JP5641308B2 - Image forming apparatus and process cartridge for image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus and a process cartridge for an image forming apparatus applied to a copying machine, a facsimile, a laser printer, a direct digital plate making machine, and the like.

The electrophotographic image forming apparatus is applied to a copying machine, a laser printer, etc. As an electrophotographic photosensitive member (also simply referred to as a photosensitive member) to be used, inorganic photosensitive materials such as selenium, zinc oxide and cadmium sulfide are used. Since the days when the body was mainstream, nowadays, organic photoreceptors (OPC) that are more advantageous than inorganic photoreceptors are widely used due to reduced burden on the global environment, lower costs, and higher design flexibility. It has become.
This organophotoreceptor can be classified by layer structure. For example, (1) a photoconductive resin typified by polyvinylcarbazole (PVK) or PVK-TNF (2,4,7-trinitrofluorenone). A single layer type in which a charge transfer complex is provided on a conductive support; (2) a single layer type in which a pigment such as phthalocyanine or perylene is dispersed in a resin; ) Functional separation of the photosensitive layer provided on the conductive support into a charge generation layer (CGL) containing a charge generation material such as an azo pigment and a charge transport layer (CTL) containing a charge transport material such as triphenylamine Can be classified into the laminated type.

In the case of a stacked type, there are a structure in which a charge transport layer is provided on a charge generation layer and a structure opposite to this structure, the former being common and the latter being particularly referred to as a reverse layer.
In particular, the multilayer type is advantageous for high sensitivity, and in addition, there is a high degree of design freedom for high sensitivity and high durability. It is taken.

In recent years, the importance of manufacturing in consideration of global environmental conservation has increased, and electrophotographic photoreceptors are required to be converted from supply products (disposable consumables) as mechanical parts. For this purpose, it is necessary to extend the life of the electrophotographic photosensitive member. As a countermeasure, particularly in the case of an organic photosensitive member, a surface layer is formed on the photosensitive layer with a protective layer having excellent wear resistance. It is becoming common.
In addition, developing toners used in electrophotography are advantageous in improving the reduction of the global environmental burden during toner production, low power consumption due to low-temperature fixing, and high image quality. The use of toner having a particle size (generally, 6 μm or less) is becoming mainstream.

On the other hand, the toner remaining on the photoconductor after the transfer process is scraped by bringing the edge of the cleaning blade made of an elastic material such as rubber into pressure contact with the photoconductor surface in a direction opposite to the rotation direction, so-called counter direction. It is widely known that it is configured to drop.
In terms of removing toner from the photoreceptor, it becomes more difficult as the toner particle size becomes smaller. In particular, in the case of cleaning with a cleaning blade, the edge tends to slip through as the toner particle size becomes smaller.

As a toner for solving these problems, a method is proposed in which silica fine particles that have been subjected to a hydrophobic treatment are attached to the surface of the toner base particles, and the adhesion between the photoconductor and the toner is reduced to improve the cleaning property. (Patent Document 1).
As the cleaning blade, a rubber strip having a specific resilience and rubber hardness (JIS-A hardness) and cut to a width of 1 to 5 mm (sheet shape) is made of aluminum or iron. The thing attached to the plate-shaped support base of this is proposed (for example, refer patent documents 2-4).

Although these techniques improve the cleaning performance of the toner, when the silica added to the toner is detached and separated from the toner and adheres to the surface of the photoreceptor, the adhering matter has a very small particle size. However, this cleaning means has a problem that cleaning becomes difficult and remains on the surface of the photosensitive member and is fixed by blade pressure and frictional heat, so-called filming occurs.
In particular, when a surface protective layer is provided on the photoconductor, the amount of wear of the photoconductor is reduced, making it more difficult to remove. Therefore, silica and toner components start from silica particles adhering to repeated use. It has the problem that it adheres to the top and leads to the generation of abnormal images that appear in the image. It has a photoconductor with high wear resistance and can suppress abnormal images for a long time. There is a need for a combined image forming apparatus.

As another means for improving the cleaning ability, there is a method using a cleaning means using a cleaning blade and a cleaning brush in combination (for example, see Patent Documents 5 to 9).
For the material of the brush, nylon-based, polyester-based, acrylic-based fiber, carbon fiber, or the like is used. In the case of a cleaning means that uses a cleaning blade and a cleaning brush in combination, the cleaning brush has a function of forcibly removing foreign matters that are difficult to remove with the cleaning blade, but when a surface protective layer is provided on the photoreceptor, Since the outermost surface of the photoreceptor cannot be scraped, the cleaning brush removal effect could not be obtained sufficiently.

  In view of the above circumstances, an object of the present invention is to suppress adhesion to a photoconductor caused by the action of silica used as an external toner additive using a highly durable photoconductor having high wear resistance, and to achieve good resolution. An image forming apparatus capable of maintaining a high image quality, and a process cartridge used therefor.

The problem is that (1) “an electrophotographic photosensitive member in which at least a photosensitive layer and a surface protective layer are provided on a conductive substrate, a charging means for charging the surface of the electrophotographic photosensitive member, Image exposure means for forming an electrostatic latent image, development means for developing the electrostatic latent image with toner, transfer means for transferring the developed toner image, and cleaning means for cleaning the surface of the electrophotographic photoreceptor. In the image forming apparatus, the toner contains at least a binder resin and a colorant, and is formed by attaching at least one kind of hydrophobized silica fine particles to the surface of the toner base particles. , and the and the cleaning means, rotatable Cree that composition to a fabric flocked with conductive fibers comprising the adsorbent and the binder resin is wound on the core metal is impregnated The image forming apparatus characterized in that comprises a Nguburashi. "
(2) “ The image forming apparatus according to (1), wherein the adsorbent is at least one of zeolite, silica gel, and acrylic particles ”.
Further, the above-mentioned problems are solved by (3) “ electrophotographic photoreceptor in which at least a photosensitive layer and a surface protective layer are provided on a conductive substrate, a charging means for charging the surface of the electrophotographic photoreceptor, Image exposing means for forming an electrostatic latent image by exposure; developing means for developing the electrostatic latent image with toner; transferring means for transferring the developed toner image; and cleaning means for cleaning the surface of the electrophotographic photoreceptor. An image forming apparatus comprising at least a toner, wherein the toner contains at least a binder resin and a colorant, and at least one or more types of silica fine particles subjected to hydrophobic treatment are attached to the surface of the toner base particles. are those comprising Te, and the cleaning means, was impregnated at least zeolite, silica gel, any one or more of the adsorbents and the binder resin of the acrylic particles The image forming apparatus characterized in that with a leaning brush. "
(4) “The image forming apparatus according to (2) or (3), wherein the silica gel is B-type silica gel”,
(5) In any one of (1) to (4), the primary average particle diameter of at least one kind of silica fine particles to be hydrophobicized attached to the toner surface is 100 to 200 nm. Image forming apparatus ",
(6) “Image formation according to any one of (1) to (5), wherein the surface protective layer of the electrophotographic photoreceptor is formed by polymerizing at least a trifunctional or higher-functional radical polymerizable monomer. Achieved by "device".
In addition, the above-mentioned problem is (7) of the present invention “Containing at least one electrophotographic photosensitive member having a surface protective layer, at least a binder resin and a colorant, and at least one or more types of hydrophobic particles on the surface of the toner base particles. A developing means for developing with a toner to which silica fine particles that have been subjected to a chemical treatment are attached, and a cleaning means provided with a cleaning brush impregnated with a composition containing at least an adsorbent and a binder resin, This is achieved by a process cartridge characterized by being detachable from the image forming apparatus main body according to any one of (1) to (6).

  According to the present invention, an electrophotographic photosensitive member having a surface protective layer, and a toner having at least one kind of hydrophobized silica fine particles attached to the surface of toner base particles are used for cleaning. By using a cleaning brush impregnated with a composition containing at least an adsorbent and a binder resin as a means, it is possible to prevent silica adhesion in advance and maintain high image quality with good resolution. A forming apparatus and a process cartridge used therefor can be provided.

FIG. 2 is a schematic diagram illustrating a configuration of a cleaning unit in the image forming apparatus of the present invention. It is a cross-sectional schematic diagram of a cleaning brush used in the image forming apparatus of the present invention. FIG. 2 is a schematic cross-sectional view of a photoreceptor having a surface protective layer excellent in abrasion resistance used in the image forming apparatus of the present invention. 1 is a schematic view for explaining an image forming method and an image forming apparatus of the present invention. It is the schematic of the example of the process cartridge of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing a characteristic portion of the present invention, showing an example of a state in which a cleaning brush acts on a photosensitive member.

In FIG. 1, a photoconductor (31) having a surface protective layer with excellent wear resistance (hereinafter referred to as photoconductor (31)) rotates in the direction of the arrow (A), and the adsorbent and the binder resin are impregnated. The cleaning brush (32) (hereinafter referred to as cleaning brush (32)) rotates in the direction of arrow (B).
The cleaning blade (35) is held and fixed to the holder (36), and its edge is pressed against the photoconductor (31) with a predetermined pressure in a so-called counter direction opposite to the rotation direction of the photoconductor (31). .
The cleaning brush (32) is provided so as to form a brush nip portion (37) with the photoreceptor (31), and a predetermined bias is applied to the metal core (33) from a power source (not shown). It may be grounded or grounded.

The toner (38) remaining without being transferred from the surface of the photoreceptor to the transfer medium such as transfer paper by the transfer means is electrically cleaned by the action of a bias applied to the core metal (33) at the brush nip portion (37). It moves to the bristle part of a brush (32).
Further, a part of the toner (38) is mechanically removed from the photoreceptor (31) by the rotation of the cleaning brush (32). In this way, the toner (38) can be effectively removed regardless of its polarity and amount by electrical and mechanical action.

  In the present invention, when a cleaning brush impregnated with a composition containing an adsorbent and a binder resin is used, when the silica, which is a toner external additive, is released from the toner in combination with the toner removal effect, the silica is photosensitive. It becomes possible to suppress adhering to a body. This adhesion phenomenon of silica occurs particularly prominently when a surface protective layer is provided on the photoreceptor. The reason for this is not clear, but when a surface protective layer is provided on the photoconductor, the wear resistance of the photoconductor surface is greatly improved, so that the discharge products generated during charging become difficult to be removed from the photoconductor. Silica fine particles (hereinafter referred to as hydrophobic silica) in which moisture is adsorbed on the photoconductor and the adsorbed water is hydrophobized by absorbing the product water or the paper powder of the transfer paper adhering to the photoconductor. It is also expected that silica adheres by bonding with hydroxyl groups slightly present on the surface. Accordingly, the adsorbing material impregnated in the cleaning brush can also remove the adsorbed moisture adhering to the surface of the photoreceptor (31) in the same manner as the toner, so that it is contained in a small amount in the hydrophobic silica of the toner external additive. It is possible to avoid the surface hydroxyl group from strongly adhering to the photoconductor through the adsorbed water adhering to the photoconductor.

The cleaning brush (32) bounces off the toner (38) attached by the flicker (34) that has digged into the cleaning brush (32), and collects the toner (38) in a toner recovery unit (not shown).
When the cleaning brush is used repeatedly, the cleaned toner accumulates in (between) the brush fibers. Therefore, the flicker is installed to strike the brush to remove the accumulated toner from the brush. It is.
The rotation direction (B) of the cleaning brush (32) is set to the rotation direction A with respect to the rotation direction A of the photoconductor (31), and the hair near the tip of the cleaning brush (32) has a speed relative to the photoconductor (31). It is effective to rotate with a difference.

FIG. 2 is a schematic cross-sectional view of an example of a cleaning brush impregnated with an adsorbent and a binder resin.
A method for manufacturing a cleaning brush will be described as an example with reference to FIGS.
After the conductive fiber (22) is planted on the base fabric (21) so that the tip is looped and a brush is formed, the adsorbent is dissolved in the solution in which the binder resin dissolves on the back side of the base fabric (21). The dispersed paint is applied to form the adsorbent-containing resin layer (23), and the base fabric (21) is impregnated with the adsorbent-containing resin.
An adsorbent-containing resin layer (23) is formed on the back side of the base fabric (21).
When this adsorbent-containing resin layer forming liquid is applied to the back side of the base fabric (21), the adsorbent-containing resin liquid is sucked up on the surface of the conductive fiber (22) by capillary action, and the conductive fiber (22). The entire surface is coated with the adsorbent-containing resin liquid.
Thereafter, the adsorbent-containing resin liquid is dried and held by heat.

Next, the base fabric (21) thus processed is cut into a predetermined size, and then bonded while being wound around a rotatable metal core (33) to produce a stiff adsorbent-containing resin-impregnated cleaning brush. The
According to the image forming apparatus in which the obtained cleaning brush is installed as one of the cleaning means, it is possible to remove the adsorbed water on the surface of the photoconductor as well as the toner adhering to the surface of the photoconductor (31). It is possible to prevent the hydrophobic silica used for the additive from adhering to the photoreceptor via the adsorbed water.

As the adsorbing material for impregnating the brush used for producing the cleaning brush in the present invention, any adsorbing material that can adsorb moisture can be used.
Examples of the adsorbent include activated carbon, silica gel, zeolite, alumina, acrylic particles, and the like. In particular, by using at least one of zeolite, silica gel, and acrylic particles, excellent moisture adsorption ability can be obtained.
Activated carbon has fine pores made by reacting with gas and chemicals at a high temperature using the main raw material as a carbon material, the fine pores form a large surface area, and can adsorb various substances on the surface.
Silica gel is made from dehydrated and dried silicate gel, and has a porous structure and a large surface area. There are A-type and B-type silica gels, but B-type silica gel has an excellent ability to absorb moisture especially under high humidity, and has a characteristic of releasing moisture absorption under low humidity environment. This makes it possible to maintain the ability to remove adsorbed water.

Zeolite is a crystal like crystal, mainly composed of aluminum and silicon. The crystals are very small and cannot be seen visually in shape or size. When enlarged, it can be confirmed that there are many pores called pores. More than 40 types of zeolite having this unique structure have been discovered in nature. An industrially produced product is called a synthetic zeolite. Synthetic zeolites have many types that are high in performance and are not found in natural zeolites, but their cost is a disadvantage. Artificial zeolite has emerged as the third zeolite. By treating materials that were considered waste such as coal ash, it is converted into a zeolite that is beneficial to the earth and mankind. Moreover, because of its low cost, it is a material that is currently attracting considerable attention.
In addition, zeolite has different molecules that can be adsorbed because the pore size changes depending on the crystal form and the type of cation. Therefore, effective removal is possible by selecting the crystal form and cation species according to the target substance. Crystal types include A type, X type, Y type, L type, mordenite type, ferrierite type, ZSM-5 type, beta type, and cation species include potassium, sodium, calcium, ammonium, hydrogen, etc. is there. Further, the adsorption ability and catalytic ability change depending on the ratio of aluminum and silicon constituting the zeolite, and the target substance can be efficiently removed by setting the optimum ratio. Among these various zeolites, the A type, the X type, and the Y type are particularly desirable because they exhibit particularly excellent adsorption ability.
Moreover, activated alumina is used as alumina, and a cross-linked acrylic resin is used as the acrylic resin constituting the acrylic particles.

The resin for brush impregnation is preferably a thermosetting resin or a photo-curing resin in order to prevent the occurrence of cracking and cracking due to friction with the photoreceptor, but the same effect can be expected with a thermoplastic resin.
For example, polystyrene, styrene / acrylonitrile copolymer, styrene / butadiene copolymer, styrene / maleic anhydride copolymer, polyester, polyvinyl, polyvinyl chloride, vinyl chloride / vinyl acetate copolymer, polyvinyl acetate, polychlorinated Thermoplastics such as vinylidene, polyarylate, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, acrylic resin, silicone resin, fluorine resin, epoxy resin, melamine resin, urethane resin, phenol resin, alkyd resin Or a curable resin can be mentioned.
Further, by using a polyamide resin having high water absorption, it is possible to obtain a higher effect of removing adsorbed water on the surface of the photosensitive member in combination with the water absorbing effect of the adsorbent, and good image formation can be obtained.

  The mass ratio of the adsorbent and the resin for impregnating the brush is desirably in the range of 30:70 to 95: 5, more preferably 40:60 to 90:10. If the resin ratio is too large, the adsorbent cannot be retained, and if the resin ratio is too small, a sufficient removal effect of adsorbed water cannot be obtained.

The dispersion solvent that can be used when preparing the coating liquid for forming the adsorbent-containing resin layer (23) is appropriately selected from the solubility of the resin used and the dispersibility of the adsorbent. For example, methyl ethyl ketone, acetone, methyl isobutyl ketone , Ketones such as cyclohexanone, ethers such as dioxane, tetrahydrofuran and ethyl cellosolve, aromatics such as toluene and xylene, halogens such as chlorobenzene and dichloromethane, esters such as ethyl acetate and butyl acetate, methanol and butanol Alcohols etc. can be mentioned.
These solvents can be used alone or in combination.

In order to prevent charging due to friction between the photosensitive member and the adsorbent-containing resin layer (23), a conductive material can be added to the adsorbent-containing resin liquid.
Conductive materials include metal fine particles such as graphite, nickel, copper and silver, metal oxides such as antimony-doped tin oxide (ATO), indium tin oxide (ITO), tin oxide and zinc antimonate, and activated carbon. Such conductive particles, conductive polymers, ion conductive antistatic agents, and the like can be used.

  The adsorbent-containing resin liquid is prepared by putting the adsorbent into the resin solution and dispersing it using a dispersing machine such as a ball mill. Moreover, you may disperse | distribute an adsorbent only with a solvent, and in that case, it produces by adding resin or a resin solution after dispersion | distribution. When adding a conductive material, you may disperse | distribute with an adsorbent or may add to the liquid after dispersion | distribution. In view of the coating properties and storage stability of the adsorbent-containing resin liquid, it is desirable that the adsorbent particle size in the dispersion be dispersed to 5 μm or less. It is also useful to preliminarily grind the adsorbent with a mixer before dispersion. is there.

In the schematic diagram of FIG. 2, the conductive fiber (22) is shown in which the hair is planted so that the tip has a loop shape. .
Moreover, as the conductive fiber (22), a synthetic fiber made of a resin such as nylon, polyester, styrene, or acrylic can be used.
The thickness of the conductive fiber (22) is preferably 1 to 3 denier and the length is preferably 2 to 8 mm. Moreover, the effect of obtaining a hair density of the conductive fibers (22) of 100,000 to 400,000 / inch ² can be particularly obtained.

Next, the electrophotographic photosensitive member used in the present invention will be described.
FIG. 3 is a schematic cross-sectional view of a photoconductor provided with a surface protective layer having excellent wear resistance.
In the photoreceptor shown in FIG. 3, a photosensitive layer (11) is provided on a conductive substrate (13), and a surface protective layer (12) having excellent wear resistance is provided on the outermost surface.
The photosensitive layer (11) may have a function-separated stacked structure of a charge generation layer (112) and a charge transport layer (113), or may further have an undercoat layer (111).
Moreover, the compound which has the charge transport function mentioned later may contain in the protective layer (12).

Examples of the conductive substrate (13) include those having a volume resistance of 10 ¹⁰ Ω · cm or less, such as metals such as aluminum, nickel, chromium, nichrome, copper, silver, gold, platinum, and iron, tin oxide, and oxidation. A film or cylindrical plastic or paper coated with an oxide such as indium or the like by vapor deposition or sputtering, or a plate made of aluminum, aluminum alloy, nickel, stainless steel, etc., and drawing ironing method, impact ironing. It is possible to use a pipe that has been surface-treated by cutting, superfinishing, polishing, or the like after being made into a raw pipe by a method such as a method, an extruded ironing method, an extruded drawing method, or a cutting method.

As the photosensitive layer (11) in the present invention, a laminate type photosensitive layer in which a charge generation layer (112) and a charge transport layer (113) are sequentially laminated is suitable.
Of the layers in the multilayer photoconductor, the charge generation layer (112) will be described first.
The charge generation layer (112) refers to a part of the laminated photosensitive layer and has a function of generating charges by exposure.
This layer is mainly composed of a charge generating substance among the contained compounds.
The charge generation layer (112) may use a binder resin as necessary.

As the charge generation material, inorganic materials and organic materials can be used.
Examples of inorganic materials include crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, selenium-arsenic compounds, and amorphous silicon.
In amorphous silicon, dangling bonds terminated with hydrogen atoms or halogen atoms, or doped with boron atoms, phosphorus atoms or the like are preferably used.

On the other hand, as the organic material, known materials can be used, for example, metal phthalocyanine such as titanyl phthalocyanine and chlorogallium phthalocyanine, metal-free phthalocyanine, azurenium salt pigment, squaric acid methine pigment, symmetric type having a carbazole skeleton. Or asymmetric azo pigments, symmetric or asymmetric azo pigments having a triphenylamine skeleton, symmetric or asymmetric azo pigments having a diphenylamine skeleton, symmetric or asymmetric azo pigments having a dibenzothiophene skeleton, fluorenone Symmetric or asymmetric azo pigments having a skeleton, symmetric or asymmetric azo pigments having an oxadiazole skeleton, symmetric or asymmetric azo pigments having a bis-stilbene skeleton, distyryl oxadiazole Symmetrical or asymmetrical azo pigments having a rating, symmetrical or asymmetrical azo pigments having a distyrylcarbazole skeleton, perylene pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane and triphenylmethane Examples thereof include pigments, benzoquinone and naphthoquinone pigments, cyanine and azomethine pigments, indigoid pigments, and bisbenzimidazole pigments.
Among these, metal phthalocyanines, symmetric or asymmetric azo pigments having a fluorenone skeleton, symmetric or asymmetric azo pigments having a triphenylamine skeleton, and perylene pigments have a high quantum efficiency of charge generation, and thus are suitable for the present invention. It is suitable as a material to be used.
These charge generation materials may be used alone or as a mixture of two or more.

Binder resins used as necessary for the charge generation layer (112) include polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, polyarylate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly -N-vinylcarbazole, polyacrylamide, etc. are mentioned.
Of these, polyvinyl butyral is often used and is useful.
These binder resins may be used alone or as a mixture of two or more.

The method for forming the charge generation layer (112) is roughly classified into a vacuum thin film preparation method and a casting method from a solution dispersion system.
Examples of the former method include a vacuum deposition method, a glow discharge decomposition method, an ion plating method, a sputtering method, a reactive sputtering method, and a CVD (chemical vapor deposition) method. Can be formed satisfactorily.
In order to provide the charge generation layer (112) by a casting method, the above-described inorganic or organic charge generation material is ball milled with a binder resin, if necessary, using a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, or butanone. The dispersion may be dispersed by an attritor, a sand mill, etc., and the dispersion may be diluted appropriately.

Among these solvents, methyl ethyl ketone, tetrahydrofuran, and cyclohexanone are preferable because they have a lower environmental impact than chlorobenzene, dichloromethane, toluene, and xylene.
The application can be performed by a dip coating method, a spray coating method, a bead coating method, or the like.
The film thickness of the charge generation layer (112) provided as described above is suitably about 0.01 to 5 μm, preferably 0.05 to 2 μm.

Next, the charge transport layer (113) will be described.
The charge transport layer (113) constitutes a part of the laminated photosensitive layer that functions to inject and transport charges generated in the charge generation layer and to neutralize the surface charge of the photoreceptor provided by charging. is there.
The main components of the charge transport layer (113) are a charge transport component and a binder component that binds the charge transport component. The charge transport layer (113) can be formed by dissolving or dispersing a mixture or copolymer mainly composed of a charge transport component and a binder component in an appropriate solvent, and applying and drying the mixture.
As the coating method, a dipping method, a spray coating method, a ring coating method, a roll coater method, a gravure coating method, a nozzle coating method, a screen printing method, or the like is employed.
The thickness of the charge transport layer (113) is practically about 15 to 40 μm, preferably about 15 to 30 μm, in order to ensure the required sensitivity and charging ability, and preferably about 15 to 30 μm. 25 μm or less is appropriate.

  Since the protective layer (12) is laminated on the upper layer of the charge transport layer (113), the thickness of the charge transport layer (113) in this configuration is that of the charge transport layer in consideration of film scraping in actual use. It is not necessary to design a thick film, and it is possible to reduce the thickness.

Examples of the dispersion solvent that can be used in preparing the charge transport layer (113) coating solution include ketones such as methyl ethyl ketone, acetone, methyl isobutyl ketone, and cyclohexanone, ethers such as dioxane, tetrahydrofuran, and ethyl cellosolve, toluene, Examples thereof include aromatics such as xylene, halogens such as chlorobenzene and dichloromethane, esters such as ethyl acetate and butyl acetate, and the like.
Of these, methyl ethyl ketone, tetrahydrofuran, and cyclohexanone are preferable because they have a lower environmental impact than chlorobenzene, dichloromethane, toluene, and xylene.
These solvents can be used alone or in combination.

Examples of the polymer compound that can be used as the binder component of the charge transport layer (113) include polystyrene, styrene / acrylonitrile copolymer, styrene / butadiene copolymer, styrene / maleic anhydride copolymer, polyester, and polyvinyl. , Polyvinyl chloride, vinyl chloride / vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, polyarylate, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, acrylic resin, silicone resin, fluorine Examples thereof include thermoplastic or thermosetting resins such as resins, epoxy resins, melamine resins, urethane resins, phenol resins, and alkyd resins.
Of these, polystyrene, polyester, polyarylate, and polycarbonate are useful because they have good charge transfer characteristics when used as a binder component of a charge transport component.

Further, since the charge transport layer (113) has a surface protective layer laminated thereon, the charge transport layer (113) is not required to have mechanical strength as compared with the conventional charge transport layer.
For this reason, a material such as polystyrene, which is highly transparent but has a low mechanical strength and is difficult to be applied by the prior art, can be effectively used as the binder component of the charge transport layer (113).
These polymer compounds can be used singly or as a mixture of two or more kinds, or as a copolymer composed of two or more kinds of these raw material monomers, and further copolymerized with a charge transport material.

The charge transport material includes a hole transport material and an electron transport material.
Examples of the electron transport material include chloroanil, bromanyl, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4 , 5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-tri Examples thereof include electron-accepting materials such as nitrodibenzothiophene-5,5-dioxide and benzoquinone derivatives.

Examples of hole transport materials include poly-N-vinylcarbazole and derivatives thereof, poly-γ-galvazolylethyl glutamate and derivatives thereof, pyrene-formaldehyde condensates and derivatives thereof, polyvinylpyrene, polyvinylphenanthrene, polysilane, oxazole derivatives, Oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triarylmethane derivatives, 9-styrylanthracene derivatives, pyrazolines Derivatives, divinylbenzene derivatives, hydrazine derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, bisstilbene derivatives, enamine derivatives, etc. Other known materials can be mentioned.
These charge transport materials may be used alone or in combination of two or more.

If necessary, the charge transport layer (113) may contain a low-molecular compound such as an antioxidant, a plasticizer, a lubricant, and an ultraviolet absorber and a leveling agent.
These compounds can be used alone or as a mixture of two or more.
When a low molecular weight compound and a leveling agent are used in combination, sensitivity deterioration often occurs.
For this reason, generally these usage-amounts are 0.1-20 mass parts with respect to 100 mass parts of resin contained in a charge transport layer, Preferably, the usage-amount of a leveling agent is 0.1-10 mass parts, About 0.001 to 0.1 parts by mass is appropriate.

Next, the surface protective layer (12, also simply referred to as a protective layer) will be described.
The surface protective layer is desirably formed by polymerizing at least a polymerizable compound. From the viewpoint of mechanical durability, a polymerizable compound having three or more polymerizable functional groups in the molecule is preferably used. In other words, by polymerizing a polymerizable compound having three or more functional groups, a three-dimensional network structure is developed, and a surface protection layer having a very high crosslink density and a high hardness and high elasticity is obtained. Abrasion resistance and scratch resistance are achieved. By providing the surface protective layer with a film thickness of 0.5 μm or more and 15 μm or less, more preferably 1 μm or more and 10 μm or less, cracks and film peeling do not occur and very high wear resistance is achieved. Is done. Examples of the cured resin include amino resin, urethane resin, epoxy resin, phenol resin, silicone resin, and acrylic resin. Among these, UV curable acrylic resins containing radically polymerizable monomers having at least three functional groups are particularly excellent in wear resistance and can be used favorably.

  Examples of the tri- or higher functional radical polymerizable monomer include trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate, trimethylolpropane alkylene-modified triacrylate, trimethylolpropane ethyleneoxy-modified (hereinafter EO-modified) triacrylate, trimethylol. Propane propyleneoxy modified (hereinafter PO modified) triacrylate, trimethylolpropane caprolactone modified triacrylate, trimethylolpropane alkylene modified trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate (PETTA), glycerol triacrylate, glycerol epichlorohydrin Modified (hereinafter ECH modified) triacrylate, glycerol EO Triacrylate, glycerol PO-modified triacrylate, tris (acryloxyethyl) isocyanurate, dipentaerythritol hexaacrylate (DPHA), dipentaerythritol caprolactone-modified hexaacrylate, dipentaerythritol hydroxypentaacrylate, alkylated dipentaerythritol pentaacrylate , Alkylated dipentaerythritol tetraacrylate, alkylated dipentaerythritol triacrylate, dimethylolpropane tetraacrylate (DTMPTA), pentaerythritol ethoxytetraacrylate, EO-modified triacrylate phosphate 2,2,5,5, -tetrahydroxy Methylcyclopentanone tetraacrylate and the like. It may be used in combination of two or more.

Further, in the formation of the surface protective layer of the present invention, in addition to the polymerizable compound, a charge transporting compound (with or without a polymerizable functional group does not matter, but has a polymerizable functional group from the viewpoint of mechanical durability). It is also possible to contain them. The charge transporting compound having a polymerizable functional group preferably has a smaller number of functional groups from the viewpoint of distortion of the cured resin structure and internal stress of the crosslinked surface layer, and a monofunctional charge transporting compound can be used favorably. .
When the surface protective layer is composed of a tri- or higher functional radical polymerizable compound having no charge transport structure and a monofunctional radical polymerizable compound having a charge transport structure, the trifunctional does not have a charge transport structure. The component ratio of the above radical-polymerizable compound is 20 to 80% by mass, preferably 30 to 70% by mass, based on the total amount of the protective layer. If the compound component is less than 20% by mass, the surface protective layer has a small three-dimensional cross-linking density, and it tends to be difficult to achieve a dramatic improvement in wear resistance as compared with the case of using a conventional thermoplastic binder resin. On the other hand, if it exceeds 80% by mass, the content of the charge transporting compound tends to decrease, and the electrical characteristics tend to deteriorate.

Dispersing solvents that can be used as the coating solvent for the surface protective layer (12) are ketones, ethers, aromatic compounds, halogen compounds, esters, and the like.
Of these, methyl ethyl ketone, tetrahydrofuran, and cyclohexanone are preferable because they have a lower environmental impact than chlorobenzene, dichloromethane, toluene, and xylene.

Moreover, the surface protective layer (12) in this invention may contain an inorganic filler.
Examples of the inorganic filler include titanium oxide, silica, tin oxide, alumina, zirconium oxide, indium oxide, silicon nitride, calcium oxide, zinc oxide, and barium sulfate.
These inorganic fillers may be surface-treated with an inorganic substance or an organic substance for reasons such as improving dispersibility.
Generally treated with a silane coupling agent as a water repellent treatment, treated with a fluorinated silane coupling agent, treated with a higher fatty acid, treated with an inorganic substance, treated with filler, alumina, zirconia, tin oxide, silica It has been known.

In general, these inorganic fillers are pulverized and dispersed, and then mixed with a surface protective layer coating solution.
The content of the inorganic filler in the protective layer is 3 to 50% by weight, preferably 5 to 30% by weight. The transparency of the glass is impaired.
If necessary, low-molecular compounds such as antioxidants, plasticizers, lubricants, ultraviolet absorbers, and leveling agents can be added.
These compounds can be used alone or as a mixture of two or more.
The amount of the low molecular compound used is 0.1 to 50 parts by weight, preferably 0.1 to 20 parts by weight, and the amount of the leveling agent used is 100 parts by weight of the resin component. About 0.001 to 5 parts by mass is appropriate.

As a method for forming such a protective layer (12), a dipping method, a spray coating method, a ring coating method, a roll coater method, a gravure coating method, a nozzle coating method, a screen printing method and the like are employed.
In particular, the spray coating method and the ring coating method are suitable because they are easy to ensure quality stability in production.

In the present invention, a polymerization initiator may be contained as required in order to allow the curing reaction to proceed efficiently.
Examples of the thermal polymerization initiator include 2,5-dimethylhexane-2,5-dihydroperoxide, dicumyl peroxide, benzoyl peroxide, t-butylcumyl peroxide, 2,5-dimethyl-2,5-di ( Peroxybenzoyl) hexyne-3, di-t-butyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, lauroyl peroxide, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) B) Peroxide-based initiators such as propane, azo-based compounds such as azobisisobutyronitrile, azobiscyclohexanecarbonitrile, methyl azobisisobutyrate, azobisisobutylamidine hydrochloride, 4,4′-azobis-4-cyanovaleric acid Initiators are mentioned.

  Examples of the photopolymerization initiator include diethoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 4- (2-hydroxyethoxy) phenyl- (2 -Hydroxy-2-propyl) ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2- Acetophenone-based or ketal-based photopolymerization initiators such as methyl-2-morpholino (4-methylthiophenyl) propan-1-one, 1-phenyl-1,2-propanedione-2- (o-ethoxycarbonyl) oxime, Benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl ether Benzoin ether photopolymerization initiators such as benzoin isopropyl ether, benzophenone, 4-hydroxybenzophenone, methyl o-benzoylbenzoate, 2-benzoylnaphthalene, 4-benzoylbiphenyl, 4-benzoylphenyl ether, acrylated benzophenone, Benzophenone photopolymerization initiators such as 1,4-benzoylbenzene, thioxanthones such as 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone Examples of photopolymerization initiators and other photopolymerization initiators include ethyl anthraquinone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoic acid. Phenylethoxyphosphine oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, bis (2,4-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, methylphenylglyoxyester, 9,10 -Phenanthrene, an acridine type compound, a triazine type compound, an imidazole type compound is mentioned.

Moreover, what has a photopolymerization acceleration effect can also be used individually or in combination with the said photoinitiator.
Examples thereof include triethanolamine, methyldiethanolamine, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, (2-dimethylamino) ethyl benzoate, 4,4′-dimethylaminobenzophenone, and the like.

These polymerization initiators may be used alone or in combination of two or more.
The content of the polymerization initiator is preferably 0.1 part by mass to 40 parts by mass, and more preferably 0.5 part by mass to 20 parts by mass with respect to 100 parts by mass of the total content having a polymerizable functional group.

As a method for forming such a protective layer (12), after applying by dipping method, spray coating method, ring coating method, roll coater method, gravure coating method, nozzle coating method, screen printing method, etc., it is cured by applying energy from the outside. And a method of forming the protective layer (12) is employed.
The external energy used at this time includes heat, light, radiation, etc., and is selected depending on the resin used.

The heat energy is applied by heating from the coating surface side or the support side using a gas such as air or nitrogen, steam, various heat media, infrared rays, or electromagnetic waves.
The heating temperature is preferably 100 ° C. or higher and 170 ° C. or lower. If it is less than 100 ° C., the reaction rate is slow and the curing reaction is not completely completed. On the other hand, at a temperature higher than 170 ° C., the curing reaction proceeds non-uniformly, and large distortion, a large number of unreacted residues, and reaction termination terminals are generated in the surface protective layer.
In order to advance the curing reaction uniformly, it is also effective to complete the reaction by heating at a relatively low temperature of less than 100 ° C. and then heating to 100 ° C. or more.

As the energy of light, UV irradiation light sources such as high-pressure mercury lamps and metal halide lamps, which mainly have an emission wavelength in ultraviolet light, can be used, but a visible light source can also be selected according to the absorption wavelength of radically polymerizable substances and photopolymerization initiators. Is possible.
Irradiation light amount is 50 mW / cm ² or more, preferably 1000 mW / cm ² or less. If it is less than 50 mW / cm ² , it takes time for the curing reaction. On the other hand, when the strength is higher than 1000 mW / cm ² , the reaction proceeds non-uniformly, and local flaws are generated on the surface of the protective layer (12), and many unreacted residues and reaction termination ends are generated.
In addition, internal stress increases due to rapid crosslinking, which causes cracks and film peeling.
Examples of radiation energy include those using electron beams.
Among these energies, those using heat and light energy are useful because of the ease of reaction rate control and the simplicity of the apparatus.

In addition, the photoreceptor (1) used in the image forming apparatus of the present invention can be appropriately provided with an undercoat layer (111) between the conductive substrate (13) and the photosensitive layer (11).
The undercoat layer (111) is generally composed mainly of a resin, but these resins are resistant to general organic solvents in view of applying a photosensitive layer thereon with a solvent. A highly soluble resin is desirable.
Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane, melamine resin, alkyd resin, melamine resin, and epoxy resin. And a curable resin that forms a three-dimensional network structure.

In addition, by adding fine powders such as metal oxides exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide, etc., or metal sulfides, metal nitrides, etc. as fillers in the undercoat layer, Furthermore, stable chargeability can be maintained.
These undercoat layers can be formed using an appropriate solvent and a coating method, and the film thickness is 0 to 10 μm, preferably 0.2 to 6 μm.

  The toner suitably used in the image forming apparatus of the present invention is obtained by attaching at least one or more types of silica fine particles subjected to a hydrophobic treatment to the surface of the toner base particles. The toner base particles used in the present invention can be kneaded and pulverized by melting and kneading a resin, pigment, charge control agent, and release agent, cooling and then pulverizing and classifying, but the particle size and shape are uniform. Therefore, it is more preferable to use those prepared using a polymerization toner method such as an emulsion polymerization method or a dissolution suspension method.

Hereinafter, as an example, a constituent material and a production method of a polyester polymerization toner will be specifically described.
<Polyester>
The polyester is obtained by a polycondensation reaction between a polyhydric alcohol compound and a polycarboxylic acid compound.
Examples of the polyhydric alcohol compound (PO) include dihydric alcohol (DIO) and trihydric or higher polyhydric alcohol (TO). (DIO) alone or a mixture of (DIO) and a small amount of (TO) preferable.

Examples of the dihydric alcohol (DIO) include alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.), alkylene ether glycol (diethylene glycol). , Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.), alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.), bisphenols (bisphenol A, bisphenol) F, bisphenol S, etc.), alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol, Alkylene oxide bisphenol (ethylene oxide, propylene oxide, butylene oxide) adducts.
Of these, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is combined use with.

  As trihydric or higher polyhydric alcohol (TO), trihydric or higher polyhydric aliphatic alcohol (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.), trihydric or higher phenols (Trisphenol PA, phenol novolak, cresol novolak, etc.), alkylene oxide adducts of the above trivalent or higher polyphenols, and the like.

Examples of the polyvalent carboxylic acid (PC) include divalent carboxylic acid (DIC) and trivalent or higher polyvalent carboxylic acid (TC). (DIC) alone and (DIC) with a small amount of (TC) Mixtures are preferred.
Divalent carboxylic acids (DIC) include alkylene dicarboxylic acids (succinic acid, adipic acid, sebacic acid, etc.), alkenylene dicarboxylic acids (maleic acid, fumaric acid, etc.), aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid) , Naphthalenedicarboxylic acid, etc.). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms.
Examples of the trivalent or higher polyvalent carboxylic acid (TC) include aromatic polyvalent carboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid).
In addition, as polyhydric carboxylic acid (PC), you may make it react with polyhydric alcohol (PO) using the above-mentioned acid anhydride or lower alkyl ester (Methyl ester, ethyl ester, isopropyl ester, etc.).

The ratio of the polyhydric alcohol (PO) to the polycarboxylic acid (PC) is usually 2/1 to 1/1, preferably as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. Is 1.5 / 1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.
The polycondensation reaction of polyhydric alcohol (PO) and polycarboxylic acid (PC) is heated to 150-280 ° C in the presence of a known esterification catalyst such as tetrabutoxy titanate, dibutyltin oxide, etc. The produced water is distilled off to obtain a polyester having a hydroxyl group.

  The hydroxyl value of the polyester is preferably 5 mgKOH / g or more, and the acid value of the polyester is usually 1 to 30 mgKOH / g, preferably 5 to 25 mgKOH / g. By giving an acid value, it tends to be negatively charged, and furthermore, when fixing to a recording paper, the affinity between the recording paper and the toner is good and the low-temperature fixability is improved. However, when the acid value exceeds 30 mgKOH / g, there is a tendency to deteriorate with respect to the stability of charging, particularly environmental fluctuation.

  The weight average molecular weight is 10,000 to 400,000, preferably 20,000 to 200,000. A weight average molecular weight of less than 10,000 is not preferable because offset resistance deteriorates. On the other hand, if it exceeds 400,000, the low-temperature fixability is deteriorated.

  The polyester preferably contains a urea-modified polyester in addition to the unmodified polyester obtained by the above polycondensation reaction. The urea-modified polyester is obtained by reacting a terminal carboxyl group or hydroxyl group of the polyester obtained by the above polycondensation reaction with a polyvalent isocyanate compound (PIC) to obtain a polyester prepolymer (A) having an isocyanate group. It is obtained by cross-linking and / or extending the molecular chain by the reaction of the amine with amines.

  Examples of the polyvalent isocyanate compound (PIC) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.), alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.) ), Aromatic diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.), araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.), isocyanates, phenol derivatives, oximes, Examples thereof include those blocked with caprolactam and the like and combinations of two or more thereof.

  The ratio of the polyvalent isocyanate compound (PIC) is usually 5/1 to 1/1, preferably as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. 4/1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. When the molar ratio of [NCO] is less than 1, when a urea-modified polyester is used, the urea content in the ester is lowered and hot offset resistance is deteriorated.

  The content of the polyvalent isocyanate compound (PIC) component in the polyester prepolymer (A) having an isocyanate group is usually 0.5 to 40 wt%, preferably 1 to 30 wt%, more preferably 2 to 20 wt%. . If it is less than 0.5 wt%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40 wt%, the low-temperature fixability deteriorates.

  The number of isocyanate groups contained per molecule in the polyester prepolymer (A) having isocyanate groups is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2.5 on average. It is. If it is less than 1 per molecule, the molecular weight of the urea-modified polyester will be low, and the hot offset resistance will deteriorate.

Next, as amines (B) to be reacted with the polyester prepolymer (A), a divalent amine compound (B1), a trivalent or higher polyvalent amine compound (B2), an amino alcohol (B3), an amino mercaptan (B4) ), Amino acid (B5), and amino acids B1 to B5 blocked (B6).
Examples of the divalent amine compound (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.) and alicyclic diamines (4,4′-diamino-3,3′-dimethyldicyclohexyl). Methane, diamine cyclohexane, isophorone diamine, etc.) and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.) and the like. Examples of the trivalent or higher polyvalent amine compound (B2) include diethylenetriamine and triethylenetetramine.

  Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid. Examples of the B1 to B5 amino group blocked (B6) include ketimine compounds and oxazolidine compounds obtained from the amines of B1 to B5 and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Among these amines (B), preferred are B1 and a mixture of B1 and a small amount of B2.

  The ratio of amines (B) is equivalent to the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the polyester prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). Is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2. If [NCO] / [NHx] is more than 2 or less than 1/2, the molecular weight of the urea-modified polyester is lowered, and the hot offset resistance is deteriorated.

  The urea-modified polyester may contain a urethane bond together with a urea bond. The molar ratio of the urea bond content to the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance is deteriorated.

  The urea-modified polyester is produced by a one-shot method or the like. Polyhydric alcohol (PO) and polyvalent carboxylic acid (PC) are heated to 150-280 ° C. in the presence of a known esterification catalyst such as tetrabutoxytitanate, dibutyltin oxide, etc., and water generated while reducing the pressure as necessary. Distill off to obtain a polyester having a hydroxyl group. Subsequently, at 40-140 degreeC, this is made to react with polyvalent isocyanate (PIC), and the polyester prepolymer (A) which has an isocyanate group is obtained. Further, this (A) is reacted with amines (B) at 0 to 140 ° C. to obtain a urea-modified polyester.

  When reacting the above (PIC) and when reacting (A) and (B), a solvent may be used if necessary. For example, aromatic solvents (toluene, xylene, etc.), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), esters (ethyl acetate, etc.); amides (dimethylformamide, dimethylacetamide, etc.), and ethers (tetrahydrofuran, etc.) A solvent inert to isocyanate (PIC) such as) can be used.

  In addition, in the crosslinking and / or extension reaction between the polyester prepolymer (A) and the amines (B), a reaction terminator can be used as necessary to adjust the molecular weight of the resulting urea-modified polyester. Examples of the reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).

  The weight average molecular weight of the urea-modified polyester is usually 10,000 or more, preferably 20,000 to 10,000,000, and more preferably 30,000 to 1,000,000. If it is less than 10,000, the hot offset resistance deteriorates. The number average molecular weight of the urea-modified polyester or the like is not particularly limited when the above-mentioned unmodified polyester is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight.

  When the urea-modified polyester is used alone, its number average molecular weight is usually 2000-15000, preferably 2000-10000, more preferably 2000-8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color apparatus are deteriorated.

  By using the unmodified polyester and the urea-modified polyester in combination, the low-temperature fixability and the glossiness when used in a full-color image forming apparatus are improved. Therefore, it is preferable to use the urea-modified polyester alone. The unmodified polyester may include a polyester modified with a chemical bond other than a urea bond.

The unmodified polyester and the urea-modified polyester are preferably at least partially compatible with each other in terms of low-temperature fixability and hot offset resistance. Therefore, it is preferable that the unmodified polyester and the urea-modified polyester have a similar composition.
The mass ratio of unmodified polyester and urea-modified polyester is usually 20/80 to 95/5, preferably 70/30 to 95/5, more preferably 75/25 to 95/5, and particularly preferably 80 /. 20-93 / 7. When the mass ratio of the urea-modified polyester is less than 5%, the hot offset resistance is deteriorated, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

The glass transition point (Tg) of the binder resin containing unmodified polyester and urea-modified polyester is usually 45 to 65 ° C, preferably 45 to 60 ° C. If it is less than 45 ° C., the heat resistance of the toner deteriorates, and if it exceeds 65 ° C., the low-temperature fixability becomes insufficient.
In addition, since the urea-modified polyester is likely to be present on the surface of the obtained toner base particles, the heat-resistant storage stability tends to be good even when the glass transition point is low as compared with known polyester-based toners.

<Colorant>
As the colorant, all known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher , Yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Vulcan fast yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Phi Sayred, Parachlor Ortonito Aniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine B, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R , Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thio Indigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red Polyazo Red, Chrome Vermillion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), indigo, ultramarine blue, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Lid Russian nin green, anthraquinone green, titanium oxide, zinc white, litbon and mixtures thereof can be used.
The content of the colorant is usually 1 to 15% by mass, preferably 3 to 10% by mass with respect to the toner.

  The colorant can also be used as a master batch combined with a resin. As a binder resin to be kneaded together with the production of the master batch or the master batch, a polymer of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyl toluene or the like, or a copolymer of these and a vinyl compound, Polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, fat Aromatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, paraffin waxes and the like can be used, and these can be used alone or in combination.

<Charge control agent>
Any known charge control agent can be used. For example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus Simple substance or compound, tungsten simple substance or compound, fluorine-based activator, salicylic acid metal salt, metal salt of salicylic acid derivative, and the like.

Specifically, Bontron 03 of a nigrosine dye, Bontron P-51 of a quaternary ammonium salt, Bontron S-34 of a metal-containing azo dye, E-82 of an oxynaphthoic acid metal complex, E-84 of a salicylic acid metal complex , Phenolic condensate E-89 (above, Orient Chemical Industries, Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, Hodogaya Chemical Co., Ltd.), quaternary ammonium salt copy Charge PSY VP2038, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (Nippon Carlit) Manufactured), copper phthalocyanine, perylene, quinacridone, azo series Fee, a sulfonic acid group, a carboxyl group, and polymer compounds having a functional group such as quaternary ammonium salts.
Of these, substances that control the negative polarity of the toner are particularly preferably used.

  The amount of charge control agent used is determined by the type of binder resin, the presence or absence of additives used as necessary, and the toner production method including the dispersion method, and is not uniquely limited. Preferably, it is used in the range of 0.1 to 10 parts by mass with respect to 100 parts by mass of the binder resin. Preferably, it shall be the range of 0.2-5 mass parts. When the amount exceeds 10 parts by mass, the chargeability of the toner is too high, the effect of the charge control agent is reduced, the electrostatic attractive force with the developing roller is increased, the developer fluidity is lowered, and the image density is lowered. Invite.

<Release agent>
As a release agent, a low melting point wax having a melting point of 50 to 120 ° C. works more effectively as a release agent in the dispersion with the binder resin between the fixing roller and the toner interface. The effect on high temperature offset is exhibited without applying a release agent such as oil.

Examples of such a wax component include the following.
Waxes and waxes include plant waxes such as carnauba wax, cotton wax, wood wax, rice wax, animal waxes such as beeswax and lanolin, mineral waxes such as ozokerite and cercin, and paraffin, microcrystalline, and petrolatum. And petroleum wax.
In addition to these natural waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax and polyethylene wax, and synthetic waxes such as esters, ketones, and ethers can be used.
Furthermore, 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide, fatty acid amides such as chlorinated hydrocarbons, and low molecular weight crystalline polymer resins, poly-n-stearyl methacrylate, poly-n- A crystalline polymer having a long alkyl group in the side chain such as a homopolymer or copolymer of polyacrylate such as lauryl methacrylate (for example, a copolymer of n-stearyl acrylate-ethyl methacrylate, etc.) can also be applied.

  The charge control agent and the release agent can be melt-kneaded together with the master batch and the binder resin, and of course, they may be added when dissolved and dispersed in the organic solvent.

<Manufacturing method>
Next, a toner manufacturing method will be described. In the following, specific examples are shown, and the toner manufacturing method applied to the present invention is not limited to the following.

(A) A toner material solution is prepared by dispersing a colorant, unmodified polyester, a polyester prepolymer having an isocyanate group, and a release agent in an organic solvent.
The organic solvent is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal after toner base particle formation. Specifically, toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, Methyl isobutyl ketone or the like can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform and carbon tetrachloride are suitable.
The usage-amount of an organic solvent is 0-300 mass parts normally with respect to 100 mass parts of polyester prepolymers, Preferably it is 0-100 mass parts, More preferably, it is 25-70 mass parts.

(B) The toner material liquid is emulsified in an aqueous medium in the presence of a surfactant and resin fine particles.
The aqueous medium may be water alone or an organic solvent such as alcohol (methanol, isopropyl alcohol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.). It may be included.
The amount of the aqueous medium used relative to 100 parts by mass of the toner material liquid is usually 50 to 2000 parts by mass, preferably 100 to 1000 parts by mass. If the amount is less than 50 parts by mass, the dispersion state of the toner material liquid is poor, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 20000 parts by mass, it is not economical.

Further, in order to improve the dispersion in the aqueous medium, a dispersant such as a surfactant and resin fine particles is appropriately added.
As surfactants, anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt types such as imidazoline, Quaternary ammonium salt type cationic surfactants such as alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, pyridinium salts, alkylisoquinolinium salts, benzethonium chloride, fatty acid amide derivatives, polyhydric alcohols Nonionic surfactants such as derivatives, for example, amphoteric surfactants such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl-N, N-dimethylammonium betaine It is below.

Moreover, the effect can be exhibited in a very small amount by using a surfactant having a fluoroalkyl group. Suitable anionic surfactants having a fluoroalkyl group include fluoroalkylcarboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [ω-fluoroalkyl (C6-C11). Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [ω-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carboxylic acid And metal salts, perfluoroalkyl carboxylic acids (C7 to C13) and metal salts thereof, perfluoroalkyl (C4 to C12) sulfonic acids and metal salts thereof, perfluorooctane sulfonic acid diethanolamide, N-propyl-N- (2 -Hydroxyethyl) perfluorooctane Sulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. .
Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101. DS-102 (manufactured by Daikin Industries, Ltd.), Megafac F-110, F-120, F-113, F-191, F-812, F-833 (manufactured by Dainippon Ink, Inc.), Xtop EF-102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fgentent F-100, F150 (manufactured by Neos).

  In addition, examples of the cationic surfactant include aliphatic quaternary ammonium salts such as aliphatic primary, secondary or tertiary amine acids having a fluoroalkyl group, and perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salts. , Benzalkonium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (manufactured by Asahi Glass), Florard FC-135 (manufactured by Sumitomo 3M), Unidyne DS-202 (Daikin Industries) Manufactured), MegaFuck F-150, F-824 (manufactured by Dainippon Ink, Inc.), X-Top EF-132 (manufactured by Tochem Products), and Footgent F-300 (manufactured by Neos).

The resin fine particles are added to stabilize the toner base particles formed in the aqueous medium. For this reason, it is preferable to add so that the coverage existing on the surface of the toner base particles is in the range of 10 to 90%.
For example, polymethyl methacrylate fine particles 1 μm and 3 μm, polystyrene fine particles 0.5 μm and 2 μm, poly (styrene-acrylonitrile) fine particles 1 μm, trade names are PB-200H (manufactured by Kao), SGP (manufactured by Soken), Techno Examples include polymer SB (manufactured by Sekisui Chemical Co., Ltd.), SGP-3G (manufactured by Sokensha), and micropearl (manufactured by Sekisui Fine Chemical Co., Ltd.).

  In addition, inorganic compound dispersants such as tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, and hydroxyapatite can also be used.

As a dispersant that can be used in combination with the above resin fine particles and inorganic compound dispersant, the dispersed droplets may be stabilized by a polymer protective colloid.
For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride and other (meth) acrylic monomers containing hydroxyl groups Bodies such as acrylic acid-β-hydroxyethyl, methacrylic acid-β-hydroxyethyl, acrylic acid-β-hydroxypropyl, methacrylic acid-β-hydroxypropyl, acrylic acid-γ-hydroxypropyl, methacrylic acid-γ-hydroxy Propyl, acrylic acid-3-chloro-2-hydroxypropyl, methacrylic acid-3-chloro-2-hydroxypropyl, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate Acid esters, N-methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, etc., or compounds containing vinyl alcohol and a carboxyl group Esters such as vinyl acetate, vinyl propionate, vinyl butyrate, acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, vinyl pyridine, vinyl pyrrolidone, vinyl imidazole , Nitrogen-containing compounds such as ethyleneimine, or homopolymers or copolymers such as those having a heterocyclic ring thereof, polyoxyethylene, polyoxypropylene , Polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxyethylene nonyl Polyoxyethylenes such as phenyl esters, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.

The dispersion method is not particularly limited, and any of known methods such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, and an ultrasonic wave can be applied.
Among these, the high-speed shearing method is preferable in order to make the particle size of the dispersion 2 to 20 μm. When a high-speed shearing disperser is used, the rotational speed is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 40 to 98 ° C.

(C) At the same time as the preparation of the emulsion, the amines (B) are added to cause a reaction with the polyester prepolymer (A) having an isocyanate group.
This reaction involves molecular chain crosslinking and / or elongation. The reaction time is selected depending on the reactivity between the isocyanate group structure of the polyester prepolymer (A) and the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 24 hours. The reaction temperature is generally 0 to 150 ° C, preferably 40 to 98 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.

(D) After completion of the above reaction, the organic solvent is removed from the emulsified dispersion (reactant), washed and dried to obtain toner base particles.
In order to remove the organic solvent, the temperature of the entire system is gradually raised in a laminar stirring state, and after giving strong stirring in a certain temperature range, the solvent base is removed to produce spindle-shaped toner base particles. .
Further, when an acid such as calcium phosphate salt or an alkali-soluble material is used as the dispersion stabilizer, the calcium phosphate salt is dissolved from the toner base particles by a method such as washing with water after dissolving the calcium phosphate salt with an acid such as hydrochloric acid. Remove. It can also be removed by an operation such as degradation with an enzyme.

(E) In the present invention, hydrophobic silica is added to the toner base particles obtained as described above by mixing and stirring to obtain a toner.
At least one of the external additives added to the toner surface is preferably hydrophobic silica having a primary average particle size of 100 to 200 nm. When the primary average particle size is less than 100 nm, the toner cleaning property is deteriorated and a streak-like abnormal image is generated. Will occur.
Hydrophobic silica means a surface treatment to increase hydrophobicity and prevent deterioration of flow characteristics and charging characteristics even under high humidity. As a surface treatment agent, for example, a silane coupling agent, Examples include silylating agents, silane coupling agents having a fluorinated alkyl group, organic titanate coupling agents, aluminum coupling agents, silicone oils, and modified silicone oils.

Furthermore, in addition to the hydrophobic silica, other external additives can be used in combination. Examples of the inorganic fine particles include silica, alumina, titania, barium titanate, magnesium titanate, calcium titanate, and titanic acid. Strontium, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, carbonized Examples thereof include silicon and silicon nitride.
The content of the external additive in the toner is preferably 0.01 to 5.0% by mass, and more preferably 0.01 to 2.0% by mass.
The proportion of the hydrophobic silica in the external additive is preferably 60% or more, and the proportion of the hydrophobic silica having a primary average particle size of 100 to 200 nm in the hydrophobic silica is preferably 20 to 70%. .
The primary average particle diameter in hydrophobic silica can be determined by measuring the diameter of 50 particles from an observation image using an electrophotographic microscope such as SEM or TEM and deriving the average value.
The degree of hydrophobicity is preferably 50 to 90%. When the degree of hydrophobicity is less than 50%, the toner charge leakage under high temperature and high humidity increases, and toner scattering and photoreceptor fogging are likely to occur. On the other hand, if the degree of hydrophobicity is greater than 90%, the toner tends to be excessively charged under low temperature and low humidity, which may cause image density defects. Further, the presence of excess hydrophobizing agent has an adverse effect such as poor toner fluidity.

The method for measuring the degree of hydrophobicity is shown below.
(Measurement method of degree of hydrophobicity)
Add 50 ml of water to a 200 ml beaker and add 0.2 g of external additive fine particles. Then, while gently stirring with a magnetic stirrer, methanol was added from the burette whose tip was immersed in water at the time of dropping, and the floating external additive fine particles began to sink. Read and calculate from the following formula.
Hydrophobicity (%)
= (Ml of methanol dropped / (50 + ml of methanol dropped)) × 100

  Next, the image forming apparatus of the present invention will be described. The image forming apparatus of the present invention comprises at least an electrophotographic photosensitive member, a charging unit, an exposure unit, a developing unit, a transfer unit, a cleaning unit, and a fixing unit, and further appropriately selected as necessary. The other means, for example, a static elimination means, a recycling means, a control means, etc. are provided. The charging unit and the exposure unit may be collectively referred to as an electrostatic latent image forming unit.

(Electrostatic latent image forming means)
The electrostatic latent image forming unit is a unit that forms an electrostatic latent image on the electrophotographic photosensitive member.
As the electrophotographic photoreceptor, the electrophotographic photoreceptor of the present invention is used.
The formation of the electrostatic latent image can be performed, for example, by uniformly charging the surface of the electrophotographic photosensitive member and then performing imagewise exposure, and can be performed by the electrostatic latent image forming unit. it can.
The electrostatic latent image forming means includes at least a charger that uniformly charges the surface of the electrophotographic photosensitive member and an exposure device that exposes the surface of the electrophotographic photosensitive member imagewise.
The charging can be performed, for example, by applying a voltage to the surface of the electrophotographic photosensitive member using the charger.

The charger is not particularly limited and may be appropriately selected depending on the purpose. For example, a known contact charging device including a conductive or semiconductive roller, brush, film, rubber blade, etc. And non-contact chargers using corona discharge such as corotrons and corotrons.
The shape of the charging member may take any form such as a magnetic brush or a fur brush in addition to the roller, and can be selected according to the specifications and form of the electrophotographic apparatus. In the case of using a magnetic brush, the magnetic brush is composed of, for example, various ferrite particles such as Zn-Cu ferrite as a charging member, and a non-magnetic conductive sleeve for supporting the same, and a magnet roll included therein. . Or, when using a brush, for example, as a material of the fur brush, a fur treated with carbon, copper sulfide, metal or metal oxide is used, and this is wound or attached to a metal or other conductive core. To make a charger.

The charger is not limited to the contact charger as described above, but has an advantage that an image forming apparatus in which ozone generated from the charger is reduced can be obtained.
It is preferable that the charger is disposed in contact or non-contact with the electrophotographic photosensitive member and charges the surface of the electrophotographic photosensitive member by applying a direct current and an alternating voltage.
Further, the charger is a charging roller having a gap tape on the electrophotographic photosensitive member and arranged in a non-contact manner, and the surface of the electrophotographic photosensitive member is charged by applying a direct current and an alternating voltage to the charging roller. Those are also preferred.

The exposure can be performed, for example, by exposing the surface of the electrophotographic photosensitive member imagewise using the exposure device.
The exposure device is not particularly limited as long as the surface of the electrophotographic photosensitive member charged by the charger can be exposed like an image to be formed, and can be appropriately selected according to the purpose. However, various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system can be used.
In the present invention, an optical backside system that performs imagewise exposure from the backside of the electrophotographic photosensitive member may be employed.

(Development means)
The developing means is means for developing the electrostatic latent image with the toner or developer to form a visible image.
The visible image can be formed, for example, by developing the electrostatic latent image using the toner or developer, and can be performed by the developing unit.
The developing unit is not particularly limited as long as it can be developed using, for example, the toner or the developer, and can be appropriately selected from known ones. For example, the toner or developer is accommodated. Preferred examples include those having at least a developing unit capable of bringing the toner or developer into contact or non-contact with the electrostatic latent image.

The developing device may be a single color developing device or a multi-color developing device. For example, a stirrer for charging the toner or the developer by frictional stirring, and a rotatable magnet. The thing which has a roller etc. are mentioned suitably.
In the developing unit, for example, the toner and the carrier are mixed and stirred, and the toner is charged by friction at that time, and held on the surface of the rotating magnet roller in a raised state to form a magnetic brush. Since the magnet roller is disposed in the vicinity of the electrophotographic photosensitive member, a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is electrically attracted to the electrophotographic photosensitive member. Move to the surface of the body. As a result, the electrostatic latent image is developed with the toner, and a visible image is formed with the toner on the surface of the electrophotographic photosensitive member.
As the developer to be accommodated in the developing device, the toner produced by the method described above is used.

In recent years, in order to achieve high image quality, a toner having a small particle diameter and a nearly spherical shape has been used. However, in the present invention, since toner cleaning becomes difficult, hydrophobic silica is used as an external additive. By using it on the surface, it is possible to improve the cleaning property and to reduce the adhesion between the photoconductor and the toner or between the intermediate transfer belt and the toner. Further, the adhesion force between the toners can be reduced, and the fluidity and charging characteristics can be improved.
However, the silica easily adheres to the surface of the electrophotographic photosensitive member, particularly the adsorbed water on the surface of the photosensitive member. Further, the adhering silica gradually accumulates, or the toner resin adheres, so that the adhering matter appears as an image. Easy to generate images. Therefore, in the present invention, the cleaning means includes a cleaning brush impregnated with a composition containing at least an adsorbent and a binder resin, and can remove adsorbed moisture from the surface layer of the photoreceptor, thereby suppressing silica adhesion. Thus, it is possible to obtain a good image without an abnormal image.

(Transfer means)
The transfer can be performed, for example, by charging the electrophotographic photosensitive member with the transfer charger using the visible image, and can be performed by the transfer unit. The transfer unit includes a primary transfer unit that transfers a visible image onto an intermediate recording medium to form a composite transfer image, and a secondary transfer unit that transfers the composite transfer image onto a recording medium. Embodiments are preferred.
Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.
The recording medium is typically plain paper, but is not particularly limited as long as it can transfer an unfixed image after development, and can be appropriately selected according to the purpose. PET for OHP A base or the like can also be used.

(Cleaning means)
The cleaning step is a step of removing the electrophotographic toner remaining on the electrophotographic photosensitive member, and can be suitably performed by a cleaning unit.
The cleaning means includes a cleaning brush impregnated with a composition containing at least the aforementioned adsorbent and binder resin. Other cleaning means can be used in combination, and a magnetic brush cleaner, an electrostatic brush cleaner, a magnetic roller cleaner, a blade cleaner, a web cleaner and the like are preferable.
In the present invention, when the cleaning brush impregnated with the composition containing at least the aforementioned adsorbent and binder resin and other cleaning means are used in combination, the cleaning brush is disposed upstream, so that the other cleaning used in combination is performed. This is useful because the cleaning function of the means can be utilized more effectively.

(Fixing means)
The fixing step is a step of fixing the visible image transferred to the recording medium using a fixing device, and may be performed each time the toner of each color is transferred to the recording medium, or for the toner of each color. You may perform this simultaneously in the state which laminated | stacked this.
There is no restriction | limiting in particular as said fixing device, Although it can select suitably according to the objective, A well-known heating-pressing means is suitable. Examples of the heating and pressing means include a combination of a heating roller and a pressure roller, a combination of a heating roller, a pressure roller, and an endless belt. The heating in the heating and pressing means is usually preferably 80 ° C to 200 ° C.
In the present invention, for example, a known optical fixing device may be used together with or in place of the fixing step and the fixing unit depending on the purpose.

(Static removal means)
The neutralization step is a step of performing neutralization by applying a neutralization bias to the electrophotographic photosensitive member, and can be suitably performed by a neutralization unit.
The neutralizing means is not particularly limited and may be appropriately selected from known neutralizers as long as it can apply a neutralizing bias to the electrophotographic photosensitive member. For example, a neutralizing lamp is preferably used. Can be mentioned.

(Recycling means)
The recycling step is a step of recycling the electrophotographic color toner removed in the cleaning step to the developing unit, and can be suitably performed by the recycling unit.
There is no restriction | limiting in particular as said recycling means, A well-known conveyance means etc. are mentioned.

(Control means)
The control step is a step of controlling each of the steps, and can be suitably performed by a control unit.
The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as sequencers and computers.

  The image forming apparatus of the present invention uses the electrophotographic photosensitive member having the surface protective layer according to the present invention. For example, the toner image on the recording medium (transfer paper) is obtained after at least charging, image exposure, and development of the photosensitive member. The image forming apparatus includes processes of transferring, fixing, and cleaning the surface of the photoreceptor. In some cases, an image forming method or the like in which an electrostatic latent image is directly transferred to a transfer member and developed does not necessarily have the above-described process arranged on a photosensitive member.

Here, FIG. 4 is a schematic view showing an example of the image forming apparatus of the present invention.
A charging roller 3 is used as a means for charging the photoconductor on average. As other charging means, a corotron device, a scorotron device, a solid discharge element, a needle electrode device, a roller charging device, a conductive brush device, or the like is used, and a known method can be used.
Next, the image exposure unit 5 is used to form an electrostatic latent image on the uniformly charged photoreceptor 1. As the light source, all luminescent materials such as a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), and an electroluminescence (EL) can be used. Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.

Next, the developing unit 6 is used to visualize the electrostatic latent image formed on the photoreceptor 1. Development methods include a one-component development method using a dry toner and a two-component development method. When the photosensitive member is positively (negatively) charged and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. A positive image can be obtained by developing this with negative (positive) toner (electrodetection fine particles), and a negative image can be obtained by developing with positive (negative) toner.
Next, a transfer charger 10 is used to transfer the toner image visualized on the photoreceptor onto the recording medium 9. In addition, a pre-transfer charger may be used for better transfer. As these transfer means, a transfer charger, an electrostatic transfer method using a bias roller, a mechanical transfer method such as an adhesive transfer method and a pressure transfer method, and a magnetic transfer method can be used. As the electrostatic transfer method, the charging means can be used.

Next, a separation charger or a separation claw is used as means for separating the recording medium 9 from the photoreceptor 1. As other separation means, electrostatic adsorption induction separation, side end belt separation, tip grip conveyance, curvature separation, and the like are used. As the separation charger, the charging means can be used.
Next, a cleaning brush 14 impregnated with a composition containing at least an adsorbent and a binder resin of the present invention is used to clean the toner remaining on the photoreceptor after transfer. A cleaning blade 15 may be used in combination. In addition, a pre-cleaning charger may be used for more efficient cleaning. Other cleaning means include a web method, a magnet brush method, and the like, but each may be used alone or in combination.

Next, a neutralizing unit is used for the purpose of removing the latent image on the photoreceptor as required. As the charge removal means, the charge removal lamp 2 and the charge removal charger are used, and the exposure light source and the charging means can be used respectively. In the figure, reference numeral 8 denotes a registration roller.
In addition, known processes can be used for reading, feeding, fixing, paper discharge and the like that are not close to the photoconductor.
The present invention is an image forming apparatus using such an image forming unit.
The image forming means may be fixedly incorporated in a copying apparatus, a facsimile machine, or a printer, but may be incorporated in these apparatuses in the form of a process cartridge and detachable.

(Process cartridge)
The process cartridge of the present invention comprises at least an electrophotographic photosensitive member having a surface protective layer, developing means for developing with toner according to the present invention, and cleaning means according to the present invention, and is a cartridge that can be attached to and detached from the image forming apparatus main body. It is.
FIG. 5 is a schematic view showing an example of the process cartridge of the present invention.
5 includes an electrophotographic photosensitive member (photosensitive drum) 101, a charging unit (charging device) 102, a developing unit (developing device) 104, a transfer unit (transfer device) 106, and a cleaning unit (cleaning brush). 107), and other means as necessary.

Next, the image forming process by the process cartridge 105 shown in FIG. 5 will be described. The electrophotographic photosensitive member 101 is exposed to the surface by charging by the charging means 102 and exposure means (not shown) while rotating in the direction of the arrow. An electrostatic latent image corresponding to the image is formed.
The electrostatic latent image is developed by the developing unit 104, and the obtained visible image is transferred to a recording medium (not shown) by the transfer unit 106 and printed out. Next, the surface of the electrophotographic photosensitive member after the image transfer is cleaned by the cleaning unit 107 and further neutralized by a neutralizing unit (not shown), and the above operation is repeated again.
An image forming apparatus and a process cartridge according to the present invention include a cleaning means provided with a cleaning brush provided with a surface protection layer and an electrophotographic photosensitive member having high wear resistance, and a composition containing at least an adsorbent and a binder resin. Since it is possible to remove adsorbed water on the photoconductor and prevent silica adhesion, it is possible to form high-definition and high-quality images over a long period of time.

The present invention will be specifically described below based on examples. Hereinafter, “part” means “part by mass”.
(Toner Production Example 1)
(Preparation of base particles)
229 parts of bisphenol A ethylene oxide 2-mole adduct, 529 parts of bisphenol A propion oxide 3-mole adduct, 208 parts of terephthalic acid, 46 parts of adipic acid and dibutyltin oxide 2 parts were added and reacted at 230 ° C. under normal pressure for 8 hours. Next, after reacting under reduced pressure of 10 to 15 mmHg for 5 hours, 44 parts of trimellitic anhydride was added to the reaction vessel and reacted at 180 ° C. for 2 hours under normal pressure to synthesize an unmodified polyester resin. .
The obtained unmodified polyester resin had a number average molecular weight of 2500, a weight average molecular weight of 26000, a glass transition temperature of 43 ° C., and an acid value of 25 mgKOH / g.

  1200 parts of water, 540 parts of carbon black Printex 35 (manufactured by Dexa; DBP oil absorption = 42 ml / 100 mg, pH = 9.5) and 1200 parts of unmodified polyester resin were mixed using a Henschel mixer (manufactured by Mitsui Mining). . The resulting mixture was kneaded at 150 ° C. for 30 minutes using two rolls, then rolled and cooled, and pulverized with a pulverizer (manufactured by Hosokawa Micron Corporation) to prepare a master batch.

  In a reaction vessel equipped with a stirrer and a thermometer, 378 parts of unmodified polyester resin, 110 parts of carnauba wax, 22 parts of salicylic acid metal complex E-84 (manufactured by Orient Chemical Co., Ltd.) and 947 parts of ethyl acetate were charged and stirred. The temperature was raised to 80 ° C., held at 80 ° C. for 5 hours, and then cooled to 30 ° C. over 1 hour. Next, 500 parts of a master batch and 500 parts of ethyl acetate were charged into the reaction vessel and mixed for 1 hour to obtain a raw material solution.

  1324 parts of the obtained raw material solution was transferred to a reaction vessel, and filled with 80% by volume of 0.5 mm zirconia beads using a bead mill Ultra Visco Mill (manufactured by Imex Co., Ltd.). Carnauba wax was dispersed by three passes under the condition of a speed of 6 m / sec to obtain a wax dispersion.

  Next, 1324 parts of a 65 mass% ethyl acetate solution of an unmodified polyester resin was added to the wax dispersion. A layered inorganic mineral montmorillonite modified with a quaternary ammonium salt having at least a part of benzyl group (Clayton APA Southern Clay) was added to 200 parts of a dispersion obtained by one pass using Ultraviscomyl under the same conditions as above. 3 parts) (manufactured by Products) are added. K. The mixture was stirred for 30 minutes using a homodisper (manufactured by Tokushu Kika Kogyo Co., Ltd.) to obtain a toner material dispersion.

In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 682 parts of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, 22 parts of trimellitic anhydride And 2 parts of dibutyltin oxide were added and reacted at 230 ° C. for 8 hours under normal pressure. Next, it was made to react under reduced pressure of 10-15mHg for 5 hours, and the intermediate polyester resin was synthesize | combined.
The obtained intermediate polyester resin had a number average molecular weight of 2,100, a weight average molecular weight of 9,500, a glass transition temperature of 55 ° C., an acid value of 0.5 mgKOH / g, and a hydroxyl value of 51 mgKOH / g.

  Next, 410 parts of the intermediate polyester resin, 89 parts of isophorone diisocyanate, and 500 parts of ethyl acetate are charged into a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe, and reacted at 100 ° C. for 5 hours. Was synthesized. The free isocyanate content of the obtained prepolymer was 1.53% by mass.

  In a reaction vessel equipped with a stir bar and a thermometer, 170 parts of isophoronediamine and 75 parts of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to synthesize a ketimine compound. The amine value of the obtained ketimine compound was 418 mgKOH / g.

  In a reaction vessel, 749 parts of a dispersion of toner material, 115 parts of a prepolymer and 2.9 parts of a ketimine compound are charged and mixed at 5,000 rpm for 1 minute using a TK homomixer (manufactured by Tokushu Kika). A mixture was obtained.

  In a reaction vessel equipped with a stirring bar and a thermometer, 683 parts of water, 11 parts of reactive emulsifier (sodium salt of sulfuric acid ester of methacrylic acid ethylene oxide adduct), Eleminol RS-30 (manufactured by Sanyo Chemical Industries), styrene 83 Parts, 83 parts of methacrylic acid, 110 parts of butyl acrylate and 1 part of ammonium persulfate were stirred at 400 rpm for 15 minutes to obtain an emulsion. The emulsion was heated, heated to 75 ° C. and reacted for 5 hours. Next, 30 parts of a 1% by mass ammonium persulfate aqueous solution was added and aged at 75 ° C. for 5 hours to prepare a resin particle dispersion.

  Next, 990 parts of water, 83 parts of a resin particle dispersion, 37 parts of a 48.5% by weight aqueous solution of sodium dodecyl diphenyl ether disulfonate, Eleminol MON-7 (manufactured by Sanyo Chemical Industries), 1 part of sodium carboxymethyl cellulose polymer dispersant % Aqueous solution serogen BS-H-3 (Daiichi Kogyo Seiyaku Co., Ltd.) 135 parts and ethyl acetate 90 parts were mixed and stirred to obtain an aqueous medium.

To 1200 parts of the obtained aqueous medium, 867 parts of an oil phase mixed liquid was added and mixed at 13000 rpm for 20 minutes using a TK homomixer to prepare a dispersion (emulsified slurry).
Furthermore, the emulsified slurry was charged into a reaction vessel equipped with a stirrer and a thermometer, and after removing the solvent at 30 ° C. for 8 hours, aging was performed at 45 ° C. for 4 hours to obtain a dispersed slurry.
Subsequently, 100 parts by mass of the dispersion slurry was filtered under reduced pressure, 100 parts of ion-exchanged water was added to the filter cake, mixed at 12000 rpm for 10 minutes using a TK homomixer, and then filtered.
To the obtained filter cake, 10% by mass hydrochloric acid was added to adjust the pH to 2.8, and the mixture was mixed for 10 minutes at 12,000 rpm using a TK homomixer, followed by filtration.
Furthermore, 300 parts of ion-exchanged water was added to the obtained filter cake, mixed for 10 minutes at 12000 rpm using a TK homomixer, and then filtered twice to obtain a final filter cake.
The obtained final filter cake was dried at 45 ° C. for 48 hours using a circulating drier and sieved with a mesh having a mesh size of 75 μm to obtain toner base particles.

(Attaching external additives)
To 100 parts of the obtained toner base particles, 1.5 parts of hydrophobic silica surface-treated with hexamethyldisilazane and having a hydrophobicity of 65% and an average primary particle diameter of 140 nm are added. For 3 minutes under the condition of a peripheral speed of 33 m / s. The mixed powder was passed through a mesh having a mesh size of 38 μm, and coarse powder was removed to prepare an electrostatic charge image developing toner 1 to which a hydrophobic fine powder was externally added.

(Toner Production Example 2)
An electrostatic charge image developing toner 2 was produced in the same manner as in Toner Production Example 1 except that the following external additives were added.
(Attaching external additives)
To 100 parts of the obtained toner base particles, 1.5 parts of hydrophobic silica surface-treated with hexamethyldisilazane having a hydrophobicity of 65% and an average primary particle diameter of 200 nm are added, and a Henschel mixer (Mitsui Mining Co., Ltd.) is added. For 3 minutes under the condition of a peripheral speed of 33 m / s. The mixed powder was passed through a mesh having a mesh size of 38 μm to remove coarse powder, and an electrostatic charge image developing toner 2 externally added with hydrophobic fine powder was produced.

(Toner Production Example 3)
An electrostatic charge image developing toner 3 was produced in the same manner as in Toner Production Example 1 except that the following external additives were added.
(Attaching external additives)
To 100 parts of the obtained toner base particles, 1.5 parts of hydrophobic silica having a surface treatment with hexamethyldisilazane of 65% and an average primary particle diameter of 70 nm are added, and a Henschel mixer (Mitsui Mining Co., Ltd.) is added. For 3 minutes under the condition of a peripheral speed of 33 m / s. The mixed powder was passed through a mesh having a mesh size of 38 μm to remove a coarse powder, and an electrostatic charge image developing toner 3 was prepared by externally adding a hydrophobic fine powder.

(Toner Production Example 4)
An electrostatic charge image developing toner 4 was produced in the same manner as in Toner Production Example 1 except that the following external additives were added.
(Attaching external additives)
To 100 parts of the obtained toner base particles, 1.5 parts of hydrophobic silica surface-treated with hexamethyldisilazane having a hydrophobicity of 65% and an average primary particle diameter of 250 nm are added, and a Henschel mixer (Mitsui Mining Co., Ltd.) is added. For 3 minutes under the condition of a peripheral speed of 33 m / s. The mixed powder was passed through a mesh having a mesh size of 38 μm to remove coarse powder, and an electrostatic charge image developing toner 4 to which hydrophobic fine powder was externally added was prepared.

(Toner Production Example 5)
An electrostatic charge image developing toner 5 was produced in the same manner as in Toner Production Example 1 except that the following external additives were added.
(Attaching external additives)
To 100 parts of the obtained toner base particles, 1.5 parts of silica having an average primary particle diameter of 140 nm without surface treatment is added, and a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.) is used at a peripheral speed of 33 m / s. Mixed for 3 minutes. The mixed powder was passed through a mesh having a mesh size of 38 μm to remove coarse powder, and an electrostatic charge image developing toner 5 to which fine powder was externally added was produced.

(Photoreceptor Preparation Example 1)
<Production of electrophotographic photoreceptor>
An undercoating layer coating solution, a charge generation layer coating solution, and a charge transport layer coating solution having the following composition are sequentially applied onto an aluminum cylinder by dip coating, dried, and coated with a thickness of 3.5 μm. A charge generation layer having a thickness of 0.2 μm, and a charge transport layer having a thickness of 23 μm were formed.
-Undercoat layer coating solution-
・ Alkyd resin (Beckosol 1307-60-EL, manufactured by Dainippon Ink & Chemicals, Inc.)
... 6 parts by mass Melamine resin (Super Becamine G-821-60, manufactured by Dainippon Ink & Chemicals, Inc.)
... 4 parts by mass-Titanium oxide ... 40 parts by mass-Methyl ethyl ketone ... 50 parts by mass

・ポリビニルブチラール（ＸＹＨＬ、ＵＣＣ社製） ・・・０．５質量部
・シクロヘキサノン ・・・２００質量部
・メチルエチルケトン ・・・８０質量部 -Charge generation layer coating solution-
-Bisazo pigment represented by the following structural formula: 2.5 parts by mass

・ Polyvinyl butyral (XYHL, manufactured by UCC Co., Ltd.) 0.5 mass part Cyclohexanone 200 mass parts Methyl ethyl ketone 80 mass parts

・テトラヒドロフラン ・・・１００質量部
・１質量部のシリコーンオイルのテトラヒドロフラン溶液
（ＫＦ５０−１００ＣＳ、信越化学工業株式会社製） ・・・１質量部 -Charge transport layer coating solution-
-Bisphenol Z-type polycarbonate (Panlite TS-2050, manufactured by Teijin Chemicals Ltd.) ... 10 parts by mass-Charge transport material represented by the following structural formula ... 7 parts by mass

Tetrahydrofuran: 100 parts by mass Tetrahydrofuran solution of 1 part by mass of silicone oil (KF50-100CS, manufactured by Shin-Etsu Chemical Co., Ltd.): 1 part by mass

・光重合開始剤
（１−ヒドロキシ−シクロヘキシル−フェニル−ケトン、イルガキュア１８４、
チバ・スペシャルティ・ケミカルズ社製） ・・・１０質量部
・テトラヒドロフラン ・・・１，２００質量部 Next, spray coating is performed on the charge transport layer using a surface protective layer coating solution having the following composition, and light irradiation is performed under the conditions of a metal halide lamp, irradiation intensity: 500 mW / cm ² , and irradiation time: 20 seconds. And dried at 130 ° C. for 30 minutes to form a surface protective layer having a thickness of 4.0 μm. Thus, the electrophotographic photoreceptor 1 was produced.
-Surface protective layer coating solution-
・ Trifunctional radical polymerizable compound (trimethylolpropane triacrylate, TMPTA, manufactured by Tokyo Chemical Industry Co., Ltd.)
... 75 parts by mass-Radical polymerizable compound having a charge transporting structure represented by the following structural formula
... 95 parts by mass

Photopolymerization initiator (1-hydroxy-cyclohexyl-phenyl-ketone, Irgacure 184,
Ciba Specialty Chemicals) ··· 10 parts by mass · Tetrahydrofuran ··· 1,200 parts by mass

(Photoreceptor preparation example 2)
<Production of electrophotographic photoreceptor>
An electrophotographic photoreceptor 2 was produced in the same manner as in the photoreceptor preparation example 1 except that the trifunctional radical polymerizable compound in the surface protective layer coating solution of the photoreceptor preparation example 1 was changed to the following. .
・ Tetrafunctional radical polymerizable compound (Pentaerythritol tetraacrylate, A-TMMT, Shin-Nakamura Chemical Co., Ltd.)
... 75 parts by mass

(Photoreceptor Preparation Example 3)
<Production of electrophotographic photoreceptor>
An electrophotographic photoreceptor 3 was produced in the same manner as in the photoreceptor preparation example 1 except that the trifunctional radical polymerizable compound in the surface protective layer coating solution of the photoreceptor preparation example 1 was changed to the following. .
-Bifunctional radically polymerizable compound (Bifunctional acrylate: KAYARAD NPGDA, manufactured by Nippon Kayaku)
... 75 parts by mass

・フッ素樹脂粒子（ＭＰＥ‐０５６、三井デュポンフロロケミカル社製）１０質量部
・フッ素系界面活性剤（モディパーＦ２００、日本油脂社製）
１０質量部（固形分：３質量部）
・メラミン樹脂（スーパーベッカミン Ｇ−８２１−６０，大日本インキ化学工業製）
５質量部
・テトラヒドロフラン １８０質量部
・シクロヘキサノン ５０質量部 (Photosensitive member production example 4)
<Production of electrophotographic photoreceptor>
The surface protective layer coating solution of Photosensitive Member Preparation Example 1 was changed to the following, and after coating the surface protective layer coating solution, the coating was dried by heating at a heating temperature of 150 ° C. for 30 minutes to a thickness of 4.0 μm. A surface protective layer was formed.
-Surface protective layer coating solution-
・ 2 parts by mass of low molecular charge transport material

・ Fluoropolymer particles (MPE-056, manufactured by Mitsui DuPont Fluorochemical Co., Ltd.) 10 parts by mass ・ Fluorosurfactant (Modiper F200, manufactured by NOF Corporation)
10 parts by mass (solid content: 3 parts by mass)
・ Melamine resin (Super Becamine G-821-60, manufactured by Dainippon Ink and Chemicals)
5 parts by mass-Tetrahydrofuran 180 parts by mass-Cyclohexanone 50 parts by mass

(Photoreceptor Preparation Example 5)
<Production of electrophotographic photoreceptor>
In Photoconductor Preparation Example 1, a photoconductor without a surface protective layer was prepared without applying the surface protective layer coating solution.

(Cleaning brush production example 1)
<Material for Cleaning Brush Impregnated with Composition Containing Adsorbent and Binder>
SA-7 made of acrylic conductive fiber (Toray Industries, Inc.)
<Composition of an adsorbent used for impregnation and a binder resin and a brush production example>
Adsorbent: B-type silica gel (manufactured by Fuji Gel Sangyo Co., Ltd.) 50 parts by mass Conductive agent: Zinc antimonate (CELNAX CX-Z210IP manufactured by Nissan Chemical Industries) 10 parts by mass Binder resin:
Oil-free alkyd resin (Beckolite 46-118 manufactured by Dainippon Ink and Chemicals)
Melamine resin (Super Becamine G-821-60 manufactured by Dainippon Ink and Chemicals)
(Alkyd resin / melamine resin = 3/2 mass ratio) 40 parts by mass Dispersion medium: 400 parts by mass of 2-butanone

50 parts by mass of an adsorbent, 10 parts by mass of a conductive agent, 40 parts by mass of a binder resin, and 250 parts by mass of a dispersion medium were dispersed for 6 hours using a ball mill disperser using φ5 alumina media. Thereafter, 150 parts by mass of a dispersion medium was added, mixed and stirred, and a brush impregnating solution was prepared.
Next, the fibers are planted on the base fabric so that the tip is looped, and a brush is formed. Then, a brush impregnating solution is applied to the back side of the base fabric, followed by a drying process. A composition containing an adsorbent and a binder resin was impregnated.
Thereafter, the base cloth was cut into a string having a width of 10 mm, and a loop-shaped cleaning brush 1 was prepared by being wound around a brass rod rod having a diameter of 9 mm and fixed by using an adhesive.

(Cleaning brush production example 2)
A cleaning brush 2 was prepared in the same manner except that the adsorbent of Cleaning Brush Preparation Example 1 was changed to A-type zeolite (A-4 manufactured by Tosoh Corporation).
(Cleaning brush preparation example 3)
A cleaning brush 3 was prepared in the same manner except that the adsorbent of the cleaning brush preparation example 1 was changed to acrylic resin beads (Tuftec HU-700E manufactured by Toyobo).

(Cleaning brush preparation example 4)
A cleaning brush 4 was prepared in the same manner except that the adsorbent in Preparation Example 1 for the cleaning brush was changed to A-type silica gel (Fujigel Sangyo Co., Ltd.).
(Cleaning brush preparation example 5)
A cleaning brush 5 was produced in the same manner except that the adsorbent of the cleaning brush production example 1 was changed to activated carbon (Kuraray Coal GW, Kuraray Chemical Co., Ltd.).

(Cleaning brush preparation example 6)
A cleaning brush 6 was prepared in the same manner except that the binder resin of Preparation Example 1 for cleaning brush was changed to copolymerized polyamide (Amilan CM-8000 manufactured by Toray Industries, Inc.) and the dispersion medium was changed to methanol and butanol.
(Methanol / butanol = 7/3 mass ratio)

(Cleaning brush preparation example 7)
A cleaning brush 7 was prepared in the same manner except that the adsorbent of Cleaning Brush Preparation Example 1 was not added.
(Cleaning brush preparation example 8)
In cleaning brush preparation example 1, a cleaning brush 8 was prepared using SA-7 (manufactured by Toray Industries, Inc.) made of acrylic conductive fiber without performing the impregnation treatment.

Replace the toner, photoconductor, and cleaning brush produced as described above with the standard components of the digital copying machine imagio MP9001 (manufactured by Ricoh) in the combinations shown in Table 1. Image evaluation and the photoreceptor film thickness before and after repeated use 100,000 times were measured with an eddy current film thickness meter (Fischerscope MMS: manufactured by Fischer) to determine the amount of wear.
Incidentally, the standard equipment of the cleaning means of the digital copying machine has a cleaning brush and a cleaning blade as shown in FIG. 4, and the cleaning blade is used as it is, and is replaced with a cleaning brush which is produced only by the cleaning brush.

The test results are shown in Table 2.

As shown in Examples 1 to 12, a photosensitive member provided with a surface protective layer, and a toner obtained by adhering at least one or more types of hydrophobic silica particles to the surface of toner base particles are used. In an image forming apparatus provided with a cleaning brush impregnated with a composition containing at least an adsorbent and a binder resin as a cleaning means, a good image can be obtained while maintaining high wear resistance of the photoreceptor. Is clear.
In Comparative Examples 1 and 2, since the cleaning brush does not contain an adsorbent, the hydrophobic silica used for the toner external additive adheres to the photoconductor through adsorbed water, and silica filming is observed on the entire photoconductor. As a result, white spots occurred in the halftone portion. Further, in Comparative Example 3, silica that was not hydrophobized was attached to the toner, and the adhesion between the photoconductor and the toner was strong and streaks were generated in the image. Further, in Comparative Example 4, since the photoconductor without the protective layer was used, the photoconductor had a large amount of wear, and white stripes were observed in the halftone portion.

(Figure 1)
31 Photoconductor 32 Cleaning brush 33 Core 34 Flicker 35 Blade 36 Blade holder 37 Brush nip 38 Toner A Photoconductor rotation direction B Cleaning brush rotation direction

(Figure 2)
21 Base fabric 22 Conductive fiber 23 Adsorbent-containing resin layer

(Figure 3)
DESCRIPTION OF SYMBOLS 11 Photosensitive layer 12 Surface protective layer 13 Conductive base | substrate 111 Undercoat layer 112 Charge generation layer 113 Charge transport layer

(Fig. 4)
DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Static elimination lamp 3 Charging roller 5 Image exposure part 6 Development unit 8 Registration roller 9 Recording medium 10 Transfer charge 14 Cleaning brush 15 Cleaning blade

(Fig. 5)
101 Photosensitive drum 102 Charging device 104 Developing device 105 Process cartridge 106 Transfer device 107 Cleaning brush

JP-A-48-47345 Japanese Patent Application Laid-Open No. 08-248851 JP 2001-242758 A JP 2002-055582 A JP-A-2005-208622 Japanese Patent Laid-Open No. 9-22155 JP-A-11-167224 Japanese Patent No. 2793647 Japanese Patent No. 2619424

Claims (7)

An electrophotographic photoreceptor in which at least a photosensitive layer and a surface protective layer are provided on a conductive substrate; a charging means for charging the surface of the electrophotographic photoreceptor; an image exposing means for forming an electrostatic latent image by exposure; An image forming apparatus comprising at least developing means for developing the electrostatic latent image with toner, transfer means for transferring the developed toner image, and cleaning means for cleaning the surface of the electrophotographic photoreceptor, the toner contains at least a binder resin and a colorant are those silica fine particles formed by the process of at least one or more hydrophobic the surface of the toner base particles formed by impregnation, and the cleaning means, electrically conductive which comprises a rotatable cleaning brush composition is wound on the core metal is impregnated containing the adsorbent and a binder resin to the base fabric was flocked sex fibers An image forming apparatus wherein there. 2. The image forming apparatus according to claim 1, wherein the adsorbent is at least one of zeolite, silica gel, and acrylic particles. An electrophotographic photoreceptor in which at least a photosensitive layer and a surface protective layer are provided on a conductive substrate; a charging means for charging the surface of the electrophotographic photoreceptor; an image exposing means for forming an electrostatic latent image by exposure; An image forming apparatus comprising at least developing means for developing the electrostatic latent image with toner, transfer means for transferring the developed toner image, and cleaning means for cleaning the surface of the electrophotographic photoreceptor, The toner contains at least a binder resin and a colorant, and is formed by adhering at least one or more types of hydrophobized silica fine particles to the surface of the toner base particles, and the cleaning means includes at least It has a cleaning brush impregnated with at least one adsorbent of zeolite, silica gel, and acrylic particles and a binder resin. Image forming apparatus characterized by. The image forming apparatus according to claim 2, wherein the silica gel is B-type silica gel.   The image forming apparatus according to claim 1, wherein a primary average particle diameter of at least one kind of silica fine particles formed by hydrophobic treatment attached to the toner surface is 100 to 200 nm.   6. The image forming apparatus according to claim 1, wherein the surface protective layer of the electrophotographic photoreceptor is formed by polymerizing at least a trifunctional or higher functional radical polymerizable monomer.   A toner comprising at least one electrophotographic photosensitive member having a surface protective layer, at least a binder resin and a colorant, and at least one kind of hydrophobized silica fine particles attached to the surface of the toner base particles. The image forming apparatus according to claim 1, wherein the image forming apparatus according to claim 1, wherein the image forming apparatus includes: a developing unit that develops the toner by means of a cleaning unit; A process cartridge which is detachable from the main body.

Images