JP2012247605A - Electrophotographic photoreceptor, process cartridge for image forming apparatus, image forming apparatus, and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor that has desired mechanical durability, includes a surface layer having excellent electrical characteristics, prevents the occurrence of failure relating to output image quality of an image forming apparatus such as wear and scratches due to repeated use of the electrophotographic photoreceptor, and has excellent electrical characteristics, as well as a process cartridge for an image forming apparatus using the electrophotographic photoreceptor, an image forming apparatus, and an image forming method.SOLUTION: An electrophotographic photoreceptor includes at least a photosensitive layer and a surface layer on a conductive support in this order. The surface layer contains a polymerization composition produced by irradiating a mixture containing a specific carbazole compound, and a carbazole compound having a radical polymerizable functional group represented by the following general formula (2) with light.

Description

The present invention relates to an electrophotographic photosensitive member used in an electrophotographic image forming apparatus such as a copying machine, a laser printer, and an ordinary facsimile, and a process cartridge for the image forming apparatus using the electrophotographic photosensitive member, an image forming apparatus, and an image forming apparatus. Regarding the method.
Specifically, even when the electrophotographic photosensitive member is used for a long time, the electrophotographic photosensitive member capable of suppressing the wear of the photosensitive member and maintaining excellent photosensitive member characteristics and image formation using the same The present invention relates to a method, an image forming apparatus, and a process cartridge for the image forming apparatus.

〔Market trend〕
In recent years, from the viewpoints of saving office space, expanding business opportunities, etc., high speed, downsizing, colorization, high image quality, and easy maintenance are desired for electrophotographic apparatuses. These are regarded as problems to be solved by developing an electrophotographic photosensitive member because they are related to improvement in characteristics and durability of the electrophotographic photosensitive member. From the viewpoint of improving ease of maintenance, there is a reduction in the replacement frequency of the electrophotographic photosensitive member. This is to reduce the main image defects derived from the electrophotographic photosensitive member as much as possible over a long period of time, which is nothing but the extension of the life of the electrophotographic photosensitive member. In addition, in recent years, there have been many reports on development relating to extending the life of electrophotographic photosensitive members because they are related to the improvement of the image quality of output images over a long period of time.

  In order to achieve the long life of the electrophotographic photosensitive member, it is important to improve the durability against the mechanical hazard and the electrical hazard that the electrophotographic photosensitive member receives from the image forming process. Of these, the former often employs a process that receives a relatively large mechanical hazard, as will be described later, for the purpose of maintaining high-quality output over a long period of time. For this reason, many studies have been reported on improvement of durability against mechanical hazards (hereinafter referred to as mechanical durability) as electrophotographic photosensitive members.

[Cause of wear and estimation mechanism]
An electrophotographic image forming apparatus is generally an electrophotographic photosensitive member, a charger for charging the electrophotographic photosensitive member, and a latent image for forming an electrostatic latent image on the surface of the electrophotographic photosensitive member charged by the charger. The image forming apparatus includes an image forming device, a developing device that attaches toner to the image portion of the electrostatic latent image formed by the latent image forming device, and a transfer unit that transfers the toner attached to the image portion to the transfer object. Some of them are equipped with a cleaning device that removes toner remaining on the surface of the photoreceptor without being transferred, if necessary. Since toner remaining on the surface of the photoconductor after the transfer contributes to image quality deterioration, a cleaning device is employed in many image forming apparatuses.

  As the cleaning device, a brush, a magnetic brush, a blade, or the like is generally used. For brush cleaning, polyester and acrylic fibers are used, and are used after optimization by changing the shape such as loop shape and straight hair shape, and the hardness and thickness of the fibers. However, in brush cleaning, it is difficult to sufficiently remove toner, for example, fine powder toner slips between fibers. The same applies to magnetic brushes, and in this method, attempts have been made to remove electrostatically by applying an electric field, but this is sufficient to cause a phenomenon such as toner scattered by electrostatic force reattaching to the photoreceptor. Cleaning is difficult. Therefore, as the current cleaning means, blade cleaning using an elastic blade is mainly used from the standpoint of removal of residual toner, cost, and reduction in diameter. In blade cleaning, the photosensitive member surface layer slides in contact with the cleaning blade, toner, and the like, and therefore mechanical wear and scratches are likely to occur on the photosensitive member surface.

  Due to the characteristics of the apparatus constituent members as described above, a physical external force is directly applied to the surface of the photoreceptor, and thus durability against them has been required.

  Many research examples have been reported for these problems by improving the hardness of the photoreceptor surface. For example, in Patent Document 1: Japanese Patent Laid-Open No. 2001-125286 and Patent Document 2: Japanese Patent Laid-Open No. 2001-324857, when a magnetic brush type is applied as a charger, magnetic particles are involuntarily formed on the photoreceptor. It has been proposed to increase the hardness of the surface layer of the photoconductor in order to prevent the transfer from occurring and the particles from being strongly pressed against the photoconductor in the transfer unit or the cleaning unit. Japanese Patent Application Laid-Open No. 2003-98708 proposes increasing the hardness of the photoconductor in order to suppress photoconductor surface wear when the blade-type cleaning method is applied.

  As specific means for increasing the surface hardness of the photoreceptor as described above, it has been proposed to use a crosslinkable material such as a thermosetting resin or a UV curable resin as a constituent component of the photoreceptor surface layer. . For example, methods for improving wear resistance and scratch resistance of a surface layer by applying a thermosetting resin as a binder component of the surface layer are disclosed in Patent Documents 4 to 6 (Japanese Patent Laid-Open Nos. 5-181299 and 2002). -6526 and JP-A-2002-82465). Further, in Patent Documents 7 to 9 (JP 2000-284514 A, JP 2000-284515 A, JP 2001-194413 A) and the like, by using a siloxane resin having a cross-linked structure as a charge transport substance, It has been proposed to improve wear and scratch resistance. Further, in Patent Documents 10 to 11 (Patent Nos. 3194392 and 3286704), a monomer having a carbon-carbon double bond in both the binder and the charge transport material in order to improve wear resistance and scratch resistance. A method using a charge transport material having a carbon-carbon double bond and a binder resin has been reported.

  These crosslinkable materials form a tough film by cross-linking molecules with each other. The characteristics of the crosslinkable material depend on the crosslinking conditions (temperature conditions, humidity conditions, etc. for thermosetting resins, light wavelengths, illuminance, light quantity, temperature conditions, humidity conditions, etc. for photocurable resins). Different characteristics can be developed even with the same material.

  In particular, photocrosslinkable resins are very fast to be cured, and by changing the light irradiation conditions depending on the location, it is possible to obtain films with different characteristics even within the same plane. , Easy to express unique characteristics. However, in order to express desired characteristics with high reproducibility, it is necessary to set light irradiation conditions, temperature conditions, and the like in detail. In addition, since ultraviolet rays having high energy are often used to polymerize the photocrosslinkable resin, attention should be paid to material deterioration due to irradiation light.

  For example, when the light irradiated body (layered body, component of the layered body) is photodegraded, the selection of the emission wavelength of the light source used for curing, the selection of the corresponding initiator, the illuminance, the exposure amount, etc. It is necessary to minimize the influence on the irradiated object by selecting the irradiation conditions. It is possible to form a crosslinked structure with little photodegradation by selecting these crosslinking conditions (see Patent Document 12: JP 2008-233118 A, Patent Document 13 JP 2008-275941 A). In the case of an organic semiconductor represented by an electrophotographic photosensitive member, even if it is applied to a device in which the characteristic value changes greatly even if a very small amount of impurities is mixed, even if the material is slightly deteriorated. Device characteristics (hereinafter referred to as electrical characteristics) are likely to fluctuate greatly as well as impurities. In particular, triarylamine compounds generally used for electrophotographic photoreceptors as hole transport materials absorb ultraviolet wavelengths and are relatively susceptible to light irradiation. For this reason, problems such as the occurrence of problems such as insufficient mechanical durability, which is a characteristic of the crosslinked structure, and difficulty in coexistence of mechanical durability and electrical characteristics, are easily manifested by the selection of the crosslinking conditions.

  In addition to the selection of the crosslinking conditions, a technique such as adding a light absorber to the irradiated body has also been proposed (see Japanese Patent Application Laid-Open No. 2007-206170). Problems similar to the selection of the crosslinking conditions such as deterioration of characteristics are likely to occur, and it is difficult to say that the technical means is sufficiently effective against light deterioration.

  In this way, a number of technologies have been reported as means for improving mechanical durability, but there are still few reported examples of technologies that can achieve both sufficient mechanical durability and electrical characteristics (and their stability). Each company is working on technological development to resolve these issues.

  The present invention has been made in view of the above problems in the prior art, has a desired mechanical durability, has a surface layer having excellent electrical characteristics, and is based on repeated use of the electrophotographic photoreceptor. An electrophotographic photosensitive member that does not cause defects related to the output image quality of the image forming apparatus, such as wear and scratches, and has excellent electrical characteristics, a process cartridge for an image forming apparatus using the electrophotographic photosensitive member, and an image forming apparatus It is another object of the present invention to provide an image forming method.

As a result of intensive studies, the present inventors have conducted photoirradiation by suppressing photodegradation of constituent components when using a photocrosslinkable material in order to improve the abrasion resistance and scratch resistance of the photoreceptor surface layer. The surface layer which can have a high freedom degree as conditions was discovered.
In order to solve the above problems, the electrophotographic photosensitive member according to the present invention, the process cartridge for the image forming apparatus using the electrophotographic photosensitive member, the image forming apparatus, and the image forming method are specifically described in the following ( It has the technical features described in I) to (X).

(I): a carbazole compound having at least a photosensitive layer and a surface layer in this order on a conductive support, the surface layer having no radically polymerizable functional group represented by the following general formula (1) An electrophotographic photoreceptor comprising a polymerization composition produced by irradiating a mixture containing a carbazole compound having a radical polymerizable functional group represented by the following general formula (2) with light.

[In General Formula (1), R _{1 to} R ₉ are each independently a saturated or unsaturated aliphatic group which may have a hydrogen atom, a nitro group, a cyano group, a halogen atom, a hydroxyl group or a substituent. A hydrocarbon group, an aromatic hydrocarbon group which may have a substituent, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, an amino group, a substituent; represents an diarylamino group also have good dialkylamino groups or substituents have, _{R 3} and _R 4, _{R 4} and _R 5, _{R 6} and _R 7, _{R 7} and _{R 8,} Each may be bonded to each other to form an aromatic ring. ]

[In General Formula (2), each of R _{11 to} R ₁₉ independently represents a saturated or unsaturated aliphatic hydrocarbon or aromatic hydrocarbon having at least one acryloyloxy group or methacryloyloxy group, a hydrogen atom, Group, cyano group, halogen atom, hydroxyl group, saturated or unsaturated aliphatic hydrocarbon group which may have a substituent, aromatic hydrocarbon group which may have a substituent, and substituent Represents an optionally substituted alkoxy group, an optionally substituted aryloxy group, an amino group, an optionally substituted dialkylamino group or an optionally substituted diarylamino group , R ₁₃ and R ₁₄ , R ₁₄ and R ₁₅ , R ₁₆ and R ₁₇ , R ₁₇ and R ₁₈ may be bonded to each other to form an aromatic ring. However, at least one of R _{11 to} R ₁₉ is a saturated or unsaturated aliphatic hydrocarbon or aromatic hydrocarbon having at least one acryloyloxy group or methacryloyloxy group. ]

(II): The carbazole compound having a radical polymerizable functional group represented by the general formula (2) is a carbazole compound represented by the following general formula (3). This is an electrophotographic photoreceptor.

[In General Formula (3), R _{101 to} R ₁₀₅ each independently represents a saturated or unsaturated aliphatic hydrocarbon or aromatic hydrocarbon having at least one acryloyloxy group or methacryloyloxy group, a hydrogen atom, nitro Group, cyano group, halogen atom, hydroxyl group, saturated or unsaturated aliphatic hydrocarbon group which may have a substituent, aromatic hydrocarbon group which may have a substituent, and substituent Represents an optionally substituted alkoxy group, an optionally substituted aryloxy group, an amino group, an optionally substituted dialkylamino group or an optionally substituted diarylamino group R _{12 to} R ₁₉ have a hydrogen atom, a nitro group, a cyano group, a halogen atom, a hydroxyl group, a saturated or unsaturated aliphatic hydrocarbon group which may have a substituent, or a substituent. An aromatic hydrocarbon group which may have a substituent, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, an amino group, a dialkylamino group which may have a substituent Or an optionally substituted diarylamino group, R ₁₃ and R ₁₄ , R ₁₄ and R ₁₅ , R ₁₆ and R ₁₇ , R ₁₇ and R ₁₈ are bonded to each other to form an aromatic ring; It may be formed. However, any one or more of R _{101 to} R ₁₀₅ is a saturated or unsaturated aliphatic hydrocarbon or aromatic hydrocarbon having at least one acryloyloxy group or methacryloyloxy group. ]

(III): The carbazole compound having a radical polymerizable functional group represented by the general formula (2) has one polymerizable functional group, and is described in (I) or (II) above An electrophotographic photoreceptor.

(IV): A mass ratio of the carbazole compound having no polymerizable functional group to the carbazole compound having the polymerizable functional group is 0.2 or more and 2.0 or less. The electrophotographic photosensitive member according to any one of (III).

(V): The electrophotographic photosensitive member according to any one of (I) to (IV) above, wherein the surface layer contains inorganic fine particles in a proportion of 5 vol% or more and 40 vol% or less.

(VI): The electrophotographic photosensitive member according to (V), wherein the inorganic fine particles include at least one selected from aluminum oxide, titanium oxide, silicon oxide, and tin oxide.

(VII): The electrophotographic photosensitive member according to any one of (I) to (VI) above, wherein the photosensitive layer includes a charge generation layer and a charge transport layer.

(VIII): formed by the charging step of charging the electrophotographic photosensitive member, the latent image forming step of forming an electrostatic latent image on the surface of the electrophotographic photosensitive member charged by the charging step, and the latent image forming step. A development process for forming a toner image by attaching toner to the image portion of the electrostatic latent image, a transfer process for transferring the toner image formed by the development process to a transfer target, and an electrophotographic photosensitive after the transfer process. A cleaning process for removing toner remaining on the surface of the body, and the electrophotographic photoreceptor is the electrophotographic photoreceptor according to any one of (I) to (VII) above. Image forming method.

(IX): The electrophotographic photosensitive member according to any one of (I) to (VII) above, a charging unit for charging the electrophotographic photosensitive member, and a surface on the surface of the electrophotographic photosensitive member charged by the charging unit. Latent image forming means for forming an electrostatic latent image, developing means for forming a toner image by attaching toner to an image portion of an electrostatic latent image formed by the latent image forming means, and after the toner image is transferred One or two or more means selected from cleaning means for removing toner remaining on the surface of the electrophotographic photosensitive member is mounted, and the image forming apparatus process cartridge is mounted integrally. An image forming apparatus characterized by being free.

(X): The electrophotographic photosensitive member according to any one of (I) to (VII) above, a charging unit for charging the electrophotographic photosensitive member, and a surface on the surface of the electrophotographic photosensitive member charged by the charging unit. Latent image forming means for forming an electrostatic latent image, developing means for forming a toner image by attaching toner to an image portion of an electrostatic latent image formed by the latent image forming means, and after the toner image is transferred One or more means selected from cleaning means for removing toner remaining on the surface of the electrophotographic photosensitive member, and a process cartridge for an image forming apparatus, wherein the process cartridge is detachable from the main body of the image forming apparatus. is there.

  According to the present invention, a surface layer having desired mechanical durability and excellent electrical characteristics is provided, and the output image quality of the image forming apparatus is related to wear and scratches due to repeated use of the electrophotographic photosensitive member. It is possible to provide an electrophotographic photosensitive member having no defects and having excellent electrical characteristics, and a process cartridge, an image forming apparatus, and an image forming method for an image forming apparatus using the electrophotographic photosensitive member.

It is the schematic which shows the laminated structure in one Embodiment in the electrophotographic photoreceptor which concerns on this invention. (Single layer photosensitive layer) It is the schematic which shows the laminated structure in other embodiment in the electrophotographic photoreceptor which concerns on this invention. (Laminated photosensitive layer) It is the schematic which shows the laminated structure in other embodiment in the electrophotographic photoreceptor which concerns on this invention. (Laminated photosensitive layer) It is the schematic which shows the laminated structure in other embodiment of the electrophotographic photoreceptor which concerns on this invention. (Laminated photosensitive layer) 1 is a schematic diagram illustrating an example of a configuration of a main part of an image forming apparatus according to the present invention. FIG. 2 is a schematic diagram illustrating an example of a configuration of a process cartridge for an image forming apparatus according to the present invention. It is a graph which shows the result of the X-ray diffraction of the titanyl phthalocyanine used in the Example.

<Requirements for long-life electrophotographic photoreceptor>
In order to achieve a long life of the electrophotographic photosensitive member, it is important to impart durability to various hazards received from each process in image formation as is conventionally known. In particular, two hazards, a mechanical hazard that is applied in a cleaning process for removing toner remaining on the surface of the electrophotographic photosensitive member, and an electrostatic hazard that is received from a charging process or a transfer process, give a large stress to the photosensitive member. It is considered to cause a change in the characteristics of the photoreceptor and to be an impeding factor for extending the life of the photoreceptor. Among these, in the present invention, it relates to improvement in durability against mechanical hazards and electrostatic hazards, and more specifically, a technique in which wear of an electrophotographic photosensitive member is reduced even when used for a long period of time and fluctuations in electrical characteristics are small. About.

<< Mechanical durability expression means >>
In order to suppress the occurrence of wear and scratches due to repeated use, it is effective that the mechanical strength represented by the hardness and elastic work rate of the surface of the photoconductor is large. Various methods and materials are used to increase these characteristics. Has been developed. In order to increase the mechanical strength, it is generally known to use a crosslinkable material in which molecules are bonded to each other. The crosslinkable material can express various properties by selecting the functional group structure, molecular structure, number of functional groups, etc., and not only the desired mechanical strength but also the electrical properties required for electrophotographic photoreceptors. Recently, it has been attracting attention as a material for electrophotographic photoreceptors because it allows molecular design that also takes into account the physical characteristics.

  Crosslinkable materials can be broadly divided into heat crosslinkable materials, photocrosslinkable materials, and ionizing radiation crosslinkable materials. Thermally crosslinkable materials are characterized in that intermolecular crosslinking gradually proceeds at room temperature or high temperature. Since the film is easily cross-linked by heat after film formation, the production equipment is simple and the influence on the human body and the environment is small, so it is widely used industrially. However, it takes a long time to cure and is easily affected by the manufacturing environment. Furthermore, since the curing time is relatively long and it is necessary to apply heat during that time, there may be a problem that a low molecular weight additive is transferred between the layers.

《Problems of using photocrosslinkable materials (photodegradation)》
The photocrosslinkable material and ionizing radiation crosslinkable material can easily crosslink the material by irradiating the material with predetermined light and ionizing radiation, and a highly crosslinked film can be obtained instantaneously. It is characterized by the fact that phenomena such as environmental dependence and low-molecular-weight material migration that occur when using thermally crosslinkable materials are less likely to occur. Photocrosslinkable materials are widely used in industrial applications because the apparatus configuration used for production is not complicated and the influence on the human body is relatively small. On the other hand, many ionizing radiation-crosslinking materials have complicated production facilities and are expensive, and since the influence of ionizing radiation itself on the human body cannot be denied, there are not many examples used industrially.

  For the above reasons, it is considered effective to use a photocrosslinkable material in order to develop excellent mechanical strength. However, as light used for crosslinking the photocrosslinkable material, short wavelength light having high energy is used. Often used for forming a laminated structure such as an electrophotographic photosensitive member, it is necessary to consider the influence of light on the entire laminated structure. In particular, since the surface layer is directly exposed to light irradiation, it is a layer that is most susceptible to light deterioration, and the use of a material with little light deterioration for the layer is an effective means for characteristic deterioration due to light irradiation.

As a result of intensive studies to achieve the above object, the present inventors have found that the surface layer has at least a radically polymerizable functional group represented by the general formula (1) and a carbazole compound represented by the general formula (2). The carbazole compound having a radically polymerizable functional group represented by the above formula and polymerizing the carbazole compound having a radically polymerizable functional group by irradiating with light, has extremely high mechanical durability. It has been found that a surface layer having high electrical characteristics can be obtained by the action.
That is, the electrophotographic photosensitive member according to the present invention has at least a photosensitive layer and a surface layer in this order on a conductive support, and the surface layer is a radical polymerizable compound represented by the following general formula (1). And a polymerization composition produced by irradiating a mixture containing a carbazole compound having no functional group and a carbazole compound having a radical polymerizable functional group represented by the following general formula (2). To do.

[In General Formula (1), R _{1 to} R ₉ are each independently a saturated or unsaturated aliphatic group which may have a hydrogen atom, a nitro group, a cyano group, a halogen atom, a hydroxyl group or a substituent. A hydrocarbon group, an aromatic hydrocarbon group which may have a substituent, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, an amino group, a substituent; represents an diarylamino group also have good dialkylamino groups or substituents have, _{R 3} and _R 4, _{R 4} and _R 5, _{R 6} and _R 7, _{R 7} and _{R 8,} Each may be bonded to each other to form an aromatic ring. ]

[In General Formula (2), each of R _{11 to} R ₁₉ independently represents a saturated or unsaturated aliphatic hydrocarbon or aromatic hydrocarbon having at least one acryloyloxy group or methacryloyloxy group, a hydrogen atom, Group, cyano group, halogen atom, hydroxyl group, saturated or unsaturated aliphatic hydrocarbon group which may have a substituent, aromatic hydrocarbon group which may have a substituent, and substituent Represents an optionally substituted alkoxy group, an optionally substituted aryloxy group, an amino group, an optionally substituted dialkylamino group or an optionally substituted diarylamino group , R ₁₃ and R ₁₄ , R ₁₄ and R ₁₅ , R ₁₆ and R ₁₇ , R ₁₇ and R ₁₈ may be bonded to each other to form an aromatic ring. However, at least one of R _{11 to} R ₁₉ is a saturated or unsaturated aliphatic hydrocarbon or aromatic hydrocarbon having at least one acryloyloxy group or methacryloyloxy group. ]

Details of the present invention will be described below.
<Explanation regarding the structure of the electrophotographic photoreceptor>
The electrophotographic photoreceptor of this embodiment (hereinafter also simply referred to as a photoreceptor) is a laminate having at least a photosensitive layer and a surface layer in this order on a conductive support. The photosensitive layer may have a single layer structure or a multilayer structure as long as it has a charge generation function and a charge transport function. An example of the embodiment will be described with reference to FIG. 1, FIG. 2, FIG. 3, and FIG.

The cross-sectional view of the electrophotographic photosensitive member shown in FIG. 1 is an example in the case where the photosensitive layer is a single layer. On the conductive support 21, a photosensitive layer 26 mainly composed of a charge generating material and a charge transporting material and A surface layer 25 is provided. The surface layer 25 described here is a surface layer described below.
The cross-sectional views of the electrophotographic photosensitive member shown in FIGS. 2 to 4 are examples in the case where the photosensitive layer is laminated, and the charge generation layer 23 responsible for the charge generation function on the conductive support 21 and the charge transport function. In this embodiment, the charge transport layer 24 is stacked separately. In the case of taking this embodiment, as shown in the drawing, the order of stacking the charge generation layer and the charge transport layer is not particularly limited, and can be properly used according to the application. The surface layer 25 is formed on the outermost surface of the photoreceptor. Laminated. Further, if necessary, an undercoat layer (intermediate layer) 22 can be laminated adjacent to the conductive support.

<Surface layer>
<< Explanation on surface layer constituents >>
The surface layer described in the present invention has at least a carbazole compound having no radical polymerizable functional group represented by the general formula (1) and a radical polymerizable functional group represented by the general formula (2). It consists of a carbazole compound that is cross-linked with a carbazole compound having a radical polymerizable functional group by light irradiation. Accordingly, it is possible to form a surface layer having excellent mechanical durability and extremely high electrical characteristics. In addition to the carbazole compound, various additives described later may be added for the purpose of imparting a desired function to the surface layer.

<Description of carbazole compound having no radical polymerizable functional group>
In the present invention, a carbazole compound having no radically polymerizable functional group represented by the general formula (1) is suitably used as the hole transport material that is not easily deteriorated by light irradiation. It has been found by the present inventors that even when the compound is applied to the light surface layer, its electrical characteristics do not depend on the amount of light irradiation and exhibits a high hole transport function. For this reason, in order to provide high mechanical durability as the surface layer, even when the amount of light irradiation is relatively high, the electrical characteristics are hardly deteriorated.

[In General Formula (1), R _{1 to} R ₉ are each independently a saturated or unsaturated aliphatic group which may have a hydrogen atom, a nitro group, a cyano group, a halogen atom, a hydroxyl group or a substituent. A hydrocarbon group, an aromatic hydrocarbon group which may have a substituent, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, an amino group, a substituent; Represents a dialkylamino group which may have or a diarylamino group which may have a substituent, and R ₃ and R ₄ , R ₄ and R ₅ , R ₆ and R ₇ , R ₇ and R ₈ are Each may be bonded to each other to form an aromatic ring. ]

  Specific examples of the carbazole compound having no radically polymerizable functional group represented by the general formula (1) are shown below, but are not limited to the compounds (I-1) to (I-25) having these structures. Absent.

<< Description of Carbazole Compound Having Radical Polymerizable Functional Group >>
It is known that the carbazole compound having no radical polymerizable functional group, which is a feature of the present invention, has relatively high crystallinity due to its molecular structure. Therefore, when a commonly known compound having a radical polymerizable functional group and a carbazole compound not having a radical polymerizable functional group are used in combination, and a coating film is formed by the method described later, the compatibility of both compounds is good. In the case where there is not, a transparent coating film cannot be formed even if the carbazole compound having no radical polymerizable functional group is crystallized at the time of forming the coating film and the compound having a radical polymerizable functional group is crosslinked and polymerized. . In addition, even when the compatibility of both compounds is relatively high, crosslinking and polymerizing a compound having a radical polymerizable functional group can easily cause phase separation between the crosslinked structure and the non-crosslinked structure. As a result, an opaque coating film in which a carbazole compound having no radical polymerizable functional group is crystallized tends to be obtained.

  In the present invention, by using a carbazole compound having a radical polymerizable functional group described later in combination with the carbazole compound having no radical polymerizable functional group described above, both compounds are highly compatible before and after crosslinking and polymerization. A transparent and homogeneous surface layer can be formed. In addition, the surface layer formed using only a carbazole compound having a radically polymerizable functional group can form a transparent and homogeneous coating, but the electrical properties are not sufficient, whereas the radically polymerizable It has been found that when a carbazole compound having a radical polymerizable functional group is used in combination with a carbazole compound having no functional group and a carbazole compound having a radical polymerizable functional group is crosslinked and polymerized, it exhibits an extremely high charge transport function. . Although the detailed cause of this phenomenon is unknown at present, when only a carbazole compound having a radical polymerizable functional group is used, the carbazole skeleton responsible for the hole transport function is bound to the polymerizable functional group. It is considered that the degree of freedom of movement is lowered and it is difficult to form a structure necessary for expressing good hopping conduction. On the other hand, when a carbazole compound having a radical polymerizable functional group is used in combination with a carbazole compound having no radical polymerizable functional group, the freedom of movement is reduced between the carbazole skeletons of the polymerizable carbazole compound having a reduced degree of freedom of movement. It is assumed that the carbazole skeleton of the non-polymerizable carbazole compound having a high degree is easily arranged, and that the carbazole skeletons of both compounds complement each other in function.

  The carbazole compound having a radical polymerizable functional group used in the present invention is a product represented by the general formula (2), more preferably a carbazole having a radical polymerizable functional group represented by the general formula (3). By using the compound, a surface layer having excellent electrical characteristics in addition to high mechanical durability can be obtained.

[In General Formula (2), each of R _{11 to} R ₁₉ independently represents a saturated or unsaturated aliphatic hydrocarbon or aromatic hydrocarbon having at least one acryloyloxy group or methacryloyloxy group, a hydrogen atom, Group, cyano group, halogen atom, hydroxyl group, saturated or unsaturated aliphatic hydrocarbon group which may have a substituent, aromatic hydrocarbon group which may have a substituent, and substituent Represents an optionally substituted alkoxy group, an optionally substituted aryloxy group, an amino group, an optionally substituted dialkylamino group or an optionally substituted diarylamino group , R ₁₃ and R ₁₄ , R ₁₄ and R ₁₅ , R ₁₆ and R ₁₇ , R ₁₇ and R ₁₈ may be bonded to each other to form an aromatic ring. However, at least one of R _{11 to} R ₁₉ is a saturated or unsaturated aliphatic hydrocarbon or aromatic hydrocarbon having at least one acryloyloxy group or methacryloyloxy group. ]

[In General Formula (3), R _{101 to} R ₁₀₅ each independently represents a saturated or unsaturated aliphatic hydrocarbon or aromatic hydrocarbon having at least one acryloyloxy group or methacryloyloxy group, a hydrogen atom, nitro Group, cyano group, halogen atom, hydroxyl group, saturated or unsaturated aliphatic hydrocarbon group which may have a substituent, aromatic hydrocarbon group which may have a substituent, and substituent Represents an optionally substituted alkoxy group, an optionally substituted aryloxy group, an amino group, an optionally substituted dialkylamino group or an optionally substituted diarylamino group R _{12 to} R ₁₉ have a hydrogen atom, a nitro group, a cyano group, a halogen atom, a hydroxyl group, a saturated or unsaturated aliphatic hydrocarbon group which may have a substituent, or a substituent. An aromatic hydrocarbon group which may have a substituent, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, an amino group, a dialkylamino group which may have a substituent Or an optionally substituted diarylamino group, R ₁₃ and R ₁₄ , R ₁₄ and R ₁₅ , R ₁₆ and R ₁₇ , R ₁₇ and R ₁₈ are bonded to each other to form an aromatic ring; It may be formed. However, any one or more of R _{101 to} R ₁₀₅ is a saturated or unsaturated aliphatic hydrocarbon or aromatic hydrocarbon having at least one acryloyloxy group or methacryloyloxy group. ]

As the carbazole compound having a radical polymerizable functional group represented by the general formulas (2) to (3), a polyfunctional compound having two or more functions can be used. Those that are functional are preferred. This is because when a carbazole compound having a radically polymerizable functional group having two or more functional groups is used, it is fixed in the crosslinked structure by a plurality of bonds, but the charge transporting structure is very bulky, so it is distorted in the cured resin. Occurs, the internal stress of the surface layer becomes high, and it becomes easy to cause cracks and scratches due to carrier adhesion and the like. When the film thickness is 3 μm or less, there is no particular problem. However, when a film exceeding 3 μm is formed, the internal stress of the surface layer becomes very high, and cracks are likely to occur immediately after crosslinking and polymerization.
In addition, in terms of electrostatic characteristics, when a bifunctional or higher functional charge transporting compound is used, it is fixed in the crosslinked structure with a plurality of bonds, so that the intermediate structure (cation radical) during charge transport is stably maintained. In other words, the sensitivity is lowered due to charge trapping, and the residual potential is likely to increase. Such deterioration of the electrical characteristics appears as an image such as a decrease in image density and thinning of characters. For this reason, a monofunctional compound is used as the carbazole compound having a radical polymerizable functional group, and it is fixed in a pendant shape between the crosslinks, thereby generating cracks and scratches and stabilizing electrostatic characteristics. It becomes easy to become.

  Specific examples of the carbazole compound having no radically polymerizable functional group represented by the general formula (2) and the general formula (3) are shown below. The compounds (II-1) to (II-16) having these structures are shown below. And (III-1) to (III-16).

<< Explanation of component ratio >>
As described above, the carbazole compound having no radically polymerizable functional group represented by the general formula (1) has a high charge transporting function alone, but in the surface layer of the present invention, the radically polymerizable functional group is used. It is possible to impart an extremely high hole transport function by the interaction with the carbazole compound having the. In order to provide the surface layer with a high hole transport function and excellent mechanical durability, the mass ratio of the carbazole compound having no radical polymerizable functional group to the carbazole compound having a radical polymerizable functional group (radical polymerization). Carbazole compound having no functional functional group / carbazole compound having a radical polymerizable functional group) is preferably from 0.2 to 2.0. When the mass ratio is less than 0.2, it is not preferable because a surface layer exhibiting sufficient electrical characteristics cannot be obtained from the beginning due to a shortage of components responsible for the charge transport function as described above. Further, when the mass ratio exceeds 2.0, it is not preferable because sufficient mechanical durability cannot be obtained due to a shortage of components that form a crosslinked structure. Although the electrical characteristics and abrasion resistance required differ depending on the process used, it cannot be said unconditionally, but considering the balance of both characteristics, the mass ratio is most preferably in the range of 0.3 to 1.8.

<< Description of other radically polymerizable compounds >>
In the present invention, for the purpose of improving mechanical durability, a radical polymerizable compound having no carbazole skeleton may be used in combination. In the present invention, the number of functional groups of the radical polymerizable compound is not particularly limited, but in order to give the surface layer wear resistance, at least one radical polymerizable compound having three or more radical polymerizable functional groups is used. It is preferable to use it. When only the monofunctional and bifunctional radically polymerizable compounds are used, the cross-linking bond in the surface layer is so thin that it is difficult to achieve a dramatic improvement in wear resistance. However, when only a trifunctional or higher functional radical polymerizable compound is used, a decrease in surface smoothness due to an increase in viscosity for forming a surface layer (hereinafter referred to as a surface layer coating solution) or during a curing reaction. Defects such as cracks due to volume shrinkage may occur. For this reason, 1 to bifunctional radically polymerizable compounds and radically polymerizable oligomers are 1 for the purpose of adjusting the viscosity of the surface layer coating liquid, maintaining the surface smoothness of the surface layer, preventing cracks due to crosslinking shrinkage, and reducing the surface free energy. You may use together more than a kind.

  These radical polymerizable compounds include, for example, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, tetrahydrofurfuryl acrylate, 2-ethylhexyl carbitol acrylate, 3-methoxybutyl acrylate, benzyl acrylate, cyclohexyl Acrylate, isoamyl acrylate, isobutyl acrylate, methoxytriethylene glycol acrylate, phenoxytetraethylene glycol acrylate, cetyl acrylate, isostearyl acrylate, stearyl acrylate, styrene monomer, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate 1,4-butanediol dimethacrylate, 1,6-he Sundiol diacrylate, 1,6-hexanediol dimethacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, EO modified bisphenol A diacrylate, EO modified bisphenol F diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate ( TMPTA), trimethylolpropane trimethacrylate, trimethylolpropane alkylene modified triacrylate, trimethylolpropane ethyleneoxy modified (hereinafter EO modified) triacrylate, trimethylolpropane propyleneoxy modified (hereinafter PO modified) triacrylate, trimethylolpropane caprolactone modified Triacrylate, trimethylolpropane alkylene-modified trimeta Relate, pentaerythritol triacrylate, pentaerythritol tetraacrylate (PETTA), glycerol triacrylate, glycerol epichlorohydrin modified (ECH modified) triacrylate, glycerol EO modified triacrylate, glycerol PO modified triacrylate, tris (acryloxyethyl) Isocyanurate, dipentaerythritol hexaacrylate (DPHA), dipentaerythritol caprolactone-modified hexaacrylate, dipentaerythritol hydroxypentaacrylate, alkylated dipentaerythritol pentaacrylate, alkylated dipentaerythritol tetraacrylate, alkylated dipentaerythritol triacrylate , Dimethylolpropane tetra Examples include acrylate (DTMPTA), pentaerythritol ethoxytetraacrylate, phosphoric acid EO-modified triacrylate, 2,2,5,5, -tetrahydroxymethylcyclopentanone tetraacrylate, and the like in the present invention. It is not limited.

<< Explanation of photo radical polymerization initiator >>
As the polymerization initiator for initiating polymerization of the radical polymerizable compound, it is preferable to use a photo radical polymerization initiator.
The radical photopolymerization initiator is not particularly limited, and one or more commonly used compounds can be used. In addition, in order to perform radical polymerization efficiently, you may use a thermal-polymerization initiator together.

  As the radical photopolymerization initiator, those generally marketed can be used. The content of the photo radical polymerization initiator is preferably 0.5 part by mass to 40 parts by mass, and more preferably 1 part by mass to 20 parts by mass with respect to 100 parts by mass of the radical polymerizable compound.

<Description of inorganic fine particles>
In order to improve the mechanical durability of the surface layer, the surface layer can contain inorganic fine particles. The inorganic fine particles may be those generally known, such as titanium oxide, tin oxide, zinc oxide, zirconium oxide, indium oxide, antimony oxide, boron nitride, silicon nitride, calcium oxide, barium sulfate, ITO, silicon oxide, colloidal silica. Examples thereof include aluminum oxide. In consideration of the electrical characteristics of the surface layer, aluminum oxide, titanium oxide, silicon oxide, and tin oxide are preferably used.

  The average primary particle size of these filler fine particles is preferably 0.01 to 0.5 μm from the viewpoint of light transmittance and wear resistance of the surface layer. When the average primary particle size of the filler is less than 0.01 μm, it causes a decrease in dispersibility and the effect of improving the wear resistance is not sufficiently exhibited. When it exceeds 0.5 μm, the surface roughness of the surface layer is increased. Since the wear of the blade cleaning member, which will be described later, progresses rapidly, the toner cleaning failure occurs early, and the sedimentation of the filler in the dispersion is promoted depending on the specific gravity of the filler particles. May cause problems related to the life of the coating liquid for the surface layer.

  The higher the content of the inorganic fine particles in the surface layer, the better because the wear resistance is higher. However, if the content is too high, the charge transport function and wear resistance are lowered, which is not preferable. Good mechanical durability can be expected when the proportion of the inorganic fine particles in the surface layer is about 10 vol% to 40 vol%.

  As a method for quantifying the proportion of inorganic fine particles in the surface layer, elemental analysis and its mapping can be used. Here, as the elemental analysis / mapping method, for example, an energy dispersive X-ray detector / scanning electron microscope (EDS-SEM) can be used. The EDS-SEM scans the object to be observed with a finely focused electron beam and detects the amount of secondary electrons emitted to observe the object surface image in detail (generally 50 to 300,000 times). At the same time, by detecting characteristic X-rays generated by electron beam irradiation, it is an apparatus that analyzes the element ratio of a minute region on the surface, maps a specific element, and the like.

  The content of inorganic fine particles can be quantified by elemental analysis / mapping of the cross section of the electrophotographic photosensitive member by the above-described method. First, the cross-sectional structure of the electrophotographic photosensitive member is exposed by a commonly used method such as a microtome or FIB, and then the constituent elements of the inorganic fine particles on the cross section of the electrophotographic photosensitive member are mapped by the above-described method to detect the constituent elements of the inorganic fine particles. By dividing the area by the observation area, the area ratio of the organic-inorganic composite fine particles in the observation cross section is obtained. Subsequently, the ratio which occupies for the surface layer of this organic-inorganic composite fine particle can be obtained by converting the area ratio into a volume ratio (3/2 of the area ratio).

  As a method for dispersing the inorganic fine particles in the surface layer, it is preferable to disperse the inorganic fine particles by a dispersion method generally used in a surface layer coating liquid described later. Examples of the dispersion method include a ball mill, a sand mill, a KD mill, a three-roll mill, a pressure homogenizer, and ultrasonic dispersion.

  When the inorganic fine particles are dispersed in the surface layer, it can be surface-treated with a dispersant or a surfactant, which is preferable from the viewpoint of dispersibility. When the dispersibility of the organic / inorganic composite fine particles is insufficient, not only the effect of reducing the frictional resistance between the surface of the electrophotographic photosensitive member and the cleaning blade, which is the greatest effect in the present invention, but also the electrophotographic photosensitive member is reduced. In order to cause a decrease in charge transport property, charge retention, etc. that should be inherent, and decrease in transparency of the coating film and generation of coating film defects, it is preferable to take good measures to give good dispersibility. . In addition, the absence of agglomerated particles from the surface layer creates large surface irregularities, which also cause poor toner cleaning and reduced wear resistance of the electrophotographic photosensitive member, which is a major factor that hinders high durability or high image quality. There is a possibility. As the dispersant and the surfactant, commonly used dispersants and surfactants can be used.

  The amount of the surface treatment agent (dispersant, surfactant) used for the surface treatment varies depending on the average primary particle size of the inorganic fine particles used, but 0.5 to 30% by weight with respect to the weight of the inorganic fine particles is suitable. 1 to 20% by weight is more preferable. When the amount of the dispersant and the surfactant is less than this, the effect of dispersing the filler cannot be obtained, and when the amount is too large, the residual potential is remarkably increased. These surface treatment agents may be used alone or in combination of two or more.

<< Description of other additives >>
Furthermore, in the present invention, the surface layer coating solution may 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. Can be contained. 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. 20 parts by weight or less, preferably 10 parts by weight or less. As the leveling agent, 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 thereof is the surface layer coating liquid. 3 parts by weight or less is appropriate for the total solid content.

<< Description of film formation method >>
The surface layer of the present invention is obtained by applying a surface layer coating solution containing at least the above-mentioned carbazole compound having a radical polymerizable functional group and a carbazole compound not having a radical polymerizable functional group onto a photosensitive layer described later. It is formed by curing. If the surface layer component is a liquid at room temperature, the surface layer coating solution used for coating can be dissolved and coated with other components, but if necessary, dilute with a solvent. Applied. The solvent used here is not particularly limited as long as it is usually used. For example, 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, ethers such as tetrahydrofuran, dioxane and propyl ether, dichloromethane And halogen series such as dichloroethane, trichloroethane and chlorobenzene, aromatic series such as benzene, toluene and xylene, and cellosolv series such as methyl cellosolve, ethyl cellosolve and cellosolve acetate. These solvents may be used alone or in combination of two or more.

  The coating method used for forming the surface layer is not particularly limited as long as it is a commonly used coating method. A coating method may be appropriately selected depending on the viscosity of the coating liquid, the desired surface layer thickness, and the like. Examples include dip coating, spray coating, bead coating, ring coating, and the like.

<< Explanation of crosslinking and polymerization treatment >>
In the present invention, the surface layer is cured by applying energy from the outside after applying the surface layer coating solution. As the external energy used at this time, optical energy is mainly used, but thermal energy may be used in combination.

As the light energy, a light source such as an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a xenon arc metal halide lamp or the like may be used. It is preferable to select in consideration of the absorption characteristics of a monofunctional radically polymerizable compound having a charge transporting structure and a photopolymerization initiator used in combination. The emission intensity of light source used, generally it is being exposed at an intensity of 50mW ^/ cm ² ~2000mW ^/ cm 2 wavelengths of 365nm as a reference. Moreover, when the illuminance measurement in the vicinity of the maximum emission wavelength is possible, it is more preferable to expose in the illuminance range. When the illuminance is low, the time required for curing increases, which is not preferable from the viewpoint of productivity. On the other hand, when the illuminance is high, curing shrinkage is likely to occur, and the surface may have a skin-like defect or crack, or may peel at the interface with the adjacent layer.

  During UV irradiation, the temperature of the photoreceptor surface layer rises due to the influence of heat rays generated from the light source. If the surface temperature of the photoconductor rises too much, curing shrinkage of the surface layer is likely to occur, and low molecular components contained in the adjacent layer migrate to the surface layer, resulting in inhibition of curing or as an electrophotographic photoconductor. This is not preferable, for example, because the electrical characteristics are degraded. Therefore, the photoreceptor surface temperature during UV irradiation is 100 ° C. or less, preferably 80 ° C. or less. As a cooling method, it is possible to use a cooling agent sealed inside the photoconductor, cooling with a gas or liquid inside the photoconductor, or the like.

<< Explanation of heat drying process >>
In order to remove the solvent remaining in the surface layer after the completion of the crosslinking / polymerization treatment, a heat drying treatment is preferably performed. As the heat energy used in this treatment, air, nitrogen and other gases, steam, various heat media, infrared rays, and electromagnetic waves can be used. By heating from the coating surface side or the support side of the surface layer coating liquid, Done. The heating temperature is preferably 100 ° C. or higher and 170 ° C. or lower. When the temperature is lower than 100 ° C., the amount of the solvent remaining in the surface layer increases, which is not preferable because the electric characteristics of the surface layer are easily deteriorated. On the other hand, when the treatment is performed at a temperature higher than 170 ° C., the transition of the low molecular weight component of the adjacent layer to the surface layer is likely to occur, which may cause a decrease in mechanical durability and a decrease in electrical characteristics of the surface layer. It is not preferable.

<< Explanation of surface layer thickness >>
The film thickness of the surface layer is preferably 1 to 15 μm or less, preferably 3 to 10 μm from the viewpoint of protecting the photosensitive layer. When the surface layer is thin, not only the photosensitive layer cannot be protected from mechanical abrasion due to the contact member to the photosensitive member or proximity discharge by a charger, etc., but also the film surface becomes difficult to level during film formation. It may be crumpled. On the other hand, when the surface layer is thick, the entire photoreceptor layer becomes thick, and the reproducibility of the image due to the diffusion of charges is not preferable.

<Description of photosensitive layer>
Next, the photosensitive layer will be described.
<< In the case of laminated structure: laminated photosensitive layer >>
In the laminated photosensitive layer, the charge generation function and the charge transport function are independent layers. Therefore, the layer structure of the photosensitive layer is a structure in which at least a charge generation layer and a charge transport layer are stacked on a support. . The order of stacking is not particularly limited, but many charge generation materials have poor chemical stability, and the charge generation efficiency decreases when exposed to acidic gases such as discharge products around the charger in the electrophotographic imaging process. Cause. For this reason, a charge transport layer is preferably laminated on the charge generation layer.

<Charge generation layer>
The charge generation layer is a layer mainly composed of a charge generation material having a charge generation function, and a binder resin can be used in combination as necessary. As the charge generation material, inorganic materials and organic materials can be used.

Inorganic materials include crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, selenium-arsenic compounds, and amorphous silicon. In amorphous silicon, dangling bonds that are terminated with hydrogen atoms or halogen atoms, or those that are doped with boron atoms, phosphorus atoms, or the like are preferably used.
On the other hand, a known material can be used as the organic material. For example, phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine, azulenium salt pigments, squaric acid methine pigments, azo pigments having a carbazole skeleton, azo pigments having a triarylamine skeleton, azo pigments having a diphenylamine skeleton, dibenzothiophene skeleton Azo pigments having a fluorenone skeleton, azo pigments having an oxadiazole skeleton, azo pigments having a bis-stilbene skeleton, azo pigments having a distyryl oxadiazole skeleton, azo pigments having a distyrylcarbazole skeleton, perylene Pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane and triphenylmethane pigments, benzoquinone and naphthoquinone pigments, cyanine and azomethine pigments, Goido based pigments, and bisbenzimidazole pigments. These charge generation materials can be used alone or as a mixture of two or more.

  As a binder resin used as necessary for the charge generation layer, polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly-N-vinylcarbazole, Examples include polyacrylamide, polyvinyl benzal, polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyvinyl pyridine, cellulose resin, casein, polyvinyl alcohol, and polyvinyl pyrrolidone. These binder resins can be used alone or as a mixture of two or more. The amount of the binder resin is suitably 0 to 500 parts by weight, preferably 10 to 300 parts by weight with respect to 100 parts by weight of the charge generating material. The binder resin may be added before or after dispersion.

  Methods for forming the charge generation layer include a vacuum thin film preparation method and a casting method from a solution dispersion system. As the former method, a vacuum deposition method, a glow discharge decomposition method, an ion plating method, a sputtering method, a reactive sputtering method, a CVD method, or the like is used, and the above-described inorganic materials and organic materials can be satisfactorily formed. In addition, in order to provide the charge generation layer by the latter casting method, the inorganic or organic charge generation material described above, together with a binder resin, if necessary, tetrahydrofuran, dioxane, dioxolane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, cyclohexane. It can be formed by dispersing with a ball mill, attritor, sand mill, bead mill, etc. using a solvent such as pentanone, anisole, xylene, methyl ethyl ketone, acetone, ethyl acetate, butyl acetate, etc. Moreover, leveling agents, such as a dimethyl silicone oil and a methylphenyl silicone oil, can be added as needed. The coating can be performed using a dip coating method, spray coating, bead coating, ring coating method or the like.

  The thickness of the charge generation layer provided as described above is suitably about 0.01 to 5 μm, preferably 0.05 to 2 μm.

<Charge transport layer>
The charge transport layer is a layer having a charge transport function, and is a layer mainly composed of a charge transport material or a polymer charge transport material and a binder resin.

(Description of binder resin)
The binder resin is not particularly limited and may be appropriately selected from known materials according to the purpose. For example, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer. Polymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene , Thermoplastic or thermosetting resins such as poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, and alkyd resin.

(Description of general charge transport materials)
The charge transport material is not particularly limited and may be appropriately selected depending on the purpose. For example, a known hole transport material having a hole transport structure such as triarylamine, hydrazone, pyrazoline, carbazole, Known electron transport materials having an electron transport structure such as an electron-withdrawing aromatic ring having condensed polycyclic quinone, diphenoquinone, cyano group, and nitro group can be mentioned. The hole transport material or electron transport material may be used alone or as a mixture of two or more.

  The content of the charge transport material in the charge transport layer is preferably 20% by mass to 80% by mass and more preferably 30% by mass to 70% by mass with respect to the total mass of the charge transport layer. When the content of the charge transport material in the charge transport layer is less than 20% by mass with respect to the total mass of the charge transport layer, the charge transport property of the charge transport layer is reduced, so that desired light attenuation characteristics cannot be obtained. If it is greater than 80% by mass, it may be worn more than necessary due to various hazards received by the photoreceptor from the electrophotographic process. On the other hand, when the content of the charge transport material in the charge transport layer is within the particularly preferable range, a desired light attenuating property can be obtained, and an electrophotographic photoreceptor with a small amount of wear can be obtained by use. This is advantageous.

(Description of polymer charge transport materials)
The polymer charge transport material is a material having both the function of a binder resin described later and the function of a charge transport material.
The polymer charge transport material is not particularly limited and may be a known material, but is preferably at least one polymer selected from polycarbonate, polyurethane, polyester and polyether. In particular, a polycarbonate containing a triarylamine structure exemplified in Japanese Patent No. 3852812 and Japanese Patent No. 3990499 in at least one of the main chain and the side chain is preferable from the viewpoint of wear durability and charge transportability.

  The polymer charge transport materials may be used alone or in combination of two or more. Moreover, you may use together with binder resin used with the electric charge transport substance mentioned above from viewpoints, such as abrasion durability and film forming property. From the viewpoint of compatibility of charge transportability, when the polymer charge transport material and the binder are used in combination, the content of the polymer charge transport material is preferably 40% by mass to 90% by mass with respect to the total mass of the charge transport layer, 50 mass%-80 mass% is more preferable.

(Description of charge transport layer forming method)
The charge transport layer can be formed by dissolving or dispersing the charge transport material and the binder resin or the polymer charge transport material in a suitable solvent, applying the solution, and drying.

  Since most of the constituent components of the charge transport layer are solid at normal temperature and pressure, a solvent having a high affinity with each constituent component is used in preparing the charge transport layer coating solution. The solvent used here is not particularly limited as long as it is a known solvent generally used for painting and coating. The solvent to be used may be used independently, and 2 or more types may be mixed and used for it.

  The coating method used for forming the charge transport layer is not particularly limited, and a commonly used coating method can be used. The coating method can be appropriately selected depending on the viscosity of the coating liquid, the desired thickness of the charge transport layer, and the like. A coating method may be selected. Examples include dip coating, spray coating, bead coating, ring coating, and the like.

  In addition, a plasticizer and a leveling agent, which will be described later, can be added to the charge transport layer as necessary.

  The thickness of the charge transport layer is preferably 50 μm or less and more preferably 45 μm or less from the viewpoint of resolution and responsiveness. Regarding the lower limit, although it differs depending on the system to be used (particularly the charging potential), it is preferably 5 μm or more.

  The charge transport layer formed by the above means needs to be heated by some means from the viewpoint of electrophotographic characteristics and film viscosity, and the solvent as described above needs to be removed from the film. As the heat energy, air, nitrogen or other gas, steam, various heat media, infrared rays, or electromagnetic waves can be used, and heating is performed from the coating surface side or the support side of the charge transport layer coating solution.

  The heating temperature is preferably 100 ° C. or higher and 170 ° C. or lower. When the temperature is lower than 100 ° C., it is confirmed that the organic solvent in the film cannot be sufficiently removed, and the electrophotographic characteristics are deteriorated and the wear durability is reduced. On the other hand, when the treatment is performed at a temperature higher than 170 ° C., a surface-like defect or crack may occur on the surface, or peeling may occur at the interface with the adjacent layer. Further, when the volatile component in the photosensitive layer is sprayed to the outside, it is not preferable because desired electrical characteristics may not be obtained.

<< When the photosensitive layer is a single layer: Single-layer type photosensitive layer >>
The photosensitive layer having a single layer structure is a layer having a charge generation function and a charge transport function at the same time. The photosensitive layer can be formed by dissolving or dispersing a charge generating substance, a charge transporting substance, and a binder resin in a suitable solvent, and applying and drying them. Moreover, a plasticizer, a leveling agent, antioxidant, etc. can also be added as needed.

  As the binder resin, in addition to the binder resin previously mentioned in the charge transport layer, the binder resin mentioned in the charge generation layer may be mixed and used. Polymer charge transport materials can also be used favorably. The amount of the charge generation material with respect to 100 parts by mass of the binder resin is preferably 5 parts by mass to 40 parts by mass, and the amount of the charge transport material is preferably 190 parts by mass or less, and more preferably 50 parts by mass to 150 parts by mass.

  The single-layer type photosensitive layer is a dip coating method, spray coating, a coating solution in which a charge generating material, a binder resin and a charge transport material are dispersed together with a dispersing machine using a solvent such as tetrahydrofuran, dioxane, dichloroethane, and cyclohexane. It can be formed by coating with bead coat or ring coat.

  The thickness of the single-layer type photosensitive layer is preferably 5 μm to 25 μm.

《About additive materials》
In the electrophotographic photoreceptor of the present invention, for the purpose of improving environmental resistance, in particular, for the purpose of preventing a decrease in sensitivity and an increase in residual potential, an antioxidant generally commercially available for each of the photosensitive layer and the surface layer is used. Agents, plasticizers, lubricants, ultraviolet absorbers and leveling agents may be added. The addition amount of these additives may be appropriately selected according to the purpose, and is preferably 0.01% by mass to 10% by mass with respect to the total mass of the layer to be added.

《About conductive support》
The conductive support (hereinafter may be simply referred to as a support) is not particularly limited as long as it exhibits conductivity having a volume resistance of 10 ¹⁰ Ω · cm or less, and is appropriately selected according to the purpose. For example, metal such as aluminum, nickel, chromium, nichrome, copper, gold, silver and platinum; metal oxide such as tin oxide and indium oxide is deposited or sputtered to form film or cylindrical plastic, paper Or a plate made of aluminum, aluminum alloy, nickel, stainless steel, etc., and pipes that have been surface-treated by cutting, superfinishing, polishing, etc. be able to. Further, an endless nickel belt and an endless stainless steel belt disclosed in JP-A-52-36016 can also be used as a support.
In addition, those in which conductive powder is dispersed in an appropriate binder resin and coated to form a conductive layer on the support can also be used as the support in the present invention.

  Examples of the conductive powder include carbon black, acetylene black, metal powder such as aluminum, nickel, iron, nichrome, copper, zinc and silver, or metal oxide powder such as conductive tin oxide and ITO. Etc. The binder resin used at the same time includes polystyrene resin, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester resin, polyvinyl chloride resin, vinyl chloride-vinyl acetate. Copolymer, polyvinyl acetate resin, polyvinylidene chloride resin, polyarylate resin, phenoxy resin, polycarbonate resin, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral resin, polyvinyl formal resin, polyvinyl toluene resin, poly-N-vinyl carbazole, Thermoplastic, thermosetting resin, or photocurable resin such as acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, alkyd resin, and the like can be given.

  The conductive layer can be provided by dispersing and applying these conductive powder and binder resin in a suitable solvent such as tetrahydrofuran, dichloromethane, methyl ethyl ketone, toluene and the like.

  Furthermore, it is electrically conductive by a heat shrinkable tube in which the conductive powder is contained in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, Teflon (registered trademark) on a suitable cylindrical substrate. Those provided with a conductive layer can also be used favorably as the support of the present invention.

  As will be described later, a highly coherent laser may be used to form a latent image in the electrophotographic process. As described above, the support is often made of a metal material, many of which have a high surface reflectance. When an electrophotographic photosensitive member is manufactured by applying an inorganic semiconductor material on a support having such characteristics, interference occurs between writing light and reflected light from the support, and image defects are likely to occur. For this reason, when the reflectance of a support body is high, it is preferable to give an unevenness | corrugation to the surface of a support body and to reduce a reflectance. Further, protrusions and the like that are potentially present on the support may cause image defects when the photosensitive layer is laminated. By roughening this to an appropriate surface roughness, it is possible to provide a support surface with few protruding protrusions. As the surface irregularities, arithmetic ten-point average surface roughness (Rz) measured by the method described in JIS B0601-1982 was used as a representative characteristic value.

  As a method for measuring the surface roughness (Rz), for example, Surfcom 1400D (manufactured by Tokyo Seimitsu Co., Ltd.) was used, and the surface roughness (Rz) was measured with respect to an evaluation length of 2.5 mm and a reference length of 0.5 mm. Measurement points were 80 mm from both ends of the drum in the axial direction, 3 points in the center of the drum, and 4 types of 90 degrees in the circumferential direction. A total of 12 points were measured, and the average value was defined as the surface roughness (Rz) of the drum. The surface roughness (Rz) is preferably 0.6 μm or more. If Rz is smaller than this, moire due to writing light is likely to occur, which is not preferable. Further, even if Rz is large, there is no significant problem in use. However, if Rz is too large, it is difficult to form the undercoat layer uniformly, so care must be taken. From this viewpoint, the surface roughness (Rz) of the support is preferably 3.0 μm or less.

  Examples of the roughening method include honing and centerless polishing. The honing process is preferably used because it is inexpensive and the surface roughness can be easily adjusted. There are dry and wet processing methods for the honing process, and any of them may be used. Wet (liquid) honing is a method in which a powdery abrasive (abrasive grain) is suspended in a liquid such as water and sprayed onto the surface of the support at high speed to roughen the surface. The pressure, speed, amount, type, shape, size, hardness, specific gravity or suspension concentration of the abrasive can be controlled. Similarly, the dry honing process is a method in which an abrasive is sprayed onto the support surface with air at a high speed to roughen the surface, and the surface roughness can be controlled in the same manner as the wet honing process. Examples of the abrasive used in these wet or dry honing processes include particles such as silicon carbide, alumina, zirconia, stainless steel, iron, glass beads, and plastic shots.

  However, in dry honing and liquid honing using amorphous alumina abrasive grains, the abrasive grains may pierce the surface of the support, and when an electrophotographic photosensitive member is produced, black spots on white images in the reversal development system, normal rotation It appears as white spots on a black image in the development system. In liquid honing using glass beads, it is difficult to control the roughness because the glass breaks immediately and pierces the support surface. Therefore, after roughening the support by liquid honing using spherical alumina abrasive grains or stainless abrasive grains as an abrasive, an undercoat layer and a photosensitive layer are formed to produce an electrophotographic photoreceptor. It is common. Further, in the roughening treatment of the support, an interference fringe prevention function from the viewpoint of processing time, amount of abrasive grains used, amount of energy consumption, and ease of removing residual abrasive grains from the roughened substrate. It is preferable to make the treatment conditions as mild as possible within the range satisfying the above and to keep the surface roughness (Rz) small.

(Image forming method and image forming apparatus)
The image forming apparatus of the present invention comprises at least an electrophotographic photosensitive member, a charging unit, an exposure unit, a developing unit, and a transfer unit, and other units appropriately selected as necessary, for example, The image forming apparatus includes a fixing unit, a cleaning unit, a charge eliminating unit, a recycling unit, a control unit, and the like.
The electrophotographic photoreceptor is the electrophotographic photoreceptor of the present invention.
At this time, the image forming apparatus according to the present invention includes the above-described electrophotographic photosensitive member, a charging unit for charging the electrophotographic photosensitive member, and an electrostatic latent image on the surface of the electrophotographic photosensitive member charged by the charging unit. Latent image forming means to be formed, developing means for forming a toner image by attaching toner to an image portion of an electrostatic latent image formed by the latent image forming means, and an electrophotographic photoreceptor after the toner image has been transferred An image forming apparatus process cartridge that is integrally provided with one or two or more means selected from cleaning means for removing toner remaining on the surface is mounted, and the image forming apparatus process cartridge is detachable. Is preferred.

The image forming method used in the present invention includes at least a charging step, an exposure step, a development step, and a transfer step, and other steps appropriately selected as necessary, such as a fixing step and a cleaning step. , A static elimination process, a recycling process, a control process, and the like.
That is, an image forming method according to the present invention includes a charging step for charging an electrophotographic photosensitive member, a latent image forming step for forming an electrostatic latent image on the surface of the electrophotographic photosensitive member charged by the charging step, A developing step for forming a toner image by attaching toner to an image portion of the electrostatic latent image formed by the latent image forming step; a transferring step for transferring the toner image formed by the developing step to a transfer target; And a cleaning step for removing toner remaining on the surface of the electrophotographic photosensitive member after the transfer step, and the electrophotographic photosensitive member is the above-described electrophotographic photosensitive member.
The image forming method used in the present invention can be preferably implemented by the image forming apparatus of the present invention, the charging step can be performed by the charging unit, and the exposure step can be performed by the exposing unit. The developing step can be performed by the developing unit, the transferring step can be performed by the transferring unit, the fixing step can be performed by the fixing unit, and the cleaning step can be performed by the cleaning unit. The other steps can be performed by the other means.

-Charging step and charging means-
The charging step is a step of charging the surface of the electrophotographic photosensitive member, and is performed by the charging unit.
The charging means is not particularly limited as long as it can uniformly apply a voltage to the surface of the electrophotographic photosensitive member, and can be appropriately selected depending on the purpose. A non-contact charging means for charging the photoconductor in a non-contact manner is used.
As the non-contact charging means, for example, a non-contact charger using a corona discharge, a needle electrode device, a solid discharge element; conductive or semiconductive disposed with a minute gap with respect to the electrophotographic photosensitive member And a charging roller. Among these, corona discharge is particularly preferable.
The corona discharge is a non-contact charging method that gives positive or negative ions generated by corona discharge in the air to the surface of the electrophotographic photosensitive member, and has a characteristic of giving a certain amount of charge to the electrophotographic photosensitive member. There are a charger and a scorotron charger having a characteristic of giving a constant potential.
The coroton charger is composed of a casing electrode that occupies a half space around the discharge wire, and a discharge wire placed almost at the center thereof.
The scorotron charger is obtained by adding a grid electrode to the corotron charger, and the grid electrode is provided at a position 1.0 mm to 2.0 mm away from the surface of the electrophotographic photosensitive member.

-Exposure process and exposure means-
The exposure can be performed, for example, by exposing the surface of the electrophotographic photosensitive member imagewise using the exposure unit.
The optical system in the exposure is roughly classified into an analog optical system and a digital optical system. The analog optical system is an optical system that projects a document directly onto an electrophotographic photosensitive member by an optical system, and the digital optical system receives image information as an electrical signal, converts it into an optical signal, and converts it into an electrophotographic image. It is an optical system that exposes a photoreceptor and forms an image.
The exposure unit is not particularly limited as long as the surface of the electrophotographic photosensitive member charged by the charging unit can be exposed like an image to be formed, and can be appropriately selected according to the purpose. However, various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, a liquid crystal shutter optical system, and an LED optical system can be used.
In the present invention, an optical backside system that performs imagewise exposure from the backside of the electrophotographic photosensitive member may be employed.

-Development process and development means-
The developing step is a step of developing the electrostatic latent image using a toner or a developer to form a visible image.
The visible image can be formed, for example, by developing the electrostatic latent image using the toner or the developer, and can be performed by the developing unit.
The developing means is not particularly limited as long as it can be developed using, for example, the toner or the developer, and can be appropriately selected from known ones. For example, the toner or developer is accommodated. Preferred examples include those having at least a developing unit capable of bringing the toner or developer into contact or non-contact with the electrostatic latent image.
The developing unit may be a dry developing type, a wet developing type, a single color developing unit, or a multi-color developing unit. For example, a toner having a stirrer for charging the toner or the developer by frictional stirring and a rotatable magnet roller is preferable.
In the developing device, for example, the toner and the carrier 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 electrophotographic photosensitive member (photosensitive member), a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is caused by an electric attractive force. It moves to the surface of the electrophotographic photoreceptor. As a result, the electrostatic latent image is developed with the toner, and a visible image is formed with the toner on the surface of the electrophotographic photosensitive member.
The developer accommodated in the developing device is a developer containing the toner, but the developer may be a one-component developer or a two-component developer.

-Transfer process and transfer means-
The transfer step is a step of transferring the visible image onto a recording medium. After the primary transfer of the visible image onto the intermediate transfer member using an intermediate transfer member, the visible image is transferred onto the recording medium. A primary transfer step of forming a composite transfer image by transferring a visible image onto an intermediate transfer body using two or more colors, preferably a full color toner, as the toner, and a composite transfer image; A mode including a secondary transfer step of transferring the transfer image onto the recording medium is more preferable.
The transfer can be performed, for example, by charging the electrophotographic photosensitive member with the transfer charger using the visible image, and can be performed by the transfer unit. The transfer 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.
The intermediate transfer member is not particularly limited and may be appropriately selected from known transfer members according to the purpose. For example, a transfer belt and the like are preferable.
The transfer unit (the primary transfer unit and the secondary transfer unit) includes at least a transfer unit that peels and charges the visible image formed on the electrophotographic photosensitive member toward the recording medium. preferable. 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. PET for OHP A base or the like 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 using a fixing device, and may be performed each time the toner of each color is transferred to the recording medium, or for the toner of each color. You may perform this simultaneously in the state which laminated | stacked this.
The fixing unit is not particularly limited and may be appropriately selected depending on the intended purpose. A fixing unit and a heat source for heating the fixing member are used.
Examples of the fixing member include a combination of an endless belt and a roller, a combination of a roller and a roller, etc., but the warm-up time can be shortened, and in terms of realizing energy saving, A combination of an endless belt and a roller having a small heat capacity is preferable in terms of expansion of the fixable width.

-Cleaning process and cleaning means-
The cleaning step is a step of removing the toner remaining on the electrophotographic photosensitive member, and can be suitably performed by a cleaning unit. In addition, it is also possible to employ a method in which the charge of the residual toner is made uniform by the rubbing member and collected by the developing roller without using the cleaning means.
The cleaning means is not particularly limited as long as it can remove the electrophotographic toner remaining on the electrophotographic photosensitive member, and can be appropriately selected from known cleaners. For example, a magnetic brush cleaner Suitable examples include electrostatic brush cleaners, magnetic roller cleaners, blade cleaners, brush cleaners, web cleaners, and the like.

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

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

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

Next, the image forming apparatus and the process cartridge of the present invention will be described in detail with reference to the drawings.
The image forming apparatus of the present invention uses the electrophotographic photosensitive member of the present invention. For example, at least after the photosensitive member is charged, exposed to an image, and developed, the toner image is transferred to an image holding member (transfer paper). And a process of fixing and cleaning the surface of the photoreceptor.
In some cases, an image forming apparatus that directly transfers an electrostatic latent image to a recording medium and develops it does not necessarily have the above-described process disposed on a photoconductor.

  FIG. 5 is a schematic diagram illustrating an example of an image forming apparatus. A charging charger 3 is used as a means for charging the photosensitive member on average. As the charging means, a corotron device, a scorotron device, a solid discharge element, a needle electrode device, a roller charging device, a conductive brush device, or the like is used, and a known system can be used.

  Next, the image exposure unit 5 is used to form an electrostatic latent image on the uniformly charged photoreceptor 1. As the light source, all luminescent materials such as a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), and an electroluminescence (EL) can be used. Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.

  Next, the developing unit 6 is used to visualize the electrostatic latent image formed on the photoreceptor 1. Development methods include a one-component development method using a dry toner, a two-component development method, and a wet development method using a wet toner. When the photosensitive member is positively (negatively) charged and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. A positive image can be obtained by developing this with negative (positive) toner (electrodetection fine particles), and a negative image can be obtained by developing with positive (negative) toner.

  Next, a transfer charger 10 is used to transfer the toner image visualized on the photoreceptor onto the recording medium 9. In addition, a pre-transfer charger 7 may be used for better transfer. As these transfer means, a transfer charger, an electrostatic transfer method using a bias roller, a mechanical transfer method such as an adhesive transfer method and a pressure transfer method, and a magnetic transfer method can be used. As the electrostatic transfer method, those used for the charging means can be used.

  Next, a separation charger 11 and a separation claw 12 are used as means for separating the recording medium 9 from the photoreceptor 1. As other separation means, electrostatic adsorption induction separation, side end belt separation, tip grip conveyance, curvature separation, and the like are used. As the separation charger 11, the charging means can be used.

  Next, a fur brush 14 and a cleaning blade 15 are used to clean the toner remaining on the photoconductor after transfer. Further, a pre-cleaning charger 13 may be used in order to perform cleaning more efficiently. Other cleaning means include a web method, a magnet brush method, and the like, but each may be used alone or in combination.

  Further, a charge eliminating unit is used for the purpose of removing the latent image on the photosensitive member as necessary. As the discharging means, a discharging lamp 2 and a discharging charger are used, and those used for the exposure light source and the charging means can be used.

  In addition, known processes can be used for reading, feeding, fixing, paper discharge and the like that are not close to the photoconductor.

  The present invention is an image forming method and an image forming apparatus using the electrophotographic photoreceptor according to the present invention for such image forming means.

  The image forming means may be fixedly incorporated in a copying apparatus, facsimile, or printer, but may be incorporated in these apparatuses in the form of a process cartridge and detachable. An example of the process cartridge is shown in FIG.

The process cartridge includes a photosensitive member 101, and further includes at least one of a charging unit 102, a developing unit 104, a transfer unit 106, a cleaning unit 107, and a charge eliminating unit (not shown). It is a device (part) that is detachable.
The process cartridge for an image forming apparatus according to the present invention includes the above-described electrophotographic photosensitive member 101, a charging unit 102 that charges the electrophotographic photosensitive member 101, and the electrophotographic photosensitive member 101 that is charged by the charging unit 102. A latent image forming means (not shown) for forming an electrostatic latent image on the surface; a developing means 104 for forming a toner image by attaching toner to an image portion of the electrostatic latent image formed by the latent image forming means; One or two or more means selected from cleaning means 107 that removes toner remaining on the surface of the electrophotographic photosensitive member 101 after the toner image is transferred, and is detachable from the main body of the image forming apparatus. preferable.

  The image forming process using the process cartridge of FIG. 6 will be described. The photosensitive member 101 is charged by the charging unit 102 and exposed by the exposure unit 103 while rotating in the direction of the arrow. The electrostatic latent image is developed with toner by the developing unit 104, and the toner development is transferred to the recording medium 105 by the transfer unit 106 and printed out. Next, the surface of the photoconductor after the image transfer is cleaned by the cleaning unit 107 and further neutralized by a neutralizing unit (not shown), and the above operation is repeated again.

  Since the image forming method, the image forming apparatus, and the process cartridge of the present invention use the electrophotographic photosensitive member of the present invention, the deterioration of electrophotographic characteristics such as a decrease in chargeability is extremely small even after long-term use. It is possible to continuously obtain a high-quality image with less image quality.

  EXAMPLES Next, although an Example demonstrates this invention in detail, this invention is not limited to a following example.

<Example 1>
An undercoat layer coating solution having the following composition was applied on a φ30 mm aluminum cylinder and then dried at 130 ° C. for 30 minutes to form a 3.5 μm undercoat layer.

[Coating liquid for undercoat layer]
・ Alkyd resin 6 parts by weight (Beckosol 1307-60-EL, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 4 parts by weight (Super Becamine G-821-60, manufactured by Dainippon Ink and Chemicals)
・ Titanium oxide 40 parts by weight ・ Methyl ethyl ketone 50 parts by weight

  Next, the resin shown below was mixed with a bead mill disperser (using a zirconia ball having a diameter of 0.2 mm as a medium) for 70 minutes to produce a charge generation layer coating solution, which was prepared as described above. A charge generation layer was applied to the surface of the undercoat layer, and then dried for 20 minutes in an atmosphere at 95 ° C. to form a charge generation layer having an average film thickness of 0.21 μm.

[Coating liquid for charge generation layer]
-12 parts by weight of titanyl phthalocyanine pigment prepared according to Synthesis Example 1 described below-8 parts by weight of polyvinyl butyral (manufactured by Sekisui Chemical: ESREC BX-1)
・ 266 parts by weight of cyclohexanone

(Synthesis example 1 of titanyl phthalocyanine)
A pigment was prepared according to Japanese Patent Application Laid-Open No. 2001-19871. That is, 29.2 g of 1,3-diiminoisoindoline and 200 ml of sulfolane are mixed, and 20.4 g of titanium tetrabutoxide is added dropwise under a nitrogen stream. After completion of the dropwise addition, the temperature was gradually raised to 180 ° C., and the reaction was carried out by stirring for 5 hours while maintaining the reaction temperature between 170 ° C. and 180 ° C. After completion of the reaction, the mixture was allowed to cool and then the precipitate was filtered, washed with chloroform until the powder turned blue, then washed several times with methanol, further washed several times with hot water at 80 ° C. and dried, Crude titanyl phthalocyanine was obtained. Dissolve the crude titanyl phthalocyanine in 20 times the amount of concentrated sulfuric acid, add dropwise to 100 times the amount of ice water with stirring, filter the precipitated crystals, and then repeat washing with water until the washing solution becomes neutral (ion-exchanged water after washing). PH value was 6.8), and a titanyl phthalocyanine pigment wet cake (water paste) was obtained. 40 g of the obtained wet cake (water paste) was put into 200 g of tetrahydrofuran, stirred for 4 hours, filtered and dried to obtain titanyl phthalocyanine powder. This is designated as Pigment 1.
The solid content concentration of the wet cake was 15 wt%. The weight ratio of the crystal conversion solvent to the wet cake is 33 times.
The obtained titanyl phthalocyanine powder was subjected to X-ray diffraction spectrum measurement under the following conditions. As a result, the Bragg angle 2θ with respect to the characteristic X-ray of Cu—Kα (wavelength: 1.542 mm) was 27.2 ± 0.2 ° with the maximum peak. Has a peak at the lowest angle of 7.3 ± 0.2 °, no peak between 7.3 ° peak and 9.4 ° peak, and no peak at 26.3 ° A titanyl phthalocyanine powder was obtained. The result of the X-ray diffraction is shown in FIG.

(X-ray diffraction spectrum measurement conditions)
X-ray tube: Cu
Voltage: 50kV
Current: 30mA
Scanning speed: 2 ° / min Scanning range: 3 ° -40 °
Time constant: 2 seconds

  The average particle size in the charge generation layer coating solution using titanyl phthalocyanine was measured by CAPA-700 manufactured by HORIBA, Ltd. and found to be 0.29 μm.

  Next, a charge transport layer coating liquid having the following composition was applied to the surface of the charge generation layer prepared as described above, and then dried at 130 degrees for 30 minutes to form an 18 μm charge transport layer layer.

[Coating liquid for charge transport layer]
-10 parts by weight of bisphenol Z polycarbonate (Panlite TS-2050, manufactured by Teijin Chemicals)
-7 parts by weight of low molecular charge transport material of the following structural formula (1)-100 parts by weight of tetrahydrofuran-1 part by weight of tetrahydrofuran solution of 1% silicone oil (KF50-100CS, manufactured by Shin-Etsu Chemical Co., Ltd.)

Next, a surface layer coating solution having the following composition was applied onto the laminate comprising the conductive support / undercoat layer / charge generation layer / charge transport layer using a spray coating method, and then a metal halide lamp was used to generate illuminance. : 900 mW / cm ² , Irradiation time: The surface layer was crosslinked by light irradiation under the conditions of 120 seconds to obtain a cured surface film of 5.0 μm. Thereafter, drying was performed at 130 ° C. for 30 minutes to obtain an electrophotographic photosensitive member comprising a conductive support / undercoat layer / charge generation layer / charge transport layer / surface layer.

[Coating liquid for surface layer]
-Carbazole compound having no radically polymerizable functional group (I-3) 5 parts by weight (see paragraph [0051])
-Carbazole compound having a radical polymerizable functional group (II-1) 5 parts by weight (see paragraph [0062])
Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
・ 57 parts by weight of tetrahydrofuran

<Example 2>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the carbazole compound having no radical polymerizable functional group used in the surface layer coating solution of Example 1 was changed to the following.

-Carbazole compound having no radically polymerizable functional group (I-10) 5 parts by weight (see paragraph [0051])

<Example 3>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the carbazole compound having no radical polymerizable functional group used in the surface layer coating solution of Example 1 was changed to the following.

-Carbazole compound having no radically polymerizable functional group (I-20) 5 parts by weight (see paragraph [0052])

<Examples 4 to 6>
An electrophotographic photosensitive member was produced in the same manner as in Examples 1 to 3 except that the carbazole compound having a radical polymerizable functional group used in the surface layer coating liquid of Examples 1 to 3 was changed to the following.

-Carbazole compound having a radical polymerizable functional group (II-6) 5 parts by weight (see paragraph [0062])

<Examples 7 to 9>
An electrophotographic photosensitive member was produced in the same manner as in Examples 1 to 3 except that the carbazole compound having a radical polymerizable functional group used in the surface layer coating liquid of Examples 1 to 3 was changed to the following.

-Carbazole compound having a radical polymerizable functional group (II-9) 5 parts by weight (see paragraph [0063])

<Examples 10 to 12>
An electrophotographic photosensitive member was produced in the same manner as in Examples 1 to 3 except that the carbazole compound having a radical polymerizable functional group used in the surface layer coating liquid of Examples 1 to 3 was changed to the following.

-Carbazole compound having a radical polymerizable functional group (III-1) 5 parts by weight (see paragraph [0064])

<Examples 13 to 15>
An electrophotographic photosensitive member was produced in the same manner as in Examples 1 to 3 except that the carbazole compound having a radical polymerizable functional group used in the surface layer coating liquid of Examples 1 to 3 was changed to the following.

-Carbazole compound having a radical polymerizable functional group (III-4) 5 parts by weight (see paragraph [0064])

<Examples 16 to 18>
An electrophotographic photosensitive member was produced in the same manner as in Examples 1 to 3 except that the carbazole compound having a radical polymerizable functional group used in the surface layer coating liquid of Examples 1 to 3 was changed to the following.

  -Carbazole compound having a radical polymerizable functional group (III-5) 5 parts by weight

<Example 19>
An electrophotographic photosensitive member was produced in the same manner as in Example 2 except that the surface layer coating solution in Example 2 was changed to the following.

[Coating liquid for surface layer]
-Carbazole compound having no radically polymerizable functional group (I-10) 2 parts by weight (see paragraph [0051])
-Carbazole compound having a radical polymerizable functional group (II-1) 8 parts by weight (see paragraph [0062])
Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
・ 57 parts by weight of tetrahydrofuran

<Example 20>
An electrophotographic photosensitive member was produced in the same manner as in Example 2 except that the surface layer coating solution in Example 2 was changed to the following.

[Coating liquid for surface layer]
-Carbazole compound having no radically polymerizable functional group (I-10) 6 parts by weight (see paragraph [0051])
-Carbazole compound having a radical polymerizable functional group (II-1) 4 parts by weight (see paragraph [0062])
Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
・ 57 parts by weight of tetrahydrofuran

<Example 21>
An electrophotographic photosensitive member was produced in the same manner as in Example 2 except that the surface layer coating solution in Example 2 was changed to the following.

[Coating liquid for surface layer]
-Carbazole compound having no radically polymerizable functional group (I-10) 2 parts by weight (see paragraph [0051])
-Carbazole compound having a radical polymerizable functional group (III-1) 8 parts by weight (see paragraph [0064])
Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
・ 57 parts by weight of tetrahydrofuran

<Example 22>
An electrophotographic photosensitive member was produced in the same manner as in Example 2 except that the surface layer coating solution in Example 2 was changed to the following.

[Coating liquid for surface layer]
-Carbazole compound having no radically polymerizable functional group (I-10) 6 parts by weight (see paragraph [0051])
-Carbazole compound having a radical polymerizable functional group (III-1) 4 parts by weight (see paragraph [0064])
Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
・ 57 parts by weight of tetrahydrofuran

<Example 23>
An electrophotographic photosensitive member was produced in the same manner as in Example 2 except that the surface layer coating solution of Example 2 was changed to the following one in which inorganic fine particles were dispersed.

[Coating liquid for surface layer]
-Carbazole compound having no radically polymerizable functional group (I-10) 5 parts by weight (see paragraph [0051])
-Carbazole compound having a radical polymerizable functional group (II-1) 5 parts by weight (see paragraph [0062])
Alumina fine particles (AA03, manufactured by Sumitomo Chemical Co., Ltd.) 10.4 parts by weight Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
Tetrahydrofuran 90.8 parts by weight Cyclohexanone 26 parts by weight

<Example 24>
An electrophotographic photosensitive member was produced in the same manner as in Example 2 except that the surface layer coating solution of Example 2 was changed to the following one in which inorganic fine particles were dispersed.

[Coating liquid for surface layer]
-Carbazole compound having no radically polymerizable functional group (I-10) 5 parts by weight (see paragraph [0051])
-Carbazole compound having a radical polymerizable functional group (II-1) 5 parts by weight (see paragraph [0062])
Tin oxide fine particles (SN-100P, manufactured by Ishihara Sangyo Co., Ltd.) 18.2 parts by weight Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, Ciba Specialty Chemicals) Made)
Tetrahydrofuran 125.1 parts by weight Cyclohexanone 35.7 parts by weight

<Example 25>
An electrophotographic photosensitive member was produced in the same manner as in Example 2 except that the surface layer coating solution of Example 2 was changed to the following one in which inorganic fine particles were dispersed.

[Coating liquid for surface layer]
-Carbazole compound having no radically polymerizable functional group (I-10) 5 parts by weight (see paragraph [0051])
-Carbazole compound having a radical polymerizable functional group (II-1) 5 parts by weight (see paragraph [0062])
-Titania fine particles (CR-EL, manufactured by Ishihara Sangyo) 11.0 parts by weight-Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals) )
-Tetrahydrofuran 93.4 parts by weight-Cyclohexanone 257 parts by weight

<Example 26>
An electrophotographic photosensitive member was produced in the same manner as in Example 2 except that the surface layer coating solution of Example 2 was changed to the following one in which inorganic fine particles were dispersed.

[Coating liquid for surface layer]
-Carbazole compound having no radically polymerizable functional group (I-10) 5 parts by weight (see paragraph [0051])
-Carbazole compound having a radical polymerizable functional group (II-1) 5 parts by weight (see paragraph [0062])
Silica fine particles (KMPX100, manufactured by Shin-Etsu Chemical Co., Ltd.) 5.8 parts by weight Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
Tetrahydrofuran 70.3 parts by weight Cyclohexanone 20.1 parts by weight

<Example 27>
An electrophotographic photosensitive member was produced in the same manner as in Example 2 except that the surface layer coating solution of Example 11 was changed to the following one in which inorganic fine particles were dispersed.

[Coating liquid for surface layer]
-Carbazole compound having no radically polymerizable functional group (I-10) 5 parts by weight (see paragraph [0051])
-Carbazole compound having a radical polymerizable functional group (III-1) 5 parts by weight (see paragraph [0064])
-Alumina fine particles (AA03, manufactured by Sumitomo Chemical Co., Ltd.) 16.8 parts by weight-Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
Tetrahydrofuran 119.1 parts by weight Cyclohexanone 34.0 parts by weight

<Example 28>
An electrophotographic photosensitive member was produced in the same manner as in Example 2 except that the surface layer coating solution of Example 11 was changed to the following one in which inorganic fine particles were dispersed.

[Coating liquid for surface layer]
-Carbazole compound having no radically polymerizable functional group (I-10) 5 parts by weight (see paragraph [0051])
-Carbazole compound having a radical polymerizable functional group (III-1) 5 parts by weight (see paragraph [0064])
Alumina fine particles (AA03, manufactured by Sumitomo Chemical Co., Ltd.) 10.4 parts by weight Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
Tetrahydrofuran 90.8 parts by weight Cyclohexanone 26.0 parts by weight

<Example 29>
An electrophotographic photosensitive member was produced in the same manner as in Example 2 except that the surface layer coating solution of Example 11 was changed to the following one in which inorganic fine particles were dispersed.

[Coating liquid for surface layer]
-Carbazole compound having no radically polymerizable functional group (I-10) 5 parts by weight (see paragraph [0051])
-Carbazole compound having a radical polymerizable functional group (III-1) 5 parts by weight (see paragraph [0064])
Alumina fine particles (AA03, manufactured by Sumitomo Chemical Co., Ltd.) 3.5 parts by weight Photoinitiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
Tetrahydrofuran 60.2 parts by weight Cyclohexanone 17.2 parts by weight

<Example 30>
An electrophotographic photosensitive member was produced in the same manner as in Example 2 except that the surface layer coating solution of Example 11 was changed to the following one in which inorganic fine particles were dispersed.

[Coating liquid for surface layer]
-Carbazole compound having no radically polymerizable functional group (I-10) 5 parts by weight (see paragraph [0051])
-Carbazole compound having a radical polymerizable functional group (III-1) 5 parts by weight (see paragraph [0064])
Tin oxide fine particles (SN-100P, manufactured by Ishihara Sangyo Co., Ltd.) 18.2 parts by weight Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, Ciba Specialty Chemicals) Made)
Tetrahydrofuran 125.1 parts by weight Cyclohexanone 35.7 parts by weight

<Example 31>
An electrophotographic photosensitive member was produced in the same manner as in Example 2 except that the surface layer coating solution of Example 11 was changed to the following one in which inorganic fine particles were dispersed.

[Coating liquid for surface layer]
-Carbazole compound having no radically polymerizable functional group (I-10) 5 parts by weight (see paragraph [0051])
-Carbazole compound having a radical polymerizable functional group (III-1) 5 parts by weight (see paragraph [0064])
-Titania fine particles (CR-EL, manufactured by Ishihara Sangyo) 11.0 parts by weight-Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals) )
-Tetrahydrofuran 93.4 parts by weight-Cyclohexanone 257 parts by weight

<Example 32>
An electrophotographic photosensitive member was produced in the same manner as in Example 2 except that the surface layer coating solution of Example 11 was changed to the following one in which inorganic fine particles were dispersed.

[Coating liquid for surface layer]
-Carbazole compound having no radically polymerizable functional group (I-10) 5 parts by weight (see paragraph [0051])
-Carbazole compound having a radical polymerizable functional group (III-1) 5 parts by weight (see paragraph [0064])
Silica fine particles (KMPX100, manufactured by Shin-Etsu Chemical Co., Ltd.) 5.8 parts by weight Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
Tetrahydrofuran 70.3 parts by weight Cyclohexanone 20.1 parts by weight

<Example 33>
An electrophotographic photosensitive member was produced in the same manner as in Example 2 except that the surface layer coating solution of Example 2 was changed to one containing a radical polymerizable compound having no carbazole skeleton having the following structural formula.

[Coating liquid for surface layer]
-Carbazole compound having no radically polymerizable functional group (I-10) 5 parts by weight (see paragraph [0051])
-Carbazole compound having a radical polymerizable functional group (II-1) 5 parts by weight (see paragraph [0062])
-Radical polymerizable compound represented by the following structural formula (2) 5 parts by weight (TMPTA, manufactured by Tokyo Chemical Industry Co., Ltd.)
Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
・ 86.1 parts by weight of tetrahydrofuran

<Example 34>
An electrophotographic photosensitive member was produced in the same manner as in Example 2 except that the surface layer coating solution of Example 2 was changed to one containing a radical polymerizable compound having no carbazole skeleton having the following structural formula.

[Coating liquid for surface layer]
-Carbazole compound having no radically polymerizable functional group (I-10) 5 parts by weight (see paragraph [0051])
-Carbazole compound having a radical polymerizable functional group (II-1) 5 parts by weight (see paragraph [0062])
-5 parts by weight of a radically polymerizable compound represented by the following structural formula (3) (KAYARAD DPCA-120, manufactured by Nippon Kayaku Co., Ltd.)
Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
・ 86.1 parts by weight of tetrahydrofuran

<Example 35>
An electrophotographic photosensitive member was produced in the same manner as in Example 2 except that the surface layer coating solution of Example 2 was changed to one containing a radical polymerizable compound having no carbazole skeleton having the following structural formula.

[Coating liquid for surface layer]
-Carbazole compound having no radically polymerizable functional group (I-10) 5 parts by weight (see paragraph [0051])
-Carbazole compound having a radical polymerizable functional group (II-1) 5 parts by weight (see paragraph [0062])
・ Radically polymerizable compound 5 parts by weight (1,6-hexanediol diacrylate (manufactured by Wako Pure Chemical Industries))
Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
・ 86.1 parts by weight of tetrahydrofuran

<Examples 36 to 38>
Electrophotographic photoreceptors were produced in the same manner as in Examples 33 to 35 except that the carbazole compounds having radical polymerizable functional groups used in the surface layer coating liquids of Examples 33 to 35 were changed to the following.

-Carbazole compound having a radical polymerizable functional group (III-1) 5 parts by weight (see paragraph [0061])

<Examples 39 to 40>
Electrophotographic photosensitive members were produced in the same manner as in Examples 2 and 11, except that the charge generation layer coating solutions in Examples 2 and 11 were changed to the following.

[Coating liquid for charge generation layer]
-2.5 parts by weight of a bisazo pigment represented by the following structural formula (4)-0.5 parts by weight of polyvinyl butyral (XYHL, manufactured by UCC)-200 parts by weight of cyclohexanone-80 parts by weight of methyl ethyl ketone

<Example 41>
An electrophotographic photosensitive member was produced in the same manner as in Example 2 except that the surface layer coating solution in Example 2 was changed to the following.

[Coating liquid for surface layer]
-Carbazole compound having no radically polymerizable functional group (I-10) 1 part by weight (see paragraph [0051])
-Carbazole compound having a radical polymerizable functional group (II-1) 9 parts by weight (see paragraph [0062])
Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
・ 57 parts by weight of tetrahydrofuran

<Example 42>
An electrophotographic photosensitive member was produced in the same manner as in Example 2 except that the surface layer coating solution in Example 2 was changed to the following.

[Coating liquid for surface layer]
-Carbazole compound having no radically polymerizable functional group (I-10) 7 parts by weight (see paragraph [0051])
-Carbazole compound having a radical polymerizable functional group (II-1) 3 parts by weight (see paragraph [0062])
Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
・ 57 parts by weight of tetrahydrofuran

<Example 43>
An electrophotographic photosensitive member was produced in the same manner as in Example 11 except that the surface layer coating solution in Example 11 was changed to the following.

[Coating liquid for surface layer]
-Carbazole compound having no radically polymerizable functional group (I-10) 1 part by weight (see paragraph [0051])
-Carbazole compound having a radical polymerizable functional group (III-1) 9 parts by weight (see paragraph [0064])
Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
・ 57 parts by weight of tetrahydrofuran

<Example 44>
An electrophotographic photosensitive member was produced in the same manner as in Example 11 except that the surface layer coating solution in Example 11 was changed to the following.

[Coating liquid for surface layer]
-Carbazole compound having no radically polymerizable functional group (I-10) 7 parts by weight (see paragraph [0051])
-Carbazole compound having a radical polymerizable functional group (III-1) 3 parts by weight (see paragraph [0064])
Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
・ 57 parts by weight of tetrahydrofuran

<Example 45>
An electrophotographic photosensitive member was produced in the same manner as in Example 2 except that the surface layer coating solution of Example 2 was changed to the following one in which inorganic fine particles were dispersed.

[Coating liquid for surface layer]
-Carbazole compound having no radically polymerizable functional group (I-10) 5 parts by weight (see paragraph [0051])
-Carbazole compound having a radical polymerizable functional group (II-1) 5 parts by weight (see paragraph [0062])
Alumina fine particles (AA03, manufactured by Sumitomo Chemical Co., Ltd.) 31.2 parts by weight Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
Tetrahydrofuran 182.6 parts by weight Cyclohexanone 52.2 parts by weight

<Example 46>
An electrophotographic photosensitive member was produced in the same manner as in Example 2 except that the surface layer coating solution of Example 2 was changed to the following one in which inorganic fine particles were dispersed.

[Coating liquid for surface layer]
-Carbazole compound having no radically polymerizable functional group (I-10) 5 parts by weight (see paragraph [0051])
-Carbazole compound having a radical polymerizable functional group (II-1) 5 parts by weight (see paragraph [0062])
Alumina fine particles (AA03, manufactured by Sumitomo Chemical Co., Ltd.) 1.6 parts by weight Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
Tetrahydrofuran 52.2 parts by weight Cyclohexanone 14.9 parts by weight

<Example 47>
An electrophotographic photosensitive member was produced in the same manner as in Example 11 except that the surface layer coating solution of Example 11 was changed to the following one in which inorganic fine particles were dispersed.

[Coating liquid for surface layer]
-Carbazole compound having no radically polymerizable functional group (I-10) 5 parts by weight (see paragraph [0051])
-Carbazole compound having a radical polymerizable functional group (III-1) 5 parts by weight (see paragraph [0064])
Alumina fine particles (AA03, manufactured by Sumitomo Chemical Co., Ltd.) 31.2 parts by weight Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
Tetrahydrofuran 182.6 parts by weight Cyclohexanone 52.2 parts by weight

<Example 48>
An electrophotographic photosensitive member was produced in the same manner as in Example 11 except that the surface layer coating solution of Example 11 was changed to the following one in which inorganic fine particles were dispersed.

[Coating liquid for surface layer]
-Carbazole compound having no radically polymerizable functional group (I-10) 5 parts by weight (see paragraph [0051])
-Carbazole compound having a radical polymerizable functional group (III-1) 5 parts by weight (see paragraph [0064])
Alumina fine particles (AA03, manufactured by Sumitomo Chemical Co., Ltd.) 1.6 parts by weight Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
Tetrahydrofuran 52.2 parts by weight Cyclohexanone 14.9 parts by weight

<Examples 49 to 51>
An electrophotographic photosensitive member was produced in the same manner as in Examples 1 to 3 except that the carbazole compound having a radical polymerizable functional group used in the surface layer coating liquid of Examples 1 to 3 was changed to the following.

-Carbazole compound having a radical polymerizable functional group (II-13) 5 parts by weight (see paragraph [0063])

<Examples 52 to 54>
An electrophotographic photosensitive member was produced in the same manner as in Examples 1 to 3 except that the carbazole compound having a radical polymerizable functional group used in the surface layer coating liquid of Examples 1 to 3 was changed to the following.

-Carbazole compound having a radical polymerizable functional group (III-12) 5 parts by weight (see paragraph [0066])

<Comparative Example 1>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the surface layer coating solution in Example 1 was changed to the following.

[Coating liquid for surface layer]
-Carbazole compound having no radically polymerizable functional group (I-3) 5 parts by weight (see paragraph [0051])
-Bisphenol Z modified polycarbonate 5 parts by weight (Panlite TS-2050, manufactured by Teijin Chemicals Ltd.)
Tetrahydrofuran 251.2 parts by weight Cyclohexanone 71.8 parts by weight

<Comparative example 2>
An electrophotographic photosensitive member was produced in the same manner as in Comparative Example 1 except that the carbazole compound having no radical polymerizable functional group used in the surface layer coating solution of Comparative Example 1 was changed to the following.

-Carbazole compound having no radically polymerizable functional group (I-10) 5 parts by weight (see paragraph [0051])

<Comparative Example 3>
An electrophotographic photosensitive member was produced in the same manner as in Comparative Example 1 except that the carbazole compound having no radical polymerizable functional group used in the surface layer coating solution of Comparative Example 1 was changed to the following.

-Carbazole compound having no radically polymerizable functional group (I-20) 5 parts by weight (see paragraph [0052])

<Comparative Examples 4-6>
An electrophotographic photosensitive member was produced in the same manner as in Comparative Examples 1 to 3, except that the surface layer coating solution in Comparative Examples 1 to 3 was changed to the following.

-Carbazole compound having no radically polymerizable functional group (I-3) 5 parts by weight (see paragraph [0051])
-Triphenyl compound having a radical polymerizable functional group represented by the following structural formula (5)
5 parts by weight • Tetrahydrofuran 57 parts by weight

<Comparative Example 7>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the surface layer coating solution in Example 1 was changed to the following.

[Coating liquid for surface layer]
-Carbazole compound having a radical polymerizable functional group (II-1) 10 parts by weight (see paragraph [0062])
Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
・ 57 parts by weight of tetrahydrofuran

<Comparative Example 8>
An electrophotographic photosensitive member was produced in the same manner as in Comparative Example 7, except that the surface layer coating solution in Comparative Example 7 was changed to the following.

[Coating liquid for surface layer]
-Carbazole compound having a radical polymerizable functional group (II-1) 5 parts by weight (see paragraph [0062])
-Radical polymerizable compound represented by the following structural formula (2) 5 parts by weight (TMPTA, manufactured by Tokyo Chemical Industry Co., Ltd.)
Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
・ 57 parts by weight of tetrahydrofuran

<Comparative Examples 9 to 10>
Electrophotographic photosensitive members were produced in the same manner as in Comparative Examples 7-8, except that the surface layer coating liquids of Comparative Examples 7-8 were changed to the following.

[Coating liquid for surface layer]
-Carbazole compound having a radical polymerizable functional group (III-1) 10 parts by weight (see paragraph [0064])
Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
・ 57 parts by weight of tetrahydrofuran

<Comparative Example 11>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the surface layer coating solution in Example 1 was changed to the following.

[Coating liquid for surface layer]
-Carbazole compound having a radical polymerizable functional group (II-1) 5 parts by weight (see paragraph [0062])
-Carbazole compound having a radical polymerizable functional group (III-1) 5 parts by weight (see paragraph [0064])
Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
・ 57 parts by weight of tetrahydrofuran

<Comparative Example 12>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the surface layer coating solution in Example 1 was changed to the following.

[Coating liquid for surface layer]
-Carbazole compound having a radical polymerizable functional group (II-1) 5 parts by weight (see paragraph [0062])
-Carbazole compound having a radical polymerizable functional group (III-1) 5 parts by weight (see paragraph [0064])
-Radical polymerizable compound represented by the following structural formula (2) 5 parts by weight (TMPTA, manufactured by Tokyo Chemical Industry Co., Ltd.)
Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
・ 57 parts by weight of tetrahydrofuran

<Comparative Example 13>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the surface layer coating solution in Example 1 was changed to the following.

[Coating liquid for surface layer]
-Triphenyl compound having no radical polymerizable functional group represented by the following structural formula (1)
5 parts by weight-Carbazole compound having a radical polymerizable functional group (II-1) 5 parts by weight (see paragraph [0062])
Photopolymerization initiator 0.2 parts by weight 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, manufactured by Ciba Specialty Chemicals)
・ 57 parts by weight of tetrahydrofuran

<Comparative example 14>
An electrophotographic photosensitive member was produced in the same manner as in Comparative Examples 7 to 8 except that the surface layer coating solution of Comparative Example 13 was changed to the following.

-Carbazole compound having a radical polymerizable functional group (III-1) 5 parts by weight (see paragraph [0064])

<Comparative Examples 15-16>
Electrophotographic photosensitive members were produced in the same manner as in Comparative Examples 13 to 14 except that the triphenyl compound having no radical polymerizable compound in the surface layer coating liquids of Comparative Examples 13 to 14 was changed to the following.

-Triphenyl compound having no radically polymerizable functional group represented by the following structural formula (7)
5 parts by weight

<Confirmation of film formability (film quality)>
The electrophotographic photoreceptors prepared in Examples 1 to 54 and Comparative Examples 1 to 16 were visually evaluated for film formability. As a result, among the electrophotographic photoreceptors produced in Examples 1 to 54, the photoreceptors of Examples 41 to 44 had a slightly cloudy surface, but a surface layer having generally good film quality was formed.
On the other hand, the surface of the electrophotographic photosensitive member produced in Comparative Examples 4 to 7, 9, and 11 has a surface layer with countless cracks, and it is difficult to use for wear durability evaluation by an actual machine described later. It was.
The electrophotographic photoreceptors produced in Comparative Examples 1 to 3, 8, 10, and 12 to 16 have defects such as surface whitening and partial cracks. No good film formability was observed.

《Abrasion durability evaluation》
The wear durability of the electrophotographic photoreceptors produced in Examples 1-38, 41-54 and Comparative Examples 1-3, 8, 10, and 12-16 was evaluated by the following method.
The produced photosensitive member is mounted on a process cartridge for an electrophotographic apparatus, and the initial dark portion potential is set to −800 V by a Ricoh imgio Neo 271 remodeling machine using a 780 nm semiconductor laser as an image exposure light source. Thereafter, A4 paper passing running was performed, the film thickness was measured at the initial stage and 100,000 sheets, the dark part potential and the exposure part potential were measured as electrical characteristics, and the presence or absence of an output image or more was visually evaluated. The film thickness of the photoconductor was measured using an eddy current film thickness measuring device (manufactured by Fischer Instrument).
Similarly, the wear durability of the electrophotographic photosensitive members produced in Examples 39 to 40 was evaluated using an image exposure light source of the modified machine using a semiconductor laser having a wavelength of 655 nm.

  The evaluation results are shown in Table 8 and Table 9.

From the results of Examples 1 to 54, it was shown that very high wear durability and good electrical properties were exhibited. Particularly, in Examples 10 to 18 and Examples 52 to 54 using the compound represented by the general formula (3), good results were obtained in both wear durability and electrical characteristics. In the present invention, the phenylcarbazole skeleton was obtained. It has been clarified that the use of a radically polymerizable compound having a more excellent property. As described above, the reason for achieving both excellent electrical characteristics and wear durability as described above is that “(a) a charge transport material having a carbazole skeleton has high durability against ultraviolet irradiation”, (B) The non-crosslinkable compound is uniformly dispersed in the film between the cross-linked skeletons having a carbazole skeleton, and the structure-derived hopping conduction inhibition is extremely low. It is speculated that this is related to the fact that crystallization of each other is suppressed by the interaction of the crosslinkable carbazole compound, so that a crosslinked structure can be formed without phase separation.
In Examples 19 to 22, the electrophotographic photosensitive member was prepared by changing the blending ratio of the carbazole compound having a radical polymerizable functional group and the carbazole compound not having a radical polymerizable functional group. It has been clarified that an excellent electrophotographic photosensitive member can be obtained in the blending ratio range of ˜22 without lowering both the electrical characteristics and the wear durability. On the other hand, the blending ratio of both compounds in Examples 41 to 44 resulted in film quality defects such as slight cloudiness on the film surface. However, it was confirmed by an actual paper passing test that the electrophotographic photosensitive members of Examples 41 to 44 had no problem in actual use.
In Examples 23 to 32, an example in which inorganic fine particles were added to the surface layer was shown. It is clear that these electrophotographic photoreceptors show very high wear durability, although a slight decrease in electrical properties is confirmed. It became. This is considered to result from the fact that the inorganic fine particles added to the surface layer exhibit high wear durability against various mechanical hazards in the electrophotographic process. In the present invention, the inorganic fine particles are used in combination. It has been shown that it is possible to achieve both excellent wear durability and extremely stable and good electrical characteristics.
The electrophotographic photoreceptors of Examples 33 to 38 are examples in which a radical polymerizable compound having no carbazole skeleton was applied to the surface layer as a cross-linking component. The wear durability can be confirmed, and by using a radically polymerizable compound having no carbazole skeleton as shown in this example, excellent wear can be achieved by a method other than the addition of inorganic fine particles shown in Examples 23 to 32. It has been found that it can be an electrophotographic photosensitive member forming means having both durability and electrical characteristics.
On the other hand, in Comparative Examples 1 to 16, there are defects such as poor film quality, poor light attenuation, and poor wear durability, and an electrophotographic photosensitive member having a surface layer using the constituent elements described in the present invention. The superiority of was shown.
From the above results, the electrophotographic photoreceptors of the present invention (Examples 1 to 54) exhibit extremely high wear durability, as well as reduced electrical properties / electricity due to material deterioration due to light energy irradiated during surface layer crosslinking. It has been found that the electrophotographic photosensitive member can be used for a long period of time without degradation of characteristic stability and without film defects such as cracks.
From the above results, it has been found that the electrophotographic photosensitive member shown in the present example has little variation in characteristics even with an electrostatic load and has few defects related to image quality over a long period of time.

21 conductive support 22 undercoat layer 23 charge generation layer 24 charge transport layer 25 surface layer 26 photosensitive layer

JP 2001-125286 A JP 2001-324857 A JP 2003-98708 A JP-A-5-181299 JP 2002-6526 A JP 2002-82465 A JP 2000-284514 A JP 2000-284515 A JP 2001-194413 A Japanese Patent No. 3194392 Japanese Patent No. 3286704 JP 2008-233118 A JP 2008-275941 A

Claims (10)

Having at least a photosensitive layer and a surface layer in order on a conductive support;
The surface layer contains a carbazole compound having no radical polymerizable functional group represented by the following general formula (1) and a carbazole compound having a radical polymerizable functional group represented by the following general formula (2). An electrophotographic photoreceptor comprising a polymerization composition produced by irradiating the mixture to be irradiated with light.

[In General Formula (1), R _{1 to} R ₉ are each independently a saturated or unsaturated aliphatic group which may have a hydrogen atom, a nitro group, a cyano group, a halogen atom, a hydroxyl group or a substituent. A hydrocarbon group, an aromatic hydrocarbon group which may have a substituent, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, an amino group, a substituent; represents an diarylamino group also have good dialkylamino groups or substituents have, _{R 3} and _R 4, _{R 4} and _R 5, _{R 6} and _R 7, _{R 7} and _{R 8,} Each may be bonded to each other to form an aromatic ring. ]

[In General Formula (2), each of R _{11 to} R ₁₉ independently represents a saturated or unsaturated aliphatic hydrocarbon or aromatic hydrocarbon having at least one acryloyloxy group or methacryloyloxy group, a hydrogen atom, Group, cyano group, halogen atom, hydroxyl group, saturated or unsaturated aliphatic hydrocarbon group which may have a substituent, aromatic hydrocarbon group which may have a substituent, and substituent Represents an optionally substituted alkoxy group, an optionally substituted aryloxy group, an amino group, an optionally substituted dialkylamino group or an optionally substituted diarylamino group , R ₁₃ and R ₁₄ , R ₁₄ and R ₁₅ , R ₁₆ and R ₁₇ , R ₁₇ and R ₁₈ may be bonded to each other to form an aromatic ring. However, at least one of R _{11 to} R ₁₉ is a saturated or unsaturated aliphatic hydrocarbon or aromatic hydrocarbon having at least one acryloyloxy group or methacryloyloxy group. ] 2. The electrophotographic photoreceptor according to claim 1, wherein the carbazole compound having a radical polymerizable functional group represented by the general formula (2) is a carbazole compound represented by the following general formula (3). .

[In General Formula (3), R _{101 to} R ₁₀₅ each independently represents a saturated or unsaturated aliphatic hydrocarbon or aromatic hydrocarbon having at least one acryloyloxy group or methacryloyloxy group, a hydrogen atom, nitro Group, cyano group, halogen atom, hydroxyl group, saturated or unsaturated aliphatic hydrocarbon group which may have a substituent, aromatic hydrocarbon group which may have a substituent, and substituent Represents an optionally substituted alkoxy group, an optionally substituted aryloxy group, an amino group, an optionally substituted dialkylamino group or an optionally substituted diarylamino group R _{12 to} R ₁₉ have a hydrogen atom, a nitro group, a cyano group, a halogen atom, a hydroxyl group, a saturated or unsaturated aliphatic hydrocarbon group which may have a substituent, or a substituent. An aromatic hydrocarbon group which may have a substituent, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, an amino group, a dialkylamino group which may have a substituent Or an optionally substituted diarylamino group, R ₁₃ and R ₁₄ , R ₁₄ and R ₁₅ , R ₁₆ and R ₁₇ , R ₁₇ and R ₁₈ are bonded to each other to form an aromatic ring; It may be formed. However, any one or more of R _{101 to} R ₁₀₅ is a saturated or unsaturated aliphatic hydrocarbon or aromatic hydrocarbon having at least one acryloyloxy group or methacryloyloxy group. ]   The electrophotographic photosensitive member according to claim 1 or 2, wherein the carbazole compound having a radical polymerizable functional group represented by the general formula (2) has one polymerizable functional group.   4. The mass ratio of the carbazole compound having no polymerizable functional group to the carbazole compound having the polymerizable functional group is 0.2 or more and 2.0 or less. 5. Electrophotographic photoreceptor.   The electrophotographic photosensitive member according to claim 1, wherein the surface layer contains inorganic fine particles in a proportion of 5 vol% or more and 40 vol% or less.   The electrophotographic photosensitive member according to claim 5, wherein the inorganic fine particles include at least one selected from aluminum oxide, titanium oxide, silicon oxide, and tin oxide.   The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer includes a charge generation layer and a charge transport layer. A charging step for charging the electrophotographic photosensitive member;
A latent image forming step of forming an electrostatic latent image on the surface of the electrophotographic photosensitive member charged by the charging step;
A developing step of forming a toner image by attaching toner to an image portion of the electrostatic latent image formed by the latent image forming step;
A transfer step of transferring the toner image formed by the development step to a transfer target;
A cleaning step for removing toner remaining on the surface of the electrophotographic photosensitive member after the transfer step,
The image forming method according to claim 1, wherein the electrophotographic photoreceptor is the electrophotographic photoreceptor according to claim 1. An electrophotographic photoreceptor according to any one of claims 1 to 7,
Charging means for charging the electrophotographic photosensitive member, latent image forming means for forming an electrostatic latent image on the surface of the electrophotographic photosensitive member charged by the charging means, and electrostatic latent image formed by the latent image forming means One or more means selected from a developing means for forming a toner image by attaching toner to the image portion of the toner, and a cleaning means for removing the toner remaining on the surface of the electrophotographic photosensitive member after the toner image is transferred And a process cartridge for an image forming apparatus that is integrated with
An image forming apparatus, wherein the process cartridge for the image forming apparatus is detachable. An electrophotographic photoreceptor according to any one of claims 1 to 7,
Charging means for charging the electrophotographic photosensitive member, latent image forming means for forming an electrostatic latent image on the surface of the electrophotographic photosensitive member charged by the charging means, and electrostatic latent image formed by the latent image forming means One or more means selected from a developing means for forming a toner image by attaching toner to the image portion of the toner, and a cleaning means for removing the toner remaining on the surface of the electrophotographic photosensitive member after the toner image is transferred And a process cartridge for the image forming apparatus, wherein the process cartridge is detachable from the main body of the image forming apparatus.

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