Optical Filters

Abstract

The present invention relates to an optical filter which is provided with a base material and a dielectric multilayer film that is superposed, as an outermost layer, on at least one main surface of the base material, wherein: the base material comprises a resin film that contains a resin and a near-infrared absorbing dye (A); and the dye (A) satisfies a specific spectral characteristic in the spectral transmittance curve of a coating film that is obtained by applying the dye (A), which has been dissolved in the resin, onto an alkali glass plate.

Description

[Technical field]

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

[0002] In order to reproduce color tones well and obtain clear images, imaging devices using solid-state imaging elements use optical filters that transmit light in the visible range (hereinafter also referred to as "visible light") and block light in the near-infrared wavelength range (hereinafter also referred to as "near-infrared light").

[0003] Such optical filters include various types, such as a reflective filter in which dielectric thin films with different refractive indices are alternately laminated (dielectric multilayer film) on one or both sides of a transparent substrate, and light interference is utilized to reflect light to be blocked. Optical filters having a dielectric multilayer film have problems such as a change in the spectral transmittance curve depending on the incident angle, light leakage in which near-infrared light that should have a high reflectance at a high incident angle becomes highly transmittance, and noise due to near-infrared light reflected by the dielectric multilayer film, because the optical film thickness of the dielectric multilayer film changes depending on the incident angle of light. When such a filter is used, the spectral sensitivity of the solid-state imaging element may be affected by the incident angle. Therefore, there has been a demand for an optical filter that blocks near-infrared light without affecting the transmittance of visible light and without depending on the incident angle.

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

[0005] [Patent Document 1] International Publication No. 2019 / 168090 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the optical filter described in Patent Document 1 has room for improvement in terms of transmittance in the visible light region. Therefore, an object of the present invention is to provide an optical filter that maintains high transmittance of visible light, particularly blue light, while suppressing a decrease in the near-infrared light shielding ability at high incident angles, such as light leakage, while blocking near-infrared light. [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 an outermost layer on at least one main surface side of the substrate, the substrate includes a resin film containing a dye (A) that is a near-infrared absorbing dye and a resin, The dye (A) is an optical filter which satisfies all of the following spectral characteristics (i-1) to (i-4) in a spectral transmittance curve of a coating film formed by dissolving the dye (A) in the resin and coating the coating film on an alkali glass plate. (i-1) When the shortest wavelength at which the transmittance is 30% in the wavelength range of 600 to 800 nm is IR30a, and the longest wavelength at which the transmittance is 30% in the wavelength range of 700 to 1200 nm is IR30b, The absolute difference between IR30a and IR30b is 170nm or more (i-2) When the shortest wavelength at which the transmittance is 50% in the wavelength range of 600 to 800 nm is IR50a, and the longest wavelength at which the transmittance is 50% in the wavelength range of 700 to 1200 nm is IR50b, The absolute difference between IR50a and IR50b is 200nm or more (i-3) Absorbance A at a wavelength of 440 nm 440 and absorbance A at a wavelength of 700 nm 700 Relationship with A 440 / A 700 ≦0.14 (i-4) Absorbance A at a wavelength of 490 nm 490 and absorbance A at a wavelength of 700 nm 700 Relationship with A 490 / A 700≦0.10 Effect of the Invention

[0008] According to the present invention, it is possible to provide an optical filter that has high transmittance for visible light and high blocking ability for near-infrared light, and in particular, has high transmittance for blue light, and suppresses a decrease in blocking ability for near-infrared light at a high angle of incidence. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view illustrating an example of an optical filter according to an embodiment. [Diagram 2] FIG. 2 is a cross-sectional view illustrating a schematic configuration of another example of the optical filter according to the embodiment. [Diagram 3] FIG. 3 is a cross-sectional view illustrating a schematic configuration of another example of the optical filter according to the embodiment. [Figure 4] FIG. 4 is a cross-sectional view illustrating a schematic configuration of another example of the optical filter according to the embodiment. [Diagram 5] FIG. 5 is a diagram showing the spectral transmittance curve of Compound 6 in dichloromethane and in a cycloolefin resin. [Figure 6] FIG. 6 is a diagram showing the spectral transmittance curve of the optical filter of Example 3-1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0011] In this specification, the internal transmittance is the transmittance obtained by subtracting the influence of interface reflection from the actually measured transmittance, which is expressed by the formula {actually measured transmittance / (100-reflectance)}×100. In this specification, the transmittance of a substrate and the transmittance of a resin film including a case where a dye is contained in the resin are all "internal transmittance" even when they are described as "transmittance". On the other hand, the transmittance measured by dissolving a dye in a solvent such as dichloromethane and the transmittance of an optical filter having a dielectric multilayer film are actually measured transmittances.

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

[0013] In this specification, for example, a transmittance of 90% or more in a specific wavelength range means that the transmittance is not below 90% in the entire wavelength range, i.e., the minimum transmittance is 90% or more in the wavelength range. Similarly, for example, a transmittance of 1% or less in a specific wavelength range means that the transmittance is not more than 1% in the entire wavelength range, i.e., the maximum transmittance is 1% or less in the wavelength range. The same applies to internal transmittance. The average transmittance and average internal transmittance in a specific wavelength range are the arithmetic mean of the transmittance and internal transmittance per 1 nm in the wavelength range. In this specification, the term "to" indicating a numerical range includes the upper and lower limits.

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

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

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

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

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

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

[0020] <NIR dye (A)> The dye (A) is a near-infrared absorbing (NIR) dye. By the substrate containing a dye that absorbs near-infrared rays, a decrease in the spectral characteristics of the dielectric multilayer film at a high incident angle, for example, light leakage or generation of noise in the near-infrared region, can be suppressed by the absorption characteristics of the substrate.

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

[0022] The dye (A) exhibits specific spectral characteristics in the resin used for the substrate. Specifically, the coating film formed by dissolving the dye (A) in a resin and coating the resulting solution on an alkali glass plate satisfies all of the following spectral characteristics (i-1) to (i-4).

[0023] (i-1) When the shortest wavelength at which the transmittance is 30% in the wavelength range of 600 to 800 nm is IR30a, and the longest wavelength at which the transmittance is 30% in the wavelength range of 700 to 1200 nm is IR30b, The absolute difference between IR30a and IR30b is 170nm or more (i-2) When the shortest wavelength at which the transmittance is 50% in the wavelength range of 600 to 800 nm is IR50a, and the longest wavelength at which the transmittance is 50% in the wavelength range of 700 to 1200 nm is IR50b, The absolute difference between IR50a and IR50b is 200nm or more (i-3) Absorbance A at a wavelength of 440 nm 440 and absorbance A at a wavelength of 700 nm 700 Relationship with A 440 / A 700 ≦0.14 (i-4) Absorbance A at a wavelength of 490 nm 490 and absorbance A at a wavelength of 700 nm 700 Relationship with A 490 / A 700 ≦0.10

[0024] The present filter, which contains the dye (A) exhibiting the above-mentioned spectral properties (i-1) to (i-4) in the resin, is an optical filter that maintains good transmittance of visible light, particularly blue light, while suppressing the decrease in the near-infrared light blocking ability at a high incidence angle.

[0025] By satisfying the spectral characteristics (i-1) and (i-2), it means that near-infrared light can be absorbed broadly in a wide wavelength range. This makes it possible to efficiently prevent light leakage in the wavelength band of 750 to 900 nm, where the dielectric multilayer film is not able to completely block light at high angles of incidence and light leakage is likely to occur. Furthermore, since the dye (A) itself has broad absorption characteristics in the resin, it is possible to efficiently block the near-infrared region using only the dye (A) while maintaining a good transmittance in the visible light region without combining multiple types of NIR dyes. When multiple types of NIR dyes are combined, the near-infrared region can be widely blocked, but the transmittance in the visible light region also tends to decrease at the same time, but this can be avoided by using the dye (A) in the present invention.

[0026] The absolute value of the spectral characteristic (i-1) is preferably 190 nm or more, more preferably 210 nm or more, and particularly preferably 230 nm or more. Since a wider absorption width is more preferable, the upper limit is not limited, but it is usually 270 nm or less. The absolute value of the spectral characteristic (i-2) is preferably 210 nm or more, more preferably 230 nm or more. Since a wider absorption width is more preferable, the upper limit is not limited, but is usually 270 nm or less.

[0027] Satisfying the spectral characteristics (i-3) and (i-4) means that the transmittance of blue light is excellent. The spectral characteristics (i-3) are preferably A 440 / A 700 ≦0.11, more preferably A 440 / A 700 ≦0.10. The spectral characteristics (i-4) are preferably A 490 / A 700 ≦0.08, more preferably A 490 / A 700 ≦0.07.

[0028] It is preferred that the dye (A) further exhibits the following spectroscopic property (i-5) in the resin. That is, it is preferred that the coating film containing the dye (A) and the resin satisfies the following spectroscopic property (i-5). (i-5) the product of the content of the dye (A) in the coating film and the thickness of the coating film is 20 (mass% μm) or less By satisfying the spectral characteristic (i-5), the content of the NIR dye (A) can absorb near-infrared light in a wide wavelength range. The spectral characteristic (i-5) is preferably 15 (mass% μm) or less, more preferably 12 (mass% μm) or less, and also preferably 1 (mass% μm) or more.

[0029] It is preferred that the dye (A) further exhibits the following spectroscopic property (i-6) in the resin. That is, it is preferred that the coating film containing the dye (A) and the resin satisfies the following spectroscopic property (i-6). (i-6) A at wavelength 570 nm 570 and absorbance A at a wavelength of 700 nm 700 Relationship with A 570 / A 700 ≦0.10 By satisfying the spectral characteristic (i-6), it is meant that the transmittance of green light is excellent. The spectral characteristic (i-6) is preferably A 570 / A 700 ≦0.05, more preferably A 570 / A 700 ≦0.03.

[0030] It is preferable that the dye (A) further exhibits the following spectroscopic property (i-7) in the resin. That is, it is preferable that the coating film containing the dye (A) and the resin satisfies the following spectroscopic property (i-7). (i-7) Absorbance A at a wavelength of 630 nm 630 and absorbance A at a wavelength of 700 nm 700 Relationship with A 630 / A 700 ≦0.12 By satisfying the spectral characteristic (i-7), it is meant that the transmittance of red light is excellent. The spectral characteristic (i-7) is preferably A 630 / A 700 ≦0.11, more preferably A 630 / A 700 ≦0.08.

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

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

[0033] The dye (A) is preferably a cyanine dye, more preferably an external salt type cyanine dye having an anionic group outside the molecule. The external salt type cyanine dye forms an association state in the resin and tends to broaden the near infrared absorption band, so that it tends to satisfy the above-mentioned spectral characteristics (i-1) to (i-8), (ii-1) and (ii-2).

[0034] Specifically, the cyanine dye is preferably a compound represented by the following formula (A1) or a compound represented by the following formula (A2).

[0035] [ka]

[0036] In the formulae (A1) and (A2), the symbols are as follows: R 101 ~R 109 and R 121 ~R 131 R each independently represents a hydrogen atom, a halogen atom, an alkyl group or alkoxy group having 1 to 15 carbon atoms which may have a substituent, or an aryl group having 5 to 20 carbon atoms. 110 ~ 114 and R 132 ~ 136 each independently represents a hydrogen atom, a halogen atom, or an alkyl or alkoxy group having 1 to 15 carbon atoms. X - indicates a monovalent anion. n1 and n2 each independently represent 0 or 1. -(CH 2 ) n1 Carbocycles containing - and -(CH 2 ) n2 A hydrogen atom bonded to a carbon ring containing - may be substituted with a halogen atom, an alkyl group having 1 to 15 carbon atoms which may have a substituent, or an aryl group having 5 to 20 carbon atoms.

[0037] In formula (A1) and formula (A2), R 102 ~R 105 , R 108 , R 109 , R 122 ~R 127 , R 130 and R 131 are each independently preferably a hydrogen atom, an alkyl or alkoxy group having 1 to 15 carbon atoms, or an aryl group having 5 to 20 carbon atoms, and more preferably a hydrogen atom from the viewpoint of obtaining a high visible light transmittance.

[0038] In formula (A1) and formula (A2), R 110 ~R 114 and R 132 ~R 136 are each independently preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms, and more preferably a hydrogen atom from the viewpoint of obtaining a high visible light transmittance.

[0039] R 106 , R 107 , R 128 and R 129 are each independently preferably a hydrogen atom, an alkyl group having 1 to 15 carbon atoms, or an aryl group having 5 to 20 carbon atoms (which may include a linear, cyclic, or branched alkyl group), more preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms. 106 and R 107 , R 128 and R 129 are preferably the same group.

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

[0041] X - As for I - , B.F. 4 - , P.F. 6 - , ClO 4 - or an anion represented by formula (X1) or (X2), and preferably BF 4 - , or P.F. 6 - It is.

[0042] [ka]

[0043] In the following description, R 101 ~R 114 The portion excluding is also called the skeleton (A1). The same applies to other dyes.

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

[0045] [ka]

[0046] In formula (A11) and formula (A12), R 101 ~R 114 and X - is the same as in formula (A1). 115 ~R 120 R each independently represents a hydrogen atom, a halogen atom, an alkyl group or alkoxy group having 1 to 15 carbon atoms which may have a substituent, or an aryl group having 5 to 20 carbon atoms. 115 ~R120 are each independently preferably a hydrogen atom, an alkyl group having 1 to 15 carbon atoms, or an aryl group having 5 to 20 carbon atoms (which may include a linear, cyclic, or branched alkyl group), more preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms. 115 ~R 120 are preferably the same group.

[0047] In formula (A2), a compound in which n2 is 1 is shown in formula (A21) below, and a compound in which n2 is 0 is shown in formula (A22) below.

[0048] [ka]

[0049] In formula (A21) and formula (A22), R 121 ~R 136 and X - is the same as in formula (A2). 137 ~R 142 R each independently represents a hydrogen atom, a halogen atom, an alkyl group or alkoxy group having 1 to 15 carbon atoms which may have a substituent, or an aryl group having 5 to 20 carbon atoms. 137 ~R 142 are each independently preferably a hydrogen atom, an alkyl group having 1 to 15 carbon atoms, or an aryl group having 5 to 20 carbon atoms (which may include a linear, cyclic, or branched alkyl group), more preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms. 137 ~R 142 are preferably the same group.

[0050] More specifically, the compounds represented by formula (A11), formula (A12), formula (A21), and formula (A22) each include compounds in which the atom or group bonded to each skeleton is an atom or group shown in the following Tables 1 to 4. In all of the compounds shown in Tables 1 and 2, R 101 ~R 109 are all the same on the left and right sides of the formula. In all compounds shown in Tables 3 and 4, R 121 ~R 131is identical on both sides of the equation.

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

[0052] [Table 1]

[0053] As the dye (A11), from the viewpoints of synthesis, solubility in the resin, heat resistance and light resistance, (A11-1) to (A11-4), (A11-9) to (A11-12), and (A11-17) to (A11-20) are preferred.

[0054] [Table 2]

[0055] As the dye (A12), from the viewpoints of synthesis, solubility in the resin, heat resistance and light resistance, (A12-1) to (A12-4), (A12-9) to (A12-12), and (A12-17) to (A12-20) are preferred.

[0056] [Table 3]

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

[0058]

Table 4

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

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

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

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

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

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

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

[0066] The squarylium dye is preferably a compound represented by the following formula (I).

[0067] [ka]

[0068] In the formula (I), the symbols are as follows: R 24 and R 26 each independently represents a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group or an alkoxy group having 1 to 6 carbon atoms, an acyloxy group having 1 to 10 carbon atoms, -NR 27 R 28 (R 27 and R 28 are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, -C(=O)-R 29 (R 29 is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 11 carbon atoms, or an aryl group having 7 to 18 carbon atoms which may have a substituent and which may have an oxygen atom between the carbon atoms), -NHR 30 , or -SO 2 -R 30 (R 30represents a hydrocarbon group having 1 to 25 carbon atoms, each of which may have one or more hydrogen atoms substituted with a halogen atom, a hydroxyl group, a carboxy group, a sulfo group, or a cyano group, and which may contain an unsaturated bond, an oxygen atom, or a saturated or unsaturated ring structure between carbon atoms), or a group represented by the following formula (S) (R 41 , R 42 each independently represents a hydrogen atom, a halogen atom, or an alkyl or alkoxy group having 1 to 10 carbon atoms. k is 2 or 3.

[0069] [ka]

[0070] R 21 and R 22 , R 22 and R 25 , and R 21 and R 23 may be linked to each other to form, together with the nitrogen atom, a 5- or 6-membered heterocycle A, heterocycle B, and heterocycle C, respectively.

[0071] R when heterocycle A is formed 21 and R 22 represents a divalent group -Q- to which these are bonded, which is an alkylene group or an alkyleneoxy group in which the hydrogen atom may be substituted with an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an acyloxy group having 1 to 10 carbon atoms which may have a substituent.

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

[0073] [ka]

[0074] In formula (1x), the four Z's each independently represent a hydrogen atom, a hydroxyl group, an alkyl group or an alkoxy group having 1 to 6 carbon atoms, or -NR 38 R 39 (R 38 and R 39 R each independently represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. 31 ~R 36 each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 10 carbon atoms; R 37 represents an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms.

[0075] R 27 , R 28 , R 29 , R 31 ~R 37 , R when not forming a heterocycle 21 ~R 23 , and R 25 may be bonded to any other of these to form a 5- or 6-membered ring. 31 and R 36 , R 31 and R 37 may be directly bonded.

[0076] When R does not form a heterocycle 21 and R 22each independently represents a hydrogen atom, an alkyl group or an aryl group having 1 to 6 carbon atoms which may have a substituent, or an aryl group or an arylaryl group having 6 to 11 carbon atoms which may have a substituent. 23 and R 25 each independently represents a hydrogen atom, a halogen atom, or an alkyl or alkoxy group having 1 to 6 carbon atoms.

[0077] As the compound (I), for example, a compound represented by formula (I-1) is preferable from the viewpoint of increasing the visible light transmittance.

[0078] [ka]

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

[0080] In compound (I-1), X 1 As the group (2x), the group (2x) is preferable. 1 is preferably a single bond or a group (1y). In this case, R 31 ~R 36 is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom or a methyl group. 1 -X 1 Specific examples of - include divalent organic groups represented by the formulas (11-1) to (12-3).

[0081] -C(CH 3 ) 2 -CH(CH 3 )- …(11-1) -C(CH 3 ) 2 -CH 2 - ... (11-2) -C(CH 3 ) 2 -CH(C 2 H 5 )- …(11-3) -C(CH 3 ) 2 -C(CH 3 )(nC 3 H 7 )- …(11-4) -C(CH 3 ) 2 -CH 2 -CH 2 - ...(12-1) -C(CH 3 ) 2 -CH 2 -CH(CH 3 )- …(12-2) -C(CH 3 ) 2 -CH(CH 3 )-CH 2 - ... (12-3)

[0082] In addition, in compound (I-1), R 21 From the viewpoints of solubility, heat resistance, and the steepness of the change in the spectral transmittance curve near the boundary between the visible region and the near infrared region, each of the groups is preferably independently represented by formula (4-1) or (4-2).

[0083] [ka]

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

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

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

[0087] Examples of the diimmonium dye include the diimmonium dyes described in WO 2014 / 168189.

[0088] The resin film may contain one type of dye (B) alone or a combination of two or more types.

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

[0090] <Other dyes> In addition to the NIR dye, the substrate may contain other dyes, for example UV dyes. Specific examples of UV dyes include oxazole-based, merocyanine-based, cyanine-based, naphthalimide-based, oxadiazole-based, oxazine-based, oxazolidine-based, naphthalic acid-based, styryl-based, anthracene-based, cyclic carbonyl-based, triazole-based dyes, etc. The UV dyes may be used alone or in combination of two or more kinds.

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

[0092] The resin in the resin layer is preferably a transparent resin. As the transparent resin, a polymer composed of an alicyclic compound is preferable from the viewpoint that the NIR dye (A) forms an association state and the near infrared light absorption band is easily broadened. Such a polymer includes a cyclic alkane resin and a cyclic olefin resin, and these resins may be used alone or in combination of two or more.

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

[0094] As the transparent inorganic material, glass or a crystalline material is preferable. Glass that can be used for the support includes absorption-type glass (near-infrared absorbing glass) containing copper ions in phosphate glass or phosphate glass, soda-lime glass, borosilicate glass, alkali-free glass, quartz glass, etc. As the glass, absorption glass is preferable depending on the purpose, and phosphate glass and phosphate glass are preferable from the viewpoint of absorbing infrared light. When it is desired to capture a large amount of red light (600 to 700 nm), alkali glass, alkali-free glass, and quartz glass are preferable. Note that "phosphate glass" is a glass in which part of the skeleton is SiO 2 Also included is a silicophosphate glass consisting of

[0095] The glass to be used may be chemically strengthened glass obtained by exchanging alkali metal ions having a small ionic radius (e.g., Li ions, Na ions) present on the main surface of the glass sheet with alkali ions having a larger ionic radius (e.g., Na ions or K ions for Li ions, and K ions for Na ions) through ion exchange at a temperature equal to or lower than the glass transition point.

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

[0097] As the support, from the viewpoint of shape stability related to long-term reliability of spectroscopic characteristics, mechanical characteristics, etc., and handling properties during filter production, inorganic materials are preferred, and glass and sapphire are particularly preferred.

[0098] The resin film can be formed by dissolving or dispersing the dye (A), the resin or the raw material components of the resin, and each component that is mixed as necessary in a solvent to prepare a coating liquid, applying the coating liquid to a support, drying it, and further curing it as necessary. The support may be the support included in the present filter, or may be a peelable support used only when forming the resin film. The solvent may be a dispersion medium that can be stably dispersed or a solvent that can dissolve the material.

[0099] The coating liquid may also contain a surfactant to improve voids caused by microbubbles, depressions caused by the adhesion of foreign matter, and repellency during the drying process. For example, a dip coating method, a cast coating method, or a spin coating method can be used for coating the coating liquid. After the coating liquid is applied onto a support, a resin film is formed by drying. When the coating liquid contains raw materials for a transparent resin, a curing process such as heat curing or light curing is further performed.

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

[0101] The optical filter may have one or more resin layers in it. When the optical filter has two or more resin layers, the layers may have the same or different configurations.

[0102] When the substrate is a multi-layer structure (composite substrate) having a support and a resin film containing a dye (A) and a resin, the thickness of the resin film is preferably 5 μm or less, more preferably 3 μm or less. The thickness of the resin film is preferably 0.5 μm or more. When the resin film is made of multiple layers, the total thickness of the layers is preferably 0.5 to 10 μm. When the substrate has a single layer structure (resin substrate) made of a resin film containing the dye (A), the thickness of the resin film is preferably 50 to 300 μm. The optical filter of the present invention contains an NIR dye (A) that satisfies specific spectral characteristics, and thus can block near-infrared light over a wide range and efficiently even with a small dye content. This allows the resin film containing the dye (A) to be made thinner.

[0103] The shape of the substrate is not particularly limited, and may be a block, plate, or film. In addition, the thickness of the substrate is preferably 300 μm or less from the viewpoints of reducing warping during formation of the dielectric multilayer film and reducing the height of the optical filter. When the substrate is a resin substrate made of a resin film, the thickness is preferably 50 to 300 μm, and when the substrate is a composite substrate comprising a support and a resin film, the thickness is preferably 100 to 300 μm.

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

[0105] In the present filter, at least one of the dielectric multilayer films is preferably designed as a near-infrared reflective layer (hereinafter also referred to as a NIR reflective layer), and the other of the dielectric multilayer films is preferably designed as a NIR reflective layer, a reflective layer having a reflection range other than the near-infrared range, or an anti-reflection layer.

[0106] The NIR reflective layer is a dielectric multilayer film designed to block light in the near infrared region. The NIR reflective layer has wavelength selectivity that transmits visible light and mainly reflects light in the near infrared region other than the light-shielding region of the resin film. The reflection region of the NIR reflective layer may include a light-shielding region in the near infrared region of the resin film. The NIR reflective layer is not limited to NIR reflection characteristics, and may be appropriately designed to further block light in wavelength regions other than the near infrared region, for example, the near ultraviolet region.

[0107] The NIR reflective layer is composed of, for example, a dielectric multilayer film in which a dielectric film with a low refractive index (low refractive index film) and a dielectric film with a high refractive index (high refractive index film) are alternately laminated. The high refractive index film preferably has a refractive index of 1.6 or more, more preferably 2.2 to 2.5. Examples of the material of the high refractive index film include Ta. 2 O 5 , TiO 2 , Nb 2 O 5 Among these, TiO is the most popular from the viewpoints of film-forming property, reproducibility in refractive index, stability, etc. 2 is preferred.

[0108] On the other hand, the low refractive index film preferably has a refractive index of less than 1.6, more preferably 1.45 or more and less than 1.55. Examples of the material for the low refractive index film include SiO 2 , SiO x N y From the viewpoints of reproducibility, stability, and economy in film formation, SiO 2 is preferred.

[0109] Furthermore, it is preferable that the NIR reflective layer has a steep change in transmittance in the boundary wavelength region between the transmission region and the light blocking region. For this purpose, the total number of laminated layers of the dielectric multilayer film constituting the reflective layer is preferably 15 layers or more, more preferably 25 layers or more, and even more preferably 30 layers or more. However, since warping or an increase in film thickness occurs when the total number of laminated layers is large, the total number of laminated layers is preferably 100 layers or less, more preferably 75 layers or less, and even more preferably 60 layers or less. Moreover, the film thickness of the reflective layer is preferably 2 to 10 μm overall.

[0110] If the total number of layers and the thickness of the dielectric multilayer film are within the above ranges, the NIR reflective layer satisfies the requirement for miniaturization and can suppress the incidence angle dependency while maintaining high productivity. In addition, the dielectric multilayer film can be formed by, for example, a vacuum film formation process such as a CVD method, a sputtering method, or a vacuum deposition method, or a wet film formation process such as a spray method or a dip method.

[0111] The NIR reflective layer may have a single layer (a group of dielectric multilayer films) that provides a predetermined spectral characteristic, or may have two layers that provide a predetermined spectral characteristic. When there are two or more layers, each reflective layer may have the same or different configurations. When there are two or more reflective layers, they are usually composed of a plurality of reflective layers with different reflection bands. When two reflective layers are provided, one of them may be a near-infrared reflective layer that blocks light in the short wavelength band of the near-infrared region, and the other may be a near-infrared / near-ultraviolet reflective layer that blocks light in both the long wavelength band of the near-infrared region and the near-ultraviolet region.

[0112] Examples of the antireflection layer include a dielectric multilayer film, an intermediate refractive index medium, and a moth-eye structure in which the refractive index changes gradually. Among these, a dielectric multilayer film is preferred from the viewpoints of optical efficiency and productivity. The antireflection layer is obtained by alternately laminating dielectric films in the same manner as the reflective layer.

[0113] <Optical filters> It is preferable that the optical filter of the present invention, having the above-mentioned configuration, satisfies all of the following spectral characteristics (iii-1) to (iii-7). (iii-1) Average transmittance T in the spectral transmittance curve with a wavelength of 440 to 490 nm and an incident angle of 0 degrees440-490(0deg)AVE More than 85% (iii-2) Average transmittance T in the spectral transmittance curve with a wavelength of 440 to 490 nm and an incident angle of 30 degrees 440-490(30deg)AVE More than 85% (iii-3) Average transmittance T in the spectral transmittance curve with a wavelength of 500 to 570 nm and an incident angle of 0 degrees 500-570(0deg)AVE More than 90% (iii-4) Average transmittance T in the spectral transmittance curve with a wavelength of 500 to 570 nm and an incident angle of 30 degrees 500-570(30deg)AVE More than 90% (iii-5) Maximum transmittance T in the spectral transmittance curve with a wavelength of 700 to 850 nm and an incident angle of 0 degrees 700-850(0deg)MAX Less than 3% (iii-6) Maximum transmittance T in the spectral transmittance curve with a wavelength of 700 to 850 nm and an incident angle of 30 degrees 700-850(30deg)MAX Less than 1% (iii-7) Maximum transmittance T in the spectral transmittance curve with a wavelength of 700 to 850 nm and an incident angle of 60 degrees 700-850(60deg)MAX Less than 1%

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

[0115] By satisfying the spectral characteristics (iii-5) to (iii-7), an optical filter that does not leak light even at a high incident angle and has a high near-infrared light blocking property can be obtained. The spectral characteristic (iii-5) is preferably 2% or less. The spectral characteristic (iii-6) is preferably 0.7% or less. The spectral characteristic (iii-7) is preferably 0.8% or less.

[0116] The filter may also include other components (layers) that absorb light using inorganic particles that control the transmission and absorption of light in a specific wavelength range. Specific examples of inorganic particles include ITO (indium tin oxide), ATO (antimony-doped tin oxide), cesium tungstate, lanthanum boride, etc. ITO particles and cesium tungstate particles have high visible light transmittance and light absorption over a wide range of infrared wavelengths exceeding 1200 nm, and therefore can be used when such infrared light shielding is required.

[0117] When the present filter is used in an imaging device such as a digital still camera, the imaging device can provide an imaging device with excellent color reproducibility. An imaging device using the present filter includes a solid-state imaging element, an imaging lens, and the present filter. The present filter can be used, for example, by being disposed between the imaging lens and the solid-state imaging element, or by being directly attached to the solid-state imaging element, imaging lens, etc. of the imaging device via an adhesive layer. EXAMPLES

[0118] Next, the present invention will be described more specifically with reference to examples. The spectral characteristics were measured using an ultraviolet-visible spectrophotometer (UH-4150, manufactured by Hitachi High-Technologies Corporation). Unless the angle of incidence is specifically stated, the spectral characteristics are values ​​measured at an angle of incidence of 0 degrees (perpendicular to the optical filter).

[0119] The dyes used in each example are as follows: Compounds 1 to 9 (cyanine compounds): These were synthesized with reference to the synthesis method described in Dyes and Pigments 73 (2007), p. 344-352. Compound 10 (squarylium compound): Synthesized with reference to WO 2014 / 088063. Compound 11 (squarylium compound): Synthesized with reference to JP 2017-110209 A.

[0120] [ka]

[0121] [ka]

[0122] [ka]

[0123] [ka]

[0124] <Example 1-1: Spectral characteristics of NIR dye in resin> NIR dye compound 1 (7.5% by mass) and polyimide resin (C-3G30G, manufactured by Mitsubishi Gas Chemical Co., Ltd.) diluted with an organic solvent (cyclohexanone) were mixed to thoroughly dissolve the polyimide solution and the dye. The obtained dye solution was applied to a glass substrate (alkali glass, Shotto D263) using spin coating, and the organic solvent was removed by sufficient heating to form a dye-containing resin thin film (coated film) with a thickness of 1 μm. The resulting thin film was subjected to measurement of transmission spectroscopy in the wavelength range of 350 nm to 1200 nm in an incident direction of 0 deg and reflection spectroscopy in an incident direction of 5 deg. The transmittance was expressed as the internal transmittance represented by the following formula. Internal transmittance (%) = {Actual transmittance (0deg) / (100-Reflectance (5deg) )}×100 The absorbance is a value calculated from the internal transmittance using the following formula. Absorbance = -log10 (internal transmittance / 100)

[0125] <Examples 1-2 to 1-18> A dye-containing resin thin film was prepared in the same manner as in Example 1-1, except that the NIR dye compound 1 was replaced with the NIR dye shown in the table below in the amount shown in the table below, the polyimide resin was replaced with one of the resins shown below, and the thickness of the thin film was set to the value shown in the table below. The transmission spectrum was measured. Polyester resin: Osaka Gas Chemicals Cycloolefin resin: JSR ARTON F4520 The results are shown in the table below.

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

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

[0128] [Table 5]

[0129] The results of Examples 1-10 to 1-14 show that the external salt type cyanine dyes maintained high transmittance of blue light in the alicyclic compound polymer and exhibited wide range absorption characteristics of near infrared light.

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

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

[0132] The IR50 and IR30 bands were compared for solution and resin spectra using the same NIR dye. 5 shows the solution spectrum of Example 2-4 and the resin spectrum of Example 2-11 for Compound 6. The solid line shows the resin spectrum, and the dashed line shows the solution spectrum.

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

[0134] Examples 2-1 to 2-7 are reference examples, Examples 2-8 to 2-12 are working examples, and Examples 2-13 and 2-14 are comparative examples.

[0135] [Table 6]

[0136] [Table 7]

[0137] From the above results, in Examples 2-8 to 2-12 in which an external salt type cyanine dye was used as the NIR dye, the IR30 width and the IR50 width were significantly wider in the resin than in the solution. That is, the absorption spectrum was broadened in the resin.

[0138] <Example 3-1: Spectral characteristics of optical filters> Compound 11, an NIR dye, was added to polyimide resin (C-3G30G manufactured by Mitsubishi Gas Chemical Company) in an amount of 5.25% by mass relative to the resin, and cyclohexanone was further added as a solvent to thoroughly dissolve the dye (dye solution 1). Compound 6, an NIR dye, was added to a cycloolefin resin (ARTON resin F4520 manufactured by JSR Corporation) in an amount of 2% by mass relative to the resin, and cyclohexanone was further added as a solvent to dissolve the dye sufficiently (dye solution 2). An ultraviolet / infrared cut multilayer film with a transmission band of 400 nm to 700 nm was deposited on a glass substrate (alkali glass, Shotto D263). Dye solution 1 was spin-coated on the surface opposite the ultraviolet / infrared cut multilayer film to form a 1 μm-thick resin film 1. Dye solution 2 was spin-coated on top of resin film 1 to form a 1.6 μm-thick resin film 2. SiO 2 and TiO 2 A dielectric multilayer film (anti-reflection film) composed of the above was formed by deposition to prepare an optical filter 3-1.

[0139] <Example 3-2> An optical filter 3-2 was produced in the same manner as in Example 3-1, except that the content of compound 11 in producing resin film 1 was 5.5 mass %, and resin film 2 was not applied.

[0140] For each optical filter, the transmission spectrum was measured in the wavelength range of 350 nm to 1200 nm at the incident directions of 0 deg, 30 deg, and 60 deg using a spectrophotometer. The results are shown in the table below. FIG. 6 shows the spectral transmittance curve of the optical filter 3-1.

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

[0142] [Table 8]

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

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

[0145] The optical filter of the present invention has good near-infrared light shielding properties, in which the near-infrared light shielding property is suppressed from decreasing particularly at a high incidence angle, while maintaining good near-infrared light shielding properties and visible light transmittance, particularly blue light transmittance, and is useful for applications in information acquisition devices such as cameras and sensors for transport aircraft, which have become increasingly high-performance in recent years. [Explanation of symbols]

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

Claims

1. An optical filter comprising a substrate and a dielectric multilayer film laminated as an outermost layer on at least one main surface side of the substrate, the substrate includes a resin film including a dye (A) that is a near-infrared absorbing dye and a resin, The dye (A) satisfies all of the following spectral characteristics (i-1) to (i-4) in a spectral transmittance curve of a coating film obtained by dissolving the dye (A) in the resin and coating the coating film on an alkali glass plate, (i-1) When the shortest wavelength at which the transmittance is 30% in the wavelength range of 600 to 800 nm is IR30a, and the longest wavelength at which the transmittance is 30% in the wavelength range of 700 to 1200 nm is IR30b, The absolute value of the difference between IR30a and IR30b is 170 nm or more (i-2) When the shortest wavelength at which the transmittance is 50% in the wavelength range of 600 to 800 nm is defined as IR50a, and the longest wavelength at which the transmittance is 50% in the wavelength range of 700 to 1200 nm is defined as IR50b, The absolute value of the difference between IR50a and IR50b is 200 nm or more (i-3) Absorbance A at a wavelength of 440 nm ４４０ and absorbance A at a wavelength of 700 nm ７００ Relationship with A ４４０ / A ７００ ≦0.14 (i-4) Absorbance A at a wavelength of 490 nm ４９０ and absorbance A at a wavelength of 700 nm ７００ Relationship with A ４９０ / A ７００ ≦0.10 The optical filter, wherein the dye (A) contains at least one of a compound represented by the following formula (A1) and a compound represented by the following formula (A2): 【Chemistry 1】 In the formulae (A1) and (A2), the symbols are as follows: R 101 , R 106 , and R 107 each independently represent a hydrogen atom, an alkyl group or alkoxy group having 1 to 15 carbon atoms which may have a substituent, or an aryl group having 5 to 20 carbon atoms. R 121 , R 128 , and R 129 each independently represent a hydrogen atom, a halogen atom, an alkyl group or alkoxy group having 1 to 15 carbon atoms which may have a substituent, or an aryl group having 5 to 20 carbon atoms. R 102 to R 105 , R 108 , R 109 , R 122 to R 127 , R 130 , and R 131 each independently represent a hydrogen atom, an alkyl group or alkoxy group having 1 to 15 carbon atoms, or an aryl group having 5 to 20 carbon atoms. R 110 to 114 and R 132 to 136 each independently represent a hydrogen atom, a halogen atom, or an alkyl or alkoxy group having 1 to 15 carbon atoms. X − represents a monovalent anion. n1 and n2 each independently represent 0 or 1. A hydrogen atom bonded to the carbocycle containing -(CH 2 ) n1 - and the carbocycle containing -(CH 2 ) n2 - may be substituted with a halogen atom, an alkyl group having 1 to 15 carbon atoms which may have a substituent, or an aryl group having 5 to 20 carbon atoms.

2. 2. The optical filter according to claim 1, wherein the dye (A) further satisfies the following spectral characteristic (i-5) in a spectral transmittance curve of the coating film. (i-5) the product of the content of the dye (A) in the coating film and the thickness of the coating film is 20 (mass% μm) or less.

3. 3. The optical filter according to claim 1, wherein the dye (A) further satisfies the following spectral characteristic (i-6) in a spectral transmittance curve of the coating film. (i-6) Absorbance A at a wavelength of 570 nm ５７０ and absorbance A at a wavelength of 700 nm ７００ Relationship with A ５７０ / A ７００ ≦0.11

4. 4. The optical filter according to claim 1, wherein the dye (A) further satisfies the following spectral characteristic (i-7) in a spectral transmittance curve of the coating film. (i-7) Absorbance A at a wavelength of 630 nm ６３０ and absorbance A at a wavelength of 700 nm ７００ Relationship with A ６３０ / A ７００ ≦0.12

5. 5. The optical filter according to claim 1, wherein the dye (A) further satisfies the following spectral characteristic (i-8) in a spectral transmittance curve of the coating film. (i-8) Average internal transmittance T in the spectral transmittance curve for wavelengths of 700 to 800 nm ７００－８００ 2 to 25%

6. In the spectral characteristic (i-1), the absolute value of the difference between IR30a and IR30b is 190 nm or more; In the spectral characteristic (i-2), the absolute value of the difference between IR50a and IR50b is 230 nm or more; In the spectroscopic characteristic (i-3), A ４４０ / A ７００ ≦0.11, In the spectroscopic characteristic (i-4), A ４９０ / A ７００ ≦0.07; The optical filter according to any one of claims 1 to 5.

7. 7. The optical filter according to claim 1, wherein the resin film has a thickness of 10 μm or less.

8. The optical filter according to any one of claims 1 to 7, wherein the substrate includes a support and the resin film, the resin film is laminated on at least one main surface of the support, and the thickness of the resin film is 5 μm or less.

9. 9. The optical filter according to claim 1, wherein the dye (A) satisfies the following properties (ii-1) and (ii-2): In the spectral transmittance curve measured by dissolving the dye (A) in dichloromethane so that the transmittance at the maximum absorption wavelength is 10%, The shortest wavelength at which the transmittance is 30% in the wavelength range of 600 to 900 nm is IR30a （ＤＩＣ） The longest wavelength at which the transmittance is 30% is IR30b. （ＤＩＣ） The shortest wavelength at which the transmittance is 50% is IR50a. （ＤＩＣ） The longest wavelength at which the transmittance is 50% is IR50b. （ＤＩＣ） year, The dye (A) is dissolved in the resin and applied onto an alkali glass plate so that the transmittance at the maximum absorption wavelength is 10%, and the spectral transmittance curve of the coating film is The shortest wavelength at which the transmittance is 30% in the wavelength range of 600 to 900 nm is IR30a （ＰＯ） The longest wavelength at which the transmittance is 30% is IR30b. （ＰＯ） The shortest wavelength at which the transmittance is 50% is IR50a. （ＰＯ） The longest wavelength at which the transmittance is 50% is IR50b. （ＰＯ） When (ii-1) IR30a （ＰＯ） and IR30b （ＰＯ） The absolute value of the difference between （ＤＩＣ） and IR30b （ＤＩＣ） More than three times the absolute value of the difference between (ii-2) IR50a （ＰＯ） and IR50b （ＰＯ） The absolute value of the difference between （ＤＩＣ） and IR50b （ＤＩＣ） More than 2.8 times the absolute value of the difference between

10. 10. The optical filter according to claim 1, wherein the resin is a polymer composed of an alicyclic compound.

11. 11. The optical filter according to claim 1, wherein the resin film further contains at least one dye (B) selected from a squarylium dye, a phthalocyanine dye, and a diimmonium dye.

12. The optical filter according to any one of claims 1 to 11, which satisfies all of the following spectral characteristics (iii-1) to (iii-7): (iii-1) Average transmittance T in a spectral transmittance curve with a wavelength of 440 to 490 nm and an incident angle of 0 degrees ４４０－４９０（０ｄｅｇ）ＡＶＥ More than 85% (iii-2) Average transmittance T in a spectral transmittance curve with a wavelength of 440 to 490 nm and an incident angle of 30 degrees ４４０－４９０（３０ｄｅｇ）ＡＶＥ More than 85% (iii-3) Average transmittance T in a spectral transmittance curve with a wavelength of 500 to 570 nm and an incident angle of 0 degrees ５００－５７０（０ｄｅｇ）ＡＶＥ More than 90% (iii-4) Average transmittance T in a spectral transmittance curve with a wavelength of 500 to 570 nm and an incident angle of 30 degrees ５００－５７０（３０ｄｅｇ）ＡＶＥ More than 90% (iii-5) Maximum transmittance T in the spectral transmittance curve at a wavelength of 700 to 850 nm and an incident angle of 0 degrees ７００－８５０（０ｄｅｇ）ＭＡＸ Less than 3% (iii-6) Maximum transmittance T in a spectral transmittance curve with a wavelength of 700 to 850 nm and an incident angle of 30 degrees ７００－８５０（３０ｄｅｇ）ＭＡＸ Less than 1% (iii-7) Maximum transmittance T in a spectral transmittance curve with a wavelength of 700 to 850 nm and an incident angle of 60 degrees ７００－８５０（６０ｄｅｇ）ＭＡＸ Less than 1%

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