JP2006259389A - Image forming apparatus and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming method capable of achieving higher picture quality of an image, maintaining image stability for a long time, in particular, extending a photoreceptor life and a cleaning performance life, and forming a uniform image without a defect for a long time, and to provide an image forming apparatus that can carry out the method. <P>SOLUTION: The image forming apparatus and the image forming method employ a photoreceptor having a protective layer as an outermost surface layer, and the following toner set. In the toner set, toner of one to three colors in cyan toner, magenta toner, yellow toner and black toner contains an abrasive as an external additive; another toner contains a lubricant as an external additive; the toner containing the abrasive does not contain the lubricant as an external additive; and the toner containing the lubricant does not contain the abrasive as an external additive. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

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

Conventionally, in electrophotography, an electrostatic latent image created by charging and exposing the surface of a photoconductor is developed with colored toner to create a visible image, and the toner image is transferred onto a transfer paper or the like, and this is heated roll. For example, the image is formed by fixing. Since untransferred toner, external additives, and discharge products remain on the surface of the photoreceptor after the transfer process, it is necessary to remove them by a cleaning unit prior to the next image forming process.
Various cleaning methods such as a method using a fur brush or a magnetic brush or a method using an elastic cleaning blade are used as a cleaning means for removing transfer residual toner, etc., but the photosensitive member is rubbed with the cleaning blade. The means for scraping off the toner is generally used because it is simple and inexpensive.

Originally, the frictional resistance between the elastic blade and the photosensitive member is large, and the elastic blade cannot be slid by itself, but additives such as fine particles added to the toner are released from the toner, and the elastic blade and the photosensitive member. It is thought that lubrication is carried out by interposing between them.
However, the inclusion of fine particles fluctuates depending on the output image or is not supplied in non-image forming cycles, so the inclusion of lubrication components becomes non-uniform and unstable, especially in high-temperature and high-humidity conditions where the frictional force increases and alternating electric fields In some cases, for example, when a contact charging device such as a contact charging roll that applies the above is used, friction between the elastic blade and the photosensitive member locally increases. Due to the increased friction, damage such as blade chattering, chipping or chipping of the cleaning edge, or scratches on the surface of the photoconductor, the removal performance of toner, toner components, and discharge products that must be cleaned. And the stable cleaning performance cannot be maintained over a long period of time.

On the other hand, in recent years, image quality has been improved in this type of image forming apparatus, and as one means for improving the image quality, a polymerization method is used to reduce the diameter of the toner, reduce the spherical shape, and narrow the particle size distribution. It is getting ahead. By reducing the diameter and narrowing the particle size distribution, the reproducibility of dots formed on the photoreceptor can be improved, and by developing to a spherical shape, the developability and transferability can be improved.
However, since the toner having a narrow particle size distribution and a nearly spherical shape has better fluidity than the conventional irregularly pulverized toner, the toner retention at the cleaning edge of the blade is poor, and it is more difficult to ensure stable lubrication of the blade. In addition, blade cleaning of spherical toner is difficult, and particularly when the blade damage and the photoconductor scratch are deteriorated, the cleaning performance is remarkably deteriorated as compared with the conventional irregularly pulverized toner. Actually, it is difficult to extend the life of a process cartridge including a cleaning blade / photosensitive member due to this defective cleaning.

In order to solve these problems, proposals have been made to improve the wear resistance of the photoconductor and extend the life of the photoconductor, and the present applicant has proposed a photoconductor having a cross-linked structure and a structural unit having a charge transporting ability. The body was proposed as a long-life photoconductor (see, for example, Patent Document 1). It has been found that these photoconductors are overwhelmingly superior in thermal and mechanical strength to conventional ones, so that deterioration due to abrasion of the surface layer can be remarkably reduced, and the life can be extended.
However, since this photoconductor has high strength and is difficult to wear, the discharge product adhering particularly when the photoconductor is charged is difficult to remove from the surface of the photoconductor, and image flow due to moisture absorption of the discharge product is likely to occur. there were. In addition, since the discharge product is difficult to remove, the surface friction of the photosensitive member is likely to increase, and the cleaning blade is accelerated in damage.

In order to solve these problems, a method of adding a long-chain barium carboxylate to the photosensitive layer has been disclosed (for example, see Patent Document 2). Moreover, adding the transport material containing a long-chain alkylcarboxylic acid group is disclosed (for example, refer patent document 3). Further, it is disclosed that a charge transport material containing a fluoroalkyl group and fluororesin fine particles are added (for example, see Patent Document 4). Further, it is disclosed that a lubricating substance is contained in the photosensitive layer (see, for example, Patent Document 5). Further, it is disclosed that a photosensitive layer is impregnated with a fully fluorinated oil (for example, see Patent Document 6).
In addition, many methods have been proposed to solve the above problems by adding silicone resin, fluororesin, etc., but when these lubricating components are dispersed or dissolved at the time of preparing the coating liquid, and added, Moreover, there existed a problem which produced phase separation in a coating film, or produced defects, such as a coating film repelling at the time of film forming. In addition, there was a problem in that no defect was caused, such as difficulty in sustaining the effect due to material segregation (bleed). On the other hand, impregnation with fully fluorinated oil after formation of the photosensitive layer is free from the risk of defects during preparation of the photosensitive layer, and as a method that can form a uniform film even with materials that are difficult to be compatible. Although it is effective, even a fully fluorinated oil that has been impregnated is used because it has a high degree of molecular freedom and is unimproved due to poor compatibility with the material forming the photosensitive layer. There was a problem that segregation (bleeding) of the material sometimes occurred and it was difficult to ensure the sustainability of the effect.

  In addition, it has been proposed to warm the photoconductor with a heater or the like against image flow due to moisture absorption of discharge products on the photoconductor using a siloxane resin (see, for example, Patent Document 7 or 8). It is possible to remove moisture absorbed by warming the photosensitive member with a heater or the like and effectively prevent image flow. However, this method still has the problems that the power consumption of the image forming apparatus increases, the arrangement of the heater inside the photoconductor and the power supply mechanism to the heater are required, and the apparatus becomes complicated and the cost increases. . In addition, it is a technology that removes only moisture that has absorbed moisture rather than removing the discharge product itself, so it cannot prevent the increase in friction of the photoconductor due to the discharge product adhering, and it has a sufficient effect on blade damage Was not obtained.

  Further, a combination of a specific brush roll and an elastic rubber blade has been proposed as a means for effectively removing deposits on the surface of the photoreceptor using a photoreceptor using a siloxane resin having high film strength (for example, Patent Document 9). reference.). However, in this method, when spherical toner is used or a contact charger is used, blade damage cannot be effectively avoided.

It has also been proposed to supply zinc stearate or the like to the photoreceptor for the purpose of lubricating the blade of the photoreceptor using a siloxane resin (see, for example, Patent Document 10 or 11). According to this method, even with a photoconductor using a siloxane resin with little wear, the lubrication of the cleaning blade can be controlled by zinc stearate. However, the zinc stearate lubricant coating layer on the photoconductor surface can be used. The removability of the discharge product that entered was deteriorated, and a sufficient effect was not obtained with respect to image flow suppression.
In addition, for the purpose of refreshing the lubricant film, it has been conventional to mix an abrasive with toner or the like. However, since the lubricant and the abrasive are mixed in the blade nip, a wear-resistant photosensitive member is particularly used. When used, it has been difficult to achieve both lubrication and refreshing of the photoreceptor.
Japanese Patent No. 3264218 JP 2003-167368 A JP-A-11-109659 JP 11-218945 A JP 2000-75515 A Japanese Patent Laid-Open No. 2002-278122 JP 2000-241998 A JP 2002-91269 A JP 2001-51576 A JP 2001-255684 A JP 2001-265040 A

  The present invention has been made in view of the above-described conventional problems, and can improve image quality and maintain image stability over a long period of time. An object of the present invention is to provide an image forming method capable of forming a uniform image without any problem and an image forming apparatus capable of performing the method.

  As a result of intensive studies to achieve the above object, the present inventors have determined the polishing component in the case of creating a color image using a single photoreceptor having a protective layer on the outermost surface layer and four color toners. The inventors have found that the above object can be achieved by using a toner set composed of toner containing toner and toner containing a lubricating component, and have completed the present invention. That is, the present invention

  <1> A photoconductor, a charging unit that uniformly charges the photoconductor, a latent image forming unit that forms a latent image on the surface of the charged photoconductor, and a latent image formed on the surface of the photoconductor Developing means for developing a toner image with a developer containing at least toner, an intermediate transfer body on which the toner image formed on the surface of the photoreceptor is primarily transferred, and formed on the surface of the photoreceptor. A primary transfer means for primary transfer of the toner image to the intermediate transfer body; a secondary transfer means for secondary transfer of the toner image primarily transferred to the intermediate transfer body to the transfer body; and a transfer to the transfer body. At least a fixing unit for fixing the toner image, and a cleaning unit including a cleaning blade for removing residual toner on the surface of the photoconductor after transfer, and cyan, magenta, yellow and black on the surface of the photoconductor. An image forming apparatus in which each toner image is formed and each color toner image is sequentially primary-transferred from the photoreceptor to the intermediate transfer body to form a color image, wherein the outermost surface layer of the photoreceptor is a protective layer. Yes, among cyan, magenta, yellow and black toners, one to three color toners contain an abrasive as an external additive, and the other toners contain a lubricant as an external additive. An image forming apparatus using a toner set in which the toner containing does not contain the lubricant as an external additive, and the toner containing the lubricant does not contain the abrasive as an external additive.

  <2> The image forming apparatus according to <1>, wherein the abrasive is amorphous inorganic fine powder having a Mohs hardness of 3 or more and a volume average particle size of 0.03 to 0.8 μm.

  <3> The image forming apparatus according to <1> or <2>, wherein the lubricant is at least one selected from fatty acid metal salts and higher alcohols.

  <4> The image forming apparatus according to any one of <1> to <3>, wherein a shape factor SF of the toner is 115 to 140.

  <5> The image forming apparatus according to any one of <1> to <4>, wherein the toner has a volume average particle diameter of 3 to 9 μm.

  <6> The image forming apparatus according to any one of <1> to <5>, wherein a resilience of a portion of the cleaning blade that contacts the photoconductor is 30% or less.

  <7> The image forming apparatus according to any one of <1> to <6>, wherein a portion of the cleaning blade in contact with the photosensitive member has a JISA hardness of 80 ° or more.

  <8> The image forming apparatus according to any one of <1> to <7>, wherein the protective layer includes a resin having a crosslinked structure including a structural unit having charge transporting ability.

  <9> A structural unit having a charge transporting ability, including a structural unit having a charge transporting ability, wherein the structural unit having a charge transporting ability has a methylol group as a resin having a crosslinked structure, and a hydroxyl group And a charge transport material having at least one selected from a carboxyl group, an alkoxysilyl group, an epoxy group, a thiol group, and an amino group.

  <10> A charging step for uniformly charging the surface of the photoconductor, a latent image forming step for forming a latent image on the surface of the charged photoconductor, and at least a latent image formed on the surface of the photoconductor A developing step of developing with a developer containing a toner image to form a toner image, a primary transfer step of primarily transferring the toner image formed on the surface of the photoreceptor to an intermediate transfer member, and a primary transfer to the intermediate transfer member A secondary transfer process for secondary transfer of the toner image to the transfer body, a fixing process for fixing the toner image transferred to the transfer body, and residual toner on the surface of the photoreceptor after transfer by a cleaning blade At least a cleaning step for removing toner images of cyan, magenta, yellow, and black on the surface of the photoconductor, and sequentially transferring the toner images of each color from the photoconductor An image forming method in which a color image is formed by primary transfer to a photosensitive member, wherein the outermost surface layer of the photoconductor is a protective layer, and one to three colors of cyan toner, magenta toner, yellow toner and black toner are selected. A toner includes an abrasive as an external additive, another toner includes a lubricant as an external additive, a toner including the abrasive does not include the lubricant as an external additive, and a toner includes the lubricant. This is an image forming method using a toner set that does not contain the abrasive as an external additive.

  According to the present invention, an image forming method capable of achieving high image quality and maintaining image stability over a long period of time, in particular, extending the life of the photoreceptor and the cleaning performance, and forming a uniform image without defects over a long period of time. And an image forming apparatus capable of performing the method.

Hereinafter, the image forming apparatus and the image forming method of the present invention will be described in detail.
<Image forming apparatus>
The image forming apparatus according to the present invention includes a photosensitive member, a charging unit that uniformly charges the photosensitive member, a latent image forming unit that forms a latent image on the charged surface of the photosensitive member, and a surface of the photosensitive member. Developing means for developing the formed latent image with a developer containing at least toner to form a toner image, an intermediate transfer member on which the toner image formed on the surface of the photosensitive member is primarily transferred, and the photosensitive member A primary transfer means for primary transfer of the toner image formed on the surface of the intermediate transfer body to the intermediate transfer body, a secondary transfer means for secondary transfer of the toner image primarily transferred to the intermediate transfer body to the transfer body, A fixing unit that fixes the toner image transferred to the transfer member; and a cleaning unit that includes a cleaning blade that removes residual toner on the surface of the photosensitive member after the transfer. Magenta An image forming apparatus for forming a color image by forming toner images of yellow and black, and sequentially transferring toner images of respective colors from the photosensitive member to the intermediate transfer member in order, and forming an image on the outermost surface layer of the photosensitive member Is a protective layer, among cyan toner, magenta toner, yellow toner and black toner, one to three color toners contain an abrasive as an external additive, and other toners contain a lubricant as an external additive, The toner containing the abrasive does not contain the lubricant as an external additive, and the toner containing the lubricant uses a toner set that does not contain the abrasive as an external additive.

  In the image forming apparatus of the present invention, when a color image is formed, cyan (C) toner, magenta (M) toner, yellow (Y) toner, and black (K) toner are in a predetermined order on the surface of a single photoconductor. Supplied in. In the toner set according to the present invention, among the four color toners, one to three color toners include an abrasive as an external additive, and the other toners include a lubricant as an external additive, and include the abrasive. Since the toner does not contain the lubricant as an external additive, and the toner containing the lubricant does not contain the abrasive as an external additive, the lubricant and the abrasive are alternately supplied to the surface of the photoreceptor. The

By providing a protective layer on the outermost surface layer of the photoconductor according to the present invention, a photoconductor having high wear resistance can be formed.
By adding a lubricant to toner of one to three colors among the four colors (CMYK), it is possible to suppress friction between the cleaning blade and the photosensitive member, and to extend the blade life. As for the removal of deposits such as discharge products, which is a problem with wear-resistant photoreceptors, a charging agent can be obtained by adding an abrasive to one-color to three-color toner that does not contain a lubricant as an external additive. It is possible to effectively polish and refresh the lubricant film contaminated with the outermost surface layer of the photoconductor and the discharge product or the like which has been altered by the discharge stress.
Since the abrasive released from the toner has a small diameter, it is presumed that the abrasive enters the cleaning edge and improves the polishing effect of the photoreceptor. In the present invention, blade lubrication by forming a lubricant film and refreshing by an abrasive can be carried out independently for each cycle of printing on the photoreceptor, so that blade life extension and photosensitivity, which could not be achieved with the conventional abrasive / lubricant simultaneous mixing system, can be achieved. The body surface refresh can be controlled at the same time.

  The image forming apparatus of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an example of an embodiment of an image forming apparatus of the present invention. In FIG. 1, an image forming apparatus of the present invention is arranged around a photoconductor 1 in order along a rotation direction indicated by an arrow A, a charger 2, an image writing means 3 such as a laser beam, a developing device 4, a primary transfer. The developing device 4, the cleaning device 6, and the like are disposed, and toners of black, yellow, magenta, and cyan are accommodated in the developing devices 4 a to 4 d of the developing device 4. A transfer belt 7, which is an intermediate transfer member that is in contact with the photosensitive member 1 and travels between the photosensitive member 1 and the primary transfer unit 5 in the direction of arrow B, is stretched between tension rolls 8 a, 8 b, 8 c and a backup roll 9. It is built. A bias roll 10 and a belt cleaner 11 are disposed at positions facing the backup roll 9 and the tension roll 8a, respectively.

  In FIG. 1, a portion where the primary transfer unit 5 presses the photosensitive member 1 via the transfer belt 7 becomes a primary transfer portion, and a portion where the bias roll 10 presses the backup roll 9 becomes a secondary transfer portion. A toner image is transferred from the transfer belt 7 to the transfer sheet P, which is a transfer target, supplied from the paper feed tray 13 to the secondary transfer unit in the direction of arrow C, and sent to the fixing device 14 to be transferred to the toner image. Is established.

The photosensitive member 1 is charged by using the charger 2, and as a charging means, a voltage is applied to a non-contact type charger such as corotron or scorotron and a conductive member brought into contact with the surface of the photosensitive member. Therefore, a contact-type charger for charging the photosensitive member can be used, and any type of charger may be used. However, a contact charging type charging device is preferred from the viewpoint of producing an effect that the amount of ozone generated is small, is environmentally friendly and has excellent printing durability.
In the contact charging type charging device, the shape of the conductive member may be any of a brush shape, a blade shape, a pin electrode shape, a roller shape, and the like, and is not limited.

  A latent image is formed on the surface of the charged photoreceptor 1 using the image writing means 3. For example, a laser optical system or an LED array is used as the image writing means 3.

The latent image formed on the surface of the photoreceptor 1 is developed with a developer containing toner to form a toner image. For example, a developer carrying member having a developer layer formed on the surface thereof is brought into contact with or close to the photoreceptor 1, and toner particles are attached to the latent image on the surface of the photoreceptor 1 to form a toner image.
As the developing device 4, a known device can be used, but as a developing device using a two-component developer, there are developing devices such as a cascade method and a magnetic brush method.

The toner image formed on the surface of the photoreceptor 1 is transferred to the transfer belt 7 by the primary transfer unit 5. Cyan, magenta, yellow, and black toners are transferred onto the transfer belt 7 to form a full-color image. For example, a corotron can be used as the primary transfer unit 5, but is not limited thereto.
In this embodiment, a transfer belt is used as the intermediate transfer member, but a drum-shaped intermediate transfer member can also be used.
As the intermediate transfer member, for example, a semiconductive belt in which an appropriate amount of an antistatic agent such as carbon black is contained in a resin such as acrylic, vinyl chloride, polyester, polycarbonate, polyimide, or various rubbers can be used. .

  Examples of the bias roll 10 include a roll portion made of a rubber material such as urethane, EPDM (polyisopyrene / blend elastomer), CR (chloroprene rubber), silicone rubber, or a foamed sponge of these materials. The hardness of this roll part is about 40 degrees with an ASKER C 500 gram load (hereinafter abbreviated as g) as a JIS standard. This hardness is effective not only for stabilizing the transfer performance of the transfer paper P but also for preventing the character blanking phenomenon during transfer of the toner image.

  As the fixing device 14, a heat fixing device using a heat roll is preferably used. The heat-fixing device includes a fixing roller in which a so-called release layer is formed by a heat-resistant resin coating layer or a heat-resistant rubber coating layer on the outer peripheral surface of a heating lamp in a cylindrical metal core, and the fixing roller. The pressure roller or pressure belt is disposed in pressure contact with the roller and has a heat-resistant elastic body layer formed on the outer peripheral surface of the cylindrical metal core or the surface of the belt-like base material. The fixing process of an unfixed toner image is performed by inserting a transfer body on which an unfixed toner image is formed between a fixing roller and a pressure roller or a pressure belt, and using a binder resin, an additive, etc. in the toner. Fix by heat melting. In the present invention, the fixing device 14 is not particularly limited.

A cleaning blade is used as the cleaning device 6. The cleaning blade used in the present invention preferably has a rebound resilience of 30% or less at a portion in contact with the photoreceptor 1. By setting the blade rebound resilience to 30% or less and suppressing blade edge vibration, so-called stick-and-slip, the abrasive easily stays in the cleaning nip, and the adhering matter removing effect can be improved. In addition, the impact resilience in this invention is based on JISK6301, and says the measured value in 25 degreeC.
The impact resilience of the cleaning blade is more preferably 20% or less, and particularly preferably 15% or less.

  In the present invention, it is preferable that the JISA hardness of the portion of the cleaning blade contacting the photoreceptor 1 is 75 ° or more. By setting the blade hardness to 75 ° or more, distortion variation of the blade edge can be suppressed to a small extent, and the retention property of the blade edge of the abrasive is improved. By increasing the hardness of the blade and reducing the distortion, the horizontal force, which is the force to push back the particles staying at the blade edge, increases, making it difficult for the abrasive to slip through and further improving the deposit removal effect. . In addition, the JISA hardness in this invention is based on JISK6301, and says the measured value in 25 degreeC. The JISA hardness is more preferably 80 ° or more, and particularly preferably 85 ° or more.

A known rubber material can be used as the blade material. For example, urethane rubber, silicon rubber, fluorine rubber, chloroprene rubber, butadiene rubber, or the like can be used. Among them, urethane rubber (polyurethane elastic body) is preferably used because of its excellent wear resistance.
As the polyurethane elastic body, a polyurethane generally synthesized through an addition reaction between an isocyanate and a polyol and various hydrogen-containing compounds is used. As a polyol component, a polyether-based polyol such as polypropylene glycol or polytetramethylene glycol, Polyester polyols such as adipate polyols, polycaprolactam polyols, polycarbonate polyols and the like, and polyisocyanate components such as tolylene diisocyanate, 4,4'diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, toluidine diisocyanate, etc. Polyisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, dicyclo It is manufactured by preparing a urethane prepolymer using an aliphatic polyisocyanate such as xylmethane diisocyanate, adding a curing agent to the urethane prepolymer, pouring it into a predetermined mold, crosslinking and curing, and then aging at room temperature. ing. As the curing agent, a dihydric alcohol such as 1,4-butanediol and a trihydric or higher polyhydric alcohol such as trimethylolpropane or pentaerythritol are usually used in combination.

The photoreceptor 1 is not particularly limited as long as it has a protective layer on the outermost surface layer, but is not limited to a conductive substrate, a photosensitive layer formed on the conductive substrate, and the charge transport layer. It is preferable to have at least a surface layer (protective layer) formed on the surface.
The photosensitive layer may be composed of only one layer, or may be a function-separated type photosensitive layer composed of a charge generation layer and a charge transport layer. When the photosensitive layer is a function separation type, a mode in which a charge generation layer and a charge transport layer are laminated in this order from the conductive substrate side is preferable.

Examples of conductive substrates include metal plates, metal drums, metal belts, or conductive polymers using metals or alloys such as aluminum, copper, zinc, stainless steel, chromium, nickel, molybdenum, vanadium, indium, gold, platinum, etc. In addition, a paper, a plastic film, a belt, or the like coated, vapor-deposited, or laminated with a conductive compound such as indium oxide or a metal or alloy such as aluminum, palladium, or gold.
When the photoreceptor is used in a laser printer, the laser oscillation wavelength is preferably from 350 nm to 850 nm, and the shorter wavelength is preferable because the resolution is excellent. In order to prevent interference fringes generated when laser light is irradiated, the surface of the conductive substrate is preferably roughened to a center line average roughness Ra of 0.04 μm to 0.5 μm. As a roughening method, wet honing performed by suspending an abrasive in water and spraying the substrate, or centerless grinding, anodizing, in which a substrate is pressed against a rotating grindstone, and grinding is continuously performed, It is preferable to prepare a layer containing treatment with an acidic treatment liquid, boehmite treatment, organic or inorganic semiconductive fine particles, and the like. If Ra is smaller than 0.04 μm, the effect of preventing interference cannot be obtained because it is close to a mirror surface, and if Ra is larger than 0.5 μm, the image quality becomes rough even if a film is formed on the conductive substrate, which is not suitable. . When non-interfering light is used as a light source, it is not particularly necessary to roughen the interference fringes, and it is possible to prevent the occurrence of defects due to irregularities on the surface of the conductive substrate.

  The anodizing treatment is to form an oxide film on the aluminum surface by anodizing in an electrolyte solution using aluminum as an anode. Examples of the electrolyte solution include a sulfuric acid solution and an oxalic acid solution. However, the intact porous anodic oxide film is chemically active, easily contaminated, and has a large resistance fluctuation due to the environment. Therefore, the pores in the anodized film are sealed with pressurized water vapor or boiling water (a metal salt such as nickel may be added) by volume expansion due to a hydration reaction, and a sealing process is performed to change to a more stable hydrated oxide. . The thickness of the anodic oxide film is preferably 0.3 to 15 μm. When it is thinner than 0.3 μm, the barrier property against injection is poor and the effect is not sufficient. On the other hand, if it is thicker than 15 μm, the residual potential increases due to repeated use.

  Moreover, the treatment of the conductive substrate with an acidic treatment liquid comprising phosphoric acid, chromic acid and hydrofluoric acid is carried out as follows. The mixing ratio of phosphoric acid, chromic acid and hydrofluoric acid in the acidic treatment liquid is such that phosphoric acid is in the range of 10 to 11% by mass, chromic acid is in the range of 3 to 5% by mass, and hydrofluoric acid is in the range of 0.5 to 2% by mass. The concentration of these acids as a whole is preferably in the range of 13.5 to 18% by mass. The processing temperature is 42 to 48 ° C., but by keeping the processing temperature high, a thicker film can be formed faster. About the film thickness of a film, 0.3-15 micrometers is preferable. When it is thinner than 0.3 μm, the barrier property against injection is poor and the effect is not sufficient. On the other hand, if it is thicker than 15 μm, the residual potential increases due to repeated use.

  The boehmite treatment of the conductive substrate can be performed by immersing in pure water at 90 to 100 ° C. for 5 to 60 minutes or by contacting with heated steam at 90 to 120 ° C. for 5 to 60 minutes. About the film thickness of a film, 0.1-5 micrometers is preferable. This can be further anodized using an electrolyte solution with low film solubility such as adipic acid, boric acid, borate, phosphate, phthalate, maleate, benzoate, tartrate, citrate. Good.

  Examples of organic or inorganic semiconductive fine particles include perylene pigments, bisbenzimidazole perylene pigments, polycyclic quinone pigments, indigo pigments, quinacridone pigments, and the like described in JP-A-47-30330. And organic pigments such as bisazo pigments and phthalocyanine pigments having electron-withdrawing substituents such as nitro, nitroso and halogen atoms, and inorganic pigments such as zinc oxide, titanium oxide and aluminum oxide. Among these pigments, zinc oxide and titanium oxide are preferable because they have high charge transporting ability and are effective for thickening. The surface of these pigments may be surface-treated with an organic titanium compound such as a titanate coupling agent, an aluminum chelate compound or an aluminum coupling agent for the purpose of improving dispersibility or adjusting the energy level, in particular vinyltrichlorosilane. , Vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris-2-methoxyethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ -Chloropropyltrimethoxysilane, γ-2-aminoethylaminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, β-3,4-epoxysilane It is preferable to treat with a silane coupling agent such as cyclohexyl trimethoxysilane.

As a method for mixing / dispersing the organic or inorganic semiconductive fine particles, a method using a ball mill, a roll mill, a sand mill, an attritor, an ultrasonic wave, or the like is applied. Mixing / dispersing is carried out in an organic solvent. As the organic solvent, an organic metal compound or resin is dissolved, and no gelation or aggregation occurs when organic / inorganic semiconductive fine particles are mixed / dispersed. Anything can be used.
For example, methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene Ordinary organic solvents such as toluene can be used alone or in admixture of two or more.

If desired, an undercoat layer can be formed between the conductive substrate and the photosensitive layer.
Materials used include zirconium chelate compounds, zirconium alkoxide compounds, organic zirconium compounds such as zirconium coupling agents, titanium chelate compounds, titanium alkoxide compounds, organic titanium compounds such as titanate coupling agents, aluminum chelate compounds, aluminum coupling agents, etc. In addition to organic aluminum compounds, antimony alkoxide compounds, germanium alkoxide compounds, indium alkoxide compounds, indium chelate compounds, manganese alkoxide compounds, manganese chelate compounds, tin alkoxide compounds, tin chelate compounds, aluminum silicon alkoxide compounds, aluminum titanium alkoxide compounds, aluminum Zirconium alkoxide compounds, etc. Machine metal compounds. In particular, organozirconium compounds, organotitanium compounds, and organoaluminum compounds are preferably used because of their low residual potential and good electrophotographic characteristics.

In addition, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris-2-methoxyethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyl Triethoxysilane, γ-chloropropyltrimethoxysilane, γ-2-aminoethylaminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, β-3,4-epoxycyclohexyltrimethoxy It can be used by containing a silane coupling agent such as silane.
Furthermore, polyvinyl alcohol, polyvinyl methyl ether, poly-N-vinyl imidazole, polyethylene oxide, ethyl cellulose, methyl cellulose, ethylene-acrylic acid copolymer, polyamide, polyimide, casein, gelatin, polyethylene, polyester, conventionally used for the undercoat layer Further, known binder resins such as phenol resin, vinyl chloride-vinyl acetate copolymer, epoxy resin, polyvinyl pyrrolidone, polyvinyl pyridine, polyurethane, polyglutamic acid, and polyacrylic acid can also be used. These mixing ratios can be appropriately set as necessary.

Further, an electron transporting pigment may be mixed / dispersed in the undercoat layer. Examples of the electron transport pigment include organic pigments such as perylene pigments, bisbenzimidazole perylene pigments, polycyclic quinone pigments, indigo pigments, quinacridone pigments described in JP-A-47-30330, cyano groups, nitro groups, Examples thereof include organic pigments such as bisazo pigments and phthalocyanine pigments having electron-withdrawing substituents such as nitroso groups and halogen atoms, and inorganic pigments such as zinc oxide and titanium oxide. Among these pigments, perylene pigments, bisbenzimidazole perylene pigments and polycyclic quinone pigments, zinc oxide, and titanium oxide are preferably used because of their high electron mobility. Further, the surface of these pigments may be surface-treated with the above-mentioned coupling agent or binder for the purpose of controlling dispersibility and charge transport property.
As a method for mixing / dispersing the electron transporting pigment, a conventional method using a ball mill, a roll mill, a sand mill, an attritor, an ultrasonic wave, or the like is applied. Mixing / dispersing is carried out in an organic solvent, as long as the organic solvent dissolves an organometallic compound or resin and does not cause gelation or aggregation when an electron transporting pigment is mixed / dispersed. Anything can be used. For example, methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene Ordinary organic solvents such as toluene can be used alone or in admixture of two or more. The thickness of the undercoat layer is generally 0.1 to 30 μm, preferably 0.2 to 25 μm.

  In addition, as the coating method used when the undercoat layer is provided, conventional methods such as a blade coating method, a Meyer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, and a curtain coating method are used. Can be used. The coated layer is dried to obtain an undercoat layer. Usually, the drying is performed at a temperature at which the solvent can be evaporated to form a film. In particular, a conductive substrate that has been subjected to an acid solution treatment or a boehmite treatment is preferably formed with an undercoat layer because the defect concealing power of the conductive substrate tends to be insufficient.

  Examples of the charge generation material used in the charge generation layer include azo pigments such as bisazo and trisazo, condensed aromatic pigments such as dibromoanthanthrone, perylene pigments, pyrrolopyrrole pigments, organic pigments such as phthalocyanine pigments, trigonal selenium, Although all known ones such as inorganic pigments such as zinc oxide can be used, inorganic pigments are particularly preferred when using an exposure wavelength of 380 nm to 500 nm, and metals and non-organic pigments are used when using an exposure wavelength of 700 nm to 800 nm. Metal phthalocyanine pigments are preferred. Among these, hydroxygallium phthalocyanine disclosed in JP-A-5-263007 and JP-A-5-279591, chlorogallium phthalocyanine disclosed in JP-A-5-98181, JP-A-5-140472 and Particularly preferred are dichlorotin phthalocyanine disclosed in JP-A-5-140473, titanyl phthalocyanine disclosed in JP-A-4-189873 and JP-A-5-43813.

The binder resin can be selected from a wide range of insulating resins. It can also be selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene, polyvinylpyrene, and polysilane. Preferred binder resins include polyvinyl butyral resin, polyarylate resin (polycondensate of bisphenol A and phthalic acid, etc.), polycarbonate resin, polyester resin, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyamide resin, acrylic resin. Insulating resin such as polyacrylamide resin, polyvinyl pyridine resin, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol resin, polyvinyl pyrrolidone resin can be used, but is not limited thereto. These binder resins can be used alone or in admixture of two or more.
The blending ratio (weight ratio) between the charge generating material and the binder resin is preferably in the range of 10: 1 to 1:10. In addition, as a method for dispersing them, a usual method such as a ball mill dispersion method, an attritor dispersion method, a sand mill dispersion method, or the like can be used. It is said. In addition, it has been confirmed that the crystal form is not changed from that before dispersion in any of the dispersion methods implemented in the present invention. Further, at the time of this dispersion, it is effective to make the particles have a particle size of 0.5 μm or less, preferably 0.3 μm or less, more preferably 0.15 μm or less.

Moreover, as a solvent used for these dispersions, methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran Ordinary organic solvents such as methylene chloride, chloroform, chlorobenzene and toluene can be used alone or in admixture of two or more.
The thickness of the charge generation layer used in the present invention is generally 0.1 to 5 μm, preferably 0.2 to 2.0 μm. In addition, as a coating method used when the charge generation layer is provided, usual methods such as a blade coating method, a Meyer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, and a curtain coating method are used. Can be used.

As the charge transport layer of the photoreceptor, those formed by a known technique can be used. These charge transport layers are formed containing a charge transport material and a binder resin, or are formed containing a polymer charge transport material.
Charge transport materials include quinone compounds such as p-benzoquinone, chloranil, bromanyl, anthraquinone, tetracyanoquinodimethane compounds, fluorenone compounds such as 2,4,7-trinitrofluorenone, xanthone compounds, benzophenone compounds , Electron transport compounds such as cyanovinyl compounds and ethylene compounds, triarylamine compounds, benzidine compounds, arylalkane compounds, aryl-substituted ethylene compounds, stilbene compounds, anthracene compounds, hydrazone compounds, etc. Examples thereof include pore-transporting compounds. These charge transport materials can be used alone or in combination of two or more, but are not limited thereto. In addition, these charge transport materials can be used alone or in combination of two or more, but those having the following structure are preferred from the viewpoint of mobility.

(In the formula, R ¹⁴ represents a hydrogen atom or a methyl group, and n represents 1 or 2. Ar ₆ and Ar ₇ represent a substituted or unsubstituted aryl group, or —C (R ¹⁸ ) ═C (R ¹⁹ ) (R ²⁰ ), —CH═CH—CH═C (Ar) ₂ , wherein R ¹⁸ , R ¹⁹ and R ²⁰ are a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl Ar represents a substituted or unsubstituted aryl group, including a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or carbon A substituted amino group substituted with an alkyl group having a number in the range of 1 to 3 is shown.)

(Wherein R ¹⁵ and R ^{15 ′} may be the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. R ¹⁶ , R ^{16 ′} , R ¹⁷ and R ^{17 ′} may be the same or different, and an amino group substituted with a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an alkyl group having 1 to 2 carbon atoms. Represents a substituted or unsubstituted aryl group, or —C (R ¹⁸ ) ═C (R ¹⁹ ) (R ²⁰ ), —CH═CH—CH═C (Ar) ₂ , R ¹⁸ , R ¹⁹ , R ²⁰ represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, Ar represents a substituted or unsubstituted aryl group, and m and n are integers of 0 to 2.)

(In the formula, R ₂₁ represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a substituted or unsubstituted aryl group, or —CH═CH—CH═C (Ar) ₂ . Ar represents a substituted or unsubstituted aryl group, and R ₂₂ and R ₂₃ may be the same or different, and may be a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. Group, an amino group substituted with an alkyl group having 1 to 2 carbon atoms, or a substituted or unsubstituted aryl group.)

  Further, the binder resin used for the charge transport layer is polycarbonate resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer, vinylidene chloride- Acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, poly-N- Vinyl carbazole, polysilane, and polymer charge transport materials such as polyester polymer charge transport materials disclosed in JP-A-8-176293 and JP-A-8-208820 can also be used. These binder resins can be used alone or in admixture of two or more. The blending ratio (weight ratio) between the charge transport material and the binder resin is preferably 10: 1 to 1: 5.

  A polymer charge transport material can also be used alone. As the polymer charge transporting material, known materials having charge transporting properties such as poly-N-vinylcarbazole and polysilane can be used. In particular, polyester polymer charge transport materials disclosed in JP-A-8-176293 and JP-A-8-208820 have a high charge transporting property and are particularly preferable. The polymer charge transport material alone can be used as the charge transport layer, but it may be formed by mixing with the binder resin.

The thickness of the charge transport layer used in the present invention is generally 5 to 50 μm, preferably 10 to 30 μm. As a coating method, a normal method such as a blade coating method, a Meyer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, or a curtain coating method can be used.
Solvents used when providing the charge transport layer include aromatic hydrocarbons such as benzene, toluene, xylene and chlorobenzene, ketones such as acetone and 2-butanone, and halogenated fats such as methylene chloride, chloroform and ethylene chloride. Ordinary organic solvents such as aromatic hydrocarbons, cyclic ethers such as tetrahydrofuran and ethyl ether, or straight-chain ethers can be used alone or in admixture of two or more.

  Additives such as antioxidants, light stabilizers, and heat stabilizers are added to the photosensitive layer to prevent photoconductor deterioration due to ozone, oxidizing gas, or light or heat generated in the copying machine. can do. For example, examples of the antioxidant include hindered phenol, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirochroman, spiroidanone and derivatives thereof, organic sulfur compounds, and organic phosphorus compounds. Examples of the light stabilizer include derivatives such as benzophenone, benzotriazole, dithiocarbamate, and tetramethylpiperidine. In addition, at least one kind of electron accepting substance can be contained for the purpose of improving sensitivity, reducing residual potential, and reducing fatigue during repeated use.

Examples of the electron acceptor usable in the photoconductor according to the present invention include succinic anhydride, maleic anhydride, dibromomaleic anhydride, phthalic anhydride, tetrabromophthalic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m-dinitrobenzene, chloranil, dinitroanthraquinone, trinitrofluorenone, picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, phthalic acid and the like, and compounds represented by the general formula (I) described later Can give. Of these, benzene derivatives having electron-withdrawing substituents such as fluorenone, quinone and Cl, CN, NO ₂ are particularly preferred.

  As the protective layer according to the present invention, a conductive resin dispersed in a binder resin, a lubricating charge such as a fluororesin and an acrylic resin dispersed in a normal charge transport layer material, silicon, acrylic, etc. A hard coating agent can be used, but those having a crosslinked structure are preferred from the viewpoint of film strength.

  Various materials can be used for forming the crosslinked structure, but phenolic resins, siloxane resins, urethane resins, epoxy resins, and the like are preferable in terms of characteristics, and those made of phenolic resins or siloxane-based resins are particularly preferable. In addition to the resin having a crosslinked structure, the protective layer includes a binder resin not having a crosslinked structure, conductive fine particles, and lubricating fine particles made of a fluororesin or an acrylic resin, if necessary. In forming the outermost surface layer, a hard coat agent such as silicon or acrylic can be used as necessary. The details of the method for forming the outermost surface layer will be described later. For the formation of the outermost surface layer, a solution for forming the outermost surface layer containing at least a precursor constituting a resin having a crosslinked structure is used.

  Furthermore, from the viewpoint of electrical characteristics, image quality maintenance, etc., it is preferable that the outermost surface layer (protective layer) contains a structural unit having a charge transport ability and a resin having a crosslinked structure.

  The structural unit having a charge transporting ability that includes a structural unit having such a charge transporting ability and constituting a resin having a crosslinked structure is a phenol derivative or siloxane-based resin having a methylol group as a resin having a crosslinked structure, a hydroxyl group, More preferably, it contains a charge transport material having at least one selected from a carboxyl group, an alkoxysilyl group, an epoxy group, a thiol group and an amino group. Furthermore, since the infrared absorption spectrum (IR spectrum) of the phenol derivative-containing layer as the protective layer satisfies the condition represented by the following formula, the electrical characteristics are excellent, and high image quality can be achieved.

        (P2 / P1) ≦ 0.2

Wherein, P1 is the absorbance of the maximum absorption peaks at 1560cm ^-1 ~1640cm ^-1, P2 represents the absorbance of the maximum absorption peaks at 1645cm ^-1 ~1700cm ^-1. ]

The reason why the above-described effect is obtained by the above formula is not necessarily clear, but the present inventors infer as follows.
That is, in the process of forming a coating film using a phenol derivative having a methylol group, it is considered that a part of the methylol group of the phenol derivative becomes an oxide such as a formyl group. Such an oxide such as a formyl group is considered to act as a carrier trap that hinders charge transport in the photoconductor, thereby reducing the electrical characteristics of the photoconductor. Here, in the infrared absorption spectrum, the maximum absorption peaks at 1560cm ^-1 ~1640cm ^-1 (P1) corresponds to the aromatic C-C stretching vibration of a phenol derivative. The maximum absorption peaks at 1645cm ^-1 ~1700cm ^-1 (P2) is thought to be derived from the oxide such as a formyl group.

That is, it is considered that a photoconductor having a small absorbance ratio (P2 / P1) has few oxides such as formyl groups in the photoconductor and is excellent in carrier transportability. The photoreceptor according to the present invention uses the above-mentioned specific material and has an absorbance ratio (P2 / P1) of 0.2 or less. Therefore, it is considered that the photoreceptor has excellent electrical characteristics and high image quality. The photoreceptor according to the present invention is excellent in mechanical strength as well as electrical characteristics, and this is also considered to be a factor in achieving high image quality.
The absorbance ratio (P2 / P1) is preferably 0.18 or less, and more preferably 0.17 or less. When the absorbance ratio (P2 / P1) exceeds 0.2, the carrier transportability is lowered, the electrical characteristics of the photoreceptor are insufficient, and the image quality is lowered.

  Examples of the phenol derivative having a methylol group include monomers of monomethylolphenols, dimethylolphenols or trimethylolphenols, mixtures thereof, oligomers thereof, or mixtures of these monomers and oligomers. Such phenol derivatives having a methylol group include resorcin, bisphenol, etc., substituted phenols containing one hydroxyl group such as phenol, cresol, xylenol, paraalkylphenol, paraphenylphenol, and two hydroxyl groups such as catechol, resorcinol, hydroquinone, etc. It is obtained by reacting a compound having a phenol structure, such as substituted phenols, bisphenol A, bisphenol Z, and the like having a phenol structure with formaldehyde, paraformaldehyde, etc. in the presence of an acid catalyst or an alkali catalyst, Generally what is marketed as a phenol resin can also be used. In the present specification, a relatively large molecule having about 2 to 20 repeating molecular structural units is referred to as an oligomer, and a molecule smaller than that is referred to as a monomer.

As the acid catalyst, sulfuric acid, paratoluenesulfonic acid, phosphoric acid and the like are used. As the alkali catalyst, hydroxides or amine catalysts of alkali metals and alkaline earth metals such as NaOH, KOH, Ca (OH) ₂ and Ba (OH) ₂ are used.
Examples of the amine catalyst include, but are not limited to, ammonia, hexamethylenetetramine, trimethylamine, triethylamine, and triethanolamine. When a basic catalyst is used, the carrier is remarkably trapped by the remaining catalyst, and the electrophotographic characteristics tend to be deteriorated. Therefore, it is preferable to inactivate or remove by neutralizing with an acid or contacting with an adsorbent such as silica gel or an ion exchange resin.
Moreover, as a phenol derivative which has a methylol group, a phenol resin is preferable and a resol type phenol resin is more preferable.

  As the charge transport material having at least one selected from a hydroxyl group, a carboxyl group, an alkoxysilyl group, an epoxy group, a thiol group and an amino group, compounds represented by the following general formula (I), (II) or (III) It is preferable that

_{^{F - [(X 1) m1}} - (R 1) m2 -Y] m3 (I)

In the above formula (I), F is an organic group derived from a compound having a hole transporting ability, X ¹ is an oxygen atom or a sulfur atom, R ¹ is an alkylene group (the number of carbon atoms is preferably 1 to 15, preferably 1 10 is more preferable), Y represents a hydroxyl group, a carboxyl group (—COOH), a thiol group (—SH) or an amino group (—NH ₂ ), m1 and m2 each independently represents 0 or 1, m3 represents An integer of 1 to 4 is shown.

_{^{F - [(X 2) n1}} - (R 2) n2 - (Z) n3 G] n4 (II)

In the above formula (II), F represents an organic group derived from a compound having a hole transporting ability, X ² represents an oxygen atom or a sulfur atom, R ² represents an alkylene group (preferably having 1 to 15 carbon atoms, 1 10 is more preferable), Z is an alkylene group, oxygen atom, sulfur atom, NH or COO, G is an epoxy group, n1, n2 and n3 are each independently 0 or 1, n4 is 1-4 Indicates an integer.

F- [D-Si (R ³ ) _(3-a) Q _a ] _b (III)

In formula (III), F represents an organic group derived from a compound having a hole transporting ability, D represents a divalent group having flexibility, R ³ represents a hydrogen atom, a substituted or unsubstituted alkyl group ( The number of carbon atoms is preferably 1-15, more preferably 1-10, or a substituted or unsubstituted aryl group (carbon number is preferably 6-20, more preferably 6-15), and Q is a hydrolyzable group. A represents an integer of 1 to 3, and b represents an integer of 1 to 4.

In addition, as the divalent group D having flexibility, specifically, a site of F for imparting photoelectric characteristics, a substituted silicon group contributing to the construction of a three-dimensional inorganic glassy network, It is a divalent group that plays a role in linking. In addition, D represents an organic group structure that imparts moderate flexibility to the portion of the inorganic glassy network that is hard but brittle, and plays a role of improving mechanical toughness as a film. Specific examples _{D, -CαH 2 α -, -} CβH 2 β -2 -, - CγH 2 γ -4 - 2 divalent hydrocarbon group (here represented by, alpha is an integer from 1 to 15 , Β represents an integer of 2 to 15, and γ represents an integer of 3 to 15), —COO—, —S—, —O—, —CH ₂ —C ₆ H ₄ —, —N═CH—, -(C ₆ H ₄ )-(C ₆ H ₄ )-and a characteristic group having a structure in which these characteristic groups are arbitrarily combined, and further, constituent atoms of these characteristic groups are substituted with other substituents In the case of a characteristic group having a structure in which characteristic groups are arbitrarily combined, a combination containing at least carbon atoms is preferable. The hydrolyzable group Q is preferably an alkoxy group, more preferably an alkoxy group having 1 to 15 carbon atoms.

  As the organic group F derived from the compound having a hole transport ability in the compounds represented by the general formulas (I) to (III), a compound represented by the following general formula (VI) is preferable.

Here, in the formula (VI), Ar ¹ , Ar ² , Ar ³ and Ar ⁴ each independently represent a substituted or unsubstituted aryl group, and Ar ⁵ represents a substituted or unsubstituted aryl group or arylene group. ^{1 to} 4 of Ar ^{1 to} Ar ⁵ are-[(X ¹ ) _m1- (R ¹ ) _m2 -Y],-[(X _{^{2) n1 - (R 2)}} n2 - (Z) n3 G], or - has a portion with a bond represented by ^{[D-Si (R 3)} (3-a) Q a].

  In addition, conductive particles may be added to the protective layer in order to lower the residual potential. Examples of the conductive particles include metals, metal oxides, and carbon black. Among these, metals or metal oxides are more preferable. Examples of the metal include aluminum, zinc, copper, chromium, nickel, silver, and stainless steel, or those obtained by depositing these metals on the surface of plastic particles. Examples of the metal oxide include zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, tin-doped indium oxide, antimony and tantalum-doped tin oxide, and antimony-doped zirconium oxide. It is done. These can be used alone or in combination of two or more. When two or more types are used in combination, they may be simply mixed, or may be in the form of a solid solution or fusion. From the viewpoint of the transparency of the protective layer, the volume average particle size of the conductive particles is preferably 0.3 μm or less, and particularly preferably 0.1 μm or less.

  In addition, a compound represented by the following general formula (VII-1) can also be added to the protective layer in order to control various physical properties such as strength and film resistance of the protective layer.

Si (R ³⁰ ) _(4-c) Q _c (VII-1)

In the above formula (VII-1), R ³⁰ represents a hydrogen atom, an alkyl group or a substituted or unsubstituted aryl group, Q represents a hydrolyzable group, and c represents an integer of 1 to 4.

Specific examples of the compound represented by the general formula (VII-1) include the following silane coupling agents. Examples of silane coupling agents include tetrafunctional silanes such as tetramethoxysilane and tetraethoxysilane (c = 4); methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, methyltrimethoxyethoxysilane, vinyltri Methoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxy Silane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, (tridecafluoro-1,1,2,2-tetrahydrooctyl L) Triethoxysilane, (3,3,3-trifluoropropyl) trimethoxysilane, 3- (heptafluoroisopropoxy) propyltriethoxysilane, 1H, 1H, 2H, 2H-perfluoroalkyltriethoxysilane, 1H , 1H, 2H, 2H-perfluorodecyltriethoxysilane, trifunctional alkoxysilane such as 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane (c = 3); dimethyldimethoxysilane, diphenyldimethoxysilane, methyl And bifunctional alkoxysilanes such as phenyldimethoxysilane (c = 2); monofunctional alkoxysilanes such as trimethylmethoxysilane (c = 1), and the like. Trifunctional and tetrafunctional alkoxysilanes are preferable for improving the strength of the film, and monofunctional and bifunctional alkoxysilanes are preferable for improving the flexibility and film formability.

  In addition, a silicon-based hard coat agent produced mainly from these coupling agents can also be used. Commercially available hard coat agents include KP-85, X-40-9740, X-40-2239 (manufactured by Shin-Etsu Silicone), and AY42-440, AY42-441, AY49-208 (manufactured by Toray Dow Corning). Etc.) can be used.

  In order to increase the strength of the protective layer, it is also preferable to use a compound having two or more silicon atoms as shown in the general formula (VII-2).

B- (Si (R ³¹ ) _(3-d) Q _d ) ₂ (VII-2)

In the above formula (VII-2), B represents a divalent organic group, R ³¹ represents a hydrogen atom, an alkyl group, or a substituted or unsubstituted aryl group, Q represents a hydrolyzable group, and d represents 1 to 3. Indicates an integer.

  The protective layer has a cyclic compound having a repeating structural unit represented by the following general formula (VII-3) for extending pot life, controlling film characteristics, reducing torque, and improving the uniformity of the coating film surface, or Derivatives from the compounds can also be included.

In the above formula (VII-3), A ¹ and A ² each independently represent a monovalent organic group.

  Commercially available cyclic siloxane can be mentioned as a cyclic compound which has a repeating structural unit shown by general formula (VII-3). Specifically, cyclic dimethylcyclosiloxanes such as hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, 1,3,5-trimethyl-1,3,5- Triphenylcyclotrisiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetraphenylcyclotetrasiloxane, 1,3,5,7,9-pentamethyl-1,3,5,7 , 9-pentaphenylcyclopentasiloxane and other cyclic methylphenylcyclosiloxanes, hexaphenylcyclotrisiloxane and other cyclic phenylcyclosiloxanes, and 3- (3,3,3-trifluoropropyl) methylcyclotrisiloxane and other fluorine Atom-containing cyclosiloxanes, methylhydrosiloxa Mixture, pentamethylcyclopentasiloxane, mention may be made of phenyl hydrosilyl group-containing cyclosiloxanes of hydrocyclosiloxane like, cyclic siloxanes and vinyl group-containing cyclosiloxanes such as penta vinyl pentamethylcyclopentasiloxane like. These cyclic siloxane compounds may be used alone or in combination of two or more.

  Furthermore, various fine particles can be added in order to control the contamination resistance adhesion, lubricity, hardness, etc. of the photoreceptor surface. They can be used alone or in combination of two or more.

Examples of the fine particles include silicon atom-containing fine particles. The silicon atom-containing fine particles are fine particles containing silicon as a constituent element, and specific examples include colloidal silica and silicone fine particles. The colloidal silica used as the silicon atom-containing fine particles preferably has a volume average particle diameter of 1 to 100 nm, more preferably 10 to 30 nm, in an acidic or alkaline aqueous dispersion, or an organic solvent such as alcohol, ketone or ester. It is selected from those dispersed in, and commercially available products can be used. The solid content of colloidal silica in the protective layer is not particularly limited, but preferably 0.1 to 50 mass based on the total solid content of the protective layer in terms of film formability, electrical properties, and strength. %, More preferably 0.1 to 30% by mass.
The silicone fine particles used as the silicon atom-containing fine particles are spherical and preferably have a volume average particle size of 1 to 500 nm, more preferably 10 to 100 nm, and are selected from silicone resin particles, silicone rubber particles, and silicone surface-treated silica particles. A commercially available product can be used.

  Silicone fine particles are small particles that are chemically inert and excellent in dispersibility in resins, and because the content required to obtain sufficient properties is low, photosensitivity can be achieved without inhibiting the crosslinking reaction. The surface properties of the body can be improved. That is, it is possible to improve the lubricity and water repellency of the surface of the photoreceptor while being uniformly incorporated into a strong cross-linked structure, and maintain good wear resistance and contamination resistance adhesion over a long period of time. The content of the silicone fine particles in the protective layer is preferably in the range of 0.1 to 30% by mass, more preferably in the range of 0.5 to 10% by mass, based on the total solid content of the protective layer.

Other fine particles include fluorine-based fine particles such as ethylene tetrafluoride, trifluoride ethylene, propylene hexafluoride, vinyl fluoride, vinylidene fluoride, and the 8th Polymer Materials Forum Lecture Proceedings p89. Fine particles made of a resin obtained by copolymerizing a fluororesin and a monomer having a hydroxyl group, ZnO—Al ₂ O ₃ , SnO ₂ —Sb ₂ O ₃ , In ₂ O ₃ —SnO ₂ , ZnO—TiO ₂ , ZnO Examples thereof include semiconductive metal oxides such as —TiO ₂ , MgO—Al ₂ O ₃ , FeO—TiO ₂ , TiO ₂ , SnO ₂ , In ₂ O ₃ , ZnO, and MgO. For the same purpose, an oil such as silicone oil can be added.

  Examples of the silicone oil include silicone oils such as dimethylpolysiloxane, diphenylpolysiloxane, and phenylmethylsiloxane, amino-modified polysiloxane, epoxy-modified polysiloxane, carboxyl-modified polysiloxane, carbinol-modified polysiloxane, methacryl-modified polysiloxane, and mercapto. Examples include reactive silicone oils such as modified polysiloxanes and phenol-modified polysiloxanes. These may be added in advance to the protective layer-forming coating solution, or may be impregnated under reduced pressure or increased pressure after producing the photoreceptor.

  In addition, additives such as plasticizers, surface modifiers, antioxidants, and photodegradation inhibitors can also be used. Examples of the plasticizer include biphenyl, biphenyl chloride, terphenyl, dibutyl phthalate, diethylene glycol phthalate, dioctyl phthalate, triphenyl phosphate, methyl naphthalene, benzophenone, chlorinated paraffin, polypropylene, polystyrene, and various fluorohydrocarbons. An antioxidant having a hindered phenol, hindered amine, thioether or phosphite partial structure can be added to the protective layer, which is effective in improving the potential stability and image quality when the environment changes.

  Examples of the antioxidant include the following compounds. For example, hindered phenols include “Sumilizer BHT-R”, “Sumilizer MDP-S”, “Sumilizer BBM-S”, “Sumizer WX-R”, “Sumizer NW”, “Sumizer BP-76”, “ Sumilizer BP-101 "," Sumilizer GA-80 "," Sumilizer GM "," Sumilizer GS "or more manufactured by Sumitomo Chemical Co., Ltd.," IRGANOX1010 "," IRGANOX1035 "," IRGANOX1076 "," IRGANOX1098 "," IRGANOX1098 "," 114 " ”,“ IRGANOX1222 ”,“ IRGANOX1330 ”,“ IRGANOX1425WL ”,“ IRGANOX1 20L "," IRGANOX 245 "," IRGANOX 259 "," IRGANOX 3114 "," IRGANOX 3790 "," IRGANOX 5057 "," IRGANOX 565 "or more, manufactured by Ciba Specialty Chemicals," ADK STAB AO-20 "," ADK STAB AO-30 "," ADEKA STAB " "AO-40", "ADK STAB AO-50", "ADK STAB AO-60", "ADK STAB AO-70", "ADK STAB AO-80", "ADK STAB AO-330" or more manufactured by Asahi Denka. As the hindered amine system, “Sanol LS2626”, “Sanol LS765”, “Sanol LS770”, “Sanol LS744” or more manufactured by Sankyo Lifetech Co., Ltd., “Tinubin 144”, “Tinubin 622LD”, “Mark LA57”, “ “Mark LA67”, “Mark LA62”, “Mark LA68”, “Mark LA63”, “Smilizer TPS”, “Smilizer TP-D” for thioethers, “Mark 2112”, “Mark PEP” for phosphites -8 "," Mark PEP.24G "," Mark PEP.36 "," Mark 329K "," Mark HP.10 ", and hindered phenols and hindered amine antioxidants are particularly preferable. Furthermore, these may be modified with a substituent such as an alkoxysilyl group capable of undergoing a crosslinking reaction with the material forming the crosslinked film.

  For the protective layer, polyvinyl butyral resin, polyarylate resin (polycondensate of bisphenol A and phthalic acid, etc.), polycarbonate resin, polyester resin, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyamide resin, acrylic resin Insulating resin such as polyacrylamide resin, polyvinyl pyridine resin, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol resin, polyvinyl pyrrolidone resin may be contained. In this case, the insulating resin can be added at a desired ratio, thereby suppressing adhesion with the charge transport layer, coating film defects due to heat shrinkage and repellency, and the like.

  The protective layer is formed by applying a protective layer-forming coating solution containing the above-described constituent materials onto the charge transport layer and curing it.

  Since the protective layer is formed using the above-described charge transport material, it is preferable to add a catalyst to the protective layer forming coating solution or to use the catalyst when preparing the protective layer forming coating solution. Catalysts used include inorganic acids such as hydrochloric acid, acetic acid, phosphoric acid and sulfuric acid, organic acids such as formic acid, propionic acid, oxalic acid, paratoluenesulfonic acid, benzoic acid, phthalic acid and maleic acid, potassium hydroxide, water An alkali catalyst such as sodium oxide, calcium hydroxide, ammonia, triethylamine, or a solid catalyst insoluble in the system can also be used.

  In addition, in order to remove the catalyst at the time of synthesis from a phenol derivative having a methylol group, the phenol derivative is dissolved in a suitable solvent such as methanol, ethanol, toluene, ethyl acetate, washed with water, reprecipitation using a poor solvent, etc. It is preferable to perform the above treatment or to perform treatment using an ion exchange resin or an inorganic solid.

  For example, as an ion exchange resin, Amberlite 15, Amberlite 200C, Amberlyst 15E (above, manufactured by Rohm and Haas); Dowex MWC-1-H, Dowex 88, Dowex HCR-W2 (above Levacit SPC-108, Levacit SPC-118 (above, Bayer); Diaion RCP-150H (Mitsubishi Kasei); Sumikaion KC-470, Duolite C26-C, Duolite C-433, Duolite-464 (above, manufactured by Sumitomo Chemical Co., Ltd.); Cation exchange resins such as Nafion-H (DuPont); Amberlite IRA-400, Amberlite IRA-45 (above, Rohm and Anion exchange resins such as (made by Haas) are listed.

Further, as the inorganic solid, an inorganic solid in which a group containing a protonic acid group such as Zr (O ₃ PCH ₂ CH ₂ SO ₃ H) ₂ or Th (O ₃ PCH ₂ CH ₂ COOH) ₂ is bonded to the surface. A polyorganosiloxane containing a protonic acid group such as a polyorganosiloxane having a sulfonic acid group; a heteropolyacid such as cobalt tungstic acid or phosphomolybdic acid; an isopolyacid such as niobic acid, tantalic acid or molybdic acid; silica gel, alumina, Single metal oxides such as chromia, zirconia, CaO, MgO; complex metal oxides such as silica-alumina, silica-magnesia, silica-zirconia, zeolites; clay minerals such as acid clay, activated clay, montmorillonite, and kaolinite Metal sulfates such as LiSO ₄ and MgSO ₄ ; gold such as zirconia phosphate and lanthanum phosphate Metal nitrate; LiNO ₃ , metal nitrate such as Mn (NO ₃ ) ₂ ; Group containing amino group such as solid obtained by reacting aminopropyltriethoxysilane on silica gel is bonded to the surface Inorganic solids: Polyorganosiloxanes containing amino groups such as amino-modified silicone resins.

  For the coating liquid for forming the protective layer, alcohols such as methanol, ethanol, propanol and butanol; ketones such as acetone and methyl ethyl ketone; tetrahydrofuran; ethers such as diethyl ether and dioxane; Can be used. In order to apply the dip coating method generally used for the production of the photoreceptor, an alcohol solvent, a ketone solvent, or a mixed solvent thereof is preferable. In addition, the boiling point of the solvent used is preferably 50 to 150 ° C., and these can be arbitrarily mixed and used.

  In addition, since an alcohol solvent, a ketone solvent, or a mixed solvent thereof is preferable as the solvent, the charge transport material used for forming the protective layer to be used may be soluble in these solvents. preferable.

  The amount of the solvent can be set arbitrarily, but if the amount is too small, the constituent materials are likely to be precipitated. Therefore, the amount of the solvent is preferably 0.5 to 30 mass with respect to the total 1 mass part of the solid content contained in the coating liquid for forming the protective layer. Part, more preferably 1 to 20 parts by mass.

  Coating methods for forming a protective layer using a coating solution for forming a protective layer include blade coating, wire bar coating, spray coating, dip coating, bead coating, air knife coating, and curtain coating. A usual method such as can be used. However, when a required film thickness cannot be obtained by a single application, the necessary film thickness can be obtained by applying a plurality of times. In addition, when performing the multiple application | coating several times, a heat processing may be performed every time of application | coating, and may be after carrying out multiple application | coating several times.

  After applying the coating liquid for forming the protective layer on the charge transport layer, a curing process is performed. Usually, during the curing treatment, the curing temperature is higher and the curing time is longer in order to promote the crosslinking reaction of the phenol derivative and increase the mechanical strength of the protective layer. However, in such a case, the absorbance ratio (P2 / P1) tends to exceed 0.2, and the electrical characteristics are significantly deteriorated. Therefore, it is preferable to control with a curing temperature, a curing time, a crosslinking atmosphere or a curing catalyst so that the IR spectrum of the protective layer satisfies the above conditions.

That is, in order for the IR spectrum of the protective layer to satisfy the condition represented by the above formula, the curing temperature during the curing treatment is preferably 100 to 170 ° C, more preferably 100 to 150 ° C, and more preferably 100 to 140 ° C. Further preferred. The curing time is preferably 30 minutes to 2 hours, more preferably 30 minutes to 1 hour.
Further, as an atmosphere for performing the curing treatment (crosslinking reaction), the absorbance ratio (P2 / P1) is reduced under a so-called oxidation inert gas atmosphere (inert gas atmosphere) such as nitrogen, helium, and argon. It is effective. When the crosslinking reaction is performed in an inert gas atmosphere, the curing temperature can be set higher than in an air atmosphere (oxygen-containing atmosphere), and the curing temperature is 100 to 160 ° C. (preferably 110 to 150 ° C.). Is possible. The curing time can be 30 minutes to 2 hours (preferably 30 minutes to 1 hour). In addition, in the compound represented by the general formula (I), when the site represented by (— (X ¹ ) _m1 — (R ¹ ) _m2 —Y) is —CH ₂ —OH, the influence of the electrical characteristics due to the curing temperature is the highest. Is apt to be large and is sensitive to oxidation. Therefore, it is preferable to carry out the curing treatment in the above preferred temperature range.

  Furthermore, it is preferable to use a curing catalyst during the curing treatment. Examples of the curing catalyst include bissulfonyldiazomethanes such as bis (isopropylsulfonyl) diazomethane, bissulfonylmethanes such as methylsulfonyl p-toluenesulfonylmethane, and sulfonylcarbonyldiazomethanes such as cyclohexylsulfonylcyclohexylcarbonyldiazomethane, 2 -Sulfonylcarbonyl alkanes such as methyl-2- (4-methylphenylsulfonyl) propiophenone, nitrobenzyl sulfonates such as 2-nitrobenzyl p-toluenesulfonate, alkyl and aryl sulfonates such as pyrogallol trismethanesulfonate Benzoin sulfonates such as benzoin tosylate, such as N- (trifluoromethylsulfonyloxy) phthalimide N-sulfonyloxyimides, pyridones such as (4-fluorobenzenesulfonyloxy) -3,4,6-trimethyl-2-pyridone, 2,2,2-trifluoro-1-trifluoromethyl-1- Photoacid generators such as (3-vinylphenyl) -ethyl-4-chlorobenzenesulfonate, onium salts such as triphenylsulfonium methanesulfonate, diphenyliodonium trifluoromethanesulfonate, protonic acids or Lewis acids And a mixture of Lewis acid and trialkyl phosphate, sulfonate esters, phosphate esters, onium compounds, carboxylic anhydride compounds, and the like.

Compounds obtained by neutralizing a protonic acid or Lewis acid with a Lewis base include halogenocarboxylic acids, sulfonic acids, sulfuric acid monoesters, phosphoric acid mono- and diesters, polyphosphoric acid esters, boric acid mono- and diesters, and the like. Various amines such as monoethylamine, triethylamine, pyridine, piperidine, aniline, morpholine, cyclohexylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, or trialkylphosphine, triarylphosphine, trialkylphosphite, triaryl Compounds neutralized with phosphite, as well as NureCure 2500X, 4167, X-47-110, 3525, 5225 commercially available as acid-base blocking catalysts (trade name, King Ndasutori Co., Ltd.), and the like. Examples of the compound obtained by neutralizing a Lewis acid with a Lewis base include compounds obtained by neutralizing a Lewis acid such as BF ₃ , FeCl ₃ , SnCl ₄ , AlCl ₃ , ZnCl ₂ with the above Lewis base.

  Examples of the onium compound include triphenylsulfonium methanesulfonate, diphenyliodonium trifluoromethanesulfonate, and the like.

Examples of the carboxylic anhydride compound include acetic anhydride, propionic anhydride, butyric anhydride, isobutyric anhydride, lauric anhydride, oleic anhydride, stearic anhydride, n-caproic anhydride, n-caprylic anhydride, and n-capric anhydride. , Palmitic anhydride, myristic anhydride, trichloroacetic anhydride, dichloroacetic anhydride, monochloroacetic anhydride, trifluoroacetic anhydride, heptafluorobutyric anhydride, and the like.
Specific examples of Lewis acids include, for example, boron trifluoride, aluminum trichloride, titanium chloride, ferric chloride, ferrous chloride, ferric chloride, zinc chloride, zinc bromide, stannous chloride. , Metal halides such as stannic chloride, stannous bromide, stannic bromide, organometallic compounds such as trialkylboron, trialkylaluminum, dialkylaluminum halide, monoalkylaluminum halide, tetraalkyltin , Diisopropoxyethyl acetoacetate aluminum, tris (ethyl acetoacetate) aluminum, tris (acetylacetonato) aluminum, diisopropoxy bis (ethyl acetoacetate) titanium, diisopropoxy bis (acetylacetonato) titanium, tetrakis (N-propylacetoacetate Zirconium, Tetrakis (acetylacetonato) zirconium, Tetrakis (ethylacetoacetate) zirconium, Dibutyl-bis (acetylacetonato) tin, Tris (acetylacetonato) iron, Tris (acetylacetonato) rhodium, Bis (acetyl) Acetonato) zinc, tris (acetylacetonato) cobalt metal chelate compounds, dibutyltin dilaurate, dioctyltin ester malate, magnesium naphthenate, calcium naphthenate, manganese naphthenate, iron naphthenate, cobalt naphthenate, copper naphthenate , Zinc naphthenate, zirconium naphthenate, lead naphthenate, calcium octylate, manganese octylate, iron octylate, cobalt octylate, zinc octylate, zirconium octylate, Tin chill acid, lead octylate, zinc laurate, magnesium stearate, aluminum stearate, calcium stearate, cobalt stearate, zinc stearate, and metal soaps such as stearate lead. These may be used individually by 1 type and may be used in combination of 2 or more type.

  Although the usage-amount of these curing catalysts is not specifically limited, 0.1-20 mass parts is preferable with respect to a total of 100 mass parts of solid content contained in the coating liquid for protective layer formation, and 0.3-10 mass parts is especially preferable. preferable.

When an organic metal compound is used as a catalyst when forming the protective layer, it is preferable to add a polydentate ligand from the viewpoint of pot life and curing efficiency. Examples of such multidentate ligands include, but are not limited to, those shown below and those derived therefrom.
Specifically, β-diketones such as acetylacetone, trifluoroacetylacetone, hexafluoroacetylacetone, and dipivaloylmethylacetone; acetoacetates such as methyl acetoacetate and ethyl acetoacetate; bipyridine and derivatives thereof; glycine and its Derivatives; ethylenediamine and derivatives thereof; 8-oxyquinoline and derivatives thereof; salicylaldehyde and derivatives thereof; catechol and derivatives thereof; bidentate ligands such as 2-oxyazo compounds; diethyltriamine and derivatives thereof; nitrilotriacetic acid and derivatives thereof And tridentate ligands such as ethylenediaminetetraacetic acid (EDTA) and derivatives thereof. In addition to the organic ligands as described above, inorganic ligands such as pyrophosphoric acid and triphosphoric acid can be exemplified. As the multidentate ligand, a bidentate ligand is particularly preferable, and specific examples include a bidentate ligand represented by the following general formula (VII-4) in addition to the above.

In the formula (VII-4), R ³² and R ³³ each independently represent an alkyl group having 1 to 10 carbon atoms, a fluorinated alkyl group, or an alkoxy group having 1 to 10 carbon atoms.

Among the above, as the multidentate ligand, a bidentate ligand represented by the general formula (VII-4) is more preferable, and R ³² and R ^{33 in} the general formula (VII-4) are the same. Is particularly preferred. By making R ³² and R ^{33 the} same, the coordination power of the ligand near room temperature becomes strong, and the coating liquid for forming the protective layer can be further stabilized.

  The compounding amount of the polydentate ligand can be arbitrarily set, but is preferably 0.01 mol or more, more preferably 0.1 mol or more, and still more preferably with respect to 1 mol of the organometallic compound used. 1 mole or more.

Oxygen permeability at 25 ° C. of the protective layer is preferably not more than ^{4 × 10 12 fm / s ·} Pa, more preferably not more than ^{3.5 × 10 12 fm / s ·} Pa, 3 × 10 12 More preferably, it is fm / s · Pa or less.
Here, the oxygen permeation coefficient is a scale representing the ease of oxygen gas permeation of the layer, but it can also be regarded as a substitute characteristic of the physical gap ratio of the layer if the view is changed. In addition, although the absolute value of the transmittance changes if the type of gas changes, there is almost no reversal of the magnitude relationship between the layers serving as specimens. Therefore, the oxygen permeation coefficient may be interpreted as a measure expressing the general ease of gas permeation.
That is, when the oxygen permeation coefficient at 25 ° C. of the protective layer satisfies the above conditions, gas hardly penetrates into the protective layer. Therefore, the penetration of the discharge product generated by the image forming process is suppressed, the deterioration of the compound contained in the protective layer is suppressed, the electrical characteristics can be maintained at a high level, and it is effective for high image quality and long life. It is.

When the protective layer is to be formed so that the absorbance ratio (P2 / P1) of the infrared absorption spectrum satisfies the above conditions, it is necessary to set the curing temperature relatively low in an air atmosphere. Therefore, it is difficult to lower the oxygen transmission coefficient at 25 ° C. of the protective layer, but the absorbance ratio (P2 / P1) satisfies the above condition, and the oxygen transmission coefficient at 25 ° C. of the protective layer satisfies the above condition. By satisfying these conditions, a photoreceptor that can further improve electrical characteristics and achieve higher image quality can be obtained.
The thickness of the protective layer is preferably 0.5 to 15 μm, more preferably 1 to 10 μm, and more preferably 1 to 5 μm.

The toner used in the present invention contains at least a binder resin and a colorant, and a release agent and other components as necessary. The toner used in the present invention preferably has a shape factor SF in the range of 115 to 140, more preferably 120 to 135. When the shape factor is 115 or less, the development transferability of the toner itself is improved, but the scraping removal property of the discharge product adhering to the surface of the photoreceptor at the cleaning nip is lowered. When the shape factor is 140 or more, the development transferability is significantly lowered.
In the present invention, the shape factor SF is a value calculated based on the following equation.
SF = (maximum toner length) ² × π × 100 / (area of projected toner image × 4)
The maximum toner length and the area of the projected toner image can be determined by using, for example, an image analyzer (LUZEX III, manufactured by Nireco).

  The volume average particle size of the toner is preferably 3 to 9 μm, more preferably 3 to 7 μm, and particularly preferably 4 to 6 μm. When the volume average particle diameter of the toner is 3 to 9 μm, the electrostatic latent image dot development reproducibility is improved, toner scattering during transfer is greatly improved, and the image quality can be remarkably improved. Further, by setting the shape factor of the toner within the above range, the development and transfer properties are further improved, and the latitude reliability of the development system and the transfer system can be remarkably improved. Regarding the cleaning property, generally, when an elastic blade is used, toner that has not been transferred, that is, so-called transfer residual toner, enters the blade nip, and particles having a smaller particle size tend to enter the blade edge tip. It is presumed that the edge tip portion, that is, the region where the blade pressing pressure stress is high also has high pressing pressure stress on the photosensitive member, and it is easily estimated that the discharge product or the like attached to the surface of the photosensitive member is scraped off in this region. By setting the toner shape index within the above range, it is possible to suppress toner slipping from the blade edge and maintain the scraping property on the surface of the photoreceptor.

  Binder resins used in the toner include styrenes such as styrene and chlorostyrene, monoolefins such as ethylene, propylene, butylene and isoprene, vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate and vinyl butyrate. , Α-methylene aliphatic monocarboxylic such as methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate Examples of homopolymers and copolymers of acid esters, vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, and vinyl butyl ether, and vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and vinyl isopropenyl ketone Particularly typical binder resins include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, and styrene. Mention may be made of maleic anhydride copolymer, polyethylene, polypropylene and the like. Further examples include polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, paraffin wax and the like.

  In addition, toner colorants include magnetic powders such as magnetite and ferrite, carbon black, aniline blue, caryl blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, and malachite green oxa. Rate, lamp black, rose bengal, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 57: 1, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 17, C.I. I. Pigment blue 15: 1, C.I. I. Pigment Blue 15: 3 can be exemplified as a representative one.

Typical examples of the release agent include low molecular weight polyethylene, low molecular weight polypropylene, Fischer tropic wax, montan wax, carnauba wax, rice wax, and candelilla wax.

  The method for producing the toner is not particularly limited, and a known production method can be applied. For example, a kneading pulverization method in which a binder resin and a colorant, and if necessary, a release agent, a charge control agent, etc. are kneaded, pulverized, and classified; particles obtained by the kneading pulverization method are subjected to mechanical impact force or thermal energy. The method of changing the shape by emulsion polymerization of the polymerizable monomer of the binder resin and mixing the formed dispersion with a dispersion of a colorant, if necessary, a release agent, a charge control agent, etc. An emulsion polymerization aggregation method for obtaining toner particles by agglomeration and heat fusion; a solution of a polymerizable monomer and a colorant for obtaining a binder resin, if necessary, a release agent, a charge control agent, etc. Suspension polymerization method in which the solution is suspended and polymerized; Dissolution suspension method in which a binder resin, a colorant, a release agent, and a charge control agent, if necessary, are suspended in an aqueous solvent and granulated; etc. Can be mentioned. In addition, a manufacturing method may be performed in which the toner particles obtained by the above method are used as a core, and aggregated particles are further adhered and heat-fused to have a core-shell structure.

To the toner used in the present invention, spherical fine particles can be added as an external additive. The spherical fine particles preferably have a volume average particle size in the range of 0.03 to 0.5 μm, more preferably in the range of 0.1 to 0.3 μm. If it is smaller than 0.03 μm, the toner tends to be embedded inside the toner due to agitation stress in the developing machine, the transferability of the development is deteriorated, and the fine particle cannot be effectively supplied to the edge of the cleaning blade, so that the blade lubrication effect is lowered. Furthermore, the cleaning blade tip deformed portion tends to aggregate and cannot exhibit an effective lubricating effect.
On the other hand, if it is larger than 0.5 μm, it can be easily detached from the toner surface by stirring stress in the developing machine and cannot be stably and effectively supplied to the cleaning blade.
By adding spherical fine particles having a volume average particle size of 0.03 to 0.5 μm as an external additive, it is possible to further improve the development transferability and at the same time suppress friction between the blade and the photoreceptor. It is possible to reduce wear.

  As the spherical fine particles, either inorganic fine particles or organic fine particles can be used. Inorganic fine particles include silica, alumina, titania, zirconia, barium titanate, aluminum titanate, strontium titanate, magnesium titanate, zinc oxide, chromium oxide, cerium oxide, antimony oxide, tungsten oxide, tin oxide, tellurium oxide, Various inorganic oxides such as manganese oxide, boron oxide, silicon carbide, boron carbide, titanium carbide, silicon nitride, titanium nitride, and boron nitride, nitrides, borides, and the like are preferably used.

  Further, titanium coupling agents such as tetrabutyl titanate, tetraoctyl titanate, isopropyl triisostearoyl titanate, isopropyl tridecylbenzenesulfonyl titanate, bis (dioctyl pyrophosphate) oxyacetate titanate, γ- (2-amino) Ethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-β- (N-vinylbenzylaminoethyl) γ-aminopropyltrimethoxysilane Hydrochloride, hexamethyldisilazane, methyltrimethoxysilane, butyltrimethoxysilane, isobutyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane The treatment may be performed with a silane coupling agent such as run, decyltrimethoxysilane, dodecyltrimethoxysilane, phenyltrimethoxysilane, o-methylphenyltrimethoxysilane, and p-methylphenyltrimethoxysilane. Further, hydrophobic treatment with a higher fatty acid metal salt such as silicone oil, aluminum stearate, zinc stearate, calcium stearate can be preferably performed.

  Examples of the organic fine particles include styrenes such as styrene and chlorostyrene, monoolefins such as ethylene, propylene, butylene, and isoprene, vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, and vinyl acetate, and methyl acrylate. , Α-methylene aliphatic monocarboxylic esters such as ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate, vinyl Examples include homopolymers and copolymers of vinyl ethers such as ethyl ether and vinyl butyl ether, vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and vinyl isopropenyl ketone. Particularly representative resins include polystyrene resin, polyester resin, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-anhydrous maleate. Examples thereof include acid copolymers, polyethylene resins, and polypropylene resins. Further examples include polyurethane resins, epoxy resins, silicone resins, polyamide resins, and modified rosins.

The lubricant used in the toner according to the present invention is not particularly limited, but at least one selected from fatty acid metal salts and higher alcohols is preferable.
Fatty acid metal salts include metal salts of stearic acid cadmium, barium, lead, iron, nickel, cobalt, copper, aluminum, magnesium, etc .; dibasic lead stearate; zinc oleate, magnesium, iron, cobalt, copper, Metal salts such as lead and calcium; metal salts such as palmitic acid and aluminum and calcium; lead caprylate; lead caproate; zinc linoleate; cobalt linoleate; calcium ricinoleate; metal salts such as ricinoleic acid and zinc and cadmium; Among them, zinc stearate is preferable because of its high lubricating effect.

  Other lubricant components include solid lubricants such as graphite, molybdenum disulfide, talc, and fatty acids; low molecular weight polyolefins such as polypropylene, polyethylene, and polybutene; silicones that have a softening point upon heating, oleic acid amide, erucic acid amide, Aliphatic amides such as ricinoleic acid amide and stearic acid amide; plant waxes such as carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil; animal waxes such as beeswax; montan wax , Minerals such as ozokerite, ceresin, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, petroleum wax; modified products thereof, etc. may be used in combination.

  The abrasive used in the toner according to the present invention is preferably an amorphous inorganic fine powder having a Mohs hardness of 3 or more and a volume average particle size of 0.03 to 0.8 μm. If the Mohs hardness is less than 3, the surface refreshing property of the photoreceptor cannot be obtained. On the other hand, if the volume average particle size is smaller than 0.03 μm, the blade nip part tends to aggregate and the surface of the photoreceptor is inferior in uniform polishing. On the other hand, if the thickness is larger than 0.8 μm, the roughness of the photosensitive member increases and the scratches are easily damaged. The above-mentioned materials can be used as the amorphous inorganic fine particles, but aluminum oxide, cerium oxide, strontium titanate and the like are particularly preferable.

To the toner obtained above, a known powder fluidizing agent may be additionally added and used.

<Image forming method>
The image forming method of the present invention includes a charging step for uniformly charging the surface of the photoconductor, a latent image forming step for forming a latent image on the charged surface of the photoconductor, and a surface of the photoconductor. A developing step of developing a latent image with a developer containing at least toner to form a toner image, a primary transfer step of primary transferring a toner image formed on the surface of the photosensitive member to an intermediate transfer member, and the intermediate transfer A secondary transfer process in which the toner image primarily transferred to the body is secondarily transferred to the transfer body, a fixing process in which the toner image transferred to the transfer body is fixed, and a residual surface of the photoreceptor after transfer A cleaning step for removing toner with a cleaning blade, and cyan, magenta, yellow and black toner images are formed on the surface of the photoconductor, and toner images of respective colors are sequentially formed from the photoconductor. An image forming method for forming a color image by primary transfer to the intermediate transfer member, wherein the outermost surface layer of the photosensitive member is a protective layer, and one color among cyan toner, magenta toner, yellow toner and black toner The three-color toner contains an abrasive as an external additive, the other toner contains a lubricant as an external additive, the toner containing the abrasive does not contain the lubricant as an external additive, and the lubricant The toner set containing toner contains a toner set that does not contain the abrasive as an external additive.

In the image forming method of the present invention, the above-described charging process and latent image formation are performed for each toner of cyan (C) toner, magenta (M) toner, yellow (Y) toner, and black (K) toner on a single photoreceptor surface. The process, the development process, and the primary transfer process are repeated, and an unfixed toner image of each color is superimposed on the intermediate transfer member to form a full color image.
The image forming method of the present invention can be carried out by the above-described image forming apparatus of the present invention.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example, this invention is not limited by the following Example. In the following description, “part” means “part by mass” unless otherwise specified.

<Preparation of Photoreceptor 1>
To 170 parts of n-butyl alcohol in which 4 parts of polyvinyl butyral resin (S-REC BM-S, manufactured by Sekisui Chemical Co., Ltd.) was dissolved, 30 parts of an organic zirconium compound (acetylacetone zirconium butyrate) and an organic silane compound (γ-aminopropyltrimethoxy) 3 parts of silane) was added, mixed and stirred to obtain a coating solution for forming an undercoat layer. This coating solution is dip-coated on an aluminum support having an outer diameter of 84 mm roughened by a honing treatment, and after air drying at room temperature for 5 minutes, the support is heated to 50 ° C. for 10 minutes, It was placed in a constant temperature and humidity chamber at 50 ° C. and 85% RH (dew point 47 ° C.), and a humidification hardening acceleration treatment was performed for 20 minutes. Then, it put in the hot air dryer and dried for 10 minutes at 170 degreeC, and formed the undercoat layer.
As a charge generation material, a mixture of 15 parts of gallium chloride phthalocyanine, 10 parts of vinyl chloride-vinyl acetate copolymer resin (VMCH, manufactured by Nippon Union Carbide) and 300 parts of n-butyl alcohol was dispersed in a sand mill for 4 hours. The obtained dispersion was dip-coated on the undercoat layer and dried to form a charge generation layer having a thickness of 0.2 μm.
Next, 40 parts of N, N'-bis (3-methylphenyl) -N, N'-diphenylbenzidine and 60 parts of bisphenol Z polycarbonate resin (viscosity average molecular weight 40,000) were added to 280 parts of tetrahydrofuran and 120 parts of toluene. It was sufficiently dissolved and mixed in the mixed solvent.
The obtained coating solution was dip-coated on the charge generation layer and dried to form a charge transport layer having a thickness of 24 μm. This is a photoreceptor 1.

<Photoreceptor 2>
The undercoat layer, the charge generation layer, and the charge transport layer were formed in the same procedure as that of the photoreceptor 1 except that the film thickness of the charge transport layer was 20 μm. Furthermore, the constituent materials shown below are dissolved in a mixed solvent of 5 parts of isopropyl alcohol, 3 parts of tetrahydrofuran and 0.3 part of distilled water, 0.5 parts of ion exchange resin (Amberlyst 15E) is added, and the mixture is stirred at room temperature. For 24 hours.
Constituent materials The following compounds 1 2 parts Methyltrimethoxysilane 2 parts Tetramethoxysilane 0.5 parts Colloidal silica 0.3 parts Fluorine graft polymer (ZX007C: manufactured by Fuji Kasei) 0.5 parts Filter the ion exchange resin from the hydrolyzed one 0.1 parts of aluminum trisacetylacetonate (Al (aqaq) ₃ ) and 0.4 parts of 3,5-di-t-butyl-4-hydroxytoluene (BHT) are added to the separated liquid. The protective layer-forming coating solution is applied onto the charge transport layer by a ring-type dip coating method, air-dried at room temperature for 30 minutes, cured by heat treatment at 150 ° C. for 1 hour, and a protective layer having a thickness of 3 μm. Formed. This is a photoreceptor 2.

<Photoreceptor 3>
By mixing 5 parts of Compound 1, 15 parts of isopropyl alcohol, 9 parts of tetrahydrofuran, and 0.9 part of distilled water, 0.5 parts of ion exchange resin (Amberlyst 15E) is added thereto, and the mixture is stirred at room temperature. Hydrolysis was performed for 2 hours. Furthermore, 0.5 part of butyral resin, 5 parts of resol type phenol resin (PL-2211, manufactured by Gunei Chemical Co., Ltd.), 0.2 part of Sanol LS2626 (manufactured by Sankyo Lifetech) as a light stabilizer, and catalyst A coating solution for forming a protective layer was prepared by adding 0.5 part of Nail Cure 4167 (manufactured by Enomoto Kasei). This protective layer-forming coating solution is dip-coated on a charge transport layer prepared under the same conditions as the photoreceptor 1 except that the charge transport layer has a thickness of 22 μm, dried at 140 ° C. for 40 minutes, and has a thickness of 3 μm. A protective layer was formed. The obtained photoreceptor is designated as photoreceptor 3.

<Preparation of developer>
A developer was prepared by the following method. Each physical property value was measured by the following method.
(Volume average particle size)
Particles in the order of μm, such as toner mother particles, toner, aggregated particles, and lubricant, were measured with a multisizer (manufactured by Nikka Kisha Co., Ltd.) with an aperture diameter of 100 μm.
Particles in the order of nm such as resin particles, colorant particles, release agent particles, abrasives, and other fine particles were measured using a scanning electron microscope.
(Shape factor SF)
The shape factor SF means a value calculated by the following formula. In the case of a true sphere, SF = 100.
SF = (maximum toner length) ² × π × 100 / (area of projected toner image × 4)
As a specific method for obtaining the shape factor, a toner image is taken from an optical microscope into an image analyzer (LUZEX III, manufactured by Nireco), the equivalent circle diameter is measured, and the maximum length and area are determined for each individual toner. The SF value of the above equation was obtained, and the average of 100 toners was taken as the shape factor SF.

Preparation of Developer 1 (K), Developer 1 (Y), Developer 1 (M), and Developer 1 (C) [Manufacture of toner mother particles]
(Adjustment of resin fine particle dispersion)
370 parts of styrene, 30 parts of n-butyl acrylate, 8 parts of acrylic acid, 24 parts of dodecanethiol and 4 parts of carbon tetrabromide were mixed and dissolved in a nonionic surfactant (Nonipol 400: Sanyo Chemical Co., Ltd. )) 6 parts and 10 parts of anionic surfactant (Neogen SC: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) were dissolved in 550 parts of ion-exchanged water, and this was mixed while slowly mixing for 10 minutes. Was charged with 50 parts of ion-exchanged water in which 4 parts of ammonium persulfate was dissolved. After carrying out nitrogen substitution, the inside of the flask was stirred and heated in an oil bath until the contents reached 70 ° C., and emulsion polymerization was continued for 5 hours. As a result, a resin fine particle dispersion in which resin particles having a volume average particle size of 150 nm, a glass transition point of 58 ° C., and a weight average molecular weight Mw = 11500 was obtained. The solid content concentration of this dispersion was 40% by mass.

(Adjustment of colorant dispersion (1))
Carbon black (Mogal L: manufactured by Cabot) 60 parts Nonionic surfactant (Nonipol 400: manufactured by Sanyo Chemical Co., Ltd.) 6 parts Ion-exchanged water 240 parts The above ingredients are mixed together to produce a homogenizer (Ultra Turrax T50: IKA). The colorant dispersant (1) in which the colorant (carbon black) particles having a volume average particle size of 250 nm are dispersed is prepared by stirring with an optimizer for 10 minutes. .

(Adjustment of colorant dispersion (2))
Cyan Pigment B15: 3 60 parts Nonionic surfactant (Nonipol 400: manufactured by Sanyo Chemical Co., Ltd.) 5 parts Ion-exchanged water 240 parts The above ingredients were mixed and a homogenizer (Ultra Turrax T50: manufactured by IKA) was added. The mixture was stirred for 10 minutes, and then dispersed with an optimizer to prepare a colorant dispersant (2) in which colorant (Cyan pigment) particles having a volume average particle diameter of 250 nm were dispersed.

(Adjustment of colorant dispersion (3))
Magenta Pigment R122 60 parts Nonionic surfactant (Nonipol 400: manufactured by Sanyo Kasei Co., Ltd.) 5 parts Ion-exchanged water 240 parts The above ingredients were mixed and a homogenizer (Ultra Turrax T50: manufactured by IKA) was used. After stirring for 10 minutes, a colorant dispersant (3) in which colorant (Magenta pigment) particles having a volume average particle diameter of 250 nm were dispersed was prepared by dispersing with an optimizer.

(Adjustment of colored dispersion (4))
Yellow pigment Y180 90 parts Nonionic surfactant (Nonipol 400: manufactured by Sanyo Chemical Co., Ltd.) 5 parts Ion-exchanged water 240 parts The above ingredients were mixed and a homogenizer (Ultra Turrax T50: manufactured by IKA) was used. After stirring for 10 minutes, a colorant dispersant (4) in which colorant (Yellow pigment) particles having a volume average particle diameter of 250 nm were dispersed was prepared by dispersing with an optimizer.

(Release agent dispersion)
Paraffin wax (HNP0190: Nippon Seiwa Co., Ltd., melting point 85 ° C.)
100 parts Cationic surfactant (Sanisol B50: manufactured by Kao Corporation) 5 parts ion-exchanged water 240 parts Using the above ingredients in a round stainless steel flask using a homogenizer (Ultra Turrax T50: manufactured by IKA) Then, the dispersion was performed with a pressure discharge type homogenizer to prepare a release agent dispersion liquid in which release agent particles having a volume average particle diameter of 550 nm were dispersed.

<Adjustment of toner mother particle K1>
Resin fine particle dispersion 234 parts Colorant dispersion (1) 30 parts Release agent dispersion 40 parts Polyaluminum hydroxide (Pho2S, manufactured by Asada Chemical Co., Ltd.) 0.5 parts Ion-exchanged water 600 parts After mixing and dispersing in a round stainless steel flask using a homogenizer (Ultra Turrax T50: made by IKA), the inside of the flask was heated in an oil bath for heating at a rotation speed of 300 rpm using a 100 mm diameter four-paddle type impeller. And heated to 40 ° C. with stirring. After maintaining at 40 ° C. for 30 minutes, it was confirmed that aggregated particles having a volume average particle diameter of 4.5 μm were formed. Further, the temperature of the heating oil bath was raised and maintained at 56 ° C. for 1 hour, and the volume average particle size became 5.3 μm. Thereafter, 26 parts of the resin fine particle dispersion was added to the dispersion containing the aggregate particles, and then the temperature of the heating oil bath was raised to 50 ° C. and held for 30 minutes. After adding 1N sodium hydroxide to the dispersion containing the aggregate particles and adjusting the pH of the system to 7.0, the stainless steel flask is sealed and heated to 80 ° C. while continuing stirring using a magnetic seal. And held for 4 hours. After cooling, the toner base particles were separated by filtration, washed four times with ion exchange water, and then lyophilized to obtain toner base particles K1. The toner base particle K1 has a volume average particle size of 5.9 μm and a shape factor SF of 132.

<Adjustment of toner base particle C1>
Toner base particles C1 were obtained in the same manner as toner base particles K1, except that the colored particle dispersion (2) was used instead of the colored particle dispersion (1). The toner base particle C1 has a volume average particle size of 5.8 μm and a shape factor SF of 131.
<Adjustment of toner mother particle M1>
Toner mother particles M1 were obtained in the same manner as toner mother particles K1, except that the colored particle dispersion (3) was used instead of the colored particle dispersion (1). The toner mother particles M1 had a volume average particle size of 5.5 μm and a shape factor SF of 135.
<Adjustment of toner base particle Y1>
Toner base particles Y1 were obtained in the same manner as toner base particles K1, except that the colored particle dispersion (4) was used instead of the colored particle dispersion (1). The toner base particles Y1 have a volume average particle size of 5.9 μm and a shape factor SF of 130.

  100 parts of each of the toner base particles K1 and C1 were obtained by rutile type titanium oxide (volume average particle diameter 20 nm, n-decyltrimethoxysilane treatment) 1 part, hydrophobic silica (volume average particle diameter 135 nm, obtained by sol-gel method). After blending 1.2 parts of hexamethyldisilazane to silica sol and 0.1 parts of zinc stearate (lubricant, volume average particle size 5 μm) with a 5 L Henschel mixer, peripheral speed 30 m / s × 15 minutes, then 45 μm Coarse particles were removed using a sieve having a mesh size of No. 1 to obtain toners K1 and C1. Further, 100 parts of each of the toner base particles M1 and Y1 is obtained by 1 part of rutile type titanium oxide (volume average particle diameter 20 nm, n-decyltrimethoxysilane treatment) and hydrophobic silica (volume average particle diameter 135 nm, obtained by sol-gel method). After blending 1.2 parts of hexamethyldisilazane to silica sol and 0.3 parts of cerium oxide (abrasive, volume average particle size 0.5 μm) with a 5 L Henschel mixer at a peripheral speed of 30 m / s × 15 minutes. Coarse particles were removed using a sieve having an opening of 45 μm to obtain toners M1 and Y1. The volume average particle diameters of the toners K1, C1, M1, and Y1 are the same as the volume average particle diameters of the corresponding toner base particles.

[Manufacture of carriers]
Ferrite particles (volume average particle size: 50 μm) 100 parts Toluene 14 parts Styrene / methacrylate copolymer (component ratio: 90/10) 2 parts Carbon black (R330: manufactured by Cabot Corporation) 0.2 parts First, ferrite particles are removed The above components are stirred with a stirrer for 10 minutes to prepare a dispersed coating solution. Next, the coating solution and ferrite particles are placed in a vacuum degassing kneader and stirred at 60 ° C. for 30 minutes. A carrier was obtained by degassing while heating and degassing and drying. This carrier had a volume resistivity of 10 ¹¹ Ωcm at an applied electric field of 1000 V / cm.

Further, 100 parts of the carrier and 7 parts of these toners were stirred with a V-blender at 40 rpm × 20 minutes, and sieved with a sieve having an opening of 212 μm, thereby developing 1 (K) and developer 1 (Y ), Developer 1 (M) and Developer 1 (C) were obtained.

Preparation of Developer 2 (K), Developer 2 (Y), Developer 2 (M), and Developer 2 (C) Rutile type titanium oxide (volume average particle diameter) using toner base particles K1 and C1 as an external additive 1 part of 20 nm, n-decyltrimethoxysilane treatment), 1.1 parts of hydrophobic silica (volume average particle size 40 nm, manufactured by RX50 Nippon Aerosil), higher alcohol (lubricant, volume average particle size 5 μm, UNILIN 700 Nippon Petrolite Developer 2 (K, C) was produced under the same conditions as Developer 1 using 0.3 part of (manufactured by Co., Ltd.). In addition, toner base particles M1 and Y1 are used as external additives, 1 part of rutile type titanium oxide (volume average particle size 20 nm, n-decyltrimethoxysilane treatment), hydrophobic silica (volume average particle size 40 nm, RX50 Nippon Aerosil Co., Ltd.) Developer 2 (M, Y) was produced under the same conditions as Developer 1 using 1.1 parts of aluminum oxide and 0.4 parts of aluminum oxide (abrasive, volume average particle size 0.3 μm). The volume average particle diameters of the toners K2, C2, M2, and Y2 were the same as the volume average particle diameters of the corresponding toner base particles.

Preparation of Developer 3 (K), Developer 3 (Y), Developer 3 (M), and Developer 3 (C) Using toner base particles K1, C1, M1, and Y1, rutile titanium oxide as an external additive (Volume average particle size 20 nm, n-decyltrimethoxysilane treatment) 1 part, hydrophobic silica (volume average particle size 135 nm, silica sol obtained by sol-gel method treated with hexamethyldisilazane) 1.2 parts, zinc stearate Developer 3 (K, C, M, Y) was prepared using 0.1 part of (lubricant, volume average particle size 5 μm) under the same conditions as Developer 1. The volume average particle diameters of the toners K3, C3, M3, and Y3 were the same as the volume average particle diameters of the corresponding toner base particles.

Preparation of Developer 4 (K), Developer 4 (Y), Developer 4 (M), and Developer 4 (C) Using toner base particles K1, C1, M1, and Y1, rutile titanium oxide as an external additive (Volume average particle diameter 20 nm, n-decyltrimethoxysilane treatment) 1 part, hydrophobic silica (volume average particle diameter 135 nm, silica sol obtained by sol-gel method treated with hexamethyldisilazane) 1.2 parts, aluminum oxide ( Developer 4 (K, C, M, Y) was produced under the same conditions as Developer 1, using 0.4 parts of an abrasive and a volume average particle size of 0.3 μm. The volume average particle diameters of the toners K4, C4, M4, and Y4 were the same as the volume average particle diameters of the corresponding toner base particles.

Preparation of Developer 5 (K), Developer 5 (Y), Developer 5 (M), and Developer 5 (C) Using toner base particles K1, C1, M1, and Y1, rutile titanium oxide as an external additive (Volume average particle size 20 nm, n-decyltrimethoxysilane treatment) 1 part, hydrophobic silica (volume average particle size 135 nm, silica sol obtained by sol-gel method treated with hexamethyldisilazane) 1.2 parts, aluminum oxide ( Developer 5 (K, K) under conditions similar to those of Developer 1 using 0.4 parts of an abrasive, volume average particle diameter 0.3 μm) and 0.1 parts of zinc stearate (lubricant, volume average particle diameter 5 μm). C, M, Y) were prepared. The volume average particle diameters of the toners K5, C5, M5, and Y5 were the same as the volume average particle diameters of the corresponding toner base particles.

[Example 1]
Evaluation with an actual machine was performed using DocuCenter Color 1250 manufactured by Fuji Xerox Co., Ltd. The DocuCenter Color 1250 is an apparatus capable of performing the image forming method of the present invention. The photoconductor 2 is used as the photoconductor, the developer 1 (KCMY) is used as the developer, and the cleaning part is composed of a cleaning blade made of urethane rubber (JISA hardness is 82 °, rebound resilience is 20%). The pressure is set to 3.0 gf / mm.
In the color mode, a running test was conducted on 20,000 sheets at high temperature and high humidity (28 ° C, 80% RH) and low temperature and low humidity (10 ° C, 15% RH) for a total of 40,000 sheets. The amount of wear of the photoreceptor was evaluated.

Judgment criteria for “image flow”, “photoconductor wear amount”, “cleanability”, and “overall evaluation” are shown below.
(Image flow)
A halftone image having an image density of 30% was taken under high temperature and high humidity during a running test, and sensory evaluation was performed. Judgment criteria are as follows.
○: Image flow has not occurred ×: Image flow has occurred (photoconductor wear amount)
The wear rate of the photoconductor was determined from the difference between the initial photoconductor thickness and the film thickness after running 40,000 sheets.
A: Wear rate ˜1.5 nm / kcycle
○: Abrasion rate ˜3 nm / kcycle
X: Abrasion rate 3 nm ~ / kcycle
(Cleanability)
The evaluation was performed by cleaning the presence or absence of a poorly-cleaned image in the printed image while running under low temperature and low humidity, and periodically cleaning an untransferred A3-sized image density 100% image. Judgment criteria are as follows.
A: There is no cleaning problem in both the printed image and the non-transferred image. ○: There is no cleaning problem in the printed image, and there is a delicate cleaning defect in the non-transferred image.
◎: Long life and high reliability are compatible ○: Long life can be achieved but reliability is slightly inferior ×: Long life cannot be achieved Table 1 shows the results.

[Example 2]
A test similar to that in Example 1 was performed except that Developer 2 (KCMY) was used. The test results are shown in Table 1.

[Example 3]
The same test as in Example 1 was performed except that a cleaning blade having a JISA hardness of 75 ° and a rebound resilience of 50% was used. The test results are shown in Table 1.

[Example 4]
The same test as in Example 2 was performed except that a cleaning blade having a JISA hardness of 90 ° and a rebound resilience of 15% was used. The test results are shown in Table 1.

[Comparative Example 1]
The same test as in Example 1 was performed except that Developer 3 (KCMY) was used. The test results are shown in Table 1.

[Comparative Example 2]
The same test as in Example 1 was performed except that Developer 4 (KCMY) was used. The test results are shown in Table 1.

[Comparative Example 3]
The same test as in Example 1 was performed except that Developer 5 (KCMY) was used. The test results are shown in Table 1.

[Comparative Example 4]
The same test as in Example 3 was performed except that the photoreceptor 1 was used. The test results are shown in Table 1.

[Example 5]
The same test as in Example 1 was performed except that the photoreceptor 3 was used. The test results are shown in Table 1.

[Example 6]
The same test as in Example 2 was performed except that the photoreceptor 3 was used. The test results are shown in Table 1.

[Example 7]
The same test as in Example 3 was performed except that the photoreceptor 3 was used. The test results are shown in Table 1.

[Example 8]
The same test as in Example 4 was performed except that the photoreceptor 3 was used. The test results are shown in Table 1.

  From Table 1, it can be seen that the structure of the present invention can achieve a long life and high reliability of the photoreceptor and the cleaner.

1 is a schematic configuration diagram illustrating an example of an embodiment of an image forming apparatus of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging device 3 Image writing means 4 Developing device 5 Primary transfer device 6 Cleaning device 7 Transfer belt 8 Tension roll 9 Backup roll 10 Bias roll 11 Belt cleaner 13 Paper feed tray 14 Fixing device

Claims (2)

A photosensitive member; a charging unit that uniformly charges the photosensitive member; a latent image forming unit that forms a latent image on the surface of the charged photosensitive member; and a latent image formed on the surface of the photosensitive member at least as a toner. Developing means for forming a toner image by developing with a developer containing a toner, an intermediate transfer body on which the toner image formed on the surface of the photoreceptor is primarily transferred, and a toner image formed on the surface of the photoreceptor Primary transfer means for primary transfer of the toner image to the intermediate transfer body, secondary transfer means for secondary transfer of the toner image primarily transferred to the intermediate transfer body to the transfer target body, and toner image transferred to the transfer target body At least a fixing means for fixing the toner, and a cleaning means including a cleaning blade for removing residual toner on the surface of the photoconductor after the transfer. Each toner of cyan, magenta, yellow and black is provided on the surface of the photoconductor. Image is the color toner image from the photosensitive member is primarily transferred sequentially to the intermediate transfer member while being formed by an image forming apparatus for forming a color image,
The outermost surface layer of the photoreceptor is a protective layer,
Among cyan, magenta, yellow, and black toners, one to three color toners contain an abrasive as an external additive, and the other toners contain a lubricant as an external additive, and the toner contains the abrasive. An image forming apparatus using a toner set that does not contain the lubricant as an external additive, and the toner containing the lubricant does not contain the abrasive as an external additive. A charging step for uniformly charging the surface of the photoreceptor, a latent image forming step for forming a latent image on the charged surface of the photoreceptor, and a latent image formed on the surface of the photoreceptor containing at least toner. A developing step of developing with a developer to form a toner image, a primary transfer step of primarily transferring the toner image formed on the surface of the photoreceptor to an intermediate transfer member, and a toner image primarily transferred to the intermediate transfer member A secondary transfer process for secondary transfer of the toner onto the transfer body, a fixing process for fixing the toner image transferred to the transfer body, and a cleaning for removing residual toner on the surface of the photoreceptor after the transfer with a cleaning blade A toner image of cyan, magenta, yellow and black is formed on the surface of the photoconductor, and a toner image of each color is sequentially transferred from the photoconductor to the intermediate transfer body. A is an image forming method for forming a color image,
The outermost surface layer of the photoreceptor is a protective layer,
Among cyan, magenta, yellow, and black toners, one to three color toners contain an abrasive as an external additive, and the other toners contain a lubricant as an external additive, and the toner contains the abrasive. Forming an image using a toner set that does not contain the lubricant as an external additive, and the toner containing the lubricant does not contain the abrasive as an external additive.

Images