optical filter

Abstract

The present application relates to an optical filter having a substrate and a dielectric multilayer film laminated on at least one main surface side of the substrate and serving as an outermost layer, wherein the substrate has a resin film containing a pigment (U) having a maximum absorption wavelength in the range of 360 nm to 395 nm in dichloromethane, a pigment (A) having a maximum absorption wavelength in the range of 600 nm to 800 nm in dichloromethane, and a resin, and the optical filter satisfies specific spectral characteristics.

Description

TECHNICAL FIELD

[0001] The present application relates to an optical filter that transmits light in the visible light wavelength range and blocks light in the ultraviolet light wavelength range and the near-infrared light wavelength range. BACKGROUND

[0002] In an imaging device using a solid-state imaging element, in order to reproduce a color tone well and obtain a clear image, an optical filter that transmits light in the visible light region (hereinafter also referred to as "visible light") and blocks light in the ultraviolet light wavelength range (hereinafter also referred to as "ultraviolet light" or "UV"), the near-infrared light wavelength range (hereinafter also referred to as "near-infrared light" or "NIR") is used.

[0003] For such an optical filter, for example, various methods such as a reflection type optical filter that alternately stacks thin films of media having different refractive indexes (a dielectric multilayer film) on one side or both sides of a transparent substrate and reflects light to be blocked by interference of light can be cited. Here, for an optical filter having a dielectric multilayer film, since the optical film thickness of the dielectric multilayer film changes depending on the incident angle of light, there are problems that a change in the spectral transmittance curve caused by the incident angle occurs, light leakage in which the transmittance of ultraviolet light that should be obtained with high reflectance increases at a high incident angle, and noise caused by ultraviolet light reflected by the dielectric multilayer film. When such an optical filter is used, the spectral sensitivity of the solid-state imaging element can be affected by the incident angle. Therefore, there is a demand for an ultraviolet light blocking optical filter that does not substantially affect the visible light transmittance and does not have incident angle dependence.

[0004] For this, in Patent Documents 1 to 4, an optical filter that combines an absorption layer containing a UV absorbing pigment and a NIR absorbing pigment in a transparent resin and a dielectric multilayer film to obtain UV cutoff ability and NIR cutoff ability is described as an optical filter that has little dependence on the incident angle of light in the wavelength of 370 nm to 425 nm.

[0005] PRIOR ART DOCUMENTS

[0006] PATENT DOCUMENTS

[0007] Patent Document 1: Japanese Patent Application Publication No. 2019-16649

[0008] Patent Document 2: Japanese Patent No. 6504176

[0009] Patent Document 3: Japanese Patent No. 6020740

[0010] Patent Document 4: Japanese Patent No. 6256335 SUMMARY

[0011] PROBLEMS TO BE SOLVED BY THE INVENTION

[0012] However, the optical filter described in Patent Documents 1 to 4 has room for improvement in terms of the transmittance of visible light, particularly blue light, and the ultraviolet light blocking property at high incident angles.

[0013] Therefore, an object of the present application is to provide an optical filter having high transmittance of visible light, high blocking property of near-infrared light and ultraviolet light, particularly high transmittance of blue light, and reduced decrease in the ultraviolet light blocking property at high incident angles.

[0014] Means for solving the problem

[0015] The present application provides an optical filter having the following configuration.

[0016] [1] An optical filter having a substrate and a dielectric multilayer film laminated on at least one main surface side of the substrate and serving as an outermost layer, wherein

[0017] the substrate has a resin film containing a pigment (U) having a maximum absorption wavelength in the range of 360 nm to 395 nm in dichloromethane, a pigment (A) having a maximum absorption wavelength in the range of 600 nm to 800 nm in dichloromethane, and a resin, and

[0018] the optical filter satisfies all of the following spectral properties (i-1) to (i-5):

[0019] (i-1) Average transmittance T in the range of wavelengths of 440 nm to 480 nm in the spectral transmittance curve 440-480 is 86% or more;

[0020] (i-2) The wavelength at which the transmittance is 10% under the condition that the wavelength is in the range of 350 nm to 450 nm and the incident angle is 0 degrees is set as UV10 (0度) , the wavelength at which the transmittance is 20% is set as UV20 (0度) , and the wavelength at which the transmittance is 50% is set as UV50 (0度) , and

[0021] the wavelength at which the transmittance is 10% under the condition that the wavelength is in the range of 350 nm to 450 nm and the incident angle is 50 degrees is set as UV10 (50度) , the wavelength at which the transmittance is 20% is set as UV20 (50度) , and the wavelength at which the transmittance is 50% is set as UV50 (50度) ,

[0022] At this time,

[0023] the absolute value of the difference between UV10 (0度) and UV10 (50度) is 3 nm or less,

[0024] UV20 (0度) With UV20 (50度) The absolute value of the difference is less than 4nm.

[0025] UV50 (0度) With UV50 (50度) The absolute value of the difference is less than 4nm;

[0026] (i-3) Average transmittance T in the wavelength range of 400 nm to 440 nm in the spectral transmittance curve 400-440 It is over 40%;

[0027] (i-4) Average transmittance T in the wavelength range of 370 nm to 400 nm in the spectral transmittance curve under the condition of 0 degrees of incident angle. 370-400(0度) Less than 1%;

[0028] (i-5) Average transmittance T in the wavelength range of 370 nm to 400 nm in the spectral transmittance curve under the condition of an incident angle of 50 degrees. 370-400(50度) It is below 0.5%.

[0029] Invention Effects

[0030] According to the present invention, a filter with high visible light transmittance, high near-infrared light and ultraviolet light blocking properties, especially high blue light transmittance, and suppresses the reduction of ultraviolet light blocking properties at high incident angles can be provided. Attached Figure Description

[0031] Figure 1 A cross-sectional view is shown schematically as an example of a filter according to one embodiment.

[0032] Figure 2 A cross-sectional view is shown to schematically illustrate another example of a filter according to one embodiment.

[0033] Figure 3 A cross-sectional view is shown to schematically illustrate another example of a filter according to one embodiment.

[0034] Figure 4 A cross-sectional view is shown to schematically illustrate another example of a filter according to one embodiment.

[0035] Figure 5 A graph showing the spectral transmittance curve of the filter in Example 2-14.

[0036] Figure 6 A graph showing the spectral transmittance curve of the filter in Example 2-15. Detailed Implementation

[0037] Hereinafter, an embodiment of the present application will be described.

[0038] In the present specification, near-infrared absorbing colorant is sometimes simply referred to as "NIR colorant", and ultraviolet absorbing colorant is sometimes simply referred to as "UV colorant".

[0039] In the present specification, a compound represented by formula (I) is referred to as compound (I). The same applies to a compound represented by another formula. A colorant containing compound (I) is also referred to as colorant (I), and the same applies to other colorants. In addition, a group represented by formula (I) is also referred to as group (I), and the same applies to a group represented by another formula.

[0040] In the present specification, internal transmittance refers to transmittance obtained by subtracting the effect of interface reflection from measured transmittance, represented by the formula of measured transmittance / (100-reflectance).

[0041] In the present specification, regarding the transmittance of a substrate, the transmittance of a resin film in the case where a colorant is contained in a resin, in the case where it is described as "transmittance", all of them are "internal transmittance". On the other hand, the transmittance measured by dissolving a colorant in a solvent such as dichloromethane, and the transmittance of a filter having a dielectric multilayer film are measured transmittance.

[0042] In the present specification, for a specific wavelength range, transmittance of, for example, 90% or more means that the transmittance is not less than 90% in the entire wavelength range, that is, the minimum transmittance in the wavelength range is 90% or more. Similarly, for a specific wavelength range, transmittance of, for example, 1% or less means that the transmittance is not more than 1% in the entire wavelength range, that is, the maximum transmittance in the wavelength range is 1% or less. The same applies to internal transmittance. The average transmittance and the average internal transmittance in a specific wavelength range are the arithmetic average of the transmittance and the internal transmittance per 1 nm in the wavelength range.

[0043] In the present specification, "~" indicating a numerical range includes the upper limit and the lower limit.

[0044] <Filter>

[0045] The filter of one embodiment of the present application (hereinafter also referred to as "the present filter") is a filter having a substrate and a dielectric multilayer film stacked on at least one main surface side of the substrate and serving as an outermost layer, and satisfying specific spectral characteristics to be described later. Here, the substrate has a resin film containing a colorant (U) having a maximum absorption wavelength in the range of 360 nm to 395 nm in dichloromethane, a colorant (A) having a maximum absorption wavelength in the range of 600 nm to 800 nm in dichloromethane, and a resin.

[0046] A configuration example of the present filter will be described using the drawings. Figures 1-4 A cross-sectional view of an example of a filter of one embodiment is schematically shown.

[0047] Figure 1 The filter 1A illustrated is an example in which the dielectric multilayer film 30 is provided on one main surface side of the substrate 10. Note that "a specific layer is provided on the main surface side of the substrate" is not limited to a case where the layer is provided in contact with the main surface of the substrate, and includes a case where another functional layer is provided between the substrate and the layer.

[0048] Figure 2 The filter 1B illustrated is an example in which the dielectric multilayer film 30 is provided on both main surface sides of the substrate 10.

[0049] Figure 3 The filter 1C illustrated is an example in which the substrate 10 includes the support 11 and the resin film 12 stacked on one main surface side of the support 11. The filter 1C further includes the dielectric multilayer film 30 on each of the resin film 12 and the main surface side of the support 11 on which the resin film 12 is not stacked.

[0050] Figure 4 The filter 1D illustrated is an example in which the substrate 10 includes the support 11 and the resin film 12 stacked on both main surface sides of the support 11. The filter 1D further includes the dielectric multilayer film 30 on each of the resin films 12.

[0051] The substrate in the filter of the present application includes a pigment (U) having a maximum absorption wavelength in the range of 360 nm to 395 nm in dichloromethane, a pigment (A) having a maximum absorption wavelength in the range of 600 nm to 800 nm in dichloromethane, and a resin. The pigment (U) is a UV pigment, and the pigment (A) is a NIR pigment. By the substrate containing pigments that absorb ultraviolet light and near-infrared light, the decrease in spectral properties of the dielectric multilayer film at a high angle of incidence, such as the generation of light leakage, noise, or the like in the ultraviolet light region and the near-infrared light region, can be suppressed by the absorption characteristics of the substrate. Each of the pigments and the resin will be described later.

[0052] The filter of the present application satisfies all of the following spectral properties (i-1) to (i-5):

[0053] (i-1) Average transmittance T in the range of wavelengths of 440 nm to 480 nm in a spectral transmittance curve 440-480 is 86 % or more;

[0054] (i-2) A wavelength at which the transmittance is 10 % under the condition where the wavelength is in the range of 350 nm to 450 nm and the angle of incidence is 0 degree is set to UV10 (0度)the wavelength at 10% transmittance is set as UV10 (0度) the wavelength at 50% transmittance is set as UV50 (0度) and

[0055] the wavelength at 10% transmittance in the range of wavelengths of 350 nm to 450 nm and at an incident angle of 50 degrees is set as UV10 (50度) the wavelength at 20% transmittance is set as UV20 (50度) the wavelength at 50% transmittance is set as UV50 (50度) ,

[0056] At this time,

[0057] UV10 (0度) is 3 nm or less, (50度)

[0058] UV20 (0度) is 4 nm or less, (50度)

[0059] UV50 (0度) is 4 nm or less; (50度)

[0060] (i-3) the average transmittance T in the range of wavelengths of 400 nm to 440 nm in the spectral transmittance curve 400-440 is 40% or more;

[0061] (i-4) the average transmittance T in the range of wavelengths of 370 nm to 400 nm in the spectral transmittance curve at an incident angle of 0 degrees 370-400(0度) is 1% or less;

[0062] (i-5) the average transmittance T in the range of wavelengths of 370 nm to 400 nm in the spectral transmittance curve at an incident angle of 50 degrees 370-400(50度) is 0.5% or less.

[0063] The present filter satisfying all the spectral properties (i-1) to (i-5) is a filter in which the ultraviolet light blocking property, particularly the decrease in the ultraviolet light blocking property at a high incident angle, is suppressed while the visible light transmittance, particularly the blue light transmittance, is well maintained.

[0064] By satisfying the spectral property (i-1), it means that the transmittance in the visible light region is excellent. The T 440-480 of the spectral property (i-1) is preferably 87% or more, more preferably 89% or more.

[0065] ​​​By satisfying the spectral characteristic (i-2), it means that the shift is small even at a high angle of incidence before and after the UV absorption starting wavelength band of 350 nm to 450 nm, and color reproducibility is excellent. In the spectral characteristic (i-2), the absolute value of the difference between UV10 (0度) and UV20 (50度) is preferably 2.5 nm or less, the absolute value of the difference between UV20 (0度) and UV30 (50度) is preferably 3 nm or less, and the absolute value of the difference between UV30 (0度) and UV50 (50度) is preferably 3 nm or less.

[0066] By satisfying the spectral characteristic (i-3), it means that the transmittance of blue light is excellent before the UV absorption starting wavelength band of 400 nm to 440 nm. The T 400-440 of the spectral characteristic (i-3) is preferably 45% or more, and more preferably 50% or more.

[0067] By satisfying the spectral characteristic (i-4), it means that the light blocking property is high in the UV absorption wavelength band of 370 nm to 400 nm. The T 370-400(0度) of the spectral characteristic (i-4) is preferably 0.5% or less.

[0068] By satisfying the spectral characteristic (i-5), it means that light leakage does not easily occur even at a high angle of incidence in the UV absorption wavelength band of 370 nm to 400 nm, and the light blocking property is high. The T 370-400(50度) of the spectral characteristic (i-5) is preferably 0.1% or less.

[0069] The optical filter of the present application preferably further satisfies the following spectral characteristic (i-6).

[0070] (i-6) When the wavelength at which the transmittance is 10% in the range of 350 nm to 450 nm and at an incident angle of 0 degrees is set to UV10 (0度) , and the wavelength at which the transmittance is 70% is set to UV70 (0度) , the absolute value of the difference between UV10 (0度) and UV70 (0度) is 16 nm or less.

[0071] By satisfying the spectral characteristic (i-6), it means that the slope of the spectral transmittance curve is steep before and after the UV absorption starting wavelength band of 350 nm to 450 nm. The absolute value of the difference between UV10 (0度) and UV70 (0度) in the spectral characteristic (i-6) is more preferably 14 nm or less, and particularly preferably 13 nm or less.

[0072] The following describes the base material and the dielectric multilayer film. The present filter is designed, for example, so that the base material has an absorption ability with respect to ultraviolet light and near-infrared light, and satisfies the above-described spectral characteristics (i-1) to (i-5) through the absorption characteristics of the base material and the reflection characteristics of the dielectric multilayer film.

[0073] <base material>

[0074] In the filter of the present application, the base material has a resin film containing a pigment (U), a pigment (A) described later, and a resin.

[0075] <UV pigment>

[0076] The pigment (U) is a UV pigment having a maximum absorption wavelength in the range of 360 nm to 395 nm in dichloromethane. By containing this pigment, ultraviolet light can be effectively cut off.

[0077] The pigment (U) preferably has specific spectral characteristics in the resin. Specifically, it is preferable that all of the following spectral characteristics (ii-1) to (ii-6) are satisfied in the spectral transmittance curve of a coated film obtained by dissolving the pigment (U) in a resin and coating it on an alkali glass plate. Note that, as the resin, the same resin as contained in the base material is preferable.

[0078] (ii-1) Average transmittance T in the range of wavelengths of 400 nm to 440 nm 400-440 is 40% or more;

[0079] (ii-2) Average transmittance T in the range of wavelengths of 370 nm to 400 nm 370-400 is 5% or less;

[0080] (ii-3) Transmittance T at a wavelength of 400 nm 400 is 7% or less;

[0081] (ii-4) Transmittance T at a wavelength of 390 nm 390 is 5% or less;

[0082] (ii-5) Transmittance T at a wavelength of 380 nm 380 is 5% or less;

[0083] (ii-6) Transmittance T at a wavelength of 370 nm 370 is 5% or less.

[0084] By satisfying the spectral characteristic (ii-1), it means that the transmittance of blue light is excellent before the UV absorption starting wavelength band of 400 nm to 440 nm. The T 400-440 is more preferably 45% or more, and particularly preferably 50% or more.

[0085] By satisfying the spectral property (ii-2), it means that the light blocking property is high in the UV absorption wavelength band of 370 nm to 400 nm. The transmittance T 370-400 More preferably, it is 3% or less, and particularly preferably, it is 2% or less.

[0086] By satisfying the spectral property (ii-3), it means that the transmittance at 400 nm which is the UV absorption starting wavelength is low, and thus the light blocking property on the short wavelength side thereof is high. The transmittance T 400 More preferably, it is 5% or less, and particularly preferably, it is 2% or less.

[0087] By satisfying the spectral properties (ii-4) to (ii-6), in the wavelength band of 370 nm to 390 nm in which light is easily leaked because it cannot be completely blocked by a dielectric multilayer film at a high incident angle, the light blocking property can be ensured by absorption.

[0088] The transmittance T 390 More preferably, it is 3% or less, and particularly preferably, it is 1% or less.

[0089] The transmittance T 380 More preferably, it is 3% or less, and particularly preferably, it is 1% or less.

[0090] The transmittance T 370 More preferably, it is 3% or less, and particularly preferably, it is 1% or less.

[0091] For the pigment (U), it is preferable that the following spectral property (ii-7) is also satisfied in the spectral transmittance curve of the above-mentioned coated film.

[0092] (ii-7) The average internal transmittance T 440-480 is 79% or more.

[0093] By satisfying the spectral property (ii-7), it means that the absorption of the pigment itself does not cause a loss in the transmittance in the visible light region. The transmittance T 440-480 More preferably, it is 80% or more, and particularly preferably, it is 81% or more.

[0094] In addition, as the pigment (U), it is preferable to satisfy the following spectral property (iii-1).

[0095] (iii-1) In a spectral transmittance curve determined by dissolving the pigment (U) in dichloromethane in such a manner that the transmittance at the maximum absorption wavelength is 10%, the wavelength at which the transmittance in the range of 350 nm to 450 nm is 10% is set as UV10, and the wavelength at which the transmittance is 70% is set as UV70, and in this case, the absolute value of the difference between UV10 and UV70 is 25 nm or less.

[0096] By satisfying the spectral property (iii-1), it means that the slope of the spectral transmittance curve is steep around the UV absorption starting wavelength in the range of 350 nm to 450 nm. Thereby, more of the desired blue light can be transmitted, and the ultraviolet light which is intended to be blocked can be effectively blocked.

[0097] As the absolute value of the difference between UV10 and UV70 in the spectral property (iii-1), it is more preferable that it be 22 nm or less.

[0098] The pigment (U) can be used alone or in combination with two or more kinds in the base material, but from the viewpoint that the ultraviolet light can be more effectively blocked with a small amount, it is preferable that two or more kinds of pigments (U) having different maximum absorption wavelengths be combined. In the case where two or more kinds of pigments (U) are combined, it is not necessary that each compound must have the properties of the pigment (U), as long as the mixture has the properties of the pigment (U).

[0099] As the pigment (U), it is more preferable that a pigment (Ul) having a maximum absorption wavelength in the range of 370 nm to 385 nm in dichloromethane be used. In the case where the base material contains the pigment (Ul), it is preferable that a pigment (U2) having a maximum absorption wavelength in the range of 385 nm to 405 nm in dichloromethane be further contained. The maximum absorption wavelengths of the pigment (Ul) and the pigment (U2) in the resin are preferably different, and the absolute value of the difference between the maximum absorption wavelengths of the pigment (Ul) and the pigment (U2) in the resin is preferably 10 nm or more and 15 nm or less, and more preferably 10 nm or more and 14 nm or less.

[0100] By combining UV pigments having different maximum absorption wavelengths, the ultraviolet light can be more effectively blocked with a small amount.

[0101] As the pigment (U), the following can be exemplified: oxazole pigments, merocyanine pigments, cyanine pigments, naphthalimide pigments, oxadiazole pigments, oxazine pigments, oxazolidine pigments, naphthalic acid pigments, styryl pigments, anthracene pigments, cyclic carbonyl pigments, triazole pigments, and the like. Among these, oxazole pigments, merocyanine pigments, and more preferably merocyanine pigments are preferable. oxazole pigments, merocyanine pigments, and more preferably merocyanine pigments.

[0102] Furthermore, from the viewpoint of obtaining filters with excellent lightfastness, it is particularly preferable to use two or more anthocyanin pigments with different maximum absorption wavelengths. NIR pigments (A) are prone to deterioration when used in combination with UV pigments, but this deterioration can be prevented by using two or more anthocyanin pigments as UV pigments.

[0103] As a pigment (U), anthocyanin pigment represented by the following formula (M) is particularly preferred.

[0104]

[0105] The symbols in equation (M) are as follows.

[0106] R 1 This indicates a monovalent hydrocarbon group with 1 to 12 carbon atoms that can have substituents.

[0107] As substituents, alkoxy, acyl, acyloxy, cyano, dialkylamino, or chlorine atoms are preferred. The number of carbon atoms in the aforementioned alkoxy, acyl, acyloxy, and dialkylamino groups is preferably 1 to 6.

[0108] R as a non-substituent 1 Specifically, the preferred alkyl groups having 1 to 12 carbon atoms in which a portion of the hydrogen atom can be replaced by an aliphatic ring, an aromatic ring, or an alkenyl group; cycloalkyl groups having 3 to 8 carbon atoms in which a portion of the hydrogen atom can be replaced by an aromatic ring, an alkyl group, or an alkenyl group; and aryl groups having 6 to 12 carbon atoms in which a portion of the hydrogen atom can be replaced by an aliphatic ring, an alkyl group, or an alkenyl group.

[0109] In R 1 When the alkyl group is unsubstituted, it can be straight-chain or branched, and more preferably has 1 to 6 carbon atoms.

[0110] In R 1 When the alkyl group having 1 to 12 carbon atoms is in the case where a portion of the hydrogen atom is replaced by an aliphatic ring, aromatic ring, or alkenyl group, it is more preferably an alkyl group having 1 to 4 carbon atoms that has a cycloalkyl group having 3 to 6 carbon atoms, or an alkyl group having 1 to 4 carbon atoms that is substituted by a phenyl group, and particularly preferably an alkyl group having 1 or 2 carbon atoms that is substituted by a phenyl group. It should be noted that an alkyl group substituted by a phenyl or alkenyl group refers to a group that is phenyl or alkenyl in its entirety but does not have an unsaturated bond between the 1 and 2 positions, such as allyl, 3-butenyl, etc.

[0111] Preferred R 1 An alkyl group having 1 to 6 carbon atoms, in which a portion of a hydrogen atom can be replaced by a cycloalkyl or phenyl group. Particularly preferred is R. 1 Alkyl groups having 1 to 6 carbon atoms, specifically including: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, etc.

[0112] R 2 ~R 5 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. The number of carbon atoms of the alkyl group and the alkoxy group is preferably 1 to 6, more preferably 1 to 4.

[0113] R 2 and R 3 at least one of which is preferably an alkyl group, more preferably both are alkyl groups. In the case where R 2 or R 3 is not an alkyl group, it is preferably a hydrogen atom. R 2 and R 3 are particularly preferably both alkyl groups having 1 to 6 carbon atoms.

[0114] R 4 and R 5 at least one of which is preferably a hydrogen atom, more preferably both are hydrogen atoms. In the case where R 4 or R 5 is not a hydrogen atom, it is preferably an alkyl group having 1 to 6 carbon atoms.

[0115] Y represents a methylene group substituted with R 6 and R 7 or an oxygen atom.

[0116] R 6 and R 7 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms.

[0117] X represents any one of divalent groups represented by the following formulae (X1) to (X5).

[0118]

[0119] R 8 and R 9 each independently represents a monovalent hydrocarbon group having 1 to 12 carbon atoms which can have a substituent, R 10 ~R 19 each independently represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms which can have a substituent.

[0120] As the substituent of R 8 ~R 19 , the same substituents as those in R 1 can be listed, and the preferable modes are also the same. In the case where R 8 ~R 19 is a hydrocarbon group having no substituent, the same modes as those of R 1 having no substituent can be listed.

[0121] In formula (X1), R 8 and R 9 may be different groups, but are preferably the same group. In the case where R 8 and R 9 are unsubstituted alkyl groups, they can be linear or branched, and the number of carbon atoms is preferably from 1 to 6.

[0122] R 8 and R 9 are each a hydrogen atom, or an alkyl group having from 1 to 6 carbon atoms which can be substituted by a cycloalkyl group or a phenyl group. Particularly preferably, R 8 and R 9 are each an alkyl group having from 1 to 6 carbon atoms, and specifically, for example, there can be mentioned methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, and the like.

[0123] In formula (X2), R 10 and R 11 are each preferably an alkyl group having from 1 to 6 carbon atoms, and R 10 and R 11 are particularly preferably the same alkyl group.

[0124] In formula (X3), R 12 and R 15 are each preferably a hydrogen atom or an alkyl group having from 1 to 6 carbon atoms which has no substituent. Two groups R 13 and R 14 bonded to the same carbon atom are preferably each a hydrogen atom or an alkyl group having from 1 to 6 carbon atoms.

[0125] In formula (X4), two groups R 16 and R 17 bonded to the same carbon atom are each preferably a hydrogen atom or an alkyl group having from 1 to 6 carbon atoms, and R 18 and R 19 are each preferably a hydrogen atom or an alkyl group having from 1 to 6 carbon atoms.

[0126] As the compound represented by formula (M), there are preferably compounds in which Y is an oxygen atom, X is group (X1), group (X2) or group (X5); and compounds in which Y is unsubstituted methylene, and X is group (X1), group (X2) or group (X5).

[0127] As specific examples of the compound (M) which can be used as the pigment (U), there can be mentioned the compounds shown in the following table.

[0128] Table 1

[0129] Color code [R 1 ]]> [R 2 ]]> [R 3 ]]> [R 4 ]] [R 5 ]]> Y X [R 10 ]]> [R 11 ]]> M-1-1 <![CDATA[-CH(CH3)2]]> H H H H -O- X5 - - M-1-2 <![CDATA[-CH(CH3)2]]> H H H H -CH2- X5 - - M-1-3 <![CDATA[-CH(CH3)2]]> H H H H -O- X2 -CH3 -CH3 M-1-4 <![CDATA[-CH(CH3)2]]> H H H H -CH2- X2 -CH3 -CH3 M-1-5 -CH3 H H H H -O- X5 - - M-1-6 -CH3 H H H H -CH2- X5 - - M-1-7 -CH3 H H H H -O- X2 -CH3 -CH3 M-1-8 -CH3 H H H H -CH2- X2 -CH3 -CH3 M-1-9 -C2H5 H H H H -O- X5 - - M-1-10 -C2H5 H H H H -CH2- X5 - - M-1-11 -C2H5 H H H H -O- X2 -CH3 -CH3 M-1-12 -C2H5 H H H H -CH2- X2 -CH3 -CH3 M-1-13 - -NHC3H7 H H H H -O- X5 - - M-1-14 - -NHC3H7 H H H H -CH2- X5 - - M-1-15 - -NHC3H7 H H H H -O- X2 -CH3 -CH3 M-1-16 - -NHC3H7 H H H H -CH2- X2 -CH3 -CH3 M-1-17 H H H H H -O- X5 - - M-1-18 H H H H H -CH2- X5 - - M-1-19 H H H H H -O- X2 -CH3 -CH3 M-1-20 H H H H H -CH2- X2 -CH3 -CH3

[0130] Table 2

[0131] Color code [R 1 ]]> [R 2 ]]> [R 3 ]]> [R 4 ]]> [R 5 ]]> Y X [R 10 ]]> [R 11 ]]> M-1-21 -CH2CH2CH2- -CH3 -CH3 H H -O- X5 - - M-1-22 -CH2CH2CH2- -CH3 -CH3 H H -CH2- X5 - - M-1-23 -CH2CH2CH2- -CH3 -CH3 H H -O- X2 -CH3 -CH3 M-1-24 -CH2CH2CH2- -CH3 -CH3 H H -CH2- X2 -CH3 -CH3 M-1-25 -CH3 -CH3 -CH3 H H -O- X5 - - M-1-26 -CH3 -CH3 -CH3 H H -CH2- X5 - - M-1-27 -CH3 -CH3 -CH3 H H -O- X2 -CH3 -CH3 M-1-28 -CH3 -CH3 -CH3 H H -CH2- X2 -CH3 -CH3 M-1-29 -C2H5 -CH3 -CH3 H H -O- X5 - - M-1-30 -C2H5 -CH3 -CH3 H H -CH2- X5 - - M-1-31 -C2H5 -CH3 -CH3 H H -O- X2 -CH3 -CH3 M-1-32 -C2H5 -CH3 -CH3 H H -CH2- X2 -CH3 -CH3 M-1-33 - -NHC3H7 -CH3 -CH3 H H -O- X5 - - M-1-34 - -NHC3H7 -CH3 -CH3 H H -CH2- X5 - - M-1-35 - -NHC3H7 -CH3 -CH3 H H -O- X2 -CH3 -CH3 M-1-36 - -NHC3H7 -CH3 -CH3 H H -CH2- X2 -CH3 -CH3 M-1-37 H -CH3 -CH3 H H -O- X5 - - M-1-38 H -CH3 -CH3 H H -CH2- X5 - - M-1-39 H -CH3 -CH3 H H -O- X2 -CH3 -CH3 M-1-40 H -CH3 -CH3 H H -CH2- X2 -CH3 -CH3

[0132] As specific examples of the compound (M) which can be used as the pigment (U1), the compounds shown in the following table can be given.

[0133] Table 3

[0134] Color code [R 1 ]]> [R 2 ]] [R 3 ]]> [R 4 ]]> [R 5 ]]> Y X [R 10 ]]> [R 11 ]]> M-1-3 <![CDATA[-CH(CH3)2]]> H H H H -O- X2 -CH3 -CH3 M-1-4 <![CDATA[-CH(CH3)2]]> H H H H -CH2- X2 -CH3 -CH3 M-1-7 -CH3 H H H H -O- X2 -CH3 -CH3 M-1-8 -CH3 H H H H -CH2- X2 -CH3 -CH3 M-1-11 -C2H5 H H H H -O- X2 -CH3 -CH3 M-1-12 -C2H5 H H H H -CH2- X2 -CH3 -CH3 M-1-15 - -NHC3H7 H H H H -O- X2 -CH3 -CH3 M-1-16 - -NHC3H7 H H H H -CH2- X2 -CH3 -CH3 M-1-19 H H H H H -O- X2 -CH3 -CH3 M-1-20 H H H H H -CH2- X2 -CH3 -CH3 M-1-23 <![CDATA[-CH(CH3)2]]> -CH3 -CH3 H H -O- X2 -CH3 -CH3 M-1-24 <![CDATA[-CH(CH3)2]]> -CH3 -CH3 H H -CH2- X2 -CH3 -CH3 M-1-27 -CH3 -CH3 -CH3 H H -O- X2 -CH3 -CH3 M-1-28 -CH3 -CH3 -CH3 H H -CH2- X2 -CH3 -CH3 M-1-31 -C2H5 -CH3 -CH3 H H -O- X2 -CH3 -CH3 M-1-32 -C2H5 -CH3 -CH3 H H -CH2- X2 -CH3 -CH3 M-1-35 - -NHC3H7 -CH3 -CH3 H H -O- X2 -CH3 -CH3 M-1-36 - -NHC3H7 -CH3 -CH3 H H -CH2- X2 -CH3 -CH3 <!-- 9 -->]]> M-1-39 H -CH3 -CH3 H H -O- X2 -CH3 -CH3 M-1-40 H -CH3 -CH3 H H -CH2- X2 -CH3 -CH3

[0135] As specific examples of the compound (M) which can be used as the pigment (U2), the compounds shown in the following table can be given.

[0136] Table 4

[0137] Color code [R 1 ]]> [R 2 ]]> [R 3 ]]> [R 4 ]]> [R 5 ]]> Y X [R 8 ]]> [R 9 ]] M-1-1 -CH2CH2CH2- H H H H -O- X5 - - M-1-2 <![CDATA[-CH(CH3)2]]> H H H H -CH2- X5 - - M-1-5 -CH3 H H H H -O- X5 - - M-1-6 -CH3 H H H H -CH2- X5 - - M-1-9 -C2H5 H H H H -O- X5 - - M-1-10 -C2H5 H H H H -CH2- X5 - - M-1-13 - -NHC3H7 H H H H -O- X5 - - M-1-14 - -NHC3H7 H H H H -CH2- X5 - - M-1-17 H H H H H -O- X5 - - M-1-18 H H H H H -CH2- X5 - - M-1-21 -CH2CH2CH2- -CH3 -CH3 H H -O- X5 - - M-1-22 <![CDATA[-CH(CH3)2]]> -CH3 -CH3 H H -CH2- X5 - - M-1-25 -CH3 -CH3 -CH3 H H -O- X5 - - M-1-26 -CH3 -CH3 -CH3 H H -CH2- X5 - - M-1-29 -C2H5 -CH3 -CH3 H H -O- X5 - - M-1-30 -C2H5 -CH3 -CH3 H H -CH2- X5 - - M-1-33 - -NHC3H7 -CH3 -CH3 H H -O- X5 - - M-1-34 - -NHC3H7 -CH3 -CH3 H H -CH2- X5 - - M-1-37 H -CH3 -CH3 H H -O- X5 - - M-1-38 H -CH3 -CH3 H H -CH2- X5 - - M-2-1 -CH3 H H H H -O- X1 -CH3 -CH3 M-2-2 -C2H5 H H H H -O- X1 -CH3 -CH3 M-2-3 - -NHC3H7 H H H H -O- X1 -CH3 -CH3 M-2-4 <![CDATA[-CH(CH3)2]]> H H H H -O- X1 -CH3 -CH3 M-2-5 -CH3 -CH3 -CH3 H H -O- X1 -CH3 -CH3 M-2-6 -C2H5 -CH3 -CH3 H H -O- X1 -CH3 -CH3 M-2-7 - -NHC3H7 -CH3 -CH3 H H -O- X1 -CH3 -CH3 M-2-8 <![CDATA[-CH(CH3)2]]> -CH3 -CH3 H H -O- X1 -CH3 -CH3

[0138] Among these compounds, as the compound (M), from the viewpoints of solubility in a resin or a solvent, visible light transmittance, and particularly, satisfaction of the spectral characteristic (iii-1), and the like, the compound (M-1-2), the compound (M-1-10), the compound (M-1-24), the compound (M-1-28), and the like are preferred. In addition, in the case where two kinds of compounds (M) different in maximum absorption wavelength are used in combination, the combination of the compound (M-1-28) and the compound (M-1-2), the combination of the compound (M-1-28) and the compound (M-1-10), the combination of the compound (M-1-24) and the compound (M-1-2), and the combination of the compound (M-1-24) and the compound (M-1-10) are preferred. Note that the compound (M) can be produced by a publicly known method.

[0139] The content of the UV pigment (U) in the resin film is preferably within a range where the product of the total content of the pigments (U) and (A) and the thickness of the resin film is preferably 100 (mass% · μm) or less, more preferably 80 (mass% · μm) or less, further preferably 70 (mass% · μm) or less, particularly preferably 50 (mass% · μm) or less. When the added amount of the UV pigment is increased, the properties of the resin are likely to be deteriorated, and as a result, the adhesion to the dielectric multilayer film is likely to be deteriorated. In addition, the glass transition temperature of the resin is likely to be lowered, and the heat resistance is likely to be deteriorated. If the product of the total content of the pigments and the thickness of the resin film is within the above range, such problems can be prevented. In addition, from the viewpoint of satisfaction of the desired spectral characteristics, the product of the content and the thickness is preferably 10 (mass% · μm) or more, more preferably 15 (mass% · μm) or more.

[0140] From the viewpoint of satisfying the above range, the content of the UV pigment (U) in the resin film is preferably 5 to 25 parts by mass, more preferably 5 to 20 parts by mass, relative to 100 parts by mass of the resin. If the content of the UV pigment (U) in the resin film is within such a range, the above problems can be avoided without degrading the resin properties.

[0141] <NIR pigment>

[0142] In the filter of the present invention, the substrate contains the above pigment (U) and pigment (A).

[0143] The pigment (A) is a NIR pigment having a maximum absorption wavelength in the range of 600 nm to 800 nm in dichloromethane. By containing this pigment, infrared light can be effectively blocked.

[0144] As the pigment (A), it is preferably selected from the group consisting of squaraine pigments, cyanine pigments, phthalocyanine pigments, naphthalocyanine pigments, dithiol metal complex pigments, azo pigments, polymethine pigments, phthalide pigments, naphthoquinone pigments, anthraquinone pigments, indophenol pigments, pyran pigments, thiopyran pigments, croconic acid pigments, tetradehydrocholine pigments, triphenylmethane pigments, ammonium pigments, and diammonium pigments.

[0145] As the pigment (A), it preferably contains at least one pigment selected from squaraine pigments, phthalocyanine pigments, and cyanine pigments. Among these NIR pigments, from the spectral viewpoint, squaraine pigments and cyanine pigments are preferred, and from the durability viewpoint, phthalocyanine pigments are preferred.

[0146] As the squaraine pigment, a compound represented by the following formula (I) is preferred.

[0147]

[0148] In the formula (I), the symbols are as described below:

[0149] R 24 and R 26 each independently represent a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyloxy group having 1 to 10 carbon atoms, -NR 27 R 28 (R 27 and R 28 each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, -C(=O)-R 29 (R29 (Hydrogen atom, alkyl group with 1 to 20 carbon atoms that may have substituents, aryl group with 6 to 11 carbon atoms that may have substituents, or aralkyl group with 7 to 18 carbon atoms that may have substituents and may have oxygen atoms between carbon atoms), -NHR 30 or -SO2-R 30 (R 30 Each of the groups consisting of one or more hydrogen atoms may 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 of 1 to 25 carbon atoms (hydrocarbon groups), 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).

[0150]

[0151] R 21 and R 22 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.

[0152] For R in the case of forming heterocyclic A 21 and R 22 As for R 21 and R 22 The bonded divalent group -Q- indicates that the hydrogen atom can be substituted by an alkyl group with 1 to 6 carbon atoms, an aryl group with 6 to 10 carbon atoms, or an alkylene group with 1 to 10 carbon atoms that can have a substituent, or a hydrogen atom can be substituted by an alkyl group with 1 to 6 carbon atoms, an aryl group with 6 to 10 carbon atoms, or an alkylene group with 1 to 10 carbon atoms that can have a substituent.

[0153] For R in the case of forming heterocyclic B 22 and R 25 And R in the case of forming heterocyclic C 21 and R 23 As for R 22 and R 25 The bonded divalent group -X 1 -Y 1 -and R 21 and R 23 The bonded divalent group -X 2 -Y 2- (one 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 represented by any one selected from the group consisting of the following formulas (1y) to (5y). In the case where X 1 and X 2 each is a group represented by the following formula (2x), Y 1 and Y 2 each can be a single bond, in which case an oxygen atom can be present between the carbon atoms.

[0154]

[0155] In formula (1x), 4 Z each independently represents a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or -NR 38 R 39 (R 38 and R 39 each independently represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms). R 31 to R 36 each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 10 carbon atoms, R 37 represents an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms.

[0156] R 27 , R 28 , R 29 , R 31 to R 37 , R 21 to R 23 and R 25 each can be bonded to any one of the others to form a 5-membered ring or a 6-membered ring. R 31 and R 36 may be directly bonded, R 31 and R 37 may be directly bonded.

[0157] R 21 and R 22 each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms which can have a substituent, an allyl group which can have a substituent, an aryl group having 6 to 11 carbon atoms which can have a substituent, or an aralkyl group having 6 to 11 carbon atoms which can have a substituent. R 23 and R 25each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms.

[0158] As the compound (I), for example, from the viewpoint of improving the visible light transmittance, a compound represented by formula (I-1) is preferred.

[0159]

[0160] The definitions of the symbols in formula (I-1) are the same as those of the same symbols in formula (I), and the preferred modes are also the same.

[0161] In the compound (I-1), as X 1 , a group (2x) is preferred, and as Y 1 , a single bond or a group (ly) is preferred. In this case, as R 31 ~R 36 , a hydrogen atom or an alkyl group having 1 to 3 carbon atoms is preferred, and a hydrogen atom or a methyl group is more preferred. Note that, as -Y 1 -X 1 -, specifically, a divalent organic group represented by formulae (11-1) to (12-3) can be exemplified.

[0162] -C(CH3)2-CH(CH3)- (11-1)

[0163] -C(CH3)2-CH2- (11-2)

[0164] -C(CH3)2-CH(C2H5)- (11-3)

[0165] -C(CH3)2-C(CH3)(nC3H7)- (11-4)

[0166] -C(CH3)2-CH2-CH2- (12-1)

[0167] -C(CH3)2-CH2-CH(CH3)- (12-2)

[0168] -C(CH3)2-CH(CH3)-CH2- (12-3)

[0169] In addition, in the compound (I-1), from the viewpoint of solubility, heat resistance, and steepness of the change in the vicinity of the boundary between the visible light region and the near infrared light region in the spectral transmittance curve, R 21 is more preferably independently a group represented by formula (4-1) or formula (4-2).

[0170]

[0171] In formula (4-1) and formula (4-2), R 71 ~R 75 independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms.

[0172] In compound (I-1), from the viewpoint of improving the visible light transmittance, particularly the transmittance of light in the range of wavelength 430 nm to 550 nm, R 24 is preferably -NH-SO2-R 30 . The compound in which R 24 is -NH-SO2-R 30 in compound (I-1) is shown in formula (I-12).

[0173]

[0174] R 23 and R 26 in compound (I-12) are independently preferably a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms, and more preferably each is a hydrogen atom.

[0175] In compound (I-12), from the viewpoint of light resistance, R 30 is independently preferably an alkyl group having 1 to 12 carbon atoms which can have a branched chain, an alkoxy group having 1 to 12 carbon atoms which can have a branched chain, or a hydrocarbon group having 6 to 16 carbon atoms having an unsaturated ring structure. As the unsaturated ring structure, benzene, toluene, xylene, furan, benzofuran, and the like can be exemplified. R 30 is more preferably independently an alkyl group having 1 to 12 carbon atoms which can have a branched chain or an alkoxy group having 1 to 12 carbon atoms which can have a branched chain. Note that, in each of the groups representing R 30 , a part or all of the hydrogen atoms can be substituted with a halogen atom, particularly a fluorine atom.

[0176] Compound (I) can be produced, for example, by the publicly known method described in U.S. Patent No. 5543086, U.S. Patent Application Publication No. 2014 / 0061505, and International Publication No. 2014 / 088063.

[0177] As the phthalocyanine pigment, for example, the phthalocyanine pigments described in Japanese Patent No. 5884953 and International Publication No. 2019 / 168090 can be exemplified.

[0178] As the cyanine pigment, a compound represented by the following formula (A1) or formula (A2) is preferable.

[0179]

[0180] In the formulae (Al) and (A2), the symbols are as described below.

[0181] R 101 ~R 109 and R 121 ~R 131 each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 15 carbon atoms which can have a substituent, an alkoxy group having 1 to 15 carbon atoms which can have a substituent, or an aryl group having 5 to 20 carbon atoms. R 110～114 and R 132～136 each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 15 carbon atoms or an alkoxy group having 1 to 15 carbon atoms.

[0182] X - represents a monovalent anion.

[0183] n1and n2each independently are 0 or 1. The hydrogen atoms bonded to the carbon ring containing -(CH2) n1 - and the carbon ring containing -(CH2) n2 - can be substituted with a halogen atom, an alkyl group having 1 to 15 carbon atoms which can have a substituent, or an aryl group having 5 to 20 carbon atoms which can have a substituent.

[0184] In the formula (Al), the formula (A2), R 102 ~R 105 , R 108 , R 109 , R 122 ~R 127 , R 130 and R 131 each independently preferably are 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, and more preferably a hydrogen atom from the viewpoint of obtaining high visible light transmittance.

[0185] In the formula (Al), the formula (A2), R 110 ~R 114 and R 132 ~R 136 each independently preferably are a hydrogen atom or an alkyl group having 1 to 15 carbon atoms, and more preferably a hydrogen atom from the viewpoint of obtaining high visible light transmittance.

[0186] R 106 , R 107 , R 128 and R 129each independently preferably is a hydrogen atom, an alkyl group having 1 to 15 carbon atoms, or an aryl group having 5 to 20 carbon atoms (may include a linear, cyclic, branched alkyl group), more preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms. In addition, R 106 and R 107 preferably are the same group, R 128 and R 129 preferably are the same group.

[0187] R 101 and R 121 preferably are an alkyl group having 1 to 15 carbon atoms or an aryl group having 5 to 20 carbon atoms, more preferably an alkyl group having 1 to 15 carbon atoms having a branched chain, from the viewpoint of maintaining the same high visible light transmittance in a transparent resin as in a solution.

[0188] As X - , can be mentioned: I - , BF4 - , PF6 - , CIO4 - , or an anion represented by formula (X1) or an anion represented by formula (X2), etc., preferably BF4 - or PF6 - .

[0189]

[0190] In the following description, the portion other than R 101 to R 114 in the pigment (A1) is also referred to as the skeleton (A1). The same applies to other pigments.

[0191] The compound in which nl is 1 in formula (A1) is shown in the following formula (Al l), and the compound in which nl is 0 in formula (A1) is shown in the following formula (A12).

[0192]

[0193] In formula (Al l) and formula (A12), R 101 to R 114 and X - are the same as in formula (A1). R 115 to R 120 each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 15 carbon atoms which can have a substituent, an alkoxy group having 1 to 15 carbon atoms which can have a substituent, or an aryl group having 5 to 20 carbon atoms. R 115 to R 120each independently preferably is a hydrogen atom, an alkyl group having 1 to 15 carbon atoms, or an aryl group having 5 to 20 carbon atoms (may include linear, cyclic, branched alkyl groups), and more preferably is a hydrogen atom or an alkyl group having 1 to 15 carbon atoms. In addition, R 115 ~R 120 are preferably the same group.

[0194] A compound in which n2 is 1 in formula (A2) is shown in the following formula (A21), and a compound in which n2 is 0 in formula (A2) is shown in the following formula (A22).

[0195]

[0196] In formula (A21) and formula (A22), R 121 ~R 136 and X - are the same as in formula (A2). R 137 ~R 142 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 15 carbon atoms which can have a substituent, an alkoxy group having 1 to 15 carbon atoms which can have a substituent, or an aryl group having 5 to 20 carbon atoms. R 137 ~R 142 each independently preferably is a hydrogen atom, an alkyl group having 1 to 15 carbon atoms, or an aryl group having 5 to 20 carbon atoms (may include linear, cyclic, branched alkyl groups), and more preferably is a hydrogen atom or an alkyl group having 1 to 15 carbon atoms. In addition, R 137 ~R 142 are preferably the same group.

[0197] Note that the pigment (A1), the pigment (A2) can be produced, for example, by using a publicly known method described in Dyes and pigments 73 (2007) 344-352 or J. Heterocyclic chem, 42, 959 (2005).

[0198] As for the content of the NIR pigment (A) in the substrate, it is preferable that the product of the total content of the pigment (U) and the pigment (A) as described above and the thickness of the resin film is within a specific range.

[0199] From the viewpoint of satisfying the above range, the content of the NIR pigment (A) in the resin film is preferably 5 parts by mass to 25 parts by mass, and more preferably 5 parts by mass to 20 parts by mass, with respect to 100 parts by mass of the resin.

[0200] <Substrate configuration>

[0201] The base material in the present filter can be a single layer structure or a multi-layer structure. In addition, the material of the base material is not particularly limited as long as it is a transparent material that transmits visible light of 400 nm to 700 nm, and can be an organic material or an inorganic material.

[0202] In the case where the base material is a single layer structure, a resin base material composed of a resin film containing a resin and a UV colorant (U) and a NIR colorant (A) is preferable.

[0203] In the case where the base material is a multi-layer structure, a structure in which a resin film containing a UV colorant (U) and a NIR colorant (A) is stacked on at least one main surface of a support is preferable. At this time, the support preferably contains a transparent resin or a transparent inorganic material.

[0204] As the resin, a transparent resin is preferable, and examples thereof include a polyester resin, an acrylic resin, an epoxy resin, an ene-thiol resin, a polycarbonate resin, a polyether resin, a polyarylate resin, a polysulfone resin, a polyethersulfone resin, a poly-p-phenylene resin, a polyarylene ether phosphine oxide resin, a polyamide resin, a polyimide resin, a polyamide-imide resin, a polyolefin resin, a cyclic olefin resin, a polyurethane resin, a polystyrene resin, and the like. These resins can be used alone or in combination of two or more. Among them, a polyimide resin is preferable from the viewpoints of excellent visible light transmittance and high glass transition temperature of the resin, and thus thermal degradation of the colorant is less likely to occur.

[0205] As the transparent inorganic material, a glass or a crystal material is preferable.

[0206] As the glass that can be used for the support, an absorption-type glass (near-infrared absorbing glass) containing a copper ion in a fluorophosphate glass or a phosphate glass, a soda-lime glass, a borosilicate glass, an alkali-free glass, a quartz glass, and the like can be exemplified. As the glass, an absorption-type glass is preferable depending on the purpose, and a phosphate glass, a fluorophosphate glass is preferable from the viewpoint of absorbing infrared light. When it is intended to absorb a large amount of red light (600 nm to 700 nm), an alkali glass, an alkali-free glass, a quartz glass is preferable. Note that the "phosphate glass" also includes a silicon phosphate glass in which a part of the glass framework is composed of SiO2.

[0207] As the glass, a chemically strengthened glass obtained by replacing alkali metal ions (for example, Li ions, Na ions) having a small ionic radius present on the main surface of a glass sheet with alkali metal ions (for example, Na ions or K ions for Li ions, K ions for Na ions) having a larger ionic radius at a temperature below the glass transition temperature can be used.

[0208] As the crystal material that can be used as the support, mention can be made of: quartz, lithium niobate, sapphire, and the like birefringent crystals.

[0209] As the support, from the viewpoint of shape stability related to long-term reliability of optical properties, mechanical properties, and the like, handleability at the time of filter production, and the like, an inorganic material is preferred, and glass, sapphire is particularly preferred.

[0210] The resin film can be formed by dissolving or dispersing the colorant (U) and the colorant (A), the resin or the raw material components of the resin, and each component as needed, in a solvent to prepare a coating liquid, coating the coating liquid on a support and drying it, and further curing it as needed. The above support can be the support contained in the present filter, or a peelable support used only at the time of forming the resin film. In addition, the solvent can be a dispersion medium capable of stable dispersion or a solvent capable of dissolution.

[0211] In addition, in order to improve voids caused by minute bubbles, depressions caused by the attachment of foreign matter, shrinkage holes in the drying step, and the like, the coating liquid can contain a surfactant. Furthermore, at the time of coating the coating liquid, for example, a dip coating method, a flow coating method, a spin coating method, or the like can be used. The above coating liquid is coated on a support, and then dried, thereby forming a resin film. In addition, in the case where the coating liquid contains raw material components of a transparent resin, further curing treatment such as heat curing, light curing, or the like is performed.

[0212] In addition, the resin film can also be made into a film shape by extrusion molding. In the case where the substrate is a single layer structure (resin substrate) composed of a resin film containing the colorant (U) and the colorant (A), the resin film can be directly used as the substrate. In the case where the substrate is a multilayer structure (composite substrate) having a support and a resin film containing the colorant (U) and the colorant (A) layered on at least one main surface of the support, the substrate can be manufactured by layering the film on the support and integrating it by heat pressure bonding or the like.

[0213] The resin film can have one layer, or two or more layers in the filter. In the case where the resin film has two or more layers, each layer can be of the same constitution, or of a different constitution.

[0214] The thickness of the resin film is preferably 10 μm or less, more preferably 5 μm or less.

[0215] In addition, in the case where the substrate is a single layer structure (resin substrate) composed of a resin film containing the colorant (U) and the colorant (A), the thickness of the resin film is preferably 10 μm or less, more preferably 5 μm or less.

[0216] When the substrate is a multilayer structure (composite substrate) having a support and a resin film containing pigment (U) and pigment (A), the thickness of the resin film is preferably 10 μm or less, more preferably 5 μm or less. When the resin film comprises multiple layers, the total thickness of each layer is preferably 20 μm or less, more preferably 10 μm or less.

[0217] There are no particular restrictions on the shape of the substrate; it can be in the form of a block, plate, or film.

[0218] Furthermore, from the viewpoint of warping or handling issues that may occur when reliability changes during the formation of a dielectric multilayer film, the thickness of the substrate is preferably 300 μm or less, more preferably 50 μm to 300 μm, and particularly preferably 70 μm to 300 μm.

[0219] Furthermore, when the substrate is a resin substrate containing resin and pigment, considering the advantage of reducing height, the thickness of the substrate is preferably 120 μm or less; from the viewpoint of reducing warping during the formation of multilayer films, the thickness of the substrate is preferably 50 μm or more. When the substrate is a composite substrate having a support and a resin film, the thickness of the substrate is preferably 70 μm to 110 μm.

[0220] <Dielectric Multilayer Film>

[0221] In this filter, a dielectric multilayer film is stacked on at least one main surface side of the substrate and serves as the outermost layer.

[0222] In this filter, at least one of the dielectric multilayer films is preferably designed as a near-infrared reflective layer (hereinafter also referred to as a NIR reflective layer). The other dielectric multilayer film is preferably designed as an NIR reflective layer, a reflective layer having a reflective region other than the near-infrared region, or an anti-reflective layer.

[0223] 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 near-infrared light except for the light-shielding area of ​​the resin film. It should be noted that the reflective area of ​​the NIR reflective layer may also include the light-shielding area of ​​the resin film in the near-infrared region. The NIR reflective layer may also be appropriately designed to block light in wavelength ranges other than the near-infrared region, such as near-ultraviolet light, in addition to its NIR reflective properties.

[0224] The NIR reflecting layer is composed of, for example, a dielectric multilayer film obtained by alternately laminating a low-refractive-index dielectric film (low-refractive-index film) and a high-refractive-index dielectric film (high-refractive-index film). The refractive index of the high-refractive-index film is preferably 1.6 or more, more preferably 2.2 to 2.5. As the material of the high-refractive-index film, for example, Ta2O5, TiO2, Nb2O5 can be listed. Among them, from the viewpoints of film formability, reproducibility, stability, and the like, TiO2 is preferred.

[0225] On the other hand, the refractive index of the low-refractive-index film is preferably less than 1.6, more preferably 1.45 or more and less than 1.55. As the material of the low-refractive-index film, for example, SiO2, SiO x N y Among them, from the viewpoints of film formability, reproducibility, stability, and the like, SiO2 is preferred.

[0226] Further, the transmittance of the NIR reflecting layer preferably steeply changes in the wavelength range at the boundary between the transmissive region and the light-blocking region. In order to achieve this, the total number of laminated layers of the dielectric multilayer film constituting the reflecting layer is preferably 15 layers or more, more preferably 25 layers or more, and further preferably 30 layers or more. However, when the total number of laminated layers is increased, warping or the like occurs or the film thickness increases, and thus the total number of laminated layers is preferably 100 layers or less, more preferably 75 layers or less, and further preferably 60 layers or less. In addition, the film thickness of the reflecting layer as a whole is preferably 2 μm to 10 μm.

[0227] If the total number of laminated layers and the film thickness of the dielectric multilayer film are within the above-described ranges, the NIR reflecting layer satisfies the requirements for miniaturization, and it is possible to suppress the angle-of-incidence dependence while maintaining high productivity. In addition, in the formation of the dielectric multilayer film, for example, a vacuum film formation process such as a CVD method, a sputtering method, a vacuum evaporation method, or the like; a wet film formation process such as a spray method, a dip method, or the like; or the like can be used.

[0228] The prescribed spectral characteristics can be imparted using one NIR reflecting layer (one set of dielectric multilayer film), or the prescribed spectral characteristics can be imparted using two or more NIR reflecting layers. In the case where two or more NIR reflecting layers are provided, each reflecting layer can have the same constitution or a different constitution. In the case where two or more reflecting layers are provided, the reflecting layers are usually composed of a plurality of reflecting layers that differ in the reflecting wavelength band. In the case where two reflecting layers are provided, one layer can be a near-infrared reflecting layer that blocks light in the short-wavelength band in the near-infrared region, and the other layer can be a near-infrared / near-ultraviolet reflecting layer that blocks light in both the long-wavelength band in the near-infrared region and the near-ultraviolet region.

[0229] As the antireflection layer, the following can be listed: dielectric multilayer film, intermediate refractive index medium, moth-eye structure in which the refractive index gradually changes, and the like. Among them, from the viewpoint of optical efficiency and productivity, the dielectric multilayer film is preferred. The antireflection layer is obtained by alternately laminating dielectric films as with the reflective layer.

[0230] The present optical filter can have, for example, a constituent element (layer) or the like that imparts absorption produced by inorganic fine particles or the like that control the transmission and absorption of light in a specific wavelength range as another constituent element. As specific examples of the inorganic fine particles, the following can be listed: ITO (indium tin oxide), ATO (antimony-doped tin oxide), cesium tungstate, lanthanum boride, and the like. ITO fine particles and cesium tungstate fine particles have high visible light transmittance and have light absorption properties in a wide range of infrared wavelength ranges of greater than 1200 nm, and thus can be used in cases where the blocking of such infrared light is required.

[0231] The present optical filter can provide, for example, an imaging device having excellent color reproducibility in the case of being used for a digital camera or the like. An imaging device that uses the present optical filter has a solid-state imaging element, an imaging lens, and the present optical filter. The present optical filter can be used, for example, in such a manner that it is disposed between the imaging lens and the solid-state imaging element or is directly attached to the solid-state imaging element, the imaging lens, or the like of the imaging device via an adhesive layer.

[0232] Examples

[0233] Next, the present application will be described more specifically by way of examples.

[0234] A UV-Vis spectrophotometer (manufactured by Hitachi High-Technologies Corporation, UH-4150) was used in the measurement of the spectral properties.

[0235] Note that the spectral properties in cases where the angle of incidence is not specifically described are values measured under the condition where the angle of incidence is 0 degrees (direction perpendicular to the main surface).

[0236] The pigments used in each example are described below.

[0237] Note that Compounds 1 to 17 are UV pigments, and Compound 18 is a NIR pigment.

[0238] Compound 1 (merocyanine compound): synthesized with reference to Japanese Patent No. 6504176.

[0239] Compound 2: Nikkafluor U1 manufactured by Nippon Shokubai Co., Ltd. was used.

[0240] Compound 3 (cyanine compound): SMP-416 manufactured by MITSUBISHI KASEI CORPORATION was used.

[0241] Compound 4 (cyanine compound): SMP-370 manufactured by Shin-Etsu Chemical Co., Ltd. was used.

[0242] Compound 5 (cyanine compound): SMP-471 manufactured by Shin-Etsu Chemical Co., Ltd. was used.

[0243] Compound 6: Kayalight 408 manufactured by Wako Pure Chemical Industries, Ltd. was used.

[0244] Compound 7: Kayalight B manufactured by Wako Pure Chemical Industries, Ltd. was used.

[0245] Compound 8: Nikkafluor MCT manufactured by Japan Chemical Industry Co., Ltd. was used.

[0246] Compound 9 (merocyanine compound): synthesized with reference to Japanese Patent No. 6504176.

[0247] Compound 10 (merocyanine compound): synthesized with reference to Japanese Patent No. 6504176.

[0248] Compound 11 (benzo azole compound): UVITEX OB manufactured by Tokyo Chemical Industry Co., Ltd. was used.

[0249] Compound 12 (merocyanine compound): synthesized with reference to Japanese Patent No. 6504176.

[0250] Compound 13 (merocyanine compound): synthesized with reference to Japanese Patent No. 6504176.

[0251] Compound 14 (azo compound): synthesized with reference to Japanese Patent No. 6256335.

[0252] Compound 15 (merocyanine compound): synthesized with reference to Japanese Patent No. 6504176.

[0253] Compound 16 (triazine compound): synthesized with reference to Japanese Patent No. 6256335.

[0254] Compound 17 (merocyanine compound): synthesized with reference to Japanese Patent No. 6504176.

[0255] Compound 18 (squarylium salt compound): synthesized with reference to Japanese Patent No. 6197940.

[0256]

[0257]

[0258] Test A: Spectral properties of UV pigments in dichloromethane

[0259] Each pigment was uniformly dissolved in dichloromethane. For each of the resulting solutions, the maximum absorption wavelength (λ max ), the absolute value of the difference between the wavelength at which the transmittance was 10% (UV10) and the wavelength at which the transmittance was 70% (UV70) in the range of wavelengths from 350 nm to 450 nm was measured using a spectrophotometer. The results are shown in the table below.

[0260] Table 5

[0261] Color max (nm in dichloromethane) ​ UV 70-UV 10 (nm) Compound 1 414 19 Compound 2 362 43 Compound 3 406 16 Compound 4 406 16 Compound 5 406 16 Compound 6 366 48 Compound 7 376 31 Compound 8 366 41 Compound 9 391 19 Compound 10 379 19 Compound 11 377 36 Compound 12 399 18 Compound 13 397 18 Compound 14 376 34 Compound 15 390 18 Compound 16 350 12 Compound 17 381 17

[0262] Test B: Spectral properties of UV pigments in resin

[0263] Example 1-1

[0264] The UV pigment of compound 1 (2.5 mass%), the NIR pigment of compound 18 (2.3 mass%), and a polyimide resin (polyimide varnish C-3G30G manufactured by Mitsubishi Gas Chemical Corporation) diluted with an organic solvent (a mixed solvent of γ-butyrolactone and cyclohexanone) were mixed, and the polyimide solution and the pigments were allowed to dissolve sufficiently.

[0265] The resulting resin solution was applied to a glass substrate (alkali glass, D263 manufactured by Schott) using spin coating, and heating was performed sufficiently to remove the organic solvent, thereby producing a pigment-containing polyimide film having a thickness of 5 μm.

[0266] For the resulting film, the transmittance spectrum at an incident direction of 0 degrees in the wavelength range from 350 nm to 1200 nm was measured using a spectrophotometer. The results are shown in the table below.

[0267] Examples 1-2 to 1-16

[0268] The kind of UV pigment, the amount of UV pigment added, the amount of NIR pigment added, and the thickness of the resin film were changed to the values described in the table below, and otherwise, a pigment-containing resin film was produced using the same method as in Example 1-1, and the transmittance spectrum was measured.

[0269] The results are shown in the table below.

[0270] Note that Examples 1-2, 1-5 to 1-11, 1-15, and 1-16 are examples, and Examples 1-1, 1-3, 1-4, and 1-12 to 1-14 are comparative examples.

[0271] T 440-480: Average transmittance (%) in the range of wavelengths 440 nm to 480 nm in the spectral transmittance curve

[0272] T 400-440 : Average transmittance (%) in the range of wavelengths 400 nm to 440 nm in the spectral transmittance curve

[0273] T 370-400 : Average transmittance (%) in the range of wavelengths 370 nm to 400 nm in the spectral transmittance curve

[0274] T 400 : Transmittance (%) at wavelength 400 nm in the spectral transmittance curve

[0275] T 390 : Transmittance (%) at wavelength 390 nm in the spectral transmittance curve

[0276] T 380 : Transmittance (%) at wavelength 380 nm in the spectral transmittance curve

[0277] T 370 : Transmittance (%) at wavelength 370 nm in the spectral transmittance curve

[0278]

[0279] According to the above results, in Example 1-2, Examples 1-5 to 1-11, Example 1-15, and Example 1-16 in which a UV colorant having a maximum absorption wavelength in the range of 360 nm to 395 nm in dichloromethane was used, the transmittance of blue light and the blocking of ultraviolet light were high, and excellent spectral characteristics were exhibited. In Example 1-16 in which two UV colorants were used in combination, the spectral characteristics were particularly excellent. Although Example 1-2 exhibited excellent spectral characteristics, it was necessary to increase the content of the UV colorant and the thickness of the resin film in order to obtain desired spectral characteristics.

[0280] [Example 2-1: Spectral characteristics of optical filter]

[0281] An ultraviolet and infrared cut-off multilayer film having a transmittance band in the range of 400 nm to 700 nm was formed on a glass substrate (alkali glass, D263 manufactured by SCHOTT). A resin thin film (absorbing film) identical to that of Example 1-1 was produced on the multilayer film by spin coating. Then, a dielectric multilayer film (antireflection film) composed of SiO2and TiO2was formed on the resin thin film by vapor deposition, thereby producing an absorbing-type infrared cut-off optical filter. For the obtained infrared cut-off optical filter, the transmittance spectrum in the wavelength range of 350 nm to 1200 nm was measured at an incident direction of 0 degrees and 50 degrees using a spectrophotometer. The results are shown in the table below.

[0282] <Example 2-2 to Example 2-15>

[0283] The kind of UV pigment, the added amount of UV pigment, the added amount of NIR pigment, the thickness of the resin film were changed to the values described in the following table, and otherwise, the infrared cut filter was produced in the same manner as in Example 2-1, and the transmission spectrum was measured.

[0284] The results are shown in the following table.

[0285] In addition, the spectral transmittance curve of the infrared cut filter of Example 2-14 is shown in FIG. 2-14, and the spectral transmittance curve of the infrared cut filter of Example 2-15 is shown in FIG. 2-15. Note that the solid line is the spectral transmittance curve at an incident direction of 0 degrees, and the broken line is the spectral transmittance curve at an incident direction of 50 degrees. Figure 5 Figure 6 In addition, the spectral transmittance curve of the infrared cut filter of Example 2-14 is shown in FIG. 2-14, and the spectral transmittance curve of the infrared cut filter of Example 2-15 is shown in FIG. 2-15. Note that the solid line is the spectral transmittance curve at an incident direction of 0 degrees, and the broken line is the spectral transmittance curve at an incident direction of 50 degrees.

[0286] Note that Example 2-5, Example 2-6, Example 2-9, Example 2-10, and Example 2-15 are examples, and Example 2-1 to Example 2-4, Example 2-7, Example 2-8, and Example 2-11 to Example 2-14 are comparative examples.

[0287] λ max : maximum absorption wavelength (nm)

[0288] T 440-480 : average transmittance (%) in the range of wavelength 440 nm to 480 nm in the spectral transmittance curve

[0289] T 400-440 : average transmittance (%) in the range of wavelength 400 nm to 440 nm in the spectral transmittance curve

[0290] T 370-400(0度) : average transmittance (%) in the range of wavelength 370 nm to 400 nm in the spectral transmittance curve at an incident angle of 0 degrees

[0291] T 370-400(50度) : average transmittance (%) in the range of wavelength 370 nm to 400 nm in the spectral transmittance curve at an incident angle of 50 degrees

[0292] UV10 (0度) : wavelength (nm) at which the transmittance is 10% in the range of wavelength 350 nm to 450 nm and at an incident angle of 0 degrees

[0293] UV10 (50度) : wavelength (nm) at which the transmittance is 10% in the range of wavelength 350 nm to 450 nm and at an incident angle of 50 degrees ​

[0294] UV20 (0度) : wavelength (nm) at which the transmittance is 20% in the wavelength range of 350 to 450 nm and under the condition that the incident angle is 0 degree

[0295] UV20 (50度) : wavelength (nm) at which the transmittance is 20% in the wavelength range of 350 to 450 nm and under the condition that the incident angle is 50 degrees

[0296] UV50 (0度) : wavelength (nm) at which the transmittance is 50% in the wavelength range of 350 to 450 nm and under the condition that the incident angle is 0 degree

[0297] UV50 (50度) : wavelength (nm) at which the transmittance is 50% in the wavelength range of 350 to 450 nm and under the condition that the incident angle is 50 degrees

[0298] UV70 (0度) : wavelength (nm) at which the transmittance is 70% in the wavelength range of 350 to 450 nm and under the condition that the incident angle is 0 degree

[0299] | UV70 (0度) - UV10 (0度) | : UV10 (0度) - UV70 (0度) | : absolute value (nm) of the difference between UV10 and UV70

[0300] | UV10 (50度) - UV10 (0度) | : UV10 (0度) - UV10 (50度) | : absolute value (nm) of the difference between UV10 and UV10

[0301] | UV20 (50度) - UV20 (0度) | : UV20 (0度) - UV20 (50度) | : absolute value (nm) of the difference between UV20 and UV20

[0302] | UV50 (50度) - UV50 (0度) | : UV50 (0度) - UV50 (50度) | : absolute value (nm) of the difference between UV50 and UV50

[0303]

[0304] According to the above results, the optical filters of Examples 2-5, 2-6, 2-9, 2-10 and 2-15, which used UV pigments having a maximum absorption wavelength in the range of 360 nm to 395 nm in dichloromethane, and a spectrum (UV70-UV10) in the solution of Test A and a spectrum in the resin of Test B within the prescribed range, had high transmittance of blue light, and in addition, had high blocking of ultraviolet light even at high angles of incidence, showing excellent spectral characteristics. In Example 2-15, in which two kinds of UV pigments were used in combination, the spectral characteristics were particularly excellent.

[0305] On the other hand, the optical filters of Examples 2-1, 2-3, 2-4, 2-12, 2-13 and 2-14, which did not satisfy the range of the maximum absorption wavelength, and the optical filters of Examples 2-2, 2-7, 2-8 and 2-11, in which the spectrum in the solution of Test A was not within the prescribed range, resulted in low transmittance of blue light or blocking of ultraviolet light at high angles of incidence.

[0306] <Example 3-1: Light Resistance Evaluation>

[0307] The UV pigment of Compound 1 (7.5 mass%), the UV pigment of Compound 13 (3.5 mass%), the NIR pigment of Compound 18 (7 mass%) and a polyimide resin (polyimide varnish C-3G30G manufactured by Mitsubishi Gas Chemical Corporation) diluted with an organic solvent (a mixed solvent of γ-butyrolactone and cyclohexanone) were mixed, and the polyimide solution and the pigments were sufficiently dissolved. The added amount of the pigments indicates the added amount with respect to the resin.

[0308] The resulting solution was coated on a glass substrate (alkali glass, D263 manufactured by SCHOTT) by spin coating, and heating was sufficiently performed to remove the organic solvent, thereby producing a polyimide film containing pigments having a thickness of 1.5 μm.

[0309] The same antireflection film as in Example 2-1 was formed on the resulting polyimide film by vapor deposition. A light resistance test was performed on the resulting optical sample using a super xenon weather-ometer manufactured by Shukuba Test Machine Corporation. Note that the incident surface was set to the antireflection film surface.

[0310] The light amount was set to 80000 J / mm2in the wavelength band of 300 nm to 2450 nm in terms of cumulative light amount. 2 The residual rate of the NIR pigment was calculated from the absorbance coefficients at 400 nm and 680 nm before and after the light resistance test. The results are shown in the table below.

[0311] Note that if the residual rate at 400 nm (T400nm residual rate) is 85% or more and the residual rate at 680 nm (T680nm residual rate) is 75% or more, the light resistance is considered to be excellent.

[0312] Examples 3-2 to 3-10: Evaluation of light resistance

[0313] The kind and content of the pigment were changed to the values described in the table below, and otherwise, the light resistance test was performed in the same manner as in Example 3-1.

[0314] The results are shown in the table below.

[0315] Note that Examples 3-1 to 3-4, 3-5, 3-7 to 3-10 are examples, and Example 3-6 is a comparative example.

[0316]

[0317] From the above results, it is known from the comparison of Example 3-6 with Examples 3-4 to 3-5 that when UV pigments and NIR pigments coexist, there is a tendency for the NIR pigments to deteriorate. Here, it is known that by using a plurality of merocyanine compounds as UV pigments in combination as shown in Examples 3-1 to 3-3, it is possible to suppress the deterioration of the NIR pigments.

[0318] The present application has been described in detail and with reference to specific embodiments, but it will be apparent to one skilled in the art that various changes or modifications can be made without departing from the spirit and scope of the present application. This application is based on Japanese Patent Application (Japanese Patent Application No. 2020-126700) filed on July 27, 2020, the contents of which are incorporated herein by reference.

[0319] Industrial applicability

[0320] The filter of the present application has good ultraviolet light blocking properties in which the ultraviolet light blocking property, particularly the decrease in the ultraviolet light blocking property at high angles of incidence, is suppressed while maintaining good near-infrared light blocking properties and visible light transmittance, particularly blue light transmittance. It is useful in uses such as information acquisition devices such as cameras for conveyors, sensors, and the like, in which high performance has been advancing in recent years.

[0321] Explanation of reference numerals

[0322] 1A, 1B, 1C, 1D... filter, 10... base material, 11... support, 12... resin film, 30... dielectric multilayer film

Claims

1. A filter having a substrate and a dielectric multilayer film laminated on at least one main surface side of the substrate as the outermost layer, wherein, The substrate has a resin film comprising pigment (U), pigment (A), and resin. Pigment (U) has a maximum absorption wavelength in dichloromethane in the range of 360 nm to 395 nm, and pigment (A) has a maximum absorption wavelength in dichloromethane in the range of 600 nm to 800 nm. The filter satisfies all of the following spectral characteristics (i-1) to (i-5): (i-1) Average transmittance T in the wavelength range of 440 nm to 480 nm in the spectral transmittance curve 440-480 It is over 86%; (i-2) The wavelength within the range of 350nm to 450nm, and under the condition of an incident angle of 0 degrees and a transmittance of 10%, is set as UV10. (0 The wavelength at which the transmittance is 20% is set to UV20. (0 The wavelength at which the transmittance is 50% is set to UV50. (0 (degree), and The wavelength within the range of 350nm to 450nm, with an incident angle of 50 degrees and a transmittance of 10%, is set as UV10. (50 The wavelength at which the transmittance is 20% is set to UV20. (50 The wavelength at which the transmittance is 50% is set to UV50. (50 Spend), at this time, UV10 (0 (degree) and UV10 (50 The absolute value of the difference (degree) is less than 3nm. UV20 (0 (degree) and UV20 (50 The absolute value of the difference (degree) is less than 4nm. UV50 (0 (degree) and UV50 (50 The absolute value of the difference (degree) is less than 3nm; (i-3) Average transmittance T in the wavelength range of 400 nm to 440 nm in the spectral transmittance curve 400-440 It is over 40%; (i-4) Average transmittance T in the wavelength range of 370 nm to 400 nm in the spectral transmittance curve under the condition of 0 degrees of incident angle. 370-400(0度) Less than 1%; (i-5) Average transmittance T in the wavelength range of 370 nm to 400 nm in the spectral transmittance curve under the condition of an incident angle of 50 degrees. 370-400(50度) It is below 0.5%.

2. The filter as described in claim 1, wherein, The filter also satisfies the following spectral characteristics (i-6): (i-6) The wavelength within the range of 350nm to 450nm, and under the condition of an incident angle of 0 degrees and a transmittance of 10%, is set to UV10. (0 The wavelength at which the transmittance is 70% is set to UV70. (0 (degree) UV10 (0 (degree) and UV70 (0 The absolute value of the difference (degree) is less than 16nm.

3. The filter as described in claim 1 or 2, wherein, For the pigment (U), in the spectral transmittance curve of the coating film obtained by dissolving the pigment (U) in the resin and coating it onto an alkaline glass plate, all of the following spectral characteristics (ii-1) to (ii-6) are satisfied: (ii-1) Average transmittance T in the wavelength range of 400 nm to 440 nm 400-440 It is over 40%; (ii-2) Average transmittance T in the wavelength range of 370 nm to 400 nm 370-400 Less than 5%; (ii-3) Transmittance T at a wavelength of 400 nm 400 Below 7%; (ii-4) Transmittance T at a wavelength of 390 nm 390 Less than 5%; (ii-5) Transmittance T at a wavelength of 380 nm 380 Less than 5%; (ii-6) Transmittance T at a wavelength of 370 nm 370 It is below 5%.

4. The filter as described in claim 1 or 2, wherein, The pigment (U) satisfies the following spectral characteristics (iii-1): (iii-1) In the spectral transmittance curve measured by dissolving the pigment (U) in dichloromethane in such a way that the transmittance at the maximum absorption wavelength is 10%, the wavelength at which the transmittance is 10% in the wavelength range of 350 nm to 450 nm is set as UV10, and the wavelength at which the transmittance is 70% is set as UV70. at this time, The absolute value of the difference between UV10 and UV70 is less than 25nm.

5. The filter as described in claim 1 or 2, wherein, The thickness of the resin film is less than 10 μm, and the product of the total content of the pigment (U) and the pigment (A) in the resin film and the thickness of the resin film is less than 100 (mass %·μm).

6. The filter as described in claim 1 or 2, wherein, The pigment (U) is a pigment (U1) that has the maximum absorption wavelength in dichloromethane in the range of 370 nm to 385 nm. The resin film also contains a pigment (U2), which has a maximum absorption wavelength in dichloromethane in the range of 385 nm to 405 nm. The absolute value of the difference between the maximum absorption wavelength of pigment (U1) in the resin and the maximum absorption wavelength of pigment (U2) in the resin is 10 nm or more and 15 nm or less.

7. The filter as described in claim 1 or 2, wherein, The filter also satisfies all of the following spectral characteristics (i-4-1) to (i-6-1): (i-4-1) The average transmittance T 370-400(0度) Less than 0.5%; (i-5-1) The average transmittance T 370-400(50度) Less than 0.1%; (i-6-1) The wavelength is set to UV10 within the wavelength range of 350nm to 450nm, under the condition of an incident angle of 0 degrees and a transmittance of 10%. (0 The wavelength at which the transmittance is 70% is set to UV70. (0 (degree) UV10 (0 (degree) and UV70 (0 The absolute value of the difference (degree) is less than 14nm.

8. The filter as described in claim 1 or 2, wherein, The pigment (U) includes anthocyanin.

9. The filter as claimed in claim 8, wherein, The anthocyanin mentioned is a compound represented by the following formula (M). The symbols in equation (M) are as follows: R 1 This indicates a monovalent hydrocarbon group with 1 to 12 carbon atoms that can have substituents; R 2 ~R 5 Each can independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms; Y indicates that R 6 and R 7 Substituted methylene or oxygen atom; R 6 and R 7 Each can independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms; X represents any one of the divalent groups represented by the following formulas (X1) to (X5), where R 8 and R 9 Each can independently represent a monovalent hydrocarbon group with 1 to 12 carbon atoms that can have substituents, R 10 ~R 19 Each can independently represent a hydrogen atom or a monovalent hydrocarbon group with 1 to 12 carbon atoms that may have substituents.

10. The filter as claimed in claim 1 or 2, wherein, The pigment (A) comprises a compound selected from squaric acid. At least one of the following pigments: salt pigment, phthalocyanine pigment, and anthocyanin pigment.

11. The filter as claimed in claim 1 or 2, wherein, The pigment (A) comprises squaric acid containing a compound represented by formula (I). Salt pigment, The symbols in equation (I) are as follows: R 24 and R 26 Each of these can be independently represented by a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group with 1 to 6 carbon atoms, an alkoxy group with 1 to 6 carbon atoms, an acyloxy group with 1 to 10 carbon atoms, or -NR. 27 R 28 Or a group represented by the following formula (S), 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 -NHR 30 or -SO2-R 30 R 29 R is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms that may have substituents, an aryl group having 6 to 11 carbon atoms that may have substituents, or an aralkyl group having 7 to 18 carbon atoms that may have substituents and may have oxygen atoms between carbon atoms. 30 Each of the carbon atoms can be replaced by one or more hydrogen atoms, which may be substituted with halogen atoms, hydroxyl groups, carboxyl groups, sulfonyl groups, or cyano groups, and may contain unsaturated bonds, oxygen atoms, or 1 to 25 hydrocarbon groups with saturated or unsaturated ring structures between carbon atoms. 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. R 21 and R 22 R 22 and R 25 and R 21 and R 23 They can connect with each other and, together with nitrogen atoms, form 5-membered or 6-membered heterocycles A, B, and C, respectively. As R in the case of forming heterocyclic A 21 and R 22 The bonded divalent group -Q- indicates that the hydrogen atom can be replaced by an alkyl group with 1 to 6 carbon atoms, an aryl group with 6 to 10 carbon atoms, or an alkylene group or alkyleneoxy group with 1 to 10 carbon atoms that has a substituent. 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 divalent group X formed by bonding 2 -Y 2 - where 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 represented by any one 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, in which case oxygen atoms can exist between carbon atoms. 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, an alkoxy group with 1 to 6 carbon atoms, or -NR. 38 R 39 R 38 and R 39 Each independently represents an alkyl group having 1 to 20 hydrogen atoms or carbon atoms, R 31 ~R 36 Each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 10 carbon atoms, R 37 This indicates an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms. R 27 R 28 R 29 R 31 ~R 37 R without the formation of heterocycles 21 ~R 23 and R 25 Each can bond with any of the others to form a 5-membered ring or a 6-membered ring, R 31 and R 36 Direct bonding is possible, R 31 and R 37 They can be bonded directly. R without the formation of heterocycles 21 and R 22 Each can independently represent a hydrogen atom, an alkyl group with 1 to 6 carbon atoms that may have substituents, an allyl group that may have substituents, or an aryl group with 6 to 11 carbon atoms that may have substituents, or an aralkyl group with 6 to 11 carbon atoms that may have substituents, and R in the case of not forming a heterocycle. 23 and R 25 Each can be independently represented by a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms.

12. The filter as claimed in claim 1 or 2, wherein, The resin is a transparent resin.

13. The filter as claimed in claim 12, wherein, The filter contains polyimide resin as the transparent resin.

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