JP2002006517A - Electrophotographic photoreceptor and process cartridge and electrophotographic device having the electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor which has high durability and high sensitivity, having no accumulation of residual potential in repeated electrophotographic processes, which will not cause changes in the characteristics, depending on the user environment and which can maintain high image quality, and to provide a process cartridge and an electrophotographic device having the electrophotographic photoreceptor. SOLUTION: The electrophotographic photoreceptor, having at least a photosensitive layer and a surface protective layer on a conductive support body has the following features. The photosensitive layer contains phthalocyanine, having gallium atoms in the center of the molecule as a charge-generating material. The photosensitive layer directly under the surface protective layer contains an alcohol-insoluble polymer as binder resin. The coating material used for the formation of the surface protective layer contains at least either of a conductive material or an alcohol-soluble charge transfer material and alcohol. The process cartridge and the electrophotographic device are quipped with the electrophotographic photoreceptor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member, a process cartridge provided with the electrophotographic photosensitive member, and an electrophotographic apparatus.

[0002]

2. Description of the Related Art Conventionally, selenium,
Inorganic photoreceptors having a photosensitive layer containing zinc oxide and cadmium as main components have been widely used. Although these have some basic properties, they have problems such as poor film formability, poor plasticity, and high manufacturing cost. Furthermore, inorganic photoconductive materials are generally highly toxic, and have great restrictions on production and handling. On the other hand, an organic photoreceptor containing an organic photoconductive compound as a main component has attracted attention in recent years because it has many advantages such as compensating for the above-mentioned drawbacks of the inorganic photoreceptor. Have been. As such an organic photoreceptor, a function-separated type electrophotographic photoreceptor in which a charge generation function and a charge transport function are respectively assigned to different substances has been widely used. Such a function-separated type photoreceptor has the advantage that the material selection range of the charge generation material and the charge transport material is wide, and an electrophotographic photoreceptor having any desired characteristics can be relatively easily produced. As a charge generating material, cyanine dyes, squaric acid dyes, azurenium salt dyes, pyrylium salt dyes, azo pigments and polycyclic quinone pigments,
On the other hand, it is known that the use of a pyrazoline compound, a hydrazone compound, a triphenylamine compound, a stilbene compound, or the like as a charge transport material provides excellent electrophotographic properties.

[0003] In addition, the electrophotographic photoreceptor naturally has
It is required to have required sensitivity, electrical characteristics and optical characteristics according to the applied electrophotographic process. In particular, in the case of a photoreceptor that is used repeatedly, since electrical and mechanical external forces such as charging, image exposure, toner development, transfer to paper, and cleaning are directly applied to the surface of the photoreceptor, Durability is required. In particular,
It is required to have durability against abrasion and scratches on the surface caused by rubbing against the surface of the photoreceptor at the time of transfer, cleaning, and the like, and deterioration of the photoreceptor and potential characteristics due to ozone and charge products generated during charging. Further, there is a problem that toner adheres to the surface of the photoreceptor due to repetition of toner development and cleaning, and good cleaning properties are also required.

In particular, regarding the surface characteristics of such an electrophotographic photoreceptor, the fact that an organic compound generally has a lower strength than an inorganic compound, and therefore, in many cases, does not reach the level of an inorganic photoreceptor. is there.

Attempts have been made to provide a surface protective layer containing a high-strength resin as a main component on a photosensitive layer in order to satisfy the characteristics required for the organic photoreceptor as described above. For example,
JP-A-1-178971 and JP-A-1-217363
Japanese Patent Application Laid-Open Publication No. H11-163840 proposes improving the hardness and abrasion resistance by providing a surface protective layer formed on the organic photosensitive layer by three-dimensionally cross-linking with a thermosetting resin.

In order to obtain a better image, not only the surface protection layer of the photoreceptor has characteristics such as high hardness and excellent abrasion resistance, but also charge transfer within the surface protection layer. It is required to cancel the charge in the photosensitive layer and the charge due to charging. Although the three-dimensionally crosslinked resin has high hardness, it is generally an electrically insulating material, so the resistance of forming the protective layer only with the resin is too high, and by repeating the electrophotographic process such as charging and exposure, Charges are accumulated in the surface protective layer, that is, an increase in the so-called residual potential occurs. Since the potential is not stabilized when the photoconductor is repeatedly used, the image quality becomes unstable. In particular, since this phenomenon becomes more remarkable as the thickness of the surface protective layer increases, the thickness of the surface protective layer must be extremely small, and it is difficult to greatly extend the life of the electrophotographic photosensitive member. In order to improve this problem, for example, JP-A-57-30843 proposes to control the resistance of a surface protective layer by adding a metal oxide or the like as conductive fine particles to the surface protective layer. Also, Japanese Patent Application Laid-Open No. 9-93280 proposes that the protective layer is cured after the charge transport material is contained in the surface protective layer without depending on the electric resistance of the surface protective layer. However, in these cases as well, a solvent for dissolving or swelling the photosensitive layer, such as an aromatic compound or a ketone compound, is generally used as the coating solution for the protective layer when forming the surface protective layer. When the surface layer is formed using such a solvent, migration of the compounds contained in the respective layers occurs between the surface protective layer and the photosensitive layer, and the curability of the surface protective layer and the photosensitive layer are reduced. And / or an adverse effect that the transfer of charges in the surface protective layer is inhibited occurs. In order to suppress such adverse effects, there has been proposed a method of forming a surface protective layer by so-called spray coating in which a coating solution for a protective layer is sprayed onto the photosensitive layer to apply the same. Migration is inevitable, and the productivity is significantly lower than that of the conventional dip coating method.

[0007] Even if a thermosetting resin is selected as a binder resin for the surface protective layer, discontinuity of chemical bonding can be reduced by including a conductive material such as metal oxide fine particles in the protective layer. As a result, it is difficult to obtain sufficient mechanical strength. Further, even in a surface protective layer containing a charge transport material without using a conductive material, it is often difficult to obtain sufficient mechanical strength because the charge transport material itself often inhibits a curing reaction of the surface protective layer. Met.

When a thermosetting resin is used as a binder resin of a surface protective layer containing a conductive material or a charge transport material, in order to impart sufficient strength to the surface protective layer, the curing temperature must be increased or heat treatment must be performed. A method of increasing the time is effective. However, the heat resistance of photoreceptor materials is generally low, and the cross-linking reaction of thermosetting resin is particularly difficult for charge generating materials due to various factors such as changes in crystal structure, reduction of water of crystallization, and interaction with charge transport materials. When the heat treatment is carried out to sufficiently advance the above, the electrophotographic characteristics of the photoreceptor are remarkably reduced, causing an increase in residual potential and a decrease in sensitivity.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to maintain high quality image with high durability, high sensitivity, no accumulation of residual potential in repeated electrophotographic processes, and no change in characteristics due to use environment. An object of the present invention is to provide a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member, wherein the electrophotographic photosensitive member can be manufactured with high productivity.

[0010]

According to the present invention, there is provided an electrophotographic photosensitive member having at least a photosensitive layer and a surface protective layer on a conductive support, wherein the photosensitive layer comprises a phthalocyanine having a gallium atom at its center as a charge generating material. Wherein the photosensitive layer immediately below the surface protective layer contains an alcohol-insoluble polymer as a binder resin, and the coating used for forming the surface protective layer comprises at least one of a conductive material and an alcohol-soluble charge transport material and an alcohol. An electrophotographic photoreceptor characterized by containing:

When the surface protective layer is provided with the above structure, the paint for the surface protective layer does not attack the photosensitive layer, so that the migration of various compounds between the surface protective layer and the photosensitive layer increases the residual potential, decreases the sensitivity, Further, it has become possible to suppress adverse effects such as a decrease in the strength of the surface protective layer.

Further, the present invention is the above electrophotographic photosensitive member, wherein the surface protective layer is formed by heating and forming a film of a binder resin containing an alcohol-soluble thermosetting resin as a main component.

According to this structure, not only the problem of the erosion of the photosensitive layer by the coating for the surface protective layer described above can be avoided, but also the heating conditions at the time of forming the protective layer are increased in order to impart sufficient strength to the surface protective layer. This also makes it possible to form an electrophotographic photosensitive member without deteriorating the photosensitive layer.

Further, the present invention is the above electrophotographic photosensitive member, wherein the surface protective layer contains an alcohol-soluble charge transporting material and / or fine metal particles or fine metal oxide particles as a conductive material.

With this configuration, the charge in the photosensitive layer and the charge on the surface of the electrophotographic photosensitive member in the electrophotographic process can be canceled without delay, so that the electrophotographic characteristics are not impaired.

Further, the present invention is the above electrophotographic photosensitive member, wherein the surface protective layer contains a conductive material and at least one of a fluorine atom-containing compound and a siloxane compound.

With this structure, the conductive material is stably dispersed in the coating for the surface protective layer and the surface protective layer film without agglomeration, and has sufficient light transmittance and resistance stability of the surface protective layer. It becomes possible.

Further, the present invention is the above electrophotographic photosensitive member, wherein the surface protective layer contains an alcohol-soluble charge transporting material having one or both of a hydroxyalkyl group and a hydroxyalkoxy group.

With this structure, the charge transporting material can be stably molecularly dispersed in the coating for the surface protective layer and the surface protective layer film without deposition, and can have sufficient light transmittance and charge transportability. Become.

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

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The conductive support used in the present invention may be any as long as it has conductivity.
For example, aluminum, chromium, nickel, stainless steel,
Metals and alloys such as copper and zinc, metal foils such as aluminum and copper laminated on plastic films, aluminum, indium oxide and tin oxide deposited on plastic films, or conductive materials used alone or Examples thereof include metals, plastic films, and papers provided with a conductive layer by being applied together with a binder resin.

The conductive material used for the conductive layer includes metal powders such as aluminum, copper, nickel, and silver;
Metal foil and metal fiber, antimony oxide, conductive metal oxides such as indium oxide and tin oxide, polypyrrole, polymer conductive materials such as polyaniline and polymer electrolyte, carbon black, graphite powder and organic or inorganic electrolyte, and Conductive powders whose surfaces are coated with these conductive materials are exemplified.

The conductive support may have a drum shape,
Examples include a sheet shape and a belt shape, and it is preferable that the shape is an arbitrary shape most suitable for the applied electrophotographic apparatus.

An undercoat layer may be provided between the conductive support and the photosensitive layer. The undercoat layer functions as a barrier layer or an adhesive layer for controlling charge injection at the interface with the photosensitive layer. The undercoat layer is mainly made of a binder resin, but may contain the above-mentioned metal or alloy, or an oxide, salt or surfactant thereof.

As the binder resin for forming the undercoat layer, polyester, polyurethane, polyacrylate, polyethylene, polystyrene, polybutadiene, polycarbonate, polyamide, polypropylene, polyimide, phenol resin, acrylic resin, silicone resin, epoxy resin, urea resin , Allyl resin, alkyd resin, polyamide imide, polysulfone, polyallyl ether, polyacetal, and butyral resin. The thickness of the undercoat layer is preferably 0.05 to 7 μm, more preferably 0.1 to 2 μm.

The photosensitive layer according to the present invention includes a function-separated type photosensitive layer in which a charge generation layer and a charge transport layer are separately laminated, and a single layer containing a charge generation material and a charge transport material in the photosensitive layer. It is possible to take any form of the photosensitive layer.

The charge generation layer in the present invention is formed as a uniform layer formed by depositing a charge generation material by a method such as vapor deposition and sputtering, or by applying and drying a dispersion in which the charge generation material is dispersed in a binder resin. It is formed by this.

The charge generation material used in the photosensitive layer is phthalocyanine whose central metal is gallium,
In particular, a phthalocyanine-based charge generating material having a gallium atom in the center is a hydroxygallium phthalocyanine and a Bragg angle 2 having a strongest peak at 28.1 ° of Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction.
θ ± 0.2 ° of at least 7.4 °, 16.6 °, 2
Chlorogallium phthalocyanine having strong peaks at 5.5 ° and 28.3 ° is preferred.

As the binder resin, in the case of a functional separation type photosensitive layer, a resin for a charge generation layer which is conventionally used can be used. For example, a polyvinyl acetal resin such as polyvinyl butyral and polyvinyl formal, a polystyrene, an acrylic resin , Cellulose ester, cellulose ether, polyester, polycarbonate, phenoxy resin, urethane resin and epoxy resin.

Further, for example, 2, 4, 7
-Electron accepting substances such as trinitrofluorenone and tetracyanoquinodimethane, heterocyclic compounds such as carbazole, indole, imidazole, oxazole, pyrazole, oxadiazole, pyrazoline and thiadiazole, aniline derivatives, hydrazone compounds, aromatic amine derivatives And an electron donating substance such as a stilbene derivative or a polymer having a group consisting of these compounds in the main chain or side chain. In the case of the function separation type,
The thickness of the charge generation layer is preferably 10 μm or less, and particularly preferably 0.05 to 2 μm.

The charge transport layer in the present invention is formed by applying a coating solution obtained by dissolving a resin capable of forming a film of the charge transport material using an appropriate solvent, and drying. As the charge transport material in the photosensitive layer, for example, carbazole,
A compound having a heterocyclic ring such as indole, imidazole, thiazole, oxadiazole, pyrazole and pyrazoline, an aniline derivative such as phenylamine, diphenylamine and triphenylamine, a hydrazone derivative, a stilbene derivative and a group consisting of these compounds having a main chain or An electron donating substance such as a polymer having a side chain is exemplified. As the binder resin, a conventionally used resin for the charge transport layer can be used, and for example, a thermoplastic resin or a curable resin such as polycarbonate, polyester, polyarylate, acrylic resin, styrene resin, and silicone resin can be used. Can be.

Regardless of the layer constitution of the photosensitive layer, the binder resin of the layer immediately below the surface protective layer is a resin having alcohol resistance,
That is, it is necessary to use an alcohol-insoluble polymer, and polycarbonate, polystyrene, polyarylate, and a curable resin are preferable.

The thickness of the charge transport layer in the case of the function separation type and the thickness of the photosensitive layer in the case of the single layer photoreceptor are preferably 5 to 40 μm, and particularly preferably 10 to 30 μm.

In the present invention, examples of the conductive material used for the surface protective layer include metals, metal oxides, conductive polymers and carbon black. Examples of the metal include aluminum, zinc, copper, chromium, nickel, stainless steel, silver, and the like, and those obtained by depositing these metals on the surfaces of plastic particles. Examples of the metal oxide include zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, tin-doped indium oxide, antimony-doped tin oxide, and zirconium oxide. Examples of the conductive polymer include polyacetylene, polythiophene, and polypyrrole. These can be used alone,
Two or more kinds can be used in combination. When two or more types are used in combination, they may be simply mixed, or may be in the form of a solid solution or fusion.

The average particle size of the conductive material used in the present invention is 0.3 μm from the viewpoint of preventing light scattering.
m, particularly preferably 0.1 μm or less. Further, a metal oxide is more preferable in terms of transparency. In order to keep the strength of the protective layer strong, it is not preferable to mix fine particles.However, if the protective layer itself does not have a certain degree of conductivity, a photoconductor satisfying electrophotographic characteristics cannot be selected. It is preferable to include a conductive material so as to obtain the above-described resistance value.

The resistance of the protective layer of the present invention: R is 10 ¹² <R
It is preferable that ≦ 10 ¹⁴ Ω · cm. Resistance is 10 ¹²
When it is less than Ω · cm, it becomes difficult to hold the electric charge, and the image deletion is apt to occur. Conversely, if the resistance exceeds 10 ¹⁵ Ω · cm, the electric charge becomes difficult to move, the residual potential increases, and a low concentration and a negative ghost easily occur. Resistance can be measured as follows. First, a surface layer of the present invention having a thickness (T) of 4 μm is provided on a comb-shaped platinum electrode having an interelectrode distance (D) of 180 μm and a length (L) of 5.9 cm. Next, a DC voltage of 100 V (V) is applied between the comb electrodes.
The current value (I) when p is applied is pA (picoamps)
It measures with a meter and obtains resistance ρv by the following equation.

[0037]

(Equation 1)

Further, in the present invention, when a conductive material is contained in the surface protective layer in order to obtain an environmentally stable surface protective layer, a siloxane compound or a fluorine atom-containing compound is dispersed in the conductive particles. Sometimes added, or
It is necessary to mix conductive particles which have been previously subjected to surface treatment.

The protective layer of the present invention has a thickness of 0.2 to 10 μm.
It is particularly preferable that the thickness be 0.5 to 6 μm.

In the present invention, a lubricant may be contained in the surface layer for the purpose of improving the releasability, water repellency and surface lubricity of the surface layer. Lubricants used in the present invention include ethylene tetrafluoride resin, ethylene trifluoride chloride resin, hexafluoroethylene propylene resin, vinyl fluoride resin, vinylidene fluoride resin, ethylene difluoride ethylene chloride resin and the like. It is preferable to appropriately select one or more of the polymers, and particularly preferable are a tetrafluoroethylene resin and a vinylidene fluoride resin. The molecular weight of the resin particles and the particle size of the particles can be appropriately selected and are not particularly limited.

As the binder resin used for the surface protective layer and the like, a resin formed by three-dimensionally cross-linking to have sufficient mechanical strength is used. For reasons such as strength and resistance stability of the surface protective layer in a state where the conductive material and the charge transport material are contained, alcohol-soluble thermosetting resins such as phenolic resin, melamine resin, phosphazene resin and thermosetting acrylic resin are used. preferable.

In particular, alcohol-soluble phenolic resins,
When forming a surface protective layer using a thermosetting resin such as an alcohol-soluble melamine resin and a thermosetting acrylic resin, by using gallium phthalocyanine having the specific crystal form described above as a charge generation material in the photosensitive layer. In addition, sufficient mechanical strength of the surface protective layer formed by heat curing, and electrophotographic characteristics and environmental stability of the photosensitive layer can be achieved at the same time.

As the alcohol-soluble charge transporting material contained in the surface protective layer of the present invention, a charge transporting material modified with a hydroxyalkyl group or a hydroxyalkoxy group is used. Groups, hydroxypropyl groups, hydroxybutyl groups and hydroxymethyl groups are preferred, and hydroxyethyl groups, hydroxypropyl groups and dihydroxypropyl groups are particularly preferred. Further, among the hydroxyalkoxy groups, a hydroxyethoxy group, a hydroxypropoxy group, a hydroxybutoxy group and a hydroxymethoxy group are preferred, and a hydroxyethoxy group, a hydroxypropoxy group and a dihydroxypropoxy group are particularly preferred. The alcohol-soluble charge transporting materials that can be used in the present invention are illustrated below, but the present invention is not limited to these compounds.

[0044]

[Table 1]

[0045]

[Table 2]

[0046]

[Table 3]

[0047]

[Table 4]

As the solvent for the material for the surface protective layer of the present invention, an alcohol-containing solvent is used. As the alcohol in this case, for example, an alcohol such as benzyl alcohol containing an aromatic unit, which dissolves the photosensitive layer. Are not preferred, and alkyl alcohols are preferred. Particularly, methanol, ethanol, propanols, butanols, pentanols and hexanols having 6 or less carbon atoms are preferable, and methanol, ethanol, propanols and butanols are more preferable.

FIG. 1 shows a schematic configuration of an electrophotographic apparatus having a process cartridge having the electrophotographic photosensitive member of the present invention. In FIG. 1, reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member of the present invention, which is driven to rotate at a predetermined peripheral speed in the direction of an arrow with the shaft 2 stopped. In the rotation process, the photosensitive member 1 is uniformly charged with a predetermined positive or negative potential on its peripheral surface by the primary charging means 3, and then an image from an image exposure means (not shown) such as slit exposure or laser beam scanning exposure. The exposure light 4 is received. Thus, an electrostatic latent image is sequentially formed on the peripheral surface of the photoconductor 1. The formed electrostatic latent image is then subjected to toner development by the developing unit 5, and the developed toner developed image is transferred between the photoconductor 1 and the transfer unit 6 from a paper feeding unit (not shown).
Are transferred by a transfer unit 6 to a transfer material 7 taken out and fed in synchronization with the rotation of the sheet. The transfer material 7 having undergone the image transfer is separated from the photoreceptor surface, introduced into the image fixing means 8 and subjected to image fixation, so that it is printed out of the apparatus as a copy. The surface of the photoreceptor 1 after the image transfer is cleaned by removing the untransferred toner by the cleaning unit 9, and is further cleaned by a pre-exposure unit (not shown).
After being subjected to a static elimination process by the pre-exposure light 10 from, it is repeatedly used for image formation. When the primary charging unit 3 is a contact charging unit using a charging roller or the like, the pre-exposure is not necessarily required. In the present invention, among the above-described components such as the electrophotographic photosensitive member 1, the primary charging unit 3, the developing unit 5, and the cleaning unit 9, a plurality of components are integrally connected as a process cartridge. May be detachably attached to a main body of an electrophotographic apparatus such as a copying machine or a laser beam printer. For example, at least one of the primary charging unit 3, the developing unit 5, and the cleaning unit 9 is integrally supported together with the photoreceptor 1 to form a cartridge, which can be attached to and detached from the apparatus main body using a guide unit such as a rail 12 of the apparatus main body. The process cartridge 11 can be used. The image exposure light 4
When the electrophotographic apparatus is a copying machine or a printer, the original is read by reflected light or transmitted light from the original, or read by a sensor, converted into a signal, the laser beam scanning performed according to the signal, the driving of the LED array, and the like. Light emitted by driving a liquid crystal shutter array or the like.

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 RT printers, LED printers, liquid crystal printers, and laser plate making.

[Photoreceptor Example] Photosensitive Layer Example 1 An aluminum cylinder of φ30 mm × 260.5 mm was used as a support, and a 5% by mass methanol solution of a polyamide resin (trade name: Amilan CM8000, manufactured by Toray Industries, Inc.) was immersed therein. To form an undercoat layer having a thickness of 0.5 μm.

Next, 3 parts by mass of hydroxygallium phthalocyanine crystal and 2 parts by mass of polyvinyl butyral having the strongest peak at 28.1 ° of the Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction were combined with 100 parts by mass of cyclohexanone. And dispersed in a sand mill using 1 mmφ glass beads for 1 hour, and diluted with 100 parts by mass of methyl ethyl ketone to prepare a coating for a charge generation layer. The paint is applied by dip coating and dried at 90 ° C. for 10 minutes to give a film thickness of 0.15 μm.
m of the charge generation layer was formed.

Next, 10 parts by mass of a styryl compound of the following structural formula [formula 1]

[0054]

Embedded image And bisphenol Z type polycarbonate (trade name: Z
-200, manufactured by Mitsubishi Gas Chemical Co., Ltd.) was dissolved in 40 parts by mass of monochlorobenzene and 20 parts by mass of dichloromethane. This solution was applied onto the charge generation layer by a dip coating method, and was dried with hot air at 100 ° C. for 60 minutes.
A 0 μm charge transport layer was formed.

Photosensitive Layer Example 2 At least 7.4 °, 16.6 ° of Bragg angle 2θ ± 0.2 in CuKα characteristic X-ray, and 2
Photosensitive layer example 1 except that chlorogallium phthalocyanine having strong diffraction peaks at 5.5 ° and 28.3 ° was used.
A photosensitive layer was provided in the same manner as described above.

Photosensitive Layer Example 3 The photosensitive layer was prepared in the same manner as in Photosensitive Layer Example 1, except that a polyarylate resin having a weight average molecular weight of 80,000 represented by the following structural formula [Formula 2] was used as the binder resin for the charge transport layer. Provided.

[0057]

Embedded image

Photosensitive Layer Example 4 A photosensitive layer was provided in the same manner as in Photosensitive Layer Example 1, except that the charge generation layer was formed as follows. That is, the following structural formula [Formula 3]

[0059]

Embedded image Are dispersed in a sand mill using 1 mmφ glass beads for 10 hours, and 10 parts by mass of a polyvinyl butyral resin (trade name: Eslec BL-S, manufactured by Sekisui Chemical Co., Ltd.) and 100 parts by mass of tetrahydrofuran are dispersed in a sand mill for 1 hour. A paint for a charge generation layer was prepared, and the paint for a charge generation layer was applied onto the undercoat layer by dip coating and dried at 80 ° C. for 15 minutes to form a charge generation layer having a thickness of 0.15 μm.

Photosensitive Layer Example 5 Except that the copolymer of vinylphenol / styrene = 50/50 (Markarinka-CST50 grade, manufactured by Maruzen Oil Co., Ltd.) was used as the binder resin of the charge transport layer in Example 1 of the photosensitive layer. Similarly, a photosensitive layer was provided.

Protective Layer Coating Example 1 Conductive material subjected to a surface treatment (treatment amount: 8.5% by mass) with a methylhydroxysiloxane compound (KF-99, manufactured by Shin-Etsu Chemical Co., Ltd.): antimony-containing tin oxide fine particles ( 50 parts by mass of T-1 (manufactured by Mitsubishi Materials Corporation) and 150 parts by mass of ethanol were dispersed in a sand mill for 68 hours, and then a phenol resin (trade name: PL-480)
4, Gunei Chemical Co., Ltd.) was dissolved as a resin component in an amount of 31 parts by mass to prepare a coating for a protective layer.

Protective Layer Coating Example 2 Conductive material subjected to surface treatment (treatment amount: 7% by mass) with (3,3,3-trifluoropropyl) trimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.): containing antimony 51 parts by mass of tin oxide fine particles (trade name: T-1, manufactured by Mitsubishi Materials Corporation) and 150 parts by mass of ethanol were dispersed in a sand mill for 66 hours, and then polytetrafluoroethylene fine particles (average particle size: 0.18 μm) 20 A part by mass was added and the mixture was dispersed for 20 minutes. Then, the phenol resin (trade name: PL
-4804, manufactured by Gunei Chemical Co., Ltd.)
Parts by mass were dissolved to give a coating for a protective layer.

Protective Layer Coating Example 3 Conductive material subjected to surface treatment (treatment amount: 7% by mass) with (3,3,3-trifluoropropyl) trimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.): containing antimony Disperse 50 parts by mass of tin oxide fine particles (trade name: T-1, manufactured by Mitsubishi Materials Corporation), 23 parts by mass of acrylic resin (Colorad DPHA, manufactured by Nippon Kayaku Co., Ltd.) and 150 parts by mass of ethanol in a sand mill for 66 hours. Then, 20 parts by mass of polytetrafluoroethylene fine particles (average particle size: 0.18 μm) were added, and the mixture was dispersed for 20 minutes to obtain a coating for a protective layer.

Protective Layer Coating Example 4 Conductive material subjected to surface treatment (treatment amount: 7% by mass) with (3,3,3-trifluoropropyl) trimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.): containing antimony 50 parts by mass of tin oxide fine particles (trade name: T-1, manufactured by Mitsubishi Materials Corporation), 39 parts by mass of melamine resin (Cymel 701, manufactured by Mitsui Cytec Co., Ltd.) and 150 parts by mass of ethanol were taken in a sand mill for 66 hours. Disperse, and further, polytetrafluoroethylene fine particles (average particle size 0.18 μm)
20 parts by mass were added and dispersed for 20 minutes to obtain a protective layer paint.

Protective Layer Coating Example 5 80 parts by mass of a phenolic resin (trade name: PR-53123, manufactured by Sumitomo Durez Co., Ltd.) and 30 parts by mass of a charge transporting material [formula 4] represented by the following structure, and 200 parts by mass of ethanol The resulting mixture was diluted in a portion to give a coating for a protective layer.

[0066]

Embedded image

Protective Layer Coating Example 6 A protective layer coating example 5 was prepared in the same manner as in the protective layer coating example 5, except that the charge transporting material was replaced by a charge transporting material represented by the following structural formula.

[0068]

Embedded image

Protective Layer Coating Example 7 A protective layer coating example 5 was prepared in the same manner as in the protective layer coating example 5, except that the charge transporting material was replaced by a charge transporting material represented by the following structural formula [Formula 6].

[0070]

Embedded image

Protective Layer Paint Example 8 A protective layer paint example 8 was prepared in the same manner as in the protective layer paint example 5, except that the charge transport material was replaced by a charge transport material represented by the following structural formula [Formula 7].

[0072]

Embedded image

Protective Layer Coating Example 9 20 parts by mass of polytetrafluoroethylene fine particles (average particle size: 0.18 μm) were added to the protective layer coating solution 5 and dispersed for 20 minutes to prepare a protective layer coating.

Protective Layer Coating Example 10 50 parts by mass of antimony non-doped non-conductive tin oxide fine particles surface-treated (8% by mass) with a methylhydroxysiloxane compound (KF-99, manufactured by Shin-Etsu Chemical Co., Ltd.) And 150 parts by mass of ethanol
Disperse for 6 hours, then phenol resin (trade name: P
L-4804, manufactured by Gunei Chemical Co., Ltd.)
2 parts by mass were dissolved to give a coating for a protective layer.

Protective Layer Coating Example 11 Conductive material subjected to surface treatment (treatment amount: 8% by mass) with a methylhydroxysiloxane compound (KF-99, manufactured by Shin-Etsu Chemical Co., Ltd.): antimony-containing tin oxide fine particles (trade name) T
-1, Mitsubishi Materials Corporation) 50 parts by mass, 100 parts by mass of methyl ethyl ketone and 50 parts by mass of tetraethylfuran are dispersed in a sand mill for 66 hours, and then a phenol resin (trade name: PL-4804, Gunei Chemical Co., Ltd.) )
Was dissolved as a resin component in an amount of 28 parts by mass to prepare a coating for a protective layer.

Protective Layer Coating Example 12 A phenol resin (trade name: P
L-2475, manufactured by Gunei Chemical Co., Ltd.) was dissolved in an amount of 42 parts by mass to prepare a coating for a protective layer.

Protective Layer Coating Example 13 80 parts by mass of a phenolic resin (trade name: PR-53123, manufactured by Sumitomo Durez Co., Ltd.) were diluted with 200 parts by mass of ethanol, and the alcohol-insoluble charge represented by the following structure [formula 8] was obtained. 30 parts by mass of the transport material was added to obtain a coating for the protective layer.

[0078]

Embedded image

Electrophotographic Photoreceptor Example 1 The photosensitive layer prepared in Photosensitive Layer Example 1 was dip-coated using the paint of Protective Layer Paint Example 1 and then heat-cured at 150 ° C. for 1 hour to give a film thickness of 3 An electrophotographic photosensitive member was prepared by providing a surface protective layer having a thickness of 0.0 μm.

Examples and Comparative Examples of Electrophotographic Photoreceptor As shown in Table 1, photosensitive layer examples 1 to 5 and protective layer coating examples 1 to 5
13 was used to form a surface protective layer by dip coating and heat curing in the same manner as in Example 1 of the electrophotographic photoreceptor.

[0081]

[Table 5] Table 1 Example of preparation of electrophotographic photoreceptor

Measurement of Volume Resistance of Surface Protective Layer A comb-shaped electrode having a gap of 180 μm was formed on a polyethylene terephthalate sheet by gold vapor deposition, and coatings 1 to 4 and 10 to 14 for the protective layer were applied thereon, followed by heat treatment. Was applied to form a 3 μm film, and measurement was performed by applying 100 V using a PA meter 4140B manufactured by Yokogawa Hewlett-Packard Co., Ltd. Temperature / humidity of 23 ℃ / 50% and 30 ℃
The measurement was carried out after standing for 1 day in two environments of / 80%.

[0083]

Table 6 Volume resistance of surface protective layer

Evaluation of Electrophotographic Photoreceptor The electrophotographic photoreceptors prepared in the above Examples and Comparative Examples were manufactured using a laser jet 400 manufactured by Hewlett-Packard Co., Ltd.
0 (roller contact charging, AC / DC application), and the quality of the output image was confirmed in an environment of a temperature of 23 ° C., a humidity of 50%, and a temperature of 30 ° C. and a humidity of 80%.

Further, an endurance test for 7000 sheets was conducted in an environment at a temperature of 23 ° C. and a humidity of 50%, and the output image after the endurance test and the shaving amount of the electrophotographic photosensitive member were measured.

As summarized in Table 3, Examples 1 to
With the photoreceptor No. 12, good quality images could be obtained even under high temperature and high humidity, and the images after the durability test also maintained high quality and the amount of scraping of the photoreceptor was extremely small.

On the other hand, in Comparative Examples 1 and 3, charges could not move in the surface protective layer, and a desired image could not be obtained. Further, in Comparative Examples 2 and 6, the surface protective layer was applied by applying the surface protective layer.
Migration occurred between the photosensitive layers, which hindered the electrophotographic characteristics. In Comparative Example 8, the image quality before the durability test was good, but since no surface protective layer was provided,
The surface was deteriorated due to poor strength and durability. Comparative Example 4
Although the strength of the surface protective layer was sufficient, the photosensitive layer was severely deteriorated due to the heat treatment during the formation of the surface protective layer, causing a decrease in sensitivity and an increase in residual potential. Conversely, in Comparative Example 5,
Although the heat treatment conditions of the surface protective layer were mild, there was no problem in sensitivity and residual potential, but image deterioration under high humidity due to poor curing of the surface protective layer and surface deterioration due to durability were observed. Furthermore, in Comparative Example 7, since the charge transport material in the surface protective layer did not have a hydroxyalkyl group or a hydroxyalkoxy group-having alcoholic group and could not be dissolved in the protective layer paint,
The charge transporting material was deposited in the surface protective layer, and there were points where charge transport was not performed uniformly, and many white spots were generated.

[0088]

[Table 7] Table 3 Evaluation results of electrophotographic photoreceptor

[0089]

As described above, according to the present invention,
In an electrophotographic photosensitive member having at least a photosensitive layer and a surface protective layer on a conductive support, the photosensitive layer contains a phthalocyanine having a gallium atom at its center as a charge generating material, and a photosensitive layer immediately below the surface protective layer. Contains an alcohol-insoluble polymer as a binder resin, and the paint used for forming the surface protective layer contains at least one of a conductive material and an alcohol-soluble charge transport material and an alcohol, thereby increasing the residual potential and decreasing the sensitivity. Thus, an electrophotographic photoreceptor having a sufficient strength can be provided without causing a problem, and a high-durability, high-stability, and good image can be obtained.

Further, the process cartridge having the electrophotographic photoreceptor and the electrophotographic apparatus also have remarkable effects.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a schematic configuration of an electrophotographic apparatus having a process cartridge having an electrophotographic photosensitive member of the present invention.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 5/147 504 G03G 5/147 504 (72) Inventor Koichi Nakata 3-30-2 Shimomaruko, Ota-ku, Tokyo No. Canon Inc. (72) Inventor Hiroshi Saito 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Hideyuki Takai 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Stocks In-house F-term (reference) 2H068 AA03 AA05 AA13 AA19 AA20 BA03 BA05 BA12 BA39 BA60 BB10 BB25 BB27 BB31 BB33 BB50 BB58 EA14 EA19 FA19 FA27

Claims (10)

[Claims] 1. An electrophotographic photoreceptor having at least a photosensitive layer and a surface protective layer on a conductive support, wherein the photosensitive layer contains a phthalocyanine having a gallium atom at its center as a charge generating material. The immediately lower photosensitive layer contains an alcohol-insoluble polymer as a binder resin,
An electrophotographic photoreceptor, wherein the paint used for forming the surface protective layer contains at least one of a conductive material and an alcohol-soluble charge transport material and an alcohol. 2. The electrophotographic photosensitive member according to claim 1, wherein the conductive material is metal fine particles or metal oxide fine particles. 3. The surface protective layer contains at least one of a fluorine atom-containing compound and a siloxane compound.
Or the electrophotographic photosensitive member according to 2. 4. The electrophotographic photosensitive member according to claim 1, wherein the alcohol-soluble charge transporting material has at least one or both of a hydroxyalkyl group and a hydroxyalkoxy group. 5. A phthalocyanine-based charge-generating material having a gallium atom at its center has hydroxygallium phthalocyanine or Bragg angle 2θ having the strongest peak at 28.1 ° of Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction. At least 7.4 ° of ± 0.2 °, 16.
5. The electrophotographic photoreceptor according to claim 1, which is chlorogallium phthalocyanine having strong peaks at 6 °, 25.5 ° and 28.3 °. 6. The electrophotographic photoreceptor according to claim 1, wherein the surface protective layer is formed by heating and forming a film of a binder resin containing an alcohol-soluble thermosetting resin as a main component. 7. The electrophotographic photosensitive member according to claim 6, wherein the alcohol-soluble thermosetting resin is a phenol resin. 8. The electrophotographic photosensitive member according to claim 1, wherein the surface protective layer contains at least one selected from the group consisting of silicone resin fine particles, silicon fine particles and fluorine-containing resin fine particles. 9. An electrophotographic photoreceptor according to claim 1 and at least one means selected from the group consisting of a charging means, a developing means and a cleaning means are integrally supported, and are detachably attached to an electrophotographic apparatus main body. A process cartridge, comprising: 10. The electrophotographic photoreceptor according to claim 1, wherein
An electrophotographic apparatus comprising a charging unit, an image exposing unit, a developing unit, and a transferring unit.