JP2012137599A - Electrophotographic photoreceptor, image forming method using the electrophotographic photoreceptor, image forming apparatus, and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor that has high durability against repeated use for a long period, suppresses image deterioration due to a decrease in image density or the occurrence of image blur, and suppresses variation in potential of an exposure part not only in a day but also in a job to ensure high-quality images in a stable manner.SOLUTION: An electrophotographic photoreceptor has a photosensitive layer and a crosslinked surface layer formed on a conductive support. The crosslinked surface layer contains a compound represented by the general formula (1), [wherein R1 to R3 each independently represents a phenyl group, biphenyl group, or a condensed polycyclic hydrocarbon group optionally including a substituent of any one of an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a halogen atom; and at least one of R1 to R3 is a condensed polycyclic hydrocarbon group optionally including a substituent of any one of an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a halogen atom], and a crosslinked polymer.

Description

  The present invention relates to an electrophotographic photosensitive member having a cross-linked surface layer containing a specific charge transport material, an electrophotographic method using the electrophotographic photosensitive member, an electrophotographic apparatus, and a process cartridge.

  An electrophotographic photoreceptor (hereinafter sometimes referred to as “photoreceptor”) has a function of holding surface charges in the dark, a function of receiving light to generate charges, and a function of receiving light to transport charges. A so-called single-layer type photoreceptor that combines these functions in a single layer, a layer that mainly contributes to charge generation, surface charge retention in the dark, and charge transport during photoreception There is a so-called function-separated stacked type photoreceptor in which a layer that has been function-separated is laminated on a layer that contributes to the above.

  For example, a Carlson method is applied to image formation by electrophotography using these photoreceptors. Image formation by this method is performed by charging a photoconductor in a dark place by corona discharge, forming an electrostatic latent image such as text or a picture of an original on the surface of the charged photoconductor, The image is developed by toner, and the developed toner image is fixed on a support such as paper. After the toner image is transferred, the photoreceptor is subjected to charge removal, residual toner removal, light charge removal, etc., and then reused. Provided.

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

  Recently, image forming apparatuses equipped with electrophotographic photoreceptors are rapidly becoming full-color and speeding up, and accordingly, demand is diversified from general office areas to SOHO areas or light printing areas. ing. In particular, in the light printing field, the printing volume is remarkably increased and the demand for image quality stability is increased. Therefore, it is indispensable to further increase the durability and stability of the organic photoreceptor.

  On the other hand, as a method for improving the durability of the organic photoreceptor, for example, as described in Patent Document 1, a method of providing a crosslinked surface layer has been proposed. The crosslinked surface layer is a film having excellent wear resistance by three-dimensionally crosslinking a material that is cured by light energy and an electron beam. Furthermore, there are some in which inorganic fine particles and organic fine particles are dispersed in the cross-linked surface layer in order to improve abrasion wear resistance. However, a photoreceptor having such a crosslinked surface layer is effective for wear resistance but insufficient for electrostatic stability.

Although not all of the causes of the lack of electrostatic stability for photoreceptors having a cross-linked surface layer have been elucidated, one of the factors is the charge transport material contained in the cross-linked surface layer. There is a possibility that the part is affected by light energy or an electron beam and changes such as decomposition occur. In other words, at least a part of the charge transporting material changes variously according to light energy or electron beam, and compounds having various energy levels exist in the crosslinked surface layer. The presence of these substances in the cross-linked surface layer causes various changes in characteristics over time of use of the photoreceptor. For example, the charging potential is lowered, the exposed part potential is changed, and the resolving power is lowered due to a reduction in surface resistance (image blur). Cause. As a result, it is considered that the image quality is remarkably lowered and the life of the photoreceptor is shortened. In particular, in an electrophotographic apparatus used in the field of light printing that requires a very long life and high stability, fluctuations in the exposed portion potential of the photosensitive member are a serious problem. The exposure portion potential fluctuation is more problematic when the printing is started and one job is completed and printing is resumed than when the exposure portion potential fluctuation is performed when printing is performed for a relatively long time. As big as.
Hereinafter, the former is referred to as daily fluctuation of the exposure part potential, and the latter is referred to as intra-job fluctuation of the exposure part potential.

  In the case of daily fluctuations in the exposure part potential, the effect is not noticeable and the potential can be corrected in the apparatus. Therefore, the problem is not so great, but if the fluctuation in the job is large, the influence is conspicuous. If the potential fluctuates by several tens or several sheets in the job, it becomes difficult to correct the potential, which is a serious problem. In particular, in the light printing field, there is a demand for printing a large amount of the same image pattern with one job. In this case, if the fluctuation in the exposure portion potential in the job is large, the image density changes and the image quality consistency is lowered. become. If it is a character-based image pattern, it will not stand out so much, but if it is an image-based and full-color image pattern, not only the image density but also the color will change, leading to a very serious problem. That is, it is required to reduce the fluctuation of the exposed portion potential of the photosensitive member and further suppress the fluctuation of the exposed portion potential in the long-term repetitive printing as well as the fluctuation in the job in addition to the daily fluctuation.

Various proposals have been made to improve the electrostatic stability of a photoreceptor having a crosslinked surface layer.
For example, in the invention described in Patent Document 1, it is formed by curing a radical polymerizable monomer having at least a trifunctional or higher functional charge transport structure and a radical polymerizable monomer having a charge transport layer structure. An electrophotographic photosensitive member having a surface layer and having high image quality with high durability and stability is described.

  In the invention described in Patent Document 2, a total of two or more types selected from the group consisting of a chain polymerizable benzidine compound and a chain polymerizable triphenylamine compound for the crosslinked surface layer (second charge transport layer). A method for improving the electrical properties of the crosslinked surface layer by incorporating the above compound in a polymer obtained by performing either or both of polymerization and crosslinking has been proposed. And when cross-linked, these molecules lose freedom and the charge transport function is reduced. In addition, since a reactive charge transport material is used, it is fully considered that an unreacted charge transport material may remain or that there is some influence on the charge transport structure during a crosslinking reaction or a polymerization reaction. In such a case, these charge transport materials are easily affected by an oxidizing gas or the like, and become a factor for accumulating electric charge, which causes a deterioration in electrostatic stability.

  In the invention described in Patent Document 3, by using a charge transporting polymer compound in the charge transport layer under the cross-linked surface layer (surface protective layer), elution of the charge transport material to the cross-linked surface layer is prevented. It has been proposed to prevent degradation of electrical properties. However, when crosslinking is performed by electron beam or light irradiation, deterioration of the charge transport material used for the crosslinked surface layer cannot be prevented.

  In the invention described in Patent Document 4, ultraviolet rays having a wavelength of 310 nm or less are mainly used as cured ultraviolet rays having a high absorption coefficient with respect to organic materials, thereby absorbing the ultraviolet rays in the vicinity of the surface. As a result, a method for preventing the deterioration of the performance of the organic photoreceptor that occurs when the UV curable paint is cured has been proposed, but the UV curable charge transporting material absorbs light during UV irradiation, and the molecule deteriorates. In other words, sufficient electrostatic stability cannot be obtained.

  In the invention described in Patent Document 5, not only the charge transporting radical polymerizable monomer but also the low molecular charge transporting material same as the charge transporting layer is contained in the crosslinkable charge transporting layer, thereby having a crosslinkable charge transporting layer. A method has been proposed to improve the electrostatic stability of the resin, but in this case as well, the charge transporting radical polymerizable monomer and the low molecular charge transporting material are deteriorated during UV irradiation, and the electrostatic stability is lowered. End up.

  Further, in the invention described in Patent Document 6, it is formed with a cured product of a mixture containing at least a first charge transporting compound having an acryloyloxy group or a methacryloyloxy group and a second charge transporting compound having a hydroxyl group. By adding a charge transporting compound having at least one hydroxyl group having high affinity with the acryloyloxy group and methacryloyloxy group in the same molecule and curing it, the hydroxyl group is incorporated into the three-dimensional network crosslinked structure. It is described that a charge transporting compound having a charge transporting group can be formed and an ideal charge transporting layer can be formed, but the charge transporting compound having a hydroxyl group has an affinity for water vapor. Because it is high, the stability against environmental fluctuation is poor. In addition, if a charge transport material having various energy levels is present in the charge transport layer, the electric characteristics are deteriorated because the charge transfer is inhibited between the materials, so that the electrostatic stability is insufficient. is there.

  The object of the present invention has high durability even for repeated use over a long period of time, and suppresses image deterioration due to image density reduction or image blurring. An object of the present invention is to provide an electrophotographic photosensitive member that suppresses fluctuations in the job and can stably obtain high-quality images.

  As a result of intensive studies to solve the above problems, the present inventors have solved the above problems by the electrophotographic photosensitive member, the image forming apparatus and the like according to the present invention described in the following (1) to (7). As a result, the present invention was reached.

(1) It has at least a photosensitive layer and a crosslinked surface layer on a conductive support, and the crosslinked surface layer contains at least a compound represented by the general formula (1) and a crosslinked polymer. Electrophotographic photoreceptor.

[In the formula (1), R1 to R3 may each independently have a substituent of any of an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a halogen atom. Represents a phenyl group, a biphenyl group or a condensed polycyclic hydrocarbon group, and at least one of R1 to R3 is a substitution of any one of an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a halogen atom A condensed polycyclic hydrocarbon group which may have a group; ]
(2) The electrophotographic photosensitive member according to (1), wherein the crosslinked surface layer is a crosslinked film cured by light energy irradiation.
(3) The electrophotographic photosensitive member according to (1) or (2), wherein the crosslinked surface layer contains inorganic fine particles.
(4) An image forming method, wherein at least charging, image exposure, development, and transfer are repeated using the electrophotographic photosensitive member according to any one of (1) to (3) above.
(5) At least an electrophotographic photosensitive member, a charging unit, an exposing unit, a developing unit, and a transferring unit are provided, and the electrophotographic photosensitive member is any one of the above (1) to (3). An image forming apparatus.
(6) The electrophotographic photosensitive member according to any one of (1) to (3) above, and at least one means selected from the group consisting of a charging means, a developing means, a transfer means, a cleaning means, and a static elimination means. And a process cartridge which is detachable from the main body of the image forming apparatus.

According to the electrophotographic photosensitive member of the present invention, in the electrophotographic photosensitive member having a crosslinked surface layer excellent in mechanical durability, the compound represented by the general formula (1) is contained in the crosslinked surface layer, whereby light energy is obtained. In addition, the charge transporting material is prevented from being deteriorated during electron beam irradiation and the charge transporting function is not deteriorated, so that the electrostatic characteristics are stable even when used repeatedly for a long time, and the exposed portion potential and residual potential increase. Reduced.
Furthermore, fluctuations in the job are also suppressed, and high-quality images can be obtained stably over a long period of time.
In addition, according to the present invention, an image forming method, an image forming apparatus, and an image forming apparatus capable of outputting an image with little change in image density and color tone, that is, excellent image quality consistency, by using the electrophotographic photosensitive member. A process cartridge is provided.

It is sectional drawing which shows the structural example of the electrophotographic photoreceptor in this invention. It is sectional drawing which shows the other structural example of the electrophotographic photoreceptor in this invention. 2 is a powder X-ray diffraction spectrum of titanyl phthalocyanine used in Example 1 of the present invention. 1 is a schematic diagram illustrating an example of an image forming apparatus of the present invention. FIG. 2 is a schematic diagram illustrating an example of a process cartridge for an image forming apparatus according to the present invention.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

<Electrophotographic photoreceptor>
FIG. 1 is a cross-sectional view showing the structure of the photoreceptor of the present invention. A photosensitive layer (33) mainly composed of a charge generating substance and a charge transporting substance is provided on a conductive support (31). A crosslinked surface layer (39) is provided on the surface of the photosensitive layer.
FIG. 2 is a sectional view showing still another structure of the photoconductor of the present invention. On the conductive support (31), a charge generation layer (35) mainly composed of a charge generation material and a charge transport material are provided. The charge transport layer (37) as a main component is laminated, and a cross-linked surface layer (39) is further provided on the charge transport layer (37).

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

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

(Photosensitive layer)
Next, the photosensitive layer will be described.
The photosensitive layer may be a single-layer photosensitive layer (FIG. 1) containing a charge generation material and a charge transport material, or a laminated type (FIG. 2) composed of a charge generation layer and a charge transport layer. The photosensitive layer (FIG. 2) having a laminated structure will be described first.

[Charge generation layer]
The charge generation layer (35) is a layer mainly composed of a charge generation material. A known charge generation material can be used for the charge generation layer (35), and representative examples thereof include a monoazo pigment, a disazo pigment, a trisazo pigment, a perylene pigment, a perinone pigment, a quinacridone pigment, and a quinone condensation. Examples thereof include polycyclic compounds, squaric acid dyes, other phthalocyanine pigments, naphthalocyanine pigments, and azulenium salt dyes. These charge generation materials may be used alone or in combination of two or more.

  In the charge generation layer (35), the charge generation material is dispersed in a suitable solvent together with a binder resin, if necessary, using a ball mill, attritor, sand mill, ultrasonic wave, etc., and this is applied onto a conductive support. And formed by drying.

  The binder resin used as necessary includes polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, polysulfone, poly-N-vinylcarbazole, poly Examples include acrylamide, polyvinyl benzal, polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyamide, polyvinyl pyridine, cellulosic resin, casein, polyvinyl alcohol, and polyvinyl pyrrolidone. The amount of the binder resin is suitably 0 to 500 parts by weight, preferably 10 to 300 parts by weight with respect to 100 parts by weight of the charge generating material. The binder resin may be added before or after dispersion.

  As the solvent of the coating solution used for forming the charge generation layer (35), isopropanol, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloromethane, monochlorobenzene, cyclohexane, toluene, Xylene, ligroin and the like can be mentioned, and ketone solvents, ester solvents and ether solvents are particularly preferably used. These may be used alone or in combination of two or more.

The charge generation layer (35) is formed by dispersing a charge generation material in a solvent using a known dispersion method such as a ball mill, an attritor, a sand mill, a bead mill, or an ultrasonic wave together with a binder resin as necessary. A liquid can be obtained. The charge generation layer (35) is mainly composed of a charge generation material, a solvent, and a binder resin, but may contain various additives such as a sensitizer, a dispersant, a surfactant, and silicone oil. . As a coating method for the coating solution, a dip coating method, spray coating, beat coating, nozzle coating, spinner coating, ring coating, or the like can be used.
The film thickness of the charge generation layer (35) is suitably about 0.01 to 5 μm, preferably 0.1 to 2 μm.

[Charge transport layer]
The charge transport layer (37) is a layer mainly composed of a charge transport material and a charge transport material, and the content of the charge transport material in the charge transport layer (37) is 30 with respect to 100 parts by weight of the binder resin. It is preferable to set it to -200 weight part. If the content of the charge transport material is less than 30 parts by weight, the electrical characteristics deteriorate, for example, the residual potential increases. On the other hand, when the amount is more than 200 parts by weight, mechanical properties such as wear resistance are lowered.

Examples of the charge transport material used for the charge transport layer (37) include the following.
Charge transport materials include electron transport materials and hole transport materials.
Examples of the electron transporting material include chloroanil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4 , 5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-tri Examples thereof include electron-accepting substances such as nitrodibenzothiophene-5,5-dioxide and benzoquinone derivatives.
Examples of hole transport materials include poly-N-vinylcarbazole and derivatives thereof, poly-γ-carbazolylethyl glutamate and derivatives thereof, pyrene-formaldehyde condensates and derivatives thereof, polyvinylpyrene, polyvinylphenanthrene, polysilane, oxazole derivatives, Oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triarylmethane derivatives, 9-styrylanthracene derivatives, pyrazolines Derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, etc., bisstilbene derivatives, enamine derivatives, etc. Known materials may be mentioned.
These charge transport materials may be used alone or in combination of two or more.

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

The charge transport layer (37) can be obtained by dissolving a charge transport material together with a binder resin in a solvent.
Tetrahydrofuran, dioxane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, methyl ethyl ketone, acetone and the like are used as the solvent for the coating solution used for forming the charge transport layer (37). These may be used alone or in combination of two or more.
As a coating method of the coating solution, a conventional coating method such as dip coating, spray coating, beat coating, nozzle coating, spinner coating, ring coating, or the like can be used.

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

[Single layer photosensitive layer]
Next, the case where the photosensitive layer has a single layer structure (in the case of FIG. 1) will be described.
The photosensitive layer (33) can be formed by dissolving or dispersing a charge generating substance, a charge transporting substance and a binder resin in an appropriate solvent, and applying and drying it. If necessary, a plasticizer, leveling agent, and antioxidant can be formed. An agent or the like can also be added.
In the case of the photosensitive layer (33) having a single layer structure, it is preferable to use the above-described electron transporting material in combination as a charge transporting material for high sensitivity.
In the photosensitive layer (33) having a single layer structure, the charge generating material is 0.1 to 30% by weight, preferably 0.5 to 5% by weight, based on the entire photosensitive layer. When the concentration of the charge generating substance is low, the photoreceptor sensitivity tends to decrease, and when the concentration is high, the chargeability and the film strength tend to decrease.
The content of the charge transport material is preferably 30 to 200 parts by weight with respect to 100 parts by weight of the binder resin. The content of the electron transport material is preferably 30 to 200 parts by weight with respect to 100 parts by weight of the binder resin.
The film thickness of the photosensitive layer is preferably 50 μm or less, and preferably 25 μm or less from the viewpoint of resolution and responsiveness. The lower limit varies depending on the system to be used (particularly charging potential), but is preferably 5 μm or more.

(Crosslinked surface layer)
Next, the crosslinked surface layer will be described.
The surface layer (39) of the photoreceptor of the present invention has a crosslinked surface layer, and the crosslinked surface layer contains at least a compound represented by the following formula (1) (charge transport material) and a crosslinked polymer. Yes.
[Compound shown in Formula (1)]

[In the formula (1), R1 to R3 may each independently have a substituent of any of an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a halogen atom. A phenyl group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a biphenyl group optionally having a substituent of a halogen atom, or an alkyl group having 1 to 4 carbon atoms, carbon Represents a condensed polycyclic hydrocarbon group which may have any substituent of an alkoxy group having 1 to 4 halogen atoms, and at least one of R1 to R3 is an alkyl group having 1 to 4 carbon atoms , An alkoxy group having 1 to 4 carbon atoms, or a condensed polycyclic hydrocarbon group which may have any substituent of a halogen atom. ]
Examples of the halogen atom include a chlorine atom, a bromine atom, and a fluorine atom. Moreover, a preferable thing is a methyl group with a C1-C4 alkyl group, and a preferable thing is a methoxy group with a C1-C4 alkoxy group.
Examples of the compound (charge transport material) represented by the general formula (1) include the following, but are not limited thereto.

  The compound represented by the general formula (1) is 10 to 70% by weight, preferably 30 to 60% by weight, based on the entire crosslinked surface layer (39).

  The crosslinked surface layer (39) undergoes a crosslinking reaction by irradiation with thermal energy, light energy or electron beam. Preferably, a resin (crosslinked polymer) crosslinked by light energy or electron beam irradiation becomes a film having high hardness and high elasticity.

A compound having a triphenylamine skeleton in which R1 to R3 are all phenyl groups in the general formula (1) has a charge transport function and is effectively used as a charge transport material for an electrophotographic photoreceptor. However, a compound having a triphenylamine skeleton is liable to cause a chemical reaction upon irradiation with heat energy, light energy, electron beam or the like, resulting in decomposition or structural change. When a photocrosslinked surface layer containing a charge transport material is formed, the charge transport material undergoes changes such as decomposition in the crosslinked surface layer as described above, so that compounds having various energy levels are formed. Will exist. These substances cause various characteristic changes with the lapse of time of use of the photoreceptor, and cause, for example, a decrease in charging potential, a change in potential of an exposed portion, a decrease in resolution due to a decrease in surface resistance (image blur), and the like.
In contrast, even if at least one of R1 to R3 of the present invention has a substituent of any one of an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a halogen atom, a condensed polycyclic group In the case of a compound having a charge transport function (charge transport material) which is a hydrocarbon group, it is difficult to cause a chemical reaction due to irradiation with light energy or an electron beam, and does not cause the above-described fluctuation in characteristics of the photoreceptor. A good surface layer can be obtained.

  In addition, when all of the charge transport material contained in the cross-linked surface layer (39) has a cross-linking reactive group, the charge transport material itself is cross-linked by the cross-linking reaction, so the degree of freedom of the charge transport material is lost, and the charge transport function Is expected to decrease. On the other hand, in order to ensure the degree of freedom of the charge transport material, if the amount of energy of the irradiated light or electron beam is reduced to leave an uncrosslinked charge transport material, the crosslink density of the crosslinked film decreases, Abrasion resistance is also expected to decrease. In addition, when an uncrosslinked charge transport material remains in the crosslinked surface layer, since the crosslinking reactive group is highly polar and easily adsorbs or reacts with the oxidizing gas, the photoconductor is discharged from the charging charger over time. It is considered that the product is likely to be deteriorated by a product (oxidizing gas or the like), and it is considered that the electrostatic stability over a long period cannot be maintained, for example, the exposure part potential fluctuation due to the charge trap and the image blur due to the resistance decrease.

[Crosslinked polymer]
Examples of the crosslinked polymer (polymerizable compound that is crosslinked by light energy or electron beam irradiation) used in the crosslinked surface layer (39) of the present invention include trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate, and HPA. Modified trimethylolpropane triacrylate, EO modified trimethylolpropane triacrylate, PO modified trimethylolpropane triacrylate, caprolactone modified trimethylolpropane triacrylate, HPA modified trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate (PETTA) ), Glycerol triacrylate, ECH-modified glycerol triacrylate, EO-modified glycerol triacrylate Rate, PO modified glycerol triacrylate, tris (acryloxyethyl) isocyanurate, dipentaerythritol hexaacrylate (DPHA), caprolactone modified dipentaerythritol hexaacrylate, dipentaerythritol hydroxypentaacrylate, alkyl modified dipentaerythritol pentaacrylate, alkyl Modified dipentaerythritol tetraacrylate, alkyl modified dipentaerythritol triacrylate, dimethylolpropane tetraacrylate (DTMPTA), pentaerythritol ethoxytetraacrylate, EO modified phosphoric acid triacrylate, 2,2,5,5-tetrahydroxymethylcyclopenta Non-tetraacrylate, etc. are mentioned, and these are single or two kinds It may be used in combination with the above.

[Photopolymerization initiator]
Moreover, in order to perform a crosslinking reaction efficiently by light energy or electron beam irradiation, a photopolymerization initiator is preferably contained.
Examples of the photopolymerization initiator include diethoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 4- (2-hydroxyethoxy) phenyl- (2 -Hydroxy-2-propyl) ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2- Acetophenone-based or ketal-based photopolymerization initiators such as methyl-2-morpholino (4-methylthiophenyl) propan-1-one and 1-phenyl-1,2-propanedione-2- (o-ethoxycarbonyl) oxime, benzoin , Benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl ether Benzoin ether photopolymerization initiators such as benzoin isopropyl ether, benzophenone, 4-hydroxybenzophenone, methyl o-benzoylbenzoate, 2-benzoylnaphthalene, 4-benzoylbiphenyl, 4-benzoylphenyl ether, acrylated benzophenone, 1, Benzophenone photopolymerization initiators such as 4-benzoylbenzene, thioxanthone photopolymerization initiation such as 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone And other photopolymerization initiators include ethyl anthraquinone, 2,4,6-trimethylbenzoyl diphenylphosphine oxide, 2,4,6-trimethylbenzoylpheny Ethoxyphosphine oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, bis (2,4-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, methylphenylglyoxyester, 9,10- Examples include phenanthrene, acridine compounds, triazine compounds, and imidazole compounds. Moreover, what has a photopolymerization acceleration effect can also be used individually or in combination with the said photoinitiator. Examples thereof include triethanolamine, methyldiethanolamine, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, (2-dimethylamino) ethyl benzoate, 4,4′-dimethylaminobenzophenone, and the like.

  These polymerization initiators may be used alone or in combination of two or more. Content of a polymerization initiator is 0.5 to 40 weight% with respect to a crosslinking | crosslinked polymerizable monomer, Preferably it is 1 to 20 weight%.

[Inorganic fine particles]
The photoreceptor of the present invention can contain inorganic fine particles for the purpose of improving the mechanical durability of the crosslinked surface layer (39). The inorganic fine particles may be those generally known, such as titanium oxide, tin oxide, zinc oxide, zirconium oxide, indium oxide, antimony oxide, boron nitride, silicon nitride, calcium oxide, barium sulfate, ITO, silicon oxide, colloidal silica. Examples thereof include aluminum oxide. In consideration of the electrical characteristics of the crosslinked surface layer (39), aluminum oxide, titanium oxide, silicon oxide, and tin oxide are preferably used.

  The average primary particle diameter of these inorganic fine particles (fillers) is preferably 0.01 to 0.5 μm from the viewpoint of light transmittance and wear resistance of the surface layer. When the average primary particle size of the filler is 0.01 μm or less, it causes a decrease in wear resistance, a decrease in dispersibility, etc., and when it exceeds 0.5 μm, the surface roughness of the surface layer increases, which will be described later. Wear of the blade cleaning member progresses quickly, causing toner cleaning failure early, and depending on the specific gravity of the filler particles, the coating liquid life such as promoting the sedimentation of the filler in the dispersion May cause problems.

  The higher the filler material concentration in the cross-linked surface layer (39), the better the wear resistance. However, if the filler material concentration is too high, the residual potential increases and the write light transmittance of the protective layer decreases, causing side effects. There is a case. Therefore, it is about 50% by weight or less, preferably about 30% by weight or less based on the total solid content.

[Formation of crosslinked surface layer]
The crosslinked surface layer is formed by applying and curing a coating solution containing at least the polymerizable compound (crosslinked polymerizable monomer) as described above and the compound represented by the general formula (1) (charge transporting substance). . When the component of the crosslinked surface layer is a liquid at room temperature, the coating solution used for coating can be applied by dissolving other components in this, but if necessary, it can be diluted with a solvent. Is done.

  Solvents used at this time include alcohols such as methanol, ethanol, propanol and butanol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, esters such as ethyl acetate and butyl acetate, tetrahydrofuran, dioxane and propyl ether. Ethers such as dichloromethane, halogens such as dichloromethane, dichloroethane, trichloroethane, and chlorobenzene, aromatics such as benzene, toluene, and xylene, and cellosolves such as methyl cellosolve, ethyl cellosolve, and cellosolve acetate. These solvents may be used alone or in combination of two or more.

The dilution ratio with the solvent varies depending on the solubility of the composition, the coating method, and the target film thickness, and is arbitrary. The coating can be performed using a dip coating method, spray coating, bead coating, ring coating method or the like.
In this invention, after apply | coating this coating liquid, a surface layer is hardened by giving energy from the outside. As the external energy used at this time, light energy or an electron beam can be used. However, when an electron beam is used, the deterioration of the photosensitive member constituent material is caused by the energy penetration depth and energy intensity. Because of concern, it is preferable to use light energy. Moreover, you may use heat energy together.

  As the energy of light, UV irradiation light sources such as high-pressure mercury lamps and metal halide lamps, which mainly have an emission wavelength in ultraviolet light, can be used, but a visible light source can also be selected according to the absorption wavelength of radically polymerizable substances and photopolymerization initiators. Is possible. Moreover, the reactivity of the crosslinking reaction by radical polymerization is greatly affected by temperature, and the surface temperature of the coating film during UV irradiation is preferably maintained at 20 ° C. or higher and 170 ° C. or lower. The surface temperature control means of the coating film may be any method as long as the above temperature range can be maintained, but a method of controlling the temperature using a heat medium is preferable.

  Furthermore, the crosslinked surface layer coating solution of the present invention can contain additives such as various plasticizers (for the purpose of stress relaxation and adhesion improvement) and leveling agents as necessary. As these additives, known additives can be used, and as plasticizers, those used in general resins such as dibutyl phthalate and dioctyl phthalate can be used, and the amount used is the total solid content of the coating liquid. To 20% by weight or less, preferably 10% or less. As leveling agents, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, polymers or oligomers having a perfluoroalkyl group in the side chain can be used, and the amount used is based on the total solid content of the coating liquid. 3% by weight or less is appropriate.

The thickness of the crosslinked surface layer of the present invention is preferably 1 to 30 μm, more preferably 2 to 20 μm, and further preferably 4 to 15 μm.
If the thickness is less than 1 μm, the durability of the crosslinked surface layer is often not ensured because the film thickness of the crosslinked surface layer is too small for the amount of indentation on the surface of the photoreceptor when carrier adhesion occurs. On the other hand, if it is thicker than 30 μm, it may cause problems such as an increase in residual potential. Therefore, it is necessary to form a cross-linked surface layer with a suitable thickness so as to ensure a margin for wear and scratches and to reduce the occurrence of residual potential.

[Middle layer]
In the photoreceptor of the present invention, an intermediate layer can be provided between the photosensitive layer (single-layer photosensitive layer 33 or charge generation layer 35) and the crosslinked surface layer. In the intermediate layer, a binder resin is generally used as a main component. Examples of these resins include polyamide, alcohol-soluble nylon, water-soluble polyvinyl butyral, polyvinyl butyral, and polyvinyl alcohol. As a method for forming the intermediate layer, a generally used coating method as described above is employed. In addition, about 0.05-2 micrometers is suitable for the thickness of an intermediate | middle layer.

[Undercoat layer]
In the photoreceptor of the present invention, an undercoat layer (not shown) can be provided between the conductive support (31) and the photosensitive layer (single-layer photosensitive layer 33 or charge generation layer 35). In general, the undercoat layer is mainly composed of a resin. However, considering that the photosensitive layer is coated with a solvent on these resins, it is desirable that the resin be a resin having a high solvent resistance with respect to a general organic solvent. . Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane, melamine resin, phenol resin, alkyd-melamine resin, and epoxy. Examples thereof include a curable resin that forms a three-dimensional network structure such as a resin.
Further, fine powder pigments of metal oxides such as titanium oxide, silica, alumina, zirconium oxide, tin oxide, and indium oxide may be added to the undercoat layer in order to prevent moire and reduce residual potential.

These undercoat layers can be formed using an appropriate solvent and a coating method like the above-mentioned photosensitive layer. Also, as the undercoat layer of the present invention, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can be used, or Al ₂ O ₃ provided by anodization, polyparaxylylene (parylene) ) And other organic substances such as SiO ₂ , SnO ₂ , TiO ₂ , ITO, and CeO ₂ provided by a vacuum thin film forming method can also be used favorably. Further, other known ones can also be used. The thickness of the undercoat layer is suitably from 0 to 5 μm.

[Additives added as necessary]
In the present invention, in order to improve environmental resistance, it is known for each layer such as a charge generation layer, a charge transport layer, an undercoat layer, a protective layer, and an intermediate layer, in particular for the purpose of preventing a decrease in sensitivity and an increase in residual potential. Antioxidants, plasticizers, lubricants, UV absorbers and leveling agents can be added. In addition to the plasticizer and leveling agent, an antioxidant, a lubricant, and an ultraviolet absorber can be added to the crosslinked surface layer.

Examples of the antioxidant include the following.
(A) Phenolic compounds 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, n-octadecyl -3- (4'-hydroxy-3 ', 5'-di-t-butylphenol), 2,2'-methylene-bis- (4-methyl-6-t-butylphenol), 2,2'- Methylene-bis- (4-ethyl-6-tert-butylphenol), 4,4′-thiobis- (3-methyl-6-tert-butylphenol), 4,4′-butylidenebis- (3-methyl) -6-tert-butylphenol), 1,1,3-tris- (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6- Tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tetrakis [Methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane, bis [3,3′-bis (4′-hydroxy-3′-t-butyl) Phenyl) butyric acid] cricol ester, tocopherols and the like.
(B) Paraphenylenediamines N-phenyl-N′-isopropyl-p-phenylenediamine, N, N′-di-sec-butyl-p-phenylenediamine, N-phenyl-N-sec-butyl-p-phenylene Diamine, N, N′-di-isopropyl-p-phenylenediamine, N, N′-dimethyl-N, N′-di-t-butyl-p-phenylenediamine and the like.
(C) Hydroquinones 2,5-di-t-octylhydroquinone, 2,6-didodecylhydroquinone, 2-dodecylhydroquinone, 2-dodecyl-5-chlorohydroquinone, 2-t-octyl-5-methylhydroquinone, 2 -(2-octadecenyl) -5-methylhydroquinone and the like.
(D) Organic sulfur compounds Dilauryl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, ditetradecyl-3,3′-thiodipropionate, and the like.
(E) Organic phosphorus compounds Triphenylphosphine, tri (nonylphenyl) phosphine, tri (dinonylphenyl) phosphine, tricresylphosphine, tri (2,4-dibutylphenoxy) phosphine and the like.

Examples of the lubricant include the following.
(A) Hydrocarbon compounds Liquid paraffin, paraffin wax, microwax, low-polymerized polyethylene and the like.
(B) Fatty acid compounds Lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid and the like.
(C) Fatty acid amide compounds Stearylamide, palmitylamide, oleinamide, methylenebisstearamide, ethylenebisstearamide and the like.
(D) Ester compounds Lower alcohol esters of fatty acids, polyhydric alcohol esters of fatty acids, fatty acid polyglycol esters, and the like.
(E) Alcohol compounds Cetyl alcohol, stearyl alcohol, ethylene glycol, polyethylene glycol, polyglycerol and the like.
(F) Metal soap Lead stearate, cadmium stearate, barium stearate, calcium stearate, zinc stearate, magnesium stearate and the like.
(G) Natural wax Carnauba wax, candelilla wax, beeswax, whale wax, ivotaro, montan wax and the like.
(H) Others Silicone compounds, fluorine compounds, etc.

Examples of the ultraviolet absorber include the following.
(A) Benzophenone series 2-hydroxybenzophenone, 2,4-dihydroxybenzophenone, 2,2 ′, 4-trihydroxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2,2′-dihydroxy-4- Such as methoxybenzophenone.
(B) Salsylate type Phenyl salsylate, 2,4-di-t-butylphenyl-3,5-di-t-butyl-4-hydroxybenzoate, and the like.
(C) benzotriazole-based (2′-hydroxyphenyl) benzotriazole, (2′-hydroxy-5′-methylphenyl) benzotriazole, (2′-hydroxy-5′-methylphenyl) benzotriazole, (2′- Hydroxy-3'-tertiarybutyl-5'-methylphenyl) 5-chlorobenzotriazole and the like.
(D) Cyanoacrylate-based ethyl-2-cyano-3,3-diphenyl acrylate, methyl-2-carbomethoxy-3- (paramethoxy) acrylate, and the like.
(E) Quencher (metal complex)
Nickel (2,2′thiobis (4-t-octyl) phenolate) normal butylamine, nickel dibutyldithiocarbamate, nickel dibutyldithiocarbamate, cobalt dicyclohexyldithiophosphate and the like.
(F) HALS (hindered amine)
Bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1- [2- [3- (3 5-di-t-butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6 6-tetramethylpyridine, 8-benzyl-7,7,9,9-tetramethyl-3-octyl-1,3,8-triazaspiro [4,5] undecane-2,4-dione, 4-benzoyloxy- 2,2,6,6-tetramethylpiperidine and the like.

  These additives including these plasticizers and leveling agents are known as additives such as rubbers, plastics, fats and oils, and commercially available products can be easily obtained.

<Image Forming Method, Image Forming Apparatus>
The image forming method of the present invention uses the electrophotographic photosensitive member of the present invention. For example, at least after the photosensitive member is charged, exposed to an image, and developed, the toner image is transferred to an image carrier (transfer paper). Further, if necessary, the process includes fixing and cleaning the surface of the photoreceptor. The image forming apparatus of the present invention uses the electrophotographic photosensitive member having the crosslinkable charge transport layer of the present invention. For example, after at least charging, image exposure, and developing means are applied to the photosensitive member, the image holding member ( It comprises means for transferring the toner image onto the transfer paper) and, if necessary, means for fixing and cleaning the surface of the photoreceptor. The image forming apparatus of the present invention may be configured such that a plurality of image forming elements including at least a charging unit, an exposure unit, a developing unit, a transfer unit, and an electrophotographic photosensitive member are arranged.

FIG. 4 is a schematic diagram illustrating an example of an image forming apparatus.
A charging charger (3) is used as means for charging the photosensitive member. As the charging means, a corotron device, a scorotron device, a solid discharge element, a needle electrode device, a roller charging device, a conductive brush device, or the like is used, and a known method can be used. In particular, the configuration of the present invention is particularly effective when a charging unit such as a contact charging method or a non-contact proximity charging method that generates a proximity discharge from the charging unit that causes decomposition of the photoreceptor composition is used. It is. The contact charging method referred to here is a charging method in which a charging roller, a charging brush, a charging blade, or the like is in direct contact with the photosensitive member. On the other hand, the proximity charging method is, for example, a type in which the charging roller is arranged in a non-contact state so as to have a gap of 200 μm or less between the surface of the photoreceptor and the charging means. If this gap is too large, the charging tends to become unstable, and if it is too small, the surface of the charging member may be contaminated when toner remaining on the photoreceptor exists. is there. Accordingly, the gap is suitably 10 to 200 μm, preferably 10 to 100 μm.
Next, the image exposure unit (5) is used to form an electrostatic latent image on the charged photoconductor (1). As the light source, all luminescent materials such as a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), and an electroluminescence (EL) can be used. Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.

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

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

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

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

Next, a neutralizing unit is used for the purpose of removing the latent image on the photoreceptor as required. As the charge removal means, a charge removal lamp (2) and a charge removal charger are used, and the exposure light source and the charging means can be used respectively. In addition, known processes can be used for reading, feeding, fixing, paper discharge and the like that are not close to the photoconductor.
The present invention is an image forming method and an image forming apparatus using the electrophotographic photoreceptor according to the present invention for such image forming means. The image forming means may be fixedly incorporated in a copying apparatus, facsimile, or printer, but may be incorporated in these apparatuses in the form of a process cartridge and detachable.

<Process cartridge>
The process cartridge of the present invention comprises the electrophotographic photosensitive member of the present invention and at least one means selected from the group consisting of a charging means, a developing means, a transfer means, a cleaning means, and a charge eliminating means, and an image forming apparatus main body It is designed to be detachable.
An example of the process cartridge is shown in FIG.
The process cartridge for the image forming apparatus includes a photoreceptor (101), and in addition, a charging unit (102), a developing unit (104), a transfer unit (106), a cleaning unit (107), and a discharging unit (not shown). ), And an apparatus (part) that can be attached to and detached from the image forming apparatus main body. Referring to the image forming process by the apparatus illustrated in FIG. 5, the surface of the photoreceptor (101) is exposed by charging by the charging means (102) and exposure by the exposure means (103) while rotating in the direction of the arrow. An electrostatic latent image corresponding to the image is formed, and the electrostatic latent image is developed with toner by the developing means (104). The toner development is transferred to the transfer body (105) by the transfer means (106), and printed. Be out. Next, the surface of the photoconductor after the image transfer is cleaned by a cleaning unit (107), and further neutralized by a neutralizing unit (not shown), and the above operation is repeated again.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated, this invention is not restrict | limited by an Example. All parts are parts by weight.
First, a synthesis example of a charge generating material (titanyl phthalocyanine crystal) will be described.

(Synthesis of titanyl phthalocyanine crystal)
First, a method for synthesizing the titanyl phthalocyanine crystal used in the present invention will be described. The synthesis was in accordance with Japanese Patent Application Laid-Open No. 2004-83859. That is, 292 parts of 1,3-diiminoisoindoline and 1800 parts of sulfolane are mixed, and 204 parts of titanium tetrabutoxide are 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 the reaction is complete, the mixture is allowed to cool, and then the precipitate is filtered, washed with chloroform until the powder turns blue, then washed several times with methanol, then washed several times with hot water at 80 ° C. and dried. Crude titanyl phthalocyanine was obtained. Crude titanyl phthalocyanine is dissolved in 20 times the amount of concentrated sulfuric acid, added dropwise to 100 times the amount of ice water with stirring, the precipitated crystals are filtered, and then ion-exchanged water (pH: 7.) until the washing solution becomes neutral. 0, specific conductivity: 1.0 μS / cm) Repeated washing with water (pH value of ion-exchanged water after washing was 6.8, specific conductivity was 2.6 μS / cm), wet of titanyl phthalocyanine pigment A cake (water paste) was obtained.

  40 parts of this wet cake (water paste) thus obtained was put into 200 parts of tetrahydrofuran and stirred vigorously (2000 rpm) with a homomixer (Kennis, MARKIIf model) at room temperature, and the dark blue color of the paste turned pale blue. When changed (20 minutes after the start of stirring), stirring was stopped and filtration under reduced pressure was immediately performed. The crystals obtained on the filtration device were washed with tetrahydrofuran to obtain a wet cake of pigment. This was dried under reduced pressure (5 mmHg) at 70 ° C. for 2 days to obtain 8.5 parts of titanyl phthalocyanine crystals. The solid content concentration of the wet cake was 15% by mass. The crystal conversion solvent was used in a mass ratio of 33 times that of the wet cake. Note that halogen-containing compounds are not used as raw materials for synthesis. When the obtained titanyl phthalocyanine powder was subjected to X-ray diffraction spectrum measurement under the following conditions, the Bragg angle 2θ with respect to CuKα ray (wavelength 1.542１．５) was 27.2 ± 0.2 °, and the maximum peak and the minimum angle 7.3. It has a peak at ± 0.2 °, and further has major peaks at 9.4 ± 0.2 °, 9.6 ± 0.2 °, 24.0 ± 0.2 °, and 7.3 A titanyl phthalocyanine powder having no peak between the peak at 0 ° and the peak at 9.4 ° and further having no peak at 26.3 ° was obtained. The result is shown in FIG.

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

[Example 1]
Using an undercoat layer coating solution described below on an Al support (outer diameter 60 mmφ), coating is performed by dipping so that the film thickness after drying at 130 ° C. for 20 minutes is 3.5 μm. A layer was formed.
<Undercoat layer coating solution>
Titanium dioxide powder (Ishihara Sangyo Co., Ltd., Taibake CR-EL): 400 parts Melamine resin (DIC, Super Becamine G821-60): 65 parts Alkyd resin (DIC, Beckolite M6401-50): 120 parts 2-butanone: 400 parts

On the undercoat layer formed above, dip coating was performed using the following charge generation layer coating solution, followed by heating and drying at 90 ° C. for 20 minutes to form a charge generation layer having a thickness of 0.2 μm.
<Charge generation layer coating solution>
Titanylphthalocyanine: 8 parts Polyvinyl butyral (manufactured by Sekisui Chemical Co., Ltd., BX-1): 5 parts 2-butanone: 400 parts

テロラヒドロフラン： １００部 On this charge generation layer, dip coating is performed using a charge transport layer coating solution containing a charge transport material having the following structure, followed by heating and drying at 120 ° C. for 20 minutes to form a charge transport layer having a thickness of 23 μm. did.
<Coating liquid for charge transport layer>
Z-type polycarbonate (manufactured by Teijin Chemicals Ltd., TS-2050): 10 parts Charge transport material having the following structure: 9 parts

Terrorahydrofuran: 100 parts

The charge transport layer is spray-coated using a crosslinked surface layer coating solution having the following constitution, and light irradiation is performed under the conditions of a metal halide lamp, irradiation intensity: 500 mW / cm ² , irradiation time: 160 seconds, and further 130 Drying was carried out at 30 ° C. for 30 minutes to provide a 4.0 μm cross-linked surface layer to obtain the electrophotographic photosensitive member of the present invention.
<Crosslinked surface layer coating solution>
Radical polymerizable monomer (trimethylolpropane acrylate)
(Nippon Kayaku Co., Ltd., KAYARAD TMPTA): 10 parts Compound 2: 10 parts Photopolymerization initiator (Ciba Specialty Chemicals, Irgacure 184): 1 part Tetrahydrofuran: 100 parts

[Example 2]
In Example 1, no. 2 instead of 10 parts of the above compound. The electrophotographic photosensitive member of the present invention was obtained in the same manner as in Example 1 except that 10 parts of the compound No. 3 was used.

Example 3
In Example 1, no. 2 instead of 10 parts of the above compound. The electrophotographic photosensitive member of the present invention was obtained in the same manner as in Example 1 except that 10 parts of the compound No. 5 was used.

Example 4
A photoreceptor of the present invention was produced in the same manner as in Example 1 except that the crosslinked surface layer coating solution had the following composition.
<Crosslinked surface layer coating solution>
Radical polymerizable monomer (trimethylolpropane acrylate)
(Nippon Kayaku Co., Ltd., KAYARAD TMPTA): 10 parts Compound of 2: 10 parts Photopolymerization initiator (Ciba Specialty Chemicals, Irgacure 184): 1 part Alumina fine particles (Sumitomo Chemical Co., AA02): 5 parts Tetrahydrofuran: 100 parts

Example 5
A photoreceptor of the present invention was produced in the same manner as in Example 1 except that the crosslinked surface layer coating solution had the following composition.
<Crosslinked surface layer coating solution>
Radical polymerizable monomer (trimethylolpropane acrylate)
(Nippon Kayaku Co., Ltd., KAYARAD TMPTA): 10 parts Compound of 8: 10 parts Photopolymerization initiator (Ciba Specialty Chemicals, Irgacure 184): 1 part Alumina fine particles (Sumitomo Chemical Co., AA02): 5 parts Tetrahydrofuran: 100 parts

Example 6
In Example 1, no. 2 instead of 10 parts of the above compound. The electrophotographic photosensitive member of the present invention was obtained in the same manner as in Example 1 except that 10 parts of the 10 compounds were used.

Example 7
In Example 1, no. 2 instead of 10 parts of the above compound. An electrophotographic photosensitive member of the present invention was obtained in the same manner as in Example 1 except that 10 parts of 12 compounds were used.

Example 8
A photoreceptor of the present invention was produced in the same manner as in Example 1 except that the crosslinked surface layer coating solution had the following composition.
<Crosslinked surface layer coating solution>
Radical polymerizable monomer (trimethylolpropane acrylate)
(Nippon Kayaku Co., Ltd., KAYARAD TMPTA): 10 parts 10 compounds: 10 parts Photopolymerization initiator (Ciba Specialty Chemicals, Irgacure 184): 1 part Alumina fine particles (Sumitomo Chemical Co., AA02): 5 parts Tetrahydrofuran: 100 parts

Example 9
A photoreceptor of the present invention was produced in the same manner as in Example 1 except that the crosslinked surface layer coating solution had the following composition.
<Crosslinked surface layer coating solution>
Radical polymerizable monomer (trimethylolpropane acrylate)
(Nippon Kayaku Co., Ltd., KAYARAD TMPTA): 10 parts 13 compounds: 10 parts Photopolymerization initiator (Ciba Specialty Chemicals, Irgacure 184): 1 part Alumina fine particles (Sumitomo Chemical Co., AA02): 5 parts Tetrahydrofuran: 100 parts

Example 10
In Example 1, no. 2 instead of 10 parts of the above compound. An electrophotographic photoreceptor of the present invention was obtained in the same manner as in Example 1 except that 10 parts of 16 compounds were used.

Example 11
In Example 1, no. 2 instead of 10 parts of the above compound. An electrophotographic photosensitive member of the present invention was obtained in the same manner as in Example 1 except that 10 parts of Compound No. 17 was used.

光重合開始剤（チバ・スペシャルティ・ケミカルズ社製、イルガキュア１８４）：１部
テトラヒドロフラン： １００部 [Comparative Example 1]
A comparative photoreceptor was prepared in the same manner as in Example 1 except that the crosslinked surface layer coating solution had the following composition.
<Crosslinked surface layer coating solution>
Radical polymerizable monomer (trimethylolpropane acrylate)
(Nippon Kayaku Co., Ltd., KAYARAD TMPTA): 10 parts Compound having the following structure: 10 parts

Photopolymerization initiator (Ciba Specialty Chemicals, Irgacure 184): 1 part Tetrahydrofuran: 100 parts

光重合開始剤（チバ・スペシャルティ・ケミカルズ社製、イルガキュア１８４）：１部
テトラヒドロフラン： １００部 [Comparative Example 2]
A comparative photoreceptor was prepared in the same manner as in Example 1 except that the crosslinked surface layer coating solution had the following composition.
<Crosslinked surface layer coating solution>
Radical polymerizable monomer (trimethylolpropane acrylate)
(Nippon Kayaku Co., Ltd., KAYARAD TMPTA): 10 parts Compound having the following structure: 10 parts

Photopolymerization initiator (Ciba Specialty Chemicals, Irgacure 184): 1 part Tetrahydrofuran: 100 parts

光重合開始剤（チバ・スペシャルティ・ケミカルズ社製、イルガキュア１８４）：１部
アルミナ微粒子（住友化学社製、ＡＡ０２）： ５部
テトラヒドロフラン： １００部 [Comparative Example 3]
A comparative photoreceptor was prepared in the same manner as in Example 1 except that the crosslinked surface layer coating solution had the following composition.
<Crosslinked surface layer coating solution>
Radical polymerizable monomer (trimethylolpropane acrylate)
(Nippon Kayaku Co., Ltd., KAYARAD TMPTA): 10 parts Compound having the following structure: 10 parts

Photopolymerization initiator (Ciba Specialty Chemicals, Irgacure 184): 1 part Alumina fine particles (Sumitomo Chemical Co., AA02): 5 parts Tetrahydrofuran: 100 parts

光重合開始剤（チバ・スペシャルティ・ケミカルズ社製、イルガキュア１８４）：１部
アルミナ微粒子（住友化学社製、ＡＡ０２）： ５部
テトラヒドロフラン： １００部 [Comparative Example 4]
A comparative photoreceptor was prepared in the same manner as in Example 1 except that the crosslinked surface layer coating solution had the following composition.
<Crosslinked surface layer coating solution>
Radical polymerizable monomer (trimethylolpropane acrylate)
(Nippon Kayaku Co., Ltd., KAYARAD TMPTA): 10 parts Compound having the following structure: 10 parts

Photopolymerization initiator (Ciba Specialty Chemicals, Irgacure 184): 1 part Alumina fine particles (Sumitomo Chemical Co., AA02): 5 parts Tetrahydrofuran: 100 parts

光重合開始剤（チバ・スペシャルティ・ケミカルズ社製、イルガキュア１８４）：１部
テトラヒドロフラン： １００部 [Comparative Example 5]
A comparative photoreceptor was prepared in the same manner as in Example 1 except that the crosslinked surface layer coating solution had the following composition.
<Crosslinked surface layer coating solution>
Radical polymerizable monomer (trimethylolpropane acrylate)
(Nippon Kayaku Co., Ltd., KAYARAD TMPTA): 10 parts Compound having the following structure: 10 parts

Photopolymerization initiator (Ciba Specialty Chemicals, Irgacure 184): 1 part Tetrahydrofuran: 100 parts

光重合開始剤（チバ・スペシャルティ・ケミカルズ社製、イルガキュア１８４）：１部
アルミナ微粒子（住友化学社製、ＡＡ０２）： ５部
テトラヒドロフラン： １００部 [Comparative Example 6]
A comparative photoreceptor was prepared in the same manner as in Example 1 except that the crosslinked surface layer coating solution had the following composition.
<Crosslinked surface layer coating solution>
Radical polymerizable monomer (trimethylolpropane acrylate)
(Nippon Kayaku Co., Ltd., KAYARAD TMPTA): 10 parts Compound having the following structure: 10 parts

Photopolymerization initiator (Ciba Specialty Chemicals, Irgacure 184): 1 part Alumina fine particles (Sumitomo Chemical Co., AA02): 5 parts Tetrahydrofuran: 100 parts

[Evaluation]
The photoreceptors produced in the examples and comparative examples were evaluated.
A process cartridge equipped with the photoconductors of Examples 1 to 11 and Comparative Examples 1 to 6 is mounted on a remodeling machine of a tandem type full-color digital copying machine imagio MPC7500 (manufactured by Ricoh), and a writing rate 5% chart (A4 On the entire surface, a printing durability test was performed to print 200,000 sheets in total using characters equivalent to 5% as an image area). At that time, the initial portion and the exposed portion potential (VL) after the printing durability test, the fluctuation in the job, the image quality, and the wear amount were evaluated.
In order to evaluate the variation in the job, first, the exposed portion potential (VL) of the photosensitive member was measured using a surface potentiometer, and then the continuous printing of 50 sheets was set to 1 Job, and this was repeated 10 times, and then the exposed portion potential was measured again. Was measured, and <VL after repeated printing>-<first VL> was evaluated as variation within the job. In addition to the measurement value, a determination result as to whether or not the correction range is available for use in the process is shown.

・ Judgment criteria for fluctuation within job ◎: Level that does not cause any problem ○: Level that changes slightly, but does not cause a problem within the range that can be corrected △: Level that changes are clearly recognized and slightly exceeds the allowable range ×: Large change , Problematic level

  For the evaluation of the amount of wear, the film thickness at 20 points on the photoconductor was measured with an eddy current film thickness meter (Fisher scope MMS), and the amount of film thickness reduction from the initial stage was obtained.

The evaluation results are shown in Table 1.

From the evaluation results, the photoconductors of Examples 1 to 15 have stable photoconductor characteristics even after printing 200,000 sheets, an increase in exposure part potential (VL) and fluctuations in the job are suppressed, and image quality is also good. I understand that.
On the other hand, the photoconductors of Comparative Examples 1 to 4 have poor image quality such as image blurring after printing 200,000 sheets, and the fluctuation in the job becomes large. The photoconductors of Comparative Examples 5 and 6 can obtain a good image even after printing 200,000 sheets. However, fluctuations in the job cannot be suppressed, and in the case where the same image is output continuously, the image density and color tone are not good. Change will occur.

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Static elimination lamp 3 Charger charger 5 Image exposure part 6 Developing unit 7 Charger before transfer 8 Registration roller 9 Transfer body 10 Transfer charger 11 Separation charger 12 Separation claw 13 Charger before cleaning 14 Fur brush 15 Cleaning blade 31 Conductive support 33 Photosensitive layer 35 Charge generation layer 37 Charge transport layer 39 Crosslinked surface layer 101 Photoconductor 102 Charging means 103 Exposure means 104 Development means 105 Transfer body 106 Transfer means 107 Cleaning means

Japanese Patent Laid-Open No. 2006-154796 JP 2007-178813 A JP 09-236938 A JP 2003-043706 A Japanese Patent Laid-Open No. 2006-13895 Japanese Patent Laying-Open No. 2005-063022

Claims (6)

An electrophotographic photosensitive film comprising at least a photosensitive layer and a crosslinked surface layer on a conductive support, wherein the crosslinked surface layer contains at least a compound represented by the general formula (1) and a crosslinked polymer. body.

[In the formula (1), R1 to R3 may each independently have a substituent of any of an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a halogen atom. Represents a phenyl group, a biphenyl group or a condensed polycyclic hydrocarbon group, and at least one of R1 to R3 is a substitution of any one of an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a halogen atom A condensed polycyclic hydrocarbon group which may have a group; ]   The electrophotographic photosensitive member according to claim 1, wherein the crosslinked surface layer is a crosslinked film cured by light energy irradiation.   The electrophotographic photosensitive member according to claim 1, wherein the crosslinked surface layer contains inorganic fine particles.   An image forming method, wherein at least charging, image exposure, development, and transfer are repeated using the electrophotographic photosensitive member according to claim 1.   An image comprising at least an electrophotographic photosensitive member, a charging unit, an exposing unit, a developing unit, and a transferring unit, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to claim 1. Forming equipment.   An image forming apparatus comprising: the electrophotographic photosensitive member according to claim 1; and at least one unit selected from the group consisting of a charging unit, a developing unit, a transfer unit, a cleaning unit, and a discharging unit. A process cartridge which is detachable from the main body.

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