JPH1026845A - Image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably form an image for a long time by incorporating a fluorocarbon resin into a carrier in a developer, incorporating fine particles into a photoreceptor, and using a blade cleaning method as a cleaning means so that the photoreceptor itself can be slightly and uniformly polished. SOLUTION: This photoreceptor 2 has a layer containing fine particles on the surface of a photosensitive layer. The fine particles are preferably inorg. fine particles having >=5 Mohs' hardness, and titanium oxide or silica can be used. As for org. fine particles, crosslinked org. fine particles are preferable, and condensed org. fine particles such as vinyl org. fine particles and crosslinked silicone resin particles can be used. The fluorocarbon resin to be incorporated into the carrier of the developer is preferably a homopolymer or copolymer having the monomer unit expressed by formula or by CH2 =CF2 and CF2 =CF2 . In formula, R is a hydrogen atom or methyl group, Rf is an alkyl group or allyl group having at least one fluorine atom as substituent. A blade cleaning method 1 is used as a cleaning means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming method used for a copying machine, a printer and the like.

[0002]

2. Description of the Related Art In recent years, electrophotographic photoconductors are shifting from inorganic photoconductors such as selenium to organic photoconductors in view of prevention of environmental pollution. As the organic photoreceptor, a so-called laminated organic photoreceptor comprising a charge generation layer and a charge transport layer on a conductive support via an adhesive layer as necessary is used. Although the charge transport layer is made of a resin containing a charge transport material, abrasion occurs due to a process such as cleaning for removing toner remaining in a developing unit and transfer during use over time, It has problems with long-term use.

In order to solve this problem, Japanese Patent Laid-Open No.
JP-A-18667 discloses an organic photoreceptor having a coating layer in which hydrophobic silica is dispersed, and JP-A-57-30846 discloses a protective layer containing fine particles of a metal or metal oxide having an average particle size of 0.3 μm or less. Configuration, JP-A-1-205
No. 171 discloses a photoreceptor having a protective layer containing an inorganic filler. In each case, various fine particles are added to the surface layer of the photoreceptor to improve the wear resistance of the photoreceptor. The purpose is to improve the durability of the photoreceptor by reducing the abrasion resistance.

However, when such a highly durable photoreceptor is used, the photoreceptor itself hardly wears out, and although the durability is improved due to the problem of wear, the adhesion to the photoreceptor surface is reduced. When it occurs, it is difficult to remove it, so that it is not possible to prevent the problem caused by the attached matter. In the case of a conventional abradable photoreceptor, the surface of the photoreceptor is gradually polished, and as a result, a new surface state can be constantly maintained. In particular, the adsorption of water or the like is likely to occur when used for a long period of time, and the adsorption of water leaks electric charges on the surface of the photoreceptor, causing a problem of image deletion. This phenomenon often occurs particularly in a high-temperature and high-humidity environment. Since the abrasion of the photoreceptor is reduced and the photoreceptor is less likely to be worn, it is difficult to remove a portion of the water adsorbed on the photoreceptor oxidized by ozone or the like. Problems such as blurring also occur.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an effect of finely and uniformly polishing a photoreceptor itself when a photoreceptor which does not easily wear out is used, so that an image can be formed over a long period of time. An object of the present invention is to provide an image forming method capable of stably forming an image.

In particular, it is an object of the present invention to provide an image forming method capable of stably forming an image for a long period of time in a high-temperature and high-humidity environment where moisture adsorption is likely to occur.

[0007]

The above objects of the present invention have been attained by the following constitutions.

(1) The electrostatic latent image on the organic photoreceptor is contact-developed with a developer comprising a toner and a carrier to form a toner image, and the toner remaining on the photoreceptor after the toner image is transferred to a transfer material. In the image forming method for cleaning,
The carrier is a carrier containing a fluororesin,
An image forming method, wherein the photoconductor is a photoconductor containing fine particles, and the cleaning unit is blade cleaning.

(2) The electrostatic latent image on the organic photoreceptor is contact-developed with a developer comprising a toner and a carrier to form a toner image, and the toner remaining on the photoreceptor after the toner image is transferred to a transfer material. In the image forming method for cleaning,
The carrier is a carrier containing a fluororesin,
The photoreceptor has a plurality of charge transport layers, and the weight average molecular weight of the resin contained in the charge transport layer on the outermost surface thereof is larger than the weight average molecular weight of the resin contained in the other charge transport layers. And an image forming method, wherein the cleaning means is blade cleaning.

(3) The fluororesin described in (1) or (2), wherein the fluororesin is a homopolymer or a copolymer having a monomer unit represented by the following general formula (1), structural formula-4 or structural formula-5. Image forming method.

[0011]

Embedded image

In the formula, R represents a hydrogen atom or a methyl group;
Rf represents an alkyl group or an allyl group in which at least one fluorine atom has been substituted.

The present invention will be described in more detail. That is,
Since the photoconductor itself is not easily polished, abrasion of the photoconductor surface due to cleaning does not occur. However, in the present invention,
Since the carrier contains a fluororesin in the contact development, a very small amount of the fluororesin adheres to the surface of the photoreceptor during the contact development. The adhered fluororesin has a cleavage property, and the resin adheres to the photoreceptor, so that in blade cleaning, the coefficient of friction between the blade and the photoreceptor can be reduced. Bounding and partial edge turn-up can be prevented, and the photoreceptor can be uniformly and finely polished to efficiently remove adsorbed moisture and oxidized components present on the photoreceptor surface. As a result, a stable image can be obtained over a long period of time, and the image can be kept stable even in an environment susceptible to moisture such as a high-temperature and high-humidity environment.

<Photoreceptor> In the present invention, the photoreceptor is formed by laminating a charge generating layer and a charge transporting layer on the surface of a conductive substrate via an undercoat layer, if necessary, or mixing a charge generating substance and a charge transporting substance. This is a photoreceptor having a photosensitive layer formed thereon and a layer containing fine particles formed on the surface thereof. In this case, a separate layer may not be formed, and a method of forming a fine particle layer on the surface by dispersing fine particles throughout the photoconductor layer may be used.

As the conductive substrate, a metal plate such as aluminum, stainless steel, iron or the like, or a flexible support such as paper or plastic film, is provided with a metal layer such as aluminum, palladium or gold by lamination or vapor deposition. Examples thereof include those obtained by applying or depositing a layer containing a conductive compound such as a conductive polymer, indium oxide, or tin oxide on the surface of a flexible support such as paper or a plastic film.

The undercoat layer used if necessary includes casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, polyvinyl butyral, phenolic resin, polyamides (nylon 6, nylon 66, alkoxymethylated Nylon, etc.), polyurethane, gelatin, aluminum oxide and the like are used. The thickness of the undercoat layer is preferably from 0.1 to 10 μm, particularly preferably from 0.1 to 5 μm.

The charge generation layer is a layer containing a charge generation material, and is not particularly limited. Examples of the charge generation material include a phthalocyanine pigment, a polycyclic quinone pigment, an azo pigment, a perylene pigment, and an indigo. Pigments, quinacridone pigments, azurenium pigments, squarylium dyes, cyanine dyes, pyrylium dyes, thiopyrylium dyes, triphenylmethane dyes, styryl dyes, and the like can be used, and these are formed alone or dispersed in a resin. The resin used here is styrene-
Acrylic resin, bisphenol A type polycarbonate,
Bisphenol Z-type polycarbonate, polyester resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, styrene resin, polyvinyl acetate, styrene-butadiene resin, vinylidene chloride-acrylonitrile resin, vinyl chloride-vinyl acetate resin, vinyl chloride-vinyl acetate -Maleic anhydride resin, silicone resin,
Examples include silicone alkyd resin, phenol formaldehyde resin, polyvinyl acetal resin, polyvinyl butyral resin, and the like.

The charge transporting layer is a layer containing a charge transporting substance and is not particularly limited as the charge transporting substance. Examples thereof include oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, and triazole derivatives. , Imidazole derivatives, imidazolone derivatives, imidazoline derivatives, bisimidazolidine derivatives, styryl compounds, hydrazone compounds, benzidine compounds, pyrazoline derivatives, stilbene compounds, amine derivatives, oxazolone derivatives, benzothiazole derivatives, benzimidazole derivatives, quinazoline derivatives Benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilbene derivatives, poly-N-vinylcarbazoles, poly-1-vinylpyrenes, poly-9-vinylant Mosses and the like. These are formed singly or in combination and dispersed or dissolved in a resin. The resin used here is styrene-
Acrylic resin, bisphenol A type polycarbonate,
Bisphenol Z-type polycarbonate, polyester resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, styrene resin, polyvinyl acetate, styrene-butadiene resin, vinylidene chloride-acrylonitrile resin, vinyl chloride-vinyl acetate resin, vinyl chloride-vinyl acetate -Maleic anhydride resin, silicone resin,
Examples include silicone alkyd resin, phenol formaldehyde resin, polyvinyl acetal resin, polyvinyl butyral resin, and the like. The thickness of the charge transport layer is 5 to 50 μm, preferably 10 to 40 μm.
It is.

In the case of a photoreceptor layer composed of a mixture of a charge transport material and a charge generation material, the charge transport material and the charge generation material are appropriately mixed and dispersed in the resin described above. It is obtained by forming a layer later. in this case,
The thickness of the layer is 5 to 50 μm, preferably 10 to 40 μm.

The fine particles used in the layer containing fine particles according to the present invention may be either inorganic fine particles or organic fine particles. The inorganic fine particles are not particularly limited, but those having a Mohs hardness of 5 or more are preferable. Specifically, oxides such as titanium oxide, silica, zirconium oxide and alumina; nitrides such as carbon nitride, aluminum nitride and silicon nitride; carbides such as silicon carbide; titanate compounds such as strontium titanate and barium titanate And so on.

The Mohs hardness of the inorganic fine particles indicates the Mohs hardness of a substance having the material. The Mohs hardness is a relative hardness that is evaluated based on the presence or absence of scratches using a standard material in which talc is 1 and diamond is 10 in sequence.

As the organic fine particles, crosslinked organic fine particles are particularly preferable. The crosslinked organic fine particles are organic fine particles in which an insoluble content in a solvent is 30% or more. Specifically, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-phenylstyrene, p-ethylstyrene, , 4-dimethylstyrene, pt-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene and pn-dodecylstyrene. Styrene or styrene derivatives, methyl methacrylate, ethyl methacrylate, n-methacrylic acid
Butyl, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, diethylaminoethyl methacrylate, dimethylaminoethyl methacrylate Methacrylate derivatives, such as methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-acrylate
-Butyl, isobutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate, acrylate derivatives such as phenyl acrylate, etc., ethylene, propylene,
Olefins such as isobutylene, halogenated vinyls such as vinyl chloride, vinylidene chloride, vinyl bromide and vinyl fluoride, vinyl esters such as vinyl propionate, vinyl acetate and vinyl benzoate, vinyl methyl ether, vinyl ethyl ether, etc. Vinyl ketones such as vinyl ethers, vinyl methyl ketone, vinyl ethyl ketone and vinyl hexyl ketone; N-vinyl compounds such as N-vinyl carbazole, N-vinyl indole and N-vinyl pyrrolidone; vinyl compounds such as vinyl naphthalene and vinyl pyridine , Acrylonitrile, methacrylonitrile, vinyl monomers such as acrylic acid or methacrylic acid derivatives such as acrylamide, divinylbenzene, ethylene glycol diacrylate, ethylene glycol dimethacrylate, Vinyl obtained by adding and polymerizing a polyfunctional vinyl compound such as ethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, and trimethylolpropane triacrylate. Organic fine particles, and condensed organic fine particles such as polyurethanes, polyureas, crosslinked polyesters, and crosslinked silicone resins formed by condensation of polyvalent isocyanates and polyvalent amines.

These fine particles have a number average primary particle size of 0.1.
It is preferably from 1 to 5 μm. More preferably, 0.
05 to 2 μm. If the particle size is large, the surface layer itself becomes brittle, so that the intended improvement in durability cannot be achieved, and the presence of the fine particles may damage the cleaning mechanism. When the particle size is small,
There is no improvement in hardness due to the presence of the fine particles, and the durability does not improve.

Further, the volume resistance of these fine particles themselves is 1
0 ⁸ or more Ωcm is preferable. If the resistance is lower than this range, the resistance of the surface is reduced, the charge retention function is reduced, and a problem of causing image defects is induced.

When the surface layer is formed, it can be formed by dispersing the fine particles in a resin and applying the dispersion. The constituent resin is not particularly limited, for example, styrene-acrylic resin, bisphenol A type polycarbonate, bisphenol Z type polycarbonate, polyester resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, styrene resin, Polyvinyl acetate, styrene-butadiene resin, vinylidene chloride-acrylonitrile resin, vinyl chloride-vinyl acetate resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone alkyd resin, phenol formaldehyde resin, polyvinyl acetal resin, polyvinyl butyral resin Etc. can be given. The content of the fine particles in these resins is 1 to 200 parts, preferably 5 to 10 parts per 100 parts of the resin.
0 parts. When the amount is less than 1 part, the amount of the fine particles is too small, and the effect of improving the hardness is not exhibited. When the amount exceeds 200 parts, the hardness is improved, but the amount of the fine particles is excessive due to the excessive amount of the fine particles. Scattering occurs and causes image defects.

Further, in the present invention, the surface layer is 0.2
When this layer is thin, the effect of improving the durability of the present invention is not exhibited, and when the layer is thick, the effect of improving the durability is not exhibited. However, image defects due to light scattering and a problem of a decrease in sensitivity occur.

In the present invention, it is preferable that the layer containing fine particles contains a charge transporting substance.
That is, since a specific surface layer is not formed by containing the charge transport material, the charge is uniformly transported, and the charge distribution according to the image can be stably formed. The content ratio of this charge transport material in the surface layer is 30 to 30 parts per 100 parts of the resin constituting the protective layer.
0 parts, preferably 50 to 200 parts.

In the present invention, in the structure having a plurality of charge transporting layers, the weight average molecular weight of the resin for forming the outermost charge transporting layer is less than the weight of the resin forming the other charge transporting layers. It must be larger than the average molecular weight. In this case, the aforementioned fine particles may be contained,
Further, it may not contain fine particles.

The weight average molecular weight of this resin is usually 1 × 1
0 ⁴ are of to 1 × 10 ^6, the ratio of the molecular weight of the resin (Mw2) that constitute the molecular weight of the resin contained in the charge transport layer constituting the surface and (Mw1) Other charge transport layer (Mw
(1 / Mw2) is preferably 1.5 or more. When the molecular weight ratio is 1.5 or less, the wear resistance of the outermost layer itself decreases, and the life of the photoconductor itself decreases. The resin contained in the charge transport layer constituting the outermost layer preferably has a weight average molecular weight of 5 × 10 ⁴ to 1 × 10 ⁶ .

<Construction of Carrier> The construction of the coating material of the carrier according to the present invention is not particularly limited as long as it is a fluororesin, and all known resins can be used. For example, polyfluorinated acrylate resin, polyfluorinated methacrylate resin, polyfluorinated vinylidene resin, polyhexafluoropropylene resin, and copolymers by appropriate combinations thereof, and copolymers with other resins, and the like, What is necessary is just to select suitably according to the objectives, such as control of chargeability. Preferably, it is a homopolymer or a copolymer having a monomer unit represented by the general formula (1), Structural Formula-4 or Structural Formula-5, and specifically, a homopolymer or a copolymer having the following monomer units is exemplified.

[0031]

Embedded image

Since the homopolymer of the structural formula-4 or 5 is hardly soluble in a solvent, it is necessary to prepare fine particles and mechanochemically coat the carrier or form a copolymer with 6-fluoropropylene or the like. Thereby, the solubility in a solvent can be improved, and the carrier core can be coated with the solvent.

Further, as disclosed in JP-A-4-123068, an intermediate layer may be provided between the core and the core in order to firmly adhere the fluororesin.

The production method may be as follows. A coating resin may be dissolved in a solvent, sprayed into a fluidized bed and coated on a core, or fine particles of a fluororesin may be coated mechanochemically by mechanical impact. May be. Further, a method in which fluorocarbon resin particles are electrostatically adhered to core particles and then thermally fused to coat the core particles is also preferably used.

The thickness of the coating resin is 0.05 to 20 μm,
Preferably, it is 0.1 to 4 μm.

As the carrier core serving as the core material of the resin-coated carrier, various conventionally known magnetic carrier cores can be used. For example, ferromagnetic metals such as ferrite, magnetite, and iron, cobalt, and nickel, or alloys or compounds containing these metals can be used. Here, ferrite is a general term for a magnetic oxide containing iron and a monovalent or divalent metal, and manganese, iron, nickel, cobalt,
Copper, zinc, magnesium and the like can be mentioned, and the monovalent metal can be lithium and the like. Further, magnetic particles obtained by dispersing the above-described magnetic powder in a resin may be used as a carrier core.

Specifically, (MO) _a (M'O) _b (Fe
Ferrite represented by ₂ O ₃ ) _c (wherein, M and M ′ are metal elements and a, b and c are integers) is preferable, and M−M ′ is Cu—Z
n, Ni-Zn, Mn-Zn, and Cu-Mg are preferred.
Further, (Li ₂ O) _d (Fe ₂ O ₃ ) _e (d and e are integers)
Is also preferably used, and a part thereof may be substituted with an alkaline earth metal oxide.

The size of the carrier core is preferably from 10 to 200 μm in consideration of frictional charging with the toner and adhesion of the carrier to the photoreceptor.

<Cleaning Mechanism> Mechanisms for cleaning the toner remaining on the photoreceptor used in the present invention include a blade cleaning system, a magnetic brush cleaning system, and a fur brush cleaning system. In combination with the blade cleaning method using the above, an effect is exhibited.

As this configuration, any of the configurations shown in FIGS. 1 and 2 can be used. 1 and 2, the cleaning blade 1 is held by the holder 3. FIG. The number of photosensitive members is 2. The angle formed by the holder and the photoreceptor is such that θ ₁ shown in FIGS. 1 and 2 is 10 to 90 °, preferably 15 to 90 °.
75 °. As a material constituting the cleaning blade itself, an elastic body such as silicon rubber or urethane rubber can be used. In this case, the rubber hardness is 30 to
90 ° is better. The thickness is preferably 1.5 to 5 mm, and the length outside the holder is preferably 5 to 20 mm. The pressure contact force on the photoreceptor is preferably 5 to 50 gf / mm.

<Structure of Developing Method> When a toner image is formed using a two-component developer composed of a toner and a carrier, a sufficient image density and faithfulness with no disturbance to the original are obtained at the time of developing the toner after the formation of the latent image. In order to obtain a clear image, the supply of the developer to the developing site in a timely and spatially uniform manner, the latent image charge holding stability of the latent image carrier (photoreceptor), and the physical properties of the developer are affected. .

In general, the developer is supplied to the developing portion by using a developing sleeve having a magnet group for forming a magnetic field.
When only the sleeve rotates, the rotation is performed by, for example, rotating the magnet group and the sleeve in the same or opposite directions. In order to exert the effect more in the present invention, it is preferable that the surface of the photoconductor is in contact with the developer conveyed to the developing nip (contact development), whereby the fluororesin of the carrier coating agent is appropriately applied to the surface of the photoconductor. And uniform blade cleaning becomes possible.

For example, as a specific configuration when the magnet group is fixed and the sleeve rotates, the gap between the photosensitive member and the developing sleeve is 0.1 to 2.0 mm, preferably 0.3 to 2.0 mm.
1.5 mm, the gap between the spike regulating member and the sleeve is 0.1 mm.
05 to 1.8 mm, preferably 0.2 to 1.4 mm.

<Developer> The toner used in the present invention is a toner in which the inorganic fine particles of the present invention are added to and mixed with colored particles containing a binder resin, a colorant, and other additives used as required. is there. The average particle size is usually from 1 to 30 μm, preferably from 5 to 15 μm, as a volume average particle size. There is no particular limitation on the binder resin constituting the colored particles, and various conventionally known resins are used. For example, a styrene resin, an acrylic resin, a styrene / acrylic resin, a polyester resin, and the like can be given. The colorant is not particularly limited, and is conventionally known for color toners, such as carbon black, nigrosine dye, aniline blue, calcoil blue, chrome yellow, ultramarine blue, Dupont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, Malachite green oxalate, Rose Bengal and the like.

For example, carbon black, nigrosine dye and the like are used as black toner, and pigments necessary for yellow, magenta and cyan toners include C.I. I. Pigment Blue 15: 3, C.I. I. Pigment Blue 1
5, C.I. I. Pigment Blue 15: 6, C.I. I. Pigment Blue 68, C.I. I. Pigment Red 48-
3, C.I. I. Pigment Red 122, C.I. I. Pigment Red 212, C.I. I. Pigment Red 57-
1, C.I. I. Pigment Yellow 17, C.I. I. Pigment Yellow 81, C.I. I. Pigment Yellow 154
And the like can be suitably used.

Examples of the other additives include charge control agents such as salicylic acid derivatives and azo metal complexes, and fixability improvers such as low molecular weight polyolefins and carnauba wax.

[0047]

Next, the present invention will be described based on examples, but embodiments of the present invention are not limited to these examples.

Example 1 << Preparation of Photoreceptor >> An undercoat layer made of a polyamide resin and having a thickness of 0.3 μm was provided on an aluminum drum having a diameter of 80 mmφ. Then, a mixed solution comprising 10 parts of polyvinyl butyral and 1600 parts of methyl ethyl ketone with respect to 30 parts of a perylene-based compound as a charge generating substance was prepared,
After dispersing the charge generating substance, it was coated on the undercoat layer and dried to form a charge generating layer having a thickness of 0.3 μm. Next, styryl compound 50 is used as a charge transport material.
0 parts, bisphenol Z type polycarbonate resin (Mw
= 8 × 10 ⁴ ) 600 parts and dichloromethane 3000
To prepare a mixed solution, and applied on the charge generation layer,
After drying, a charge transport layer having a thickness of 25 μm was formed. Further, a liquid is prepared by dispersing the fine particles shown in Table 1 below in 100 parts of a bisphenol Z-type polycarbonate resin (Mw = 8 × 10 ⁴ ) containing 100 parts of a styryl compound in the amounts shown in Table 1 below, and then coating and drying. A protective layer having high hardness was prepared on the surface.

[0049]

[Table 1]

The fine particles of the crosslinked styrene-acrylic resin are obtained by using divinylbenzene as a crosslinking agent, and adjusting the particle size and the degree of crosslinking using an emulsion polymerization method and a seed polymerization method. The degree of crosslinking of this product, that is, the insoluble content in the solvent, was obtained by measuring the insoluble content in methyl ethyl ketone. When no crosslinking agent is used, the insoluble content is 0%.

<< Example of Carrier Production >> Carrier-1 (the present invention) 0.5% by weight of MMA / nBA copolymer fine particles (primary particle diameter: 40 nm) on a Cu-Zn ferrite core having a volume average particle diameter of 60 μm After coating by force, a 2: 6: 2 copolymer of Structural Formula-1, 2 and methyl methacrylate was dissolved in acetone and spray-coated on the fluidized bed so as to have a coating amount of 2 wt% in the fluidized bed. .

Carrier-2 (invention) An 8: 2 copolymer of structural formula-4 and propylene hexafluoride was dissolved in DMF on a Cu-Zn ferrite core having a volume average particle diameter of 70 µm, and 2.0 wt% , And heat-treated.

Carrier-3 (Invention) Structural formula-3 was added to a magnetite core having a volume average particle diameter of 60 μm.
Polymer fine particles (primary particle size: 60 nm) were coated by 2.0 wt% mechanical impact force.

Carrier-4 (Comparative Example) A styrene and methyl methacrylate 6: 4 copolymer resin was dissolved in toluene on a Cu-Zn ferrite core, and sprayed so as to have a coating amount of 2.0 wt% in the fluidized bed. Coated.

<< Example of Toner Production >> Styrene acrylic resin 1
After adding 00 parts, 8 parts of carbon black, and 3 parts of low molecular weight polypropylene, the mixture was melted and kneaded, and pulverized and classified, to obtain colored particles having a volume average particle diameter of 8.3 μm. Then, 0.8 wt% of hydrophobic silica was added to the resultant to obtain a toner.

<< Example of Production of Developer >> Carrier-1 of the present invention,
Toners 2 and 3 were added with the above toner to produce Developers-1, 2, and 3 having a toner concentration of 6% by weight, respectively.

The above toner was added to Comparative Carrier-4 to prepare Comparative Developer-1 having a toner concentration of 6% by weight.

<< Evaluation >> An evaluation was performed using a copying machine having a mechanism in which a Konica U-Bix 3135 was modified and the transfer residual toner collected by the cleaning device was steadily returned to the developing device and reused (toner recycling process). Was.

In a high-temperature and high-humidity (33 ° C./80% RH) environment, 20,000 copies were actually photographed, and after standing overnight, image evaluation was performed the next morning to confirm the presence or absence of image blur.

The cleaning conditions include the angle θ formed by the holder and the photosensitive member in the configuration shown in FIG.
₁ is 22 °, and urethane rubber was used as a material constituting the cleaning blade itself. The rubber hardness was 65 °, the thickness was 2 mm, and the length outside the holder was 8 mm. Further, the pressing force against the photoconductor is 15 gf / cm.

The evaluation paper used was A4, and the results are shown in Table 2.

[0062]

[Table 2]

In Table 2, xx indicates that image blurring occurred on the entire surface, and x indicates partial occurrence.

As shown in the above results, the developer of the present invention did not show any blurring, which was a good result. However, in the comparative example, image blurring occurred and sufficient performance was not obtained.

[0065]

According to the present invention, even if a photoreceptor which is not easily worn is used, the effect of polishing the photoreceptor itself finely and uniformly can be provided, and an image can be stably formed for a long period of time. Thus, a possible image forming method can be provided.

[Brief description of the drawings]

FIG. 1 is a side view of a blade and a photoconductor.

FIG. 2 is a side view of another type of a blade and a photoconductor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cleaning blade 2 Photoconductor 3 Holder

Claims (3)

[Claims] An electrostatic latent image on an organic photoreceptor is contact-developed with a developer comprising a toner and a carrier to form a toner image, and the toner remaining on the photoreceptor after transferring the toner image to a transfer material is cleaned. An image forming method, wherein the carrier is a carrier containing a fluororesin, the photoreceptor is a photoreceptor containing fine particles, and the cleaning means is blade cleaning. 2. An electrostatic latent image on an organic photoreceptor is contact-developed with a developer comprising a toner and a carrier to form a toner image, and the toner remaining on the photoreceptor after transferring the toner image to a transfer material is cleaned. In the image forming method, the carrier is a carrier containing a fluororesin, the photoreceptor has a plurality of charge transport layers, and the weight average molecular weight of the resin contained in the charge transport layer on the outermost surface is other than that. An image forming method, wherein the photosensitive member is larger than the weight average molecular weight of the resin contained in the charge transport layer, and the cleaning means is blade cleaning. 3. The fluororesin is a homopolymer or a copolymer having a monomer unit represented by the following general formula (1), structural formula-4 or structural formula-5. Image forming method. Embedded image In the formula, R represents a hydrogen atom or a methyl group, and Rf represents an alkyl group or an allyl group in which at least one or more fluorine atoms have been substituted.