JP4814714B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus such as an electrophotographic copying machine, a laser printer, and a facsimile, and a process cartridge for an image forming apparatus including a charging unit and an electrophotographic photosensitive member disposed in the image forming apparatus.

In an image forming apparatus that forms an image using indirect electrophotography, such as a facsimile, a laser beam printer, a copying machine, etc., charging, image exposure, focusing on an electrophotographic photoreceptor (hereinafter simply referred to as “photoreceptor”), Each means such as development, transfer, separation, cleaning and static elimination is provided, and image formation is performed on the photosensitive member in such a manner that each means operates in order.
In recent years, such image forming apparatuses are increasingly required to have high image quality and high durability. In order to achieve such miniaturization and high durability, it is indispensable to improve the charge transport material which is a main material contained in the photosensitive layer of the photoreceptor. This is because, when the load on each means such as charging and exposure as described above is repeated, the charging property gradually decreases and the potential at the time of exposure rises. This is because a sufficient electrostatic contrast cannot be obtained.

On the other hand, in order to improve the durability of the entire image forming apparatus, it is necessary not only to improve the electrostatic repetitive characteristics of the photosensitive layer but also to improve the mechanical durability due to such repeated operations. This is because the photosensitive member may be slightly kinked or distorted due to the force applied to the rotating operation of the photosensitive member for a long period of time.
In the drive of the photoconductor, the driving force is usually transmitted through a member fitted to both ends of the photoconductor, a so-called flange. However, since such a drive is performed for a long period of time, there is a slight twist or distortion in the flange joint. As a result, the shake accuracy during rotation of the photosensitive member changes. Such subtle twists and distortions have not been a problem in conventional image forming apparatuses, but in image forming apparatuses that have been required in recent years, particularly in full-color image forming apparatuses that make full use of advanced color superposition technology. There are cases where such slight twists and distortions affect the output image.
In order to suppress such twisting and distortion of the flange fitting portion, a method such as making the flange member the same as or slightly larger than the inner diameter of the drum as the photosensitive member support is considered in order to strengthen the fitting. However, when such a method is adopted, problems such as the roundness of the drum changing due to the force applied when the flange is mounted, and the runout accuracy are lowered. In addition, the conventional flange fixing with an adhesive also slightly changes the accuracy of the flange fitting portion due to shrinkage or expansion that occurs when the adhesive is solidified.
In addition to this, problems such as resonance noise generated during charging and rubbing noise generated by contact with the cleaning member have also occurred.

  Here, a description will be added regarding charging of the photosensitive member. The photosensitive member is charged (charged) at −300 to −800 volts by charging means. There are two methods for applying a voltage to the charging means: a case where a DC voltage is applied and a case where a DC voltage superimposed with an AC voltage is applied. Although it is possible to create an image with no problem in practice with only DC voltage, the charging member is less affected by environmental conditions by superimposing the AC voltage on the DC voltage, and occurs when using the contact charging method. In addition, it is possible to significantly reduce potential unevenness that is considered to be caused by unevenness of the photosensitive member, minute unevenness of the member, and the like.

On the other hand, a charging method that is generally employed at present is that a high voltage of about −4000 to −6000 V is applied to a metal wire such as a tungsten wire or a nickel wire having a diameter of 40 to 80 μm that is built in a shield case. A corona charging method for charging a photosensitive member. A DC voltage of -1200 to -2000 V or a DC voltage of -500 to -900 V is applied to a charging member such as a roller shape or a brush shape having a resistance of about 10 ² to 10 ⁸ Ω · cm. In addition, a contact charging method in which the photosensitive member is charged while applying an alternating voltage of 1000 to 2500 V / 500 to 4500 Hz, or the charging member and the photosensitive member are arranged close to each other at a distance of about 30 to 250 μm. There is a proximity non-contact charging method in which the voltage is applied to charge the photoreceptor.
Since a high voltage is applied in the corona charging method, high-concentration ozone is generated. For this reason, there are environmental problems due to ozone odor, and metal wires such as the aforementioned tungsten wires and nickel wires are contaminated with discharge products due to repeated use. Therefore, in recent years, a contact charging method capable of charging with a low applied voltage has been performed, and the generation of ozone is extremely low at 0.1 ppm or less. Therefore, in recent years, there are an increasing number of image forming apparatuses that use a contact charging method that generates a small amount of ozone and applies an alternating voltage superimposed DC voltage to the charging member.

  However, when applied to a charging means in which an AC voltage is superimposed on a DC voltage, there is a noise problem that an irritating charging sound is generated during charging, in addition to the generation of ozone and nitrogen oxides that cause image quality degradation. There is. This charging sound is hardly a problem with a DC voltage, and is a phenomenon peculiar to alternating current because it is called an oscillating current. The larger the amplitude and the more easily the material that the support of the photoconductor resonates, the more the charging sound growing. Therefore, it is desirable to set the conditions as low as possible. However, if the charging stability is increased, the conditions become inevitably severe and the charging noise increases, so it is essential to take measures.

As means for improving this phenomenon, methods such as increasing the thickness of the support of the photosensitive member, inserting a damping material (filler) inside the drum-shaped photosensitive member, and improving the charging member side have been proposed. . These methods are aimed at suppressing the resonance of the photosensitive member and shifting the resonance frequency to a direction where it is difficult to be felt by the ear, and the following examples have been proposed.
For example, as a method for improving the generation of a charging sound (high-frequency sound) during charging by inserting a damping material inside the drum-shaped photoconductor, a buffer material is press-fitted into the photosensitive drum (for example, Patent Documents). 1), filling the inside of the photoconductor with a viscoelastic material (for example, see Patent Document 2), and inserting a rigid body with a density of 2.0 g / cm ³ or more into the inside of the photoconductor (for example, Patent Document 2). 3) a member composed of two or more elastic bodies (O-rings) and a cylindrical member (a plastic having a specific gravity of 1.5 or more (polybutylene terephthalate resin containing 20% or more of glass fibers)) to the photoreceptor. Can be inserted (for example, see Patent Document 4), and a resin cylindrical member with a built-in metal spring can be inserted and fixed to the wall of the photosensitive body with a pressing force (for example, see Patent Document 5). Proposed.

Further, as a method for increasing the thickness of the photoreceptor substrate to enhance the vibration damping effect, the vibration damping effect is obtained by setting the substrate of the photoreceptor body to have an inlay and the thickness other than the inlay to be 1.9 mm or more. (For example, refer to Patent Document 6), it is possible to obtain a damping effect by setting the deposition density of the photosensitive member to 0.6 g / cm ³ or more and 2.0 g / cm ³ or less (for example, refer to Patent Document 7). )Proposed. Furthermore, as a method for achieving suppression of charging noise from the charging member, a coating layer is provided on the surface of the hollow charging member (roller), an elastic body is inserted into the charging member, and the cored bar is supported via the elastic body. It has been proposed to improve the charging sound by using a structure (see, for example, Patent Document 8). The charging method of the charging sound differs depending on whether the vibration frequency of the photosensitive member is shifted to a frequency range that does not cause an annoyance or the vibration itself is suppressed.

Each of the above methods has a greater or lesser effect. However, even if the contact charging method is improved, the non-contact charging method in which the charging member is disposed in close proximity to the photosensitive member may not be effective. For example, it is difficult to obtain a sufficient effect only by a method of suppressing charging noise with a charging member or by thickening the support of the photosensitive member. The method of increasing the weight and suppressing the sound (squeal) by inserting a filler inside the photosensitive member support is easy to obtain, but even if it is simply inserted, there is a gap between the support and the insertion material. If the weight is small, it is difficult to obtain the expected effect. In addition, the effect may be reduced when it is composed of a single member. Furthermore, in recent years, there is an environmental problem that needs to be recycled, reused, etc., so this point needs to be considered.
Moreover, if the said filler is inserted in the inside for the purpose of vibration suppression, a support body will deform | transform delicately. This is because the effect is small when there is a gap between the support and the filler to be inserted in order to suppress squealing, and it is necessary to make the support close to the filler. This is because it is slightly deformed by being pushed.

  In this way, depending on the charging method, there was a case where an unpleasant sound due to resonance or resonance occurred during charging. In addition to this, there have been cases where a member that contacts the photoconductor, such as a cleaning blade, generates a rubbing noise or chatter noise generated when the photoconductor rotates. As a countermeasure against such a problem, there is a method of increasing the weight and suppressing the sound (squeal) by inserting a filler inside the photosensitive member as described above. Since it is unavoidable that the body accuracy slightly decreases, it has not been able to sufficiently meet the recent demand for higher image quality.

Japanese Unexamined Patent Publication No. 63-60481 JP-A-3-105348 JP-A-5-197321 JP 11-184308 A JP 2000-321929 A JP 2000-19761 A JP 2000-155500 A Japanese Patent Laid-Open No. 9-230671

The object of the present invention has been made in view of the above-mentioned problems, and suppresses deterioration in image quality due to deterioration of the photosensitive layer constituting material due to repeated use over a long period of time, and correction of distortion of the photoreceptor due to repeated use over a long period of time. The main purpose is to improve the accuracy of the photoconductor support.
That is, it is an object of the present invention to provide an image forming apparatus capable of outputting a high-quality and highly durable image that can be achieved for the first time by improving them, and a process cartridge that is detachable from the image forming apparatus.

  As a result of intensive studies on the above problems, the present inventors have found that at least a drum-shaped conductive support is provided with a photosensitive layer, a charging means for uniformly charging the photosensitive member, and after uniform charging. Image exposing means for performing image exposure to form an electrostatic latent image; developing means for developing toner on the electrostatic latent image; means for transferring the developed image; and cleaning residual toner on the electrophotographic photosensitive member. In the image forming apparatus including the image forming unit including the cleaning unit, the photosensitive layer of the photoconductor includes the compound represented by the general formula (1) or the general formula (1-I), and the photoconductor. Is a drum-shaped support body, a flange having a pair of bearing holes respectively fitted to release portions at both ends of the support body, and a support body fixed to the center of each flange at the both ends. Penetrate the center axis of rotation It found that can achieve the above object by the image forming apparatus characterized by comprising to a shaft, leading to the present invention. Only with this configuration of the image forming apparatus, it is possible to achieve both high image quality and high durability.

In the present invention, first, a flange having a pair of bearing holes respectively fitted to the release portions at both ends of the photosensitive member support, and fixed to the center portion of each flange at the both ends to rotate through the support. By providing a shaft that forms the central axis, it is possible to reduce the drive stress from being applied to only one side of the support drum, and to suppress distortion and distortion in the photoreceptor flange fitting part and the support even during repeated use over a long period of time. As a result, it is possible to obtain a stable and highly accurate rotating operation, which makes it possible to obtain a high-quality and highly durable image forming apparatus as a whole.
As a secondary effect, the mounting rigidity is increased by passing the shaft passing through the flange of the open end of both ends, and even when using a charging mechanism that provides AC voltage superposition, the resonance of the generated frequency overtone is suppressed. Therefore, unpleasant resonance and resonance sound do not occur.

Since the image forming apparatus having such a structure has high durability and high rigidity, the electrophotographic photosensitive member used for the image forming apparatus, particularly the photosensitive layer, also has high durability and is high. It is desirable that the image can be formed over a long period of time, exhibiting rigidity and toughness, but the method of applying an AC voltage superimposed on a DC voltage to the charging means is harsh for the photosensitive layer. , Easy to deteriorate. In addition, it is generally difficult to exhibit rigidity and toughness for a long period of time so that an image without color misregistration can be formed in the image forming process.
However, when the charge transport material represented by the general formula (I) or the general formula (1-I) is used for the photosensitive layer, it is highly sensitive and can be used for a long-term charging and exposure (static elimination) cycle. It has been found that stable image formation with extremely little deterioration becomes possible.
Further, in addition to these charge transport materials, by further adding a charge transport material represented by the above general formula (1-II), the shrinkage during film formation is reduced without lowering the charge transport ability, Since it becomes dense, there is an advantage that it is more difficult to be affected by the acid gas, that is, the gas resistance is improved. In addition, there is an effect that the wear resistance is improved due to the dense film.

That is, according to the present invention, the following image forming apparatus is provided.
(1) A photosensitive member provided with a photosensitive layer on at least a drum-shaped conductive support, a charging means for uniformly charging the photosensitive member, and image exposure after uniform charging to form an electrostatic latent image An image exposure means, an image forming means comprising: a developing means for developing toner on the electrostatic latent image; a means for transferring the developed image; and a cleaning means for cleaning the transfer residual toner of the electrophotographic photosensitive member. In the forming apparatus, in the photosensitive layer of the photoreceptor , at least one of the charge transport materials represented by the following general formula (1) , preferably the electron transport materials represented by the following structural formulas (a) to (g) is contained. And the photosensitive member includes a drum-shaped support portion, a flange having a pair of bearing holes that are respectively fitted to release portions at both ends of the support, and center portions of the flanges at both ends. To be supported by An image forming apparatus comprising: a shaft forming the rotation axis through the body.

「なお、上記一般式（１）において、Ｒ１、Ｒ２は、それぞれ独立に水素原子、置換又は無置換のアルキル基、置換又は無置換のシクロアルキル基、置換又は無置換のアラルキル基からなる群より選ばれる基を表わし、Ｒ３、Ｒ４、Ｒ５、Ｒ６、Ｒ７、Ｒ８、Ｒ９、Ｒ１０はそれぞれ独立に水素原子、ハロゲン原子、シアノ基、ニトロ基、アミノ基、水酸基、置換又は無置換のアルキル基、置換又は無置換のシクロアルキル基、置換又は無置換のアラルキル基からなる群より選ばれる基を表わす。」
（２）少なくともドラム状の導電性支持体に感光層が設けられた感光体と、前記感光体を一様に帯電する帯電手段と、一様帯電後に像露光を行ない、静電潜像を形成する像露光手段と、前記静電潜像にトナーを現像する現像手段及び現像像を転写する手段と、該電子写真感光体の転写残トナーをクリーニングするクリーニング手段を備える画像形成手段を具備する画像形成装置において、前記感光体の感光層中に下記一般式（１−Ｉ）で表わされる電荷輸送物質を含有し、且つ前記感光体はドラム状の支持体部と該支持体の両端の解放部にそれぞれに嵌合される一対の各軸受け孔を有するフランジと、該両端部におけるそれぞれのフランジの中心部に固持されて支持体を貫通し回転中心軸をなすシャフトを備えることを特徴とする画像形成装置。

“In the general formula (1) , R1 and R2 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, or a substituted or unsubstituted aralkyl group. R3, R4, R5, R6, R7, R8, R9 and R10 each independently represents a hydrogen atom, a halogen atom, a cyano group, a nitro group, an amino group, a hydroxyl group, a substituted or unsubstituted alkyl group, It represents a group selected from the group consisting of a substituted or unsubstituted cycloalkyl group and a substituted or unsubstituted aralkyl group.
(2) At least a drum-shaped conductive support provided with a photosensitive layer, a charging means for uniformly charging the photosensitive member, and image exposure after uniform charging to form an electrostatic latent image An image exposure means, an image forming means comprising: a developing means for developing toner on the electrostatic latent image; a means for transferring the developed image; and a cleaning means for cleaning the transfer residual toner of the electrophotographic photosensitive member. In the forming apparatus, the photosensitive layer of the photosensitive member contains a charge transport material represented by the following general formula (1-I), and the photosensitive member has a drum-shaped support part and open parts at both ends of the support. And a flange having a pair of bearing holes respectively fitted to each other, and a shaft that is fixed to the center of each flange at both ends and penetrates the support to form a rotation center axis. Molding .

「ただし、式中、Ｒ１、Ｒ２は、それぞれ独立に水素原子、置換又は無置換のアルキル基、置換又は無置換のシクロアルキル基、置換又は無置換のアラルキル基からなる群より選ばれる基を表し、Ｒ３、Ｒ４、Ｒ５、Ｒ６、Ｒ７、Ｒ８、Ｒ９、Ｒ１０、Ｒ１１、Ｒ１２、Ｒ１３、Ｒ１４はそれぞれ独立に水素原子、ハロゲン原子、シアノ基、ニトロ基、アミノ基、水酸基、置換又は無置換のアルキル基、置換又は無置換のシクロアルキル基、置換又は無置換のアラルキル基からなる群より選ばれる基を表し、ｎは繰り返し単位であり、１から１００までの整数を表す。」
（３）前記電荷輸送物質に加えて、さらに下記一般式（１−II）で表される電荷輸送物質を含有することを特徴とする（１）または（２）に記載の電子写真装置

"In the formula, R1 and R2 each independently represents a group selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aralkyl group. , R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14 are each independently a hydrogen atom, halogen atom, cyano group, nitro group, amino group, hydroxyl group, substituted or unsubstituted Represents a group selected from the group consisting of an alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aralkyl group, and n is a repeating unit and represents an integer of 1 to 100.
(3) The electrophotographic apparatus according to (1) or (2), further comprising a charge transport material represented by the following general formula (1-II) in addition to the charge transport material

「式中、Ｒ１５、Ｒ１６は、それぞれ独立に水素原子、置換又は無置換のアルキル基、置換又は無置換のシクロアルキル基、置換又は無置換のアラルキル基からなる群より選ばれる基を表し、Ｒ１７、Ｒ１８、Ｒ１９、Ｒ２０はそれぞれ独立に水素原子、ハロゲン原子、シアノ基、ニトロ基、アミノ基、水酸基、置換又は無置換のアルキル基、置換又は無置換のシクロアルキル基、置換又は無置換のアラルキル基からなる群より選ばれる基を表す。」
（４）前記シャフトの直径Ｌが長手方向の少なくとも一部分において３ｍｍ≦Ｌ≦２０ｍｍになる関係を満たすことを特徴とする（１）乃至（３）のいずれかに記載の画像形成装置。
（５）前記シャフトが金属製であることを特徴とする（１）乃至（４）のいずれかに記載の画像形成装置。
（６）前記シャフトがステンレス製であることを特徴とする（１）乃至（４）のいずれかに記載の画像形成装置。
（７）少なくとも帯電手段、露光手段、現像手段、転写手段の一つと電子写真感光体とを具備してなり、（１）乃至（６）のいずれかに記載の画像形成装置に用いられ、着脱自在であるプロセスカートリッジ。
（８）前記画像形成装置が、電子写真感光体上に現像されたトナー像を中間転写体上に一次転写した後、該中間転写体上のトナー画像を記録材上に二次転写する中間転写手段を有する画像形成装置であって、複数色のトナー画像を記録材上に一括で二次転写することを特徴とする（１）乃至（６）のいずれかに記載の画像形成装置。

In the formula, R15 and R16 each independently represents a group selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aralkyl group; , R18, R19 and R20 are each independently a hydrogen atom, halogen atom, cyano group, nitro group, amino group, hydroxyl group, substituted or unsubstituted alkyl group, substituted or unsubstituted cycloalkyl group, substituted or unsubstituted aralkyl. Represents a group selected from the group consisting of groups. "
(4) The image forming apparatus according to any one of (1) to (3), wherein a diameter L of the shaft satisfies a relationship of 3 mm ≦ L ≦ 20 mm in at least a part of the longitudinal direction.
(5) The image forming apparatus according to any one of (1) to (4), wherein the shaft is made of metal.
(6) The image forming apparatus according to any one of (1) to (4), wherein the shaft is made of stainless steel.
(7) At least one of charging means, exposure means, developing means, and transfer means and an electrophotographic photosensitive member, and used in the image forming apparatus according to any one of (1) to (6), are attached and detached. Process cartridge that is free.
(8) Intermediate transfer in which the image forming apparatus primarily transfers the toner image developed on the electrophotographic photosensitive member onto the intermediate transfer member, and then secondarily transfers the toner image on the intermediate transfer member onto the recording material. The image forming apparatus according to any one of (1) to (6), wherein the plurality of color toner images are collectively transferred onto a recording material.

  As will be apparent from the following detailed and specific description, according to the present invention, reduction in image quality due to deterioration of the photosensitive layer constituting material due to repeated use over a long period of time and correction of distortion of the photoreceptor due to repeated use over a long period of time (photosensitive body) It is possible to provide an image forming apparatus capable of outputting a high-quality and highly durable image, and a process cartridge that can be detached from the image forming apparatus. is there.

Hereinafter, an example of an image forming apparatus used in the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic diagram for explaining an example of an image forming apparatus of the present invention.
In FIG. 1, a photoconductor (11) is an electrophotographic photoconductor (hereinafter sometimes referred to as a photoconductor) that satisfies the requirements of the present invention. The photosensitive member (11) has a drum shape, and is provided with a pair of flanges (not shown) at both ends and a shaft (penetrating shaft) (19) passing therethrough.
The flange is a member that is fitted to one or both ends of the photosensitive drum and supports or rotationally drives the drum. For example, the flange is made of a resin such as plastic or a part of metal. Usually, a gear is provided on the flange, and a driving force for rotation is obtained through the gear. The shaft preferably has a diameter of 3 mm or more and 20 mm or less in at least a part of the longitudinal direction from the viewpoint of securing its rigidity. This is because if it is less than 3 mm, the strength may not be sufficient. On the other hand, if it exceeds 20 mm, problems such as an increase in weight and an inertial force at the time of rotational driving tend to occur, making it difficult to perform precise position control for starting and stopping rotation. The material of the shaft is not particularly limited, but a metal material is preferable. Furthermore, it is more preferable to use stainless steel that is less susceptible to rust because of stability over time.

The charging member (22) is an example using a charging roller including a shaft portion and a main body portion covering the shaft portion. In the present invention, the charging member (22) is arranged to face the photoconductor (11) with a minute gap (G).
The gap (G) between the charging member (22) and the photosensitive member (11) is adjusted by providing a spacer member having a certain thickness in the non-image forming region of the charging member (22), but the drum is a support. The higher the accuracy, the more stable the image is formed.
A commonly used charger can be used as the transfer means (16), but a combination of a transfer charger and a separation charger is effective.
The light source used for the exposure means (13), the charge removal means (1A), etc. includes fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light emitting diodes (LEDs), semiconductor lasers (LDs), electroluminescence ( EL) in general. Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.

The toner (15) developed on the photoreceptor by the developing means (14) is transferred to the image receiving medium (18), but not all is transferred, and toner remaining on the photoreceptor is also generated. Such toner is removed from the photoreceptor by the cleaning means (17). As the cleaning means, a rubber cleaning blade, a brush such as a fur brush, a mag fur brush, or the like can be used.
The toner used in the developing means is not particularly limited, and those generally used can be used.
When the electrophotographic photosensitive member is positively (negatively) charged and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. A positive image can be obtained by developing this with negative (positive) toner (electrodetection fine particles), and a negative image can be obtained by developing with positive (negative) toner. A known method is applied to the developing unit, and a known method is also used for the charge eliminating unit.
The above-described image forming apparatus based on the electrophotographic process can be used alone, but a high-speed full-color image can be output by adopting a so-called tandem configuration in which a plurality are arranged in parallel.

  Further, the image forming means as described above may be fixedly incorporated in a copying machine, a facsimile, or a printer, but may be incorporated in these apparatuses in the form of a process cartridge. A process cartridge is an apparatus (part) that contains an electrophotographic photosensitive member and includes at least one of charging means, exposure means, developing means, transfer means, cleaning means, and static elimination means. There are many shapes and the like of the process cartridge, but a general example is the one shown in FIG. FIG. 2 is basically a unit in which the means shown in FIG.

FIG. 3 shows another example of the image forming apparatus according to the present invention.
The image forming operation is performed as follows. First, in each of the image forming elements (6C), (6M), (6Y), (6K), the photoconductors (1C), (1M), (1Y), (1K) are in the direction indicated by the arrow (the direction along with the photoconductor). ) Charged by rotating charging members (2C), (2M), (2Y), (2K), and then created by laser light (3C), (3M), (3Y), (3K) at the exposed portion An electrostatic latent image corresponding to each color image is formed. Next, the latent image is developed by the developing members (4C), (4M), (4Y), and (4K) to form a toner image. Development members (4C), (4M), (4Y), and (4K) are development members that perform development with toners of C (cyan), M (magenta), Y (yellow), and K (black), respectively. The toner images of the respective colors formed on the two photoconductors (1C), (1M), (1Y), and (1K) are superimposed on the transfer paper. The transfer paper (7) is fed out from the tray by the paper feed roller (8), temporarily stopped by the pair of registration rollers (9), and then transferred to the transfer conveyance belt (10) in synchronization with the image formation on the photosensitive member. Sent. The transfer paper (7) held on the transfer conveyance belt (10) is conveyed, and each color is in contact position (transfer section) with each photoconductor (1C), (1M), (1Y), (1K). The toner image is transferred. The toner image on the photoconductor is transferred to the transfer brush (11C), (11M), (11Y), (11K) and the photoconductor (1C), (1M), (1Y), (1K). The image is transferred onto the transfer paper (7) by an electric field formed from the potential difference. Then, the recording paper (7) on which the toner images of four colors are superimposed through the four transfer portions is conveyed to the fixing device (12), where the toner is fixed, and is discharged to a paper discharge portion (not shown). Further, residual toner remaining on the photosensitive members (1C), (1M), (1Y), and (1K) without being transferred by the transfer unit is removed from the cleaning devices (5C), (5M), (5Y), ( 5K). In the example of FIG. 3, the image forming elements are arranged in the order of C (cyan), M (magenta), Y (yellow), and K (black) from the upstream side to the downstream side in the transfer paper conveyance direction. However, it is not limited to this order, and the color order is arbitrarily set. In FIG. 3, shafts (13K), (13Y), (13C), and (13M) penetrating the flanges at both ends are fixed to the photoreceptors (1K), (1Y), (1C), and (1M), respectively. .

Apart from this, the charging member is a corona charging method, which is a charging method generally used at present (-4000 mm to a metal wire such as a tungsten wire having a diameter of 40 to 80 μm and a nickel wire, which is built in a shield case). A method using a method of charging a photosensitive member by applying a high voltage of about −6000 V (not shown) may be used.
The circumferential (outer diameter) runout accuracy of the photoreceptor (11) is preferably 50 μm or less. As the circumferential (outer diameter) deflection accuracy increases, the image is likely to be misaligned. Especially when the full-color image forming apparatus is used, color misalignment is likely to occur, and the image quality of the output image is degraded. There is.

  FIG. 4 is a schematic cross-sectional view of an electrophotographic photosensitive member provided in the image forming apparatus of the present invention, and shows a so-called single-layered electrophotographic photosensitive member in which a photosensitive layer is provided on a conductive substrate.

  FIG. 5 and FIG. 6 each show a configuration example of another electrophotographic photosensitive member provided in the image forming apparatus of the present invention. FIG. 5 shows a function-separated type electrophotographic photoreceptor in which the photosensitive layer is composed of a charge generation layer (CGL) and a charge transport layer (CTL), and FIG. 6 shows a conductive substrate and a function-separated type photoconductor. 2 shows an electrophotographic photosensitive member in which an undercoat layer is inserted between the layers CGL and CTL. The electrophotographic photoreceptor according to the present invention may be either a single layer or a laminate as long as it has at least a photosensitive layer on a conductive support.

  The electrophotographic photoreceptor used in the present invention is an electrophotographic photoreceptor having at least a photosensitive layer on a conductive support, and having a charge transport material represented by the general formula (1) in the photosensitive layer.

「式中、Ｒ_１、Ｒ_２は、それぞれ独立に水素原子、置換又は無置換のアルキル基、置換又は無置換のシクロアルキル基、置換又は無置換のアラルキル基からなる群より選ばれる基を表わし、Ｒ_３、Ｒ_４、Ｒ_５、Ｒ_６、Ｒ_７、Ｒ_８、Ｒ_９、Ｒ_１０はそれぞれ独立に水素原子、ハロゲン原子、シアノ基、ニトロ基、アミノ基、水酸基、置換又は無置換のアルキル基、置換又は無置換のシクロアルキル基、置換又は無置換のアラルキル基からなる群より選ばれる基を表わす。」

“In the formula, R ₁ and R ₂ each independently represents a group selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aralkyl group. , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , R ₉ , R ₁₀ are each independently a hydrogen atom, halogen atom, cyano group, nitro group, amino group, hydroxyl group, substituted or unsubstituted It represents a group selected from the group consisting of an alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aralkyl group.

  The substituted or unsubstituted alkyl group is an alkyl group having 1 to 25 carbon atoms, preferably 1 to 10 carbon atoms, specifically a methyl group, an ethyl group, an n-propyl group, an n- Straight chain such as butyl group, n-pentyl group, n-hexyl group, n-peptyl group, n-octyl group, n-nonyl group, n-decyl group, i-propyl group, s-butyl group, t -Branched group such as butyl group, methylpropyl group, dimethylpropyl group, ethylpropyl group, diethylpropyl group, methylbutyl group, dimethylbutyl group, methylpentyl group, dimethylpentyl group, methylhexyl group, dimethylhexyl group, alkoxy Alkyl group, monoalkylaminoalkyl group, dialkylaminoalkyl group, halogen-substituted alkyl group, alkylcarbonylalkyl group, Kishiarukiru group, alkanoyloxy group, an aminoalkyl group, esterified optionally alkyl group substituted with a carboxyl group which have an alkyl group substituted by a cyano group are exemplified. The substitution position of these substituents is not particularly limited, and a group in which a part of carbon atoms of the substituted or unsubstituted alkyl group is substituted with a hetero atom (N, O, S, etc.) is also substituted. Included in the alkyl group.

  The substituted or unsubstituted cycloalkyl group includes a cycloalkyl ring having 3 to 25 carbon atoms, preferably 3 to 10 carbon atoms, specifically, a homocyclic ring from cyclopropane to cyclodecane, methylcyclo Those having an alkyl substituent such as pentane, dimethylcyclopentane, methylcyclohexane, dimethylcyclohexane, trimethylcyclohexane, tetramethylcyclohexane, ethylcyclohexane, diethylcyclohexane, t-butylcyclohexane, alkoxyalkyl groups, monoalkylaminoalkyl groups, dialkylamino Alkyl group, halogen-substituted alkyl group, alkoxycarbonylalkyl group, carboxyalkyl group, alkanoyloxyalkyl group, aminoalkyl group, halogen atom, amino group, esterified Which may be a carboxyl group, a cycloalkyl group substituted by a cyano group and the like. The substitution position of these substituents is not particularly limited, and a group in which a part of carbon atoms of the substituted or unsubstituted cycloalkyl group is substituted with a hetero atom (N, O, S, etc.) is also substituted. It is included in the cycloalkyl group.

Examples of the substituted or unsubstituted aralkyl group include groups in which an aromatic ring is substituted on the above-described substituted or unsubstituted alkyl group, and an aralkyl group having 6 to 14 carbon atoms is preferable. More specifically, benzyl group, perfluorophenylethyl group, 1-phenylethyl group, 2-phenylethyl group, terphenylethyl group, dimethylphenylethyl group, diethylphenylethyl group, t-butylphenylethyl group, 3- Examples thereof include a phenylpropyl group, a 4-phenylbutyl group, a 5-phenylpentyl group, a 6-phenylhexyl group, a benzhydryl group, and a trityl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

  More specifically, charge transport materials represented by the following formulas (2) to (8) can be given. In the formula, Me represents a methyl group.

該一般式（１）で表わされる電荷輸送物質の製造方法としては、下記の方法が例示できる。
ナフタレンカルボン酸は公知の合成方法（例えば、米国特許６７９４１０２号公報、Industrial Organic Pigments 2nd edition, VCH, 485 (1997) など）に従い、下記反応式より合成される。

Examples of the method for producing the charge transport material represented by the general formula (1) include the following methods.
Naphthalenecarboxylic acid is synthesized from the following reaction formula according to a known synthesis method (for example, US Pat. No. 6,794,102, Industrial Organic Pigments 2nd edition, VCH, 485 (1997)).

「式中、ＲｎはＲ_３、Ｒ_４、Ｒ_７、Ｒ_８を表わし、ＲｍはＲ_５、Ｒ_６、Ｒ_９、Ｒ_１０を表す。」

“In the formula, Rn represents R ₃ , R ₄ , R ₇ and R ₈ , and Rm represents R ₅ , R ₆ , R ₉ and R _10. ”

  The charge transporting material represented by the general formula (1) used in the present invention is a method of reacting the above naphthalenecarboxylic acid or its anhydride with amines to monoimidize, pH of the naphthalenecarboxylic acid or its anhydride with a buffer solution. It is obtained by a method of adjusting and reacting with diamines. Monoimidization is carried out without solvent or in the presence of a solvent. The solvent is not particularly limited, but it does not react with raw materials or products such as benzene, toluene, xylene, chloronaphthalene, acetic acid, pyridine, methylpyridine, dimethylformamide, dimethylacetamide, dimethylethyleneurea, dimethylsulfoxide, and the like. It is good to use what can be made to react at the temperature of -250 degreeC. For pH adjustment, a buffer solution prepared by mixing a basic aqueous solution such as lithium hydroxide or potassium hydroxide with an acid such as phosphoric acid is used. Carboxylic acid derivative dehydration reaction obtained by reacting carboxylic acid with amines or diamines is carried out in the absence of a solvent or in the presence of a solvent. Although there is no restriction | limiting in particular as a solvent, It is good to use what reacts at the temperature of 50 to 250 degreeC, without reacting with raw materials and products, such as benzene, toluene, chloronaphthalene, bromonaphthalene, and acetic anhydride. Any reaction may be carried out without a catalyst or in the presence of a catalyst, and is not particularly limited. For example, molecular sieves, benzenesulfonic acid, p-toluenesulfonic acid and the like can be used as a dehydrating agent.

  The electrophotographic photoreceptor used in the present invention is an electrophotographic photoreceptor having at least a photosensitive layer on a conductive support, and having the charge transport material represented by the general formula (1-I) in the photosensitive layer.

「ただし、式中、Ｒ１、Ｒ２は、それぞれ独立に水素原子、置換又は無置換のアルキル基、置換又は無置換のシクロアルキル基、置換又は無置換のアラルキル基からなる群より選ばれる基を表し、Ｒ３、Ｒ４、Ｒ５、Ｒ６、Ｒ７、Ｒ８、Ｒ９、Ｒ１０、Ｒ１１、Ｒ１２、Ｒ１３、Ｒ１４はそれぞれ独立に水素原子、ハロゲン原子、シアノ基、ニトロ基、アミノ基、水酸基、置換又は無置換のアルキル基、置換又は無置換のシクロアルキル基、置換又は無置換のアラルキル基からなる群より選ばれる基を表し、ｎは繰り返し単位であり、１から１００までの整数を表す。」

"In the formula, R1 and R2 each independently represents a group selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aralkyl group. , R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14 are each independently a hydrogen atom, halogen atom, cyano group, nitro group, amino group, hydroxyl group, substituted or unsubstituted Represents a group selected from the group consisting of an alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aralkyl group, and n is a repeating unit and represents an integer of 1 to 100.

  The substituted or unsubstituted alkyl group is an alkyl group having 1 to 25 carbon atoms, preferably 1 to 10 carbon atoms, specifically a methyl group, an ethyl group, an n-propyl group, an n- Straight chain such as butyl group, n-pentyl group, n-hexyl group, n-peptyl group, n-octyl group, n-nonyl group, n-decyl group, i-propyl group, s-butyl group, t -Branched group such as butyl group, methylpropyl group, dimethylpropyl group, ethylpropyl group, diethylpropyl group, methylbutyl group, dimethylbutyl group, methylpentyl group, dimethylpentyl group, methylhexyl group, dimethylhexyl group, alkoxy Alkyl group, monoalkylaminoalkyl group, dialkylaminoalkyl group, halogen-substituted alkyl group, alkylcarbonylalkyl group, Kishiarukiru group, alkanoyloxy group, an aminoalkyl group, esterified optionally alkyl group substituted with a carboxyl group which have an alkyl group substituted by a cyano group are exemplified. The substitution position of these substituents is not particularly limited, and a group in which a part of carbon atoms of the substituted or unsubstituted alkyl group is substituted with a hetero atom (N, O, S, etc.) is also substituted. Included in the alkyl group.

  The substituted or unsubstituted cycloalkyl group includes a cycloalkyl ring having 3 to 25 carbon atoms, preferably 3 to 10 carbon atoms, specifically, a homocyclic ring from cyclopropane to cyclodecane, methylcyclo Those having an alkyl substituent such as pentane, dimethylcyclopentane, methylcyclohexane, dimethylcyclohexane, trimethylcyclohexane, tetramethylcyclohexane, ethylcyclohexane, diethylcyclohexane, t-butylcyclohexane, alkoxyalkyl groups, monoalkylaminoalkyl groups, dialkylamino Alkyl group, halogen-substituted alkyl group, alkoxycarbonylalkyl group, carboxyalkyl group, alkanoyloxyalkyl group, aminoalkyl group, halogen atom, amino group, esterified Which may be a carboxyl group, a cycloalkyl group substituted by a cyano group and the like. The substitution position of these substituents is not particularly limited, and a group in which a part of carbon atoms of the substituted or unsubstituted cycloalkyl group is substituted with a hetero atom (N, O, S, etc.) is also substituted. It is included in the cycloalkyl group.

  Examples of the substituted or unsubstituted aralkyl group include groups in which an aromatic ring is substituted on the above-described substituted or unsubstituted alkyl group, and an aralkyl group having 6 to 14 carbon atoms is preferable. More specifically, benzyl group, perfluorophenylethyl group, 1-phenylethyl group, 2-phenylethyl group, terphenylethyl group, dimethylphenylethyl group, diethylphenylethyl group, t-butylphenylethyl group, 3- Examples thereof include a phenylpropyl group, a 4-phenylbutyl group, a 5-phenylpentyl group, a 6-phenylhexyl group, a benzhydryl group, and a trityl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

More specifically, examples of the charge transport material represented by the general formula (1-I) include the following compounds (however, in each of the formulas, the end groups at both ends represent Me (methyl group)). .)

（式中nは1〜100まで数値を表し、これらのものの混合体である。）

(In the formula, n represents a numerical value from 1 to 100 and is a mixture of these.)

The method for producing the charge transport material represented by the general formula (1-I) can be exemplified by the following two synthesis methods.

一般式（１−Ｉ）で表される電荷輸送物質の繰り返し単位ｎは１から１００の整数である。

The repeating unit n of the charge transport material represented by the general formula (1-I) is an integer of 1 to 100.

The repeating unit n is determined from the weight average molecular weight (Mw). That is, the compound exists with a distribution in molecular weight. When n exceeds 100, the molecular weight of the compound increases and the solubility in various solvents decreases, so 100 or less is preferable.
On the other hand, for example, when n is 1, it is a trimer of naphthalene carboxylic acid, but excellent electron transfer characteristics can be obtained even for oligomers by appropriately selecting substituents for R1 and R2. In this way, a wide range of naphthalenecarboxylic acid derivatives from oligomers to polymers are synthesized depending on the number of repeating units n.
In the range where the molecular weight of the oligomer region is small, monodispersed compounds can be obtained by stepwise synthesis. In the case of a compound having a large molecular weight, a compound having a distribution in molecular weight is obtained.
The charge transport material represented by the above formula (1-IA) was produced by the following method.

First Step: A 200 ml four-necked flask was charged with 5.0 g (18.6 mmol) of 1,4,5,8-naphthalenetetracarboxylic dianhydride and 50 ml of DMF and heated to reflux. To this, a mixture of 1.62 g (18.6 mmol) of 2-aminopentane and 25 ml of DMF was added dropwise with stirring. After completion of dropping, the mixture was heated to reflux for 6 hours. After completion of the reaction, the container was cooled and concentrated under reduced pressure. Toluene was added to the residue, and the residue was purified by silica gel column chromatography. Further, the recovered product was recrystallized from toluene / hexane to obtain 3.49 g of monoimide E (yield 45.8%).
Second Step In a 100 ml four-necked flask, 3.0 g (7.33 mmol) of monoimide E, 0.983 g (3.66 mmol) of 1,4,5,8-naphthalenetetracarboxylic dianhydride, 0.368 g of hydrazine monohydrate ( 7.33 mmol), 10 mg of p-toluenesulfonic acid, and 50 ml of toluene were added and heated to reflux for 5 hours. After completion of the reaction, the container was cooled and concentrated under reduced pressure. The residue was purified twice by silica gel column chromatography. Furthermore, the recovered product was recrystallized from toluene / ethyl acetate to obtain 0.939 g (yield 13.7%) of a compound represented by the formula (1-IA).
In mass spectrometry (FD-MS), the peak of M / z = 934 was observed and identified as the target product. In the elemental analysis, the calculated values were 66.81% carbon, 3.67% hydrogen, and 8.99% nitrogen, and the measured values were 66.92% carbon, 3.74% hydrogen, and 9.05% nitrogen.

In the present invention, in addition to these charge transport materials, a charge transport material represented by the above general formula (1-II) can be further added.
Specific examples of the charge transport material represented by the general formula (1-II) include the following compounds.

（ただし、式中、両端の末端基はＭｅ（メチル基）を表す。）

(However, in the formula, the terminal groups at both ends represent Me (methyl group).)

（ただし、式中、両端の末端基はＭｅ（メチル基）を表す。）

(However, in the formula, the terminal groups at both ends represent Me (methyl group).)

  The amount of these charge transport materials to be added is not particularly limited, but is preferably about 1% to 50%, more preferably 5% to 30% with respect to the total amount of the charge transport material. This is because when the addition amount is less than 1%, the film quality improvement is slight and no clear effect is observed, and when the addition amount is 50% or more, the charge transport ability tends to be slightly lowered.

  As the drum-like conductive support used in the present invention, a metal such as aluminum, nickel, chromium, nichrome, copper, silver, gold, platinum, iron, or an oxide such as tin oxide or indium oxide is deposited or sputtered. In particular, a plastic or paper coated with a sheet or cylindrical shape can be exemplified, and more specifically, a plate made of aluminum, aluminum alloy, nickel, stainless steel or the like, or a drawing ironing method, an impact ironing method, an extracted ironing method, or an extended drawing method. For example, it is possible to use a tube or the like which has been subjected to surface treatment by cutting, superfinishing, polishing or the like after forming a raw tube by a construction method such as a cutting method. Among these, a metal having high rigidity is more preferable in terms of ensuring accuracy.

  As the photosensitive layer of the electrophotographic photosensitive member used in the present invention, a single layer type photosensitive layer containing a charge generating substance and a charge transporting substance in a single layer, a charge generating layer containing a charge generating substance and a charge transporting substance are used. Examples thereof include a laminated photosensitive layer in which the contained charge transport layers are laminated in this order.

  The electrophotographic photosensitive member used in the present invention has excellent adhesion, excellent anti-moisture prevention properties, excellent coatability of the upper layer including the photosensitive layer, excellent residual potential reduction property, from the conductive support. An undercoat layer can be provided between the conductive support and the photosensitive layer in view of excellent charge injection prevention.

  The undercoat layer generally comprises a resin as a main component, but these resins are resins having a high solubility resistance to general organic solvents in consideration of applying a photosensitive layer thereon using a solvent. Specifically, water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane, melamine resin, alkyd-melamine resin, and epoxy resin Examples thereof include a curable resin that forms an equal three-dimensional network structure. In addition, the undercoat layer may contain metal oxides such as titanium oxide, silica, alumina, zirconium oxide, tin oxide and indium oxide, or fine powders such as metal sulfides and metal nitrides. The undercoat layer can be applied by using the same coating method and solvent as those for the photosensitive layer described above.

The thickness of the undercoat layer is suitably from 0.1 to 10 μm, more preferably from 1 to 5 μm.
Furthermore, as the undercoat layer, a metal oxide layer formed by a sol-gel method or the like using a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can be exemplified. Furthermore, a layer provided with alumina by anodization, a layer provided with an organic substance such as polyparaxylylene (parylene), an inorganic substance such as silicon oxide, tin oxide, titanium oxide, ITO, etc. by a vacuum thin film preparation method can be used well. Can be illustrated.

Next, examples of each layer structure of the laminated photosensitive layer will be described in detail below.
The charge generation layer is a layer containing a charge generation material, and a binder resin can be used as necessary.
The charge generation material used in the present invention is not particularly limited, but examples thereof include azo pigments and phthalocyanine pigments described in JP-A-9-160269. Among them, phthalocyanine pigments are the present invention. It is particularly preferable from the viewpoint of various properties necessary for the above, and titanyl phthalocyanine having titanium as a central metal can be used as a highly sensitive photosensitive layer, and it can be reduced in size and speed as an electrophotographic apparatus. More preferably, among various crystal forms, titanyl phthalocyanine having a maximum diffraction peak at 27.2 ° with a Bragg angle 2θ exhibits particularly excellent sensitivity characteristics and is used favorably. In particular, it has a maximum diffraction peak at 27.2 ° described in JP-A-2001-19871, and further has main peaks at 9.4 °, 9.6 °, and 24.0 °, Further, by using titanyl phthalocyanine having a peak at 7.3 ° as the diffraction peak on the lowest angle side and having no peak between the 7.4 ° peak and the 9.4 ° peak, Without losing sensitivity, it is possible to obtain a stable electrophotographic photosensitive member that does not cause a decrease in chargeability even when used repeatedly.

  Furthermore, since it is a titanyl phthalocyanine crystal having an average particle size of 0.60 μm or less, it is possible to obtain a stable electrophotographic photosensitive member that does not cause deterioration in chargeability even after repeated use without losing high sensitivity. It can be exemplified that the background dirt characteristics can be remarkably improved.

Examples of the binder resin used for the charge generation layer as needed include polyamide, polyurethane, epoxy resin, polyketone, polycarbonate (pisphenol A type, bisphenol Z type, etc.), polyarylate, silicone resin, acrylic resin, polyvinyl butyral, Examples thereof include polyvinyl formal, polyvinyl ketone, polystyrene, poly-N-vinylcarbazole, and polyacrylamide. These binder resins may be used alone or as a mixture of two or more.
Furthermore, it can also be illustrated that a charge transport material is added as necessary.

As a method for forming the charge generation layer, a casting method from a solution dispersion system is preferable. In order to provide the charge generation layer by the casting method, the above-described charge generation material is dispersed by a ball mill, an attritor, a sand mill or the like using a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, butanone together with a binder resin, if necessary. What is necessary is just to apply | coat after diluting a dispersion liquid moderately. Application can be exemplified by dip coating, spray coating, bead coating, and the like.
The film thickness of the charge generation layer provided as described above is usually 0.01 μm to 5 μm, preferably 0.1 μm to 2 μm.

The charge transport layer used in the present invention can be formed by dissolving or dispersing a mixture of the charge transport material represented by the general formula (1) and the binder resin in an appropriate solvent, and applying and drying the mixture. It can be illustrated.
Examples of the polymer compound that can be used as the binder resin for the charge transport layer include polystyrene, styrene / acrylonitrile copolymer, styrene / butadiene copolymer, styrene / maleic anhydride copolymer, polyester, polyvinyl chloride, and chloride. Vinyl / vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, polyarylate resin, polycarbonate (bisphenol A type, bisphenol Z type), cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, acrylic resin, Examples thereof include thermoplastic resins such as silicone resins, fluororesins, epoxy resins, melamine resins, urethane resins, phenol resins, and alkyd resins, and thermosetting resins. When a layer structure in which the charge transport layer is the outermost layer is used, polycarbonate (bisphenol Z type) is preferable in terms of wear resistance.

The binder resin may be used alone or as a mixture of two or more kinds, or as a copolymer comprising two or more raw material monomers and further copolymerized with a charge transport material.
Furthermore, in order to ensure the stability of the charge transport layer against environmental fluctuations, when using an electrically inactive polymer compound, for example, polyester, polycarbonate (bisphenol A type, bisphenol Z type, etc.), acrylic resin, polystyrene Polyvinyl chloride, polyvinylidene chloride, polyethylene, polypropylene, fluororesin, polyacrylonitrile, acrylonitrile / styrene / butadiene copolymer, styrene / acrylonitrile copolymer, ethylene / vinyl acetate copolymer and the like are preferable. Examples of the electrically inactive polymer compound include polymer compounds that do not contain a chemical structure exhibiting photoconductivity such as a triarylamine structure. When the polymer compound is used in combination with a binder resin as an additive, the addition amount is preferably 50 wt% or less because of limitations on light attenuation sensitivity.

In the present invention, it is essential to use the charge transport material represented by the above general formula (1) as the charge transport material, but in addition to this, a known charge transport material, that is, an electron transport material (acceptor). Alternatively, the combined use of a hole transporting substance (donor) can also be exemplified.
Examples of the electron transporting substance 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- An electron accepting substance such as trinitrodibenzothiophene-5,5-dioxide can be exemplified. The electron transporting substance may be used alone or as a mixture of two or more.

As the hole transporting substance, an electron donating substance is preferably used. Specifically, an oxazole derivative, an oxadiazole derivative, an imidazole derivative, a triphenylamine derivative, 9- (p-diethylaminostyrylanthracene), 1, 1-bis- (4-dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazoline, phenylhydrazones, α-phenylstilbene derivatives, thiazole derivatives, triazole derivatives, phenazine derivatives, acridine derivatives, benzofuran derivatives, benzimidazole derivatives, Examples include thiophene derivatives. The hole transport material can be used alone or as a mixture of two or more.
The charge transport material may be added in an amount of 40 to 200 parts by weight with respect to 100 parts by weight of the resin component, and preferably 70 to 150 parts by weight in that a highly sensitive photoreceptor can be obtained.

The thickness of the charge transport layer is suitably about 15 to 40 μm, preferably about 15 to 30 μm, and when resolution is required, it is preferably 25 μm or more.
Examples of the coating method for the charge transport layer include dipping method, spray coating method, ring coating method, roll coater method, gravure coating method, nozzle coating method and screen printing method.

  Examples of the dispersion solvent that can be used in preparing the charge transport layer coating solution used in the coating method include ketones such as methyl ethyl ketone, acetone, methyl isobutyl ketone, and cyclohexanone, and ethers such as dioxane, tetrahydrofuran, and ethyl cellosolve. And aromatics such as toluene and xylene, halogens such as chlorobenzene and dichloromethane, and esters such as ethyl acetate and butyl acetate. Examples of the dispersion solvent may be used alone or in combination. Furthermore, if necessary, low molecular compounds such as antioxidants, plasticizers, lubricants, ultraviolet absorbers and leveling agents described later may be added to the charge transport layer. It can be exemplified that the low molecular weight compound is used alone or as a mixture of two or more. The amount of the low molecular compound used is 0.1 to 50 parts by weight, preferably 0.1 to 20 parts by weight, based on 100 parts by weight of the polymer compound, and the amount of the leveling agent used is 100 parts by weight of the polymer compound. The amount is preferably about 0.001 to 5 parts by weight.

  Furthermore, known antioxidants, plasticizers and ultraviolet absorbers can be added for the purpose of improving durability and the like within a range not impairing the object of the present invention.

Next, an example of a single-layer type photosensitive layer containing a charge generating substance and a charge transporting substance in the single layer will be described in detail below.
The single-layer type photosensitive layer used in the present invention can be exemplified by a photosensitive layer containing at least a charge generation material and a charge transport material represented by the above formula (1) on a conductive support.
The charge generating material that can be used in the single-layer type photosensitive layer is not particularly limited, and examples thereof include azo pigments and phthalocyanine pigments described in JP-A-9-160269, and among them, phthalocyanine Pigments are particularly preferred from the standpoints of various properties necessary for the present invention, and titanyl phthalocyanine having titanium as a central metal can be used as a highly sensitive photosensitive layer, and the electrophotographic apparatus can be further reduced in size and speed. More preferably, among various crystal forms, titanyl phthalocyanine having a maximum diffraction peak at a Bragg angle 2θ of 27.2 ° exhibits particularly excellent sensitivity characteristics and is used well. . In particular, it has a maximum diffraction peak at 27.2 ° described in JP-A-2001-19871, and further has main peaks at 9.4 °, 9.6 °, and 24.0 °, Further, by using titanyl phthalocyanine having a peak at 7.3 ° as the diffraction peak on the lowest angle side and having no peak between the 7.4 ° peak and the 9.4 ° peak, Without losing sensitivity, it is possible to obtain a stable electrophotographic photosensitive member that does not cause a decrease in chargeability even when used repeatedly.

  Furthermore, since it is a titanyl phthalocyanine crystal having an average particle size of 0.60 μm or less, it is possible to obtain a stable electrophotographic photosensitive member that does not cause deterioration in chargeability even after repeated use without losing high sensitivity. It can be exemplified that the background dirt characteristics can be remarkably improved.

These pigments are preferably dispersed in advance by a ball mill, attritor, sand mill or the like using a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane or butanone. Moreover, dispersing with a binder resin can be exemplified as needed during dispersion.
In the single-layer type photosensitive layer, as the charge transport material used as the charge transport material, it is essential to use the charge transport material represented by the above general formula (1). It is also possible to exemplify the use of a charge transporting material, that is, an electron transporting material (acceptor) and a hole transporting material (donor), as long as the object of the present invention is not impaired.
The charge transport material may be added in an amount of 40 to 200 parts by weight with respect to 100 parts by weight of the binder resin component, and preferably 70 to 150 parts by weight in that a highly sensitive photoreceptor can be obtained.
The film thickness of the single-layer type photosensitive layer is suitably about 15 to 40 μm, preferably about 15 to 30 μm, and when resolution is required, it is preferably 25 μm or more.
Examples of the coating method for the single-layer type photosensitive layer include dipping method, spray coating method, ring coating method, roll coater method, gravure coating method, nozzle coating method and screen printing method.

  Examples of the dispersion solvent that can be used in preparing the charge transport layer coating solution used in the coating method include ketones such as methyl ethyl ketone, acetone, methyl isobutyl ketone, and cyclohexanone, and ethers such as dioxane, tetrahydrofuran, and ethyl cellosolve. And aromatics such as toluene and xylene, halogens such as chlorobenzene and dichloromethane, and esters such as ethyl acetate and butyl acetate. Examples of the dispersion solvent may be used alone or in combination. Furthermore, the addition of low-molecular compounds such as antioxidants, plasticizers, lubricants and ultraviolet absorbers and leveling agents, which will be described later, can be exemplified as required. It can be exemplified that the low molecular weight compound is used alone or as a mixture of two or more. The amount of the low molecular compound used is 0.1 to 50 parts by weight, preferably 0.1 to 20 parts by weight, based on 100 parts by weight of the polymer compound, and the amount of the leveling agent used is 100 parts by weight of the polymer compound. The amount is preferably about 0.001 to 5 parts by weight.

Examples of the present invention and comparative examples will be described below.
[Example 1]
<Production of electrophotographic photoreceptor>
An undercoat layer coating solution, a charge generation layer coating solution, and a charge transport layer coating solution having the following compositions were prepared.

(Coating liquid for undercoat layer)
The following resins and the like were mixed by ball milling (using φ10 mm alumina balls as media) for 5 days in a ball mill apparatus to obtain an undercoat layer coating solution.
11 parts by weight of alkyd resin (Beccosol M-6401-50, manufactured by Dainippon Ink and Chemicals)
Melamine resin 6 parts by weight (Super Becamine G-821-60, manufactured by Dainippon Ink and Chemicals)
48 parts by weight of titanium oxide (CR-EL manufactured by Ishihara Sangyo Co., Ltd.)
185 parts by weight of methyl ethyl ketone (coating solution for charge generation layer)
The resin shown below was mixed with a bead mill disperser (using a PSZ ball having a diameter of 0.5 mm as a medium) for 120 minutes to form a charge generation layer coating solution.
14 parts by weight of metal-free phthalocyanine pigment (Dainippon Ink Industries, Ltd .: Fastogen Blue8120B)
9 parts by weight of polyvinyl butyral (Sekisui Chemical: BX-1)
270 parts by weight of cyclohexanone

(Coating liquid for charge transport layer)
The following resins and the like were stirred and dissolved to obtain a charge transport layer coating solution.
Charge transport material represented by the above formula (2) 9 parts by weight Polycarbonate resin 10 parts by weight (Z polyca, viscosity average molecular weight: 50,000, manufactured by Teijin Chemicals Ltd.)
Tetrahydrofuran 120 parts by weight 1% silicone oil tetrahydrofuran solution 1 part by weight (KF50-100CS Shin-Etsu Chemical Co., Ltd.)
Next, the coating liquid for the undercoat layer and the coating liquid for the charge generation layer are formed on an aluminum drum having a diameter of 30 mm and a length of 340 mm (circular deflection was previously measured and selected within 20 μm). And each coating liquid of the coating liquid for charge transport layers was sequentially applied by a dip coating method to form a film and dried at 135 ° C. for 20 minutes, 80 ° C. for 15 minutes, and 120 ° C. for 20 minutes, respectively. It should be noted that the undercoat layer was fabricated under the ascending / descending speed conditions such that the thickness was 3.5 μm, the charge generation layer was 0.15 μm, and the charge transport layer was 24.3 μm.
The charge transport material represented by the above formula (2) was produced by the following method.

(First step)
In a 200 ml four-necked flask, 5.0 g (18.6 mmol) of 1,4,5,8-naphthalenetetracarboxylic dianhydride and 50 ml of DMF were placed and heated to reflux. To this, a mixture of 2.14 g (18.6 mmol) of 2-aminoheptane and 25 ml of DMF was added dropwise with stirring. After completion of dropping, the mixture was heated to reflux for 6 hours. After completion of the reaction, the container was cooled and concentrated under reduced pressure. Toluene was added to the residue, and the residue was purified by silica gel column chromatography. Furthermore, the recovered product was recrystallized from toluene / hexane to obtain 2.14 g of monoimide A (yield 31.5%).

(Second step)
A 100 ml four-necked flask was charged with 2.0 g (5.47 mmol) of monoimide A, 0.137 g (2.73 mmol) of hydrazine monohydrate, 10 mg of p-toluenesulfonic acid, and 50 ml of toluene, and heated under reflux for 5 hours. I let you. After completion of the reaction, the container was cooled and concentrated under reduced pressure. The residue was purified by silica gel column chromatography. Further, the recovered product was recrystallized from toluene / ethyl acetate to obtain 0.668 g (yield 33.7%) of the charge transport material represented by the formula (2). In mass spectrometry (FD-MS), it was identified as the target product by observing a peak at M / z = 726. In the elemental analysis, the calculated values were 69.52% carbon, 5.27% hydrogen, and 7.71% nitrogen, and the measured values were 69.52% carbon, 5.09% hydrogen, and 7.93% nitrogen.
A flange is fitted to the open ends of the photosensitive member support thus produced, and a 7.8 mm diameter circular hole is provided at the center of each flange, and penetrates the inside of the photosensitive member and each flange. A stainless steel shaft having a diameter of 7.8 mm was attached to obtain a photoreceptor for Example 1.
The photoconductor for Example 1 produced in this way was mounted on a Ricoh IPSiO Color 8100 remodeling machine (with the writing LD wavelength changed to 780 mn and the power pack changed and the charging polarity remodeled for positive charging). Under the following conditions, 50,000 sheets of a full color image in which a rectangular patch and a character with an image area ratio of 6% are mixed are printed continuously. At that time, the initial image and the dark part potential and the bright part after 50,000 sheets are printed. The potential and image quality were evaluated.

The dark part potential, the bright part potential, and the image quality were evaluated as follows.
Dark part potential: After the primary charging, the photosensitive member surface potential when moving to the developing unit position is adjusted. The applied voltage of the charger is adjusted to +700 V in the initial stage, and then the constant voltage is applied until the end of the test. Voltage was used.
・ Bright part potential: after electrification, image exposure (entire exposure), and photoreceptor surface potential and image quality when moved to the development position. Color shift when outputting full color image (output image) Is observed with a magnifying glass, ○ if it is less than 100μm, × if there is a deviation of 100μm or more, the presence or absence of background stains due to uneven charging (when some background stains occur in the white part) X)

[Example 2]
An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that titanyl phthalocyanine prepared according to the synthesis method shown below was used in place of the metal-free phthalocyanine pigment (Fastogen Blue 8120B) as the charge generation material in Example 1. The same evaluation as in Example 1 was performed, and Example 2 was obtained.

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

(X-ray diffraction spectrum measurement conditions)
X-ray tube: Cu
Voltage: 50kV
Current: 30mA
Scanning speed: 2 ° / min Scanning range: 3 ° -40 °
Time constant: 2 seconds When the average particle size in the charge generation layer coating solution using titanyl phthalocyanine was measured with CAPA-700 manufactured by Horiba, it was 0.29 μm.

[Example 3]
The electrophotographic photoreceptor used in Example 3 was produced as follows.
As a charge generation material, a metal-free phthalocyanine pigment (Dainippon Ink Industries Co., Ltd .: Fastogen Blue 8120B) was dispersed with a ball mill apparatus for 2 hours together with 30 parts by weight and 970 parts of cyclohexane non to obtain a charge generation material dispersion. Separately, 340 parts by weight of tetrahydrofuran, 49 parts by weight of polycarbonate resin (Z polycarbonate, viscosity average molecular weight; 40000, manufactured by Teijin Chemicals Ltd.), 20 parts by weight of the charge transport material represented by the above formula (2), the following formula 29.5 parts by weight of the charge transport material represented by (10) and 0.1 part by weight of silicone oil (KF50-100CS manufactured by Shin-Etsu Chemical Co., Ltd.) are dissolved, and 66.6 parts by weight of the above-described charge generation material dispersion liquid are dissolved therein. Part was added and stirred to prepare a photosensitive layer coating solution.

直径３０ｍｍ、長さ３４０ｍｍのアルミニウムドラム（予め円周振れの測定をおこない２０μｍ以内のものを選別したもの）上に、前記感光層塗工液を用いて浸漬塗工をおこない成膜して、乾燥１２０℃で１５分乾燥した。なお感光層は２６．４μｍの厚さとなるような昇降速度条件で作製した。
このようにして作製した電子写真感光体を、実施例１と同様にして評価を行い実施例３とした。

On the aluminum drum having a diameter of 30 mm and a length of 340 mm (circular run-out is measured in advance and selected within 20 μm), dip coating is performed using the photosensitive layer coating solution, followed by drying. It dried at 120 degreeC for 15 minutes. The photosensitive layer was produced under the ascending / descending speed conditions such that the thickness was 26.4 μm.
The electrophotographic photoreceptor thus prepared was evaluated in the same manner as in Example 1 to give Example 3.

[Example 4]
Evaluation was conducted in the same manner as in Example 3 except that the titanyl phthalocyanine used in Example 2 was used in place of the metal-free phthalocyanine pigment (Dainippon Ink Industries, Ltd .: Fastogen Blue 8120B). did.

[Example 5]
Example 5 was evaluated in the same manner as in Example 4 except that the charge transporting material represented by the formula (3) was used instead of the charge transporting material represented by the formula (2) in Example 4. .
The charge transport material represented by the above formula (3) was produced by the following method.

(First step)
In a 200 ml four-necked flask, 10 g (37.3 mmol) of 1,4,5,8-naphthalenetetracarboxylic dianhydride, 0.931 g (18.6 mmol) of hydrazine monohydrate, 20 mg of p-toluenesulfonic acid, 100 ml of toluene And heated to reflux for 5 hours. After completion of the reaction, the container was cooled and concentrated under reduced pressure. The residue was purified by silica gel column chromatography. Further, the recovered product was recrystallized from toluene / ethyl acetate to obtain 2.84 g of dimer C (yield 28.7%).

(Second step)
A 100 ml four-necked flask was charged with 2.5 g (4.67 mmol) of both-bodies C and 30 ml of DMF and heated to reflux. To this, a mixture of 2-aminopropane 0.278 g (4.67 mmol) and DMF 10 ml was added dropwise with stirring. After completion of dropping, the mixture was heated to reflux for 6 hours. After completion of the reaction, the reaction vessel was cooled and concentrated under reduced pressure. Toluene was added to the residue and the residue was purified by silica gel column chromatography to obtain 0.556 g of monoimide C (yield 38.5%).

(Third process)
In a 50 ml four-necked flask, 0.50 g (1.62 mmol) of monoimide C and 10 ml of DMF were placed and heated to reflux. To this, a mixture of 0.186 g (1.62 mmol) of 2-aminoheptane and 5 ml of DMF was added dropwise with stirring. After completion of dropping, the mixture was heated to reflux for 6 hours. After completion of the reaction, the reaction vessel was cooled and concentrated under reduced pressure. Toluene was added to the residue, and the residue was purified by silica gel column chromatography. Further, the recovered product was recrystallized from toluene / hexane to obtain 0.243 g (yield 22.4%) of the charge transport material represented by the above formula (3). In mass spectrometry (FD-MS), the peak of M / z = 670 was observed, and it was identified as the target product. In the elemental analysis, the calculated values were 68.05% carbon, 4.51% hydrogen, and 8.35% nitrogen, and the measured values were 68.29% carbon, 4.72% hydrogen, and 8.33% nitrogen.

[Example 6]
In Example 4, evaluation was performed in the same manner as in Example 4 except that the charge transport material represented by the above formula (4) was used instead of the charge transport material represented by the above formula (2). It was.
The charge transport material represented by the above formula (4) was produced by the following method.

(First step)
In a 200 ml four-necked flask, 5.0 g (18.6 mmol) of 1,4,5,8-naphthalenetetracarboxylic dianhydride and 50 ml of DMF were placed and heated to reflux. To this, a mixture of 1.10 g (18.6 mmol) of 2-aminopropane and 25 ml of DMF was added dropwise with stirring. After completion of dropping, the mixture was heated to reflux for 6 hours. After completion of the reaction, the reaction vessel was cooled and concentrated under reduced pressure. Toluene was added to the residue, and the residue was purified by silica gel column chromatography. Furthermore, the recovered product was recrystallized from toluene / hexane to obtain 2.08 g of monoimide B (yield 36.1%).

(Second step)
A 100 ml four-necked flask was charged with 2.0 g (6.47 mmol) of monoimide B, 0.162 g (3.23 mmol) of hydrazine monohydrate, 10 mg of p-toluenesulfonic acid, and 50 ml of toluene and heated to reflux for 5 hours. . After completion of the reaction, the container was cooled and concentrated under reduced pressure. The residue was purified by silica gel column chromatography. Further, the recovered product was recrystallized from toluene / ethyl acetate to obtain 0.810 g (yield 37.4%) of an electron transport material represented by the formula (4). In mass spectrometry (FD-MS), the peak was identified as M / z = 614, and it was identified as the target product. In the elemental analysis, the calculated values were 66.45% carbon, 3.61% hydrogen, and 9.12% nitrogen, and the measured values were 66.28% carbon, 3.45% hydrogen, and 9.33% nitrogen.

[Example 7]
Example 7 was evaluated in the same manner as in Example 4 except that the charge transporting material represented by the formula (5) was used instead of the charge transporting material represented by the formula (2) in Example 4. .
The charge transport material represented by the above formula (5) was produced by the following method.

(First step)
In a 200 ml four-necked flask, 5.0 g (9.39 mmol) of the above-mentioned dimer C and 50 ml of DMF were placed and heated to reflux. To this, a mixture of 1.08 g (9.39 mmol) DMF 25 ml of 2-aminoheptane was added dropwise with stirring. After completion of dropping, the mixture was heated to reflux for 6 hours. After completion of the reaction, the reaction vessel was cooled and concentrated under reduced pressure. Toluene was added to the residue and purified by silica gel column chromatography to obtain 1.66 g (yield 28.1%) of monoimide D.

(Second step)
A 100 ml four-necked flask was charged with 1.5 g (2.38 mmol) of monoimide D and 50 ml of DMF and heated to reflux. To this, a mixture of 2-aminooctane 0.308 g (2.38 mmol) and DMF 10 ml was added dropwise with stirring. After completion of dropping, the mixture was heated to reflux for 6 hours. After completion of the reaction, the reaction vessel was cooled and concentrated under reduced pressure. Toluene was added to the residue, and the residue was purified by silica gel column chromatography. Further, the recovered product was recrystallized from toluene / hexane to obtain 0.328 g (yield 18.6%) of the charge transport material represented by the formula (5). In mass spectrometry (FD-MS), the peak was identified as M / z = 740, and it was identified as the target product. In the elemental analysis, the calculated values were 69.72% carbon, 5.44% hydrogen, and 7.56% nitrogen, and the measured values were 69.55% carbon, 5.26% hydrogen, and 7.33% nitrogen.

[Example 8]
Example 8 was evaluated in the same manner as in Example 4 except that the charge transporting material represented by the formula (6) described above was used instead of the charge transporting material represented by the formula (2) in Example 4. .
The charge transport material represented by the above formula (6) was produced by the following method.

(First step)
In a 200 ml four-necked flask, 5.0 g (9.39 mmol) of the above-mentioned dimer C and 50 ml of DMF were placed and heated to reflux. To this, a mixture of 1.08 g (9.39 mmol) DMF 25 ml of 2-aminoheptane was added dropwise with stirring. After completion of dropping, the mixture was heated to reflux for 6 hours. After completion of the reaction, the reaction vessel was cooled and concentrated under reduced pressure. Toluene was added to the residue and purified by silica gel column chromatography to obtain 1.66 g (yield 28.1%) of monoimide D.

(Second step)
A 100 ml four-necked flask was charged with 1.5 g (2.38 mmol) of monoimide D and 50 ml of DMF and heated to reflux. To this, a mixture of 0.408 g (2.38 mmol) of 6-aminoundecane and 10 ml of DMF was added dropwise with stirring. After completion of dropping, the mixture was heated to reflux for 6 hours. After completion of the reaction, the reaction vessel was cooled and concentrated under reduced pressure. Toluene was added to the residue, and the residue was purified by silica gel column chromatography. Further, the recovered product was recrystallized from toluene / hexane to obtain 0.276 g (yield 14.8%) of the charge transport material represented by the above formula (6). In mass spectrometry (FD-MS), the peak of M / z = 782 was observed and identified as the target product. In the elemental analysis, the calculated values were 70.77% carbon, 6.11% hydrogen, and 7.02% nitrogen while the calculated values were 70.57% carbon, 5.92% hydrogen, and 7.16% nitrogen.

[Example 9]
Example 9 was evaluated in the same manner as in Example 4 except that the charge transport material represented by formula (1-IA) was used instead of the charge transport material represented by formula (2) in Example 4. .

ただし、式中、両端の末端基はＭｅ（メチル基）を表す。

However, in the formula, the terminal groups at both ends represent Me (methyl group).

[Example 10]
Example 10 was evaluated in the same manner as in Example 4 except that the charge transport material represented by formula (1-IB) was used instead of the charge transport material represented by formula (2) in Example 4. .

ただし、式中、両端の末端基はＭｅ（メチル基）を表す。

However, in the formula, the terminal groups at both ends represent Me (methyl group).

[Example 11]
Example 11 was evaluated in the same manner as in Example 4 except that the charge transport material represented by formula (1-IC) was used instead of the charge transport material represented by formula (2) in Example 4. .
(In the formula, n_ is a mixture of numerical values from 1 to 100.)

ただし、式中、両端の末端基はＭｅ（メチル基）を表す。

However, in the formula, the terminal groups at both ends represent Me (methyl group).

[Example 12]
Evaluation was conducted in the same manner as in Example 4 except that 15 parts of the charge transport material represented by the formula (2) in Example 4 and 5 parts of the charge transport material represented by the following formula (1-IIA) were newly added. To make Example 12.

ただし、式中、両端の末端基はＭｅ（メチル基）を表す。

However, in the formula, the terminal groups at both ends represent Me (methyl group).

[Example 13]
In Example 4, a circular hole having a diameter of 4.2 mm is provided in the center of each flange, and a stainless steel shaft having a diameter of 4.2 mm passing through the inside of the photoreceptor and each flange is mounted. Evaluation was carried out in the same manner as in Example 4 to give Example 13.

[Example 14]
In Example 4, a circular hole having a diameter of 18.0 mm is provided in the center of each flange, and a stainless steel shaft having a diameter of 18.0 mm passing through the inside of the photoreceptor and each flange is mounted. Evaluation was carried out in the same manner as in Example 4 to give Example 14.

[Example 15]
Example 15 was evaluated in the same manner as in Example 4 except that the stainless steel shaft was changed to aluminum and mounted.

[Example 16]
Example 4 is the same as Example 4 except that the charging member is changed to a corona charging method in which a high voltage of −6 kV is applied and replaced with a tungsten wire with a diameter of 40 to 80 μm arranged in a shield case. Evaluation was made to be Example 16.

[Comparative Example 1]
In Example 4, the evaluation was made in the same manner as in Example 4 except that the shaft was not attached to the photoreceptor.

[Comparative Example 2]
Comparative Example 2 was evaluated in the same manner as in Example 4 except that a shaft was not mounted and a butyl rubber filler (damping material) was inserted in close contact with the interior of the photoreceptor. .

[Comparative Example 3]
Comparative Example 3 was evaluated in the same manner as in Example 4 except that the shaft was not mounted in Example 4 and a filler (damping material) made of ABS was placed in close contact with the inside of the photoreceptor. .

[Comparative Example 4]
A comparative example was evaluated in the same manner as in Example 1 except that the charge transport material represented by the following formula (11) was used instead of the charge transport material represented by the formula (2) used in the photosensitive layer in Example 1. It was set to 4.

[Comparative Example 5]
A comparative example was evaluated in the same manner as in Example 3 except that the charge transport material represented by the formula (11) used in the photosensitive layer in Example 3 was replaced with the charge transport material represented by the formula (11). It was set to 5.

[Comparative Example 6]
A comparative example was evaluated in the same manner as in Example 4 except that the charge transport material represented by the following formula (12) was used instead of the charge transport material represented by the formula (2) used in the photosensitive layer in Example 4. It was set to 5.

実施例１〜１６、比較例１〜６の評価結果を表１に示す。

Table 1 shows the evaluation results of Examples 1 to 16 and Comparative Examples 1 to 6.

表１から、本発明の構成要件を満たす実施例ではフルカラー画像出力時において色ズレもなく、且つ帯電音の音量の低減が見られ、帯電不良による地汚れや帯電ローラ汚れに起因する異常画像の発生もない高画質な画像を安定して得られることが確認された。
本発明の要件を満たしていない比較例は色ズレ発生、明部電位上昇による画像濃度低下などの異常画像の発生が発生する。

Table 1 shows that in the examples satisfying the constitutional requirements of the present invention, there is no color misregistration at the time of full-color image output and the volume of the charging sound is reduced, and abnormal images caused by ground contamination due to charging failure or charging roller contamination are observed. It was confirmed that high-quality images with no occurrence could be obtained stably.
In the comparative example that does not satisfy the requirements of the present invention, the occurrence of abnormal images such as color misregistration and image density reduction due to bright portion potential increase occurs.

1 is a schematic diagram for explaining an example of an image forming apparatus of the present invention. It is another figure for demonstrating the example of the image forming apparatus of this invention. FIG. 6 is still another diagram for explaining an example of the image forming apparatus of the present invention. 1 is a schematic cross-sectional view of an electrophotographic photosensitive member provided in an image forming apparatus of the present invention. 4 is another configuration example of an electrophotographic photoreceptor provided in the image forming apparatus of the present invention. 7 is still another configuration example of the electrophotographic photosensitive member provided in the image forming apparatus of the present invention.

Explanation of symbols

1A Charger 1C Photoconductor 1M Photoconductor 1Y Photoconductor 1K Photoconductor 2C Charging member 2M Charging member 2Y Charging member 2K Charging member 3C Laser beam 3M Laser beam 3Y Laser beam 3K Laser beam 4C Developing member 4M Developing member 4Y Developing member 4K Developing Member 5C Cleaning device 5M Cleaning device 5Y Cleaning device 5K Cleaning device 6C Image forming element 6M Image forming element 6Y Image forming element 6K Image forming element 7 Transfer paper 8 Rolling roller 9 Registration roller 10 Transfer conveying belt 11 Photoconductor 11C Transfer brush 11M Transfer brush 11Y Transfer brush 11K Transfer brush 12 Fixing device 13 Exposure means 13C Shaft 13M Shaft 13Y Shaft 13K Shaft 14 Developing means 15 Toner 16 Transfer means 17 Cleaning means 18 Image receiving medium 19 Shaft (through) Axis)
G Gap 22 Charging member

Claims (6)

At least a photosensitive member provided with a photosensitive layer on a drum-shaped conductive support, a charging means for uniformly charging the photosensitive member, and image exposure for performing image exposure after uniform charging to form an electrostatic latent image An image forming apparatus comprising: an image forming unit including: a developing unit that develops toner on the electrostatic latent image; a unit that transfers the developed image; and a cleaning unit that cleans residual transfer toner on the electrophotographic photosensitive member. The photosensitive layer of the photosensitive member contains at least one kind of charge transporting material represented by the following formulas (a) to (g) , and the photosensitive member has a drum-shaped supporting part and both ends of the supporting part. A flange having a pair of bearing holes respectively fitted to the release portion; and a shaft that is fixed to the center of each flange at both ends and penetrates the support and forms a rotation center axis. Do Image forming apparatus.

2. The image forming apparatus according to claim 1 , wherein a diameter L of the shaft satisfies a relationship of 3 mm ≦ L ≦ 20 mm in at least a part of the longitudinal direction. The image forming apparatus according to claim 1 or 2, wherein the shaft is made of metal. The image forming apparatus according to any one of claims 1 to 3, wherein the shaft is made of stainless steel. At least charging means, exposing means, developing unit, and includes a one and an electrophotographic photosensitive member of the transfer means, used in an image forming apparatus according to any one of claims 1 to 4, the process cartridge is detachable . The image forming apparatus includes an intermediate transfer unit that primarily transfers a toner image developed on an electrophotographic photosensitive member onto an intermediate transfer member and then secondary-transfers the toner image on the intermediate transfer member onto a recording material. an image forming apparatus, an image forming apparatus according to any one of claims 1 to 4, characterized in that secondarily transferred collectively toner images of a plurality of colors on the recording material.

Images