JP2022189704A - Near-infrared absorbing glass and near-infrared cutting filter - Google Patents

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

The present invention relates to a near-infrared absorbing glass and a near-infrared cut filter.

2. Description of the Related Art In compact cameras represented by smartphones and the like in recent years, obtained image information is not only digitized, but also an image is reconstructed by performing various computational processes on the image information. For example, it has become mainstream to extract a specific object and adjust the color and contrast of the image. In this case, if non-existent color information is input to the imaging device due to reflection of light in the optical element, that information must be removed, which is undesirable.

The near-infrared cut filter has a function of cutting unnecessary near-infrared light (wavelength 700 to 1200 nm) in the sensitivity wavelength range of the imaging device. A near-infrared cut filter is generally provided in front of an imaging element in many cases.

As a near-infrared cut filter, near-infrared absorbing glass is used as a base material, and a flat plate with a polished surface is widely used.

Near-infrared absorbing glasses generally contain Cu ions. FIG. 1 shows an example of spectral transmission characteristics of near-infrared absorbing glass. It should be noted that FIG. 1 does not limit the present invention in any way. Light absorption characteristics in the vicinity of wavelengths of 700 to 1200 nm are exhibited by Cu ions (Cu ²⁺ ) in the glass. Among them, glass containing P ions together with Cu ions can exhibit the near-infrared absorption characteristics of Cu ions (Cu ²⁺ ) in a wide wavelength range, and is therefore useful as glass for near-infrared cut filters (for example, patent References 1-3).

JP 2019-38719 A CN110255897 JP-A-55-3336

In the transmittance curve after the wavelength of 600 nm in FIG. 1, the wavelength at which the transmittance is 50% is called "half value", which is one of the major standards for near-infrared cut filters. The half value varies depending on the filter specifications, but is often set within the wavelength range of 600 nm to 650 nm. As a general method for setting the half value to a desired value, there is a method of adjusting either the plate thickness of the glass substrate or the concentration of Cu ions (Cu ²⁺ ) in the glass according to the Lambert-Beer law.

The near-infrared cut filter has an excellent ability to cut near-infrared light (that is, it has a low transmittance of near-infrared light while having a desired half value), and also has a transmittance in the visible range (violet region to red region). is also required to be high.

Further, in recent years, there has been a demand for both miniaturization and high performance in imaging element modules mounted on smartphones and the like, and near-infrared cut filters are required to be thinner. Therefore, the thickness of the near-infrared absorbing glass has also been reduced from the conventional thickness of 1 mm to about 0.45 mm, 0.3 mm, or 0.2 mm in recent years, and it is also desired to reduce the thickness to the order of 0.1 mm. .

If the thickness of the near-infrared absorbing glass is simply reduced, the optical density (number of moles×thickness) of CuO required for near-infrared absorption decreases, resulting in a decrease in near-infrared absorption efficiency. In order to solve this problem, it is conceivable to increase the amount of CuO. However, simply increasing the amount of CuO tends to reduce the transmittance on the short wavelength side, making it difficult to maintain both the transmittance in the visible range (purple to red regions) and the absorption of near-infrared rays. .

Furthermore, in order to provide a near-infrared cut filter suitable for use in a high-temperature and high-humidity environment, it is desired that the near-infrared absorption glass should suppress deterioration in weather resistance in a high-temperature and high-humidity environment. However, according to the study of the present inventor, it is not easy to maintain both the transmittance in the visible region (purple region to red region) and the absorption of near-infrared rays, and to suppress the decrease in weather resistance. .

In view of the above, one aspect of the present invention provides a near-infrared absorption that has high transmittance in the visible region (purple region to red region) even when thinned, has excellent near-infrared cut ability, and can suppress deterioration in weather resistance. An object of the present invention is to provide glass and a near-infrared cut filter made of such near-infrared absorbing glass.

One aspect of the present invention is
Main 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 Including 4 or more types,
containing P ions, Ba ions and Cu ions as essential cations,
In the glass composition expressed in anion %, the content of O ions is 90.0 anion % or more,
In the glass composition expressed in atomic %, the ratio of the content of O ions to the content of P ions (O ions/P ions) (hereinafter also referred to as “O/P ratio”) is 3.15 or less,
In the glass composition expressed in mol% based on oxides,
The total content of B ₂ O ₃ and SiO ₂ (B ₂ O ₃ + SiO ₂ ) is 3.0 mol% or less,
The total content of MgO and Al ₂ O ₃ (MgO + Al ₂ O ₃ ) is 8.0 mol% or less,
the total content of Li ₂ O, Na ₂ O and K ₂ O (Li ₂ O + Na ₂ O + K ₂ O) is 15 mol% or less;
CuO content is α ₁ % or more,
α ₁ has the following formula 1:
(Formula 1)
α ₁ =70400×exp(−2.855×R)
is a value calculated by
In the above formula 1,
R is the above ratio (O ion / P ion),
Near-infrared absorbing glass (hereinafter also referred to as “glass 1”)
Regarding.

In addition, one aspect of the present invention is
Main 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 Including 4 or more types,
containing P ions, Ba ions and Cu ions as essential cations,
In the glass composition expressed in anion %, the content of O ions is 90.0 anion % or more,
In the glass composition expressed in atomic %, the ratio of the content of O ions to the content of P ions (O ions/P ions) is 3.15 or less,
In the glass composition expressed in mol% based on oxides,
The total content of B ₂ O ₃ and SiO ₂ (B ₂ O ₃ + SiO ₂ ) is 3.0 mol% or less,
The total content of MgO and Al ₂ O ₃ (MgO + Al ₂ O ₃ ) is 8.0 mol% or less,
the total content of Li ₂ O, Na ₂ O and K ₂ O (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
The filling,
In the above formula 2,
C is the CuO content per molar volume of the glass (unit: millimoles/cc),
R is the above ratio (O ion / P ion),
Near-infrared absorbing glass (hereinafter also referred to as “glass 2”)
Regarding.

Further, one aspect of the present invention is
Main 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 Including 4 or more types,
containing P ions, Ba ions and Cu ions as essential cations,
In the glass composition expressed in anion %, the content of O ions is 90.0 anion % or more,
In the glass composition expressed in atomic %, the ratio of the content of O ions to the content of P ions (O ions/P ions) is 3.15 or less,
In the glass composition expressed in mol% based on oxides,
The total content of B ₂ O ₃ and SiO ₂ (B ₂ O ₃ + SiO ₂ ) is 3.0 mol% or less,
The total content of MgO and Al ₂ O ₃ (MgO + Al ₂ O ₃ ) is 8.0 mol% or less,
the total content of Li ₂ O, Na ₂ O and K ₂ O (Li ₂ O + Na ₂ O + K ₂ O) is 15 mol% or less;
Equation 3 below:
(Formula 3)
A ₁ = {O(P)−O(others)}×Cu
A ₁ calculated by 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 oxygen content obtained by excluding the O (P) from the oxygen content constituting the oxide of the main cation in the oxide-based glass composition,
Cu indicates the CuO content in mol % in the oxide-based glass composition;
Near-infrared absorbing glass (hereinafter also referred to as “glass 3”)
Regarding.

In addition, one aspect of the present invention is
Main 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 Including 4 or more types,
containing P ions, Ba ions and Cu ions as essential cations,
In the glass composition expressed in anion %, the content of O ions is 90.0 anion % or more,
In the glass composition expressed in atomic %, the ratio of the content of O ions to the content of P ions (O ions/P ions) is 3.15 or less,
In the glass composition expressed in mol% based on oxides,
The total content of B ₂ O ₃ and SiO ₂ (B ₂ O ₃ + SiO ₂ ) is 3.0 mol% or less,
The total content of MgO and Al ₂ O ₃ (MgO + Al ₂ O ₃ ) is 8.0 mol% or less,
the total content of Li ₂ O, Na ₂ O and K ₂ O (Li ₂ O + Na ₂ O + K ₂ O) is 15 mol% or less;
Equation 4 below:
(Formula 4)
A ₂ = {O(P)−O(others)}×C
A ₂ calculated by is 700 or more,
In the above formula 4,
C is the CuO content per molar volume of the 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) indicates the amount of oxygen excluding the O (P) from the amount of oxygen constituting the oxide of the main cation in the oxide-based glass composition,
Near-infrared absorbing glass (hereinafter also referred to as “glass 4”)
Regarding.

Further, one aspect of the present invention is
Main 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 Including 4 or more types,
containing P ions, Ba ions and Cu ions as essential cations,
In the glass composition expressed in anion %, the content of O ions is 90.0 anion % or more,
In the glass composition expressed in atomic %, the ratio of the content of O ions to the content of P ions (O ions/P ions) is 3.15 or less,
In the glass composition expressed in mol% based on oxides,
The total content of B ₂ O ₃ and SiO ₂ (B ₂ O ₃ + SiO ₂ ) is 3.0 mol% or less,
The total content of MgO and Al ₂ O ₃ (MgO + Al ₂ O ₃ ) is 8.0 mol% or less,
the total content of Li ₂ O, Na ₂ O and K ₂ O (Li ₂ O + Na ₂ O + K ₂ O) is 15 mol% or less;
CuO content is α ₂ % or more,
α2 is represented by the following formula ₅ :
(Formula 5)
α ₂ =76522×exp(−2.855×R)
is a value calculated by
In the above formula 5,
R is the above ratio (O ion / P ion),
Near-infrared absorbing glass (hereinafter also referred to as “glass 5”)
Regarding.

Further, one aspect of the present invention is
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; Including 4 or more types,
containing P ions, Ba ions and Cu ions as essential cations,
In the glass composition expressed in anion %, the content of O ions is 90.0 anion % or more,
In the glass composition expressed in atomic %, the ratio of the content of O ions to the content of P ions (O ions/P ions) is 3.15 or less,
In the glass composition expressed in mol% based on oxides,
The total content of B ₂ O ₃ and SiO ₂ (B ₂ O ₃ + SiO ₂ ) is 3.0 mol% or less,
The total content of MgO and Al ₂ O ₃ (MgO + Al ₂ O ₃ ) is 8.0 mol% or less,
the total content of Li ₂ O, Na ₂ O and K ₂ O (Li ₂ O + Na ₂ O + K ₂ O) is 15 mol% or less;
Equation 6 below:
(Formula 6)
C-3478×exp(-2.278×R)≧0
The filling,
In the above formula 6,
C is the CuO content per molar volume of the glass (unit: millimoles/cc),
R is the above ratio (O ion / P ion),
Near-infrared absorbing glass (hereinafter also referred to as “glass 6”)
Regarding.

Further, one aspect of the present invention is
In the glass composition expressed in mol% based on oxides,
P ₂ O ₅ content is 40.0 to 65.0 mol%,
CuO content is 9.0 to 25.0 mol%,
BaO content is 5.0 to 50.0 mol%,
the total content of Li ₂ O, Na ₂ O and K ₂ O (Li ₂ O + Na ₂ O + K ₂ O) is 1.0 to 15.0 mol%;
_SiO2 content not more than 2.0 mol%,
B ₂ O ₃ content is 2.0 mol% or less,
Al ₂ O ₃ content is 0.5 to 7.0 mol% or less,
Li ₂ O 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 the 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 %, the ratio of the content of O ions to the content of P ions (O ions/P ions) is 3.50 or less,
In the glass composition expressed in anion %, the F ion content is 10.0 anion % or less,
Near-infrared absorbing glass (hereinafter also referred to as “glass 7”)
Regarding.

Further, one aspect of the present invention is
Transmittance with a thickness of 0.25 mm or less and an external transmittance of 75% or more at a wavelength of 400 nm and 7% or less at a wavelength of 1200 nm when converted to a thickness at which the external transmittance is 50% at a wavelength of 620 to 650 nm. near-infrared absorbing glass (hereinafter also referred to as “glass 8”) having thermal coefficient characteristics and an average linear expansion coefficient of 135×10 ⁻⁷ /K or less at 100 to 300 ° C.
Regarding.

According to one aspect of the present invention, 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 is capable of suppressing deterioration in weather resistance. can provide. 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.

An example of spectral transmission characteristics of near-infrared absorbing glass is shown. Appearance photographs of glasses of Examples 1-1 to 1-4 are shown. 1 shows a graph plotting the T400 value against the amount of Sb ₂ O ₃ for the glasses of Example 1 and Examples 1-1 to 1-4. Appearance photographs of glasses of Examples 4-1 to 4-4 are shown. 4 shows a graph plotting the T400 value against the amount of Sb ₂ O ₃ for the glasses of Example 4 and Examples 4-1 to 4-4. Appearance photographs of glasses of Examples 25-1 to 25-4 are shown. Fig. 2 shows a graph plotting the T400 value against the amount of Sb ₂ O ₃ for the glasses of Example 25 and Examples 25-1 to 25-4.

[Near-infrared absorption glass]
Hereinafter, the glasses 1 to 8 are collectively referred to simply as "glass" or "near-infrared absorbing glass". References to glass compositions and physical properties apply to all glasses 1-8 unless otherwise specified.

In the present invention and in this specification, near-infrared absorbing glass is glass that has the property of absorbing at least all or part of the near-infrared wavelength region (700 to 1200 nm wavelength). Further, the near-infrared absorbing glass according to one aspect of the present invention can contain O ions as constituent ions, and thus can be oxide glass. Oxide glasses are glasses in which the main network-forming component of the glass is an oxide. Further, the near-infrared absorbing glass according to one aspect of the present invention can contain P ions (cations) as well as O ions (anions) as constituent ions, and therefore can be phosphate glass. Note that O ions are anions of oxygen atoms and are generally called oxide ions.

The glasses 1 to 8 are described in more detail below.

<Glass composition>
(analysis method)
The various components that make up the glass are analyzed by known methods such as inductively coupled plasma atomic emission spectrometry (ICP-AES), inductively coupled plasma mass spectrometry (ICP-MS), and the like. Amounts (mass % of elements) can be quantified.
The anion component contained in the glass can be identified and quantified by a known analysis method such as ion chromatography, non-dispersive infrared absorption spectroscopy (ND-IR), or the like.
In the present invention and this specification, the content of a component is 0%, or it does not contain or is not introduced means that this component is not substantially included, and this component is at the level of unavoidable impurities. Inclusion is allowed.

(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 oxide-based glass composition can be calculated. A specific method is as follows.
By dividing the content of the element i (mass % P _i of the element) obtained by the above analysis method by the atomic weight M _i of the element i, the number of moles n _i =P _i /M _i of each element is obtained.
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 the 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 the O ion, the corresponding number of moles n _i of the above element is hereinafter referred to as _mi .
The content PA _i (mol%) of the cationic component A _i as the oxide A _i xOy in the oxide-based glass composition is
PA _i =n′ _i /(Σn′ _i +Σm _i )×100
is represented by The content in the oxide-based glass composition can also be referred to as an oxide-based fraction.

In the oxide-based glass composition, the oxide-based fraction PB _i (mol%) of the anion component B _i other than O ions is
PB _i =m _i /(Σn′ _i +Σm _i )×100
is represented by

Here, Σn′ _i is the total number of moles of cationic component oxides A _i xOy contained in the glass. However, depending on the effective figure of the content, ignoring a trace component does not affect the calculation result.

(anion%)
"Anion %" is a value calculated by "(content of anion i of interest in mol%) / (total number of anions contained in glass in mol%) x 100", and is a value of interest. It means the molar percentage of the amount of anions to the total amount of anions.
The anion % of O ions based on the description of the notation of the glass composition based on the oxide above is
The composition formula of the oxide of the cation component A _i corresponding to the element i is represented by A _i xOy, and the number of O contained in the oxide of the cation component A _i is expressed as the oxide-based fraction PA _i of the cation component A _i (mol %), where O _i =PA _i ×y and the valence of the anion component B _k is N _k , (ΣO _i −Σ(N _k /2)B _k )/(ΣO _i −Σ ( _Nk /2)Bk _{+ ΣBk} )×100
can be calculated as
Here, ΣO _i is the total number of moles of O ions in the oxide-based glass composition, and Σ(N _k /2)B _k is the number of moles of O ions substituted by the anion component B _k . The numerator of the formula (ΣO _i −Σ(N _k /2)B _k ) is the number of moles of O ions contained in the glass.
On the other hand, in the present invention and this specification, when no anion components other than oxygen are detected by analysis by a known method, all of the anion components (that is, 100 anion%) are O ions. Assume that there is

(cation component)
For the valence of the cation component, the formal valence of each cation is used. The formal valence is the valence required for the oxide to maintain electrical neutrality when the valence of the O ion that constitutes the oxide is -2 for the oxide of the cation of interest. It can be determined uniquely from the chemical formula of the substance.
For example, Cu ions have a valence of +2 in order to maintain electrical neutrality between Cu and O ²⁻ included in the chemical formula of oxide CuO. Also, for P ions, for example, the valence of P is +2×5/2=+5 in order to maintain electrical neutrality between O ²⁻ and P included in the chemical formula of oxide P ₂ O ₅ . Generalizing this, the formal valence 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 valence of cations.
The valence of the anion (for example, the valence of the O ion is -2) is also a formal valence based on the idea that the O ion accepts two electrons and forms a closed-shell structure. Therefore, when analyzing the glass composition, it is not necessary to analyze the valence of the anion. Also, part of Cu ²⁺ can become Cu ⁺ during melting, but the amount is usually small, so the valence of Cu may be all +2.

<Glass 1-6>
(anion component)
Glasses 1 to 6 contain at least O ions as anions, and the content thereof is 90.0 anion % or more in the glass composition represented by anion %. By lowering the O/P ratio in a glass mainly composed of O ions as anions in this way, the absorption of CuO in the red region can be shifted to the longer wavelength side, thereby reducing the transmittance in the red region. The present inventor believes that it is possible to improve the near-infrared cut ability by increasing the content of CuO without the need for a high content. In glasses 1 to 6, the O ion content in the glass composition expressed by anion % is 90.0% or more, preferably 95.0% or more, more preferably 98.0% or more, More preferably, it is 99.0% or more. A high proportion of O ions in the anion component is also preferable for suppressing volatilization during melting of the glass. Suppressing the volatilization during melting of the glass is preferable from the viewpoint of suppressing the generation of striae. In particular, the content of O ions is preferably 100% from the viewpoint of suppressing volatilization during melting of the glass, enhancing productivity, and suppressing the generation of harmful gases during production. The formal valence of O ions is -2.

Glasses 1 to 6 can contain only O ions as anions in one form, and can contain one or more other anions in addition to O ions in another form. Other anions include F ions, Cl ions, Br ions, I ions, and the like. The formal valence of F ions, Cl ions, Br ions, and I ions is −1.

The content of F ions is preferably 15.0 anion % or less, more preferably 10.0 anion % or less in the glass composition expressed in anion %, from the viewpoint of improving the homogeneity and strength of the glass. , 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, glasses 1 to 6 may be glass containing no F ions, from the viewpoint of suppressing volatilization during glass melting, enhancing productivity, and suppressing the generation of harmful gases during production.

(O/P ratio)
In the glass composition expressed in atomic %, the ratio of the cation content and the anion content is the content of the components of interest when the total amount of all cationic components and all anionic components is 100 atomic % display). Therefore, the ratio of the content of O ions to the content of P ions (O ions/P ions) is the content of P ions ( It is the ratio of the content of O ions (in atomic %) to the content in atomic %.

O/P ratio calculation method 1
A method for calculating the O/P ratio (also referred to as R) will be described by taking a glass having the following composition as an oxide-based glass composition as an example.
_P2O5 : 52.6 mol, _Al2O3 : _2.6 mol, _K2O : _2.7 mol, BaO: 21.6 mol, ZnO: 4.2 mol, CuO: 16.3 mol.
The number of O included in the molecular formula is 5 for P ₂ O ₅ , 3 for Al ₂ O ₃ , 1 for K ₂ O, 1 for BaO, 1 for ZnO, and 1 for CuO.
The number of moles of O contained 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 4.2 for CuO. 16.3.
The O/P ratio of the glasses in the above examples can be determined as follows.
Obtain the number N _S of O ions in the molecular formula of glass: 52.6P ₂ O ₅ -2.6Al ₂ O ₃ -2.7K ₂ O-21.6BaO-4.2ZnO-16.3CuO. The molecular formula of glass is a compositional formula of glass indicated so 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 (P ₂ O ₅ : 5, Al ₂ O ₃ : 3, K ₂ O : 1, BaO: 1, ZnO: 1, CuO: 1) hand,
N _S =52.6×5+2.6×3+2.7×1+21.6×1+4.2×1+16.3×1=315.7
Calculate Ns as
The glass of the above example has zero O ions substituted with other _anions in the molecular _formula of the glass. By dividing by x2, O/P ratio = 315.7/(52.6 x 2) = 3.00 is obtained.

O/P ratio calculation method 2
When one or more other anion components are detected in addition to oxygen by analysis by a known method, the oxygen content includes (1) the valence of the cationic component contained in the glass and the mole % of the element. The content (unit : anion %) can be employed.
That is, from the results of identification and quantitative analysis by known methods,
(1) Regarding the cation component contained in the glass, "the cation content based on the number y of oxygen per cation and the number x of cations in the oxide MxOy, based on the number of oxygen per cation y/x x mol% of the element ” is calculated.
(2) Regarding anion components other than oxygen, from the results of identification and quantitative analysis by a known method and the valence z of the anion, "content of anion based on mol% of element x substituted per anion Calculate the total V of the oxygen number z/2".
(3) UV can also be employed as the content of O ions relative to the content of P ions.

As calculation examples of calculation method 2, calculation examples 1 and 2 are shown below.

Calculation Example 1: When the molar percentages of the elements of P ions, Li ions, and Cu ions are quantified as 22.0, 8.0, and 5.5 (contents in mol% of the elements), the corresponding oxides: Since y/x of P ₂ O ₅ , Li ₂ O, and CuO are 2.5, 0.5, and 1.0, respectively,
U = 22 x 2.5 + 8 x 0.5 + 5.5 x 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 in mol % of the element).
O/P ratio=64.5/22=2.93 .

Calculation Example 2: P ions, Li ions, and Cu ions have molar percentages of 22.0, 8.0, and 5.5 (contents expressed in mol % of the elements), and F ions have a molar percentage of 4.0. 0 (content in mol % of element), the corresponding oxides: P2O5, Li2O, CuO have y/ _x of _2.5 , _0.5 and 1.0, respectively. , and the valence of F is −1, so
U = 22 x 2.5 + 8 x 0.5 + 5.5 x 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 in mol % of the element).
O/P ratio=62.5/22=2.84 .

In glasses 1 to 6, from the viewpoint of improving both the transmittance in the visible region and the near-infrared cutting ability, and from the viewpoint of improving the thermal stability of the glass, the content of P ions in the glass composition expressed in atomic % The content ratio of O ions to the (O/P ratio) is 3.15 or less.
In glass 1 to glass 6, the O/P ratio is preferably 3.14 or less, 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 the weather resistance and/or suppressing the deterioration of the meltability, it is preferable that the O/P ratio in the glasses 1 to 6 is large. From this point, in the glass 1 to glass 6, the O / P ratio is preferably 2.85 or more, 2.86 or more, 2.87 or more, 2.88 or more, 2.89 or more, 2.90 The above is more preferable in the order of 3.00 or more.

(cation component)
Glasses 1-6 are 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 four or more main cations selected from and contains P ions, Ba ions and Cu ions as essential cations. In one form, the total content of oxides of the major cations can be 90.0% or more in the oxide-based glass compositions (expressed in mol %) of glasses 1-6.
In glasses 1 to 6, if the total content of oxides of the main cations is 90.0% or more, it can contribute to improving the thermal stability of the glass and / or prevent striae, volatilization, etc. Suppression can contribute to improving the optical homogeneity of the glass. From the above points, the total content of oxides of the main cations in glasses 1 to 6 is preferably 92.0% or more, 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, 99.6% or more, in that order, and can be 100%. In one form, the total content of oxides of the main cations in glasses 1-6 is 100% or less, or 99.5% or less, 99% or less, 98.5% or less, 98.0% or less, 97.5% % or less.

Hereinafter, the content of the cationic component will be described as the content in the glass composition based on oxides (indicated by mol %).

Glasses 1-6 contain Cu ions as essential cations, since CuO is an essential component for imparting near-infrared cutting ability to glasses.

In glass 1, the CuO content is α ₁ % or more. α ₁ is a value calculated by Equation 1 below.

(Formula 1)
α ₁ =70400×exp(−2.855×R)

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

As for the glass 2, the lower limit of the CuO content is defined by the following formula 2 based on the CuO content per molar volume of the glass.

(Formula 2)
C-3200×exp(-2.278×R)≧0

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

In Formula 2, the above C is obtained by the following method.
C is the mass equivalent to 1 mol of the glass composition, that is, the molar molecular weight M (g / mol) and the molar volume M/D (unit: cc/mol) of the glass,
C=mol % of CuO/(M/D)×1000 (unit: millimole/cc)
can be calculated as
The molar molecular weight M is
Based on the explanation of the notation of the glass composition based on the oxide above, when the formula weight MA _i of the oxide corresponding to the above cation component Ai, the atomic weight of the anion component _Bk is _MBk , and 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
can be obtained as
For example, the glass composition is composed of s mol % A ₂ O component based on oxide, t mol % BO component based on oxide, and u mol % F component, s + t + u = 100 (%), A ₂ The formula weight of the O 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), and the atomic weight of _oxygen is MO (g/mol ), when
M = (s x M _A + t x M _B + u x M _F - u/2 x M _O )/(s + t)
becomes.
For example, the oxide-based glass composition is P ₂ O ₅ : 52.6 mol %, Al ₂ O ₃ : 2.6 mol (g/mol), K ₂ O: 2.7 mol (g/mol), Taking a glass of BaO: 21.6 mol (g/mol), ZnO: 4.2 mol (g/mol), and CuO: 16.3 mol (g/mol) as an example, a method for calculating the molar molecular weight M will be described. .
Formula weight of P2O5: _{141.94 (} g/mol)
Formula weight of _Al2O3 : _101.96 (g/mol)
Formula weight of K2O: 94.2 ₍ g/mol)
Formula weight of BaO: 153.3 (g/mol)
ZnO formula weight 81.4 (g/mol)
CuO formula weight 79.55 (g/mol)
Using .6+2.7+21.6+4.2+16.3)=129.36 (g/mol).

As a result of extensive studies, the present inventors found that when the O/P ratio is reduced in a glass mainly composed of O ions as anions, the absorption of CuO in the red region shifts to the longer wavelength side, resulting in the transmittance of the red region. It was newly found that the CuO content can be increased while suppressing the decrease in the . Furthermore, the present inventors have newly found that there is a good correlation between the O / P ratio and the CuO content for achieving a prescribed half value at a prescribed wall thickness, and the O / P ratio is in the range described above. The lower limit of the CuO content (α ₁ , α ₂ ) was defined by Equation 1 for Glass 1 and by Equation 5 for Glass 5. Further, the CuO content per molar volume of the glass was defined by Equation 2 for glasses having an O/P ratio within the range described above, and by Equation 6 for Glass 6.

In the glass 3, the CuO content is defined based on A1 calculated by the following formula ₃ , and A1 is 2500 or _more .

(Formula 3)
A ₁ = {O(P)−O(others)}×Cu

In formula 3, O(P) indicates the amount of oxygen that constitutes the oxide of P ions in the oxide-based glass composition, and O(others) is shown ahead of glass 3 in the oxide-based glass composition. It shows the amount of oxygen obtained by excluding the above O(P) from the amount of oxygen constituting the oxide of the main cation, and Cu indicates the CuO content in mol % in the oxide-based glass composition.

“O(P)” in Equation 3 is calculated as follows.
When the P ₂ O ₅ content in the oxide-based glass composition (expressed as mol %) is M mol %, the number of oxygen atoms contained in the chemical formula of P ₂ O ₅ : 5 is used, and O (P) is " O(P)=M×5”.
Similarly, for main cations other than P ions, the content value as an oxide in the oxide-based glass composition (mol% display) and the oxides formed by each cation in the state of formal valence are included. The number of oxygens is used to calculate the amount of oxygen that makes up the oxide of each cation.
“O(others)” is calculated as a value obtained by subtracting O(P) from the total amount of oxygen calculated for the oxides of the main cations.
When the CuO content in the oxide-based glass composition (expressed as mol %) is N mol %, “A” is calculated as A ₁ ={O(P)−O(others)}×N.

As described above, when the O/P ratio is decreased in a glass mainly composed of O ions as anions, the absorption of CuO in the red region shifts to the longer wavelength side, thereby suppressing the decrease in the transmittance in the red region while suppressing the decrease in the transmittance of CuO. The present inventor has newly found that the content can be increased. Furthermore, by configuring the chemical species other than PO that is coordinated to CuO with a chemical species that has a smaller ionic radius and a lower valence, the following 1) and 2) result in a visible region (purple region A new finding was also obtained that the transmittance in the red region) can be increased. For glass 3, the CuO content is defined based on A calculated by Equation 3 based on this finding.
1) Transmittance in the red region can be increased by increasing the wavelength of absorption derived from Cu ²⁺ .
2) By making it possible to bring the glass into a liquid state at a low temperature, it is possible to suppress the generation of Cu ⁺ which causes absorption in the violet region around 400 nm wavelength.

Regarding the glass ₃ , A1 is 2500 or more, preferably 2800 or more, 2900 or more, 3000 or more, 3100 or more, 3200 or more, from the viewpoint of improving both the transmittance in the visible region and the near-infrared cutting ability. , 3300 or more, 3400 or more, 3500 or more, 3600 or more, 3700 or more, 3800 or more, 3900 or more, 4000 or more, 4100 or more, 4200 or more, 4300 or more, 4400 or more, 4500 or more, 4600 or more, 4700 or more, 4800 or more, 4900 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, 6500 or more order is more preferred. On the other hand, the thermal stability of the glass is reduced due to a large amount of Cu and O, the transmittance is reduced at the desired half-value wavelength, and/or the thermal stability of the glass is reduced due to an excessive amount of O (others). From the viewpoint of further suppressing deterioration of properties or deterioration of weather resistance, A is preferably 20000 or less, 19000 or less, 18000 or less, 17000 or less, 16000 or less, 150000 or less, 14000 or less, 13000 or less, 12000 or less. , 11000 or less, 10000 or less, 9000 or less, or 8000 or less. It should be noted that there tends to be a preference for a large value for this value in order to achieve the desired half value with a smaller wall thickness.

In the glass 4, the CuO content is defined based on _A2 calculated by the following formula 4, and _A2 is 700 or more.

(Formula 4)
A ₂ = {O(P)−O(others)}×C

In Equation 4, C is the CuO content per molar volume of the glass (unit: millimoles/cc). O(P) indicates the amount of oxygen that constitutes the oxide of P ion in the oxide-based glass composition, and O(others) is the amount of oxygen that constitutes the oxide of the main cation in the oxide-based glass composition. is the amount of oxygen excluding the above O(P).

Regarding the glass 4, _A2 is 700 or more, preferably 800 or more, 850 or more, 890 or more, 1000 or more, 1100 or more, from the viewpoint of improving both the transmittance in the visible region and the ability to cut near-infrared rays. , 1200 or more, 1300 or more, 1400 or more, 1500 or more, 1600 or more, 1700 or more, 1800 or more, in this order. On the other hand, the thermal stability of the glass is reduced due to a large amount of Cu and O, the transmittance is reduced at the desired half-value wavelength, and/or the thermal stability of the glass is reduced due to an excessive amount of O (others). _A2 is preferably 5000 or less, more preferably 4000 or less, 3500 or less, 3000 or less, 2500 or less, or 2000 or less, from the viewpoint of further suppressing deterioration of properties or weather resistance. It should be noted that there tends to be a preference for this numerical value to be large in order to achieve the desired half transmittance with a thinner wall thickness.

Also, in the glass 5, the CuO content is α ₂ % or more. α2 is a value calculated from Equation ₅ below.

(Formula 5)
α ₂ =76522×exp(−2.855×R)

In Equation 5, R is the O/P ratio.

As for the glass 6, the lower limit of the CuO content is defined by the following formula 6 based on the CuO content per molar volume of the glass.

(Formula 6)
C-3478×exp(-2.278×R)≧0

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

The CuO content of glasses 1 to 6 is preferably 4.0% or more, 5.0% or more, 6.0% or more, and 7.0% in terms of oxide-based glass composition (mol% display). 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% The above and 20.0% or more are more preferable in that order. The CuO content is preferably 48.0% or less, more preferably 47.0% or less and 46.0% or less, from the viewpoint of leaving room for introduction of glass-forming components and maintaining the thermal stability of the glass. % 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, 40.0% 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, in that order.

In order for the wavelength λ _T 50 at which the external transmittance including the reflection loss is 50% as a transmittance characteristic in terms of thickness of 0.16 mm to be in the range of 600 nm to 650 nm, the CuO content is the oxide standard glass composition (mol% representation), it is preferably 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 are preferred in that order.
As a transmittance characteristic in terms of thickness of 0.21 mm, the wavelength λ _T 50 at which the external transmittance including reflection loss is 50% is in the range of 600 nm to 650 nm. In the composition (mol% display), it is preferably 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.
In order for the wavelength λ _T 50 at which the external transmittance including reflection loss is 50% as a transmittance characteristic in terms of thickness of 0.25 mm to be in the range of 600 nm to 650 nm, the CuO content must be in the glass composition based on oxides. (mol% representation), it is preferably 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% 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.
On the other hand, regarding the transmittance characteristics in terms of thickness of 0.25 mm, if the CuO content is large, the wavelength λ _T 50 at which the external transmittance including reflection loss is 50% may be less than 600 nm. is preferably 35.0% or less, 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, in that order.
In order for the thickness of the glass to be 0.25 mm or less at which the wavelength λ _T 50 is 645 nm at which the external transmittance including reflection loss is 50% at a wavelength of 550 nm or more, the CuO content must be the oxide-based glass composition ( mol% display), it is preferably 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.
In order for the thickness of the glass to be 0.25 mm or less at which the wavelength λ _T 50 is 633 nm at which the external transmittance including reflection loss is 50% at a wavelength of 550 nm or more, the CuO content must be the oxide-based glass composition ( mol % display), it is 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, in that order.

In glass 2 and glass 4, the value of C is preferably 4.0 or more, more preferably 4.1 or more, and even more preferably 4.2 or more. The value of C is preferably 8.5 or less, preferably 8.0 or less, 7.5 or less, 7.0, from the viewpoint of leaving room for the introduction of glass-forming components and maintaining the thermal stability of the glass. Below, 6.5 or less, 6.0 or less, and 5.5 or less are more preferable in that order.

In glasses 1-6, the CuO content can be α ₃ % or higher. _α3 is a value calculated from Equation 7 below. In one form, for glasses 7 and 8, the CuO content can be α ₃ % or greater.

(Formula 7)
α ₃ = (70400 x 0.25/d) x exp (-2.855 x R)

In Equation 7, R is the O/P ratio. d can take a value greater than 0 and less than or equal to 0.25. For example, d is 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, and so on. However, the value of d is not limited to these. Small values of d tend to be preferred in order to achieve the desired half-transmittance at lower wall thicknesses.

For example, when d=0.11, the CuO content can be greater than or equal to α ₃ %, where α ₃ is calculated by the following equation.
α ₃ =(70400×0.25/0.11)×exp(−2.855×R)

When the plate thickness of the glass is D (mm) when the external transmittance of the glass for light with a wavelength of 633 nm is 50%, in one form, d=D in the formula 7 above. _In this case, α3 is calculated by the following formula.
α ₃ = (70400 x 0.25/D) x exp (-2.855 x R)

For glasses 1-6, the lower limit of the CuO content can also be the value defined by Equation 8 below in terms of the CuO content per molar volume of the glass.

(Formula 8)
C-3200 x 0.25/d x exp (-2.855 x R) ≥ 0

In Formula 8, d can take a value greater than 0 and less than or equal to 0.25. For example, d is 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, and so on. However, the value of d is not limited to these. Small values of d tend to be preferred in order to achieve the desired half-transmittance at lower wall thicknesses.

For example, when d=0.11, Equation 8 is the following equation.
C-3300×0.25/0.11×exp(-2.855×R)≧0

When the thickness of the glass is D (mm) when the external transmittance of the glass for light with a wavelength of 633 nm is 50%, in one form, d=D in Equation 8 above. In this case, Equation 8 is the following equation.

With respect to CuO content, each of glasses 1-6 can also satisfy one or more provisions of the equations for the other glasses.

Glasses 1-6 contain P ions as essential cations. As described above, it is preferable that the O/P ratio is low from the viewpoint of achieving both an improvement in the transmittance in the visible region and an improvement in the ability to cut near-infrared rays. _In order to reduce the O/P ratio, it is preferable to increase the _P2O5 content. From this point, the P ₂ O ₅ content in the oxide-based glass composition (expressed as mol %) is preferably 33.0% or more, 34.0% or more, 35.0% or more, 36.0% or more, % 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, 50.0% or more, in this order, more preferable . Since P ₂ O ₅ itself is a component that does not have near-infrared absorption ability, from the viewpoint of increasing the content of CuO having near-infrared absorption ability, the P ₂ O ₅ content should be 72.0% or less. is preferably 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 0.5% or less, 62.0% or less, 61.5% or less, 61.0% or less, 60.5% or less, and 60.0% or less, in that order. In addition, it is preferable that the P ₂ O ₅ content is equal to or less than the above value from the viewpoint of further suppressing deterioration of weather resistance and/or from the viewpoint of suppressing deterioration of meltability.

Glasses 1-6 preferably have an oxide-based glass composition consisting primarily of P ₂ O ₅ , BaO and CuO to obtain the desired transmittance properties. From this point, the total content of P ₂ O ₅ , BaO and CuO (P ₂ O ₅ +BaO + CuO) is preferably 70.0% or more, 75.0% or more, 80.0% or more, 85.0% or more. The order of 0% or more is more preferable. Glasses 1 to 6 contain P ions, Ba ions and Cu ions as essential cations, and one or more selected from the group of major cations in order to obtain thermal stability and/or chemical durability of glass. further includes a cation of Therefore, the total content (P ₂ O ₅ + BaO + CuO) is less than 100%, preferably 99.0% or less, 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.

In one embodiment, P ₂ O ₅ , _BaO and The total content of CuO (P ₂ O ₅ + BaO + CuO) is preferably 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 are preferred in that order.
In order for the wavelength λ _T 50 at which the external transmittance including reflection loss is 50% to be in the range of 600 nm to 650 nm as the transmittance characteristic in terms of thickness of 0.21 mm, the total content of P ₂ O _5, BaO and CuO is required. The amount (P ₂ O ₅ + BaO + CuO) is preferably 80.0% or more, 81.0% or more, 82.0% or more, or 83.0% in the oxide-based glass composition (mol% display). 84.0% or more, 85.0% or more, 86.0% or more, 87.0% or more, 88.0% or more, 89.0% or more, 90.0% or more, in that order.
In order for the wavelength λ _T 50 at which the external transmittance including the reflection loss is 50% to be in the range of 600 nm to 650 nm as the transmittance characteristic in terms of the thickness of 0.25 mm, the total content of P ₂ O ₅ , BaO and CuO is The amount (P ₂ O ₅ + BaO + CuO) is preferably 75.0% or more, 76.0% or more, 77.0% or more, or 78.0% in the oxide-based glass composition (mol% display). 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 are preferred in that order.
In order for the thickness of the glass to be 0.25 mm or less at which the wavelength λ _T 50 is 645 nm at which the external transmittance including reflection loss is 50% at a wavelength of 550 nm or more, the sum of P ₂ O ₅ , BaO and CuO The content (P ₂ O ₅ +BaO + CuO) is preferably 80.0% or more, 81.0% or more, 82.0% or more, and 83.0% in the oxide-based glass composition (mol% display). % 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 order for the thickness of the glass to be 0.25 mm or less, the total content of P ₂ O ₅ , BaO and _CuO is (P ₂ O ₅ + BaO + CuO) is preferably 81.0% or more, 82.0% or more, 83.0% or more, 84.0% or more in the oxide-based glass composition (mol% display) , 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.

On the other hand, as another form, the total content of MgO, CaO, SrO, BaO and ZnO (MgO + CaO + SrO + BaO + ZnO) with respect to the total content of Li ₂ O, Na ₂ O and K ₂ O (Li ₂ O + Na ₂ O + K ₂ O) For glass having a molar ratio ((MgO+CaO+SrO+BaO+ZnO)/(Li ₂ O+Na ₂ O+K ₂ O)) of 2.0 or more, the external transmittance including reflection loss is 50% as a transmittance characteristic converted to a thickness of 0.16 mm. In order for the wavelength λ _T 50 to be in the range of 600 nm to 650 nm, the total content of P ₂ O ₅ , BaO and CuO (P ₂ O ₅ +BaO + CuO) is It is preferably 65.0% or more, and more preferably 66.0% or more, 67.0% or more, 68.0% or more, 69.0% or more, and 70.0% or more in this order.
Regarding the above-described other embodiment, in order for the wavelength λ _T 50 at which the external transmittance including the reflection loss is 50% to be in the range of 600 nm to 650 nm as the transmittance characteristic in terms of the thickness of 0.21 mm, P ₂ O ₅ , the total content of BaO and CuO (P ₂ O ₅ +BaO + CuO) is preferably 60.0% or more, 61.0% or more, The order of 0% or more, 63.0% or more, 64.0% or more, and 65.0% or more is more preferable.
Regarding the other embodiment, in order for the wavelength λ _T 50 at which the external transmittance including the reflection loss is 50% to be in the range of 600 nm to 650 nm as a transmittance characteristic in terms of a thickness of 0.25 mm, P ₂ O ₅ , the total content of BaO and CuO (P ₂ O ₅ +BaO + CuO) is preferably 55.0% or more, 56.0% or more, 0% or more, 58.0% or more, 59.0% or more, and 60.0% or more are preferred in that order.
Regarding the above-described another embodiment, in order for the thickness of the glass to be 0.25 mm or less at which the wavelength λ _T 50 is 645 nm at which the external transmittance including reflection loss is 50% at a wavelength of 550 nm or more, P ₂ The total content of O ₅ , BaO and CuO (P ₂ O ₅ + BaO + CuO) is preferably 60.0% or more, 61.0% or more, 62 0% or more, 63.0% or more, 64.0% or more, and 65.0% or more, in that order.
Regarding the above-described other embodiment, in order that the thickness of the glass at which the wavelength λ _T 50 is 633 nm at which the external transmittance including reflection loss is 50% at a wavelength of 550 nm or more is 0.25 mm or less, P ₂ O ₅ , BaO and CuO (P ₂ O ₅ +BaO + CuO) is preferably 61.0% or more, 62.0% or more, 63.0% or more in the oxide-based glass composition (mol% display). 0% or more, 64.0% or more, 65.0% or more, and 66.0% or more are preferred in that order.

Glasses 1 to 6 are, in one form, one or more of B ions and Si ions that tend to shift the half value to the short wavelength side from the viewpoint of increasing the near-infrared cutting ability of the glass and improving the transmittance in the visible region. It can be a glass that contains both, and in another form, it can be a glass that contains neither B ions nor Si ions.

For glasses 1 to 6, the total content of B ₂ O ₃ and SiO ₂ (B ₂ O ₃ +SiO ₂ ) is preferably 3.0% or less, 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.

In glasses 1-6, the total content of B ₂ O ₃ and SiO ₂ (B ₂ O ₃ +SiO ₂ ) can be 0%, 0% or more, or more than 0%.

In glasses 1 to 6, the content of B ₂ O ₃ is preferably 3.0% or less, 2.5% or less, 2.0% or less, from the viewpoint of further improving the transmittance in the visible region. , 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, for glasses 1 to 6, when rough melting of the glass is performed in a quartz crucible in order to promote homogenization of the glass, the SiO ₂ content is preferably greater than 0%, 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, in that order. However, the introduction of excess _SiO2 into the glass tends to degrade the optical homogeneity of the glass. From this point, in glasses 1 to 6, the SiO ₂ content is preferably 2.0% or less, 1.4% or less, 0.9% or less, 0.8% or less, 0.6% or less. , 0.4% or less.

Glasses 1-6 contain Li ions in one form and do not contain Li ions in another form. Li ₂ O has a high ability to maintain the absorption of CuO in the long wavelength region and has a small adverse effect on weather resistance as compared with various glass components. From this point of view, the Li ₂ O content can be 0% or more or more than 0%, preferably 0.1% or more, 0.5% or more, 1.0% or more, 1.2% or more. % or more is preferable. On the other hand, the Li ₂ O content is preferably 13.0% or less from the viewpoint of ensuring the thermal stability of the glass and/or from the viewpoint of further suppressing deterioration of weather resistance. 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% 3.0% or less, and then 2.8% or less, in that order. A Li ₂ O content of 7.0% or less is preferable from the viewpoint of suppressing deliquescence of the glass.

In glasses 1 to 6, the total content of MgO and Al ₂ O ₃ (MgO + Al ₂ O ₃ ) is 8.0% or less from the viewpoint of improving meltability, improving transmittance in the visible region, and improving near-infrared absorption characteristics. is preferably 7.5% or less, 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, 1. The order of 4% or less is more preferable, and 0% is also possible. On the other hand, the total content of MgO and Al ₂ O ₃ (MgO + Al ₂ O ₃ ) can be more than 0% from the viewpoint of improving the weather resistance of the glass and improving the mechanical strength of the glass. It is preferably 0.1% or more, 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, in that order.

In glasses 1 to 6, Al ₂ O ₃ is a component that can contribute to particularly improving weather resistance. The Al ₂ O ₃ content can be 0%, 0% or more, or more than 0%, and from the viewpoint of improving weather resistance, it is preferably 0.1% or more, .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, 1.2% or more, in this order, more preferable . On the other hand, from the viewpoint of further suppressing the decrease in transmittance in the visible region, the Al ₂ O ₃ content is preferably 6.0% or less, 5.5% or less, 5.0% or less, and 4.5% or less. 5% or less, 4.0% or less, 3.5% or less, 3.0% or less, and 2.8% or less are preferred in that order. In one form, the improvement of the near-infrared absorption characteristics is prioritized over the maintenance of the weather resistance of the glass, and by suppressing the shift of the absorption of CuO to the short wavelength side, the transmittance in the visible region is further increased, and the near-infrared absorption characteristics are improved. From the viewpoint of improvement, the Al ₂ O ₃ content is preferably less than 2.0%. 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% 0.6% or less and then 0.5% or less are more preferable in that order.

In glasses 1 to 6, MgO is a component that can be added as appropriate for the reason of adjusting the thermal stability of the glass. It tends to make it difficult to increase the CuO content. Also, the meltability of the glass tends to decrease as the MgO content increases. From these viewpoints, the MgO content is 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, and 2.0% or less, in that order. The MgO content can also be 0%. In one form, from the viewpoint of improving the mechanical strength of the glass, the MgO content can be more than 0%, preferably 0.5% or more, and more preferably 1.0% or more. .

La ₂ O ₃ is a component that can contribute to enhancing the weather resistance without impairing the near-infrared absorption properties of the glass. The La ₂ O ₃ content is preferably 0.10% or more, more preferably 0.15% or more, 0.18% or more, and 0.21% or more in this order. On the other hand, from the viewpoint of further suppressing the decrease in transmittance in the visible region, the La ₂ O ₃ content is preferably 8.0% or less, 7.0% or less, 6.5% or less. 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% Below, 1.5% or less, and 1.0% or less are more preferable in that order. The La ₂ O ₃ content may be 0%.

Y ₂ O ₃ is also a component that can contribute to enhancing the weather resistance without impairing the near-infrared absorption properties of the glass. Y ₂ O ₃ content is preferably 0.10% or more, 0.15% or more, 0.20% or more, 0.25% or more, 0.30% or more, 0.35% or more, 0 0.40% or more, 0.45% or more, and 0.50% or more are preferred in that order. On the other hand, from the viewpoint of further suppressing the decrease in transmittance in the visible region, the Y ₂ O ₃ content is preferably 8.0% or less, 7.0% or less, 6.5% or less. 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% 1.5% or less, and then 1.0% or less, in that order. The Y ₂ O ₃ content may be 0%. Y ₂ O ₃ can also be introduced from the viewpoint of increasing the molar volume of the glass without increasing the specific gravity of the glass.

Gd ₂ O ₃ is also a component that can contribute to improving weather resistance. The Gd ₂ O ₃ content is preferably 0.10% or more, more preferably 0.15% or more, 0.18% or more, and 0.21% or more in this order. On the other hand, from the viewpoint of further suppressing the decrease in transmittance in the visible region, the content of Gd ₂ O ₃ is preferably 8.0% or less, 7.0% or less, 6.5% or less. 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% Below, 1.5% or less, and 1.0% or less are more preferable in that order. The Gd ₂ O ₃ content may be 0%.

The oxide-based glass composition may or may not contain one or more rare earth oxides other than the above, such as Lu ₂ O ₃ and Sc ₂ O ₃ . Since these components are generally expensive, the content of rare earth oxides other than La ₂ O ₃ , Y ₂ O ₃ and Gd ₂ O ₃ (if two or more are included, their total content) is 2.5 % or less, preferably 1.5% or less, 1.0%, 0.5% or less, or even 0%.

In glasses 1 to 6, the total content of Al ₂ O ₃ , La ₂ O ₃ , Y ₂ O ₃ and Gd ₂ O ₃ (Al ₂ O ₃ +La ₂ O ₃ +Y ₂ O ₃ +Gd ₂ O ₃ ) From the viewpoint of improving the properties, the content is preferably 0.1% or more, 0.15% or more, 0.20% or more, 0.25% or more, 0.30% or more, 0.35% or more, and 0.1% or more. More preferably 40% or more, 0.45% or more, and 0.50% or more in that order. On the other hand, the total content (Al ₂ O ₃ +La ₂ O ₃ +Y ₂ O ₃ +Gd ₂ O ₃ ) is 8.0% or less from the viewpoint of ensuring the thermal stability of the glass and/or lowering the melting temperature. 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; 5% or less, 3.0% or less, 2.5% or less, 2.0% or less, 1.5% or less, and 1.0% or less are preferred in that order.

In glasses 1-6, the Ba ion is the essential cation. The BaO content of glasses 1-6 can be greater than 0%. BaO is a component that can improve weather resistance by introducing a certain amount, and tends to cause less deliquescence than alkali metal oxides. Moreover, BaO can be added for the purpose of improving the thermal stability of the glass and adjusting the meltability. Furthermore, BaO can contribute to lowering T1200, but excessive introduction tends to lower T400. T1200 and T400 will be described later. From the above viewpoint, in glasses 1 to 6, the BaO content is preferably 10.0% or more, more preferably 11.0% or more. In view of the above, in glasses 1 to 6, the BaO content is preferably 23.0% or less, more preferably 22.0% or less.

SrO content is 0%. It can be greater than or equal to 0% or greater than 0%. Like BaO, SrO is a component that is relatively difficult to lower the 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. SrO content is preferably 0.5% or more, 1.0% or more, 1.5% or more, 2.0% or more, 2.5% or more, 3.0% or more, 3.5% 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 T400 tends to decrease due to excessive introduction, the SrO content is preferably 30.0% or less, 29.0% or less, 28.0% or less, 27.0% or less, 26 .0% or less, 26.0% or less, 25.0% 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, in that order.

CaO content is 0%. It can be greater than or equal to 0% or greater than 0%. CaO is a component that is relatively difficult to lower the weather resistance, and is a component that can be added as appropriate for reasons such as adjustment of the thermal stability of the glass. CaO can also be used to adjust the concentration of CuO. CaO content is preferably 0.5% or more, 1.0% or more, 1.5% or more, 2.0% or more, 2.5% or more, 3.0% or more, 3.5% Above, 4.0% or more, 4.5% or more, 5.0% or more, 5.5% or more, 6.0% or more, 6.5% or more, 7.0% or more is preferable. However, since T400 tends to decrease due to excessive introduction, the CaO content is
It is preferably 30.0% or less, 29.0% or less, 28.0% or less, 27.0% or less, 26.0% or less, 26.0% or less, 25.0% 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, in that order.

The Na ₂ O content can be 0%, greater than or equal to 0%, or greater than 0%. Excess introduction of Na ₂ O tends to lower the weather resistance. Therefore, the Na ₂ O content is preferably 5.0% or less, more preferably 4.0% or less, 3.0% or less, 2.0% or less, and 1.0% or less, in that order.

_The K2O content can be 0%, greater than or equal to 0%, or greater than 0%. Among alkali metal oxides, K ₂ O has the effect of further improving near-infrared absorption characteristics compared to Li ₂ O and Na ₂ O. On the other hand, excessive introduction of K ₂ O tends to lower the weather resistance. From these viewpoints, the K ₂ O content is preferably 10.0% or less, 9.0% or less, 8.0% or less, 7.0% or less, 6.0% or less, 5.0% or less. % or less, 4.0% or less, 3.0% or less, 2.0% or less, and 1.0% or less, in that order.

The Cs ₂ O content can be 0%, greater than or equal to 0%, or greater than 0%. Since Cs ₂ O also tends to reduce weather resistance, it is desirable not to actively introduce it. Cs ₂ O content is 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 Cs ₂ O content can be 0.5% or more, 1.0% or more, 1.5% or more, 2.0% or more. , 2.5% or more, 3.0% or more, 3.5% or more, or 4.0% or more.

The total content of Li2O, _Na2O and K2O ₍ Li2O _{+ Na2O + K2O} ) can be 0%, greater than or equal to 0% or greater than 0%. From the viewpoint of further suppressing deterioration of weather resistance, the total content (Li ₂ O + Na ₂ O + K ₂ O) is preferably 15.0% or less, 14.0% or less, 13.0% or less, The order of 12.0% or less, 11.0% or less, and 10.0% or less is more preferable. When the total content (Li ₂ O + Na ₂ O + K ₂ O) is equal to or less than the above value, the coefficient of thermal expansion increases, the amount of expansion and contraction of the glass increases, and the volume change of the glass is regulated by other members. It is also preferable from the viewpoint of avoiding chipping or cracking of the glass due to stress being applied to the glass when it is pressed.

From the viewpoint of suppressing deliquescence of the glass, the total content of Na ₂ O and K ₂ O (Na ₂ O + K ₂ O) is preferably 15.0% or less, 14.0% or less, and 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 Na ₂ O and K ₂ O (Na ₂ O+K ₂ O) can be 0%, greater than or equal to 0%, or greater than 0%. By setting the total content of Na ₂ O and K ₂ O (Na ₂ O+K ₂ O) to 0%, it is possible to obtain a glass in which deliquescence is further suppressed. On the other hand, the total content (Na ₂ O + K ₂ O) can be 1.0% or more from the viewpoint of suppressing the glass raw material cost while suppressing the meltability of the glass and suppressing the decrease in T600. , 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, or 15.0% or more.

As for the weather resistance, one or both of suppression of deliquescence of the glass and suppression of the generation of precipitates on the glass surface under high temperature and high humidity conditions can be used as indicators of the weather resistance. This point will be further described later. In order to further improve weather resistance, the introduction of Al ₂ O ₃ is more preferred, followed by the introduction of one or more of Y ₂ O ₃ , La ₂ O ₃ and Gd ₂ O ₃ . _In addition, BaO can improve the weather resistance by introducing a relatively large amount _, and _SrO and CaO need to be introduced in a larger amount from the viewpoint of improving weather resistance. O ₃ +La ₂ O ₃ +Gd ₂ O ₃ +BaO/3+(CaO+SrO)/6)” (unit: mol %) is preferably 0% or more, more preferably more than 0%. 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, 8.0% or more is preferable. Furthermore, when the weather resistance and mechanical strength of the glass are emphasized, the , 15.0% or more, 16.0% or more, 17.0% or more, 18.0% or more, and 19.0% or more, in this order. In “(3×Al ₂ O ₃ +Y ₂ O ₃ +La ₂ O ₃ +Gd ₂ O ₃ +BaO/3+(CaO+SrO)/6)”, “Al ₂ O ₃ ” is Al ₂ O ₃ content, “Y ₂ O ₃ ” is Y ₂ O ₃ content, “La ₂ O ₃ ” is La ₂ O ₃ content, “Gd ₂ O ₃ ” is Gd ₂ O ₃ content, “BaO” is BaO content, and “CaO” is CaO content, "SrO" is the SrO content. That is, “(3×Al ₂ O ₃ +Y ₂ O ₃ +La ₂ O ₃ +Gd ₂ O ₃ +BaO/3+(CaO+SrO)/6)” is a value calculated by multiplying the Al ₂ O ₃ content by three. , the Y ₂ O ₃ content, the La ₂ O ₃ content, the Gd ₂ O ₃ content, the value calculated as 1/3 of the BaO content, and 1/6 of the sum of the CaO content and the SrO content It is the sum of the calculated value and the value calculated in this way, and shall be indicated by attaching % (mol%) as a unit to the value thus calculated.
On the other hand, if the value of “(3×Al ₂ O ₃ +Y ₂ O ₃ +La ₂ O ₃ +Gd ₂ O ₃ +BaO/3+(CaO+SrO)/6)” is too large, the meltability of the glass tends to deteriorate. _, the position of _{near - infrared absorption tends} to _shift to the visible light _side . The value calculated as is preferably 40.0% or less, 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.

of the value calculated by “(3×Al ₂ O ₃ +Y ₂ O ₃ +La ₂ O ₃ +Gd ₂ O ₃ +BaO/3+(CaO+SrO)/6)” with respect to the total content of P ₂ O ₅ , BaO and CuO The ratio, i.e., "( _3xAl2O3 +Y2O3+ _La2O3 + _{Gd2O3 +} BaO/ _{3 + (} CaO+SrO)/ ₆ )/ ₍ P2O5 ₊ BaO+CuO)" is 0.0 or more be able to. _The components selected from the group consisting of _{Al2O3 , Y2O3 ,} La2O3 _{, Gd2O3 ,} BaO, CaO and SrO _are constant relative to the essential components _P2O5 , BaO and CuO. It is desirable to introduce more than the required amount. Therefore, the ratio is preferably 0.05 or more, and more preferably 0.06 or more, 0.07 or more, 0.08 or more, 0.09 or more, 0.10 or more, and 0.11 or more in that order.
On the other hand, if the above ratio is too large, the transmittance characteristics of the glass deteriorate and the stability of the glass tends to deteriorate. 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.

The ZnO content can be 0%, greater than or equal to 0%, 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 compared to other divalent components (especially BaO, SrO, and CaO), it can deteriorate the near-infrared absorption characteristics. be. In addition, from the viewpoint of sufficiently ensuring the introduction amount of P ₂ O ₅ which is an essential component, the upper limit of the content is preferably 10.0% or less, 9.0% or less, 8.0% or less, The order of 7.0% or less, 6.0% or less, and 5.0% or less is more preferable. On the other hand, when ZnO is introduced to adjust the thermal stability of the glass and lower the Tg and/or Tm, the , 1.2% or more, 1.4% or more, 1.6% or more, 1.8% or more, and 2.0% or more, in that order.

It is preferable that the glasses 1 to 6 are basically composed of the above components, but other components may be contained within a range that does not interfere with the effects of the above components. In addition, glass 1 to 6 does not exclude inclusion of unavoidable impurities.

For example, Nb ₂ O ₅ and ZrO ₂ are added as components other than the above components to adjust the weather resistance and mechanical strength of the glass, or to improve the thermal stability. or more or 0.2% or more can be appropriately introduced, but the content of each is desirably 5.0% or less, 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 are preferred in that order. The content of each of these components can also be 0%.

TiO ₂ , WO ₃ , and Bi ₂ O ₃ are also used as components other than the above components to adjust the weather resistance and mechanical strength of the glass, or to improve the thermal stability, to the extent that they do not affect the transmittance of the glass. , respectively, more than 0%, 0.1% or more, or 0.2% or more can be appropriately introduced, but the content of each is preferably 4.0% or less, 3.0% or less, and 2.0%. % or less, 1.0% or less, 0.5% or less, and 0.3% or less, in that order. The content of each of these components can also be 0%.

Pb, As, Cd, Tl, Be and Se are all toxic. Therefore, glasses 1 to 6 preferably do not contain these as glass components.

All of U, Th, and Ra are radioactive elements. Therefore, glasses 1 to 6 preferably do not contain these as glass components.

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 a source of fluorescence. Therefore, in glasses 1 to 6, the total content of these elements based on oxide glass based on oxide glass is preferably 10 ppm by mass or less, and it is more preferable not to include these elements as glass components.

Among them, it is preferable not to use V ₂ O ₅ because it is toxic and deteriorates transmittance characteristics in the visible region. That is, in one embodiment, glasses 1 to 6 are preferably glasses that do not contain V ions, and the content of V ₂ O ₅ is 1.0% or less in the oxide-based glass composition (expressed in mol %). is preferably 0.3% or less, 0.1% or less, and 0.01% or less, in that order, and it is even more preferable that V ₂ O ₅ is not included.

As an example, the ratio of the V ₂ O ₅ content to the Li ₂ O content (V ₂ O ₅ /Li ₂ O) is 0.0080 as the ratio of V ₂ O ₅ to the essential component Li ₂ O. It is preferably 0.0048 or less, 0.0028 or less, 0.0018 or less, and 0.0014 or less, in that order.

CoO lowers the transmittance of the glass in the visible region and is toxic, so it is preferable not to use it. That is, in one form, glasses 1 to 6 are preferably glasses that do not contain Co ions, and preferably do not contain CoO in the oxide-based glass composition.

Raw materials for introducing Ge and Ta into glass are expensive. Therefore, glasses 1 to 6 preferably do not contain these as glass components.

Sb ₍ Sb2O3) _, Sn ₍ SnO2), Ce ₍ CeO2), and SO3 _are optional elements that function as refining agents. Among these, Sb (Sb ₂ O ₃ ) is a refining agent having a large refining effect.
Sn(SnO ₂ ) and Ce(CeO ₂ ) have a smaller refining effect than Sb(Sb ₂ O ₃ ). These refining agents tend to increase the coloration of the glass when added in large amounts. Therefore, when adding a clarifying agent, it is preferable to add Sb (Sb ₂ O ₃ ) while considering the influence of coloration due to the addition.

The content of the component that can function as a fining agent described below is the value in the oxide-based glass composition.

The Sb ₂ O ₃ content is expressed as the outside division. That is, the Sb ₂ O ₃ content is 2.0 mass % when the total content as oxides of all glass components other than Sb ₂ O ₃ , SnO ₂ , CeO ₂ and SO ₃ is 100.0 mass %. %, 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, in that order. The content of Sb ₂ O ₃ may be 0 mass %. However, from the viewpoint of promoting the oxidation of the glass and increasing the transmittance in the visible region, the Sb ₂ O ₃ content can be 0.01% by mass or more, 0.02% by mass or more, 0.03% by mass or more. , 0.04 mass % or more, 0.05 mass % or more, 0.06 mass % or more, or 0.08 mass % or more.

The SnO ₂ content is also expressed as an external division. That is, the content of SnO ₂ is 2.0% by mass when the total content as oxides of all glass components other than SnO ₂ , Sb ₂ O ₃ , CeO ₂ and SO ₃ is 100.0% by mass. 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 0.4% by mass or less, 0.3% by mass or less, 0.2% by mass or less, and 0.1% by mass, in this order, are more preferable. The SnO ₂ content may be 0% by weight. By setting the SnO ₂ content within the above range, the clarity of the glass can be improved.

The CeO ₂ content is also expressed as an outside weight. That is, the CeO ₂ content is less than 2.0% by mass when the total content as oxides of all glass components other than CeO ₂ , Sb ₂ O ₃ , SnO ₂ and SO ₃ is 100.0% by mass. is 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 less than 0.1% by mass, in that order. The CeO ₂ content may be 0% by weight. By setting the CeO ₂ content within the above range, the clarity of the glass can be improved.

The SO3 content is also _expressed as an external division. That is _, the SO3 content is preferably _2.0 mass% when the _total content of all glass components other _than SO3 _, Sb2O3 _, SnO2 and CeO2 as oxides is 100.0 mass%. %, more preferably less than 1.0 mass %, still more preferably less than 0.5 mass %, still more preferably less than 0.1 mass %. The _SO3 content may be 0% by weight. By setting the content of SO ₃ within the above range, the clarity of the glass can be improved.

In one embodiment, glasses 1 to 6 have a ratio of BaO content to Li ₂ O content (BaO/Li ₂ O) of 1.0 or more in the glass composition expressed in mol% based on oxides, and the following One or more of (1) to (4) can be satisfied. The glasses 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 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)) 0.02 or more,
(3) the ratio of the total content of K ₂ O + CaO + SrO to the BaO content ((K ₂ O + 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 more.

<Glass 7>
Next, the glass 7 will be explained.

The glass 7 is a near-infrared absorbing glass having the following glass composition expressed in mol % based on oxides.
P ₂ O ₅ content is 40.0 to 65.0 mol%,
CuO content is 9.0 to 25.0 mol%,
BaO content is 5 to 50 mol%,
the total content of Li ₂ O, Na ₂ O and K ₂ O (Li ₂ O + Na ₂ O + K ₂ O) is 1.0 to 15.0 mol%;
_SiO2 content not more than 2.0 mol%,
B ₂ O ₃ content is 2.0 mol% or less,
Al ₂ O ₃ content is 0.5 to 7.0 mol% or less,
Li ₂ O 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 the 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 %, the ratio of the content of O ions to the content of P ions (O ions/P ions) is 3.50 or less,
The content of F ions is 10.0 anion % or less in the glass composition expressed in anion %.

_In glass ₇ , P2O5 content, CuO content, BaO content, _total content of Li2O _{, Na2O} and _K2O , _SiO2 content, _B2O3 content, _{Al2O 3} content, Li ₂ O content, ZnO content, PbO content, and the ratio of the MgO content to the total content of MgO, CaO, SrO and BaO are within the above ranges. In such a glass 7, from the viewpoint of improving both the transmittance in the visible region and the near-infrared cutting ability, and from the viewpoint of improving the thermal stability of the glass, the content of P ions in the glass composition expressed in atomic % The content ratio of O ions to the (O/P ratio) is 3.50 or less. In the glass 7, the O/P ratio is preferably 3.40 or less, preferably 3.30 or less, and 3.20 or less in that order.
When the glass 7 has a thickness of 0.25 mm or less and an external transmittance of 50% at a wavelength of 620 to 650 nm, 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%. In order to provide the following transmittance characteristics, the O/P ratio is preferably 3.15 or less, more preferably 3.10 or less, and 3.05 or less in that order. On the other hand, from the viewpoint of improving the weather resistance and/or suppressing the deterioration of the meltability, it is preferable that the O/P ratio in the glass 7 is large. From this point, the O/P ratio in the glass 7 is preferably 2.85 or more, 2.86 or more, 2.87 or more, 2.88 or more, 2.89 or more, 2.90 or more, 3 The order of 0.00 or more is more preferable.

The oxide-based glass composition of the glass 7 (expressed in mol %) will be described in more detail below.

The CuO content of the glass 7 is 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% 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, 20.0% or more are preferred in this order. . The CuO content is 25.0% or less, 24.5% or less, 24.0% or less, 23.5% or less, from the viewpoint of leaving room for introduction of glass-forming components and maintaining the thermal stability of the glass. % 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, in that order.

The CuO content is 15.0% or more so that the wavelength λ _T 50 at which the external transmittance including the reflection loss is 50% is in the range of 600 nm to 650 nm as the transmittance characteristic in terms of the thickness of 0.16 mm. 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.
In order for the wavelength λ _T 50 at which the external transmittance including the reflection loss is 50% as a transmittance characteristic in terms of thickness of 0.21 mm to be in the range of 600 nm to 650 nm, the CuO content is 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% Above, 18.5% or more, 19.0% or more, 19.5% or more, and 20.0% or more are preferred in that order.
The CuO content is 10.0% or more so that the wavelength λ _T 50 at which the external transmittance including the reflection loss is 50% is in the range of 600 nm to 650 nm as the transmittance characteristic in terms of the thickness of 0.25 mm. 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.
On the other hand, regarding the transmittance characteristics in terms of thickness of 0.25 mm, if the CuO content is large, the wavelength λ _T 50 at which the external transmittance including reflection loss is 50% may be less than 600 nm. is 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, The order of 21.0% or less, 20.5% or less, and 20.0% or less is more preferable.
The CuO content is 10.0% or more in order for the thickness of the glass to be 0.25 mm or less at which the wavelength λ _T 50 is 645 nm at which the external transmittance including reflection loss is 50% at a wavelength of 550 nm 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% 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 are preferred in that order.
The CuO content is 10.5% or more in order for the thickness of the glass to be 0.25 mm or less at which the wavelength λ _T 50 is 633 nm at which the external transmittance including reflection loss is 50% at a wavelength of 550 nm 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% 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 are preferred in that order.

Glass 7 contains P ₂ O ₅ as an essential component. As described above, it is preferable that the O/P ratio is low from the viewpoint of achieving both an improvement in the transmittance in the visible region and an improvement in the ability to cut near-infrared rays. _In order to reduce the O/P ratio, it is preferable to increase the _P2O5 content. From this point, the P ₂ O ₅ content of the glass 7 is 40.0% or more, 41.0% or more, 42.0% or more, 43.0% or more, 44.0% or more, 45.0% or more. % 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 P ₂ O ₅ itself is a component that does not have near-infrared absorption capability, from the viewpoint of increasing the CuO content that has near-infrared absorption capability, the P ₂ O ₅ content is 65.0% or less, 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 are preferred in this order. In addition, it is preferable that the P ₂ O ₅ content is equal to or less than the above value from the viewpoint of further suppressing deterioration of weather resistance and/or from the viewpoint of suppressing deterioration of meltability.

In one form, the glass 7 tends to shift the half value to the short wavelength side in the oxide-based glass composition from the viewpoint of enhancing the near _- infrared cutting ability of the glass and improving the transmittance in the visible region. It can be a glass containing _one or _both of O3 and _SiO2 , and in another form it can be a glass containing neither _B2O3 nor _SiO2 .
In the glass 7, from the viewpoint of further improving the transmittance in the visible region, the SiO ₂ content is 2.0% or less, preferably 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, when the glass 7 is roughly melted in a quartz crucible in order to promote homogenization of the glass, the SiO ₂ content is preferably greater than 0%, 0.01% or more, and 0.01% or more. 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, in that order. However, the introduction of excess _SiO2 into the glass tends to degrade the optical homogeneity of the glass. From this point, the SiO ₂ content in the glass 7 is preferably 2.0% or less, 1.4% or less, 0.9% or less, 0.8% or less, 0.6% or less, 0 .4% or less is more preferred.
In the glass 7, from the viewpoint of further improving the transmittance in the visible region, the B ₂ O ₃ content is 2.0% or less, 1.5% or less, 1.0% or less, or 0.5% or less. preferred in order. _{The B2O3} content can also be 0%.
On the other hand, when the glass 7 is roughly melted in a quartz crucible in order to promote homogenization of the glass, the B ₂ O ₃ content is preferably more than 0%, 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, in that order. However, the introduction of excess _SiO2 into the glass tends to degrade the optical homogeneity of the glass. From this point, the SiO ₂ content in the glass 7 is preferably 2.0% or less, 1.4% or less, 0.9% or less, 0.8% or less, 0.6% or less, 0 .4% or less is more preferred.

Glass 7 contains Li _{2 O in one form and does not contain Li 2 O} in another form in an oxide-based glass composition. Li ₂ O has a high ability to maintain the absorption of CuO in the long wavelength region and has a small adverse effect on weather resistance as compared with various glass components. From this point of view, the Li ₂ O content can be 0% or more or more than 0%, preferably 0.1% or more, 0.5% or more, 1.0% or more, 1.2% or more. % or more is preferable. On the other hand, from the viewpoint of ensuring the thermal stability of the glass and/or from the viewpoint of further suppressing and maintaining the deterioration of the weather resistance, the Li ₂ O content in the glass 7 is 7.0% or less. 0% or less, 5.0% or less, 4.0% or less, 3.0% or less, and 2.8% or less are preferred in this order. The Li ₂ O content of 7.0% or less is also preferable from the viewpoint of suppressing deliquescence of the glass.

In glass 7, Al ₂ O ₃ is a component that can contribute to particularly enhancing weather resistance. From the viewpoint of improving weather resistance, the Al ₂ O ₃ content is 0.5% or more, 0.6% or more, 0.7% or more, 0.9% or more, 1.1% or more, 1.2% or more. % or more is preferable. On the other hand, from the viewpoint of further suppressing the decrease in transmittance in the visible region and improving the near-infrared transmittance characteristics, the Al ₂ O ₃ content is 7.0% or less, 6.5% or less, and 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, in this order.

In the glass 7, MgO is a component that can be added as appropriate for adjusting the thermal stability of the glass. tend to be difficult to increase. Also, the meltability of the glass tends to decrease as the MgO content increases. From these viewpoints, the MgO content is 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, and 2.0% or less, in that order. The MgO content can also be 0%. In one form, from the viewpoint of improving the mechanical strength of the glass, the MgO content can be more than 0%, preferably 0.5% or more, and more preferably 1.0% or more. .

La ₂ O ₃ is a component that can contribute to enhancing the weather resistance without impairing the near-infrared absorption properties of the glass. The La ₂ O ₃ content is preferably 0.10% or more, more preferably 0.15% or more, 0.18% or more, and 0.21% or more in this order. On the other hand, from the viewpoint of further suppressing the decrease in transmittance in the visible region, the La ₂ O ₃ content is preferably 8.0% or less, 7.0% or less, 6.5% or less. 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% 1.5% or less, 1.0% or less, 0.5% or less, and 0.1% or less, in that order. It can even be 0%. The La ₂ O ₃ content may be 0%.

Y ₂ O ₃ is also a component that can contribute to enhancing the weather resistance without impairing the near-infrared absorption properties of the glass. Y ₂ O ₃ content is preferably 0.10% or more, 0.15% or more, 0.20% or more, 0.25% or more, 0.30% or more, 0.35% or more, 0 0.40% or more, 0.45% or more, and 0.50% or more are preferred in that order. On the other hand, from the viewpoint of further suppressing the decrease in transmittance in the visible region, the Y ₂ O ₃ content is preferably 8.0% or less, 7.0% or less, 6.5% or less. 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% 1.5% or less, 1.0% or less, 0.5% or less, and 0.1% or less, in that order. The Y ₂ O ₃ content may be 0%.
Y ₂ O ₃ can also be introduced from the viewpoint of increasing the molar volume of the glass without increasing the specific gravity of the glass.

Gd ₂ O ₃ is also a component that can contribute to improving weather resistance. The Gd ₂ O ₃ content is preferably 0.10% or more, more preferably 0.15% or more, 0.18% or more, and 0.21% or more in this order. On the other hand, from the viewpoint of further suppressing the decrease in transmittance in the visible region, the Gd ₂ O ₃ content is preferably 8.0% or less, 7.0% or less, 6.5% or less. 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% 1.5% or less, 1.0% or less, 0.5% or less, and 0.1% or less, in that order. The Gd ₂ O ₃ content may be 0%.

The oxide-based glass composition may or may not contain one or more rare earth oxides other than those mentioned above, such as Lu ₂ O ₃ and Sc ₂ O ₃ . Since these components are generally expensive, the content of rare earth oxides other than La ₂ O ₃ , Y ₂ O ₃ and Gd ₂ O ₃ (if two or more are included, their total content) is 2.5 % or less, preferably 1.5% or less, 1.0%, 0.5% or less, or even 0%.

In glass 7, the total content of Al ₂ O ₃ , La ₂ O ₃ , Y ₂ O ₃ and Gd ₂ O ₃ (Al ₂ O ₃ +La ₂ O ₃ +Y ₂ O ₃ +Gd ₂ O ₃ ) improves weather resistance. From the viewpoint of, it is preferably 0.5% or more, 0.55% or more, 0.60% or more, 0.65% or more, 0.70% or more, 0.75% or more, 0.80% Above, 0.85% or more, and more preferably 0.90% or more, in that order. On the other hand, the total content (Al ₂ O ₃ +La ₂ O ₃ +Y ₂ O ₃ +Gd ₂ O ₃ ) is 8.0% or less from the viewpoint of ensuring the thermal stability of the glass and/or lowering the melting temperature. 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; 5% or less, 3.0% or less, 2.5% or less, 2.0% or less, 1.5% or less, and 1.0% or less are preferred in that order.

In the oxide-based glass composition of Glass 7, BaO is an essential component. BaO is a component that can improve weather resistance by introducing a certain amount, and tends to cause less deliquescence than alkali metal oxides. Moreover, BaO can be added for the purpose of improving the thermal stability of the glass and adjusting the meltability. Furthermore, BaO can contribute to lowering T1200, but excessive introduction tends to lower T400. T1200 and T400 will be described later. From the above viewpoint, the BaO content in the glass 7 is preferably 5.0% or more, preferably 10.0% or more, 15.0% or more, 17% or more, 19% or more, and 21% or more, in that order. From the above viewpoint, the BaO content in the glass 7 is 50.0% or less, 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 are preferred in that order.

The SrO content can be 0%, greater than or equal to 0%, or greater than 0%. Like BaO, SrO is a component that is relatively difficult to lower the weather resistance, and is a component that can be added as appropriate for adjusting the thermal stability of the glass. SrO can also be used to adjust the concentration of CuO. SrO content is preferably 0.5% or more, 1.0% or more, 1.5% or more, 2.0% or more, 2.5% or more, 3.0% or more, 3.5% 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 T400 tends to decrease due to excessive introduction, the SrO content is preferably 30.0% or less, 29.0% or less, 28.0% or less, 27.0% or less, 26 .0% or less, 26.0% or less, 25.0% 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, in that order.

The CaO content can be 0%, greater than or equal to 0%, or greater than 0%. CaO is a component that makes it relatively difficult to reduce the weather resistance, and is a component that 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. CaO content is preferably 0.5% or more, 1.0% or more, 1.5% or more, 2.0% or more, 2.5% or more, 3.0% or more, 3.5% 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 this order. However, since T400 tends to decrease due to excessive introduction, the CaO content is preferably 30.0% or less, 29.0% or less, 28.0% or less, 27.0% or less, 26 .0% or less, 26.0% or less, 25.0% 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, in that order.

The Na ₂ O content can be 0%, greater than or equal to 0%, or greater than 0%. Excess introduction of Na ₂ O tends to lower the weather resistance. Therefore, the Na ₂ O content is preferably 5.0% or less, more preferably 4.0% or less, 3.0% or less, 2.0% or less, and 1.0% or less, in that order.

_The K2O content can be 0%, greater than or equal to 0%, or greater than 0%. Among the same alkalis, it has the effect of improving the near-infrared absorption characteristics compared to Li2O Na2O, but K ₂ O also tends to reduce weather resistance when excessively introduced. From these viewpoints, the K ₂ O content is preferably 10.0% or less, 9.0% or less, 8.0% or less, 7.0% or less, 6.0% or less, 5.0% or less. % or less, 4.0% or less, 3.0% or less, 2.0% or less, and 1.0% or less, in that order.

The Cs ₂ O content can be 0%, greater than or equal to 0%, or greater than 0%. Since Cs ₂ O also tends to lower the weather resistance, it is desirable not to actively introduce it. Cs ₂ O content is 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 Cs ₂ O content can be 0.5% or more, 1.0% or more, 1.5% or more, 2.0% or more. , 2.5% or more, 3.0% or more, 3.5% or more, or 4.0% or more.

1. In glass 7, the total content of Li ₂ O, Na ₂ O and K ₂ O (Li ₂ O+Na ₂ O+K ₂ O) is 1.0% or more from the viewpoint of meltability and near-infrared absorption characteristics; It is preferably 0% or more, more preferably 3.0% or more. From the viewpoint of further suppressing deterioration of weather resistance, the total content (Li ₂ O + Na ₂ O + K ₂ O) is 15.0% or less, 14.0% or less, 13.0% or less, 12.0% or less. % 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, and 4% or less, in that order. When the total content (Li ₂ O + Na ₂ O + K ₂ O) is equal to or less than the above value, the coefficient of thermal expansion increases, the amount of expansion and contraction of the glass increases, and the volume change of the glass is regulated by other members. It is also preferable from the viewpoint of avoiding chipping or cracking of the glass due to stress being applied to the glass when it is pressed.

The ZnO content can be 0%, greater than or equal to 0%, 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. is 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 , 2.5% or less. On the other hand, when ZnO is introduced to adjust the thermal stability of the glass and lower the Tg and/or Tm, the ZnO content is 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 are preferred in that order.

In glass 7, from the viewpoint of maintaining near-infrared transmittance absorption characteristics while maintaining weather resistance, the ratio of MgO content to the total content of MgO, CaO, SrO and BaO (MgO/(MgO + CaO + SrO + BaO)) is 0. 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 can be 0.

Although it is preferable that the glass 7 is basically composed of the above components, other components may be contained within a range that does not impair the effects of the above components. Moreover, the glass 7 does not exclude inclusion of unavoidable impurities.
For example, Nb ₂ O ₅ and ZrO ₂ are, as components other than the above components, more than 0% and 0.1%, respectively, for adjusting the weather resistance and mechanical strength of the glass or improving the thermal stability. or more or 0.2% or more can be introduced as appropriate. The content of each is preferably 5.0% or less, 4.0% or less, 3.0% or less, 2.0% or less, 1.0% or less, 0.5% or less, 0.3% or less. more desirable in order. The content of each of these components can also be 0%.

TiO ₂ , WO ₃ , and Bi ₂ O ₃ are also used as components other than the above components to adjust the weather resistance and mechanical strength of the glass, or to improve the thermal stability, to the extent that they do not affect the transmittance of the glass. , respectively, more than 0%, 0.1% or more, or 0.2% or more can be appropriately introduced, but the content of each is preferably 4.0% or less, 3.0% or less, and 2.0%. % or less, 1.0% or less, 0.5% or less, and 0.3% or less, in that order. The content of each of these components can also be 0%.

In Glass 7, the PbO content is 2.0 mol % or less. Since Pb is toxic, the PbO content in the glass 7 is preferably 0%.

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

All of U, Th, and Ra are radioactive elements. Therefore, it is preferable that the glass 7 does not contain these as glass components.

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 a source of fluorescence. Therefore, the glass 7 preferably contains 10 mass ppm or less of these elements in total, based on oxide glass, and more preferably does not contain these elements as glass components.
Among them, it is preferable not to use V ₂ O ₅ because it is toxic and deteriorates the transmittance characteristics in the visible region. That is, in one form, the glass 7 is preferably glass that does not contain V ₂ O ₅ , and the content of V ₂ O ₅ is 1.0% or less in the oxide-based glass composition (expressed in mol %). is preferably 0.3% or less, 0.1% or less, and 0.01% or less, in that order, and it is even more preferable that V ₂ O ₅ is not included.
CoO lowers the transmittance of the glass in the visible region and is toxic, so it is preferable not to use it. That is, in one form, the glass 7 is preferably glass that does not contain CoO.
Raw materials for introducing Ge and Ta into glass are expensive. Therefore, the glass 7 preferably does not contain these as glass components.

Sb ₍ Sb2O3) _, Sn ₍ SnO2), Ce ₍ CeO2), and SO3 _are optional elements that function as refining agents. Among these, Sb (Sb ₂ O ₃ ) is a refining agent having a large refining effect.
Sn(SnO ₂ ) and Ce(CeO ₂ ) have a smaller refining effect than Sb(Sb ₂ O ₃ ). These refining agents tend to increase the coloration of the glass when added in large amounts. Therefore, when adding a clarifying agent, it is preferable to add Sb (Sb ₂ O ₃ ) while considering the influence of coloration due to addition.
The content of the component that can function as a fining agent described below is the value in the oxide-based glass composition.
The Sb ₂ O ₃ content is expressed as the outside division. That is, the Sb ₂ O ₃ content is 2.0 mass % when the total content as oxides of all glass components other than Sb ₂ O ₃ , SnO ₂ , CeO ₂ and SO ₃ is 100.0 mass %. %, 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, in that order. The content of Sb ₂ O ₃ may be 0 mass %. However, from the viewpoint of promoting the oxidation of the glass and increasing the transmittance in the visible region, the Sb ₂ O ₃ content can be 0.01% by mass or more, 0.02% by mass or more, 0.03% by mass or more. , 0.04 mass % or more, 0.05 mass % or more, 0.06 mass % or more, or 0.08 mass % or more.
The SnO ₂ content is also expressed as an outside weight. That is, the content of SnO ₂ is 2.0% by mass when the total content as oxides of all glass components other than SnO ₂ , Sb ₂ O ₃ , CeO ₂ and SO ₃ is 100.0% by mass. 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 0.4% by mass or less, 0.3% by mass or less, 0.2% by mass or less, and 0.1% by mass, in this order, are more preferable. The SnO ₂ content may be 0% by weight. By setting the SnO ₂ content within the above range, the clarity of the glass can be improved.
The CeO ₂ content is also expressed as an outside weight. That is, the CeO ₂ content is less than 2.0% by mass when the total content as oxides of all glass components other than CeO ₂ , Sb ₂ O ₃ , SnO ₂ and SO ₃ is 100.0% by mass. is 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 less than 0.1% by mass, in that order. The CeO2 content may be ₀ % by weight. By setting the CeO ₂ content within the above range, the clarity of the glass can be improved.
The SO3 content is also _expressed as an external division. That is _, the SO3 content is preferably _2.0 mass% when the _total content of all glass components other _than SO3 _, Sb2O3 _, SnO2 and CeO2 as oxides is 100.0 mass%. %, more preferably less than 1.0 mass %, still more preferably less than 0.5 mass %, still more preferably less than 0.1 mass %. The _SO3 content may be 0% by weight. By setting the content of SO ₃ within the above range, the clarity of the glass can be improved.

In one form, the glass 7 can satisfy one or more of the following (1) to (4). The glass 7 may 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 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)) 0.02 or more,
(3) the ratio of the total content of K ₂ O + CaO + SrO to the BaO content ((K ₂ O + CaO + SrO)/BaO) is 0.12 or more;
(4) The ratio of the total content of K ₂ O, CaO, SrO and ZnO to the total content of MgO and BaO ((K ₂ O+CaO+SrO+ZnO)/(MgO+BaO)) is 0.12 or more.

In the glass composition expressed in anion %, the glass 7 can contain at least O ions as anions, and the content thereof can be 90.0 anion % or more. By lowering the O/P ratio in a glass mainly composed of O ions as anions in this way, the absorption of CuO in the red region can be shifted to the longer wavelength side, thereby reducing the transmittance in the red region. The present inventor believes that it is possible to improve the near-infrared cut ability by increasing the content of CuO without adding any. In the glass 7, the O ion content in the glass composition expressed as anion % is preferably 95.0% or more, more preferably 98.0% or more, and further preferably 99.0% or more. preferable. A high proportion of O ions in the anion component is also preferable for suppressing volatilization during melting of the glass. Suppressing the volatilization during melting of the glass is preferable from the viewpoint of suppressing the generation of striae. In particular, the content of O ions is preferably 100% from the viewpoint of suppressing volatilization during glass melting, enhancing productivity, and suppressing the generation of harmful gases during production.

In the glass composition expressed by anion %, the glass 7 can contain only O ions as anions in one mode, or can contain one or more other anions together with O ions in another mode. Other anions include F ions, Cl ions, Br ions, I ions, and the like.

In the glass composition expressed by anion % of the glass 7, the content of F ions is 10.0 anion % or less, preferably 5.0 anion % or less, from the viewpoint of improving the uniformity and strength of the glass. , more preferably 2.0 anion % or less, and even more preferably 1.0 anion % or less. In particular, the glass 7 may be a glass that does not contain F ions, from the viewpoint of suppressing volatilization during melting of the glass, enhancing productivity, and suppressing generation of harmful gas during production.

<Glass 8>
Next, the glass 8 will be explained.

The glass 8 has a thickness of 0.25 mm or less, and has an external transmittance of 75% or more at a wavelength of 400 nm and an external transmittance of 7% at a wavelength of 1200 nm when converted to a thickness at which the external transmittance is 50% at a wavelength of 620 to 650 nm. Near-infrared rays having the following transmittance characteristics and an average linear expansion coefficient at 100 to 300° C. (hereinafter also referred to as “α (100 to 300° C.)”) of 135×10 ⁻⁷ /K or less Absorbing glass.
In other words, the transmittance characteristics are such that the external transmittance at a wavelength of 400 nm is 75% or more in terms of the thickness at which the external transmittance is 50% at a wavelength of 620 to 650 nm. When the thickness at which the external transmittance at a wavelength of 1200 nm is 7% or less in terms of the thickness at which the transmittance is 50% is called T1, one or two or more T1 exist within the range of 0.25 mm or less. That's what it means.

In one embodiment, the glass 8 has a thickness of 0.23 mm or less, and has an external transmittance of 80% or more at a wavelength of 400 nm and an external transmittance of 80% or more at a wavelength of 1200 nm when converted to a thickness at which the external transmittance is 50% at a wavelength of 625 to 650 nm. It can be a near-infrared absorbing glass having a transmittance characteristic of 5% or less and an average linear expansion coefficient of 130×10 ⁻⁷ /K or less at 100 to 300° C.
In other words, the transmittance characteristics are such that the external transmittance at a wavelength of 400 nm is 80% or more in terms of the thickness at which the external transmittance is 50% at a wavelength of 620 to 650 nm, and the external transmittance at a wavelength of 620 to 650 nm is 80% or more. When the thickness at which the external transmittance at a wavelength of 1200 nm is 5% or less in terms of the thickness at which the transmittance is 50% is called T2, one or two or more T2 exist within the range of 0.23 mm or less. That's what it means.

In recent years, compact cameras such as cameras mounted on smartphones not only digitize obtained image information, but also reconstruct images by performing various computational processes on the image information. For example, it has become mainstream to extract a specific object and adjust the color and contrast of the image. At that time, if non-existent color information is input to the imaging device due to the reflection of light in the optical element, that information must be removed, which is undesirable. In order to do so, the near-infrared absorbing glass is desired to have a thickness of 0.25 mm or less (furthermore, a thickness of 0.23 mm) or less. A near-infrared absorbing glass having such a thickness and having the above-mentioned transmittance characteristics is preferable from the viewpoint of achieving both the above-mentioned high performance and miniaturization.

On the other hand, if the α (100 to 300°C) of the glass is large, after polishing the glass to a thickness of 0.25 mm or less (or 0.23 mm or less), an antireflection film is formed by vapor deposition or the like to reduce reflection loss. In the steps of heating before film formation and cooling after film formation, the glass is likely to break due to thermal shock. On the other hand, slowing down the rate of temperature rise and temperature of the glass in each step in order to prevent cracking of the glass due to thermal shock leads to a decrease in productivity. On the other hand, the glass 8 with α (100 to 300° C.) of 135×10 ⁻⁷ /K or less (preferably 130×10 ⁻⁷ /K) maintains the productivity and reduces the thermal shock of the glass. It is preferable from the viewpoint of being able to prevent cracking.

Regarding the glass 8, the transmittance characteristic is obtained by a method for measuring the transmittance characteristic, which will be described later.

The α (100-300° C.) of the glass shall be measured by a thermomechanical analyzer. For example, α (100 to 300 ° C.) of glass is obtained by preparing a cylindrical glass sample with a diameter of 5 mm and a length of 20 mm, and using a thermomechanical analyzer "TMA4000s" manufactured by BRUKER axs. can be measured. Note that the temperature rise rate of the sample during measurement can be set to 4° C./min.

For the glass composition of glass 8, only one of the various items described above for glasses 1-7 can be applied, or two or more of the various items described above for glasses 1-7 can be optionally combined. It can also be applied in combination. One or more of the items described above for one of the glasses 1 to 7, optionally in combination with one or more of the items described above for the other glasses, apply to the glass composition of glass 8. be able to. As an example, one or more of the various items described above for the glass 1 and one or more of the various items described above for the glass 2 can be combined and applied to the glass composition of the glass 8. Further, as another example, one or more of the various items described above for the glass 1, one or more of the various items described above for the glass 2, and one or more of the various items described above for the glass 3. and can be applied to the glass composition of the glass 8 in combination. Also, the invention is not limited to these examples, and arbitrary combinations are possible.

<Glass properties>
Next, glass physical properties that the glasses 1 to 8 may have will be described.

(Transmittance characteristics)
Glasses 1 to 8 are suitable as glasses for near-infrared cut filters. In the present invention and in this specification, unless otherwise specified, "transmittance" refers to external transmittance including reflection loss.
As for the near-infrared cut ability, the half value λ _T 50, which is the wavelength at which the transmittance is 50% at a wavelength of 550 nm or longer, can be used as an index, and the transmittance T1200 at a wavelength of 1200 nm can also be used as an index.
Glasses 1-8 can also exhibit high transmittance in the visible range. As for the transmittance in the visible region, the transmittance T400 at a wavelength of 400 nm can be used as an index, and the transmittance T600 at a wavelength of 600 nm can also be used as an index.

The transmittance characteristic of glass is a value obtained by the following method.
A glass sample is processed to have parallel and optically polished flat surfaces, and the external transmittance is measured at wavelengths from 200 to 1200 nm. External transmittance also includes reflection loss of light rays at the sample surface.
The spectral transmittance B/A including the reflection loss is calculated by setting the intensity of a ray perpendicularly incident on one optically polished plane as an intensity A and the intensity of a ray emitted from the other plane as an intensity B. A half value λ _T 50 is a wavelength at which the spectral transmittance is 50% at a wavelength of 550 nm or longer. Let the spectral transmittance at a wavelength of 400 nm be T400, the spectral transmittance at a wavelength of 600 nm be T600, and the spectral transmittance at a wavelength of 1200 nm be T1200.
In addition, if the glass to be measured is not a glass with a thickness that can be converted, the transmittance at each wavelength λ is converted by the following formula A, with the thickness of the glass being d. Various conversion values can be obtained from the rate characteristics.

Formula A: T(λ)=(1−R(λ)) ² ×exp(log _e ((T ₀ (λ)/100)/(1−R(λ)) ² )×d/d ₀ )× 100

In formula A, T (λ): converted transmittance (%) at wavelength λ, T ₀ (λ): measured transmittance (%) at wavelength λ, d: converted thickness (mm), d ₀ : glass Thickness (mm), R(λ)=((n(λ)−1)/(n(λ)+1)) Reflectance at wavelength λ, ⁿ (λ): Refractive index at wavelength λ is. Here, the calculation is performed assuming that n(λ)=1.51680 and R(λ)=0.042165.

The high value of T600, which is the transmittance in the red region, and the low value of T1200, which is the transmittance in the near-infrared region, indicates that both the improvement in the transmittance in the visible region and the improvement in the ability to cut near-infrared rays are achieved. can mean In addition, the high value of T400, which is the transmittance in the violet region, may also mean that the transmittance in the visible region is improved.
From the above viewpoints, the preferred ranges for T400, T600 and T1200 are as follows.
T400 is preferably 70% or more, further 71% or more, 72% or more, 73% or more, 74% or more, 75% or more, 76% or more, 77% or more, 78% or more, 79% 80% or more is more preferable in that order. The T400 can be, for example, 98% or less, 97% or less, or 96% or less, but it can be said that a higher T400 means better visible light transmission, so the values exemplified above are exceeded. is also preferred.
T600 is preferably 50% or more, further 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, 75% or more more preferred. T600 can be, for example, 90% or less, 85% or less, or 80% or less, but it can be said that a higher T600 means better visible light transmission, so the values exemplified above are exceeded. is also preferred.
T1200 is preferably 30% or less, 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 % 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, in that order. T1200 can be, for example, 1% or more, 3% or more, 5% or more, or 7% or more for the purpose of compatibility with visible light transmittance, but a lower T1200 means better near-infrared cut ability. Therefore, it is also preferable to be less than the values exemplified above.

In one form, T1200 can be β1% or less.

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

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

The half value λ _T 50, which is the wavelength at which the spectral transmittance becomes 50% at a wavelength of 550 nm or more, is preferably 600 nm or more, and is 610 nm or more, 613 nm or more, 615 nm or more, 617 nm or more, 620 nm or more, 623 nm or more, 625 nm or more, and 628 nm or more. order is more preferred. The half value λ _T 50 is preferably 650 nm or less, more preferably 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, in that order. Achieving the half-value λ _T 50, which is the wavelength at which the spectral transmittance becomes 50% at a wavelength of 550 nm or longer, with a glass thickness of a predetermined value or less is preferable from the viewpoint of achieving both thinning of the glass and improvement of near-infrared cutting ability. The predetermined glass thickness or less is preferably 0.25 mm or less.

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

Regarding the glasses 1 to 8, the following (a) to (h) can be mentioned as preferred transmittance characteristics of the near-infrared cut filter glass having a thickness of 0.25 mm or less. Glasses 1 to 8 preferably satisfy one or more of the following (a) to (h), and may satisfy two or more. By adjusting the glass composition as described above, a glass having favorable transmittance characteristics can be obtained.

(a) the thickness of the glass is 0.25 mm or less, and the wavelength λ _T 50 at which the external transmittance including reflection loss is 50% at a wavelength of 550 nm or more 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 30% or less.

Regarding the above (a), the thickness of the glass at which the wavelength λ _T 50 is 633 nm at which the external transmittance including reflection loss is 50% at a wavelength of 550 nm or more is 0.25 mm or less, and the thickness of the near-infrared cut filter will be described later. It is more preferable that the thickness range is This point also applies to the following (b), (e) and (f).

(b) the glass has a thickness of 0.25 mm or less and a wavelength of 633 nm at which the external transmittance including reflection loss is 50% at a wavelength of 550 nm or more;
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. β is a value calculated from the following formula B1. In formula B1, R is the O/P ratio of glasses 1-8.

(Formula B1)
β1=64×R-170

As noted above, T1200 can also be the above β2% or less, β3% or less, β4% or less, β5% or less or β6% or less.

(c) As a transmittance characteristic in terms of thickness of 0.16 mm, the wavelength λ _T 50 at which the external transmittance including reflection loss is 50% is in the range of 600 nm to 650 nm, and 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.

(d) As a transmittance characteristic in terms of thickness of 0.21 mm, the wavelength λ _T 50 at which the external transmittance including reflection loss is 50% is in the range of 600 nm to 650 nm, and 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.

(e) the glass has a thickness of 0.25 mm or less and a wavelength of 645 nm at which the external transmittance including reflection loss is 50% at a wavelength of 550 nm or more;
With 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.

(f) the glass has a thickness of 0.25 mm or less and a wavelength λ _T 50 of 645 nm at which the external transmittance including reflection loss is 50% at a wavelength of 550 nm or more;
In 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, and β1 is obtained from the above-described formula 4. It is a calculated value.

(g) As a transmittance characteristic in terms of thickness of 0.23 mm, the wavelength λ _T 50 at which the external transmittance including reflection loss is 50% is in the range of 600 nm to 650 nm, and the external transmittance T1200 including reflection loss at a wavelength of 1200 nm. is 18% or less, and the external transmittance T400 including reflection loss at a wavelength of 400 nm is 70% or more.

(h) As a transmittance characteristic in terms of thickness of 0.25 mm, the wavelength λ _T 50 at which the external transmittance including reflection loss is 50% is in the range of 600 nm to 650 nm, and the external transmittance including reflection loss at a wavelength of 1200 nm is T1200. is 16% or less, and the external transmittance T400 including reflection loss at a wavelength of 400 nm is 70% or more.

(Weatherability)
Glasses 1 to 8 can exhibit excellent weather resistance by having the composition described above. A haze value measured by a haze meter can also be used as an index for weather resistance. Glass with excellent weather resistance is glass having a haze value of 15% or less as measured by a haze meter specified in JIS K 7136:2000 after being stored for 90 minutes under constant temperature and humidity at a temperature of 85 ° C. and a relative humidity of 85%. can be mentioned. The 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.
As for weather resistance, in one aspect, it can be said that the glass that is less susceptible to deliquescence has the better weather resistance. An example of the deliquescent evaluation method includes the method described in Examples below.

(Glass transition temperature Tg, temperature Tm at which the endothermic reaction due to melting converges)
The glass transition temperature of glasses 1 to 8 is not particularly limited, but from the viewpoint of increasing the transmittance of the glass in the short wavelength region by improving the meltability of the glass, and from the viewpoint of reducing the burden on the annealing furnace and the molding apparatus. . From the viewpoint of enhancing the chemical durability and/or heat resistance of the glass, the Tg is preferably 250°C or higher, further 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. more preferred.

The Tg value of the glass is determined by adjusting the content of Li ₂ O, Na ₂ O, K ₂ O, the total content thereof, the content of ZnO, the MgO content, the Al ₂ O ₃ content, the total content thereof, etc. You can control it.

The temperature Tm at which the endothermic reaction due to melting of the glasses 1 to 8 converges is not particularly limited, but the lower the Tm, the better the meltability, and the glass does not devitrify even when molding with a higher viscosity. Tend. Further, there is a tendency that the better the meltability, the higher the transmittance of the glass in the visible region of the short wavelength region. From these viewpoints, Tm is preferably 890° C. or less, and further, 880° C. or less, 870° C. or less, 860° C. or less, 850° C. or less, 840° C. or less, 830° C. or less, 820° C. or less, 810° C. ℃ or less, 800°C or less, 790°C or less, 780°C or less, 770°C or less, 760°C or less, 750°C or less, 740°C or less, 730°C or less, 720°C or less, 710°C or less, 700°C or less, 690°C or less , 680° C. or lower, 670° C. or lower, 660° C. or lower, and 650° C. or lower in this order. The lower limit of Tm is not particularly limited. It can also be 640° C. or higher.

The Tm value of the glass depends on the content of Li ₂ O, Na ₂ O, K ₂ O, the total content thereof, the ZnO content, the MgO content, the Al ₂ O ₃ content, and the total content thereof. You can control it.

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

(specific gravity)
It is preferable that the near-infrared cut filter is lightweight because it leads to weight reduction of an element or device in which this filter is incorporated. From this point, the specific gravity of glasses 1 to 8 is preferably 3.80 or less, 3.40 or less, 3.35 or less, 3.30 or less, 3.25 or less, 3.20 or less, 3.15 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 Then, the order of 2.60 or less is more preferable.
The specific gravity can be, for example, 2.00 or more or 2.40 or more, but since a low specific gravity is preferable from the above viewpoint, it is also preferable to be less than the values exemplified here. The unit of specific gravity is "g/cc".

(molar volume)
Although the molar volume M/D of the glass is not particularly limited, the molar volume of the glass is preferably smaller from the viewpoint of increasing the near-infrared absorbing ability by increasing the amount of CuO per unit volume. _The molar _volume can be reduced by substituting Li2O for _P2O5 , _La2O3 , _Y2O3 , _Gd2O3 , BaO _{, K2O} , etc. _{Al2O3 , CuO ,} Replacing Na ₂ O with Li ₂ O can make it slightly smaller. On the other hand, even if CaO, ZnO, and SrO are replaced with Li ₂ O, the molar volume does not change significantly, and replacing MgO with Li ₂ O tends to increase the molar volume. By adjusting the glass composition in consideration of these tendencies, the molar volume of the glass can be adjusted. The molar volume is preferably 45 cc/mol or less, 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 are preferred in that order.
On the other hand, from the viewpoint of maintaining the weather resistance of the glass, the molar volume can be increased. From this point, the molar volume of glasses 1 to 6 can be 34.0 cc/mol or more, and 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 It can also be 39.5 cc/mol or more.

<Glass manufacturing method>
The above glass can be obtained by preparing, melting, and molding various glass raw materials. Regarding the production method, the description given below can also be referred to.

The near-infrared absorbing glass is suitable as a near-infrared cut filter glass. In addition, the near-infrared absorbing glass can be applied to optical elements (such as lenses) other than the near-infrared cut filter, and can be applied to various other glass products, and various modifications are possible. It is possible.

[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 near-infrared absorbing glass.

The glass constituting the filter is as described above.

A specific example of the method for manufacturing the filter will be described below. However, the following manufacturing method is an example and does not limit the present invention.

The molten glass is appropriately used with glass raw materials such as phosphates, oxides, carbonates, nitrates, sulfates, fluorides, etc., and the raw materials are weighed so as to have a desired composition, mixed, and then placed in a platinum crucible or the like. Melt at, for example, 800° C. to 1100° C. in a melting vessel. At that time, a lid made of platinum or the like may be used to suppress volatilization of volatile components. Also, the melting can be carried out in the atmosphere, and in order to suppress the change in the valence of Cu, an oxygen atmosphere can be used, or oxygen can be bubbled into the molten glass. The glass in the molten state is a homogenized glass melt with reduced bubbles (preferably free of bubbles) by agitation and fining. It is also possible to obtain a glass after fining the glass at 900° C. to 1100° C. and then cooling the glass to 800° C. to 1000° C. in order to accelerate the oxidation of the glass. However, it is not desirable for the melting temperature or fining temperature to be lower than the liquidus temperature of the glass for a long period of time.

After stirring and refining the glass in a molten state, the glass is poured out, slowly cooled, and formed into a desired shape. When pouring out the glass, it is preferable to lower the temperature to a temperature near the liquidus temperature to increase the viscosity of the glass, since convection of the poured glass is less likely to occur and striae are less likely to occur. As the slow cooling rate, a rate between -50°C/hr and -1°C/hr can be selected, and -30°C/hr and -10°C/hr can also be selected.

As a method for forming the glass, known methods such as casting, pipe flow, roll and press can be used. The molded glass is transferred to an annealing furnace preheated to near the glass transition point and slowly cooled to room temperature. Thus, a near-infrared cut filter can be manufactured.

An example of the molding method will be described below. A mold is prepared which is composed of a flat and horizontal bottom surface, a pair of side walls opposing each other in parallel across the bottom surface, and a barrier plate closing one of the openings positioned between the pair of side walls. A homogenized molten glass is cast into this mold from a platinum alloy pipe at a constant outflow speed. The molten glass that has been cast spreads in the mold and is formed into a glass plate that is regulated to a constant width by a pair of side walls. The molded glass sheet is continuously pulled out from the opening of the mold. By appropriately setting molding conditions such as the shape and size of the mold and the outflow speed of the molten glass, a large and thick glass block can be molded. The formed glass molded body is transferred to an annealing furnace preheated to near the glass transition temperature and slowly cooled to room temperature. The glass molded body from which strain has been removed by slow cooling is subjected to machining such as slicing, grinding, and polishing. Thus, it is possible to obtain a near-infrared cut filter having a plate-like shape, a lens-like shape, or the like according to the application. Alternatively, a method of molding a preform made of the above glass, heating and softening the preform, and press molding (especially precision press molding of the final product without mechanical processing such as grinding and polishing on the optical function surface) molding method) and the like can also be used. An optical multilayer film may be formed on the surface of the filter as required.

The near-infrared cut filter can have both excellent near-infrared cut ability and high transmittance in the visible range. With such a near-infrared cut filter, it is possible to satisfactorily correct the color sensitivity of the semiconductor imaging device.

Moreover, the 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 imaging element such as a CCD or a CMOS mounted in a package, and a light-receiving part covered with a translucent member. The near-infrared cut filter can also serve as the translucent member, or the translucent member can be separate from the near-infrared cut filter.

The imaging device can also include an optical element such as a lens or a prism for forming an image of a subject on the light receiving surface of the semiconductor image sensor.

Further, according to the near-infrared cut filter, it is possible to provide an image pickup apparatus capable of obtaining an image of excellent image quality with good color sensitivity correction.

In one form, the near-infrared cut filter can be a near-infrared cut filter having a thickness of 0.25 mm or less. In recent years, with the advent of smartphones, there has been a marked decrease in the thickness of image sensors, and along with this trend, near-infrared cut filters are desired to exhibit their performance with a thinner thickness. As such a near-infrared cut filter, the above near-infrared cut filter is suitable. The thickness of the near-infrared cut filter is 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 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 near-infrared cut filter can be, for example, 0.21 mm or 0.11 mm. Moreover, the thickness of the 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, the term "thickness" refers to the thickness of the sample in the region where the transmittance is measured, and can be measured with 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 a plurality of points within the spot of the transmitted light and the average value thereof may be taken.

Regarding the transmittance characteristics of the near-infrared cut filter, the above description regarding glasses 1 to 8 can be referred to. In addition, regarding the physical properties of the near-infrared cut filter, the above descriptions of glasses 1 to 8 can be referred to.

EXAMPLES The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to the embodiment.

[Examples 1 to 39, Comparative Examples 1 to 3]
As glass raw materials, phosphates, fluorides, carbonates, nitrates, oxides, etc. are weighed and mixed so as to obtain 150 g to 300 g of glass having the composition shown in Table 1, and placed in a platinum crucible or a quartz crucible. The mixture was charged, melted at 800° C. to 1000° C. for 80 to 100 minutes, stirred to degas and homogenized, poured into a preheated mold, and molded into a predetermined shape. The obtained glass molded body was transferred to an annealing furnace heated to around the glass transition temperature and slowly cooled to room temperature. A test piece was cut out from the obtained glass, both sides were mirror-polished to a thickness of about 0.2 mm, and various evaluations were performed by the following methods.
Comparative Example 1 is a glass having the composition of Example 5 of JP-A-2019-38719 (Patent Document 1).
Comparative Example 2 is a glass having the composition of Example 5 of CN110255897.
Comparative Example 3 is a glass having the composition of Example 10 of JP-A-55-3336 (Patent Document 3).

[Evaluation method]
<Transmittance characteristics>
The transmittance of each test piece at wavelengths from 200 to 1200 nm was measured using a spectrophotometer. From the measurement results, half value (unit: nm), T400, T600, T1200 (unit: %) was obtained.
In addition, from the measurement results obtained by measuring the transmittance of each test piece at a wavelength of 200 to 1200 nm using a spectrophotometer, the following transmittance characteristics:
External transmittance at a wavelength of 400 nm and external transmittance at a wavelength of 1200 nm in terms of a thickness of 0.25 mm or less and an external transmittance of 50% at a wavelength of 620 to 650 nm;
The external transmittance at a wavelength of 400 nm and the external transmittance at a wavelength of 1200 nm in terms of a thickness of 0.23 mm or less and an external transmittance of 50% at a wavelength of 625 to 650 nm,
asked for

<Specific gravity>
The specific gravity was measured by the Archimedes method.

<α (100 to 300°C)>
A cylindrical glass sample with a diameter of 5 mm and a length of 20 mm was prepared, and α (100 to 300° C.) was measured using a thermomechanical analyzer "TMA4000s" manufactured by BRUKER axs. The heating rate of the sample during the measurement was set to 4° C./min.

<molar volume>
From the measured specific gravity values, the molar volume was calculated by the method described above.

<Weather resistance evaluation>
Each test piece was held for 90 minutes in a constant temperature and humidity chamber at a temperature of 85° C. and a relative humidity of 85%. After that, using a haze meter specified in JIS K 7136:2000, the cloudiness of the test piece was quantitatively evaluated as a haze value.
The deliquescence was evaluated by observing the state of the polished surface and side roughened surface of each test piece after holding for 90 minutes in a constant temperature and humidity chamber at a temperature of 85° C. and a relative humidity of 85% according to the following evaluation criteria.
○: None of the "stickiness of the polished surface", "transmittance change", and "change in color (darkening) due to water content on the side rough-polished surface" was observed ×: "stickiness of the polished surface", "transmittance change" and "color change (darkening) due to water content on the side rough-printed surface" was confirmed.

The above results are shown in the table below.

From the results shown in the table above, each glass of the above examples has high transmittance in the visible region (purple region to red region) even when thinned, has excellent near-infrared cutting ability, and suppresses deterioration of weather resistance. It can be confirmed that
Comparative Example 1 has a Cu concentration of less than α ₁ % and less than α ₂ %. The glass of Comparative Example 1 cannot be thinned to obtain desired transmittance characteristics.
The glass of Comparative Example 2 had a high T1200 at the reduced thickness.
Since the glass of Comparative Example 3 has a large α (100 to 300° C.), it is fragile as described above.
Further, the glasses of Comparative Examples 1 to 3 had a total content of Li ₂ O, Na ₂ O and K ₂ O (Li ₂ O+Na ₂ O+K ₂ O) of more than 15 mol %, so that the glass easily deliquesced.

Each glass of the above examples was processed into flat plates having three thicknesses, that is, 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. Thus, a near-infrared cut filter having excellent near-infrared cut ability and excellent weather resistance was obtained. A coat such as an antireflection film may be formed on the surface of the near-infrared cut filter.

[Examples 1-1 to 1-4]
The Sb ₂ O ₃ content of the outer division display is 0.1% by mass (Example 1-1), 0.5% by mass (Example 1-2), 1.0% by mass (Example 1-3) or Phosphate, fluoride and carbonate were used as glass raw materials so as to obtain 150 g to 300 g of a glass having the same composition as in Example 1 shown above except that it was 1.5% by mass (Example 1-4). Salts, nitrates, oxides, etc. were weighed and mixed, put into a platinum crucible or a quartz crucible, melted at 800° C. to 1000° C. for 80 to 100 minutes, and stirred to degas and homogenize. After that, it was poured into a preheated mold and molded into a predetermined shape. The obtained glass molded body was transferred to an annealing furnace heated to around the glass transition temperature and slowly cooled to room temperature. A test piece is cut out from the obtained glass, and both sides are mirror-polished to a thickness of about 0.20 mm to about 0.21 mm. T400 (unit: %) was obtained as an external transmittance at a wavelength of 400 nm with a plate thickness at which the external transmittance at 633 nm is 50%. Such T400 was also determined for the glass of Example 1 (no Sb ₂ O ₃ added).
Appearance photographs of the glasses of Examples 1-1 to 1-4 are shown in FIG. FIG. 3 shows a graph plotting the T400 value against the amount of Sb ₂ O ₃ for the glasses of Example 1 and Examples 1-1 to 1-4.

[Examples 4-1 to 4-4]
The Sb ₂ O ₃ content of the outer division display is 0.1% by mass (Example 4-1), 0.5% by mass (Example 4-2), 1.0% by mass (Example 4-3) or Phosphate, fluoride and carbonate were used as glass raw materials so as to obtain 150 g to 300 g of a glass having the same composition as in Example 4 described above except that it was 1.5% by mass (Example 4-4). Salts, nitrates, oxides, etc. were weighed and mixed, put into a platinum crucible or a quartz crucible, melted at 800° C. to 1000° C. for 80 to 100 minutes, and stirred to degas and homogenize. After that, it was poured into a preheated mold and molded into a predetermined shape. The obtained glass molded body was transferred to an annealing furnace heated to around the glass transition temperature and slowly cooled to room temperature. A test piece is cut out from the obtained glass, both sides are mirror-polished to a thickness of about 0.20 mm, and then the transmittance characteristics of each test piece are measured by the method described above. T400 (unit: %) was obtained as an external transmittance at a wavelength of 400 nm at a thickness of 50%. Such T400 was also determined for the glass of Example 4 (without Sb ₂ O ₃ addition).
Appearance photographs of the glasses of Examples 4-1 to 4-4 are shown in FIG. FIG. 5 shows a graph plotting the T400 value against the amount of Sb ₂ O ₃ for the glasses of Example 4 and Examples 4-4 to 4-4.

[Examples 25-1 to 25-4]
The Sb ₂ O ₃ content of the outer division display is 0.1% by mass (Example 25-1), 0.5% by mass (Example 25-2), 1.0% by mass (Example 25-3) or Phosphate, fluoride and carbonate were used as glass raw materials so as to obtain 150 g to 300 g of a glass having the same composition as in Example 25 shown above except that it was 1.5% by mass (Example 25-4). Salts, nitrates, oxides, etc. were weighed and mixed, put into a platinum crucible or a quartz crucible, melted at 800° C. to 1000° C. for 80 to 100 minutes, and stirred to degas and homogenize. After that, it was poured into a preheated mold and molded into a predetermined shape. The obtained glass molded body was transferred to an annealing furnace heated to around the glass transition temperature and slowly cooled to room temperature. A test piece is cut out from the obtained glass, and both sides are mirror-polished to a thickness of about 0.21 mm to about 0.22 mm. T400 (unit: %) was obtained as an external transmittance at a wavelength of 400 nm with a plate thickness at which the external transmittance at 633 nm is 50%. Such T400 was also determined for the glass of Example 25 (without Sb ₂ O ₃ addition).
Appearance photographs of the glasses of Examples 25-1 to 25-4 are shown in FIG. FIG. 7 shows a graph plotting the T400 value against the amount of Sb ₂ O ₃ for the glasses of Example 25 and Examples 25-1 to 25-4.

From the results shown in FIGS. 2 to 7, it can be confirmed that addition of Sb ₂ O ₃ to the glass is preferable from the viewpoint of promoting the oxidation of the glass and increasing the transmittance in the visible region. In one form, the Sb ₂ O ₃ content of the outer percentage display 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.

Finally, each aspect described above is summarized.

According to one aspect, glasses 1-6 as detailed above are provided.

In one embodiment, glasses 1 to 6 have a ratio of BaO content to Li ₂ O content (BaO/Li ₂ O) of 1.0 or more in the glass composition expressed in mol% based on oxides, and the following It can be a glass that satisfies one or more of (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)) 0.02 or more,
(3) the ratio of the total content of K ₂ O + CaO + SrO to the BaO content ((K ₂ O + 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 more.

In one embodiment, the total content of the oxides of the main cations in the glass compositions expressed in mol % based on the oxides of glasses 1 to 6 can be 90.0% or more.

According to one aspect, there is provided a glass 7 as detailed above.

In one form, the glass 7 can be glass that 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 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)) 0.02 or more,
(3) the ratio of the total content of K ₂ O + CaO + SrO to the BaO content ((K ₂ O + CaO + SrO)/BaO) is 0.12 or more;
(4) The ratio of the total content of K ₂ O, CaO, SrO and ZnO to the total content of MgO and BaO ((K ₂ O+CaO+SrO+ZnO)/(MgO+BaO)) is 0.12 or more.

According to one aspect, there is provided a glass 8 as detailed above.

In one embodiment, the glass 8 has a thickness of 0.23 mm or less, and has an external transmittance of 80% or more at a wavelength of 400 nm and an external transmittance of 80% or more at a wavelength of 1200 nm when converted to a thickness at which the external transmittance is 50% at a wavelength of 625 to 650 nm. The glass may have a transmittance characteristic of a modulus of 5% or less and an average linear expansion coefficient of 130×10 ⁻⁷ /K or less at 100 to 300° C.

In one embodiment, the glasses 1 to 8 have a thickness of 0.25 mm or less at which the half value λ _T 50, which is a wavelength at which the external transmittance including reflection loss is 50% at a wavelength of 550 nm or more, is 633 nm, and the thickness is 0.25 mm or less. , the glass has an external transmittance T600 including reflection loss at a wavelength of 600 nm of 50% or more and an external transmittance T1200 including reflection loss at a wavelength of 1200 nm of 30% or less.

In one embodiment, the glasses 1 to 8 have a thickness of 0.25 mm or less at which the half value λ _T 50, which is a wavelength at which the external transmittance including reflection loss is 50% at a wavelength of 550 nm or more, is 633 nm, and the thickness is 0.25 mm or less. , 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.

In one embodiment, glasses 1 to 8 have a half value λ _T 50, which is a wavelength at which the external transmittance including reflection loss is 50%, is in the range of 600 nm to 650 nm as a transmittance characteristic in terms of thickness of 0.16 mm. The glass may have an external transmittance T1200 including reflection loss at 1200 nm of 30% or less and an external transmittance T400 including reflection loss at a wavelength of 400 nm of 70% or more.

In one embodiment, glasses 1 to 8 have a half value λ _T 50, which is a wavelength at which the external transmittance including reflection loss is 50%, is in the range of 600 nm to 650 nm as a transmittance characteristic in terms of thickness of 0.21 mm. The glass may have an external transmittance T1200 including reflection loss at 1200 nm of 25% or less and an external transmittance T400 including reflection loss at a wavelength of 400 nm of 70% or more.

In one embodiment, the glasses 1 to 8 have a thickness of 0.25 mm or less at which the half value λ _T 50, which is the wavelength at which the external transmittance including reflection loss is 50% at a wavelength of 550 nm or more, is 645 nm, and the thickness is 0.25 mm or less. , the glass has an external transmittance T600 including reflection loss at a wavelength of 600 nm of 50% or more and an external transmittance T1200 including reflection loss at a wavelength of 1200 nm of 30% or less.

In one embodiment, the glasses 1 to 8 have a thickness of 0.25 mm or less at which the half value λ _T 50, which is a wavelength at which the external transmittance including reflection loss is 50% at a wavelength of 550 nm or more, is 645 nm, and the thickness is 0.25 mm or less. , 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.

According to one aspect, there is provided a near-infrared cut filter made of the near-infrared absorbing glass.

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all changes within the scope and meaning equivalent to the scope of the claims.
For example, the near-infrared absorbing glass according to one aspect of the present invention can be obtained by adjusting the composition described in the specification with respect to the glass compositions exemplified above.
In addition, it is of course possible to arbitrarily combine two or more of the matters described as examples or preferred ranges in the specification.

Claims (19)

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; Including 4 or more types,
containing P ions, Ba ions and Cu ions as essential cations,
In the glass composition expressed in anion %, the content of O ions is 90.0 anion % or more,
In the glass composition expressed in atomic %, the ratio of the content of O ions to the content of P ions (O ions/P ions) is 3.15 or less,
In the glass composition expressed in mol% based on oxides,
The total content of B ₂ O ₃ and SiO ₂ (B ₂ O ₃ + SiO ₂ ) is 3.0 mol% or less,
The total content of MgO and Al ₂ O ₃ (MgO + Al ₂ O ₃ ) is 8.0 mol% or less,
the total content of Li ₂ O, Na ₂ O and K ₂ O (Li ₂ O + Na ₂ O + K ₂ O) is 15 mol% or less;
CuO content is α ₁ % or more,
α ₁ has the following formula 1:
(Formula 1)
α ₁ =70400×exp(−2.855×R)
is a value calculated by
In the above formula 1,
R is the ratio (O ions/P ions),
Near-infrared absorption glass. 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; Including 4 or more types,
containing P ions, Ba ions and Cu ions as essential cations,
In the glass composition expressed in anion %, the content of O ions is 90.0 anion % or more,
In the glass composition expressed in atomic %, the ratio of the content of O ions to the content of P ions (O ions/P ions) is 3.15 or less,
In the glass composition expressed in mol% based on oxides,
The total content of B ₂ O ₃ and SiO ₂ (B ₂ O ₃ + SiO ₂ ) is 3.0 mol% or less,
The total content of MgO and Al ₂ O ₃ (MgO + Al ₂ O ₃ ) is 8.0 mol% or less,
the total content of Li ₂ O, Na ₂ O and K ₂ O (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
The filling,
In the above formula 2,
C is the CuO content per molar volume of the glass (unit: millimoles/cc),
R is the ratio (O ions/P ions),
near-infrared absorption glass 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; Including 4 or more types,
containing P ions, Ba ions and Cu ions as essential cations,
In the glass composition expressed in anion %, the content of O ions is 90.0 anion % or more,
In the glass composition expressed in atomic %, the ratio of the content of O ions to the content of P ions (O ions/P ions) is 3.15 or less,
In the glass composition expressed in mol% based on oxides,
The total content of B ₂ O ₃ and SiO ₂ (B ₂ O ₃ + SiO ₂ ) is 3.0 mol% or less,
The total content of MgO and Al ₂ O ₃ (MgO + Al ₂ O ₃ ) is 8.0 mol% or less,
the total content of Li ₂ O, Na ₂ O and K ₂ O (Li ₂ O + Na ₂ O + K ₂ O) is 15 mol% or less;
Equation 3 below:
(Formula 3)
A ₁ = {O(P)−O(others)}×Cu
A ₁ calculated by 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 oxygen content obtained by excluding the O (P) from the oxygen content constituting the oxide of the main cation in the oxide-based glass composition,
Cu indicates the CuO content in mol % in the oxide-based glass composition;
Near-infrared absorption glass. 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; Including 4 or more types,
containing P ions, Ba ions and Cu ions as essential cations,
In the glass composition expressed in anion %, the content of O ions is 90.0 anion % or more,
In the glass composition expressed in atomic %, the ratio of the content of O ions to the content of P ions (O ions/P ions) is 3.15 or less,
In the glass composition expressed in mol% based on oxides,
The total content of B ₂ O ₃ and SiO ₂ (B ₂ O ₃ + SiO ₂ ) is 3.0 mol% or less,
The total content of MgO and Al ₂ O ₃ (MgO + Al ₂ O ₃ ) is 8.0 mol% or less,
the total content of Li ₂ O, Na ₂ O and K ₂ O (Li ₂ O + Na ₂ O + K ₂ O) is 15 mol% or less;
Equation 4 below:
(Formula 4)
A ₂ = {O(P)−O(others)}×C
A ₂ calculated by is 700 or more,
In the above formula 4,
C is the CuO content per molar volume of the 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 oxygen content obtained by excluding the O (P) from the oxygen content constituting the oxide of the main cation in the oxide-based glass composition,
Near-infrared absorption glass. 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; Including 4 or more types,
containing P ions, Ba ions and Cu ions as essential cations,
In the glass composition expressed in anion %, the content of O ions is 90.0 anion % or more,
In the glass composition expressed in atomic %, the ratio of the content of O ions to the content of P ions (O ions/P ions) is 3.15 or less,
In the glass composition expressed in mol% based on oxides,
The total content of B ₂ O ₃ and SiO ₂ (B ₂ O ₃ + SiO ₂ ) is 3.0 mol% or less,
The total content of MgO and Al ₂ O ₃ (MgO + Al ₂ O ₃ ) is 8.0 mol% or less,
the total content of Li ₂ O, Na ₂ O and K ₂ O (Li ₂ O + Na ₂ O + K ₂ O) is 15 mol% or less;
CuO content is α ₂ % or more,
α2 is represented by the following formula ₅ :
(Formula 5)
α ₂ =76522×exp(−2.855×R)
is a value calculated by
In the above formula 5,
R is the ratio (O ions/P ions),
Near-infrared absorption glass. 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; Including 4 or more types,
containing P ions, Ba ions and Cu ions as essential cations,
In the glass composition expressed in anion %, the content of O ions is 90.0 anion % or more,
In the glass composition expressed in atomic %, the ratio of the content of O ions to the content of P ions (O ions/P ions) is 3.15 or less,
In the glass composition expressed in mol% based on oxides,
The total content of B ₂ O ₃ and SiO ₂ (B ₂ O ₃ + SiO ₂ ) is 3.0 mol% or less,
The total content of MgO and Al ₂ O ₃ (MgO + Al ₂ O ₃ ) is 8.0 mol% or less,
the total content of Li ₂ O, Na ₂ O and K ₂ O (Li ₂ O + Na ₂ O + K ₂ O) is 15 mol% or less;
Equation 6 below:
(Formula 6)
C-3478×exp(-2.278×R)≧0
The filling,
In the above formula 6,
C is the CuO content per molar volume of the glass (unit: millimoles/cc),
R is the ratio (O ions/P ions),
Near-infrared absorption glass. In the glass composition expressed in mol% based on oxides,
The ratio of BaO content to Li ₂ O content (BaO/Li ₂ O) is 1.0 or more,
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)) 0.02 or more,
(3) the ratio of the total content of K ₂ O + CaO + SrO to the BaO content ((K ₂ O + CaO + SrO)/BaO) is 0.12 or more;
(4) the ratio of the total content of KO, CaO, SrO and ZnO to the total content of MgO and BaO ((K O ₊ CaO + SrO + ZnO) / (MgO + BaO)) is 0.12 or more;
The near-infrared absorbing glass according to any one of claims 1 to 6, which satisfies one or more of: The near-infrared absorbing glass according to any one of claims 1 to 7, wherein the total content of the oxides of the main cations is 90.0% or more in the glass composition expressed in mol% based on oxides. In the glass composition expressed in mol% based on oxides,
P ₂ O ₅ content is 40.0 to 65.0 mol%,
CuO content is 9.0 to 25.0 mol%,
BaO content is 5.0 to 50.0 mol%,
the total content of Li ₂ O, Na ₂ O and K ₂ O (Li ₂ O + Na ₂ O + K ₂ O) is 1.0 to 15.0 mol%;
_SiO2 content not more than 2.0 mol%,
B ₂ O ₃ content is 2.0 mol% or less,
Al ₂ O ₃ content is 0.5 to 7.0 mol% or less,
Li ₂ O 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 the 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 %, the ratio of the content of O ions to the content of P ions (O ions/P ions) is 3.50 or less,
In the glass composition expressed in anion %, the F ion content is 10.0 anion % or less,
Near-infrared absorption glass. (1) to (4) below:
(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)) 0.02 or more,
(3) the ratio of the total content of K ₂ O + CaO + SrO to the BaO content ((K ₂ O + CaO + SrO)/BaO) is 0.12 or more;
(4) the ratio of the total content of K ₂ O, CaO, SrO and ZnO to the total content of MgO and BaO ((K ₂ O + CaO + SrO + ZnO) / (MgO + BaO)) is 0.12 or more;
The near-infrared absorbing glass according to claim 9, which satisfies one or more of Transmittance with a thickness of 0.25 mm or less and an external transmittance of 75% or more at a wavelength of 400 nm and 7% or less at a wavelength of 1200 nm when converted to a thickness at which the external transmittance is 50% at a wavelength of 620 to 650 nm. A near-infrared absorbing glass having thermal properties and an average linear expansion coefficient of 135×10 ⁻⁷ /K or less at 100 to 300° C. Transmittance with a thickness of 0.23 mm or less and an external transmittance of 80% or more at a wavelength of 400 nm and 5% or less at a wavelength of 1200 nm when converted to a thickness at which the external transmittance is 50% at a wavelength of 625 to 650 nm. 12. The near-infrared absorbing glass according to claim 11, which has a coefficient of thermal expansion and an average coefficient of linear expansion of 130×10 ⁻⁷ /K or less at 100 to 300° C. The thickness of the glass is 0.25 mm or less at which the half value λ _T 50, which is the wavelength at which the external transmittance including reflection loss is 50% at a wavelength of 550 nm or more, is 633 nm,
13. Any one of claims 1 to 12, wherein the thickness has an external transmittance T600 including reflection loss at a wavelength of 600 nm of 50% or more and an external transmittance T1200 including reflection loss at a wavelength of 1200 nm of 30% or less. The near-infrared absorbing glass according to the item. The thickness of the glass is 0.25 mm or less at which the half value λ _T 50, which is the wavelength at which the external transmittance including reflection loss is 50% at a wavelength of 550 nm or more, is 633 nm,
In the 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 the following formula B1:
(Formula B1)
β1=64×R-170
is a value calculated by
In the formula B1,
The near-infrared absorbing glass according to any one of claims 1 to 12, wherein R is the ratio (O ions/P ions). As a transmittance characteristic in terms of thickness of 0.16 mm, the half value λ _T 50, which is the wavelength at which the external transmittance including reflection loss is 50%, is in the range of 600 nm to 650 nm, and 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. As a transmittance characteristic in terms of thickness of 0.21 mm, the half value λ _T 50, which is the wavelength at which the external transmittance including reflection loss is 50%, is in the range of 600 nm to 650 nm, and 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. The thickness of the glass is 0.25 mm or less at which the half value λ _T 50, which is the wavelength at which the external transmittance including reflection loss is 50% at a wavelength of 550 nm or more, is 645 nm,
13. Any one of claims 1 to 12, wherein the thickness has an external transmittance T600 including reflection loss at a wavelength of 600 nm of 50% or more and an external transmittance T1200 including reflection loss at a wavelength of 1200 nm of 30% or less. The near-infrared absorbing glass according to the item. The thickness of the glass is 0.25 mm or less at which the half value λ _T 50, which is the wavelength at which the external transmittance including reflection loss is 50% at a wavelength of 550 nm or more, is 645 nm,
In the 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 β1 is represented by the following formula B1:
(Formula B1)
β1=64×R-170
is a value calculated by
In the formula B1,
The near-infrared absorbing glass according to any one of claims 1 to 12, wherein R is the ratio (O ions/P ions). A near-infrared cut filter comprising the near-infrared absorbing glass according to any one of claims 1 to 18.

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