JP2002296817A - Electrophotographic photoreceptor, method for producing the same, and process cartridge and electrophotographic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor having superior electrophotographic characteristics and superior durability, ensuring a small photo memory, less liable to form a ghost and excellent in image stability and to provide a method for producing the photoreceptor, and a process cartridge and an electrophotographic apparatus. SOLUTION: In the electrophotographic photoreceptor having at least an electric charge generating layer and an electric charge transporting layer on an electrically conductive substrate, the electric charge generating layer is formed using a dispersion prepared by dispersing oxy-titanium phthalocyanine crystals having strong peaks at 9.0 deg., 14.2 deg., 23.9 deg. and 27.1 deg. Bragg angles (2θ±0.2 deg.) in characteristic X-ray diffraction of CuKα in a solvent containing 0.1 to <1 part by mass of water based on 1 part by mass of the crystals. And its manufacturing method and a process cartridge and an electrophotographic apparatus are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrophotographic photoreceptor,
More specifically, the present invention relates to a method for manufacturing an electrophotographic photosensitive member, a process cartridge, and an electrophotographic apparatus. More specifically, an electrophotographic photosensitive member having a charge generation layer and a charge transport layer containing oxytitanium phthalocyanine, a method for manufacturing an electrophotographic photosensitive member, and an electrophotographic image thereof. The present invention relates to a process cartridge having a photoconductor and an electrophotographic apparatus.

[0002]

2. Description of the Related Art In recent years, organic photoconductive materials have been actively studied for use in electrophotographic photosensitive members because of their advantages such as high safety, suitability for mass production, and low cost. Photoconductors have been proposed and put to practical use. These electrophotographic photosensitive members are widely used not only in copying machines but also in laser beam printers using a semiconductor laser as a light source.

At present, a semiconductor laser mainly used has an emission wavelength of 790 ± 20 nm, and an electrophotographic photosensitive member having sufficient sensitivity in this wavelength region is being developed. As a typical charge generation material, phthalocyanine and the like can be mentioned, and among them, highly sensitive oxytitanium phthalocyanine has been studied in many cases. Many crystal forms of oxytitanium phthalocyanine, like other phthalocyanines, are known. For example, JP-A-61-239
248, JP-A-62-67094, JP-A-1-17066, JP-A-3-54264, and JP-A-3-128973.

[0004] However, these oxytitanium phthalocyanines have a high residual potential, and have a low endurance stability, such as a decrease in the charged potential and a change in the light portion potential due to repetition of image forming processes such as charging, exposure, development and transfer. But not enough.

Also, when exchanging the electrophotographic photosensitive member or the process cartridge or removing paper jams (jam), if light such as a fluorescent lamp hits the electrophotographic photosensitive member, a photo memory is generated in that portion to cause image unevenness. The conventional electrophotographic photoreceptor has never been sufficient for these defects.

In recent years, laser beam printers have no charge elimination (pre-exposure) process, and it is difficult for the exposed light portion to carry a sufficient electric potential by the next charging, so that a halftone image or the like can be output and one rotation before the electrophotographic photosensitive member. A ghost occurs in which the history of the exposed light portion and the non-exposed light portion appears as unevenness on the halftone image. In a reversal developing system, a positive ghost occurs in which the image density of the exposed light one cycle before the electrophotographic photosensitive member is higher than that of the non-exposed light portion, and these phenomena can be sufficiently suppressed with the conventional electrophotographic photosensitive member. Did not.

[0007] Further, to solve the problem that the crystal form of oxytitanium phthalocyanine is liable to change and the good properties are impaired, the crystal form can be maintained by dispersing the oxytitanium phthalocyanine crystal with a solvent containing water in an amount equal to or more than the equivalent amount of the oxytitanium phthalocyanine crystal. This is reported in Japanese Patent No. 2532795.
However, it was not sufficient in terms of image stability such as a photo memory and a ghost.

It is known that an antioxidant, an acceptor compound, or the like is added to a photosensitive layer in order to improve the durability of an electrophotographic photosensitive member, reduce memory, and the like. For example, JP-A-62-265666, JP-A-63-50848, JP-A-64-44451, JP-A-3-170941, and JP-A-4-512.
No. 48, JP-A-5-127400, JP-A-5-127400
JP-A-127402, JP-A-8-262755, JP-A-9-106085, and the like.

However, even with these electrophotographic photosensitive members, an electrophotographic photosensitive member satisfying all of initial characteristics, durability characteristics, photo memory, ghost, and the like has not been obtained at present.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic photosensitive member having excellent electrophotographic characteristics and excellent durability, and a method for producing the electrophotographic photosensitive member.

Another object of the present invention is to provide an electrophotographic photosensitive member having a small photo memory and excellent in image stability in which ghost is hardly generated, and a method of manufacturing the electrophotographic photosensitive member.

Still another object of the present invention is to provide a process cartridge and an electrophotographic apparatus having the above electrophotographic photosensitive member.

[0013]

According to the present invention, in an electrophotographic photoreceptor having at least a charge generation layer and a charge transport layer on a conductive support, the charge generation layer has a Bragg angle (CuKα) in characteristic X-ray diffraction. Oxytitanium phthalocyanine crystal having strong peaks at 9.0 °, 14.2 °, 23.9 ° and 27.1 ° (2θ ± 0.2 °) was added in an amount of 0.1 part by mass with respect to 1 part by mass of the crystal. The present invention provides an electrophotographic photoreceptor formed by using a dispersion liquid which is subjected to a dispersion treatment with a solvent containing water in an amount of at least 1 part by mass and less than 1 part by mass, and a method for producing the electrophotographic photoreceptor.

Further, according to the present invention, there is provided a process cartridge and an electrophotographic apparatus having the above electrophotographic photosensitive member.

[0015]

Embodiments of the present invention will be described below in detail.

The oxytitanium phthalocyanine used in the present invention is represented by the following structural formula.

[0017]

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Wherein X ¹ , X ² , X ³ and X ⁴ are Cl or B
r is shown, and n, m, l, and k are integers of 0-4.

Examples of the binder resin include polyvinyl butyral resin, polyester resin, acrylic resin, phenoxy resin, polycarbonate resin, polyvinyl acetal resin, polystyrene resin, and polyarylate resin. It is preferable in terms of properties.

The dispersion solvent may be a mixed solvent of an organic solvent and water, and the organic solvent is preferably a hydrophilic one such as tetrahydrofuran, n-propyl ether,
Among them are ether solvents such as n-butyl ether and 1,4-dioxane, alcohol solvents such as methanol, ethanol, propanol and 2-methoxyethanol, and ketone solvents such as acetone, methyl ethyl ketone and cyclohexanone. Tetrahydrofuran is particularly preferred.

The amount of the solvent used and the composition of the mixture are as follows: 1 part by mass of oxytitanium phthalocyanine,
Not less than 160 parts by mass, especially 1 part by mass of oxytitanium phthalocyanine, the organic solvent is preferably not less than 20 parts by mass and not more than 80 parts by mass, and the mixed solvent having a water content of not less than 0.1 part by mass and less than 1 part by mass. preferable. This dispersion may be used as it is as a coating solution for the charge generation layer, or may be used by mixing with another organic solvent.

In the dispersion treatment, for example, a milling device such as a paint shaker, a sand mill, a ball mill, or the like, a homogenizer, an ultrasonic dispersion or a high-pressure liquid collision dispersion device is used together with a dispersion medium such as glass beads, steel beads, and alumina balls. This is the process to be performed.

Japanese Patent Application Laid-Open Nos. 10-183007 and 11-1628 disclose an oxytitanium phthalocyanine having a specified peak intensity ratio of 24.0 ° / 27.2 ° in characteristic X-ray diffraction. However, these are different from the manufacturing method of the present invention in that the effects of the present invention, in particular, the effect of reducing the photo memory and the positive ghost are not obtained, and the potential fluctuation due to the environment is large.

The dithiobenzyl compound represented by the formula (1) for use in the present invention can be prepared by a known method, for example, as described in Journal.
al of American Chemical S
chemistry, 87, 1483 (1965).

[0025]

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In the formula, R ₁ , R ₂ , R ₃ and R ₄ are the same or different and each represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group or a cyano group. Show. M is Ni, Pt, Pd,
Co, Cu, Fe, Zn, Cr, Rh, Sn, Zr, T
Indicates i, Ru, Os, Re, Mo, W or V.

In the dioctylbenzyl compound, M is N
i, Pt, Pd, Co, Cu and Fe are preferred;
R ₁ , R ₂ , R ₃ and R ₄ are more preferably aryl groups.

In the dithiobenzyl compound represented by the formula (1), the alkyl group includes a methyl group, an ethyl group, a propyl group and a butyl group, and the aryl group includes a phenyl group, a naphthyl group and a pyrenyl group. And
Examples of the aralkyl group include a benzyl group and a phenethyl group.

Examples of the substituent which these groups may have include alkyl groups such as methyl group, ethyl group, propyl group and butyl group, alkoxy groups such as methoxy group and ethoxy group, aryl groups such as phenyl group, and the like. Examples include an amino group such as a dimethylamino group, a diethylamino group, and a diphenylamino group, a nitro group, and a cyano group.

Preferred examples of the ditylbenzyl compound represented by the formula (1) are shown below, but the present invention is not limited thereto.

[0031]

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[0032]

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[0033]

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[0034]

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[0035]

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[0036]

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[0037]

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[0038]

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[0039]

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Hereinafter, an electrophotographic photoreceptor using the charge generation layer containing oxytitanium phthalocyanine of the present invention will be described.

First, FIG. 1 shows a typical representative layer structure of an electrophotographic photosensitive member. An example is shown in which the photosensitive layer 1 has a laminated structure of a charge generation layer 2 containing a charge generation material and a charge transport layer 3 containing a charge transport material. Reference numeral 4 denotes a conductive support. The stacking relationship between the charge generation layer and the charge transport layer may be reversed.

In the case of producing an electrophotographic photoreceptor, the support may be any as long as it has conductivity, and a metal such as aluminum, copper, chromium, nickel, zinc and stainless steel, or a metal foil such as aluminum or copper is made of plastic. Laminated, aluminum, indium oxide or tin oxide deposited on plastic, or conductive metal, alumite-treated aluminum, plastic, paper, etc., in the form of a cylinder or film And the like.

When the exposure light such as LBP is a laser beam, a conductive layer may be provided on the support for the purpose of preventing interference fringes due to scattering or covering the support.
This can be formed by dispersing a conductive powder such as carbon black or metal particles in a binder resin. The thickness of the conductive layer is preferably 5 to 40 μm, particularly 10 to 3 μm.
0 μm is preferred.

Further, an undercoat layer having a barrier function and an adhesive function can be provided between the support and the photosensitive layer.
Examples of the material of the undercoat layer include polyvinyl alcohol, polyethylene oxide, ethyl cellulose, methyl cellulose, casein, polyamide, glue, gelatin and the like. These are dissolved in an appropriate solvent and applied on a conductive support. Its thickness is 0.2 to 3.0 μm.

The charge generation layer is formed by applying a dispersion obtained by dispersing the oxytitanium phthalocyanine of the present invention together with the binder resin and a dispersion solvent containing water, followed by drying.

The ratio of the oxytitanium phthalocyanine to the binder resin in the charge generation layer is from 10: 1 to 10 by mass.
1: 5 is preferred, and especially 5: 1 to 1: 2 is preferred.

The dithiobenzyl compound may be added before (pre-addition) or after addition (post-addition) of the charge-generating material.
Pre-addition is more preferred. The mixing ratio of the charge generating material and the dithiobenzyl compound is preferably 0.03 to 50 parts by weight, and particularly preferably 0.1 to 20 parts by weight, based on 100 parts by weight of the charge generating material. The thickness of the charge generation layer is preferably from 0.01 to 5 μm, and particularly preferably from 0.05 to 1 μm.

The charge transport layer is formed by coating and drying a coating solution in which a charge transport material and a binder resin are dissolved in a solvent. Examples of the charge transport material to be used include various triarylamine compounds, hydrazone compounds, stilbene compounds, pyrazoline compounds, oxazole compounds, thiazole compounds, and trialinemethane compounds.

As the binder resin, polyester resin, acrylic resin, polyvinyl carbazole resin, phenoxy resin, polycarbonate resin, polyvinyl butyral resin, polystyrene resin, polyvinyl acetate resin, polysulfone resin, polyarylate resin,
And vinylidene chloride and acrylonitrile copolymer resins. The thickness of the charge transport layer is preferably 5 to 40 μm, particularly preferably 10 to 30 μm.

Further, a thin protective layer may be provided on the surface of the photosensitive layer in order to protect these photosensitive layers from external impact.

Methods for forming these layers such as the undercoat layer, the charge generation layer, the charge transport layer and the protective layer include dip coating, spray coating, spinner coating, roller coating, wire bar coating, and the like. Examples thereof include a blade coating method, but are not limited thereto.

FIG. 2 shows a schematic configuration of an electrophotographic apparatus provided with a process cartridge having the electrophotographic photosensitive member of the present invention.

In FIG. 2, reference numeral 11 denotes a drum-shaped electrophotographic photosensitive member of the present invention, which is driven to rotate around a shaft 12 in a direction of an arrow at a predetermined peripheral speed. In the rotation process, the peripheral surface of the electrophotographic photoreceptor 11 is uniformly charged with a predetermined positive or negative potential by the primary charging means 13, and then, exposure means (not shown) such as slit exposure and laser beam scanning exposure
Receives exposure light 14 whose intensity is modulated in accordance with the time-series electric digital image signal of the target image information output from.
In this way, an electrostatic latent image corresponding to the target image information is sequentially formed on the peripheral surface of the electrophotographic photosensitive member 11.

The formed electrostatic latent image is then transferred to developing means 1
5, the toner image is developed between the electrophotographic photosensitive member 11 and the transfer means 16 from a paper feeding unit (not shown).
Transfer material 17 taken out and fed in synchronization with the rotation of
Then, the toner image formed and carried on the surface of the electrophotographic photosensitive member 11 is sequentially transferred by the transfer unit 16.

The transfer material 17 to which the toner image has been transferred is
After being separated from the surface of the electrophotographic photosensitive member and introduced into the image fixing means 18 and subjected to image fixing, the image is printed out of the apparatus as an image formed product (print, copy).

The surface of the electrophotographic photosensitive member 11 after the image transfer is
The transfer residual toner is removed by the cleaning unit 19 to make the surface clean and used repeatedly for image formation.

In the present invention, among the above-mentioned components such as the electrophotographic photoreceptor 11, the primary charging means 13, the developing means 15, and the cleaning means 19, a plurality of components are housed in a container and integrally combined as a process cartridge. The process cartridge may be configured to be detachable from an electrophotographic apparatus body such as a copying machine or a laser beam printer. For example, at least one of the primary charging unit 13, the developing unit 15, and the cleaning unit 19 is integrally supported with the electrophotographic photoreceptor 11 to form a cartridge, and is attached to and detached from the apparatus main body by using a guide unit 22 such as a rail of the apparatus main body. A flexible process cartridge 21 can be provided.

When the electrophotographic apparatus is a copying machine or a printer, the exposure light 14 is reflected or transmitted from the original, or the original is read by a sensor and converted into a signal.
Laser beam scanning performed according to this signal, LE
The light is emitted by driving the D array or driving the liquid crystal shutter array.

The electrophotographic photosensitive member of the present invention can be used not only for an electrophotographic copying machine but also for a laser beam printer,
It can be widely used in electrophotographic applications such as CRT printers, LED printers, faxes, liquid crystal printers, and laser plate making.

[0060]

The present invention will be described in more detail with reference to the following examples. In the examples, “parts” means “parts by mass”.

The measurement of X-ray diffraction was carried out using CuKα radiation under the following conditions.

Measuring machine used: Mac Science Co., Ltd., fully automatic X-ray diffractometer MXP18 X-ray tube: Cu Tube voltage: 50 kV Tube current: 300 mA Scanning method: 2θ / θ scan Scan speed: 2 deg./min Sampling interval : 0.020 deg. Start angle (2θ): 5 deg. Stop angle (2θ): 40 deg. Divergence slit: 0.5 deg. Scattering slit: 0.5 deg. Receiving slit: 0.3mm curved monochromator used

(Example 1) 50 parts of titanium oxide powder coated with tin oxide containing 10% antimony oxide, 25 parts of resole type phenol resin, methoxypropanol 30
Parts, 30 parts of methanol and 0.002 part of silicone oil (polydimethylsiloxane polyoxyalkylene copolymer, weight average molecular weight 3000) were dispersed in a sand mill using 1 mmφ glass beads for 2 hours to prepare a coating liquid for a conductive layer. This coating solution was applied on a 30 mmφ aluminum cylinder by a dip coating method.
Drying was performed at 30 ° C. for 30 minutes to form a conductive layer having a thickness of 20 μm.

Next, a solution prepared by dissolving 5 parts of a polyamide resin (trade name: Amilan CM8000, manufactured by Toray) in a mixed solvent of 70 parts of methanol / 25 parts of butanol was applied on the conductive layer by dip coating. After drying, an undercoat layer having a thickness of 0.5 μm was formed.

Next, as a charge generating material, CuKα has a Bragg angle (2θ ± 0.2 °) of 9.0 in characteristic X-ray diffraction.
°, 14.2 °, 23.9 ° and 27.1 °, using 10 parts of oxytitanium phthalocyanine (X-ray diffraction pattern is FIG. 3) having strong peaks at 10 ° C. and polyvinyl butyral (trade name: Eslek BX-1, Sekisui Chemical Co., Ltd.) was dissolved in a mixed solvent of tetrahydrofuran: water = 97: 3 to prepare a 5% by mass solution of 166 parts, and a mixed solvent of tetrahydrofuran: water = 97: 3 was 150 parts, each of which was 1 mm.
Using 400 parts of φ glass beads, dispersion treatment was performed for 4 hours by a sand mill device. The ratio of water to the oxytitanium phthalocyanine crystal during the dispersion treatment was 0.92 parts per part of the crystal. Then, tetrahydrofuran: water =
97: 3 mixed solvent of 210 parts and cyclohexanone 2
60 parts were added and diluted to prepare a coating solution for the charge generation layer (the X-ray diffraction diagram is FIG. 4). This coating solution was applied on the undercoat layer by a dip coating method, and dried at 95 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.2 μm.

Next, 9 parts of a compound represented by the following structural formula as a charge transporting material,

[0067]

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One part of a compound represented by the following structural formula

[0069]

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And 10 parts of polycarbonate (trade name: Iupilon Z-400, manufactured by Mitsubishi Gas Chemical Co.) were dissolved in a mixed solvent of 40 parts of dichloromethane / 60 parts of monochlorobenzene, and this solution was dip-coated on the charge generation layer. And dried at 115 ° C. for 60 minutes.
A 5 μm charge transport layer was formed to produce an electrophotographic photoreceptor.

The electrophotographic photosensitive member produced in this manner was used as a laser beam printer (trade name: LaserW).
writer 16/600 ps, manufactured by Apple Inc.) and charged so that the dark part potential (Vd) becomes -700 V, and irradiating the laser light with a wavelength of 780 nm to the light part potential (Vl) to -150 V The amount of light required to achieve was determined as the sensitivity.

Further, a repetitive image output durability test was performed on 5,000 sheets, and the variations (ΔVd and ΔVl) of the dark portion potential and the bright portion potential at the initial stage and immediately after the endurance were measured.

Further, the first rotation (94.2) of the electrophotographic photosensitive member is performed.
mm length), an image having a solid white image (entirely unexposed, Vd) portion and a solid black image (entirely exposed, Vl) portion is output. Ghost in (The trace of the image on the first rotation of the electrophotographic photosensitive member is 2
The presence or absence of the phenomenon (a phenomenon appearing densely in the image on the lap) and the degree thereof (the image density difference between the trace of the image on the first lap and the normal halftone portion) were visually evaluated before and after the durability test.

Further, a part of the electrophotographic photosensitive member is shielded from light, the unshielded portion is irradiated with a 1500 Lux fluorescent light for 5 minutes, and then the entire electrophotographic photosensitive member is shielded for 5 minutes. , And the potential of the bright portion was measured, and the potential difference ΔV1 between the non-light-shielding portion and the light-shielding portion was evaluated as a photo memory (PM).

ΔVl (PM) = | non-light-shielding portion Vl | − | light-shielding portion Vl | Note that a negative value of the amount of change in the potential indicates that the absolute value of the potential has decreased.

Positive ghosts are visually evaluated as follows: o = none, Δ = slightly present, x = presented. Table 1 shows the results.

Example 2 An electrophotographic photosensitive member was prepared in the same manner as in Example 1, except that 1,4-dioxane was used in place of the solvent tetrahydrofuran in the coating solution for the charge generation layer. An evaluation was performed. Table 1 shows the results.

Example 3 An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that cyclohexanone was used in place of the solvent tetrahydrofuran in the coating solution for the charge generation layer. . Table 1 shows the results.

Example 4 Example 1 was carried out in the same manner as in Example 1 except that the ratio of tetrahydrofuran: water in the mixed solvent of the coating solution for the charge generation layer was changed from 97: 3 to 99: 1. An electrophotographic photoreceptor was prepared and evaluated. The ratio of water to the oxytitanium phthalocyanine crystal during the dispersion treatment was 0.31 part with respect to 1 part of the crystal. Table 1 shows the results.

Example 5 In Example 1, the dithiobenzyl compound S-13 was dispersed at the time of dispersing the coating solution for the charge generation layer.
Was prepared and evaluated in the same manner as in Example 1, except that 0.1 part of was added and dispersed. Table 1 shows the results
Shown in

Example 6 In Example 4, the dithiobenzyl compound S-13 was dispersed when the coating solution for the charge generation layer was dispersed.
Was prepared and evaluated in the same manner as in Example 4, except that 0.1 part of was added and dispersed. Table 1 shows the results
Shown in

(Example 7) In Example 1, the dithiobenzyl compound S-17 was dispersed at the time of dispersing the coating solution for the charge generation layer.
Was prepared and evaluated in the same manner as in Example 1, except that 0.1 part of was added and dispersed. Table 1 shows the results
Shown in

Example 8 In Example 4, the dithiobenzyl compound S-17 was dispersed at the time of dispersing the coating solution for the charge generation layer.
Was prepared and evaluated in the same manner as in Example 4, except that 0.1 part of was added and dispersed. Table 1 shows the results
Shown in

(Example 9) As the charge generation material, 10 parts of the oxytitanium phthalocyanine of Example 1 and 1 part of an azo pigment having the following structural formula were used.

[0085]

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166 parts of a 5% by mass solution of polyvinyl butyral (trade name: Eslek BX-1, manufactured by Sekisui Chemical Co., Ltd.) in a 97: 3 mixed solvent of tetrahydrofuran: water, tetrahydrofuran: water = 97: 3
Was mixed with 150 parts of a mixed solvent of 400 parts each using 400 parts of 1 mmφ glass beads by a sand mill for 4 hours. The ratio of water to the oxytitanium phthalocyanine crystal during the dispersion treatment was 0.92 parts per part of the crystal. Then, a mixed solvent of tetrahydrofuran: water = 97: 3 was diluted by adding 210 parts and 260 parts of cyclohexanone, and an antioxidant having the following structural formula (trade name:
(Antege Crystal, manufactured by Kawaguchi Chemical Co., Ltd.)

[0087]

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Except for preparing the coating solution for the charge generation layer,
An electrophotographic photosensitive member was prepared in the same manner as in Example 1 and evaluated. Table 1 shows the results.

Examples 10 to 18 Polycarbonate
(Product name: Iupilon Z-400, manufactured by Mitsubishi Gas Chemical Company) 5
Was dissolved in 70 parts of monochlorobenzene, and 10 parts of tetrafluoroethylene resin powder (trade name: Lubron L-2, manufactured by Daikin Industries, Ltd.) and a comb-type fluorine graft polymer (trade name: Aron GF300) were dissolved in 70 parts of monochlorobenzene. , Manufactured by Toa Gosei Chemical Co., Ltd.) and dispersed by a sand mill using 1 mmφ glass beads. In 20 parts of the obtained dispersion, 9 parts of a compound represented by the following structural formula,

[0090]

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One part of a compound represented by the following structural formula

[0092]

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And 10 parts of polycarbonate (trade name: Iupilon Z-400, manufactured by Mitsubishi Gas Chemical Co., Ltd.) were dissolved in a mixed solvent of 40 parts of dichloromethane / 40 parts of monochlorobenzene to prepare a coating solution for a charge transport layer. An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Examples 1 to 10. Table 1 shows the results.

Comparative Example 1 The Bragg angle in characteristic X-ray diffraction of CuKα as the charge generating material in Example 1
(2θ ± 0.2 °) has a clear diffraction peak at 27.3 ° (X
The line diffraction diagram shown in FIG. 5) is obtained by dissolving polyvinyl butyral (trade name: Eslek BX-1, manufactured by Sekisui Chemical Co., Ltd.) in a mixed solvent of tetrahydrofuran: water = 95: 5 using 10 parts of oxytitanium phthalocyanine. 166 parts of a 5% by mass solution was prepared, and tetrahydrofuran: water = 9.
Dispersion treatment was performed for 4 hours by a sand mill using 150 parts of a 5: 5 mixed solvent and 400 parts of 1 mmφ glass beads in each case. The ratio of water to the oxytitanium phthalocyanine crystal during the dispersion treatment was 1.
54 parts. Then, tetrahydrofuran: water = 9
210 parts of a 5: 5 mixed solvent and 26 parts of cyclohexanone
0 parts were added and diluted to prepare a coating solution for the charge generation layer.
(X-ray diffraction pattern is FIG. 6). Except for this, an electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1. Table 1 shows the results
Shown in

Comparative Example 2 A coating solution for a charge generation layer was prepared in the same manner as in Example 1 except that the mixed solvent of tetrahydrofuran: water = 97: 3 was changed to 100% tetrahydrofuran. (X-ray diffraction pattern is FIG. 7). An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1. Table 1 shows the results.

[0096]

[Table 1]

[0097]

According to the electrophotographic photoreceptor of the present invention, the method of manufacturing the same, and the process cartridge and the electrophotographic apparatus having the electrophotographic photoreceptor, the image stability is small before and after repetitive durability in which the photo memory is small and ghost is less likely to occur. It has become possible to provide an electrophotographic photoreceptor excellent in quality, a method of manufacturing the same, a process cartridge having the electrophotographic photoreceptor, and an electrophotographic apparatus.

[Brief description of the drawings]

FIG. 1 is a diagram showing a layer configuration of an electrophotographic photosensitive member of the present invention.

FIG. 2 is a diagram illustrating an example of a schematic configuration of an electrophotographic apparatus including a process cartridge having an electrophotographic photosensitive member according to the present invention.

FIG. 3 is a characteristic X-ray diffraction diagram before the dispersion treatment of the oxytitanium phthalocyanine of the present invention.

FIG. 4 is a characteristic X-ray diffraction diagram after dispersion treatment of the oxytitanium phthalocyanine of the present invention.

FIG. 5 is a characteristic X-ray diffraction diagram of oxytitanium phthalocyanine used in Comparative Example before dispersion treatment.

FIG. 6 is a characteristic X-ray diffraction diagram after dispersion treatment of oxytitanium phthalocyanine used in a comparative example.

FIG. 7 is a characteristic X-ray diffraction diagram of oxytitanium phthalocyanine dispersed with a dispersion solvent having no water content.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photosensitive layer 2 charge generation layer 3 charge transport layer 4 conductive support 11 electrophotographic photoreceptor 12 axis 13 charging means 14 exposure light 15 developing means 16 transfer means 17 transfer material 18 fixing means 19 cleaning means 21 process cartridge 22 guide means

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H068 AA14 AA19 AA21 AA34 AA35 BA39 BA57 EA05 EA13 EA14 FA27

Claims (5)

[Claims] 1. An electrophotographic photosensitive member having at least a charge generation layer and a charge transport layer on a conductive support, wherein the charge generation layer has a Bragg angle in characteristic X-ray diffraction of CuKα.
(2θ ± 0.2 °) 9.0 °, 14.2 °, 23.9 °
And an oxytitanium phthalocyanine crystal having a strong peak at 27.1 ° were added to 0.1 part by mass of the crystal.
An electrophotographic photoreceptor formed by using a dispersion liquid that has been subjected to a dispersion treatment with a solvent containing water in an amount of at least 1 part by mass and less than 1 part by mass. 2. The electrophotographic photoconductor according to claim 1, wherein the charge generation layer contains a dithiobenzyl compound represented by the following formula (1). Embedded image (Wherein, R ₁ , R ₂ , R ₃ and R ₄ are the same or different and represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group or a cyano group. M is Ni, Pt, Pd, Co, C
u, Fe, Zn, Cr, Rh, Sn, Zr, Ti, R
u, Os, Re, Mo, W or V) 3. A charging unit for charging the electrophotographic photosensitive member according to claim 1 or 2, a developing unit for developing the electrophotographic photosensitive member on which an electrostatic latent image is formed with toner. And is integrally supported together with at least one means selected from the group consisting of a cleaning means for recovering toner remaining on the electrophotographic photosensitive member after the transfer step, and is detachably attached to the main body of the electrophotographic apparatus. Process cartridge. 4. The electrophotographic photoreceptor according to claim 1 or 2, charging means for charging the electrophotographic photoreceptor, exposure means for exposing the charged electrophotographic photoreceptor to form an electrostatic latent image, An electrophotographic apparatus comprising: developing means for developing an electrophotographic photosensitive member having an electrostatic latent image formed thereon with toner; and transfer means for transferring a toner image on the electrophotographic photosensitive member onto a transfer material. 5. A method for producing an electrophotographic photoreceptor having at least a charge generation layer and a charge transport layer on a conductive support, wherein the Bragg angle (2) in the characteristic X-ray diffraction of CuKα is
θ ± 0.2 °) of an oxytitanium phthalocyanine crystal having strong peaks at 9.0 °, 14.2 °, 23.9 ° and 27.1 ° in an amount of 0.1 part by mass relative to 1 part by mass of the crystal. A method for producing an electrophotographic photoreceptor, wherein the charge generation layer is formed using a dispersion liquid which has been subjected to a dispersion treatment with a solvent containing not less than 1 part by mass and less than 1 part by mass of water.