JP2012108255A - Image forming apparatus and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus that restrains occurrence of image flow in a contact charging system.SOLUTION: The image forming apparatus has an electrophotographic photoreceptor in which the outermost layer comprises a cross-linked product using at least one type of a compound expressed by general formula (I) below and the moisture content of the outermost layer, measured by thermal analysis, is 0.3 mass% or more but 0.5 mass% or less. F-((-R1-X)R2-Y), general formula (I), in which F is an organic group derived from a compound having hole transportability, R1 and R2 each independently represent a linear or branched-chain alkylene group having one or more but five or fewer carbons, n1 is an integer of 0 or 1, and n2 is an integer of 1 or greater but 4 or smaller. X represents one selected from a group consisting of an oxygen atom, NH, and sulfur atom, and Y represents a group selected from a group consisting of -OH, -OCH, -NH, -SH, and -COOH).

Description

  The present invention relates to an image forming apparatus and a process cartridge.

  In recent years, a so-called xerographic image forming apparatus having a charging unit, an exposure unit (electrostatic latent image forming unit), a developing unit, a transfer unit, and a fixing unit has been further increased in speed due to technical development of each member and system. Long life has been achieved. As a result, the demand for high-speed compatibility and high reliability of each subsystem is higher than before. In particular, the electrophotographic photosensitive member used for image writing receives a lot of electrical and mechanical external forces from a charger, a developing device, a transfer device, a cleaning device, and the like, so image defects due to scratches, abrasion, chipping, etc. There is a strong demand for high-speed compatibility and high reliability.

  In order to suppress such scratches and wear, a resin having high mechanical strength is used in the electrophotographic photosensitive member, and the life is further extended. For example, in Patent Document 1, a photoconductor using an epoxy resin as a binder resin is used, and in Patent Document 2, a charge transport material having an epoxy resin and an epoxy group is used. In Patent Documents 3 and 4, a charge transport material having a phenol resin and a hydroxyl group in the protective layer is used.

  In addition, in order to provide an electrophotographic photosensitive member that has a low residual potential and does not increase even after repeated use, an amorphous photoconductive layer, a charge injection blocking layer, and a protective layer are sequentially laminated on the conductive support. An electrophotographic photosensitive member is disclosed in which the water content of the protective layer is 0.2% by mass or more and 2.5% by mass or less (see, for example, Patent Document 5). ).

  Further, in order to provide an electrophotographic photosensitive member capable of obtaining a high-quality image with no image blur due to a decrease in resistance of the protective layer and a low flow without causing image fogging under low humidity. In an electrophotographic photosensitive member having a photosensitive layer and a protective layer on a support, the moisture content of the protective layer is 2% by mass or less in any environment where the temperature is 15 ° C. or higher and 30 ° C. or lower / humidity 10% RH or higher and 80% RH or lower. An electrophotographic photosensitive member is disclosed (see, for example, Patent Document 6).

JP-A-56-51749 JP-A-8-278645 JP 2002-82469 A JP 2003-186234 A Japanese Patent Laid-Open No. 06-035219 JP 2000-305301 A

  An object of the present invention is to provide an image forming apparatus in which the occurrence of image flow in the contact charging method is suppressed.

That is, the invention according to claim 1
Crosslinking using a substrate and a plurality of layers formed on the substrate, wherein the outermost surface layer of the plurality of layers uses at least one curable charge transporting material represented by the following general formula (I) And an electrophotographic photoreceptor having a water content measured by thermal analysis of the outermost surface layer of 0.3% by mass or more and 0.5% by mass or less,
A charging roll for contacting the electrophotographic photosensitive member, and charging means for charging the electrophotographic photosensitive member;
Electrostatic latent image forming means for forming an electrostatic latent image on the charged electrophotographic photosensitive member;
Developing means for developing the electrostatic latent image formed on the electrophotographic photosensitive member with toner to form a toner image;
Transfer means for transferring the toner image formed on the electrophotographic photosensitive member to a transfer target;
And a toner removing unit for removing toner remaining on the electrophotographic photosensitive member.

F-((-R1-X) _n1R2 -Y) _n2 general formula (I)

(In general formula (I), F represents an organic group derived from a compound having a hole transporting ability, and R1 and R2 each independently represents a linear or branched alkylene group having 1 to 5 carbon atoms. N1 is 0 or 1, and n2 is an integer of 1 to 4. X represents any one selected from an oxygen atom, NH, and a sulfur atom, and Y represents —OH, —OCH ₃ , — NH _2, shows one group selected -SH, and from -COOH.)

The invention according to claim 2
2. The image forming apparatus according to claim 1, wherein a content of the charge transporting material in the outermost surface layer is 90% by mass or more and 99% by mass or less.

The invention according to claim 3
Crosslinking using a substrate and a plurality of layers formed on the substrate, wherein the outermost surface layer of the plurality of layers uses at least one curable charge transporting material represented by the following general formula (I) And an electrophotographic photoreceptor having a water content measured by thermal analysis of the outermost surface layer of 0.3% by mass or more and 0.5% by mass or less,
A process cartridge comprising a charging roll in contact with the electrophotographic photosensitive member, and charging means for charging the electrophotographic photosensitive member.

F-((-R1-X) _n1R2 -Y) _n2 general formula (I)

(In general formula (I), F represents an organic group derived from a compound having a hole transporting ability, and R1 and R2 each independently represents a linear or branched alkylene group having 1 to 5 carbon atoms. N1 is 0 or 1, and n2 is an integer of 1 to 4. X represents any one selected from an oxygen atom, NH, and a sulfur atom, and Y represents —OH, —OCH ₃ , — NH _2, shows one group selected -SH, and from -COOH.)

  According to the first aspect of the present invention, there is provided an image forming apparatus in which the occurrence of image flow in the contact charging method is suppressed.

  According to the invention of claim 2, the electrical characteristics and strength of the electrophotographic photosensitive member are improved.

  According to the third aspect of the present invention, there is provided a process cartridge in which the occurrence of image flow in the contact charging method is suppressed.

1 is an overall configuration diagram illustrating a first example of an image forming apparatus according to an exemplary embodiment. It is a schematic diagram which shows the cross section of the electrophotographic photoreceptor which concerns on this embodiment. It is a whole block diagram which shows the 2nd example of the image forming apparatus which concerns on this embodiment.

  Hereinafter, embodiments of an image forming apparatus and a process cartridge according to the present invention will be described.

  The image forming apparatus according to the present embodiment includes a substrate and a plurality of layers formed on the substrate, and the outermost surface layer of the plurality of layers has a curable charge represented by the following general formula (I). An electrophotographic photosensitive material comprising a cross-linked product using at least one transport material and having a water content of 0.3% by mass or more and 0.5% by mass or less measured by thermal analysis of the outermost surface layer. A charging means for charging the electrophotographic photosensitive member, and an electrostatic latent image forming means for forming an electrostatic latent image on the charged electrophotographic photosensitive member. Developing means for developing the electrostatic latent image formed on the electrophotographic photosensitive member with toner to form a toner image, and transfer for transferring the toner image formed on the electrophotographic photosensitive member to the transfer target And a toner remaining on the electrophotographic photosensitive member. Having a toner removing means for.

F-((-R1-X) _n1R2 -Y) _n2 general formula (I)

In general formula (I), F represents an organic group derived from a compound having a hole transporting ability, and R1 and R2 each independently represents a linear or branched alkylene group having 1 to 5 carbon atoms. , N1 is 0 or 1, and n2 is an integer of 1 or more and 4 or less. X represents any one selected from an oxygen atom, NH, and a sulfur atom, and Y represents any group selected from —OH, —OCH ₃ , —NH ₂ , —SH, and —COOH.

When the outermost surface layer of the electrophotographic photoreceptor includes a cross-linked product using at least one of the curable charge transporting materials represented by the general formula (I), the wear resistance of the outermost surface layer is improved. Therefore, the occurrence of image defects due to scratches, abrasion, chipping, etc. on the outermost surface layer is suppressed. Furthermore, the electrical characteristics of the photoreceptor are improved.
In this embodiment, a charging roll that contacts the electrophotographic photosensitive member is used as the charging unit. According to the contact charging method using a charging roll, there is an advantage that the amount of ozone generation during charging can be reduced. In addition, there are advantages of low cost and space saving.
However, when charging an electrophotographic photosensitive member having an outermost surface layer containing a cross-linked product using at least one of the curable charge transporting materials represented by the general formula (I) by a contact charging method, Discharge products are likely to be generated on the surface of the photoconductor. The presence of discharge products on the surface of the electrophotographic photoreceptor can cause image drift problems.
As a result of intensive studies, the present inventors have made the image content problem to be 0.3 mass% or more and 0.5 mass% or less by measuring the moisture content measured by thermal analysis of the outermost surface layer of the electrophotographic photosensitive member. I found it to be solved.

The reason why the image flow problem can be solved by setting the moisture content within a specific range is not clear, but is presumed as follows.
Since the problem of image flow is caused by the presence of discharge products on the surface of the electrophotographic photosensitive member, it is important to remove the discharge products. When the water content of the outermost surface layer of the electrophotographic photosensitive member is within the above specific range, the outermost surface layer has flexibility, so that the discharge product can be easily removed by toner removing means such as a cleaning blade. Therefore, it is presumed that the occurrence of image flow is suppressed.

  If the water content of the outermost surface layer is less than 0.3% by mass, the outermost surface layer may have poor flexibility and may cause image flow problems. On the other hand, if the water content of the outermost surface layer exceeds 0.5% by mass, problems with electrical characteristics may occur.

  The water content of the outermost surface layer refers to a value obtained by simultaneous differential thermo-thermogravimetric measurement (TG-DTA).

  Hereinafter, the image forming apparatus according to the present embodiment will be described in more detail with reference to the drawings. In addition, the same code | symbol is provided to the member which has the same function throughout all drawings, and the description may be abbreviate | omitted.

FIG. 1 is an overall configuration diagram illustrating a first example of an image forming apparatus according to the present embodiment.
The image forming apparatus 1000 is a monochrome single-sided output printer that employs an electrophotographic system.

  The image forming apparatus 1000 receives an electric power supplied from a power source 65a and rotates while contacting the image holding body 61 by receiving power from an image holding body 61 that is an electrophotographic photosensitive member rotating in the direction of arrow B in the figure. And a charging member (charging roll) 65 as charging means for charging the surface of the holding body.

  Further, this image forming apparatus 1000 is an exposure that is an electrostatic latent image forming unit that emits laser light toward the image holding member 61 and forms an electrostatic latent image on the surface of the image holding member 61 according to image information. The toner image is formed by developing the electrostatic latent image by attaching a monochrome (black) toner to the electrostatic latent image formed on the surface of the image holding member 61 using a developer including a black toner. The toner image formed on the surface of the image carrier 61 is pressed by the developer 64 as an image forming unit (developing unit) and the image carrier 61 on which the toner image is formed by pressing the conveyed paper. A transfer roll 50 which is a transfer means for transferring onto a sheet of paper, and a fixing device 10 which is a fixing means for fixing the transfer image to the paper by applying heat and pressure to the toner image transferred onto the paper; Contact the image carrier 61 and Also provided is a cleaning device 62 that is a cleaning unit that removes residual toner remaining on the surface of the image carrier 61 after the transfer of the image, and a static elimination lamp 7a that removes the charge remaining on the image carrier 61 after the transfer of the toner image. ing.

  In the image forming apparatus 1000, the charging member 65 and the image holding member 61 are each in the form of a roll extending in a direction perpendicular to FIG. 1, and both ends of these rolls are on the support member 100a. The roll is supported in a rotatable manner. Further, the cleaning device 62 and the developing device 64 described above are also connected to the support member 100a. Thus, the charging member 65, the image holding member 61, the cleaning device 62, and the developing device 64 are connected to the support member 100a. By being integrated, the process cartridge 100 is configured.

  By incorporating this process cartridge into the image forming apparatus 1000, the image forming apparatus 1000 is provided with each part that is a component of these process cartridges. This process cartridge 100 corresponds to an example of the process cartridge of the present embodiment.

Hereinafter, an image forming operation in the image forming apparatus 1000 will be described.
The image forming apparatus 1000 includes a toner cartridge (not shown) in which black toner is stored, and the toner is supplied to the developing device 64 by the toner cartridge. Further, the paper used for transferring the toner image is stored in the paper storage member 1, and is conveyed from the paper storage member 1 when the image formation is instructed by the user. After the image is transferred, it is conveyed toward the left in the figure. In FIG. 1, the sheet conveyance path at this time is shown as a path indicated by a left-pointing arrow, and the sheet passes through the sheet conveyance path and is fixed on the sheet by the fixing device 10. After being done, it is discharged to the left.

  When the charging member 65 charges the image holding member 61, a voltage is applied to the charging member 65. As the voltage range, the DC voltage is preferably positive or negative 50 V or more and 2000 V or less, more preferably 100 V or more and 1500 V or less, depending on the required charging potential of the image carrier. When the AC voltage is superimposed, the peak-to-peak voltage is 400 V to 1800 V, preferably 800 V to 1600 V, and more preferably 1200 V to 1600 V. The frequency of the AC voltage is 50 Hz to 20,000 Hz, preferably 100 Hz to 5,000 Hz.

  As the charging member 65, a charging roll in which a conductive elastic layer, a surface layer, and the like are provided on the outer peripheral surface of the conductive support is suitably used. The charging member 65 rotates at the same peripheral speed as the image holding member 61 by contacting the image holding member 61 without contacting the image holding member 61, and functions as a charging unit. However, the driving member is attached to the charging member 65. The image carrier 61 may be charged by being rotated at a peripheral speed different from that of the image carrier 61.

  The conductive support constituting the charging roll functions as an electrode and a supporting member for the charging roll. For example, a metal or an alloy such as aluminum, copper alloy, stainless steel, or iron subjected to a plating treatment with chromium, nickel, or the like A conductive material such as a conductive resin.

The conductive elastic layer is formed, for example, by dispersing a conductive agent in a rubber material.
Rubber materials include isoprene rubber, chloroprene rubber, epichlorohydrin rubber, butyl rubber, polyurethane, silicone rubber, fluorine rubber, styrene-butadiene rubber, butadiene rubber, nitrile rubber, ethylene propylene rubber, epichlorohydrin-ethylene oxide copolymer rubber, epichlorohydrin-ethylene oxide- Examples include allyl glycidyl ether copolymer rubber, ethylene-propylene-diene terpolymer rubber (EPDM), acrylonitrile-butadiene copolymer rubber (NBR), natural rubber, and blend rubbers thereof. Among these, polyurethane, silicone rubber, EPDM, epichlorohydrin-ethylene oxide copolymer rubber, epichlorohydrin-ethylene oxide-allyl glycidyl ether copolymer rubber, NBR and blended rubbers thereof are desirably used. These rubber materials may be foamed or non-foamed.

As the conductive agent, an electronic conductive agent or an ionic conductive agent is used. Examples of electronic conductive agents include carbon blacks such as ketjen black and acetylene black; pyrolytic carbon, graphite; various conductive metals or alloys such as aluminum, copper, nickel, and stainless steel; tin oxide, indium oxide, titanium oxide And various conductive metal oxides such as tin oxide-antimony oxide solid solution, tin oxide-indium oxide solid solution; and the like. Examples of ionic conductive agents include perchlorates and chlorates such as tetraethylammonium and lauryltrimethylammonium; alkali metals such as lithium and magnesium; perchlorates and chlorates of alkaline earth metals Can be mentioned.
These conductive agents may be used alone or in combination of two or more.
In particular, when the conductive elastic layer is the outermost layer, it is desirable to contain the following two types of carbon black (a) and (b) as the conductive agent.
(A) Specific surface area: 400 m ² / g or less and pH: 4.0 or less (b) Specific surface area: greater than 400 m ² / g and pH: 4.0 or less

  The amount of the conductive agent added is not particularly limited, but in the case of the electronic conductive agent, it is preferably in the range of 1 part by mass to 30 parts by mass with respect to 100 parts by mass of the rubber material, and 15 parts by mass. It is more desirable that the range be 25 parts by mass or less. On the other hand, in the case of the ionic conductive agent, the range of 0.1 parts by mass or more and 5.0 parts by mass or less is desirable with respect to 100 parts by mass of the rubber material, and 0.5 parts by mass or more and 3.0 parts by mass. The following range is more desirable.

  The thickness of the conductive elastic layer is not particularly limited, but may be, for example, about 1.0 mm to 4.5 mm, or about 1.5 mm to 4.0 mm.

  The polymer material constituting the surface layer is not particularly limited, but polyamide, polyurethane, polyvinylidene fluoride, tetrafluoroethylene copolymer, polyester, polyimide, silicone resin, acrylic resin, polyvinyl butyral, ethylene tetrafluoroethylene copolymer, and the like. Examples thereof include polymers, melamine resins, fluororubbers, epoxy resins, polycarbonates, polyvinyl alcohol, cellulose, polyvinylidene chloride, polyvinyl chloride, polyethylene, and ethylene vinyl acetate copolymers.

The above polymer materials may be used alone or in combination of two or more. The number average molecular weight of the polymer material is preferably in the range of 1,000 to 100,000, and more preferably in the range of 10,000 to 50,000.
The surface layer preferably contains the following two types of carbon black (a) and (b) as a conductive agent in the polymer material.
(A) Specific surface area: 400 m ² / g or less, DBP oil absorption: 120 ml / 100 g or less, pH: 4 or less (b) Specific surface area: 400 m ² / g or more, DBP oil absorption: 120 ml / 100 g or more, pH: 4 or less The amount of the conductive agent added is not particularly limited, but is preferably in the range of 1 part by mass to 50 parts by mass with respect to 100 parts by mass of the polymer material, and in the range of 5 parts by mass to 20 parts by mass. Is more desirable.
In addition, the conductive agent and various particles used in the conductive elastic layer may be mixed to form a composition. Examples of the particles include metal oxides such as silicon oxide, aluminum oxide, and barium titanate, and composite metal oxides, and polymer powders such as tetrafluoroethylene and vinylidene fluoride. It is not limited to.
Here, the DBP oil absorption is the DBP oil absorption defined in ASTM D2414-6TT.

  The thickness of the surface layer is not particularly limited, but is preferably 3 μm or more and 30 μm or less, and more preferably 5 μm or more and 14 μm or less.

  As the exposure unit 7, an optical device that can expose a light source such as a semiconductor laser, an LED (light emitting diode), a liquid crystal shutter, or the like on the surface of the electrophotographic photosensitive member can be used. The exposure unit 7 can use a known exposure means, but a laser optical system is particularly desirable. The laser serving as the light source is preferably a semiconductor laser having an oscillation wavelength of 780 nm, which can obtain a relatively large amount of laser light output and is available at a low cost.

As the developing device 64, a conventionally known developing device using a regular or reversal developer such as a one-component system or a two-component system can be used.
Although irregular toner can be used for the developing device, spherical toner is desirable from the viewpoint of high image quality. As a method for obtaining a spherical toner, a polymerizable monomer of a binder resin is emulsion-polymerized, and the formed dispersion is mixed with a dispersion of a colorant, a release agent, and, if necessary, a charge control agent. Then, an emulsion polymerization aggregation method for obtaining toner particles by agglomeration and heat fusion, or a solution of a polymerizable monomer and a colorant, a release agent, and a charge control agent as necessary to obtain a binder resin. Suspension polymerization method of polymerizing by suspending in aqueous solvent, dissolution suspension method of granulating by suspending solution of binder resin and colorant, mold release agent, charge control agent etc. in aqueous solvent if necessary Etc. can be used. In addition, a known method such as a production method in which the toner obtained by the above method is used as a core, and agglomerated particles are further adhered and heat-fused to have a core-shell structure can be used. From the viewpoint of shape control and particle size distribution control, a suspension polymerization method, an emulsion polymerization aggregation method, and a dissolution suspension method produced with an aqueous solvent are desirable, and an emulsion polymerization aggregation method is particularly desirable.

The volume average particle size of the spherical toner is preferably 2 μm or more and 12 μm or less, and more preferably 3 μm or more and 9 μm or less. The average shape factor SF1 is preferably in the range of 110 to 135. When the average shape factor SF1 is smaller than 110, the cleaning performance may be greatly deteriorated, and cleaning failure may occur easily. On the other hand, when the average shape factor SF1 is larger than 135, the transferability may be deteriorated, resulting in a decrease in image quality and an increase in waste toner that is not transferred.
The average shape factor SF1 of the toner is obtained by taking toner particles dispersed on a slide glass or an optical microscope image of the toner into a Luzex image analyzer (manufactured by Nireco) through a video camera and projecting the maximum length of 50 or more toners. The area is obtained, calculated by the following formula (1), and the average value is obtained.
SF1 = (ML ² / A) × (π / 4) × 100 (1)
In the formula (1), ML represents the maximum length of the toner particles, and A represents the projected area of the toner particles.
The volume average particle diameter of the toner can be obtained using, for example, Coulter Multisizer (manufactured by Coulter).

As a transfer means, in addition to a contact charging member such as a transfer roll 50, a contact transfer charger using a belt, a film, a rubber blade, or the like, a scorotron transfer charger using a corona discharge, a corotron transfer charger, etc. Can be mentioned.
When using a roll-shaped transfer means, the hardness is required to be moderate. Specifically, the Asker C hardness is preferably in the range of 20 to 50, and more preferably in the range of 25 to 40. The contact pressure to the electrophotographic photosensitive member 61 is preferably in the range of 10 gf / cm to 30 gf / cm, and more preferably in the range of 15 gf / cm to 25 gf / cm. If the hardness or the contact pressure is out of an appropriate range, an appropriate gap may not be obtained during transfer, uniform discharge may not be performed, and uniform transfer may not be performed.
As a method for transferring toner to a transfer material or an intermediate transfer member using the transfer roll 50, a constant current is applied to the transfer roll 50, and the applied current is preferably a direct current. The current range is desirably 10 μA or more and 50 μA or less, and more desirably 15 μA or more and 30 μA or less.

The cleaning device 62 is for removing residual toner adhering to the surface of the electrophotographic photosensitive member after the transfer process. The cleaned electrophotographic photosensitive member is repeatedly used for the above-described image forming process. . As the cleaning device, brush cleaning, roll cleaning, and the like can be used in addition to the cleaning blade. Among these, the cleaning blade is used, and the edge of one end thereof is brought into contact with the surface of the electrophotographic photosensitive member and adhered to the surface. A method of removing a developer such as toner is desirable.
Examples of the material for the cleaning blade include urethane rubber, neoprene rubber, and silicone rubber.

  Since the image forming apparatus according to the present embodiment includes the static elimination lamp 7a, a phenomenon in which the residual potential of the electrophotographic photosensitive member is brought into the next cycle when the electrophotographic photosensitive member is repeatedly used is prevented. Therefore, the image quality can be further improved. Note that the image forming apparatus according to the present embodiment only needs to include the static elimination lamp 7a as necessary.

Next, a preferred embodiment of the electrophotographic photoreceptor 61 will be described.
FIG. 2 is a schematic view showing a cross section of the electrophotographic photoreceptor 61. In FIG. 2, an intermediate layer 22 is provided on a conductive support 21, a charge generation layer 23 and a charge transport layer 24 are provided thereon, and a protective layer 25 is provided on the photosensitive layer. Yes.

  As the conductive support 21, drum-shaped aluminum is used, but is not limited thereto. Moreover, you may perform an anodizing process, a boehmite process, a honing process, etc. for the purpose of injection | pouring prevention, adhesive improvement, and interference fringe prevention.

Materials used for the intermediate layer 22 include organic zirconium compounds, organic titanium compounds, and organic aluminum compounds, as well as other organic metal compounds, particularly organic zirconium compounds, organic titanyl compounds, and organic aluminum compounds, which have low residual potential and good electrophotographic characteristics. Is preferably used to indicate As the binder resin used for the intermediate layer, polyvinyl alcohol, polyvinyl methyl ether, poly-N-vinyl imidazole, polyethylene oxide, ethyl cellulose, methyl cellulose, ethylene-acrylic acid copolymer, polyamide, polyimide, casein, gelatin, polyethylene , Polyester, phenol resin, vinyl chloride-vinyl acetate copolymer, epoxy resin, polyvinyl pyrrolidone, polyvinyl pyridine, polyurethane, polyglutamic acid, polyacrylic acid and the like.
Further, an electron transporting pigment may be mixed / dispersed in the intermediate layer. Examples of the electron transport pigment include organic pigments such as perylene pigment, bisbenzimidazole perylene pigment, polycyclic quinone pigment, indigo pigment, and quinacridone pigment, and inorganic pigments such as zinc oxide and titanium oxide. Among these pigments, perylene pigments, bisbenzimidazole perylene pigments and polycyclic quinone pigments, zinc oxide, and titanium oxide are desirably used because of their high electron mobility. Further, the surface of these pigments may be surface-treated with the above-mentioned coupling agent or binder for the purpose of controlling dispersibility and charge transport property.

When the intermediate layer 22 is formed, a coating solution in which the above components are added to a solvent is used.
As the solvent used for forming the intermediate layer, known organic solvents, for example, aromatic hydrocarbon solvents such as toluene and chlorobenzene, aliphatics such as methanol, ethanol, n-propanol, iso-propanol, and n-butanol Alcohol solvents, ketone solvents such as acetone, cyclohexanone and 2-butanone, halogenated aliphatic hydrocarbon solvents such as methylene chloride, chloroform and ethylene chloride, cyclic or linear such as tetrahydrofuran, dioxane, ethylene glycol and diethyl ether Examples include ether solvents, ester solvents such as methyl acetate, ethyl acetate, and n-butyl acetate. These solvents may be used alone or in combination of two or more. When mixing, any solvent can be used as long as it can dissolve the binder resin as a mixed solvent.

  As the coating method for forming the intermediate layer, usual methods such as a dip coating method, a push-up coating method, a wire bar coating method, a spray coating method, a blade coating method, a knife coating method, and a curtain coating method are used.

  The film thickness of the intermediate layer 22 is set, for example, in the range of 0.1 μm to 3 μm.

  Next, the charge generation layer 23 will be described. The charge generation layer is composed of a charge generation material and a binder resin. The charge generation material is preferably a phthalocyanine-based material having photosensitivity in the infrared region and high sensitivity, and is preferably at least 7.5 at the Bragg angle (2θ ± 0.2) of the X-ray diffraction spectrum using Cukα rays. Bragg angle (2θ ±) of X-ray diffraction spectrum using hydroxygallium phthalocyanine having a diffraction peak at the positions of 9.9, 12.5, 16.3, 18.6, 25.1, 28.1, or Cukα rays 0.2), titanyl phthalocyanine having diffraction peaks at least at positions of 7.6, 18.3, 23.2, 24.2, 27.3 is desirable. The binder resin can be selected from a wide range of insulating resins and can also be selected from organic photoconductive polymers. For example, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer resin, vinylidene chloride-acrylonitrile copolymer resin, vinyl chloride-vinyl acetate-maleic anhydride Resins, silicone resins, silicon-alkyd resins, phenol-formaldehyde resins, styrene-alkyd resins, poly-N-vinylcarbazole and the like. The binder resins can be used alone or in combination of two or more.

  In forming the charge generation layer 23, a coating solution in which the above components are added to a solvent is used. Examples of such solvents include aromatic hydrocarbon solvents such as toluene and chlorobenzene, aliphatic alcohol solvents such as methanol, ethanol, n-propanol, iso-propanol, and n-butanol, acetone, cyclohexanone, and 2-butanone. Ketone solvents, halogenated aliphatic hydrocarbon solvents such as methylene chloride, chloroform, ethylene chloride, cyclic or linear ether solvents such as tetrahydrofuran, dioxane, ethylene glycol, diethyl ether, methyl acetate, ethyl acetate, n acetate -Organic solvents, such as ester solvents, such as butyl. These solvents are used alone or in combination of two or more. When mixing, any solvent may be used as long as the binder resin can be dissolved as a mixed solvent.

  In order to disperse the charge generation material in the resin, the coating liquid is subjected to a dispersion treatment. As a dispersion method, a media disperser such as a ball mill, a vibrating ball mill, an attritor, a sand mill, or a horizontal sand mill, or a medialess disperser such as an agitator, an ultrasonic disperser, a roll mill, or a high-pressure homogenizer is used. Further, examples of the high-pressure homogenizer include a collision method in which the dispersion liquid is dispersed by liquid-liquid collision or liquid-wall collision in a high pressure state, and a penetration method in which the fine liquid is penetrated and dispersed in a high pressure state.

  Examples of methods for applying the coating solution thus obtained onto the intermediate layer 22 include dip coating, push-up coating, wire bar coating, spray coating, blade coating, knife coating, and curtain coating. Can be mentioned. The film thickness of the charge generation layer 23 is desirably set in a range from 0.01 μm to 5 μm, more desirably from 0.05 μm to 2.0 μm.

  Next, the charge transport layer 24 will be described. The charge transport layer includes a charge transport material and a binder resin. A known charge transport material can be used as the charge transport material. Moreover, a charge transport agent may be used individually by 1 type, and may be used in combination of 2 or more type.

  Examples of the charge transport material include oxadiazole derivatives such as 2,5-bis (p-diethylaminophenyl) -1,3,4-oxadiazole, 1,3,5-triphenyl-pyrazoline, 1- [ Pyrazoline derivatives such as pyridyl- (2)]-3- (p-diethylaminostyryl) -5- (p-diethylaminostyryl) pyrazoline, triphenylamine, N, N′-bis (3,4-dimethylphenyl) biphenyl- Aromatic tertiary amino compounds such as 4-amine, tri (p-methylphenyl) aminyl-4-amine, dibenzylaniline, N, N′-bis (3-methylphenyl) -N, N′-diphenylbenzidine Aromatic tertiary diamino compounds such as 3- (4'-dimethylaminophenyl) -5,6-di- (4'-methoxyphenyl) -1,2,4 1,2,4-triazine derivatives such as triazine, hydrazone derivatives such as 4-diethylaminobenzaldehyde-1,1-diphenylhydrazone, quinazoline derivatives such as 2-phenyl-4-styryl-quinazoline, 6-hydroxy-2,3- Benzofuran derivatives such as di (p-methoxyphenyl) benzofuran, α-stilbene derivatives such as p- (2,2-diphenylvinyl) -N, N-diphenylaniline, enamine derivatives, carbazole derivatives such as N-ethylcarbazole, poly -Hole transport materials such as -N-vinylcarbazole and its derivatives, quinone compounds such as chloranil and broanthraquinone, tetraanoquinodimethane compounds, 2,4,7-trinitrofluorenone, 2,4,5,7 Fluoreno such as tetranitro-9-fluorenone And an electron transport material such as a thiophene compound, a xanthone compound, and a thiophene compound, and a polymer having a group consisting of the above-described compounds in the main chain or side chain. These charge transport materials can be used alone or in combination of two or more.

  The binder resin for the charge transport layer 24 is not particularly limited, but a known electrically insulating resin capable of forming a film is desirable. Of these, polycarbonate resins, polyester resins, methacrylic resins, and acrylic resins are desirable because they are excellent in compatibility with charge transport materials, solubility in solvents, and strength. These binder resins may be used individually by 1 type, and may be used in combination of 2 or more type.

  The charge transport layer 24 is formed using a coating solution in which the above components are added to a solvent. Solvents used for forming the charge transport layer include known organic solvents, for example, aromatic hydrocarbon solvents such as toluene and chlorobenzene, and fats such as methanol, ethanol, n-propanol, iso-propanol, and n-butanol. Aromatic alcohol solvents, ketone solvents such as acetone, cyclohexanone and 2-butanone, halogenated aliphatic hydrocarbon solvents such as methylene chloride, chloroform and ethylene chloride, cyclic or straight chain such as tetrahydrofuran, dioxane, ethylene glycol and diethyl ether And ether solvents such as methyl ether solvent, methyl acetate, ethyl acetate and n-butyl acetate. These solvents may be used alone or in combination of two or more. When mixing, any solvent may be used as long as the binder resin can be dissolved as a mixed solvent. The mixing ratio of the charge transport material and the binder resin is preferably 10: 1 to 1: 5.

  The charge transport layer forming coating solution thus obtained can be applied onto the charge generation layer 23 by dip coating, push-up coating, wire bar coating, spray coating, blade coating, knife coating. Ordinary methods such as curtain coating are used. The film thickness of the charge transport layer is desirably set in the range of 5 μm to 50 μm, more desirably 10 μm to 40 μm.

  Further, for the purpose of preventing deterioration of the electrophotographic photosensitive member due to ozone, oxidizing gas, or light / heat generated in the image forming apparatus, oxidation is prevented in the photosensitive layer (the charge generation layer 23, the charge transport layer 24, etc.). Additives such as an agent, a light stabilizer, and a heat stabilizer can be added.

  Next, the protective layer 25 will be described. The protective layer is the outermost surface layer in the electrophotographic photosensitive member 61 and is a layer provided to give resistance to abrasion, scratches, and the like on the outermost surface.

  Although the protective layer 25 should just be comprised including the crosslinked material using at least 1 type of the curable charge transport material shown by general formula (I), this crosslinked material is the following general formula (A). And a crosslinked product using at least one compound represented by the general formula (B) and at least one curable charge transporting material represented by the general formula (I).

[In Formula (A), R ₁₁ represents an alkyl group which may be branched having 1 to 10 carbon atoms, a substituted or unsubstituted phenyl group having 6 to 10 carbon atoms, or R _{12 to} R ₁₅ are Each independently represents a hydrogen atom, —CH ₂ —OH or —CH ₂ —O—R ₁₆ , and R ₁₆ represents a branched alkyl group having 1 to 5 carbon atoms. ]

[In Formula (B), R _{17 to} R ₂₂ each independently represent hydrogen, —CH ₂ —OH or —CH ₂ —O—R ₂₃ , and R ₂₃ represents a branched alkyl having 1 to 5 carbon atoms. Indicates a group. ]

  By including a cross-linked product obtained using such a compound in the protective layer of the electrophotographic photosensitive member, the electrophotographic characteristics, mechanical strength, electric resistance characteristics, etc. of the electrophotographic photosensitive member can be further enhanced.

  In the curable charge transporting material represented by the general formula (I), examples of F include an n2 valent organic group having an arylamine skeleton. Among n2-valent organic groups having an arylamine skeleton, n2-valent organic groups having a diphenylamine skeleton, n-valent organic groups having a triphenylamine skeleton, n-valent organic groups having a tetraphenylbenzidine skeleton, and the like are desirable. An n2-valent organic group having a triphenylamine skeleton is particularly desirable.

  In the curable charge transporting material represented by the general formula (I), R1 is preferably a linear or branched alkylene group having 1 to 3 carbon atoms.

In the curable charge transporting material represented by the general formula (I), R2 is preferably a linear or branched alkylene group having 1 to 3 carbon atoms.
As the curable charge transporting material represented by the general formula (I), in particular, F is an n2 valent organic group having a triphenylamine skeleton or an n2 valent organic group having a tetraphenylbenzidine skeleton, and n1 is A compound in which R 2 is a linear or branched alkylene group having 1 to 3 carbon atoms, n 2 is 2 to 4 and Y is —OH is desirable.

  Specific examples of the curable charge transporting material represented by the general formula (I) include the following compounds. In the following specific examples, Me represents a methyl group.

The content of the curable charge transporting material represented by the general formula (I) in the protective layer 25 is desirably 90% by mass or more and 99% by mass or less from the viewpoint of electrical characteristics and strength.
As the content of the compound represented by the general formula (A) or the general formula (B), from the viewpoint of electrical characteristics and strength, the compound represented by the general formula (A) and the compound represented by the general formula (B) The total content is preferably 0.1% by mass or more and 3% by mass or less.

  In addition, a coupling agent or a fluorine compound may be added to the protective layer 25 for the purpose of adjusting the film formability, flexibility, lubricity, and adhesiveness of the film. As such a compound, various silane coupling agents and commercially available silicone hard coat agents can be used.

  Further, a resin that dissolves in alcohol can be added for the purpose of mechanical strength, scratch resistance, particle dispersibility, viscosity control, torque reduction, wear amount control, pot life extension, and the like of the protective layer 25. Specific examples of the resin soluble in alcohol include, for example, methoxymethylated nylon which is alcohol-soluble nylon, butyral resin, and the like.

  Further, a curing catalyst can be used to accelerate the curing of the protective layer 25. An acid-based catalyst can be desirably used as the curing catalyst. Acid-based catalysts include acetic acid, chloroacetic acid, trichloroacetic acid, trifluoroacetic acid, oxalic acid, maleic acid, malonic acid, lactic acid and other aliphatic carboxylic acids, benzoic acid, phthalic acid, terephthalic acid, trimellitic acid, etc. Aromatic carboxylic acids, methane sulfonic acids, dodecyl sulfonic acids, benzene sulfonic acids, aliphatics such as dodecyl benzene sulfonic acids, naphthalene sulfonic acids, and aromatic sulfonic acids are used, but sulfur-containing materials should be used. desirable. The blending amount of the curing catalyst is preferably 0.01% by mass or more and 5% by mass or less with respect to the total solid content of the protective layer 25, and particularly 0.02% by mass or more and 1% by mass or less is suitable. When the blending amount of the curing catalyst exceeds 5%, the resistance of the protective layer is lowered due to the residual catalyst, and an image may be easily generated under high temperature and high humidity. May be lower.

  The protective layer 25 includes a curable charge transporting material represented by the general formula (I), and, if necessary, at least one compound represented by the general formula (A) and the general formula (B). Applying a coating material containing a coupling agent, a fluorine compound and a resin that dissolves in an alcohol, and an organic solvent that can dissolve the curable charge transporting material represented by the general formula (I) as a solvent, and heating. May be formed.

  Examples of the solvent used for forming the protective layer include known organic solvents such as aromatic hydrocarbon solvents such as toluene and chlorobenzene, methanol, ethanol, n-propanol, iso-propanol, n-butanol, and t-butanol. Aliphatic alcohol solvents such as acetone, ketone solvents such as acetone, cyclohexanone and 2-butanone, halogenated aliphatic hydrocarbon solvents such as methylene chloride, chloroform and ethylene chloride, cyclic such as tetrahydrofuran, dioxane, ethylene glycol and diethyl ether Or ester solvents, such as a linear ether solvent, methyl acetate, ethyl acetate, and n-butyl acetate, are mentioned. These solvents may be used alone or in combination of two or more.

  As a coating method for forming the protective layer, usual methods such as a dip coating method, a push-up coating method, a wire bar coating method, a spray coating method, a blade coating method, a knife coating method, a curtain coating method, and an inkjet method are used. The thickness of the protective layer is desirably set in the range of 2 μm to 15 μm, more desirably 4 μm to 8 μm.

  The moisture content measured by thermal analysis of the protective layer 25 is 0.3% by mass or more and 0.5% by mass or less. As a method for adjusting the moisture content, (1) In the coating for forming the protective layer A method of adding water and applying a protective layer; (2) a method of heating the surface layer at a drying temperature lower than 145 ° C. when heating after applying the coating for forming the protective layer; and (3) protection. After the coating material for layer formation is left in a high humidity environment (specifically, for example, 80% RH or more and 85% RH or less) (specifically, for example, 2 hours or more and 4 hours or less), the protective layer is then applied. The method of apply | coating etc. are mentioned.

  The electrophotographic photosensitive member used in the present embodiment has a substrate and a plurality of layers formed on the substrate, and the outermost surface layer of the plurality of layers is cured represented by the general formula (I). A water content measured by thermal analysis of the outermost surface layer is not less than 0.3% by mass and not more than 0.5% by mass. For example, the layer configuration is not particularly limited. In this embodiment, the photosensitive layer is a function-separated type photosensitive layer including a charge transport layer and a charge generation layer, and the photosensitive layer has a function-integrated type having both charge transport capability and charge generation capability. It may be a photosensitive layer.

  In the electrophotographic photoreceptor according to the exemplary embodiment, when the function-integrated photosensitive layer is the outermost surface layer, the function-integrated photosensitive layer is a curable charge transport property represented by the general formula (I). It is comprised including the crosslinked material which used at least 1 type of material, and the moisture content measured by the thermal analysis of the said outermost surface layer shall be 0.3 mass% or more and 0.5 mass% or less. When any one of the functional separation type photosensitive layers including the charge transport layer and the charge generation layer is the outermost surface layer, the layer corresponding to the outermost surface layer is represented by the general formula (I). A water content measured by thermal analysis of the outermost surface layer is configured to include 0.3% by mass or more and 0.5% by mass or less, including a cross-linked product using at least one kind of curable charge transporting material. Is done. Further, when a protective layer is provided on the photosensitive layer as the outermost surface layer, the protective layer contains a cross-linked product using at least one curable charge transporting material represented by the general formula (I). It is comprised and the moisture content measured by the thermal analysis of the said outermost surface layer shall be 0.3 to 0.5 mass%.

FIG. 3 is an overall configuration diagram illustrating a second example of the image forming apparatus according to the present embodiment.
The image forming apparatus 1000 ′ of this embodiment is a color printer.

  The image forming apparatus 1000 'includes image holding members 61K, 61C, 61M, and 61Y that are electrophotographic photosensitive members that rotate in the directions of arrows Bk, Bc, Bm, and By in the drawing, respectively.

  Further, around each image carrier, charging members 65K, 65C, 65M, and 65Y that are charging means for charging the surface of the image carrier by rotating while in contact with each image carrier, and each charged image carrier Exposure units 7K and 7C, which are electrostatic latent image forming means for forming an electrostatic latent image for each color of black (K), cyan (C), magenta (M), and yellow (Y) by irradiation with laser light. , 7M, 7Y, and developing units 64K, 64C, 64M, and 64Y, which are image forming units that develop the electrostatic latent images on the image carriers with a developer containing toner of each color to form toner images of each color. It has been.

  In the image forming apparatus 1000 ′, among the above-described components, the black charging member 65K, the image holding member 61K, the cleaning device 62K, and the developing device 64K are integrated with the components of the process cartridge 100K. Similarly, a charging member 65C, an image holding member 61C, a cleaning device 62C, and a developing device 64C for cyan, a charging member 65M, an image holding member 61M, a cleaning device 62M, and a developing device 64M for magenta. And the charging member 65Y, the image holding member 61Y, the cleaning device 62Y, and the developing device 64Y for yellow are integrated into the components of the process cartridges 100C, 100M, and 100Y. By incorporating these four process cartridges into the image forming apparatus 1000 ′, the image forming apparatus 1000 ′ is provided with each part that is a component of these process cartridges. Each of these process cartridges 100K, 100C, 100M, and 100Y corresponds to an example of the process cartridge of the present embodiment.

  The image forming apparatus 1000 ′ also includes an intermediate transfer belt 5 that is an intermediate transfer body that receives a transfer (primary transfer) of each color toner image formed on each image carrier and conveys a primary transfer image. The primary transfer rolls 50K, 50C, 50M, and 50Y for primary transfer of the toner images of the respective colors to the intermediate transfer belt 5, the secondary transfer roll pair 9 for secondary transfer to the paper, and 2 on the paper Fixing device 10 ′, which is a fixing means for fixing the next transferred toner image, supplies toner of each color component to four developing devices, and stores four toner cartridges 4 K, 4 C, 4 M, 4 Y, and paper. A sheet storage member 1 'is also provided.

  The transfer target according to the present embodiment is not particularly limited as long as it is a medium that transfers a toner image formed on an electrophotographic photosensitive member. For example, when transferring directly from an electrophotographic photosensitive member to a transfer medium such as paper, paper or the like is the transfer medium. When an intermediate transfer member is used, the intermediate transfer member is a transfer target.

  Here, the intermediate transfer belt 5 circulates and moves in the direction of arrow A in the figure while being stretched between the secondary transfer roll 9b and the drive roll 5a while receiving the drive force from the drive roll 5a.

  In the above description, the case where the intermediate transfer belt 5 is used as the intermediate transfer member has been described. However, the intermediate transfer member may have a belt shape like the intermediate transfer belt 5 or a drum shape. Also good. In the case of a belt shape, a conventionally known resin can be used as the resin material used as the base material of the intermediate transfer member. For example, polyimide resin, polycarbonate resin (PC), polyvinylidene fluoride (PVDF), polyalkylene terephthalate (PAT), ethylenetetrafluoroethylene copolymer (ETFE) / PC, ETFE / PAT, PC / PAT blend material, polyester Resin materials such as polyether ether ketone and polyamide, and resin materials using these as main raw materials. Furthermore, a resin material and an elastic material can be blended and used. Among these, an intermediate transfer belt using a polyimide resin is desirable from the viewpoint of mechanical strength.

Next, an image forming operation in the image forming apparatus 1000 ′ will be described.
The four image holders 61K, 61C, 61M, and 61Y are charged by charging members 65K, 65C, 65M, and 65Y, respectively, and receive the laser beams emitted from the exposure units 7K, 7C, 7M, and 7Y to hold the images. An electrostatic latent image is formed on the body. The formed electrostatic latent image is developed with a developer containing toner of each color by the developing devices 64K, 64C, 64M, and 64Y to form a toner image. The toner images of the respective colors formed in this way are yellow (Y), magenta (M), cyan (C) on the intermediate transfer belt 5 in the primary transfer rolls 50K, 50C, 50M, and 50Y corresponding to the respective colors. ) And black (K) are sequentially transferred (primary transfer) and superposed to form a multicolor primary transfer image.

The multicolor primary transfer image is conveyed to the secondary transfer roll pair 9 by the intermediate transfer belt 5. On the other hand, in response to the formation of the multi-color primary transfer image, the sheet is taken out from the sheet accumulating member 1 ′ and conveyed by the conveying roll 3, and the position is adjusted by the alignment roll pair 8. Then, the multi-color primary transfer image is transferred (secondary transfer) to the conveyed paper by the secondary transfer roll pair 9, and further fixed to the secondary transfer image on the paper by the fixing device 10 ′. Processing is performed. After the fixing process, the sheet having the fixed image passes through the delivery roll pair 13 and is discharged to the paper discharge receiver 2.
The above is the description of the image forming operation in the image forming apparatus 1000 ′.

  The process cartridge according to the present embodiment has a substrate and a plurality of layers formed on the substrate, and the outermost surface layer of the plurality of layers has a curable charge transport property represented by the general formula (I). An electrophotographic photoreceptor comprising a cross-linked product using at least one kind of material, and having a water content measured by thermal analysis of the outermost surface layer of 0.3% by mass or more and 0.5% by mass or less; A charging roll that contacts the electrophotographic photosensitive member, and a charging unit that charges the electrophotographic photosensitive member, and has only to be removable from the main body of the image forming apparatus. The image forming apparatus further includes developing means for developing the electrostatic latent image formed on the electrophotographic photosensitive member with toner to form a toner image, toner removing means for removing the toner remaining on the electrophotographic photosensitive member, and the like. May be.

  Hereinafter, the present embodiment will be described more specifically based on examples and comparative examples, but the present embodiment is not limited to the following examples.

Example 1
-Intermediate layer-
Zinc oxide: (average particle size 70 nm: manufactured by Teica Co., Ltd .: specific surface area value 15 m ² / g) 100 parts by mass is stirred and mixed with 500 parts by mass of toluene, and a silane coupling agent (KBM603: manufactured by Shin-Etsu Chemical Co., Ltd.) 1.5 parts by mass. Part was added and stirred for 2 hours. Thereafter, toluene was distilled off under reduced pressure and baked at 150 ° C. for 2 hours to obtain a silane coupling agent surface-treated zinc oxide pigment.
100 parts by mass of the surface-treated zinc oxide was stirred and mixed with 500 parts by mass of tetrahydrofuran, a solution prepared by dissolving 1 part by mass of alizarin in 50 parts by mass of tetrahydrofuran was added, and the mixture was stirred at 50 ° C. for 5 hours. Thereafter, zinc oxide to which alizarin was imparted by filtration under reduced pressure was filtered off, and further dried at 60 ° C. under reduced pressure to obtain an alizarin-given zinc oxide pigment.
60 parts by mass of this alizarin-added zinc oxide pigment and a curing agent (blocked isocyanate Sumijour 3175: manufactured by Sumitomo Bayern Urethane Co., Ltd.): 15 parts by mass and butyral resin BM-1 (manufactured by Sekisui Chemical) 85 parts by mass of methyl ethyl ketone 38 parts by mass of the solution dissolved in 1 and 25 parts by mass of methyl ethyl ketone were mixed and dispersed for 2 hours with a sand mill using 1 mmφ glass beads to obtain a dispersion.
As a catalyst, 0.005 part by mass of dioctyltin dilaurate was added to the resulting dispersion to obtain an intermediate layer coating solution. This coating solution was applied on an aluminum substrate having a diameter of 84 mm, a length of 340 mm, and a thickness of 1 mm by a dip coating method, followed by drying and curing at 160 ° C. for 100 minutes to obtain an intermediate layer having a thickness of 20 μm.

-Charge generation layer-
Next, a mixture of 15 parts by mass of hydroxygallium phthalocyanine, 10 parts by mass of vinyl chloride-vinyl acetate copolymer resin (VMCH, manufactured by Nippon Union Carbide) and 300 parts by mass of n-butyl alcohol was used as a charge generating material. For 4 hours. The obtained dispersion was applied by dip coating on the intermediate layer and dried by heating at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.2 μm.

-Charge transport layer-
Next, 42 parts by mass of N, N′-bis (3-methylphenyl) -N, N′-diphenylbenzidine and 58 parts by mass of bisphenol Z polycarbonate resin (TS2050: viscosity average molecular weight 50,000: manufactured by Teijin Chemicals Ltd.) A coating solution prepared by dissolving and mixing 280 parts by mass of Tetrohydrofuran and 120 parts by mass of toluene is dip-coated on an aluminum support coated up to the charge generation layer, and dried at 135 ° C. for 40 minutes to obtain a film thickness of 19 μm. A charge transport layer was formed.

−Protective layer (surface layer) −
Next, as a protective layer, 50 parts by mass of the compound represented by Compound Example I-11, 50 parts by mass of the compound represented by Compound Example I-16, and 1 part by mass of melamine having the structure shown below were mixed with 200 parts by mass of t-butanol. Dissolved in. And 15 mass% of water was added, and the coating liquid for protective layers was obtained. The obtained coating solution was dip coated on an aluminum support coated up to the charge transport layer and dried at 150 ° C. for 40 minutes to form a protective layer having a thickness of 5 μm.

  After preparation of the photoreceptor, the moisture content of the outermost surface layer (protective layer) of the photoreceptor was measured using a TG / DTA apparatus manufactured by SII Nanotechnology. At the same time as the production of the photoreceptor, the film was peeled off from the single layer of the outermost surface layer produced for measuring the moisture content, and 10 mg was weighed and the moisture content was measured.

  Using a modified machine in which the obtained photoreceptor is mounted on Docu Center IV C5570 manufactured by Fuji Xerox Co., Ltd., an image of 30% image density was formed on A3 paper under the conditions of 25 ° C./50% RH, and image flow (image quality) Evaluation) was visually confirmed and evaluated based on the following criteria. The results are shown in Table 1.

○: No image flow.
Δ: There is a slight image flow.
X: Image flow is particularly bad.

The modified Docu Center IV C5570 is further modified to have the following charging roll as charging means.
[Production of charging device (charging roll)]
(Preparation of conductive elastic roll A)
Epichlorohydrin rubber (Gechron 3106; Nippon Zeon) 95.6 parts by mass, nitrile butadiene rubber (N250S; JSR) 4.4 parts by mass, benzyltriethylammonium chloride (Kanto Chemical) 0.9 parts by mass, carbon black (Ketjen Black EC; Lion) 15 parts by mass, sulfur (Sulfax PS; Tsurumi Chemical Industries) 0.5 part by mass, tetramethyllithium disulfide (Noxeller TT; Ouchi Shinsei Chemical Industry) 1.5 parts by mass, dibenzothiazol disulfide (Noxeller DM; Opened a mixture of 1.5 parts by weight of Ouchi Shinsei Chemical Industry, 20 parts by weight of calcium carbonate (Silver W; Shiroishi Industry), 1 part by weight of stearic acid (Kanto Chemical) and 5 parts by weight of zinc oxide (Shodo Chemical Industry). Conductivity of 8mm in diameter made of SUS303 by kneading with a roll The bearing member surface via the adhesive layer to form a roll having a diameter of 12.5mm with a press molding machine. Thereafter, a conductive elastic roll A having a diameter of 12 mm and a film thickness of 3 mm was obtained by polishing.
(Preparation of charging roll 1)
F30K (N-methoxymethylated nylon): 100 parts by mass Polyvinyl butyral resin: 10 parts by mass Carbon black: 17 parts by mass Polyamide resin particles 1 (2001 UDNAT1; Arkema: porous filler): 33 parts by mass Acid Catalyst (Nacure 4167; King Industry): 4.4 parts by mass The dispersion obtained by diluting 15 parts by mass of the above mixture with 85 parts by mass of methanol and dispersing in a bead mill is immersed in the surface of the conductive elastic roll A. After the coating, heating was performed at 140 ° C. for 30 minutes to crosslink and dry to form an outermost surface layer having a thickness of 10 μm, whereby the charging roll 1 was obtained.
The surface roughness Rz of the obtained charging roll 1 was measured and found to be 9 μm.

(Example 2)
The intermediate layer, charge generation layer, and charge transport layer were prepared in the same manner as in Example 1.
Next, as a protective layer, 50 parts by mass of the compound represented by Compound Example I-11, 50 parts by mass of the compound represented by Compound Example I-16, and 1 part by mass of melamine used in Example 1 were added to t-butanol 200. Dissolved in parts by mass. And 20 mass% of water was added, and the coating liquid for protective layers was obtained. The obtained coating solution was dip coated on an aluminum support coated up to the charge transport layer and dried at 150 ° C. for 40 minutes to form a protective layer having a thickness of 5 μm.
Evaluation was carried out in the same manner as in Example 1. The obtained results are shown in Table 1.

(Example 3)
The intermediate layer, charge generation layer, and charge transport layer were prepared in the same manner as in Example 1.
Next, as a protective layer, 50 parts by mass of the compound represented by Compound Example I-11, 50 parts by mass of the compound represented by Compound Example I-16, and 1 part by mass of melamine used in Example 1 were added to t-butanol 200. A coating solution for the protective layer was obtained by dissolving in mass parts. The obtained coating solution was dip-coated on an aluminum support coated up to the charge transport layer, and dried at 140 ° C. for 40 minutes to form a protective layer having a thickness of 5 μm.
Evaluation was carried out in the same manner as in Example 1. The obtained results are shown in Table 1.

Example 4
The intermediate layer, charge generation layer, and charge transport layer were prepared in the same manner as in Example 1.
Next, as a protective layer, 50 parts by mass of the compound represented by Compound Example I-11, 50 parts by mass of the compound represented by Compound Example I-16, and 1 part by mass of melamine used in Example 1 were added to t-butanol 200. A solution was obtained by dissolving in parts by mass. This solution was stored in an environment with a humidity of 80% for 2 hours to obtain a coating solution for a protective layer. The obtained coating solution was dip coated on an aluminum support coated up to the charge transport layer and dried at 150 ° C. for 40 minutes to form a protective layer having a thickness of 5 μm.
Evaluation was carried out in the same manner as in Example 1. The obtained results are shown in Table 1.

(Comparative Example 1)
The intermediate layer, charge generation layer, and charge transport layer were prepared in the same manner as in Example 1.
Next, as a protective layer, 50 parts by mass of the compound represented by Compound Example I-11, 50 parts by mass of the compound represented by Compound Example I-16, and 1 part by mass of melamine used in Example 1 were added to t-butanol 200. A coating solution for the protective layer was obtained by dissolving in mass parts. The obtained coating solution was dip-coated on an aluminum support coated up to the charge transport layer and dried at 145 ° C. for 40 minutes to form a protective layer having a thickness of 5 μm.
Evaluation was carried out in the same manner as in Example 1. The obtained results are shown in Table 1.

(Comparative Example 2)
The intermediate layer, charge generation layer, and charge transport layer were prepared in the same manner as in Example 1.
Next, as a protective layer, 50 parts by mass of the compound represented by Compound Example I-11, 50 parts by mass of the compound represented by Compound Example I-16, and 1 part by mass of melamine used in Example 1 were added to t-butanol 200. A coating solution for the protective layer was obtained by dissolving in mass parts. The obtained coating solution was dip coated on an aluminum support coated up to the charge transport layer and dried at 150 ° C. for 40 minutes to form a protective layer having a thickness of 5 μm.
Evaluation was carried out in the same manner as in Example 1. The obtained results are shown in Table 1.

(Comparative Example 3)
The intermediate layer, charge generation layer, and charge transport layer were prepared in the same manner as in Example 1.
Next, as a protective layer, 50 parts by mass of the compound represented by Compound Example I-11, 50 parts by mass of the compound represented by Compound Example I-16, and 1 part by mass of melamine used in Example 1 were added to t-butanol 200. Dissolved in parts by mass. And 25 mass% of water was added and the coating liquid for protective layers was obtained. The obtained coating solution was dip coated on an aluminum support coated up to the charge transport layer and dried at 150 ° C. for 40 minutes to form a protective layer having a thickness of 5 μm.
Evaluation was carried out in the same manner as in Example 1. The obtained results are shown in Table 1.

DESCRIPTION OF SYMBOLS 1 Sheet storage member, 2 Paper discharge receptacle, 3 Conveyance roll, 5 Intermediate transfer belt, 7a Static elimination lamp, 7 Exposure part, 8 Registration roll pair, 9th transfer roll pair, 10 Fixing device, 13 Sending roll pair, 21 Conductive support , 22 intermediate layer, 23 charge generation layer, 24 charge transport layer, 25 protective layer, 50 transfer roll, 61 electrophotographic photosensitive member, 62 cleaning device, 64 developer, 65 charging member, 65a power supply, 100 process cartridge, 100a Support member, 1000, 1000 ′ image forming apparatus

Claims (3)

Crosslinking using a substrate and a plurality of layers formed on the substrate, wherein the outermost surface layer of the plurality of layers uses at least one curable charge transporting material represented by the following general formula (I) And an electrophotographic photoreceptor having a water content measured by thermal analysis of the outermost surface layer of 0.3% by mass or more and 0.5% by mass or less,
A charging roll for contacting the electrophotographic photosensitive member, and charging means for charging the electrophotographic photosensitive member;
Electrostatic latent image forming means for forming an electrostatic latent image on the charged electrophotographic photosensitive member;
Developing means for developing the electrostatic latent image formed on the electrophotographic photosensitive member with toner to form a toner image;
Transfer means for transferring the toner image formed on the electrophotographic photosensitive member to a transfer target;
An image forming apparatus comprising: a toner removing unit configured to remove toner remaining on the electrophotographic photosensitive member.
F-((-R1-X) _n1R2 -Y) _n2 general formula (I)
(In general formula (I), F represents an organic group derived from a compound having a hole transporting ability, and R1 and R2 each independently represents a linear or branched alkylene group having 1 to 5 carbon atoms. N1 is 0 or 1, and n2 is an integer of 1 to 4. X represents any one selected from an oxygen atom, NH, and a sulfur atom, and Y represents —OH, —OCH ₃ , — NH _2, shows one group selected -SH, and from -COOH.)   The image forming apparatus according to claim 1, wherein a content of the charge transporting material in the outermost surface layer is 90% by mass or more and 99% by mass or less. Crosslinking using a substrate and a plurality of layers formed on the substrate, wherein the outermost surface layer of the plurality of layers uses at least one curable charge transporting material represented by the following general formula (I) And an electrophotographic photoreceptor having a water content measured by thermal analysis of the outermost surface layer of 0.3% by mass or more and 0.5% by mass or less,
A process cartridge comprising a charging roll that contacts the electrophotographic photosensitive member, and charging means for charging the electrophotographic photosensitive member.
F-((-R1-X) _n1R2 -Y) _n2 general formula (I)
(In general formula (I), F represents an organic group derived from a compound having a hole transporting ability, and R1 and R2 each independently represents a linear or branched alkylene group having 1 to 5 carbon atoms. N1 is 0 or 1, and n2 is an integer of 1 to 4. X represents any one selected from an oxygen atom, NH, and a sulfur atom, and Y represents —OH, —OCH ₃ , — NH _2, shows one group selected -SH, and from -COOH.)