JP2002038047A - Hybrid pigment, method for producing hybrid pigment and electrophotographic photoreceptor using the hybrid pigment, image-forming equipment, and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor which reduces the fatigue due to the exposure to a large quantity of light and reduces the difference in chargeability of the photoreceptor between the first rotation of the photoreceptor conductor and the second and subsequent rotations even after repeated use and can form a good image from its first rotation, image-forming equipment, and a process cartridge. SOLUTION: The hybrid pigment can be obtained by hybridizing a compound containing one or more metallic atoms with a metal-free pigment, the X-ray diffraction pattern of the hybrid pigment being substantially the same as that of the above metal-free pigment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pigment capable of performing photoelectric conversion (hereinafter, also referred to as pigment particles) and a method for producing the pigment. Further, the present invention relates to an electrophotographic photosensitive member for forming an electrostatic latent image using the pigment. Further, the present invention relates to an image forming apparatus and a process cartridge using the photosensitive member.

[0002]

2. Description of the Related Art Since the discovery of an electrophotographic photoreceptor using a charge transfer complex of 2,4,6-trinitro-9-fluorenone and poly-N-vinylcarbazole (hereinafter simply referred to as a photoreceptor), an organic photoreceptor has been developed. Development of electrophotographic photoreceptors has progressed, and improvements in sensitivity, durability and the like of photoreceptors have been reported over the years. In addition, a function-separated organic photoreceptor has been developed, and various compounds have been announced to date.

[0003] Regarding the charge generating material, research on various azo pigments, condensed polycyclic pigments, various phthalocyanine pigments, etc. has been reported to meet the demand for stable high speed and high sensitivity performance. Very sensitive compounds have been developed in groups.

However, apart from a simple improvement in charge generation efficiency, not all requirements for charge generation materials have been solved, and the following problems still remain. Since it is difficult to improve the purity of the azo pigment, it is difficult to obtain stable and high-level performance. The phthalocyanine-based pigments have a problem that the performance changes due to environmental differences such as temperature and humidity are relatively large, and that the charging potential immediately after pausing is lower than the charging potential after the second use when repeatedly used for a long period of time. This phenomenon causes a copy image formed on the first rotation of the photoreceptor to be clearly inferior to that after the second rotation, particularly in reversal development. The image defect is conspicuous and serious because it originally appears as toner fog on a white background.

In order to cope with this problem, a process is employed in which the first to several rotations of the photosensitive member are forced to idle to stabilize the charging potential, and an image is formed after two to several rotations thereafter. . Therefore, the power consumption of the idle rotation of the photoconductor is wasted, and the time required to output the first image is also wasted, which is an obstacle to the protection of the global environment, resources, and high speed. A solution is desired.

On the other hand, condensed polycyclic pigments are excellent in stability but many have short absorption wavelengths, and many do not have practical sensitivity to semiconductor laser light, which is a light source of recent digitization. Among them, bisimidazole perylene is 7
High charge generation efficiency even in the wavelength region near 00 nm,
Excellent stability of environment and electrophotographic properties during long-term use. However, there is a problem that the sensitivity is remarkably reduced by continuing the strong exposure, and when using a semiconductor laser light source having a high exposure intensity, the sensitivity is extremely reduced, so that the use conditions are restricted. I have.

In general, when a plurality of pigment particles are mixed and used in an electrophotographic photosensitive member, different types of particles produced separately are mixed at the time of production and a uniform appearance is obtained by means such as dispersion. Or a mixture of different particles that are first made fine by dispersion or the like is mixed to obtain a uniform state. According to JP-A-7-128889 and the like, a charge generation layer is formed by mixing gallium phthalocyanine and a bisimidazole perylene compound by the above method.

On the other hand, there is also known a method in which a plurality of substances are once mixed at a molecular level in a particle preparation stage, and then particles containing the substances at the same time are prepared. Means for mixing at the molecular level include co-evaporation, acid paste processing, and melt mixing. Examples of the production of a charge generating agent using such a method include JP-A-7-114196 (mixture of titanyl phthalocyanine / perylene bisimide) and JP-A 9-1196.
No. 57540 (mixture of different types of phthalocyanines);
No. 50553 (mixture of different types of phthalocyanine and naphthalocyanine), JP-A-7-5715 (mixture of metal-free phthalocyanine / perylenecarboxylic diimide, diimidazole), JP-A-8-110649 (mixture of titanyl phthalocyanine / metal-free phthalocyanine), and the like. There is a description.

However, the object of these inventions is mainly to renew the existing crystal form, to broaden the spectral sensitivity and to increase the sensitivity, and to carry out the light fatigue due to the strong exposure and the change in the chargeability after repeated use as described above. No solution is given for this problem.

[0010] In fact, no charge generating substance has been found yet that can achieve both ideal electrophotographic characteristics and stability when an electrophotographic photosensitive member is formed.

[0011]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a pigment which achieves the following performance in view of the above-mentioned problems of the prior art, a method for producing the pigment, an electrophotographic photoreceptor using the pigment particles, and an electrophotographic photosensitive member. An object of the present invention is to provide an image forming apparatus and a process cartridge using a photographic photosensitive member. 1) Fatigue due to large light exposure is small. 2) Even after repeated use, there is little difference in chargeability between the first and second rotations of the photoreceptor, and a good image is formed from the first rotation. 3) The potential and the image are stable against changes in the use environment such as high temperature, high humidity, low temperature, and low humidity. 4) The image characteristics are stable with little change in the characteristics of the photoreceptor upon repeated use.

[0012]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, have found that the above-mentioned object can be achieved by the configuration described below.

[0013] The X-ray diffraction pattern of a hybrid pigment obtained by mixing a compound containing one or more metal atoms with a metal-free pigment is substantially the same as the X-ray diffraction pattern of the metal-free pigment. Hybrid pigments.

2. The metal atom of the hybrid pigment is Ti, C
2. The hybrid pigment as described in 1 above, which is at least one selected from u, Fe, V, Ga, Si, Pb, Al, Zn, and Mg.

3. The hybrid pigment has a metal atom content of 50.
3. The hybrid pigment according to the above 1 or 2, wherein the content is from 1 ppm to 10000 ppm.

4. The hybrid pigment according to any one of the above items 1 to 3, wherein the metal atom-containing compound is a metal phthalocyanine compound.

5. 5. The hybrid pigment according to the item 4, wherein the content of the metal phthalocyanine compound in the hybrid pigment is 0.01 to 10% by mass.

6. The hybrid pigment according to any one of the above items 1 to 5, wherein the hybrid pigment contains a perylene compound as a main component.

[7] 7. The hybrid pigment according to the item 6, wherein the perylene compound is bisimidazole perylene of the compound (1) represented by the structure.

8. 8. A method for producing a hybrid pigment, comprising: producing the hybrid pigment according to any one of 1 to 7 by acid paste treatment.

9. An electrophotographic photosensitive member comprising the hybrid pigment according to any one of the above items 1 to 7.

10. An image forming apparatus having at least each of charging, image exposure, development, and transfer means around an electrophotographic photosensitive member, wherein an image is formed using the electrophotographic photosensitive member according to the above item 9. .

11. 10. A process cartridge used in an image forming apparatus having at least respective units of charging, image exposure, development, and transfer around an electrophotographic photosensitive member, wherein the process cartridge comprises the electrophotographic photosensitive member described in the item 9 and a charging unit, A process cartridge having at least one of a developing unit, a developing unit, and a transfer unit, and being designed to be freely inserted into and removed from the image forming apparatus.

Hereinafter, the present invention will be described. The feature of the state of the metal particles contained in the pigment particles, which is the main technology of the present invention, will be described.

First, means for mixing a plurality of substances and compounds after the preparation of pigment particles is referred to as pigment mixing or pigment mixing particles.

The operation of mixing a plurality of substances at the molecular level at the stage of preparing pigment particles is referred to as a hybrid treatment, and particles containing a plurality of substances and compounds produced through the same operation are mixed pigments or mixed pigments. Recorded as particles. The pigment particles of the present invention were developed using this hybrid pigment as a basic technology.

Here, the hybrid pigment described in the present invention will be described in detail. First, a hybrid pigment is characterized in that a plurality of substances (for example, a pigment and a metal atom-containing compound) are once mixed at a molecular level in a particle production stage. Thereafter, the particles are formed as pigment particles containing a plurality of substances and compounds at the same time in order to perform an operation of forming particles.

The hybrid substance and a part of the compound are incorporated into the particles in a molecular state, so that depending on the energy level of the compound and the energy level of the compound, an impurity level is created in the semiconductor mechanism of the charge generating agent. It is speculated that this could be a solution to various problems that might have been caused by the trap levels inside.

Further, even after the dispersion treatment or the like is performed on the composite pigment and the mixture is atomized to a state where a photosensitive layer which does not cause image defects can be formed, a plurality of types of substances mixed during the preparation of the composite pigment remain in the particles.
Compound is contained.

On the other hand, in pigment mixing, it is considered that a plurality of pigments exist independently as particles at any stage of mixing and dispersion from the time of preparing the pigment particles. For example, some particles form an aggregate. However, even if the pigment is in a dissolved state and penetrates into the particles, the state is different from that of a hybrid pigment obtained from a homogeneously dispersed state at the molecular level such as a hybrid.

An X-ray diffraction pattern of a hybrid pigment obtained by mixing one or more compounds containing a metal atom and a metal-free pigment according to the present invention is substantially the same as the X-ray diffraction pattern of the metal-free pigment. In order to specifically describe the hybrid pigment, a perylene pigment is used as the metal-free pigment of the hybrid pigment component, and a metal phthalocyanine compound is used as the metal atom-containing compound. Here, the metal-free pigment means a pigment containing no metal atom.

That is, X of the perylene hybrid pigment obtained by adding one or more metal atoms to the perylene pigment
The fact that the X-ray diffraction pattern is substantially the same as the X-ray diffraction pattern of the perylene pigment means the following.

The X-ray diffraction pattern of the hybrid pigment of the present invention obtained by the hybrid treatment of perylene and the metal atom-containing compound can be obtained by performing the same treatment with the perylene pigment alone without mixing the metal atom-containing compound. This means that the X-ray diffraction pattern of the perylene pigment is substantially the same. here,
Substantially the same means that a new X-ray diffraction peak due to the metal atom-containing compound (for example, metal phthalocyanine) or the like mixed during the hybridizing treatment has not been generated.

The electrophotographic photoreceptor using the hybrid pigment containing a metal atom of the present invention obtained as described above as a charge generating substance has a small decrease in sensitivity at the time of exposure to a large amount of light, and after a pause after repeated use. Also, the difference in chargeability between the first rotation and the second rotation of the photoconductor is small. In addition, it exhibits extremely stable electrophotographic performance against changes in environmental conditions such as temperature and humidity, and maintains excellent electrophotographic performance even when used repeatedly for a long period of time. Due to these excellent characteristics, a stable electrophotographic image can be provided in various environments and electrophotographic process conditions.

In the present invention, it is preferable to use a metal-free perylene pigment as the main pigment of the hybrid pigment component, and to use a metal phthalocyanine compound as the metal atom-containing compound.

Examples of materials which can be used for forming an electrophotographic photoreceptor are described below in order to specifically explain the excellent characteristics of the present invention. However, the essence of the present invention is not limited by these specific examples. It is not done.

As the perylene compound in the present invention, the following compounds can be exemplified in addition to the compound (1).

[0038]

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[0039]

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Of these, bisimidazole perylene of the above-mentioned compound (1) is most preferred. Compound (1) generally has structural isomers.

On the other hand, a phthalocyanine compound having a metal atom is preferable as the metal atom-containing compound to be mixed in the hybrid treatment. Examples of the phthalocyanine compound having a metal atom include Ti, Cu, Fe, V, Ga, Si, P
It is preferable to use a phthalocyanine compound having at least one metal of b, Al, Zn, and Mg. Further, T
Most preferably, a phthalocyanine compound having metals of i, Cu, V and Ga is used. The metal atom content of the perylene hybrid pigment is preferably from 50 ppm to 10000 ppm. When the perylene hybrid pigment of the present invention contains a metal atom in the above range, an electrophotographic photoreceptor exhibiting good characteristics can be produced. That is, the electrophotographic photoreceptor using the hybrid pigment as a charge generating substance has a small decrease in sensitivity upon exposure to a large amount of light, and a small difference in chargeability between the first and second rotations of the photoreceptor even after a pause after repeated use. .

In order to achieve the metal atom content of the perylene hybrid pigment, the content of the metal phthalocyanine compound in the perylene hybrid pigment is preferably 0.01 to 10% by mass. By mixing the metal phthalocyanine in such a ratio at the time of the hybridizing process for preparing the perylene hybrid pigment, the metal atom content of the perylene hybrid pigment is reduced to 50 ppm or less.
It can be adjusted to the range of 10,000 ppm.

The hybrid treatment for obtaining the perylene hybrid pigment of the present invention includes the above-mentioned methods such as co-evaporation, acid paste treatment and melt mixing. In the present invention, the hybrid treatment by acid paste treatment is preferable. .

In the present invention, the acid paste treatment means that the pigment is dissolved once in an acid capable of dissolving the pigment (sulfuric acid or the like), the insoluble matter is removed by a filter if necessary, and then the pigment solution is dissolved in a suitable poor solvent (for example, water). And then re-particulate. Examples are shown in the synthesis examples below.

Next, the layer structure and the like of an electrophotographic photosensitive member using the perylene mixed pigment of the present invention will be described.

In the present invention, a laminated photoreceptor having a carrier generating layer as a lower layer and a carrier transporting layer as an upper layer can be provided. Further, a single layer type photoreceptor can be obtained by mixing and dispersing a carrier generating substance, a carrier transporting substance and other additives. It is also possible to provide a photoreceptor containing a carrier transporting substance in the lower layer and a charge generating substance in the upper layer. In any layer configuration, a protective layer may be provided on the photosensitive layer. Further, an intermediate layer may be provided between the conductive substrate and the photosensitive layer.

In the formation of the photosensitive layer, the carrier-generating layer is formed by applying a liquid in which the carrier-generating substance is dispersed alone or in a suitable dispersion medium together with a binder or an additive, or by vacuum-depositing the carrier-generating substance. Is valid. In the former case, as the dispersing means, a dispersing device such as an ultrasonic dispersing machine, a ball mill, a sand mill, and a homomixer can be used.

The carrier transporting layer can be formed by applying a carrier transporting substance alone or a solution in which the carrier transporting substance is dissolved together with a binder or an additive using an applicator, a bar coater, a dip coater, a ring coater or the like, and drying. it can. The intermediate layer, the charge generation layer, the protective layer and the like can be formed by the same means.

Examples of the polymer useful as a binder used for the photosensitive layer and the protective layer include polystyrene resin, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, polyvinyl butyral resin, epoxy resin,
Examples include polyurethane resins, phenol resins, polyester resins, alkyd resins, polycarbonate resins, silicone resins, melamine resins, and copolymer resins containing two or more of these repeating units. Further, in addition to these insulating resins, a polymer organic semiconductor such as polyvinyl-N-carbazole may be used.

Examples of the dispersion medium of the carrier generating substance and the carrier transporting substance include hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as methylene chloride and 1,2-dichloroethane; ketones such as methyl ethyl ketone and cyclohexanone; Esters such as ethyl and butyl acetate; alcohols such as methanol, ethanol, propanol, butanol, methylcellosolve and ethylcellosolve and derivatives thereof; tetrahydrofuran, 1,4
Ethers such as dioxane and 1,3-dioxolane;
Amines such as pyridine and diethylamine; nitrogen compounds such as amides such as N, N-dimethylformamide; other fatty acids and phenols; one or more of sulfur and phosphorus compounds such as carbon disulfide and triethyl phosphate; Can be used.

The ratio of the carrier-generating substance to the binder is preferably 1 to 600 parts by mass with respect to 100 parts by mass of the binder. The ratio of the carrier transporting substance to the binder is based on 100 parts by mass of the binder.
The carrier transporting material is preferably 10 to 500 parts by mass. The thickness of the carrier generation layer is preferably from 0.01 to 20 μm. The thickness of the carrier transport layer is generally 1 to 100 μm,
Further, the thickness is preferably 5 to 50 μm. In the case of a single-layer type electrophotographic photoreceptor, the ratio of binder: additive: carrier generating substance, carrier transporting substance is 100: 1 to 200:
1 to 200: 1 to 200 is preferable, and the dry thickness of the formed photosensitive layer is preferably 5 to 50 μm.

As the conductive support, a metal plate, a metal drum, or a conductive compound such as a conductive polymer or indium oxide, or a thin layer of a metal such as aluminum or palladium is applied, deposited, laminated, or the like. What is provided on a substrate such as paper or a plastic film by means can be used.

In the photosensitive layer of the present invention, any compound such as a triphenylamine derivative, a triphenylamine-styryl derivative, a hydrazone derivative, a tetraphenylbenzidine derivative, and a butadiene derivative can be used as a carrier transporting agent. Specific examples are shown below.

[0054]

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[0055]

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[0056]

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[0057]

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[0058]

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In the photosensitive layer, an antioxidant can be added. Examples of the antioxidant include hindered phenols, hindered amines, paraphenylenediamines, hydroquinones, and organic phosphorus compounds.

The photoreceptor may further contain, if necessary, an ultraviolet absorber or a dye for color sensitivity correction for the purpose of protecting the photosensitive layer.

After synthesizing the perylene hybrid pigment of the present invention,
Further, it can be converted into a desired crystal form by means such as an appropriate solvent treatment.

FIG. 1 is a sectional view showing an example of the image forming apparatus of the present invention. In FIG. 1, reference numeral 50 denotes a photoreceptor drum (photoreceptor) serving as an image carrier, which is a photoreceptor having an organic photosensitive layer applied on the drum and a resin layer of the present invention applied thereon, and is grounded clockwise. Is driven to rotate. Reference numeral 52 denotes a scorotron charger, which applies uniform charge to the peripheral surface of the photosensitive drum 50 by corona discharge. Prior to the charging by the charger 52, in order to eliminate the history of the photoconductor in the previous image formation, exposure by the exposure unit 51 using a light emitting diode or the like may be performed to eliminate the charge on the peripheral surface of the photoconductor.

After the photosensitive member is uniformly charged, image exposure based on the image signal is performed by the image exposure device 53. The image exposure device 53 in this figure uses a laser diode (not shown) as an exposure light source. The light on the photosensitive drum is scanned by the light whose optical path is bent by the reflection mirror 542 via the rotating polygon mirror 531 and the fθ lens and the like, and an electrostatic latent image is formed.

The electrostatic latent image is then developed in a developing unit 54. A developing device 54 having a built-in developer composed of toner and carrier is provided around the periphery of the photosensitive drum 50.
The developing is performed by a developing sleeve 541 that has a built-in magnet and rotates while holding the developer. The developer is, for example, a carrier in which an insulating resin is coated around the above-described ferrite as a core, a colorant such as carbon black, a charge control agent, and a low molecular weight polyolefin of the present invention using the above-mentioned styrene acrylic resin as a main material. The toner is a toner in which silica, titanium oxide, or the like is externally added to colored particles made of, and the developer is regulated to a layer thickness of 100 to 600 μm on the developing sleeve 541 by the layer forming means, and is conveyed to the developing area. , And development is performed. At this time, development is usually performed by applying a DC bias voltage between the photosensitive drum 50 and the developing sleeve 541 and, if necessary, an AC bias voltage. The developer is developed in a state of contact or non-contact with the photoconductor.

After the image is formed, the recording paper P is fed to the transfer area by the rotation of the paper feed roller 57 at the time when the transfer timing is adjusted.

In the transfer area, a transfer roller (transfer device) is mounted on the peripheral surface of the photosensitive drum 50 in synchronization with the transfer timing.
58 is pressed and transferred while sandwiching the fed recording paper P.

Next, the recording paper P is neutralized by a separation brush (separator) 59 which is brought into pressure contact with the transfer roller almost simultaneously, is separated by the peripheral surface of the photosensitive drum 50, is conveyed to the fixing device 60, and is heated by the heat roller. After the toner is welded by heating and pressing the 601 and the pressure roller 602, the toner is discharged to the outside of the apparatus via the discharge roller 61. The transfer roller 58 and the separation brush 59 are provided on the recording paper P.
After passing through, the photosensitive drum 50 is retracted and separated from the peripheral surface thereof to prepare for the formation of the next toner image.

On the other hand, the photosensitive drum 50 from which the recording paper P has been separated removes and cleans the residual toner by pressing the blade 621 of the cleaning device 62, and receives the charge removal by the exposure unit 51 and the charge by the charger 52 again. The next image forming process is started.

Reference numeral 70 denotes a detachable process cartridge in which a photosensitive member, a charging device, a transfer device / separator, and a cleaning device are integrated.

An electrophotographic image forming apparatus is constructed by integrally combining the above-described photosensitive member, a developing device, a cleaning device, and other components as a process cartridge, and this unit is configured to be detachable from the apparatus main body. You may.
Also, a process cartridge is formed by integrally supporting at least one of a charger, an image exposing unit, a developing unit, a transfer or separating unit, and a cleaning unit together with a photoreceptor. It may be configured to be detachable using a guide means such as a rail of the apparatus body.

The process cartridge generally includes an integral type cartridge and a separate type cartridge described below. The integral type cartridge is configured such that at least one of a charger, an image exposing unit, a developing unit, a transfer or separating unit, and a cleaning unit is integrally formed with a photoconductor, and is detachable from an apparatus main body. Are a charging device, an image exposure device, a developing device, a transfer or separation device, and a cleaning device which are configured separately from the photoreceptor, but have a configuration detachable from the apparatus main body and are incorporated in the apparatus main body. When integrated, it is integrated with the photoconductor. The process cartridge in the present invention includes both types of cartridges.

Further, the image forming apparatus may have a form in which a process cartridge including a photosensitive drum and at least one of a charging device, a developing device, a cleaning device, and a recycling member is mounted.

The transfer paper is typically plain paper, but is not particularly limited as long as it can transfer an unfixed image after development, and of course includes a PET base for OHP.

In the image exposure, when the electrophotographic image forming apparatus is used as a copier or a printer, the reflected light or transmitted light from the original is irradiated on the photosensitive member, or the original is read by a sensor to be converted into a signal. Scanning of a laser beam, driving of an LED array, or driving of a liquid crystal shutter array according to a signal is performed by irradiating light to a photoconductor.

When used as a facsimile printer, the image exposure unit 53 performs exposure for printing received data.

The electrophotographic photoreceptor of the present invention can be applied to general electrophotographic devices such as copiers, laser printers, LED printers, and liquid crystal shutter printers. It can be widely applied to devices such as light printing, plate making, and facsimile.

Next, synthesis examples of the perylene hybrid pigment of the present invention and the pigment of the comparative example are shown below. Synthesis Example 1 0.3 g of titanyl phthalocyanine and 30 g of the compound (1) bisimidazole perylene were added to 900 ml of concentrated sulfuric acid at room temperature, and further stirred for 2 hours. The sulfuric acid solution was filtered through a glass filter to remove insolubles, and then poured into 15 liters of water while maintaining the water temperature at 30 ° C. or lower. After the precipitated particles were filtered, they were further washed three times with 5 liters of water. The wet cake obtained by the filtration was once frozen, thawed, filtered and dried to obtain 28 g of a perylene hybrid pigment (1).

Synthesis Example 2 26.5 g of perylene hybrid pigment (2) was obtained in the same manner as in Synthesis Example 1 except that 0.1 g of vanadium oxyphthalocyanine was used instead of titanyl phthalocyanine.

Synthesis Example 3 27 g of perylene mixed pigment (3) was obtained in the same manner as in Synthesis Example 1 except that 0.15 g of hydroxygallium phthalocyanine was used instead of titanyl phthalocyanine.

Synthesis Example 4 In the same manner as in Synthesis Example 1 except that 0.3 g of copper phthalocyanine was used instead of titanyl phthalocyanine, 27 g of perylene hybrid pigment (4) was obtained.

Synthesis Example 5 (Comparative Synthesis Example) Synthesis Example 1 except that the amount of titanyl phthalocyanine was 3 g
In the same manner as in the above, 29.5 g of a hybrid pigment (5) was obtained.

Synthesis Example 6 (Comparative Synthesis Example) A perylene hybrid pigment (6) was produced in the same manner as in Synthesis Example 1 except that metal-free phthalocyanine was used instead of titanyl phthalocyanine.

Synthesis Example 7 (Comparative Synthesis Example) A perylene pigment (1) was prepared in the same manner as in Synthesis Example 1 except that titanyl phthalocyanine was omitted, and the perylene pigment (1) was 25.8.
g was obtained.

Cu-Kα Characteristic X of Each Pigment of Synthesis Examples 1 to 5
Table 1 shows the presence or absence of a change in the diffraction angle by X-ray diffraction analysis using X-rays (based on the X-ray diffraction angle of the perylene pigment (1) of Synthesis Example 7), the presence or absence of a metal atom, and the content thereof.

[0085]

[Table 1]

X-Ray Diffraction Measurement The coating solution for the charge generation layer (the pigment in the description is the pigment to be measured) is prepared by the method described in Preparation of Photoreceptor 1 in which the perylene-mixed pigment particles and the perylene pigment of Synthesis Examples 1 to 7 are described later. Was dispersed, and then applied and dried, and the powder X-ray diffraction of a coating film having a thickness of about 1 mm was measured. FIG. 2 is a powder X-ray diffraction diagram of the perylene hybrid pigment (1) shown in Synthesis Example 1, FIG. 3 is a powder X-ray diffraction diagram of the perylene hybrid pigment (5) shown in Synthesis Example 5,
FIG. 4 shows a powder X-ray diffraction diagram of the perylene pigment (1) shown in Synthesis Example 7.

Method for Confirming the Presence or Absence of Metal Atom The metal atom in the perylene hybrid pigment of the present invention is determined by X-ray fluorescence
DX), atomic absorption spectrometry, ICP and the like, the presence or absence of metal atoms and the content thereof can be measured.

[0088]

EXAMPLES The present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In this example, “parts” means “parts by mass”.

Preparation of Photoreceptor 1 On a PET film on which aluminum was deposited, an intermediate layer having a thickness of about 0.5 μm made of copolymerized nylon CM8000 (manufactured by Toray Industries, Inc.) was provided using a wire bar. 1.5 parts of perylene hybrid pigment (1), 0.5 part of butyral resin, 10 parts of cyclohexanone, 40 parts of 2-butanone
A portion of the coating solution was dispersed using a sand mill and the coating solution for the charge generation layer was applied using a wire bar to form a charge generation layer having a dry film thickness of about 0.3 μm. Next, a solution prepared by dissolving 0.65 part of a carrier transporting substance (exemplified compound T-6) and 1 part of a polycarbonate resin “Iupilon-Z200” (manufactured by Mitsubishi Gas Chemical Co., Ltd.) in 7.5 parts of dichloroethane was placed on the charge generating layer. The resultant was coated with a blade to form a charge transporting layer having a dry film thickness of about 24 μm.

Preparation of Photoreceptors 2 to 7 The photoreceptors 2 to 7 were prepared in the same manner as the photoreceptor 1 except that the perylene composite pigment (1) was replaced by the perylene composite pigments 2 to 7 of the synthesis examples shown in Table 1 or the perylene pigments. To 7 were produced.

Preparation of Photoreceptor 8 Coating Nylon CM8000 (manufactured by Toray Industries, Inc.) by dip coating on a cylindrical aluminum substrate 2.7
An intermediate layer of mg / 100 cm ² was provided. On top of this, 1.5 parts of perylene-mixed pigment (1), butyral resin 0.5
, 10 parts of cyclohexanone and 40 parts of 2-butanone were dip-coated using a sand mill, and the wavelength was 680.
A charge generation layer having an absorbance in nm of about 1.1 was formed. Next, a solution prepared by dissolving 0.65 part of a carrier transporting agent (compound A) and 1 part of a polycarbonate resin “Iupilon-Z200” (manufactured by Mitsubishi Gas Chemical Co., Ltd.) in 7.5 parts of dichloroethane was applied onto the charge generation layer by dip coating. A charge transport layer having a dry film thickness of about 24 μm was formed to produce a photoreceptor 8 (the photoreceptor 8 has basically the same prescription as the photoreceptor 1 except for the conductive substrate).

Preparation of Photoconductors 9 to 13 Photoconductors 8 were prepared except that perylene-mixed pigment (1) was replaced with perylene-mixed pigments (2) to (6).
In the same manner as in the above, photosensitive members 9 to 13 were produced.

Evaluation 1 The following evaluation was performed to confirm the stability of the photosensitive member characteristics during exposure to a large amount of light.

The photosensitive members 1 to 7 were exposed for a predetermined period of time at a distance of 5 cm from a 100 V / 60 W white light source. The electrophotographic characteristics before and after exposure were evaluated using a paper analyzer EPA8100 (manufactured by Kawaguchi Electric Co., Ltd.). Potential Va after charging, surface potential from -500V to -5
Required light amount E500 / 50 (lu) for attenuating to 0V
x · sec) is shown in Table 2.

[0095]

[Table 2]

As is clear from the results shown in Table 2, photoreceptor group 1 using the perylene hybrid pigment of the present invention as a charge generating agent
-4 are photoreceptor groups 5-7 outside the present invention after exposure to a large amount of light.
In contrast, the change ΔVa in the charging potential (Va) was small, and the change ΔE in the photosensitivity E500 / 50 was also improved to less than half that of the comparative photoconductor group.

Evaluation 2 The following evaluation was performed to confirm the image stability of repeated copying.

Digital copying machine Konica 7050
(Charging polarity: negative, reversal development, 680 nm light source) Using a modified machine, a real copy of 44,000 A3-size copies was made in an environment of a temperature of 24 to 28 ° C. and a humidity of 54 to 84% RH. 3. Repeated initial copy image using photoconductors 8 to 14
The images after the copying of 40,000 sheets were evaluated focusing on the following points.

White background fog: An image defect in which toner is originally developed on the entire white background due to a decrease in charged (white background) potential (VH).

Intermediate density change: An image defect in which the initial image density cannot be reproduced because the potential of the electrostatic latent image on the photoreceptor surface changes due to a change in the sensitivity or the like of the photoreceptor. Charge (white background) potential (V
H) and an intermediate potential (V) between the darkest image density potential (VL).
M) shows a change in density (intermediate density) corresponding to (M).

First copy image: Indicates the image state of the first rotation of the photosensitive member. Table 3 shows the results.

[0102]

[Table 3]

In the image of the first copy in which the image of the first rotation of the photosensitive member appears, the density of the photosensitive member 12 is reduced.
Then, white background fog has occurred. On the other hand, with the photoconductors 8 to 11 of the present invention, good images were obtained from the first copy.

Evaluation 3 The stability of the copied image in a low temperature and low humidity environment was evaluated by the following method.

Following the evaluation 2, Konica 7050
(Charging polarity: negative, reversal development, 680 nm light source) Using a modified machine, 40,000 A3 size copies were actually photographed under an environment of a temperature of 11 ° C. and a humidity of 11% RH. Evaluation items and evaluation criteria are the same as evaluation 2.

Table 4 shows the results.

[0107]

[Table 4]

As can be seen from this, image defects were confirmed in the photoreceptors 12 and 13 by initial or repeated copying, but the photoreceptors 8 to 11 of the present invention showed good initial and repeated copying even in a low-temperature and low-humidity environment. A copy image was stably achieved.

Evaluation 4 The stability of a copied image in a high-temperature, high-humidity environment was evaluated by the following method.

Following evaluation 3, Konica 7050
(Charge polarity: negative, reversal development, 680 nm light source) Using a modified machine, 40,000 A3-size copies were actually photographed under an environment of a temperature of 30 ° C. and a humidity of 82% RH. Evaluation items and evaluation criteria are the same as evaluation 2.

Evaluation was made on the charging (white background) potential (VH), the darkest image density potential (VL), the intermediate potential (VM), and ΔV (the difference between the VH at the first rotation and the second rotation of the photosensitive member).

Table 5 shows the results.

[0113]

[Table 5]

As can be seen from this, image defects were confirmed in the photoreceptors 12 and 13 by initial or repeated copying, but the photoreceptors 8 to 11 of the present invention could stably produce a good copied image even in a high temperature and high humidity environment. Achieved.

[0115]

From the results of the evaluations 1 to 4, the following performances were greatly improved by the photoreceptors of Examples using the hybrid pigment of the present invention as a charge generating substance, as compared with conventional photoreceptors. 1) There is little deterioration in sensitivity during exposure to a large amount of light. 2) Even after continuous use, there is little difference in chargeability between the first and second rotations of the photoconductor.

By improving these characteristics, it was possible to provide a stable copy image in all of high light exposure, repeated use, low temperature and low humidity environment, and high temperature and high humidity environment. Under the same conditions, a good copied image was obtained even when the image was formed at the first rotation of the photoconductor. Conventional photoreceptors produce defects in the copied image under any of the conditions.

As described above, a stable copy image can be obtained in various environments and processes by using the electrophotographic photosensitive member using the hybrid pigment of the present invention as a charge generating substance.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view as an example of an image forming apparatus of the present invention.

FIG. 2 is a powder X-ray diffraction diagram of a perylene hybrid pigment (1) shown in Synthesis Example 1.

FIG. 3 is a powder X-ray diffraction chart of a perylene hybrid pigment (5) shown in Synthesis Example 5.

FIG. 4 is a powder X-ray diffraction chart of the perylene pigment (1) shown in Synthesis Example 7.

[Explanation of symbols]

 Reference Signs List 50 photoreceptor drum (or photoreceptor) 51 exposure unit 52 charger 53 image exposure unit 54 developing unit 57 paper feed roller 58 transfer roller (transfer unit) 59 separation brush (separator) 60 fixing device 61 paper discharge roller 62 cleaning device 70 process cartridge

Claims (11)

[Claims] 1. An X-ray diffraction pattern of a hybrid pigment obtained by mixing one or more metal atom-containing compounds with a metal-free pigment is substantially the same as the X-ray diffraction pattern of the metal-free pigment. Hybrid pigments. 2. The method according to claim 2, wherein the metal atom of the hybrid pigment is Ti, Cu,
The hybrid pigment according to claim 1, wherein the composite pigment is at least one selected from Fe, V, Ga, Si, Pb, Al, Zn, and Mg. 3. The hybrid pigment having a metal atom content of 50 p
3. The hybrid pigment according to claim 1, wherein the content is from pm to 10000 ppm. 4. 4. The hybrid pigment according to claim 1, wherein the metal atom-containing compound is a metal phthalocyanine compound. 5. The hybrid pigment according to claim 4, wherein the content of the metal phthalocyanine compound in the hybrid pigment is 0.01 to 10% by mass. 6. The hybrid pigment according to claim 1, wherein the hybrid pigment contains a perylene compound as a main component. 7. The hybrid pigment according to claim 6, wherein the perylene compound is a bisimidazole perylene of the compound (1) represented by the following structure. Embedded image 8. A method for producing a hybrid pigment, comprising producing the hybrid pigment according to any one of claims 1 to 7 by acid paste treatment. 9. An electrophotographic photoreceptor comprising the hybrid pigment according to claim 1. Description: 10. An image forming apparatus having at least each of charging, image exposing, developing, and transferring means around an electrophotographic photosensitive member, wherein an image is formed using the electrophotographic photosensitive member according to claim 9. Characteristic image forming apparatus. 11. A process cartridge used in an image forming apparatus having at least each of charging, image exposure, development, and transfer means around an electrophotographic photosensitive member, wherein the process cartridge is the electrophotographic photosensitive member according to claim 9. And at least one of a charging unit, an image exposing unit, a developing unit, and a transferring unit, and is designed to be freely inserted into and removed from the image forming apparatus.