JP2017088521A - Phenanthroline compound and colorant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a phenanthroline compound having a new skeleton available as a yellow pigment.SOLUTION: The phenanthroline compound is represented by the general formula in the figure. (In the general formula (1), Rand Reach independently represent a hydrogen atom, or an optionally substituted alkyl group, aryl group or indandione group, provided that at least one of Rand Ris the optionally substituted indandione group; and Rand Reach independently represent a hydrogen atom or a phenyl group.)SELECTED DRAWING: None

Description

  The present invention relates to a phenanthroline compound and a colorant using the same.

  Organic pigments have long been used in various paints, printing and writing inks, and colorants for plastics. In recent years, various fields such as recording materials such as ink jet methods, electrodeposition recording methods, and electrophotographic methods, color filters used in various displays such as liquid crystal displays, and organic solar cell materials have been widely used. Organic pigments are used. For this reason, although the required properties differ depending on the application, the properties required for organic pigments include not only the desired hue, but also a variety of properties such as heat resistance, solvent resistance, and light resistance. Is desired.

  On the other hand, examples of the yellow organic pigment include many compounds such as azo pigments such as monoazo, disazo, and condensed azo, and polycyclic pigments such as anthraquinone, isoindoline, and quinophthalone. For example, Patent Document 1 discloses an invention relating to a curable composition containing a compound having a specific quinophthalone skeleton as a colorant for the purpose of providing a composition excellent in light resistance, heat resistance, developability, and the like. Has been. Further, for example, Patent Document 2 discloses an invention relating to a quinophthalone compound having a specific structure, which has been made for the purpose of providing a pigment having excellent color characteristics such as coloring power and hue.

JP 2006-91768 A JP 2013-1810115 A

  Many compounds have been proposed as yellow organic pigments so far, but few compounds that have saturation, coloring power, heat resistance and the like suitable as yellow pigments are not well known. Therefore, creation of a novel compound that can be suitably used as a yellow pigment is desired.

  The present invention intends to provide a phenanthroline compound having a new skeleton usable as a yellow pigment.

（前記一般式（１）中、Ｒ¹及びＲ²は、それぞれ独立に、水素原子、又は置換基を有していてもよい、アルキル基、アリール基若しくはインダンジオン基を表す。ただし、Ｒ¹及びＲ²のうちの少なくとも一方は、置換基を有していてもよいインダンジオン基である。Ｒ³及びＲ⁴は、それぞれ独立に、水素原子又はフェニル基を表す。）
［２］前記一般式（１）中、Ｒ¹及びＲ²のうちの少なくとも一方が、ハロゲノインダンジオン基である前記［１］に記載のフェナントロリン化合物。
［３］前記一般式（１）中、Ｒ¹及びＲ²のうちの少なくとも一方が、テトラハロゲノインダンジオン基である前記［１］又は［２］に記載のフェナントロリン化合物。
［４］前記一般式（１）中、Ｒ¹及びＲ²がともにテトラハロゲノインダンジオン基である前記［１］〜［３］のいずれかに記載のフェナントロリン化合物。
また、本発明によれば、以下の［５］に示す着色剤が提供される。
［５］前記［１］〜［４］のいずれかに記載のフェナントロリン化合物を含有する着色剤。 According to the present invention, the phenanthroline compound shown in the following [1] is provided. This phenanthroline compound may be those shown in the following [2] to [4].
[1] A phenanthroline compound represented by the following general formula (1).

(In the general formula (1), R ¹ and R ² each independently represents a hydrogen atom or an alkyl group, an aryl group or an indandione group, which may have a substituent. However, R ¹ And at least one of R ² and R ² is an optionally substituted indandione group, and R ³ and R ⁴ each independently represents a hydrogen atom or a phenyl group.)
[2] The phenanthroline compound according to the above [1], wherein at least one of R ¹ and R ^{2 in} the general formula (1) is a halogenoindandione group.
[3] The phenanthroline compound according to [1] or [2], wherein at least one of R ¹ and R ^{2 in} the general formula (1) is a tetrahalogenoindanedione group.
[4] The phenanthroline compound according to any one of [1] to [3], wherein both R ¹ and R ^{2 in the} general formula (1) are tetrahalogenoindanedione groups.
Moreover, according to this invention, the coloring agent shown to the following [5] is provided.
[5] A colorant containing the phenanthroline compound according to any one of [1] to [4].

  According to the present invention, a phenanthroline compound having a new skeleton usable as a yellow pigment can be provided.

  Embodiments of the present invention will be described below, but the present invention is not limited to the following embodiments.

<Phenanthroline compound>
Phenanthroline is a compound having two nitrogen atoms in the molecule, and has been widely used as a bipyridyl-based ligand in fields such as analytical chemistry and functional complex chemistry. Although the skeleton of phenanthroline is similar to the quinoline ring in 2-methylquinoline (quinaldine) used for the synthesis of quinophthalone compounds, there has never been used as a pigment.

  As a result of intensive research on novel compounds that can be used as yellow pigments, the present inventors have obtained the knowledge that the methyl group introduced at the 2-position of phenanthroline is active, like quinaldine. Pay attention. The inventors have found that a pigment can be formed from the 2-methyl-1,10-phenanthroline, and have completed the present invention.

  That is, the phenanthroline compound according to one embodiment of the present invention is represented by the following general formula (1).

In General Formula (1), R ¹ and R ² each independently represent a hydrogen atom, or an alkyl group, an aryl group, or an indandione group that may have a substituent. However, at least one of R ¹ and R ² is an indandione group which may have a substituent. R ³ and R ⁴ each independently represents a hydrogen atom or a phenyl group.

  Phenanthroline has a pyridine ring condensed as compared with quinoline and can improve heat resistance. In addition, phenanthroline exhibits symmetry between pyridine rings in phenanthroline, and in addition to the effect of simple condensed ring, pigment properties such as coloring power, heat resistance, and light resistance are improved.

Conventionally, as a method for improving quinophthalone-based pigment properties, a method of introducing a hydroxy group or an amino group into a quinoline ring in quinaldine used for the synthesis of a quinophthalone compound has been proposed. When these functional groups are introduced into the quinoline ring in quinaldine, the heat resistance is improved, but CIE L ^* a ^* b ^* standardized by the International Commission on Illumination (CIE) and adopted in JIS Z8781-4: 2013 ^. b ^* values in a color system (b ^* value represents the blue when a negative value, a positive represent tO tHE value yellowish.) becomes too low, a problem that color will dull There was a point.

The phenanthroline compound of the present embodiment has a b ^* value in the L ^* a ^* b ^* color system of about b ^* > 100, and can be sufficiently used as a yellow pigment. In the present specification, the “yellow pigment” includes a yellow pigment, and the “yellow pigment” includes a yellowish color such as orange or yellow green. The value of a ^* in the L ^* a ^* b ^* color system of the phenanthroline compound of the present embodiment (a value of a ^* represents greenness when it is a negative value, and redness when it is a positive value) Is preferably -10.0 <a ^* <30.0. A phenanthroline compound in which b ^* > 100 and a ^* > 0 can be used as a bright reddish yellow pigment. A phenanthroline compound in which b ^* > 100 and a ^* <0 can be used as a bright greenish yellow pigment. The value of brightness L ^* in the L ^* a ^* b ^* color system of the phenanthroline compound of the present embodiment is preferably 50 or more, more preferably 60 or more, and even more preferably 70 or more.

  The phenanthroline compound of this embodiment is excellent in chroma, lightness, coloring power, etc., is useful as a yellow pigment, and can also have good heat resistance and light resistance. Hereinafter, the phenanthroline compound of the present embodiment will be described in more detail with reference to preferable configurations and the like from the viewpoint of utility as a yellow pigment such as pigment characteristics and hue.

In the above general formula (1) representing the structure of the phenanthroline compound of the present embodiment, the alkyl group which may have a substituent represented by R ¹ and R ² may be linear or branched. May be. The alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and still more preferably 1 to 10 carbon atoms. Specific examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, tert- Examples thereof include a pentyl group, a hexyl group, an isohexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a pentadecyl group, and an icosyl group.

Specific examples of the aryl group in the aryl group which may have a substituent represented by R ¹ and R ² include a phenyl group, a methylphenyl group, a xylyl group, a biphenylyl group, and a naphthyl group. Can do.

The alkyl group, aryl group and indandione group represented by R ¹ and R ² may have a substituent. Examples of the substituent that the alkyl group, the aryl group, and the indandione group may have include, for example, a halogen atom, a hydroxy group, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, and an amino group. , And a nitro group. These substituents may be further substituted by the substituents mentioned here.

  Specific examples of the halogen atom as the substituent include fluorine, chlorine, bromine and iodine. Specific examples of the alkyl group and aryl group as the substituent include the same ones as described above.

  Specific examples of the alkoxy group as a substituent include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a pentyloxy group, and a hexyloxy group. Specific examples of the aryloxy group as a substituent include a phenyloxy group, a methylphenyloxy group, a xylyloxy group, a biphenylyloxy group, and a naphthyloxy group.

  Specific examples of the alkylthio group as a substituent include a methylthio group, an ethylthio group, a propylthio group, an isopropylthio group, a butylthio group, an isobutylthio group, a pentylthio group, and a hexylthio group. Specific examples of the arylthio group as a substituent include a phenylthio group, a methylphenylthio group, a xylylthio group, a biphenylylthio group, and a naphthylthio group.

The phenanthroline compound of this embodiment has an indandione group which may have a substituent as at least one of R ¹ and R ^{2 in} the general formula (1). The indandione group which may have a substituent is obtained by condensing 2-methyl-1,10-phenanthroline or a derivative thereof with phthalic anhydride or a derivative thereof as described in the description of the synthesis method described later. Can be introduced. In this case, the indandione group which may have a substituent can be said to be a skeleton group derived from phthalic anhydride or a derivative thereof (1,3-indandione skeleton group).

  The indandione group which may have a substituent is preferably a group represented by the following general formula (2).

In general formula (2), R ^{5 to} R ⁸ each independently represent a hydrogen atom, a halogen atom, a hydroxy group, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an amino group, or Represents a nitro group. These groups (alkyl group, aryl group, alkoxy group, aryloxy group, alkylthio group, arylthio group, amino group, and nitro group) may be substituted by the atoms or groups listed here, as described above. Good. * In General formula (2) represents the coupling | bond part with the aromatic ring in General formula (1).

Specific examples of R ^{5 to} R ^{8 in} the general formula (2) are the same as those given as specific examples of the substituent that the above-mentioned indandione group may have. R ^{5 to} R ⁸ in the general formula (2) are each independently preferably a hydrogen atom, a halogen atom, an alkyl group, or a nitro group, and more preferably a hydrogen atom, a halogen atom, or an alkyl group. Preferably, it is a hydrogen atom or a halogen atom.

When at least one of R ^{5 to} R ^{8 in} the general formula (2) has a halogen atom, the halogen atom is preferably fluorine, chlorine, and bromine, and more preferably chlorine and bromine. When at least one of R ^{5 to} R ^{8 in} the general formula (2) has an alkyl group, the alkyl group may be linear or branched. It is preferable that carbon number of an alkyl group is 1-10, and it is more preferable that it is 1-5. More preferable alkyl groups include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group.

The indandione group represented by the general formula (2) is an indandione group (halogenoindandione group) substituted with a halogen atom, wherein at least one of R ^{5 to} R ⁸ is a halogen atom. preferable. As shown in the general formula (2), the number of halogen atoms that can be substituted on one indanedione group (the number of halogen substitutions) is four at the maximum. In the case where R ¹ and R ² in the general formula (1) are both indandione groups which may have a substituent, the total number of halogen atoms that can be substituted for the indandione group in the phenanthroline compound is 8 at the maximum. It is. In one indandione group, the number of halogen atoms is more preferably 2 or more. Furthermore, a tetrahalogenoindanedione group in which any of R ^{5 to} R ⁸ is a halogen atom is also preferable.

In the phenanthroline compound represented by the general formula (1), at least one of R ¹ and R ^{2 in} the general formula (1) is preferably the above-described halogenoindandione group, and the above-described tetrahalogenoindandione is described above. More preferably, it is a group. Furthermore, a phenanthroline compound in which R ¹ and R ² in the general formula (1) are both tetrahalogenoindanedione groups is also preferable. In the general formula (1), when the indandione group is substituted with a halogen atom, the phenanthroline compound has good solvent resistance and heat resistance as in the case of a general pigment.

When either ^one of R ¹ and R ^{2 in} the general formula (1) is an indandione group which may have a substituent, either one has a hydrogen atom or a substituent. It may preferably be an indandione group or an alkyl group, and more preferably an indandione group or an alkyl group which may have a substituent.

  Preferable specific examples of the phenanthroline compound represented by the general formula (1) of the present embodiment include compounds represented by the following formulas (1-1) to (1-8). Non-halogen (halogen-free) phenanthroline compounds as exemplified by the following formulas (1-1) to (1-8) are advantageous in that they have a low environmental burden and are safe.

  Moreover, as a suitable specific example of a phenanthroline compound having a halogenoindandione group among the phenanthroline compounds represented by the general formula (1) of the present embodiment, the following formulas (1-9) to (1-16) The compound represented by these can be mentioned. A phenanthroline compound having an indandione group substituted with a halogen atom, as exemplified by the following formulas (1-9) to (1-16), is further excellent in coloring power, heat resistance, solvent resistance and the like. It can be more suitably used as a yellow pigment.

  The method for synthesizing the phenanthroline compound of the present embodiment is not particularly limited. For example, 2-methyl-1,10-phenanthroline represented by the following general formula (3) or a derivative thereof is condensed with a phthalic anhydride or a derivative thereof in a solvent (high boiling point solvent) to obtain a general formula (1 The phenanthroline compound represented by this can be synthesized.

In general formula (3), R ³ and R ⁴ each independently represents a hydrogen atom or a phenyl group, and R ⁹ represents a hydrogen atom or an alkyl group or an aryl group which may have a substituent. Represent.

The alkyl group and aryl group which may have a substituent represented by R ⁹ in the general formula (3) each have a substituent described in the description of the general formula (1). The same as the alkyl group and aryl group which may be used.

In the general formula (3), when R ⁹ is a methyl group (that is, when the compound represented by the general formula (3) is 2,9-dimethyl-1,10-phenanthroline or a derivative thereof), the phenanthroline ring Any of the methyl groups at the 2-position and 9-position can be condensed with phthalic anhydride or a derivative thereof to obtain a phenanthroline compound having two indandione groups in one molecule.

  In addition, 2-methyl-1,10-phenanthroline represented by the general formula (3) or a derivative thereof may be a salt such as hydrochloride or a hydrate.

  Specific examples of phthalic anhydride or derivatives thereof include, for example, phthalic anhydride, 3-methylphthalic anhydride, 4-methylphthalic anhydride, 4-tert-butylphthalic anhydride, 4-chlorophthalic anhydride, 4 , 5-dichlorophthalic anhydride, tetrachlorophthalic anhydride, 4-bromophthalic anhydride, tetrabromophthalic anhydride, 3-fluorophthalic anhydride, 4-fluorophthalic anhydride, 4,5- Examples include difluorophthalic anhydride, tetrafluorophthalic anhydride, 4-carboxyphthalic anhydride, 3-nitrophthalic anhydride, and 4-nitrophthalic anhydride.

  Specific examples of the high boiling point solvent include aromatic hydrocarbons such as chlorobenzene, dichlorobenzene, nitrobenzene, and chloronaphthalene, and benzoic acid derivatives such as benzoic acid and methyl benzoate.

  When synthesizing the phenanthroline compound represented by the general formula (1), 2-methyl-1,10-phenanthroline represented by the general formula (3) or a derivative thereof, phthalic anhydride or a derivative thereof, and high One or two or more boiling solvents can be used.

As temperature at the time of synthesize | combining the phenanthroline compound represented by General formula (1), 120 to 250 degreeC is preferable. A compound in which R ¹ and R ² in the general formula (1) are both indandione groups which may have a substituent (that is, 2 indandione groups which may have a substituent in one molecule) The temperature is preferably 180 ° C. or higher, and more preferably 180 ° C. to 240 ° C. A compound in which either ^one of R ¹ and R ^{2 in} the general formula (1) is an indandione group which may have a substituent (that is, may have a substituent in one molecule) In order to obtain a phenanthroline compound having one indandione group, the temperature is preferably 180 ° C. or lower, more preferably 120 ° C. to 170 ° C.

  The structure and molecular weight of the phenanthroline compound of the present embodiment depend on the results of mass spectrometry, nuclear magnetic resonance spectroscopy (NMR), infrared spectroscopy (IR), elemental analysis, etc. by MALDI (Matrix Assisted Laser Desorption / Ionization). Can be confirmed.

  Since the phenanthroline compound of the present embodiment described above has a structure represented by the general formula (1), it is excellent in saturation, brightness, and coloring power, and suitable as a colorant in a wide range of fields described later as a yellow pigment. Can be used. The phenanthroline compound of this embodiment can be more suitably used as a colorant for paints, a colorant for color filters, a colorant for image recording, and the like. Moreover, in this embodiment, since it has the structure represented by the general formula (1), it is possible to obtain a phenanthroline compound having good heat resistance, and further to obtain a phenanthroline compound having good light resistance. Is also possible.

<Colorant>
The colorant which concerns on one Embodiment of this invention contains the phenanthroline compound represented by the said General formula (1) mentioned above. In the colorant, one of phenanthroline compounds represented by the general formula (1) may be contained alone, or two or more thereof may be contained.

  The colorant of the present embodiment can be used in a wide range of fields as a colorant for image display, image recording, printing ink, writing ink, plastic, pigment printing, and paint. The colorant of this embodiment is suitable for a paint or a color filter for image display. The colorant of this embodiment is also useful as a material for an image recording agent such as an ink for ink jet recording, an electrodeposition recording liquid, and a developer for electrophotography. These materials for the image recording agent are used for image recording methods such as an ink jet recording method, an electrodeposition recording method, and an electrophotographic method. If the colorant of this embodiment is used, a material for an image recording agent that can provide a high-quality image can be prepared by any image recording method.

  Although the colorant of this embodiment may consist only of the above-mentioned phenanthroline compound, it is preferable to further contain a film-forming material as a component other than the phenanthroline compound. The film forming material is a material that can form a film on an adherend to be colored with a colorant. When the colorant contains a film forming material, the content of the phenanthroline compound in the colorant is preferably 5 to 500 parts by mass, and 50 to 250 parts by mass with respect to 100 parts by mass of the film forming material. It is more preferable. The colorant containing a film-forming material can be prepared, for example, by mixing a phenanthroline compound and a film-forming material such as a resin (polymer and copolymer), oligomer, or monomer.

  Moreover, the colorant of this embodiment can also be adjusted by mixing a phenanthroline compound and a liquid containing a film-forming material. Examples of the liquid medium used for the liquid containing the film-forming material include an organic solvent, water, and a mixed liquid of an organic solvent and water. As the liquid containing the film-forming material, a liquid containing a photosensitive film-forming material or a liquid containing a non-photosensitive film-forming material can be used.

  Specific examples of the liquid containing a photosensitive film-forming material include liquids containing a photosensitive film-forming material used for ultraviolet curable inks and electron beam curable inks. Specific examples of the liquid containing the non-photosensitive film-forming material include varnishes used for printing inks such as letterpress inks, lithographic inks, gravure inks, and screen inks; varnishes used for room temperature drying or baking paints; Examples thereof include varnishes used for electrodeposition coating; varnishes used for thermal transfer ribbons.

  Specific examples of photosensitive film forming materials include photosensitive cyclized rubber resins, photosensitive phenol resins, photosensitive polyacrylate resins, photosensitive polyamide resins, photosensitive polyimide resins, and unsaturated polyester resins. And photosensitive resins such as polyester acrylate resins, polyether acrylate resins, and polyol acrylate resins. The liquid containing these photosensitive resins may contain various monomers as reactive diluents.

  If a photopolymerization initiator such as benzoin ether and benzophenone is added to a colorant containing a photosensitive resin as a film-forming material and kneaded by a conventionally known method, a photocurable photosensitive pigment dispersion is obtained. be able to. Further, if a thermal polymerization initiator is used instead of the photopolymerization initiator, a thermosetting pigment dispersion can be obtained.

  As the non-photosensitive film-forming material, a room-temperature drying type resin or a baking type resin can be used. Specific examples of non-photosensitive film-forming materials include styrene- (meth) acrylic acid ester copolymers, polyamide resins, polyimide resins, polyamideimide resins, polyesterimide resins, water-soluble aminopolyester resins. , And water-soluble salts thereof, as well as water-soluble salts of alkyd resins, melamine resins, styrene-maleic acid ester copolymers, and (meth) acrylic acid ester- (meth) acrylic acid copolymers. Salt.

  The colorant of this embodiment may contain pigments other than the above-described phenanthroline compound, and depending on the application, etc., a dispersant, a dispersion aid, a smoothing agent, a plasticizer, a surface activity. Conventionally known additives such as an agent, an antifoaming agent, and a thickener may be contained. As for other pigments and additives, one kind may be used alone, or two or more kinds may be used in combination.

  Next, the phenanthroline compound according to the above-described embodiment will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In the following text, “part” is based on mass unless otherwise specified.

[Synthesis of phenanthroline compounds]
<Example 1>
To 100 parts of benzoic acid, 5 parts of 2,9-dimethyl-1,10-phenanthroline (hereinafter referred to as neocuproine) hydrochloride monohydrate and 7 parts of phthalic anhydride were added and heated at 160 ° C. for 4 hours. Next, 50 parts of methanol was added before the benzoic acid solidified, and the mixture was stirred for 30 minutes. The obtained reaction mixture was filtered after cooling, and the filtrate was washed with methanol and water. The filtered residue after washing was dried at 80 ° C. to obtain 4 parts of a phenanthroline compound (A) represented by the following formula (A).

<Example 2>
To 100 parts of benzoic acid, 5 parts of neocuproine hydrochloride monohydrate and 13 parts of tetrachlorophthalic anhydride were added and heated at 160 ° C. for 4 hours. Next, 50 parts of methanol was added before the benzoic acid solidified and stirred for 30 minutes. The obtained reaction mixture was poured into 1000 parts of water, and the pH was adjusted to 11 to 12 with sodium hydroxide, followed by stirring at 60 ° C. for 1 hour. The reaction mixture thus obtained was filtered after cooling, and the residue was washed with methanol and water. The filtrate after washing was dried at 80 ° C. to obtain 9 parts of a phenanthroline compound (B) represented by the following formula (B).

<Example 3>
In the same manner as in Example 2 except that 21 parts of tetrabromophthalic anhydride was used instead of 13 parts of tetrachlorophthalic anhydride used in Example 2 above, it was represented by the following formula (C). 12 parts of a phenanthroline compound (C) was obtained.

<Example 4>
The heating temperature and heating time (160 ° C. and 4 hours) in Example 2 described above are represented by the above formula (B) in the same manner as in Example 2 except that heating is performed at 230 ° C. for 4 hours. 10 parts of a mixture of the phenanthroline compound (B) and the phenanthroline compound (D) represented by the following formula (D) were obtained.

When each phenanthroline compound obtained in Examples 1 to 4 was subjected to mass spectrometry by MALDI, peaks corresponding to the following molecular weights were detected. From the raw materials used and the results of mass spectrometry, it was confirmed that a compound (pigment) having the target composition was obtained.
Phenanthroline compound (A): molecular weight 338
Phenanthroline compound (B): molecular weight 476
Phenanthroline compound (C): molecular weight 654
Phenanthroline compound (D): molecular weight 744

[Synthesis of quinophthalone compounds]
<Comparative Example 1>
A quinophthalone represented by the following formula (E) was obtained in the same manner as in Example 2 except that 3 parts of quinaldine was used instead of 5 parts of neocuproine hydrochloride monohydrate used in Example 2 above. 8 parts of compound (E) were obtained.

<Comparative example 2>
In the same manner as in Example 2 except that 3 parts of 8-hydroxyquinaldine was used instead of 5 parts of neocuproine hydrochloride monohydrate used in Example 2 above, the following formula (F) 8 parts of the quinophthalone compound (F) represented was obtained.

[Evaluation]
Next, the suitability of the phenanthroline compounds obtained in Examples 1 to 4 and the quinophthalone compounds obtained in Comparative Examples 1 and 2 were evaluated. Specifically, the heat resistance of each compound, and the hue, saturation, brightness, and coloring power of a coating film formed using a paint containing each compound as a pigment were evaluated.

<Paint test>
(Preparation of dark paint)
The phenanthroline compounds obtained in Examples 1 to 4 and the quinophthalone compounds obtained in Comparative Examples 1 and 2 were each used alone as a pigment. And each component shown below is mixed for 90 minutes by the paint conditioner with the compounding quantity shown below, a pigment is disperse | distributed, and each concentration of Examples 1-4 and Comparative Examples 1 and 2 about each pigment (each compound). A color paint was prepared.
・ Pigment 1.5 parts ・ Butylated melamine resin (* 1) 8.5 parts ・ Short oil alkyd resin of coconut oil (* 2) 17.0 parts ・ Xylene / 1-butanol (2/1 mass ratio) mixed solvent 5.0 parts (* 1) Trade name “Super Becamine J-820” (nonvolatile content: 58 to 62% by mass, manufactured by Dainippon Ink & Chemicals, Inc.)
(* 2) Product name “Phthalkid 133-60” (nonvolatile content: 55-65% by mass, manufactured by Hitachi Chemical Co., Ltd.)

(1) Evaluation of Hue, Saturation, and Lightness Using an applicator (3 mil), each of the dark paints of Examples 1 to 4 and Comparative Examples 1 and 2 was developed on art paper and 140 ° C. for 30 minutes. I baked it. About each formed coating film, L ^* , a ^* , b ^* was measured using the colorimeter (The product name "Karacom system" by Dainichi Seika Kogyo Co., Ltd.). The results are shown in Table 1. Further, the saturation and brightness were evaluated according to the following criteria. The results are shown in Table 2. The saturation C ^* was calculated from C ^* = ((a ^* ) ² + (b ^* ) ² ) ^1/2 .
(Saturation evaluation criteria)
○: Saturation was relatively excellent (C ^* was 100 or more).
Δ: Saturation was relatively good (C ^* was 80 or more and less than 100).
X: Saturation was relatively low (C ^* was less than 80).
(Lightness evaluation criteria)
○: The brightness was relatively excellent (L ^* was 70 or more).
Δ: Brightness was relatively good (L ^* was 50 or more and less than 70).
X: The brightness was relatively low (L ^* was less than 50).

(2) Evaluation of coloring power Pigment: Titanium white = 1: 20 (mass ratio) with white paint containing titanium white (titanium oxide) (manufactured by Nippon Paint Co., Ltd., trade name “Organeo White N”) The dark paint was diluted and a light paint was prepared for each dark paint. Using an applicator (3 mil), the light color paint was spread on art paper and baked at 140 ° C. for 30 minutes. The formed coating film was observed with the naked eye, and the coloring power was evaluated according to the following criteria by comparing the intensity of yellow coloring. The results are shown in Table 2.
(Evaluation criteria for tinting strength)
○: It was evaluated that the yellow color was relatively strong and the coloring power was excellent.
(Triangle | delta): There was relatively yellow coloring and it evaluated that coloring power was favorable.
X: It was evaluated that relatively little yellow color was confirmed and the coloring power was poor.

<Heat resistance test>
(3) Heat resistance Each of the phenanthroline compounds obtained in Examples 1 to 4 and the quinophthalone compounds obtained in Comparative Examples 1 and 2 was subjected to differential thermogravimetric analysis (TG-DTA), and the following criteria were used. Therefore, the heat resistance was evaluated. The results are shown in Table 2.
○: Good heat resistance (mass loss was less than 5% at 400 ° C.)
Δ: heat resistance (at 400 ° C., mass reduction was 5% or more and less than 10%)
X: No heat resistance (mass reduction was 10% or more at 400 ° C.)

  The hue of the phenanthroline compound obtained in Examples 1 to 3 is yellow, and the hue of the phenanthroline compound (a mixture of (B) and (D)) obtained in Example 4 is orange. It was confirmed that the phenanthroline compound obtained in 1 was excellent in chroma, lightness, and coloring power and useful as a yellow pigment. Moreover, it was confirmed that the phenanthroline compounds obtained in Examples 2 to 4 are further excellent in heat resistance.

  The phenanthroline compound of the present invention includes, for example, printing ink (offset ink, gravure ink, etc.), various paints, plastics, pigment printing agents, electrophotographic dry / wet toner, ink jet recording ink, thermal transfer recording ink, and color filter use. It is useful as a pigment used in resists and ink for writing instruments.

Claims (5)

A phenanthroline compound represented by the following general formula (1).

(In the general formula (1), R ¹ and R ² each independently represents a hydrogen atom or an alkyl group, an aryl group or an indandione group, which may have a substituent. However, R ¹ And at least one of R ² and R ² is an optionally substituted indandione group, and R ³ and R ⁴ each independently represents a hydrogen atom or a phenyl group.) The phenanthroline compound according to claim 1, wherein at least one of R ¹ and R ^{2 in} the general formula (1) is a halogenoindandione group. The phenanthroline compound according to claim 1 or 2, wherein at least one of R ¹ and R ^{2 in} the general formula (1) is a tetrahalogenoindanedione group. The phenanthroline compound according to any one of claims 1 to 3, wherein in the general formula (1), R ¹ and R ² are both tetrahalogenoindanedione groups.   The coloring agent containing the phenanthroline compound of any one of Claims 1-4.