JPH08334908A - Electrophotographic photoreceptor, electrophotographic device and device unit - Google Patents

Abstract

PURPOSE: To provide an electrophotographic photoreceptor which is free from the wear and damage of the photoreceptor and has high durability and with which bright images of always high densities are stably obtainable, and an electrophotographic device and device unit using the electrophotographic photoreceptor. CONSTITUTION: This electrophotographic photoreceptor has a photosensitive layer on a conductive base 1. The extreme surface layer 5 of the photoreceptor is the photosensitive layer. The photosensitive layer contains inorg. particles of Mohs hardness of >=5 and thermosetting resin. The volume average mol.wt. of the inorg. particles is 0.05 to 2.0μm. The inorg. particles are silica particles of which heat absorption energy change rate ΔH of a differential thermal analysis at 40 to 200 deg.C when the particles are humidified in environment of relative humidity of 80%, is 0 to 20 Joule/g. The thermosetting resin is formed by crosslinking a phenoxy resin and its deriv. with multifunctional isocyanate.

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 inorganic particles in the outermost photosensitive layer of the photoreceptor, and more particularly to an electrophotographic photoreceptor having excellent durability and sensitivity.

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 during repeated use, abrasion resistance, and moisture resistance, 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 photoconductors (hereinafter simply referred to as organic photoconductors or OPCs) which are excellent and have a high degree of freedom in selection depending on 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 presumed that it is caused by the friction and damage of the surface of the photosensitive layer due to the rubbing of the photosensitive layer, and the decomposition and deterioration of the photosensitive layer in each process such as charging, image exposure and charge removal on the surface of the photosensitive member.

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 each of JP-A-56-117245, JP-A-63-91666 and JP-A-1-05171, silica particles are contained in the outermost surface protective layer of the photoconductor to improve the mechanical strength of the photoconductor surface. It is described that the durability can be improved by increasing the value. Furthermore, JP-A-57-176057 and 61-117558.
JP-A No. 3-155558 or the like discloses that the silica particles are treated with a silane coupling agent or the like to contain hydrophobic silica particles in the outermost surface protective layer of the photoreceptor, and the mechanical strength of the photoreceptor is increased. It is described that a photosensitive body having higher durability can be obtained by increasing the lubrication property and imparting lubricity.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a photoreceptor having improved abrasion resistance and scratch resistance of the photoreceptor without impairing photographic characteristics such as sensitivity of the electrophotographic photoreceptor. .

Even when a cleaning blade used as a cleaning means is used in combination with the photoconductor, the photoconductor is not worn or damaged during repeated image formation and has high durability, high density and clear image from beginning to end. To provide an electrophotographic photosensitive member which can be stably obtained, and an electrophotographic apparatus using the same.

Still another object of the present invention is that since the photoreceptor incorporated therein has high durability, it is possible to repeatedly and stably form an image without exchanging the photoreceptor, so that if the photoreceptor is 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.

[0012]

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

(1) In an electrophotographic photosensitive member having a photosensitive layer on a conductive support, the outermost surface of the photosensitive member is a photosensitive layer, and the photosensitive layer contains inorganic particles having a Mohs hardness of 5 or more and thermosetting property. An electrophotographic photoreceptor containing a resin.

(2) The volume average particle diameter of the inorganic particles is 0.
The electrophotographic photosensitive member according to the above item 1, wherein the electrophotographic photosensitive member has a thickness of 05 to 2.0 μm.

(3) The amount of change in heat absorption energy ΔH in differential thermal analysis at 40 to 200 ° C. when the humidity of the inorganic particles is adjusted to 80% relative humidity is 0 to 20 joules /
3. The electrophotographic photosensitive member described in 1 or 2 above, which is silica particles of g.

(4) The electrophotographic photoconductor according to any one of items 1 to 3, wherein the thermosetting resin is obtained by crosslinking a phenoxy resin and its derivative with a polyfunctional isocyanate.

(5) In an electrophotographic apparatus having an electrophotographic photoreceptor having a photosensitive layer on a conductive support, an electrostatic latent image forming means, a developing hand, a transfer means and a cleaning means,
An electrophotographic apparatus, wherein an outermost surface layer of the photoreceptor is a photosensitive layer, and the photosensitive layer is configured as a layer containing inorganic particles having a Mohs hardness of 5 or more and a thermosetting resin.

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

(7) In an apparatus unit having at least one of an electrophotographic photosensitive member having a photosensitive layer on a conductive support and an image forming means, the outermost surface layer of the photosensitive member is a photosensitive layer, The layer is configured as a layer containing inorganic particles having a Mohs hardness of 5 or more and a thermosetting resin, and the electrophotographic photosensitive member, a charging unit as the image forming unit, a developing unit,
At least one of a transfer means and a cleaning means is integrally supported, and is detachably attached to an apparatus main body.

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 Mohs hardness defined in the present invention is a hardness used in relation to minerals, and if a specific 10 kinds of minerals are sequentially scratched and scratched, the hardness is lower than that of the minerals.

Specific examples of the inorganic particles having a Mohs hardness of 5 or more used in the present invention include alumina, silica, titanium oxide, zirconium oxide and the like, and silica exhibits particularly excellent properties. The addition amount is 0.1 to 100% by weight, and more preferably 1 to 100% by weight with respect to the thermosetting resin described later.
~ 50% by weight is good.

The outermost surface of the photoreceptor of the present invention is a photosensitive layer, and when the electrophotographic photoreceptor of the present invention is manufactured, the charge transporting material (CTM) is contained in the layer constituting the outermost surface. The layer is a charge transport layer (CTL) containing a layer (CTL) or a charge generating substance (CGM). Among them, CTL is preferable.

Further, in the present invention, by using a thermosetting resin as the binder constituting the photosensitive layer, even in the cleaning method using the cleaning blade, the photosensitive member is not worn or damaged and has excellent durability. That is, a clear image can be stably obtained.

Conventionally, a thermoplastic resin is often used as a binder for a photosensitive layer, and a thermoplastic resin has also been used as a protective layer. However, there is a problem in durability in long-term repeated use, and a protective layer is also used. Those using inorganic particles and thermosetting resin have problems in terms of sensitivity and image quality.

In the present invention, the outermost surface layer of the photoreceptor is a photosensitive layer, a thermosetting resin is used, and inorganic particles having a Mohs hardness of 5 or more are used, so that the photoreceptor has high image quality and high durability. Was able to be formed.

The thermosetting resin is, for example, an epoxy resin, a urethane resin, a silicone resin, a melamine resin, an acrylic resin, a polyester resin or the like, or a combination thereof, and particularly preferably urethane obtained by crosslinking a phenoxy resin with an isocyanate. It is a resin.

Since these thermosetting resins have polar groups involved in curing, they have good affinity with inorganic particles, and some of the polar groups on the inorganic particles contribute to the curing reaction. Although conceivable, the adhesiveness between the inorganic particles and the thermosetting resin is strong, and compared with the case of using a normal thermoplastic resin,
It was found that excellent high durability was obtained. Also, rather than simply using inorganic particles and thermosetting resin in the protective layer,
It has been found to have excellent photographic properties.

The inorganic particles having a Mohs hardness of 5 or more according to the present invention preferably have a volume average particle size of 0.05 to 2.0 μm.
Is.

The silica particles preferable as the inorganic particles will be described below.

As the silica particles, silica sol or colloidal silica synthesized by a sol-gel method in a liquid phase, ultrafine silica particles obtained in a gas phase, or the like can be used.

Due to the manufacturing method of silica sol or 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. Photoreceptors using these silicas are apt to adsorb gas molecules, especially water molecules, and have problems with images in high humidity environments and electrical characteristics during repeated use, and particles that are unlikely to adsorb water molecules are desirable. . 40 to 40 when the humidity is adjusted in an environment where the relative humidity is 80%
It is preferable that the amount ΔH of change in heat absorption energy in differential thermal analysis at 200 ° C. be in the range of 0 to 20 Joules / g.

The electrophotographic photoreceptor of the present invention is an organic photoreceptor containing an organic charge generating substance (CGM) and a charge transporting substance (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 (f) show a constitution in which an outermost surface photosensitive layer 5 is further laminated on the photosensitive layers of FIGS. 1 (a), (b), and (c), respectively. Show. Above (a),
Each of (b), (c), (d), (e), and (f) shows a typical constitution of the organic photoreceptor, and the present invention is limited to these layer constitutions. is not. For example, the intermediate layer 2 shown in these figures may be omitted if not necessary.

Among the above-mentioned layer constitutions, it is more preferable to make the outermost photosensitive layer contain a charge transport substance (CTM) to have a so-called CTL two-layer structure. Inclusion of a charge transport material (CTM) in the outermost surface layer 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) include phthalocyanine pigments, polycyclic quinone pigments, azo pigments,
Perylene pigments, indigo pigments, quinacridone pigments, azurenium pigments, squarylium dyes, cyanine dyes, pyrylium dyes, thiopyrylium dyes, xanthene dyes,
Triphenylmethane dye, styryl dye and the like,
These charge generating materials (CGM) may be layered alone or with an appropriate binder resin.

Examples of the charge transport material (CTM) contained in the photosensitive layer 6 include oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives,
Imidazolone derivative, imidazoline derivative, bisimidazolidine derivative, styryl compound, hydrazone compound,
Benzidine compounds, pyrazoline derivatives, stilbene compounds, amine derivatives, oxazolone derivatives, benzothiazole derivatives, benzimidazole derivatives, quinazoline derivatives, benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilbene derivatives, poly-N-vinylcarbazole, poly-1- Vinyl pyrene, poly-9-vinyl anthracene, etc. are mentioned, and these charge transport materials (CT
In M), a layer is formed together with the thermosetting resin of the present invention.

Among these, particularly preferable charge transporting substances (CTM) are compounds represented by the following general formula.

[0040]

Embedded image

(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. Represents a hydrogen atom or a 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. It may form a ring.)

[0042]

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. )

[0044]

Embedded image

(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 or 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. )

[0046]

[Chemical 4]

(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.

[0048]

Embedded image

[0049]

[Chemical 6]

[0050]

[Chemical 7]

[0051]

Embedded image

[0052]

[Chemical 9]

[0053]

[Chemical 10]

As the binder resin contained in the charge generation layer (CGL) and charge transport layer (CTL) other than the outermost layer in the case of the above-mentioned laminated structure, polyester resin, polystyrene resin, methacrylic resin, acrylic resin, polychlorinated resin can be used. Vinyl 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, silicone resin, Epoxy resin, silicone-alkyd resin, phenol resin, polysilane resin, polyvinyl carbazole and the like can be mentioned.

As the solvent or dispersion medium used when forming each of the above layers, n-butylamine, diethylamine,
Ethylenediamine, isopropanolamine, triethanolamine, triethylenediamine, N, N-dimethylformamide, acetone, methylethylketone, methylisopropylketone, cyclohexanone, benzene, toluene, xylene, chloroform, dichloromethane, 1,2-
Dichloroethane, 1,2-dichloropropane, 1,1,2-trichloroethane, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethane, tetrahydrofuran, dioxane, methanol, ethanol, isopropinal,
Examples thereof include ethyl acetate, butyl acetate, dimethyl sulfoxide, methyl cellosolve and the like. 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,
Particularly, 1: 2 to 3: 1 is preferable. The film thickness of the charge generation layer is preferably 5 μm or less, and particularly preferably 0.05 to 2 μm.

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 ratio, 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 photosensitive layer of the present invention is formed, the photosensitive layer is formed by dissolving and dispersing the thermosetting resin of the present invention and inorganic particles together with a solvent and applying the solution on the above-mentioned photosensitive layer. In this case, the ratio of resin to CTM in the layer is 3: 1
˜1: 3 is preferred. Particularly, it is 2: 1 to 1: 2, and the film thickness of the outermost photosensitive 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 is deteriorated due to light scattering by the inorganic particles in the photosensitive layer. Further, the sensitivity may decrease and the residual potential may increase. A particularly preferred range is 0.4 to 5 μm.

The conductive support of the electrophotographic photosensitive member of the present invention is as follows: 1) a metal plate such as an aluminum plate or a stainless plate; 2) aluminum, palladium or gold on a support such as paper or a plastic film. 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, as compared with the dip coating, the coating liquid is not wasted, the lower layer is not dissolved or 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 is preferably a shape suitable 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 type 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 configuration example of an electrophotographic apparatus having the electrophotographic photosensitive member of the present invention.

In FIG. 2, reference numeral 10 denotes a photosensitive drum, which is an image carrier, and is coated with an OPC photosensitive layer, 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 photosensitive member, 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 the color image formation, after the visualization of the first color is completed, the second color image forming process is performed, 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 device 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.

Next, 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.
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
Residual toner is removed / cleaned by the pressure contact of the blade 221 of the cleaning device 22, and the process 10 again receives the charge removal by the exposure charge eliminator 11 and the charge by the charger 12 to start the next image forming process. 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 cartridge in which the image holding member, the charging means, the developing means and the cleaning means are integrated and removable.

The electrophotographic apparatus is constructed by integrally combining a plurality of constituent elements 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 is preferable to configure 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 is a freely configured one. 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 document, or a sensor reads the original document 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.

[0083]

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

Example 1 <Preparation of Photoreceptor 1> A copolymer type polyamide resin “Amilan CM-80” was formed on an aluminum drum having a diameter of 80 mm.
00 "(manufactured by Toray Industries, Inc.) 1.5 parts by weight dissolved in a mixed solvent of 90 parts by volume of methanol and 10 parts by volume of butanol is applied by dip coating to form an intermediate layer having a thickness of 0.3 μm. . Next, polyvinyl butyral resin "ESREC BL-
S "(manufactured by Sekisui Chemical Co., Ltd.) 0.8 parts by weight is dissolved in a mixed solvent of 80 parts by weight of methyl ethyl ketone and 20 parts by weight of cyclohexane, and C represented by the following structural formula is added to the resulting solution.
GM-1 4 parts by weight (CGM / binder amount ratio is 5.
0) is mixed and dispersed to form a charge generation layer (CGL) having a thickness of 0.2 μm after the coating solution is applied onto the intermediate layer by dip coating.
Was formed.

Next, 15 parts by weight of a polycarbonate resin "Iupilon Z300" (manufactured by Mitsubishi Gas Chemical Co., Inc.) as a binder and an exemplary compound (T-
2) 10 parts by weight, hindered phenolic antioxidant "Irganox 1010" (manufactured by Sankyo Chemical Co., Ltd.) 0.25
A coating solution obtained by dissolving 100 parts by weight of methylene chloride in 100 parts by volume of methylene chloride 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.

Then, as a binder, a phenoxy resin "P
KHH "(manufactured by Union Carbide Co.) 1.6 parts by weight, diphenylmethane diisocyanate 0.2 parts by weight as a curing agent, inorganic particles 0.64 parts by weight as shown in Table 1, and an exemplary compound (T-2) 1 part by weight as a charge transport material. A coating solution obtained by dissolving and dispersing 0.025 parts by weight of a hindered phenolic antioxidant "Irganox 1010" (manufactured by Sankyo Chemical Co., Ltd.) in 100 parts by volume of 1,2-dichloroethane is used as the first charge transport layer. A second charge transporting layer having a film thickness after drying of 1 μm was formed by applying the above solution using a circular amount regulating type coating machine to obtain a photoreceptor 1 of the present invention shown in Table 1.

[0087]

[Chemical 11]

<Photoreceptors 2 to 10 and Comparative Example Receptors 1 to 1>
Preparation of 5> Type and volume average particle size of inorganic fine particles of photoreceptor 1, hardness, amount of endothermic energy change ΔH in differential thermal analysis, ratio of inorganic particles to binder resin (% by weight), type of binder, curing agent Type and NCO / OH
Photosensitive members 2 to 10 and comparative photosensitive members 1 to 5 were obtained in the same manner as the photosensitive member 1 except that the ratio was changed as shown in Table 1. still,
Comparative Examples 3 to 5 exclude the charge transport material T-2 of Example 1.

Analog copying having the steps of charging, image exposure, development, transfer, charge removal and cleaning, in which at least the photoreceptor and the cleaning means are unitized as a unit. Machine "Konica U-BIX
4145 "(manufactured by Konica Corp.) and subjected to an image forming test at room temperature and normal humidity (20 ° C, 60% RH). Image evaluation of the obtained image and amount of potential fluctuation, 100,000 times The film thickness of the worn film after copying was measured.

1) Image Evaluation The photoconductors were sequentially mounted on the copying machine, and images were printed 100,000 times using a halftone original. At this time, a scorotron charger was used as the charger, and an image was formed on the photoreceptor under a constant charging condition of -750 V by grid control.

The image forming test was conducted 100,000 times, and the presence or absence of background fog due to poor cleaning, the presence or absence of streak failure due to the cleaning blade being turned over, the image sharpness, etc. were visually observed, and the results are shown in Table 2. It was shown to.

2) Measurement of Potential Fluctuation Amount of black paper potential (Vb) and white paper potential (Vw) before and after the 100,000 times image forming test are measured, and the difference | ΔVb | and | Δ
From Vw |, the amount of potential fluctuation of each photosensitive member before and after image formation is calculated,
The results are shown in Table 2.

As the original for measurement, an original having a solid black area with a reflection density of 1.3 and a solid white area with a reflection density of 0.0 was used, and it was -750 V by the scorotron charger.
After charging, the electrostatic latent image formed by image exposure from the original is measured by an electrometer placed at the position of the developing device to measure the black paper potential (Vb) and the white paper potential (Vw). I did it.

[0094]

[Table 1]

[0095]

[Table 2]

From Table 2, in the examples using the respective photoreceptors of the present invention, there is little potential fluctuation such as black paper potential and white paper potential and film thickness wear in the course of repeated image formation, and clear image without background fog or streak failure. It can be seen that, although a good image can be obtained, in the case where the photoconductor for comparison is used, background fog and streak failure occur in the process of repeated image formation, and the film thickness wear is large, so that a good image cannot be obtained.

[0097]

EFFECTS OF THE INVENTION In the process of repetitive image formation, potential fluctuations such as black paper potential and white paper potential and film thickness loss are small, and background fog is caused.
A clear image without streak failure can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a layer structure of a photoconductor of the present invention.

FIG. 2 is a schematic sectional view of an electrophotographic apparatus used in the present invention.

[Explanation of symbols]

 1 Conductive Support 2 Intermediate Layer 3 Charge Transport Layer 4 Charge Generation Layer 5 Outermost Photosensitive Layer 6 Photosensitive Layer 10 Photosensitive Drum 12 Scorotron Charger 11 Exposure Charger 13 Image Exposure Means 131 Polygon Mirror 132 Reflection Mirror 14Y, 14M, 14C, 14K Developing device 141 Developing sleeve P Recording paper 17 Paper feeding roller 18 Transfer roller 19 Separation brush 20 Fixing device 201 Heat roller 202 Crimping roller 21 Paper discharging roller 22 Cleaning device 221 Blade 30 Cartridge

Claims (7)

[Claims] 1. An electrophotographic photosensitive member having a photosensitive layer on a conductive support, wherein the outermost surface layer of the photosensitive member is a photosensitive layer, and the photosensitive layer contains inorganic particles having a Mohs hardness of 5 or more and thermosetting property. An electrophotographic photoreceptor containing a resin. 2. The volume average particle diameter of the inorganic particles is 0.05.
The electrophotographic photosensitive member according to claim 1, wherein the electrophotographic photosensitive member has a thickness of about 2.0 μm. 3. A silica particle having a thermal absorption energy change amount ΔH of 0 to 20 joules / g in differential thermal analysis at 40 to 200 ° C. when the inorganic particles are conditioned under an environment of 80% relative humidity. Claim 1 or 2 characterized by the above.
The electrophotographic photosensitive member described. 4. The electrophotographic photosensitive member according to claim 1, 2 or 3, wherein the thermosetting resin is obtained by crosslinking a phenoxy resin and its derivative with a polyfunctional isocyanate. 5. An electrophotographic apparatus having an electrophotographic photoreceptor having a photosensitive layer on a conductive support, an electrostatic latent image forming means, a developing hand, a transferring means and a cleaning means, the outermost surface layer of the photoreceptor. Is a photosensitive layer, and the photosensitive layer is configured as a layer containing inorganic particles having a Mohs hardness of 5 or more and a thermosetting resin. 6. The electrophotographic apparatus according to claim 5, wherein the cleaning unit is an elastic blade cleaning unit. 7. In an apparatus unit having at least one of an electrophotographic photosensitive member having a photosensitive layer on a conductive support and an image forming means, the outermost surface layer of the photosensitive member is a photosensitive layer, and the photosensitive layer. Is a layer containing inorganic particles having a Mohs hardness of 5 or more and a thermosetting resin, and the electrophotographic photosensitive member and at least one of a charging unit, a developing unit, a transfer unit and a cleaning unit as the image forming unit are integrally formed. An apparatus unit, which is supported by the apparatus and is detachably attached to the apparatus body.