Optical filter

Abstract

To provide an optical filter with high transmittance of visible light and high blocking of near-infrared light capable of suppressing ripples even at high angles of incidence while suppressing the change in blocking ability at high incidence angles of near-infrared light.SOLUTION: The optical filter includes: a substrate; and a dielectric multilayer film laminated on at least one of the main surfaces of the substrate. The substrate has at least one layer of a resin film containing a dye (IR) and a resin with a total thickness of 0.3 to 20 μm. The optical filter is an optical filter that satisfies the spectral transmittance curve at incidence angles of 0 degrees, 5 degrees, and 40 degrees satisfies all of the specific optical characteristics (i-1), (i-2), (i-4), (i-7) to (i-10).SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] In 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 ultraviolet wavelength range (hereinafter also referred to as "ultraviolet light") and near-infrared wavelength range (hereinafter also referred to as "near-infrared light").

[0003] Such optical filters can be made in 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 the optical interference is utilized to reflect light to be blocked.

[0004] Optical filters having a dielectric multilayer film have problems such as changes in the spectral transmittance curve depending on the incident angle, light leakage due to high transmittance of near-infrared light that should have high reflectance at high incident angles, and noise caused by 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 filters are used, the spectral sensitivity of the solid-state imaging element may be affected by the incident angle. In particular, with the recent trend toward lowering the height of camera modules, it is expected that they will be used under high incident angle conditions.

[0005] Furthermore, in dielectric multilayer films, drastic changes in transmittance (ripples) can occur due to interference caused by reflected light at the interfaces of each layer depending on the number of layers stacked in the multilayer film. The larger the angle of incidence, the greater the ripples that occur. Dielectric multilayer films used in optical filters that transmit light in the visible wavelength range and block light in the near-infrared wavelength range are designed to transmit visible light and block light with long wavelengths beyond the near-infrared range. Conventional dielectric multilayer films are designed to suppress light leakage in the near-infrared range, but ripples occur in the visible light range, and the incident angle that is considered is only up to about 30 degrees.

[0006] Patent Document 1 describes a near-infrared cut filter that includes a dielectric multilayer film and suppresses ripples in the visible light region at high angles of incidence. Patent Document 2 describes an optical filter that reduces the incidence angle dependency by combining various near-infrared absorbing dyes without providing a dielectric multilayer film. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2019-120942 A [Patent Document 2] JP 2019-32371 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, the near-infrared cut filter described in Patent Document 1 has a spectral transmittance curve that changes at high angles of incidence, and the blocking ability in the near-infrared light region changes. The optical filter described in Patent Document 2 has low transmittance in the visible light region because visible light is also absorbed by the dye used in large amounts to ensure the near-infrared light shielding properties and incidence angle dependency.

[0009] The present invention aims to provide an optical filter that has high transmittance for visible light and high shielding property for near-infrared light, in which ripples are suppressed even at high angles of incidence, and in which changes in shielding property at high angles of incidence of near-infrared light are suppressed. [Means for solving the problem]

[0010] The present invention provides an optical filter having the following configuration. [1] An optical filter comprising a substrate and a dielectric multilayer film laminated on at least one main surface side of the substrate, The substrate has at least one resin film containing a dye (IR) and a resin, The total thickness of the resin film is 0.3 to 20 μm, The optical filter satisfies all of the following optical characteristics (i-1), (i-2), (i-4), and (i-7) to (i-10). (i-1) On at least one surface of the optical filter, the average reflectance R 450-500(5deg)AVE is 3% or less, and the average reflectance R at an incident angle of 40 degrees 450-500(40deg)AVE Less than 5% (i-2) On at least one surface of the optical filter, the average reflectance R 500-580(5deg)AVE is 2.5% or less, and the average reflectance R at an incident angle of 40 degrees 500-580(40deg)AVE Less than 4% (i-4) The maximum reflectance R at a wavelength of 450 to 580 nm and an incident angle of 5 degrees on at least one surface of the optical filter 450-580(5deg)MAX is 4% or less, and the maximum reflectance R at an incident angle of 40 degrees 450-580(40deg)MAX Less than 6% (i-7) Average transmittance T at an incident angle of 0 degrees for wavelengths of 450 to 580 nm 450-580(0deg)AVE More than 88% (i-8) In the wavelength range of 600 to 800 nm, the absolute value of the difference between the wavelength at which the transmittance is 20% at an incident angle of 0 degrees and the wavelength at which the transmittance is 20% at an incident angle of 40 degrees is 10 nm or less. (i-9) In the wavelength range of 600 to 800 nm, the wavelength at which the transmittance is 20% at an incident angle of 0 degrees is in the range of 640 to 690 nm. (i-10) Maximum transmittance T at an incident angle of 0 degrees in the wavelength range of 750 to 1000 nm 750-1000(0deg)MAX is 1% or less, and the maximum transmittance T at an incidence angle of 40 degrees 750-1000(40deg)MAX Less than 1% Effect of the Invention

[0011] According to the present invention, an optical filter can be provided which has high transmittance for visible light and high shielding property for near-infrared light, in which ripples are suppressed even at high angles of incidence, and in which changes in shielding property at high angles of incidence of near-infrared light are suppressed. [Brief description of the drawings]

[0012] [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 the dielectric multilayer film 1 of Example 2-1. [Figure 6] FIG. 6 is a diagram showing the spectral transmittance curve of the dielectric multilayer film 2 of Example 2-2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] 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.

[0014] 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, the transmittance of a resin film including a case where a dye is contained in the resin, and the spectrum of the transmittance measured by dissolving the dye in a solvent such as dichloromethane are all "internal transmittances" even when they are referred to as "transmittances." On the other hand, the transmittance of an optical filter having a dielectric multilayer film is an actually measured transmittance.

[0015] 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. The optical properties can be measured using a UV-Vis spectrophotometer. In this specification, the term "to" indicating a numerical range includes the upper and lower limits.

[0016] <Optical filters> An optical filter according to one embodiment of the present invention (hereinafter also referred to as "this filter") is an optical filter that comprises a substrate and a dielectric multilayer film laminated as an outermost layer on at least one main surface side of the substrate, and that satisfies specific optical characteristics described below. Here, the substrate has a resin film containing a dye (IR) having a maximum absorption wavelength in dichloromethane at 680 to 1000 nm and a resin. The dye (IR) is a NIR dye. By containing a dye that absorbs near infrared rays in the substrate, the deterioration of the optical properties of the dielectric multilayer film at a high incidence angle, for example, the occurrence of light leakage and noise in the near infrared region, can be covered by the absorption properties of the substrate. Each dye and resin will be described later.

[0017] 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. 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" does not only mean that the layer is provided in contact with the main surface of the substrate, but also means that another functional layer is provided between the substrate and the layer.

[0018] The optical filter 1B shown in FIG. 2 is an example having a dielectric multilayer film 30 on both main surfaces of the substrate 10.

[0019] 3 is an example in which a substrate 10 has a support 11 and a resin film 12 laminated on one main surface 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 of the support 11 on which the resin film 12 is not laminated.

[0020] 4 is an example in which a substrate 10 has a support 11 and resin films 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.

[0021] The optical filter of the present invention satisfies all of the following optical properties (i-1) to (i-10). (i-1) Average reflectance R at an incident angle of 5 degrees in the wavelength range of 450 to 500 nm 450-500(5deg)AVE is 3% or less, and the average reflectance R at an incident angle of 40 degrees 450-500(40deg)AVE Less than 5% (i-2) Average reflectance R at an incident angle of 5 degrees in the wavelength range of 500 to 580 nm 500-580(5deg)AVE is 2.5% or less, and the average reflectance R at an incident angle of 40 degrees 500-580(40deg)AVE is 4% or less (i-3) R 450-500(5deg)AVE >The above R 500-580(5deg)AVE And, the R 450-500(40deg)AVE >The above R 500-580(40deg)AVE Satisfying the relationship (i-4) Maximum reflectance R at an incident angle of 5 degrees in the wavelength range of 450 to 580 nm 450-580(5deg)MAX is 4% or less, and the maximum reflectance R at an incident angle of 40 degrees 450-580(40deg)MAX Less than 6% (i-5) At a wavelength of 450 to 500 nm, the maximum difference between the transmittance at an incident angle of 0 degrees and the transmittance at an incident angle of 40 degrees is 6% or less (i-6) At a wavelength of 500 to 580 nm, the maximum difference between the transmittance at an incident angle of 0 degrees and the transmittance at an incident angle of 40 degrees is 5% or less. (i-7) Average transmittance T at an incident angle of 0 degrees for wavelengths of 450 to 580 nm 450-580(0deg)AVE More than 88% (i-8) In the wavelength range of 600 to 800 nm, the absolute value of the difference between the wavelength at which the transmittance is 20% at an incident angle of 0 degrees and the wavelength at which the transmittance is 20% at an incident angle of 40 degrees is 10 nm or less. (i-9) In the wavelength range of 600 to 800 nm, the wavelength at which the transmittance is 20% at an incident angle of 0 degrees is in the range of 640 to 690 nm. (i-10) Maximum transmittance T at an incident angle of 0 degrees in the wavelength range of 750 to 1000 nm 750-1000(0deg)MAX is 1% or less, and the maximum transmittance T at an incidence angle of 40 degrees 750-1000(40deg)MAX Less than 1%

[0022] This filter, which satisfies all of the optical properties (i-1) to (i-10), is an optical filter that has excellent visible light transmittance and near-infrared light blocking properties, and also suppresses the generation of ripples and changes in near-infrared light blocking properties even at a high incident angle of 40 degrees.

[0023] Satisfying the optical properties (i-1), (i-2), and (i-4) means that the reflectance in the visible light region is sufficiently low. In optical properties (i-1), R 450-500(5deg)AVE is preferably 2.5% or less, R 450-500(40deg)AVE is preferably 4.5% or less. In optical properties (i-2), R 500-580(5deg)AVE is preferably 2% or less, R 500-580(40deg)AVE is preferably 3.5% or less. In the optical properties (i-4), R 450-580(5deg)MAX Preferably 3.5% or less, R 450-580(40deg)MAX is preferably 5.5% or less.

[0024] Satisfying the optical characteristic (i-3) means that the reflectance in the green band, which is particularly important for the visibility of the sensor of the imaging device, is low.

[0025] Satisfying the optical property (i-7) means that the transmittance in the visible light region is high, and satisfying the optical properties (i-1), (i-2), and (i-4) to (i-6) means that ripples are suppressed even at high angles of incidence.

[0026] The optical property (i-5) is preferably 5.5% or less, and more preferably 5% or less. The optical property (i-6) is preferably 4.5% or less, and more preferably 4% or less.

[0027] T 450-580(0deg)AVE is preferably 89% or more, more preferably 90% or more.

[0028] Satisfying the optical property (i-8) means that there is little shift (i.e., change in near-infrared light shielding properties) even at a high incident angle in the near-infrared light absorption band of wavelengths from 600 to 800 nm, and color reproducibility is excellent. The optical property (i-8) is preferably 8 nm or less, more preferably 6 nm or less.

[0029] Satisfying the optical property (i-9) means that it is possible to block infrared light and efficiently capture visible transmitted light. The optical property (i-9) is preferably in the range of 645 to 685 nm, more preferably in the range of 650 to 680 nm.

[0030] By satisfying the optical characteristic (i-10), it means that the film has excellent light-shielding properties in the near-infrared to long-wavelength region of 750 to 1000 nm, both at an incident angle of 0 degrees and at a high incident angle of 40 degrees. 750-1000(0deg)MAX is preferably 0.95% or less, more preferably 0.9% or less. 750-1000(40deg)MAX is preferably 0.95% or less, more preferably 0.9% or less.

[0031] <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.

[0032] In the present filter, it is preferable that the dielectric multilayer film satisfies all of the following optical properties (iv-1) to (iv-8). (iv-1) Average transmittance T at an incident angle of 0 degrees in the wavelength range of 450 to 580 nm 450-580(0deg)AVE is 90% or more, and the average transmittance T at an incidence angle of 40 degrees 450-580(40deg)AVEMore than 90% (iv-2) At a wavelength of 450 to 500 nm, the absolute value of the difference between the average transmittance at an incident angle of 0 degrees and the average transmittance at an incident angle of 40 degrees is 3% or less. (iv-3) At a wavelength of 500 to 580 nm, the absolute value of the difference between the average transmittance at an incident angle of 0 degrees and the average transmittance at an incident angle of 40 degrees is 2% or less. (iv-4) At a wavelength of 450 to 500 nm, the maximum difference between the transmittance at an incident angle of 0 degrees and the transmittance at an incident angle of 40 degrees is 6% or less. (iv-5) At a wavelength of 500 to 580 nm, the maximum difference between the transmittance at an incident angle of 0 degrees and the transmittance at an incident angle of 40 degrees is 5% or less. (iv-6) In the wavelength range of 600 to 800 nm, the wavelength at which the transmittance is 20% at an incident angle of 0 degrees is in the range of 720 to 770 nm. (iv-7) Maximum transmittance T at an incident angle of 0 degrees in the wavelength range of 780 to 850 nm 780-850(0deg)MAX is between 4% and 10% (iv-8) Maximum transmittance T at an incident angle of 40 degrees in the wavelength range of 900 to 980 nm 900-980(40deg)MAX is between 1% and 5%

[0033] Satisfying the optical characteristic (iv-1) means that the transmittance in the visible light range is excellent both at an incident angle of 0 degrees and at a high incident angle of 40 degrees. T 450-580(0deg)AVE is preferably 91% or more, more preferably 92% or more. T 450-580(40deg)AVE is preferably 90.5% or more, more preferably 91% or more.

[0034] By satisfying the optical properties (iv-2) to (iv-5), it means that the occurrence of ripples in the visible light region is suppressed even at a high incident angle of 40 degrees. The optical property (iv-2) is preferably 2.5% or less, and more preferably 2% or less. The optical property (iv-3) is preferably 1.6% or less, and more preferably 1.2% or less. The optical property (iv-4) is preferably 5.5% or less, and more preferably 5% or less. The optical property (iv-5) is preferably 4.5% or less, more preferably 4% or less.

[0035] By satisfying the optical property (iv-6), it means that the transmittance in the red band is excellent and the light-shielding property is excellent in the near-infrared light region having a wavelength of 770 nm or more. The optical property (iv-6) is preferably in the range of 725 to 765 nm, more preferably in the range of 730 to 760 nm.

[0036] The optical properties (iv-7) to (iv-8) define the permissible range of light leakage in the near-infrared light region. T 780-850(0deg)MAX is preferably 4 to 9%, more preferably 4 to 8%. T 900-980(40deg)MAX is preferably 1 to 4.5%, more preferably 1 to 4%.

[0037] As shown in the optical characteristics (iv-2) to (iv-5), the dielectric multilayer film of the present invention suppresses the occurrence of ripples in the visible light region even at a high incident angle of 40 degrees. On the other hand, as shown in the above optical characteristics (iv-7) to (iv-8), light leakage may occur at incident angles of 0 degrees and 40 degrees and in the near-infrared wavelength region of 780 nm or more. This wavelength region is covered by the absorption of the NIR dye in the resin film described later, so even if light leakage occurs, the optical filter as a whole blocks light.

[0038] By combining such a dielectric multilayer film with a resin film described later, the optical filter of the present invention is an optical filter that has high visible light transmittance as shown in optical characteristic (i-7) and high near-infrared light shielding property as shown in optical characteristic (i-10), in which ripples are suppressed even at high angles of incidence as shown in optical characteristics (i-1) to (i-2) and (i-4) to (i-6), and in which changes in shielding property at high angles of incidence of near-infrared light are suppressed as shown in optical characteristic (i-8).

[0039] 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.

[0040] 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 blocking region of the resin film that is the absorption layer. The reflection region of the NIR reflective layer may include the light blocking 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.

[0041] 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 materials for the high refractive index film include Ta2O5, TiO2, and Nb2O5. Among these, TiO2 is preferred in terms of film formability, reproducibility in refractive index, etc., stability, etc.

[0042] On the other hand, the low refractive index film preferably has a refractive index of less than 1.6, more preferably 1.45 or more and less than 1.55. Examples of the material for the low refractive index film include SiO2, SiO x N y From the viewpoints of reproducibility, stability, economy, etc. in film formation, SiO2 is preferred.

[0043] In order to obtain a multilayer film that suppresses ripples even at high angles of incidence but allows light leakage in the near-infrared wavelength region of 780 nm and beyond, for example, the number of layers in the multilayer film can be reduced.

[0044] In terms of light shielding properties in the near-infrared wavelength region, the total number of laminated layers of the dielectric multilayer film constituting the NIR reflective layer is preferably 20 or more, more preferably 25 or more, and even more preferably 30 or more. However, since a large total number of laminated layers may cause ripples or warping or an increase in film thickness, the total number of laminated layers is preferably 100 or less, more preferably 75 or less, and even more preferably 60 or less. Moreover, the thickness of the reflective layer is preferably 2 to 10 μm as a whole from the viewpoint of reducing warping of the optical filter.

[0045] The dielectric multilayer film can be formed by, for example, a vacuum film-forming process such as a CVD method, a sputtering method, or a vacuum deposition method, or a wet film-forming process such as a spray method or a dipping method.

[0046] The NIR reflective layer may have a single layer (a group of dielectric multilayer films) that provides a predetermined optical characteristic, or may have two layers that provide a predetermined optical 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 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.

[0047] 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 multilayer films, similar to the reflective layer.

[0048] <Base material> In the optical filter of the present invention, the substrate has a resin film containing an NIR dye (IR) and a resin, which will be described later.

[0049] <Optical properties of resin film> It is preferable that the resin film satisfies all of the following optical properties (ii-1) to (ii-6). (ii-1) Average internal transmittance T at wavelengths of 450 to 580 nm 450-580AVE More than 88% (ii-2) In the wavelength range of 600 to 700 nm, the wavelength at which the internal transmittance is 20% is in the range of 640 to 690 nm. (ii-3) Internal transmittance T at a wavelength of 700 nm 700 Less than 1% (ii-4) Internal transmittance T at a wavelength of 750 nm 750 Less than 10% (ii-5) Internal transmittance T at a wavelength of 800 nm 800 Less than 20% (ii-6) Internal transmittance T at a wavelength of 950 nm 950 Between 60% and 95%

[0050] Satisfying the optical characteristic (ii-1) means that the transmittance in the visible light region is high. T 450-580AVE is preferably 89% or more, more preferably 90% or more.

[0051] Satisfying the optical characteristic (ii-2) means that it is possible to compensate for the oblique incidence shift of the dielectric multilayer film, which has excellent transmittance in the red band and excellent light blocking properties in the near-infrared light region with wavelengths of 700 nm and above. The optical property (ii-2) is preferably in the range of 645 to 685 nm, more preferably 650 to 680 nm.

[0052] By satisfying the optical properties (ii-3) to (ii-5), it is possible to block light by absorption in the wavelength range in which light leakage is likely to occur in the dielectric multilayer film. T 700 is preferably 0.9% or less. T 750 is preferably 9.5% or less, more preferably 9% or less. T 800 is preferably 18% or less, more preferably 16% or less.

[0053] The optical property (ii-6) defines the range of transmittance permitted in the long wavelength region. T 950 is preferably 60% or more and 92.5% or less, more preferably 60% or more and 90% or less.

[0054] <NIR dye The NIR dye (IR) is a NIR dye having a maximum absorption wavelength in the range of 680 to 1000 nm in dichloromethane. By containing such a dye, near-infrared light can be effectively cut off.

[0055] The dye (IR) preferably satisfies the following characteristic (iii-1) in the spectral internal transmittance curve measured by dissolving the dye (IR) in the resin so that the internal transmittance at the maximum absorption wavelength in the resin constituting the resin film is 10%. (iii-1) When the maximum absorption wavelength in the resin is D [nm] and the average internal transmittance at 450 to 580 nm is E, E > 100 - (D / 100)

[0056] The dye (IR) has a maximum absorption wavelength in the near-infrared light region. However, the larger the maximum absorption wavelength, the easier it is to absorb visible light, so the transmittance in the visible light region tends to decrease. Characteristic (iii-1) defines the relationship between the maximum absorption wavelength and the lower limit value of the visible light transmittance. Therefore, a dye (IR) that satisfies characteristic (iii-1) means that the visible light transmittance is sufficiently high. Characteristic (iii-1) is more preferably E > 101.5 - (D / 100).

[0057] The NIR dye (IR) may consist of one type of compound or may contain two or more types of compounds. From the viewpoint of easily satisfying the optical characteristics (ii-3) to (ii-6) of the resin film, which widely absorb light in the wavelength range of 700 to 1000 nm, it preferably contains three or more types of compounds having a maximum absorption wavelength in the range of 680 to 1000 nm in dichloromethane. In particular, it is more preferable to contain at least one type of compound selected from each of the following compounds (A) to (C). Compound (A): A compound having a maximum absorption wavelength in the range of 690 nm or more and less than 735 nm in dichloromethane Compound (B): A compound having a maximum absorption wavelength in dichloromethane at a wavelength of 735 nm or more and less than 835 nm. Compound (C): A compound having a maximum absorption wavelength in dichloromethane of 900 nm or more and 1000 nm or less.

[0058] In addition, the maximum difference between the maximum absorption wavelength of compound (A) and the maximum absorption wavelength of compound (B) is preferably 40 nm or more, more preferably 50 nm or more, so that the wavelength range in which light leakage through the dielectric multilayer film is likely to occur can be efficiently blocked by absorption.

[0059] From the viewpoints of transmittance in the visible light range, solubility in resin, and durability, it is preferred that compound (A) is selected from one or more squarylium compounds or cyanine compounds, compound (B) is selected from one or more squarylium compounds or cyanine compounds, and compound (C) is selected from one or more squarylium compounds, cyanine compounds, and immonium compounds.

[0060] <Squarylium compounds> The squarylium compound is preferably a compound represented by the following formula (I), a compound represented by formula (II) described below, or a compound represented by formula (V) described below. When two or more identical symbols are present in a squarylium compound, those symbols may be the same or different. The same applies to cyanine compounds.

[0061] <Squarylium Compounds (I)>

[0062] [ka]

[0063] Here, the symbols in the above formula are as follows: R 24 and R 26each independently represents a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group or an alkoxy group having 1 to 20 carbon atoms, an acyloxy group having 1 to 10 carbon atoms, an aryl group having 6 to 11 carbon atoms, 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, -NR 27 R 28 (R 27 and R 28 are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, -C(=O)-R 29 (R 29 represents a hydrogen atom, a halogen atom, a hydroxyl group, a hydrocarbon group having 1 to 25 carbon atoms which may have a substituent and which may contain an unsaturated bond between carbon atoms, an oxygen atom, or a saturated or unsaturated ring structure), -NHR 30 , or -SO2-R 30 (R 30 represents 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.

[0064] [ka]

[0065] R 21 and R 22 , R 22 and R 25 , and R 21 and R 23 may be linked to each other to form, together with the nitrogen atom, a 5- or 6-membered heterocycle A, heterocycle B, and heterocycle C, respectively. R when heterocycle A is formed 21 and R 22represents 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. 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 2 are groups represented by the following formula (1x) or (2x), and Y 1 and Y 2 Each of X is a group selected from the following formulas (1y) to (5y). 1 and X 2 are groups represented by the following formula (2x), Y 1 and Y 2 may each be a single bond, in which case: An oxygen atom may be present between the carbon atoms.

[0066] [ka]

[0067] 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 37represents an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms. R 27 , R 28 , R 29 , R 31 ~R 37 , R when not forming a heterocycle 21 ~R 23 , and R 25 may be bonded to any other of these to form a 5- or 6-membered ring. 31 and R 36 , R 31 and R 37 may be directly bonded. When R does not form a heterocycle 21 , R 22 , R 23 and R 25 each independently represents a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group or an alkoxy group having 1 to 20 carbon atoms, an acyloxy group having 1 to 10 carbon atoms, an aryl group having 6 to 11 carbon atoms, or an araryl group having 7 to 18 carbon atoms which may have a substituent and which may have an oxygen atom between the carbon atoms.

[0068] Examples of compound (I) include compounds represented by any of formulas (I-1) to (I-3). From the viewpoints of solubility in a resin, heat resistance and light resistance in a resin, and the visible light transmittance of a resin layer containing the compound, the compound represented by formula (I-1) is particularly preferred.

[0069] [ka]

[0070] The symbols in formulae (I-1) to (I-3) have the same definitions as those of the same symbols in formula (I), and preferred embodiments are also the same.

[0071] 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 ~R36 is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, 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).

[0072] -C(CH3)2-CH(CH3)- …(11-1) -C(CH3)2-CH2- …(11-2) -C(CH3)2-CH(C2H5)- …(11-3) -C(CH3)2-C(CH3)(nC3H7)- …(11-4) -C(CH3)2-CH2-CH2- …(12-1) -C(CH3)2-CH2-CH(CH3)- …(12-2) -C(CH3)2-CH(CH3)-CH2- …(12-3)

[0073] In addition, in compound (I-1), R 21 From the viewpoints of solubility, heat resistance, and the steepness of the change in the spectral transmittance curve near the boundary between the visible region and the near infrared region, each of the formulas (4-1) or (4-2) is more preferred.

[0074] [ka]

[0075] 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.

[0076] In compound (I-1), R 24 Ha-NR 27 R 28 -NR 27 R 28 From the viewpoint of solubility in resins and coating solvents, -NH-C(=O)-R 29 or -NH-SO2-R30 is preferred.

[0077] In compound (I-1), R 24 -NH-C(=O)-R 29 The compound is shown in formula (I-11).

[0078] [ka]

[0079] R 23 and R 26 are each preferably independently a hydrogen atom, a halogen atom, or an alkyl or alkoxy group having 1 to 6 carbon atoms, and more preferably a hydrogen atom.

[0080] R 29 Preferred examples of the group include an alkyl group having 1 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 10 carbon atoms which may have a substituent, or an araryl group having 7 to 18 carbon atoms which may have a substituent and which may have an oxygen atom between the carbon atoms. Examples of the substituent include a hydroxyl group, a carboxy group, a sulfo group, a cyano group, an alkyl group having 1 to 6 carbon atoms, a fluoroalkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and an acyloxy group having 1 to 6 carbon atoms.

[0081] R 29 is preferably a group selected from a linear, branched or cyclic alkyl group having 1 to 17 carbon atoms, a phenyl group which may be substituted with an alkoxy group having 1 to 6 carbon atoms, and an araryl group having 7 to 18 carbon atoms which may have an oxygen atom between the carbon atoms.

[0082] R 29 As the alkyl group, 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 a hydroxyl group, a carboxy group, a sulfo group, or a cyano group, and which may contain an unsaturated bond, an oxygen atom, or a saturated or unsaturated ring structure between carbon atoms, can also be preferably used.

[0083] More specifically, examples of compound (I-11) include the compounds shown in the following table. In addition, in the compounds shown in the following table, the meanings of the symbols on the left and right of the squarylium skeleton are the same.

[0084] [Table 1]

[0085] Of these, compounds (I-11-11) to (I-11-15) and (I-11-26) to (I-11-30) are preferred as compound (I-11) from the standpoint of transmittance in the visible light region and solubility in resins.

[0086] In compound (I-1), R 24 -NH-SO2-R 30 The compound is shown in formula (I-12).

[0087] [ka]

[0088] R 23 and R 26 are each preferably independently a hydrogen atom, a halogen atom, or an alkyl or alkoxy group having 1 to 6 carbon atoms, and more preferably a hydrogen atom.

[0089] R 30 From the viewpoint of light resistance, R is preferably an alkyl group or alkoxy group having 1 to 12 carbon atoms, which may have a branch, or a hydrocarbon group having 6 to 16 carbon atoms and an unsaturated ring structure. Examples of the unsaturated ring structure include benzene, toluene, xylene, furan, and benzofuran. 30 are more preferably independently an alkyl or alkoxy group having 1 to 12 carbon atoms which may have a branch. 30 In each of the groups represented by the following formula (I), some or all of the hydrogen atoms may be substituted by halogen atoms, particularly fluorine atoms.

[0090] More specifically, compound (I-12) includes the compounds shown in the following table. In the compounds shown in the following table, the symbols on the left and right of the squarylium skeleton have the same meaning.

[0091] [Table 2]

[0092] Of these, compounds (I-12-11) to (I-12-15) and (I-12-26) to (I-12-30) are preferred as compound (I-12) from the standpoint of transmittance in the visible light region and solubility in resins.

[0093] <Squarylium Compounds (II)>

[0094] [ka]

[0095] Here, the symbols in the above formula are as follows: Each ring Z is independently a 5- or 6-membered ring having 0 to 3 heteroatoms in the ring, and the hydrogen atoms in ring Z may be substituted. R 1 and R 2 , R 2 and R 3 , and R 1 The carbon atoms or heteroatoms constituting the ring Z may be bonded to each other to form a heterocycle A1, a heterocycle B1, or a heterocycle C1 together with the nitrogen atom, and in that case, the hydrogen atoms of the heterocycle A1, the heterocycle B1, or the heterocycle C1 may be substituted. 1 and R 2 R each independently represents a hydrogen atom, a halogen atom, or a hydrocarbon group which may contain an unsaturated bond between carbon atoms, a heteroatom, or a saturated or unsaturated ring structure and which may have a substituent. 4 and R when not forming a heterocycle 3each independently represents a hydrogen atom, a halogen atom, or an alkyl or alkoxy group which may contain a heteroatom between carbon atoms and which may have a substituent.

[0096] Examples of compound (II) include compounds represented by any of formulas (II-1) to (II-3). From the viewpoints of solubility in a resin and visible light transmittance in a resin, the compound represented by formula (II-3) is particularly preferred.

[0097] [ka]

[0098] In formula (II-1) and formula (II-2), R 1 and R 2 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 15 carbon atoms which may have a substituent; R 3 ~R 6 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 10 carbon atoms which may have a substituent.

[0099] In formula (II-3), R 1 , R 4 , and R 9 ~R 12 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 15 carbon atoms which may have a substituent; R 7 and R 8 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 5 carbon atoms which may have a substituent.

[0100] R in compound (II-1) and compound (II-2) 1 and R 2 From the viewpoints of solubility in a resin, visible light transmittance, and the like, each independently represents preferably an alkyl group having 1 to 15 carbon atoms, more preferably an alkyl group having 7 to 15 carbon atoms; R 1 and R 2 More preferably, at least one of R is a branched alkyl group having 7 to 15 carbon atoms.1 and R 2 It is particularly preferable that both of the groups are alkyl groups having a branched chain and having 8 to 15 carbon atoms.

[0101] R in compound (II-3) 1 From the viewpoints of solubility in transparent resins, visible light transmittance, and the like, each independently is preferably an alkyl group having 1 to 15 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms, and particularly preferably an ethyl group or an isopropyl group.

[0102] R 4 From the viewpoints of visible light transmittance and ease of synthesis, is preferably a hydrogen atom or a halogen atom, and particularly preferably a hydrogen atom. R 7 and R 8 are each preferably a hydrogen atom, a halogen atom, or an alkyl group having 1 to 5 carbon atoms which may be substituted with a halogen atom, and more preferably a hydrogen atom, a halogen atom, or a methyl group.

[0103] R 9 ~R 12 are preferably independently a hydrogen atom, a halogen atom, or an alkyl group having 1 to 5 carbon atoms which may be substituted by a halogen atom. -CR 9 R 10 -CR 11 R 12 Examples of - include divalent organic groups represented by the following groups (13-1) to (13-5). -CH(CH3)-C(CH3)2- …(13-1) -C(CH3)2-CH(CH3)- …(13-2) -C(CH3)2-CH2- …(13-3) -C(CH3)2-CH(C2H5)- …(13-4) -CH(CH3)-C(CH3)(CH2-CH(CH3)2)-…(13-5)

[0104] More specifically, examples of compound (II-3) include the compounds shown in the following table. In the compounds shown in the following table, the symbols on the left and right of the squarylium skeleton have the same meaning.

[0105] [Table 3]

[0106] Compounds (I) to (II) can be produced by known methods. Compound (I) can be produced by the methods described in U.S. Pat. No. 5,543,086, U.S. Patent Application Publication No. 2014 / 0061505, and WO 2014 / 088063. Compound (II) can be produced by the methods described in WO 2017 / 135359.

[0107] <Cyanine compounds> The cyanine compound is preferably a compound represented by the following formula (III) or formula (IV).

[0108] <Cyanine compounds (III) and (IV)>

[0109] [ka]

[0110] Here, the symbols in the above formula 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 having 1 to 15 carbon atoms which may have a substituent, or an aryl group having 5 to 20 carbon atoms. 110 ~R 114 and R 132 ~R 136 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 15 carbon atoms. X - indicates a monovalent anion. n1 and n2 are 0 or 1. -(CH2) n1 Carbocycles containing - and -(CH2) n2A 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.

[0111] In the above, the alkyl group (including the alkyl group of the alkoxy group) may be linear or may have a branched structure or a saturated ring structure. The aryl group refers to a group that bonds via a carbon atom constituting an aromatic ring of an aromatic compound, such as a benzene ring, a naphthalene ring, a biphenyl, a furan ring, a thiophene ring, a pyrrole ring, etc. Examples of the substituent in the alkyl group or alkoxy group having 1 to 15 carbon atoms or the aryl group having 5 to 20 carbon atoms that may have a substituent include a halogen atom and an alkoxy group having 1 to 10 carbon atoms.

[0112] In formula (III) and formula (IV), R 101 and R 121 is preferably an alkyl group having 1 to 15 carbon atoms or an aryl group having 5 to 20 carbon atoms, and more preferably a branched alkyl group having 1 to 15 carbon atoms from the viewpoint of maintaining a high visible light transmittance in the resin.

[0113] In formula (III) and formula (IV), 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.

[0114] In formula (III) and formula (IV), 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.

[0115] 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.

[0116] X - As for I - , BF4 - , PF6 - , ClO4 - , anions represented by formulas (X1) and (X2), etc., preferably BF4 - , or PF6 - It is.

[0117] [ka]

[0118] In the following description, R 101 ~R 114 The portion excluding is also called skeleton (III). The same applies to compound (IV).

[0119] In the formula (III), a compound in which n1 is 1 is shown in the following formula (III-1), and a compound in which n1 is 0 is shown in the following formula (III-2).

[0120] [ka]

[0121] In formula (III-1) and formula (III-2), R 101 ~R 114 and X - is the same as in formula (III). 115 ~R120 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 ~R 120 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.

[0122] In the formula (IV), a compound in which n2 is 1 is shown in the following formula (IV-1), and a compound in which n2 is 0 is shown in the following formula (IV-2).

[0123] [ka]

[0124] In formula (IV-1) and formula (IV-2), R 121 ~R 136 and X - is the same as in formula (IV). 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.

[0125] More specifically, the compounds represented by formula (III-1), formula (III-2), formula (IV-1), and formula (IV-2) each include compounds in which the atom or group bonded to each skeleton is an atom or group shown in the following table. In all of the compounds shown in the following table, R 101 ~R 109 are all the same on the left and right sides of the formula. In all the compounds shown in the table below, R 121 ~R 131 is identical on both sides of the equation.

[0126] R in the table below 110 -R 114 and R in the table below 132 -R 136 R indicates an atom or group bonded to the central benzene ring of each formula, and when all five are hydrogen atoms, it is written as "H". 110 -R 114 When one of the groups is a substituent and the other is a hydrogen atom, only the combination of the symbol and the substituent is described. For example, "R 112 -C(CH3)3" is R 112 R is -C(CH3)3 and the rest are hydrogen atoms. 132 -R 136 The same applies to.

[0127] R in Table 4 115 -R 120 and R in Table 6 137 -R 142 R represents an atom or group bonded to the central cyclohexane ring in formula (III-1) or formula (IV-1), and when all six are hydrogen atoms, it is written as "H". 115 -R 120 When one of the groups is a substituent and the other is a hydrogen atom, only the combination of the symbol and the substituent is shown. 137 -R 142 The same applies to.

[0128] R in Table 5 115 -R 118 and R in Table 7 137 -R 140R represents an atom or group bonded to the central cyclopentane ring in formula (III-2) or formula (IV-2), and when all four are hydrogen atoms, it is written as "H". 115 -R 118 When one of the groups is a substituent and the other is a hydrogen atom, only the combination of the symbol and the substituent is shown. 137 -R 140 The same applies to.

[0129] In the table below, X - However, in all compounds, X - is BF4 - or PF6 - It is.

[0130] [Table 4]

[0131] Of these, the compounds (III-1) are preferably the compounds (III-1-1) to (III-1-5) from the viewpoints of transparency in the visible light region and solubility in resins.

[0132] [Table 5]

[0133] Of these, the compounds (III-2-1) to (III-2-5) are preferred as the compound (III-2) from the viewpoints of transparency in the visible light region and solubility in resins.

[0134] [Table 6]

[0135] Of these, the compounds (IV-1) are preferably the compounds (IV-1-1) to (IV-1-5) from the viewpoints of transparency in the visible light region and solubility in resins.

[0136] [Table 7]

[0137] Of these, the compounds (IV-2) are preferably the compounds (IV-2-1) to (IV-2-5) from the viewpoints of transparency in the visible light region and solubility in resins.

[0138] As described above, the skeletons of the compounds (III) and (IV) are different, and therefore the wavelength regions of the absorption maxima are different. In the compound (III), the maximum absorption wavelength is in the wavelength region of about 760 to 830 nm, depending on the types and combinations of atoms and groups bonded to the skeleton. In the compound (IV), the maximum absorption wavelength is in the wavelength region of about 800 to 900 nm, depending on the types and combinations of atoms and groups bonded to the skeleton.

[0139] Furthermore, in compound (III), the maximum absorption wavelength differs between when n1 of the skeleton is 1 and when n1 is 0. Although it depends on the types and combinations of atoms and groups bonded to the skeleton, when n1 is 1, the maximum absorption wavelength is in the wavelength region of about 760 to 800 nm, and when n1 is 0, the maximum absorption wavelength is in the wavelength region of about 800 to 830 nm.

[0140] Similarly, in compound (IV), the maximum absorption wavelength differs between when n2 is 1 and when n2 is 0. Although it depends on the types and combinations of atoms and groups bonded to skeleton (IV-1), when n2 is 1, the maximum absorption wavelength is in the wavelength region of about 800 to 830 nm, and when n2 is 0, the maximum absorption wavelength is in the wavelength region of about 830 to 900 nm.

[0141] Compound (III) and compound (IV) can be produced, for example, by the methods described in Dyes and pigments 73 (2007) 344-352 and J. Heterocyclic chem, 42, 959 (2005).

[0142] <Squarylium Compounds (V)>

[0143] [ka]

[0144] In formula (V), R 51 ~R 54 are each independently a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group, an aryl group, or an araryl group. The alkyl group, aryl group or araryl group may have a substituent. In addition, the alkyl group, aryl group, or araryl group may contain an unsaturated bond, an oxygen atom, an ester bond, an amide bond, or a thioamide bond between carbon atoms. Furthermore, the alkyl group, aryl group, or araryl group may have an oxygen atom, an ester bond, an amide bond, or a thioamide bond at the end bonding to the thiophene ring. R 51 and R 52 , R 52 and R 53 , and R 53 and R 54 may be linked to each other to form a monocycle or a polycycle having 2 to 4 condensed rings, in which case a hydrogen atom bonded to the ring may be substituted with a substituent.

[0145] Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms. Fluorine and chlorine atoms are preferred.

[0146] R 51 ~R 54 When the alkyl group is an alkyl group, it preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and further preferably 1 to 12 carbon atoms. R 51 ~R 54 When the aryl group is an aryl group, it preferably has 4 to 20 carbon atoms, more preferably 4 to 17 carbon atoms, and even more preferably 4 to 14 carbon atoms. R 51 ~R 54 When the aryl group is an araryl group, it preferably has 5 to 20 carbon atoms, more preferably 5 to 18 carbon atoms, and even more preferably 5 to 15 carbon atoms. R51 ~R 54 When the group has a substituent, the number of carbon atoms included in the number of carbon atoms of the substituent.

[0147] R 51 ~R 54 Examples of the substituent in R include a halogen atom, a hydroxyl group, a carboxy group, a sulfo group, a cyano group, an amino group, an N-substituted amino group, a nitro group, an alkoxycarbonyl group, a carbamoyl group, an N-substituted carbamoyl group, an imido group, and an alkoxy group having 1 to 10 carbon atoms. 51 ~R 54 When is an aryl group or an araryl group, the substituent is a hydrogen atom bonded to the aromatic ring or a group substituting a hydrogen atom of an alkyl group contained therein, and further includes an aryl group in addition to the above-mentioned substituents.

[0148] R 51 and R 52 , R 52 and R 53 , and R 53 and R 54 may be linked to each other to form a monocycle or a polycycle having 2 to 4 condensed rings, in which case a hydrogen atom bonded to the ring may be substituted with a substituent.

[0149] R 52 and R 53 When R is linked to R, the squarylium compound (V) contains a structure in which a ring is formed between two thiophene rings and at least three rings are condensed. 52 and R 53 A hydrogen atom bonded to the ring formed by linking may be substituted with a substituent. R 52 and R 53 The substituents that replace the hydrogen atoms bonded to the ring to which R is linked are 51 ~R 54 The substituents of the phenyl group include the same groups as those of the substituents in R 51 ~R 54 The substituents are the same as those in the above.

[0150] R55 and R 56 are each independently an alkyl group or an aryl group which may have a substituent and which may contain an unsaturated bond between carbon atoms, an oxygen atom or a nitrogen atom. 55 and R 56 may be linked to each other to form a 5-10 membered cycloheterocycle together with the nitrogen atom, in which case a hydrogen atom bonded to the ring may be substituted with a substituent.

[0151] R 55 and R 56 The substituents in 51 ~R 54 The substituents are the same as those in R 55 and R 56 When is an araryl group, the alkyl group contained therein may be further substituted with an aryl group.

[0152] R 55 and R 56 In the case of an alkyl group, the number of carbon atoms is preferably 1 to 20, more preferably 1 to 12, and further preferably 1 to 10. 55 and R 56 From the viewpoints of visible light transmittance and solubility in resins and solvents, R is preferably a straight-chain, branched-chain or cyclic alkyl group having 3 to 20 carbon atoms, which may contain an oxygen atom between carbon atoms. The number of carbon atoms in the alkyl group is more preferably 3 to 12 in the case of a straight-chain alkyl group, more preferably 3 to 10 in the case of a branched-chain alkyl group, and more preferably 5 to 10 in the case of a cyclic alkyl group. 15 and R 16 When the group has a substituent, the number of carbon atoms included in the number of carbon atoms of the substituent. R 55 and R 56 is, for example, more preferably a group selected from groups (1a) to (15a), and particularly preferably group (1a).

[0153] [ka]

[0154] R 55 and R 56 may be linked together to form a cyclohetero ring having 5 to 10 members together with the nitrogen atom. The cyclohetero ring may contain an oxygen atom in addition to the nitrogen atom as a ring-constituting element. The number of members of the cyclohetero ring is preferably 5 or 6, and particularly preferably 5. When a hydrogen atom bonded to the cyclohetero ring is substituted, examples of the substituent substituting the hydrogen atom include a halogen atom, a hydroxyl group, an alkyl group or an alkoxy group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, and an aryl group having 7 to 20 carbon atoms.

[0155] R 55 and R 56 When the divalent group to which is bonded is represented by -Q-, specific examples of -Q- include the following groups (11) to (14).

[0156] -(CH2)4- …(11) -(CH2)5- …(12) -C(CH3)2(CH2)2C(CH3)2- …(13) -C(CH3)2(CH2)3C(CH3)2- …(14)

[0157] As the squarylium compound (V), for example, a compound represented by the following formula (V-1) or a compound represented by the following formula (V-2) is preferable. The squarylium compound (V-1) is a squarylium compound (V) in which R 52 and R 53 are linked to form a cyclopentadithiophene ring. The squarylium compound (V-2) is a squarylium compound (V) in which R 52 and R 53 is not linked, but is a compound that contains a structure in which two thiophene rings are bonded together.

[0158] [ka]

[0159] R 51 , R 54 , R55 and R 56 is R in formula (V) 51 , R 54 , R 55 and R 56 The same applies to the preferred embodiments. R 52b and R 53b R in formula (V) except that they are not linked to each other to form a ring. 52 and R 53 The same applies to the preferred embodiments.

[0160] R 52a and R 53a From the viewpoints of visible light transmittance, light resistance, and solubility in resins and solvents, R is preferably a straight-chain, branched-chain, or cyclic alkyl group having 1 to 20 carbon atoms, which may contain an oxygen atom between carbon atoms. The number of carbon atoms in the alkyl group is more preferably 1 to 12 in the case of a straight-chain, more preferably 3 to 10 in the case of a branched-chain, and more preferably 5 to 10 in the case of a cyclic. 52a and R 53a is, for example, more preferably a group selected from the groups (1a) to (15a), and particularly preferably the group (1a), the group (3a), or the group (9a).

[0161] R 52a and R 53a From the viewpoint of transmittance in the visible light region and light resistance, a phenyl group which may have 1 to 5 substituents, a naphthyl group which may have 1 to 7 substituents, or an alkyl group having 1 to 10 carbon atoms is preferred. Examples of the substituent for the phenyl group and naphthyl group include an alkyl group having 1 to 12 carbon atoms, which may contain an unsaturated bond or an oxygen atom between the carbon atoms, an alkoxy group, or an alkylamino group (the alkyl group has 1 to 12 carbon atoms), and in particular, a methyl group, a tertiary butyl group, a dimethylamino group, a methoxy group, etc. are preferred. The phenyl group and naphthyl group are preferably unsubstituted or substituted with 1 to 3 hydrogen atoms.

[0162] Specific examples of the phenyl group which may have 1 to 5 substituents include groups (P1) to (P9).

[0163] [ka]

[0164] Specific examples of the naphthyl group which may have 1 to 7 substituents include groups (N1) to (N9).

[0165] [ka]

[0166] More specifically, examples of compound (V-1) include the compounds shown in the following table. In addition, in the compounds shown in the following table, the meanings of the symbols on the left and right of the squarylium skeleton are the same.

[0167] [Table 8]

[0168] Of these, the compounds (V-1-5), (V-1-12), etc. are preferred as the compound (V-1) from the viewpoints of transparency in the visible light region and solubility in resins.

[0169] More specifically, examples of compound (V-2) include the compounds shown in the following table. In addition, in the compounds shown in the following table, the meanings of the symbols on the left and right of the squarylium skeleton are the same.

[0170] [Table 9]

[0171] The squarylium compound (V) can be produced by a known method, for example, the method described in WO 2019 / 230660.

[0172] <Imonium compounds> The immonium compound is preferably a compound represented by the following formula (A1) or formula (A2).

[0173] [ka]

[0174] The symbols in formulae (A1) and (A2) are as follows. R 201 ~R 206 and R 221 ~R 226 are each independently a hydrogen atom, a halogen atom, a sulfo group, a hydroxy group, a cyano group, a nitro group, a carboxyl group, a phosphate group, an alkyl group or an alkoxy group having 1 to 20 carbon atoms which may have an oxygen atom between the carbon atoms and which may be substituted, or an aryl group having 6 to 14 carbon atoms, an aralkyl group having 7 to 14 carbon atoms, or a heterocyclic group having 3 to 14 members which may be substituted, provided that groups in which a substituted or unsubstituted amino group is bonded to a phenyl group are excluded. 201 ~R 206 and R 221 ~R 226 In the formula, two groups bonded to the same nitrogen atom may be bonded to each other to form a heterocycle having 3 to 8 members together with the nitrogen atom, and a hydrogen atom bonded to the ring may be substituted with an alkyl group having 1 to 12 carbon atoms.

[0175] R 207 ~R 218 and R 227 ~R 238 R are each independently a hydrogen atom, a halogen atom, an optionally substituted amino group, an amido group, a cyano group, a nitro group, a carboxyl group, or an optionally substituted alkyl or alkoxy group having 1 to 12 carbon atoms. 207 ~R 218 and R 227 ~R 238In the formula (I), two adjacent groups may be bonded to each other to form a ring having 3 to 8 members together with two carbon atoms of the phenyl group, and a hydrogen atom bonded to the ring may be substituted with an alkyl group having 1 to 12 carbon atoms.

[0176] R 201 ~R 206 and R 221 ~R 226 In the above formula, examples of the substituent in the optionally substituted alkyl or alkoxy group having 1 to 20 carbon atoms, the optionally substituted aryl group having 6 to 14 carbon atoms, the aralkyl group having 7 to 14 carbon atoms, or the heterocyclic group having 3 to 14 members include a halogen atom, a hydroxyl group, an amino group which may be substituted with an alkyl group having 1 to 6 carbon atoms, a carboxyl group, a sulfo group, a cyano group, and an acyloxy group having 1 to 6 carbon atoms.

[0177] R when not forming a ring 207 ~R 218 and R 227 ~R 238 are each independently preferably a hydrogen atom, a halogen atom, or an alkyl or alkoxy group having 1 to 12 carbon atoms. The alkyl or alkoxy group preferably has 1 to 6 carbon atoms, and more preferably has 1 to 4 carbon atoms.

[0178] R 207 ~R 218 and R 227 ~R 238 In the above formula, the ring formed by bonding two adjacent groups together with the two carbon atoms of the phenyl group may be an alicyclic ring, an aromatic ring, or a heterocyclic ring. Examples of heteroatoms include a nitrogen atom, an oxygen atom, and a sulfur atom.

[0179] R 207 ~R 218 and R 227 ~R 238 In the formula (A1) and the formula (A2), there are six combinations in total in which two adjacent groups are bonded to each other, two for each of the three phenyl groups bonded to the central nitrogen atom.207 and R 208 , R 209 and R 210 , R 211 and R 212 , R 213 and R 214 , R 215 and R 216 , R 217 and R 218 In formula (A2), R 227 and R 228 , R 229 and R 230 , R 231 and R 232 , R 233 and R 234 , R 235 and R 236 , R 237 and R 238 There are six groups:

[0180] R in formula (A1) 207 ~R 218 and R in formula (A2) 227 ~R 238 In the formula, the number of pairs of adjacent groups bonded may be one or more, or up to six pairs may be bonded. It is preferable that three pairs, one pair each for each of the three phenyl groups, are bonded to each other.

[0181] Specific examples of the divalent group formed by bonding two adjacent groups include alkylene groups having 1 to 6 carbon atoms, which may contain 1 to 2 nitrogen atoms as heteroatoms and may have an unsaturated bond between atoms. More specific examples include the following groups (X-1) to (X-4). The hydrogen atoms of these divalent groups may be substituted with alkyl groups having 1 to 12 carbon atoms.

[0182] -(CH2) n -(n is an integer between 1 and 6) ... (X-1) -CH=CH-CH=CH- … (X-2) -CH2-CH=CH- …(X-3) -N=CH-NH- … (X-4)

[0183] R207 ~R 218 and R 227 ~R 238 are each independently preferably a hydrogen atom, a halogen atom, or an alkyl or alkoxy group having 1 to 12 carbon atoms, and more preferably a hydrogen atom, or an alkyl or alkoxy group having 1 to 12 carbon atoms. The number of carbon atoms in the alkyl or alkoxy group is preferably 1 to 6, and more preferably 1 to 4.

[0184] Also, R 201 and R 207 , R 202 and R 210 , R 203 and R 211 , R 204 and R 214 , R 205 and R 215 , R 206 and R 218 , R 221 and R 227 , R 222 and R 230 , R 223 and R 231 , R 224 and R 234 , R 225 and R 235 , R 226 and R 238 may be bonded to each other to form a 4-8 membered heterocycle together with the nitrogen atom bonded to the phenyl group and two carbon atoms of the phenyl group, and a hydrogen atom bonded to the ring may be substituted by an alkyl group having 1 to 12 carbon atoms. Xa - and Xb - each independently represents a monovalent anion.

[0185] In the above, the alkyl group may be linear, branched, cyclic, or a combination of these structures. The same applies to the alkyl group when the aryl group below has an alkyl group, and the alkyl group of the aralkyl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and the fluorine atom and the chlorine atom are preferred.

[0186] In the above, the aryl group refers to a group that bonds via a carbon atom constituting an aromatic ring (not including a heteroatom) possessed by an aromatic compound, such as a benzene ring, a naphthalene ring, biphenyl, etc. The aryl group includes a structure in which a hydrogen atom bonded to a ring-constituting atom other than the carbon atom that contributes to the bond is substituted with an alkyl group, such as a tolyl group or a xylyl group.

[0187] In the above, the aralkyl group refers to a group in which an alkyl group is bonded to an aromatic ring (not including a heteroatom) via a carbon atom constituting the alkyl group. The aralkyl group includes a structure in which a hydrogen atom bonded to a ring-constituting atom other than the atom to which the alkyl group is bonded that contributes to the bond is substituted with an alkyl group.

[0188] In the above, the heterocyclic group is a group in which the atoms constituting the ring are bonded via an atom constituting an alicyclic ring or an aromatic ring composed of carbon atoms and atoms other than carbon atoms. The heterocyclic group includes a structure in which a hydrogen atom bonded to a ring-constituting atom other than the atom contributing to the bond is substituted with an alkyl group. The atom other than carbon atoms contained in the heterocyclic ring includes an oxygen atom, a nitrogen atom, or a sulfur atom, and the number of atoms is preferably 1 to 2.

[0189] Xa - and Xb - As for each independently, Cl - , Br - , I - , F - , ClO4 - , BF4 - , PF6 - , SbF6 - , CF3SO3 - , CH3C6H4SO3 - , N[SO2R f ]2 - , C[SO2R f ]3 - etc.

[0190] Here, R fis a fluoroalkyl group having 1 to 4 carbon atoms, preferably a fluoroalkyl group having 1 to 2 carbon atoms, and more preferably a fluoroalkyl group having 1 carbon atom. When the number of carbon atoms is within the above range, durability such as heat resistance and moisture resistance, and solubility in organic solvents described below are good. f Examples of the alkyl group include perfluoroalkyl groups such as -CF3, -C2F5, -C3F7, and -C4F9, -C2F4H, -C3F6H, and -C2F8H.

[0191] From the viewpoint of moisture resistance, the fluoroalkyl group is preferably a perfluoroalkyl group, and more preferably a trifluoromethyl group.

[0192] Xa - and Xb - As for each, independently, I - , B.F. 4- , SbF6 - , PF6 - , ClO4 - , N[SO2CF3]2 - , C[SO2CF3]3 - etc. are preferred, and SbF6 is preferred because the difference in optical properties between the dichloromethane solution and the resin is small. - , PF6 - and N[SO2CF3]2 - More preferably, SbF6 - , N[SO2CF3]2 - is particularly preferred. From the viewpoint of light durability, BF 4- , PF6 - , N[SO2CF3]2 - is preferred.

[0193] The content of the NIR dye (IR) in the resin film is preferably 0.1 to 25 parts by mass, more preferably 0.3 to 15 parts by mass, based on 100 parts by mass of the resin. When two or more types of compounds are combined, the above content is the total of the respective compounds. In addition, when the NIR dye (IR) contains the compounds (A) to (C), the content of the compound (A) is preferably 0.1 to 5 parts by mass, the content of the compound (B) is preferably 0.1 to 5 parts by mass, and the content of the compound (C) is preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the resin.

[0194] <Other dyes> The resin film may contain other dyes, such as UV dyes, in addition to the NIR dye. Specific examples of UV dyes include oxazole-based, merocyanine-based, cyanine-based, naphthalimide-based, oxadiazole-based, oxazine-based, oxazolidine-based, naphthalic acid-based, styryl-based, anthracene-based, cyclic carbonyl-based, and triazole-based dyes. The UV dye may be used alone or in combination of two or more kinds.

[0195] <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 (IR). When the substrate has a multi-layer structure, it is preferably a composite substrate having a resin film containing an NIR dye (IR) 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.

[0196] The resin is not limited as long as it is a transparent resin, 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, polyparaphenylene resin, polyarylene ether phosphine oxide resin, polyamide resin, polyimide resin, polyamideimide resin, polyolefin resin, cyclic olefin resin, polyurethane resin, polystyrene resin, etc. may be used. One of these resins may be used alone, or two or more may be used in combination. From the viewpoints of the optical properties, glass transition point (Tg) and adhesion of the resin film, one or more resins selected from polyimide resins, polycarbonate resins, polyester resins and acrylic resins are preferred.

[0197] When a plurality of compounds are used as the NIR dye (IR) or other dyes, these may be contained in the same resin film, or each may be contained in a separate resin film.

[0198] As the transparent inorganic material, glass or a crystalline material is preferable. Examples of glass that can be used for the support include absorption-type glass (near-infrared absorbing glass) containing copper ions in fluorophosphate glass or phosphate glass, soda-lime glass, borosilicate glass, alkali-free glass, and quartz glass. As the glass, phosphate glass and fluorophosphate glass are preferable from the viewpoint of absorbing infrared light (particularly 900 to 1200 nm). Note that "phosphate glass" also includes silicophosphate glass, in which part of the glass skeleton is composed of SiO2.

[0199] 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.

[0200] Examples of crystalline materials that can be used for the support include birefringent crystals such as quartz, lithium niobate, and sapphire.

[0201] As the support, from the viewpoint of shape stability related to long-term reliability of optical properties, mechanical properties, etc., and handling properties during filter production, inorganic materials are preferred, and glass and sapphire are particularly preferred.

[0202] The resin film can be formed by dissolving or dispersing the dye (IR), 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 this 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.

[0203] 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.

[0204] 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 (IR), 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 the dye (IR) 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.

[0205] 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.

[0206] When the substrate has a single-layer structure (resin substrate) made of a resin film containing a dye (IR), the thickness of the resin film is preferably 20 to 150 μm. When the substrate is a multi-layer structure (composite substrate) having a support and a resin film containing a dye (IR) laminated on at least one main surface of the support, the thickness of the resin film is preferably 0.3 to 20 μm. When the optical filter has two or more resin films, the total thickness of the resin films is preferably within the above range.

[0207] 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 element. 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 50 to 300 μm.

[0208] 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 blocking infrared light is required. EXAMPLES

[0209] Next, the present invention will be described more specifically with reference to examples. The optical properties were measured using an ultraviolet-visible spectrophotometer (UH-4150, manufactured by Hitachi High-Technologies Corporation). In addition, the optical properties when the incident angle is not specifically specified are the values measured at an incident angle of 0 degrees (the direction perpendicular to the main surface of the optical filter).

[0210] The dyes used in each example are as follows. Compound 1 (squarylium compound): Synthesized based on U.S. Patent Application Publication No. 2014 / 0061505 and International Publication No. 2014 / 088063. Compound 2 (phthalocyanine compound): Synthesized based on Japanese Patent No. 4081149. Compound 3 (squarylium compound): Synthesized based on International Publication No. 2017 / 135359. Compounds 4 to 6 (cyanine compounds): Synthesized based on Dyes and pigments 73(2007) 344 - 352. Compound 7 (squarylium compound): Synthesized based on International Publication No. 2019 / 230660. Compound 8 (diimonium compound): Synthesized based on Japanese Unexamined Patent Application Publication No. 2014 - 25016.

[0211] [Chemical formula]

[0212] [Chemical formula]

[0213] <Optical properties of IR dyes> Polyimide resin (C - 3G30G manufactured by Mitsubishi Gas Chemical) was dissolved in an organic solvent (cyclohexanone:γ - butyrolactone = 1:1 mass ratio) at a concentration of 8.5 mass%. To the solution of the polyimide resin prepared above, each dye compound was added in an amount of 6 parts by mass per 100 parts by mass of the resin, and the mixture was stirred for 2 hours while heating at 50°C. The dye - containing resin solution was applied to a glass substrate (alkali glass, D263 manufactured by Schott) and dried to obtain a resin film (coated film) with a thickness of 1 μm. Using the spectral transmittance curve and the spectral reflectance curve of this resin-coated glass plate, a spectral internal transmittance curve was calculated and normalized so that the transmittance at the maximum absorption wavelength was 10%. The optical properties are shown in the table below.

[0214] [Table 10]

[0215] <Example 1-1 to Example 1-5: Optical properties of resin film> A polyimide resin (C-3G30G manufactured by Mitsubishi Gas Chemical Co., Ltd.) was dissolved in an organic solvent (cyclohexanone:γ-butyrolactone=1:1 mass ratio) at a concentration of 8.5 mass %. To the polyimide resin solution prepared above, each compound was added in an amount (parts by mass) shown in the table below relative to 100 parts by mass of the resin, and the mixture was stirred for 2 hours while heating to 50°C. The dye-containing resin solution was applied to a glass substrate (alkali glass, D263 manufactured by Schott) and dried to obtain a resin film (coated film) having a thickness of 2 μm. The obtained resin film was measured for transmission spectroscopy at an incident direction of 0° and reflection spectroscopy at an incident direction of 5° in the wavelength range of 350 nm to 1200 nm. The transmittance is expressed as the internal transmittance represented by the following formula. Internal transmittance = measured transmittance / (100-reflectance)*100 The optical properties are shown in the table below. Incidentally, Examples 1-1 to 1-5 are reference examples.

[0216] [Table 11]

[0217] Examples 1-1 to 1-3 have high visible light transmittance because only the amount of dye necessary to absorb light in the near-infrared region where light leakage can occur in the multilayer film is blended. In Example 1-4, the amount of dye blended is small, so the near-infrared light region, which can cause light leakage in the multilayer film, is not fully absorbed. Example 1-5 has a wide absorption band in the near infrared region, but a low visible light transmittance. This is thought to be because the amount of dye added was increased to broaden the absorption band, resulting in absorption in the visible region as well.

[0218] <Example 2-1 to Example 2-2: Optical properties of dielectric multilayer film> We designed dielectric multilayer film 1 with a total thickness of 3.94 μm, which is made by stacking 32 TiO2 and SiO2 films alternately, and dielectric multilayer film 2 with a total thickness of 4.94 μm, which is made by stacking 40 layers. The optical characteristics of the dielectric multilayer film 1 and the dielectric multilayer film 2 are shown in the table below. The spectral transmittance curves of the dielectric multilayer film 1 and the dielectric multilayer film 2 are shown in FIG. 5 and FIG. It should be noted that Examples 2-1 and 2-2 are reference examples.

[0219] [Table 12]

[0220] The dielectric multilayer film 1 has small ripples, but light leakage occurs at wavelengths of 780 nm and above. The dielectric multilayer film 2 has large ripples, but almost no light leakage occurs at wavelengths of 780 nm and above.

[0221] <Example 3-1: Optical characteristics of optical filters> The dielectric multilayer film 1 of Example 2-1 was laminated on the main surface of a glass substrate (alkali glass, D263 manufactured by Schott). The resin film of Example 1-1 was formed on the other main surface of the glass substrate by spin coating, and a dielectric multilayer film (anti-reflection film) in which SiO2 and TiO2 were alternately laminated was formed on the resin film by deposition, to produce an optical filter 1.

[0222] <Example 3-2: Optical characteristics of optical filters> An optical filter 2 was produced in the same manner as in Example 3-1, except that the dielectric multilayer film 2 of Example 2-2 was laminated instead of the dielectric multilayer film 1 of Example 2-1.

[0223] <Example 3-3: Optical characteristics of optical filters> An optical filter 3 was produced in the same manner as in Example 3-1, except that the resin film of Example 1-5 was formed instead of the resin film of Example 1-1.

[0224] The optical characteristics of the optical filters 1 to 3 are shown in the table below. Example 3-1 is an embodiment, and Examples 3-2 and 3-3 are comparative examples.

[0225] [Table 13]

[0226] The optical filter of Example 3-1 had high visible light transmittance, small ripples at a high incident angle of 40 degrees, and was able to block light in the long wavelength region including the near infrared region of 750 to 1000 nm. In the optical filter of Example 3-2, the dielectric multilayer film had a large incidence angle dependency, and low ripples could not be achieved at a high incidence angle of 40 degrees. In the optical filter of Example 3-3, the visible light transmittance was significantly reduced due to excessive absorption by the dye. [Industrial Applicability]

[0227] The optical filter of the present invention has excellent visible light transmittance and good near-infrared light shielding properties in which changes in the near-infrared light shielding properties at high incidence angles are suppressed. The optical filter 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]

[0228] 1A, 1B, 1C, 1D...optical filter, 10...substrate, 11...support, 12...resin film, 30...dielectric multilayer film

Claims

1. An optical filter comprising a substrate and a dielectric multilayer film laminated on at least one main surface side of the substrate, the substrate has at least one resin film containing a dye (IR) and a resin; The total thickness of the resin film is 0.3 to 20 μm, The optical filter satisfies all of the following optical properties (i-1), (i-2), (i-4), and (i-7) to (i-10). (i-1) On at least one surface of the optical filter, the average reflectance R at a wavelength of 450 to 500 nm and an incident angle of 5 degrees ４５０－５００（５ｄｅｇ）ＡＶＥ is 3% or less, and the average reflectance R at an incident angle of 40 degrees ４５０－５００（４０ｄｅｇ）ＡＶＥ Less than 5% (i-2) On at least one surface of the optical filter, the average reflectance R at a wavelength of 500 to 580 nm and an incident angle of 5 degrees ５００－５８０（５ｄｅｇ）ＡＶＥ is 2.5% or less, and the average reflectance R at an incident angle of 40 degrees ５００－５８０（４０ｄｅｇ）ＡＶＥ is 4% or less (i-4) The maximum reflectance R at a wavelength of 450 to 580 nm and an incident angle of 5 degrees on at least one surface of the optical filter ４５０－５８０（５ｄｅｇ）ＭＡＸ is 4% or less, and the maximum reflectance R at an incident angle of 40 degrees ４５０－５８０（４０ｄｅｇ）ＭＡＸ Less than 6% (i-7) Average transmittance T at an incident angle of 0 degrees in the wavelength range of 450 to 580 nm ４５０－５８０（０ｄｅｇ）ＡＶＥ More than 88% (i-8) In the wavelength range of 600 to 800 nm, the absolute value of the difference between the wavelength at which the transmittance is 20% at an incident angle of 0 degrees and the wavelength at which the transmittance is 20% at an incident angle of 40 degrees is 10 nm or less. (i-9) In the wavelength range of 600 to 800 nm, the wavelength at which the transmittance is 20% at an incident angle of 0 degrees is in the range of 640 to 690 nm. (i-10) Maximum transmittance T at an incident angle of 0 degrees in the wavelength range of 750 to 1000 nm ７５０－１０００（０ｄｅｇ）ＭＡＸ is 1% or less, and the maximum transmittance T at an incident angle of 40 degrees ７５０－１０００（４０ｄｅｇ）ＭＡＸ Less than 1%

2. The optical filter according to claim 1 , wherein the optical filter satisfies the following optical characteristic (i-3): (i-3) At least one surface of the optical filter, the R ４５０－５００（５ｄｅｇ）ＡＶＥ > The above R ５００－５８０（５ｄｅｇ）ＡＶＥ And the R ４５０－５００（４０ｄｅｇ）ＡＶＥ > The above R ５００－５８０（４０ｄｅｇ）ＡＶＥ Satisfying the relationship

3. 3. The optical filter according to claim 1, wherein the optical filter satisfies the following optical properties (i-5) and (i-6). (i-5) At a wavelength of 450 to 500 nm, the maximum difference between the transmittance at an incident angle of 0 degrees and the transmittance at an incident angle of 40 degrees is 6% or less. (i-6) At a wavelength of 500 to 580 nm, the maximum difference between the transmittance at an incident angle of 0 degrees and the transmittance at an incident angle of 40 degrees is 5% or less.

4. 4. The optical filter according to claim 1, wherein the resin film satisfies all of the following optical properties (ii-1) to (ii-6): (ii-1) Average internal transmittance T at wavelengths of 450 to 580 nm ４５０－５８０ＡＶＥ More than 88% (ii-2) In the wavelength range of 600 to 700 nm, the wavelength at which the internal transmittance is 20% is in the range of 640 to 690 nm. (ii-3) Internal transmittance T at a wavelength of 700 nm ７００ Less than 1% (ii-4) Internal transmittance T at a wavelength of 750 nm ７５０ Less than 10% (ii-5) Internal transmittance T at a wavelength of 800 nm ８００ Less than 20% (ii-6) Internal transmittance T at a wavelength of 950 nm ９５０ Between 60% and 95%

5. 5. The optical filter according to claim 1, wherein the dielectric multilayer film satisfies all of the following optical properties (iv-1) to (iv-8). (iv-1) Average transmittance T at an incident angle of 0 degrees in the wavelength range of 450 to 580 nm ４５０－５８０（０ｄｅｇ）ＡＶＥ is 90% or more, and the average transmittance T at an incident angle of 40 degrees ４５０－５８０（４０ｄｅｇ）ＡＶＥ More than 90% (iv-2) At wavelengths of 450 to 500 nm, the absolute value of the difference between the average transmittance at an incident angle of 0 degrees and the average transmittance at an incident angle of 40 degrees is 3% or less. (iv-3) At a wavelength of 500 to 580 nm, the absolute value of the difference between the average transmittance at an incident angle of 0 degrees and the average transmittance at an incident angle of 40 degrees is 2% or less. (iv-4) At a wavelength of 450 to 500 nm, the maximum difference between the transmittance at an incident angle of 0 degrees and the transmittance at an incident angle of 40 degrees is 6% or less. (iv-5) At a wavelength of 500 to 580 nm, the maximum difference between the transmittance at an incident angle of 0 degrees and the transmittance at an incident angle of 40 degrees is 5% or less. (iv-6) In the wavelength range of 600 to 800 nm, the wavelength at which the transmittance is 20% at an incident angle of 0 degrees is in the range of 720 to 770 nm. (iv-7) Maximum transmittance T at an incident angle of 0 degrees in the wavelength range of 780 to 850 nm ７８０－８５０（０ｄｅｇ）ＭＡＸ Between 4% and 10% (iv-8) Maximum transmittance T at an incident angle of 40 degrees in the wavelength range of 900 to 980 nm ９００－９８０（４０ｄｅｇ）ＭＡＸ is between 1% and 5%

6. The dye (IR) is A compound (A) having a maximum absorption wavelength in dichloromethane at a wavelength of 690 nm or more and less than 735 nm; A compound (B) having a maximum absorption wavelength in dichloromethane at a wavelength of 735 nm or more and less than 835 nm; 6. The optical filter according to claim 1, comprising at least one compound selected from the group consisting of compounds (C) having a maximum absorption wavelength in dichloromethane in the range of 900 nm to 1000 nm.

7. 7. The optical filter according to claim 6, wherein the maximum difference between the maximum absorption wavelength of said compound (A) and the maximum absorption wavelength of said compound (B) is 40 nm or more.

8. 8. The optical filter according to claim 1, wherein the substrate includes a support and the resin film.

9. 9. The optical filter according to claim 8, wherein the support is any one of fluorophosphate glass, phosphate glass, soda-lime glass, borosilicate glass, alkali-free glass, and quartz glass.

10. 10. The optical filter according to claim 1, comprising one layer of the resin film.

11. 11. The optical filter according to claim 1, comprising two or more layers of the resin film.

12. An information acquisition device comprising the optical filter according to any one of claims 1 to 11.

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