JPH08202062A - Electrophotographic photoreceptor, electrophotographic device and device unit - Google Patents

Abstract

PURPOSE: To provide a photoreceptor in which silica particles are used and to provide a photoreceptor which hardly causes adsorption of water molecules, namely, gives excellent images even in high humidity environment and has excellent electric characteristics for repeated use by incorporating specified silica particles into the outermost layer. CONSTITUTION: The outermost layer of an electrophotographic photoreceptor contains silica particles having the following properties. By the differential scanning calorimetry for the particles in an environment of 80% relative humidity, the endothermic energy change ΔH in the region between >=40 deg.C and <=200 deg.C is 0-20J/g. The volume average particle size of the particles is between >=0.05μm and <=2μm. The silica particles are synthesized by chemical flame CVD method and treated with a silica coupling agent expressed by formula. In formula, R1 is a halogen atom, alkyl group, alkenyl group or the like and it may have substituents, and R2 -R4 are halogen atoms, alkyl groups or alkoxy groups.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor containing silica particles in the outermost surface layer of the photoreceptor, and more particularly to an electrophotographic photoreceptor having excellent durability.

The present invention also relates to an electrophotographic apparatus and an apparatus unit having the above-mentioned photoconductor.

[0003]

2. Description of the Related Art Generally, in order to form an image by an electrophotographic method, a toner image is formed on a surface of a photoconductor by charging, imagewise exposing and developing the toner image, and the toner image is transferred and fixed on a transfer material to form an image. After the transfer, the photosensitive member after the transfer is cleaned and removed of residual toner, and is repeatedly used for a long period of time.

Therefore, the photoconductor has not only electrophotographic performance such as charging potential, sensitivity, dark decay and residual potential characteristics, but also
It is also required to have good physical properties such as printing durability, abrasion resistance, and moisture resistance during repeated use, and resistance to ozone and image exposure generated during corona discharge.

On the other hand, as an electrophotographic photosensitive member, an inorganic photoconductive photosensitive member using amorphous silicon, selenium, cadmium sulfide, etc. has been widely used as a conventional electrophotographic photosensitive member, but in recent years, it is low in cost, nontoxic, and easy to process. Organic photoconductive photoreceptors (hereinafter simply referred to as organic photoreceptors) that are excellent and have a high degree of freedom in selection according to the purpose have become the mainstream.

Fatigue deterioration due to repeated use of these electrophotographic photosensitive members is caused by the steps of transferring a toner image formed on the photosensitive member onto a transfer material, separating and cleaning residual toner on the photosensitive member after transfer. It is said that the surface of the photosensitive layer is rubbed and damaged due to the rubbing, and the surface of the photosensitive body is decomposed and deteriorated in each step such as charging, image exposure and charge removal of the surface of the photosensitive body.

Therefore, in order to prevent the fatigue deterioration of the photoconductor, the improvement of the photosensitive layer surface is an important issue. In particular, the photosensitive layer of the organic photoconductor is softer than the inorganic photoconductor, and since the photoconductive substance is organic, fatigue deterioration is large during repeated use of the photoconductor, and the improvement of the surface of the photoconductive layer is Becomes more important.

Therefore, in JP-A-56-117245, JP-A-63-91666 and JP-A-1-205171, silica particles are contained in the outermost surface layer of the photoconductor to improve the mechanical strength of the photoconductor surface. It is described that it is large and the durability can be improved. Furthermore, in JP-A-57-176057, JP-A-61-117558, JP-A-3-155558 and the like, hydrophobic silica particles obtained by treating the silica particles with a silane coupling agent are disclosed in It is described that by containing it in the outermost surface layer, the mechanical strength of the photoconductor is increased and the lubricity is imparted to obtain a photoconductor having higher durability.

[0009]

The silica particles that have been conventionally used in the protective layer of electrophotographic photoreceptors include silica sol and colloidal silica synthesized by the sol-gel method in the liquid phase, and silica obtained in the gas phase. Ultrafine particles are known. However, due to the manufacturing method, silica sol and colloidal silica synthesized by the so-called sol-gel method in the liquid phase, the particle surface is rich in silanol groups having a strong affinity for polar molecules such as water molecules. Furthermore, since the particles have a small particle size of a few μm or less and are difficult to sinter at high temperatures, they have a large internal surface area and a porous surface, and gas molecules such as water molecules are easily adsorbed.

On the other hand, ultrafine particles of silica called fumed silica usually have a small particle size of 10 to 40 nm and a large specific surface area, so that gas molecules such as water molecules are easily adsorbed.

For this reason, the photoconductors using these silicas are apt to adsorb gas molecules, especially water molecules, and there is a problem in an image in a high humidity environment and electric characteristics during repeated use. Therefore, in order to solve these problems, particles in which gas molecules, particularly water molecules, are less likely to be adsorbed are required.

An object of the present invention is to provide an electrophotographic photosensitive member using silica particles which is less likely to adsorb water molecules, that is, which has excellent electric characteristics during image and repeated use even in a high humidity environment. .

Another object of the present invention is to use a cleaning blade which is brought into contact with the photosensitive member in combination with the photosensitive member under a specific condition as a cleaning means. Another object of the present invention is to provide an electrophotographic photosensitive member which is free from abrasion and damage, has high durability, and which can stably obtain a high density and clear image from beginning to end, and an electrophotographic apparatus using the same.

Still another object of the present invention is that since the photoreceptor incorporated therein has a high durability, it is possible to repeatedly and stably form an image without exchanging the photoreceptor. An object of the present invention is to provide a device unit that can be quickly and easily replaced even if a defect occurs in the image forming means other than the body, and can stably obtain a high-quality image for a long period of time.

[0015]

The above-mentioned objects of the present invention can be achieved by adopting any of the following constitutions.

(1) The amount of change in endothermic energy ΔH in the range of 40 ° C. or more and 200 ° C. or less is 0 in the differential scanning calorimetric analysis in the outermost surface layer of the electrophotographic photosensitive member when humidity is controlled in an environment of relative humidity of 80%. An electrophotographic photoreceptor comprising silica particles having a volume average particle diameter of 0.05 μm or more and 2 μm or less, the content of which is ˜20 Joules / g.

(2) The electrophotographic photosensitive member according to (1), wherein the silica particles are synthesized by a chemical flame CVD method.

(3) The silica particles have a temperature of 40 ° C. or more and 200 or more in a differential scanning calorimetric analysis in an environment of relative humidity 80%
The electrophotographic photosensitive member according to (1) or (2), characterized in that the amount of change in energy ΔH of the endothermic peak at 0 ° C or less is 0 to 10 Joules / g.

(4) The electrophotographic photoreceptor according to (1), (2) or (3), wherein the silica particles are treated with a silane coupling agent represented by the following general formula.

[0020]

Embedded image

(Wherein R _{1 represents a} halogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, an alkyloxy group, an alkenyloxy group, a cycloalkyloxy group, an aryloxy group, an acyl group or an acyloxy group. R _{2 to} R _{4 are a} halogen atom, an alkyl group or an alkoxy group.) (5) Electrophotography in which a photosensitive layer is provided on a conductive support. In the differential scanning calorimetry analysis when the humidity was adjusted to the outermost surface layer of the photoconductor in the environment of 80% relative humidity, the amount of endothermic energy change ΔH in the range of 40 ° C to 200 ° C was 0 to 20 Joules / g. And a photoreceptor containing silica particles having a volume average particle diameter of 0.05 μm or more and 2 μm or less, latent image forming means for forming an electrostatic latent image on the photoreceptor, and an electrostatic latent image formed on the photoreceptor. Manifest A developing means for converting the toner image into a toner image, a transferring means for transferring the toner image on the photoconductor obtained by visualization to a transfer material, and a cleaning means for cleaning the toner remaining on the photoconductor after the toner image transfer. An electrophotographic device characterized in that

(6) The electrophotographic apparatus according to (5), wherein the cleaning means is an elastic blade cleaning means.

(7) The cleaning blade of the cleaning means is 5 in the counter direction with respect to the photosensitive member.
The electrophotographic apparatus according to (6), wherein the electrophotographic apparatus is cleaned by being pressed with a pressing force of -50 (g / cm).

(8) Relative humidity of 80 is applied to the outermost surface layer of the photoreceptor.
In differential scanning calorimetry when humidity is controlled under
Change in endothermic energy ΔH in the range of 40 ℃ to 200 ℃
Is 0 to 20 Joules / g, and the volume average particle size is 0.05μ
A photoconductor containing silica particles of m or more and 2.0 μm or less, a charging unit for uniformly charging the photoconductor, a developing unit for visualizing an electrostatic latent image on the photoconductor, and a photoconductor on the photoconductor. At least one of transfer means for transferring the visualized toner image onto a transfer material, charge removing means for removing charges on the photoconductor after transfer, and cleaning means for cleaning residual toner on the photoconductor after transfer. An apparatus unit in which a tongue is integrally supported and is detachably attached to the apparatus body.

(9) The apparatus unit according to (8), wherein an elastic cleaning blade is used as the cleaning means, and at least the cleaning blade and the photosensitive member are integrally supported and are detachably attached to the apparatus main body.

One of the essential constituents of the silica particles of the present invention is a silica particle having a ΔH at 40 to 200 ° C. of 0 to 20 joules / g, preferably 10 joules / g or less. Since the body absorbs little gas molecules, especially water molecules, a good image can be obtained even in a high humidity environment, and the potential stability upon repeated use is excellent.

The ΔH in the present invention is most preferably measured by controlling the humidity in an environment of 80% RH and then performing differential scanning calorimetry under the same conditions, but the actual analysis itself is under the condition of 80% RH for about 24 hours. If the humidity is adjusted under the temperature and then measured within 60 minutes, a constant value can be obtained.

In a preferred embodiment of the photoreceptor, the silica is substantially spherical particles and a chemical flame is used.
It is manufactured by the CVD method.

In another preferred embodiment, the hydrophobic silica particles are used in which the silica particles are hydrophobized. In still another preferred embodiment, the outermost surface layer of the photoreceptor is a protective layer, and the silica particles are contained in the protective layer. Further, the protective layer may contain a charge transport substance.

The above object of the present invention is to provide an electrophotographic photoreceptor, an electrostatic latent image forming means for forming an electrostatic latent image on the photoreceptor, a developing means for developing the formed electrostatic latent image, In an electrophotographic apparatus having a transfer means for transferring a toner image obtained by development by the means onto a transfer material and a cleaning means for cleaning residual toner on the photoconductor after the transfer, an elastic cleaning blade is used as the cleaning means. It is achieved by an electrophotographic device characterized by being used.

In a preferred embodiment of the electrophotographic apparatus, the cleaning blade is pressed against the photosensitive member with a pressing force of 5 to 50 g / cm in the counter direction for cleaning.

Still further, the above-mentioned object of the present invention is an apparatus unit having at least two or more of an electrophotographic photoreceptor, a charging means, a developing means, a transfer means, a discharging means and a cleaning means, and the photoreceptor and At least one of a charging unit, a developing unit, a transfer unit, a charge removing unit, and a cleaning unit is integrally supported, and is detachably attached to the main body of the device.

In a preferred embodiment of the apparatus unit, an elastic cleaning blade is used as the cleaning means, at least the cleaning blade and the photoconductor are integrally supported, and detachable from the apparatus body. .

The outermost surface layer of the photoconductor of the present invention refers to a layer constituting the outermost surface when the electrophotographic photoconductor of the present invention is manufactured, for example, a protective layer provided on the photosensitive layer. ,
Alternatively, when the protective layer is not provided, it is the photosensitive layer forming the outermost surface, and among them, it is preferably the charge transport layer (CTL). The protective layer preferably further contains a charge transport substance (CTM) in addition to the silica particles of the present invention. The outermost surface layer in the present invention is the silica particles of the present invention and CTM optionally contained, and other additives dispersed in a binder resin (described later),
It is provided by means such as coating.

Another essential constituent requirement of the silica particles of the present invention is that the volume average particle diameter thereof is 0.05 μm or more and 2 μm or less, preferably 0.1 μm or more and 2 μm or less, and those having a sharp particle size distribution are preferable. .

The volume average particle diameter of the silica particles is 0.05 μm
If it falls below the range, the mechanical strength required for the photosensitive layer surface cannot be obtained,
It is easily worn and damaged during repeated image formation, and electrophotographic performance is deteriorated. On the other hand, if it exceeds 2 μm, the surface roughness of the photosensitive layer becomes large, and cleaning failure occurs.

By the way, in recent years, high image quality has been demanded in the electrophotographic industry, and therefore, the average particle size of 10 μm as a developing toner.
The following fine particle toners have come to be used. In such a case, it is particularly important to control the surface roughness of the photosensitive layer surface in order to obtain a sufficient cleaning effect.

In the present invention, the preferable volume average particle diameter of the silica particles is sufficient for the fine particle toner.
It is set to 0.1 μm or more and 2 μm or less.

Further, the silica particles are preferably substantially spherical, and particularly preferably substantially spherical with a major axis / minor axis ratio of less than 2.0. Here, the spherical shape means an electron microscope. It is shown that the particles expanded 10,000 times are spherical rather than amorphous. In that case, it is possible to reduce the friction coefficient of the surface of the photosensitive layer, and it is possible to prevent reversal (blade flipping) of the elastic cleaning blade, which has been a problem in the related art. In addition, it is preferable that the silica particles have a sharp particle size distribution, in which case the occurrence of film defects due to the inclusion of coarse particles on the surface of the photosensitive layer or the agglomeration of small particles is prevented.

As a method for producing the silica particles of the present invention, a chemical flame CVD method (CVD: Chemical Valpor Deposition) is preferable. This method is a method of producing a high-temperature flame by burning an oxygen-hydrogen mixed gas or a hydrocarbon-oxygen mixed gas, in which a gas phase reaction is caused to produce, and as an example, chlorosilane gas is used as the mixed gas. There is a method of obtaining silica particles by performing a gas phase reaction in a high temperature flame.

The silica particles according to the present invention are the chemical flame CVD.
It is preferably produced by a method, but among them, it is preferable to introduce the metal silicon powder into the mixed gas and explosively combust and react.

Details of this production method are described in, for example, JP-A-60-25560.
No. 2, JP-A-5-193908, No. 5-193909, and No. 5-139910
No. 5-139928, No. 5-196614, and No. 6-107406.

In the production method described in the above-mentioned publications, the raw material silicon metal material is washed with high-purity water a plurality of times in advance to remove dissolved components, and at the same time, heat treatment is performed to remove gas phase components and increase the temperature. A fine silicon powder is obtained. Next, combustible gas such as LPG and supporting gas such as oxygen gas are introduced into the burner at the head of the manufacturing apparatus to form a flame for ignition, and the high-purity silicon powder is added to the flame for ignition. A carrier gas such as air dispersedly contained is introduced to start ignition and combustion. After that, the combustion-supporting gas is supplied in multiple stages to explosively oxidize and burn the silicon powder to obtain high-purity silica particles.

According to the above-mentioned manufacturing method, it is possible to obtain high-purity silica fine particles having a sharp particle size distribution, and it is possible to manufacture by varying the particle size distribution in a wide range according to the purpose. .

The volume average particle diameter of the silica particles is measured by a laser diffraction / scattering type particle size distribution measuring apparatus LA-700 (manufactured by Hikiba Seisakusho).

The silica particles used in the present invention are, for example, titanium coupling agents, silane coupling agents,
Hydrophobic silica particles treated with a hydrophobizing agent such as an aluminum coupling agent, a polymeric fatty acid or a metal salt thereof are more preferable.

1. Silane Coupling Agent The silane coupling agent used in the present invention is not particularly limited, but a silane coupling agent represented by the following general formula is preferably used.

[0048]

Embedded image

(Wherein R _{1 represents a} halogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, an alkyloxy group, an alkenyloxy group, a cycloalkyloxy group, an aryloxy group, an acyl group or an acyloxy group. R _{2 to} R _{4 are a} halogen atom, an alkyl group or an alkoxy group.) The alkyl group is an alkyl group having 1 to 12 carbon atoms, preferably methyl. , Ethyl, propyl, butyl, octyl,
It is each group of dodecyl. Further, the cycloalkyl group includes a cyclopentyl group, a cyclohexyl group and the like.

The alkenyl group is preferably a vinyl group, an allyl group or the like, and the aryl group is preferably a phenyl group, a tolyl group or a naphthyl group, and these groups may further have a substituent. As the substituent, for example, a halogen atom, an amino group, an alkyl group, an aryl group, an alkenyl group, an alkoxy group, an acyl group, an acyloxy group, an epoxy group, a mercapto group, or the like is preferable.

Specific examples of the silane coupling agent preferably used in the present invention are shown below.

[0052]

[Chemical 4]

In addition to these silane coupling agents, for example, polymer type silane coupling agents represented by the following general formula are also used.

[0054]

Embedded image

(In the formula, X is an alkoxysilyl group, Y is a reactive organic functional group such as an epoxy group, a hydroxyl group, an acryl group and a methacryl group, and Z is a compatibilizing unit with an organic group such as polyether, polyester and aralkyl. It is desirable that the material has good compatibility with the binder resin of the carrier transport layer. Titanium Coupling Agent As the titanium coupling agent, those having various structures are used, and specific examples thereof include the following.

Isopropyltriisostearoyl titanate Isopropyltris (dioctyl pyrophosphate)
Titanate Isopropyltri (N-aminoethyl-aminoethyl) titanate Tetraoctyl bis (ditridecyl phosphite) Titanate Tetra- (2,2-diallyloxymethyl-1-butyl) bis (didodecyl) phosphite Titanate Bis (dioctyl pyrophosphate) ) Oxyacetate titanate bis (dioctyl pyrophosphate) ethylene titanate isopropyl trioctanoyl titanate isopropyl dimethacryl isostearoyl titanate isopropyl tridodecylbenzenesulfonyl titanate isopropyl isostearoyl diacryl titanate isopropyl tri (dioctyl phosphate) titanate isopropyl tricumylphenyl titanate tetraisopropyl bis (Dioctyl phosphite) titanate . Aluminum Coupling Agent As the aluminum coupling agent, those having various structures can be used, but specifically, those represented by the following general formula are used.

[0057]

[Chemical 6]

(Wherein D, E and F represent an alkyl group having 1 to 6 carbon atoms and G represents an alkyl group or an alkenyl group having 1 to 24 carbon atoms. The alkyl group in D, E and F is a side chain. And preferably D and E are isopropyl groups and F is a methyl group.Each group in G may also have a side chain, and preferably has 8 to 24 carbon atoms. Although these coupling agents may be used by being mixed with a binder resin, it is preferable to use silica particles which have been surface-treated with a coupling agent in advance. As a result, the affinity between the particle surface of the present invention and the binder resin is increased, and the dispersibility and adhesiveness can be improved.

The amount of the coupling agent used is 0.1 to 100 parts by weight, preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the particles. Generally, the theoretical amount for sufficiently covering the surface is represented by the following formula. It can be calculated. However, the theoretical amount is the amount necessary to form a monolayer on the surface of the particles.

[0060]

[Equation 1]

(Ws: Amount of silane coupling agent added (g) Wf: Amount of fine particles used (g) SE: Specific surface area of fine particles (m ² / g) MCA: Minimum coating area per 1 g of silane coupling agent (m ² / g)) Actually, based on this value, the processing amount can be set according to the application.

Since the hydrophobic treatment film applied to the silica particles is a monomolecular layer or a thin layer close thereto, the amount of impurities and the volume average particle diameter of the hydrophobic silica particles are substantially the same as those before the hydrophobic treatment. The same as that of the silica particles.

The hydrophobic treatment is achieved by reacting the silanol groups on the silica surface with a hydrophobic substance by a chemical reaction. As a treatment method, for example, a method of reacting silanol groups with trimethylchlorosilane under high pressure (Koll
oid-Z, 149,39 (1956)), esterification with alcohol (DB
Esterification in an autoclave, (Bull.
Chem.Soc. Jpn, 49 (12), 3389 (1976)) and the like are known, but a treatment method with a silane coupling agent is generally used. For the treatment method with the silane coupling agent, for example, "silane coupling agent" (Shin-Etsu Chemical Co., Ltd.),
It can be performed by the method described in "Technical data No. Z003" (Toshiba Silicone) or the like.

In the present invention, these silica particles are contained at least in the outermost surface layer of the electrophotographic photoreceptor together with the binder. The proportion of silica particles in the outermost surface layer is usually 1% by weight or more and 200% by weight or less with respect to the binder. It is preferably used in an amount of 5% by weight or more and 100% by weight or less.

The outermost surface layer of the present invention may be a photosensitive layer located on the outermost surface of the electrophotographic photosensitive member, or may be a protective layer laminated thereon.

The photosensitive layer of the electrophotographic photosensitive member of the present invention containing the silica particles in the outermost layer may be an inorganic photosensitive member using selenium, amorphous silicon, cadmium sulfide, etc., but is preferably Organic charge generation material (CG
M) and a charge transport material (CTM). The layer structure of the organic photoreceptor is shown in FIG.

FIG. 1A shows an intermediate layer 2 on a conductive support 1.
1 is a photoreceptor having a single-layer photosensitive layer 6 containing both a charge-generating substance (CGM) and a charge-transporting substance (CTM) via an intermediate layer 2 on a conductive support 1. Charge transport layer (CTL) containing a charge transport material (CTM) as a main component via
And a charge generation layer (CGL) 4 containing a charge generation material (CGM) as a main component, and a photosensitive layer 6 formed in this order. FIG. And a photoconductive layer 6 formed by laminating a charge generation layer (CGL) 4 and a charge transport layer (CTL) 3 in this order via an intermediate layer.

Further, FIGS. 1 (d), (e), and (c) show the protective layer 5 on the photosensitive layer of FIGS. 1 (a), (b), and (c), respectively.
The structure which laminated | stacked is shown. Above (a), (b), (c),
Each of (d), (e) and (f) shows a typical constitution of the organic photoconductor, and the present invention is not limited to these layer constitutions. For example, the intermediate layer 2 shown in these figures may be omitted if not necessary.

Of the above-mentioned layer constitutions, the most preferable embodiment of the present invention is that a protective layer 5 is further laminated on the photosensitive layer as shown in (d), (e) and (f), and In which the silica particles of the present invention are contained.

The protective layer, if provided, is composed of at least a resin and the silica particles of the present invention, but it is more preferable that the protective layer contains a charge transport substance (CTM). Inclusion of a charge transport material (CTM) in these protective layers can prevent an increase in residual potential and a decrease in sensitivity due to repeated use of the electrophotographic photosensitive member.

Examples of the charge generating substance (CGM) contained in the photosensitive layer 6 of each of the photoreceptors shown in FIGS. 1 (a) to 1 (f) are, for example, phthalocyanine pigments, polycyclic quinone pigments, azo pigments, perylene pigments and indigo pigments. Pigments, quinacridone pigments, azurenium pigments, squarylium dyes, cyanine dyes, pyrylium dyes, thiopyrylium dyes, xanthene dyes, triphenylmethane dyes, styryl dyes, and the like, and these charge generating substances (CGM) alone or in a suitable binder. Layer formation is performed together with the resin.

The charge transport material (C
(TM), for example, oxazole derivative, oxadiazole derivative, thiazole derivative, thiadiazole derivative, triazole derivative, imidazole derivative, imidazolone derivative, imidazoline derivative, bisimidazolidine derivative, styryl compound, hydrazone compound, benzidine compound, pyrazoline derivative, stilbene derivative Compounds, amine derivatives, oxazolone derivatives, benzothiazole derivatives, benzimidazole derivatives, quinazoline derivatives,
Examples include benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilbene derivatives, poly-N-vinylcarbazole, poly-1-vinylpyrene, poly-9-vinylanthracene, etc.These charge transport materials (CTM) are usually formed with a binder to form a layer. Is done.

Of these, particularly preferred charge transport materials (C
Examples of TM) include compounds represented by the following general formula.

[0074]

[Chemical 7]

(In the formula, Ar ₁ , Ar ₂ , and Ar ₄ each represent a substituted or unsubstituted aromatic hydrocarbon group or a heterocyclic group, and Ar ₃ represents a substituted or unsubstituted divalent aromatic hydrocarbon group. Group or heterocyclic group, R ₂ represents a hydrogen atom or a substituted or unsubstituted aromatic hydrocarbon group or heterocyclic group, n is 1 or 2. Ar ₄ and R ₂ are bonded to each other to form a ring. It may be formed.)

[0076]

Embedded image

(In the formula, R ₃ and R ₄ each represent a substituted or unsubstituted aromatic hydrocarbon group, heterocyclic group or alkyl group, which may be linked to each other to form a ring. R ₅ is hydrogen. An atom or a substituted or unsubstituted aromatic hydrocarbon group, a heterocyclic group or an alkyl group is represented, Ar ₅ is a substituted or unsubstituted aromatic hydrocarbon group or a heterocyclic group, and m is 0 or 1.
Is. )

[0078]

[Chemical 9]

(In the formula, Y is a monovalent substituted or unsubstituted phenyl group, naphthyl group, pyrenyl group, fluorenyl group,
It represents a carbazolyl group, a diphenyl group and a 4,4'-alkylidene diphenyl group, and Ar ₆ and Ar ₇ each represent a substituted or unsubstituted aromatic hydrocarbon group or a heterocyclic group. l represents an integer of 1 to 3. )

[0080]

[Chemical 10]

(In the formula, Ar ₈ , Ar ₉ , Ar ₁₀ and Ar ₁₁ each represent a substituted or unsubstituted aromatic hydrocarbon group or heterocyclic group,
Ar ₁ , Ar ₂ and Ar ₃ are as described above. Among these, specific compound examples preferably used in the photoconductor of the present invention are illustrated below.

[0082]

[Chemical 11]

[0083]

[Chemical 12]

[0084]

[Chemical 13]

[0085]

Embedded image

[0086]

[Chemical 15]

[0087]

Embedded image

As the binder resin contained in the photosensitive layer 6 having the single-layer structure and the charge-generating layer (CGL) and the charge-transporting layer (CTL) in the case of the laminated structure, polyester resin, polystyrene resin, methacrylic resin, acrylic resin are used. , Polyvinyl chloride resin, polyvinylidene chloride resin, polycarbonate resin, polyvinyl butyral resin, polyvinyl acetate resin, styrene-butadiene resin, vinylidene chloride-acrylonitrile copolymer resin, vinyl chloride-maleic anhydride copolymer resin, urethane resin, Silicon resin Epoxy resin, silicon-alkyd resin, phenol resin, polysilane resin, polyvinyl carbazole and the like can be mentioned.

The binder resin contained in the uppermost layer of each of the photoreceptors shown in FIGS. 1 (a) to 1 (f) is preferably resistant to mechanical shock and has high abrasion resistance, and has excellent electrophotographic performance. Those that do not interfere are better. Preferred binder resins include polycarbonate resins having a structural unit represented by the following general formula (I), (II), (III) or (IV).

[0090]

[Chemical 17]

(In the formula, R _{1 to} R ₈ are hydrogen atoms, halogen atoms, substituted or unsubstituted alkyl groups having 1 to 10 carbon atoms, cycloalkyl groups or aryl groups, j is an integer of 4 to 11, and R is ₉ is an alkyl group or an aryl group having 1 to 9 carbon atoms.)

[0092]

Embedded image

(In the formula, R ₁₁ to R ₁₈ each independently represent a hydrogen atom, a halogen atom, an alkyl group or an aryl group.)

[0094]

[Chemical 19]

(In the formula, R _{21 to} R ₂₈ each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted C 1-10 alkyl group, a cycloalkyl group, or an aryl group.)

[0096]

Embedded image

(In the formula, R _{31 to} R ₄₆ each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or an aryl group, and k and m are positive integers, and k / m Is selected to be 1 to 10.) The polycarbonate resin having the structural unit represented by the general formula is preferably one having a weight average molecular weight of 30,000 or more.

Next, as a solvent or a dispersion medium used in forming each of the above layers, n-butylamine, diethylamine, ethylenediamine, isopropanolamine, triethanolamine, triethylenediamine, N, N-dimethylformamide, acetone, methylethylketone , Methyl isopropyl ketone, cyclohexanone, benzene, toluene, xylene, chloroform, dichloromethane, 1,2-dichloroethane, 1,2-dichloropropane, 1,1,
Examples thereof include 2-trichloroethane, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethane, tetrahydrofuran, dioxane, methanol, ethanol, isopropinal, ethyl acetate, butyl acetate, dimethyl sulfoxide, and methyl cellosolve. The present invention is not limited to these, but when a ketone solvent is used, the sensitivity and potential change during repeated use are further improved. Further, these solvents may be used alone or as a mixed solvent of two or more kinds.

In the present invention, the weight ratio of the charge generating substance to the binder resin in the charge generating layer is 1: 5 to 5: 1, and preferably 1: 2 to 3: 1. The film thickness of the charge generation layer is preferably 5 μm or less, and particularly preferably 0.05 to 2 μm.

Further, the charge-transporting material of the charge-transporting layer and the binder resin are dissolved in a suitable solvent, and the solution is applied and dried. The mixing ratio of the charge transport material and the binder resin is preferably 3: 1 to 1: 3 by weight, and particularly preferably 2: 1 to 1: 2.

The thickness of the charge transport layer is preferably 5 to 50 μm, particularly 10 to 40 μm.

When the photoreceptor is a single layer type, it can be obtained by coating and drying a solution in which the above-mentioned charge generating substance and charge transporting substance are dispersed and dissolved in a binder resin.

When the outermost surface of the present invention is formed of a protective layer,
The protective layer is formed by dissolving and dispersing the resin and the silica particles of the present invention together with a solvent and coating the solution on the photosensitive layer. In this case, it is preferable to add a charge transport material (CTM) to the protective layer. The ratio of resin to CTM in the protective layer is preferably 3: 1 to 1: 3. In particular, the thickness of the 2: 1 to 1: 2 protective layer is preferably 0.2 to 10 μm. If it is less than 0.2 μm, it is difficult to obtain the effect of the present invention. On the other hand, if it exceeds 10 μm, the resolution of the image deteriorates due to light scattering by the silica particles in the protective layer. Further, the sensitivity may decrease and the residual potential may increase.
A particularly preferred range is 0.4 to 5 μm.

Next, as the electroconductive support of the electrophotographic photosensitive member of the present invention, 1) a metal plate such as an aluminum plate or a stainless plate, 2) a support such as paper or a plastic film, and aluminum, palladium or gold 3) A thin metal layer such as is provided by lamination or vapor deposition, 3) A layer of a conductive compound such as a conductive polymer, indium oxide or tin oxide is provided by coating or vapor deposition on a support such as paper or plastic film The thing etc. are mentioned.

Next, as a coating processing method for producing the electrophotographic photosensitive member of the present invention, dip coating, spray coating,
Although coating processing methods such as circular amount control type coating are used, the coating process on the surface layer side of the photosensitive layer does not dissolve the lower layer film as much as possible, and spray coating or circular amount control type coating to achieve uniform coating process. It is preferable to use a coating processing method such as. The spray coating is described in, for example, JP-A-3-90.
No. 250 and JP-A-3-269238, the details of the circular amount control type coating are described in, for example, JP-A-58-189061.

According to the spray coating and the circular amount regulation coating, compared with the dip coating or the like, there is less wasteful consumption of the coating liquid, the lower layer is not dissolved and damaged, and uniform coating is achieved. And so on.

In the present invention, an undercoat layer having both a barrier function and an adhesive resin may be provided between the photosensitive layers of the conductive support.

Materials for the undercoat layer include casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, polyvinyl butyral, phenol resin polyamides (nylon 6, nylon 66, nylon 61).
0, copolymerized nylon, alkoxymethylated nylon, etc.), polyurethane, gelatin, aluminum oxide and the like. The thickness of the undercoat layer is preferably 0.1 to 10 μm, particularly preferably 0.1 to 5 μm.

In the present invention, further, a coating is provided between the support and the undercoat layer for compensating for surface defects of the support, and interference fringes which become a problem particularly when the image input is laser light. It is possible to provide a conductive layer for the purpose of preventing the occurrence of This conductive layer is carbon black,
It can be formed by coating and drying a solution in which a conductive powder such as metal particles or metal oxide particles is dispersed in a suitable binder resin. The thickness of the conductive layer is preferably 5 to 40 μm, and particularly preferably 10 to 30 μm.

The shape of the support may be drum-shaped, sheet-shaped, or belt-shaped, and it is preferable that the shape is optimal for the electrophotographic apparatus to which it is applied.

The image holding member of the present invention can be applied to general electrophotographic apparatuses such as copying machines, laser printers, LED printers and liquid crystal shutter printers.
Further, it can be widely applied to devices such as displays, recording, light printing, plate making, and facsimiles to which electrophotographic technology is applied.

FIG. 2 shows a schematic structural example of an image forming apparatus having the electrophotographic photosensitive member of the present invention.

In FIG. 2, reference numeral 10 designates a photosensitive drum which is an image bearing member, and is coated with an OPC photosensitive layer on the drum, grounded, and driven and rotated clockwise. Reference numeral 12 denotes a scorotron charger, which applies uniform charging to the peripheral surface of the photosensitive drum 10 by corona discharge. Prior to the charging by the charging device 12, the peripheral surface of the photoconductor may be erased by performing exposure by 11 using a light emitting diode or the like in order to eliminate the history of the photoconductor in the previous image formation.

After uniformly charging the photoreceptor, the image exposing means 13 performs image exposure based on the image signal. The image exposure means 13 in this figure bends the optical path by a reflection mirror 132 via a polygon mirror 131, an f.theta. Lens, etc., which rotate using a laser diode (not shown) as a light source, and scans the photosensitive drum to form an electrostatic latent image. To be done.

The electrostatic latent image is then developed by the developing device 14. At the periphery of the photosensitive drum 10, there are provided developing devices 14 each containing a developer composed of toner such as yellow (Y), magenta (M), cyan (C), and black (K), and a carrier. The development of the first color is carried out by the developing sleeve 141 which contains a magnet and holds the developer and rotates. The developer is a carrier in which ferrite is used as a core and an insulating resin is coated around the core, a polyester is used as a main material, a pigment corresponding to a color, a charge control agent, silica,
It is composed of toner added with titanium oxide, etc., and the developer is 100-600 μm on the developing sleeve 141 by the layer forming means.
The layer thickness is regulated by the layer thickness and the sheet is conveyed to the developing area and development is performed. At this time, normally, a DC or AC bias potential is applied between the photosensitive drum 10 and the developing sleeve 141 to perform development.

In color image formation, after the visualization of the first color is completed, the second color image forming process is carried out, and the scorotron charger 12 performs uniform charging again to form a latent image of the second color. It is formed by the exposure means 13. An image forming process similar to that for the second color is performed for the third and fourth colors, and a visible image of four colors is formed on the peripheral surface of the photosensitive drum 10.

On the other hand, in the monochrome electrophotographic apparatus, the developing unit 14
Is composed of one kind of black toner, and an image can be formed by one development.

After the image formation, the recording paper P is fed to the transfer area by the rotation operation of the paper feed roller 17 when the transfer timing is adjusted.

In the transfer area, the transfer roller 18 is pressed against the peripheral surface of the photosensitive drum 10 in synchronization with the transfer timing,
The supplied recording paper P is sandwiched and the multicolor image is transferred at once.

Then, the recording paper P is discharged at almost the same time by the separating brush 19 which is brought into a pressure contact state, separated by the peripheral surface of the photosensitive drum 10 and conveyed to the fixing device 20, and the heat roller 201
The toner is fused by heating and pressurizing the pressure roller 202, and then the toner is ejected to the outside of the apparatus through the paper ejection roller 21. The transfer roller 18 and the separation brush 19 are withdrawn from the peripheral surface of the photosensitive drum 10 after the recording paper P has passed and are ready for the next toner image formation.

On the other hand, the photosensitive drum after the recording paper P is separated
Reference numeral 10 denotes a cleaning device 22 in which a blade 221 is pressed to remove and clean residual toner.
After receiving the electric charge from 12, the next image forming process starts. When superimposing a color image on the photoconductor, the blade 221 moves immediately after cleaning the photoconductor surface and retracts from the peripheral surface of the photoconductor drum 10.

Reference numeral 30 is a removable cartridge in which the image holding member, the charging means, the developing means and the cleaning means are integrated.

The electrophotographic apparatus is constructed by integrally combining a plurality of components such as the above-mentioned photosensitive member, developing means, cleaning means and the like as an apparatus unit, and this unit can be detachably attached to the apparatus main body. It may be configured to.
For example, a unit is formed by integrally supporting at least one of a charging unit, a developing unit, and a cleaning unit together with a photoconductor to form a unit, which is detachably attached to the apparatus body, and is attached and detached by using a guide unit such as a rail of the apparatus body. It may be configured freely. At this time, the above device unit may be provided with a charging unit and / or a developing unit.

When the electrophotographic apparatus is used as a copying machine or a printer, the image exposure means irradiates the photoconductor with reflected light or transmitted light from the original, or a sensor reads the original to convert it into a signal. According to the method, the laser beam is scanned, the LED array is driven, or the liquid crystal shutter array is driven to irradiate the photoconductor with light.

When used as a printer for a facsimile, the image exposure means 13 provides exposure for printing received data.

[0126]

The present invention will be described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto.

Production Example 1 of Silica Particles According to the method of Example 1 of JP-A-5-193908,
LPG is supplied as a combustible gas at a flow rate of 3.5 (N · m ³ / h), and oxygen is supplied as an initial combustion supporting gas at a flow rate of 10.0 (N · m ³ / h),
Furthermore, 7 pieces of metal silicon having an average particle size of 20 μm dispersed in a carrier gas consisting of air at a rate of 35 (kg / h) are used.
The silica powder was obtained by supplying at a flow rate of (N · m ³ / h).
At this time, the flow rate of the primary to tertiary combustion-supporting gas is 2
It was set to 0, 30, 40 (N · m ³ / h). The obtained silica powder had an average particle size of 0.5 μm and a sphericity (long axis / short axis ratio) of 1.0. When the differential scanning calorimetry analysis of the obtained silica powder was performed, an endothermic peak was observed in the region of 40 to 200 ° C., and this is designated as sample A1.

Differential Scanning Calorimetry Measurements Differential scanning calorimetry (DSC) is a method in which the energy required to cancel the temperature difference between a thermally stable standard substance and a sample heated at a constant rate is added. , DSC
Since the peak area of is proportional to the amount of heat absorption, it can be quantified according to the following equation.

MΔH = KA Here, M is the mass of the sample, ΔH is the amount of change in energy per unit mass of the sample, K is the device constant, and A is the peak area. The silica powder was left to stand in an environment of 80% relative humidity for 24 hours to control the humidity. After that, the sample was stored in a sealed container under the same conditions until the DSC measurement, and the measurement was performed within 60 minutes after the completion of the humidity control.

The measurement conditions of DSC in this example are shown below.

Device: Differential running calorimeter DSC-20 Thermal controller SSC-580 (Seiko Denshi Kogyo) Measuring conditions: Measuring temperature 35-300 ° C Temperature rising rate 10 ° C / min (relative humidity 80%) Measuring environment Air Still atmosphere Production Example 2 of Silica Particles In Production Example 1, silica particles of A2 to A4 were obtained by changing the concentration dispersed in the carrier gas for adjusting the particle size. The average particle size of these particles is shown in Table 1. The sphericity was 1.0 in all cases.

[0132]

[Table 1]

Example 1 <Preparation of Photoreceptor 1> An intermediate layer made of polyamide resin and having a thickness of 0.3 μm was provided on an aluminum drum having a diameter of 80 mm.
Next, 30 parts by weight of CGM-1 represented by the following structural formula, butyral resin "ESREC B (BX-L)" (manufactured by Sekisui Chemical Co., Ltd.) 10
A coating solution consisting of 1 part by weight of methyl ethyl ketone and 1600 parts by weight of methyl ethyl ketone was applied onto the intermediate layer by dip coating to form a charge generation layer (CGL) having a thickness of 0.3 μm after drying.

Next, a coating solution prepared by dissolving 500 parts by weight of the exemplified compound (T-1) as a charge transporting material (CTM) and 600 parts by weight of a polycarbonate resin "UPILON Z300" (manufactured by Mitsubishi Gas Chemical Co., Inc.) in 3000 parts by weight of dichloromethane. Was applied onto the charge generation layer (CGL) by dip coating to form a charge transport layer (CTL) having a thickness of 25 μm after drying. Further, the exemplified compound (T-1) 5
0 parts by weight and polycarbonate resin "Iupilon Z800"
(Mitsubishi Gas Chemical Co., Ltd.) 100 parts by weight of dichloroethane 2000
Further, the silica particles Al 5 shown in Table 1 were added to the solution dissolved in 1 part by weight.
A coating solution prepared by mixing and dispersing 0 parts by weight of the charge transport layer (CT
A protective layer having a film thickness of 1 μm after drying was formed by applying the coating liquid on L) with a circular amount control type coating machine to obtain a photoconductor 1 for Example 1.

[0135]

[Chemical 21]

<Photoreceptors 2-4 and Comparative Receptors 1-6
Preparation of> The silica particles in the protective layer were replaced with A2, A3, A4 (in the present invention) and A5, A instead of the silica particles A1 in Table 1.
6, A7, A8, A9 (outside of the present invention), respectively, in the same manner as the photoconductor 1, except that photoconductors 2, 3, 4 for the examples and photoconductors 1, 2, 3, 4, 5 for the comparative examples Was produced. Also,
A comparative photoreceptor 6 containing no silica particles was prepared.

The twelve kinds of electrophotographic photosensitive members obtained as described above were mounted on a Konica U-BIX 4145 (manufactured by Konica Corp.) having a charging, exposing, developing, transferring and cleaning process, and a high temperature, A durability test was performed 50,000 times to repeatedly produce an image under high humidity (30 ° C, 80% RH), the amount of wear on the photoconductor film thickness was measured, and the presence or absence of image defects due to reversal of the cleaning blade or cleaning failure was evaluated.

<Electrostatic Characteristic Test> A developing machine of the copying machine was removed, and a remodeling machine having a surface electrometer installed at that position was used. The black paper potential (Vb), the white paper potential (Vw), and the residual potential (Vr) were measured at the first and 50,000th times by repeating each time, and the results are shown in Table 1.

The black paper potential is the surface potential of the photosensitive member when image exposure is performed using a black paper document having a reflection density of 1.3, and the white paper potential is image exposure using a white paper document having a reflection density of 0.0. It is the surface potential of the photoconductor when it is carried out. The residual potential is the potential before recharging after removing the charge after cleaning.

<Evaluation of Image> The above 12 kinds of photoconductors are sequentially mounted on the copying machine, and an original having halftone is used to obtain 50,000.
Images were drawn once. During this period, the presence or absence of background fog due to poor cleaning and the presence or absence of image scratches due to blade cleaning reversal were evaluated.

<Amount of Depletion of Film Thickness> Ten uniform film thickness portions of the photoconductor are measured at random, and the average value is taken as the film thickness of the photoconductor. Film thickness meter EDDY 560C (HELMUT FISCHER GMBHT CO
(Manufactured by the company) is used to measure the film thickness after the first and 50,000 copies,
The difference was defined as the amount of film thickness loss.

[0142]

[Table 2]

As described above, the photoreceptor of the present invention is subjected to repeated electrostatic characteristics, image evaluation, and evaluation even under high temperature and high humidity environment.
It also has excellent performance in terms of film thickness wear resistance.

On the other hand, in the photoconductor of the comparative example, defective cleaning occurs in comparative example 1 and image scratches occur in comparative example 2 in which the amount of film thickness loss is large, and silica particles having a large ΔH of A7, 8, 9 are used. In the photoconductor, the electrostatic characteristics are deteriorated due to repetition under high temperature and high humidity, and fog is generated.

Example 2 Preparation of Photoreceptors 5-8 for Examples and Photoreceptors 7-12 for Comparative Examples The silica particles A1 to A9 shown in Table 1 were subjected to a hydrophobic treatment. Was used (this silica particles after the hydrophobic treatment and A10～A18) theoretical amount of trimethylsilyl as a silane coupling agent in the hydrophobic treatment _{(CH 3) 3 Si (OCH} 3).

However, the logical amount is the amount necessary to form a monomolecular layer on the surface of the particles, and was calculated according to the above formula "Equation 1".

Silica particles A1 to A4 in the protective layer of the photoconductors 1 to 4 obtained by subjecting them to a hydrophobic treatment.
Photoreceptors 5, 6, 7 and 8 for the examples were produced in the same manner except that 10 to A13 were used.

Further, the silica particles A5 to A9 in the protective layers of the proportional photoreceptors 1 to 6 are hydrophobized to obtain silica particles A.
14 to A18 in the same manner except that the photoconductor for comparative example 7 to
11 was produced.

Similar to the photoreceptor of [Example 1], these photoreceptors were subjected to the above-mentioned Konica U-BIX 4145 (Konica Corporation) under a high temperature and high humidity environment of 30 ° C. and 80% RH (relative humidity). The same evaluation as in [Example 1] was performed.

[0150]

[Table 3]

From the above results, when the silica particles subjected to the hydrophobization treatment were used, the silica particles of the present invention were subjected to repeated image evaluation under high temperature and high humidity conditions of 30 ° C. and 80% RH. The electrical characteristics are further improved, the cleaning blade is not turned over, and cleaning failure is not caused. Contrary to this, in Comparative Example 8, image scratches due to blade flipping occurred, in Comparative Example 7, ground fog caused by poor cleaning, and in Comparative Examples 9 to 11, sensitivity decreased and fog caused by increased residual charge.

[Example 3] <Production of Photoreceptors 9, 10, 11 for Examples> Photoreceptor 1 for Examples
Change the aluminum drum diameter of 80mm to 100mm in diameter
CGM-1 of CGM (charge generation material) in GL (charge generation layer)
In the X-ray diffractogram using CuKα characteristic X-ray, the black angle (2θ ± 0.2 ° C) has the maximum peak at 27.3 °, and other 9.5 °, 9.7 °, 11.6 °, 15.0 °, 24.1 °, etc. Also, using oxytitanium phthalocyanine (CGM-2) having at least one or more peaks, the silica particles in the protective layer were changed from A1 to A10, and the protective layer thickness was 0.5, 1.0, 5.0 μm.
Except for the above, the photoconductors 9, 10 and 11 for Examples were manufactured under the same conditions.

The photoconductors 9 to 11 for the above-mentioned examples were charged, exposed, in which a photoconductor drum, a strip electrode, an AC removing electrode, a cleaning blade, a collecting roller, and a PCL (pre-charging removing electrode) were integrally unitized. Color printer LP-7010 (manufactured by Konica Corp.) having developing, transferring and cleaning steps
Image durability test of 100,000 prints was carried out. To evaluate the results, the amount of change in solid white potential VH after 100,000 prints ΔVH (difference between 1st print and 100,000 prints) and the amount of change in solid black potential VL ΔVL (after 1st print and 100,000 prints) The difference) was measured. Furthermore, the presence or absence of reversal of the cleaning blade and the occurrence of cleaning failure were evaluated until 100,000 prints were completed.

[0154]

[Chemical formula 22]

<Preparation of Photoreceptors 13, 14, 15 for Comparative Examples> Photoreceptors 13, 14, 15 for Comparative Examples were prepared in the same manner except that the protective layer silica particles of Examples 9, 10, 11 were A16. It was produced and evaluated simultaneously with the photoconductors 9, 10 and 11 for the examples.

[0156]

[Table 4]

From the above results, those in the present invention are good in that the variation in electrostatic characteristics is small. On the other hand, in Comparative Examples 13 to 15, the electrostatic characteristics are greatly deteriorated.

Example 4 Production of Photoreceptor 12 for Example and Photoreceptor 19 for Comparative Example> Except that 200 parts by weight of silica particles A10 were added to the CTL layer in Example photoreceptor 1. The intermediate layer, the CGL layer and the CTL layer were formed on the aluminum drum as in 1.

However, no protective layer was applied on the CTL layer. In this way, the photoconductor 12 for the example was manufactured. A comparative photoreceptor 16 was prepared in the same manner except that the silica particles A9 were not added to the inner CTL layer.

These were mounted on Konica U-BIX 4145 and evaluated in the same manner as in Example 1.

[0161]

[Table 5]

As described above, the example is superior to the comparative example 16 in that the blade is not turned over and the film thickness is reduced.

[0163]

INDUSTRIAL APPLICABILITY According to the present invention, the surface of the photosensitive layer is not worn or damaged during repeated image formation and has high durability, and the electrophotographic performance is not deteriorated in a high temperature and high humidity environment such as silica particles for a long time. It is possible to provide an electrophotographic photosensitive member which can stably obtain a high density and clear image over a wide range.

Further, by using together with the photoconductor of the present invention, an elastic cleaning blade which is used as a cleaning means in contact with the photoconductor under specific conditions, abrasion of the photoconductive layer during repeated image formation, It is possible to provide an electrophotographic apparatus which is free from damage and has high durability, and which can stably obtain a high density and clear image from beginning to end.

Furthermore, since the incorporated photoreceptor has high durability, it is possible to repeatedly and stably form an image without replacing the photoreceptor, and if the image forming means other than the photoreceptor has a defect. It is possible to provide an apparatus unit that can be replaced promptly and easily even if the above occurs, and that can stably obtain a high-quality image for a long period of time.

[Brief description of drawings]

FIG. 1 is a sectional view showing a layer structure of a photoreceptor according to the present invention.

FIG. 2 is a sectional view of an image forming apparatus according to the present invention.

[Explanation of symbols]

 1 Conductive Support 2 Intermediate Layer 3 Charge Transport Layer (CTL) 4 Charge Generation Layer (CGL) 5 Protective Layer 6 Photosensitive Layer

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yoshihiko Eto, Konica stock company, 2970 Ishikawa-cho, Hachioji, Tokyo (72) Inventor Yoshiaki Takei, 2970 Ishikawa-cho, Hachioji, Tokyo Konica stock, company

Claims (9)

[Claims] 1. A relative humidity is formed on the outermost surface layer of an electrophotographic photosensitive member.
Change in endothermic energy in the range of 40 ℃ to 200 ℃ in differential scanning calorimetry when humidity is controlled in 80% environment Δ
H is 0 to 20 Joules / g and volume average particle size is 0.05
An electrophotographic photoreceptor comprising silica particles having a size of not less than μm and not more than 2 μm. 2. The electrophotographic photosensitive member according to claim 1, wherein the silica particles are synthesized by a chemical flame CVD method. 3. The silica particles have an energy change amount ΔH of an endothermic peak of 40 ° C. or higher and 200 ° C. or lower in differential scanning calorimetry in an environment of 80% relative humidity of 0 to 10 Joules / g. The electrophotographic photosensitive member according to claim 1. 4. The electrophotographic photoreceptor according to claim 1, 2 or 3, wherein the silica particles are treated with a silane coupling agent represented by the following general formula. Embedded image (In the formula, R _{1 represents a} halogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, an alkyloxy group, an alkenyloxy group, a cycloalkyloxy group, an aryloxy group, an acyl group or an acyloxy group,
These groups may further have a substituent. R ₂ ~R _4:
It is a halogen atom, an alkyl group or an alkoxy group. ) 5. The differential scanning calorimetric analysis in the differential scanning calorimetric analysis when the humidity is controlled in the outermost surface layer of the electrophotographic photosensitive member having a photosensitive layer provided on a conductive support in an environment of relative humidity of 80%.
The energy change amount ΔH of the heat absorption in the following range is 0 to
A photoreceptor containing silica particles having a volume average particle size of 20 joules / g and 0.05 μm or more and 2 μm or less, latent image forming means for forming an electrostatic latent image on the photoreceptor, and formation on the photoreceptor Developing means for visualizing the electrostatic latent image formed into a toner image, transfer means for transferring the toner image on the photoconductor obtained by visualizing it onto a transfer material, and remaining on the photoconductor after the toner image transfer An electrophotographic apparatus, comprising: a cleaning unit that cleans the toner that is discharged. 6. The electrophotographic apparatus according to claim 5, wherein the cleaning unit is an elastic blade cleaning unit. 7. The cleaning blade of the cleaning means is 5 to 50 in the counter direction with respect to the photosensitive member.
7. The electrophotographic apparatus according to claim 6, wherein the electrophotographic apparatus is cleaned by pressing with a pressing force of (g / cm). 8. The endothermic energy change amount ΔH in the range of 40 ° C. to 200 ° C. in the range of 40 ° C. to 200 ° C. in the outermost surface layer of the photoconductor is 0 to 2 in the differential scanning calorimetric analysis when the humidity is controlled in an environment of 80% relative humidity.
0 joule / g and volume average particle diameter of 0.05 μm or more 2
A photoreceptor containing silica particles of μm or less, charging means for uniformly charging the photoreceptor, developing means for visualizing an electrostatic latent image on the photoreceptor, visualization on the photoreceptor At least one of a transfer unit for transferring the formed toner image onto a transfer material, a charge removing unit for removing charges on the photoconductor after the transfer, and a cleaning unit for cleaning the residual toner on the photoconductor after the transfer are integrated. Device unit that is detachably mounted on the device body. 9. The apparatus unit according to claim 8, wherein an elastic cleaning blade is used as the cleaning means, and at least the cleaning blade and the photoconductor are integrally supported and are detachably attached to the apparatus main body.