Optical filter and imaging device

Abstract

To provide an optical filter which offers good visible light transmissivity and suppresses deterioration of near-infrared shielding capability at high incident angles.SOLUTION: An optical filter provide herein comprises an absorptive layer containing a near-infrared absorbing dye and a transparent resin, and a reflective layer, the absorptive layer having a thickness in a range of 0.3-10 μm, and satisfies specific characteristics (1)-(5).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an optical filter that transmits light in the visible wavelength region and blocks light in the near-infrared wavelength region, and an imaging device equipped with the optical filter. [Background technology]

[0002] In order to reproduce color tones well and obtain clear images, imaging devices using solid-state imaging elements use optical filters that transmit light in the visible range (hereinafter also referred to as "visible light") and block light in the near-infrared range (hereinafter also referred to as "near-infrared light"). As such optical filters, near-infrared cut filters are known that include an absorption layer containing a near-infrared absorbent and a reflection layer made of a dielectric multilayer film that blocks near-infrared light. In other words, since the spectral transmittance curve of the dielectric multilayer film itself changes depending on the angle of incidence, a near-infrared cut filter that includes both a reflection layer and an absorption layer can obtain a spectral transmittance curve in which the incidence angle dependency is suppressed due to the absorption characteristics of the absorption layer.

[0003] In recent years, with the miniaturization and high quality of imaging devices, there is a demand for suppressing the incidence angle dependency for light incident at a higher angle. For example, there is a demand for suppressing the occurrence of light leakage, which increases the transmittance of near-infrared light that should have a high reflectance in the wavelength range of 800 to 900 nm at a high incidence angle.

[0004] In the field of near-infrared cut filters, there have been many known techniques that use absorbents that exhibit absorption in the wavelength region of 800 to 900 nm. Specifically, inorganic absorbents such as copper fine particles (e.g., Patent Document 1), cyanine dyes (e.g., Patent Documents 2 to 4), and diimonium dyes are used. (For example, Patent Document 5), phthalocyanine dyes (For example, Patent Documents 6 and 7), squarylium dyes (For example, Patent Document 8), and other dyes are known. For example, near-infrared cut filters that combine a squarylium dye with a cyanine dye or a phthalocyanine dye (for example, Patent Documents 9 and 10) or a tetraazaporphyrin dye with a diimmonium dye (for example, Patent Document 11) are known. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2011 / 071052 [Patent Document 2] Japanese Patent Publication No. 2007-163644 [Patent Document 3] Japanese Patent Publication No. 2015-172102 [Patent Document 4] International Publication No. 2015 / 172004 [Patent Document 5] Japanese Patent Publication No. 2010-266870 [Patent Document 6] Japanese Patent No. 605651 [Patent Document 7] International Publication No. 2015 / 025779 [Patent Document 8] Japanese Patent Publication No. 2016-142891 [Patent Document 9] International Publication No. 2013 / 054864 [Patent Document 10] International Publication No. 2016 / 158461 [Patent Document 11] Japanese Patent Publication No. 2015-1649 Summary of the Invention [Problem to be solved by the invention]

[0006] However, none of the above near-infrared cut filters can achieve both high visible light transmittance and high-level suppression of light leakage in the 800 to 900 nm wavelength region of light with a high angle of incidence.

[0007] The present invention aims to provide an optical filter that maintains good visible light transmittance while suppressing a decrease in near-infrared light blocking ability, particularly at high angles of incidence, and an imaging device that uses the optical filter and has excellent color reproducibility. [Means for solving the problem]

[0008] An optical filter according to one embodiment of the present invention comprises an absorption layer containing a near-infrared absorbing dye and a transparent resin, a reflective layer, and a substrate made of any one of phosphate-based glass, borosilicate glass, alkali-free glass, and a transparent resin, the absorption layer having a thickness of 0.3 to 10 μm, and satisfying all of the following (1) to (5): (1) The average transmittance of light in the wavelength range of 435 to 480 nm at an incident angle of 0 degrees is 70% or more. (2) The average transmittance of light in the wavelength range of 490 to 580 nm at an incident angle of 0 degrees is 84% ​​or more. (3) The average transmittance of light in the wavelength range of 800 to 900 nm at an incident angle of 60 degrees is 0.1% or less. (4) The maximum transmittance of light in the wavelength range of 800 to 900 nm at an incident angle of 60 degrees is 2.1% or less. (5) The wavelength λ on the short wavelength side where the transmittance is 20% at an incident angle of 0 degrees SHT20-0° is in the wavelength range of 640 to 690 nm, and the wavelength λ on the short wavelength side shows a transmittance of 20% at an incident angle of 30 degrees. SHT20-30° and wavelength λ SHT20-0° The difference is less than 10 nm. An optical filter according to another embodiment of the present invention comprises an absorption layer containing at least two or more kinds of near-infrared absorbing dyes and UV dyes and a transparent resin, and a reflection layer, the absorption layer has a thickness of 0.3 to 10 μm, and satisfies all of the following (1) to (5): (1) The average transmittance of light in the wavelength range of 435 to 480 nm at an incident angle of 0 degrees is 70% or more. (2) The average transmittance of light in the wavelength range of 490 to 580 nm at an incident angle of 0 degrees is 84% ​​or more. (3) The average transmittance of light in the wavelength range of 800 to 900 nm at an incident angle of 60 degrees is 0.1% or less. (4) The maximum transmittance of light in the wavelength range of 800 to 900 nm at an incident angle of 60 degrees is 2.1% or less. (5) The wavelength λ on the short wavelength side where the transmittance is 20% at an incident angle of 0 degrees SHT20-0° is in the wavelength range of 640 to 690 nm, and the wavelength λ on the short wavelength side shows a transmittance of 20% at an incident angle of 30 degrees. SHT20-30° and wavelength λ SHT20-0° The difference is less than 10 nm. An optical filter according to another embodiment of the present invention comprises two or more absorbing layers each containing a transparent resin; At least one of the absorbing layers has a thickness of 0.3 to 10 μm, contains a near-infrared absorbing dye, and satisfies all of the following (1) to (5). (1) The average transmittance of light in the wavelength range of 435 to 480 nm at an incident angle of 0 degrees is 70% or more. (2) The average transmittance of light in the wavelength range of 490 to 580 nm at an incident angle of 0 degrees is 84% ​​or more. (3) The average transmittance of light in the wavelength range of 800 to 900 nm at an incident angle of 60 degrees is 0.1% or less. (4) The maximum transmittance of light in the wavelength range of 800 to 900 nm at an incident angle of 60 degrees is 2.1% or less. (5) The wavelength λ on the short wavelength side where the transmittance is 20% at an incident angle of 0 degrees SHT20-0° is in the wavelength range of 640 to 690 nm, and the wavelength λ on the short wavelength side shows a transmittance of 20% at an incident angle of 30 degrees. SHT20-30° and wavelength λ SHT20-0° The difference is less than 10 nm.

[0009] The present invention also provides an imaging device equipped with the optical filter of the present invention. Effect of the Invention

[0010] According to the present invention, the following can be achieved in terms of near-infrared light shielding properties while maintaining good visible light transmittance: In particular, an optical filter can be obtained that suppresses the decrease in the near-infrared light blocking ability at a high incidence angle. Furthermore, according to the present invention, an imaging device that uses the optical filter and has excellent color reproducibility can be provided. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view that illustrates an example of an optical filter according to an embodiment. [Diagram 2] FIG. 2 is a cross-sectional view that illustrates a schematic diagram of another example of the optical filter according to the embodiment. [Diagram 3] FIG. 3 is a cross-sectional view that illustrates a schematic diagram of another example of the optical filter according to the embodiment. [Figure 4] FIG. 4 is a cross-sectional view that illustrates a schematic diagram of another example of the optical filter according to the embodiment. [Diagram 5] FIG. 5 is a cross-sectional view that illustrates a schematic diagram of another example of the optical filter according to the embodiment. [Figure 6] FIG. 6 is a cross-sectional view that illustrates a schematic diagram of another example of the optical filter according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described. In this specification, the near-infrared absorbing dye may be abbreviated as "NIR dye" and the ultraviolet absorbing dye may be abbreviated as "UV dye". In this specification, the compound represented by formula (I) is referred to as compound (I). The same applies to compounds represented by other formulas. The dye consisting of compound (I) is also referred to as dye (I), and the same applies to other dyes. For example, the compound represented by formula (A1) described below is referred to as compound (A1), and the dye consisting of this compound is also referred to as dye (A1). In addition, for example, the group represented by formula (1x) is also referred to as group (1x), and the same applies to groups represented by other formulas.

[0013] In this specification, for a specific wavelength range, a transmittance of, for example, 90% or more means that the transmittance is not below 90% throughout the entire wavelength range, and similarly, a transmittance of, for example, 1% or less means that the transmittance is not above 1% throughout the entire wavelength range. The average transmittance in a specific wavelength range is the arithmetic mean of the transmittances per 1 nm in the wavelength range. In this specification, the term "to" indicating a numerical range includes the upper and lower limits. In this specification, when a certain general formula contains a plurality of substituents represented by the same symbol, these plurality of substituents may be the same or different.

[0014] <Optical filters> An optical filter according to one embodiment of the present invention (hereinafter also referred to as "this filter") has an absorbing layer containing a NIR dye, dye (A), and a transparent resin, and satisfies the following (i-1) to (i-5), and a reflective layer, and satisfies the following (ii-1).

[0015] (i-1) The dye (A) has a maximum absorption wavelength λ in a spectral transmittance curve of 400 to 1100 nm measured after being incorporated into the transparent resin. max(A)TR is in the wavelength range of 760 to 900 nm. (i-2) The dye (A) has a maximum absorption wavelength λ max(A)TR The average transmittance T of light in the wavelength range of 435 to 480 nm is measured in the spectral transmittance curve of 400 to 1100 nm, which is measured by adding the material so that the transmittance at 435-480ave (A)TR and the average transmittance T for light in the wavelength range of 480 to 590 nm 480-590ave(A)TR Both are over 90%. (i-3) Dye (A) has a maximum absorption wavelength λ in the spectral transmittance curve of 400 to 1100 nm when dissolved in dichloromethane and measured. max(A)DCM is in the wavelength range of 760 to 900 nm. (i-4) Dye (A) has a maximum absorption wavelength λ in dichloromethane. max(A)DCMThe average transmittance T of light in the wavelength range of 435 to 480 nm is measured in the spectral transmittance curve of 400 to 1100 nm, which is measured by adding the material so that the transmittance at 435-480ave(A)DCM is 95% or more, and the average transmittance T for light in the wavelength range of 480 to 590 nm 480-590ave(A)DCM is more than 97%. (i-5) The dye (A) has an average transmittance T 435-480ave(A)DCM and average transmittance T 435-480ave(A)TR Difference and average transmittance T 480-590ave(A)DCM and average transmittance T 480-590ave(A)TR The differences are both less than 10.5%.

[0016] (ii-1) The optical filter has an average transmittance of 5% or less for light in the wavelength range of 800 to 900 nm at an incident angle of 60 degrees.

[0017] The present filter has an excellent near-infrared light shielding property and a high visible light transmittance because the absorption layer contains a dye (A) having the characteristics (i-1) to (i-5) and a transparent resin. Furthermore, this filter can suppress the characteristic (ii-1), that is, the incidence angle dependency for light incident at a high angle caused by having a reflective layer. In other words, the deterioration of the near-infrared light shielding property at a high incidence angle can be suppressed.

[0018] It is preferable that the dye (A) further has the following property (i-6): (i-6) The dye (A) has a mass absorption coefficient of 1900 / (cm·mass%) or more when incorporated into the transparent resin. The mass absorption coefficient was calculated by calculating the internal transmittance T [%] of light at the maximum absorption wavelength in the wavelength range of 350 to 1200 nm (= measured transmittance [%] / (100-measured reflectance [%]) × 100 [%]), and then subtracting the log 10 (T / 100). Hereinafter, unless otherwise specified, the "mass absorption coefficient" of a dye is the mass absorption coefficient calculated by the above method.

[0019] The filter may further include a transparent substrate. In this case, the absorbing layer and the reflecting layer are provided on the main surface of the transparent substrate. The filter may include the absorbing layer and the reflecting layer on the same main surface of the transparent substrate, or may include the absorbing layer and the reflecting layer on different main surfaces. When the absorbing layer and the reflecting layer are provided on the same main surface, the stacking order of these layers is not particularly limited.

[0020] The filter may also have other functional layers. Examples of such functional layers include an anti-reflection layer that suppresses the loss of visible light transmittance. In particular, when the absorbing layer is configured as the outermost surface, a loss of visible light transmittance occurs due to reflection at the interface between the absorbing layer and air, so it is advisable to provide an anti-reflection layer on the absorbing layer.

[0021] Next, a configuration example of this filter will be described with reference to the drawings. Fig. 1 shows a configuration example of an optical filter 10A having a reflective layer 12 on one main surface of an absorbing layer 11. In the optical filter 10A, the absorbing layer 11 can be composed of a layer containing a dye (A) and a transparent resin. Note that "having a reflective layer 12 on one main surface (top) of the absorbing layer 11" does not only mean a case where the reflective layer 12 is provided in contact with the absorbing layer 11, but also includes a case where another functional layer is provided between the absorbing layer 11 and the reflective layer 12, and the same applies to the following configurations.

[0022] 2 is a cross-sectional view that shows a schematic example of an optical filter having a transparent substrate, an absorbing layer, and a reflective layer. The optical filter 10B has a transparent substrate 13, an absorbing layer 11 disposed on one of the main surfaces of the transparent substrate 13, and a reflective layer 12 disposed on the other main surface of the transparent substrate 13. In the optical filter 10B, the absorbing layer 11 can be composed of a layer containing a dye (A) and a transparent resin.

[0023] FIG. 3 shows an example of the configuration of an optical filter 10C that includes an absorbing layer 11 and reflective layers 12a and 12b on both main surfaces of the absorbing layer 11, respectively. FIG. 4 shows an example of the configuration of an optical filter 10D having an absorbing layer 11 on one main surface of a transparent substrate 13, and reflective layers 12a and 12b on the other main surface of the transparent substrate 13 and the main surface of the absorbing layer 11. FIG. 5 shows an example of the configuration of an optical filter 10E that includes absorbing layers 11a and 11b on both main surfaces of a transparent substrate 13, and further includes reflective layers 12a and 12b on the main surfaces of the absorbing layers 11a and 11b.

[0024] In Figures 3, 4 and 5, the two reflective layers 12a and 12b to be combined may be the same or different. For example, the reflective layers 12a and 12b may reflect ultraviolet light and near infrared light, The reflecting layer 12a has a property of transmitting visible light, and reflects ultraviolet light and light in a first near-infrared range, The reflective layer 12b may be configured to reflect ultraviolet light and the second near-infrared light.

[0025] 5, the two absorbing layers 11a and 11b may be the same or different. When the absorbing layers 11a and 11b are different, for example, the absorbing layers 11a and 11b may each be a combination of a near-infrared absorbing layer and an ultraviolet absorbing layer, or a combination of an ultraviolet absorbing layer and a near-infrared absorbing layer.

[0026] Fig. 6 shows an example of the configuration of an optical filter 10F having an antireflection layer 14 on the main surface of the absorbing layer 11 of the optical filter 10B shown in Fig. 2. When no reflective layer is provided and the absorbing layer is configured as the outermost surface, it is preferable to provide an antireflection layer on the absorbing layer. The antireflection layer may be configured to cover not only the outermost surface of the absorbing layer but also the entire side surface of the absorbing layer. In this case, the moisture-proof effect of the absorbing layer can be improved.

[0027] The absorbing layer, the reflective layer, the transparent substrate and the anti-reflection layer will now be described. (Absorption layer) The absorbing layer contains a dye (A) having the above characteristics (i-1) to (i-5), and preferably further having the above characteristic (i-6), and a transparent resin.

[0028] The absorbing layer is typically a layer in which the dye (A) is uniformly dissolved or dispersed in a transparent resin. (Resin) substrate. The absorbing layer may contain other NIR dyes in addition to the dye (A) as long as the effect of the present invention is not impaired. Furthermore, the absorbing layer may contain dyes other than the NIR dye, particularly UV dyes, as long as the effect of the present invention is not impaired.

[0029] As the other NIR dye, it is preferable to contain a dye (D) that satisfies the following requirement (iii-1). (iii-1) The dye (D) has a maximum absorption wavelength λ in a spectral transmittance curve of 400 to 1100 nm measured after being incorporated into the transparent resin. max(D)TR is in the wavelength range of 680 to 750 nm.

[0030] Furthermore, it is preferable that the dye (D) satisfies the following requirement (iii-2): (iii-2) The dye (D) has a maximum absorption wavelength λ max(D)TR In the spectral transmittance curve for a wavelength of 400 to 1100 nm measured when the composition is contained at a concentration such that the transmittance of the resin is 10%, the average transmittance of light in the wavelength region of 400 to 500 nm is 85% or more.

[0031] In addition, in the spectral transmittance curve of the internal transmittance at wavelengths of 350 to 1200 nm measured by incorporating the dye (D) into the transparent resin, λ max(D)TR The absorption peak with the absorption apex at λ max(D)TR The absorption peak of the visible light spectrum (called the "absorption peak of the visible light spectrum") has a steep slope on the visible light side, that is, the wavelengths from 70% transmittance to 20% transmittance on the visible light side are It is preferably 60 nm or less, and more preferably 50 nm or less.

[0032] [Dye (A)] The dye (A) has a maximum absorption wavelength λ max(A)TR The maximum absorption wavelength λ is in the wavelength range of 760 to 900 nm. max(A)TR is preferably in the wavelength region of 760 to 860 nm.

[0033] The dye (A) has an average transmittance T 435-480ave(A)TR and the average transmittance T480-590ave(A)TR Both are 90% or more. 435-480ave(A)TR is preferably 91% or more, and the average transmittance T 480-590ave(A)TR is preferably 92% or more.

[0034] The dye (A) has a maximum absorption wavelength λ max(A)DCM The maximum absorption wavelength λ is in the wavelength range of 760 to 900 nm. max(A)DCM is preferably in the wavelength region of 760 to 860 nm.

[0035] In (i-4), the dye (A) has an average transmittance T 435-480ave(A)DCM is 95% or more, and the average transmittance T 480-590ave(A)DCM The average transmittance T is 97% or more. 435-480ave(A)DCM is preferably 97% or more, and the average transmittance T 480-590ave(A)DCM 99% or higher is preferred.

[0036] The dye (A) has an average transmittance T 435-480ave(A)DCM and average transmittance T 435-480ave(A)TR Difference and average transmittance T 480-590ave(A)DCM and average transmittance T 480-590ave(A)TR The difference between the average transmittance T 435-480ave(A)DCM and average transmittance T 435-480ave(A)TR The difference between the average transmittance T 480-590ave(A)DCM and average transmittance T 480-590ave(A)TR The difference is preferably 5% or less.

[0037] For the dye (A), satisfying (i-5) means that the transmittance of visible light in dichloromethane can be maintained even in a transparent resin when used in an optical filter. In general, it is known that a dye with a large maximum absorption wavelength has a contribution from aggregation, and it is difficult to reproduce the sharp spectrum in dichloromethane in a transparent resin. The dye (A) satisfies the above (i-1) to (i-5). By satisfying (i-5), the compound has the characteristic of having a large maximum absorption wavelength and a high transmittance of visible light in dichloromethane, while being able to maintain the absorption characteristics even in a transparent resin.

[0038] The dye (A) in (i-6) has a mass absorption coefficient of 1900 / (cm·mass%) or more, and preferably has a mass absorption coefficient of 2000 / (cm·mass%) or more.

[0039] The dye (A) is not particularly limited in molecular structure as long as it satisfies the requirements (i-1) to (i-5). Specific examples include cyanine dyes. More specifically, the dye (A) is preferably a cyanine dye represented by the following formula (A1) or formula (A2).

[0040] [ka]

[0041] In the formulae (A1) and (A2), the symbols are as follows: R 101 ~R 109 and R 121 ~R 131 R each independently represents a hydrogen atom, a halogen atom, an alkyl group or alkoxy group having 1 to 15 carbon atoms which may have a substituent, or an aryl group having 5 to 20 carbon atoms. 110 ~ 114 and R 132 ~ 136 each independently represents a hydrogen atom, a halogen atom, or an alkyl or alkoxy group having 1 to 15 carbon atoms. Multiple R in each formula 101 ~R 109 and R 121 ~R 131 may be the same as or different from each other. X - indicates a monovalent anion. n1 and n2 are 0 or 1. -(CH2) n1 Carbocycles containing - and -(CH2) n2 A hydrogen atom bonded to a carbon ring containing - may be substituted with a halogen atom, an alkyl group having 1 to 15 carbon atoms which may have a substituent, or an aryl group having 5 to 20 carbon atoms.

[0042] In the above, the alkyl group (including the alkyl group of the alkoxy group) may be linear or may have a branched structure or a saturated ring structure. The aryl group refers to a group that bonds via a carbon atom constituting an aromatic ring of an aromatic compound, such as a benzene ring, a naphthalene ring, a biphenyl, a furan ring, a thiophene ring, a pyrrole ring, etc. Examples of the substituent in the alkyl group or alkoxy group having 1 to 15 carbon atoms or the aryl group having 5 to 20 carbon atoms that may have a substituent include a halogen atom and an alkoxy group having 1 to 10 carbon atoms.

[0043] In formula (A1) and formula (A2), R 102 ~R 105 , R 108 , R 109 , R 122 ~R 127 , R 130 and R 131 are each independently preferably a hydrogen atom, an alkyl or alkoxy group having 1 to 15 carbon atoms, or an aryl group having 5 to 20 carbon atoms, and more preferably a hydrogen atom from the viewpoint of obtaining a high visible light transmittance.

[0044] In formula (A1) and formula (A2), R 110 ~R 114 and R 132 ~R 136 are each independently preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms, and more preferably a hydrogen atom from the viewpoint of obtaining a high visible light transmittance.

[0045] R 106 , R 107 , R 128 and R 129 are each independently preferably a hydrogen atom, an alkyl group having 1 to 15 carbon atoms, or an aryl group having 5 to 20 carbon atoms (which may include a linear, cyclic, or branched alkyl group), more preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms. 106 and R 107 , R 128 and R 129 are preferably the same group.

[0046] R101 and R 121 is preferably an alkyl group having 1 to 15 carbon atoms or an aryl group having 5 to 20 carbon atoms, and more preferably a branched alkyl group having 1 to 15 carbon atoms from the viewpoint of maintaining high visible light transmittance in the transparent resin as in the solution.

[0047] X - As for I - , BF4 - , PF6 - , ClO4 - , anions represented by formulas (X1) and (X2), etc., preferably BF4 - , or PF6 - It is.

[0048] [ka]

[0049] In the following description, R 101 ~R 114 The portion excluding is also called the skeleton (A1). The same applies to other dyes.

[0050] In formula (A1), a compound where n1 is 1 is represented by the following formula (A11), and a compound where n1 is 0 is represented by the following formula (A12). As shown in (A12).

[0051] [ka]

[0052] In formula (A11) and formula (A12), R 101 ~R 114 and X - is the same as in formula (A1). 115 ~R 120 each independently represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group having 1 to 15 carbon atoms which may have a substituent, or It represents an aryl group having 5 to 20 carbon atoms. A hydrogen atom, an alkyl group having 1 to 15 carbon atoms, or an aryl group having 5 to 20 carbon atoms (which may include a linear, cyclic, or branched alkyl group) is preferable, and a hydrogen atom or an alkyl group having 1 to 15 carbon atoms is more preferable. 115 ~R 120 are preferably the same group.

[0053] In formula (A2), a compound where n2 is 1 is represented by the following formula (A21), and a compound where n2 is 0 is represented by the following formula (A22). As shown in (A22).

[0054] [ka]

[0055] In formula (A21) and formula (A22), R 121 ~R 136 and X - is the same as in formula (A2). 137 ~R 142 each independently represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group having 1 to 15 carbon atoms which may have a substituent, or It represents an aryl group having 5 to 20 carbon atoms. A hydrogen atom, an alkyl group having 1 to 15 carbon atoms, or an aryl group having 5 to 20 carbon atoms (which may include a linear, cyclic, or branched alkyl group) is preferable, and a hydrogen atom or an alkyl group having 1 to 15 carbon atoms is more preferable. 137 ~R 142 are preferably the same group.

[0056] More specifically, the compounds represented by formula (A11), formula (A12), formula (A21), and formula (A22) each include compounds in which the atom or group bonded to each skeleton is shown in the following Tables 1 to 4. In all of the compounds shown in Tables 1 and 2, R 101 ~R 109 are all the same on the left and right sides of the formula. In all compounds shown in Tables 3 and 4, R 121 ~R 131are the same on the left and right sides of the formula. Although only symmetrical compounds are listed in Tables 1 to 4, the present invention is not limited thereto, and may be an asymmetrical compound. Asymmetrical compounds have the advantage of improving solubility in resins.

[0057] R in Tables 1 and 2 110 -R 114 and R in Tables 3 and 4 132 -R 136 R indicates an atom or group bonded to the central benzene ring of each formula, and when all five are hydrogen atoms, it is written as "H". 110 -R 114 When one of the groups is a substituent and the other is a hydrogen atom, only the combination of the symbol and the substituent is described. For example, "R 112 -C(CH3)3" is R 112 R is -C(CH3)3 and the rest are hydrogen atoms. 132 -R 136 The same applies to.

[0058] R in Table 1 115 -R 120 and R in Table 3 137 -R 142 R represents an atom or group bonded to the central cyclohexane ring in formula (A11) or formula (A21), and when all six are hydrogen atoms, it is written as "H". 115 -R 120 When one of the groups is a substituent and the other is a hydrogen atom, only the combination of the symbol and the substituent is shown. 137 -R 142 The same applies to.

[0059] R in Table 2 115 -R 118 and R in Table 4 137 -R 140 R represents an atom or group bonded to the central cyclopentane ring in formula (A12) or formula (A22), and when all four are hydrogen atoms, it is written as "H". 115 -R 118When one of the groups is a substituent and the other is a hydrogen atom, only the combination of the symbol and the substituent is shown. 137 -R 140 The same applies to.

[0060] Tables 1 to 4 show X - However, in all compounds, X - is BF4 - or PF6 - In the dye (A11-1), X - But BF4 - In the case of dye (A11-1B), PF6 - This case is referred to as dye (A11-1P). The same applies to the other dyes shown in Tables 1 to 4. In Tables 1 to 4, -C3H7 and -C4H9 represent linear propyl and butyl groups, respectively.

[0061] [Table 1]

[0062] Among these, the dye (A11) is preferably selected from the following in terms of solubility in a transparent resin or a solvent used in forming an absorbing layer on a transparent substrate (hereinafter also referred to as a "host solvent") and visible light transmittance: Preferred are dye (A11-1B), dye (A11-1P), dye (A11-2B), dye (A11-2P), dye (A11-3B), dye (A11-3P), dye (A11-4B), dye (A11-4P), dye (A11-5B), dye (A11-5P), and the like.

[0063] [Table 2]

[0064] Among these, the dye (A12) is preferably selected from the following in terms of solubility in a transparent resin or a solvent used in forming an absorbing layer on a transparent substrate (hereinafter also referred to as a "host solvent") and visible light transmittance: Preferred are dye (A12-1B), dye (A12-1P), dye (A12-2B), dye (A12-2P), dye (A12-3B), dye (A12-3P), dye (A12-4B), dye (A12-4P), dye (A12-5B), dye (A12-5P), and the like.

[0065] [Table 3]

[0066] Among these, the dye (A21) is preferably selected from the following in terms of solubility in a transparent resin or a solvent used in forming an absorbing layer on a transparent substrate (hereinafter also referred to as a "host solvent") and visible light transmittance: Preferred are dye (A21-1B), dye (A21-1P), dye (A21-2B), dye (A21-2P), dye (A21-3B), dye (A21-3P), dye (A21-4B), dye (A21-4P), dye (A21-5B), dye (A21-5P), and the like.

[0067] [Table 4]

[0068] Among these, the dye (A22) is preferably selected from the following in terms of solubility in a transparent resin or a solvent used in forming an absorbing layer on a transparent substrate (hereinafter also referred to as a "host solvent") and visible light transmittance: Preferred are dye (A22-1B), dye (A22-1P), dye (A22-2B), dye (A22-2P), dye (A22-3B), dye (A22-3P), dye (A22-4B), dye (A22-4P), dye (A22-5B), dye (A22-5P), and the like.

[0069] As described above, the skeletons of dyes (A1) and (A2) are different, and therefore the maximum absorption wavelength λ max(A)TR In the dye (A1), the maximum absorption wavelength λ varies depending on the types and combinations of atoms and groups bonded to the skeleton (A1). max(A1)TRIn the dye (A2), the maximum absorption wavelength λ is in the wavelength range of about 760 to 830 nm, depending on the types and combinations of atoms and groups bonded to the skeleton (A2). max(A2)TR However, it is generally in the wavelength range of 800 to 900 nm.

[0070] Furthermore, in the dye (A1), the maximum absorption wavelength λ max(A1)TR In the dye (A11), the maximum absorption wavelength λ varies depending on the types and combinations of atoms and groups bonded to the skeleton (A11). max(A11)TR However, the wavelengths of the dye (A12) are in the range of about 760 to 800 nm. Although it depends on the types and combinations of atoms and groups bonded to the skeleton (A12), the maximum absorption wavelength λ max(A12)TR However, it is generally in the wavelength range of 800 to 830 nm.

[0071] Similarly, for dye (A2), the maximum absorption wavelength λ max(A2)TR In the dye (A21), the maximum absorption wavelength λ depends on the types and combinations of atoms and groups bonded to the skeleton (A21). max(A21)TR In the dye (A22), the maximum absorption wavelength λ is in the wavelength range of about 800 to 830 nm, depending on the types and combinations of atoms and groups bonded to the skeleton (A22). max(A22)TR However, it is generally in the wavelength range of 830 to 900 nm.

[0072] The absorbing layer may contain one type of dye (A) alone or two or more types in combination. When two or more types are contained, the maximum absorption wavelength λ of each dye (A) is max(A)TR It is preferable that the maximum absorption wavelength λ of two or more dyes (A) is different. max(A)TR The difference is, for example, preferably in the range of 20 to 60 nm, more preferably 30 to 50 nm. When the dye (A) is composed of two or more compounds, each compound does not necessarily have the properties of the dye (A), and the compounds as a mixture may have the properties of the dye (A).

[0073] As a preferred combination of two or more kinds of dyes (A), it is preferred to select and combine two or more kinds from dyes S, dye M and dye L, where dye (A11) having a maximum absorption wavelength on the relatively short wavelength side among dyes (A), dye (A22) having a maximum absorption wavelength on the relatively long wavelength side, and dye (A12) or dye (A21) having a maximum absorption wavelength between the maximum absorption wavelengths of dyes S and L, as dye M.

[0074] Specifically, the combination of dye S and dye M, the combination of dye S and dye L, the combination of dye M and dye L, and the combination of dye S, dye M, and dye L are given. The maximum absorption wavelength λ of dye S is max(A)TR The maximum absorption wavelength λ of dye M is preferably in the wavelength range of 765 to 785 nm, and more preferably in the wavelength range of 770 to 780 nm. max(A)TR The maximum absorption wavelength λ of dye L is preferably in the wavelength range of 795 to 815 nm, and more preferably in the wavelength range of 800 to 810 nm. max(A)TR is preferably in the wavelength region of 820 to 850 nm, and more preferably in the wavelength region of 830 to 850 nm.

[0075] The dye (A1) and the dye (A2) can be, for example, 73 (2007) 344-352 and J. Heterocyclic Chem, 42, 959 (2005). In addition, the dye (A11-5P) and the dye (A21-5P) can be commercially available products manufactured by Few Chemicals under the trade names S2138 and S2139.

[0076] [Dye (D)] The dye (D) satisfies the requirement (iii-1) and preferably further satisfies the requirement (iii-2), and may be at least one dye selected from the group consisting of a cyanine dye, a phthalocyanine dye, a naphthalocyanine dye, a dithiol metal complex dye, a diimonium dye, a polymethine dye, a phthalide dye, a naphthoquinone dye, an anthraquinone dye, an indophenol dye, and a squarylium dye.

[0077] Among these, squarylium dyes that satisfy the requirement (iii-1), and preferably the requirement (iii-2), are particularly preferred. The squarylium dye (D) has low visible light absorption in the above absorption spectrum, and has a wavelength of λ max(D)TR The absorption peak of the compound has a steep slope on the visible light side, and the compound has high storage stability and stability against light.

[0078] As a squarylium dye (D), λ max(D)TR A compound represented by any one of formulas (I) to (III) having a wavelength region of 680 to 750 nm is preferred. The dye (D) preferably has a mass absorption coefficient of 1000 / (cm·mass%) or more, and more preferably 1500 / (cm·mass%) or more when incorporated into a transparent resin.

[0079] [ka]

[0080] In the formula (I), the symbols are as follows: R 24 and R 26 each independently represents a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group or an alkoxy group having 1 to 6 carbon atoms, an acyloxy group having 1 to 10 carbon atoms, -NR 27 R 28 (R 27 and R 28 are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, -C(=O)-R 29 (R 29 represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 11 carbon atoms, or an aryl group having 7 to 18 carbon atoms which may have a substituent and which may have an oxygen atom between the carbon atoms), -NHR 30 , or -SO2-R 30 (R 30represents a hydrocarbon group having 1 to 25 carbon atoms, each of which may have one or more hydrogen atoms substituted with a halogen atom, a hydroxyl group, a carboxy group, a sulfo group, or a cyano group, and which may contain an unsaturated bond, an oxygen atom, or a saturated or unsaturated ring structure between carbon atoms), or a group represented by the following formula (S) (R 41 , R 42 each independently represents a hydrogen atom, a halogen atom, or an alkyl or alkoxy group having 1 to 10 carbon atoms. k is 2 or 3.

[0081] [ka]

[0082] R 21 and R 22 , R 22 and R 25 , and R 21 and R 23 may be linked to each other to form, together with the nitrogen atom, a 5- or 6-membered heterocycle A, heterocycle B, and heterocycle C, respectively. R when heterocycle A is formed 21 and R 22 represents a divalent group -Q- to which these are bonded, which is an alkylene group or an alkyleneoxy group in which the hydrogen atom may be substituted with an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an acyloxy group having 1 to 10 carbon atoms which may have a substituent.

[0083] R when heterocycle B is formed 22 and R 25 and R when a heterocycle C is formed. 21 and R 23 are the divalent groups -X 1 -Y 1 -and-X 2 -Y 2 - (The side that is bonded to nitrogen is X 1 and X 2 ) as X 1 and X 2are groups represented by the following formula (1x) or (2x), and Y 1 and Y 2 Each of X is a group selected from the following formulas (1y) to (5y). 1 and X 2 are groups represented by the following formula (2x), Y 1 and Y 2 may each be a single bond, in which case: An oxygen atom may be present between the carbon atoms.

[0084] [ka]

[0085] In formula (1x), the four Z's each independently represent a hydrogen atom, a hydroxyl group, an alkyl group or an alkoxy group having 1 to 6 carbon atoms, or -NR 38 R 39 (R 38 and R 39 R each independently represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. 31 ~R 36 each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 10 carbon atoms; R 37 represents an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms.

[0086] R 27 , R 28 , R 29 , R 31 ~R 37 , R when not forming a heterocycle 21 ~R 23 , and R 25 may be bonded to any other of these to form a 5- or 6-membered ring. 31 and R 36 , R 31 and R 37 may be directly bonded. When R does not form a heterocycle 21 and R 22each independently represents a hydrogen atom, an alkyl group or an aryl group having 1 to 6 carbon atoms which may have a substituent, or an aryl group or an arylaryl group having 6 to 11 carbon atoms which may have a substituent. 23 and R 25 each independently represents a hydrogen atom, a halogen atom, or an alkyl or alkoxy group having 1 to 6 carbon atoms.

[0087] [ka]

[0088] In the formula (II), the symbols are as follows: each ring Z is independently an optionally substituted 5- or 6-membered ring having 0 to 3 heteroatoms in the ring; R 1 and R 2 , R 2 and R 3 , and R 1 and the carbon atoms or heteroatoms constituting ring Z are may be linked together to form a heterocycle A1, a heterocycle B1, or a heterocycle C1 together with the nitrogen atom, respectively. When no heterocycle is formed, R 1 and R 2 each independently represents a hydrogen atom, a halogen atom, or a hydrocarbon group which may contain an unsaturated bond between carbon atoms, a heteroatom, or a saturated or unsaturated ring structure and which may have a substituent; R 3 and R 4 each independently represents a hydrogen atom, a halogen atom, or an alkyl or alkoxy group which may contain a heteroatom between carbon atoms.

[0089] [ka]

[0090] In the formula (III), the symbols are as follows: R 51each independently represents a halogen atom or an alkyl group having 1 to 3 carbon atoms which may have a substituent, R 52 ~R 58 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 10 carbon atoms which may have a substituent. R 52 and R 53 may be linked together to form a saturated or unsaturated hydrocarbon ring B2 having 5 to 15 carbon atoms, and a hydrogen atom of the hydrocarbon ring B2 may be substituted with an alkyl group having 1 to 10 carbon atoms, R 54 and R 55 may be linked to each other to form a benzene ring A2, and a hydrogen atom of the benzene ring A2 may be substituted with an alkyl group having 1 to 10 carbon atoms.

[0091] Examples of compound (I) include compounds represented by any of formulas (I-1) to (I-4).

[0092] [ka]

[0093] However, the symbols in formulae (I-1) to (I-4) have the same definitions as those of the same symbols in formula (I), and preferred embodiments are also the same.

[0094] Among the compounds (I-1) to (I-4), the dye (A) is preferably the compounds (I-1) to (I-3), from the viewpoint of increasing the visible light transmittance of the absorbing layer, and more preferably the compound (I-1).

[0095] In compound (I-1), X 1 As the group (2x), the group (2x) is preferable. 1 is preferably a single bond or a group (1y). In this case, R 31 ~R 36 is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom or a methyl group. -Y1 -X 1 Specific examples of - include divalent organic groups represented by the formulas (11-1) to (12-3).

[0096] -C(CH3)2-CH(CH3)- …(11-1) -C(CH3)2-CH2- …(11-2) -C(CH3)2-CH(C2H5)- …(11-3) -C(CH3)2-C(CH3)(nC3H7)- …(11-4) -C(CH3)2-CH2-CH2- …(12-1) -C(CH3)2-CH2-CH(CH3)- …(12-2) -C(CH3)2-CH(CH3)-CH2- …(12-3)

[0097] In addition, in compound (I-1), R 21 From the viewpoints of solubility, heat resistance, and the steepness of the change in the spectral transmittance curve near the boundary between the visible region and the near infrared region, each of the formulas (4-1) or (4-2) is more preferred.

[0098] [ka]

[0099] In formula (4-1) and formula (4-2), R 71 ~R 75 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms.

[0100] In compound (I-1), R 24 Ha-NR 27 R 28 -NR 27 R 28 From the viewpoint of solubility in host solvents and transparent resins, -NH-C(=O)-R 29 In compound (I-1), R 24 -NH-C(=O)-R 29 The compound is shown in formula (I-11).

[0101] [ka]

[0102] In compound (I-11), R 23 and R 26 are each preferably independently a hydrogen atom, a halogen atom, or an alkyl or alkoxy group having 1 to 6 carbon atoms, and more preferably a hydrogen atom.

[0103] In compound (I-11), R 29 Preferred examples of the group include an alkyl group having 1 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 10 carbon atoms which may have a substituent, or an araryl group having 7 to 18 carbon atoms which may have a substituent and which may have an oxygen atom between the carbon atoms. Examples of the substituent include a halogen atom such as a fluorine atom, a hydroxyl group, a carboxy group, a sulfo group, a cyano group, an alkyl group having 1 to 6 carbon atoms, a fluoroalkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and an acyloxy group having 1 to 6 carbon atoms.

[0104] R 29 As the alkyl group, a group selected from a linear, branched or cyclic alkyl group having 1 to 17 carbon atoms which may be substituted with a fluorine atom, a phenyl group which may be substituted with a fluoroalkyl group having 1 to 6 carbon atoms and / or an alkoxy group having 1 to 6 carbon atoms, and an araryl group having 7 to 18 carbon atoms which may have an oxygen atom between the carbon atoms and which has a phenyl group which may be substituted with an alkyl group having 1 to 6 carbon atoms at its terminal which may be substituted with a fluorine atom and / or an alkoxy group having 1 to 6 carbon atoms, is preferred.

[0105] R 29 As R, a hydrocarbon group having 5 to 25 carbon atoms and at least one branch, in which one or more hydrogen atoms may be independently substituted with a halogen atom, a hydroxyl group, a carboxy group, a sulfo group, or a cyano group, and which may contain an unsaturated bond, an oxygen atom, or a saturated or unsaturated ring structure between carbon atoms, can also be preferably used.29 Examples of the group include groups represented by the following formulae (1a), (1b), (2a) to (2e), and (3a) to (3e).

[0106] [ka]

[0107] [ka]

[0108] More specifically, examples of compound (I-11) include the compounds shown in Table 5 below. In Table 5, the group (11-1) is shown as (11-1). The same applies to other groups. The groups are shown in the same way in the other tables below. In addition, in all of the compounds shown in Table 5, the symbols on the left and right of the squarylium skeleton have the same meaning. The same applies to the squarylium dyes shown in the other tables below.

[0109] [Table 5]

[0110] In compound (I-1), R 24 From the viewpoint of increasing the transmittance of visible light, especially the transmittance of light having a wavelength of 430 to 550 nm, -NH-SO2-R 30 In compound (I-1), R 24 -NH-SO2-R 30 The compound is shown in formula (I-12).

[0111] [ka]

[0112] In compound (I-12), R 23 and R 26are each preferably independently a hydrogen atom, a halogen atom, or an alkyl or alkoxy group having 1 to 6 carbon atoms, and more preferably a hydrogen atom.

[0113] In compound (I-12), R 30 From the viewpoint of light resistance, each of the groups is preferably an alkyl group or alkoxy group having 1 to 12 carbon atoms, which may have a branch, or a hydrocarbon group having 6 to 16 carbon atoms and an unsaturated ring structure. Examples of the unsaturated ring structure include benzene, toluene, Examples include xylene, furan, and benzofuran. 30 are more preferably independently an alkyl or alkoxy group having 1 to 12 carbon atoms which may have a branch. 30 In each group represented by the formula (I-12), some or all of the hydrogen atoms may be substituted with halogen atoms, particularly fluorine atoms. When the present filter includes a transparent substrate, the substitution of hydrogen atoms with fluorine atoms is to such an extent that the adhesion between the absorbing layer containing the dye (I-12) and the transparent substrate is not deteriorated.

[0114] R having an unsaturated ring structure 30 Specific examples of the alkyl group include groups represented by the following formulas (P1) to (P8).

[0115] [ka]

[0116] More specifically, examples of compound (I-12) include the compounds shown in Table 6 below.

[0117] [Table 6]

[0118] Examples of compound (II) include compounds represented by any of formulas (II-1) to (II-3).

[0119] [ka]

[0120] In the formula (II-1) and the formula (II-2), R 1 and R 2 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 15 carbon atoms which may have a substituent; R 3 ~R 6 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 10 carbon atoms which may have a substituent.

[0121] In the formula (II-3), R 1 , R 4 , and R 9 ~R 12 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 15 carbon atoms which may have a substituent; R 7 and R 8 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 5 carbon atoms which may have a substituent.

[0122] R in compound (II-1) and compound (II-2) 1 and R 2 From the viewpoints of solubility in a transparent resin, visible light transmittance, and the like, each independently represents preferably an alkyl group having 1 to 15 carbon atoms, more preferably an alkyl group having 7 to 15 carbon atoms; R 1 and R 2 More preferably, at least one of R is a branched alkyl group having 7 to 15 carbon atoms. 1 and R 2 It is particularly preferable that both of the groups are alkyl groups having a branched chain and having 8 to 15 carbon atoms.

[0123] R 3 From the viewpoints of solubility in a transparent resin, visible light transmittance, etc., R are each preferably a hydrogen atom, a halogen atom, or an alkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom, a halogen atom, or a methyl group. 4From the viewpoint of the sharpness of the change in the vicinity of the boundary between the visible region and the near infrared region, R is preferably a hydrogen atom or a halogen atom, and particularly preferably a hydrogen atom. 5 and R in compound (II-2) 6 are each preferably a hydrogen atom, a halogen atom, or an alkyl group having 1 to 5 carbon atoms which may be substituted with a halogen atom, and more preferably a hydrogen atom, a halogen atom, or a methyl group.

[0124] More specifically, the compounds (II-1) and (II-2) are shown in Tables 7 and 8 below. 17 , -C4H9, -C6H 13 indicate a linear octyl group, a butyl group, and a hexyl group, respectively.

[0125] [Table 7]

[0126] [Table 8]

[0127] R in compound (II-3) 1 From the viewpoints of solubility in transparent resins, visible light transmittance, and the like, each independently is preferably an alkyl group having 1 to 15 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms, and particularly preferably an ethyl group or an isopropyl group.

[0128] R 4 From the viewpoints of visible light transmittance and ease of synthesis, R is preferably a hydrogen atom or a halogen atom, and particularly preferably a hydrogen atom. 7 and R 8 are each preferably a hydrogen atom, a halogen atom, or an alkyl group having 1 to 5 carbon atoms which may be substituted with a halogen atom, and more preferably a hydrogen atom, a halogen atom, or a methyl group.

[0129] R 9 ~R 12 are preferably independently a hydrogen atom, a halogen atom, or an alkyl group having 1 to 5 carbon atoms which may be substituted with a halogen atom. 9 R 10 -CR 11 R 12 Examples of - include the above groups (11-1) to (11-3) and divalent organic groups of the following formula (11-5). -C(CH3)(CH2-CH(CH3)2)-CH(CH3)-…(11-5)

[0130] More specifically, examples of compound (II-3) include the compounds shown in Table 9 below.

[0131] [Table 9]

[0132] Examples of compound (III) include compounds represented by formula (III-1) or formula (III-2).

[0133] [ka]

[0134] However, in (III-1) and (III-2), R 52 ~R 62 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 10 carbon atoms which may have a substituent.

[0135] In compound (III-1) and compound (III-2), R 52 , R 53 are each preferably a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may be substituted with a halogen atom, and more preferably a hydrogen atom, a halogen atom, or a methyl group. 58 teeth, A hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may be substituted with a halogen atom is preferred, and from the viewpoint of ease of synthesis, an alkyl group having 1 to 3 carbon atoms is more preferred. 56 , R 57 , R 59 ~R 62 are each preferably independently a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a substituent, and from the viewpoint of ease of synthesis, A hydrogen atom is more preferable. More specific examples of compound (III-1) and compound (III-2) include the compounds shown in Tables 10 and 11 below, respectively.

[0136] [Table 10]

[0137] [Table 11]

[0138] The dye (D) may consist of one type of compound, or may consist of two or more types of compounds. When it is composed of two or more compounds, each compound does not necessarily have to have the properties of dye (D), but the compound as a mixture needs to have the properties of dye (D).

[0139] Compounds (I) to (III) can be produced by known methods. Compound (I) Compound (I-11) can be produced by the method described in, for example, U.S. Patent No. 5,543,086. Compound (I-12) can be produced by the method described in, for example, U.S. Patent Application Publication No. 2014 / 0061505 and WO 2014 / 088063. Compound (II) can be produced by the method described in WO 2017 / 135359.

[0140] Specific examples of UV dyes include oxazole-based, merocyanine-based, cyanine-based, naphthalimide-based, oxadiazole-based, oxazine-based, oxazolidine-based, naphthalic acid-based, styryl-based, anthracene-based, cyclic carbonyl-based, and triazole-based dyes. Among these, oxazole-based or merocyanine-based dyes are preferred. The UV dyes may be used alone or in combination in the absorbing layer.

[0141] The transparent resin used is one that satisfies (i-1), (i-2) and (i-5) in relation to the dye (A).

[0142] The transparent resin may be at least one selected from, for example, acrylic resins, epoxy resins, ene-thiol resins, polycarbonate resins, polyether resins, polyarylate resins, polysulfone resins, polyethersulfone resins, polyparaphenylene resins, polyarylene ether phosphine oxide resins, polyimide resins, polyamideimide resins, polyolefin resins, cyclic olefin resins, and polyester resins, depending on the type of dye (A).

[0143] Among these, the transparent resin is preferably a polyester resin, a polycarbonate resin, a polyimide resin, or an acrylic imide resin. These resins may be used alone or in combination of two or more. When the dye (A) is the dye (A1) or the dye (A2), the transparent resin is preferably a polyester resin, a polycarbonate resin, a polyimide resin, or an acrylic imide resin.

[0144] As the transparent resin, commercially available products may be used. Examples of commercially available products include polyester resins such as OKP4HT, OKP4, B-OKP2, and OKP-850 (all of which are product names manufactured by Osaka Gas Chemicals Co., Ltd.), and Vylon (registered trademark) 103 (product name manufactured by Toyobo Co., Ltd.).

[0145] Examples of polycarbonate resins include LeXan (registered trademark) ML9103 (product name, manufactured by Sabic), EP5000 (product name, manufactured by Mitsubishi Gas Chemical Company, Inc.), SP3810 (product name, manufactured by Teijin Limited), SP1516 (product name, manufactured by Teijin Limited), TS2020 (product name, manufactured by Teijin Limited), and Xylex (registered trademark) 7507 (product name, manufactured by Sabic).

[0146] As the polyimide resin, Neoprim (registered trademark) C3650 (manufactured by Mitsubishi Gas Chemical Company, Inc.) Examples of polyimide resins include C3G30 (manufactured by Mitsubishi Gas Chemical Co., Ltd., product name), C3450 (manufactured by Mitsubishi Gas Chemical Co., Ltd., product name), JL-20 (manufactured by New Japan Chemical Co., Ltd., product name), FPC-0220 (manufactured by Mitsubishi Gas Chemical Co., Ltd., product name) (these polyimide resins may contain silica), etc. Examples of acrylic imide resins include PLEXIMID8817 (manufactured by Daicel-Evonik Ltd., product name), etc.

[0147] From the viewpoints of transparency, solubility of the dye (A) and further the dye (D), and heat resistance, the transparent resin is preferably a resin having a high glass transition point (Tg), for example, a Tg of 140° C. or higher.

[0148] The absorbing layer may further contain an adhesion imparting agent, a color tone correcting dye, or the like, within the range not impairing the effects of the present invention. Leveling agents, antistatic agents, heat stabilizers, light stabilizers, antioxidants, dispersants, flame retardants, lubricants, It may also contain optional ingredients such as plasticizers.

[0149] This filter has the characteristic (ii-1) because the absorption layer contains a dye (A) having the characteristics (i-1) to (i-5) and a transparent resin. In other words, the dye (A) is a compound that enables the optical filter obtained by using the dye to satisfy the characteristic (ii-1).

[0150] (ii-1) Average transmittance T of light in the wavelength range of 800 to 900 nm at an incident angle of 60 degrees 800-900ave60° The average transmittance T is less than 5%. 800-900ave60°is preferably 3% or less, and more preferably 1% or less.

[0151] In the present filter, when the absorbing layer contains dye (D) in addition to dye (A), dye (D) is preferably a compound that satisfies the following requirements (ii-2) to (ii-6) when used together with dye (A) to obtain an optical filter.

[0152] (ii-2) The optical filter has an average transmittance T of light in the wavelength range of 435 to 480 nm at an incident angle of 0 degrees. 435-480ave0° is more than 70%. (ii-3) The optical filter has an average transmittance T of light in the wavelength range of 490 to 580 nm at an incident angle of 0 degrees. 490-580ave0° is more than 84%. (ii-4) The optical filter has an average transmittance T of light in the wavelength range of 800 to 900 nm at an incident angle of 60 degrees. 800-900ave60° is less than 1%. (ii-5) The optical filter has a maximum transmittance T of light in the wavelength range of 800 to 900 nm at an incident angle of 60 degrees. 800-900max60° is less than 10%. (ii-6) The optical filter has a wavelength λ on the short wavelength side where the transmittance is 20% at an incident angle of 0 degrees. SHT20-0° is in the wavelength range of 640 to 690 nm, and the wavelength λ on the short wavelength side shows a transmittance of 20% at an incident angle of 30 degrees. SHT20-30° and wavelength λ SHT20-0° The difference is less than 10 nm.

[0153] (ii-2) Average transmittance T 435-480ave0° is preferably 75% or more, and more preferably 77% or more. 490-580ave0° The average transmittance T in (ii-4) is preferably 85% or more, and more preferably 87% or more. 800-900ave60° is preferably 0.9% or less, more preferably 0.5% or less. 800-900max60° is preferably 8.5% or less, and more preferably 5% or less. SHT20-30° and wavelength λ SHT20-0°The difference is preferably 5 nm or less, and more preferably 3 nm or less.

[0154] The content of the dye (A) in the absorbing layer is an amount that satisfies (ii-1) according to the design of the filter. The content of the dye (A) in the absorbing layer is preferably 0.1 to 20 parts by mass per 100 parts by mass of the transparent resin from the viewpoints of ensuring the transmittance of visible light, blocking near-infrared light, suppressing the incidence angle dependency of the reflective layer for light incident at a high angle, and particularly reducing light leakage in the wavelength range of 800 to 900 nm at a high incidence angle, and more preferably 1 to 20 parts by mass from the viewpoint of solubility.

[0155] When two or more kinds selected from dye S, dye M, and dye L are used as dye (A), the content of each dye is preferably 0.1 to 20 parts by mass, and more preferably 1 to 20 parts by mass, per 100 parts by mass of the transparent resin, with the total content of all dyes (A) being within the above range.

[0156] When the absorbing layer contains the dye (A) and the dye (D), their contents are appropriately selected so as to satisfy the characteristics (ii-2) to (ii-6) according to the design of the present filter.

[0157] In this case, the content of dye (A) in the absorbing layer is the same as above, and the content of dye (D) is preferably 0.1 to 20 parts by mass, and more preferably 1 to 20 parts by mass, per 100 parts by mass of the transparent resin, from the viewpoint of ensuring the transmittance of visible light while exhibiting the properties of dye (D). Furthermore, the total content of the dye (A) and the dye (D) is preferably from 0.1 to 20 parts by mass, and more preferably from 1 to 20 parts by mass, based on 100 parts by mass of the transparent resin.

[0158] In the present filter, the thickness of the absorbing layer is preferably 0.1 to 100 μm. When the absorbing layer is composed of a plurality of layers, the total thickness of the layers is preferably 0.1 to 100 μm. If the thickness is less than 0.1 μm, the desired optical properties may not be fully exhibited, and if the thickness is more than 100 μm, the flatness of the layer may decrease, and the in-plane variation of the absorptance may occur. The thickness of the absorbing layer is more preferably 0.3 to 50 μm. In addition, when other functional layers such as a reflective layer or an anti-reflective layer are provided, depending on the material, if the absorbing layer is too thick, cracks may occur. Therefore, the thickness of the absorbing layer is more preferably 0.3 to 10 μm.

[0159] The absorbing layer can be formed, for example, by dissolving or dispersing the dye (A), preferably the dye (A) and the dye (D), a transparent resin or a raw material component of the transparent resin, and each component that is mixed as necessary in a solvent to prepare a coating liquid, applying the coating liquid to a substrate, drying the coating liquid, and further curing the coating liquid as necessary. The substrate may be a transparent substrate included in the present filter, or a peelable substrate used only when forming the absorbing layer. The solvent may be a dispersion medium that can be stably dispersed or a solvent that can be dissolved.

[0160] The coating liquid may also contain a surfactant to improve voids caused by microbubbles, depressions caused by the adhesion of foreign matter, and repellency during the drying process. For example, a dip coating method, a cast coating method, or a spin coating method can be used to apply the coating liquid. After the coating liquid is applied onto the substrate, the coating liquid is dried to form an absorbing layer. When the coating liquid contains a raw material component of a transparent resin, a curing process such as heat curing or light curing is further performed.

[0161] The absorbing layer can also be manufactured in the form of a film by extrusion molding, and this film may be laminated to another member and integrated by thermocompression, etc. For example, when the present filter includes a transparent substrate, this film may be attached onto the transparent substrate.

[0162] The filter may have one or more absorption layers. When the filter has two or more layers, each layer may have the same or different configuration. For example, when the absorption layer contains a dye (A), a dye (D) and a UV dye, one layer may be a near-infrared absorption layer containing the dye (A) and the dye (D) and a transparent resin, and the other layer may be a near-ultraviolet absorption layer containing a UV dye and a transparent resin. As another example, one layer may be a first near-infrared absorption layer containing the dye (D) and a transparent resin, and the other layer may be a second near-infrared absorption layer containing the dye (A), a UV dye and a transparent resin. The absorption layer may also function as a substrate (resin substrate) by itself.

[0163] (Transparent substrate) When a transparent substrate is used in the present filter, the material of the transparent substrate is not particularly limited as long as it transmits visible light of about 400 to 700 nm, and may be a material that absorbs near-infrared light or near-ultraviolet light, for example, inorganic materials such as glass or crystal, or organic materials such as transparent resin.

[0164] Glass that can be used for transparent substrates includes absorption-type glass (near-infrared absorbing glass) that contains copper ions in fluorophosphate glass or phosphate glass, soda-lime glass, borosilicate glass, alkali-free glass, quartz glass, etc. Note that "phosphate glass" also includes silicophosphate glass, in which part of the glass skeleton is composed of SiO2.

[0165] The glass to be used may be chemically strengthened glass obtained by exchanging alkali metal ions having a small ionic radius (e.g., Li ions, Na ions) present on the main surface of the glass sheet with alkali ions having a larger ionic radius (e.g., Na ions or K ions for Li ions, and K ions for Na ions) through ion exchange at a temperature equal to or lower than the glass transition point.

[0166] Examples of transparent resin materials that can be used as the transparent substrate include polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyolefin resins such as polyethylene, polypropylene, and ethylene-vinyl acetate copolymers, norbornene resins, polyacrylates, Examples of the resin include acrylic resins such as polymethyl methacrylate, urethane resins, vinyl chloride resins, fluororesins, polycarbonate resins, polyvinyl butyral resins, polyvinyl alcohol resins, and polyimide resins.

[0167] In addition, examples of the crystal material that can be used for the transparent substrate include birefringent crystals such as quartz, lithium niobate, and sapphire. The optical characteristics of the transparent substrate should be the same as those of the optical filter obtained by laminating the absorbing layer, the reflective layer, and the like. Sapphire is preferable as the crystal material.

[0168] From the viewpoint of shape stability related to the long-term reliability of the optical properties and mechanical properties of the optical filter, and handling properties during filter production, the transparent substrate is preferably made of an inorganic material, and particularly preferably made of glass or sapphire.

[0169] The shape of the transparent substrate is not particularly limited and may be a block, plate, or film, and the thickness thereof is, for example, preferably 0.03 to 5 mm, more preferably 0.03 to 0.5 mm from the viewpoint of thinning. From the viewpoint of processability, a transparent substrate made of glass and having a thickness of 0.05 to 0.5 mm is preferred.

[0170] (reflective layer) The reflective layer is, for example, made of a dielectric multilayer film and has the function of blocking light in a specific wavelength range. Examples of the reflective layer include a layer that transmits visible light and has wavelength selectivity that mainly reflects light of wavelengths other than the light blocking range of the absorbing layer. The reflective layer preferably has a reflective region that reflects near-infrared light. In this case, the reflective region of the reflective layer may include a light blocking region in the near-infrared range of the absorbing layer. The reflective layer is not limited to the above characteristics and may be appropriately designed to further block light in a specific wavelength range, for example, the near-ultraviolet range.

[0171] When the reflective layer has a reflective region that reflects near-infrared light, it is preferable that the absorbing layer and the reflective layer have the following relationship.

[0172] The absorption layer is a layer that transmits light at a wavelength λ on the short wavelength side of the wavelength range where the transmittance is 20% for light with an incident angle of 0 degrees. ABSHT20-0° is preferably in the wavelength range of 650 to 720 nm. ABSHT20-0° is the wavelength λ on the short wavelength side at which an optical filter including a reflective layer exhibits a transmittance of 20% for light with an incident angle of 0 degrees in the reflective layer. RESHT20-0° It is preferable that the relationship satisfies (iv-1). (iv-1) ABSHT20-0° +30nm≦λ RESHT20-0° ≦790nm

[0173] It is preferable that the reflective layer further satisfies (iv-2). (iv-2) The reflective layer is λ RESHT20-0° From λ RESHT20-0° The average transmittance for light in the wavelength range up to +300 nm is 10% or less.

[0174] In this filter, since the absorption layer contains the dye (A), the incidence angle dependency of the reflective layer for light incident at a high angle can be suppressed, and in particular, light leakage in the wavelength range of 800 to 900 nm at high incidence angles can be reduced.

[0175] The reflective layer is composed of a dielectric multilayer film in which a dielectric film with a low refractive index (low refractive index film) and a dielectric film with a high refractive index (high refractive index film) are alternately laminated. The high refractive index film preferably has a refractive index of 1.6 or more, more preferably 2.2 to 2.5. Examples of materials for the high refractive index film include Ta2O5, TiO2, and Nb2O5. Among these, TiO2 is preferred from the viewpoints of film formation, reproducibility in refractive index, and stability.

[0176] On the other hand, the low refractive index film preferably has a refractive index of less than 1.6, more preferably 1.45 or more and less than 1.55. Examples of the material for the low refractive index film include SiO2, SiO x N yFrom the viewpoints of reproducibility, stability, economy, etc. in film formation, SiO2 is preferred.

[0177] Furthermore, it is preferable that the reflective layer has a steep change in transmittance in the boundary wavelength region between the transmission region and the light blocking region. For this purpose, the total number of laminated layers of the dielectric multilayer film constituting the reflective layer is preferably 15 layers or more, more preferably 25 layers or more, and even more preferably 30 layers or more. However, since warping or an increase in film thickness occurs when the total number of laminated layers is large, the total number of laminated layers is preferably 100 layers or less, more preferably 75 layers or less, and even more preferably 60 layers or less. Moreover, the film thickness of the dielectric multilayer film is preferably 2 to 10 μm.

[0178] If the total number of layers and the thickness of the dielectric multilayer film are within the above ranges, the reflective layer satisfies the requirement for miniaturization, and the incidence angle dependency can be suppressed while maintaining high productivity. In addition, the dielectric multilayer film can be formed by, for example, a vacuum film formation process such as a CVD method, a sputtering method, or a vacuum deposition method, or a wet film formation process such as a spray method or a dip method.

[0179] The reflective layer may be one layer (one group of dielectric multilayer films) that provides the desired optical characteristics, or two layers that provide the desired optical characteristics. When there are two or more layers, each reflective layer may have the same or different configurations. When there are two or more reflective layers, they are usually composed of multiple reflective layers with different reflection bands.

[0180] For example, when two reflective layers are provided, one may be a near-infrared reflective layer that blocks light in the short wavelength band of the near-infrared region, and the other may be a near-infrared / near-ultraviolet reflective layer that blocks light in both the long wavelength band of the near-infrared region and the near-ultraviolet region. Also, for example, when the present filter has a transparent substrate, when two or more reflective layers are provided, all of them may be provided on one main surface of the transparent substrate, or each reflective layer may be provided on both main surfaces of the transparent substrate sandwiched therebetween.

[0181] (Anti-reflection layer) Examples of the antireflection layer include a dielectric multilayer film, an intermediate refractive index medium, and a moth-eye structure in which the refractive index changes gradually. Among these, a dielectric multilayer film is preferred from the viewpoints of optical efficiency and productivity. The antireflection layer is obtained by alternately laminating dielectric films in the same manner as the reflective layer.

[0182] The filter may also include other components (layers) that absorb light using inorganic particles that control the transmission and absorption of light in a specific wavelength range. Specific examples of inorganic particles include ITO (Indium TIN Oxides), ATO (Antimony-doped TIN Oxides), cesium tungstate, lanthanum boride, etc. ITO particles and cesium tungstate particles have high transmittance of visible light and have light absorption properties over a wide range of infrared wavelengths exceeding 1200 nm, so they can be used when blocking infrared light is required.

[0183] The present filter has a reflective layer and an absorbing layer containing a dye (A), and thus can suppress the incidence angle dependency for light incident at a high angle. In particular, it can reduce light leakage in the wavelength range of 800 to 900 nm at high incidence angles, and has high transmittance for visible light.

[0184] The present filter satisfies the above condition (ii-1) when the absorbing layer contains the dye (A). When the absorbing layer further contains a dye (D), the present filter satisfies the above optical properties (ii-2) to (ii-6).

[0185] When the present filter is used in an imaging device such as a digital still camera, the imaging device can provide an imaging device with excellent color reproducibility. An imaging device using the present filter includes a solid-state imaging element, an imaging lens, and the present filter. The present filter can be used, for example, by being disposed between the imaging lens and the solid-state imaging element, or by being directly attached to the solid-state imaging element, imaging lens, etc. of the imaging device via an adhesive layer. EXAMPLES

[0186] Next, the present invention will be described more specifically with reference to examples.

[0187] [Test Examples 1 to 72: Preparation and Evaluation of Absorbing Layer] (dye) The dye (A) used in the examples is dye (A11-1B), dye (A12-1B), Dye (A12-2P), dye (A21-1B), dye (A22-1B), and dye (A22-1P) were synthesized by the method described in Dyes and pigments 73 (2007) 344-352. In addition, compound (I-12-24) was synthesized as dye (D) by a conventional method.

[0188] In addition, as dyes for comparative examples, FDN003 (manufactured by Yamada Chemical Co., Ltd., a phthalocyanine dye), ADS1065A (manufactured by American dye source, a diimonium dye), and ADS-920MC (manufactured by American dye source, a Ni dithiol complex dye) were prepared. In addition, the following squarylium dye (Scf) and cyanine dyes (Acf1) to (Acf7) were synthesized.

[0189] [ka]

[0190] [ka]

[0191] [ka]

[0192] Each of the above dyes was dissolved in dichloromethane and the optical absorption spectrum was measured at wavelengths of 400 to 1100 nm. max(A)DCM Furthermore, λ max(A)DCM The average transmittance T of light in the wavelength range of 435 to 480 nm when the transmittance is adjusted to 10%. 435-480ave(A)DCMand the average transmittance T for light in the wavelength range of 480 to 590 nm 480-590ave(A)DCM The optical properties of these dyes were evaluated using an ultraviolet-visible spectrophotometer (U-4100, Hitachi High-Technologies Corporation). The results are shown in Table 12. In the table, "T in DCM" means 435-480 ” is the average transmittance T 435-480ave(A)DCM "T in DCM" 480-590 ” is the average transmittance T 480-590ave(A)DCM Shows.

[0193] [Table 12]

[0194] As can be seen from Table 12, dyes other than cyanine dyes do not have sufficient transmittance for visible light in the spectral characteristics in dichloromethane solution.

[0195] (Preparation of the absorption layer) The cyanine dyes synthesized above and transparent resins were used to prepare absorbing layers, and the optical properties were evaluated. Test Examples 1 to 6, 14 to 19, 27 to 32, 39 to 44, and 51 to 53 are test examples related to the present filter, and Test Examples 7 to 13, 20 to 26, 33 to 38, 45 to 50, and 54 to 72 are comparative test examples. The following commercially available transparent resins were used.

[0196] <Transparent resin> Transparent resin (R1): OKP-850 (Osaka Gas Chemicals Co., Ltd., trade name, polyester resin) Transparent resin (R2); SP3810 (Teijin Limited, product name, polycarbonate resin) Transparent resin (R3); PLEXIMID8817 (Daicel Evonik, product name, acrylic imide resin) Transparent resin (R4): Neoprim (registered trademark) C3G30 (manufactured by Mitsubishi Gas Chemical Company, Inc., trade name, polyimide resin) Transparent resin (R5); FPC-0220 (product name, polyimide resin, manufactured by Mitsubishi Gas Chemical Company, Inc.) Comparative transparent resin (Rcf): BR96 (product name, acrylic resin, manufactured by Mitsubishi Rayon Co., Ltd.)

[0197] The dye, transparent resin (R1), and cyclohexanone were thoroughly stirred to dissolve uniformly. The resulting solution was applied to a glass plate (D263; manufactured by SCHOTT) and dried to obtain an absorbing layer having a thickness shown in Table 13. The amount of dye added was determined by the maximum absorption wavelength λ max(A)TR The spectral transmittance curve of the absorbing layer was obtained using the spectral transmittance curve of the glass plate with the absorbing layer and the spectral transmittance curve of the glass plate in the wavelength range of 400 to 1100 nm.

[0198] The average transmittance T of light in the wavelength range of 435 to 480 nm from the spectral transmittance curve 435-480ave(A)TR (In the table, "Resin medium T 435-480 ") and the average transmittance T for light in the wavelength range of 480 to 590 nm 480-590ave(A)TR (In the table, "Resin medium T 480-590 The average transmittance T 435-480ave(A)TR and average transmittance T 435-480ave(A)DCM The difference between the 435-480 "difference between and the average transmittance T 480-590ave(A)TR and average transmittance T 480-590ave(A)DCM The difference between the 480-590 The mass absorption coefficient / (cm·mass%) was calculated. The results are shown in Table 13. The dye concentrations in the table are the same as those in the above λ max (A)TR The parts by mass are based on 100 parts by mass of the transparent resin (R1) when the light transmittance is adjusted to 10% at 1000 nm.

[0199] [Table 13]

[0200] The same evaluation was carried out by replacing the transparent resin (R1) with the transparent resins (R2) to (R5) or the comparative transparent resin (Rcf). The results are shown in Table 14 for the transparent resin (R2), Table 15 for the transparent resin (R3), Table 16 for the transparent resin (R4), Table 17 for the transparent resin (R5), and Table 18 for the comparative transparent resin (Rcf).

[0201] [Table 14]

[0202] [Table 15]

[0203] [Table 16]

[0204] [Table 17]

[0205] [Table 18]

[0206] It is clear from Tables 13 to 18 that the requirements (i-1) to (i-5) are met by using a suitable transparent resin in combination with dye (A1) or dye (A2).

[0207] [Examples 1-6: Manufacturing and evaluation of optical filters] (Optical filter manufacturing) A reflective layer X made of a dielectric multilayer film was formed by alternately laminating TiO2 films and SiO2 films on a glass substrate (D263; manufactured by SCHOTT) having a thickness of 0.3 mm by a vapor deposition method. The relationship between the angle of incidence of the reflective layer X and the transmittance in each wavelength range is shown in Table 19. In addition, an absorbing layer was formed on the main surface of the glass substrate opposite to the main surface on which the reflective layer X was formed by combining a transparent resin, a dye (A), and a dye (D) shown in Table 20, thereby obtaining the optical filters (NIR filters) of Examples 1 to 6. The dye content in Table 20 is the part by mass of the dye relative to 100 parts by mass of the transparent resin.

[0208] In Table 19, T RE435-480aveis the average transmittance of light in the wavelength range of 435 to 480 nm, T RE490-580ave is the average transmittance for light in the wavelength range of 490 to 580 nm, T RE800-900ave is the average transmittance for light in the wavelength range of 800 to 900 nm, T RE800-900max is the maximum transmittance for light in the wavelength range of 800 to 900 nm, λ RESHT20 indicates the wavelength at which the transmittance becomes 20% on the short wavelength side of the reflection band.

[0209] [Table 19]

[0210] [Table 20]

[0211] (evaluation) The relationship between the incident angle and the transmittance in each wavelength range in the optical filters of Examples 1 to 6 obtained is shown in Tables 21 to 26, respectively. 435-480ave is the average transmittance of light in the wavelength range of 435 to 480 nm, T 490-580ave is the average transmittance for light in the wavelength range of 490 to 580 nm, T 800-900ave is the average transmittance for light in the wavelength range of 800 to 900 nm, T 800-900max is the maximum transmittance for light in the wavelength range of 800 to 900 nm, λ SHT20 indicates the wavelength at which the transmittance is 20% on the short wavelength side of the NIR blocking band.

[0212] [Table 21]

[0213] [Table 22]

[0214] [Table 23]

[0215] [Table 24]

[0216] [Table 25]

[0217] [Table 26]

[0218] From Tables 21 to 26, in Examples 1 to 6, λ at an incident angle of 0 degrees SHT20 and λ at an incidence angle of 30 degrees SHT20 It can be seen that the differences are all 1 nm or less. The optical filters of Examples 1 to 6 are optical filters that satisfy all of (ii-1) to (ii-6). [Industrial Applicability]

[0219] INDUSTRIAL APPLICABILITY The optical filter of the present invention has good visible light transmittance and good near-infrared shielding properties in which the decrease in the near-infrared shielding property at a high incident angle is suppressed, and is therefore useful for applications to imaging devices such as digital still cameras, the performance of which has been improving in recent years.

[0220] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention. This application is based on Japanese Patent Application No. 2018-018607 filed on February 5, 2018, the contents of which are incorporated herein by reference. [Explanation of symbols]

[0221] 10A, 10B, 10C, 10D, 10E, 10F...optical filters, 11, 11a, 11b...absorption layers, 12, 12a, 12b...reflective layers, 13...transparent substrate, 14...anti-reflection layer.

Claims

1. an absorbing layer containing a near-infrared absorbing dye and a transparent resin; A reflective layer; A substrate made of any one of phosphate glass, borosilicate glass, alkali-free glass, and transparent resin; The thickness of the absorbing layer is 0.3 to 10 μm, An optical filter that satisfies all of the following (1) to (5). (1) The average transmittance of light in the wavelength range of 435 to 480 nm at an incident angle of 0 degrees is 70% or more. (2) The average transmittance of light in the wavelength range of 490 to 580 nm at an incident angle of 0 degrees is 84% ​​or more. (3) The average transmittance of light in the wavelength range of 800 to 900 nm at an incident angle of 60 degrees is 0.1% or less. (4) The maximum transmittance of light in the wavelength range of 800 to 900 nm at an incident angle of 60 degrees is 2.1% or less. (5) Wavelength λ on the short wavelength side of the wavelength showing a transmittance of 20% at an incident angle of 0 degrees ＳＨＴ２０－０° is in the wavelength region of 640 to 690 nm, and the wavelength λ on the short wavelength side of the wavelength showing a transmittance of 20% at an incident angle of 30 degrees. ＳＨＴ２０－３０° and wavelength λ ＳＨＴ２０－０° The difference between them is 10 nm or less.

2. an absorbing layer containing at least two or more types of near-infrared absorbing dyes and UV dyes and a transparent resin; a reflective layer; The thickness of the absorbing layer is 0.3 to 10 μm, An optical filter that satisfies all of the following (1) to (5). (1) The average transmittance of light in the wavelength range of 435 to 480 nm at an incident angle of 0 degrees is 70% or more. (2) The average transmittance of light in the wavelength range of 490 to 580 nm at an incident angle of 0 degrees is 84% ​​or more. (3) The average transmittance of light in the wavelength range of 800 to 900 nm at an incident angle of 60 degrees is 0.1% or less. (4) The maximum transmittance of light in the wavelength range of 800 to 900 nm at an incident angle of 60 degrees is 2.1% or less. (5) Wavelength λ on the short wavelength side of the wavelength showing a transmittance of 20% at an incident angle of 0 degrees ＳＨＴ２０－０° is in the wavelength region of 640 to 690 nm, and the wavelength λ on the short wavelength side of the wavelength showing a transmittance of 20% at an incident angle of 30 degrees. ＳＨＴ２０－３０° and wavelength λ ＳＨＴ２０－０° The difference between them is 10 nm or less.

3. Two or more absorbent layers containing a transparent resin; a reflective layer; At least one of the absorbing layers has a thickness of 0.3 to 10 μm and contains a near-infrared absorbing dye; An optical filter that satisfies all of the following (1) to (5). (1) The average transmittance of light in the wavelength range of 435 to 480 nm at an incident angle of 0 degrees is 70% or more. (2) The average transmittance of light in the wavelength range of 490 to 580 nm at an incident angle of 0 degrees is 84% ​​or more. (3) The average transmittance of light in the wavelength range of 800 to 900 nm at an incident angle of 60 degrees is 0.1% or less. (4) The maximum transmittance of light in the wavelength range of 800 to 900 nm at an incident angle of 60 degrees is 2.1% or less. (5) Wavelength λ on the short wavelength side of the wavelength showing a transmittance of 20% at an incident angle of 0 degrees ＳＨＴ２０－０° is in the wavelength region of 640 to 690 nm, and the wavelength λ on the short wavelength side of the wavelength showing a transmittance of 20% at an incident angle of 30 degrees. ＳＨＴ２０－３０° and wavelength λ ＳＨＴ２０－０° The difference between them is 10 nm or less.

4. 2. The optical filter according to claim 1, wherein the absorption layer contains at least two types of near-infrared absorbing dyes.

5. 4. The optical filter according to claim 3, wherein at least one of the absorbing layers contains at least two types of near-infrared absorbing dyes.

6. 5. The optical filter of claim 1 or 4, wherein the absorbing layer contains a UV dye.

7. 6. The optical filter according to claim 3, wherein at least one of the absorbing layers contains a UV dye.

8. 4. The optical filter according to claim 2, further comprising a substrate made of any one of phosphate glass, borosilicate glass, alkali-free glass, and transparent resin.

9. 3. The optical filter of claim 1, further comprising another absorbing layer containing a transparent resin.

10. 10. The optical filter according to claim 1, wherein the reflective layer has a thickness of 2 to 10 μm.

11. The optical filter according to any one of claims 1 to 10, further comprising an anti-reflection layer.

12. 12. The optical filter according to claim 1, wherein the near-infrared absorbing dye comprises a dye having a maximum absorption wavelength in the wavelength region of 680 to 750 nm.

13. The optical filter according to any one of claims 1 to 12, further satisfying the following (9): (9) The maximum transmittance of light in the wavelength range of 800 to 900 nm at an incident angle of 60 degrees is 1.9% or less.

14. The optical filter according to any one of claims 1 to 13, further satisfying the following (10): (10) The maximum transmittance of light in the wavelength range of 800 to 900 nm at an incident angle of 60 degrees is 0.4% or less.

15. 15. The optical filter according to claim 1, wherein the near-infrared absorbing dye comprises a dye having a maximum absorption wavelength in a wavelength region of 760 to 900 nm.

16. The optical filter according to any one of claims 1 to 15, further satisfying the following (11): (11) The average transmittance of light in the wavelength range of 435 to 480 nm at an incident angle of 50 degrees is 60.6% or more.

17. The optical filter according to any one of claims 1 to 16, further satisfying the following (12): (12) The average transmittance of light in the wavelength range of 490 to 580 nm at an incident angle of 50 degrees is 77.6% or more.

18. An imaging device comprising the optical filter according to any one of claims 1 to 17.

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