Near-infrared fluorescent colorant composition

Abstract

The present invention provides a colorant composition containing a near-infrared fluorescent dye that exhibits strong fluorescence emission intensity in the near-infrared light region and enables the preparation of a colored ink composition that is visible under near-infrared light. [Solution] A colorant composition containing a near-infrared fluorescent dye and pigment having a maximum absorption wavelength of 900 nm or less and a maximum fluorescence wavelength of 650 nm or more and 900 nm or less, wherein the value obtained by dividing the average absorbance of the pigment in the range of 730 to 780 nm by the average absorbance in the range of 380 to 730 nm is 0.6 or less.

Description

[Technical Field]

[0001] The present invention relates to a colorant composition that emits near-infrared fluorescence, and an ink composition containing the colorant composition. [Background technology]

[0002] Invisible inks, invisible to the naked eye, are used for various purposes, including food traceability (clearly identifying the origin, raw materials, processing, manufacturing, and distribution of products) and identification and counterfeit prevention of various industrial products. Invisible inks, also known as stealth inks, concealed inks, or invisible inks, can become visible through heating or chemical reactions, but the most common type is the one that becomes visible upon light irradiation, due to its ease of handling and ability to maintain design integrity and confidentiality. Invisible inks, which become visible when irradiated with light, can be broadly classified into two types: ultraviolet-type inks that fluoresce when irradiated with ultraviolet light, and infrared-type inks that reflect or absorb infrared light, or fluoresce when irradiated with infrared light. Ultraviolet-type invisible inks are usually made visible to the naked eye when irradiated with high-frequency ultraviolet light (black light). However, ultraviolet light is harmful, and there are problems with detecting inks printed inside products or components using ultraviolet light. Infrared invisible inks are invisible to the naked eye when irradiated and can only be visualized using specific equipment, thus improving confidentiality. They are also easier to detect than ultraviolet light when printed inside products or components, and are less harmful than ultraviolet light. For example, Patent Document 1 discloses an infrared phosphor, in which an organic substance that absorbs wavelengths in the infrared region is supported on a black pigment that reflects or transmits light in the infrared region, and an ink composition containing such an infrared phosphor. It is stated that this can be used in ordinary black and white barcodes and can be read by barcode scanners, and can also be read as an infrared phosphor regardless of the background color.

[0003] On the other hand, in recent years, near-infrared fluorescent dyes have been used for the purpose of identifying and preventing counterfeiting of various industrial products, and are also used in medical applications such as bioimaging probes and diagnostic reagents. To ensure visibility, it is desirable that the near-infrared fluorescent dye itself strongly absorbs light in the near-infrared region and emits strong fluorescence (high emission quantum yield). Patent document 2 discloses a resin composition containing a specific near-infrared fluorescent dye, which is a BODIPY dye or a DPP-based boron complex having a boron dipyrromethene skeleton, and a resin, with a maximum absorption wavelength of 700 nm or higher, and it is stated that a near-infrared fluorescent resin composition with strong emission intensity and a molded article thereof can be obtained. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 08-183952 [Patent Document 2] International Publication No. 2015 / 056779 [Overview of the project] [Problems that the invention aims to solve]

[0005] The ink composition described in Patent Document 1 is said to allow the infrared phosphor to be read even when printed in layers, but if phosphors with similar excitation fluorescence wavelengths are used, individual identification may be difficult from the standpoint of traceability, etc. Patent Document 2 discloses a near-infrared fluorescent resin composition, and there is a need for an infrared-type invisible ink that is more versatile from the viewpoint of manufacturing cost, environmental considerations, simplification of the manufacturing process, and improved safety. As a result of diligent research, the inventors have found that a composition containing a specific near-infrared fluorescent dye and a colorant as constituent components, wherein the absorption and fluorescence wavelengths of the near-infrared fluorescent dye and the absorbance in a specific wavelength range of the colorant satisfy predetermined conditions, can overcome the drawbacks of ultraviolet-type invisible inks and is useful as a raw material for invisible inks used for traceability and anti-counterfeiting applications. An object of the present invention is to provide a colorant composition containing a near-infrared fluorescent dye that can prepare a colored ink composition having a strong fluorescence emission intensity in the near-infrared light region and being visible with near-infrared light.

Means for Solving the Problem

[0006] The present invention has the following aspects. [1] A colorant composition containing a near-infrared fluorescent dye having a maximum absorption wavelength of 900 nm or less and a maximum fluorescence wavelength of 650 nm or more and 900 nm or less, and a pigment, wherein the value obtained by dividing the average value of the absorbance in the range of 730 to 780 nm of the pigment by the average value of the absorbance in the range of 380 to 730 nm is 0.6 or less. [2] The near-infrared fluorescent dye is represented by the following general formula (I1)

[0007] [Chemical formula]

[0008] [In formula (I1), R a and R b together with the nitrogen atom to which R a is bonded and the carbon atom to which R b is bonded, form a condensed aromatic ring formed by condensation of an aromatic 5-membered ring, an aromatic 6-membered ring, or 2 to 3 5-membered rings or 6-membered rings; R c and R d together with the nitrogen atom to which R c is bonded and the carbon atom to which R d is bonded, form a condensed aromatic ring formed by condensation of an aromatic 5-membered ring, an aromatic 6-membered ring, or 2 to 3 5-membered rings or 6-membered rings; R e and R f represent a halogen atom or an oxygen atom; R g represents a hydrogen atom or an electron-withdrawing group. However, when R e and R f are oxygen atoms, R e , the boron atom bonded to R e , R a , and the nitrogen atom to which R a is bonded may together form a ring, Rf , R f The boron atom that bonds with R c , and R c The nitrogen atoms to which it is bonded may together form a ring. R e If it is an oxygen atom and does not form a ring, then R e R is an oxygen atom having a substituent, f If it is an oxygen atom and does not form a ring, then R f is an oxygen atom having a substituent. ] Compounds represented by ] The following general formula (I2)

[0009] [ka]

[0010] [In formula (I2), R a ~R f The compound shown is as defined above. The following general formula (I3)

[0011] [ka]

[0012] [In formula (I3), R h and R i R h The nitrogen atom and R to which it is bonded i Together with the carbon atom to which it is bonded, it forms an aromatic five-membered ring, an aromatic six-membered ring, or a condensed aromatic ring formed by the condensation of two to three five-membered or six-membered rings; R j and R k R j The nitrogen atom and R to which it is bonded k Together with the carbon atom to which it is bonded, it forms an aromatic five-membered ring, an aromatic six-membered ring, or a condensed aromatic ring formed by the condensation of two to three five-membered or six-membered rings; R l , R m , R n , and R o These are halogen atoms, C, independently of each other. 1-20 Alkyl alkyl group, C 1-20R represents an alkoxy group, an aryl group, or a heteroaryl group; p and R q These are hydrogen atoms, halogen atoms, and C, which are independent of each other. 1-20 Alkyl alkyl group, C 1-20 R represents an alkoxy group, an aryl group, or a heteroaryl group. r and R s These independently represent a hydrogen atom or an electron-withdrawing group. Compounds represented by ], and The following general formula (I4)

[0013] [ka]

[0014] [In formula (I4), R h ~R q [This is as defined above] A colorant composition of [1], which is one or more compounds selected from the group consisting of the compounds shown in [1]. [3] The colorant composition of [1] or [2], wherein the pigment is a bisbenzofuranone pigment. [4] An ink composition containing any of the colorant compositions [1] to [3]. [Effects of the Invention]

[0015] According to the present invention, a colorant composition containing a near-infrared fluorescent dye can be provided, which allows for the preparation of a colored ink composition that exhibits strong fluorescence emission intensity in the near-infrared light region and is visible under near-infrared light. [Modes for carrying out the invention]

[0016] The present invention relates to a colorant composition (hereinafter simply referred to as "the colorant composition of the present invention") that contains a near-infrared fluorescent dye and a pigment having a maximum absorption wavelength of 900 nm or less and a maximum fluorescence wavelength of 650 nm or more and 900 nm or less, wherein the value obtained by dividing the average absorbance of the pigment in the range of 730 to 780 nm by the average absorbance in the range of 380 to 730 nm is 0.6 or less. The colorant composition of the present invention exhibits strong fluorescence emission intensity in the near-infrared light region, enabling the creation of ink compositions visible under near-infrared light. Furthermore, by including the specific pigments described above, ink compositions that do not interfere with excitation fluorescence induced by near-infrared light irradiation can be created. In other words, ink compositions suitable for traceability and anti-counterfeiting applications, where fluorescence intensity reduction is suppressed and fluorescence observation is easy, can be produced from the colorant composition of the present invention.

[0017] The total content of the near-infrared fluorescent dye and the above pigment in the entire colorant composition of the present invention is preferably 50% by mass or more, and more preferably 80% by mass or more. The total content of the near-infrared fluorescent dye and the above pigment in the entire colorant composition of the present invention may be 100% by mass. Furthermore, in the colorant composition of the present invention, the content of the near-infrared fluorescent dye relative to the total amount of the near-infrared fluorescent dye and the above pigment is preferably 0.01% by mass or more and 5% by mass or less, more preferably 0.05% by mass or more and 3% by mass or less, and even more preferably 0.1% by mass or more and 1% by mass or less. When the content of the near-infrared fluorescent dye is within the above range, the dispersibility of the near-infrared fluorescent dye in the colorant composition of the present invention can be well maintained, and excitation fluorescence by irradiation with near-infrared light can be easily emitted, and the fluorescence emission intensity can be easily improved. The near-infrared fluorescent dyes and pigments constituting the colorant composition of the present invention will be described below.

[0018] [Near-infrared fluorescent dyes] The near-infrared fluorescent dye constituting the colorant composition of the present invention has a maximum absorption wavelength of 900 nm or less and a maximum fluorescence wavelength of 650 nm or more and 900 nm or less. The maximum absorption wavelength of the near-infrared fluorescent dye is more preferably 850 nm or less, and even more preferably 800 nm or less. The maximum absorption wavelength of the near-infrared fluorescent dye is more preferably 700 nm or more. When the maximum absorption wavelength of the near-infrared fluorescent dye is within the above range, it is easier to increase the excitation fluorescence intensity when irradiated with light in the near-infrared wavelength range.

[0019] Specifically, the near-infrared fluorescent dye constituting the colorant composition of the present invention includes one or more compounds selected from the group consisting of compounds represented by the following general formulas (I1), (I2), (I3), or (I4). These compounds may hereinafter be referred to as "the near-infrared fluorescent dye according to the present invention."

[0020] [ka]

[0021] [ka]

[0022] In general formula (I1) or general formula (I2), R a and R b R a The nitrogen atom and R to which it is bonded b It forms an aromatic ring consisting of 1 to 3 rings together with the carbon atom to which it is bonded. Similarly, in general formula (I1) or general formula (I2), R c and R d R c The nitrogen atom and R to which it is bonded d It forms an aromatic ring consisting of 1 to 3 rings together with the carbon atom to which it is bonded. a and R b , and R c and R d The aromatic rings formed by each are either 5-membered or 6-membered rings. Compounds represented by general formula (I1) or general formula (I2) are R a and R b , R c and R d Each of these compounds has a ring structure in which the aromatic rings it forms are fused by a ring containing a boron atom bonded to two nitrogen atoms. In other words, the compounds represented by general formula (I1) or general formula (I2) have a robust fused ring structure consisting of a broad conjugated plane.

[0023] In general formula (I3) or general formula (I4), R h and R i R h The nitrogen atom and R to which it is bondedi It forms an aromatic ring consisting of 1 to 3 rings together with the carbon atom to which it is bonded. Similarly, in general formula (I3) or general formula (I4), R j and R k R j The nitrogen atom and R to which it is bonded k It forms an aromatic ring consisting of 1 to 3 rings together with the carbon atom to which it is bonded. h and R i , and R j and R k The aromatic rings formed by each are either 5-membered or 6-membered rings. Compounds represented by general formula (I3) or general formula (I4) are R h and R i A triring is formed by the condensation of an aromatic ring, a ring containing a boron atom bonded to two nitrogen atoms, and a five-membered heteroring containing one nitrogen atom, and R j and R k The compound has a ring structure in which at least six rings are fused together, i.e., a ring structure in which an aromatic ring formed by the compound is fused with a ring containing a boron atom bonded to two nitrogen atoms and a five-membered heteroring containing one nitrogen atom, and these three rings are fused together with the five-membered heterorings. Thus, the compound represented by general formula (I3) or general formula (I4) has a robust fused ring structure consisting of a very broad conjugated plane.

[0024] R a and R b , R c and R d , R h and R i , and R j and R k Examples of aromatic rings formed by these rings include pyrrole rings, imidazole rings, pyrazole rings, oxazole rings, thiazole rings, pyridine rings, pyrimidine rings, pyridazine rings, isoindole rings, indole rings, indazole rings, purine rings, perimidine rings, thienopyrrole rings, phlopyrrole rings, pyrrolothiazole rings, and pyrrolooxazole rings. These aromatic rings may have no substituents or may have one or more substituents. Since the maximum fluorescence wavelength is extended to the near-infrared region, it is particularly preferable that the number of ring fusions of the aromatic ring be 2 or 3 in the case of general formula (I1) or general formula (I3), and more preferably 2 from the standpoint of complexity in synthesis. However, even when the number of ring fusions of the aromatic ring is 1, it is possible to extend the wavelength by devising substituents on the ring or on the boron. Furthermore, in the case of general formula (I2) or general formula (I4), the maximum fluorescence wavelength can be extended to the near-infrared region simply by attaching a substituted aryl group or heteroaryl group.

[0025] Examples of such substituents include halogen atoms such as fluorine, chlorine, bromine, and iodine; Alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl (tert-butyl), pentyl, isoamyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl groups; alkenyl groups such as vinyl, allyl, 1-propenyl, isopropenyl, 2-butenyl, 1,3-butadienyl, 2-pentenyl, and 2-hexenyl groups; alkynyl groups such as ethynyl, 1-propynyl, 2-propynyl, isopropynyl, 1-butynyl, and isobutynyl groups; and other linear, branched, or cyclic alkyl, alkenyl, and alkynyl groups having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms; Alkyl sulfonyl groups, alkylthio groups, alkoxycarbonyl groups, alkylamide carbonyl groups, alkylcarbonylamide groups, acyl groups, monoalkylsilyl groups, dialkylsilyl groups, trialkylsilyl groups, monoalkoxysilyl groups, dialkoxysilyl groups, and trialkoxysilyl groups having the aforementioned alkyl portion; Alkoxy groups such as methoxy group, ethoxy group, propyloxy group, isopropyloxy group, n-butyloxy group, isobutyloxy group, t-butyloxy group, pentyloxy group, isoamyloxy group, hexyloxy group, heptyloxy group, octyloxy group, nonyloxy group, decyloxy group, undecyloxy group, and dodecyloxy group; Monoalkylamino groups such as methylamino group, ethylamino group, propylamino group, isopropylamino group, butylamino group, isobutylamino group, t-butylamino group, pentylamino group, and hexylamino group; dialkylamino groups such as dimethylamino group, diethylamino group, dipropylamino group, diisopropylamino group, dibutylamino group, diisobutylamino group, dipentylamino group, dihexylamino group, ethylmethylamino group, methylpropylamino group, butylmethylamino group, ethylpropylamino group, and butylethylamino group; Aryl groups such as phenyl, naphthyl, indenyl, and biphenyl groups; Five-membered heteroaryl groups such as pyrrolyl, imidazolyl, pyrazolyl, thienyl, furanyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, and thiadiazole groups; six-membered heteroaryl groups such as pyridinyl, pyrazinyl, pyrimidinyl, and pyridadinyl groups; condensed heteroaryl groups such as indolyl, isoindolyl, indazolyl, quinolidinyl, quinolinyl, isoquinolinyl, benzofuranyl, isobenzofuranyl, clomenyl, benzoxazolyl, benzoisoxazolyl, benzothiazolyl, and benzoisothiazolyl groups; Examples include nitro groups, cyano groups, hydroxyl groups, carboxyl groups, aldehyde groups, sulfonic acid groups, halogenosulfonyl groups, thiol groups, isocyanate groups, thioisocyanate groups, amino groups, and silyl groups. These substituents may have further substituents. In particular, cyano groups, hydroxyl groups, carboxyl groups, alkylthio groups, alkyl groups, alkoxy groups, alkoxycarbonyl groups, amide groups, alkylsulfonyl groups, fluorine atoms, chlorine atoms, aryl groups, or heteroaryl groups are preferred.

[0026] The maximum absorption wavelength of fluorescent dyes can be extended to longer wavelengths by narrowing the band gap between the highest occupied orbital (HOMO) and the lowest unoccupied orbital (LUMO) by introducing electron-donating and electron-withdrawing groups at appropriate positions within the molecule. For example, among the compounds represented by general formula (I1), Ra and R b and the aromatic ring formed by R c and R d introduce an electron-donating group into the aromatic ring formed by R g introduce an electron-withdrawing group into R, whereby the maximum absorption wavelength and the maximum fluorescence wavelength of the compound can be made longer. Similarly, among the compounds represented by the general formula (I3), R h and R i introduce an electron-donating group into the aromatic ring formed by R j and R k introduce an electron-donating group into the aromatic ring formed by R p and R q when it is an aromatic ring, introduce an electron-donating group into the aromatic ring, or R r and R s introduce an electron-withdrawing group into R, whereby the maximum absorption wavelength and the maximum fluorescence wavelength of the compound can be made longer. By combining these designs, it can be adjusted to the target wavelength. The compound represented by the general formula (I2) having an azaBODIPY skeleton has a skeleton that has absorption at a relatively long wavelength even when the aromatic ring formed by R a and R b and the aromatic ring formed by R c and R d is unsubstituted. Different from the compound represented by the general formula (I1), in this skeleton, since the cross-linked part of pyrrole is a nitrogen atom, a substituent cannot be introduced onto the nitrogen, but an electron-donating group can be introduced into the pyrrole part (the aromatic ring formed by R a and R b and the aromatic ring formed by R c and R d ), whereby the maximum absorption wavelength and the maximum fluorescence wavelength of the compound can be made longer. Similarly, in the case of the compound represented by the general formula (I4), introduce an electron-donating group into the pyrrole part (the aromatic ring formed by R h and R i and the aromatic ring formed by R j and R k ), or R p and R qIf the compound is an aromatic ring, introducing an electron-donating group to the aromatic ring can extend the maximum absorption wavelength and maximum fluorescence wavelength of the compound to longer wavelengths.

[0027] Therefore, R a and R b , R c and R d , R h and R i , and R j and R k The substituents on the aromatic rings formed by each of these are preferably electron-donating groups. The introduction of electron-donating groups to the aromatic rings causes the fluorescence of the compounds represented by general formulas (I1), (I2), (I3), or (I4) to be directed to longer wavelengths. Examples of electron-donating groups include alkyl groups; alkoxy groups such as methoxy groups; aryl groups such as phenyl groups, p-alkoxyphenyl groups, p-dialkylaminophenyl groups, and dialkoxyphenyl groups; and heteroaryl groups such as 2-thienyl groups and 2-furanyl groups. The number of carbon atoms in the alkyl group and the presence or absence of branching can be appropriately selected in consideration of various physical properties such as solubility and compatibility of the near-infrared fluorescent dye according to the present invention. a and R b , R c and R d , R h and R i , and R j and R k The substituents on the aromatic rings formed by each are C 1-6 Alkyl alkyl group, C 1-6 An alkoxy group, aryl group, or heteroaryl group is preferred, and a methyl group, ethyl group, methoxy group, phenyl group, p-methoxyphenyl group, p-ethoxyphenyl group, p-dimethylaminophenyl group, dimethoxyphenyl group, thienyl group, or furanyl group is more preferred. Because the BODIPY skeleton has high planarity, molecules tend to aggregate through π-π stacking. By introducing an aryl group or heteroaryl group with a bulky substituent into the BODIPY skeleton, molecular aggregation can be suppressed, and the luminescence quantum yield of the colorant composition of the present invention can be increased.

[0028] In general formula (I1) or general formula (I2), R a and R b The aromatic ring formed by and R c and R d The aromatic ring formed by may be different from or the same as the one formed by R. In general formula (I3) or general formula (I4), h and R i The aromatic ring formed by and R j and R k The aromatic ring formed may be different from or the same as the one formed. The near-infrared fluorescent dye according to the present invention is easy to synthesize and tends to have a higher emission quantum yield, a and R b The aromatic ring and R that are formed c and R d The aromatic ring formed by, or R h and R i The aromatic ring and R that are formed j and R k The aromatic rings formed are preferably of the same type.

[0029] In general formula (I1) or general formula (I2), R e and R f These represent, independently of each other, a halogen atom or an oxygen atom. e and R f When the atom is a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom is preferred, a fluorine atom or a chlorine atom is more preferred, and a fluorine atom is particularly preferred. e and R f Compounds in which the fluorine atom is present have a strong bond with the boron atom and exhibit high heat resistance.

[0030] In general formula (I1) or general formula (I2), R e and R f If R is an oxygen atom, e , R e The boron atom that bonds with R a , and R a The nitrogen atoms to which it is bonded may together form a ring, R f , R f The boron atom that bonds with R c , and R cThe nitrogen atoms to which it is bonded may together form a ring. In other words, when a ring structure is formed, R e , R e The boron atom that bonds with R a , and R a The ring formed by the nitrogen atom to which it is bonded is R a and R b It condenses with the aromatic ring formed by R f , R f The boron atom that bonds with R c , and R c The ring formed by the nitrogen atom to which it is bonded is R c and R d It condenses with the aromatic ring that it forms. e Rings and R formed by the above f The rings formed by these are preferably six-membered rings.

[0031] In general formula (I1) or general formula (I2), R e If it is an oxygen atom and does not form a ring, then R e C is an oxygen atom having a substituent (an oxygen atom bonded to a substituent). The substituent may be C 1-20 Examples include alkyl groups, aryl groups, heteroaryl groups, alkylcarbonyl groups, arylcarbonyl groups, or heteroarylcarbonyl groups. Similarly, in general formula (I1) or general formula (I2), R f If it is an oxygen atom and does not form a ring, then R f R is an oxygen atom having a substituent (an oxygen atom bonded to a substituent). The substituent is R. e The substituents are similar to those exemplified in the explanation. e and R f If both are oxygen atoms with substituents, R e The substituents and R f The substituents that it possesses may be of the same type or different types.

[0032] In general formula (I1) or general formula (I2), R e and R f If R is an oxygen atom, e , R f , and R eand R f The boron atoms bonded to it may together form a ring. For example, the ring structure may be R e and R f Structures in which the same aryl ring or heteroaryl ring is linked, R e and R f One example is a structure in which these groups are linked by alkylene groups.

[0033] In general formula (I3) or general formula (I4), R l , R m , R n , and R o These are, independently of each other, halogen atoms, C 1-20 Alkyl alkyl group, C 1-20 This represents an alkoxy group, an aryl group, or a heteroaryl group. In the present invention and specification, "C" refers to a group that is alkoxy, aryl, or heteroaryl. 1-20 "Alkyl alkyl" refers to an alkyl group with 1 to 20 carbon atoms, and "C 1-20 The term "alkoxy group" refers to an alkoxy group having 1 to 20 carbon atoms. R l , R m , R n , or R o The halogen atom represented by is preferably a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, more preferably a fluorine atom or a chlorine atom, and particularly preferably a fluorine atom. l , R m , R n , and R o Compounds in which the fluorine atom is present have a strong bond with the boron atom and exhibit high heat resistance. R l , R m , R n , or R o C represented by 1-20 The alkyl group may be linear, branched, or cyclic, and may be the same type of group as the alkyl group represented by the substituent mentioned above. R l , R m , R n , or R o C represented by 1-20 Examples of alkoxy groups include those similar to the alkoxy groups represented by the substituents mentioned above. R l , R m , R n , or R o The aryl group and heteroaryl group represented by can be the same as the aryl group and heteroaryl group represented by the substituents mentioned above. R l , R m , R n , or R o C represented by 1-20 Alkyl alkyl group, C 1-20 The alkoxy group, aryl group, and heteroaryl group may have one or more hydrogen atoms substituted with substituents such as halogen atoms, alkyl groups, alkoxy groups, nitro groups, cyano groups, hydroxyl groups, amino groups, thiol groups, carboxyl groups, aldehyde groups, sulfonic acid groups, isocyanate groups, thioisocyanate groups, aryl groups, and heteroaryl groups.

[0034] Compounds represented by general formula (I3) or general formula (I4) include R l , R m , R n , and R o Preferably, the element is a halogen atom, an unsubstituted aryl group, or a substituted aryl group, and may be a fluorine atom, a chlorine atom, a bromine atom, an unsubstituted phenyl group, or C 1-20 Alkyl or C 1-20 A phenyl group substituted with an alkoxy group is preferred, and may be a fluorine atom, a chlorine atom, an unsubstituted phenyl group, or C 1-10 Alkyl or C 1-10 Phenyl groups substituted with alkoxy groups are more preferred, and fluorine atoms or unsubstituted phenyl groups are particularly preferred.

[0035] In general formula (I3) or general formula (I4), R p and R q These are, independently of each other, hydrogen atoms, halogen atoms, and C 1-20 Alkyl alkyl group, C 1-20 Represents an alkoxy group, aryl group, or heteroaryl group. p and R q The halogen atom represented by C 1-20 Alkyl alkyl group, C 1-20The alkoxy group, aryl group, and heteroaryl group are R of the general formula (I3) mentioned above. l , R m , R n , or R o Similar bases can be cited.

[0036] Compounds represented by general formula (I3) or general formula (I4) include R p and R q Compounds in which the group is a hydrogen atom or an aryl group are preferred, and unsubstituted phenyl groups or C 1-20 Alkyl or C 1-20 Compounds with phenyl groups substituted with alkoxy groups are preferred, as are unsubstituted phenyl groups or C 1-20 Compounds in which the phenyl group is substituted with an alkoxy group are more preferred, and unsubstituted phenyl groups or C 1-10 Compounds in which a phenyl group is substituted with an alkoxy group are particularly preferred.

[0037] In general formula (I1), R g R represents a hydrogen atom or an electron-withdrawing group. Also, in general formula (I3), R r and R s These groups independently represent a hydrogen atom or an electron-withdrawing group. Examples of such electron-withdrawing groups include methyl halides such as trifluoromethyl; nitro; cyano; aryl; heteroaryl; alkynyl; alkenyl; substituents having a carbonyl group such as carboxyl, acyl, carbonyloxy, amide, and aldehyde; sulfoxide; sulfonyl; alkoxymethyl; and aminomethyl. Additionally, aryl and heteroaryl groups having these electron-withdrawing groups as substituents are also included. Among these, trifluoromethyl, nitro, cyano, phenyl, and sulfonyl groups are preferred because they can function as strong electron-withdrawing groups, thus extending the maximum fluorescence wavelength.

[0038] As near-infrared fluorescent dyes that can be used in the present invention, compounds having a borondipyrromethene skeleton represented by the following general formula (I1-0) or general formula (I2-0) are preferred because the maximum fluorescence wavelength is longer, and in particular compounds in which a pyrrole ring is fused with an aromatic ring or a heteroaromatic ring that satisfy the following (p2), (p3), (q2), or (q3) are preferred because the maximum fluorescence wavelength is even longer.

[0039] [ka]

[0040] In general formula (I1-0) or general formula (I2-0), R 1 , R 2 , and R 3 It satisfies one of the following conditions (p1) to (p3). (p1) Independently of each other, hydrogen atoms, halogen atoms, C 1-20 Alkyl alkyl group, C 1-20 Represents an alkoxy group, an aryl group, or a heteroaryl group. (p2)R 1 and R 2 Both form an aromatic 5-membered ring or an aromatic 6-membered ring, R 3 is a hydrogen atom, halogen atom, C 1-20 Alkyl alkyl group, C 1-20 Represents an alkoxy group, an aryl group, or a heteroaryl group, (p3)R 2 and R 3 Both form an aromatic 5-membered ring or an aromatic 6-membered ring, R 1 is a hydrogen atom, halogen atom, C 1-20 Alkyl alkyl group, C 1-20 This represents an alkoxy group, an aryl group, or a heteroaryl group. R 4 , R 5 , and R 6 It satisfies any of the following conditions (q1) to (q3). (q1) Independently of each other, hydrogen atoms, halogen atoms, C 1-20 Alkyl alkyl group, C 1-20 Represents an alkoxy group, an aryl group, or a heteroaryl group. (q2)R 4 and R 5 Both form an aromatic 5-membered ring or an aromatic 6-membered ring, R 6 is a hydrogen atom, halogen atom, C 1-20 Alkyl alkyl group, C 1-20 Represents an alkoxy group, an aryl group, or a heteroaryl group, (q3)R 5 and R 6 Both form an aromatic 5-membered ring or an aromatic 6-membered ring, R 4 is a hydrogen atom, halogen atom, C 1-20 Alkyl alkyl group, C 1-20 This represents an alkoxy group, an aryl group, or a heteroaryl group.

[0041] The halogen atoms in (p1)~(p3) or (q1)~(q3) above, C 1-20 Alkyl alkyl group, C 1-20 The alkoxy group, aryl group, and heteroaryl group are, respectively, R a and R b Examples of substituents that may be present in the aromatic ring formed by the compound include groups similar to those exemplified above.

[0042] In the above (p2)~(p3) or (q2)~(q3), R 1 and R 2 , R 4 and R 5 , R 2 and R 3 , and R 5 and R 6 The aromatic five-membered ring or aromatic six-membered ring formed by these components together is preferably a structure represented by any of the following general formulas (C-1) to (C-9), and more preferably a structure represented by any of the following general formulas (C-1), (C-2), or (C-9). In the following general formulas (C-1) to (C-9), the parts marked with an asterisk are the parts that bond with the borondipyrromethene skeleton in general formula (I1-0) or general formula (I2-0).

[0043] [ka]

[0044] In the general formulas (C-1) to (C-8), Y 1 ~Y 8 These elements independently represent a sulfur atom, an oxygen atom, a nitrogen atom, or a phosphorus atom. 1 ~Y 8 Preferably, these atoms are sulfur atoms, oxygen atoms, or nitrogen atoms, and more preferably, sulfur atoms or oxygen atoms, independently of each other.

[0045] In the general formulas (C-1) to (C-9), R 11 ~R 22 These are hydrogen atoms, or R, that are independent of each other. a and R b R represents a group similar to the substituents exemplified above that may be present in the aromatic ring formed by the compound. 11 ~R 22 Preferably, each of these groups is independently a hydrogen atom, an unsubstituted aryl group, a substituted aryl group, an unsubstituted heteroaryl group, or a substituted heteroaryl group; more preferably, a hydrogen atom, an (unsubstituted) phenyl group, a p-methoxyphenyl group, a p-ethoxyphenyl group, a p-dimethylaminophenyl group, a dimethoxyphenyl group, a thienyl group, or a furanyl group; and even more preferably, a hydrogen atom, an (unsubstituted) phenyl group, or a p-methoxyphenyl group. It is particularly preferable that the compound is substituted with at least one of the aforementioned unsubstituted aryl groups, substituted aryl groups, unsubstituted heteroaryl groups, or substituted heteroaryl groups, in order to enhance electron-donating properties and to suppress aggregation of the BODIPY skeleton by the bulky substituents.

[0046] As for compounds of general formula (I1-0) or general formula (I2-0), R 1 and R 4 , R 2 and R 5 , and R 3 and R 6 These may be different from each other, but it is preferable that they be of the same type. That is, R 1 , R 2 , and R 3If the above (p1) is satisfied, R 4 , R 5 , and R 6 It is preferable that the above (q1) is satisfied, and R 1 , R 2 , and R 3 If the above (p2) is satisfied, R 4 , R 5 , and R 6 It is preferable that the above (q2) is satisfied, R 1 , R 2 , and R 3 If the above (p3) is satisfied, R 4 , R 5 , and R 6 It is preferable that the above (q3) is satisfied.

[0047] As for compounds of general formula (I1-0) or general formula (I2-0), R 1 and R 2 They form a ring, R 4 and R 5 R forms a ring, or 2 and R 3 They form a ring, R 5 and R 6 It is preferable that the rings form a ring. That is, R 1 , R 2 , and R 3 The above (p2) or (p3) is satisfied, R 4 , R 5 , and R 6 A compound satisfying (q2) or (q3) is preferred. This is because the condensation of an aromatic ring or heteroaromatic ring with the borondipyrrometene skeleton results in a longer wavelength for maximum fluorescence.

[0048] In general formula (I1-0) or general formula (I2-0), R 7 and R 8 R represents a halogen atom or an oxygen atom. 7 and R 8 If it is an oxygen atom, R 7 , R 7 A boron atom bonded to it, a nitrogen atom bonded to the boron atom, R 1 , and R1 The carbon atoms bonded to it may together form a ring, R 8 , R 8 A boron atom bonded to it, a nitrogen atom bonded to the boron atom, R 4 , and R 4 The carbon atoms bonded to it may together form a ring. That is, R 7 and boron atoms and R 1 The ring formed by the etc., and R 8 and boron atoms and R 4 The rings formed by these structures all condense with the borondipyrromethene skeleton. 7 and boron atoms and R 1 The ring formed by the etc., and R 8 and boron atoms and R 4 The rings formed by these are preferably six-membered rings.

[0049] In general formula (I1-0) or general formula (I2-0), R 7 If it is an oxygen atom and does not form a ring, then R 7 C is an oxygen atom having a substituent (an oxygen atom bonded to a substituent). The substituent may be C 1-20 Examples include alkyl groups, aryl groups, or heteroaryl groups. Similarly, in general formula (I1-0) or general formula (I2-0), R 8 If it is an oxygen atom and does not form a ring, then R 8 C is an oxygen atom having a substituent (an oxygen atom bonded to a substituent). The substituent may be C 1-20 Examples include alkyl groups, aryl groups, or heteroaryl groups. 7 and R 8 If both are oxygen atoms with substituents, R 7 The substituents and R 8 The substituents on it may be of the same type or different types.

[0050] In general formula (I1-0), R 9 R represents a hydrogen atom or an electron-withdrawing group. The electron-withdrawing group is R. gSimilar groups to those listed above can be cited. Among these, fluoroalkyl groups, nitro groups, cyano groups, aryl groups, and sulfonyl groups are preferred from the viewpoint of extending the maximum fluorescence wavelength, as they can function as strong electron-withdrawing groups, and trifluoromethyl groups, nitro groups, cyano groups, phenyl groups, and sulfonyl groups are more preferred.

[0051] The near-infrared fluorescent dye according to the present invention is a compound represented by general formula (I1-0) or general formula (I2-0), R 1 and R 2 Both are rings represented by the above general formula (C-1), R 11 and R 12 One of them is a hydrogen atom, and the other has 1 to 3 of its hydrogen atoms as halogen atoms, C 1-20 Alkyl alkyl group, or C 1-20 A ring is formed which is a phenyl group, thienyl group, or furanyl group, which may be substituted with an alkoxy group, R 4 and R 5 Both are R 1 and R 2 It forms a ring of the same kind as the ring formed by R 3 and R 6 is a hydrogen atom, and R 7 and R 8 A compound in which the atom is a halogen atom; R 1 and R 2 Both are rings represented by the above general formula (C-2), R 13 and R 14 One of them is a hydrogen atom, and the other has 1 to 3 of its hydrogen atoms as halogen atoms, C 1-20 Alkyl alkyl group, or C 1-20 A ring is formed which is a phenyl group, thienyl group, or furanyl group, which may be substituted with an alkoxy group, R 4 and R 5 Both are R 1 and R 2 It forms a ring of the same kind as the ring formed by R 3 and R 6 is a hydrogen atom, and R 7 and R 8 A compound in which the atom is a halogen atom; R 2 and R 3 Both are rings represented by the above general formula (C-1), R 11 and R 12 One of them is a hydrogen atom, and the other has 1 to 3 of its hydrogen atoms as halogen atoms, C 1-20 Alkyl alkyl group, or C 1-20 A ring is formed which is a phenyl group, thienyl group, or furanyl group, which may be substituted with an alkoxy group, R 5 and R 6 Both are R 2 and R 3 It forms a ring of the same kind as the ring formed by R 1 and R 4 is a hydrogen atom, and R 7 and R 8 A compound in which the atom is a halogen atom; R 2 and R 3 Both are rings represented by the following general formula (C-2), R 13 and R 14 One of them is a hydrogen atom, and the other has 1 to 3 of its hydrogen atoms as halogen atoms, C 1-20 Alkyl alkyl group, or C 1-20 A ring is formed which is a phenyl group, thienyl group, or furanyl group, which may be substituted with an alkoxy group, R 5 and R 6 Both are R 2 and R 3 It forms a ring of the same kind as the ring formed by R 1 and R 4 is a hydrogen atom, and R 7 and R 8 A compound in which the atom is a halogen atom; R 2 and R 3 Both are rings represented by the following general formula (C-9), R 19 ~R 22 One of the hydrogen atoms is a halogen atom, and C 1-20 Alkyl alkyl group, or C 1-20 A phenyl group, thienyl group, or furanyl group which may be substituted with an alkoxy group, and the remaining three atoms form a ring with hydrogen atoms, R5 and R 6 Both are R 2 and R 3 It forms a ring of the same kind as the ring formed by R 1 and R 4 hydrogen atoms, halogen atoms, C 1-20 Alkyl alkyl group, or C 1-20 A phenyl group, thienyl group, or furanyl group which may be substituted with an alkoxy group, R 7 and R 8 A compound in which the atom is a halogen atom is preferred. If these compounds are represented by the general formula (I1-0), then R 9 Compounds in which the group is a trifluoromethyl group, a cyano group, a nitro group, or a phenyl group are more preferred, and compounds in which the group is a trifluoromethyl group or a phenyl group are particularly preferred.

[0052] Preferred compounds for the near-infrared fluorescent dye according to the present invention include the following general compounds (I1-1), (I1-2), (I1-3), (I2-1), (I2-2), and (I2-3). Among the following general compounds (I1-1), etc., R 1 , R 3 , R 4 , and R 6 ~R 8 The above is synonymous, ED represents an electron-donating group, EW represents an electron-withdrawing group, and Z 1 ~Z 4 Each ring independently represents a five-membered or six-membered aryl group, or a five-membered or six-membered heteroaryl group.

[0053] [ka]

[0054] For the general formula (I1-1), compounds represented by the general formulas (I1-1-1) to (I1-1-6) are preferred; for the general formula (I1-2), compounds represented by the general formulas (I1-2-1) to (I1-2-12) are preferred; for the general formula (I2-1), compounds represented by the general formulas (I2-1-1) to (I2-1-6) are preferred; and for the general formula (I2-2), compounds represented by the general formulas (I2-2-1) to (I2-2-12) are preferred.

[0055] [ka]

[0056] [ka]

[0057] [ka]

[0058] [ka]

[0059] [ka]

[0060] [ka]

[0061] In the general formulas (I1-1-1)~(I1-1-6), (I1-2-1)~(I1-2-4), (I1-2-7)~(I1-2-10), (I2-1-1)~(I2-1-6), (I2-2-1)~(I2-2-4), and (I2-2-7)~(I2-2-10), Y 11 and Y 12 These represent, independently of each other, an oxygen atom or a sulfur atom, and Y 21 and Y22 These represent, independently of each other, a carbon atom or a nitrogen atom. Compounds represented by general formula (I1-1-1), etc., are Y 11 and Y 12 It is preferable that the atoms are of the same type, Y 21 and Y 22 It is preferable that these atoms are of the same type.

[0062] In general formulas (I1-1-1)~(I1-1-6), (I1-2-1)~(I1-2-12), Q 11 R represents a hydrogen atom or an electron-withdrawing group. As an electron-withdrawing group, R g Groups similar to those listed above can be cited. Compounds represented by general formula (I1-1-1), etc., are Q 11 Compounds in which the group is a trifluoromethyl group, a cyano group, a nitro group, or an optionally substituted phenyl group are preferred, and compounds in which the group is a trifluoromethyl group or an optionally substituted phenyl group are more preferred.

[0063] In the general formulas (I1-1-1)~(I1-1-2), (I1-2-1)~(I1-2-2), (I1-2-6), (I2-1-1)~(I2-1-2), and (I2-2-1)~(I2-2-2), (I2-2-6), X is a halogen atom, C, and X are independent of each other. 1-20 This represents an alkoxy group, an aryloxy group, or an acyloxy group.

[0064] X represents C 1-20 The alkyl group portion of the alkoxy group may be linear, branched, or cyclic (aliphatic ring group). Examples of such alkoxy groups include methoxy, ethoxy, propyloxy, isopropyloxy, n-butyloxy, isobutyloxy, t-butyloxy, pentyloxy, isoamyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy, undecyloxy, and dodecyloxy groups. Examples of aryloxy groups represented by X include phenyloxy group, naphthyloxy group, indenyloxy group, and biphenyloxy group. Examples of the acyloxy group represented by X include alkylcarbonyloxy groups such as methylcarbonyloxy group (acetoxy group), ethylcarbonyloxy group, propylcarbonyloxy group, isopropylcarbonyloxy group, n-butylcarbonyloxy group, isobutylcarbonyloxy group, t-butylcarbonyloxy group, pentylcarbonyloxy group, isoamylcarbonyloxy group, hexylcarbonyloxy group, heptylcarbonyloxy group, octylcarbonyloxy group, nonylcarbonyloxy group, decylcarbonyloxy group, undecylcarbonyloxy group, and dodecylcarbonyloxy group; and arylcarbonyloxy groups such as phenylcarbonyloxy group (benzoyloxy group), naphthylcarbonyloxy group, indenylcarbonyloxy group, and biphenylcarbonyloxy group.

[0065] Compounds represented by any of the general formulas (I1-1-1)~(I1-1-2), (I1-2-1)~(I1-2-2), (I1-2-6), (I2-1-1)~(I2-1-2), (I2-2-1)~(I2-2-2), and (I2-2-6) are preferably compounds in which X is a halogen atom, and are particularly preferably compounds in which X is a fluorine atom.

[0066] In the general formulas (I1-1-3)~(I1-1-4), (I1-2-7), (I1-2-9), (I1-2-11), (I2-1-3)~(I2-1-4), (I2-2-7), (I2-2-9), and (I2-2-11), m1 represents either 0 or 1.

[0067] In the general formulas (I1-1-5)~(I1-1-6), (I1-2-3)~(I1-2-6), (I1-2-8), (I1-2-10)~(I1-2-12), (I2-1-5)~(I2-1-6), (I2-2-3)~(I1-2-6), (I2-2-8), and (I2-2-10)~(I2-2-12), P 11 ~P 14 and P 17 These are, independently of each other, halogen atoms, C 1-20 Alkyl alkyl group, C 1-20This represents an alkoxy group, an amino group, a monoalkylamino group, or a dialkylamino group. 11 ~P 14 C in 1-20 Alkyl alkyl group, C 1-20 The alkoxy group, monoalkylamino group, or dialkylamino group are, respectively, the R g The same groups as those listed in (p1)~(p3) and (q1)~(q3) can be cited. 11 ~P 14 and P 17 C 1-20 Alkyl alkyl group, C 1-20 It is preferable that the group is an alkoxy group, an (unsubstituted) phenyl group, a p-methoxyphenyl group, a p-ethoxyphenyl group, a p-dimethylaminophenyl group, a dimethoxyphenyl group, a thienyl group, or a furanyl group.

[0068] General formula (I1-1-5) ~ (I1-1-6), (I1-2-3) ~ (I1-2-6), In (I1-2-8), (I1-2-10)~(I1-2-12), (I2-1-5)~(I2-1-6), (I2-2-3)~(I1-2-6), (I2-2-8), and (I2-2-10)~(I2-2-12), n11~n14 and n17 independently represent integers from 0 to 3. In one numerator, P 11 If there are multiple instances of (i.e., n11 is 2 or 3), multiple P 11 These may all be the same type of group or different types of groups. 12 ~P 14 and P 17 The same applies to this matter.

[0069] In the general formulas (I1-1-1)~(I1-1-6), (I1-2-1)~(I1-2-4), (I1-2-6)~(I1-2-12), (I2-1-1)~(I2-1-6), (I2-2-1)~(I2-2-4), and (I2-2-6)~(I2-2-12), A 11 ~A 14 These are, independently of each other, halogen atoms, C 1-20 Alkyl alkyl group, C 1-20A phenyl group having 1 to 3 substituents selected from the group consisting of alkoxy groups, amino groups, monoalkylamino groups, and dialkylamino groups, or a halogen atom, C 1-20 Alkyl alkyl group, C 1-20 This represents a heteroaryl group which may have 1 to 3 substituents selected from the group consisting of alkoxy groups, amino groups, monoalkylamino groups, and dialkylamino groups. The R in the general formula (I3) above represents the heteroaryl group. l , R m , R n , or R o Similar groups are mentioned, with thienyl or furanyl groups being preferred. C in the substituent that the phenyl group or heteroaryl group may have. 1-20 Alkyl alkyl group, C 1-20 The alkoxy group, monoalkylamino group, or dialkylamino group are, respectively, the R g The same groups as those listed in (p1)~(p3) and (q1)~(q3) can be listed. A 11 ~A 14 These include an unsubstituted phenyl group and one or two carbon atoms. 1-20 A phenyl group having an alkoxy group as a substituent, or a heteroaryl group, is preferred, as is an unsubstituted phenyl group or one carbon atom. 1-20 A phenyl group having an alkoxy group as a substituent is more preferred, as is an unsubstituted phenyl group or a single carbon atom. 1-10 A phenyl group having an alkoxy group as a substituent is more preferable, as is an unsubstituted phenyl group or a single carbon atom. 1-6 A phenyl group having an alkoxy group as a substituent is even more preferred. Also, compounds represented by general formula (I1-1-1), etc., are A 11 ~A 14 It is preferable that all of them are of the same type.

[0070] The near-infrared fluorescent dye according to the present invention is preferably a compound represented by any of the following general formulas (1-1) to (1-37), (2-1) to (2-7), (3-1) to (3-37), (4-1) to (4-7), or (5-1) to (5-2). More preferably a compound represented by any of the following general formulas (1-1) to (1-12), (1-25) to (1-31), (2-1) to (2-7), or (3-25) to (3-31). Even more preferably a compound represented by any of the following general formulas (1-1), (1-3), (1-4), (1-6), (1-25), (1-27), (2-1), (3-1), (3-3), (3-4), (3-6), (3-25), (3-27), or (4-1).

[0071] [ka]

[0072] [ka]

[0073] [ka]

[0074] [ka]

[0075] [ka]

[0076] [ka]

[0077] [ka]

[0078] [ka]

[0079] [ka]

[0080] [ka]

[0081] [ka]

[0082] In general formulas (1-1) to (1-37), (2-1) to (2-7), (3-1) to (3-37), (4-1) to (4-7), (5-1) to (5-2), P 1 ~P 4 and P 18 These are, independently of each other, halogen atoms, C 1-20 Alkyl alkyl group, C 1-20 This represents an alkoxy group, an amino group, a monoalkylamino group, or a dialkylamino group. 1 ~P 4 C in 1-20 Alkyl alkyl group, C 1-20 The alkoxy group, monoalkylamino group, or dialkylamino group are, respectively, the R g The same groups as those listed in (p1)~(p3) and (q1)~(q3) can be cited. 1 ~P 4 and P 18 C 1-20 Alkyl alkyl group, C 1-20 It is preferable that the group is an alkoxy group, an (unsubstituted) phenyl group, a p-methoxyphenyl group, a p-ethoxyphenyl group, a p-dimethylaminophenyl group, a dimethoxyphenyl group, a thienyl group, or a furanyl group.

[0083] In the general formulas (1-1)~(1-37), (2-1)~(2-7), (3-1)~(3-37), (4-1)~(4-7), and (5-1)~(5-2), n1~n4 and n18 represent integers from 0 to 3, independently of each other. In one numerator, P 1 If there are multiple instances of (i.e., when n1 is 2 or 3), multiple P 1 These may all be the same type of group or different types of groups. 2 ~P 4 and P 18 The same applies to this matter.

[0084] In general formulas (1-1) to (1-37), (2-1) to (2-7), and (5-1), Q represents a trifluoromethyl group, a cyano group, a nitro group, or an optionally substituted phenyl group, preferably a trifluoromethyl group or an optionally substituted phenyl group, and more preferably a trifluoromethyl group or an unsubstituted phenyl group. Optional substituents on the phenyl group include halogen atoms and C 1-20 Alkyl alkyl group, C 1-20 Examples include alkoxy groups, amino groups, monoalkylamino groups, and dialkylamino groups.

[0085] In general formulas (1-1) to (1-31) and (3-1) to (3-31), X is the same as in general formula (1-1-1), etc. In compounds represented by general formula (1-1), etc., X is preferably a halogen atom, and particularly preferably a fluorine atom.

[0086] In general formulas (1-32) to (1-34) and (3-32) to (3-34), m2 is either 0 or 1. For compounds represented by general formula (1-32), etc., it is preferable that m2 is 1.

[0087] Compounds represented by general formulas (1-1) to (1-37), (2-1) to (2-7), and (5-1) include P 1 ~P 4 and P 18 They are independent of each other, C 1-20 Alkyl alkyl group, C 1-20Compounds are preferred in which the group is an alkoxy group, an (unsubstituted) phenyl group, a p-methoxyphenyl group, a p-ethoxyphenyl group, a p-dimethylaminophenyl group, a dimethoxyphenyl group, a thienyl group, or a furanyl group, n1 to n4 and n18 are independently 0 to 2, and Q is a trifluoromethyl group or a phenyl group. Similarly, compounds represented by the general formulas (3-1) to (3-37), (4-1) to (4-7), and (5-2) include P 1 ~P 4 and P 18 They are independent of each other, C 1-20 Alkyl alkyl group, C 1-20 Compounds are preferred that are alkoxy groups, (unsubstituted) phenyl groups, p-methoxyphenyl groups, p-ethoxyphenyl groups, p-dimethylaminophenyl groups, dimethoxyphenyl groups, thienyl groups, or furanyl groups, and n1 to n4 and n18 are independently 0 to 2.

[0088] As the near-infrared fluorescent dye according to the present invention, compounds represented by any of the following general formulas (I3-1) to (I3-6), or compounds represented by any of the general formulas (I4-1) to (I4-6), are also preferred because their maximum fluorescence wavelength is longer.

[0089] [ka]

[0090] [ka]

[0091] In general formulas (I3-1) to (I3-6) and general formulas (I4-1) to (I4-6), R 23 , R 24 , R 25 , and R 26 These are, independently of each other, halogen atoms, C 1-20 Alkyl alkyl group, C 1-20 Represents an alkoxy group, aryl group, or heteroaryl group. 23 , R 24 , R 25 , or R26 The halogen atom represented by C 1-20 Alkyl alkyl group, C 1-20 The alkoxy group, aryl group, and heteroaryl group are R of the general formula (I3) mentioned above. l , R m , R n , or R o Similar groups can be cited. Compounds represented by any of the general formulas (I3-1) to (I3-6) or any of the general formulas (I4-1) to (I4-6) are considered to have high thermal stability, and R 23 , R 24 , R 25 , and R 26 Compounds in which the atom is a halogen atom, an unsubstituted aryl group, or a substituted aryl group are preferred, specifically a fluorine atom, a chlorine atom, a bromine atom, an unsubstituted phenyl group, or C 1-20 Alkyl or C 1-20 Compounds that are phenyl groups substituted with alkoxy groups are preferred, and may contain a fluorine atom, a chlorine atom, an unsubstituted phenyl group, or C 1-10 Alkyl or C 1-10 Compounds in which the phenyl group is substituted with an alkoxy group are more preferred, as they yield compounds that combine high luminescence efficiency and thermal stability. Therefore, compounds in which the phenyl group is fluorine or unsubstituted are particularly preferred.

[0092] In general formulas (I3-1) to (I3-6) and general formulas (I4-1) to (I4-6), R 27 and R 28 These are, independently of each other, hydrogen atoms, halogen atoms, and C 1-20 Alkyl alkyl group, C 1-20 Represents an alkoxy group, aryl group, or heteroaryl group. 27 or R 28 The halogen atom represented by C 1-20 Alkyl alkyl group, C 1-20 The alkoxy group, aryl group, and heteroaryl group are R of the general formula (I3) mentioned above. p or R qSimilar groups can be cited. Compounds represented by any of the general formulas (I3-1) to (I3-6) or any of the general formulas (I4-1) to (I4-6) include R 27 and R 28 Compounds in which the group is a hydrogen atom or an aryl group are preferred, as compounds with high luminescence efficiency can be obtained. 1-20 Alkyl or C 1-20 Compounds consisting of phenyl groups substituted with alkoxy groups are preferred, and also include hydrogen atoms, unsubstituted phenyl groups, or linear or branched C atoms. 1-20 Compounds with phenyl groups substituted with alkoxy groups are more preferable, as they yield compounds with high luminescence efficiency. Therefore, unsubstituted phenyl groups or linear or branched C groups are preferable. 1-10 Compounds in which a phenyl group is substituted with an alkoxy group are particularly preferred.

[0093] In general formulas (I3-1) to (I3-6), R 29 and R 30 These independently represent a hydrogen atom or an electron-withdrawing group. 29 or R 30 The electron-withdrawing group represented by is R in the general formula (I3) above. r or R s Similar groups can be cited. Compounds represented by any of the general formulas (I3-1) to (I3-6) can be obtained as compounds with longer fluorescence wavelengths and high luminescence efficiency, R 29 and R 30 However, compounds that are fluoroalkyl groups, nitro groups, cyano groups, or aryl groups that can function as strong electron-withdrawing groups are preferred, and compounds that are trifluoromethyl groups, nitro groups, cyano groups, or phenyl groups which may have substituents are more preferred, as compounds with high luminescence efficiency can be obtained, and therefore compounds with trifluoromethyl groups or cyano groups are more preferred.

[0094] In general formula (I3-1) and general formula (I4-1), Y 9 and Y 10These represent a sulfur atom, an oxygen atom, a nitrogen atom, or a phosphorus atom independently of each other. Compounds represented by general formula (I3-1) or general formula (I4-1) are obtained because they have high luminescence efficiency. 9 and Y 10 However, compounds in which each atom is independently a sulfur atom, an oxygen atom, or a nitrogen atom are preferred, and compounds in which each atom is independently a sulfur atom or an oxygen atom are more preferred, as compounds that combine high luminescence efficiency and thermal stability can be obtained. Therefore, compounds in which both atoms are sulfur atoms or both atoms are oxygen atoms are even more preferred.

[0095] In general formulas (I3-3) to (I3-6) and general formulas (I4-3) to (I4-6), X 1 and X 2 These represent a nitrogen atom or a phosphorus atom independently of each other. Compounds represented by general formulas (I3-3) to (I3-6) or general formulas (I4-3) to (I4-6) include X 1 and X 2 However, compounds that are both nitrogen atoms or phosphorus atoms are preferred because they yield compounds with high luminescence efficiency, and compounds that are both nitrogen atoms are more preferred because they yield compounds that combine high luminescence efficiency and thermal stability.

[0096] In general formula (I3-1) and general formula (I4-1), R 31 and R 32 The following conditions (p4) or (p5) are met: (p4) Independently of each other, hydrogen atoms, halogen atoms, C 1-20 Alkyl alkyl group, C 1-20 This represents an alkoxy group, an aryl group, or a heteroaryl group. (p5)R 31 and R 32 Both form an aromatic five-membered ring or an aromatic six-membered ring, which may have substituents. R 33 and R 34 The following conditions (q4) or (q5) are met. (q4) Independently of each other, hydrogen atoms, halogen atoms, C 1-20 Alkyl alkyl group, C 1-20Represents an alkoxy group, an aryl group, or a heteroaryl group, (q5)R 33 and R 34 Both form an aromatic five-membered ring or an aromatic six-membered ring, which may have substituents.

[0097] In general formulas (I3-2) to (I3-6) and general formulas (I4-2) to (I4-6), R 35 , R 36 , R 37 , and R 38 It satisfies one of the following conditions (p6) to (p9). (p6) Independently of each other, hydrogen atoms, halogen atoms, C 1-20 Alkyl alkyl group, C 1-20 This represents an alkoxy group, an aryl group, or a heteroaryl group. (p7)R 35 and R 36 Both form an aromatic five-membered ring or an aromatic six-membered ring which may have substituents, R 37 and R 38 These are independent of each other: hydrogen atoms, halogen atoms, and C 1-20 Alkyl alkyl group, C 1-20 This represents an alkoxy group, an aryl group, or a heteroaryl group. (p8)R 36 and R 37 Both form an aromatic five-membered ring or an aromatic six-membered ring which may have substituents, R 35 and R 38 These are independent of each other: hydrogen atoms, halogen atoms, and C 1-20 Alkyl alkyl group, C 1-20 This represents an alkoxy group, an aryl group, or a heteroaryl group. (p9)R 37 and R 38 Both form an aromatic five-membered ring or an aromatic six-membered ring which may have substituents, R 35 and R 36 These are independent of each other: hydrogen atoms, halogen atoms, and C 1-20 Alkyl alkyl group, C 1-20 This represents an alkoxy group, an aryl group, or a heteroaryl group. R 39 , R 40 , R 41 , and R 42 It satisfies any of the following conditions (q6) to (q9). (q6) Independently of each other, hydrogen atoms, halogen atoms, C 1-20 Alkyl alkyl group, C 1-20 This represents an alkoxy group, an aryl group, or a heteroaryl group. (q7)R 39 and R 40 Both form an aromatic five-membered ring or an aromatic six-membered ring which may have substituents, R 41 and R 42 These are independent of each other: hydrogen atoms, halogen atoms, and C 1-20 Alkyl alkyl group, C 1-20 This represents an alkoxy group, an aryl group, or a heteroaryl group. (q8)R 40 and R 41 Both form an aromatic five-membered ring or an aromatic six-membered ring which may have substituents, R 39 and R 42 These are independent of each other: hydrogen atoms, halogen atoms, and C 1-20 Alkyl alkyl group, C 1-20 This represents an alkoxy group, an aryl group, or a heteroaryl group. (q9)R 41 and R 42 Both form an aromatic five-membered ring or an aromatic six-membered ring which may have substituents, R 39 and R 40 These are independent of each other: hydrogen atoms, halogen atoms, and C 1-20 Alkyl alkyl group, C 1-20 This represents an alkoxy group, an aryl group, or a heteroaryl group.

[0098] The halogen atoms in (p4), (p6)~(p9) and (q4), (q6)~(q9), C 1-20 Alkyl alkyl group, C 1-20 The alkoxy group, aryl group, and heteroaryl group are, respectively, R a and R bThe substituents that may be present in the aromatic ring formed are similar to those exemplified above.

[0099] In the above (p5), (p7)~(p9), (q5), (q7)~(q9), R 31 and R 32 , R 33 and R 34 , R 35 and R 36 , R 36 and R 37 , R 37 and R 38 , R 39 and R 40 , R 40 and R 41 , and R 41 and R 42 However, the aromatic five-membered ring or aromatic six-membered ring formed together is preferably a structure represented by any of the general formulas (C-1) to (C-9), and the structure represented by the general formula (C-9) is more preferred because it yields a compound with high thermal stability.

[0100] The compound represented by (I3-1) above is R 23 , R 24 , R 25 , and R 26 Both are halogen atoms, unsubstituted phenyl groups, or C 1-10 Alkyl or C 1-10 A phenyl group substituted with an alkoxy group; R 27 and R 28 Both are hydrogen atoms, unsubstituted phenyl groups, or C 1-20 Alkyl or C 1-20 A phenyl group substituted with an alkoxy group; R 29 and R 30 Both are trifluoromethyl, nitro, cyano, or phenyl groups; Y 9 and Y 10 Both are sulfur atoms or oxygen atoms; R 31 and R 32 These are hydrogen atoms or C, independently of each other. 1-20 It is an alkyl group, or R 31 and R 32They both form a phenyl group which may have substituents; R 33 and R 34 These are hydrogen atoms or C, independently of each other. 1-20 It is an alkyl group, or R 33 and R 34 Compounds that form a phenyl group which may both have substituents are preferred because they have high luminescence efficiency.

[0101] The compound represented by (I3-2) above is R 23 , R 24 , R 25 , and R 26 Both are halogen atoms, unsubstituted phenyl groups, or C 1-10 Alkyl or C 1-10 A phenyl group substituted with an alkoxy group; R 27 and R 28 Both are hydrogen atoms, unsubstituted phenyl groups, or C 1-20 Alkyl or C 1-20 A phenyl group substituted with an alkoxy group; R 29 and R 30 Both are trifluoromethyl groups, nitro groups, cyano groups, or phenyl groups; R 35 , R 36 , R 37 , and R 38 These are hydrogen atoms or C, independently of each other. 1-20 Is it an alkyl group, or R 35 and R 36 Both may form a phenyl group having substituents R 37 and R 38 These are hydrogen atoms or C, independently of each other. 1-20 Is it an alkyl group, or R 36 and R 37 Both may form a phenyl group having substituents R 35 and R 38 These are hydrogen atoms or C, independently of each other. 1-20 It is an alkyl group, or R 37 and R 38 Both may form a phenyl group having substituents R 35 and R 36 These are hydrogen atoms or C, independently of each other.1-20 It is an alkyl group; R 39 , R 40 , R 41 , and R 42 These are hydrogen atoms or C, independently of each other. 1-20 R is an alkyl group. 39 and R 40 They form a phenyl group which may both have substituents, R 41 and R 42 These are hydrogen atoms or C, independently of each other. 1-20 R is an alkyl group. 40 and R 41 They form a phenyl group which may both have substituents, R 39 and R 42 These are hydrogen atoms or C, independently of each other. 1-20 It is an alkyl group, or R 41 and R 42 Both may form a phenyl group having substituents R 39 and R 40 These are hydrogen atoms or C, independently of each other. 1-20 Compounds that are alkyl groups are preferred because they have high luminescence efficiency.

[0102] The compound represented by (I3-3) above is R 23 , R 24 , R 25 , and R 26 Both are halogen atoms, unsubstituted phenyl groups, or C 1-10 Alkyl or C 1-10 A phenyl group substituted with an alkoxy group; R 27 and R 28 Both are hydrogen atoms, unsubstituted phenyl groups, or C 1-20 Alkyl or C 1-20 A phenyl group substituted with an alkoxy group; R 29 and R 30 Both are trifluoromethyl, nitro, cyano, or phenyl groups; X 1 and X 2 Both are nitrogen atoms; R 36 , R 37 , and R 38 These are hydrogen atoms or C, independently of each other.1-20 Is it an alkyl group, or R 36 and R 37 Both may form a phenyl group having substituents R 38 is a hydrogen atom or C 1-20 It is an alkyl group, or R 37 and R 38 Both may form a phenyl group having substituents R 36 is a hydrogen atom or C 1-20 It is an alkyl group; R 40 , R 41 , and R 42 These are hydrogen atoms or C, independently of each other. 1-20 Is it an alkyl group, or R 40 and R 41 Both may form a phenyl group having substituents R 42 is a hydrogen atom or C 1-20 It is an alkyl group, or R 41 and R 42 Both may form a phenyl group having substituents R 40 is a hydrogen atom or C 1-20 Compounds that are alkyl groups are preferred because they have high luminescence efficiency.

[0103] The compound represented by (I3-4) above is R 23 , R 24 , R 25 , and R 26 Both are halogen atoms, unsubstituted phenyl groups, or C 1-10 Alkyl or C 1-10 A phenyl group substituted with an alkoxy group; R 27 and R 28 Both are hydrogen atoms, unsubstituted phenyl groups, or C 1-20 Alkyl or C 1-20 A phenyl group substituted with an alkoxy group; R 29 and R 30 Both are trifluoromethyl, nitro, cyano, or phenyl groups; X 1 and X 2 Both are nitrogen atoms; R 35 , R 36 , and R 37These are hydrogen atoms or C, independently of each other. 1-20 Is it an alkyl group, or R 35 and R 36 Both may form a phenyl group having substituents R 37 is a hydrogen atom or C 1-20 It is an alkyl group, or R 36 and R 37 Both may form a phenyl group having substituents R 35 is a hydrogen atom or C 1-20 It is an alkyl group; R 39 , R 40 , and R 41 These are hydrogen atoms or C, independently of each other. 1-20 Is it an alkyl group, or R 39 and R 40 Both may form a phenyl group having substituents R 41 is a hydrogen atom or C 1-20 It is an alkyl group, or R 40 and R 41 Both may form a phenyl group having substituents R 39 is a hydrogen atom or C 1-20 Compounds that are alkyl groups are preferred because they have high luminescence efficiency.

[0104] The compounds represented by (I3-5) above include R 23 , R 24 , R 25 , and R 26 Both are halogen atoms, unsubstituted phenyl groups, or C 1-10 Alkyl or C 1-10 A phenyl group substituted with an alkoxy group; R 27 and R 28 Both are hydrogen atoms, unsubstituted phenyl groups, or C 1-20 Alkyl or C 1-20 A phenyl group substituted with an alkoxy group; R 29 and R 30 Both are trifluoromethyl, nitro, cyano, or phenyl groups; X 1 and X 2 Both are nitrogen atoms; R 35 , R 36 , and R38 These are hydrogen atoms or C, independently of each other. 1-20 It is an alkyl group, or R 35 and R 36 Both may form a phenyl group having substituents R 38 is a hydrogen atom or C 1-20 It is an alkyl group; R 39 , R 40 , and R 42 These are hydrogen atoms or C, independently of each other. 1-20 It is an alkyl group, or R 39 and R 40 Both may form a phenyl group having substituents R 42 is a hydrogen atom or C 1-20 Compounds that are alkyl groups are preferred because they have high luminescence efficiency.

[0105] The compound represented by (I3-6) above is R 23 , R 24 , R 25 , and R 26 Both are halogen atoms, unsubstituted phenyl groups, or C 1-10 Alkyl or C 1-10 A phenyl group substituted with an alkoxy group; R 27 and R 28 Both are hydrogen atoms, unsubstituted phenyl groups, or C 1-20 Alkyl or C 1-20 A phenyl group substituted with an alkoxy group; R 29 and R 30 Both are trifluoromethyl, nitro, cyano, or phenyl groups; X 1 and X 2 Both are nitrogen atoms; R 35 , R 37 , and R 38 These are hydrogen atoms or C, independently of each other. 1-20 It is an alkyl group, or R 37 and R 38 Both may form a phenyl group having substituents R 35 is a hydrogen atom or C 1-20 It is an alkyl group; R 39 , R 41 , and R42 are each independently a hydrogen atom or a C 1-20 alkyl group, or R 41 and R 42 together form a phenyl group which may have substituents, and R 39 is a hydrogen atom or a C 1-20 alkyl group; the compound is preferable because of its high luminous efficiency.

[0106] Examples of the compound represented by the formula (I4-1) include those in which R 23 , R 24 , R 25 , and R 26 are each a halogen atom, an unsubstituted phenyl group, or a phenyl group substituted with a C 1-10 alkyl group or a C 1-10 alkoxy group; R 27 and R 28 are each a hydrogen atom, an unsubstituted phenyl group, or a phenyl group substituted with a C 1-20 alkyl group or a C 1-20 alkoxy group; Y 9 and Y 10 are each a sulfur atom or an oxygen atom; R 31 and R 32 are each independently a hydrogen atom or a C 1-20 alkyl group, or R 31 and R 32 together form a phenyl group which may have substituents; R 33 and R 34 are each independently a hydrogen atom or a C 1-20 alkyl group, or R 33 and R 34 together form a phenyl group which may have substituents; the compound is preferable because of its high luminous efficiency.

[0107] Examples of the compound represented by the formula (I4-2) include those in which R 23 , R 24 , R 25 , and R 26 are each a halogen atom, an unsubstituted phenyl group, or a C 1-10 alkyl group or a C 1-10a phenyl group substituted with an alkoxy group; R 27 and R 28 are both a hydrogen atom, an unsubstituted phenyl group, or a C 1-20 alkyl group or a phenyl group substituted with a C 1-20 alkoxy group; R 35 , R 36 , R 37 , and R 38 are each independently a hydrogen atom or a C 1-20 alkyl group, or R 35 and R 36 together form a phenyl group which may have substituents, and R 37 and R 38 are each independently a hydrogen atom or a C 1-20 alkyl group, or R 36 and R 37 together form a phenyl group which may have substituents, and R 35 and R 38 are each independently a hydrogen atom or a C 1-20 alkyl group, or R 37 and R 38 together form a phenyl group which may have substituents, and R 35 and R 36 are each independently a hydrogen atom or a C 1-20 alkyl group; R 39 , R 40 , R 41 , and R 42 are each independently a hydrogen atom or a C 1-20 ​​​​​​​​​​​​​​​​​​​​​​​​Both may form a phenyl group having substituents R 39 and R 42 These are hydrogen atoms or C, independently of each other. 1-20 Compounds that are alkyl groups are preferred because they have high luminescence efficiency.

[0108] The compound represented by (I4-3) above is R 23 , R 24 , R 25 , and R 26 Both are halogen atoms, unsubstituted phenyl groups, or C 1-10 Alkyl or C 1-10 A phenyl group substituted with an alkoxy group; R 27 and R 28 Both are hydrogen atoms, unsubstituted phenyl groups, or C 1-20 Alkyl or C 1-20 A phenyl group substituted with an alkoxy group; X 1 and X 2 Both are nitrogen atoms; R 36 , R 37 , and R 38 These are hydrogen atoms or C, independently of each other. 1-20 Is it an alkyl group, or R 36 and R 37 Both may form a phenyl group having substituents R 38 is a hydrogen atom or C 1-20 It is an alkyl group, or R 37 and R 38 Both may form a phenyl group having substituents R 36 is a hydrogen atom or C 1-20 It is an alkyl group; R 40 , R 41 , and R 42 These are hydrogen atoms or C, independently of each other. 1-20 Is it an alkyl group, or R 40 and R 41 Both may form a phenyl group having substituents R 42 is a hydrogen atom or C 1-20 It is an alkyl group, or R 41 and R 42 Both may form a phenyl group having substituents R40 is a hydrogen atom or C 1-20 Compounds that are alkyl groups are preferred because they have high luminescence efficiency.

[0109] The compound represented by (I4-4) above is R 23 , R 24 , R 25 , and R 26 Both are halogen atoms, unsubstituted phenyl groups, or C 1-10 Alkyl or C 1-10 A phenyl group substituted with an alkoxy group; R 27 and R 28 Both are hydrogen atoms, unsubstituted phenyl groups, or C 1-20 Alkyl or C 1-20 A phenyl group substituted with an alkoxy group; X 1 and X 2 Both are nitrogen atoms; R 35 , R 36 , and R 37 These are hydrogen atoms or C, independently of each other. 1-20 Is it an alkyl group, or R 35 and R 36 Both may form a phenyl group having substituents R 37 is a hydrogen atom or C 1-20 It is an alkyl group, or R 36 and R 37 Both may form a phenyl group having substituents R 35 is a hydrogen atom or C 1-20 It is an alkyl group; R 39 , R 40 , and R 41 These are hydrogen atoms or C, independently of each other. 1-20 Is it an alkyl group, or R 39 and R 40 Both may form a phenyl group having substituents R 41 is a hydrogen atom or C 1-20 It is an alkyl group, or R 40 and R 41 Both may form a phenyl group having substituents R 39 is a hydrogen atom or C 1-20Compounds that are alkyl groups are more preferred because they have higher luminescence efficiency.

[0110] The compound represented by (I4-5) above is R 23 , R 24 , R 25 , and R 26 Both are halogen atoms, unsubstituted phenyl groups, or C 1-10 Alkyl or C 1-10 A phenyl group substituted with an alkoxy group; R 27 and R 28 Both are hydrogen atoms, unsubstituted phenyl groups, or C 1-20 Alkyl or C 1-20 A phenyl group substituted with an alkoxy group; X 1 and X 2 Both are nitrogen atoms; R 35 , R 36 , and R 38 These are hydrogen atoms or C, independently of each other. 1-20 It is an alkyl group, or R 35 and R 36 Both may form a phenyl group having substituents R 38 is a hydrogen atom or C 1-20 It is an alkyl group; R 39 , R 40 , and R 42 These are hydrogen atoms or C, independently of each other. 1-20 It is an alkyl group, or R 39 and R 40 Both may form a phenyl group having substituents R 42 is a hydrogen atom or C 1-20 Compounds that are alkyl groups are preferred because they have high luminescence efficiency.

[0111] The compound represented by (I4-6) above is R 23 , R 24 , R 25 , and R 26 Both are halogen atoms, unsubstituted phenyl groups, or C 1-10 Alkyl or C 1-10 A phenyl group substituted with an alkoxy group; R 27 and R28 Both are hydrogen atoms, unsubstituted phenyl groups, or C 1-20 Alkyl or C 1-20 A phenyl group substituted with an alkoxy group; X 1 and X 2 Both are nitrogen atoms; R 35 , R 37 , and R 38 These are hydrogen atoms or C, independently of each other. 1-20 It is an alkyl group, or R 37 and R 38 Both may form a phenyl group having substituents R 35 is a hydrogen atom or C 1-20 It is an alkyl group; R 39 , R 41 , and R 42 These are hydrogen atoms or C, independently of each other. 1-20 It is an alkyl group, or R 41 and R 42 Both may form a phenyl group having substituents R 39 is a hydrogen atom or C 1-20 Compounds that are alkyl groups are preferred because they have high luminescence efficiency.

[0112] The compound represented by any of (I3-1) to (I3-6) above is preferably a compound represented by any of the following general formulas (I3-7) to (I3-9), and the compound represented by any of (I4-1) to (I4-6) above is preferably a compound represented by any of the following general formulas (I4-7) to (I4-9).

[0113] [ka]

[0114] In general formulas (I3-7) and (I4-7), Y 23 and Y 24 These represent, independently of each other, a carbon atom or a nitrogen atom. In general formulas (I3-7), etc., Y 23 and Y 24 It is preferable that these atoms are of the same type. In general formulas (I3-8) and (I4-8), Y 13 and Y 14 These represent, independently of each other, an oxygen atom or a sulfur atom. In general formulas (I3-8), etc., Y 13 and Y 14 It is preferable that these atoms are of the same type. In general formulas (I3-9) and (I4-9), Y 25 and Y 26 These represent, independently of each other, a carbon atom or a nitrogen atom. In general formulas (I3-9), etc., Y 25 and Y 26 It is preferable that these atoms are of the same type. In general formulas (I3-7) to (I3-9), R 47 and R 48 These groups independently represent a hydrogen atom or an electron-withdrawing group, and since they increase fluorescence intensity, trifluoromethyl, cyano, nitro, sulfonyl, or phenyl groups are preferred, with trifluoromethyl or cyano groups being particularly preferred. In general formulas (I3-7), etc., R 47 and R 48 It is preferable that these are the same type of group.

[0115] In general formulas (I3-7) to (I3-9) and (I4-7) to (I4-9), R 43 , R 44 , R 45 , and R 46 R represents a halogen atom or an aryl group which may have a substituent. a and R b The substituents that may be present in the aromatic ring formed are similar to those exemplified above. Furthermore, examples of substituents that the aryl group may have include C 1-6 Alkyl alkyl group, C 1-6 Examples include alkoxy groups, aryl groups, or heteroaryl groups. In general formulas (I3-7) to (I3-9) and (I4-7) to (I4-9), R 43 ~R 46 These may each be a different group, but it is preferable that they are all of the same type. Compounds represented by any of the general formulas (I3-7)~(I3-9) and (I4-7)~(I4-9) include R43 ~R 46 However, compounds in which all are halogen atoms of the same type, or phenyl groups which may all have substituents of the same type, are preferred, compounds in which all are fluorine atoms or unsubstituted phenyl groups are more preferred, and compounds in which all are fluorine atoms are particularly preferred.

[0116] In general formulas (I3-7) to (I3-9) and (I4-7) to (I4-9), P 15 ~P 16 These are, independently of each other, halogen atoms, C 1-20 Alkyl alkyl group, C 1-20 This represents an alkoxy group, an amino group, a monoalkylamino group, or a dialkylamino group. 15 ~P 16 C in 1-20 Alkyl alkyl group, C 1-20 The alkoxy group, monoalkylamino group, or dialkylamino group are, respectively, the R g The same groups listed in (p1)~(p3) and (q1)~(q3) can be listed. 15 ~P 16 C 1-20 Alkyl alkyl group, C 1-20 A preferred group is an alkoxy group, an (unsubstituted) phenyl group, a p-methoxyphenyl group, a p-ethoxyphenyl group, a p-dimethylaminophenyl group, a dimethoxyphenyl group, a thienyl group, or a furanyl group.

[0117] In the general formulas (I3-7)~(I3-9) and (I4-7)~(I4-9), n15~n16 represent integers from 0 to 3, independently of each other. In one numerator, P 15 If there are multiple instances of (i.e., n15 is 2 or 3), multiple P 15 The groups may be of the same type or different types. 16 The same applies to this matter.

[0118] In general formulas (I3-7) to (I3-9) and (I4-7) to (I4-9), A 15 ~A 16 These are, independently of each other, hydrogen atoms, halogen atoms, and C 1-20 Alkyl alkyl group, C1-20 This represents a phenyl group which may have 1 to 3 substituents selected from the group consisting of alkoxy groups, amino groups, monoalkylamino groups, and dialkylamino groups. 1-20 Alkyl alkyl group, C 1-20 The alkoxy group, monoalkylamino group, or dialkylamino group are, respectively, the R g The same groups listed in (p1)~(p3) and (q1)~(q3) can be listed. 15 ~A 16 Examples include an unsubstituted phenyl group and one or two C13s. 1-20 A phenyl group having an alkoxy group as a substituent is preferred, as is an unsubstituted phenyl group or a single carbon atom. 1-20 A phenyl group having an alkoxy group as a substituent is more preferred, as is an unsubstituted phenyl group or a single carbon atom. 1-10 A phenyl group having an alkoxy group as a substituent is even more preferred. Also, in compounds represented by general formula (I3-7), A 15 ~A 16 Preferably, all of these are of the same type.

[0119] Compounds represented by any of the above formulas (I3-1) to (I3-6) and (I4-1) to (I4-6) include compounds represented by any of the following general formulas (6-1) to (6-12) and (7-1) to (7-12), with compounds represented by general formulas (6-4), (6-5), (6-7), (6-8), (7-4), (7-5), (7-7), and (7-8) being preferred, and compounds represented by general formulas (6-4), (6-5), (6-7), and (6-8) being more preferred. In the formulas, Ph represents a phenyl group.

[0120] In general formulas (6-1) to (6-12), (7-1) to (7-12), P 5 ~P 8 These are, independently of each other, halogen atoms, C 1-20 Alkyl alkyl group, C 1-20 This represents an alkoxy group, an amino group, a monoalkylamino group, or a dialkylamino group. 5 ~P 8 C in1-20 Alkyl alkyl group, C 1-20 Examples of alkoxy groups, monoalkylamino groups, or dialkylamino groups are, respectively, R g This is similar to the groups listed in (p1)~(p3) and (q1)~(q3). P 5 ~P 8 C 1-20 Alkyl alkyl group, C 1-20 Preferably, it is an alkoxy group, an (unsubstituted) phenyl group, a p-methoxyphenyl group, a p-ethoxyphenyl group, a p-dimethylaminophenyl group, a dimethoxyphenyl group, a thienyl group, or a furanyl group, C 1-10 Alkyl alkyl group or C 1-10 An alkoxy group is more preferable.

[0121] In the general formulas (6-1)~(6-12) and (7-1)~(7-12), n5~n8 represent integers from 0 to 3, independently of each other. In one numerator, P 5 If there are multiple instances of (i.e., n5 is 2 or 3), multiple P 5 These may all be the same type of group or different types of groups. 6 ~P 8 The same applies to this matter.

[0122] [ka]

[0123] [ka]

[0124] [ka]

[0125] [ka]

[0126] Compounds represented by general formulas (6-1) to (6-12) and (7-1) to (7-12) include P 5 ~P 8 C 1-20 Alkyl alkyl group or C 1-20 A compound with an alkoxy group, where n5 to n8 are independently 0 to 2, is preferred, P 5 and P 6 C 1-20 It is an alkyl group, and n5 and n6 are independently 0 to 2, P 7 and P 8 C 1-20 A compound having an alkoxy group, where n7 and n8 are independently 0 to 1, is more preferable, P 5 and P 6 C 1-20 It is an alkyl group, and n5 and n6 are independently 1 to 2, P 7 and P 8 C 1-20 Compounds that are alkoxy groups and have n7 and n8 at 1 are even more preferred.

[0127] Compounds represented by general formulas (6-1) to (6-12) specifically include those represented by the following formulas (6-1-1) to (6-12-1). "λ" is the peak wavelength of the absorption spectrum of each compound, and "Em" is the peak wavelength of the fluorescence spectrum.

[0128] [ka]

[0129] [ka]

[0130] [Pigments] The pigment constituting the colorant composition of the present invention has a value of 0.6 or less obtained by dividing the average absorbance in the range of 730 to 780 nm by the average absorbance in the range of 380 to 730 nm. Preferably, this value is 0.5 or less, more preferably 0.3 or less, and preferably 0.05 or more. When the value obtained by dividing the average absorbance of the pigment in the range of 730 to 780 nm by the average absorbance in the range of 380 to 730 nm is within the above range, it is less likely to interfere with the excitation fluorescence of the near-infrared fluorescent dye contained in the colorant composition of the present invention by irradiation with near-infrared light. Therefore, the decrease in fluorescence intensity is suppressed, fluorescence observation becomes easier, and the ink composition of the present invention, which can be suitably used for traceability and anti-counterfeiting applications, can be prepared from the colorant composition of the present invention. The average particle size (D50) of the pigment is preferably in the range of 50 to 500 nm, and more preferably in the range of 100 to 400 nm. When the average particle size (D50) of the pigment is within the above range, the ink composition of the present invention, which is prepared from the colorant composition of the present invention and described later, becomes easier to handle, and nozzle clogging and other problems are less likely to occur when applying the inkjet method. The average particle diameter (D50) is the volume-based cumulative 50% diameter, and is determined by laser diffraction and scattering.

[0131] Examples of pigments include dioxazine-based pigments, indanthrene-based pigments, diketo-pyrrolo-pyrrole-based pigments, isoindoline-based pigments, and bisbenzofuranone-based pigments. Among these, it is preferable that the colorant composition of the present invention contains a bisbenzofuranone-based pigment. Examples of dioxazine-based pigments include Violet 23, Violet 37, and Blue 80. Examples of indanthron pigments include Blue 60 and Blue 64. Examples of diketopyrrolopyrrole pigments include Red254, Red255, Red264, Orange71, Orange73, and Orange81. Examples of isoindoline pigments include Yellow 139, Yellow 185, Orange 66, Orange 69, and Red 260.

[0132] Bisbenzofuranone pigments may have structures represented by the following general formulas (II) to (V), or their isomers or tautomers. For example, general formulas (II) to (IV) are cis-trans isomers, and there may be two or more of these structures.

[0133] [ka]

[0134] In the formula, R 51 and R 52 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. 53 and R 54 Each is independent of R 60 , OR 61 , SR 61 COR 61 CONR 61 R 62 , NR 61 COR 62 OCOR 61 COOR 61 SCOR 61 OCSR 61 COSR 61 , CSOR 61 , represents a halogen atom or hydroxyl group. Here R 60 R represents an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, an aralkyl group having 7 to 30 carbon atoms, or a heterocyclic group having 2 to 20 carbon atoms. 61 and R 62Each of the following independently represents a hydrogen atom, an alkyl group with 1 to 20 carbon atoms, an aryl group with 6 to 30 carbon atoms, an aralkyl group with 7 to 30 carbon atoms, or a heterocyclic group with 2 to 20 carbon atoms. Each of the following independently represents an integer from 0 to 4.

[0135] Bisbenzofuranone pigments having a structure represented by any of the above general formulas (II) to (V) are publicly known and can be obtained, for example, by the method described in Japanese Patent Publication No. 2012-515233 or by the method described in Example 12b of International Publication No. 2000 / 024736. Commercially available bisbenzofuranone pigments can also be used, such as "Irgaphor® Black S 0100CF" (trade name) manufactured by BASF. Alternatively, it may be bis-oxodihydroindolylene-benzodifuranone represented by general formula (Ia) or (Ib) of Japanese Patent Application Publication No. 2010-534726, or its isomer or tautomer (lactone black). Since bisbenzofuranone pigments have higher light transmittance in the near-infrared region compared to carbon black, it is estimated that the black colorant composition of the present invention containing a bisbenzofuranone pigment will have improved observability of excitation fluorescence upon irradiation with near-infrared light compared to black material forming materials containing carbon black.

[0136] The colorant composition of the present invention may further contain other colorants different from the pigments described above, as long as they do not impair the effects of the present invention. Examples of such other colorants include general organic pigments, inorganic pigments, dyes, etc. When other colorants are included, their amount is preferably 50% by mass or less, and more preferably 30% by mass or less, relative to the content of the pigments described above.

[0137] [Ink composition] The present invention also relates to an ink composition (hereinafter simply referred to as "the ink composition of the present invention") that contains the colorant composition of the present invention described above. The content of the colorant composition of the present invention is preferably in the range of 1 to 30% by mass, and more preferably in the range of 5 to 20% by mass, relative to the total ink composition of the present invention.

[0138] The ink composition of the present invention may contain a pigment dispersant from the viewpoint of further improving the dispersibility of the pigment. As the pigment dispersant, a polymeric dispersant having both a pigment affinity group that chemically binds to or adsorbs to the pigment surface and a polymer chain or group that is solvent-friendly is preferred. Polymeric dispersants improve the wettability of pigments in the dispersion medium, promoting pigment deaggregation. Their steric hindrance and electrostatic repulsion effects stabilize the particle size and viscosity of the pigments, further improving the viscosity and storage stability of the ink composition of the present invention. Examples of polymeric dispersants include polyester-based, acrylic-based, polyurethane-based, polyallylamine-based, carbodiimide-based, and polyamide-based dispersants. Commercially available pigment dispersants can also be used, such as Ajisper (Ajisper is a registered trademark) PB821, PB822, and PB824 from Ajinomoto Fine Techno Co., Ltd.; Solsperse (Solsperse is a registered trademark) 24000GR, 32000, 33000, and 39000 from Lubrizol; Disparon DA-703-50 from Kusumoto Chemical Co., Ltd.; and EFKA (EFKA is a registered trademark) PX4701 and PX4703 from BASF. When the ink composition of the present invention contains a pigment dispersant, the amount is preferably in the range of 10 to 100% by mass, and more preferably in the range of 20 to 60% by mass, relative to the mass of the pigment contained in the ink composition of the present invention, i.e., the pigment constituting the colorant composition. When the pigment dispersant is contained in this range, the pigment dispersibility of the ink composition of the present invention and the discharge stability when used as an inkjet ink tend to be excellent.

[0139] The ink composition of the present invention may further contain surfactants from the viewpoint of adjusting surface tension and improving handling, pigment dispersibility, and discharge stability. Various anionic, nonionic, and cationic surfactants can be appropriately selected as the surfactant. Specifically, examples include anionic surfactants such as dialkyl sulfosuccinates, alkylnaphthalene sulfonates, and fatty acid salts; nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols, and polyoxyethylene-polyoxypropylene block copolymers; cationic surfactants such as alkylamine salts and quaternary ammonium salts; silicone-based surfactants having silicone chains, polymer chains such as silicone chains and poly(meth)acrylate chains, and silicone-based surfactants having polyether chains as side chains or terminals and a polysiloxane structure in the main chain; and preferably hydrophobic organic fluoro compounds such as fluorine-based surfactants having perfluoroalkyl chains, oily fluorine-based compounds (e.g., fluorine oil), and solid fluorine compound resins (e.g., tetrafluoroethylene resin). These can be obtained as commercially available products such as the "MegaFac®" series from DIC Corporation, the "Futergent®" series from Neos Corporation, the "BYK®" series from BYK Corporation, the "TEGO® Rad" series from Evonik Corporation, the "DISPARLON® OX" series from Kusumoto Chemical Co., Ltd., and "Polyflow No. 7," "Florence AC-300," and "Florence AC-303" from Kyoeisha Chemical Co., Ltd. If the ink composition of the present invention contains a surfactant, the amount is preferably 0.05 to 2% by mass, and more preferably 0.1 to 1% by mass, relative to the total amount of the ink composition of the present invention.

[0140] The ink composition of the present invention may contain a solvent. Such solvents include ethers such as 3-methoxy-1-butanol, 3-methoxy-3-methylbutanol, tetrahydrofuran, tetrahydropyran, 1,4-dioxane, anisole, and phenethole; Esters such as methyl lactate, ethyl lactate, butyl lactate, methyl 2-hydroxyisobutanoate, ethyl acetate, butyl acetate, pentyl formate, isopentyl acetate, butyl propionate, isopropyl butyrate, ethyl butyrate, butyl butyrate, methyl pyruvate, methyl acetoacetate, and γ-butyrolactone; Ether esters such as ethyl methoxyacetate, butyl methoxyacetate, methyl ethoxyacetate, ethyl ethoxyacetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, methyl 2-methoxypropionate, ethyl 2-ethoxypropionate, ethyl 2-ethoxypropionate, ethyl 2-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate; Glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol dipropyl ether, and diethylene glycol dibutyl ether; Glycol ether esters such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, and dipropylene glycol methyl ether acetate; Alcohols such as methanol, ethanol, propanol, butanol, hexanol, cyclohexanol, ethylene glycol, and propylene glycol; Ketones such as acetone, 2-butanone, 2-heptanone, 4-methyl-2-pentanone, cyclopentanone, and cyclohexanone; Amides such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone; Aliphatic hydrocarbons such as hexane and octane; Examples include aromatic hydrocarbons such as benzene, toluene, and xylene. If the ink composition of the present invention contains a solvent, the amount is preferably in the range of 10 to 90% by mass, and more preferably in the range of 50 to 80% by mass, relative to the total ink composition of the present invention. The ink composition of the present invention does not necessarily have to contain a solvent. In this specification, "solvent-free" means that the solvent content in the ink composition of the present invention is 1% by mass or less. The solvent content is preferably 0.5% by mass or less, and more preferably 0.1% by mass or less.

[0141] The ink composition of the present invention may further contain additives such as ultraviolet absorbers, antioxidants, leveling agents, fade inhibitors, and conductive salts. Furthermore, from the viewpoint of further improving adhesion to substrates such as plastic substrates, it may also contain acrylic resins, epoxy resins, terpene phenolic resins, rosin esters, etc.

[0142] The ink composition of the present invention can be manufactured by supplying the aforementioned colorant composition of the present invention, a pigment dispersant, and optional components such as various additives as needed, using a conventional disperser such as a bead mill or stirrer, and then stirring and mixing them. When using a bead mill, glass beads or zirconia beads can be used as the beads. In addition to bead mills, various known and conventional dispersers can be used, such as ultrasonic homogenizers, high-pressure homogenizers, paint shakers, ball mills, roll mills, sand mills, sand grinders, Dyno mills, Dispermats, SC mills, nanomizers, etc.

[0143] The ink composition of the present invention can also be suitably applied as an inkjet ink. In the inkjet method, any of the conventionally known methods can be used as the ink ejection method, such as a method that ejects droplets using the vibration of a piezoelectric element (a recording method using an inkjet head that forms ink droplets by the mechanical deformation of an electrostrictive element), a method that utilizes thermal energy, a method that uses an actuator that utilizes electrostatic force, or a method that uses a continuous-jet type charge-controlled head. The viscosity of the ink composition of the present invention at 25°C is preferably in the range of 3 to 30 mPa·s, and more preferably in the range of 5 to 25 mPa·s. Furthermore, the surface tension of the ink composition of the present invention is preferably in the range of 15 to 45 mN / m. When the viscosity and surface tension of the ink composition of the present invention at 25°C are within the above ranges, it is preferable from the viewpoint of improving the handling of the ink composition of the present invention and the inkjet ejection stability when printing by inkjet method.

[0144] Although the colorant composition of the present invention and the ink composition containing the colorant composition of the present invention have been described above, the present invention is not limited to the configuration of the embodiments described above. For example, the colorant composition of the present invention may have additional configurations of any other choice in the configuration of the above embodiments, or may be replaced with any configuration that produces a similar effect. [Examples]

[0145] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples. The compounds used in these examples are shown below.

[0146] <Examples of near-infrared fluorescent dye synthesis> Manufacturing Example 1: Synthesis of Near-Infrared Fluorescent Dye A (1) Under an argon stream, 2.99 g (19.7 mmol) of 4-methoxyphenylboronic acid was placed in a 500 mL three-necked flask and dissolved in 120 mL of toluene. Then, 100 mg of [1,1'-bis(diphenylphosphino)-ferrocene]palladium(II) dichloride-dichloromethane complex (1:1), 30 mL of ethanol, 3.46 g (19.8 mmol) of 5-bromo-2-furaldehyde, and 20 mL of 2 mol / L aqueous sodium carbonate solution were added, and the mixture was stirred at 80°C for 14 hours. The organic phase was separated from the reaction mixture, washed with water and saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The resulting crude product was purified by flash silica gel chromatography (eluent: hexane / ethyl acetate = 19 / 1 → 4 / 1 (volume ratio)) to obtain 5-(4-methoxyphenyl)-furan-2-carboaldehyde (hereinafter referred to as compound (a-1)) as a pale yellow liquid (yield 3.39 g, yield 84.8%). (2) Next, in a 1 L three-necked flask, under a stream of argon, 3.39 g (16.8 mmol) of compound (a-1) and 8.65 g (67.0 mmol) of ethyl azido were dissolved in 300 mL of ethanol. To the resulting solution, 22.8 g (67.0 mmol) of 20% by mass sodium ethoxide ethanol solution was slowly added dropwise in an ice bath, and after the addition was complete, the mixture was stirred for 2 hours. The reaction mixture was then diluted with saturated ammonium chloride aqueous solution to adjust the pH to weakly acidic, filtered, and the recovered solid was washed with water and then dried to obtain 2-azido-3-[5-(4-methoxyphenyl)-furan-2-yl]-ethyl acrylate (hereinafter referred to as compound (a-2)) as a yellow solid (yield 3.31 g, yield 63.1%).

[0147] (3) 3.31 g (10.6 mmol) of compound (a-2) and 60 mL of toluene were placed in a 200 mL round-bottom flask and dissolved, and the mixture was stirred under reflux for 1.5 hours. The resulting solution was concentrated under reduced pressure, and the crude product was recrystallized with a mixture of hexane and ethyl acetate, filtered, and dried to obtain 2-(4-methoxyphenyl)-4H-flu[3.2-b]pyrrole-5-carboxylate ethyl (hereinafter referred to as compound (a-3)) as brown crystals (yield 2.32 g, yield 76.8%). (4) Next, 1.90 g (6.66 mmol) of compound (a-3), 60 mL of ethanol, and an aqueous solution of 3.90 g (97.5 mmol) of sodium hydroxide dissolved in 30 mL of water were added to a 300 mL flask, and the mixture was stirred under reflux for 1 hour. The resulting solution was allowed to cool to 25°C, adjusted to acidity by adding 6 mol / L hydrochloric acid, filtered, and the recovered solid was washed with water and then dried to obtain 2-(4-methoxyphenyl)-4H-flu[3.2-b]pyrrole-5-carboxylic acid (hereinafter referred to as compound (a-4)) as a gray solid (yield 1.56 g, yield 91%).

[0148] (5) 327 mg (5.52 mmol) of compound (a-4) and 16.5 mL of trifluoroacetic acid were placed in a 200 mL three-necked flask and stirred at 45°C. After compound (a-4) dissolved, the mixture was stirred for a further 15 minutes until the foaming subsided. 3.3 mL of anhydrous trifluoroacetic acid was added to this solution and the mixture was reacted at 80°C for 1 hour. The reaction mixture was neutralized with saturated sodium bicarbonate aqueous solution and ice, filtered, and then dried to obtain a black solid (hereinafter referred to as compound (a-5)) (yield 320 mg). (6) 320 mg of compound (a-5) was placed in a 200 mL three-necked flask under an argon stream, and 70 mL of toluene, 1.0 mL of triethylamine, and 1.5 mL of boron trifluoride diethyl ether complex were added sequentially, and the mixture was heated under reflux for 30 minutes. The organic phase was separated by adding saturated sodium bicarbonate aqueous solution to the reaction mixture, and the organic phase was sequentially washed with water and saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The crude product obtained was purified by silica gel column chromatography (eluent: toluene / ethyl acetate = 20 / 1 (volume ratio)) to obtain near-infrared fluorescent dye A as green crystals (yield 20 mg, yield 6%). The synthesis flow of near-infrared fluorescent dye A is shown below.

[0149] [ka]

[0150] 《Manufacturing Example 2: Synthesis of Near-Infrared Fluorescent Dye B》 Near-infrared fluorescent dye B was synthesized as follows, referring to Organic Letters, 2012, Vol. 4, pp. 2670-2673, and Chemistry A European Journal, 2009, Vol. 15, pp. 4857-4864. (1) 25.3 g (212 mmol) of 4-hydroxybenzonitrile, 800 mL of acetone, 100 g (724 mmol) of potassium carbonate, and 48 g (249 mmol) of 1-bromooctane were placed in a 2 L four-necked flask and heated under reflux overnight. After filtering the reaction mixture, the acetone was removed by distillation under reduced pressure. Ethyl acetate was added to the residue to separate the organic phase, which was then washed sequentially with water and saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The resulting crude product was purified by silica gel column chromatography (eluent: hexane / ethyl acetate) to obtain 4-octoxybenzonitrile (hereinafter referred to as compound (b-1)) as a colorless transparent liquid (yield 45.2 g, yield 92%). (2) Next, under an argon stream, 25.18 g (224.4 mmol) of tert-butyloxypotassium and 160 mL of tert-amyl alcohol were placed in a 500 mL four-necked flask. Then, a solution of 14.8 g (64 mmol) of compound (b-1) mixed with 7 mL of tert-amyl alcohol was added, and the mixture was heated under reflux. To this mixture, a solution of 6.5 g (32 mmol) of diisopropyl succinate mixed with 10 mL of tert-amyl alcohol was added dropwise over approximately 3 hours, and after the addition was complete, the mixture was refluxed for 6 hours. After the reaction mixture was allowed to cool to room temperature (25°C), it was placed in a mixed solution of acetic acid:methanol:water = 1:1:1 (volume ratio), and heated again under reflux for several minutes, at which point a red solid precipitated. The solid was filtered off and sequentially washed with heated methanol and water to obtain 3,6-(4-octyloxyphenyl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione (hereinafter referred to as compound (b-2)) as a red solid (yield 5.6g, yield 32%).

[0151] (3) Meanwhile, 10 g (67 mmol) of 4-tert-butylaniline, 70 mL of acetic acid, and 13 g (160 mmol) of sodium thiocyanate were placed in a 200 mL three-necked flask. While maintaining the internal temperature below 15°C, 4.5 mL (87 mmol) of bromine was added dropwise over approximately 20 minutes. After the addition was complete, the mixture was stirred at below 15°C for 3.5 hours. The reaction mixture was added to 150 mL of 28% aqueous ammonia and stirred. After filtering off the precipitated solid, this solid was extracted with diethyl ether. After washing the extract with water, the crude product obtained by concentrating under reduced pressure was purified by silica gel column chromatography (eluent: dichloromethane / ethyl acetate) to obtain 2-amino-6-tert-butylbenzothiazole (hereinafter referred to as compound (b-3)) as a pale yellow solid (yield 10.32 g, yield 69%). (4) Next, 75.4 g (1340 mmol) of potassium hydroxide and 175 mL of ethylene glycol were placed in a 1 L four-necked flask, and the system was cooled with water under an argon atmosphere. Then, 7.8 g (37.8 mmol) of compound (b-3) was added. After bubbling with argon to remove oxygen from the system, the reaction was carried out at 110 °C for 18 hours. The reaction solution was cooled with water to below 40 °C, and 2 mol / L hydrochloric acid, which had been pre-bubbled with argon, was added dropwise to neutralize the pH to around 7, causing a white solid to precipitate. This white solid was filtered off, washed with water, dried under reduced pressure, and further purified by silica gel column chromatography (eluent: hexane / ethyl acetate) to obtain 4-tert-butyl-2-mercaptoaniline (hereinafter referred to as compound (b-4)) as a white solid (yield 2.39 g, yield 35%). (5) Next, 872 mg (14.5 mmol) of acetic acid and 30 mL of acetonitrile were placed in a 100 mL three-necked flask, and the system was replaced with an argon atmosphere. Then, 2.4 g (36.3 mmol) of malononitrile and 2.39 g (13.2 mmol) of compound (b-4) were added sequentially, and the mixture was heated under reflux for 2 hours. Acetonitrile was removed from the reaction mixture under reduced pressure. Ethyl acetate was added to the residue to separate the organic phase, and the organic phase was sequentially washed with water and saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The resulting crude product was purified by silica gel column chromatography (eluent: hexane / ethyl acetate) to obtain 2-(6-tert-butylbenzothiazole-2-yl)acetonitrile (hereinafter referred to as compound (b-5)) as a pale yellow solid (yield 1.98 g, yield 65%).

[0152] (6) Under an argon stream, 1.91 g (3.5 mmol) of compound (b-2), 1.77 g (7.68 mmol) of compound (b-5), and 68 mL of toluene were added to a 200 mL three-necked flask and heated under reflux. 2.56 mL (27.4 mmol) of phosphorus oxychloride was added dropwise to this mixture using a syringe, and the mixture was heated under reflux for a further 2 hours. The reaction mixture was allowed to cool to room temperature (25°C), and while cooling with ice, 40 mL of dichloromethane and 40 mL of saturated sodium bicarbonate aqueous solution were added for extraction. The dichloromethane extract was dried over anhydrous magnesium sulfate and then removed under reduced pressure. The resulting residue was purified by silica gel column chromatography (eluent: hexane / ethyl acetate) to obtain a crude product from which impurities had been roughly removed. This crude product was purified again by silica gel column chromatography (eluent: hexane / dichloromethane) to obtain a green solid (hereinafter referred to as precursor (b-6)) (yield 1.56 g, yield 46%). (7) Under an argon stream, 1.52 g (1.57 mmol) of precursor (b-6), 45 mL of toluene, 4.35 mL (31.4 mmol) of triethylamine, and 7.88 mL (62.7 mmol) of boron trifluoride diethyl ether complex were added to a 200 mL three-necked flask and heated under reflux for 1 hour. The reaction mixture was cooled on ice, and the precipitated solid was filtered off. The mixture was then sequentially washed with water, saturated sodium bicarbonate aqueous solution, 50% methanol aqueous solution, and methanol, and dried under reduced pressure. The obtained solid was dissolved again in toluene, and then methanol was added to precipitate it, yielding a dark green near-infrared fluorescent dye B with the following NMR spectrum (yield 1.25 g, yield 75%). 1 H-NMR (300MHz, CDCl3, ppm): δ7.90 (d, 2H), 7.72-7.69 (m, 6H), 7.51 (dd, 2H), 7.08 (d, 2H), 4.07(t, 4H), 1.84(m, 4H), 1.52(s, 18H), 1.35-1.32(m, 24H), 0.92(t, 6H). The synthesis flow of near-infrared fluorescent dye B is shown below.

[0153] [ka]

[0154] <Pigments> Pigment 1: Bisbenzofuranone pigment, Irgaphor Black S0100CF (manufactured by Sun Chemical Co., Ltd.), average particle size (D50) 350nm Pigment 2: Pigment obtained by mixing Pigment 1 with sodium chloride and diethylene glycol and wet grinding it in a stainless steel kneader (manufactured by Inoue Seisakusho Co., Ltd.), with an average particle size (D50) of 80 nm. Pigment 3: Carbon black, "MCF88" (manufactured by Mitsubishi Chemical Corporation), average particle size (D50) 20nm

[0155] The absorbance spectra of dispersions prepared by dispersing pigments 1 to 3 in propylene glycol monomethyl ether acetate (manufactured by Kuraray Trading Co., Ltd.) at a concentration of 50 ppm were measured using a spectrophotometer U-3900 (manufactured by Hitachi High-Tech Corporation). Based on the obtained absorbance spectra, the values ​​obtained by dividing the average absorbance in the 730-780 nm range by the average absorbance in the 380-730 nm range were 0.46 for pigment 1, 0.2 for pigment 2, and 0.71 for pigment 3.

[0156] 1. Example of manufacturing a colorant composition [Example 1] 0.05 g of near-infrared fluorescent dye A and 9.95 g of pigment 1 were placed in a plastic bag and shaken to obtain colorant composition 1. [Example 2] 0.05 g of near-infrared fluorescent dye B and 9.95 g of pigment 1 were placed in a plastic bag and shaken to obtain colorant composition 2. [Example 3] 0.05 g of near-infrared fluorescent dye B and 9.95 g of pigment 2 were placed in a plastic bag and shaken to obtain colorant composition 3. [Comparative Example 1] 0.05 g of near-infrared fluorescent dye B and 9.95 g of pigment 3 were placed in a plastic bag and shaken to obtain colorant composition C1.

[0157] 2. Examples of ink composition manufacturing [Example 4] Ink composition 1 was obtained by mixing and dispersing 4 parts by mass of colorant composition 1, 1 part by mass of polyvinyl alcohol (manufactured by Merck), 16 parts by mass of water, and 4 parts by mass of ethanol (manufactured by Merck) using a bead mill at 20°C for 2 hours. [Examples 5-6, Comparative Example 2] In Example 4, the same procedure as in Example 4 was followed, except that colorant compositions 2-3 and C1 were used instead of colorant composition 1, to obtain ink compositions 2-3 and C1.

[0158] 3. Evaluation of the ink composition Printed materials 1-3 and C1 were created by printing on paper using ink compositions 1-3 and C1 with an inkjet printer. Upon visual inspection of the blackness of each printed material, no white background was observed in any of the printed materials, and therefore, they were evaluated as having sufficient blackness. Furthermore, the emission intensity (visibility) of each printed material obtained was confirmed using a near-infrared fluorescence detection camera. As the near-infrared fluorescence detection camera, a general-purpose CMOS camera was used, equipped with an LED ring illuminator with a central wavelength of 740 nm as the excitation light source and an optical filter that transmits light with wavelengths longer than 800 nm. Sufficient luminescence intensity was observed in printed materials 1 and 2, and printed material 3 showed even higher luminescence intensity than printed materials 1 and 2. On the other hand, no luminescence was observed in printed material C1. The maximum fluorescence intensity measured with a spectrofluorometer FP-8600 (manufactured by JASCO Corporation) was 110 for printed material 2, 150 for printed material 3, and 20 for printed material C1, with the maximum fluorescence intensity of printed material 1 set to 100.

[0159] Ink compositions 1 to 3 obtained from the colorant composition of the present invention can all be observed to emit fluorescence upon irradiation with near-infrared light. On the other hand, ink composition C2 obtained from a colorant composition in which the black component is carbon black has poor observability of fluorescence emission. The value obtained by dividing the average absorbance in the range of 730 to 780 nm by the average absorbance in the range of 380 to 730 nm is 0.6 or less for pigments 1 and 2, while it is greater than 0.6 for pigment 3. It can be seen that this difference leads to a difference in the confirmation of fluorescence emission. [Industrial applicability]

[0160] The colorant composition of the present invention exhibits strong fluorescence emission intensity in the near-infrared light region, enabling the preparation of a colored ink that is visible under near-infrared light. Such a colored ink can be printed by inkjet printing and is useful for traceability and anti-counterfeiting applications of food and various industrial products.

Claims

1. A colorant composition containing a near-infrared fluorescent dye and a pigment having a maximum absorption wavelength of 900 nm or less and a maximum fluorescence wavelength of 650 nm or more and 900 nm or less, wherein the value obtained by dividing the average absorbance of the pigment in the range of 730 to 780 nm by the average absorbance in the range of 380 to 730 nm is 0.6 or less.

2. The aforementioned near-infrared fluorescent dye is defined by the following general formula (I １ ) 【Chemistry 1】 [In formula (I １ ), R ａ and R ｂ together with the nitrogen atom to which R ａ is attached and the carbon atom to which R ｂ is attached form a condensed aromatic ring formed by condensation of an aromatic 5-membered ring, an aromatic 6-membered ring, or 2 to 3 5-membered rings or 6-membered rings; R ｃ and R ｄ together with the nitrogen atom to which R ｃ is attached and the carbon atom to which R ｄ is attached form a condensed aromatic ring formed by condensation of an aromatic 5-membered ring, an aromatic 6-membered ring, or 2 to 3 5-membered rings or 6-membered rings; R ｅ and R ｆ represent a halogen atom or an oxygen atom; R ｇ represents a hydrogen atom or an electron-withdrawing group. However, R ｅ and R ｆ If it is an oxygen atom, R ｅ , R ｅ The boron atom that bonds with R ａ , and R ａ The nitrogen atoms to which it is bonded may together form a ring, R ｆ , R ｆ The boron atom that bonds with R ｃ , and R ｃ The nitrogen atoms to which it is bonded may together form a ring. R ｅ If it is an oxygen atom and does not form a ring, then R ｅ R is an oxygen atom having a substituent, ｆ If it is an oxygen atom and does not form a ring, then R ｆ is an oxygen atom having a substituent. [The compound represented by ] The following general formula (I ２ ) 【Chemistry 2】 [Form (I ２ ) Medium, R ａ ~R ｆ The compound shown is as defined above. The following general formula (I ３ ) 【Transformation 3】 [Form (I ３ ) Medium, R ｈ and R ｉ R ｈ The nitrogen atom and R to which it is bonded ｉ Together with the carbon atom to which it is bonded, it forms an aromatic five-membered ring, an aromatic six-membered ring, or a condensed aromatic ring formed by the condensation of two or three five-membered or six-membered rings; R ｊ and R ｋ R ｊ The nitrogen atom and R to which it is bonded ｋ Together with the carbon atom to which it is bonded, it forms an aromatic five-membered ring, an aromatic six-membered ring, or a condensed aromatic ring formed by the condensation of two or three five-membered or six-membered rings; R ｌ , R ｍ , R ｎ , and R ｏ These are halogen atoms, C, independently of each other. １－２０ alkyl group, C １－２０ R represents an alkoxy group, an aryl group, or a heteroaryl group; ｐ and R ｑ These are hydrogen atoms, halogen atoms, and C, which are independent of each other. １－２０ alkyl group, C １－２０ R represents an alkoxy group, an aryl group, or a heteroaryl group. ｒ and R ｓ These independently represent a hydrogen atom or an electron-withdrawing group. Compounds represented by ], and The following general formula (I ４ ) 【Chemistry 4】 [Form (I ４ ) Medium, R ｈ ~R ｑ [This is as defined above] The colorant composition according to claim 1, comprising one or more compounds selected from the group consisting of the compounds shown in [the specified formula].

3. The colorant composition according to claim 1, wherein the pigment is a bisbenzofuranone-based pigment.

4. An ink composition containing the colorant composition according to any one of claims 1 to 3.

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