Optical filter

Abstract

To provide an optical filter in which high transmittance of visible light, particularly transmittance of blue light, is favorably maintained, and also in which decrease in near-infrared light shielding performance at high incident angles, such as light leakage, is suppressed.SOLUTION: The present invention relates to an optical filter including a base material and a dielectric multilayer film laminated on at least one main surface of the base material. The base material includes a pigment (A) as a near-infrared absorption pigment and a resin film including resin. The pigment (A) includes at least one of the compound shown by the following formula (A1) and the compound shown by the following formula (A2). The optical filter satisfies a specific spectral characteristic.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. [Background technology]

[0002] In imaging devices using solid-state image sensors, optical filters are used that transmit visible light (hereinafter also referred to as "visible light") and block near-infrared wavelength light (hereinafter also referred to as "near-infrared light") in order to reproduce colors well and obtain sharp images.

[0003] Such optical filters can take various forms, such as reflective filters that alternately stack dielectric thin films with different refractive indices on one or both sides of a transparent substrate (dielectric multilayer film) and reflect the light to be blocked by utilizing light interference. Optical filters with dielectric multilayer films have problems such as changes in the spectral transmittance curve depending on the angle of incidence, light loss where near-infrared light, which should have high reflectivity at high angles of incidence, becomes highly transmittant, and noise is generated by near-infrared light reflected by the dielectric multilayer film, because the optical thickness of the dielectric multilayer film changes depending on the angle of incidence of light. When such filters are used, the spectral sensitivity of the solid-state image sensor may be affected by the angle of incidence. Therefore, there has been a need for an optical filter that blocks near-infrared light without significantly affecting the transmittance of visible light and without dependence on the angle of incidence.

[0004] Here, Patent Document 1 describes an optical filter that includes a layer containing a near-infrared absorbing dye to reduce the dependence on the angle of incidence. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] International Publication No. 2019 / 168090 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, the optical filter described in Patent Document 1 had room for improvement in terms of transmittance in the visible light region. Therefore, the present invention aims to provide an optical filter that maintains high transmittance of visible light, particularly blue light, while suppressing a decrease in near-infrared light shielding performance at high incidence angles, such as light leakage. [Means for solving the problem]

[0007] The present invention provides an optical filter having the following configuration. [1] An optical filter comprising a substrate and a dielectric multilayer film laminated as the outermost layer on at least one main surface side of the substrate, The substrate includes a resin film containing a dye (A), which is a near-infrared absorbing dye, and a resin. The dye (A) is an optical filter that satisfies all of the following spectral characteristics (i-1) to (i-4) in the spectral transmittance curve of a coating film obtained by dissolving the dye (A) in the resin and coating it on an alkali glass plate. (i-1) When the shortest wavelength at which the transmittance is 30% in the wavelength range of 600-800 nm is defined as IR30a, and the longest wavelength at which the transmittance is 30% in the wavelength range of 700-1200 nm is defined as IR30b, The absolute difference between IR30a and IR30b is 170 nm or more. (i-2) When the shortest wavelength at which the transmittance is 50% in the wavelength range of 600-800 nm is defined as IR50a, and the longest wavelength at which the transmittance is 50% in the wavelength range of 700-1200 nm is defined as IR50b, The absolute value of the difference between IR50a and IR50b is 200 nm or more. (i-3) Absorbance A at a wavelength of 440 nm 440 and absorbance A at a wavelength of 700 nm 700 The relationship is A 440 / A 700 ≤0.14 (i-4) Absorbance A at a wavelength of 490 nm 490 and absorbance A at a wavelength of 700 nm 700 The relationship is A 490 / A 700≤0.10 [Effects of the Invention]

[0008] According to the present invention, an optical filter can be provided that has high transmittance of visible light and high shielding of near-infrared light, and in particular, high transmittance of blue light and suppression of the decrease in shielding performance of near-infrared light at high incidence angles. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic cross-sectional view showing an example of an optical filter according to one embodiment. [Figure 2] Figure 2 is a schematic cross-sectional view showing another example of an optical filter according to one embodiment. [Figure 3] Figure 3 is a schematic cross-sectional view showing another example of an optical filter according to one embodiment. [Figure 4] Figure 4 is a schematic cross-sectional view showing another example of an optical filter according to one embodiment. [Figure 5] Figure 5 shows the spectral transmittance curves of compound 6 in dichloromethane and in cycloolefin resin. [Figure 6] Figure 6 shows the spectral transmittance curve of the optical filter in Example 3-1. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described below. In this specification, near-infrared absorbing dyes may be abbreviated as "NIR dyes," and ultraviolet absorbing dyes may be abbreviated as "UV dyes." In this specification, the compound represented by formula (I) is referred to as compound (I). The same applies to compounds represented by other formulas. A dye consisting of compound (I) is also referred to as dye (I), and the same applies to other dyes. Furthermore, the group represented by formula (I) is also referred to as group (I), and the same applies to groups represented by other formulas.

[0011] In this specification, internal transmittance is defined by the formula {measured transmittance / (100-reflectance)}×100, which is the transmittance obtained by subtracting the effect of interfacial reflection from the measured transmittance. In this specification, the spectral transmission of a substrate and the transmission of a resin film, including cases where the dye is contained in the resin, are all referred to as "internal transmission" even when the term "transmission" is used. On the other hand, the transmission measured by dissolving the dye in a solvent such as dichloromethane, and the transmission of an optical filter having a dielectric multilayer film, are measured transmissions.

[0012] In this specification, absorbance is calculated from (internal) transmittance using the formula -log10((internal) transmittance / 100).

[0013] In this specification, for a particular wavelength range, a transmittance of, for example, 90% or more means that the transmittance does not fall below 90% across the entire wavelength range, i.e., the minimum transmittance in that wavelength range is 90% or more. Similarly, for a particular wavelength range, a transmittance of, for example, 1% or less means that the transmittance does not exceed 1% across the entire wavelength range, i.e., the maximum transmittance in that wavelength range is 1% or less. The same applies to internal transmittance. The average transmittance and average internal transmittance in a particular wavelength range are the arithmetic mean of the transmittance and internal transmittance for every 1 nm in that wavelength range. In this specification, the symbol "~" used to indicate a numerical range includes both upper and lower limits.

[0014] <Optical filters> An optical filter according to one embodiment of the present invention (hereinafter also referred to as "this filter") comprises a substrate and a dielectric multilayer film laminated as the outermost layer on at least one main surface side of the substrate.

[0015] An example of the configuration of this filter will be explained using the drawings. Figures 1 to 4 are schematic cross-sectional views showing an example of an optical filter according to one embodiment. The optical filter 1A shown in Fig. 1 is an example having a dielectric multilayer film 30 on one main surface side of a substrate 10. Note that "having a specific layer on the main surface side of the substrate" includes not only the case where the layer is provided in contact with the main surface of the substrate, but also the case where another functional layer is provided between the substrate and the layer.

[0016] The optical filter 1B shown in Fig. 2 is an example having dielectric multilayer films 30 on both main surface sides of a substrate 10.

[0017] The optical filter 1C shown in Fig. 3 is an example in which the substrate 10 has a support 11 and a resin film 12 laminated on one main surface side of the support 11. The optical filter 1C further has dielectric multilayer films 30 on the resin film 12 and on the main surface side of the support 11 where the resin film 12 is not laminated.

[0018] The optical filter 1D shown in Fig. 4 is an example in which the substrate 10 has a support 11 and resin films 12 laminated on both main surface sides of the support 11. The optical filter 1D further has dielectric multilayer films 30 on each resin film 12.

[0019] <Substrate> In the optical filter of the present invention, the substrate contains a dye (A) and a resin. Preferably, the substrate includes a resin film containing a dye (A) and a resin.

[0020] <NIR dye (A)> The dye (A) is a near-infrared absorption (NIR) dye. By containing a dye that absorbs near infrared rays in the substrate, it is possible to suppress a decrease in spectral characteristics at a high incident angle of the dielectric multilayer film, for example, light leakage and noise generation in the near infrared region, due to the absorption characteristics of the substrate.

[0021] The dye (A) preferably has a maximum absorption wavelength in dichloromethane at 600 to 900 nm.

[0022] The pigment (A) exhibits specific spectral characteristics in the resin used for the base material. Specifically, the coating film obtained by dissolving the pigment (A) in the resin and coating it on an alkali glass plate satisfies all of the following spectral characteristics (i-1) to (i-4).

[0023] (i-1) When the shortest wavelength at which the transmittance becomes 30% at wavelengths of 600 to 800 nm is defined as IR30a, and the longest wavelength at which the transmittance becomes 30% at wavelengths of 700 to 1200 nm is defined as IR30b, the absolute value of the difference between IR30a and IR30b is 170 nm or more (i-2) When the shortest wavelength at which the transmittance becomes 50% at wavelengths of 600 to 800 nm is defined as IR50a, and the longest wavelength at which the transmittance becomes 50% at wavelengths of 700 to 1200 nm is defined as IR50b, the absolute value of the difference between IR50a and IR50b is 200 nm or more (i-3) The absorbance A at a wavelength of 440 nm 440 and the absorbance A at a wavelength of 700 nm 700 are related such that A 440 / A 700 ≦0.14 (i-4) The absorbance A at a wavelength of 490 nm 490 and the absorbance A at a wavelength of 700 nm 700 are related such that A 490 / A 700 ≦0.10

[0024] This filter containing the pigment (A) that exhibits the above spectral characteristics (i-1) to (i-4) in the resin is an optical filter that suppresses a decrease in the shielding property of near-infrared light at a high incident angle while maintaining good visible light transmittance, particularly blue light transmittance.

[0025] Satisfying spectral characteristics (i-1) and (i-2) means that near-infrared light can be absorbed broadly over a wide wavelength range. This efficiently prevents light leakage in the 750-900 nm wavelength band, where dielectric multilayer films are prone to light leakage due to inability to completely block light at high incident angles. Furthermore, because dye (A) itself has broad absorption characteristics in the resin, it is possible to efficiently block the near-infrared region with dye (A) alone while maintaining good transmittance in the visible light region, without combining multiple types of NIR dyes. While combining multiple types of NIR dyes can broadly block the near-infrared region, it tends to simultaneously reduce the transmittance in the visible light region. However, this can be avoided by using dye (A) in this invention.

[0026] The absolute value of the spectral characteristic (i-1) is preferably 190 nm or higher, more preferably 210 nm or higher, and particularly preferably 230 nm or higher. Furthermore, since a wider absorption width is preferable, there is no upper limit, but it is usually 270 nm or lower. The absolute value in the spectral characteristic (i-2) is preferably 210 nm or more, more preferably 230 nm or more. Furthermore, since a wider absorption width is preferable, there is no upper limit, but it is usually 270 nm or less.

[0027] Satisfying spectral characteristics (i-3) and (i-4) means that the material has excellent transmission properties for blue light. The spectral characteristic (i-3) is preferably A 440 / A 700 ≤ 0.11, and ferA 440 / A 700 The value is ≤ 0.10. The spectral characteristics (i-4) are preferably A 490 / A 700 ≤0.08, and ferA 490 / A 700 The value is ≤0.07.

[0028] It is preferable that the dye (A) further exhibits the following spectral characteristics (i-5) in the resin. That is, it is preferable that the above coating film containing the dye (A) and the resin satisfies the following spectral characteristics (i-5). (i-5) The product of the content of the pigment (A) in the coating film and the thickness of the coating film is 20 (mass %·μm) or less. By satisfying the spectral characteristics (i-5), the NIR dye (A) content is small enough to absorb near-infrared light over a wide wavelength range. The spectral characteristics (i-5) are preferably 15 (mass%·μm) or less, more preferably 12 (mass%·μm) or less, and also preferably 1 (mass%·μm) or more.

[0029] It is preferable that the dye (A) further exhibits the following spectral characteristics (i-6) in the resin. That is, it is preferable that the above coating film containing the dye (A) and the resin satisfies the following spectral characteristics (i-6). (i-6) A at a wavelength of 570 nm 570 and absorbance A at a wavelength of 700 nm 700 The relationship is A 570 / A 700 ≤0.10 Satisfying spectral characteristics (i-6) means that the material has excellent transmittance of green light. Spectral characteristics (i-6) are preferably A 570 / A 700 ≤0.05, and ferA 570 / A 700 The value is ≤0.03.

[0030] It is preferable that the dye (A) further exhibits the following spectral characteristics (i-7) in the resin. That is, it is preferable that the above coating film containing the dye (A) and the resin satisfies the following spectral characteristics (i-7). (i-7) Absorbance A at a wavelength of 630 nm 630 and absorbance A at a wavelength of 700 nm 700 The relationship is A 630 / A 700 ≤0.12 Satisfying spectral characteristics (i-7) means that the material has excellent transmittance of red light. Spectral characteristics (i-7) are preferably A 630 / A 700 ≤ 0.11, and ferA 630 / A 700 The value is ≤0.08.

[0031] It is preferable that the dye (A) further exhibits the following spectral characteristics (i-8) in the resin. That is, it is preferable that the above coating film containing the dye (A) and the resin satisfies the following spectral characteristics (i-8). (i-8) Average internal transmittance T in the spectral transmittance curve at wavelengths of 700-800 nm 700-800 2-25% Satisfying the spectral characteristics (i-8) means that high incidence light loss can be suppressed. The spectral characteristics (i-8) are preferably 2-20%, and more preferably 2-18%.

[0032] The dye (A) preferably further satisfies the following characteristics (ii-1) and (ii-2). In the spectral transmittance curve measured by dissolving the dye (A) in dichloromethane so that the transmittance at the maximum absorption wavelength is 10%, the shortest wavelength at which the transmittance is 30% in the wavelength range of 600-900 nm is defined as IR30a. (DIC) The longest wavelength at which the transmittance is 30% is defined as IR30b. (DIC) The shortest wavelength at which the transmittance is 50% is IR50a. (DIC) The longest wavelength at which the transmittance is 50% is defined as IR50b. (DIC) year, In the spectral transmittance curve of a coating film obtained by dissolving the dye (A) in the resin and coating it onto an alkali glass plate such that the transmittance at the maximum absorption wavelength is 10%, the shortest wavelength at which the transmittance is 30% in the wavelength range of 600 to 900 nm is IR30a. (PO) The longest wavelength at which the transmittance is 30% is defined as IR30b. (PO) The shortest wavelength at which the transmittance is 50% is IR50a. (PO) The longest wavelength at which the transmittance is 50% is defined as IR50b. (PO) In that case, (ii-1) IR30a (PO) and IR30b (PO) The absolute value of the difference between is IR30a (DIC) and IR30b (DIC) 2.8 times or more the absolute value of the difference between the two. (ii-2) IR50a (PO) and IR50b (PO) The absolute value of the difference between is IR50a(DIC) and IR50b (DIC) More than three times the absolute value of the difference between the two. By satisfying spectral characteristics (ii-1) and (ii-2), dye (A) exhibits a significantly wider absorption width in the resin than in dichloromethane in the near-infrared light absorption band of 600-900 nm. Here, the resin is the same as the resin contained in the substrate. The absolute value in the spectral characteristics (ii-1) is more preferably 3 times or more, and particularly preferably 4 times or more. The absolute value in the spectral characteristics (ii-2) is more preferably 3.2 times or more, and particularly preferably 4 times or more.

[0033] Cyanine dyes are preferred as the dye (A), and external salt type cyanine dyes having an anionic group outside the molecule are more preferred. External salt type cyanine dyes form an aggregate state in the resin and tend to broaden the near-infrared light absorption band, thus easily satisfying the above spectral characteristics (i-1) to (i-8), (ii-1), and (ii-2).

[0034] Specifically, the cyanine dye is preferably the compound shown in formula (A1) or the compound shown in formula (A2) below.

[0035] [ka]

[0036] However, the symbols in formulas (A1) and (A2) are as follows: R 101 ~R 109 and R 121 ~R 131 Each of these independently represents a hydrogen atom, a halogen atom, an alkyl or alkoxy group having 1 to 15 carbon atoms which may have substituents, or an aryl group having 5 to 20 carbon atoms. 110 ~ 114 and R 132 ~ 136 Each of these independently represents a hydrogen atom, a halogen atom, or an alkyl or alkoxy group having 1 to 15 carbon atoms. X - represents a monovalent anion. n1 and n2 are each independently 0 or 1. -(CH2) n1 A carbocyclic ring containing -, and a hydrogen atom bonded to a carbocyclic ring containing -(CH2) n2 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.

[0037] 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 group or an 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 high visible light transmittance.

[0038] 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 high visible light transmittance.

[0039] R 106 [[ID=e46]]、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), and more preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms. Also, R 106 and R 107 、R 128 and R 129 are preferably the same group.

[0040] R 101 and R 121is preferably an alkyl group having 1 to 15 carbon atoms or an aryl group having 5 to 20 carbon atoms, and more preferably an alkyl group having 1 to 15 carbon atoms and having a branch from the viewpoint of maintaining a high visible light transmittance in the transparent resin as in the solution.

[0041] X - Examples of [it] include I - , BF4 - , PF6 - , ClO4 - , or an anion represented by the formula (X1) or (X2), etc. Preferably, BF4 - , or PF6 - .

[0042]

Chemical formula

[0043] In the following description, the part excluding R 101 ~R 114 in the dye (A1) is also referred to as the skeleton (A1). The same applies to other dyes.

[0044] In the formula (A1), the compound in which n1 is 1 is shown by the following formula (A11), and the compound in which n1 is 0 is shown by the following formula (A12).

[0045]

Chemical formula

[0046] In the formula (A11) and the formula (A12), R 101 ~R 114 and X - are the same as in the case of the formula (A1). R 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 an aryl group having 5 to 20 carbon atoms. R 115 ~R 120Each of these is 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 linear, cyclic, or branched alkyl groups), and more preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms. 115 ~R 120 It is preferable that they be the same group.

[0047] In equation (A2), compounds with n2 = 1 are shown in equation (A21), and compounds with n2 = 0 are shown in equation (A22).

[0048] [ka]

[0049] In equations (A21) and (A22), R 121 ~R 136 and X - This is the same as in the case of equation (A2). 137 ~R 142 Each of these independently represents a hydrogen atom, a halogen atom, an alkyl or alkoxy group having 1 to 15 carbon atoms which may have substituents, or an aryl group having 5 to 20 carbon atoms. 137 ~R 142 Each of these is 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 linear, cyclic, or branched alkyl groups), and more preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms. 137 ~R 142 It is preferable that they be the same group.

[0050] More specifically, the compounds represented by formulas (A11), (A12), (A21), and (A22) are compounds in which the atoms or groups bonded to each skeleton are those shown in Tables 1 to 4 below. In all the compounds shown in Tables 1 and 2, R 101 ~R 109 The left and right sides of the equation are all identical. In all the compounds shown in Tables 3 and 4, R 121 ~R 131The terms on both sides of the equation are identical.

[0051] R in Table 1 102 -R 105 , R 110 -R 114 , R 115 -R 120 R in Table 2 102 -R 105 , R 110 -R 114 , R 115 -R 118 R in Table 3 122 -R 127 , R 132 -R 136 , R 137 -R 143 R in Table 4 122 -R 127 , R 132 -R 136 , R 137 -R 140 In cases where all atoms are hydrogen atoms, it is written as "H".

[0052] [Table 1]

[0053] From the viewpoint of synthesis, solubility in resin, heat resistance, and light resistance, (A11-1) to (A11-4), (A11-9) to (A11-12), and (A11-17) to (A11-20) are preferred as the pigment (A11).

[0054] [Table 2]

[0055] From the viewpoint of synthesis, solubility in resin, heat resistance, and light resistance, (A12-1) to (A12-4), (A12-9) to (A12-12), and (A12-17) to (A12-20) are preferred as the pigment (A12).

[0056] [Table 3]

[0057] As the pigment (A21), (A21-1) to (A21-4), (A21-9) to (A21-12), and (A21-17) to (A21-20) are preferable from the viewpoints of synthesis, solubility in the resin, heat resistance, and light resistance.

[0058] [Table 4]

[0059] As the pigment (A22), (A22-1) to (A22-4), (A22-9) to (A22-12), and (A22-17) to (A22-20) are preferable from the viewpoints of synthesis, solubility in the resin, heat resistance, and light resistance. Particularly, (A22-17) to (A22-20) are preferable from the viewpoints of broadness and the ability to shield a wide band of 700 to 850 nm in terms of the maximum absorption wavelength and the ability to maintain a high visible transmittance.

[0060] Note that the pigments (A1) and (A2) can be produced, for example, by the methods described in Dyes and pigments 73(2007) 344-352 and J.Heterocyclic chem,42,959(2005).

[0061] The resin film may contain one kind of the pigment (A1) and the pigment (A2) alone, or may contain a combination of two or more kinds.

[0062] From the viewpoint of satisfying the desired spectral characteristics without degrading the resin properties, the content of the pigment (A) in the resin film is preferably 2 to 25 parts by mass, more preferably 2 to 20 parts by mass, per 100 parts by mass of the resin.

[0063] <NIR pigment (B)> In the base material of the optical film of the present invention, as the NIR pigment, in addition to the pigment (A), a pigment (B) having a maximum absorption wavelength in dichloromethane of 600 to 900 nm may be further contained. Thereby, near-infrared light can be blocked more efficiently.

[0064] As the dye (B), at least one selected from the group consisting of squarylium dye, phthalocyanine dye, naphthalocyanine dye, dithiol metal complex dye, azo dye, polymethine dye, phthalide dye, naphthoquinone dye, anthraquinone dye, indophenol dye, pyrylium dye, thiopyrillium dye, chloroconium dye, tetradehydocholine dye, triphenylmethane dye, aminium dye, and diimmonium dye is preferred.

[0065] The pigment (B) preferably contains at least one pigment selected from squarylium pigment, phthalocyanine pigment, and diimmonium pigment.

[0066] As the squarylium dye, the compound shown in the following formula (I) is preferred.

[0067] [ka]

[0068] However, the symbols in equation (I) are as follows: R 24 and R 26 Each of these independently consists of a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl or alkoxy group having 1 to 6 carbon atoms, an acyloxy group having 1 to 10 carbon atoms, and -NR. 27 R 28 (R 27 and R 28 These are, independently, a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, and -C(=O)-R 29 (R 29 (This includes a hydrogen atom, a C1-C20 alkyl group or C6-C11 aryl group which may have substituents, or a C7-C18 aryl group which may have substituents and may have oxygen atoms between carbon atoms), -NHR 30 , or -SO2-R 30 (R 30(R) represents a hydrocarbon group having 1 to 25 carbon atoms, in which each hydrogen atom may be substituted with a halogen atom, hydroxyl group, carboxyl group, sulfo group, or cyano group, and which may contain unsaturated bonds, oxygen atoms, or saturated or unsaturated ring structures between carbon atoms. ) or a group represented by the following formula (S) (R) 41 , R 42 k 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.

[0069] [ka]

[0070] R 21 and R 22 , R 22 and R 25 , and R 21 and R 23 These may be linked together to form heterocycles A, B, and C, respectively, with nitrogen atoms, each having a membership of 5 or 6.

[0071] R when a heteroalgebra A is formed 21 and R 22 This represents an alkylene group or alkylene oxy 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 that may have substituents, as the divalent group -Q- to which these are bonded.

[0072] R when a heteroalgebra B is formed 22 and R 25 , and R when a heterocyclic ring C is formed 21 and R 23 These are the divalent groups -X to which they are bonded. 1 -Y 1 -and -X 2 -Y 2 -(The side that bonds to nitrogen is X) 1 and X 2 ) as X 1 and X 2These are the groups represented by the following formulas (1x) or (2x), and Y 1 and Y 2 Each of these is a group represented by one of the following formulas (1y) to (5y). 1 and X 2 However, in the case of the base represented by the following formula (2x), Y 1 and Y 2 Each of these may be a single bond, in which case there may be an oxygen atom between the carbon atoms.

[0073] [ka]

[0074] In formula (1x), the four Zs are each independently a hydrogen atom, a hydroxyl group, an alkyl or alkoxy group having 1 to 6 carbon atoms, or -NR 38 R 39 (R 38 and R 39 Each of these independently represents either a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. 31 ~R 36 Each independently comprises a hydrogen atom, a C1-C6 alkyl group, or a C6-C10 aryl group, R 37 This represents an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms.

[0075] R 27 , R 28 , R 29 , R 31 ~R 37 , R when it does not form a heteroalgebra 21 ~R 23 , and R 25 These may bond with any of the others to form a five-membered ring or a six-membered ring. 31 and R 36 , R 31 and R 37 They may be directly joined.

[0076] When R does not form a heteroalgebra, 21 and R 22Each of these independently represents a hydrogen atom, an alkyl or allyl group having 1 to 6 carbon atoms which may have substituents, or an aryl or alaryl group having 6 to 11 carbon atoms which may have substituents. When a heterocycle is not formed, R 23 and R 25 Each of these independently represents a hydrogen atom, a halogen atom, or an alkyl or alkoxy group having 1 to 6 carbon atoms.

[0077] As for compound (I), for example, a compound represented by formula (I-1) is preferred from the viewpoint of being able to increase the visible light transmittance.

[0078] [ka]

[0079] The symbols in formula (I-1) are the same as those specified for the same symbols in formula (I), and the preferred embodiments are also the same.

[0080] In compound (I-1), X 1 As for the base, (2x) is preferred, Y 1 A single bond or group (1y) is preferred. In this case, R 31 ~R 36 Preferably, it is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom or a methyl group. 1 -X 1 Specifically, examples include the divalent organic groups shown in formulas (11-1) to (12-3).

[0081] -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)

[0082] Furthermore, in compound (I-1), R 21 From the viewpoint of solubility, heat resistance, and the steepness of the change near the boundary between the visible and near-infrared regions in the spectral transmittance curve, the group represented by formula (4-1) or formula (4-2) is independently more preferred.

[0083] [ka]

[0084] In equations (4-1) and (4-2), R 71 ~R 75 This independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms.

[0085] Compound (I) can be produced by known methods, for example, U.S. Patent No. 5,543,086, U.S. Patent Application Publication No. 2014 / 0061505, and International Publication No. 2014 / 088063.

[0086] Examples of phthalocyanine dyes include the phthalocyanine dyes described in Japanese Patent No. 5884953 and International Publication No. 2019 / 168090.

[0087] Examples of diinmonium dyes include the diinmonium dye described in International Publication No. 2014 / 168189.

[0088] The resin film may contain one type of pigment (B) alone, or it may contain two or more types in combination.

[0089] The content of dye (B) in the resin film is preferably 2 to 25 parts by mass, more preferably 2 to 20 parts by mass, per 100 parts by mass of resin.

[0090] <Other pigments> The substrate may contain other dyes besides NIR dyes, such as UV dyes. UV dyes include, specifically, oxazole, merocyanine, cyanine, naphthalimide, oxadiazole, oxazine, oxazolidine, naphthalic acid, styryl, anthracene, cyclic carbonyl, and triazole dyes. UV dyes may be used individually or in combination of two or more.

[0091] <Base material composition> The substrate in this filter may have a single-layer or multi-layer structure. Furthermore, the material of the substrate is not particularly limited; it may be an organic or inorganic material as long as it is a transparent material that transmits visible light in the 400-700 nm range. When the substrate has a single-layer structure, a resin substrate consisting of a resin and a resin film containing an NIR dye (A) is preferred. When the substrate has a multilayer structure, a composite substrate is preferred in which a resin film containing NIR dye (A) is laminated on at least one main surface of the support. In this case, the support is preferably made of a transparent resin or a transparent inorganic material.

[0092] The resin in the resin layer is preferably a transparent resin. As the transparent resin, a polymer composed of alicyclic compounds is preferred from the viewpoint that the NIR dye (A) forms an aggregate state and the near-infrared light absorption band is easily broadened. Examples of such polymers include cyclic alkane resins and cyclic olefin resins, and these resins may be used individually or in mixtures of two or more.

[0093] If the substrate contains NIR dye (B) or other dyes, these dyes may be included in a resin film containing NIR dye (A), or they may be included in another resin film. When laminating another resin film, one or more transparent resins selected from polyester resin, acrylic resin, epoxy resin, ene-thiol resin, polycarbonate resin, polyether resin, polyarylate resin, polysulfone resin, polyethersulfone resin, polyparaphenylene resin, polyarylene ether phosphine oxide resin, polyamide resin, polyimide resin, polyamide-imide resin, polyolefin resin, cyclic olefin resin, polyurethane resin, and polystyrene resin are used as the transparent resin.

[0094] Glass and crystalline materials are preferred as transparent inorganic materials. Examples of glass that can be used as a support include boiling phosphate glass, phosphate glass, and other absorption-type glass containing copper ions (near-infrared absorbing glass), soda-lime glass, borosilicate glass, alkali-free glass, and quartz glass. Depending on the purpose, absorption glass is preferred, and from the viewpoint of absorbing infrared light, phosphate glass and boiling phosphate glass are preferred. When it is desired to capture a large amount of red light (600-700 nm), alkali glass, alkali-free glass, and quartz glass are preferred. Note that "phosphate glass" also includes silicate glass in which part of the glass skeleton is composed of SiO2.

[0095] As the glass, chemically strengthened glass may be used, obtained by ion exchange at a temperature below the glass transition temperature, in which alkali metal ions with small ionic radii (e.g., Li ions, Na ions) present on the main surface of the glass plate are replaced with alkali ions with larger ionic radii (e.g., Na ions or K ions for Li ions, and K ions for Na ions).

[0096] Examples of crystalline materials that can be used as supports include birefringent crystals such as quartz, lithium niobate, and sapphire.

[0097] As a support material, inorganic materials are preferred, particularly glass and sapphire, from the viewpoint of shape stability related to long-term reliability such as spectral characteristics and mechanical properties, as well as handling ease during filter manufacturing.

[0098] The resin film can be formed by preparing a coating solution by dissolving or dispersing a dye (A), a resin or resin raw material component, and other components as needed in a solvent, coating this solution onto a support, drying it, and further curing it as needed. The support may be the support included in this filter, or it may be a releaseable support used only when forming the resin film. The solvent may be any dispersion medium or solvent that can stably disperse or dissolve the components.

[0099] Furthermore, the coating solution may contain a surfactant to improve voids caused by minute bubbles, indentations caused by the adhesion of foreign matter, and repulsion during the drying process. In addition, methods such as immersion coating, cast coating, or spin coating can be used for applying the coating solution. After applying the above coating solution to the support, a resin film is formed by drying. Furthermore, if the coating solution contains raw material components of a transparent resin, a curing treatment such as thermosetting or photocuring is performed.

[0100] Furthermore, the resin film can also be manufactured in film form by extrusion molding. When the substrate is a single-layer structure (resin substrate) consisting of a resin film containing the dye (A), the resin film can be used as the substrate as is. When the substrate is a multi-layer structure (composite substrate) having a support and a resin film containing the dye (A) laminated on at least one main surface of the support, the substrate can be manufactured by laminating this film onto the support and integrating it by heat pressing or the like.

[0101] The resin film may be present as one layer within the optical filter, or as two or more layers. If there are two or more layers, each layer may have the same or different configuration.

[0102] When the substrate is a multilayer structure (composite substrate) having a support and a resin film containing a dye (A) and resin, the thickness of the resin film is preferably 5 μm or less, more preferably 3 μm or less. Furthermore, the thickness of the resin film is preferably 0.5 μm or more. When the resin film consists of multiple layers, the total thickness of each layer is preferably 0.5 to 10 μm. Furthermore, if the substrate is a single-layer structure (resin substrate) consisting of a resin film containing the dye (A), the thickness of the resin film is preferably 50 to 300 μm. The optical filter of the present invention contains an NIR dye (A) that satisfies specific spectral characteristics, enabling efficient shielding of near-infrared light over a wide range even with a low dye content. Therefore, the resin film containing dye (A) can be made into a thin film.

[0103] The shape of the substrate is not particularly limited and may be in the form of a block, plate, or film. Furthermore, the thickness of the substrate is preferably 300 μm or less from the viewpoint of reducing warping during dielectric multilayer film formation and reducing the height of the optical filter. If the substrate is a resin substrate consisting of a resin film, it is preferably 50 to 300 μm, and if the substrate is a composite substrate comprising a support and a resin film, it is preferably 100 to 300 μm.

[0104] <Dielectric multilayer film> In this filter, the dielectric multilayer film is laminated as the outermost layer on at least one main surface side of the substrate.

[0105] In this filter, it is preferable that at least one of the dielectric multilayer films is designed as a near-infrared reflective layer (hereinafter also referred to as the NIR reflective layer). The other dielectric multilayer film is preferably designed as an NIR reflective layer, a reflective layer having a reflection region other than the near-infrared region, or an anti-reflective layer.

[0106] The NIR reflective layer is a dielectric multilayer film designed to block near-infrared light. For example, the NIR reflective layer has wavelength selectivity, transmitting visible light and primarily reflecting near-infrared light outside the light-blocking region of the resin film. The reflective region of the NIR reflective layer may also include the light-blocking region of the resin film in the near-infrared region. The NIR reflective layer may be designed to further block light in wavelengths other than the near-infrared region, such as the near-ultraviolet region, as appropriate.

[0107] The NIR reflective layer is composed of a dielectric multilayer film in which a low refractive index dielectric film (low refractive index film) and a high refractive index dielectric film (high refractive index film) are alternately stacked. The high refractive index film preferably has a refractive index of 1.6 or higher, and more preferably 2.2 to 2.5. Examples of materials for the high refractive index film include Ta2O5, TiO2, and Nb2O5. Of these, TiO2 is preferred in terms of film formation properties, reproducibility in refractive index, stability, etc.

[0108] On the other hand, the low refractive index film preferably has a refractive index of less than 1.6, and more preferably 1.45 or more and less than 1.55. Examples of materials for the low refractive index film are SiO2, SiO2, and SiO2. x N y These are some examples. SiO2 is preferred in terms of reproducibility, stability, and cost-effectiveness in film formation.

[0109] Furthermore, it is preferable that the transmittance of the NIR reflective layer changes abruptly in the boundary wavelength region between the transmittance and shielding regions. For this purpose, the total number of layers of dielectric multilayer films constituting the reflective layer is preferably 15 or more, more preferably 25 or more, and even more preferably 30 or more. However, as the total number of layers increases, warping and other issues may occur, and the film thickness may increase, so the total number of layers is preferably 100 or less, more preferably 75 or less, and even more preferably 60 or less. In addition, the film thickness of the reflective layer is preferably 2 to 10 μm overall.

[0110] If the total number of layers and thickness of the dielectric multilayer film are within the above range, the NIR reflective layer can meet the miniaturization requirements and suppress incident angle dependence while maintaining high productivity. Furthermore, for the formation of the dielectric multilayer film, vacuum deposition processes such as CVD, sputtering, and vacuum evaporation, as well as wet deposition processes such as spraying and dipping, can be used.

[0111] The NIR reflective layer may provide predetermined spectral characteristics with a single layer (a group of dielectric multilayer films) or with two layers. If there are two or more layers, each reflective layer may have the same or different configuration. When there are two or more reflective layers, they are usually composed of multiple reflective layers with different reflection bands. 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.

[0112] Examples of anti-reflective layers include dielectric multilayer films, intermediate refractive index media, and moth-eye structures with gradually changing refractive indices. Among these, dielectric multilayer films are preferred from the viewpoint of optical efficiency and productivity. The anti-reflective layer is obtained by alternately stacking dielectric films, similar to the reflective layer.

[0113] <Optical filters> The optical filter of the present invention preferably satisfies all of the following spectral characteristics (iii-1) to (iii-7) by having the above configuration. (iii-1) Average transmittance T in the spectral transmittance curve at wavelengths of 440-490 nm and an incident angle of 0 degrees. 440-490(0deg)AVE over 85% (iii-2) Average transmittance T in the spectral transmittance curve at wavelengths of 440-490 nm and an incident angle of 30 degrees 440-490(30deg)AVE over 85% (iii-3) Average transmittance T in the spectral transmittance curve at wavelengths of 500-570 nm and an incident angle of 0 degrees 500-570(0deg)AVE over 90% (iii-4) Average transmittance T in the spectral transmittance curve at wavelengths of 500-570 nm and an incident angle of 30 degrees 500-570(30deg)AVE over 90% (iii-5) Maximum transmittance T in the spectral transmittance curve at wavelengths of 700-850 nm and an incident angle of 0 degrees. 700-850(0deg)MAX less than 3% (iii-6) Maximum transmittance T in the spectral transmittance curve at wavelengths of 700-850 nm and an incident angle of 30 degrees. 700-850(30deg)MAX less than 1% (iii-7) Maximum transmittance T in the spectral transmittance curve at wavelengths of 700-850 nm and an incident angle of 60 degrees. 700-850(60deg)MAX less than 1%

[0114] By satisfying spectral characteristics (iii-1) to (iii-4), an optical filter with excellent transmittance in the visible light region, especially blue light, can be obtained even with light at high incident angles. The spectral characteristics (iii-1) and (iii-2) are preferably 86% or higher. The spectral characteristics (iii-3) and (iii-4) are preferably 92% or higher.

[0115] By satisfying spectral characteristics (iii-5) to (iii-7), an optical filter can be obtained that does not lose light even with high incident angles and has high shielding performance for near-infrared light. The spectral characteristics (iii-5) are preferably 2% or less. The spectral characteristics (iii-6) are preferably 0.7% or less. The spectral characteristics (iii-7) are preferably 0.8% or less.

[0116] This filter may also include other components, such as a component (layer) that provides absorption by inorganic nanoparticles that control the transmission and absorption of light in a specific wavelength range. Specific examples of inorganic nanoparticles include ITO (Indium Tin Oxides), ATO (Antimony-doped Tin Oxides), cesium tungstate, and lanthanum boride. ITO nanoparticles and cesium tungstate nanoparticles have high transmittance of visible light and light absorption over a wide range in the infrared wavelength region exceeding 1200 nm, and can therefore be used when shielding against such infrared light is required.

[0117] This filter, when used in imaging devices such as digital still cameras, can provide an imaging device with excellent color reproduction. An imaging device using this filter comprises a solid-state image sensor, an imaging lens, and this filter. This filter can be used, for example, by being placed between the imaging lens and the solid-state image sensor, or by being directly attached to the solid-state image sensor, imaging lens, etc. of the imaging device via an adhesive layer. [Examples]

[0118] Next, the present invention will be described in more detail with reference to examples. A UV-Vis spectrophotometer (Hitachi High-Technologies Corporation, UH-4150 model) was used to measure each spectral characteristic. Unless otherwise specified, the spectral characteristics are measured at an incident angle of 0 degrees (perpendicular to the optical filter).

[0119] The dyes used in each example are as follows: Compounds 1-9 (cyanine compounds): Synthesized using the synthesis method described in Dyes and Pigments 73 (2007), pp. 344-352. Compound 10 (squallium compound): Synthesized based on International Publication No. 2014 / 088063. Compound 11 (squallium compound): Synthesized with reference to Japanese Patent Publication No. 2017-110209.

[0120] [ka]

[0121] [ka]

[0122] [ka]

[0123] [ka]

[0124] <Example 1-1: Spectral properties of NIR dyes in resin> NIR dye compound 1 (7.5% by mass) was mixed with polyimide resin (C-3G30G, manufactured by Mitsubishi Gas Chemical Co., Ltd.) diluted with an organic solvent (cyclohexanone), and the polyimide solution and dye were thoroughly dissolved. The obtained dye solution was applied to a glass substrate (alkali glass, Shotto D263) using spin coating, and the organic solvent was removed by heating to create a 1 μm thick dye-containing resin thin film (coated film). For the obtained thin film, transmission spectroscopy was measured in the incident direction at 0 degrees and reflection spectroscopy in the incident direction at 5 degrees, within the wavelength range of 350 nm to 1200 nm. The transmittance is expressed as the internal transmittance, which is shown by the following formula. Internal transmittance (%) = {Measured transmittance} (0deg) / (100-reflectance (5deg) )} × 100 Furthermore, the absorbance is shown as a value converted from the internal transmittance using the following formula. Absorbance = -log10 (internal transmittance / 100)

[0125] <Examples 1-2 to 1-18> A dye-containing resin thin film was prepared in the same manner as in Example 1-1, except that NIR dyes shown in the table below were used in the amounts shown in the table below instead of NIR dye compound 1, one of the resins shown below was used instead of polyimide resin, and the thickness of the thin film was set to the value shown in the table below. Transmission spectroscopy was then measured. Polyester resin: Manufactured by Osaka Gas Chemical Co., Ltd. Cycloolefin resin: ARTON F4520 manufactured by JSR Corporation The results are shown in the table below.

[0126] Examples 1-10 to 1-14 are examples, while Examples 1-1 to 1-9 and 1-15 to 1-18 are comparative examples.

[0127] IR50 width (nm): The absolute value of the difference between IR50a and IR50b. IR30 width (nm): The absolute value of the difference between IR30a and IR30b.

[0128] [Table 5]

[0129] The results from Examples 1-10 to 1-14 show that the external salt-type cyanine dyes exhibited broad absorption characteristics for near-infrared light while maintaining high transmittance of blue light in alicyclic compound polymers.

[0130] <Comparison of resin spectroscopy and solution spectroscopy> <Examples 2-1 to 2-7: Solution Spectroscopy> The NIR dyes shown in the table below were dissolved in dichloromethane, and solution spectroscopy was measured at wavelengths from 350 nm to 1200 nm. The spectral characteristics calculated so that the transmittance at the maximum absorption wavelength was 10% are shown in the table below.

[0131] <Examples 2-8 to 2-14: Resin Spectroscopy> The spectral characteristics of the thin films manufactured in Examples 1-10 to 1-16, calculated from transmission and reflection spectroscopy so that the transmittance at the maximum absorption wavelength is 10%, are shown in the table below.

[0132] We compared the IR50 width and IR30 width for solution spectroscopy and resin spectroscopy using the same NIR dye. Furthermore, Figure 5 shows the solution spectroscopy results for compound 6 from Example 2-4 and the resin spectroscopy results from Example 2-11. The solid line represents the resin spectroscopy, and the dashed line represents the solution spectroscopy.

[0133] IR30 width (DIC) (nm): IR30a (DIC) and IR30b (DIC) The absolute value of the difference between IR30 width (PO) (nm): IR30a (PO) and IR30b (PO) The absolute value of the difference between IR50 width (DIC) (nm): IR50a (DIC) and IR50b (DIC) The absolute value of the difference between IR50 width (PO) (nm): IR50a (PO) and IR50b (PO) The absolute value of the difference between IR30 width (against dichloromethane): IR30 width (DIC) IR30 width (PO) ratio IR50 width (against dichloromethane): IR50 width (DIC) IR50 width (PO) ratio

[0134] Examples 2-1 to 2-7 are for reference only, examples 2-8 to 2-12 are examples of actual cases, and examples 2-13 to 2-14 are comparative examples.

[0135] [Table 6]

[0136] [Table 7]

[0137] Based on the results above, in Examples 2-8 to 2-12, where an external salt type cyanine dye was used as the NIR dye, the widths of IR30 and IR50 were significantly broadened in the resin compared to the solution. In other words, the absorption spectroscopy was broadened in the resin.

[0138] <Example 3-1: Spectral characteristics of an optical filter> Compound 11, an NIR dye, was added to polyimide resin (C-3G30G, manufactured by Mitsubishi Gas Chemical Co., Ltd.) at a concentration of 5.25% by mass relative to the resin, and then cyclohexanone was added as a solvent to ensure complete dissolution (dye solution 1). Compound 6, an NIR dye, was added at a concentration of 2% by mass relative to the cycloolefin resin (ARTON resin F4520, manufactured by JSR Corporation). Cyclohexanone was then added as a solvent and the mixture was thoroughly dissolved (dye solution 2). An ultraviolet and infrared cut multilayer film having a transmission band from 400 nm to 700 nm was deposited on a glass substrate (alkali glass, D263 manufactured by Schott). A dye solution 1 was spin-coated on the surface opposite to the ultraviolet and infrared cut multilayer film, and a resin film 1 with a thickness of 1 μm was coated. A dye solution 2 was spin-coated on the resin film 1 and a resin film 2 with a thickness of 1.6 μm was coated. A dielectric multilayer film (anti-reflection film) composed of SiO2 and TiO2 was formed by vapor deposition on the two-layer resin film, and an optical filter 3-1 was fabricated.

[0139] <Example 3-2> An optical filter 3-2 was fabricated in the same manner as Example 3-1, except that the content of Compound 11 during the fabrication of the resin film 1 was 5.5% by mass and the resin film 2 was not coated.

[0140] For each optical filter, the transmittance spectra in the wavelength range from 350 nm to 1200 nm at incident angles of 0°, 30°, and 60° were measured with a spectrophotometer. The results are shown in the following table. Also, the spectral transmittance curve of the optical filter 3-1 is shown in Fig. 6.

[0141] Example 3-1 is an example, and Example 3-2 is a comparative example.

[0142]

Table 8

[0143] From the above results, it can be seen that the optical filter of Example 3-1 has high transmittance in the visible light regions of 440 - 490 nm and 500 - 570 nm at both incident angles of 0° and 30°, excellent light shielding property in the infrared light region of 700 nm and above, and low light leakage due to the low maximum transmittance even at oblique incidence of 30° and 60° in the wavelength region of 700 - 850 nm.

[0144] Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention. This application is based on Japanese Patent Application No. 2020-128621 filed on July 29, 2020, the content of which is incorporated herein by reference.

Industrial Applicability

[0145] The optical filter of the present invention has good near-infrared light shielding characteristics in which a decrease in the shielding property of near-infrared light, particularly at a high incident angle, is suppressed while maintaining good shielding property of near-infrared light and good transmittance of visible light, particularly blue light. In recent years, with the progress of high performance, it is useful for applications of information acquisition devices such as cameras and sensors for transportation equipment.

Explanation of Reference Numerals

[0146] 1A, 1B, 1C, 1D... optical filter, 10... substrate, 11... support, 12... resin film, 30... dielectric multilayer film

Claims

1. An optical filter comprising a substrate and a dielectric multilayer film laminated on at least one main surface side of the substrate, The substrate includes a resin film containing a dye (A), which is a near-infrared absorbing dye, and a resin. The dye (A) comprises at least one of the compound shown in the following formula (A1) and the compound shown in the following formula (A2). The optical filter is an optical filter that satisfies all of the following spectral characteristics (iii-1) to (iii-7). (iii-1) Average transmittance T in the spectral transmittance curve at wavelengths of 440-490 nm and an incident angle of 0 degrees. ４４０－４９０（０ｄｅｇ）ＡＶＥ over 85% (iii-2) Average transmittance T in the spectral transmittance curve at wavelengths of 440-490 nm and an incident angle of 30 degrees ４４０－４９０（３０ｄｅｇ）ＡＶＥ over 85% (iii-3) Average transmittance T in the spectral transmittance curve at wavelengths of 500-570 nm and an incident angle of 0 degrees. ５００－５７０（０ｄｅｇ）ＡＶＥ over 90% (iii-4) Average transmittance T in the spectral transmittance curve at wavelengths of 500-570 nm and an incident angle of 30 degrees ５００－５７０（３０ｄｅｇ）ＡＶＥ over 90% (iii-5) Maximum transmittance T in the spectral transmittance curve at wavelengths of 700-850 nm and incident angle of 0 degrees ７００－８５０（０ｄｅｇ）ＭＡＸ less than 3% (iii-6) Maximum transmittance T in the spectral transmittance curve at wavelengths of 700-850 nm and an incident angle of 30 degrees. ７００－８５０（３０ｄｅｇ）ＭＡＸ less than 1% (iii-7) Maximum transmittance T in the spectral transmittance curve at wavelengths of 700-850 nm and an incident angle of 60 degrees. ７００－８５０（６０ｄｅｇ）ＭＡＸ less than 1% 【Chemistry 1】 However, the symbols in formulas (A1) and (A2) are as follows: R １０１ 、R １０６ 、R １０７ each independently represents a hydrogen atom, an alkyl group or an alkoxy group having 1 to 15 carbon atoms which may have a substituent, or an aryl group having 5 to 20 carbon atoms. R １２１ 、R １２８ and R １２９ 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 an aryl group having 5 to 20 carbon atoms. R １０２ to R １０５ 、R １０８ 、R １０９ 、R １２２ to R １２７ 、R １３０ and R １３１ each independently represents a hydrogen atom, an alkyl group or an alkoxy group having 1 to 15 carbon atoms, or an aryl group having 5 to 20 carbon atoms. R １１０ to １１４ and R １３２ to １３６ each independently represents a hydrogen atom, a halogen atom, or an alkyl group or an alkoxy group having 1 to 15 carbon atoms. X － This indicates a monovalent anion. n1 and n2 are independently either 0 or 1. - (CH ２ ) ｎ１ A carbon ring containing -, and - (CH ２ ) ｎ２ The hydrogen atom bonded to the carbon ring containing - may be substituted with a halogen atom, a C1-C15 alkyl group which may have substituents, or a C5-C20 aryl group.

2. The optical filter according to claim 1, wherein the substrate comprises a support and the resin film, and the thickness of the resin film is 5 μm or less.

3. The optical filter according to claim 1 or 2, wherein the resin in the resin film is a polymer composed of an alicyclic compound.

4. In the spectral characteristics (iii-3) described above, the average transmittance T in the spectral transmittance curve at wavelengths of 500 to 570 nm and an incident angle of 0 degrees ５００－５７０（０ｄｅｇ）ＡＶＥ An optical filter according to any one of claims 1 to 3, wherein the ratio is 92% or more.

5. In the spectral characteristics (iii-4) described above, the average transmittance T in the spectral transmittance curve at wavelengths of 500 to 570 nm and an incident angle of 30 degrees ５００－５７０（３０ｄｅｇ）ＡＶＥ An optical filter according to any one of claims 1 to 4, wherein the ratio is 92% or more.

6. In the spectral characteristics (iii-6) described above, the maximum transmittance T in the spectral transmittance curve at wavelengths of 700-850 nm and an incident angle of 30 degrees ７００－８５０（３０ｄｅｇ）ＭＡＸ An optical filter according to any one of claims 1 to 5, wherein the amount is 0.7% or less.

7. In the spectral characteristics (iii-7) described above, the maximum transmittance T in the spectral transmittance curve at wavelengths of 700-850 nm and an incident angle of 60 degrees ７００－８５０（６０ｄｅｇ）ＭＡＸ An optical filter according to any one of claims 1 to 6, wherein the amount is 0.8% or less.

8. The optical filter according to any one of claims 1 to 7, wherein the resin film is one layer or two layers.

9. An imaging apparatus comprising an optical filter according to any one of claims 1 to 8.

Images