JPH09152775A - Method and device for forming image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of reducing the wear amount of an electrophotographic photoreceptor body without causing image property such as density deterioration, fogging and cleaning property even when used over a long period, and to provide a method for the device. SOLUTION: This method is provided with a process for developing an electrostatic latent image formed on the electrophotographic photoreceptor by using two component developer. In this case, the developer to be used consists of the magnetic carrier having average volume grain size of >=20μm and <=80μm and containing the magnetic material particle in resin and the non-magnetic toner, or consists of the magnetic toner having average volume grain size of >=4μm and <=9μm and containing the magnetic material particle in the resin. Moreover, the photoreceptor contains inorganic particles in the uppermost layer, and the ten-point average surface roughness (Rz) of the uppermost layer is defined as 0.1 to 1.0μm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method and apparatus using an electrophotographic photosensitive member used in copying machines, printers 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. With toner, then transfer the toner to paper,
Fix it.

On the other hand, the photoconductor has been subjected to removal of adhering toner, static elimination, and surface cleaning, and is repeatedly used for a long period of time.

Therefore, the electrophotographic photosensitive member has, of course, electrophotographic characteristics such as good charging characteristics and sensitivity and small dark decay, as well as printing durability after repeated use, abrasion resistance,
Good physical properties such as moisture resistance, resistance to ozone generated during corona discharge, and resistance to ultraviolet light during exposure (environmental resistance) are also required.

Conventionally, selenium has been used as an electrophotographic photoreceptor.
Inorganic photoconductors having an inorganic photoconductive substance such as zinc oxide and cadmium sulfide as a main component of a photosensitive layer have been widely used. However, in recent years, as a photosensitive layer of an electrophotographic photoreceptor, a carrier generating function and a carrier transporting function are shared by different substances, and a substance exhibiting each function can be selected from a wide range in view of desired characteristics, so that the sensitivity is high. There is a trend toward putting organic photoreceptors with high durability into practical use.

Such a function-separated type organic photoreceptor is conventionally used mainly for negative charging, and is disclosed in JP-A-60-24.
As described in Japanese Patent No. 7647, a structure in which a thin carrier generation layer is provided on a support and a relatively thick carrier transport layer is provided thereon is adopted. However, since this carrier transporting layer is composed of a polymer binder, a carrier transporting substance, etc., it is worn down by the developing sleeve, transfer paper, cleaning member, etc., and is gradually worn away. There was a problem that the characteristics could not be obtained.

In view of such problems, a polycarbonate resin is preferred and used as a binder resin for the charge transport layer, which is the outermost surface layer of the photoreceptor, from the viewpoints of electrophotographic characteristics and mechanical strength. . However, as compared with the inorganic photoconductor, the scratch resistance and the abrasion resistance are inferior and sufficient performance is not obtained at present. Particularly when a resin carrier or magnetic toner containing a magnetic material is used, the carrier or magnetic toner is often attached and the carrier or magnetic toner sandwiched between the cleaning blade and the photoconductor acts as an abrasive and wears out, The scratches tended to be large.

Further, in recent years, laser beam printers and LED printers have become widespread as output devices for computers, and the demand for higher image quality has increased accordingly. Various methods are conceivable for achieving high image quality, but among them, reducing the particle size of the toner and increasing the exposure density are being actively carried out.

However, when the toner particle size is reduced, it is necessary to increase the toner concentration and at the same time reduce the carrier particle size in order to ensure the developability of the toner. In particular, when the carrier particle size is reduced to 80 μm or less, carrier adhesion to the background portion is likely to occur and further wear of the photoreceptor,
The scratches tended to become severe. This tendency is the same even when the magnetic toner is used.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to reduce the amount of wear of an electrophotographic photosensitive member and to provide an image forming method which is free from image defects such as scratches and density reduction on images, fog, and cleaning defects even after long-term use. And to provide a device.

[0011]

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

[1] In an image forming method including a step of developing an electrostatic latent image formed on an electrophotographic photosensitive member with a two-component developer, the developer contains magnetic particles in a resin. Is a developer comprising a magnetic carrier having an average volume particle size of 20 μm or more and 80 μm or less and a non-magnetic toner, and the photoreceptor contains inorganic particles in the outermost surface layer, and the ten-point average surface of the outermost surface layer Roughness (Rz) is 0.1
An image forming method, wherein the image forming method is 1.0 μm.

[2] In an image forming apparatus having an electrophotographic photosensitive member and means for developing an electrostatic latent image formed on the photosensitive member with a two-component developer, the developer is contained in a resin. An average volume particle diameter of 20 μm or more containing magnetic particles,
It is a developer comprising a magnetic carrier of 80 μm or less and a non-magnetic toner, and the photoreceptor contains inorganic particles in the outermost surface layer thereof, and the ten-point average surface roughness (Rz) of the outermost surface layer is 0. An image forming apparatus having a thickness of 1 to 1.0 μm.

[3] The true specific gravity of the carrier is 3.0 g
/ Cm ³ or more and 4.5 g / cm ³ or less, the image forming method described in [1].

[4] In an image forming method including a step of developing an electrostatic latent image formed on an electrophotographic photosensitive member with a one-component developer, the developer contains magnetic particles in a resin. A developer comprising a magnetic toner having a volume average particle diameter of 4 μm or more and 9 μm or less, wherein the photoreceptor contains inorganic particles in the outermost surface layer, and the ten-point average surface roughness (Rz) of the outermost surface layer. Is 0.1 to 1.0 μm.

[5] In an image forming apparatus having an electrophotographic photosensitive member and means for developing an electrostatic latent image formed on the photosensitive member with a one-component developer, the developer is contained in a resin. Volume average particle diameter of 4 μm or more containing magnetic particles, 9
A developer composed of a magnetic toner having a particle size of not more than μm, wherein the photoreceptor contains inorganic particles in the outermost surface layer, and the ten-point average surface roughness (Rz) of the outermost surface layer is 0.1 to 1.0 μm. And an image forming apparatus.

In the two-component type developer used in the items [1] to [3] of the present invention, a magnetic carrier having a relatively small particle size is used in place of the conventional magnetic carrier having a large particle size. On the other hand, it can be obtained by mixing a conventional non-magnetic toner having a small particle size so as to be 5 to 10 wt% in the developer. That is, the conventional developer is liable to have a rough image quality and easily causes a defect such as fog generation and a reduction in resolution.However, the above-mentioned defect is improved by the development for the microtoning, and the allowable range of the toner mixing ratio is increased. And other advantages.

In the developer used in the present invention, the magnetic carrier has a volume average particle diameter of 20 μm or more and 80 μm.
Below, a magnetic resin carrier having a resistance value of 10 ¹² Ωcm or more is used. The carrier is, for example, magnetic particles such as magnetite or ferrite having a volume average particle diameter of 0.1 to 5 μm in a binder resin such as styrene resin, acrylic resin, styrene-acrylic copolymer resin, epoxy resin, coumarone resin, or fluororesin. Is dispersed and contained in an amount of 30 to 80% by weight. The true specific gravity is preferably 4.5 g / cm ³
The following are preferably spherical particles.

The carrier used in the developer should have a true specific gravity of 4.5 g / cm ³ or less. The true specific gravity of the carrier is measured according to JIS K 7112 B method (measurement method by pycnometer method). To be done.

Next, the one-component type developer used in the items [4] and [5] of the present invention has a volume average particle size of 4 μm or more and 9 μm or more.
It is obtained by using a magnetic toner of m or less as a main component and adding a fluidizing agent such as silica if necessary. The magnetic toner is
It is formed by dispersing and containing magnetic particles such as magnetite or ferrite having a volume average particle diameter of 0.1 to 2.0 μm in a binder resin, and the content ratio of the magnetic material to the binder resin is 20 to 70% by weight. desirable.

The volume average particle diameters of the magnetic toner of the one-component developer and the resin-dispersed magnetic carrier of the two-component developer and the non-magnetic toner are measured by a Coulter counter manufactured by Coulter.

As the toner resin for the one-component developer and the two-component developer, well-known resins can be widely used, and styrene-acrylic resin or polyester resin is typical.

Next, the method for measuring the 10-point average surface roughness (Rz) of the outermost surface layer of the electrophotographic photosensitive member of the present invention is JISB0.
601 (reference length 0.25 mm). Specifically, the surface roughness measuring device (SE-3
0H).

Further, as the inorganic particles contained in the outermost surface layer of the photoconductor, particles having a Mohs hardness of 5 or more are preferable because the film strength must be increased and the particles themselves have strength, which adversely affects the electrophotographic performance. Is not given. The Mohs hardness is a relative hardness evaluated by the presence or absence of scratches using a standard substance in which talc is 1 and diamond is 10 in sequence.

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, 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 inorganic particles have a volume average particle diameter of 0.05 μm.
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.

The above-mentioned inorganic particles being substantially spherical means that the surface shape can be discriminated by an electron microscope (diameter 1 to 10 mm).
When the particles are expanded to, the particles are not indefinite and are considered to be spherical with the major axis / minor axis ratio of less than 2.0. In that case, the wear coefficient of the surface of the photoconductor can be reduced. These effects cannot be expected for conventionally used inorganic fine particles, that is, for inorganic 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 Horiba Ltd.).

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 and 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 to the above inorganic particles in an amount of 1 to 10% by weight and coated, 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

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 3% 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.

In the present invention, an organic photoreceptor containing an organic charge generating substance (CGM) and a charge transporting substance (CTM) is preferable. The layer structure of the organic photoreceptor is shown in FIG.

In FIG. 1, a charge generation layer (CGL) 23 and a charge transport layer (CT) are provided on a conductive support 21 with an intermediate layer 22 interposed therebetween.
L) 24 is laminated in this order on the photosensitive layer 26.

FIG. 1B shows a structure in which a protective layer 25 is laminated on the photosensitive layer shown in FIG. Above (a),
(B) shows a typical constitution of the organic photoreceptor, and the present invention is not limited to these layer constitutions. For example, the intermediate layer 22 shown in these figures may be omitted if not required.

Of the above-mentioned layer constitutions, the most preferable embodiment of the present invention is that a protective layer 25 is further laminated on the photosensitive layer and the inorganic particles of the present invention are contained in these protective layers.

The protective layer, if provided, is composed of at least a resin and the inorganic particles of the present invention, but has a layer structure composed of a so-called plurality of charge transport layers containing a charge transport substance (CTM) in the protective layer. Things are more preferable. In this case, the lower layer side is called the first charge transport layer, and the upper layer side is called the second charge transport layer. Inclusion of a charge transport material (CTM) in the second charge transport layer (uppermost layer) can prevent an increase in residual potential and a decrease in sensitivity due to repeated use of the electrophotographic photoreceptor.

The charge generation layers 2 shown in FIGS. 1A and 1B.
Examples of the charge generating substance (CGM) contained in 3 include phthalocyanine pigments, polycyclic quinone pigments, azo pigments, perylene pigments, indigo pigments, quinacridone pigments, azurenium pigments, squarylium dyes, cyanine dyes, pyrylium dyes, thiopyrylium dyes, Examples thereof include xanthene dyes, triphenylmethane dyes and styryl dyes, and these charge generating substances (CGM) are used alone or together with a suitable binder resin to form a layer.

The charge transport material (CTM) contained in the charge transport layer 24 or the protective layer 25 is, for example, an oxazole derivative, an oxadiazole derivative, a thiazole derivative, a thiadiazole derivative, a triazole derivative, an imidazole derivative, an imidazolone derivative, or an imidazoline. Derivative, bisimidazolidine derivative, styryl compound,
Hydrazone compound, 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-vinylanthracene and the like,
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.

[0044]

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(In the formula, Ar ₁ , Ar ₂ and Ar ₄ each represent a substituted or unsubstituted aromatic hydrocarbon group or a heterocyclic group, and A 1
r 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. )

[0046]

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(In the formula, R ₃ and R ₄ each represent a substituted or unsubstituted aromatic hydrocarbon group, a heterocyclic group or an 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.)

[0048]

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(Wherein Y is a substituted or unsubstituted phenyl group,
Naphthyl group, Piriniru group, a fluorenyl group, a carbazolyl group, a diphenyl group, and 4,4'-alkylidene-diphenyl group, Ar _6, Ar ₇ are each substituted, an unsubstituted aromatic hydrocarbon group or a heterocyclic group. l represents an integer of 1 to 3. )

[0050]

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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.

[0052]

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[0053]

[Chemical 6]

[0054]

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[0055]

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[0056]

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[0057]

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The binder resin contained in the charge generation layer (CGL) and charge transport layer (CTL) is a 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-maleic anhydride copolymer resin, urethane resin, silicone resin, epoxy resin, silicone-
Examples thereof include alkyd resin, phenol resin, polysilane resin, and polyvinylcarbazole.

The binder resin contained in the uppermost layer of each of the photoreceptors shown in FIGS. 1 (a) and 1 (b) is preferably resistant to mechanical impact and has high abrasion resistance, and does not impair electrophotographic performance. Things are good. Preferred binder resins include polycarbonate resins having a structural unit represented by the following general formula (I), (II), (III) or (IV).

[0060]

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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. )

[0062]

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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.)

[0064]

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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 alkyl group having 1 to 10 carbon atoms, a cycloalkyl group, or an aryl group.)

[0066]

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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, and k and m are positive integers and k / m. Is selected to be 1 to 10.) The polycarbonate resin having the structural unit represented by the general formula is preferably one having a weight average molecular weight of 30,000 or more.

Next, as a solvent or a dispersion medium used 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. In addition, 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 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 transport layer is formed by dissolving the above charge transport substance and the binder resin in an appropriate 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.

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.

The image forming method of the present invention will be described below with reference to the analog type image forming apparatus of FIG. 2. However, the image forming method of the present invention is not limited to this, and a digital copying machine, an LED It is applicable to general electrophotographic devices such as printers and liquid crystal shutter printers.
Further, the present invention can be widely applied to recording, printing, facsimile, and other devices to which electrophotographic technology is applied.

The toner of the present invention contains a binder, a colorant, a release agent and, if necessary, other additives. The binder constituting the toner is not particularly limited, and various conventionally known resins can be used. For example, styrene resin, acrylic resin, styrene-acrylic resin, polyester resin, etc. may be mentioned. The colorant that constitutes the toner is not particularly limited, and various conventionally known materials are used. Examples thereof include carbon black, nigrosine dye, aniline blue, calcoil blue, chrome yellow, ultramarine blue, deupon oil red, quinoline yellow, phthalocyanine blue, and rose bengal. Other additives include, for example, saltilsan derivatives, charge control agents such as azo metal complexes, and the like. Further, when a magnetic toner is obtained, the colored particles contain magnetic particles as an additive.
In this case, since these magnetic particles are usually black, it is often unnecessary to add a coloring agent.

From the viewpoint of imparting fluidity, inorganic fine particles may be added. As the inorganic fine particles, inorganic oxide particles such as silica, titania and alumina are preferable. Furthermore,
These inorganic fine particles are preferably hydrophobized with a silane coupling agent, a titanium coupling agent, or the like.

Next, an electrophotographic apparatus for carrying out the electrophotographic image forming method will be described with reference to FIG. The photosensitive drum 1 as an electrostatic latent image holder is rotated in the direction of the arrow by a drive system (not shown), and the surface of the drum is first charged by the charger 2. Next, image exposure 4 is applied by an exposure system 3 including an exposure light source, a lens, a mirror, etc., and an electrostatic latent image is formed on the photosensitive drum 1. Next, the latent image is visualized by developing with the charged toner in the developing device 5 on the photosensitive drum 1 by the developing device 5 as a developing process or developing means. On the other hand, the transfer paper (transfer material) supplied from the paper feed unit 6 is brought into contact with the photosensitive drum 1 by the transfer pole 7 in synchronization with the rotation of the photosensitive drum 1, and the toner image on the photosensitive drum 1 is transferred here. Transferred on paper. The untransferred toner remaining on the photosensitive drum is removed by the cleaning blade 9 of the cleaning device 8. Next, the electric charge remaining on the surface of the photoconductor drum 1 is removed by the photocharger (PCL) 10. On the other hand, the transfer paper is sent to the fixing device 13 through the separation electrode 11 and the transport unit 12, and the toner is fixed on the transfer paper by the heat fixing roller 14.

As described above, the transfer material of the present invention can be said to be a typical transfer sheet of plain paper, but if it is a material such as a PET base for OHP (overhead projector) that can transfer an unfixed toner image. Well, it includes those without perfect flatness.

[0078]

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

Example 1 <Preparation of Photoreceptor 1-1> Polyamide resin CM-8000
(Toray Industries, Ltd.) 30 g was put 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 solution is used to
mm on a 355.5 mm long aluminum drum,
An intermediate layer having a thickness of 0.5 μm was formed by dip coating.

Next, 5 g of polyvinyl butyral resin S-Rex BX-1 (Sekisui Chemical Co., Ltd.) was dissolved in 1000 ml of methyl ethyl ketone, and 10 g of Exemplified Compound G1 as a charge generating substance was further mixed, followed by dispersion using a sand mill for 20 hours. did. Using this solution, a charge generation layer having a thickness of 0.5 μm was formed on the above intermediate layer by dip coating.

Further, 100 g of Exemplified Compound T as a charge transport substance and 150 g of BPZ type polycarbonate resin Panlite TS-2050 (Teijin Kasei Co., Ltd.) were dissolved in 1000 ml of dichloromethane. Using this solution, a first charge transport layer having a thickness of 20 μm was formed on the charge generation layer by dip coating.

Furthermore, 20 g of Exemplified Compound T as a charge transport material and 30 g of BPZ type polycarbonate resin Panlite TS-2050 (Teijin Kasei Co., Ltd.) were dissolved in 1000 ml of dichloromethane, and the volume average particle diameter was 0.2 μm. 10 g of the silica particles of was added and dispersed in an ultrasonic disperser tank for 20 minutes. Using this solution, a second charge transport layer having a thickness of 5 μm was formed on the first charge transport layer using a circular amount regulation type coating machine.

Finally, it was heated and dried at 100 ° C. for 1 hour to prepare a photoconductor 1-1 in which an intermediate layer, a charge generation layer, a first charge transport layer and a second charge transport layer were laminated in this order.

[0084]

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<Preparation of Photoreceptors 1-2 to 1-9> Photoreceptors for Examples 1-2 to 1-6 in the same manner as in Photoreceptor 1-1 except that the type of inorganic particles was changed as shown in Table 1. And the photoconductors 1-7 to 9 for comparative examples were obtained.

Ten-point average surface roughness Rz of each of these photoreceptors
(Μm) was measured by the above measuring method, and the obtained results are also shown in Table 1.

[0087]

[Table 1]

<Preparation of Two-Component Developer B1> Magnetic resin carrier having a volume average particle diameter of 50 μm in which 30% by weight of ferrite particles having a volume average particle diameter of 0.2 μm are dispersed and contained in a methylmethacrylate resin. Was produced.

Further, 100 parts by weight of a styrene-acrylic acid ester copolymer resin (1: 1) was added to 10 parts by weight of carbon black.
By weight, 3 parts by weight of nigrosine and 1 part by weight of low molecular weight polypropylene were dispersed and contained to obtain a toner having a volume average particle diameter of 10 μm.

The toner density is 10 with respect to the carrier.
Developer B1 was obtained by mixing the above toners so that the amount of the developer was B1.

<Preparation of Two-Component Developers B2 to B7> Developers B2 to B5 for Examples and B2 to B5 for Examples were prepared in the same manner as Developer B1 except that the carriers in the developers were changed as shown in Tables 2 and 3. Comparative developers B6 to B7 were prepared.

<Image Evaluation Test> Photoreceptors 1-1 to 1-9
Was installed in an improved machine of Konica U-BIX4155 manufactured by Konica Co., Ltd., and developers B1 to B7 were filled in a developing device (contact regular developing system) of the modified machine, and images were obtained in the order of Table 2 and Table 3. An evaluation test was conducted.

Under normal temperature and normal humidity (20 ° C., 60% RH), an original image (coverage rate 10%) having solid black, halftone, blank area, and resolution chart was used to perform 100,000 copying actual copying tests. Then, the thickness loss (μm) of the photoconductor was measured by the following method.

The amount of wear of the photoconductor was calculated from the difference in the film thickness of the photoconductor at the initial stage and after 100,000 copies. The film thickness was measured by randomly measuring 10 parts of the uniform film thickness of the photoconductor. ,
The average value was adopted. The film thickness measuring device is EDDY 560
C (HELMUT FISCHER GMBHT CO
The volume average particle size of the inorganic particles contained in the outermost surface layer of the photoconductor and the volume average particle size of the ferrite particles used in the developer are LA-700. (Manufactured by Horiba Ltd.).

Image evaluation was performed by the following method.

Maximum Density (Dm) The reflection density of a solid black image was measured with a Sakura Densitometer PDA65 manufactured by Konica Corporation.

The image on the blank fog portion was visually evaluated.

Image defects: Line-shaped or spot-shaped scratches, unevenness and image blur were visually evaluated.

The resolution was evaluated by observing a resolution chart in which parallel lines of 1 line / mm to 10 lines / mm were drawn.

5 lines / mm or more: good 3-4 lines / mm: not at a practical level 1-2 lines / mm: defective

[0101]

[Table 2]

[0102]

[Table 3]

From Tables 2 and 3, in each of the examples, a high-quality image having a small amount of film thickness loss, a high resolution and a high maximum density and no fog can be obtained, but in the comparative example, at least one of the characteristics is problematic. Therefore, there is a problem in practicality.

Example 2 <Preparation of Photoreceptor 2-1> Polyamide Resin CM-8000
(Toray Industries, Ltd.) 30 g was put 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 solution is used to
mm on a 355.5 mm long aluminum drum,
An intermediate layer having a thickness of 0.5 μm was formed by dip coating.

Next, 5 g of polyvinyl butyral resin S-Rex BX-1 (Sekisui Chemical Co., Ltd.) was dissolved in 1000 ml of methyl ethyl ketone, and 10 g of Exemplified Compound G1 as a charge generating substance was further mixed, followed by dispersion using a sand mill for 20 hours. did. Using this solution, a charge generation layer having a thickness of 0.5 μm was formed on the above intermediate layer by dip coating.

Further, 100 g of Exemplified Compound T as a charge transport material and 150 g of BPZ type polycarbonate resin Panlite TS-2050 (Teijin Kasei Co., Ltd.) were dissolved in 1000 ml of dichloromethane. Using this solution, a first charge transport layer having a thickness of 20 μm was formed on the charge generation layer by dip coating.

Furthermore, 20 g of Exemplified Compound T as a charge transporting substance and 30 g of BPZ type polycarbonate resin Panlite TS-2050 (Teijin Kasei Co., Ltd.) were dissolved in 1000 ml of dichloromethane, and the volume average particle diameter was 0.2 μm. 50 g of silica particles of 1 was added and dispersed in an ultrasonic disperser tank for 20 minutes. Using this solution, a second charge transport layer having a thickness of 5 μm was formed on the first charge transport layer using a circular amount regulation type coating machine.

Finally, it was heated and dried at 100 ° C. for 1 hour to prepare a photoconductor 2-1 in which an intermediate layer, a charge generation layer, a first charge transport layer and a second charge transport layer were laminated in this order. The surface roughness Rz was 0.15 μm.

<Preparation of Photoreceptor 2-2> A photoreceptor 2-2 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 0.03 μm. The surface roughness Rz was 0.08 μm.

<Preparation of Photoreceptor 2-3> A photoreceptor 2-3 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. The surface roughness Rz was 0.85 μm.

<Preparation of Photoreceptor 2-4> A photoreceptor 2-4 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. The surface roughness Rz was 1.15 μm.

<Preparation of Photoreceptor 2-5> A photoreceptor 2-5 was prepared in the same manner as the photoreceptor 2-1 except that the 0.2 μm silica particles were changed to 0.2 μm zirconium particles. The surface roughness Rz was 0.16 μm.

<Preparation of Photoreceptor 2-6> A photoreceptor 2-6 was prepared in the same manner as the photoreceptor 2-1 except that the 0.2 μm silica particles were changed to 0.1 μm silica particles. The surface roughness Rz was 0.11 μm.

<Preparation of Photoreceptor 2-7> Except that the silica particles of 0.2 μm were changed to titanium oxide particles of 0.5 μm,
Photoconductor 2-7 was prepared in the same manner as photoconductor 2-1. The surface roughness Rz was 0.21 μm.

<Preparation of Photoreceptor 2-8> A photoreceptor 2-8 was prepared in the same manner as the photoreceptor 2-1 except that the silica particles of 0.2 μm were changed to the alumina particles of 0.5 μm. The surface roughness Rz was 0.24 μm.

<Production of Photoreceptor 2-9> Photoreceptor 2-9 was prepared in the same manner as photoreceptor 2-1 except that the first charge transport layer was 30 μm and no fine particles were added to the second charge transport layer. Was produced. The surface roughness Rz was 0.02 μm.

<Preparation of One-Component Developer B10> Styrene-
Volume average of 100 parts by weight of acrylic acid ester copolymer resin (1: 1), 40 parts by weight of ferrite particles having a volume average particle diameter of 0.2 μm, 5 parts by weight of carbon black, and 1 part by weight of low molecular weight polypropylene. Particle size 8.5 μm
Magnetic toner of Hydrophobic silica 0.1% by weight was added as a fluidizing agent to the magnetic toner to obtain a one-component developer 10.

<Preparation of One-Component Developers B11 to B15> The same procedures as in Developer 10 were conducted except that the volume average particle diameter of the magnetic toner, which is the main component of the developer, was changed as shown in Table 4. Example single-component developers B11 to B15 were obtained.

<Image Evaluation Test> Photoreceptors 2-1 to 2-9
Konica U-BIX 415 manufactured by Konica Corporation
The developing device of No. 5 was mounted on a modified machine obtained by modifying the non-contact jumping development system, and the developers B10 to B15 were filled in the developing machine of the modified machine, and the image evaluation test was conducted in the order of Table 4. .

An original image (coverage: 10%) having solid black, halftone, white paper portion, and resolution chart at room temperature and normal humidity (20 ° C., 60% RH) was used, and Dsd was used as a developing condition.
500 μm, developer layer thickness 200 μm, DC-200V,
A copy test was carried out 100,000 times by a non-contact regular development system under a bias of AC1 KHz and P-P2 KV.

The amount of film thickness loss of the photoconductor after 100,000 copies with respect to the initial stage of the copy test was measured in the same manner as in Example 1, and the results are shown in Table 4.

The image density of 100,000 copies, image defects and resolution were measured in the same manner as in Example 1, and the results are shown in Table 4.

[0123]

[Table 4]

In Examples 2-1 to 2-6 in the present invention, the film thickness of the photoconductor is less worn, and there is no image characteristic or cleaning failure. On the other hand, Comparative Example has at least a problem in any of the characteristics. I know there is.

[0125]

EFFECTS OF THE INVENTION According to the present invention, (1) In two-component system development using a resin dispersion type carrier, even when used for a long time, there is little film thickness loss, high maximum density, little fogging, image defects and cleaning defects. It is possible to provide an image forming method and an apparatus that does not have such an image forming apparatus.

(2) It is possible to provide an image forming method and apparatus which are free from film thickness loss, have a high maximum density, have little fogging, and are free from image defects and cleaning defects even when used for a long time in one-component system development. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a photoconductor according to the present invention.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor drum 2 Electrode 3 Optical part 4 Image exposure 5 Developing device 8 Cleaning device 9 Cleaning blade 13 Fixing device 14 Fixing roller

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location G03G 9/107 G03G 9/08 101 13/08 9/10 331 15/09 13/08 Z

Claims (5)

[Claims] 1. An image forming method including a step of developing an electrostatic latent image formed on an electrophotographic photosensitive member with a two-component developer, wherein the developer contains magnetic particles in a resin. A developer comprising a magnetic carrier having a volume average particle diameter of 20 μm or more and 80 μm or less and a non-magnetic toner, wherein the photoreceptor contains inorganic particles in the outermost surface layer, and the ten-point average surface roughness of the outermost surface layer is (Rz) is 0.1-1.0 μm
An image forming method, characterized in that: 2. An image forming apparatus having an electrophotographic photosensitive member and means for developing an electrostatic latent image formed on the photosensitive member with a two-component developer, wherein the developer is magnetic in resin. Volume average particle diameter of 20 μm or more containing body particles, 80 μ
It is a developer comprising a magnetic carrier having a particle size of m or less and a non-magnetic toner, and the photoreceptor has inorganic particles in the outermost surface layer, and the ten-point average surface roughness (Rz) of the outermost surface layer is 0. 1
An image forming apparatus having a thickness of 1.0 μm. 3. The true specific gravity of the carrier is 3.0 g / cm.
The image forming method according to claim 1, wherein the amount is ³ or more and 4.5 g / cm ³ or less. 4. An image forming method having a step of developing an electrostatic latent image formed on an electrophotographic photosensitive member with a one-component developer, wherein the developer contains magnetic particles in a resin. A developer comprising a magnetic toner having a volume average particle diameter of 4 μm or more and 9 μm or less, wherein the photoreceptor contains inorganic particles in the outermost surface layer, and the ten-point average surface roughness (Rz) of the outermost surface layer is An image forming method, wherein the image forming method is 0.1 to 1.0 μm. 5. An image forming apparatus having an electrophotographic photosensitive member and means for developing an electrostatic latent image formed on the photosensitive member with a one-component developer, wherein the developer is magnetic in resin. A developer comprising a magnetic toner containing body particles and having a volume average particle size of 4 μm or more and 9 μm or less, wherein the photoreceptor contains inorganic particles in the outermost surface layer, and the ten-point average surface roughness of the outermost surface layer is (Rz) is 0.1 to 1.0 μm.