JP5929201B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an electrophotographic photosensitive member used for a copying machine, a laser printer, a facsimile, and the like, an image forming apparatus using the electrophotographic photosensitive member, and a process cartridge.

  2. Description of the Related Art In recent years, image forming apparatuses such as electrophotographic laser printers and digital copying machines have been widely spread due to improved image quality and stability. The electrophotographic photosensitive member used in these image forming apparatuses has a function of forming an electrostatic latent image on the surface by charging and exposure, and forming a visible image by developing the electrostatic latent image.

Electrophotographic photoreceptors are roughly classified into inorganic photoreceptors and organic photoreceptors, but organic photoreceptors (OPC) are widely used due to cost, productivity, freedom of material selection, and the impact on the global environment. It is popular. The organic photoreceptor is mainly composed of a photosensitive layer containing a photosensitive material, and has a single layer structure having a charge generation function and a charge transport function in one layer, a charge generation layer having a charge generation function, and a charge. It is roughly classified into a photosensitive layer having a laminated structure which is functionally separated into a charge transport layer having a transport function.
The mechanism of formation of an electrostatic latent image in an organic photoreceptor having a photosensitive layer having the above-described laminated structure is such that when a uniformly charged organic photoreceptor is irradiated with light, the light passes through the charge transport layer and the charge in the charge generation layer. It is absorbed by the generated substance and generates a charge (charge pair). One of them is injected into the charge transport layer at the interface between the charge generation layer and the charge transport layer, further moves through the charge transport layer by an electric field, reaches the surface of the organic photoreceptor, and neutralizes the surface charge given by charging Thus, an electrostatic latent image is formed. An organic photoreceptor having a laminated structure photosensitive layer is advantageous in terms of stability of electrostatic characteristics and durability, and is currently the mainstream in electrophotographic photoreceptors.

  In recent years, image forming apparatuses using organic photoreceptors are rapidly becoming full-color and speeding up, and accordingly, demand is diversified from the general office field to the SOHO field or the light printing field. In particular, in the light printing field, the printing volume is remarkably increased and the demand for stability of image quality is increased. Therefore, further enhancement of durability and stabilization of the organic photoreceptor are indispensable.

In order to increase the durability of the organic photoreceptor, 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 surface layer of the photoreceptor. For example, a method of improving the wear resistance and scratch resistance of the surface layer by using a thermosetting resin as a binder for the surface layer of the organic photoreceptor has been proposed (see Patent Documents 1 to 3).
In addition, it has been proposed to improve wear resistance and scratch resistance by using a polysiloxane resin having a crosslinked structure as a charge transport material (see Patent Documents 4 to 6).
In order to improve wear resistance and scratch resistance, a method using a monomer having a carbon-carbon double bond, a charge transporting material having a carbon-carbon double bond, and a binder resin has been proposed (patent). References 7 and 8).
In addition, in order to improve the mechanical durability of the photoreceptor, it has been proposed that the surface layer contains a filler (see Patent Documents 9 to 11).

In the image forming apparatus used in the light printing field, the problem of the exposure part potential fluctuation is that the printing is started and one job is finished and the printing is finished rather than the exposure part potential fluctuation when printing is performed for a relatively long time. As a problem, the fluctuation in the potential of the exposed portion when the process is resumed is larger. Hereinafter, the former is referred to as “daily fluctuation” of the exposure part potential, and the latter is referred to as “intra-job fluctuation” of the exposure part potential.
In the case of “daily fluctuation” of the exposure part potential, the effect is not noticeable, and the potential can be corrected in the image forming apparatus. "Is large, the influence is conspicuous, and if the potential fluctuates by several tens or several sheets in the job, it becomes difficult to correct the potential in the image forming apparatus, which is a serious problem.

  In the light printing field, there is a demand for printing a large amount of the same image pattern in one job. In this case, if the exposure portion potential varies greatly within the job, the image density changes and image quality consistency decreases. If it is a character-based image pattern, it will not stand out so much, but if it is an image-based and full-color image pattern, not only the image density but also the color will change, leading to a very serious problem. That is, it is required to reduce the exposed portion potential of the photosensitive member, and to suppress the exposed portion potential fluctuation in long-term repetitive printing, not only the daily fluctuation but also the intra-job fluctuation. In the photoconductor provided with a surface layer that dramatically improves the mechanical durability of the photoconductor, the mechanical protection function is given priority, and for extremely long-term repeated use as required in the light printing field, Actually, this is not sufficient to satisfy the demand for reducing the variation in the job potential of the exposed portion.

  In recent years, toners used for image formation in response to the demand for higher image quality are increasingly having a small particle size. In an image forming apparatus using a toner having a small particle diameter, the rate at which untransferred residual toner passes through the cleaning blade increases. In particular, when the dimensional accuracy and assembly accuracy of the cleaning blade are not sufficient, or when the cleaning blade partially oscillates, toner slips through more and prevents high-quality image formation. For this reason, in order to further extend the life of the photosensitive member and maintain high image quality over a long period of time, it is necessary to reduce deterioration of the member due to friction and improve cleaning properties.

As a method for reducing the friction between the photosensitive member and the cleaning blade, for example, a lubricating substance is supplied to the surface of the photosensitive member, and the supplied lubricating substance is uniformly applied by a cleaning blade or the like to lubricate the photosensitive member surface. A method for forming a film of a substance has been proposed (see Patent Document 12).
However, in the case where a lubricating substance is used, if the amount of the lubricating substance applied is too small, there may be a case where a sufficient effect cannot be exerted with respect to wear and scratches on the photoreceptor and deterioration of the cleaning blade. On the other hand, if an excessive amount of lubricating material is applied, excess lubricating material accumulates on the photoreceptor and image flow (image blur) occurs, or excess lubricating material mixes into the developer to improve the performance of the developer. In order to reduce this, it is necessary to control the application amount of the lubricating substance. Further, since the lubricating substance applied to the surface of the photoreceptor is removed by the cleaning blade, it is necessary to continue applying the lubricating substance during the image forming process. Therefore, the lubricating substance becomes a consumable material. The amount of the lubricating substance that can be mounted on the lubricating substance application means of the image forming apparatus is limited in space and can only be mounted in a certain amount, so if the consumption of the lubricating substance is large, the life of the image forming apparatus is short. There is a problem that an operation for re-mounting a lubricating substance occurs and the downtime of the image forming apparatus is caused, and the image forming productivity of the image forming apparatus is impaired.

  As described above, in order to realize a highly durable and high-quality image forming apparatus, further improvement in mechanical durability of the electrophotographic photosensitive member, stability of the exposure part potential, and “intra-job fluctuation of the exposure part potential” If the image forming apparatus has a lubricating substance applying means, an improvement in the consumption life of the lubricating substance is required.

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, the present invention suppresses not only the daily fluctuation of the exposure part potential but also the fluctuation of the exposure part potential within the job, and can achieve both reduction in the amount of the lubricant used and wear resistance of the photosensitive member over a long period of time. An object of the present invention is to provide an electrophotographic photosensitive member capable of stably obtaining a high-quality image.

  In order to solve the above problems, the present inventors have provided an image forming apparatus having an electrophotographic photosensitive member containing a filler on the surface layer of the photosensitive layer and a lubricating substance applying means for applying a lubricating substance to the surface of the electrophotographic photosensitive member. As a result of intensive studies to achieve high durability and high image quality, the surface layer of the photosensitive layer contains a filler and an aromatic hydrocarbon, and the extraction temperature is 230 ° C. for 15 minutes. When the content of the aromatic hydrocarbon in the photosensitive layer measured by thermal extraction gas chromatograph mass spectrometry under extraction conditions at 190 ° C. for 15 minutes is 100 mass ppm to 2,500 mass ppm, Can reduce daily fluctuations and in-job fluctuations of the exposed area potential, improve the affinity between the electrophotographic photosensitive member surface and the lubricating material, and reduce consumption of the lubricating material and wear of the photosensitive member. It was found that kill.

The present invention is based on the above findings by the present inventors, and means for solving the above problems are as follows. That is,
The electrophotographic photoreceptor of the present invention comprises a support and at least a photosensitive layer on the support,
The surface layer of the photosensitive layer contains at least a filler and an aromatic hydrocarbon, and is measured by thermal extraction gas chromatograph mass spectrometry under extraction conditions of an extraction temperature of 230 ° C. for 15 minutes and a cryotrap temperature of −190 ° C. for 15 minutes. The content of the aromatic hydrocarbon in the photosensitive layer is 100 mass ppm to 2,500 mass ppm.

The electrophotographic photosensitive member of the present invention includes (1) optical characteristics such as a wide light absorption wavelength range and a large amount of absorption, (2) electrical characteristics such as high sensitivity and stable charging characteristics, (3 Organic photoreceptors (OPC) are preferably used from the viewpoints of a wide selection range of materials, (4) ease of production, (5) low cost, and (6) non-toxicity.
When the surface layer of the photosensitive layer of the electrophotographic photosensitive member contains at least one aromatic hydrocarbon selected from xylene, toluene, and benzene, the daily fluctuation of the exposed area potential and the exposure area potential within the job The details of the reason why the fluctuation can be reduced and the reason why the affinity between the photoreceptor surface and the lubricating substance is improved are not clear at the present time, but the following factors are presumed.
(1) About the daily fluctuation of the exposed area potential and the intra-job fluctuation of the exposed area potential, the surface layer of the photosensitive layer contains at least one aromatic hydrocarbon selected from xylene, toluene, and benzene. In addition, the penetration of the oxidizing gas generated from the charging means into the surface layer and the deterioration of the charge transport material due to repeated energization can be suppressed.
(2) For improving the affinity between the lubricating material and the surface of the electrophotographic photoreceptor, at least one aromatic hydrocarbon selected from xylene, toluene and benzene contained in the surface layer of the photosensitive layer, and a fatty acid metal salt Affinity with a lubricating material of the system is good, and a sufficient effect can be exhibited even when the content of the aromatic hydrocarbon in the photosensitive layer is a trace amount of 100 ppm to 2,500 ppm by mass.
Accordingly, by using the electrophotographic photosensitive member of the present invention, an image forming apparatus and a process cartridge that can achieve both high durability and high image quality and can stably obtain high-quality images even after repeated use are provided. can do.

  According to the present invention, the conventional problems can be solved and the object can be achieved, and not only the daily fluctuation of the exposure part potential but also the intra-job fluctuation of the exposure part potential is suppressed, and the usage amount of the lubricating substance is reduced. It is possible to provide an electrophotographic photosensitive member that can achieve both a reduction in image quality and the wear resistance of the photosensitive member, and can stably obtain a high-quality image over a long period of time.

FIG. 1 is a schematic view showing an example of the electrophotographic photosensitive member of the present invention. FIG. 2 is a schematic view showing another example of the electrophotographic photosensitive member of the present invention. FIG. 3 is a schematic view showing another example of the electrophotographic photosensitive member of the present invention. FIG. 4 is a schematic view showing another example of the electrophotographic photosensitive member of the present invention. FIG. 5 is a schematic view showing another example of the electrophotographic photosensitive member of the present invention. 6 is an X-ray diffraction spectrum diagram of the titanyl phthalocyanine powder synthesized in Synthesis Example 2. FIG. FIG. 7 is a schematic view showing an example of the image forming apparatus of the present invention. FIG. 8 is a schematic view showing an example of a lubricating substance applying unit in the image forming apparatus of the present invention. FIG. 9 is a schematic view showing another example of the image forming apparatus of the present invention. FIG. 10 is a schematic view showing another example of the image forming apparatus of the present invention. FIG. 11 is a schematic view showing another example of the image forming apparatus of the present invention. FIG. 12 is a partially enlarged view of FIG. FIG. 13 is a schematic view showing an example of the process cartridge of the present invention. FIG. 14 is a diagram showing a method of measuring the friction coefficient μ of the photosensitive member by the Euler belt method in the embodiment.

(Electrophotographic photoreceptor)
The electrophotographic photoreceptor of the present invention has a support and at least a photosensitive layer on the support, and further has other layers as necessary.

<Photosensitive layer>
The photosensitive layer is not particularly limited as long as it has a surface layer, and can be appropriately selected according to the purpose. However, in the case of a single-layered photosensitive layer, the surface layer is the photosensitive layer or the photosensitive layer. The surface layer formed above corresponds and is preferably a surface layer. In a photosensitive layer having a multilayer structure having a charge generation layer and a charge transport layer in this order, the surface layer corresponds to a charge transport layer or a surface layer formed on the charge transport layer, and is preferably a surface layer. . Note that the charge generation layer and the charge transport layer may be laminated in reverse.

<< Surface layer of photosensitive layer >>
The surface layer of the photosensitive layer contains at least a filler and an aromatic hydrocarbon, and further contains other components as necessary.

-Aromatic hydrocarbons-
The aromatic hydrocarbon is preferably at least one selected from xylene, toluene, and benzene. The xylene, toluene, and benzene have a solubility parameter (SP value) of 8.8 to 9.2, and a fatty acid metal salt-based lubricating substance (for example, stearic acid) in the lubricating substance coating unit of the image forming apparatus. The SP value of zinc has a good affinity with a literature value of about 9.2 (JP-A-01-101400, etc.).
Thermal extraction gas chromatograph mass spectrometry with extraction conditions of 15 minutes at an extraction temperature of 230 ° C. and 15 minutes at a cryotrap temperature of −190 ° C., that is, the content of the aromatic hydrocarbon in the photosensitive layer measured under the following conditions: It is 100 mass ppm-2,500 mass ppm, and 120 mass ppm-1,500 mass ppm are preferable.
Here, the cryotrap temperature means that the components generated from the sample by heating are once cooled to a low temperature (cryotrap) before introducing the separation column, and the components are concentrated in a narrow bandwidth and then rapidly desorbed. The trap temperature for improving the component separation ability by the separation column is meant. In order to accurately quantify the content of low-molecular-weight aromatic hydrocarbons having a low boiling point as in the present invention, the use of a cryotrap is a suitable analysis form.
A part (5 mg to 10 mg) of the photosensitive layer is cut out, and the content (mass) of at least one aromatic hydrocarbon selected from xylene, toluene, and benzene by heat extraction gas chromatography mass spectrometry under the following conditions: ppm) can be measured.
〔Measurement condition〕
GC-MS device: QP-2010 manufactured by Shimadzu Corporation
Data analysis software: GCMS solution (NIST 20 MASS SPECTRAL LIB.) Manufactured by Shimadzu Corporation
・ Heat extraction conditions
Extraction temperature x time: 230 ° C x 15 minutes
Cryotrap temperature: -190 ° C (liquid nitrogen) x 15 minutes-Heating device: Py-2020D manufactured by Frontier Laboratories
Column: Ultrala ALLOY-5 L = 30 m, ID = 0.25 mm, File = 0.25 μm
Column heating: 50 ° C. (holding 1 minute) to 5 ° C./min to 80 ° C. to 40 ° C./min to 280 ° C. (holding 5 minutes)
Carrier gas pressure: 53.6 kPa constant Column flow rate: 1.0 mL / min
・ Ionization method: EI method (70 eV)
Injection mode: Split (1: 100)
・ Measurement mode: Ion selection (Selected Ion Monitoring; SIM method)

When the content of the aromatic hydrocarbon is less than 100 ppm by mass, the daily fluctuation and the intra-job fluctuation of the exposed portion potential caused by the surface layer of the photosensitive layer are increased, and the uniformity of the image density is deteriorated. Further, when used in an image forming apparatus having a lubricating substance applying means, the affinity between the surface layer of the photosensitive layer and the lubricating substance is reduced, so that the consumption of the lubricating substance is increased. That is, the life of the lubricating material is shortened, the life of the image forming apparatus is shortened, or the work for re-loading the lubricating material is generated, resulting in downtime of the image forming apparatus. The productivity of image formation is impaired.
On the other hand, if the content of the aromatic hydrocarbon exceeds 2,500 mass ppm, the surface of the photosensitive layer is reduced in hardness, so that the surface of the electrophotographic photosensitive member is easily scratched and image defects due to scratches occur. It becomes easy. In addition, the variation in the exposure portion potential within the job is increased due to the side effect of the aromatic hydrocarbon. Further, when used in an image forming apparatus having a lubricating substance applying means, the affinity between the surface layer of the photosensitive layer and the lubricating substance becomes too large, and excess lubricating substance is accumulated on the electrophotographic photosensitive member. May cause image flow.

  In order to realize the content of the aromatic hydrocarbon in the photosensitive layer (surface layer of the photosensitive layer), as described in the method for producing an electrophotographic photoreceptor described later, xylene and toluene are prepared during the preparation of the surface layer coating solution. And a predetermined amount of at least one aromatic hydrocarbon selected from benzene is added, the prepared surface layer coating solution is applied, and a drying temperature of 100 ° C. to 150 ° C. and a drying time of 10 minutes to 30 in the subsequent drying step. It is necessary to heat for a minute. That is, the content of at least one aromatic hydrocarbon selected from xylene, toluene, and benzene in the photosensitive layer is determined by adding the amount of aromatic hydrocarbon to the surface layer coating solution and the surface layer coating solution. It can be controlled by the drying temperature and drying time in the drying step after coating.

-Filler-
The surface layer of the photosensitive layer plays a role of protecting the outermost surface of the electrophotographic photosensitive member. That is, by including a filler in the surface layer, the wear resistance is remarkably improved and the life of the electrophotographic photosensitive member is extended. In addition, by adding a filler to the surface layer, fine irregularities are formed on the surface, the applicability of a lubricating substance made of a fatty acid metal salt such as zinc stearate and calcium stearate is improved, and cleaning properties and transfer properties are increased. Can be improved.

There is no restriction | limiting in particular as said filler, According to the objective, it can select suitably, For example, an organic filler, an inorganic filler, etc. are mentioned.
Examples of the organic filler include fluororesin powder such as polytetrafluoroethylene, silicone resin powder, and a-carbon powder.
Examples of the inorganic filler include metal powders such as copper, tin, aluminum, and indium; metal oxides such as aluminum oxide (alumina), silicon oxide, tin oxide, zinc oxide, titanium oxide, indium oxide, antimony oxide, and bismuth oxide. Thing; Potassium titanate etc. are mentioned.
These fillers may be used alone or in combination of two or more.
Among these, inorganic fillers are preferable from the viewpoint of the hardness of the filler, metal oxides are more preferable from the viewpoint of small side effects on the electrostatic characteristics of the electrophotographic photosensitive member, and silicon oxide, aluminum oxide, and titanium oxide are particularly preferable. Fine particles such as colloidal silica and colloidal alumina can also be used effectively.
The average primary particle size of the filler is preferably 0.01 μm to 0.5 μm from the viewpoint of light transmittance and wear resistance of the surface layer of the photosensitive layer. If the average primary particle size of the filler is less than 0.01 μm, it may cause a decrease in abrasion resistance and a decrease in dispersibility. If it exceeds 0.5 μm, it is in the coating liquid (dispersion). In some cases, sedimentation of the filler is promoted and toner filming on the surface of the photoreceptor in the image forming apparatus may occur.

  The filler is preferably surface-treated with a surface treatment agent from the viewpoint of dispersibility. Decreasing the dispersibility of the filler not only causes adverse effects on the electrostatic properties such as an increase in residual potential, but also decreases the transparency of the coating film, the occurrence of coating film defects, and the wear resistance. As a result, there is a possibility that it will develop into a big problem that prevents high durability or high image quality.

There is no restriction | limiting in particular as said surface treating agent, Although it can select suitably according to the objective, The surface treating agent which can maintain the insulation of a filler is preferable.
Examples of the surface treatment agent include titanate coupling agents, aluminum coupling agents, zircoaluminate coupling agents, higher fatty acids, or mixed treatment products of these with silane coupling agents; Al ₂ O ₃ , Examples thereof include TiO ₂ , ZrO ₂ , silicone, aluminum stearate, or a mixed processed product thereof.
The treatment with the silane coupling agent is strongly influenced by image blur, but the influence may be suppressed by performing a mixing treatment of the surface treatment agent and the silane coupling agent.
There is no restriction | limiting in particular as a quantity of the said surface treating agent, Although it changes with the average primary particle diameters of the filler to be used, and it can select suitably according to the objective, 3 mass%-30 mass% are with respect to the said filler. Preferably, 5% by mass to 20% by mass is more preferable. When the content is less than 3% by mass, the filler dispersion effect may not be obtained. When the content exceeds 30% by mass, the residual potential may be significantly increased.

  The larger the filler content in the surface layer of the photosensitive layer is, the better the surface layer is because the wear resistance of the surface layer is higher, but if it is too much, the residual potential increases and the writing light transmittance of the surface layer decreases. Side effects may occur. Therefore, the filler content in the surface layer of the photosensitive layer is preferably 5% by mass or more and 50% by mass or less, and more preferably 5% by mass or more and 30% by mass or less with respect to the total solid content of the surface layer.

  The surface layer of the photosensitive layer contains the aromatic hydrocarbon and the filler, and further includes (1) an aspect containing a binder resin and a compound having a charge transporting structure, and (2) no charge transporting property. The aspect containing the hardened | cured material of the radically polymerizable monomer more than functional and the radically polymerizable compound which has a charge transportable structure is mentioned.

-Aspect (1) containing the binder resin and a compound having a charge transporting structure-
--Binder resin--
There is no restriction | limiting in particular as said binder resin, According to the objective, it can select suitably, For example, polycarbonate resin, polyester resin, methacryl resin, acrylic resin, polyethylene resin, polyvinyl chloride resin, polyvinyl acetate resin, polystyrene Examples include resins, phenol resins, epoxy resins, polyurethane resins, polyvinylidene chloride resins, alkyd resins, silicone resins, polyvinyl carbazole resins, polyvinyl butyral resins, polyvinyl formal resins, polyacrylate resins, polyacrylamide resins, and phenoxy resins. These may be used individually by 1 type and may use 2 or more types together.

--Compound having a charge transporting structure--
Examples of the compound having a charge transport structure include a low molecular charge transport material and a polymer charge transport material.
There is no restriction | limiting in particular as said low molecular charge transport material, According to the objective, it can select suitably, For example, an electron transport material, a hole transport material, etc. are mentioned.

  The electron transport material is not particularly limited and may be appropriately selected depending on the intended purpose. For example, chloroanil, bromilyl, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone 2,4,5,7-tetranitro-9-fluorenone, 2,4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1 , 2-b] thiophen-4-one, 1,3,7-trinitrodibenzothiophene-5,5-dioxide, diphenoquinone derivatives and the like. These may be used individually by 1 type and may use 2 or more types together.

The hole transport material is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include oxazole derivatives, oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, and triarylamine derivatives. , Stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triarylmethane derivatives, 9-styrylanthracene derivatives, pyrazoline derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, etc. Derivatives, enamine derivatives and the like. These may be used individually by 1 type and may use 2 or more types together.
Examples of the polymer charge transport material include polymer charge transport materials exemplified in the charge transport layer described later.

-(2) A mode of containing a cured product of a composition containing a radically polymerizable monomer having three or more functional groups having no charge transporting property and a radically polymerizable compound having a charge transporting structure-
A three-dimensional network structure formed using a tri- or higher functional radical polymerizable monomer having no charge transporting property and a radical polymerizable compound having a charge transporting structure has a very high degree of crosslinking. A superior surface layer and higher wear resistance is achieved. In particular, it is preferable to add a filler to the crosslinkable resin, since the wear resistance becomes very high, the electrophotographic photosensitive member can be used for a long time, and the effects of the present invention are further remarkably exhibited.

  Examples of the trifunctional or higher functional radical polymerizable monomer having no charge transporting property include hole transporting structures such as triarylamine, hydrazone, pyrazoline and carbazole; for example, condensed polycyclic quinone, diphenoquinone, cyano group, nitro group A monomer having no electron transport structure such as an electron-withdrawing aromatic ring having a group and having three or more radically polymerizable functional groups. The radical polymerizable functional group may be any group as long as it has a carbon-carbon double bond and is capable of radical polymerization.

Examples of these radical polymerizable functional groups include 1-substituted ethylene functional groups and 1,1-substituted ethylene functional groups shown below.
(1) As 1-substituted ethylene functional group, the functional group represented by the following general formula (d) is mentioned, for example.
However, in the general formula (d), X ₁ represents an arylene group which may have a substituent, an alkenylene group which may have a substituent, a —CO— group, a —COO— group, a —CON (R ₁ ) -group [R ₁ represents hydrogen, an alkyl group, an aralkyl group, or an aryl group. Or -S- group.

Examples of the arylene group of the general formula (d) include a phenylene group and a naphthylene group which may have a substituent. Examples of the alkenylene group include an ethenylene group, a propenylene group, and a butenylene group.
Examples of the alkyl group include a methyl group and an ethyl group. Examples of the aralkyl group include a benzyl group, a naphthylmethyl group, and a phenethyl group. Examples of the aryl group include a phenyl group and a naphthyl group.
Examples of the functional group represented by the general formula (d) include a vinyl group, a styryl group, a 2-methyl-1,3-butadienyl group, a vinylcarbonyl group, an acryloyloxy group, an acryloylamide group, and a vinylthioether group. Is mentioned.

(2) Examples of the 1,1-substituted ethylene functional group include functional groups represented by the following general formula (e).
However, in the general formula (e), Y represents an alkyl group which may have a substituent, an aralkyl group which may have a substituent, an aryl group which may have a substituent, a halogen atom, cyano. Group, nitro group, alkoxy group, —COOR ₂ group [R ₂ may have a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or a substituent. An aryl group, or CONR ₃ R ₄ (R ₃ and R ₄ may have a hydrogen atom, an alkyl group that may have a substituent, an aralkyl group that may have a substituent, or a substituent. Represents an aryl group and may be the same or different from each other. X ₂ represents the same substituent, single bond, and alkylene group as X _{1 in the} general formula (d). However, at least one of Y and X ₂ is an oxycarbonyl group, a cyano group, an alkenylene group, or an aromatic ring.

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

The specific trivalent or higher functional radical polymerizable monomer having no charge transport structure is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include trimethylolpropane triacrylate (TMPTA), Methylolpropane trimethacrylate, EO-modified trimethylolpropane triacrylate, PO-modified trimethylolpropane triacrylate, caprolactone-modified trimethylolpropane triacrylate, HPA-modified trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate (PETTA), Glycerol triacrylate, ECH-modified glycerol triacrylate, EO-modified glycerol triacrylate, PO-modified glycerol triacrylate Chryrate, tris (acryloxyethyl) isocyanurate, dipentaerythritol hexaacrylate (DPHA), caprolactone-modified dipentaerythritol hexaacrylate, dipentaerythritol hydroxypentaacrylate, alkyl-modified dipentaerythritol pentaacrylate, alkyl-modified dipentaerythritol tetraacrylate , Alkyl-modified dipentaerythritol triacrylate, dimethylolpropane tetraacrylate (DTMPTA), pentaerythritol ethoxytetraacrylate, EO-modified phosphate triacrylate, 2,2,5,5-tetrahydroxymethylcyclopentanone tetraacrylate, etc. It is done. These may be used individually by 1 type and may use 2 or more types together.
In the above, EO modification refers to ethyleneoxy modification, and PO modification refers to propyleneoxy modification.

The trifunctional or higher functional radical polymerizable monomer having no charge transporting structure has a ratio of molecular weight to the number of functional groups in the monomer (molecular weight / number of functional groups) in order to form a dense crosslink in the surface layer. 250 or less is preferable. When the ratio is greater than 250, the crosslinked surface layer is soft and wear resistance is somewhat lowered. Therefore, among the monomers exemplified above, monomers having a modifying group such as HPA, EO, PO are extremely long modifying groups. It is not preferable to use a compound having a singly.
The component ratio of the trifunctional or higher functional radical polymerizable monomer not having the charge transport structure is preferably 20% by mass to 80% by mass with respect to the total amount of the surface layer, and wear resistance required by the process used. However, it is not possible to say unconditionally because the electric characteristics are different. When the proportion of the monomer component is less than 20% by mass, the surface layer has a small three-dimensional cross-linking density, and a dramatic improvement in wear resistance cannot be achieved as compared with the case of using a conventional thermoplastic binder resin. If it exceeds 80% by mass, the content of the charge transporting compound may be reduced, and the electrical characteristics may be deteriorated.

Examples of the radical polymerizable compound having a charge transporting structure include hole transporting structures such as triarylamine, hydrazone, pyrazoline, and carbazole; for example, electrons having condensed polycyclic quinone, diphenoquinone, cyano group, and nitro group It refers to a compound having an electron transport structure such as an attractive aromatic ring and having a radical polymerizable functional group. Examples of the radical polymerizable functional group include those shown for the radical polymerizable monomer, and an acryloyloxy group and a methacryloyloxy group are particularly preferable.
The number of radically polymerizable functional groups of the radically polymerizable compound having a charge transporting structure is not particularly limited as long as it is 1 or more, and can be appropriately selected according to the purpose. The effect of those having a triarylamine structure is high, especially when a radically polymerizable compound having a monofunctional charge transporting structure having a triarylamine structure represented by the following general formula (I) or (II) is used , Electrical characteristics such as sensitivity and residual potential are well maintained.
However, in the general formula (I) or (II), R ₁₀ has a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or a substituent. Aryl group, cyano group, nitro group, alkoxy group, —COOR ₁₁ (R ₁₁ may be a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or a substituent An aryl group which may have a group), a carbonyl halide group or CONR ₁₂ R ₁₃ (R ₁₂ and R ₁₃ are a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, a substituent; Represents an aralkyl group which may have a substituent, or an aryl group which may have a substituent, which may be the same or different from each other. Ar ₁ and Ar ₂ represent an arylene group which may have a substituent, and may be the same or different. Ar ₃ and Ar ₄ represent an aryl group which may have a substituent, and may be the same or different. X ₁₀ represents a single bond, an alkylene group which may have a substituent, a cycloalkylene group which may have a substituent, an alkylene ether group which may have a substituent, an oxygen atom, a sulfur atom, or vinylene. Represents a group. Z represents an alkylene group which may have a substituent, an alkylene ether group which may have a substituent, or an alkyleneoxycarbonyl group. m and n represent the integer of 0-3.

Specific examples of each group indicated by general symbols in the general formula (I) or (II) are shown below.
In the general formula (I) or (II), examples of the alkyl group represented by R ₁₀ include a methyl group, an ethyl group, a propyl group, and a butyl group. Examples of the aryl group include a phenyl group and a naphthyl group. Examples of the aralkyl group include a benzyl group, a phenethyl group, and a naphthylmethyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, and a propoxy group. These include alkyl groups such as halogen atoms, nitro groups, cyano groups, methyl groups, and ethyl groups; alkoxy groups such as methoxy groups and ethoxy groups; aryloxy groups such as phenoxy groups; aryl groups such as phenyl groups and naphthyl groups; It may be substituted with an aralkyl group such as a benzyl group or a phenethyl group.
Of the substituents represented by R ₁₀ , a hydrogen atom and a methyl group are particularly preferable.

Ar ₃ and Ar ₄ are aryl groups that may have a substituent, and examples of the aryl group include condensed polycyclic hydrocarbon groups, non-condensed cyclic hydrocarbon groups, and heterocyclic groups.
The condensed polycyclic hydrocarbon group preferably has 18 or less carbon atoms forming a ring, for example, a pentanyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptaenyl group, a biphenylenyl group, an as-indacenyl group. , S-indacenyl group, fluorenyl group, acenaphthylenyl group, preadenyl group, acenaphthenyl group, phenalenyl group, phenanthryl group, anthryl group, fluoranthenyl group, acephenanthrenyl group, aceanthrylenyl group, triphenylyl group, pyrenyl group , A chrycenyl group, a naphthacenyl group, and the like.
Examples of the non-condensed cyclic hydrocarbon group include monovalent groups of monocyclic hydrocarbon compounds such as benzene, diphenyl ether, polyethylene diphenyl ether, diphenyl thioether, diphenyl sulfone; biphenyl, polyphenyl, diphenylalkane, diphenylalkene, diphenyl Monovalent groups of non-condensed polycyclic hydrocarbon compounds such as alkyne, triphenylmethane, distyrylbenzene, 1,1-diphenylcycloalkane, polyphenylalkane and polyphenylalkene; ring assembly such as 9,9-diphenylfluorene And monovalent groups of hydrocarbon compounds.
Examples of the heterocyclic group include monovalent groups such as carbazole, dibenzofuran, dibenzothiophene, oxadiazole, and thiadiazole.

The aryl group represented by Ar ₃ and Ar ₄ may have a substituent as shown below, for example.
[1] Halogen atom, cyano group, nitro group and the like can be mentioned.
[2] Examples include alkyl groups. The alkyl group is preferably a linear or branched alkyl group having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, and still more preferably 1 to 4 carbon atoms. Having a phenyl group substituted by an atom, a hydroxyl group, a cyano group, an alkoxy group having 1 to 4 carbon atoms, a phenyl group or a halogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms Also good.
Examples of the alkyl group include methyl group, ethyl group, n-butyl group, i-propyl group, t-butyl group, s-butyl group, n-propyl group, trifluoromethyl group, 2-hydroxyethyl group, Examples include 2-ethoxyethyl group, 2-cyanoethyl group, 2-methoxyethyl group, benzyl group, 4-chlorobenzyl group, 4-methylbenzyl group, 4-phenylbenzyl group and the like.
[3] An alkoxy group (—OR ₁₄ ) may be mentioned. However, R ₁₄ is the same as the alkyl group shown in the above [2].
Examples of the alkoxy group include methoxy group, ethoxy group, n-propoxy group, i-propoxy group, t-butoxy group, n-butoxy group, s-butoxy group, i-butoxy group, 2-hydroxyethoxy group, Examples include benzyloxy group and trifluoromethoxy group.
[4] Aryloxy group is exemplified. Examples of the aryl group of the aryloxy group include a phenyl group and a naphthyl group, and these include a C 1-4 alkoxy group, a C 1-4 alkyl group, or a halogen atom as a substituent. You may contain.
Examples of the aryloxy group include a phenoxy group, a 1-naphthyloxy group, a 2-naphthyloxy group, a 4-methoxyphenoxy group, and a 4-methylphenoxy group.
[5] An alkyl mercapto group or an aryl mercapto group can be mentioned. Examples of the alkyl mercapto group include a methylthio group and an ethylthio group. Examples of the aryl mercapto group include a phenylthio group and a p-methylphenylthio group.
[6] Examples include groups represented by the following general formula (f).
In the general formula _{(f), R 15} and _{R 16} are each independently a hydrogen atom, an alkyl group, or aryl group shown by the formula _{[2], R 15} and _{R 16} together A ring may be formed.
Examples of the aryl group include a phenyl group, a biphenyl group, and a naphthyl group, which contain an alkoxy group having 1 to 4 carbon atoms, an alkyl group having 1 to 4 carbon atoms, or a halogen atom as a substituent. Also good.
Examples of the group represented by the general formula (f) include an amino group, a diethylamino group, an N-methyl-N-phenylamino group, an N, N-diphenylamino group, and an N, N-di (tolyl) amino group. , Dibenzylamino group, piperidino group, morpholino group, pyrrolidino group and the like.
[7] Examples include an alkylenedioxy group and an alkylenedithio group.
Examples of the alkylenedioxy group include a methylenedioxy group and an ethylenedioxy group. Examples of the alkylenedithio group include a methylenedithio group and an ethylenedithio group.
[8] A styryl group that may have a substituent, a β-phenylstyryl group that may have a substituent, a diphenylaminophenyl group, a ditolylaminophenyl group, and the like.

Examples of the arylene group represented by Ar ₁ and Ar ₂ include a divalent group derived from the aryl group represented by Ar ₃ and Ar ₄ .

X ₁₀ represents a single bond, an alkylene group that may have a substituent, a cycloalkylene group that may have a substituent, an alkylene ether group that may have a substituent, an oxygen atom, a sulfur atom, or vinylene. Represents a group.

Examples of the alkylene group that may have a substituent include linear or branched alkylene groups having 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms. These alkylene groups are further substituted with a fluorine atom, a hydroxyl group, a cyano group, an alkoxy group having 1 to 4 carbon atoms, a phenyl group or a halogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. It may have a phenyl group.
Examples of the alkylene group include methylene group, ethylene group, n-butylene group, i-propylene group, t-butylene group, s-butylene group, n-propylene group, trifluoromethylene group, 2-hydroxyethylene group, Examples include 2-ethoxyethylene group, 2-cyanoethylene group, 2-methoxyethylene group, benzylidene group, phenylethylene group, 4-chlorophenylethylene group, 4-methylphenylethylene group, 4-biphenylethylene group and the like.

Examples of the cycloalkylene group that may have a substituent include cyclic alkylene groups having 5 to 7 carbon atoms. The cyclic alkylene group may have a fluorine atom, a hydroxyl group, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms as a substituent.
Examples of the cycloalkylene group include a cyclohexylidene group, a cyclohexylene group, and a 3,3-dimethylcyclohexylidene group.

As the alkylene ether group which may have the substituent, a —CH ₂ CH ₂ O— group, a —CH ₂ CH ₂ CH ₂ O— group, a — (OCH ₂ CH ₂ ) _h —O— group, or — _(OCH 2 _CH 2 _{CH 2),} such as i -O- group. However, h and i in the said formula represent the integer of 1-4, respectively.
The alkylene group of the alkylene ether group may have a substituent such as a hydroxyl group, a methyl group, or an ethyl group.

The vinylene group in the X _10, the following general formula (g), and the like groups represented by (h).
However, in the general formulas (g) and (h), R ₁₇ is a hydrogen atom, an alkyl group (same as the alkyl group defined in [2] above), or an aryl group (represented by Ar ₃ or Ar ₄ above). The same as the aryl group to be formed. a represents 1 or 2, and b represents an integer of 1 to 3.

  Z represents an alkylene group which may have a substituent, an alkylene ether group which may have a substituent, or an alkyleneoxycarbonyl group.

Examples of the alkylene group which may have a substituent include the same alkylene groups as those described above for X.
Examples of the alkylene ether group which may have the substituent include the same alkylene ether groups as those described above for X.
Examples of the alkyleneoxycarbonyl group include a caprolactone-modified group.

More preferably, the radically polymerizable compound having a monofunctional charge transport structure is a compound represented by the following general formula (III).
However, in the said general formula (III), o, p, and q represent 0 or 1, respectively. Ra represents a hydrogen atom or a methyl group. Rb and Rc each represent a C 1-6 alkyl group as a substituent other than a hydrogen atom, and may be the same or different. s and t represent the integer of 0-3. Za represents a single bond, a methylene group, an ethylene group, or a divalent group represented by any of the following formulas (a), (b), and (c).
The compound represented by the general formula (III) is preferably a compound in which the substituents of Rb and Rc are a methyl group and an ethyl group.

The surface layer is free from cracks and has excellent electrical characteristics. The reason is that when the radically polymerizable compound having a monofunctional charge transport structure represented by the general formula (I) and the general formula (II), particularly the general formula (III) is used, carbon-carbon is used. In the polymer in which the double bond between the two is opened and polymerized, it does not become a terminal structure, but is incorporated into a chain polymer and crosslinked by polymerization with a trifunctional or higher radical polymerizable monomer. Existing in the main chain of the polymer and in the cross-linked chain between the main chain and the main chain (this cross-linked chain includes an intermolecular cross-linked chain between one polymer and another polymer, There is an intramolecular cross-linked chain in which a part of the main chain folded in the above state and another part derived from the polymerized monomer are cross-linked at a position away from the main chain. In other words, a triarylamine structure suspended from a chain portion regardless of whether a radically polymerizable compound having a monofunctional charge transport structure is present in the main chain or in a crosslinked chain. Has at least three aryl groups arranged radially from the nitrogen atom and is bulky, but is not directly bonded to the chain part and is suspended from the chain part via a carbonyl group or the like. Since these triarylamine structures can be arranged adjacent to each other in the polymer, the structural distortion in the molecule is small. When the surface layer of an electrophotographic photoreceptor is used, it is presumed that an intramolecular structure that is relatively free from interruption of the charge transport path can be adopted.
The radical polymerizable compound having a monofunctional charge transporting structure may be disclosed in, for example, Japanese Patent Application Laid-Open No. 2011-039158, but is not limited to these compounds. In addition, you may have multiple numbers of radically polymerizable functional groups.

  The radical polymerizable compound having the monofunctional charge transport structure is important for imparting the charge transport performance of the surface layer, and the content of the radical polymerizable compound having the monofunctional charge transport structure is: 20 mass%-80 mass% are preferable with respect to the said surface layer whole quantity, and 35 mass%-65 mass% are more preferable. When the content is less than 20% by mass, the charge transport performance of the surface layer cannot be sufficiently maintained, and deterioration of electrical characteristics such as a decrease in sensitivity and an increase in residual potential may appear due to repeated use. When it exceeds mass%, the content of the trifunctional or higher-functional radical polymerizable monomer having no charge transporting structure is lowered and the crosslink density is lowered, and high wear resistance is not exhibited. Although the electrical characteristics and abrasion resistance required differ depending on the process used, it cannot be said unconditionally, but the range of 35 mass% to 65 mass% is most preferable in consideration of the balance of both characteristics.

A surface layer formed by curing using a trifunctional or higher functional radical polymerizable monomer having no charge transporting structure and a radical polymerizable compound having a charge transporting structure is preferably used. In addition to functional monomers and radical polymerizable compounds, other monofunctional and bifunctional radical polymerizable monomers are provided for the purpose of imparting functions such as viscosity adjustment during coating, stress relaxation of the surface layer, lower surface energy, and reduction of friction coefficient. A functional monomer and a radical polymerizable oligomer can be used in combination.
There is no restriction | limiting in particular as these radically polymerizable monomers and oligomers, According to the objective, it can select suitably, A specific example is illustrated below.

  Examples of the monofunctional radical polymerizable monomer include 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, tetrahydrofurfuryl acrylate, 2-ethylhexyl carbitol acrylate, 3-methoxybutyl acrylate, and benzyl acrylate. Cyclohexyl acrylate, isoamyl acrylate, isobutyl acrylate, methoxytriethylene glycol acrylate, phenoxytetraethylene glycol acrylate, cetyl acrylate, isostearyl acrylate, stearyl acrylate, styrene monomer, and the like. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the bifunctional radically polymerizable monomer include 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1 , 6-hexanediol dimethacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, EO-modified bisphenol A diacrylate, EO-modified bisphenol F diacrylate, neopentyl glycol diacrylate, and the like. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the functional monomer include those substituted with fluorine atoms such as octafluoropentyl acrylate, 2-perfluorooctylethyl acrylate, 2-perfluorooctylethyl methacrylate, 2-perfluoroisononylethyl acrylate, and the like. No.-60503, JP-B-6-45770, acryloyl polydimethylsiloxane ethyl, methacryloyl polydimethylsiloxane ethyl, acryloyl polydimethylsiloxane propyl, acryloyl polydimethylsiloxane butyl, diacryloyl poly having 20 to 70 siloxane repeating units Examples thereof include vinyl monomers having a polysiloxane group such as dimethylsiloxane diethyl, acrylates and methacrylates. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the radical polymerizable oligomers include epoxy acrylate oligomers, urethane acrylate oligomers, and polyester acrylate oligomers. However, if a large amount of the monofunctional and bifunctional radically polymerizable monomers and radically polymerizable oligomers are contained, the three-dimensional cross-linking density of the surface layer is substantially reduced, resulting in a decrease in wear resistance. The content of the monomer or oligomer is preferably 50 parts by mass or less and more preferably 30 parts by mass or less with respect to 100 parts by mass of the tri- or higher functional radical polymerizable monomer.

  The surface layer preferably contains a cured product of a tri- or higher functional radical polymerizable monomer having no charge transporting structure and a radical polymerizable compound having a charge transporting structure. This curing reaction (crosslinking reaction) In order to make the process proceed efficiently, a polymerization initiator may be used as necessary to form a surface layer.

Examples of the polymerization initiator include a thermal polymerization initiator and a photopolymerization initiator.
Examples of the thermal polymerization initiator include 2,5-dimethylhexane-2,5-dihydroperoxide, dicumyl peroxide, benzoyl peroxide, t-butylcumyl peroxide, 2,5-dimethyl-2,5. -Peroxide-based initiators such as di (peroxybenzoyl) hexyne-3, di-t-butyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, lauroyl peroxide; azobisisobutylnitrile, azobis Examples thereof include azo initiators such as cyclohexanecarbonitrile, methyl azobisisobutyrate, azobisisobutylamidine hydrochloride, and 4,4′-azobis-4-cyanovaleric acid. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the photopolymerization initiator include diethoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, and 4- (2-hydroxyethoxy) phenyl. -(2-hydroxy-2-propyl) ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1,2-hydroxy-2-methyl-1-phenylpropan-1-one Acetophenone-based or ketal-based photopolymerization of 2-methyl-2-morpholino (4-methylthiophenyl) propan-1-one, 1-phenyl-1,2-propanedione-2- (o-ethoxycarbonyl) oxime, etc. Agents: benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isobuty Benzoin ether photopolymerization initiators such as ether and benzoin isopropyl ether; benzophenone, 4-hydroxybenzophenone, methyl o-benzoylbenzoate, 2-benzoylnaphthalene, 4-benzoylbiphenyl, 4-benzoylphenyl ether, acrylated benzophenone, 1 Benzophenone photopolymerization initiators such as 1,4-benzoylbenzene; thioxanthone photopolymerization such as 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone Initiators; Examples of other photopolymerization initiators include ethyl anthraquinone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and 2,4,6-trimethylbenzo. Ruphenylethoxyphosphine oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, bis (2,4-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, methylphenylglyoxyester, 9, Examples include 10-phenanthrene, acridine compounds, triazine compounds, and imidazole compounds. These may be used individually by 1 type and may use 2 or more types together.

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

The said polymerization initiator may be used individually by 1 type, and may mix and use 2 or more types.
The content of the polymerization initiator is preferably 0.5 parts 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 total content of the compound having radical polymerizability and the monomer.

The surface layer can be formed by a method for producing an electrophotographic photoreceptor described later.
The average thickness of the surface layer is preferably 1 μm to 30 μm, more preferably 2 μm to 20 μm, still more preferably 4 μm to 15 μm. When the average thickness is less than 1 μm, the thickness is too small with respect to the amount of indentation on the surface of the electrophotographic photosensitive member when carrier adhesion or the like occurs, so that sufficient durability cannot be ensured in many cases. On the other hand, if the average thickness is greater than 30 μm, it may cause a problem such as an increase in residual potential. Therefore, it is necessary to form the surface layer with a suitable film thickness so as to ensure a margin for wear and scratches and to reduce the occurrence of residual potential.

<< Photosensitive layer of laminated structure >>
As described above, the photosensitive layer having the laminated structure is formed by laminating a charge generation layer and a charge transport layer in this order.

-Charge generation layer-
The charge generation layer contains at least a charge generation material, and includes a binder resin and, if necessary, other components.

There is no restriction | limiting in particular as said charge generation substance, Although it can select suitably according to the objective, Either an inorganic material and an organic material can be used.
The inorganic material is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, and selenium-arsenic compounds. .
The organic material is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine; azulenium salt pigments, squaric acid methine pigments, and carbazole skeletons. Azo pigments having a triphenylamine skeleton, azo pigments having a diphenylamine skeleton, azo pigments having a dibenzothiophene skeleton, azo pigments having a fluorenone skeleton, azo pigments having an oxadiazole skeleton, azo having a bisstilbene skeleton Pigment, azo pigment having distyryl oxadiazole skeleton, azo pigment having distyryl carbazole skeleton, perylene pigment, anthraquinone or polycyclic quinone pigment, quinoneimine pigment, diphenylmethane or triphenylmethane face , Benzoquinone or naphthoquinone pigments, cyanine and azomethine pigments, indigoid pigments, and bisbenzimidazole pigments. These may be used individually by 1 type and may use 2 or more types together.

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

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

A method for forming the charge generation layer is not particularly limited and may be appropriately selected depending on the purpose. For example, the charge generation material and the binder resin are dissolved or dispersed in the other components such as the solvent. And a method of forming the coating liquid obtained by applying the coating liquid on the support and drying it. In addition, the said coating liquid can be apply | coated by the casting method etc., for example.
There is no restriction | limiting in particular as average thickness of the said charge generation layer, Although it can select suitably according to the objective, 0.01 micrometer-5 micrometers are preferable, and 0.05 micrometer-2 micrometers are more preferable.

-Charge transport layer-
The charge transport layer is required to have a high electric resistance in order to achieve the purpose of holding a charged charge. Further, in order to achieve the purpose of obtaining a high surface potential with the charged charge held, it is required that the dielectric constant is small and the charge mobility is good.

The charge transport layer contains a charge transport material, a binder resin, and further contains other components as required.
When the charge transport layer is a surface layer, the charge transport layer contains a filler and an aromatic hydrocarbon, and the extraction temperature is 230 ° C. for 15 minutes, and the cryotrap temperature is −190 ° C. for 15 minutes. The content of the aromatic hydrocarbon in the photosensitive layer measured by heat extraction gas chromatograph mass spectrometry under the extraction conditions is 100 mass ppm to 2,500 mass ppm.

  The charge transport material is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include an electron transport material, a hole transport material, and a polymer charge transport material.

  The electron transport material is not particularly limited and may be appropriately selected depending on the intended purpose. For example, chloroanil, bromilyl, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone 2,4,5,7-tetranitro-9-fluorenone, 2,4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-indeno 4H-indeno [ 1,2-b] thiophen-4-one, 1,3,7-trinitrodibenzothiophene-5,5-dioxide and the like. These may be used individually by 1 type and may use 2 or more types together.

  The hole transport material is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include oxazole derivatives, oxadiazole derivatives, imidazole derivatives, triphenylamine derivatives, 9- (p-diethylaminostyrylanthracene). ), 1,1-bis- (4-dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazoline, phenylhydrazones, α-phenylstilbene derivatives, thiazole derivatives, triazole derivatives, phenazine derivatives, acridine derivatives, benzofuran derivatives, Examples thereof include benzimidazole derivatives and thiophene derivatives. These may be used individually by 1 type and may use 2 or more types together.

Examples of the polymer charge transport material include those having the following structure.
Examples of (a) a polymer having a carbazole ring include, for example, poly-N-vinylcarbazole, JP-A-50-82056, JP-A-54-9632, JP-A-54-11737, JP-A-5-11737. Examples thereof include compounds described in JP-A-4-175337, JP-A-4-183719, and JP-A-6-234841.
(B) Examples of the polymer having a hydrazone structure include, for example, JP-A-57-78402, JP-A-61-20953, JP-A-61-296358, JP-A-1-134456, Compounds described in Kaihei 1-179164, JP-A-3-180851, JP-A-3-180852, JP-A-3-50555, JP-A-5-310904, and JP-A-6-234840 Etc.
(C) Examples of the polysilylene polymer include, for example, JP-A-63-285552, JP-A-1-88461, JP-A-4-264130, JP-A-4-264131, and JP-A-4-264132. And compounds described in JP-A-4-264133 and JP-A-4-289867.
(D) As a polymer having a triarylamine structure, for example, N, N-bis (4-methylphenyl) -4-aminopolystyrene, JP-A-1-134457, JP-A-2-282264, Examples thereof include compounds described in Kaihei 2-304456, JP-A-4-133605, JP-A-4-133066, JP-A-5-40350, and JP-A-5-202135.
(E) As other polymers, for example, a formaldehyde condensation polymer of nitropyrene, JP-A-51-73888, JP-A-56-15049, JP-A-6-234363, JP-A-6-234837 And the compounds described in the Japanese Patent Publication.

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

The binder resin in the charge transport layer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include polycarbonate resin, polyester resin, methacrylic resin, acrylic resin, polyethylene resin, polyvinyl chloride resin, and polyacetic acid. Vinyl resin, polystyrene resin, phenol resin, epoxy resin, polyurethane resin, polyvinylidene chloride resin, alkyd resin, silicone resin, polyvinyl carbazole resin, polyvinyl butyral resin, polyvinyl formal resin, polyacrylate resin, polyacrylamide resin, phenoxy resin, etc. Can be mentioned. These may be used individually by 1 type and may use 2 or more types together.
The charge transport layer may also contain a copolymer of a crosslinkable binder resin and a crosslinkable charge transport material.

  There is no restriction | limiting in particular as said other component, According to the objective, it can select suitably, For example, a solvent, a plasticizer, a leveling agent, antioxidant, etc. are mentioned.

The method for forming the charge transport layer is not particularly limited and can be appropriately selected depending on the purpose. For example, the charge transport material and the binder resin are dissolved or dispersed in the other components such as the solvent. And a method of forming the coating solution obtained by applying the coating solution on the charge generation layer and drying it. In addition, the said coating liquid can be apply | coated by the casting method etc., for example.
The average thickness of the charge transport layer is preferably 5 μm to 100 μm, and the charge transport layer has been made thinner in response to the recent demand for higher image quality, in order to achieve higher image quality of 1,200 dpi or more. Is more preferably 5 μm to 30 μm.

<< Photosensitive layer with a single layer structure >>
The photosensitive layer having a single layer structure contains a charge generation material, a charge transport material, and a binder resin, and further contains other components as necessary.
In the case where the photosensitive layer having the single layer structure is a surface layer, the photosensitive layer contains a filler and an aromatic hydrocarbon, is extracted at 230 ° C. for 15 minutes, and a cryotrap temperature is −190 ° C. The content of the aromatic hydrocarbon in the photosensitive layer measured by thermal extraction gas chromatograph mass spectrometry under the extraction condition for 1 minute is 100 mass ppm to 2,500 mass ppm.

When a photosensitive layer having a single layer structure is provided by a casting method, the photosensitive layer having a single layer structure is formed by, for example, dissolving or dispersing at least a charge generation material, a binder resin, and a charge transport material in a solvent, and then applying the solution. It can be formed by drying. Moreover, a plasticizer etc. can also be added to the said photosensitive layer of a single layer structure as needed.
The average thickness of the single-layer type photosensitive layer is preferably 5 μm to 100 μm, and more preferably 5 μm to 50 μm. When the average thickness is less than 5 μm, the chargeability may be lowered, and when it exceeds 100 μm, the sensitivity may be lowered.

<Support>
The support is not particularly limited as long as it has conductivity of 10 ¹⁰ Ω · cm or less, and can be appropriately selected according to the purpose. An endless belt (such as an endless nickel belt or an endless stainless steel belt) disclosed in Japanese Patent Laid-Open No. 52-36016 may be used.

  There is no restriction | limiting in particular as a formation method of the said support body, According to the objective, it can select suitably, For example, a metal (aluminum, nickel, chromium, nichrome, copper, gold | metal | money, silver, platinum etc.) or a metal oxide A method of forming by depositing or sputtering (tin oxide, indium oxide, etc.) and coating on a support (film, cylindrical plastic, paper, etc.); metal (aluminum, aluminum alloy, nickel, stainless steel, etc.) For example, by extruding, drawing, etc., and subjecting to surface treatment (cutting, superfinishing, polishing, etc.).

The support may be provided with a conductive layer on the support.
The method for forming the conductive layer is not particularly limited and may be appropriately selected according to the purpose. For example, the conductive layer and the binder resin may be dispersed or dissolved in a solvent as necessary. A method of forming the coating liquid on the support by forming the coating liquid on a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, and Teflon (registered trademark). Examples include a method of forming using a heat-shrinkable tube containing powder.

  There is no restriction | limiting in particular as said electroconductive powder, According to the objective, it can select suitably, For example, carbon powder, acetylene black; Metal powder, such as aluminum, nickel, iron, nichrome, copper, zinc, silver; Examples thereof include conductive tin oxide and metal oxide powders such as ITO.

  The binder resin used for the conductive layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, polystyrene resin, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-anhydrous Maleic acid 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, Examples include polyvinyl butyral resin, polyvinyl formal resin, polyvinyl toluene resin, poly-N-vinyl carbazole resin, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, alkyd resin, and the like. These may be used individually by 1 type and may use 2 or more types together.

  There is no restriction | limiting in particular as a solvent used for the said electroconductive layer, According to the objective, it can select suitably, For example, tetrahydrofuran, a dichloromethane, methyl ethyl ketone, toluene etc. are mentioned.

<Other layers>
There is no restriction | limiting in particular as said other layer, According to the objective, it can select suitably, For example, an undercoat layer, an intermediate | middle layer, etc. are mentioned.

-Undercoat layer-
The undercoat layer can be provided between the support and the photosensitive layer.
The undercoat layer contains a binder resin, and further contains other components such as an antioxidant, a fine powder pigment, and a coupling agent as necessary.

  The binder resin is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include water-soluble resins such as polyvinyl alcohol, casein and sodium polyacrylate; alcohols such as copolymer nylon and methoxymethylated nylon. Soluble resins; curable resins that form a three-dimensional network structure such as polyurethane, melamine resin, phenol resin, alkyd-melamine resin, and epoxy resin. These may be used individually by 1 type and may use 2 or more types together. Among these, a resin having a high solvent resistance with respect to a general organic solvent is preferable in that the photosensitive layer is coated on the resin with a solvent.

  The fine powder pigment contained in the undercoat layer is not particularly limited as long as it is a pigment that can prevent moire, reduce residual potential, etc., and can be appropriately selected according to the purpose. Examples thereof include metal oxides such as titanium, silica, alumina, zirconia, tin oxide, and indium oxide.

  There is no restriction | limiting in particular as a coupling agent contained in the said undercoat layer, According to the objective, it can select suitably, For example, a silane coupling agent, a titanium coupling agent, a chromium coupling agent etc. are mentioned.

The method for forming the undercoat layer is not particularly limited and may be appropriately selected depending on the purpose, for example, forming method using a solvent and coating method as the photosensitive layer; Al ₂ O ₃ the anode Examples include a method of forming by oxidation; an organic material such as polyparaxylylene (parylene); a method of forming an inorganic material such as SiO ₂ , SnO ₂ , TiO ₂ , ITO, and CeO ₂ by a vacuum thin film manufacturing method.
There is no restriction | limiting in particular as average thickness of the said undercoat layer, Although it can select suitably according to the objective, 0.1 micrometer-10 micrometers are preferable, and 1 micrometer-5 micrometers are more preferable.

-Intermediate layer-
An intermediate layer can be provided between the charge transport layer and the surface layer or between the photosensitive layer and the surface layer.
The binder resin contained in the intermediate layer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include polyamide, alcohol-soluble nylon, water-soluble polyvinyl butyral, polyvinyl butyral, and polyvinyl alcohol. .

There is no restriction | limiting in particular as a formation method of the said intermediate | middle layer, According to the objective, it can select suitably, For example, the method etc. which form using the solvent and coating method similar to the said photosensitive layer are mentioned.
There is no restriction | limiting in particular as average thickness of the said intermediate | middle layer, Although it can select suitably according to the objective, 0.05 micrometer-2 micrometers are preferable.

  In the electrophotographic photosensitive member of the present invention, in order to improve environmental resistance, in particular, for the purpose of preventing a decrease in sensitivity and an increase in residual potential, a surface layer, a charge generation layer, a charge transport layer, an undercoat layer, a single layer Antioxidants, plasticizers, lubricants, ultraviolet absorbers and the like can be added to each layer such as the mold type photosensitive layer and the intermediate layer.

Here, the electrophotographic photosensitive member of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view showing an example of the layer structure of the electrophotographic photosensitive member of the present invention, in which a photosensitive layer 202 having a single layer structure is provided on a support 201. In this case, the photosensitive layer 202 is a surface layer. FIG. 2 shows a structure in which a surface layer 206 is laminated on a photosensitive layer 202 having a single layer structure in FIG. 1, and the photosensitive layer 202 having a single layer structure and the surface layer 206 constitute a photosensitive layer 207.
FIGS. 3, 4 and 5 are schematic views showing other examples of the layer structure of the electrophotographic photosensitive member of the present invention. In FIG. 3, the photosensitive layer includes a photosensitive layer 207 having a laminated structure including a charge generation layer (CGL) 203 and a charge transport layer (CTL) 204. In this case, the charge transport layer 204 is a surface layer.
FIG. 4 includes an undercoat layer 205 between the support 201 and the charge generation layer (CGL) 203, and the charge generation layer (CGL) 203 and the charge transport layer (CTL) are provided on the undercoat layer 205. A photosensitive layer 207 having a laminated structure composed of 204 is provided. In this case, the charge transport layer 204 is a surface layer.
FIG. 5 shows a structure in which the surface layer 206 is laminated on the charge transport layer 204 in FIG. 4, and the charge generation layer 203, the charge transport layer 204, and the surface layer 206 constitute the photosensitive layer 207.

<Method for producing electrophotographic photoreceptor>
The method for producing an electrophotographic photoreceptor used in the present invention is a method for producing the electrophotographic photoreceptor of the present invention,
It includes a surface layer coating solution coating step and a drying step, and further includes other steps as necessary.

-Surface layer coating solution application process-
The surface layer coating solution coating step includes a surface layer coating solution containing a filler and at least one aromatic hydrocarbon selected from xylene, toluene, and benzene on the support or the photosensitive layer. It is the process of apply | coating.

In the first embodiment, the surface layer coating solution contains a filler, at least one aromatic hydrocarbon selected from xylene, toluene, and benzene, a binder resin, and a compound having a charge transporting structure. Further, it contains other components as required.
The content of at least one aromatic hydrocarbon selected from xylene, toluene, and benzene in the surface layer coating solution of the first embodiment is preferably 1% by mass to 20% by mass.

In the second embodiment, the surface layer coating solution is a filler, at least one aromatic hydrocarbon selected from xylene, toluene, and benzene, and a polymerizable compound having a charge transporting structure (for example, monofunctional). And a radically polymerizable compound having a charge transporting structure and a trifunctional or higher functional radically polymerizable monomer having no charge transporting structure).
The content of at least one aromatic hydrocarbon selected from xylene, toluene, and benzene in the surface layer coating solution of the second embodiment is preferably 1% by mass to 20% by mass.

When the radically polymerizable monomer is a liquid in the second form, the surface layer coating liquid may be applied by dissolving other components in the first form and the second form. In both cases, the coating is diluted with a solvent as necessary.
The solvent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include alcohols such as methanol, ethanol, propanol and butanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; acetic acid Examples include ester systems such as ethyl and butyl acetate; ether systems such as tetrahydrofuran, dioxane, and propyl ether; halogen systems such as dichloromethane, dichloroethane, trichloroethane, and chlorobenzene; and cellosolv systems such as methyl cellosolve, ethyl cellosolve, and cellosolve acetate. These may be used individually by 1 type and may use 2 or more types together. The dilution rate with the solvent varies depending on the solubility of the surface layer coating solution, the coating method, and the target film thickness, and is arbitrary.
The application can be performed using, for example, dip coating, spray coating, bead coating, ring coating, or the like.

Examples of the other components include additives such as various plasticizers (for the purpose of stress relaxation and adhesion improvement), leveling agents, and low molecular charge transport materials having no radical reactivity.
As the plasticizer, for example, those used in general resins such as dibutyl phthalate and dioctyl phthalate can be used, and the amount used is 20% by mass or less based on the total solid content of the surface layer coating solution. Is preferable, and 10 mass% or less is more preferable.
As the leveling agent, for example, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, polymers or oligomers having a perfluoroalkyl group in the side chain can be used, and the amount used is that of the surface layer coating liquid. 3 mass% or less is preferable with respect to the total solid content.

-Drying process-
The said drying process is a process of heat-drying for 10 minutes-30 minutes at 100 to 150 degreeC after apply | coating the said surface layer coating liquid.

  The drying condition is preferably 100 ° C. to 150 ° C. for 10 minutes to 30 minutes, more preferably 120 ° C. to 140 ° C. for 10 minutes to 30 minutes. Under this drying condition, the content of the aromatic hydrocarbon in the photosensitive layer (surface layer) can be 100 ppm to 2,500 ppm by mass.

When the surface layer is not cured as in the first embodiment, it is heated and dried immediately after the surface layer coating solution is applied.
In the case of curing the surface layer as in the second embodiment, after applying the surface layer coating liquid, it is cured by applying light energy from the outside and then drying by heating. As the energy of the light, a UV irradiation light source such as a high pressure mercury lamp or a metal halide lamp mainly having an emission wavelength in ultraviolet light can be used. Selection is also possible. In addition, the reactivity of the crosslinking reaction by radical polymerization is greatly affected by the temperature, and the surface temperature of the coating film during light irradiation is preferably maintained at 20 ° C. or higher and 80 ° C. or lower. The surface temperature control means of the coating film may be any method as long as the above temperature range can be maintained, but a method of controlling the temperature using a heat medium is preferable.

In order to accelerate the curing reaction, it is preferable to significantly reduce the oxygen concentration of the atmosphere during heating or UV light irradiation. Further, at this time, when UV light is irradiated, it is irradiated with UV light while rotating, but it is more preferable to lower the oxygen concentration in the surrounding atmosphere including not only the portion that is exposed to UV light but also the portion that is not exposed to UV light. . Thereby, since oxygen inhibition at the time of radical polymerization reaction can be remarkably reduced, a surface layer having a higher crosslinking density can be obtained.
When forming by spray coating, it is also effective to fill the inside of the coating facility with nitrogen and reduce the oxygen concentration, or to dry the touch.

-Other processes-
Examples of the other steps include a photosensitive layer forming step, an undercoat layer forming step, and an intermediate layer forming step.

Here, a method for producing an electrophotographic photoreceptor using the surface layer coating solution of the second embodiment will be described.
For example, an acrylate monomer having three acryloyloxy groups is used as a tri- or more functional radical polymerizable monomer having no charge transport structure, and one acryloyloxy is used as a radical polymerizable compound having a monofunctional charge transport structure. When using a triarylamine compound having a group, the use ratio thereof is 7: 3 to 3: 7, and a polymerization initiator is added in an amount of 3% by mass to 20% by mass with respect to the total amount of these acrylate compounds, and A solvent is added to prepare a coating solution.
In the charge transport layer that is the lower layer of the surface layer, for example, when using a triarylamine donor as a charge transport material and a polycarbonate resin as a binder resin, and forming the surface layer by spray coating, the surface layer coating As the solvent of the liquid, for example, tetrahydrofuran, 2-butanone, ethyl acetate and the like are preferable, and the use ratio is 3 to 10 times the total amount of the acrylate compound. The cured surface layer is preferably insoluble in an organic solvent. A film that is not sufficiently cured is soluble in an organic solvent and has a low crosslink density, so that the mechanical durability is also low.
For example, the surface layer coating solution prepared above is applied by spraying etc. on a photoreceptor in which an undercoat layer, a charge generation layer, and a charge transport layer are sequentially laminated on a support such as an aluminum cylinder, and is dry to the touch. Then, it is cured by light irradiation.
For UV irradiation, uses a metal halide lamp, illuminance 50 mW / cm ² or more, the rotation preferably is 1000 mW / cm ² or less, for example, the case of irradiation with UV light of 700 mW / cm ^2, upon curing, for example, a drum Then, uniformly irradiate all surfaces for about 2 minutes. At this time, using a heat medium or the like, control is performed so that the surface temperature does not become too high. After the curing, at least one aromatic hydrocarbon selected from xylene, toluene, and benzene may be contained in the photosensitive layer (surface layer) at 100 ppm to 2,500 ppm, and the temperature is 100 ° C. to 150 ° C. for 10 minutes to 30 minutes. By heating, the electrophotographic photoreceptor of the present invention can be obtained.

(Image forming apparatus and image forming method)
The image forming apparatus of the present invention comprises an electrophotographic photosensitive member, a charging unit, an exposing unit, a developing unit, and a transferring unit, and a lubricating substance applying unit, and other components appropriately selected as necessary. For example, fixing means, cleaning means, static elimination means, recycling means, control means, and the like.
The electrophotographic photoreceptor is the electrophotographic photoreceptor of the present invention.
The image forming method used in the present invention includes a charging step, an exposure step, a development step, and a transfer step, and includes a lubricating substance coating step, and other steps appropriately selected as necessary, for example, a fixing step. A cleaning process, a charge removal process, a recycling process, a control process, and the like.

  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 lubricating substance applying step can be performed by the lubricating substance applying unit, and 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 type charging means for charging in a non-contact manner with the photoreceptor is used.
As the non-contact charging means, for example, non-contact charging means using corona discharge, needle electrode device, solid discharge element; conductive or semiconductive disposed with a small 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 charging means and a scorotron charging means having a characteristic of giving a constant potential.
The coroton charging means is composed of a casing electrode that occupies a half space around the discharge wire and a discharge wire placed substantially at the center thereof.
The scorotron charging means is obtained by adding a grid electrode to the corotron charging means, 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 directly projects an original onto an electrophotographic photosensitive member by an optical system, and the digital optical system receives image information as an electrical signal, converts this into an optical signal, and converts it into an electrophotographic image. It is an optical system that exposes a photoreceptor to form 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 means 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 (toner 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 unit supplies either the carrier or the two-component developer to the inside of the developing unit, and either the carrier or the two-component developer accommodated in the developing unit is provided outside the developing unit. It is preferable to have discharging means for discharging.
The developing unit is not particularly limited as long as it can be developed using, for example, the toner or the developer, and can be appropriately selected from known ones. For example, it is preferable to include at least a developing unit that accommodates the toner or developer and can apply the toner or developer to the electrostatic latent image in a contact or non-contact manner.

The developing unit may be a dry developing type, a wet developing type, a single color developing unit, or a multicolor 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 means, for example, the toner and the carrier are mixed and stirred, and the toner is charged by friction at that time, and held on the surface of the rotating magnet roller in a raised state, thereby forming a magnetic brush. . Since the magnet roller is disposed in the vicinity of the photoconductor, a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is applied to the surface of the photoconductor by an electric attractive force. Moving. As a result, the electrostatic latent image formed in the exposure step is developed with the toner, and a visible image with the toner is formed on the surface of the photoreceptor.
The developer accommodated in the developing means is a developer containing the toner, and a two-component developer composed of a toner and a carrier is preferably used as the developer.

  The toner used for forming the toner image is not particularly limited and may be a known toner. For example, it contains at least a binder resin, a colorant, and an external additive, and preferably a release agent. It contains a charge control agent, and further contains other components as required.

<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 full color toner as the toner, and a composite transfer image; An embodiment including a secondary transfer step of transferring a transfer image onto a recording medium is more preferable.
The transfer can be performed, for example, by charging the photosensitive member using a transfer charging unit with 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) preferably includes at least a transfer unit that peels and charges the visible image formed on the photoconductor toward the recording medium. 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 unit, 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, and a combination of a roller and a roller. However, the warm-up time can be shortened, and in terms of realizing energy saving, the fixing is also performed. A combination of an endless belt and a roller having a small heat capacity is preferable from the viewpoint of expanding the possible width.

<Lubricant substance application process and lubricant substance application means>
The lubricating substance application step mainly reduces the coefficient of friction of the photosensitive member surface with respect to the cleaning blade over a long period of time by supplying the lubricating substance onto the photosensitive member by the lubricating substance applying means and applying it. It is installed as a purpose.
The lubricating substance is not particularly limited and may be appropriately selected depending on the intended purpose. However, fatty acid metal salt-based lubricating substances are preferred. Examples of the fatty acid metal salt-based lubricating substance include zinc stearate, aluminum stearate, calcium stearate and the like.
The supply amount of the lubricating substance to the surface of the photoreceptor is not particularly limited and can be appropriately selected according to the purpose, but is preferably 5 mg to 100 mg per 1,000 revolutions of the photoreceptor.
The lubricating substance is applied to the surface of the photoconductor to facilitate cleaning of spherical toner that is difficult to clean, and blade squeal and blade edge wear that are likely to occur when the cleaning blade and the photoconductor are rubbed. Trouble can be solved. Further, the toner releasability is improved, and the occurrence of abnormal images such as voids can be suppressed.

<Other processes and other means>
-Static elimination process and static elimination means-
The neutralization step is a step of performing neutralization by applying a neutralization bias to the photosensitive member or irradiating neutralization light, and can be suitably performed by a neutralization unit.
The charge eliminating means is not particularly limited, and may be selected from known charge eliminating means as long as it can remove the surface charge of the photosensitive member. For example, a charging means for applying a charge eliminating bias, a charge eliminating lamp, and the like. Can be mentioned.

-Cleaning process and cleaning means-
The cleaning step is a step of removing the toner remaining on the photoconductor, and can be suitably performed by a cleaning unit.
The cleaning means is not particularly limited and may be selected from known cleaners as long as it can remove the electrophotographic toner remaining on the photoreceptor, and includes, for example, a magnetic brush cleaner, a static cleaner, and the like. Examples thereof include an electric brush cleaner, a magnetic roller cleaner, a blade cleaner, a brush cleaner, and a web cleaner.

-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.

Here, the image forming apparatus and the image forming method of the present invention will be described with reference to the drawings.
FIG. 7 is a schematic view showing an example of the image forming apparatus of the present invention. The image forming apparatus shown in FIG. 7 includes a drum-shaped photoreceptor 1, a charger 3, a pre-transfer charger 7, a transfer charger 110, a separation charger 111, and a pre-cleaning charger 113.

  The shape of the photoreceptor 1 is not limited to a drum shape, and may be, for example, a sheet shape or an endless belt shape. In addition, as various chargers, corotron, scorotron, solid state charging means (solid state charger), contact arrangement, gap tape and a step on the end are provided in close proximity with a gap between the photosensitive member. Any known means such as a charged roller can be used.

As the transfer means, the above charging means can be generally used, but a combination of a transfer charger and a separation charger as shown in the figure is effective.
Light sources 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), an electroluminescence (EL), etc. All things can be used. Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.
Such a light source or the like can irradiate the photosensitive member with light by providing a transfer step, a static elimination step, a cleaning step, or a pre-exposure step in combination with light irradiation in addition to the steps shown in FIG. .

  The toner image developed on the photosensitive member 1 by the developing unit 6 is transferred to the recording medium 9, but not all is transferred, and the toner remains on the photosensitive member 1. If such a residual toner is not cleaned and the next copying process is carried out, defective charging or a problem in forming an electrostatic latent image due to exposure will occur. Therefore, it is generally necessary to remove untransferred residual toner using a cleaning unit. As the cleaning means, the cleaning brush 114 and the cleaning blade 115 can be used alone or in combination, and examples of the cleaning brush include a fur brush and a mag fur brush. In FIG. 7, 8 is a registration roller, and 112 is a separation claw.

  The cleaning blade 115 includes, for example, a urethane resin, a silicone resin, a fluororesin, a urethane elastomer, a silicone elastomer, and a fluoroelastomer as an elastic body having a low friction coefficient. As the cleaning blade 115, a thermosetting urethane resin is preferable, and a urethane elastomer is particularly preferable from the viewpoints of wear resistance, ozone resistance, and contamination resistance. Elastomer includes rubber. The cleaning blade 115 preferably has a hardness (JIS-A) of 65 degrees to 85 degrees. The cleaning blade 115 preferably has a thickness of 0.8 mm to 3.0 mm and a protrusion amount of 3 mm to 15 mm. Furthermore, as other conditions, the contact pressure, the contact angle, the amount of biting, and the like can be determined as appropriate.

  Such a cleaning means that comes into contact with the photoconductor has high toner removal performance. However, as a matter of course, a mechanical hazard is given to the photoconductor to cause abrasion of the surface layer of the photoconductor. The photoreceptor having a surface layer suitably used in the present invention has a remarkably high wear resistance of the surface layer, and therefore can stably output a good image even in an image forming apparatus having a cleaning unit in contact with the surface. Can do.

The image forming apparatus of the present invention includes a lubricating substance applying unit 116 that supplies and applies a lubricating substance to the surface of the photoreceptor. In particular, in recent years, spherical toners, which are advantageous for improving the image quality of electrophotography, have been put into practical use. However, spherical toners are difficult to blade-clean as compared with conventional pulverized toners. Are known. Therefore, measures such as increasing the contact pressure of the cleaning blade and using a urethane rubber blade having high hardness are being taken.
These methods tend to increase the hazard to the surface of the photoconductor on which the blade abuts. In fact, it has been found that the use of spherical toner tends to increase the surface wear of the photoconductor. Since the photoreceptor having a filler-containing surface layer suitably used in the present invention has very high wear resistance, the filler-containing surface layer is hardly worn even under conditions with a large hazard as described above. In some cases, problems such as blade squeal and blade edge wear, which are considered to be due to the high friction coefficient of the cleaning blade, may occur.
Therefore, in the image forming apparatus of the present invention, it is preferable that the image forming apparatus includes a lubrication material coating unit that supplies and coats a lubrication material on the surface of the electrophotographic photosensitive member, whereby friction of the surface of the electrophotographic photosensitive member with respect to the cleaning blade is achieved. The coefficient can be reduced over a long period of time, and the above problems can be solved.

FIG. 8 shows another example of the lubricating substance applying means.
In FIG. 8, a rod-like lubricating substance (solid matter) 116 is pressed against the cleaning brush 114. When the cleaning brush 114 rotates, the lubricating substance is scraped off, and the lubricating substance attached to the brush is removed. The mechanism is applied to the surface of the photoreceptor. In FIG. 8, reference numeral 115 denotes a cleaning blade.
Although the cleaning unit 117 is provided with the lubricating substance applying means shown in FIG. 8, there are advantages such as easy layout design around the drum and simplification of the apparatus, but the cleaning toner is lubricated. In some cases, a large amount of the active substance is mixed, so that it is difficult to recycle the toner or the brush cleaning efficiency is lowered. Although not shown in the drawings, the above problem can be solved by providing a coating unit having a lubricating material coating unit independently of the cleaning unit. In that case, the coating unit is preferably provided downstream of the cleaning unit. Furthermore, by providing coating units at a plurality of locations and operating them simultaneously or sequentially, it is possible to provide effects such as improving the coating efficiency of the lubricating material and controlling the consumption of the lubricating material.

  FIG. 9 is a schematic view showing another example of the process using the image forming apparatus according to the present invention. In FIG. 9, a photosensitive member 122 is driven by a driving roller 123, charged by a charging charger 129, image exposure by an image exposure light source 121, development (not shown), transfer using a transfer charger charging means 125, and a lubricating substance. Lubricating substance application by the coating unit 130, uniform application of the lubricating substance by the lubricating substance leveling blade 131, cleaning by the cleaning brush 126, and static elimination by the static elimination light source 128 are repeated. In FIG. 9, reference numeral 124 denotes a transfer roller, and 127 denotes a driven roller.

  FIG. 10 is a schematic configuration diagram of the full-color image forming apparatus of the present invention. The photosensitive drum 156 in FIG. 10 is driven by a laser optical device (not shown) after its surface is uniformly charged by a charging charger 153 using a corotron, a scorotron or the like while being rotated counterclockwise in FIG. An electrostatic latent image is carried by scanning with laser light (exposure) L. Since this scanning is performed based on single-color image information obtained by separating a full-color image into yellow, magenta, cyan, and black color information, a single-color image of yellow, magenta, cyan, or black is used on the photosensitive drum 156. An electrostatic latent image is formed.

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

  An intermediate transfer unit is disposed on the downstream side of the photosensitive drum 156 from the development position. This is because the intermediate transfer belt 158 stretched by the tension roller 159a, the intermediate transfer bias roller 157 as the transfer means, the secondary transfer backup roller 159b, and the belt drive roller 159c is rotated by the belt drive roller 159c. Move endlessly clockwise. The yellow toner image, the magenta toner image, the cyan toner image, and the black toner image developed on the photosensitive drum 156 enter an intermediate transfer nip where the latent image carrying drum 156 and the intermediate transfer belt 158 are in contact with each other. . Then, while being influenced by the bias from the intermediate transfer bias roller 157, the toner image is superimposed on the intermediate transfer belt 158 and primarily transferred to form a four-color superimposed toner image. The intermediate transfer method in which the toner images are superimposed using such an intermediate transfer belt is advantageous for color misregistration because the relative positioning of the electrophotographic photosensitive member and the intermediate transfer member can be relatively easily and accurately performed. Therefore, it can be said that this is an effective means for obtaining a high-quality full-color image.

  Then, the surface of the photosensitive drum 156 that has passed through the intermediate transfer nip in accordance with the rotation is cleaned of untransferred residual toner by the drum cleaning unit 155. The drum cleaning unit 155 cleans untransferred residual toner with a cleaning brush such as a fur brush or a mag fur brush, and uses a cleaning roller to which a cleaning bias is applied, a cleaning blade, or the like alone or in combination. It may be. Further, in FIG. 10, the cleaning unit 155 is also used as a lubricating substance applying unit.

  The surface of the photosensitive drum 156 from which the untransferred residual toner has been cleaned is discharged by the discharging lamp 154. Examples of the static elimination lamp 154 include 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 electroluminescence (EL). A semiconductor laser is used as the light source of the laser optical device. About these emitted lights, you may make it use only a desired wavelength range by various filters, such as a sharp cut filter, a band pass filter, a near-infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter.

  A transfer unit composed of various rollers such as a transfer conveyance belt 162, a transfer bias roller 163, and a drive roller is disposed on the lower side of the intermediate transfer unit in FIG. 10, and on the left side in FIG. A fixing unit 165 is provided. In the transfer unit, the endlessly moving transfer belt may be moved in the vertical direction in FIG. 10 by a moving means (not shown). At least one color toner image (yellow toner image) on the intermediate transfer belt 158 may be used. When the two-color or three-color superimposed toner image passes through the position facing the secondary transfer bias roller 163, the toner image is retracted to a position where it does not contact the intermediate transfer belt 158. Then, before the leading end of the four-color superimposed toner image on the intermediate transfer belt 158 enters the position facing the secondary transfer bias roller 163, it moves to the contact position with the intermediate transfer belt 158 to perform secondary transfer. Form a nip.

On the other hand, the registration roller pair 161 that sandwiches the recording medium 160 sent from a paper feeding cassette (not shown) between the two rollers can superimpose the recording medium 160 on the four-color superimposed toner image on the intermediate transfer belt 158. Feed toward the secondary transfer nip at the timing. The four-color superimposed toner image on the intermediate transfer belt 158 is secondarily transferred collectively onto the recording medium 160 under the influence of the secondary transfer bias from the paper transfer bias roller 163 in the secondary transfer nip. By this secondary transfer, a full color image is formed on the recording medium 160.
Then, the recording medium 160 on which the full-color image is formed is sent to the paper conveyance belt 164 by the transfer conveyance belt 162.
The conveyance belt 164 sends the recording medium 160 received from the transfer unit into the fixing unit 165.

The fixing unit 165 conveys the fed recording medium 160 while being sandwiched in a fixing nip formed by the contact between the heating roller and the backup roller.
The full color image on the recording medium 160 is fixed on the recording medium 160 under the influence of the heating from the heating roller and the pressure in the fixing nip.

  Although not illustrated, a bias for attracting the recording medium 160 may be applied to the transfer conveyance belt 162 and the paper conveyance belt 164. Further, a paper recording medium neutralization charger that neutralizes the recording medium 160 and three belt neutralization chargers that neutralize each belt (intermediate transfer belt 158, transfer conveyance belt 162, and conveyance belt 164) may be provided. Further, the intermediate transfer unit may include a belt cleaning unit having the same configuration as that of the drum cleaning unit 155, thereby cleaning untransferred residual toner on the intermediate transfer belt 158.

The image forming apparatus shown in FIG. 11 is a tandem color image forming apparatus. The illustrated tandem image forming apparatus includes an image forming apparatus main body 150, a paper feed table 200, a scanner 300, and an automatic document feeder (ADF) 400.
The image forming apparatus main body 150 is provided with an endless belt-like intermediate transfer member 50 at the center. The intermediate transfer member 50 is stretched around the support roller a (14), the support roller b (15), and the support roller c (16), and can rotate clockwise in FIG. In the vicinity of the support roller b (15), an intermediate transfer member cleaning means 17 for removing untransferred residual toner on the intermediate transfer member 50 is disposed. Four image forming units 18 of yellow, cyan, magenta, and black are opposed to the intermediate transfer member 50 stretched by the support roller a (14) and the support roller b (15) along the conveyance direction. The tandem developing means 120 arranged side by side are arranged. An exposure unit 21 is disposed in the vicinity of the tandem developing unit 120. A secondary transfer unit 22 is disposed on the side of the intermediate transfer member 50 opposite to the side on which the tandem developing unit 120 is disposed. In the secondary transfer unit 22, a secondary transfer belt 24, which is an endless belt, is stretched around a pair of rollers 23, and the recording medium conveyed on the secondary transfer belt 24 and the intermediate transfer member 50 are in contact with each other. Is possible. A fixing unit 25 is disposed in the vicinity of the secondary transfer unit 22.
In the tandem image forming apparatus of FIG. 11, a sheet reversing unit 28 for reversing the recording medium in order to form an image on both sides of the recording medium is disposed in the vicinity of the secondary transfer unit 22 and the fixing unit 25. Has been.

  Next, formation of a full-color image (color copy) using the tandem developing unit 120 will be described. That is, first, a document is set on the document table 130 of the automatic document feeder (ADF) 400, or the automatic document feeder 400 is opened and a document is set on the contact glass 32 of the scanner 300. 400 is closed.

When a start switch (not shown) is pressed, when the document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32, and then the document is set on the contact glass 32. Immediately after that, the scanner 300 is driven, and the first traveling body 33 and the second traveling body 34 travel. At this time, light from the light source is irradiated by the first traveling body 33 and reflected light from the document surface is reflected by the mirror in the second traveling body 34 and is received by the reading sensor 36 through the imaging lens 35 to be color. An original (color image) is read and used as black, yellow, magenta, and cyan image information.
The image information of black, yellow, magenta, and cyan is stored in each image forming unit 18 (black image forming unit, yellow image forming unit, magenta image forming unit, and cyan image) in the tandem developing unit 120. Each of the image forming units forms black, yellow, magenta, and cyan toner images. In FIG. 11, reference numeral 26 denotes a fixing belt, 27 denotes a pressure roller, 51 denotes a manual feed tray, and 52 denotes a separation roller.

  That is, each image forming means 18 (black image forming means, yellow image forming means, magenta image forming means, and cyan image forming means) in the tandem developing means 120 is respectively shown in FIG. Photoconductor 10 (black photoconductor 10K, yellow photoconductor 10Y, magenta photoconductor 10M, and cyan photoconductor 10C), charging means 60 for uniformly charging the photoconductor, and each color image information An exposure means for exposing the photosensitive member to each color image corresponding image (L in FIG. 12) and forming an electrostatic latent image corresponding to each color image on the photosensitive member; and the electrostatic latent image Developing means 61 for developing each color toner (black toner, yellow toner, magenta toner, and cyan toner) to form a toner image with each color toner; A transfer charging means (primary transfer charging means) 62 for transferring an image onto the intermediate transfer member 50, a photosensitive member cleaning means 63, and a charge eliminating means 64 are provided. Based on the image information of each color. Each monochrome image (black image, yellow image, magenta image, and cyan image) can be formed.

The black image, the yellow image, the magenta image, and the cyan image formed in this way are intermediate transfer members that are rotationally moved by the support roller a (14), the support roller b (15), and the support roller c (16). 50, a black image formed on the black photoconductor 10K, a yellow image formed on the yellow photoconductor 10Y, a magenta image formed on the magenta photoconductor 10M, and a cyan photoconductor 10C. The cyan image formed above is sequentially transferred (primary transfer).
Then, the black image, the yellow image, the magenta image, and the cyan image are superimposed on the intermediate transfer member 50 to form a composite color image (composite transfer image).

  On the other hand, in the paper feed table 200, one of the paper feed rollers 142 is selectively rotated to feed the recording medium from one of the paper feed cassettes 144 provided in multiple stages in the paper bank 143, and one sheet at a time by the separation roller 145. The paper is separated and sent to the paper feed path 146, transported by the transport roller 147, guided to the paper feed path 148 in the image forming apparatus main body 150, and abutted against the registration roller 49 to stop. Alternatively, the recording roller 142 is rotated to feed out the recording medium on the manual feed tray 51, separated one by one by the separation roller 52, put into the manual feed path 53, and abutted against the registration roller 49 and stopped. The registration roller 49 is generally used while being grounded, but may be used in a state where a bias is applied to remove paper dust from the recording medium.

  Then, the registration roller 49 is rotated in synchronization with the synthesized color image (composite transfer image) synthesized on the intermediate transfer member 50, and the recording medium is sent between the intermediate transfer member 50 and the secondary transfer means 22. Then, the composite color image (composite transfer image) is transferred (secondary transfer) onto the recording medium by the secondary transfer means 22, whereby the color image is transferred and formed on the recording medium. The residual toner on the intermediate transfer member 50 after image transfer is cleaned by the intermediate transfer member cleaning means 17. In FIG. 12, reference numeral 26 denotes a fixing belt, and 27 denotes a pressure roller.

The recording medium on which the color image has been transferred is conveyed by the secondary transfer means 22 and sent to the fixing means 25, where the combined color image (composite transfer image) is generated by heat and pressure. Is fixed on the recording medium. Thereafter, the recording medium is switched by the switching claw 55 and discharged by the discharge roller 56 and stacked on the paper discharge tray 57, or switched by the switching claw 55 and reversed by the sheet reversing means 28, and again led to the transfer position. After recording an image on the back side, the image is discharged by the discharge roller 56 and stacked on the discharge tray 57.
In FIG. 12, 65 is a developing sleeve, 66 is a stirring portion, 67 is a developing portion, 68 is a stirring screw, 69 is a partition plate, 70 is a developing case, 71 is a toner concentration sensor, 72 is a developing roller, and 73 is a doctor blade. , 74 is a lubricating substance, 75 is a cleaning blade, 76 is a cleaning brush, 77 is an electric field roller, 78 is a scraper, 79 is a recovery screw, and 80 is a toner recycling device.

  In the tandem method, electrostatic latent image formation and development for each color can be performed in parallel, so that the image formation speed can be made much faster than the revolver method. Further, the printer of FIG. 11 also employs an intermediate transfer system, and by mounting the electrophotographic photosensitive member of the present invention, a high-quality full-color image with little color misregistration can be repeated at a very high speed for a long period of time. Can be output.

(Process cartridge)
The process cartridge of the present invention comprises the electrophotographic photosensitive member of the present invention and at least one means selected from a charging unit, a developing unit, a transfer unit, a cleaning unit, a lubricating substance applying unit, and a charge eliminating unit. The image forming apparatus main body is detachable.

  Here, for example, as shown in FIG. 13, the process cartridge includes an electrophotographic photosensitive member 101, and includes a charging unit 102, a developing unit 104, and a cleaning unit 109, 103 is exposure by an exposure unit, and 105 is A recording medium 110 is a conveyance roller. In FIG. 13, the cleaning unit is provided with a lubricating substance applying unit. The lubricating substance 106 is pressed against the cleaning brush 108 of the cleaning unit 109, and the lubricating substance is applied by the cleaning brush 108. The blade 107 also serves as a lubricating material leveling blade.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Synthesis Example 1)
<Synthesis of a radical polymerizable compound having a charge transporting structure>
A radical polymerizable compound having a charge transporting structure represented by the following structural formula was synthesized by the methods described in Japanese Patent No. 3164426 and Japanese Patent Application Laid-Open No. 2011-039158.

(Synthesis Example 2)
<Synthesis of titanyl phthalocyanine crystal>
The titanyl phthalocyanine crystal was synthesized according to Japanese Patent Application Laid-Open No. 2004-83859.
When the obtained titanyl phthalocyanine powder was measured by X-ray diffraction spectrum, the Bragg angle 2θ with respect to CuKα ray (wavelength 1.542 mm) was 27.2 ° ± 0.2 °, the maximum peak and the minimum angle 7.3 ° ± 0.00. It has a peak at 2 °, and further has major peaks at 9.4 ° ± 0.2 °, 9.6 ° ± 0.2 °, 24.0 ° ± 0.2 °, and 7.3 A titanyl phthalocyanine powder having no peak between the peak at 0 ° and the peak at 9.4 ° and further having no peak at 26.3 ° was obtained. The results are shown in FIG.

Example 1
<Preparation of photoreceptor example 1>
A subbing layer having an average thickness of 3.5 μm is coated on an aluminum (Al) support having an outer diameter of 60 mm by a dipping method using an undercoating layer coating solution having the following composition, and heated and dried at 130 ° C. for 20 minutes. Formed.

-Undercoat layer coating solution-
-Alkyd resin (DIC, Beckolite M6401-50) ... 6 parts by mass-Melamine resin (DIC, Super Becamine G821-60) ... 4 parts by mass-Titanium dioxide powder (Ishihara Sangyo Co., Ltd.) Manufactured, tie-bake CR-EL) ... 40 parts by mass · 2-butanone ... 50 parts by mass

Next, dip coating was performed on the undercoat layer using a charge generation layer coating solution having the following composition, followed by heating and drying at 90 ° C. for 20 minutes to form a charge generation layer having an average thickness of 0.2 μm.
-Charge generation layer coating solution-
-Titanyl phthalocyanine of Synthesis Example 2-6 parts by mass-Butyral resin (BX-1, manufactured by Sekisui Chemical Co., Ltd.)-4 parts by mass-2-butanone-200 parts by mass

Next, dip coating was performed on the charge generation layer using a charge transport layer coating solution having the following composition, followed by heat drying at 135 ° C. for 20 minutes to form a charge transport layer having an average thickness of 22 μm.
-Charge transport layer coating solution-
-Z-type polycarbonate (TS-2050, manufactured by Teijin Chemicals Ltd.) ... 10 parts by mass-Charge transport material represented by the following structural formula: 10 parts by mass
・ Terrolahydrofuran: 100 parts by mass

Next, spray coating is performed on the charge transport layer using a crosslinked surface layer coating solution having the following composition, and light irradiation is performed under the conditions of a metal halide lamp, irradiation intensity: 500 mW / cm ² , irradiation time: 60 seconds. Further, heat drying was carried out at 135 ° C. for 20 minutes to form a crosslinked surface layer having an average thickness of 3.5 μm. As described above, photoconductor Example 1 was produced.
-Crosslinked surface layer coating solution-
Alumina (Sumitomo Chemical Co., Ltd., AA03, average primary particle size 0.3 μm) ... 3.0 parts by mass Unsaturated polycarboxylic acid polymer (BYK Chemie, BYK-P104) ... 0.06 Part by mass ・ Trifunctional or more radically polymerizable monomer having no charge transporting structure [trimethylolpropane acrylate] 5 parts by mass (manufactured by Nippon Kayaku Co., Ltd., KAYARAD TMPTA)
[Dipentaerythritol-caprolactone-modified hexaacrylate] 5 parts by mass (manufactured by Nippon Kayaku Co., Ltd., KAYARAD DPCA-120)
Aromatic hydrocarbon (xylene) 5 mass parts Radical polymerizable compound having a charge transporting structure represented by the following structural formula of Synthesis Example 1 10 mass parts
Photopolymerization initiator (Ciba Specialty Chemicals, Irgacure 184) ... 1 part by mass Tetrahydrofuran ... 95 parts by mass

(Examples 2 to 10)
-Production of photoreceptor examples 2 to 10-
In Example 1, except that the addition amount of tetrahydrofuran, the kind and addition amount of aromatic hydrocarbon, and the drying conditions of the crosslinked surface layer were changed as shown in Table 1-1 in the crosslinked surface layer coating solution. In the same manner as in Example 1, Photoreceptor Examples 2 to 10 were prepared.

(Comparative Examples 1-7)
-Production of photoconductor comparative examples 1-7-
In Example 1, except that the amount of tetrahydrofuran added to the crosslinked surface layer coating solution, the type and amount of aromatic hydrocarbon, and the drying conditions of the crosslinked surface layer were changed as shown in Table 1-1. In the same manner as in Example 1, photosensitive member comparative examples 1 to 7 were produced.

(Example 11)
-Preparation of photoreceptor example 11-
In Example 1, Photoconductor Example 11 was produced in the same manner as Example 1 except that the surface layer was changed to the following.
<Formation of surface layer>
On the charge transport layer, spray coating was performed using a surface layer coating solution having the following composition, followed by heat drying at 135 ° C. for 20 minutes to form a surface layer having an average thickness of 5.0 μm.
-Surface layer coating solution-
Alumina (Sumitomo Chemical Co., Ltd., AA03, average primary particle size 0.3 μm) ... 3.0 parts by mass Unsaturated polycarboxylic acid polymer (BYK-P104, BYK Chemie) ... 0.06 Mass parts-Polycarbonate (Z Polyca, manufactured by Teijin Chemicals Ltd.) ... 10 parts by mass-Aromatic hydrocarbon (xylene) ... 10 parts by mass-Charge transport material represented by the following structural formula ... 4 masses Part
・ Tetrahydrofuran ・ ・ ・ 220 parts by mass ・ Cyclopentanone ... 70 parts by mass

(Examples 12 to 18)
-Production of photoreceptor examples 12 to 18-
In Example 11, except that the amount of tetrahydrofuran added to the surface layer coating solution, the type and amount of aromatic hydrocarbon, and the drying conditions of the surface layer were changed as shown in Table 1-2. Similarly, Photoreceptor Examples 12 to 18 were produced.

(Comparative Examples 8 to 13)
-Production of Photoreceptor Comparative Examples 8-13-
In Example 11, except that the amount of tetrahydrofuran added to the surface layer coating solution, the type and amount of aromatic hydrocarbon, and the drying conditions of the surface layer were changed as shown in Table 1-2. Similarly, Photoconductor Comparative Examples 8 to 13 were produced.

<Aromatic hydrocarbon content in photosensitive layer>
A part (5 mg to 10 mg) of the photosensitive layer (crosslinked surface layer, surface layer) of each electrophotographic photoreceptor prepared was cut out and selected from xylene, toluene, and benzene by thermal extraction gas chromatography mass spectrometry under the conditions shown below. The content (mass ppm) of at least one kind of aromatic hydrocarbon was measured. The results are shown in Table 1.
〔Measurement condition〕
GC-MS device: QP-2010 manufactured by Shimadzu Corporation
Data analysis software: GCMS solution (NIST 20 MASS SPECTRAL LIB.) Manufactured by Shimadzu Corporation
・ Heat extraction conditions
Extraction temperature x time: 230 ° C x 15 minutes
Cryotrap temperature: -190 ° C (liquid nitrogen) x 15 minutes-Heating device: Py-2020D manufactured by Frontier Laboratories
Column: Ultrala ALLOY-5 L = 30 m, ID = 0.25 mm, File = 0.25 μm
Column heating: 50 ° C. (holding 1 minute) to 5 ° C./min to 80 ° C. to 40 ° C./min to 280 ° C. (holding 5 minutes)
Carrier gas pressure: 53.6 kPa constant Column flow rate: 1.0 mL / min
・ Ionization method: EI method (70 eV)
Injection mode: Split (1: 100)
・ Measurement mode: Ion selection (Selected Ion Monitoring; SIM method)

* "-" Shows below a measurement limit (5 mass ppm or less).
* "-" Shows below a measurement limit (5 mass ppm or less).

Various characteristics of each electrophotographic photosensitive member produced as described above were evaluated as follows. The results are shown in Table 2.
The surface roughness Ra of each electrophotographic photosensitive member was 0.11 μm ± 0.06 μm, and all the photosensitive members had the same surface shape.

<Evaluation of affinity of lubricating substances>
Each produced electrophotographic photosensitive member was mounted on a process cartridge, and a tandem full-color digital copying machine [manufactured by Ricoh Co., Ltd., imagio MPC7500 remodeling machine 1 (writing exposure wavelength: 780 nm, using zinc stearate as a lubricating substance, was used. The supply amount of the lubricating substance to the photoconductor as the consumption due to the change in the weight of the photosensitive substance was about 30 mg per 1,000 revolutions of the photoconductor.)] On the other hand, the image area is written with characters equivalent to 5% on the average), and the electrophotographic photosensitive member is taken out for each sheet output, and the coefficient of friction μ of the electrophotographic photosensitive member is determined as follows. Measurement was made to determine the number of output sheets at which the friction coefficient μ of the electrophotographic photosensitive member was 0.15 or less. The number of lubrication substance coatings increases in proportion to the number of output sheets, and the friction coefficient μ of the electrophotographic photosensitive member decreases due to the lubrication substance coating. It shows that the smaller the number of output sheets for which the friction coefficient μ of the electrophotographic photosensitive member is 0.15 or less, the better the affinity with the lubricating substance.

<Measuring method of friction coefficient μ of electrophotographic photosensitive member>
The coefficient of friction μ of the photosensitive member was measured using the Euler belt method described in JP-A-9-166919. As the belt, medium-quality high-quality paper is used, and the paper sheet is in the longitudinal direction. As shown in FIG. 14, the belt is stretched to ¼ of the circumference of the electrophotographic photosensitive member, and W is attached to one side of the belt. Apply a load of = 100 g, install a force gauge (spring balance) on the other side of the belt, observe the movement of the belt while pulling the force gauge gradually, read the load when the movement started, and use the following formula: Calculated. In FIG. 14, a 100 g weight is used as the load W, Type 6200 / T / A4 size paper / 30 mm width (cut in the direction of the gap) and two double clips manufactured by Ricoh Co., Ltd. are used as the belt.
μ = 2 / π × ln (F / W)
In the above equation, μ represents a friction coefficient, F represents a tensile force, and W represents a load (100 g).

<Evaluation of image forming apparatus>
Each produced electrophotographic photosensitive member is mounted on a process cartridge, and a tandem full-color digital copying machine [manufactured by Ricoh Co., Ltd., imagiMPC7500 remodeling machine 2 (writing exposure wavelength: 780 nm, the types of lubricating substances used are shown in Table 2) ). The supply amount of the lubricating substance to the photosensitive member was ½ of the supply amount of the modified machine 1. ], With a writing rate of 5% and a 100% chart (on the entire A4 size surface, a portion where characters equivalent to 5% of the image area are written on average and a black belt with an image area rate of 100% are written. A printing test including 300,000 prints in total was performed. At that time, as shown below, the exposure area potential (VL) of the image area ratio 5% part after the initial and printing durability test, the variation in the job, and the image area ratio 100% part due to medaka and filming. Was evaluated.

<Exposure section potential and job fluctuation>
To evaluate the variation within the job, first measure the exposed area potential (VL) of the electrophotographic photosensitive member using a surface potential meter (Model 344, manufactured by Trek Japan Co., Ltd.), and then continuously print 100 sheets as one job. Then, after repeating the job 10 times, the exposed area potential was measured again, and (VL after repeated printing)-(first VL) after the initial and printing durability test was regarded as the intra-job variation, and evaluated according to the following criteria.
[In-job variation criteria]
◎: Level with no problem ○: Level that changes slightly, but does not cause a problem within the range that can be corrected △: Level that changes are clearly recognized and slightly exceeds the allowable range ×: Level that changes greatly and is regarded as a problem

<Evaluation of medaka and filming>
For the 100% area area of the image, the presence or absence of local white spots and density reduction (such white spots occur when medaka and filming occur) in the black zone of the output image is visually confirmed. And evaluated according to the following criteria. This is because medaka and filming are likely to occur when the application state of the lubricating material is poor (insufficient application and uneven application).
[Decision criteria for medaka and filming]
◎: Level at which no abnormality is observed ○: White spot or density decrease is slightly recognized, but acceptable level △: Clear white spot or density drop can be confirmed, level exceeding the allowable level ×: White spot or Concentration drop is a problem level

From the results shown in Table 2, the electrophotographic photoreceptors of the present invention of Examples 1 to 18 have less in-job variation of the exposed area potential, and the affinity of the lubricating substance is improved. It was found that there was no occurrence of medaka and filming even when the amount was reduced.
On the other hand, if the content of at least one aromatic hydrocarbon selected from xylene, toluene, and benzene in the surface layer of the photosensitive layer increases, the fluctuation of the exposed area potential within the job increases, and the image blur occurs due to printing durability. It tends to occur easily. The electrophotographic photoreceptors of Examples 1 to 18 of the present invention have an excessively good affinity for the lubricating material, and are effective in suppressing the occurrence of medaka and filming, but the surface lubricating material that has deteriorated over time is imaged. It is difficult to remove and replace in the formation process, and image blur may occur due to a decrease in resistance of the deteriorated lubricating material. In the photosensitive layer of at least one aromatic hydrocarbon selected from xylene, toluene, and benzene It was found that by setting the content to 2,500 ppm or less, the image blur was a good level acceptable for practical use.

  As described above, according to the present invention, even if the supply amount of the lubricating substance is reduced, no medaka or filming occurs even in the long-term repeated use, and fluctuations in the exposure portion potential within the job are suppressed. It is possible to provide an electrophotographic photosensitive member that can stably obtain a high-quality image over a long period of time. In addition, according to the present invention, there is provided an image forming apparatus and a process cartridge capable of outputting an image with little change in image density and color, that is, excellent image quality consistency, by using the electrophotographic photosensitive member. can do.

DESCRIPTION OF SYMBOLS 1 Electrophotographic photoreceptor 5 Image exposure part 6 Developing unit 9 Recording medium 10 Photoconductor 18 Image forming means 21 Exposure means 25 Fixing means 60 Charging means 61 Developing means 74 Lubricating substance 75 Cleaning blade 76 Cleaning brush 101 Photoconductor 102 Charging means DESCRIPTION OF SYMBOLS 103 Exposure by exposure means 104 Developing means 105 Recording medium 106 Lubricating substance application means 107 Cleaning blade 108 Cleaning brush 109 Cleaning means 114 Cleaning brush 115 Cleaning blade 116 Lubricant application unit 117 Cleaning unit 121 Exposure light source 122 Photoconductor 130 Lubricant application Unit 156 Photosensitive drum 158 Intermediate transfer belt 160 Recording medium 162 Transfer conveyance belt 165 Fixing unit 120 Tandem development Stage 201 support 202 monolayer type photosensitive layer 203 a charge generation layer (CGL)
204 Charge transport layer (CTL)
205 Undercoat layer 206 Surface layer 207 Photosensitive layer L Exposure

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 Laid-Open No. 7-72640 JP-A-5-216249 JP 2003-98711 A JP 2002-341571 A JP 2005-99688 A JP 2000-162881 A

Claims (4)

An electrophotographic photosensitive member; a charging unit that charges the surface of the electrophotographic photosensitive member; an exposing unit that exposes the surface of the charged electrophotographic photosensitive member to form an electrostatic latent image; and And developing means for forming a visible image by developing, a transfer means for transferring the visible image to a recording medium, and a lubricating substance applying means for applying a lubricating substance to the surface of the electrophotographic photosensitive member. An image forming apparatus,
The lubricating substance is at least one selected from zinc stearate, aluminum stearate, and calcium stearate;
The electrophotographic photoreceptor has a support and at least a photosensitive layer on the support,
The surface layer of the photosensitive layer contains at least a filler and an aromatic hydrocarbon, and is measured by thermal extraction gas chromatograph mass spectrometry under extraction conditions of an extraction temperature of 230 ° C. for 15 minutes and a cryotrap temperature of −190 ° C. for 15 minutes. Ri the content of the aromatic hydrocarbons in the light-sensitive layer is 105 mass ppm~2,415 mass ppm der that,
It said surface layer, the image forming apparatus, wherein the tri- or more functional radical polymerizing monomer having no charge transport, that you containing a cured product of the radically polymerizable compound having a charge transport structure.   The image forming apparatus according to claim 1, wherein the aromatic hydrocarbon is at least one selected from benzene, toluene, and xylene. The image forming apparatus according to claim 1, wherein the surface layer contains a binder resin and a compound having a charge transporting structure. 4. The image forming apparatus according to claim 1, wherein the supply amount of the lubricating substance to the surface of the electrophotographic photosensitive member is 5 mg to 100 mg per 1,000 revolutions of the electrophotographic photosensitive member.