optical filter

Abstract

The present application provides an optical filter having high visible light transmittance and high near-infrared light blocking property, suppressing waviness even under high incident angle conditions, and suppressing changes in near-infrared light blocking property under high incident angle conditions. An optical filter having a substrate and a dielectric multilayer film laminated on at least one main surface side of the above substrate as an outermost layer, wherein the above substrate has a resin film containing a pigment (IR) having a maximum absorption wavelength in the range of 680 nm to 1000 nm in dichloromethane and a resin, and the above optical filter satisfies all of the specific optical properties (i-1) to (i-10) in the spectral transmittance curve under conditions where the incident angle is 0 degrees, 5 degrees, and 40 degrees.

Description

Technical Field

[0001] This invention relates to filters that transmit light in the visible wavelength range and block light in the near-infrared wavelength range. Background Technology

[0002] In imaging devices using solid-state imaging elements, filters are used to transmit light in the visible region (hereinafter also referred to as "visible light") and block light in the ultraviolet wavelength range (hereinafter also referred to as "ultraviolet light") and the near-infrared wavelength range (hereinafter also referred to as "near-infrared light") in order to reproduce colors well and obtain vivid images.

[0003] Such filters include, for example, reflective filters that reflect light that is to be blocked by light interference by alternately stacking dielectric thin films (dielectric multilayer films) with different refractive indices on one or both sides of a transparent substrate.

[0004] For filters with dielectric multilayer films, the optical thickness of the dielectric multilayer film varies with the incident angle of light. This leads to problems such as variations in the spectral transmittance curve dependent on the incident angle, increased light leakage due to increased transmittance of near-infrared light (which should have high reflectivity at high incident angles), and noise generation caused by near-infrared light reflected from the dielectric multilayer film. When using such filters, the spectral sensitivity of solid-state imaging elements may be affected by the incident angle. In particular, it is envisioned that these filters will be used at high incident angles due to the recent trend of increasingly smaller camera modules.

[0005] Furthermore, for dielectric multilayer films, depending on the number of layers, interference caused by reflected light at the interfaces of each layer can lead to drastic changes in transmittance (ripples). Moreover, the larger the angle of incidence, the greater the ripples. Dielectric multilayer films used in filters that transmit light in the visible light wavelength range and block light in the near-infrared wavelength range are designed to transmit visible light and block near-infrared light and subsequent longer wavelengths. However, conventional dielectric multilayer films are designed to suppress light leakage in the near-infrared region, but produce ripples in the visible light region, and the considered angle of incidence is only about 30 degrees.

[0006] Patent document 1 describes a near-infrared cutoff filter that has a dielectric multilayer film and suppresses ripples in the visible light region under high incident angle conditions.

[0007] Patent document 2 describes a filter that reduces incident angle dependence without having a dielectric multilayer film by combining various near-infrared absorbing pigments.

[0008] Existing technical documents

[0009] Patent documents

[0010] [Patent Document 1] Japanese Patent Application Publication No. 2019-120942

[0011] [Patent Document 2] Japanese Patent Application Publication No. 2019-32371 Summary of the Invention

[0012] The problem that the invention aims to solve

[0013] However, regarding the near-infrared cutoff filter described in Patent Document 1, the spectral transmittance curve changes under high incident angle conditions, and the blocking properties in the near-infrared region also change.

[0014] Regarding the filter described in Patent Document 2, visible light is also absorbed by a large amount of pigment used to ensure the blocking effect in the near-infrared region and the angle-dependent effect of incidence, resulting in low transmittance in the visible light region.

[0015] The purpose of this invention is to provide a filter that has high visible light transmittance and high near-infrared light blocking properties, suppresses ripples even under high incident angle conditions, and suppresses changes in near-infrared light blocking properties under high incident angle conditions.

[0016] means for solving problems

[0017] The present invention provides a filter having the following configuration.

[0018] [1] A filter having a substrate and a dielectric multilayer film, wherein the dielectric multilayer film is stacked as the outermost layer on at least one main surface side of the substrate, wherein,

[0019] The aforementioned substrate has a resin film comprising a pigment (IR) and a resin.

[0020] The aforementioned pigments (IR) exhibit maximum absorption wavelengths in dichloromethane within the range of 680 nm to 1000 nm, and

[0021] The above filters satisfy all of the following optical properties (i-1) to (i-10):

[0022] (i-1) The average reflectivity R in the wavelength range of 450nm to 500nm under the condition of an incident angle of 5 degrees. 450-500(5deg)AVE The average reflectance R is less than 3% and under the condition of an incident angle of 40 degrees. 450-500(40deg)AVE Less than 5%;

[0023] (i-2) The average reflectivity R in the wavelength range of 500nm to 580nm under the condition of an incident angle of 5 degrees. 500-580(5deg)AVEThe average reflectance R is less than 2.5% and is obtained under the condition of an incident angle of 40 degrees. 500-580(40deg)AVE Less than 4%;

[0024] (i-3) satisfies the above R 450-500(5deg)AVE >R above 500-580(5deg)AVE And the aforementioned R 450-500(40deg)AVE >R above 500-580(40deg)AVE Relationship;

[0025] (i-4) The maximum reflectivity R in the wavelength range of 450nm to 580nm under the condition of an incident angle of 5 degrees. 450-580(5deg)MAX The maximum reflectivity R is less than 4% and is achieved under the condition of an incident angle of 40 degrees. 450-580(40deg)MAX Below 6%;

[0026] (i-5) In the wavelength range of 450 nm to 500 nm, the maximum difference between the transmittance under the condition of 0 degrees incident angle and the transmittance under the condition of 40 degrees incident angle is less than 6%.

[0027] (i-6) In the wavelength range of 500nm to 580nm, the maximum difference between the transmittance under the condition of 0 degrees of incident angle and the transmittance under the condition of 40 degrees of incident angle is less than 5%.

[0028] (i-7) Average transmittance T in the wavelength range of 450 nm to 580 nm under the condition of 0 degrees incident angle. 450-580(0deg)AVE It is over 88%;

[0029] (i-8) In the wavelength range of 600nm to 800nm, the absolute value of the difference between the wavelength with a transmittance of 20% under the condition of an incident angle of 0 degrees and the wavelength with a transmittance of 20% under the condition of an incident angle of 40 degrees is less than 10nm.

[0030] (i-9) In the wavelength range of 600nm to 800nm, the wavelength of 20% under the condition of 0 degrees incident angle is in the range of 640nm to 690nm.

[0031] (i-10) The maximum transmittance T in the wavelength range of 750 nm to 1000 nm under the condition of an incident angle of 0 degrees. 750-1000(0deg)MAX The maximum transmittance T is less than 1% and is obtained under the condition of an incident angle of 40 degrees. 750-1000(40deg)MAX It is less than 1%.

[0032] Invention Effects

[0033] According to the present invention, a filter can be provided that has high visible light transmittance and high near-infrared light blocking properties, suppresses ripples even under high incident angle conditions, and suppresses changes in near-infrared light blocking properties under high incident angle conditions. Attached Figure Description

[0034] [ Figure 1 ] Figure 1 A cross-sectional view illustrating an example of a filter according to one embodiment.

[0035] [ Figure 2 ] Figure 2 A cross-sectional view illustrating another example of a filter according to one embodiment.

[0036] [ Figure 3 ] Figure 3 A cross-sectional view illustrating another example of a filter according to one embodiment.

[0037] [ Figure 4 ] Figure 4 A cross-sectional view illustrating another example of a filter according to one embodiment.

[0038] [ Figure 5 ] Figure 5 The graph shows the spectral transmittance curve of the dielectric multilayer film 1 in Example 2-1.

[0039] [ Figure 6 ] Figure 6 This is a graph showing the spectral transmittance curve of the dielectric multilayer film 2 in Example 2-2.

[0040] [ Figure 7 ] Figure 7 The graph shows the spectral transmittance curve of the dielectric multilayer film 3 in Example 2-3.

[0041] [ Figure 8 ] Figure 8 The graph shows the spectral transmittance curve of the dielectric multilayer film 4 in Example 2-4.

[0042] Label Explanation

[0043] 1A, 1B, 1C, 1D... Filters, 10... Substrate, 11... Support, 12... Resin film, 30... Dielectric multilayer film Detailed Implementation

[0044] The embodiments of the present invention will be described below.

[0045] In this specification, near-infrared absorbing pigments are sometimes referred to as "NIR pigments" and ultraviolet absorbing pigments are sometimes referred to as "UV pigments".

[0046] In this specification, compounds represented by formula (I) are referred to as compound (I). The same applies to compounds represented by other formulas. Pigments containing compound (I) are also referred to as pigment (I), and the same applies to other pigments. Furthermore, groups represented by formula (I) are also referred to as group (I), and the same applies to groups represented by other formulas.

[0047] In this specification, internal transmittance refers to the transmittance obtained by subtracting the effect of interface reflection from the measured transmittance, expressed by the formula {measured transmittance / (100-reflectance)}×100.

[0048] In this specification, the transmittance of the substrate, the transmittance of the resin film including cases where the resin contains pigments, and the transmittance spectrum measured by dissolving the pigments in solvents such as dichloromethane, when described as "transmittance," are all referred to as "internal transmittance." On the other hand, the transmittance of the filter having a dielectric multilayer film is the measured transmittance.

[0049] In this specification, for a specific wavelength range, transmittance of 90% or more means that the transmittance is not less than 90% across the entire wavelength range, i.e., the minimum transmittance within that wavelength range is 90% or more. Similarly, for a specific wavelength range, transmittance of 1% or less means that the transmittance is not greater than 1% across the entire wavelength range, i.e., the maximum transmittance within that wavelength range is 1% or less. The same applies to internal transmittance. The average transmittance within a specific wavelength range is the arithmetic mean of the transmittance per 1 nm within that wavelength range, and the average internal transmittance within a specific wavelength range is the arithmetic mean of the internal transmittance per 1 nm within that wavelength range.

[0050] Optical properties can be measured using a UV-Vis spectrophotometer.

[0051] In this specification, the "~" sign indicating a numerical range includes both the upper and lower limits.

[0052] <Filter>

[0053] A filter according to one embodiment of the present invention (hereinafter also referred to as "this filter") is a filter having a substrate and a dielectric multilayer film, wherein the dielectric multilayer film is stacked as the outermost layer on at least one main surface side of the substrate, and the filter satisfies specific optical properties described later.

[0054] Here, the substrate has a resin film comprising a pigment (IR) and a resin, wherein the pigment (IR) has a maximum absorption wavelength in dichloromethane in the range of 680 nm to 1000 nm. By containing a pigment that absorbs near-infrared radiation, the absorption characteristics of the substrate can be utilized to compensate for the reduction in optical properties of the dielectric multilayer film under high incident angle conditions, such as light leakage and noise generation in the near-infrared region. The pigments and resins will be explained later.

[0055] The structure of this filter will be illustrated using the accompanying drawings. Figures 1-4 A cross-sectional view illustrating an example of a filter according to one embodiment.

[0056] Figure 1 The filter 1A shown is an example of having a dielectric multilayer film 30 on one main surface side of the substrate 10. It should be noted that "having a specific layer on the main surface side of the substrate" is not limited to having the layer in contact with the main surface of the substrate, but also includes having other functional layers between the substrate and the layer.

[0057] Figure 2 The filter 1B shown is an example of having a dielectric multilayer film 30 on both main surfaces of the substrate 10.

[0058] Figure 3 The filter 1C shown is an example of a substrate 10 having a support 11 and a resin film 12 laminated on one main surface side of the support 11. The filter 1C further has a dielectric multilayer film 30 on the resin film 12 and a dielectric multilayer film 30 on the unlaminated main surface side of the resin film 12 on the support 11.

[0059] Figure 4 The filter 1D shown is an example of a substrate 10 having a support 11 and resin films 12 laminated on two main surfaces of the support 11. The filter 1D further has a dielectric multilayer film 30 on each resin film 12.

[0060] The filter of the present invention satisfies all of the following optical properties (i-1) to (i-10):

[0061] (i-1) The average reflectivity R in the wavelength range of 450nm to 500nm under the condition of an incident angle of 5 degrees. 450-500(5deg)AVE The average reflectance R is less than 3% and under the condition of an incident angle of 40 degrees. 450-500(40deg)AVE Less than 5%;

[0062] (i-2) The average reflectivity R in the wavelength range of 500nm to 580nm under the condition of an incident angle of 5 degrees. 500-580(5deg)AVE The average reflectance R is less than 2.5% and is obtained under the condition of an incident angle of 40 degrees.500-580(40deg)AVE Less than 4%;

[0063] (i-3) satisfies the above R 450-500(5deg)AVE >R above 500-580(5deg)AVE And the aforementioned R 450-500(40deg)AVE >R above 500-580(40deg)AVE Relationship;

[0064] (i-4) The maximum reflectivity R in the wavelength range of 450nm to 580nm under the condition of an incident angle of 5 degrees. 450-580(5deg)MAX The maximum reflectivity R is less than 4% and is achieved under the condition of an incident angle of 40 degrees. 450-580(40deg)MAX Below 6%;

[0065] (i-5) In the wavelength range of 450 nm to 500 nm, the maximum difference between the transmittance under the condition of 0 degrees incident angle and the transmittance under the condition of 40 degrees incident angle is less than 6%.

[0066] (i-6) In the wavelength range of 500nm to 580nm, the maximum difference between the transmittance under the condition of 0 degrees of incident angle and the transmittance under the condition of 40 degrees of incident angle is less than 5%.

[0067] (i-7) Average transmittance T in the wavelength range of 450 nm to 580 nm under the condition of 0 degrees incident angle. 450-580(0deg)AVE It is over 88%;

[0068] (i-8) In the wavelength range of 600nm to 800nm, the absolute value of the difference between the wavelength with a transmittance of 20% under the condition of an incident angle of 0 degrees and the wavelength with a transmittance of 20% under the condition of an incident angle of 40 degrees is less than 10nm.

[0069] (i-9) In the wavelength range of 600nm to 800nm, the wavelength of 20% under the condition of 0 degrees incident angle is in the range of 640nm to 690nm.

[0070] (i-10) The maximum transmittance T in the wavelength range of 750 nm to 1000 nm under the condition of an incident angle of 0 degrees. 750-1000(0deg)MAX The maximum transmittance T is less than 1% and is obtained under the condition of an incident angle of 40 degrees. 750-1000(40deg)MAX It is less than 1%.

[0071] This filter, which satisfies all optical properties (i-1) to (i-10), is a filter with excellent visible light transmittance and near-infrared light blocking properties, and suppresses ripple generation and changes in near-infrared light blocking properties under conditions of high incident angles such as 40 degrees.

[0072] By satisfying optical properties (i-1), (i-2), and (i-4), the reflectivity in the visible light region is sufficiently low.

[0073] In optical properties (i-1), R 450-500(5deg)AVE Preferably below 2.5%, R 450-500(40deg)AVE Preferably, it is below 4.5%.

[0074] In optical properties (i-2), R 500-580(5deg)AVE Preferably below 2%, R 500-580(40deg)AVE Preferably, it is 3.5% or less.

[0075] In optical properties (i-4), R 450-580(5deg)MAX Preferably below 3.5%, R 450-580(40deg)MAX Preferably, it is below 5.5%.

[0076] By satisfying optical property (i-3), the low reflectivity of the green band, which is particularly important for the visibility of the sensor in the imaging device, is indicated.

[0077] By satisfying optical property (i-7), it is indicated that the transmittance in the visible light region is high. In addition, by satisfying optical properties (i-1), (i-2) and (i-4) to (i-6), it is indicated that ripples are suppressed even under high incident angle conditions.

[0078] In the optical properties (i-5), within the wavelength range of 450 nm to 500 nm, the maximum value of the difference between the transmittance under the condition of an incident angle of 0 degrees and the transmittance under the condition of an incident angle of 40 degrees is preferably 5.5% or less, more preferably 5% or less.

[0079] In the optical properties (i-6), within the wavelength range of 500 nm to 580 nm, the maximum value of the difference between the transmittance under the condition of an incident angle of 0 degrees and the transmittance under the condition of an incident angle of 40 degrees is preferably 4.5% or less, more preferably 4% or less.

[0080] T 450-580(0deg)AVE Preferably, it is 89% or more, and more preferably 90% or more.

[0081] By satisfying the optical property (i-8), it is indicated that in the near-infrared light absorption band of wavelength 600nm to 800nm, even under the condition of high incident angle, the offset (i.e., the change in the blocking property of near-infrared light) is small, and the color reproduction is excellent.

[0082] In the optical properties (i-8), within the wavelength range of 600 nm to 800 nm, the absolute value of the difference between the wavelength with a transmittance of 20% under the condition of an incident angle of 0 degrees and the wavelength with a transmittance of 20% under the condition of an incident angle of 40 degrees is preferably 8 nm or less, and more preferably 6 nm or less.

[0083] By satisfying the optical characteristic (i-9), it is indicated that infrared light is blocked and visible light transmission is effectively obtained. In the optical characteristic (i-9), the wavelength with a transmittance of 20% under the condition of an incident angle of 0 degrees is preferably in the range of 645 nm to 685 nm, and more preferably in the range of 650 nm to 680 nm.

[0084] By satisfying the optical property (i-10), it is indicated that the light-shielding performance is excellent in the near-infrared to long-wavelength range of 750nm to 1000nm, whether under an incident angle of 0 degrees or a high incident angle of 40 degrees. 750-1000(0deg)MAX Preferably, it is 0.95% or less, more preferably 0.9% or less. 750-1000(40deg)MAX Preferably, it is 0.95% or less, more preferably 0.9% or less.

[0085] <Dielectric Multilayer Film>

[0086] In this filter, a dielectric multilayer film is stacked as the outermost layer on at least one main surface side of the substrate.

[0087] In this filter, the dielectric multilayer film preferably satisfies all of the following optical properties (iv-1) to (iv-8):

[0088] (iv-1) Average transmittance T in the wavelength range of 450 nm to 580 nm under the condition of 0 degrees incident angle. 450-580(0deg)AVE The average transmittance T is over 90% and is achieved under the condition of an incident angle of 40 degrees. 450-580(40deg)AVE It is over 90%;

[0089] (iv-2) In the wavelength range of 450 nm to 500 nm, the absolute value of the difference between the average transmittance under the condition of 0 degrees of incident angle and the average transmittance under the condition of 40 degrees of incident angle is less than 3%.

[0090] (iv-3) In the wavelength range of 500 nm to 580 nm, the absolute value of the difference between the average transmittance under the condition of 0 degrees of incident angle and the average transmittance under the condition of 40 degrees of incident angle is less than 2%.

[0091] (iv-4) In the wavelength range of 450 nm 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 less than 6%.

[0092] (iv-5) In the wavelength range of 500 nm to 580 nm, the maximum difference between the transmittance under the condition of 0 degrees of incident angle and the transmittance under the condition of 40 degrees of incident angle is less than 5%.

[0093] (iv-6) In the wavelength range of 600nm to 800nm, the wavelength with a transmittance of 20% under the condition of 0 degrees of incident angle is in the range of 720nm to 770nm.

[0094] (iv-7) Maximum transmittance T in the wavelength range of 780 nm to 850 nm under the condition of 0 degrees incident angle. 780-850(0deg)MAX Greater than or equal to 4% and less than 10%;

[0095] (iv-8) Maximum transmittance T in the wavelength range of 900 nm to 980 nm under the condition of an incident angle of 40 degrees. 900-980(40deg)MAX Greater than or equal to 1% and less than 5%.

[0096] By satisfying the optical property (iv-1), it is shown that the transmittance in the visible light region is excellent, whether the incident angle is 0 degrees or at a high incident angle of 40 degrees.

[0097] T 450-580(0deg)AVE Preferably, it is 91% or more, and more preferably 92% or more.

[0098] T 450-580(40deg)AVE Preferably, it is 90.5% or more, and more preferably 91% or more.

[0099] By satisfying the optical properties (iv-2) to (iv-5), it is shown that ripple generation in the visible light region is suppressed even under a high incident angle of 40 degrees.

[0100] In the optical properties (iv-2), within the wavelength range of 450 nm to 500 nm, the absolute value of the difference between the average transmittance under the condition of an incident angle of 0 degrees and the average transmittance under the condition of an incident angle of 40 degrees is preferably 2.5% or less, more preferably 2% or less.

[0101] In the optical properties (iv-3), within the wavelength range of 500 nm to 580 nm, the absolute value of the difference between the average transmittance under the condition of an incident angle of 0 degrees and the average transmittance under the condition of an incident angle of 40 degrees is preferably 1.6% or less, more preferably 1.2% or less.

[0102] In the optical properties (iv-4), the maximum value of the difference between the transmittance at an incident angle of 0 degrees and the transmittance at an incident angle of 40 degrees in the wavelength range of 450 nm to 500 nm is preferably 5.5% or less, more preferably 5% or less.

[0103] In the optical properties (iv-5), the maximum value of the difference between the transmittance at an incident angle of 0 degrees and the transmittance at an incident angle of 40 degrees in the wavelength range of 500 nm to 580 nm is preferably 4.5% or less, more preferably 4% or less.

[0104] By satisfying the optical properties (iv-6), it is indicated that the transmittance in the red band is excellent, and the light-shielding properties in the near-infrared region at wavelengths of 770 nm and beyond are excellent. In the optical properties (iv-6), the wavelength at which the transmittance is 20% under the condition of an incident angle of 0 degrees is preferably in the range of 725 nm to 765 nm, and more preferably in the range of 730 nm to 760 nm.

[0105] Optical properties (iv-7) to (iv-8) specify the permissible range of light leakage in the near-infrared region.

[0106] T 780-850(0deg)MAX Preferably 4% to 9%, more preferably 4% to 8%.

[0107] T 900-980(40deg)MAX Preferably, it is 1% to 4.5%, more preferably 1% to 4%.

[0108] As shown in the optical properties (iv-2) to (iv-5), the dielectric multilayer film of this invention suppresses the generation of ripples in the visible light region even under a high incident angle of 40 degrees.

[0109] On the other hand, as shown in the optical properties (iv-7) to (iv-8) above, light leakage can occur in the near-infrared wavelength range of 780 nm and beyond under incident angles of 0 degrees and 40 degrees. Since this wavelength range is compensated for by the absorption of NIR pigments in the resin film described later, the filter as a whole can block light even if light leakage occurs.

[0110] The filter of the present invention is a filter that combines the above-mentioned dielectric multilayer film and the resin film described later. The filter has high visible light transmittance as shown in optical property (i-7) and high near-infrared light blocking as shown in optical property (i-10). As shown in optical properties (i-1) to (i-2) and (i-4) to (i-6), ripples are suppressed even under high incident angle conditions. As shown in optical property (i-8), changes in near-infrared light blocking under high incident angle conditions are suppressed.

[0111] In this filter, it is preferable to design at least one of the dielectric multilayer films as a near-infrared reflective layer (hereinafter also referred to as an NIR reflective layer). When the dielectric multilayer films are provided on both main surfaces of the substrate, it is preferable to design the other dielectric multilayer film as an NIR reflective layer, a reflective layer having a reflective region other than the near-infrared region, or an anti-reflective layer.

[0112] A NIR reflective layer is a dielectric multilayer film designed to block light in the near-infrared region. For example, an NIR reflective layer may have wavelength selectivity, transmitting visible light and primarily reflecting light in the near-infrared region, excluding the light-shielding region of the resin film which acts as an absorption layer. It should be noted that the reflective region of the NIR reflective layer may include the light-shielding region of the resin film in the near-infrared region. The NIR reflective layer may also be appropriately designed to further block light in wavelength ranges other than the near-infrared region, such as near-ultraviolet light, beyond its NIR reflective properties.

[0113] The NIR reflective layer is, for example, composed of a dielectric multilayer film obtained by alternately stacking a low-refractive-index dielectric film (low-refractive-index film) and a high-refractive-index dielectric film (high-refractive-index film). The high-refractive-index film preferably has a refractive index of 1.6 or higher, 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 considering factors such as film formation properties, reproducibility of refractive index, and stability.

[0114] On the other hand, a low refractive index film preferably has a refractive index less than 1.6, and more preferably a refractive index greater than or equal to 1.45 and less than 1.55. Examples of materials that can be used for low refractive index films include SiO2 and SiO2. x N y Considering factors such as reproducibility, stability, and economy of film formation, SiO2 is preferred.

[0115] In order to produce multilayer films that can suppress ripples even under high incident angles but can produce light leakage in the near-infrared wavelength range of 780 nm and beyond, for example, reducing the number of layers in the multilayer film can be considered.

[0116] From the viewpoint of light-shielding properties in the near-infrared wavelength range, the total number of dielectric multilayer films constituting the NIR reflective layer is preferably 20 or more, more preferably 25 or more, and even more preferably 30 or more. However, as the total number of layers increases, ripples, warping, or an increase in film thickness may occur. Therefore, the total number of layers is preferably 100 or less, more preferably 75 or less, and even more preferably 60 or less.

[0117] In addition, from the viewpoint of reducing filter warping, the overall thickness of the reflective layer is preferably 2μm to 10μm.

[0118] In addition, vacuum film formation processes such as CVD, sputtering, and vacuum evaporation can be used in the formation of dielectric multilayer films; wet film formation processes such as spraying and immersion can also be used.

[0119] The specified optical properties can be provided by a single NIR reflective layer (a set of dielectric multilayer films) or by two NIR reflective layers. When there are two or more NIR reflective layers, each reflective layer can have the same or different configurations. Typically, multiple reflective layers with different reflection bands are used. When two reflective layers are provided, one layer can be configured as a near-infrared reflective layer that blocks short-wavelength light in the near-infrared region, and the other layer can be configured as a near-infrared and near-ultraviolet reflective layer that blocks both long-wavelength and near-ultraviolet light in the same near-infrared region.

[0120] Examples of antireflective layers include multilayer dielectric films, intermediate refractive index media, and moth-eye structures with gradually changing refractive indices. Among these, multilayer dielectric films are preferred from the perspective of optical efficiency and productivity. Similar to reflective layers, antireflective layers are obtained by alternately stacking thin films of dielectrics with different refractive indices.

[0121] <Substrate>

[0122] In the filter of the present invention, the substrate has a resin film comprising NIR pigment (IR) and resin, as described later.

[0123] <Optical Properties of Resin Films>

[0124] The resin film preferably satisfies all of the following optical properties (ii-1) to (ii-6):

[0125] (ii-1) Average internal transmittance T in the wavelength range of 450 nm to 580 nm 450-580AVE It is over 88%;

[0126] (ii-2) In the wavelength range of 600nm to 700nm, the wavelength with an internal transmittance of 20% is in the range of 640nm to 690nm;

[0127] (ii-3) Internal transmittance T at a wavelength of 700 nm 700 Less than 1%;

[0128] (ii-4) Internal transmittance T at a wavelength of 750 nm 750 Less than 10%;

[0129] (ii-5) Internal transmittance T at a wavelength of 800 nm 800 Less than 20%;

[0130] (ii-6) Internal transmittance T at a wavelength of 950 nm 950 It is between 60% and 95%.

[0131] By satisfying the optical property (ii-1), it is indicated that the transmittance in the visible light region is high.

[0132] T 450-580AVE Preferably, it is 89% or more, and more preferably 90% or more.

[0133] By satisfying optical property (ii-2), it is shown that the transmittance in the red band is excellent and that it can compensate for the oblique incidence shift of the dielectric multilayer film with excellent light-shielding properties in the near-infrared region at wavelengths of 700 nm and beyond.

[0134] In optical properties (ii-2), the wavelength at which the internal transmittance is 20% is preferably in the range of 645 nm to 685 nm, and more preferably in the range of 650 nm to 680 nm.

[0135] By satisfying optical properties (ii-3) to (ii-5), it is indicated that light in the wavelength range that is prone to leakage in the dielectric multilayer film can be blocked by absorption.

[0136] T 700 Preferably, it is below 0.9%.

[0137] T 750 Preferably, it is 9.5% or less, more preferably 9% or less.

[0138] T 800 Preferably, it is 18% or less, more preferably 16% or less.

[0139] Optical properties (ii-6) specify the range of permissible transmittance over the long wavelength range.

[0140] T 950 Preferably, it is 60% or more and 92.5% or less, more preferably 60% or more and 90% or less.

[0141] <NIR Pigment>

[0142] NIR pigments (IR) are NIR pigments that have maximum absorption wavelengths in dichloromethane in the range of 680 nm to 1000 nm. By containing this pigment, near-infrared light can be effectively blocked.

[0143] In the spectral internal transmittance curve measured by dissolving the pigment (IR) in the resin in such a way that the internal transmittance in the resin constituting the resin film is 10% at the maximum absorption wavelength, the pigment (IR) preferably satisfies the following characteristic (iii-1):

[0144] (iii-1) When the maximum absorption wavelength in the above resin is set as D [nm] and the average internal transmittance in the range of 450nm to 580nm is set as E, E > 100 - (D / 100).

[0145] Pigments (IR) have a maximum absorption wavelength in the near-infrared region, but the larger the maximum absorption wavelength, the easier it is to absorb visible light, thus tending to have reduced transmittance in the visible light region. Characteristic (iii-1) specifies the relationship between the maximum absorption wavelength and the lower limit of visible light transmittance. Therefore, if a pigment (IR) satisfies characteristic (iii-1), it indicates that its visible light transmittance is sufficiently high.

[0146] Characteristic (iii-1) is more preferably E > 101.5 - (D / 100).

[0147] NIR pigments (IR) can be composed of one compound or contain two or more compounds. From the viewpoint of easily satisfying the optical properties (ii-3) to (ii-6) of the above-mentioned resin film, such as absorbing light in a wide wavelength range of 700 nm to 1000 nm, it is preferable to include three or more compounds in dichloromethane that have the maximum absorption wavelength in the range of 680 nm to 1000 nm, and particularly more preferably compounds (A) containing one or more of the following properties, compounds (B) containing one or more of the following properties, and compounds (C) containing one or more of the following properties.

[0148] Compound (A): The compound that has the maximum absorption wavelength in dichloromethane in the range of wavelengths greater than or equal to 690 nm and less than 735 nm;

[0149] Compound (B): The compound that has the maximum absorption wavelength in dichloromethane in the range of wavelengths greater than or equal to 735 nm and less than 835 nm;

[0150] Compound (C): The compound that has the maximum absorption wavelength in dichloromethane in the range of wavelengths above 900 nm and below 1000 nm.

[0151] Furthermore, 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, and more preferably 50 nm or more. This allows for effective light blocking by absorbing light in the wavelength range where leakage is easily generated by the dielectric multilayer film.

[0152] Considering the transmittance in the visible light region, solubility in the resin, and durability, compound (A) is preferably selected from succinic acid. At least one of the group consisting of salt compounds and anthocyanin compounds, wherein compound (B) is selected from squalene. At least one of the group consisting of salt compounds and anthocyanin compounds, wherein compound (C) is selected from squalene. At least one of the group consisting of salt compounds, anthocyanin compounds and ammonium compounds.

[0153] <Square acid inner> Salt compounds >

[0154] Squamous acid The salt compound is preferably a compound represented by formula (I), a compound represented by formula (II) as described later, or a compound represented by formula (V) as described later.

[0155] It should be noted that within the squaric acid... When a salt compound contains two or more identical symbols, these symbols can be the same or different. The same applies to anthocyanin compounds.

[0156] <Square acid inner> Salt compound (I) >

[0157]

[0158] The symbols in the above formula are as follows.

[0159] R 24 and R 26 Each of the following can be independently represented: hydrogen atom, halogen atom, hydroxyl group, alkyl or alkoxy group with 1 to 20 carbon atoms, acyl group with 1 to 10 carbon atoms, aryl group with 6 to 11 carbon atoms, aralkyl group with 7 to 18 carbon atoms that may have substituents and may have oxygen atoms between carbon atoms, -NR 27 R 28 (R 27 and R 28 Each independently represents a hydrogen atom, an alkyl group with 1 to 20 carbon atoms, or a -C(=O)-R group. 29 (R 29 (Hydrogen atom, halogen atom, hydroxyl group, may have substituents and may contain unsaturated bonds between carbon atoms, oxygen atom, saturated or unsaturated ring structure, hydrocarbon group with 1 to 25 carbon atoms), -NHR 30 or -SO2-R 30 (R 30 Each of the carbon atoms may consist of one or more hydrogen atoms that can be substituted with halogen atoms, hydroxyl groups, carboxyl groups, sulfonyl groups, or cyano groups, and may contain unsaturated bonds, oxygen atoms, saturated or unsaturated ring structures, or hydrocarbon groups with 1 to 25 carbon atoms, or groups represented by the following formula (S) (R). 41 R 42 Independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. k is 2 or 3.

[0160]

[0161] R 21 and R22 R 22 and R 25 and R 21 and R 23 They can connect with each other and together with nitrogen atoms to form 5-membered or 6-membered heterocycles A, B, and C, respectively.

[0162] As R in the case of forming heterocyclic A 21 and R 22 The bonded divalent group -Q- represents an alkylene or alkyleneoxy group, wherein the hydrogen atom of the alkylene or alkyleneoxy group may be replaced by 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 and a substituent.

[0163] As R in the case of forming heterocyclic B 22 and R 25 The bonded divalent group -X 1 -Y 1 - and R in the case of forming heterocyclic C 21 and R 23 The bonded divalent group -X 2 -Y 2 -(The side bonded to nitrogen is X) 1 and X 2 ), X 1 and X 2 Each is a group represented by the following formula (1x) or (2x), Y 1 and Y 2 Each is a group selected from any of the following formulas (1y) to (5y). In X 1 and X 2 When each of the groups is represented by the following formula (2x), Y 1 and Y 2 Each can be a single bond, and in this case, there can be oxygen atoms between carbon atoms.

[0164]

[0165] In formula (1x), each of the four Zs independently represents a hydrogen atom, a hydroxyl group, an alkyl group with 1 to 6 carbon atoms or an alkoxy group with 1 to 6 carbon atoms, or -NR. 38 R 39 (R 38 and R 39 Each can independently represent an alkyl group having 1 to 20 hydrogen 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 37It represents an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms.

[0166] R 27 R 28 R 29 R 31 ~R 37 R without the formation of heterocycles 21 ~R 23 and R 25 Each can bond with any of these groups to form a 5-membered or 6-membered ring. R 31 and R 36 R 31 and R 37 They can be bonded directly.

[0167] R without heterocyclic formation 21 R 22 R 23 and R 25 Each of the following can be independently represented as a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group having 1 to 20 carbon atoms 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 aralkyl group having 7 to 18 carbon atoms that may have substituents and may have oxygen atoms between carbon atoms.

[0168] As for compound (I), for example, compounds represented by any of formulas (I-1) to (I-3) can be listed. From the viewpoints of solubility in resin, heat resistance and light resistance in resin, and visible light transmittance of the resin layer containing the compound, compounds represented by formula (I-1) are particularly preferred.

[0169]

[0170] The symbols in equations (I-1) to (I-3) are defined in the same way as the same symbols in equation (I), and the preferred methods are also the same.

[0171] In compound (I-1), as X 1 Preferred group (2x); as Y 1 Preferably, a single bond or a group (1y). In this case, as R 31 ~R 36 Preferably, it is an alkyl group having 1 to 3 hydrogen atoms, more preferably a hydrogen atom or a methyl group. It should be noted that, as -Y 1 -X 1 Specifically, divalent organic groups represented by formulas (11-1) to (12-3) can be listed.

[0172] -C(CH3)2-CH(CH3)- ……(11-1)

[0173] -C(CH3)2-CH2- ………(11-2)

[0174] -C(CH3)2-CH(C2H5)- ……(11-3)

[0175] -C(CH3)2-C(CH3)(nC3H7)- ……(11-4)

[0176] -C(CH3)2-CH2-CH2-……(12-1)

[0177] -C(CH3)2-CH2-CH(CH3)- ……(12-2)

[0178] -C(CH3)2-CH(CH3)-CH2-……(12-3)

[0179] Furthermore, in compound (I-1), considering the steepness of the change near the boundary between the visible and near-infrared regions in the spectral transmittance curve, R... 21 More preferably, it is a group represented by formula (4-1) or formula (4-2).

[0180]

[0181] In equations (4-1) and (4-2), R 71 ~R 75 Independently represents an alkyl group having 1 to 4 hydrogen atoms, halogen atoms, or carbon atoms.

[0182] In compound (I-1), R 24 Preferred is -NR 27 R 28 As -NR 27 R 28 From the viewpoint of solubility in resins and coating solvents, -NH-C(=O)-R is preferred. 29 or -NH-SO2-R 30 .

[0183] In compound (I-1) R 24 -NH-C(=O)-R 29 The compound is shown in formula (I-11).

[0184]

[0185] R 23 and R 26The atom is preferably a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and more preferably all of them are hydrogen atoms.

[0186] As R 29 Preferably, the substituent is an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms and having an oxygen atom between the carbon atoms. Examples of substituents include: hydroxyl, carboxyl, sulfonyl, cyano, alkyl group having 1 to 6 carbon atoms, fluoroalkyl group having 1 to 6 carbon atoms, alkoxy group having 1 to 6 carbon atoms, and acyloxy group having 1 to 6 carbon atoms.

[0187] As R 29 Preferably, the group is selected from alkyl groups with 1 to 17 carbon atoms that are straight-chain, branched, or cyclic, phenyl groups that can be substituted by alkoxy groups with 1 to 6 carbon atoms, and aralkyl groups with 7 to 18 carbon atoms that can have oxygen atoms between carbon atoms.

[0188] As R 29 Alternatively, the following groups may be used independently: the group is a hydrocarbon group with 5 to 25 carbon atoms, having at least one branched chain, and having one or more hydrogen atoms that can be replaced by hydroxyl, carboxyl, sulfonyl or cyano groups and may contain unsaturated bonds, oxygen atoms, saturated or unsaturated ring structures between carbon atoms.

[0189] As compound (I-11), more specifically, the compounds shown in the table below can be listed. Additionally, the compounds shown in the table below are in squaric acid. The symbols on the left and right sides of the salt skeleton have the same meaning.

[0190] [Table 1]

[0191]

[0192] Among these compounds (I-11), compounds (I-11-11) to (I-11-15), (I-11-26) to (I-11-30) are preferred in terms of transmittance in the visible light region and solubility in resin.

[0193] In compound (I-1) R 24 -NH-SO2-R 30 The compound is shown in formula (I-12).

[0194]

[0195] R 23 and R 26The atom is preferably a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and more preferably all of them are hydrogen atoms.

[0196] From the perspective of lightfastness, R 30 Independently preferred are alkyl groups having 1 to 12 branched carbon atoms, alkoxy groups having 1 to 12 branched carbon atoms, or hydrocarbon groups having 6 to 16 carbon atoms with an unsaturated ring structure. Examples of unsaturated ring structures include: benzene, toluene, xylene, furan, benzofuran, etc. 30 More preferably, it is an alkyl group having 1 to 12 branched carbon atoms or an alkoxy group having 1 to 12 branched carbon atoms. It should be noted that, in the representation of R... 30 In each of the groups, some or all of the hydrogen atoms can be replaced by halogen atoms, especially fluorine atoms.

[0197] As compound (I-12), more specifically, the compounds shown in the table below can be listed. Additionally, the compounds shown in the table below are in squaric acid. The symbols on the left and right sides of the salt skeleton have the same meaning.

[0198] [Table 2]

[0199]

[0200] Among these compounds (I-12), compounds (I-12-11) to (I-12-15), (I-12-26) to (I-12-30) are preferred in terms of transmittance in the visible light region and solubility in the resin.

[0201] <Square acid inner> Salt compound (II) >

[0202]

[0203] The symbols in the above formula are as follows.

[0204] Each ring Z is independently a 5-membered or 6-membered ring with 0 to 3 heteroatoms, and the hydrogen atoms in ring Z can be substituted.

[0205] R 1 and R 2 R 2 and R 3 and R 1The carbon atoms or heteroatoms constituting ring Z can connect with each other and, together with nitrogen atoms, form heterocycles A1, B1, and C1, respectively. In this case, the hydrogen atoms in heterocycles A1, B1, and C1 can be substituted. R without the formation of heterocycles... 1 and R 2 Each can independently represent a hydrogen atom, a halogen atom, or a hydrocarbon group, which may contain unsaturated bonds, heteroatoms, saturated or unsaturated ring structures between carbon atoms, and may have substituents. R 4 And R in the case of no heterocycle formation 3 Each of these can independently represent a hydrogen atom, a halogen atom, or an alkyl or alkoxy group, wherein each alkyl or alkoxy group may contain heteroatoms between carbon atoms and may have substituents.

[0206] As for compound (II), for example, compounds represented by any of formulas (II-1) to (II-3) can be listed. From the viewpoint of solubility in resin and visible light transmittance in resin, compounds represented by formula (II-3) are particularly preferred.

[0207]

[0208] In equations (II-1) and (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 that may have substituents; R 3 ~R 6 Each can independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 10 carbon atoms that may have substituents.

[0209] In equation (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 that may have substituents; R 7 and R 8 Each can independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 5 carbon atoms that may have substituents.

[0210] Considering factors such as solubility in resins and visible light transmittance, R in compounds (II-1) and (II-2) 1 and R 2 Alkyl groups having 1 to 15 carbon atoms are preferred, alkyl groups having 7 to 15 carbon atoms are more preferred, and R is even more preferred. 1 and R 2 At least one of them is a branched alkyl group having 7 to 15 carbon atoms, with R being particularly preferred.1 and R 2 Both are branched alkyl groups with 8 to 15 carbon atoms.

[0211] Considering factors such as solubility in transparent resins and visible light transmittance, R in compound (II-3) 1 Alkyl groups having 1 to 15 carbon atoms are preferred, more preferably alkyl groups having 1 to 10 carbon atoms, and particularly preferably ethyl or isopropyl.

[0212] From the perspectives of visible light transmittance and ease of synthesis, R 4 The preferred atoms are hydrogen atoms or halogen atoms, with hydrogen atoms being particularly preferred.

[0213] R 7 and R 8 The preferred components are hydrogen atoms, halogen atoms, and alkyl groups having 1 to 5 carbon atoms that can be replaced by halogen atoms; more preferably, hydrogen atoms, halogen atoms, and methyl groups.

[0214] R 9 ~R 12 The preferred components are hydrogen atoms, halogen atoms, and alkyl groups having 1 to 5 carbon atoms that can be replaced by halogen atoms.

[0215] As -CR 9 R 10 -CR 11 R 12 - Examples of divalent organic groups represented by the following groups (13-1) to (13-5) can be listed.

[0216] -CH(CH3)-C(CH3)2- ……(13-1)

[0217] -C(CH3)2-CH(CH3)- ……(13-2)

[0218] -C(CH3)2-CH2- ……(13-3)

[0219] -C(CH3)2-CH(C2H5)- ……(13-4)

[0220] -CH(CH3)-C(CH3)(CH2-CH(CH3)2)- ……(13-5)

[0221] As compounds (II-3), more specifically, the compounds shown in the table below can be listed. Additionally, the compounds shown in the table below are in squaric acid. The symbols on the left and right sides of the salt skeleton have the same meaning.

[0222] [Table 3]

[0223]

[0224] Compounds (I) through (II) can each be manufactured by known methods. Compound (I) can be manufactured by the methods described in U.S. Patent No. 5,543,086, U.S. Patent Application Publication No. 2014 / 0061505, and International Publication No. 2014 / 088063. Compound (II) can be manufactured by the method described in International Publication No. 2017 / 135359.

[0225] <Anthocyanin compounds>

[0226] The anthocyanin compound is preferably a compound represented by formula (III) or formula (IV).

[0227] <Anthocyanin compounds (III), (IV)>

[0228]

[0229] The symbols in the above formula are as follows.

[0230] R 101 ~R 109 and R 121 ~R 131 Each can independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 15 carbon atoms that may have substituents, or an aryl group having 5 to 20 carbon atoms that may have substituents. R 110 ~R 114 and R 132 ~R 136 Each can be independently represented by a hydrogen atom, a halogen atom, or an alkyl group having 1 to 15 carbon atoms.

[0231] X - It represents a monovalent anion.

[0232] n1 and n2 are either 0 or 1. (This is related to the inclusion of -(CH2)) n1 -Carbon ring and containing -(CH2) n2 The hydrogen atom bonded to the carbon ring can be replaced by a halogen atom, an alkyl group having 1 to 15 carbon atoms that can have a substituent, or an aryl group having 5 to 20 carbon atoms that can have a substituent.

[0233] In the above, alkyl groups (including those with alkoxy groups) can be straight-chain, branched, or saturated ring structures. Aryl groups are groups bonded via carbon atoms of aromatic rings such as benzene, naphthyl, biphenyl, furan, thiophene, and pyrrole rings that constitute aromatic compounds. Examples of substituents that can be alkyl groups with 1 to 15 carbon atoms, alkoxy groups with 1 to 15 carbon atoms, or aryl groups with 5 to 20 carbon atoms include halogen atoms and alkoxy groups with 1 to 10 carbon atoms.

[0234] In equations (III) and (IV), R 101 and R 121 Preferably, it is an alkyl group having 1 to 15 carbon atoms or an aryl group having 5 to 20 carbon atoms. From the viewpoint of maintaining high visible light transmittance in the resin, it is more preferably an alkyl group having 1 to 15 carbon atoms with a branched chain.

[0235] In equations (III) and (IV), R 102 ~R 105 R 108 R 109 R 122 ~R 127 R 130 and R 131 Preferably, each of the atoms is a hydrogen atom, an alkyl group having 1 to 15 carbon atoms, an alkoxy group having 1 to 15 carbon atoms, or an aryl group having 5 to 20 carbon atoms. From the viewpoint of obtaining high visible light transmittance, it is more preferably a hydrogen atom.

[0236] In equations (III) and (IV), R 110 ~R 114 and R 132 ~R 136 Preferably, each is an alkyl group having 1 to 15 carbon atoms, and from the viewpoint of obtaining high visible light transmittance, it is more preferably a hydrogen atom.

[0237] R 106 R 107 R 128 and R 129 Preferably, each is independently 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 chain, cyclic, or branched alkyl groups), more preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms. Additionally, R 106 and R 107 R 128 and R 129 Preferably, they are the same group.

[0238] As X - I can be listed - BF4- PF6 - ClO4 - Anions represented by formulas (X1) and (X2), preferably BF4. - or PF6 - .

[0239]

[0240] In the following description, compound (III) will be used except for R. 101 ~R 114 The part other than this is also called the skeleton (III). The same applies to compound (IV).

[0241] Compounds in formula (III) with n1 = 1 are shown in formula (III-1), and compounds in formula (III) with n1 = 0 are shown in formula (III-2).

[0242]

[0243] In equations (III-1) and (III-2), R 101 ~R 114 and X - The situation is the same as in equation (III). R 115 ~R 120 Each can independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 15 carbon atoms that may have substituents, an alkoxy group having 1 to 15 carbon atoms that may have substituents, or an aryl group having 5 to 20 carbon atoms that may have substituents. R 115 ~R 120 Preferably, each is independently 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 chain, cyclic, or branched alkyl groups), more preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms. Additionally, R 115 ~R 120 Preferably, they are the same group.

[0244] Compounds in formula (IV) with n2 = 1 are shown in formula (IV-1), and compounds in formula (IV) with n2 = 0 are shown in formula (IV-2).

[0245]

[0246] In equations (IV-1) and (IV-2), R 121 ~R 136 and X - The same applies as in equation (IV). R 137 ~R 142Each can independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 15 carbon atoms that may have substituents, an alkoxy group having 1 to 15 carbon atoms that may have substituents, or an aryl group having 5 to 20 carbon atoms that may have substituents. R 137 ~R 142 Preferably, each is independently 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 chain, cyclic, or branched alkyl groups), more preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms. Additionally, R 137 ~R 142 Preferably, they are the same group.

[0247] As compounds represented by formula (III-1), compounds represented by formula (III-2), compounds represented by formula (IV-1), and compounds represented by formula (IV-2), more specifically, compounds in which the atoms or groups bonded to each skeleton are those shown in the table below can be listed. In all the compounds shown in the table below, R... 101 ~R 109 The left and right sides of the formula are identical. 121 ~R 131 The left and right sides of the formula are the same.

[0248] R in the table below 110 -R 114 And R in the table below 132 -R 136 The atom or group bonded to the central benzene ring in each formula is represented by "H" when all five atoms are hydrogen atoms. In R... 110 -R 114 If any one of the elements is a substituent and the others are hydrogen atoms, only the symbol for the substituent and the combination of the substituents are recorded. For example, "R 112 The description of "-C(CH3)3" indicates R 112 It is -C(CH3)3 and otherwise consists of hydrogen atoms. For R 132 -R 136 Same here.

[0249] R in Table 4 115 -R 120 and R in Table 6 137 -R 142 The atom or group bonded to the central cyclohexane ring in formulas (III-1) and (IV-1) is represented by "H" if all six atoms are hydrogen atoms. In R 115 -R 120 If any one of the elements is a substituent and the others are hydrogen atoms, only the symbol of the substituent and the combination of the substituents are recorded. For R137 -R 142 Same here.

[0250] R in Table 5 115 -R 118 and R in Table 7 137 -R 140 The atom or group bonded to the central cyclopentane ring in formulas (III-2) and (IV-2) is represented by "H" if all four atoms are hydrogen atoms. In R 115 -R 118 If any one of the elements is a substituent and the others are hydrogen atoms, only the symbol of the substituent and the combination of the substituents are recorded. For R 137 -R 140 Same here.

[0251] X is not shown in the table below. - However, among all compounds, X - BF4 - or PF6 - .

[0252] [Table 4]

[0253]

[0254] Among these compounds (III-1), compounds (III-1-1) to (III-1-5) are preferred in terms of transmittance in the visible light region and solubility in resin.

[0255] [Table 5]

[0256]

[0257] Among these compounds (III-2), compounds (III-2-1) to (III-2-5) are preferred in terms of transmittance in the visible light region and solubility in resin.

[0258] [Table 6]

[0259]

[0260] Among these compounds (IV-1), compounds (IV-1-1) to (IV-1-5) are preferred in terms of transmittance in the visible light region and solubility in resin.

[0261] [Table 7]

[0262]

[0263] Among these compounds (IV-2), compounds (IV-2-1) to (IV-2-5) are preferred in terms of transmittance in the visible light region and solubility in resin.

[0264] For compounds (III) and (IV), as mentioned above, the skeletons differ, resulting in different wavelength ranges for the absorption maxima. For compound (III), although the maximum absorption wavelength also depends on the type and combination of atoms or groups bonded to the skeleton, the maximum absorption wavelength is in the range of approximately 760 nm to approximately 830 nm. For compound (IV), although the maximum absorption wavelength also depends on the type and combination of atoms or groups bonded to the skeleton, the maximum absorption wavelength is in the range of approximately 800 nm to approximately 900 nm.

[0265] Furthermore, for compound (III), the maximum absorption wavelength differs when n1 in the skeleton is 1 and when n1 is 0. Although the maximum absorption wavelength also depends on the type and combination of atoms or groups bonded to the skeleton, when n1 is 1, the maximum absorption wavelength is in the range of about 760 nm to about 800 nm, while when n1 is 0, the maximum absorption wavelength is in the range of about 800 nm to about 830 nm.

[0266] Similarly, for compound (IV), the maximum absorption wavelength differs when n2 is 1 and when n2 is 0. Although the maximum absorption wavelength also depends on the type and combination of atoms or groups bonded to the backbone (IV-1), the maximum absorption wavelength is in the range of about 800 nm to about 830 nm when n2 is 1, and in the range of about 830 nm to about 900 nm when n2 is 0.

[0267] Compounds (III) and (IV) can be manufactured, for example, by the methods described in Dyes and pigments, 73 (2007), pp. 344-352, and J. Heterocyclic chem, 42, 959 (2005).

[0268] <Square acid inner> Salt compound (V) >

[0269]

[0270] In equation (V), R 51 ~R 54 Each is independently a hydrogen atom, halogen atom, hydroxyl group, alkyl group, aryl group, or aralkyl group.

[0271] Alkyl, aryl, or aralkyl groups may each have substituents.

[0272] In addition, alkyl, aryl, or aralkyl groups may each contain unsaturated bonds, oxygen atoms, ester bonds, amide bonds, or thioamide bonds between carbon-carbon atoms.

[0273] In addition, alkyl, aryl, or aralkyl groups may each have an oxygen atom, ester bond, amide bond, or thioamide bond at the end of the thiophene ring.

[0274] R 51 and R 52 R 52 and R 53 and R 53 and R 54 They can be connected to each other to form a single ring or a polycyclic ring composed of 2 to 4 rings. In this case, the hydrogen atoms bonded to the ring can be replaced by substituents.

[0275] Examples of halogen atoms include fluorine, chlorine, bromine, and iodine, with fluorine and chlorine atoms being preferred.

[0276] In R 51 ~R 54 When the carbon atom is alkyl, the number of carbon atoms is preferably 1 to 20, more preferably 1 to 15, and even more preferably 1 to 12.

[0277] In R 51 ~R 54 When the carbon group is aryl, the number of carbon atoms is preferably 4 to 20, more preferably 4 to 17, and even more preferably 4 to 14.

[0278] In R 51 ~R 54 When the alkyl group is aralkyl, the number of carbon atoms is preferably 5 to 20, more preferably 5 to 18, and even more preferably 5 to 15.

[0279] In R 51 ~R 54 In the case of substituents, the number of carbon atoms in the above-mentioned number of carbon atoms includes the number of carbon atoms of the substituents.

[0280] As R 51 ~R 54 Substituents in R can be listed as follows: halogen atom, hydroxyl group, carboxyl group, sulfonyl group, cyano group, amino group, N-substituted amino group, nitro group, alkoxy carbonyl group, carbamoyl group, N-substituted carbamoyl group, imide group, and alkoxy group with 1 to 10 carbon atoms. 51 ~R 54 In the case of aryl or aralkyl, the substituent is a hydrogen atom or R bonded to the aromatic ring that is replaced. 51 ~R 54The group containing alkyl hydrogen atoms, in addition to the substituents mentioned above, also includes aryl groups.

[0281] R 51 and R 52 R 52 and R 53 and R 53 and R 54 They can be connected to each other to form a single ring or a polycyclic ring composed of 2 to 4 rings. In this case, the hydrogen atoms bonded to the ring can be replaced by substituents.

[0282] In R 52 and R 53 In the case of connection, squaric acid The salt compound (V) comprises a structure formed by the fusion of at least three rings through the formation of a ring between two thiophene rings. In R... 52 and R 53 Hydrogen atoms bonded on the ring formed by the connection can be replaced by substituents.

[0283] As a replacement for R 52 and R 53 Substituents in a linked ring-bonded hydrogen atom can be listed as those related to R. 51 ~R 54 The same substituents as those in the group and phenyl groups that can have substituents. Examples of substituents that can be found in phenyl groups include those related to R. 51 ~R 54 The substituents are the same groups as those in the original text.

[0284] R 55 and R 56 Each is independently an alkyl or aralkyl group, which may each have substituents and may contain unsaturated bonds, oxygen atoms, or nitrogen atoms between carbon atoms. Alternatively, R 55 and R 56 They can connect with each other and form 5- to 10-membered heterocycles together with nitrogen atoms. In this case, the hydrogen atoms bonded to the ring can be replaced by substituents.

[0285] As R 55 and R 56 Substituents in R can be listed as those with R 51 ~R 54 The same substituents in R. 55 and R 56 In the case of aryl alkyl groups, R 55 and R 56 The alkyl groups can be further replaced by aryl groups.

[0286] In R 55 and R 56When the carbon atom is alkyl, the number of carbon atoms is preferably 1 to 20, more preferably 1 to 12, and even more preferably 1 to 10. From the viewpoint of visible light transmittance and solubility in resins and solvents, R... 55 and R 56 Preferably, the alkyl group is a straight-chain, branched, or cyclic alkyl group with 3 to 20 carbon atoms, in which oxygen atoms may be present between carbon atoms. In the case of a straight-chain alkyl group, the number of carbon atoms is more preferably 3 to 12; in the case of a branched alkyl group, the number of carbon atoms is more preferably 3 to 10; and in the case of a cyclic alkyl group, the number of carbon atoms is more preferably 5 to 10. In R 15 and R 16 In the case of substituents, the number of carbon atoms in the above-mentioned number of carbon atoms includes the number of carbon atoms of the substituents.

[0287] R 55 and R 56 For example, it is further preferred to select a group from (1a) to (15a), and particularly preferred to select a group (1a).

[0288]

[0289] R 55 and R 56 They can connect with each other and form 5- to 10-membered heterocycles together with nitrogen atoms. The heterocycle may contain oxygen atoms as ring-forming elements in addition to nitrogen atoms. The heterocycle is preferably a 5- or 6-membered ring, and particularly preferably a 5-membered ring. When the hydrogen atoms bonded to the heterocycle are substituted, examples of substituents that replace the hydrogen atoms include halogen atoms, hydroxyl groups, alkyl groups with 1 to 10 carbon atoms or alkoxy groups with 1 to 10 carbon atoms, aryl groups with 6 to 20 carbon atoms or aralkyl groups with 7 to 20 carbon atoms.

[0290] In R 55 and R 56 When the bonded divalent group is represented by -Q-, the following groups (11) to (14) can be specifically listed as -Q-.

[0291] -(CH2)4- ……(11)

[0292] -(CH2)5- ……(12)

[0293] -C(CH3)2(CH2)2C(CH3)2- ……(13)

[0294] -C(CH3)2(CH2)3C(CH3)2- ……(14)

[0295] As a squaric acid Salt compound (V), preferably, the following compounds represented by formula (V-1) or formula (V-2). Squaric acid The salt compound (V-1) is in squaric acid R in salt compound (V) 52 and R 53 Compounds that form a dithiophenecyclopentadiene ring by linkage. Squaric acid. The salt compound (V-2) is contained within the squaric acid. R in salt compound (V) 52 With R 53 Compounds with a structure consisting of two unconnected thiophene rings bonded together.

[0296]

[0297] R 51 R 54 R 55 and R 56 With R in equation (V) 51 R 54 R 55 and R 56 The same applies to preferred methods.

[0298] R 52b and R 53b Apart from the fact that they do not connect to form a loop, it is similar to R in equation (V). 52 and R 53 The same applies to preferred methods.

[0299] From the perspectives of visible light transmittance, lightfastness, and solubility in resins and solvents, R 52a and R 53a Preferably, the alkyl group is a straight-chain, branched, or cyclic alkyl group having 1 to 20 carbon atoms, in which oxygen atoms may be present between carbon atoms. In the case of a straight-chain alkyl group, the number of carbon atoms is more preferably 1 to 12; in the case of a branched alkyl group, the number of carbon atoms is more preferably 3 to 10; and in the case of a cyclic alkyl group, the number of carbon atoms is more preferably 5 to 10. 52a and R 53a For example, it is further preferred to select a group from (1a) to (15a), and particularly preferred to select a group (1a), a group (3a), or a group (9a).

[0300] From the perspective of transmittance and lightfastness in the visible light region, R 52a and R 53aPreferably, the phenyl group may have 1 to 5 substituents, or the naphthyl group may have 1 to 7 substituents, or the alkyl group having 1 to 10 carbon atoms. Examples of substituents for the phenyl and naphthyl groups include alkyl groups having 1 to 12 carbon atoms, or alkoxy or alkylamino groups having 1 to 12 carbon atoms (the alkyl group has 1 to 12 carbon atoms), wherein each of the alkyl, alkoxy, or alkylamino groups may contain an unsaturated bond or an oxygen atom between carbon atoms; methyl, tert-butyl, dimethylamino, methoxy, etc., are particularly preferred. The phenyl and naphthyl groups are preferably unsubstituted or have 1 to 3 hydrogen atoms substituted.

[0301] As a phenyl group that can have 1 to 5 substituents, specifically, groups (P1) to (P9) can be listed.

[0302]

[0303] As a naphthyl group, it can have 1 to 7 substituents, specifically, groups (N1) to (N9) can be listed.

[0304]

[0305] As compound (V-1), more specifically, the compounds shown in the table below can be listed. Additionally, the compounds shown in the table below are in squaric acid. The symbols on the left and right sides of the salt skeleton have the same meaning.

[0306] [Table 8]

[0307]

[0308] Among these compounds (V-1), compounds (V-1-5), (V-1-12), etc., are preferred in terms of transmittance in the visible light region and solubility in resin.

[0309] As compound (V-2), more specifically, the compounds shown in the table below can be listed. Additionally, the compounds shown in the table below are in squaric acid. The symbols on the left and right sides of the salt skeleton have the same meaning.

[0310] [Table 9]

[0311]

[0312] Squamous acid Salt compound (V) can be manufactured by known methods. For example, it can be manufactured by the method described in International Publication No. 2019 / 230660.

[0313] <Ammonium compounds>

[0314] The ammonium compound is preferably a compound represented by formula (A1) or formula (A2).

[0315]

[0316] The symbols in equations (A1) and (A2) are as follows.

[0317] R 201 ~R 206 and R 221 ~R 226 Each group can independently be a hydrogen atom, halogen atom, sulfonyl, hydroxyl, cyano, nitro, carboxyl, phosphate, an alkyl group with 1 to 20 carbon atoms that can have an oxygen atom between carbon atoms and can be substituted, or an alkoxy group with 1 to 20 carbon atoms that can have an oxygen atom between carbon atoms and can be substituted, or an aryl group with 6 to 14 carbon atoms that can be substituted, an aralkyl group with 7 to 14 carbon atoms that can be substituted, or a heterocyclic group with 3 to 14 members that can be substituted. This excludes groups formed by the bonding of substituted or unsubstituted amino groups with phenyl groups. Furthermore, in R... 201 ~R 206 and R 221 ~R 226 In this process, two groups bonded to the same nitrogen atom can bond to each other and together with the nitrogen atom to form a 3- to 8-membered heterocycle, and the hydrogen atom bonded to the ring can be replaced by an alkyl group having 1 to 12 carbon atoms.

[0318] R 207 ~R 218 and R 227 ~R 238 Each group is independently a hydrogen atom, a halogen atom, a substituted amino group, an amide group, a cyano group, a nitro group, a carboxyl group, or an alkyl group with 1 to 12 carbon atoms that can be substituted by a halogen atom, or an alkoxy group with 1 to 12 carbon atoms that can be substituted by a halogen atom. In R 207 ~R 218 and R 227 ~R 238 In this ring, two adjacent groups can bond to each other and together with the two carbon atoms of the phenyl group to form a 3- to 8-membered ring, and the hydrogen atom bonded to the ring can be replaced by an alkyl group with 1 to 12 carbon atoms.

[0319] In R 201 ~R 206 and R 221 ~R 226In this context, the substituents that can be substituted include alkyl groups with 1 to 20 carbon atoms, alkoxy groups with 1 to 20 carbon atoms, aryl groups with 6 to 14 carbon atoms, aralkyl groups with 7 to 14 carbon atoms, or heterocyclic groups with 3 to 14 carbon atoms. Examples of substituents include halogen atoms, hydroxyl groups, amino groups, carboxyl groups, sulfonyl groups, cyano groups, and acyloxy groups with 1 to 6 carbon atoms.

[0320] R without forming a loop 207 ~R 218 and R 227 ~R 238 Preferably, each of the atoms is an alkyl group or an alkoxy group having 1 to 12 carbon atoms, which is independently hydrogen, a halogen atom, or an alkyl group having 1 to 12 carbon atoms. The alkyl or alkoxy group preferably has 1 to 6 carbon atoms, more preferably 1 to 4.

[0321] In R 207 ~R 218 and R 227 ~R 238 In this ring, the two adjacent groups bonded together with the two carbon atoms of the phenyl group can form an alicyclic ring, an aromatic ring, or a heterocyclic ring. Examples of heteroatoms include nitrogen, oxygen, and sulfur atoms.

[0322] In R 207 ~R 218 and R 227 ~R 238 In formulas (A1) and (A2), the combination of two adjacent groups bonded together exists in two groups of three phenyl groups bonded to the central nitrogen atom, for a total of six groups. Specifically, in formula (A1), R is... 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 These 6 groups. In equation (A2), R represents... 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 R238 These 6 groups.

[0323] In equation (A1) R 207 ~R 218 R of formula (A2) 227 ~R 238 In this process, the number of groups bonded to two adjacent groups can be one, two or more, or up to six groups. Preferably, each of the three phenyl groups is bonded in one group, for a total of three groups.

[0324] Specifically, the divalent groups bonded to the two adjacent groups mentioned above can be alkylene groups containing one to two nitrogen atoms as heteroatoms and having 1 to 6 carbon atoms with unsaturated bonds between them. More specifically, groups (X-1) to (X-4) can be listed below. It should be noted that the hydrogen atoms in these divalent groups can be replaced by alkyl groups having 1 to 12 carbon atoms.

[0325] -(CH2) n -(n is an integer from 1 to 6) ……(X-1)

[0326] -CH=CH-CH=CH- ……(X-2)

[0327] -CH2-CH=CH- ……(X-3)

[0328] -N=CH-NH- ……(X-4)

[0329] R 207 ~R 218 and R 227 ~R 238 Preferably, each of the elements independently represents a hydrogen atom, a halogen atom, or an alkyl group or an alkoxy group having 1 to 12 carbon atoms. The alkyl or alkoxy group preferably has 1 to 6 carbon atoms, more preferably 1 to 4.

[0330] Additionally, 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 R230 R 223 and R 231 R 224 and R 234 R 225 and R 235 R 226 and R 238 They can bond with each other and together with the nitrogen atom bonded to the phenyl and the two carbon atoms of the phenyl to form a 4- to 8-membered heterocycle, and the hydrogen atom bonded to the ring can be replaced by an alkyl group having 1 to 12 carbon atoms.

[0331] Xa - and Xb - Each can be used independently to represent a monovalent anion.

[0332] In the above, the alkyl group can be linear, branched, cyclic, or a combination of these structures. The same applies to alkyl groups containing alkyl groups in the following aryl groups, and alkyl groups of aralkyl groups. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms, with fluorine and chlorine atoms being preferred.

[0333] In the above, aryl refers to a group bonded via carbon atoms of an aromatic ring (which does not contain heteroatoms) such as a benzene ring, naphthalene ring, or biphenyl ring. Aryl groups include structures where hydrogen atoms bonded to ring atoms other than the carbon atoms contributing to the bond are replaced by alkyl groups, such as tolyl and xylyl.

[0334] In the above, aralkyl refers to a group having an alkyl group bonded to an aromatic ring (wherein, no heteroatoms are present) and bonded via carbon atoms constituting the alkyl group. Aralkyl groups comprise structures in which hydrogen atoms bonded to ring-forming atoms other than the alkyl atoms contributing to the bonding are replaced by alkyl groups.

[0335] In the above, the heterocyclic group is a group bonded via atoms constituting an alicyclic or aromatic ring, wherein the atoms constituting the alicyclic or aromatic ring include carbon atoms and atoms other than carbon atoms. The heterocyclic group comprises a structure in which hydrogen atoms bonded to the ring-constituting atoms other than those contributing to the bonding are replaced by alkyl groups. Examples of atoms other than carbon atoms in the heterocyclic group include oxygen atoms, nitrogen atoms, or sulfur atoms, preferably one to two.

[0336] As Xa - and Xb - Each can be listed independently as Cl - ,Br - I - F - ClO4 - BF4 - PF6- SbF6 - CF3SO3 - CH3C6H4SO3 - 、N[SO2R f ]2 - 、C[SO2R f ]3 - wait.

[0337] Here, R f It is 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, it exhibits good heat resistance, moisture resistance, and other durability, as well as good solubility in organic solvents described later. As such, R... f Examples include perfluoroalkyl groups such as -CF3, -C2F5, -C3F7, and -C4F9, as well as -C2F4H, -C3F6H, and -C4F8H.

[0338] From the viewpoint of moisture resistance, the aforementioned fluoroalkyl group is preferably a perfluoroalkyl group, and more preferably a trifluoromethyl group.

[0339] As Xa - and Xb - Each is preferred to be independent as I - BF 4- SbF6 - PF6 - ClO4 - N[SO2CF3]2 - C[SO2CF3]3 - From the perspective that the difference between its optical properties in dichloromethane solution and its optical properties in resin is small, SbF6 is more preferred. - PF6 - and N[SO2CF3]2 - SbF6 is particularly preferred. - N[SO2CF3]2 - Furthermore, from the viewpoint of light durability, BF is preferred. 4- PF6 - N[SO2CF3]2 - .

[0340] The content of NIR pigment (IR) in the resin film is preferably 0.1 to 25 parts by mass relative to 100 parts by mass of resin, more preferably 0.3 to 15 parts by mass. It should be noted that when two or more compounds are combined, the above content refers to the sum of all compounds.

[0341] Furthermore, when the NIR pigment (IR) contains compounds (A) to (C), the content of compound (A) is preferably 0.1 to 5 parts by mass relative to 100 parts by mass of resin, the content of compound (B) is preferably 0.1 to 5 parts by mass, and the content of compound (C) is preferably 0.1 to 5 parts by mass.

[0342] <Other Pigments>

[0343] In addition to NIR pigments, resin films may also contain other pigments, such as UV pigments.

[0344] As specific examples of UV pigments, the following can be listed: Zazoles, anthocyanins, naphthalenedicarboximides, diazoles, Azides Pigments include azole alkyl groups, naphthalenedicarboxylic acid groups, styryl groups, anthracene groups, cyclic carbonyl groups, and triazole groups. Furthermore, UV pigments can be used alone or in combination with two or more types.

[0345] <Base Material Composition>

[0346] The substrate in this filter can be a single-layer structure or a multi-layer structure. Furthermore, the material used as the substrate can be any transparent material that transmits visible light in the range of 400nm to 700nm; it can be organic or inorganic, without any particular restrictions.

[0347] When the substrate has a single-layer structure, a resin substrate composed of a resin film containing resin and NIR pigment (IR) is preferred.

[0348] When the substrate has a multilayer structure, it is preferable to have a composite substrate containing a resin film of NIR pigment (IR) laminated on at least one main surface of the support. In this case, the support preferably comprises a transparent resin or a transparent inorganic material.

[0349] There are no restrictions on the type of resin used, as long as it is transparent. One or more transparent resins selected from polyester resins, acrylic resins, epoxy resins, olefin-thiol resins, polycarbonate resins, polyether resins, polyaryl ester resins, polysulfone resins, polyethersulfone resins, poly(p-phenylene) resins, polyaryl ether phosphine oxide resins, polyamide resins, polyimide resins, polyamide-imide resins, polyolefin resins, cyclic olefin resins, polyurethane resins, and polystyrene resins can be used. These resins can be used alone or in combination of two or more.

[0350] From the viewpoints of optical properties, glass transition temperature (Tg), and adhesion of the resin film, it is preferable to select one or more resins selected from polyimide resin, polycarbonate resin, polyester resin, and acrylic resin.

[0351] When using multiple compounds as NIR pigments (IR) or other pigments, these compounds can be contained in the same resin film, or they can be contained in different resin films.

[0352] Glass and crystalline materials are preferred as transparent inorganic materials.

[0353] Examples of glasses that can be used as supports include copper-containing absorbing glasses (near-infrared absorbing glasses) such as fluorophosphate glasses and phosphate glasses, soda-lime glass, borosilicate glass, alkali-free glass, and quartz glass.

[0354] From the viewpoint of being able to absorb infrared light (especially in the wavelength range of 900 nm to 1200 nm), phosphate glasses and fluorophosphate glasses are preferred as glass. It should be noted that "phosphate glass" also includes silicate phosphate glasses in which a portion of the glass skeleton is composed of SiO2.

[0355] As glass, chemically strengthened glass can be used, which is obtained by exchanging alkali metal ions with small ionic radii (e.g., Li ions, Na ions) present in the main surface of the glass plate with alkali metal ions with larger ionic radii (e.g., Na ions or K ions for Li ions, and K ions for Na ions) through ion exchange at a temperature below the glass transition temperature.

[0356] Examples of birefringent crystals that can be used as supports include quartz, lithium niobate, and sapphire.

[0357] As a support, inorganic materials are preferred from the perspective of shape stability related to long-term reliability of optical and mechanical properties, and from the perspective of operability in manufacturing filters. Glass and sapphire are particularly preferred.

[0358] The resin film can be formed by dissolving or dispersing a pigment (IR), resin, or resin raw material components, and other components as needed, in a solvent to prepare a coating solution; coating the coating solution onto a support and drying it; and further curing it as needed. The support can be the support included in this filter, or a peelable support used only during the formation of the resin film. Furthermore, the solvent can be any dispersion medium that can be stably dispersed or a solvent that can dissolve the resin.

[0359] Furthermore, to improve voids caused by tiny air bubbles, pits caused by the adhesion of foreign matter, and pinholes during the drying process, the coating liquid may contain surfactants. Additionally, methods such as dip coating, cast coating, or spin coating can be used when applying the coating liquid. By applying the coating liquid onto a support and then drying it, a resin film is formed. Furthermore, if the coating liquid contains transparent resin components, further curing treatments such as thermosetting or photocuring can be performed.

[0360] In addition, resin films can also be manufactured into a film shape by extrusion molding. When the substrate is a single-layer structure (resin substrate) consisting of a resin film containing pigment (IR), the resin film can be used directly as the substrate. When the substrate is a multilayer structure (composite substrate) having a support and a resin film containing pigment (IR) laminated on at least one main surface of the support, the substrate can be manufactured by laminating the film onto the support and integrating it through heat pressing or the like.

[0361] A filter may contain one layer of resin film or two or more layers of resin film. When there are two or more layers of resin film, each layer may have the same composition or different compositions.

[0362] When the substrate is a single-layer structure (resin substrate) composed of a resin film containing pigment (IR), the thickness of the resin film is preferably 20 μm to 150 μm.

[0363] When the substrate is a multilayer structure (composite substrate) having a support and a pigment-containing (IR) resin film laminated on at least one main surface of the support, the thickness of the resin film is preferably 0.3 μm to 20 μm. It should be noted that when the filter has two or more resin films, the total thickness of each resin film is preferably within the above range.

[0364] There are no particular restrictions on the shape of the substrate; it can be in the form of blocks, plates, or films.

[0365] Furthermore, from the viewpoint of reducing warpage during the formation of dielectric multilayer films and reducing the height of optical elements, the thickness of the substrate is preferably 300 μm or less. When the substrate is a resin substrate composed of a resin film, the thickness of the substrate is preferably 50 μm to 300 μm. When the substrate is a composite substrate having a support and a resin film, the thickness of the substrate is preferably 50 μm to 300 μm.

[0366] This filter may include, for example, constituent elements (layers) that provide absorption by inorganic particles that control the transmission and absorption of light within a specific wavelength range. Specific examples of inorganic particles include: ITO (indium tin oxide), ATO (antimony-doped tin oxide), cesium tungstate, and lanthanum boride. ITO particles and cesium tungstate particles have high visible light transmittance and light absorption over a wide range of infrared wavelengths greater than 1200 nm, thus they can be used when infrared light blocking is required.

[0367] [Example]

[0368] Next, the invention will be described in more detail through examples.

[0369] The various optical properties were measured using a UV-Vis spectrophotometer (manufactured by Hitachi High Technology Co., Ltd., model UH-4150).

[0370] It should be noted that the optical properties, unless otherwise specified, are values ​​measured at an incident angle of 0 degrees (the direction perpendicular to the main surface of the filter).

[0371] The pigments used in each example are described below.

[0372] Compound 1 (squamous acid) Salt compound): synthesized according to U.S. Patent Application Publication No. 2014 / 0061505 and International Publication No. 2014 / 088063.

[0373] Compound 2 (phthalocyanine compound): synthesized according to Japanese Patent No. 4081149.

[0374] Compound 3 (squamous acid) Salt compound): Synthesized according to International Publication No. 2017 / 135359.

[0375] Compounds 4–6 (cyanin compounds): synthesized according to Dyes and pigments, 73 (2007), pp. 344–352.

[0376] Compound 7 (squamous acid) Salt compound): Synthesized according to International Publication No. 2019 / 230660.

[0377] Compound 8 (diammonium compound): synthesized according to Japanese Patent Application Publication No. 2014-25016.

[0378] Compound 9 (squamous acid) Salt compound): synthesized with reference to Japanese Patent No. 6197940.

[0379] Compound 10 (squaraine salt compound): Synthesized with reference to the specification of US Patent Application Publication No. 2014 / 0061505 and International Publication No. 2014 / 088063.

[0380] Compound 11 (cyanine compound): S2137 manufactured by FEW Chemicals

[0381] Compound 12 (squaraine salt compound): Synthesized with reference to International Publication No. 2019 / 230660.

[0382] Compound 13 (iminium compound): Synthesized with reference to International Publication No. 2020 / 255927.

[0383] Compound 1

[0384] Compound 2

[0385] Compound 3

[0386] Compound 4

[0387] Compound 5

[0388] Compound 6

[0389] Compound 7

[0390] Compound 8

[0391] Compound 9

[0392] Compound 10

[0393] Compound 11

[0394] Compound 12

[0395] Compound 13

[0396] <Optical Properties of IR Dyes>

[0397] Polyimide resin (C-3G30G manufactured by Mitsubishi Gas Chemical Company, Inc.) is dissolved in an organic solvent (cyclohexanone:γ-butyrolactone = 1:1 by mass) at a concentration of 8.5 mass%.

[0398] Each pigment compound was added to the polyimide resin solution prepared above at a ratio of 6 parts by mass to 100 parts by mass of resin, and the mixture was heated at 50°C while stirring for 2 hours. The pigment-containing resin solution was coated onto a glass substrate (alkali glass, Schott AG D263) and dried to obtain a resin film (coated film) with a thickness of 1 μm.

[0399] The internal spectral transmittance curve was calculated using the spectral transmittance and spectral reflectance curves of the glass plate with the resin film, and normalized to 10% transmittance at the maximum absorption wavelength.

[0400] The optical properties are shown in the table below.

[0401] [Table 10]

[0402]

[0403] <Examples 1-1 to 1-12: Optical Properties of Resin Films>

[0404] The 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% by mass.

[0405] Each compound was added to the polyimide resin solution prepared above in the manner specified in the table below, relative to 100 parts by mass of resin, and the mixture was heated at 50°C while stirring for 2 hours. The pigment-containing resin solution was coated onto a glass substrate (alkali glass, D263 manufactured by Schott AG) and dried to obtain a resin film (coated film) with a thickness of 2 μm.

[0406] The transmission spectrum of the obtained resin film was measured in the wavelength range of 350 nm to 1200 nm at an incident angle of 0 degrees and the reflection spectrum at an incident angle of 5 degrees. The transmittance is expressed by the internal transmittance shown in the following formula.

[0407] Internal transmittance = Measured transmittance / (100 - Reflectance) × 100

[0408] The optical properties are shown in the table below.

[0409] It should be noted that Examples 1-1 to 1-12 are for reference only.

[0410]

[0411] In Examples 1-1 to 1-3, the visible light transmittance is high because only the amount of pigment required to absorb the near-infrared light region that may cause light leakage in the multilayer film is incorporated.

[0412] In Examples 1-4, due to the limited amount of pigment involved, the near-infrared region that may cause light leakage in the multilayer film cannot be completely absorbed.

[0413] In Examples 1-5, although the absorption width in the near-infrared region is wide, the transmittance of visible light is low. This is attributed to the fact that increasing the amount of pigment added expands the absorption width, resulting in continued absorption in the visible light region.

[0414] In Examples 1-6 to 1-9, since only the amount of pigment needed to compensate for light leakage in the multilayer film was added, excellent absorption characteristics and transmittance in the visible light band were exhibited.

[0415] In Examples 1-10 to 1-12, due to the small amount of pigment involved, the near-infrared light region that may cause light leakage in the multilayer film cannot be completely absorbed.

[0416] <Examples 2-1 to 2-4: Optical Properties of Dielectric Multilayer Films>

[0417] The following dielectric multilayer films were designed: 1) a dielectric multilayer film with a total thickness of 3.94 μm obtained by alternately stacking 32 layers of TiO2 and SiO2 films; 2) a dielectric multilayer film with a total thickness of 4.94 μm obtained by alternately stacking 40 layers of TiO2 and SiO2 films; 3) a dielectric multilayer film with a total thickness of 3.76 μm obtained by alternately stacking 30 layers of TiO2 and SiO2 films; and 4) a dielectric multilayer film with a total thickness of 6.31 μm obtained by alternately stacking 50 layers of TiO2 and SiO2 films.

[0418] The optical properties of dielectric multilayer films 1 to 4 are shown in the table below.

[0419] In addition, the spectral transmittance curves of the dielectric multilayer films 1 to 4 are shown in... Figures 5-8 middle.

[0420] It should be noted that Examples 2-1 to 2-4 are for reference only.

[0421] [Table 12]

[0422]

[0423] The dielectric multilayer film 1 has small ripples, but light leakage occurs in the range of 780 nm and beyond.

[0424] The dielectric multilayer film 2 has large ripples, but almost no light leakage occurs in the range of 780 nm and beyond.

[0425] The dielectric multilayer film 3 exhibited light leakage in the range of 800nm ​​to 1000nm, but the ripples were small.

[0426] The dielectric multilayer film 4 did not produce light leakage in the range of 800nm ​​to 1000nm, but the ripples were large.

[0427] <Example 3-1: Optical Characteristics of Filters>

[0428] 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 AG). The resin film of Example 1-1 was formed by spin-coating on another main surface of the glass substrate, and a dielectric multilayer film (anti-reflection film) of alternating SiO2 and TiO2 was formed on the resin film by vapor deposition, thereby fabricating the filter 1.

[0429] <Examples 3-2 to 3-13: Optical Characteristics of Filters>

[0430] Except that the dielectric multilayer film 2 of Example 2-2 is used instead of the dielectric multilayer film 1 of Example 2-1, the filter 2 is fabricated in the same manner as in Example 3-1.

[0431] Except that the resin film of Examples 1-5 was used instead of the resin film of Example 1-1, the filter 3 was made in the same manner as in Example 3-1.

[0432] Except that the resin film of Example 1-2 was used instead of the resin film of Example 1-1, the filter 4 was made in the same manner as in Example 3-1.

[0433] Except that the resin film of Example 1-3 was used instead of the resin film of Example 1-1, the filter 5 was made in the same manner as in Example 3-1.

[0434] Except that the resin film used in Examples 1-6 was used instead of the resin film used in Example 1-1, the filter 6 was made in the same manner as in Example 3-1.

[0435] Except that the resin film used in Examples 1-7 was used instead of the resin film used in Example 1-1, the filter 7 was fabricated in the same manner as in Example 3-1.

[0436] Except that the resin film used in Examples 1-8 was used instead of the resin film used in Example 1-1, the filter 8 was fabricated in the same manner as in Example 3-1.

[0437] Except that the resin film of Examples 1-9 is used instead of the resin film of Example 1-1 and the dielectric multilayer film 3 of Examples 2-3 is stacked instead of the dielectric multilayer film 1 of Example 2-1, the filter 9 is made in the same manner as in Example 3-1.

[0438] Except that the dielectric multilayer film 4 of Example 2-4 is used instead of the dielectric multilayer film 1 of Example 2-1, the filter 10 is fabricated in the same manner as in Example 3-1.

[0439] Except that the resin film of Examples 1-10 was used instead of the resin film of Example 1-1, the filter 11 was made in the same manner as in Example 3-1.

[0440] Except that the resin film of Example 1-11 was used instead of the resin film of Example 1-1, the filter 12 was made in the same manner as in Example 3-1.

[0441] Except that the resin film of Example 1-12 was used instead of the resin film of Example 1-1, the filter 13 was made in the same manner as in Example 3-1.

[0442] The optical characteristics of filters 1 to 13 are shown in the table below.

[0443] It should be noted that Examples 3-1 and 3-4 to 3-9 are examples, while Examples 3-2, 3-3 and 3-10 to 3-13 are comparative examples.

[0444]

[0445] The filter in Example 3-1 has high visible light transmittance, low ripple under a high incident angle of 40 degrees, and can also provide light shielding for a long wavelength range including the near-infrared region of 750nm to 1000nm.

[0446] The dielectric multilayer film of the filter in Example 3-2 has a high incident angle dependence, and low ripple cannot be achieved under a high incident angle of 40 degrees.

[0447] The filter in Example 3-3 has a significantly reduced visible light transmittance due to excessive absorption caused by the pigment.

[0448] The filters in Examples 3-4 to 3-9 have multilayer films with small ripples and resin films that compensate for light leakage on the long wavelength side of the multilayer films, exhibiting excellent optical properties.

[0449] The filter in Example 3-10 has poor reflectivity in the visible light region because it uses a multilayer film with large ripples.

[0450] The filters in Examples 3-11 to 3-13, due to the use of resin films with less pigment, have insufficient light-blocking properties on the long wavelength side and insufficient response to oblique incidence deviation.

[0451] Although the present invention has been described in detail and with reference to specific embodiments, various changes or modifications can be made without departing from the spirit and scope of the invention, as will be apparent to those skilled in the art. This application is based on Japanese Patent Application 2020-188117, filed on November 11, 2020, the contents of which are incorporated herein by reference.

[0452] Industrial practicality

[0453] The filter of this invention exhibits excellent visible light transmittance and good near-infrared light blocking properties, suppressing changes in near-infrared light blocking characteristics under high incident angles. It is useful in applications where high-performance technologies are increasingly being developed, such as in information acquisition devices like conveyor cameras and sensors.

Claims

1. A filter having a substrate and a dielectric multilayer film, the dielectric multilayer film being stacked as the outermost layer on at least one main surface of the substrate, wherein, The substrate has a resin film comprising a pigment (IR) and a resin. The pigment (IR) exhibits maximum absorption wavelength in dichloromethane within the range of 680 nm to 1000 nm, and The filter satisfies all of the following optical properties (i-1) to (i-10): (i-1) On at least one surface of the filter, within a wavelength range of 450 nm to 500 nm, the average reflectance R under the condition of an incident angle of 5 degrees. 450-500(5deg)AVE The average reflectance R is less than 3% and under the condition of an incident angle of 40 degrees. 450-500(40deg)AVE Less than 5%; (i-2) The average reflectance R on at least one surface of the filter, within the wavelength range of 500 nm to 580 nm, under the condition of an incident angle of 5 degrees. 500-580(5deg)AVE The average reflectance R is less than 2.5% and is obtained under the condition of an incident angle of 40 degrees. 500-580(40deg)AVE Below 4%; (i-3) On at least one surface of the filter, satisfying the R 450-500(5deg)AVE >The R 500-580(5deg)AVE And the R 450-500(40deg)AVE >The R 500-580(40deg)AVE Relationship; (i-4) On at least one surface of the filter, within the wavelength range of 450 nm to 580 nm, the maximum reflectivity R under the condition of an incident angle of 5 degrees. 450-580(5deg)MAX The maximum reflectivity R is below 4% and is achieved under the condition of an incident angle of 40 degrees. 450-580(40deg)MAX Below 6%; (i-5) In the wavelength range of 450nm to 500nm, the maximum difference between the transmittance under the condition of 0 degrees of incident angle and the transmittance under the condition of 40 degrees of incident angle is less than 6%. (i-6) In the wavelength range of 500nm to 580nm, the maximum difference between the transmittance under the condition of 0 degrees of incident angle and the transmittance under the condition of 40 degrees of incident angle is less than 5%. (i-7) Average transmittance T in the wavelength range of 450 nm to 580 nm under the condition of 0 degrees incident angle. 450-580(0deg)AVE It is over 88%; (i-8) In the wavelength range of 600nm to 800nm, the absolute value of the difference between the wavelength with a transmittance of 20% under the condition of an incident angle of 0 degrees and the wavelength with a transmittance of 20% under the condition of an incident angle of 40 degrees is less than 10nm. (i-9) In the wavelength range of 600nm to 800nm, the wavelength with a transmittance of 20% under the condition of 0 degrees of incident angle is in the range of 640nm to 690nm. (i-10) The maximum transmittance T in the wavelength range of 750 nm to 1000 nm under the condition of an incident angle of 0 degrees. 750-1000(0deg)MAX The maximum transmittance T is less than 1% and is obtained under the condition of an incident angle of 40 degrees. 750-1000(40deg)MAX It is less than 1%.

2. The filter as described in claim 1, wherein, The resin film satisfies all of the following optical properties (ii-1) to (ii-6): (ii-1) Average internal transmittance T in the wavelength range of 450 nm to 580 nm 450-580AVE It is over 88%; (ii-2) In the wavelength range of 600nm to 700nm, the wavelength with an internal transmittance of 20% is in the range of 640nm to 690nm; (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 It is between 60% and 95%.

3. The filter as described in claim 1 or 2, wherein, The dielectric multilayer film satisfies all of the following optical properties (iv-1) to (iv-8): (iv-1) Average transmittance T in the wavelength range of 450 nm to 580 nm under the condition of 0 degrees incident angle. 450-580(0deg)AVE The average transmittance T is over 90% and is achieved under the condition of an incident angle of 40 degrees. 450-580(40deg)AVE It is over 90%; (iv-2) In the wavelength range of 450 nm to 500 nm, the absolute value of the difference between the average transmittance under the condition of 0 degrees of incident angle and the average transmittance under the condition of 40 degrees of incident angle is less than 3%. (iv-3) In the wavelength range of 500 nm to 580 nm, the absolute value of the difference between the average transmittance under the condition of 0 degrees of incident angle and the average transmittance under the condition of 40 degrees of incident angle is less than 2%. (iv-4) In the wavelength range of 450 nm 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 less than 6%. (iv-5) In the wavelength range of 500 nm to 580 nm, the maximum difference between the transmittance under the condition of 0 degrees of incident angle and the transmittance under the condition of 40 degrees of incident angle is less than 5%. (iv-6) In the wavelength range of 600nm to 800nm, the wavelength with a transmittance of 20% under the condition of 0 degrees of incident angle is in the range of 720nm to 770nm. (iv-7) Maximum transmittance T in the wavelength range of 780 nm to 850 nm under the condition of 0 degrees incident angle. 780-850(0deg)MAX Greater than or equal to 4% and less than 10%; (iv-8) Maximum transmittance T in the wavelength range of 900 nm to 980 nm under the condition of an incident angle of 40 degrees. 900-980(40deg)MAX Greater than or equal to 1% and less than 5%.

4. The filter as described in claim 1 or 2, wherein, The pigment (IR) comprises one or more compounds (A), one or more compounds (B), and one or more compounds (C). The compound (A) has a maximum absorption wavelength in dichloromethane in the range of wavelengths greater than or equal to 690 nm and less than 735 nm. The compound (B) has a maximum absorption wavelength in dichloromethane in the range of wavelengths greater than or equal to 735 nm and less than 835 nm. The compound (C) has a maximum absorption wavelength in dichloromethane in the range of wavelengths above 900 nm and below 1000 nm.

5. The filter as described in claim 4, wherein, The maximum difference between the maximum absorption wavelength of compound (A) and the maximum absorption wavelength of compound (B) is greater than 40 nm.

6. The filter as described in claim 1 or 2, wherein, In the spectral internal transmittance curve measured by dissolving the pigment (IR) in the resin constituting the resin film in such a way that the internal transmittance at the maximum absorption wavelength is 10%, the pigment (IR) satisfies the following characteristic (iii-1): (iii-1) When the maximum absorption wavelength in the resin is set as D [nm] and the average internal transmittance in the range of 450nm to 580nm is set as E, E > 100 - (D / 100).

7. The filter as described in claim 4 or 5, wherein, The compound (A) is selected from squalane. At least one of the group consisting of salt compounds and anthocyanin compounds, wherein compound (B) is selected from squalene. At least one of the group consisting of salt compounds and anthocyanin compounds, wherein compound (C) is selected from squalene. At least one of the group consisting of salt compounds, anthocyanin compounds and ammonium compounds.

8. The filter as described in claim 1 or 2, wherein, The substrate includes a support and the resin film, and the resin film is laminated on at least one main surface of the support.

9. The filter as described in claim 1 or 2, wherein, The resin is a polyimide resin.

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