JP2007079493A - Hydroxygallium phthalocyanine mixture pigment, method for manufacturing the same, electrophotographic photoreceptor, electrophotographic device, and process cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a charge generating material that can impart preferable electrophotographic characteristics based on high photosensitivity intrinsic to a hydroxygallium phthalocyanine pigment to an electrophotographic photoreceptor when the material is used as the structural material of the photoreceptor, that has excellent dispersibility in a binder resin and that is effective for suppressing a picture quality defect such as fogging, and to provide a method for manufacturing the charge generating material. <P>SOLUTION: A hydroxygallium phthalocyanine mixture pigment is provided, which is the mixture pigment of a hydroxygallium phthalocyanine pigment and an electron transport pigment to be used as the structural material of an electrophotographic photoreceptor. The pigment is obtained by a wet pulverization process of a mixture containing a hydroxygallium phthalocyanine crystal, an electron transport pigment and a predetermined solvent. The X-ray diffraction pattern using CuKα characteristic X-rays shows diffraction peaks at 7.5°, 9.9°, 12.5°, 16.3°, 18.6°, 25.1° and 28.3° Bragg angles (2θ±0.2°). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hydroxygallium phthalocyanine mixed pigment used as a constituent material of an electrophotographic photosensitive member, a method for producing the same, and an electrophotographic photosensitive member, an electrophotographic apparatus, and a process cartridge using the hydroxygallium phthalocyanine mixed pigment.

  In recent years, the development of electrophotographic technology has been remarkable, and electrophotographic image formation using laser light or LED as a light source has the advantages of high speed and high image quality, and is widely used in the fields of copiers and optical printers. Yes. The electrophotographic photoreceptor used in the electrophotographic apparatus (hereinafter, simply referred to as “photoreceptor” in some cases) is less expensive and more manufacturable and disposable than an inorganic photoreceptor using a conventional inorganic photoconductive material. Organic photoreceptors using organic photoconductive materials having excellent advantages are becoming mainstream. Among them, the functionally separated organic photoreceptor in which a charge generation layer that generates charges upon exposure and a charge transport layer that transports charges is laminated is excellent in terms of electrophotographic characteristics, and various proposals have been made. It has become.

  Among them, in recent years, phthalocyanine compounds useful as electronic materials such as optical recording materials and photoelectric conversion materials have been widely used as charge generation materials in photoreceptors.

In general, it is known that phthalocyanine compounds are divided into several crystal forms depending on the production method or treatment method, and that the photoelectric conversion characteristics of the phthalocyanine compounds are greatly affected if the crystal forms are different. With regard to the crystal form of the phthalocyanine compound, for example, when a metal-free phthalocyanine crystal is seen, α-type, β-type, π-type, γ-type, X-type and other crystal types are known. Furthermore, regarding the gallium phthalocyanine crystal, many reports have been made on its crystal type and electrophotographic characteristics. The Bragg angle (2θ ± 0.2 °) with respect to the CuKα characteristic X-ray is 7.5 °, 9.9 °. An extremely sensitive hydroxygallium phthalocyanine having a diffraction peak at 12.5 °, 16.3 °, 18.6 °, 25.1 °, and 28.3 ° and a photoreceptor using the same have photosensitivity, It has been reported that it has excellent repeatability and environmental stability (see, for example, Patent Documents 1 and 2 and Non-Patent Document 1).

  On the other hand, along with the development of the electrophotographic technology described above, downsizing and energy saving of the apparatus are being promoted to reduce the environmental load. For example, as a charging method, a contact charging method with a small amount of ozone generation and a high charging efficiency is becoming mainstream instead of the corotron method. Also, to reduce the size of the device, an erase-less electrophotographic device that performs the next charging without discharging the photoconductor after charging, exposure, development, and transfer without providing an erase device for discharging is also adopted. It is being done.

  However, when the contact charging method is adopted in an erasureless electrophotographic apparatus and images are continuously formed by the reversal development method, two cycles are required due to the effect of photomemory characteristic of the hydroxygallium phthalocyanine pigment having high photosensitivity characteristics. If the sensitivity of the exposed part of the eye is higher than that of the non-exposed part, and an image in which a thick character part or solid part and halftone are mixed is output as an image to be printed, the exposed part of the first cycle is displayed in the halftone image part. When the overlaps occur, the density of the exposed portion in the first cycle is increased, so that a positive ghost is likely to occur. The generation of this positive ghost becomes more prominent when the thickness of the charge generation layer is increased in order to increase the sensitivity of the function-separated type photoreceptor. In addition, due to the recent downsizing of electrophotographic devices and higher process speeds, and the increasing demand for speeding up of small tandem full-color electrophotographic devices, image quality degradation due to positive ghosts is the most important issue in terms of quality. It is one and further improvement is desired.

Thus, some studies have been made to achieve both improvement in the sensitivity of the photoreceptor and suppression of positive ghost. For example, Patent Document 3 discloses a technique in which a charge generation layer of a photoreceptor contains phthalocyanine and an organic electron acceptor. Patent Document 4 discloses a technique of adding an organic electron acceptor when phthalocyanine is pigmented. Patent Document 5 discloses a technique of adding an n-type charge transport pigment when phthalocyanine is pigmented.
Japanese Patent Laid-Open No. 5-263007 JP 7-53892 A JP 7-104495 A JP 2001-040237 A JP-A-5-333575 Journal of Imaging Science and Technology, Vol. 40, no. 3, May / June, 249 (1996)

  However, when a photoconductor is produced by the techniques described in Patent Documents 3 and 4, the organic electron acceptor is detached from the surface of the phthalocyanine pigment during the dispersion treatment when preparing the coating solution, or the organic electron acceptor is eluted during the washing of the pigment. End up. For this reason, it is not always easy to sufficiently impart the desired function to the photoconductor by this method, and even if the obtained photoconductor is applied to an eraseless electrophotographic apparatus, the occurrence of positive ghosts can be sufficiently suppressed. There are many things that cannot be done. Further, in such a photoreceptor, if an undercoat layer containing metal oxide fine particles is provided between the conductive support and the photosensitive layer in order to increase the leakage resistance of the photoreceptor, the occurrence of ghost becomes significant. There is a tendency.

  In the case of the technique described in Patent Document 5, although effective in terms of suppressing positive ghosts, the particle diameter tends to be non-uniform due to the generation of coarse particles in the pigmentation process and the incorporation of crystal aggregates. The primary particle diameter tends to be large. Therefore, when the pigment obtained by this method is used as a constituent material of an electrophotographic photoreceptor, variations in characteristics such as sensitivity, chargeability, and dark decay rate, or a decrease in dispersibility in the binder resin is likely to occur. Another problem is that image defects such as fogging, black spots, and white spots occur.

  The present invention has been made in view of the above-described problems of the prior art, and the object thereof is based on the high light sensitivity inherently possessed by hydroxygallium phthalocyanine pigments when used as a constituent material of an electrophotographic photoreceptor. It is an object to provide a charge generating material that can impart good electrophotographic characteristics, has excellent dispersibility in a binder resin, and is effective in suppressing image quality defects such as positive ghost and fogging, and a method for producing the same. . Another object of the present invention is to provide an electrophotographic photosensitive member using the charge generating material as a constituent material, and an electrophotographic apparatus and a process cartridge including the electrophotographic photosensitive member.

  As a result of diligent studies to achieve the above object, the inventors of the present invention obtained a mixture containing a hydroxygallium phthalocyanine crystal, an electron transporting pigment, and a predetermined solvent so that the obtained mixed pigment exhibits a specific X-ray diffraction pattern. It has been found that an electron transporting pigment can be contained in the obtained hydroxygallium phthalocyanine pigment and refined by changing the crystal form of the hydroxygallium phthalocyanine crystal by wet grinding. And it discovered that the said subject was solved by using the hydroxygallium phthalocyanine mixed pigment obtained in that way as a constituent material of an electrophotographic photoreceptor, and came to complete this invention.

  That is, the hydroxygallium phthalocyanine mixed pigment of the present invention is a mixed pigment of a hydroxygallium phthalocyanine pigment and an electron transporting pigment used as a constituent material of an electrophotographic photoreceptor, and comprises a hydroxygallium phthalocyanine crystal and an electron transporting pigment. In an X-ray diffraction pattern obtained by wet-grinding a mixture containing a predetermined solvent and using CuKα characteristic X-rays, Bragg angles (2θ ± 0.2 °) 7.5 °, 9.9 ° It has diffraction peaks at 12.5 °, 16.3 °, 18.6 °, 25.1 ° and 28.3 °.

  According to the present invention, a mixture containing a hydroxygallium phthalocyanine crystal, an electron transporting pigment, and a predetermined solvent is subjected to a wet pulverization treatment so that the X-ray diffraction pattern of the obtained mixed pigment satisfies the above-mentioned conditions. While converting the hydroxygallium phthalocyanine pigment into a highly sensitive crystal form, the electron-transporting pigment can be incorporated into the hydroxygallium phthalocyanine pigment and refined. Therefore, by using the hydroxygallium phthalocyanine mixed pigment of the present invention as a constituent material of an electrophotographic photoreceptor, it is possible to impart sufficient charging characteristics, photosensitivity and low dark attenuation to the electrophotographic photoreceptor, positive ghost, Image quality defects such as fog can be sufficiently prevented.

  The reason why the above effect is obtained by the hydroxygallium phthalocyanine mixed pigment of the present invention is not necessarily clear, but the present inventors speculate as follows. That is, when the hydroxygallium phthalocyanine mixed pigment of the present invention is used as a constituent material of an electrophotographic photoreceptor, the electron transporting pigment acts extremely effectively at the interface between the hydroxygallium phthalocyanine pigment and the binder resin, and the charge at the interface is charged. It is considered that the injection property of (electrons) is improved and charge traps existing on the pigment surface are reduced. The action of the electron transporting pigment can give the electrophotographic photosensitive member a higher level of photosensitivity and durability for stably obtaining a clear copy image even after repeated use. It is considered that the occurrence of positive ghost, which is considered to be caused by the electron residual property of the hydroxygallium phthalocyanine mixed pigment, can be prevented. Furthermore, the hydroxygallium phthalocyanine mixed pigment of the present invention has excellent dispersibility because it is refined when the electron transporting pigment is incorporated into the hydroxygallium phthalocyanine pigment. Therefore, it is possible to sufficiently suppress the generation of coarse particles and aggregates during the preparation of coating solutions containing hydroxygallium phthalocyanine mixed pigments or during the manufacture of electrophotographic photoreceptors, and prevent image quality defects such as fogging and black / white spots. It is thought that it can be done.

  The hydroxygallium phthalocyanine mixed pigment of the present invention preferably has a maximum peak wavelength in the range of 810 to 839 nm in the spectral absorption spectrum in the wavelength range of 600 to 900 nm.

  In general, phthalocyanine pigments have the property that the interaction between phthalocyanine molecules changes depending on the molecular arrangement in the crystal, and as a result, the state of the molecular arrangement is reflected in the spectral absorption spectrum. When the hydroxygallium phthalocyanine mixed pigment of the present invention has a maximum peak wavelength in the range of 810 to 839 nm, the mixed pigment exhibits further excellent dispersibility in the photosensitive layer. It becomes possible to further improve the characteristics and the dark attenuation characteristics, and it is possible to obtain stable image quality over a long period of time without causing image quality defects such as ghosts and fogging.

  In the spectral absorption spectrum in the wavelength range of 600 to 900 nm, a conventional V-type hydroxygallium phthalocyanine pigment having a peak wavelength in the range of 840 to 870 nm (in the X-ray diffraction pattern using CuKα characteristic X-rays, the Bragg angle (2θ ± 0.2 °) hydroxygallium phthalocyanine having diffraction peaks at 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6 °, 25.1 ° and 28.3 ° When the photosensitive layer contains a hydroxygallium phthalocyanine pigment having a maximum peak wavelength in the range exceeding 839 nm and an electron transporting pigment as in (Pigment), the dark current tends to increase or fog easily occurs. . This is because, since the absorption wavelength is shifted to the long wavelength side, the hydroxygallium phthalocyanine pigment is in a state where the interaction between molecules is relatively strong, and the electric charge easily flows through the crystal. The present inventors speculate.

  In addition, a hydroxygallium phthalocyanine pigment having a maximum peak wavelength in a range of less than 810 nm (a peak exists in a range of 810 to 839 nm or a range of more than 839 nm, but a peak having a higher absorbance exists in a range of less than 810 nm. And an electron transporting pigment are contained in the photosensitive layer, the sensitivity tends to decrease and the residual potential increases. This is because the absorption wavelength is shifted to the short wavelength side, so that the hydroxygallium phthalocyanine pigment is in a state where the interaction between molecules is relatively weak, and the charge is difficult to flow through the crystal. The present inventors speculate.

  Therefore, when the hydroxygallium phthalocyanine mixed pigment of the present invention has a maximum peak wavelength in the range of 810 to 839 nm, the interaction between the molecules of the hydroxygallium phthalocyanine pigment and the electron transporting pigment in the photosensitive layer containing the mixed pigment. The present inventors consider that the degree of the above is a more favorable state for the movement of electric charge, which is one of the factors for obtaining the above effect.

In the hydroxygallium phthalocyanine mixed pigment of the present invention, the addition amount of the electron transporting pigment is preferably 0.001 to 0.1 parts by mass with respect to 1 part by mass of the hydroxygallium phthalocyanine crystal. If the amount of the electron transporting pigment added is less than 0.001 part by mass, image defects such as positive ghost tend to occur. On the other hand, if the amount exceeds 0.1 part by mass, the dispersion of the hydroxygallium phthalocyanine mixed pigment is likely to occur. It tends to cause problems such as image quality defects such as fogging and deterioration of charging characteristics, photosensitivity, and dark decay characteristics of the photoreceptor, and the hydroxygallium phthalocyanine mixed pigment of the present invention. The production method is a method of producing a mixed pigment of a hydroxygallium phthalocyanine pigment and an electron transporting pigment used as a constituent material of an electrophotographic photoreceptor, and the obtained mixed pigment is an X using CuKα characteristic X-rays. Bragg angles (2θ ± 0.2 °) 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6 °, 25.1 ° and 28 in the line diffraction pattern So as to have a diffraction peak at 3 °, characterized hydroxy gallium phthalocyanine crystal, an electron transporting pigment, further comprising a wet milling process the mixture to wet pulverization process including a predetermined solvent.

  According to the above production method, by wet-grinding a mixture containing a hydroxygallium phthalocyanine crystal, an electron transporting pigment, and a predetermined solvent so that the X-ray diffraction pattern of the obtained mixed pigment satisfies the specific condition, While converting the crystal form of the hydroxygallium phthalocyanine pigment, it is possible to incorporate the electron transporting pigment into the pigment and make it finer. Therefore, the hydroxygallium phthalocyanine mixed pigment of the present invention having the above-described excellent characteristics is effectively used. Can be obtained.

  In the above production method, the crude gallium phthalocyanine is subjected to an acid pasting treatment before the wet pulverization treatment step, so that Bragg angles (2θ ± 0.2 °) of 6.9 °, 13.2 to 14.2 °, 16. Obtain hydroxygallium phthalocyanine crystals having diffraction peaks at 5 °, 26.0 ° and 26.4 °, or 7.0 °, 13.4 °, 16.6 °, 26.0 ° and 26.7 °. It is preferable to further include an acid pasting treatment step, and the hydroxygallium phthalocyanine crystal obtained by the acid pasting treatment step is preferably subjected to the wet pulverization treatment step.

  By subjecting the hydroxygallium phthalocyanine crystal obtained by the acid pasting treatment step to the wet grinding treatment step, the treatment time in the wet grinding treatment step can be shortened, and the hydroxygallium phthalocyanine mixed pigment of the present invention can be shortened. Manufacturing efficiency can be improved.

  The reason why such an effect can be obtained is that the crystal structure of the hydroxygallium phthalocyanine crystal obtained by the acid pasting process is superior in performance as a photoconductive material for an electrophotographic photoreceptor by the wet grinding process. In a structure that is more suitable for conversion into a crystal form that expresses the above, and a structure in which coarse particles or aggregates are less likely to be formed even when an electron transporting pigment is present in the wet pulverization process. It is thought that there is.

  The electrophotographic photosensitive member of the present invention comprises a conductive support and a photosensitive layer provided on the conductive support and containing the hydroxygallium phthalocyanine mixed pigment of the present invention. And

  According to the electrophotographic photoreceptor of the present invention, by incorporating the hydroxygallium phthalocyanine mixed pigment of the present invention into the photosensitive layer, charging characteristics, photosensitivity and low dark decay characteristics can be sufficiently improved, and fog and It is possible to obtain stable image quality over a long period without causing image quality defects such as positive ghost.

  The electrophotographic photoreceptor of the present invention may further include an undercoat layer containing metal oxide fine particles between the conductive support and the photosensitive layer.

  The electrophotographic photosensitive member of the present invention may have a multilayer structure in which the photosensitive layer includes a charge generation layer and a charge transport layer, and the charge generation layer contains the hydroxygallium phthalocyanine mixed pigment of the present invention. Good.

  The electrophotographic apparatus of the present invention includes the electrophotographic photosensitive member of the present invention, a charging unit that charges the electrophotographic photosensitive member, an exposure unit that forms an electrostatic latent image on the charged electrophotographic photosensitive member, Development means for developing the electrostatic latent image formed on the electrophotographic photosensitive member with toner to form a toner image, and transfer means for transferring the toner image from the electrophotographic photosensitive member to a transfer medium. Features.

  By providing the electrophotographic photosensitive member of the present invention, such an electrophotographic apparatus achieves sufficient charging characteristics, light sensitivity, and low dark decay characteristics, and is stable for a long time without causing image quality defects such as positive ghost and fogging. Image quality can be obtained.

  In particular, the image forming apparatus of the present invention includes a charging member to which a voltage is applied so that the charging means is in contact with the electrophotographic photosensitive member, and after performing charging, exposure, development, and transfer, electrophotography This is effective in preventing the occurrence of positive ghost in an eraseless electrophotographic apparatus that performs the next charging without discharging the photosensitive member.

  The process cartridge of the present invention comprises a toner image obtained by developing the electrophotographic photosensitive member of the present invention, a charging means for charging the electrophotographic photosensitive member, and an electrostatic latent image formed on the electrophotographic photosensitive member with toner. And at least one selected from the group consisting of a cleaning unit for removing toner remaining on the electrophotographic photosensitive member.

  By providing the electrophotographic photosensitive member of the present invention, such a process cartridge achieves sufficient charging characteristics, light sensitivity, and low dark decay characteristics, and stable images over a long period without causing image quality defects such as positive ghosts and fogging. It is possible to obtain quality.

  According to the present invention, when used as a constituent material of an electrophotographic photosensitive member, sufficient charging characteristics, photosensitivity and low dark attenuation can be imparted to the electrophotographic photosensitive member, and image quality such as positive ghost and fogging can be imparted. It is possible to provide a hydroxygallium phthalocyanine mixed pigment effective for preventing defects and a method for producing the same. In addition, according to the present invention, electrophotography having sufficient charging characteristics, light sensitivity, and low dark decay characteristics, and capable of obtaining stable image quality over a long period of time without causing image quality defects such as positive ghost and fogging. A photoconductor, a process cartridge and an electrophotographic apparatus including the electrophotographic photoconductor can be provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as the case may be. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

(Hydroxygallium phthalocyanine mixed pigment and method for producing the same)
The hydroxygallium phthalocyanine mixed pigment of the present invention is a mixed pigment of a hydroxygallium phthalocyanine pigment and an electron transporting pigment, and wet pulverizes a mixture containing a hydroxygallium phthalocyanine crystal, an electron transporting pigment and a predetermined solvent. And X-ray diffraction pattern using CuKα characteristic X-rays, Bragg angles (2θ ± 0.2 °) 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18. It has diffraction peaks at 6 °, 25.1 ° and 28.3 °.

  Further, in the method for producing a hydroxygallium phthalocyanine mixed pigment of the present invention, the resulting mixed pigment has an Bragg angle (2θ ± 0.2 °) of 7.5 °, 9 in an X-ray diffraction pattern using CuKα characteristic X-ray. A hydroxygallium phthalocyanine crystal, an electron transporting pigment, and a predetermined amount so as to have diffraction peaks at .9 °, 12.5 °, 16.3 °, 18.6 °, 25.1 °, and 28.3 °. A wet pulverization treatment step of wet pulverizing the mixture containing the solvent.

  The hydroxygallium phthalocyanine pigment used in the present invention is preferably a chlorogallium phthalocyanine or gallium phthalocyanine dimer coarse crystal refined by acid pasting or pulverization, etc., and X-rays using CuKα characteristic X-rays In the diffraction spectrum, the Bragg angle (2θ ± 0.2 °) 6.9 °, 13.2-14.2 °, 16.5 °, 26.0 ° and 26.4 °, or 7.0 °, It is preferable to use a hydroxygallium phthalocyanine crystal having diffraction peaks at 13.4 °, 16.6 °, 26.0 ° and 26.7 ° (hereinafter referred to as “type I hydroxygallium phthalocyanine crystal”). Type I hydroxygallium phthalocyanine crystal can be obtained by a conventionally known method. An example is shown below.

  First, a method of reacting o-phthalodinitrile or 1,3-diiminoisoindoline and gallium trichloride in a predetermined solvent (type I chlorogallium phthalocyanine method); o-phthalodinitrile, alkoxygallium and ethylene glycol Crude gallium phthalocyanine is produced by a method of synthesizing a phthalocyanine dimer (phthalocyanine dimer) by reacting with heating in a predetermined solvent (phthalocyanine dimer method). As the solvent in the above reaction, α-chloronaphthalene, β-chloronaphthalene, α-methylnaphthalene, methoxynaphthalene, dimethylaminoethanol, diphenylethane, ethylene glycol, dialkyl ether, quinoline, sulfolane, dichlorobenzene, dimethylformamide, dimethyl It is preferable to use an inert and high boiling point solvent such as sulfoxide or dimethylsulfamide.

  Next, the crude gallium phthalocyanine obtained in the above step is subjected to an acid pasting process, whereby the crude gallium phthalocyanine is made into fine particles and converted into I-type hydroxygallium phthalocyanine. Here, the acid pasting treatment is, specifically, a solution in which crude gallium phthalocyanine is dissolved in an acid such as sulfuric acid or an acid salt such as a sulfate is poured into an aqueous alkaline solution, water or ice water, Recrystallized. As the acid used for the acid pasting treatment, sulfuric acid is preferable, and sulfuric acid having a concentration of 70 to 100% (particularly preferably 95 to 100%) is more preferable.

  The electron transporting pigment used in the present invention may be either an organic pigment or an inorganic pigment.

  Examples of the organic pigment having an electron transport property include an electron transport polycyclic quinone pigment, an electron transport perylene pigment, an electron transport phthalocyanine pigment, an electron transport azo pigment, an electron transport indigo pigment, and an electron transport. Quinacridone pigments and the like. Among these, an electron transporting polycyclic quinone pigment, an electron transporting perylene pigment, an electron transporting phthalocyanine pigment, and an electron transporting azo pigment are preferable.

  Examples of the electron transporting polycyclic quinone pigment include polycyclic quinone pigments such as brominated anthanthrone. Specific examples of the electron transporting polycyclic quinone pigment are shown in Table 1 below.

  Examples of the electron transporting perylene pigment include perylene pigments and bisbenzimidazole perylene pigments. Specific examples of the electron transporting perylene pigment are shown in Tables 2 and 3 below.

  Examples of the electron-transporting phthalocyanine pigment include phthalocyanine pigments having an electron-withdrawing substituent such as a cyano group, a nitro group, a nitroso group, and a halogen atom. Specific examples of the electron transporting phthalocyanine pigment are shown in Table 5 below.

  Examples of the electron transporting azo pigment include bisazo pigments having an electron-withdrawing substituent such as a cyano group, a nitro group, a nitroso group, and a halogen atom. Specific examples of the electron transporting azo pigment are shown in Tables 6 to 11 below.

  On the other hand, examples of the inorganic pigment having an electron transporting property include zinc oxide and titanium oxide.

  In the present invention, one of these electron transport pigments may be used alone, or two or more may be used in combination. Further, the electron transporting pigment may be appropriately synthesized or may be a commercially available product.

  In the present invention, among the above electron transporting pigments, an electron transporting polycyclic quinone pigment, an electron transporting perylene pigment, an electron transporting phthalocyanine pigment, and an electron transporting azo pigment are high in electron mobility. Is preferably used.

  The amount of the electron transporting pigment added in the wet pulverization treatment is preferably 0.001 to 0.1 parts by mass with respect to 1 part by mass of the hydroxygallium phthalocyanine crystal. If the amount of the electron transporting pigment added is less than 0.001 part by mass, image defects such as positive ghost tend to occur. On the other hand, if the amount exceeds 0.1 part by mass, the dispersion of the hydroxygallium phthalocyanine mixed pigment is likely to occur. Tend to cause problems such as image quality defects such as fogging, and deterioration of charging characteristics, photosensitivity, and dark attenuation characteristics of the photoreceptor.

  In the wet pulverization treatment step according to the present invention, the obtained mixed pigment has an Bragg angle (2θ ± 0.2 °) of 7.5 °, 9.9 °, in an X-ray diffraction pattern using CuKα characteristic X-rays. A mixture containing a hydroxygallium phthalocyanine crystal, an electron transporting pigment, and a predetermined solvent so as to have diffraction peaks at 12.5 °, 16.3 °, 18.6 °, 25.1 ° and 28.3 ° Is subjected to wet pulverization.

  Examples of the solvent used in the wet grinding treatment include amides such as N, N-dimethylformamide, N, N-dimethylacetamide, and N-methylpyrrolidone; esters such as ethyl acetate, n-butyl acetate, and iso-amyl acetate. Ketones such as acetone, methyl ethyl ketone, and methyl iso-butyl ketone; dimethyl sulfoxide and the like. The amount of these solvents used is preferably 1 to 200 parts by weight, more preferably 1 to 100 parts by weight, and 5 to 50 parts by weight with respect to 1 part by weight of the hydroxygallium phthalocyanine pigment. Is more preferably 10 to 30 parts by mass.

  As an apparatus used for the wet pulverization treatment, an apparatus using a media such as a vibration mill, an automatic mortar, a sand mill, a dyno mill, a coball mill, an attritor, a planetary ball mill, or a ball mill as a dispersion medium can be used.

  The medium used is preferably a spherical medium, and its outer diameter is preferably 0.1 to 3.0 mm, more preferably 0.2 to 2.5 mm. When the outer shape of the media is larger than 3.0 mm, the pulverization efficiency is lowered, so that the particle diameter does not become small and aggregates tend to be easily generated. Moreover, when the outer diameter of the medium is smaller than 0.1 mm, it tends to be difficult to separate the medium and the hydroxygallium phthalocyanine mixed pigment. In addition, when the media is not spherical, but in other shapes such as a columnar shape or an indeterminate shape, the grinding efficiency decreases, the media is easily worn by grinding, and the abrasion powder becomes an impurity, resulting in the characteristics of the hydroxygallium phthalocyanine mixed pigment. There is a tendency to be easily deteriorated.

  Further, the material of the media is not particularly limited, but those that are less likely to cause image quality defects even when mixed in a hydroxygallium phthalocyanine pigment are preferable, and glass, zirconia, alumina, meno and the like are preferable.

  Although the usage-amount of the said media changes also with apparatuses to be used, it is preferable that it is 50 mass parts or more with respect to 1 mass part of hydroxygallium phthalocyanine pigments, and it is more preferable that it is 55-100 mass parts. Also, as the media outer diameter decreases, the media density in the device increases even with the same mass (use amount), and the viscosity of the mixed solution increases and the pulverization efficiency changes. It is desirable to perform wet processing at an optimal mixing ratio by controlling the amount of media used and the amount of solvent used.

  In addition, the material of the container of the wet pulverization processing apparatus (the container for storing the mixture to be processed and the medium) is not particularly limited, but it is less likely to cause image quality defects when mixed in the hydroxygallium phthalocyanine pigment. Glass, zirconia, alumina, meno, polypropylene, polytetrafluoroethylene, polyphenylene sulfide, and the like are preferable. Alternatively, the inner surface of a metal container such as iron or stainless steel may be lined with glass, polypropylene, polytetrafluoroethylene, polyphenylene sulfide, or the like.

  Conditions such as treatment time and treatment temperature in the wet pulverization treatment process are as follows: Bragg angle (2θ ± 0.2 °) 7.5 ° in the X-ray diffraction pattern in which the obtained mixed pigment uses CuKα characteristic X-rays; Although it is not particularly limited as long as it has diffraction peaks at 9 °, 12.5 °, 16.3 °, 18.6 °, 25.1 ° and 28.3 °, the treatment time is usually in the range of 5 to 500 hours, Preferably it is the range of 7 to 300 hours. When the treatment time is less than 5 hours, the crystal conversion is not completed, and the electrophotographic characteristics are deteriorated, and particularly, the sensitivity is apt to be insufficient. Further, when the processing time exceeds 500 hours, sensitivity tends to decrease due to the influence of pulverization stress, productivity decreases, and media wear powder tends to be mixed.

  Moreover, the temperature of the wet pulverization treatment is preferably 0 to 100 ° C, more preferably 5 to 80 ° C, and particularly preferably 10 to 50 ° C. When the temperature is low, the rate of crystal transition tends to be slow, and when the temperature is too high, the solubility of the hydroxygallium phthalocyanine pigment tends to be high and crystal growth tends to be difficult. is there.

  In addition, about the processing time, the progress degree of a process can be monitored by measuring a spectral absorption spectrum about the to-be-processed object after predetermined time progress from a wet grinding process start. More specifically, the wet pulverization treatment is continued until the spectral absorption spectrum in the wavelength range of 600 to 900 nm measured for the object to be processed has a maximum peak wavelength in the range of 810 to 839 nm. As a result, the wet pulverization process can be completed in a state where the mixed pigment particles are uniformly atomized. Furthermore, when performing the repeated wet pulverization processing of a plurality of lots, it is possible to suppress the quality variation between lots.

  In the method for producing a hydroxygallium phthalocyanine mixed pigment of the present invention, it is preferable to further perform washing with a solvent and / or heat drying after the wet pulverization treatment. The impurity concentration of the hydroxygallium phthalocyanine mixed pigment can be controlled by such washing with a solvent or heat drying.

  When the impurity concentration is controlled by washing with a solvent, examples of the solvent used include water, ethanol, methanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, and ethyl acetate. Organic solvents such as n-butyl acetate, dioxane, tetrahydrofuran, methylene chloride, chloroform, benzene, toluene, xylene, chlorobenzene, dimethylformaldehyde, dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, and mixed solvents thereof, And supercritical fluids such as carbon dioxide and nitrogen. As a cleaning method, a known method can be used without any particular limitation. From the viewpoint of cleaning efficiency, a ceramic filter, an ultrasonic cleaner, a Soxhlet extractor, a micromixer having a channel diameter of 10 to 1000 μm, or the like The cleaning method using the is effective.

  Moreover, when controlling an impurity density | concentration by heat drying, as temperature of heat drying, Preferably it is 50-200 degreeC, More preferably, it is 100-180 degreeC. When the heating temperature is less than 50 ° C., it tends to be difficult to completely remove impurities affecting various properties of the hydroxygallium phthalocyanine mixed pigment. When the heating temperature exceeds 200 ° C., the sensitivity of the hydroxygallium phthalocyanine mixed pigment. Tends to decrease significantly. Moreover, it is preferable to adjust suitably the processing time of heat drying according to the weight of the hydroxygallium phthalocyanine mixed pigment to process.

  In order to efficiently remove impurities of the hydroxygallium phthalocyanine mixed pigment by heat drying, it is preferable to heat and dry the hydroxygallium phthalocyanine mixed pigment under reduced pressure. When performing heat drying under reduced pressure, there is an advantage that the temperature of heat drying can be made lower than when performing under normal pressure. The temperature of the heat drying at this time is preferably in the range of 50 ° C. to 200 ° C., although it depends on the degree of reduced pressure.

  Moreover, it is preferable to perform heat drying in presence of an inert gas. Examples of the inert gas include helium, neon, argon, and the like of group 0 of the periodic table, and these can be used alone or in admixture of two or more. By performing the heat drying in the presence of these inert gases, there is an advantage that the hydroxygallium phthalocyanine mixed pigment is prevented from being oxidized by oxygen in the air and heat drying at a high temperature is possible. Moreover, it is also preferable to perform heat drying in the state which interrupted light. Thereby, it is possible to prevent the hydroxygallium phthalocyanine mixed pigment from being light-fatigued during heat drying.

(Electrophotographic photoreceptor)
FIG. 1A is a schematic cross-sectional view showing a first embodiment of the electrophotographic photosensitive member of the present invention. An electrophotographic photoreceptor 100 shown in FIG. 1A is a laminated type in which functions are separated into a layer containing a charge generation material (charge generation layer 1) and a layer containing a charge transport material (charge transport layer 2). It has a photosensitive layer 6 and has a structure in which a charge generation layer 1 and a charge transport layer 2 are sequentially laminated on a conductive support 3. The hydroxygallium phthalocyanine mixed pigment of the present invention is contained in the charge generation layer 1 as a charge generation material.

  Hereinafter, each component of the electrophotographic photoreceptor 100 will be described in detail.

  Examples of the conductive support 3 include those made of metal such as aluminum, copper, iron, zinc and nickel; on a substrate such as a polymer sheet, paper, plastic and glass, aluminum, copper, gold, silver and platinum Conductive treatment by depositing a metal such as palladium, titanium, nickel-chromium, stainless steel, copper-indium; Conductive treatment by depositing a conductive metal compound such as indium oxide or tin oxide on the substrate. Conductive treatment by laminating a metal foil on the substrate; carbon black, indium oxide, tin oxide-antimony oxide powder, metal powder, copper iodide, etc. are dispersed in a binder resin and The thing etc. which carried out the conductive process by apply | coating to are mentioned. The shape of the conductive support 3 may be any of a drum shape, a sheet shape, and a plate shape.

  When a metal pipe substrate is used as the conductive support 3, the surface thereof may remain as it is, but in advance, mirror cutting, etching, anodizing, rough cutting, centerless grinding, sand blasting, wet honing, coloring treatment It is preferable to roughen the substrate surface by a surface treatment such as In this way, by roughening the surface of the substrate, it is possible to prevent grain-like density spots due to interference light in the photoconductor that may occur when a coherent light source such as a laser beam is used.

  The charge generation layer 1 contains the hydroxygallium phthalocyanine mixed pigment of the present invention as a charge generation material and a binder resin.

  Examples of the binder resin include polycarbonate, polystyrene, polysulfone, polyester, polyimide, polyester carbonate, polyvinyl butyral, methacrylic acid ester polymer, vinyl acetate homopolymer or copolymer, cellulose ester, cellulose ether, polybutadiene, polyurethane, phenoxy. Examples thereof include resins, epoxy resins, silicone resins, fluororesins, and partially crosslinked cured products thereof. One of these can be used alone, or two or more can be used in combination.

  The compounding ratio (weight ratio) of the hydroxygallium phthalocyanine mixed pigment of the present invention and the binder resin in the charge generation layer 1 is preferably 40: 1 to 1: 4, more preferably 20: 1 to 1: 2. is there. When the blending amount of the hydroxygallium phthalocyanine mixed pigment of the present invention exceeds 40 times the blending amount of the binder resin, the dispersibility of the mixed pigment in the dispersion used in the electrophotographic photoreceptor manufacturing process becomes insufficient. On the other hand, if the blending amount of the binder resin is less than ¼, the sensitivity of the electrophotographic photosensitive member tends to be insufficient.

  The charge generation layer 1 may contain other charge generation materials other than the hydroxygallium phthalocyanine mixed pigment of the present invention. Here, as other charge generation materials used for the charge generation layer 1, azo pigments, perylene pigments, condensed aromatic pigments and the like can be used, but it is preferable to use metal-containing or metal-free phthalocyanines. Among them, it is particularly preferable to use a hydroxygallium phthalocyanine pigment, a chlorogallium phthalocyanine pigment, a dichlorotin phthalocyanine pigment, or an oxytitanyl phthalocyanine pigment. The amount of these other charge generation materials is preferably 50% by weight or less based on the total amount of substances contained in the charge generation layer.

  When another layer such as the charge transport layer 2 is further formed on the charge generation layer 1, the charge generation layer 1 is not dissolved or swollen by the solvent used in the coating solution. The combination of the binder resin of the charge generation layer 1 and the solvent of the coating solution applied onto the charge generation layer 1 is preferably selected as appropriate. The binder resin of the charge generation layer 1 and the binder resin of the charge transport layer 2, which will be described later, are preferably used in combination with ones whose refractive indices are close to each other. The difference is preferably 1 or less. When a binder resin having a similar refractive index is used in combination, light reflection at the interface between the charge generation layer 1 and the charge transport layer 2 is suppressed, and the interference fringe prevention effect tends to be improved.

  The charge generation layer 1 is obtained by adding the hydroxygallium phthalocyanine mixed pigment of the present invention and a binder resin to a predetermined solvent, a sand mill, a colloid mill, an attritor, a dyno mill, a jet mill, a coball mill, a roll mill, an ultrasonic disperser, a gorin homogenizer, The coating liquid obtained by mixing and dispersing using a microfluidizer, optimizer, milder, etc., blade coating method, Meyer bar coating method, spray coating method, dip coating method, bead coating method, air knife coating method It can be obtained by applying by a curtain coating method and drying. Here, as a solvent used for the coating liquid of the charge generation layer 1, specifically, methanol, ethanol, n-butanol, benzyl alcohol, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran , Methylene chloride, chloroform, toluene, xylene, chlorobenzene, dimethylformamide, dimethylacetamide, water, and the like. One of these may be used alone, or a mixture of two or more may be used. The film thickness of the charge generation layer 1 thus obtained is preferably 0.05 to 5 μm, more preferably 0.1 to 1 μm, from the viewpoint of obtaining good electrical characteristics and image quality. When the film thickness of the charge generation layer 1 is less than 0.05 μm, the sensitivity tends to decrease, and when the film thickness exceeds 5 μm, there is a tendency that adverse effects such as poor chargeability tend to occur.

  The charge transport layer 2 contains a charge transport material and a binder resin. The charge transport material used for the charge transport layer 2 can be used without particular limitation as long as it has a function of transporting charges. For example, oxadiazole derivatives such as 2,5-bis (p-diethylaminophenyl) -1,3,4-oxadiazole, 1,3,5-triphenyl-pyrazoline, 1- [pyridyl- (2)] Pyrazoline derivatives such as -3- (p-diethylaminostyryl) -5- (p-diethylaminostyryl) pyrazoline, triphenylamine, tri (P-methyl) phenylamine, N, N′-bis (3,4-dimethylphenyl) ) Aromatic tertiary amino compounds such as biphenyl-4-amine, dibenzylaniline, 9,9-dimethyl-N, N′-di (p-tolyl) fluorenon-2-amine, N, N′-diphenyl- Aromatic tertiary diamino compounds such as N, N′-bis (3-methylphenyl)-[1,1-biphenyl] -4,4′-diamine, 3- (4′dimethyla Nophenyl) -5,6-di- (4′-methoxyphenyl) -1,2,4-triazine, 1,2,4-triazine derivatives, 4-diethylaminobenzaldehyde-1,1-diphenylhydrazone, 4-diphenyl Hydrazone derivatives such as aminobenzaldehyde-1,1-diphenylhydrazone, [p- (diethylamino) phenyl] (1-naphthyl) phenylhydrazone, quinazoline derivatives such as 2-phenyl-4-styryl-quinazoline, 6-hydroxy-2, Benzofuran derivatives such as 3-di (p-methoxyphenyl) -benzofuran, α-stilbene derivatives such as p- (2,2-diphenylvinyl) -N, N′-diphenylaniline, enamine derivatives, N-ethylcarbazole, etc. Carbazole derivatives, poly-N-vinylcarbazole and Hole transport materials such as derivatives thereof, quinone compounds such as chloranil, bromoanil and anthraquinone, tetracyanoquinodimethane compounds, 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitro-9- Fluorenone compounds such as fluorenone, 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, 2,5-bis (4-naphthyl) -1,3 Oxadiazole compounds such as 4-oxadiazole, 2,5-bis (4-diethylaminophenyl) 1,3,4 oxadiazole, xanthone compounds, thiophene compounds, 3,3 ′, 5,5′tetra And electron transport materials such as diphenoquinone compounds such as -t-butyldiphenoquinone. Furthermore, as the charge transport material, a polymer having the basic structure of the compound exemplified above in the main chain or the side chain can be used. These charge transport materials can be used singly or in combination of two or more.

  As the binder resin used for the charge transport layer 2, a known resin can be used without any particular limitation, but a resin capable of forming an electrically insulating film is preferably used. For example, polycarbonate resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer, vinylidene chloride-acrylonitrile copolymer, vinyl chloride-acetic acid Vinyl copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, poly-N-carbazole, polyvinyl butyral, polyvinyl formal, polysulfone , Casein, gelatin, polyvinyl alcohol, ethyl cellulose, phenol resin, polyamide, carboxy-methyl cellulose, vinylidene chloride polymer wax, polyurea Emissions, and the like. These binder resins can be used alone or in combination of two or more. In particular, a polycarbonate resin, a polyester resin, a methacrylic resin, and an acrylic resin are preferably used because they are excellent in compatibility with a charge transporting material, solubility in a solvent, and strength.

  Further, the blending ratio (weight ratio) between the binder resin and the charge transport material can be arbitrarily set in consideration of a decrease in electrical characteristics and a decrease in film strength.

  Furthermore, the thickness of the charge transport layer 2 is preferably 5 to 50 μm, and more preferably 10 to 35 μm.

  As a solvent used for the coating liquid for forming the charge transport layer 2, a common organic solvent such as dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, toluene and the like can be used alone or in combination. As a method for applying the charge transport layer 2, a normal method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, or a curtain coating method can be used.

  FIG. 1B is a schematic cross-sectional view showing a second embodiment of the electrophotographic photosensitive member of the present invention. The electrophotographic photoreceptor 110 shown in FIG. 1B is similar to the electrophotographic photoreceptor 100 shown in FIG. 1A except that the undercoat layer 4 is provided between the conductive support 3 and the photosensitive layer 6. It has the same structure.

  The undercoat layer 4 has a function of preventing charge injection from the conductive support 3 to the photosensitive layer 6 when the photosensitive layer 6 is charged. Further, the undercoat layer 4 also functions as an adhesive layer that integrally holds the photosensitive layer 6 to the conductive support 3. Further, the undercoat layer 4 has a function of preventing light reflection of the conductive support 3.

  The undercoat layer 4 is made of a material arbitrarily selected from a binder resin, an organic or inorganic powder, an electron transporting substance, and the like. Here, as the binder resin, acetal resin such as polyvinyl butyral, polyvinyl alcohol resin, casein, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinyl acetate resin , Vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, polymer resin compound such as melamine resin, zirconium chelate compound, titanium chelate compound, aluminum chelate compound, titanium alkoxide compound Known materials such as organic titanium compounds and silane coupling agents can be used. These compounds can be used alone, as a mixture of a plurality of compounds, or as a polycondensate. Among these, a zirconium chelate compound and a silane coupling agent are preferable because they have excellent performance such as a low residual potential, a small potential change due to the environment, and a small potential change due to repeated use.

  Examples of the silane coupling agent include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and γ-glycidoxy. Propyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) ) -Γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, and the like. Among these, particularly preferably used silicon compounds include vinyltriethoxysilane, vinyltris (2-methoxyethoxysilane), 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, Examples include silane coupling agents such as N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-chloropropyltrimethoxysilane.

  Titanium chelate compounds include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium salt, titanium Examples include lactate, titanium lactate ethyl ester, titanium triethanolamate, and polyhydroxytitanium stearate.

  Examples of the aluminum chelate compound include aluminum isopropylate, monobutoxy aluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, and aluminum tris (ethyl acetoacetate).

  In the undercoat layer 4, various organic compound fine powders or inorganic compound fine powders can be added for the purpose of improving electrical characteristics and light scattering properties. In particular, white pigments such as titanium oxide, zinc oxide, zinc white, zinc sulfide, lead white, lithopone, and inorganic pigments such as alumina, calcium carbonate, barium sulfate, polytetrafluoroethylene resin particles, benzoguanamine resin particles, Styrene resin particles are effective. The added fine powder has a particle size of 0.01 to 2 μm. The fine powder is added as necessary, but the addition amount is preferably 10 to 90% by weight, more preferably 30 to 80% by weight based on the total amount of the solid content of the undercoat layer 4. .

  In addition, it is also effective in the undercoat layer 4 to contain the electron transporting substance, the electron transporting pigment and the like described above from the viewpoint of lowering the residual potential and environmental stability. Furthermore, the thickness of the undercoat layer 4 is preferably 0.01 to 30 μm, and more preferably 0.05 to 25 μm.

  In addition, when preparing a coating liquid for forming the undercoat layer 4, when adding a fine powder substance, it is added to a solution in which the resin component is dissolved and dispersed. As the dispersion treatment method, methods such as a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a colloid mill, and a paint shaker can be used.

  The undercoat layer 4 can be formed by applying a coating solution for forming the undercoat layer 4 on the conductive support 3 and drying it. As a coating method at this time, usual methods such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, a curtain coating method, and the like can be used.

  FIG. 1C is a schematic cross-sectional view showing a third embodiment of the electrophotographic photosensitive member of the present invention. The electrophotographic photosensitive member 120 shown in FIG. 1C has the same configuration as the electrophotographic photosensitive member 100 shown in FIG. 1A except that the protective layer 5 is provided on the photosensitive layer 6.

  The protective layer 5 is used to prevent chemical change of the charge transport layer 2 when the electrophotographic photosensitive member 120 is charged or to further improve the mechanical strength of the photosensitive layer 6. The protective layer 5 is formed by applying a coating solution containing a conductive material in an appropriate binder resin onto the photosensitive layer 6. The conductive material is not particularly limited, and examples thereof include metallocene compounds such as N, N′-dimethylferrocene, N, N′-diphenyl-N, N′-bis (3-methylphenyl)-[1, Aromatic amine compounds such as 1′-biphenyl] -4,4′-diamine, molybdenum oxide, tungsten oxide, antimony oxide, tin oxide, titanium oxide, indium oxide, tin oxide and antimony, solid solution of barium sulfate and antimony oxide Carrier, mixture of the above metal oxide, titanium oxide, tin oxide, zinc oxide or barium sulfate mixed with the above metal oxide, or titanium oxide, tin oxide, zinc oxide or sulfuric acid For example, a single particle of barium coated with the above metal oxide.

  The binder resin used for the protective layer 5 is polyamide resin, polyvinyl acetal resin, polyurethane resin, polyester resin, epoxy resin, polyketone resin, polycarbonate resin, polyvinyl ketone resin, polystyrene resin, polyacrylamide resin, polyimide resin, polyamideimide. Known resins such as resins are used. These can also be used by cross-linking each other as necessary.

  The thickness of the protective layer 5 is preferably 1 to 20 μm, and more preferably 2 to 10 μm.

  As a coating method of the coating liquid for forming the protective layer 5, conventional methods such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, and a curtain coating method are used. Can be used. Moreover, as a solvent used for the coating liquid for forming the protective layer 5, a normal organic solvent such as dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, toluene or the like may be used alone or in admixture of two or more. However, it is preferable to use a solvent that hardly dissolves the photosensitive layer 6 to which the coating solution is applied.

  The preferred embodiment of the electrophotographic photoreceptor of the present invention has been described in detail above, but the electrophotographic photoreceptor of the present invention is not limited to the above embodiment. For example, as in the electrophotographic photoreceptor 130 shown in FIG. 2A, the undercoat layer 4 is provided between the conductive support 3 and the photosensitive layer 6, and the protective layer 5 is further provided on the photosensitive layer 6. It may be.

  In the electrophotographic photoreceptors 100, 110, and 120 of the above-described embodiment, the case where the photosensitive layer 6 has a laminated structure has been described. For example, the electrophotographic photoreceptor shown in FIG. As in 140, the photosensitive layer 6 may have a single layer structure. In this case, the undercoat layer 4 may be provided between the conductive support 3 and the photosensitive layer 6, and the protective layer 5 may be provided on the photosensitive layer 6. And the protective layer 5 may be provided.

  The electrophotographic photosensitive member of the present invention described above is provided in an electrophotographic apparatus such as a laser beam printer, a digital copying machine, an LED printer, or a laser facsimile that emits near-infrared light or visible light, and such an electrophotographic apparatus. Can be mounted on a process cartridge. The electrophotographic photoreceptor of the present invention can be used in combination with a one-component or two-component regular developer or reversal developer. The electrophotographic photosensitive member of the present invention is mounted on a contact charging type electrophotographic apparatus using a charging roller or a charging brush, and good characteristics with little occurrence of current leakage can be obtained.

(Electrophotographic apparatus and process cartridge)
3 and 4 are cross-sectional views schematically showing a basic configuration of a preferred embodiment of the electrophotographic apparatus of the present invention.

  An electrophotographic apparatus 200 shown in FIG. 3 includes an electrophotographic photosensitive member 7 of the present invention, a charging unit 8 for charging the electrophotographic photosensitive member 7 by a corona discharge method, a power source 9 connected to the charging unit 8, and a charging unit. Exposure means 10 that exposes the electrophotographic photosensitive member 7 charged by 8 to form an electrostatic latent image, and developing means that develops the electrostatic latent image formed by the exposure means 10 with toner to form a toner image. 11, a transfer unit 12 that transfers the toner image formed by the developing unit 11 to the transfer target 20, a cleaning unit 13, a static eliminator 14, and a fixing device 15.

  The electrophotographic apparatus 210 shown in FIG. 4 has the same configuration as that of the electrophotographic apparatus 200 shown in FIG. 3 except that it includes a charging unit 8 that charges the electrophotographic photoreceptor 7 of the present invention by a contact method. Have In this case, the static eliminator 14 may not be provided.

  Here, as the charging means 8, for example, a contact-type charger using a roller-like, brush-like, film-like or pin-electrode-like conductive or semiconductive charging member, a scorotron charger using a corona discharge, or a corotron A non-contact type charger such as a charger is used.

  As the exposure means 10, an optical system device that can expose a light source such as a semiconductor laser, an LED (light emitting diode), and a liquid crystal shutter in a desired image-like manner on the surface of the electrophotographic photosensitive member is used.

  As the developing means 11, a conventionally known developing means using a regular or reversal developer such as a one-component system or a two-component system is used.

  As the transfer means 12, a contact transfer charger using a belt, a roller, a film, a rubber blade or the like, a scorotron transfer charger using a corona discharge, a corotron transfer charger, or the like is used.

  Although not shown in FIGS. 3 and 4, the electrophotographic apparatus of the present invention may include an intermediate transfer unit. As the intermediate transfer means according to the present invention, a belt-like material such as polyimide, polyamideimide, polycarbonate, polyarylate, polyester, rubber or the like imparting semiconductivity, or a drum-like material other than the belt shape can be used. . Moreover, what has the structure where the elastic layer containing rubber | gum, an elastomer, resin, etc. and the at least 1 layer of coating layer were laminated | stacked on the electroconductive support body can be used. The materials used are polyurethane resin, polyester resin, polystyrene resin, polyolefin resin, polybutadiene resin, polyamide resin, polyvinyl chloride resin, polyethylene resin, fluorine resin, etc. Examples thereof include those obtained by dispersing and mixing conductive carbon particles, metal powder, and the like.

  Further, the electrophotographic apparatus of the present invention may be a so-called tandem type electrophotographic apparatus provided with a plurality of image forming units corresponding to each color of the color toner. For example, when the color toner has four colors of black (K), yellow (Y), magenta (M), and cyan (C), an electrophotographic photosensitive member, a charging device, an exposure device, and a developing device corresponding to each color toner. The four image forming units including the cleaning device may be arranged around the intermediate transfer medium in the moving direction. The toner image created in each unit is primarily transferred onto the intermediate transfer member, and the toner image finally transferred is secondarily transferred onto the recording medium, and further fixed on the recording medium by a fixing device. It is formed.

  In particular, when the electrophotographic photosensitive member of the present invention is used as each of a plurality of tandem type electrophotographic photosensitive members, variation in sensitivity of the photosensitive member between colors can be suppressed, so that occurrence of color unevenness peculiar to a color image is suppressed. This is particularly advantageous.

  FIG. 5 is a cross-sectional view schematically showing a basic configuration of a preferred embodiment of the process cartridge of the present invention. In the process cartridge 300, together with the electrophotographic photosensitive member 7 of the present invention, a charging unit 8, a developing unit 11, a cleaning unit 13, an opening 18 for exposure, and a static eliminator 14 are combined using a mounting rail 16 and integrated. It has become. The process cartridge 300 is detachable from the main body of the electrophotographic apparatus comprising the transfer means 12, the fixing device 15, and other components not shown, and the electrophotographic apparatus together with the main body of the electrophotographic apparatus. It constitutes. The eraseless method may be used without providing the static eliminator 14.

  Since the electrophotographic apparatus and the process cartridge of the present invention described above are equipped with the electrophotographic photosensitive member using the hydroxygallium phthalocyanine mixed pigment of the present invention, stable image quality can be obtained over a long period without causing image quality defects. Can get.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example at all.

[Preparation of pigment]
(Synthesis Example 1: Synthesis of I-type hydroxygallium phthalocyanine crystal)
30 parts by mass of 1,3-diiminoisoindoline and 9.1 parts by mass of gallium trichloride were added to 230 parts by mass of dimethyl sulfoxide and reacted at 160 ° C. with stirring for 6 hours to obtain reddish purple crystals. The obtained crystal was washed with dimethyl sulfoxide, then washed with ion-exchanged water, and dried to obtain 28 parts by mass of crude crystals of type I chlorogallium phthalocyanine.

  Next, a solution in which 10 parts by mass of the obtained crude crystals of type I chlorogallium phthalocyanine were sufficiently dissolved in 300 parts by mass of sulfuric acid (concentration 97%) heated to 60 ° C. was mixed with 600 parts by mass of 25% aqueous ammonia and ions. It was dripped in the mixed solution with 200 mass parts of exchange water, and the hydroxygallium phthalocyanine crystal | crystallization was deposited. The crystals were collected by filtration, washed with ion exchange water, and then dried to obtain 8 parts by mass of type I hydroxygallium phthalocyanine crystals. As a result of measuring the X-ray diffraction spectrum of the obtained I-type hydroxygallium phthalocyanine crystal using an X-ray diffractometer (X-ray diffractometer Miniflex manufactured by Rigaku Corporation), a Bragg angle (2θ ± 0.2 °) was obtained. It was confirmed to have diffraction peaks at 6.9 °, 13.2 to 14.2 °, 16.5 °, 26.0 ° and 26.4 °.

(Synthesis Example 2)
As an electron transporting pigment, 1 part by mass of the type I hydroxygallium phthalocyanine crystal obtained in Synthesis Example 1 was used as an electron transporting polycyclic quinone pigment dibromoanthanthrone pigment (Monolite Red 2Y). ) Together with 0.1 parts by mass, 15 parts by mass of N, N-dimethylformamide, and 55 parts by mass of glass spherical media with an outer diameter of 0.9 mm, wet grinding was performed at 25 ° C. for 144 hours using a glass ball mill. .

Next, the crystals obtained by the above-described wet pulverization treatment are washed with acetone, dried, and X-ray diffraction spectrum using CuKα characteristic X-rays has a Bragg angle (2θ ± 0.2 °) of 7. 1 part by mass of a hydroxygallium phthalocyanine mixed pigment having diffraction peaks at 5 °, 9.9 °, 12.5 °, 16.3 °, 18.6 °, 25.1 ° and 28.3 ° was obtained. The X-ray diffraction spectrum of the obtained hydroxygallium phthalocyanine mixed pigment is shown in FIG. Moreover, the maximum peak wavelength (λ _MAX ) in the spectral absorption spectrum in the wavelength region of 600 to 900 nm of the obtained hydroxygallium phthalocyanine mixed pigment, and a BET specific surface area measuring instrument (Flow Soap II 2300, manufactured by Shimadzu Corporation) Table 12 shows the results of the BET specific surface areas measured using the above.

(Synthesis Example 3)
Instead of 0.01 parts by mass of the dibromoanthanthrone pigment in Synthesis Example 2, 0.05 parts by mass of benzimidazole perylene pigment, which is a mixture of compounds represented by the following structural formulas (B-1) and (B-2), is used. Except for the above, a hydroxygallium phthalocyanine mixed pigment was prepared in the same manner as in Synthesis Example 2. The obtained hydroxygallium phthalocyanine mixed pigment was measured for X-ray diffraction spectrum, and Bragg angles (2θ ± 0.2 °) 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6. It was confirmed to have diffraction peaks at °, 25.1 °, and 28.3 °. Table 12 shows the results of λ _MAX and BET specific surface area of the obtained hydroxygallium phthalocyanine mixed pigment in the wavelength region of 600 to 900 nm.

(Synthesis Example 4)
Hydroxygallium in the same manner as in Synthesis Example 2 except that 0.01 parts by mass of the bisazo pigment represented by the following structural formula (C-3) was used instead of 0.1 parts by mass of the dibromoanthanthrone pigment in Synthesis Example 2. A phthalocyanine mixed pigment was prepared. The obtained hydroxygallium phthalocyanine mixed pigment was measured for X-ray diffraction spectrum, and Bragg angles (2θ ± 0.2 °) 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6. It was confirmed to have diffraction peaks at °, 25.1 °, and 28.3 °. Table 12 shows the results of λ _MAX and BET specific surface area of the obtained hydroxygallium phthalocyanine mixed pigment in the wavelength region of 600 to 900 nm.

(Synthesis Example 5)
A hydroxygallium phthalocyanine mixed pigment was prepared in the same manner as in Synthesis Example 2 except that 0.05 part by mass of a dichlorotin phthalocyanine pigment was used instead of 0.1 part by mass of the dibromoanthanthrone pigment in Synthesis Example 2. The obtained hydroxygallium phthalocyanine mixed pigment was measured for X-ray diffraction spectrum, and Bragg angles (2θ ± 0.2 °) 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6. It was confirmed to have diffraction peaks at °, 25.1 °, and 28.3 °. Table 12 shows the results of λ _MAX and BET specific surface area of the obtained hydroxygallium phthalocyanine mixed pigment in the wavelength region of 600 to 900 nm.

(Comparative Synthesis Example 1)
30 parts by mass of 1,3-diiminoisoindoline and 9.1 parts by mass of gallium trichloride were reacted in 230 parts by mass of quinoline while stirring at 200 ° C. for 3 hours to obtain red-violet crystals. Next, after washing with acetone and methanol, the wet cake was dried to obtain 28 parts by mass of crude crystals of type I chlorogallium phthalocyanine. The obtained crude crystals of type I chlorogallium phthalocyanine (3 parts by mass) were dissolved in 60 parts by mass of sulfuric acid (concentration 97%) at 60 ° C. and then dropped into 450 parts by mass of 5 ° C. distilled water to precipitate crystals. . It was washed with distilled water, dilute ammonia water, etc. and dried to obtain 2.5 parts by mass of hydroxygallium phthalocyanine crystals. After milling 0.5 parts by mass of the obtained hydroxygallium phthalocyanine crystal together with 15 parts by mass of dimethylformamide and 30 parts by mass of glass beads having a diameter of 1 mm, the crystals were separated. Next, after washing with methanol and drying, 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6 ° of Bragg angles (2θ ± 0.2 °) with respect to CuKα characteristic X-rays Thus, 0.4 parts by mass of a hydroxygallium phthalocyanine pigment having diffraction peaks at 25.1 ° and 28.3 ° were obtained. Table 12 shows the results of λ _MAX and BET specific surface area of the obtained hydroxygallium phthalocyanine pigment in the wavelength region of 600 to 900 nm.

(Comparative Synthesis Example 2)
A hydroxygallium phthalocyanine mixed pigment was prepared in the same manner as in Synthesis Example 2 except that the addition amount of the dibromoanthanthrone pigment in Synthesis Example 2 was changed from 0.1 parts by mass to 0.5 parts by mass. The X-ray diffraction spectrum of the obtained hydroxygallium phthalocyanine mixed pigment is shown in FIG. Table 1 shows the results of λ _MAX and the BET specific surface area of the obtained hydroxygallium phthalocyanine mixed pigment in the wavelength region of 600 to 900 nm.

(Comparative Synthesis Example 3)
18 parts by mass of titanyloxyphthalocyanine and 2 parts by mass of dibromoanthanthrone were dry milled for 15 hours with a glass bead together with glass beads to obtain 18 parts by mass of an amorphous material. 1 part by mass of the obtained amorphous body, 30 parts by mass of water, and 2 parts by mass of 0-dichlorobenzene were placed in a flask and heated and stirred at 50 ° C. After 1 hour, stirring was stopped and the mixture was allowed to cool to room temperature. Then, the solvent was removed and dried to obtain a mixed pigment of titanyloxyphthalocyanine and dibromoanthanthrone. Table 12 shows the results of λ _MAX and the BET specific surface area of the obtained mixed pigment in the wavelength region of 600 to 900 nm.

[Production of electrophotographic photosensitive member]
Example 1
First, an aluminum sheet having a thickness of 50 μm was prepared as a conductive support.

Next, 100 parts by mass of zinc oxide (average particle size 70 nm: prototype manufactured by Teika: specific surface area value 15 m ² / g) is stirred and mixed with 500 parts by mass of toluene, and a silane coupling agent (KBM603: manufactured by Shin-Etsu Chemical Co., Ltd.) 1.25 parts by mass were added and the mixture was further stirred for 2 hours. Thereafter, toluene was distilled off under reduced pressure and baked at 120 ° C. for 2 hours to obtain a surface-treated zinc oxide pigment.

  Next, 60 parts by mass of the obtained surface-treated zinc oxide pigment, 13.5 parts by mass of a curing agent (blocked isocyanate Sumijoule 3175, manufactured by Sumitomo Bayern Urethane Co., Ltd.), and butyral resin (BM-1, manufactured by Sekisui Chemical Co., Ltd.) 15 Part by mass was dissolved in 85 parts by mass of methyl ethyl ketone. 38 parts by mass of this solution and 25 parts by mass of methyl ethyl ketone were mixed, and dispersion treatment was performed for 2 hours with a sand mill using 1 mmφ glass beads. To the obtained dispersion, 0.005 parts by mass of dioctyltin dilaurate and 3.4 parts by mass of silicone resin particles (Tospearl 145 (manufactured by GE Toshiba Silicone)) were added as a catalyst to obtain a coating liquid for forming an undercoat layer. This coating solution was applied onto the aluminum sheet by a dip coating method, followed by drying and curing at 170 ° C. for 40 minutes to form an undercoat layer having a thickness of 25 μm.

  Next, a solution obtained by dissolving 1 part by mass of vinyl chloride-vinyl acetate copolymer resin (VMCH, manufactured by Nihon Unicar Co., Ltd.) in 100 parts by mass of n-butyl acetate, and the hydroxygallium phthalocyanine mixed pigment 2 obtained in Synthesis Example 2 Mass parts were mixed and dispersed with a glass bead in a sand mill for 3 hours to prepare a coating solution for forming a charge generation layer. The obtained coating solution was dip-coated on the undercoat layer and dried by heating at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.20 μm.

  Furthermore, 4 parts by mass of N, N′-diphenyl-N, N′-bis (3-methyl)-[1,1′biphenyl] -4,4′-diamine as a charge transport material, and bisphenol Z type as a binder resin 6 parts by weight of polycarbonate resin (viscosity average molecular weight: 30,000), 80 parts by weight of tetrahydrofuran, and 0.2 part by weight of 2,6-di-t-butyl-4-methylphenol are mixed and applied for forming a charge transport layer. A liquid was prepared. This coating solution was dip-coated on the charge generation layer and dried by heating at 120 ° C. for 40 minutes to form a charge transport layer having a film thickness of 25 μm, thereby producing a target electrophotographic photosensitive sheet.

  In addition, the subbing layer, the charge generation layer, and the charge transport layer were sequentially formed in the same procedure as the production of the electrophotographic photosensitive sheet except that a cylindrical aluminum substrate having an outer diameter of 30 mmφ was used as the conductive support. The target electrophotographic photosensitive drum was prepared.

(Example 2)
An electrophotographic photosensitive sheet and an electrophotographic photosensitive drum were prepared in the same manner as in Example 1 except that the hydroxygallium phthalocyanine mixed pigment of Synthesis Example 3 was used instead of the hydroxygallium phthalocyanine mixed pigment obtained in Synthesis Example 2. Produced.

(Example 3)
An electrophotographic photosensitive sheet and an electrophotographic photosensitive drum were prepared in the same manner as in Example 1 except that the hydroxygallium phthalocyanine mixed pigment of Synthesis Example 4 was used instead of the hydroxygallium phthalocyanine mixed pigment obtained in Synthesis Example 2. Produced.

Example 4
An electrophotographic photosensitive sheet and an electrophotographic photosensitive drum were prepared in the same manner as in Example 1 except that the hydroxygallium phthalocyanine mixed pigment of Synthesis Example 5 was used instead of the hydroxygallium phthalocyanine mixed pigment obtained in Synthesis Example 2. Produced.

(Comparative Example 1)
An electrophotographic photosensitive sheet and an electrophotographic photosensitive drum were prepared in the same manner as in Example 1 except that the hydroxygallium phthalocyanine pigment of Comparative Synthesis Example 1 was used instead of the hydroxygallium phthalocyanine mixed pigment obtained in Synthesis Example 2. Produced.

(Comparative Example 2)
An electrophotographic photosensitive sheet and an electrophotographic photosensitive drum were obtained in the same manner as in Example 1 except that the hydroxygallium phthalocyanine mixed pigment of Comparative Synthesis Example 2 was used instead of the hydroxygallium phthalocyanine mixed pigment obtained in Synthesis Example 2. Was made.

(Comparative Example 3)
An electrophotographic photosensitive sheet and an electrophotographic photosensitive drum were obtained in the same manner as in Example 1 except that the titanyloxyphthalocyanine mixed pigment of Comparative Synthesis Example 3 was used instead of the hydroxygallium phthalocyanine mixed pigment obtained in Synthesis Example 2. Was made.

[Evaluation test of electrophotographic characteristics at the beginning of use]
In order to evaluate the electrophotographic characteristics of the electrophotographic photoreceptor sheets of Examples 1 to 4 and Comparative Examples 1 to 3, the electrophotographic characteristics were measured by the following procedure. First, using a small area mask with a diameter of 20 mm, and using an electrostatic copying paper test apparatus (EPA8200, manufactured by Kawaguchi Electric Co., Ltd.) in an environment of 20 ° C. and 50% RH, the photosensitive member is discharged by corona discharge of −5.0 kV. Negatively charged. Subsequently, a halogen lamp light split at 780 nm using an interference filter was adjusted and irradiated on the surface of the photoreceptor so as to be 5.0 μW / cm ² . At this time, the initial surface potential V ₀ [V], the half exposure amount E _1/2 [μJ / cm ² ] until the surface potential becomes 1/2 of V ₀ , and the dark decay rate (DDR, from the surface potential V 0) When the surface potential after 1 second was defined as V1, {value [%] represented by (V0−V1) / V0} × 100) was measured. The obtained results are shown in Table 13.

[Image quality evaluation test]
First, the electrophotographic photosensitive drums of Examples 1 to 4 and Comparative Examples 1 to 3 were mounted on a laser printer PR1000 manufactured by NEC Corporation, and the following image quality evaluation test was performed. Note that this laser printer is an eraseless electrophotographic apparatus that performs charging, exposure, development, and transfer, and then performs the next charging without neutralization, except that it does not include a static eliminator. It has the same configuration as a photographic apparatus. In this laser printer, a roller charger (BCR) as a charging device, a ROS using a 780 nm semiconductor laser as an exposure device, a one-component reversal development method as a development method, and a roller charger (BTR) as a transfer device. Adopted.

  Using the above-mentioned laser printer, in a 20 ° C./50% RH environment, a character pattern of “G” is printed for one revolution of the drum in the initial stage, and then an entire halftone image of one dot and one space and an entire white image ( A background image was output and the image was observed visually and with a magnifying glass to evaluate positive ghost and fogging. Next, after outputting 20,000 images printed with a line of about 2 mm width every 7 mm in length and width, and printing the character pattern of “G” for one round of the drum in the same manner as described above, the entire surface half of 1 dot 1 space Tone images and background images were output to evaluate positive ghosts and fogging. The obtained results are shown in Table 13. In the “Cover” column of Table 13, “A” indicates that no fog was observed, “B” indicates that a slight amount of fog was observed, but the level was practically satisfactory, “C”. "" Means that the fog was clearly recognized. Moreover, in the column of “Positive Ghost” in Table 13, “A” indicates that no positive ghost was recognized, and “B” indicates that a slight positive ghost was recognized, but it was at a level causing no practical problem. , “C” means that positive ghost was clearly recognized.

[Dispersibility evaluation test of coating solution for charge generation layer]
The charge generation layer coating solutions used in Examples 1 to 4 and Comparative Examples 1 to 3 were evaluated for dispersibility as follows.

  A charge generation layer was formed on a glass plate in the same procedure as in each example or comparative example, and the dispersion state of the constituent components in the charge generation layer was observed using a microscope. The obtained results are shown in Table 2. In Table 13, “A” means that no agglomerates were observed in the charge generation layer, and that the surface state of the charge generation layer was good, and “B” showed agglomerates. Or the surface of the charge generation layer is rough.

(A)-(c) is a schematic cross section which shows 1st-3rd embodiment of the electrophotographic photoreceptor of this invention, respectively. (A)-(b) is a schematic cross section which shows other embodiment of the electrophotographic photoreceptor of this invention, respectively. 1 is a cross-sectional view schematically illustrating a basic configuration of a preferred embodiment of an electrophotographic apparatus of the present invention. It is sectional drawing which shows schematically the basic composition of other suitable one Embodiment of the electrophotographic apparatus of this invention. 1 is a cross-sectional view schematically showing a basic configuration of a preferred embodiment of a process cartridge of the present invention. 3 is a powder X-ray diffraction pattern of a hydroxygallium phthalocyanine mixed pigment obtained in Synthesis Example 2. FIG. 6 is a powder X-ray diffraction pattern of a hydroxygallium phthalocyanine mixed pigment obtained in Comparative Synthesis Example 2. FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Charge generating layer, 2 ... Charge transport layer, 3 ... Conductive support body, 4 ... Undercoat layer, 5 ... Protective layer, 6 ... Photosensitive layer, 7 ... Electrophotographic photoreceptor, 8 ... Charging means, 9 ... Power supply DESCRIPTION OF SYMBOLS 10 ... Exposure means, 11 ... Developing means, 12 ... Transfer means, 13 ... Cleaning means, 14 ... Static eliminator, 15 ... Fixing device, 16 ... Mounting rail, 18 ... Opening for exposure, 20 ... Transfer object , 100, 110, 120, 130, 140 ... electrophotographic photosensitive member, 200, 210 ... electrophotographic apparatus, 300 ... process cartridge.

Claims (7)

  A mixed pigment of a hydroxygallium phthalocyanine pigment and an electron transporting pigment used as a constituent material of an electrophotographic photosensitive member, and a mixture containing a hydroxygallium phthalocyanine crystal, an electron transporting pigment, and a predetermined solvent is wet-pulverized. And X-ray diffraction pattern using CuKα characteristic X-rays, Bragg angles (2θ ± 0.2 °) 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18 A hydroxygallium phthalocyanine mixed pigment characterized by having diffraction peaks at .6 °, 25.1 ° and 28.3 °.   2. The hydroxygallium phthalocyanine mixed pigment according to claim 1, having a maximum peak wavelength in a range of 810 to 839 nm in a spectral absorption spectrum in a wavelength region of 600 to 900 nm. A method for producing a mixed pigment of a hydroxygallium phthalocyanine pigment and an electron transporting pigment used as a constituent material of an electrophotographic photoreceptor,
The obtained mixed pigment has an Bragg angle (2θ ± 0.2 °) of 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18 in an X-ray diffraction pattern using CuKα characteristic X-rays. A wet pulverization process step for wet pulverizing a mixture containing a hydroxygallium phthalocyanine crystal, an electron transporting pigment, and a predetermined solvent so as to have diffraction peaks at .6 °, 25.1 °, and 28.3 °. A method for producing a hydroxygallium phthalocyanine mixed pigment, A conductive support;
A photosensitive layer provided on the conductive support, containing the hydroxygallium phthalocyanine mixed pigment according to claim 1 or 2,
An electrophotographic photosensitive member comprising: The electrophotographic photosensitive member according to claim 4,
Charging means for charging the electrophotographic photoreceptor;
Exposure means for forming an electrostatic latent image on the charged electrophotographic photosensitive member;
Developing means for developing the electrostatic latent image formed on the electrophotographic photosensitive member with toner to form a toner image;
Transfer means for transferring the toner image from the electrophotographic photosensitive member to a transfer medium;
An electrophotographic apparatus comprising:   The charging unit includes a charging member that is disposed in contact with the electrophotographic photosensitive member and to which a voltage is applied. The electrophotographic apparatus sequentially performs charging, exposure, development, and transfer, and then the electrophotographic photosensitive member. The electrophotographic apparatus according to claim 5, wherein the electrophotographic apparatus is an eraseless electrophotographic apparatus that performs the next charging without discharging the body. The electrophotographic photosensitive member according to claim 4,
Charging means for charging the electrophotographic photosensitive member, developing means for developing a latent electrostatic image formed on the electrophotographic photosensitive member with toner to form a toner image, and remaining on the electrophotographic photosensitive member At least one selected from cleaning means for removing the toner,
A process cartridge comprising:

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