2) Physical property (2): After irradiating an ultraviolet-visible transmitting glass with a thickness of 3 mm with ultraviolet light having a wavelength of 265 nm, in the transmittance measurement of irradiating light with wavelengths of 200 to 800 nm on the ultraviolet-visible transmitting glass, when the transmittance at 250 nm is T ２ (%), the attenuation rate represented by the following formula (I) Attenuation rate (%) = (T １ - T ２ / T １ ) × 100 (I) is 7% or less; An ultraviolet-visible transmitting glass according to Item 1 that satisfies. Item 3 The following physical property (3) Physical property (3): In the transmittance measurement of irradiating light with wavelengths of 200 to 800 nm on an ultraviolet-visible transmitting glass with a thickness of 3 mm, the transmittance T ３The ultraviolet-visible transparent glass described in item 1 or 2 satisfies the condition that (%) is 70% or more. Item 4 The following physical properties (4) Physical properties (4): In a transmittance measurement in which light with a wavelength of 200 to 800 nm is incident on a 3 mm thick ultraviolet-visible transparent glass, the transmittance at a wavelength of 200 nm is T ４ UV-visible transparent glass as described in any one of items 1 to 3, satisfying the condition that (%) is 60% or more. Item 5 The following physical properties (5): Physical properties (5): The bending temperature is 600°C or less, and the coefficient of thermal expansion is 40 × 10 －７ / K to 70x10 －７ UV-visible transparent glass according to any one of items 1 to 4, satisfying the condition / K; Item 6 UV-visible transparent glass according to any one of items 1 to 5, which is glass for lens arrays, glass for spherical lenses, glass for aspherical lenses, glass for cylindrical lenses, glass for cylinders or glass for filters.

[0013] The ultraviolet-visible light-transmitting glass of the present invention has high transmittance in the ultraviolet to visible light region, is less susceptible to degradation due to ultraviolet light, and has a low melting temperature that allows for press molding.

[0014] This graph shows the spectral characteristics of each glass obtained in Example 1, Comparative Example 1, and Comparative Example 2. This graph shows the spectral characteristics of each glass obtained in Example 2 and Example 3, as well as the spectral characteristics after UV irradiation of each glass for 24 hours.

[0015] Embodiments of the present invention will be described in detail below. In this specification, the expressions "containing" and "including" include the concepts of "containing," "including," "substantially consisting of," and "consisting only of."

[0016] In the numerical ranges described stepwise in this specification, the upper or lower limit of a numerical range in one step can be arbitrarily combined with the upper or lower limit of a numerical range in another step. In the numerical ranges described in this specification, the upper or lower limit of a numerical range may be replaced with values ​​shown in the examples or values ​​that can be uniquely derived from the examples. Furthermore, in this specification, numbers connected by "~" mean a numerical range that includes the numbers before and after "~" as the lower and upper limits.

[0017] The present invention relates to an ultraviolet-visible transparent glass containing a glass component, wherein the glass component, with a total amount of 100% by weight, is: Component (1) SiO ２ The content ratio is 30-50% by weight, and component (2) Al ２ O ３ The content ratio is 16-30% by weight, and component (3) B ２ O ３ The content ratio is 20-40% by weight, and component (4) Li ２ The content of O is 3 to 15% by weight, and component (5) Na ２ O and K ２ The total content of O is 10% by weight or less, the content of components (6) MgO, CaO, SrO and BaO is 3 to 15% by weight, the content of component (7) ZnO is 1% by weight or less, and component (8) As ２ O ５ Sb ２ O ３ Fe ２ O ３ WO ３ PbO, CeO ２ and TiO ２ The total content is 50 ppm by weight or less. In addition, the ultraviolet-visible transparent glass of the present invention satisfies the following physical property (1). Physical property (1): In a transmittance measurement in which light with a wavelength of 200 to 800 nm is incident on a 3 mm thick ultraviolet-visible transparent glass, the transmittance at a wavelength of 250 nm T １ The percentage is 85% or higher.

[0018] The ultraviolet-visible transparent glass of the present invention contains glass components of a predetermined composition as described above, and satisfies physical property (1), thereby exhibiting high transmittance in the ultraviolet to visible light region (for example, light with a wavelength of 200 to 800 nm), and becoming less susceptible to degradation of the glass due to ultraviolet light, resulting in excellent solarization resistance of the ultraviolet-visible transparent glass. Moreover, the ultraviolet-visible transparent glass of the present invention, by containing glass components of a predetermined composition and satisfying physical property (1), can be manufactured at a low melting temperature, that is, it has a low melting temperature that allows for press molding.

[0019] In multi-component glass materials, each component interacts with the others to determine the inherent properties of the glass material. Therefore, it is not always appropriate to discuss the quantitative range of each component in terms of its properties. However, the rationale for defining the quantitative range of each component in the above composition is described below.

[0020] Component (1) Component (1) contained in the glass component is SiO ２ It is SiO ２ This is a component that makes up the glass network, and for example, it is a component that can improve the chemical durability of glass.

[0021] In the ultraviolet-visible transparent glass of the present invention, SiO in the glass component ２ The content ratio is 30 to 50% by weight (i.e., 30% or more and 50% or less by weight) when the total amount of glass components is considered to be 100% by weight. ２ If the content is less than 30% by weight, the chemical durability may be insufficient and discoloration may occur, and if it exceeds 50% by weight, the meltability of the glass may deteriorate. SiO in the glass components ２ The content of is preferably 33% by weight or more, more preferably 55% by weight or less, more preferably 50% by weight or less, and even more preferably 45% by weight or less, based on the total amount of glass components as 100% by weight.

[0022] Component (2) Component (2) contained in the glass component is Al ２ O ３ Al ２ O３ For example, it is a component that can suppress the devitrification of glass and improve its chemical durability.

[0023] In the ultraviolet-visible transparent glass of the present invention, Al in the glass component ２ O ３ The content ratio is 16 to 30% by weight (i.e., 16% or more and 30% or less by weight) when the total amount of glass components is considered to be 100% by weight. ２ O ３ If the content of is less than 16% by weight, the effects of the present invention may be inhibited, and if it exceeds 30% by weight, the meltability of the glass may deteriorate and it may become more prone to devitrification. ２ O ３ The content of is preferably 17% by weight or more, preferably 28% by weight or less, and more preferably 25% by weight or less, based on the total amount of glass components as 100% by weight.

[0024] Component (3) Component (3) contained in the glass component is B ２ O ３ B ２ O ３ For example, it is a component that makes up a glass network, and for example, it is a component that can improve the meltability of glass.

[0025] In the ultraviolet-visible transparent glass of the present invention, B in the glass component ２ O ３ The content ratio is 20 to 40% by weight (i.e., 20% or more and 40% or less by weight) when the total amount of glass components is considered to be 100% by weight. ２ O ３ If the content of is less than 20% by weight, the light transmission properties and the meltability of the glass may deteriorate, and if it exceeds 40% by weight, the chemical durability of the glass may be insufficient. ２ O ３ The content of is preferably 23% by weight or more, preferably 38% by weight or less, and more preferably 35% by weight or less, based on the total amount of glass components as 100% by weight.

[0026] Component (4) The component (4) contained in the glass component is Li ２ It is O. Li ２ O is, for example, a component that can improve the meltability of glass.

[0027] In the ultraviolet-visible transparent glass of the present invention, Li in the glass component ２ The content of O is 3 to 15% by weight (i.e., 3% or more and 15% or less by weight) when the total amount of glass components is considered to be 100% by weight. ２ If the O content is less than 3% by weight, the melting temperature will be high, which may make press molding difficult. ２ If the O content exceeds 15% by weight, the chemical durability of the glass may be insufficient. Li in the glass components ２ The content of O is preferably 3.5% by weight or more, more preferably 12% by weight or less, more preferably 10% by weight or less, and even more preferably 8% by weight or less, based on the total amount of glass components as 100% by weight.

[0028] Ingredient (5) Ingredient (5) is Na ２ O and / or K ２ It is O. However, component (5) does not have to be included in the glass component (i.e., Na ２ O and K ２ The content of O can be 0% by weight in all cases.

[0029] In the ultraviolet-visible glass of the present invention, Na in the glass component ２ O and K ２ If the total content of O exceeds 10% by weight, the transmittance T as defined in physical property (1) １ (%) decreases, meaning that transmittance in ultraviolet light decreases, and the coefficient of thermal expansion increases, and the melting temperature also increases, which may make press molding difficult. Na in the glass component ２ O and K ２ The total content of O is preferably 8% by weight or less, more preferably 6% by weight or less, even more preferably 5% by weight or less, even more preferably 4.5% by weight or less, and particularly preferably 4% by weight or less.

[0030] Na in the glass composition ２ The content ratio of O is preferably 8% by weight or less, more preferably 6% by weight or less, still more preferably 5% by weight or less, even more preferably 4.5% by weight or less, and particularly preferably 4% by weight or less, with the total amount of the glass composition being 100% by weight. K in the glass composition ２ The content ratio of O is preferably 5% by weight or less, more preferably 3% by weight or less, still more preferably 2% by weight or less, and even more preferably 1% by weight or less, with the total amount of the glass composition being 100% by weight. The glass composition may contain Na ２ O and may not contain K ２ O.

[0031] Component (6) The component (6) contained in the glass composition is at least one selected from the group consisting of MgO, CaO, SrO, and BaO.

[0032] In the ultraviolet and visible light transmitting glass of the present invention, the total content ratio of MgO, CaO, SrO, and BaO in the glass composition is 3 to 15% by weight (that is, 3% by weight or more and 15% by weight or less) with the total amount of the glass composition being 100% by weight. When the total content ratio of MgO, CaO, SrO, and BaO in the glass composition is less than 3% by weight, the transmittance T １ (%) becomes low, that is, the transmittance in ultraviolet light decreases, and the expansion coefficient becomes high. Also, if the total content ratio exceeds 15% by weight, the chemical durability of the glass may become insufficient.

[0033] The total content ratio of MgO, CaO, SrO, and BaO in the glass composition is preferably 12% by weight or less, more preferably 11% by weight or less, and still more preferably 10% by weight or less, with the total amount of the glass composition being 100% by weight.

[0034] The total content of MgO, CaO, SrO, and BaO in the glass component is preferably 3% by weight or more, more preferably 3.3% by weight or more, and even more preferably 3.5% by weight or more, based on 100% by weight of the total amount of glass component.

[0035] The component (6) contained in the glass component preferably contains at least MgO. In this case, the ultraviolet-visible transparent glass of the present invention has a transmittance T as defined in physical property (1). １ This makes it easier to meet the (%) requirement and also improves press formability.

[0036] Therefore, it is preferable that component (6) contained in the glass component contains MgO and one selected from the group consisting of CaO, SrO, and BaO. The content of MgO in component (6) is preferably 1% by weight or more, more preferably 1.5% by weight or more, and more preferably 5% by weight or less, and more preferably 4.5% by weight or less, based on the total amount of the glass component as 100% by weight.

[0037] Component (7) Component (7) is ZnO. ZnO is a component that can, for example, adjust the meltability of glass. However, component (7), i.e., ZnO, does not have to be included in the glass component (i.e., the ZnO content may be 0% by weight).

[0038] In the ultraviolet-visible transparent glass of the present invention, the content of ZnO in the glass component is 1% by weight or less, based on 100% by weight of the total amount of glass component. If the content of ZnO in the glass component exceeds 1% by weight, based on 100% by weight of the total amount of glass component, the transmittance T as defined in physical property (1) １ If the (%) becomes low, that is, the transmittance in ultraviolet light decreases, the melting temperature becomes too low and molding becomes difficult, and the coefficient of thermal expansion may also become too high. The content of ZnO in the glass component is preferably 0.5% by weight or less, more preferably 0.3% by weight or less, and even more preferably 0.1% by weight or less, based on the total amount of glass component as 100% by weight. It is particularly preferable that the ultraviolet-visible transparent glass of the present invention does not contain ZnO as a glass component.

[0039] Component (8) Component (8) is As ２ O ５ , Sb ２ O ３ , Fe ２ O ３ , WO ３ , PbO, CeO ２ and TiO ２ It is. However, component (8) may not be included in the glass component (that is, As ２ O ５ , Sb ２ O​​​​​​​​​​​​​​​​​​​​​​Therefore, in a preferred embodiment, the ultraviolet-visible light-transmitting glass of the present invention has components (1), (2), (3), (4), (5), and (6) as essential components. The ultraviolet-visible light-transmitting glass of this embodiment has particularly high transmittance in the ultraviolet to visible light region, is less susceptible to degradation of the glass due to ultraviolet light, and is particularly likely to have a low melting temperature that allows for press molding. Furthermore, in order to improve the transmittance in the ultraviolet-transmitting region, the ultraviolet-visible light-transmitting glass of the present invention may optionally have one or more reducing agents selected from the group consisting of organic raw materials, C (carbon), and metal raw materials added. By adding these components, the ultraviolet-transmitting region can be further improved. Examples of the metal raw materials include Al.

[0043] The ultraviolet-visible transparent glass of the present invention may contain other components as long as it contains the glass components described above. For example, the ultraviolet-visible transparent glass of the present invention may contain other additives as long as the effects of the present invention are not hindered, and may also contain additives other than the glass components contained in known ultraviolet-visible transparent glass.

[0044] The ultraviolet-visible transparent glass of the present invention preferably contains 80% by weight or more of the glass component, more preferably 90% by weight or more, even more preferably 95% by weight or more, and particularly preferably 98% by weight or more. The ultraviolet-visible transparent glass of the present invention may consist only of the glass component.

[0045] [Physical Properties (1)] The ultraviolet-visible transparent glass of the present invention satisfies the following physical properties (1) as described above. Physical properties (1): In a transmittance measurement in which light with a wavelength of 200 to 800 nm is incident on a 3 mm thick ultraviolet-visible transparent glass, the transmittance at a wavelength of 250 nm is T １ The percentage is 85% or higher.

[0046] The ultraviolet-visible transparent glass of the present invention satisfies physical property (1), making it less susceptible to degradation due to ultraviolet light. Transmittance T as defined by physical property (1) １There is no particular upper limit; for example, it could be 100%, or, taking into account ease of manufacture, it could be 95% or less.

[0047] Transmittance T as defined by physical property (1) １ The desired range can be adjusted by appropriately selecting the types and proportions of each component that make up the glass within the range described above.

[0048] [Physical Properties (2)] The ultraviolet-visible transparent glass of the present invention also preferably satisfies the following physical properties (2). Physical properties (2): In a transmittance measurement in which ultraviolet-visible transparent glass with a thickness of 3 mm is irradiated with ultraviolet light with a wavelength of 265 nm, and then light with a wavelength of 200 to 800 nm is incident on the ultraviolet-visible transparent glass, the transmittance at 250 nm is T ２ When expressed as (%), the following formula (I) is used: Damping rate (%) = (T １ -T ２ / T １ The attenuation rate, expressed as (I) × 100, is 7% or less.

[0049] When the ultraviolet-visible transparent glass of the present invention satisfies physical property (2), glass degradation due to ultraviolet light becomes particularly unlikely, and solarization resistance is excellent (i.e., it is more likely to have the property of being less prone to color change even when irradiated with ultraviolet light, etc.). The attenuation rate specified in physical property (2) is more preferably 6.5% or less, and the attenuation rate may be 0% or less.

[0050] The method for adjusting the decay rate represented by formula (I) is not particularly limited. For example, it can be adjusted to a desired range by appropriately selecting the type and content ratio of each component constituting the glass component within the above range.

[0051] [Physical Properties (3)] The ultraviolet-visible transparent glass of the present invention also preferably satisfies the following physical properties (3). Physical properties (3): In a transmittance measurement in which light with a wavelength of 200 to 800 nm is incident on a 3 mm thick ultraviolet-visible transparent glass, the transmittance at a wavelength of 220 nm T ３ The percentage is 70% or higher.

[0052] When the ultraviolet-visible transparent glass of the present invention satisfies physical property (3), glass degradation due to ultraviolet light, particularly in the deep ultraviolet region, becomes especially unlikely. Transmittance T as defined by physical property (3) ３ There is no particular upper limit; for example, it could be 100%, or, considering ease of manufacture, it could be 90% or less.

[0053] Transmittance T ３ The method of adjusting the glass components is not particularly limited; for example, the desired range can be achieved by appropriately selecting the types and proportions of each component that make up the glass components within the range described above.

[0054] [Physical Properties (4)] The ultraviolet-visible transparent glass of the present invention also preferably satisfies the following physical properties (4). Physical properties (4): In a transmittance measurement in which light with a wavelength of 200 to 800 nm is incident on a 3 mm thick ultraviolet-visible transparent glass, the transmittance at a wavelength of 200 nm T ４ The percentage is 60% or higher.

[0055] When the ultraviolet-visible transparent glass of the present invention satisfies physical property (4), glass degradation due to ultraviolet light, particularly in the deep ultraviolet region, becomes especially unlikely. Transmittance T as defined by physical property (4) ４ There is no particular upper limit; for example, it could be 100%, or, taking into account ease of manufacture, it could be 80% or less.

[0056] Transmittance T ４ The method of adjusting the glass components is not particularly limited; for example, the desired range can be achieved by appropriately selecting the types and proportions of each component that make up the glass components within the range described above.

[0057] [Physical Properties (5)] The ultraviolet-visible transparent glass of the present invention also preferably satisfies the following physical properties (5). Physical properties (5): The bending temperature is 600°C or less, and the coefficient of thermal expansion is 40 × 10 －７ / K to 70x10 －７ It is K.

[0058] When the ultraviolet-visible transparent glass of the present invention satisfies physical property (5), the dimensions of the glass are less likely to change even with temperature rise, and heat resistance and other properties are more easily improved. Generally, a lower bending temperature tends to result in a higher coefficient of thermal expansion, but in the present invention, the glass components are adjusted to predetermined components and proportions, resulting in a low coefficient of thermal expansion despite a low bending temperature.

[0059] The lower limit of the refractory temperature is not particularly limited. For example, it is 500°C or higher, preferably 550°C or higher, more preferably 560°C or higher, and even more preferably 570°C or higher.

[0060] The method for adjusting the bending temperature and thermal expansion coefficient defined in physical properties (5) is not particularly limited. For example, the desired range can be adjusted by appropriately selecting the type and content ratio of each component constituting the glass component within the above-mentioned range.

[0061] The ultraviolet-visible transparent glass of the present invention also preferably satisfies the following physical property (6). Physical property (6): Water resistance of grade 2 or higher in the international standard Optics and Photographs - Optical materials and components - The powder test method for the water resistance of optical glass.

[0062] If the ultraviolet-visible transparent glass of the present invention satisfies physical property (6), it will have excellent water resistance. The method for adjusting the water resistance defined in physical property (6) to grade 2 or higher is not particularly limited, and for example, it can be adjusted to the desired range by appropriately selecting the type and content ratio of each component constituting the glass component within the above range.

[0063] The ultraviolet-visible light-transmitting glass of the present invention, by containing a predetermined glass component, exhibits excellent transmittance of ultraviolet and visible light, and in particular, maintains excellent transmittance of ultraviolet and visible light even at large thicknesses (for example, 3 mm or more).

[0064] Furthermore, the ultraviolet-visible light-transmitting glass of the present invention can be manufactured at a low melting temperature by containing predetermined glass components, i.e., it has a low melting temperature, and the glass transition temperature is also adjusted to an appropriate range. Therefore, the ultraviolet-visible light-transmitting glass of the present invention has excellent press-molding properties. The ultraviolet-visible light-transmitting glass of the present invention preferably has a melting temperature of 1500°C or less, more preferably 1450°C or less, and even more preferably 1430°C or less. The lower limit of the melting temperature is not particularly limited, and for example, it is 1250°C or higher, preferably 1300°C or higher, and more preferably 1330°C or higher.

[0065] The glass transition temperature of the ultraviolet-visible transparent glass of the present invention is not particularly limited and can be, for example, 500°C or higher and 600°C or lower.

[0066] Applications of UV-Visible Transmitting Glass The UV-Visible transmitting glass of the present invention can be widely applied to various uses, for example, the same uses as those of conventional UV-Visible transmitting glass. For example, the UV-Visible transmitting glass of the present invention can be applied to various uses such as glass for lens arrays, glass for spherical lenses, glass for aspherical lenses, glass for cylindrical lenses, glass for cylinders, or glass for filters.

[0067] Furthermore, the ultraviolet-visible transparent glass of the present invention can also be applied to glass materials for ultraviolet germicidal lamps, optical filter materials, lighting filter materials, lens materials, photoresist exposure glass materials, and glass materials in exposure equipment for ultraviolet-curable resins.

[0068] The method for manufacturing the ultraviolet-visible transparent glass of the present invention is not particularly limited, and a wide range of manufacturing methods can be employed as long as the glass component contains the above-mentioned components in predetermined proportions. For example, the ultraviolet-visible transparent glass of the present invention can be manufactured using various raw materials containing glass components.

[0069] The types of raw materials used in the production of the ultraviolet-visible transparent glass of the present invention are not particularly limited. Examples include various compounds such as oxides, carbonates, sulfates, nitrates, and hydroxides corresponding to the metal elements contained in the raw materials of each component, with oxides being preferred.

[0070] The above raw materials are mixed in appropriate proportions and melted, for example, so that the glass components in the resulting ultraviolet-visible transparent glass have a predetermined composition. The melting temperature is not particularly limited and can be, for example, 1200 to 1500°C. After clarification, the molten raw materials are poured into a mold and cooled. During or after cooling, a heat treatment can be performed at a temperature of, for example, 450 to 700°C for 0.1 to 5 hours, followed by processing such as cutting and polishing. The cooling rate can be, for example, 10 to 100°C / hr, with 30 to 50°C / hr being preferred. The heating rate for the heat treatment can be 10 to 100°C / hr, with 30 to 70°C / hr being preferred.

[0071] As described above, the ultraviolet-visible transparent glass of the present invention can be obtained. Since such glass has a low melting temperature, it can be easily press-molded.

[0072] In specifying the inventions contained herein, the components (properties, structures, functions, etc.) described in each embodiment of this disclosure may be combined in any way. That is, this disclosure encompasses all subject matter consisting of any combination of the combinatable components described herein.

[0073] The present invention will be described more specifically below with reference to examples, but the present invention is not limited to the embodiments of these examples.

[0074] (Example 1) A raw material mixture was prepared by blending various raw materials in predetermined proportions to achieve the glass component composition shown in Table 1. This raw material mixture was melted in a quartz crucible at 1,400°C, and then clarified and stirred. The resulting molten material was poured into a carbon mold and cooled slowly to obtain glass. After cooling, the glass was cut and polished to obtain a 3 mm thick (wall thickness) ultraviolet-visible transparent glass material.

[0075] (Example 2) An ultraviolet-visible transparent glass material was obtained in the same manner as in Example 1, except that a raw material mixture was prepared by blending various raw materials in predetermined proportions to have the glass component composition shown in Table 1.

[0076] (Example 3) An ultraviolet-visible transparent glass material was obtained in the same manner as in Example 1, except that various raw materials were blended in predetermined proportions to obtain the glass component composition shown in Table 1, and the raw material mixture was prepared by melting it at 1,350°C.

[0077] (Comparative Example 1) An ultraviolet-visible transparent glass material was obtained in the same manner as in Example 1, except that various raw materials were blended in predetermined proportions to obtain the glass component composition shown in Table 1, and the raw material mixture was prepared by melting it at 1,450°C.

[0078] (Comparative Example 2) An ultraviolet-visible transparent glass material was obtained in the same manner as in Example 1, except that a raw material mixture was prepared by blending various raw materials in predetermined proportions so that the glass component composition shown in Table 1 was obtained.

[0079] (Evaluation Method) [Evaluation of Spectroscopic Characteristics] The spectral characteristics of the ultraviolet-visible transparent glass obtained in each example and comparative example were evaluated by irradiating it with light of wavelengths from 200 to 800 nm and measuring the transmittance at each wavelength. For the measurement, Hitachi High-Tech Corporation's "Ultraviolet-Visible Near-Infrared Spectrophotometer" was used, and the thickness of the test sample (ultraviolet-visible transparent glass) was set to 3 mm. Based on the measurement results from this spectrophotometer, the transmittance at 250 nm as defined in physical property (1) was set to T １ (%), transmittance T at a wavelength of 220 nm as defined in physical property (3) ３ (%) and the transmittance T at a wavelength of 200 nm as defined in physical property (4) ４ The transmittance (in percentage), transmittance at a wavelength of 300 nm, transmittance at a wavelength of 400 nm, and average transmittance from 300 nm to 800 nm were derived.

[0080] [Evaluation of Solarization Resistance] The ultraviolet-visible transparent glass obtained in each example and comparative example was used as a sample to evaluate its solarization resistance. Specifically, an LED lamp emitting a wavelength of 265 nm was used to irradiate the sample at an output of 3.4 W / h for 24 hours with the sample and LED in close contact. After irradiation, the sample was cooled for 30 minutes, and then the transmittance was measured in the same manner as in the spectral characteristics evaluation, and the transmittance T at 250 nm as defined in physical property (2) was measured. ２ Measure the (%) and use the following formula (I): Damping rate (%) = (T １ -T ２ / T １ The attenuation rate, represented by (I) × 100, was measured.

[0081] [Glass transition temperature, indentation temperature, and thermal expansion coefficient] The measurement methods for the glass transition temperature (°C), indentation temperature (°C), and thermal expansion coefficient were in accordance with the Nippon Optical Glass Manufacturers Association standard JOGIS 08:2019 (Method for measuring thermal expansion of optical glass).

[0082] (Evaluation Results) Table 1 shows the glass component composition of the ultraviolet-visible transparent glass obtained in each example and comparative example. Table 1 also shows the melting temperature (°C), glass transition temperature (°C), bending temperature (°C), and coefficient of thermal expansion (×10) of the ultraviolet-visible transparent glass obtained in each example and comparative example. －７ The results of the (K) and spectral characteristics evaluation are shown. Note that in the transmittance in Table 1, the transmittance at 200 nm is the transmittance T as defined in physical property (4). ４ (%) The transmittance at 220 nm is the transmittance T as defined in physical property (3). ３ (%) The transmittance at 250 nm is the transmittance T defined in physical property (1). ４ This refers to a percentage (%). Furthermore, the melting temperature refers to the furnace temperature at which the raw materials are melted during the manufacturing of ultraviolet-visible glass.

[0083] As shown in Table 1, the ultraviolet-visible transparent glass obtained in the examples consists of a predetermined glass component, and therefore can be manufactured at a low melting temperature (i.e., it is a glass with a low melting temperature), and the glass transition temperature is also adjusted to an appropriate range.

[0084]

[0085] Figure 1 shows the spectral characteristics of the glasses obtained in Example 1, Comparative Example 1, and Comparative Example 2, specifically a graph showing the relationship between wavelength and transmittance (%). From these results and the transmittance results for each wavelength shown in Table 1, it can be seen that the ultraviolet-visible light transmitting glass obtained in the examples is glass with high transmittance in the ultraviolet and visible light regions, and in particular, it has high transmittance in the deep ultraviolet region (200 nm to 350 nm).

[0086] Figure 2 shows the solarization resistance evaluation of the ultraviolet-visible transparent glass obtained in Example 2 and Example 3. Specifically, it is a graph showing the relationship between wavelength and transmittance (%) before and after ultraviolet irradiation for each of the ultraviolet-visible transparent glass obtained in Example 2 and Example 3.

[0087] Based on these results, the attenuation rate of transmittance at a wavelength of 250 nm was calculated from formula (I) above. It was found that the attenuation rate was 1% or less in Example 1 (however, Example 1 is not shown), the attenuation rate was 3% in Example 2, and the attenuation rate was 6% in Example 3. Therefore, it was found that all of the ultraviolet-visible transparent glass obtained in the examples showed very little degradation due to ultraviolet irradiation (i.e., the decrease in transmittance was suppressed).

[0088] Based on the above, the ultraviolet-visible light-transmitting glass obtained in the examples satisfies physical property (1), has high transmittance in the ultraviolet to visible light region, is resistant to degradation by ultraviolet light, and has a low melting temperature that allows for press molding. Furthermore, the ultraviolet-visible light-transmitting glass obtained in the examples also satisfies all of physical properties (2), (3), (4), and (5).

[0089] Comparative Example 1 did not satisfy the predetermined ratios of components (4), (5), (6), and (8), and Comparative Example 2 did not satisfy the predetermined ratios of components (6), (7), and (8). As a result, the transmittance in the deep ultraviolet region (200 nm to 350 nm) was low, making the glass susceptible to degradation due to ultraviolet light. Furthermore, the melting temperature was not within an appropriate range, resulting in poor press moldability.

Claims

1. An ultraviolet and visible light transmissive glass containing a glass component, wherein the glass component, with the total amount being 100% by weight, contains component (1) SiO ２ at a content ratio of 30 to 50% by weight, component (2) Al ２ O ３ at a content ratio of 16 to 30% by weight, component (3) B ２ O ３ at a content ratio of 20 to 40% by weight, component (4) Li ２ O at a content ratio of 3 to 15% by weight, component (5) Na ２ O and K ２ O with a total content ratio of 10% by weight or less, component (6) the total content ratio of MgO, CaO, SrO and BaO being 3 to 15% by weight, component (7) ZnO at a content ratio of 1% by weight or less, component (8) As ２ O ５ , Sb ２ O ３ , Fe ２ O ３ , WO ３ , PbO, CeO ２ and TiO ２ with a total content ratio of 50 ppm by weight or less, and having the following physical property (1): Physical property (1): In the measurement of the transmittance when light with a wavelength of 200 to 800 nm is incident on an ultraviolet and visible light transmissive glass with a thickness of 3 mm, the transmittance T １ (%) at a wavelength of 250 nm is 85% or more; An ultraviolet and visible light transmissive glass satisfying this.

2. Physical properties (2) Physical properties (2): In a transmittance measurement in which ultraviolet light with a wavelength of 265 nm is irradiated onto a 3 mm thick ultraviolet-visible transparent glass, and then light with a wavelength of 200 to 800 nm is incident on the same ultraviolet-visible transparent glass, the transmittance at 250 nm is T ２ When expressed as (%), the following formula (I) is used: Damping rate (%) = (T １ -T ２ / T １ The ultraviolet-visible transparent glass according to claim 1, satisfying the condition that the attenuation rate represented by ) × 100 (I) is 7% or less.

3. Physical properties (3) Physical properties (3): In a transmittance measurement where light with a wavelength of 200 to 800 nm is incident on a 3 mm thick ultraviolet-visible transparent glass, the transmittance T at a wavelength of 220 nm is... ３ The ultraviolet-visible transparent glass according to claim 1, satisfying the condition that (%) is 70% or more.

4. Physical properties (4) Physical property (4): In a transmittance measurement where light with a wavelength of 200 to 800 nm is incident on a 3 mm thick ultraviolet-visible transparent glass, the transmittance T at a wavelength of 200 nm is ４ The ultraviolet-visible transparent glass according to claim 1, satisfying the condition that (%) is 60% or more.

5. The following physical properties (5): Physical property (5): The flexing temperature is 600°C or less, and the coefficient of thermal expansion is 40 × 10⁻⁶. －７ / K to 70x10 －７ The ultraviolet-visible glass according to claim 1, satisfying the condition / K.

6. The ultraviolet-visible light-transmitting glass according to any one of claims 1 to 5, which is a glass for lens arrays, a glass for spherical lenses, a glass for aspherical lenses, a glass for cylindrical lenses, a glass for cylinders, or a glass for filters.

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