Glass, crystallized glass, heat-resistant material, and cookware top plate

Abstract

Provided is glass serving as an alternative to Li2O-A L2O3-SiO2-based crystallized glass, and more specifically, glass having a low coefficient of linear thermal expansion, low transmittance in the visible region, and high transmittance in the infrared region.　The glass is characterized by comprising, in mass%: SiO2: 45 to 80%; AL2O3: 1 to 30%; B2O3: 0 to 20%; and CuO: 0.1 to 20%.

Description

Glass, devitrified glass, heat-resistant material, and top plate for a cooker

[0001] The present invention relates to glass, devitrified glass, heat-resistant material, and a top plate for a cooker having low thermal expansion characteristics.

[0002] Conventionally, devitrified glass has been used as a material for front windows of oil stoves, wood stoves, etc., setter for firing electronic components, core tubes for semiconductor manufacturing, members for dimensional measurement, members for communication, members for construction, containers for chemical reactions, top plates for cookers, heat-resistant tableware, heat-resistant covers, window glass for fire doors, members for astronomical telescopes, materials for adjusting linear thermal expansion coefficient, etc. For example, in Patent Documents 1 to 3, β-quartz solid solution (Li ２ O·Al ２ O ３ ·nSiO ２ [where 2 ≤ n ≤ 4]) or β-spodumene solid solution (Li ２ O·Al ２ O ３ ·nSiO ２ [where n ≥ 4]) and other Li ２ O - Al ２ O ３ - SiO ２ - based crystals are disclosed.

[0003] The devitrified glass can control the type of precipitated crystals by appropriately adjusting the heat treatment conditions in the crystallization process, has a low linear thermal expansion coefficient and high mechanical strength, and can impart excellent thermal properties.

[0004] Japanese Patent Publication No. 39-21049, Japanese Patent Publication No. 40-20182, Japanese Patent Laid-Open No. 1-308845

[0005] In recent years, with the increasing demand for electric vehicles and electronic devices such as smartphones and tablets, the lithium-ion battery market has been expanding. Therefore, lithium raw materials are in short supply in various industries, and the price of lithium raw materials has been soaring globally. As a result, it has become difficult to stably manufacture and supply Li ２ O - Al ２ O ３ - SiO ２ - based devitrified glass to the market.

[0006] Given this background, Li ２ O-Al ２ O ３ -SiO ２ There is a need for materials with a low coefficient of linear thermal expansion to replace crystalline glass.

[0007] By the way, Li ２ O-Al ２ O ３ -SiO ２ Typical applications for crystallized glass include top plates for cookware equipped with electromagnetic or infrared heating devices. For these top plate applications, black is the most common color, and from an aesthetic standpoint, low transparency in the visible spectrum and a deep black appearance are preferred.

[0008] Furthermore, in the cooking appliances described above, there is a need to detect the temperature of the heated object in order to implement functions such as automatic temperature setting and overheat prevention. One method for detecting the temperature of the heated object is to detect the intensity of infrared radiation emitted from the heated object. When detecting the temperature of a heated object using infrared radiation, the infrared light emitted from the heated object passes through the top plate and is detected by a detection mechanism located on the underside of the top plate. Therefore, it is desirable that the top plate of a cooking appliance employing an infrared temperature detection method has high transmittance in the infrared range (e.g., 1500 nm). In other words, from the viewpoint of balancing functionality and design, a black top plate with low transmittance in the visible range and high transmittance in the infrared range is required.

[0009] The object of the present invention is Li ２ O-Al ２ O ３ -SiO ２ The objective is to provide a glass that can replace crystalline glass, and more specifically, a glass with a low coefficient of linear thermal expansion, low transmittance in the visible region, and high transmittance in the infrared region.

[0010] As a result of diligent research, the inventors have found that by appropriately designing the glass composition, it is possible to obtain glass with a low coefficient of linear thermal expansion, low transmittance in the visible region, and high transmittance in the infrared region. Note that transmittance in the visible region is represented by brightness L. ＊ It can be evaluated using values, and infrared transmittance can be evaluated using the total light transmittance at a wavelength of 1500 nm.

[0011] The glass of the present invention is composed of SiO by mass%. ２ 45-80%, Al ２ O ３ 1-30%, B ２ O ３ It is characterized by containing 0-20% and 0.1-20% CuO.

[0012] The glass of the present invention contains TiO by mass%. ２ It is preferable that it contains 0.1 to 20%.

[0013] The glass of the present invention is TiO ２ It is preferable that the CuO value is in the range of greater than 0 to 17.

[0014] The glass of the present invention is B by mass%. ２ O ３ Preferably, the content is more than 0% and 1% or more of CuO.

[0015] The glass of the present invention preferably has a BaO content of less than 1% by mass.

[0016] The glass of the present invention preferably has a ZnO content of less than 2% by mass.

[0017] The glass of the present invention uses MnO as a coloring component. ２ Fe ２ O ３ , Cr ２ O ３ NiO, Co ３ O ４ , V ２ O ５ , CEO ２ It is preferable to include at least one of the group consisting of the following:

[0018] The glass of the present invention preferably contains more than 0% MgO by mass.

[0019] The glass of the present invention is P by mass%. ２ O ５ It is preferable that it contains more than 0% of [the substance].

[0020] The glass of the present invention has a linear thermal expansion coefficient of 50 × 10 at 30 to 500°C. －７ It is preferable that the temperature is below / ℃.

[0021] The glass of the present invention has a thickness of 4 mm and L ＊ The value is preferably 30% or less.

[0022] The glass of the present invention preferably has a transmittance of 60% or more at a wavelength of 1500 nm with a thickness of 4 mm.

[0023] The glass of the present invention preferably has a glass transition temperature of 600°C or higher.

[0024] The glass of the present invention contains, by mass%, CuO 0.1 to 20%, TiO ２ It contains 0.1-20% and has a linear thermal expansion coefficient of 50 × 10 at 30-500°C. －７ It is preferable that the temperature is below / ℃.

[0025] The glass of the present invention contains, by mass%, CuO 0.1 to 20%, TiO ２ It contains 0.1-20%, and L in a thickness of 4 mm ＊ The value is preferably 30% or less.

[0026] The glass of the present invention contains, by mass%, CuO 0.1 to 20%, TiO ２ Preferably, it contains 0.1 to 20% and has a transmittance of 60% or more at a wavelength of 1500 nm at a thickness of 4 mm.

[0027] The glass of the present invention contains, by mass%, CuO 0.1 to 20%, TiO ２ It is preferable that it contains 0.1 to 20% and has a glass transition temperature of 600°C or higher.

[0028] The glass of the present invention may be crystallized glass.

[0029] The heat-resistant material of the present invention preferably comprises the above-mentioned glass.

[0030] The top plate for the cooking appliance of the present invention preferably comprises the above-mentioned glass.

[0031] According to the present invention, Li ２ O-Al ２ O ３ -SiO ２ This invention provides a glass with a low coefficient of linear thermal expansion, low transmittance in the visible region, and high transmittance in the infrared region, as an alternative to crystalline glass. Furthermore, according to this invention, it is also possible to provide glass that has any of the following properties: antibacterial, antiviral, deodorizing, or antifouling.

[0032] The glass of the present invention (hereinafter also simply referred to as "glass") is composed of SiO by mass%. ２ 45-80%, Al ２ O ３ 1-30%, B ２ O ３ It is characterized by containing 0-20% of CuO and 0.1-20% of CuO. The reasons for regulating the content of each component as described above are explained below. In the following explanation of the content of each component, unless otherwise specified, "%" means "mass%".

[0033] SiO ２ It is a component that forms the framework of glass. It is also a component that can be particularly involved in the likelihood of phase separation. SiO ２ The content is 45-80%, with a lower limit of 50% or more, preferably 55% or more, and particularly preferably 60% or more, and an upper limit of 77% or less, preferably 75% or less, preferably 73% or less, preferably 70% or less, and particularly preferably less than 70%. ２ If the content is too low, the coefficient of linear thermal expansion tends to increase, making it difficult to obtain glass with excellent heat resistance and thermal shock resistance. Also, chemical durability tends to decrease. On the other hand, SiO ２ If the content is too high, the homogeneity of the glass melt tends to decrease. Furthermore, SiO2 can form on the surface of the glass melt. ２Scum with a high content is likely to occur, and devitrification such as cristobalite precipitates from the scum, increasing the production load. Here, scum refers to unreacted substances and suspended matter on the surface of the glass melt in the melting furnace, and substances with cristobalite as the main component.

[0034] Al ２ O ３ forms the framework of the glass. It is also a component that can be involved in the ease of phase separation, etc. Al ２ O ３ content is 1 - 30%, and the lower limit is preferably 5% or more, 7% or more, particularly 9% or more, and the upper limit is preferably 25% or less, 22% or less, 20% or less, 15% or less, particularly less than 13%. When the content of Al ２ O ３ is too low, the linear thermal expansion coefficient tends to increase, and it becomes difficult to obtain glass with excellent heat resistance and thermal shock resistance. Also, the chemical durability decreases, and the glass surface is likely to deteriorate. As a result, the surface unevenness deteriorates, and it becomes difficult to obtain glass with the desired transmittance. On the other hand, when the content of Al ２ O ３ is too high, the homogeneity of the glass melt tends to decrease. Furthermore, crystals such as mullite tend to precipitate and the glass devitrifies, and the glass is likely to break.

[0035] B ２ O ３ is a component that reduces the viscosity of the glass, improving the melting and formability of the glass. It is also a component that can be particularly involved in the ease of phase separation. Furthermore, it has the effect of reducing the linear thermal expansion coefficient and enhancing heat resistance and thermal shock resistance. The content of B ２ O ３ is 0 - 20%, and the lower limit is preferably more than 0%, 0.05% or more, 1% or more, 3% or more, 6% or more, particularly more than 9%, and the upper limit is preferably 19% or less, 18% or less, particularly 17% or less. When the content of B ２ O ３ is too high, the evaporation amount of B ２ O ３ during melting increases, and on the surface of the glass melt, B ２ O ３The content of ２ is low, and the relative content of SiO ２ O ３ is high, making scum more likely to occur. As a result, devitrification such as cristobalite is likely to precipitate from the scum, increasing the manufacturing load. In addition, the chemical durability of the glass decreases, and the glass surface is likely to deteriorate, worsening the surface unevenness and making it difficult to obtain glass with a desired high transmittance. On the other hand, B ２ O ３ is likely to be mixed as an impurity. Therefore, if an attempt is made to completely remove B ２ O ３ , the raw material batch becomes expensive and the manufacturing cost tends to increase. When suppressing the increase in manufacturing cost, B ２ O ３ may be contained at 0.0001% or more, 0.0003% or more, particularly 0.0005% or more.

[0036] CuO is a component that, by containing an appropriate amount, reduces the viscosity of the glass and improves the melting property and formability of the glass. It is also a component that can participate in the phase separation of the glass. It is also a coloring component that absorbs light of various wavelengths. Furthermore, it is a component that imparts antibacterial, antiviral, deodorizing, and antifouling properties. The content of CuO is 0.1 to 20%, and the lower limit is preferably 0.3% or more, 0.5% or more, 1% or more, particularly 1.5% or more, and the upper limit is preferably 17% or less, 15% or less, 13% or less, 10% or less, 7% or less, 5% or less, 4% or less, particularly 3% or less. If the content of CuO is too high, the melting property of the glass is likely to decrease, and there is a risk of devitrification and cloudiness, or an increase in the linear thermal expansion coefficient. In addition, it becomes easier to color, and the transmittance in the visible region is low, but the transmittance in the infrared region is also likely to be low, making it difficult to obtain the desired optical properties. On the other hand, if the content of CuO is too low, the glass is less likely to be colored, and the transmittance in the visible region is likely to be high, making it difficult to obtain the desired optical properties. In addition, the antibacterial performance, antiviral performance, deodorizing performance, and antifouling performance are also likely to decrease.

[0037] The glass of the present invention may also contain the following components in addition to the above components.

[0038] TiO ２It is a component that, by containing an appropriate amount, reduces the viscosity of the glass, improves the melting property and formability of the glass. It is also a component that increases the linear thermal expansion coefficient. It is also a coloring component of the glass that absorbs light in the short wavelength range. Furthermore, when coexisting with transition metal elements, it has an effect of strengthening the coloring. For example, when titanium and iron coexist, ilmenite (FeTiO ３ ), such coloring appears, and when titanium and tin coexist, it is known that the yellow intensifies. Also, when titanium and copper coexist, the glass is likely to be colored. Furthermore, TiO ２ is also a component that can be particularly involved in the ease of phase separation. The content of TiO ２ is preferably 0.1% or more, 1% or more, 2% or more, 3% or more, particularly preferably 4% or more, and preferably 20% or less, 16% or less, 14% or less, particularly preferably 10% or less. If the content of TiO ２ is too high, not only is the melting property of the glass likely to decrease, but there is also a risk of devitrification and clouding, or an increase in the linear expansion coefficient. If the content of TiO ２ is too low, the glass is less likely to be colored, and the transmittance in the visible region is likely to be high, so it is difficult to obtain the desired optical properties.

[0039] When TiO ２ and CuO coexist, the glass is likely to be colored. Therefore, by controlling the ratio TiO ２ / CuO (hereinafter, TiO ２ / CuO) of the content of TiO ２ to the content of CuO, the transmittance of the glass in the visible light region can be reduced, and the transmittance in the infrared region can be improved. TiO ２ / CuO is preferably more than 0, 1 or more, 2 or more, 2.5 or more, particularly preferably 3 or more, and preferably 17 or less, 10 or less, 8 or less, 6 or less, particularly preferably 5 or less. If TiO ２ / CuO is too large, it is difficult to obtain the desired optical properties, and it is difficult to obtain the effects of antibacterial property, antiviral property, deodorizing property, and antifouling property. On the other hand, if TiO ２ / CuO is too small, the linear thermal expansion coefficient is likely to increase, and it is difficult to obtain the desired optical properties.

[0040] ZnO is a component that reduces the viscosity of glass, improving its meltability and moldability. It is also a component that adjusts the linear thermal expansion coefficient and refractive index of glass. Furthermore, it is a component that can be involved in the phase separation of glass. The ZnO content is preferably 0% or more, greater than 0%, 0.5% or more, 1% or more, and particularly preferably 5% or more, and preferably 20% or less, 18% or less, 17% or less, 15% or less, 13% or less, 12% or less, and particularly preferably 11% or less. If the ZnO content is too high, the glass is more likely to separate into phases. As a result, the homogeneity of the glass melt tends to decrease, and the glass may unintentionally become cloudy, making it difficult to obtain the desired optical properties. Therefore, in particular when suppressing the phase separation of glass and reducing the risk of glass clouding, the ZnO content is preferably 3% or less, less than 2%, 1% or less, 0.5% or less, and particularly preferably none.

[0041] P ２ O ５ In the glass of this invention, P is a component that reduces the linear thermal expansion coefficient of the glass. It is also a component that adjusts the refractive index of the glass. Furthermore, it is a component that may be involved in the phase separation of the glass. ２ O ５ The content is preferably 0-30%. The upper limit is preferably 25% or less, 20% or less, 15% or less, 10% or less, 5% or less, and especially preferably 3% or less. ２ O ５ If the content is too high, the viscosity of the glass becomes too high, making it easier for the homogeneity of the glass melt to decrease. Furthermore, the chemical durability of the glass tends to decrease. Additionally, its resistance to devitrification tends to decrease. ２ O ５ Attempting to completely remove P tends to increase the cost of raw material batches and thus the overall manufacturing cost. Therefore, to suppress the increase in manufacturing costs, ２ O ５ The lower limit of the content is preferably greater than 0%, 0.0001% or more, 0.0005% or more, 0.001% or more, and especially 0.01% or more.

[0042] Na ２O is a component that reduces the viscosity of glass, improving its meltability and moldability. It is also a component that adjusts the linear thermal expansion coefficient and refractive index of glass, and can be involved in the phase separation of glass. Na ２ The O content is preferably 15% or less, 10% or less, 7% or less, 5% or less, 3% or less, 2% or less, 1% or less, 0.7% or less, 0.4% or less, 0.1% or less, and especially preferably 0.05% or less. ２ If the O content is too high, the coefficient of linear thermal expansion becomes too high, making it difficult to obtain glass with excellent heat resistance and thermal shock resistance. Furthermore, the homogeneity of the glass melt tends to decrease. In addition, the chemical durability of the glass tends to decrease. ２ O is easily mixed in as an impurity, so Na ２ Attempting to completely remove oxygen tends to increase the cost of raw material batches and thus the overall manufacturing cost. To suppress the increase in manufacturing costs, Na ２ The lower limit of the O content is preferably greater than 0%, 0.0001% or more, 0.0003% or more, 0.0005% or more, 0.001% or more, 0.002% or more, 0.004% or more, 0.006% or more, 0.008% or more, and especially preferably 0.01% or more.

[0043] K ２ O is a component that reduces the viscosity of glass, improving its meltability and moldability. It is also a component that adjusts the linear thermal expansion coefficient and refractive index of glass, and can be involved in the phase separation of glass. K ２ The O content is preferably 15% or less, 10% or less, 7% or less, 5% or less, 3% or less, 2% or less, 1% or less, 0.7% or less, 0.4% or less, 0.1% or less, and especially preferably 0.05% or less. ２ If the O content is too high, the coefficient of linear thermal expansion becomes too high, making it difficult to obtain glass with excellent heat resistance and thermal shock resistance. Furthermore, the homogeneity of the glass melt tends to decrease. In addition, the chemical durability of the glass tends to decrease. ２ O is easily mixed in as an impurity, so K ２ Attempting to completely remove O tends to increase the cost of raw material batches and thus the overall manufacturing cost. To suppress the increase in manufacturing costs, K２ The lower limit of the O content is preferably greater than 0%, 0.0001% or more, 0.0003% or more, 0.0005% or more, and especially preferably 0.001% or more.

[0044] Li ２ O is a component that reduces the viscosity of glass, improving its meltability and moldability. It is also a component that can be involved in the phase separation of glass. Li ２ The O content is preferably 0-5%, with upper limits being 4.5% or less, 4% or less, 3.5% or less, 3% or less, 2.5% or less, 2% or less, less than 2%, 1.5% or less, 1% or less, 0.7% or less, 0.5% or less, 0.4% or less, 0.3% or less, 0.2% or less, 0.1% or less, and particularly preferably 0.05% or less. ２ If the oxygen content is too high, the coefficient of linear thermal expansion becomes too high, making it difficult to obtain glass with excellent heat resistance and thermal shock resistance. Furthermore, the homogeneity of the glass melt tends to decrease. In addition, the chemical durability of the glass tends to decrease. ２ O is easily mixed in as an impurity, Li ２ Attempting to completely remove oxygen tends to increase the cost of raw material batches and thus the overall manufacturing cost. Therefore, to suppress the increase in manufacturing costs, Li ２ The lower limit of the O content is preferably more than 0%, 0.0001% or more, 0.0002% or more, 0.0003% or more, 0.0004% or more, 0.0005% or more, and especially preferably 0.001% or more.

[0045] MgO is a component that reduces the viscosity of glass, improving its meltability and moldability. It is also a component that reduces the coefficient of linear thermal expansion of glass and adjusts the refractive index. Furthermore, it is a component that can be involved in the phase separation of glass. The MgO content is preferably more than 0%, 0.01% or more, 0.1% or more, and particularly preferably 1% or more, and preferably 20% or less, 14% or less, 10% or less, 7% or less, and particularly preferably 5% or less. If the MgO content is too high, the coefficient of linear thermal expansion will become too high, making it difficult to obtain glass with excellent heat resistance and thermal shock resistance. In addition, the chemical durability of the glass tends to decrease. Since MgO is easily mixed in as an impurity, if MgO is to be completely removed, the raw material batch will become expensive and the manufacturing cost tends to increase. To suppress the increase in manufacturing cost, the lower limit of the MgO content is preferably 0.0001% or more, 0.001% or more, and particularly preferably 0.01% or more.

[0046] CaO is a component that reduces the viscosity of glass, improving its meltability and moldability. It is also a component that adjusts the linear thermal expansion coefficient and refractive index of glass. Furthermore, it is a component that can be involved in the phase separation of glass. The CaO content is preferably 15% or less, 10% or less, 7% or less, 5% or less, 3% or less, 2% or less, 1% or less, 0.7% or less, and especially 0.5% or less. If the CaO content is too high, the linear thermal expansion coefficient becomes too high, making it difficult to obtain glass with excellent heat resistance and thermal shock resistance. In addition, the homogeneity of the glass melt tends to decrease. Also, the chemical durability of the glass tends to decrease. Since CaO is easily mixed in as an impurity, if CaO is to be completely removed, the raw material batch tends to become expensive and the manufacturing cost tends to increase. To suppress the increase in manufacturing cost, the lower limit of the CaO content is preferably 0.0001% or more, 0.001% or more, and especially 0.01% or more.

[0047] SrO is a component that reduces the viscosity of glass, improving its meltability and moldability. It is also a component that adjusts the linear thermal expansion coefficient and refractive index of glass. Furthermore, it is a component that can be involved in the phase separation of glass. The SrO content is preferably 15% or less, 10% or less, 7% or less, 5% or less, 3% or less, 2% or less, 1% or less, 0.7% or less, 0.4% or less, 0.1% or less, and especially 0.05% or less. If the SrO content is too high, the linear thermal expansion coefficient becomes too high, making it difficult to obtain glass with excellent heat resistance and thermal shock resistance. In addition, the homogeneity of the glass melt tends to decrease. Furthermore, the chemical durability of the glass tends to decrease. Note that since SrO is easily mixed in as an impurity, if SrO is to be completely removed, the raw material batch tends to become expensive and the manufacturing cost tends to increase. To suppress increases in manufacturing costs, the lower limit of the SrO content is preferably 0.0001% or more, 0.001% or more, and particularly 0.01% or more.

[0048] BaO is a component that reduces the viscosity of glass, improving its meltability and moldability. It is also a component that adjusts the linear thermal expansion coefficient and refractive index of glass. Furthermore, it is a component that can be involved in the phase separation of glass. The BaO content is preferably 15% or less, 10% or less, 7% or less, 5% or less, 3% or less, 2% or less, 1% or less, less than 1%, 0.7% or less, 0.4% or less, 0.1% or less, and especially 0.05% or less. If the BaO content is too high, the linear thermal expansion coefficient becomes too high, making it difficult to obtain glass with excellent heat resistance and thermal shock resistance. In addition, the meltability of the glass tends to decrease. Furthermore, the chemical durability of the glass tends to decrease. Note that since BaO is easily mixed in as an impurity, if BaO is to be completely removed, the raw material batch tends to become expensive and the manufacturing cost tends to increase. To suppress increases in manufacturing costs, the lower limit of the BaO content is preferably 0.0001% or more, 0.001% or more, and particularly 0.01% or more.

[0049] ZrO ２ZrO is a component that improves the Young's modulus and shear modulus of glass. It is also a component that adjusts the linear thermal expansion coefficient and refractive index. Furthermore, it is a component that can be involved in the phase separation of glass. ２ The content of ZrO is preferably 0% or more, more than 0%, particularly 0.1% or more, and preferably 20% or less, 14% or less, 10% or less, particularly 5% or less. ２ If the content is too high, devitrification increases, making it difficult to obtain glass with excellent heat resistance and thermal shock resistance. Furthermore, the homogeneity of the glass melt decreases, making it difficult to melt, the viscosity increases, making it difficult to clarify, and the molding of the glass becomes difficult, leading to a decrease in productivity.

[0050] SnO ２ It is a component that acts as a clarifying agent. It is also a component that adjusts the linear thermal expansion coefficient and refractive index of glass. Furthermore, it is a component that can be involved in the phase separation of glass. SnO ２ The content of is preferably 0% or more, greater than 0%, 0.005% or more, 0.01% or more, 0.03% or more, 0.05% or more, and especially preferably 0.1% or more. ２ There is no specific upper limit on the content, but in reality, it is 20%. If the content exceeds 20%, devitrification containing Sn will precipitate, which tends to increase the manufacturing burden. Also, SnO ２ If the content is too high, the coefficient of linear thermal expansion becomes too high, making it difficult to obtain glass with excellent heat resistance and thermal shock resistance. Furthermore, the homogeneity of the glass melt tends to decrease. In addition, the chemical durability of the glass tends to decrease.

[0051] Fe ２ O ３ This component, when included in an appropriate amount, reduces the viscosity of the glass, improving its meltability and moldability. It also releases oxygen-based gases through oxidation-reduction reactions, potentially contributing to the clarity of the glass. Furthermore, it is a coloring component of the glass that absorbs light of various wavelengths, and may also be involved in the phase separation of the glass. Fe ２ O ３ The content of is 0% or more, but Fe ２ O ３If the content is too low, the glass will not color well and it will be difficult to obtain the desired optical properties, so it is preferable that it be greater than 0%, 0.001% or more, and especially 0.005% or more. On the other hand, Fe ２ O ３ If the Fe content is too high, the glass becomes more prone to discoloration, and the transmittance in the visible range tends to decrease, but the transmittance in the infrared range also tends to decrease, making it difficult to obtain the desired optical properties. In addition, devitrification containing Fe tends to precipitate, increasing the manufacturing burden. Therefore, Fe ２ O ３ The content is preferably 20% or less, 15% or less, 10% or less, 5% or less, and especially 3% or less.

[0052] NiO is a component that, when included in an appropriate amount, reduces the viscosity of glass, thereby improving its meltability and moldability. It is also a component that can be involved in the phase separation of glass. Furthermore, it is a coloring component of glass that absorbs light of various wavelengths. Therefore, for example, NiO may be included to adjust the transmission properties of glass, and the NiO content is preferably more than 0%, particularly preferably 0.01% or more, preferably 7% or less, and particularly preferably 5% or less. If the NiO content is too high, the meltability of the glass tends to decrease. In addition, the glass tends to become more colored, and the transmittance in the visible range tends to decrease, but the transmittance in the infrared range also tends to decrease, making it difficult to obtain the desired optical properties.

[0053] Co ３ O ４ It is a component that, when included in an appropriate amount, reduces the viscosity of glass and improves its meltability and moldability. It is also a component that can be involved in the phase separation of glass. Furthermore, it is a coloring component of glass that absorbs light of various wavelengths. Therefore, for example, to adjust the transmission properties of glass, Co ３ O ４ It may contain Co ３ O ４ The content is preferably more than 0%, particularly preferably 0.05% or more, preferably 7% or less, and particularly preferably 5% or less. ３ O ４If the content is too high, the transmittance in the visible region tends to decrease, but the transmittance in the infrared region also tends to decrease, making it difficult to obtain the desired optical properties.

[0054] CEO ２ It is a component that, when included in an appropriate amount, reduces the viscosity of glass and improves its meltability and moldability. It is also a component that can be involved in the phase separation of glass. Furthermore, it is a coloring component of glass that absorbs light of various wavelengths. ２ The content is preferably more than 0%, particularly preferably 0.1% or more, preferably 5% or less, and particularly preferably 3% or less. ２ If the content is too high, the melting properties of the glass tend to decrease. Furthermore, the glass becomes more prone to discoloration, making it difficult to obtain the desired optical properties.

[0055] To adjust the transmission properties of glass, MnO ２ , Cr ２ O ３ , V ２ O ５ Each of these components may be included in an appropriate amount. In this case, the content of each component is preferably, for example, 0.05% or more. On the other hand, if the content of the above components is too high, it becomes easier to color the material, and although the transmittance in the visible range decreases, the transmittance in the infrared range also decreases, making it difficult to obtain the desired optical properties. For this reason, the content of each component is preferably, for example, 5% or less.

[0056] To adjust the transmission properties of glass, MnO ２ Fe ２ O ３ , Cr ２ O ３ NiO, Co ３ O ４ , V ２ O ５ , CEO ２ It is preferable to include at least one of the group consisting of the following:

[0057] Pt is a component that can be mixed into glass in the form of ions, colloids, or metals, and it causes yellow to brownish-red coloration. It is also a component that can be involved in the phase separation of glass. The Pt content is preferably 0.05% or less, 0.001% or less, 0.0005% or less, 0.0001% or less, 0.00005% or less, 0.00001% or less, and especially preferably 0.000005% or less. If the Pt content is too high, devitrification containing Pt will precipitate, which tends to increase the manufacturing burden. There is no particular lower limit to the Pt content, and it may be 0%, but when using general melting equipment, it may be necessary to use Pt components to obtain homogeneous glass. For this reason, if you try to completely remove Pt, the manufacturing cost tends to increase. When it does not adversely affect the desired optical properties, the lower limit of the Pt content is preferably greater than 0%, 0.0000001%, and particularly 0.0000005%, in order to suppress an increase in manufacturing costs.

[0058] Rh is a component that can be mixed into glass in the form of ions, colloids, or metals, and it causes yellow to brownish-red coloration. It is also a component that can be involved in the phase separation of glass. The Rh content is preferably 0.05% or less, 0.001% or less, 0.0005% or less, 0.0001% or less, 0.00005% or less, 0.00001% or less, and especially preferably 0.000005% or less. If the Rh content is too high, devitrification containing Rh will precipitate, which tends to increase the manufacturing burden. Transmittance in the visible range tends to be low, but transmittance in the infrared range also tends to be low, making it difficult to obtain the desired optical properties. There is no particular lower limit to the Rh content, and it may be 0%, but when using general melting equipment, it may be necessary to use Rh components to obtain homogeneous glass. For this reason, if you try to remove Rh completely, the manufacturing cost tends to increase. When it does not adversely affect the desired optical properties, the lower limit of the Rh content is preferably greater than 0%, 0.0000001%, and particularly 0.0000005%, in order to suppress an increase in manufacturing costs.

[0059] The glass of the present invention may further contain, in addition to the above components, SO, only if it is possible to obtain the desired chemical durability, transmittance, heat resistance, and thermal shock resistance of the glass. ３, Cl ２ La ２ O ３ Ta ２ O ５ Nb ２ O ５ , RfO ２ The total amount of these components may be up to 10%. However, since the raw material batches of the above components are expensive and tend to increase manufacturing costs, they do not need to be added unless there are special circumstances. The total amount of these components is preferably 5% or less by mass, 4% or less, 3% or less, 2% or less, 1% or less, 0.5% or less, 0.4% or less, 0.3% or less, 0.2% or less, 0.1% or less, 0.05% or less, less than 0.05%, 0.049% or less, 0.048% or less, 0.047% or less, 0.046% or less, and especially preferably 0.045% or less.

[0060] The glass of the present invention may further contain, in addition to the above-mentioned components, for example, H, only if it is possible to obtain the desired chemical durability, transmittance, heat resistance, and thermal shock resistance of the glass. ２ CO ２ CO, H ２ O, He, Ne, Ar, N ２ Trace components such as these may be included in amounts up to 0.1% each. Furthermore, intentionally adding Ag, Au, Pd, Ir, Sc, Ce, Pr, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ac, Th, Pa, U, etc. increases raw material costs and consequently increases manufacturing costs. However, Pd and others have various catalytic effects, and including them makes it possible to impart unique functions to the glass. In light of these circumstances, when the purpose is to promote crystallization or to impart other functions, the above components may be included in amounts of 1% or less, 0.5% or less, 0.3% or less, and 0.1% or less, respectively, and when there is no particular purpose for this, it is preferable that the amounts be 500 ppm or less, 300 ppm or less, 100 ppm or less, and especially 10 ppm or less.

[0061] The glass of the present invention may also be crystallized glass. In this case, the content range of each component is the same as described above. Examples of crystal species in crystallized glass include TiO ２ (Rutile type, anatase type), Al ２ TiO５ Al ４ B ２ O ９ Ti ３ CuO ７ ,Cd,Cd ２ Examples include O, CuO, etc.

[0062] A preferred composition range for implementing the glass of the present invention is, for example, SiO2 by mass. ２ 45-80%, Al ２ O ３ 1-30%, B ２ O ３ The composition is 0-20% for the gas and 0.1-20% for CuO.

[0063] A more preferred composition range is, for example, SiO in mass%. ２ 45-80%, Al ２ O ３ 1-30%, B ２ O ３ 0-20%, CuO 0.1-20%, TiO ２ The percentage is between 0.1% and 20%.

[0064] A more preferred composition range is, for example, SiO in mass%. ２ 45-80%, Al ２ O ３ 1-30%, B ２ O ３ More than 0 to 20%, CuO 1 to 20%, TiO ２ The percentage is between 0.1% and 20%.

[0065] A more preferred composition range is, for example, SiO in mass%. ２ 45-80%, Al ２ O ３ 1-30%, B ２ O ３ 0-20%, CuO 0.1-20%, Li ２ The oxygen content is less than 2%, and the BaO content is less than 1%.

[0066] A more preferred composition range is, for example, SiO in mass%. ２ 45-80%, Al ２ O ３ 1-30%, B ２ O ３0-20%, CuO 0.1-20%, TiO ２ The content is 0.1-20%, with BaO content being less than 1%.

[0067] A more preferred composition range is, for example, SiO in mass%. ２ 45-80%, Al ２ O ３ 1-30%, B ２ O ３ 0-20%, CuO 0.1-20%, TiO ２ The content ranges from 0.1% to 20%, with BaO content being less than 1% and ZnO content being less than 2%.

[0068] The glass of the present invention having the above composition makes it easier to achieve glass with a low coefficient of linear thermal expansion, low transmittance in the visible region, and high transmittance in the infrared region. Furthermore, it makes it easier to achieve glass that also has antibacterial, antiviral, deodorizing, and antifouling properties.

[0069] Furthermore, even when the glass of the present invention is crystallized glass, having the above composition makes it easier to achieve glass with a low coefficient of linear thermal expansion, low transmittance in the visible region, and high transmittance in the infrared region. In addition, it becomes easier to achieve crystallized glass that also has antibacterial, antiviral, deodorizing, and antifouling properties.

[0070] The glass of the present invention has a density of 2.20 to 3.50 g / cm³. ３ , 2.40~3.35g / cm ３ , especially 2.40-3.00 g / cm³ ３ It is preferable that the density is such that if it is too low, the gas permeability of the glass increases, and there is a risk of the glass becoming contaminated during long-term storage. On the other hand, if the density is too high, the weight per unit area increases, making it difficult to handle.

[0071] The glass of the present invention has a linear thermal expansion coefficient of 60 × 10 at 30 to 380°C. －７ / ℃ or below, 56 x 10 －７ / ℃ or below, 50 x 10 －７ / ℃ or below, 48 x 10 －７ / ℃ or below, 44 x 10 －７ / ℃ or below, 40 x 10 －７ / ℃ or below, 36 x 10 －７ / ℃ or below, 34 x 10 －７ / ℃ or below, 32 x 10 －７ / ℃ or below, 29.5 × 10 －７ / ℃ or below, 27.5 × 10 －７ / ℃ or below, 25.5 × 10 －７ / ℃ or lower, especially 23.5 × 10 －７ It is preferable that the temperature is below / ℃.

[0072] Furthermore, the glass of the present invention has a linear thermal expansion coefficient of 60 × 10 at 30 to 500°C. －７ / ℃ or below, 56 x 10 －７ / ℃ or below, 50 x 10 －７ / ℃ or below, 48 x 10 －７ / ℃ or below, 44 x 10 －７ / ℃ or below, 40 x 10 －７ / ℃ or below, 36 x 10 －７ / ℃ or below, 34 x 10 －７ / ℃ or below, 32 x 10 －７ / ℃ or below, 29.5 × 10 －７ / ℃ or below, 27.5 × 10 －７ / ℃ or below, 25.5 × 10 －７ / ℃ or lower, especially 23.5 × 10 －７ It is preferable that the temperature is below / ℃.

[0073] If the linear thermal expansion coefficient is too high, the heat resistance and thermal shock resistance will be low, making it difficult to use at high temperatures. Furthermore, it will be difficult to apply to applications requiring positional stability. In particular, when intended for use as a cooking top plate, a lower linear thermal expansion coefficient is preferable to avoid damage due to heat and distortion. While there is no specific lower limit for the linear thermal expansion coefficient, in practice, the linear thermal expansion coefficient between 30 and 380°C is -70 × 10⁻⁶. －７ The coefficient of linear thermal expansion above 1 / °C, between 30 and 500°C, is -60 × 10⁻¹⁰. －７ It is above / ℃.

[0074] In the glass of the present invention, the temperature at which the slope of the thermal expansion curve of the glass changes is treated as the glass transition point (glass transition temperature). The glass of the present invention preferably has a glass transition point of 500°C or higher, 550°C or higher, 600°C or higher, and particularly 630°C or higher. If the glass transition point is too low, the glass flows too much, making it difficult to mold into the desired shape. Furthermore, if the glass transition point is too low, the glass becomes prone to deformation when used at high temperatures.

[0075] In the glass of the present invention, the temperature at which the slope of the thermal expansion curve of the glass changes above the glass transition temperature is treated as the inflection point. The glass of the present invention preferably has an inflection point of 500°C or higher, 600°C or higher, 650°C or higher, and particularly 700°C or higher. If the inflection point is too low, the glass will flow too much, making it difficult to mold into the desired shape. Furthermore, if the inflection point is too low, the glass will be prone to deformation when used at high temperatures.

[0076] The liquidus temperature of the glass of the present invention is preferably 1600°C or lower, 1540°C or lower, 1480°C or lower, 1380°C or lower, and particularly preferably 1300°C or lower. If the liquidus temperature is too high, devitrification is likely to occur during manufacturing. On the other hand, if the temperature is 1480°C or lower, manufacturing by the roll method or similar becomes easier; if it is 1410°C or lower, manufacturing by the overflow method or similar becomes easier; if it is 1350°C or lower, manufacturing by the bushing method or similar becomes easier; and if it is 1300°C or lower, manufacturing by the Danner method or similar becomes easier.

[0077] The glass of the present invention preferably has a liquid-phase viscosity (logarithm of viscosity corresponding to liquid-phase temperature) of 2.50 or higher, 3.00 or higher, 3.40 or higher, 3.65 or higher, and particularly 3.70 or higher. If the liquid-phase viscosity is too low, devitrification is likely to occur during manufacturing. On the other hand, if it is 3.40 or higher, manufacturing by the roll method, etc. becomes easier; if it is 3.50 or higher, manufacturing by the slip casting method, etc. becomes easier; and if it is 3.70 or higher, manufacturing by the overflow method, etc. becomes easier.

[0078] The glass of the present invention has a viscosity of about 10 ４The temperature corresponding to dPa·s is preferably 1400°C or lower, 1380°C or lower, or 1370°C or lower, and more preferably 1360°C or lower. Also, the viscosity is about 10 ３．５ The temperature corresponding to dPa·s is preferably 1500°C or lower, 1480°C or lower, or 1460°C or lower, and more preferably 1445°C or lower. Also, the viscosity of the glass is about 10 ２．５ The temperature corresponding to dPa·s is preferably 1600°C or lower, 1570°C or lower, or 1560°C or lower, and more preferably 1550°C or lower. Also, the viscosity of the glass is about 10 ２ The temperature corresponding to dPa·s is preferably 1730°C or lower, 1700°C or lower, or 1670°C or lower, and more preferably 1650°C or lower. If the above temperature is too high, the meltability of the glass decreases and it becomes difficult to clarify, which tends to reduce productivity. Furthermore, it tends to put more stress on the molded member, which also tends to reduce productivity.

[0079] The glass of the present invention preferably has a thickness of 4 mm and a transmittance of 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 75% or more, 80% or more, and particularly 82% or more at a wavelength of 1500 nm. This makes it easier to improve the accuracy of temperature detection using infrared rays, especially in top plate applications. It is also preferable that the values ​​are within the above range when used in infrared communication applications such as infrared cameras and remote controls.

[0080] Brightness L of the glass of the present invention ＊ This is a 4mm thick, L-grade light. ＊ It is preferable that the percentage is 60% or less, 45% or less, 40% or less, 35% or less, 30% or less, 25% or less, 20% or less, 15% or less, and especially 10% or less. This can enhance the jet blackness of the resulting glass. Therefore, it is preferable that the percentage is within the above range, especially when a black appearance is required for top plates, etc., or when used in chemical containers or visible light shielding applications.

[0081] The glass of the present invention may be subjected to physical strengthening by air cooling, water cooling, etc., or chemical strengthening. When compressive stress is applied to the glass of the present invention by air cooling strengthening, chemical strengthening, etc., it is preferable that the compressive stress value (CS) is 50 MPa or more, 150 MPa or more, 230 MPa or more, and particularly 300 MPa or more. If the compressive stress value is too low, the Vickers hardness and bending strength may be low. Furthermore, it is preferable that the compressive stress depth (DOC) is 10 μm or more, 100 μm or more, and particularly 120 μm or more. If the compressive stress depth is too low, the fracture strength may be low. The compressive stress value (CS) and compressive stress depth (DOC) can be measured using a scattered light photoelastic stress meter SLP-1000 (manufactured by Orihara Manufacturing Co., Ltd.) and a surface stress meter FSM-6000 (manufactured by Orihara Manufacturing Co., Ltd.).

[0082] Furthermore, it is preferable that the glass of the present invention, when it is crystallized glass, has the same properties as described above.

[0083] The shape of the glass in this invention is usually plate-like (especially flat), but is not limited to this, and can be appropriately selected depending on the application.

[0084] Next, the method for manufacturing the glass of the present invention will be described.

[0085] The present invention provides a method for manufacturing glass, comprising the steps of melting glass raw materials to obtain molten glass and shaping the molten glass.

[0086] Specifically, first, a batch of raw materials (glass raw materials) prepared to produce glass of the above composition is placed in a glass melting furnace and melted at 1200 to 1800°C to obtain molten glass, which is then molded. When melting the glass, one or more of the following melting methods may be used: flame melting using a burner, electric melting using electric heating, laser irradiation melting, plasma melting, liquid-phase synthesis, and gas-phase synthesis.

[0087] The molding method is preferably at least one selected from the overflow method, float method, downdraw method, slot-down method, redraw method, containerless method, blow method, press method, roll method, bushing method, and tubing method. Furthermore, the molded glass may be reheated at a temperature above the glass transition temperature. In this way, the glass of the present invention with good surface quality can be manufactured.

[0088] Next, the obtained glass is annealed. The main purpose of annealing is to remove strain and residual stress. In this case, it is preferable to heat treat the glass by keeping it in the temperature range of room temperature to the strain point (≈glass transition point -5 to -20°C) for at least 1 minute, more preferably 3 minutes, 16 minutes, and most preferably more than 30 minutes.

[0089] Next, the glass of the present invention is cooled. The cooling rate when cooling the glass of the present invention after annealing may be a specific temperature gradient or a temperature gradient of two or more levels. If sufficient thermal shock resistance is to be obtained, it is desirable to control the cooling rate to sufficiently relax the structure of the remaining glass phase. In that case, the average cooling rate from the highest annealing temperature to 25°C is preferably 3000°C / min, 1000°C / min or less, 500°C / min or less, 200°C / min or less, 50°C / min or less, 10°C / min or less, and especially 5°C / min or less in the part of the glass interior furthest from the surface of the glass of the present invention. Furthermore, if dimensional stability over a long period of time is to be obtained, it is even more preferable to have a cooling rate of 2.5°C / min or less, 0.1°C / min or less, 0.05°C / min or less, and especially 0.01°C / min or less. Except when physical strengthening treatment is performed by air cooling, water cooling, etc., it is desirable that the cooling rate of the glass surface is close to the cooling rate of the interior of the glass thickness furthest from the glass surface. The value obtained by dividing the cooling rate in the part of the glass furthest from the surface by the cooling rate of the surface is preferably 0.0001 to 1, 0.01 to 1, 0.1 to 1, 0.8 to 1, and especially 1. A value close to 1 makes it less likely for residual strain to occur at all positions in the glass of the present invention, making it easier to obtain long-term dimensional stability. The cooling rate of the surface can be estimated using a contact thermometer or a radiation thermometer. The temperature inside the glass can be estimated from numerical data obtained by immersing the high-temperature glass in a cooling medium and measuring the heat quantity and heat quantity change rate of the cooling medium, as well as from the specific heat and thermal conductivity of the glass and the cooling medium.

[0090] As described above, the glass of the present invention can be obtained. The glass of the present invention can be used, for example, as a heat-resistant material or as a material for cooktop top plates.

[0091] Furthermore, the process may include a crystallization step in which the obtained glass is subjected to heat treatment. This makes it possible to obtain the crystallized glass of the present invention.

[0092] For example, crystallized glass can be obtained by heat-treating annealed glass to induce crystallization. The crystallization conditions are as follows: First, nucleation is performed at 700°C to 1200°C (preferably 750°C to 900°C) for 0.1 to 60 hours (preferably 0.25 to 50 hours, more preferably 1 to 40 hours), followed by crystal growth at 800 to 1300°C (preferably 850 to 1100°C) for 0.1 to 50 hours (preferably 0.2 to 10 hours, more preferably 0.25 to 5 hours). Note that the heat treatment in each step of nucleation and crystal growth may be performed at a specific temperature only, or the heat treatment may be performed in stages by maintaining two or more temperature levels, or heating may be performed while applying a temperature gradient. Alternatively, only the heat treatment for crystal growth may be performed without nucleation.

[0093] Furthermore, for example, when manufacturing crystallized glass for use as a top plate, the glass of the present invention can be crystallized simultaneously with the baking process, in which a printed layer is baked onto the glass surface.

[0094] Furthermore, crystals may be precipitated by annealing, or crystallization may be promoted by applying or irradiating with sound waves or electromagnetic waves. In addition, the cooling rate when cooling the crystallized glass of the present invention, which has been heated to a high temperature, may be a specific temperature gradient, or it may be a temperature gradient with two or more levels. It is desirable that the cooling rate be the same as the cooling rate of the glass described above.

[0095] Furthermore, the process may include a strengthening step in which the obtained glass is subjected to physical or chemical strengthening by air cooling, water cooling, etc. Note that physical strengthening by air cooling can be performed simultaneously with the cooling after annealing, and can also be performed simultaneously with the cooling after crystal growth in the crystallization process. Moreover, for example, when manufacturing crystallized glass for top plate applications, it can be performed simultaneously with the cooling after the baking process in which a printed layer is baked onto the glass surface.

[0096] The resulting glass of the present invention may be cut. For example, when cutting with a wire saw, it is preferable to cut while supplying a slurry containing abrasive particles to the wire saw.

[0097] The present invention will now be described based on examples, but the present invention is not limited to the following examples. Tables 1 to 82 show the composition and characteristic values ​​of the glass (samples No. 1 to 201) according to the examples of the present invention.

[0098]

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[0180] First, glass batches were obtained by mixing each raw material in the form of oxides, hydroxides, carbonates, nitrates, etc., to produce glass having the composition described in each table (the compositions described in each table are analytical values ​​of the glass actually produced. The analysis was performed using a RIGAKU ZSX series scanning X-ray fluorescence analyzer). The obtained glass batches were melted at 1200 to 1800°C for 0.5 to 400 hours, and the resulting molten glass was rolled using the roll method while cooling to form a glass with a width of 100 mm and a thickness of 5 mm. After that, the glass was heat-treated in an annealing furnace at the glass transition temperature + 30°C for 30 minutes, and the annealing furnace was cooled to room temperature at -100°C / h to obtain glasses No. 1 to 201.

[0181] The prepared glass samples were processed by physical polishing, chemical polishing, chemical etching, fire blasting, etc., to create samples for evaluation of viscosity, liquidus temperature, liquidus viscosity, density, linear thermal expansion coefficient, etc., and then evaluated.

[0182] The Pt and Rh content of the prepared samples was analyzed using an ICP-MS instrument (Agilent 8800, manufactured by AGILEINT TECHNOLOGY) as follows. First, the prepared glass samples were crushed and wetted with pure water, and then dissolved by adding perchloric acid, nitric acid, sulfuric acid, hydrofluoric acid, etc. Afterward, the Pt and Rh content of the samples was measured by ICP-MS (inductively coupled plasma mass spectrometry). The Pt and Rh content of each sample was determined based on a calibration curve created using pre-prepared Pt and Rh solutions of known concentrations. The measurement modes were Pt: He gas / HMI (low mode) and Rh: HEHe gas / HMI (medium mode), with mass numbers of Pt: 198 and Rh: 103. Furthermore, the Li content of the prepared samples was also analyzed. ２ The O content was analyzed using an atomic absorption spectrometer (Analytic Jena ContrAA600). The procedure for melting the glass sample and the use of calibration curves were basically the same as for Pt and Rh analysis. Regarding other components, Pt, Rh, and Li... ２ Similar to O, the concentration was measured by ICP-MS or atomic absorption spectrometry. Alternatively, glass samples with known concentrations, which had been previously analyzed using ICP-MS or atomic absorption spectrometry, were used as calibration samples. A calibration curve was then created using an XRF (X-ray fluorescence) analyzer (RIGAKU ZSX Primus IV), and the actual content of each component was determined from the XRF analysis values ​​of the measured sample based on this calibration curve. During XRF analysis, the tube voltage, tube current, exposure time, etc., were adjusted as needed according to the analytical component.

[0183] Density was evaluated using the Archimedes method.

[0184] The linear thermal expansion coefficient was evaluated using the average linear thermal expansion coefficient measured at temperatures of 30–380°C and 30–500°C with a sample processed to 20 mm × 3.8 mmφ. A NETZSCH Dilatometer was used for the measurements. In addition, the thermal expansion curve of the glass sample in the temperature range of 30–500°C was measured using the same instrument, and the glass transition point and flexure point were evaluated by calculating the inflection point.

[0185] The liquidus temperature was evaluated using the following method. First, glass powder, uniformly sized to 300-500 micrometers, was packed into a platinum boat measuring approximately 120 x 20 x 10 mm and placed in an electric furnace where it was melted at 1400-1800°C for 30 minutes. Subsequently, the platinum boat was transferred to an electric furnace with a linear temperature gradient and held for 20 hours to allow devitrification to precipitate. After the sample was air-cooled to room temperature, the devitrification precipitated at the interface between the platinum boat and the glass was observed, and the temperature of the devitrification precipitate was calculated from the electric furnace's temperature gradient graph to determine the liquidus temperature. Furthermore, the viscosity corresponding to the liquidus temperature was evaluated as the liquidus viscosity by interpolating the obtained liquidus temperature onto the high-temperature viscosity curve of the glass.

[0186] High-temperature viscosity was evaluated using the platinum ball pulling method as follows: A block of glass sample was crushed to the appropriate dimensions and placed in an alumina crucible. The alumina crucible was then heated to melt the sample, and the viscosity of the glass at multiple temperatures was measured. The constants of the Vogel-Fulcher equation were calculated to create viscosity curves, and the viscosity at each temperature (10 ４ dPa·s, 10 ３．５ dPa·s, 10 ３ dPa·s, 10 ２．５ dPa·s and 10 ２ The temperature at dPa·s was calculated.

[0187] Transmittance and brightness L at a wavelength of 1500 nm ＊The values ​​were evaluated using a 4 mm thick sample with a surface roughness equivalent to optical polishing, employing a spectrophotometer. A JASCO V-670 spectrophotometer was used. The V-670 was equipped with the ISN-723 integrating sphere unit, and the measured transmittance corresponds to the total light transmittance. The measurement wavelength range was 200–2500 nm, the scan speed was 200 nm / min, the sampling pitch was 1 nm, and the bandwidth was 5 nm in the 200–800 nm wavelength range and 20 nm in other wavelength ranges. Before measurement, baseline correction (100% adjustment) and dark measurement (0% adjustment) were performed. Dark measurement was performed with the barium sulfate plate attached to the ISN-723 removed. From the measured transmittance, the transmittance at a wavelength of 1500 nm was read. Using the measured transmittance, the tristimulus values ​​XYZ were calculated based on JIS Z 8781-42013 and its corresponding international standards, and the lightness L was calculated from each stimulus value. ＊ The value was calculated (light source C / 10°).

[0188] The antibacterial properties were evaluated as follows. Based on the method of JIS Z 2801 (Antibacterial processed products - Antibacterial test method and antibacterial effect), two bacterial species, Staphylococcus aureus and Escherichia coli, were applied to test pieces made from glass according to Examples No. 40, 82, and 168, as well as to standard glass pieces. The samples were incubated for 24 hours at 35°C and a relative humidity of 90% or higher, and the number of viable bacteria was measured. The antibacterial activity value ((logarithm of the number of viable bacteria on the surface of the standard glass piece after 24 hours) - (logarithm of the number of viable bacteria on the surface of the prepared test piece after 24 hours)) was calculated. An antibacterial effect was evaluated when the antibacterial activity value obtained by the above test was 2.0 or higher. Table 83 shows the measurement results of the antibacterial activity value.

[0189]

[0190] The antiviral activity was evaluated as follows. An antiviral performance evaluation test using bacteriophages was conducted based on JIS R 1706:2020 (UV light-responsive photocatalyst, antiviral, film contact method). First, 0.15 ml of Qβ bacteriophage solution was dropped onto a glass piece (50 mm × 50 mm × 4 mm thick) of Example No. 168 before and after crystallization. After covering this glass piece with a polypropylene film, it was left at room temperature in the dark for 24 hours, and the bacteriophage solution was collected. After diluting the collected bacteriophage solution, plaques were measured on an agar plate, and the antiviral activity value ((logarithm of infectivity titer after 24 hours) - (logarithm of infectivity titer at 0 hours)) was calculated. An antiviral effect was evaluated when the antiviral activity value obtained by the above test was 2.0 or higher. The antiviral effect was similarly evaluated using φ6 bacteriophage solution. Table 84 shows the measurement results of the antiviral activity value.

[0191]

[0192] The deodorizing properties were evaluated as follows. A deodorizing test was conducted in reference to the Japan Textile Evaluation Technology Council (JEC) standard JEC301-2025. First, as a sample test, glass from Example No. 168 was crushed in an agate mortar and classified using a sieve with a mesh size of 200 μm to produce 20 μm glass powder with a D50 grade. Next, 5 g of the above glass powder was placed in a plastic petri dish and then placed into a 5 L sampling bag. After degassing the sampling bag with a vacuum pump, 3 L of hydrogen sulfide gas with a concentration of 4 ppm was injected, and the gas concentration after standing for 24 hours was measured using a gas detection tube. As a blank test, 3 L of hydrogen sulfide gas with a concentration of 4 ppm was injected into an empty sampling bag, and the gas concentration after standing for 24 hours was measured using a gas detection tube. The odor reduction rate was calculated from the gas concentrations measured in the sample test and the blank test using the following formula [Equation 1]. A deodorizing effect was evaluated when the odor reduction rate obtained by the above test was 70% or more. Similar tests were also conducted using methyl mercaptan gas at a concentration of 8 ppm, ammonia gas at a concentration of 100 ppm, and trimethylamine gas at a concentration of 28 ppm as odor-causing substances. Table 85 shows the results of the odor reduction rate measurement.

[0193] [Formula 1] Odor reduction rate (%) = ((S ｂ -S ｍ ) / S ｂ ) × 100 S ｂ : Gas concentration (ppm) in the blank test S ｍ : Gas concentration (ppm) of the sample test

[0194]

[0195] The stain resistance was evaluated as follows. First, commercially available yakiniku sauce was evenly applied to the surface of a glass piece (50 mm x 50 mm x 4 mm thick) of Example No. 168 before and after crystallization, and heated in an electric furnace at 250°C for 30 minutes to char it. Next, the glass piece was removed from the electric furnace and allowed to cool naturally, then immersed in cold water for 5 minutes. After that, the charred residue adhering to the surface of the removed glass piece was lightly scraped off using chopsticks with flat tips. If no remaining charred residue could be visually confirmed after the above test, the material was evaluated as having stain resistance. The results of the stain resistance test are shown in Table 86.

[0196]

[0197] The glasses of Examples No. 1 to 201 of the present invention have a low coefficient of linear thermal expansion, L ＊Due to the low value, the transmittance in the visible region was low, and the transmittance in the infrared region (wavelength 1500 nm) was also high. Furthermore, when antibacterial tests were conducted on Examples No. 40, 82, and 168, the antibacterial activity values ​​against Staphylococcus aureus and Escherichia coli were all 2.0 or higher, indicating that they have an antibacterial effect. Furthermore, when antiviral tests were conducted on Example No. 168, the antiviral activity value against φ6 bacteriophage was 2.0 or higher, indicating that it has an antiviral effect against φ6 bacteriophage. Furthermore, when crystallized Example No. 168 was also tested for antiviral activity, the antiviral activity value against Qβ bacteriophage was 2.0 or higher, indicating that it has an antiviral effect against Qβ bacteriophage. Furthermore, Example No. In a deodorizing test conducted on example No. 168, it was found that the odor reduction rate for each odorous substance—hydrogen sulfide gas, methyl mercaptan gas, ammonia gas, and trimethylamine gas—was 70% or more, indicating that it possesses deodorizing properties. Furthermore, in a stain-resistant test conducted on example No. 168, it was found that there was no burnt residue on the glass before and after crystallization, indicating that it possesses stain-resistant properties.

[0198] The glass of the present invention is suitable for applications such as cooktop top plates, fireproof windows, heat-resistant tableware, building components, front windows for oil stoves and wood-burning stoves, setters for firing electronic components, furnace tubes for semiconductor manufacturing, dimensional measuring components, communication components, chemical reaction vessels, heat-resistant covers, components for astronomical telescopes, and linear thermal expansion coefficient adjustment materials. Furthermore, when the glass of the present invention is crystallized glass, it is preferably used for cooktop top plates, fireproof windows, heat-resistant tableware, or building components. The applications of the glass with a low linear thermal expansion coefficient of the present invention are not limited to those described above. It may also be used in the above applications alone or in combination with other applications.

Claims

1. By mass%, SiO ２ 45-80%, Al ２ O ３ 1-30%, B ２ O ３ A glass characterized by containing 0-20% and 0.1-20% CuO.

2. TiO ２ The glass according to claim 1, characterized by containing 0.1 to 20%.

3. TiO ２ The glass according to claim 2, characterized in that the CuO content is in the range of greater than 0 to 17.

4. In mass %, B ２ O ３ is more than 0% and the glass according to claim 2 contains 1% or more of CuO.

5. The glass according to claim 1, characterized in that the BaO content is less than 1% by mass.

6. The glass according to claim 1, characterized in that the ZnO content is less than 2% by mass.

7. As a coloring component, MnO ２ Fe ２ O ３ , Cr ２ O ３ NiO, Co ３ O ４ , V ２ O ５ , CEO ２ The glass according to claim 1, characterized in that it contains at least one from the group consisting of the following.

8. The glass according to claim 1, characterized in that it contains more than 0% MgO by mass.

9. In mass%, P ２ O ５ The glass according to claim 1, characterized in that it contains more than 0% of [the specified substance].

10. The coefficient of linear thermal expansion between 30 and 500°C is 50 × 10⁻⁶. －７ The glass according to claim 1, characterized in that it is below / ℃.

11. L at a thickness of 4 mm ＊ The glass according to claim 1, characterized in that the value is 30% or less.

12. The glass according to claim 1, characterized in that the transmittance at a wavelength of 1500 nm at a thickness of 4 mm is 60% or more.

13. The glass according to claim 1, characterized in that its glass transition temperature is 600°C or higher.

14. By mass%, CuO 0.1-20%, TiO ２ It contains 0.1-20% and has a linear thermal expansion coefficient of 50 × 10 at 30-500°C. －７ Glass characterized by having a temperature of / ℃ or lower.

15. By mass%, CuO 0.1-20%, TiO ２ It contains 0.1-20%, and L in a thickness of 4 mm ＊ Glass characterized by having a value of 30% or less.

16. By mass%, CuO 0.1-20%, TiO ２ A glass characterized by containing 0.1 to 20% of a certain substance and having a transmittance of 60% or more at a wavelength of 1500 nm at a thickness of 4 mm.

17. By mass%, CuO 0.1-20%, TiO ２ A glass characterized by containing 0.1 to 20% of a certain substance and having a glass transition temperature of 600°C or higher.

18. The glass according to any one of claims 1 to 17, characterized in that it is a crystallized glass.

19. A heat-resistant material characterized by comprising the glass of claim 18.

20. A top plate for a cooking appliance, characterized by comprising the glass of claim 18.

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