JPH0915877A - Image forming method and image forming device - Google Patents

Abstract

PURPOSE: To provide an image forming method, an image forming device and a device unit in which a high sensitivity is provided, wear of a photosensitive layer of a photoreceptor is minimized, and image density is stabilized even when a charging time of the photoreceptor or a time from image exposure to development is short. CONSTITUTION: In an image forming method having processes of charging a photoreceptor 10, developing it with toner after image exposure, transferring a toner image onto a transfer body P, and cleaning the photoreceptor 10 after transfer, a charging time is not more than 0.11 second, or a time from image exposure to development is within 0.15 second, and the photoreceptor 10 having a top layer containing an inorganic particle is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-speed electrophotographic image forming method and image forming apparatus used for color or monochrome copying machines, printers, facsimiles and the like.

[0002]

2. Description of the Related Art In an electrophotographic copying machine of the Carlson method, after uniformly charging the surface of a photoconductor, the charge is erased imagewise by exposure to form an electrostatic latent image. Is developed with toner, and then the toner image is transferred onto paper or the like and then fixed.

On the other hand, the photoreceptor is cleaned and discharged to remove the toner remaining on the surface, and is repeatedly used for a long period of time. Therefore, as an electrophotographic photoreceptor,
In addition to the electrophotographic characteristics such as good charging characteristics and good sensitivity and small dark decay, in addition to physical characteristics such as printing durability, abrasion resistance, moisture resistance after repeated use, and ultraviolet rays during exposure, etc. Good resistance (environmental resistance) is also required.

Recently, selenium, zinc oxide, cadmium sulfide, and other inorganic photoconductors are preferred as electrophotographic photoconductors in view of pollution control, and substances exhibiting various functions in accordance with desired characteristics are selected from a wide range. There is a trend to put the organic photoconductor into practical use.

Conventionally, such an organic photoconductor is mainly used for negative charging. As described in JP-A-60-247647, a thin charge generating layer is provided on a support, and a relatively thick charge is formed thereon. It is configured to have a transport layer. However, since the charge transport layer is composed of a polymer binder, a carrier transport material, etc., it is worn away by the developing sleeve, transfer paper, cleaning member, etc. during use, and gradually loses its initial charge characteristics and light attenuation characteristics. There was a problem that it would not be obtained.

As a binder resin for the outermost surface layer of the photoconductor, for example, a charge transport layer, a polycarbonate resin is preferably used from the viewpoint of electrophotographic characteristics, mechanical strength and the like.
The present situation is that sufficient performance has not yet been obtained in terms of scratch resistance and wear resistance. In addition, introduction of a substituent having a fluorine atom at a carbon between phenylene rings into a polycarbonate resin (JP-A-63-65444), substitution of an alkyl group or a halogen atom into a phenylene ring (JP-A-62-14).
8263), or copolymers of monomers in which both phenylene rings are substituted with a phenyl group or a cyclohexyl group (JP-A-1-269942, JP-A-1-269943).
No.) has been proposed. However, there are still problems such as insufficient surface strength, weakness against abrasion and scratches, deterioration of image quality during repeated use, and decrease in sensitivity due to reduction in film thickness due to abrasion.

Further, recently, in order to obtain a high-speed image forming process and a small-sized image forming apparatus, it is necessary to extremely shorten the charging time of the photosensitive member and the time from image exposure to development. This tendency makes it more difficult to solve the above problems.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a high-speed image forming method, an image forming apparatus, and an apparatus unit using a photoconductor having high sensitivity and having little image quality deterioration and sensitivity deterioration.

[0009]

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

(1) A step of charging the photosensitive member for a time of 0.11 second or less, developing it with toner after image exposure, transferring the toner image on the transfer member, and cleaning the photosensitive member after the transfer. In the image forming method, a photoreceptor having an outermost surface layer containing inorganic particles is used.

(2) Photoreceptor, means for charging the photoreceptor in a time of 0.11 seconds or less, image exposing means, means for developing with toner, means for transferring a toner image onto a transfer body, cleaning of the photoreceptor An image forming apparatus having means, wherein an outermost surface layer uses a photoconductor containing inorganic particles.

(3) At least one of the photoconductor of the image forming apparatus, the charging means, the image exposing means, the developing means, the transfer means, and the cleaning means is integrally detachable from the main body of the apparatus as a unit. (2) The image forming apparatus according to (2).

(4) An image having a step of charging the photoconductor, developing the image with toner within 0.15 seconds after image exposure, transferring the toner image on the transfer body, and cleaning the photoconductor after the transfer. In the forming method, a photoreceptor having an outermost surface layer containing inorganic particles is used.

(5) Photoreceptor, means for charging the photoreceptor, image exposure means, means for developing with toner within 0.15 seconds after image exposure, means for transferring a toner image on a transfer body, photoreceptor An image forming apparatus having a cleaning means, wherein an outermost surface layer uses a photoreceptor containing inorganic particles.

(6) At least one of the photoconductor of the image forming apparatus, the charging unit, the image exposure unit, the developing unit, the transfer unit, and the photoconductor cleaning unit is integrally detachably unitized from the main body of the apparatus. (5) The image forming apparatus according to (5).

(7) The image forming method according to (1) or (4), wherein the inorganic particles have a volume average particle diameter of 0.05 to 2.0 μm.

The reason why the object of the present invention is achieved by the above structure is not always clear. However, there is no doubt that the inclusion of inorganic particles in the outermost surface layer of the photoconductor greatly increases the abrasion resistance of the photoconductor, and contributes to preventing the deterioration of the constituent elements of the photoconductor layer. . It is considered that the film thickness of the photosensitive layer is reduced and the performance is less deteriorated even after repeated use, and therefore rapid and sufficient charging in the charging step of the photoconductor and rapid charge erasing by exposure are possible even after long-term use.

In the present invention, the charging time is the time during which the surface of the photoconductor is effectively charged, and in corona charging, as shown in FIG. On the street.

Charging time (sec) = 1 (mm) / v (mm / sec) Also, the time taken to develop with toner after image exposure is as shown in FIG.
As shown in, the time required for the surface of the photoconductor to move from the position where the photoconductor is exposed (in the figure, 131 is the center of the exposure light if there is a width) to the center of the development area, which is expressed by the following formula. .

Time (sec) = m (mm) / v (mm / sec) from image exposure to development with toner The image exposure means means not only slit exposure used in a normal analog copying machine but also LED array. It can be said that the image exposure means described later such as a laser beam is typical. Further, the developing means broadly refers to the developing means based on the electrophotographic developing method regardless of whether it is a single component or the two components, and the transferring means or the photoconductor cleaning means also broadly refers to the means attached to the apparatus to perform these functions. .

The inorganic particles contained in the outermost surface layer of the electrophotographic photosensitive member of the present invention are preferably hard particles having a Mohs hardness of 4 or more, and do not adversely affect the electrophotographic performance.

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 used, and one of these can be used, or two or more can be used as necessary.

The inorganic particles have a volume average particle size of 0.05 to
2.0 μm, preferably a ratio of major axis / minor axis of 2.0
Less than substantially spherical particles.

The volume average particle diameter of the inorganic particles is 0.05 μ
If it is less than m, sufficient mechanical strength of the surface of the photoreceptor cannot be obtained, and the surface area of the particles becomes large. As a result, the amount of adsorbed water increases and the surface of the photoreceptor wears and is damaged during repeated image formation, resulting in electron Photo performance deteriorates. On the other hand, if it exceeds 2.0 μm, the surface roughness of the photoconductor becomes large, and the cleaning blade is worn or damaged to deteriorate the cleaning characteristics, resulting in poor cleaning and easy occurrence of image blur. When the inorganic particles are substantially spherical, the particles are not indefinite when enlarged to a size (diameter 1 to 10 mm) whose surface shape can be discriminated by an electron microscope, and the ratio of major axis / minor axis is less than 2.0. It is regarded as a sphere. In that case, the wear coefficient of the surface of the photoconductor can be reduced. These effects cannot be expected for conventionally used organic fine particles, that is, for organic particles of less than 0.05 μm. The volume average particle size of the inorganic particles is measured by a laser diffraction / scattering particle size distribution measuring device LA-700 (manufactured by Hikiba Seisakusho).

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 Methoxysilane,
Examples thereof include dodecyltrimethoxysilane, phenyltrimethoxysilane, o-methylphenyltrimethoxysilane, p-methylphenyltrimethoxysilane and the like.

The fatty acids and metal salts thereof include undecyl acid, lauric acid, tridecanoic acid, myristic acid,
Long-chain fatty acids such as palmitic acid, 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, Examples thereof include salts with metals such as sodium and lithium.

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 outermost surface layer of the photoreceptor, and further silica particles having low hygroscopicity and few active hydroxyl groups on the surface are preferably used. To be

Such a silica particle has an endothermic peak in the range of 40 to 200 ° C. by a differential scanning calorimetry method, and in an environment of RH 80%, the energy change amount ΔH of the endothermic peak is 20 J / g or less. 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 10 J / g or less.

The hydrophobic treatment of the silica particles is achieved by reacting the silanol groups on the silica surface with the above-mentioned hydrophobic treatment agent by a chemical reaction.

As a method of hydrophobizing the silica particles, for example, a method of reacting silanol groups with trimethylchlorosilane under high pressure (Kolloid-Z, 149,
39 (1956)), esterification with alcohol (DB
P 1074559) esterification in an autoclave, (Bull. Chem. Soc. Jpn. 49 (1
2), 3389 (1976)) and the like,
In particular, a treatment method using a silane coupling agent is common. The treatment method with a silane coupling agent can be performed by, for example, the method described in “Silane coupling agent” (Shin-Etsu Chemical Co., Ltd.), “Technical data No. Z003” (Toshiba Silicone), or the like.

The silica particles having a low hygroscopicity and a small amount of active species on the surface as described above are formed by chemical flame CVD (Che).
It is produced by the chemical vapor deposition method, but among them, it is preferable to introduce the metallic silicon powder into a mixed gas for combustion, and explosively combust and react it.

Details of this production method are described in, for example, JP-A-60-2.
55602, JP-A-5-193908 and 5-19.
No. 3909, No. 5-193910, No. 5-19392
No. 8, No. 5-196614, and No. 6-107406.

In the manufacturing 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 heat treatment is performed to remove gas phase components and increase A fine silicon powder is obtained. Next, a combustible gas such as LPG and a supporting gas such as oxygen gas are introduced into a 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 production method, high purity silica particles having an endothermic peak energy change ΔH in the differential scanning calorimetry of 10 J / g or less and having a sharp particle size distribution can be obtained. In addition, the particle size distribution can be varied over a wide range according to the purpose.

The silica particles produced as described above contain very few impurities and contain 1 aluminum component.
000 ppm or less, preferably 200 to 1 ppm, calcium component is 300 ppm or less, preferably 50 to 1 p
pm, iron component is 1000 ppm or less, preferably 200
It is set to a range of 1 ppm. A in the silica particles
l and Fe are measured by ICP emission spectrometry, and Ca is measured by flameless atomic absorption spectrometry.

In the present invention, these inorganic particles are contained at least in the outermost surface layer of the electrophotographic photosensitive member together with the binder. The proportion of the inorganic particles in the outermost surface layer is usually 1% by weight or more and 200% by weight or less, based on 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 in which the inorganic particles are contained in the outermost surface 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. 3A shows the intermediate layer 2 on the conductive support 1.
Charge generation material (CGM) and charge transport material (CT
3B is a photoreceptor having a single-layer photosensitive layer 6 containing M) together, and FIG. 3B contains a charge transport material (CTM) as a main component on the conductive support 1 via the 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 photoreceptor having a photosensitive layer 6 which is formed by laminating a charge generation layer (CGL) 4 and a charge transport layer (CTL) 3 in this order on a conductive support 1 with an intermediate layer 2 interposed therebetween.

3 (d), (e), and (f) are protective layers 5 on the photosensitive layers of FIGS. 3 (a), (b), and (c), respectively.
Are 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 a protective layer 5 is further laminated on the photosensitive layer as shown in (d), (e) and (f), 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, but it is more preferable that the protective layer contains a charge transport material (CTM).
By including a charge transport material (CTM) in these protective layers, an increase in the residual potential and a decrease in sensitivity due to repeated use of the electrophotographic photoreceptor can be prevented.

Examples of the charge generating substance (CGM) contained in the photosensitive layer 6 of each of the photoreceptors shown in FIGS. 3A to 3F are, for example, 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.

The charge transport material (CTM) contained in the photosensitive layer 6 is, for example, an oxazole derivative, an oxadiazole derivative, a thiazole derivative, a thiadiazole derivative, a triazole derivative, an imidazole derivative,
Imidazolone derivatives, imidazoline derivatives, bisimidazolidine derivatives, styryl compounds, hydrazone compounds,
Benzidine compound, pyrazoline derivative, stilbene compound, amine derivative, oxazolone derivative, benzothiazole derivative, benzimidazole derivative, quinazoline derivative, benzofuran derivative, acridine derivative, phenazine derivative, aminostilbene derivative, poly-N-vinylcarbazole, poly-1- Vinylpyrene, poly-9-
Vinyl anthracene and the like are mentioned, and these charge transport materials (CTM) are usually layered with a binder.

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

[0048]

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(Wherein Ar ₁ , Ar ₂ and Ar ₄ each represent a substituted or unsubstituted aromatic hydrocarbon group or heterocyclic group,
Ar ₃ represents a substituted or unsubstituted divalent aromatic hydrocarbon group or heterocyclic group, and 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 may combine with each other to form a ring. )

[0050]

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(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, Ar ₅ represents a substituted or unsubstituted aromatic hydrocarbon group or a heterocyclic group, and m is 0 or 1. is there.)

[0052]

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(In the formula, Y is a monovalent substituted or unsubstituted phenyl group, naphthyl group, pyrinyl group, fluorenyl group,
Carbazolyl group, a diphenyl group, and 4,4'-alkylidene diphenyl groups, each substituted Ar _6, Ar ₇ represents an unsubstituted aromatic hydrocarbon group or a heterocyclic group. l is 1
Represents an integer of 3; )

[0054]

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

[0056]

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[0057]

[Chemical 6]

[0058]

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[0059]

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[0060]

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[0061]

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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.

The binder resin contained in the uppermost layer of each of the photoconductors shown in FIGS. 3 (a) to 3 (f) is preferably resistant to mechanical impact 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).

[0064]

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(Wherein 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, and Z is 4 to 11).
A saturated or unsaturated carbocyclic residue having 9 carbon atoms, R ₉ is an alkyl or aryl group having 1 to 9 carbon atoms. )

[0066]

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

[0068]

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(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.)

[0070]

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(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, 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 when forming each of the layers, n-butylamine, diethylamine, ethylenediamine, isopropanolamine,
Triethanolamine, triethylenediamine, N, N
-Dimethylformamide, acetone, methyl ethyl ketone, methyl isopropyl ketone, cyclohexanone, benzene, toluene, xylene, chloroform, dichloromethane, 1,2-dichloroethane, 1,2-dichloropropane, 1,1,2-trichloroethane, 1,1,1 −
Examples thereof include 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. These solvents can be used alone or as a mixture of two or more solvents.

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

The charge-transporting layer is formed by dissolving the above-mentioned 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 10: 1 to 1:10 by weight.

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.

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) 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. Regarding the spray coating, for example, JP-A-3-
90250 and JP-A-3-269238, and the circular amount control type coating is described in detail, for example, in 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, 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 particularly 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 photoconductor 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. It can be widely applied to devices such as printing, plate making, and facsimile.

FIG. 4 shows a schematic configuration example of an image forming apparatus having the electrophotographic photosensitive member of the present invention.

In FIG. 4, reference numeral 10 denotes a photosensitive drum, which is coated with an organic photosensitive layer on the drum, is grounded, and is 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 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
Performs image exposure 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. Developing devices 14 each having a built-in developer composed of toner and carrier such as yellow (Y), magenta (M), cyan (C), black (K), etc., at the periphery of the photosensitive drum 10.
First, development of the first color is performed by a developing sleeve 141 which rotates with a built-in magnet and holding a developer. The developer is a carrier coated with an insulating resin around a ferrite core, a pigment and a charge control agent according to the color with polyester as the main material,
The toner is made of a toner to which silica, titanium oxide or the like is added. The developer is regulated to a layer thickness of 100 to 600 μm on the developing sleeve 141 by a layer forming means, and is conveyed to a developing area to be developed. At this time, usually, the photosensitive drum 1
The 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 image forming process of the second color is started, 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 same image forming process as that for the second color is performed for the second color.
Four color images are formed on the peripheral surface of the photosensitive drum 10.

On the other hand, in the monochrome electrophotographic apparatus, the developing device 1
Reference numeral 4 is composed of one kind of black toner and can form an image 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. Incidentally, the transfer member in the present invention is typically a recording paper (transfer paper), but includes all that can transfer an unfixed toner image including a PET base for an overhead projector.

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, and the supplied 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 pressure contact with the photosensitive drum 10.
The toner is conveyed to the fixing device 20 after being separated by the peripheral surface of the heat roller 201, and the toner is welded by heating and pressing of the heat roller 201 and the pressure roller 202, and then discharged to the outside of the device via the paper discharge 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 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 superimposed on the photoreceptor, the blade 221 moves immediately after cleaning the photoreceptor surface and retreats from the peripheral surface of the photoreceptor drum 10.

Reference numeral 30 is a removable cartridge in which the photoconductor, the charging means, and the cleaning means are integrated.

The electrophotographic apparatus is constructed by integrally combining a plurality of constituent elements such as the above-mentioned photosensitive member and cleaning means as an apparatus unit, and this unit is detachably attached to the apparatus main body. You may. For example, at least one of charging means, developing means and cleaning means
Unit together with the photoconductor to form a unit,
A single unit that can be attached to and detached from the main body of the apparatus may be used, and a guide unit such as a rail of the main body of the apparatus may be used to attach and detach.

When the electrophotographic apparatus is used as a copying machine, the image exposure means is a means for irradiating the photoconductor with reflected light or transmitted light from the original document, or a sensor for reading the original document and converting it into a laser beam according to this signal. Beam scanning, LE
A means for irradiating the photoconductor with light by driving the D array or the liquid crystal shutter array.

When the electrophotographic image forming apparatus is used as a facsimile or a printer, the image exposure means 13 is an exposure means for printing the received data.

[0096]

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

(1) Preparation of Photoreceptor Photoreceptor 1-1 Polyamide resin CM-8000 (Toray Industries, Inc.) 30 g
Was poured into a mixed solvent of 900 ml of methanol and 100 ml of 1-butanol, and dissolved by heating at 50 ° C. After cooling to room temperature, this liquid was used to give an outer diameter of 80 mm and a length of 355.
An intermediate layer having a thickness of 0.5 μm was formed by dip coating on a 5 mm aluminum drum.

Next, 5 g of polyvinyl butyral resin S-REC BX-1 (manufactured by Sekisui Chemical Co., Ltd.) was dissolved in 1000 ml of methyl ethyl ketone (MEK) and further mixed with 10 g of the following "Chemical 15" compound CGM-1.
Dispersion was carried out for 20 hours using a sand mill. Using this solution, a charge generation layer having a thickness of 0.5 μm was formed on the above intermediate layer by dip coating.

Then, 100 g of the exemplified compound T-31
And BPZ type polycarbonate resin Panlite TS-20
50 (Teijin Kasei Co., Ltd.) 150 g dichloromethane 1
Dissolved in 000 ml. Using this solution, a charge transport layer having a thickness of 20 μm was formed on the charge generation layer by dip coating.

Thereafter, 20 g of Exemplified Compound T-31 and BPZ type polycarbonate resin Panlite TS-205 were used.
0 (Teijin Kasei Co., Ltd.) 30 g dichloromethane 100
To a solution dissolved in 0 ml, 10 g of 0.2 μm silica particles treated with a silane coupling agent (Mohs hardness 7.0 spherical) was added and dispersed in an ultrasonic bath for 20 minutes. Using this solution, a surface protective layer having a thickness of 3 μm was formed on the charge transport layer by coating.

Finally, it was heated and dried at 100 ° C. for 1 hour to prepare a photoreceptor in which an intermediate layer, a charge generation layer, a charge transport layer and a surface protective layer were sequentially laminated.

[0102]

Embedded image

Photoreceptor 1-2 Photoreceptor 1-1 except that the silica particles of 0.2 μm were replaced with the silica particles of 0.05 μm (Mohs hardness 7.0 spherical).
A photoreceptor was produced in the same manner as described above.

Photoreceptor 1-3 A photoreceptor was prepared in the same manner as the photoreceptor 1-1 except that the 0.2 μm silica particles were changed to 2.0 μm silica particles (Mohs hardness 7.0 spherical).

Photosensitive member 1-4 A photosensitive member was prepared in the same manner as the photosensitive member 1-1 except that the silica particles of 0.2 μm were changed to the silica particles of 2.5 μm (Mohs hardness 7.0 spherical).

Photoconductor 1-5 A photoconductor was prepared in the same manner as photoconductor 1-1 except that 0.2 μm silica particles were changed to 0.2 μm zirconia (Mohs hardness 7.5) particles.

Photoreceptor 1-6 A photoreceptor was prepared in the same manner as the photoreceptor 1-1 except that the 0.2 μm silica particles were changed to 0.1 μm silica particles (Mohs hardness 7.0 spherical).

Photoreceptor 1-7 A photoreceptor was prepared in the same manner as the photoreceptor 1-1, except that the silica particles of 0.2 μm were replaced with titanium oxide particles of 0.5 μm (Mohs hardness of 6.0).

Photoreceptor 1-8 A photoreceptor was prepared in the same manner as the photoreceptor 1-1, except that the silica particles of 0.2 μm were changed to the alumina particles of 0.5 μm (Mohs hardness 9.0).

Photoreceptor 1-9 A photoreceptor was prepared in the same manner as the photoreceptor 1-1 except that particles were not added.

(2) Evaluation U-BIX4 manufactured by Konica Corporation was used as the photoconductors 1-1 to 1-9.
155 modified machine (charging time 0.082 seconds), U-BIX4
145 modified machine (charging time 0.104 seconds), and U-BI
Mounted on the X3135 modified machine (charging time 0.117 seconds),
The conditions were changed as shown in the table below, and 100,000 copy live-action tests were conducted. Image exposure-development time is 0.16 for each machine.
It was set to 0 seconds.

The evaluation was carried out based on the presence or absence of image defects during actual copying, the amount of change in surface potential before and after actual copying, and the amount of film thickness loss.

<Electrostatic Characteristic Test> The developing device of the copying machine was removed, and a black paper potential (Vb) and a white paper potential (Vw) were measured using a modified machine in which a surface electrometer was installed at that position. 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 original having a reflection density of 1.3, and the white paper potential is a white paper original having a reflection density of 0.0. Is the surface potential of the photoconductor when imagewise exposure is performed. The residual potential is the potential before recharging after removing the charge after cleaning.

<Evaluation of Image> The above-mentioned nine types of photoconductors were sequentially mounted on the respective copying machines, and an original having a halftone was used for 100,
The image was output 000 times. 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 in Film Thickness> The uniform film thickness portion of the photoconductor is measured at 10 points at random, and the average value is taken as the film thickness of the photoconductor. Film thickness meter EDDY 560C (HELMUT
The film thickness after the first time and after 100,000 copies was measured using FISCHER GMBHT CO.), And the difference was defined as the amount of film thickness loss.

[0117]

[Table 1]

As shown in the table above, in the image forming method of the present invention,
It can be seen that even when repeatedly used, there is little wear of the film thickness of the photoconductor, and a stable image can be obtained without a decrease in image density.

Example 2 (1) Preparation of Photoreceptor Photoreceptor 2-1 Polyamide resin CM-8000 (Toray Industries, Inc.) 30 g
Was poured into a mixed solvent of 900 ml of methanol and 100 ml of 1-butanol, and dissolved by heating at 50 ° C. After cooling to room temperature, this liquid was used to give an outer diameter of 80 mm and a length of 355.
An intermediate layer having a thickness of 0.5 μm was formed by dip coating on a 5 mm aluminum drum.

Next, 5 g of polyvinyl butyral resin S-REC BX-1 (Sekisui Chemical Co., Ltd.) was added to MEK100.
It was dissolved in 0 ml, and the exemplary compound CGM-2 10
After mixing g, dispersion was performed for 20 hours using a sand mill. Using this solution, a charge generation layer having a thickness of 0.5 μm was formed by dip coating on the intermediate layer.

Subsequently, 100 g of Exemplified Compound T-31
And BPZ type polycarbonate resin Panlite TS-20
50 (Teijin Kasei Co., Ltd.) 150 g dichloromethane 1
Dissolved in 000 ml. Using this solution, a charge transport layer having a thickness of 20 μm was formed on the charge generation layer by dip coating.

Thereafter, 20 g of Exemplified Compound T-31 and BPZ type polycarbonate resin Panlite TS-205 were used.
0 (Teijin Kasei Co., Ltd.) 30 g dichloromethane 100
To a solution dissolved in 0 ml, 10 g of 0.2 μm silica particles (Mohs hardness 7.0 spherical) treated with a silane coupling agent was added and dispersed in an ultrasonic bath for 20 minutes. Using this solution, a thickness of 3 is obtained by ring coating on the charge transport layer.
A μm surface protective layer was formed.

Finally, it was heated and dried at 100 ° C. for 1 hour to prepare a photoconductor in which an intermediate layer, a charge generation layer, a charge transport layer and a surface protective layer were sequentially laminated.

[0124]

Embedded image

Photoreceptor 2-2 A photoreceptor was prepared in the same manner as the photoreceptor 2-1, except that the silica particles of 0.2 μm were replaced with the silica particles of 0.05 μm (Mohs hardness 7.0 spherical).

Photoreceptor 2-3 A photoreceptor was prepared in the same manner as the photoreceptor 2-1 except that the 0.2 μm silica particles were changed to 2.0 μm silica particles (Mohs hardness 7.0 spherical).

Photoreceptor 2-4 A photoreceptor was prepared in the same manner as the photoreceptor 2-1, except that the silica particles of 0.2 μm were changed to the silica particles of 2.5 μm (Mohs hardness 7.0 spherical).

Photoreceptor 2-5 A photoreceptor was prepared in the same manner as the photoreceptor 2-1 except that 0.2 μm silica particles were changed to 0.2 μm zirconia (Mohs hardness 7.5) fine particles.

Photoreceptor 2-6 A photoreceptor was prepared in the same manner as the photoreceptor 2-1 except that the 0.2 μm silica particles were changed to the 0.1 μm silica particles (Mohs hardness 7.0 spherical).

Photoconductor 2-7 A photoconductor was prepared in the same manner as photoconductor 2-1, except that the silica particles of 0.2 μm were replaced with titanium oxide particles of 0.5 μm (Mohs hardness 6.0).

Photoreceptor 2-8 A photoreceptor was prepared in the same manner as the photoreceptor 2-1, except that the 0.2 μm silica particles were changed to 0.5 μm alumina particles (Mohs hardness 9.0).

Photoconductor 2-9 A photoconductor was prepared in the same manner as the photoconductor 2-1 except that the inorganic particles were not added.

(2) Evaluation U-BIX41 manufactured by Konica Corporation was used as the photoconductors 2-1 to 2-9.
55 modified machine (image exposure-development time 0.113 seconds), UB
IX4145 modified machine (image exposure-development time 0.142
Second) and U-BIX3135 modified machine (image exposure-development time 0.160 seconds) and change the conditions as shown in the table below.
A live-action test of 0,000 copies was conducted. The charging time was 0.117 seconds for each machine.

The evaluation was performed based on the presence / absence of an image defect during actual copying, the amount of change in surface potential of Vb and Vw measured at the developing position before and after actual copying, and the amount of film thickness loss.

Vb: potential of black paper (potential of latent image portion of black original document having reflection density of 1.3 or more) Vw: potential of blank paper (potential of latent image portion of white paper portion of original document)

[0136]

[Table 2]

As shown in the table above, in the image forming method of the present invention,
It can be seen that even when repeatedly used, there is little wear of the film thickness of the photoreceptor, and an image with stable image density can be obtained.

[0138]

According to the present invention, an image forming method having high sensitivity, less wear of the photosensitive layer of the photoconductor, and stable image density even when the charging time of the photoconductor or the time from image exposure to development is short, An image forming apparatus and an apparatus unit can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a charging time in the present invention.

FIG. 2 is a diagram illustrating a time until development with toner after image exposure according to the present invention.

FIG. 3 is a cross-sectional view showing a layer structure of a photoreceptor according to the present invention.

FIG. 4 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 10 Photoreceptor Drum 11 Scorotron Charger as Charging Means 13 Image Exposure Means 14 Development as Developing Means Device 18 Transfer roller that is a transfer unit 20 Fixing device that is a fixing unit 22 Device that is a cleaning unit 30 Image forming apparatus unit

Claims (7)

[Claims] 1. An image having steps of charging a photoreceptor for 0.11 second or less, developing it with a toner after image exposure, transferring a toner image on a transfer body, and cleaning the photoreceptor after the transfer. In the forming method, a photoreceptor having an outermost surface layer containing inorganic particles is used. 2. A photoreceptor, means for charging the photoreceptor in a time of 0.11 seconds or less, image exposing means, means for developing with toner, means for transferring a toner image onto a transfer body, and photoreceptor cleaning means. An image forming apparatus having an outermost surface layer comprising a photosensitive member containing inorganic particles. 3. A photosensitive member of the image forming apparatus and at least one of a charging unit, an image exposing unit, a developing unit, a transferring unit, and a cleaning unit are integrally detachable from the main body of the apparatus as a unit. The image forming apparatus according to claim 2, wherein 4. An image forming process comprising the steps of charging a photoreceptor, developing the image with toner within 0.15 seconds after image exposure, transferring the toner image onto the transfer body, and cleaning the photoreceptor after transfer. In the method, an image forming method is characterized in that a photoconductor whose outermost surface layer contains inorganic particles is used. 5. A photoreceptor, means for charging the photoreceptor, image exposure means, means for developing with toner within 0.15 seconds after image exposure, means for transferring a toner image onto a transfer body, and photoreceptor cleaning. An image forming apparatus having means, wherein an outermost surface layer uses a photoconductor containing inorganic particles. 6. A photosensitive member of the image forming apparatus, and at least one of a charging unit, an image exposing unit, a developing unit, a transfer unit, and a photosensitive member cleaning unit are integrally detachably unitized from a main body of the apparatus. The image forming apparatus according to claim 5, wherein the image forming apparatus comprises: 7. The volume average particle diameter of the inorganic particles is 0.05.
5. The image forming method according to claim 1 or 4, wherein the image forming method is about 2.0 μm.