JP2000239556A - Preparation of dispersion, dispersion for electrophotographic photosensitive layer, electrophotographic photoreceptor, electrophotography, electrophotographic apparatus and process cartridge for electrophotography apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a dispersant capable of providing a stable electrophotographic photoreceptor without losing high sensitivity and without causing reduction in static electrification and rise in residual potential even by repeated use by using a specific organic pigment. SOLUTION: In this method for preparing a dispersion by using an organic pigment by a process being a crystal conversion process for controlling a crystal form by a wet method in a final process in a pigment preparation, a dispersion means is also used in the crystal conversion process. The pigment to be prepared is simultaneously subjected to crystal conversion and dispersion without passing through a drying process. A resin is also used in a crystal conversion solvent. The organic pigment to be prepared is a phthalocyanine-based pigment and is especially preferably titanylphthalocyanine having 27.2 deg.±0.2 deg. maximum diffraction peak by Bragg angle 2θ of at least CuKαcharacteristic X-ray (1.514A wavelength).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preparing a dispersion exhibiting high functions by a specific method, a dispersion for an electrophotographic photosensitive member using the same, an electrophotographic photosensitive member prepared using the dispersion, More particularly, the present invention relates to an electrophotographic method, an electrophotographic apparatus, and a process cartridge for an electrophotographic apparatus using the electrophotographic photoreceptor, and more particularly, to an electrophotographic photoreceptor excellent in the stability of the charged potential and the residual potential of the photoreceptor even after repeated use. The present invention relates to an electrophotographic method, an electrophotographic apparatus, and a process cartridge for an electrophotographic apparatus using the same, which generate less abnormal images.

[0002]

BACKGROUND OF THE INVENTION Organic pigments have been used as fillers in paints for a relatively long time. In particular, the richness of the color is an advantage not found in inorganic pigments. In recent years, various materials and uses have been created as an application example of an organic pigment since it has been spotlighted as a material for an organic photoelectric conversion device.

[0003] In forming such a film containing an organic pigment, a wet film forming method, which can be easily enlarged, is predominant. It is no exaggeration to say that the quality of the coating film formed by the wet film formation method is almost completely affected by the quality of the dispersion liquid containing the pigment. The quality of the dispersion is determined by the dispersibility of the pigment. Thus, a good dispersion is one in which the pigment is sufficiently dispersed in the vehicle and the state of dispersion is maintained for a long time.

In order to produce such a dispersion, various dispersers and dispersion systems have been proposed so far, and methods for increasing the dispersion efficiency have been devised. In order to reduce the particle size of the pigment in the dispersion, a dispersion medium having a small size is generally used. However, if the pigment is difficult to disperse, the dispersing power is insufficient. The only way to improve this is to increase the media size or use a pigment that is easily dispersed. Since the former has a limit on the particle size to be finally reached, it is efficient to develop the latter method. However, there is almost no approach from the pigment side regarding dispersion.

On the other hand, the development of information processing system machines using the electrophotographic system has been remarkable. In particular, optical printers that convert information into digital signals and record information with light have significantly improved print quality and reliability. This digital recording technology is applied not only to printers but also to ordinary copying machines, and so-called digital copying machines have been developed. In addition, since a copier equipped with the digital recording technology in a conventional analog copy is added with various information processing functions, its demand is expected to increase more and more in the future.

At present, small, inexpensive and highly reliable semiconductor lasers (LDs) and light emitting diodes (LEDs) are widely used as light sources for optical printers. The emission wavelength of currently used LEDs is 660 nm, and L
The emission wavelength range of D is in the near infrared region. Therefore, development of an electrophotographic photosensitive member having high sensitivity from a visible light region to a near infrared light region is desired.

The photosensitive wavelength range of an electrophotographic photosensitive member is substantially determined by the photosensitive wavelength region of a charge generating substance used in the photosensitive member. Therefore, many charge generation substances such as various azo pigments, polycyclic quinone pigments, trigonal selenium, various phthalocyanine pigments, etc. have been developed. Among them, titanyl phthalocyanine (abbreviated as TiOPc) is 60
In order to show high sensitivity to long wavelength light from 0 to 800 nm,
It is extremely important and useful as a material for a photoreceptor for an electrophotographic printer or a digital copying machine in which a light source is an LED or LD.

The conditions of the electrophotographic photosensitive member repeatedly used in the Carlson process and similar processes include sensitivity, receiving potential, potential holding property, potential stability,
It is required that the electrostatic characteristics represented by the residual potential and the spectral characteristics be excellent. In particular, for high-sensitivity photoconductors, it has been empirically known that many photoconductors have a decrease in chargeability and an increase in residual potential due to repeated use, which govern the life characteristics of the photoconductor. This is no exception. Therefore, the stability of a photoreceptor using titanyl phthalocyanine by repeated use is not yet sufficient, and there has been an eager desire to complete the technology. Also, there has been a demand for the production of a dispersion liquid (photosensitive layer forming liquid) capable of stably producing a photoreceptor having these characteristics over a long period of time.

The organic photoreceptor is a so-called single-layer photoreceptor in which a photosensitive layer coating solution containing a charge generating substance, a charge transport substance, a binder resin and the like is formed on a conductive support by dip coating or the like. There is a laminated photoreceptor in which a charge generation layer is formed on a conductive support using a coating liquid containing a charge generation substance, and then a charge transport layer is formed using a coating liquid containing a charge transport substance. The laminated photoreceptor may be coated with an undercoat layer or a protective layer for the purpose of improving image quality or durability.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide a stable electrophotographic photoreceptor which does not lose its chargeability and does not increase its residual potential even when repeatedly used without losing high sensitivity. Another object of the present invention is to provide a dispersion capable of stably producing a photosensitive member having the above-mentioned characteristics for a long period of time.
Another object of the present invention is to provide a method for producing a dispersion having the above characteristics. Another object of the present invention is to provide an electrophotographic photoreceptor having improved abrasion resistance while maintaining the above characteristics. Another object of the present invention is to provide a stable electrophotographic method which does not cause a decrease in chargeability and a rise in residual potential even when repeatedly used without losing high sensitivity. Still another object of the present invention is to provide a stable electrophotographic apparatus and a process cartridge for the electrophotographic apparatus which do not cause a decrease in chargeability and an increase in residual potential even when repeatedly used without losing high sensitivity.

[0011]

The present invention has been devised for an organic pigment as follows. The dispersibility of organic pigments can be broadly classified into pigment grindability and dispersion stability. The latter is determined by factors such as wettability between pigment and vehicle, particle size, specific gravity difference between pigment and vehicle, and the like. On the other hand, the former is determined by the hardness of the pigment under certain dispersion conditions. In other words, the hardness of the pigment can be said to be the bulk density of the pigment. The bulk density of a pigment largely depends on the density of the pigment itself and the cohesion of the pigment. The minimum unit of the organic pigment particles is a primary particle, and an interaction between the particles occurs due to an intermolecular hydrogen bond or the like to form a secondary particle in which the primary particles are aggregated. The size of the primary particles is substantially determined during the synthesis of the pigment, unless a means for dissolving the pigment such as acid pasting is used. Since one secondary particle is an aggregate of primary particles,
The state can be changed by the later process of the pigment synthesis. The bulk density of the pigment is determined by the packing strength of the secondary particles.

Further, as described above, organic pigments have recently been applied as photoelectric conversion materials, and materials exhibiting good characteristics generally have strong cohesive strength and very strong secondary particle packing properties. For this reason, it is very difficult to produce a good dispersion. In addition, even in the case of materials represented by the same chemical structural formula, there are many cases where only a specific crystal type expresses a specific function. Such a specific crystal type may be easily changed by a simple physical or mechanical stress other than the chemical stress. In such a case, it is not preferable to apply much physical / mechanical stress such as dispersion, and easy dispersion is a powerful means that can definitely exhibit a specific function.

Further, the present inventors have considered the electrophotographic photosensitive member as follows. That is, as described above, the organic pigment plays an important role as a photocarrier generating material of the electrophotographic photosensitive member. Organic pigments are generally present in the form of fine particles in an electrophotographic photosensitive member. This is because the image writing light in the electrophotographic process is uniformly absorbed at a constant rate. For this reason, if the particles are too large or the particle size distribution is sparse, the resulting electrophotographic photoreceptor not only does not form a clear coating on the photosensitive layer (charge generation layer) containing the organic pigment, but also exhibits abnormalities in the electrophotographic process. An image may be generated. In view of the above, it is preferable that the organic pigment as the charge generating substance has a narrow particle size distribution and a small particle size as much as possible in the dispersion for forming the photosensitive layer (charge generating layer). That is, it is no exaggeration to say that the preparation of a dispersion having high dispersion stability is the key to the success or failure of the electrophotographic photosensitive member.

The present invention is a method for producing a pigment dispersion exhibiting good dispersion stability, and a method for producing a dispersion while maintaining the crystallinity of the pigment used. Its features are:
This is a method for producing a dispersion liquid without passing through the state of the pigment powder (heat-dried state) and maintaining the primary particles and crystal form as much as possible. Further, in the present invention, when a photoreceptor using a dispersion prepared by the above-described technique is used in an electrophotographic process, a reduction in chargeability and a reduction in photosensitivity (increase in residual potential) in repeated use, which have been a problem in the past, have been a problem. It was found that a stable surface potential was given without causing the occurrence of the surface potential. As a result, it has been found that the occurrence of abnormal images such as background contamination or image density reduction is suppressed, and the present invention has been completed.

Therefore, according to the present invention, first, a dispersion is prepared using an organic pigment prepared in a step in which the final step in the preparation of the pigment is a crystal conversion step of controlling the crystal form by a wet method. In the method, there is provided a method for producing a dispersion containing an organic pigment, wherein the crystal conversion step uses a dispersing means in combination.

Secondly, in the above-mentioned preparation method, the pigment to be prepared is subjected to crystal transformation and dispersion of the pigment at the same time without going through a drying step. A method of making a liquid is provided.

Third, the present invention provides a method for preparing a dispersion containing the first organic pigment, wherein a resin is used in combination with a crystal conversion solvent in the above-mentioned method.

Fourthly, there is provided a method for producing a dispersion containing an organic pigment according to any one of the above-mentioned items 1 to 3, wherein the organic pigment produced in the production method is a phthalocyanine pigment. You.

Fifth, the organic pigment produced by the above-described production method is characterized in that at least CuKα characteristic X-rays (wavelength 1.5
14 °), the maximum diffraction peak at Bragg angle 2θ is 2
(7) A method for producing a dispersion containing the organic pigment according to any of (1) to (3) above, wherein the dispersion is titanyl phthalocyanine at an angle of 0.2 ° ± 0.2 °.

Sixth, in a dispersion for an electrophotographic photosensitive member in which an organic pigment is dispersed in at least a solvent, the crystal contained in the dispersion is controlled by a wet method as a final step of pigment preparation. And a dispersion liquid for an electrophotographic photosensitive member, wherein the pigment is obtained by simultaneously performing crystal conversion and dispersion without a drying step.

Seventh, the organic pigment contained in the dispersion is at least CuKα characteristic X-ray (wavelength 1.514).
The maximum diffraction peak at Bragg angle 2θ with respect to Å) is 27.
The sixth dispersion for an electrophotographic photosensitive layer, wherein the dispersion is titanyl phthalocyanine at 2 ° ± 0.2 °.

Eighth, in an electrophotographic photoreceptor having at least a photosensitive layer provided on a conductive support, a dispersion containing an organic pigment for forming the photosensitive layer may have a crystal form as a final step of pigment production. An electrophotographic photoreceptor, which is an organic pigment controlled by a wet method, wherein the pigment is a dispersion obtained by simultaneously performing crystal conversion and dispersion without a drying step. You.

Ninth, there is provided the eighth electrophotographic photosensitive apparatus, wherein the photosensitive layer has a laminated structure of a charge generation layer and a charge transport layer.

Tenthly, there is provided the ninth electrophotographic photosensitive member, wherein the charge transport layer contains a polycarbonate containing at least a triarylamine structure in a main chain and / or a side chain.

Eleventh, in an electrophotographic method in which the electrophotographic photosensitive member is repeatedly subjected to at least charging, image exposure, development, transfer, cleaning, and charge elimination, the electrophotographic photosensitive member is used as a crystal at least as a final step of pigment preparation. A photosensitive layer prepared by using a dispersion containing an organic pigment in which the mold is controlled by a wet method, and the crystal conversion and dispersion are simultaneously performed without a drying step, provided on a conductive support. An electrophotographic method is provided.

Twelfth, an electrophotographic apparatus comprising at least a charging unit, an image exposing unit, a developing unit, a transferring unit, a cleaning unit, a discharging unit, and an electrophotographic photosensitive member, wherein the electrophotographic photosensitive member is At least, as a final step of pigment production, the crystal layer is controlled by a wet method, and a photosensitive layer produced using a dispersion liquid containing an organic pigment in which crystal conversion and dispersion are simultaneously performed without passing through a drying step. And an electrophotographic apparatus provided on a conductive support.

Thirteenth, a process cartridge for an electrophotographic apparatus comprising at least an electrophotographic photosensitive member, wherein the electrophotographic photosensitive member controls a crystal type by a wet method at least as a final step of pigment preparation. It is characterized in that the photosensitive layer is prepared by using a dispersion containing an organic pigment, which has been subjected to crystal conversion and dispersion simultaneously without undergoing a drying step, and is provided on a conductive support. A process cartridge for an electrophotographic apparatus is provided.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
In the present invention, a method for obtaining a target crystal form (for example, titanyl phthalocyanine having a maximum diffraction peak at a black angle of 2θ of 27.2 ° ± 0.2 °) can be performed by a method known in the synthesis process, washing, A method in which crystals are changed in the purification process, and a method in which a crystal conversion step is specially provided. Further, some of the methods for providing a crystal conversion step include a solvent, a general conversion method using mechanical load, and dissolving titanyl phthalocyanine in sulfuric acid, and pouring this solution into water. A sulfuric acid pasting method for performing the conversion is exemplified. Such an amorphous crystal can be converted to a specific crystal form by treatment with an organic solvent as described above, and in general, the amorphous crystal is characterized by having a very small particle size. is there. Generally, after a crystal conversion step, a drying step is performed to obtain a pigment of a predetermined crystal type, and this is dispersed in an appropriate solvent (a resin may be used in combination) using an appropriate disperser to obtain a dispersion liquid. Is prepared.

As described above, the highly functional pigments used in recent years are agglomerated by this drying step, and often become large lumps after drying. In order to prepare a dispersion liquid having a small particle diameter using such a pigment, the dispersion is performed using a medium having a small size. It is necessary to roughly pulverize to the size or to considerably lengthen the dispersion time. At this time, there is a high possibility that physical (mechanical) stress necessary for pulverizing (or dispersing) will change the crystal form of the pigment. For this reason, although the desired crystal form was obtained by processing to change the crystal, the dispersion (photoreceptor)
In some cases, the crystal form is partially changed. Further, in a state where the dispersion is suppressed so as not to change the crystal form, when the pigment particle size in the dispersion is large, a coating film defect is likely to occur, which may cause an abnormal image.

The present inventor has found several points as a result of an examination in view of such disadvantages. (1) Amorphous crystals that have just been subjected to sulfuric acid pasting have extremely small particles. (2) When the pigment subjected to the sulfuric acid paste treatment is dried, the particles become large. (3) If the pigment subjected to the sulfuric acid paste treatment is crystallized in a wet state, the particles can remain small. (4) When the crystal-converted pigment is dried, the particles become large. (5) The crystal conversion is sufficiently performed even when the binder resin is present together with the processing solvent. (6) The impurities generated by the sulfuric acid pasting process are considerably removed during the crystal conversion. This impurity is removed by solvent washing (rinsing is possible).

From the above point of view, the most important point of the present inventor is that the amorphous crystalline pigment which has been subjected to the sulfuric acid pasting treatment is subjected to subsequent crystal transformation (simultaneously using a dispersing means) without drying. This led to the completion of the present invention.

When a dispersion is prepared according to the present invention, the method differs slightly depending on the purity of the pigment subjected to sulfuric acid pasting. When the purity is sufficiently high, the pigment subjected to sulfuric acid paste treatment (wet cake state) is used in combination with a crystal conversion solvent (if necessary, a resin. In this case, the resin is previously dissolved in the solvent. ), And while simultaneously using a dispersing means, simultaneously performing crystal transformation and dispersion while maintaining the size of the particles, to prepare a dispersion.
The dispersing means at this time may be any known method (ball mill,
Bead mill, sand mill, attritor, etc.) can be used. If the purity is not so high, after the crystal conversion, a filtration step is once added (but not dried), and the mixture is placed in a crystal conversion solvent (using a resin if necessary) in a wet state, and the dispersion means is also used. Then, the crystal conversion is continuously performed. In this case, it is wise not to use a binder resin at the time of the first crystal conversion.

The dispersion prepared according to the present invention is a dispersion containing at least a pigment (particularly an organic pigment). This dispersion is a dispersion used for forming a coating film by a wet method. More specifically, it is a dispersion used for forming a charge generation layer of an electrophotographic photoreceptor. The method for preparing the dispersion is as described above, but the pigment used is effective for those having many crystal forms (polymorphism). Typical examples thereof include phthalocyanines. Among them, titanyl phthalocyanine (particularly titanyl phthalocyanine having a maximum diffraction peak at a Bragg angle 2θ of 27.2 ° ± 0.2 ° with respect to characteristic X-ray of CuKα (wavelength 1,514 °)). ) Is particularly effective. A pigment having a predetermined crystal type, a selected solvent, and, if necessary, a binder resin are used in the dispersion.

As the pigment, other charge generating materials can be used in addition to the phthalocyanines. Representative examples thereof include monoazo pigments, disazo pigments, trisazo pigments, perylene pigments, perinone pigments, quinacridone pigments, and the like. Examples thereof include quinone-based condensed polycyclic compounds, squaric acid-based dyes, other phthalocyanine-based pigments, naphthalocyanine-based pigments, and azurenium salt-based dyes.

Next, the electrophotographic photosensitive member produced according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view illustrating an electrophotographic photoreceptor used in the present invention. A single-layer photosensitive layer 33 having a charge generation material and a charge transport material as main components is provided on a conductive support 31. . 2 and 3
FIG. 4 is a cross-sectional view illustrating another configuration example of the electrophotographic photoreceptor used in the present invention, in which a charge generation layer 35 mainly composed of a charge generation material and a charge transport layer 37 mainly composed of a charge transport material are shown.
Are laminated.

The conductive support 31 has a volume resistance of 10
Those exhibiting a conductivity of ¹⁰ Ωcm or less, for example, aluminum, nickel, chromium, nichrome, copper, gold, silver, metals such as platinum, tin oxide, metal oxides such as indium oxide, by evaporation or sputtering, Film or cylindrical plastic, coated with paper, or plates made of aluminum, aluminum alloy, nickel, stainless steel, etc. and extruded, made into a tube by a method such as drawing, cutting, super finishing, polishing, etc. Surface-treated tubes and the like can be used. Further, an endless nickel belt and an endless stainless belt disclosed in JP-A-52-36016 can also be used as the conductive support 31.

In addition to the above, a support obtained by dispersing a conductive powder in a suitable binder resin on the above support and applying the same can also be used as the conductive support 31 of the present invention. As the conductive powder, carbon black, acetylene black, aluminum, nickel, iron, nichrome, copper, zinc,
Metal powder such as silver, or metal oxide powder such as conductive tin oxide and ITO can be used. Further, the binder resin used simultaneously, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer,
Styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral , Thermoplastic resins such as polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, alkyd resin, thermosetting resin or photo-curing resin. can give. Such a conductive layer, these conductive powder and binder resin suitable solvent, for example, tetrahydrofuran, dichloromethane,
It can be provided by dispersing and applying in methyl ethyl ketone, toluene or the like.

Further, the heat-shrinkable tube containing the above-mentioned conductive powder in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, Teflon, etc. on a suitable cylindrical substrate is made conductive. Those provided with a layer can also be favorably used as the conductive support 31 of the present invention.

Next, the photosensitive layer will be described. The photosensitive layer may be a single layer or a stacked layer, but for convenience of explanation, the case where the photosensitive layer is composed of the charge generation layer 35 and the charge transport layer 37 will be described first.

The charge generation layer 35 is a layer containing an organic pigment as a main component. This is a layer obtained by forming a film of the dispersion prepared by the method described above. Charge generation layer 35 if necessary
As the binder resin used for, polyamide, polyurethane, epoxy resin, polyketone, polycarbonate,
Silicone resin, acrylic resin, polyvinyl butyral,
Polyvinyl formal, polyvinyl ketone, polystyrene, polysulfone, poly-N-vinyl carbazole, polyacrylamide, polyvinyl benzal, polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyamide, polyvinyl pyridine, Cellulose-based resins, casein, polyvinyl alcohol, polyvinyl pyrrolidone and the like can be mentioned. The amount of the binder resin is suitably from 0 to 500 parts by weight, preferably from 10 to 300 parts by weight, per 100 parts by weight of the charge generating substance.

Examples of the solvent used here include isopropanol, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane, monochlorobenzene, cyclohexane, toluene, xylene, ligroin and the like. No. The coating method of the coating solution includes dip coating, spray coating, beat coating, nozzle coating, spinner coating,
A method such as a ring coat can be used. The thickness of the charge generation layer 35 is suitably about 0.01 to 5 μm,
Preferably it is 0.1 to 2 μm.

The charge transporting layer 37 can be formed by dissolving or dispersing a charge transporting substance and a binder resin in a suitable solvent, applying this on the charge generating layer, and drying. Also,
If necessary, a plasticizer, a leveling agent, an antioxidant and the like can be added.

The charge transport material includes a hole transport material and an electron transport material. Examples of the charge transport substance include chloranil, bromanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4 , 5,7-Tetranitroxanthone, 2,4,
8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-trinitrodibenzothiophene-5,5
-Electron accepting substances such as dioxides and benzoquinone derivatives.

Examples of the hole transport material include poly-N-vinylcarbazole and its derivatives, poly-γ-galvazolylethylglutamate and its derivatives, pyrene-formaldehyde condensate and its derivatives, polyvinylpyrene, polyvinylphenanthrene, polysilane, Oxazole derivatives, oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives,
α-phenylstilbene derivative, benzidine derivative, diarylmethane derivative, triarylmethane derivative, 9
-Known materials such as styryl anthracene derivative, pyrazoline derivative, divinylbenzene derivative, hydrazine derivative, indene derivative, butadiene derivative, pyrene derivative, bisstilbene derivative, enamine derivative and the like. These charge transport materials are used alone or in combination of two or more.

Examples of the binder resin include polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, and polyacetic acid. Vinyl, polyvinylidene chloride, polyalate, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin And a thermoplastic or thermosetting resin such as phenolic resin and alkyd resin.

The amount of the charge transporting substance is 20 to 300 parts by weight, preferably 40 to 150 parts by weight, per 100 parts by weight of the binder resin.
Parts by weight are appropriate. The charge transport layer has a thickness of 5-1.
It is preferable that the thickness be about 00 μm. As the solvent used here, tetrahydrofuran, dioxane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, methyl ethyl ketone, acetone and the like are used.

In the charge transport layer, a polymer charge transport material having both a function as a charge transport material and a function as a binder resin is preferably used. The charge transport layer composed of these polymeric charge transport materials has excellent abrasion resistance. As the polymer charge transport material, known materials can be used,
Polycarbonates containing a triarylamine structure in the main chain and / or side chain are preferably used. Among them,
Polymer charge transport materials represented by the formulas (1) to (10) are favorably used. These are exemplified below and specific examples are shown below.

[0048]

Embedded imageWhere R₁, R_Two, R_ThreeAre each independently substituted or
Unsubstituted alkyl group or halogen atom, R_FourIs a hydrogen atom
Or a substituted or unsubstituted alkyl group, R_Five, R ₆Is replaced
Or an unsubstituted aryl group, o, p, and q are each independently
And an integer of 0 to 4, k and j represent compositions, and 0.1 ≦ k
≦ 1, 0 ≦ j ≦ 0.9, and n represents the number of repeating units.
It is an integer of 5000. X is an aliphatic divalent group, cyclic fat
Group represented by the following general formula or a divalent group represented by the following general formula:
You.

Embedded image In the formula, R ₁₀₁ and R ₁₀₂ each independently represent a substituted or unsubstituted alkyl group, aryl group or halogen atom.
l and m are integers of 0 to 4; Y is a single bond;
2 linear, branched or cyclic alkylene group, -O
-, - S -, - SO -, - SO 2 -, - CO -, - CO
—O—Z—O—CO— (wherein, Z represents an aliphatic divalent group) or

Embedded image In the formula, a is an integer of 1 to 20, b is an integer of 1 to 2000,
R ₁₀₃ and R ₁₀₄ represent a substituted or unsubstituted alkyl group or aryl group. Here, R ₁₀₁ and R ₁₀₂ , R ₁₀₃ and R
₁₀₄ may be the same or different.

[0049]

Embedded image In the formula, R ₇ and R ₈ represent a substituted or unsubstituted aryl group;
r ₁ , Ar ₂ and Ar ₃ represent the same or different arylene groups. X, k, j and n are the same as in the case of equation (1).

[0050]

Embedded image In the formula, R ₉ and R ₁₀ are a substituted or unsubstituted aryl group,
Ar ₄ , Ar ₅ and Ar ₆ represent the same or different arylene groups. X, k, j and n are the same as in the case of equation (1).

[0051]

Embedded image In the formula, R ₁₁ and R ₁₂ are a substituted or unsubstituted aryl group,
Ar ₇ , Ar ₈ and Ar ₉ are the same or different arylene groups, p
Represents an integer of 1 to 5. X, k, j and n are (1)
Same as for expressions.

[0052]

Embedded imageWhere R₁₃, R₁₄Is a substituted or unsubstituted aryl group,
Ar_Ten, Ar₁₁, Ar ₁₂Are the same or different arylene groups,
X₁, X_TwoIs a substituted or unsubstituted ethylene group, or
Alternatively, it represents an unsubstituted vinylene group. X, k, j and
n is the same as in the case of equation (1).

[0053]

Embedded image In the formula, R ₁₅ , R ₁₆ , R ₁₇ and R ₁₈ are a substituted or unsubstituted aryl group, Ar ₁₃ , Ar ₁₄ , Ar ₁₅ and Ar ₁₆ are the same or different arylene groups, and Y ₁ , Y ₂ and Y ₃ are A single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene ether group, an oxygen atom, a sulfur atom, and a vinylene group may be the same or different. X, k, j and n
Is the same as in the case of equation (1).

[0054]

Embedded image In the formula, R ₁₉ and R _{20 each} represent a hydrogen atom or a substituted or unsubstituted aryl group, and R ₁₉ and R ₂₀ may form a ring. Ar ₁₇ , Ar ₁₈ and Ar ₁₉ represent the same or different arylene groups. X, k, j and n are the same as in the case of equation (1).

[0055]

Embedded image In the formula, R ₂₁ is a substituted or unsubstituted aryl group, A
r ₂₀ , Ar ₂₁ , Ar ₂₂ and Ar ₂₃ represent the same or different arylene groups. X, k, j and n are the same as in the case of equation (1).

[0056]

Embedded image In the formula, R ₂₂ , R ₂₃ , R ₂₄ , and R ₂₅ are a substituted or unsubstituted aryl group, Ar ₂₄ , Ar ₂₅ , Ar ₂₆ , Ar ₂₇ , Ar ₂₈
Represents the same or different arylene groups. X, k, j and n are the same as in the case of equation (1).

[0057]

Embedded imageWhere R₂₆, R₂₇Is a substituted or unsubstituted aryl group,
Ar₂₉, Ar₃₀, Ar ₃₁Represents the same or different arylene groups
Represent. X, k, j and n are the same as in the case of equation (1).
is there.

In the present invention, a plasticizer or a leveling agent may be added to the charge transport layer 37. As the plasticizer, those used as plasticizers for general resins such as dibutyl phthalate and dioctyl phthalate can be used as they are, and the amount of the plasticizer is suitably about 0 to 30% by weight based on the binder resin. As the leveling agent, silicone oils such as dimethyl silicone oil and methyl phenyl silicone oil, and polymers or oligomers having a perfluoroalkyl group in a side chain are used in an amount of 0 to 1 weight based on the binder resin. % Is appropriate.

Next, the case where the photosensitive layer has a single-layer structure 33 will be described. The single-layer photosensitive layer can be formed by dissolving or dispersing the charge transporting substance and the binder resin in a suitable solvent in a suitable solvent, and applying and drying this. further,
The photosensitive layer may be of a function-separated type to which the above-described charge transport material is added, and can be used favorably. If necessary, a plasticizer, a leveling agent, an antioxidant and the like can be added.

As the binder resin, in addition to using the binder resin described above for the charge transport layer 37 as it is, the charge generation layer 3
The binder resins described in 5 may be mixed and used. Of course, the above-mentioned polymer charge transport materials can also be used favorably. The amount of the charge generating substance is preferably 5 to 40 parts by weight, and the amount of the charge transporting substance is 0 to 100 parts by weight of the binder resin.
190 parts by weight is preferable, and 50 to 150 parts are more preferable.
Parts by weight. The single-layer photosensitive layer is formed by dip coating or spraying a coating liquid obtained by dispersing a charge generating substance and a binder resin together with a charge transporting substance, if necessary, using a solvent such as tetrahydrofuran, dioxane, dichloroethane, or cyclohexane using a dispersing machine or the like. It can be formed by coating with a coat or bead coat. The thickness of the single-layer photosensitive layer is suitably about 5 to 100 μm.

The electrophotographic photosensitive member of the present invention may have an undercoat layer between the conductive support 31 and the photosensitive layer. The undercoat layer generally contains a resin as a main component. However, considering that the photosensitive layer is coated thereon with a solvent, these resins are resins having high solvent resistance to general organic solvents. desirable. Examples of such a resin include water-soluble resins such as polyvinyl alcohol, casein and sodium polyacrylate, alcohol-soluble resins such as copolymerized nylon and methoxymethylated nylon, polyurethane, melamine resin, phenol resin, alkyd-melamine resin, and epoxy resin. Curable resins that form a three-dimensional network structure, such as resins, are exemplified. Further, a fine powder pigment of a metal oxide exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide and the like may be added to the undercoat layer in order to prevent moiré and reduce residual potential.

These undercoat layers can be formed by using an appropriate solvent and a coating method as in the above-mentioned photosensitive layer. Furthermore, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can be used as the undercoat layer of the present invention. In addition, the undercoat layer of the present invention, A1 ₂
O ₃ provided by anodic oxidation, organic substances such as polyparaxylylene (parylene), SiO ₂ , SnO ₂ , Ti
Those provided with an inorganic substance such as O ₂ , ITO, or CeO ₂ by a vacuum thin film manufacturing method can also be used favorably. In addition, known materials can be used. The thickness of the undercoat layer is 0 to 5 μm
Is appropriate.

In the electrophotographic photosensitive member of the present invention, a protective layer may be provided on the photosensitive layer for the purpose of protecting the photosensitive layer. The material used for the protective layer is ABS resin, AC
S resin, olefin-vinyl monomer copolymer, chlorinated polyether, allyl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallyl sulfone, polybutylene, polybutylene terephthalate, polycarbonate, polyether sulfone, polyethylene, polyethylene terephthalate,
Polyimide, acrylic resin, polymethylpentene, polypropylene, polyphenylene oxide, polysulfone,
Examples include resins such as polystyrene, AS resin, butadiene-styrene copolymer, polyurethane, polyvinyl chloride, polyvinylidene chloride, and epoxy resin. Other protective layers include fluororesins such as polytetrafluoroethylene, silicone resins, and inorganic materials such as titanium oxide, tin oxide, and potassium titanate dispersed in these resins for the purpose of improving abrasion resistance. Can be added. As a method for forming the protective layer, an ordinary coating method is employed. The thickness of the protective layer is suitably about 0.1 to 10 μm. In addition to the above, a-C,
A known material such as a-SiC can be used as the protective layer.

In the present invention, an intermediate layer can be provided between the photosensitive layer and the protective layer. The intermediate layer generally uses a binder resin as a main component. Examples of these resins include polyamide, alcohol-soluble nylon, water-soluble polyvinyl butyral, polyvinyl butyral, and polyvinyl alcohol. As a method for forming the intermediate layer, a normal coating method is employed as described above. In addition,
The thickness of the intermediate layer is suitably about 0.05 to 2 μm.

Next, the electrophotographic method and the electrophotographic apparatus of the present invention will be described in detail with reference to the drawings.

FIG. 4 is a schematic view for explaining the electrophotographic process and the electrophotographic apparatus of the present invention, and the following modified examples also belong to the category of the present invention.

In FIG. 4, the photosensitive member 1 is provided with a photosensitive layer formed on a conductive support using a dispersion prepared by the above-described method. The photoconductor 1 has a drum shape, but may have a sheet shape or an endless belt shape. Charging charger 3, pre-transfer charger 7, transfer charger 10, separation charger 11,
Known means such as a corotron, a scorotron, a solid state charger (solid state charger), and a charging roller are used for the pre-cleaning charger 13.

As the transfer means, the above-mentioned charger can be generally used, but as shown in the figure, a combination of a transfer charger and a separation charger is effective.

Light sources such as the image exposure unit 5 and the neutralizing lamp 2 include a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, and a light emitting diode (LE).
D), semiconductor lasers (LD), electroluminescence (EL), and other general light-emitting materials can be used.
To irradiate only light in a desired wavelength range, various filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used.

The light source and the like are provided with a transfer step, a charge removal step, a cleaning step, and a pre-exposure step using light irradiation in addition to the steps shown in FIG.
Light is applied to the photoconductor.

The toner developed on the photoreceptor 1 by the developing unit 6 is transferred to the transfer paper 9, but not all of the toner is transferred, and some toner remains on the photoreceptor 1. Such toner is removed from the photoconductor by the fur brush 14 and the blade 15. Cleaning may be performed only with a cleaning brush, and a known brush such as a fur brush or a mag fur brush is used as the cleaning brush.

When a positive (negative) charge is applied to the electrophotographic photosensitive member and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. If this is developed with toner of negative (positive) polarity (electrostatic detection fine particles), a positive image can be obtained, and if it is developed with toner of positive (negative) polarity, a negative image can be obtained. A known method is applied to such a developing unit.
In addition, a known method is used for the charge removing means.

FIG. 5 shows another example of the electrophotographic process according to the present invention. The photoreceptor 21 has a photosensitive layer formed by using the dispersion prepared by the above-described method, is driven by the drive rollers 22a and 22b, is charged by the charger 23, is exposed by the light source 24, and is developed ( Not shown),
Transfer using the charger 25, exposure before cleaning by the light source 26, cleaning by the brush 27, and static elimination by the light source 28 are repeatedly performed. In FIG. 5, the photosensitive member 2
1 (of course, in this case, the support is translucent), light irradiation for pre-cleaning exposure is performed from the support side.

The above illustrated electrophotographic process is an example of the embodiment of the present invention, and other embodiments are of course possible. For example, in FIG. 5, the pre-cleaning exposure is performed from the support side, but this may be performed from the photosensitive layer side, or the image exposure and the charge erasing exposure may be performed from the support side.

On the other hand, the light irradiation step includes image exposure, pre-cleaning exposure, and static elimination exposure. However, in addition to the above, a pre-transfer exposure, a pre-exposure of image exposure, and other known light irradiation steps are provided. Light irradiation can also be performed on the body.

The image forming means as described above may be fixedly incorporated in a copying apparatus, a facsimile, or a printer, or may be incorporated in the apparatus in the form of a process cartridge. The process cartridge includes a photoconductor, and further includes a charging unit, an exposing unit, a developing unit, a transferring unit, a cleaning unit, and a discharging unit.
Devices (parts). Although there are many shapes and the like of the process cartridge, a general example is shown in FIG. The photoreceptor 16 has a photosensitive layer formed on a conductive support using a dispersion prepared by the method described above. The photoreceptor 16 has a TiOPc photosensitive layer that gives a specific X-ray diffraction spectrum on a conductive support.

[0077]

The present invention will be described below with reference to examples.
The present invention is not limited by these embodiments. All parts are parts by weight.

Example 1 First, the maximum diffraction peak at a Bragg angle of 2θ was 27.2 ° ±
A specific synthesis example of a crystal form (so-called Y type) titanyl phthalocyanine pigment at 0.2 ° will be described. (Pigment Production Example) 52.5 parts of fuclodinitrile and 400 parts of 1-chloronaphthalene are stirred and mixed, and 19 parts of titanium tetrachloride are added dropwise under a nitrogen stream. After dropping, slowly add 200
C., and the reaction was carried out by stirring for 5 hours while maintaining the reaction temperature between 190.degree. C. and 210.degree. After the completion of the reaction, the mixture was allowed to cool to 130 ° C. and was filtered while hot.
The powder was washed with chloronaphthalene until the powder turned blue, then washed several times with methanol, further washed several times with hot water at 80 ° C., and dried to obtain 42.2 parts of a crude titanyl phthalocyanine pigment. The obtained crude titanyl phthalocyanine pigment washed with hot water was stirred in 100 parts of 96% sulfuric acid at 3 to 5 ° C., dissolved, and filtered. The obtained sulfuric acid solution was dropped into 3500 parts of ice water while stirring, and the precipitated crystals were filtered and then washed repeatedly with water until the washing liquid became neutral to obtain a wet cake of titanyl phthalocyanine pigment. 6 parts of this wet cake and 320 parts of 2-butanone in which 4 parts of butyral resin were dissolved were put into a glass pot containing zirconia balls having a diameter of 2 mm, and dispersed by a ball mill for 2 hours to obtain a dispersion. 1).

The obtained wet cake and the portion of the dispersion after washing were dried, and the X-ray diffraction spectrum of the powder was measured under the following conditions. X-ray tube Cu, voltage 40 kV, current 20 mA, scanning speed 1 ° / min, scanning range 3 ° -40 ° time constant 2 seconds,

FIG. 7 shows the X-ray diffraction spectrum of the dried wet cake. It can be seen that the pigment in the obtained wet cake has an irregular shape. FIG. 8 shows an X-ray diffraction spectrum of the titanyl phthalocyanine pigment in the dispersion obtained in Example 1. The obtained titanyl phthalocyanine pigment has a maximum diffraction peak of 2 at a Bragg angle of 2θ.
It can be seen that the crystal has a crystal form at 7.2 ° ± 0.2 °.

Example 2 6 parts of the wet cake obtained in Example 1 after the sulfuric acid pasting treatment and 320 parts of tetrahydrofuran in which 4 parts of butyral resin were dissolved were dispersed with a bead mill disperser containing zirconia beads having a diameter of 0.2 mm. A dispersion was prepared in exactly the same manner as in Example 1 except that this was performed (this is referred to as dispersion 2).

Example 3 6 parts of the wet cake obtained in Example 1 after the sulfuric acid paste treatment and 320 parts of 2-butanone (without adding butyral resin) were subjected to ball milling under the same conditions as in Example 1 to obtain a dispersion. A dispersion was prepared in the same manner as in Example 1 except that 4 parts of the butyral resin used in Example 1 was later dissolved (this is referred to as dispersion 3).

Comparative Example 1 6 parts of the wet cake obtained in Example 1 after the sulfuric acid paste treatment was subjected to crystal conversion with 320 parts of 2-butanone (no butyral resin was added), filtered, and filtered at 80 ° C. Vacuum drying was performed daily to obtain a pigment powder. Using this pigment, ball mill dispersion was performed with the following composition in the same manner as in Example 1 to prepare a dispersion (this is referred to as dispersion 4). 6 parts of the titanyl phthalocyanine powder described above 6 parts of polyvinyl acetal 4 parts of 2-butanone

Comparative Example 2 A dispersion was prepared in the same manner as in Comparative Example 1 except that the ball mill dispersion time in Comparative Example 1 was changed to 12 hours (this is referred to as Dispersion 5).

Comparative Example 3 The crystal conversion solvent and the dispersion solvent in Comparative Example 1 were
A dispersion was prepared in exactly the same manner as in Comparative Example 1 except that butanone was changed to tetrahydrofuran (this is referred to as dispersion 6).

Comparative Example 4 A dispersion was prepared in the same manner as in Comparative Example 1 except that the ball mill dispersion time in Comparative Example 3 was changed to 12 hours (this is referred to as Dispersion 7).

The average particle size of the dispersions (dispersions 1 to 7) prepared in Examples 1 to 3 and Comparative Examples 1 to 4 was set to CAPA7.
00 (manufactured by Horiba, Ltd.). Table 1 shows the results. In addition, each dispersion was allowed to stand for one month at room temperature in a dark place,
The state of the dispersion was observed. Further, the dispersion was dried to obtain a powder, and the X-ray diffraction spectrum of the powder was measured by the method described above. Table 1 also shows these results.

[0088]

[Table 1] From Table 1, it can be seen that the dispersions 5 and 7 have small particle diameters and good sedimentation properties, but partially change the crystal form. In addition, it can be seen that the dispersions 1, 2, and 3 have a small particle size and are stable after storage. On the other hand, it can be seen that the dispersions 4 and 6 have large particles and large sedimentation properties.

Examples 4 and 5 and Comparative Examples 5 and 6 An undercoat layer coating solution, a charge generation layer coating solution and a charge transport layer coating solution having the following compositions and having the following compositions were successively applied on an electroformed nickel belt. Coating and drying were performed to produce a laminated photoreceptor. [Undercoat layer coating liquid] Titanium dioxide powder 15 parts Polyvinyl butyral 6 parts 2-butanone 150 parts [Charge generating layer coating liquid] The dispersion 1 was used in Example 4, and the dispersion was used in Example 5. 2, the dispersion 3 was used in Comparative Example 5, and the dispersion 7 was used in Comparative Example 6. [Charge transport layer coating solution] Polycarbonate 10 parts Charge transport material of the following structural formula 8 parts

Embedded image 80 parts of methylene chloride

The electrophotographic photoreceptor thus formed is shown in FIG.
And the image exposure light source was set to a 780 mm semiconductor laser (image writing using a polygon mirror) so that the surface potential of the photoconductor immediately before development could be measured. A total probe was inserted. Printing was continuously performed on 5000 sheets, and the surface potentials of the image-exposed area and the image non-exposed area at that time were measured at the initial stage and after 5,000 sheets. Table 2 shows the results.

[0091]

[Table 2] Table 2 shows that the electrophotographic photosensitive members of Examples 4 and 5 maintain a stable surface potential even after repeated use.

Examples 6 and 7 and Comparative Examples 7 and 8 The surface of an aluminum cylinder was anodized and then sealed. On this, the following charge generation layer coating solution and charge transport layer coating solution were sequentially applied and dried to form a charge generation layer having a thickness of 0.2 μm and a charge transport layer having a thickness of 20 μm, respectively. A photoreceptor was prepared. [Coating solution for charge generation layer] The dispersion 1 was used in Example 6, the dispersion 3 was used in Example 7, the dispersion 4 was used in Comparative Example 7, and the dispersion 4 was used in Comparative Example 8. Dispersion 6 was used. [Coating solution for charge transport layer] 7 parts of charge transport material having the following structural formula

Embedded image Polycarbonate 10 parts Methylene chloride 80 parts

Examples 8 and 9 and Comparative Examples 9 and 10 The dispersions used in Examples 6 and 7 and Comparative Examples 7 and 8 were allowed to stand still at room temperature in a dark place for one month. Photoconductors were produced in the same manner as in Comparative Examples 7 and 8.

FIG. 6 shows an electrophotographic photosensitive member having the above configuration.
After installing in the electrophotographic process cartridge shown in
It was mounted on an image forming apparatus. Image exposure light source is 780mm semiconductor laser (image writing by polygon mirror)
And 5000 sheets were continuously printed, and the initial and 5000th sheet images were evaluated. From Table 3, Dispersions 6, 7
Is used (the photoreceptors of Examples 6, 7, 8, and 9)
It can be seen that a good image can be obtained after repeated use and after dispersion storage.

[0095]

[Table 3]

Example 10 A photoconductor was prepared in the same manner as in Example 6, except that the support in Example 6 was changed from an electroformed nickel belt to an aluminum cylinder.

Example 11 A photoconductor was prepared in the same manner as that of Example 10 except that the coating solution for the charge transport layer in Example 10 was changed to the following composition. [Coating solution for charge transport layer] 10 parts of polymer charge transport material having the following structural formula

Embedded image 100 parts of methylene chloride

Example 12 A photoconductor was prepared in the same manner as that of Example 10 except that the coating liquid for the charge transport layer in Example 10 was changed to the following composition. [Coating solution for charge transport layer] 10 parts of polymer charge transport material having the following structural formula

Embedded image 100 parts of methylene chloride

Each of the electrophotographic photosensitive members of Examples 10 to 12 was mounted in the electrophotographic process shown in FIG. 4 (however, an image exposure light source was an LD having a light emission at 780 nm), and 10,000 sheets were continuously printed. Was printed, and the image at that time was evaluated at the initial stage and after 10,000 copies. Further, a change (decrease amount) in the film thickness of the charge transport layer was measured. Table 4 shows the results.

[0100]

[Table 4] From Table 4, it can be seen that the electrophotographic photosensitive members of Examples 10 to 12 show particularly excellent abrasion resistance.

[0101]

According to the present invention, a photoreceptor manufactured using a dispersion prepared by a specific manufacturing method can have a reduced chargeability and an increased residual potential even after repeated use without losing high sensitivity. This is a stable electrophotographic photoreceptor that does not cause any problems. Further, there is provided a dispersion capable of maintaining the above-mentioned stable properties even after long-term storage. Further, an electrophotographic photoreceptor having improved abrasion resistance while maintaining the above characteristics is provided. Further, there is provided a stable electrophotographic method which does not cause a decrease in chargeability and a rise in residual potential even when repeatedly used without losing high sensitivity. Further, there is provided a stable electrophotographic apparatus and a process cartridge for the electrophotographic apparatus which do not cause a decrease in chargeability and an increase in residual potential even when repeatedly used without losing high sensitivity.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an electrophotographic photosensitive member used in the present invention.

FIG. 2 is a schematic sectional view of another electrophotographic photosensitive member used in the present invention.

FIG. 3 is a schematic sectional view of still another electrophotographic photosensitive member used in the present invention.

FIG. 4 is a schematic diagram for explaining an electrophotographic process and an electrophotographic apparatus of the present invention.

FIG. 5 is a schematic diagram for explaining an electrophotographic process and an electrophotographic apparatus of the present invention.

FIG. 6 is a schematic diagram illustrating a typical electrophotographic apparatus of the present invention.

FIG. 7 is an X-ray diffraction spectrum of a dried product of the wet cake obtained in Example 1.

FIG. 8 is an X-ray diffraction spectrum of the titanyl phthalocyanine pigment in the dispersion obtained in Example 1.

FIG. 9 is an X-ray diffraction spectrum of a titanyl phthalocyanine pigment in the dispersion obtained in Comparative Example 4.

Claims (13)

[Claims] 1. A method for producing a dispersion using an organic pigment produced by a step in which the final step in the production of a pigment is a crystal conversion step of controlling the crystal form by a wet method, wherein the crystal conversion step is performed by a dispersing means. A method for producing a dispersion containing an organic pigment, characterized by using 2. The dispersion containing an organic pigment according to claim 1, wherein, in the production method, the pigment to be produced is subjected to crystal transformation and dispersion of the pigment at the same time without going through a drying step. Method of manufacturing. 3. The method for producing a dispersion containing an organic pigment according to claim 1, wherein in the production method, a resin is used in combination with a crystal conversion solvent. 4. The method for producing a dispersion containing an organic pigment according to claim 1, wherein the organic pigment produced in the production method is a phthalocyanine pigment. 5. The method according to claim 1, wherein the organic pigment produced by the production method is at least CuKα characteristic X-ray (wavelength 1.514).
The maximum diffraction peak at Bragg angle 2θ with respect to Å) is 27.
The method for producing a dispersion containing an organic pigment according to claim 1, wherein the dispersion is titanyl phthalocyanine at 2 ° ± 0.2 °. 6. In a dispersion for an electrophotographic photosensitive member in which an organic pigment is dispersed in at least a solvent, the crystal contained in the dispersion is controlled by a wet method as a final step of pigment production. A dispersion liquid for an electrophotographic photoreceptor, which is an organic pigment, wherein the pigment is obtained by simultaneously performing crystal conversion and dispersion without a drying step. 7. The organic pigment contained in the dispersion has a maximum diffraction peak at a Bragg angle 2θ of at least 27.2 ° ±. With respect to CuKα characteristic X-rays (wavelength 1.514 °).
7. The dispersion for an electrophotographic photosensitive layer according to claim 6, which is titanyl phthalocyanine at an angle of 0.2 °. 8. In an electrophotographic photoreceptor having at least a photosensitive layer provided on a conductive support, a dispersion containing an organic pigment for forming the photosensitive layer is subjected to a wet process by a crystal method as a final step of pigment production. An electrophotographic photoreceptor characterized in that the pigment is a dispersion obtained by simultaneously performing crystal conversion and dispersion without a drying step. 9. The electrophotographic photoreceptor according to claim 8, wherein said photosensitive layer has a laminated structure of a charge generation layer and a charge transport layer. 10. The electrophotographic photoreceptor according to claim 9, wherein the charge transport layer contains a polycarbonate containing at least a triarylamine structure in a main chain and / or a side chain. 11. An electrophotographic method in which an electrophotographic photosensitive member is repeatedly subjected to at least charging, image exposure, development, transfer, cleaning, and charge elimination. A photosensitive layer prepared using a dispersion containing an organic pigment, which is controlled by the method and undergoes simultaneous crystal transformation and dispersion without a drying step, is provided on a conductive support. An electrophotographic method comprising: 12. An electrophotographic apparatus comprising at least a charging unit, an image exposing unit, a developing unit, a transferring unit, a cleaning unit, a discharging unit, and an electrophotographic photosensitive member,
The electrophotographic photoreceptor is controlled by a wet method at least in a crystal form as a final step of pigment production, and using a dispersion containing an organic pigment in which crystal conversion and dispersion are simultaneously performed without a drying step. An electrophotographic apparatus, wherein the produced photosensitive layer is provided on a conductive support. 13. A process cartridge for an electrophotographic apparatus comprising at least an electrophotographic photosensitive member, wherein the electrophotographic photosensitive member is controlled in a crystal form by a wet method at least as a final step of pigment preparation, and Electrophotography characterized in that a photosensitive layer produced using a dispersion containing an organic pigment in which crystal transformation and dispersion have been simultaneously performed without a drying step is provided on a conductive support. Process cartridge for equipment.