JP5725890B2 - Electrophotographic equipment - Google Patents

Description

  The present invention relates to an electrophotographic apparatus having an electrophotographic photosensitive member.

As an electrophotographic photosensitive member mounted on an electrophotographic apparatus, there is an electrophotographic photosensitive member (organic electrophotographic photosensitive member) containing an organic photoconductive substance. In the electrophotographic process, processes such as a charging unit, an exposing unit, a cleaning unit, and a discharging unit are involved in the electrophotographic photosensitive member.
As charging means, there are methods such as charging with discharge, frictional charging, and injection charging. The charging method with discharge is excellent in uniformity of charging and is widely used. However, charging with discharge generates active gas (nitrogen oxide, ozone), adheres to the surface of the electrophotographic photosensitive member, and deteriorates the electrophotographic photosensitive member, thereby generating an image defect called a black belt. . The black belt is a phenomenon in which an output image has a black belt-like density difference, and is one of image defects due to a memory phenomenon. This black belt is a reversal development method. When the electrophotographic apparatus is stopped for several hours after completion of the electrophotographic process, the portion of the electrophotographic photosensitive member facing the charger changes in quality and the output image is again formed during image formation. This is a phenomenon in which the portion corresponding to the position of the charger becomes darker than the surrounding area.

  In particular, in recent years, the generation of active gas has increased as the speed of the electrophotographic process has increased, the output of the charger has been improved, and the time of the charging means has been shortened. Yes.

  In order to improve the black belt, it has been proposed to add an additive to the photosensitive layer. Patent Documents 1 and 2 propose an electrophotographic photosensitive member that contains a plurality of additives in the photosensitive layer and surface layer of the electrophotographic photosensitive member to suppress the occurrence of black bands due to active gas. Patent Document 3 proposes an electrophotographic photosensitive member that contains an additive having a pyridine structure in the surface layer of the electrophotographic photosensitive member to suppress the occurrence of black belts. Further, in the cited document 4, it is proposed to suppress the deterioration of the electrophotographic photosensitive member due to the active gas by including a urea derivative in the photosensitive layer.

JP-A-6-095404 JP 2001-356501 A JP 2006-064954 A JP 63-097959 A

However, in an electrophotographic photosensitive member containing an additive, charges are easily trapped by the additive, so that a density difference between the exposed area and the non-exposed area (image density difference between the exposed area and the non-exposed area) is likely to occur. In the electrophotographic photoconductors of Cited Documents 1 to 3, when an electrophotographic apparatus having an improved charger output is used, both improvement of the black belt and suppression of the density difference between the exposed portion and the non-exposed portion can be sufficiently achieved. There wasn't. In the electrophotographic photosensitive member of Cited Document 4, the occurrence of a black belt is suppressed. However, as a result of investigations by the present inventors, it has been found that there is room for further improvement in suppressing the density difference between the exposed portion and the non-exposed portion.
An object of the present invention is an electrophotographic apparatus having a charging means for charging an electrophotographic photosensitive member by a charging method with discharge, which is compatible with improvement of a black belt and suppression of a density difference between an exposed area and an unexposed area. An object of the present invention is to provide an electrophotographic apparatus having a photoreceptor.

The present invention relates to an electrophotographic apparatus having a charging means for charging an electrophotographic photosensitive member by a charging method with discharge, wherein the electrophotographic photosensitive member used in the electrophotographic apparatus includes a support and a charge formed on the support. The generation layer has a charge transport layer formed on the charge generation layer, and the charge generation layer and at least one of the layers located on the surface side of the electrophotographic photoreceptor relative to the charge generation layer have the following: The present invention relates to an electrophotographic apparatus comprising a compound having a structure represented by formula (1). (However, when the electrophotographic apparatus further includes means for supplying basic particles having a number average particle size of 30 to 500 nm to a portion where the surface of the electrophotographic photosensitive member is in contact with the cleaning blade, and (Except when the developing means of the apparatus has a developer containing basic particles having a number average particle diameter of 30 to 500 nm.)

In formula (1), X represents an oxygen atom or a sulfur atom. R ¹ and R ² each independently represents an alkyl group having 1 to 3 carbon atoms. Ar ¹ and Ar ² each independently represent a substituted or unsubstituted aryl group. However, the substituent that the aryl group may have includes a carboxyl group, a cyano group, a substituted or unsubstituted amino group, a hydroxyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkyl group, a nitro group, Or it is a halogen atom.

  According to the present invention, in an electrophotographic apparatus having a charging means for charging an electrophotographic photosensitive member by a charging method that accompanies discharge, an electrophotographic process that achieves both improvement of a black belt and suppression of a density difference between an exposed area and an unexposed area. An electrophotographic apparatus having a photoreceptor can be provided.

It is a figure which shows an example of the laminated constitution of the electrophotographic photoreceptor used for the electrophotographic apparatus of this invention. It is a figure which shows an example of schematic structure of the electrophotographic apparatus of this invention. It is a figure for demonstrating the printing for density difference evaluation of the exposure part and non-exposure part used in the case of the image density difference of an exposure part and a non-exposure part.

  As described above, the electrophotographic apparatus of the present invention is an electrophotographic apparatus having a charging means for charging the electrophotographic photosensitive member by a charging method with discharge, wherein the electrophotographic photosensitive member used in the electrophotographic apparatus is a support, A charge generation layer formed on the support, a charge transport layer formed on the charge generation layer, and at least of the charge generation layer and the layer located on the surface of the electrophotographic photoreceptor from the charge generation layer, One or more layers contain a compound having a structure represented by the formula (1). Thereby, it is possible to achieve both improvement of the black belt and suppression of the density difference between the exposed portion and the non-exposed portion.

The inventors presume the reason why the electrophotographic apparatus of the present invention can achieve both the improvement of the black belt and the density difference between the exposed portion and the non-exposed portion as follows.
In the present invention, the black belt is considered to be caused by the high photosensitivity of the portion of the electrophotographic photosensitive member facing the charger. This is presumed to be caused by the fact that the active gas such as nitrogen oxide generated acts on the charge generation layer to increase the photosensitivity.
In the present invention, it is presumed that the compound having the structure represented by the formula (1) improves the black band by inclusion of the compound derived from the active gas to form an inclusion compound. Further, it is known that ammonia generated by decomposition of a compound having a structure represented by the formula (1) reduces nitrogen oxides generated by the active gas to water and nitrogen. For these reasons, it is presumed that the additive of the present invention can exert an excellent effect on the improvement of the black belt.
In the present invention, the density difference between the exposed portion and the non-exposed portion is, for example, in a reversal development type electrophotographic apparatus, a portion that is not irradiated with light and a portion that is irradiated with light (exposure portion) in one image. ) Is a phenomenon in which a difference in image density occurs between the exposed portion and the non-exposed portion when image formation that becomes a halftone image is performed at the next rotation. This is considered to be caused by the fact that the charging potential of the exposed portion and the non-exposed portion is not uniform in the charging means at the next rotation.

  One reason for this is that the charge transfer rate is lowered by the additive that suppresses the active gas in the electrophotographic photosensitive member. If the charge transfer rate decreases, it takes time to remove the charge. Since the next charging is performed in the non-exposed portion without sufficient charge removal, the charging potential is lowered. On the other hand, since the next charging is performed after the exposure portion has been sufficiently discharged, it has a predetermined charging potential. As a result, the charged potential is not uniform, and an image density difference between the exposed portion and the non-exposed portion occurs during the next image formation.

When the compound having the structure represented by the formula (1) was subjected to structural analysis by semi-empirical quantum mechanical calculation by MOPAC (trade name: manufactured by CS Chem 3D Ultra CambridgeSoft), an aryl group in the formula (1) ( Ar ¹ and Ar ² ) are reduced in distance (a structure in which aryl groups face each other). On the other hand, in the compound in which the arrangement of R ¹ , R ² , Ar ¹ , Ar ² is different from the formula (1), the aryl groups do not face each other.

  In the charge transfer of the electrophotographic photoreceptor (organic electrophotographic photoreceptor), the distance between the charge transport materials is important because the charge transport occurs by hopping between the charge transport materials. When an additive is added to the electrophotographic photosensitive member coating solution, the type and amount of the additive are selected so that precipitation does not occur, and the compatibility is studied. In a photosensitive layer containing a conventionally used additive, even if precipitation does not occur, the presence of minute aggregates of additive molecules increases the distance between charge transport materials and charges hopping. Is thought to be inhibited. However, in the compound having the structure represented by the formula (1) of the present invention, the aryl groups face each other, so that the compatibility with the coating solution for an electrophotographic photosensitive member is improved, and a fine molecular assembly is formed. Not. As a result, it is assumed that the decrease in the movement speed of the charge can be suppressed and the density difference between the exposed part and the non-exposed part is improved.

  On the other hand, among the urea compounds disclosed in JP-A-63-097959, those having an aryl group have a structure in which a hydrogen atom is bonded to a nitrogen atom. Therefore, it is presumed that the aryl groups do not face each other, and no improvement in compatibility with the electrophotographic photoreceptor coating solution is observed. Therefore, it is considered that the reduction of the charge transfer speed is insufficient, and the density difference between the exposed part and the non-exposed part is not sufficiently suppressed.

The electrophotographic photosensitive member used in the present invention has a support, a charge generation layer formed on the support, and a charge transport layer formed on the charge generation layer.
In the present invention, a conductive layer containing conductive fine particles may be provided on the support for the purpose of covering scratches or protrusions of the support or suppressing interference fringes (moire). . In the electrophotographic photoreceptor of the present invention, an intermediate layer may be provided between the support or conductive layer and the charge generation layer for the purpose of providing an electrical blocking function. The charge generation layer and the charge transport layer may have a laminated structure.

  FIG. 1 (FIGS. 1A and 1B) is a view showing an example of the layer structure of the electrophotographic photosensitive member used in the present invention. In FIG. 1, 101 is a support, 102 is an intermediate layer, 103 is a charge generation layer, 104 is a charge transport layer, and 105 is a protective layer. In addition, the electrophotographic photosensitive member used in the present invention may have any layer configuration shown in FIG. 1 (a) or (b). Further, the protective layer 105 may have a charge transport capability.

  The electrophotographic photosensitive member used in the electrophotographic apparatus of the present invention has a support, a charge generation layer formed on the support, and a charge transport layer formed on the charge generation layer. Among the layers located on the surface side of the electrophotographic photoreceptor from the layer, at least one layer is an electrophotographic photoreceptor containing a compound having a structure represented by the formula (1). Examples of the layer positioned closer to the surface of the electrophotographic photoreceptor than the charge generation layer include a charge transport layer and a protective layer.

  Furthermore, the electrophotographic photosensitive member used in the electrophotographic apparatus of the present invention has a protective layer formed on the charge transport layer, and at least one of the charge transport layer and the protective layer is represented by the formula (1). An electrophotographic photoreceptor containing a compound having a structure is preferable. The black belt is considered to be a phenomenon in which the active gas moves toward the charge generation layer, reaches the charge generation layer, and alters the charge generation layer. For this reason, it is preferable to contain the compound which has a structure shown by Formula (1) in at least one layer of a charge transport layer and a protective layer.

  Next, the compound having the structure represented by the formula (1) will be described.

In formula (1), X represents an oxygen atom or a sulfur atom. R ¹ and R ² each independently represents an alkyl group having 1 to 3 carbon atoms. Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, and a propyl group (n-propyl group, isopropyl group). Ar ¹ and Ar ² each independently represent a substituted or unsubstituted aryl group. Examples of the substituted or unsubstituted aryl group include a phenyl group, a biphenyl group, and a polycyclic aromatic hydrocarbon group. Examples of the polycyclic aromatic hydrocarbon group include a naphthyl group, a fluorene group, and a 9,9-dimethylfluorene group. Further, the substituent which the substituted or unsubstituted aryl group may have is a carboxyl group, a cyano group, a substituted or unsubstituted amino group, a hydroxyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkyl group. , A nitro group, or a halogen atom. Examples of the substituted amino group (amino group having a substituent) include a dimethylamino group and a diethylamino group. Examples of the substituted or unsubstituted alkoxy group include a methoxy group and an ethoxy group. Examples of the substituted or unsubstituted alkyl group include a methyl group, an ethyl group, a propyl group (n-propyl group, isopropyl group), a trifluoromethyl group, and the like. Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom.

Moreover, from the point that it is easy to take the arrangement where the aryl groups in the molecule face each other, R ¹ and R ² in the above formula (1) are the same groups in the compound having the structure represented by the above general formula (1). And preferably a symmetrical structure in which Ar ¹ and Ar ² are the same group.
In the present invention, the layer containing the compound having the structure represented by the formula (1) contains 1% by mass or more of the compound having the structure represented by the formula (1) based on the total mass of the layer. It is preferable to contain it by mass% or less. When there is too little content, the suppression effect of the density | concentration difference of an exposed part and a non-exposed part may not be enough. Moreover, when there is too much content, the compound which has a structure shown by the said Formula (1) may become easy to precipitate.

The compound which has a structure shown by the said Formula (1) may contain only 1 type, and may contain 2 or more types.
The compound having the structure represented by the above formula (1) can be synthesized, for example, using a synthesis method described in the following literature.
-Photochem. Photobiol. Sci. , 2002, 1, 30-37
・ Transactions of the Faraday Society, 34, 1938, 783-786
Tetrahedron Letters 39 (1998) 6267-6270
Bulletin of the chemical society of Japan, vol. 47 (4), 1974, 935-937.

  Although the specific example (exemplary compound) of the compound which has a structure shown by the said Formula (1) below is given, this invention is not necessarily limited to these.

Among the compounds, the structural formulas (U-1), (U-2), (U-3), (U-4), (U-10), (U-19), (U-24), The compounds represented by (U-25) and (U-26) are more preferred. Hereinafter, the structural formulas (U-1) to (U-48) are also referred to as exemplary compounds (U-1) to (U-48).
Next, the configuration of the electrophotographic photosensitive member used in the present invention will be described.

[Support]
The support used in the electrophotographic photosensitive member of the present invention is preferably one having conductivity (conductive support), and examples thereof include metals or alloys such as iron, copper, gold, aluminum, nickel, and stainless steel. Further, there may be mentioned those obtained by forming a thin film of a metal such as aluminum, silver or gold or a conductive material such as indium oxide or tin oxide on an insulating support of polyester or polycarbonate. A support in which conductive particles such as carbon black, tin oxide particles, titanium oxide particles, and silver particles are impregnated in a resin, or a plastic having a conductive binder resin can also be used. Examples of the shape of the conductive support include a cylindrical shape and a belt shape, and a cylindrical shape is preferable.

In order to suppress interference fringes, it is preferable that the surface of the support is moderately roughened. Specifically, it is preferable to use a support that has been subjected to cutting treatment, roughening treatment, and alumite treatment.
In the electrophotographic photosensitive member of the present invention, a conductive layer having conductive particles and a resin may be provided on the support. In the method of forming a conductive layer having conductive particles and a resin on a support, a powder containing conductive particles is contained in the conductive layer. Examples of the conductive particles include powders of metals and alloys such as carbon black, acetylene black, aluminum, zinc, copper, chromium, nickel and silver, and metal oxide powders such as tin oxide and ITO.
Examples of the resin used for the conductive layer include acrylic resin, alkyd resin, epoxy resin, phenol resin, butyral resin, polyacetal, polyurethane, polyester, polycarbonate, and melamine resin.
Examples of the solvent used for the conductive layer coating solution include ether solvents, alcohol solvents, ketone solvents, and aromatic hydrocarbon solvents. The thickness of the conductive layer is preferably 0.2 μm or more and 40 μm or less, and more preferably 5 μm or more and 40 μm or less.
In the electrophotographic photosensitive member of the present invention, an intermediate layer may be provided between the support or conductive layer and the charge generation layer.

The intermediate layer can be formed by applying a coating liquid for intermediate layer containing a resin on a support or a conductive layer, and drying or curing it.
Examples of the resin used for the intermediate layer include polyacrylic acids, polyvinyl alcohol, ethyl cellulose, polyamide, polyamideimide, polyamic acid, melamine resin, epoxy resin, and polyurethane. Moreover, the above-mentioned electroconductive particle can also be contained in an intermediate | middle layer. The thickness of the intermediate layer is preferably 0.05 μm or more and 40 μm or less, and more preferably 0.1 μm or more and 30 μm or less. Further, the intermediate layer may contain semiconductive particles, an electron transporting material, or an electron accepting material.

(Charge generation layer)
In the electrophotographic photoreceptor of the present invention, a charge generation layer is provided on the support, the conductive layer or the intermediate layer. The charge generation layer can be formed by applying a charge generation layer coating solution obtained by dispersing a charge generation material together with a resin and a solvent and drying the coating solution. The charge generation layer may be a vapor generation film of a charge generation material.
Examples of the charge generating material used in the electrophotographic photoreceptor of the present invention include azo pigments, phthalocyanine pigments, indigo pigments, and perylene pigments. These charge generation materials may be used alone or in combination of two or more. Among these, gallium phthalocyanine exhibits excellent charge generation efficiency. Furthermore, from the viewpoint of potential characteristics (sensitivity and environmental fluctuation), crystalline hydroxygallium having strong peaks at 7.4 ° and 28.2 ° of the Bragg angle (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction A phthalocyanine crystal is more preferable.
Examples of the resin used for the charge generation layer include polyvinyl butyral, polyarylate, polycarbonate, polyester, polyvinyl acetate, acrylic resin, cellulose resin, and urethane resin. These resins can be used alone or in combination of two or more as a mixture or a copolymer.
Examples of the solvent used in the charge generation layer coating solution include alcohol solvents, sulfoxide solvents, Teton solvents, ether solvents, ester solvents, and aromatic hydrocarbon solvents.
The thickness of the charge generation layer is preferably 0.05 μm or more and 5 μm or less. The charge generation layer may contain a sensitizer, a leveling agent, a dispersant, an antioxidant, an ultraviolet absorber, a plasticizer, an electron transport material, and the like.

(Charge transport layer)
In the electrophotographic photoreceptor of the present invention, a charge transport layer is provided on the charge generation layer. The charge transport layer can be formed by applying a charge transport layer coating solution obtained by dispersing a charge transport material together with a resin and a solvent, and drying it. The charge transport layer can also be provided as two or more charge transport layers that are functionally separated.
Examples of the charge transport material used in the electrophotographic photoreceptor of the present invention include a triarylamine compound, a hydrazone compound, a stilbene compound, a pyrazoline compound, an oxazole compound, a thiazole compound, and a triallylmethane compound. These charge transport materials may be used alone or in combination of two or more.
Examples of the resin used for the charge transport layer include polyvinyl butyral, polyarylate, polycarbonate, polyester, and polystyrene. Further, a compound having a charge transport function introduced into the main chain or side chain of these resins to form a polymer charge transport material can also be used.
Examples of the solvent used for the charge transport layer coating solution include alcohol solvents, sulfoxide solvents, Teton solvents, ether solvents, ester solvents, and aromatic hydrocarbon solvents.
The thickness of the charge transport layer is preferably 5 μm or more and 40 μm or less. The charge transport layer may contain fluorine atom-containing fine particles or silicone-containing resin. Moreover, you may contain the microparticles | fine-particles comprised by the said resin, a metal oxide microparticle, and an inorganic microparticle. Moreover, you may contain a leveling agent, a dispersing agent, antioxidant, a ultraviolet absorber, a plasticizer, etc. as needed.

A protective layer may be provided as necessary on the charge transport layer in the electrophotographic photoreceptor of the present invention. The protective layer can be formed by applying a protective layer coating solution obtained by dissolving a resin and, if necessary, a charge transport material in a solvent, and drying the coating solution.
The resin used for the protective layer is from the viewpoint of the mechanical strength of the electrophotographic photosensitive member. Among the resins used for the above-described charge transport layer, it is preferable to use a resin having a large molecular weight, a resin having an aryl group in the main chain, or a curable resin. The curable resin is generally composed of a polymerized or crosslinkable monomer or oligomer. Examples of the curable resin monomer or oligomer include a monomer or oligomer having a chain polymerizable functional group such as an acryloyloxy group or a styrene group, and a monomer or oligomer having a sequentially polymerizable functional group having a hydroxyl group or an isocyanate group. As the curing means, heat, light, radiation (such as an electron beam) can be used.
As the charge transport material used in the protective layer, the same charge transport materials as those used in the charge transport layer described above can be used. Moreover, the resin used for the protective layer may have a skeleton that retains charge transport performance. When a curable resin is used, a monomer or oligomer having a skeleton that retains charge transport performance is used.
Examples of the solvent used in the protective layer coating solution include alcohol solvents, sulfoxide solvents, Teton solvents, ether solvents, ester solvents, and aromatic hydrocarbon solvents.
The protective layer may contain fluorine atom-containing fine particles or metal oxide fine particles for the purpose of improving friction resistance and mechanical strength. Specific examples include fluorine atom-containing resin particles such as tetrafluoroethylene resin particles, metal oxide particles such as silica, alumina, and tin oxide. Moreover, you may contain a leveling agent, a dispersing agent, antioxidant, a ultraviolet absorber, a plasticizer, etc.
The thickness of the protective layer is preferably 0.5 μm or more and 20 μm or less.

  When applying the coating liquid for each of the above layers, a coating method such as a dip coating method (dip coating method), a spray coating method, a spinner coating method, a bead coating method, a blade coating method, or a beam coating method can be used.

FIG. 2 shows an example of a schematic configuration of the electrophotographic apparatus of the present invention.
In FIG. 2, reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member, which is rotationally driven with a predetermined peripheral speed (process speed) in the direction of an arrow about the shaft 2. In the rotating process, the electrophotographic photosensitive member 1 is uniformly charged with a negative predetermined potential on its peripheral surface by a charging means (charging device / primary charging means) 3. The charging means in the present invention is a charging system with discharge, and FIG. 2 shows a corotron as an example. Next, the exposure light 4 intensity-modulated in response to a time-series electric digital image signal of target image information output from an exposure means (not shown) such as slit exposure or laser beam scanning exposure is received. In this way, electrostatic latent images corresponding to target image information are sequentially formed on the surface of the electrophotographic photosensitive member 1.

  The formed electrostatic latent image is then visualized as a toner image by reversal development with toner stored in the developing means 5. The toner image formed and supported on the surface of the electrophotographic photosensitive member 1 is sequentially transferred to the intermediate transfer member 7 by the primary transfer unit 6. At this time, a bias voltage having a polarity opposite to the charge held in the toner is applied to the primary transfer unit 6 from a bias power source (not shown). The toner image transferred to the intermediate transfer member 7 is sequentially transferred to the transfer material 9 by the secondary transfer unit 8. At this time, a bias having a polarity opposite to the toner holding charge is applied to the secondary transfer unit 8 from a bias power source (not shown). Further, the transfer means may be a system in which the toner image is directly transferred from the electrophotographic photosensitive member 1 to the transfer material 9 without using the intermediate transfer system having the intermediate transfer body and the secondary transfer means.

The transfer material 9 that has received the transfer of the toner image is conveyed to a fixing means (not shown), and is subjected to a fixing process of the toner image to be printed out as an image formed product (print, copy) outside the electrophotographic apparatus. .
The surface of the electrophotographic photosensitive member 1 after the transfer of the toner image is cleaned by removing the adhered matter such as transfer residual toner by the cleaning means 10. Next, after being subjected to charge removal processing by the pre-exposure light 12 from the pre-exposure means 11, it is repeatedly used for image formation.

  In the present invention, a plurality of components such as the electrophotographic photosensitive member 1, the charging unit 3, the developing unit 5, the transfer unit 6, and the cleaning unit 10 may be housed in a container to form a process cartridge. The process cartridge may be detachably attached to an electrophotographic apparatus main body such as a copying machine or a laser beam printer.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. In the examples, “part” means “part by mass”.

<Example 1>
An aluminum cylinder (JIS A3003) having a length of 370 mm and a diameter of 84 mm was cut and used as a support. Next, 57 parts of SnO ₂ coated barium sulfate particles (trade name: Pastoran LRS, manufactured by Mitsui Mining & Smelting Co., Ltd.), resol type phenol resin (trade name: Phenolite J-325, Dainippon Ink & Chemicals, Inc.) A mixed solvent of 21 parts and 19 parts of 2-methoxy-1-propanol was dispersed with a ball mill for 8 hours to obtain a dispersion. To this dispersion, 1.48 parts of silicone resin (trade name: Tospearl 120, manufactured by Toshiba Silicone Co., Ltd.), 1.48 parts of 2-methoxy-1-propanol, silicone oil (trade name: SH28PA, Toray Silicone Co., Ltd.) ) Made) 0.008 part was mixed to prepare a coating solution for a conductive layer. This conductive layer coating solution was dip-coated on the aluminum cylinder, and this was heat-cured at 150 ° C. for 30 minutes to form a conductive layer having a thickness of 15 μm.

  Next, 40 parts of methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corp.) is dissolved in a mixed solvent of 400 parts of methanol and 200 parts of n-butanol for use in an intermediate layer. A coating solution was prepared. This intermediate layer coating solution was dip-coated on the conductive layer, and this was heated and dried at 100 ° C. for 30 minutes to form an intermediate layer having a thickness of 0.4 μm.

  Next, 11 parts of a crystalline hydroxygallium phthalocyanine crystal (charge generation material) having strong peaks at 7.4 ° and 28.2 ° of the Bragg angle (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction are prepared. did. It was mixed with 5 parts of polyvinyl butyral (trade name: ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.) and 130 parts of cyclohexanone, and cooled with cooling water at 18 ° C. in a sand mill using glass beads having a diameter of 1 mm. The mixture was dispersed for 2 hours. After the dispersion treatment, 300 parts of ethyl acetate and 160 parts of cyclohexanone were added to prepare a coating solution for charge generation layer. This charge generation layer coating solution was dip-coated on the intermediate layer and dried at 110 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.18 μm.

  Next, 5 parts of a compound (charge transport material) represented by the following structural formula (2), 5 parts of a compound (charge transport material) represented by the following structural formula (3), and a polycarbonate resin (trade name: Iupilon Z400, 10 parts of Mitsubishi Gas Chemical Co., Ltd.) was dissolved in a mixed solvent of 70 parts of monochlorobenzene and 30 parts of dimethoxymethane to prepare a coating solution for charge transport layer. The charge transport layer coating solution was dip coated on the charge generation layer and dried at 100 ° C. for 30 minutes to form a charge transport layer having a thickness of 17 μm.

  48.5 parts of the compound represented by the following structural formula (4) and 1.5 parts of exemplified compound (U-1) (manufactured by Tokyo Chemical Industry Co., Ltd., GC purity> 97%) are dissolved in 25 parts of n-propanol. Further, 25 parts of 1,1,2,2,3,3,4-heptafluorocyclopentane (trade name: Zeolora H, manufactured by Nippon Zeon Co., Ltd.) was added to prepare a coating solution for a protective layer. This protective layer coating solution was dip coated on the charge transport layer, and this was heat-treated at 50 ° C. for 5 minutes. Thereafter, an electron beam was irradiated for 1.5 seconds under conditions of an acceleration voltage of 150 kV and an absorbed dose of 15000 Gy in a nitrogen atmosphere. Further, heat treatment was performed at 130 ° C. for 90 seconds in a nitrogen atmosphere. The oxygen concentration from the electron beam irradiation to the heat treatment for 30 seconds was 19 ppm. Next, heat treatment was performed at 100 ° C. for 20 minutes in the air to form a protective layer having a thickness of 5 μm.

  Thus, an electrophotographic photosensitive member having a conductive layer, an intermediate layer, a charge generation layer, a charge transport layer, and a protective layer was produced.

(Comparative Example 1)
In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the exemplified compound (U-1) was not used.

(Example 2)
In Example 1, the charge transport layer coating solution was prepared by using 4.85 parts of the compound represented by the structural formula (2), 4.85 parts of the compound represented by the structural formula (3), and 9.7% of the polycarbonate resin. Parts of the compound (U-1) 0.6 parts in a mixed solvent of 70 parts of monochlorobenzene and 30 parts of dimethoxymethane, and then used in Comparative Example 1. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the protective layer coating solution was changed.

(Example 3)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the charge transport layer coating solution in Example 1 was changed to the charge transport layer coating solution used in Example 2.

Example 4
In Example 1, except that the charge generation layer coating solution obtained in Example 1 was added to the charge generation layer coating solution obtained by adding 0.5 parts of the exemplified compound (U-1) to the charge generation layer coating solution used in Example 1. An electrophotographic photoreceptor was produced in the same manner as in Example 1.

(Example 5)
In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the protective layer was not provided and the charge transport layer was changed to the following charge transport layer. 4.85 parts of the compound represented by the structural formula (2), 4.85 parts of the compound represented by the structural formula (3), and polyarylate disclosed in Example 2 of Patent Document 2003-195537. 9.7 parts of resin and 0.6 part of exemplary compound (U-1) were dissolved in a mixed solvent of 57 parts of monochlorobenzene and 30 parts of dimethoxymethane to obtain a coating solution for charge transport layer. The charge transport layer coating solution was dip-coated on the charge generation layer and dried at 120 ° C. for 60 minutes to form a charge transport layer having a thickness of 23 μm.

(Comparative Example 2)
In Example 5, an electrophotographic photosensitive member was produced in the same manner as in Example 5 except that the exemplified compound (U-1) was not used.

(Example 6)
In Example 1, the protective layer coating solution was changed to 49.5 parts of the compound represented by the above structural formula (4) and 0.5 parts of the exemplified compound (U-1). An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that it was prepared.

(Example 7)
In Example 1, except that the protective layer coating liquid was prepared by changing the compound represented by the structural formula (4) to 47 parts and the exemplified compound (U-1) to 3 parts, and preparing a protective layer coating liquid. In the same manner as in Example 1, an electrophotographic photoreceptor was produced.

(Example 8)
In Example 1, except that the protective layer coating liquid was prepared by changing the compound represented by the structural formula (4) to 40 parts and the exemplified compound (U-1) to 5 parts. In the same manner as in Example 1, an electrophotographic photoreceptor was produced.

Example 9
In Example 1, 48.5 parts of the compound represented by the structural formula (4), 1.5 parts of the exemplary compound (U-1), and polytetrafluoroethylene particles (trade name) : Lubron L2, Daikin Co., Ltd. 13 parts, n-propanol 25 parts and 1,1,2,2,3,3,4-heptafluorocyclopentane (trade names: Zeolora H, Nippon Zeon Co., Ltd.) Manufactured) An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that in addition to 25 parts of the mixed solvent, this was changed to a protective layer coating solution obtained by dispersing with an ultra-high pressure disperser. .

(Comparative Example 3)
In Example 9, an electrophotographic photosensitive member was produced in the same manner as in Example 9 except that the exemplified compound (U-1) was not used.

(Example 10)
In Example 1, the protective layer coating solution was dipentaerythritol hexaacrylate (trade name: DPHA, manufactured by Daicel-Cytec Co., Ltd.) (having six acrylic groups as polymerizable functional groups, and having a charge transport structure. No compound) 24.5 parts, 24 parts of the compound represented by the following structural formula (5), 1-hydroxy-cyclohexyl-phenyl-ketone (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals) (photopolymerization started) Agent) 2.5 parts and exemplary compound (U-1) 1.5 parts are dissolved in 25 parts of n-propanol, and 25 parts of 1,1,2,2,3,3,4-heptafluorocyclopentane is further added. Changed to what was added. Then, this protective layer coating solution is applied onto the charge transport layer by dip coating, followed by heat treatment at 50 ° C. for 5 minutes, and then using a metal halide lamp for 20 seconds under the condition of irradiation intensity: 500 mW / cm ^2. The film was irradiated with light and subjected to heat treatment at 130 ° C. for 30 minutes to form a protective layer having a thickness of 4.8 μm. Except for this, an electrophotographic photoreceptor was produced in the same manner as in Example 1.

(Comparative Example 4)
In Example 10, an electrophotographic photosensitive member was produced in the same manner as in Example 10 except that the exemplified compound (U-1) was not used.

(Example 11)
In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the exemplified compound (U-1) was changed to the exemplified compound (U-25) to prepare a protective layer coating solution.

(Example 12)
In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1, except that the exemplified compound (U-1) was changed to the exemplified compound (U-2) to prepare a protective layer coating solution.

(Example 13)
In Example 1, an electrophotographic photoreceptor was produced in the same manner as in Example 1 except that the exemplified compound (U-1) was changed to the exemplified compound (U-26) to prepare a protective layer coating solution.

(Example 14)
In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1, except that the exemplified compound (U-1) was changed to the exemplified compound (U-3) to prepare a protective layer coating solution.

(Example 15)
In Example 1, an electrophotographic photoreceptor was produced in the same manner as in Example 1 except that the exemplified compound (U-1) was changed to the exemplified compound (U-4) to prepare a protective layer coating solution.

(Example 16)
In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the exemplified compound (U-1) was changed to the exemplified compound (U-10) to prepare a coating solution for a protective layer.

(Example 17)
In Example 1, an electrophotographic photoreceptor was produced in the same manner as in Example 1 except that the exemplified compound (U-1) was changed to the exemplified compound (U-19) to prepare a protective layer coating solution.

(Example 18)
In Example 1, an electrophotographic photoreceptor was produced in the same manner as in Example 1 except that the exemplified compound (U-1) was changed to the exemplified compound (U-24) to prepare a protective layer coating solution.

(Comparative Example 5)
In Example 1, 48.5 parts of the compound represented by the structural formula (4), 0.75 parts of a hindered amine antioxidant (trade name: TINUVIN622LD, manufactured by Ciba Japan), Protection obtained by dissolving 0.75 part of the compound of structural formula (6) in 25 parts of n-propanol and adding 25 parts of 1,1,2,2,3,4,4-heptafluorocyclopentane. An electrophotographic photoreceptor was produced in the same manner as in Example 1 except that the layer coating solution was changed.

(Comparative Example 6)
In Example 1, 48.5 parts of the compound represented by the above structural formula (4), a hindered amine antioxidant of the following structural formula (7) (trade name: Sanol LS440, Sankyo Lifetech Co., Ltd.) 1.5 parts of (manufactured by company) was dissolved in 25 parts of n-propanol, and further 25 parts of 1,1,2,2,3,3,4-heptafluorocyclopentane was added to obtain a coating solution for protective layer An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the above was changed.

(Comparative Example 7)
In Example 1, 48.5 parts of the compound represented by the structural formula (4) and 1.5 parts of quinoxaline of the following structural formula (8) were dissolved in 25 parts of n-propanol. Further, an electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the protective layer coating solution was obtained by adding 25 parts of 1,1,2,2,3,3,4-heptafluorocyclopentane. Manufactured.

(Comparative Example 8)
In Example 1, 48.5 parts of the compound represented by the structural formula (4), 1 part of a hindered phenol compound of the following structural formula (9) (R in the formula (9) is the following: (Showing the structure represented by formula (10)), 0.7 parts by weight of dioctadecyl 3,3′-thiodipropionate, 0.7 parts by weight of tris (2,4-di-tert-butylphenyl) phosphite, 0.1 part by weight of 1,3-di (4-pyridyl) propane is dissolved in 25 parts of n-propanol, and 1,1,2,2,3,3,4-heptafluorocyclopentane (trade name: An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that 25 parts of Zeorolla H (manufactured by Nippon Zeon Co., Ltd.) were added and the coating solution was changed to a protective layer coating solution.

(Comparative Example 9)
In Example 1, 48.5 parts of the compound represented by the structural formula (4) and 1.5 parts of the compound represented by the following structural formula (10) were dissolved in 25 parts of n-propanol. In addition, the electrophotographic photosensitive film was obtained in the same manner as in Example 1 except that the coating liquid for protective layer was changed to 25 by adding 25 parts of 1,1,2,2,3,3,4-heptafluorocyclopentane. The body was manufactured.

(Comparative Examples 10-17)
In Example 1, Exemplified Compound (U-1) was changed to the compounds represented by Structural Formula (11) to Structural Formula (18) as shown in Table 1 to prepare a coating solution for protective layer. In the same manner as in Example 1, an electrophotographic photoreceptor was produced.

(Example 19)
In Example 1, the coating solution for the protective layer was prepared by using 48.5 parts of the compound represented by the structural formula (4), 1.5 parts of the exemplary compound (U-1), 13 parts of the polytetrafluoroethylene particles, and 1.5 parts of resin having a repeating structural unit represented by the formula (A1) and a repeating structural unit represented by the following formula (A2) (weight average molecular weight 130,000, (A1) / (A2) = 1/1) , 25 parts of n-propanol and 25 parts of 1,1,2,2,3,3,4-heptafluorocyclopentane, and a protective layer obtained by dispersing this with an ultrahigh pressure disperser An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the coating solution was changed to a coating solution for coating.

(Comparative Example 18)
In Example 19, an electrophotographic photosensitive member was produced in the same manner as in Example 19 except that the exemplified compound (U-1) was not used.

(Evaluation)
About the evaluation method of the electrophotographic photoreceptor of Examples 1-19 and Comparative Examples 1-18, it is as follows.

(Evaluation of black belt)
The black belt was evaluated as follows. As an evaluation apparatus, a copy machine imagePRESS C1 + (corona charging method) manufactured by Canon Inc. was used. In an image with a printing ratio of 5%, 100,000 sheets of A4 size plain paper were used. The charger was taken out from the copying machine.

  Another copy machine (imagePRESS C1 +) was prepared, the charger was replaced with the above-mentioned 100,000 used charger, and the manufactured electrophotographic photosensitive member was mounted. After using 5000 sheets of A4 size plain paper for images with a printing ratio of 5% in an environment of temperature 23 ° C and humidity 5% RH, power supply to the copier was stopped and the printer was suspended for 15 hours. It was. After 15 hours, power supply to the copier was started again, and a halftone image of a 1-dot Keima pattern was output on plain A3 size paper and cyan single color. The light intensity was set so that the halftone density was 0.85 with a spectral densitometer X-rite 504 (manufactured by X-rite). For this halftone image, the density of the portion facing the charger and the portion not facing the charger were measured by X-Rite. The difference in concentration is shown in Table 2. In the present invention, if the difference in concentration was less than 0.1, it was judged that the effect of the present invention was obtained. On the other hand, when 0.1 or more, it was judged that the effect of this invention was not acquired.

(Evaluation of density difference between exposed and unexposed areas)
The density difference between the exposed area and the non-exposed area was evaluated as follows. As an evaluation apparatus, a copy machine imagePRESS C1 + manufactured by Canon Inc. was used. The produced electrophotographic photosensitive member was mounted on a copying machine. Under the environment of temperature 23 ° C and humidity 5% RH, the density difference between the exposed and unexposed areas of the A3 size plain paper and cyan single color, without the pre-cleaning exposure of the two static elimination lights. An image for evaluation (as shown in FIG. 3), a square solid image is produced in a white background (white image) at the head of the image, and then an image in which a halftone of a 1-dot Keima pattern is combined is produced. When there is a density difference in the non-exposed area, a low density portion corresponding to the solid image pattern is generated in a portion corresponding to one round of the drum from the solid image of the halftone portion. The amount of light was set so that the halftone density was 0.85 in X-Rite. Of the halftone portion of the obtained image, the density of the portion where the circumference of the drum was a white solid portion and a black solid portion was measured by X-rite. Table 2 shows the density difference between the exposed area and the non-exposed area. In the present invention, if the density difference between the exposed area and the non-exposed area is greater than −0.1 and 0.0 or less, it is determined that the effect of the present invention is obtained. On the other hand, it was judged that the effect of the present invention was not obtained when the value was -0.1 or less.

DESCRIPTION OF SYMBOLS 101 Support body 102 Intermediate | middle layer 103 Charge generation layer 104 Charge transport layer 105 Protective layer 1 Electrophotographic photoreceptor 2 Axis 3 Charging means 4 Exposure light 5 Developing means 6 Primary transfer means 7 Intermediate transfer body 8 Secondary transfer means 9 Transfer material 10 Cleaning means 11 Pre-exposure means 12 Pre-exposure light

Claims (4)

In an electrophotographic apparatus having a charging means for charging an electrophotographic photosensitive member by a charging method involving discharge,
The electrophotographic photosensitive member used in the electrophotographic apparatus has a support, a charge generation layer formed on the support, a charge transport layer formed on the charge generation layer,
Among the charge generation layer and the layer located on the surface side of the electrophotographic photoreceptor from the charge generation layer, at least one layer contains a compound having a structure represented by the following formula (1) An electrophotographic apparatus.
(However,
The electrophotographic apparatus has a cleaning blade, and the electrophotographic apparatus supplies basic particles having a number average particle size of 30 to 500 nm to a portion where the surface of the electrophotographic photosensitive member is in contact with the cleaning blade. And
When the electrophotographic apparatus has a developing means, and the developing means has a developer containing basic particles having a number average particle size of 30 to 500 nm,
except for. )

(In formula (1), X represents an oxygen atom or a sulfur atom. R ¹ and R ² each independently represents an alkyl group having 1 to 3 carbon atoms. Ar ¹ and Ar ² are each represented by Independently, it represents a substituted or unsubstituted aryl group, provided that the aryl group may have a carboxyl group, a cyano group, a substituted or unsubstituted amino group, a hydroxyl group, a substituted or unsubstituted alkoxy group. Group, substituted or unsubstituted alkyl group, nitro group, or halogen atom.) The electrophotographic photoreceptor has a protective layer formed on the charge transport layer,
The electrophotographic apparatus according to claim 1, wherein at least one of the charge transport layer and the protective layer contains a compound having a structure represented by the formula (1). The electrophotographic apparatus according to claim 1, wherein R ¹ and R ² in the formula (1) are the same group, and Ar ¹ and Ar ² are the same group. The electrophotographic apparatus according to claim 1, wherein the protective layer contains a compound having a structure represented by the formula (1).

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