JPH08339092A - Electrophotographic photoreceptor, electrophotographic device and device unit - Google Patents

Abstract

PURPOSE: To obtain an org. photoreceptor in which deterioration in the electrification performance and wear in the film thickness are hardly caused, good cleaning property can be maintained and the surface is hardly scratched even when the photoreceptor is repeatedly used, and moreover, to provide an electrophotographic device and a device unit having high reliability by using this photoreceptor. CONSTITUTION: The electrophotographic photoreceptor consists of a conductive supporting body and a photosensitive layer. The outermost surface layer of the photoreceptor contains inorg. particles satisfying the following conditions. (1) The volume average particle size is between >=0.1μm and <=2μm. The ratio (DW/DN) of the number average particle size (DN) to the weight average particle size (DW) defined by the following formula satisfies 1<=(DW/DN)<=2. Or, (2) the volume average particle size is between >=0.1μm and <=1.0μm and particles having >1.0μm particle size are included by <=1vol.%. DN and DW are defined as DN=ΣNiDi/ΣNi and DW=ΣmiNiDi/ΣmiNi, wherein mi is the mass of the particle, Ni is the number of particles and Di is the diameter of the particle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member, an electrophotographic apparatus and an apparatus unit applied to a copying machine, a printer and the like.

[0002]

2. Description of the Related Art Conventionally, inorganic photoreceptors such as selenium, cadmium sulfide and zinc oxide have been widely used as photoreceptors used in electrophotographic apparatuses, but recently, conversion to organic photoreceptors has been rapidly progressing. Made

In view of environmental pollution, the inorganic photoconductor has a problem. Recently, electrophotographic apparatuses have been widely used as image forming apparatuses such as color copying machines and laser printers as well as monochrome copying machines. There may be a background such as. Therefore, various performance demands and demands for cost and productivity improvement are extremely high, and in order to meet these demands, organic materials are more advantageous because various materials and combinations thereof are possible.

However, the organic photoreceptor does not necessarily have all the required performances, and there still remains an unsolved problem. The largest of these is surface strength. The surface of the organic photoreceptor is mostly formed of a resin film layer or a photosensitive component or a binder resin with the photosensitive component, but these are soft because they are organic compounds. Therefore, due to the developer brush and cleaning blade that come into contact with the surface of the photoconductor, the film thickness gradually decreases and streaks are formed, and the sensitivity is deteriorated due to deterioration of charging performance, fogging occurs, and streaks appear on the image. It causes troubles such as.

As a countermeasure, a material such as polycarbonate which is relatively strong against abrasion is used as a binder used for the outermost surface layer, and a slippery material such as silicone resin is used, and further, JP-A-60- 57346
As described in JP-A No. 60-57847, there is known a technique of adding silica sol or colloidal silica dispersed in the liquid phase as colloidal silica particles, silica ultrafine particles obtained in a gas phase, etc. to a protective layer or the like. ing.

However, even with these, sufficient effects cannot be obtained, and even better measures have been studied until now.

[0007]

The surface strength of the organic photoconductor is increased, and even if the organic photoconductor is repeatedly used, the charging performance is not deteriorated and the film thickness is less worn, and the cleaning property is good, and the surface of the organic photoconductor is scratched. This is to develop a photoconductor that is hard to stick and has high durability. Furthermore, the development of a highly reliable electrophotographic apparatus and apparatus unit using this photosensitive member.

[0008]

The object of the present invention can be achieved by adopting any of the following constitutions.

(1) The volume average particle size is 0.1 in the outermost surface layer of an electrophotographic photosensitive member comprising a photosensitive layer provided on a conductive support.
The ratio of the number average particle diameter (DN) and the weight average particle diameter (DW) defined by the following formula (DW)
An electrophotographic photoreceptor containing inorganic particles having a W / DN of 1 ≦ (DW / DN) ≦ 2.

DN = ΣNiDi / ΣNi DW = ΣmiNiDi / ΣmiNi (wherein mi is the mass of particles, Ni is the number of particles, and Di is the diameter of the particles.) (2) A photosensitive layer is provided on a conductive support. The outermost surface layer of the electrophotographic photosensitive member provided has a volume average particle diameter of 0.1 μm or more,
An electrophotographic photoreceptor comprising inorganic particles having a particle component of 0 μm or less and 1.0 μm or more of 1.0 vol% or less.

(3) The electrophotographic photosensitive member according to (2), wherein the electrophotographic photosensitive member is an electrophotographic photosensitive member in which a plurality of charge transport layers are laminated on a charge generation layer.

(4) The electrophotographic photosensitive member according to (2) or (3), wherein the particle size of the inorganic particles is adjusted by filtering a dispersion of the inorganic particles with a filter.

(5) The electrophotographic photosensitive member according to any one of (1) to (4), wherein the inorganic particles are sintered at 300 ° C. or higher.

(6) The electrophotographic photosensitive member according to any one of (1) to (5), wherein the inorganic particles are silica particles.

(7) The electrophotographic photosensitive member according to any one of (1) to (6), wherein the silica particles are hydrophobized.

(8) When the inorganic particles are conditioned in an environment of 80% relative humidity, the amount of endothermic energy change ΔH in differential scanning calorimetry in the temperature range of 40 to 300 ° C. is 0.
~ 150 (J / g) (1) ~
The electrophotographic photosensitive member according to any one of (7).

(9) The volume average particle size is 0.1 in the outermost surface layer of the electrophotographic photosensitive member comprising a photosensitive layer provided on a conductive support.
The ratio (DW) of the number average particle diameter (DN) and the weight average particle diameter (DW) defined by the following equation
/ DN) 1 ≦ (DW / DN) ≦ 2, a photoconductor containing inorganic particles, a latent image forming means for forming an electrostatic latent image on the photoconductor, and an electrostatic latent image formed on the photoconductor. Developing means for developing the image into a toner image, transfer means for transferring the toner image on the photoconductor obtained by the visualization onto a transfer material, and cleaning the toner remaining on the photoconductor after the toner image transfer An electrophotographic apparatus comprising a cleaning means.

DN = ΣNiDi / ΣNi DW = ΣmiNiDi / ΣmiNi (In the formula, mi represents the mass of particles, Ni represents the number of particles, and Di represents the diameter of the particles.) (10) A photosensitive layer is formed on a conductive support. The outermost surface layer of the electrophotographic photosensitive member provided has a volume average particle diameter of 0.1 μm or more,
A photoreceptor containing inorganic particles having a particle component of 1.0 μm or less and 1.0% by volume or less of a particle component of 1.0 μm or more,
Latent image forming means for forming an electrostatic latent image on the photoconductor, developing means for visualizing the electrostatic latent image formed on the photoconductor into a toner image, and on the photoconductor obtained by visualizing An electrophotographic apparatus comprising: a transfer unit that transfers the toner image of 1. to a transfer material; and a cleaning unit that cleans the toner remaining on the photoconductor after the toner image is transferred.

(11) The electrophotographic apparatus according to (9) or (10), wherein the inorganic particles contained in the uppermost layer of the photoreceptor are sintered at 300 ° C. or higher.

(12) The electrophotographic apparatus according to (9) or (10), wherein the cleaning means is an elastic blade cleaning means.

(13) The cleaning blade of the cleaning means is brought into pressure contact with the photosensitive member in a counter direction with a pressure contact force of 5 to 50 (g / cm) for cleaning. Electrophotographic device.

(14) The outermost surface layer of an electrophotographic photosensitive member having a photosensitive layer provided on a conductive support has a volume average particle diameter of 0.
1 μm or more and 2 μm or less, the ratio (D) of the number average particle diameter (DN) and the weight average particle diameter (DW) defined by the following equation
W / DN) 1 ≦ (DW / DN) ≦ 2, a photoreceptor containing inorganic particles, charging means for uniformly charging the photoreceptor, and an electrostatic latent image on the photoreceptor visualized. Developing means, a transfer means for transferring the toner image visualized on the photoconductor onto a transfer material, a destaticizing means for removing charges on the photoconductor after the transfer, and a residue on the photoconductor after the transfer At least one of cleaning means for cleaning the toner is integrally supported and is detachably attached to the apparatus main body.

DN = ΣNiDi / ΣNi DW = ΣmiNiDi / ΣmiNi (wherein mi is the mass of particles, Ni is the number of particles, and Di is the diameter of particles) (15) A photosensitive layer is provided on a conductive support. The outermost surface layer of the electrophotographic photosensitive member provided has a volume average particle diameter of 0.1 μm or more,
A photosensitive member containing inorganic particles having a particle component of 1.0 μm or less and 1.0 μm or more of 1.0 volume% or less, a charging unit for uniformly charging the photosensitive member, and the photosensitive member Developing means for visualizing the electrostatic latent image of, the transfer means for transferring the toner image visualized on the photoconductor onto the transfer material, the charge removing means for removing the charge on the photoconductor after the transfer, and the transfer An electrophotographic apparatus unit, wherein at least one of cleaning means for cleaning toner remaining on the photoconductor after that is integrally supported and is detachably attached to the apparatus main body.

(16) 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 (14) or (15).
The described electrophotographic apparatus unit.

(17) The electrophotographic apparatus unit according to (14) or (15), wherein the inorganic particles contained in the uppermost layer of the photoconductor are sintered at 300 ° C. or higher.

Inorganic particles conventionally used in a protective layer or the like for the purpose of improving the surface strength of an electrophotographic photoreceptor are silica sol or colloidal silica dispersed in a colloidal dimension in a liquid phase, or obtained in a gas phase. Ultrafine silica particles and the like are known. However, particles in the colloidal dimension have a particle size smaller than 0.1 μm, and particles in this region cannot provide sufficient surface strength.

On the other hand, even if the average particle size exceeds 0.1 μm, coarse particles and ultrafine particles are mixed in with a certain probability in particles having a wide particle size distribution. Particles having a distribution as sharp as possible are desired because problems such as image defects due to aggregation occur. In particular, removal of coarse particles of 1.0 μm or more gives good results, and a typical method is to filter the dispersion liquid of inorganic particles using a filter that does not pass particles of 1.0 μm or more.

The particles of the present invention are specified so as to satisfy 1 ≦ (DW / DN) ≦ 2. When (DW / DN) is 1, the particles have a uniform particle size, and this value increases as the distribution becomes wider. Grows. Due to the above reason, the value of DW / DN which is larger than the specified value 2 does not exert the effect of the present invention.

The uppermost layer of the electrophotographic photosensitive member of the present invention has a thickness of 0.1 to 40 μm, and the inorganic particles contained in the uppermost layer are preferably hard particles having a Mohs hardness of 4 or more. Will not be adversely affected.

Examples of such inorganic particles include oxides such as cerium oxide, chromium oxide, aluminum oxide, magnesium oxide, silicon oxide, tin oxide, zirconium oxide, iron oxide and titanium oxide; calcium sulfate, barium sulfate and sulfuric acid. Sulfates such as aluminum; silicates such as calcium silicate and magnesium silicate; nitrides such as boron nitride and titanium nitride; silicon carbide, titanium carbide,
Carbides such as boron carbide, tungsten carbide, and zirconium carbide; borides such as zirconium boride and titanium boride, and the like can be given. One of these can be used, or two or more can be used as necessary.

The inorganic particles have a volume average particle diameter of 0.1 μm.
The particle size is 2 μm or less and preferably substantially spherical particles having a major axis / minor axis ratio of less than 2.0.

The volume average particle diameter of the inorganic particles is 0.1 μm.
If it is below the range, sufficient mechanical strength of the photoreceptor surface cannot be obtained,
Further, as a result of the increase in the surface area of the particles, the amount of adsorbed water and the like increases, and the surface of the photoreceptor is worn and damaged during repeated image formation, resulting in deterioration of electrophotographic performance. If it exceeds 2.0 μm, the surface roughness of the photoconductor becomes large and the cleaning blade wears.
If it is damaged, the cleaning characteristics are deteriorated, cleaning failure occurs, and image blurring easily occurs. The inorganic particles being substantially spherical means that the particles magnified 10,000 times with an electron microscope are not indefinite and the ratio of the major axis / minor axis is 2.
It is regarded as a spherical shape of less than 0. In that case, it is possible to reduce the wear coefficient of the surface of the photoconductor, and it is possible to prevent the elastic cleaning blade from being reversed (turned over), which has been a problem in the past.

The number, volume, and weight average particle size of the inorganic particles are all measured by a laser diffraction / scattering particle size distribution measuring device LA-700 (manufactured by Hikiba Seisakusho) as a volume-based value of a sphere equivalent diameter. To be done.

The concrete measurement result is assumed to be 0.04 to
Since it is displayed as a histogram obtained by dividing 262 μm into 64, DW, DN, and DW / DN can be obtained using this histogram.

The inorganic particles are preferably hydrophobized with a hydrophobizing agent such as a titanium coupling agent, a silane coupling agent, a polymeric fatty acid or a metal salt thereof.

Examples of the titanium coupling agent include tetrabutyl titanate, tetraoctyl titanate, isopropyl triisostearoyl titanate, isopropyl tridecylbenzene sulfonyl titanate, bis (dioctyl pyrophosphate) oxyacetate titanate and the like. Further, as the silane coupling agent, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-β- (N-vinylbenzylaminoethyl) γ-aminopropyltrimethoxysilane hydrochloride, hexamethyldisilazane, methyltrimethoxysilane, butyltrimethoxysilane, isobutyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltri Examples thereof include methoxysilane, dodecyltrimethoxysilane, phenyltrimethoxysilane, o-methylphenyltrimethoxysilane, p-methylphenyltrimethoxysilane.

The fatty acids include undecyl acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid,
Long-chain fatty acids such as pentadecanoic acid, stearic acid, heptadecanoic acid, arachidic acid, montanic acid, oleic acid, linoleic acid, and arachidonic acid are mentioned, and their metal salts are zinc, iron, magnesium, aluminum, calcium, sodium, lithium. Salts with metals such as.

These compounds are preferably added in an amount of 1 to 10% by weight with respect to the above-mentioned inorganic particles for coating, preferably 3 to 7% by weight. Further, these materials can be used in combination, and the surface of the inorganic particles is usually covered with a monomolecular layer or a layer close thereto.

In the present invention, silica particles are particularly preferably used as the inorganic particles contained in the uppermost layer of the photoreceptor, and further silica particles having low hygroscopicity and few active hydroxyl groups on the surface are preferably used. .

Such silica particles have an endothermic peak in the range of 40 to 300 ° C. by a differential scanning calorimetry method, and in an environment of RH 80%, the amount of change ΔH in energy of the endothermic peak is 0 to 0. 150 J / g. More preferably, the silica particles are treated with a hydrophobizing agent such as the silane coupling agent so that the energy change amount ΔH is 0 to 20 J / g.

As a method for producing spherical silica, a wet sol-gel method, a dry spraying method and a combustion method are generally known.

The sol-gel method can be obtained by introducing alkoxysilane as a raw material little by little into alcohol and pure water and hydrolyzing it. At this time, by keeping the solution alkaline or dispersing it with a surfactant, the polycondensed silica becomes spherical particles without gelation or secondary association. This method can relatively easily produce monodispersed silica having a uniform particle size. As commercially available products, high-presica (Ube Nitto Kasei) and sea hosta (Nippon Shokubai) are known.

The polymerized silica that can be obtained by such a granulation polymerization method is porous and has a large internal surface area, so that water adsorption may occur. Sintering is effective for reducing the internal surface area and polar groups on the particle surface. The temperature range of the treatment is 300 ° C. or higher, and if it is lower than this temperature, the intended effect cannot be obtained. It should be noted that the treatment at 300 ° C. or higher as the sintering treatment is also effective for those produced by other methods.

In the spraying method, crystalline silica powder is used for melting in oxygen and hydrogen or in an LPG flame. The characteristic of this method is that
The fine particles are welded and disappear, and the particle size distribution is biased toward the coarse particles,
To be sharp.

In the combustion method, silicon tetrachloride or high-purity silicon powder is used to burn oxygen and hydrogen in an LPG flame. In this method, silica having various particle sizes can be obtained by controlling the amount of feed gas and the feed rate.

In a preferred embodiment of the electrophotographic apparatus of the present invention, the elastic blade of the elastic blade cleaning means is pressed against the electrophotographic photosensitive member incorporated in the apparatus at a pressure of 5 to 50 g / cm in the counter direction. Used by pressure contact.

In a preferred embodiment of the apparatus unit of the present invention, the cleaning means is an elastic blade cleaning means, and at least the cleaning means and the electrophotographic photosensitive member are integrally supported in the apparatus unit, and the apparatus main body is provided. It is detachably attached to.

The photosensitive layer of the electrophotographic photosensitive member of the present invention in which the inorganic particles are contained in the outermost surface layer may be an inorganic photosensitive member using selenium, amorphous silicon, cadmium sulfide or the like, 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.

In FIG. 1A, the intermediate layer 2 is formed on the conductive support 1.
Through the charge generation material (CGM) and charge transport material (CT
M) is a photoreceptor having a single-layered photosensitive layer 6, and FIG. 1B contains a charge transport material (CTM) as a main component on an electrically conductive support 1 through an intermediate layer 2. And a charge generation layer (CGL) 4 containing a charge generation material (CGM) as a main component in this order.
(C) is a photoconductor having a photoconductive layer 6 formed by laminating a charge generation layer (CGL) 4 and a charge transport layer (CTL) 3 in this order on an electroconductive support 1 with an intermediate layer interposed therebetween.

Further, FIGS. 1 (d), (e), and (v) show the protective layer 5 on the photosensitive layer in 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.

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

The protective layer, when provided, is composed of at least a resin and the inorganic particles of the present invention. However, the protective layer contains a charge transporting substance (CTM), and a so-called plurality of charge transporting layers are laminated. An electrophotographic photoreceptor is more preferred.
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 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 and the like can be mentioned. These charge transport materials (CTM) are usually layered with a binder.

Among these, particularly preferable charge transport materials (CTM) are the following compounds.

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[0057]

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[0058]

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[0059]

[Chemical 4]

[0060]

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[0061]

[Chemical 6]

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, polyvinyl chloride resin, polyvinylidene chloride resin, polycarbonate resin, polyvinyl butyral resin, polyvinyl acetate resin, styrene-butadiene resin, vinylidene chloride-acrylonitrile copolymer resin, vinyl chloride-
Examples thereof include maleic anhydride copolymer resin, urethane resin, silicone resin epoxy resin, silicone-alkyd resin, phenol resin, polysilane resin, and polyvinylcarbazole.

Next, as the solvent or dispersion medium used when forming each of the layers, those mentioned as the solvent or dispersion medium of the polycarbonate resin are preferably used. When a ketone solvent is used, the sensitivity and potential change during repeated use are further improved. Further, these solvents can 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, especially 1: 2 to 3: 1 are preferred. The thickness of the charge generation layer is preferably 2 μm or less, particularly 0.05 to 2 μm.
m is preferred.

The charge-transporting layer is formed by dissolving the charge-transporting substance and the binder resin in a suitable solvent and coating and drying the solution. The mixing ratio of the charge transport material and the binder resin is preferably 3: 1 to 1: 3 by weight,
Particularly, 2: 1 to 1: 2 are preferable.

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

The photosensitive layer of the present invention is prepared by coating and drying a predetermined layer as described above. The amount of residual solvent after drying is preferably 2% or less of the photosensitive layer, more preferably 1.5.
% Or less. To obtain a residual solvent amount within this range, a drying temperature of 90 to 120 ° C., preferably 95 to 120 ° C. is preferable, and such a residual solvent amount improves the repeating characteristics.

Next, as a conductive support for 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,
A thin metal layer such as aluminum, palladium or gold provided by lamination or vapor deposition, 3) on a support such as paper or plastic film,
Examples thereof include those in which a layer of a conductive compound such as a conductive polymer, indium oxide or tin oxide is provided by coating or vapor deposition.

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. Regarding the spray coating, for example, JP-A-3-90
250 and JP-A-3-269238, the details of the circular amount control type coating are described in, for example, JP-A-58.
It is described in detail in JP-A-189061.

According to the spray coating and the circular amount regulation coating, as compared with the dip coating or the like, there is no wasteful consumption of the coating liquid, the lower layer is not dissolved or damaged, and uniform coating is achieved. And so on.

In the present invention, as described above, an intermediate layer having a barrier function and a binder resin may be provided between the conductive support and the photosensitive layer.

Materials for the intermediate layer include casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, polyvinyl butyral, phenol resin polyamides (nylon 6, nylon 66, nylon 610, copolymer nylon, alkoxymethyl). Nylon, etc.), polyurethane, gelatin, aluminum oxide and the like. The thickness of the intermediate layer is preferably 0.1 to 10 μm, and particularly preferably 0.1 to 5 μm.

In the present invention, a coating for compensating for surface defects of the support is provided between the support and the intermediate layer, and interference fringes which become a problem especially when the image input is laser light are used. A conductive layer may be provided for the purpose of preventing the generation. 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, particularly preferably 10 to 30 μm.

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

The present invention is a copier, laser printer,
It is generally applicable to electrophotographic devices such as LED printers and liquid crystal shutter printers, but is also widely applicable to devices such as displays, recording, light printing, plate making, and facsimiles to which electrophotographic technology is applied. is there.

FIG. 2 shows a schematic structural example (cross-sectional view) 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. A photosensitive layer is coated on the drum, grounded and driven and rotated clockwise. Reference numeral 12 denotes a scorotron charger, which applies a uniform charge to the peripheral surface of the photosensitive drum 10 by corona discharge. Prior to the charging by the charger 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.

Image exposure means 13 after uniform charging of the photoreceptor
Thus, image exposure is performed based on the image signal. The image exposure means 13 in this figure forms an electrostatic latent image by scanning the photoconductor drum with its optical path bent by a reflecting mirror 132 via a polygon mirror 131, an fθ lens, etc., which rotate using a laser diode (not shown) as a light source. To be done.

The electrostatic latent image is then developed by the developing device 14. At the periphery of the photoconductor drum 10, a developing device 14 in which a developer including toner such as yellow (Y), magenta (M), cyan (C), and black (K) and a carrier is incorporated, respectively.
First, 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 a ferrite core is coated with an insulating resin around it, a polyester as a main material, a pigment according to the color, and a charge control agent,
The toner is composed of toner to which silica, titanium oxide, etc. are added, and the developer is regulated to a layer thickness of 100 to 600 μm on the developing sleeve 141 by the layer forming means and is conveyed to the developing area for development. At this time, usually the photosensitive drum 1
Development is performed by applying a DC or AC bias potential between 0 and the developing sleeve 141.

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. Third color, 4
The image forming process similar to the second color is performed for the second color,
Visual images of four colors are formed on the peripheral surface of the photosensitive drum 10.

On the other hand, in the monochrome electrophotographic apparatus, the developing device 1
No. 4 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. The transfer material in the present invention is typically a recording paper (transfer paper), but any other material such as a PET base for an overhead projector that can transfer an unfixed toner image is also included.

In the transfer area, the transfer roller 18 is pressed against the peripheral surface of the photosensitive drum 10 in synchronism with the transfer timing, the fed recording paper P is nipped, and a multicolor image is transferred at once. It

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, and the photosensitive drum 10 is discharged.
The toner is separated by the peripheral surface of the sheet and conveyed to the fixing device 20, where the toner is fused by heating and pressurizing the heat roller 201 and the pressure roller 202, and then discharged to the outside of the apparatus through the paper discharge roller 21. The transfer roller 18 and the separation brush 1 described above
After the recording paper P has passed, 9 is retracted and separated from the peripheral surface of the photosensitive drum 10 to prepare for the next toner image formation.

On the other hand, the photosensitive drum 10 after separating the recording paper P removes and cleans the residual toner by the pressure contact of the blade 221 of the cleaning device 22, and again receives the charge removal by 11 and the charge by the charger 12, and the next. Enter the image formation process. When a color image is overlaid 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 an apparatus unit which forms a detachable cartridge in which a photosensitive drum, a charging means, and a cleaning means are integrated.

An 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.

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 above, 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 is an exposure device for printing received data.

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The present invention will be described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto. In addition, "part" in the description represents "part by weight".

The average particle diameter and particle size distribution of the silica used in the examples are adjusted by mixing monodisperse silica or dispersing a commercially available silica having a wide particle size distribution by centrifugal sedimentation or filtration. The one with the adjusted degree of diameter distribution was used.

[Preparation of Silica Particles of Examples and Comparative Examples] Particles for Example 1 Volume average particle diameters of 0.2 μm (DW / DN: 1.00) and 0.5 μm (DW / DN: 1.00) Spherical monodisperse silica (High-Presica: Ube Nitto Kasei Co., Ltd.) was partially mixed. At this time, the number average particle diameter (DN) and the weight average particle diameter (DW) are 0.22 and 0.35 based on the mass and number of each particle, and therefore (DW / D
N) becomes 1.6.

Particles for Examples 2 and 3 and Comparative Examples 1 and 2 In the same manner, the following silica particles were prepared to prepare particles for Examples 2 and 3 and Comparative Examples 1 and 2.

[0095]

[Table 1]

Particles for Example 4 In the particles for Example 1, silica particles were used as Admafine S.
Instead of O-C2 (manufactured by Admatex), the coating liquid used for the second charge transport layer described later was filtered using a 1 μm filter to remove the particle size component on the large particle size side. In the SEM photograph observation of the outermost surface layer, the particle size of 1 μm or more was 0.5%. The distribution of the obtained particles was as follows.

DN: 0.45, DW: 0.90, DW /
DN: 1.98 Particles for Comparative Examples 3 and 4 Monodisperse silica having a colloidal dimension of 0.1 μm or less in the particles for Example 1 (OSCAP: DW / DN = 1.0 manufactured by Catalysis Kasei) and 3 μm monodisperse silica. The particles using (High Precisiona: DW / DN = 1.0, manufactured by Ube Nitto Kasei Co., Ltd.) are designated as particles for Comparative Examples 3 and 4, respectively.

Particles for Examples 5 to 7 In the particles for Examples 1 to 3, silica was sintered at a temperature of 600 ° C.

Particles for Example 8 The silica of the particles for Example 1 was hydrophobized with trimethylmethoxysilane.

Particles for Example 9 In the particles for Example 1, monodispersed silica (DW / DN = 1.0) having an average particle diameter of 2 μm was used.

Examples 1 to 9 and Comparative Examples 1 to 4 On a drum-shaped aluminum conductive substrate (aluminum cylinder) having a diameter of 80 mm, an intermediate layer made of polyamide resin and having a thickness of about 0.1 μm was provided. Next, a coating solution consisting of 30 parts of the charge generating substance (CGM-1) shown in the following chemical formula 7, 10 parts of butyral resin Elex B (BX-L), and 1600 parts of methyl ethyl ketone was applied onto the above intermediate layer by dip coating and dried. A charge generation layer was formed by coating so as to have a film thickness of 0.5 μm.

Then, 400 parts of the charge transport material (T-1),
Polycarbonate resin (Z300: Mitsubishi Gas Chemical Co., Ltd.)
A first charge transport layer was formed by dip coating using a solution of 600 parts dissolved in 3000 parts of dichloromethane, so that the film thickness after drying would be 23 μm.

Further, 400 parts of the charge transport material (T-1) and polycarbonate resin (Z800: manufactured by Mitsubishi Gas Chemical Co., Inc.) 6
The second charge transport layer was formed by dip coating using a solution prepared by dissolving 6 parts of the particles shown in Table 1 in a solution of 0 part dissolved in 3000 parts of 1,2-dichloroethane so that the film thickness after drying would be 1 μm. Was formed.

[0104]

[Chemical 7]

(Evaluation 1) <Evaluation of Electrophotographic Photosensitive Member> The electrophotographic photosensitive member obtained as described above was used as a copying machine Konica U-BIX4 manufactured by Konica Corporation.
The following characteristics evaluation was performed using 045. The results are shown in Table 2.

Evaluation of electrical characteristics / repetition characteristics The above copying machine was modified and equipped with a surface electrometer to charge
When the process of exposure → charge removal was repeated 50,000 times, the first and 50,000th increase in black paper potential and white paper potential increase (ΔVb and ΔVw, respectively) were measured and evaluated.
The black paper potential mentioned here means the surface potential of the photoconductor when a black paper original having a reflection density of 1.3 is copied. Similarly, the blank sheet potential means the surface potential of the photoconductor when copying a blank sheet document having a reflection density of 0.0.

Image evaluation Image samples after copying 50,000 sheets were observed due to background fog, white lines and black lines in halftone images, and deterioration of photoconductor (uneven thickness, electrical characteristics) such as uneven density. I checked for any defects.

Abrasion resistance evaluation The abrasion resistance of the photoconductor was evaluated by the amount of change in the photoconductor film thickness before and after the actual copying test of 50,000 copies. The film thickness of the photoconductor was measured by EDDY 560C manufactured by Fischer.

[0109]

[Table 2]

It can be seen that, although those in the present invention have small potential fluctuations and reductions in film thickness during repeated use, those in the other than the present invention are large in at least one of them, and cause image defects and cleaning defects.

[0111]

EFFECTS OF THE INVENTION According to the present invention, the surface strength of an organic photoconductor is increased so that even if it is repeatedly used, the charging performance is not deteriorated and the thickness of the film is less worn. It is possible to provide a photoreceptor that is hard to stick and has high durability. Furthermore, it is possible to provide a highly reliable electrophotographic apparatus and apparatus unit using this photoreceptor.

[Brief description of drawings]

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

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

[Explanation of Codes] 1 Conductive Support 2 Intermediate Layer 3 Charge Transport Layer (CTL) 4 Charge Generation Layer (CGL) 5 Protective Layer 6 Photosensitive Layer 10 Photoreceptor Drum 11 Exposure Section Using Light Emitting Diodes 12 Scorotron Charger 13 image exposure means 14 developing device 17 paper feed roller 18 transfer roller 19 separation brush 20 fixing device 21 paper discharge roller 22 cleaning device 30 image holding member, charging means, developing means and cleaning means are integrated and removable Cartridge that is a device unit

Claims (6)

[Claims] 1. A volume average particle diameter of 0.1 μm or more and 2 μm or less in an outermost surface layer of an electrophotographic photosensitive member having a photosensitive layer provided on a conductive support, and a number average particle diameter defined by the following formula. (DN) to weight average particle diameter (DW) ratio (DW / D
An electrophotographic photosensitive member comprising inorganic particles, wherein N) is 1 ≦ (DW / DN) ≦ 2. DN = ΣNiDi / ΣNi DW = ΣmiNiDi / ΣmiNi (In the formula, mi represents the mass of particles, Ni represents the number of particles, and Di represents the diameter of particles.) 2. A particle component having a volume average particle size of 0.1 μm or more and 1.0 μm or less and 1.0 μm or more in the outermost surface layer of an electrophotographic photosensitive member having a photosensitive layer provided on a conductive support. Is 1.0 vol% or less, and the electrophotographic photosensitive member is characterized by containing inorganic particles. 3. A volume average particle diameter of 0.1 μm or more and 2 μm or less in an outermost surface layer of an electrophotographic photosensitive member having a photosensitive layer provided on a conductive support, and a number average particle diameter defined by the following formula. (DN) to weight average particle diameter (DW) ratio (DW / D
N) 1 ≦ (DW / DN) ≦ 2, a photoreceptor containing inorganic particles, latent image forming means for forming an electrostatic latent image on the photoreceptor, electrostatic latent image formed on the photoreceptor Developing means for developing a toner image into a toner image, transfer means for transferring the toner image on the photoconductor obtained by the visualizing onto a transfer material, and cleaning for cleaning the toner remaining on the photoconductor after the toner image transfer. An electrophotographic apparatus having means. DN = ΣNiDi / ΣNi DW = ΣmiNiDi / ΣmiNi (In the formula, mi represents the mass of particles, Ni represents the number of particles, and Di represents the diameter of particles.) 4. A particle component having a volume average particle size of 0.1 μm or more and 1.0 μm or less and 1.0 μm or more in the outermost surface layer of an electrophotographic photosensitive member having a photosensitive layer provided on a conductive support. Of 1.0% by volume or less, a photoreceptor containing inorganic particles, a latent image forming means for forming an electrostatic latent image on the photoreceptor, and an electrostatic latent image formed on the photoreceptor being visualized. It has a developing means for forming a toner image, a transfer 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. Characteristic electrophotographic device. 5. The number average particle diameter defined by the following formula, wherein the outermost surface layer of an electrophotographic photosensitive member having a photosensitive layer provided on a conductive support has a volume average particle size of 0.1 μm or more and 2 μm or less. (DN) to weight average particle diameter (DW) ratio (DW / D
N) is a photoreceptor containing inorganic particles satisfying 1 ≦ (DW / DN) ≦ 2, and a charging means for uniformly charging the photoreceptor.
Developing means for visualizing the electrostatic latent image on the photoconductor, transfer means for transferring the toner image visualized on the photoconductor onto a transfer material, and removal of charges on the photoconductor after transfer An electrophotographic apparatus unit, comprising: a charge removing means and at least one cleaning means for cleaning residual toner on the photoconductor after transfer, which are integrally supported and detachably attached to the apparatus main body. DN = ΣNiDi / ΣNi DW = ΣmiNiDi / ΣmiNi (In the formula, mi represents the mass of particles, Ni represents the number of particles, and Di represents the diameter of particles.) 6. A particle component having a volume average particle size of 0.1 μm or more and 1.0 μm or less and 1.0 μm or more on the outermost surface layer of an electrophotographic photosensitive member having a photosensitive layer provided on a conductive support. Of 1.0% by volume or less, a photoconductor containing inorganic particles, a charging unit for uniformly charging the photoconductor, a developing unit for developing an electrostatic latent image on the photoconductor, Transfer means for transferring the toner image visualized on the body onto a transfer material, charge removing means for removing charges on the photoconductor after the transfer, and cleaning means for cleaning residual toner on the photoconductor after the transfer At least one of the above is integrally supported and is detachably attached to the apparatus main body.