Optical filter

Abstract

The present invention relates to an optical filter which has a maximum absorption wavelength at 720 nm to 770 nm, while containing a near-infrared absorbing dye A that is represented by formula (A). (In the formula, R1 represents an alkyl group having 1 to 12 carbon atoms, or the like; R2 represents a secondary alkyl group having 3 to 12 carbon atoms, a tertiary alkyl group having 4 to 12 carbon atoms, a cycloalkyl group having 3 to 13 carbon atoms, an aryl group having 6 to 12 carbon atoms, a heteroaryl group having 3 to 12 carbon atoms or -SiR101R102R103; each of R3 to R7 and R11 to R13 independently represents a hydrogen atom, a monovalent organic group or the like; and X- represents a monovalent anion species.)

Description

[Technical Field]

[0001] The present invention relates to an optical filter that transmits light in the visible range and blocks light in the near-infrared wavelength range. [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 light in the near-infrared wavelength region (hereinafter also referred to as "near-infrared light") in order to reproduce colors well and obtain sharp images.

[0003] Here, the image sensor used in the camera module has high sensitivity in the near-infrared region of 700-800 nm, and even a small amount of light can cause flare and ghosting, so it is necessary to block light in this region. A common method for blocking near-infrared light is to utilize the reflection of dielectric multilayer films. However, light reflected by the dielectric multilayer film can undergo multiple reflections between the lens and the dielectric multilayer film within the camera module, and this reflected light entering the imaging device can cause ghosting and flare. Patent Document 1 describes an optical filter having a wide absorption bandwidth by using multiple types of near-infrared absorbing dyes in order to compensate for the incidence of multiple reflected light in the near-infrared region onto the image sensor by absorption characteristics. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2019 / 022069 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, the optical filter described in Patent Document 1 has a problem in that visible light is also absorbed by multiple near-infrared absorbing dyes added to broaden the absorption range, resulting in a decrease in transmittance in the visible light region, including the blue band, which is particularly important for the visibility of the sensor of the imaging device.

[0006] The present invention aims to provide an optical filter that achieves both high shielding performance, particularly in the 700-800 nm region within the near-infrared range, and high transmittance, particularly in the blue band of 420-500 nm within the visible light range. [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, wherein the substrate has a resin film containing a near-infrared absorbing dye and a resin, and the near-infrared absorbing dye has a maximum absorption wavelength λ in the wavelength region of 720 to 770 nm in dichloromethane. max An optical filter having (A) and containing a near-infrared absorbing dye A represented by the following formula (A).

[0008] [ka]

[0009] [The meanings of the symbols in the above formula are as follows: R 1 Each of these independently represents an optionally substituted C1-C12 alkyl group, an optionally substituted C1-C12 alkenyl group, an optionally substituted C3-C12 cycloalkyl group, an optionally substituted C6-C12 aryl group, or an optionally substituted C7-C13 alaryl group. R 2Each independently represents a secondary alkyl group having 3 to 12 carbon atoms, a tertiary alkyl group having 4 to 12 carbon atoms, a cycloalkyl group having 3 to 13 carbon atoms which may have a substituent, an aryl group having 6 to 12 carbon atoms which may have a substituent, a heteroaryl group having 3 to 12 carbon atoms which may have a substituent, or -SiR 101 R 102 R 103 represents. R 101 ~R 103 Each independently represents an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms which may have a substituent. R 3 ~R 7 Each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms which may have a substituent, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms which may have a substituent, an aralkyl group having 7 to 13 carbon atoms which may have a substituent, -NR 104 R 105 , -C(=O)R 106 , -C(=O)NR 107 R 108 , -SO2R 109 or -SO2NR 110 R 111 represents. Here, R 104 , R 105 Each independently represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms which may have a substituent, an aryl group having 6 to 12 carbon atoms which may have a substituent, or a carbonyl group having 1 to 12 carbon atoms which may have a substituent. R 106 is an alkyl group having 1 to 20 carbon atoms which may have a substituent. R 107 ~R 111 Each independently represents an alkyl group having 1 to 12 carbon atoms which may have a substituent. R 11 ~R 13 Each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms which may have a substituent, an aryl group having 6 to 12 carbon atoms which may have a substituent or -NR 112 R 113 represents. Here, R 112 R 113Each of these is independently an alkyl group having 1 to 12 carbon atoms that may have substituents, an aryl group having 6 to 12 carbon atoms that may have substituents, and a carbonyl group having 1 to 12 carbon atoms that may have substituents. X - This indicates a monovalent anion species. [Effects of the Invention]

[0010] According to the present invention, an optical filter can be provided that achieves both high shielding performance, particularly in the 700-800 nm region within the near-infrared range, and high transmittance, particularly in the blue band of 420-500 nm within the visible light region. [Brief explanation of the drawing]

[0011] [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 the optical filters for Examples 6-2, 6-6, 6-10, 6-12, and 6-14. [Figure 6] Figure 6 is an enlarged view of the near-infrared region of the spectral transmittance curve from Figure 5. [Figure 7] Figure 7 is an enlarged view of the blue band of the spectral transmittance curve in Figure 5. [Modes for carrying out the invention]

[0012] 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 (A) is referred to as compound (A). The same applies to compounds represented by other formulas. A dye consisting of compound (A) is also referred to as dye (A), and the same applies to other dyes. Furthermore, the group represented by formula (a) is also referred to as group (a), and the same applies to groups represented by other formulas.

[0013] 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 transmittance of a substrate and the transmittance of a resin film, including cases where the dye is contained in the resin, are all referred to as "internal transmittance" even when the term "transmittance" is used. On the other hand, the transmittance measured by dissolving the dye in a solvent such as dichloromethane, and the transmittance of an optical filter having a dielectric multilayer film, are measured transmittances.

[0014] 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. The spectral characteristics can be measured using a UV-Vis spectrophotometer. In this specification, the symbol "~" used to indicate a numerical range includes both upper and lower limits.

[0015] <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, wherein the substrate has a resin film containing a near-infrared absorbing dye and a resin. The near-infrared absorbing dye includes near-infrared absorbing dye A, and near-infrared absorbing dye A has a maximum absorption wavelength λ in the wavelength region of 720 to 770 nm in dichloromethane. maxIt is a compound having (A) and a specific structure represented by formula (A) described later. By including a near-infrared absorbing dye in the substrate, the absorption properties of the substrate can prevent multiple reflected light from entering the image sensor. Furthermore, by including a near-infrared absorbing dye A with a specific structure, it is possible to achieve both high shielding performance, particularly in the 700-800 nm region within the near-infrared range, and high transmittance, particularly in the blue band of 420-500 nm within the visible light region. Each dye and resin will be described later.

[0016] 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 Figure 1 is an example in which a dielectric multilayer film 30 is provided on one main surface side of the substrate 10. Note that "having a specific layer on the main surface side of the substrate" is not limited to cases where the layer is in contact with the main surface of the substrate, but also includes cases where another functional layer is provided between the substrate and the layer.

[0017] The optical filter 1B shown in Figure 2 is an example in which a dielectric multilayer film 30 is present on both main surfaces of the substrate 10.

[0018] The optical filter 1C shown in Figure 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 top of the resin film 12 and on the main surface side of the support 11 where the resin film 12 is not laminated.

[0019] The optical filter 1D shown in Figure 4 is an example in which the substrate 10 has a support 11 and a resin film 12 laminated on both main surfaces of the support 11. The optical filter 1D further has a dielectric multilayer film 30 on each of the resin films 12.

[0020] <Near-infrared absorbing dye A> The near-infrared absorbing dye A in the optical filter of the present invention (hereinafter also referred to as "dye A"). ) is a compound represented by the following formula (A).

[0021] [ka]

[0022] [The meanings of the symbols in the above formula are as follows: R 1 Each of these independently represents an optionally substituted C1-C12 alkyl group, an optionally substituted C1-C12 alkenyl group, an optionally substituted C3-C12 cycloalkyl group, an optionally substituted C6-C12 aryl group, or an optionally substituted C7-C13 alaryl group. R 2 Each of these can independently be a secondary alkyl group having 3 to 12 carbon atoms, a tertiary alkyl group having 4 to 12 carbon atoms, a cycloalkyl group having 3 to 13 carbon atoms which may have substituents, an aryl group having 6 to 12 carbon atoms which may have substituents, a heteroaryl group having 3 to 12 carbon atoms which may have substituents, or -SiR 101 R 102 R 103 This shows R 101 ~R 103 Each of these independently represents an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms, which may have substituents. R 3 ~R 7 Each of these independently consists of a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms which may have substituents, an alkoxy group having 1 to 12 carbon atoms which may have substituents, an aryl group having 6 to 12 carbon atoms which may have substituents, and an -NR group which may have substituents. 104 R 105 -C(=O)R 106 -C(=O)NR 107 R 108 , -SO2R 109 or -SO2NR 110 R 111 This shows that R 104 , R 105 Each of these is independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms which may have substituents, an aryl group having 6 to 12 carbon atoms which may have substituents, and a carbonyl group having 1 to 12 carbon atoms which may have substituents.106 R is an alkyl group having 1 to 20 carbon atoms, which may have substituents. 107 ~R 111 Each of these is independently an alkyl group having 1 to 12 carbon atoms, which may have substituents. R 11 ~R 13 Each of these independently consists of a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms which may have substituents, an aryl group having 6 to 12 carbon atoms which may have substituents, or -NR 112 R 113 This shows that R 112 , R 113 Each of these is independently an alkyl group having 1 to 12 carbon atoms that may have substituents, an aryl group having 6 to 12 carbon atoms that may have substituents, and a carbonyl group having 1 to 12 carbon atoms that may have substituents. X - This indicates a monovalent anion species.

[0023] Near-infrared absorbing dye A is a compound having a lepidin skeleton on both sides of the cyanine structure. Here, a specific position of the lepidin skeleton, namely R 2 or R 5 By having a substituent of a specific structure at this position, the maximum absorption wavelength in the near-infrared region was shifted to the longer wavelength side without reducing the transmittance in the blue band. In the compound having the above skeleton, R 2 or R 5 When the position is unsubstituted (hydrogen atom), the maximum absorption wavelength in dichloromethane is usually in the shorter wavelength range than 720 nm. In contrast, the maximum absorption wavelength of dye A is in the wavelength range of 720 to 770 nm.

[0024] R 1 This represents an alkyl group having 1 to 12 carbon atoms that may be substituted, an alkenyl group having 1 to 12 carbon atoms that may be substituted, a cycloalkyl group having 3 to 12 carbon atoms that may be substituted, an aryl group having 6 to 12 carbon atoms that may be substituted, or an alaryl group having 7 to 13 carbon atoms that may be substituted.

[0025] The number of carbon atoms in the alkyl group having 1 to 12 carbon atoms is preferably 1 to 6, more preferably 1 to 5, from the viewpoint of reducing the amount of dye added to the resin film. The alkyl group may be linear or branched, and methyl, ethyl, propyl, isopropyl, and isobutyl groups are preferred.

[0026] The number of carbon atoms in the alkenyl group, which has 1 to 12 carbon atoms, is preferably 1 to 6, more preferably 1 to 5, from the viewpoint of reducing the amount of dye added. The alkenyl group may be linear or branched, but linear is preferred from a synthetic viewpoint.

[0027] The number of carbon atoms in the cycloalkyl group having 3 to 12 carbon atoms is preferably 3 to 8, more preferably 5 to 7, from the viewpoint of stability of the ring structure.

[0028] From a synthetic standpoint, the phenyl group is preferred as the aryl group having 6 to 12 carbon atoms.

[0029] From a synthetic standpoint, the benzyl group is preferred as the alaryl group having 7 to 13 carbon atoms.

[0030] R 1 Examples of substituents in this compound include halogen atoms, alkyl groups, and alkoxy groups. The number of carbon atoms in the substituent is as follows: 1 It is included in the number of carbon atoms.

[0031] R 1 From the viewpoint of improving the solubility of the dye in the resin and reducing the amount added to the resin film, alkyl groups having 1 to 5 carbon atoms are preferred, and methyl, ethyl, propyl, isopropyl, and isobutyl groups are particularly preferred.

[0032] R 2 This includes secondary alkyl groups having 3 to 12 carbon atoms, tertiary alkyl groups having 4 to 12 carbon atoms, optionally substituted cycloalkyl groups having 3 to 13 carbon atoms, optionally substituted aryl groups having 6 to 12 carbon atoms, optionally substituted heteroaryl groups having 3 to 12 carbon atoms, or -SiR 101 R 102R 103 This shows R 101 ~R 103 Each of these independently represents an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms, which may have substituents.

[0033] R 2 Since it has an electron-donating structure, R 2 Compared to the case where the position is unsubstituted (hydrogen atom), the maximum absorption wavelength in the near-infrared region can be shifted to longer wavelengths. Also, R 2 Because it has a structure that does not contain lone pairs of electrons, it can maintain a high transmittance in the blue band without reducing it.

[0034] The number of carbon atoms in the secondary alkyl group having 3 to 12 carbon atoms is preferably 3 to 10, more preferably 3 to 8, from the viewpoint of improving the solubility of the dye and reducing the amount added. Specific examples of secondary alkyl groups include isopropyl group, 1-methylpropyl group, and 1-ethylpropyl group.

[0035] The number of carbon atoms in the tertiary alkyl group having 4 to 12 carbon atoms is preferably 4 to 10, more preferably 4 to 8, from the viewpoint of improving the solubility of the dye and reducing the amount added. Specific examples of tertiary alkyl groups include tert-butyl group, 1,1-dimethylpropyl group, 1,1-dimethylbutyl group, and 1,1-diethylpropyl group.

[0036] The number of carbon atoms in the cycloalkyl group having 3 to 13 carbon atoms is preferably 5 to 8, more preferably 6 to 7, from the viewpoint of stability of the ring structure.

[0037] As an aryl group having 6 to 12 carbon atoms, a phenyl group is preferred from the viewpoint of improving the solubility of the dye and reducing the amount added.

[0038] Examples of heteroaryl groups having 3 to 12 carbon atoms that may have substituents include thienyl, furyl, thiazolyl, oxazolyl, benzothienyl, benzofuryl, benzothiazolyl, benzoxazolyl, and thienothienyl groups. Among these, from the viewpoint of being able to shift the maximum absorption wavelength to a longer wavelength without reducing the transmittance in the blue band, a thienyl group, a furyl group, a thiazolyl group, a thienothienyl group, a benzothienyl group, and a benzofuryl group are preferable. From the viewpoints of simplicity of synthesis and less likelihood of impairing the transmittance in the blue band, a thienyl group and a furyl group are more preferable.

[0039] The position of the bond of the heteroaryl group having 3 to 12 carbon atoms which may have a substituent is not particularly limited. For example, the positions of the bonds in a thienyl group, a furyl group, a thiazolyl group, a thienothienyl group, a benzothienyl group, and a benzofuryl group are preferably the positions shown below.

[0040]

Chemical formula

[0041] -SiR 101 R 102 R 103 The R of 101 ~R 103 The number of carbon atoms of the alkyl group having 1 to 6 carbon atoms in is preferably 1 to 4 from the viewpoint of synthesis. The alkyl group may be linear or branched, and from the viewpoint of improving the solubility of the dye, a methyl group, an ethyl group, an isopropyl group, and a butyl group are preferable.

[0042] -SiR 101 R 102 R 103 The R of 101 ~R 103 As the aryl group having 6 to 12 carbon atoms in, a phenyl group is preferable from the viewpoint of synthesis.

[0043] R 2 Examples of the substituent in include a halogen atom, an alkyl group, an alkoxy group, and the like. Note that the number of carbon atoms of the substituent is included in the number of carbon atoms of the above R 2

[0044] R 2 ​From the viewpoint of improving the solubility of the dye in the resin and not impairing the transmittance in the blue band, a tertiary alkyl group having 4 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms which may have substituents, or a heteroaryl group having 3 to 12 carbon atoms which may have substituents is preferred, and a tert-butyl group, a 1,1-dimethylpropyl group, a phenyl group, a thienyl group, a furyl group, a group represented by the following formula (a), a group represented by the following formula (b), or a group represented by the following formula (c) is more preferred.

[0045] [ka]

[0046] In the above formula, R a1 ~R a3 Each of these independently represents a methyl group, an ethyl group, or an isopropyl group, in which a hydrogen atom may be substituted with a halogen atom.

[0047] R 2 From the viewpoint of being able to shift the maximum absorption wavelength to longer wavelengths, electron-rich heteroaryl groups such as thienyl groups and furyl groups are preferred. From the viewpoint of improving the solubility of the dye in the resin and the steepness of the change in transmittance from the visible region to the near-infrared region, the group represented by formula (a) or the group represented by formula (b) above is preferred, and from the viewpoint of ease of synthesis, the group represented by formula (b) is preferred.

[0048] Of the groups represented by formula (a), the group shown in formula (a1) below is preferred from the viewpoint of reducing the amount of dye added and the availability of reagents.

[0049] [ka]

[0050] From the viewpoint of reducing the amount of dye added and the availability of reagents, the group shown in formula (b1) below is preferred as the group represented by formula (b).

[0051] [Chemical formula]

[0052] As the group represented by formula (c), from the viewpoints of reducing the amount of the dye added and the availability of the reagent, the group represented by the following formula (c1) or formula (c2) is preferable.

[0053] [Chemical formula]

[0054] In formula (A), R 3 ~R 7 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms which may have a substituent, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms which may have a substituent, an aralkyl group having 7 to 13 carbon atoms which may have a substituent, -NR 104 R 105 , -C(=O)R 106 , -C(=O)NR 107 R 108 , -SO2R 109 or -SO2NR 110 R 111 . Here, R 104 , R 105 each independently represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms which may have a substituent, an aryl group having 6 to 12 carbon atoms which may have a substituent, or a carbonyl group having 1 to 12 carbon atoms which may have a substituent. R 106 is an alkyl group having 1 to 20 carbon atoms which may have a substituent. R 107 ~R 111 each independently represents an alkyl group having 1 to 12 carbon atoms which may have a substituent.

[0055] R 3 ~R 7 Having the above structure, the maximum absorption wavelength can be further shifted to a longer wavelength without significantly impairing the transmittance in the blue band.

[0056] Examples of halogen atoms include fluorine, chlorine, and bromine. Among these, fluorine is preferred from the viewpoint of not impairing the transmittance in the blue light band.

[0057] The number of carbon atoms in the alkyl group having 1 to 12 carbon atoms is preferably 1 to 8, more preferably 1 to 6, from the viewpoint of improving the solubility of the dye and reducing the amount added. The alkyl group may be linear or branched, and from the viewpoint of improving solubility while reducing the amount added, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, and hexyl group are preferred.

[0058] The number of carbon atoms in the alkoxy group having 1 to 12 carbon atoms is preferably 1 to 8, more preferably 1 to 6, from the viewpoint of improving the solubility of the dye and reducing the amount added.

[0059] As an aryl group having 6 to 12 carbon atoms, a phenyl group is preferred from the viewpoint of improving the solubility of the dye and reducing the amount added.

[0060] As an alaryl group having 7 to 13 carbon atoms, the benzyl group is preferred from the viewpoint of improving the solubility of the dye and reducing the amount added.

[0061] -NR 104 R 105 R 104 , R 105 The number of carbon atoms in the alkyl group having 1 to 12 carbon atoms is preferably 1 to 8, more preferably 1 to 6, from the viewpoint of improving the solubility of the dye and reducing the amount added. The alkyl group may be linear or branched, and from the viewpoint of improving solubility while reducing the amount added, ethyl, propyl, butyl, isobutyl, and hexyl groups are preferred.

[0062] -NR 104 R 105 R 104 , R 105 In this compound, a phenyl group is preferred as the aryl group having 6 to 12 carbon atoms, from the viewpoint of reducing the amount added.

[0063] -NR104 R 105 R 104 , R 105 In the carbonyl group having 1 to 12 carbon atoms, the number of carbon atoms is preferably 1 to 7, from the viewpoint of improving solubility while reducing the amount added.

[0064] -C(=O)R 106 R 106 The number of carbon atoms in the alkyl group having 1 to 20 carbon atoms is preferably 1 to 12, more preferably 1 to 10, from the viewpoint of improving the solubility of the dye and reducing the amount added. The alkyl group may be linear or branched, and it is preferable to be branched from the viewpoint of improving the solubility of the dye.

[0065] -C(=O)NR 107 R 108 R 107 , R 108 The number of carbon atoms in the alkyl group having 1 to 12 carbon atoms is preferably 1 to 8, more preferably 1 to 6, from the viewpoint of improving the solubility of the dye and reducing the amount added. The alkyl group may be linear or branched, and from the viewpoint of improving solubility while reducing the amount added, ethyl, propyl, butyl, isobutyl, and hexyl groups are preferred.

[0066] -SO2R 109 R 109 The number of carbon atoms in the alkyl group having 1 to 12 carbon atoms is preferably 1 to 8, more preferably 1 to 6, from the viewpoint of improving the solubility of the dye and reducing the amount added. The alkyl group may be linear or branched, and from the viewpoint of improving solubility while reducing the amount added, methyl, ethyl, propyl, butyl, isobutyl, and hexyl groups are preferred.

[0067] -SO2NR 110 R 111 R 110 , R 111The number of carbon atoms in the alkyl group having 1 to 12 carbon atoms is preferably 1 to 8, more preferably 1 to 6, from the viewpoint of improving the solubility of the dye and reducing the amount added. The alkyl group may be linear or branched, and from the viewpoint of improving solubility while reducing the amount added, methyl, ethyl, propyl, butyl, isobutyl, and hexyl groups are preferred.

[0068] R 3 ~R 7 and R 104 ~R 111 Examples of substituents in this compound include halogen atoms, alkyl groups, and alkoxy groups. The number of carbon atoms in the substituent is as follows: 3 ~R 7 It is included in the number of carbon atoms.

[0069] R 3 From the viewpoint of easily maintaining transmittance in the blue band, hydrogen atoms are preferred. 2 Adjacent to R 3 It is thought that the absence of substituents in the pigment reduces the risk of twisting or straining of the pigment skeleton due to steric hindrance between substituents, thus minimizing the decrease in transmittance in the blue band. R 4 ~R 7 From the viewpoint of ease of synthesis and ease of maintaining transmittance in the blue band, hydrogen atoms, fluorine atoms, C1-C12 alkyl groups, and -NR were selected independently. 104 R 105 -C(=O)R 106 -C(=O)NR 107 R 108 , -SO2R 109 or -SO2NR 110 R 111 This is preferable. Here R 104 R is a hydrogen atom, 105 This is a carbonyl group having 1 to 12 carbon atoms.

[0070] R 4 ~R 7 Of these, R 5 It is preferable that a substituent of a specific structure is bonded to the position of R. 5By attaching an electron-withdrawing substituent at this position, the maximum absorption wavelength can be shifted significantly to longer wavelengths without reducing transmittance in the blue band, thereby improving near-infrared shielding. Examples of electron-withdrawing substituents include fluorine atoms and -C(=O)NR 107 R 108 , or -SO2NR 110 R 111 -C(=O)NR is particularly preferred, and from the viewpoint of being able to significantly increase the maximum absorption wavelength to a longer wavelength. 107 R 108 , or -SO2NR 110 R 111 Most preferable.

[0071] R adjacent to the cyanine central chain 4 Therefore, it is thought that substituents that are absent or sterically small are less likely to cause twisting or distortion of the pigment skeleton due to steric hindrance with substituents on the cyanine central chain, which leads to a decrease in blue light transmittance. 4 Hydrogen atoms, fluorine atoms, and methyl groups are particularly preferred.

[0072] Also, R 6 ~R 7 From the viewpoint of ease of synthesis, hydrogen atoms, halogen atoms, C1-C12 alkyl groups which may have substituents, and C6-C12 aryl groups which may have substituents are particularly preferred, independently of each other.

[0073] In equation (A), R 11 ~R 13 Each of these independently consists of a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms which may have substituents, an aryl group having 6 to 12 carbon atoms which may have substituents, or -NR 112 R 113 This shows that R 112 , R 113 Each of these is independently an alkyl group having 1 to 12 carbon atoms that may have substituents, an aryl group having 6 to 12 carbon atoms that may have substituents, and a carbonyl group having 1 to 12 carbon atoms that may have substituents.

[0074] Examples of halogen atoms include fluorine, chlorine, and bromine.

[0075] The alkyl group having 1 to 12 carbon atoms preferably has 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms, from the viewpoint of reducing the amount added. The alkyl group may be linear or branched, but from a synthetic viewpoint, it is preferably linear, and a methyl group is particularly preferred.

[0076] As an aryl group having 6 to 12 carbon atoms, a phenyl group is preferred from the viewpoint of not impairing transmittance in the blue light band.

[0077] -NR 112 R 113 R 112 , R 113 The number of carbon atoms in the alkyl group having 1 to 12 carbon atoms is preferably 1 to 6, and more preferably 1 to 4, from the viewpoint of reducing the amount of additive. Furthermore, the alkyl group may be linear or branched, but from a synthetic viewpoint, linear is preferred, and a methyl group or an ethyl group is particularly preferred.

[0078] -NR 112 R 113 R 112 , R 113 From a synthetic viewpoint, a phenyl group is preferred as the aryl group having 6 to 12 carbon atoms in the compound.

[0079] -NR 112 R 113 R 112 , R 113 In the carbonyl group having 1 to 12 carbon atoms, the number of carbon atoms is preferably 1 to 6 from the viewpoint of reducing the amount added.

[0080] R 11 ~R 13 From the viewpoint of not impairing the transmittance in the blue band, hydrogen atoms are preferred.

[0081] X - This indicates a monovalent anion species. For example, BF4 - , BPh4- , B(C6F5)4 - PF6 - ClO4 - ReO4 - CF3SO3 - CF3COO - , (CF3SO2)2N - (CF3SO2)3C - Examples include p-toluenesulfonyl anions. Among these, BF4 is particularly suitable from the viewpoint of improving the lightfastness of the dye. - PF6 - , (CF3SO2)2N - It is preferable to select from among them.

[0082] As the near-infrared absorbing dye A, compound A1 represented by the following formula (A1) is preferred.

[0083] [ka]

[0084] R in the above formula 1 , R 4 ~R 7 , X - The meaning of R in formula (A), including its definition and preferred form, is 1 , R 4 ~R 7 , X - It has the same meaning as [the other meaning]. R 21 R is a tertiary alkyl group having 4 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms which may have substituents, or a heteroaryl group having 3 to 12 carbon atoms which may have substituents. 21 The group consists of a tert-butyl group, a 1,1-dimethylpropyl group, a phenyl group, a thienyl group, a furyl group, and the above R 2 The group represented by formula (a) described above, or the group represented by formula (b) above, is more preferable.

[0085] More specifically, compound (A1) refers to the compounds shown in the table below. Furthermore, in the compounds shown in the table below, the meaning of each symbol is the same in the left and right lepidin skeletons.

[0086] [Table 1]

[0087] [Table 2]

[0088] [Table 3]

[0089] [Table 4]

[0090] [Table 5]

[0091] [Table 6]

[0092] [Table 7]

[0093] [Table 8]

[0094] The method for producing compound (A) will be explained using Production Example 1 and Production Example 2 of compound (A1) below as examples, but the method for producing compound (A) is not limited to the methods described below. Furthermore, compound (A) can be produced by either Production Example 1 or Production Example 2 below, but Production Example 2 is preferred from the viewpoint of yield.

[0095] [Manufacturing Example 1]

[0096] [ka]

[0097] In the above, Et represents an ethyl group, iPr represents an isopropyl group, DMAc represents N,N-dimethylacetamide, LDA represents lithium diisopropylamide, THF represents tetrahydrofuran, and Ac2O represents acetic anhydride. Furthermore, in HXaq, X represents a monovalent anion species. R in the starting material (X) 4 ~R 7 Compounds in which all atoms are hydrogen atoms can be purchased from general reagent manufacturers, 4 ~R 7 Compounds having substituents other than hydrogen atoms can be synthesized by the following methods described in Japanese Patent Publication No. 4088151 and U.S. Patent No. 6875869.

[0098] [ka]

[0099] <Step 1> In a round-bottom flask, combine the starting material (X) and N,N-diisopropylethylamine, R 1 -I,N,N-dimethylacetamide is added and the mixture is heated and stirred under a nitrogen atmosphere. After the reaction is complete, the reaction solution is cooled with ice and water is added little by little to stop the reaction. The precipitated solid is filtered off and purified by washing to obtain intermediate (1).

[0100] <Step 2> R in a round-bottom flask 21Add (C=O)CH3 and tetrahydrofuran, and stir under a nitrogen stream at -78°C. Add lithium diisopropylamide, stir at -78°C, then gradually add intermediate (1), and stir further at -78°C. Allow the reaction solution to return to room temperature, and add saturated ammonium chloride aqueous solution to stop the reaction. Extract with dichloromethane, and remove the dichloromethane under reduced pressure. Add hexane to the recovered product, filter off the precipitated solid, and collect the filtrate. Remove the hexane contained in the obtained filtrate under reduced pressure, and then purify to obtain intermediate (2).

[0101] <Step 3> Intermediate (2) and tetrahydrofuran are added to a round-bottom flask and stirred under a nitrogen stream at 0°C. Then, methylmagnesium bromide is added and heated and stirred. After the reaction is complete, the reaction is stopped by gradually pouring the reaction solution into a 10% HX aqueous solution at 0°C. This solution is extracted with dichloromethane, the dichloromethane layer is washed with water, and the dichloromethane is removed by distillation under reduced pressure. The resulting powder is washed to obtain intermediate (3).

[0102] <Step 4> Intermediate (3), N,N'-diphenylformamidine, and acetic anhydride are added to a round-bottom flask, and the mixture is heated and stirred under a nitrogen stream. After the reaction is complete, the reaction solution is allowed to return to room temperature, water is added, and the mixture is extracted with dichloromethane. After removing the dichloromethane under reduced pressure, the mixture is crudely purified to obtain intermediate (4).

[0103] <Step 5> Intermediate (3), the crude product of intermediate (4), and dichloromethane are added to a round-bottom flask. Then, triethylamine is slowly added while stirring the reaction solution, and the mixture is stirred under a nitrogen stream. After the reaction is complete, the reaction solution is concentrated, and the resulting powder is washed and purified to obtain compound (A1).

[0104] [Manufacturing Example 2]

[0105] [ka]

[0106] In the above, TsO represents a p-toluenesulfonyloxy group, and Ac2O represents acetic anhydride. Furthermore, in KX, NaX, and NH4X, X represents a monovalent anion species. R in the starting material (Y) 4 ~R 7 Compounds in which all atoms are hydrogen atoms can be purchased from general reagent manufacturers, 4 ~R 7 Compounds having substituents other than hydrogen atoms can be synthesized by the following methods described in Advanced Functional Materials, 26, 881 (2016), Synthetic Communications, 38, 4226 (2008), and Japanese Patent Publication No. 2009-155325.

[0107] [ka]

[0108] <Step 1> Place the starting material (Y) and R in a round-bottom flask. 21 -B(OH)2 or R 21 - Add pinacol boronic acid, Pd(PPh3)4, potassium carbonate, toluene, methanol, and water, and heat and stir. After the reaction is complete, cool the reaction solution on ice and remove the solids in the reaction system by filtration. Add water to the filtrate, extract with ethyl acetate, and remove the solvent by distillation under reduced pressure. The obtained crude product is purified by washing or flash column chromatography to obtain intermediate (5).

[0109] <Step 2> Add intermediate (5) and alkyl iodide or alkyl-p-toluenesulfonic acid ester to a round-bottom flask and heat and stir. After the reaction is complete, if a solid precipitates in the reaction system, filter off the solid and wash to obtain intermediate (6). If no solid precipitates in the reaction system, purify by flash column chromatography to obtain intermediate (6).

[0110] <Step 3> Add intermediate (6), a salt of KX or NaX or NH4X, acetone, methanol, and water to a round-bottom flask and heat and stir. After the reaction is complete, cool the reaction solution with ice and add water and stir to precipitate the target solid. Filter off the obtained solid and wash with isopropanol, ethyl acetate, and hexane in that order to obtain intermediate (7). <Step 4> Add intermediate (7), N,N'-diphenylformamidine, and acetic anhydride to a round-bottom flask and heat and stir under a nitrogen stream. After the reaction is complete, allow the reaction solution to return to room temperature to obtain intermediate (8). Intermediate (8) can be used in the next reaction without isolation.

[0111] <Step 5> Dichloromethane and intermediate (7) are added to an acetic anhydride solution containing intermediate (8) obtained in step 4. Then, triethylamine is slowly added while stirring the reaction solution, and the mixture is stirred under a nitrogen atmosphere. After the reaction is complete, the reaction solution is concentrated, and the resulting powder is washed and purified to obtain near-infrared absorbing dye (A1).

[0112] The spectral characteristics of dye A will be explained. Dye A has its maximum absorption wavelength λ in the 720-770 nm range in dichloromethane. max It has (A). This allows it to efficiently absorb light in the near-infrared region of 700-800 nm. Within the wavelength range of 700-800 nm, from the viewpoint of lowering the transmittance at 750 nm, which is the central wavelength, the absorption wavelength of dye A is preferably in the range of 720 nm to 760 nm, more preferably in the range of 730 nm to 760 nm, and particularly preferably in the range of 735 nm to 760 nm.

[0113] Near-infrared absorbing dye A also has a maximum absorption wavelength λ max In the spectral transmittance curve measured by dissolving dye A in dichloromethane such that the transmittance in (A) is 10%, it is preferable that all of the following spectral characteristics (i-1) to (i-4) are satisfied. (i-1) Average transmittance of 98% or more at wavelengths of 420-500nm (i-2) Minimum transmittance of 97% or more at wavelengths of 420-500 nm (i-3) Average transmittance of 65% or less at wavelengths of 700-800nm (i-4) Transmittance at a wavelength of 750 nm is 80% or less.

[0114] The spectral characteristics (i-1) to (i-2) indicate that dye A has high transmittance in the blue band. Spectral characteristics (i-3) to (i-4) indicate that dye A has high shielding properties in the near-infrared region.

[0115] The spectral characteristic (i-1) is preferably 98.5% or higher, more preferably 99% or higher. The spectral characteristics (i-2) are preferably 97.5% or higher, more preferably 98% or higher. The spectral characteristics (i-3) are preferably 64% or less, more preferably 63.5% or less, even more preferably 60% or less, and particularly preferably 55% or less. The spectral characteristics (i-4) are preferably 79% or less, more preferably 78% or less, even more preferably 60% or less, particularly preferably 30% or less, and most preferably 20% or less. From the perspective of achieving both high transmittance in the blue band and near-infrared shielding, it is preferable that the transmittance of (i-1) and (i-2) be high, and the transmittance of (i-3) and (i-4) be low.

[0116] It is preferable that dye A satisfies specific spectral characteristics even in the resin. The near-infrared absorbing dye A is preferably further satisfied with the following spectral characteristics (ii-1) and (ii-2) in the spectral transmittance curve of the coating film obtained by dissolving or dispersing dye A in a resin. Here, the resin is the resin contained in the resin film. (ii-1) Maximum absorption wavelength λ of the near-infrared absorbing dye A in dichloromethane max When the transmittance of (A) is set to 10%, the shortest wavelength in the wavelength range of 500 nm or more at which the transmittance becomes 80% is T80(A). short The longest wavelength is T80(A)long year, The maximum absorption wavelength λ of the near-infrared absorbing dye A in the resin max When the internal transmittance of (pA) is adjusted to 10%, the shortest wavelength in the wavelength range of 500 nm or more at which the internal transmittance becomes 80% is defined as T80(pA). short The longest wavelength is T80(pA) long When this is the case, all of the following relationships are satisfied. |T80(A) short -T80(pA) short | ≤ 60nm |T80(A) long -T80(pA) long |≦45nm (ii-2) Maximum absorption wavelength λ max Transmittance and λ in (A) max When the internal transmittance at (pA) is adjusted to 10%, the average absolute value of the difference between the transmittance in dichloromethane at wavelengths of 420-500 nm and the internal transmittance of the spectral transmission curve in the resin at wavelengths of 420-500 nm is 8% / nm or less.

[0117] Satisfying the above spectral characteristics (ii-1) and (ii-2) means that the change in the absorption characteristics of dye A between the resin and dichloromethane is small. In other words, any resin that satisfies the above spectral characteristics (ii-1) and (ii-2) can be preferably used without impairing the properties of dye A. Resins will be described later.

[0118] The spectral characteristics (ii-1) preferably satisfy the following relationship. |T80(A) short -T80(pA) short |≦45nm |T80(A) long -T80(pA) long | ≤ 35nm The spectral characteristics (ii-2) are preferably 5% / nm or less.

[0119] The near-infrared absorbing dye A is further represented in the spectral transmittance curve of the coating film obtained by dissolving or dispersing dye A in a resin, where the maximum absorption wavelength λ of dye A in the resin is present. max When the internal transmittance of (pA) is adjusted to 10%, it is preferable that all of the following spectral characteristics (iii-1) to (iii-3) are satisfied. (iii-1) The average internal transmittance at wavelengths of 420-500 nm is 95% or higher, and the minimum internal transmittance at wavelengths of 420-500 nm is 93% or higher. (iii-2) Average internal transmittance at wavelengths of 700-800 nm is 50% or less. (iii-3) Internal transmittance at a wavelength of 750 nm is 30% or less.

[0120] Spectral characteristics (iii-1) to (iii-3) indicate that dye A exhibits high transmittance in the blue band and high shielding in the near-infrared region, both in dichloromethane and in the resin.

[0121] The spectral characteristics (iii-1) are such that the average internal transmittance is preferably 95.5% or higher, more preferably 96% or higher, and the minimum internal transmittance is preferably 93.5% or higher, more preferably 94% or higher. The spectral characteristics (iii-2) are preferably 49% or less, more preferably 48% or less, even more preferably 45% or less, and particularly preferably 40% or less. The spectral characteristics (iii-3) are preferably 29% or less, more preferably 28% or less, even more preferably 20% or less, and particularly preferably 15% or less.

[0122] As shown in Figure 1 or Figure 2, when the substrate consists only of a resin film, the content of dye A in the resin film is preferably 0.001 parts by mass or more, more preferably 0.005 parts by mass or more, and even more preferably 0.01 parts by mass or more, per 100 parts by mass of resin. If the concentration of the dye becomes too high, it may become difficult to dissolve in the resin or reduce the transmittance in the visible light region. Furthermore, if the pigment concentration is too high, it can lower the glass transition temperature (Tg) of the resin, potentially leading to poor heat resistance or reduced adhesion to the multilayer film. Therefore, from the viewpoint of preventing pigment deposition, loss of transmittance in the visible light region, or impairing the properties of the resin, a concentration of 5 parts by mass or less is preferable, 2 parts by mass or less is more preferable, and 1 part by mass or less is even more preferable. As shown in Figure 3 or Figure 4, when the substrate consists of a support and a resin film, the content of dye A is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and even more preferably 1 part by mass or more, per 100 parts by mass of resin. If the concentration of the dye is too high, it may become difficult to dissolve in the resin. Also, if the concentration of the dye is too high, it may lower the glass transition temperature (Tg) of the resin, which may result in poor heat resistance or reduced adhesion to the multilayer film. Therefore, from the viewpoint of preventing dye precipitation or not impairing the properties of the resin, the concentration of the dye is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, and even more preferably 20 parts by mass or less, relative to the resin.

[0123] <Resin> The resin used in the resin film is not limited to transparent resins, and 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, poly-paraphenylene 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. These resins may be used individually or in combination of two or more types.

[0124] Among them, from the viewpoints that dye A is likely to satisfy the above spectral characteristics (ii-1) and (ii-2), and the compatibility with dye A, a resin having a high refractive index is preferred, a resin having a refractive index of 1.55 or more is preferred, a resin having a refractive index of 1.56 or more is more preferred, and a resin having a refractive index of 1.57 or more is particularly preferred. Since a resin having a high refractive index is electron-rich, it tends to have excellent compatibility with dyes. Although the upper limit of the refractive index is not particularly specified, about 1.70 is preferred from the viewpoints of easy availability and the like. The refractive index of the resin in this specification refers to the refractive index at a wavelength of 589 nm at 20°C. Specifically, polyimide resins and polyester resins can be mentioned. Among them, polyimide resins are particularly preferred from the viewpoint of excellent heat resistance.

[0125] <Near-infrared absorbing dye B> The near-infrared absorbing dye preferably further contains a near-infrared absorbing dye B that satisfies the following spectral characteristics (iv-1) and (iv-2). (iv-1) Having a maximum absorption wavelength λ in the wavelength range of 670 to 730 nm in dichloromethane max (B) (iv-2) The maximum absorption wavelength λ of the near-infrared absorbing dye B max (B) and the maximum absorption wavelength λ of the near-infrared absorbing dye A max The following relationship holds between (A) λ max (B) < λ max (A)

[0126] By the near-infrared absorbing dye containing, together with dye A, a dye B having a maximum absorption wavelength on the shorter wavelength side than dye A, the absorption width can be widened, and light in the near-infrared band of 700 to 800 nm can be absorbed more efficiently.

[0127] Examples of dye B include squarylium dyes, cyanine dyes, rhodamine dyes, etc., and squarylium dyes are preferred from the viewpoints of sharpness of absorption and high absorption coefficient.

[0128] As the squarylium dye, one or more compounds selected from the compounds represented by the following formula (B1), the compounds represented by the formula (B2), and the compounds represented by the formula (B3) are preferred.

[0129] [ka]

[0130] [ka]

[0131] However, the symbols in formulas (B1) to (B3) are as follows: X is a divalent organic group represented by the following formula (1) or formula (2), in which one or more hydrogen atoms may be independently substituted with an alkyl or alkoxy group having 1 to 12 carbon atoms. -(CH2) n1 - …(1) In equation (1), n1 is either 2 or 3. -(CH2) n2 -O-(CH2) n3 - …(2) In equation (2), n2 and n3 are independent integers between 0 and 2, and n2 + n3 is either 1 or 2. R 1 This independently represents a saturated or unsaturated hydrocarbon group having 1 to 12 carbon atoms, which may contain a saturated ring structure and may be branched, a saturated cyclic hydrocarbon group having 3 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an alaryl group having 7 to 13 carbon atoms. R 2 and R 3 This independently represents a hydrogen atom, a halogen atom, or an alkyl or alkoxy group having 1 to 10 carbon atoms. R 4 This is a hydrocarbon group having 5 to 25 carbon atoms and having at least one branch, in which one or more hydrogen atoms may be independently substituted with halogen atoms, hydroxyl groups, carboxyl groups, sulfo groups, or cyano groups, and may contain unsaturated bonds, oxygen atoms, or saturated or unsaturated ring structures between carbon atoms. R 5This is a hydrocarbon group having 1 to 25 carbon atoms, in which one or more hydrogen atoms may be independently substituted with halogen atoms, hydroxyl groups, carboxyl groups, sulfo groups, or cyano groups, and which may contain unsaturated bonds, oxygen atoms, or saturated or unsaturated ring structures between carbon atoms. R 6 and R 7 This independently represents a hydrogen atom, a halogen atom, or an alkyl or alkoxy group having 1 to 10 carbon atoms. n is either 2 or 3. In formulas (B1) to (B3), X is preferably a divalent organic group represented by formula (3). -CR 8 2-(CR 9 2) n4 - …(3) Formula (3) represents a divalent group in which the left side is bonded to a benzene ring and the right side is bonded to N, and n4 is 1 or 2. n4 is preferably 1. 8 Each of these is independently a C1-C12 alkyl or alkoxy group which may be branched, and a C1-C6 branched alkyl or alkoxy group is preferred. 9 Each of these is independently a hydrogen atom or a C1-C12 alkyl or alkoxy group which may be branched, and a hydrogen atom or a C1-C6 alkyl or alkoxy group which may be branched is preferred.

[0132] X is particularly preferably one of the divalent organic groups represented by formulas (11-1) to (12-3). Formulas (11-1) to (12-3) all represent divalent groups in which the left side is bonded to a benzene ring and the right side is bonded to nitrogen. -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)2- …(11-4) -C(CH3)2-C(CH3)(C2H5)- …(11-5) -C(CH3)2-C(CH3)(C3H7)- …(11-6) -C(CH3)2-C(CH3)(CH(CH3)2)- …(11-7) -C(CH3)2-CH2-CH2- …(12-1) -C(CH3)2-CH2-CH(CH3)- …(12-2) -C(CH3)2-CH(CH3)-CH2- …(12-3)

[0133] In formulas (B1) to (B3), X is preferably any of the groups (11-1) to (11-6), with group (11-1) or group (11-6) being more preferred.

[0134] In dye (B1), R 1 From the viewpoint of improving heat resistance and reliability, alkyl or alkoxy groups having 1 to 12 carbon atoms, which may have independent branching, are preferred, and alkyl or alkoxy groups having 1 to 6 carbon atoms, which may have branching, are more preferred. To increase solubility in the resin, branched alkyl groups having 1 to 6 carbon atoms are even more preferred. Also, in the pigment (B1), R 2 and R 3 The following are preferred independently: a hydrogen atom, a halogen atom, or an alkyl or alkoxy group having 1 to 6 carbon atoms. 2 and R 3 In both cases, a hydrogen atom is more preferable.

[0135] R in pigment (B1) 4 Preferably, it is a branched hydrocarbon group having 5 to 25 carbon atoms, represented by the following formula (4). -CH 3-m R 41 m …(4) However, in equation (4), m is 1, 2, or 3, and R 41 Each independently represents a linear or branched hydrocarbon group (which is branched when m is 1) that may contain unsaturated bonds, oxygen atoms, or saturated or unsaturated ring structures between carbon atoms, and m R 41 The total number of carbon atoms is 4 to 24. From the viewpoint of solubility in resin, m is preferably 2 or 3.

[0136] R 41 Examples of the saturated ring structure that it may have include cyclic ethers having 4 to 14 carbon atoms, cycloalkanes, adamantane rings, diamantane rings, and the like. Examples of the unsaturated ring structure include benzene, toluene, xylene, furan, benzofuran, and the like. When it has a ring structure, R 41 is represented by a number including the number of carbon atoms in the ring.

[0137] Also, R 4 is preferably a branched hydrocarbon group having 6 to 20 carbon atoms that does not have a substituent independently from the viewpoints of solubility in organic solvents and resins. The number of carbon atoms of R 4 is more preferably 6 to 17, and even more preferably 6 to 14.

[0138] The structural formulas of the dye (B1-i) in which X is the group (11-1) on both the left and right and the dye (B1-ii) which is the group (12-1) are shown below.

[0139]

Chemical formula

[0140] In formula (B2) and formula (B3), R 1 is more preferably, independently from the viewpoints of solubility, heat resistance, and the sharpness of the change near the boundary between the visible region and the near-infrared region in the spectral transmittance curve, a group represented by formula (4-1) or formula (4-2).

[0141]

Chemical formula

[0142] In formula (4-1) and formula (4-2), R 11 , R 12 , R 13 , R 14 and R 15 each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms.

[0143] R of pigment (B2) and pigment (B3) 2 and R 3 These are preferably, independently, a hydrogen atom, a halogen atom, or an alkyl or alkoxy group having 1 to 6 carbon atoms, with a hydrogen atom being more preferred in any case.

[0144] R of pigment (B2) 5 From the viewpoint of light resistance, preferably, the C1-C12 alkyl or alkoxy group may be branched, or the C6-C16 hydrocarbon group having an unsaturated ring structure is preferred. Examples of unsaturated ring structures include benzene, toluene, xylene, furan, and benzofuran. 5 Independently, a branched alkyl or alkoxy group having 1 to 12 carbon atoms is more preferred.

[0145] R of pigment (B3) 6 and R 7 From the viewpoint of not significantly increasing the molecular weight, and considering the amount added, reactivity to squarylium, and solubility in resins, hydrogen atoms, fluorine atoms, and alkyl groups having 1 to 5 carbon atoms are more preferable.

[0146] The following are the structural formulas of dyes (B2-i) and (B3-i) in which X is a preferred group. In formulas (B2-i) and (B3-i), R 1 ~R 3 , R 5 ~R 7 R in equations (B2) and (B3) is 1 ~R 3 , R 5 ~R 7 It has the same meaning as R. 21 , R 22 Each of these independently comprises a hydrogen atom, or a C1-C6 alkyl or alkoxy group which may have branches, R 23 , R 24 Each of these is independently a branched alkyl or alkoxy group having 1 to 6 carbon atoms.

[0147] [ka]

[0148] Dye (B1) can be synthesized by the manufacturing method described in International Publication No. 2014 / 088063. Dyes (B2) and (B3) can be synthesized by the manufacturing method described in International Publication No. 2016 / 133099.

[0149] The content of dye B in the resin film is preferably 0.005 to 5 parts by mass, more preferably 0.01 to 2 parts by mass, per 100 parts by mass of resin, when the substrate consists of a resin film. When the substrate consists of a support and a resin film, the content of dye B is preferably 0.5 to 30 parts by mass, more preferably 1 to 20 parts by mass, per 100 parts by mass of resin.

[0150] <Other pigments> The resin film may contain other dyes besides near-infrared absorbing dyes, such as ultraviolet absorbing dyes. Examples of UV-absorbing dyes include oxazole, merocyanine, cyanine, naphthalimide, oxadiazole, oxazine, oxazolidine, naphthalic acid, styryl, anthracene, cyclic carbonyl, and triazole dyes.

[0151] Dye A, dye B, and other dyes may each consist of one type of compound, or they may contain two or more types of compounds.

[0152] <Spectral properties of resin films> The resin film preferably satisfies all of the following spectral characteristics (v-1) to (v-6). (v-1) In the region of wavelengths above 500 nm, the shortest wavelength at which the internal transmittance is 50% is in the range of 620-680 nm. (v-2) The average internal transmittance in the wavelength range of 420-500 nm is 94% or higher, and the minimum internal transmittance is 85% or higher. (v-3) The average internal transmittance in the wavelength range of 700-800 nm is 50% or less. (v-4) The average internal transmittance in the wavelength range of 700-750 nm is 8% or less. (v-5) The internal transmittance at 750 nm is 30% or less.

[0153] The spectral characteristic (v-1) represents the wavelength range in which the transmission and absorption bands change. The fact that this wavelength range is in the 620-680 nm range means that there is a high degree of freedom in designing the wavelength range of the transmission and absorption bands. For example, the absorption band of the resin film can be freely designed according to the wavelength at which the transmission and reflection bands of the dielectric multilayer film change. (v-2) indicates that the resin film has high transmittance in the blue band of 420-500 nm, and the spectral characteristics (v-3)-(v-5) indicate that the resin film has high shielding in the near-infrared region of 700-800 nm.

[0154] The spectral characteristics (v-2) are such that the average internal transmittance is preferably 94.3% or higher, more preferably 94.5% or higher, and the minimum internal transmittance is preferably 85.5% or higher, more preferably 86% or higher. The spectral characteristics (v-3) are preferably 47.5% or less, more preferably 45% or less, even more preferably 40% or less, and particularly preferably 30% or less. The spectral characteristic (v-4) is preferably 7.5% or less, more preferably 7% or less, and even more preferably 6% or less. The spectral characteristic (v-5) is preferably 29% or less, more preferably 28% or less, even more preferably 20% or less, and particularly preferably 15% or less.

[0155] <Base material composition> The substrate in this filter may have a single-layer structure or a multi-layer structure. Furthermore, the material of the substrate may be an organic or inorganic material, as long as it is a transparent material that transmits visible light, and there are no particular restrictions on its material. When the substrate has a single-layer structure, a resin substrate consisting of a resin film containing a resin and a near-infrared absorbing dye is preferred. When the substrate has a multilayer structure, a composite substrate is preferred in which a resin film containing a near-infrared absorbing dye 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.

[0156] Glass and crystalline materials are preferred as transparent inorganic materials. Examples of glass that can be used as a support include phthalate 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. As for the glass, phosphate-based glass and phthalate-based glass are preferred from the viewpoint of being able to absorb infrared light (especially 900-1200 nm). Note that "phosphate-based glass" also includes silicate glass in which part of the glass skeleton is composed of SiO2.

[0157] 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).

[0158] Examples of crystalline materials that can be used as supports include birefringent crystals such as quartz, lithium niobate, and sapphire.

[0159] 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.

[0160] The resin film can be formed by preparing a coating solution by dissolving or dispersing a near-infrared absorbing dye, 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.

[0161] 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 coating solution to the support, a resin film is formed by drying. If the coating solution contains resin raw material components, further curing treatments such as thermosetting or photocuring are performed.

[0162] 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 a near-infrared absorbing dye, the resin film may 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 a dye 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.

[0163] 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.

[0164] The thickness of the resin film is preferably 20 to 150 μm when the substrate is a single-layer structure consisting of a resin film (resin substrate). When the substrate is a multilayer structure (composite substrate) having a support and a resin film laminated on at least one main surface of the support, the thickness of the resin film is preferably 0.3 to 20 μm. Furthermore, if the optical filter has two or more resin films, it is preferable that the total thickness of each resin film is within the above range.

[0165] 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 optical elements. When the substrate is a resin substrate consisting of a resin film, it is preferably 20 to 150 μm, and when the substrate is a composite substrate comprising a support and a resin film, it is preferably 50 to 300 μm.

[0166] <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.

[0167] In this filter, it is preferable that the dielectric multilayer film satisfies all of the following spectral characteristics (vi-1) to (vi-4). (vi-1) IR at an angle of incidence of 0° 50 It is in the range of 650-800 nm. (vi-2) UV at an incident angle of 0° 50 It is in the range of 385-425nm (vi-3) In the spectral transmittance curves for incident angles of 0° and 30°, the average transmittance of light in the wavelength range of 435-650nm is 88% or higher. (vi-4) In the spectral transmittance curves for incident angles of 0° and 30°, the average transmittance of light in the wavelength range of 750-1000 nm is 10% or less. Here's IR 50 This refers to the wavelength in the 600-800 nm range at which the transmittance is 50%. UV 50 This refers to the wavelength in the 380-440nm range at which the transmittance is 50%.

[0168] The optical filter of the present invention, by combining such dielectric multilayer film with the resin film described above, can achieve both high transmittance in the blue band and high shielding in the near-infrared band.

[0169] 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.

[0170] An NIR reflective layer is a dielectric multilayer film designed to block near-infrared light. For example, an NIR reflective layer may have wavelength selectivity that transmits visible light and primarily reflects near-infrared light outside the light-blocking region of the absorbent 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.

[0171] 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.

[0172] 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.

[0173] The NIR reflective layer preferably has a total number of layers of dielectric multilayer films constituting the reflective layer, more preferably 25 layers or more, and even more preferably 30 layers or more, from the viewpoint of light shielding in the near-infrared wavelength region. However, as the total number of layers increases, ripples and warping may occur, and the film thickness may increase, so the total number of layers is preferably 100 layers or less, more preferably 75 layers or less, and even more preferably 60 layers or less. Furthermore, the thickness of the reflective layer is preferably 2 to 10 μm overall from the viewpoint of reducing the warping of the optical filter.

[0174] Furthermore, for the formation of dielectric multilayer films, vacuum deposition processes such as CVD, sputtering, and vacuum evaporation, as well as wet deposition processes such as spraying and dipping, can be used.

[0175] 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.

[0176] 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 multilayer films, similar to the reflective layer.

[0177] 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.

[0178] <Spectral characteristics of optical filters> The optical filter of the present invention preferably satisfies all of the following spectral characteristics (vii-1) to (vii-6). (vii-1) The average transmittance at wavelengths of 420-500 nm at an incident angle of 0° is 90% or higher, and the minimum transmittance is 83% or higher. (vii-2) The average transmittance at wavelengths of 600-700 nm at an incident angle of 0° is 25% or more. (vii-3) The average transmittance of wavelengths 710-1100 nm at an incident angle of 0° is 2% or less. (vii-4) The average transmittance of wavelengths 700-800 nm at an incident angle of 0° is 3% or less. (vii-5) Maximum transmittance of 5% or less at wavelengths of 700-800 nm at an incident angle of 0° (vii-6) The average of the absolute values ​​of the difference between the transmittance at wavelengths of 600-700 nm at an incident angle of 0° and the transmittance at wavelengths of 600-700 nm at an incident angle of 30° is 7% / nm or less.

[0179] This filter, which satisfies all of the spectral characteristics (vii-1) to (vii-6), is an optical filter that achieves both high transmittance in the blue band, particularly 420-500 nm, within the visible light region, and high shielding in the 700-800 nm region, within the near-infrared region.

[0180] The spectral characteristics (vii-1) indicate high transmittance in the blue band from 420 to 500 nm, with an average transmittance of preferably 91% or higher, more preferably 92% or higher, and particularly preferably 93% or higher. Furthermore, the minimum transmittance is preferably 84% or higher, and more preferably 84.5% or higher.

[0181] The spectral characteristics (vii-2) mean that the transmittance is high in the 600-700 nm band, preferably 30% or more, and more preferably 35% or more.

[0182] The spectral characteristics (vii-3) indicate high shielding performance in a broad near-infrared region from 710 to 1100 nm, preferably 1.5% or less, and more preferably 1% or less.

[0183] The spectral characteristics (vii-4) indicate high shielding in the near-infrared region of 700-800 nm, preferably 2.8% or less, more preferably 2.7% or less, and even more preferably 2.5% or less.

[0184] The spectral characteristics (vii-5) indicate high shielding in the near-infrared region of 700-800 nm, preferably 4.9% or less, more preferably 4.8% or less, and even more preferably 4.5% or less.

[0185] The spectral characteristics (vii-6) mean that the difference in the spectral transmittance curve at incident angles of 0° and 30° is small, preferably 5% or less, and more preferably 3% or less. [Examples]

[0186] 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. Note that unless the angle of incidence is specifically stated, the spectral characteristics are measured at an angle of incidence of 0° (perpendicular to the main surface of the optical filter).

[0187] The dyes used in each example are as follows: Compound A1-1 (cyanine compound): Synthesized by the method shown in Example 1-1 described later. Compound A1-4 (cyanine compound): Synthesized by the method shown in Example 1-2 below. Compounds A1-5 (cyanine compounds): These were synthesized by the method shown in Example 1-3, described later. Compound A1-7 (cyanine compound): Synthesized by the method shown in Example 1-4 below. Compound A1-10 (cyanine compound): Synthesized by the method shown in Example 1-5 below. Compound A1-60 (cyanine compound): Synthesized by the method shown in Example 1-6 below. Compound A1-61 (cyanine compound): Synthesized by the method shown in Example 1-7 described later. Compound A1-63 (cyanine compound): Synthesized by the method shown in Example 1-8 described later. Compound A1-79 (cyanine compound): Synthesized by the method shown in Examples 1-9 described later. Compound A1-158 (cyanine compound): Synthesized by the method shown in Example 1-10 below. Compound A1-253 (cyanine compound): Synthesized by the method shown in Example 1-11, described later. Compound A1-269 (cyanine compound): Synthesized by the method shown in Example 1-12 below. Compound A1-272 (cyanine compound): Synthesized by the method shown in Example 1-13 described later. Compound C1 (cyanine compound): Manufactured by Tokyo Chemical Industry Co., Ltd. (Product number: C0426) Compound C2 (cyanine compound): Synthesized according to Japanese Patent Publication No. 2013-205820. Compound C3 (cyanine compound): Manufactured by Few Chemicals (product number: S2137) Compound C4 (cyanine compound): Synthesized based on Dyes and Pigments, 73, 344-352 (2007). Compound C5 (cyanine compound): Synthesized according to International Publication No. 2019 / 168090. Compound C6 (phthalocyanine compound): Manufactured by Yamada Chemical Co., Ltd. (Product number: FDR-026) (Structure unknown) Compound B2-1 (squallium compound): Synthesized according to International Publication No. 2016 / 133099. Compound B2-2 (squallium compound): Synthesized according to International Publication No. 2016 / 133099.

[0188] [ka]

[0189] [ka]

[0190] [ka]

[0191] [ka]

[0192] [ka]

[0193] [ka]

[0194] Examples 1-1 to 1-13 below show examples of the synthesis of each cyanine compound. Examples 1-1 to 1-13 are examples of actual cases.

[0195] <Example 1-1: Synthesis of compound A1-1 (cyanine compound)>

[0196] [ka]

[0197] In the above, Et represents an ethyl group, iPr represents an isopropyl group, DMAc represents N,N-dimethylacetamide, LDA represents lithium diisopropylamide, THF represents tetrahydrofuran, and Ac2O represents acetic anhydride. <Step 1> In a 2000 mL round-bottom flask, isatoic anhydride (50 g, 306.5 mmol), N,N-diisopropylethylamine (79.2 g, 613.0 mmol), iodomethane (87.0 g, 613.0 mmol), and N,N-dimethylacetamide (500 mL) were added, and the mixture was heated and stirred at 50°C for 18 hours under a nitrogen stream. After the reaction was complete, the reaction solution was cooled with ice, and 600 mL of water was added little by little to stop the reaction. At this time, a white solid precipitated in the reaction vessel. The solution was stirred with ice for 10 minutes, and the precipitated white solid was filtered off. The obtained white solid was washed with isopropanol and then hexane to obtain intermediate 1A (47.0 g, yield 86.6%). <Step 2> 200 mL of tert-butyl methyl ketone (20.4 g, 203.2 mmol) and tetrahydrofuran (200 mL) were added to a 2000 mL round-bottom flask and stirred under a nitrogen stream at -78°C. 200 mL of lithium diisopropylamide (1.0 mol / L in hexane) was added using a dropping funnel and stirred at -78°C for 1 hour. Then, intermediate 1A (24.0 g, 135.5 mmol), dispersed in 300 mL of tetrahydrofuran, was gradually added and stirred at -78°C for 10 minutes. The reaction solution was allowed to return to room temperature over 1 hour, and the reaction was stopped by adding saturated ammonium chloride aqueous solution. After extracting the organic layer, the aqueous layer was also extracted with dichloromethane. The organic layers were then removed by distillation under reduced pressure, hexane was added, and the precipitated pale yellow powder was filtered off and the filtrate was collected. The hexane contained in the obtained filtrate was removed by reduced pressure distillation, and then the mixture was purified by flash column chromatography (hexane / ethyl acetate) to obtain intermediate 2A (21.0 g, yield 71.9%). <Step 3> Intermediate 2A (6.0 g, 27.9 mmol) and tetrahydrofuran (100 mL) were added to a 1000 mL round-bottom flask and stirred at 0°C under a nitrogen stream. Then, methylmagnesium bromide (12% tetrahydrofuran solution) (100 g, 75.9 mol) was added dropwise using a funnel, and the mixture was heated and stirred at 60°C for 1 hour. After the reaction was complete, the reaction solution was gradually poured into a 10% hexafluorophosphate aqueous solution (420 mL) at 0°C and stirred at 0°C for 10 minutes to stop the reaction. This solution was extracted with dichloromethane, the dichloromethane layer was washed with water, and the dichloromethane was removed by distillation under reduced pressure. The resulting flesh-colored powder was washed with hexane to obtain intermediate 3A (7.8 g, yield 78.0%). <Step 4> In a 300 mL round-bottom flask, intermediate 3A (4.5 g, 12.5 mmol), N,N'-diphenylformamidine (4.9 g, 25.0 mmol), and acetic anhydride (25 mL) were added, and the mixture was heated and stirred at 150 °C for 1 hour under a nitrogen stream. After the reaction was complete, the reaction solution was allowed to return to room temperature, water was added, and the mixture was extracted with dichloromethane. After removing the dichloromethane under reduced pressure, the mixture was crudely purified by flash column chromatography (dichloromethane / ethyl acetate) to obtain intermediate 4A (8.15 g, crude). <Step 5> Intermediate 3A (3.25 g, 9.1 mmol), the crude product of intermediate 4A (8.15 g), and dichloromethane (100 mL) were added to a 500 mL round-bottom flask. Then, triethylamine (9.2 g, 90.5 mmol) was slowly added while stirring the reaction solution, and the mixture was stirred under a nitrogen stream at room temperature for 20 hours. After the reaction was complete, the reaction solution was concentrated, and the resulting dark green powder was washed with ethyl acetate. The solid was further washed with a solvent of dichloromethane:ethyl acetate = 2:1 to obtain A1-1 (4.9 g, yield 77.5% (total of 2 steps)).

[0198] <Example 1-2: Synthesis of Compound A1-4 (Cyanine Compound)> The synthesis was carried out in the same manner as in Example 1-1, except that tert-butylmethyl ketone in synthesis step 2 of Example 1-1 was replaced with acetophenone.

[0199] <Example 1-3: Synthesis of Compounds A1-5 (Cyanine Compounds)> The synthesis was carried out in the same manner as in Example 1-1, except that iodomethane in synthesis step 1 of Example 1-1 was replaced with iodoethane and the reaction time was changed from 18 hours to 72 hours.

[0200] <Example 1-4: Synthesis of Compounds A1-7 (Cyanine Compounds)> The synthesis was carried out in the same manner as in Example 1-1, except that tert-butylmethyl ketone in synthesis step 2 of Example 1-1 was replaced with 2',4',6'-trimethylacetophenone.

[0201] <Example 1-5: Synthesis of Compound A1-10 (Cyanine Compound)>

[0202] [ka]

[0203] <Step 1> In a 1000 mL round-bottom flask, 2-chlorolepidin (10.0 g, 56.3 mmol), 3,5-bis(trifluoromethyl)phenylboronic acid (17.4 g, 67.6 mmol), Pd(PPh3)4 (1.95 g, 1.69 mmol), toluene (180 mL), methanol (50 mL), and water (100 mL) were added, and the mixture was heated and stirred at 80°C for 17 hours. After the reaction was complete, the reaction solution was allowed to return to room temperature, and the solids in the reaction system were removed by filtration. Water was added to the obtained filtrate, and the mixture was extracted with ethyl acetate. The ethyl acetate was removed by distillation under reduced pressure. The resulting brown solid was washed with a small amount of isopropanol, and then washed again with hexane to obtain intermediate 1B (17.2 g, yield 86.0%). <Step 2> Intermediate 1B (6.0 g, 16.9 mmol) and methyl p-toluenesulfonate (16.0 g, 85.9 mmol) were added to a 100 mL round-bottom flask, and the mixture was heated and stirred at 140°C for 18 hours under a nitrogen stream. After the reaction was complete, the reaction solution was cooled with ice, and ethyl acetate was added to precipitate a light brown powder. The obtained powder was filtered and washed with ethyl acetate and then hexane to obtain intermediate 2B (7.6 g, yield 82.8%). <Step 3> Intermediate 2B (7.6 g, 14.0 mmol), potassium hexafluorophosphate (3.3 g, 18.2 mmol), acetone (15 mL), methanol (15 mL), and water (15 mL) were added to a 300 ml round-bottom flask and heated and stirred at 80°C for 1 hour. After the reaction was complete, the reaction solution was cooled on ice and water was added to precipitate a light brown powder. The obtained powder was filtered and washed with isopropanol, ethyl acetate, and hexane in that order to obtain intermediate 3B (6.9 g, yield 95.8%). <Step 4> In a 300 mL round-bottom flask, intermediate 3B (3.45 g, 6.7 mmol), N,N'-diphenylformamidine (1.97 g, 10.0 mmol), and acetic anhydride (7 mL) were added, and the mixture was heated and stirred at 150 °C for 5 hours under a nitrogen stream. After the reaction was complete, the reaction solution was cooled on ice to obtain an acetic anhydride solution containing intermediate 4. This solution was used directly in the next reaction. <Step 5> Dichloromethane (45 mL) and intermediate 3 (3.45 g, 6.7 mmol) were added to the acetic anhydride solution containing intermediate 4B obtained in step 4. Triethylamine (6.8 g, 66.8 mmol) was slowly added to the reaction solution while cooling it with ice, and the mixture was stirred at room temperature under a nitrogen stream for 14 hours. After the reaction was complete, ethyl acetate was added to the reaction system to precipitate the target product, which was then filtered off. The resulting yellow-green powder was washed with ethyl acetate and then hexane to obtain A1-10 (5.2 g, yield 86.7%).

[0204] <Example 1-6: Synthesis of Compound A1-60 (Cyanine Compound)> Intermediate 3C was synthesized using the following synthesis method and used as a starting material in place of 2-chlorolepidin in synthesis step 1 of A1-10. In addition to the above changes, A1-60 was synthesized in the same manner as A1-10, except that 3,5-bis(trifluoromethyl)phenylboronic acid in synthesis step 1 of A1-10 was replaced with phenylboronic acid.

[0205] [ka]

[0206] <Synthesis of intermediate 1C> Chlorosulfonic acid (70 mL) was added to a 1000 mL round-bottom flask, and 4-methylcarbostyryl (25.0 g, 157.0 mmol) was slowly added to this solution while cooling it with ice. The reaction solution was heated and stirred at 90°C for 3 hours under a nitrogen stream, and after the reaction was complete, the reaction solution was cooled with ice. The reaction was stopped by slowly pouring the reaction solution onto ice, and the target product was precipitated by adding water. The resulting white powder was filtered off and washed with water, isopropanol, and hexane in that order to obtain intermediate 1C (32.4 g, yield 80.1%).

[0207] <Synthesis of intermediate 2C> Intermediate 1C (16.0 g, 62.1 mmol) and dichloromethane (300 mL) were added to a 1000 mL round-bottom flask, and diisobutylamine (20.1 g, 155.2 mmol) was slowly added while cooling with ice. The reaction solution was stirred at room temperature for 3 hours under a nitrogen stream, and then hexane was added to the flask to precipitate the target product. The resulting white powder was filtered off and washed with hexane to obtain the crude product of intermediate 2C (29.4 g, crude).

[0208] <Synthesis of intermediate 3C> In a 1000 mL round-bottom flask, the crude product of intermediate 2C (29.4 g) and tetrahydrofuran (120 mL) were added, and phosphoryl chloride (19.0 g, 124.2 mmol) was slowly added while cooling with ice. The reaction solution was heated and stirred at 80°C for 1 hour under a nitrogen stream. After the reaction was complete, the reaction solution was cooled with ice, and water was added to stop the reaction. When water was added, a white powder precipitated in the flask. The obtained white powder was filtered off and washed with water, isopropanol, and hexane in that order to obtain intermediate 3C (19.5 g, yield 85.2% (total yield of 2 steps)).

[0209] <Example 1-7: Synthesis of compound A1-61 (cyanine compound)> A1-60 was synthesized in the same manner as A1-60, except that methyl p-toluenesulfonate was replaced with ethyl p-toluenesulfonate in synthesis step 2 of A1-60.

[0210] <Example 1-8: Synthesis of compound A1-63 (cyanine compound)> A1-60 was synthesized in the same manner as A1-60, except that phenylboronic acid was replaced with mesitylboronic acid in synthesis step 1.

[0211] <Example 1-9: Synthesis of Compound A1-79 (Cyanine Compound)> A1-10 was synthesized in the same manner as A1-10, except that 3,5-bis(trifluoromethyl)phenylboronic acid in synthesis step 1 was replaced with 2-thienylboronic acid, and methyl p-toluenesulfonate in synthesis step 2 was replaced with ethyl p-toluenesulfonate.

[0212] <Example 1-10: Synthesis of compound A1-158 (cyanine compound)> The synthesis was carried out in the same manner as A1-63, except that potassium hexafluorophosphate in synthesis step 3 was replaced with sodium tetrafluoroborate.

[0213] <Example 1-11: Synthesis of compound A1-253 (cyanine compound)> The synthesis was carried out in the same manner as A1-63, except that potassium hexafluorophosphate in synthesis step 3 was replaced with potassium bis(trifluoromethanesulfonyl)imide.

[0214] <Example 1-12: Synthesis of compound A1-269 (cyanine compound)> The synthesis was carried out in the same manner as A1-79, except that potassium hexafluorophosphate in synthesis step 3 was replaced with potassium bis(trifluoromethanesulfonyl)imide.

[0215] <Example 1-13: Synthesis of compound A1-272 (cyanine compound)> Intermediate 3D was synthesized using the following synthesis method and used as a starting material in place of 2-chlorolepidin in synthesis step 1 of A1-269. For the subsequent steps, A1-272 was synthesized using the same method as for A1-269.

[0216] [ka]

[0217] <Synthesis of intermediate 1D> 4-butylaniline (55 g, 368.5 mmol), 2,2,6-trimethyl-1,3-dioxin-4-one (55 g, 386.9 mmol), and toluene (80 mL) were added to a 1000 mL round-bottom flask. The reaction solution was heated and stirred at 150 °C under a nitrogen stream for 6 hours. After the reaction was complete, the reaction solution was cooled to room temperature, and the toluene was removed by distillation under reduced pressure. 150 mL of hexane was added to the resulting oily liquid, and the target product was precipitated by cooling with ice. The solid was filtered off, and washed with hexane to obtain intermediate 1D (44.5 g, yield 51.7%).

[0218] <Synthesis of 2D Intermediates> Dilute sulfuric acid (300 mL concentrated sulfuric acid + 150 mL water), prepared in advance, was added to a 1000 mL round-bottom flask and heated to 80°C. Intermediate 1D (44.5 g, 190.7 mmol) was slowly added, and the mixture was heated and stirred at 120°C for 30 minutes. After the reaction was complete, the reaction solution was allowed to return to room temperature, and then slowly added to ice water to stop the reaction and precipitate the target product. The precipitated solid was filtered off and washed with water and then hexane to obtain intermediate 2D (41.2 g, quant.).

[0219] <Synthesis of 3D Intermediate Forms> Intermediate 2D (20.0 g, 92.9 mmol) and dichloromethane (230 mL) were added to a 1000 mL round-bottom flask. Then, while cooling the reaction solution with ice, triethylamine (20.7 g, 204.4 mmol) and trifluoromethanesulfonic anhydride (41.9 g, 148.6 mmol) were slowly added, and the reaction solution was stirred under a nitrogen stream at room temperature for 14 hours. After the reaction was complete, water was added to the reaction solution to stop the reaction. Extraction was performed with dichloromethane, and after removing the dichloromethane under reduced pressure, the solution was purified by flash column chromatography (hexane / ethyl acetate) to obtain intermediate 3D (28.3 g, yield 88.7%).

[0220] <Examples 2-1 to 2-19: Spectral characteristics of near-infrared absorbing dyes in dichloromethane> Near-infrared absorbing dyes were dissolved in dichloromethane, and spectral transmittance curves were measured using a UV-Vis spectrophotometer. The average transmittance at wavelengths of 420-500 nm, the minimum transmittance at 420-500 nm, and the average transmittance at 700-800 nm were calculated when the transmittance at the maximum absorption wavelength was adjusted to 10%. The transmittance at 750 nm was also determined. The results are shown in the table below. Examples 2-1 to 2-13 are examples, while examples 2-14 to 2-19 are comparative examples.

[0221] [Table 9]

[0222] From the above results, it can be seen that dyes A1-1, A1-4, A1-5, A1-7, A1-10, A1-60, A1-61, A1-63, A1-79, A1-158, A1-253, A1-269, and A1-272, by introducing specific substituents at specific positions, maintain high transmittance in the blue band of 420-500 nm while shifting the absorption wavelength to wavelengths longer than 720 nm, compared to dyes C1 and C2 which do not have substituents at these positions. This shows that it is possible to achieve both high transmittance in the blue band and shielding in the near-infrared region of 700-800 nm. Furthermore, comparing A1-5, which has a phenyl substituent, with A1-79, which has a thienyl substituent, A1-79 has a maximum absorption wavelength 14 nm longer, indicating that the thienyl group can shift absorption to longer wavelengths more effectively, thereby improving near-infrared shielding. Furthermore, comparing A1-7 and A1-63, A1-63, which has a sulfonamide group, has its maximum absorption wavelength shifted 21 nm further towards the longer wave compared to A1-7, which does not have a sulfonamide group. Since there is no significant difference in transmittance in the blue band, it can be seen that introducing electron-withdrawing substituents such as sulfonamide groups makes it easier to achieve both near-infrared shielding and high transmittance in the blue band. It should be noted that A1-63, A1-158, and A1-253, and A1-79 and A1-269, are dyes with the same cation species but different anionic species, but the above results show no significant difference in their spectral characteristics. Therefore, it can be said that differences in anionic species do not affect the spectral characteristics. Dyes C3-C6 have excellent shielding properties for near-infrared light, but low transmittance in the blue light band.

[0223] <Examples 3-1 to 3-12: Differences in spectral characteristics of near-infrared absorbing dyes in dichloromethane and resin, and heat resistance tests> In the same manner as in Example 2-1, near-infrared absorbing dyes A1-1, A1-4, A1-5, A1-7, A1-60, A1-61, A1-63, A1-158, A1-253, and A1-269 were each dissolved in dichloromethane so that the transmittance at the maximum absorption wavelength was 10%, and the spectral transmittance curves were measured using a UV-Vis spectrophotometer. The shortest wavelength (T80(A)) at which the transmittance was 80% in the wavelength range above 500 nm was measured. short) and the longest wavelength (T80(A)) in the wavelength range of 500nm or more where the transmittance is 80%. long ) was sought. Furthermore, transparent resin solutions (1) and (2) below were prepared, and near-infrared absorbing dyes A1-1, A1-4, A1-5, A1-7, A1-60, A1-61, A1-63, A1-158, A1-253, and A1-269 were added to the transparent resin solutions at a concentration of 7.5 parts by mass per 100 parts by mass of resin, and the mixture was stirred and dissolved at 50°C for 2 hours to obtain a coating solution. The obtained coating solution was applied to SCHOTT's D263 glass (thickness 0.2 mm) by spin coating, and coating films were formed with a film thickness of approximately 1.0 μm. (1) Polyimide resin solution A polyimide resin solution with a resin concentration of 8.5% by mass was prepared by dissolving polyimide resin (product name "C3G30G" manufactured by Mitsubishi Gas Chemical Company, Inc., refractive index 1.59) in a γ-butyrolactone (GBL):cyclohexanone ratio of 1:1 (by mass). (2) Polyester resin solution A polyester resin solution with a resin concentration of 15% by mass was prepared by dissolving polyester resin (Osaka Gas Chemical Co., Ltd.'s "B-OKP2" (product name), refractive index 1.63) in cyclohexanone. The spectral transmittance curves of the obtained coating film were measured in the wavelength range of 350 to 1200 nm using an ultraviolet-visible spectrophotometer. From these measurement results, the maximum absorption wavelength λ in the resin was determined. max When the internal transmittance at (pA) is set to 10%, the shortest wavelength (T80(pA)) in the wavelength range of 500 nm or more at which the internal transmittance is 80% is... short ), the longest wavelength (T80(pA)) in the wavelength range of 500nm or more at which the internal transmittance is 80% long The values ​​were determined for each coating film. From these results, in each coating film, |T80(A) short -T80(pA) short |,|T80(A) long -T80(pA) long | was calculated. Furthermore, the maximum absorption wavelength λ in dichloromethane max(A) Transmittance and maximum absorption wavelength λ in the resin max When the internal transmittance at (pA) was adjusted to 10%, the average absolute value of the difference between the transmittance in the dichloromethane spectral transmittance curve at wavelengths of 420-500 nm and the internal transmittance of the coated film spectral transmittance curve at wavelengths of 420-500 nm was also calculated. The results are shown in the table below. Furthermore, to avoid the influence of reflections at the air interface and glass interface, the spectral characteristics of the coating film were evaluated using internal transmittance. Internal transmittance = {Measured transmittance / (100 - Measured reflectance)} × 100

[0224] Furthermore, the coating films obtained above were subjected to heat resistance tests to evaluate their heat resistance. In the heat resistance test, the glass substrate was placed on a hot plate with the side where the absorption layer was formed facing upwards and heated at 200°C for 5 minutes. For each coating film, the spectral transmittance curves before and after heating were measured using a UV-Vis spectrophotometer, and the absorbance at the maximum absorption wavelength was determined. The dye retention rate before and after heating was then calculated using the following formula. Pigment retention rate (%) = (Absorbance at the maximum absorption wavelength after heating) / (Absorbance at the maximum absorption wavelength before heating) × 100 The results are shown in the table below. The evaluation criteria for heat resistance are as follows. A: Dye residual rate 80% or more B: Pigment retention rate less than 80%

[0225] Examples 3-1 to 3-12 are examples of actual cases.

[0226] [Table 10]

[0227] The above spectral characteristics results indicate that, in both cases using polyimide resin and polyester resin, the change in the spectral characteristics of the dye between the resin and dichloromethane is small. That is, |T80(A) short -T80(pA) short |≦60nm, |T80(A) long-T80(pA) long It can be seen that by combining the dye with a resin that satisfies the relationship that the average absolute value of the difference between the transmittance in dichloromethane and the internal transmittance in the resin for light with wavelengths of ≤45nm and 420-500nm is 8% / nm or less, the desired spectral characteristics can be obtained without impairing the spectral characteristics of the dye. Furthermore, the results of the heat resistance evaluation show that polyimide resin has excellent heat resistance.

[0228] <Examples 4-1 to 4-20: Spectral properties of near-infrared absorbing dyes in resin> Near-infrared absorbing dyes A1-1, A1-4, A1-5, A1-7, A1-60, A1-61, A1-63, A1-158, A1-253, A1-269, and C1-C6 were mixed in a polyimide resin solution prepared in the same manner as in Example 3-1, at the concentrations listed in the table below. The mixtures were then stirred and dissolved at 50°C for 2 hours to obtain a polyimide resin coating solution. The obtained coating solution was applied to SCHOTT D263 glass (0.2 mm thick) by spin coating to form a coating film with a thickness of 1.0 μm. (Only in Example 4-10 was a coating film with a thickness of 2 μm formed.) Near-infrared absorbing dyes A1-5, A1-7, C4, and C5 were mixed in a polyester resin solution prepared in the same manner as in Example 3-1 above, at the concentrations shown in the table below, and stirred and dissolved at 50°C for 2 hours to obtain a polyester resin coating solution. The obtained coating solution was applied to SCHOTT's D263 glass (thickness 0.2 mm) by spin coating to form a coating film with a thickness of 1 μm. For each obtained coating film, the spectral transmittance curve in the wavelength range of 350 to 1200 nm was measured using a UV-Vis spectrophotometer. From these measurement results, the maximum absorption wavelength λ of the near-infrared absorbing dye in the resin was determined. max (pA), the above λ max The average and minimum internal transmittances at 420-500 nm, the average internal transmittance at 700-800 nm, and the internal transmittance at 750 nm were calculated, assuming an internal transmittance of 10% at (pA). The results are shown in the table below. Note that the spectral characteristics shown in the table below were evaluated using internal transmittance to avoid the influence of reflection at the air interface and glass interface. Examples 4-1 to 4-10 and 4-17 to 4-18 are examples, while examples 4-11 to 4-16 and 4-19 to 4-20 are comparative examples.

[0229] [Table 11]

[0230] From the results above, it can be seen that dyes A1-1, A1-4, A1-5, A1-7, A1-60, A1-61, A1-63, A1-158, A1-253, and A1-269 all exhibit high transmittance in the blue band of 420-500 nm and high shielding in the near-infrared band of 700-800 nm even in resin, thus achieving a balance between the two. Furthermore, similar to the results in dichloromethane, dyes A1-60, A1-61, A1-63, A1-158, and A1-253, which have sulfonamide groups, show a further shift in their maximum absorption wavelength to the longer wavelength side compared to dyes A1-4, A1-5, and A1-7, which do not have sulfonamide groups. However, no significant decrease in transmittance in the blue band is observed. This indicates that introducing electron-withdrawing substituents such as sulfonamide groups makes it easier to achieve both near-infrared shielding and high transmittance in the blue band even in resins. Furthermore, comparing dye A1-5, which has a phenyl group substituent, with dye A1-269, which has a thienyl group substituent, the results are similar to those in dichloromethane. Dye A1-269 has a maximum absorption wavelength 14 nm longer, indicating that the thienyl group can shift absorption to longer wavelengths more effectively, thus improving near-infrared shielding even in resins. On the other hand, dyes C1 and C2 showed insufficient shielding in the near-infrared region, while dyes C3 to C6 exhibited low transmittance in the blue band.

[0231] <Examples 5-1 to 5-14: Spectral characteristics of resin films> Near-infrared absorbing dyes A1-1, A1-5, A1-7, A1-60, A1-61, A1-63, A1-158, A1-253, A1-269, C1-C3, C5, and C6, along with near-infrared absorbing dyes B2-1 and B2-2, were mixed in the polyimide resin solution prepared in the same manner as in Example 3-1 above, at the concentrations shown in the table below. The mixtures were then stirred and dissolved at 50°C for 2 hours to obtain a coating solution. The obtained coating solution was applied to SCHOTT's D263 glass (thickness 0.2 mm) by spin coating to form a resin film with a thickness of 1.0 μm. The spectral transmittance curves of the obtained resin film were measured in the wavelength range of 350 to 1200 nm using an ultraviolet-visible spectrophotometer. From the obtained spectral characteristics data, the shortest wavelength at which the internal transmittance was 50% in the wavelength range of 500 nm and above, the average and minimum internal transmittance in the wavelength range of 420 to 500 nm, the average internal transmittance in the wavelength range of 700 to 800 nm, the average internal transmittance in the wavelength range of 700 to 750 nm, and the internal transmittance at a wavelength of 750 nm were calculated. The results are shown in the table below. Note that the spectral characteristics shown in the table below were evaluated using internal transmittance to avoid the influence of reflection at the air interface and glass interface. Examples 5-1 to 5-9 are examples, while examples 5-10 to 5-14 are comparative examples.

[0232] [Table 12]

[0233] Each of the above resin films is designed with adjusted dye concentration so that the wavelength at which the internal transmittance is 50% is around 650 nm. From the above results, it can be seen that the resin films of Examples 5-1 to 5-9, each containing the specific near-infrared absorbing dyes A1-1, A1-5, A1-7, A1-60, A1-61, A1-63, A1-158, A1-253, and A1-269, respectively, were able to achieve both near-infrared shielding and high transmittance in the blue band. In particular, the resin films of Examples 5-4 to 5-8, which use dyes A1-60, A1-61, A1-63, A1-158, and A1-253 having sulfonamide groups, and the resin film of Example 5-9, which uses dye A1-269 having a thienyl group, have lower average transmittance values ​​in the 700-800 nm range and lower internal transmittance values ​​at 750 nm, indicating superior near-infrared shielding. Therefore, by having electron-withdrawing substituents such as sulfonamide groups or electron-rich heteroaryl groups such as thienyl groups, it becomes possible to achieve a high level of both high transmittance in the blue band and near-infrared shielding. On the other hand, the resin films of Examples 5-10 to 5-11, which contain near-infrared absorbing dyes C1 and C2 respectively, showed high transmittance in the blue band from 420 to 500 nm, but insufficient shielding in the near-infrared region from 700 to 800 nm. The resin films of Examples 5-12 to 5-14, which contain near-infrared absorbing dyes C3, C5, and C6 respectively, showed good shielding in the near-infrared region, but low transmittance in the blue band.

[0234] <Examples 6-1 to 6-14: Spectral characteristics of optical filters> [Dielectric multilayer film (reflective film)] A dielectric multilayer film with a thickness of 6 μm was formed on the surface of a SCHOTT D263 glass substrate (thickness 0.2 mm) by alternately layering TiO2 and SiO2 films using vapor deposition. The number of layers of dielectric multilayer film, the thickness of the TiO2 film, and the thickness of the SiO2 film were used as parameters in simulations, and the design was created to satisfy the following conditions in the spectral transmittance curves at incident angles of 0° and 30°. 1. In the spectral transmittance curve at an incident angle of 0°, the wavelength in the wavelength range of 650-800 nm where the transmittance is 50% (IR) 50 ) has 2. In the spectral transmittance curve at an incident angle of 0°, the wavelength in the 385-425 nm range is such that the transmittance is 50% (UV 50 ) has 3. In the spectral transmittance curves at incident angles of 0° and 30°, the average transmittance of light in the wavelength range of 435-650nm is 88% or higher in both cases. 4. In the spectral transmittance curves at incident angles of 0° and 30°, the average transmittance of light in the wavelength range of 750-1000 nm is 10% or less in both cases. The spectral characteristics of the dielectric multilayer film designed based on the above are shown in the table below. This dielectric multilayer film was used as the reflective layer of an optical filter.

[0235] [Table 13]

[0236] [Optical filter] On the surface opposite to the surface on which the above-mentioned dielectric multilayer film (reflective layer) was laminated, the resin films of Examples 5-1 to 5-13 were laminated. Further, a dielectric multilayer film consisting of alternating layers of TiO2 and SiO2 films was formed on the resin film surface by vapor deposition to create an anti-reflective film. The configuration of the anti-reflective film was also designed by simulating the number of layers of dielectric multilayer film, the thickness of the TiO2 film, and the thickness of the SiO2 film as parameters to obtain the desired spectral characteristics. Based on the above, each optical filter was obtained. The spectral characteristics of each optical filter are shown in the table below. Furthermore, the spectral transmittance curves of the optical filters for Examples 6-2, 6-6, 6-10, 6-12, and 6-14 are shown in Figures 5-7. Examples 6-1 to 6-9 are examples, while examples 6-10 to 6-14 are comparative examples.

[0237] [Table 14]

[0238] From the above results, it can be seen that the optical filters of Examples 6-1 to 6-9, which are equipped with resin films of Examples 5-1 to 5-9 containing the specific near-infrared absorbing dyes A1-1, A1-5, A1-7, A1-60, A1-61, A1-63, A1-158, A1-253, and A1-269 respectively, were able to achieve both shielding in the near-infrared region and high transmittance in the blue band. On the other hand, the optical filters of Examples 6-10 to 6-11, which were equipped with resin films of Examples 5-10 to 5-11 containing near-infrared absorbing dyes C1 and C2 respectively, showed insufficient shielding in the near-infrared region of 700 to 800 nm. The optical filters of Examples 6-12 to 6-14, which were equipped with resin films of Examples 5-12 to 5-14 containing near-infrared absorbing dyes C3, C5, and C6 respectively, showed low minimum transmittance in the 420 to 500 nm range and insufficient transmittance in the blue band.

[0239] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. This application is based on Japanese Patent Application No. 2021-030728, filed on 26 February 2021, the contents of which are incorporated herein by reference. [Industrial applicability]

[0240] The optical filter of the present invention exhibits excellent transmittance of visible light, including the blue band, and high shielding performance, particularly in the 700-800 nm region within the near-infrared spectrum. It is useful in applications such as information acquisition devices, including cameras and sensors for transport aircraft, where performance has been steadily improving in recent years. [Explanation of symbols]

[0241] 1A, 1B, 1C, 1D... Optical filters, 10... Substrate, 11... Support, 12... Resin film, 30... Dielectric multilayer film

Claims

1. The device comprises a substrate and a dielectric multilayer film laminated as the outermost layer on at least one main surface side of the substrate. The substrate is an optical filter having a resin film containing a near-infrared absorbing dye and a resin, The near-infrared absorbing dye exhibits maximum absorption wavelength λ in the 720-770 nm wavelength range in dichloromethane. ｍａｘ An optical filter having (A) and containing a near-infrared absorbing dye A represented by the following formula (A). 【Chemistry 1】 [The meanings of the symbols in the above formula are as follows: R １ Each of these independently represents an alkyl group having 1 to 12 carbon atoms that may have substituents, an alkenyl group having 1 to 12 carbon atoms that may have substituents, a cycloalkyl group having 3 to 12 carbon atoms that may have substituents, an aryl group having 6 to 12 carbon atoms that may have substituents, or an alaryl group having 7 to 13 carbon atoms that may have substituents. R ２ Each of these is independently a secondary alkyl group having 3 to 12 carbon atoms, a tertiary alkyl group having 4 to 12 carbon atoms, a cycloalkyl group having 3 to 13 carbon atoms which may have substituents, a heteroaryl group having 3 to 12 carbon atoms which may have substituents, or -SiR １０１ R １０２ R １０３ This indicates R １０１ ~R １０３ Each of these independently represents an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms, which may have substituents. R ３ to R ７ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms which may have a substituent, an alkoxy group having 1 to 12 carbon atoms which may have a substituent, an aryl group having 6 to 12 carbon atoms which may have a substituent, an aralkyl group having 7 to 13 carbon atoms which may have a substituent, -NR １０４ R １０５ , -C(=O)R １０６ , -C(=O)NR １０７ R １０８ , -SO ２ R １０９ or -SO ２ NR １１０ R １１１ is shown. Here, R １０４ , R １０５ each independently represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms which may have a substituent, an aryl group having 6 to 12 carbon atoms which may have a substituent, or a carbonyl group having 1 to 12 carbon atoms which may have a substituent. R １０６ is an alkyl group having 1 to 20 carbon atoms which may have a substituent. R １０７ to R １１１ each independently represents an alkyl group having 1 to 12 carbon atoms which may have a substituent. R １１ ~R １３ Each of these independently consists of a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms which may have substituents, an aryl group having 6 to 12 carbon atoms which may have substituents, or -NR １１２ R １１３ This shows R １１２ , R １１３ Each of these is independently an alkyl group having 1 to 12 carbon atoms which may have substituents, an aryl group having 6 to 12 carbon atoms which may have substituents, and a carbonyl group having 1 to 12 carbon atoms which may have substituents. X － This indicates a monovalent anion species.

2. In the near-infrared absorbing dye A, R ２ The optical filter according to claim 1, wherein is a tertiary alkyl group having 4 to 12 carbon atoms, or a heteroaryl group having 3 to 12 carbon atoms which may have substituents.

3. In the near-infrared absorbing dye A, R ２ The optical filter according to claim 1 or 2, wherein is a tert-butyl group, a 1,1-dimethylpropyl group, a thienyl group, or a furyl group.

4. In the near-infrared absorbing dye A, R １１ ~R １３ The optical filter according to any one of claims 1 to 3, wherein is a hydrogen atom.

5. The optical filter according to any one of claims 1 to 4, wherein the near-infrared absorbing dye A satisfies the following spectral characteristics (ii-1) and (ii-2) in the spectral transmittance curve of the coating film obtained by dissolving or dispersing the near-infrared absorbing dye A in the resin. (ii-1) The maximum absorption wavelength λ of the near-infrared absorbing dye A in dichloromethane ｍａｘ When the transmittance of (A) is set to 10%, the shortest wavelength in the wavelength range of 500 nm or more at which the transmittance becomes 80% is T80(A). ｓｈｏｒｔ The longest wavelength is T80(A) ｌｏｎｇ year, The maximum absorption wavelength λ of the near-infrared absorbing dye A in the resin ｍａｘ When the internal transmittance of (pA) is adjusted to 10%, the shortest wavelength in the wavelength range of 500 nm or more at which the internal transmittance becomes 80% is T80(pA). ｓｈｏｒｔ The longest wavelength is set to T80 (pA). ｌｏｎｇ When this is the case, all of the following relationships are satisfied. |T80(A) ｓｈｏｒｔ -T80(0A) ｓｈｏｒｔ |≦60nm |T80(A) ｌｏｎｇ -T80(0A) ｌｏｎｇ |≦45nm (ii-2) Maximum absorption wavelength λ ｍａｘ Transmittance and maximum absorption wavelength λ in (A) ｍａｘ When the internal transmittance at (pA) is adjusted to 10%, the average absolute value of the difference between the transmittance in dichloromethane at wavelengths of 420-500 nm and the internal transmittance of the spectral transmittance curve in the resin at wavelengths of 420-500 nm is 8% / nm or less.

6. The optical filter according to any one of claims 1 to 5, wherein the resin is a polyimide resin or a polyester resin.

7. The near-infrared absorbing dye A has the maximum absorption wavelength λ ｍａｘ The optical filter according to any one of claims 1 to 6, wherein the spectral transmittance curve measured by dissolving the near-infrared absorbing dye A in dichloromethane such that the transmittance in (A) is 10% satisfies all of the following spectral characteristics (i-1) to (i-4). (i-1) Average transmittance of 98% or more at wavelengths of 420-500 nm (i-2) Minimum transmittance of 97% or more at wavelengths of 420-500 nm (i-3) Average transmittance of 65% or less at wavelengths of 700-800 nm (i-4) Transmittance at a wavelength of 750 nm is 80% or less.

8. The near-infrared absorbing dye A, in the spectral transmittance curve of the coating film obtained by dissolving or dispersing the near-infrared absorbing dye A in the resin, has the maximum absorption wavelength λ of the near-infrared absorbing dye A in the resin. ｍａｘ An optical filter according to any one of claims 1 to 7, which satisfies all of the following spectral characteristics (iii-1) to (iii-3) when the internal transmittance (pA) is adjusted to 10%. (iii-1) The average internal transmittance at wavelengths of 420-500 nm is 95% or higher, and the minimum internal transmittance at wavelengths of 420-500 nm is 93% or higher. (iii-2) Average internal transmittance of 50% or less at wavelengths of 700-800 nm (iii-3) Internal transmittance at a wavelength of 750 nm is 30% or less.

9. The optical filter according to any one of claims 1 to 8, further comprising a near-infrared absorbing dye B that satisfies the following spectral characteristics (iv-1) and (iv-2). (iv-1) Maximum absorption wavelength λ in the 670-730 nm wavelength range in dichloromethane ｍａｘ (B) (iv-2) Maximum absorption wavelength λ of the near-infrared absorbing dye B ｍａｘ (B) and the maximum absorption wavelength λ of the near-infrared absorbing dye A. ｍａｘ The following relationship holds between (A) and (A): l ｍａｘ (B)<l ｍａｘ (A)

10. The optical filter according to claim 9, wherein the near-infrared absorbing dye B is a squarylium dye.

11. The optical filter according to any one of claims 1 to 10, wherein the resin film satisfies all of the following spectral characteristics (v-1) to (v-6). (v-1) In the region of wavelengths above 500 nm, the shortest wavelength at which the internal transmittance is 50% is in the range of 620 to 680 nm. (v-2) The average internal transmittance in the wavelength range of 420 to 500 nm is 94% or higher, and the minimum internal transmittance is 85% or higher. (v-3) The average internal transmittance in the wavelength range of 700-800 nm is 50% or less. (v-4) The average internal transmittance in the wavelength range of 700-750 nm is 8% or less. (v-5) The internal transmittance at 750 nm is 30% or less.

12. The optical filter according to any one of claims 1 to 11, wherein the optical filter satisfies all of the following spectral characteristics (vii-1) to (vii-6). (vii-1) The average transmittance at wavelengths of 420-500 nm at an incident angle of 0° is 90% or higher, and the minimum transmittance is 83% or higher. (vii-2) The average transmittance of wavelengths 600-700 nm at an incident angle of 0° is 25% or more. (vii-3) The average transmittance at wavelengths of 710-1100 nm at an incident angle of 0° is 2% or less. (vii-4) The average transmittance at wavelengths of 700-800 nm at an incident angle of 0° is 3% or less. (vii-5) The maximum transmittance at wavelengths of 700-800 nm at an incident angle of 0° is 5% or less. (vii-6) The average value of the absolute difference between the transmittance at wavelengths of 600-700 nm at an incident angle of 0° and the transmittance at wavelengths of 600-700 nm at an incident angle of 30° is 7% / nm or less.

13. The optical filter according to any one of claims 1 to 12, wherein the substrate comprises a support and the resin film, the resin film is laminated on at least one main surface of the support, and the support is transparent glass or absorbent glass.

14. In the near-infrared absorbing dye A, R １ Each of these independently represents an alkyl group having 1 to 12 carbon atoms that may have substituents, an alkenyl group having 1 to 12 carbon atoms that may have substituents, a cycloalkyl group having 3 to 12 carbon atoms that may have substituents, or an alaryl group having 7 to 13 carbon atoms that may have substituents. R ５ Each of these independently comprises a halogen atom, an alkyl group having 1 to 12 carbon atoms which may have substituents, an alkoxy group having 1 to 12 carbon atoms which may have substituents, an aryl group having 6 to 12 carbon atoms which may have substituents, an aryl group having 7 to 13 carbon atoms which may have substituents, and -NR １０４ R １０５ , -C(=O)R １０６ , -C(=O)NR １０７ R １０８ , -SO ２ R １０９ or -SO ２ NR １１０ R １１１ An optical filter according to any one of claims 1 to 13, which shows the following.

15. An imaging apparatus comprising an optical filter according to any one of claims 1 to 14.

16. The compound represented by the following formula (A1). 【Chemistry 2】 [The meanings of the symbols in the above formula are as follows: R １ Each of these independently represents an alkyl group having 1 to 12 carbon atoms that may have substituents, an alkenyl group having 1 to 12 carbon atoms that may have substituents, a cycloalkyl group having 3 to 12 carbon atoms that may have substituents, an aryl group having 6 to 12 carbon atoms that may have substituents, or an alaryl group having 7 to 13 carbon atoms that may have substituents. R ２１ Each of these is independently a tertiary alkyl group having 4 to 12 carbon atoms, or a heteroaryl group having 3 to 12 carbon atoms, which may have substituents. R ４ ~R ７ Each of these independently consists of a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms which may have substituents, an alkoxy group having 1 to 12 carbon atoms which may have substituents, an aryl group having 6 to 12 carbon atoms which may have substituents, an aryl group having 7 to 13 carbon atoms which may have substituents, and -NR １０４ R １０５ , -C(=O)R １０６ , -C(=O)NR １０７ R １０８ , -SO ２ R １０９ or -SO ２ NR １１０ R １１１ This shows R １０４ , R １０５ Each of these is independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms which may have substituents, an aryl group having 6 to 12 carbon atoms which may have substituents, and a carbonyl group having 1 to 12 carbon atoms which may have substituents. １０６ R is an alkyl group having 1 to 20 carbon atoms, which may have substituents. １０７ ~R １１１ Each of these is independently an alkyl group having 1 to 12 carbon atoms, which may have substituents. X － This indicates a monovalent anion species.

17. In the above formula (A1), R １ Each of these independently represents an alkyl group having 1 to 12 carbon atoms that may have substituents, an alkenyl group having 1 to 12 carbon atoms that may have substituents, a cycloalkyl group having 3 to 12 carbon atoms that may have substituents, or an alaryl group having 7 to 13 carbon atoms that may have substituents. R ５ is each independently a halogen atom, an alkyl group having 1 to 12 carbon atoms which may have a substituent, an alkoxy group having 1 to 12 carbon atoms which may have a substituent, an aryl group having 6 to 12 carbon atoms which may have a substituent, an aralkyl group having 7 to 13 carbon atoms which may have a substituent, -NR １０４ R １０５ , -C(=O)R １０６ , -C(=O)NR １０７ R １０８ , -SO ２ R １０９ or -SO ２ NR １１０ R １１１ The compound according to claim 16, which represents

Images