Glass, near-infrared absorption cut-off filter, and solid-state imaging element

Abstract

The present invention relates to phosphate-based glass having a pair of main surfaces facing each other. At least one of the main surfaces contains P, Al, and R (R: Li, Na, K, Rb, Cs) as glass constituent components. The ratio represented by {compT / compB} is greater than 1.0, where compT is the maximum value in the glass surface layer of the ratio comp represented by {Al2O3 / (ΣR2O+ΣR'O)} (R': Mg, Ca, Sr, Ba, Zn) using content proportions expressed in mol% based on oxides, and compB is the aforementioned ratio in a matrix composition.

Description

Glass, near-infrared absorption cut filter, and solid-state image sensor

[0001] This invention relates to glass, a near-infrared absorption cut filter, and a solid-state image sensor.

[0002] Imaging devices using solid-state image sensors such as CCDs (Charge Coupled Devices) installed in mobile devices, personal computers, and SLR cameras utilize luminous sensitivity correction filters. These filters allow the colors of photographs to be closer to those perceived by the human eye.

[0003] The above-mentioned luminous efficiency correction filter, also known as a near-infrared absorption filter, requires spectral characteristics such as absorbing light in the near-infrared region and transmitting light in the visible region. Therefore, the glass used in near-infrared absorption cut filters often contains Cu ions to absorb light in the near-infrared region.

[0004] One example of such glass is phosphate-based glass. For instance, Patent Document 1 discloses an optical glass element made of phosphate-based glass in which the composition near the surface has less phosphate content compared to the internal composition, in order to improve durability under high temperature and high humidity conditions.

[0005] Japanese Patent Publication No. 10-139474

[0006] It was found that when alkali metals, alkaline earth metals, or Zn were added to such phosphate-based glasses to impart desired properties, the deterioration of the glass under high temperature and high humidity conditions became more pronounced. This is presumed to be because the above components act to break the glass network, resulting in a greater number of non-crosslinked areas that can serve as starting points for glass deterioration, thus exacerbating the degree of deterioration.

[0007] Therefore, the present invention aims to provide glass that exhibits excellent degradation suppression under high temperature and high humidity conditions, even when it contains components that disrupt the glass network. The invention also aims to provide a near-infrared absorption cut filter and a solid-state image sensor made of the above-mentioned glass.

[0008] When an alkali metal component such as Li, Na, K, Rb, or Cs is added, it has the effect of lowering the melting temperature of the glass or suitably obtaining desired optical properties. However, as described above, the deterioration of the glass under high temperature and high humidity becomes remarkable. As a result of intensive studies by the inventors on such a trade-off relationship, it has been found that by reducing the total content ratio of the alkali metal component, alkaline earth metal component, and Zn in the composition of the parent glass (parent composition) on the glass surface, the above problems can be solved, and the present invention has been completed.

[0009] That is, the present invention relates to the following [1] to

[13] . [1] A phosphate glass having a pair of opposing main surfaces, wherein the phosphate glass contains P, Al, and R as glass constituent components, and in at least one of the pair of main surfaces, using the content ratio in mol% based on oxides, for the ratio comp represented by {Al ２ O ３ / (ΣR ２ O + ΣR'O)}, when the maximum value of the ratio in the glass surface layer is comp Ｔ and the ratio in the parent composition is comp Ｂ , the ratio represented by {comp Ｔ / comp Ｂ} is more than 1.0, R is at least one selected from the group consisting of Li, Na, K, Rb, and Cs, and ΣR ２ O in the ratio represents the total content ratio of R ２ O, R' is at least one selected from the group consisting of Mg, Ca, Sr, Ba, and Zn, and ΣR'O in the ratio represents the total content ratio of R'O, a glass. [2] For the total content ratio represented by (ΣR ２ O + ΣR'O) using the content ratio in mol% based on oxides, when the minimum value of the total content ratio in the glass surface layer is (ΣR ２ O + ΣR'O) Ｔ , and the total content ratio in the parent composition is (ΣR ２ O + ΣR'O) Ｂ , then {(ΣR ２ O + ΣR'O)Ｔ / (ΣR ２ O+ΣR'O) Ｂ The glass according to [1] above, wherein the ratio expressed as} is 0.90 or less. [3] The content of the base composition in mol% based on oxides is P ２ O ５ :25% or more, Al ２ O ３ : 1% or more, and ΣR ２ [1] or [2] above, wherein the content of O: 0.5% or more is satisfied. [4] The glass according to [3] above, wherein the content of the base composition in mol% based on oxides further satisfies the total of near-infrared absorbing components: 0.5% or more. [5] The glass according to [4] above, wherein the near-infrared absorbing component contains at least one selected from the group consisting of Cu, Fe, and V. [6] The glass according to [4] or [5] above, wherein the near-infrared absorbing component contains Cu, and the content of the base composition in mol% based on oxides further satisfies the total of CuO: 0.5% or more. [7] The content of the base composition in mol% based on oxides is P ２ O ５ :25~80%, Al ２ O ３ : 1-30%, ΣR ２ [1] to [2] above, the glass according to any one of [1] to [2] above, satisfying O: 0.5 to 35%, ΣR'O: 0 to 30%, and CuO: 0.5 to 30%. [8] The glass according to [2] above, further satisfying that the content of the parent composition in molar percentage is F: 7% or less. [9] The glass according to any one of [1] to [2] above, having a thickness of 0.03 mm or more.

[10] The glass according to any one of [1] to [2] above, having a transmittance of 70% or more at a wavelength of 550 nm when converted to a thickness of 0.2 mm.

[11] The glass according to any one of [1] to [2] above, having a transmittance of 30% or less at a wavelength of 800 nm when converted to a thickness of 0.2 mm.

[12] A near-infrared absorption cut filter made of the glass according to any one of [1] to [2] above.

[13] A solid-state image sensor including the near-infrared absorption cut filter according to [2] above.

[0010] According to the present invention, even when a component that breaks the glass network is included to obtain desired properties, glass with excellent degradation suppression under high temperature and high humidity conditions can be obtained. As a result, a suitable near-infrared absorption cut filter with excellent weather resistance, and a solid-state image sensor including the above-mentioned near-infrared absorption cut filter can also be provided.

[0011] Figure 1 shows the {Al} obtained from the XPS analysis results of the glass obtained in Example 1. ２ O ３ / (ΣR ２ This graph shows the relationship between the ratio of the content expressed as {O + ΣR'O} and the glass depth.

[0012] The present invention will be described in detail below, but the present invention is not limited to the following embodiments and can be modified and implemented as appropriate without departing from the spirit of the invention. In this specification, glass at a depth of more than 15 μm from the glass surface is referred to as the mother glass. The composition of the mother glass may also be referred to as the mother composition. The composition of the inside of the glass according to this embodiment (bulk composition) can be considered to be the same as the above-mentioned mother composition, and is the composition of a region where there is no compositional change. For example, the mother composition can be determined by measuring the composition at the center of the glass in the thickness direction. In this specification, the depth from 10 to 300 nm from the glass surface may also be simply referred to as the "glass surface layer". This is because the outermost surface of the glass and the glass from the outermost surface to a depth of 10 nm are very susceptible to the influence of the external environment, and analysis is unstable due to fluctuations. Therefore, the characteristics of the above-mentioned predetermined depth range are adopted as the characteristics of the glass surface. Furthermore, in this specification, "~" indicating a numerical range is used to mean that the numerical values ​​written before and after it are included as the lower limit and upper limit. In this specification, mass% and weight% are synonymous.

[0013] 《Glass》 The glass according to this embodiment is a phosphoric acid-based glass having a pair of opposing main surfaces, and contains P, Al and R as glass components. The above glass has at least one of the pair of main surfaces, and the content ratio in molar percentage on an oxide basis is expressed as {Al ２ O ３ / (ΣR ２For the ratio comp expressed as {O + ΣR'O}, the maximum value of the ratio at the glass surface (a depth of 10 to 300 nm from the glass surface) is given by comp. Ｔ , the ratio in the base composition is comp Ｂ When this happens, {comp Ｔ / comp Ｂ The ratio represented by {Al ２ O ３ / (ΣR ２ In the ratio comp expressed as {O + ΣR'O}, ΣR ２ O is R ２ ΣR'O represents the total percentage of O content, and ΣR'O represents the total percentage of R'O content.

[0014] The glass according to this embodiment is a phosphate-based glass containing phosphorus (P) as a network-forming component. Therefore, it contains P as an essential component of the glass. In addition to the above, it contains Al from the viewpoint of weather resistance and R from the viewpoint of meltability. It may also contain R' as an optional component, and R' also improves meltability.

[0015] On the other hand, as mentioned earlier, R and R' work to break the glass network. Therefore, glass containing R and R' has many non-crosslinked areas that can become the starting point for glass degradation, and the degree of degradation is particularly pronounced under high temperature and high humidity conditions.

[0016] In contrast, the glass according to this embodiment is the same as the {comp Ｔ / comp Ｂ The ratio represented by {Al} is greater than 1.0. That is, {Al} in the glass surface layer. ２ O ３ / (ΣR ２ The maximum value of (comp) O + ΣR'O) Ｔ ) is {Al} in the matrix composition of glass. ２ O ３ / (ΣR ２ The value of (O + ΣR'O)} (comp ＢIt is larger than ). This suppresses deterioration under high temperature and high humidity conditions, resulting in glass with excellent weather resistance.

[0017] The glass according to this embodiment is {comp Ｔ / comp Ｂ The ratio expressed as} should be greater than 1.0, and preferably 2800 or less. Here, the above ratio is greater than 1.0, preferably 1.2 or more, more preferably 1.5 or more, and even more preferably 5.0 or more. Furthermore, there is no particular upper limit to the above ratio, but from the viewpoint of manufacturing cost, 2800 or less is preferred.

[0018] The glass according to this embodiment is expressed using the content ratio in mole percent based on oxides (ΣR ２ For the total content ratio expressed as (O + ΣR'O), the minimum value of the glass surface is (ΣR ２ O+ΣR'O) Ｔ , the value in the parent composition (ΣR ２ O+ΣR'O) Ｂ When this is done, {(ΣR ２ O+ΣR'O) Ｔ / (ΣR ２ O+ΣR'O) Ｂ The ratio expressed as} is preferably 0.90 or less. Here, from the viewpoint of weather resistance under high temperature and high humidity, the above ratio is preferably 0.90 or less, more preferably 0.80 or less, and even more preferably 0.50 or less. Also, from the viewpoint of glass productivity, the above ratio is preferably 0.1 or more.

[0019] Furthermore, Al in the glass surface layer (depth of 10 to 300 nm from the glass surface) ２ O ３ ΣR ２ The content ratios of O and ΣR'O are measured using values ​​obtained by methods such as X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), and Rutherford backscattering spectroscopy (RBS). In addition, the Al content in the mother glass (at a depth of more than 15 μm from the glass surface) is also measured. ２ O ３ ΣR ２The content ratio of O and ΣR'O is measured using values ​​obtained by X-ray fluorescence spectroscopy, XPS, AES, RBS while the material is in solid form, or by ICP emission spectroscopy, ICP mass spectrometry, or atomic absorption spectrometry after dissolving in acid. If an optical film or other film is deposited on the glass surface, the glass surface is defined as the location where the concentration of P is half that of the base composition. The base composition of the glass is determined by quantifying the constituent cation elements of the glass as 100%, and then converting the cations to molar percentages based on oxides. For fluorine (F), the amount of F contained in the glass is used. － When the other constituent elements are set to 100 mol% on an oxide basis, the amount of F contained in the glass － The content is calculated by dividing by the external proportion.

[0020] Next, we will explain each component of the glass matrix composition. Unless otherwise specified, the content percentages of each component described below are expressed in mole percent based on oxides.

[0021] <Composition> In the glass according to this embodiment, phosphorus (P) is a network-forming component and a main component necessary for vitrification. It is also a component that enhances the absorption of light in the near-infrared region. P in the matrix composition of the glass, expressed in molar percentage based on oxide. ２ O ５ The content of is not limited to 0%, but is preferably 25% or more, and more preferably 25-80%. Here, from the viewpoint of forming a network to form glass and suitably absorbing light in the near-infrared region, the above P ２ O ５ The content of is preferably 25% or more, more preferably 28% or more, even more preferably 30% or more, even more preferably 35% or more, especially preferably 40% or more, and particularly preferably 45% or more. Furthermore, from the viewpoint of suppressing the decrease in the transmittance of visible light due to the melting temperature becoming too high when manufacturing the glass, the above P ２ O ５ The content ratio is preferably 80% or less, more preferably 75% or less, even more preferably 70% or less, even more preferably 65% ​​or less, and particularly preferably 60% or less.

[0022] Al ２ O ３is a component for enhancing weather resistance. Al ２ O ３ The content ratio only needs to exceed 0%, but is preferably 1% or more, and more preferably 1 to 30%. Here, from the viewpoint of enhancing the weather resistance of the glass, the content ratio of Al ２ O ３ is preferably 1% or more, more preferably 2% or more, and even more preferably 3% or more. Also, from the viewpoint of suppressing the decrease in the absorbance in the near-infrared region and the decrease in the light transmittance in the visible region due to the melting temperature of the glass becoming too high, the content ratio of Al ２ O ３ is preferably 30% or less, more preferably 20% or less, even more preferably 17% or less, and still more preferably 15% or less.

[0023] R ２ O is a component that lowers the melting temperature of the glass. R means Li, Na, K, Rb, and Cs, and the glass according to this embodiment contains one or more of these. R ２ The total content ratio of O (ΣR ２ O) only needs to exceed 0%, but is preferably 0.5% or more, more preferably 0.5 to 35%, and even more preferably 10 to 35%. Here, from the viewpoint of preferably obtaining the above effects by R ２ O, the total content ratio of R ２ O is preferably 0.5% or more, more preferably 10% or more, even more preferably 12% or more, and still more preferably 14% or more. Also, from the viewpoint of suppressing the glass from becoming unstable, the above total content ratio is preferably 35% or less, more preferably 33% or less, even more preferably 32% or less.

[0024] R ２ O preferably contains at least one selected from the group consisting of Li ２ O, Na ２ O, and K ２ O, more preferably contains at least one of Li ２ O and Na ２ O, and even more preferably contains Li ２ O. Also, it is even more preferable to contain both Li ２ O and Na ２ O.

[0025] R ２ Li as O ２ If O is included, Li ２ The O content is preferably 0.1 to 15%. Here, Li ２ From the viewpoint of suitably obtaining the above effects by O, Li ２ When O is included, the content is preferably 0.1% or more, more preferably 2% or more, even more preferably 4% or more, and even more preferably 6% or more. Also, from the viewpoint of suppressing glass instability, Li ２ The content of O is preferably 15% or less, more preferably 14% or less, even more preferably 13% or less, and even more preferably 12% or less.

[0026] R ２ As O, Na ２ If O is included, Na ２ The O content is preferably 0.1 to 30%. Here, Na ２ From the viewpoint of suitably obtaining the above effects by O, Na ２ When O is included, the content is preferably 0.1% or more, more preferably 1% or more, even more preferably 2% or more, and even more preferably 4% or more. Also, from the viewpoint of suppressing glass instability, Na ２ The content of O is preferably 30% or less, more preferably 28% or less, even more preferably 26% or less, and even more preferably 24% or less.

[0027] R ２ As O, K ２ If O is included, K ２ The content of O is preferably 0.1 to 20%. Here, K ２ From the viewpoint of suitably obtaining the above effects by O, K ２ When O is included, the content is preferably 0.1% or more, more preferably 4% or more, even more preferably 8% or more, and even more preferably 10% or more. Also, from the viewpoint of suppressing glass instability, K ２ The content of O is preferably 20% or less, more preferably 18% or less, even more preferably 16% or less, and even more preferably 14% or less.

[0028] R ２O as Rb ２ If O is included, Rb ２ The O content is preferably 0.1 to 20%. Here, Rb ２ From the viewpoint of suitably obtaining the above effects by O, Rb ２ When O is included, the content is preferably 0.1% or more, more preferably 4% or more, even more preferably 8% or more, and even more preferably 10% or more. Also, from the viewpoint of suppressing glass instability, Rb ２ The content of O is preferably 20% or less, more preferably 18% or less, even more preferably 16% or less, and even more preferably 14% or less.

[0029] R ２ O as Cs ２ If O is included, Cs ２ The O content is preferably 0.1 to 20%. Here, Cs ２ From the viewpoint of suitably obtaining the above effects by O, Cs ２ When O is included, the content is preferably 0.1% or more, more preferably 4% or more, even more preferably 8% or more, and even more preferably 10% or more. Also, from the viewpoint of suppressing glass instability, Cs ２ The content of O is preferably 20% or less, more preferably 18% or less, even more preferably 16% or less, and even more preferably 14% or less.

[0030] R'O is a component that enhances the stability of the glass and lowers its melting temperature. R' represents Mg, Ca, Sr, Ba, and Zn, and the glass according to this embodiment may contain one or more of these. The total content of R'O (ΣR'O) may be 0%, i.e., R'O may not be included, and is preferably 0 to 30%. If R'O is included, its total content is preferably 2% or more, more preferably 4% or more, and even more preferably 6% or more, from the viewpoint of suitably obtaining the effects of R'O. Furthermore, from the viewpoint of suppressing glass instability, the total content of R'O is preferably 30% or less, more preferably 20% or less, and even more preferably 10% or less.

[0031] Of the components of R'O, MgO, CaO, and SrO have the effect of increasing the stability of the glass, but they are components that reduce the absorption of light in the near-infrared region. The total content of these three components is preferably 20% or less, more preferably 15% or less, even more preferably 10% or less, and may not be included at all.

[0032] Of the components of R'O, BaO has the effect of lowering the melting temperature of the glass, but it is also a component that reduces the absorption of near-infrared light, which makes the glass unstable. The BaO content is preferably 0 to 20%. Here, from the viewpoint of suitably lowering the melting temperature of the glass, the content of BaO when included is preferably 5% or more, more preferably 10% or more, and even more preferably 15% or more. On the other hand, from the viewpoint of suppressing the instability of the glass, the BaO content is preferably 20% or less, more preferably 10% or less, even more preferably 5% or less, and may not be included at all.

[0033] Of the components of R'O, ZnO has the effect of lowering the melting temperature of the glass, but it is also a component that reduces the meltability of the glass. The ZnO content is preferably 0 to 20%. Here, from the viewpoint of suitably lowering the melting temperature of the glass, the content of ZnO when included is preferably 1% or more, more preferably 3% or more, and even more preferably 5% or more. Also, from the viewpoint of maintaining the meltability of the glass, the BaO content is preferably 20% or less, more preferably 15% or less, and even more preferably 10% or less.

[0034] In cases where it is desired that the glass according to this embodiment has the property of absorbing near-infrared light, such as when used in a near-infrared absorption cut filter, it is preferable that it contains a component that absorbs light in the near-infrared region, i.e., a near-infrared absorbing component. Here, the near-infrared absorbing component is a component whose maximum absorption wavelength is in the range of 700 to 1200 nm.

[0035] Examples of near-infrared absorbing components include Cu, Fe, and V. That is, the glass according to this embodiment may contain at least one selected from the group consisting of Cu, Fe, and V as a near-infrared absorbing component, and containing at least Cu is more preferable from the viewpoint of efficiently absorbing light in the near-infrared region.

[0036] Such near-infrared absorbing components are essential when it is desired to impart near-infrared absorption properties, but they tend to further reduce weather resistance under high temperature and high humidity conditions. However, even when the glass according to this embodiment contains near-infrared absorbing components, {comp Ｔ / comp Ｂ By setting} > 1.0, the above weather resistance can be significantly improved.

[0037] When the glass according to this embodiment contains a near-infrared absorbing component, the total content of the near-infrared absorbing component is preferably 0.5% or more, and more preferably 0.5 to 30%. Here, from the viewpoint of increasing the absorption of light in the near-infrared region, the total content is preferably 0.5% or more, more preferably 5% or more, even more preferably 7% or more, and even more preferably 10% or more. Furthermore, from the viewpoint of suppressing a decrease in visible light transmittance, the total content is preferably 30% or less, more preferably 27% or less, even more preferably 25% or less, and even more preferably 23% or less.

[0038] When Cu is included as a near-infrared absorbing component, the CuO content in terms of oxide mole percent is preferably 0.5% or more, and more preferably 0.5 to 30%. Here, from the viewpoint of efficiently absorbing light in the near-infrared region and from the viewpoint of improving the strength and stability of the glass, the CuO content is preferably 0.5% or more, more preferably 1% or more, even more preferably 5% or more, and even more preferably 10% or more. Furthermore, from the viewpoint of suppressing a decrease in the visible transmittance of the glass, the CuO content is preferably 30% or less, more preferably 26% or less, even more preferably 22% or less, and even more preferably 18% or less.

[0039] Fe when Fe is included as a near-infrared absorbing component ２ O ３ The content of is preferably 0.5% or more, and more preferably 0.5 to 30%. Here, from the viewpoint of increasing the absorption of light in the near-infrared region, Fe ２ O ３ The content of is preferably 0.5% or more, more preferably 5% or more, even more preferably 7% or more, and even more preferably 10% or more. Also, Fe ３＋From the perspective of suppressing the decrease in visible light transmittance due to an increase in the proportion of Fe ２ O ３ The content ratio is preferably 30% or less, more preferably 27% or less, even more preferably 25% or less, and even more preferably 23% or less.

[0040] V when V is included as a near-infrared absorbing component ２ O ５ The content of is preferably 0.5% or more, and more preferably 0.5 to 10%. Here, from the viewpoint of increasing the absorption of light in the near-infrared region, V ２ O ５ The content of is preferably 0.5% or more, more preferably 1.0% or more, even more preferably 1.5% or more, and even more preferably 2.0% or more. Also, from the viewpoint of suppressing a decrease in visible light transmittance, V ２ O ５ The content of is preferably 10% or less, more preferably 9% or less, even more preferably 8% or less, even more preferably 7% or less, and particularly preferably 6% or less.

[0041] In addition to the above, the glass according to this embodiment may contain other components to the extent that it does not significantly impair the effects of the present invention. Other components include, in oxide notation, B ２ O ３ SiO ２ , TiO ２ WO ３ , Nb ２ O ５ MoO ３ , GeO ２ , ZrO ２ , SnO ２ , CEO ２ Ga ２ O ３ In ２ O ３ TeO ２ Ta ２ O ５ Sb ２ O ３ , Tl ２ O ３ , Bi ２ O ３ , Y ２ O ３ La２ O ３ , Gd ２ O ３ Yb ２ O ３ Examples include, but are not limited to, these.

[0042] Other components include B ２ O ３ o SiO ２ is P ２ O ５ Similarly, it is a component that forms the network of glass.

[0043] P ２ O ５ , B ２ O ３ and SiO ２ The total content of is preferably 25 to 90%. Here, from the viewpoint of suppressing a decrease in the strength of the glass, the total content of is preferably 25% or more, more preferably 30% or more, even more preferably 35% or more, and even more preferably 40% or more. Furthermore, from the viewpoint of suppressing an increase in the melting temperature of the glass, the total content of is preferably 90% or less, more preferably 80% or less, even more preferably 70% or less, and even more preferably 60% or less.

[0044] B ２ O ３ The content ratio of is preferably 0 to 30%. Here, B ２ O ３ If it contains B, from the viewpoint of suppressing the decrease in glass strength, ２ O ３ The content of is preferably 1% or more, more preferably 5% or more, and even more preferably 10% or more. Also, from the viewpoint of suppressing the deterioration of the weather resistance of the glass, B ２ O ３ The content ratio is preferably 30% or less, more preferably 25% or less, even more preferably 20% or less, and even more preferably 15% or less.

[0045] SiO ２ The content ratio of is preferably 0 to 30%. Here, SiO ２ If it contains SiO, from the viewpoint of improving the weather resistance of the glass, ２The content of is preferably 0.5% or more, more preferably 1% or more, and even more preferably 2% or more. Also, from the viewpoint of suppressing the rise in the melting temperature of the glass, SiO ２ The content ratio is preferably 30% or less, more preferably 25% or less, even more preferably 20% or less, and even more preferably 15% or less.

[0046] TiO ２ WO ３ and Nb ２ O ５ TiO is an ingredient that improves the weather resistance of glass. ２ WO ３ and Nb ２ O ５ When one or more selected from the group consisting of the above are included, the total content of these is preferably 0 to 30%. Here, from the viewpoint of making it easier to obtain the above effect, the total content is preferably 2.5% or more, more preferably 5% or more, even more preferably 7.5% or more, and even more preferably 10% or more. Furthermore, from the viewpoint of suppressing the decrease in visible transmittance of the glass, the total content is preferably 30% or less, more preferably 25% or less, and even more preferably 20% or less.

[0047] TiO ２ The content of TiO is preferably 0 to 10%. ２ If it contains TiO, from the viewpoint of improving the weather resistance of the glass, ２ The content of is preferably 1% or more, more preferably 2% or more, and even more preferably 3% or more. Also, from the viewpoint of suppressing a decrease in transmittance in the visible range, TiO ２ The content ratio is preferably 10% or less, more preferably 9% or less, even more preferably 8% or less, and even more preferably 7% or less.

[0048] WO ３ The content ratio of is preferably 0 to 10%. Here, WO ３ If it contains WO, from the viewpoint of improving the weather resistance of the glass, ３ The content of is preferably 1% or more, more preferably 2% or more, and even more preferably 3% or more. Also, from the viewpoint of suppressing a decrease in transmittance in the visible range, WO ３The content ratio is preferably 10% or less, more preferably 9% or less, even more preferably 8% or less, and even more preferably 7% or less.

[0049] Nb ２ O ５ The content of Nb is preferably 0 to 10%. ２ O ５ If it contains Nb, from the viewpoint of improving the weather resistance of the glass, ２ O ５ The content of is preferably 1% or more, more preferably 2% or more, and even more preferably 3% or more. In addition, from the viewpoint of suppressing a decrease in transmittance in the visible range, Nb ２ O ５ The content ratio is preferably 10% or less, more preferably 9% or less, even more preferably 8% or less, and even more preferably 7% or less.

[0050] MoO ３ This component increases the visible light transmittance and weather resistance of the glass, and its content is preferably 0 to 10%. Here, MoO ３ If it contains MoO, in order to obtain its full effect, ３ The content of is preferably 0.02% or more, more preferably 0.05% or more, even more preferably 0.07% or more, even more preferably 0.10% or more, and most preferably 0.15% or more. In addition, from the viewpoint of suppressing devitrification of glass and suppressing the decrease in light absorption in the near-infrared region, MoO ３ The content of is preferably 5.0% or less, more preferably 3.0% or less, even more preferably 2.0% or less, even more preferably 1.5% or less, and most preferably 1.0% or less.

[0051] Yb ２ O ３ Yb is a component that enhances the absorption of light in the near-infrared region, and its content is preferably 0 to 10%. ２ O ３ If it contains Yb, in order to obtain its full effect, ２ O ３ The content of is preferably 0.5% or more, more preferably 1.0% or more, and even more preferably 2.0% or more. Also, Yb ２ O ３The content is preferably 10% or less, more preferably 9% or less, even more preferably 8% or less, and even more preferably 7% or less.

[0052] The proportions of each component constituting the glass according to this embodiment have been described, but if other components are included, the total proportion of those components is preferably 0 to 5%. Here, from the viewpoint of suitably obtaining the effects of the other components, the total proportion is more preferably 0.1% or more, and even more preferably 0.2% or more. Furthermore, from the viewpoint of preventing devitrification of foreign matter precipitates in the glass, the total proportion is preferably 5% or less, more preferably 4% or less, and even more preferably 3% or less.

[0053] The glass according to this embodiment may be a fluoride-containing glass, specifically a fluoride-containing glass known as fluoride-containing glass. Fluoride-containing glass exhibits high weather resistance due to its fluoride content. On the other hand, from the viewpoint of environmental protection, the content of F in the base composition of the glass according to this embodiment is preferably 7% or less, more preferably 5% or less, even more preferably 3% or less, even more preferably 2% or less, particularly preferably 1% or less, and may not be included at all. Note that the content of F in this specification is expressed as an external percentage of the base composition and is not included in the total content of the glass components expressed in mol% based on oxides in the glass according to this embodiment.

[0054] Furthermore, the glass according to this embodiment is PbO, As ２ O ３ , and GdF ３ It is preferable that none of the following are substantially contained. PbO is a component that lowers the viscosity of the glass and improves the workability of the manufacturing process. Also, As ２ O ３ It is a component that acts as an excellent clarifying agent capable of generating clarified gas over a wide temperature range. However, PbO and As ２ O ３ Since both are environmentally harmful substances, it is preferable to include as little as possible. GdF ３Although these components stabilize the glass, their raw materials are relatively expensive, leading to increased costs; therefore, it is preferable to omit them as much as possible. Regarding the three components mentioned above, "substantially absent" means not intentionally used as raw materials, and the content of each component in the glass is 0.1% or less.

[0055] Based on these considerations, it is preferable that the base composition of the glass according to this embodiment satisfies the following requirements in terms of the content ratio in mole percent based on oxides: P ２ O ５ :25% or more, Al ２ O ３ : 1% or more, and ΣR ２ O: 0.5% or more.

[0056] Furthermore, regarding the base composition of the glass according to this embodiment, more preferred embodiments include, for example, the following. However, it is not limited to the following. P ２ O ５ :25% or more, Al ２ O ３ : 1% or more, ΣR ２ The requirements are met: O: 0.5% or more, and total of near-infrared absorbing components: 0.5% or more.

[0057] P ２ O ５ :25% or more, Al ２ O ３ : 1% or more, ΣR ２ The composition satisfies the following conditions: O: 0.5% or more, and CuO: 0.5% or more.

[0058] P ２ O ５ :25% or more, Al ２ O ３ : 1% or more, ΣR ２ O: 0.5% or more, and CuO + Fe ２ O ３ +V ２ O ５ : Meets the requirement of 0.5% or more.

[0059] P ２ O ５ :25~80%, Al ２ O ３: 1-30%, ΣR ２ The following conditions must be met: O: 0.5-35%, ΣR'O: 0-30%, and total near-infrared absorbing components: 0.5-30%.

[0060] P ２ O ５ :25~80%, Al ２ O ３ : 1-30%, ΣR ２ The following conditions must be met: O: 0.5-35%, ΣR'O: 0-30%, and CuO: 0.5-30%.

[0061] P ２ O ５ :25~80%, Al ２ O ３ : 1-30%, ΣR ２ O: 0.5-35%, ΣR'O: 0-30%, and CuO + Fe ２ O ３ +V ２ O ５ : Meets the requirement of 0.5-30%.

[0062] P ２ O ５ :25~80%, Al ２ O ３ : 1-30%, ΣR ２ The composition satisfies the following conditions: O: 0.5-35%, ΣR'O: 0-30%, CuO: 0.5-30%, and F: 7% or less when divided externally.

[0063] <Characteristics and Physical Properties> The glass according to this embodiment has a pair of opposing main surfaces. Here, the shape and size of the main surfaces are not particularly limited. Therefore, any shape such as rectangular, circular, or elliptical can be adopted. Furthermore, the properties of the main surfaces are not particularly limited, and the main surfaces may be flat, concave, or convex like lenses. Moreover, the main surfaces may have one or more recesses or convex portions in at least a part of them.

[0064] The glass according to this embodiment has, on at least one of the pair of main surfaces, {comp Ｔ / comp Ｂ The ratio represented by {comp} should be greater than 1.0, but it is preferable that the above ratio on both main surfaces is greater than 1.0. However, {comp} on both main surfacesＴ / comp Ｂ The ratio values ​​expressed as} may be the same or different.

[0065] The thickness of the glass according to this embodiment is preferably 0.03 mm or more, and more preferably 0.03 to 1 mm. Here, from the viewpoint of obtaining strength to prevent breakage during manufacturing, transportation, and when incorporated into a solid-state image sensor, the above thickness is preferably 0.03 mm or more, more preferably 0.05 mm or more, even more preferably 0.07 mm or more, and particularly preferably 0.1 mm or more. Furthermore, from the viewpoint of responding to the miniaturization and thinning of devices and equipment that mount glass, such as solid-state image sensors, the above thickness is preferably 1 mm or less, more preferably 0.8 mm or less, even more preferably 0.6 mm or less, particularly preferably 0.4 mm or less, and most preferably 0.3 mm or less.

[0066] When the glass according to this embodiment is used as a near-infrared absorption cut filter, high transmittance of visible light is required as a spectral characteristic. Therefore, the transmittance of the glass at a wavelength of 550 nm is preferably 70% or more, more preferably 75% or more, even more preferably 80% or more, and even more preferably 85% or more. Furthermore, it is preferable that the transmittance is as close to 100% as possible, but it is usually 92% or less.

[0067] In this specification, the transmittance of glass refers to the external transmittance including reflection loss on both the front and back surfaces.

[0068] Furthermore, the transmittance referred to in this specification is the transmittance calculated assuming a glass thickness of 0.2 mm. The above conversion can be performed using the following formula. ｉ２ = T ｉ１ ｔ２／ｔ１ In the above formula, T ｉ１ This is the internal transmittance of the measured sample (transmittance excluding reflection loss from the front and back surfaces), and T ｉ２ {100 × (1 - R)} is the converted internal transmittance, t1 is the thickness of the measurement sample (mm), and t2 is the thickness to be converted, which in this specification is 0.2 mm. The conversion from transmittance to internal transmittance is performed using the following formula, assuming that the reflection loss R on both the front and back surfaces of the glass is 0.0454 each: Internal transmittance = External transmittance / {100 × (1 - R)}２}

[0069] When the glass according to this embodiment is used as a near-infrared absorption cut filter, high absorption of light in the near-infrared region is required. Therefore, the transmittance of the glass at a wavelength of 800 nm is preferably 30% or less, more preferably 25% or less, even more preferably 20% or less, even more preferably 15% or less, and particularly preferably 10% or less. Furthermore, the transmittance is preferably as close to 0% as possible, but is usually 0.01% or more.

[0070] The glass transition temperature (Tg) of the glass according to this embodiment is preferably 325 to 600°C. Here, from the viewpoint of increasing the stability of the glass, the glass transition temperature is preferably 325°C or higher, more preferably 350°C or higher, even more preferably 375°C or higher, even more preferably 400°C or higher, and even more preferably 425°C or higher. Furthermore, from the viewpoint of suppressing the rise in the melting temperature of the glass, the glass transition temperature is preferably 600°C or lower, more preferably 575°C or lower, even more preferably 550°C or lower, even more preferably 525°C or lower, and even more preferably 500°C or lower.

[0071] The β-OH value of the glass according to this embodiment is set to 1 mm in order to further improve the weather resistance of the glass. －１ The following is preferable: 0.8 mm －１ The following is more preferable: 0.5 mm －１ The following is even more preferable: 0.25 mm －１ The following is even more preferable. The lower limit of the β-OH value is not particularly limited, but for example, 0.01 mm －１ That concludes the explanation. Note that the β-OH value used herein correlates with the water content in the glass and is measured by Fourier transform infrared spectroscopy (FT-IR) at 3550 cm⁻¹. －１ It can be determined by dividing the absorbance at a given point by the thickness of the glass.

[0072] <Manufacturing Method> The glass according to this embodiment contains P, Al and R as glass components, {comp Ｔ / comp ＢAs long as a phosphate-based glass is obtained in which the ratio expressed by} is greater than 1.0, the method of manufacturing it is not particularly limited. That is, one embodiment of the method of manufacturing the glass according to this embodiment will be described below, but it is not limited to the embodiment described below.

[0073] The method for manufacturing glass according to this embodiment includes the following steps: Step 1: A step of preparing glass having a pair of opposing main surfaces Step 2: {comp Ｔ / comp Ｂ A process in which the ratio expressed as} is greater than 1.0

[0074] Step 1 Step 1 is the process of preparing a glass having a pair of opposing main surfaces. The glass may be commercially available or manufactured. Alternatively, commercially available glass that has undergone desired treatment may be used. The composition of the glass obtained in Step 1 becomes the composition of the mother glass (mother composition).

[0075] Glass can be manufactured using conventionally known methods. For example, glass can be prepared by the following steps 1-1 to 1-3. Step 1-1: Weighing and mixing glass raw materials to obtain a raw material mixture. Step 1-2: Heating and melting the raw material mixture obtained in step 1-1. Step 1-3: Molding the molten material obtained in step 1-2.

[0076] In step 1-1, the glass raw materials used can be those that are conventionally known, and the raw material mixture can be obtained by employing conventionally known methods.

[0077] The conditions for heating and dissolving the raw material mixture in step 1-2 can also be those of conventionally known methods and conditions. For example, the heating temperature is preferably 700 to 1450°C. Here, from the viewpoint of suppressing the occurrence of devitrification and shortening the manufacturing time, the heating temperature is preferably 700°C or higher, more preferably 800°C or higher, even more preferably 900°C or higher, and even more preferably 1000°C or higher. Furthermore, from the viewpoint of suppressing a decrease in the transmittance of visible light, the heating temperature is preferably 1450°C or lower, more preferably 1400°C or lower, even more preferably 1350°C or lower, and even more preferably 1300°C or lower.

[0078] Step 1-3 is a process in which the molten material of the raw material mixture obtained by heating and melting in Step 1-2 is molded. Between Step 1-2 and Step 1-3, an oxidizing agent may be added or clarification may be performed as needed.

[0079] Examples of additives and clarifying agents include nitrate compounds and sulfate compounds that have cations that form glass. The oxidizing agent is Cu in the total amount of Cu in the glass. ２＋ Increasing the proportion of ions improves the transmittance of visible light and the absorption of near-infrared light.

[0080] The amount of nitrate compounds and sulfate compounds added is preferably 0.5 to 10% by mass relative to the raw material mixture, added on an external basis. From the viewpoint of further improving the transmittance of visible light, the amount of addition is preferably 0.5% by mass or more, more preferably 1% by mass or more, and even more preferably 3% by mass or more. Furthermore, from the viewpoint of the effect of the addition plateauing and the ability to form glass, the amount of addition is preferably 10% by mass or less, more preferably 8% by mass or less, and even more preferably 6% by mass or less.

[0081] Examples of nitrate compounds include Al(NO). ３ ) ３ LiNO ３ NaNO ３ , KNO ３ Ca(NO ３ ) ２ , Sr(NO ３ ) ２ , Ba (NO ３ ) ２ , Zn (NO ３ ) ２ Cu(NO ３ ) ２ Examples include Al ２ (SO ４ ) ３ 16H ２ O, Li ２ SO ４ Na ２ SO ４ _K ２ SO ４ CaSO ４ , SrSO ４ , BaSO４ ZnSO ４ , CdSO ４ These are some examples.

[0082] Step 2 Step 2 involves {comp on at least one main surface of the glass obtained in Step 1 Ｔ / comp Ｂ This is a process in which the ratio represented by} is made greater than 1.0. In other words, in process 2, the composition of the main surface of the glass prepared in process 1 is modified.

[0083] In step 2 of this embodiment, the ΣR of the glass surface ２ Al ２ O ３ By reducing the proportion of the content relative to {comp Ｔ / comp Ｂ The ratio expressed as} can be greater than 1.0. In order to reduce the above content ratio, from the glass surface, ΣR ２ A method for leaching at least one of O and ΣR'O, or ΣR on the glass surface ２ One method involves inserting at least one of O and ΣR'O into the glass. Here, by performing the above reaping from the glass surface or inserting into the glass, the ΣR of the glass surface is ultimately... ２ Al of O or ΣR'O ２ O ３ The proportion of the substance contained in the substance will also be reduced.

[0084] The specific methods for performing such compositional modification are not particularly limited, but examples include heat treatment, gas treatment, chemical treatment, ion exchange treatment, and plasma treatment. Furthermore, two or more of these treatments may be combined.

[0085] (Heat Treatment) When the above compositional modification is carried out by heat treatment, it is preferable to carry it out at a temperature close to the glass transition temperature (Tg) of the glass obtained in step 1. The heat treatment temperature is preferably in the range of (Tg ± 100) °C, more preferably in the range of (Tg ± 50) °C, and preferably in the range of (Tg ± 30) °C. When heat treatment is performed, OH groups (moisture) present on the surface of the glass are leached to the outside of the glass by dehydration condensation, and internal OH groups (moisture) move to the glass surface layer. In conjunction with this movement, the R of the glass surface layer from the viewpoint of charge compensation ２ As O and R'O move into the glass, the R on the glass surface ２ It is thought that the proportion of O and R'O can be reduced.

[0086] The heat treatment processing time is preferably, for example, 0.1 to 500 hours. Here, from the viewpoint of sufficient compositional modification, the processing time is preferably 1 hour or more, more preferably 2 hours or more, and even more preferably 6 hours or more. Also, from the viewpoint of productivity, the processing time is preferably 200 hours or less, more preferably 100 hours or less, and even more preferably 50 hours or less.

[0087] Heat treatment is preferably carried out in an inert atmosphere. Specifically, in an Ar atmosphere, N ２ Examples include a poor atmosphere.

[0088] The heat treatment is preferably carried out in an atmosphere with a low moisture content. For example, the dew point of the atmosphere in which the heat treatment is performed is preferably -10°C or lower, more preferably -30°C or lower, and even more preferably -50°C or lower.

[0089] (Gas Treatment) When the above compositional modification is carried out by gas treatment, for example, gas treatment is performed with halogen gas. Among these, treatment with a gas containing fluorine atoms is more preferable. Treatment with a gas containing fluorine atoms includes treatment with fluorine gas and treatment with fluorine compounds. When gas treatment is performed, the phosphorus component of the glass becomes PF ３ ya PF ５ It is thought that reaching the outside of the glass in this form will relatively increase the proportion of Al. ２ It is thought that O and R'O are fluorinated, causing them to reach the outside of the glass as fluoride salts.

[0090] Gas treatment methods include placing the glass obtained in step 1 into a space filled with a predetermined gas, and spraying a predetermined gas onto the glass surface. Among these, the method of placing the glass into a space filled with a predetermined gas is preferred, and it is more preferable that the space is a furnace.

[0091] When employing the above-described fluorine gas treatment method, the fluorine gas concentration is preferably 0.1% to 50% by volume, and the treatment temperature is preferably room temperature to 300°C. Furthermore, after the fluorine gas treatment, an additional method can be added to stabilize the composition of the glass surface by annealing in an inert gas atmosphere. In this case, the annealing treatment is preferably performed at the glass transition temperature (Tg ± 100)°C.

[0092] (Chemical treatment) When the above composition modification is carried out by chemical treatment, for example, the chemical treatment is performed using an acidic chemical solution such as hydrochloric acid, nitric acid, sulfuric acid, or phosphoric acid. When chemical treatment is performed, R present on the surface of the glass ２ It is thought that O and R'O are reaching outside the glass.

[0093] (Ion exchange treatment) When the above compositional modification is carried out by ion exchange treatment, for example, by immersing the glass in an aqueous hydrochloric acid solution as described above, R ions and R' ions in the glass are exchanged with H in the aqueous solution. ＋ One method involves ion exchange. Another method involves ion exchange between the desired cation and R and R' using molten salts such as nitrates, sulfates, and chlorides.

[0094] Near-infrared absorption cut filter according to this embodiment is made of the glass described in the above section, and among them, glass containing a near-infrared absorbing component is preferred. The preferred embodiment of this glass is the same as the preferred embodiment described in the above section.

[0095] The near-infrared absorption cut filter according to this embodiment may have an optical multilayer film provided on at least one main surface of a glass molded into a predetermined shape. Examples of optical multilayer films include IR cut films, UV / IR cut films (films that reflect ultraviolet and near-infrared rays), UV cut films, and anti-reflective films. Optical multilayer films can be formed by conventionally known methods, such as vapor deposition and sputtering.

[0096] A bonding reinforcement film may be provided between the glass and the optical multilayer film. This improves the adhesion between the glass and the optical multilayer film and suppresses film delamination. Examples of bonding reinforcement films include silicon dioxide (SiO₂). ２ ), titanium oxide (TiO ２ ), lanthanum titanate (La ２ Ti ２ O ７ ), aluminum oxide (Al ２ O ３ ), aluminum oxide and zirconium oxide (ZrO ２ A mixture of ) and magnesium fluoride (MgF ２ ), calcium fluoride (CaF ２ ), strontium fluoride (SrF ２ Examples include fluorine and fluorosilicone. Substances containing fluorine or oxygen provide better adhesion, and magnesium fluoride and titanium dioxide are particularly preferred because they provide high adhesion to glass and films. The adhesion-enhancing film may be a single layer or two or more layers. In the case of two or more layers, multiple materials may be combined.

[0097] The near-infrared absorption cut filter according to this embodiment may include an absorption layer on at least one main surface of the glass of this embodiment, which contains a near-infrared absorbing material having the maximum absorption wavelength in the near-infrared region. With such a configuration, an optical filter can be obtained that further reduces the transmittance of light in the near-infrared region.

[0098] The near-infrared absorption cut filter according to this embodiment is preferably made of a transparent resin selected from acrylic resin, epoxy resin, ene-thiol resin, polycarbonate resin, polyether resin, polyarylate resin, polysulfone resin, polyethersulfone resin, polyparaphenylene resin, polyarylene ether phosphine oxide resin, polyimide resin, polyamide-imide resin, polyolefin resin, cyclic olefin resin, and polyester resin, with a near-infrared absorbing dye added to the absorbent layer. Furthermore, it is preferable to use a near-infrared absorbing material consisting of at least one selected from the group consisting of squarylium dye, phthalocyanine dye, cyanine dye, and diimmonium dye as the near-infrared absorbing dye.

[0099] Solid-state image sensor The solid-state image sensor according to this embodiment includes a near-infrared absorption cut filter as described in the "Near-infrared absorption cut filter" section above. The preferred embodiment of this near-infrared absorption cut filter is the same as the preferred embodiment described in the "Near-infrared absorption cut filter" section above.

[0100] The solid-state image sensor according to this embodiment includes an imaging lens in addition to the near-infrared absorption cut filter described above.

[0101] Solid-state image sensors convert incoming light into electrical signals and output them to image signal processing circuits. Examples of solid-state image sensors include Charge Coupled Device (CCD) image sensors and Complementary Metal Oxide Semiconductor (CMOS) image sensors.

[0102] The imaging device using the above-described solid-state image sensor further includes an imaging lens. The near-infrared absorption cut filter may be placed between the imaging lens and the solid-state image sensor. Alternatively, the near-infrared absorption cut filter may be provided independently of the solid-state image sensor, for example, by being directly attached to the imaging lens or the like via an adhesive layer.

[0103] The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. Examples 1 to 5 are examples, and Examples 6 and 7 are comparative examples.

[0104] <Test Example> <Manufacture of Mother Glass> Glass raw materials were weighed and mixed so that the mother composition would be as shown in Table 1, to obtain raw material mixtures of Glass A to Glass C. Next, the raw material mixtures were heated and melted at 1050°C (Glass A), 1050°C (Glass B), or 1175°C (Glass C) for 2 hours. After clarifying and stirring the obtained molten material, it was poured into a mold and slowly cooled. Next, a glass measuring 40 mm x 30 mm with a thickness of 0.21 mm was obtained by polishing. The glass transition temperature (Tg) of each obtained glass is shown in Table 1. Note that "-" in Table 1 means that the material was not intentionally added as a glass raw material.

[0105]

[0106] <Example 1> The glass A obtained above was treated with fluorine gas diluted to 20% by volume with nitrogen in a batch manner and exposed to it at room temperature for 2 hours. The specific conditions for the gas treatment were as follows: Treatment gas: F ２ Gas 20% by volume (diluted with nitrogen) Reaction temperature: room temperature Reaction time: 2 hours After the above gas treatment, annealing treatment was carried out in a nitrogen atmosphere at 400°C for 12 hours.

[0107] <Example 2> The glass A obtained above was subjected to heat treatment in an inert gas atmosphere. The specific conditions for the heat treatment were as follows: Temperature: 450°C Time: 12 hours Atmosphere: Nitrogen atmosphere Dew point: -50°C

[0108] <Example 3> The gas treatment was carried out in the same manner as in Example 1, except that glass C was used instead of glass A.

[0109] <Example 4> Heat treatment was performed in the same manner as in Example 2, except that glass B was used instead of glass A.

[0110] <Example 5> Glass A was used as is, without any treatment.

[0111] <Example 6> Glass B was used as is, without any treatment.

[0112] {comp Ｔ / comp Ｂ For the glasses of Examples 1 to 6, X-ray photoelectron spectroscopy (XPS) was used to determine the Al content at a depth of 10 to 300 nm from the glass surface (glass surface layer). ２ O ３ , R ２ The respective content ratios of O and R'O, and the Al content in the glass matrix composition, which is the Al content in glass etched to a thickness of 15 μm or more. ２ O ３ , R ２ The respective content ratios of O and R'O were measured. Using the content ratios obtained above, {Al ２ O ３ / (ΣR ２ The ratio `comp`, expressed as `O + ΣR'O`, was calculated. Specifically, it was measured under the following conditions.

[0113] <Equipment> X-ray photoelectron spectrometer: ULVAC PHI PHI5000 VersaProbeIII <Conditions> Analysis area: 100 μm in diameter Detection angle: 75° relative to the sample surface X-ray source: Monochrome Al Kα rays X-ray conditions: 100 μm in diameter, 25 W, 15 kV Pass energy: 224.0 eV Sputtered ion species: C60+ Ion gun conditions: Voltage 10 kV, current 10 nA The glass constituent cation elements were quantified as 100%, and the cations were converted to mole percent based on oxides. The depth of the glass is SiO ２ The conversion was performed using the sputter rate.

[0114] From the results of the XPS analysis of the glass obtained in Example 2, {Al ２ O ３ / (ΣR ２ Figure 1 shows a graph illustrating the relationship between the ratio of the content expressed as {O + ΣR'O} and the glass depth. Multipak Version 9.9.3 analysis software from ULVAC PHI was used to analyze the spectra measured by XPS analysis. The Shirley method was applied to remove the background from the spectra, and the relative sensitivity coefficients included in the analysis software were used.

[0115] Furthermore, in the glass surface layers of Examples 1 to 6, ΣR ２ This is the minimum total content ratio of O and ΣR'O (ΣR ２ O+ΣR'O) Ｔ , and {Al ２ O ３ / (ΣR ２ The maximum value of the ratio expressed as {O + ΣR'O} is comp Ｔ , and in the parent composition, ΣR ２ This is the total content ratio of O and ΣR'O (ΣR ２ O+ΣR'O) Ｂ , and {Al ２ O ３ / (ΣR ２ The ratio expressed as {O + ΣR'O} is `comp` Ｂ These were as shown in Table 2.

[0116] 《Evaluation; Weather Resistance》 The glass obtained in Examples 1 to 6 was left standing for 200 hours in an environment of 85°C and 85% RH. After that, the weather resistance under high temperature and high humidity conditions was evaluated by visually observing the glass surface. The results are shown in Table 2, with the evaluation criteria as follows: ○: No defects such as clouding or discoloration were observed on the glass surface; good. ×: Defects such as clouding or discoloration were observed on the glass surface; poor.

[0117] 《Evaluation; Transmittance》 For the glass obtained in Examples 1 to 6, the internal transmittance in the wavelength range of 400 to 1200 nm was measured using a spectrophotometer (JASCO Corporation, V-570). Then, the above-mentioned T ｉ２ = T ｉ１ ｔ２／ｔ１ Based on the given formula, the transmittance was converted to that of a glass thickness of 0.2 mm. The transmittance results at wavelengths of 550 nm and 800 nm are shown in Table 2.

[0118]

[0119] From the above results, in phosphate-based glass, {comp Ｔ / comp ＢIt was found that by setting the ratio represented by {comp} to greater than 1.0, deterioration under high temperature and high humidity conditions is significantly improved, and excellent weather resistance can be achieved. In particular, as shown in Examples 5 and 6, the composition of glass obtained normally remains unchanged between the glass surface and the inside of the glass, {comp} Ｔ / comp Ｂ While the ratio represented by} is 1.0, as shown in Example 1, even slightly increasing the above ratio to 1.8 resulted in a significant improvement in weather resistance.

[0120] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. This application is based on Japanese Patent Application No. 2024-179250, filed on 11 October 2024, the contents of which are incorporated herein by reference.

Claims

1. A phosphate glass having a pair of opposing main surfaces, the phosphate glass containing P, Al, and R as glass constituent components, and in at least one of the pair of main surfaces, using the content ratio in mol% based on oxides, {Al ２ O ３ / (ΣR ２ O + ΣR'O)} for the ratio comp represented by, the maximum value of the ratio in the glass surface layer is comp Ｔ , when the ratio in the parent composition is comp Ｂ , the ratio represented by {comp Ｔ / comp Ｂ} is more than 1.0, R is at least one selected from the group consisting of Li, Na, K, Rb, and Cs, and ΣR ２ O in the ratio represents the total content ratio of R ２ O, R' is at least one selected from the group consisting of Mg, Ca, Sr, Ba, and Zn, and ΣR'O in the ratio represents the total content ratio of R'O, a glass.

2. Using the content percentage expressed in mole percent based on oxides (ΣR ２ Regarding the total content ratio expressed as (O + ΣR'O), the minimum value of the total content ratio on the glass surface is (ΣR ２ O+ΣR'O) Ｔ , the total content ratio in the above base composition is (ΣR ２ O+ΣR'O) Ｂ When this is done, {(ΣR ２ O+ΣR'O) Ｔ / (ΣR ２ O+ΣR'O) Ｂ The glass according to claim 1, wherein the ratio represented by} is 0.90 or less.

3. The content ratio of the above base composition in mole percent based on oxides is P ２ O ５ :25% or more, Al ２ O ３ : 1% or more, and ΣR ２ O: The glass according to claim 1 or 2, satisfying the requirement of 0.5% or more.

4. The glass according to claim 3, wherein the content ratio of the above-mentioned base composition in molar percentage based on oxides further satisfies the requirement that the total of near-infrared absorbing components is 0.5% or more.

5. The glass according to claim 4, wherein the near-infrared absorbing component includes at least one selected from the group consisting of Cu, Fe, and V.

6. The glass according to claim 4, further comprising Cu as the near-infrared absorbing component, wherein the content ratio of the base composition in molar percentage based on oxides is CuO: 0.5% or more.

7. The content ratio of the above-mentioned base composition in mole percent based on oxides is P ２ O ５ :25~80%, Al ２ O ３ : 1-30%, ΣR ２ The glass according to claim 1 or 2, satisfying O: 0.5 to 35%, ΣR'O: 0 to 30%, and CuO: 0.5 to 30%.

8. The glass according to claim 7, wherein the content of the aforementioned base composition in mol% is further satisfied with F: 7% or less.

9. The glass according to claim 1 or 2, wherein the thickness is 0.03 mm or more.

10. The glass according to claim 1 or 2, wherein the transmittance at a wavelength of 550 nm is 70% or more when converted to a thickness of 0.2 mm.

11. The glass according to claim 1 or 2, wherein the transmittance at a wavelength of 800 nm is 30% or less when converted to a thickness of 0.2 mm.

12. A near-infrared absorption cut filter made of glass as described in claim 4.

13. A solid-state image sensor comprising the near-infrared absorption cut filter described in claim 12.

Images