JP5553222B2 - Electrophotographic photosensitive member, electrophotographic method using the same, electrophotographic apparatus and process cartridge - Google Patents

Description

  The present invention relates to an electrophotographic photosensitive member containing a specific charge transport material and a specific amine compound, an electrophotographic method using the electrophotographic photosensitive member, an electrophotographic apparatus, and an electrophotographic process cartridge.

An electrophotographic photoreceptor (hereinafter sometimes referred to as “photoreceptor”) has a function of holding surface charges in the dark, a function of receiving light to generate charges, and a function of receiving light to transport charges. A so-called single-layer type photoreceptor that combines these functions in one layer, a layer that contributes mainly to charge generation, a surface charge in the dark, and a charge transport during photoreception. There is a so-called function-separated laminated type photoreceptor in which a function-separated layer is laminated with a layer to be functioned.
For example, a Carlson method is applied to image formation by electrophotography using these photoreceptors. Image formation by this method is performed by charging a photoconductor in a dark place by corona discharge, forming an electrostatic latent image such as text or a picture of an original on the surface of the charged photoconductor, The image is developed with toner, and the developed toner image is fixed on a support such as paper. After the toner image is transferred, the photoreceptor is subjected to charge removal, residual toner removal, light charge removal, etc., and then reused. Provided.

  In recent years, electrophotographic photoreceptors using organic substances have been put into practical use due to advantages such as flexibility, thermal stability, and film formability. Recently, a function-separated laminated type photoconductor comprising a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material as the photosensitive layer has become the mainstream, and in particular, an organic pigment is deposited as a charge generation material Many negatively charged photoreceptors have been proposed in which a layer or a layer dispersed in a resin is used as a charge generation layer, and an organic low molecular weight compound is used as a charge transport material and a layer dispersed in a resin is used as a charge transport layer.

  Organic materials have many advantages not found in inorganic materials, but at the same time, organic materials that sufficiently satisfy all the characteristics required for electrophotographic photoreceptors have not been obtained. That is, image quality is deteriorated due to a decrease in charging potential, an increase in residual potential, a change in sensitivity, and the like due to repeated use. Although not all of the causes of this deterioration have been elucidated, as one of the factors, oxidizing gases such as ozone and NOx released from corona discharge chargers, and oxidizing gases such as ozone and NOx in the atmosphere Has been found to cause significant damage to the photosensitive layer. In other words, these oxidizing gases cause various changes in properties by causing a chemical change with the material in the photoreceptor or by forming an adsorbate on the surface of the photosensitive layer. Causes increase in potential and decrease in resolution (image blur) due to decrease in surface resistance. As a result, the image quality is remarkably deteriorated and the life of the photoreceptor is shortened. As a countermeasure against these problems, proposals have been made to prevent deterioration by adding an antioxidant or a stabilizer to the photosensitive layer. For example, as represented by Patent Document 1, many additions of hindered phenol-based antioxidants and hindered amine-based antioxidants have been proposed. In addition, Patent Documents 2 to 7 can be cited as examples of addition of amine derivatives. These proposals had a certain effect.

In recent years, high wear resistance has been imparted by methods such as applying a lubricant to the surface of the photoconductor or providing a surface protective layer, and wear on the photoconductor has been suppressed by the process design around the photoconductor. Can be used for a long time. For this reason, it has become very important to improve the electrostatic characteristics of the photoconductor, but in order to maintain high image quality over a long period of time, addition of a conventional antioxidant or the like has become insufficient.
Recently, full-color and high-speed electrophotographic apparatuses are rapidly progressing, and accordingly, demand is diversified from a general office area to a SOHO area or a light printing area. In particular, in the light printing field, the printing volume is remarkably increased and the demand for image quality stability is increased. Therefore, it is indispensable to further increase the durability and stability of the organic photoreceptor.

  The problem of the exposure part potential fluctuation in the electrophotographic apparatus used in the light printing field is that the printing is started and one job is completed 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 fluctuations in the exposure part potential, the effect is not noticeable and the potential can be corrected in the apparatus. Therefore, the problem is not so great, but if the fluctuation in the job is large, the influence is conspicuous. If the potential fluctuates by several tens or several sheets in the job, it becomes difficult to correct the potential, which is a serious problem.

In particular, in the light printing field, there is a demand for printing a large amount of the same image pattern with one job. In this case, if the fluctuation in the exposure portion potential in the job is large, the image density changes and the image quality consistency is lowered. become. 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 suppress not only the daily fluctuation but also the intra-job fluctuation in the exposure portion potential fluctuation in the long-term repeated printing.
Further, in the light printing field where a high quality image is required, there may be a claim even if the reduction in resolution (image blur) due to an oxidizing gas such as NOx is slight deterioration.

  An object of the present invention is to improve resistance to oxidizing gases such as NOx in repeated use over a long period of time, have high durability, suppress image deterioration due to image density reduction or image blurring, and exposure. An object of the present invention is to provide an electrophotographic photosensitive member that suppresses not only the daily fluctuation of the partial potential but also the fluctuation in the job and can stably obtain a high-quality image. It is an object of the present invention to provide a highly durable and highly stable electrophotographic method, an electrophotographic apparatus, and a process cartridge for an electrophotographic apparatus, in which the image density is always stable and the image quality is consistent by using these photoconductors.

In order to solve the above problems, the electrophotographic photoreceptor according to the present invention, the electrophotographic method using the electrophotographic photoreceptor, the electrophotographic apparatus, and the process cartridge for the electrophotographic apparatus are specifically described in the following (1) to (1) to It has the technical features described in (8).
(1) “In an electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, the photosensitive layer is represented by the following general formula (1) and a charge transport material represented by the following general formula (1): An electrophotographic photoreceptor comprising an amine compound;

（式中、Ａｒ４及びＡｒ５は置換基を有してもよいアリ−ル基を示し、Ｒ４及びＲ５は置換基を有してもよいアルキル基、アラルキル基またはアリ−ル基を示し、Ｒ６は水素原子、置換基を有してもよいアルキル基、アルコキシ基あるいは水酸基またはハロゲン原子を示す。）

(In the formula, Ar 4 and Ar 5 represent an aryl group which may have a substituent, R 4 and R 5 represent an alkyl group, an aralkyl group or an aryl group which may have a substituent, and R 6 represents A hydrogen atom, an alkyl group, an alkoxy group, a hydroxyl group or a halogen atom which may have a substituent.

（ただし、式中、Ａ、Ｂはそれぞれ下記ｉ）、ii）より選ばれ、同一であっても、異なってもよい。
ｉ）−ＣＨ_２Ｘ
ii）−ＣＨ_２ＣＨ_２Ｙ
ただし、Ｘ，Ｙはそれぞれ芳香族残基、シクロアルキル基、またはヘテロシクロアルキル基を表し、これらは置換基を有してもよい。）」；

(However, in the formula, A and B are respectively selected from the following i) and ii), and may be the same or different.
i) _-CH 2 X
_ii) -CH 2 _CH 2 Y
However, X and Y each represent an aromatic residue, a cycloalkyl group, or a heterocycloalkyl group, and these may have a substituent. ) ”;

(2) “Charging step for charging the surface of the electrophotographic photosensitive member according to (1), an image exposure step for forming an electrostatic latent image on the electrophotographic photosensitive member, and developing the electrostatic latent image An electrophotographic method characterized by repeatedly performing a developing step for forming a toner image and a transfer step for transferring the toner image directly to a recording material or to a recording material via an intermediate transfer member;
(3) “Charging step for charging the surface of the electrophotographic photosensitive member according to (1), an image exposure step for forming an electrostatic latent image on the electrophotographic photosensitive member, and developing the electrostatic latent image Then, a development process for forming a toner image and a transfer process for transferring the toner image directly to a recording material or to a recording material via an intermediate transfer member are repeated, and the image exposure process is performed by the LD or LED. A digital electrophotographic method characterized by forming an electrostatic latent image. ";
(4) "The electrophotographic photosensitive member according to (1), a charging unit for charging the surface of the electrophotographic photosensitive member, an image exposing unit for forming an electrostatic latent image on the surface of the electrophotographic photosensitive member, An electrophotographic apparatus comprising: a developing unit that develops the electrostatic latent image to form a toner image; and a transfer unit that transfers the toner image directly to a recording material or an intermediate transfer member. ;
(5) "The electrophotographic photosensitive member according to (1), a charging unit for charging the surface of the electrophotographic photosensitive member, an image exposing unit for forming an electrostatic latent image on the surface of the electrophotographic photosensitive member, A developing unit that develops the electrostatic latent image to form a toner image; and a transfer unit that directly transfers the toner image to a recording material or an intermediate transfer member. The image exposing unit includes an LD or an LED. A digital type electrophotographic apparatus characterized by
(6) The electron according to (4) or (5), wherein the electron is a tandem type having a plurality of the electrophotographic photosensitive member, the charging unit, the developing unit, and the transfer unit. Photo equipment ";
(7) “An intermediate transfer member and an intermediate transfer unit are further included, and the transfer unit performs primary transfer of the toner image formed on the electrophotographic photosensitive member to the intermediate transfer member. The intermediate transfer means secondarily transfers the image on the intermediate transfer body onto the recording material, and when the image on the intermediate transfer body is a color image made of a plurality of colors of toner, The transfer unit forms an image on the intermediate transfer member by sequentially superimposing colors on the intermediate transfer member, and the intermediate transfer unit performs secondary transfer of the images on the intermediate transfer onto the recording material at once. The electrophotographic apparatus according to any one of (4) to (6), wherein:
(8) “The electrophotographic photosensitive member according to (1), a charging unit for charging the surface of the electrophotographic photosensitive member, an image exposing unit for forming an electrostatic latent image on the surface of the electrophotographic photosensitive member, the static Selected from developing means for developing an electrostatic latent image to form a toner image, cleaning means for cleaning the surface of the electrophotographic photosensitive member, and transfer means for directly transferring the toner image to a recording material or transferring it to an intermediate transfer member A process cartridge for an electrophotographic apparatus, comprising:

According to the present invention, resistance to oxidizing gases such as NOx is improved even for long-term repeated use, the photoreceptor characteristics are stabilized, and fluctuations in the job are also suppressed, and high-quality images are stable over a long period of time. An electrophotographic photosensitive member obtained as described above can be provided.
Further, according to the present invention, an electrophotographic method, an electrophotographic apparatus, and an electrophotographic apparatus 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. A process cartridge is provided.

FIG. 3 is a cross-sectional view illustrating a configuration example of an electrophotographic photosensitive member of the present invention. It is sectional drawing which shows another structural example of the electrophotographic photoreceptor of this invention. It is sectional drawing showing another structure of this invention. It is sectional drawing showing another structure of this invention. It is the schematic for demonstrating the example of the electrophotographic apparatus of this invention, and the example of an electrophotographic method. It is the schematic which shows the structure in 2nd Embodiment of the electrophotographic apparatus which concerns on this invention. It is the schematic which shows the structure in 3rd Embodiment of the electrophotographic apparatus which concerns on this invention. It is the schematic which shows the structure in 4th Embodiment of the electrophotographic apparatus which concerns on this invention. It is the schematic which shows the structure of one Embodiment of the process cartridge which concerns on this invention. 2 is a powder XD spectrum chart of titanyl phthalocyanine used as a charge generating material of the electrophotographic photosensitive member described in Examples.

Hereinafter, the configuration of the electrophotographic photosensitive member of the present invention will be described with reference to the drawings.
As described above, FIG. 1 is a sectional view showing the structure of the electrophotographic photosensitive member of the present invention. On the conductive support (31), a photosensitive layer (mainly composed of a charge generating substance and a charge transporting substance) 33).
FIG. 2 is a cross-sectional view showing another structural example of the electrophotographic photosensitive member of the present invention. On the conductive support (31), a charge generation layer (35) mainly composed of a charge generation material, and a charge The charge transport layer (37) mainly composed of a transport material has a laminated structure.
FIG. 3 is a cross-sectional view showing still another configuration of the present invention, in which a photosensitive layer (33) mainly composed of a charge generation material and a charge transport material is provided on a conductive support (31). A protective layer (39) is provided on the surface of the photosensitive layer. In this case, the protective layer (39) may contain the amine compound of the general formula (2).
FIG. 4 is a cross-sectional view showing still another configuration of the present invention. On a conductive support (31), a charge generation layer (35) containing a charge generation material as a main component and a charge transport material as a main component. The charge transport layer (37) is laminated, and a protective layer (39) is further provided on the charge transport layer. In this case, the protective layer (39) may contain the amine compound of the general formula (2).

As the conductive support (31), a material having a volume resistance of 10 ¹⁰ Ω · cm or less, for example, a metal such as aluminum, nickel, chromium, nichrome, copper, gold, silver, platinum, tin oxide, oxidation Metal oxide such as indium by vapor deposition or sputtering, film or cylindrical plastic, paper coated, or aluminum, aluminum alloy, nickel, stainless steel plates, etc. and methods such as extrusion and drawing After forming the tube, it is possible to use a tube subjected to surface treatment such as cutting, superfinishing or polishing. Further, an endless nickel belt and an endless stainless steel belt disclosed in Japanese Patent Application Laid-Open No. 52-36016 can be used as the conductive support (31).

  In addition, the conductive support dispersed in a suitable binder resin and coated on the support can also be used as the conductive support (31) of the present invention. Examples of the conductive powder include carbon black, acetylene black, metal powder such as aluminum, nickel, iron, nichrome, copper, zinc and silver, or metal oxide powder such as conductive tin oxide and ITO. It is done. The binder resin used at the same time is polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer. , Polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, Examples thereof include thermoplastic, thermosetting resins, and photocurable resins such as melamine resin, urethane resin, phenol resin, and alkyd resin. Such a conductive layer can be provided by dispersing and coating these conductive powder and binder resin in a suitable solvent such as tetrahydrofuran, dichloromethane, methyl ethyl ketone, and toluene.

  Furthermore, it is electrically conductive by a heat-shrinkable tube in which the conductive powder is contained in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, Teflon (registered trademark) on a suitable cylindrical substrate. Those provided with a conductive layer can also be used favorably as the conductive support (31) of the present invention.

Next, the photosensitive layer will be described. The photosensitive layer may be a single layer photosensitive layer (FIGS. 1 and 3) including a charge generation material and a charge transport material, or may be a laminated type (FIGS. 2 and 4) including a charge generation layer and a charge transport layer. However, for convenience of explanation, the photosensitive layer having a laminated structure will be described first.
The charge generation layer (35) is a layer mainly composed of a charge generation material. A known charge generation material can be used for the charge generation layer (35), and representative examples thereof include a monoazo pigment, a disazo pigment, a trisazo pigment, a perylene pigment, a perinone pigment, a quinacridone pigment, and a quinone condensation. Examples thereof include polycyclic compounds, squaric acid dyes, other phthalocyanine pigments, naphthalocyanine pigments, and azulenium salt dyes. These charge generation materials may be used alone or in combination of two or more.

In the charge generation layer (35), the charge generation material is dispersed in a suitable solvent together with a binder resin, if necessary, using a ball mill, attritor, sand mill, ultrasonic wave, etc., and this is applied onto a conductive support. And formed by drying.
The binder resin used as necessary includes polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, polysulfone, poly-N-vinylcarbazole, poly Examples include acrylamide, polyvinyl benzal, polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyamide, polyvinyl pyridine, cellulosic resin, casein, polyvinyl alcohol, and polyvinyl pyrrolidone. The amount of the binder resin is suitably 0 to 500 parts by weight, preferably 10 to 300 parts by weight with respect to 100 parts by weight of the charge generating material. The binder resin may be added before or after dispersion.

Examples of the solvent include isopropanol, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane, monochlorobenzene, cyclohexane, toluene, xylene, ligroin, etc. , Ester solvents and ether solvents are preferably used. These may be used alone or in combination of two or more.
The charge generation layer (35) is mainly composed of a charge generation material, a solvent, and a binder resin, but may contain various additives such as a sensitizer, a dispersant, a surfactant, and silicone oil. .
As a coating method for the coating solution, a dip coating method, spray coating, beat coating, nozzle coating, spinner coating, ring coating, or the like can be used.
The film thickness of the charge generation layer (35) is suitably about 0.01 to 5 μm, preferably 0.1 to 2 μm.

  The charge transport layer (37) is a layer mainly composed of a charge transport material, and in the present invention, contains a charge transport material represented by the general formula (1) and an amine compound represented by the general formula (2). To do.

（式中、Ａｒ４及びＡｒ５は置換基を有してもよいアリ−ル基を示し、Ｒ４及びＲ５は置換基を有してもよいアルキル基、アラルキル基またはアリ−ル基を示し、Ｒ６は水素原子、置換基を有してもよいアルキル基、アルコキシ基あるいは水酸基またはハロゲン原子を示す。）

(In the formula, Ar 4 and Ar 5 represent an aryl group which may have a substituent, R 4 and R 5 represent an alkyl group, an aralkyl group or an aryl group which may have a substituent, and R 6 represents A hydrogen atom, an alkyl group, an alkoxy group, a hydroxyl group or a halogen atom which may have a substituent.

In the general formula (1), examples of the aryl group include phenyl and naphthyl groups, and examples of the alkyl group, aralkyl group, and halogen atom include the same groups as in the general formula (1). Includes an alkyl group such as methyl and ethyl, an alkoxy group such as methoxy and ethoxy, an aryl group such as phenyl and naphthyl, a halogen atom such as a fluorine atom, a chlorine atom and a bromine atom, or a hydroxyl group.
Preferred examples of the charge transport material represented by the general formula (1) are given below. However, the present invention is not limited to these compounds.

（ただし、式中、Ａ、Ｂはそれぞれ下記ｉ）ii）より選ばれ、同一であっても、異なってもよい。
ｉ）−ＣＨ_２Ｘ
ii）−ＣＨ_２ＣＨ_２Ｙ
ただし、Ｘ，Ｙはそれぞれ芳香族残基、シクロアルキル基、またはヘテロシクロアルキル基を表し、これらは置換基を有してもよい。）
以下に一般式（２）で表されるアミン化合物の好ましい例を挙げる。但し、本発明は、これらの化合物に限定されるわけではない。

(However, in the formula, A and B are each selected from the following i) ii) and may be the same or different.
i) _-CH 2 X
_ii) -CH 2 _CH 2 Y
However, X and Y each represent an aromatic residue, a cycloalkyl group, or a heterocycloalkyl group, and these may have a substituent. )
Preferred examples of the amine compound represented by the general formula (2) are given below. However, the present invention is not limited to these compounds.

In the present invention, by combining the charge transport material represented by the general formula (1) and the amine compound represented by the general formula (2), resistance to oxidizing gas such as NOx even for long-term repeated use. Is improved, electrostatic characteristics are stabilized, and fluctuations in the job can also be reduced.
Although these causes are not clear, one reason is that the amine compound represented by the general formula (2) has excellent gas resistance. This is presumably because the amine compound represented by the general formula (2) has a strong basic amino group, which can prevent the charge transport material from being altered by the oxidizing gas. In addition, unlike antioxidants, they do not have polar groups that easily trap charges, and they themselves have charge transport properties, so even if they are added in relatively large amounts, they have the effect of increasing the exposed area potential and residual potential. Is estimated to be reduced.
Furthermore, it is presumed that the amine compound represented by the general formula (2) has a specific influence on the charge transport function with respect to the charge transport material represented by the general formula (1). Due to the excellent gas resistance of the amine compound, it suppresses the deterioration of the charge transport material due to the oxidizing gas such as ozone and NOx generated by the corona charger in the apparatus, and further has less influence on the charge transport function. The electrostatic characteristics can be stabilized even after repeated use, and fluctuations in the job can be reduced.

  The content of the charge transport material represented by the general formula (1) in the charge transport layer (37) is preferably 30 to 200 parts by weight with respect to 100 parts by weight of the binder resin. If the content of the charge transport material represented by the general formula (1) is less than 30 parts by weight, the electrical characteristics deteriorate, for example, the residual potential increases. On the other hand, when the amount is more than 200 parts by weight, mechanical properties such as wear resistance are lowered.

  Furthermore, the charge transport material represented by the general formula (1) and other charge transport materials can be mixed and used. In this case, the content ratio of the charge transport material represented by the general formula (1) and the other charge transport material is (charge transport material represented by the general formula (I)): (other charge transport material) = The range of 50:50 to 95: 5 is preferable, and the range of 70:30 to 95: 5 is more preferable.

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

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

  In addition, the content of the amine compound represented by the general formula (2) in the charge transport layer (37) is preferably 1 to 30 parts by weight of the amine compound with respect to 100 parts by weight of the charge transport material. When the content of this compound is less than 1 part by weight, the decrease in charging and the image blur due to the effects of ozone and NOx are remarkable. On the other hand, when the content is more than 30 parts by weight, the increase in the residual potential due to repeated use increases. .

  As the binder resin constituting the charge transport layer, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer Copolymer, polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin And thermoplastic or thermosetting resins such as melamine resin, urethane resin, phenol resin, and alkyd resin.

  The film thickness of the charge transport layer is preferably 50 μm or less, and preferably 25 μm or less from the viewpoint of resolution and responsiveness. The lower limit varies depending on the system to be used (particularly charging potential), but is preferably 5 μm or more.

As the solvent, tetrahydrofuran, dioxane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, methyl ethyl ketone, acetone and the like are used. These may be used alone or in combination of two or more.
As a coating method of the coating solution, a conventional coating method such as dip coating, spray coating, beat coating, nozzle coating, spinner coating, ring coating, or the like can be used.

Next, the case where the photosensitive layer has a single layer structure (in the case of FIGS. 1 and 3) will be described.
The photosensitive layer (33) can be formed by dissolving or dispersing a charge generation material, a charge transport material and a binder resin in a suitable solvent, and applying and drying the solution. The photosensitive layer (33) contains a charge transport material represented by the general formula (1) and an amine compound represented by the general formula (2). Moreover, a plasticizer, a leveling agent, antioxidant, etc. can also be added as needed.

In the single-layer type photosensitive layer (33), the materials (charge generation material, charge transport material, binder resin) used for the photosensitive layer (charge generation layer, charge transport layer) having the above-described laminated structure are similarly used. Can do.
In the case of the photosensitive layer (33) having a single layer structure, it is preferable to use the above-described electron transporting material in combination as a charge transporting material for high sensitivity.

In the photosensitive layer (33) having a single layer structure, the charge generating material is 0.1 to 30% by weight, preferably 0.5 to 5% by weight, based on the entire photosensitive layer. When the concentration of the charge generating substance is low, the photoreceptor sensitivity tends to decrease, and when the concentration is high, the chargeability and the film strength tend to decrease.
The content of the charge transport material represented by the general formula (1) is preferably 30 to 200 parts by weight with respect to 100 parts by weight of the binder resin. The content of the electron transport material is preferably 30 to 200 parts by weight with respect to 100 parts by weight of the binder resin.
Moreover, it is preferable that content of the amine compound represented by the said General formula (2) shall be 1-30 weight part of amine compounds with respect to 100 weight part of charge transport substances.

  The film thickness of the photosensitive layer is preferably 50 μm or less, and preferably 25 μm or less from the viewpoint of resolution and responsiveness. The lower limit varies depending on the system to be used (particularly charging potential), but is preferably 5 μm or more.

  In the photoreceptor of the present invention, an undercoat layer (not shown) can be provided between the conductive support (31) and the photosensitive layer. In general, the undercoat layer is mainly composed of a resin. However, considering that the photosensitive layer is coated with a solvent on these resins, it is desirable that the resin be a resin having a high solvent resistance with respect to a general organic solvent. . Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane, melamine resin, phenol resin, alkyd-melamine resin, and epoxy. Examples thereof include a curable resin that forms a three-dimensional network structure such as a resin. Further, fine powder pigments of metal oxides such as titanium oxide, silica, alumina, zirconium oxide, tin oxide, and indium oxide may be added to the undercoat layer in order to prevent moire and reduce residual potential.

  These undercoat layers can be formed using an appropriate solvent and a coating method like the above-mentioned photosensitive layer. In addition, as the undercoat layer of the present invention, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can be used, or Al2O3 is provided by anodization, such as polyparaxylylene (parylene). An organic material or an inorganic material such as SiO 2, SnO 2, TiO 2, ITO, or CeO 2 provided by a vacuum thin film forming method can also be used favorably. Further, other known ones can also be used. The thickness of the undercoat layer is suitably from 0 to 5 μm.

  In the photoreceptor of the present invention, a protective layer (39) may be provided on the photosensitive layer for the purpose of protecting the photosensitive layer. Materials used for the protective layer (39) include ABS resin, ACS resin, olefin-vinyl monomer copolymer, chlorinated polyether, aryl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallylsulfone. , Polybutylene, polybutylene terephthalate, polycarbonate, polyethersulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylbenten, polypropylene, polyphenylene oxide, polysulfone, polystyrene, polyarylate, AS resin, butadiene-styrene copolymer, polyurethane , Resins such as polyvinyl chloride, polyvinylidene chloride, and epoxy resin. From the viewpoint of filler dispersibility, residual potential, and coating film defects, polycarbonate or polyarylate is particularly effective and useful.

  In addition, a filler material can be added to the protective layer of the photoreceptor for the purpose of improving the wear resistance. As the solvent to be used, all solvents used in the charge transport layer 37 such as tetrahydrofuran, dioxane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, methyl ethyl ketone, and acetone can be used. However, a solvent having a high viscosity is preferable at the time of dispersion, but a solvent having high volatility is preferable at the time of coating. When there is no solvent satisfying these conditions, it is possible to use a mixture of two or more solvents having respective physical properties, which may have a great effect on filler dispersibility and residual potential. .

  Moreover, the amine compound represented by General formula (2) may be contained in the protective layer. Furthermore, the addition of the charge transport material mentioned in the charge transport layer (37) is effective and useful for reducing the residual potential and improving the image quality.

  As a method for forming the protective layer, conventional methods such as dip coating, spray coating, beat coating, nozzle coating, spinner coating, ring coating, etc. can be used. preferable.

  In the photoreceptor of the present invention, an intermediate layer can be provided between the photosensitive layer and the protective layer. In the intermediate layer, a binder resin is generally used as a main component. Examples of these resins include polyamide, alcohol-soluble nylon, water-soluble polyvinyl butyral, polyvinyl butyral, and polyvinyl alcohol. As a method for forming the intermediate layer, a generally used coating method as described above is employed. In addition, about 0.05-2 micrometers is suitable for the thickness of an intermediate | middle layer.

  In the present invention, in order to improve environmental resistance, in order to prevent a decrease in sensitivity and an increase in residual potential, oxidation is performed on each layer such as a charge generation layer, a charge transport layer, an undercoat layer, a protective layer, and an intermediate layer. Inhibitors, plasticizers, lubricants, UV absorbers and leveling agents can be added. Representative materials of these compounds are described below.

Examples of the antioxidant that can be added to each layer include, but are not limited to, the following.
(A) Phenolic compounds 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, n-octadecyl -3- (4'-hydroxy-3 ', 5'-di-tert-butylphenol), 2,2'-methylene-bis- (4-methyl-6-tert-butylphenol), 2,2'- Methylene-bis- (4-ethyl-6-tert-butylphenol), 4,4′-thiobis- (3-methyl-6-tert-butylphenol), 4,4′-butylidenebis- (3-methyl) -6-tert-butylphenol), 1,1,3-tris- (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6- Tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, te Lakis- [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane, bis [3,3′-bis (4′-hydroxy-3′-t) -Butylphenyl) butyric acid] cricol ester, tocopherols and the like.

(B) Paraphenylenediamines N-phenyl-N′-isopropyl-p-phenylenediamine, N, N′-di-sec-butyl-p-phenylenediamine, N-phenyl-N-sec-butyl-p-phenylene Diamine, N, N′-di-isopropyl-p-phenylenediamine, N, N′-dimethyl-N, N′-di-t-butyl-p-phenylenediamine and the like.

(C) Hydroquinones 2,5-di-t-octylhydroquinone, 2,6-didodecylhydroquinone, 2-dodecylhydroquinone, 2-dodecyl-5-chlorohydroquinone, 2-t-octyl-5-methylhydroquinone, 2 -(2-octadecenyl) -5-methylhydroquinone and the like.
(D) Organic sulfur compounds Dilauryl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, ditetradecyl-3,3′-thiodipropionate, and the like.

(E) Organic phosphorus compounds Triphenylphosphine, tri (nonylphenyl) phosphine, tri (dinonylphenyl) phosphine, tricresylphosphine, tri (2,4-dibutylphenoxy) phosphine and the like.
Examples of the plasticizer that can be added to each layer include, but are not limited to, the following.
(A) Phosphate ester plasticizer Triphenyl phosphate, tricresyl phosphate, trioctyl phosphate, octyl diphenyl phosphate, trichloroethyl phosphate, cresyl diphenyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, Triphenyl phosphate etc.

(B) Phthalate ester plasticizers Dimethyl phthalate, diethyl phthalate, diisobutyl phthalate, dibutyl phthalate, diheptyl phthalate, di-2-ethylhexyl phthalate, diisooctyl phthalate, di-n-octyl phthalate, phthalate Dinonyl acid, diisononyl phthalate, diisodecyl phthalate, diundecyl phthalate, ditridecyl phthalate, dicyclohexyl phthalate, butyl benzyl phthalate, butyl lauryl phthalate, methyl oleyl phthalate, octyl decyl phthalate, dibutyl fumarate, dioctyl fumarate Such.

(C) Aromatic carboxylic acid ester plasticizers Trioctyl trimellitic acid, tri-n-octyl trimellitic acid, octyl oxybenzoate, and the like.

(D) Aliphatic dibasic ester plasticizer dibutyl adipate, di-n-hexyl adipate, di-2-ethylhexyl adipate, di-n-octyl adipate, adipic acid n-octyl-n-decyl , Diisodecyl adipate, dicapryl adipate, di-2-ethylhexyl azelate, dimethyl sebacate, diethyl sebacate, dibutyl sebacate, di-n-octyl sebacate, di-2-ethylhexyl sebacate, di-2 sebacate -Ethoxyethyl, dioctyl succinate, diisodecyl succinate, dioctyl tetrahydrophthalate, di-n-octyl tetrahydrophthalate and the like.

(E) Fatty acid ester derivatives butyl oleate, glycerin monooleate, methyl acetylricinoleate, pentaerythritol ester, dipentaerythritol hexaester, triacetin, tributyrin and the like.

(F) Oxyacid ester plasticizers Methyl acetyl ricinoleate, butyl acetyl ricinoleate, butyl phthalyl butyl glycolate, tributyl acetyl citrate and the like.

(G) Epoxy plasticizer Epoxidized soybean oil, epoxidized linseed oil, butyl epoxy stearate, decyl epoxy stearate, octyl epoxy stearate, benzyl epoxy stearate, dioctyl epoxy hexahydrophthalate, didecyl epoxy hexahydrophthalate, etc. .

(H) Dihydric alcohol ester plasticizers such as diethylene glycol dibenzoate and triethylene glycol di-2-ethylbutyrate.

(I) Chlorinated plasticizer Chlorinated paraffin, chlorinated diphenyl, chlorinated fatty acid methyl, methoxychlorinated fatty acid methyl and the like.

(J) Polyester plasticizer Polypropylene adipate, polypropylene sebacate, polyester, acetylated polyester and the like.

(K) Sulfonic acid derivatives p-toluenesulfonamide, o-toluenesulfonamide, p-toluenesulfoneethylamide, o-toluenesulfoneethylamide, toluenesulfone-N-ethylamide, p-toluenesulfone-N-cyclohexylamide and the like.

(L) Citric acid derivatives Triethyl citrate, triethyl acetylcitrate, tributyl citrate, tributyl acetylcitrate, tri-2-ethylhexyl acetylcitrate, acetylcitrate-n-octyldecyl, and the like.

(M) Others Terphenyl, partially hydrogenated terphenyl, camphor, 2-nitrodiphenyl, dinonylnaphthalene, methyl abietate and the like.

Examples of the lubricant that can be added to each layer include, but are not limited to, the following.
(A) Hydrocarbon compounds Liquid paraffin, paraffin wax, microwax, low-polymerized polyethylene and the like.

(B) Fatty acid compounds Lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid and the like.
(C) Fatty acid amide compounds Stearylamide, palmitylamide, oleinamide, methylenebisstearamide, ethylenebisstearamide and the like.
(D) Ester compounds Lower alcohol esters of fatty acids, polyhydric alcohol esters of fatty acids, fatty acid polyglycol esters, and the like.
(E) Alcohol compounds Cetyl alcohol, stearyl alcohol, ethylene glycol, polyethylene glycol, polyglycerol and the like.

(F) Metal soap Lead stearate, cadmium stearate, barium stearate, calcium stearate, zinc stearate, magnesium stearate and the like.

(G) Natural wax Carnauba wax, candelilla wax, beeswax, whale wax, ivotaro, montan wax and the like.

(H) Others Silicone compounds, fluorine compounds, etc.

Examples of the ultraviolet absorber that can be added to each layer include, but are not limited to, the following.
(A) Benzophenone series 2-hydroxybenzophenone, 2,4-dihydroxybenzophenone, 2,2 ′, 4-trihydroxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2,2′-dihydroxy-4- Such as methoxybenzophenone.
(B) Salsylate type Phenyl salsylate, 2,4-di-t-butylphenyl-3,5-di-t-butyl-4-hydroxybenzoate, and the like.
(C) benzotriazole (2′-hydroxyphenyl) benzotriazole, (2′-hydroxy5′-methylphenyl) benzotriazole, (2′-hydroxy5′-methylphenyl) benzotriazole, (2′-hydroxy3) '-Tertiarybutyl 5'-methylphenyl) 5-chlorobenzotriazole and the like.
(D) Cyanoacrylate-based ethyl-2-cyano-3,3-diphenyl acrylate, methyl 2-carbomethoxy-3- (paramethoxy) acrylate, and the like.
(E) Quencher (metal complex)
Nickel (2,2′thiobis (4-t-octyl) phenolate) normal butylamine, nickel dibutyldithiocarbamate, nickel dibutyldithiocarbamate, cobalt dicyclohexyldithiophosphate and the like.

(F) HALS (hindered amine)
Bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1- [2- [3- (3 5-di-t-butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6 6-tetramethylpyridine, 8-benzyl-7,7,9,9-tetramethyl-3-octyl-1,3,8-triazaspiro [4,5] undecane-2,4-dione, 4-benzoyloxy- 2,2,6,6-tetramethylpiperidine and the like.

[Electrophotographic apparatus, electrophotographic method]
The electrophotographic apparatus according to the present invention includes the above-described electrophotographic photosensitive member, a charging unit that charges the surface of the electrophotographic photosensitive member, an image exposing unit that forms an electrostatic latent image on the surface of the electrophotographic photosensitive member, A developing unit that develops an electrostatic latent image to form a toner image; and a transfer unit that transfers the toner image to a recording material. The image forming apparatus further includes other units that are appropriately selected as necessary. Do it. Examples of other means include cleaning means, static elimination means, recycling means, and control means.

<First Embodiment>
Next, the electrophotographic apparatus and the electrophotographic method according to the present invention will be described in detail using specific examples with reference to the drawings.
FIG. 5 is a schematic diagram for explaining the electrophotographic apparatus and the electrophotographic method of the present invention, and is a schematic diagram showing the configuration of the electrophotographic apparatus according to the first embodiment of the present invention.
In FIG. 5, a photoreceptor (1) is the above-described electrophotographic photoreceptor according to the present invention. The photosensitive member (1) has a drum shape, but may be a sheet shape or an endless belt shape.
In the embodiment shown in FIG. 5, the drum-shaped photoconductor (1) is rotated counterclockwise in the drawing by a driving means (not shown) and electrophotographic using each means provided around the photoconductor (1). An image is formed. Hereinafter, description will be given in the order of each step of the electrophotographic method.

(Charging means, charging process)
First, the surface of the photoreceptor (1) is uniformly charged by a charging charger (3) as a charging means. The charging charger (3) may be appropriately selected from conventionally known ones depending on the characteristics of the photosensitive member (1) and the developing toner, and the surface of the photosensitive member (1) may have a predetermined polarity (positive charging or negative charging). Any one can be applied as long as it is charged to a predetermined potential. Examples of the charging charger (3) include a corotron, a scorotron, a solid state charger (solid state charger), a charging roller, and the like.

(Image exposure means, image exposure process)
Next, an electrostatic latent image is formed on the surface of the uniformly charged photoreceptor (1) by an image exposure unit (5) as image exposure means. As the image exposure unit (5), for example, fluorescent materials, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light emitting diodes (LEDs), semiconductor lasers (LD), electroluminescence (EL), etc. It is preferable to use a light emitting diode or a semiconductor laser. In order to irradiate only light in a desired wavelength range during image exposure, 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 are used. It can arrange | position between a photoconductor (1) and an image exposure part (5).

(Development means, development process)
The electrostatic latent image formed on the surface of the photoreceptor (1) is developed by a developing unit (6) as developing means using toner. That is, the electrostatic latent image is developed by the developing unit (6) to form a visible toner image. The developing unit (6) may be appropriately selected from conventionally known developing units according to the toner to be used. Examples of the developing unit (6) include a one-component developing method and a two-component developing method, and further, there are ones for magnetic toner and non-magnetic toner, respectively.

(Transfer means, transfer process)
Further, the toner image carried on the photoconductor (1) is conveyed to a transfer charger (10) as transfer means as the photoconductor (1) rotates. As the transfer charger (10), the same one as the above-mentioned charging charger (3) can be applied. However, as shown in FIG. 5, a combination of the transfer charger (10) and the separation charger (11) is used. It is effective.
Further, in order to improve transfer efficiency, a pre-transfer charger (7) may be provided upstream of the transfer charger (10) (relative to the rotation direction of the photosensitive member (1)) to precharge the toner image. preferable. As the transfer charger (7), the same one as the above-mentioned charging charger (3) can be applied.
On the other hand, at a position where the photoconductor (1) and the transfer charger (10) face each other, a transfer sheet (9) as a recording material is moved to a desired position on the transfer sheet (9) by a registration roller (8) or the like. The toner image is conveyed so as to be transferred.
The toner image is transferred to the transfer paper (9) by the transfer charger (10) at a position where the toner image on the photoreceptor (1) and the transfer paper (9) face each other.
The transfer paper (9) onto which the toner image has been transferred reaches the separation claw (12) by rotating with the photoreceptor (1), and the surface of the photoreceptor (1) is reached by the separation claw (12). The sheet is discharged from the electrophotographic apparatus through a transporting and fixing process, which is not described further.

(Cleaning means, cleaning process)
Here, the toner image that could not be transferred onto the transfer paper (9) on the surface of the photoreceptor (1) after transfer by the transfer charger (10) and separation of the transfer paper (9) by the separation claw (12). There are deposits such as so-called transfer residual toner and paper dust. For this reason, deposits are removed from the surface of the photoreceptor (1) by the fur brush (14) and the cleaning blade (15) which are cleaning means. As the cleaning means, in addition to the fur brush (14) and the cleaning blade (15), conventionally known ones such as a mag fur brush can be used. Further, only the fur brush or only the cleaning blade can be used. In order to improve the cleaning efficiency, it is preferable to precharge by the pre-cleaning charger (13) before being provided to the cleaning means. As the pre-cleaning charger (13), the same charger as the above-described charging charger (3) can be applied.

(Static elimination means, static elimination process)
The photosensitive member (1) from which the deposits have been removed from the surface by the cleaning means is further discharged by light irradiation of the charge removal lamp (2), which is a charge removal means, thereby completing a series of electrophotographic image forming processes. . By repeating this series of electrophotographic image forming processes, it is possible to form images on a plurality of recording materials.
As the charge eliminating means, a conventionally known one can be applied. For example, as the charge eliminating lamp (2), the same one as the above-described image exposure unit (5) can be applied.

In the image forming process by the series of electrophotographic methods described above, when the electrophotographic photosensitive member (1) is positively (negatively) charged and image exposure is performed, positive (negative) is formed on the surface of the photosensitive member (1). An electrostatic latent image is formed. A positive image can be obtained by developing this with negative (positive) toner (electrodetection fine particles), and a negative image can be obtained by developing with positive (negative) toner. The charging polarity of the electrophotographic photoreceptor (1) and the polarity of the toner used for development are arbitrary, and any may be used.
Further, the various light sources used in the image exposure unit (5) are not limited to being used in the form shown in FIG. 5, but are also a transfer process, a static elimination process, a cleaning process, combined with light irradiation, Or it can use for processes, such as pre-exposure.

<Second Embodiment>
FIG. 6 is a schematic diagram showing the configuration of the electrophotographic apparatus according to the second embodiment of the present invention.
The photoreceptor (21) has at least a photosensitive layer (not shown), is driven by driving rollers (22a) and (22b), and is charged by a charger (23) which is a charging unit, and is an image exposure unit. Image exposure by light source (24), development (not shown) as developing means, transfer using transfer charger (25) as transfer means, exposure before cleaning by light source (26), cleaning brush (27) as cleaning means Cleaning and neutralization by the light source (28), which is a neutralizing means, are repeated. In FIG. 6, the photoconductor (21) (of course, the support is translucent in this case) is irradiated with pre-cleaning exposure light from the conductive support (not shown) side.

The image forming process by the electrophotographic method performed using the electrophotographic apparatus shown in FIG. 6 exemplifies the embodiment in the present invention, and it goes without saying that other embodiments are possible. For example, in FIG. 6, the pre-cleaning exposure is performed from the conductive support (not displayed) side, but this may be performed from the photosensitive layer (not displayed) side. Irradiation may be performed from the conductive support side.
On the other hand, as the process of irradiating light, image exposure, pre-cleaning exposure, and static elimination exposure are illustrated, but in addition, there are provided pre-transfer exposure, pre-exposure of image exposure, and other known light irradiation processes. Thus, the photoconductor (21) can be irradiated with light.

<Third Embodiment>
Furthermore, an embodiment of an electrophotographic printer (hereinafter simply referred to as a printer) will be described as a full-color electrophotographic apparatus to which the present invention is applied.
FIG. 7 is a schematic view showing the configuration of the electrophotographic apparatus according to the third embodiment of the present invention.
In FIG. 7, a drum-shaped photoconductor (56) which is a latent image carrier is rotated by a counterclockwise rotation in the drawing, and the surface thereof is charged by a charging charger (53) which is a charging means using a corotron or a scorotron. After being uniformly charged, an electrostatic latent image is carried by scanning with a laser beam L emitted from a laser optical device which is an image exposure unit (not shown). 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 (56). An electrostatic latent image is formed. A revolver developing unit (50) is disposed on the left side of the photosensitive drum (56) in the drawing. This has a yellow developing device, a magenta developing device, a cyan developing device, and a black developing device as developing means in a rotating drum-shaped housing, and each developing device is turned into a photosensitive drum (56) by rotation. Move sequentially to opposite development positions. The yellow developer, magenta developer, cyan developer, and black developer are for developing an electrostatic latent image by attaching yellow toner, magenta toner, cyan toner, and black toner, respectively. On the photosensitive drum (56), electrostatic latent images for yellow, magenta, cyan, and black are sequentially formed, and these images are sequentially developed by the developing units of the revolver developing unit (50), so that a yellow toner image, magenta A toner 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 (56) from the development position. This includes an intermediate transfer belt (58) stretched by a stretch roller (59a), an intermediate transfer bias roller (57) as a transfer means, a secondary transfer backup roller (59b), and a belt drive roller (59c). The belt drive roller (59c) is driven to rotate endlessly in the clockwise direction in the drawing. The yellow toner image, magenta toner image, cyan toner image, and black toner image developed on the photosensitive drum (56) enter the intermediate transfer nip where the photosensitive drum (56) and the intermediate transfer belt (58) are in contact with each other. To do. While being affected by the bias from the intermediate transfer bias roller (57), the toner image is superimposed on the intermediate transfer belt (58) and intermediately transferred (primary transfer) to form a four-color superimposed toner image.

  The surface of the photosensitive drum (56) that has passed through the intermediate transfer nip with the rotation is cleaned of residual toner by a drum cleaning unit (55) that is a cleaning means. The drum cleaning unit (55) is for cleaning the transfer residual toner by a cleaning roller to which a cleaning bias is applied. The drum cleaning unit (55) uses a cleaning brush such as a fur brush or a mag fur brush, or a cleaning blade. Also good.

  The surface of the photosensitive drum (56) from which the transfer residual toner has been cleaned is discharged by a discharging lamp (54) which is a discharging means. As the charge removal lamp (54), a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), an electroluminescence (EL), or the like is used. A semiconductor laser is used as the light source of the laser optical device. About these emitted lights, you may make it use only a desired wavelength range by various filters, such as a sharp cut filter, a band pass filter, a near-infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter.

  On the other hand, the registration roller pair (61) sandwiching the transfer paper (60), which is a recording material sent from a paper feed cassette (not shown), between the two rollers, transfers the transfer paper (60) to the intermediate transfer belt (58). The sheet is fed toward the secondary transfer nip where the intermediate transfer belt (58) and the transfer belt (62) are in contact with each other at a timing at which the upper four-color superimposed toner image can be superimposed. The four-color superimposed toner image on the intermediate transfer belt (58) is affected by the secondary transfer bias from the paper transfer bias roller (63), which is a secondary transfer means, in the secondary transfer nip. ) Secondary transfer is performed at once. By this secondary transfer, a full color image is formed on the transfer paper (60). The transfer paper (60) on which the full-color image is formed is sent to the transport belt (64) by the transfer belt (62). The conveyor belt (64) feeds the transfer paper (60) received from the transfer unit into the fixing unit (65). The fixing unit (65) conveys the transferred transfer paper (60) while being sandwiched between fixing nips formed by contact between the heating roller and the backup roller. The full-color image on the transfer paper (60) is fixed on the transfer paper (60) under the influence of the heating from the heating roller and the pressure in the fixing nip.

  Although not shown, a bias for adsorbing the transfer paper (60) is applied to the transfer belt (62) and the conveyance belt (64). In addition, a paper neutralization charger that neutralizes the transfer paper (60) and three belt neutralization chargers that neutralize each belt (intermediate transfer belt (58), transfer belt (62), and conveyance belt (64)) are provided. Yes. The intermediate transfer unit also includes a belt cleaning unit having the same configuration as that of the drum cleaning unit (55), thereby cleaning the transfer residual toner on the intermediate transfer belt (58).

That is, the electrophotographic apparatus of the present invention includes an intermediate transfer unit in addition to the transfer unit that transfers to the intermediate transfer member, and the toner image formed on the electrophotographic photosensitive member by the transfer unit is transferred to the intermediate transfer unit. It is possible to adopt a configuration in which an image is formed on an intermediate transfer member by primary transfer to a medium, and the image on the intermediate transfer member is secondarily transferred onto the recording material by the intermediate transfer unit.
Here, when the image that is secondarily transferred onto the recording material is a color image composed of a plurality of colors of toner, the toner of each color is sequentially superimposed on the intermediate transfer member by the transfer means. An image can be formed on the body, and the image on the intermediate transfer body can be secondarily transferred collectively onto the recording material by the intermediate transfer unit.

<Fourth embodiment>
FIG. 8 is a schematic diagram showing the configuration of the electrophotographic apparatus according to the fourth embodiment of the present invention. The present embodiment is a tandem type electrophotographic apparatus having an intermediate transfer belt (87). The photosensitive drum (80) is not shared by the respective colors, but the photosensitive drums (80Y) and (80M) for the respective colors. ), (80C), (80Bk). Further, a developing unit (developing means) (82), a drum cleaning unit (cleaning means) (85), a static elimination lamp (static elimination means) (83), a charging roller (charging means) (84) for uniformly charging the drum, a bias A roller (secondary transfer means) (86) is also provided for each color. In the printer shown in FIG. 7, the charging charger (53) is provided as the drum uniform charging means, but in this apparatus, the charging roller (84) is provided. A fur brush (94) is provided as a belt cleaning unit for cleaning the intermediate transfer belt (87).
In addition, a pair of registration rollers (88), paper (89) as a recording material, a paper transfer bias roller (90) as a secondary transfer means, a transfer belt (91), a conveyance belt (92), and a fixing unit (93) However, since it overlaps with the above-described third embodiment, the description thereof is omitted.
In the tandem method, latent image formation (image exposure process) and development of each color can be performed in parallel, so that the image formation speed can be much faster than the revolver method.

[Process cartridge]
The image forming apparatus as described above may be fixedly incorporated in a copying apparatus, facsimile, or printer, but may be incorporated in these apparatuses in the form of a process cartridge. The process cartridge is a device (component) including a photosensitive member (16) and at least one means selected from a charging means, an image exposure means, a developing means, a transfer means, a cleaning means, and a charge eliminating means. ).
The process cartridge has various shapes and the like, and a general example is shown in FIG.
FIG. 9 is a schematic diagram showing the configuration of an embodiment of a process cartridge according to the present invention.
In the present embodiment, an electrophotographic photosensitive member (16), a charging charger (17) as a charging unit, an image exposure unit (19) as an image exposing unit, a developing roller (20) as a developing unit, And a cleaning brush (18) as a cleaning means.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated, this invention is not restrict | limited by an Example. All parts are parts by weight.

  An undercoat layer coating solution, a charge generation layer coating solution, and a charge transport layer coating solution having the following composition are sequentially applied by dip coating on a φ30 mm aluminum cylinder, dried, and a 3.5 μm undercoat layer; A 0.1 μm charge generation layer and a 23 μm charge transport layer were formed to produce an NO1 electrophotographic photosensitive member.

◎ Undercoat layer coating solution / titanium dioxide powder (Ishihara Sangyo Co., Ltd., Tybak CR-EL): 400 parts / Melamine resin (Dainippon Ink Co., Ltd., Super Becamine G821-60): 65 parts / Alkyd resin (large Nippon Ink Co., Ltd., Beckolite M6401-50): 120 parts, 2-butanone: 400 parts

Charge generation layer coating solution-fluorenone bisazo pigment having the following structure: 12 parts-Polyvinyl butyral (manufactured by Sekisui Chemical Co., Ltd., BX-1): 5 parts-2-butanone: 200 parts-cyclohexanone: 400 parts

Charge transport layer coating solution / polycarbonate resin (TS-2050, manufactured by Teijin Chemicals): 10 parts Charge transport material of Exemplified Compound CT-3: 9 parts Amine compound of formula (2a): 1 part Tetrahydrofuran : 100 copies

  The photoconductor of Example 1 prepared in this way is mounted on an electrophotographic process cartridge, mounted on a black station of a tandem type Ricoh laser printer IPSIO SP C220, exposed to a laser beam having a wavelength of 655 nm, and black loaded with toner. Image blur was evaluated by printing a gray halftone image (2by2) using a developing unit and visually observing the dot image with a magnifier of about 30 times. Note that 2by2 means a print pattern that forms dots of 2 × 2 pixels out of 4 × 4 pixels.

<< Judgment criteria for image blur >>
A: Level where dots are reproduced well.
○: A slight change in the dot diameter is recognized but does not cause a problem.
Δ: Level at which change in dot diameter is clearly recognized.
X: The dot is hardly reproduced.

A potential measuring unit in which the developing roller of the black developing unit was removed and a surface potentiometer was attached was used to evaluate post-exposure potential VL and job fluctuations during full exposure of the laser beam. In order to evaluate the variation within the job, first, the exposed portion potential (VL) of the photoconductor is measured using a surface potentiometer, and then the continuous printing of 50 sheets is set to 1 Job, and this is repeated 10 times, and then the exposed portion potential is set again. Measurement was performed, and <VL after repeated printing>-<first VL> was evaluated as variation within the job.
<Judgment criteria for intra-job variation>
A: Level that is not a problem.
○: A slight change is recognized, but it does not cause a problem as long as it can be corrected.
(Triangle | delta): The level which a change was recognized clearly and exceeded a tolerance level a little.
X: Level that is greatly changed and regarded as a problem.
The charging roller conditions were set so that the charging potential VD of the photosensitive member was approximately 600 (-V), and the developing bias Vb was set to 450 (-V). The post-exposure potential VL is preferably “post-exposure potential VL−development bias Vb> 200 V”. When the post-exposure potential VL> 250 (−V), the image has a low density.
Next, after exposing the electrophotographic photoreceptor to NOx exposure test equipment (manufactured by Directec) at a NO concentration of 40 ppm and a NO2 concentration of 10 ppm for 4 days, a gray halftone image (2by2) was printed using a black developing unit. Image blur was evaluated. Subsequently, after the developing roller of the black developing unit was removed and the potential measuring unit with the surface potential meter attached was used, the post-exposure potential VL and the fluctuation in the job at the time of laser beam full exposure were evaluated.

  Reinstall the black development unit, and use a 5% writing rate chart at normal temperature and humidity (characters equivalent to 5% of the image area are written on the entire A4 surface). After repeated printing of the sheets, the image quality (image blur etc.) was evaluated. Thereafter, the potential measurement unit was used to evaluate post-exposure potential VL and in-job variation. The results are shown in Table 3.

  In Example 1, a NO2 electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that the amine compound (2b) shown in Table 2 was used instead of the formula (2a). . The results are shown in Table 3.

  In Example 1, an NO 3 electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 1 except that the amine compound (2c) shown in Table 2 was used instead of the formula (2a). . The results are shown in Table 3.

  In Example 1, an NO4 electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that the amine compound (2d) shown in Table 2 was used instead of the formula (2a). . The results are shown in Table 3.

  In Example 1, an NO5 electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that the amine compound (2e) shown in Table 2 was used instead of the formula (2a). . The results are shown in Table 3.

  In Example 1, CT-6 shown in Table 1 was used instead of the charge transport material of Exemplified Compound F-3, and the amine compound (2b) shown in Table 2 was used instead of the formula (2a). A NO6 electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except for the above. The results are shown in Table 3.

  In Example 1, CT-8 shown in Table 1 was used instead of the charge transport material of Exemplified Compound F-3, and the amine compound (2c) shown in Table 2 was used instead of the formula (2a). A NO7 electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except for the above. The results are shown in Table 3.

A NO8 electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 1 except that the charge generation layer coating solution and the charge transport layer coating solution were changed to the following in Example 1. The results are shown in Table 3. CT-8 shown in Table 1 was used as the charge transport material, and the amine compound (2d) shown in Table 2 was used as the amine compound.
Charge generation layer coating solution-Titanyl phthalocyanine having powder XD spectrum shown in Fig. 10: 8 parts-Polyvinyl butyral (BX-1; manufactured by Sekisui Chemical Co., Ltd.): 5 parts-2-butanone: 400 parts-Charge transport layer coating Industrial fluid / polycarbonate resin (TS-2050; manufactured by Teijin Chemicals Ltd.): 10 parts / charge transport material: 8 parts / amine compound: 2 parts / tetrahydrofuran: 100 parts In Example 1, the charge transport material of Exemplified Compound F-3 In the same manner as in Example 1, except that CT-5 shown in Table 1 was used instead of, and the amine compound (2d) shown in Table 2 was used instead of the formula (2a), NO8 An electrophotographic photoreceptor was prepared and evaluated. The results are shown in Table 3.

(Comparative Example 1)
An electrophotographic photosensitive member of Comparative Example 1 was prepared and evaluated in the same manner as in Example 1 except that the amine compound of formula (2a) was not added in Example 1. The results are shown in Table 4.

(Comparative Example 2)
In Example 1, an electrophotographic photosensitive member of Comparative Example 2 was prepared and evaluated in the same manner as in Example 1 except that the compound of the following structural formula (4) was used instead of the amine compound of formula (2a). The results are shown in Table 4.

(Comparative Example 3)
In Example 1, an electrophotographic photosensitive member of Comparative Example 3 was prepared and evaluated in the same manner as in Example 1 except that the compound of the following structural formula (5) was used instead of the amine compound of formula (2a). The results are shown in Table 4.

(Comparative Example 4)
In Example 1, an electrophotographic photoreceptor of Comparative Example 4 was prepared and evaluated in the same manner as in Example 1 except that the compound of the following structural formula (6) was used instead of the amine compound of formula (2a). The results are shown in Table 4.

(Comparative Example 5)
An electrophotographic photoreceptor of Comparative Example 5 was prepared and evaluated in the same manner as in Example 1 except that the charge transport material was changed to the compound of the following structural formula (7) in Example 1. The results are shown in Table 5.

(Comparative Example 6)
An electrophotographic photoreceptor of Comparative Example 6 was prepared and evaluated in the same manner as in Example 1 except that the charge transport material was changed to the compound of the following structural formula (8) in Example 1. The results are shown in Table 5.

The photoconductor of the present invention has stable photoconductor characteristics even after repeated use over a long period of time, does not cause image deterioration such as image blurring, has less fluctuation in the job, and does not increase much even after repeated use.
On the other hand, when the amine compound of Comparative Examples 1 to 4 (2) is not included or other amine compound is used, the initial image quality is good, but the image deterioration due to NOx exposure and repeated use. It cannot be suppressed.
Comparative Examples 5 to 6 are cases where combined with other charge transport materials, and image degradation after exposure to NOx is slight, but after repeated use, fluctuations in the job and image blurring are remarkable.
As described above, according to the present invention, the electrophotographic characteristics can be stably obtained over a long period of time because the characteristics of the photoreceptor are stable after NOx exposure and even after repeated use over a long period of time, and the fluctuation in the job is also suppressed. A photoreceptor can be provided.
Further, according to the present invention, an electrophotographic method, an electrophotographic apparatus, and an electrophotographic apparatus 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. A process cartridge is provided.

(About FIG. 1, FIG. 2, FIG. 3, FIG. 4)
31 Conductive Support 33 Photosensitive Layer 35 Charge Generation Layer 37 Charge Transport Layer 39 Protective Layer (About FIG. 5)
DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Static elimination lamp 3 Charger charger 5 Image exposure means (image exposure part)
6 Development unit 7 Pre-transfer charger 8 Recording material transport means 9 Recording material (transfer paper)
10 Transfer means (transfer charger)
11 Separation Charger 12 Separation Claw 13 Charger Before Cleaning 14 Cleaning Means (Fur Brush)
15 Cleaning means (cleaning blade)
(About Figure 6)
21 Photoconductor 22a Drive roller 22b Drive roller 23 Charging means (charger)
24 Image exposure means (light source)
25 Transfer means (transfer charger)
26 Pre-cleaning exposure means 27 Cleaning means (cleaning brush)
28 Static elimination means (light source)
(About Figure 7)
50 Revolver development unit 53 Charger charger 54 Static elimination means (static elimination lamp)
55 Cleaning means (drum cleaning unit)
56 Latent image carrier (drum-shaped photoreceptor)
57 Transfer means (intermediate transfer bias roller)
58 Intermediate transfer belt 59a Tension roller 59b Secondary transfer backup roller 59c Belt drive roller 60 Recording material (transfer paper)
61 Registration roller pair 62 Transfer belt 63 Transfer bias roller 64 Conveying belt 65 Fixing unit (about FIG. 8)
80 Photosensitive drum 80Y Photosensitive drum for each color 80M Photosensitive drum for each color 80C Photosensitive drum for each color 80Bk Photosensitive drum for each color 81 Exposure light source 82 Developing unit (developing unit)
83 Static elimination lamp (static elimination means)
84 Charging roller (charging means)
85 Drum cleaning unit (cleaning means)
86 Bias roller (secondary transfer means)
87 Intermediate transfer belt 88 Registration roller pair 89 Recording material (recording paper)
90 Secondary transfer means (paper transfer bias roller)
91 Transfer Belt 92 Conveyor Belt 93 Fixing Unit 94 Belt Cleaning Unit (Fur Brush)
(About Figure 9)
16 Photoconductor 17 Charger 18 Cleaning means (cleaning brush)
19 Image exposure unit 20 Developing means (developing roller)

Japanese Unexamined Patent Publication No. 01-230055 Japanese Patent Laid-Open No. 03-172852 JP 2002-333731 A Japanese Patent Laid-Open No. 04-56866 Japanese Patent No. 4101676 JP 2009-42564 A JP-A-10-69108

Claims (8)

In an electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, the photosensitive layer is represented by a charge transport material represented by the following general formula (1) and any one of the following formulas (2b) to (2e). And an amine compound to be produced.

(In the formula, Ar 4 and Ar 5 represent an aryl group which may have a substituent, R 4 and R 5 represent an alkyl group, an aralkyl group or an aryl group which may have a substituent, and R 6 represents A hydrogen atom, an alkyl group, an alkoxy group, a hydroxyl group or a halogen atom which may have a substituent.

  2. A charging step for charging the surface of the electrophotographic photosensitive member according to claim 1, an image exposure step for forming an electrostatic latent image on the electrophotographic photosensitive member, and a toner image formed by developing the electrostatic latent image. An electrophotographic method comprising: repeatedly performing a developing step, and a transfer step of transferring the toner image directly to a recording material or to a recording material via an intermediate transfer member.   2. A charging step for charging the surface of the electrophotographic photosensitive member according to claim 1, an image exposure step for forming an electrostatic latent image on the electrophotographic photosensitive member, and a toner image formed by developing the electrostatic latent image. A developing process for transferring the toner image directly to the recording material or to a recording material via an intermediate transfer member, and the image exposure process includes forming the electrostatic latent image by an LD or an LED. A digital electrophotographic method characterized by:   The electrophotographic photosensitive member according to claim 1, charging means for charging the surface of the electrophotographic photosensitive member, image exposure means for forming an electrostatic latent image on the surface of the electrophotographic photosensitive member, and the electrostatic latent image An electrophotographic apparatus comprising: a developing unit that forms a toner image by developing; and a transfer unit that transfers the toner image directly to a recording material or to an intermediate transfer member.   The electrophotographic photosensitive member according to claim 1, charging means for charging the surface of the electrophotographic photosensitive member, image exposure means for forming an electrostatic latent image on the surface of the electrophotographic photosensitive member, and the electrostatic latent image And developing means for forming a toner image by development, and transfer means for transferring the toner image directly to a recording material or an intermediate transfer member, wherein the image exposure means is an LD or an LED. A digital electrophotographic device.   6. The electrophotographic apparatus according to claim 4, wherein the electrophotographic photosensitive member is a tandem type having a plurality of each of the electrophotographic photosensitive member, the charging unit, the developing unit, and the transfer unit.   The image forming apparatus further includes an intermediate transfer member and an intermediate transfer unit, and the transfer unit primarily transfers the toner image formed on the electrophotographic photosensitive member to the intermediate transfer member to form an image on the intermediate transfer member. The intermediate transfer unit secondarily transfers the image on the intermediate transfer member onto the recording material, and when the image on the intermediate transfer member is a color image made of a plurality of colors of toner, the transfer unit includes: Each color is sequentially superimposed on the intermediate transfer member to form an image on the intermediate transfer member, and the intermediate transfer unit performs secondary transfer of the image on the intermediate transfer onto the recording material at once. The electrophotographic apparatus according to any one of claims 4 to 6.   2. The electrophotographic photosensitive member according to claim 1, charging means for charging the surface of the electrophotographic photosensitive member, image exposure means for forming an electrostatic latent image on the surface of the electrophotographic photosensitive member, and developing the electrostatic latent image. Developing means for forming a toner image, at least one selected from a cleaning means for cleaning the surface of the electrophotographic photosensitive member, and a transfer means for directly transferring the toner image to a recording material or transferring it to an intermediate transfer member. A process cartridge for an electrophotographic apparatus comprising:

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