JP2013028698A - Composite pigment, electrophotographic photoreceptor using the same and image-forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite pigment comprising a specific gallium phthalocyanine compound and an azo compound, capable of achieving high image quality and high stability in an electrophotographic type image-forming device.SOLUTION: The gallium phthalocyanine compound expressed by general formula (B) is used. In general formula (B), Y represents an aryl group which may have a substituent; and n is an integer of 1-3.

Description

  The present invention relates to a composite pigment, an electrophotographic photoreceptor using the composite pigment, and an image forming apparatus.

In recent years, the development of information processing system machines using electrophotography has been remarkable, and laser printers and digital copiers that record information by using light by converting information into digital signals have significantly improved print quality and reliability. . Recently, these laser printers and digital copying machines that are rapidly spreading have been rapidly demanded for high speed, high image quality, and high stability.
As an electrophotographic photosensitive member used in an image forming apparatus, an organic photosensitive member (OPC) using an organic photosensitive material is generally widely applied for reasons such as cost, productivity, and low environmental load.
Various charge generating materials have been developed for use in this organic photoreceptor, and pigments having useful photoreceptor characteristics such as azo pigments and phthalocyanine pigments have been found. Examples of the azo pigment include a benzidine bisazo pigment (see Patent Documents 1 and 2), a stilbene bisazo pigment (see Patent Document 3), a diphenylhexatriene bisazo pigment (see Patent Document 4), and a diphenylbutadiene bisazo pigment. (See Patent Document 5).

  As an example of the phthalocyanine pigment, the titanyl phthalocyanine pigment includes A type described in Patent Document 6, Y type described in Patent Document 7, I type described in Patent Document 8, and Patent Document 9. A type described, C type described in Patent Documents 10 and 11, B type described in Patent Document 12, M type described in Patent Document 13, and Patent Document 14 A quasi-amorphous type is mentioned. Specific examples of the metal-free phthalocyanine pigment include X-type metal-free phthalocyanine pigment (Patent Document 15), cage-type metal-free phthalocyanine (Patent Document 16), and the like. Specific examples of the hydroxygallium phthalocyanine pigment are disclosed in Patent Documents 17 and 18. Specific examples of the copper phthalocyanine pigment are disclosed in Patent Documents 19, 20 and 21, etc. Specific examples of the chlorogallium phthalocyanine pigment are disclosed in Patent Documents 22 and 23. Specific examples of the chloroindium phthalocyanine pigment are disclosed in Patent Document 24 and the like.

However, the photoreceptors using these single pigments have a narrow wavelength range, so they are low in sensitivity to light in the long wavelength range emitted by semiconductor lasers, which are the mainstream of writing light for laser printers and copiers. However, there is a problem that the characteristics of the photosensitive member fluctuate depending on the usage environment and usage time, and it is insufficient as a future photosensitive member for high image quality or high-speed copying machines.
In order to solve these problems, various proposals have been made to mix two or more pigments. For example, a mixture of a metal-free phthalocyanine and a fluorenone-based azo pigment (see Patent Documents 25 and 26), a mixture of a phthalocyanine compound and an azo pigment (see Patent Document 27), a mixture of a metal phthalocyanine and a perylene pigment (see Patent Document 28), quinacridone Mixtures of pigments and titanyl phthalocyanine pigments (see Patent Document 29), titanyl phthalocyanine pigments and other phthalocyanine pigments (see Patent Document 30) have been proposed, but those having sufficient performance are still provided. Absent.

One of the reasons is that the pigment mixing method is mainly mechanical means such as milling, cannot be mixed and combined at the molecular level, and has not been able to fully function as an organic photoconductor. Conceivable. In addition, a method using an acid paste is also proposed, but since concentrated sulfuric acid is used, there are problems in production, and there is a concern about decomposition and the application to pigments is limited. In addition, a phthalocyanine pigment whose characteristics greatly differ depending on the crystal type has a problem that when it is mixed with an acid paste, a desired crystal type cannot be obtained, and as a result, sufficient photoreceptor characteristics cannot be obtained. It was.
Therefore, in order to realize an electrophotographic photosensitive member that overcomes the conventional drawbacks, it is strongly desired to develop a better charge generating material.

  An object of the present invention is to solve various problems in the prior art and achieve the following objects. That is, the present invention relates to a composite pigment composed of a specific gallium phthalocyanine compound and an azo compound that can realize high image quality and high stability of an electrophotographic image forming apparatus such as a copying machine or a laser printer, and the composite pigment. An object of the present invention is to provide an electrophotographic photosensitive member and an image forming apparatus that can output high-quality prints without image deterioration over a long period of time in a wide range of temperature and humidity environments and voltage application conditions, which are used as charge generation materials. .

Means for solving the problems are as follows. That is,
<1> A composite pigment comprising a gallium phthalocyanine compound represented by the following general formula (A) and an azo compound.
However, in the general formula (A), X has an alkyl group which may have a substituent, an alkenyl group which may have a substituent, an alkynyl group which may have a substituent, or a substituent. And an aralkyl group which may be substituted, a cycloalkyl group which may have a substituent, an aryl group which may have a substituent, and a hydrogen atom. R ^{1 to} R ¹⁶ each independently represent any of a hydrogen atom, an alkoxy group, an alkylthio group, an alkyl group, a halogen atom, a nitro group, and an aryl group. n is an integer of 1 to 3.
<2> An electrophotographic photoreceptor comprising a support and at least a photosensitive layer on the support, wherein the photosensitive layer contains the composite pigment described in <1>.
<3> An electrophotographic photosensitive member, electrostatic latent image forming means for forming an electrostatic latent image on the electrophotographic photosensitive member, and developing the electrostatic latent image with toner to form a visible image. An image forming apparatus having at least developing means and transfer means for transferring the visible image to a recording medium,
The image forming apparatus is characterized in that the electrophotographic photosensitive member is the electrophotographic photosensitive member according to <2>.

  According to the present invention, the above-mentioned problems can be solved and the above-described object can be achieved, and the image quality of an electrophotographic image forming apparatus such as a copying machine or a laser printer can be improved. A composite pigment composed of a gallium phthalocyanine compound and an azo compound, and a high-quality print without image deterioration can be output over a long period of time in a wide range of temperature and humidity environments and voltage application conditions using the composite pigment as a charge generation material. An electrophotographic photosensitive member and an image forming apparatus can be provided.

FIG. 1 is a view showing an example of the layer structure of the electrophotographic photosensitive member of the present invention. FIG. 2 is a view showing another example of the layer structure of the electrophotographic photosensitive member of the present invention. FIG. 3 is a view showing still another example of the layer structure of the electrophotographic photosensitive member of the present invention. FIG. 4 is a view showing an example of the layer structure of another electrophotographic photosensitive member of the present invention. FIG. 5 is a diagram for explaining an example of the image forming apparatus of the present invention. FIG. 6 is a view for explaining another example of the image forming apparatus of the present invention. FIG. 7 is a view for explaining another example of the image forming apparatus of the present invention. FIG. 8 is a diagram for explaining an example of a process cartridge.

(Composite pigment)
The composite pigment of the present invention comprises a gallium phthalocyanine compound represented by the following general formula (A) and an azo compound.

<Gallium phthalocyanine compound>
However, in the general formula (A), X has an alkyl group which may have a substituent, an alkenyl group which may have a substituent, an alkynyl group which may have a substituent, or a substituent. And an aralkyl group which may be substituted, a cycloalkyl group which may have a substituent, an aryl group which may have a substituent, and a hydrogen atom. R ^{1 to} R ¹⁶ each independently represent any of a hydrogen atom, an alkoxy group, an alkylthio group, an alkyl group, a halogen atom, a nitro group, and an aryl group. n is an integer of 1 to 3.

In the general formula (A), examples of the alkyl group and the alkyl moiety of the alkoxyl group in X and R ^{1 to} R ¹⁶ include a linear or branched alkyl group having 1 to 20 carbon atoms. Are methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, 1-methylbutyl, 2-methylbutyl, tert-pentyl. Group, hexyl group, heptyl group, 1-isopropyl-2-methylpropyl group, octyl group, nonyl group, decyl group, eicosyl group and the like. Among these, a C1-C10 alkyl group is especially preferable.

Examples of the alkenyl group include linear or branched alkenyl groups having 2 to 20 carbon atoms, and specifically, vinyl group, allyl group, isopropenyl group, butenyl group, isobutenyl group, pentenyl group, 1 -Methyl-2-butenyl group, 1-ethyl-2-propenyl group, octenyl group, nonenyl group, decenyl group, eicosenyl group and the like can be mentioned.
Examples of the aralkyl group include an aralkyl group having 7 to 15 carbon atoms, and specific examples include a benzyl group, a phenethyl group, a phenylpropyl group, and a naphthylmethyl group.
Examples of the alkynyl group include ethynyl group, butynyl group, pentynyl group, hexynyl group, heptynyl group, octynyl group, noninyl group, and the like.

As an aryl group, a C6-C14 aryl group is mentioned, for example, A phenyl group, a tolyl group, a xylyl group, a naphthyl group, a phenanthryl group, an anthryl group, an azulenyl group etc. are mentioned specifically ,.
The cycloalkyl group is, for example, a monovalent group obtained by removing one hydrogen atom from an arbitrary ring carbon atom of a cycloalkane having 3 to 8 carbon atoms. As a specific example of the cycloalkane having 3 to 8 carbon atoms, For example, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane and the like can be mentioned.
As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom are mentioned, for example.
Examples of the alkylthio group include a methylthio group, an ethylthio group, a propylthio group, a butylthio group, a pentylthio group, a hexylthio group, a heptylthio group, an octylthio group, and a nonylthio group.

  Examples of the substituent for X include an alkoxy group, an alkylthio group, an alkyl group, a halogen atom, a nitro group, an amino group, an aryl group, a carboxy group, or a cyano group. The alkyl group and the alkyl part of the alkoxyl group, the alkyl group, The aryl group and halogen atom are the same as described above.

As the gallium phthalocyanine compound, a compound represented by the following general formula (B) is preferable in that it exhibits good electrophotographic photoreceptor characteristics.
However, in said general formula (B), Y represents the aryl group which may have a substituent, and the said substituent is an alkoxy group, an alkylthio group, an alkyl group, a halogen atom, a nitro group, an amino group, an aryl. Represents any of a group, a carboxy group, and a cyano group. n is an integer of 1 to 3.
Examples of the aryl group, alkyl group, alkoxy group, alkylthio group, and halogen atom in the general formula (B) are the same as those in the general formula (A).

Examples of the gallium phthalocyanine compound include compounds represented by any of the following structural formulas (C) to (Q). These may be used individually by 1 type and may use 2 or more types together. Among these, the compounds represented by the following structural formulas (C) and (E) to (G) are particularly preferable in that they exhibit good electrophotographic photoreceptor characteristics.

The gallium phthalocyanine compound represented by the general formula (A) can be synthesized by reacting either a halogenated gallium phthalocyanine or a hydroxygallium phthalocyanine with a carboxylic acid compound in an organic solvent.
Examples of the halogenated gallium phthalocyanine include chlorogallium phthalocyanine, bromogallium phthalocyanine, iodine gallium phthalocyanine, and the like, which can be synthesized by a known method. For example, chlorogallium phthalocyanine C. Acad. Sci. , (1965), 242, 1026, and the method of reacting gallium trichloride with diiminoisoindoline.
The bromogallium phthalocyanine can be synthesized by a method of reacting gallium tribromide and phthalonitrile described in JP-A-59-133551.
The iodine gallium phthalocyanine can be synthesized by a method of reacting gallium triiodide and phthalonitrile described in JP-A-60-59354.
Moreover, the said hydroxygallium phthalocyanine can be obtained by hydrolyzing the above-mentioned gallium halide phthalocyanine. Hydrolysis may be acid hydrolysis or alkaline hydrolysis. Regarding the acid hydrolysis, see, for example, Bull. Soc. Chim. There is a method of hydrolyzing chlorogallium phthalocyanine described in France, 23 (1962) using sulfuric acid. For the alkali hydrolysis, see Inrog. Chem. (19), 3131, and (1980) include a method of decomposing using ammonia.

Next, the gallium phthalocyanine compound represented by the general formula (A) can be synthesized by reacting the obtained gallium halide phthalocyanine or hydroxygallium phthalocyanine with a carboxylic acid compound. Gallium phthalocyanine can be preferably used. As described above, this is due to the production method, and in the production method of hydroxygallium phthalocyanine, generation of decomposition products is unavoidable when acid hydrolysis treatment using an acid or alkali is performed.
In contrast, halogenated gallium phthalocyanine can be produced without a hydrolysis step, so there is no degradation product as a raw material for synthesis, and gallium halide phthalocyanine with few production steps is good. Can be used.

  The carboxylic acid compound is not particularly limited and can be used as long as it is a compound containing a carboxyl group in the molecular structure, such as a generally known organic fatty acid, high acid value resin or copolymer. 4-dimethylaminobenzoic acid, 4-chlorobenzoic acid, pentafluorobenzoic acid, tetrafluorobenzoic acid, cyclohexanecarboxylic acid, cyclopentylacetic acid, cyclopentanecarboxylic acid, cyclohexylacetic acid, cyclopentylmalo Nick acid, cyclohexene-1,2-dicarboxylic acid, 3-cyclohexene-1-carboxyl acid, 1,4-cyclohexanedicarboxyl acid, 1,2- Chlohexanedicarboxylic acid, 3-trifluoromethyl benzoic acid, 3,5-bistrifluoromethyl benzoic acid, 4-methyl benzoic acid, 3-methyl benzoic acid, 4-methoxy benzoic acid, 4- Nitrobenzoic acid, 4-cyanobenzoic acid, picolinic acid, nicotinic acid, isonicotinic acid, 2,3-pyridinedicarboxylic acid, nonadecafluorodecanoic acid, hexadecafluorosebasic acid, Hexafluoroglutaric acid, chlorodifluoroacetic acid, trichloroacetic acid, tribromoacetic acid, trifluoroacetic acid, diph Oroacetic acid, fluoroacetic acid, dichloroacetic acid, acrylic acid, methacrylic acid, pivalic acid, nonafluorovaleric acid, n-valeric acid, pentafluoropropionic acid, heptafluorobutyric acid, Undecafluorohexanoic acid, tert-butylacetic acid, 2,2-dimethylbutyric acid, tridecafluoroheptanoic acid, pentadecafluorooctanoic acid, heptadecafluorononanoic acid, 1,2 , 3-propanetricarboxylic acid, trimesic acid, 1,9-nonanedicarboxylic acid, adipic acid, azelaic acid, dodecanedioi Acid, eicosan geoic acid, glutaric acid, heptadecane acid, hexadecane acid, malonic acid, nonadecane acid, octadecane acid, pentadecane acid, pimelic acid, sebasic acid , Suberic Acid, Scenic Acid, Tetradecandioic Acid, Tridecandioic Acid, or their anhydrides, acid halides, and the like. These may be used individually by 1 type and may use 2 or more types together. Among these, 3-trifluoromethyl benzoic acid, pentafluorobenzoic acid, 4-dimethylaminobenzoic acid, and 4-chlorobenzoic acid are particularly preferable.

The quantitative ratio of the halogenated gallium phthalocyanine or hydroxygallium phthalocyanine to the carboxylic acid compound is as follows. When n in the general formula (A) is 2, The carboxylic acid compound is preferably about 1/3 mole. When n in the general formula (A) is 1, the carboxylic acid compound is preferably equimolar or more, and 1.1-500 mol is suitable although it depends on the reactivity of the carboxylic acid compound used. .
Further, when the carboxylic acid compound is liquid at the reaction temperature, it may be used as a reaction solvent.

Examples of the organic solvent used here include dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, tetrahydrofuran, dioxane, 2-butanone, cyclohexanone, monochlorobenzene, dichlorobenzene, toluene, xylene, anisole, Examples thereof include nitrobenzene, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethyl acetate, butyl acetate, dichloroethane, trichloroethane, pyridine, picoline, and quinoline. These may be used individually by 1 type and may use 2 or more types together.
The reaction can be carried out by reacting at a reaction temperature of 0 ° C. to 200 ° C., preferably 20 ° C. to 150 ° C. for 30 minutes to 50 hours.

<Azo compound>
Azo compound A (H) n used in the composite pigment of the present invention (where A is a residue of an azo compound having the same meaning as the following general formula (I), H is a hydrogen atom, and n is 1 to 10) Is produced by decarboesterifying an azo compound represented by the following general formula (I) by a chemical method and / or a thermal method.
A (E) n ... General formula (I)
However, in the said general formula (I), A is a residue of an azo compound, this residue A couple | bonds with n E group with an at least 1 hetero atom, and this hetero atom is N and O. Each of which is a part of the residue A, and each E group is independently —C (═O) —O—R ¹⁷ (wherein R ¹⁷ has 4 to 10 carbon atoms) Represents a substituted or unsubstituted alkyl group, alkenyl group, alkynyl group, cycloalkyl group, cycloalkenyl group, or aralkyl group). n is an integer of 1-10.

As the azo compound represented by the general formula (I), those described in JP-A-2009-7523 can be used, and this is decarboesterified by a chemical method and / or a thermal method. And A (H) n (where A is a residue of an azo compound as defined in formula (I), H is a hydrogen atom, and n is an integer of 1 to 10). An azo compound can be produced.
As a chemical method for performing decarboesterification, there is a method of reacting a catalyst such as an acid or a base, and an acid can be preferably used. Examples of the acid include acetic acid, trifluoroacetic acid, propionic acid, acrylic acid, benzoic acid, hydrochloric acid, sulfuric acid, boric acid, p-toluenesulfonic acid, salicylic acid and the like.

As a thermal method for carrying out the decarboesterification, there is a method of heating to 50 ° C. to 300 ° C. in a solvent, and preferably heating conditions of 70 ° C. to 250 ° C. can be used. The heating time is preferably 30 minutes to 20 hours.
Examples of the organic solvent used here include ether solvents such as tetrahydrofuran or dioxane; glycol ether solvents such as ethylene glycol methyl ether and ethylene glycol ethyl ether; butanol, N, N-dimethylformamide, N, N-dimethyl. Examples include acetamide, ethyl cellosolve, ethyl acetate, butyl acetate, monochlorobenzene, dichlorobenzene, toluene, xylene, anisole, cyclohexanone, nitrobenzene, pyridine, picoline, or quinoline. These may be used individually by 1 type and may use 2 or more types together.

Residue A of the azo compound used in the present invention is represented by the following general formula (2).
However, in the said General formula (2), B shows the main frame | skeleton of an azo compound, Cp is a coupler component residue, m represents the integer of 2 or 3.
More preferably, Cp in the general formula (2) is a coupler component residue represented by at least one of the following general formulas (3) to (11).

In the general formulas (3) to (6), X, Y ¹ , Z, p, and q each represent the following.
X represents —OH, —N (R ¹ ) (R ² ), or NHSO ₂ —R ³ (where R ¹ and R ² represent a hydrogen atom or a substituted or unsubstituted alkyl group, and R ³ represents a substituted group). Or an unsubstituted alkyl group or a substituted or unsubstituted aryl group.
Y ¹ represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxy group, a sulfone group, a substituted or unsubstituted sulfamoyl group, or CON (R ⁴ ) (Y ² ) [ Where R ⁴ represents a hydrogen atom, an alkyl group or a substituted product thereof, or a phenyl group or a substituted product thereof, and Y ² represents a hydrocarbon ring group or a substituted product thereof, a heterocyclic group or a substituted product thereof, or N═C (R ⁵ ) (R ⁶ ) (where R ⁵ is a hydrocarbon ring group or a substituted product thereof, a heterocyclic group or a substituted product thereof or a styryl group or a substituted product thereof, and R ⁶ is a hydrogen atom, an alkyl group or a phenyl group. Represents a group or a substituent thereof, or R ⁵ and R ⁶ may form a ring together with the carbon atom bonded thereto. ].
Z represents a hydrocarbon ring or a substituted product thereof, or a heterocyclic ring or a substituted product thereof.
p represents an integer of 1 or 2.
q represents an integer of 1 or 2.

In the general formula (7), R ⁷ represents a substituted or unsubstituted hydrocarbon group, X is as defined above.

However, in the said General formula (8), A is a divalent group of the aromatic hydrocarbon required in order to form an N containing heterocyclic ring with two N atoms described in General formula (8), or nitrogen It represents a heteroatom-containing divalent group containing an atom in the ring (these rings may be substituted or unsubstituted). X represents the same meaning as described above.

However, in said general formula (9), R < ⁸ > represents an alkyl group, a carbamoyl group, a carboxy group, or its ester, Ar < ¹ > represents a hydrocarbon ring group or its substituent, and X is the same meaning as the above. Represents.

In the general formulas (10) and (11), R ⁹ represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group, and Ar ² represents a hydrocarbon ring group or a substituted product thereof. However, at the same time, R ⁹ is not a hydrogen atom and Ar ² is not a cycloalkyl group or a cycloalkenyl group.

More preferably, B in the general formula (2) is an azo compound represented by the following general formulas (12) to (14). Since these azo compounds generally exhibit n-type characteristics, when combined with a gallium phthalocyanine compound, a pn junction can be formed, which is very effective.
However, in said general formula (12), R < ¹¹ > and R < ¹² > represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxyl group, or its ester independently. .
However, in the general formula (13), R ¹⁹ and R ²⁰ independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxyl group, or an ester thereof. .

However, in the general formula (14), R ¹⁴ , R ¹⁵ , and R ¹⁶ are independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxyl group, or The ester is represented.

  As the azo compound represented by the general formula (I), formulas (12) -1 to (12) -14 in which the main skeleton of the azo compound is the general formula (12), and the main skeleton of the azo compound is the general formula ( 13) are formulas (13) -1 to (13) -5, and there are formulas (14) -1 to (14) -5 in which the main skeleton of the azo compound is general formula (14).

Specific examples of the azo compound represented by the general formula (I) are shown below.
E is a carboester group: —C (═O) —O—R ¹ (where R ¹ is a substituted or unsubstituted alkyl group, alkenyl group, alkynyl group, cycloalkyl group, cyclohexane having 4 to 10 carbon atoms) Represents an alkenyl group or an aralkyl group. In the composite pigment of the present invention, all E are hydrogen atoms.

<Examples of compounds in which the main skeleton of the azo compound is the general formula (12)>

<Examples of compounds in which the main skeleton of the azo compound is the general formula (13)>

<Examples of compounds in which the main skeleton of the azo compound is the general formula (14)>

Examples of the azo compound represented by the general formula (I) having a carboester group include JP 2009-7523 A, EP 648770, EP 648817, and JP 2001-513119 A. For example, in the presence of a base as a catalyst in an aprotic organic solvent, preferably at a temperature of 10 ° C. to 100 ° C., for 30 minutes to 20 hours, It can be synthesized by reacting the azo compound represented by the general formula (I) with the pyrocarbonic acid diester represented by the following general formula (15) at an appropriate molar ratio.
In the general formula (15), R ₁ represents a hydrogen atom, or a substituted or unsubstituted alkyl group.

In each case, the molar ratio depends on the number of E (—CO · O—R ₁ ) introduced. Preferably, the pyrocarbonic acid diester is used in a slight excess.
The pyrocarbonic acid diester can react with, for example, an N atom such as a carbamoyl group or an O atom such as a hydroxy group of the azo compound. For example, an azo compound having a carboester group as in the structural formula (E = CO—O—R ₁ group in the structural formula) shown in the exemplary compound can be obtained. As will be understood from the above, the pyrocarbonic acid diester can react with the coupler component residue Cp (many of which have a hydroxy group at the ortho-position or para-position of the azo group coupling). If B has such a reactive site, it can react. However, these examples are examples with a high degree of carboesterification given for explanation and are not intended to limit the present invention.

Suitable aprotic organic solvents include, for example, ether solvents such as tetrahydrofuran or dioxane, or glycol ether solvents such as ethylene glycol methyl ether and ethylene glycol ethyl ether, or acetonitrile, N, N-dimethylformamide, N, Examples thereof include N-dimethylacetamide, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane, monochlorobenzene, toluene, xylene, nitrobenzene, pyridine, picoline or quinoline. These may be used individually by 1 type and may use 2 or more types together. Among these, pyridine, tetrahydrofuran, N, N-dimethylformamide, and N, N-dimethylacetamide are particularly preferable.
Suitable bases for the catalyst include, for example, alkali metals (for example, sodium, potassium, etc.), alkali metal hydroxides and carbonates, alkali metal amides (for example, sodium amide, potassium amide, etc.), alkali metal hydrides. (Eg, lithium hydride, etc.), organic aliphatic, aromatic or heterocyclic N-bases (eg, diazabicyclooctene, diazabicycloundecene, 4-dimethylaminopyridine, dimethylpyridine, pyridine, triethylamine) Etc.). Among these, organic N-bases are particularly preferable. Examples of the organic N-bases include 4-dimethylaminopyridine, dimethylpyridine, pyridine and the like.
The pyrocarbonic acid diester represented by the general formula (15) can be produced by a generally known method. It is also commercially available. R ₁ is as described above, and is preferably a branched alkyl group from the viewpoint of surprising improvement in solubility.

The composite pigment of the present invention will be further described.
The gallium phthalocyanine compound represented by the general formula (A) and A (H) n (where A is a residue of an azo compound as defined in the general formula (I), H is a hydrogen atom, n is The composite ratio of the azo compound represented by 1) is not particularly limited, and can be arbitrarily selected according to the purpose. When the purpose is to further draw out the characteristics of the gallium phthalocyanine compound, the addition amount of the azo compound represented by A (H) n with respect to 100 parts by mass of the gallium phthalocyanine compound represented by the general formula (A) Is preferably 0.1 part by mass to 300 parts by mass, and more preferably 10 parts by mass to 100 parts by mass. When the amount of the azo compound is less than 0.1 parts by mass, the effect of complexation is not clear, and when it exceeds 300 parts by mass, the characteristics of the gallium phthalocyanine compound may not be sufficiently exhibited.
On the contrary, when the purpose is to further draw out the characteristics of the azo compound, the addition amount of the gallium phthalocyanine compound represented by the general formula (A) is 0.1 mass with respect to 100 mass parts of the azo compound. Parts to 300 parts by mass are preferable, and 10 parts to 100 parts by mass are more preferable. When the gallium phthalocyanine compound is less than 0.1 parts by mass, the effect of complexation is not clear, and when it exceeds 300 parts by mass, the characteristics of the azo compound may not be sufficiently exhibited.

As the organic solvent used in producing the composite pigment, the organic solvent can be used. For example, dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, tetrahydrofuran, dioxane, 2- Examples include butanone, cyclohexanone, monochlorobenzene, dichlorobenzene, toluene, xylene, anisole, nitrobenzene, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethyl cellosolve, ethyl acetate, butyl acetate, trichloroethane, picoline, or quinoline. These may be used individually by 1 type and may use 2 or more types together.
The heating temperature for producing the composite pigment is preferably 0 ° C to 200 ° C, more preferably 20 ° C to 150 ° C, and the heating time is preferably 30 minutes to 20 hours.

  The method for producing the composite pigment of the present invention can be roughly classified into four as shown in the following (1) to (4).

(1) A gallium phthalocyanine compound represented by the general formula (A) is produced by reacting one of halogenated gallium phthalocyanine and hydroxygallium phthalocyanine with a carboxylic acid compound, and at least one of a chemical method and a thermal method. From the azo compound represented by the following general formula (I), A (H) n (where A is the residue of the azo compound as defined in general formula (I), H is a hydrogen atom, and n is It is an integer of 1 to 10. It is preferable to produce an azo compound represented by:
A (E) n ... General formula (I)
However, in the said general formula (I), A is a residue of an azo compound, this residue A couple | bonds with n E group with an at least 1 hetero atom, and this hetero atom is N and O. Each of which is a part of the residue A, and each E group is independently —C (═O) —O—R ¹⁷ (wherein R ¹⁷ has 4 to 10 carbon atoms) Represents a substituted or unsubstituted alkyl group, alkenyl group, alkynyl group, cycloalkyl group, cycloalkenyl group, or aralkyl group). n is an integer of 1-10.
That is, the reaction of the halogenated gallium phthalocyanine or hydroxygallium phthalocyanine and a carboxylic acid compound and the decarboesterification of the azo compound represented by the general formula (I): A (E) n are simultaneously performed. Pigments can be produced.
It is suitable that the carboxylic acid compound also functions as a catalyst for decarboesterification of the azo compound. As the organic solvent used in this reaction, those having good solubility of the azo compound are suitable, for example, dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, monochlorobenzene, dichlorobenzene and the like. Is mentioned.
Specifically, by reacting a halogenated gallium phthalocyanine or hydroxygallium phthalocyanine, a carboxylic acid compound, and an azo compound represented by the general formula (I) together with the organic solvent at 20 ° C. to 150 ° C., the above general Gallium phthalocyanine compound represented by formula (A) and A (H) n (where A is a residue of an azo compound having the same meaning as in general formula (I), H is a hydrogen atom, and n is 1 to 1) It is an integer of 10. The composite pigment of this invention which consists of the azo compound represented by this can be manufactured.

(2) When producing a gallium phthalocyanine compound represented by the general formula (A) by reacting either a halogenated gallium phthalocyanine or a hydroxygallium phthalocyanine with a carboxylic acid compound, A (H) n (however, A is a residue of an azo compound having the same meaning as in general formula (I), H is a hydrogen atom, and n is an integer of 1 to 10). It is preferable to be obtained.
That is, the composite pigment of the present invention can be produced by reacting a halogenated gallium phthalocyanine or hydroxygallium phthalocyanine with a carboxylic acid compound in the presence of an azo compound represented by A (H) n.
The azo compound used here can be subjected to mechanical pulverization treatment such as ball milling in advance in order to efficiently combine with the gallium phthalocyanine compound represented by the general formula (A). The organic solvent can be used as a solvent for this reaction.
Specifically, a gallium phthalocyanine compound represented by the general formula (A) by reacting a halogenated gallium phthalocyanine or hydroxygallium phthalocyanine with a carboxylic acid compound and an azo compound together with the organic solvent at 20 ° C. to 150 ° C. An azo compound represented by A (H) n (wherein A is a residue of an azo compound as defined in formula (I), H is a hydrogen atom, and n is an integer of 1 to 10). The composite pigment of this invention which consists of can be manufactured.

(3) From an azo compound represented by the following general formula (I) by A (H) n (where A is an azo compound having the same meaning as in general formula (I)) by at least one of a chemical method and a thermal method. The gallium phthalocyanine compound represented by the general formula (A) is present when the azo compound represented by formula (A) is present. Preferably it is.
A (E) n ... General formula (I)
However, in the said general formula (I), A is a residue of an azo compound, this residue A couple | bonds with n E group with an at least 1 hetero atom, and this hetero atom is N and O. Each of which is a part of the residue A, and each E group is independently —C (═O) —O—R ¹⁷ (wherein R ¹⁷ has 4 to 10 carbon atoms) Represents a substituted or unsubstituted alkyl group, alkenyl group, alkynyl group, cycloalkyl group, cycloalkenyl group, or aralkyl group). n is an integer of 1-10.
That is, in the presence of the gallium phthalocyanine compound represented by the general formula (A), the general formula (I): A (E) n (where A is a residue of an azo compound having the same meaning as the general formula (I)). , H is a hydrogen atom, and n is an integer of 1 to 10. The composite pigment of the present invention can be produced by decarboesterification of an azo compound represented by:
As the solvent used here, an azo compound having good solubility is suitable, and examples thereof include dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, monochlorobenzene, and dichlorobenzene.
When an acid is used as the reaction catalyst, the acid as described above can be used. Specifically, the gallium phthalocyanine compound represented by the general formula (A) and the azo compound represented by the general formula (I): A (E) n and optionally an acid together with the organic solvent described above, By reacting at 150 ° C., the composite pigment of the present invention comprising the gallium phthalocyanine compound represented by the general formula (A) and the azo compound represented by A (H) n can be produced.

(4) Gallium phthalocyanine compound represented by general formula (A) and A (H) n (where A is a residue of an azo compound having the same meaning as in general formula (I), H is a hydrogen atom, n Is an integer of 1 to 10. It is preferable that the azo compound represented by the above is obtained by simultaneous complexation treatment. That is, the composite pigment of the present invention can be produced by simultaneously combining the gallium phthalocyanine compound represented by the general formula (A) and the azo compound represented by A (H) n.
The compounding treatment used here can be selected from conventionally known methods. For example, a gallium phthalocyanine compound represented by the general formula (A) and an azo compound represented by A (H) n can be selected as necessary. Then, the composite pigment of the present invention can be produced by dispersing it in a suitable solvent together with a binder resin using a known dispersion method such as ball mill, attritor, sand mill, or ultrasonic wave.

  The composite pigment of the present invention has excellent characteristics, and is used in, for example, an organic electroluminescence element, an organic solar battery, an electrophotographic photoreceptor in the electrophotographic field, etc. Among these, as described below, It is suitably used as a charge generating material in an electrophotographic photoreceptor.

(Electrophotographic photoreceptor)
The electrophotographic photoreceptor of the present invention comprises a support and at least a photosensitive layer on the support, and further comprises other layers as necessary.
The photosensitive layer contains the composite pigment of the present invention.

Here, the configuration of the electrophotographic photoreceptor will be described in detail below with reference to the drawings.
As shown in FIG. 1, an electrophotographic photosensitive member 201 of the present invention includes a charge generation layer 203 mainly composed of a charge generation material and a charge transport layer 204 mainly composed of a charge transport material on a support 202. It has a stacked configuration.
In the electrophotographic photosensitive member 201 of the present invention, an undercoat layer 206 or an intermediate layer may be formed between the support 202 and the charge generation layer 203 as shown in FIG.
In the electrophotographic photoreceptor 201 of the present invention, a protective layer 205 may be formed on the charge transport layer 204 as shown in FIG.
Further, as shown in FIG. 4, the electrophotographic photosensitive member 201 of the present invention is an embodiment of a single layer type photosensitive member having a single layer type photosensitive layer 207 containing a charge generating substance and a charge transporting substance on a support 202. May be made.

<Support>
Examples of the support include those having a volume resistivity of 10 ¹⁰ Ω · cm or less, for example, metals such as aluminum, nickel, chromium, nichrome, copper, gold, silver, platinum, tin oxide, indium oxide, etc. Of metal oxides by film deposition or sputtering, coated with film or cylindrical plastic, paper, or a plate of aluminum, aluminum alloy, nickel, stainless steel, etc. After the conversion, a tube subjected to surface treatment such as cutting, superfinishing or polishing can be used. An endless nickel belt or an endless stainless steel belt can also be used as a support.

In addition, those obtained by dispersing and coating conductive powder in an appropriate binder resin on the support can also be used as the conductive support.
Examples of the conductive powder include carbon black and acetylene black; metal powder such as aluminum, nickel, iron, nichrome, copper, zinc and silver; metal oxide powder such as conductive tin oxide and ITO. It is done.
Examples of the binder resin include polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, and polyacetic acid. Vinyl, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate, ethyl cellulose, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin , Phenol resin, alkyd resin and the like.
The conductive layer can be provided by dispersing and applying the conductive powder and the binder resin in a suitable solvent such as tetrahydrofuran, dichloromethane, methyl ethyl ketone, toluene and the like.
In addition, heat shrinkage in which the conductive powder is contained in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, polytetrafluoroethylene fluororesin on a suitable cylindrical substrate. What provided the electroconductive layer with the tube can be used suitably as the said support body.

<Photosensitive layer>
Next, the laminated photosensitive layer will be described.
The photosensitive layer having the laminated structure is constituted by sequentially laminating at least a charge generation layer and a charge transport layer.

<< Charge generation layer >>
The charge generation layer contains at least a charge generation material and further contains other components as necessary.
The composite pigment of the present invention is used as the charge generation material.
The charge generation material may be a mixture of the composite pigment of the present invention and a conventionally known charge generation material. Examples of conventionally known charge generating materials include azo pigments such as monoazo pigments, disazo pigments, asymmetrical disazo pigments, trisazo pigments, phthalocyanine pigments such as titanyl phthalocyanine, copper phthalocyanine, vanadyl phthalocyanine, hydroxygallium phthalocyanine, and metal-free phthalocyanine, Examples include perylene pigments, perinone pigments, indigo pigments, pyrrolopyrrole pigments, anthraquinone pigments, quinacridone pigments, quinone condensed polycyclic compounds, and squalium pigments. These may be used individually by 1 type and may use 2 or more types together.

Examples of the binder resin used in the charge generation layer include polyamide resin, polyurethane resin, epoxy resin, polyketone resin, polycarbonate resin, silicone resin, acrylic resin, polyvinyl butyral resin, polyvinyl formal resin, polyvinyl ketone resin, polystyrene resin, Polysulfone resin, poly-N-vinyl carbazole resin, polyacrylamide resin, polyvinyl benzal resin, polyester resin, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide resin, polyamide resin, polyvinyl pyridine resin, Examples include polyvinyl alcohol resin, polyvinyl pyrrolidone resin, cellulose resin, and casein. These may be used individually by 1 type and may use 2 or more types together.
The content of the binder resin is preferably 0 to 500 parts by mass, and more preferably 10 to 300 parts by mass with respect to 100 parts by mass of the charge generation material.

The charge generation layer disperses the charge generation material in a suitable solvent together with a binder resin, if necessary, using a known dispersion method such as a ball mill, an attritor, a sand mill, or an ultrasonic wave. Or it forms by apply | coating on an undercoat layer or an intermediate | middle layer, and drying. The binder resin may be added before or after the charge generating material is dispersed.
Examples of the solvent used for forming the charge generation layer include isopropanol, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane, monochlorobenzene, cyclohexane, toluene, xylene. And generally used organic solvents such as ligroin. These may be used individually by 1 type and may use 2 or more types together. Among these, ketone solvents, ester solvents, and ether solvents are particularly preferable.

The coating solution for forming the charge generation layer is mainly composed of the charge generation material, a solvent and a binder resin, and includes any sensitizer, dispersant, surfactant, silicone oil, etc. An agent may be included.
As a method for coating the charge generation layer using the coating liquid, for example, a known method such as dip coating, spray coating, bead coating, nozzle coating, spinner coating, ring coating, or the like can be used.
The thickness of the charge generation layer is preferably 0.01 μm to 5 μm, and more preferably 0.1 μm to 2 μm. After coating, it is heated and dried in an oven or the like. The drying temperature of the charge generation layer is preferably 50 ° C. or higher and 160 ° C. or lower.

<< Charge transport layer >>
The charge transport layer is formed by applying and drying a coating solution in which a charge transport material and a binder resin are dissolved or dispersed in a solvent. You may add additives, such as a plasticizer, a leveling agent, antioxidant, and a lubricant, to the coating liquid of the said charge transport layer as needed.

Examples of the charge transport material include a hole transport material and an electron transport material.
Examples of the hole transport material include poly-N-vinylcarbazole or a derivative thereof, poly-γ-carbazolylethyl glutamate or a derivative thereof, pyrene-formaldehyde condensate or a derivative thereof, polyvinylpyrene, polyvinylphenanthrene, polysilane, Oxazole derivatives, oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triarylmethane derivatives, 9-styrylanthracene Derivatives, pyrazoline derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, bisstilbene derivatives, enamine derivatives Etc. These may be used individually by 1 type and may use 2 or more types together.

Examples of the electron transporting material include chloroanil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2 , 4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7 -Trinitrodibenzothiophene-5,5-dioxide, benzoquinone derivatives and the like. These may be used individually by 1 type and may use 2 or more types together.
20 mass parts-300 mass parts are preferable with respect to 100 mass parts of said binder resins, and, as for content of the said charge transport material, 40 mass parts-150 mass parts are more preferable.

  Examples of the binder resin include polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, and polyacetic acid. Vinyl, polyvinylidene chloride, polyarylate, phenoxy resin, polycarbonate, cellulose acetate, ethyl cellulose, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly (N-vinylcarbazole), acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin , Phenol resin, alkyd resin and the like. These may be used individually by 1 type and may use 2 or more types together.

Examples of the solvent include tetrahydrofuran, dioxane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, methyl ethyl ketone, and acetone. Among these, the use of a non-halogen solvent is preferable for the purpose of reducing the environmental load. Specifically, cyclic ethers such as tetrahydrofuran, dioxolane and dioxane; aromatic hydrocarbons such as toluene and xylene, or derivatives thereof are preferably used. These may be used individually by 1 type and may use 2 or more types together.
The thickness of the charge transport layer is preferably 10 μm to 50 μm, more preferably 15 μm to 35 μm, from the viewpoint of resolution and responsiveness.
As a coating method, known methods such as a dip coating method, a spray coating method, a bead coating method, a nozzle coating method, a spinner coating method, and a ring coating method can be used, but the charge transport layer has a certain thickness. Since it is necessary to apply thickly, it is preferable to apply the dip coating method with a highly viscous liquid.
The charge transport layer after coating is heated and dried by a thermal means used in the charge generation layer. Although drying temperature changes also with the solvent contained in a coating liquid, 80 to 200 degreeC is preferable and 110 to 170 degreeC is more preferable. The drying time is preferably 10 minutes or more, and more preferably 20 minutes or more.

<Single layer type photosensitive layer>
The single-layer type photosensitive layer is a photoreceptor in which a charge generation function and a charge transport function are dispersed or dissolved in a binder resin to realize a charge generation function and a charge transport function in one layer.
The composite pigment of the present invention is used as the charge generation material.

The photosensitive layer is obtained by dissolving or dispersing a charge generating substance, a charge transporting substance, and a binder resin in a solvent such as tetrahydrofuran, dioxane, dichloroethane, methyl ethyl ketone, cyclohexane, cyclohexanone, toluene, xylene, and dip coating or spray coating. It can be formed by coating using a conventionally known method such as bead coating or ring coating.
The charge transport material preferably contains both the hole transport material and the electron transport material described above. Moreover, a plasticizer, a leveling agent, antioxidant, etc. can also be added as needed.
For the charge generation material, charge transport material, binder resin, organic solvent and various additives used for the single-layer type photosensitive layer, any material contained in the charge generation layer and the charge transport layer is used. It is possible.
As the binder resin, in addition to the binder resin mentioned in the charge transport layer, the binder resin mentioned in the charge generation layer may be mixed and used. The content of the charge generation material with respect to 100 parts by mass of the binder resin is preferably 5 parts by mass to 40 parts by mass, and more preferably 10 parts by mass to 30 parts by mass. Moreover, 0 mass part-190 mass parts are preferable, and, as for content of the said charge transport material, 50 mass parts-150 mass parts are more preferable. The thickness of the photosensitive layer is preferably 5 μm to 40 μm, more preferably 10 μm to 30 μm.

<< undercoat layer >>
In the photoreceptor of the present invention, an undercoat layer can be provided between the support and the photosensitive layer.
The undercoat layer generally comprises a resin as a main component. However, the resin has a solvent resistance to a general organic solvent in consideration of applying a photosensitive layer on the undercoat layer using a solvent. A high resin is preferable. Examples of the resin include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate; alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon; polyurethane, melamine resin, phenol resin, alkyd-melamine resin, isocyanate And curable resins that form a three-dimensional network structure, such as epoxy resins.
To the undercoat layer, a fine powder pigment of a metal oxide such as titanium oxide, silica, alumina, zirconium oxide, tin oxide, or indium oxide may be added in order to prevent moire and reduce residual potential.
The undercoat layer can be formed using a solvent and a coating method in the same manner as the charge generation layer and the charge transport layer.
A silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can be added to the undercoat layer as necessary.

<< Protective layer >>
In the present invention, a protective layer can be provided on the outermost surface of the photoreceptor in order to improve wear resistance. Examples of the protective layer include a polymer charge transport material type obtained by polymerizing a charge transport component and a binder component, a filler dispersion type containing a filler, and a curable type obtained by curing a constituent material having a reactive functional group. However, any conventionally known protective layer can be used.

<< Intermediate layer >>
In the photoreceptor, an intermediate layer may be provided on the support, if necessary. The intermediate layer contains a resin as a main component, and these resins are preferably resins having a high solvent resistance with respect to an organic solvent in consideration of applying a photosensitive layer thereon with a solvent. As the resin, the same resin as the undercoat layer can be appropriately selected and used.

  In the electrophotographic photosensitive member, in order to improve environmental resistance, in particular, in order to prevent a decrease in sensitivity and an increase in residual potential, each layer such as a charge generation layer, a charge transport layer, an undercoat layer, and a surface protective layer is provided. Antioxidants, plasticizers, lubricants, ultraviolet absorbers, low molecular charge transport materials, leveling agents and the like can be added.

<Process cartridge>
The process cartridge used in the present invention includes an electrophotographic photosensitive member, a developing unit that develops an electrostatic latent image formed on the electrophotographic photosensitive member using toner, and forms a visible image, a charging unit, and a cleaning unit. And at least one means selected from a transfer means and a static elimination means, and is detachable from the image forming apparatus main body.
The electrophotographic photoreceptor is the electrophotographic photoreceptor of the present invention.
The process cartridge includes the electrophotographic photosensitive member of the present invention, and further includes at least one of a charging unit, an exposure unit, a developing unit, a transfer unit, a cleaning unit, and a charge eliminating unit, and is detachable from the image forming apparatus. This is a device (part).

Here, an example of the process cartridge used in the present invention is shown in FIG. 8, but the neutralizing means is not described here.
For example, as shown in FIG. 8, the process cartridge includes an electrophotographic photosensitive member 101, and includes a charging unit 112, a developing unit 114, a transfer unit 118, and a cleaning unit 123, and further includes other units as necessary. Have. In FIG. 8, 113 indicates exposure from the exposure means, and 117 indicates recording paper. As the electrophotographic photosensitive member 101, the same one as the image forming apparatus can be used. Any charging means is used as the charging means 112.

  Next, an image forming process using the process cartridge shown in FIG. 8 will be described. The electrophotographic photosensitive member 101 is exposed to an exposure image on its surface by rotating by the charging means 112 and exposure 113 by the exposure means (not shown) while rotating. An electrostatic latent image corresponding to is formed. The electrostatic latent image is developed with toner by the developing unit 114, and the toner development is transferred to the recording paper 117 by the transfer unit 118 and printed out. Next, the surface of the electrophotographic photosensitive member 101 after the image transfer is cleaned by the cleaning unit 123 and further discharged by the discharging unit (not shown), and the above operation is repeated again.

(Image forming apparatus and image forming method)
The image forming apparatus of the present invention comprises at least an electrophotographic photosensitive member, an electrostatic latent image forming unit, a developing unit, a transfer unit, and a fixing unit, and other components appropriately selected as necessary. Means, for example, static elimination means, cleaning means, recycling means, control means and the like.
The image forming method used in the present invention includes at least an electrostatic latent image forming step, a developing step, a transfer step, and a fixing step, and further, other steps appropriately selected as necessary, for example, a static elimination step, Includes cleaning process, recycling process, control process, etc.

  The image forming method used in the present invention can be preferably implemented by the image forming apparatus of the present invention, the electrostatic latent image forming step can be performed by the electrostatic latent image forming unit, and the developing step can be performed. The developing unit can perform the transfer step, the transfer unit can perform the fixing step, the fixing unit can perform the fixing unit, and the other steps can be performed by the other unit.

<Electrostatic latent image forming step and electrostatic latent image forming means>
The electrostatic latent image forming step is a step of forming an electrostatic latent image on the electrophotographic photosensitive member.
The electrophotographic photosensitive member (sometimes referred to as “electrostatic latent image carrier” or “photosensitive member”) is not particularly limited in terms of material, shape, structure, size, etc. The shape is preferably a drum shape, and examples of the material include inorganic photoreceptors such as amorphous silicon and selenium; and organic photoreceptors such as polysilane and phthalopolymethine. Among these, amorphous silicon or the like is preferable in terms of long life.

  As the amorphous silicon photoreceptor, for example, a support is heated to 50 ° C. to 400 ° C., and a vacuum deposition method, a sputtering method, an ion plating method, a thermal CVD method, a photo CVD method, a plasma CVD method is applied on the support. A photoconductor having a photoconductive layer made of a-Si (hereinafter sometimes referred to as “a-Si-based photoconductor”) can be used by a film forming method such as the above. Among these, a plasma CVD method, that is, a method in which a source gas is decomposed by direct current, high frequency or microwave glow discharge to form an a-Si deposited film on a support is preferable.

The formation of the electrostatic latent image can be performed, for example, by uniformly charging the surface of the electrophotographic photosensitive member and then performing imagewise exposure, and can be performed by the electrostatic latent image forming unit. .
The electrostatic latent image forming means includes at least a charger that uniformly charges the surface of the electrophotographic photosensitive member and an exposure device that exposes the surface of the electrophotographic photosensitive member imagewise.

The charging can be performed, for example, by applying a voltage to the surface of the electrophotographic photosensitive member using the charger.
The charger is not particularly limited and may be appropriately selected depending on the purpose. For example, a known contact charging device including a conductive or semiconductive roller, brush, film, rubber blade, etc. And non-contact chargers using corona discharge such as corotrons and corotrons.

The shape of the charging means may take any form such as a magnetic brush or a fur brush in addition to a roller, and can be selected according to the specifications and form of the image forming apparatus. When using a magnetic brush, the magnetic brush is composed of, for example, various ferrite particles such as Zn-Cu ferrite as a charging means, a non-magnetic conductive sleeve for supporting it, and a magnet roll included therein. . Or, when using a brush, for example, as a material of the fur brush, a fur treated with carbon, copper sulfide, metal or metal oxide is used, and this is wound or attached to a metal or other conductive core. To make a charger.
The charger is not limited to the contact charger as described above. However, since an image forming apparatus in which ozone generated from the charger is reduced is obtained, a contact charger is used. preferable.

The exposure can be performed, for example, by exposing the surface of the electrophotographic photosensitive member imagewise using the exposure device.
The exposure device is not particularly limited as long as the surface of the electrophotographic photosensitive member charged by the charger can be exposed like an image to be formed, and can be appropriately selected according to the purpose. However, various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system can be used.
In the present invention, an optical backside system that performs imagewise exposure from the backside of the electrophotographic photosensitive member may be employed.

<Development process and development means>
The developing step is a step of developing the electrostatic latent image using the toner or developer to form a visible image.
The visible image can be formed, for example, by developing the electrostatic latent image using the toner or the developer, and can be performed by the developing unit.
The developing unit is not particularly limited as long as it can be developed using, for example, the toner or the developer, and can be appropriately selected from known ones. For example, the toner or developer is accommodated. Preferred examples include those having at least a developing unit capable of bringing the toner or developer into contact or non-contact with the electrostatic latent image.

  The developing unit may be a dry developing type, a wet developing type, a single color developing unit, or a multi-color developing unit. For example, a toner having a stirrer for charging the toner or the developer by frictional stirring and a rotatable magnet roller is preferable.

  In the developing device, for example, the toner and the carrier are mixed and agitated, and the toner is charged by friction at that time, and held on the surface of the rotating magnet roller in a raised state to form a magnetic brush. . Since the magnet roller is disposed in the vicinity of the electrophotographic photosensitive member, a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is electrically attracted to the electrophotographic photosensitive member. Move to the surface of the body. As a result, the electrostatic latent image is developed with the toner, and a visible image is formed with the toner on the surface of the electrophotographic photosensitive member.

  The developer accommodated in the developing device is a developer containing the toner, but the developer may be a one-component developer or a two-component developer.

<Transfer process and transfer means>
The transfer step is a step of transferring the visible image onto a recording medium. After the primary transfer of the visible image onto the intermediate transfer member using an intermediate transfer member, the visible image is transferred onto the recording medium. A primary transfer step of forming a composite transfer image by transferring a visible image onto an intermediate transfer body using two or more colors, preferably full color toner as the toner, and a composite transfer image; A mode including a secondary transfer step of transferring the transfer image onto the recording medium is more preferable.
The transfer can be performed, for example, by charging the visible image with the electrophotographic photosensitive member using a transfer charger, and can be performed by the transfer unit. The transfer means includes a primary transfer means for transferring a visible image onto an intermediate transfer member to form a composite transfer image, and a secondary transfer means for transferring the composite transfer image onto a recording medium. Embodiments are preferred.
The intermediate transfer member is not particularly limited and may be appropriately selected from known transfer members according to the purpose. For example, a transfer belt and the like are preferable.

The transfer unit (the primary transfer unit and the secondary transfer unit) includes at least a transfer unit that peels and charges the visible image formed on the electrophotographic photosensitive member toward the recording medium. preferable. There may be one transfer means or two or more transfer means. Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.
The recording medium is typically plain paper, but is not particularly limited as long as it can transfer an unfixed image after development, and can be appropriately selected according to the purpose. PET for OHP A base or the like can also be used.

<Fixing process and fixing means>
The fixing step is a step of fixing the visible image transferred to the recording medium using a fixing unit, and may be performed each time the toner of each color is transferred to the recording medium, or for the toner of each color. You may perform this simultaneously in the state which laminated | stacked this.
The fixing unit is not particularly limited and may be appropriately selected depending on the intended purpose, but a known heating and pressing unit is preferable. Examples of the heating and pressing means include a combination of a heating roller and a pressure roller, a combination of a heating roller, a pressure roller, and an endless belt.
The heating in the heating and pressing means is usually preferably 80 ° C to 200 ° C.
In the present invention, for example, a known optical fixing device may be used together with or in place of the fixing step and the fixing unit depending on the purpose.

<Other processes and other means>
-Static elimination process and static elimination means-
The neutralization step is a step of performing neutralization by applying a neutralization bias to the electrophotographic photosensitive member, and can be suitably performed by a neutralization unit.
The neutralization means is not particularly limited, and may be appropriately selected from known neutralizers as long as it can apply a neutralization bias to the electrophotographic photosensitive member. For example, a neutralization lamp is preferably used. Can be mentioned.

-Cleaning process and cleaning means-
The cleaning step is a step of removing the toner remaining on the electrophotographic photosensitive member, and can be suitably performed by a cleaning unit.
The cleaning means is not particularly limited as long as the toner remaining on the electrophotographic photosensitive member can be removed, and can be appropriately selected from known cleaners. For example, a magnetic brush cleaner, a static cleaner Preferred examples include an electric brush cleaner, a magnetic roller cleaner, a blade cleaner, a brush cleaner, and a web cleaner.

-Recycling process and recycling means-
The recycling step is a step of recycling the toner removed by the cleaning step to the developing unit, and can be suitably performed by the recycling unit.
There is no restriction | limiting in particular as said recycling means, A well-known conveyance means etc. are mentioned.

-Control process and control means-
The control step is a step of controlling each of the steps, and can be suitably performed by a control unit.
The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.

Next, the image forming method and the image forming apparatus of the present invention will be described in detail with reference to the drawings.
FIG. 5 is a schematic diagram for explaining an example of the image forming apparatus of the present invention, and the following examples also belong to the category of the present invention.
As shown in FIG. 5, the photoconductor 1 has a drum shape, but may have a sheet shape or an endless belt shape. As the charging roller 12, the transfer charger 18, and the separation charger 19, in addition to corotron, scorotron, solid state charger (solid state charger), roller-shaped charging means or brush-shaped charging means are used. Are all usable.

As the charging means, a non-contact charging system such as corona charging or a contact charging system using a charging means using a roller or a brush is generally used, and any of them can be used effectively in the present invention. In particular, the charging roller can significantly reduce the amount of ozone generated compared to corotron, scorotron, etc., and is effective in stability and prevention of image quality deterioration when the photoreceptor is used repeatedly.
However, due to the contact between the photoconductor and the charging roller, the charging roller is contaminated by repeated use, which affects the photoconductor and contributes to the occurrence of abnormal images and reduced wear resistance. It was. In particular, when a photoconductor having high wear resistance is used, it is difficult to perform reface due to surface wear, and therefore it is necessary to reduce contamination of the charging roller.

Therefore, as shown in FIG. 6, the charging roller 12 is provided with a gap forming member 12a and is disposed close to the photoreceptor 1 via the gap, so that the contaminants are not easily attached to the charging roller or are easily removed. It is possible to reduce those effects.
In this case, the gap between the photoreceptor 1 and the charging roller 12 is preferably small, for example, 100 μm or less is preferable, and 50 μm or less is more preferable.
However, by making the charging roller non-contact, discharge may become non-uniform and charging of the photoreceptor may become unstable. Such a problem is caused by maintaining the charging stability by superimposing the alternating current component on the direct current component, thereby making it possible to simultaneously reduce the influence of ozone, the charging roller contamination and the charging effect. .

On the other hand, light sources such as the image exposure unit 13 and the charge removal lamp 11 shown in FIG. 5 include fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light emitting diodes (LEDs), semiconductor lasers (LDs), and electroluminescence (ELs). ) And other luminescent materials can be used. Among these, a semiconductor laser (LD) and a light emitting diode (LED) are mainly used.
Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.
The light source or the like irradiates the photoreceptor 1 with light by providing a transfer process, a static elimination process, a cleaning process, or a pre-exposure process using light irradiation together. However, the exposure of the photosensitive member 1 in the charge removal step is greatly affected by fatigue on the photosensitive member 1, and may cause a decrease in charge and an increase in residual potential. Therefore, there is a case where it is possible to eliminate static electricity by applying a reverse bias in the charging process or cleaning process instead of static elimination by exposure, which may be effective from the viewpoint of enhancing the durability of the photoreceptor.

When the electrophotographic photoreceptor 1 is positively (negatively) charged and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photoreceptor. A positive image can be obtained by developing this with negative (positive) toner (electrodetection fine particles), and a negative image can be obtained by developing with positive (negative) toner. A known method is applied to the developing unit, and a known method is also used for the charge eliminating unit.
As the transfer means, the above-described charger can be generally used. However, as shown in FIG. 5, a combination of the transfer charger 18 and the separation charger 19 is effective.
Further, the toner image is directly transferred from the photosensitive member 1 to paper using such transfer means. In the present invention, the toner image on the photosensitive member is once transferred to the intermediate transfer member, and then from the intermediate transfer member. An intermediate transfer system that transfers to paper is more preferable for improving the durability or image quality of the photoreceptor.
Among the contaminants that adhere to the surface of the photoconductor, discharge substances generated by charging and external additives contained in the toner are easy to pick up the effects of humidity and cause abnormal images. Paper powder is one of the causative substances, and when they adhere to the photoreceptor, abnormal images are more likely to occur, as well as a tendency to reduce wear resistance and cause uneven wear. Is seen. Therefore, it is more preferable from the viewpoint of high image quality that the photoconductor and the paper are not in direct contact for the above reason.

The intermediate transfer method is particularly effective for image forming apparatuses capable of full-color printing, and controls the prevention of color misregistration by forming a plurality of toner images on the intermediate transfer member and then transferring them to the paper at once. It is easy and effective for high image quality. However, the intermediate transfer method requires four scans to obtain one full-color image, so that the durability of the photoconductor has been a big problem. Since the image blur hardly occurs even without a drum heater, the photoconductor is easy to use in combination with an intermediate transfer type image forming apparatus, and is particularly effective and useful. The intermediate transfer member includes various materials or shapes such as a drum shape and a belt shape. In the present invention, any conventionally known intermediate transfer member can be used. It is effective and useful for achieving high quality or high image quality.
The toner developed on the photosensitive member 1 by the developing unit 14 shown in FIG. 5 is transferred to the recording medium 17, but not all is transferred, and toner remaining on the photosensitive member 1 is also generated.

Such toner is removed from the photoreceptor 1 by the cleaning brush 22 or the cleaning blade 23. The cleaning process may be performed only with a cleaning brush or may be performed in combination with a cleaning blade. As the cleaning brush, known ones such as a fur brush and a mag fur brush are used. As described above, the cleaning is a process of removing the toner remaining on the photosensitive member 1 after the transfer. Abnormal images may occur due to accelerated wear or scratches.
In addition, if the surface of the photoconductor is contaminated due to poor cleaning, it not only causes an abnormal image, but also significantly reduces the life of the photoconductor. In particular, in the case of a photoconductor with a protective layer on the outermost layer to improve wear resistance, it is difficult to remove contaminants adhering to the surface of the photoconductor, which promotes the generation of filming and abnormal images. Will do. Therefore, improving the cleaning property of the photoreceptor 1 is very effective for improving the durability and image quality of the photoreceptor.

  As a means for improving the cleaning property of the photosensitive member 1, a method of reducing the friction coefficient on the surface of the photosensitive member is known. Methods for reducing the coefficient of friction on the surface of the photoreceptor are classified into a method in which various lubricants are contained in the photoreceptor surface and a method in which the lubricant is supplied to the photoreceptor surface from the outside. The former is advantageous for small-diameter photoreceptors because of the high degree of freedom in layout around the engine, but the coefficient of friction increases remarkably with repeated use, and there remains a problem in its sustainability. On the other hand, the latter needs to be provided with a component for supplying a lubricating substance, but is effective for enhancing the durability of the photoreceptor because of high stability of the friction coefficient. Among them, the method of adhering to the photoreceptor during development by incorporating a lubricant into the developer is not restricted by the layout around the engine, and the effect of reducing the friction coefficient on the photoreceptor surface is high. Therefore, it is a very effective means for improving the durability and image quality of the photoreceptor.

  Examples of the lubricating substances include lubricating liquids such as silicone oil and fluorine oil, various fluorine-containing resins such as PTFE, PFA, and PVDF, silicone resins, polyolefin resins, silicone grease, fluorine grease, paraffin wax, and fatty acid esters. And fatty acid metal salts such as zinc stearate, lubricating liquids such as graphite and molybdenum disulfide, solids, and powders. Among these, when mixed with a developer, it needs to be in a powder form, and zinc stearate has little adverse effect and can be used very effectively. When the zinc stearate powder is contained in the toner, it is necessary to consider the balance and the influence on the toner, and the content is preferably 0.01% by mass to 0.5% by mass with respect to the toner. 1 mass%-0.3 mass% is more preferable.

  The electrophotographic photosensitive member of the present invention can be applied to a small-diameter photosensitive member because it realizes high photosensitivity and high stability. As an image forming apparatus or a system thereof in which the photosensitive member is used more effectively, each developing unit corresponding to a plurality of color toners is provided with a plurality of corresponding photosensitive members, thereby performing parallel processing. It is very effectively used in a so-called tandem image forming apparatus. The tandem image forming apparatus includes at least four color toners of yellow (C), magenta (M), cyan (C), and black (K) required for full-color printing and a developing unit that holds them. Further, by providing at least four photoconductors corresponding to them, full-color printing can be performed at a very high speed as compared with a conventional image forming apparatus capable of full-color printing.

FIG. 7 is a schematic view for explaining the tandem-type full-color electrophotographic apparatus of the present invention, and the following modifications also belong to the category of the present invention.
In FIG. 7, photoconductors 1C (cyan), 1M (magenta), 1Y (yellow), and 1K (black) are drum-like photoconductors 1, and these photoconductors 1C, 1M, 1Y, and 1K are illustrated in FIG. 7, charging means 12C, 12M, 12Y, and 12K, developing means 14C, 14M, 14Y, and 14K, and cleaning means 15C, 15M, 15Y, and 15K are disposed at least in the order of rotation.

  The charging means 12C, 12M, 12Y, and 12K constitute a charging means for uniformly charging the surface of the photoreceptor 1. Laser beams 13C, 13M, 13Y, and 13K from an exposure unit (not shown) are irradiated from the back side of the photoreceptor 1 between the charging units 12C, 12M, 12Y, and 12K and the developing units 14C, 14M, 14Y, and 14K. Thus, electrostatic latent images are formed on the photoreceptors 1C, 1M, 1Y, and 1K.

  Then, four image forming elements 10C, 10M, 10Y, and 10K centering on the photoreceptors 1C, 1M, 1Y, and 1K are juxtaposed along a conveyance belt 25 that is a recording medium conveyance unit. The conveyor belt 25 is provided between the developing units 14C, 14M, 14Y, and 14K of the image forming units (elements) 10C, 10M, 10Y, and 10K and the cleaning units 15C, 15M, 15Y, and 15K, and the photoreceptors 1C, 1M, and 15K. Transfer brushes 26 </ b> C, 26 </ b> M, 26 </ b> Y, and 26 </ b> K for applying a transfer bias are disposed on a surface (back surface) that is in contact with 1 </ b> Y and 1 </ b> K and contacts the back side of the conveyance belt 25 on the photoconductor 1 side. Each of the image forming elements 10C, 10M, 10Y, and 10K is different in the color of the toner inside the developing unit, and the rest is the same in configuration.

  In the color electrophotographic image forming apparatus having the configuration shown in FIG. 7, the image forming operation is performed as follows. First, in each of the image forming elements 10C, 10M, 10Y, and 10K, the photoreceptors 1C, 1M, 1Y, and 1K are charged by the charging units 12C, 12M, 12Y, and 12K that rotate in the direction of the arrow (the direction along with the photoreceptor 1). Next, an electrostatic latent image corresponding to each color image to be created is formed by laser light 13C, 13M, 13Y, and 13K by an exposure unit (not shown) disposed outside the photosensitive member 1 after being charged.

Next, the latent image is developed by the developing means 14C, 14M, 14Y, and 14K to form a toner image. Developing means 14C, 14M, 14Y, and 14K are developing means for developing with toners of C (cyan), M (magenta), Y (yellow), and K (black), respectively. , 1K toner images are superimposed on the recording medium. The recording medium 17 is sent out from the tray by a paper feed roller 24, temporarily stopped by a pair of registration rollers 16, and sent to the transfer conveyance belt 25 in synchronization with the image formation on the photosensitive member.
The recording medium 17 held on the conveyor belt 25 is conveyed, and the toner images of each color are transferred at the contact positions (transfer portions) with the photoreceptors 1C, 1M, 1Y, 1K.

The toner image on the photoconductor is transferred onto the recording paper 17 by an electric field formed by a potential difference between the transfer bias applied to the transfer brushes 26C, 26M, 26Y, and 26K and the photoconductors 1C, 1M, 1Y, and 1K. The Then, the recording paper 17 on which the four color toner images are passed through the four transfer portions is conveyed to the fixing means 27, where the toner is fixed, and is discharged to a paper discharge portion (not shown). Further, the residual toner that remains on the photoreceptors 1C, 1M, 1Y, and 1K without being transferred by the transfer unit is collected by the cleaning units 15C, 15M, 15Y, and 15K.
In the example of FIG. 7, the image forming elements are arranged in the order of C (cyan), M (magenta), Y (yellow), and K (black) from the upstream side to the downstream side in the recording medium conveyance direction. However, the order is not limited to this order, and the color order is arbitrarily set. In addition, when a black-only document is created, it is particularly effective to use the present invention to provide a mechanism that stops the image forming elements 10C, 10M, and 10Y other than black.

Further, in FIG. 7, the charging means is in contact with the photosensitive member, but by using a charging mechanism as shown in FIG. In addition, the wear amount of the both can be reduced, and toner filming to the charging means can be reduced and the toner can be used satisfactorily.
The image forming means as described above may be fixedly incorporated in a copying apparatus, a facsimile, or a printer, but may be incorporated in these apparatuses in the form of a process cartridge.

Since the tandem image forming apparatus can transfer a plurality of toner images at a time, high-speed full-color printing is realized. However, since at least four photoconductors are required, an increase in the size of the image forming apparatus is unavoidable, and depending on the amount of toner used, there is a difference in the amount of wear of each photoconductor, thereby causing the color to change. There are many problems such as a decrease in reproducibility of images and occurrence of abnormal images.
On the other hand, the electrophotographic photoreceptor of the present invention can be applied to a small-diameter photoreceptor by realizing high photosensitivity and high stability, and the influence of increase in residual potential, sensitivity deterioration, etc. is reduced. Even if the usage amounts of the four photoconductors are different, the difference in residual potential and sensitivity over time of repeated use is small, and it is possible to obtain a full color image having excellent color reproducibility even when used repeatedly for a long time.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

  First, the synthesis example of the gallium phthalocyanine compound represented by the general formula (A) in the present invention is shown below.

(Synthesis example A of chlorogallium phthalocyanine)
It was produced after adding 30 parts by mass of 1,3-diiminoisoindoline and 8 parts by mass of gallium trichloride to 200 mL of dehydrated dimethyl sulfoxide and reacting at 150 ° C. for 12 hours in an argon (Ar) stream. Chlorogallium phthalocyanine was filtered off. This wet cake was washed with methyl ethyl ketone and N, N-dimethylformamide and then dried to obtain 22 parts by mass (70.3% by mass) of chlorogallium phthalocyanine crystals.

(Synthesis example B of hydroxygallium phthalocyanine)
5 parts by mass of chlorogallium phthalocyanine of Synthesis Example A was dissolved in 150 parts by mass of ice-cooled concentrated sulfuric acid, and this sulfuric acid solution was gradually added dropwise to 500 mL of ice-cooled ion exchange water to precipitate hydroxygallium phthalocyanine crystals. . After the crystals were filtered off, the wet cake was washed with 500 mL of 2% by mass ammonia water, and then thoroughly washed with ion-exchanged water. By drying, 4.6 parts by mass of hydroxygallium phthalocyanine crystal was obtained.

(Synthesis example of gallium phthalocyanine compound represented by the following structural formula (C))
To 100 mL of ethyl acetate, 0.60 parts by mass of hydroxygallium phthalocyanine of Synthesis Example B and 1.9 parts by mass of 3-trifluoromethylbenzoic acid were added, and the reaction was performed under reflux for 8 hours. The obtained crystal was washed with methyl ethyl ketone and ion exchange water and then dried to obtain 0.71 part by mass (92% by mass) of a gallium phthalocyanine compound crystal.
As a result of analysis by infrared absorption spectrum (KBr tablet method) of the above product, absorption of about 3,480 cm ⁻¹ derived from OH group disappeared, and absorption of 1,662 cm ⁻¹ based on C═O stretching vibration was observed. It was. By further LDI-TOFMS (negative), m / z: 770.00 (Theoretical value _770.09: as _{C 40 H 20 F 3 GaN 8} O 2) was observed. The results of further elemental analysis are shown in Table 1.
From these results, it was confirmed that it was a gallium phthalocyanine compound represented by the structural formula (C).

(Synthesis example of gallium phthalocyanine compound represented by the following structural formula (D))
1.20 parts by mass of hydroxygallium phthalocyanine of Synthesis Example B and 15.66 parts by mass of 4-chlorobenzoic acid are added to a mixed solvent of 100 mL of methyl ethyl ketone and 50 mL of N, N-dimethylformamide, and reacted at 100 ° C. for 7 hours. Went. The obtained crystals were washed with a mixed solvent of 50 mL of methyl ethyl ketone and 50 mL of N, N-dimethylformamide, then methyl ethyl ketone, and finally ion-exchanged water. By drying, 1.41 parts by mass (95% by mass) of a gallium phthalocyanine compound crystal was obtained.
As a result of analysis by infrared absorption spectrum (KBr tablet method) of the above product, absorption of about 3,480 cm ⁻¹ derived from OH group disappeared, and absorption of 1,654 cm ⁻¹ based on C═O stretching vibration was observed. It was. Further by LDI-TOFMS (positive), m / z: 735.97 (Theoretical value _736.07: as _{C 39 H 20 GaClN 8 O 2} ) was observed. The results of further elemental analysis are shown in Table 2.
From these results, it was confirmed that it was a gallium phthalocyanine compound represented by the structural formula (D).

(Synthesis example of gallium phthalocyanine compound represented by the following structural formula (E))
1.20 parts by mass of hydroxygallium phthalocyanine of Synthesis Example B and 8.48 parts by mass of pentafluorobenzoic acid were added to 100 mL of N, N-dimethylformamide, and the reaction was carried out at 100 ° C. for 7 hours. The obtained crystals were washed with 100 mL of N, N-dimethylformamide, then with methyl ethyl ketone, and finally with ion-exchanged water. By drying, 1.15 parts by mass (72% by mass) of a gallium phthalocyanine compound crystal was obtained.
As a result of analysis by infrared absorption spectrum (KBr tablet method) of the above product, absorption of about 3,480 cm ⁻¹ derived from OH group disappeared, and absorption of 1,678 cm ⁻¹ based on C═O stretching vibration was observed. It was. Further elemental analysis was performed (theoretical value: C ₃₉ H ₁₆ F ₅ GaN ₈ O ₂ ). The results are shown in Table 3.
From these results, it was confirmed that it was a gallium phthalocyanine compound represented by the structural formula (E).

(Synthesis example of gallium phthalocyanine compound represented by the following structural formula (F))
To a mixed solvent of 100 mL of methyl ethyl ketone and 100 mL of N, N-dimethylformamide, 1.20 parts by mass of hydroxygallium phthalocyanine of Synthesis Example B and 16.52 parts by mass of 4-dimethylaminobenzoic acid are added, and the mixture is heated at 100 ° C. for 7 hours. Reaction was performed. The obtained crystals were washed with a mixed solvent of 80 mL of methyl ethyl ketone and 80 mL of N, N-dimethylformamide, then methyl ethyl ketone, and finally with ion-exchanged water, and then dried to obtain 1.47 parts by mass (98% by mass) of gallium. A phthalocyanine compound crystal was obtained.
As a result of analysis by infrared absorption spectrum (KBr tablet method) of the above product, absorption at about 3,480 cm ⁻¹ derived from OH group disappeared, and absorption at 1,645 cm ⁻¹ based on C═O stretching vibration was observed. It was. By further LDI-TOFMS (positive), m / z: 745.04 (Theoretical value _745.15: as _{C 41 H 26 GaN 9 O 2} ) was observed. The results of further elemental analysis are shown in Table 4.
From these results, it was confirmed that it was a gallium phthalocyanine compound represented by the structural formula (F).

(Synthesis example of azo compound having carboester group)
Next, an azo compound having a carboester group represented by the general formula (I): A (E) n is synthesized by a method described in JP-A-2009-7523. Show.

(1) Synthesis example C of exemplary compound (12-2)
Precursor of azo compound having a carboester group represented by the structural formula (12-2) [all E groups in the structural formula (12-2) are H (hydrogen atoms)] 1.61 g , And 4.3 g (10-fold mol) of pyrocarboxylic acid di-tert-butyl ester were dispersed in 50 mL of dehydrated pyridine and 200 mL of dehydrated N, N-dimethylformamide, stirred at room temperature for 15 minutes, and further about 50 ° C. And allowed to react for 2 hours. Gradually reddish and a homogeneous solution was obtained. It returned to room temperature, the solvent was removed, and about 100 mL of ethyl acetate was added, and 2.24 g (yield 93 mass%) red powder was obtained.
The results of elemental analysis of the obtained powder are shown in Table 5 below.
In addition, the calculated value (%) of each element in the following Table 5 is that in which all the carboester groups (E groups) whose products are represented by the structural formula (12-2) are C ₅ H ₉ O _2. And the chemical formula of the azo compound is calculated as C ₆₈ H ₆₃ N ₆ O ₁₃ Cl.
As a result of analysis by infrared absorption spectrum (KBr tablet method) of the product, absorption derived from a substituent, i.e., absorption based on saturated hydrocarbons 2,980cm ^-1, C of carbonate to 1,760Cm ^-1 = O Absorption based on stretching vibration was observed.

(Composite Pigment Synthesis Example 1)
Precursor of azo compound having 0.90 parts by mass of hydroxygallium phthalocyanine of Synthesis Example B, 5.7 parts by mass of 3-trifluoromethylbenzoic acid, and a carboester group represented by the structural formula (12-3) [all E groups represented by the structural formula (12-3) is _C 5 _H 9 _{O 2} in which those] 0.92 parts by mass of N, with N- dimethylformamide 100 mL, reacted for 7 hours at 130 ° C. went. The obtained crystals were washed with N, N-dimethylformamide and methyl ethyl ketone, and further ion-exchanged water, and then dried to obtain 1.48 parts by mass (83% by mass) of composite pigment crystals.
As a result of analysis by infrared absorption spectrum (KBr tablet method) of the above product, absorption of about 3,480 cm ⁻¹ derived from OH group disappeared, absorption of 1,662 cm ⁻¹ based on C═O stretching vibration, and 1,722Cm ^-1 based on azo compounds, the absorption of 1,676Cm ^-1 was observed.
From this, it is a composite pigment composed of a gallium phthalocyanine compound represented by the structural formula (C) and an azo compound in which all of the E groups in the structural formula (12-3) are H (hydrogen atoms). confirmed.

(Synthesis example 2 of composite pigment)
Precursor of azo compound having a carboester group represented by the structural formula (12-3), 0.90 part by mass of hydroxygallium phthalocyanine of Synthesis Example B, 6.36 parts by mass of pentafluorobenzoic acid All of the E groups represented by the formula (12-3) are C ₅ H ₉ O ₂ ] 0.92 parts by mass in 100 mL of N, N-dimethylformamide at 130 ° C. for 2 hours, further 153 ° C. The reaction was carried out for 2 hours. The obtained crystals were washed with N, N-dimethylformamide, methyl ethyl ketone, and ion-exchanged water, and then dried to obtain 1.40 parts by mass (77% by mass) of composite pigment crystals.
As a result of analysis by infrared absorption spectrum (KBr tablet method) of the above product, absorption of about 3,480 cm ⁻¹ derived from OH group disappeared, and 1,724 cm ⁻¹ based on azo compound, ester group and amide group A broad absorption of 1,675 cm ⁻¹ based on C═O stretching vibration was observed.
From this fact, it is a composite pigment composed of a gallium phthalocyanine compound represented by the structural formula (E) and an azo compound in which all of the E groups in the structural formula (12-3) are H (hydrogen atoms). confirmed.

(Composite Pigment Synthesis Example 3)
Precursor of azo compound having 0.90 parts by mass of hydroxygallium phthalocyanine of Synthesis Example B, 4.96 parts by mass of 4-dimethylaminobenzoic acid, and a carboester group represented by the structural formula (12-2) [All of the E groups represented by the structural formula (12-2) are C ₅ H ₉ O ₂ ] 0.91 part by mass in 100 mL of N, N-dimethylformamide at 130 ° C. for 2 hours and further 153 The reaction was carried out at 2 ° C for 2 hours. The obtained crystals were washed with N, N-dimethylformamide, methyl ethyl ketone, and ion-exchanged water, and then dried to obtain 1.62 parts by mass (94% by mass) of composite pigment crystals.
As a result of analysis by infrared absorption spectrum (KBr tablet method) of the above product, absorption at about 3480 cm ⁻¹ derived from OH group disappeared, absorption at 1,645 cm ⁻¹ based on C═O stretching vibration and azo compound 1,724 cm ⁻¹ , 1,674 cm ⁻¹ absorption was observed.
From this fact, it is a composite pigment comprising a gallium phthalocyanine compound represented by the structural formula (F) and an azo compound in which all E groups in the structural formula (12-2) are H (hydrogen atoms). confirmed.

(Synthesis example 4 of composite pigment)
0.90 parts by mass of hydroxygallium phthalocyanine of Synthesis Example B, 4.70 parts by mass of 4-chlorobenzoic acid, and an azo in which all of the E groups in the structural formula (12-1) are H (hydrogen atom) Reaction was performed at 130 ° C. for 5 hours in 100 mL of N, N-dimethylformamide with 0.21 part by mass of the compound. The obtained crystals were washed with N, N-dimethylformamide, methyl ethyl ketone, and ion-exchanged water, and then dried to obtain 1.16 parts by mass (88% by mass) of composite pigment crystals.
As a result of analysis by infrared absorption spectrum (KBr tablet method) of the above product, absorption of about 3,480 cm ⁻¹ derived from OH group disappeared, absorption of 1,654 cm ⁻¹ based on C═O stretching vibration, and 1,723Cm ^-1 based on azo compounds, the absorption of 1,676Cm ^-1 was observed.
From this fact, it is a composite pigment composed of a gallium phthalocyanine compound represented by the structural formula (D) and an azo compound in which all the E groups in the structural formula (12-1) are H (hydrogen atoms). confirmed.

(Synthesis example 5 of composite pigment)
In 100 mL of ethyl acetate, 0.60 parts by mass of hydroxygallium phthalocyanine of Synthesis Example B, 1.9 parts by mass of 3-trifluoromethylbenzoic acid, and all of the E groups in the structural formula (12-6) are H ( 0.83 parts by mass of an azo compound (hydrogen atom) was added, and the reaction was carried out under reflux for 8 hours. The obtained crystals were washed with methyl ethyl ketone and ion-exchanged water, and then dried to obtain 1.46 parts by mass (91% by mass) of composite pigment crystals.
As a result of analysis by infrared absorption spectrum (KBr tablet method) of the above product, absorption of about 3,480 cm ⁻¹ derived from OH group disappeared, absorption of 1,662 cm ⁻¹ based on C═O stretching vibration, and 1,722Cm ^-1 based on azo compounds, the absorption of 1,676Cm ^-1 was observed.
From this, it is a composite pigment comprising a gallium phthalocyanine compound represented by the structural formula (C) and an azo compound in which all of the E groups in the structural formula (12-6) are H (hydrogen atoms). confirmed.

(Synthesis example 6 of composite pigment)
1.48 parts by mass of the gallium phthalocyanine compound represented by Structural Formula (D) obtained in Synthesis Example 4 and a precursor of an azo compound having a carboester group represented by Structural Formula (12-4) [ All E groups represented by structural formula (12-4) are C ₅ H ₉ O ₂ ] 0.89 parts by mass in 100 mL of N, N-dimethylformamide at 130 ° C. for 2 hours, further 153 The reaction was carried out at 4 ° C. for 4 hours. The obtained crystals were washed with N, N-dimethylformamide and methyl ethyl ketone, and further ion-exchanged water, and then dried to obtain 1.80 parts by mass (87% by mass) of composite pigment crystals.
Analysis by infrared absorption spectrum (KBr tablet method) of the product, absorption and 1,654Cm ^-1 based on C = O stretching vibration, the absorption of 1,723cm ^-1, 1,676cm ^-1 based on azo compounds Was recognized.
From this fact, it is a composite pigment composed of a gallium phthalocyanine compound represented by the structural formula (D) and an azo compound in which all E groups in the structural formula (12-4) are H (hydrogen atoms). confirmed.

(Synthesis Example 7 of composite pigment)
1.19 parts by mass of the gallium phthalocyanine compound of the structural formula (E) obtained in Synthesis Example 2 and a precursor of an azo compound having a carboester group represented by the structural formula (13-1) [Structural Formula ( 13-1) in which all E groups are C ₅ H ₉ O ₂ ] 1.01 part by mass in 100 mL of N, N-dimethylformamide at 130 ° C. for 2 hours and further at 153 ° C. 6 Time reaction was performed. The obtained crystals were washed with N, N-dimethylformamide and methyl ethyl ketone, and further ion-exchanged water, and then dried to obtain 1.54 parts by mass (81% by mass) of composite pigment crystals.
As a result of analysis by infrared absorption spectrum (KBr tablet method) of the above product, a broad absorption of 1,670 cm ⁻¹ based on C═O stretching vibration was observed.
This confirmed that the composite pigment was composed of a gallium phthalocyanine compound of the structural formula (E) and an azo compound in which all of the E groups in the structural formula (13-1) are H (hydrogen atoms).

(Composite Pigment Synthesis Example 8)
Synthesis example of composite pigment comprising gallium phthalocyanine compound represented by structural formula (H) below and azo compound in which all E groups in structural formula (13-1) are H (hydrogen atom)
In 100 mL of chlorobenzene, 0.62 parts by mass of chlorogallium phthalocyanine of Synthesis Example A, 23 parts by mass of trifluoroacetic acid, and a precursor of an azo compound having a carboester group represented by the structural formula (13-1) [Structural formula Those in which all E groups represented by (13-1) are C ₅ H ₉ O ₂ ] 0.27 parts by mass were added, and the mixture was heated to 90 ° C. and reacted for 5 hours. After cooling, about 10 mL of distilled water was added and stirred at room temperature for 1 hour. The obtained crystals were washed with methyl ethyl ketone and ion-exchanged water and then dried to obtain 0.83 parts by mass (86% by mass) of composite pigment crystals.
Analysis by infrared absorption spectrum of this product (KBr tablet method), the absorption of 1,732Cm ^-1 and 1,668Cm ^-1 based on C = O stretching vibration was observed. From this, it is a composite pigment comprising the gallium phthalocyanine compound represented by the structural formula (H) and an azo compound in which all of the E groups in the structural formula (13-1) are H (hydrogen atoms). It was confirmed.

(Composite Pigment Synthesis Example 9)
3.15 parts by mass of a gallium phthalocyanine compound represented by the following structural formula (G) and 1.01 parts by mass of an azo compound in which all of the E groups in the structural formula (14-1) are H (hydrogen atoms) Ball mill dispersion was performed for 2 hours together with glass balls having a diameter of 1 mm and N, N-dimethylformamide. The obtained crystal was washed with N, N-dimethylformamide and methyl ethyl ketone, and further ion-exchanged water, and then dried to give 3.95 parts by mass (95% by mass) of gallium phthalocyanine represented by the following structural formula (G) A composite pigment comprising a compound and an azo compound in which all of the E groups in the structural formula (14-1) are H (hydrogen atoms) was obtained.

Example 1
<Production of electrophotographic photoreceptor>
After dip coating on an aluminum cylinder having a length of 346 mm and a diameter (φ) of 40 mm using an intermediate layer coating solution having the following composition, drying was performed at 130 ° C. for 20 minutes to form an intermediate layer having a thickness of 3.5 μm. Formed. Subsequently, a charge generation layer coating solution having the following composition was ball milled for 2 hours together with zirconia balls having a diameter (φ) of 5 mm, and after dip coating using this coating solution, drying was performed at 100 ° C. for 30 minutes. The charge generation layer having a thickness of 0.3 μm was formed.
Furthermore, after dip-coating using a coating solution for a charge transport layer having the following composition, drying was performed at 130 ° C. for 20 minutes to form a charge transport layer having a thickness of 20 μm. Thus, the electrophotographic photosensitive member of Example 1 was produced.

-Intermediate layer coating solution-
Titanium oxide (CR-EL, manufactured by Ishihara Sangyo Co., Ltd.): 50 parts by mass 60, solid content 60% by mass, manufactured by DIC): 8 parts by mass 2-butanone: 120 parts by mass

-Coating solution for charge generation layer-
-Composite pigment obtained in Synthesis Example 1: 3.0 parts by mass-Polyvinyl butyral ("XYHL", manufactured by UCC): 2 parts by mass-Methyl ethyl ketone: 150 parts by mass

-Coating liquid for charge transport layer-
Polycarbonate (Z Polyca, Teijin Chemicals Ltd., Panlite TS-2050): 10 parts by mass Charge-transporting compound represented by the following structural formula: 7 parts by mass
Tetrahydrofuran: 80 parts by mass Silicone oil (KF50-100cs, manufactured by Shin-Etsu Chemical Co., Ltd.): 0.002 parts by mass

(Example 2)
-Production of electrophotographic photoreceptor-
In Example 1, Example 2 was performed in the same manner as Example 1 except that the composite pigment obtained in Synthesis Example 1 of the charge generation layer coating solution was replaced with the composite pigment obtained in Synthesis Example 2. An electrophotographic photoreceptor was prepared.

(Example 3)
-Production of electrophotographic photoreceptor-
In Example 1, Example 3 was carried out in the same manner as Example 1 except that the composite pigment obtained in Synthesis Example 1 of the charge generation layer coating solution was replaced with the composite pigment obtained in Synthesis Example 3. An electrophotographic photoreceptor was prepared.

Example 4
-Production of electrophotographic photoreceptor-
In Example 1, Example 4 was repeated in the same manner as Example 1 except that the composite pigment obtained in Synthesis Example 1 of the charge generation layer coating solution was replaced with the composite pigment obtained in Synthesis Example 4. An electrophotographic photoreceptor was prepared.

(Example 5)
-Production of electrophotographic photoreceptor-
In Example 1, Example 5 was performed in the same manner as Example 1 except that the composite pigment obtained in Synthesis Example 1 of the coating solution for charge generation layer was replaced with the composite pigment obtained in Synthesis Example 5. An electrophotographic photoreceptor was prepared.

(Example 6)
-Production of electrophotographic photoreceptor-
In Example 1, Example 6 was performed in the same manner as in Example 1 except that the composite pigment obtained in Synthesis Example 1 of the charge generation layer coating solution was replaced with the composite pigment obtained in Synthesis Example 6. An electrophotographic photoreceptor was prepared.

(Example 7)
-Production of electrophotographic photoreceptor-
In Example 1, Example 7 was carried out in the same manner as Example 1 except that the composite pigment obtained in Synthesis Example 1 of the coating solution for charge generation layer was replaced with the composite pigment obtained in Synthesis Example 7. An electrophotographic photoreceptor was prepared.

(Example 8)
-Production of electrophotographic photoreceptor-
In Example 1, Example 8 was carried out in the same manner as Example 1 except that the composite pigment obtained in Synthesis Example 1 of the charge generation layer coating solution was replaced with the composite pigment obtained in Synthesis Example 8. An electrophotographic photoreceptor was prepared.

Example 9
-Production of electrophotographic photoreceptor-
In Example 1, Example 9 was carried out in the same manner as Example 1 except that the composite pigment obtained in Synthesis Example 1 of the charge generation layer coating solution was replaced with the composite pigment obtained in Synthesis Example 9. An electrophotographic photoreceptor was prepared.

(Comparative Example 1)
-Production of electrophotographic photoreceptor-
In Example 1, except that the composite pigment obtained in Synthesis Example 1 of the charge generation layer coating solution was replaced with the gallium phthalocyanine compound represented by the structural formula (C), the same as in Example 1, An electrophotographic photosensitive member of Comparative Example 1 was produced.

(Comparative Example 2)
-Production of electrophotographic photoreceptor-
In Example 1, the composite pigment obtained in Synthesis Example 1 of the charge generation layer coating solution was replaced with an azo compound in which all of the E groups in the structural formula (12-3) are H (hydrogen atoms). An electrophotographic photosensitive member of Comparative Example 2 was produced in the same manner as Example 1 except for the above.

(Comparative Example 3)
-Production of electrophotographic photoreceptor-
In Example 1, except that the composite pigment obtained in Synthesis Example 1 of the coating solution for charge generation layer was replaced with Y-type titanyl phthalocyanine (manufactured by Toyo Ink Manufacturing Co., Ltd., Rio Photon-TOPA). Similarly, an electrophotographic photoreceptor of Comparative Example 3 was produced.

(Comparative Example 4)
-Production of electrophotographic photoreceptor-
In Example 1, the composite pigment obtained in Synthesis Example 1 of the charge generation layer coating solution was used as a precursor of an azo compound having a carboester group represented by Structural Formula (12-3) [Structural Formula (13 The electrophotographic photosensitive member of Comparative Example 4 was produced in the same manner as in Example 1 except that all of the E groups represented by -2) were replaced with C ₅ H ₉ O ₂ .

(Comparative Example 5)
-Production of electrophotographic photoreceptor-
In Example 1, except that the composite pigment obtained in Synthesis Example 1 of the coating solution for charge generation layer was replaced with the composite pigment obtained in Synthesis Example 10 shown below, the same as in Example 1, An electrophotographic photosensitive member of Comparative Example 5 was produced.
<Synthesis Example 10 of Composite Pigment>
0.90 parts by mass of hydroxygallium phthalocyanine of Synthesis Example B and a precursor of an azo compound having a carboester group represented by the structural formula (12-3) [E group represented by the structural formula (12-3) All of the above are C ₅ H ₉ O ₂ ] 0.92 parts by mass were reacted in 100 mL of N, N-dimethylformamide at 130 ° C. for 7 hours. The obtained crystals were washed with N, N-dimethylformamide and methyl ethyl ketone, and further ion-exchanged water, and then dried to obtain 0.78 parts by mass of composite pigment crystals.

(Comparative Example 6)
-Production of electrophotographic photoreceptor-
In Example 1, except that the composite pigment obtained in Synthesis Example 1 of the charge generation layer coating solution was replaced with the composite pigment obtained in Synthesis Example 11 shown below, the same as in Example 1, An electrophotographic photoreceptor of Comparative Example 6 was produced.
<Synthesis Example 11 of Composite Pigment>
0.90 parts by mass of chlorogallium phthalocyanine of Synthesis Example A and a precursor of an azo compound having a carboester group represented by the structural formula (12-3) [E group represented by the structural formula (12-3) All of the above are C ₅ H ₉ O ₂ ] 0.92 parts by mass were reacted in 100 mL of N, N-dimethylformamide at 130 ° C. for 7 hours. The obtained crystals were washed with N, N-dimethylformamide and methyl ethyl ketone, and further ion-exchanged water, and then dried to obtain 0.75 parts by mass of composite pigment crystals.

<Evaluation of actual machine>
As shown in FIG. 8, the produced electrophotographic photoreceptors of Examples 1 to 9 and Comparative Examples 1 to 6 were mounted on a process cartridge from which a lubricant application member was removed, and a digital full-color composite machine (imagino MPC5000, manufactured by Ricoh Co., Ltd.). ).
As the process conditions during the test, the applied voltage to the charging means was set so that the charged potential of the unexposed area was −800V. The development bias was set to -600V. As a sheet passing condition, 40,000 sheets were printed using a chart with a writing rate of 6% (characters equivalent to 6% as an image area are written on the entire A4 size surface). The test environment includes a normal temperature and normal humidity environment (temperature: 23 ° C., relative humidity: 55% RH), a high temperature and high humidity environment (temperature: 30 ° C., relative humidity: 80% RH), and a low temperature and low humidity environment (temperature: 10). The same printing test was performed under three environmental conditions (° C., relative humidity: 15% RH).

<Image evaluation>
The image evaluation was performed before and after the printing of 40,000 images. 5-2 was output, and the image density, resolution, and color color reproducibility were evaluated as follows. The results are shown in Table 6.
In addition, the image evaluation was performed in the same manner as described above using the applied voltage of the charging unit in which the charging potential of the unexposed portion was −500 V before the printing test. The results are shown in Table 7.

<Image density>
Before and after printing 40,000 images, test chart No. 5-2 was output, and the image density was measured by a reflection densitometer manufactured by Macbeth (modified so that it can measure up to 3 digits after the decimal point), and the image density difference before and after was evaluated according to the following criteria.
〔Evaluation criteria〕
◎: Image density difference is less than 0.1 ○: Image density difference is 0.1 or more and less than 0.2 Δ: Image density difference is 0.2 or more and less than 0.3 ×: Image density difference is 0.3 or more

<Resolution>
Before and after printing 40,000 images, test chart No. By outputting 5-2 and observing the dot formation state (dot dispersion and dot reproducibility) for the halftone part, the resolution was evaluated according to the following criteria.
〔Evaluation criteria〕
◎: Very good with no dot scatter ○: Slight dot scatter is observed but good △: Dot scatter and dot spread are poor ×: Dot scatter and dot spread are large and very bad

<Reproducibility of color>
Before and after printing 40,000 images, test chart No. 5-2 is output, and the chromaticity index a ^* and b ^* in the L ^* a ^* b ^* color system (CIE: 1976) is measured using a chromaticity meter (X-Rite 938, manufactured by X-Rite). Then, the value of saturation C ^{* represented} by the following formula was obtained, and color reproducibility was evaluated according to the following criteria.
Saturation C ^* = [(a ^* ) ² + (b ^* ) ² ] ^1/2
〔Evaluation criteria〕
◎: Saturation C ^* is 75 or more ○: Saturation C ^* is 73 or more and less than 75 △: Saturation C ^* is 70 or more and less than 73 ×: Saturation C ^* is less than 70

  Since the electrophotographic photosensitive member using the composite pigment of the present invention as a charge generation material can realize high image quality and high stability, for example, a laser printer, a direct digital plate making machine, a direct or indirect electrophotographic multicolor image development system Can be used widely for full-color copiers, full-color laser printers, full-color plain paper fax machines, etc.

1C, 1M, 1Y, 1K Photoconductor 10C, 10M, 10Y, 10K Image forming element 11 Static elimination lamp 12 Charging roller 12a Gap forming member 12C, 12M, 12Y, 12K Charging means 13 Image exposure unit 13C, 13M, 13Y, 13K Laser Light 14 Developing unit 14C, 14M, 14Y, 14K Developing means 15C, 15M, 15Y, 15K Cleaning means 16 Registration roller 17 Recording medium 18 Transfer charger 19 Separating charger 21 Pre-cleaning charger 22 Cleaning brush 23 Cleaning blade 24 Feed roller 25 Conveyance Belt 26C, 26M, 26Y, 26K Transfer brush 27 Fixing means 101 Electrophotographic photosensitive member 112 Charging means 113 Exposure by exposure means 114 Developing means 117 Recording medium 118 Transfer means 123 Cleaning Means 201 Electrophotographic Photoreceptor 202 Support 203 Charge Generation Layer 204 Charge Transport Layer 205 Protective Layer 206 Undercoat Layer 207 Single Layer Type Photosensitive Layer

JP 47-37543 A JP 52-55643 A JP-A-52-8832 JP 58-222152 A JP 58-222153 A Japanese Patent Laid-Open No. 61-239248 JP-A-1-17066 Japanese Patent Laid-Open No. 61-109056 JP-A 62-67094 Japanese Unexamined Patent Publication No. 63-364 JP-A-63-366 Japanese Patent Laid-Open No. 2005-15682 Japanese Unexamined Patent Publication No. 63-198067 JP-A-1-123868 US Pat. No. 3,357,989 JP 58-18239 A Japanese Patent Laid-Open No. 5-263007 Japanese Patent Laid-Open No. 5-279591 JP-A-58-100134 JP 61-273994 A JP-A-62-62367 JP 59-44053 A Japanese Patent Laid-Open No. 1-222159 JP 60-59355 A JP-A-5-301292 JP 2001-290296 A Japanese Patent Laid-Open No. 9-127711 JP 2002-23399 A JP 2007-334099 A Japanese Patent Laid-Open No. 3-9962

Claims (10)

A composite pigment comprising a gallium phthalocyanine compound represented by the following general formula (A) and an azo compound.
However, in the general formula (A), X has an alkyl group which may have a substituent, an alkenyl group which may have a substituent, an alkynyl group which may have a substituent, or a substituent. And an aralkyl group which may be substituted, a cycloalkyl group which may have a substituent, an aryl group which may have a substituent, and a hydrogen atom. R ^{1 to} R ¹⁶ each independently represent any of a hydrogen atom, an alkoxy group, an alkylthio group, an alkyl group, a halogen atom, a nitro group, and an aryl group. n is an integer of 1 to 3. The composite pigment according to claim 1, wherein the gallium phthalocyanine compound is represented by the following general formula (B).
However, in said general formula (B), Y represents the aryl group which may have a substituent, and the said substituent is an alkoxy group, an alkylthio group, an alkyl group, a halogen atom, a nitro group, an amino group, an aryl. Represents any of a group, a carboxy group, and a cyano group. n is an integer of 1 to 3. The composite pigment according to claim 1, wherein the gallium phthalocyanine compound is at least one selected from compounds represented by the following structural formulas (C) and (E) to (G).
  The gallium phthalocyanine compound represented by the general formula (A) is obtained by reacting either a halogenated gallium phthalocyanine or a hydroxygallium phthalocyanine with a carboxylic acid compound. Composite pigments. A gallium phthalocyanine compound represented by the general formula (A) is produced by reacting either a halogenated gallium phthalocyanine or a hydroxygallium phthalocyanine with a carboxylic acid compound, and at least one of a chemical method and a thermal method. From an azo compound represented by the following general formula (I) to A (H) n (where A is a residue of an azo compound having the same meaning as in general formula (I), H is a hydrogen atom, n is 1 The composite pigment according to any one of claims 1 to 4, which is obtained by producing an azo compound represented by the formula:
A (E) n ... General formula (I)
However, in the said general formula (I), A is a residue of an azo compound, this residue A couple | bonds with n E group with an at least 1 hetero atom, and this hetero atom is N and O. Each of which is a part of the residue A, and each E group is independently —C (═O) —O—R ¹⁷ (wherein R ¹⁷ has 4 to 10 carbon atoms) Represents a substituted or unsubstituted alkyl group, alkenyl group, alkynyl group, cycloalkyl group, cycloalkenyl group, or aralkyl group). n is an integer of 1-10.   When producing a gallium phthalocyanine compound represented by the general formula (A) by reacting either a halogenated gallium phthalocyanine or a hydroxygallium phthalocyanine with a carboxylic acid compound, A (H) n (where A is It is a residue of an azo compound, H is a hydrogen atom, and n is an integer of 1 to 10. This is obtained by the presence of an azo compound represented by any one of claims 1 to 4. Composite pigment. From an azo compound represented by the following general formula (I) to A (H) n (where A is a residue of the azo compound as defined in general formula (I) by at least one of a chemical method and a thermal method. Yes, H is a hydrogen atom, and n is an integer of 1 to 10.) When an azo compound represented by the formula (A) is produced, the gallium phthalocyanine compound represented by the general formula (A) is present. The composite pigment according to any one of claims 1 to 4.
A (E) n ... General formula (I)
However, in the said general formula (I), A is a residue of an azo compound, this residue A couple | bonds with n E group with an at least 1 hetero atom, and this hetero atom is N and O. Each of which is a part of the residue A, and each E group is independently —C (═O) —O—R ¹⁷ (wherein R ¹⁷ has 4 to 10 carbon atoms) Represents a substituted or unsubstituted alkyl group, alkenyl group, alkynyl group, cycloalkyl group, cycloalkenyl group, or aralkyl group). n is an integer of 1-10.   Gallium phthalocyanine compound represented by formula (A) and A (H) n (where A is a residue of an azo compound, H is a hydrogen atom, and n is an integer of 1 to 10. The composite pigment according to any one of claims 1 to 7, which is obtained by simultaneously performing a composite treatment with an azo compound represented by the formula:   An electrophotographic photosensitive member comprising a support and at least a photosensitive layer on the support, wherein the photosensitive layer contains the composite pigment according to any one of claims 1 to 8. An electrophotographic photosensitive member; an electrostatic latent image forming unit that forms an electrostatic latent image on the electrophotographic photosensitive member; and a developing unit that develops the electrostatic latent image with toner to form a visible image. An image forming apparatus having at least transfer means for transferring the visible image to a recording medium,
The image forming apparatus according to claim 9, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to claim 9.