JP6599192B2 - Oxocarbon compounds - Google Patents

Description

  The present invention relates to an oxocarbon-based compound having a squarylium skeleton or a croconium skeleton, a resin composition including the compound, and an optical filter including the resin composition.

  An oxocarbon-based compound having a squarylium skeleton or a croconium skeleton in the compound is useful as a pigment having an absorption region in the visible to near-infrared region, for example, a cut filter for visible light or infrared light, a near-infrared absorbing film, Expected to be used as security ink. An oxocarbon-based compound having a squarylium skeleton or a croconium skeleton is generally synthesized by using squaric acid or croconic acid as a raw material and introducing heterocyclic groups at both ends of the raw material. As such oxocarbon compounds, for example, the following compounds are known.

  Patent Document 1 discloses a squarylium compound represented by the following formula (Example 2 of Patent Document 1).

  Patent Document 2 discloses a squarylium compound represented by the following formula (Example 14 of Patent Document 2).

  Furthermore, Patent Document 2 discloses a croconium compound represented by the following formula (Example 17 of Patent Document 2).

  Patent Document 3 discloses a squarylium compound represented by the following formula (Example 1 of Patent Document 3).

  Patent Document 4 discloses a squarylium compound represented by the following formula.

  Non-Patent Document 1 discloses a squarylium compound represented by the following formula.

  Non-Patent Document 2 discloses a croconium compound represented by the following formula.

  By the way, an imaging device that converts light of an object into an electric signal or the like is normally used in an imaging device such as a mobile phone camera, a digital camera, an in-vehicle camera, a video camera, and a display device (LED, etc.). However, such an image sensor includes a detection element (sensor) such as a CCD (Charge Coupled Device) and a CMOS (Complementary Metal-Oxide Semiconductor) and a lens, and hinders image processing and the like for high performance. In some cases, an optical filter such as a near-infrared cut filter for removing optical noise (for example, ghost or flare) is provided. Patent Documents 3 and 4 disclose a near-infrared cut filter containing a squarylium compound having a maximum absorption wavelength in the wavelength region of 660 to 710 nm as such an optical filter. In the case of a normal visible light image sensor, by providing an optical filter including a dye having a maximum absorption wavelength in a wavelength region around 700 nm, the dependency of the optical characteristics on the incident angle can be reduced and the viewing angle can be improved. it can.

  On the other hand, some imaging devices are required to have a photographing function under night vision, such as surveillance cameras, in addition to general digital cameras and video cameras. Shooting under night vision such as at night is performed in a state invisible to the human eye. For example, it is performed by irradiating a light beam in the near infrared region and receiving the reflected light with an imaging device. .

JP 2008-308602 A JP-A-6-25165 JP 2014-148567 A JP 2014-059550 A

Tetrahedron Letters, 1999, vol.40, p.4067-4068 Tetrahedron Letters, 2002, vol.43, p.8391-8393

  Even in a night vision image sensor, it is required to reduce the incident angle dependency of optical characteristics as in a normal visible light image sensor. Even if an infrared cut filter (for example, an optical filter having a maximum absorption wavelength in a wavelength range of around 700 nm) is used, it is difficult to reduce the incident angle dependency. For example, a light beam in a desired wavelength range within a wavelength range of 800 to 1000 nm. It is necessary to provide a cut filter that absorbs water. In other words, in an imaging device for night vision, it is desirable to provide an optical filter including a dye that can absorb light in a wavelength region exceeding about 800 nm in order to reduce the incident angle dependency of optical characteristics.

  The present invention has been made in view of the above circumstances, and its purpose is to exceed the wavelength of about 800 nm, an oxocarbon compound capable of effectively absorbing light in a wavelength region exceeding about 800 nm, a resin composition containing the oxocarbon compound. An object of the present invention is to provide an optical filter capable of effectively cutting light in a wavelength region.

  The oxocarbon compound of the present invention that has solved the above-described problems is characterized by being represented by the following formula (1) or the following formula (2).

[In Formula (1) and Formula (2), R ^{1 to} R ⁴ each independently represent a structural unit represented by the following Formula (3). ]

[In Formula (3), Ring A represents a 4- to 9-membered unsaturated hydrocarbon ring; Ring B represents an optionally substituted aromatic hydrocarbon ring, aromatic heterocyclic ring, or these And a ring B contains 12 or more π electrons; X represents a hydrogen atom, an organic group or a polar functional group; Y represents an organic group or a polar functional group * Represents a bonding site with a 4-membered ring in formula (1) or a 5-membered ring in formula (2); n is an integer of 0 to 6 and m or less (where m is ring A In the case where n is 2 or more, the plurality of Y may be the same or different. ]

  In the oxocarbon-based compound of the present invention, the structural unit represented by the formula (3) bonded to the squarylium skeleton or the croconium skeleton has a ring A and a ring B, and the π electrons contained in the ring B are 12 or more. Therefore, π electrons spread over the entire molecule over a wide range, the absorption wavelength shifts by a long wavelength, and light in a wavelength region exceeding about 800 nm can be effectively absorbed. For this reason, the oxocarbon compound of the present invention is applied to, for example, an optical filter of an imaging device for night vision, thereby reducing the incident angle dependency of the optical characteristics on the short wavelength side in the near infrared region and improving the viewing angle. can do. The oxocarbon-based compound of the present invention does not need to absorb light in the entire wavelength range exceeding about 800 nm, and for example, can absorb a certain amount of light in a part of the wavelength range of 800 to 1000 nm. That's fine.

  Y is preferably an alkyl group or a hydroxyl group. X is preferably an alkyl group or an aryl group.

  The present invention also provides a resin composition containing the oxocarbon compound of the present invention and a resin component, and an optical filter containing the resin composition. The resin composition of the present invention can be suitably applied to, for example, an optical filter of an imaging device for night vision by being formed into a film, thereby effectively radiating light in a wavelength region exceeding about 800 nm. The optical filter can be cut to reduce the incident angle dependence of the optical characteristics on the short wavelength side in the near infrared region, and the viewing angle can be improved.

  The oxocarbon-based compound of the present invention can effectively absorb light in a wavelength region exceeding about 800 nm. Therefore, the resin composition containing the oxocarbon-based compound of the present invention can be suitably applied to, for example, an optical filter of an imaging device for night vision by being formed into a film, thereby exceeding about 800 nm. By effectively cutting light in the wavelength range, the optical angle in the near-infrared region (for example, 800 to 1000 nm) is reduced in the incident angle dependency, and an optical filter with an improved viewing angle can be obtained.

Each transmission spectrum of a squarylium compound and a phthalocyanine compound is represented.

  The oxocarbon-based compound of the present invention is represented by the following formula (1) having a squarylium skeleton or the following formula (2) having a croconium skeleton.

In formula (1) and formula (2), R ^{1 to} R ⁴ each independently represents a structural unit represented by the following formula (3).

  In formula (3), ring A represents a 4- to 9-membered unsaturated hydrocarbon ring, and ring B is an aromatic hydrocarbon ring, aromatic heterocycle, or these optionally having substituents Represents a condensed ring containing a ring structure, wherein the ring B contains 12 or more π electrons, X represents a hydrogen atom, an organic group or a polar functional group, Y represents an organic group or a polar functional group, * Represents a bonding site to the 4-membered ring in formula (1) or the 5-membered ring in formula (2), n is an integer of 0 to 6 and m or less (where m is the structure of ring A) In the case where n is 2 or more, a plurality of Y may be the same or different.

  In some cases, a compound having a squarylium skeleton (hereinafter referred to as “squarylium compound”) and a compound having a croconium skeleton (hereinafter referred to as “croconium compound”) each have a conjugated relationship. Examples of the compound conjugated with the squarylium compound of the formula (1) include compounds represented by the following formulas (1a) and (1b). Examples of the compound having a conjugated relationship with the croconium compound of the formula (2) include compounds represented by the following formulas (2a) to (2c). The oxocarbon-based compound of the present invention includes all these conjugated compounds. Specifically, the squarylium compound of the formula (1) includes those represented by the following formulas (1a) and (1b). Compounds having a conjugated relationship are included, and the croconium compound of the formula (2) includes compounds having a conjugated relationship as represented by the following formulas (2a) to (2c).

  In the structural unit represented by the formula (3) bonded to the squarylium skeleton or the croconium skeleton, * represents a 4-membered ring of the squarylium skeleton represented by the formula (1) or a 5-membered ring of the croconium skeleton represented by the formula (2) Represents the binding site.

  In formula (3), ring A represents an unsaturated hydrocarbon ring having 4 to 9 members. Ring A has a double bond between the carbon atom bonded to the squarylium skeleton or the croconium skeleton and the α-position carbon atom of the pyrrole ring, and includes the α-position carbon and the β-position carbon of the pyrrole ring. An unsaturated hydrocarbon ring. Ring A may have an unsaturated bond (preferably a double bond) in addition to the double bond, and preferably has only one unsaturated bond (double bond). Ring A is preferably a 5- to 8-membered ring, more preferably a 6- to 8-membered ring.

Since the oxocarbon compound of the present invention has ring A, the association between molecules is promoted, and as a result, the shoulder peak of the absorption waveform can be greatly reduced, and the optical characteristics can be improved. . Furthermore, the oxocarbon-based compound of the present invention has a narrow band gap of the π-π ^* transition due to molecular distortion due to the ring A, and the π-electron system can be spread over a wide range by the ring B. Longer wavelength can be achieved.

  Examples of the structure of ring A include cyclobutene, cyclopentene, cyclopentadiene, cyclohexene, cyclohexadiene, cycloheptene, cycloheptadiene, cycloheptatriene, cyclooctene, cyclooctadiene, cyclooctatriene, cyclononene, cyclononadiene, cyclononatriene, Examples include cycloalkene structures such as cyclononatetraene. Of these, cycloalkane monoenes such as cyclopentene, cyclohexene, cycloheptene, and cyclooctene are preferable.

  Ring A may have a substituent Y. Examples of the substituent Y include an organic group and a polar functional group. The number n of the substituent Y is 0 to 6 and is m or less (where m is a value obtained by subtracting 3 from the number of members of the ring A). When n is 2 or more, the plurality of Y may be the same or different. n is preferably an integer of 0 to 5, more preferably an integer of 0 to 3, and still more preferably an integer of 0 to 2. When n is 1 or more, the hydrogen atom bonded to the carbon atom constituting the ring A is substituted with Y.

Examples of the organic group represented by Y include an alkyl group, an alkoxy group, an alkylthiooxy group (alkylthio group), an alkoxycarbonyl group, an alkylsulfonyl group, an aryl group, an aralkyl group, an aryloxy group, an arylthiooxy group (arylthio group). group), an aryloxycarbonyl group, an arylsulfonyl group, an arylsulfinyl group, a heteroaryl group, an amide group (-NHCOR), a sulfonamido group (-NHSO ₂ R), a carboxy group (carboxylic acid group), benzothiazole group, a halogeno An alkyl group, a cyano group, etc. are mentioned. Examples of the polar functional group include a halogeno group, a hydroxyl group, a nitro group, an amino group, and a sulfo group (sulfonic acid group).

  Examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group. A linear or branched alkyl group such as a group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group; cyclopropyl group, cyclobutyl group, cyclopentyl group, And alicyclic alkyl groups such as a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, and a cyclodecyl group; 1-20 are preferable, as for carbon number of an alkyl group, More preferably, it is 1-10, More preferably, it is 1-6, and 3 or more are preferable especially in the case of an alicyclic alkyl group. The alkyl group may have a substituent, and examples of the substituent that the alkyl group has include a halogeno group, a hydroxyl group, a carboxy group, an alkoxy group, a cyano group, a nitro group, an amino group, and a sulfo group.

  Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a nonyloxy group, a decyloxy group, an undecyloxy group, and a dodecyloxy group. A tridecyloxy group, a tetradecyloxy group, a pentadecyloxy group, a hexadecyloxy group, a heptadecyloxy group, an octadecyloxy group, a nonadecyloxy group, an icosyloxy group, and the like. 1-20 are preferable, as for carbon number of an alkoxy group, More preferably, it is 1-10, More preferably, it is 1-5. The alkyl group in the alkoxy group may be linear or branched.

  Examples of the alkylthiooxy group (alkylthio group) include a methylthiooxy group (methylthio group), an ethylthiooxy group (ethylthio group), a propylthiooxy group (propylthio group), a butylthiooxy group (butylthio group), and pentylthio. Oxy group (pentylthio group), hexylthiooxy group (hexylthio group), heptylthiooxy group (heptylthio group), octylthiooxy group (octylthio group), nonylthiooxy group (nonylthio group), decylthiooxy group (decylthio group) ), Undecylthiooxy group (undecylthio group), dodecylthiooxy group (dodecylthio group), tridecylthiooxy group (tridecylthio group), tetradecylthiooxy group (tetradecylthio group), pentadecylthiooxy group (penta Decylthio group), f Sadecylthiooxy group (hexadecylthio group), heptadecylthiooxy group (heptadecylthio group), octadecylthiooxy group (octadecylthio group), nonadecylthiooxy group (nonadecylthio group), icosylthiooxy group (icosylthio group), etc. Is mentioned. 1-20 are preferable, as for carbon number of an alkylthiooxy group, More preferably, it is 1-10, More preferably, it is 1-5. The alkyl group in the alkylthiooxy group may be linear or branched.

  Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, a butoxycarbonyl group, a pentyloxycarbonyl group, a hexyloxycarbonyl group, a heptyloxycarbonyl group, an octyloxycarbonyl group, a decyloxycarbonyl group, In addition to unsubstituted alkoxycarbonyl groups such as octadecyloxycarbonyl group, substituted alkoxycarbonyl groups such as trifluoromethyloxycarbonyl group can be mentioned. Here, examples of the substituent include a halogeno group. 2-20 are preferable, as for carbon number of an alkoxycarbonyl group, More preferably, it is 2-10, More preferably, it is 2-5. The alkyl group in the alkoxycarbonyl group may be linear or branched.

  Examples of the alkylsulfonyl group include a methylsulfonyl group, an ethylsulfonyl group, a propylsulfonyl group, an isopropylsulfonyl group, a butylsulfonyl group, a hexylsulfonyl group, a cyclohexylsulfonyl group, a 2-ethylhexylsulfonyl group, an octylsulfonyl group, and a methoxymethylsulfonyl. Group, a cyanomethylsulfonyl group, a substituted or unsubstituted alkylsulfonyl group of a trifluoromethylsulfonyl group, and the like. 1-20 are preferable, as for carbon number of an alkylsulfonyl group, More preferably, it is 1-10, More preferably, it is 1-5. The alkyl group in the alkylsulfonyl group may be linear or branched.

  Examples of the aryl group include a phenyl group, a biphenyl group, a naphthyl group, an anthryl group, a phenanthryl group, a pyrenyl group, an indenyl group, an azulenyl group, a fluorenyl group, a terphenyl group, a quarterphenyl group, a pentarenyl group, a heptaenyl group, and a biphenylenyl group. Group, indacenyl group, acenaphthylenyl group, phenalenyl group and the like. 6-20 are preferable and, as for carbon number of an aryl group, More preferably, it is 6-15. The aryl group may have a substituent, and examples of the substituent that the aryl group has include an alkyl group, an alkoxy group, a halogeno group, a cyano group, a nitro group, a thiocyanate group, an acyl group, an alkoxycarbonyl group, and an aryloxy group. Examples include carbonyl group, carbamoyl group, sulfo group, alkylsulfinyl group, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, sulfamoyl group and the like.

  Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a phenylbutyl group, and a phenylpentyl group. The aralkyl group may have a substituent, and examples of the substituent that the aralkyl group has include an alkyl group, an alkoxy group, a halogeno group, a cyano group, a nitro group, a thiocyanate group, an acyl group, an alkoxycarbonyl group, and an aryloxy group. Examples include carbonyl group, carbamoyl group, sulfo group, alkylsulfinyl group, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, sulfamoyl group and the like. 6-25 are preferable and, as for carbon number of an aralkyl group, 6-15 are more preferable.

  Examples of the aryloxy group include phenyloxy group, biphenyloxy group, naphthyloxy group, anthryloxy group, phenanthryloxy group, pyrenyloxy group, indenyloxy group, azulenyloxy group, fluorenyloxy group, Examples include a phenyloxy group, a quarterphenyloxy group, a pentarenyloxy group, a heptaenyloxy group, a biphenylenyloxy group, an indacenyloxy group, an acenaphthylenyloxy group, and a phenalenyloxy group. 6-25 are preferable and, as for carbon number of an aryloxy group, More preferably, it is 6-15.

  Examples of the arylthiooxy group (arylthio group) include a phenylthiooxy group, a biphenylthiooxy group, a naphthylthiooxy group, an anthrylthiooxy group, a phenanthrylthiooxy group, a pyrenylthiooxy group, and an indenylthio group. Oxy group, azulenylthiooxy group, fluorenylthiooxy group, terphenylthiooxy group, quarterphenylthiooxy group, pentarenylthiooxy group, heptalenylthiooxy group, biphenylenylthiooxy group, indacenylthiooxy group Acenaphthylenylthiooxy group, phenalenylthiooxy group and the like. 6-25 are preferable and, as for carbon number of an arylthiooxy group, 6-15 are more preferable.

  Examples of the aryloxycarbonyl group include phenoxycarbonyl group, 4-dimethylaminophenyloxycarbonyl group, 4-diethylaminophenyloxycarbonyl group, 2-chlorophenyloxycarbonyl group, 2-methylphenyloxycarbonyl group, 2-methoxyphenyl. Oxycarbonyl group, 2-butoxyphenyloxycarbonyl group, 3-chlorophenyloxycarbonyl group, 3-trifluoromethylphenyloxycarbonyl group, 3-cyanophenyloxycarbonyl group, 3-nitrophenyloxycarbonyl group, 4-fluorophenyloxy A substituted or unsubstituted phenyloxycarbonyl group such as a carbonyl group, 4-cyanophenyloxycarbonyl group, 4-methoxyphenyloxycarbonyl group, etc .; 1-naphthyloxy Carbonyl group, a substituted or unsubstituted naphthyl oxycarbonyl group such as a 2-naphthyloxycarbonyl group; and the like. 6-25 are preferable and, as for carbon number of an aryloxycarbonyl group, More preferably, it is 6-15.

  Examples of the arylsulfonyl group include a phenylsulfonyl group, a 1-naphthylsulfonyl group, a 2-naphthylsulfonyl group, a 2-chlorophenylsulfonyl group, a 2-methylphenylsulfonyl group, a 2-methoxyphenylsulfonyl group, and 2-butoxyphenylsulfonyl. Group, 2-fluorophenylsulfonyl group, 3-methylphenylsulfonyl group, 3-chlorophenylsulfonyl group, 3-trifluoromethylphenylsulfonyl group, 3-cyanophenylsulfonyl group, 3-nitrophenylsulfonyl group, 3-fluorophenylsulfonyl Group, 4-methylphenylsulfonyl group, 4-fluorophenylsulfonyl group, 4-cyanophenylsulfonyl group, 4-methoxyphenylsulfonyl group, 4-dimethylaminophenylsulfonyl group, etc. Other unsubstituted phenylsulfonyl group; 1-naphthylsulfonyl group, 2-substituted or unsubstituted naphthylsulfonyl group such naphthylsulfonyl group; and the like. 6-25 are preferable and, as for carbon number of an arylsulfonyl group, 6-15 are more preferable.

  Examples of the arylsulfinyl group include a phenylsulfinyl group, a 2-chlorophenylsulfinyl group, a 2-methylphenylsulfinyl group, a 2-methoxyphenylsulfinyl group, a 2-butoxyphenylsulfinyl group, a 2-fluorophenylsulfinyl group, and 3-methyl. Phenylsulfinyl group, 3-chlorophenylsulfinyl group, 3-trifluoromethylphenylsulfinyl group, 3-cyanophenylsulfinyl group, 3-nitrophenylsulfinyl group, 4-methylphenylsulfinyl group, 4-fluorophenylsulfinyl group, 4-cyano Substituted or unsubstituted phenylsulfinyl group such as phenylsulfinyl group, 4-methoxyphenylsulfinyl group, 4-dimethylaminophenylsulfinyl group; 1-naphthyls Finiru group, 2-naphthylsulfinyl substituted or unsubstituted naphthylsulfinyl group such as Le group; and the like. 6-25 are preferable and, as for carbon number of an aryl sulfinyl group, 6-15 are more preferable.

  Examples of the heteroaryl group include thienyl group, thiopyranyl group, isothiochromenyl group, pyrrolyl group, imidazolyl group, pyrazolyl group, pyridyl group, pyralidinyl group, pyrimidinyl group, pyridazinyl group, thiazolyl group, isothiazolyl group, furanyl group, A pyranyl group etc. are mentioned. 2-20 are preferable and, as for carbon number of a heteroaryl group, 3-15 are more preferable.

  Examples of the amide group (-NHCOR) include those in which R is a linear or branched alkyl group having 1 to 20 carbon atoms, an aryl group, an aralkyl group, a heteroaryl group, or a halogenated hydrocarbon group. .

Examples of the sulfonamide group (—NHSO ₂ R) include those in which R is a linear or branched alkyl group having 1 to 20 carbon atoms, an aryl group, an aralkyl group, a heteroaryl group, or a halogenated hydrocarbon group. Is mentioned.

  Examples of the halogenoalkyl group include monohalogenoalkyl groups such as a fluoromethyl group, a 3-fluoropropyl group, a 3-chloropropyl group, a 6-fluorohexyl group, and a 4-fluorocyclohexyl group; and a dihalogeno group such as a dichloromethyl group. Alkyl group; 1,1-dihydro-perfluoroethyl group, 1,1-dihydro-perfluoro-n-propyl group, 1,1-dihydro-perfluoro-n-butyl group, 2,2-bis (trifluoro Methyl) propyl group, alkyl group having a trihalomethyl unit such as 2,2,2-trichloroethyl group; trifluoromethyl group, perfluoroethyl group, perfluoro-n-pentyl group, perfluoro-n-hexyl group, etc. Perhalogenoalkyl group; and the like. 1-20 are preferable, as for carbon number of a halogenoalkyl group, More preferably, it is 1-10, More preferably, it is 1-5. The halogen of the halogenoalkyl group is preferably a fluorine atom, a chlorine atom or a bromine atom, and particularly preferably a fluorine atom.

  Examples of the halogeno group include a fluoro group, a chloro group, a bromo group, and an iodo group.

  Among the above, the organic group or polar functional group represented by Y is preferably an alkyl group, an alkoxy group, a halogeno group, an aryl group, an alkoxycarbonyl group (ester group), an amide group, a sulfonamide group, or a hydroxyl group. A group or a hydroxyl group is more preferable, and this facilitates enhancing the solvent solubility of the oxocarbon-based compound. In this case, 1-5 are preferable, as for carbon number of an alkyl group, More preferably, it is 1-3, More preferably, it is 1-2. Specifically, preferred examples of the organic group or polar functional group represented by Y include a methyl group, an ethyl group, and a hydroxyl group.

  When the number n of substituents Y is 2 or more and a plurality of Y are present, each Y may be the same or different. When n is 2 or more, a plurality of Y may be bonded to different carbon atoms, or two Y may be bonded to one carbon atom.

  A hydrogen atom, an organic group or a polar functional group is bonded to the carbon atom at the β-position of the pyrrole ring constituting a part of the ring A (X in the formula (3)). In the formula (3), examples of the organic group and the polar functional group of X include the organic groups and polar functional groups exemplified for the substituent Y. Among them, as X in the formula (3), a hydrogen atom, an alkyl group, an alkoxycarbonyl group, or an aryl group is preferable, and an alkyl group or an aryl group is more preferable. This makes it easy to improve the solvent solubility of the oxocarbon compound. . In this case, the number of carbon atoms of the alkyl group is preferably 1 to 6 if it is a linear or branched alkyl group, more preferably 1 to 4, and 4 to 7 if it is an alicyclic alkyl group. Preferably, it is 5-6. 6-10 are preferable and, as for carbon number of an aryl group, More preferably, it is 6-8. When X is an alkyl group or an aryl group, a methyl group, an ethyl group, an isopropyl group, an isobutyl group, a t-butyl group, a cyclopentyl group, a cyclohexyl group, a phenyl group and the like are preferable.

  In formula (3), ring B represents an aromatic hydrocarbon ring, an aromatic heterocycle, or a condensed ring containing these ring structures, which may have a substituent. An aromatic hydrocarbon ring is a ring structure composed of carbon atoms and hydrogen atoms and having aromaticity, such as a benzene ring, naphthalene ring, phenanthrene ring, anthracene ring, fluoranthene ring, cyclotetradecaheptaene ring, etc. Is mentioned. The aromatic hydrocarbon ring may have only one ring structure or may be a condensation of two or more ring structures. An aromatic heterocyclic ring has one or more atoms selected from N (nitrogen atom), O (oxygen atom) and S (sulfur atom) in the ring structure and has aromaticity, for example, a furan ring. Thiophene ring, pyrrole ring, pyrazole ring, oxazole ring, thiazole ring, imidazole ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, purine ring, pteridine ring and the like. The aromatic heterocycle may have only one ring structure, or may be a condensation of two or more ring structures. The condensed ring containing these ring structures has a structure in which an aromatic hydrocarbon ring and an aromatic heterocycle are condensed. For example, an indole ring, an isoindole ring, a benzimidazole ring, a quinoline ring, a benzopyran ring , Acridine ring, xanthene ring, carbazole ring and the like.

  Ring B contains 12 or more π electrons. Therefore, the aromatic hydrocarbon ring, the aromatic heterocycle, and the condensed ring containing these ring structures exemplified above are appropriately combined as necessary so that the number of π electrons is 12 or more. Shall be formed. If the number of π electrons contained in ring B is 12 or more, coupled with the inclusion of ring A in the structural unit represented by formula (3), the oxocarbon-based compound effectively emits light in the wavelength range exceeding about 800 nm. Can be absorbed. For example, by setting the number of π electrons contained in ring B to 12 or more, the wavelength of the oxocarbon compound having a 50% transmittance (however, on the longer wavelength side than the maximum absorption wavelength) can be set to 800 nm or more. The number of π electrons contained in ring B is preferably 14 or more, and more preferably 16 or more. The upper limit of the number of π electrons contained in ring B is not particularly limited, but considering the optical performance required as a cut filter for night vision cameras, the ease of production of oxocarbon compounds, and solvent solubility, The number of π electrons contained is preferably 26 or less, more preferably 24 or less, and even more preferably 22 or less. The number of π electrons contained in ring B is a number including π electrons of a carbon-carbon bond shared by ring B and the pyrrole ring.

  Ring B may have a substituent, and examples of the substituent include the substituents exemplified for the substituent Y. Examples of the substituent bonded to ring B include an alkyl group (preferably a linear or branched alkyl group having 1 to 4 carbon atoms), an aryl group, an alkoxy group (preferably an alkoxy group having 1 to 4 carbon atoms), an alkylthio group. Electron donating groups such as groups (preferably having 1 to 2 carbon atoms), heteroaryl groups, amino groups, amide groups, sulfonamido groups, hydroxyl groups, thiol groups, benzothiazole groups; halogeno groups (preferably fluoro groups, Chloro group, bromo group), halogenoalkyl group (preferably a perhalogenoalkyl group having 1 to 3 carbon atoms), cyano group, alkoxycarbonyl group (ester group), carboxy group (carboxylic acid group), carboxylic acid ester group, carvone Electron withdrawing groups such as acid amide groups, sulfo groups (sulfonic acid groups), and nitro groups are preferred. Among these, an electron withdrawing group is more preferable, and a halogeno group is particularly preferable. Ring B may not have a substituent. When the ring B has a substituent, the number is preferably 1 to 3, more preferably 1 to 2, and still more preferably 1.

Ring B is an ethylene-containing group represented by the formula (4): —CH═CH—R ^a1 (wherein R ^a1 represents an aliphatic hydrocarbon group, an aryl group or a heteroaryl group) It is also preferable to have an imine-containing group represented by the formula (5): ^—CH═N —R ^a2 (in the formula (5), R ^a2 represents an amino group which may have a substituent). .

In formula (4), the aliphatic hydrocarbon group for R ^a1 may be either saturated or unsaturated, but is preferably unsaturated. Examples of such an aliphatic hydrocarbon group include a group having a repeating unit represented by — (CH═CH) _k — (k is an integer of 1 to 10, preferably an integer of 1 to 5). Preferably, a vinyl group is mentioned, for example. As an aliphatic hydrocarbon group, a C1-C20 thing is preferable, for example, More preferably, a C1-C10 thing is mentioned. In the formula (4), examples of the aryl group and heteroaryl group represented by R ^a1 include the aryl group and heteroaryl group exemplified for the substituent Y.

In formula (5), the amino group of R ^a2 may be substituted or unsubstituted. Examples of the amino group having a substituent include a monoalkylamino group, a dialkylamino group, a monoarylamino group, a diarylamino group, and a monoalkylmonoarylamino group. Examples of the alkyl group and aryl group bonded to the amino group of R ^a2 include the alkyl group and aryl group exemplified for the substituent Y.

  In the oxocarbon-based compound of the present invention, as described above, the structural unit represented by the formula (3) bonded to the squarylium skeleton or the croconium skeleton has a ring A and a ring B, and π contained in the ring B Since the number of electrons is 12 or more, π electrons spread over a wide range of the molecule, the absorption wavelength is shifted by a long wavelength, and light in a wavelength region exceeding about 800 nm can be effectively absorbed. Therefore, by applying the oxocarbon-based compound of the present invention to the optical filter of the night vision imaging device, the incident angle dependency of the optical characteristics in the near infrared region (for example, 800 to 1000 nm) is reduced, and the viewing angle Can be improved. In addition, since the oxocarbon-based compound can increase the transmittance in the visible light region, even if it is applied to a general imaging device that receives visible light, a change in the color of the image can be suppressed. For example, some phthalocyanine compounds have a maximum absorption wavelength around 800 nm, but since phthalocyanine compounds have an absorption peak in the wavelength region near 350 nm, the optical filter containing the phthalocyanine compound is colored green. Therefore, application in the visible light region is limited. However, the oxocarbon-based compound of the present invention can be suitably applied to an imaging device such as a daytime and night surveillance camera.

  The oxocarbon compound of the present invention can be produced, for example, by reacting a pyrrole ring-containing compound represented by the following formula (6) with squaric acid or croconic acid. In the following formula (6), ring A, ring B, X, Y and n have the same meaning as in the above formula (3).

  The pyrrole ring-containing compound used as a raw material can be synthesized by appropriately adopting known synthetic techniques. For example, when ring A is cyclohexene, ring B is a fluoranthene ring, and n = 0, it can be synthesized by reaction of fluoranthenyl hydrazine hydrochloride with (2-substituted) cyclohexanone. At this time, by introducing a substituent that becomes X into the 2-position of cyclohexanone, or by modifying the 3-position, 4-position, 5-position, and 6-position of cyclohexanone with the substituent that becomes Y, any X and Y can be added. Substituents can be introduced. The structure of ring B can be altered by using other aromatic hydrazine hydrochlorides instead of fluoranthenyl hydrazine hydrochloride. The number of members of ring A can be changed by using (2-substituted) cyclohexanone with another (2-substituted) cycloalkanone having a different number of ring-constituting carbon atoms. A pyrrole ring-containing compound can also be synthesized by the synthetic method described in the following paper: Sajjadifar et al., “New 3H-Indole Synthesis by Fischer's Method. Part I”, Molecules, Vol. 15, p. 2491-2498 (2010).

  In the reaction of squaric acid or croconic acid with a pyrrole ring-containing compound, the amount of the pyrrole ring-containing compound used is preferably 1 mol or more, more preferably 1.5 fold mol or more, relative to squaric acid or croconic acid. More preferably, it is 2 times mol or more, and 5 times mol or less is preferable, More preferably, it is 4 times mol or less, More preferably, it is 3 times mol or less.

  The reaction between squaric acid or croconic acid and the pyrrole ring-containing compound is preferably carried out in the presence of a solvent. Solvents that can be used include, for example, chlorinated hydrocarbons such as chloroform and methylene chloride; aromatic hydrocarbons such as benzene, toluene, xylene, and trimethylbenzene; THF, dioxane, cyclopentyl methyl ether, diisopropyl ether, diethyl ether, and the like. Ethers; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; alcohols such as methanol, ethanol, propanol, and butanol; amides such as dimethylformamide and dimethylacetamide; These solvents may use only 1 type and may use 2 or more types together.

  The use amount (total) of the solvent is preferably 1 mass times or more, more preferably 5 mass times or more, further preferably 10 mass times or more, and preferably 100 mass times or less with respect to squaric acid or croconic acid.

  In the reaction of squaric acid or croconic acid with a pyrrole ring-containing compound, the reaction temperature may be appropriately set, for example, preferably 30 ° C or higher, more preferably 60 ° C or higher, further preferably 80 ° C or higher, and 170 ° C or lower. Preferably, 140 degrees C or less is more preferable. The reaction is preferably performed in a reflux state. The reaction time is not particularly limited and may be appropriately set according to the progress of the reaction. For example, 0.5 hour or more is preferable, 1 hour or more is more preferable, 24 hours or less is preferable, and 12 hours or less is preferable. More preferred. The atmosphere during the reaction is preferably an inert gas (nitrogen, argon, etc.) atmosphere.

  The squarylium compound can be synthesized by appropriately adopting a known synthesis method in which a pyrrole ring-containing compound and squaric acid are reacted. For example, squarylium compounds can be synthesized by the synthesis method described in the following paper: Serguei Miltsov et al. “New Cyanine Dyes: Norindosquarocyanines”, Tetrahedron Letters, Vol. 40, Issue 21, p.4067-4068 ( 1999).

  The method for synthesizing the croconium compound is not particularly limited, but the croconium compound can be synthesized by appropriately adopting a known synthesis method for reacting a pyrrole ring-containing compound with croconic acid. For example, a croconium compound can be synthesized by a method described in JP-A No. 2002-286931, JP-A No. 2007-31644, JP-A No. 2007-31645, and JP-A No. 2007-169315.

  The oxocarbon-based compound obtained by the above reaction can be appropriately purified by known purification means such as filtration, silica gel column chromatography, alumina column chromatography, sublimation, recrystallization, and crystallization as necessary. The chemical structure of the obtained oxocarbon-based compound can be analyzed by a known analysis method such as mass spectrometry, single crystal X-ray structure analysis, Fourier transform infrared spectroscopy, or nuclear magnetic resonance spectroscopy.

  The oxocarbon compound of the present invention can be mixed with a resin component to form a resin composition. The resin composition of the present invention comprises the oxocarbon compound of the present invention and a resin component. Since the resin composition of the present invention contains the oxocarbon-based compound of the present invention, it can effectively absorb light in the wavelength region of around 800 nm. The resin composition of the present invention can be suitably applied to an optical filter of an imaging device for night vision by being formed into a film, thereby allowing incidence of optical characteristics on the short wavelength side in the near infrared region. An optical filter with reduced angle dependency and improved viewing angle can be obtained. Moreover, a night vision glass etc. can also be produced by forming the resin composition into a plate shape. In the present invention, “for night vision” does not mean dedicated to night vision, but includes those that can be used under visible light, for example.

  The oxocarbon-based compound contained in the resin composition may be a squarylium compound, a croconium compound, or both. The oxocarbon compound contained in the resin composition may be only one type or two or more types.

  Although the oxocarbon-based compound of the present invention can be regarded as a kind of dye, the resin composition of the present invention may contain another dye together with the oxocarbon-based compound of the present invention. Examples of the dye that may be contained in the resin composition include a squarylium dye and a croconium dye other than the oxocarbon compound of the present invention, and copper (for example, Cu (II)) or zinc (for example, a central metal ion). , Zn (II)) and the like cyclic tetrapyrrole dyes (porphyrins, chlorins, phthalocyanines, cholines, etc.), cyanine dyes, quaterylene dyes, naphthalocyanine dyes, nickel complex systems Examples thereof include dyes, copper ion dyes, diimmonium dyes, subphthalocyanine dyes, xanthene dyes, azo dyes, and dipyrromethene dyes. These other pigments may be used alone or in combination of two or more.

  When the resin composition of the present invention also contains other dyes, the content of the other dyes is preferably 60% by weight or less with respect to 100% by weight in total of the oxocarbon compound of the present invention and the other dyes, More preferably, it is 40 mass% or less, More preferably, it is 20 mass% or less, Especially preferably, it is not containing other pigment | dye substantially.

  The content of the oxocarbon-based compound of the present invention in the resin composition is preferably 0.01% by mass or more in 100% by mass of the solid content of the resin composition from the viewpoint of exerting desired optical characteristics. 0.3 mass% or more is more preferable, and 1 mass% or more is further more preferable. Moreover, from the point which improves the moldability, film formability, etc. of the resin composition, the content of the oxocarbon-based compound of the present invention in the resin composition is 25% by mass or less in 100% by mass of the solid content of the resin composition. Is preferable, 20 mass% or less is more preferable, and 15 mass% or less is further more preferable. When the resin composition also contains other dyes, the total content of the oxocarbon compound of the present invention and the other dyes is preferably in the above range.

  A known resin can be used as the resin component contained in the resin composition. As the resin component, those having high transparency and capable of dissolving or dispersing the oxocarbon compound of the present invention are preferable. When other dyes are used in combination, the resin component is preferably one that can also dissolve or disperse other dyes. By selecting such a resin component, it is possible to achieve both high transmittance in the wavelength range desired to be transmitted and high absorbency in the wavelength range desired to be blocked.

  The resin component is not only a resin that has been completely polymerized, but also a resin raw material (including a precursor of the resin, a raw material of the precursor, a monomer constituting the resin, and the like), and when the resin composition is molded In addition, those which are incorporated into the resin by polymerization reaction or crosslinking reaction can also be used. In the present invention, any resin is included in the resin component. In the latter case, the structure of the oxocarbon-based compound is caused by unreacted substances, reactive terminal functional groups, ionic groups, catalysts, acid / basic groups, etc. present in the reaction solution obtained by the polymerization reaction. Some or all of them may be decomposed. Therefore, when there is such a concern, it is desirable to form a resin composition by blending an oxocarbon-based compound with a resin that has been completely polymerized.

  Examples of the resin component include (meth) acrylic resin, (meth) acrylic urethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyolefin resin (for example, polyethylene resin, polypropylene resin), polycycloolefin resin, Melamine resin, urethane resin, styrene resin, polyvinyl acetate, polyamide resin (for example, nylon), aramid resin, polyimide resin, polyamideimide resin, alkyd resin, phenol resin, epoxy resin, polyester resin Resin (for example, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), etc.), butyral resin, polycarbonate resin, polyether resin, ABS resin (acrylonitrile butadiene styrene resin), AS resin (acrylic resin) Nitrile-styrene copolymer), silicone resin, modified silicone resin (for example, (meth) acrylic silicone resin, alkylpolysiloxane resin, silicone urethane resin, silicone polyester resin, silicone acrylic resin, etc.), fluorine resin (for example, , Fluorinated aromatic polymer, polytetrafluoroethylene (PTFE), perfluoroalkoxy fluororesin (PFA), fluorinated polyaryletherketone (FPEK), fluorinated polyimide (FPI), fluorinated polyamic acid (FPAA), fluorine Polyether nitrile (FPEN) and the like.

  The resin component preferably has high transparency, which makes it easy to suitably apply the resin composition to optical applications. For example, 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 still more preferably 85% or more. The upper limit of the total light transmittance of the resin component is not particularly limited, and the total light transmittance may be 100% or less, for example, 95% or less. The total light transmittance is measured based on JIS K 7105.

  The resin component preferably has a high glass transition temperature (Tg), whereby the heat resistance of the resin composition and various molded articles obtained therefrom can be increased. For example, the glass transition temperature of the resin component is preferably 110 ° C. or higher, more preferably 120 ° C. or higher, and further preferably 130 ° C. or higher. Although the upper limit of the glass transition temperature of a resin component is not specifically limited, For example, 380 degrees C or less is preferable from the point which ensures the moldability of a resin composition.

  The resin composition may be a thermoplastic resin composition that can be used for molding such as injection molding, or may be a resin composition that is made into a paint so that it can be applied by a spin coating method, a solvent casting method, or the like. Good.

  When the resin composition is a thermoplastic resin composition, a molded product can be obtained by subjecting the resin composition to injection molding, extrusion molding, vacuum molding, compression molding, blow molding, or the like. In this method, a thermoplastic resin is used as a resin component, an oxocarbon-based compound is blended in the thermoplastic resin, and a molded product is obtained by heat molding. For example, an oxocarbon compound may be added to the base resin powder or pellets, heated to about 150 ° C. to 350 ° C., dissolved, and then molded. The shape of the molded product is not particularly limited, and examples thereof include a sheet molded product such as a film having a thickness of 200 μm or less, a plate-shaped product having a thickness of more than 200 μm, and a molded product such as a deformed product. Moreover, when kneading | mixing resin, you may add the additive used for normal resin shaping | molding, such as a ultraviolet absorber and a plasticizer.

  When the resin composition is a coated resin composition, a liquid or paste resin composition containing an oxocarbon-based compound is applied on a transparent substrate (for example, a resin plate, a film, a glass plate, etc.). By doing so, it is possible to form a planar molded body such as a film having a thickness of 200 μm or less or a plate-like material having a thickness of more than 200 μm. Examples of the resin composition formed into a paint include those obtained by dissolving an oxocarbon-based compound in a solvent (solvent) containing a resin, or an emulsion of a resin by atomizing the oxocarbon-based compound to several μm or less. What was dispersed in the inside etc. are mentioned.

  When the resin composition is a resin composition formed into a paint, it is preferable to use a solvent-soluble resin that is soluble in an organic solvent as the resin component. The solvent-soluble resin means a resin that is soluble in an organic solvent, and a resin that dissolves 1 part by mass or more with respect to 100 parts by mass of the organic solvent is preferable. If the resin component is a solvent-soluble resin, a thin film can be easily produced by forming a film by, for example, spin coating or solvent casting. Solvent-soluble resins are reactive groups that can undergo a crosslinking reaction (curing reaction) (for example, ring-opening polymerizable groups such as epoxy groups, oxetane rings, and ethylene sulfide groups, acrylic groups, methacrylic groups, vinyl groups, and the like). It may have a radical curable group and / or an addition curable group.

  Examples of the solvent-soluble resin include polyimide resin, polyamideimide resin, fluorinated aromatic polymer, (meth) acrylic resin, polyamide resin, aramid resin, polysulfone resin, cycloolefin resin, epoxy resin, urethane resin, Examples thereof include phenolic resins. Among these, polyimide resin, polyamideimide resin, fluorinated aromatic polymer, (meth) acrylic resin, polysulfone resin, cycloolefin resin, and epoxy resin are preferable from the viewpoint of excellent light resistance.

  Polyimide resin is a polymer containing an imide bond in the repeating unit of the main chain. For example, tetracarboxylic dianhydride and diamine are polymerized to obtain polyamic acid, which is dehydrated and cyclized (imidized). Can be manufactured. As the polyamide resin, it is preferable to use an aromatic polyimide in which aromatic rings are connected by an imide bond. Polyimide resins include, for example, Kapton (registered trademark) manufactured by DuPont, Aurum (registered trademark) manufactured by Mitsui Chemicals, Meldin (registered trademark) manufactured by Saint-Gobain, and TPS (registered trademark) TI3000 series manufactured by Toray Plastic Seiko Co., Ltd. Etc. can be used.

  Polyamideimide resin is a polymer containing an amide bond and an imide bond in the repeating unit of the main chain. As the polyamideimide resin, for example, Torlon (registered trademark) manufactured by Solvay Advanced Polymers, Viromax (registered trademark) manufactured by Toyobo, TPS (registered trademark) TI5000 series manufactured by Toray Plastic Seiko Co., Ltd., and the like can be used.

  The fluorinated aromatic polymer includes an aromatic ring having one or more fluorine atoms and at least one bond selected from the group consisting of an ether bond, a ketone bond, a sulfone bond, an amide bond, an imide bond, and an ester bond. A polymer having a unit, and among these, a polymer essentially including a repeating unit containing an aromatic ring having one or more fluorine atoms and an ether bond is preferable. As the fluorinated aromatic polymer, for example, those described in JP 2008-181121 A can be used.

  The (meth) acrylic resin is a polymer having a repeating unit derived from (meth) acrylic acid or a derivative thereof, for example, a repeating unit derived from a (meth) acrylic acid ester such as a poly (meth) acrylic acid ester resin. The resin which has is used preferably. The (meth) acrylic resin preferably has a ring structure in the main chain, for example, a carbonyl group-containing ring structure such as a lactone ring structure, a glutaric anhydride structure, a glutarimide structure, a maleic anhydride structure, or a maleimide ring structure; oxetane Examples include carbonyl group-free ring structures such as a ring structure, an azetidine ring structure, a tetrahydrofuran ring structure, a pyrrolidine ring structure, a tetrahydropyran ring structure, and a piperidine ring structure. Examples of (meth) acrylic resins having a carbonyl group-containing ring structure include those described in JP-A No. 2004-168882, JP-A No. 2008-179777, International Publication No. 2005/54311, JP-A No. 2007-31537, and the like. Those described can be used.

The polysulfone resin is a polymer having a repeating unit containing an aromatic ring, a sulfonyl group (—SO ₂ —), and an oxygen atom. As the polysulfone resin, for example, SUMIKAEXCEL (registered trademark) PES3600P or PES4100P manufactured by Sumitomo Chemical Co., Ltd., UDEL (registered trademark) P-1700 manufactured by Solvay Specialty Polymers Co., Ltd., or the like can be used.

  The cycloolefin resin is a polymer obtained by polymerizing a cycloolefin as at least a part of the monomer component, and is not particularly limited as long as it has an alicyclic structure in a part of the main chain. Examples of the cycloolefin-based resin include Topas (registered trademark) manufactured by Polyplastics, Appel (registered trademark) manufactured by Mitsui Chemicals, ZEONEX (registered trademark) and ZEONOR (registered trademark) manufactured by Nippon Zeon, and JSR Arton (registered trademark) or the like made by the manufacturer can be used.

  The epoxy resin is a resin that can be cured by crosslinking an epoxy compound (prepolymer) in the presence of a curing agent or a curing catalyst. Examples of the epoxy compound include aromatic epoxy compounds, aliphatic epoxy compounds, alicyclic epoxy compounds, hydrogenated epoxy compounds, and the like, for example, fluorene epoxy (Ogsol (registered trademark) PG-100) manufactured by Osaka Gas Chemical Company. Bisphenol A type epoxy compound (JER (registered trademark) 828EL) manufactured by Mitsubishi Chemical Corporation, hydrogenated bisphenol A type epoxy compound (JER (registered trademark) YX8000), alicyclic liquid epoxy compound (celloxide (registered trademark) manufactured by Daicel Corporation) Trademark) 2021P) and the like can be used.

  The resin composition may contain a solvent (solvent). For example, when the resin composition is a resin composition that has been made into a paint, application of the resin composition is facilitated by including the solvent. become. As the solvent, an organic solvent is preferably used. For example, ketones such as methyl ethyl ketone (2-butanone), methyl isobutyl ketone (4-methyl-2-pentanone), and cyclohexanone; PGMEA (2-acetoxy-1-methoxypropane) ), Glycol derivatives such as ethylene glycol mono-n-butyl ether, ethylene glycol monoethyl ether, ethylene glycol ethyl ether acetate (ether compounds, ester compounds, ether ester compounds, etc.); amides such as N, N-dimethylacetamide; acetic acid Esters such as ethyl, propyl acetate and butyl acetate; pyrrolidones such as N-methyl-pyrrolidone (specifically 1-methyl-2-pyrrolidone and the like); aromatic hydrocarbons such as toluene and xylene; cyclohexane, Aliphatic hydrocarbons such as heptane; tetrahydrofuran, dioxane, diethyl ether, ethers such as Djibouti ether; and the like.

  As content of a solvent, it is preferable that it is 50 mass% or more in 100 mass% of resin compositions, 70 mass% or more is more preferable, less than 100 mass% is preferable, and 95 mass% or less is more preferable. By adjusting the content of the solvent within such a range, it becomes easy to obtain a resin composition having a high oxocarbon compound concentration.

  It should be noted that amides such as N, N-dimethylacetamide are preferably used in a smaller amount because they may decompose the oxocarbon-based compound. Therefore, the content of amides is preferably 60% by mass or less, more preferably 40% by mass or less, further preferably 20% by mass or less, still more preferably 5% by mass or less, and further preferably 0% by mass in 100% by mass of the resin composition. % Is particularly preferred (ie does not include amides).

  The resin composition may contain, for example, a compound (ultraviolet absorber) having an absorption ability in a wavelength range of 350 to 400 nm. Due to the presence of these compounds, it is possible to suppress degradation of the resin composition caused by light in the wavelength range of 350 to 400 nm. When a compound having an absorption ability in the wavelength range of 350 to 400 nm is used in combination, as a compound having an absorption ability in the wavelength range of 350 to 400 nm, for example, TINUVIN (registered trademark) series manufactured by BASF can be used.

  The resin composition of the present invention includes, as necessary, a plasticizer, a surfactant, a dispersant, a surface tension adjuster, a viscosity adjuster, an antifoaming agent, a preservative, a specific resistance adjuster, an adhesion improver, and the like. Various additives may be included.

  The resin composition of the present invention can be preferably used as a resin composition for forming a filter used in various applications such as an optical device application, a display device application, a machine part, and an electric / electronic part. The resin composition of the present invention can be suitably applied particularly to an optical filter of a night vision image sensor. According to the optical filter of the present invention, an optical filter suitable for a night vision imaging device in which the dependency of the optical characteristics in the near infrared region (for example, 800 to 1000 nm) on the incident angle is reduced and the viewing angle is improved. be able to.

  Such a filter can be obtained by molding the resin composition of the present invention into a planar shape by a known method such as injection molding, extrusion molding, vacuum molding, compression molding, blow molding, or solvent casting. The obtained planar molded body may form a filter from a single-layer resin molded body, or may be integrated with a support to form a filter.

  The filter integrated with the support is, for example, the resin composition, the surface of the support (or the surface of the other layer in the case of having another layer such as a binder layer between the support and the resin layer). ) By spin coating or solvent casting, and dried or cured. Moreover, you may form a filter by thermocompression-bonding the planar molded object formed from the resin composition with respect to the support body.

  The resin layer formed from the resin composition may be provided only on one side of the support, or may be provided on both sides. Although the thickness of the resin layer is not particularly limited, it is preferably 0.5 μm or more, more preferably 1 μm or more, and preferably 15 μm or less, from the viewpoint of securing desired near-infrared cut performance and realizing thinning, It is more preferably 10 μm or less, further preferably 5 μm or less, and particularly preferably 3 μm or less.

  As the support, a transparent substrate such as a resin plate, a resin film, or a glass plate is preferably used. As the resin plate or resin film used for the support, for example, those formed from the resin components described above are preferably used. When a glass plate is used as the support, it is preferable to provide a binder layer formed of, for example, a silane coupling agent between the support and the resin layer. Thereby, the adhesiveness of a resin layer and a glass support body can be improved. In addition, even if it includes a silane coupling agent as an adhesive improvement agent in the resin composition which forms a resin layer, the adhesiveness of a resin layer and a glass support body can be improved.

  When forming an optical filter from the resin composition of the present invention, the optical filter has a layer having antireflection and antiglare properties, a layer having anti-scratch performance, and other functions for reducing reflection of a fluorescent lamp or the like. You may have the transparent substrate which has.

  In the optical filter of the present invention, it is preferable that a near-infrared reflective film (for example, a reflective film having a wavelength region of 700 to 800 nm) is provided on the resin layer. It is preferable that the near-infrared reflective film is provided on the light incident side with respect to the resin layer. As a near-infrared reflective film, an aluminum vapor-deposited film, a noble metal thin film, a resin film in which metal oxide fine particles mainly containing indium oxide and containing a small amount of tin oxide are dispersed, a high refractive index material layer and a low refractive index material layer, A dielectric multilayer film or the like in which the layers are alternately stacked can be used. If the optical filter is provided with a near-infrared reflective film, the near-infrared light can be further cut from the transmitted light of the optical filter. Note that the near-infrared reflective film may include an ultraviolet reflective function simultaneously (same film).

  Among the near-infrared reflective films, it is preferable to use a dielectric multilayer film in which high refractive index material layers and low refractive index material layers are alternately laminated. As a material constituting the high refractive index material layer, a material having a refractive index of 1.7 or more can be used, and a material having a refractive index range of 1.7 to 2.5 is usually selected. Examples of the material 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; silicon nitride Nitrides such as oxides, mixtures of the nitrides and the like, and those doped with metals or carbon such as aluminum or copper (for example, tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO)), etc. Can be mentioned. As a material constituting the low refractive index material layer, a material having a refractive index of 1.6 or less can be used, and a material having a refractive index range of 1.2 to 1.6 is usually selected. Examples of the material constituting the low refractive index material layer include silicon dioxide (silica), alumina, lanthanum fluoride, magnesium fluoride, and aluminum hexafluoride sodium.

  The optical filter of the present invention is particularly preferably used for a night vision imaging device. The image sensor is also referred to as a solid-state image sensor or an image sensor chip, and is an electronic component that converts light from a subject into an electrical signal or the like and outputs the electrical signal. The imaging element usually has a detection element (sensor) such as a charge coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS), and may have a lens. The imaging device for night vision can be used not only for surveillance cameras, but also for general imaging devices such as mobile phone cameras, digital cameras, in-vehicle cameras, display devices (LEDs, etc.). it can. The imaging device includes one or more of the optical filters of the present invention, and may further have other filters (for example, a visible light cut filter, an infrared cut filter, an ultraviolet cut filter, etc.) as necessary.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited by the following examples, and is implemented with appropriate modifications within a range that can meet the purpose described above and below. Any of these may be included in the technical scope of the present invention.

(1) Synthesis of Compound (1-1) Synthesis Example 1 (Synthesis of squarylium compound 1)
Into a 300 mL four-necked flask, 60 mL of hydrochloric acid was put, the temperature in the flask was cooled to -10 ° C. or lower, and while keeping the temperature in the flask not exceeding 0 ° C., 5.13 g (0.1. 024 mol) was added and dissolved. After the exotherm subsided, a solution in which 1.63 g (0.024 mol) of sodium nitrite was dissolved in 11 g of distilled water was added dropwise over 1 hour while maintaining the temperature in the flask at −10 ° C. or lower. After completion of the dropwise addition, a solution obtained by further dissolving 26.63 g (0.118 mol) of tin chloride dihydrate in 27 mL of hydrochloric acid was added dropwise over 1 hour so that the temperature in the flask did not exceed 0 ° C. Proceeded. After completion of the reaction, the cake obtained by filtration was dried using a vacuum dryer at 60 ° C. for 12 hours to obtain 5.5 g of fluoranthene-3-hydrazine hydrochloride. The yield based on 3-aminofluoranthene was 87.2 mol%.

  Next, 2.55 g (0.01 mol) of fluoranthene-3-hydrazine hydrochloride obtained above, 1.07 g (0.01 mol) of 2-methylcyclohexanone, and 36 g of 1-butanol as a solvent were added to a 50 mL four-necked flask. The mixture was reacted at 60 ° C. for 4 hours while stirring using a magnetic stirrer under nitrogen flow (5 mL / min) to obtain a pyrrole ring-containing compound. After completion of the reaction, the solution containing the pyrrole ring-containing compound was cooled to room temperature and filtered, and the obtained filtrate was transferred to a 200 mL four-necked flask. Add 0.55 g (0.005 mol) squaric acid and 36 g toluene, stir using a magnetic stirrer under nitrogen flow (5 mL / min), and elute water using a Dean-Stark device. While removing, the reaction was allowed to proceed for 6 hours under reflux conditions. After completion of the reaction, the obtained reaction solution is concentrated with an evaporator, the obtained solid is purified by column chromatography (developing solvent: chloroform), and the purified isolate is further recrystallized in methanol to obtain the target. 0.4 g of squarylium compound 1 was obtained. The yield based on squaric acid was 12.1 mol%.

  The obtained compound was identified by a mass spectrometer (“LCMS-2020” manufactured by Shimadzu Corporation, M / Z = 50-2000, positive / negative simultaneous scan). Specifically, about 1 mg of the obtained compound was applied and adhered to a glass rod, ionized directly with an ionization unit (DART) (“DART-OS” manufactured by Shimadzu Corporation, heater temperature 500 ° C.), and mass spectrometry was performed. By introducing it into the meter, the mass spectrum of the compound was measured.

(1-2) Synthesis Example 2 (Synthesis of comparative squarylium compound 1)
The comparison shown in Table 1 was carried out in the same quantitative relationship and method as in Synthesis Example 1 except that 2.00 g (0.01 mol) of 1-naphthylhydrazine hydrochloride was used instead of fluoranthene-3-hydrazine hydrochloride. 0.4 g of squarylium compound 1 was obtained. The yield based on squaric acid was 23.1 mol%.

(1-3) Synthesis Example 3 (Synthesis of comparative squarylium compound 2)
Comparative squarylium compound 2 shown in Table 1 was obtained by the synthesis method described in Tetrahedron Letters, Vol. 40, p. 4067-4068 (1999).

(1-4) Synthesis Example 4 (Synthesis of Comparative Phthalocyanine Compound 1)
Comparative phthalocyanine compound 1 shown in Table 1 was obtained by the synthesis method described in JP2013-241563A.

(2) Evaluation Using a spectrophotometer (“UV-1800” manufactured by Shimadzu Corporation), the absorption spectrum (transmission spectrum) of each compound in a chloroform solvent was measured at a measurement pitch of 1 nm, and the light at a wavelength of 200 to 1100 nm was measured. The transmittance was determined. For each compound, the wavelength at which absorption is maximum in the wavelength range of 600 to 850 nm (maximum absorption wavelength λmax), the wavelength at which the transmittance is 50% longer than the maximum absorption wavelength (% T50), and transmission at a wavelength of 400 nm The percentages (% T (400 nm)) were determined, and the results are summarized in Table 2. The transmission spectra of squarylium compound 1, comparative squarylium compound 1, and comparative phthalocyanine compound 1 are shown in FIG.

  In the squarylium compound 1, the number of π electrons in ring B was 16, the maximum absorption wavelength λmax was 788.0 nm, and the wavelength% T50 at which the transmittance was 50% was 822.0 nm. The squarylium compound 1 can absorb light in a wavelength range exceeding about 800 nm (800 to 850 nm), and exhibits a sufficient function as an optical filter of an imaging device for night vision. On the other hand, the comparative squarylium compound 1 has 10 π electrons in the ring B, the comparative squarylium compound 2 has 6 π electrons, and the wavelength% T50 at which the transmittance is 50% is 772.5 nm and 673, respectively. 0.0 nm. These squarylium compounds hardly absorbed light in the wavelength region exceeding about 800 nm. When the relationship between the number of π electrons in ring B of squarylium compound 1 and comparative squarylium compounds 1 and 2 and the wavelength of% T50 is plotted on a graph and approximated by a polynomial, if the number of π electrons in ring B is 12 or more,% T50 It can be seen that the wavelength of is about 800 nm or more.

  The comparative phthalocyanine compound 1 has a transmittance% at a wavelength of 400 nm in the visible light region lower than that of the squarylium compound 1 although the wavelength% T50 at which the transmittance becomes 50% shows 800 nm or more. From this, the squarylium compound 1 exhibits a smooth absorption waveform that is excellent in transmittance in the visible light region and does not have a shoulder peak, and can be suitably applied to an optical filter of an imaging device such as a surveillance camera for both day and night. It will be a thing.

  The oxocarbon-based compound of the present invention can be used by being included in an optical filter such as an imaging device or a display device (LED or the like) such as a mobile phone camera, a digital camera, an in-vehicle camera, or a surveillance camera. It can use suitably for the optical filter of the image pick-up element.

Claims (5)

An oxocarbon compound represented by the following formula (1) or the following formula (2).

[In Formula (1) and Formula (2), R ^{1 to} R ⁴ each independently represent a structural unit represented by the following Formula (3). ]

[In Formula (3),
Ring A represents a 4-9 membered cycloalkane monoene ,
Ring B represents an optionally substituted aromatic hydrocarbon ring, aromatic heterocycle, or a condensed ring containing these ring structures, and the ring B contains 12 or more π electrons,
X represents a hydrogen atom, an organic group or a polar functional group,
Y represents an organic group or a polar functional group,
* Represents a binding site with the 4-membered ring in formula (1) or the 5-membered ring in formula (2);
n is an integer of 0 to 6 and m or less (where m is a value obtained by subtracting 3 from the number of members of ring A), and when n is 2 or more, a plurality of Ys are the same. Or different. ]   The oxocarbon compound according to claim 1, wherein Y is an alkyl group or a hydroxyl group. The ring B is an aromatic hydrocarbon ring which may have a substituent,
X is a hydrogen atom, an alkyl group, an alkoxycarbonyl group or an aryl group,
The oxocarbon compound according to claim 1 or 2, wherein Y is an alkyl group or a hydroxyl group .   A resin composition comprising the oxocarbon-based compound according to any one of claims 1 to 3 and a resin component.   An optical filter comprising the resin composition according to claim 4.