Oxocarbon compound

Abstract

Provided is an oxocarbon compound represented by formula (1) or formula (2). In formula (3), ring A represents a 10- to 18-membered unsaturated hydrocarbon ring, ring B represents an aromatic hydrocarbon ring, an aromatic heterocyclic ring, or a condensed ring including the ring structure of these rings, ring A and ring B may have a substituent, X represents an alkyl group, an aryl group, or an aralkyl group, and * represents a bonding site with the 4-membered ring in formula (1) or the 5-membered ring in formula (2).

Description

Oxocarbon compounds

[0001] This disclosure relates to oxocarbon compounds and compositions containing them, resin compositions, molded articles formed from said resin compositions, and optical filters.

[0002] Oxocarbon compounds are useful as dyes having an absorption region in the red to near-infrared range, and the applicant has filed patent applications for various oxocarbon compounds to date. For example, Patent Documents 1 to 4 disclose oxocarbon compounds having a structure in which pyrrole rings are bonded to both sides of a cyclic oxocarbon skeleton via carbon atoms.

[0003] Japanese Patent Publication No. 2016-074649, Japanese Patent Publication No. 2017-067963, International Publication No. 2017 / 146187, Japanese Patent Publication No. 2018-095798

[0004] Oxocarbon compounds are expected to be used in near-infrared light cut filters, near-infrared absorbing films, security inks, and other applications, taking advantage of their absorption range in the red to near-infrared region. For example, near-infrared cut filters can be installed on image sensors such as CCDs (Charge Coupled Devices) and CMOSs ​​(Complementary Metal-Oxide Semiconductors) to remove optical noise (such as ghosting and flare) that interferes with image processing.

[0005] Oxocarbon compounds can have their absorption wavelength lengthened by expanding the intramolecular π-electron system, thereby achieving a relatively large extension of the absorption wavelength. On the other hand, the absorption wavelength of oxocarbon compounds can also be adjusted by changing the substituents connected to the π-electron system, in which case the absorption wavelength can be adjusted relatively finely. It is desirable for oxocarbon compounds to be able to arbitrarily adjust the absorption wavelength depending on the application, and if the absorption wavelength can be adjusted by methods other than changing the number of electrons in the π-electron system or changing substituents, it is expected that this will lead to an improvement in the practicality and ease of manufacture of oxocarbon compounds. The problem to be solved by this disclosure is to provide an oxocarbon compound that can have its absorption wavelength lengthened by methods other than changing the number of electrons in the π-electron system or changing substituents.

[0006] The oxocarbon compounds relating to this disclosure that can solve the aforementioned problems are as follows: [1] An oxocarbon compound represented by the following formula (1) or formula (2). [In equations (1) and (2), R １ ~R ４ Each of these independently represents a structural unit shown in formula (3) below. [In formula (3), ring A represents an optionally substituted 10-18 member unsaturated hydrocarbon ring; ring B represents an optionally substituted aromatic hydrocarbon ring, an optionally substituted aromatic heterocycle, or an optionally substituted fused ring containing these ring structures; X represents an alkyl group, an aryl group, or an aralkyl group; * represents a bonding site with the 4-membered ring in formula (1) or the 5-membered ring in formula (2).] [2] The oxocarbon compound according to [1], wherein ring B is an optionally substituted benzene ring or naphthalene ring. [3] The oxocarbon compound according to [1] or [2], wherein the oxocarbon compound is a squarylium compound represented by formula (1).

[0007] The present disclosure also provides a composition containing an oxocarbon compound of the present disclosure, a resin composition, a molded body formed from the resin composition, and an optical filter having a resin layer formed from the resin composition. [4] A composition containing the oxocarbon compound according to any one of [1] to [3]. [5] A resin composition containing the oxocarbon compound according to any one of [1] to [3] and a resin component. [6] The resin composition according to [5], further containing a solvent. [7] A molded body formed from the resin composition according to [5] or [6]. [8] An optical filter having a resin layer formed from the resin composition according to any one of [5] to [7].

[0008] In the oxocarbon compound according to the present disclosure, by setting the number of ring members of the unsaturated hydrocarbon ring of ring A to 10 to 18 members, it is possible to shift the absorption wavelength to a longer wavelength as compared with the case of a smaller number of ring members.

[0009] Represents the absorption spectrum of squarylium compound 1 in the examples. Represents the transmittance spectrum of the optical filter produced in the examples.

[0010] The oxocarbon compound according to the present disclosure is a squarylium compound represented by the following formula (1) and a croconium compound represented by the following formula (2). In the following formula (1) and formula (2), R １ to R ４ each independently represents a structural unit represented by the following formula (3).

[0011]

[0012]

[0013] In formula (3), ring A represents a 10- to 18-member unsaturated hydrocarbon ring which may have a substituent, ring B represents an aromatic hydrocarbon ring which may have a substituent, an aromatic heterocyclic ring which may have a substituent, or a condensed ring which may have a substituent and contains these ring structures, X represents an alkyl group, an aryl group or an aralkyl group, and * represents the bonding site with the 4-member ring in formula (1) or the 5-member ring in formula (2).

[0014] Oxocarbon compounds are compounds containing a cyclic oxocarbon skeleton composed of carbon and oxygen atoms, and due to their structure, they have an absorption band around 600 nm to 1500 nm. Therefore, they can be used as near-infrared absorbing dyes, under the name or classification of oxocarbon dyes. In the oxocarbon compounds of this disclosure, by setting the number of ring members of the unsaturated hydrocarbon ring A to 10 to 18, the absorption wavelength can be extended to longer wavelengths compared to cases with fewer ring members.

[0015] Examples of oxocarbon skeletons include the squarylium skeleton represented by formula (1) and the crokonium skeleton represented by formula (2). In the oxocarbon compounds of this disclosure, the group represented by formula (3) is bonded to the squarylium skeleton or the crokonium skeleton. The group bonded to the squarylium skeleton or the crokonium skeleton in the oxocarbon compounds may contain atoms other than carbon and oxygen atoms, and in formula (3), it contains a nitrogen atom. The group represented by formula (3) may contain other atoms depending on the substituents.

[0016] Oxocarbon compounds may contain compounds that are in resonance with them. Examples of compounds that are in resonance with the squarylium compound of formula (1) include the compounds represented by formulas (1a) and (1b) below. Examples of compounds that are in resonance with the crokonium compound of formula (2) include the compounds represented by formulas (2a) to (2c) below. The squarylium compound represented by formula (1) and the crokonium compound represented by formula (2) include compounds that are in resonance with them.

[0017]

[0018]

[0019] In the squarylium compound of formula (1), R １ and R ２ These may be the same or different. The squarylium compound of formula (1) is specifically represented by the following formula (1A). In the croconium compound of formula (2), R ３ and R ４They may be the same or different. The croconium compound of formula (2) is specifically represented by the following formula (2A).

[0020]

[0021]

[0022] In the above formula (1A) and formula (2A), ring A １ and ring A ２ may be the same or different, ring B １ and ring B ２ may be the same or different, and X １ and X ２ may be the same or different. The description of ring A １ and ring A ２ refers to the description of ring A, and the description of ring B １ and ring B ２ refers to the description of ring B, and the description of X １ and X ２ refers to the description of X.

[0023] In formula (3), ring A represents an unsaturated hydrocarbon ring having 10 to 18 ring members, and a substituent may be bonded to the unsaturated hydrocarbon ring. Ring A has a double bond between the carbon atom bonded to the squarylium skeleton or croconium skeleton and the α-position carbon atom of the pyrrole ring, and is an unsaturated hydrocarbon ring composed of the α-position carbon and β-position carbon of the pyrrole ring. Ring A may have an unsaturated bond (preferably a double bond) other than the above double bond, and preferably has only one unsaturated bond (double bond). Ring A may have 11 or more or 12 or more members, and may also have 17 or less, 16 or less or 15 or less members.

[0024] By having ring A, the oxocarbon-based compound promotes the association between molecules, and as a result, it becomes possible to reduce the shoulder peak on the short wavelength side of the absorption peak having a maximum absorption in the red to near infrared region, and the optical properties can be improved. Further, if the oxocarbon-based compound has ring A, due to molecular strain, π-π ＊Because the transition band gap is narrowed and the π-electron system can be broadened over a wide area by ring B, it is possible to achieve longer absorption wavelengths.

[0025] Examples of ring A structures include cycloalkene structures such as cyclodecene, cycloundecene, cyclododecene, cyclotridecene, cyclotetradecene, cyclopentadecene, cyclohexadecene, cycloheptadecene, cyclooctadecene, cyclodecadien, cyclododecadien, cyclododecatriene, and cyclopentadecadiene. Among these, cycloalkane monoenes such as cyclodecene, cyclododecene, and cyclopentadecene are preferred.

[0026] Ring A has a substituent (hereinafter referred to as "substituent R") ａ It may have a substituent R (referred to as "), ａ Examples include organic groups and polar functional groups. In the following formula (3A), the structural unit of formula (3) has a substituent R on ring A. ａ The substituent R, described later, is bonded to ring B. ｂ The structural formula showing the combined structure is shown.

[0027]

[0028] Substituent R ａ Examples of organic groups include alkyl groups, alkoxy groups, alkylthio groups, alkoxycarbonyl groups, alkylsulfonyl groups, alkylsulfinyl groups, aryl groups, aralkyl groups, aryloxy groups, arylthio groups, aryloxycarbonyl groups, arylsulfonyl groups, arylsulfinyl groups, heteroaryl groups, amino groups, amide groups, sulfonamide groups, carboxyl groups (carboxylic acid groups), cyano groups, etc. Substituent R ａ Examples of polar functional groups include halogen groups, hydroxyl groups, nitro groups, and sulfo groups (sulfonic acid groups).

[0029] Substituent R ａExamples of alkyl groups include linear or branched alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, and eicosyl groups; and cyclic (alicyclic) alkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, and cyclodecyl groups. Alkyl groups may have substituents, and examples of substituents on alkyl groups include aryl, heteroaryl, halogeno, hydroxyl, carboxyl, alkoxy, cyano, nitro, amino, and sulfo groups. Examples of alkyl groups having a halogen group include monohalogenoalkyl groups, dihalogenoalkyl groups, alkyl groups having a trihalomethyl unit, and perhalogenoalkyl groups. Preferred halogen groups are fluorine atoms, chlorine atoms, and bromine atoms, with fluorine atoms being particularly preferred. The number of carbon atoms (excluding substituents) of the alkyl group is preferably 1 to 20. Specifically, for linear or branched alkyl groups, the number of carbon atoms is preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 5. For cyclic alkyl groups (alicyclic alkyl groups), the number of carbon atoms is preferably 4 to 10, and more preferably 5 to 8.

[0030] Substituent R ａ For specific examples of alkyl groups included in the alkoxy group, alkylthio group, alkoxycarbonyl group, alkylsulfonyl group, and alkylsulfinyl group, please refer to the explanation of alkyl groups above.

[0031] Substituent R ａExamples of aryl groups include phenyl, biphenyl, naphthyl, anthryl, phenanthryl, pyrenyl, and indenyl groups. The aryl group may have substituents, and examples of substituents on the aryl group include alkyl, alkoxy, heteroaryl, halogeno, halogenoalkyl, hydroxyl, cyano, nitro, amino, thiocyanate, acyl, alkoxycarbonyl, aryloxycarbonyl, carbamoyl, sulfo, alkylsulfinyl, arylsulfinyl, alkylsulfonyl, arylsulfonyl, and sulfamoyl groups. The number of carbon atoms in the aryl group (excluding substituents) is preferably 6 to 20, and more preferably 6 to 12.

[0032] Substituent R ａ Examples of aralkyl groups include benzyl group, phenylethyl group, phenylpropyl group, phenylbutyl group, phenylpentyl group, naphthylmethyl group, etc. Aralkyl groups may have substituents, and examples of substituents on aralkyl groups include alkyl groups, alkoxy groups, halogeno groups, halogenoalkyl groups, cyano groups, nitro groups, thiocyanate groups, acyl groups, alkoxycarbonyl groups, aryloxycarbonyl groups, carbamoyl groups, sulfo groups, alkylsulfinyl groups, arylsulfinyl groups, alkylsulfonyl groups, arylsulfonyl groups, sulfamoyl groups, etc. The number of carbon atoms in the aralkyl group (number of carbon atoms excluding substituents) is preferably 7 to 25, and more preferably 7 to 15.

[0033] Substituent R ａ For specific examples of aryl groups included in the aryloxy, arylthio, aryloxycarbonyl, arylsulfonyl, and arylsulfinyl groups, please refer to the explanation of aryl groups above.

[0034] Substituent R ａExamples of heteroaryl groups include thienyl group, thiopyranyl group, isothioclomenyl group, pyrrolyl group, imidazolyl group, pyrazolyl group, pyridyl group, pyraridinyl group, pyrimidinyl group, pyridadinyl group, thiazolyl group, isothiazolyl group, furanyl group, and pyranyl group. Heteroaryl groups may have substituents, and examples of substituents on heteroaryl groups include alkyl groups, alkoxy groups, aryl groups, halogeno groups, halogenoalkyl groups, hydroxyl groups, cyano groups, amino groups, nitro groups, thiocyanate groups, acyl groups, alkoxycarbonyl groups, aryloxycarbonyl groups, carbamoyl groups, sulfo groups, alkylsulfinyl groups, arylsulfinyl groups, alkylsulfonyl groups, arylsulfonyl groups, and sulfamoyl groups. The number of carbon atoms (excluding substituents) of the heteroaryl group is preferably 2 to 20, and more preferably 3 to 15.

[0035] Substituent R ａ The amino group is given by formula: -NR ｃ１ R ｃ２ It is represented as R ｃ１ and R ｃ２ Examples include groups in which each element is independently a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group, or a heteroaryl group. Specific examples of alkyl groups, aryl groups, aralkyl groups, and heteroaryl groups are given in the descriptions of these groups above. Alkenyl groups and alkynyl groups include groups in which some of the carbon-carbon single bonds of the alkyl groups exemplified above are replaced by double or triple bonds. ｃ１ and R ｃ２ They may be connected to each other to form a ring.

[0036] Substituent R ａ The amide group is given by formula: -NH-C(=O)-R ｃ３ It is represented as R ｃ３ Examples include alkyl groups, aryl groups, aralkyl groups, and heteroaryl groups. For specific examples of alkyl groups, aryl groups, aralkyl groups, and heteroaryl groups, please refer to the descriptions of these groups above.

[0037] Substituent R ａThe sulfonamide group is of the formula: -NH-SO ２ -R ｃ４ It is represented as R ｃ４ Examples include alkyl groups, aryl groups, aralkyl groups, and heteroaryl groups. For specific examples of alkyl groups, aryl groups, aralkyl groups, and heteroaryl groups, please refer to the descriptions of these groups above.

[0038] Substituent R ａ Examples of halogen groups include fluoro groups, chloro groups, bromo groups, and iodine groups.

[0039] Ring A has multiple substituents R ａ It has a plurality of substituents R ａ These may be linked to each other to form a ring. In this case, there may be multiple substituents R ａ It is preferable that the substituents R are bonded to adjacent carbon atoms among the carbon atoms constituting ring A, and such multiple substituents R are bonded to adjacent carbon atoms. ａ It is preferable that they are connected to each other to form a ring.

[0040] Multiple substituents R ａExamples of ring structures formed by the linkage of these elements include hydrocarbon rings and heterocycles. These ring structures may or may not be aromatic, but it is preferable that they be non-aromatic hydrocarbon rings or non-aromatic heterocycles. Examples of non-aromatic hydrocarbon rings include cycloalkanes such as cyclopentane, cyclohexane, and cycloheptane; and cycloalkenes such as cyclopentene, cyclohexene, cyclohexadiene (e.g., 1,3-cyclohexadiene), cycloheptene, and cycloheptadiene. Examples of non-aromatic heterocycles include rings in which one or more carbon atoms constituting the non-aromatic hydrocarbon ring described above are replaced by at least one atom selected from N (nitrogen atom), S (sulfur atom), and O (oxygen atom). Examples of non-aromatic heterocycles include pyrrolidine rings, tetrahydrofuran rings, tetrahydrothiophene rings, piperidine rings, tetrahydropyran rings, tetrahydrothiopyran rings, morpholine rings, dioxane rings, dithiane rings, piperazine rings, thiomorpholine rings, dioxin rings, triazine rings, hexamethyleneimine rings, hexamethylene oxide rings, hexamethylene sulfide rings, and heptamethyleneimine rings.

[0041] Substituent R bonded to ring A ａ The number of substituents is preferably less than or equal to the number of members of ring A minus 3. ａ If it has multiple substituents R, the number is preferably 1 to 6, more preferably 1 to 3, and even more preferably 1 to 2. ａ If it has multiple substituents R ａ They may be the same or different, and multiple substituents R ａ Each atom may be bonded to a different carbon atom, or it may be bonded to a single carbon atom. Ring A may not have substituents.

[0042] A substituent X, consisting of an alkyl group, an aryl group, or an aralkyl group, is bonded to the carbon atom at the β position of the pyrrole ring that constitutes part of ring A. Details of the alkyl group, aryl group, and aralkyl group of X are shown above for substituent R. ａSee the explanation of alkyl groups, aryl groups, and aralkyl groups for X. The number of carbon atoms in the alkyl group of X is preferably 1 to 6, more preferably 1 to 4, if it is a linear or branched alkyl group, and preferably 4 to 7, more preferably 5 to 6, if it is a cyclic alkyl group. Linear or branched alkyl groups are more preferred for the alkyl group of X. The number of carbon atoms in the aryl group of X is preferably 6 to 12, more preferably 6 to 10. The number of carbon atoms in the aralkyl group of X is preferably 7 to 15, more preferably 7 to 13. Examples of alkyl groups, aryl groups, and aralkyl groups of X include methyl group, ethyl group, isopropyl group, isobutyl group, t-butyl group, cyclopentyl group, cyclohexyl group, phenyl group, benzyl group, phenylethyl group, etc. At least some of the hydrogen atoms in the alkyl group, aryl group, and aralkyl group of X may be replaced by halogen atoms (especially fluorine atoms).

[0043] In formula (3), ring B represents an aromatic hydrocarbon ring, an aromatic heterocycle, or a fused ring containing these ring structures, and these rings may have substituents. By having ring B, the oxocarbon compound has a π-electron system that extends over a wide range from the squarylium or crokonium skeleton to ring B via the pyrrole ring, enabling the absorption wavelength to be extended to longer wavelengths. By appropriately setting the π-conjugated system of ring B, the absorption wavelength of the oxocarbon compound can be easily adjusted. In the short wavelength range, the absorption maximum wavelength can be adjusted to, for example, about 650 nm, and by increasing the number of π electrons of ring B (expanding the π-conjugated system), the maximum absorption wavelength can be shifted to longer wavelengths, for example, the absorption maximum wavelength can be adjusted to about 1100 nm.

[0044] Examples of aromatic hydrocarbon rings in ring B include those having 6 to 14 carbon atoms, such as benzene rings, naphthalene rings, phenanthrene rings, anthracene rings, fluorantene rings, and cyclotetradecaheptaene rings. The aromatic hydrocarbon ring may have only one ring structure, or it may be a condensed ring structure of two or more ring structures.

[0045] Examples of aromatic heterocycles of ring B include five- or six-membered monocyclic aromatic heterocycles containing at least one atom selected from nitrogen, oxygen, and sulfur atoms, and fused aromatic heterocycles of three to eight members formed by the fusion of three- to eight-membered rings and containing at least one atom selected from nitrogen, oxygen, and sulfur atoms. Specifically, examples include furan rings, thiophene rings, pyrrole rings, pyrazole rings, oxazole rings, thiazole rings, imidazole rings, pyridine rings, pyridazine rings, pyrimidine rings, pyrazine rings, purine rings, and pteridine rings. The aromatic heterocycle may have only one ring structure, or it may be formed by the fusion of two or more ring structures.

[0046] The fused ring of ring B, which includes an aromatic hydrocarbon ring and an aromatic heterocycle, has a structure in which the aromatic hydrocarbon ring and the aromatic heterocycle are fused together. Examples include indole rings, isoindole rings, benzimidazole rings, quinoline rings, isoquinoline rings, acridine rings, xanthene rings, and carbazole rings.

[0047] Ring B is a substituent (hereinafter referred to as "substituent R") ｂ It may have a substituent R (referred to as "), ｂ Examples include the organic groups and polar functional groups described above. Ring B consists of multiple substituents R ｂ It has a plurality of substituents R ｂ These may be linked to each other to form a ring. In this case, there may be multiple substituents R ｂ Preferably, the substituents R are bonded to adjacent atoms among the constituent atoms of ring B, and such multiple substituents R bonded to adjacent atoms are formed. ｂ It is preferable that the multiple substituents R are linked to each other to form a ring. ｂ Details of the ring structure formed from the above-mentioned multiple substituents R ａ A description of the ring structure formed from is referenced. Ring B is substituent R ｂ If ring B has substituents, its number is preferably 1 to 3, and more preferably 1 to 2. Ring B may not have substituents.

[0048] Oxocarbon compounds preferably have an absorption maximum at a wavelength of 720 nm or higher in the absorption spectrum measured in chloroform, more preferably at a wavelength of 725 nm or higher, and even more preferably at a wavelength of 730 nm or higher. Specifically, in the absorption spectrum measured in chloroform in the wavelength range of 300 nm to 1100 nm, it is preferable to have an absorption maximum at a wavelength of 720 nm or higher (more preferably at a wavelength of 725 nm or higher, and even more preferably at a wavelength of 730 nm or higher). Furthermore, it is preferable to have a peak with an absorption maximum at a wavelength of 720 nm or higher (more preferably at a wavelength of 725 nm or higher, and even more preferably at a wavelength of 730 nm or higher), and for the absorption maximum of this absorption peak to take its maximum value in the wavelength range of 300 nm to 1100 nm. The wavelength of the absorption maximum is referred to as the absorption maximum wavelength λmax. If an oxocarbon compound exhibits such an absorption spectrum, it can effectively absorb light in the red to near-infrared region. The absorption maximum wavelength λmax is more preferably 900 nm or less, even more preferably 850 nm or less, and even more preferably 800 nm or less.

[0049] The absorption spectrum is determined by measuring absorbance at 1 nm intervals in the wavelength range of 300 nm to 1100 nm. The concentration of the oxocarbon compound in chloroform is adjusted so that the maximum absorbance (maximum absorbance at the maximum absorption peak) in the wavelength range of 300 nm to 1100 nm is 1 ± 0.005. In this disclosure, when the absorption spectrum is measured under these conditions, it is assumed that the absorbance at the absorption maximum wavelength of the maximum absorption peak is 1.

[0050] In the absorption spectrum measured in chloroform, the oxocarbon compound preferably has a ratio A = Abs(450) / Abs(750) × 100 between the absorbance at wavelength 450 nm (Abs(450)) and the absorbance at wavelength 750 nm (Abs(750)) when the absorbance at the absorption maximum wavelength λmax of the maximum absorption peak is set to 1.0%, more preferably 1.8% or less, particularly preferably 1.5% or less, and most preferably 1.0% or less. This allows for increased light transmittance in the visible light region.

[0051] As an oxocarbon compound exhibiting the absorption spectrum described above, squarylium compounds are preferred. If the oxocarbon compound is a squarylium compound, it can effectively absorb light near the boundary between the red and near-infrared regions, and it is easy to increase the transmittance of light in the visible light region.

[0052] The Disclosure also provides compositions comprising an oxocarbon compound represented by formula (1) or formula (2) above. The oxocarbon compound of the Disclosure contained in the composition may be one or more. The two or more oxocarbon compounds may be structural isomers of each other.

[0053] A composition containing an oxocarbon compound may also contain other dyes along with the oxocarbon compound of this disclosure, for example, at least one selected from near-infrared absorbing dyes, visible light absorbing dyes, and ultraviolet absorbing dyes. Details of near-infrared absorbing dyes, visible light absorbing dyes, and ultraviolet absorbing dyes are described later in the description of near-infrared absorbing dyes, visible light absorbing dyes, and ultraviolet absorbing dyes that may be included in resin compositions.

[0054] Examples of compositions containing oxocarbon compounds include oxocarbon compound solutions containing an oxocarbon compound and a solvent. The solvent is preferably an organic solvent, which allows for the production of an oxocarbon compound solution containing a high concentration of the oxocarbon compound. The oxocarbon compound solution can be applied to, for example, security inks and can be used as an ink composition.

[0055] Solvents used in oxocarbon compound solutions include ketones such as methyl ethyl ketone (dipole moment: 2.76 D), methyl isobutyl ketone (dipole moment: 2.56 D), cyclopentanone, and cyclohexanone (dipole moment: 3.01 D); glycol derivatives such as PGMEA (2-acetoxy-1-methoxypropane), ethylene glycol mono-n-butyl ether (dipole moment: 2.08 D), ethylene glycol monoethyl ether (dipole moment: 2.08 D), and ethylene glycol ethyl ether acetate (e.g., ether compounds, ester compounds, ether ester compounds, etc.); amides such as N,N-dimethylacetamide (dipole moment: 3.72 D); ethyl acetate, and propyl acetate. Examples include esters such as butyl acetate; pyrrolidones such as N-methylpyrrolidone (dipole moment: 4.08 D); aromatic hydrocarbons such as benzene (dipole moment: 0 D), toluene (dipole moment: 0.37 D), and xylene (dipole moment: 0-0.44 D); aliphatic hydrocarbons such as cyclohexane and heptane (dipole moment: 0 D); ethers such as tetrahydrofuran (dipole moment: 1.70 D), dioxane, diethyl ether (dipole moment: 1.12 D), and dibutyl ether (dipole moment: 1.22 D); alcohols such as methanol, ethanol, and isopropanol; and halogen-containing aromatic hydrocarbons such as chlorobenzene and o-dichlorobenzene (dipole moment: 2.27 D). These solvents may be used individually or in combination of two or more. Oxocarbon compounds have high durability against solvents with small dipole moments. Therefore, solvents with a dipole moment of 4.0 D or less are preferred, solvents with a dipole moment of 3.5 D or less are more preferred, and solvents with a dipole moment of 3.0 D or less are even more preferred. Specific examples of such solvents include, for example, o-dichlorobenzene, cyclopentanone, PGMEA, ethylcyclohexane, xylene, toluene, trimethylbenzene, and limonene. Among these, ketones, glycol derivatives, aliphatic hydrocarbons, aromatic hydrocarbons, and halogenated aromatic hydrocarbons are preferred.

[0056] The amount of solvent used can be appropriately set according to the desired concentration of the oxocarbon compound in the oxocarbon compound solution. The concentration of the oxocarbon compound in the oxocarbon compound solution can be appropriately set in the range of, for example, 0.01 to 10% by mass, and this concentration may be 0.05% by mass or more, 0.1% by mass or more, or 0.2% by mass or more, or 5% by mass or less, 3% by mass or less, or 2% by mass or less.

[0057] A composition containing an oxocarbon compound may also be a resin composition containing an oxocarbon compound and a resin component. The resin composition contains at least the oxocarbon compound and resin component of this disclosure. The resin composition can be suitably applied to optical filters by forming a resin molded article, such as a film. Since the oxocarbon compound of this disclosure can function as a near-infrared absorbing dye, an optical filter formed from the resin composition of this disclosure can be applied to a near-infrared cut filter. The resin molded article can also be applied to near-infrared absorbing films and near-infrared absorbing plates that block heat rays for energy saving, materials for solar cells that utilize visible light and near-infrared light, and specific wavelength absorbing filters for plasma display panels (PDPs) and CCDs.

[0058] The oxocarbon compounds of this disclosure contained in the resin composition may be one or more. The resin composition may also contain other dyes along with the oxocarbon compounds of this disclosure, as long as the desired performance according to the application is ensured, for example, it may contain at least one selected from near-infrared absorbing dyes, visible light absorbing dyes, and ultraviolet absorbing dyes.

[0059] If the resin composition further contains a near-infrared absorbing dye and / or a visible light absorbing dye, an optical filter having light selective transmission can be obtained from the resin composition. For example, if the resin composition contains the oxocarbon compound of this disclosure and a near-infrared absorbing dye, it can be used as a resin composition for an optical filter that suppresses the transmission of light in a wide range from red to near-infrared and preferentially transmits light in the visible light region. If the resin composition contains the oxocarbon compound of this disclosure and a visible light absorbing dye, it can be used as a resin composition for colored filters or blue light reduction filters, etc.

[0060] The near-infrared absorbing dye is preferably one that has an absorption maximum in the wavelength range of 600 nm to 1100 nm. More preferably, the near-infrared dye has a peak with an absorption maximum in the wavelength range of 600 nm to 1100 nm in its absorption spectrum in the wavelength range of 450 nm to 1100 nm, and the absorption maximum of the absorption peak takes its maximum value in the wavelength range of 450 nm to 1100 nm. The wavelength of the absorption maximum is more preferably 630 nm or higher, even more preferably 660 nm or higher, even more preferably 1000 nm or lower, even more preferably 900 nm or lower, and even more preferably 800 nm or lower.

[0061] The visible light absorbing dye can be used without particular limitations as long as it has the maximum absorption peak wavelength in the visible light region (for example, in the range of wavelengths greater than 420 nm and less than 680 nm). In particular, it is preferable to use a visible light absorbing dye that has the maximum absorption peak wavelength in the range of wavelengths greater than 500 nm and less than 680 nm, where luminous sensitivity is high.

[0062] Near-infrared absorbing dyes and visible light absorbing dyes are not particularly limited in that they are organic dyes, inorganic dyes, or organic-inorganic composite dyes (for example, organic compounds coordinated with metal atoms or ions). Examples of near-infrared absorbing dyes and visible light absorbing dyes include squarylium-based dyes other than the oxocarbon-based compounds of this disclosure, crokonium-based dyes other than the oxocarbon-based compounds of this disclosure, cyclic tetrapyrrole-based dyes (e.g., porphyrins, chlorines, phthalocyanines, naphthalocyanines, cholines, etc.) which may have copper (e.g., Cu(II)) or zinc (e.g., Zn(II)) as a central metal ion, cyanine-based dyes, azo-based dyes, quinone-based dyes, xanthene-based dyes, indoline-based dyes, arylmethane-based dyes, quaterylene-based dyes, diimonium-based dyes, perylene-based dyes, quinacridone-based dyes, oxazine-based dyes, dipyromethene-based dyes, nickel complex-based dyes, copper ion-based dyes, etc. These dyes may be used individually or in combination of two or more. In particular, as near-infrared absorbing dyes and visible light absorbing dyes, it is preferable to use at least one selected from squarylium-based dyes other than the oxocarbon-based compounds of this disclosure, crokonium-based dyes other than the oxocarbon-based compounds of this disclosure, phthalocyanine-based dyes, cyanine-based dyes, and dipyromethene-based dyes, since they can effectively absorb light of a desired wavelength. As a near-infrared absorbing dye, it is preferable to use at least one selected from squarylium-based dyes other than the squarylium-based compounds of this disclosure, crokonium-based dyes other than the oxocarbon-based compounds of this disclosure, phthalocyanine-based dyes, and cyanine-based dyes. This makes it easier to effectively absorb light in the near-infrared region and increase visible light transmittance. For example, the squarylium-based compounds and crokonium-based compounds described in Japanese Patent Application Publication No. 2016-074649 can be used.

[0063] The resin composition may contain an ultraviolet-absorbing dye. Preferably, the ultraviolet-absorbing dye has a maximum absorption in the range of 300 nm to 400 nm. By containing an ultraviolet-absorbing dye in the resin composition, an optical filter with selective light transmission that suppresses the transmission of light in the ultraviolet to violet region can be obtained from the resin composition. Furthermore, degradation of the resin composition caused by light in the ultraviolet to violet region can be suppressed, and even when the resin composition is exposed to ultraviolet light during storage or during the manufacturing and processing of the optical filter (e.g., vapor deposition or mounting), the degradation of the resin component and other components such as oxocarbon compounds contained in the resin composition can be suppressed from such ultraviolet light.

[0064] As ultraviolet absorbing dyes, known ultraviolet absorbers such as benzotriazole compounds, benzophenone compounds, salicylic acid compounds, benzoxazinon compounds, cyanoacrylate compounds, benzoxazole compounds, merocyanine compounds, and triazine compounds can be used. Only one ultraviolet absorbing dye may be used, or two or more may be used. Commercially available substances may be used as ultraviolet absorbing dyes (ultraviolet absorbers), for example, the ADEKA Stab® series from ADEKA Corporation, the TINUVIN® series from BASF Corporation, the DISLISER® series from Sankyo Chemicals Co., Ltd., the Sumisorb® series from Sumitomo Chemical Co., Ltd., the Biosorb® series from Kyodo Pharmaceutical Co., Ltd., and the Seesorb® series from Cipro Chemical Co., Ltd. can be used. In addition, ethylene compounds disclosed in Japanese Patent Publication No. 2019-014707 and Japanese Patent Publication No. 2022-158995 can also be used as ultraviolet absorbing dyes.

[0065] The content of oxocarbon compounds in the resin composition is preferably 0.01% by mass or more, more preferably 0.03% by mass or more, and even more preferably 0.1% by mass or more, based on 100% by mass of the solid content of the resin composition, in order to achieve the desired performance. Furthermore, in order to improve the moldability and film-forming properties of the resin composition, the content of oxocarbon compounds in the resin composition is preferably 25% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less, based on 100% by mass of the solid content of the resin composition. If the resin composition also contains other dyes, it is preferable that the total content of these dyes is within the above range. Note that the solid content of the resin composition refers to the amount of resin composition excluding the solvent, if the resin composition contains a solvent.

[0066] The resin component included in the resin composition can be any known resin. Preferably, the resin component is highly transparent and capable of dissolving the oxocarbon-based compound of this disclosure. If other dyes are used in combination, the resin component is preferably capable of dissolving those dyes as well. By selecting such a resin component, it is possible to achieve both high transmittance in the wavelength range to be transmitted and high absorption in the wavelength range to be blocked.

[0067] As resin components, not only resins whose polymerization is complete, but also resin raw materials (including resin precursors, raw materials for said precursors, monomers constituting the resin, etc.) that are incorporated into the resin through polymerization or crosslinking reactions when molding the resin composition can be used. In this disclosure, all resins are included as resin components. In the latter case, however, some or all of the structure of the oxocarbon compound may decompose due to unreacted substances, reactive terminal functional groups, ionic groups, catalysts, acidic / basic groups, etc., present in the reaction solution obtained from the polymerization reaction. Therefore, if such concerns exist, it is desirable to form the resin composition by blending the oxocarbon compound with a resin whose polymerization is complete.

[0068] As the resin component, known resins can be used, and it is preferable to use a resin with high transparency. The resin component may be a thermoplastic resin or a thermosetting resin. Examples of resin components include (meth)acrylic resins, (meth)acrylic urethane resins, polyvinyl chloride resins, polyvinylidene chloride resins, polyolefin resins (e.g., polyethylene resins, polypropylene resins), cycloolefin resins, melamine resins, urethane resins, styrene resins, polyvinyl acetate, polyamide resins (e.g., nylon), aramid resins, polyimide resins, polyamide-imide resins, alkyd resins, phenolic resins, epoxy resins, polyester resins (e.g., polybutylene terephthalate (PBT) resins, polyethylene terephthalate (PET) resins, polyarylate resins, etc.), polysulfone resins, butyral resins, polycarbonate resins, and poly Examples of these resins include ether resins, ABS resins (acrylonitrile butadiene styrene resins), AS resins (acrylonitrile-styrene copolymers), silicone resins, modified silicone resins (e.g., (meth)acrylic silicone resins, alkylpolysiloxane resins, silicone urethane resins, silicone polyester resins, silicone acrylic resins, etc.), and fluororesins (e.g., fluorinated aromatic polymers, polytetrafluoroethylene (PTFE), perfluoroalkoxy fluororesins (PFA), fluorinated polyaryl ether ketones (FPEK), fluorinated polyimide (FPI), fluorinated polyamic acid (FPAA), fluorinated polyethernitrile (FPEN), etc.). Among these, (meth)acrylic resins, cycloolefin resins, polyimide resins, polyamide-imide resins, polyester resins, polyarylate resins, polyamide resins, polycarbonate resins, epoxy resins, polysulfone resins, and fluorinated aromatic polymers are preferred due to their excellent transparency and heat resistance.

[0069] (Meth)acrylic resins are polymers having repeating units derived from (meth)acrylic acid or its derivatives. For example, resins having repeating units derived from (meth)acrylic acid esters, such as poly(meth)acrylic acid ester resins, are preferably used. (Meth)acrylic resins with a ring structure in the main chain are also preferred. Examples include carbonyl group-containing ring structures such as lactone ring structures, glutaric acid anhydride structures, glutarimide structures, maleic acid anhydride structures, and maleimide ring structures; and carbonyl group-free ring structures such as oxetane ring structures, azetidine ring structures, tetrahydrofuran ring structures, pyrrolidine ring structures, tetrahydropyran ring structures, and piperidine ring structures. Note that carbonyl group-containing ring structures also include structures containing carbonyl group derivative groups such as imide groups. (Meth)acrylic resins having a carbonyl group-containing ring structure can be those described in, for example, Japanese Patent Publication No. 2004-168882, Japanese Patent Publication No. 2008-179677, International Publication No. 2005 / 54311, Japanese Patent Publication No. 2007-31537, etc.

[0070] Cycloolefin resins are polymers obtained by polymerizing cycloolefins as at least a portion of their monomer components, and are not particularly limited as long as they have an alicyclic structure in part of their main chain. Examples of cycloolefin resins that can be used include Topas® manufactured by Polyplastics Corporation, Appel® manufactured by Mitsui Chemicals Corporation, Zeonex® and Zeonor® manufactured by Nippon Zeon Corporation, and Arton® manufactured by JSR Corporation.

[0071] Polyimide resins are polymers that contain imide bonds in the repeating units of their main chain. For example, they can be produced by polymerizing tetracarboxylic acid 2-anhydride and a diamine to obtain polyamic acid, which is then dehydrated and cyclized (imidized). As the polyimide resin, it is preferable to use aromatic polyimides in which aromatic rings are linked by imide bonds. Examples of polyimide resins that can be used include Kapton (registered trademark) from DuPont, Aurum (registered trademark) from Mitsui Chemicals, Meldin (registered trademark) from Saint-Gobain, and the TPS (registered trademark) TI3000 series from Toray Plastics Precision Co., Ltd.

[0072] Polyamide-imide resins are polymers that contain amide and imide bonds in the repeating units of their main chain. Examples of polyamide-imide resins that can be used include Tolon® manufactured by Solvay Advanced Polymers, Byromax® manufactured by Toyobo Co., Ltd., and TPS® TI5000 series manufactured by Toray Plastics Precision Co., Ltd.

[0073] Polyester resins are polymers that contain ester bonds in the repeating units of their main chain, and can be obtained, for example, by condensation polymerization of a polycarboxylic acid (dicarboxylic acid) and a polyalcohol (diol). Examples of polyester resins include polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate. For example, OKP series from Osaka Gas Chemical Co., Ltd., TRN series from Teijin Ltd., Theonex®, Lynite® from DuPont, Novapex® from Mitsubishi Chemical Corporation, Novaduran® from Mitsubishi Engineering Plastics Corporation, Lumirror® and Torecon® from Toray Industries, Inc. can be used.

[0074] Polyarylate resin is a polymer obtained by condensation polymerization of a divalent phenol compound and a dibasic acid (for example, an aromatic dicarboxylic acid such as phthalic acid), and has repeating units in its main chain that contain aromatic rings and ester bonds. Examples of polyarylate resins that can be used include Vectran® manufactured by Kuraray Co., Ltd. and U Polymer® manufactured by Unitika Corporation.

[0075] Polyamide resins are polymers that contain amide bonds in the repeating units of their main chain, and can be obtained, for example, by condensation polymerization of a diamine and a dicarboxylic acid. Polyamide resins may also have an aliphatic skeleton in their main chain, and nylon can be used as such an amide resin. Polyamide resins may also have an aromatic skeleton, and aramid resins are known as such polyamide resins. Aramid resins are preferred because they have excellent heat resistance and high mechanical strength, and for example, Twaron® and Conex® from Teijin Corporation, and Kevlar® and Nomex® from DuPont can be used.

[0076] Polycarbonate resin is a polymer that contains carbonate groups (-O-(C=O)-O-) in the repeating units of its main chain. Examples of polycarbonate resins that can be used include Panlite® manufactured by Teijin, Yupizeta® manufactured by Mitsubishi Gas Chemical Company, Yupiron®, Novalex®, and Zanter® manufactured by Mitsubishi Engineering Plastics Corporation, and SD Polyca® manufactured by Sumika Styron Polycarbonate Co., Ltd.

[0077] Epoxy resins are resins that can be cured by crosslinking epoxy compounds (prepolymers) in the presence of a curing agent or curing catalyst. Examples of epoxy compounds include aromatic epoxy compounds, aliphatic epoxy compounds, alicyclic epoxy compounds, and hydrogenated epoxy compounds. For example, fluorene epoxy (Ogusol® PG-100) manufactured by Osaka Gas Chemical Co., Ltd., bisphenol A type epoxy compounds (JER® 828EL) and hydrogenated bisphenol A type epoxy compounds (JER® YX8000) manufactured by Mitsubishi Chemical Corporation, and alicyclic liquid epoxy compounds (Celoxide® 2021P, EHPE-3150) manufactured by Daicel Corporation can be used.

[0078] Polysulfone resins consist of aromatic rings and sulfonyl groups (-SO ２It is a polymer having repeating units containing a (-) and an oxygen atom. Examples of polysulfone resins that can be used include Sumika Excel® PES3600P and PES4100P manufactured by Sumitomo Chemical Co., Ltd., and UDEL® P-1700 manufactured by Solvay Specialty Polymers, Ltd.

[0079] A fluorinated aromatic polymer is a polymer having repeating units comprising an aromatic ring having one or more fluorine atoms and at least one bond selected from the group consisting of ether bonds, ketone bonds, sulfone bonds, amide bonds, imide bonds, and ester bonds. Among these, it is preferable that the polymer must contain repeating units comprising an aromatic ring having one or more fluorine atoms and an ether bond. For example, a fluorinated aromatic polymer described in Japanese Patent Application Publication No. 2008-181121 can be used.

[0080] The resin preferably has high transparency, which makes it easier to suitably apply the resin composition to optical applications. The resin preferably has a total light transmittance of 75% or more at a thickness of 0.1 mm, more preferably 80% or more, and even more preferably 85% or more. The upper limit of the total light transmittance of the resin is not particularly limited; the total light transmittance may be 100% or less, but may also be, for example, 95% or less. The total light transmittance is measured in accordance with JIS K 7105.

[0081] The glass transition temperature (Tg) of the resin is not particularly limited, but it is preferably relatively high, as this can improve the heat resistance of the resin layer formed from the resin composition. The glass transition temperature of the resin is preferably 110°C or higher, more preferably 120°C or higher, and even more preferably 130°C or higher. The upper limit of the glass transition temperature of the resin is not particularly limited, but from the viewpoint of improving the moldability of the resin composition, it is preferably 380°C or lower.

[0082] The resin component preferably has high transparency, which makes it easier to suitably apply the resin composition to optical applications. The resin component preferably has a total light transmittance of 75% or more at a thickness of 0.1 mm, more preferably 80% or more, and even more preferably 85% or more. The upper limit of the total light transmittance of the resin component is not particularly limited; the total light transmittance may be 100% or less, but may also be, for example, 95% or less. The total light transmittance is measured in accordance with JIS K 7105.

[0083] The resin composition may contain a solvent. For example, if the resin composition is a paint-type resin composition, the inclusion of a solvent facilitates the coating of the resin composition. A resin composition containing a solvent can also be used as an ink composition.

[0084] The solvent may function to dissolve each component contained in the resin composition, or it may function as a dispersion medium, but it is preferable that the solvent dissolves the oxocarbon compound of this disclosure. As the solvent, any solvent that can be used for the oxocarbon compound solution described above can be used.

[0085] The solvent content is preferably, for example, 50% by mass or more, more preferably 70% by mass or more, less than 100% by mass, and more preferably 95% by mass or less, based on 100% by mass of the resin composition. By adjusting the solvent content within this range, it becomes easy to obtain a resin composition with a high concentration of oxocarbon compounds.

[0086] The resin composition may contain a surface modifier, which helps to suppress the occurrence of cosmetic defects such as striations and dents in the resin layer when the resin composition is cured to form a resin layer. The type of surface modifier is not particularly limited, and siloxane-based surfactants, acetylene glycol-based surfactants, fluorine-based surfactants, acrylic leveling agents, etc., can be used. Examples of surface modifiers include the BYK® series manufactured by BIC Chemie and the KF series manufactured by Shin-Etsu Chemical Co., Ltd.

[0087] The resin composition may contain a dispersant, which stabilizes the dispersibility of the oxocarbon compounds even if some of them are dispersed in the resin composition, thereby suppressing the re-aggregation of the oxocarbon compounds. The type of dispersant is not particularly limited, and can be used from the EFKA series from FKA Additives, Inc., the BYK® series from BIC Chemie Inc., the Solspers® series from Lubrizol Nippon Inc., the Disparon® series from Kusumoto Chemical Co., Ltd., the Azisper® series from Ajinomoto Fine Techno Inc., the KP series from Shin-Etsu Chemical Co., Ltd., the Polyflow series from Kyoeisha Chemical Co., Ltd., the Megafac® series from DIC Corporation, the DisperAid series from Sunopco Corporation, and others.

[0088] The resin composition may contain a silane coupling agent, its hydrolysate, or hydrolyzed condensate, which can improve the adhesion of the resin layer to the substrate when the resin composition is cured on the substrate to form a resin layer.

[0089] The resin composition may contain various additives as needed, such as plasticizers, surfactants, viscosity modifiers, defoamers, preservatives, and resistivity modifiers.

[0090] A molded article can be obtained by forming the resin composition into a predetermined shape. The molded article may be formed by curing the resin composition by heating (softening) and cooling, by curing it by a reaction of the resin components (e.g., polymerization reaction or crosslinking reaction), or by curing it after removing the solvent contained in the resin composition. As the resin composition, for example, a thermoplastic resin composition that can be molded by injection molding or extrusion molding, or a resin composition that has been made into a coating that can be applied by spin coating, solvent casting, roll coating, spray coating, bar coating, dip coating, screen printing, flexographic printing, inkjet printing, etc. can be used.

[0091] If the resin composition is a thermoplastic resin composition, a molded article can be obtained by injection molding, extrusion molding, vacuum molding, compression molding, blow molding, etc. In this method, a molded article can be obtained by blending an oxocarbon compound with a thermoplastic resin and then heat molding it. For example, an oxocarbon compound may be added to the powder or pellets of the base resin, heated to about 150°C to 350°C to melt it, and then molded. The shape of the molded article is not particularly limited, but examples include plate-like, sheet-like, granular, powder-like, lump-like, particle aggregate-like, spherical, ellipsoidal, lenticular, cubic, columnar, rod-like, conical, cylindrical, needle-like, fibrous, hollow fiber-like, porous, etc. Additives commonly used in resin molding, such as plasticizers, may also be added when kneading the resin.

[0092] If the resin composition is a paint-type resin composition, a liquid or paste-type resin composition containing an oxocarbon compound can be applied to a substrate (e.g., a resin plate, film, glass plate, etc.) to obtain a molded article in the form of a film with a thickness of 200 μm or less, or a sheet with a thickness exceeding 200 μm. The molded article thus obtained can be peeled from the substrate and handled as a film or sheet, or it can be handled as an integral part of the substrate.

[0093] A molded article of a resin composition may consist of a single resin layer (a layer formed by the curing of the resin composition) or of multiple resin layers. When the molded article is handled as an integral part of a substrate, the molded article may be formed on only one side of the substrate or on both sides. Furthermore, an integrated molded article and substrate can also be formed by heat-pressing or chemically bonding a molded article made from a resin composition to a substrate.

[0094] The resin compositions according to this disclosure can be preferably used as resin compositions for forming filters used in various applications such as optodevices, display devices, mechanical parts, and electrical and electronic components. The resin compositions and their molded articles can be suitably applied to optical filters such as near-infrared cut filters, and the optical filters thus formed have a resin layer formed from the resin composition of this disclosure. The optical filters may be formed from one or more resin layers, or they may be formed integrated with a support.

[0095] A filter integrated with a support can be formed, for example, by applying a resin composition to the surface of the support (or, if there is another layer such as a binder layer between the support and the resin layer, to the surface of that other layer) by a spin coating method or a solvent casting method, and then drying or curing it. Alternatively, a filter may be formed by heat-pressing a planar molded body made from the resin composition onto the support.

[0096] The resin layer formed from the resin composition may be provided on only one side of the support or on both sides. The thickness of the resin layer is not particularly limited, but from the viewpoint of ensuring the desired near-infrared cut performance, for example, it is preferably 0.5 μm or more, more preferably 1 μm or more, even more preferably 2 μm or more, and also preferably 1 mm or less, more preferably 500 μm or less, and even more preferably 200 μm or less. When the resin layer is formed on the support by coating it with a paint-like resin composition, the strength of the filter can be ensured by the support, so the thickness of the resin layer can be made even thinner. When the resin layer is formed on the support, for example, the thickness of the resin layer is preferably 50 μm or less, more preferably 20 μm or less, even more preferably 10 μm or less, and particularly preferably 5 μm or less.

[0097] As the support, it is preferable to use a transparent substrate such as a resin plate, resin film, or glass plate. The resin plate or resin film used as the support is preferably made from the resin components described above. From the viewpoint of improving the heat resistance of the optical filter, it is preferable to use a glass substrate as the support, and an optical filter formed in this way can be mounted on electronic components by, for example, solder reflow. In addition, since glass substrates are less prone to cracking or warping even when exposed to high temperatures, it is easier to ensure adhesion with the resin layer. When a glass substrate is used as the support, a binder layer made from, for example, a silane coupling agent may be provided between the support and the resin layer, thereby improving the adhesion between the resin layer and the glass substrate. Furthermore, the adhesion between the resin layer and the glass substrate can also be improved by including a silane coupling agent as an adhesion improver in the resin composition that forms the resin layer.

[0098] The thickness of the support (substrate) is preferably 0.05 mm or more, more preferably 0.1 mm or more, from the viewpoint of ensuring strength, and preferably 0.4 mm or less, more preferably 0.3 mm or less, from the viewpoint of thinning.

[0099] A protective layer, made of the same or a different resin as the resin layer, may be laminated onto the resin layer formed from the resin composition. By providing a protective layer, the durability (resistance to degradation) of the oxocarbon compounds contained in the resin layer can be increased. The protective layer may be provided on only one side of the resin layer or on both sides. When the resin layer is provided on a support, it is preferable that the protective layer be provided on the side of the resin layer opposite to the support.

[0100] When forming an optical filter from a resin composition, the optical filter may have a layer (anti-reflective coating) that has anti-reflective and anti-glare properties to reduce reflections from fluorescent lights, a layer that has scratch-resistant properties, or a transparent substrate with other functions. The optical filter may also have a near-infrared reflective coating or an ultraviolet reflective coating. It is preferable that these anti-reflective coatings, reflective coatings, or other layers are provided on the light-receiving side of the resin layer.

[0101] Near-infrared reflective films, ultraviolet reflective films, and anti-reflective films (visible light anti-reflective films) can be composed of dielectric films. Dielectric films are usually composed of dielectric multilayer films in which high refractive index material layers and low refractive index material layers are alternately stacked, but they may also be composed of only one of the high refractive index material layers or low refractive index material layers. As the material constituting the high refractive index material layer, a material with a refractive index of 1.7 or higher can be used, and it is preferable that a material with a refractive index in the range of 1.7 to 2.5 is selected, more preferably 1.8 or higher, and even more preferably 2.0 or higher. Examples of materials constituting the high refractive index material layer include oxides such as titanium oxide, zinc oxide, zirconium oxide, lanthanum oxide, yttrium oxide, indium oxide, niobium oxide, tantalum oxide, tin oxide, and bismuth oxide; nitrides such as silicon nitride; mixtures of the oxides and nitrides, or those doped with metals such as aluminum and copper or carbon (for example, tin-doped indium oxide (ITO), antimond-doped tin oxide (ATO)). As the material constituting the low refractive index material layer, a material with a refractive index of less than 1.7 can be used, and it is preferable that a material with a refractive index in the range of 1.2 to 1.6 be selected, and more preferably that a material with a refractive index in the range of 1.3 to 1.5 be selected. Examples of materials constituting the low refractive index material layer include silicon dioxide (silica, SiOx (x=1 to 2)), alumina, lanthanum fluoride, magnesium fluoride, and sodium aluminum hexafluoride. Among these, it is preferable that the high refractive index material layer be composed of titanium dioxide, and that the low refractive index material layer be composed of silicon dioxide.

[0102] The thicknesses of the high refractive index material layer and the low refractive index material layer are preferably adjusted to a range of 0.1λ to 0.5λ, and more preferably to a range of 0.2λ to 0.3λ, of the wavelength λ (nm) of the light to be blocked. By forming a dielectric film in this manner, light in a desired wavelength range can be selectively reflected, and the dielectric film can be used to form a near-infrared reflective film, an ultraviolet reflective film, an anti-reflective film (visible light anti-reflective film), etc. The ultraviolet reflective film and the near-infrared reflective film may be a single film that has both ultraviolet and near-infrared reflective functions.

[0103] The number of dielectric film layers is not particularly limited as long as it is one or more layers, but from the viewpoint of exhibiting desired optical performance as a near-infrared reflective film, ultraviolet reflective film, anti-reflective film, etc., it is preferable to have, for example, 2 to 80 layers. The number of dielectric film layers may be 5 or more layers, 10 or more layers, or 20 or more layers, and may also be 70 or less layers, or 60 or less layers. The thickness of the dielectric film is not particularly limited, and may be in the range of 0.01 μm to 10 μm, but from the viewpoint of sufficiently cutting the incidence of light in the desired wavelength range, it is preferable to have a thickness of 0.02 μm or more, more preferably 0.03 μm or more, and from the viewpoint of thinning, it is preferable to have a thickness of 5 μm or less, and more preferably 3 μm or less.

[0104] The optical filter may have an aluminum vapor-deposited film, a noble metal thin film, or a resin film in which metal oxide fine particles mainly composed of indium oxide and containing a small amount of tin oxide are dispersed.

[0105] The thickness of the optical filter is preferably, for example, 1 mm or less. This allows for sufficient meeting of the demand for miniaturization of the image sensor, for example. More preferably, the thickness of the optical filter is 500 μm or less, even more preferably 300 μm or less, even more preferably 150 μm or less, and also preferably 30 μm or more, and even more preferably 50 μm or more.

[0106] Optical filters can be used as components of sensors such as image sensors, illuminance sensors, and proximity sensors. For example, an image sensor is an electronic component that converts light from a subject into an electrical signal and outputs it, and examples include CCD (Charge Coupled Device) and CMOS (Complementary Metal-Oxide Semiconductor). Image sensors can be used in mobile phone cameras, digital cameras, in-vehicle cameras, surveillance cameras, display elements (LEDs, etc.), etc. The sensor includes one or more of the above-mentioned optical filters and may also have other filters (e.g., visible light cut filters, infrared cut filters, ultraviolet cut filters, etc.) or lenses as needed.

[0107] This application claims the benefit of priority based on Japanese Patent Application No. 2024-186602, filed on 23 October 2024. The entire specification of Japanese Patent Application No. 2024-186602, filed on 23 October 2024, is incorporated herein by reference.

[0108] The contents of this disclosure will be explained in more detail below with reference to examples, but the contents of this disclosure are not limited by the examples below, and it is possible to implement them with appropriate modifications to the extent that they are in line with the spirit of the preceding and following, and all such modifications are included in the technical scope of this disclosure.

[0109] (1) Synthesis of Compounds (1-1) Synthesis Example 1: Synthesis of Squarylium Compound 1 7.21 g (0.12 mol) of potassium hydroxide and 150 mL of dimethyl sulfoxide were added to a 300 mL four-necked flask and stirred at room temperature for 30 minutes. Next, a mixture of 5.68 g (0.040 mol) of iodomethane and 7.29 g (0.040 mol) of cyclododecanone was added dropwise, and the mixture was heated to an internal temperature of 40°C and stirred for 2 hours to allow the reaction to proceed. After the reaction was complete, the reaction mixture, 200 mL of ethyl acetate and 300 mL of water were added to a separatory funnel and stirred vigorously to extract the organic phase. Anhydrous magnesium sulfate was added to the extracted organic phase to dehydrate it. After filtering off the solids (inorganic components) from this organic phase, the solvent was removed using a rotary evaporator. After solvent removal, the mixture was dried in a vacuum dryer at 40°C for 12 hours to obtain 4.01 g of 2-methylcyclododecanone. The yield relative to cyclododecanone was 51.1 mol%.

[0110] Next, 5.01 g (0.035 mol) of phenylhydrazine hydrochloride, 6.87 g (0.035 mol) of the 2-methylcyclododecanone obtained above, and 30 g of t-amyl alcohol were placed in a 300 mL four-necked flask, and the mixture was reacted at 100°C for 7 hours under a nitrogen flow (10 mL / min) while stirring with a magnetic stirrer. After the reaction was complete, the reaction mixture, 200 mL of ethyl acetate, and 300 mL of water were added to a separatory funnel and vigorously stirred to extract the organic phase. Anhydrous magnesium sulfate was added to the extracted organic phase to dehydrate it. After filtering off the solids (inorganic components) from this organic phase, the solvent was removed by distillation using a rotary evaporator. After solvent removal, the mixture was dried in a vacuum dryer at 60°C for 12 hours to obtain 5.83 g of intermediate 1A. The yield relative to phenylhydrazine hydrochloride was 61.8 mol%.

[0111] Next, 5.83 g (0.022 mol) of the intermediate 1A obtained above, 1.25 g (0.011 mol) of squalic acid, 60 g of 1-butanol, and 60 g of toluene were placed in a 300 mL four-necked flask. The mixture was stirred with a magnetic stirrer under a nitrogen flow (10 mL / min), and the reaction was carried out under reflux conditions for 3 hours while removing eluted water using a Dean-Stark apparatus. After the reaction was complete, the solvent was removed by distillation using a rotary evaporator, and then 50 g of methanol was added and crystallization and washing were performed under reflux conditions with stirring for 30 minutes. After the solution was cooled to room temperature, the cake obtained by filtration was dried in a vacuum dryer at 60°C for 12 hours, and then purified as appropriate by silica gel column chromatography (eluent: mixture of chloroform and hexane) to obtain 4.10 g of the target product, squarylium compound 1. The yield relative to squalic acid was 60.4 mol%.

[0112]

[0113] (1-2) Synthesis Example 2: Synthesis of Squallium Compound 2 Squallium Compound 2 shown in Table 1 was obtained by the same procedure as in Synthesis Example 1, except that 2-methoxyphenylhydrazine hydrochloride was used instead of phenylhydrazine hydrochloride. The yield relative to squalic acid was 51.1 mol%.

[0114] (1-3) Synthesis Example 3: Synthesis of Squallium Compound 3 Except for using 3,4-dimethylphenylhydrazine hydrochloride instead of phenylhydrazine hydrochloride in Synthesis Example 1, Squallium Compound 3 shown in Table 1 was obtained using the same procedure as in Synthesis Example 1. １ Results from 1H-NMR analysis and other methods suggested that the obtained squarylium compound included structural isomers of squarylium compound 3 with different substituent positions on ring B. The yield relative to squalate was 58.2 mol%.

[0115] (1-4) Synthesis Example 4: Synthesis of Squallium Compound 4 Except for using 2,3-dihydro-1,4-benzodiosin-6-ylhydrazine hydrochloride instead of phenylhydrazine hydrochloride in Synthesis Example 1, Squallium Compound 4 shown in Table 1 was obtained by the same procedure as in Synthesis Example 1. １ Results from 1H-NMR analysis and other methods suggested that the obtained squarylium compound included structural isomers of squarylium compound 4 with different substituent positions on ring B. The yield relative to squalate was 40.3 mol%.

[0116] (1-5) Synthesis Example 5: Synthesis of Squallium Compound 5 Squallium compound 5 shown in Table 1 was obtained by the same procedure as in Synthesis Example 1, except that 3-t-butylphenylhydrazine hydrochloride was used instead of phenylhydrazine hydrochloride. The yield relative to squalic acid was 62.8 mol%.

[0117] (1-6) Synthesis Example 6: Synthesis of Squallium Compound 6 Squallium Compound 6 shown in Table 1 was obtained by the same procedure as in Synthesis Example 1, except that 4-trifluoromethylphenylhydrazine hydrochloride was used instead of phenylhydrazine hydrochloride. The yield relative to squalic acid was 65.3 mol%.

[0118] (1-7) Synthesis Example 7: Synthesis of Squallium Compound 7 Squallium compound 7 shown in Table 1 was obtained by the same procedure as in Synthesis Example 1, except that naphthylhydrazine hydrochloride was used instead of phenylhydrazine hydrochloride. The yield relative to squalic acid was 48.8 mol%.

[0119] (1-8) Synthesis Example 8: Synthesis of Squallium Compound 8 Squallium Compound 8 shown in Table 1 was obtained by the same procedure as in Synthesis Example 1, except that [4-(phenylmethoxy)phenyl]hydrazine hydrochloride was used instead of phenylhydrazine hydrochloride. The yield relative to squalic acid was 40.3 mol%.

[0120] (1-9) Synthesis Example 9: Synthesis of Squallium Compound 9 Squallium compound 9 shown in Table 1 was obtained by the same procedure as in Synthesis Example 1, except that 2,5-dimethylphenylhydrazine hydrochloride was used instead of phenylhydrazine hydrochloride. The yield relative to squalic acid was 41.4 mol%.

[0121] (1-10) Synthesis Example 10: Synthesis of Squallium Compound 10. Except for using 3,5-dimethylphenylhydrazine hydrochloride instead of phenylhydrazine hydrochloride in Synthesis Example 1, the same procedure as in Synthesis Example 1 was used to obtain Squallium Compound 10 shown in Table 1. The yield relative to squalic acid was 43.2 mol%.

[0122] (1-11) Synthesis Example 11: Synthesis of Squallium Compound 11 The Squallium Compound 11 shown in Table 1 was obtained by the same procedure as in Synthesis Example 1, except that cyclopentadecanone was used instead of cyclododecanone. The yield relative to squalic acid was 48.4 mol%.

[0123] (1-12) Synthesis Example 12: Synthesis of Squallium Compound 12. Except for using 4-methylphenylhydrazine hydrochloride instead of phenylhydrazine hydrochloride in Synthesis Example 11, Squallium Compound 12 shown in Table 1 was obtained by the same procedure as in Synthesis Example 11. The yield relative to squalic acid was 51.5 mol%.

[0124] (1-13) Synthesis Example 13: Synthesis of Squallium Compound 13. Squallium compound 13 shown in Table 1 was obtained by the same procedure as in Synthesis Example 11, except that 4-trifluoromethylphenylhydrazine hydrochloride was used instead of phenylhydrazine hydrochloride. The yield relative to squalic acid was 32.5 mol%.

[0125] (1-14) Synthesis Example 14: Synthesis of Comparative Squaryllium Compound 1 Comparative squarylium compound 1 was synthesized according to the method described in Example 1-18 of Japanese Patent Publication No. 2016-074649.

[0126] (1-15) Synthesis Example 15: Synthesis of Comparative Squallium Compound 2 Comparative Squallium Compound 2 shown in Table 1 was obtained by the same procedure as in Synthesis Example 14, except that 4-trifluoromethylphenylhydrazine hydrochloride was used instead of phenylhydrazine hydrochloride in Synthesis Example 1. The yield relative to squalic acid was 49.1 mol%.

[0127]

[0128] (2) Spectroscopic Measurement Chloroform solutions of squarylium compounds 1-13 and comparative squarylium compounds 1-2 were prepared, and their absorption spectra at wavelengths of 300 nm to 1100 nm were measured. The concentration of the chloroform solution of the squarylium compound was adjusted so that the absorbance at the wavelength of maximum absorption (absorption maximum wavelength λmax) was 1 ± 0.005, and the measurements were taken using a spectrophotometer (Shimadzu Corporation, UV-1800) at a measurement pitch of 0.5 nm. The results are shown in Table 2. The absorption spectrum of squarylium compound 1 is shown in Figure 1.

[0129]

[0130] Squallium compound 1, Squallium compound 11, and comparative Squallium compound 1 all have an unsubstituted unsaturated hydrocarbon ring A and an unsubstituted benzene ring B. The λmax of these Squallium compounds is compared. Comparative Squallium compound 1, with 6 members in ring A, had a λmax of 730.0 nm. Squallium compound 1 with 12 members in ring A had a λmax of 735.0 nm, while Squallium compound 11 with 15 members in ring A had a λmax of 733.5 nm. Thus, Squallium compound 1 and Squallium compound 11 have longer absorption maximum wavelengths than comparative Squallium compound 1. Squallium compound 6, Squallium compound 13, and comparative Squallium compound 2 all have an unsubstituted unsaturated hydrocarbon ring A and a benzene ring with a trifluoromethyl group bonded at the same position in ring B. The λmax of these Squallium compounds is compared. While comparative squarylium compound 2, with ring A having 6 members, had a λmax of 726.0 nm, squarylium compound 6, with ring A having 12 members, had a λmax of 730.0 nm, and squarylium compound 13, with ring A having 15 members, had a λmax of 728.0 nm. Thus, squarylium compounds 6 and 13 had longer absorption maximum wavelengths than comparative squarylium compound 2. Squaryllium compounds 2-5 and 7-12 had even longer absorption maximum wavelengths than squarylium compounds 1 and 6.

[0131] From the absorption spectrum of squarylium compound 1 (Figure 1), the ratio of the absorbance Abs(450) at a wavelength of 450 nm to the absorbance Abs(750) at a wavelength of 750 nm (Abs(450) / Abs(750) × 100) can be calculated to be 0.70. Squaryllium compound 1 can effectively absorb light near the boundary between the red and near-infrared regions, and can also increase the transmittance of light in the visible light region.

[0132] (3) Preparation of the resin composition In a 2-liter reaction vessel equipped with a stirring blade, 10.01 g (0.044 mol) of 2,2'-bis(4-hydroxyphenyl)propane, 3.59 g (0.090 mol) of sodium hydroxide, and 300 g of deionized water were charged and dissolved. Then, 0.89 g (0.009 mol) of triethylamine was added and dissolved. A solution of 3.57 g (0.021 mol) of terephthalic acid dichloride and 3.57 g (0.021 mol) of isophthalic acid dichloride dissolved in 500 g of methylene chloride was placed in a dropping funnel and attached to the reaction vessel. The solution in the reaction vessel was stirred while maintaining the temperature at 20°C, and the methylene chloride solution was added dropwise from the dropping funnel over 60 minutes. Next, a solution of 0.71 g (0.005 mol) of benzoyl chloride dissolved in 10 g of methylene chloride was added, and the mixture was stirred for 60 minutes. The resulting reaction solution was neutralized with aqueous acetic acid to adjust the pH of the aqueous phase to 7, and then the oil phase and aqueous phase were separated using a separatory funnel. The obtained oil phase was added dropwise to methanol under stirring to reprecipitate the polymer, and the precipitate was collected by filtration and dried in an 80°C oven to obtain a white solid polyarylate resin. The yield was 11.5 g. The weight-average molecular weight (Mw) of the obtained polyarylate resin was 33,780, and the number-average molecular weight (Mn) was 8,130. The weight-average molecular weight and number-average molecular weight of the polyarylate resin are polystyrene equivalent values ​​determined by gel permeation chromatography.

[0133] The polyarylate resin obtained above was mixed with 100 parts by mass of squarylium compound 5, 342 parts by mass of toluene, and 530 parts by mass of xylene. These mixtures were stirred at room temperature for 1 hour and at 40°C for 1 hour, respectively. The mixture was then filtered through a 0.1 μm pore size filter (GL Chromatodisk, non-aqueous 13N, manufactured by GL Sciences Co., Ltd.) to remove impurities and obtain a resin composition.

[0134] (4) Optical Filter (4-1) Fabrication of Optical Filter After dropping 2 cc of the resin composition obtained above onto a glass substrate (Schott, D263Teco), the resin composition was deposited on the glass substrate using a spin coater (Mikasa, 1H-D7) by increasing the rotation speed to 1900 rpm over 0.2 seconds, holding it at that speed for 20 seconds, and then decreasing it to 0 rpm over 0.2 seconds. The glass substrate on which the resin composition was deposited was initially dried at 100°C for 3 minutes using a precision constant temperature oven (Yamato Scientific, DH611) (before curing). Then, using an inert oven (Yamato Scientific, DN610I), the atmosphere was purged with nitrogen at 50°C for 30 minutes, the temperature was raised to 190°C in about 15 minutes, and the glass substrate was dried at 190°C for 60 minutes under a nitrogen atmosphere to form a resin layer (absorption layer) on the glass substrate (after curing). An optical filter was fabricated by forming a resin layer on the glass substrate in this way.

[0135] (4-2) Transmission Spectrum Measurement For optical filters with a resin layer formed on a glass substrate, the transmission spectrum was measured at a measurement pitch of 1 nm using a spectrophotometer (Shimadzu Corporation, UV-1800), and the transmittance of light at wavelengths from 300 nm to 900 nm was determined. The transmission spectrum was measured for optical filters before and after curing of the resin layer. The results are shown in Figure 2.

[0136] The oxocarbon compounds relating to this disclosure can be used, for example, in electronic components such as mobile phone cameras, digital cameras, in-vehicle cameras, surveillance cameras, display elements (LEDs, etc.), and security inks.

Claims

1. An oxocarbon compound represented by the following formula (1) or formula (2). [In equations (1) and (2), R １ ~R ４ Each of these independently represents a structural unit shown in formula (3) below. [In formula (3), ring A represents an optionally substituted 10-18 member unsaturated hydrocarbon ring, ring B represents an optionally substituted aromatic hydrocarbon ring, an optionally substituted aromatic heterocycle, or an optionally substituted fused ring containing these ring structures, X represents an alkyl group, an aryl group, or an aralkyl group, and * represents a bonding site with the 4-membered ring in formula (1) or the 5-membered ring in formula (2).] 2. The oxocarbon compound according to claim 1, wherein ring B may have substituents, a benzene ring or a naphthalene ring.

3. The oxocarbon compound according to claim 1, wherein the oxocarbon compound is a squarylium compound represented by formula (1).

4. A composition comprising an oxocarbon compound according to any one of claims 1 to 3.

5. A resin composition comprising an oxocarbon compound and a resin component according to any one of claims 1 to 3.

6. The resin composition according to claim 5, further comprising a solvent.

7. A molded article formed from the resin composition described in claim 5.

8. An optical filter having a resin layer formed from the resin composition described in claim 5.

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