Anthraquinone derivative

Abstract

Provided is an anthraquinone derivative represented by formula (9-1). In formula (9-1), R1 and R2 are each independently an amino group or a hydroxyl group and Y1, Y2, and Z are each independently a hydrogen atom, a C1-C10 alkyl group, a C1-C10 alkoxy group, a cyano group, a nitro group, a halogen atom, a C1-C10 halogenated alkyl group, an amino group, an alkylamino group, a piperidyl group, an aryl group, or a cyclohexyl group, the aryl and cyclohexyl groups being optionally substituted.　

Description

Anthraquinone Derivatives

[0001] The present disclosure relates to anthraquinone derivatives.

[0002] Organic dyes are widely used in various printing inks and optical filters. Development of organic dyes that can be used as dichroic dyes in liquid crystal devices and polarizing films is also progressing. Among organic dyes, many anthraquinone derivatives, which are compounds having an anthraquinone skeleton, are highly stable and robust against light, heat, temperature, etc. Therefore, many studies have been conducted on anthraquinone derivatives that can be used as dyes corresponding to the three primary colors, from the perspectives of controlling absorption wavelength and coloring power, improving solubility in solvents and resins, and improving dichroism. For example, Patent Documents 1 and 2 describe anthraquinone derivatives that can be used as cyan dyes and have an absorption maximum wavelength in the wavelength range of 580 nm or more.

[0003] JP-A No. 63-90568 JP-A No. 63-278994

[0004] It is desirable for a dye to have good lightfastness, i.e., little fading due to light. As mentioned above, many anthraquinone derivatives have high fastness, but anthraquinone derivatives used as cyan dyes tend to have difficulty in achieving lightfastness. Therefore, there is a demand for an anthraquinone derivative that has an absorption maximum wavelength in the wavelength range of 580 nm or more and has good lightfastness.

[0005] One embodiment of the anthraquinone derivative is represented by the following formula (9-1): １ and R ２ are each independently an amino group or a hydroxyl group, and Y １ , Y ２ and Z each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cyano group, a nitro group, a halogen atom, a halogenated alkyl group having 1 to 10 carbon atoms, an amino group, an alkylamino group, a piperidyl group, an aryl group, or a cyclohexyl group, and the aryl group and the cyclohexyl group may have a substituent.

[0006]

[0007] Another embodiment of the anthraquinone derivative is represented by the following formula (1-1): １ , R ２ , and R ３ are each independently an amino group or a hydroxyl group, and R １ , R ２ , and R ３ At least one of Y is a hydroxyl group. １ and Y ２ at least one of Y is an electron-donating group, and the electron-donating group is an alkylamino group, an amino group, or a piperidyl group; １ and Y ２ When only one of Y １ and Y ２ the other is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group, or a cyclohexyl group, and the aryl group and cyclohexyl group may have a substituent. Z is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cyano group, a nitro group, a halogen atom, an amino group, or an alkylamino group.

[0008]

[0009] Another embodiment of the anthraquinone derivative is represented by the following formula (1-1): １ , R ２ , and R ３ are each independently an amino group or a hydroxyl group. １ and Y ２ at least one of Y is an electron-donating group, and the electron-donating group is an acetamide group or a hydroxyl group; １ and Y ２ When only one of Y １ and Y ２the other is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group, or a cyclohexyl group, and the aryl group and cyclohexyl group may have a substituent. Z is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cyano group, a nitro group, a halogen atom, an amino group, or an alkylamino group.

[0010]

[0011] Another embodiment of the anthraquinone derivative is represented by the following formula (2-1): １ , R ２ , and R ３ are each independently an amino group or a hydroxyl group, and R １ , R ２ , and R ３ At least one of Y is a hydroxyl group. １ and Y ２ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group, a cyano group, a nitro group, a halogen atom, an amino group, an alkylamino group, or a cyclohexyl group, and the aryl group and the cyclohexyl group may have a substituent. Z is an electron-withdrawing group, and the electron-withdrawing group is a cyano group or a halogenated alkyl group.

[0012]

[0013] Another embodiment of the anthraquinone derivative is represented by the following formula (2-1): １ , R ２ , and R ３ are each independently an amino group or a hydroxyl group. １ and Y ２are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group, a cyano group, a nitro group, a halogen atom, an amino group, an alkylamino group, or a cyclohexyl group, and the aryl group and the cyclohexyl group may have a substituent. Z is an electron-withdrawing group, and the electron-withdrawing group is an aldehyde group, an acetyl group, or a sulfo group.

[0014]

[0015] Another embodiment of the anthraquinone derivative is represented by the following formula (3-1): １ , R ２ , and R ３ are each independently an amino group or a hydroxyl group, and R １ , R ２ , and R ３ At least one of Y is a hydroxyl group. １ and Y ２ At least one of Y is a cyclohexyl group, and the cyclohexyl group may have a substituent; １ and Y ２ When only one of Y is a cyclohexyl group, １ and Y ２ the other is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group, a cyano group, a nitro group, a halogen atom, an amino group, or an alkylamino group, and the aryl group may have a substituent. Z is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cyano group, a nitro group, a halogen atom, an amino group, or an alkylamino group.

[0016]

[0017] Another embodiment of the anthraquinone derivative is represented by the following formula (8-1): In formula (8-1), A is a direct bond, an oxygen atom, or —NH—; １ , Y ２and Z each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cyano group, a nitro group, a halogen atom, a halogenated alkyl group having 1 to 10 carbon atoms, an amino group, an alkylamino group, an aryl group, a piperidyl group, or a cyclohexyl group, and the aryl group and the cyclohexyl group may have a substituent.

[0018]

[0019] Anthraquinone derivatives of first to ninth embodiments will be described below. In each embodiment, the anthraquinone derivative is a compound having a 9,10-anthraquinone skeleton. Regarding the substitution positions of the anthraquinone skeleton, the 1-, 4-, 5-, and 8-positions are α-positions, and the 2-, 3-, 6-, and 7-positions are β-positions.

[0020] The anthraquinone derivatives of each embodiment are used as dyes. The applications of the dyes are not particularly limited. For example, the anthraquinone derivatives can be used as dyes for inks for sublimation transfer printing and inkjet printing, toners for laser printers and copiers, optical filters such as color filters for liquid crystal display devices and color separation filters used in camera tubes, and inks for anti-tamper and anti-counterfeit printing. The anthraquinone derivatives can also be used as dichroic dyes for guest-host liquid crystal elements and polarizing films.

[0021] The expression "at least one" used in this specification means "one or more" of the desired options. As an example, the expression "at least one" used in this specification means "only one option" or "both of two options" if the number of options is two. As another example, the expression "at least one" used in this specification means "only one option" or "any combination of two or more options" if the number of options is three or more.

[0022] First Embodiment An anthraquinone derivative according to the first embodiment will be described. The anthraquinone derivative according to the first embodiment is a compound represented by the following formula (1-1).

[0023]

[0024] In formula (1-1), R １ , R ２ , and R ３ are each independently an amino group or a hydroxyl group. １ and Y ２ At least one of Y is an electron-donating group, １ and Y ２ When only one of Y １ and Y ２ The other is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group, or a cyclohexyl group, and the aryl group and the cyclohexyl group may have a substituent. The substituent is preferably an alkyl group having 1 to 10 carbon atoms or a cyclic hydrocarbon group. The cyclic hydrocarbon group is preferably a cyclohexyl group or a phenyl group.

[0025] The electron-donating group is preferably an alkylamino group, an amino group, a piperidyl group, an acetamide group, or a hydroxyl group. The alkylamino group may have one or two alkyl groups. The alkyl group in the alkylamino group preferably has 1 to 10 carbon atoms. Y １ and Y ２ When both of Y １ and Y ２ may be the same as or different from each other.

[0026] In formula (1-1), Z is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cyano group, a nitro group, a halogen atom, an amino group, or an alkylamino group. The halogen atom is preferably F, Cl, or Br. The alkylamino group may have one or two alkyl groups. The alkyl group in the alkylamino group preferably has 1 to 10 carbon atoms.

[0027] The function of the anthraquinone derivative of this embodiment will be described. The type of substituent in the anthraquinone skeleton affects the absorption wavelength of the anthraquinone derivative. The anthraquinone derivative of the first embodiment has a substituted or unsubstituted anilino group at the 1-position and amino groups or hydroxyl groups at the 4-, 5-, and 8-positions of the four α-positions. Furthermore, the anthraquinone derivative has substituents at only two of the four β-positions, the 3- and 7-positions, and the substituents are substituted or unsubstituted phenyl groups. An anthraquinone derivative having such a structure has an absorption maximum wavelength in the wavelength range of 600 nm or more, and can therefore be used as a cyan dye.

[0028] Furthermore, one cause of photodegradation in anthraquinone derivatives is thought to be photoreduction in the anthraquinone skeleton, with the resin or the like present around the anthraquinone derivative acting as a hydrogen source. Conventional anthraquinone derivatives are known to have a structure in which a functional group such as a phenyl group is bonded to the β-position via an ether bond. In contrast, in the anthraquinone derivative of the present embodiment, a phenyl group is directly bonded to a carbon atom of the anthraquinone skeleton at the β-position. This structure inhibits the progress of the photoreduction reaction, resulting in high light resistance.

[0029] In detail, when a phenyl group is directly bonded to the β-position, the molecular structure is less likely to rotate at the bond at the β-position compared to when an ether bond is present at the β-position, and therefore the structure of the anthraquinone skeleton after photoreduction is less likely to become a stable structure, which is thought to suppress the progress of the photoreduction reaction.

[0030] Furthermore, it is desirable for the dye to have high tinting power, i.e., high absorbance. Higher tinting power allows for a reduction in the amount of dye used, which is beneficial from a cost perspective. It has been suggested that the greater the overlap between the molecular orbital distributions in the ground state and the excited state of an anthraquinone derivative, the higher the absorbance. Furthermore, the molecular orbital in the ground state is prone to change depending on the molecular structure, such as the substituent, and tends to be broader than the excited state. In contrast, the anthraquinone derivative of the first embodiment has a para-substituted phenyl group containing an electron-donating group at at least one β-position. The electron-donating group in the para-position of the phenyl group suppresses the broadening of the molecular orbital in the ground state, thereby increasing the absorption coefficient and, as a result, enhancing the tinting power of the anthraquinone derivative.

[0031] In the anthraquinone derivative of the first embodiment, the R １ and R ３ is a hydroxyl group, and R ２ is preferably an amino group. Such a compound is represented by the following formula (1-2).

[0032]

[0033] In formula (1-2), Y １ , Y ２ , and Z are defined as in formula (1-1). The anthraquinone derivative represented by formula (1-2) is easy to synthesize. Furthermore, the presence of a hydroxyl group at the α-position tends to cause the above-mentioned photoreduction, but the anthraquinone derivative of this embodiment suppresses the photoreduction reaction due to the structure in which a phenyl group is directly bonded to the β-position as described above. Therefore, it is possible to enjoy the advantages of a structure having a hydroxyl group at the α-position while eliminating the disadvantages of the structure.

[0034] Furthermore, in the anthraquinone derivative of the first embodiment, Y １ and Y ２ It is preferable that both of Y are electron-donating groups. This enhances the controllability of the molecular orbital involved in the above-mentioned photoexcitation in the direction of increasing the absorption coefficient, thereby achieving higher coloring strength. １ and Y２ Each of the groups is preferably an alkylamino group, an amino group, or a piperidyl group. These functional groups have high electron donating properties, which allows for high control of the molecular orbitals involved in the photoexcitation described above. Therefore, higher coloring strength can be obtained.

[0035] Y １ and Y ２ The compound in which each of Y is an alkylamino group or an amino group is represented by the following formula (1-3): １ and Y ２ A compound in which each of the groups is a piperidyl group is represented by the following formula (1-4).

[0036]

[0037] In formula (1-3), Z is defined as in formula (1-1). ４ and R ５ are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

[0038]

[0039] In formula (1-4), Z is defined as in formula (1-1). The anthraquinone derivative of the first embodiment can be produced by using, for example, 1,5-dihydroxy-4,8-dinitroanthraquinone or 1,5-diamino-4,8-dinitroanthraquinone as a starting material and introducing each substituent into the anthraquinone skeleton. A known method may be used to introduce the substituent. For example, the desired substituent can be introduced by utilizing reduction of the nitro group, substitution of the substituent, bromination of the β-position, or substitution of the bromo group.

[0040] Second Embodiment An anthraquinone derivative according to a second embodiment will be described below. The anthraquinone derivative according to the second embodiment is a compound represented by the following formula (2-1).

[0041]

[0042] In formula (2-1), R １ , R ２ , and R ３ are each independently an amino group or a hydroxyl group.１ and Y ２ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group, a cyano group, a nitro group, a halogen atom, an amino group, an alkylamino group, or a cyclohexyl group, and the aryl group and the cyclohexyl group may have a substituent.

[0043] The halogen atom is preferably F, Cl, or Br. The alkylamino group may have one or two alkyl groups. The alkyl group in the alkylamino group preferably has 1 to 10 carbon atoms. The substituent on the aryl group or cyclohexyl group is preferably an alkyl group having 1 to 10 carbon atoms or a cyclic hydrocarbon group. The cyclic hydrocarbon group is preferably a cyclohexyl group or a phenyl group.

[0044] In formula (2-1), Z is an electron-withdrawing group. The electron-withdrawing group is preferably a cyano group, an aldehyde group, an ester group derived from a carboxylic acid, an acetyl group, a sulfo group, a nitro group, or a halogenated alkyl group. The halogen contained in the halogenated alkyl group is preferably F, Cl, or Br. The number of carbon atoms contained in the halogenated alkyl group is preferably 1 to 10.

[0045] The anthraquinone derivative of the second embodiment has, among the four α-positions, a substituted anilino group at the 1-position and amino groups or hydroxyl groups at the 4-, 5-, and 8-positions. The anthraquinone derivative of the second embodiment also has two substituted or unsubstituted phenyl groups at the β-positions. Therefore, like the anthraquinone derivative of the first embodiment, the anthraquinone derivative of the second embodiment also has an absorption maximum wavelength in the wavelength range of 600 nm or more, and can therefore be used as a cyan dye.

[0046] In the anthraquinone derivative of the second embodiment, a phenyl group is directly bonded to a carbon atom constituting the anthraquinone skeleton at the β-position. This structure inhibits the progress of the photoreduction reaction, as in the first embodiment, and thus provides high light resistance.

[0047] Furthermore, the anthraquinone derivative of the second embodiment has a para-substituted anilino group containing an electron-withdrawing group at the α-position. The electron-withdrawing group as the para-substituent in the anilino group reduces the electron density of the aromatic ring of the anilino group, suppressing the expansion of the molecular orbital toward the anilino group. This also controls the molecular orbital involved in photoexcitation to increase the absorption coefficient, thereby enhancing the tinting strength of the anthraquinone derivative. Note that, when the anthraquinone derivative has a phenyl group having an electron-donating group as a para-substituent at the β-position, as in the first embodiment, the effect of improving the tinting strength is further enhanced.

[0048] In the anthraquinone derivative of the second embodiment, the R １ and R ３ is a hydroxyl group, and R ２ is preferably an amino group. Such a compound is represented by the following formula (2-2).

[0049]

[0050] In formula (2-2), Y １ , Y ２ , and Z are defined as in formula (2-1). The anthraquinone derivative represented by formula (2-2) is easy to synthesize. Furthermore, the presence of a hydroxyl group at the α-position tends to cause the above-mentioned photoreduction, but the anthraquinone derivative of this embodiment suppresses the photoreduction reaction due to the structure in which a phenyl group is directly bonded to the β-position as described above. Therefore, it is possible to enjoy the advantages of a structure having a hydroxyl group at the α-position while eliminating the disadvantages of the structure.

[0051] Furthermore, the anthraquinone derivative of the second embodiment is preferably a compound represented by the following formula (2-3).

[0052]

[0053] In formula (2-3), Z is defined as in formula (2-1). ４ and R ５are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a cyclic hydrocarbon group. Many liquid crystal compounds have a cyclohexane ring, and phenylcyclohexane-based liquid crystals are also preferably used. An anthraquinone derivative represented by formula (2-3) can be easily mixed with such liquid crystal materials, and therefore can be preferably used as a dichroic dye together with the liquid crystal material.

[0054] The anthraquinone derivative of the second embodiment can be produced by using, for example, 1,5-dihydroxy-4,8-dinitroanthraquinone or 1,5-diamino-4,8-dinitroanthraquinone as a starting material and introducing each substituent into the anthraquinone skeleton. A known method may be used to introduce the substituent. For example, the desired substituent can be introduced by using reduction of the nitro group, substitution of the substituent, bromination of the β-position, or substitution of the bromo group.

[0055] Third Embodiment An anthraquinone derivative according to a third embodiment will be described. The anthraquinone derivative according to the third embodiment is a compound represented by the following formula (3-1).

[0056]

[0057] In formula (3-1), R １ , R ２ , and R ３ are each independently an amino group or a hydroxyl group. １ and Y ２ At least one of the groups is a cyclohexyl group, and the cyclohexyl group may have a substituent. The substituent on the cyclohexyl group is preferably an alkyl group having 1 to 10 carbon atoms or a cyclic hydrocarbon group. The cyclic hydrocarbon group is preferably a cyclohexyl group or a phenyl group.

[0058] Y １ and Y ２ When only one of Y is a cyclohexyl group, １ and Y ２The other is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group, a cyano group, a nitro group, a halogen atom, an amino group, or an alkylamino group, and the aryl group may have a substituent. The halogen atom is preferably F, Cl, or Br. The alkylamino group may have one or two alkyl groups. The alkyl group in the alkylamino group preferably has 1 to 10 carbon atoms. The substituent in the aryl group is preferably an alkyl group having 1 to 10 carbon atoms or a cyclic hydrocarbon group.

[0059] In formula (3-1), Z is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cyano group, a nitro group, a halogen atom, an amino group, or an alkylamino group. The halogen atom is preferably F, Cl, or Br. The alkylamino group may have one or two alkyl groups. The alkyl group in the alkylamino group preferably has 1 to 10 carbon atoms.

[0060] In the anthraquinone derivative of the third embodiment, the substituent at the α-position is the same as in the first embodiment. Furthermore, the anthraquinone derivative of the third embodiment also has two substituted or unsubstituted phenyl groups at the β-position, similar to the first embodiment. Therefore, the anthraquinone derivative of the third embodiment also has an absorption maximum wavelength in the wavelength range of 600 nm or more, and can therefore be used as a cyan dye.

[0061] In the anthraquinone derivative of the third embodiment, a phenyl group is directly bonded to a carbon atom constituting the anthraquinone skeleton at the β-position. This structure inhibits the progress of the photoreduction reaction, as in the first and second embodiments, and thus provides high light resistance.

[0062] Furthermore, the anthraquinone derivative of the third embodiment has a para-substituted phenyl group at at least one β-position, and the para-substituent on the phenyl group is a substituted or unsubstituted cyclohexyl group. The para-substituent at the β-position allows for control of the molecular orbital involved in photoexcitation, and when the substituent is a cyclohexyl group, absorption in the short wavelength region shifts to the ultraviolet region. As a result, the blue component in the reflected light increases, resulting in a stronger blue tint as a dye. Having a strong blue tint is beneficial for cyan dyes used to correspond to the three primary colors. Therefore, the anthraquinone derivative of the third embodiment can be suitably used as a cyan dye.

[0063] In the anthraquinone derivative of the third embodiment, the R １ and R ３ is a hydroxyl group, and R ２ is preferably an amino group. Such a compound is represented by the following formula (3-2).

[0064]

[0065] In formula (3-2), Y １ , Y ２ , and Z are defined as in formula (3-1). The anthraquinone derivative represented by formula (3-2) is easy to synthesize. Furthermore, the presence of a hydroxyl group at the α-position tends to cause the above-mentioned photoreduction, but the anthraquinone derivative of this embodiment suppresses the photoreduction reaction due to the structure in which a phenyl group is directly bonded to the β-position as described above. Therefore, it is possible to enjoy the advantages of a structure having a hydroxyl group at the α-position while eliminating the disadvantages of the structure.

[0066] Furthermore, the anthraquinone derivative of the third embodiment is preferably a compound represented by the following formula (3-3).

[0067]

[0068] In formula (3-3), Z is defined as in formula (3-1). ４ and R ５are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a cyclic hydrocarbon group. In the anthraquinone derivative represented by formula (3-3), the substituents at the para-positions of the two phenyl groups located at the β-positions are both substituted or unsubstituted cyclohexyl groups. This enhances the effect of suppressing absorption in the short wavelength region, resulting in a stronger blue hue.

[0069] As in the second embodiment, when the anthraquinone derivative has an anilino group at the α-position and an electron-withdrawing group as a substituent at the para-position, the effect of improving coloring power can be obtained. The anthraquinone derivative of the third embodiment can be produced by using, for example, 1,5-dihydroxy-4,8-dinitroanthraquinone or 1,5-diamino-4,8-dinitroanthraquinone as a starting material and introducing each substituent into the anthraquinone skeleton. A known method may be used to introduce the substituent. For example, the desired substituent can be introduced by utilizing reduction of the nitro group, substitution of the substituent, bromination of the β-position, or substitution of the bromo group.

[0070] (Fourth embodiment) An anthraquinone derivative of the fourth embodiment will be described. The anthraquinone derivative of the fourth embodiment is a compound represented by the following formula (4-1), in which the total energy difference ΔE before and after the reaction represented by the following reaction formula (4-2) is −16 kcal / mol or more.

[0071]

[0072]

[0073] In formula (4-1), X is —NH— or a sulfur atom. １ , R ２ , and R ３ are each independently an amino group or a hydroxyl group. １ , and A ２ are each independently a direct bond, an oxygen atom, a sulfur atom, or —NH—. １ , A ２is a direct bond means that a substituted or unsubstituted phenyl group is directly bonded to a carbon atom constituting the anthraquinone skeleton at the β-position of the anthraquinone derivative.

[0074] In formula (4-1), Y １ , Y ２ and Z are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cyano group, a nitro group, a halogen atom, a halogenated alkyl group having 1 to 10 carbon atoms, an amino group, an alkylamino group, a piperidyl group, an aryl group, or a cyclohexyl group, and the aryl group and the cyclohexyl group may have a substituent. The substituent is preferably an alkyl group having 1 to 10 carbon atoms or a cyclic hydrocarbon group. The cyclic hydrocarbon group is preferably a cyclohexyl group or a phenyl group. The halogen atom and the halogen atom contained in the halogenated alkyl group are preferably F, Cl, or Br. The alkylamino group may have one or two alkyl groups. The alkyl group in the alkylamino group preferably has 1 to 10 carbon atoms.

[0075] The above reaction formula (4-2) shows the photoreduction reaction of the anthraquinone derivative represented by the above formula (4-1). In this reaction, photoreduction of the anthraquinone derivative P4 occurs using a resin or the like present around the anthraquinone derivative P4 as a hydrogen source, and a hydrogen adduct K4, which is a compound in which hydrogen is added to the anthraquinone skeleton, is produced.

[0076] The total energy difference ΔE is the value obtained by subtracting the total energy Ep of the anthraquinone derivative P4 from the total energy Ek of the hydrogen adduct K4 (ΔE=Ek−Ep).

[0077] The energies Ep and Ek of the anthraquinone derivative P4 and the hydrogen adduct K4 are determined by quantum chemical calculations using density functional theory (DFT). B3LYP is used as the functional, and 6-31G(d) is used as the basis function. Such quantum chemical calculations can be performed using general-purpose quantum chemical calculation programs such as Gaussian and GAMESS. The energies Ep and Ek are the total energies of the molecules in the optimized structure determined by the quantum chemical calculations.

[0078] The effect of the anthraquinone derivative of the fourth embodiment will be described. An anthraquinone derivative having a substituent as in the above formula (4-1) has a maximum absorption wavelength in the wavelength range of 580 nm or more and 830 nm or less, and therefore can be used as a cyan dye.

[0079] In the anthraquinone derivative of the fourth embodiment, the total energy difference ΔE is -16 kcal / mol or more. One cause of deterioration of anthraquinone derivatives due to light is the reaction shown in the above reaction formula (4-2). The larger the total energy difference ΔE, the less likely the above reaction is to occur. If the total energy difference ΔE is -16 kcal / mol or more, good light resistance can be obtained. Furthermore, in order to obtain even higher light resistance, the total energy difference ΔE is preferably -14 kcal / mol or more.

[0080] In the fourth embodiment, a first example of a suitable anthraquinone derivative is, among the above-mentioned compounds represented by the above formula (4-1), R １ , R ２ , and R ３ In such a compound, the total energy difference ΔE is larger, and therefore high light resistance is obtained. When an anthraquinone derivative has a hydroxyl group at the α-position, it is thought that a photoreduction reaction is more likely to occur. １ , R ２ , and R ３ It is believed that deterioration due to photoreduction reactions can be effectively suppressed by the fact that all of the groups are amino groups.

[0081] In the fourth embodiment, a second example of a suitable anthraquinone derivative is a compound represented by the formula (4-1) above, wherein R １ and R ３ is a hydroxyl group, and R ２ is an amino group, and A １ , A ２ is a compound in which the phenyl group is directly bonded. Such a compound has a larger total energy difference ΔE, and therefore high light resistance. In such a structure, as described in the first embodiment, the phenyl group is directly bonded to the β-position, and it is thought that the three-dimensional structure of the molecule effectively suppresses deterioration due to photoreduction reactions.

[0082] The anthraquinone derivative of the fourth embodiment may be any of the compounds described in the first to third embodiments, as long as the total energy difference ΔE is −16 kcal / mol or more. Even if the compound is different from the compound represented by formula (4-1) among the compounds described in the first to third embodiments, good light resistance can be obtained as long as the total energy difference ΔE is −16 kcal / mol or more.

[0083] Fifth Embodiment An anthraquinone derivative according to the fifth embodiment will be described. The anthraquinone derivative according to the fifth embodiment is a compound represented by the following formula (5-1), and has a 10% weight loss temperature of 350°C or higher in thermogravimetry.

[0084]

[0085] In formula (5-1), X is —NH— or a sulfur atom. １ , R ２ , and R ３ are each independently an amino group or a hydroxyl group. １ , and A ２ are each independently a direct bond, an oxygen atom, a sulfur atom, or —NH—. １ , A ２is a direct bond means that a substituted or unsubstituted phenyl group is directly bonded to a carbon atom constituting the anthraquinone skeleton at the β-position of the anthraquinone derivative.

[0086] In formula (5-1), Y １ , Y ２ and Z are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cyano group, a nitro group, a halogen atom, a halogenated alkyl group having 1 to 10 carbon atoms, an amino group, an alkylamino group, a piperidyl group, an aryl group, or a cyclohexyl group, and the aryl group and the cyclohexyl group may have a substituent. The substituent is preferably an alkyl group having 1 to 10 carbon atoms or a cyclic hydrocarbon group. The cyclic hydrocarbon group is preferably a cyclohexyl group or a phenyl group. The halogen atom and the halogen atom contained in the halogenated alkyl group are preferably F, Cl, or Br. The alkylamino group may have one or two alkyl groups. The alkyl group in the alkylamino group preferably has 1 to 10 carbon atoms.

[0087] The thermogravimetric measurement is carried out under the conditions of a gas flow rate of 200 mL / min and a temperature rise rate of 10°C / min. Air is used as the gas. The action of the anthraquinone derivative of the fifth embodiment will be explained. An anthraquinone derivative having a substituent as represented by the above formula (5-1) has an absorption maximum wavelength in the wavelength range of 580 nm or more and 830 nm or less, and therefore can be used as a cyan dye.

[0088] The anthraquinone derivative of the fifth embodiment has a 10% weight loss temperature of 350°C or higher in the thermogravimetric measurement. When high heat is applied to the anthraquinone derivative, the anthraquinone derivative decomposes to generate radicals, which further promote decomposition and other reactions. Since one cause of photodegradation of anthraquinone derivatives is radicals generated from the surroundings or from the anthraquinone derivative itself, anthraquinone derivatives that are less susceptible to thermal decomposition, i.e., anthraquinone derivatives with a high 10% weight loss temperature, tend to have high light resistance. If the 10% weight loss temperature is 350°C or higher, good light resistance can be obtained. Furthermore, to obtain even higher light resistance, it is preferable that the 10% weight loss temperature be 365°C or higher.

[0089] In the fifth embodiment, a first example of a suitable anthraquinone derivative is, among the above-mentioned compounds represented by the above formula (5-1), R ２ is an amino group. Such compounds are easy to synthesize.

[0090] In the fifth embodiment, a second example of a suitable anthraquinone derivative is, among the above-mentioned compounds represented by the above formula (5-1), R １ and R ３ is a hydroxyl group, and R ２ is an amino group. Such compounds are easy to synthesize.

[0091] In the fifth embodiment, a third example of a suitable anthraquinone derivative is a compound represented by the formula (5-1) above, wherein R １ , R ２ , and R ３ In the case of such a compound, the 10% weight loss temperature is higher, and therefore high light resistance can be obtained.

[0092] In the fifth embodiment, a fourth example of a suitable anthraquinone derivative is a compound represented by the formula (5-1) above, wherein R ２ is an amino group, and A １ and A ２ In such a compound, the 10% weight loss temperature is higher, and therefore high light resistance can be obtained.

[0093] The anthraquinone derivative of the fifth embodiment may be any of the compounds described in the first to third embodiments, so long as it has a 10% weight loss temperature of 350° C. or higher. Even if the compound is different from the compound represented by formula (5-1) among the compounds described in the first to third embodiments, good light resistance can be obtained by having a 10% weight loss temperature of 350° C. or higher.

[0094] Sixth Embodiment A dye is desired to have high coloring power, i.e., high absorbance. The coloring power of an anthraquinone derivative varies depending on the type and position of a substituent possessed by the anthraquinone derivative. Since there are many options for substituents that can be introduced into an anthraquinone derivative, the coloring power of an anthraquinone derivative varies greatly, and many conventional anthraquinone derivatives have low coloring power.

[0095] The higher the coloring power, the more the amount of pigment to be blended can be reduced, which is beneficial from the viewpoint of cost. Furthermore, since anthraquinone derivatives have high molecular planarity and it is difficult to increase solubility, there is a limit to how much the color can be strengthened by increasing the blending amount. Therefore, improving coloring power is an important issue. The anthraquinone derivative of the sixth embodiment aims to improve coloring power.

[0096] An anthraquinone derivative according to a sixth embodiment will be described. In the anthraquinone derivative according to the sixth embodiment, the magnitude of the transition dipole moment calculated by time-dependent density functional theory (TDDFT) is 3.30 D or more and 5.00 D or less.

[0097] The transition dipole moment of an anthraquinone derivative is the electric dipole moment that occurs during an electron transition in vacuum associated with light absorption. The transition dipole moment is calculated using the B3LYP functional and the 6-31G(d) basis function. Such quantum chemistry calculations can be performed using general-purpose quantum chemistry calculation programs such as Gaussian and GAMESS.

[0098] Since the molar extinction coefficient is proportional to the square of the transition dipole moment, the larger the transition dipole moment, the higher the absorbance tends to be. If the magnitude of the transition dipole moment is 3.30 D or more, sufficient absorbance can be obtained, and therefore good coloring strength can be obtained.

[0099] The type and position of the substituents on the anthraquinone derivative affect not only the magnitude of the transition dipole moment but also the magnitude of the maximum absorption wavelength. If the magnitude of the transition dipole moment is 3.30 D or more, both the absorbance and the maximum absorption wavelength can be obtained satisfactorily.

[0100] In addition, if the magnitude of the transition dipole moment is 5.00 D or less, the arrangement and structure of the substituents are prevented from becoming complicated, and therefore synthesis is easy. The anthraquinone derivative of the sixth embodiment is preferably a compound represented by the following formula (6-1).

[0101]

[0102] In formula (6-1), X is —NH— or a sulfur atom. １ , R ２ , and R ３ are each independently an amino group or a hydroxyl group.

[0103] In formula (6-1), Y １ , Y ２and Z are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cyano group, a nitro group, a halogen atom, a halogenated alkyl group having 1 to 10 carbon atoms, an amino group, an alkylamino group, a piperidyl group, an aryl group, or a cyclohexyl group, and the aryl group and the cyclohexyl group may have a substituent. The substituent is preferably an alkyl group having 1 to 10 carbon atoms or a cyclic hydrocarbon group. The cyclic hydrocarbon group is preferably a cyclohexyl group or a phenyl group. The halogen atom and the halogen atom contained in the halogenated alkyl group are preferably F, Cl, or Br. The alkylamino group may have one or two alkyl groups. The alkyl group in the alkylamino group preferably has 1 to 10 carbon atoms.

[0104] An anthraquinone derivative having a substituent, such as that represented by formula (6-1), can increase the transition dipole moment and enhance the maximum absorption wavelength. Specifically, the maximum absorption wavelength is in the wavelength range of 580 nm to 830 nm. Therefore, it can be used as a cyan dye with high coloring power. Furthermore, since a phenyl group is directly bonded to the β-position, good lightfastness can be obtained.

[0105] Among the compounds represented by the above formula (6-1), a first example of a suitable anthraquinone derivative is R １ and R ３ is a hydroxyl group, and R ２ is an amino group. Such compounds are easy to synthesize.

[0106] Among the compounds represented by the above formula (6-1), a second example of a suitable anthraquinone derivative is R ２is an amino group and X is a sulfur atom. Such compounds have both an amino group or a hydroxyl group at the α-position and a phenyl group directly bonded to the β-position, which is a structure that contributes greatly to the long-wavelength shift of the absorption maximum wavelength, and a phenylthio group at the α-position, which is a structure that contributes little to the long-wavelength shift of the absorption maximum wavelength. Therefore, while realizing an absorption maximum wavelength of 580 nm or more that can be used as a cyan dye, the absorption maximum wavelength can be prevented from becoming too large. Specifically, the absorption maximum wavelength can be set in the range of 580 nm or more to 670 nm or less. This allows for an excellent blue hue to be obtained.

[0107] The anthraquinone derivative of the sixth embodiment may be the anthraquinone derivative of the first embodiment. Such a compound can provide high lightfastness and also enhance coloring power due to the action of the para-substituted phenyl group having an electron-donating group at the β-position.

[0108] The anthraquinone derivative of the sixth embodiment may be the anthraquinone derivative of the second embodiment. Such a compound can provide high lightfastness and also enhance coloring power due to the action of the para-substituted anilino group having an electron-withdrawing group at the α-position.

[0109] The anthraquinone derivative of the sixth embodiment may be the anthraquinone derivative of the third embodiment. Such a compound can provide high lightfastness and also provide a strong blue tint due to the action of the para-substituted phenyl group having a cyclohexyl group at the β-position.

[0110] Seventh Embodiment The anthraquinone derivative of the seventh embodiment aims to improve coloring power, similarly to the sixth embodiment.

[0111] The anthraquinone derivative of the seventh embodiment will be described. The anthraquinone derivative of the seventh embodiment is a compound represented by the following formula (7-1), and satisfies the conditions for molecular orbital coefficients described below.

[0112]

[0113] In formula (7-1), C １１ , C １２, C ２１ , C ２２ Each of R is a carbon atom. In formula (7-1), X is —NH— or a sulfur atom. １ , R ２ , and R ３ are each independently an amino group or a hydroxyl group. １ , and A ２ are each independently a direct bond, an oxygen atom, a sulfur atom, or —NH—. １ , A ２ is a direct bond means that a substituted or unsubstituted phenyl group is directly bonded to a carbon atom constituting the anthraquinone skeleton at the β-position of the anthraquinone derivative.

[0114] In formula (7-1), Y １ , Y ２ and Z are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cyano group, a nitro group, a halogen atom, a halogenated alkyl group having 1 to 10 carbon atoms, an amino group, an alkylamino group, a piperidyl group, an aryl group, or a cyclohexyl group, and the aryl group and the cyclohexyl group may have a substituent. The substituent is preferably an alkyl group having 1 to 10 carbon atoms or a cyclic hydrocarbon group. The cyclic hydrocarbon group is preferably a cyclohexyl group or a phenyl group. The halogen atom and the halogen atom contained in the halogenated alkyl group are preferably F, Cl, or Br. The alkylamino group may have one or two alkyl groups. The alkyl group in the alkylamino group preferably has 1 to 10 carbon atoms.

[0115] In the anthraquinone derivative of the seventh embodiment, the molecular orbital coefficient of the highest occupied molecular orbital (HOMO) obtained by quantum chemical calculation using density functional theory (DFT) is: １１ , C １２ , C２１ , C ２２ The average Mv of the square root of the sum of the squares of the coefficients corresponding to the orbitals on each carbon atom is 0.03 or more and 0.2 or less. B3LYP is used as the functional, and 6-31G(d) is used as the basis function.

[0116] That is, C １１ The square root of the sum of the squares of the molecular orbital coefficients for １１ and C １２ The square root of the sum of the squares of the molecular orbital coefficients for １２ and C ２１ The square root of the sum of the squares of the molecular orbital coefficients for ２１ and C ２２ The square root of the sum of the squares of the molecular orbital coefficients for ２２ In this case, M １１ , M １２ , M ２１ , M ２２ The average value of these is the average Mv. The quantum chemical calculations can be performed using a general-purpose quantum chemical calculation program such as Gaussian or GAMESS.

[0117] The effect of the anthraquinone derivative of the seventh embodiment will be described. An anthraquinone derivative having a substituent as in the above formula (7-1) has a maximum absorption wavelength in the wavelength range of 580 nm or more and 830 nm or less, and therefore can be used as a cyan dye.

[0118] Generally, the electronic transition that exhibits the absorption maximum is an electronic transition from HOMO to LUMO (Lowest Unoccupied Molecular Orbital). It is believed that the greater the overlap between the molecular orbitals of the HOMO and LUMO, the higher the probability of electronic transition, and therefore higher absorbance can be obtained. As a result of extensive research by the inventors, a tendency for the molecular orbitals of the HOMO and LUMO to spread in anthraquinone derivatives was discovered.

[0119] That is, the type and arrangement of the substituents have little effect on the LUMO molecular orbital of an anthraquinone derivative, and the LUMO molecular orbital tends to gather around the anthraquinone skeleton. On the other hand, the HOMO molecular orbital varies greatly depending on the type and arrangement of the substituents. Among these, in the structure represented by the above formula (7-1), the HOMO molecular orbital tends to spread toward the α-position to which the anilino group or phenylthio group is bonded, that is, toward the substituent containing X.

[0120] Therefore, if the HOMO molecular orbital is configured to spread toward the substituent at the β-position, that is, if it is configured to spread on the benzene ring contained in the substituent at the β-position, it is thought that the HOMO molecular orbital will be prevented from spreading too much toward the α-position and will spread in a balanced manner around the anthraquinone skeleton, resulting in a large overlap between the molecular orbitals of the HOMO and LUMO.

[0121] The extent to which the HOMO molecular orbital extends over the β-position benzene ring can be expressed by the coefficient of the orbital on the carbon atom contained in the benzene ring. In other words, the larger the average Mv, the greater the extent to which the molecular orbital extends over the β-position benzene ring. If the average Mv is 0.03 or more, the overlap between the HOMO and LUMO molecular orbitals is large enough to obtain good absorbance at the absorption maximum wavelength, resulting in high coloring power. On the other hand, if the average Mv is 0.2 or less, the arrangement and structure of the substituents are prevented from becoming complex, facilitating the synthesis of the anthraquinone derivative. In addition, the HOMO molecular orbital is prevented from spreading too far toward the β-position substituent, thereby reducing the overlap between the HOMO and LUMO molecular orbitals.

[0122] In the seventh embodiment, a first example of a suitable anthraquinone derivative is, among the above-mentioned compounds represented by the above formula (7-1), R １ and R ３ is a hydroxyl group, and R ２ is an amino group. Such compounds are easy to synthesize.

[0123] In the seventh embodiment, a second example of a suitable anthraquinone derivative is, among the above-mentioned compounds represented by the above formula (7-1), R １ and R ３is a hydroxyl group, and R ２ is an amino group, and A １ and A ２ These compounds are anthraquinone derivatives in which the bond is direct. These compounds are easy to synthesize and have high light resistance. They also have a large average Mv.

[0124] The anthraquinone derivative of the seventh embodiment may be any of the compounds described in the first to third embodiments, so long as it has an average Mv of 0.03 or more and 0.2 or less. Even if the compound is different from the compound represented by formula (7-1) among the compounds described in the first to third embodiments, good coloring power can be obtained by having an average Mv of 0.03 or more and 0.2 or less.

[0125] In an anthraquinone derivative, in order to increase the average Mv within the range of 0.03 to 0.2, it is preferable that a substituted or unsubstituted phenyl group be directly bonded to the β-position. Similarly, in order to increase the average Mv within the above range, it is preferable that the anthraquinone derivative has a para-substituted phenyl group at the β-position, and the substituent at the para-position of the phenyl group is an electron-donating group. That is, with the anthraquinone derivative of the first embodiment, good tinting strength can be obtained. Similarly, in order to increase the average Mv within the above range, it is preferable that the anthraquinone derivative has a para-substituted anilino group at the α-position, and the substituent at the para-position of the anilino group is an electron-withdrawing group. That is, with the anthraquinone derivative of the second embodiment, good tinting strength can be obtained.

[0126] Eighth Embodiment The anthraquinone derivative of the eighth embodiment aims to improve light resistance, similarly to the first embodiment.

[0127] The anthraquinone derivative of the eighth embodiment is a compound represented by the following formula (8-1).

[0128]

[0129] In formula (8-1), A is a direct bond, an oxygen atom, or —NH—. A being a direct bond means that a substituted or unsubstituted phenyl group is directly bonded to a carbon atom constituting the anthraquinone skeleton at the β-position of the anthraquinone derivative.

[0130] In formula (8-1), Y １ , Y ２ and Z are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cyano group, a nitro group, a halogen atom, a halogenated alkyl group having 1 to 10 carbon atoms, an amino group, an alkylamino group, an aryl group, a piperidyl group, or a cyclohexyl group, and the aryl group and the cyclohexyl group may have a substituent. The substituent is preferably an alkyl group having 1 to 10 carbon atoms or a cyclic hydrocarbon group. The cyclic hydrocarbon group is preferably a cyclohexyl group or a phenyl group. The halogen atom and the halogen atom contained in the halogenated alkyl group are preferably F, Cl, or Br. The alkylamino group may have one or two alkyl groups. The alkyl group in the alkylamino group preferably has 1 to 10 carbon atoms.

[0131] The type of substituent in the anthraquinone skeleton affects the absorption wavelength of the anthraquinone derivative. The anthraquinone derivative of this embodiment has one substituted or unsubstituted anilino group and three amino groups at the α-position. Anthraquinone derivatives having such a structure have an absorption maximum wavelength in the wavelength range of 600 nm or more, and can therefore be used as cyan dyes.

[0132] One cause of photodegradation in anthraquinone derivatives is thought to be photoreduction in the anthraquinone skeleton, with resins or the like present around the anthraquinone derivative acting as a hydrogen source. If the anthraquinone derivative has a hydroxyl group at the α-position, such photoreduction is more likely to occur. In addition, changes in chemical structure due to the generation of radicals from the hydroxyl group also lead to photodegradation. In contrast, the anthraquinone derivative of this embodiment does not have a hydroxyl group at the α-position, and therefore photodegradation caused by the hydroxyl group is suppressed. Therefore, the anthraquinone derivative of this embodiment can achieve high light resistance.

[0133] In the anthraquinone derivative of this embodiment, A is preferably an oxygen atom or a direct bond. When A is an oxygen atom, the compound is represented by the following formula (8-2), and when A is a direct bond, the compound is represented by the following formula (8-3).

[0134]

[0135] In formula (8-2), Y １ , Y ２ and Z are defined as in formula (8-1). The anthraquinone derivative represented by formula (8-2) can improve the solubility in solvents and resins.

[0136]

[0137] In formula (8-3), Y １ , Y ２ , and Z are defined as in formula (8-1). In the anthraquinone derivative represented by formula (8-3), a substituted or unsubstituted phenyl group is directly bonded to the β-position. This structure further enhances light resistance. In detail, when a phenyl group is directly bonded to the β-position, the molecular structure is less likely to rotate at the bond at the β-position compared to when the β-position is an ether bond or a secondary amine, and therefore the structure after photoreduction of the anthraquinone skeleton is less likely to become a stable structure, which is thought to suppress the progress of the photoreduction reaction.

[0138] The anthraquinone derivative of this embodiment can be produced, for example, by using 1,5-diaminoanthraquinone as a starting material and introducing each substituent into the anthraquinone skeleton. A known method may be used to introduce the substituent. For example, the desired substituent is introduced via nitration at the α-position or bromination at the β-position. The compound represented by the above formula (8-1), which is the anthraquinone derivative of the eighth embodiment, may be any of the anthraquinone derivatives of the first to seventh embodiments.

[0139] Ninth Embodiment As in the first embodiment, the anthraquinone derivative of the ninth embodiment has as its first object the improvement of light resistance.

[0140] Furthermore, among cyan dyes, compounds with an absorption maximum wavelength close to 700 nm have a blue-green color due to an increase in the green component. In contrast, a strong blue tint is desired for cyan dyes used as dyes corresponding to the three primary colors. The anthraquinone derivative of the ninth embodiment has a second objective of improving the blue tint.

[0141] The anthraquinone derivative of the ninth embodiment is a compound represented by the following formula (9-1).

[0142]

[0143] In formula (9-1), R １ and R ２ are each independently an amino group or a hydroxyl group. １ , Y ２ and Z are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cyano group, a nitro group, a halogen atom, a halogenated alkyl group having 1 to 10 carbon atoms, an amino group, an alkylamino group, a piperidyl group, an aryl group, or a cyclohexyl group, and the aryl group and the cyclohexyl group may have a substituent. The substituent is preferably an alkyl group having 1 to 10 carbon atoms or a cyclic hydrocarbon group. The cyclic hydrocarbon group is preferably a cyclohexyl group or a phenyl group.

[0144] The halogen atom and the halogen atom contained in the halogenated alkyl group are preferably F, Cl, or Br. The alkylamino group may have one or two alkyl groups. The alkyl group contained in the alkylamino group preferably has 1 to 10 carbon atoms.

[0145] The function of the anthraquinone derivative of this embodiment will be described. One cause of photodegradation in anthraquinone derivatives is thought to be photoreduction in the anthraquinone skeleton, with resins or the like present around the anthraquinone derivative acting as a hydrogen source. Conventional anthraquinone derivatives are known to have a structure in which a functional group such as a phenyl group is bonded to the β-position via an ether bond. In contrast, in the anthraquinone derivative of this embodiment, a substituted or unsubstituted phenyl group is directly bonded to a carbon atom of the anthraquinone skeleton at the β-position. This structure suppresses the progress of the photoreduction reaction, thereby achieving high light resistance.

[0146] In detail, when a phenyl group is directly bonded to the β-position, the molecular structure is less likely to rotate at the bond at the β-position compared to when an ether bond is present at the β-position, and therefore the structure of the anthraquinone skeleton after photoreduction is less likely to become a stable structure, which is thought to suppress the progress of the photoreduction reaction.

[0147] The type of substituent on the anthraquinone skeleton also affects the absorption wavelength of the anthraquinone derivative. Substituents at the α-position with high electron-donating properties, such as amino, hydroxyl, and anilino groups, act to shift the absorption maximum wavelength to longer wavelengths. Furthermore, structures in which a substituted or unsubstituted phenyl group is directly bonded to the β-position also act to shift the absorption maximum wavelength to longer wavelengths.

[0148] Conventional anthraquinone derivatives, which are cyan dyes, are known to have a structure in which one of the substituents at the α-position is an anilino group and the other three are amino or hydroxyl groups. If such compounds have a structure in which a phenyl group is directly bonded to the β-position in order to improve lightfastness, the absorption maximum wavelength shifts to the longer wavelength side, making it difficult to avoid an increase in the green component in the color exhibited by the compound.

[0149] In contrast, the anthraquinone derivative of the present embodiment has a substituted or unsubstituted phenylthio group at the α-position. The phenylthio group has lower electron donating properties than an amino group, a hydroxyl group, or an anilino group. Therefore, by introducing the phenylthio group at the α-position, the shift of the absorption maximum wavelength to longer wavelengths is suppressed compared to conventional structures, even if a phenyl group is directly bonded to the β-position.

[0150] As described above, the anthraquinone derivative of this embodiment has both a structure that contributes greatly to the long-wavelength shift of the absorption maximum wavelength, namely, an amino group or hydroxyl group at the α-position and a phenyl group directly bonded to the β-position, and a structure that contributes little to the long-wavelength shift of the absorption maximum wavelength, namely, a phenylthio group at the α-position. Therefore, while realizing an absorption maximum wavelength of 580 nm or more that can be used as a cyan dye, the absorption maximum wavelength is prevented from becoming too large. Specifically, the absorption maximum wavelength can be set in the range of 580 nm or more to 670 nm or less, thereby achieving an excellent blue hue. Furthermore, since an excellent blue hue can be obtained while having a structure in which a phenyl group is directly bonded to the β-position, both lightfastness and blue hue can be achieved.

[0151] In the anthraquinone derivative of this embodiment, the R １ and R ２ is preferably a hydroxyl group. Such a compound is represented by the following formula (9-2).

[0152]

[0153] In formula (9-2), Y １ , Y ２ , and Z are defined as in formula (9-1). The anthraquinone derivative represented by formula (9-2) is easy to synthesize. Furthermore, the presence of a hydroxyl group at the α-position tends to cause the above-mentioned photoreduction, but the anthraquinone derivative of this embodiment suppresses the photoreduction reaction due to the structure in which a phenyl group is directly bonded to the β-position as described above. Therefore, it is possible to enjoy the advantages of a structure having a hydroxyl group at the α-position while eliminating the disadvantages of the structure.

[0154] The anthraquinone derivative of this embodiment can be produced by using, for example, 1,5-dihydroxy-4,8-dinitroanthraquinone or 1,5-diamino-4,8-dinitroanthraquinone as a starting material and introducing each substituent into the anthraquinone skeleton. A known method may be used to introduce the substituent. For example, the desired substituent is introduced by reducing the nitro group, converting the substituent, brominating the β-position, or converting the bromo group. The compound represented by the above formula (9-1), which is the anthraquinone derivative of the ninth embodiment, may be the anthraquinone derivative of the fourth to seventh embodiments.

[0155] [Examples] The above-mentioned anthraquinone derivatives will be described using specific examples. Note that the parts by weight of each material below indicate the relative weight ratio of each material to be mixed with each other.

[0156] [First Example: Test Examples Corresponding to First Embodiment] (Test Examples 1-1 to 1-13) <Synthesis of Precursor A1> 1,5-Dihydroxy-4,8-dinitroanthraquinone (5.0 parts by weight) and N,N-dimethylformamide (100 parts by weight) were added to a two-necked recovery flask. N-Bromosuccinimide (5.9 parts by weight) was added thereto at room temperature, and the mixture was stirred at room temperature for 1 hour. After confirming the completion of the reaction by thin-layer chromatography, this reaction solution was added to a sufficient amount of methanol and stirred for 15 minutes. Thereafter, the precipitated solid was collected by suction filtration, and the collected product was vacuum-dried at 60°C overnight to obtain Precursor A1 as a yellow solid. Precursor A1 is a compound represented by the following formula (1-a):

[0157]

[0158] <Synthesis of Precursor A2> Precursor A1 (1.0 parts by weight) and N-methyl-2-pyrrolidone (20 parts by weight) were added to a two-necked recovery flask. 4-heptylaniline (0.8 parts by weight) was then added and heated and stirred in an oil bath at 180°C. After confirming the completion of the reaction by thin-layer chromatography, the reaction solution was allowed to cool to room temperature. Ethyl acetate (30 parts by weight) and water (10 parts by weight) were then added and vigorously stirred at room temperature. Insoluble matter formed during this process was removed by filtration through Celite. After separating the two layers, the organic layer was washed sequentially with distilled water, a 5% aqueous hydrochloric acid solution, and saturated saline, and then dried over anhydrous magnesium sulfate. The desiccant was then filtered off, and the filtrate was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (developing solvent: hexane / dichloromethane = 2 / 1 to 2 / 3), and the resulting solid was dried in vacuo to obtain Precursor A2 as a dark blue solid. Precursor A2 is a compound represented by the following formula (1-b):

[0159]

[0160] <Synthesis of Precursor A3> Precursor A3 was obtained in the same manner as in the synthesis of Precursor A2, except that 4-heptylaniline was replaced with 4-heptyloxyaniline. Precursor A3 is a compound represented by the following formula (1-c).

[0161]

[0162] Synthesis of Dye of Test Example 1-1 Toluene (5 parts by weight), water (2.5 parts by weight), Precursor A2 (0.30 parts by weight, 1 equivalent), 4-dimethylaminophenylboronic acid (0.28 parts by weight, 2.4 equivalents), potassium carbonate (0.21 parts by weight) as a base, and tetrakistriphenylphosphine palladium (0.06 parts by weight) as a catalyst were placed in a recovery flask equipped with a Dimroth condenser and purged with nitrogen, and the mixture was heated and stirred at 80°C for 2 hours. After confirming the completion of the reaction by thin-layer chromatography, the reaction solution was returned to room temperature, purified water was added, and extraction with ethyl acetate was performed. Sodium sulfate was added to the resulting organic layer, which was then dried, and the solvent was removed under reduced pressure using an evaporator. The resulting residue was purified by column chromatography (developing solvent: hexane / ethyl acetate = 10 / 1 to 5 / 1) to obtain the anthraquinone derivative of Test Example 1-1. The anthraquinone derivative of Test Example 1-1 is a compound represented by the following formula (P1-1).

[0163]

[0164] Synthesis of Dye of Test Example 1-2 The anthraquinone derivative of Test Example 1-2 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 1-1, except that 4-dimethylaminophenylboronic acid was changed to 4-dibutylaminophenylboronic acid. The anthraquinone derivative of Test Example 1-2 is a compound represented by the following formula (P1-2).

[0165]

[0166] Synthesis of Dye of Test Example 1-3 The anthraquinone derivative of Test Example 1-3 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 1-1, except that 4-dimethylaminophenylboronic acid was changed to 4-monobutylaminophenylboronic acid. The anthraquinone derivative of Test Example 1-3 is a compound represented by the following formula (P1-3).

[0167]

[0168] Synthesis of Dye of Test Example 1-4 The anthraquinone derivative of Test Example 1-4 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 1-1, except that Precursor A2 was changed to Precursor A3 and 4-dimethylaminophenylboronic acid was changed to 4-monobutylaminophenylboronic acid. The anthraquinone derivative of Test Example 1-4 is a compound represented by the following formula (P1-4).

[0169]

[0170] Synthesis of Dye of Test Example 1-5 The anthraquinone derivative of Test Example 1-5 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 1-1, except that 4-dimethylaminophenylboronic acid was changed to (4-piperidin-1-yl)phenylboronic acid. The anthraquinone derivative of Test Example 1-5 is a compound represented by the following formula (P1-5).

[0171]

[0172] Synthesis of Dye of Test Example 1-6 The anthraquinone derivative of Test Example 1-6 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 1-1, except that 4-dimethylaminophenylboronic acid was changed to 4-aminophenylboronic acid. The anthraquinone derivative of Test Example 1-6 is a compound represented by the following formula (P1-6).

[0173]

[0174] Synthesis of Dye of Test Example 1-7 The anthraquinone derivative of Test Example 1-7 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 1-1, except that 4-dimethylaminophenylboronic acid was changed to 4-acetamidophenylboronic acid. The anthraquinone derivative of Test Example 1-7 is a compound represented by the following formula (P1-7).

[0175]

[0176] Synthesis of Dye of Test Example 1-8 The anthraquinone derivative of Test Example 1-8 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 1-1, except that 4-dimethylaminophenylboronic acid was changed to 4-hydroxyphenylboronic acid. The anthraquinone derivative of Test Example 1-8 is a compound represented by the following formula (P1-8).

[0177]

[0178] <Synthesis of Dye of Test Example 1-9> In the synthesis process of the dye of Test Example 1-1 above, Precursor A2 was changed to Precursor A3, and 1.2 equivalents of 4-monobutylaminophenylboronic acid was added instead of 4-dimethylaminophenylboronic acid, and the reaction solution was stirred at 80°C for 1 hour. After that, 1.2 equivalents of 4-heptylphenylboronic acid was added, and the mixture was heated and stirred at 80°C for 2 hours or more. Thereafter, extraction and purification were carried out in the same manner as in the synthesis process of the dye of Test Example 1-1 above, to obtain the anthraquinone derivative of Test Example 1-9. The anthraquinone derivative of Test Example 1-9 is a compound represented by the following formula (P1-9):

[0179]

[0180] Synthesis of Dye of Test Example 1-10 The anthraquinone derivative of Test Example 1-10 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 1-1, except that 4-dimethylaminophenylboronic acid was changed to 4-heptyloxyphenylboronic acid. The anthraquinone derivative of Test Example 1-10 is a compound represented by the following formula (P1-10).

[0181]

[0182] Synthesis of Dye of Test Example 1-11 The anthraquinone derivative of Test Example 1-11 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 1-1, except that Precursor A2 was changed to Precursor A3 and 4-dimethylaminophenylboronic acid was changed to 4-heptyloxyphenylboronic acid. The anthraquinone derivative of Test Example 1-11 is a compound represented by the following formula (P1-11).

[0183]

[0184] Synthesis of Dye of Test Example 1-12: 4-heptyloxyphenol (8.65 parts by weight) and N-methyl-2-pyrrolidone (100 parts by weight) were placed in a two-necked recovery flask. Sodium hydride (55%, 1.7 parts by weight) was gently added in five portions, and the mixture was stirred in a 60°C oil bath for 3 hours. Precursor A3 (5.00 parts by weight) was added to the solution, and the mixture was heated and stirred in a 130°C oil bath for 24 hours. After confirming the completion of the reaction by thin-layer chromatography, the reaction solution was returned to room temperature, and then ethyl acetate and distilled water were added and the mixture was vigorously stirred at room temperature. After separating the two layers, the organic layer was washed successively with distilled water and saturated saline, and then dried over anhydrous magnesium sulfate. The desiccant was then filtered off, and the filtrate was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (developing solvent: hexane / dichloromethane = 1 / 1 to 1 / 2), and the resulting solid was washed with ethanol and then vacuum dried at 60°C to obtain an anthraquinone derivative of Test Example 1-12. The anthraquinone derivative of Test Example 1-12 is a compound represented by the following formula (P1-12).

[0185]

[0186] Synthesis of Dye of Test Example 1-13 The anthraquinone derivative of Test Example 1-13 was obtained by performing the same synthesis as in the dye synthesis step of Test Example 1-12, except that 4-heptyloxyphenol (8.65 parts by weight) was changed to 4-butylaminophenol (6.86 parts by weight) and Precursor A3 was changed to Precursor A2. The anthraquinone derivative of Test Example 1-13 is a compound represented by the following formula (P1-13).

[0187]

[0188] (Test Examples 1-14 and 1-15) <Synthesis of Precursor B1> 1,5-diaminoanthraquinone (5.0 parts by weight), N,N-dimethylformamide (397 parts by weight), and pyridine (10.3 parts by weight) were placed in a two-neck flask and purged with nitrogen. This solution was thoroughly cooled in an ice bath, and acetyl chloride (19.8 parts by weight) was added dropwise to the solution over 45 minutes while cooling with ice. The solution was then stirred for 10 minutes while cooling with ice, and then stirred at room temperature for 24 hours. The precipitate was then recovered by suction filtration, washed with diethyl ether, and dried to obtain a brown crude product. The crude product (5.5 parts by weight) and ethyl acetate (54 parts by weight) were then placed in a recovery flask, heated to reflux, and subjected to suspension washing for 30 minutes. The recovered product by suction filtration was then washed with diethyl ether and dried at 60°C under reduced pressure to obtain Precursor B1 as a brown powder. Precursor B1 is a compound represented by the following formula (1-d):

[0189]

[0190] <Synthesis of Precursor B2> Concentrated sulfuric acid (48 parts by weight) was placed in a four-neck flask equipped with a thermometer and a mechanical stirrer, and potassium nitrate (6.0 parts by weight) was added and completely dissolved, followed by cooling until the internal temperature of the four-neck flask reached 0°C. Precursor B1 (3.0 parts by weight) was added to this solution in six 0.5 part by weight increments, with the internal temperature of the four-neck flask not exceeding 5°C. After the addition of Precursor B1, a light brown precipitate formed shortly thereafter. After stirring for 6 hours while the internal temperature of the four-neck flask was maintained at 0°C to 5°C, １ Stirring was stopped when disappearance of the substrate was confirmed by H-NMR measurement (solvent: DMSO-d6). This solution was added in small amounts to pure water cooled to 0 to 5°C, and the precipitate was collected by suction filtration. The collected product was dried under reduced pressure at 60°C to obtain a crude product. The crude product was dissolved in nitrobenzene and stirred at 180°C for 30 minutes. After allowing this solution to cool to room temperature, the precipitate collected by filtration was dried under reduced pressure at 60°C to obtain precursor B2 as a dull yellow powder. Precursor B2 is a compound represented by the following formula (1-e):

[0191]

[0192] <Synthesis of Precursor B3> Pure water (5.5 parts by weight) was placed in a two-necked flask, and concentrated sulfuric acid (40 parts by weight) was slowly added thereto while cooling with ice. Precursor B2 (2.2 parts by weight) was then added thereto while cooling with ice. This solution was stirred at 95°C for 2 hours, and then added to pure water (200 parts by weight) while cooling with ice. The precipitate was then collected by suction filtration, and the collected product was dried under reduced pressure at 60°C to obtain Precursor B3 as a red powder. Precursor B3 is a compound represented by the following formula (1-f):

[0193]

[0194] <Synthesis of Precursor B4> Precursor B3 (1.6 parts by weight) and N-bromosuccinimide (1.9 parts by weight) were placed in a two-necked flask and purged with nitrogen. Nitrogen-bubbled N,N-dimethylformamide (30 parts by weight) was added thereto and stirred at room temperature for 20 hours. This reaction solution was poured into methanol (200 parts by weight) and stirred at room temperature for 15 minutes. The precipitate was then collected by suction filtration and dried under reduced pressure at 60°C to obtain Precursor B4 as a reddish-brown powder. Precursor B4 is a compound represented by the following formula (1-g):

[0195]

[0196] <Synthesis of Precursor B5> A recovery flask equipped with a Dimroth condenser was subjected to nitrogen substitution. Toluene (5 parts by weight), water (2.5 parts by weight), Precursor B4 (0.30 parts by weight), (4-piperidin-1-yl)phenylboronic acid (0.28 parts by weight), potassium carbonate (0.21 parts by weight), and tetrakistriphenylphosphine palladium (0.06 parts by weight) were added, and the mixture was heated and stirred at 80°C for at least 2 hours. After confirming the completion of the reaction using thin-layer chromatography, the mixture was returned to room temperature, purified water was added, and extraction with ethyl acetate was performed. Sodium sulfate was added to the resulting organic layer, and the mixture was dried. The solvent was then removed under reduced pressure using an evaporator. The resulting residue was purified using column chromatography (developing solvent: hexane / ethyl acetate = 10 / 1 to 5 / 1) to obtain Precursor B5. Precursor B5 is a compound represented by the following formula (1-h):

[0197]

[0198] <Synthesis of Precursor B6> Precursor B5 (0.20 parts by weight) was placed in a two-neck flask and purged with nitrogen. Nitrobenzene (4.8 parts by weight) and 4-heptylaniline (0.52 parts by weight) were added thereto and stirred at 200°C for 12 hours. The reaction solution was dried under reduced pressure at 75°C to distill off the nitrobenzene and obtain a residue. Methanol was poured into the residue and the precipitated powder was collected by suction filtration to obtain Precursor B6. Precursor B6 is a compound represented by the following formula (1-i):

[0199]

[0200] <Synthesis of Precursor B7> Precursor B7 was obtained in the same manner as in the synthesis of Precursor B5, except that (4-piperidin-1-yl)phenylboronic acid was changed to 4-heptyloxyphenylboronic acid. Precursor B7 is a compound represented by the following formula (1-j).

[0201]

[0202] <Synthesis of Precursor B8> Precursor B8 was obtained in the same manner as in the synthesis of Precursor B6, except that Precursor B5 was replaced with Precursor B7. Precursor B8 is a compound represented by the following formula (1-k).

[0203]

[0204] <Synthesis of Dye of Test Example 1-14> Precursor B6 (0.20 parts by weight) was placed in a two-neck flask and purged with nitrogen. 2-Propanol (3.1 parts by weight) was added thereto, and the mixture was heated to 80°C. Sodium borohydride (0.22 parts by weight) was then added, and the mixture was stirred for 27 hours. This reaction solution was poured into cold water, and the precipitated powder was collected by suction filtration and purified by column chromatography to obtain the anthraquinone derivative of Test Example 1-14. The anthraquinone derivative of Test Example 1-14 is a compound represented by the following formula (P1-14):

[0205]

[0206] Synthesis of Dye of Test Example 1-15 The anthraquinone derivative of Test Example 1-15 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 1-14, except that precursor B6 was changed to precursor B8. The anthraquinone derivative of Test Example 1-15 is a compound represented by the following formula (P1-15).

[0207]

[0208] (Evaluation Method) <Preparation of Evaluation Test Pieces> A dye-containing composition was prepared by mixing the following materials with the anthraquinone derivative of each test example: 45 parts by weight of a mixture of pentaerythritol tetraacrylate and isobornyl acrylate (70% by mass of pentaerythritol tetraacrylate, 30% by mass of isobornyl acrylate), 4.5 parts by weight of a photopolymerization initiator (Omnirad TPO, manufactured by IGM Resins B.V.), 1 part by weight of anthraquinone derivative, and 50 parts by weight of methyl ethyl ketone.

[0209] A 60 μm-thick polyethylene terephthalate film was used as the transparent substrate, and the dye-containing composition was applied to the surface of the transparent substrate, and the coating film was dried in an oven at 80° C. for 60 seconds. Thereafter, an ultraviolet irradiation device (manufactured by Fusion UV Systems Japan, light source H bulb) was used to irradiate the film with an irradiation dose of 150 mJ / cm. ２ The coating film was cured by irradiating it with ultraviolet light at a temperature of 100° C. The thickness of the coating film after curing was adjusted to 8.0 μm, and a test piece for evaluation was prepared.

[0210] <Evaluation of Absorption Wavelength and Tinting Strength> The ultraviolet-visible absorption spectrum of the evaluation test piece of each test example was measured using an automatic spectrophotometer (U-4100, manufactured by Hitachi, Ltd.), and the maximum absorption wavelength λmax and the absorbance at that wavelength were determined.

[0211] In the evaluation of coloring strength, Test Example 1-10 corresponding to a conventional anthraquinone derivative was used as the standard, and when the absorbance was greater than that of Test Example 1-10, it was rated as good (G), and when the absorbance was equal to or less than that of Test Example 1-10, it was rated as bad (B).

[0212] <Evaluation of Light Resistance> A light resistance test was carried out on the evaluation test specimens of each test example using a xenon weather meter tester (X75, manufactured by Suga Test Instruments). In the light resistance test, a UV-cut adhesive film that absorbs light of 395 nm or less was attached to the front surface of the evaluation test specimen, and the test specimens were irradiated with a xenon lamp at an illuminance of 60 W / cm. ２ The test specimen was placed under the conditions of a temperature of 45° C. and a humidity of 50% RH for 120 hours.

[0213] The absorbance of each evaluation test piece before and after the light fastness test was measured using an automatic spectrophotometer (U-4100, manufactured by Hitachi, Ltd.), and the absorbance at the wavelength showing the maximum absorbance in the visible light range was determined. Then, the rate of change in absorbance ΔAbs between before and after the light fastness test was calculated. That is, when the measured value before the light fastness test is absorbance Abs1 and the measured value after the light fastness test is absorbance Abs2, ΔAbs (%) = {(Abs1 - Abs2) / Abs1} × 100.

[0214] In the evaluation of lightfastness, when ΔAbs was 2% or less, it was rated as excellent (E), when ΔAbs was more than 2% and 10% or less, it was rated as good (G), and when ΔAbs was more than 10%, it was rated as bad (B).

[0215] <Measurement of Dichroic Ratio> For each test example, a liquid crystal composition was prepared by mixing an anthraquinone derivative with a cyanocyclohexylbenzene liquid crystal (ZLI-1840, manufactured by Merck) at a ratio of 1.0% by mass. The liquid crystal composition was then injected into a cell to prepare a guest-host liquid crystal element. The cell had a structure in which two glass plates with homogeneously aligned transparent electrodes were arranged facing each other with the alignment-treated surfaces antiparallel. The alignment treatment was performed by applying a polyimide resin to the transparent electrodes, curing the resin, and then performing a rubbing treatment. The cell thickness was 10 μm.

[0216] The liquid crystal element was placed in the optical path of a spectrophotometer, and the absorbance A / / was measured when linearly polarized light parallel to the rubbing direction was applied to the liquid crystal element, and the absorbance A⊥ was measured when linearly polarized light perpendicular to the rubbing direction was applied to the liquid crystal element.The dichroic ratio was calculated as the ratio of absorbance A / / to absorbance A⊥ (A / / / A⊥).

[0217] (Evaluation Results) Table 1 shows the structure of the anthraquinone derivative, the maximum absorption wavelength λmax, the absorbance at the maximum absorption wavelength λmax, the evaluation results of coloring strength, the rate of change in absorbance ΔAbs, the evaluation results of light fastness, and the dichroic ratio for Test Examples 1-1 to 1-15. The structure of the anthraquinone derivative of each Test Example is represented by the following formula (I), and R, A, and Y in Table 1 are １ , Y ２ , Z are R, A, Y in the following formula (I). １ , Y ２ , Z.

[0218]

[0219]

[0220] As shown in Table 1, the anthraquinone derivatives of each test example have a maximum absorption wavelength in the wavelength range of 600 nm or more. Therefore, the anthraquinone derivatives of each test example exhibit a blue color and can be used as cyan dyes.

[0221] Furthermore, Test Examples 1-1 to 1-11, 1-14, and 1-15, in which a substituted phenyl group is directly bonded to the β-position, exhibit extremely high light resistance compared to Test Examples 1-12 and 1-13, in which an ether bond is bonded to the β-position.

[0222] Furthermore, Test Examples 1-1 to 1-9 and 1-14, in which the substituent at the para-position of the directly bonded phenyl group at at least one β-position is an electron-donating group, exhibit higher absorbance and better coloring strength than Test Examples 1-10, 1-11 and 1-15, in which the substituent is not an electron-donating group. Test Examples 1-1 to 1-9 and 1-14 also exhibit higher absorbance than Test Examples 1-12 and 1-13, in which the β-position is an ether bond.

[0223] Furthermore, a comparison of Test Examples 1-3 and 1-9 shows that a higher absorbance is obtained when both of the two phenyl groups at the β-position have an electron-donating group as a substituent, compared to when only one of the substituents is an electron-donating group. Furthermore, Test Examples 1-1 to 1-8 confirm that when the electron-donating group is an alkylamino group, a piperidyl group, or an amino group, the absorbance is more effectively improved than when the electron-donating group is an acetamide group or a hydroxyl group.

[0224] Furthermore, good dichroic ratios were obtained in all test examples, and it was confirmed that in particular, when two hydroxyl groups are present at the α-position, a high dichroic ratio of 10.0 or more can be obtained.

[0225] [Example 2: Test Example Corresponding to the Second Embodiment] In Example 2, synthesis was performed using precursors A1, A2, and A3 similar to those in Example 1. (Test Example 2-1) <Synthesis of Precursor C1> Precursor A1 (1.0 parts by weight) and p-aminobenzonitrile (2.42 parts by weight) were placed in a two-necked recovery flask and nitrogen purging was performed. Nitrobenzene (24 parts by weight) was added to the flask and heated and stirred in an oil bath at 190°C for 5 hours. After cooling the reaction solution to room temperature, the solvent was removed by drying under reduced pressure at 70°C. Methanol was poured into the resulting residue, and the precipitated powder was collected by suction filtration to obtain precursor C1 as a purple powder. Precursor C1 is a compound represented by the following formula (2-a):

[0226]

[0227] <Synthesis of Precursor C2> Precursor C1 (1.0 parts by weight), (4-pentyloxy)phenylboronic acid (1.18 parts by weight), cesium carbonate (1.74 parts by weight), [1,1-bis(diphenylphosphinoferrocene)]dichloropalladium(II) (0.131 parts by weight), and 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (0.147 parts by weight) were placed in a two-necked recovery flask and purged with nitrogen. Toluene (71 parts by weight), ethanol (7.2 parts by weight), and purified water (4.5 parts by weight) were added and stirred in an 80°C oil bath for 2 hours. The reaction solution was cooled to room temperature and separated into dichloromethane and purified water. The organic layer was dried over sodium sulfate. The sodium sulfate was then filtered off, and the remaining solution was concentrated and purified by silica gel column chromatography (developing solvent: dichloromethane / hexane = 1 / 1) to obtain a crude product. This crude product was purified by column chromatography to obtain Precursor C2 as a purple powder. The yield of Precursor C2 was 11%. Precursor C2 is a compound represented by the following formula (2-b).

[0228]

[0229] Synthesis of Dye of Test Example 2-1 Precursor C2 (1 part by weight), iron powder (0.325 parts by weight), and ammonium chloride (0.311 parts by weight) were placed in a two-necked recovery flask and purged with nitrogen. Toluene (27.9 parts by weight), ethanol (8.38 parts by weight), and pure water (5.31 parts by weight) were added, and the mixture was heated and stirred in a 70°C oil bath for 1 hour. The reaction solution was cooled to room temperature, and the insoluble components were filtered through Celite. The mixture was then separated into dichloromethane and pure water, washed with pure water and saturated saline, and the organic layer was dried over sodium sulfate. The sodium sulfate was filtered off, and the remaining solution was concentrated and purified by silica gel column chromatography (developing solvent: dichloromethane / hexane = 2 / 1 to 1 / 1) to obtain the anthraquinone derivative of Test Example 2-1 as a purple powder. The anthraquinone derivative of Test Example 2-1 is a compound represented by the following formula (P2-1):

[0230]

[0231] Test Example 2-2 Synthesis of Precursor C3 Precursor C3 was obtained in the same manner as in the synthesis of Precursor C1, except that p-aminobenzonitrile (2.42 parts by weight) was replaced with p-aminobenzotrifluoride (3.3 parts by weight). Precursor C3 is a compound represented by the following formula (2-c):

[0232]

[0233] <Synthesis of Precursor C4> Precursor C4 was obtained in the same manner as in the synthesis of Precursor C2, except that Precursor C1 was replaced with Precursor C3. Precursor C4 is a compound represented by the following formula (2-d):

[0234]

[0235] Synthesis of Dye of Test Example 2-2 The anthraquinone derivative of Test Example 2-2 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 2-1, except that precursor C2 was changed to precursor C4. The anthraquinone derivative of Test Example 2-2 is a compound represented by the following formula (P2-2).

[0236]

[0237] (Test Example 2-3) <Synthesis of dye of Test Example 2-3> Precursor C5 was obtained by carrying out the same synthesis as in the synthesis step of precursor C2 above, except that (4-pentyloxy)phenylboronic acid was changed to 4-(trans-4-pentylcyclohexyl)phenylboronic acid. Then, the anthraquinone derivative of Test Example 2-3 was obtained by carrying out the same synthesis as in the synthesis step of the dye of Test Example 2-1 above, except that precursor C2 was changed to precursor C5. The anthraquinone derivative of Test Example 2-3 is a compound represented by the following formula (P2-3).

[0238]

[0239] (Test Example 2-4) <Synthesis of Dye of Test Example 2-4> Precursor C6 was obtained by carrying out the same synthesis as in the synthesis step of precursor C2 above, except that precursor C1 was changed to precursor C3 and (4-pentyloxy)phenylboronic acid was changed to 4-(trans-4-pentylcyclohexyl)phenylboronic acid. Then, the anthraquinone derivative of Test Example 2-4 was obtained by carrying out the same synthesis as in the synthesis step of the dye of Test Example 2-1 above, except that precursor C2 was changed to precursor C6. The anthraquinone derivative of Test Example 2-4 is a compound represented by the following formula (P2-4).

[0240]

[0241] (Test Example 2-5) <Synthesis of dye of Test Example 2-5> Precursor C7 was obtained by carrying out the same synthesis as in the synthesis step of precursor C2 above, except that (4-pentyloxy)phenylboronic acid was changed to 4-(dimethylamino)phenylboronic acid. Then, the anthraquinone derivative of Test Example 2-5 was obtained by carrying out the same synthesis as in the synthesis step of the dye of Test Example 2-1 above, except that precursor C2 was changed to precursor C7. The anthraquinone derivative of Test Example 2-5 is a compound represented by the following formula (P2-5).

[0242]

[0243] Test Example 2-6 The dye of Test Example 1-10 in the first embodiment was replaced with the anthraquinone derivative of Test Example 2-6, which is a compound represented by the following formula (P2-6).

[0244]

[0245] Test Example 2-7 The dye of Test Example 1-11 in the first embodiment was replaced with the anthraquinone derivative of Test Example 2-7. The anthraquinone derivative of Test Example 2-7 is a compound represented by the following formula (P2-7).

[0246]

[0247] (Test Example 2-8) <Synthesis of dye of Test Example 2-8> The anthraquinone derivative of Test Example 2-8 was obtained by performing the same synthesis as in Test Example 1-1 of Example 1, except that 4-dimethylaminophenylboronic acid was changed to 4-(trans-4-pentylcyclohexyl)phenylboronic acid. The anthraquinone derivative of Test Example 2-8 is a compound represented by the following formula (P2-8).

[0248]

[0249] (Test Example 2-9) <Synthesis of Dye of Test Example 2-9> The anthraquinone derivative of Test Example 2-9 was obtained by performing the same synthesis as in the dye synthesis step of Test Example 1-1 of Example 1, except that Precursor A2 was changed to Precursor A3 and 4-dimethylaminophenylboronic acid was changed to 4-(trans-4-pentylcyclohexyl)phenylboronic acid. The anthraquinone derivative of Test Example 2-9 is a compound represented by the following formula (P2-9).

[0250]

[0251] Test Example 2-10 The dye of Test Example 1-12 in the first embodiment was replaced with the anthraquinone derivative of Test Example 2-10, which is a compound represented by the following formula (P2-10).

[0252]

[0253] Test Example 2-11 Synthesis of Precursor C8 Precursor C8 was obtained by the same synthesis as in Test Example 1-12 of Example 1, except that Precursor A3 was replaced with Precursor C1. Precursor C8 is a compound represented by the following formula (2-e):

[0254]

[0255] Synthesis of Dye of Test Example 2-11 The anthraquinone derivative of Test Example 2-11 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 2-1, except that precursor C2 was changed to precursor C8. The anthraquinone derivative of Test Example 2-11 is a compound represented by the following formula (P2-11).

[0256]

[0257] (Evaluation Method) For the anthraquinone derivatives of Test Examples 2-1 to 2-11, evaluation specimens were prepared in the same manner as in Example 1, and the absorption wavelength, coloring strength, lightfastness, and dichroic ratio were evaluated. In the evaluation of coloring strength, Test Example 2-6, which corresponds to a conventional anthraquinone derivative, was used as the standard, and cases where the absorbance was greater than that of Test Example 2-6 were rated as good (G), and cases where the absorbance was equal to or less than that of Test Example 2-6 were rated as bad (B).

[0258] (Evaluation Results) Table 2 shows the structure of the anthraquinone derivative, the maximum absorption wavelength λmax, the absorbance at the maximum absorption wavelength λmax, the evaluation results of coloring strength, the rate of change in absorbance ΔAbs, the evaluation results of light fastness, and the dichroic ratio for Test Examples 2-1 to 2-11. The structure of the anthraquinone derivative of each Test Example is represented by the following formula (I), and R, A, and Y in Table 2 are １ , Y ２ , Z are R, A, Y in the following formula (I). １ , Y ２ , Z.

[0259]

[0260]

[0261] As shown in Table 2, the anthraquinone derivatives of each test example have an absorption maximum wavelength in the wavelength range of 600 nm or more. Therefore, the anthraquinone derivatives of each test example exhibit a blue color and can be used as cyan dyes.

[0262] Furthermore, Test Examples 2-1 to 2-9, in which a substituted phenyl group is directly bonded to the β-position, exhibited extremely high light resistance compared to Test Examples 2-10 and 2-11, in which an ether bond is bonded to the β-position.

[0263] Furthermore, in Test Examples 2-1 to 2-5, in which a substituted phenyl group is directly bonded to the β-position and the substituent at the para-position of the anilino group at the α-position is an electron-withdrawing group, the absorbance is higher and good coloring strength is obtained compared to Test Examples 2-6 to 2-9, in which the substituent is not an electron-withdrawing group. Furthermore, Test Examples 2-1 to 2-5 also obtained high absorbance compared to Test Examples 2-10 and 2-11, in which the β-position is an ether bond.

[0264] Furthermore, with reference to Test Examples 2-1 to 2-5, it was confirmed that Test Example 2-5, in which the phenyl group at the β-position has an electron-donating group as a para-substituent in addition to the electron-withdrawing group at the α-position, exhibited particularly high absorbance compared to other Test Examples that did not have such an electron-donating group. It was also confirmed that each Test Example exhibited a good dichroic ratio.

[0265] Third Example: Test Example Corresponding to Third Embodiment In the third example, synthesis was carried out using precursors A1 to A3 and B1 to B4 similar to those in the first example.

[0266] Test Example 3-1 The dye of Test Example 2-8 in the second embodiment was the anthraquinone derivative of Test Example 3-1, which is a compound represented by the following formula (P3-1).

[0267]

[0268] (Test Example 3-2) <Synthesis of dye of Test Example 3-2> The anthraquinone derivative of Test Example 3-2 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 1-1 of Example 1, except that 4-dimethylaminophenylboronic acid was changed to 4-ethylcyclohexylphenylboronic acid. The anthraquinone derivative of Test Example 3-2 is a compound represented by the following formula (P3-2).

[0269]

[0270] (Test Example 3-3) <Synthesis of dye of Test Example 3-3> The anthraquinone derivative of Test Example 3-3 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 1-1 of Example 1, except that 4-dimethylaminophenylboronic acid was changed to 4-methylcyclohexylphenylboronic acid. The anthraquinone derivative of Test Example 3-3 is a compound represented by the following formula (P3-3).

[0271]

[0272] (Test Example 3-4) <Synthesis of dye of Test Example 3-4> The anthraquinone derivative of Test Example 3-4 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 1-1 of Example 1, except that 4-dimethylaminophenylboronic acid was changed to cyclohexylphenylboronic acid. The anthraquinone derivative of Test Example 3-4 is a compound represented by the following formula (P3-4).

[0273]

[0274] Test Example 3-5 The dye of Test Example 2-9 in the second embodiment was the anthraquinone derivative of Test Example 3-5, which is a compound represented by the following formula (P3-5).

[0275]

[0276] (Test Example 3-6) <Synthesis of Dye of Test Example 3-6> In the synthesis step of the dye of Test Example 1-1 of the first embodiment, 1.2 equivalents of 4-heptyloxyphenylboronic acid was added instead of 4-dimethylaminophenylboronic acid, and the reaction solution was stirred at 80°C for 1 hour. After that, 1.2 equivalents of 4-pentylcyclohexylphenylboronic acid was added, and the mixture was heated and stirred at 80°C for 2 hours or more. Thereafter, extraction and purification were carried out in the same manner as in the synthesis step of the dye of Test Example 1-1, to obtain the anthraquinone derivative of Test Example 3-6. The anthraquinone derivative of Test Example 3-6 is a compound represented by the following formula (P3-6):

[0277]

[0278] (Test Example 3-7) <Synthesis of Dye of Test Example 3-7> In the synthesis step of the dye of Test Example 1-1 of the first embodiment, 1.2 equivalents of 4-monobutylaminophenylboronic acid was added instead of 4-dimethylaminophenylboronic acid, and the reaction solution was stirred at 80°C for 1 hour. After that, 1.2 equivalents of 4-pentylcyclohexylphenylboronic acid was added, and the mixture was heated and stirred at 80°C for 2 hours or more. Thereafter, extraction and purification were carried out in the same manner as in the synthesis step of the dye of Test Example 1-1, to obtain the anthraquinone derivative of Test Example 3-7. The anthraquinone derivative of Test Example 3-7 is a compound represented by the following formula (P3-7):

[0279]

[0280] Test Example 3-8 The dye of Test Example 1-10 in the first embodiment was replaced with the anthraquinone derivative of Test Example 3-8. The anthraquinone derivative of Test Example 3-8 is a compound represented by the following formula (P3-8).

[0281]

[0282] Test Example 3-9 The dye of Test Example 1-11 in the first embodiment was replaced with the anthraquinone derivative of Test Example 3-9, which is a compound represented by the following formula (P3-9).

[0283]

[0284] Test Example 3-10 The dye of Test Example 1-3 in the first embodiment was replaced with an anthraquinone derivative of Test Example 3-10, which is a compound represented by the following formula (P3-10).

[0285]

[0286] (Test Example 3-11) <Synthesis of dye of Test Example 3-11> The anthraquinone derivative of Test Example 3-11 was obtained by performing synthesis in the same manner as in Test Example 1-12 of Example 1, except that 4-heptyloxyphenol was changed to 4-heptylcyclohexylphenol and Precursor A3 was changed to Precursor A2. The anthraquinone derivative of Test Example 3-11 is a compound represented by the following formula (P3-11).

[0287]

[0288] Test Example 3-12 Synthesis of Precursor B9 Precursor B9 was obtained in the same manner as in Example 1, except that (4-piperidin-1-yl)phenylboronic acid was replaced with (4-pentylcyclohexyl)phenylboronic acid in the synthesis step of Precursor B5. Precursor B9 is a compound represented by the following formula (3-a).

[0289]

[0290] <Synthesis of Precursor B10> Precursor B10 was obtained by the same synthesis process as in Example 1 for Precursor B6, except that Precursor B5 was replaced with Precursor B9. Precursor B10 is a compound represented by the following formula (3-b).

[0291]

[0292] Synthesis of Dye of Test Example 3-12 The anthraquinone derivative of Test Example 3-12 was obtained by performing synthesis in the same manner as in the synthesis step of the dye of Test Example 1-14 of Example 1, except that precursor B6 was changed to precursor B10. The anthraquinone derivative of Test Example 3-12 is a compound represented by the following formula (P3-12).

[0293]

[0294] Test Example 3-13 The dye of Test Example 1-15 in the first embodiment was replaced with the anthraquinone derivative of Test Example 3-13, which is a compound represented by the following formula (P3-13).

[0295]

[0296] (Evaluation Method) For the anthraquinone derivatives of Test Examples 3-1 to 3-13, evaluation specimens were prepared in the same manner as in Example 1, and the absorption wavelength, light resistance, and dichroic ratio were evaluated.

[0297] The degree of minor absorption was determined by normalizing the absorbance at the maximum absorption wavelength in the ultraviolet-visible absorption spectrum to 1.0, and then using the resulting spectrum, the sum of the absorbance in the short wavelength region from 380 nm to 480 nm was calculated. The sum of the absorbance was an integral value corresponding to the area in the range from 380 nm to 480 nm in the normalized spectrum. The absorption in the short wavelength region from 380 nm to 480 nm was defined as minor absorption.

[0298] (Evaluation Results) Table 3 shows the structure of the anthraquinone derivative, the maximum absorption wavelength λmax, the degree of minor absorption, the rate of absorbance change ΔAbs, the evaluation results of light resistance, and the dichroic ratio for Test Examples 3-1 to 3-13. The structure of the anthraquinone derivative of each Test Example is represented by the following formula (I), and R, A, and Y in Table 3 are １ , Y ２ , Z are R, A, Y in the following formula (I). １ , Y ２ , Z.

[0299]

[0300]

[0301] As shown in Table 3, the anthraquinone derivatives of each test example have an absorption maximum wavelength in the wavelength range of 600 nm or more. Therefore, the anthraquinone derivatives of each test example exhibit a blue color and can be used as cyan dyes.

[0302] Furthermore, Test Examples 3-1 to 3-10, 3-12, and 3-13, in which a substituted phenyl group is directly bonded to the β-position, exhibit extremely high light resistance compared to Test Example 3-11, in which an ether bond is bonded to the β-position.

[0303] Furthermore, a comparison of Test Examples 3-1 to 3-4 with Test Examples 3-8 and 3-10 confirmed that the degree of side absorption can be reduced by using a substituted or unsubstituted cyclohexyl group as the substituent at the para-position of the phenyl group at the β-position. Similarly, a comparison of Test Example 3-5 with Test Example 3-9, and a comparison of Test Example 3-12 with Test Example 3-13 also confirmed that the degree of side absorption is reduced by using a cyclohexyl group as the substituent at the para-position of the β-position. This indicates that an excellent blue color with reduced yellowness can be obtained in an anthraquinone derivative when the substituent at the para-position of the β-position is a cyclohexyl group.

[0304] Furthermore, a comparison between Test Example 3-6 and Test Example 3-8, and a comparison between Test Example 3-7 and Test Example 3-10 confirmed that the effect of suppressing the degree of side absorption can be obtained even when there is only one cyclohexyl group at the para-position of the β-position. Furthermore, a comparison between Test Example 3-1 and Test Examples 3-6 and 3-7 confirmed that when both substituents at the para-position of the β-position are cyclohexyl groups, the effect of suppressing the degree of side absorption is higher than when only one is a cyclohexyl group. Furthermore, a good dichroic ratio was obtained in each test example, and it was confirmed that a high dichroic ratio could be obtained when there were two hydroxyl groups at the α-position.

[0305] Fourth Example: Test Example Corresponding to Fourth Embodiment In the fourth example, synthesis was carried out using the same precursor as in the first to third examples.

[0306] Test Example 4-1 Synthesis of Precursor B11 4-heptyloxyphenol (0.45 parts by weight) and potassium carbonate (0.30 parts by weight) were placed in a two-neck flask and purged with nitrogen. Dehydrated N-methyl-2-pyrrolidone (20 parts by weight) was added and stirred at 120°C for 3 hours. Precursor B4 (0.50 parts by weight) was added to this solution and stirred at 80°C for 7 hours. The reaction solution was returned to room temperature, and water / dichloromethane was added to separate the solution. The organic layer obtained by separation was dried over sodium sulfate and then concentrated using an evaporator. Purification was performed using silica gel column chromatography (developing solvent: hexane / dichloromethane = 1 / 4, with 1% by weight of triethylamine added), and the recovered product was dried under reduced pressure at 60°C to obtain Precursor B11 as a red powder. Precursor B11 is a compound represented by the following formula (4-a):

[0307]

[0308] <Synthesis of Precursor B12> Precursor B11 (0.20 parts by weight) was placed in a two-neck flask and purged with nitrogen. Nitrobenzene (4.8 parts by weight) and 4-heptylaniline (0.52 parts by weight) were added thereto and stirred at 200°C for 12 hours. The reaction solution was dried under reduced pressure at 75°C to distill off the nitrobenzene and obtain a residue. Methanol was poured into the residue and the precipitated powder was collected by suction filtration to obtain Precursor B12 as a purple powder. Precursor B12 is a compound represented by the following formula (4-b):

[0309]

[0310] Synthesis of Dye of Test Example 4-1 The anthraquinone derivative of Test Example 4-1 was obtained by performing synthesis in the same manner as in the synthesis step of the dye of Test Example 1-14 of Example 1, except that precursor B6 was changed to precursor B12. The anthraquinone derivative of Test Example 4-1 is a compound represented by the following formula (P4-1).

[0311]

[0312] Test Example 4-2 The dye of Test Example 1-10 in the first embodiment was replaced with the anthraquinone derivative of Test Example 4-2, which is a compound represented by the following formula (P4-2).

[0313]

[0314] Test Example 4-3 The dye of Test Example 2-8 in the second embodiment was the anthraquinone derivative of Test Example 4-3, which is a compound represented by the following formula (P4-3).

[0315]

[0316] Test Example 4-4 The dye of Test Example 1-11 in the first embodiment was replaced with the anthraquinone derivative of Test Example 4-4, which is a compound represented by the following formula (P4-4).

[0317]

[0318] (Test Example 4-5) <Synthesis of Dye of Test Example 4-5> In the synthesis step of the dye of Test Example 1-1 of the first embodiment, 1.2 equivalents of 4-heptyloxyphenylboronic acid was added instead of 4-dimethylaminophenylboronic acid, and the reaction solution was stirred at 80°C for 1 hour. After that, 1.2 equivalents of 4-pentyloxybiphenylboronic acid was added, and the mixture was heated and stirred at 80°C for 2 hours or more. Thereafter, extraction and purification were carried out in the same manner as in the synthesis step of the dye of Test Example 1-1, to obtain the anthraquinone derivative of Test Example 4-5. The anthraquinone derivative of Test Example 4-5 is a compound represented by the following formula (P4-5):

[0319]

[0320] Test Example 4-6 The dye of Test Example 3-6 of the third embodiment was the anthraquinone derivative of Test Example 4-6, which is a compound represented by the following formula (P4-6).

[0321]

[0322] Test Example 4-7 The dye of Test Example 2-9 of the second embodiment was the anthraquinone derivative of Test Example 4-7. The anthraquinone derivative of Test Example 4-7 is a compound represented by the following formula (P4-7).

[0323]

[0324] Test Example 4-8 The dye of Test Example 2-3 in the second embodiment was replaced with the anthraquinone derivative of Test Example 4-8, which is a compound represented by the following formula (P4-8).

[0325]

[0326] Test Example 4-9 The dye of Test Example 3-7 of the third embodiment was replaced with an anthraquinone derivative of Test Example 4-9, which is a compound represented by the following formula (P4-9).

[0327]

[0328] (Test Examples 4-10 to 4-12) <Synthesis of Precursor D1> Toluene (100 parts by weight), ethanol (20 parts by weight), water (10 parts by weight), Precursor A1 (1 part by weight), 4-pentylcyclohexylphenylboronic acid (1.2 parts by weight), triethylamine (0.62 parts by weight), and tris(dibenzylideneacetone)dipalladium (0.2 parts by weight) were added to a two-necked recovery flask and stirred at 80°C for at least 2 hours. After confirming the completion of the reaction by thin-layer chromatography, the reaction solution was returned to room temperature, purified water was added, and extraction with ethyl acetate was performed. Sodium sulfate was added to the resulting organic layer, which was then dried. The solvent was then removed under reduced pressure using an evaporator. The resulting solid was purified by column chromatography (developing solvent: hexane / dichloromethane = 1 / 1 to 2 / 3) to obtain Precursor D1 as a dark red solid. Precursor D1 is a compound represented by the following formula (4-c):

[0329]

[0330] <Synthesis of Precursor D2> Precursor D2 was obtained in the same manner as in the synthesis of Precursor D1, except that 4-pentylcyclohexylphenylboronic acid was replaced with 4-heptyloxyphenylboronic acid. Precursor D2 is a compound represented by the following formula (4-d):

[0331]

[0332] <Synthesis of Precursor D3> Precursor D3 was obtained in the same manner as in the synthesis of Precursor D1, except that 4-pentylcyclohexylphenylboronic acid was replaced with 4-monobutylaminophenylboronic acid. Precursor D3 is a compound represented by the following formula (4-e):

[0333]

[0334] Synthesis of Dye of Test Example 4-10 Precursor D1 (1.0 parts by weight) was placed in a two-necked recovery flask, and the system was purged with nitrogen. Then, tetrahydrofuran (18.0 parts by weight) was added. Next, using a separate flask, 4-methoxybenzenethiol (3.3 parts by weight) and pyridine (1.6 parts by weight) were mixed and stirred at room temperature for 30 minutes to prepare a solution. This solution was added to the solution containing Precursor D1 in the two-necked recovery flask and heated and stirred at 50°C. After confirming the completion of the reaction using thin-layer chromatography, the reaction solution was allowed to cool to room temperature. Dilute hydrochloric acid (a mixture of 35% hydrochloric acid (20.0 parts by weight) and pure water (80.0 parts by weight)) was then added, and the precipitated solid was collected by filtration. The collected solid (1.0 part by weight) and zinc powder (0.5 parts by weight) were placed in a two-necked recovery flask, and the system was purged with nitrogen. To this mixture, dichloromethane (200.0 parts by weight) and acetic acid (18.0 parts by weight) were added and stirred at room temperature. After confirming the completion of the reaction by thin layer chromatography, the reaction solution was filtered, pure water was added to the filtrate, and the mixture was extracted with dichloromethane. Sodium sulfate was added to the obtained organic layer, and the mixture was dried, and the solvent was removed under reduced pressure using an evaporator. The obtained residue was purified by column chromatography (developing solvent: hexane / dichloromethane = 1 / 1 to 1 / 3) to obtain the anthraquinone derivative of Test Example 4-10 as a dark blue solid. The anthraquinone derivative of Test Example 4-10 is a compound represented by the following formula (P4-10).

[0335]

[0336] Synthesis of Dye of Test Example 4-11 The anthraquinone derivative of Test Example 4-11 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 4-10, except that precursor D1 was changed to precursor D2. The anthraquinone derivative of Test Example 4-11 is a compound represented by the following formula (P4-11).

[0337]

[0338] Synthesis of Dye of Test Example 4-12 The anthraquinone derivative of Test Example 4-12 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 4-10, except that precursor D1 was changed to precursor D3. The anthraquinone derivative of Test Example 4-12 is a compound represented by the following formula (P4-12).

[0339]

[0340] (Test Example 4-13) <Synthesis of Dye of Test Example 4-13> 4-heptyloxyphenol (0.36 parts by weight) and potassium carbonate (0.24 parts by weight) were placed in a two-necked flask and purged with nitrogen. Dehydrated N-methyl-2-pyrrolidone (10 parts by weight) was added and stirred at 120°C for 3 hours. Precursor A2 (0.50 parts by weight) was added thereto and stirred at 120°C for 7 hours. This reaction solution was returned to room temperature, and water / dichloromethane was added and the layers were separated. The resulting organic layer was dried over sodium sulfate and then concentrated using an evaporator. The product was then purified by silica gel column chromatography and dried under reduced pressure at 60°C to obtain the anthraquinone derivative of Test Example 4-13 as a blue powder. The anthraquinone derivative of Test Example 4-13 is a compound represented by the following formula (P4-13).

[0341]

[0342] (Test Example 4-14) <Synthesis of dye of Test Example 4-14> The anthraquinone derivative of Test Example 4-14 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 4-13, except that 4-heptylphenol was used instead of 4-heptyloxyphenol. The anthraquinone derivative of Test Example 4-14 is a compound represented by the following formula (P4-14).

[0343]

[0344] (Test Example 4-15) <Synthesis of Dye of Test Example 4-15> The anthraquinone derivative of Test Example 4-15 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 4-13, except that 4-heptyloxyphenol was changed to 4-heptylcyclohexylphenol. The anthraquinone derivative of Test Example 4-15 is a compound represented by the following formula (P4-15). Note that the anthraquinone derivative of Test Example 4-15 is the same compound as the anthraquinone derivative of Test Example 3-11.

[0345]

[0346] (Evaluation Method) <Evaluation of Absorption Wavelength and Lightfastness> For the anthraquinone derivatives of Test Examples 4-1 to 4-15, evaluation specimens were prepared in the same manner as in Example 1, and the absorption wavelength and lightfastness were evaluated.

[0347] <Calculation of Total Energy Difference ΔE> For the anthraquinone derivatives of Test Examples 4-1 to 4-15, the total energy difference ΔE before and after the reaction represented by the above-mentioned reaction formula (4-2) was calculated. The total energy difference ΔE was calculated using the quantum chemistry calculation program GAMESS, with the functional set to B3LYP and the basis function set to 6-31G(d), according to the following procedure.

[0348] (1) For each anthraquinone derivative of each test example, structural optimization was performed using SCF calculations, and the total molecular energy Ep of the optimized structure was obtained. (2) Using the structure obtained by adding hydrogen to the anthraquinone skeleton of the anthraquinone derivative after structural optimization as the initial structure of the hydrogen adduct, structural optimization of the hydrogen adduct was performed using SCF calculations. Then, the total molecular energy Ek of the optimized structure of the hydrogen adduct was obtained.

[0349] The hydrogen adduct can have four types of stereoisomers depending on the positional relationship of the substituents at the β-position. Of the four types of stereoisomers, it is thought that the most stable structure, which is the structure with the most stable energy, is likely to be formed. Therefore, the most stable structure was adopted as the three-dimensional structure of the hydrogen adduct. The most stable structure was searched for by performing a relaxed scan calculation, which rotates the dihedral angle at the bonding site of the substituent at the β-position. (3) The total energy difference ΔE was calculated using the formula ΔE = Ek - Ep.

[0350] (Evaluation Results) Table 4 shows the structure of the anthraquinone derivative, the absorption maximum wavelength λmax, the total energy difference ΔE, the absorbance change rate ΔAbs, and the evaluation results of light resistance for Test Examples 4-1 to 4-15. The structure of the anthraquinone derivative of each Test Example is represented by the following formula (II), and R, A, X, and Y in Table 4 are １ , Y ２ , Z are R, A, X, and Y in the following formula (II). １ , Y ２ , Z.

[0351]

[0352]

[0353] As shown in Table 4, the anthraquinone derivatives of the test examples have maximum absorption wavelengths in the wavelength range of 580 nm or more, and therefore can be used as cyan dyes.

[0354] Furthermore, high lightfastness was obtained in Test Examples 4-1 to 4-12, in which the total energy difference ΔE was -16 kcal / mol or more. On the other hand, lightfastness was low in Test Examples 4-13 to 4-15, in which the total energy difference ΔE was less than -16 kcal / mol. The results in Table 4 suggest that a structure without a hydroxyl group at the α-position or a structure in which a substituent is directly bonded to the β-position increases the total energy difference ΔE and provides high lightfastness.

[0355] [Fifth Example: Test Example Corresponding to Fifth Embodiment] In the fifth example, synthesis was carried out using the same precursor as in the first to fourth examples. (Test Example 5-1) The dye of Test Example 1-10 in the first example was replaced with the anthraquinone derivative of Test Example 5-1. The anthraquinone derivative of Test Example 5-1 is a compound represented by the following formula (P5-1).

[0356]

[0357] Test Example 5-2 The dye of Test Example 1-11 in the first embodiment was replaced with the anthraquinone derivative of Test Example 5-2, which is a compound represented by the following formula (P5-2).

[0358]

[0359] (Test Example 5-3) <Synthesis of Dye of Test Example 5-3> In the synthesis process of the dye of Test Example 1-1 of the first embodiment, Precursor A2 was changed to Precursor A3, and 1.2 equivalents of 4-heptyloxyphenylboronic acid was added instead of 4-dimethylaminophenylboronic acid, and the reaction solution was stirred at 80°C for 1 hour. After that, 1.2 equivalents of 4-(trans-4-pentylcyclohexyl)phenylboronic acid was added, and the mixture was heated and stirred at 80°C for 2 hours or more. Thereafter, extraction and purification were performed in the same manner as in the synthesis process of the dye of Test Example 1-1, to obtain the anthraquinone derivative of Test Example 5-3. The anthraquinone derivative of Test Example 5-3 is a compound represented by the following formula (P5-3).

[0360]

[0361] Test Example 5-4 The dye of Test Example 1-2 in the first embodiment was replaced with an anthraquinone derivative of Test Example 5-4, which is a compound represented by the following formula (P5-4).

[0362]

[0363] (Test Example 5-5) <Synthesis of dye of Test Example 5-5> The anthraquinone derivative of Test Example 5-5 was obtained by performing the same synthesis as in Test Example 4-10 of Example 4, except that precursor D1 was changed to precursor D2 and 4-methoxybenzenethiol was changed to 4-heptyloxybenzenethiol in the dye synthesis step. The anthraquinone derivative of Test Example 5-5 is a compound represented by the following formula (P5-5).

[0364]

[0365] Test Example 5-6 The dye of Test Example 4-11 in the fourth embodiment was the anthraquinone derivative of Test Example 5-6, which is a compound represented by the following formula (P5-6).

[0366]

[0367] (Test Example 5-7) <Synthesis of dye of Test Example 5-7> The anthraquinone derivative of Test Example 5-7 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 4-10 of Example 4, except that 4-methoxybenzenethiol was changed to 4-heptyloxybenzenethiol. The anthraquinone derivative of Test Example 5-7 is a compound represented by the following formula (P5-7).

[0368]

[0369] (Test Example 5-8) <Synthesis of dye of Test Example 5-8> The anthraquinone derivative of Test Example 5-8 was obtained by performing the same synthesis as in Test Example 4-10 of Example 4, except that precursor D1 was changed to precursor D2 and 4-methoxybenzenethiol was changed to 4-cyanobenzenethiol. The anthraquinone derivative of Test Example 5-8 is a compound represented by the following formula (P5-8).

[0370]

[0371] Test Example 5-9 Synthesis of Precursor B13 Precursor B13 was obtained in the same manner as in Example 1, except that precursor A1 was replaced with precursor B4 in the synthesis step of precursor A2. Precursor B13 is a compound represented by the following formula (5-a).

[0372]

[0373] <Synthesis of Dye of Test Example 5-9> The anthraquinone derivative of Test Example 5-9 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 1-1 of the first embodiment, except that precursor A2 was changed to precursor B13 and 4-dimethylaminophenylboronic acid was changed to 4-heptyloxyphenylboronic acid. The anthraquinone derivative of Test Example 5-9 is a compound represented by the following formula (P5-9). Note that the anthraquinone derivative of Test Example 5-9 is the same compound as the anthraquinone derivative of Test Example 1-15.

[0374]

[0375] Test Example 5-10 The dye of Test Example 4-1 in the fourth embodiment was replaced with an anthraquinone derivative of Test Example 5-10, which is a compound represented by the following formula (P5-10).

[0376]

[0377] Test Example 5-11 The dye of Test Example 4-13 in the fourth embodiment was replaced with the anthraquinone derivative of Test Example 5-11, which is a compound represented by the following formula (P5-11).

[0378]

[0379] Test Example 5-12 The dye of Test Example 4-14 in the fourth embodiment was the anthraquinone derivative of Test Example 5-12, which is a compound represented by the following formula (P5-12).

[0380]

[0381] (Evaluation Method) <Evaluation of Absorption Wavelength and Lightfastness> For the anthraquinone derivatives of Test Examples 5-1 to 5-12, evaluation specimens were prepared in the same manner as in Example 1, and the absorption wavelength and lightfastness were evaluated.

[0382] <Thermogravimetric Measurement> Weights of the anthraquinone derivatives of Test Examples 5-1 to 5-12 were measured using a simultaneous thermogravimetric and differential thermal analyzer (STA7200RV, manufactured by Hitachi High-Tech Science) under conditions of a gas flow rate of 200 mL / min and a temperature rise rate of 10°C / min, while raising the temperature from 30°C to 550°C. Air was used as the gas. The 10% weight loss temperature was determined based on the weight at the start of the temperature rise.

[0383] (Evaluation Results) Table 5 shows the structure of the anthraquinone derivative, the absorption maximum wavelength λmax, the 10% weight loss temperature, the absorbance change rate ΔAbs, and the evaluation results of light resistance for Test Examples 5-1 to 5-12. The structure of the anthraquinone derivative of each Test Example is represented by the following formula (II), and R, A, X, and Y in Table 5 are １ , Y ２ , Z are R, A, X, and Y in the following formula (II). １ , Y ２ , Z.

[0384]

[0385]

[0386] As shown in Table 5, the anthraquinone derivatives of the test examples have maximum absorption wavelengths in the wavelength range of 580 nm or more, and therefore can be used as cyan dyes.

[0387] High light resistance was obtained in Test Examples 5-1 to 5-10, in which the 10% weight loss temperature was 350° C. or higher. On the other hand, light resistance was low in Test Examples 5-111 and 5-12, in which the 10% weight loss temperature was less than 350° C.

[0388] The results in Table 5 suggest that structures without a hydroxyl group at the α-position or structures in which a substituent is directly bonded to the β-position have a higher 10% weight loss temperature and higher light resistance. It was also confirmed that structures in which X is -NH- tend to have higher 10% weight loss temperature and light resistance than structures in which X is a sulfur atom. １ , Y ２ It was confirmed that when is an electron donating group such as an alkylamino group, the 10% weight loss temperature and light resistance tend to decrease.

[0389] Sixth Example: Test Example Corresponding to Sixth Embodiment In the sixth example, synthesis was carried out using the same precursor as in the first to fifth examples.

[0390] Test Example 6-1 The dye of Test Example 1-11 in the first embodiment was replaced with the anthraquinone derivative of Test Example 6-1, which is a compound represented by the following formula (P6-1).

[0391]

[0392] Test Example 6-2 The dye of Test Example 2-8 in the second embodiment was the anthraquinone derivative of Test Example 6-2, which is a compound represented by the following formula (P6-2).

[0393]

[0394] Test Example 6-3 The dye of Test Example 1-3 in the first embodiment was replaced with an anthraquinone derivative of Test Example 6-3, which is a compound represented by the following formula (P6-3).

[0395]

[0396] Test Example 6-4 The dye of Test Example 1-2 in the first embodiment was replaced with an anthraquinone derivative of Test Example 6-4, which is a compound represented by the following formula (P6-4).

[0397]

[0398] (Test Example 6-5) <Synthesis of Dye of Test Example 6-5> In the synthesis step of the dye of Test Example 1-1 of the first embodiment, 1.2 equivalents of 4-(trans-4-pentylcyclohexyl)phenylboronic acid was added instead of 4-dimethylaminophenylboronic acid, and the reaction solution was stirred at 80°C for 1 hour. After that, 1.2 equivalents of 4-pentyloxybiphenylboronic acid was added, and the mixture was heated and stirred at 80°C for 2 hours or more. Thereafter, extraction and purification were carried out in the same manner as in the synthesis step of the dye of Test Example 1-1 above, to obtain the anthraquinone derivative of Test Example 6-5. The anthraquinone derivative of Test Example 6-5 is a compound represented by the following formula (P6-5):

[0399]

[0400] (Test Example 6-6) <Synthesis of Dye of Test Example 6-6> In the synthesis step of the dye of Test Example 1-1 of the first embodiment, 1.2 equivalents of 4-(trans-4-pentylcyclohexyl)phenylboronic acid was added instead of 4-dimethylaminophenylboronic acid, and the reaction solution was stirred at 80°C for 1 hour. After that, 1.2 equivalents of 4-monobutylaminophenylboronic acid was added, and the mixture was heated and stirred at 80°C for 2 hours or more. Thereafter, extraction and purification were carried out in the same manner as in the synthesis step of the dye of Test Example 1-1, to obtain the anthraquinone derivative of Test Example 6-6. The anthraquinone derivative of Test Example 6-6 is a compound represented by the following formula (P6-6):

[0401]

[0402] Test Example 6-7 The dye of Test Example 5-5 in the fifth embodiment was replaced with the anthraquinone derivative of Test Example 6-7, which is a compound represented by the following formula (P6-7).

[0403]

[0404] Test Example 6-8 The dye of Test Example 4-12 in the fourth embodiment was the anthraquinone derivative of Test Example 6-8. The anthraquinone derivative of Test Example 6-8 is a compound represented by the following formula (P6-8).

[0405]

[0406] Test Example 6-9 The dye of Test Example 5-7 of the fifth embodiment was replaced with an anthraquinone derivative of Test Example 6-9, which is a compound represented by the following formula (P6-9).

[0407]

[0408] Test Example 6-10 Synthesis of Precursor B14 Precursor B14 was obtained by the same synthesis as in Example 1, except that precursor A1 was replaced with precursor B4 and 4-heptyloxyaniline was used instead of 4-heptylaniline in the synthesis step of precursor A2. Precursor B14 is a compound represented by the following formula (6-a).

[0409]

[0410] Synthesis of Dye of Test Example 6-10 The anthraquinone derivative of Test Example 6-10 was obtained by performing the same synthesis as in Test Example 1-1 of Example 1, except that Precursor A2 was changed to Precursor B14 and 4-dimethylaminophenylboronic acid was changed to 4-heptyloxyphenylboronic acid. The anthraquinone derivative of Test Example 6-10 is a compound represented by the following formula (P6-10).

[0411]

[0412] (Test Example 6-11) <Synthesis of dye of Test Example 6-11> The anthraquinone derivative of Test Example 6-11 was obtained by performing synthesis in the same manner as in Test Example 4-13 of Example 4, except that 4-heptyloxyphenol was changed to 4-(trans-4-pentylcyclohexyl)phenol in the dye synthesis step. The anthraquinone derivative of Test Example 6-11 is a compound represented by the following formula (P6-11).

[0413]

[0414] Test Example 6-12 Synthesis of Precursor D4 Precursor D4 was obtained in the same manner as in Example 4, except that precursor B4 was replaced with precursor A1. Precursor D4 is a compound represented by the following formula (6-b).

[0415]

[0416] Synthesis of Dye of Test Example 6-12 The anthraquinone derivative of Test Example 6-12 was obtained by performing the same synthesis as in Test Example 4-10 of Example 4, except that precursor D1 was changed to precursor D4 and 4-methoxybenzenethiol was changed to 4-heptyloxybenzenethiol. The anthraquinone derivative of Test Example 6-12 is a compound represented by the following formula (P6-12).

[0417]

[0418] (Test Example 6-13) <Synthesis of dye of Test Example 6-13> The anthraquinone derivative of Test Example 6-13 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 4-13 of the fourth embodiment, except that 4-heptyloxyphenol was changed to 4-monobutylaminophenol. The anthraquinone derivative of Test Example 6-13 is a compound represented by the following formula (P6-13). Note that the anthraquinone derivative of Test Example 6-13 is the same compound as the anthraquinone derivative of Test Example 1-13.

[0419]

[0420] (Evaluation Method) <Evaluation of Absorption Wavelength and Tinting Strength> For the anthraquinone derivatives of Test Examples 6-1 to 6-13, evaluation specimens were prepared in the same manner as in the first example.

[0421] For the evaluation test pieces of each test example, the ultraviolet-visible absorption spectrum was measured using an automatic spectrophotometer (U-4100, manufactured by Hitachi, Ltd.). Then, for wavelengths in the measurement range of 360 nm to 800 nm, the absorption maximum wavelength λmax and the absorbance at that wavelength were determined. In the evaluation of coloring strength, an absorbance of 0.40 or more was rated as good (G), and an absorbance of less than 0.40 was rated as bad (B).

[0422] <Calculation of Transition Dipole Moment> The transition dipole moments of the anthraquinone derivatives of Test Examples 6-1 to 6-13 were calculated using the time-dependent density functional method. Specifically, the quantum chemistry calculation program GAMESS was used, with the functional set to B3LYP and the basis function set to 6-31G(d), to calculate the transition dipole moment of each anthraquinone derivative in vacuum. The transition dipole moment is a vector consisting of x, y, and z components. The value obtained by raising the sum of the squares of each component to the 1 / 2 power was used to determine the magnitude μ (μ = (x ２ +y ２ +z ２ ) １／２ )

[0423] (Evaluation Results) Table 6 shows the evaluation results of the structure of the anthraquinone derivative, each component of the transition dipole moment, the magnitude μ of the transition dipole moment, the maximum absorption wavelength λmax, the absorbance, and the coloring strength for Test Examples 6-1 to 6-13. The structure of the anthraquinone derivative of each Test Example is represented by the following formula (II), and R, A, X, and Y in Table 6 are １ , Y ２ , Z are R, A, X, and Y in the following formula (II). １ , Y ２ , Z.

[0424]

[0425]

[0426] As shown in Table 6, Test Examples 6-1 to 6-10, in which the magnitude μ of the transition dipole moment was 3.30 D or more, exhibited higher absorbance and better tinting strength than Test Examples 6-11 to 6-13, in which the magnitude μ of the transition dipole moment was less than 3.30 D. Furthermore, the anthraquinone derivatives of Test Examples 6-1 to 6-10 also tended to have high absorption maximum wavelengths in the wavelength range of 580 nm or more, and therefore can be used as cyan dyes.

[0427] The results in Table 6 suggest that the direct bonding of a substituent to the β-position increases the transition dipole moment. １ , Y ２It was confirmed that when the group is an electron-donating group such as an alkylamino group, the transition dipole moment becomes large and high absorbance tends to be obtained.

[0428] [Example 7: Test Example Corresponding to Seventh Embodiment] In Example 7, synthesis was carried out using the same precursor as in Examples 1 to 6. (Test Example 7-1) The dye of Test Example 1-11 in Example 1 was replaced with the anthraquinone derivative of Test Example 7-1. The anthraquinone derivative of Test Example 7-1 is a compound represented by the following formula (P7-1).

[0429]

[0430] Test Example 7-2 The dye of Test Example 2-8 of the second embodiment was the anthraquinone derivative of Test Example 7-2, which is a compound represented by the following formula (P7-2).

[0431]

[0432] Test Example 7-3 The dye of Test Example 1-3 in the first embodiment was replaced with an anthraquinone derivative of Test Example 7-3, which is a compound represented by the following formula (P7-3).

[0433]

[0434] Test Example 7-4 The dye of Test Example 1-2 in the first embodiment was replaced with the anthraquinone derivative of Test Example 7-4, which is a compound represented by the following formula (P7-4).

[0435]

[0436] Test Example 7-5 Synthesis of Precursor A4 Precursor A4 was obtained in the same manner as in Example 1, except that 4-cyanoaniline was used instead of 4-heptylaniline in the synthesis of Precursor A2. Precursor A4 is a compound represented by the following formula (7-a).

[0437]

[0438] Synthesis of Dye of Test Example 7-5 The anthraquinone derivative of Test Example 7-5 was obtained by performing the same synthesis as in Test Example 1-1 of Example 1, except that Precursor A2 was changed to Precursor A4 and 4-dimethylaminophenylboronic acid was changed to 4-heptyloxyphenylboronic acid. The anthraquinone derivative of Test Example 7-5 is a compound represented by the following formula (P7-5).

[0439]

[0440] (Test Example 7-6) <Synthesis of Dye of Test Example 7-6> The anthraquinone derivative of Test Example 7-6 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 1-1 of the first embodiment, except that Precursor A2 was changed to Precursor A4 and 4-dimethylaminophenylboronic acid was changed to 4-pentylcyclohexylphenylboronic acid. The anthraquinone derivative of Test Example 7-6 is a compound represented by the following formula (P7-6). Note that the anthraquinone derivative of Test Example 7-6 is the same compound as the anthraquinone derivative of Test Example 2-3.

[0441]

[0442] Test Example 7-7 The dye of Test Example 5-5 in the fifth embodiment was replaced with an anthraquinone derivative of Test Example 7-7, which is a compound represented by the following formula (P7-7).

[0443]

[0444] Test Example 7-8 The dye of Test Example 5-7 in the fifth embodiment was replaced with an anthraquinone derivative of Test Example 7-8, which is a compound represented by the following formula (P7-8).

[0445]

[0446] (Test Example 7-9) <Synthesis of dye of Test Example 7-9> The anthraquinone derivative of Test Example 7-9 was obtained by performing the same synthesis as in Test Example 4-10 of Example 4, except that precursor D1 was changed to precursor D3 and 4-methoxybenzenethiol was changed to 4-heptyloxybenzenethiol in the dye synthesis step. The anthraquinone derivative of Test Example 7-9 is a compound represented by the following formula (P7-9).

[0447]

[0448] (Test Example 7-10) <Synthesis of Dye of Test Example 7-10> The anthraquinone derivative of Test Example 7-10 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 4-13 of the fourth embodiment, except that precursor A2 was changed to precursor A3. The anthraquinone derivative of Test Example 7-10 is a compound represented by the following formula (P7-10). Note that the anthraquinone derivative of Test Example 7-10 is the same compound as the anthraquinone derivative of Test Example 1-12.

[0449]

[0450] Test Example 7-11 The dye of Test Example 6-11 of Example 6 was an anthraquinone derivative of Test Example 7-11, which is a compound represented by the following formula (P7-11).

[0451]

[0452] Test Example 7-12 The dye of Test Example 6-12 of Example 6 was an anthraquinone derivative of Test Example 7-12, which is a compound represented by the following formula (P7-12).

[0453]

[0454] Test Example 7-13 Synthesis of Precursor D5 Precursor D5 was obtained in the same manner as in Example 4, except that in the synthesis step of Precursor B11, Precursor B4 was changed to Precursor A1 and 4-heptyloxyphenol was changed to 4-pentylcyclohexylphenol. Precursor D5 is a compound represented by the following formula (7-b).

[0455]

[0456] Synthesis of Dye of Test Example 7-13 The anthraquinone derivative of Test Example 7-13 was obtained by performing the same synthesis as in Test Example 4-10 of the fourth embodiment, except that precursor D1 was changed to precursor D5 and 4-methoxybenzenethiol was changed to 4-heptyloxybenzenethiol. The anthraquinone derivative of Test Example 7-13 is a compound represented by the following formula (P7-13).

[0457]

[0458] (Evaluation Method) <Evaluation of Absorption Wavelength and Tinting Strength> For the anthraquinone derivatives of Test Examples 7-1 to 7-13, evaluation specimens were prepared in the same manner as in Example 1. Then, in the same manner as in Example 6, the absorption maximum wavelength λmax and the absorbance at that wavelength were determined, and the tinting strength was evaluated.

[0459] <Calculation of molecular orbital coefficients> For the anthraquinone derivatives of Test Examples 7-1 to 7-13, molecular orbital coefficients were calculated using density functional theory. Specifically, using the quantum chemistry calculation program GAMESS, the anthraquinone derivatives were subjected to structural optimization using the B3LYP functional and the 6-31G(d) basis function, and the molecular orbital coefficients for the optimized structure were obtained. C in the above formula (7-1) １１ , C １２ , C ２１ , C ２２ For each carbon atom, the square root of the sum of the squares of the coefficients corresponding to the orbitals on the carbon atom, M １１ , M １２ , M ２１ , M ２２ Calculate 、 M １１ , M １２ , M ２１ , M ２２ Under these calculation conditions, 15 orbitals are assigned to the carbon atom, and molecular orbital coefficients are calculated for each orbital.

[0460] (Evaluation Results) Table 7 shows the evaluation results of the structure of the anthraquinone derivative, the square root of the sum of the squares of the molecular orbital coefficients, the average Mv, the maximum absorption wavelength λmax, the absorbance, and the coloring strength for Test Examples 7-1 to 7-13. The structure of the anthraquinone derivative of each Test Example is represented by the following formula (II), and R, A, X, and Y in Table 7 are １ , Y ２ , Z are R, A, X, and Y in the following formula (II). １ , Y ２ , Z.

[0461]

[0462]

[0463] As shown in Table 7, Test Examples 7-1 to 7-9, which had an average Mv of 0.03 or more, exhibited higher absorbance and better tinting strength than Test Examples 7-10 to 7-13, which had an average Mv of less than 0.03. Furthermore, the anthraquinone derivatives of Test Examples 7-1 to 7-9 have absorption maxima in the wavelength range of 580 nm or more, and are therefore usable as cyan dyes.

[0464] The results in Table 7 suggest that the average Mv increases when a substituent is directly bonded to the β-position. Furthermore, a comparison between Test Example 7-1 and Test Example 7-5, and a comparison between Test Example 7-2 and Test Example 7-6 confirmed that when Z is an electron-withdrawing group such as a cyano group, the average Mv increases and a high absorbance tends to be obtained. Furthermore, Test Examples 7-3, 7-4, and 7-9 indicate that when Y １ , Y ２ It was confirmed that when is an electron donating group such as an alkylamino group, the average Mv tends to be large and high absorbance tends to be obtained.

[0465] [Example 8: Test Example Corresponding to Eighth Embodiment] In Example 8, synthesis was carried out using the same precursor as in Examples 1 to 7. (Test Example 8-1) The dye of Test Example 4-1 in Example 4 was replaced with the anthraquinone derivative of Test Example 8-1. The anthraquinone derivative of Test Example 8-1 is a compound represented by the following formula (P8-1).

[0466]

[0467] Test Example 8-2 Synthesis of Precursor B15 Precursor B15 was obtained in the same manner as in Example 4, except that 4-heptylphenol was used instead of 4-heptyloxyphenol in the synthesis of Precursor B11. Precursor B15 is a compound represented by the following formula (8-a).

[0468]

[0469] <Synthesis of Precursor B16> Precursor B16 was obtained in the same manner as in the synthesis of precursor B12 in Example 4, except that precursor B11 was replaced with precursor B15. Precursor B16 is a compound represented by the following formula (8-b).

[0470]

[0471] Synthesis of Dye of Test Example 8-2 The anthraquinone derivative of Test Example 8-2 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 1-14 of Example 1, except that precursor B6 was changed to precursor B16. The anthraquinone derivative of Test Example 8-2 is a compound represented by the following formula (P8-2).

[0472]

[0473] Test Example 8-3 Synthesis of Precursor B17 Precursor B17 was obtained in the same manner as in Example 4, except that 4-heptylaniline was replaced with N,N-dimethyl-1,4-phenylenediamine. Precursor B17 is a compound represented by the following formula (8-c).

[0474]

[0475] Synthesis of Dye of Test Example 8-3 The anthraquinone derivative of Test Example 8-3 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 1-14 of Example 1, except that precursor B6 was changed to precursor B17. The anthraquinone derivative of Test Example 8-3 is a compound represented by the following formula (P8-3).

[0476]

[0477] Test Example 8-4 Synthesis of Precursor B18 Precursor B18 was obtained in the same manner as in Example 4, except that 4-aminobenzonitrile was used instead of 4-heptylaniline in the synthesis of Precursor B12. Precursor B18 is a compound represented by the following formula (8-d).

[0478]

[0479] Synthesis of Dye of Test Example 8-4 The anthraquinone derivative of Test Example 8-4 was obtained by performing synthesis in the same manner as in the synthesis step of the dye of Test Example 1-14 of Example 1, except that precursor B6 was changed to precursor B18. The anthraquinone derivative of Test Example 8-4 is a compound represented by the following formula (P8-4).

[0480]

[0481] Test Example 8-5 The dye of Test Example 1-15 in the first embodiment was the anthraquinone derivative of Test Example 8-5, which is a compound represented by the following formula (P8-5).

[0482]

[0483] Test Example 8-6 The dye of Test Example 3-12 of the third embodiment was the anthraquinone derivative of Test Example 8-6, which is a compound represented by the following formula (P8-6).

[0484]

[0485] Test Example 8-7 The dye of Test Example 1-14 in the first embodiment was the anthraquinone derivative of Test Example 8-7. The anthraquinone derivative of Test Example 8-7 is a compound represented by the following formula (P8-7).

[0486]

[0487] (Test Example 8-8) <Synthesis of Precursor B19> Precursor B4 (0.20 parts by weight), 4-heptyloxyaniline (1.2 parts by weight), and copper powder (0.053 parts by weight) were placed in a two-necked flask and purged with nitrogen. N-methyl-2-pyrrolidone (3.0 parts by weight) was added thereto and stirred at 180°C for 10 hours. This reaction solution was extracted with pure water / dichloromethane, and the resulting organic layer was dried over sodium sulfate, filtered, and then concentrated using an evaporator. Precursor B19 was then obtained by purification using silica gel column chromatography (developing solvent: hexane / ethyl acetate = 8 / 1). Precursor B19 is a compound represented by the following formula (8-e):

[0488]

[0489] <Synthesis of Precursor B20> Precursor B20 was obtained by the same synthesis as in Example 4 for precursor B12, except that precursor B11 was replaced with precursor B19. Precursor B20 is a compound represented by the following formula (8-f).

[0490]

[0491] Synthesis of Dye of Test Example 8-8 The anthraquinone derivative of Test Example 8-8 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 1-14 of Example 1, except that precursor B6 was changed to precursor B20. The anthraquinone derivative of Test Example 8-8 is a compound represented by the following formula (P8-8).

[0492]

[0493] Test Example 8-9 The dye of Test Example 4-13 in the fourth embodiment was the anthraquinone derivative of Test Example 8-9, which is a compound represented by the following formula (P8-9).

[0494]

[0495] Test Example 8-10 The dye of Test Example 2-8 in the second embodiment was replaced with the anthraquinone derivative of Test Example 8-10, which is a compound represented by the following formula (P8-10).

[0496]

[0497] (Test Example 8-11) <Synthesis of dye of Test Example 8-11> The anthraquinone derivative of Test Example 8-11 was obtained by performing synthesis in the same manner as in Test Example 1-1 of Example 1, except that 4-dimethylaminophenylboronic acid was changed to (4-piperidyl-1-yl)phenylboronic acid. The anthraquinone derivative of Test Example 8-11 is a compound represented by the following formula (P8-11).

[0498]

[0499] (Test Example 8-12) <Synthesis of dye of Test Example 8-12> The anthraquinone derivative of Test Example 8-12 was obtained by performing synthesis in the same manner as in the synthesis step of Precursor B19, except that Precursor B4 was changed to Precursor A2. The anthraquinone derivative of Test Example 8-12 is a compound represented by the following formula (P8-12).

[0500]

[0501] (Evaluation Method) For the anthraquinone derivatives of Test Examples 8-1 to 8-12, evaluation specimens were prepared in the same manner as in Example 1, and the maximum absorption wavelength λmax was determined. Similarly to Example 1, a light resistance test was conducted on the evaluation specimens, and the absorbance change rate ΔAbs between before and after the light resistance test was calculated. In the evaluation of light resistance, a ΔAbs of 2% or less was rated as good (G), and a ΔAbs of more than 2% was rated as bad (B).

[0502] (Evaluation Results) Table 8 shows the structure of the anthraquinone derivative, the absorption maximum wavelength λmax, the rate of change in absorbance ΔAbs, and the evaluation results of light resistance for Test Examples 8-1 to 8-12. The structure of the anthraquinone derivative of each Test Example is represented by the following formula (I), and R, A, Y in Table 8 １ , Y ２ , Z are R, A, Y in the following formula (I). １ , Y ２ , Z.

[0503]

[0504]

[0505] As shown in Table 8, the anthraquinone derivatives of Test Examples 8-1 to 8-8 have absorption maxima in the wavelength range of 600 nm or more. Therefore, the anthraquinone derivatives of Test Examples 8-1 to 8-8 exhibit blue color and can be used as cyan dyes. Furthermore, Test Examples 8-1 to 8-8 exhibit high lightfastness.

[0506] The anthraquinone derivatives of Test Examples 8-9 to 8-12 have a hydroxyl group at the α-position. Test Examples 8-9 and 8-12, in which the β-position is an ether bond or a secondary amine, have an absorbance change rate ΔAbs of 25% or more, and have extremely low lightfastness. Test Examples 8-10 and 8-11, in which a substituted phenyl group is directly bonded to the β-position, have significantly improved lightfastness compared to Test Examples 8-9 and 8-12.

[0507] Furthermore, Test Examples 8-1 to 8-8, which do not have a hydroxyl group at the α-position, exhibited even higher light resistance than Test Examples 8-10 and 8-11, regardless of whether the β-position is a direct bond. This suggests that the anthraquinone derivatives of Test Examples 8-1 to 8-8 exhibit high light resistance due to the structure in which the substituents at the α-position are an amino group and an anilino group.

[0508] [Example 9: Test Example Corresponding to the Ninth Embodiment] In Example 9, synthesis was carried out using the same precursor as in Examples 1 to 8. <Synthesis of Precursor D6> Precursor D6 was obtained by carrying out the same synthesis as in Example 4, except that in the synthesis step of precursor D1, 4-pentylcyclohexylphenylboronic acid was changed to 4-heptyloxyphenylboronic acid and precursor A1 was changed to precursor B4. Precursor D6 is a compound represented by the following formula (9-a). Note that precursor D6 is the same compound as precursor B7.

[0509]

[0510] <Synthesis of Precursor D7> Precursor D7 was obtained in the same manner as in the synthesis of Precursor D1 in Test Example 4, except that 4-pentylcyclohexylphenylboronic acid was replaced with 4-(dimethylamino)phenylboronic acid. Precursor D7 is a compound represented by the following formula (9-b).

[0511]

[0512] <Synthesis of Precursor D8> In the synthesis step of Precursor D1 in the Fourth Test Example, instead of adding 1.2 parts by weight of 4-pentylcyclohexylphenylboronic acid, 0.7 parts by weight of 4-pentylcyclohexylphenylboronic acid was added and the reaction solution was stirred for 1 hour, and then 0.5 parts by weight of 4-monobutylaminophenylboronic acid was added and the mixture was heated and stirred at 80°C for 2 hours or more. Thereafter, extraction and purification were carried out in the same manner as in the synthesis step of Precursor D1, to obtain Precursor D8. Precursor D8 is a compound represented by the following formula (9-c):

[0513]

[0514] (Test Example 9-1) <Synthesis of dye of Test Example 9-1> The anthraquinone derivative of Test Example 9-1 was obtained by performing the same synthesis as in Test Example 4-10 of Example 4, except that precursor D1 was changed to precursor D2 and 4-methoxybenzenethiol was changed to 4-heptylbenzenethiol in the dye synthesis step. The anthraquinone derivative of Test Example 9-1 is a compound represented by the following formula (P9-1).

[0515]

[0516] Test Example 9-2 The dye of Test Example 5-5 of the fifth embodiment was the anthraquinone derivative of Test Example 9-2, which is a compound represented by the following formula (P9-2).

[0517]

[0518] Test Example 9-3 The dye of Test Example 4-11 in the fourth embodiment was the anthraquinone derivative of Test Example 9-3, which is a compound represented by the following formula (P9-3).

[0519]

[0520] Test Example 9-4 The dye of Test Example 5-8 of the fifth embodiment was replaced with the anthraquinone derivative of Test Example 9-4, which is a compound represented by the following formula (P9-4).

[0521]

[0522] (Test Example 9-5) <Synthesis of dye of Test Example 9-5> The anthraquinone derivative of Test Example 9-5 was obtained by performing the same synthesis as in Test Example 4-10 of Example 4, except that precursor D1 was changed to precursor D6 and 4-methoxybenzenethiol was changed to 4-heptylbenzenethiol in the dye synthesis step. The anthraquinone derivative of Test Example 9-5 is a compound represented by the following formula (P9-5).

[0523]

[0524] Test Example 9-6 The dye of Test Example 5-7 of the fifth embodiment was replaced with the anthraquinone derivative of Test Example 9-6, which is a compound represented by the following formula (P9-6).

[0525]

[0526] (Test Example 9-7) <Synthesis of dye of Test Example 9-7> The anthraquinone derivative of Test Example 9-7 was obtained by performing the same synthesis as in Test Example 4-10 of Example 4, except that precursor D1 was changed to precursor D7 and 4-methoxybenzenethiol was changed to 4-heptyloxybenzenethiol in the dye synthesis process. The anthraquinone derivative of Test Example 9-7 is a compound represented by the following formula (P9-7).

[0527]

[0528] (Test Example 9-8) <Synthesis of dye of Test Example 9-8> The anthraquinone derivative of Test Example 9-8 was obtained by performing the same synthesis as in Test Example 4-10 of Example 4, except that precursor D1 was changed to precursor D7 and 4-methoxybenzenethiol was changed to 4-cyanobenzenethiol. The anthraquinone derivative of Test Example 9-8 is a compound represented by the following formula (P9-8).

[0529]

[0530] Test Example 9-9 The dye of Test Example 7-9 of the seventh embodiment was an anthraquinone derivative of Test Example 9-9, which is a compound represented by the following formula (P9-9).

[0531]

[0532] (Test Examples 9-10) <Synthesis of Dye of Test Example 9-10> The anthraquinone derivative of Test Example 9-10 was obtained by performing synthesis in the same manner as in the dye synthesis step of Test Example 4-10 of Example 4, except that precursor D1 was changed to precursor D8 and 4-methoxybenzenethiol was changed to 4-heptyloxybenzenethiol. The anthraquinone derivative of Test Example 9-10 is a compound represented by the following formula (P9-10).

[0533]

[0534] (Test Example 9-11) <Synthesis of dye of Test Example 9-11> The anthraquinone derivative of Test Example 9-11 was obtained by performing synthesis in the same manner as in Test Example 1-1 of Example 1, except that 4-dimethylaminophenylboronic acid was changed to 4-heptyloxyphenylboronic acid. The anthraquinone derivative of Test Example 9-11 is a compound represented by the following formula (P9-11).

[0535]

[0536] Test Example 9-12 The dye of Test Example 6-12 of Example 6 was the anthraquinone derivative of Test Example 9-12, which is a compound represented by the following formula (P9-12).

[0537]

[0538] (Evaluation Method) For the anthraquinone derivatives of Test Examples 9-1 to 9-12, evaluation specimens were prepared in the same manner as in Example 1, and the maximum absorption wavelength λmax was determined.

[0539] In the evaluation of the absorption wavelength, when the absorption maximum wavelength λmax was 580 nm or more and 670 nm or less, the blueness was rated as "G" (Good), and when the absorption maximum wavelength λmax was less than 580 nm or more than 670 nm, the blueness was rated as "B" (Bad). In addition, as in the first example, a light resistance test was performed on the evaluation specimen to evaluate the light resistance.

[0540] (Evaluation Results) Table 9 shows the structure of the anthraquinone derivative, the absorption maximum wavelength λmax, the evaluation results of the absorption wavelength, the rate of change in absorbance ΔAbs, and the evaluation results of light resistance for Test Examples 9-1 to 9-10. The structure of the anthraquinone derivative of each Test Example is represented by the following formula (III), and R and Y in Table 9 are １ , Y ２ , Z are R and Y in the following formula (III). １ , Y ２ , Z.

[0541]

[0542]

[0543] Table 10 shows the structure of the anthraquinone derivative, the absorption maximum wavelength λmax, the evaluation results of the absorption wavelength, the rate of change in absorbance ΔAbs, and the evaluation results of light resistance for Test Examples 9-11 and 9-12. The structure of the anthraquinone derivative of each Test Example is represented by the following formula (II), and R, A, X, and Y in Table 10 are １ , Y ２ , Z are R, A, X, and Y in the following formula (II). １ , Y ２ , Z.

[0544]

[0545]

[0546] As shown in Tables 9 and 10, Test Examples 9-1 to 9-11, in which a substituted phenyl group is directly bonded to the β-position of the anthraquinone skeleton, exhibit good lightfastness, whereas Test Example 9-12, in which an ether bond is formed at the β-position, exhibits extremely poor lightfastness. Therefore, it was confirmed that the lightfastness is improved due to the structure in which a substituted phenyl group is directly bonded to the β-position.

[0547] In addition, Test Examples 9-1 to 9-10, which have a substituted phenyl group directly bonded to the β-position and a substituted phenylthio group at the α-position, exhibit a maximum absorption wavelength λmax in the range of 580 nm to 670 nm. On the other hand, Test Example 9-11, which has a substituted phenyl group directly bonded to the β-position and a substituted anilino group at the α-position, exhibits a maximum absorption wavelength λmax exceeding 680 nm, and Test Example 9-12, which has an ether bond at the β-position and a substituted phenylthio group at the α-position, exhibits a maximum absorption wavelength λmax of 570 nm or less.

[0548] Therefore, it was confirmed that by having both a direct bond structure of a substituted phenyl group at the β-position, which makes a large contribution to the long wavelength shift of the absorption maximum wavelength λmax, and a substituted phenylthio group at the α-position, which makes a small contribution to the long wavelength shift, the absorption maximum wavelength λmax can be obtained in a suitable range, and both lightfastness and blueness can be achieved.

Claims

1. An anthraquinone derivative represented by the following formula (9-1). In formula (9-1), R １ and R ２ are each independently an amino group or a hydroxyl group, and Y １ , Y ２ , and Z are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cyano group, a nitro group, a halogen atom, a halogenated alkyl group having 1 to 10 carbon atoms, an amino group, an alkylamino group, a piperidyl group, an aryl group, or a cyclohexyl group, and the aryl group and the cyclohexyl group may have substituents.

2. The anthraquinone derivative according to claim 1, which is represented by the following formula (9-2). In formula (9-2), Y １ , Y ２ , and Z are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cyano group, a nitro group, a halogen atom, a halogenated alkyl group having 1 to 10 carbon atoms, an amino group, an alkylamino group, a piperidyl group, an aryl group, or a cyclohexyl group, and the aryl group and the cyclohexyl group may have substituents.

3. An anthraquinone derivative represented by the following formula (1-1). In formula (1-1), R １ , R ２ , and R ３ are each independently an amino group or a hydroxyl group, and at least one of R １ , R ２ , and R ３ is a hydroxyl group. At least one of Y １ and Y ２ is an electron-donating group, and the electron-donating group is an alkylamino group, an amino group, or a piperidyl group. When only one of Y １ and Y ２ is an electron-donating group, the other of Y １ and Y ２ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group, or a cyclohexyl group, and the aryl group and the cyclohexyl group may have substituents. Z is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cyano group, a nitro group, a halogen atom, an amino group, or an alkylamino group.

4. An anthraquinone derivative represented by the following formula (1-1). In formula (1-1), R １ , R ２ , and R ３ are each independently an amino group or a hydroxyl group. At least one of Y １ and Y ２ is an electron-donating group, and the electron-donating group is an acetamide group or a hydroxyl group. When only one of Y １ and Y ２ is an electron-donating group, the other of Y １ and Y ２ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group, or a cyclohexyl group, and the aryl group and the cyclohexyl group may have substituents. Z is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cyano group, a nitro group, a halogen atom, an amino group, or an alkylamino group.

5. In the formula (1-1), R １ and R ３ are each a hydroxyl group, and R ２ is an amino group. The anthraquinone derivative according to claim 3 or 4.

6. An anthraquinone derivative represented by the following formula (2-1). In formula (2-1), R １ , R ２ , and R ３ are each independently an amino group or a hydroxyl group, and at least one of R １ , R ２ , and R ３ is a hydroxyl group. Y １ and Y ２ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group, a cyano group, a nitro group, a halogen atom, an amino group, an alkylamino group, or a cyclohexyl group, and the aryl group and the cyclohexyl group may have substituents. Z is an electron-withdrawing group, and the electron-withdrawing group is a cyano group or a halogenated alkyl group.

7. An anthraquinone derivative represented by the following formula (2-1). In formula (2-1), R １ , R ２ , and R ３ are each independently an amino group or a hydroxyl group. Y １ and Y ２ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group, a cyano group, a nitro group, a halogen atom, an amino group, an alkylamino group, or a cyclohexyl group, and the aryl group and the cyclohexyl group may have substituents. Z is an electron-withdrawing group, and the electron-withdrawing group is an aldehyde group, an acetyl group, or a sulfo group.

8. In the formula (2-1), R １ and R ３ are each a hydroxyl group, and R ２ is an amino group. The anthraquinone derivative according to claim 6 or 7.

9. The anthraquinone derivative according to claim 8, which is represented by the following formula (2-3). In formula (2-3), R ４ and R ５ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a cyclic hydrocarbon group, and Z is the electron-withdrawing group.

10. An anthraquinone derivative represented by the following formula (3-1). In formula (3-1), R １ , R ２ , and R ３ are each independently an amino group or a hydroxyl group, and at least one of R １ , R ２ , and R ３ is a hydroxyl group. At least one of Y １ and Y ２ is a cyclohexyl group, and the cyclohexyl group may have a substituent. When only one of Y １ and Y ２ is a cyclohexyl group, the other of Y １ and Y ２ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group, a cyano group, a nitro group, a halogen atom, an amino group, or an alkylamino group, and the aryl group may have a substituent. Z is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cyano group, a nitro group, a halogen atom, an amino group, or an alkylamino group.

11. The anthraquinone derivative according to claim 10, which is represented by the following formula (3-2). In formula (3-2), Y １ and Y ２ at least one of which is a cyclohexyl group, and the cyclohexyl group may have a substituent. When only one of Y １ and Y ２ is a cyclohexyl group, the other of Y １ and Y ２ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group, a cyano group, a nitro group, a halogen atom, an amino group, or an alkylamino group, and the aryl group may have a substituent. Z is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cyano group, a nitro group, a halogen atom, an amino group, or an alkylamino group.

12. The anthraquinone derivative according to claim 11, which is represented by the following formula (3-3). In formula (3-3), R ４ and R ５ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a cyclic hydrocarbon group, and Z is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cyano group, a nitro group, a halogen atom, an amino group, or an alkylamino group.

13. An anthraquinone derivative represented by the following formula (8-1). In the formula (8-1), A is a direct bond, an oxygen atom, or -NH-, and Y １ , Y ２ , and Z are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cyano group, a nitro group, a halogen atom, a halogenated alkyl group having 1 to 10 carbon atoms, an amino group, an alkylamino group, an aryl group, a piperidyl group, or a cyclohexyl group, and the aryl group and the cyclohexyl group may have a substituent.

14. The anthraquinone derivative according to claim 13, which is represented by the following formula (8-2). In formula (8-2), Y １ , Y ２ , and Z are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cyano group, a nitro group, a halogen atom, a halogenated alkyl group having 1 to 10 carbon atoms, an amino group, an alkylamino group, an aryl group, a piperidyl group, or a cyclohexyl group, and the aryl group and the cyclohexyl group may have a substituent.

15. The anthraquinone derivative according to claim 13, which is represented by the following formula (8-3). In formula (8-3), Y １ , Y ２ , and Z are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cyano group, a nitro group, a halogen atom, a halogenated alkyl group having 1 to 10 carbon atoms, an amino group, an alkylamino group, an aryl group, a piperidyl group, or a cyclohexyl group, and the aryl group and the cyclohexyl group may have substituents.

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