Near-infrared absorbing glass and near-infrared cut filters

Abstract

To provide a near-infrared absorbing glass that has a high transmittance in a visible spectrum (violet-red regions) even when subjected to a thinning process, boasts a near-infrared radiation cutting performance, and shows little decrease in weather resistance.SOLUTION: The present invention provides a near-infrared absorbing glass which contains at least four kinds of main cations that are selected from a group consisting of P ions, Li ions, Cu ions, Al ions, Ba ions, Sr ions, Ca ions, Mg ions, Zn ions, K ions, Na ions, La ions, Gd ions and Y ions, while containing P ions, Ba ions and Cu ions as essential cations, wherein: in a glass composition expressed in terms of anion percentage, the content of O ions is 90.0 anion% or more; in a glass composition expressed in terms of atomic percentage, the ratio ((O ions) / (P ions)) of the content of O ions to the content of P ions is 3.15 or less; and in a glass composition expressed in terms of molar percentage based on oxides, the total content (B2O3+SiO2) of B2O3 and SiO2 is 3.0 mol% or less, the total content (MgO+Al2O3) of MgO and Al2O3 is 8.0 mol% or less, the total content (Li2O+Na2O+K2O) of Li2O, Na2O and K2O is 15 mol% or less, and the content of CuO is α1% or more. Meanwhile, α1 is a value calculated by equation 1: α1=70400×exp(-2.855×R) (where R represents the above-described ratio ((O ions) / (P ions))).SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to near-infrared absorbing glass and near-infrared cut filters. [Background technology]

[0002] In recent years, small cameras, such as those found in smartphones, not only is the acquired image information simply digitized, but the image is also reconstructed by performing various computer processing operations on that image information. For example, it has become common practice to extract a specific object and adjust the color and contrast of the image. In this process, if color information that does not originally exist is input to the image sensor due to light reflection in the optical element, that information must be removed, which is undesirable.

[0003] A near-infrared cut filter has the function of cutting out unwanted near-infrared light (wavelength 700-1200 nm) within the sensitivity wavelength range of the image sensor. Near-infrared cut filters are generally installed directly in front of the image sensor.

[0004] Near-infrared cut filters widely used are those made from near-infrared absorbing glass, which is polished onto a flat plate.

[0005] Near-infrared absorbing glass generally contains Cu ions. An example of the spectral transmission characteristics of near-infrared absorbing glass is shown in Figure 1. Note that Figure 1 does not limit the present invention in any way. The light absorption characteristics around wavelengths of 700 to 1200 nm are due to the Cu ions in the glass (Cu 2+ It is manifested by ). In particular, glass containing P ions along with Cu ions is characterized by Cu ions (Cu 2+ Because it can exhibit near-infrared absorption characteristics over a wide wavelength range, it is useful as glass for near-infrared cut filters (see, for example, Patent Documents 1-3). [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2019-38719 [Patent Document 2] CN110255897 [Patent Document 3] Japanese Patent Application Publication No. 55-3336 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] In the transmittance curve for wavelengths above 600 nm shown in Figure 1, the wavelength at which the transmittance is 50% is called the "half-value" and is one of the main specifications for near-infrared cut filters. The half-value varies depending on the filter specifications, but it is often set in the wavelength range of 600 nm to 650 nm. A common method for setting the half-value to the desired value is to adjust the thickness of the glass substrate or the Cu ions in the glass, following the Lambert-Beer law. 2+ There are ways to adjust either the concentration or the concentration.

[0008] Near-infrared cut filters are required to have excellent ability to cut near-infrared light (i.e., have a desired half-value while having low transmittance of near-infrared light), as well as high transmittance in the visible range (purple to red regions).

[0009] Furthermore, in recent years, image sensor modules used in smartphones and other devices are required to be both miniaturized and high-performance, and the thickness of near-infrared cut filters is required to be thinner. As a result, the thickness of near-infrared absorbing glass has been reduced from the conventional 1 mm to around 0.45 mm, 0.3 mm, or 0.2 mm in recent years, and there is even a desire to reduce it to as thin as 0.1 mm.

[0010] Simply thinning near-infrared absorbing glass reduces the optical concentration of CuO (moles × thickness) required for near-infrared absorption, thus lowering the near-infrared absorption efficiency. To solve this, one might consider increasing the amount of CuO. However, simply increasing the amount of CuO tends to decrease the transmittance on the short-wavelength side, making it difficult to maintain both the transmittance in the visible range (purple to red regions) and near-infrared absorption.

[0011] Furthermore, in order to provide a near-infrared absorbing glass suitable for use in high-temperature and high-humidity environments, it is desirable that the deterioration of weather resistance in such environments be suppressed. However, according to the inventors' research, it is not easy to suppress the deterioration of weather resistance while maintaining both the transmittance in the visible range (purple to red regions) and the absorption of near-infrared rays.

[0012] In view of the above, one aspect of the present invention aims to provide a near-infrared absorbing glass that has high transmittance in the visible region (purple region to red region) even when thinned, has excellent near-infrared cutting ability, and can suppress a decrease in weather resistance, and a near-infrared cut filter made of such near-infrared absorbing glass. [Means for solving the problem]

[0013] One aspect of the present invention is, It contains four or more major cations selected from the group consisting of P ions, Li ions, Cu ions, Al ions, Ba ions, Sr ions, Ca ions, Mg ions, Zn ions, K ions, Na ions, La ions, Gd ions, and Y ions. It contains P ions, Ba ions, and Cu ions as essential cations. In the glass composition expressed in anion percentage, the O ion content is 90.0 anion% or more. In the glass composition expressed in atomic percent, the ratio of O ions to P ions (O ions / P ions) (hereinafter also referred to as the "O / P ratio") is 3.15 or less. In glass composition expressed in mol% based on oxides, The total content of B2O3 and SiO2 (B2O3 + SiO2) is 3.0 mol% or less. The total content of MgO and Al2O3 (MgO + Al2O3) is 8.0 mol% or less. The total content of Li2O, Na2O, and K2O (Li2O + Na2O + K2O) is 15 mol% or less. The CuO content is α1% or more. α1 is given by the following equation 1: (Formula 1) α1 = 70400 × exp(-2.855 × R) This is a value calculated by, In formula 1 above, R is the above ratio (O ions / P ions). Near-infrared absorbing glass (hereinafter also referred to as "glass 1"). Regarding.

[0014] Furthermore, one embodiment of the present invention is: It contains four or more major cations selected from the group consisting of P ions, Li ions, Cu ions, Al ions, Ba ions, Sr ions, Ca ions, Mg ions, Zn ions, K ions, Na ions, La ions, Gd ions, and Y ions. It contains P ions, Ba ions, and Cu ions as essential cations. In the glass composition expressed in anion percentage, the O ion content is 90.0 anion% or more. In the glass composition expressed in atomic percent, the ratio of O ions to P ions (O ions / P ions) is 3.15 or less. In glass composition expressed in mol% based on oxides, The total content of B2O3 and SiO2 (B2O3 + SiO2) is 3.0 mol% or less. The total content of MgO and Al2O3 (MgO + Al2O3) is 8.0 mol% or less. The total content of Li2O, Na2O, and K2O (Li2O + Na2O + K2O) is 15 mol% or less. Formula 2 below: (Formula 2) C-3200×exp(-2.278×R)≧0 Satisfying the conditions, In equation 2 above, C represents the CuO content per molar volume of glass (unit: millimoles / cc), R is the above ratio (O ions / P ions). Near-infrared absorbing glass (hereinafter also referred to as "glass 2"). Regarding.

[0015] Furthermore, one embodiment of the present invention is: It contains four or more major cations selected from the group consisting of P ions, Li ions, Cu ions, Al ions, Ba ions, Sr ions, Ca ions, Mg ions, Zn ions, K ions, Na ions, La ions, Gd ions, and Y ions. It contains P ions, Ba ions, and Cu ions as essential cations. In the glass composition expressed in anion percentage, the O ion content is 90.0 anion% or more. In the glass composition expressed in atomic percent, the ratio of O ions to P ions (O ions / P ions) is 3.15 or less. In glass composition expressed in mol% based on oxides, The total content of B2O3 and SiO2 (B2O3 + SiO2) is 3.0 mol% or less. The total content of MgO and Al2O3 (MgO + Al2O3) is 8.0 mol% or less. The total content of Li2O, Na2O, and K2O (Li2O + Na2O + K2O) is 15 mol% or less. Formula 3 below: (Formula 3) A1 = {O(P) - O(others)} × Cu The A1 calculated by this method is 2500 or more, In the above formula 3, O(P) indicates the amount of oxygen that constitutes the oxide of P ions in the oxide-based glass composition. O(others) represents the amount of oxygen obtained by subtracting the above O(P) from the amount of oxygen constituting the oxide of the above major cation in the oxide-based glass composition. Cu represents the CuO content in molar percentage in the oxide-based glass composition. Near-infrared absorbing glass (hereinafter also referred to as "glass 3"). Regarding.

[0016] Furthermore, one embodiment of the present invention is: It contains four or more major cations selected from the group consisting of P ions, Li ions, Cu ions, Al ions, Ba ions, Sr ions, Ca ions, Mg ions, Zn ions, K ions, Na ions, La ions, Gd ions, and Y ions. It contains P ions, Ba ions, and Cu ions as essential cations. In the glass composition expressed in anion percentage, the O ion content is 90.0 anion% or more. In the glass composition expressed in atomic percent, the ratio of O ions to P ions (O ions / P ions) is 3.15 or less. In glass composition expressed in mol% based on oxides, The total content of B2O3 and SiO2 (B2O3 + SiO2) is 3.0 mol% or less. The total content of MgO and Al2O3 (MgO + Al2O3) is 8.0 mol% or less. The total content of Li2O, Na2O, and K2O (Li2O + Na2O + K2O) is 15 mol% or less. Formula 4 below: (Formula 4) A2 = {O(P) - O(others)} × C The A2 calculated by this method is 700 or more. In equation 4 above, C represents the CuO content per molar volume of glass (unit: millimoles / cc), O(P) indicates the amount of oxygen that constitutes the oxide of P ions in the oxide-based glass composition. O(others) represents the amount of oxygen obtained by subtracting O(P) from the amount of oxygen constituting the oxide of the above-mentioned major cation in the oxide-based glass composition. Near-infrared absorbing glass (hereinafter also referred to as "glass 4"). Regarding.

[0017] Furthermore, one embodiment of the present invention is: It contains four or more major cations selected from the group consisting of P ions, Li ions, Cu ions, Al ions, Ba ions, Sr ions, Ca ions, Mg ions, Zn ions, K ions, Na ions, La ions, Gd ions, and Y ions. It contains P ions, Ba ions, and Cu ions as essential cations. In the glass composition expressed in anion percentage, the O ion content is 90.0 anion% or more. In the glass composition expressed in atomic percent, the ratio of O ions to P ions (O ions / P ions) is 3.15 or less. In glass composition expressed in mol% based on oxides, The total content of B2O3 and SiO2 (B2O3 + SiO2) is 3.0 mol% or less. The total content of MgO and Al2O3 (MgO + Al2O3) is 8.0 mol% or less. The total content of Li2O, Na2O, and K2O (Li2O + Na2O + K2O) is 15 mol% or less. The CuO content is α2% or more. α2 is given by the following equation 5: (Formula 5) α² = 76522 × exp(-2.855 × R) This is a value calculated by, In the above formula 5, R is the above ratio (O ions / P ions). Near-infrared absorbing glass (hereinafter also referred to as "glass 5"). Regarding.

[0018] Furthermore, one embodiment of the present invention is: It contains four or more major cations selected from the group consisting of P ions, Li ions, Cu ions, Al ions, Ba ions, Sr ions, Ca ions, Mg ions, Zn ions, K ions, Na ions, La ions, Gd ions, and Y ions. It contains P ions, Ba ions, and Cu ions as essential cations. In the glass composition expressed in anion percentage, the O ion content is 90.0 anion% or more. In the glass composition expressed in atomic percent, the ratio of O ions to P ions (O ions / P ions) is 3.15 or less. In glass composition expressed in mol% based on oxides, The total content of B2O3 and SiO2 (B2O3 + SiO2) is 3.0 mol% or less. The total content of MgO and Al2O3 (MgO + Al2O3) is 8.0 mol% or less. The total content of Li2O, Na2O, and K2O (Li2O + Na2O + K2O) is 15 mol% or less. Formula 6 below: (Formula 6) C - 3478 × exp(-2.278 × R) ≥ 0 Satisfying the conditions, In formula 6 above, C represents the CuO content per molar volume of glass (unit: millimoles / cc), R is the above ratio (O ions / P ions). Near-infrared absorbing glass (hereinafter also referred to as "glass 6"). Regarding.

[0019] Furthermore, one embodiment of the present invention is: In glass composition expressed in mol% based on oxides, P2O5 content is 40.0-65.0 mol%, CuO content is 9.0-25.0 mol%, BaO content is 5.0-50.0 mol%, The total content of Li2O, Na2O, and K2O (Li2O + Na2O + K2O) is 1.0 to 15.0 mol%, SiO2 content is 2.0 mol% or less. B2O3 content is 2.0 mol% or less. Al2O3 content is 0.5 to 7.0 moles %、 Li2O content is 7.0 mol% or less. ZnO content is 10.0 mol% or less. PbO content is 2.0 mol% or less. The ratio of MgO content to the total content of MgO, CaO, SrO, and BaO (MgO / (MgO+CaO+SrO+BaO)) is 0.3 or less. In the glass composition expressed in atomic percent, the ratio of O ions to P ions (O ions / P ions) is 3.50 or less. In glass composition expressed in anion percentage, the F ion content is 10.0 anion% or less. Near-infrared absorbing glass (hereinafter also referred to as "glass 7"). Regarding.

[0020] Furthermore, one embodiment of the present invention is: With a thickness of 0.25 mm or less, and converted to a thickness at which the external transmittance is 50% at wavelengths of 620-650 nm, it has transmittance characteristics such as an external transmittance of 75% or more at wavelengths of 400 nm and an external transmittance of 7% or less at wavelengths of 1200 nm, and The average coefficient of linear expansion at 100-300°C is 135 × 10⁻⁵ -7 Near-infrared absorbing glass with a K level of 0.5 or lower (hereinafter also referred to as "glass 8"). Regarding. [Effects of the Invention]

[0021] According to one aspect of the present invention, it is possible to provide near-infrared absorbing glass that exhibits high transmittance in the visible region (purple to red region) even when thinned, has excellent near-infrared cutting ability, and can suppress the deterioration of weather resistance. Furthermore, according to one aspect of the present invention, it is possible to provide a near-infrared cut filter made of such near-infrared absorbing glass. [Brief explanation of the drawing]

[0022] [Figure 1] An example of the spectral transmission characteristics of near-infrared absorbing glass is shown. [Figure 2] The images show the appearance of the glass in Examples 1-1 to 1-4. [Figure 3]The graphs shown plot the T400 value against the Sb2O3 content for the glasses of Example 1 and Examples 1-1 to 1-4. [Figure 4] The images show the appearance of the glass in Examples 4-1 to 4-4. [Figure 5] The graphs shown plot the T400 value against the Sb2O3 content for the glasses of Example 4 and Examples 4-1 to 4-4. [Figure 6] The images show the appearance of the glass in Examples 25-1 to 25-4. [Figure 7] The graphs shown plot the T400 value against the Sb2O3 content for the glasses of Example 25 and Examples 25-1 to 25-4. [Modes for carrying out the invention]

[0023] [Near-infrared absorbing glass] In the following, Glass 1-8 will be collectively referred to simply as "glass" or "near-infrared absorbing glass." Unless otherwise specified, the descriptions of glass composition and physical properties apply to all of Glass 1-8.

[0024] In the present invention and this specification, near-infrared absorbing glass is glass that has the property of absorbing light of all or part of the wavelength range of at least the near-infrared wavelength range (wavelength 700 to 1200 nm). Furthermore, since the near-infrared absorbing glass according to one aspect of the present invention may contain O ions as constituent ions, it can be an oxide glass. Oxide glass is glass in which the main network-forming component of the glass is an oxide. Moreover, since the near-infrared absorbing glass according to one aspect of the present invention may contain P ions (cations) along with O ions (anions) as constituent ions, it can be a phosphate glass. Note that the O ion is an anion of the oxygen atom and is generally also called an oxide ion.

[0025] The following provides a more detailed explanation of glass types 1 through 8.

[0026] <Glass composition> (Analysis method) For various components constituting the glass, the content (mass % of the element) of the elements contained in the glass can be quantified by known methods, such as inductively coupled plasma atomic emission spectrometry (ICP-AES), inductively coupled plasma mass spectrometry (ICP-MS), etc. For the anion component, the anion component contained in the glass can be identified and quantified by known analytical methods, such as ion chromatography, non-dispersive infrared absorption method (ND-IR), etc. In the present invention and this specification, when the content of a constituent component is 0% or not contained or not introduced, it means that this constituent component is substantially not contained, and it is allowed that this constituent component is contained at an inevitable impurity level.

[0027] (Notation of glass composition based on oxide) Based on the results obtained by the above analysis, the content (unit: mol %) of each component in the glass composition based on oxide can be calculated. The specific method is as follows. The content of element i (mass % P i ) obtained by the above analysis method is divided by the atomic weight M i of element i to obtain the number of moles n i = P i / M i of each element. When the above element i is the cation component A i , the number of moles n i of the element obtained above is replaced with the number of moles n’ i of the corresponding oxide. Specifically, when the composition formula of the oxide of the cation component A i corresponding to element i is represented by A i xOy, n’ i = n i / x. When the above element i is an anion component B i other than O ions, the number of moles n i of the corresponding above element is hereinafter denoted as m i . In the glass composition based on oxide, the cation component Ai Oxide A i Content as xOy PA i (mol %) is PA i =n' i / (Σn' i +Σm i ) × 100 It is expressed as follows. The content in the oxide-based glass composition can also be called the oxide-based fraction.

[0028] In the oxide-based glass composition, anionic component B other than O ions. i Oxide-based fraction PB i (mol %) is PB i =m i / (Σn' i +Σm i ) × 100 It is represented as follows.

[0029] Here, Σn' i This is oxide A of the cationic components contained in glass. i This is the total number of moles of xOy. However, depending on the significant figures of the content, ignoring trace components will not affect the calculation result.

[0030] (Anion%) "Anion %" is a value calculated as "(the amount of anion i of interest expressed in mole percentage) / (the total number of anions expressed in mole percentage in the glass) × 100", and represents the mole percentage of the amount of anion of interest relative to the total amount of anions. Based on the above explanation of the notation of glass composition based on oxides, the anion percentage of O ions is: Cation component A corresponding to element i i The chemical formula of the oxide is A i Represented as xOy, with cation component A i The number of oxygen atoms contained in the oxide is the cation component A i Oxide-based fraction PA i (using mole%) i =PA i ×y, anionic component B k The valence of Nk When (ΣO i -Σ(N k / 2)B k ) / (ΣO i -Σ(N k / 2)B k +ΣB k ) × 100 It can be calculated as follows. Here ΣO i Σ(N) is the sum of the moles of O ions in the oxide-based glass composition. k / 2)B k is anion component B k This represents the number of moles of O ions substituted by (ΣO). i -Σ(N k / 2)B k This represents the number of moles of oxygen ions contained in the glass. On the other hand, in the present invention and this specification, regarding the oxygen content, if no anionic components other than oxygen are detected by analysis using known methods, it is assumed that all of the anionic components (i.e., 100% anions) are O ions.

[0031] (Cationic component) For the valency of the cationic components, the formal valency of each cation is used. The formal valency is the valency required for the oxide of the cation of interest to maintain electrical neutrality when the valency of the O ion constituting the oxide is -2, and it can be uniquely determined from the chemical formula of the oxide. For example, regarding the Cu ion, the O contained in the chemical formula of the oxide CuO is 2- To maintain electrical neutrality with Cu, the valence of Cu becomes +2. Also, for example, the P ion is included in the chemical formula of the oxide P2O5. 2- To maintain electrical neutrality with P, the valency of P is +2 × 5 / 2 = +5. Generalizing this, the formal valency of the cation Ai contained in the oxide AixOy is "+2y / x". Therefore, when analyzing the glass composition, it is not necessary to analyze the valency of the cation. Furthermore, the valency of anions (for example, the valency of the O ion is -2) is a formal valency based on the idea that the O ion accepts two electrons and takes on a closed-shell structure. Therefore, when analyzing the glass composition, it is not necessary to analyze the valency of anions. Also, Cu 2+ A portion of it is Cu when melted. + This is possible, but usually the amount is so small that it is acceptable to consider the valency of all Cu as +2.

[0032] <Glass 1-6> (Anionic component) Glasses 1 to 6 contain at least O ions as anions, and their content is 90.0% or more in the glass composition expressed as anion percent. The inventors believe that by lowering the O / P ratio in glasses mainly composed of O ions as anions, the absorption of CuO in the red region can be shifted to the longer wavelength side, thereby increasing the CuO content without reducing the transmittance in the red region and improving the near-infrared cutting ability. In glasses 1 to 6, the O ion content in the glass composition expressed as anion percent is 90.0% or more, preferably 95.0% or more, more preferably 98.0% or more, and even more preferably 99.0% or more. A high proportion of O ions in the anion component is also preferable in suppressing volatilization during glass melting. Suppressing volatilization during glass melting is preferable from the viewpoint of suppressing the occurrence of striations. In particular, from the viewpoint of suppressing volatilization during glass melting, increasing productivity, and suppressing the generation of harmful gases during manufacturing, it is preferable that the O ion content be 100%. The formal valency of the O ion is -2.

[0033] Glasses 1-6 can contain only the O ion in one form, and in another form, they can contain the O ion along with one or more other anions. Examples of other anions include the F ion, Cl ion, Br ion, and I ion. The formal valency of the F ion, Cl ion, Br ion, and I ion is -1.

[0034] From the viewpoint of improving the homogeneity and strength of the glass, the F ion content is preferably 15.0 anion% or less, more preferably 10.0 anion% or less, even more preferably 5.0 anion% or less, even more preferably 2.0 anion% or less, and even more preferably 1.0 anion% or less. In particular, from the viewpoint of suppressing volatilization during glass melting, increasing productivity, and suppressing the generation of harmful gases during manufacturing, glasses 1 to 6 may be F ion-free glasses.

[0035] (O / P ratio) In glass composition expressed in atomic percent, the ratio of cation content to anion content is the ratio of the content (expressed in atomic percent) of the component of interest when the total amount of all cationic and anionic components is set to 100 atomic percent. Therefore, the ratio of O ions to P ions (O ions / P ions) is the ratio of P ions to P ions when the total amount of all cationic and anionic components is set to 100 atomic percent. n This is the ratio of the O ion content (expressed as atomic percent) to the total content (expressed as atomic percent).

[0036] Method 1 for calculating the O / P ratio Using a glass with the following composition as an example of an oxide-based glass composition, we will explain how to calculate the O / P ratio (also denoted as R). P2O5: 52.6 moles, Al2O3: 2.6 moles, K2O: 2.7 moles, BaO: 21.6 moles, ZnO: 4.2 moles, CuO: 16.3 moles. The number of oxygen atoms in the molecular formula is 5 for P2O5, 3 for Al2O3, 1 for K2O, 1 for BaO, 1 for ZnO, and 1 for CuO. The number of moles of oxygen in the molecular formula is 263.0 for P2O5, 7.8 for Al2O3, 2.7 for K2O, 21.6 for BaO, 4.2 for ZnO, and 16.3 for CuO. The O / P ratio of the glass in the above example can be determined as follows. The molecular formula of glass is 52.6P2O5-2.6Al2O3-2.7K2O-21.6BaO-4.2ZnO-16.3CuO, where N is the number of oxygen ions. S To determine this, we need to find the molecular formula of glass, which is the compositional formula of glass such that the total number of molecules contained in the glass is 100. That is, using the number of O ions contained in the molecular formula MxOy of each oxide (P2O5:5, Al2O3:3, K2O:1, BaO:1, ZnO:1, CuO:1), N S = 52.6 × 5 + 2.6 × 3 + 2.7 × 1 + 21.6 × 1 + 4.2 × 1 + 16.3 × 1 = 315.7 Ns is calculated as follows. In the example glass above, there are zero oxygen ions substituted by other anions in the molecular formula of the glass. Therefore, by dividing Ns = 315.7 by the number of moles of phosphorus contained in P2O5, which is 52.6 × 2, we can obtain the O / P ratio = 315.7 / (52.6 × 2) = 3.00...

[0037] Method 2 for Calculating the O / P Ratio If analysis by known methods detects one or more anionic components in addition to oxygen, the oxygen content can be determined by the following method (3) (unit: anion %), calculated from (1) the cation content based on the valence and elemental mole percent of the cation components contained in the glass and (2) the anion content based on the valence and elemental mole percent of the anionic components other than oxygen. In other words, based on the results of identification and quantitative analysis using known methods, (1) For the cationic components contained in the glass, calculate the total U based on "the number of oxygen atoms per cation y / x × the mole percentage of the element, which consists of the number of oxygen atoms y and the number of cations x in the oxide MxOy". (2) For anionic components other than oxygen, the total V is calculated from the results of identification and quantitative analysis by known methods and the valence z of the anion, which is "anion content based on the mole percent of the element × the number of oxygen atoms substituted per anion z / 2". (3) UV can also be used as the ratio of O ions to P ions.

[0038] As examples of calculation method 2, calculation example 1 and calculation example 2 are shown below.

[0039] Calculation Example 1: When the molar percentages of P ions, Li ions, and Cu ions are quantified as 22.0, 8.0, and 5.5 (elemental content expressed in molar percentage), the y / x values ​​for the corresponding oxides P2O5, Li2O, and CuO are 2.5, 0.5, and 1.0, respectively. U = 22 × 2.5 + 8 × 0.5 + 5.5 × 1.0 = 64.5, V = 0. Therefore, the molar percentage of O ions, based on the molar percentage of the element, is 64.5 (the content expressed as molar percentage of the element). From the ratio of the O ion value obtained in this way and the molar percentage of the analyzed P ions, the O / P ratio can be calculated as 64.5 / 22 = 2.93...

[0040] Calculation Example 2: When the molar percentages of P ions, Li ions, and Cu ions are 22.0, 8.0, and 5.5 (elemental content expressed in molar percentage), and the molar percentage of F ions is 4.0 (elemental content expressed in molar percentage), the y / x values ​​for the corresponding oxides P2O5, Li2O, and CuO are 2.5, 0.5, and 1.0, respectively, and the valence of F is -1, U = 22 × 2.5 + 8 × 0.5 + 5.5 × 1.0 = 64.5, V = 4 × 1 / 2 = 2. Therefore, the molar percentage of O ions, based on the molar percentage of the element, is 62.5 (the content expressed as molar percentage of the element). From the O ion value obtained in this way and the ratio of the molar percentage of P ions analyzed, the O / P ratio can be calculated as 62.5 / 22 = 2.84...

[0041] In glasses 1 to 6, from the viewpoint of achieving both improved transmittance in the visible range and improved near-infrared cutting ability, as well as improving the thermal stability of the glass, the ratio of O ions to P ions (O / P ratio) in the glass composition expressed in atomic percent is 3.15 or less. In glass 1 to glass 6, the O / P ratio is preferably 3.14 or less, and more preferably 3.13 or less, 3.12 or less, 3.11 or less, and 3.10 or less, in that order. On the other hand, from the viewpoint of improving weather resistance and / or suppressing a decrease in meltability, it is preferable that the O / P ratio is high in Glass 1 to Glass 6. From this point of view, it is preferable that the O / P ratio in Glass 1 to Glass 6 be 2.85 or higher, and more preferably 2.86 or higher, 2.87 or higher, 2.88 or higher, 2.89 or higher, 2.90 or higher, and 3.00 or higher, in that order.

[0042] (Cationic component) Glasses 1-6 contain four or more major cations selected from the group consisting of P ions, Li ions, Cu ions, Al ions, Ba ions, Sr ions, Ca ions, Mg ions, Zn ions, K ions, Na ions, La ions, Gd ions, and Y ions, and contain P ions, Ba ions, and Cu ions as essential cations. In one embodiment, the total content of oxides of the above major cations in the oxide-based glass composition (expressed in mole percent) of glasses 1-6 can be 90.0% or more. In glasses 1 to 6, having a total content of oxides of major cations of 90.0% or more can contribute to improving the thermal stability of the glass and / or to improving the optical homogeneity of the glass by suppressing striations and volatilization. From the above standpoint, the total content of oxides of the major cations in glasses 1 to 6 is preferably 92.0% or more, more preferably 93.0% or more, 95.1% or more, 96.1% or more, 97.1% or more, 98.1% or more, 98.6% or more, 99.1% or more, and 99.6% or more, in that order, and can also be 100%. In one embodiment, the total content of oxides of the major cations in glasses 1 to 6 can be 100% or less, or 99.5% or less, 99% or less, 98.5% or less, 98.0% or less, and 97.5% or less.

[0043] The following explanation of the cationic component content will be given in terms of the content in the glass composition (expressed in mole percent) based on oxides.

[0044] Since CuO is an essential component for giving glass the ability to cut near-infrared rays, glasses 1-6 contain Cu ions as essential cations.

[0045] In glass 1, the CuO content is α1% or more. α1 is a value calculated by the following formula 1.

[0046] (Formula 1) α1 = 70400 × exp(-2.855 × R)

[0047] In Equation 1, R is the O / P ratio.

[0048] Furthermore, for glass 2, the lower limit of the CuO content is determined by the CuO content per molar volume of the glass, as shown in equation 2 below.

[0049] (Formula 2) C-3200×exp(-2.278×R)≧0

[0050] In Equation 2, C is the CuO content per molar volume of glass (unit: millimoles / cc), and R is the O / P ratio.

[0051] In Equation 2, C can be determined by the following method. C measures the specific gravity D (g / cc) of the glass, and based on the glass composition obtained by analysis as described above, determines the mass equivalent to 1 mole of glass composition, i.e., the molar molecular weight M (g / mol), and then calculates the molar volume M / D (unit: cc / mol) of the glass. C = Moles of CuO % / (M / D) × 1000 (Unit: millimoles / cc) It can be calculated as follows. The above molar molecular weight M is, Based on the above explanation of the notation for the oxide-based glass composition, the formula weight MA of the corresponding oxide of the above cation component Ai is i Anion component B k Atomic weight in MB k When the atomic weight of oxygen is Mo, M={Σ(PA i ×MA i )+Σ(PB k ×MB k )-Σ(N k / 2)Mo} / ΣPA i It can be calculated as follows. For example, if the glass composition consists of s mol% A2O component (based on oxide), t mol% BO component (based on oxide), and u mol% F component, where s + t + u = 100 (%), and the formula weight of the A2O component is M A (g / mol), the formula weight of the BO component is M B (g / mol), the atomic weight of F is M F (g / mol), atomic weight of oxygen is M O When (g / mol), M = (s × M) A +t×M B +u×M F -u / 2×M O ) / (s+t) This is the result. For example, the oxide-based glass composition is P2O5: 52.6 mol%, Al2O3: 2.6 mol%.% K2O: 2.7 moles % BaO: 21.6 moles % ZnO: 4.2 moles % CuO: 16.3 moles % Using glass as an example, we will explain how to calculate the molar molecular weight M. Molecular weight of P2O5: 141.94 (g / mol) Molecular weight of Al2O3: 101.96 (g / mol) Molecular weight of K2O: 94.2 (g / mol) Molecular weight of BaO: 153.3 (g / mol) The molecular weight of ZnO is 81.4 g / mol. The molecular weight of CuO is 79.55 (g / mol). Using this, we can calculate M = (52.6 × 141.94 + 2.6 × 101.96 + 2.7 × 94.2 + 21.6 × 153.3 + 4.2 × 81.4 + 16.3 × 79.55) / (52.6 + 2.6 + 2.7 + 21.6 + 4.2 + 16.3) = 129.36 (g / mol).

[0052] As a result of diligent research, the inventors have newly discovered that in a glass mainly composed of O ions as anions, reducing the O / P ratio shifts the absorption of CuO in the red region to the longer wavelength side, thereby suppressing a decrease in transmittance in the red region while increasing the CuO content. Furthermore, the inventors have newly discovered a good correlation between the O / P ratio and the CuO content required to achieve a predetermined half-value at a predetermined wall thickness. As a result, the inventors have determined the lower limits (α1, α2) of the CuO content for glass 1, where the O / P ratio is within the range described above, using Equation 1, and for glass 5, using Equation 5. In addition, the inventors have determined the CuO content per molar volume of glass using Equation 2, where the O / P ratio is within the range described above, and for glass 6, using Equation 6.

[0053] In glass 3, the CuO content is determined based on A1 calculated by the following formula 3, where A1 is 2500 or more.

[0054] (Formula 3) A1 = {O(P) - O(others)} × Cu

[0055] In Equation 3, O(P) represents the amount of oxygen constituting the oxide of the P ion in the oxide-based glass composition, O(others) represents the amount of oxygen obtained by subtracting the above O(P) from the amount of oxygen constituting the oxide of the major cations shown above in glass 3 in the oxide-based glass composition, and Cu represents the CuO content in mole percent in the oxide-based glass composition.

[0056] The "O(P)" in Equation 3 is calculated as follows: When the P2O5 content in the oxide-based glass composition (expressed in mole percent) is M mole percent, the number of oxygen atoms in the chemical formula of P2O5, which is 5, is used, and O(P) is calculated as "O(P) = M × 5". Similarly, for major cations other than P ions, the amount of oxygen constituting the oxide of each cation is calculated using the value of its content as an oxide in the oxide-based glass composition (expressed in mole percent) and the number of oxygen atoms contained in the oxide formed by each cation in its formal valence state. Thus, "O(others)" is calculated by subtracting O(P) from the total amount of oxygen calculated for the oxides of the major cations. When the CuO content in the oxide-based glass composition (expressed in mole percent) is N mole percent, "A" is calculated as A1 = {O(P) - O(others)} × N.

[0057] As described above, the inventors have newly discovered that in a glass mainly composed of O ions as an anion, reducing the O / P ratio shifts the absorption of CuO in the red region to longer wavelengths, thereby suppressing a decrease in transmittance in the red region while increasing the CuO content. Furthermore, they have newly found that by using chemical species other than PO that coordinate to CuO with species having smaller ionic radii and lower valencies, the transmittance in the visible region (purple region to red region) can be increased as a result of 1) and 2) below. Based on these findings, glass 3 is defined based on A, which is calculated by formula 3, and its CuO content is determined accordingly. 1) Cu 2+By shifting the absorption originating from this to longer wavelengths, the transmittance in the red region can be increased. 2) By making it possible to put glass into a liquid state at low temperatures, Cu will produce absorption in the violet region around a wavelength of 400 nm. + This can suppress the occurrence of [unclear].

[0058] Regarding glass 3, from the viewpoint of achieving both improved visible light transmittance and improved near-infrared cut capability, A1 is 2500 or higher, preferably 2800 or higher, and also 2900 or higher, 3000 or higher, 3100 or higher, 3200 or higher, 3300 or higher, 3400 or higher, 3500 or higher, 3600 or higher, 3700 or higher, 3800 or higher, 3900 or higher, 4000 or higher, 4100 or higher, 4200 or higher, and 4 The following are preferred in order: 300 or more, 4400 or more, 4500 or more, 4600 or more, 4700 or more, 4800 or more, 4900 or more, 5000 or more, 5100 or more, 5200 or more, 5300 or more, 5400 or more, 5500 or more, 5600 or more, 5700 or more, 5800 or more, 5900 or more, 6000 or more, 6100 or more, 6200 or more, 6300 or more, 6400 or more, and 6500 or more. On the other hand, from the viewpoint of further suppressing the decrease in thermal stability of the glass due to the large amount of Cu and O, the decrease in transmittance at the desired half-value wavelength, and / or the decrease in thermal stability or weather resistance of the glass due to insufficient O (others), A is preferably 20,000 or less, and more preferably 19,000 or less, 18,000 or less, 17,000 or less, 16,000 or less, 150,000 or less, 14,000 or less, 13,000 or less, 12,000 or less, 11,000 or less, 10,000 or less, 9,000 or less, and 8,000 or less. In addition, to achieve the desired half-value with thinner wall thicknesses, a larger value tends to be preferable.

[0059] In glass 4, the CuO content is determined based on A2 calculated by the following formula 4, where A2 is 700 or more.

[0060] (Formula 4) A2 = {O(P) - O(others)} × C

[0061] In Equation 4, C is the CuO content per molar volume of glass (unit: millimoles / cc). O(P) represents the amount of oxygen constituting the oxide of the P ion in the oxide-based glass composition, and O(others) represents the amount of oxygen obtained by subtracting O(P) from the amount of oxygen constituting the oxide of the above-mentioned major cations in the oxide-based glass composition.

[0062] Regarding glass 4, from the viewpoint of achieving both improved visible-range transmittance and improved near-infrared cut capability, A2 is preferably 700 or higher, more preferably 800 or higher, and more preferably 850 or higher, 890 or higher, 1000 or higher, 1100 or higher, 1200 or higher, 1300 or higher, 1400 or higher, 1500 or higher, 1600 or higher, 1700 or higher, and 1800 or higher, in that order. On the other hand, from the viewpoint of further suppressing the decrease in thermal stability of the glass due to the large amount of Cu and O, the decrease in transmittance at the desired half-value wavelength, and / or the decrease in thermal stability or weather resistance of the glass due to insufficient O (others), A2 is preferably 5000 or lower, more preferably 4000 or lower, 3500 or lower, 3000 or lower, 2500 or lower, and 2000 or lower. Note that in order to achieve the desired half-value transmittance with a thinner thickness, a larger value tends to be preferable.

[0063] Furthermore, in glass 5, the CuO content is α2% or more. α2 is a value calculated from the following formula 5.

[0064] (Formula 5) α² = 76522 × exp(-2.855 × R)

[0065] In equation 5, R is the O / P ratio.

[0066] Furthermore, for glass 6, the lower limit of the CuO content is determined by the CuO content per molar volume of the glass, as shown in formula 6 below.

[0067] (Formula 6) C - 3478 × exp(-2.278 × R) ≥ 0

[0068] In Equation 6, C is the CuO content per molar volume of glass (unit: millimoles / cc), and R is the O / P ratio.

[0069] The CuO content of glasses 1 to 6 is preferably 4.0% or more in terms of the oxide-based glass composition (expressed in mole percent), and is more preferably 5.0% or more, 6.0% or more, 7.0% or more, 7.5% or more, 8.0% or more, 8.5% or more, 9.0% or more, 9.5% or more, 10.0% or more, 10.5% or more, 11.0% or more, 11.5% or more, 12.0% or more, 12.5% ​​or more, 13.0% or more, 13.5% or more, 14.0% or more, 14.5% or more, 15.0% or more, 15.5% or more, 16.0% or more, 16.5% or more, 17.0% or more, 17.5% or more, 18.0% or more, 18.5% or more, 19.0% or more, 19.5% or more, and 20.0% or more, in that order. From the viewpoint of leaving room for the introduction of glass-forming components and maintaining the thermal stability of the glass, the CuO content is preferably 48.0% or less, and further preferably 47.0% or less, 46.0% or less, 45.0% or less, 44.0% or less, 43.5% or less, 43.0% or less, 42.5% or less, 42.0% or less, 41.5% or less, 41.0% or less, 40.5% or less, and 40. The following percentages are preferred in increasing order: 0% or less, 39.5% or less, 39.0% or less, 38.5% or less, 38.0% or less, 37.5% or less, 37.0% or less, 36.5% or less, 36.0% or less, 35.5% or less, 35.0% or less, 34.5% or less, 34.0% or less, 33.5% or less, 33.0% or less, 32.5% or less, 32.0% or less, 31.5% or less, and 31.0% or less.

[0070] As a transmittance characteristic calculated for a thickness of 0.16 mm, the wavelength λ at which the external transmittance, including reflection loss, is 50% is considered to be the transmittance characteristic. T For 50 to be in the range of 600nm to 650nm, the CuO content is preferably 15.0% or more in terms of the oxide-based glass composition (expressed in mole percent), and is more preferably 15.5% or more, 16.0% or more, 16.5% or more, 17.0% or more, 17.5% or more, 18.0% or more, 18.5% or more, 19.0% or more, 19.5% or more, and 20.0% or more, in that order. As a transmittance characteristic calculated for a thickness of 0.21 mm, the wavelength λ at which the external transmittance, including reflection loss, is 50% T For 50 to be in the range of 600nm to 650nm, the CuO content is preferably 10.0% or more in terms of the oxide-based glass composition (expressed in mole percent), and is more preferably 10.5% or more, 11.0% or more, 11.5% or more, 12.0% or more, 12.5% ​​or more, 13.0% or more, 13.5% or more, 14.0% or more, 14.5% or more, 15.0% or more, 15.5% or more, 16.0% or more, 16.5% or more, 17.0% or more, 17.5% or more, 18.0% or more, 18.5% or more, 19.0% or more, 19.5% or more, and 20.0% or more. As a transmittance characteristic calculated for a thickness of 0.25 mm, the wavelength λ at which the external transmittance, including reflection loss, is 50% is considered to be the transmittance characteristic. T For 50 to be in the range of 600nm to 650nm, the CuO content is preferably 10.0% or more in terms of the oxide-based glass composition (expressed in mole percent), and is more preferably 10.5% or more, 11.0% or more, 11.5% or more, 12.0% or more, 12.5% ​​or more, 13.0% or more, 13.5% or more, 14.0% or more, 14.5% or more, 15.0% or more, 15.5% or more, 16.0% or more, 16.5% or more, 17.0% or more, 17.5% or more, 18.0% or more, 18.5% or more, 19.0% or more, 19.5% or more, and 20.0% or more. On the other hand, the transmittance characteristics calculated for a thickness of 0.25 mm show that when the CuO content is high, the wavelength λ at which the external transmittance, including reflection loss, becomes 50%. T Since 50 may be below 600 nm, the CuO content is preferably 35.0% or less, and more preferably in the following order: 34.0% or less, 33.0% or less, 32.0% or less, 31.0% or less, 30.0% or less, 29.5% or less, 29.0% or less, 28.5% or less, 28.0% or less, 27.5% or less, 27.0% or less, 26.5% or less, 26.0% or less, 25.5% or less, 25.0% or less, 24.5% or less, 24.0% or less, 23.5% or less, 23.0% or less, 22.5% or less, 22.0% or less, 21.5% or less, 21.0% or less, 20.5% or less, and 20.0% or less. The wavelength λ at which the external transmittance, including reflection loss, is 50% at wavelengths above 550 nmT For the glass thickness at which 50 is 645 nm to be 0.25 mm or less, the CuO content is preferably 10.0% or more in terms of the oxide-based glass composition (expressed in mole percent), and is more preferably in the order of 10.5% or more, 11.0% or more, 11.5% or more, 12.0% or more, 12.5% ​​or more, 13.0% or more, 13.5% or more, 14.0% or more, 14.5% or more, 15.0% or more, 15.5% or more, 16.0% or more, 16.5% or more, 17.0% or more, 17.5% or more, 18.0% or more, 18.5% or more, 19.0% or more, 19.5% or more, and 20.0% or more. The wavelength λ at which the external transmittance, including reflection loss, is 50% at wavelengths above 550 nm T For the glass thickness at which 50 is 633 nm to be 0.25 mm or less, the CuO content is preferably 10.5% or more in the oxide-based glass composition (expressed in mole percent), and is more preferably in the following order: 11.0% or more, 11.5% or more, 12.0% or more, 12.5% ​​or more, 13.0% or more, 13.5% or more, 14.0% or more, 14.5% or more, 15.0% or more, 15.5% or more, 16.0% or more, 16.5% or more, 17.0% or more, 17.5% or more, 18.0% or more, 18.5% or more, 19.0% or more, 19.5% or more, and 20.0% or more.

[0071] In glass 2 and glass 4, the value of C is preferably 4.0 or higher, more preferably 4.1 or higher, and even more preferably 4.2 or higher. From the viewpoint of leaving room for the introduction of glass-forming components and maintaining the thermal stability of the glass, the value of C is preferably 8.5 or lower, and more preferably in the order of 8.0 or lower, 7.5 or lower, 7.0 or lower, 6.5 or lower, 6.0 or lower, and 5.5 or lower.

[0072] In glasses 1 to 6, the CuO content can be α3% or more. α3 is the value calculated from formula 7 below. In one embodiment, the CuO content of glasses 7 and 8 can be α3% or more.

[0073] (Formula 7) α3=(70400×0.25 / d)×exp(-2.855×R)

[0074] In Equation 7, R is the O / P ratio. d can take values ​​greater than 0 and less than or equal to 0.25. For example, d can be 0.25, 0.24, 0.23, 0.22, 0.21, 0.20, 0.19, 0.18, 0.17, 0.16, 0.15, 0.14, 0.13, 0.12, 0.11, 0.10, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02, 0.01, etc. However, the value of d is not limited to these. To achieve the desired half-value of transmittance with thinner wall thicknesses, a smaller value of d tends to be preferable.

[0075] For example, when d = 0.11, the CuO content can be α3% or more, and α3 is calculated by the following formula. α3=(70400×0.25 / 0.11)×exp(-2.855×R)

[0076] When the thickness of a glass plate is D (mm) such that the external transmittance for light with a wavelength of 633 nm is 50%, in one embodiment, d = D can be expressed in equation 7 above. In this case, α3 is calculated by the following equation. α3=(70400×0.25 / D)×exp(-2.855×R)

[0077] For glasses 1 to 6, the lower limit of the CuO content can also be the value defined by the following formula 8, based on the CuO content per molar volume of the glass.

[0078] (Formula 8) C-3200×0.25 / d×exp(-2.855×R)≧0

[0079] In Equation 8, d can take a value greater than 0 and less than or equal to 0.25. For example, d can be 0.25, 0.24, 0.23, 0.22, 0.21, 0.20, 0.19, 0.18, 0.17, 0.16, 0.15, 0.14, 0.13, 0.12, 0.11, 0.10, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02, 0.01, etc. However, the value of d is not limited to these. To achieve the desired half-value of transmittance with thinner wall thicknesses, a smaller value of d tends to be preferable.

[0080] For example, when d = 0.11, equation 8 is as follows: C-3300×0.25 / 0.11×exp(-2.855×R)≧0

[0081] When the thickness of a glass plate is D (mm) such that the external transmittance for light with a wavelength of 633 nm is 50%, in one embodiment, d = D can be expressed in equation 8 above. In this case, equation 8 is as follows:

[0082] Regarding the CuO content, each of the glasses 1 to 6 may also satisfy one or more of the requirements of the formulas relating to the other glasses.

[0083] Glasses 1-6 contain P ions as essential cations. As mentioned earlier, a low O / P ratio is preferable from the viewpoint of achieving both improved visible light transmittance and improved near-infrared cut capability. To lower the O / P ratio, it is preferable to increase the P2O5 content. From this perspective, the P2O5 content in the oxide-based glass composition (expressed in mole percent) is preferably 33.0% or more, and is more preferably 34.0% or more, 35.0% or more, 36.0% or more, 37.0% or more, 38.0% or more, 39.0% or more, 40.0% or more, 40.5% or more, 41.0% or more, 41.5% or more, 42.0% or more, 42.5% or more, 43.0% or more, 43.5% or more, 44.0% or more, 44.5% or more, 45.0% or more, 45.5% or more, 46.0% or more, 46.5% or more, 47.0% or more, 47.5% or more, 48.0% or more, 48.5% or more, 49.0% or more, 49.5% or more, and 50.0% or more, in that order. Since P2O5 itself is a component that does not possess near-infrared absorption capabilities, from the viewpoint of increasing the CuO content, which does possess near-infrared absorption capabilities, the P2O5 content is preferably 72.0% or less, and more preferably in the following order: 71.0% or less, 70.0% or less, 69.5% or less, 69.0% or less, 68.5% or less, 68.0% or less, 67.5% or less, 67.0% or less, 66.5% or less, 66.0% or less, 65.5% or less, 65.0% or less, 64.5% or less, 64.0% or less, 63.5% or less, 63.0% or less, 62.5% or less, 62.0% or less, 61.5% or less, 61.0% or less, 60.5% or less, and 60.0% or less. Furthermore, having a P2O5 content below the above values ​​is also preferable from the viewpoint of further suppressing the decrease in weather resistance and / or suppressing the decrease in melting properties.

[0084] For Glasses 1 to 6, it is desirable that the glass composition on an oxide basis be mainly composed of P2O5, BaO, and CuO in order to obtain the desired transmittance characteristics. From this point of view, the total content of P2O5, BaO, and CuO (P2O5 + BaO + CuO) is preferably 70.0% or more, more preferably 75.0% or more, 80.0% or more, and 85.0% or more in that order. Glasses 1 to 6 contain P ions, Ba ions, and Cu ions as essential cations, and further contain one or more cations selected from the group of main cations in order to obtain the thermal stability and / or chemical durability of the glass. Therefore, the total content (P2O5 + BaO + CuO) is less than 100%, preferably 99.0% or less, more preferably 98.0% or less, 97.0% or less, 96.0% or less, 95.0% or less, 94.0% or less, 93.0% or less, 92.0% or less, and 91.0% or less in that order.

[0085] In one form, as the transmittance characteristic in terms of a thickness of 0.16 mm, the wavelength λ at which the external transmittance including reflection loss becomes 50% T In order for λ50 to be in the range of 600 nm to 650 nm, the total content of P2O5, BaO, and CuO (P2O5 + BaO + CuO) is preferably 84.0% or more, more preferably 85.0% or more, 86.0% or more, 87.0% or more, 88.0% or more, 89.0% or more, and 90.0% or more in that order in the glass composition on an oxide basis (in mol%). As the transmittance characteristic in terms of a thickness of 0.21 mm, the wavelength λ at which the external transmittance including reflection loss becomes 50% T In order for λ50 to be in the range of 600 nm to 650 nm, P2O 5、 The total content of BaO and CuO (P2O5 + BaO + CuO) is preferably 80.0% or more, more preferably 81.0% or more, 82.0% or more, 83.0% or more, 84.0% or more, 85.0% or more, 86.0% or more, 87.0% or more, 88.0% or more, 89.0% or more, and 90.0% or more in that order in the glass composition on an oxide basis (in mol%). As the transmittance characteristic in terms of a thickness of 0.25 mm, the wavelength λ at which the external transmittance including reflection loss becomes 50% TFor 50 to be in the range of 600nm to 650nm, the total content of P2O5, BaO, and CuO (P2O5 + BaO + CuO) is preferably 75.0% or more in terms of the oxide-based glass composition (expressed in mole percent), and is more preferably 76.0% or more, 77.0% or more, 78.0% or more, 79.0% or more, 80.0% or more, 81.0% or more, 82.0% or more, 83.0% or more, 84.0% or more, 85.0% or more, 86.0% or more, 87.0% or more, 88.0% or more, 89.0% or more, and 90.0% or more, in that order. The wavelength λ at which the external transmittance, including reflection loss, is 50% at wavelengths above 550 nm T In order for the glass thickness at which 50 is 645 nm to be 0.25 mm or less, the total content of P2O5, BaO, and CuO (P2O5 + BaO + CuO) is preferably 80.0% or more in terms of the oxide-based glass composition (expressed in mole percent), and is more preferably 81.0% or more, 82.0% or more, 83.0% or more, 84.0% or more, 85.0% or more, 86.0% or more, 87.0% or more, 88.0% or more, 89.0% or more, and 90.0% or more, in that order. The wavelength λ at which the external transmittance, including reflection loss, is 50% at wavelengths above 550 nm T For the glass thickness at which 50 is 633 nm to be 0.25 mm or less, the total content of P2O5, BaO, and CuO (P2O5 + BaO + CuO) is preferably 81.0% or more in terms of the oxide-based glass composition (expressed in mole percent), and is more preferably 82.0% or more, 83.0% or more, 84.0% or more, 85.0% or more, 86.0% or more, 87.0% or more, 88.0% or more, 89.0% or more, and 90.0% or more, in that order.

[0086] On the other hand, as another form, for glass where the molar ratio of the total content of MgO, CaO, SrO, BaO, and ZnO (MgO+CaO+SrO+BaO+ZnO) to the total content of Li2O, Na2O, and K2O (Li2O+Na2O+K2O) ((MgO+CaO+SrO+BaO+ZnO) / (Li2O+Na2O+K2O)) is 2.0 or higher, the wavelength λ at which the external transmittance, including reflection loss, is 50% is calculated as the transmittance characteristic for a thickness of 0.16 mm. TIn order for 50 to be in the range of 600 nm to 650 nm, the total content of P2O5, BaO and CuO (P2O5 + BaO + CuO) is preferably 65.0% or more, more preferably 66.0% or more, 67.0% or more, 68.0% or more, 69.0% or more, 70.0% or more in the glass composition based on oxides (in mol%). Regarding the other form described above, as the transmittance characteristic in terms of a thickness of 0.21 mm, the wavelength λ at which the external transmittance including reflection loss becomes 50% T In order for 50 to be in the range of 600 nm to 650 nm, the total content of P2O5, BaO and CuO (P2O5 + BaO + CuO) is preferably 60.0% or more, more preferably 61.0% or more, 62.0% or more, 63.0% or more, 64.0% or more, 65.0% or more in the glass composition based on oxides (in mol%). Regarding the other form described above, as the transmittance characteristic in terms of a thickness of 0.25 mm, the wavelength λ at which the external transmittance including reflection loss becomes 50% T In order for 50 to be in the range of 600 nm to 650 nm, the total content of P2O5, BaO and CuO (P2O5 + BaO + CuO) is preferably 55.0% or more, more preferably 56.0% or more, 57.0% or more, 58.0% or more, 59.0% or more, 60.0% or more in the glass composition based on oxides (in mol%). Regarding the other form described above, the wavelength λ at which the external transmittance including reflection loss becomes 50% at a wavelength of 550 nm or more T In order for the thickness of the glass for which 50 is 645 nm to be 0.25 mm or less, the total content of P2O5, BaO and CuO (P2O5 + BaO + CuO) is preferably 60.0% or more, more preferably 61.0% or more, 62.0% or more, 63.0% or more, 64.0% or more, 65.0% or more in the glass composition based on oxides (in mol%). Regarding the other form described above, the wavelength λ at which the external transmittance including reflection loss becomes 50% at a wavelength of 550 nm or more TFor the glass thickness at which 50 is 633 nm to be 0.25 mm or less, the total content of P2O5, BaO, and CuO (P2O5 + BaO + CuO) is preferably 61.0% or more in terms of oxide-based glass composition (expressed in mole percent), with 62.0% or more, 63.0% or more, 64.0% or more, 65.0% or more, and 66.0% or more being the most preferred values.

[0087] In one form, glass 1 to 6 may be glass containing one or both B ions and Si ions, which tend to shift the half value to the shorter wavelength side, from the viewpoint of enhancing the near-infrared cutting ability of the glass and improving the transmittance in the visible range, while in another form, it may be glass that does not contain either B ions or Si ions.

[0088] For glasses 1 to 6, in terms of the oxide-based glass composition (expressed in mole percent), from the viewpoint of further improving the transmittance in the visible range, the total content of B2O3 and SiO2 (B2O3 + SiO2) is preferably 3.0% or less, and more preferably in the order of 2.5% or less, 2.0% or less, 1.5% or less, 1.0% or less, and 0.5% or less.

[0089] In glass 1 to 6, the total content of B2O3 and SiO2 (B2O3 + SiO2) can be 0%, 0% or more, or greater than 0%.

[0090] In glass 1-6, from the perspective of further improving the transmittance in the visible range, B2O3 of The content is preferably 3.0% or less, and more preferably 2.5% or less, 2.0% or less, 1.5% or less, 1.0% or less, and 0.5% or less, in that order. The B2O3 content can also be 0%. On the other hand, with respect to glasses 1 to 6, when rough melting of the glass is performed in a quartz crucible to promote glass homogenization, the SiO2 content is preferably greater than 0%, with the order of preference being 0.01% or more, 0.02% or more, 0.03% or more, 0.04% or more, 0.05% or more, 0.1% or more, 0.2% or more, and 0.3% or more. However, the introduction of excessive SiO2 into the glass tends to reduce the optical homogeneity of the glass. From this point of view, the SiO2 content of glasses 1 to 6 is preferably 2.0% or less, with the order of preference being 1.4% or less, 0.9% or less, 0.8% or less, 0.6% or less, and 0.4% or less.

[0091] Glasses 1 to 6 contain Li ions in one form and do not contain Li ions in another form. Compared to various glass components, Li2O has a high ability to maintain CuO absorption in the long-wavelength range and also has a small adverse effect on weather resistance. From this viewpoint, the Li2O content can be 0% or more or greater than 0%, preferably 0.1% or more, and more preferably 0.5% or more, 1.0% or more, and 1.2% or more in that order. On the other hand, from the viewpoint of ensuring the thermal stability of the glass and / or further suppressing and maintaining the deterioration of weather resistance, the Li2O content is preferably 13.0% or less, and more preferably 12.0% or less, 11.0% or less, 10.0% or less, 9.0% or less, 8.0% or less, 7.0% or less, 6.0% or less, 5.0% or less, 4.0% or less, 3.0% or less, and 2.8% or less in that order. A Li2O content of 7.0% or less is preferable from the viewpoint of suppressing deliquescence of the glass.

[0092] In glasses 1 to 6, the total content of MgO and Al2O3 (MgO + Al2O3) is preferably 8.0% or less, and more preferably 7.5% or less, from the viewpoint of improving solubility, transmittance in the visible range, and near-infrared absorption characteristics. The order of preference is 7.0% or less, 6.5% or less, 6.0% or less, 5.5% or less, 5.0% or less, 4.5% or less, 4.0% or less, 3.5% or less, 3.0% or less, 2.5% or less, 2.0% or less, 1.8% or less, 1.6% or less, 1.5% or less, and 1.4% or less, and it may also be 0%. On the other hand, the total content of MgO and Al2O3 (MgO + Al2O3) can be greater than 0% from the viewpoint of improving the weather resistance of the glass and improving the mechanical strength of the glass, and is preferably 0.1% or more, in the order of 0.2% or more, 0.3% or more, 0.4% or more, 0.5% or more, 0.6% or more, 0.7% or more, 0.8% or more, 0.9% or more, 1.0% or more, 1.1% or more, and 1.3% or more.

[0093] In glasses 1 to 6, Al2O3 is a component that can particularly contribute to improving weather resistance. The Al2O3 content can be 0%, 0% or more, or greater than 0%, and from the viewpoint of improving weather resistance, it is preferably 0.1% or more, followed by 0.2% or more, 0.3% or more, 0.4% or more, 0.5% or more, 0.6% or more, 0.7% or more, 0.9% or more, 1.1% or more, and 1.2% or more, in that order. On the other hand, from the viewpoint of further suppressing the decrease in transmittance in the visible range, the Al2O3 content is preferably 6.0% or less, followed by 5.5% or less, 5.0% or less, 4.5% or less, 4.0% or less, 3.5% or less, 3.0% or less, and 2.8% or less, in that order. In one embodiment, prioritizing the improvement of near-infrared absorption characteristics over maintaining the weather resistance of the glass, and suppressing the short-wavelength shift of CuO absorption to further increase the transmittance in the visible range and improve near-infrared absorption characteristics, the Al2O3 content is preferably less than 2.0%, and more preferably in the order of 1.9% or less, 1.8% or less, 1.7% or less, 1.6% or less, 1.5% or less, 1.4% or less, 1.3% or less, 1.2% or less, 1.1% or less, 1.0% or less, 0.9% or less, 0.8% or less, 0.7% or less, 0.6% or less, and 0.5% or less.

[0094] In glasses 1 to 6, MgO is a component that can be added as appropriate to adjust the thermal stability of the glass. However, it tends to shift the absorption of CuO to the shorter wavelength side and worsen the near-infrared absorption characteristics, making it difficult to increase the CuO content. Also, the fusionability of the glass tends to decrease with increasing MgO content. From these viewpoints, the MgO content is preferably 9.0% or less, and more preferably 8.0% or less, 7.0% or less, 6.0% or less, 5.0% or less, 4.0% or less, 3.0% or less, and 2.0% or less, in that order. The MgO content can also be 0%. In one embodiment, from the viewpoint of improving the mechanical strength of the glass, the MgO content can be greater than 0%, preferably 0.5% or more, and more preferably 1.0% or more.

[0095] La2O3 is a component that can contribute to improving the weather resistance of glass without impairing its near-infrared absorption properties. The La2O3 content is preferably 0.10% or more, and more preferably 0.15% or more, 0.18% or more, and 0.21% or more, in that order. On the other hand, from the viewpoint of further suppressing the decrease in transmittance in the visible range, the La2O3 content is preferably 8.0% or less, and more preferably 7.0% or less, 6.5% or less, 6.0% or less, 5.5% or less, 5.0% or less, 4.5% or less, 4.0% or less, 3.5% or less, 3.0% or less, 2.5% or less, 2.0% or less, 1.5% or less, and 1.0% or less, in that order. The La2O3 content may be 0%.

[0096] Y2O3 is also a component that can contribute to improving the weather resistance of glass without impairing its near-infrared absorption properties. The Y2O3 content is preferably 0.10% or more, and is more preferably 0.15% or more, 0.20% or more, 0.25% or more, 0.30% or more, 0.35% or more, 0.40% or more, 0.45% or more, and 0.50% or more, in that order. On the other hand, from the viewpoint of further suppressing the decrease in transmittance in the visible range, the Y2O3 content is preferably 8.0% or less, and is more preferably 7.0% or less, 6.5% or less, 6.0% or less, 5.5% or less, 5.0% or less, 4.5% or less, 4.0% or less, 3.5% or less, 3.0% or less, 2.5% or less, 2.0% or less, 1.5% or less, and 1.0% or less, in that order. The Y2O3 content may be 0%. Y2O3 can also be introduced from the viewpoint of increasing the molar volume of glass without increasing the specific gravity of the glass.

[0097] Gd2O3 is also a component that can contribute to improving weather resistance. The Gd2O3 content is preferably 0.10% or more, and more preferably 0.15% or more, 0.18% or more, and 0.21% or more, in that order. On the other hand, from the viewpoint of further suppressing the decrease in transmittance in the visible range, the Gd2O3 content is preferably 8.0% or less, and more preferably 7.0% or less, 6.5% or less, 6.0% or less, 5.5% or less, 5.0% or less, 4.5% or less, 4.0% or less, 3.5% or less, 3.0% or less, 2.5% or less, 2.0% or less, 1.5% or less, and 1.0% or less, in that order. The Gd2O3 content may be 0%.

[0098] Furthermore, the oxide-based glass composition may or may not include one or more other rare earth oxides such as Lu2O3 and Sc2O3. Since these components are generally expensive, the content of rare earth oxides other than La2O3, Y2O3, and Gd2O3 (the total content if two or more are included) is preferably 2.5% or less, preferably 1.5% or less, 1.0%, 0.5% or less, and may even be 0%.

[0099] In glass 1 to 6, the total content of Al2O3, La2O3, Y2O3, and Gd2O3 (Al2O3 + La2O3 + Y2O3 + Gd2O3) is preferably 0.1% or more from the viewpoint of improving weather resistance, and is more preferably 0.15% or more, 0.20% or more, 0.25% or more, 0.30% or more, 0.35% or more, 0.40% or more, 0.45% or more, and 0.50% or more, in that order. On the other hand, the total content (Al2O3 + La2O3 + Y2O3 + Gd2O3) is preferably 8.0% or less from the viewpoint of ensuring the thermal stability of the glass and / or lowering the melting temperature, and is more preferably 7.0% or less, 6.5% or less, 6.0% or less, 5.5% or less, 5.0% or less, 4.5% or less, 4.0% or less, 3.5% or less, 3.0% or less, 2.5% or less, 2.0% or less, 1.5% or less, and 1.0% or less, in that order.

[0100] In glasses 1 to 6, the Ba ion is an essential cation. The BaO content of glasses 1 to 6 can be greater than 0%. BaO is a component that can improve weather resistance when introduced in a certain amount and tends to be less prone to deliquescence compared to alkali metal oxides. In addition, BaO can be added to improve the thermal stability of the glass and adjust its solubility. Furthermore, BaO can contribute to lowering T1200, but excessive introduction tends to lower T400. T1200 and T400 will be discussed later. From the above viewpoint, in glasses 1 to 6, the BaO content is preferably 10.0% or more, and more preferably 11.0% or more. Also from the above viewpoint, in glasses 1 to 6, the BaO content is preferably 23.0% or less, and more preferably 22.0% or less.

[0101] SrO content is 0% 、The SrO content can be 0% or more, or greater than 0%. Similar to BaO, SrO is a component that does not significantly reduce weather resistance and can be added as appropriate for reasons such as adjusting the thermal stability of the glass. SrO can also be used to adjust the concentration of CuO. The SrO content is preferably 0.5% or more, and is more preferably 1.0% or more, 1.5% or more, 2.0% or more, 2.5% or more, 3.0% or more, 3.5% or more, 4.0% or more, 4.5% or more, 5.0% or more, 5.5% or more, 6.0% or more, 6.5% or more, and 7.0% or more, in that order. However, since excessive introduction tends to lower T400, the SrO content is preferably 30.0% or less, and is more preferably 29.0% or less, 28.0% or less, 27.0% or less, and 26.0% or less. 、2 The following percentages are preferred in order: 5.0% or less, 24.0% or less, 23.0% or less, 22.0% or less, 21.0% or less, 20.0% or less, 19.0% or less, 18.0% or less, 17.0% or less, 16.0% or less, 15.0% or less, 14.0% or less, 13.0% or less, 12.0% or less, 11.0% or less, 10.0% or less, and 9.0% or less.

[0102] CaO content is 0% 、 The CaO content can be 0% or more or greater than 0%. CaO is a component that does not significantly reduce weather resistance and can be added as appropriate for reasons such as adjusting the thermal stability of the glass. CaO can also be used to adjust the concentration of CuO. The CaO content is preferably 0.5% or more, and preferably 1.0% or more, 1.5% or more, 2.0% or more, 2.5% or more, 3.0% or more, 3.5% or more, 4.0% or more, 4.5% or more, 5.0% or more, 5.5% or more, 6.0% or more, 6.5% or more, and 7.0% or more. However, since excessive introduction tends to lower T400, the CaO content should be... Preferably, it should be 30.0% or less, and also 29.0% or less, 28.0% or less, 27.0% or less, and 26.0% or less. 、2The following percentages are preferred in order: 5.0% or less, 24.0% or less, 23.0% or less, 22.0% or less, 21.0% or less, 20.0% or less, 19.0% or less, 18.0% or less, 17.0% or less, 16.0% or less, 15.0% or less, 14.0% or less, 13.0% or less, 12.0% or less, 11.0% or less, 10.0% or less, and 9.0% or less.

[0103] The Na2O content can be 0%, 0% or more, or greater than 0%. Excessive Na2O introduction tends to reduce weather resistance. For this reason, the Na2O content is preferably 5.0% or less, and more preferably 4.0% or less, 3.0% or less, 2.0% or less, and 1.0% or less, in that order.

[0104] The K2O content can be 0%, 0% or more, or greater than 0%. Among alkali metal oxides, K2O has the effect of improving near-infrared absorption characteristics more than Li2O and Na2O. On the other hand, excessive introduction of K2O tends to reduce weather resistance. From these viewpoints, the K2O content is preferably 10.0% or less, and more preferably 9.0% or less, 8.0% or less, 7.0% or less, 6.0% or less, 5.0% or less, 4.0% or less, 3.0% or less, 2.0% or less, and 1.0% or less, in that order.

[0105] The Cs2O content can be 0%, 0% or more, or greater than 0%. Since Cs2O also tends to reduce weather resistance, it is desirable not to actively introduce it. The Cs2O content is more preferably 15.0% or less, 14.0% or less, 13.0% or less, 12.0% or less, 11.0% or less, 10.0% or less, 9.0% or less, 8.0% or less, 7.0% or less, and 6.0% or less, in that order. On the other hand, in order to adjust thermal stability and meltability, the Cs2O content can be 0.5% or more, and can also be 1.0% or more, 1.5% or more, 2.0% or more, 2.5% or more, 3.0% or more, 3.5% or more, and 4.0% or more.

[0106] The total content of Li2O, Na2O, and K2O (Li2O + Na2O + K2O) can be 0%, 0% or more, or greater than 0%. From the viewpoint of further suppressing the deterioration of weather resistance, the total content (Li2O + Na2O + K2O) is preferably 15.0% or less, and more preferably 14.0% or less, 13.0% or less, 12.0% or less, 11.0% or less, and 10.0% or less, in that order. Having the total content (Li2O + Na2O + K2O) below the above values ​​is also preferable from the viewpoint of avoiding the increase in the expansion and contraction of the glass due to an increase in the coefficient of thermal expansion, which can cause stress on the glass when the volume change of the glass is restricted by other components, resulting in chipping or cracking of the glass.

[0107] From the viewpoint of suppressing glass deliquescence, the total content of Na2O and K2O (Na2O + K2O) is preferably 15.0% or less, and more preferably 14.0% or less, 13.0% or less, 12.0% or less, 11.0% or less, 10.0% or less, and 9.0% or less, in that order. The total content of Na2O and K2O (Na2O + K2O) can be 0%, 0% or more, or greater than 0%. By setting the total content of Na2O and K2O (Na2O + K2O) to 0%, it is possible to obtain glass that suppresses deliquescence even further. On the other hand, from the viewpoint of suppressing the fusion properties of glass and reducing the T600 while suppressing the raw material costs of glass, the total content (Na2O + K2O) can be set to 1.0% or more, and furthermore, it can be set to 2.0% or more, 3.0% or more, 4.0% or more, 5.0% or more, 6.0% or more, 7.0% or more, 8.0% or more, 9.0% or more, 10.0% or more, 11.0% or more, 12.0% or more, 13.0% or more, 14.0% or more, and 15.0% or more.

[0108] Regarding weather resistance, the suppression of glass deliquescence and the suppression of the formation of precipitates on the glass surface under high temperature and high humidity conditions, or both, can be used as indicators of weather resistance. This point will be discussed further later. To further improve weather resistance, the introduction of Al2O3 is more preferable, followed by the introduction of one or more of Y2O3, La2O3, and Gd2O3. Furthermore, the introduction of BaO in relatively large amounts can improve the above-mentioned weather resistance, and SrO and CaO require even larger amounts to improve weather resistance. Therefore, the value calculated as "(3×Al2O3+Y2O3+La2O3+Gd2O3+BaO / 3+(CaO+SrO) / 6)" (unit: mol%) is preferably 0% or more, more preferably greater than 0%, and preferably 0.5% or more, 1.0% or more, 2.0% or more, 3.0% or more, 4.0% or more, 5.0% or more, 6.0% or more, 7.0% or more, and 8.0% or more. Furthermore, when prioritizing the weather resistance and mechanical strength of the glass, the following percentages are preferable in order: 9.0% or more, 10.0% or more, 11.0% or more, 12.0% or more, 13.0% or more, 14.0% or more, 15.0% or more, 16.0% or more, 17.0% or more, 18.0% or more, and 19.0% or more. In "(3×Al2O3+Y2O3+La2O3+Gd2O3+BaO / 3+(CaO+SrO) / 6)", "Al2O3" is the Al2O3 content, "Y2O3" is the Y2O3 content, "La2O3" is the La2O3 content, "Gd2O3" is the Gd2O3 content, "BaO" is the BaO content, "CaO" is the CaO content, and "SrO" is the SrO content. That is, "(3×Al2O3+Y2O3+La2O3+Gd2O3+BaO / 3+(CaO+SrO) / 6)" is the sum of the value calculated by multiplying the Al2O3 content by 3, the values ​​calculated by dividing the Y2O3 content, La2O3 content, Gd2O3 content, and BaO content by 1 / 3, and the value calculated by dividing the sum of the CaO content and SrO content by 1 / 6. The value thus calculated shall be expressed with the unit % (mol%). On the other hand, if the value of "(3×Al2O3+Y2O3+La2O3+Gd2O3+BaO / 3+(CaO+SrO) / 6)" is made too large, the fusion properties of the glass tend to deteriorate, and the position of near-infrared absorption tends to shift towards the visible light side. Therefore, the value calculated as "(3×Al2O3+Y2O3+La2O3+Gd2O3+BaO / 3+(CaO+SrO) / 6)" is preferably 40.0% or less, and is more preferably 37.0% or less, 35.0% or less, 33.0% or less, 32.0% or less, 30.0% or less, 28.0% or less, 26.0% or less, 25.0% or less, 24.0% or less, 23.0% or less, 22.0% or less, and 21.0% or less, in that order.

[0109] The ratio of the value calculated by "(3×Al2O3+Y2O3+La2O3+Gd2O3+BaO / 3+(CaO+SrO) / 6)" to the total content of P2O5, BaO, and CuO, i.e., "(3×Al2O3+Y2O3+La2O3+Gd2O3+BaO / 3+(CaO+SrO) / 6) / (P2O5+BaO+CuO)", can be 0.0 or greater. It is desirable to introduce a certain amount or more of the component selected from the group consisting of Al2O3, Y2O3, La2O3, Gd2O3, BaO, CaO, and SrO relative to the essential components P2O5, BaO, and CuO. Therefore, the above ratio is preferably 0.05 or greater, and is more preferably 0.06 or greater, 0.07 or greater, 0.08 or greater, 0.09 or greater, 0.10 or greater, and 0.11 or greater, in that order. On the other hand, if the above ratio is made too large, the transmittance characteristics of the glass will decrease, and furthermore, the stability of the glass will tend to decrease. Therefore, the above ratio is preferably 0.32 or less, and is more preferably 0.30 or less, 0.28 or less, 0.26 or less, 0.24 or less, 0.22 or less, 0.20 or less, and 0.18 or less, in that order.

[0110] The ZnO content can be 0%, 0% or more, or greater than 0%. ZnO is a component that can be added as appropriate for reasons such as adjusting the thermal stability of the glass, but it may worsen the near-infrared absorption characteristics compared to other divalent components (especially BaO, SrO, and CaO). Furthermore, from the viewpoint of ensuring a sufficient amount of the essential component P2O5, the upper limit of its content is preferably 10.0% or less, with 9.0% or less, 8.0% or less, 7.0% or less, 6.0% or less, and 5.0% or less being the most preferred values ​​in that order. On the other hand, when ZnO is introduced to adjust the thermal stability of the glass or to lower Tg and / or Tm, the preferred values ​​are 0.4% or more, 0.6% or more, 0.8% or more, 1.0% or more, 1.2% or more, 1.4% or more, 1.6% or more, 1.8% or more, and 2.0% or more being the most preferred values ​​in that order.

[0111] Glass 1 to 6 are preferably composed primarily of the above-mentioned components, but other components may be included as long as they do not interfere with the effects of the above-mentioned components. Furthermore, this does not exclude the inclusion of unavoidable impurities in Glass 1 to 6.

[0112] For example, Nb2O5 and ZrO2 may be introduced as components other than those mentioned above to adjust the weather resistance, mechanical strength, or thermal stability of the glass, in amounts of more than 0%, 0.1% or more, or 0.2% or more, respectively. However, the content of each component should preferably be 5.0% or less, with the order of preference being 4.0% or less, 3.0% or less, 2.0% or less, 1.0% or less, 0.5% or less, and 0.3% or less. The content of each of these components may also be 0%.

[0113] TiO2, WO3, and Bi2O3 may also be introduced as components other than those mentioned above, in amounts greater than 0%, 0.1% or more, or 0.2% or more, respectively, to adjust the weather resistance, mechanical strength, or thermal stability of the glass, as long as it does not affect the transmittance of the glass. However, the content of each component should preferably be 4.0% or less, with the order of preference being 3.0% or less, 2.0% or less, 1.0% or less, 0.5% or less, and 0.3% or less. The content of each of these components may also be 0%.

[0114] Pb, As, Cd, Tl, Be, and Se are all toxic. Therefore, it is preferable that glasses 1 to 6 do not contain these as glass components.

[0115] U, Th, and Ra are all radioactive elements. Therefore, it is preferable that glasses 1 to 6 do not contain these elements as glass components.

[0116] V, Cr, Mn, Fe, Co, Ni, Pr, Nd, Pm, Sm, Eu, Tb, Dy, Ho, Er, and Tm can increase the coloration of glass and become sources of fluorescence. Therefore, in glasses 1 to 6, it is preferable that the total content of these elements on an oxide basis is 10 ppm by mass or less, and it is even more preferable that these elements are not included as glass components.

[0117] In particular, it is preferable not to use V2O5 because it is toxic and worsens the transmittance characteristics in the visible range. Specifically, in one embodiment, it is preferable that glasses 1 to 6 are glass that does not contain V ions, and in the oxide-based glass composition (expressed in mole percent), the V2O5 content is preferably 1.0% or less, more preferably 0.3% or less, 0.1% or less, and more preferably 0.01% or less, in that order, and even more preferably no V2O5 at all.

[0118] As an example, the ratio of V2O5 to the essential component Li2O, namely the ratio of V2O5 content to Li2O content (V2O5 / Li2O), is preferably 0.0080 or less, with 0.0048 or less, 0.0028 or less, 0.0018 or less, and 0.0014 or less being the most preferred values.

[0119] CoO is preferable to avoid using it because it reduces the visible light transmittance of the glass and is also toxic. In other words, in one embodiment, glasses 1 to 6 are preferably Co-ion-free glasses, and it is preferable that the oxide-based glass composition does not contain CoO.

[0120] The raw materials for introducing Ge and Ta into glass are expensive. Therefore, it is preferable that glasses 1 to 6 do not contain these as glass components.

[0121] Sb(Sb2O3), Sn(SnO2), Ce(CeO2), and SO3 are optional additives that function as clarifying agents. Of these, Sb(Sb2O3) is a clarifying agent with a significant clarifying effect. Sn(SnO2) and Ce(CeO2) have a smaller clarifying effect compared to Sb(Sb2O3). Adding large amounts of these clarifying agents tends to increase the discoloration of the glass. Therefore, when adding a clarifying agent, it is preferable to add Sb(Sb2O3) while considering the effect of the added discoloration.

[0122] The content of the components that can function as clarifying agents listed below is given based on the oxide-based glass composition.

[0123] The Sb2O3 content is expressed as an external percentage. That is, when the total content of all glass components other than Sb2O3, SnO2, CeO2, and SO3 as oxides is set to 100.0% by mass, the Sb2O3 content is preferably less than 2.0% by mass, and is more preferably in the order of 1.5% by mass or less, 1.2% by mass or less, 1.0% by mass or less, 0.9% by mass or less, 0.8% by mass or less, 0.7% by mass or less, 0.6% by mass or less, 0.5% by mass or less, 0.4% by mass or less, 0.3% by mass or less, 0.2% by mass or less, and less than 0.1% by mass. The Sb2O3 content may be 0% by mass. However, from the viewpoint of promoting the oxidation of the glass and increasing the transmittance in the visible range, the Sb2O3 content can be 0.01% by mass or more, and can also be 0.02% by mass or more, 0.03% by mass or more, 0.04% by mass or more, 0.05% by mass or more, 0.06% by mass or more, or 0.08% by mass or more.

[0124] The SnO2 content is also expressed as an external percentage. That is, when the total content of all glass components other than SnO2, Sb2O3, CeO2, and SO3 as oxides is set to 100.0% by mass, the SnO2 content is preferably less than 2.0% by mass, more preferably less than 1.0% by mass, more preferably 0.9% by mass or less, 0.8% by mass or less, 0.7% by mass or less, 0.6% by mass or less, 0.5% by mass or less, 0.4% by mass or less, 0.3% by mass or less, 0.2% by mass or less, and more preferably 0.1% by mass. The SnO2 content may be 0% by mass. The clarity of the glass can be improved by setting the SnO2 content within the above range.

[0125] The CeO2 content is also expressed as an external percentage. That is, when the total content of all glass components other than CeO2, Sb2O3, SnO2, and SO3 as oxides is set to 100.0% by mass, the CeO2 content is preferably less than 2.0% by mass, more preferably less than 1.0% by mass, more preferably 0.9% by mass or less, 0.8% by mass or less, 0.7% by mass or less, 0.6% by mass or less, 0.5% by mass or less, 0.4% by mass or less, 0.3% by mass or less, 0.2% by mass or less, and more preferably less than 0.1% by mass. The CeO2 content may also be 0% by mass. The clarity of the glass can be improved by setting the CeO2 content within the above range.

[0126] The SO3 content will also be displayed separately. 3、 When the total content of all glass components other than Sb2O3, SnO2, and CeO2 as oxides is taken as 100.0% by mass, the SO3 content is preferably in the range of less than 2.0% by mass, more preferably less than 1.0% by mass, even more preferably less than 0.5% by mass, and even more preferably less than 0.1% by mass. The SO3 content may also be 0% by mass. By setting the SO3 content within the above range, the clarity of the glass can be improved.

[0127] In one form, Glass 1 to 6 have a glass composition expressed in mol% on an oxide basis in which the ratio of BaO content to Li2O content (BaO / Li2O) is 1.0 or more, and can satisfy one or more of the following (1) to (4). Glass 1 to 6 can satisfy only one of the following (1) to (4), two or more, three or more, or four. (1) The ratio of the total content of CaO, SrO, and ZnO to the BaO content ((CaO+SrO+ZnO) / BaO) is 0.02 or higher. (2) The ratio of the total content of CaO, SrO, and ZnO to the total content of MgO and BaO ((CaO + SrO + ZnO) / (MgO + BaO)) but 0.02 or higher, (3) The ratio of the total content of K2O + CaO + SrO to the BaO content ((K2O + CaO + SrO) / BaO) is 0.12 or more. (4) The ratio of the total content of K2O, CaO, SrO, and ZnO to the total content of MgO and BaO ((K2O+CaO+SrO+ZnO) / (MgO+BaO)) is 0.12 or greater.

[0128] <Glass 7> Next, we will explain glass 7.

[0129] Glass 7 is a near-infrared absorbing glass whose glass composition, expressed in mol% based on oxides, is as follows: P2O5 content is 40.0-65.0 mol%, CuO content is 9.0-25.0 mol%, BaO content is 5-50 mol%, The total content of Li2O, Na2O, and K2O (Li2O + Na2O + K2O) is 1.0 to 15.0 mol%, SiO2 content is 2.0 mol% or less. B2O3 content is 2.0 mol% or less. Al2O3 content is 0.5 to 7.0 moles %、 Li2O content is 7.0 mol% or less. ZnO content is 10.0 mol% or less. PbO content is 2.0 mol% or less. The ratio of MgO content to the total content of MgO, CaO, SrO, and BaO (MgO / (MgO+CaO+SrO+BaO)) is 0.3 or less. In the glass composition expressed in atomic percent, the ratio of O ions to P ions (O ions / P ions) is 3.50 or less. In the glass composition expressed in anion percentage, the F ion content is 10.0 anion% or less.

[0130] In glass 7, the P2O5 content, CuO content, BaO content, total Li2O, Na2O and K2O content, SiO2 content, B2O3 content, Al2O3 content, Li2O content, ZnO content, PbO content, and the ratio of MgO content to the total MgO, CaO, SrO and BaO content are within the above range. In such glass 7, from the viewpoint of achieving both improved visible light transmittance and improved near-infrared cut capability, and from the viewpoint of improving the thermal stability of the glass, the ratio of O ions to P ions (O / P ratio) in the glass composition expressed in atomic percent is 3.50 or less. In glass 7, the O / P ratio is preferably 3.40 or less, followed by 3.30 or less, and then 3.20 or less. To impart to the glass 7, when converted to a thickness of 0.25 mm or less such that the external transmittance at wavelengths of 620 to 650 nm is 50%, the external transmittance at wavelengths of 400 nm is 75% or more and the external transmittance at wavelengths of 1200 nm is 7% or less, the O / P ratio is preferably 3.15 or less, and more preferably 3.10 or less, and more preferably 3.05 or less. On the other hand, from the viewpoint of improving weather resistance and / or suppressing a decrease in meltability, a high O / P ratio is preferable for the glass 7. From this point of view, the O / P ratio for the glass 7 is preferably 2.85 or more, and more preferably 2.86 or more, 2.87 or more, 2.88 or more, 2.89 or more, 2.90 or more, and more preferably 3.00 or more.

[0131] The following provides a more detailed explanation of the oxide-based glass composition (expressed in mole percent) of Glass 7.

[0132] The CuO content of glass 7 is 9.0% or more, and is preferably in the following order: 9.5% or more, 10.0% or more, 10.5% or more, 11.0% or more, 11.5% or more, 12.0% or more, 12.5% ​​or more, 13.0% or more, 13.5% or more, 14.0% or more, 14.5% or more, 15.0% or more, 15.5% or more, 16.0% or more, 16.5% or more, 17.0% or more, 17.5% or more, 18.0% or more, 18.5% or more, 19.0% or more, 19.5% or more, and 20.0% or more. From the viewpoint of leaving room for the introduction of glass-forming components and maintaining the thermal stability of the glass, the CuO content should be 25.0% or less, and is preferred in the following order: 24.5% or less, 24.0% or less, 23.5% or less, 23.0% or less, 22.5% or less, 22.0% or less, 21.5% or less, 21.0% or less, and 20.5% or less.

[0133] As a transmittance characteristic calculated for a thickness of 0.16 mm, the wavelength λ at which the external transmittance, including reflection loss, is 50% is considered to be the transmittance characteristic. T For 50 to be in the range of 600nm to 650nm, the CuO content is preferably 15.0% or more, and more preferably in the order of 15.5% or more, 16.0% or more, 16.5% or more, 17.0% or more, 17.5% or more, 18.0% or more, 18.5% or more, 19.0% or more, 19.5% or more, and 20.0% or more. As a transmittance characteristic calculated for a thickness of 0.21 mm, the wavelength λ at which the external transmittance, including reflection loss, is 50% T For 50 to be in the range of 600nm to 650nm, the CuO content is preferably 10.0% or more, and is more preferably 10.5% or more, 11.0% or more, 11.5% or more, 12.0% or more, 12.5% ​​or more, 13.0% or more, 13.5% or more, 14.0% or more, 14.5% or more, 15.0% or more, 15.5% or more, 16.0% or more, 16.5% or more, 17.0% or more, 17.5% or more, 18.0% or more, 18.5% or more, 19.0% or more, 19.5% or more, and 20.0% or more. As a transmittance characteristic calculated for a thickness of 0.25 mm, the wavelength λ at which the external transmittance, including reflection loss, is 50% is considered to be the transmittance characteristic.T For 50 to be in the range of 600nm to 650nm, the CuO content is preferably 10.0% or more, and is more preferably 10.5% or more, 11.0% or more, 11.5% or more, 12.0% or more, 12.5% ​​or more, 13.0% or more, 13.5% or more, 14.0% or more, 14.5% or more, 15.0% or more, 15.5% or more, 16.0% or more, 16.5% or more, 17.0% or more, 17.5% or more, 18.0% or more, 18.5% or more, 19.0% or more, 19.5% or more, and 20.0% or more. On the other hand, the transmittance characteristics calculated for a thickness of 0.25 mm show that when the CuO content is high, the wavelength λ at which the external transmittance, including reflection loss, becomes 50%. T Since 50 may be below 600 nm, the CuO content is more preferably 25.0% or less, 24.5% or less, 24.0% or less, 23.5% or less, 23.0% or less, 22.5% or less, 22.0% or less, 21.5% or less, 21.0% or less, 20.5% or less, and 20.0% or less, in that order. The wavelength λ at which the external transmittance, including reflection loss, is 50% at wavelengths above 550 nm T For the glass thickness at which 50 is 645 nm to be 0.25 mm or less, the CuO content is preferably 10.0% or more, and more preferably in the following order: 10.5% or more, 11.0% or more, 11.5% or more, 12.0% or more, 12.5% ​​or more, 13.0% or more, 13.5% or more, 14.0% or more, 14.5% or more, 15.0% or more, 15.5% or more, 16.0% or more, 16.5% or more, 17.0% or more, 17.5% or more, 18.0% or more, 18.5% or more, 19.0% or more, 19.5% or more, and 20.0% or more. The wavelength λ at which the external transmittance, including reflection loss, is 50% at wavelengths above 550 nm TFor the glass thickness at which 50 is 633 nm to be 0.25 mm or less, the CuO content is preferably 10.5% or more, and more preferably in the following order: 11.0% or more, 11.5% or more, 12.0% or more, 12.5% ​​or more, 13.0% or more, 13.5% or more, 14.0% or more, 14.5% or more, 15.0% or more, 15.5% or more, 16.0% or more, 16.5% or more, 17.0% or more, 17.5% or more, 18.0% or more, 18.5% or more, 19.0% or more, 19.5% or more, and 20.0% or more.

[0134] Glass 7 contains P2O5 as an essential component. As mentioned earlier, a low O / P ratio is preferable from the viewpoint of achieving both improved visible light transmittance and improved near-infrared cut capability. To lower the O / P ratio, it is preferable to increase the P2O5 content. From this point of view, the P2O5 content of glass 7 is 40.0% or more, and is preferably 41.0% or more, 42.0% or more, 43.0% or more, 44.0% or more, 45.0% or more, 46.0% or more, 47.0% or more, 48% or more, 49.0% or more, 50% or more, 51.0% or more, and 52.0% or more, in that order. Since P2O5 itself is a component that does not possess near-infrared absorption capabilities, from the viewpoint of increasing the CuO content, which does possess near-infrared absorption capabilities, the P2O5 content is preferably 65.0% or less, followed by 64.0% or less, 63.0% or less, 62.0% or less, 61.0% or less, 60.0% or less, 59.0% or less, 58.0% or less, 57.0% or less, 56.0% or less, 55.0% or less, 54.0% or less, and 53.0% or less, in that order. Furthermore, having a P2O5 content below the above values ​​is also preferable from the viewpoint of further suppressing the decrease in weather resistance and / or suppressing the decrease in melting properties.

[0135] In one embodiment, glass 7 may be a glass containing one or both of B2O3 and SiO2, which tend to shift the half value to the shorter wavelength side in an oxide-based glass composition, from the viewpoint of enhancing the near-infrared cutting ability of the glass and improving the transmittance in the visible range. In another embodiment, glass may contain neither B2O3 nor SiO2. In glass 7, from the perspective of further improving the transmittance in the visible range,B 2 O The content of 3 is 2.0% or less, with 1.5% or less, 1.0% or less, and 0.5% or less being preferred in that order. The B2O3 content can also be 0%. On the other hand, with respect to glass 7, when rough melting of the glass is performed in a quartz crucible to promote glass homogenization, the SiO2 content is preferably greater than 0%, with the order of preference being 0.01% or more, 0.02% or more, 0.03% or more, 0.04% or more, 0.05% or more, 0.1% or more, 0.2% or more, and 0.3% or more. However, the introduction of excessive SiO2 into the glass tends to reduce the optical homogeneity of the glass. From this point of view, the SiO2 content in glass 7 is preferably 2.0% or less, with the order of preference being 1.4% or less, 0.9% or less, 0.8% or less, 0.6% or less, and 0.4% or less. In glass 7, from the viewpoint of further improving the transmittance in the visible range, the B2O3 content is 2.0% or less, and is preferably 1.5% or less, 1.0% or less, and 0.5% or less, in that order. The B2O3 content can also be 0%. 。

[0136] Glass 7, in its oxide-based glass composition, contains Li2O in one form and does not contain Li2O in the other form. Compared to various glass components, Li2O has a high ability to maintain CuO absorption in the long-wavelength range and has little adverse effect on weather resistance. From this viewpoint, the Li2O content can be 0% or more or greater than 0%, preferably 0.1% or more, and more preferably 0.5% or more, 1.0% or more, and 1.2% or more, in that order. On the other hand, from the viewpoint of ensuring the thermal stability of the glass and / or further suppressing and maintaining the deterioration of weather resistance, the Li2O content in glass 7 is 7.0% or less, preferably 6.0% or less, 5.0% or less, 4.0% or less, 3.0% or less, and 2.8% or less, in that order. A Li2O content of 7.0% or less is also preferable from the viewpoint of suppressing deliquescence of the glass.

[0137] In glass 7, Al2O3 is a component that can particularly contribute to improving weather resistance. From the viewpoint of improving weather resistance, the Al2O3 content is preferably 0.5% or more, in the order of 0.6% or more, 0.7% or more, 0.9% or more, 1.1% or more, and 1.2% or more. On the other hand, from the viewpoint of further suppressing the decrease in transmittance in the visible range and improving near-infrared transmittance characteristics, the Al2O3 content is preferably 7.0% or less, in the order of 6.5% or less, 6.0% or less, 5.5% or less, 5.0% or less, 4.5% or less, 4.0% or less, 3.5% or less, 3.0% or less, and 2.5% or less.

[0138] In glass 7, MgO is a component that can be added as appropriate to adjust the thermal stability of the glass, but it tends to make it difficult to increase the CuO content because it shifts the absorption of CuO to the shorter wavelength side and worsens the near-infrared absorption characteristics. Also, the fusionability of the glass tends to decrease with increasing MgO content. From these viewpoints, the MgO content is preferably 9.0% or less, and more preferably 8.0% or less, 7.0% or less, 6.0% or less, 5.0% or less, 4.0% or less, 3.0% or less, and 2.0% or less, in that order. The MgO content can also be 0%. In one embodiment, from the viewpoint of improving the mechanical strength of the glass, the MgO content can be greater than 0%, preferably 0.5% or more, and more preferably 1.0% or more.

[0139] La2O3 is a component that can contribute to improving the weather resistance of glass without impairing its near-infrared absorption properties. The La2O3 content is preferably 0.10% or more, and more preferably 0.15% or more, 0.18% or more, and 0.21% or more, in that order. On the other hand, from the viewpoint of further suppressing the decrease in transmittance in the visible range, the La2O3 content is preferably 8.0% or less, and more preferably 7.0% or less, 6.5% or less, 6.0% or less, 5.5% or less, 5.0% or less, 4.5% or less, 4.0% or less, 3.5% or less, 3.0% or less, 2.5% or less, 2.0% or less, 1.5% or less, 1.0% or less, 0.5% or less, and 0.1% or less, in that order. It can also be 0%. The La2O3 content may be 0%.

[0140] Y2O3 is also a component that can contribute to improving weather resistance without impairing the near-infrared absorption characteristics of glass. The Y2O3 content is preferably 0.10% or more, and is more preferably 0.15% or more, 0.20% or more, 0.25% or more, 0.30% or more, 0.35% or more, 0.40% or more, 0.45% or more, and 0.50% or more, in that order. On the other hand, from the viewpoint of further suppressing the decrease in transmittance in the visible range, the Y2O3 content is preferably 8.0% or less, and is more preferably 7.0% or less, 6.5% or less, 6.0% or less, 5.5% or less, 5.0% or less, 4.5% or less, 4.0% or less, 3.5% or less, 3.0% or less, 2.5% or less, 2.0% or less, 1.5% or less, 1.0% or less, 0.5% or less, and 0.1% or less, in that order. The Y2O3 content may be 0%. Furthermore, Y2O3 can be introduced to increase the molar volume of glass without increasing its specific gravity.

[0141] Gd2O3 is also a component that can contribute to improving weather resistance. The Gd2O3 content is preferably 0.10% or more, and more preferably 0.15% or more, 0.18% or more, and 0.21% or more, in that order. On the other hand, from the viewpoint of further suppressing the decrease in transmittance in the visible range, the Gd2O3 content is preferably 8.0% or less, and more preferably 7.0% or less, 6.5% or less, 6.0% or less, 5.5% or less, 5.0% or less, 4.5% or less, 4.0% or less, 3.5% or less, 3.0% or less, 2.5% or less, 2.0% or less, 1.5% or less, 1.0% or less, 0.5% or less, and 0.1% or less, in that order. The Gd2O3 content may be 0%.

[0142] The oxide-based glass composition may or may not contain one or more rare earth oxides other than those mentioned above, such as Lu2O3 and Sc2O3. Since these components are generally expensive, the content of rare earth oxides other than La2O3, Y2O3, and Gd2O3 (the total content if two or more are included) is preferably 2.5% or less, preferably 1.5% or less, 1.0%, 0.5% or less, and may even be 0%.

[0143] In glass 7, the total content of Al2O3, La2O3, Y2O3, and Gd2O3 (Al2O3 + La2O3 + Y2O3 + Gd2O3) is preferably 0.5% or more from the viewpoint of improving weather resistance, and is more preferably 0.55% or more, 0.60% or more, 0.65% or more, 0.70% or more, 0.75% or more, 0.80% or more, 0.85% or more, and 0.90% or more, in that order. On the other hand, the total content (Al2O3 + La2O3 + Y2O3 + Gd2O3) is preferably 8.0% or less from the viewpoint of ensuring the thermal stability of the glass and / or lowering the melting temperature, and is more preferably 7.0% or less, 6.5% or less, 6.0% or less, 5.5% or less, 5.0% or less, 4.5% or less, 4.0% or less, 3.5% or less, 3.0% or less, 2.5% or less, 2.0% or less, 1.5% or less, and 1.0% or less, in that order.

[0144] In the oxide-based glass composition of glass 7, BaO is an essential component. BaO is a component that can improve weather resistance when introduced in a certain amount, and tends to be less prone to deliquescence compared to alkali metal oxides. In addition, BaO can be added to improve the thermal stability of the glass and adjust its solubility. Furthermore, BaO can contribute to lowering T1200, but excessive introduction tends to lower T400. T1200 and T400 will be discussed later. From the above viewpoint, in glass 7, the BaO content is 5.0% or more, and is preferred in the order of 10.0% or more, 15.0% or more, 17% or more, 19% or more, and 21% or more. Also from the above viewpoint, in glass 7, the BaO content is 50.0% or less, and is preferred in the order of 45.0% or less, 40.0% or less, 35.0% or less, 30.0% or less, 28.0% or less, 26.0% or less, and 24.0% or less.

[0145] The SrO content can be 0%, 0% or more, or greater than 0%. Similar to BaO, SrO is a component that does not significantly reduce weather resistance and can be added as appropriate to adjust the thermal stability of the glass. SrO can also be used to adjust the concentration of CuO. The SrO content is preferably 0.5% or more, and is more preferably 1.0% or more, 1.5% or more, 2.0% or more, 2.5% or more, 3.0% or more, 3.5% or more, 4.0% or more, 4.5% or more, 5.0% or more, 5.5% or more, 6.0% or more, 6.5% or more, and 7.0% or more, in that order. However, since excessive introduction tends to lower T400, the SrO content is preferably 30.0% or less, and is more preferably 29.0% or less, 28.0% or less, 27.0% or less, and 26.0% or less. 、2 The following percentages are preferred in order: 5.0% or less, 24.0% or less, 23.0% or less, 22.0% or less, 21.0% or less, 20.0% or less, 19.0% or less, 18.0% or less, 17.0% or less, 16.0% or less, 15.0% or less, 14.0% or less, 13.0% or less, 12.0% or less, 11.0% or less, 10.0% or less, and 9.0% or less.

[0146] The CaO content can be 0%, 0% or more, or greater than 0%. CaO is a component that does not significantly reduce weather resistance and can be added as appropriate for reasons such as adjusting the thermal stability of the glass. CaO can also be used to adjust the concentration of CuO. The CaO content is preferably 0.5% or more, and is most preferably 1.0% or more, 1.5% or more, 2.0% or more, 2.5% or more, 3.0% or more, 3.5% or more, 4.0% or more, 4.5% or more, 5.0% or more, 5.5% or more, 6.0% or more, 6.5% or more, and 7.0% or more, in that order. However, since excessive introduction tends to lower T400, the CaO content is preferably 30.0% or less, and is most preferably 29.0% or less, 28.0% or less, 27.0% or less, and 26.0% or less. 、2It is more preferable in the order of 5.0% or less, 24.0% or less, 23.0% or less, 22.0% or less, 21.0% or less, 20.0% or less, 19.0% or less, 18.0% or less, 17.0% or less, 16.0% or less, 15.0% or less, 14.0% or less, 13.0% or less, 12.0% or less, 11.0% or less, 10.0% or less, 9.0% or less.

[0147] The Na2O content can be 0%, 0% or more, or more than 0%. Excessive introduction of Na2O tends to reduce weather resistance. Therefore, the Na2O content is preferably 5.0% or less, and more preferably 4.0% or less, 3.0% or less, 2.0% or less, 1.0% or less in this order.

[0148] The K2O content can be 0%, 0% or more, or more than 0%. Among the same alkalis, Li2O and has an effect of improving the near-infrared absorption characteristics compared to Na2O, but excessive introduction of K2O also tends to reduce weather resistance. From these viewpoints, the K2O content is preferably 10.0% or less, and more preferably 9.0% or less, 8.0% or less, 7.0% or less, 6.0% or less, 5.0% or less, 4.0% or less, 3.0% or less, 2.0% or less, 1.0% or less in this order.

[0149] The Cs2O content can be 0%, 0% or more, or more than 0%. Since Cs2O also tends to reduce weather resistance, it is desirable not to introduce it actively. The Cs2O content is more preferably 15.0% or less, 14.0% or less, 13.0% or less, 12.0% or less, 11.0% or less, 10.0% or less, 9.0% or less, 8.0% or less, 7.0% or less, 6.0% or less in this order. On the other hand, for adjusting thermal stability and melting properties, the Cs2O content can be 0.5% or more, and can also be 1.0% or more, 1.5% or more, 2.0% or more, 2.5% or more, 3.0% or more, 3.5% or more, 4.0% or more.

[0150] In glass 7, from the viewpoints of melting property and near-infrared absorption property, the total content of Li2O, Na2O and K2O (Li2O + Na2O + K2O) is 1.0% or more, preferably 2.0% or more, and more preferably 3.0% or more. From the viewpoint of further suppressing the deterioration of weather resistance, the total content (Li2O + Na2O + K2O) is 15.0% or less, preferably 14.0% or less, 13.0% or less, 12.0% or less, 11.0% or less, 10.0% or less, 9% or less, 8% or less, 7% or less, 6% or less, 5% or less, 4% or less in this order. That the total content (Li2O + Na2O + K2O) is below the above value is also preferable from the viewpoint of avoiding the occurrence of chips or cracks in the glass due to the increase in the amount of expansion and contraction of the glass caused by the increase in the thermal expansion coefficient and the application of stress to the glass when the volume change of the glass is restricted by other members.

[0151] The ZnO content can be 0%, 0% or more, or more than 0%. ZnO is a component that can be appropriately added for reasons such as adjusting the thermal stability of the glass. However, from the viewpoint of ensuring a sufficient introduction amount of P2O5 which is an essential component, the ZnO content in glass 7 is 10.0% or less, preferably 9.0% or less, 8.0% or less, 7.0% or less, 6.0% or less, 5.0% or less, 4.0% or less, 3.0 or less, 2.5% or less in this order. On the other hand, when ZnO is introduced to adjust the thermal stability of the glass and lower Tg and / or Tm, the ZnO content is more preferably 0.4% or more, 0.6% or more, 0.8% or more, 1.0% or more, 1.2% or more, 1.4% or more, 1.6% or more, 1.8% or more, 2.0% or more in this order.

[0152] In glass 7, from the viewpoint of maintaining both the weather resistance and the near-infrared transmittance absorption property, the ratio of the MgO content to the total content of MgO, CaO, SrO and BaO (MgO / (MgO + CaO + SrO + BaO)) is 0.3 or less, preferably 0.25 or less, 0.20 or less, 0.15 or less, 0.10 or less, 0.05 or less in this order, and it can also be 0.

[0153] Glass 7 is preferably composed primarily of the above-mentioned components, but it may also contain other components as long as they do not interfere with the effects of the above-mentioned components. Furthermore, this does not exclude the inclusion of unavoidable impurities in glass 7. For example, Nb2O5 and ZrO2 may be introduced as components other than those mentioned above, in amounts greater than 0%, 0.1% or more, or 0.2% or more, respectively, to adjust the weather resistance or mechanical strength of the glass, or to improve its thermal stability. The content of each component is preferably 5.0% or less, with 4.0% or less, 3.0% or less, 2.0% or less, 1.0% or less, 0.5% or less, and 0.3% or less being the most desirable in that order. The content of each component may also be 0%.

[0154] TiO2, WO3, and Bi2O3 may also be introduced as components other than those mentioned above, in amounts greater than 0%, 0.1% or more, or 0.2% or more, respectively, to adjust the weather resistance, mechanical strength, or thermal stability of the glass, as long as it does not affect the transmittance of the glass. However, the content of each component should preferably be 4.0% or less, with the order of preference being 3.0% or less, 2.0% or less, 1.0% or less, 0.5% or less, and 0.3% or less. The content of each of these components may also be 0%.

[0155] In glass 7, the PbO content is 2.0 mol% or less. Since Pb is toxic, it is preferable that the PbO content in glass 7 be 0%.

[0156] As, Cd, Tl, Be, and Se are all toxic. Therefore, it is preferable that glass 7 does not contain these as glass components.

[0157] U, Th, and Ra are all radioactive elements. Therefore, it is preferable that glass 7 does not contain these elements as glass components.

[0158] V, Cr, Mn, Fe, Co, Ni, Pr, Nd, Pm, Sm, Eu, Tb, Dy, Ho, Er, and Tm can increase the coloration of glass and become sources of fluorescence. Therefore, in glass 7, it is preferable that the total content of these elements on an oxide basis is 10 ppm by mass or less, and it is even more preferable that these elements are not included as glass components. In particular, V2O5 is toxic and therefore worsens the transmittance characteristics in the visible range, so it is preferable not to use it. That is, in one embodiment, glass 7 is preferably glass that does not contain V2O5, and in the oxide-based glass composition (expressed in mole percent), the V2O5 content is preferably 1.0% or less, more preferably 0.3% or less, 0.1% or less, and more preferably 0.01% or less, in that order, and even more preferably V2O5-free. CoO is preferable to avoid using it because it reduces the visible light transmittance of the glass and is also toxic. In other words, in one embodiment, it is preferable that the glass 7 is glass that does not contain CoO. The raw materials for introducing Ge and Ta into glass are expensive. Therefore, it is preferable that glass 7 does not contain these as glass components.

[0159] Sb(Sb2O3), Sn(SnO2), Ce(CeO2), and SO3 are optional additives that function as clarifying agents. Of these, Sb(Sb2O3) is a clarifying agent with a significant clarifying effect. Sn(SnO2) and Ce(CeO2) have a smaller clarifying effect compared to Sb(Sb2O3). Adding large amounts of these clarifying agents tends to increase the discoloration of the glass. Therefore, when adding a clarifying agent, it is preferable to add Sb(Sb2O3) while considering the effect of the added discoloration. The content of the components that can function as clarifying agents listed below is given based on the oxide-based glass composition. The Sb2O3 content is expressed as an external percentage. That is, when the total content of all glass components other than Sb2O3, SnO2, CeO2, and SO3 as oxides is set to 100.0% by mass, the Sb2O3 content is preferably less than 2.0% by mass, and is more preferably in the order of 1.5% by mass or less, 1.2% by mass or less, 1.0% by mass or less, 0.9% by mass or less, 0.8% by mass or less, 0.7% by mass or less, 0.6% by mass or less, 0.5% by mass or less, 0.4% by mass or less, 0.3% by mass or less, 0.2% by mass or less, and less than 0.1% by mass. The Sb2O3 content may be 0% by mass. However, from the viewpoint of promoting the oxidation of the glass and increasing the transmittance in the visible range, the Sb2O3 content can be 0.01% by mass or more, and can also be 0.02% by mass or more, 0.03% by mass or more, 0.04% by mass or more, 0.05% by mass or more, 0.06% by mass or more, or 0.08% by mass or more. The SnO2 content is also expressed as an external percentage. That is, when the total content of all glass components other than SnO2, Sb2O3, CeO2, and SO3 as oxides is set to 100.0% by mass, the SnO2 content is preferably less than 2.0% by mass, more preferably less than 1.0% by mass, more preferably 0.9% by mass or less, 0.8% by mass or less, 0.7% by mass or less, 0.6% by mass or less, 0.5% by mass or less, 0.4% by mass or less, 0.3% by mass or less, 0.2% by mass or less, and more preferably 0.1% by mass. The SnO2 content may be 0% by mass. The clarity of the glass can be improved by setting the SnO2 content within the above range. The CeO2 content is also expressed as an external percentage. That is, when the total content of all glass components other than CeO2, Sb2O3, SnO2, and SO3 as oxides is set to 100.0% by mass, the CeO2 content is preferably less than 2.0% by mass, more preferably less than 1.0% by mass, more preferably 0.9% by mass or less, 0.8% by mass or less, 0.7% by mass or less, 0.6% by mass or less, 0.5% by mass or less, 0.4% by mass or less, 0.3% by mass or less, 0.2% by mass or less, and more preferably less than 0.1% by mass. The CeO2 content may also be 0% by mass. The clarity of the glass can be improved by setting the CeO2 content within the above range. The SO3 content will also be displayed separately. 3、When the total content of all glass components other than Sb2O3, SnO2, and CeO2 as oxides is taken as 100.0% by mass, the SO3 content is preferably in the range of less than 2.0% by mass, more preferably less than 1.0% by mass, even more preferably less than 0.5% by mass, and even more preferably less than 0.1% by mass. The SO3 content may also be 0% by mass. By setting the SO3 content within the above range, the clarity of the glass can be improved.

[0160] In one form, glass 7 can satisfy one or more of the following conditions (1) to (4). Glass 7 can satisfy only one of the following conditions (1) to (4), two or more, three or more, or four. (1) The ratio of the total content of CaO, SrO, and ZnO to the BaO content ((CaO+SrO+ZnO) / BaO) is 0.02 or higher. (2) The ratio of the total content of CaO, SrO, and ZnO to the total content of MgO and BaO ((CaO + SrO + ZnO) / (MgO + BaO)) but 0.02 or higher, (3) The ratio of the total content of K2O + CaO + SrO to the BaO content ((K2O + CaO + SrO) / BaO) is 0.12 or more. (4) The ratio of the total content of K2O, CaO, SrO, and ZnO to the total content of MgO and BaO ((K2O+CaO+SrO+ZnO) / (MgO+BaO)) is 0.12 or greater.

[0161] In the glass composition expressed as anion percentage, glass 7 can contain at least O ions as anions, and its content can be 90.0% anion or more. The inventors believe that by lowering the O / P ratio in a glass mainly composed of O ions as anions, the absorption of CuO in the red region can be shifted to the longer wavelength side, thereby increasing the CuO content without reducing the transmittance in the red region and improving the near-infrared cutting ability. In glass 7, the O ion content in the glass composition expressed as anion percentage is preferably 95.0% or more, more preferably 98.0% or more, and even more preferably 99.0% or more. A high proportion of O ions in the anion component is also preferable in suppressing volatilization during glass melting. Suppressing volatilization during glass melting is preferable from the viewpoint of suppressing the occurrence of striations. In particular, from the viewpoint of suppressing volatilization during glass melting, increasing productivity, and suppressing the generation of harmful gases during manufacturing, it is preferable that the O ion content be 100%.

[0162] In the glass composition expressed as anion percentage, glass 7 may contain only the O ion in one form, and may contain one or more other anions along with the O ion in another form. Examples of other anions include the F ion, Cl ion, Br ion, I ion, etc.

[0163] In the glass composition of glass 7 expressed in anion percentage, the F ion content is preferably 10.0 anion% or less, more preferably 5.0 anion% or less, more preferably 2.0 anion% or less, and even more preferably 1.0 anion% or less, from the viewpoint of improving the homogeneity and strength of the glass. In particular, from the viewpoint of suppressing volatilization during glass melting, increasing productivity, and suppressing the generation of harmful gases during manufacturing, glass 7 may also be glass that does not contain F ions.

[0164] <Glass 8> Next, we will explain glass 8.

[0165] The glass 8 has a thickness of 0.25 mm or less, and in terms of the thickness at which the external transmittance becomes 50% at a wavelength of 620 to 650 nm, has a transmittance characteristic that the external transmittance at a wavelength of 400 nm is 75% or more and the external transmittance at a wavelength of 1200 nm is 7% or less, and has an average linear expansion coefficient (hereinafter, also referred to as "α(100~300℃)") at 100 to 300 °C of 135×10 -7 / K or less, and is a near-infrared absorbing glass. In other words, regarding the above transmittance characteristic, in terms of the thickness at which the external transmittance becomes 50% at a wavelength of 620 to 650 nm, the thickness at which the external transmittance at a wavelength of 400 nm is 75% or more, and in terms of the thickness at which the external transmittance becomes 50% at a wavelength of 620 to 650 nm, the thickness at which the external transmittance at a wavelength of 1200 nm is 7% or less is called T1. Then, there is one or more T1 within the range of 0.25 mm or less.

[0166] In one form, the glass 8 has a thickness of 0.23 mm or less, and in terms of the thickness at which the external transmittance becomes 50% at a wavelength of 625 to 650 nm, has a transmittance characteristic that the external transmittance at a wavelength of 400 nm is 80% or more and the external transmittance at a wavelength of 1200 nm is 5% or less, and has an average linear expansion coefficient at 100 to 300 °C of 130×10 -7 / K or less, and can be a near-infrared absorbing glass. In other words, regarding the above transmittance characteristic, 5 in terms of the thickness at which the external transmittance becomes 50% at a wavelength of 62 5 ~650 nm, the thickness at which the external transmittance at a wavelength of 400 nm is 80% or more, and in terms of the thickness at which the external transmittance becomes 50% at a wavelength of 62 ~650 nm, the thickness at which the external transmittance at a wavelength of 1200 nm is 5% or less is called T2. Then, there is one or more T2 within the range of 0.23 mm or less.

[0167] In recent years, small cameras, such as those found in smartphones, do not simply digitize the acquired image information, but also reconstruct the image by performing various computer processing operations on that image information. For example, it has become common practice to extract a specific object and adjust the color and contrast of the image. In this process, if color information that does not originally exist is input to the image sensor due to the reflection of light in the optical element, that information must be removed, which is undesirable. To achieve both high performance and miniaturization, near-infrared absorbing glass should have a thickness of 0.25 mm or less (even 0.23 mm). (below) It is desirable that such a thing be the case. Near-infrared absorbing glass having the above transmittance characteristics at such a thickness is preferable from the viewpoint of achieving both high performance and miniaturization.

[0168] On the other hand, if the α (100-300°C) of the glass is large, the glass becomes prone to cracking due to thermal shock during the heating process before depositing an anti-reflective film by vapor deposition, etc., to reduce reflection loss after polishing the glass to a thickness of 0.25 mm or less (even 0.23 mm or less), and during the cooling process after film deposition. Conversely, if the heating and cooling rates of the glass in each process are slowed down to prevent cracking due to thermal shock, productivity will decrease. In contrast, if the α (100-300°C) is 135 × 10⁻¹⁰, -7 / K or less (preferably 130 × 10 -7 / K below The glass 8 is preferred from the viewpoint of being able to prevent glass breakage due to thermal shock while maintaining productivity.

[0169] The transmittance characteristics of glass 8 are determined by the transmittance characteristic measurement method described later.

[0170] The α (100-300°C) of glass shall be measured using a thermomechanical analyzer. For example, the α (100-300°C) of glass can be measured using a cylindrical glass sample with a diameter of 5 mm and a length of 20 mm, and a Bruker axs thermomechanical analyzer "TMA4000s". The heating rate of the sample during measurement can be set to 4°C / min.

[0171] Regarding the glass composition of glass 8, only one of the items previously described for glasses 1 to 7 may be applied, or two or more of the items previously described for glasses 1 to 7 may be applied in any combination. One or more of the items previously described for one of the glasses 1 to 7 may be arbitrarily combined with one or more of the items previously described for the other glasses to be applied to the glass composition of glass 8. For example, one or more of the items previously described for glass 1 may be combined with one or more of the items previously described for glass 2 to be applied to the glass composition of glass 8. Another example is that one or more of the items previously described for glass 1 may be combined with one or more of the items previously described for glass 2 and one or more of the items previously described for glass 3 to be applied to the glass composition of glass 8. Furthermore, the examples are not limited to these, and any combination is possible.

[0172] <Glass Properties> Next, we will explain the glass properties that glasses 1 to 8 may possess.

[0173] (Transmittance characteristics) Glasses 1 to 8 are suitable as glass for near-infrared cut filters. In the present invention and this specification, unless otherwise specified, "transmittance" refers to external transmittance including reflection loss. Regarding near-infrared blocking capability, the wavelength at which the transmittance is 50% is the half-maximum (λ) wavelength, which is 550 nm or higher. T 50 can be used as an indicator, and the transmittance T1200 at a wavelength of 1200 nm can also be used as an indicator. Furthermore, glasses 1-8 can also exhibit high transmittance in the visible range. For transmittance in the visible range, the transmittance T400 at a wavelength of 400 nm can be used as an indicator, and the transmittance T600 at a wavelength of 600 nm can also be used as an indicator.

[0174] The transmittance characteristics of glass are determined by the following method. Glass samples are processed to have parallel and optically polished surfaces, and their external transmittance at wavelengths of 200–1200 nm is measured. The external transmittance includes the reflection loss of light rays at the sample surface. Let intensity A be the intensity of light rays incident perpendicularly on one optically polished plane, and intensity B be the intensity of light rays emitting from the other plane. Calculate the spectral transmittance B / A, including reflection loss. The wavelength at which the spectral transmittance is 50% above 550 nm is defined as λ at half maximum. T Let's assume the value is 50. The spectral transmittance at a wavelength of 400 nm is T400, the spectral transmittance at a wavelength of 600 nm is T600, and the spectral transmittance at a wavelength of 1200 nm is T1200. Furthermore, if the glass being measured is not of a thickness that can be converted, the thickness of the glass is denoted as d, and the transmittance at each wavelength λ is converted using the following formula A. Various converted values ​​can then be determined from the transmittance characteristics obtained through this conversion.

[0175] Equation A: T(λ)=(1-R(λ)) 2 × exp(log e ((T0(λ) / 100) / (1-R(λ)) 2 ) × d / d0) × 100

[0176] In equation A, T(λ): converted transmittance at wavelength λ (%), T0(λ): measured transmittance at wavelength λ (%), d: converted thickness (mm), d0: glass thickness (mm), R(λ) = ((n(λ)-1) / (n(λ)+1)) 2 The formula is expressed as the reflectance at wavelength λ, where n(λ) is the refractive index at wavelength λ. Here, we will calculate by considering n(λ) = 1.51680 and R(λ) = 0.042165 as constants.

[0177] A high T600 value, which represents transmittance in the red region, and a low T1200 value, which represents transmittance in the near-infrared region, could indicate that both improved transmittance in the visible region and improved near-infrared blocking capabilities have been achieved. Similarly, a high T400 value, which represents transmittance in the violet region, could also indicate improved transmittance in the visible region. From the above perspective, the preferred ranges for T400, T600, and T1200 are as follows: For T400, it is preferably 70% or higher, and more preferably 71% or higher, 72% or higher, 73% or higher, 74% or higher, 75% or higher, 76% or higher, 77% or higher, 78% or higher, 79% or higher, and 80% or higher, in that order. T400 can be, for example, 98% or lower, 97% or lower, or 96% or lower, but it is also preferable to have a T400 higher than the values ​​exemplified above, as a higher T400 means better visible light transmittance. For T600, it is preferable that it be 50% or more, and more preferably in the order of 55% or more, 56%, 57% or more, 58% or more, 59% or more, 60% or more, 61% or more, 62% or more, 63% or more, 64% or more, 65% or more, 66% or more, 67% or more, 68% or more, 69% or more, 70% or more, 71% or more, 72% or more, 73% or more, 74% or more, and 75% or more. T600 can be, for example, 90% or less, 85% or less, or 80% or less, but it is also preferable that it exceeds the values ​​exemplified above, as a higher T600 means better visible light transmittance. For T1200, it is preferably 30% or less, and more preferably 29% or less, 28% or less, 27% or less, 26% or less, 25% or less, 24% or less, 23% or less, 22% or less, 21% or less, 20% or less, 19% or less, 18% or less, 17% or less, 16% or less, 15% or less, 14% or less, 13% or less, 12% or less, 11% or less, 10% or less, 9% or less, 8% or less, 7% or less, 6% or less, 5% or less, 4% or less, 3% or less, 2% or less, and 1% or less. For the purpose of achieving compatibility with visible light transmittance, T1200 can be, for example, 1% or more, 3% or more, 5% or more, or 7% or more, but it is also preferable for T1200 to be lower than the values ​​exemplified above, as a lower T1200 means better near-infrared cut capability.

[0178] In one form, T1200 can have a β content of 1% or less.

[0179] β1 is calculated using the following formula B1. In formula B1, R is the O / P ratio. (Formula B1) β1 = 64 × R - 170

[0180] In one form, T1200 can also be less than or equal to the values ​​shown in β2, β3, β4, β5, and β6 in the following formulas B2 to B6 (unit: %). In the following formulas, R is the O / P ratio. Formula B2:β2=64×R-175 Equation B3: β3 = 64 × R - 180 Formula B4:β4=80×R-220 Formula B5:β5=80×R-224 Formula B6:β6=80×R-228

[0181] λ at half maximum is the wavelength at which the spectral transmittance is 50% above 550 nm. T 50 is preferably 600 nm or higher, and more preferably in the order of 610 nm or higher, 613 nm or higher, 615 nm or higher, 617 nm or higher, 620 nm or higher, 623 nm or higher, 625 nm or higher, and 628 nm or higher. T50 is preferably 650 nm or less, and more preferably in the order of 647 nm or less, 645 nm or less, 643 nm or less, 641 nm or less, 640 nm or less, 639 nm or less, and 638 nm or less. λ at half maximum is the wavelength at which the spectral transmittance is 50% at wavelengths of 550 nm or more. T Achieving a value of 50 with a glass thickness below a predetermined level is preferable from the viewpoint of balancing thinning the glass with improving near-infrared cutting ability. The glass thickness below a predetermined level is preferably 0.25 mm or less.

[0182] As will be described in detail later, in one form, glass 1 to 8 can be used as a near-infrared cut filter glass with a thickness of 0.25 mm or less.

[0183] Regarding glass 1 to 8, the following (a) to (h) are desirable transmittance characteristics for thinned near-infrared cut filter glass with a thickness of 0.25 mm or less. Glass 1 to 8 preferably satisfies one or more of the following (a) to (h), and may also satisfy two or more. By performing the glass composition adjustment described above, glass with desirable transmittance characteristics can be obtained.

[0184] (a) wavelength λ at which the external transmittance including reflection loss is 50% at wavelengths of 550 nm or higher T The glass thickness at which 50 corresponds to 633nm is 0.25mm or less. At the above thickness, the external transmittance T600, including reflection loss at a wavelength of 600 nm, is 50% or more, and the external transmittance T1200, including reflection loss at a wavelength of 1200 nm, is 30% or less.

[0185] Regarding (a) above, the wavelength λ at which the external transmittance including reflection loss is 50% at wavelengths of 550 nm or higher is... T The glass thickness at which 50 corresponds to 633 nm is 0.25 mm or less, and it is more preferable that the thickness of the near-infrared cut filter falls within the thickness range described later. This also applies to (b), (e), and (f) below.

[0186] (b) The thickness of the glass is 0.25 mm or less, such that the wavelength at which the external transmittance including reflection loss is 50% at wavelengths of 550 nm or higher is 633 nm. At the above thickness, the external transmittance T600, including reflection loss at a wavelength of 600 nm, is 50% or more, and the external transmittance T1200, including reflection loss at a wavelength of 1200 nm, is β1% or less. 1 This value is calculated from the following formula B1. In formula B1, R is the O / P ratio of glass 1 to 8.

[0187] (Formula B1) β1 = 64 × R - 170

[0188] As mentioned earlier, T1200 can also have β2% or less, β3% or less, β4% or less, β5% or less, or β6% or less.

[0189] (c) The wavelength λ at which the external transmittance, including reflection loss, is 50% is calculated as the transmittance characteristic for a thickness of 0.16 mm. T The value 50 is in the range of 600nm to 650nm, the external transmittance T1200 including reflection loss at a wavelength of 1200nm is 30% or less, and the external transmittance T400 including reflection loss at a wavelength of 400nm is 70% or more.

[0190] (d) The wavelength λ at which the external transmittance, including reflection loss, is 50% as a transmittance characteristic calculated for a thickness of 0.21 mm. T The value 50 is in the range of 600nm to 650nm, the external transmittance T1200 including reflection loss at a wavelength of 1200nm is 25% or less, and the external transmittance T400 including reflection loss at a wavelength of 400nm is 70% or more.

[0191] (e) The thickness of the glass is 0.25 mm or less such that the wavelength at which the external transmittance including reflection loss is 50% at wavelengths of 550 nm or higher is 645 nm. At the above thickness, the external transmittance T600, including reflection loss at a wavelength of 600 nm, is 50% or more, and the external transmittance T1200, including reflection loss at a wavelength of 1200 nm, is 30% or less.

[0192] (f) The wavelength λ at which the external transmittance, including reflection loss, is 50% at wavelengths of 550 nm or higher T The glass thickness at which 50 corresponds to 645nm is 0.25mm or less. At the above thickness, the external transmittance T600, including reflection loss at a wavelength of 600 nm, is 50% or more, and the external transmittance T1200, including reflection loss at a wavelength of 1200 nm, is β1% or less, where β1 is the value calculated by Equation 4 described above.

[0193] (g) The wavelength λ at which the external transmittance, including reflection loss, is 50% is calculated as the transmittance characteristic for a thickness of 0.23 mm. T The value 50 is in the range of 600nm to 650nm, the external transmittance T1200 including reflection loss at a wavelength of 1200nm is 18% or less, and the external transmittance T400 including reflection loss at a wavelength of 400nm is 70% or more.

[0194] (h) The wavelength λ at which the external transmittance, including reflection loss, is 50% is calculated as the transmittance characteristic for a thickness of 0.25 mm. T The value 50 is in the range of 600nm to 650nm, the external transmittance T1200 including reflection loss at a wavelength of 1200nm is 16% or less, and the external transmittance T400 including reflection loss at a wavelength of 400nm is 70% or more.

[0195] (weather resistance) Glasses 1 to 8, having the compositions described above, can exhibit excellent weather resistance. Weather resistance can also be indicated by the haze value measured by a haze meter. Examples of glass with excellent weather resistance include glass with a haze value of 15% or less, measured by a haze meter specified in JIS K 7136:2000 after storage for 90 minutes under constant temperature and humidity conditions of 85°C and 85% relative humidity. Such a haze value can be 0% or 0% or more, preferably 10% or less, more preferably 5% or less, and even more preferably 1% or less. Furthermore, regarding weather resistance, in one form, glass that is less prone to deliquescence can be said to have superior weather resistance. An example of a method for evaluating deliquescence is the method described in the examples below.

[0196] (Glass transition temperature Tg, temperature Tm at which the endothermic reaction due to melting converges) The glass transition temperatures of glasses 1 to 8 are not particularly limited, but from the viewpoint of improving the transmittance of the glass in the short wavelength range by improving the meltability of the glass, and from the viewpoint of reducing the burden on the annealing furnace and molding equipment, the Tg is preferably 480°C or lower, and more preferably in the order of 450°C or lower, 430°C or lower, 420°C or lower, 410°C or lower, 400°C or lower, and 370°C or lower. From the viewpoint of improving the chemical durability and / or heat resistance of the glass, the Tg is preferably 250°C or higher, and more preferably in the order of 260°C or higher, 270°C or higher, 280°C or higher, 290°C or higher, and 300°C or higher.

[0197] The Tg value of glass can be controlled by adjusting the content and total content of Li2O, Na2O, K2O, ZnO, MgO, and Al2O3.

[0198] The temperature Tm at which the endothermic reaction due to the melting of glass 1 to 8 converges is not particularly limited, but the lower the Tm, the better the meltability, and the less likely devitrification is to occur in the glass even when molding with higher viscosity. Furthermore, the better the meltability, the more likely it is to be possible to increase the transmittance of the glass in the short-wavelength visible range. From these viewpoints, Tm is preferably 890°C or lower, and more preferably in the order of 880°C or lower, 870°C or lower, 860°C or lower, 850°C or lower, 840°C or lower, 830°C or lower, 820°C or lower, 810°C or lower, 800°C or lower, 790°C or lower, 780°C or lower, 770°C or lower, 760°C or lower, 750°C or lower, 740°C or lower, 730°C or lower, 720°C or lower, 710°C or lower, 700°C or lower, 690°C or lower, 680°C or lower, 670°C or lower, 660°C or lower, and 650°C or lower. While there is no particular lower limit to Tm, if Tm is too low, the weather resistance of the glass tends to decrease. Therefore, Tm can also be 500°C or higher, 550°C or higher, 580°C or higher, 600°C or higher, 620°C or higher, or 640°C or higher.

[0199] The Tm value of glass can be controlled by adjusting the content and total content of Li2O, Na2O, K2O, ZnO, MgO, Al2O3, and their combined content.

[0200] For example, using a differential scanning calorimetry analyzer (DSC8270) manufactured by Rigaku, the glass transition temperature Tg and the temperature Tm at which the endothermic reaction due to melting converges can be measured at a heating rate of 10°C / min. The measurement temperature range can be from room temperature to 1050°C.

[0201] (specific gravity) The lightness of the near-infrared cut filter is desirable because it leads to a reduction in the weight of the elements and devices into which the filter is incorporated. From this point of view, the specific gravity of glass 1 to 8 is preferably 3.80 or less, and is more preferably 3.40 or less, 3.35 or less, 3.30 or less, 3.25 or less, 3.20 or less, 3.15 or less, 3.10 or less, 3.05 or less, 3.00 or less, 2.95 or less, 2.90 or less, 2.85 or less, 2.80 or less, 2.75 or less, 2.70 or less, 2.65 or less, and 2.60 or less, in that order. The specific gravity can be, for example, 2.00 or higher or 2.40 or higher, but from the above viewpoint, a lower specific gravity is preferable, so it is also preferable that it be below the values ​​exemplified here. The unit of specific gravity is "g / cc".

[0202] (Molar volume) While there are no particular limitations on the molar volume (M / D) of glass, a smaller molar volume is preferable from the viewpoint of increasing the amount of CuO per unit volume to enhance near-infrared absorption capacity. The molar volume can be reduced by substituting P2O5, La2O3, Y2O3, Gd2O3, BaO, K2O, etc. with Li2O, and can be reduced slightly by substituting Al2O3, CuO, Na2O with Li2O. On the other hand, substituting CaO, ZnO, and SrO with Li2O does not significantly change the molar volume, while substituting MgO with Li2O tends to increase the molar volume. The molar volume of glass can be adjusted by adjusting the glass composition while taking these trends into consideration. The molar volume is preferably 45 cc / mol or less, and is more preferably 43 cc / mol or less, 42 cc / mol or less, 41 cc / mol or less, 40 cc / mol or less, 39.5 cc / mol or less, 39.0 cc / mol or less, 38.5 cc / mol or less, 38.0 cc / mol or less, and 37.5 cc / mol or less, in that order. On the other hand, from the standpoint of maintaining the weather resistance of the glass, the molar volume can be increased, and from this standpoint, the molar volume of glass 1 to 6 can be 34.0 cc / mol or more, and can also be 35.0 cc / mol or more, 36.0 cc / mol or more, 36.5 cc / mol or more, 37.0 cc / mol or more, 37.5 cc / mol or more, 38.0 mol or more, 38.5 cc / mol or more, 39.0 cc / mol or more, and 39.5 cc / mol or more.

[0203] <Method of manufacturing glass> The above-mentioned glass can be obtained by blending, melting, and shaping various glass raw materials. For details on the manufacturing method, please refer to the description below.

[0204] The above-mentioned near-infrared absorbing glass is suitable as glass for near-infrared cut filters. Furthermore, the above-mentioned near-infrared absorbing glass can be applied to optical elements other than near-infrared cut filters (such as lenses), and can be applied to various other glass products, and can be modified in various ways.

[0205] [Near-infrared cut filter] One aspect of the present invention relates to a near-infrared cut filter (hereinafter also simply referred to as "filter") made of the above-mentioned near-infrared absorbing glass.

[0206] The glass components of the above filter are as described previously.

[0207] The following describes a specific example of the method for manufacturing the above-mentioned filter. However, the following manufacturing method is illustrative and does not limit the present invention.

[0208] Molten glass is prepared by weighing and mixing glass raw materials such as phosphates, oxides, carbonates, nitrates, sulfates, and fluorides to achieve the desired composition. The mixture is then melted in a melting vessel, such as a platinum crucible, at a temperature of, for example, 800°C to 1100°C. A platinum lid may be used to suppress the volatilization of volatile components. The melting can be carried out in the atmosphere, and to suppress changes in the valence of Cu, an oxygen atmosphere can be used, or oxygen can be bubbled into the molten glass. The molten glass becomes homogenized molten glass with reduced bubbles (preferably bubble-free) after stirring and clarification. Alternatively, the glass can be clarified at 900°C to 1100°C, and then cooled to 800°C to 1000°C to promote oxidation before obtaining the glass. However, it is undesirable for the melting temperature or clarification temperature to remain below the liquidus temperature of the glass for an extended period.

[0209] After stirring and clarifying the molten glass, the glass is poured out, slowly cooled, and then molded into the desired shape. When pouring out the glass, it is preferable to lower the temperature to near the liquidus temperature to increase the viscosity of the glass, as this reduces convection in the poured glass and minimizes striation formation. The slow cooling rate can be selected from between -50°C / hr and -1°C / hr, and -30°C / hr or -10°C / hr can also be selected.

[0210] Known methods such as casting, pipe pouring, rolling, and pressing can be used for forming the glass. The formed glass is transferred to an annealing furnace that has been preheated to near the transition point of the glass, and slowly cooled to room temperature. In this way, a near-infrared cut filter can be manufactured.

[0211] An example of a molding method is described below. A mold is prepared, consisting of a flat, horizontal bottom surface, a pair of side walls parallel to each other and flanking the bottom surface, and a weir plate that closes one of the openings located between the pair of side walls. Molten glass, homogenized from a platinum alloy pipe, is poured into this mold at a constant flow rate. The poured molten glass spreads within the mold and is formed into a glass plate of a certain width, restricted by the pair of side walls. The formed glass plate is continuously pulled out from the opening of the mold. By appropriately setting the molding conditions such as the shape and dimensions of the mold and the flow rate of the molten glass, large and thick glass blocks can be formed. The formed glass body is transferred to an annealing furnace that has been preheated to near the glass transition temperature and slowly cooled to room temperature. The glass body, whose distortion has been removed by slow cooling, is subjected to machining such as slicing, grinding, and polishing. In this way, near-infrared cut filters in shapes such as plates and lenses, depending on the application, can be obtained. Alternatively, a method can be used in which a preform made of the above-mentioned glass is formed, and this preform is heated, softened, and then press-formed (especially a precision press-forming method that press-forms the final product without performing machining such as grinding or polishing on the optical functional surface). An optical multilayer film may be formed on the surface of the filter as needed.

[0212] The above-mentioned near-infrared cut filter combines excellent near-infrared cutting capability with high transmittance in the visible range. Such a near-infrared cut filter allows for effective color sensitivity correction of semiconductor image sensors.

[0213] Furthermore, the above-mentioned near-infrared cut filter can be applied to an imaging device by combining it with a semiconductor image sensor. A semiconductor image sensor has a semiconductor image element such as a CCD or CMOS mounted inside a package, and the light-receiving part is covered with a light-transmitting material. The light-transmitting material can also be used as the near-infrared cut filter, or the light-transmitting material can be a separate component from the near-infrared cut filter.

[0214] The above imaging device may also include an optical element such as a lens or prism for forming an image of the subject on the light-receiving surface of the semiconductor image sensor.

[0215] Furthermore, the above-mentioned near-infrared cut filter enables good color sensitivity correction, making it possible to provide an imaging device capable of obtaining images with excellent image quality.

[0216] The above-mentioned near-infrared cut filter can, in one embodiment, be a near-infrared cut filter with a thickness of 0.25 mm or less. In recent years, with the advent of smartphones, there has been a noticeable trend towards reducing the thickness of image sensors in cameras, and accordingly, there is a demand for near-infrared cut filters that can perform well with a thinner thickness. The above-mentioned near-infrared cut filter is suitable as such a near-infrared cut filter. The thickness of the above-mentioned near-infrared cut filter can be 0.24 mm or less, 0.23 mm or less, 0.22 mm or less, 0.21 mm or less, 0.20 mm or less, 0.19 mm or less, 0.18 mm or less, 0.17 mm or less, 0.16 mm or less, 0.15 mm or less, 0.14 mm or less, 0.13 mm or less, or 0.12 mm or less. The thickness of the above-mentioned near-infrared cut filter can be, for example, 0.21 mm or 0.11 mm. Furthermore, the thickness of the above-mentioned near-infrared cut filter can be, for example, 0.50 mm or more, but is not limited to this. In the present invention and this specification, "thickness" refers to the thickness of the sample in the area where transmittance is to be measured, and can be measured using a thickness gauge, micrometer, or the like. For example, the thickness may be measured at approximately the center of the position through which the transmitted light passes, or the thickness may be measured at multiple points within the spot of transmitted light and the average value may be taken.

[0217] For the transmittance characteristics of the above near-infrared cut filter, please refer to the previous description regarding glass 1 to 8. Similarly, for the physical properties of the above near-infrared cut filter, please refer to the previous description regarding glass 1 to 8. [Examples]

[0218] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to the embodiments described herein.

[0219] [Examples 1-39, Comparative Examples 1-3] As glass raw materials, phosphates, fluorides, carbonates, nitrates, oxides, etc. were weighed and mixed to obtain 150g to 300g of glass with the composition shown in Table 1. These were placed in a platinum or quartz crucible and melted at 800°C to 1000°C for 80 to 100 minutes. After stirring to degas and homogenize, the mixture was poured into a preheated mold and molded into the desired shape. The resulting glass molded body was transferred to an annealing furnace heated to near its glass transition temperature and slowly cooled to room temperature. Test pieces were cut from the obtained glass, both sides were mirror-polished to a thickness of approximately 0.2 mm, and then various evaluations were performed using the following methods. Comparative Example 1 is a glass having the composition of Example 5 in Japanese Patent Publication No. 2019-38719 (Patent Document 1). Comparative Example 2 is a glass having the composition of Example 5 in CN110255897 (Patent Document 2). Comparative Example 3 is a glass having the composition of Example 10 in Japanese Patent Publication No. 55-3336 (Patent Document 3).

[0220] [Evaluation Method] <Transmittance characteristics> The transmittance of each test piece at wavelengths of 200 to 1200 nm was measured using a spectrophotometer. From the measurement results, the half-value (in nm), T400, T600, and T1200 (in %) were calculated as values ​​converted to half-value at 645 nm, half-value at 633 nm, thicknesses of 0.16 mm, 0.21 mm, 0.23 mm, and 0.25 mm. Furthermore, the transmittance characteristics of each test piece were determined from the measurement results obtained by measuring the transmittance at wavelengths of 200 to 1200 nm using a spectrophotometer: For thicknesses of 0.25 mm or less, the external transmittance at 400 nm and 1200 nm is calculated by converting to a thickness at which the external transmittance is 50% at wavelengths of 620-650 nm. For thicknesses of 0.23 mm or less, the external transmittance at wavelengths of 625-650 nm is converted to a thickness where the external transmittance is 50%, and the external transmittance at wavelengths of 400 nm and 1200 nm are calculated. They sought it.

[0221] <Specific gravity> The specific gravity was measured using the Archimedes method.

[0222] <α (100~300℃)> A cylindrical glass sample with a diameter of 5 mm and a length of 20 mm was prepared, and α (100-300°C) was measured using a Bruker axs TMA4000s thermomechanical analyzer. The sample heating rate during measurement was 4°C / min.

[0223] <Molar volume> The molar volume was calculated from the measured specific gravity value using the method described above.

[0224] <Weather resistance evaluation> Each test piece was kept in a constant temperature and humidity chamber at 85°C and 85% relative humidity for 90 minutes. Afterward, the haze of the test piece was quantitatively evaluated as a haze value using a haze meter specified in JIS K 7136:2000. Deliquescence was assessed by observing the polished surface and rough side surface condition of each test piece after keeping them in a constant temperature and humidity chamber at 85°C and 85% relative humidity for 90 minutes, according to the following evaluation criteria. ○: No "stickiness on the polished surface," "changes in light transmittance," or "color changes (darkening) due to moisture content on the rough-ground side surface" were observed. ×: One or more of the following were observed: "stickiness on the polished surface," "change in light transmittance," and "color change (darkening) due to moisture content on the rough-ground side surface."

[0225] The results are shown in the table below.

[0226] [Table 1-1]

[0227] Table 1-2

[0228] Table 1-3

[0229] Table 1-4

[0230] Table 2-1

[0231] Table 2-2

[0232] Table 2-3

[0233] Table 2-4

[0234] Table 3-1

[0235] Table 3-2

[0236] Table 3-3

[0237] Table 3-4

[0238] Table 4-1

[0239] Table 4-2

[0240] Table 4-3

[0241] Table 4-4

[0242] Table 5-1

[0243] Table 5-2

[0244] Table 5-3

[0245] Table 5-4

[0246] Table 6

[0247] From the results shown in the table above, it can be confirmed that each of the above-described examples exhibits high transmittance in the visible region (purple to red region) even when thinned, has excellent near-infrared blocking ability, and suppresses the deterioration of weather resistance. Comparative Example 1 has a Cu concentration of less than α1% and less than α2%. In the glass of Comparative Example 1, the glass cannot be thinned in order to obtain the desired transmittance characteristics. The glass in Comparative Example 2 had a high T1200 at the reduced thickness. The glass in Comparative Example 3 has a large α (100-300°C), and as mentioned earlier, it is prone to breaking. Furthermore, the glasses of Comparative Examples 1-3 were prone to deliquescent glass because the total content of Li2O, Na2O, and K2O (Li2O + Na2O + K2O) exceeded 15 mol%.

[0248] Each of the above embodiments' glass materials was processed into flat plates of three different thicknesses: 0.21 mm, 0.16 mm, and 0.11 mm, to produce near-infrared cut filters. The main surface of the near-infrared cut filter is an optically polished surface. In this way, a near-infrared cut filter with excellent near-infrared cutting ability and excellent weather resistance was obtained. Note that a coating such as an anti-reflective film may be formed on the surface of the near-infrared cut filter.

[0249] [Examples 1-1 to 1-4] Except for the Sb2O3 content indicated by the external division being 0.1% by mass (Example 1-1), 0.5% by mass (Example 1-2), 1.0% by mass (Example 1-3), or 1.5% by mass (Example 1-4), 150g to 300g of glass with the same composition as Example 1 described above was obtained by weighing and mixing phosphates, fluorides, carbonates, nitrates, oxides, etc., as glass raw materials, placing them in a platinum or quartz crucible, melting them at 800°C to 1000°C for 80 to 100 minutes, stirring to degas and homogenize, then pouring the mixture into a preheated mold and molding it into a predetermined shape. The obtained glass molded body was transferred to an annealing furnace heated to near its glass transition temperature and slowly cooled to room temperature. Test pieces were cut from the obtained glass, and both sides were mirror-polished to a thickness of approximately 0.20 mm to 0.21 mm. Then, the transmittance characteristics of each test piece were measured using the method described above, and T400 (unit: %) was determined as the external transmittance at a wavelength of 400 nm at a plate thickness where the external transmittance at a wavelength of 633 nm was 50%. This T400 was also determined for the glass of Example 1 (without Sb2O3 addition). Figure 2 shows photographs of the appearance of the glass from Examples 1-1 to 1-4. Figure 3 shows graphs plotting the T400 value against the Sb2O3 content for the glass from Example 1 and Examples 1-1 to 1-4.

[0250] [Examples 4-1 to 4-4] Except for the Sb2O3 content indicated by the external division being 0.1% by mass (Example 4-1), 0.5% by mass (Example 4-2), 1.0% by mass (Example 4-3), or 1.5% by mass (Example 4-4), 150g to 300g of glass with the same composition as Example 4 described above was obtained by weighing and mixing phosphates, fluorides, carbonates, nitrates, oxides, etc., as glass raw materials, placing them in a platinum or quartz crucible, melting them at 800°C to 1000°C for 80 to 100 minutes, stirring to degas and homogenize, then pouring the mixture into a preheated mold and shaping it into a predetermined form. The resulting glass molded body was transferred to an annealing furnace heated to near its glass transition temperature and slowly cooled to room temperature. Test pieces were cut from the obtained glass, and both sides were mirror-polished to a thickness of approximately 0.20 mm. Then, the transmittance characteristics of each test piece were measured using the method described above, and T400 (unit: %) was determined as the external transmittance at a wavelength of 400 nm at a plate thickness where the external transmittance at a wavelength of 633 nm was 50%. This T400 was also determined for the glass of Example 4 (without Sb2O3 addition). Figure 4 shows photographs of the glass appearance of Examples 4-1 to 4-4. 1 Figure 5 shows a graph plotting the T400 value against the Sb2O3 content for the ~4-4 glass.

[0251] [Examples 25-1 to 25-4] Except for the Sb2O3 content indicated by the external division being 0.1% by mass (Example 25-1), 0.5% by mass (Example 25-2), 1.0% by mass (Example 25-3), or 1.5% by mass (Example 25-4), 150g to 300g of glass with the same composition as Example 25 described above was obtained by weighing and mixing phosphates, fluorides, carbonates, nitrates, oxides, etc., as glass raw materials, placing them in a platinum or quartz crucible, melting them at 800°C to 1000°C for 80 to 100 minutes, stirring to degas and homogenize, then pouring the mixture into a preheated mold and shaping it into a predetermined form. The resulting glass molded body was transferred to an annealing furnace heated to near its glass transition temperature and slowly cooled to room temperature. Test pieces were cut from the obtained glass, and both sides were mirror-polished to a thickness of approximately 0.21 mm to 0.22 mm. Then, the transmittance characteristics of each test piece were measured using the method described above, and T400 (unit: %) was determined as the external transmittance at a wavelength of 400 nm at a plate thickness where the external transmittance at a wavelength of 633 nm was 50%. This T400 was also determined for the glass of Example 25 (without Sb2O3 addition). Photographs of the glass from Examples 25-1 to 25-4 are shown in Figure 6. Figure 7 shows graphs plotting the T400 value against the Sb2O3 content for the glass from Examples 25 and 25-1 to 25-4.

[0252] The results shown in Figures 2 to 7 confirm that adding Sb2O3 to glass is preferable from the viewpoint of promoting glass oxidation and increasing the transmittance in the visible range. In one embodiment, the Sb2O3 content as indicated by external division can be 0.1% by mass or more, 0.5% by mass or more, 1.0% by mass or more, or 1.5% by mass or more.

[0253] Finally, we will summarize each of the aforementioned aspects.

[0254] According to one embodiment, the glasses 1 to 6 described in detail above are provided.

[0255] In one embodiment, glass 1 to 6 can be a glass in which the ratio of BaO content to Li2O content (BaO / Li2O) in the glass composition expressed in mol% on an oxide basis is 1.0 or more, and satisfies one or more of the following (1) to (4). (1) The ratio of the total content of CaO, SrO, and ZnO to the BaO content ((CaO+SrO+ZnO) / BaO) is 0.02 or higher. (2) The ratio of the total content of CaO, SrO, and ZnO to the total content of MgO and BaO ((CaO + SrO + ZnO) / (MgO + BaO)) but 0.02 or higher, (3) The ratio of the total content of K2O + CaO + SrO to the BaO content ((K2O + CaO + SrO) / BaO) is 0.12 or more. (4) The ratio of the total content of K2O, CaO, SrO, and ZnO to the total content of MgO and BaO ((K2O+CaO+SrO+ZnO) / (MgO+BaO)) is 0.12 or greater.

[0256] In one embodiment, the total content of oxides of the above-mentioned major cations in the glass composition expressed in molar percentages based on the oxides of glass 1 to 6 can be 90.0% or more.

[0257] According to one embodiment, the glass 7 described in detail above is provided.

[0258] In one form, glass 7 can be glass that satisfies one or more of the following conditions (1) to (4). (1) The ratio of the total content of CaO, SrO, and ZnO to the BaO content ((CaO+SrO+ZnO) / BaO) is 0.02 or higher. (2) The ratio of the total content of CaO, SrO, and ZnO to the total content of MgO and BaO ((CaO + SrO + ZnO) / (MgO + BaO)) but 0.02 or higher, (3) The ratio of the total content of K2O + CaO + SrO to the BaO content ((K2O + CaO + SrO) / BaO) is 0.12 or more. (4) The ratio of the total content of K2O, CaO, SrO, and ZnO to the total content of MgO and BaO ((K2O+CaO+SrO+ZnO) / (MgO+BaO)) is 0.12 or greater.

[0259] According to one embodiment, the glass 8 described in detail above is provided.

[0260] In one embodiment, the glass 8 has a thickness of 0.23 mm or less, and when converted to a thickness at which the external transmittance is 50% at wavelengths of 625 to 650 nm, it has transmittance characteristics such as an external transmittance of 80% or more at wavelengths of 400 nm and an external transmittance of 5% or less at wavelengths of 1200 nm, and an average coefficient of linear expansion of 130 × 10⁻¹⁰ at 100 to 300°C. -7 It can be glass with a temperature of / K or less.

[0261] In one embodiment, glass 1-8 has a wavelength of 550 nm or higher at which the external transmittance, including reflection loss, is 50% (half-maximum latitude). T The glass can be such that the thickness of the glass where 50 corresponds to 633 nm is 0.25 mm or less, and at the above thickness, the external transmittance T600 including reflection loss at a wavelength of 600 nm is 50% or more, and the external transmittance T1200 including reflection loss at a wavelength of 1200 nm is 30% or less.

[0262] In one embodiment, glass 1-8 has a wavelength of 550 nm or higher at which the external transmittance, including reflection loss, is 50% (half-maximum latitude). T The glass can be such that the thickness of the glass at which 50 corresponds to 633 nm is 0.25 mm or less, and at the above thickness, the external transmittance T600 including reflection loss at a wavelength of 600 nm is 50% or more, and the external transmittance T1200 including reflection loss at a wavelength of 1200 nm is β1% or less. β1 is as described above.

[0263] In one embodiment, glass 1-8 has a transmittance characteristic equivalent to a thickness of 0.16 mm, and the wavelength at which the external transmittance including reflection loss is 50% is the wavelength at which half maximum (λ). TThe glass can be such that the value 50 is in the range of 600nm to 650nm, the external transmittance T1200 including reflection loss at a wavelength of 1200nm is 30% or less, and the external transmittance T400 including reflection loss at a wavelength of 400nm is 70% or more.

[0264] In one embodiment, glass 1-8 has a transmittance characteristic equivalent to a thickness of 0.21 mm, and the wavelength at which the external transmittance including reflection loss is 50% is the wavelength at which half-maximum (λ). T The glass can be such that the value 50 is in the range of 600nm to 650nm, the external transmittance T1200 including reflection loss at a wavelength of 1200nm is 25% or less, and the external transmittance T400 including reflection loss at a wavelength of 400nm is 70% or more.

[0265] In one embodiment, glass 1-8 has a wavelength of 550 nm or higher at which the external transmittance, including reflection loss, is 50% (half-maximum latitude). T The glass can be such that the thickness of the glass at which 50 corresponds to 645 nm is 0.25 mm or less, and at the above thickness, the external transmittance T600 including reflection loss at a wavelength of 600 nm is 50% or more, and the external transmittance T1200 including reflection loss at a wavelength of 1200 nm is 30% or less.

[0266] In one embodiment, glass 1-8 has a wavelength of 550 nm or higher at which the external transmittance, including reflection loss, is 50% (half-maximum latitude). T The glass can be such that the thickness of the glass at which 50 corresponds to 645 nm is 0.25 mm or less, and at the above thickness, the external transmittance T600 including reflection loss at a wavelength of 600 nm is 50% or more, and the external transmittance T1200 including reflection loss at a wavelength of 1200 nm is β1% or less. β1 is as described above.

[0267] According to one embodiment, a near-infrared cut filter made of the above-mentioned near-infrared absorbing glass is provided.

[0268] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the claims rather than the foregoing description, and all modifications within the meaning and scope of equivalents of the claims are intended. For example, by performing the compositional adjustments described in the specification on the glass composition exemplified above, a near-infrared absorbing glass according to one aspect of the present invention can be obtained. Furthermore, it is certainly possible to arbitrarily combine two or more items described as examples or preferred scopes in the specification.

Claims

1. It contains four or more major cations selected from the group consisting of P ions, Li ions, Cu ions, Al ions, Ba ions, Sr ions, Ca ions, Mg ions, Zn ions, K ions, Na ions, La ions, Gd ions, and Y ions. It contains P ions, Ba ions, and Cu ions as essential cations. In the glass composition expressed in anion percentage, the O ion content is 90.0 anion% or more. In the glass composition expressed in atomic percent, the ratio of O ions to P ions (O ions / P ions) is 3.15 or less. In glass composition expressed in mol% based on oxides, The total content of oxides of the aforementioned major cations is 90.0% or more. The BaO content is 10.0 mol% or more. B ２ O ３ and SiO ２ Total content (B ２ O ３ +SiO ２ ) is 3.0 mol% or less, MgO and Al ２ O ３ The total content thereof (MgO + Al ２ O ３ ) is 8.0 mol% or less, Li ２ O, Na ２ O and K ２ Total O content (Li ２ O + Na ２ O+K ２ O) is 15 mol% or less, CuO content is α １ It is % or more, α １ The formula is as follows: (Formula 1) a １ = 70400×exp(-2.855×R) This is a value calculated by, In the above formula 1, R is the aforementioned ratio (O ions / P ions), Sb ２ O ３ The content is less than 2.0% by mass when expressed as an external percentage, and Near-infrared absorbing glass that does not contain As as a glass component.

2. It contains four or more major cations selected from the group consisting of P ions, Li ions, Cu ions, Al ions, Ba ions, Sr ions, Ca ions, Mg ions, Zn ions, K ions, Na ions, La ions, Gd ions, and Y ions. It contains P ions, Ba ions, and Cu ions as essential cations. In the glass composition expressed in anion percentage, the O ion content is 90.0 anion% or more. In the glass composition expressed in atomic percent, the ratio of O ions to P ions (O ions / P ions) is 3.15 or less. In glass composition expressed in mol% based on oxides, The total content of oxides of the aforementioned major cations is 90.0% or more. The BaO content is 10.0 mol% or more. B ２ O ３ and SiO ２ Total content (B ２ O ３ +SiO ２ ) is 3.0 mol% or less, MgO and Al ２ O ３ Total content (MgO + Al ２ O ３ ) is 8.0 mol% or less, Li ２ O, Na ２ O and K ２ Total O content (Li ２ O + Na ２ O+K ２ O) is 15 mol% or less, Formula 2 below: (Formula 2) C-3200×exp(-2.278×R)≧0 Satisfying the conditions, In the above formula 2, C is the CuO content per molar volume of glass (unit: millimoles / cc), R is the aforementioned ratio (O ions / P ions), Sb ２ O ３ The content is less than 2.0% by mass when expressed as an external percentage, and Near-infrared absorbing glass that does not contain As as a glass component.

3. It contains four or more major cations selected from the group consisting of P ions, Li ions, Cu ions, Al ions, Ba ions, Sr ions, Ca ions, Mg ions, Zn ions, K ions, Na ions, La ions, Gd ions, and Y ions. It contains P ions, Ba ions, and Cu ions as essential cations. In the glass composition expressed in anion percentage, the O ion content is 90.0 anion% or more. In the glass composition expressed in atomic percent, the ratio of O ions to P ions (O ions / P ions) is 3.15 or less. In glass composition expressed in mol% based on oxides, The total content of oxides of the aforementioned major cations is 90.0% or more. The BaO content is 10.0 mol% or more. B ２ O ３ and SiO ２ Total content (B ２ O ３ +SiO ２ ) is 3.0 mol% or less, MgO and Al ２ O ３ Total content (MgO + Al ２ O ３ ) is 8.0 mol% or less, Li ２ O, Na ２ O and K ２ Total O content (Li ２ O + Na ２ O+K ２ O) is 15 mol% or less, Formula 3 below: (Formula 3) A １ ={O(P)-O(others)}×Cu A is calculated by １ The number is 2500 or more, In the above formula 3, O(P) indicates the amount of oxygen constituting the oxide of P ions in the oxide-based glass composition. O(others) represents the amount of oxygen obtained by subtracting O(P) from the amount of oxygen constituting the oxide of the main cation in the oxide-based glass composition. Cu represents the CuO content in molar percentage in the oxide-based glass composition. Sb ２ O ３ The content is less than 2.0% by mass when expressed as an external percentage, and Near-infrared absorbing glass that does not contain As as a glass component.

4. It contains four or more major cations selected from the group consisting of P ions, Li ions, Cu ions, Al ions, Ba ions, Sr ions, Ca ions, Mg ions, Zn ions, K ions, Na ions, La ions, Gd ions, and Y ions. It contains P ions, Ba ions, and Cu ions as essential cations. In the glass composition expressed in anion percentage, the O ion content is 90.0 anion% or more. In the glass composition expressed in atomic percent, the ratio of O ions to P ions (O ions / P ions) is 3.15 or less. In glass composition expressed in mol% based on oxides, The total content of oxides of the aforementioned major cations is 90.0% or more. The BaO content is 10.0 mol% or more. B ２ O ３ and SiO ２ Total content (B ２ O ３ +SiO ２ ) is 3.0 mol% or less, MgO and Al ２ O ３ Total content (MgO + Al ２ O ３ ) is 8.0 mol% or less, Li ２ O, Na ２ O and K ２ Total O content (Li ２ O + Na ２ O+K ２ O) is 15 mol% or less, Formula 4 below: (Formula 4) A ２ ={O(P)-O(others)}×C A is calculated by ２ The number is 700 or more, In the above formula 4, C is the CuO content per molar volume of glass (unit: millimoles / cc), O(P) indicates the amount of oxygen constituting the oxide of P ions in the oxide-based glass composition. O(others) represents the amount of oxygen obtained by subtracting O(P) from the amount of oxygen constituting the oxide of the main cation in the oxide-based glass composition. Sb ２ O ３ The content is less than 2.0% by mass when expressed as an external percentage, and Near-infrared absorbing glass that does not contain As as a glass component.

5. It contains four or more major cations selected from the group consisting of P ions, Li ions, Cu ions, Al ions, Ba ions, Sr ions, Ca ions, Mg ions, Zn ions, K ions, Na ions, La ions, Gd ions, and Y ions. It contains P ions, Ba ions, and Cu ions as essential cations. In the glass composition expressed in anion percentage, the O ion content is 90.0 anion% or more. In the glass composition expressed in atomic percent, the ratio of O ions to P ions (O ions / P ions) is 3.15 or less. In glass composition expressed in mol% based on oxides, The total content of oxides of the aforementioned major cations is 90.0% or more. The BaO content is 10.0 mol% or more. B ２ O ３ and SiO ２ Total content (B ２ O ３ +SiO ２ ) is 3.0 mol% or less, MgO and Al ２ O ３ Total content (MgO + Al ２ O ３ ) is 8.0 mol% or less, Li ２ O, Na ２ O and K ２ The total content of O (Li ２ O + Na ２ O + K ２ O) is 15 mol% or less, CuO content is α ２ It is % or more, α ２ is represented by the following formula 5: (Formula 5) a ２ = 76522×exp(-2.855×R) This is a value calculated by, In the above formula 5, R is the aforementioned ratio (O ions / P ions), Sb ２ O ３ The content is less than 2.0% by mass when expressed as an external percentage, and Near-infrared absorbing glass that does not contain As as a glass component.

6. It contains four or more major cations selected from the group consisting of P ions, Li ions, Cu ions, Al ions, Ba ions, Sr ions, Ca ions, Mg ions, Zn ions, K ions, Na ions, La ions, Gd ions, and Y ions. It contains P ions, Ba ions, and Cu ions as essential cations. In the glass composition expressed in anion percentage, the O ion content is 90.0 anion% or more. In the glass composition expressed in atomic percent, the ratio of O ions to P ions (O ions / P ions) is 3.15 or less. In glass composition expressed in mol% based on oxides, The total content of oxides of the aforementioned major cations is 90.0% or more. The BaO content is 10.0 mol% or more. B ２ O ３ and SiO ２ Total content (B ２ O ３ +SiO ２ ) is 3.0 mol% or less, MgO and Al ２ O ３ Total content (MgO + Al ２ O ３ ) is 8.0 mol% or less, Li ２ O, Na ２ O and K ２ Total O content (Li ２ O + Na ２ O+K ２ O) is 15 mol% or less, Formula 6 below: (Formula 6) C-3478×exp(-2.278×R)≧0 Satisfying the conditions, In the aforementioned formula 6, C is the CuO content per molar volume of glass (unit: millimoles / cc), R is the aforementioned ratio (O ions / P ions), Sb ２ O ３ The content is less than 2.0% by mass when expressed as an external percentage, and Near-infrared absorbing glass that does not contain As as a glass component.

7. In glass composition expressed in mol% based on oxides, Li ２ Ratio of BaO content to O content (BaO / Li ２ O) is 1.0 or higher, And the following (1) to (4): (1) The ratio of the total content of CaO, SrO, and ZnO to the BaO content ((CaO + SrO + ZnO) / BaO) is 0.02 or more. (2) The ratio of the total content of CaO, SrO, and ZnO to the total content of MgO and BaO ((CaO + SrO + ZnO) / (MgO + BaO)) is 0.02 or more. (3) K in relation to BaO content ２ The ratio of the total content of O + CaO + SrO ((K ２ If O + CaO + SrO) / BaO) is 0.12 or higher, (4) The ratio of the total content of K2O, CaO, SrO and ZnO to the total content of MgO and BaO ((K ２ If (O + CaO + SrO + ZnO) / (MgO + BaO) is 0.12 or higher, A near-infrared absorbing glass according to any one of claims 1 to 6, which satisfies one or more of the following conditions.

8. λ at half maximum is the wavelength at which the external transmittance, including reflection loss, is 50% above 550 nm. Ｔ The glass thickness at which 50 corresponds to 633 nm is 0.25 mm or less. The near-infrared absorbing glass according to any one of claims 1 to 7, wherein, at the aforementioned thickness, the external transmittance T600 including reflection loss at a wavelength of 600 nm is 50% or more, and the external transmittance T1200 including reflection loss at a wavelength of 1200 nm is 30% or less.

9. λ at half maximum is the wavelength at which the external transmittance, including reflection loss, is 50% above 550 nm. Ｔ The glass thickness at which 50 corresponds to 633 nm is 0.25 mm or less. At the aforementioned thickness, the external transmittance T600, including reflection loss at a wavelength of 600 nm, is 50% or more, and the external transmittance T1200, including reflection loss at a wavelength of 1200 nm, is β1% or less. β1 is given by the following equation B1: (Formula B1) β1=64×R-170 This is a value calculated by, In the above formula B1, The near-infrared absorbing glass according to any one of claims 1 to 7, wherein R is the ratio (O ions / P ions).

10. The transmittance characteristic calculated for a thickness of 0.16 mm is the wavelength at which the external transmittance, including reflection loss, is 50% (half-maximum latitude). Ｔ The near-infrared absorbing glass according to any one of claims 1 to 7, wherein 50 is in the range of 600 nm to 650 nm, the external transmittance T1200 including reflection loss at a wavelength of 1200 nm is 30% or less, and the external transmittance T400 including reflection loss at a wavelength of 400 nm is 70% or more.

11. The transmittance characteristic calculated for a thickness of 0.21 mm is the wavelength at which the external transmittance, including reflection loss, is 50% (half-maximum latitude). Ｔ The near-infrared absorbing glass according to any one of claims 1 to 7, wherein 50 is in the range of 600 nm to 650 nm, the external transmittance T1200 including reflection loss at a wavelength of 1200 nm is 25% or less, and the external transmittance T400 including reflection loss at a wavelength of 400 nm is 70% or more.

12. λ at half maximum is the wavelength at which the external transmittance, including reflection loss, is 50% above 550 nm. Ｔ The glass thickness at which 50 corresponds to 645 nm is 0.25 mm or less. The near-infrared absorbing glass according to any one of claims 1 to 7, wherein, at the aforementioned thickness, the external transmittance T600 including reflection loss at a wavelength of 600 nm is 50% or more, and the external transmittance T1200 including reflection loss at a wavelength of 1200 nm is 30% or less.

13. λ at half maximum is the wavelength at which the external transmittance, including reflection loss, is 50% above 550 nm. Ｔ The glass thickness at which 50 corresponds to 645 nm is 0.25 mm or less. At the aforementioned thickness, the external transmittance T600, including reflection loss at a wavelength of 600 nm, is 50% or more, and the external transmittance T1200, including reflection loss at a wavelength of 1200 nm, is β1% or less. The aforementioned β1 is given by the following formula B1: (Formula B1) β1=64×R-170 This is a value calculated by, In the above formula B1, The near-infrared absorbing glass according to any one of claims 1 to 7, wherein R is the ratio (O ions / P ions).

14. A near-infrared cut filter made of near-infrared absorbing glass according to any one of claims 1 to 13.

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