JP2019152749A - Image forming apparatus and image forming method - Google Patents

Abstract

To provide an image forming apparatus that solves the trade-off between wear resistance of a photoconductor and image blur and allows print output with high image uniformity even when the apparatus performs a large amount of printing in an electrophotographic process.SOLUTION: An image forming apparatus comprises a photoconductor and means for supplying lubricant to the photoconductor. The photoconductor has a surface Vickers hardness of 31 Hv(2.45/5) or more and 870 Hv(2.45/5), and the surface free energy of the photoconductor and the surface free energy of the lubricant are 20 mJ/mor more and 78 mJ/mor less.SELECTED DRAWING: None

Description

  The present invention relates to an image forming apparatus and an image forming method.

  Conventionally, most documents have been printed with electronic photographs used in copiers and used in various scenes. However, in recent years, the opportunity to make copies in the office has been decreasing year by year, taking advantage of paperless and cost-saving efforts. As electrophotography is ending its role so far, the expansion of applications from office printing to commercial printing is being sought. Since electrophotography does not require a plate-making process such as offset printing, there is an advantage that on-demand printing can be performed such that a large variety of originals are printed in a very small lot. However, in reality, the quality and homogeneity of the printed matter are much inferior to those of offset printing.

  In commercial printing, if the image quality of the printed matter is not uniform, it will not become a product. For this reason, in order to use electrophotography as commercial printing, homogenization of image quality is particularly important. In addition, since productivity and profitability are more important than office use, it is necessary to suppress the frequency of replacement of the photoconductor. Currently, the replacement life of a photoreceptor used in a high-end class electrophotographic apparatus is often set to about 1 million sheets. Even so, the durability as commercial printing is not sufficient. It is taught that the performance of electrophotography is still inadequate because no copier has been replaced by an offset press so far.

  The lifetime of the photoreceptor is determined from the trade-off relationship between wear resistance and suppression of image blur. When the photoreceptor is regarded as a kind of capacitor, it is understood that the electrostatic capacity increases and the chargeability deteriorates as the wear of the photoreceptor progresses. As a result, the printed image is likely to be fogged. In addition, as the electric field received by the photosensitive layer is increased, the charge blocking property is lowered, and scumming is liable to occur. Although it is important to increase the wear resistance of the photoconductor in order to delay the deterioration of the chargeability, since the wear on the photoconductor surface is delayed when the wear resistance is increased, the surface contamination accumulates without being refreshed. It becomes easy. The soiled photoreceptor surface tends to have a low surface resistance, and the electrostatic latent image may flow laterally and blur the image on a wet day. Due to such a trade-off relationship, the lifetime of the photoreceptor has reached its peak. For this reason, it can be said that the expansion of the use of electrophotography has also been limited.

  Further, Patent Document 1 includes a conductive support and a photosensitive layer provided on the conductive support. The hardness of the photosensitive layer is 20 or more in terms of Vickers hardness (Hv), and the photosensitive An electrophotographic photosensitive member having a surface free energy (γ) of 28 mN / m or more and 35 mN / m or less is disclosed. This electrophotographic photosensitive member is described as having excellent wear resistance and a long durability life, and it is difficult for foreign matter to adhere to the surface, and it is easy to remove the foreign matter from the surface, and is excellent in cleaning performance.

However, just specifying the Vickers hardness and surface free energy of the photoconductor cannot achieve both durability and image blur resistance when a lubricant is applied.
The present invention eliminates the trade-off between photoconductor abrasion resistance and image blurring, and is excellent in durability even when using a lubricant. An object of the present invention is to provide an image forming apparatus that can perform the above-described process.

According to the present invention, there is provided the following image forming apparatus [1].
[1] It has a photoconductor and means for supplying a lubricant to the photoconductor, and the photoconductor has a surface Vickers hardness of 31 Hv (2.45 / 5) or more and 870 Hv (2.45 / 5). ) or less, and the and the image forming apparatus surface free energy of the surface free energy and lubricants of the photoconductor is 20 mJ / m ² or more 78mJ / m ² or less.

  According to the present invention, it is possible to dramatically improve the durability of a photoconductor, to suppress background stains and image blur, and to provide an image forming apparatus that can be sufficiently adapted to commercial printing. In addition, the printing cost can be reduced.

It is explanatory drawing of the surface free energy of a photoconductor, and the surface free energy of a lubricant. It is explanatory drawing of the surface free energy of a lubricant, and the surface free energy of the photoconductor after use. It is a schematic block diagram of an example of the aerosol deposition apparatus which forms the protective layer of a ceramic. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus of the present invention. It is a schematic block diagram which shows another example of the image forming apparatus of this invention. It is a schematic block diagram which shows an example of a process cartridge. It is a schematic block diagram which shows another example of the image forming apparatus of this invention. It is a schematic block diagram which shows another example of the image forming apparatus of this invention. It is a schematic block diagram which shows another example of the image forming apparatus of this invention. It is a schematic block diagram which shows an example of a lubricant supply means. It is a schematic block diagram which shows an example of the vacuum chamber of the apparatus for forming the protective layer which has a diamond-like carbon structure using plasma CVD method. It is a schematic block diagram which shows an example of the reaction tank provided in the vacuum tank shown in FIG. It is a schematic block diagram which shows an example of the reaction tank provided in the vacuum tank shown in FIG.

  The present inventor has found that a photoconductor having a predetermined surface free energy and a predetermined hardness is effective for suppressing wear and image blurring, and that the surface freeness of the lubricant is reduced. It has been found that the durability within the offset printing press can be obtained when the energy is in a specific range, and the present invention has been completed.

The present invention will be described in detail below.
The embodiment [1] of the present invention includes the following [2] to [5], and these will be described together.
[2] The image forming apparatus according to [1], wherein the photoconductor has a Vickers hardness of 36 Hv (2.45 / 5) or more and 870 Hv (2.45 / 5) or less.
[3] The photoconductor has a surface layer, and the surface layer is (1) fluororesin particles and curable resin, or fluororesin particles, metal oxide particles and curable resin, (2) DLC, ( 3) The image forming apparatus according to [1] or [2], which is any one of ceramics.
[4] The image forming apparatus according to any one of [1] to [3], wherein a surface free energy of the lubricant is 28 mJ / m ² or more and 42 mJ / m ² or less.
[5] A step of supplying a lubricant to the photoconductor, wherein the photoconductor has a surface Vickers hardness of 31 Hv (2.45 / 5) or more and 870 Hv (2.45 / 5) or less, and the surface free energy of the photoconductive material is at 20 mJ / m ² or more 78mJ / m ² or less, supplying the lubricant, and the surface free energy of the lubricant 20 mJ / m ² or more 78mJ / m ² or less An image forming method which is a step of applying a lubricant so as to become.

In an image forming apparatus to which a lubricant is applied, the balance between supply and removal of the lubricant is important for suppressing wear and image blur. Regarding wear, the photoconductor is subject to uneven wear according to uneven application of the lubricant. Since image defects such as soiling occur at the site where uneven wear progresses, the life of the photoconductor is determined at the local area where the wear rate is the highest, causing uneven wear. Regarding image blurring, once the lubricant supplied to the photoconductor surface is not removed and stays on the photoconductor surface indefinitely, the lubricant causes alteration such as molecular breakage on the photoconductor. The altered lubricant increases the surface free energy and tends to adsorb discharge products and moisture, causing image blurring. The image blur that occurs locally also determines the photoconductor lifetime. That is, when outputting a print image that requires homogeneity, it is important to improve the performance locally weaker than the average performance in order to increase the life of the photoconductor.
It is possible to suppress uneven wear by increasing the surface hardness of the photoconductor against wear. If the wear rate can be reduced to such an extent that uneven wear is substantially negligible, the problem is eliminated. It is important that the Vickers hardness of the photoconductor is 31 Hv (2.45 / 5) or more and 870 Hv (2.45 / 5) or less.

Next, countermeasures against image blur will be described. A cleaning blade is usually used to remove the lubricant transferred to the surface of the photoconductor. It is difficult to remove the lubricant by simply rubbing the surface of the photoconductor with a cleaning blade. In order to remove the lubricant transferred to the photoconductor surface, it is reasonable to use a mechanism that erases graphite marks written with a pencil with an eraser. Although it is conceivable that the cleaning blade itself has the same function as the eraser, the method of transferring the lubricant to the toner and removing the lubricant together with the toner does not require complicated apparatuses and processes. In order to make the lubricant easy to transfer to the toner, the surface free energy of the photoconductor may be lowered.
However, if the surface free energy of the photoconductor is too low, the lubricant will be difficult to wet the photoconductor, and if the lubricant is difficult to wet the photoconductor, it will contribute to uneven supply and consumption of the lubricant. Free energy has an advantageous range. The surface free energy of the photoconductor from the test of the inventors 20 mJ / m ² or more 78mJ / m ² or less is good in use and initial photoconductor.
In addition, by increasing the wear resistance of the photoconductor, it is possible to afford to increase the shearing force of the cleaning blade used as a cleaning means in the image forming apparatus. The level of preventing blur can be increased.

In the electrophotographic process, the lubricant staying on the surface of the photoconductor undergoes a charging step, whereby the surface free energy rises linearly with respect to the charging time. Since the inventor of the present invention increases the adhesion between the photoconductor and the lubricant according to the magnitude of the surface free energy of both, it is important that the surface free energy of the lubricant as well as the photoconductor is within an appropriate range. I found out. This is demonstrated in the test, the surface the surface free energy of the free energy and lubricants of the photoconductor is required to be 20 mJ / m ² or more 78mJ / m ² or less. Furthermore, when the surface free energy of the lubricant is 42 mJ / m ² or less, the removability of the lubricant by reducing the surface free energy of the photoconductor is further improved. The surface free energy of the lubricant is preferably 28 mJ / m ² or more and 42 mJ / m ² or less as a better range of supply and removal.
The lubricant is applied and removed repeatedly in the image forming apparatus, and the lubricant applied through the charging means each time the drum rotates once undergoes corona discharge.
Therefore, the surface free energy of the lubricant staying on the photoconductor varies depending on the amount of newly supplied lubricant and the amount removed, and the atmosphere such as the magnitude of charge and temperature and humidity. Here, the supply amount of the new lubricant is generally determined by the consumption amount of the lubricant. The amount of lubricant removed is affected by the cleaning ability of the image forming apparatus. Usually, a cleaning blade is used as the cleaning means, and the cleaning ability is enhanced if the shearing force when the photoconductor and the blade come into contact with each other increases. In addition, the amount of toner intervening in cleaning and the ease with which the lubricant and toner become familiar affect the cleaning ability.
The surface free energy of the photoconductor can be adjusted by the material and shape contained in the photoconductor surface. The surface free energy of the lubricant can be adjusted by the amount of lubricant applied.
With the photoconductor having the specific surface free energy and the lubricant, it is possible to eliminate image blur, which has been a problem until now.

In the present invention, the surface free energy is defined as follows.
The surface free energy obtained from the contact angle measurement of the unused photoconductor surface corresponds to (1) in FIG. 1, and is the surface free energy of the initial photoconductor. The surface free energy varies depending on the material and shape contained in the photoconductor surface.
Next, the surface free energy obtained from the contact angle measurement of the photoconductor taken out after being used in an image forming apparatus having means for applying a lubricant for the purpose of durability test or the like is shown in FIG. In order to cope with (2), the surface free energy of the lubricant is used. This is because the photoconductor surface is covered with a lubricant.
The state of (2) does not necessarily need to be 100% covered with the lubricant. If the coverage is 50%, the present invention is evaluated by regarding itself as the surface free energy of the lubricant.
Next, the surface free energy of the photoconductor itself after the durability test cannot be directly measured because the lubricant is applied in the image forming apparatus.
In the present invention, the surface of the photoconductor surface from which the lubricant has been removed is printed for the sake of convenience by printing 100 A3-sized solid black images of the lubricant applied to the photoconductor surface. And the surface. This corresponds to (3) in FIG. 2, and the surface free energy of this surface is the surface free energy of the photoconductor in use.
Although it is conceivable that the lubricant remains strictly even if the lubricant is forcibly removed in this way, such a case is regarded as a modification of the surface of the photoconductor itself.
The initial surface free energy of the photoconductor is low in reproducibility of test results because the transient state of the member affects the test results. Therefore, in the present invention, the “surface free energy of the photoconductor” refers to the surface free energy of the photoconductor in use corresponding to (3) of FIG. In order to confirm the ease of removal of the lubricant during use, it is necessary to evaluate the surface free energy of the photoconductor in a state where the lubricant applied to the photoconductor surface is removed.
In the present invention, the “surface free energy of the photoconductor”, which is the surface free energy of the photoconductor in use, was evaluated based on the value measured after the continuous printing test for 100,000 sheets. It is a volume for eliminating the state, and it is considered that there is no great difference in the surface free energy of the photoconductor after 50,000 or 200,000 sheets. However, if the number of test pieces is several new or the continuous test is performed under the condition that the life of the member is exceeded (for example, 10 million), the reproducibility of the test result is affected by the transient state of the member. Lower. In order to eliminate such influences, values obtained by leveling blades, lubricants and photoconductors are adopted.

In order to improve the abrasion resistance of the photoconductor, it is preferable to increase the surface hardness and elastic power of the surface of the photoconductor used as the photoconductor. Specifically, the Vickers hardness is preferably 31 Hv or more and 870 Hv or less when a force of 2.45 N (0.25 kgf) is applied 30 seconds after the load is applied and a holding time of 5 seconds is provided. The lower limit is a condition that is defined as a value that minimizes uneven wear, and the upper limit is a condition that is defined as a value that suppresses defects such as wrinkles and peeling on the surface of the photoconductor. The Vickers hardness is a value measured at 23 ° C. and 55% RH.
The elastic power is 40% or more, preferably 80% or more. Since the elastic power is often linked with the hardness, in the present invention, it is used as an index with the Vickers hardness as a representative value.
As a measure for obtaining this hardness characteristic, the material of the photoconductor surface is (1) fluorine resin particles and curable resin, or fluorine resin particles and metal oxide particles and curable resin, (2) DLC (diamond-like carbon), (3) A method using any one of ceramics is mentioned.
In a system using a DLC film, the Vickers hardness is 31 Hv (2.45 / 5) or more and 870 Hv (2.45 / 5) or less by reducing the applied bias as much as possible and making the plasma density as high as possible. A photoconductor can be obtained.
In a system using a curable resin, for example, by adding fluororesin particles, the same conductor having a Vickers hardness of 31 Hv (2.45 / 5) or more and 870 Hv (2.45 / 5) or less can be obtained. .

  In order to achieve both the electrostatic characteristics and durability of the photoconductor at a high level, it is advantageous to use a function-separated structure in which a protective layer is provided as a surface layer on the surface of the photoconductor used as the photoconductor. It is.

<Configuration of photoconductor>
The image forming apparatus of the present invention has a photoconductor having a photosensitive layer on a conductive support.
Hereinafter, the photoconductor in the present invention will be described in detail.

<Conductive support>
Examples of the conductive support include those having a volume resistivity of 10 ¹⁰ Ω · cm or less, such as metals such as aluminum, nickel, chromium, nichrome, copper, silver, gold, platinum, iron, tin oxide, A film or cylindrical plastic or paper coated with an oxide such as indium oxide by vapor deposition or sputtering, or a plate made of aluminum, aluminum alloy, nickel, stainless steel, and the like, and a drawing ironing method, impact A tube that has been surface-treated by cutting, super-finishing, polishing, or the like can be used after forming a raw pipe by a method such as an ironing method, an extruded ironing method, an extracted drawing method, or a cutting method.

<Intermediate layer>
In the photoconductor of the present invention, an intermediate layer can be provided between the conductive support and the photosensitive layer. The intermediate layer is provided for the purpose of improving adhesiveness, preventing moire, improving the coatability of the upper layer, and preventing charge injection from the conductive support.

  The intermediate layer usually contains a resin as a main component. Usually, since the photosensitive layer is applied on the intermediate layer, a thermosetting resin that is hardly soluble in an organic solvent is easily used as the resin used for the intermediate layer. In particular, polyurethane, melamine resin, and alkyd-melamine resin are particularly preferable materials because many of them sufficiently satisfy the above-mentioned purpose. A paint obtained by appropriately diluting a resin with a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, or butanone can be used as a coating material.

Further, fine particles such as metal or metal oxide may be added to the intermediate layer in order to adjust conductivity and prevent moire. In particular, titanium oxide or zinc oxide is preferably used.
The fine particles can be dispersed by a ball mill, an attritor, a sand mill, or the like using a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, or butanone to obtain a coating material in which the dispersion and the resin component are mixed.

  The intermediate layer is formed by depositing the above-mentioned paint on a conductive support by a dip coating method, a spray coating method, a bead coating method or the like. If necessary, it is formed by heat curing. In many cases, the thickness of the intermediate layer is suitably about 2 μm to 20 μm. When the accumulation of the residual potential of the photoconductor becomes large, it is preferable to set it to less than 3 μm.

<Photosensitive layer>
The photosensitive layer of the photoconductor is preferably a laminated photosensitive layer in which a charge generation layer and a charge transport layer are sequentially laminated as a photosensitive layer.

-Charge generation layer-
The charge generation layer refers to a part of the laminated photosensitive layer and has a function of generating charges by exposure. This layer is mainly composed of a charge generating substance among the contained compounds. The charge generation layer may use a binder resin as necessary. As the charge generation material, inorganic materials and organic materials can be used.

  Examples of the inorganic material include crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, selenium-arsenic compound, and amorphous silicon. In amorphous silicon, dangling bonds that are terminated with hydrogen atoms or halogen atoms, or those that are doped with boron atoms, phosphorus atoms, or the like are preferably used.

  On the other hand, as the organic material, known materials can be used, for example, metal phthalocyanines such as titanyl phthalocyanine and chlorogallium phthalocyanine, metal-free phthalocyanines, azulenium salt pigments, squaric acid methine pigments, and symmetrical carbazole skeletons. Type or asymmetric azo pigments, symmetric or asymmetric azo pigments having a triphenylamine skeleton, symmetric or asymmetric azo pigments having a fluorenone skeleton, and perylene pigments. Among these, metal phthalocyanines, symmetric or asymmetric azo pigments having a fluorenone skeleton, symmetric or asymmetric azo pigments having a triphenylamine skeleton, and perylene pigments have high quantum efficiency of charge generation. It is suitable as a material used in the invention. These charge generation materials may be used alone or as a mixture of two or more.

  Examples of the binder resin used for the charge generation layer as necessary include, for example, polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, polyarylate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly -N-vinylcarbazole, polyacrylamide, etc. are mentioned. Moreover, the polymeric charge transport material mentioned later can also be used. Of these, polyvinyl butyral is often used and is useful. These binder resins may be used alone or as a mixture of two or more.

  The method for forming the charge generation layer is roughly divided into a vacuum thin film preparation method and a casting method from a solution dispersion system.

  The former method includes a vacuum deposition method, a glow discharge decomposition method, an ion plating method, a sputtering method, a reactive sputtering method, a CVD (chemical vapor deposition) method, and the like. A layer made of the material can be satisfactorily formed.

  In order to provide the charge generation layer by the casting method, the above-described inorganic or organic charge generation material may be ball milled using a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, butanone together with a binder resin if necessary. What is necessary is just to disperse | distribute by an attritor, a sand mill, etc., and apply | coat after diluting a dispersion liquid moderately. Among these solvents, methyl ethyl ketone, tetrahydrofuran, and cyclohexanone are preferable because they have a lower environmental impact than chlorobenzene, dichloromethane, toluene, and xylene. Application can be performed by dip coating, spray coating, bead coating, or the like.

  The thickness of the charge generation layer provided as described above is usually about 0.01 μm to 5 μm.

  When it is necessary to reduce the residual potential or to increase the sensitivity, these characteristics are often improved by increasing the thickness of the charge generation layer. On the other hand, the chargeability often deteriorates, such as charge charge retention and space charge formation. From these balances, the thickness of the charge generation layer is more preferably in the range of 0.05 μm to 2 μm.

  If necessary, a low molecular compound such as an antioxidant, a plasticizer, a lubricant, and an ultraviolet absorber and a leveling agent can be added to the charge generation layer. These compounds can be used alone or as a mixture of two or more. When a low molecular weight compound and a leveling agent are used in combination, sensitivity deterioration often occurs. For this reason, the amount used is generally 0.1 phr to 20 phr, preferably 0.1 phr to 10 phr, and the amount used of the leveling agent is suitably about 0.001 phr to 0.1 phr.

-Charge transport layer-
The charge transport layer refers to a part of the laminated photosensitive layer that functions to inject and transport charges generated in the charge generation layer and to neutralize the surface charge of the photoconductor provided by charging. The main component of the charge transport layer can be referred to as a charge transport component and a binder component that binds the charge transport component.

Examples of the material that can be used for the charge transport material include a low molecular weight electron transport material, a hole transport material, and a polymer charge transport material.
Examples of the electron transporting material include electron accepting materials such as asymmetric diphenoquinone derivatives, fluorene derivatives, naphthalimide derivatives, and the like. These electron transport materials may be used alone or as a mixture of two or more.

  As the hole transport material, an electron donating material is preferably used. Examples thereof include oxazole derivatives, oxadiazole derivatives, imidazole derivatives, triphenylamine derivatives, butadiene derivatives, 9- (p-diethylaminostyrylanthracene), 1,1-bis- (4-dibenzylaminophenyl) propane, Examples include styryl anthracene, styryl pyrazoline, phenylhydrazones, α-phenyl stilbene derivatives, thiazole derivatives, triazole derivatives, phenazine derivatives, acridine derivatives, benzofuran derivatives, benzimidazole derivatives, and thiophene derivatives. These hole transport materials may be used alone or as a mixture of two or more.

  Moreover, the polymeric charge transport material represented below can be used. Examples thereof include a polymer having a carbazole ring such as poly-N-vinylcarbazole, a polymer having a hydrazone structure, a polysilylene polymer, and an aromatic polycarbonate. These polymer charge transport materials can be used alone or as a mixture of two or more.

  The polymer charge transport material is a component of the charge transport layer that is formed on the cross-linked resin surface layer when the cross-linked resin surface layer is laminated on the charge transport layer, as compared with the low-molecular charge transport material. It is a suitable material for preventing bleeding and causing poor curing of the surface layer of the crosslinked resin. Further, since the charge transport material has a high molecular weight, it is advantageous in that it is excellent in heat resistance and is less deteriorated by the heat of curing when the surface layer of the crosslinked resin is formed.

  Examples of the polymer compound that can be used as the binder component of the charge transport layer include polystyrene, polyester, polyvinyl, polyarylate, polycarbonate, acrylic resin, silicone resin, fluorine resin, epoxy resin, melamine resin, urethane resin, and phenol. Examples thereof include thermoplastic or thermosetting resins such as resins and alkyd resins. Of these, polystyrene, polyester, polyarylate, and polycarbonate are useful because many of them have good charge transfer characteristics when used as a binder component of a charge transport component. Further, since the charge transport layer is preferably laminated with a surface layer of a crosslinked resin, the charge transport layer does not require the mechanical strength of the conventional charge transport layer. For this reason, a material such as polystyrene, which has high transparency but a low mechanical strength and is difficult to apply in the prior art, can be effectively used as the binder component of the charge transport layer.

  These polymer compounds can be used singly or as a mixture of two or more kinds, or as a copolymer composed of two or more of these raw material monomers, and further copolymerized with a charge transport material.

  When an electrically inactive polymer compound is used for modifying the charge transport layer, a cardo polymer type polyester having a bulky skeleton such as fluorene, a polyester such as polyethylene terephthalate or polyethylene naphthalate, or a C type polycarbonate A polycarbonate in which the 3,3 ′ portion of the phenol component is alkyl-substituted with respect to a bisphenol-type polycarbonate, a polycarbonate in which the geminal methyl group of bisphenol A is substituted with a long-chain alkyl group having 2 or more carbon atoms, biphenyl Alternatively, polycarbonate having a long-chain alkyl skeleton such as polycarbonate having a biphenyl ether skeleton, polycaprolactone, polycaprolactone, acrylic resin, polystyrene, hydrogenated butadiene, etc. are effective.

  Here, the electrically inactive polymer compound refers to a polymer compound that does not include a chemical structure exhibiting photoconductivity such as a triarylamine structure. When these resins are used in combination with a binder resin as an additive, the amount added is preferably 50% by mass or less based on the total solid content of the charge transport layer, due to restrictions on light attenuation sensitivity.

  When a low molecular charge transport material is used, the amount used is usually 40 phr to 200 phr, preferably about 70 phr to 100 phr. When the polymer charge transporting material is used, a material obtained by copolymerizing the resin component in a proportion of 0 to 200 parts by weight, preferably about 80 to 150 parts by weight with respect to 100 parts by weight of the charge transporting component. Is preferably used.

  In order to satisfy high sensitivity, the charge transport component is preferably added in an amount of 70 phr or more. In addition, α-phenyl stilbene compounds, benzidine compounds, butadiene compound monomers, dimers and polymer charge transport materials having these structures in the main chain or side chain are materials having high charge mobility. Many useful.

  The charge transport layer can be formed by preparing a charge transport layer coating material by dissolving or dispersing a mixture or copolymer mainly composed of a charge transport component and a binder component in an appropriate solvent, and applying and drying the coating material. . As the coating method, a dipping method, a spray coating method, a ring coating method, a roll coater method, a gravure coating method, a nozzle coating method, a screen printing method, or the like is employed.

  Examples of the dispersion solvent that can be used in preparing the charge transport layer coating material include ketones such as methyl ethyl ketone, acetone, methyl isobutyl ketone, and cyclohexanone, ethers such as dioxane, tetrahydrofuran, and ethyl cellosolve, and aromatics such as toluene and xylene. And the like, halogens such as chlorobenzene and dichloromethane, and esters such as ethyl acetate and butyl acetate. Of these, methyl ethyl ketone, tetrahydrofuran, and cyclohexanone are preferable because they have a lower environmental impact than chlorobenzene, dichloromethane, toluene, and xylene. These solvents can be used alone or in combination.

  Since the surface layer of a crosslinked resin is usually laminated on the upper layer of the charge transport layer, the thickness of the charge transport layer in this configuration is made thicker in consideration of film scraping in actual use. No design is required. The thickness of the charge transport layer is practically about 10 μm to 40 μm, more preferably about 15 μm to 30 μm for the purpose of ensuring the necessary sensitivity and charging ability.

  Further, if necessary, a low-molecular compound such as an antioxidant, a plasticizer, a lubricant, and an ultraviolet absorber and a leveling agent can be added to the charge transport layer. These compounds can be used alone or as a mixture of two or more. When a low molecular weight compound and a leveling agent are used in combination, sensitivity deterioration often occurs. For this reason, the amount used is generally 0.1 phr to 20 phr, preferably 0.1 phr to 10 phr, and the amount used of the leveling agent is suitably about 0.001 phr to 0.1 phr.

<Surface layer>
As the surface layer, a surface layer of a curable resin (hereinafter also referred to as a crosslinked resin) is preferable.
The surface layer of the crosslinked resin refers to a protective layer formed on the photoconductor surface. In this protective layer, after coating the coating, a resin having a crosslinked structure is formed by a polymerization reaction of the radical polymerizable material component. Since the resin film has a crosslinked structure, it has the strongest wear resistance among the layers of the photoconductor. In addition, when a crosslinkable charge transporting structural unit is included, the charge transporting property is similar to that of the charge transporting layer.

-Radically polymerizable material component-
Examples of the radical polymerizable material component include acrylates having an acryloyloxy group.
In the present invention, trimethylolpropane, which is also excellent in enhancing the wear resistance of the photoconductor surface, can be suitably used.

As the trifunctional or higher functional binder component, caprolactone-modified dipentaerythritol hexaacrylate and dipentaerythritol hexaacrylate are preferable. This often improves the wear resistance of the crosslinked film itself or increases the toughness.
As the trifunctional or higher functional radical polymerizable monomer having no charge transport structure, trimethylolpropane triacrylate, caprolactone-modified dipentaerythritol hexaacrylate, and dipentaerythritol hexaacrylate are preferable.
These include those of reagent manufacturers such as Tokyo Kasei Co., Ltd., Nippon Kayaku KAYARD DPCA series, and DPHA series.

In addition, an initiator such as Ciba Specialty Chemicals Irgacure 184 may be added in an amount of about 5% by mass to 10% by mass based on the total solid content in order to accelerate or stabilize the curing.
Examples of the crosslinkable charge transport material include a chain polymerization compound having an acryloyloxy group or a styrene group, a sequential polymerization compound having a hydroxyl group, an alkoxysilyl group, or an isocyanate group, and includes a charge transport structure ( A compound having one or more (meth) acryloyloxy groups can be used.
The cross-linked resin surface layer may have a composition in combination with a monomer or oligomer having one or more (meth) acryloyloxy groups not containing a charge transport structure.
The surface layer of the crosslinked resin contains, for example, such a compound in at least a coating solution, and forms a layer by coating the coating solution, such as heat, light, electron beam, γ-ray, etc. It can be cured by crosslinking by applying energy from radiation.
Examples of the compound including the charge transport structure and having one or more (meth) acryloyloxy groups include a charge transport compound represented by the following general formula 1.

However, in the said General formula 1, d, e, and f represent either 0 or 1, respectively. R ₁₃ represents either a hydrogen atom or a methyl group. R ₁₄ and R ₁₅ represent a C 1-6 alkyl group as a substituent other than a hydrogen atom, and may be different in a plurality of cases. g and h each represent an integer of 0 to 3. Z represents a single bond, a methylene group, an ethylene group, or any of the following structures.

The surface layer of the crosslinked resin can be formed, for example, by applying a surface layer coating material of the crosslinked resin containing the radical polymerizable material component and a solvent.
The solvent used when preparing the surface layer coating of the crosslinked resin is preferably a solvent that sufficiently dissolves the monomer. For example, in addition to the above-mentioned ethers, aromatics, halogens, esters, ethoxyethanol, etc. And cellosolves and propylene glycols such as 1-methoxy-2-propanol. Of these, methyl ethyl ketone, tetrahydrofuran, cyclohexanone, and 1-methoxy-2-propanol are preferable because they have a lower environmental impact than chlorobenzene, dichloromethane, toluene, and xylene. These solvents can be used alone or in combination.

  Examples of the coating method for the surface layer coating of the crosslinked resin include dipping method, spray coating method, ring coating method, roll coater method, gravure coating method, nozzle coating method, and screen printing method. In many cases, since the pot life of the paint is not long, a means capable of coating the required amount with a small amount of paint is advantageous in terms of environmental consideration and cost. Of these, the spray coating method and the ring coating method are preferred.

When the surface layer of the cross-linked resin is formed, a UV irradiation light source such as a high-pressure mercury lamp or a metal halide lamp having an emission wavelength mainly in ultraviolet light can be used. In addition, a visible light source can be selected in accordance with the absorption wavelength of the radical polymerizable substance or the photopolymerization initiator. The irradiation light quantity is preferably 50 mW / cm ² or more and 1,000 mW / cm ² or less, and if it is less than 50 mW / cm 2, it takes time for the curing reaction. If it is higher than 1,000 mW / cm ^2, the progress of the reaction becomes non-uniform, and local flaws are generated on the surface of the surface layer of the crosslinked resin, or many unreacted residues and reaction termination ends are generated. In addition, internal stress increases due to rapid crosslinking, which causes cracks and film peeling.

  If necessary, low molecular compounds and leveling agents such as antioxidants, plasticizers, lubricants, UV absorbers and the like described in the charge generation layer in the surface layer of the crosslinked resin, and polymer compounds described in the charge transport layer Can also be added. These compounds can be used alone or as a mixture of two or more. When a low molecular weight compound and a leveling agent are used in combination, sensitivity deterioration often occurs. For this reason, the amount used thereof is generally 0.1% to 20% by weight, preferably 0.1% to 10% by weight, and the amount of leveling agent used is 0.1% to 5% in the total solid content of the paint. About mass% is appropriate.

  The thickness of the surface layer of the crosslinked resin is suitably about 3 μm to 15 μm. The lower limit is a value calculated from the degree of effect on the film forming cost, and the upper limit is set from electrostatic characteristics such as charging stability and light attenuation sensitivity, and uniformity of film quality.

In particular, a protective layer in which a filler is dispersed in a resin is preferable.
Fillers added to the protective layer include organic and inorganic fillers.
Examples of organic fillers include fluororesin fillers such as polytetrafluoroethylene, silicone resin fillers, fillers mainly composed of carbon, and inorganic filler materials include copper, tin, aluminum, indium, etc. Metal oxides, silicon oxide, silica, tin oxide, zinc oxide, titanium oxide, indium oxide, antimony oxide, bismuth oxide, tin oxide doped with antimony, metal oxides such as indium oxide doped with tin, Inorganic materials such as potassium titanate can be mentioned.
In particular, it is advantageous to use an inorganic material or a filler material mainly composed of carbon. In particular, metal oxides are good for inorganic materials, and silicon oxide, aluminum oxide, titanium oxide, and the like can be used effectively. Furthermore, diamond filler can be used effectively for fillers mainly composed of carbon.
Moreover, a fluororesin filler can be used effectively as the organic filler.
You may use a fluororesin filler and metal oxide particle together.

The particle size of the filler is preferably 0.1 μm or more and 3 μm or less, more preferably 0.2 μm or more and 0.5 μm or less.
The higher the filler concentration of the protective layer, the better the abrasion resistance, but the better. However, the writing light transmittance is lowered, which may cause side effects. Therefore, it is approximately 50% by mass or less, preferably 30% by mass or less, based on the total solid content. The lower limit is usually 5% by mass.
The film thickness of the protective layer in which the filler is dispersed in the resin is suitably from 0.5 μm to 10 μm, and preferably from 1.0 μm to 6.0 μm.

<Protective layer: DLC (diamond-like carbon)>
The protective layer having a diamond-like carbon structure preferably has a C—C bond similar to that of diamond having SP3 orbits.
Note that a film having a structure similar to graphite having SP2 orbits may be used, or an amorphous film may be used.
The protective layer having a diamond-like carbon structure contains additive elements such as nitrogen, fluorine, boron, phosphorus, chlorine, bromine and iodine for resistance control, light transmission control, mechanical property control, and the like. It doesn't matter.

When producing a protective layer having a diamond-like carbon structure, a carrier gas such as H ₂ or Ar is used with hydrocarbon gas (methane, ethane, ethylene, acetylene, etc.) as a main material.
Furthermore, the gas for supplying the additive element may be any gas that can be vaporized under reduced pressure, or any gas that can be vaporized by heating. For example, NH ₃ , N ₂ or the like is used as a gas for supplying nitrogen, C ₂ F ₆ , CH ₃ F or the like is used as a gas for supplying fluorine, B ₂ H ₆ or the like is used as a gas for supplying boron, phosphorus PH ₃ or the like is used as the gas supplying chlorine, CH ₃ Cl, CH ₂ Cl ₂ , CHCl ₃ , CCl ₄ or the like is used as the gas supplying chlorine, and CH ₃ Br or the like is used as the gas supplying bromine. As the gas for supplying iodine, CH ₃ I or the like can be used.
As a gas for supplying a plurality of additive elements, NF ₃ , BCl ₃ , BBr, BF ₃ , PF ₃ , PCl _{3 and the} like are used.

The protective layer having a diamond-like carbon structure is formed by a plasma CVD method, a glow discharge decomposition method, a photo CVD method, or a sputtering method using graphite or the like as a target, using the gas as described above.
Although the film forming method is not particularly limited, as a method for forming a carbon-based film having good characteristics as a protective layer, the film is formed with a sputtering effect while being a plasma CVD method. Methods are known.

In the method of forming a protective layer mainly composed of carbon using the plasma CVD method, it is not necessary to heat the support in particular, and a film can be formed at a low temperature of about 150 ° C. or lower. There is also an advantage that there is no problem when the protective layer is formed on the layer.
The thickness of the protective layer having a diamond-like carbon structure is desirably 0.2 μm or more and 5.0 μm or less.

  An example of a method for forming a protective layer having a diamond-like carbon or amorphous carbon structure using a plasma CVD method is shown below. The photosensitive layer produced as described above is set in a plasma CVD apparatus as shown in FIGS. 11 to 13, and a protective layer made of carbon or a thin film containing carbon as a main component is formed. In FIG. 11, reference numeral 107 denotes a vacuum chamber of a plasma CVD apparatus, which is partitioned from a load / unload spare chamber 117 by a gate valve 109. The inside of the vacuum chamber 107 is evacuated by an exhaust system 120 (comprising a pressure adjusting valve 121, a turbo molecular pump 122, and a rotary pump 123), and is kept at a constant pressure. A reaction tank 150 is provided in the vacuum tank 107. The reaction tank has a frame-like structure 102 (having a square or hexagonal shape as viewed from the electrode side) as shown in FIGS. 12 and 13, and hoods 108, 118, which cover the openings at both ends. Furthermore, it comprises a pair of first and second electrodes 103 and 113 (using a metal mesh such as aluminum) having the same shape and disposed on the hoods 108 and 118. Reference numeral 130 denotes a gas line to be introduced into the reaction tank 150, to which various material gas containers are connected, and each is introduced into the reaction tank 150 from the nozzle 125 via the flow meter 129.

  In the frame-like structure 102, supports 101 (101-1, 101-2,... 101-n) on which the photosensitive layer is formed are arranged as shown in FIGS. Each of the supports is disposed as a third electrode as will be described later. For the electrodes 103 and 113, a pair of power sources 115 (115-1 and 115-2) for applying a first alternating voltage is prepared. The frequency of the first alternating voltage is 1 to 100 MHz. These power sources are connected to matching transformers 116-1 and 116-2, respectively. The phase in the matching transformer is adjusted by the phase adjuster 126 and can be supplied with a shift of 180 ° or 0 ° from each other. That is, it has a symmetrical or in-phase output. The one end 104 and the other end 114 of the match transformer are connected to the first and second electrodes 103 and 113, respectively. Further, the output-side midpoint 105 of the transformer is held at the ground level. Further, a second alternating voltage is applied between the midpoint 105 and the third electrode, that is, the support 101 (101-1, 101-2... 101-n) or a holder electrically connected to them. Power supply 119 is provided. The frequency of the second alternating voltage is 1 to 500 KHz. The output of the first alternating voltage applied to the first and second electrodes is 0.1 to 1 kW at a frequency of 13.56 MHz, and the second alternating voltage applied to the third electrode, that is, the support. Is about 100 W for a frequency of 150 KHz.

<Protective layer: Ceramics>
First, a method for forming a ceramic protective layer by an aerosol deposition method in a vacuum process will be described.
In this case, an aerosol deposition apparatus as shown in FIG. 3 is used. In the gas cylinder 11 shown in FIG. 3, an inert gas for generating an aerosol is stored.
The gas cylinder 11 is connected to an aerosol generator 13 via a pipe 12 a, and the pipe 12 a is drawn out to the inside of the aerosol generator 13. A certain amount of particles 20 made of a metal oxide or a compound semiconductor is introduced into the aerosol generator 13. Another pipe 12 b connected to the aerosol generator 13 is connected to the injection nozzle 15 inside the film forming chamber 14.

  Inside the film forming chamber 14, the substrate 16 is held by the substrate holder 17 so as to face the spray nozzle 15. Here, an aluminum foil (positive electrode current collector) is used as the substrate 16. An exhaust pump 18 for adjusting the degree of vacuum in the film forming chamber 14 is connected to the film forming chamber 14 via a pipe 12c.

  Although not shown, the film forming apparatus for forming the protective layer according to the present embodiment moves the substrate holder 17 in the lateral direction (the lateral direction in the plane opposite to the ejection nozzle 15 in the substrate holder 17), and the ejection nozzle 15 Is moved at a constant speed in the vertical direction (the vertical direction in the plane facing the injection nozzle 15 in the substrate holder 17). By performing film formation while moving the substrate holder 17 in the horizontal direction and the injection nozzle 15 in the vertical direction, an active material layer having a desired area can be formed on the substrate 16.

  In the step of forming the protective layer, first, the pneumatic valve 19 is closed, and the exhaust pump 18 evacuates the film formation chamber 14 to the aerosol generator 13. Next, by opening the pneumatic valve 19, the gas in the gas cylinder 11 is introduced into the aerosol generator 13 through the pipe 12a, the particles 20 are sprinkled into the container, and the aerosol in which the particles 20 are dispersed in the gas is generated. Let The generated aerosol is jetted at high speed from the nozzle 15 toward the substrate 16 through the pipe 12b. When 0.5 seconds elapses with the pressure pneumatic valve 19 opened, the pressure pneumatic valve 19 is closed for the next 0.5 seconds. Thereafter, the pneumatic valve 19 is opened again, and the pneumatic valve 19 is repeatedly opened and closed with a period of 0.5 seconds. The gas flow rate from the gas cylinder 11 is 2 liters / minute, the film formation time is 7 hours, the degree of vacuum in the film formation chamber 14 when the pressure valve 19 is closed is about 10 Pa, and the pressure valve 19 is open. At this time, the degree of vacuum in the film forming chamber 14 is set to about 100 Pa.

The spraying speed of the aerosol is controlled by the shape of the nozzle 15, the length and inner diameter of the pipe 12b, the gas internal pressure of the gas cylinder 11, the exhaust amount of the exhaust pump 18 (internal pressure of the film forming chamber 14), and the like.
For example, when the internal pressure of the aerosol generator 13 is tens of thousands Pa, the internal pressure of the film forming chamber 14 is several hundred Pa, and the shape of the opening of the nozzle 15 is a circular shape having an inner diameter of 1 mm, the film is formed with the aerosol generator 13. Due to the internal pressure difference with the chamber 14, the aerosol injection speed can be set to several hundreds m / sec. If the internal pressure of the film forming chamber 14 is maintained at 5 to 100 Pa and the internal pressure of the aerosol generator 13 is maintained at 50000 Pa, a lithium cobalt oxide layer having a porosity of 5 to 30% can be formed. It is preferable to adjust the thickness of the protective layer to 0.1 to 10 μm by adjusting the time for supplying the aerosol under these conditions.

  The particles 20 in the aerosol that have been accelerated to obtain kinetic energy collide with the substrate 16 and are finely crushed by the impact energy. Then, these crushed particles are bonded to the substrate 16 and the crushed particles are bonded to each other, whereby a protective layer is sequentially formed on the charge transport layer.

The film is formed by a plurality of line patterns and rotation of the photoconductor drum. A protective layer having a desired area is formed while the substrate holder 17 and the injection nozzle 15 are scanned in the vertical and horizontal directions on the surface of the substrate 16. As the method, first, the vertical direction is fixed, and the substrate holder 17 is scanned at a constant speed in the horizontal direction. When the scanning of one row is completed, the injection nozzle 15 is moved in the vertical direction in consideration of the overlap with the previous film formation area, and the substrate holder 17 is scanned in the horizontal direction. In this way, a desired film-forming area is deposited by moving a plurality of times in the vertical direction until reaching a desired vertical position and repeating the scan in the horizontal direction.
Any metal oxide is used for the particles. Specific examples include alumina, copper aluminate (CuAlO ₂ ), zinc oxide, titanium oxide and the like.

<Lubricant>
For the above requirements, wax or higher fatty acid metal salt is advantageous as a material used for the lubricant. As the wax, plant waxes such as goose wax, urushi wax, palm wax and carnauba wax, animal waxes such as beeswax, whale wax, ibota wax and wool wax, and mineral waxes such as montan wax and paraffin wax can be used.

  In particular, many of the higher fatty acid metal salts that have been generally used in the past are advantageous in terms of the properties of the material. This representative compound, zinc stearate, is a compound that can have a lamellar structure. A lamellar structure is a structure in which layers formed by regularly folding molecules are stacked and arranged. This lamellar structure has a layered structure in which amphiphilic molecules are self-organized, and when a shearing force is applied, the crystal is easily broken along the layers. This action is advantageous for establishing the circulation of the lubricant.

  The characteristic of the lamellar structure in which zinc stearate receives a shearing force and uniformly covers the surface of the photoconductor can effectively cover the surface of the photoconductor with a small amount of lubricant. When applying a lubricant by this method, there are various methods for controlling the application state of the lubricant. For example, means for increasing the contact pressure between the solid lubricant and the application brush or controlling the rotation speed of the application brush can be considered. There is also an attempt to control the rotation speed of the application brush according to the image formation information.

  As the lubricant, a wax or a higher fatty acid metal salt may be used alone, but these can be used as a binder by mixing with other functional materials such as a charge transport material and an antioxidant.

  In order to identify materials that are easy to form and remove in the image forming apparatus using such a lubricant, it is possible to enjoy the effect of easily obtaining the equivalence of the amount of substances during the repeated steps of removing the lubricant and coating. it can. For this reason, the module responsible for applying and removing the lubricant can be simplified. In addition, the lubricant film can be formed for a long time. Furthermore, by combining with the shape of the surface layer described above, it is possible to achieve a particularly high covering capacity per cycle, and to enjoy a reduction in the consumption rate of the lubricant.

  Furthermore, as the lubricant in the present invention, the fatty acid metal salt capable of taking a lamellar structure contains at least one fatty acid of stearic acid, palmitic acid, myristic acid, oleic acid, and zinc, aluminum, calcium, Fatty acid metal salts containing at least one metal among magnesium and lithium are preferred. In particular, a mixture of zinc stearate and zinc palmitate is preferred.

  Zinc stearate is the most preferable material in terms of cost, quality, stability and reliability because it is produced on an industrial scale and has been used in many fields. In addition, there is an advantage that it is easy to apply abundant application techniques that have been accumulated as an effective application method of the lubricant. In addition, the higher fatty acid metal salt generally used industrially is not a compound simple substance composition of its name, but includes other more or less similar fatty acid metal salt, metal oxide, and free fatty acid, and the fatty acid of the present invention. Metal salts follow this convention.

  By using such a lubricant, high reliability and cost reduction can be enjoyed with respect to the formation of the lubricant film. In addition, it is possible to obtain the convenience of device development that facilitates application of accumulated coating technology as lubricant coating technology.

(Image forming device)
A configuration example of the image forming apparatus will be described below with reference to the drawings. The image forming apparatus according to the present invention is provided with means for supplying a lubricant, which will be described later, to the surface of a photoconductor (hereinafter also referred to as an electrophotographic photoreceptor). This point will be described later.

FIG. 4 is a schematic view showing an example of an image forming apparatus according to the present invention, and modifications as will be described later are also included in the present invention.
4, the electrophotographic photoreceptor 11 has a surface Vickers hardness of 31 Hv (2.45 / 5) or more and 870 Hv (2.45 / 5) or less, and a surface free energy of 20 mJ / m ² or more and 78 mJ /. It is an electrophotographic photosensitive member having m ² or less. The electrophotographic photosensitive member 11 has a drum shape, but may be a sheet shape or an endless belt shape.

  The charging device 12 is a means for uniformly charging the surface of the electrophotographic photosensitive member 11, and known means such as a corotron, a scorotron, a solid state charger (solid state charger), and a charging roller are used. The charging device 12 is preferably used in contact with or close to the electrophotographic photosensitive member 11 from the viewpoint of reducing power consumption. In particular, in order to prevent the charging device 12 from being contaminated, a charging mechanism disposed in the vicinity of the electrophotographic photosensitive member 11 having an appropriate clearance between the electrophotographic photosensitive member 11 and the surface of the charging device 12 is desirable. In general, the charger 16 can be used as the transfer device 16, but a combination of a transfer charger and a separation charger is effective.

  Light sources used in the exposure apparatus 13 and other forms of static eliminators (1A in FIG. 5) include fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light emitting diodes (LEDs), and semiconductor lasers (LDs). , And general luminescent materials such as electroluminescence (EL). Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.

  The toner 15 developed on the electrophotographic photosensitive member 11 by the developing device 14 is transferred to a printing medium 18 such as printing paper or an OHP slide, but not all is transferred and remains on the electrophotographic photosensitive member. Toner is also generated. Such toner is removed from the electrophotographic photosensitive member 11 by the cleaning device 17. The cleaning device 17 can be a rubber cleaning blade, a brush such as a fur brush, a mag fur brush, or the like.

When the electrophotographic photosensitive member 11 is positively (negatively) charged by the charging device 12 and image exposure is performed by the exposure device 13, a positive (negative) electrostatic latent image is formed on the surface of the electrophotographic photosensitive member 11. . If this is developed with negative (positive) polarity toner (electrodetection fine particles) by the developing device 14, a positive image is obtained, and if developed with positive (negative) toner, a negative image is obtained. A known method is applied to the developing device 14, and a known method is also used for the static eliminator.
The toner image developed on the print medium 18 is conveyed to a fixing device 19 from a position where the electrophotographic photosensitive member 11 and the transfer device 16 are opposed to each other, and is fixed on the print medium 18 by the fixing device 19.

  The lubricant 3A, the application brush 3B for applying the lubricant, and the application blade 3C are disposed downstream of the cleaning device 17 and upstream of the charging device 12 in the rotation direction of the electrophotographic photosensitive member 11. These arrangement relationships are the same in other embodiments described below.

FIG. 5 shows another example of the image forming apparatus. In FIG. 5, the electrophotographic photoreceptor 11 has a surface Vickers hardness of 31 Hv (2.45 / 5) or more and 870 Hv (2.45 / 5) or less, and a surface free energy of 20 mJ / m ² or more and 78 mJ / m. ^The electrophotographic photosensitive member 11 is ² or less. The electrophotographic photosensitive member 11 has a belt shape, but may be a drum shape, a sheet shape, or an endless belt shape. The electrophotographic photosensitive member 11 is driven by the driving means 1C, charged by the charging device 12, image exposure by the exposure device 13, development, transfer by the transfer device 16, exposure before cleaning by the exposure device 1B before cleaning, cleaning by the cleaning device 17, The charge removal by the charge removal apparatus 1A is repeated. The lubricant 3 </ b> A, the application brush 3 </ b> B for applying the lubricant, and the application blade 3 </ b> C are arranged between the cleaning device 17 and the charging device 12 as shown in the drawing with respect to the moving direction of the electrophotographic photoreceptor 11.

  In FIG. 5, light irradiation for pre-cleaning exposure is performed from the support side of the electrophotographic photoreceptor 11 (in this case, the support is translucent).

  The above-described electrophotographic process is an example. For example, in FIG. 5, the pre-cleaning exposure is performed from the support side, but this may be performed from the photosensitive layer side, or image exposure and neutralization light irradiation may be performed. You may carry out from the support body side. On the other hand, image exposure, pre-cleaning exposure, and static elimination exposure are illustrated in the light irradiation process. In addition, a pre-transfer pre-exposure, image exposure pre-exposure, and other known light irradiation processes are provided in the electrophotographic photoreceptor. Light irradiation can also be performed.

  The image forming means as described above may be fixedly incorporated in a copying machine, a facsimile machine, or a printer, but may be incorporated in these apparatuses in the form of a process cartridge. There are many types of process cartridges, but a typical example is shown in FIG. The electrophotographic photosensitive member 11 has a drum shape, but may be a sheet shape or an endless belt shape.

  FIG. 7 shows another example of the image forming apparatus. In this image forming apparatus, a developing device 14Bk, 14C for each of the charging device 12, the exposure device 13, black (Bk), cyan (C), magenta (M), and yellow (Y) around the electrophotographic photosensitive member 11 is provided. , 14M, 14Y, an intermediate transfer belt 1F as an intermediate transfer member, and a cleaning device 17 are arranged in this order.

Note that the subscripts (Bk, C, M, Y) shown in FIG. 7 correspond to the color of the toner described above, and are omitted as appropriate. The electrophotographic photosensitive member 11 is Vickers hardness of the surface 31Hv (2.45 / 5) above 870Hv (2.45 / 5) or less, and the surface free energy is 20 mJ / m ² or more 78mJ / m ² or less An electrophotographic photoreceptor. Each color developing device 14Bk, 14C, 14M, 14Y can be controlled independently, and only the color developing device for image formation is driven. The toner image formed on the electrophotographic photosensitive member 11 is transferred onto the intermediate transfer belt 1F by the first transfer device 1D disposed inside the intermediate transfer belt 1F.

The first transfer device 1D is disposed so as to be able to come into contact with and separate from the electrophotographic photosensitive member 11, and the intermediate transfer belt 1F is brought into contact with the electrophotographic photosensitive member 11 only during the transfer operation. Each color image is sequentially formed, and the toner images superimposed on the intermediate transfer belt 1F are collectively transferred to the print medium 18 by the second transfer device 1E, and then fixed by the fixing device 19 to form an image. .
The second transfer device 1E is also arranged so as to be able to contact and separate from the intermediate transfer belt 1F, and contacts the intermediate transfer belt 1F only during the transfer operation.

  In the transfer drum type image forming apparatus, since the toner images of the respective colors are sequentially transferred to the print medium electrostatically attracted to the transfer drum, there is a limitation on the print medium that printing on thick paper is not possible, as shown in FIG. Such an intermediate transfer type image forming apparatus has an advantage that the toner images of the respective colors are superimposed on the intermediate transfer body 1F, and thus are not limited by the print media. Such an intermediate transfer method can be applied not only to the apparatus shown in FIG. 7, but also to the image forming apparatus as shown in FIGS. 4, 5, and 6 and FIGS.

  The lubricant 3 </ b> A, the application brush 3 </ b> B for applying the lubricant, and the application blade 3 </ b> C are arranged between the cleaning device 17 and the charging device 12 as shown in the figure with respect to the rotation direction of the electrophotographic photoreceptor 11.

FIG. 8 shows another example of the image forming apparatus. This image forming apparatus is of a type that uses four colors of yellow (Y), magenta (M), cyan (C), and black (Bk) as toner, and an image forming unit is provided for each color. In addition, electrophotographic photoreceptors 11Y, 11M, 11C, and 11Bk for each color are provided. The electrophotographic photoreceptor 11 used in this image forming apparatus has a surface Vickers hardness of 31 Hv (2.45 / 5) or more and 870 Hv (2.45 / 5) or less, and a surface free energy of 20 mJ / m ² or more. It is an electrophotographic photosensitive member of 78 mJ / m ² or less. Around each electrophotographic photosensitive member 11Y, 11M, 11C, 11Bk, charging devices 12Y, 12M, 12C, 12Bk, exposure devices 13Y, 13M, 13C, 13Bk, developing devices 14Y, 14M, 14C, 14Bk, cleaning devices 17Y, 17M, 17C, 17Bk, etc. are arranged.

  In addition, a transfer transfer belt 1G as a transfer material carrier that comes in contact with and separates from the transfer positions of the electrophotographic photosensitive members 11Y, 11M, 11C, and 11Bk arranged on a straight line is stretched by a driving unit 1C. . Transfer devices 16Y, 16M, 16C, and 16Bk are disposed at transfer positions facing the electrophotographic photoreceptors 11Y, 11M, 11C, and 11Bk with the conveyance transfer belt 1G interposed therebetween.

  The tandem type image forming apparatus shown in FIG. 8 has electrophotographic photoreceptors 11Y, 11M, 11C, and 11Bk for each color, and sequentially transfers the toner images of the respective colors onto the print medium 18 held on the transport transfer belt 1G. Compared to a full-color image forming apparatus having only one electrophotographic photosensitive member, it is possible to output a full-color image much faster. The toner image developed on the print medium 18 as a transfer material is conveyed to a fixing device 19 from a position where the electrophotographic photoreceptor 11Bk and the transfer device 16Bk are opposed to each other, and is fixed to the print medium 18 by the fixing device 19.

  Further, for example, the configuration in the embodiment as shown in FIG. 9 may be used. That is, instead of the direct transfer method using the transfer transfer belt 1G shown in FIG. 8, the intermediate transfer belt 1F can be used as shown in FIG.

  In the example shown in FIG. 9, each color has electrophotographic photoreceptors 11Y, 11M, 11C, and 11Bk, and an intermediate transfer belt in which toner images of the respective colors formed on these are driven and stretched by a roller 1C that is a driving means. The first transfer means 1D, which is the first transfer means, is sequentially transferred and laminated on 1F to form a full-color image.

  Next, the intermediate transfer belt 1F is further driven, and the full-color image carried on the intermediate transfer belt 1F is opposed to the secondary transfer unit 1E that is the second transfer device and the roller that is disposed to face the secondary transfer unit 1E. It is transported to the position. Then, the image is secondarily transferred to the transfer material 18 by the secondary transfer unit 1E, and a desired image is formed on the transfer material.

(Lubricant supply means)
As shown in FIG. 10, as a lubricant supply means for supplying the lubricant 3 </ b> A to the surface of the electrophotographic photosensitive member 11, the lubricant application device 3 is provided for all the image forming apparatuses described above. The lubricant application device 3 applies or regulates an application brush (fur brush) 3B as an application member, a lubricant 3A, a pressure spring 3D for pressing the lubricant in the direction of the fur brush, and the lubricant 3A. It has a coating blade 3C for the purpose.

  The lubricant 3A is a lubricant molded into a bar shape. The fur brush 3B has a brush tip in contact with the surface of the electrophotographic photosensitive member. By rotating about the shaft, the lubricant 3A is once drawn into the brush, and the fur brush 3B is moved to the contact position with the surface of the electrophotographic photosensitive member 11 on the brush. And is applied to the surface of the electrophotographic photoreceptor 11.

  Further, even if the lubricant 3A is scraped by the fur brush 3B over time, the lubricant 3A is pressed against the fur brush 3B with a predetermined pressure by the pressurizing spring 3D so that the lubricant 3A does not come into contact with the fur brush 3B. Has been. As a result, even a small amount of the lubricant 3A is always uniformly drawn into the fur brush 3B.

  Further, a lubricant supply device for coating the surface of the electrophotographic photoreceptor 11 with the lubricant 3A may be provided. This means includes means for pressing a plate such as a cleaning blade against the electrophotographic photosensitive member 11 by a trailing method or a counter method.

  Lubricant 3A is, for example, fatty acid metal salts such as lead oleate, zinc oleate, copper oleate, zinc stearate, cobalt stearate, iron stearate, copper stearate, zinc palmitate, copper palmitate, zinc linolenate, etc. Fluorine series such as polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, polytrifluorochloroethylene, dichlorodifluoroethylene, tetrafluoroethylene-ethylene copolymer, tetrafluoroethylene-oxafluoropropylene copolymer Resin. In particular, a material having a lamellar structure has high circulation efficiency, and zinc stearate is advantageous in terms of cost.

(Process cartridge)
The process cartridge of the present invention comprises a photoconductor carrying an electrostatic latent image, a developing means for developing the electrostatic latent image carried on the photoconductor with toner to form a visible image, and lubrication And other means such as a charging means, an exposure means, a transfer means, a cleaning means, a static elimination means, and the like, and at least a lubricant supply means for supplying the agent onto the photoconductor It has.

The developing means includes at least a developer container that contains the toner or the developer, and a developer carrier that carries and transports the toner or developer contained in the developer container. In addition, a layer thickness regulating member for regulating the thickness of the toner layer carried on the developer carrying member may be provided. Specifically, any one of the one-component developing unit and the two-component developing unit described in the image forming apparatus and the image forming method can be preferably used.
Further, as the charging unit, the exposure unit, the transfer unit, the cleaning unit, and the charge eliminating unit, the same ones as those of the above-described image forming apparatus can be appropriately selected and used.
The process cartridge can be detachably provided in various electrophotographic image forming apparatuses, facsimiles, and printers, and it is particularly preferable that the process cartridge is detachably provided in the image forming apparatus of the present invention.

The image forming method of the present invention includes a step of supplying a lubricant to the photoconductor, and the photoconductor has a surface Vickers hardness of 31 Hv (2.45 / 5) or more and 870 Hv (2.45 / 5). or less, and the surface free energy of the photoconductive material is 20 mJ / m ² or more 78mJ / m ² or less, supplying the lubricant, the surface free energy of the lubricant 20 mJ / m ² or more 78MJ / M ² is a step of applying a lubricant so as to be less than or equal to m ² .
The step of supplying the lubricant can be performed using means for supplying the lubricant.

  Examples of the present invention will be described below, but the present invention is not limited to the following examples. In the following examples, “parts” and “%” mean “parts by mass” and “% by mass”, respectively.

(1) Surface Free Energy First, a method for measuring surface free energy according to the present invention will be described.
For the calculation of the surface free energy of the photoconductor, after completion of the 100,000 continuous printing test described below, after printing 100 sheets of all solid images of A3 size in a state where the supply of the lubricant is cut off, the electrophotographic apparatus The photoconductor was taken out of the photoconductor, the contact angle of the photoconductor in this state was measured, and the surface free energy was calculated.
Further, the surface free energy of the lubricant is the state in which the lubricant is applied to the surface of the photoconductor after completion of the 100,000 continuous printing test described below. The contact angle of the photoconductor surface was measured by simply blowing away dust and dust with a blower.
The measurement was performed at 23 ° C. and 55% RH.

For the contact angle measurement, an automatic contact angle meter (CA-W, manufactured by Kyowa Interface Science Co., Ltd.) was used. Further, ion-exchanged water, methylene iodide, and α-bromonaphthalene were selected as standard materials.
The measured contact angle for each standard substance and the surface free energy value of the standard substance are the data described in Noriaki Kitasaki, Toshio Hata et al., Journal of Japan Adhesion Association 8 (3), 131-141 (1972) (Table 1). Was used to calculate the adhesion work between the standard substance and the sample (photoconductor and photoconductor coated with a lubricant) using the following equation (1).
In the following formula:
γ: surface free energy γ ^a : nonpolar wetting γ ^b : wetting by polarity γ ^c : wetting by hydrogen bonding W _{Solid Liquid} : wettability between solid liquids γ _Liquid : surface free energy of liquid θ: contact angle W12: 1 And 2 wettability γ ₁ ^a : 1 non-polar wetting γ ₁ ^b : 1 polar wetting.

Next, simultaneous equations are established using the adhesive strength of methylene iodide, α-bromonaphthalene and the sample, and the following formula 2.
Here, the data of the above-mentioned data is used for γ ₁ ^a and γ ₁ ^b of standard substances.
From this, √γ ^a and √γ ^b of the sample were calculated.
Following the work of adhesion between the water and the photosensitive member, and was calculated √Ganma ^c samples using the number 2.
The surface free energy of the photoconductor was calculated from √γ ^a , √γ ^b , √γ ^c and Equation 3 of the obtained photoconductor.
However, the surface free energy was measured at intervals of 10 mm from end to end of the photoreceptor width in order to eliminate measurement errors, and the average value was defined as the surface free energy.

(2) Blur image evaluation Superiority or inferiority was evaluated from comparison of halftone image patterns printed as evaluation images described later. The evaluation criteria were as follows.
(Bokeh image rank)
Rank 5: Image blur is not identified Rank 4: An image where subtle image blur occurs is received Rank 3: Subtle image blur is identified, but there is no practical problem Rank 2: Slight image blur is identified Rank 1 : Clear image blur is identified

(3) Evaluation of background stain The background stain was evaluated using image analysis software imageJ (distributed by NIH, USA) on a print image of an all-white pattern described later captured by a 1200 dpi image scanner. The evaluation criteria were as follows. Here, “%” represents an image area ratio.
(Skin dirt rank)
Rank 5: Less than 0.01% Rank 4: 0.01% to less than 0.02% Rank 3: 0.02% to less than 0.07% Rank 2: 0.07% to less than 0.29% Rank 1: 0.29% or more

Example 1
-Production of photoconductor-
The following intermediate layer coating solution was applied to an aluminum support (outer diameter φ100 mm) by an immersion method to form an intermediate layer. The film thickness of the intermediate layer after drying at 170 ° C. for 30 minutes was 10 μm.
(Intermediate layer coating solution)
-Zinc oxide particles (MZ-300, manufactured by Teika Co., Ltd.): 350 parts-1,3,5-tris (3-mercaptobutyryloxyethyl)
-1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione:
1.5 parts (Karenz (registered trademark) MT NR1, manufactured by Showa Denko KK)
Blocked isocyanate: 60 parts (Sumijoule (registered trademark) 3175, solid content concentration 75%, manufactured by Sumika Bayer Urethane Co., Ltd.)
-20% solution obtained by dissolving butyral resin with 2-butanone: 225 parts (BM-1, manufactured by Sekisui Chemical Co., Ltd.)
・ 2-butanone: 365 parts

On the obtained intermediate layer, the following charge generation layer coating solution was dip coated to form a charge generation layer.
The film thickness of the charge generation layer was 0.3 μm.
(Coating solution for charge generation layer)
・ Y-type titanyl phthalocyanine: 6 parts ・ Butyral resin (ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.): 4 parts ・ 2-butanone (manufactured by Kanto Chemical): 200 parts

On the resulting charge generation layer, the following charge transport layer coating solution was dip coated to form a charge transport layer.
The film thickness of the charge transport layer after drying at 135 ° C. for 20 minutes was 22 μm.
(Coating liquid for charge transport layer)
-Bisphenol Z-type polycarbonate: 10 parts (Panlite TS-2050, manufactured by Teijin Chemicals Ltd.)
・ Low molecular charge transport material represented by the following structural formula: 10 parts
Tetrahydrofuran: 80 parts

(Surface layer)
On the obtained charge transport layer, the following coating solution for the surface layer of the crosslinked resin was spray-coated in a nitrogen stream, and then left in the nitrogen stream for 10 minutes to dry the touch. Thereafter, light irradiation was performed in a UV irradiation booth in which the inside of the booth was replaced with nitrogen gas so that the oxygen concentration was 2% or less.
Furthermore, it dried at 130 degreeC for 20 minutes, and obtained the photoconductor of Example 1. The film thickness of the surface layer of the crosslinked resin was 2.5 μm.
(Light irradiation conditions)
・ Metal halide lamp: 160W / cm
・ Irradiation distance: 120mm
-Irradiation intensity: 700 mW / cm ²
・ Irradiation time: 60 seconds

(Crosslinked resin surface layer coating solution (vehicle))
Trimethylolpropane triacrylate: 5 parts (KAYARAD TMPTA, Nippon Kayaku Co., Ltd., acrylic equivalent 99, trifunctional or more radical polymerizable compound having no charge transporting structure)
Dipentaerythritol caprolactone-modified hexaacrylate: 5 parts (KAYARAD DPCA-120, manufactured by Nippon Kayaku, acrylic equivalent 324)
-Radical polymerizable compound having a monofunctional charge transport structure of the following structural formula (acryl equivalent 420): 10 parts
1-hydroxy-cyclohexyl-phenyl-ketone: 1 part (Irgacure 184, manufactured by Ciba Specialty Chemicals, photopolymerization initiator)
Tetrahydrofuran: 119 parts Silicone oil (KF-50-100CS, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.0042 parts

[Dispersion of fluororesin fine particles]
In a 50cc mayonnaise bottle,
・ Φ1mm PSZ ball 112.5 parts ・ Perfluoroalkoxy fluororesin (PFA) 11.25 parts (MPE-056, Mitsui, manufactured by DuPont Fluorochemical)
Fluorine-based graft polymer solution: 2.4 parts (GF-400, manufactured by Toagosei Co., Ltd.)
Fluorine-based solvent: 65.35 parts (Zeorolla-H, manufactured by Zeon Corporation)
Was added, and the mayonnaise bottle was rotated at a rotation speed of 160 rpm for 24 hours to separate the PSZ balls to obtain a dispersion of fluororesin fine particles.
A film was formed using a surface layer coating solution of a crosslinked resin obtained by pouring 95 parts of a surface layer coating solution (vehicle) into 5 parts of this dispersion.

After the photoconductor of Example 1 produced as described above was used for mounting, it was mounted on a black developing station of an electrophotographic apparatus (Ricoh Pro C901, manufactured by Ricoh Co., Ltd.) in an environment of 30 ° C. and 90% in an environment of 100,000. A continuous printing test of sheets was performed. The amount of lubricant consumed relative to the photoconductor travel at this time was 220 mg / km. After completion of the test, the power switch was turned off and left for 16 hours, and then a halftone image pattern and all white patterns were printed as evaluation images. The image evaluation was performed by classifying the blurred image and background stain of the evaluation image into five ranks.
All the lubricants used were RICOH PRO C901 genuine products. The lubricant is a mixture of zinc stearate and zinc palmitate. In the image forming apparatus, a lubricant molded in a stick shape is used. The lubricant is applied to the surface of the photoreceptor by rubbing with a brush that rotates. As the lubricant application means, a genuine product of RICOH PRO C901 is used as it is.
The amount of lubricant consumed is calculated as a value obtained by dividing the amount of lubricant lost by the distance traveled by the photoconductor.
For the continuously printed image, a test pattern having an image area ratio of 5% in which characters and rectangular patches are arranged uniformly over the entire A4 size was selected.

(Example 2)
About the surface layer coating solution of the crosslinked resin of Example 1, the surface layer coating solution of the crosslinked resin obtained by pouring 80 parts of the surface layer coating solution (vehicle) of the crosslinked resin into 20 parts of the dispersion of fluororesin fine particles. A photoconductor was obtained in the same manner as in Example 1 except that was used and evaluated in the same manner as in Example 1.

(Example 3)
A photoconductor was obtained in the same manner as in Example 1 except that the blending ratio of the dispersion of fluororesin fine particles and the surface layer coating solution (vehicle) of the crosslinked resin in Example 1 was changed in order from 30 parts to 70 parts, Evaluation was performed in the same manner as in Example 1.

Example 4
[Alumina filler dispersion]
In a 50cc mayonnaise bottle,
・ Φ5mm alumina ball: 60 parts ・ Alumina filler: 9 parts (Sumicorundum AA-03, Sumitomo Chemical Co., Ltd., average primary particle size: 0.3 μm)
Dispersant: 0.36 parts (50% THF solution of BYK-P105 (Bic Chemie))
Cyclopentanone: 9.8 parts added, rotated at 160 rpm for 24 hours, then removed alumina balls and diluted with THF to a solid content concentration of 27% was used as alumina filler dispersion .

  The mixing ratio of the solid content of the surface layer coating solution of the crosslinked resin of Example 1, the solid content of the dispersion of the fluororesin fine particles of Example 1 and the solid content of the dispersion of the alumina filler is 85: 7: 8. A photoconductor was obtained in the same manner as in Example 1 except that the surface layer coating solution prepared by blending the coating solution was used, and evaluated in the same manner as in Example 1.

(Example 5)
A photoconductor was obtained in the same manner as in Example 1 except that the surface layer in the photoconductor of Example 1 was changed, and evaluated in the same manner as in Example 1.
[Formation of protective layer]
A film in which an intermediate layer, a charge generation layer, and a charge transport layer were formed on an aluminum support was set in a plasma CVD apparatus. Three kinds of gases, C ₂ H ₄ (60 ml / min), H ₂ (150 ml / min), and NF ₃ (40 ml / min) are used as source gases, PIG power 500 W, coil current 5 A, substrate bias −100 V, A DLC film having a film thickness of 0.5 μm with a volume resistance changed under the condition of a reaction pressure of 0.21 Pa was formed.

(Example 6)
A photoconductor was obtained in the same manner as in Example 5 except that the substrate bias was changed to −400 V with respect to the film forming conditions of the protective layer in Example 5 and evaluated in the same manner as in Example 1.

(Example 7)
Using the photoconductor obtained in Example 5, the test was performed in the same manner as in the continuous print test in Example 5, except that the amount of lubricant consumed relative to the photoconductor travel distance was changed to 320 mg / km. .
(Example 8)
Using the photoconductor obtained in Example 5, the test was conducted in the same manner as in the continuous print test in Example 5, except that the amount of lubricant consumed relative to the mileage of the photoconductor was changed to 300 mg / km. .
Example 9
Using the photoconductor obtained in Example 5, the test was conducted in the same manner as in the continuous print test in Example 5, except that the amount of lubricant consumed relative to the photoconductor travel distance was changed to 150 mg / km. .
(Example 10)
Using the photoconductor obtained in Example 5, the test was conducted in the same manner as in the continuous print test in Example 5, except that the amount of lubricant consumed with respect to the mileage of the photoconductor was changed to 130 mg / km. .

(Example 11)
A photoconductor was obtained in the same manner as in Example 1 except that the surface layer of Example 1 was changed to the following, and evaluated in the same manner as the photoconductor of Example 1.
[Formation of protective layer]
A film in which an intermediate layer, a charge generation layer, and a charge transport layer were formed on an aluminum support was set in a plasma CVD apparatus. Three kinds of gases, C ₂ H ₄ (90 ml / min), H ₂ (150 ml / min), and NF ₃ (45 ml / min) are used as source gases, RF power (13.56 MHz) 100 W, substrate bias −100 V Then, a DLC film having a film thickness of 0.5 μm, in which the volume resistance was changed under the reaction pressure of 2.6 Pa, was formed.

(Comparative Example 1)
For the cross-linked resin surface layer coating solution of Example 1, a photoconductor was obtained in the same manner as in Example 1 except that the fluororesin fine particle dispersion was not used, and was evaluated in the same manner as in Example 1. In this case, the surface free energy of the photoconductor was 81 mJ / cm ² .
(Comparative Example 2)
A photoconductor was obtained in the same manner as in Example 1 except that the blending ratio of the dispersion of fluororesin fine particles and the surface layer coating liquid (vehicle) of the crosslinked resin in Example 1 was changed to 55 parts to 45 parts in order, Evaluation was performed in the same manner as in Example 1. In this case, the surface free energy of the photoconductor was 18 mJ / cm ² .
(Comparative Example 3)
A photoconductor was obtained in the same manner as in Example 5 except that the formation of the protective layer in Example 5 was changed to the following conditions and evaluated in the same manner as in Example 1. In this case, the surface free energy of the photoconductor was 80 mJ / cm ² .
[Formation of protective layer]
A film in which an intermediate layer, a charge generation layer, and a charge transport layer were formed on an aluminum support was set in a plasma CVD apparatus. Using C ₂ H ₄ (200 ml / min) and Air (50 ml / min) gas as source gas, volume resistance is changed under conditions of PIG power 500 W, coil current 10 A, substrate bias −400 V, reaction pressure 0.2 Pa. A DLC film having a thickness of 0.5 μm was formed. In this case, the surface free energy of the photoconductor was 80 mJ / cm ² .
The evaluation results are shown in Table 2.

As described above, as described in the embodiments, according to the present invention, it is possible to dramatically improve the durability of the photoconductor and to provide an image forming apparatus in which electrophotography can be sufficiently adapted to commercial printing. .
In addition, the printing cost can be reduced.

(About Figure 3)
DESCRIPTION OF SYMBOLS 11 Gas cylinder 12a, 12b, 12c Piping 13 Aerosol generator 14 Deposition chamber 15 Injection nozzle 16 Substrate 17 Substrate holder 18 Exhaust pump 19 Pneumatic valve 20 Particles

(About FIGS. 4 to 10)
DESCRIPTION OF SYMBOLS 1A Static elimination apparatus 1B Exposure apparatus before cleaning 1C Drive means 1D 1st transfer apparatus 1E 2nd transfer apparatus 1F Intermediate transfer body 1G Conveyance transfer belt 3 Lubricant application apparatus 3A Lubricant 3B Application brush 3C Application blade 3D Pressure spring 11 , 11Bk, 11C, 11M, 11Y Electrophotographic photosensitive member 12, 12Y, 12M, 12C, 12Bk Charging device 13, 13Y, 13M, 13C, 13Bk Exposure device 14, 14Bk, 14C, 14M, 14Y Developing device 15 Toner 16, 16Y , 16M, 16C, 16Bk Transfer device 17, 17Y, 17M, 17C, 17Bk Cleaning device 18 Print media 19 Fixing device

(About FIGS. 11-13)
101-1 to 101-n Support body 102 Frame-like structure 103, 113 Electrode 104, 114 Matching transformer end 105 Transformer output side midpoint 107 Vacuum chamber 108, 118 Hood 109 Gate valve 115 Power supply 116-1, 116- 2 Matching transformer 117 Spare room for loading / unloading 119 Power supply 120 Exhaust system 121 Adjusting valve 122 Turbo molecular pump 123 Rotary pump 125 Gas introduction nozzle 126 Phase adjuster 129 Flow meter 130 to 134 Gas line 140 Alternating power system 150 Reaction tank

JP 2004-325686 A

Claims (5)

A photoconductor and means for supplying a lubricant to the photoconductor, the photoconductor having a surface Vickers hardness of 31 Hv (2.45 / 5) or more and 870 Hv (2.45 / 5) or less. There, and an image forming apparatus surface free energy of the surface free energy and lubricants of the photoconductor is 20 mJ / m ² or more 78mJ / m ² or less.   The image forming apparatus according to claim 1, wherein the photoconductor has a Vickers hardness of 36 Hv (2.45 / 5) or more and 870 Hv (2.45 / 5) or less.   The photoconductor has a surface layer, and the surface layer is (1) fluorine resin particles and curable resin, or fluorine resin particles and metal oxide particles and curable resin, (2) DLC, and (3) ceramics. The image forming apparatus according to claim 1, wherein the image forming apparatus is any one of the above. The image forming apparatus according to claim 1, wherein a surface free energy of the lubricant is 28 mJ / m ² or more and 42 mJ / m ² or less. A step of supplying a lubricant to the photoconductor, wherein the photoconductor has a surface Vickers hardness of 31 Hv (2.45 / 5) or more and 870 Hv (2.45 / 5) or less; the surface free energy of the conductor is at 20 mJ / m ² or more 78mJ / m ² or less, so step of supplying the lubricant, the surface free energy of the lubricant is 20 mJ / m ² or more 78mJ / m ² or less An image forming method which is a step of applying a lubricant.