JP4974720B2 - Electrostatic latent image carrier, image forming apparatus, process cartridge - Google Patents

Description

  The present invention can maintain high wear resistance over a long period of time, and there is almost no fluctuation in electric characteristics, and the location of the photoconductor characteristics such as wear resistance and electric characteristics can be obtained by uniformly curing the crosslinked surface layer. The present invention relates to an electrostatic latent image carrier that has less dependency and has excellent durability and stable electrical characteristics and high-quality image formation over a long period of time. The present invention also relates to an image forming method, an image forming apparatus, and a process cartridge for the image forming apparatus using the long-life, high-performance photoconductor.

In recent years, organic photoreceptors (OPC) have been widely used in copying machines, facsimile machines, laser printers, and composite machines in place of inorganic photoreceptors because of their good performance and various advantages. This is because, for example, (1) optical characteristics such as the light absorption wavelength range and the amount of absorption, (2) electrical characteristics such as high sensitivity and stable charging characteristics, and (3) material selection range (4) Ease of manufacturing, (5) Low cost, (6) Non-toxicity, and the like.
On the other hand, the diameter of the photoconductor has recently been reduced due to the downsizing of the image forming apparatus, and the high speed of the machine and the maintenance-free movement have been added to increase the durability of the photoconductor. From this point of view, organophotoreceptors are generally soft because the surface layer is mainly composed of low-molecular charge transport materials and inert polymers, and when used repeatedly in electrophotographic processes, they are mechanically driven by development systems and cleaning systems. There is a drawback that wear is likely to occur due to a typical load. In addition, due to the demand for higher image quality, the cleaning blade is required to increase its rubber hardness and contact pressure for the purpose of improving the cleaning property as the particle size of the toner particles is reduced. This also promotes the wear of the photoreceptor. It is a factor. Such abrasion of the photoreceptor deteriorates electrical characteristics such as sensitivity deterioration and chargeability, and causes abnormal images such as image density reduction and background stains. Further, scratches where wear is locally generated cause streak-like stain images due to poor cleaning. Under the present circumstances, the wear and scratches are rate-determined and the life of the photoconductor has been replaced.
Therefore, it is indispensable to reduce the above-mentioned wear amount in order to increase the durability of the organic photoreceptor, and to provide excellent cleaning properties and transfer properties, it has good surface properties, and further has electrophotographic characteristics. There is a need for an organic photoreceptor that does not depend on the location for a long period of time and maintains stable high performance, and these are the most pressing issues in the field.

For example, Patent Document 1 uses a colloidal silica-containing curable silicone resin as a surface protective layer of a photoreceptor, and Patent Documents 2 and 3 describe an organic silicon-modified hole transporting compound as a curable organic silicon. There has been proposed a photoreceptor having a resin layer bonded on the surface of a polymer. However, photoreceptors using these curable silicone resins have insufficient repetitive electrophotographic characteristics and environmental characteristics, are prone to fog and image blurring, and are equipped with mechanisms such as a drum heater for practical use. Therefore, it is necessary to suppress the occurrence of image blur, which leads to an increase in size and cost of the apparatus. Further, it is insufficient for durability as a long-life photosensitive member required in recent years.
Patent Document 4 proposes a method of forming a protective layer with a urethane resin obtained by crosslinking and polymerizing a plurality of polyols and polyisocyanates. However, this proposed method is expected to make it difficult to increase the thickness of the protective layer, particularly in the low-potential development process, because the residual potential of the exposed portion is dependent on the film thickness. Further, even in a structure in which a charge transporting substance is crosslinked and polymerized, the film thickness dependence of the exposed portion potential is not eliminated, and it can be said that the residual potential reducing effect of the exposed portion is insufficient.
Patent Document 5 proposes a method in which specific conductive fine particles are contained in a protective layer obtained by crosslinking a reactive charge transporting substance and polyisocyanate by thermal curing, and the residual potential in the exposed area is considerably improved. Has been. However, the durability of the outermost layer formed of the thermosetting resin is insufficient for the durability as a long-life photoreceptor required in recent years. The electrostatic latent image bearing member on which the curable surface layer is formed by heat crosslinking as described above has a simple manufacturing process and a great cost advantage. However, it still has a durability as a long-life photosensitive member. I have to say that it is insufficient.

On the other hand, Patent Document 6 proposes an electrostatic latent image carrier having a surface layer composed of a crosslinked layer obtained by curing a radical polymerizable monomer and a radical polymerizable compound having a charge transport structure. And achieve electrical durability.
However, there is no sufficient description of the photoreceptor temperature at the time of forming this crosslinked surface layer, and it is only described that the photoreceptor temperature during light irradiation is controlled so as not to exceed 50 ° C. However, as a result of investigations by the inventors, the photoreceptor temperature is also an important factor for forming a crosslinked surface layer, and the crosslinking reaction may not proceed sufficiently under light irradiation conditions that do not exceed 50 ° C. by continuous irradiation. all right. Therefore, in order to proceed with the crosslinking reaction while maintaining the photoreceptor temperature at 50 ° C. or lower, the irradiation time is irradiated for an extremely short time, or divided into a plurality of times in short intervals, the irradiation energy is suppressed, and the irradiation time is reduced. It was necessary to take measures such as lengthening. However, under such irradiation conditions, the uniformity of the cross-linking reaction is not maintained, and variations in characteristics within one photoconductor, particularly variations in the potential of the exposed area, occur.
Patent Documents 7 and 8 also disclose an invention in which a photopolymerizable monomer is cured to form a cross-linked surface protective layer and the temperature of the photoconductor during light irradiation is regulated. However, there is little detailed explanation of the temperature control method in these, and in the examples there is only a description that the temperature is controlled by air cooling, but when air is used as the cooling medium, the cooling efficiency is low due to poor thermal conductivity. Is very bad, the amount of heat generated when curing with strong irradiation light cannot be reduced, photocuring for a long time is impossible, and the cooling efficiency in one photoconductor with flow rate and method As a result, the uniformity of the cross-linking reaction was not maintained, which appeared as variations in wear resistance and electrostatic characteristics within one photoconductor.
For the above reasons, it cannot be said that a photoreceptor having a cross-linked photosensitive layer obtained by chemically bonding the charge transporting structure in these prior arts has sufficient comprehensive characteristics at present.

Japanese Patent Laid-Open No. 6-118681 Japanese Patent Laid-Open No. 9-124943 JP-A-9-190004 JP 2004-117766 A JP 2006-330086 A JP 2004-302450 A JP 2001-125297 A JP 2004-240305 A

  An object of the present invention is to solve various problems in the prior art and achieve the following objects. In other words, the present invention has high wear resistance, and furthermore, there is little variation in the characteristics of the photoconductor within one photoconductor, so that excellent durability and high-quality image formation can be stably performed over a long period of time. It is an object of the present invention to provide a highly durable electrostatic latent image carrier capable of producing an image, an image forming apparatus using the electrostatic latent image carrier, an image forming method, and a process cartridge.

The features of the present invention, which is a means for solving the above problems, are listed below.
In the electrostatic latent image bearing member having at least a photosensitive layer on a conductive support, the inventors of the present invention provide radical polymerization in which the surface layer of the photosensitive layer has at least a charge transporting structure and the radical polymerizable group is trifunctional or higher. And a cross-linked layer obtained by curing a radical polymerizable compound having a charge transporting structure and the cross-linked surface layer, M _x Sb _y O _z (where M represents a metal element, x, y). And z represents the molar ratio of each element.) It was found that the above-mentioned problems can be achieved by using an electrostatic latent image carrier containing at least one conductive fine particle represented by It came.

Sunawa Chi, latent electrostatic image bearing member of the present invention, the electrostatic latent image bearing member having at least a photosensitive layer on a conductive support, a radical having no surface layer is at least a charge transport structure of the photosensitive layer It consists of a crosslinked layer obtained by curing a radically polymerizable monomer having a trifunctional or higher functional group and a radically polymerizable compound having a charge transporting structure, and the crosslinked surface layer has the following formula: M _x Sb _y O _z (where M Represents a metal element, x, y, and z represent the molar ratio of each element ), and contains at least one conductive fine particle containing zinc antimonate (ZnSb ₂ O ₆ ). It becomes.
An electrostatic latent image carrier comprising a radically polymerizable monomer having a radically polymerizable group having at least a trifunctional or higher functional group having no charge transporting structure and a crosslinked layer obtained by curing a radically polymerizable compound having a charge transporting structure, As described above, the characteristics of the photoconductor in one photoconductor vary, and there is a problem that the residual potential of the exposed portion varies depending on the location, resulting in a potential difference depending on the location of the exposed portion. As a result, if an image such as a halftone image in which the exposed portion potential difference appears more conspicuously appears as a difference in image density. However, the electrostatic latent image carrier of the present invention has the following formula on the surface layer: M _x Sb _y O _z (where M represents a metal element. _X , y, and z represent the molar ratio of each element. The residual potential can be suppressed by containing at least one kind of conductive fine particles represented by the formula (1)), and as a result, the variation in the potential of the exposed portion in one carrier is reduced, resulting in a high-quality image. A highly durable electrostatic latent image carrier capable of outputting the above is provided.

The image forming apparatus of the present invention uses an electrostatic latent image carrier, an electrostatic latent image forming unit for forming an electrostatic latent image on the electrostatic latent image carrier, and the electrostatic latent image using toner. A developing unit that develops a visible image by development; a transfer unit that transfers the visible image to a recording medium; and a fixing unit that fixes the transferred image transferred to the recording medium. The electrostatic latent image carrier is the electrostatic latent image carrier of the present invention. As a result, a good image can be stably formed over a long period of time.
The image forming method of the present invention includes an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier, and developing the electrostatic latent image with toner to form a visible image. The electrostatic latent image carrier comprises at least a development step, a transfer step for transferring the visible image to a recording medium, and a fixing step for fixing the transferred image transferred to the recording medium. The electrostatic latent image carrier. As a result, a good image can be stably formed over a long period of time.
The process cartridge of the present invention comprises at least one of an electrostatic latent image forming unit, an exposure unit, a developing unit, a transfer unit, and a cleaning unit, and the electrostatic latent image carrier of the present invention. As a result, it is excellent in convenience and a good image can be stably formed over a long period of time.

  According to the present invention, an electrostatic latent image that can solve conventional problems, has excellent wear resistance, and can stably output a good image by suppressing potential variation in an exposed portion. There can be provided a carrier, an image forming method using the electrostatic latent image carrier, an image forming apparatus equipped with the photoreceptor, and a process cartridge.

The best mode for carrying out the present invention will be described below with reference to the drawings.
(Electrostatic latent image carrier)
The electrostatic latent image carrier of the present invention comprises a support and at least a photosensitive layer on the support, and further comprises a protective layer, an intermediate layer, and other layers as required.
The electrostatic latent image carrier of the present invention is an electrostatic latent image carrier having at least a photosensitive layer on a conductive support, and the surface layer of the photosensitive layer has at least a radical polymerizable group having no charge transporting structure. It consists of a cross-linked layer obtained by curing a tri- or higher functional radical polymerizable monomer and a radical polymerizable compound having a charge transporting structure, and the cross-linked surface layer has the following formula: M _x Sb _y O _z (where M is a metal element X, y, and z represent the molar ratio of each element.) And contains at least one kind of conductive fine particles.
In the first embodiment, the electrostatic latent image carrier is provided with a single-layer type photosensitive layer on a support, and further includes a protective layer, an intermediate layer, and other layers as necessary.
Further, in the second embodiment, the electrostatic latent image carrier is further provided with a support, and a laminated photosensitive layer having a charge generation layer and a charge transport layer at least in this order on the support. Depending on the case, it has a protective layer, an intermediate layer, and other layers. In the second embodiment, the charge generation layer and the charge transport layer may be laminated in reverse.
In the single-layer type photosensitive layer, the outermost surface layer corresponds to a photosensitive layer or a protective layer formed on the photosensitive layer. In the laminated photosensitive layer, the outermost surface layer corresponds to a charge transport layer or a protective layer formed on the charge transport layer.

  Here, FIG. 1 is a schematic cross-sectional view of the electrostatic latent image carrier of the present invention, in which a photosensitive layer 202 is provided on a support 201. 2, FIG. 3, FIG. 4, and FIG. 5 show examples of the layer structure of another electrostatic latent image carrier of the present invention. FIG. 2 shows that the photosensitive layer is a charge generation layer (CGL). ) 203 and a charge transport layer (CTL) 204. In FIG. 3, an undercoat layer 205 is inserted between a support 201, a charge generation layer (CGL) 203 of a function separation type photosensitive layer, and a charge transport layer (CTL) 204. FIG. 4 shows a type in which a protective layer 206 is laminated on the charge transport layer 204. FIG. 5 shows a type in which an intermediate layer 207 is provided between the undercoat layer 205 and the charge generation layer 203. The electrostatic latent image carrier of the present invention may have any combination of the above other layers and photosensitive layer types as long as it has at least the photosensitive layer 202 on the support 201. .

<Outermost surface layer>
The outermost surface layer is composed of a crosslinked layer obtained by curing a radically polymerizable monomer having a radically polymerizable group having at least a trifunctional or higher radical polymerizable group having no charge transporting structure and a charge transporting structure, and the crosslinked surface layer And at least one type of conductive fine particles represented by the following formula, M _x Sb _y O _z (where M represents a metal element, and x, y, and z represent a molar ratio of each element). And an electrostatic latent image carrier having high durability and capable of outputting a high-quality image over a long period of time is achieved by containing zinc antimonate (ZnSb ₂ O ₆ ). .

The reasons for this are as follows.
The photoconductor of the present invention uses a radically polymerizable monomer having a radically polymerizable group having three or more functional groups in the surface layer, thereby developing a three-dimensional network structure and a highly hard crosslinked surface having a very high degree of crosslinking. A layer is obtained and high wear resistance is achieved. On the other hand, when only monofunctional and bifunctional radically polymerizable monomers are used, the cross-linking bond in the cross-linked surface layer becomes dilute, and a dramatic improvement in wear resistance cannot be achieved. When a polymer material is contained in the cross-linked surface layer, the development of the three-dimensional network structure is inhibited and the degree of cross-linking is lowered, so that sufficient wear resistance cannot be obtained as compared with the present invention. Furthermore, the compatibility between the polymer material and the cured product resulting from the reaction of the radical polymerizable composition (radical polymerizable monomer or radical polymerizable compound having a charge transporting structure) is poor, resulting in localized from phase separation. Wears and appears as a scratch on the surface.
In addition, in the formation of the crosslinked surface layer of the present invention, in addition to the trifunctional radical polymerizable monomer, a radical polymerizable compound having a charge transporting structure is contained, and the radical polymerizable group is trifunctional or higher. These radically polymerizable monomers are incorporated into the cross-linking during curing. On the other hand, when a low molecular charge transport material having no functional group is contained in the cross-linked surface layer, precipitation of the low molecular charge transport material and white turbidity occur due to its low compatibility, and the cross-linked surface layer The mechanical strength also decreases.

In addition, the conductive fine particles have an effect of suppressing variations in exposed portion potential due to non-uniformity of the crosslinking reaction.
The reason for this behavior is not clearly understood, but the following can be considered. Since the charge transfer of the conductive fine particles is performed not by ionic conduction but by electronic conduction, if the conductive fine particles are contained in the outermost layer, the charge transfer due to electron conduction acts on radical polymerization, resulting in potential variation in the exposed area. There is a possibility that the effect of reducing the heterogeneity of the reaction of the radically polymerizable compound which is a cause of the above is exhibited.
Examples of the conductive particles include metals, metal oxides, and carbon black. In particular, M _x Sb _y O _z (where M represents a metal element. _X , y, and z are each The metal element M includes Zn, In, Sn, Ti, Zr, and the like, and Zn and In are particularly preferable.
Said x, y, and z represent the molar ratio of each element. When the conductive fine particles are Zn _x Sb _y O _z , the ratio is 1: 1.6 to 2.4: 5 to 7. When the conductive fine particles are In _x Sb _y O _z , the ratio is 1: 0.02 to 1.25: 1.55 to 4.63.
Examples of the metal include aluminum, zinc, copper, chromium, nickel, silver, and stainless steel, or those obtained by depositing these metals on the surface of the resin particles. As the metal oxide, ultrafine particles such as zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, tin-doped indium oxide, antimony-doped tin oxide, and zirconium oxide can be used.

Examples of conductive fine particles represented by M _x Sb _y O _z (wherein M represents a metal element, and x, y, and z represent a molar ratio of each element) are disclosed in, for example, Japanese Patent No. 3221132. Examples thereof include zinc antimonate (ZnSb ₂ O ₆ ) disclosed, indium antimonate (InSbO ₄ ) disclosed in Japanese Patent No. 3198494, and the like.
The zinc antimonate is marketed as, for example, a conductive sol (CELNAX series, manufactured by Nissan Chemical Industries, Ltd.), and can be easily obtained in a state of being dispersed in a solvent in a colloidal form. In addition, as a method for dispersing conductive fine particles obtained as a powder, an existing dispersion method can be used. For example, a microfluidizer (manufactured by MFI), an optimizer (manufactured by Sugino Machine), etc. The high-speed liquid collision dispersion method is suitable.
These conductive fine particles can be used alone or in combination of two or more.

The volume average particle size of the conductive fine particles is preferably 0.01 to 1 μm, and more preferably 0.01 to 0.5 μm. When the volume average particle size is less than 0.01 μm, the distance between the particles of the conductive fine particles contained in the outermost surface layer becomes small, which may be disadvantageous for maintaining the electrostatic charge on the surface. In addition, it becomes easy to form secondary particles with non-uniform particle sizes by agglomerating in the coating liquid, and as a result, localized in the layer as larger particles, resulting in abnormal images due to a decrease in the charged potential of the non-exposed area. That is, in the exposed area development method (negative positive method), granular background stains may occur, and in the non-exposed area development method (positive positive method), an abnormal image of white spots may occur. On the other hand, if the volume average particle size of the conductive fine particles exceeds 1 μm, the conductive fine particles with respect to the coating film may be too large, resulting in insufficient leveling of the surface. Roughness increases, and, for example, the followability of the blade to the surface of the electrostatic latent image carrier in the blade cleaning method is lowered, and cleaning failure may occur due to toner slipping. In particular, it is very disadvantageous for cleaning spherical toner, which is relatively difficult to clean with a blade. Moreover, there is a possibility of causing an abnormal image due to localization of large particles in the protective layer.
The conductive particles may be subjected to surface treatment with a known material or means as necessary.
The content of the conductive fine particles in the outermost surface layer is preferably 0.5 to 65% by mass, and more preferably 5 to 45% by mass. If the content is less than 0.5% by mass, the effect of reducing the non-uniformity of the crosslinking reaction may be insufficient, and the potential variation in the exposed area may not be suppressed. If the content exceeds 65% by mass, the outermost surface The bulk resistance of the layer may become too low, resulting in image blurring, the coating film becoming brittle, and wear resistance being reduced.

The outermost surface layer of the electrostatic latent image carrier is represented by M _x Sb _y O _z (where M represents a metal element, and x, y, and z represent a molar ratio of each element). Fine particles other than the conductive fine particles may be contained.
Examples of the fine particles include organic resin fine particles such as fluorine resin fine particles (eg, polytetrafluoroethylene), silicone resin fine particles, guanamine formaldehyde resin fine particles; metal powders such as copper, tin, aluminum, and indium; silica Metal oxides such as tin oxide, zinc oxide, titanium oxide, alumina, indium oxide, antimony oxide, bismuth oxide, calcium oxide, tin oxide doped with antimony, tin oxide doped indium oxide; tin fluoride Metal fluorides such as calcium fluoride and aluminum fluoride; inorganic fine particles such as potassium titanate and boron nitride; and the like. Among these, silica, alumina, titanium oxide, and tin oxide are particularly preferable because they have little influence on the electric characteristics of the electrostatic latent image carrier and can significantly improve the wear resistance.
When the fine particles are used in combination, the conductive fine particles represented by M _x Sb _y O _z (where M represents a metal element, and x, y, and z represent the molar ratio of each element). The content in the surface layer is preferably 10 to 100% by mass with respect to the total amount of fine particles. When the content of the conductive fine particles is less than 10% by mass, the effect of suppressing the unevenness of the exposed portion due to the conductive fine particles may be insufficient.

Next, the constituent material of the crosslinked surface layer of the present invention will be described.
The radical polymerizable monomer having a trivalent or higher radical polymerizable group having no charge transport property used in the present invention is a hole transport structure such as triarylamine, hydrazone, pyrazoline, carbazole, such as condensed polycyclic quinone. , A monomer having no electron transport structure such as diphenoquinone, an electron-withdrawing aromatic ring having a cyano group or a nitro group, and having three or more radically polymerizable functional groups. And the radical polymerizable functional group, a carbon - has a carbon double bond, it may be any the radical Le Polymerization groups.
Examples of these radical polymerizable functional groups include 1-substituted ethylene functional groups and 1,1-substituted ethylene functional groups shown below.
(1) Examples of the 1-substituted ethylene functional group include functional groups represented by the following formulas.

(In the formula, Y represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, an aryl group such as a substituted or unsubstituted phenyl group or a naphthyl group, a halogen atom, a cyano group, a nitro group, or a methoxy group. Group or an alkoxy group such as an ethoxy group, -COO R ₂ group ( R ₂ is a hydrogen atom, an alkyl group such as a substituted or unsubstituted methyl group or an ethyl group, an aralkyl group such as a substituted or unsubstituted benzyl or phenethyl group , An aryl group such as a substituted or unsubstituted phenyl group or a naphthyl group, or —CON R ₃ R ₄ (where R ₃ and R ₄ are a hydrogen atom, an alkyl group such as a substituted or unsubstituted methyl group or an ethyl group, a substituted group; Or an aralkyl group such as an unsubstituted benzyl group, naphthylmethyl group, or phenethyl group, or an aryl group such as a substituted or unsubstituted phenyl group or naphthyl group; May be the same or different from each other.) Further, X ₂ is identical substituents and a single bond and X ₁ in the formula 1 represents an alkylene group. However, Y, at least one of X ₂ is oxy A carbonyl group, a cyano group, an alkenylene group, and an aromatic ring.)

Specific examples of these substituents include an α-acryloyloxy chloride group, a methacryloyloxy group, an α-cyanoethylene group, an α-cyanoacryloyloxy group, an α-cyanophenylene group, and a methacryloylamino group.
In addition, examples of the substituent further substituted with the substituent for X ₁ , X ₂ , and Y include, for example, a halogen atom, a nitro group, a cyano group, a methyl group, an alkyl group such as an ethyl group, a methoxy group, an ethoxy group, and the like And an aryloxy group such as a phenoxy group, an aryl group such as a phenyl group and a naphthyl group, and an aralkyl group such as a benzyl group and a phenethyl group.
Among these radically polymerizable functional groups, acryloyloxy group and methacryloyloxy group are particularly useful. For example, a compound having three or more acryloyloxy groups is a compound having three or more hydroxyl groups in the molecule and an acrylic group. It can be obtained by using an acid (salt), an acrylic acid halide, or an acrylic ester to cause an ester reaction or a transesterification reaction. A compound having three or more methacryloyloxy groups can be obtained in the same manner. Further, the radical polymerizable functional groups in the monomer having three or more radical polymerizable functional groups may be the same or different.

Specific examples of the radical polymerizable monomer having a radical polymerizable group having no charge transporting structure and having three or more functional groups include the following, but are not limited to these compounds.
That is, examples of the radical polymerizable monomer used in the present invention include trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate, HPA-modified trimethylolpropane triacrylate, EO-modified trimethylolpropane triacrylate, and PO-modified. Trimethylolpropane triacrylate, caprolactone modified trimethylolpropane triacrylate, HPA modified trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate (PETTA), glycerol triacrylate, ECH modified glycerol triacrylate, EO modified glycerol triacrylate , PO-modified glycerol triacrylate, Lith (acryloxyethyl) isocyanurate, dipentaerythritol hexaacrylate (DPHA), caprolactone-modified dipentaerythritol hexaacrylate, dipentaerythritol hydroxypentaacrylate, alkyl-modified dipentaerythritol pentaacrylate, alkyl-modified dipentaerythritol tetraacrylate, alkyl Modified dipentaerythritol triacrylate, dimethylolpropane tetraacrylate (DTMPTA), pentaerythritol ethoxytetraacrylate, EO modified phosphoric acid triacrylate, 2,2,5,5-tetrahydroxymethylcyclopentanone tetraacrylate, etc. These may be used alone or in combination of two or more.

Further, the radical polymerizable monomer having a radical polymerizable group having no charge transporting structure and having three or more functional groups used in the present invention has a functional group in the monomer in order to form a dense crosslinked bond in the crosslinked surface layer. The ratio of molecular weight to the number of groups (molecular weight / number of functional groups) is preferably 250 or less. Further, when this ratio is larger than 250, the crosslinked surface layer is soft and wear resistance is somewhat lowered. Therefore, among the monomers exemplified above, monomers having a modifying group such as HPA, EO, and PO are extremely long. It is not preferable to use one having a modifying group alone. The proportion of the radical polymerizable monomer having a trivalent or higher radical polymerizable group having no charge transporting structure used for the crosslinked surface layer is 20 to 80% by mass , preferably 30 to 70%, based on the total amount of the crosslinked surface layer. % By mass . When the monomer component is less than 20% by mass, the three-dimensional cross-linking density of the cross-linked surface layer is small, and a drastic improvement in wear resistance is not achieved as compared with the case where a conventional thermoplastic binder resin is used. On the other hand, when the content is 80% by mass or more, the content of the charge transporting compound is lowered, and the electrical characteristics are deteriorated. Since the required wear resistance and electrical characteristics differ depending on the process used, it cannot be said unconditionally, but considering the balance of both characteristics, the range of 30 to 70% by mass is most preferable.

The radically polymerizable compound having a monofunctional charge transport structure used in the present invention is a hole transport structure such as triarylamine, hydrazone, pyrazoline, carbazole, such as condensed polycyclic quinone, diphenoquinone, cyano group, A compound having an electron transport structure such as an electron-withdrawing aromatic ring having a nitro group and having a radical polymerizable functional group. Examples of the radical polymerizable functional group include those shown in the above radical polymerizable monomer, and acryloyloxy group and methacryloyloxy group are particularly useful. As the charge transporting structure, a triarylamine structure is highly effective. Furthermore, when a compound represented by the following general formula (I) or (II) is used, electrical characteristics such as sensitivity and residual potential are favorably maintained.
(In the general formulas (I) and (II), R ₁₀ is a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a cyano group, or a nitro group. , An alkoxy group, —COO R ₁₁ ( R ₁₁ is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted aryl group), a carbonyl halide group, or CON R ₁₂ R _13. ( R ₁₂ and R ₁₃ represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted aryl group, and may be the same or different from each other. ) represents, _Ar 1, Ar ₂ represents a substituted or unsubstituted arylene group and may be the same or different. _Ar 3, Ar ₄ is also substituted Ku denotes an unsubstituted aryl group and may be the same or different. X ₁₀ represents a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene ether Represents a group, an oxygen atom, a sulfur atom, or a vinylene group, Z represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene ether group, or an alkyleneoxycarbonyl group, and m and n represent an integer of 0 to 3. .)

Specific examples of substituents in the general formulas (I) and (II) are shown below.
In the general formulas (I) and (II), in the substituent of R ₁₀ , examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group, and examples of the aryl group include a phenyl group and a naphthyl group. The aralkyl group includes a benzyl group, a phenethyl group, and a naphthylmethyl group, and the alkoxy group includes a methoxy group, an ethoxy group, a propoxy group, and the like. These include a halogen atom, a nitro group, a cyano group, and a methyl group. Substituted with an alkyl group such as an ethyl group, an alkoxy group such as a methoxy group or an ethoxy group, an aryloxy group such as a phenoxy group, an aryl group such as a phenyl group or a naphthyl group, an aralkyl group such as a benzyl group or a phenethyl group, etc. May be.
Among the substituents for R ₁₀ , particularly preferred are a hydrogen atom and a methyl group.
Ar ₃ and Ar ₄ are substituted or unsubstituted aryl groups, and examples of the aryl group include condensed polycyclic hydrocarbon groups, non-condensed cyclic hydrocarbon groups, and heterocyclic groups.

The condensed polycyclic hydrocarbon group preferably has 18 or less carbon atoms forming a ring, for example, a pentanyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptaenyl group, a biphenylenyl group, an as-indacenyl group. , S-indacenyl group, fluorenyl group, acenaphthylenyl group, preadenyl group, acenaphthenyl group, phenalenyl group, phenanthryl group, anthryl group, fluoranthenyl group, acephenanthrenyl group, aceanthrylenyl group, triphenylyl group, pyrenyl group , A chrycenyl group, a naphthacenyl group, and the like.
Examples of the non-fused cyclic hydrocarbon group include monovalent groups of monocyclic hydrocarbon compounds such as benzene, diphenyl ether, polyethylene diphenyl ether, diphenyl thioether and diphenyl sulfone, or biphenyl, polyphenyl, diphenylalkane, diphenylalkene, diphenylalkyne, Monovalent groups of non-condensed polycyclic hydrocarbon compounds such as triphenylmethane, distyrylbenzene, 1,1-diphenylcycloalkane, polyphenylalkane, and polyphenylalkene, or ring assemblies such as 9,9-diphenylfluorene And monovalent groups of hydrocarbon compounds.

Examples of the heterocyclic group include monovalent groups such as carbazole, dibenzofuran, dibenzothiophene, oxadiazole, and thiadiazole.
The aryl group represented by Ar ₃ or Ar ₄ may have a substituent as shown below, for example.
(1) Halogen atom, cyano group, nitro group and the like.
(2) An alkyl group. Preferably, it is a C1-C12, particularly C1-C8, more preferably a C1-C4 linear or branched alkyl group, and these alkyl groups further include a fluorine atom, a hydroxyl group, a cyano group, and a C1-C4 alkoxy group. , A phenyl group or a halogen atom, a C1-C4 alkyl group or a C1-C4 alkoxy group substituted with a phenyl group. Specifically, methyl group, ethyl group, n-butyl group, i-propyl group, t-butyl group, s-butyl group, n-propyl group, trifluoromethyl group, 2-hydroxyethyl group, 2-ethoxyethyl Group, 2-cyanoethyl group, 2-methoxyethyl group, benzyl group, 4-chlorobenzyl group, 4-methylbenzyl group, 4-phenylbenzyl group and the like.

(3) Alkoxy group (—O R ₁₄ ). R ₁₄ is the same as the alkyl group shown in (2). Specifically, methoxy group, ethoxy group, n-propoxy group, i-propoxy group, t-butoxy group, n-butoxy group, s-butoxy group, i-butoxy group, 2-hydroxyethoxy group, benzyloxy group And a trifluoromethoxy group.
(4) Aryloxy group. Examples of the aryl group of the aryloxy group include a phenyl group and a naphthyl group. This may contain a C1-C4 alkoxy group, a C1-C4 alkyl group or a halogen atom as a substituent. Specific examples include a phenoxy group, a 1-naphthyloxy group, a 2-naphthyloxy group, a 4-methoxyphenoxy group, and a 4-methylphenoxy group.
(5) Alkyl mercapto group or aryl mercapto group, and specific examples include methylthio group, ethylthio group, phenylthio group, p-methylphenylthio group and the like.
(6)
(In the formula, R ₁₅ and R ₁₆ each independently represent a hydrogen atom, the alkyl group shown in the above (2), or an aryl group. Examples of the aryl group include a phenyl group, a biphenyl group, and a naphthyl group. these C1~C4 alkoxy group, a C1~C4 alkyl group or a halogen atom may be contained as a substituent. _{R 15} and R ₁₆ may be linked to form a ring)
Specifically, amino group, diethylamino group, N-methyl-N-phenylamino group, N, N-diphenylamino group, N, N-di (tolyl) amino group, dibenzylamino group, piperidino group, morpholino group And pyrrolidino group.
(7) An alkylenedioxy group or an alkylenedithio group such as a methylenedioxy group or a methylenedithio group.
(8) A substituted or unsubstituted styryl group, a substituted or unsubstituted β-phenylstyryl group, a diphenylaminophenyl group, a ditolylaminophenyl group, and the like.

Examples of the arylene group represented by Ar ₁ and Ar ₂ include a divalent group derived from the aryl group represented by Ar ₃ and Ar ₄ .
X ₁₀ represents a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene ether group, an oxygen atom, a sulfur atom, or a vinylene group.
Examples of the substituted or unsubstituted alkylene group include C1-C12, preferably C1-C8, and more preferably C1-C4 linear or branched alkylene groups. These alkylene groups further include a fluorine atom and a hydroxyl group. , A cyano group, a C1-C4 alkoxy group, a phenyl group or a halogen atom, a C1-C4 alkyl group, or a phenyl group substituted with a C1-C4 alkoxy group. Specifically, methylene group, ethylene group, n-butylene group, i-propylene group, t-butylene group, s-butylene group, n-propylene group, trifluoromethylene group, 2-hydroxyethylene group, 2-ethoxyethylene Group, 2-cyanoethylene group, 2-methoxyethylene group, benzylidene group, phenylethylene group, 4-chlorophenylethylene group, 4-methylphenylethylene group, 4-biphenylethylene group and the like.
Examples of the substituted or unsubstituted cycloalkylene group include a C5-C7 cyclic alkylene group, and these cyclic alkylene groups include a fluorine atom, a hydroxyl group, a C1-C4 alkyl group, and a C1-C4 alkoxy group as a substituent. It may have a group. Specific examples include a cyclohexylidene group, a cyclohexylene group, and a 3,3-dimethylcyclohexylidene group.
Examples of the substituted or unsubstituted alkylene ether group include a —C H ₂ C H ₂ O— group, a —C H ₂ C H ₂ C H ₂ O— group, and a — (OC H ₂ C H ₂ ) h—O— group. , or _{- (OC H 2 C H 2} C H 2) i-O- group, and the like.
However, h and i in the above formula each represent an integer of 1 to 4.

The alkylene group of the alkylene ether group may have a substituent such as a hydroxyl group, a methyl group, or an ethyl group.
The vinylene group is
Represented by
R ₁₇ is hydrogen, an alkyl group (same as the alkyl group represented by (2) above), an aryl group (same as the aryl group represented by Ar ₃ or Ar ₄ above), a is 1 or 2, and b is 1 to 3 Represents.

Z represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene ether group, or an alkyleneoxycarbonyl group.
Examples of the substituted or unsubstituted alkylene group include the same alkylene groups as those described above for X.
Examples of the substituted or unsubstituted alkylene ether group include the alkylene ether group represented by X.
Examples of the alkyleneoxycarbonyl group include a caprolactone-modified group.

Further, the radically polymerizable compound having a monofunctional charge transport structure of the present invention is more preferably a compound having the structure of the following general formula (III).
(In the formula, o, p and q are each an integer of 0 or 1, Ra represents a hydrogen atom or a methyl group, Rb and Rc represent substituents other than a hydrogen atom and represent an alkyl group having 1 to 6 carbon atoms, and are the same. S and t each represents an integer of 0 to 3. Za is a single bond, a methylene group, an ethylene group,
Represents. )
As the compound represented by the general formula (III), a compound having a methyl group or an ethyl group as a substituent for Rb and Rc is particularly preferable.

The crosslinked surface layer formed according to the present invention is free from cracks and has excellent electrical characteristics. The reason is that the radically polymerizable compound having a monofunctional charge transport structure represented by the general formulas (I) and (II), particularly (III) used in the present invention, has a carbon-carbon double bond open on both sides. In the polymer in which the terminal structure is not formed and is incorporated into the chain polymer, and the radical polymerizable group is crosslinked by polymerization with a radical polymerizable monomer having three or more functional groups , Present in the main chain and present in the cross-linked chain between the main chain and main chain (this cross-linked chain is intermolecular cross-linked between one polymer and the other polymer and folded within one polymer. When there is an intramolecular cross-linked chain that crosslinks a part of the main chain in a separated state and another part derived from the polymerized monomer at a position away from this in the main chain) Or if it is present in a cross-linked chain The reelamine structure has at least three aryl groups arranged in a radial direction from the nitrogen atom and is bulky, but is not directly bonded to the chain part but is suspended from the chain part via a carbonyl group or the like. Therefore, since these triarylamine structures can be arranged in the polymer in a space that is reasonably adjacent to each other because they are fixed in a state where there is flexibility in steric positioning, there is little structural distortion in the molecule, and When the surface layer of the latent electrostatic image bearing member is used, it is presumed that an intramolecular structure that is relatively free from interruption of the charge transport path can be adopted.

  Specific examples of the radically polymerizable compound having a monofunctional charge transporting structure of the present invention are shown below, but are not limited to the compounds having these structures.

Specific examples of the radical polymerizable compound having a bifunctional charge transporting structure of the present invention are shown below, but are not limited to the compounds having these structures.

Specific examples of the radically polymerizable compound in which the radically polymerizable group of the present invention has a trifunctional charge transporting structure are shown below, but are not limited to compounds having these structures.

Further, the radical polymerizable compound having a charge transporting structure used in the present invention is important for imparting the charge transport performance of the crosslinked surface layer, and this component is preferably 20 to 80% by mass , preferably based on the total amount of the crosslinked surface layer. Is 30-70 mass %. If this component is less than 20% by mass, the charge transport performance of the crosslinked surface layer cannot be maintained sufficiently, and deterioration of electrical characteristics such as a decrease in sensitivity and an increase in residual potential appear with repeated use. On the other hand, if it exceeds 80% by mass , the content of the trifunctional monomer having no charge transport structure is lowered, and the crosslink density is lowered, so that high wear resistance is not exhibited. Although the electrical characteristics and wear resistance required by the process used are different, it cannot be said unconditionally, but the range of 30 to 70% by mass is most preferable considering the balance of both characteristics.
The surface layer of the present invention is obtained by curing a radical polymerizable monomer having at least a trifunctional or higher radical polymerizable monomer having no charge transport structure and a radical polymerizable compound having a charge transport structure. Monofunctional and bifunctional radically polymerizable monomers and radically polymerizable oligomers can be used in combination for the purpose of imparting functions such as viscosity adjustment during coating, stress relaxation of the cross-linked surface layer, lower surface energy and reduced friction coefficient. . Known radical polymerizable monomers and oligomers can be used.

Examples of the monofunctional radical monomer include 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, tetrahydrofurfuryl acrylate, 2-ethylhexyl carbitol acrylate, 3-methoxybutyl acrylate, benzyl acrylate, and cyclohexyl acrylate. , Isoamyl acrylate, isobutyl acrylate, methoxytriethylene glycol acrylate, phenoxytetraethylene glycol acrylate, cetyl acrylate, isostearyl acrylate, stearyl acrylate, styrene monomer, and the like.
Examples of the bifunctional radical polymerizable monomer include 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1, Examples include 6-hexanediol dimethacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, EO-modified bisphenol A diacrylate, EO-modified bisphenol F diacrylate, and neopentyl glycol diacrylate.

Examples of the functional monomer include those substituted with a fluorine atom such as octafluoropentyl acrylate, 2-perfluorooctylethyl acrylate, 2-perfluorooctylethyl methacrylate, 2-perfluoroisononylethyl acrylate, No. 60503, JP-B-6-45770, siloxane repeating units: 20-70 acryloyl polydimethylsiloxane ethyl, methacryloyl polydimethylsiloxane ethyl, acryloyl polydimethylsiloxane propyl, acryloyl polydimethylsiloxane butyl, diacryloyl polydimethylsiloxane Examples include vinyl monomers having a polysiloxane group such as diethyl, acrylates and methacrylates.
Examples of the radical polymerizable oligomer include epoxy acrylate, urethane acrylate, and polyester acrylate oligomers. However, when a large amount of monofunctional and bifunctional radically polymerizable monomers and radically polymerizable oligomers are contained, the three-dimensional cross-linking density of the cross-linked surface layer is substantially reduced, resulting in a decrease in wear resistance. For this reason, the content of these monomers and oligomers is limited to 50 parts by mass or less, preferably 30 parts by mass or less, with respect to 100 parts by mass of the radical polymerizable monomer having a radical polymerizable group of 3 or more functional groups .

Further, the surface layer of the present invention is obtained by curing a radical polymerizable monomer having a radical polymerizable group having at least a trifunctional functional group having no charge transporting structure and a charge transporting structure. Accordingly, a polymerization initiator may be used in the crosslinked surface layer in order to allow the crosslinking reaction to proceed efficiently.
Further, the surface layer of the present invention is obtained by curing a radical polymerizable monomer having a radical polymerizable group having at least a trifunctional functional group having no charge transporting structure and a charge transporting structure. Accordingly, a polymerization initiator may be used in the crosslinked surface layer in order to allow the crosslinking 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, peroxide initiators such as lauroyl peroxide, azobisisobutylnitrile, azobiscyclohexanecarbonitrile Azo initiators such as methyl azobisisobutyrate, azobisisobutylamidine hydrochloride, 4,4′-azobis-4-cyanovaleric acid.

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. Content of a polymerization initiator is 0.5-40 mass parts with respect to 100 mass parts of total inclusions which have radical polymerizability, Preferably it is 1-20 mass parts.

Furthermore, the coating liquid of the present invention can contain additives such as various plasticizers (for the purpose of stress relaxation and adhesion improvement), leveling agents, and low molecular charge transport materials having no radical reactivity as required. As these additives, known additives can be used, and as plasticizers, those used in general resins such as dibutyl phthalate and dioctyl phthalate can be used, and the amount used is the total solid content of the coating liquid. To 20% by mass or less, preferably 10 % by mass or less. As leveling agents, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, polymers or oligomers having a perfluoroalkyl group in the side chain can be used, and the amount used is based on the total solid content of the coating solution 3% by mass or less is appropriate.

The crosslinked surface layer of the present invention comprises a radical polymerizable monomer having at least a trifunctional or higher radical polymerizable group having no charge transport structure, a radical polymerizable compound having a charge transport structure, and the following formula: M _x Sb _y O _z ( However, M represents a metal element, x, y, and z represent the molar ratio of each element.) Applying and hardening the coating liquid containing at least 1 type of electroconductive fine particle represented by these. It is formed by. When the radically polymerizable monomer is a liquid, such a coating liquid can be applied by dissolving other components in the liquid, but if necessary, it is diluted with a solvent and applied. Solvents used at this time include alcohols such as methanol, ethanol, propanol and butanol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, esters such as ethyl acetate and butyl acetate, tetrahydrofuran, dioxane and propyl ether. And ethers such as dichloromethane, dichloroethane, trichloroethane, and chlorobenzene, aromatics such as benzene, toluene, and xylene, and cellosolves such as methyl cellosolve, ethyl cellosolve, and cellosolve acetate. These solvents may be used alone or in combination of two or more. The dilution ratio with the solvent varies depending on the solubility of the composition, the coating method, and the target film thickness, and is arbitrary. The coating can be performed using a dip coating method, spray coating, bead coating, ring coating method or the like.

  In the present invention, after applying such a coating liquid, light energy is applied from the outside and cured to form a crosslinked surface layer. 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. Further, the reactivity of the crosslinking reaction by radical polymerization is greatly affected by the temperature, and it is preferable to maintain the surface temperature of the photosensitive member at 20 ° C. or higher and 170 ° C. or lower during light irradiation. The photoreceptor surface temperature control means may be any method as long as the above temperature range can be maintained, but a method of controlling the temperature using a heat medium is preferable.

In the case of using the crosslinked surface layer forming material of the present invention , examples of the coating method include, for example, an acrylate monomer having three acryloyloxy groups and a triarylamine compound having one acryloyloxy group as a coating solution. Are used in a ratio of 7: 3 to 3: 7, and a polymerization initiator is added in an amount of 3 to 20% by mass with respect to the total amount of these acrylate compounds. To prepare a coating solution. For example, in the case where the charge transport layer which is the lower layer of the cross-linked surface layer uses a triarylamine donor as the charge transport material and polycarbonate as the binder resin, and the cross-linked surface layer is formed by spray coating, the above coating solution As the solvent, tetrahydrofuran, 2-butanone, ethyl acetate and the like are preferable, and the use ratio thereof is 3 to 10 times the total amount of the acrylate compound.
The cured surface crosslinked layer is preferably insoluble in an organic solvent. A film that is not sufficiently cured is soluble in an organic solvent and has a low crosslink density, so that the mechanical durability is also low.

Next, for example, the prepared coating solution is applied by spraying etc. on a photoreceptor in which an undercoat layer, a charge generation layer, and the above charge transport layer are sequentially laminated on a support such as an aluminum cylinder, and dry to the touch. Then, it is cured by light irradiation.

For UV irradiation, uses a metal halide lamp, illuminance 50 mW / cm ² or more, preferably 1000 mW / cm ² or less, for example, the case of irradiation with UV light of 700 mW / cm ^2, for example upon curing, by rotating the drum Irradiate all surfaces uniformly for about 2 minutes. At this time, control is performed using a heat medium or the like so that the surface temperature does not become too high.

After completion of curing, the photosensitive member of the present invention is obtained by heating at 100 to 150 ° C. for 10 to 30 minutes to reduce the residual solvent.
The thickness of the outermost layer of the present invention is preferably 0.5 to 50 μm, more preferably 1 to 40 μm, and further preferably 2 to 20 μm.
If the thickness is less than 0.5 μm, the margin for disappearance or scratches due to wear is too small and sufficient durability cannot be ensured in many cases. On the other hand, if it is thicker than 50 μm, it may cause problems such as an increase in residual potential. Therefore, it is necessary to form the outermost layer with a suitable film thickness so as to secure a margin for wear and scratches and reduce the occurrence of residual potential.

[Photosensitive layer]
Next, the multilayer type photosensitive layer and the single layer type photosensitive layer constituting the electrostatic latent image carrier of the present invention will be described.
<Multi-layer type photosensitive layer>
The multilayer type photosensitive layer is usually formed by laminating a charge generation layer (CGL) and a charge transport layer (CTL) in this order on a support.
(Charge generation layer)
The charge generation layer contains at least a charge generation material, and includes a binder resin and, if necessary, other components.
There is no restriction | limiting in particular as a charge generation substance, Although it can select suitably according to the objective, Either an inorganic material and an organic material can be used.
Examples of the inorganic material include, but are not limited to, crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, and selenium-arsenic compounds.
Examples of the organic material include, but are not limited to, phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine, azulenium salt pigments, squaric acid methine pigments, azo pigments having a carbazole skeleton, and triphenylamine skeletons. Azo pigments, azo pigments having a diphenylamine skeleton, azo pigments having a dibenzothiophene skeleton, azo pigments having a fluorenone skeleton, azo pigments having an oxadiazole skeleton, azo pigments having a bisstilbene skeleton, having a distyryl oxadiazole skeleton Azo pigments, azo pigments having a distyrylcarbazole skeleton, perylene pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane or triphenylmethane pigments, benzoquinone or naphthalene Tokinon pigments, cyanine and azomethine pigments, indigoid pigments, bisbenzimidazole pigments, and the like. These may be used individually by 1 type and may use 2 or more types together.

The binder resin for the charge generation layer is not particularly limited and can be appropriately selected depending on the purpose. For example, polyamide resin, polyurethane resin, epoxy resin, polyketone resin, polycarbonate resin, silicone resin, acrylic resin, polyvinyl butyral resin , Polyvinyl formal resin, polyvinyl ketone resin, polystyrene resin, poly-N-vinyl carbazole resin, polyacrylamide resin, and the like. These may be used individually by 1 type and may use 2 or more types together.
In addition, you may add a charge transport material as needed. In addition to the binder resin described above, a polymer charge transport material can be added as the binder resin for the charge generation layer.
As a method for forming the charge generation layer, a vacuum thin film preparation method and a casting method from a solution dispersion system can be mentioned.
Examples of the former method include a glow discharge polymerization method, a vacuum deposition method, a CVD method, a sputtering method, a reactive sputtering method, an ion plating method, and an accelerated ion injection method. This vacuum thin film manufacturing method can satisfactorily form the inorganic material or organic material described above.
In order to provide the charge generation layer by the latter casting method, a charge generation layer forming coating solution is used and a conventional method such as a dip coating method, spray coating, or bead coating method is used. it can.

Examples of the organic solvent used in the charge generation layer forming coating solution include acetone, methyl ethyl ketone, methyl isopropyl ketone, cyclohexanone, benzene, toluene, xylene, chloroform, dichloromethane, dichloroethane, dichloropropane, trichloroethane, trichloroethylene, tetrachloroethane, Examples include tetrahydrofuran, dioxolane, dioxane, methanol, ethanol, isopropyl alcohol, butanol, ethyl acetate, butyl acetate, dimethyl sulfoxide, methyl cellosolve, ethyl cellosolve, propyl cellosolve, and the like. These may be used individually by 1 type and may use 2 or more types together.
Among these, tetrahydrofuran, methyl ethyl ketone, dichloromethane, methanol, and ethanol having a boiling point of 40 ° C. to 80 ° C. are particularly preferable because they can be easily dried after coating.

The coating solution for forming a charge generation layer can be produced by dispersing and dissolving the charge generation material and a binder resin in the organic solvent. Examples of the method for dispersing the organic pigment in the organic solvent include a dispersion method using a dispersion medium such as a ball mill, a bead mill, a sand mill, and a vibration mill, and a high-speed liquid collision dispersion method.
Depending on the thickness of the charge generation layer, the electrophotographic characteristics, particularly the photosensitivity, change. Generally, the thicker the thickness, the higher the photosensitivity. Therefore, the thickness of the charge generation layer is preferably set in a suitable range according to the required specification of the image forming apparatus. In order to obtain the sensitivity required for the electrophotographic photosensitive member. Usually, 0.01 to 5 μm is preferable, and 0.05 to 2 μm is more preferable.

(Charge transport layer)
It is placed the present invention, if the charge transport layer is the outermost layer, as described above, a radical having no in electrostatic latent image bearing member having at least a photosensitive layer, a surface layer of the photosensitive layer is at least a charge transport structure It consists of a crosslinked layer obtained by curing a radically polymerizable monomer having a trifunctional or higher functional group and a radically polymerizable compound having a charge transporting structure, and the crosslinked surface layer has the following formula: M _x Sb _y O _z (where M Represents a metal element, and x, y, and z represent the molar ratio of each element).
However, when the outermost surface layer is a protective layer formed on the charge transport layer, the wear resistance of the charge transport layer may be low. In order to achieve the purpose of holding the charged charge, it is required that the electric resistance is high. Further, in order to achieve the purpose of obtaining a high surface potential with the charged charge that has been held, it is required that the dielectric constant is small and the charge mobility is good.

  Examples of the hole transport material (electron donating material) include oxazole derivatives, oxadiazole derivatives, imidazole derivatives, triphenylamine derivatives, 9- (p-diethylaminostyrylanthracene), 1,1-bis- (4- Dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazoline, phenylhydrazones, α-phenylstilbene derivatives, thiazole derivatives, triazole derivatives, phenazine derivatives, acridine derivatives, benzofuran derivatives, benzimidazole derivatives, thiophene derivatives, etc. . These may be used individually by 1 type and may use 2 or more types together.

On the other hand, examples of the polymer charge transport material include those having the following structure.
(A) Polymer having carbazole ring For example, poly-N-vinylcarbazole, JP-A-50-82056, JP-A-54-9632, JP-A-54-11737, JP-A-4-175337 And the compounds described in JP-A-4-183719 and JP-A-6-234841.
(B) Polymer having a hydrazone structure For example, JP-A-57-78402, JP-A-61-20953, JP-A-61-296358, JP-A-1-134456, JP-A-1-134456 179164, JP-A-3-180851, JP-A-3-180852, JP-A-3-50555, JP-A-5-310904, JP-A-6-234840, and the like. Is done.
(C) Polysilylene polymer For example, JP-A-63-285552, JP-A-1-88461, JP-A-4-264130, JP-A-4-264131, JP-A-4-264132, Examples thereof include compounds described in Kaihei 4-264133 and JP-A-4-289867.
(D) Polymer having a triarylamine structure For example, N, N-bis (4-methylphenyl) -4-aminopolystyrene, JP-A-1-134457, JP-A-2-282264, JP-A-2- Examples include compounds described in JP-A-304456, JP-A-4-133605, JP-A-4-133066, JP-A-5-40350, and JP-A-5-202135.
(E) Other polymers For example, formaldehyde condensation polymer of nitropyrene, JP-A-51-73888, JP-A-56-150749, JP-A-6-234836, JP-A-6-234837 The described compounds and the like are exemplified.

In addition to the above, the polymer charge transport material includes, for example, a polycarbonate resin having a triarylamine structure, a polyurethane resin having a triarylamine structure, a polyester resin having a triarylamine structure, and a polyarylamine structure having a polyarylamine structure. And ether resins. Examples of the polymer charge transporting material include JP-A 64-1728, JP-A 64-13061, JP-A 64-19049, JP-A-4-11627, JP-A 4-116627. JP 2225014, JP 4-230767, JP 4-320420, JP 5-232727, JP 7-56374, JP 9-127713, JP 9-222740. And compounds described in JP-A-9-265197, JP-A-9-211877, JP-A-9-30495, and the like.
Examples of the polymer having an electron donating group include not only the above-mentioned polymers but also copolymers with known monomers, block polymers, graft polymers, star polymers, and further, for example, A cross-linked polymer having an electron donating group as disclosed in Japanese Patent No. 109406 can also be used.

Examples of the binder resin for the charge transport layer include polycarbonate resin, polyester resin, methacrylic resin, acrylic resin, polyethylene resin, polyvinyl chloride resin, polyvinyl acetate resin, polystyrene resin, phenol resin, epoxy resin, polyurethane resin, and polychlorinated resin. Vinylidene resin, alkyd resin, silicone resin, polyvinyl carbazole resin, polyvinyl butyral resin, polyvinyl formal resin, polyacrylate resin, polyacrylamide resin, phenoxy resin, and the like are used. These may be used individually by 1 type and may use 2 or more types together.
The charge transport layer may also contain a copolymer of a crosslinkable binder resin and a crosslinkable charge transport material.
The charge transport layer can be formed by dissolving or dispersing the charge transport material and the binder resin in an appropriate solvent, and applying and drying the solution on the charge generation layer. In addition to the charge transport material and the binder resin, an appropriate amount of additives such as a plasticizer, an antioxidant, and a leveling agent can be added to the charge transport layer as necessary.
The thickness of the charge transport layer is preferably 5 to 100 μm. In recent years, the charge transport layer has been made thinner to meet the demand for higher image quality. To achieve a higher image quality of 1200 dpi or more, More preferably, it is ˜30 μm.

Next, the single layer type photosensitive layer will be described.
<Single layer type photosensitive layer>
The single-layer type photosensitive layer contains a charge generation material, a charge transport material, a binder resin, and other components as necessary.
When a single-layer photosensitive layer is provided by a casting method, such a single-layer photosensitive layer can be prepared by, for example, dissolving at least a charge generation material, a thermosetting binder resin, and a charge transport material having a crosslinkable functional group in an appropriate solvent. It can be formed by dispersing, coating and drying. In addition, a plasticizer can be added to the single-layer photosensitive layer as necessary.
The thickness of the single-layer type photosensitive layer is preferably 5 to 100 μm, and more preferably 5 to 50 μm. When the film thickness is less than 5 μm, the chargeability may decrease, and when it exceeds 100 μm, the sensitivity may decrease.

[Support]
The support in the electrostatic latent image carrier of the present invention is not particularly limited as long as it has conductivity, and can be appropriately selected according to the purpose.
As the support, a conductor or an insulator subjected to a conductive treatment is suitable. For example, a metal such as Al, Ni, Fe, Cu, or Au, or an alloy thereof; insulating properties such as polyester, polycarbonate, polyimide, and glass A substrate in which a metal such as Al, Ag, Au, or a conductive material such as In ₂ O ₃ or SnO ₂ is formed on a substrate; carbon black, graphite, metal powder such as Al, Cu, Ni, etc. Examples thereof include a resin substrate in which conductive glass powder and the like are uniformly dispersed to impart conductivity to the resin, and paper subjected to a conductive treatment.
There is no restriction | limiting in particular as a shape and a magnitude | size of a support body, Any of plate shape, drum shape, or belt shape can be used. When a belt-like support is used, there is an advantage that the apparatus becomes complicated and the size is increased while it is necessary to provide a driving roller and a driven roller inside, but the degree of freedom in layout is increased. However, when the protective layer is formed, the protective layer is not flexible enough to cause a crack called a crack on the surface, which may cause a granular background stain. . For this reason, a drum-like thing with high rigidity is suitable as a support.
An undercoat layer may be provided between the support and the photosensitive layer as necessary. The undercoat layer is provided for the purpose of improving adhesiveness, preventing moire, improving the coatability of the upper layer, and reducing the residual potential.

The undercoat layer generally contains a resin as a main component, but these resins are resins having high resistance to dissolution in general organic solvents in consideration of applying a photosensitive layer thereon with a solvent. It is preferable. 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 resins, alkyd-melamine resins, and epoxy resins. And a curable resin that forms a three-dimensional network structure.
Further, fine powders such as metal oxides exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide and the like, or metal sulfides and metal nitrides may be added. These undercoat layers can be formed by a conventional coating method using an appropriate solvent.
As the undercoat layer, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like is used, for example, a metal oxide layer formed by a sol-gel method or the like, and Al ₂ O ₃ is anodized. In addition, an organic material such as polyparaxylylene (parylene), an inorganic material such as SnO ₂ , TiO ₂ , ITO, or CeO ₂ provided by a vacuum thin film manufacturing method can be used.
There is no restriction | limiting in particular in the thickness of an undercoat layer, According to the objective, it can select suitably, 0.1-10 micrometers is preferable and 1-5 micrometers is more preferable.

In the electrostatic latent image carrier of the present invention, so-called photoconductor, an intermediate layer may be provided on the support, if necessary, in order to improve adhesion and charge blocking properties. In general, the intermediate layer is mainly composed of a resin. However, considering that the photosensitive layer is formed by applying a solution containing a solvent on the resin, a resin having a high solvent resistance with respect to a general organic solvent. It is desirable that
Examples of the intermediate layer resin include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane resins, melamine resins, phenol resins, and alkyd-melamines. Examples thereof include curable resins that form a three-dimensional network structure, such as resins and epoxy resins.

Next, the image forming apparatus and the image forming method of the present invention will be described.
That is, the image forming apparatus of the present invention comprises a support and an electrostatic latent image carrier having at least a photosensitive layer on the support, wherein the surface layer of the photosensitive layer has at least a charge transporting structure . It consists of a crosslinked layer obtained by curing a radically polymerizable monomer having a trifunctional or higher functional group and a radically polymerizable compound having a charge transporting structure, and the crosslinked surface layer has the following formula: M _x Sb _y O _z (where M is An electrostatic latent image carrier characterized by containing at least one conductive fine particle represented by: x, y, and z each represents a molar ratio of each element; Electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, developing means for converting the electrostatic latent image into a visible image using toner, and transferring the visible image to a recording medium At least a transfer means for fixing and a fixing means for fixing the transferred image And wherein the door.
The image forming apparatus of the present invention may have other means appropriately selected as necessary, for example, a static elimination means, a cleaning means, a recycling means, a control means, and the like.
As the cleaning unit, for example, a cleaning unit that contacts the surface of the electrostatic latent image carrier and removes toner remaining on the surface of the electrostatic latent image carrier is preferably used.

The image forming method of the present invention can be preferably carried out by the image forming apparatus of the present invention, the electrostatic latent image forming step can be performed by an electrostatic latent image forming unit, and the developing step can be performed by a developing unit. The transfer step can be performed by a transfer unit, the fixing step can be performed by a fixing unit, and the other steps can be performed by other units.
That is, the image forming method of the present invention is a radical polymerization property in which the surface layer of the photosensitive layer has at least a charge transporting structure in the support and the electrostatic latent image carrier having at least the photosensitive layer on the support . It consists of a crosslinked layer obtained by curing a radically polymerizable monomer having a trifunctional or higher functional group and a radically polymerizable compound having a charge transporting structure, and the crosslinked surface layer has the following formula: M _x Sb _y O _z (where M is An electrostatic latent image carrier characterized by containing at least one conductive fine particle represented by: x, y, and z each represents a molar ratio of each element; Electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, developing means for converting the electrostatic latent image into a visible image using toner, and transferring the visible image to a recording medium And at least a fixing unit for fixing the transferred image. It is characterized in.

Furthermore, other processes appropriately selected as necessary, for example, a static elimination process, a cleaning process, a recycling process, a control process, and the like can be included.
Hereinafter, each process and means will be described in detail.
<Electrostatic latent image forming step and electrostatic latent image forming means>
The electrostatic latent image forming step is a step of forming an electrostatic latent image on a charged electrostatic latent image carrier by exposure, and the electrostatic latent image carrier of the present invention is used as the electrostatic latent image carrier. Used. The electrostatic latent image forming unit includes a charger and an exposure device.
Charging can be performed, for example, by applying a voltage to the surface of the electrostatic latent image carrier using a charger. There is no restriction | limiting in particular as a charger used, According to the objective, it can select suitably. For example, a known contact charger equipped with a conductive or semiconductive roller, brush, film, rubber blade, etc., a non-contact charger using corona discharge such as corotron, scorotron, a gap tape at the end of the roller, etc. Examples thereof include a charger provided with a means for providing a gap and disposed in close proximity to the electrostatic latent image carrier via the gap tape.

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 a magnetic brush, for example, various ferrite particles such as Zn-Cu ferrite are used as a charging member, a non-magnetic conductive sleeve for supporting the charging member, and a magnetic roll included in the charging member, To do. Alternatively, in the case of a brush, for example, a fur treated with carbon, copper sulfide, metal or metal oxide is used as the material of the fur brush, and this is wound around a metal or other conductive core. A charging member is obtained by pasting.
As the charger, it is possible to obtain an image forming apparatus in which ozone generation from the charger is reduced by using a contact-type charger or a charger arranged in a non-contact manner by means for providing a gap. To preferred. In particular, it is preferable that the charger is arranged in contact with or not in contact with the electrostatic latent image carrier and is configured to charge the surface of the electrostatic latent image carrier by the superimposed application of DC and AC voltages.
The charger is a charging roller that is disposed in close proximity to the electrostatic latent image carrier via a gap tape, and the surface of the electrostatic latent image carrier is applied by superimposing a direct current and an alternating voltage on the charging roller. Is particularly preferable since it has a great merit that it can be used free of maintenance because it has a large margin for charging unevenness due to the charging roller and contamination due to dirt on the charging roller.

The exposure can be performed, for example, by exposing the surface of the electrostatic latent image carrier imagewise using an exposure device.
The exposure device is not particularly limited as long as the surface of the electrostatic latent image carrier charged by the charger can be exposed like the image to be formed, and can be appropriately selected according to the purpose.
Examples thereof include 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.
In the present invention, a back light system in which imagewise exposure is performed from the back side of the electrostatic latent image carrier may be employed.

<Development process and development means>
The developing step is a step of developing a latent image formed by exposure with a toner to form a visible image. The “toner” here includes a toner and a developer described later.
That is, the visible image is formed by a developing unit, and can be performed by developing the electrostatic latent image with toner or developer.
The developing means is not particularly limited as long as it can be developed using toner or developer, and can be appropriately selected from known ones. For example, toner or developer is accommodated and an electrostatic latent image is formed. Preferable examples include those having at least a developing unit capable of applying the toner or developer in contact or non-contact.
The developing device may be either a dry developing method or a wet developing method, and may be either a single color developing device or a multicolor developing device. For example, a toner having a stirrer for charging a toner or a developer by friction stirring and a rotatable magnet roller can be preferably used.
In the developing device, for example, a toner and a carrier, which will be described later, are mixed and agitated, 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 electrostatic latent image carrier (photosensitive member), a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is part of the photosensitive member by electric attraction force. Move to the surface. As a result, the electrostatic latent image is developed with toner, and a visible image with toner is formed on the surface of the photoreceptor.
The developer stored in the developing device may be a one-component developer or a two-component developer.

<Transfer process and transfer means>
The transfer process is a process of transferring a visible image to a recording medium. As the transfer step, an embodiment in which an intermediate transfer member is used, a visible image is primarily transferred onto the intermediate transfer member, and then the visible image is secondarily transferred onto the recording medium is preferable. Includes a primary transfer step in which a full color toner is used to transfer a visible image onto an intermediate transfer member to form a composite transfer image, and a secondary transfer step in which the composite transfer image is transferred onto a recording medium. Is more preferable.
The transfer is performed by, for example, charging a visible image with an electrostatic latent image carrier (photoconductor) with a transfer charger, and this can be performed by a transfer unit. The transfer means includes a primary transfer means for transferring a visible image onto an intermediate transfer member to form a composite transfer image, and a secondary transfer means for transferring the composite transfer image onto a recording medium. Embodiments are preferred.
That is, the developing unit forms a single color toner image on each of the plurality of electrostatic latent image carriers, and the transfer unit sequentially superimposes the formed color toner images on the intermediate transfer member. It is preferable that the transfer is performed, and the obtained primary transfer image is collectively transferred onto the recording medium. The intermediate transfer member is not particularly limited and may be appropriately selected from known transfer members according to the purpose. A suitable example is a transfer belt.

The static friction coefficient of the intermediate transfer member is preferably from 0.1 to 0.6, more preferably from 0.3 to 0.5.
The volume resistance of the intermediate transfer member is preferably from several Ωcm to 10 ³ Ωcm. When the volume resistance is set to several Ωcm or more and 10 ³ Ωcm or less, the intermediate transfer member itself is prevented from being charged, and the charge imparted by the charge imparting means hardly remains on the intermediate transfer member. Transfer unevenness can be prevented.
Further, it is possible to easily apply a transfer bias at the time of secondary transfer.

The material of the intermediate transfer member is not particularly limited and can be appropriately selected from known materials according to the purpose. For example, the following is exemplified.
(1) Material using a high Young's modulus (tensile elastic modulus) as a single-layer belt: As a material having a high Young's modulus, PC (polycarbonate), PVDF (polyvinylidene fluoride), PAT (polyalkylene terephthalate), PC (Polycarbonate) / PAT (polyalkylene terephthalate) blend material, ETFE (ethylene tetrafluoroethylene copolymer) / PC blend material, ETFE / PAT blend material, PC / PAT blend material, thermal curing of carbon black dispersion For example, a functional polyimide. These single-layer belts having a high Young's modulus have the advantage that the amount of deformation with respect to stress during image formation is small, and registration is not likely to occur particularly during color image formation.
(2) A belt having a two- or three-layer structure in which a belt having a high Young's modulus is used as a base layer, and a surface layer or an intermediate layer is provided on the outer periphery of the belt. It has a performance that can prevent the generated line image from being lost.
(3) Belts having a relatively low Young's modulus using rubber and elastomer: These belts have an advantage that almost no void in the line image occurs due to their softness. In addition, the belt width is made larger than that of the drive roll and the tension roll, and the elasticity of the belt ear protruding from the roll is used to prevent meandering, so that a low cost can be realized without the need for ribs or meandering prevention devices. .

Conventionally, fluorine-based resin, polycarbonate resin, polyimide resin, and the like have been used for the intermediate transfer belt. However, in recent years, an elastic belt in which the entire belt layer or a part of the belt is used as an elastic member has been used.
That is, in the case of transferring a color image using a resin belt, there are the following problems.
A color image is usually formed with four colored toners, and one to four toner layers are formed on a single color image. The toner layer is subjected to primary transfer (from a photoreceptor to an intermediate transfer belt). ) And secondary transfer (transfer from the intermediate transfer belt to the sheet), the pressure of the toner increases and the cohesive force between the toners increases. Is likely to occur. Since the resin belt has a high hardness and does not deform according to the toner layer, the toner layer is easily compressed, and the character dropout phenomenon is likely to occur.

In the case of an elastic belt, attention is paid to the fact that it deforms in correspondence with the toner layer in the transfer section and paper with poor smoothness. In other words, since the elastic belt deforms following local irregularities, it is possible to obtain a good adhesion without excessively increasing the transfer pressure with respect to the toner layer, and a paper with poor flatness that has no void in characters. In contrast, a transfer image with excellent uniformity can be obtained.
Examples of the resin used for the elastic belt include polycarbonate, fluororesin (ETFE, PVDF), polystyrene resin, chloropolystyrene resin, poly-α-methylstyrene resin, styrene-butadiene copolymer, and styrene-vinyl chloride copolymer. Styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer (for example, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-acrylic) Acid butyl copolymer, styrene-octyl acrylate copolymer, styrene-phenyl acrylate copolymer, etc.), styrene-methacrylic acid ester copolymer (for example, styrene-methyl methacrylate copolymer, styrene-methacrylic acid) Ethyl copolymer, styrene-metac Styrene resins (monopolymer or copolymer containing styrene or styrene-substituted product) such as phenyl acrylate copolymer), styrene-α-methyl chloroacrylate copolymer, styrene-acrylonitrile-acrylate ester copolymer, etc. Coalesced), methyl methacrylate resin, butyl methacrylate resin, ethyl acrylate resin, butyl acrylate resin, modified acrylic resin (for example, silicone modified acrylic resin, vinyl chloride resin modified acrylic resin, acrylic / urethane resin, etc.), polychlorinated Vinyl resin, styrene-vinyl acetate copolymer, vinyl chloride-vinyl acetate copolymer, rosin-modified maleic acid resin, phenol resin, epoxy resin, polyester resin, polyester polyurethane resin, polyethylene, polypropylene, polybutadiene, polyvinylidene chloride, acrylic resin Ionomer resins, polyurethane resins, silicone resins, ketone resins, ethylene - ethyl acrylate copolymer, xylene resin, polyvinyl butyral resin, polyamide resin and modified polyphenylene oxide resins. These can be used singly or in combination of two or more.

  Examples of the elastic material rubber and elastomer include butyl rubber, fluorine-based rubber, acrylic rubber, EPDM, NBR, acrylonitrile-butadiene-styrene rubber natural rubber, isoprene rubber, styrene-butadiene rubber, butadiene rubber, ethylene-propylene rubber, ethylene- Propylene terpolymer, chloroprene rubber, chlorosulfonated polyethylene, chlorinated polyethylene, urethane rubber, syndiotactic 1,2-polybutadiene, epichlorohydrin rubber, ricone rubber, fluorine rubber, polysulfide rubber, polynorbornene rubber, hydrogenated Nitrile rubber, thermoplastic elastomer (for example, polystyrene, polyolefin, polyvinyl chloride, polyurethane, polyamide, polyurea, polyester, fluororesin), etc. It is. These can be used singly or in combination of two or more.

There is no restriction | limiting in particular as a electrically conductive agent for adjusting the volume resistance value of an intermediate transfer body, According to the objective, it can select suitably.
Examples of the conductive agent include carbon black, graphite, metal powder such as aluminum and nickel, tin oxide, titanium oxide, antimony oxide, indium oxide, potassium titanate, antimony oxide-tin oxide composite oxide (ATO), and indium oxide. -Conductive metal oxides such as tin oxide composite oxide (ITO). The conductive metal oxide may be coated with insulating fine particles such as barium sulfate, magnesium silicate, and calcium carbonate. Note that the conductive agent is not limited to these.
As the material (surface layer material) used for the surface layer of the belt, it is possible to prevent contamination of the photosensitive member by an elastic material, reduce the surface friction resistance of the transfer belt surface, and reduce the adhesion force of the toner. What improves the next transfer property is required.
For example, one or more types such as polyurethane, polyester, epoxy resin, etc. are used, and a material that reduces surface energy and improves lubricity (for example, fluororesin, fluorine compound, fluorocarbon, titanium dioxide, It can be used by dispersing one kind or two or more kinds of powders and particles of silicon carbide or the like, or a combination of those having different particle diameters. Further, it is also possible to use a material having a reduced surface energy by forming a fluorine-rich layer on the surface by heat treatment, such as a fluorine-based rubber material.

The manufacturing method of the belt is not limited. For example, a centrifugal molding method in which a material is poured into a rotating cylindrical mold to form a belt, a spray coating method in which a liquid paint is sprayed to form a film, and a cylindrical mold. There are several methods such as dipping method that immerses the material in the solution of material, casting method that pours it into the inner mold and outer mold, wrapping the compound around a cylindrical mold, and vulcanizing and polishing. In general, a belt is manufactured by combining the above.
Examples of methods for preventing the elastic belt from stretching include a method of forming a rubber layer in a core resin layer having a small amount of elongation, a method of putting a material for preventing elongation in the core layer, and the like, but are limited to a specific production method. is not.
Materials constituting the core layer for preventing elongation include, for example, natural fibers such as cotton and silk; polyester fibers, nylon fibers, acrylic fibers, polyolefin fibers, polyvinyl alcohol fibers, polyvinyl chloride fibers, polyvinylidene chloride fibers, Examples thereof include synthetic fibers such as polyurethane fibers, polyacetal fibers, polyfluoroethylene fibers, and phenol fibers; inorganic fibers such as carbon fibers, glass fibers, and boron fibers; metal fibers such as iron fibers and copper fibers.

These are used alone or in combination of two or more, and those in the form of woven fabric or yarn are also used.
The yarn may be twisted in any manner, such as one or a plurality of filaments twisted, a single twisted yarn, various twisted yarns, a double yarn or the like. Further, for example, fibers of a material selected from the above material group may be blended. Of course, the yarn can be used after being subjected to an appropriate conductive treatment. On the other hand, the woven fabric can be any woven fabric such as knitted fabric, and of course, a woven fabric that is interwoven can also be used, and naturally conductive treatment can be applied.
The manufacturing method for providing the core layer is not particularly limited. For example, a method of providing a coating layer on a woven fabric woven in a cylindrical shape, and a woven fabric woven in a cylindrical shape. Examples include a method of providing a coating layer on one or both sides of the core layer by immersing in liquid rubber or the like, a method of winding a thread spirally around a mold or the like at an arbitrary pitch, and providing a coating layer thereon. .
The thickness of the elastic layer depends on the hardness of the elastic layer, but if it is too thick, the surface expands and contracts and cracks are likely to occur in the surface layer. Further, it is not preferable that the thickness is too large (approximately 1 mm or more) because the amount of expansion / contraction is large and the expansion / contraction of the image is large.

The transfer means (the primary transfer means and the secondary transfer means) is a transfer device that peels and charges the visible image formed on the electrostatic latent image carrier (photoconductor) to the recording medium side. It is preferable to have at least. There may be one transfer means or two or more transfer means.
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. A PET base for OHP Etc. can also be used.

<Fixing process and fixing means>
The fixing step is a step of fixing the visible image transferred to the recording medium by a fixing device. For example, when the transferred visible image is in color, each color toner is transferred to the recording medium. Or may be performed simultaneously in a state in which the toners of the respective colors are stacked.
The fixing device is not particularly limited and may be appropriately selected according to the purpose, but a known heating and pressing unit is preferable.
Examples of the heating and pressing means include a combination of a heating roller and a pressure roller, and a combination of a heating roller, a pressure roller, and an endless belt. The heating in the heating and pressurizing means is usually preferably 80 ° C to 200 ° C.
In the present invention, a known optical fixing device may be used together with or instead of the fixing step and the fixing unit depending on the purpose.

The neutralization step that is appropriately selected and provided is a step of performing neutralization by applying a neutralization bias to the electrostatic latent image carrier, and this step can be suitably performed by a neutralization unit.
There is no particular limitation on the neutralizing means, and it is sufficient that a neutralizing bias can be applied to the electrostatic latent image carrier, and it can be appropriately selected from known neutralizers. As a suitable static elimination means, a static elimination lamp etc. are mentioned, for example.
A cleaning step that is appropriately selected and provided is a step of removing the electrophotographic toner remaining on the electrostatic latent image carrier, and this step can be suitably performed by a cleaning unit.
There is no particular limitation on the cleaning means, and it is sufficient that the electrophotographic toner remaining on the electrostatic latent image carrier can be removed, and can be appropriately selected from known cleaners.
Examples of suitable cleaning means include a magnetic brush cleaner, an electrostatic brush cleaner, a magnetic roller cleaner, a blade cleaner, a brush cleaner, and a web cleaner.

The image forming apparatus of the present invention preferably has a lubricity-imparting agent applying means for applying a lubricity-imparting agent to the surface of the electrostatic latent image carrier.
As the lubricity-imparting agent, metal soap is suitable, and the metal soap is preferably at least one selected from zinc stearate, aluminum stearate and calcium stearate.
In addition, the recycling step that is appropriately selected and provided is a step of recycling the toner (for example, color toner) removed by the cleaning step to the developing unit, and this step can be suitably performed by the recycling unit. There is no restriction | limiting in particular as a recycling means, A well-known conveyance means etc. are mentioned.
Furthermore, the control means that is appropriately selected and provided is a process for controlling each of the steps, and this step can be suitably performed by the control means. The control means is not particularly limited as long as the operation of each means can be controlled, and can be appropriately selected according to the purpose. Examples of the control means include devices such as a sequencer and a computer.

Here, the image forming apparatus of the present invention will be further described with reference to the drawings.
FIG. 6 is a schematic configuration diagram showing an example of the image forming apparatus of the present invention. The image forming apparatus shown in FIG. 6 is an image forming apparatus equipped with the electrostatic latent image carrier (photoreceptor) of the present invention, and includes a drum-shaped photoconductor 10, a charge eliminating lamp 2, a charge charger 3, an eraser 4, and image exposure. And a developing unit 6, a pre-transfer charger 7, a registration roller 8, a transfer charger 110, a separation charger 111, a separation claw 112, a pre-cleaning charger 113, a cleaning brush 114, a cleaning blade 115, and the like.
The shape of the photoconductor 10 is not limited to the drum shape as shown in FIG. 6, and may be, for example, a sheet shape or an endless belt shape. Various chargers include a corotron, a scorotron, a solid state charger, a contact arrangement, or a gap between the electrostatic latent image carrier and gap applying means such as a gap tape or a step at the end. Well-known means such as a charging roller disposed adjacent to each other can be used.

The charging roller arranged close to the charging roller is less charged unevenness than the charging roller arranged in contact, and has a large margin for charging failure caused by contamination of the charging roller, and can be used without maintenance. While there is a big merit, the applied voltage must be increased. As a result, the hazard on the surface of the photoconductor becomes extremely high, and in the case of a photoconductor having a conventional polymer binder as the outermost surface layer (charge transport layer or protective layer), wear is significant and the photoconductor life is shortened. There was a tendency for problems such as increased costs and increased maintenance frequency.
In addition, it is desirable to apply the AC voltage superimposed on the DC voltage, because the charging roller arranged in the vicinity causes the discharge to be unstable only by applying the DC voltage, leading to uneven image density.

The electrostatic latent image carrier (photoreceptor) of the present invention is stably charged with little wear even in a charging unit arranged in proximity. In addition, since required characteristics such as reduction of residual potential in the exposed area and suppression of image blur are achieved, a good image can be stably output even when used repeatedly for a long time. As the transfer means, the above charger can be generally used, but a combination of a transfer charger 110 and a separation charger 111 as shown in the figure is effective.
The charging roller arranged close to the charging roller is less charged unevenness than the charging roller arranged in contact, and has a large margin for charging failure caused by contamination of the charging roller, and can be used without maintenance. While there is a big merit, the applied voltage must be increased. As a result, the hazard on the surface of the photoconductor becomes extremely high, and in the case of a photoconductor having a conventional polymer binder as the outermost surface layer (charge transport layer or protective layer), wear is significant and the photoconductor life is shortened. There was a tendency for problems such as increased costs and increased maintenance frequency.
In addition, it is desirable to apply the AC voltage superimposed on the DC voltage, because the charging roller arranged in the vicinity causes the discharge to be unstable only by applying the DC voltage, leading to uneven image density.

The electrostatic latent image carrier (photoreceptor) of the present invention is stably charged with little wear even in a charging unit arranged in proximity. In addition, since required characteristics such as reduction of residual potential in the exposed area and suppression of image blur are achieved, a good image can be stably output even when used repeatedly for a long time. As the transfer means, the above charger can be generally used, but a combination of a transfer charger 110 and a separation charger 111 as shown in the figure is effective.
Light sources such as the image exposure unit 5 and the charge removal lamp 2 emit light 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). All things 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.

The light source or the like irradiates the photosensitive member with light by providing a transfer step, a static elimination step, a cleaning step, or a pre-exposure step in combination with light irradiation in addition to the steps including the respective means shown in the figure. Can do.
The toner developed on the photoconductor 10 by the developing unit 6 is transferred to the recording medium 9, but not all is transferred, and the toner remains on the photoconductor 10. If such a residual toner is not cleaned and the next copying process is performed, a charging failure or a problem in forming a latent image due to exposure occurs. Therefore, it is generally necessary to remove residual toner using a cleaning means. As the cleaning means, the cleaning brush 114 or the cleaning blade 115 may be used alone or in combination. Known cleaning brushes such as a fur brush and a mag fur brush are used.
As the cleaning blade 115, an elastic body having a low friction coefficient is used, and examples thereof include a urethane resin, a silicone resin, a fluororesin, a urethane elastomer, a silicone elastomer, a fluoroelastomer, and the like, and particularly, a thermosetting urethane resin. Urethane elastomers are preferred from the viewpoints of wear resistance, ozone resistance, and contamination resistance. The elastomer includes rubber.
The cleaning blade 115 preferably has a hardness (JIS-A) in the range of 65 to 85 degrees. Moreover, it is preferable that thickness is 0.8-3.0 mm and the amount of protrusions exists in the range of 3-15 mm. As other conditions, the contact pressure, the contact angle, the amount of biting, and the like can be determined as appropriate.

The cleaning means that comes in contact with the electrostatic latent image carrier (photoconductor) has high toner removal performance. However, as a matter of course, a mechanical hazard is given to the photoconductor to cause abrasion of the surface layer of the photoconductor.
However, since the photoconductor of the present invention has an extremely high wear resistance of the protective layer, it is possible to stably output a good image even in an image forming apparatus having a cleaning unit in contact with the surface.
Although not shown in the drawing, the image forming apparatus of the present invention may be provided with a mechanism for applying a lubricity-imparting agent to the surface of the photoreceptor. In particular, in recent years, spherical toners, which are advantageous for improving the image quality of electrophotography, have been put into practical use. However, spherical toners are difficult to blade-clean as compared with conventional pulverized toners. Are known. Therefore, measures such as increasing the contact pressure of the cleaning blade and using a urethane rubber blade having high hardness are being taken.
These methods tend to increase the hazard to the surface of the photoreceptor abutting against the blade. In fact, it has been found that the use of spherical toner tends to increase the amount of surface wear of the photoreceptor.

The electrostatic latent image bearing member (photoreceptor) of the present invention has very high wear resistance, and thus the protective layer hardly wears even under the above-mentioned conditions with a large hazard. There is a possibility that problems such as blade squealing and blade edge wear, which may be caused by a high friction coefficient, may occur.
For this problem, the friction coefficient of the surface of the electrostatic latent image carrier against the cleaning blade can be reduced over a long period of time by providing a lubricity imparting agent coating means on the surface of the photoreceptor and applying the lubricity imparting agent. Can solve the problem.
FIG. 7 shows a schematic diagram of a main part of a cleaning unit provided with means for applying a lubricity imparting agent.
In FIG. 7, a solid material having a lubricity imparting agent 116 in a rod shape is pressed against the cleaning brush 114, and when the cleaning brush 114 rotates, the lubricity imparting agent is scraped off and adhered to the brush. Is applied to the surface of the photoreceptor.
The lubricity-imparting agent need not be solid, and can be applied to the surface of the photoreceptor even in liquid, powder, or semi-kneaded form, and is not particularly limited as long as it satisfies electrophotographic characteristics. It can be selected appropriately.

Examples of the lubricity-imparting agent include metal soaps such as zinc stearate, barium stearate, aluminum stearate, calcium stearate; waxes such as carnauba, lanolin, and wax; lubricating oils such as silicone oil. . Among these, zinc stearate, aluminum stearate, and calcium stearate are particularly preferable because they are relatively easy to process into a rod shape and have a high lubricity imparting effect.
By providing the cleaning unit 117 with the lubricity-imparting agent applying means shown in FIG. 7, there are advantages such as easy layout design around the photosensitive drum and simplification of the apparatus. On the other hand, since a large amount of a lubricity imparting agent is mixed in the cleaned toner, there are cases where disadvantages such as difficulty in toner recycling and reduction in brush cleaning efficiency may occur. Also, although not shown in FIG. 6, by providing separate independently a coating unit having a lubricity imparting agent application means and the cleaning unit, it is also possible to eliminate the above disadvantage. In that case, the coating unit is preferably provided downstream of the cleaning unit. Furthermore, by providing coating units at a plurality of locations and operating them simultaneously or sequentially, it is possible to increase the lubricity imparting agent coating efficiency and control the consumption amount.

Figure 8 is Ru schematic configuration view showing another example of the image forming apparatus of the present invention.
In FIG. 8, a photoconductor 156 is the electrostatic latent image carrier of the present invention. That is, the photosensitive member 156 is driven to rotate counterclockwise in the drawing, and its surface is uniformly charged by a charging charger 153 using a corotron or a scorotron, and then the laser beam L emitted from a laser optical device (not shown). In response to scanning, an electrostatic latent image is carried. Since this scanning is performed based on single-color image information obtained by decomposing a full-color image into yellow, magenta, cyan, and black color information, the electrostatic drum for single color of yellow, magenta, cyan, or black is formed on the photosensitive drum 156. A latent image is formed.

The left side in the drawing of the drum-shaped photoreceptor 156, a revolver developing unit 250 is disposed. This has a yellow developing unit, a magenta developing unit, a cyan developing unit, and a black developing unit in a rotating drum-shaped casing, and each developing unit is sequentially moved to a developing position facing the photosensitive drum 156 by rotation. Move. The yellow developer, magenta developer, cyan developer, and black developer are for developing an electrostatic latent image by attaching yellow toner, magenta toner, cyan toner, and black toner, respectively. On the photosensitive drum 156, electrostatic latent images for yellow, magenta, cyan, and black are sequentially formed, and these are sequentially developed by the developing units of the revolver developing unit 250, so that a yellow toner image, a magenta toner image, and a cyan toner are developed. A toner image and a black toner image are obtained.

An intermediate transfer unit is disposed on the downstream side of the photoconductor 156 from the development position. This is because an intermediate transfer belt 158 stretched by a tension roller 159a, an intermediate transfer bias roller 157 as a transfer means, a secondary transfer backup roller 159b, and a belt drive roller 159c is driven by rotation of the belt drive roller 159c. Move endlessly clockwise. The yellow toner image, magenta toner image, cyan toner image, and black toner image developed on the photosensitive drum 156 enter an intermediate transfer nip where the photosensitive drum 156 and the intermediate transfer belt 158 are in contact with each other. Then, while being influenced by the bias from the intermediate transfer bias roller 157, the toner image is superimposed on the intermediate transfer belt 158 and intermediately transferred to form a four-color superimposed toner image.
The developing unit forms each single color toner image on the electrostatic latent image carrier, the transfer unit sequentially superimposes the color toner image on the intermediate transfer member, and performs the primary transfer. An intermediate transfer system that superimposes toner images using a so-called intermediate transfer belt that is configured to perform secondary transfer all at once on a recording medium has a relative positioning between the electrostatic latent image carrier and the intermediate transfer body. Since it is relatively easy and accurate, it is advantageous for color misregistration, and can be said to be an effective means for obtaining a high-quality full-color image.

Then, the surface of the photoreceptor 156 that has passed through the intermediate transfer nip with rotation is cleaned by the drum cleaning unit 155 with the transfer residual toner. The cleaning unit 155 cleans the transfer residual toner with a cleaning roller to which a cleaning bias is applied. However, the cleaning unit 155 may use a cleaning brush such as a fur brush or a mag fur brush, or a cleaning blade.
The surface of the photoconductor 156 from which the transfer residual toner has been cleaned is neutralized by a neutralization lamp 154. As the charge removal lamp 154, a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), an electroluminescence (EL), or the like is used. A semiconductor laser is used as the light source of the laser optical device. About these emitted lights, you may make it use only a desired wavelength range by various 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.

A transfer unit comprising various rollers such as a transfer belt, a transfer bias roller, and a drive roller is disposed on the lower side of the intermediate transfer unit in the drawing, and a conveyance belt 164 and a fixing unit 165 are arranged on the left side of the drawing. It is installed. In the transfer unit, the endlessly moving transfer belt may be moved in the vertical direction in the figure by a moving means (not shown). At least one color toner image (yellow toner image) on the intermediate transfer belt 158 When the two-color or three-color superimposed toner image passes through the position facing the paper transfer bias roller 163, the toner image moves to a position where it does not contact the intermediate transfer belt 158. Then, before the leading end of the four-color superimposed toner image on the intermediate transfer belt 158 enters the position facing the paper transfer bias roller 163, it moves to the contact position with the intermediate transfer belt 158 to move to the secondary transfer nip. Form.
On the other hand, the registration roller pair 161 that sandwiches the recording medium 160 sent from a paper feeding cassette (not shown) between two rollers can superimpose the recording medium 160 on the four-color superimposed toner image on the intermediate transfer belt 158. Feed toward the secondary transfer nip at the timing. The four-color superimposed toner image on the intermediate transfer belt 158 is secondarily transferred collectively onto the recording medium 160 under the influence of the secondary transfer bias from the paper transfer bias roller 163 in the secondary transfer nip. By this secondary transfer, a full color image is formed on the recording medium 160.

Then, the recording medium 160 on which the full color image is formed is sent to the paper conveying belt 164 by the transfer belt 162. The conveyance belt 164 sends the recording medium 160 received from the transfer unit into the fixing device 165. The fixing device 165 conveys the fed recording medium 160 while being sandwiched in a fixing nip formed by the contact between the heating roller and the backup roller. The full-color image on the recording medium 160 is fixed on the recording medium 160 under the influence of the heating from the heating roller and the pressure in the fixing nip.
Although not shown, a bias for attracting the recording medium P is applied to the transfer belt 162 and the conveyance belt 164. In addition, a paper neutralization charger that neutralizes the recording medium 160 and three belt neutralization chargers that neutralize each belt (intermediate transfer belt 158, transfer belt 162, and conveyance belt 164) are provided. The intermediate transfer unit also includes a belt cleaning unit having the same configuration as that of the drum cleaning unit 155, thereby cleaning the transfer residual toner on the intermediate transfer belt 158.

The image forming apparatus according to the present invention may have a tandem configuration including a plurality of image forming elements including the electrostatic latent image carrier, the electrostatic latent image forming unit, the developing unit, the transfer unit, and the fixing unit. FIG. 9 shows a schematic diagram of an example of an image forming apparatus having a tandem configuration.
In FIG. 9, the copying machine main body 150 is provided with an endless belt-like intermediate transfer member 50 at the center. The intermediate transfer member 50 is stretched around the support rollers 14, 15, and 16 and can be rotated clockwise in FIG. 9 . An intermediate transfer member cleaning device 17 for removing residual toner on the intermediate transfer member 50 is disposed in the vicinity of the support roller 15. The intermediate transfer member 50 stretched between the support roller 14 and the support roller 15 is a tandem type in which four image forming units 18 of yellow, cyan, magenta, and black are arranged to face each other along the conveyance direction. A developing device 120 is disposed. An exposure device 21 is disposed in the vicinity of the tandem developing device 120. A secondary transfer device 22 is disposed on the side of the intermediate transfer member 50 opposite to the side on which the tandem developing device 120 is disposed. In the secondary transfer device 22, a secondary transfer belt 24, which is an endless belt, is stretched around a pair of rollers 23, and the recording medium conveyed on the secondary transfer belt 24 and the intermediate transfer member 50 are in contact with each other. Is possible. A fixing device 25 is disposed in the vicinity of the secondary transfer device 22.
In the copying apparatus main body 150 of the tandem image forming apparatus, a sheet reversing device 28 for reversing the recording medium is formed in the vicinity of the secondary transfer device 22 and the fixing device 25 in order to form an image on both sides of the recording medium. Is arranged.

Next, formation of a full-color image (color copy) using the tandem developing device 120 will be described. That is, first, a document is set on the document table 130 of the automatic document feeder (ADF) 400, or the automatic document feeder 400 is opened and the document is set on the contact glass 32 of the scanner 300. 400 is closed.
When a start switch (not shown) is pressed, when the document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32, and then the document is set on the contact glass 32. Immediately after that, the scanner 300 is driven, and the first traveling body 33 and the second traveling body 34 travel. At this time, light from the light source is irradiated by the first traveling body 33 and reflected light from the document surface is reflected by the mirror in the second traveling body 34 and is received by the reading sensor 36 through the imaging lens 35 to be color. An original (color image) is read and used as black, yellow, magenta, and cyan image information.
Each image information of black, yellow, magenta and cyan is stored in each image forming means 18 (black image forming means, yellow image forming means, magenta image forming means and cyan image forming means in the tandem developing device 120. ) And black, yellow, magenta and cyan toner images are formed in the respective image forming means. That is, each image forming means 18 (black image forming means, yellow image forming means, magenta image forming means, and cyan image forming means) in the tandem developing device 120 is shown in a partially enlarged schematic view of FIG. As described above, the photoconductor 10 (the black photoconductor 10K, the yellow photoconductor 10Y, the magenta photoconductor 10M, and the cyan photoconductor 10C), the charger 60 for uniformly charging the photoconductor, An exposure unit that exposes the photoconductor for each color image based on color image information (L in FIG. 10), and forms an electrostatic latent image corresponding to each color image on the photoconductor; A developing device 61 for developing the electrostatic latent image with each color toner (black toner, yellow toner, magenta toner, and cyan toner) to form a toner image with each color toner; A transfer charger 62 for transferring the toner image onto the intermediate transfer member 50, a photoconductor cleaning device 63, and a static eliminator 64 are provided. Each monochrome image (black) is based on the image information of each color. Image, yellow image, magenta image, and cyan image) can be formed. The black image, the yellow image, the magenta image, and the cyan image formed in this way are formed on the black photoconductor 10K on the intermediate transfer member 50 that is rotated by the support rollers 14, 15, and 16, respectively. The black image, the yellow image formed on the yellow photoconductor 10Y, the magenta image formed on the magenta photoconductor 10M, and the cyan image formed on the cyan photoconductor 10C are sequentially transferred (primary transfer). Is done. Then, the black image, the yellow image, the magenta image, and the cyan image are superimposed on the intermediate transfer member 50 to form a composite color image (color transfer image).

The color toners for developing the color images are in a developing device in a state of being mixed with a carrier, and are agitated by the agitating screw 68 and charged by friction at that time. The charged carrier and toner are held in a raised state on the rotating magnet roller 72, and a magnetic brush 65 is formed. Part of the toner constituting the magnetic brush 65 moves to the surface of the electrostatic latent image bearing member 10 by an electric attractive force. As a result, a visible image of toner is formed on the surface of the electrostatic latent image carrier 10.
A cleaning unit 63 for cleaning the transfer residual toner is provided downstream of the transfer process. In FIG. 10, a brush cleaner 76 and a cleaning blade 75 are mounted, and the cleaning blade 75 is installed in a counter direction with respect to the advancing direction of the latent image carrier surface. The transfer residual toner is collected.
Further, the collected toner can be guided again into the developing device by a recycling means. In FIG. 10, recycling is achieved by guiding the toner collected by the cleaning unit to the developing device 61 through the conveying screw 79 and the recycling path 80.

On the other hand, in the paper feed table 200, one of the paper feed rollers 142 is selectively rotated to feed out a sheet (recording paper) from one of the paper feed cassettes 144 provided in multiple stages in the paper bank 143. Each sheet is separated and sent to the paper feed path 146, transported by the transport roller 147, guided to the paper feed path 148 in the copying machine main body 150, and abutted against the registration roller 49 and stopped. Alternatively, the sheet feed roller 142 is rotated to feed out sheets (recording paper) on the manual feed tray 51, separated one by one by the separation roller 52, put into the manual feed path 53, and abutted against the registration roller 49 and stopped. . The registration roller 49 is generally used while being grounded, but may be used in a state where a bias is applied to remove paper dust from the sheet.
Then, the registration roller 49 is rotated in synchronization with the synthesized color image (color transfer image) synthesized on the intermediate transfer member 50, and a sheet (recording paper) is interposed between the intermediate transfer member 50 and the secondary transfer device 22. The secondary color transfer device 22 transfers the composite color image (color transfer image) onto the sheet (recording paper), thereby transferring the color image onto the sheet (recording paper). Is formed. The residual toner on the intermediate transfer member 50 after image transfer is cleaned by the intermediate transfer member cleaning device 17.

The sheet (recording paper) on which the color image has been transferred is conveyed by the secondary transfer device 22 and sent to the fixing device 25, where the combined color image (color) is generated by heat and pressure. (Transfer image) is fixed on the sheet (recording paper). The fixing device 25 is configured by pressing a pressure roller 27 against the fixing belt 26.
The sheet (recording paper) is switched by the switching claw 55 and discharged by the discharge roller 56 and is stacked on the paper discharge tray 57. Alternatively, the sheet (recording paper) is switched by the switching claw 55 and reversed by the sheet reversing device 28 to return to the transfer position. After guiding and recording an image on the back side, the image is discharged by the discharge roller 56 and stacked on the discharge tray 57.
In the tandem method, latent image formation and development of each color can be performed in parallel, so that the image formation speed can be much higher than that of the revolver method. Furthermore, the printer of FIG. 9 also employs an intermediate transfer method, and by mounting the electrostatic latent image carrier of the present invention, a high-quality full-color image with little color misregistration can be repeated very quickly for a long period of time. It can output stably.

[Process cartridge]
The process cartridge of the present invention comprises at least one means selected from electrostatic latent image forming means, exposure means, developing means, transfer means, and cleaning means, and the electrostatic latent image carrier of the present invention. Furthermore, you may have the other means suitably selected as needed.
The developing means includes at least a developer container that contains the toner or developer of the present invention, and a developer carrier that carries and transports the toner or developer contained in the developer container. Further, a layer thickness regulating member for regulating the thickness of the toner layer to be carried may be provided.
Here, for example, as shown in FIG. 11, the process cartridge includes a photosensitive member 101, and includes a charger 102, an exposure unit 103, a developing unit 104, and a cleaning unit 107, and other units as necessary. It has. In the figure, reference numeral 105 denotes a recording medium, and 108 denotes a conveyance roller. As the photosensitive member 101, the electrostatic latent image carrier of the present invention is used. In addition, a light source capable of writing with high resolution is used for the exposure unit 103, and an arbitrary charging member is used for the charger 102.

The image forming apparatus of the present invention is constructed by integrally combining the electrostatic latent image carrier and the constituent elements such as a developing device and a cleaning device as a process cartridge, and this unit is detachable from the apparatus main body. It may be configured. Further, at least one of a charger, an image exposure device, a developing device, a transfer or separation device, and a cleaning device is integrally supported together with an electrostatic latent image carrier to form a process cartridge, and is detachably attached to the apparatus main body. One unit may be detachable using guide means such as a rail of the apparatus main body.
By using the process cartridge, the electrostatic latent image carrier and other process members can be exchanged in a short time and easily, so that the time required for maintenance can be shortened and the cost can be reduced. Further, since the process member and the electrostatic latent image carrier are integrated, there are also advantages such as improvement of relative position accuracy.

EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to the following Example.
Note that “parts” used in the examples all represent parts by mass .
Example 1
An undercoat layer was formed on an Al support (outer diameter 30 mmφ) by dipping so that the film thickness after drying was 3.5 μm.
・ Coating liquid alkyd resin for undercoat layer 6 parts (Beckosol 1307-60-EL, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 4 parts (Super Becamine G-821-60, manufactured by Dainippon Ink & Chemicals, Inc.)
Titanium oxide 40 parts (CR-EL: Ishihara Sangyo)
50 parts of methyl ethyl ketone On this undercoat layer, a charge generation layer coating solution containing a bisazo pigment having the following structure was dip coated and dried by heating to form a 0.2 μm thick charge generation layer.
-Coating solution for charge generation layer 2.5 parts of bisazo pigment with the following structure

Polyvinyl butyral (XYHL, manufactured by UCC)
0.5 parts cyclohexanone 200 parts methyl ethyl ketone 80 parts On this charge generation layer, a charge transport layer coating solution having the following structure was dip-coated and heat-dried to obtain a charge transport layer having a thickness of 22 µm.

・ Coating liquid for charge transport layer 10 parts of bisphenol Z type polycarbonate 10 parts of low molecular charge transport material with the following structure
Tetrahydrofuran 80 parts 1% silicone oil in tetrahydrofuran 0.2 parts (KF50-100CS, manufactured by Shin-Etsu Chemical Co., Ltd.)
Spray coating is performed on the charge transport layer using a crosslinked surface layer coating solution having the following constitution, and light irradiation is performed under the conditions of a metal halide lamp, irradiation intensity: 700 mW / cm ² , irradiation time: 20 seconds, and further 130 Drying at 30 ° C. for 30 minutes was performed to provide an 8.0 μm crosslinked surface layer, whereby the electrostatic latent image carrier of Example 1 was obtained.
・ Crosslinking surface layer coating solution 10 parts of radically polymerizable monomer having 3 or more functional radical polymerizable groups having no charge transporting structure (KAYARAD TMPTA, manufactured by Nippon Kayaku)
Molecular weight: 382, number of functional groups: trifunctional, molecular weight / number of functional groups = 99
10 parts of radically polymerizable compound having a charge transporting structure (Exemplary Compound No. 54)
Photoinitiator 1 part 1-Hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals)
Zinc antimonate sol (Selnax CX-Z210IP-F2: solid content 20% by mass produced by Nissan Chemical Industries) 10 parts Tetrahydrofuran 180 parts

(Example 2)
In Example 1, the radically polymerizable compound having the charge transporting structure in the crosslinked surface layer coating solution was exemplified as Compound No. 360 and 7 parts of zinc antimonate sol was used. Then, an electrostatic latent image carrier of Example 2 was produced.
(Example 3)
In Example 1, the radical polymerizable compound having a charge transporting structure in the crosslinked surface layer coating solution was exemplified as Compound No. 379, and the same procedure as in Example 1 except that 3 parts of the zinc antimonate sol was used. Then, an electrostatic latent image carrier of Example 3 was produced.
Example 4
In Example 1, the radical polymerizable compound having a charge transporting structure in the crosslinked surface layer coating solution was exemplified as compound No. 1, and the same procedure as in Example 1 except that 30 parts of zinc antimonate sol was used. Then, an electrostatic latent image carrier of Example 4 was produced.
(Example 5)
In Example 1, the radical polymerizable compound having a charge transporting structure in the crosslinked surface layer coating solution was exemplified as Compound No. 53, and the same procedure as in Example 1 except that the zinc antimonate sol was 12 parts. Then, an electrostatic latent image carrier of Example 5 was produced.
(Example 6)
The electrostatic latent image of Example 6 was obtained in the same manner as in Example 1 except that the radical polymerizable compound having a charge transporting structure in the crosslinked surface layer coating solution in Example 1 was changed to Exemplified Compound No. 142. A carrier was prepared.

(Example 7)
In Example 1, except that the radical polymerizable monomer having a trivalent or higher radical polymerizable group having no charge transporting structure in the crosslinked surface layer coating solution was changed to the following substance, An electrostatic latent image carrier of Example 7 was produced.
Radical polymerizable monomer having no charge transporting structure is a trifunctional or higher radical polymerizable monomer caprolactone modified dipentaerythritol hexaacrylate (KAYARAD DPCA-60, manufactured by Nippon Kayaku Co., Ltd.)
Molecular weight: 1263, number of functional groups: 6 functions, molecular weight / number of functional groups = 211
(Example 8)
In Example 1, except that the radical polymerizable monomer having a trivalent or higher radical polymerizable group having no charge transporting structure in the crosslinked surface layer coating solution was changed to the following substance, An electrostatic latent image carrier of Example 7 was produced.
Radical polymerizable monomer having no charge transporting structure is a trifunctional or higher radical polymerizable monomer caprolactone modified dipentaerythritol hexaacrylate (KAYARAD DPCA-120, Nippon Kayaku molecular weight: 1947, functional group number: 6 functional, molecular weight / Number of functional groups = 325
(KAYARAD TMPTA, Nippon Kayaku)
Example 9
In Example 1, a radical polymerizable group 12 parts of trifunctional or more radical polymerizable monomers over having no charge transport structure of the crosslinked surface layer coating liquid, a radically polymerizable compound having a charge transport structure An electrostatic latent image carrier of Example 9 was produced in the same manner as Example 1 except that 4 parts and 20 parts of zinc antimonate sol were used.

(Example 10)
In Example 1, 11 parts radical polymerizable group is a trifunctional or more radical polymerizable monomers over having no charge transport structure of the crosslinked surface layer coating liquid, a radically polymerizable compound having a charge transport structure An electrostatic latent image carrier of Example 10 was produced in the same manner as Example 1 except that 6 parts and 16 parts of zinc antimonate sol were used.
(Example 11)
In Example 1, 6 parts of a radical polymerizable group trifunctional or more radical polymerizable monomers over having no charge transport structure of the crosslinked surface layer coating liquid, a radically polymerizable compound having a charge transport structure An electrostatic latent image carrier of Example 11 was produced in the same manner as Example 1 except that 11 parts and zinc antimonate sol were 3.5 parts.
(Example 12)
In Example 1, 4.5 parts radically polymerizable group trifunctional or more radical polymerizable monomers over having no charge transport structure of the crosslinked surface layer coating liquid, a radical polymerizable having a charge transport structure An electrostatic latent image carrier of Example 12 was produced in the same manner as in Example 1 except that 14 parts of the compound and 1.9 parts of zinc antimonate sol were used.
(Example 13)
In Example 1, in place of 10 parts of the zinc antimonate sol, a methanol sol of indium antimonate (solid content: 18% by mass, volume average) based on the method disclosed in Example 2 of JP-A-7-144717 to produce a particle size 0 .026μm), except for adding instead of zinc antimonate sol in the same manner as in example 1 to manufacture an electrostatic latent image bearing member 13

(Comparative Example 1)
In Example 1, an electrostatic latent image carrier of Comparative Example 1 was produced in the same manner as in Example 1 except that 10 parts of the zinc antimonate sol was not added.
(Comparative Example 2)
In Example 1, the electrostatic latent image carrier of Comparative Example 2 was prepared in the same manner as in Example 1 except that 5 parts of alumina fine particles (AA03: manufactured by Sumitomo Chemical Co., Ltd.) were used instead of 10 parts of zinc antimonate sol. Produced.
(Comparative Example 3)
In Example 1, an electrostatic latent image carrier of Comparative Example 3 was prepared in the same manner as in Example 1 except that 5 parts of silica fine particles (KMPX100: manufactured by Shin-Etsu Chemical Co., Ltd.) were used instead of 10 parts of the zinc antimonate sol. Produced.
(Comparative Example 4)
In Example 1, instead of 10 parts of the zinc antimonate sol, a comparison was made in the same manner as in Example 1 except that 7 parts of tin oxide colloid (Sun colloid HIT301M1, manufactured by Nissan Chemical Industries, Ltd., solid content: 30% by mass) was used. The electrostatic latent image carrier of Example 4 was produced.
(Comparative Example 5)
In Example 1, a radical polymerizable group is 3 or more-functional radical polymerizable monomer over having no charge transport structure of the crosslinked surface layer coating liquid was 20 parts, the radical polymerizable compound having a charge transport structure An electrostatic latent image carrier of Comparative Example 5 was produced in the same manner as Example 1 except that was not added.
(Comparative Example 6)
In Example 1, instead of the radical polymerizable compound having a charge transporting structure, a low molecular charge transporting material used in the coating liquid for the charge transporting layer was used. No. 6 electrostatic latent image carrier was produced.

<Post-exposure potential measurement, post-exposure potential variation measurement>
The post-exposure potential measurement was carried out using a full-color printer (IPSiO CX8200) equipped with a developing unit in which the produced electrostatic latent image carrier was modified so that a probe of a surface potentiometer (Model 344 manufactured by Trek) was installed on the developing sleeve. : Ricoh Co., Ltd.), and after adjusting the voltage of the charger so that the non-exposure portion potential (VD) is -700 V, writing equivalent to a 1200 dpi full-surface image is performed. The surface potential at the developing sleeve portion was measured, and the maximum value, the minimum value, and the potential difference between the maximum value and the minimum value in the exposure portion surface potential measurement for an arbitrary rotation of the drum were evaluated.

<Image evaluation>
As an image evaluation, a 600dpi 1by1 halftone image was output, and image density unevenness was evaluated. In addition, test patterns were output and image blur was evaluated.
<Evaluation of wear resistance>
Each electrostatic latent image carrier obtained above is converted into a full-color printer (IPSiO CX8200: manufactured by Ricoh Co., Ltd.) [(1) the cleaning blade contact pressure is quadrupled and the load on the photoreceptor is worn. Was added. ].
Using the above-mentioned modified printer, after adjusting the voltage of the charger so that the non-exposure portion potential (VD) becomes −700 V, the laser exposure with a wavelength of 660 nm results in 600 dpi equivalent, A4 size, and image area ratio of 6%. A running test (test paper; MyPaper made by NBS Ricoh) that outputs a test image is performed 100,000 sheets, and the thickness of the photosensitive layer before and after the running test is measured using an eddy current film thickness meter (Fischer Scope MMS, manufactured by Fischer). The amount of wear was measured from the difference between the two.

These evaluation results are shown in Table 4.

From the above results, the electrostatic latent image carriers of Examples 1 to 13 having the configuration of the present invention are excellent in wear resistance, and the variation in the exposure portion potential is suppressed. As a result, the density of the halftone image is reduced. It can be seen that there is almost no unevenness. In Comparative Examples 1 to 4 that do not depend on the configuration of the present invention, it is considered that the variation in the potential of the exposed portion is as large as 35 V or more, thereby causing density unevenness in the halftone image. In Comparative Example 5, it is considered that image blur due to a decrease in electrostatic charge retention ability of the surface layer and density decrease due to thinning of dots occur. In Comparative Example 6, the wear of the surface layer by the running test is remarkable, and the wear resistance as a protective layer is not sufficient.

(Other examples)
In the image forming apparatus of the present invention, a mechanism is provided in which a Mals bar in which zinc stearate is melted and solidified is brought into contact with the cleaning brush so as to be pressed by a spring, and the zinc stearate is applied to the surface of the photoreceptor via the cleaning brush. When the electrostatic latent image carrier of Examples 1 to 23 was mounted on the process cartridge and a running test was performed, the amount of wear was greatly reduced in almost all the photoconductors. The results of a running test using a Mars bar using calcium stearate and aluminum stearate instead of zinc stearate and a wax bar obtained by melting and solidifying carnauba wax were also good.
That is, the electrostatic latent image carrier of the present invention is very excellent in wear resistance and electrophotographic characteristics. Therefore, the image forming apparatus using the electrostatic latent image carrier, the process cartridge, and the image forming method using them can form a stable image over a long period of time.

It is a schematic cross section showing an example of the layer structure of the electrostatic latent image carrier of the present invention. It is a schematic cross section which shows another example of the layer structure of the electrostatic latent image carrier of this invention. It is a schematic cross section which shows another example of the layer structure of the electrostatic latent image carrier of this invention. It is a schematic cross section which shows another example of the layer structure of the electrostatic latent image carrier of this invention. It is a schematic cross section which shows another example of the layer structure of the electrostatic latent image carrier of this invention. 1 is a schematic diagram illustrating an example of an image forming apparatus of the present invention. It is a schematic block diagram which shows an example of the lubrication agent application mechanism used for the image forming apparatus of this invention. It is a schematic block diagram which shows another example of the image forming apparatus of this invention. FIG. 2 is a schematic explanatory diagram illustrating an example in which the image forming method of the present invention is carried out by the image forming apparatus (tandem color image forming apparatus) of the present invention. 1 is a partially enlarged schematic explanatory diagram of an image forming apparatus. It is the schematic which shows an example of the process cartridge of this invention.

Explanation of symbols

10 Photoconductor (Photoconductor drum)
For 10K black photoconductor 10Y for yellow photoconductor 10M for magenta photoconductor 10C for cyan photoconductor 14 support roller 15 support roller 16 supporting the roller 17 an intermediate transfer cleaning device 18 imaging hands stage
2 1 exposure device 22 a secondary transfer device 23 roller 24 a secondary transfer belt 25 fixing device 26 fixing belt 27 the pressure roller 28 the sheet reversing equipment
3 second contact glass 33 first traveling body 34 and the second traveling body 35 forming lens 36 reads sensor
4 9 registration roller 50 the intermediate transfer member 51 the bypass tray 52 separating roller 53 Bypass paper feed path 55 switching pawl 56 discharge rollers 57 discharge tray
60 Charger 61 Developer 62 Transfer Charger 63 Photoconductor Cleaning Device 64 Charger 70 Charger Lamp 80 Recycling Route
DESCRIPTION OF SYMBOLS 1 01 Photoconductor 102 Charging device 103 Exposure device 104 Developing means 107 Cleaning means 110 Transfer charger 120 Tandem type developing device
DESCRIPTION OF SYMBOLS 1 30 Document stand 142 Paper feed roller 143 Paper bank 144 Paper feed cassette 145 Separation roller 146 Paper feed path 147 Conveyance roller 148 Paper feed path 150 Copier main body 200 Paper feed table 201 Support body 202 Photosensitive layer 203 Charge generation layer 204 Charge transport Layer 205 Undercoat layer 206 Protective layer 207 Intermediate layer
3 00 scanner 400 automatic document feeder (ADF)

Claims (24)

In a latent electrostatic image bearing member having at least a photosensitive layer on a conductive support, the surface layer of the photosensitive layer has at least a radical polymerizable group having a trivalent or higher functional radical polymerizable group having no charge transport structure and charge transport. A cross-linked layer obtained by curing a radically polymerizable compound having a crystalline structure, and the cross-linked surface layer has the following formula: M _x Sb _y O _z (where M represents a metal element. _X , y, and z are An electrostatic latent image carrier characterized by containing at least one conductive fine particle containing zinc antimonate (ZnSb ₂ O ₆ ) . A protective layer on the photosensitive layer, the electrostatic latent image bearing member according to 請 Motomeko 1 wherein said protective layer and said outermost layer der Rukoto. The functional group of the radical polymerizable monomer having a radical polymerizable group having no charge transporting structure contained in the coating solution for the surface layer is an acryloyloxy group and / or a methacryloyloxy group. The electrostatic latent image carrier according to claim 1 or 2 . The ratio of the molecular weight to the number of functional groups (molecular weight / number of functional groups) in the radical polymerizable monomer having a trivalent or higher radical polymerizable group having no charge transporting structure used for the surface layer is 250 or less. The electrostatic latent image carrier according to claim 1. Electrostatic according to any one of claims 1 to 4, characterized in that at least one radical-polymerizable compound have a charge transport structure for use in the surface layer is one radically polymerizable functional groups Latent image carrier. Radically polymerizable functional groups of the radical polymerizable compound to have a charge transport structure for use in the surface layer, according to any one of claims 1 to 5, characterized in that an acryloyloxy group or a methacryloyloxy group An electrostatic latent image carrier. 7. The electrostatic latent image carrier according to claim 1, wherein the charge transport structure of the radical polymerizable compound having a charge transport structure used for the surface layer is a triarylamine structure. . At least one radical polymerizable compound having a charge transport structure for use in the surface layer, according to claim 1 to 7, characterized in that a compound represented by the following general formula (I) or (II) Noi The electrostatic latent image carrier according to any one of the above.
(In the formula, R ₁₀ represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a cyano group, a nitro group, an alkoxy group, —COOR ₁₁ ( R ₁₁ represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted aryl group, a carbonyl halide group, or CONR ₁₂ R ₁₃ (R ₁₂ and R ₁₃ are hydrogen atoms, A halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted aryl group, which may be the same or different from each other, and Ar ₁ and Ar ₂ are Represents a substituted or unsubstituted arylene group, which may be the same or different , Ar ₃ and Ar ₄ represent a substituted or unsubstituted aryl group; X ₁₀ represents a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene ether group, an oxygen atom, a sulfur atom, Represents a vinylene group, Z represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene ether group, or an alkyleneoxycarbonyl group, and m and n represent an integer of 0 to 3.) 9. The radically polymerizable compound having a charge transporting structure used for the surface layer is a compound represented by the following general formula (III) : An electrostatic latent image carrier.

(In the formula, o, p and q are each an integer of 0 or 1, Ra represents a hydrogen atom or a methyl group, Rb and Rc represent substituents other than a hydrogen atom and represent an alkyl group having 1 to 6 carbon atoms, and are the same. S and t each represents an integer of 0 to 3. Za is a single bond, a methylene group, an ethylene group,

Represents. ) Claims radically polymerizable group having no charge transport structure for use in the surface layer component ratio of trifunctional or more radical polymerizable monomers, characterized in that 30 to 70 wt% with respect to the cross-linked surface layer the total amount Item 10. The electrostatic latent image carrier according to any one of Items 1 to 9 . According to any one of claims 1 to 10 component ratio of the radical polymerizable compound have a charge transport structure for use in the surface layer, characterized in that 30 to 70 wt% with respect to the cross-linked surface layer the total amount An electrostatic latent image carrier. 12. The electrostatic latent image bearing member according to claim 1, wherein the photosensitive layer has a laminated structure of a charge generation layer, a charge transport layer, and a crosslinked surface layer from the support side . An electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, and developing the electrostatic latent image with toner to form a visible image An image forming apparatus having at least developing means for transferring, transfer means for transferring the visible image to a recording medium, and fixing means for fixing the transferred image transferred to the recording medium,
An image forming apparatus, wherein the latent electrostatic image bearing member is the latent electrostatic image bearing member according to claim 1. The image forming apparatus according to claim 13, further comprising a cleaning unit that contacts the surface of the electrostatic latent image carrier and removes toner remaining on the surface of the electrostatic latent image carrier . The electrostatic latent image forming means has a charger and an exposure device. The charger is arranged in contact or non-contact with the electrostatic latent image carrier, and static electricity is generated by applying DC and AC voltages in a superimposed manner. 15. The image forming apparatus according to claim 13, wherein the surface of the electrostatic latent image carrier is charged . The charger is a charging roller arranged in a non-contact proximity by means for giving a gap to the electrostatic latent image carrier, and a surface of the electrostatic latent image carrier is applied by applying a direct current and an alternating voltage to the charging roller. The image forming apparatus according to claim 15, wherein the image forming apparatus is charged . The image forming apparatus according to claim 13, further comprising a lubricant imparting agent coating unit that applies a lubricity imparting agent to the surface of the electrostatic latent image carrier . The image forming apparatus according to claim 17, wherein the lubricity imparting agent is a metal soap . The image forming apparatus according to claim 18, wherein the metal soap is at least one selected from zinc stearate, aluminum stearate, and calcium stearate . 20. The image forming apparatus according to claim 13, wherein a color image is formed by sequentially superposing a plurality of color toners . 21. A tandem type image forming apparatus comprising a plurality of image forming elements each having at least an electrostatic latent image carrier, an electrostatic latent image forming unit, a developing unit, a transfer unit, and a fixing unit. The image forming apparatus according to any one of the above . An intermediate transfer body on which a toner image formed on the electrostatic latent image carrier is primarily transferred; and a transfer means for secondary transfer of the toner image carried on the intermediate transfer body to a recording medium, The color image is formed by sequentially superimposing toner images of a plurality of colors on an intermediate transfer member, and the color image is secondarily transferred collectively onto a recording medium. the image forming apparatus. An electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier, a developing step of developing the electrostatic latent image with toner to form a visible image, and the visible image An image forming method including at least a transfer step of transferring the image to a recording medium and a fixing step of fixing the transferred image transferred to the recording medium,
13. The image forming method according to claim 1, wherein the latent electrostatic image bearing member is the latent electrostatic image bearing member according to any one of claims 1 to 12. It comprises at least one of an electrostatic latent image forming unit, an exposure unit, a developing unit, a transfer unit, and a cleaning unit, and the electrostatic latent image carrier according to any one of claims 1 to 12. Process cartridge.