Optical absorbing composition

Abstract

To provide an optical absorbing composition which is advantageous in view of absorption characteristics in a short wavelength region.SOLUTION: A light-absorbing composition according to the present invention contains a phosphonic acid, an ultraviolet absorber having a hydroxyl group and a carbonyl group within molecules, and a metal component.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a light-absorbing composition, a light-absorbing film, and an optical filter.

Background Art

[0002] In an imaging device using a solid-state imaging device such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor )), various optical filters are arranged in front of the solid-state imaging device in order to obtain an image having good color reproducibility. Generally, a solid-state imaging device has spectral sensitivity in a wide wavelength range from the ultraviolet region to the infrared region. On the other hand, human visual sensitivity exists only in the visible light region. For this reason, in order to make the spectral sensitivity of the solid-state imaging device in the imaging device closer to human visual sensitivity, a technique of arranging an optical filter that shields part of infrared or ultraviolet light in front of the solid-state imaging device is known.

[0003] Conventionally, as such an optical filter, those that shield infrared or ultraviolet light by utilizing light reflection by a dielectric multilayer film have been common. On the other hand, in recent years, an optical filter including a film containing a light absorber has attracted attention. Since the transmittance characteristics of an optical filter including a film containing a light absorber are less affected by the incident angle, a good image with little change in color tone can be obtained even when light is incident obliquely on the optical filter in an imaging device. In addition, a light absorption type optical filter that does not use a light reflection film can suppress the generation of ghosts and flares caused by multiple reflections by the light reflection film, so it is easy to obtain a good image in backlight conditions or night scene photography. In addition, an optical filter including a film containing a light absorber is also advantageous in terms of miniaturization and thinning of the imaging device.

[0004] As such a light absorber, a light absorber formed by a phosphonic acid and copper ions is known. For example, Patent Document 1 describes an optical filter including a light absorption layer containing a light absorber formed by a phosphonic acid having a phenyl group or a halogenated phenyl group (phenyl-based phosphonic acid) and copper ions.

[0005] Further, Patent Document 2 describes an optical filter including a UV-IR absorption layer capable of absorbing infrared rays and ultraviolet rays. The UV-IR absorption layer contains a UV-IR absorber formed by a phosphonic acid and copper ions. In order for the optical filter to satisfy predetermined optical characteristics, the UV-IR absorbent composition contains, for example, a phenyl-based phosphonic acid and a phosphonic acid having an alkyl group or a halogenated alkyl group (alkyl-based phosphonic acid).

[0006] Further, Patent Document 3 describes an infrared cut filter including an organic dye-containing layer containing a predetermined organic dye and a copper phosphonate-containing layer.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0008] The techniques described in Patent Documents 1 to 3 have room for reconsideration from the viewpoint of the absorption characteristics in the short wavelength region near 400 nm. Therefore, the present invention provides a light-absorbing composition, a light-absorbing film, and an optical filter that are advantageous from the viewpoint of the absorption characteristics in the short wavelength region.

Means for Solving the Problems

[0009] The present invention relates to a phosphonic acid, an ultraviolet absorber having a hydroxy group and a carbonyl group in the molecule, and a metal component, and contains a light-absorbing composition.

[0010] Further, the present invention relates to a phosphonic acid, an ultraviolet absorber having a hydroxy group and a carbonyl group in the molecule, and a metal component, and contains a light-absorbing film.

[0011] Further, the present invention provides an optical filter including the above light-absorbing film.

Advantages of the Invention

[0012] The above light-absorbing composition is advantageous from the viewpoint of absorption characteristics in the short wavelength region. In addition, the above light-absorbing film and the above optical filter are advantageous from the viewpoint of absorption characteristics in the short wavelength region.

Brief Description of the Drawings

[0013]

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[0014] In an optical filter for an imaging device using a solid-state imaging device, in addition to absorbing light in a long wavelength region such as infrared light, if it is possible to effectively absorb light in a short wavelength region near a wavelength of 400 nm, the value of the optical filter will be further enhanced. According to the optical filter described in Patent Document 1, the wavelength at which the spectral transmittance becomes 50% at wavelengths of 350 nm to 450 nm is 400 It is less than nm. In addition, according to the optical filter described in Patent Document 2, the wavelength at which the spectral transmittance becomes 50% at wavelengths from 350 nm to 450 nm is in the range of approximately 390 nm to 415 nm. Based on these facts, it is difficult to say that the optical filters described in Patent Documents 1 and 2 are advantageous from the viewpoint of effectively absorbing light in the short-wavelength region near 400 nm. The infrared cut filter described in Patent Document 3 requires a plurality of light absorption layers, namely an organic dye-containing layer and a copper phosphonate-containing layer. Therefore, it is difficult to say that the technology described in Patent Document 3 is advantageous from the viewpoint of simplifying the optical filter.

[0015] Therefore, the present inventors have intensively studied to develop a light-absorbing composition that contains a phosphonic acid and a metal component and is advantageous from the viewpoint of effectively absorbing light in the short-wavelength region near 400 nm. As a result of repeated extensive trial and error, the present inventors have newly found that a light-absorbing composition containing a predetermined ultraviolet absorber together with a phosphonic acid and a metal component is advantageous from the viewpoint of effectively absorbing light in the short-wavelength region, and have completed the present invention.

[0016] Hereinafter, embodiments of the present invention will be described. Note that the following description relates to examples of the present invention, and the present invention is not limited to the following embodiments.

[0017] The light-absorbing composition according to the present invention contains a phosphonic acid, an ultraviolet absorber having a hydroxy group and a carbonyl group in the molecule, and a metal component. Since the light-absorbing composition contains an ultraviolet absorber having a hydroxy group and a carbonyl group in the molecule together with a phosphonic acid and a metal component, a light-absorbing film or an optical filter produced using the light-absorbing composition is likely to effectively absorb light in the wavelength region near 400 nm.

[0018] For ultraviolet absorbers, advantageous conditions include appropriate light absorption and transmission ranges, being photochemically stable, having a low enough photosensitizing effect within the range of use, being thermochemically stable, and so on. From such a perspective, as a mechanism of light absorption by ultraviolet absorbers, it is conceivable to utilize the intramolecular hydrogen transfer reaction (intramolecular hydrogen abstraction reaction) of the hydroxy group by photoexcitation. Examples of ultraviolet absorbers that exhibit such a mechanism include compounds such as hydroxybenzophenone, salicylic acid, hydroxyphenylbenzotriazole, hydroxyphenyltriazine, and substituted acrylonitrile. In hydroxybenzophenone and salicylic acid, the reaction related to hydrogen transfer between the hydroxy group and the carbonyl group contained in the molecule is involved in light absorption such as ultraviolet light. On the other hand, in hydroxyphenylbenzotriazole, hydroxyphenyltriazine, and substituted acrylonitrile, the reaction related to hydrogen transfer between the hydroxy group and the nitrogen atom contained in the molecule is involved in light absorption such as ultraviolet light. Since these ultraviolet absorbers have a hydroxy group in their molecules, it is presumed that they will cause interactions such as partial complexation with coexisting metal components or hydrogen donors. In systems such as light-absorbing compositions containing ultraviolet absorbers and their cured products, a comparison is made between the case where the ultraviolet absorber having a hydroxy group exists alone and the case where a metal component or hydrogen donor coexists with the ultraviolet absorber having a hydroxy group. According to this comparison, differences occur in optical properties such as their light absorption spectra and their light transmission spectra, thus supporting the above presumption. In particular, in a light-absorbing film obtained by curing a light-absorbing composition containing phosphonic acid, an ultraviolet absorber having a hydroxy group and a carbonyl group in the molecule, and a metal component, it has been found that a phenomenon occurs in which the light absorption band at wavelengths of 300 to 500 nm shifts to the long-wavelength side. Therefore, such a light-absorbing film is advantageous for effectively and appropriately absorbing light near a wavelength of 400 nm. When the light absorption band shifts or expands to the long-wavelength side, for example, a phenomenon may occur in which the absorption maximum wavelength shifts to the long-wavelength side within the wavelength range of 300 nm to 500 nm of the transmission spectrum, or a phenomenon may occur in which the wavelength at which the transmittance becomes 50% (UV cut-off wavelength) shifts to the long-wavelength side may become apparent.Thus, according to the light-absorbing composition, the cured product thereof which is a light-absorbing film, and the optical filter provided with the light-absorbing film according to the present invention, the absorption characteristics inherent in the ultraviolet absorber are short-wave. It is adjusted so as to be able to effectively absorb light in the long wavelength region. As a result, when the spectral transmittance of such a light-absorbing film or optical filter is used together with a solid-state imaging device or the like, it tends to be more appropriate.

[0019] The arrangement of the hydroxy group and the carbonyl group in the ultraviolet absorber is not limited to a specific arrangement. In the ultraviolet absorber, desirably, the hydroxy group and the carbonyl group are arranged with 1 to 6 atoms therebetween. Thereby, in the ultraviolet absorber, it is considered that hydrogen transfer easily occurs between the hydroxy group and the carbonyl group. For this reason, a phenomenon in which the light absorption band at a wavelength of 300 to 500 nm shifts to the long wavelength side effectively occurs easily. As a result, the light-absorbing film obtained by curing the light-absorbing composition is more likely to effectively and appropriately absorb light near a wavelength of 400 nm.

[0020] In the transmission spectrum at an incident angle of 0 degrees of the light-absorbing film obtained by curing the light-absorbing composition according to the present invention, the transmittance T at a wavelength of 400 nm 400 , the transmittance T at a wavelength of 550 nm , and the transmittance T at a wavelength of 800 nm 550 satisfy, for example, the conditions of 8 ≤ T 800 / T 550 and 8 ≤ T 400 / T 550 / T 800 . Thereby, the light-absorbing film or optical filter produced using the light-absorbing composition is likely to appropriately absorb ultraviolet rays and infrared rays in the wavelength region around the visible region, while exhibiting a high transmittance with respect to visible light.

[0021] The transmittance T 400 , the transmittance T 550 , and the transmittance T 800 preferably satisfy 12 ≤ T 550 / T 400 and 28 ≤ T 550 / T800 satisfies the condition, more desirably 16 ≦ T 550 / T 400 and 60 ≦ T 550 / T 800 and satisfies the condition.

[0022] The ultraviolet absorber is not limited to a specific ultraviolet absorber as long as it has a hydroxy group and a carbonyl group in its molecule. The ultraviolet absorber is desirably a compound that is less likely to aggregate even when mixed with a phosphonic acid and a metal component. Such an ultraviolet absorber contains, for example, at least hydroxybenzophenone.

[0023] The ultraviolet absorber desirably contains a benzophenone compound represented by the following formula (A1). In this case, the light absorption film or optical filter produced using the light absorption composition is more reliably likely to effectively absorb light in the short wavelength region near a wavelength of 400 nm.

[0024]

Chemical formula

[0025] In formula (A1), R 11 , R 12 , R 21 , and R 22 at least one of which is a hydroxy group. In formula (A1), when R 11 , R 12 , R 21 , or R 22 is a functional group other than a hydroxy group, a plurality of R 11 , a plurality of R 12 , a plurality of R 21 , or a plurality of R 22 may be present, and at least one of R 11 , R 12 , R 21 , and R 22 may not be present.

[0026] R 11 , R 12 , R 21 , or R 22When the functional group is other than a hydroxy group, the functional group may be, for example, a carboxyl group, an aldehyde group, a halogen, an alkyl group having 1 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms in which one or more hydrogen atoms are substituted by halogen atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms in which one or more hydrogen atoms are substituted by halogen atoms.

[0027] The ultraviolet absorber preferably contains a benzophenone compound represented by the following formula (A2). In this case, the light absorption film or optical filter produced using the light absorption composition can more reliably and easily absorb light in the short wavelength region near 400 nm.

[0028]

Chemical formula

[0029] In formula (A2), R 31 may be a hydroxy group, a carboxyl group, an aldehyde group, a halogen, an alkyl group having 1 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms in which one or more hydrogen atoms are substituted by halogen atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms in which one or more hydrogen atoms are substituted by halogen atoms. In formula (A2), R 31 may not be present. In formula (A2), R 41 and R 42 may be a hydroxy group, a carboxyl group, an aldehyde group, a halogen, an alkyl group having 1 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms in which one or more hydrogen atoms are substituted by halogen atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms in which one or more hydrogen atoms are substituted by halogen atoms. In formula (A2), R 41 and R 42 may not be present. In formula (A2), a plurality of R 41 may be present, and a plurality of R42 may also be present.

[0030] The benzophenone compound represented by formula (A1) or formula (A2) is not limited to a specific compound. The benzophenone compound is, for example, at least one selected from the group consisting of 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-4'-chlorobenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-n-octoxybenzophenone, 2-hydroxy-5-chlorobenzophenone, and 2,4-dibenzoylresorcinol.

[0031] The phosphonic acid is not limited to a specific phosphonic acid. The light-absorbing composition may contain a single type of phosphonic acid or may contain a plurality of types of phosphonic acids. The phosphonic acid is represented by, for example, the following formula (B). In this case, the light-absorbing film or optical filter produced using the light-absorbing composition effectively absorbs light in a wavelength region longer than 750 nm and is more likely to effectively absorb light in a short wavelength region near 400 nm.

[0032]

Chemical formula

[0033] In formula (B), R 3 is an alkyl group, a halogenated alkyl group in which at least one hydrogen atom in the alkyl group is substituted with a halogen atom, an aryl group, or a halogenated aryl group in which at least one hydrogen atom in the aryl group is substituted with a halogen atom.

[0034] The phosphonic acid represented by formula (B) is not limited to a specific phosphonic acid. The phosphonic acid represented by formula (B) may be a phosphonic acid such as methylphosphonic acid, ethylphosphonic acid, normal (n-)propylphosphonic acid, isopropylphosphonic acid, normal (n-)butylphosphonic acid, isobutylphosphonic acid, sec-butylphosphonic acid, tert-butylphosphonic acid, and phenylphosphonic acid, or may be one in which at least one hydrogen atom in the above phosphonic acid is substituted with a halogen atom, such as bromomethylphosphonic acid, fluoroethylphosphonic acid, bromophenylphosphonic acid, and iodophenylphosphonic acid.

[0035] The metal component is not limited to a specific metal component. The metal component is, for example, a copper component. In this case, the light absorption film or optical filter produced using the light-absorbing composition is more likely to effectively absorb light in the short wavelength region near 400 nm. In the light-absorbing composition, the metal component may exist as metal ions or may exist in a state of forming a complex with a predetermined compound. The source of the metal component is not limited to a specific compound. The source of the metal component is, for example, acetate, benzoate, formate, stearate, pyrophosphate, oxide, chloride, hydroxide, or hydrated salts thereof.

[0036] In the light-absorbing composition, the ratio of the content of the ultraviolet absorber to the content of the metal component is not limited to a specific value. The ratio is, for example, 0.001 to 0.100 on a molar basis, preferably 0.001 to 0.030. Thereby, the light absorption film or optical filter produced using the light-absorbing composition is more likely to effectively absorb light in the short wavelength region near 400 nm.

[0037] In the light-absorbing composition, the ratio of the content of the ultraviolet absorber to the content of the phosphonic acid is not limited to a specific value. The ratio is, for example, 0.1% to 5% on a mass basis, desirably 0.1% to 3%, and more desirably 0.1% to 1%. Thereby, the light-absorbing film or optical filter produced using the light-absorbing composition can more reliably and effectively absorb light in the short-wavelength region near a wavelength of 400 nm.

[0038] In the light-absorbing composition, in addition to the reaction between the phosphonic acid and the metal component, particulate light absorbers may be formed by the reaction of any of the phosphonic acid, the metal component, and the ultraviolet absorber. For example, a phosphonic acid-copper compound formed from the reaction between the phosphonic acid and the copper component is an infrared absorber. The average particle diameter of the particulate light absorbers is, for example, 5 nm to 200 nm. If the average particle diameter of the fine particles is 5 nm or more, no special process is required for miniaturization of the fine particles, and the structure of the fine particles containing at least the light absorber is less likely to be broken. Also, the fine particles are well dispersed in the light-absorbing composition. Further, when the average particle diameter of the fine particles is 200 nm or less, the influence of Mie scattering can be reduced, the transmittance of visible light in the light-absorbing film can be improved, and deterioration of characteristics such as contrast and haze of an image captured by an imaging device can be suppressed. The average particle diameter of the fine particles is desirably 100 nm or less. In this case, since the influence of Rayleigh scattering is reduced, the transparency with respect to visible light is enhanced in the light-absorbing film formed using the light-absorbing composition. Also, the average particle diameter of the fine particles is more desirably 75 nm or less. In this case, the transparency with respect to visible light of the light-absorbing film produced using the light-absorbing composition is particularly high. Incidentally, the average particle diameter of the fine particles can be measured by the dynamic light scattering method.

[0039] The light-absorbing composition may further contain, for example, a phosphate ester. The phosphate ester Due to the action of tellurium, the light absorber is likely to be properly dispersed in the light-absorbing composition or the cured light-absorbing film. In addition to its function as a dispersant, a part of the phosphate ester may react with the metal component to form a compound. Further, the phosphate ester may further coordinate or react with the compound formed by the metal component and phosphonic acid to form a compound. These compounds or the components of these copper salts may be included in the light absorber.

[0040] The phosphate ester is, for example, a phosphate ester having a polyoxyalkyl group. The phosphate ester having a polyoxyalkyl group is not limited to a specific phosphate ester. The phosphate ester having a polyoxyalkyl group is, for example, Prysurf A208N: polyoxyethylene alkyl (C12, C13) ether phosphate ester, Prysurf A208F: polyoxyethylene alkyl (C8) ether phosphate ester, Prysurf A208B: polyoxyethylene lauryl ether phosphate ester, Prysurf A219B: polyoxyethylene lauryl ether phosphate ester, Prysurf AL: polyoxyethylene styrenated phenyl ether phosphate ester, Prysurf A212C: polyoxyethylene tridecyl ether phosphate ester, or Prysurf A215C: polyoxyethylene tridecyl ether phosphate ester. These are all products manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. In addition, the phosphate ester may be, for example, NIKKOL DDP-2: polyoxyethylene alkyl ether phosphate ester, NIKKOL DDP-4: polyoxyethylene alkyl ether phosphate ester, or NIKKOL DDP-6: polyoxyethylene alkyl ether phosphate ester. These are all products manufactured by Nikko Chemicals Co., Ltd. In the light-absorbing composition, the mass ratio of the content of phosphonic acid to the content of the phosphate ester is 0.2 to 10.0, preferably 0.3 to 8.0.

[0041] The light-absorbing composition may further contain a resin. The resin is preferably a transparent resin that exhibits a high transmittance at least in the visible light range. For example, but not limited to these, acrylic resins, epoxy resins, polycarbonate resins, polyether resins, polyester resins, cyclic olefin resins, and silicone resins, etc. are used as the resin.

[0042] The resin is preferably a silicone resin containing an aryl group such as a phenyl group. When the resin contained in the light-absorbing film is hard (rigid), as the thickness of the layer containing the resin increases, cracks are likely to occur due to curing shrinkage during the production of the light-absorbing film. When the resin is a silicone resin containing an aryl group, the light-absorbing film formed by the light-absorbing composition is likely to have good crack resistance. In addition, the silicone resin containing an aryl group is likely to have high compatibility or dispersibility with phosphonic acid and ultraviolet absorbers, and it is difficult to aggregate the ultraviolet absorber. Specific examples of the silicone resin include KR-255, KR-300, KR-2621-1, KR-211, KR-311, KR-216, KR-212, KR-251, and KR-5230. These are all silicone resins manufactured by Shin-Etsu Chemical Co., Ltd.

[0043] In the light-absorbing composition, the ratio of the content of the ultraviolet absorber to the content of the solid component of the resin is not limited to a specific value. The ratio is, for example, 0.1% to 1.8% on a mass basis, and preferably 0.2% to 1.5%. This is advantageous from the viewpoint of suppressing problems such as a decrease in weather resistance or bleed-out.

[0044] The light-absorbing composition may further contain an alkoxysilane as needed. In this case, a siloxane bond (-Si-O-Si-) is formed by the hydrolysis and polycondensation of the alkoxysilane, and the light-absorbing film is likely to have a dense structure. The alkoxysilane may be a monomer, or may be in the form of an oligomer or polymer in which hydrolysis and polycondensation have progressed to a certain extent, or may be a mixture thereof.

[0045] As the monomeric alkoxysilane, from the viewpoints of easy availability, easy reaction control, film adhesion, film weather resistance, etc., tetraethoxysilane, tetramethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, dimethyldimethoxysilane, diethyldimethoxysilane, dimethyldiethoxysilane, diethyldiethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, and 3-glycidoxypropylmethyldiethoxysilane, etc. can be mentioned. Within the range not affecting the operational effects of the present invention, one kind or a plurality of kinds of alkoxysilanes can be used.

[0046] When the light-absorbing composition contains these alkoxysilanes, it has the effect of suppressing the aggregation of the light absorber composed of the phosphonic acid and the metal component, and the addition amount of the phosphate ester compound functioning as a dispersant can be reduced.

[0047] An example of a method for preparing a light-absorbing composition will be described. A metal salt such as acetate is added to a predetermined solvent such as tetrahydrofuran (THF) and stirred to prepare Solution A, which is a solution of the metal salt. In the preparation of Solution A, a phosphate ester may be added. Next, phosphonic acid is added to a predetermined solvent such as THF and stirred to prepare Solution B. When the light-absorbing composition contains a plurality of types of phosphonic acids, each phosphonic acid may be added to a predetermined solvent such as THF and stirred, and then a plurality of preliminary solutions prepared for each type of phosphonic acid may be mixed to prepare Solution B. In the preparation of Solution B, alkoxysilane may be added as necessary. The phosphonic acid used in the preparation of Solution B is, for example, a phosphonic acid having an aryl group or a halogenated aryl group. While stirring Solution A, Solution B is added to Solution A and stirred for a predetermined time. Next, a predetermined solvent such as toluene is added to this solution and stirred to obtain Solution C. Next, Solution C is heated and subjected to a solvent removal treatment for a predetermined time to obtain Solution D. As a result, the solvent such as THF and the components generated by the dissociation of the metal salt such as acetic acid (boiling point: about 118°C) are removed, and a light absorber is formed by the phosphonic acid and the metal component. The temperature at which Solution C is heated is determined based on the boiling point of the component to be removed that has dissociated from the metal salt. In the solvent removal treatment, the solvent such as toluene (boiling point: about 110°C) used to obtain Solution C also volatilizes. Since it is desirable that this solvent remains to some extent in the light-absorbing composition, the amount of the solvent added and the time of the solvent removal treatment can be determined from this perspective. In addition, o-xylene (boiling point: about 144°C) can be used instead of toluene to obtain Solution C. In this case, since the boiling point of o-xylene is higher than that of toluene, the addition amount can be reduced to about one-fourth of the addition amount of toluene.

[0048] If necessary, the H liquid can be adjusted as follows. A metal salt such as acetate is added to a predetermined solvent such as THF and stirred to prepare an E liquid which is a solution of the metal salt. In the preparation of the E liquid, a phosphate ester may be added. Next, phosphonic acid is added to a predetermined solvent such as THF and stirred to prepare an F liquid. The phosphonic acid used in the preparation of the F liquid can be, for example, a phosphonic acid having an alkyl group or a halogenated alkyl group. While stirring the E liquid, the F liquid is added to the E liquid and stirred for a predetermined time. Next, a predetermined solvent such as toluene is added to this solution and stirred to obtain a G liquid. Next, the G liquid is subjected to a solvent removal treatment for a predetermined time while being heated to obtain an H liquid. Thereby, components generated by the dissociation of the solvent such as THF and the metal salt such as acetic acid (boiling point: about 118°C) are removed, and a light absorber is generated by the phosphonic acid and the metal component. The temperature at which the G liquid is heated is determined based on the boiling point of the component to be removed dissociated from the metal salt. In the solvent removal treatment, a solvent such as toluene (boiling point: about 110°C) used to obtain the G liquid also volatilizes. Since it is desirable that this solvent remains to some extent in the light-absorbing composition, the addition amount of the solvent and the time of the solvent removal treatment can be determined from this viewpoint. Note that o-xylene (boiling point: about 144°C) can also be used instead of toluene to obtain the G liquid. In this case, since the boiling point of o-xylene is higher than that of toluene, the addition amount can be reduced to about one-fourth of the addition amount of toluene.

[0049] An ultraviolet absorber having a hydroxy group and a carbonyl group in the molecule is added to a predetermined solvent such as toluene and stirred to obtain a U liquid. If necessary, the light-absorbing composition can be adjusted by mixing and stirring the U liquid and the D liquid together with a silicone resin. If necessary, the light-absorbing composition can also be adjusted by mixing and stirring the U liquid, the D liquid, and the H liquid together with a silicone resin. The U liquid may be added in the preparation of the D liquid or the preparation of the H liquid. For example, the U liquid may be added in the preparation of the C liquid and the preparation of the G liquid.

[0050] Using the light-absorbing composition, for example, the light-absorbing film 10 shown in FIG. 1 can be provided. The light-absorbing film 10 is obtained, for example, by curing a coating film of the light-absorbing composition. The light-absorbing film 10 contains a phosphonic acid, an ultraviolet absorber having a hydroxy group and a carbonyl group in the molecule, and a metal component. Thereby, the light-absorbing film 10 is likely to effectively absorb light in the short-wavelength region near a wavelength of 400 nm.

[0051] In the ultraviolet absorber of the light-absorbing film 10, preferably, the hydroxy group and the carbonyl group are arranged with 1 to 6 atoms therebetween. Thereby, the light-absorbing film 10 is more likely to effectively and appropriately absorb light near a wavelength of 400 nm.

[0052] In the transmittance spectrum of the light-absorbing film 10 at an incident angle of 0 degrees, the transmittance T at a wavelength of 400 nm 400 , the transmittance T at a wavelength of 550 nm 550 , and the transmittance T at a wavelength of 800 nm 800 satisfy 8 ≦ T 550 / T 400 and 8 ≦ T 550 / T 800 . Thereby, the light-abs orbing film 10 is likely to appropriately absorb ultraviolet rays and infrared rays in the wavelength region around the visible light region while exhibiting a high transmittance with respect to visible light.

[0053] In the light-absorbing film 10, the transmittance T 400 , the transmittance T 550 , and the transmittance T 800 preferably satisfy 12 ≦ T 550 / T 400 and 28 ≦ T 550 / T 800 , and more preferably 16 ≦ T 550 / T 400 and 60 ≦ T 550 / T 800 .

[0054] The ultraviolet absorber in the light absorption film 10 contains, for example, a benzophenone compound represented by the above formula (A1). Thereby, the light absorption film 10 can more surely and effectively absorb light in the short wavelength region near 400 nm in wavelength.

[0055] The ultraviolet absorber in the light absorption film 10 desirably contains a benzophenone compound represented by the above formula (A2). Thereby, the light absorption film 10 can more surely and effectively absorb light in the short wavelength region near 400 nm in wavelength.

[0056] The phosphonic acid in the light absorption film 10 is represented by, for example, the above formula (B). Thereby, the light absorption film 10 can effectively absorb light in the wavelength region longer than 750 nm in wavelength and can more surely and effectively absorb light in the short wavelength region near 400 nm in wavelength.

[0057] The metal component in the light absorption film 10 is, for example, a copper component. In this case, the light absorption film 10 can more surely and effectively absorb light in the short wavelength region near 400 nm in wavelength.

[0058] The light absorption film 10 may further contain, for example, a phosphate ester. Due to the function of the phosphate ester, the light absorber is likely to be appropriately dispersed in the light absorption film 10.

[0059] As shown in FIG. 1, for example, an optical filter 1a provided with the light absorption film 10 can be provided. The optical filter 1a can effectively absorb light in the short wavelength region near 400 nm in wavelength.

[0060] In the transmission spectrum of the optical filter 1a at an incident angle of 0 degrees, at a wavelength of 400 nm the transmittance T 400 at a wavelength of 550 nm, the transmittance T 550 and at a wavelength of 800 nm, the transmittance T 800 satisfy, for example, the conditions of 8 ≦ T 550 / T 400 and 8 ≦ T 550 / T 800 .

[0061] In the optical filter 1a, the transmittance T 400 , the transmittance T 550 , and the transmittance T 800 are desirably 12 ≤ T 550 / T 400 and 28 ≤ T 550 / T 800 satisfy the conditions, and more desirably 16 ≤ T 550 / T 400 and 60 ≤ T 550 / T 800 satisfy the conditions. Also, in the optical filter 1a, the transmittance T 400 , the transmittance T 550 , and the transmittance T 800 are, for example, T 550 / T 400 ≤ 120 and T 550 / T 800 ≤ 1 × 10 7 satisfy the conditions, and desirably T 550 / T 400 ≤ 100 and T 550 / T 800 ≤ 1 × 10 6 satisfy the conditions.

[0062] In the transmission spectrum of the optical filter 1a at an incident angle of 0 degrees, desirably, the following conditions (I), (II), (III), (IV), (V), (VI), (VII), (VIII), (IX), and (X) are further satisfied. Thereby, the optical filter 1a is likely to exhibit desired characteristics. (I) The maximum transmittance T M 300-380 at wavelengths from 300 nm to 380 nm is 1% or less. (II) The transmittance T 400 at a wavelength of 400 nm is 20% or less. (III) The UV cut-off wavelength λ UV CF at which the transmittance becomes 50% in the wavelength range from 400 nm to 490 nmsatisfies the condition 405 nm ≤ λ UV CF ≤ 480 nm. (IV) The average value T of the transmittance at wavelengths from 480 nm to 580 nm A 480-580 is 78% or more. (V) The IR cut-off wavelength λ, which is the wavelength at which the transmittance becomes 50% at wavelengths from 590 nm to 700 nm IR CF satisfies the condition 600 nm ≤ λ IR CF ≤ 700 nm. (VI) The average value T of the transmittance at wavelengths from 700 nm to 750 nm A 700-750 is 10% or less. (VII) The maximum transmittance T at wavelengths from 800 nm to 950 nm M 800-950 is 3% or less . (VIII) The maximum transmittance T at wavelengths from 700 nm to 1000 nm M 700-1000 is 10% or less is. (IX) The maximum transmittance T at wavelengths from 700 nm to 1100 nm M 700-1100 is 15% or less is. (X) The maximum transmittance T at wavelengths from 700 nm to 1200 nm M 700-1200 is 20% or less is.

[0063] Regarding the condition of (I) above, in the transmittance spectrum of the optical filter 1a at an incident angle of 0 degrees, desirably, the maximum transmittance T at wavelengths from 300 nm to 385 nm M 300-385 is 1% or less, and more desirably, the maximum transmittance T at wavelengths from 300 nm to 390 nm M 300-390 is 1% or less.

[0064] Regarding the condition of (II) above, the transmittance T 400 is desirably 10% or less, and more desirably is 5% or less.

[0065] Regarding the condition of (III) above, preferably 405 nm ≤ λ UV CF ≤ 470 nm is satisfied, more preferably 405 nm ≤ λ UV CF ≤ 460 nm is satisfied.

[0066] Regarding the condition of (IV) above, the average value T A 480-580 is preferably 82% or more.

[0067] Regarding the condition of (V) above, preferably 620 nm ≤ λ IR CF ≤ 680 nm is satisfied.

[0068] Regarding the condition of (VI) above, the average value T A 700-750 is preferably 3% or less.

[0069] Regarding the condition of (VII) above, the maximum transmittance T M 800-950 is preferably 1% or less, more preferably 0.5% or less.

[0070] Regarding the condition of (VIII) above, the maximum transmittance T M 700-1000 is preferably 7% or less, more preferably 5% or less.

[0071] Regarding the condition of (IX) above, the maximum transmittance T M 700-1100 is preferably 10% or less, more preferably 5% or less.

[0072] Regarding the condition of (X) above, the maximum transmittance T M 700-1200 is preferably 15% or less, more preferably 10% or less.

[0073] The transmission spectrum of the optical filter 1a at an incident angle of 0 degrees may satisfy, for example, the following conditions (α), (β), and (γ). (α) In the wavelength range of 300 nm to 450 nm, the difference λ RUV 1% between the maximum wavelength showing a transmittance of 1% and the minimum wavelength showing a transmittance of 1% (β) The difference λ IR CF between the IR cut-off wavelength λ UV CF and the UV cut-off wavelength λ R CF is 180 nm or more. (γ) In the wavelength range of 700 nm to 1200 nm, the difference λ RIR 1% between the maximum wavelength showing a transmittance of 1% and the minimum wavelength showing a transmittance of 1%

[0074] When the condition (α) is satisfied, the optical filter 1a can exhibit good ultraviolet absorption performance. When the condition (β) is satisfied, in a sensor such as a solid-state imaging device that receives the light passing through the optical filter 1a, sufficient visible light can be received. By satisfying the condition (γ), the optical filter 1a can exhibit good infrared absorption performance. Therefore, by satisfying the conditions (α), (β), and (γ), the optical filter 1a can exhibit the performance of well absorbing ultraviolet rays and infrared rays, that is, good UV-IR absorption performance.

[0075] Regarding the condition (γ), the difference λ RIR 1% is desirably 300 nm or more, more desirably is 350 nm or more.

[0076] The optical filter 1a is composed of, for example, only the light absorption film 10. In this case, the optical filter 1a can be used separately from, for example, an image sensor or an optical component. The optical filter 1a may be joined to the image sensor and the optical component. On the other hand, the optical filter 1a may be formed by applying the above light-absorbing composition to an image sensor or an optical component and curing the light-absorbing composition.

[0077] The thickness of the light absorption film 10 is not limited to a specific value. The thickness of the light absorption film 10 is, for example, 10 μm to 600 μm, may be 20 μm to 400 μm, or may be 30 μm to 300 μm.

[0078] The optical filter 1a can be produced, for example, by peeling the light absorption film 10 formed on a substrate from the substrate. In this case, the material of the substrate may be glass, resin, or metal. The surface of the substrate may be subjected to surface treatment such as coating using a fluorine-containing compound.

[0079] The optical filter 1a may be modified, for example, like the optical filter 1b shown in FIG. 2. Unless otherwise specified, the optical filter 1b is configured in the same manner as the optical filter 1a. Components of the optical filter 1b that are the same as or corresponding to those of the optical filter 1a are denoted by the same reference numerals, and detailed descriptions thereof are omitted. The description of the optical filter 1a applies to the optical filter 1b as long as there is no technical contradiction.

[0080] As shown in FIG. 2, the optical filter 1b includes a light absorption film 10 and a transparent dielectric substrate 20. The light absorption film 10 is formed parallel to one main surface of the transparent dielectric substrate 20. The light absorption film 10 may be in contact with, for example, one main surface of the transparent dielectric substrate 20. In this case, for example, the light absorption film 10 can be formed by applying the above light-absorbing composition to one main surface of the transparent dielectric substrate 20 and curing the light-absorbing composition.

[0081] The type of the transparent dielectric substrate 20 is not limited to a specific type. The transparent dielectric substrate 20 may have an absorption ability in the infrared region. The transparent dielectric substrate 20 may have an average spectral transmittance of 90% or more, for example, at a wavelength of 350 nm to 900 nm. The material of the transparent dielectric substrate 20 is not limited to a specific material, but is, for example, a predetermined glass or resin. When the material of the transparent dielectric substrate 20 is glass, the transparent dielectric substrate 20 may be, for example, a transparent glass made of silicate glass such as soda-lime glass and borosilicate glass, or a phosphate glass and a fluorophosphate glass containing coloring components such as Cu and Co. The phosphate glass and the fluorophosphate glass containing coloring components are, for example, infrared-absorbing glass and have light absorption properties themselves. When the light absorption film 10 is used together with the infrared-absorbing glass transparent dielectric substrate 20, the light absorption properties and transmission spectra of both can be adjusted to produce an optical filter having desired optical characteristics, and the degree of freedom in the design of the optical filter is high.

[0082] When the material of the transparent dielectric substrate 20 is resin, the resin is, for example, a cyclic olefin resin such as a norbornene resin, a polyarylate resin, an acrylic resin, a modified acrylic resin, a polyimide resin, a polyetherimide resin, a polysulfone resin, a polyethersulfone resin, a polycarbonate resin, or a silicone resin.

[0083] Each of the optical filters 1a and 1b may be modified to further include other functional films such as an infrared reflection film and an antireflection film. Such a functional film may be formed on the light absorption film 10 or the transparent dielectric substrate 20. For example, by providing the optical filter with an antireflection film, the transmittance in a predetermined wavelength range (for example, the visible light region) can be increased. The antireflection film may be configured as a layer of a low refractive index material such as MgF 2 and SiO 2 etc., and may be configured as a laminate of such a layer of a low refractive index material and a layer of a high refractive index material such as TiO 2 etc. , It may be configured as a dielectric multilayer film. Such an antireflection film can be formed by a method involving a physical reaction such as vacuum deposition and sputtering, or a method involving a chemical reaction such as CVD and sol-gel methods.

[0084] The optical filter may be configured, for example, with a light absorption film 10 disposed between two plate-shaped glasses. This improves the rigidity and mechanical strength of the optical filter. In addition, the main surface of the optical filter becomes hard, which is advantageous from the viewpoint of scratch prevention and the like. In particular, such advantages are important when a resin with relatively high flexibility is used as the binder or matrix in the light absorption film 10.

Example

[0085] The present invention will be described in more detail with reference to the examples. Note that the present invention is not limited to the following examples.

[0086] <Example 1> 4.500 g of copper acetate monohydrate and 240 g of tetrahydrofuran (THF) were mixed and stirred for 3 hours to obtain a copper acetate solution. Next, to this obtained copper acetate solution, 1.646 g of Prysurf A208N (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), which is a phosphate ester compound, was added and stirred for 30 minutes to obtain a solution of 1-A. 40 g of THF was added to 0.706 g of phenylphosphonic acid and stirred for 30 minutes to obtain a solution of 1-B1. 40 g of THF was added to 4.230 g of 4-bromophenylphosphonic acid and stirred for 30 minutes to obtain a solution of 1-B2. Next, the solution of 1-B1 and the solution of 1-B2 were mixed and stirred for 1 minute, and 8.664 g of methyltriethoxysilane (MTES) (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KBE-13) and 2.830 g of tetraethoxysilane (TEOS) (special grade manufactured by Kishida Chemical Co., Ltd.) were added to this mixed solution and further stirred for 1 minute to obtain a solution of 1-B and then added to the solution of 1-A and stirred for 1 hour to obtain a light absorption film forming solution. was obtained. While stirring the 1-A solution, the 1-B solution was added to the 1-A solution, and the mixture was stirred at room temperature for 1 minute. Next, 140 g of toluene was added to this solution, and then the mixture was stirred at room temperature for 1 minute to obtain the 1-C solution. The 1-C solution was placed in a flask and subjected to solvent removal treatment using a rotary evaporator (manufactured by Tokyo Rika Kikai Co., Ltd., model: N-1110SF) while heating with an oil bath (manufactured by Tokyo Rika Kikai Co., Ltd., model: OSB-2100). The set temperature of the oil bath was adjusted to 105°C. Thereafter, the solution after the solvent removal treatment was taken out from the flask to obtain the 1-D solution. In this way, the 1-D solution containing an aryl phosphonic acid, a copper component, and a phosphate ester was obtained.

[0087] Uvinul 3049 (manufactured by BASF, 2,2'-dihydroxy-4, 4'-dimethoxybenzophenone) 0.12 g and 99.88 g of toluene were mixed and stirred for 30 minutes to obtain the 1-U solution containing the ultraviolet absorber.

[0088] 4.500 g of copper acetate monohydrate and 240 g of THF were mixed and stirred for 3 hours to obtain a copper acetate solution. Next, 2.572 g of Prysurf A208N, which is a phosphate ester compound, was added to the obtained copper acetate solution and stirred for 30 minutes to obtain the 1-E solution. 40 g of THF was added to 2.886 g of n-butylphosphonic acid and stirred for 30 minutes to obtain the 1-F solution. While stirring the 1-E solution, the 1-F solution was added, and the mixture was further stirred at room temperature for 1 minute. Next, the 1-U solution containing the ultraviolet absorber was added to this solution, and then the mixture was stirred at room temperature for 1 minute to obtain the 1-G solution. The 1-G solution was placed in a flask and subjected to solvent removal treatment using a rotary evaporator while heating with an oil bath. The set temperature of the oil bath was adjusted to 105°C. Thereafter, the solution after the solvent removal treatment was taken out from the flask to obtain the 1-H solution. In this way, the 1-H solution containing an alkyl phosphonic acid, a copper component, a phosphate ester, and an ultraviolet absorber was obtained.

[0089] 8.800 g of silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR-300) was added to the 1-D liquid, and the mixture was stirred for 30 minutes to obtain the 1-I liquid. An amount corresponding to 40% by mass of the total amount of the 1-H liquid was added to the 1-I liquid, and the mixture was further stirred for 30 minutes to obtain the light-absorbing composition according to Example 1. The light-absorbing composition according to Example 1 contained an aryl phosphonic acid, an alkyl phosphonic acid, a copper component, a phosphate ester, an alkoxysilane or its hydrolyzate, a polymerizable resin (silicone resin), and an ultraviolet absorber. The content of each component of the light-absorbing composition according to Example 1 is shown in Table 1. In Table 1, on the premise that the content of the solid content in the resin is 50% by mass, the ratio of the content of the ultraviolet absorber to the content of the solid content of the resin was calculated.

[0090] The light-absorbing composition according to Example 1 was applied using a dispenser to a range of 40 mm × 40 mm at the center of one main surface of a transparent glass substrate (manufactured by SCHOTT, product name: D263 T eco) made of borosilicate glass having dimensions of 76 mm × 76 mm × 0.21 mm to form a coating film. After the obtained coating film was sufficiently dried at room temperature, it was placed in an oven and heat-treated at 45 °C for 2 hours and at 85 °C for 30 minutes to volatilize the solvent and cure the coating film. Further, the transparent glass substrate was placed in an environment of a temperature of 85 °C and a relative humidity of 85% for about 2 hours to promote the hydrolysis reaction of the alkoxysilane. In this way, the light-absorbing film according to Example 1 was formed, and the optical filter according to Example 1 was obtained.

[0091] (Transmission spectrum measurement) Using an ultraviolet-visible-near-infrared spectrophotometer (manufactured by JASCO Corporation, product name: V-670), the transmission spectrum at an incident angle of 0° of the optical filter according to Example 1 was measured. The transmission spectrum of the optical filter according to Example 1 is shown in FIG. 3. Also, the characteristics regarding the transmittance read from FIG. 3 are shown in Tables 2, 3, and 4. From these results, the transmittance of the optical filter according to Example 1 at 400 nm is 5% or less, and it was confirmed that the optical filter according to Example 1 has desirable absorption characteristics and good optical characteristics for light in the short-wavelength region including ultraviolet light. For reference, the transmission spectrum of D263 T eco used as the transparent glass substrate is shown in FIG. 11.

[0092] (Thickness measurement) Using a laser displacement meter (manufactured by KEYENCE CORPORATION, product name: LK-H008), the distance to the surface of the optical filter was measured, and by subtracting the thickness of the transparent glass substrate, the thickness of the light absorption film was calculated. The results are shown in Table 2.

[0093] <Example 2> A light-absorbing composition according to Example 2 was prepared and a light absorption film was formed to produce an optical filter according to Example 2 in the same manner as in Example 1, except that a 2-U liquid containing an ultraviolet absorber prepared by mixing 0.04 g of Uvinul 3049 (manufactured by BASF) and 99.96 g of toluene was used instead of the 1-U liquid used in the preparation of the light-absorbing composition according to Example 1. The transmission spectrum at an incident angle of 0° of the optical filter according to Example 2 was measured in the same manner as in Example 1. In addition, the thickness of the light absorption film in the optical filter according to Example 2 was calculated in the same manner as in Example 1. The transmission spectrum at an incident angle of 0° of the optical filter according to Example 2 is shown in FIG. 4. The parameters readable from the transmission spectrum of FIG. 4 and the film thickness of the light absorption film are shown in Tables 2 to 4. From these results, the transmittance of the optical filter according to Example 2 at 400 nm is 5% or less, and it was confirmed that the optical filter according to Example 2 has desirable absorption performance and good optical characteristics for light in the short-wavelength region including ultraviolet light.

[0094] <Example 3> 4.500 g of copper acetate monohydrate and 240 g of tetrahydrofuran (THF) were mixed and stirred for 3 hours to obtain a copper acetate solution. Next, 1.646 g of Prysurf A208N, which is a phosphate ester compound, was added to the obtained copper acetate solution and stirred for 30 minutes to obtain a 3-A solution. 40 g of THF was added to 0.706 g of phenylphosphonic acid and stirred for 30 minutes to obtain a 3-B1 solution. 40 g of THF was added to 4.230 g of 4-bromophenylphosphonic acid and stirred for 30 minutes to obtain a 3-B2 solution. Next, the 3-B1 solution and the 3-B2 solution were mixed and stirred for 1 minute, and 8.664 g of methyltriethoxysilane (MTES) (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KBE-13) and 2.830 g of tetraethoxysilane (TEOS) (special grade, manufactured by Kishida Chemical Co., Ltd.) were added to this mixed solution and stirred for another 1 minute to obtain a 3-B solution. While stirring the 3-A solution, the 3-B solution was added to the 3-A solution and stirred at room temperature for 1 minute. Next, 140 g of toluene was added to this solution and stirred at room temperature for 1 minute to obtain a 3-C solution. The 3-C solution was placed in a flask and subjected to solvent removal treatment using a rotary evaporator (manufactured by Tokyo Rikakikai Co., Ltd., model: N-1110SF) while heating with an oil bath (manufactured by Tokyo Rikakikai Co., Ltd., model: OSB-2100). The set temperature of the oil bath was adjusted to 105°C. Thereafter, the solution after the solvent removal treatment was taken out from the flask to obtain a 3-D solution. In this way, a 3-D solution containing an arylphosphonic acid, a copper component, and a phosphate ester was obtained.

[0095] 5 g of Uvinul 3050 (2,2’,4,4’-tetrahydroxybenzophenone, manufactured by BASF), which is an ultraviolet absorber, and 95 g of ethanol were mixed and stirred for 30 minutes to obtain a 3-U solution containing an ultraviolet absorber.

[0096] 4.500 g of copper acetate monohydrate and 240 g of THF were mixed and stirred for 3 hours to obtain a copper acetate so lution. Next, 2.572 g of Prysurf A208N, which is a phosphate ester compound, was added to the obtained copper acetate solution and stirred for 30 minutes to obtain a 3-E solution. 40 g of THF was added to 2.886 g of n-butylphosphonic acid and stirred for 30 minutes to obtain a 3-F solution. The 3-E so While stirring, 3-F solution was added to 3-E solution, and the mixture was stirred at room temperature for 1 minute. Next, 100 g of toluene was added to this solution, and the mixture was stirred at room temperature for 1 minute to obtain 3-G solution. The 3-G solution was placed in a flask and subjected to solvent removal treatment using a rotary evaporator while heating with an oil bath. The set temperature of the oil bath was adjusted to 105°C. Thereafter, the 3-H solution after solvent removal treatment was taken out from the flask to obtain 3-H solution. In this way, 3-H solution containing an alkyl phosphonic acid, a copper component, and a phosphate ester was obtained.

[0097] 8.800 g of silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR-300) was added to 3-D solution, and the mixture was stirred for 30 minutes to obtain 3-I solution. An amount corresponding to 40% by mass of the total amount of 3-H solution was added to 3-I solution, and further 0.96 g of 3-U solution containing an ultraviolet absorber was added and stirred for 30 minutes to obtain the light-absorbing composition according to Example 3. The light-absorbing composition according to Example 3 contained an aryl phosphonic acid, an alkyl phosphonic acid, a copper component, a phosphate ester, an alkoxysilane or its hydrolyzate, a polymerizable resin (silicone resin), and an ultraviolet absorber.

[0098] A transparent glass substrate (manufactured by SCHOTT, product name: D263 T eco) made of borosilicate glass with dimensions of 76 mm × 76 mm × 0.21 mm was coated with the light-absorbing composition according to Example 3 using a dispenser in a range of 40 mm × 40 mm at the center of one main surface to form a coating film. After the obtained coating film was sufficiently dried at room temperature, it was placed in an oven and heat-treated at 45 °C for 2 hours and at 85 °C for 30 minutes to volatilize the solvent and cure the coating film. Further, the transparent glass substrate was placed in an environment of a temperature of 85 °C and a relative humidity of 85% for about 2 hours to promote the hydrolysis reaction of alkoxysilane. In this way, the light-absorbing film according to Example 3 was formed, and the optical filter according to Example 3 was obtained. The transmission spectrum of the optical filter according to Example 3 at an incident angle of 0° was measured in the same manner as in Example 1. In addition, the thickness of the light-absorbing film in the optical filter according to Example 3 was calculated in the same manner as in Example 1. The transmission spectrum of the optical filter according to Example 3 at an incident angle of 0° is shown in FIG. 5. The parameters that can be read from the transmission spectrum of FIG. 5 and the film thickness of the light-absorbing film are shown in Tables 2 to 4. From these results, the transmittance of the optical filter according to Example 3 at 400 nm is 5% or less, and it was confirmed that the optical filter according to Example 3 has desirable absorption performance and good optical characteristics with respect to light in the short wavelength region including ultraviolet light.

[0099] <Example 4> Instead of the 3-U solution used in the preparation of the light-absorbing composition according to Example 3, a 4-U solution containing an ultraviolet absorber prepared by mixing 1.67 g of Uvinul 3050 (manufactured by BASF) and 98.33 g of toluene was used. In the same manner as in Example 3, a light-absorbing composition according to Example 4 was prepared, and a light-absorbing film was formed to fabricate an optical filter according to Example 4. The transmission spectrum of the optical filter according to Example 4 at an incident angle of 0° was measured in the same manner as in Example 1. In addition, the thickness of the light-absorbing film in the optical filter according to Example 4 was calculated in the same manner as in Example 1. The transmission spectrum of the optical filter according to Example 4 at an incident angle of 0° is shown in FIG. 6. The parameters observable from the transmission spectrum of FIG. 6 and the film thickness of the light-absorbing film are shown in Tables 2 to 4. From these results, the transmittance of the optical filter according to Example 4 at 400 nm is 5% or less, and it was confirmed that the optical filter according to Example 4 has desirable absorption performance and good optical characteristics with respect to light in the short wavelength region including ultraviolet rays.

[0100] <Comparative Example 1> 0.250 g of Uvinul 3049 (manufactured by BASF), which is an ultraviolet absorber, and 12.25 g of toluene were mixed and stirred for 30 minutes to dissolve the ultraviolet absorber. Then, 25.000 g of a silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR-300) was added to the solution and stirred for 30 minutes to obtain an ultraviolet-absorbing composition according to Comparative Example 1.

[0101] The ultraviolet-absorbing composition according to Comparative Example 1 was applied using a dispenser to a range of 40 mm × 40 mm at the center of one main surface of a transparent glass substrate (manufactured by SCHOTT, product name: D263 T eco) made of borosilicate glass having dimensions of 76 mm × 76 mm × 0.21 mm to form a coating film. The obtained coating film was placed in an oven and heat-treated at 45°C for 2 hours and at 85°C for 1 hour to volatilize the solvent and cure the coating film. In this way, a light-absorbing film according to Comparative Example 1 was formed, and an ultraviolet-absorbing filter according to Comparative Example 1 was obtained.

[0102] The transmission spectrum of the ultraviolet absorption filter according to Comparative Example 1 at an incident angle of 0° was measured in the same manner as in Example 1. In addition, the thickness of the light absorption film in the ultraviolet absorption filter according to Comparative Example 1 was calculated in the same manner as in Example 1. The transmission spectrum of the ultraviolet absorption filter according to Comparative Example 1 at an incident angle of 0° is shown in FIG. 7. Table 2 to 4 show each parameter observable from the transmission spectrum of FIG. 7 and the film thickness of the light absorption film. From these results, it was found that the ultraviolet absorption filter according to Comparative Example 1 has a high transmittance of 40.78% at a wavelength of 400 nm and has a problem with respect to the absorption of light in the vicinity of a wavelength of 400 nm. This is due to the absorption characteristics of the Uvinul 3049 dye, and it was confirmed that Uvinul 3049 alone cannot sufficiently absorb in the vicinity of 400 nm.

[0103] <Comparative Example 2> An ultraviolet absorbing composition according to Comparative Example 2 was prepared in the same manner as in Comparative Example 1, except that Uvinul 3050 (manufactured by BASF) was used instead of the ultraviolet absorber used in the preparation of the ultraviolet absorbing composition according to Comparative Example 1, and a light absorption film was formed to produce an ultraviolet absorption filter according to Comparative Example 2. The transmission spectrum of the ultraviolet absorption filter according to Comparative Example 2 at an incident angle of 0° was measured in the same manner as in Example 1. In addition, the thickness of the light absorption film in the ultraviolet absorption filter according to Comparative Example 2 was calculated in the same manner as in Example 1. The transmission spectrum of the ultraviolet absorption filter according to Comparative Example 2 at an incident angle of 0° is shown in FIG. 8. Table 2 to 4 show each parameter observable from the transmission spectrum of FIG. 8 and the film thickness of the light absorption film.

[0104] <Comparative Example 3> 4.500 g of copper acetate monohydrate and 240 g of tetrahydrofuran (THF) were mixed and stirred for 3 hours to obtain a copper acetate solution. Next, 1.646 g of Prysurf A208N (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), which is a phosphate ester compound, was added to the obtained copper acetate solution and stirred for 30 minutes to obtain a 13-A solution. 40 g of THF was added to 0.706 g of phenylphosphonic acid and stirred for 30 minutes to obtain a 13-B1 solution. 40 g of THF was added to 4.230 g of 4-bromophenylphosphonic acid and stirred for 30 minutes to obtain a 13-B2 solution. The 13-B1 solution and the 13-B2 solution were mixed and stirred for 1 minute, and 8.664 g of methyltriethoxysilane (MTES) (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KBE-13) and 2.830 g of tetraethoxysilane (TEOS) (special grade, manufactured by Kishida Chemical Co., Ltd.) were added to this mixed solution, and further stirred for 1 minute to obtain a 13-B solution. While stirring the 13-A solution, the 13-B solution was added to the 13-A solution and stirred at room temperature for 1 minute. Next, 140 g of toluene was added to this solution, and then stirred at room temperature for 1 minute to obtain a 13-C solution. This 13-C solution was placed in a flask and subjected to solvent removal treatment using a rotary evaporator (manufactured by Tokyo Rikakikai Co., Ltd., model: N-1110SF) while heating with an oil bath (manufactured by Tokyo Rikakikai Co., Ltd., model: OSB-2100). The set temperature of the oil bath was adjusted to 105°C. Thereafter, the solution after the solvent removal treatment was taken out from the flask to obtain a 13-D solution. In this way, a 13-D solution containing an aryl phosphonic acid, a copper component, a phosphate ester, and an alkoxysilane or its hydrolyzate was obtained.

[0105] 4.500 g of copper acetate monohydrate and 240 g of THF were mixed and stirred for 3 hours to obtain a copper acetate solution Next, 2.572 g of Prysurf A208N, which is a phosphate ester compound, was added to the obtained copper acetate solution and stirred for 30 minutes to obtain a 13-E solution. Also, 40 g of THF was added to 2.886 g of n-butylphosphonic acid and stirred for 30 minutes to obtain a 13-F solution. While stirring the 13-E liquid, the 13-F liquid was added to the 13-E liquid and stirred at room temperature for 1 minute. Next, 100 g of toluene was added to this solution, and then stirred at room temperature for 1 minute to obtain the 13-G liquid. The 13-G liquid was placed in a flask and subjected to solvent removal treatment using a rotary evaporator while heating with an oil bath. The set temperature of the oil bath was adjusted to 105°C. Thereafter, the liquid after the solvent removal treatment was taken out from the flask to obtain the 13-H liquid. In this way, a 13-H liquid containing an alkyl phosphonic acid, a copper component, and a phosphate ester was obtained.

[0106] 8.800 g of a silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR-300) was added to the 13-D liquid and stirred for 30 minutes to obtain the 13-I liquid. An amount corresponding to 40% by mass of the total amount of the 13-H liquid was added to the 13-I liquid and stirred for 30 minutes to obtain the light-absorbing composition according to Comparative Example 3. The light-absorbing composition according to Comparative Example 3 contained an aryl phosphonic acid, an alkyl phosphonic acid, a copper component, a phosphate ester, an alkoxysilane or its hydrolyzate, and a polymerizable resin.

[0107] The light-absorbing composition according to Comparative Example 3 was applied using a dispenser to a 40 mm × 40 mm range at the center of one main surface of a transparent glass substrate (manufactured by SCHOTT, product name: D263 T eco) made of borosilicate glass having dimensions of 76 mm × 76 mm × 0.21 mm to form a coating film. After the obtained coating film was sufficiently dried at room temperature, it was placed in an oven and heat-treated at 45°C for 2 hours and at 85°C for 30 minutes to volatilize the solvent and cure the coating film. Further, the transparent glass substrate was placed in an environment of a temperature of 85°C and a relative humidity of 85% for about 2 hours to promote the hydrolysis reaction of the alkoxysilane. In this way, the light-absorbing film according to Comparative Example 3 was formed, and the optical filter according to Comparative Example 3 was obtained.

[0108] The transmittance spectrum of the optical filter according to Comparative Example 3 at an incident angle of 0° was measured in the same manner as in Example 1. In addition, the thickness of the light absorption film in the optical filter according to Comparative Example 3 was calculated in the same manner as in Example 1. The transmittance spectrum of the optical filter according to Comparative Example 3 at an incident angle of 0° is shown in FIG. 9. The parameters observable from the transmittance spectrum in FIG. 9 and the film thickness of the light absorption film are shown in Tables 2 to 4. From these results, it was confirmed that the transmittance of the optical filter according to Comparative Example 3 at 400 nm was 35.06%, and the ultraviolet absorption characteristics of the optical filter according to Comparative Example 3 were insufficient.

[0109] <Comparative Example 4> An ultraviolet-absorbing composition according to Comparative Example 1 was applied using a dispenser to a 40 mm × 40 mm range at the center of one main surface of a transparent glass substrate (manufactured by SCHOTT, product name: D263 T eco) made of borosilicate glass having dimensions of 76 mm × 76 mm × 0.21 mm to form a coating film. The obtained coating film was placed in an oven and heat-treated at 45°C for 2 hours and at 85°C for 1 hour to volatilize the solvent and cure the coating film to form a light absorption film. Next, an optically absorbing composition according to Comparative Example 3 was similarly applied to the other main surface of the transparent glass substrate to form a coating film. After the obtained coating film was sufficiently dried at room temperature, it was placed in an oven and heat-treated at 45°C for 2 hours and at 85°C for 30 minutes to volatilize the solvent and cure the coating film. Then, the transparent glass substrate was placed in an environment of a temperature of 85°C and a relative humidity of 85% for about 2 hours to promote the hydrolysis reaction of the alkoxysilane. In this way, light absorption films according to Comparative Example 4 were formed on both surfaces of the transparent glass substrate to obtain an optical filter according to Comparative Example 4.

[0110] The transmittance spectrum of the optical filter according to Comparative Example 4 at an incident angle of 0° was measured in the same manner as in Example 1. In addition, the thickness of the light absorption film in the optical filter according to Comparative Example 4 was calculated in the same manner as in Example 1. The transmittance of the optical filter according to Comparative Example 4 at an incident angle of 0° is shown in FIG. 1 It is shown in 0. Each parameter that can be read from the transmission spectrum and the film thickness of the light absorption film are shown in Tables 2 to 4. From these results, the transmittance of the optical filter according to Comparative Example 4 at a wavelength of 400 nm is as large as 14.52%, and it was difficult to say that the optical filter according to Comparative Example 4 had sufficient light absorption characteristics. For this reason, it was found that there were difficulties in light absorption in the vicinity of a wavelength of 400 nm when the layer containing the ultraviolet absorber and the layer containing copper phosphonate were separately formed and simply stacked. Therefore, it is suggested that combining a predetermined ultraviolet absorber and a metal component in the same layer as in Examples 1 to 4 is advantageous from the viewpoint of light absorption in the vicinity of a wavelength of 400 nm.

[0111] The UV cut-off wavelength λ of the optical filters according to Examples 1 to 4 UV CF is 445 nm, 434 nm, 436 nm, and 430 nm, respectively. In addition, the transmittance T of the optical filters according to Examples 1 to 4 400 is 1.49%, 4.93%, 1.82%, and 4. 54%, respectively. On the other hand, the ultraviolet absorption filters according to Comparative Examples 1 and 2 include filters that utilize the light absorption performance of a benzophenone-based ultraviolet absorber alone. The UV cut-off wavelength λ of the ultraviolet absorption filters according to Comparative Examples 1 and 2 UV CF is 402 nm and 398 nm, respectively. In addition, the transmittance T of the ultraviolet absorption filters according to Comparative Examples 1 and 2 400 is 40 .78% and 57.15%, respectively. The optical filter according to Comparative Example 4 includes a light absorption film containing a benzophenone-based ultraviolet absorber alone on both surfaces of a transparent glass substrate and a light absorption film containing phosphonic acid and a copper component. The UV cut-off wavelength λ of the optical filter according to Comparative Example 4 UV CF is 412 nm, and the transmittance T of the ultraviolet absorption filters according to Comparative Examples 1 and 2 400 is , 14.52%. Therefore, the UV cut-off wavelength λ of the optical filters according to the examples UV CFis approximately 30 nm greater than the UV cut-off wavelength λ of the ultraviolet absorbing filters according to Comparative Examples 1 and 2, and is approximately 15 nm or more greater than the UV cut-off wavelength λ of the optical filter according to Comparative Example 4. Further, the transmittance T of the optical filter according to the Examples is approximately 35 points or less smaller than T400 of the optical filters according to Comparative Examples 1 and 2, and is approximately 10 points or less smaller than the transmittance T of the optical filter according to Comparative Example 4. From these facts, it is understood that the light absorption characteristics in the short wavelength region including ultraviolet rays of the optical filter according to the present invention can be expressed on the longer wavelength side than the light absorption characteristics exhibited by the benzophenone-based ultraviolet absorber alone. The mechanism for such an effect is not clear. For example, in the preparation process of the light-absorbing composition, the hydroxy group of the ultraviolet absorber interacts with the copper component to form a complex, and the absorption characteristics originally possessed by the ultraviolet absorber are shifted to the longer wavelength side, and it is considered that such an effect is obtained. UV CF is approximately 30 nm greater than the UV cut-off wavelength λ of the ultraviolet absorbing filters according to Comparative Examples 1 and 2, and is approximately 15 nm or more greater than the UV cut-off wavelength λ of the optical filter according to Comparative Example 4. Further, the transmittance T of the optical filter according to the Examples is approximately 35 points or less smaller than T400 of the optical filters according to Comparative Examples 1 and 2, and is approximately 10 points or less smaller than the transmittance T of the optical filter according to Comparative Example 4. From these facts, it is understood that the light absorption characteristics in the short wavelength region including ultraviolet rays of the optical filter according to the present invention can be expressed on the longer wavelength side than the light absorption characteristics exhibited by the benzophenone-based ultraviolet absorber alone. The mechanism for such an effect is not clear. For example, in the preparation process of the light-absorbing composition, the hydroxy group of the ultraviolet absorber interacts with the copper component to form a complex, and the absorption characteristics originally possessed by the ultraviolet absorber are shifted to the longer wavelength side, and it is considered that such an effect is obtained. UV CF is approximately 30 nm greater than the UV cut-off wavelength λ of the ultraviolet absorbing filters according to Comparative Examples 1 and 2, and is approximately 15 nm or more greater than the UV cut-off wavelength λ of the optical filter according to Comparative Example 4. Further, the transmittance T of the optical filter according to the Examples is approximately 35 points or less smaller than T400 of the optical filters according to Comparative Examples 1 and 2, and is approximately 10 points or less smaller than the transmittance T of the optical filter according to Comparative Example 4. From these facts, it is understood that the light absorption characteristics in the short wavelength region including ultraviolet rays of the optical filter according to the present invention can be expressed on the longer wavelength side than the light absorption characteristics exhibited by the benzophenone-based ultraviolet absorber alone. The mechanism for such an effect is not clear. For example, in the preparation process of the light-absorbing composition, the hydroxy group of the ultraviolet absorber interacts with the copper component to form a complex, and the absorption characteristics originally possessed by the ultraviolet absorber are shifted to the longer wavelength side, and it is considered that such an effect is obtained. 400 is approximately 30 nm greater than the UV cut-off wavelength λ of the ultraviolet absorbing filters according to Comparative Examples 1 and 2, and is approximately 15 nm or more greater than the UV cut-off wavelength λ of the optical filter according to Comparative Example 4. Further, the transmittance T of the optical filter according to the Examples is approximately 35 points or less smaller than T400 of the optical filters according to Comparative Examples 1 and 2, and is approximately 10 points or less smaller than the transmittance T of the optical filter according to Comparative Example 4. From these facts, it is understood that the light absorption characteristics in the short wavelength region including ultraviolet rays of the optical filter according to the present invention can be expressed on the longer wavelength side than the light absorption characteristics exhibited by the benzophenone-based ultraviolet absorber alone. The mechanism for such an effect is not clear. For example, in the preparation process of the light-absorbing composition, the hydroxy group of the ultraviolet absorber interacts with the copper component to form a complex, and the absorption characteristics originally possessed by the ultraviolet absorber are shifted to the longer wavelength side, and it is considered that such an effect is obtained. is approximately 30 nm greater than the UV cut-off wavelength λ of the ultraviolet absorbing filters according to Comparative Examples 1 and 2, and is approximately 15 nm or more greater than the UV cut-off wavelength λ of the optical filter according to Comparative Example 4. Further, the transmittance T of the optical filter according to the Examples is approximately 35 points or less smaller than T400 of the optical filters according to Comparative Examples 1 and 2, and is approximately 10 points or less smaller than the transmittance T of the optical filter according to Comparative Example 4. From these facts, it is understood that the light absorption characteristics in the short wavelength region including ultraviolet rays of the optical filter according to the present invention can be expressed on the longer wavelength side than the light absorption characteristics exhibited by the benzophenone-based ultraviolet absorber alone. The mechanism for such an effect is not clear. For example, in the preparation process of the light-absorbing composition, the hydroxy group of the ultraviolet absorber interacts with the copper component to form a complex, and the absorption characteristics originally possessed by the ultraviolet absorber are shifted to the longer wavelength side, and it is considered that such an effect is obtained. 400 is approximately 30 nm greater than the UV cut-off wavelength λ of the ultraviolet absorbing filters according to Comparative Examples 1 and 2, and is approximately 15 nm or more greater than the UV cut-off wavelength λ of the optical filter according to Comparative Example 4. Further, the transmittance T of the optical filter according to the Examples is approximately 35 points or less smaller than T400 of the optical filters according to Comparative Examples 1 and 2, and is approximately 10 points or less smaller than the transmittance T of the optical filter according to Comparative Example 4. From these facts, it is understood that the light absorption characteristics in the short wavelength region including ultraviolet rays of the optical filter according to the present invention can be expressed on the longer wavelength side than the light absorption characteristics exhibited by the benzophenone-based ultraviolet absorber alone. The mechanism for such an effect is not clear. For example, in the preparation process of the light-absorbing composition, the hydroxy group of the ultraviolet absorber interacts with the copper component to form a complex, and the absorption characteristics originally possessed by the ultraviolet absorber are shifted to the longer wavelength side, and it is considered that such an effect is obtained. is approximately 30 nm greater than the UV cut-off wavelength λ of the ultraviolet absorbing filters according to Comparative Examples 1 and 2, and is approximately 15 nm or more greater than the UV cut-off wavelength λ of the optical filter according to Comparative Example 4. Further, the transmittance T of the optical filter according to the Examples is approximately 35 points or less smaller than T400 of the optical filters according to Comparative Examples 1 and 2, and is approximately 10 points or less smaller than the transmittance T of the optical filter according to Comparative Example 4. From these facts, it is understood that the light absorption characteristics in the short wavelength region including ultraviolet rays of the optical filter according to the present invention can be expressed on the longer wavelength side than the light absorption characteristics exhibited by the benzophenone-based ultraviolet absorber alone. The mechanism for such an effect is not clear. For example, in the preparation process of the light-absorbing composition, the hydroxy group of the ultraviolet absorber interacts with the copper component to form a complex, and the absorption characteristics originally possessed by the ultraviolet absorber are shifted to the longer wavelength side, and it is considered that such an effect is obtained.

[0112] According to Examples 1 to 4, in the light-absorbing composition, it was found that it is advantageous for obtaining good characteristics that the ratio of the content of the ultraviolet absorber to the content of the solid component of the resin is 0.36% to 1.09% on a mass basis. On the other hand, according to Comparative Examples 1 and 2, in the ultraviolet-absorbing composition, the ratio of the content of the ultraviolet absorber to the content of the solid component of the resin is 2.00% on a mass basis, and a large amount of the dye is added to the resin. Nevertheless, the ultraviolet absorption characteristics of the ultraviolet absorption filters according to Comparative Examples 1 and 2 are significantly inferior to the ultraviolet absorption characteristics of the optical filters according to Examples 1 to 4. According to the present invention, it is understood that even if the ratio of the content of the ultraviolet absorber to the content of the solid component of the resin in the light-absorbing composition is adjusted to less than 2.00%, it is possible to realize good ultraviolet absorption characteristics. The small ratio of the content of the ultraviolet absorber to the content of the solid component of the resin is advantageous from the viewpoint of suppressing the occurrence of problems such as a decrease in weather resistance or bleed-out. In the light-absorbing composition, the ratio of the content of the ultraviolet absorber to the content of the solid component of the resin is desirably 0.1% to 1.8% on a mass basis, and more desirably 0.2 to 1.5%.

[0113] According to Examples 1 to 4, in the light-absorbing composition, the ratio of the content of the ultraviolet absorber to the content of the phosphonic acid is adjusted to 0.263% to 0.788% on a mass basis. From this result, it is understood that by using an extremely small amount of the ultraviolet absorber compared to the phosphonic acid, the optical filter can exhibit advantageous characteristics. By the ratio of the content of the ultraviolet absorber to the content of the phosphonic acid not being too large, a decrease in the transmittance of visible light can be suppressed. The ratio of the content of the ultraviolet absorber to the content of the phosphonic acid is desirably 0.1 to 5.0% on a mass basis, more desirably 0.1 to 3.0%, and even more desirably 0.1 to 1.0%.

[0114] According to Examples 1 to 4, in the light-absorbing composition, the ratio of the content of the ultraviolet absorber to the content of the copper component is 0.002 to 0.006 on a molar basis. Most of the copper component is presumed to form a complex with phosphonic acid. Therefore, the content of the copper component is larger than the content of the ultraviolet absorber. The ratio of the content of the ultraviolet absorber to the content of the copper component is preferably 0.001 to 0.100, more preferably 0.001 to 0.030 on a molar basis.

[0115] The optical filter of the present invention can be a laminate of a transparent substrate and a light-absorbing film, which is produced by applying a light-absorbing composition on a transparent glass substrate and curing the coating film to form an absorption film, like the optical filters according to Examples 1 to 4. On the other hand, the optical filter of the present invention may be an optical filter composed only of a light-absorbing film, which is obtained by peeling the light-absorbing film from a support after forming the light-absorbing film on the support. According to FIG. 11, it is understood that the transmittance spectrum of the transparent glass substrate does not significantly affect the optical properties shown in Tables 2 to 4. This is because the transmittance is substantially constant from a specific wavelength exceeding at least 350 nm to 1200 nm in the transmittance spectrum of the transparent glass substrate. Therefore, even an optical filter including a light-absorbing film and not including a transparent glass substrate can satisfy the conditions of 8 ≦ T 550 / T 400 and 8 ≦ T 550 / T 800 and can satisfy the conditions (I) to (X) and the conditions (α) to (γ).

[0116] (Detection of Ultraviolet Absorber) An ethanol elution test was conducted on the ultraviolet absorber contained in the light-absorbing film as follows.

[0117] <Example 5> First, in order to easily remove the light absorption film from the optical filter, the main surface of the transparent glass substrate on which the light absorption film is formed was surface-treated in advance with a fluorine compound to produce a fluorine-treated substrate. 0.1 g of a surface antifouling coating agent (manufactured by Daikin Industries, Ltd., product name: Optool DSX, concentration of active ingredient: 20% by mass) and 19.9 g of a hydrofluoroether-containing liquid (manufactured by 3M, product name: Novec 7100) were mixed and stirred for 5 minutes to prepare a fluorine treatment agent (concentration of active ingredient: 0.1% by mass). This fluorine treatment agent was applied to the main surface of a transparent glass substrate made of borosilicate glass (manufactured by SCHOTT, product name: D263 T eco) with dimensions of 76 mm × 76 mm × 0.21 mm to form a coating film, and the coating film of the fluorine treatment agent was dried by leaving it at room temperature for 24 hours. Then, the glass surface was gently wiped with a dust cloth containing Novec 7100 to remove excess fluorine treatment agent and the like, and a fluorine-treated substrate was obtained.

[0118] The entire amount of the light-absorbing composition obtained under the same conditions and by the same method as in Example 3 was applied to one main surface of the fluorine-treated substrate using a dispenser to form a coating film. After the obtained coating film was sufficiently dried at room temperature, it was placed in an oven and heat-treated at 45 °C for 2 hours and at 85 °C for 30 minutes. Thereby, the solvent contained in the light-absorbing composition was volatilized to cure the coating film. Further, the fluorine-treated substrate was placed in an environment of a temperature of 85 °C and a relative humidity of 85% for about 2 hours to promote the hydrolysis reaction of the alkoxysilane. In this way, the light absorption film according to Example 5 was formed, and the optical filter according to Example 5 was obtained. The ultraviolet absorber contained in the light absorption film was 2,2’-4,4’-tetrahydroxybenzophenone.

[0119] Next, the light absorption film was carefully peeled off from the optical filter according to Example 5 with tweezers to obtain a film-shaped light absorption film. The mass of the light absorption film was 9.500 g. In the production process of the light-absorbing composition according to Example 3, the 3-U liquid contained 5% by mass of an ultraviolet absorber, and 0.960 g of the 3-U liquid was added to prepare the light-absorbing composition. Therefore, the light absorption film contained 0.048 g of the ultraviolet absorber. The content of the ultraviolet absorber in the light absorption film was 0.505% on a mass basis.

[0120] A part of the light absorption film was cut to take out a 0.100 g fragment of the light absorption film, which was immersed in 1.000 g of ethanol for 24 hours to attempt to elute the ultraviolet absorber contained in the fragment of the light absorption film. The amount of the ultraviolet absorber contained in the 0.100 g fragment of the light absorption film was 0.000505 g. Assuming that all of the ultraviolet absorber contained in this fragment was eluted into ethanol, the ultraviolet absorber in ethanol could be calculated to be 0.050% by mass. On the other hand, as a control, a fragment of the light absorption film was similarly prepared using the light-absorbing composition according to Comparative Example 3 that does not contain an ultraviolet absorber, and it was immersed in 1.000 g of ethanol for 24 hours to observe the state of elution.

[0121] Since the ethanol containing the fragment of the light absorption film containing the ultraviolet absorber was colored yellow, it was suggested that a component having absorption in the region including the visible light region eluted from this light absorption film into ethanol. The ethanol containing the fragment of the light absorption film that does not contain an ultraviolet absorber remained almost colorless and transparent. In the ethanol containing the fragment of the light absorption film containing the ultraviolet absorber, LC-UV measurement was performed to identify the component having absorption in the region including the visible light region. For this measurement, a high-performance liquid chromatograph apparatus Ultimate 3000 manufactured by Thermo Fisher Scientific was used. The spectrum of the LC-UV chromatograph at a wavelength detection of 450 ± 150 nm in this measurement is shown in FIG. 12. In FIG. 12, the horizontal axis represents time [min], and the vertical axis represents the relative absorption intensity. Also, as a control, in the spectrum of the LC-UV chromatograph when only ethanol was used as a sample and the chromatograph when ethanol containing a fragment of the light absorption film that does not contain an ultraviolet absorber was used as a sample, the background (relative absorption intensity was almost zero) continued and no characteristic movement was observed.

[0122] In Fig. 12, when the time was 5.8 minutes, a peak of characteristic absorption intensity was observed. The absorption spectrum of this peak is shown in Fig. 13. The horizontal axis represents the wavelength [nm], and the vertical axis represents the relative absorbance. From the spectrum shown in Fig. 13, it was confirmed that there were characteristic absorption peaks at wavelengths of 285 nm and 342 nm.

[0123] Next, LC-MS measurement was performed on ethanol containing a fragment of the light-absorbing film containing the ultraviolet absorber. The measurement was carried out using a liquid chromatography mass spectrometer Orbitrap Fusion manufactured by Thermo Fisher Scientific. According to the mass spectrum which is the measurement result, the eluate in ethanol contains C 13 H 9 O 5 (negative ion detection) and C 13 H 11 O 5 (positive ion detection).

[0124] From the results of these LC-UV measurements and LC-MS measurements, it was estimated that the elution components from the light-absorbing film containing the ultraviolet absorber into ethanol included tetrahydroxybenzophenone which is the ultraviolet absorber.

[0125] (Identification of the elution components of the ultraviolet absorber) For the ethanol solution in which the ultraviolet absorber eluted from the fragment of the light-absorbing film according to Example 5, its transmittance spectrum was measured. The ethanol solution in which the ultraviolet absorber eluted was filled in a quartz cell (manufactured by JASCO Corporation: model number J / 1 / Q / 1) with an optical path length of 1 mm, and its transmittance spectrum was measured using an ultraviolet-visible near-infrared spectrophotometer (manufactured by JASCO Corporation, product name: V-670). The transmittance spectrum is shown in Fig. 14. In the wavelength range of 300 to 450 nm, the value obtained by dividing the minimum value of the transmittance by the maximum value of the transmittance was 0.895. The minimum value of the transmittance corresponded to the minimum value of the transmittance near a wavelength of 348 nm.

[0126] Next, 2,2’,4,4’-tetrahydroxybenzophenone, which is an ultraviolet absorber, was dissolved in ethanol, and five kinds of ethanol solutions in which ultraviolet absorbers were dissolved at 0.005%, 0.010%, 0.025%, 0.100%, and 0.200% on a mass basis were prepared. The transmission spectra of these ethanol solutions in which the ultraviolet absorbers were dissolved were measured in the same manner as the ethanol solution in which the ultraviolet absorber eluted from the fragment of the light absorption film containing the ultraviolet absorber according to Example 5. This transmission spectrum is shown in FIG. 15. In these transmission spectra, the wavelength corresponding to the minimum value of the transmittance was 348 nm. Further, in these transmission spectra, the value tr obtained by dividing the minimum value of the transmittance by the maximum value of the transmittance was determined. Table 5 and FIG. 16 show the relationship between the concentration η [%] of the ultraviolet absorber and the value tr. From the graph shown in FIG. 16, the relationship between the concentration η [%] and the value tr is η = (-1 / a)ln(tr / b) (where a = 1.213×10 1 , b = 1.004). The dashed-line graph shown in FIG. 16 is a calibration curve for determining the concentration of the ultraviolet absorber. In the ethanol solution in which the ultraviolet absorber eluted from the light absorption film according to Example 5, tr = 0.895. Therefore, when the light absorption film according to Example 5 was immersed in ethanol and the ultraviolet absorber was eluted into ethanol, it was suggested that it had the same light transmission characteristics as the ethanol solution in which the ultraviolet absorber was dissolved so that the concentration of the ultraviolet absorber was 0.0095% on a mass basis. When the ultraviolet absorber eluted from the fragment of the light absorption film containing the ultraviolet absorber according to Example 5 into ethanol, it is assumed that the ethanol contains 0.0095% of the ultraviolet absorber on a mass basis. From the above discussion, it is understood that when all of the ultraviolet absorber contained in the light absorption film elutes, the concentration of the ultraviolet absorber in the ethanol solution becomes 0.05%. Therefore, it is estimated that 19% of the ultraviolet absorber contained in the light absorption film eluted into ethanol from the fragment of the light absorption film containing the ultraviolet absorber according to Example 5 on a mass basis.

[0127]

[0128] <Comparative Example 5> ​A light-absorbing composition according to Comparative Example 5 was obtained under the same conditions and by the same method as in Example 5, except that the addition of all phosphonic acids and copper acetate monohydrate was omitted. In addition, a fluorine-treated substrate was prepared in the same manner as in Example 5. The entire amount of the light-absorbing composition according to Comparative Example 5 was applied to one main surface of the fluorine-treated substrate using a dispenser, and the resulting coating film was thoroughly dried at room temperature and then placed in an oven for heat treatment at 45 °C for 2 hours and at 85 °C for 30 minutes to volatilize the solvent and cure the coating film. Further, a transparent glass substrate was placed in an environment of a temperature of 85 °C and a relative humidity of 85% for about 2 hours to promote the hydrolysis reaction of the alkoxysilane. In this way, a light-absorbing film according to Comparative Example 5 was formed, and an optical filter according to Comparative Example 5 was obtained.

[0129] Next, the light-absorbing film was carefully peeled off from the optical filter according to Comparative Example 5 with tweezers to obtain a film-shaped light-absorbing film. The total amount of the obtained light-absorbing film was 4.200 g. In the production process of the light-absorbing composition according to Comparative Example 5, the liquid containing the ultraviolet absorber corresponding to the 3-U liquid contained 5% by mass of the ultraviolet absorber, and 0.960 g of the liquid was added to prepare the light-absorbing composition. Therefore, the light-absorbing film contained 0.048 g of the ultraviolet absorber, and the content of the ultraviolet absorber in the light-absorbing film was 1.130% on a mass basis.

[0130] A part of the light-absorbing film was cut, and a 0.100 g fragment of the light-absorbing film was taken out and immersed in 1.000 g of ethanol for 24 hours to attempt to elute the ultraviolet absorber contained in the fragment of the light-absorbing film. The ultraviolet absorber contained in 0.100 g of the light-absorbing film was 0.00113 g. Assuming that all of the ultraviolet absorber eluted into ethanol, the concentration of the ultraviolet absorber in the ethanol solution could be calculated to be 0.113% on a mass basis.

[0131] (Identification of the eluted components of the ultraviolet absorber) Regarding the ethanol solution in which the ultraviolet absorber was eluted from the fragment of the light-absorbing film according to Comparative Example 5, its transmission spectrum was measured. The ethanol solution in which the ultraviolet absorber was eluted had an optical path length of 1 It was filled into a quartz cell (manufactured by JASCO Corporation: model number J / 1 / Q / 1) with a path length of

[0132] When the ultraviolet absorber eluted into ethanol from a fragment of the light absorption film containing the ultraviolet absorber according to Comparative Example 5, it was assumed that the ethanol solution contained 0.0496% by mass of the ultraviolet absorber. From the above consideration, it is understood that when all of the ultraviolet absorber contained in the light absorption film eluted into ethanol, the concentration of the ultraviolet absorber in the ethanol solution would be 0.113%. Therefore, it was estimated that 43.89% of the ultraviolet absorber contained in the light absorption film eluted into ethanol.

[0133] Comparing Example 5 with Comparative Example 5, it is understood that more ultraviolet absorber eluted into ethanol in Comparative Example 5. In a light absorption film containing an ultraviolet absorber, it is presumed that when the ultraviolet absorber is contained together with a metal component such as copper, some interactions such as complexation occur, making it difficult for the ultraviolet absorber to elute into an organic solvent such as ethanol.

[0134] When a light absorption film containing an ultraviolet absorber and a metal component such as copper was immersed in ethanol for 24 hours, it was suggested that the amount of the ultraviolet absorber eluting into ethanol was adjusted to 10% - 40%, more quantitatively 10% - 20% by mass of the ultraviolet absorber contained in the light absorption film.

[0135]

Table 1

[0136]

Table 2

[0137]

Table 3

[0138]

Table 4

[0139]

Table 5

Explanation of Symbols

[0140] 1a, 1b Optical filters 10 Light absorption film 20 Transparent dielectric substrate

Claims

1. Phosphonic acid, an ultraviolet absorber having a hydroxy group and a carbonyl group in the molecule; A metal component is included. Light absorbing composition.

2. 2. The light absorbing composition of claim 1, wherein said hydroxy group and said carbonyl group are spaced apart by 1 to 6 atoms.

3. The light-absorbing film obtained by curing the light-absorbing composition has a transmittance T at a wavelength of 400 nm in a transmission spectrum at an incident angle of 0 degrees. 400 , transmittance T at a wavelength of 550 nm 550 , and transmittance T at a wavelength of 800 nm 800 8≦T 550 / T 400 and 8≦T 550 / T 800 The light-absorbing composition according to claim 1 or 2, which satisfies the above condition.

4. The light absorbing composition according to any one of claims 1 to 3, wherein the ultraviolet absorber comprises a benzophenone-based compound represented by the following formula (A1): 【Chemistry 1】 [In formula (A1), R 11 , R 12 , R 21 , and R 22 At least one of R is a hydroxy group. 11 , R 12 , R 21 , or R 22 is a functional group other than a hydroxy group, a plurality of R 11 , multiple R 12 , multiple R 21 , or multiple R 22 may be present, R 11 , R 12 , R 21 , and R 22 At least one of may not be present.

5. The light absorbing composition according to any one of claims 1 to 4, wherein the ultraviolet absorber comprises a benzophenone-based compound represented by the following formula (A2): 【Chemistry 2】 [In formula (A2), R 31 may be a hydroxy group, a carboxyl group, an aldehyde group, a halogen, an alkyl group having 1 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms in which one or more hydrogen atoms are substituted with halogen atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms in which one or more hydrogen atoms are substituted with halogen atoms; R 31 In formula (A2), R 41 and R 42 may be a hydroxy group, a carboxyl group, an aldehyde group, a halogen, an alkyl group having 1 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms in which one or more hydrogen atoms are substituted with halogen atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms in which one or more hydrogen atoms are substituted with halogen atoms; R 41 and R 42 In formula (A2), a plurality of R 41 may be present, and multiple R 42 may also be present.

6. 6. The light-absorbing composition according to claim 1, wherein the phosphonic acid is represented by the following formula (B): 【Chemistry 3】 [In formula (B), R 3 is an alkyl group, at least one hydrogen atom in the alkyl group a halogenated alkyl group in which at least one hydrogen atom is substituted with a halogen atom, an aryl group, or a halogenated aryl group in which at least one hydrogen atom in an aryl group is substituted with a halogen atom.

7. The light absorbing composition of any one of claims 1 to 6, wherein the metal component comprises a copper component.

8. The light-absorbing composition according to any one of claims 1 to 7, further comprising a phosphate ester.

9. Phosphonic acid, an ultraviolet absorber having a hydroxy group and a carbonyl group in the molecule; A metal component is included. Light absorbing film.

10. 10. The light absorbing film according to claim 9, wherein the hydroxy group and the carbonyl group are spaced apart by 1 to 6 atoms.

11. In the transmission spectrum at an incident angle of 0 degrees, the transmittance T 400 , Transmittance T at a wavelength of 550 nm 550 , and transmittance T at a wavelength of 800 nm 800 8≦T 550 / T 400 and 8≦T 550 / T 800 The light-absorbing film according to claim 9 or 10, which satisfies the above condition.

12. The light-absorbing film according to any one of claims 9 to 11, wherein the ultraviolet absorber comprises a benzophenone-based compound represented by the following formula (A1): 【Chemistry 4】 [In formula (A1), R 11 , R 12 , R 21 , and R 22 At least one of R is a hydroxy group. 11 , R 12 , R 21 , or R 22 is a functional group other than a hydroxy group, a plurality of R 11 , multiple R 12 , multiple R 21 , or multiple R 22 may be present, R 11 , R 12 , R 21 , and R 22 At least one of may not be present.

13. The light-absorbing film according to any one of claims 9 to 12, wherein the ultraviolet absorber comprises a benzophenone-based compound represented by the following formula (A2): 【Chemistry 5】 [In formula (A2), R 31 may be a hydroxy group, a carboxyl group, an aldehyde group, a halogen, an alkyl group having 1 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms in which one or more hydrogen atoms are substituted with halogen atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms in which one or more hydrogen atoms are substituted with halogen atoms; R 31 In formula (A2), R 41 and R 42 may be a hydroxy group, a carboxyl group, an aldehyde group, a halogen, an alkyl group having 1 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms in which one or more hydrogen atoms are substituted with halogen atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms in which one or more hydrogen atoms are substituted with halogen atoms; R 41 and R 42 In formula (A2), a plurality of R 41 may be present, and multiple R 42 may also be present.

14. The light absorbing film according to any one of claims 9 to 13, wherein the phosphonic acid is represented by the following formula (B): 【Chemistry 5】 [In formula (B), R 3 is an alkyl group, at least one hydrogen atom in the alkyl group a halogenated alkyl group in which at least one hydrogen atom is substituted with a halogen atom, an aryl group, or a halogenated aryl group in which at least one hydrogen atom in an aryl group is substituted with a halogen atom.

15. The light absorbing film according to any one of claims 9 to 14, wherein the metal component includes a copper component.

16. The light-absorbing film according to any one of claims 9 to 15, further comprising a phosphoric acid ester.

17. An optical filter comprising the light absorbing film according to any one of claims 9 to 16.

18. In the transmission spectrum at an incident angle of 0 degrees, the transmittance T 400 , Transmittance T at a wavelength of 550 nm 550 , and transmittance T at a wavelength of 800 nm 800 8≦T 550 / T 400 and 8≦T 550 / T 800 The optical filter according to claim 17 , which satisfies the following condition:

19. In the transmission spectrum, the following (I), (II), (III), (IV), (V), and (VI) 19. The method according to claim 18, further satisfying conditions (VII), (VIII), (IX), and (X). Optical filters. (I) The maximum transmittance in the wavelength range of 300 nm to 380 nm is 1% or less. (II) The transmittance at a wavelength of 400 nm is 20% or less. (III) UV cutoff wavelengths with a transmittance of 50% in the range of 400 nm to 490 nm Toe-off wavelength λ UV CF 405 nm≦λ UV CF The condition of ≦480 nm is satisfied. (IV) The average transmittance in the wavelength range of 480 nm to 580 nm is 78% or more. (V) IR cutoff wavelength λ, which is the wavelength at which the transmittance is 50% in the wavelength range of 590 nm to 700 nm IR CF 600 nm≦λ IR CF The condition of ≦700 nm is satisfied. (VI) The average transmittance in the wavelength range of 700 nm to 750 nm is 10% or less. (VII) The maximum transmittance in the wavelength range of 800 nm to 950 nm is 3% or less. (VIII) The maximum transmittance in the wavelength range of 700 nm to 1000 nm is 10% or less. (IX) The maximum transmittance in the wavelength range of 700 nm to 1100 nm is 15% or less. (X) The maximum transmittance in the wavelength range of 700 nm to 1200 nm is 20% or less.

20. 20. The optical filter according to claim 19, wherein the transmission spectrum further satisfies the following conditions (α), (β), and (γ): (α) In the wavelength range of 300 nm to 450 nm, the difference between the maximum wavelength exhibiting 1% transmittance and the minimum wavelength exhibiting 1% transmittance is 90 nm or more. (β) IR cutoff wavelength λ IR CF and UV cutoff wavelength λ UV CF The difference between them is 180 nm or more. (γ) In the wavelength range of 700 nm to 1200 nm, the difference between the maximum wavelength exhibiting 1% transmittance and the minimum wavelength exhibiting 1% transmittance is 200 nm or more.

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