JP2010026232A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus incorporating a cleaner which can reduce the flaw on the photoreceptor with less toner remains or accumulation on it even after used for a long time period and thus maintain high image quality over a long time period. <P>SOLUTION: This image forming apparatus includes a photoreceptor, a means to form latent images on the photoreceptor, a means to develop electrostatic latent images, a means to transfer the developed toner images to a transfer object body, and a cleaning means to clean the toner still remaining on the photoreceptor surface after transferring the toner images to the transfer object body. This cleaning means is composed of a conductive brush used by applying a voltage and in contact with the photoreceptor surface at least, and a toner recovery means which is in contact with the conductive brush to collect toner. Further, this image forming apparatus includes a sliding friction component which includes fine fibers and is disposed on the photoreceptor surface upstream the conductive brush in the photoreceptor turning direction and at a position in contact with the conductive brush. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus using an electrophotographic system such as a copying machine, a facsimile machine, and a printer.

  Conventionally, in electrophotography, an electrostatic latent image produced by charging and exposing the surface of a photoreceptor is developed with a colored toner to form a toner image, and then the toner image is transferred to a transfer paper or the like, and further heated rolls, etc. And fixing to form an image. Since untransferred toner and toner components, discharge products generated by the charging process, and the like remain on the surface of the photosensitive member (hereinafter sometimes referred to as “latent image carrier”) after the transfer process, A cleaning process is required to remove objects prior to the next image forming process.

  As a means for cleaning the photosensitive member, a blade cleaning method using an elastic cleaning blade or a brush cleaning method using a magnetic brush or a fur brush is used. Among them, the method of bringing the rubber blade into contact with the photosensitive member is most widely used because it is simple.

  However, with the cleaning blade method, due to the mechanical friction between the blade and the photoconductor, the wear of the photoconductor tends to progress when using an organic photoconductor, and the life of the photoconductor cannot be extended significantly, especially for on-demand printing. In a high-speed machine that is used, there is a drawback that the cleaning reliability cannot be maintained over a long period of time because the tip and tip of the cleaning blade are noticeably worn.

  On the other hand, in recent years, there has been a demand for higher image quality in this type of image forming apparatus, and as a means for this, toner by a polymerization method has been used. The toner obtained by the polymerization method can be remarkably reduced in particle size, narrowed in particle size distribution, and spheroidized, and can improve dot reproducibility, developability, and transferability.

  However, when the blade cleaning method is used, a toner having a small particle size and a nearly spherical shape requires a higher blade pressing pressure for toner removal than the conventional irregularly pulverized toner. There is a problem that the scratches on the photoreceptor deteriorate. Furthermore, in a high-speed machine, when a large amount of prints are taken at a time and the non-image part continues for a long time, since the toner component is not supplied to the blade edge part, lubrication is hindered, so blade turning and blade wear progress significantly. The cleaning performance is degraded.

  In contrast to the blade cleaning method, a brush cleaning method using a conductive brush such as a fur brush has little deterioration in cleaning performance with time. In particular, in a high-speed machine, the brush cleaning method is advantageous over the blade cleaning method. Further, since brush cleaning is a cleaning method that positively uses an electric field, it has an advantage over spherical toner cleaning that was difficult with the blade method.

However, in the case of the brush cleaning method, compared with the method in which the pressing load of the rubber blade is increased, the mechanical scraping force on the surface of the photoconductor is reduced, so that the discharge products generated from the charger cannot be sufficiently removed. There is a possibility that image blur (image flow) is likely to occur. When the photosensitive member is charged by the charging means by corona charger or a conductive roller or the like, discharge products such as ozone and NO _x are known to occur in this process. These ozone and NO _x adhered to the photoreceptor surface combines with moisture in the atmosphere, to reduce the electric resistance of the surface of the photoreceptor becomes difficult to retain on the photoreceptor charge is presumed that the image blur occurs .

  In particular, in a high-speed machine, it is necessary to set a high current value in order to charge the photoconductor, and a large amount of discharge products tend to adhere to the surface of the photoconductor, which is considered to promote the image blurring phenomenon. In addition, since the scraping property is low, the removal property of fine deposits such as an external additive as a developer component is also inferior, so that external additive filming is likely to occur.

  Brush cleaning method that effectively scrapes discharge products and filming (hereinafter collectively referred to as a photoreceptor deterioration layer) on the photoreceptor without degrading the long-term cleaning reliability with respect to the above-described problem of reduction in scraping ability. As an auxiliary means, a method of bringing a fine fiber member such as a non-woven fabric into contact with the surface of the photoreceptor has been studied. The fine fiber member is considered to be effective for scraping off the photoreceptor-deteriorated layer because the microfiber member can hold the toner densely while allowing the microfiber to have a moderate throughput.

  As a form of the scraping member, there is a configuration in which the surface of the pressing member made of a pad-like sponge or a rubber layer is covered with a fine fiber member. When the rubbing member is placed on the downstream side of the brush, a small amount of toner that has passed through the brush accumulates in the rubbing member while continuing to run for a long time, and the movement of the member such as the start and end of operation If the toner becomes irregular, the accumulated toner may be discharged, so it is preferable to provide it upstream of the brush cleaner.

  However, when the rubbing member is brought to the upstream side of the brush cleaner, there is a case where the gap between the rubbing member and the brush cleaner is around the surface of the rubbing member close to the brush cleaner (hereinafter referred to as a post nip portion). ) Or toner that has been scraped off by a brush cleaner accumulates on the rubbing member.

  If the toner is excessively accumulated, the toner is hardened and easily reattached to the photoreceptor, and image quality defects occur when the toner cannot be cleaned with a brush cleaner. This is because the possibility of this problem increases as the image formation progresses. Therefore, it is considered difficult to maintain the cleaning reliability for a long time unless this problem is solved.

  To solve this problem, a technique has been proposed in which corners of a foamed elastic body provided with a nonwoven fabric are applied to the photoconductor to remove filming and paper dust on the photoconductor while reducing the contact area and pressing force. (For example, refer to Patent Document 1).

JP 2000-206850 A

  However, even if a cleaner-less system is premised, after a long period of use, there is a high possibility that toner will accumulate on the downstream side of the post-nip portion with the foamed photoreceptor. Is considered inevitable.

  The present invention has been made in view of the above situation, and can suppress the remaining or accumulation of toner on the photosensitive member while suppressing damage to the photosensitive member even after long-term use. Accordingly, an object of the present invention is to provide an image forming apparatus including a cleaning device that can maintain high image quality for a long period of time.

  The image forming apparatus according to the present invention includes a photosensitive member, a latent image forming unit that forms an electrostatic latent image on the photosensitive member, a developing unit that develops the electrostatic latent image, and a toner image developed on the photosensitive member. A transfer unit that transfers the toner image to the transfer member; and a cleaning unit that cleans toner remaining on the surface of the photoconductor after the toner image is transferred to the transfer member. A conductive brush used in a state where a voltage is applied, and a collecting unit that contacts the conductive brush and collects toner, and further, the surface of the photoreceptor upstream of the conductive brush with respect to the rotation direction of the photoreceptor A rubbing member provided with a fine fiber member is disposed, and the rubbing member is disposed at a position in contact with the conductive brush.

  The invention according to claim 2 is characterized in that the fiber thickness of the conductive brush is 10 denier or less, and the fiber thickness of the fine fiber member is 10 μm or less.

  The invention according to claim 3 is characterized in that the rubbing member includes a pressing member having elasticity for attaching the fine fiber member, and the surface thereof is pressed against the photosensitive member with a predetermined pressure. Yes.

  The invention according to claim 4 is a fine fiber rotating roller in which the rubbing member is formed by covering the surface of a roll-shaped pressing member with a cylindrical cloth made of a fine fiber member, and the fine fiber rotating roller Is rotated in a direction that is the forward direction of the rotation direction of the photosensitive member.

  The invention according to claim 5 is characterized in that the outermost surface layer of the photoreceptor contains a resin having a structural unit having a charge transporting ability and having a crosslinked structure.

  As a result of the study, the inventors have, as shown in claims 1 and 2, a conductive toner having a fiber thickness of 10 denier or less used as a toner cleaner while being in contact with the surface of the photoreceptor and being applied with a voltage. A brush cleaner comprising a brush and a collecting roller that contacts the conductive brush and collects toner is used. Further, as an auxiliary means of the brush cleaner, an upstream side of the conductive brush with respect to the photoconductor rotating direction is used. By using a rubbing member disposed on the surface of the photoreceptor and having a fine fiber member having a fiber thickness of 10 μm or less, and further disposing the rubbing member at a position in contact with the conductive brush, the above problem can be solved. I found out that

  In the present invention, the most characteristic point is that the contact rubbing member is disposed at a position in contact with the rotating conductive brush roller. With such an arrangement, when the brush rubs the rubbing member, it is possible to direct the toner accumulated excessively on the post nip portion of the rubbing member to be scraped off. At that time, by using a conductive brush having a fiber thickness of 10 denier or less, it is possible to prevent secondary damage caused by the following brush rubbing. That is, when the fiber thickness of the brush is larger than 10 denier, the brush tip force is increased, so that the impact applied to the rubbing member having the fine fibers is increased, and as a result, the friction member with the photosensitive member is increased. There is a concern that the nip state becomes unstable and the scraping property tends to be hindered, and this problem can be avoided.

  In particular, in the case of a high-speed machine, the necessity of rotating the brush at a higher speed is also increased, and the above problem is considered to be more prominent. Therefore, the present invention also exhibits an advantage in this respect. Further, for the fine fiber member provided in the rubbing member, the fine fiber member having a fiber thickness of 10 μm or less can be used to stably hold the toner in the micro fiber, so that the photosensitive member deterioration layer It becomes possible to keep the removability stable.

  As shown in claim 4, in the present invention, as a rubbing member for scraping off the photoreceptor deterioration layer, the surface of the pressing member having a roll-like elasticity is formed by covering a cylindrical cloth made of a fine fiber member. It is also proposed to use a fine fiber rotating roller and to rotate the fine fiber rotating roller in a direction that is in the forward direction with respect to the rotation direction of the photoreceptor. In this way, it is possible to suppress excessive accumulation of toner in the post nip of the rubbing member even after image formation has been performed for a long period of time, and further, the brush rubs the fine fiber rotating roller to fine fiber. It is also possible to keep the toner accumulation amount on the rotating roller constant to some extent.

  As described in claim 5, when the present invention is combined with a low-abrasion photoconductor, it is possible to achieve both the life of the photoconductor wear and the long-term maintenance of the scraping function by the friction of the contact member. When a low-wear photoconductor is combined with a rubber blade set to a high load, the friction at the rubbing portion increases, which is disadvantageous for ensuring long-term cleaning reliability, but when using the contact member of the present invention It will be possible to solve it too.

Hereinafter, the outline and each component of the image forming apparatus of the present invention will be described in detail.
FIG. 1 is a schematic view of an image forming process by an electrophotographic method. Reference numeral 1 denotes a photoconductor. First, a portion corresponding to a colored portion of an image formed by the charging device 2 is charged to form a latent image, and a colored toner is supplied to the latent image portion by the developing device 4. Next, toner is transferred to a medium such as paper held on the intermediate transfer belt 6 by the transfer device 5, and the toner is fixed on the medium by a fixing unit (not shown) to form an electrophotographic image. Since the toner remains on the surface of the photoconductor after the transfer, the cleaning device 7 removes the toner, and the photoconductor 1 is again subjected to the electrophotographic forming process.

<1. Cleaning device>
Here, a brush cleaning method using the conductive brush according to the present invention will be described. As shown in the schematic diagram of FIG. 1, a conductive roll brush member 7 b, a recovery roll member 7 c, and a toner scraping member (hereinafter referred to as a scraper member) 7 d are accommodated in the housing of the cleaning device 7. . Note that a flicking member (not shown) that mechanically knocks off the toner adhering to the roll-shaped brush member 7b may be installed on the collection roll member 7c. As shown in FIG. 3, the rubbing member 17 or 18 is disposed upstream of the roll-shaped brush member 7b in the photosensitive member rotation direction. The arrangement of the rubbing member 17 or 18 proposed by the present invention is an aspect in contact with the roll-shaped brush member 7b as shown in FIGS. 3 (b) and 3 (d).

  The roll-shaped brush member 7b is formed in a roll shape by arranging a plurality of fibers on the outer peripheral surface of the shaft from the center toward the outer peripheral surface. The shafts are arranged in parallel to the tangent line with the photoreceptor 1, and the roll brush member 7 b can rotate around the shaft. The distance between each of the shafts and the photoreceptor 1 is a predetermined value (preferably 0.3 to 2.0 mm, more preferably 0.5 mm) with respect to the photoreceptor 1 at the brush tip of the roll-shaped brush member 7b. To 1.8 mm).

Examples of the fibers of the roll-shaped brush member 7b include resin fibers such as nylon, acrylic, polyolefin, and polyester, such as Beltron (manufactured by Kanebo), SA-7 (manufactured by Toray Industries, Inc.), UU nylon (manufactured by Unitika), and the like. Commercial products can be used. The thickness of these fibers is preferably 30 denier or less, more preferably 20 denier or less, and still more preferably 0.5 to 10 denier. The fiber density is preferably 20,000 fibers / inch ² or more, more preferably 60,000 fibers / inch ² or more.

  The bending elastic modulus of the collection roll member 7c is preferably 700 kPa or more. If the flexural modulus is less than 700 kPa, the recovery roll member 7c is bent, and it is difficult to maintain the contact position and the amount of biting with the brush member or the blade member at a predetermined value. In addition, if a material having a flexural modulus of less than 700 kPa is used to increase the thickness of the collecting roll member to maintain rigidity, molding shrinkage increases, resulting in insufficient dimensional accuracy, and further increases the weight. Costs increase due to problems such as an increase in molding time and the need for subsequent processes. In addition, a bending elastic modulus here says the value measured based on JISK7203. Moreover, since the collection | recovery roll member 7c is in a contact state with each of the roll-shaped brush member 7b and the scraper member 7d, the outer peripheral surface of the collection | recovery roll member 7c may be worn by the operation | movement.

  In the present invention, when the amount of wear is measured in accordance with JIS K6902 on the outer peripheral surface of the collection roll member 7c, the amount of wear is preferably 20 mg or less. Thereby, the contact pressure and the biting amount of the roll brush member 7b and the scraper member 7d can be set to a large value, and even in that case, stable cleaning can be performed over a long period of time. If the wear amount exceeds 20 mg, the life of the collection roll member 7c may be insufficient and frequent replacement may be necessary.

  Moreover, it is preferable that the Rockwell hardness (M scale) of the collection | recovery roll member 7c is 100 or more. When the Rockwell hardness is 100 or more, molding with high dimensional accuracy is possible, and the recovery roll member 7c is extremely strong against scraping. Here, the Rockwell hardness is a value measured according to JIS K7202.

  The scraper 7d is made of a thin metal plate, and is disposed so that an edge portion at one end thereof is in contact with the outer peripheral surface of the recovery roll member 7c. The other end of the scraper 7d is fixed to the housing 7 respectively, but the fixing method thereof is not particularly limited, and may be fixed using an attachment fitting or may be fixed directly to the housing 7.

  As a material of the scraper 7d, stainless steel or phosphor bronze is preferable from the viewpoint of high durability and low cost. The thickness of the scraper 7d is preferably 0.02 to 2 mm, more preferably 0.05 to 1 mm. A rubber blade member may be used instead of the scraper 7d.

  In the cleaning device 7 having the above configuration, first, residual toner after transfer is removed by the roll-shaped brush member 7b. Next, the residual toner is transferred to the contact position with the recovery roll member 7c by the rotation of the roll brush member 7b and recovered. As a result, the brush tip of the roll-shaped brush member 7b is regenerated and used repeatedly for cleaning the photoreceptor 1.

  The residual toner adhering to the collection roll member 7c is transferred to the contact position with the scraper 7d by the rotation of the collection roll member 7c and removed. Thereby, the surface of the collection roll member 7b is also regenerated and used repeatedly for regenerating the roll-shaped brush member.

  In the present invention, in order to electrostatically adsorb and remove the toner, a positive voltage having a polarity opposite to that of the toner is applied to the roll brush member 7b. It is preferable to adopt a mechanism for applying a cleaning bias having a potential difference between the member 7c and the member 7c.

  More specifically, by applying a predetermined voltage to the roll brush member 7b, the residual toner on the photoreceptor 1 can be attached to the roll brush member 7b by the electrostatic attraction force. The roll brush member 7b is preferably set so that the potential difference between the brush member and the photosensitive member is 100V or more. Then, by applying a voltage having an absolute value larger than the applied voltage to the roll brush member 7b and the same polarity to the collection roll member 7c, the residual toner adhering to the roll brush member 7b adheres to the collection roll member 7c. Can be made. The potential difference between the roll brush member and the collection roll member is preferably 100 V or higher, more preferably 200 V or higher, and still more preferably 400 V or higher.

<2. Rub member>
(2-a. Fine fiber member)
The rubbing members 17 and 18 of the present invention shown in FIG. 3 are preferably configured so that the pressing member holds a fine fiber member. In this case, the ultrafine fiber of 10 μm or less is in contact with the contact surface of the photoreceptor 1. It is desirable to have. The fine fibers have a thickness of 0.1 d to 1 d (d is a unit called denier: 2 to 10 μm), preferably 0.2 d to 0.5 d. The reason why fine fibers are preferable is as follows.

  The fine fibers as described above create a micro gap between the photosensitive member contact surface and easily maintain the toner remaining on the photosensitive member 1 in a dense manner, and thereby discharge products adhering to the surface of the photosensitive member 1 and External additives can be removed uniformly.

  When used as a fine fiber cloth, the material of the fiber is, for example, a polyester fiber, a nylon fiber, a polyamide fiber, a polyolefin fiber, an acrylic fiber, or a composite fiber using a resin of each of these synthetic fibers, an acetate type Semi-synthetic fibers such as fibers and regenerated fibers such as rayon are used.

  There are two methods for processing fibers into fabrics: a method in which yarns are knitted to form a two-dimensional material, and a method in which fabrics are made directly from fibers. The latter allows fibers to be bonded to each other or mechanically entangled. This is processed into a sheet shape, which is called a non-woven fabric. Although any method can be used for the member of the present invention, a nonwoven fabric is desirable in that the strength and density of the fabric is large and the flexibility is high, and the toner can be well held between the fibers.

(2-b. Pressing member)
Examples of the pressing member that holds the fine fiber member and presses the photosensitive member 1 include foaming urethane, urethane rubber, silicone rubber, and the like. The pressure at which the pressing member presses the fine fiber member against the photoreceptor 1 is preferably in the range of 0.5 to 6 gf / mm. A more preferable range is 1 to 4 gf / mm. If the pressing pressure is lower than 0.5 gf / mm, the sufficient rubbing function and charge adjusting function cannot be exhibited. If the pressing pressure is higher than 6 gf / mm, the rubbing with the photoconductor is too strong and the member itself and the photoconductor Degradation is caused, and filming and the like are induced.

  The pressing member can be a prismatic member as indicated by reference numeral 17 in FIG. 3, for example. In this case, one plane of the member is pressed against the photoreceptor 1. Further, a cylindrical member as indicated by reference numeral 18 can be used. Further, by installing this member so as to be rotatable, the rubbing member 18 is rotated along with the rotation of the photosensitive member 1, and the photosensitive member 1 is rotated. Since it is pressed against, the rubbing member 18 wears uniformly, which is preferable.

<3. Auxiliary Charging Device>
On the upstream side of the electrostatic brush cleaning device 7, an auxiliary charging device 8 for charging the residual toner before cleaning is disposed. The auxiliary charging device 8 before cleaning is composed of a wire and a shield. In this embodiment, a positive DC voltage is marked on the wire. Further, alternating current may be superimposed. Further, a pin corotron using a pin instead of a wire may be used. Since the resistance of the wire or pin changes due to adhesion of dust and toner components in the air during traveling, low current control is preferable. The total current value flowing through the wire or pin is preferably 100 μA to 600 μA. More preferably, it is 200 μA to 600 μA. If the current value is lower than 100 μA, the toner of the normal polarity supplied from the developing device cannot be completely made positive, and if it exceeds 600 μA, there is a problem that the life of the wire or pin is shortened.

In addition, in the case of using toner whose particle size distribution or charge amount distribution is originally broad, such as pulverized toner, in order to sharpen the toner charge amount distribution and facilitate brush cleaning, an AC voltage is superimposed on the corona charger. May be. AC electric field _{1.0kV P-P ~6.0kV P-P} , the range of 0.5kHz~9.0kHz is preferred. Outside this range, the effect of sharpening the charge amount does not appear.

<4. Developer>
The toner used in the image forming method of the present invention is not particularly limited by the production method. For example, a binder resin, a colorant, a release agent, and a charge control agent as necessary are kneaded, pulverized, and classified. A kneading and pulverizing method, a method of changing the shape of particles obtained by the kneading and pulverizing method by mechanical impact force or thermal energy, emulsion polymerization of a polymerizable monomer of a binder resin, and a formed dispersion; Emulsion polymerization aggregation method to obtain toner particles by mixing with a colorant, a release agent, and, if necessary, a dispersion of a charge control agent, agglomeration, heat fusion, polymerizable single amount to obtain a binder resin Suspension polymerization method in which a solution of body, colorant, release agent, and charge control agent, if necessary, is suspended in an aqueous solvent and polymerized, binder resin and colorant, release agent, charged as required Obtained by the dissolution suspension method in which a solution such as a control agent is suspended in an aqueous solvent and granulated It can be used. In addition, known methods such as a production method in which the toner obtained by the above method is used as a core, and agglomerated particles are further adhered and heat-fused to give a core-shell structure can be used. Suspension polymerization method, emulsion polymerization aggregation method, and dissolution suspension method, which are produced from an aqueous solvent, are preferred, and emulsion polymerization aggregation method is particularly preferred.

  The toner particles include a binder resin, a colorant, a release agent, and the like. If necessary, silica or a charge control agent may be used. The volume average particle diameter is preferably in the range of 2 to 12 μm, and more preferably in the range of 3 to 9 μm. Further, by using a toner having an average shape index (ML2 / A: ML is the absolute maximum length of toner particles, and A is the projected area of the toner particles) in the range of 100 to 145, high development and transferability are achieved. And high-quality images can be obtained. More preferably, it is 125-145. Even when such a toner having an average shape index of 125 to 145 is used, high cleaning performance can be maintained over a long period of time as described above.

  Binder resins used 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 acid esters such as methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate Examples of vinyl polymers such as vinyl methyl ether, vinyl ethyl ether, vinyl butyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, vinyl isopropenyl ketone; Particularly typical binder resins include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene- Mention may be made of maleic anhydride copolymers, 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 toner releasing agent include low-molecular polyethylene, low-molecular polypropylene, Fischer-Tropsch wax, montan wax, carnauba wax, rice wax, and candelilla wax. In addition, a charge control agent may be added to the toner as necessary. Known charge control agents can be used, but azo metal complex compounds, metal complex compounds of salicylic acid, and resin type charge control agents containing polar groups can be used. When the toner is manufactured by a wet manufacturing method, it is preferable to use a material that is difficult to dissolve in water in terms of controlling ionic strength and reducing wastewater contamination. The toner in the present invention may be either a magnetic toner containing a magnetic material or a non-magnetic toner containing no magnetic material.

  The toner can be added with inorganic fine particles, organic fine particles, composite fine particles obtained by adhering inorganic fine particles to the organic fine particles, etc. for the purpose of removing deposits and deteriorated substances on the surface of the electrophotographic photosensitive member. Excellent inorganic fine particles are particularly preferred. 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, octyltrimethoxy The treatment may be performed with a silane coupling agent such as silane, 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 styrene resin particles, styrene acrylic resin particles, polyester resin particles, and urethane resin particles. If the particle size is too small, the polishing ability is insufficient, and if it is too large, the surface of the electrophotographic photosensitive member is likely to be damaged. Therefore, the average particle size is in the range of 5 to 1000 nm, preferably 5 to 800 nm. A range, more preferably a range of 5 to 700 nm is used. Moreover, it is preferable that the sum with the addition amount of the said lubricous particle is 0.6 mass% or more.

  Other inorganic oxides added to the toner are small-diameter inorganic oxides having a primary particle size of 40 nm or less for powder flowability, charge control, etc. Mention may be made of large-diameter inorganic oxides. As these inorganic oxide fine particles, known ones can be used, but in order to perform precise charge control, it is preferable to use silica and titanium oxide in combination. Further, the surface treatment of the small-diameter inorganic fine particles increases the dispersibility and increases the effect of improving the powder fluidity.

  The toner in the present invention can be produced by mixing the toner particles and the external additive with a Henschel mixer or a V blender. In addition, when the toner particles are produced by a wet method, external addition can be performed by a wet method.

  In addition, when the toner in the present invention is used as a color toner, it is preferably used by mixing with a carrier. Examples of the carrier include iron powder, glass beads, ferrite powder, nickel powder, or the surface thereof. A resin coating is used. Further, the mixing ratio of the carrier and the toner can be set as appropriate.

<5. Charging means>
As a charging method used in the image forming apparatus of the present invention, a known charging method can be applied, and examples thereof include a corotron charging method and a contact charging method. In the contact charging method, a roller-shaped charging member, a blade-shaped charging member, a belt-shaped charging member, a brush-shaped charging member, a magnetic brush-shaped charging member, or the like can be applied. In particular, the roller-shaped charging member and the blade-shaped charging member may be arranged in contact with the photosensitive member or in a non-contact state having a certain amount of gap (100 μm or less).

A roller-shaped charging member, a blade-shaped charging member, and a belt-shaped charging member are composed of a material adjusted to an effective electrical resistance (10 ³ Ω to 10 ⁸ Ω) as a charging member, You may be comprised from several layers. Synthetic rubbers such as urethane rubber, silicone rubber, fluorine rubber, chloroprene rubber, butadiene rubber, EPDM, epichlorohydrin rubber, and elastomers such as polyolefin, polystyrene, vinyl chloride, etc. as the main materials, conductive carbon, metal oxide, An appropriate amount of a conductivity-imparting agent such as an ionic conductive agent can be blended in an appropriate amount to develop an effective electrical resistance as a charging member. Furthermore, a resin such as nylon, polyester, polystyrene, polyurethane, silicone, etc. is made into a paint, and an appropriate amount of any conductivity imparting agent such as conductive carbon, metal oxide, ionic conductive agent, etc. is blended there, and the resulting paint is dipped. They can be laminated and used by any method such as spraying or roll coating.

<6. Transfer means>
In addition, as a transfer unit used in the image forming apparatus of the present invention, a known transfer method can be applied. For example, a direct transfer method using a transfer corotron or a transfer roll, an intermediate transfer member such as an intermediate transfer belt or an intermediate transfer drum, or the like. And a transfer belt method in which a recording material is electrostatically attracted and conveyed to transfer an image on an image carrier.

<7. Photoconductor>
As shown in FIG. 2, the photoreceptor 1 includes at least a conductive support 11 and a photosensitive layer 12 formed on the conductive support 11, and if necessary, an undercoat layer 13 and a protective layer. Other layers such as 16 may be provided. The photosensitive layer 12 may be composed of only one layer, or may be a function-separated type photosensitive layer composed of a charge generation layer 14 and a charge transport layer 15. When the photosensitive layer is a function-separated type, it is preferable that the charge generation layer 14 and the charge transport layer 15 are laminated in this order from the conductive support side. Hereinafter, the photoreceptor 1 will be described with reference to FIG.

  FIG. 2 is a cross-sectional view showing an embodiment of the photoreceptor 1. 2 includes a conductive support 11, an undercoat layer 13, a charge generation layer 14, a charge transport layer 15, and a protective layer 16 in this order, and the charge generation layer 14 and the charge transport layer. 15 constitutes a photosensitive layer 12.

  Examples of the conductive support 11 include a metal plate, a metal drum, a metal belt using a metal or an alloy such as aluminum, copper, zinc, stainless steel, chromium, nickel, molybdenum, vanadium, indium, gold, platinum, or the like, or Examples thereof include paper, plastic film, belt, and the like coated, vapor-deposited, or laminated with a conductive polymer, a conductive compound such as indium oxide, or a metal or alloy such as aluminum, palladium, or gold. When the photoreceptor 1 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. Furthermore, since the coefficient of friction with the intermediate transfer member such as a blade cleaner or a transfer belt can be reduced by using the photosensitive member of the present invention, the rotation of the photosensitive member becomes smooth and image quality defects such as banding can be prevented. Furthermore, the load applied to the driving motor such as the photoconductor can be reduced, and the power consumption can be reduced. In addition, in order to prevent interference fringes generated when laser light is irradiated, the surface of the conductive support 11 has a center line average roughness Ra of 0.04 μm to 0. It is preferable to roughen to 5 μm. As a roughening method, wet honing is performed by suspending an abrasive in water and spraying it on a substrate, or centerless grinding in which a conductive support 11 is pressed against a rotating grindstone and grinding is performed continuously. Anodization and the like are preferable.

  If Ra is smaller than 0.04 μm, it becomes close to a mirror surface, so that the effect of preventing interference cannot be obtained. If Ra is larger than 0.5 μm, even if a coating film according to the present invention is formed, the image quality becomes rough, which is not suitable. When non-interfering light is used for the light source, it is not particularly necessary to roughen the interference fringes, and it is possible to prevent the occurrence of defects due to the unevenness of the surface of the base material, which is suitable for longer life.

  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. The treatment with an acidic treatment solution 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 support 11 can be performed by immersing it in pure water at 90 to 100 ° C. for 5 to 60 minutes or by contacting it 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.

  If desired, an undercoat layer 13 can be formed between the conductive support 11 and the photosensitive layer. Materials used for the undercoat layer 13 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, In addition to organoaluminum compounds such as aluminum coupling agents, 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 compound, aluminum zirconium alkoxide Compounds, organometallic compounds such as, in particular an organic zirconium compound, an organic titanyl compound, since the organic aluminum compound to residual potential indicates a satisfactory electrophotographic properties lower, are preferably used.

  Also, 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.

  Next, the charge transport layer 15 will be described. As the charge transport layer 15, a layer formed by a known technique can be used. The charge transport layer 15 is formed containing a charge transport material and a binder resin, or is 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. N means 1 or 2. Ar ₆ and Ar _{7 each} 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 and R ²⁰ represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, and Ar represents a substituted or unsubstituted aryl group. The substituent is a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a substituted amino group substituted with an alkyl group having 1 to 3 carbon atoms. Indicates.

In the formula, 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 are a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or 1 to 2 carbon atoms. An amino group substituted with an alkyl group, 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 and R ^{20 each} represents a hydrogen atom, a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, and Ar represents a substituted or unsubstituted aryl group. m and n are integers of 0-2.

（式中Ｒ^２１は水素原子、炭素数１〜５のアルキル基、炭素数１〜５のアルコキシ基、置換又は未置換のアリール基、または、―ＣＨ＝ＣＨ―ＣＨ＝Ｃ（Ａｒ）_２を表す。Ａｒは、置換又は未置換のアリール基を表す。Ｒ^２２、Ｒ^２３は同一でも異なってもよく、水素原子、ハロゲン原子、炭素数１〜５のアルキル基、炭素数１〜５のアルコキシ基、炭素数１〜２のアルキル基で置換されたアミノ基、置換又は未置換のアリール基を表す。）

(Wherein 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 15 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 -Vinylcarbazole, 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 (mass 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, the 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.

  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 the charge transport layer 15 is provided include aromatic hydrocarbons such as benzene, toluene, xylene and chlorobenzene, ketones such as acetone and 2-butanone, and halogenation such as methylene chloride, chloroform and ethylene chloride. Commonly used organic solvents such as aliphatic hydrocarbons, cyclic ethers such as tetrahydrofuran and ethyl ether, and straight chain ethers can be used alone or in admixture of two or more.

  The thickness of the charge transport layer 15 used in the present invention is 5 to 18 μm, preferably 10 to 15 μm. If the thickness of the charge transport layer is less than 5 μm, problems such as leakage are likely to occur, especially when a contact charger is used, and if the thickness is greater than 18 μm, the transfer history is likely to remain. It is not suitable for systems that require high image quality. As a method for controlling the film thickness of the charge transport layer, it is possible to adjust the coating speed and the viscosity when the constituent material is dissolved in a solvent.

  Additives such as antioxidants, light stabilizers, and heat stabilizers are added to the photosensitive layer to prevent photoconductor deterioration caused by 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, tracyanoethylene, 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 an electron-withdrawing substituent such as fluorenone, quinone, Cl, CN, and NO ₂ are particularly preferable.

  In the present invention, when the charge transport layer 15 is the outermost layer, the charge transport layer preferably contains fluororesin fine particles. By containing the fluororesin fine particles, there is an effect of reducing the friction of the photoreceptor when the photoreceptor does not have a protective layer. The content of the fluororesin fine particles in the charge transport layer 15 is preferably 0.1 to 40% by mass, more preferably 1 to 30% by mass, and further preferably 3 to 10% by mass with respect to the total amount of the charge transport layer 15. preferable. If the content is less than 0.1% by mass, the friction reducing effect due to the dispersion of the fluororesin fine particles is not sufficient particularly in combination with the contact charger. And the residual potential increases due to repeated use.

  The content of the fluororesin in the charge transport layer 15 in the high-speed black-and-white image forming photoreceptor is less than the content of the fluororesin in the charge transport layer 15 of the color photoreceptor and is preferably 3% by mass or less. The mass% or less is more preferable. When the amount is more than 3% by mass, the charge transfer speed tends to decrease during high-speed image formation.

  The fluororesin fine particles used in the present invention include tetrafluoroethylene resin, trifluoroethylene chloride resin, hexafluoropropylene resin, vinyl fluoride resin, vinylidene fluoride resin, difluorodiethylene chloride resin and their co-polymers. It is desirable to appropriately select one or two or more of the polymers, but particularly preferred are tetrafluoroethylene resin and vinylidene fluoride resin. The primary particle size of the fluororesin fine particles is preferably 0.05 to 1 μm, more preferably 0.1 to 0.5 μm. When the primary particle size is less than 0.05 μm, aggregation during dispersion tends to proceed. If it exceeds 1 μm, image quality defects are likely to occur.

  The photoconductor 1 is provided with a high-strength protective layer 16 as the outermost surface layer of the photoconductor 1 in order to give resistance to scratches on the surface. This makes it possible to extend the life of the photoreceptor. Hereinafter, the protective layer 16 will be described. As a material constituting the protective layer 16, at least a resin having a crosslinked structure is used in order to improve wear resistance and ensure sufficient hardness. If such materials are not used, the surface hardness is low and sufficient wear resistance cannot be obtained, so scratches and wear tend to progress, and when used at high speeds or for very long periods of time. When image formation is performed across the board, high quality image quality cannot be obtained.

  In addition to the resin having a crosslinked structure, the protective layer 16 may include a binder resin not having a crosslinked structure, conductive fine particles, a charge transporting material (compound having charge transporting ability), and fluorine as necessary. Lubricating fine particles made of a resin, an acrylic resin, or the like may be included. When forming the protective layer 16, a hard coat agent such as silicone or acrylic can be used as necessary.

  The details of the method for forming the protective layer 16 will be described later. For the formation of the protective layer 16, a coating solution for forming a protective layer containing at least a precursor constituting a resin having a crosslinked structure is used. In addition, as the resin having a crosslinked structure, various materials can be used from the viewpoint of ensuring the hardness of the protective layer 16; however, phenolic resins, urethane resins, siloxane resins, epoxy resins, and the like are mentioned in terms of characteristics. Among these, phenol resins and siloxane resins are preferable from the viewpoint of durability. More preferably, it is at least one selected from a phenol resin obtained by crosslinking a phenol derivative having a methylol group and a siloxane resin having a crosslinked structure.

  Furthermore, from the viewpoint of electrical characteristics, image quality maintenance, and the like, the resin having a crosslinked structure preferably has charge transportability (including a structural unit having charge transportability). In this case, the protective layer 16 can also function as a part of the charge transport layer 15 in the laminated structure type latent image carrier as shown in FIG. The structural unit having such charge transporting ability is preferably a charge transporting 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.

As a 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, the compounds represented by the following general formulas (I) to (V) or derivatives thereof are strong. It is particularly preferable because of its excellent stability.
F- [D-Si (R ¹ ) _(3-a) Q _a ] _b (I)

In formula (I), F represents an organic group derived from a compound having a hole transporting ability, D represents a divalent group having flexibility, R ¹ 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, -C α H 2α -,} - C β H 2β-2 -, - C γ H 2γ-4 - 2 divalent hydrocarbon group (here represented by, alpha is 1 to 15 Represents an integer, 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, the constituent atoms of these characteristic groups are substituted with other substituents. And the like. The hydrolyzable group Q is preferably an alkoxy group, more preferably an alkoxy group having 1 to 15 carbon atoms.
F-[(X ¹ ) _n1 R ² —ZH] _n2 (II)

In the above formula (II), F represents an organic group derived from a compound having a hole transporting ability, X ¹ represents an oxygen atom or a sulfur atom, R ² represents an alkylene group (the number of carbon atoms is preferably 1 to 15, preferably 1). 10 is more preferable), n1 represents 0 or 1, n2 represents an integer of 1 to 4, and ZH represents a hydroxyl group, a thiol group, an amino group, or a carboxyl group.
_{^{F - [(X 2) n3}} - (R 3) n4 - (Z) n5 G] n6 (III)

In the above formula (III), F is an organic group derived from a compound having a hole transporting ability, X ² is an oxygen atom or a sulfur atom, R ³ is an alkylene group (the number of carbon atoms is preferably 1-15, preferably 1 10 is more preferable), Z represents an oxygen atom, sulfur atom, NH or COO, G represents an epoxy group, n3, n4 and n5 each independently represents 0 or 1, and n6 represents an integer of 1 to 4. .

In the above formula (IV), F is an organic group derived from a compound having a hole transporting ability, T is a divalent group, Y is an oxygen atom or a sulfur atom, R ⁴ , R ⁵ and R ⁶ are Each independently represents a hydrogen atom or a monovalent organic group, R ⁷ represents a monovalent organic group, m 1 represents 0 or 1, and n ⁷ represents an integer of 1 to 4. However, R ⁶ and R ⁷ may combine with each other to form a heterocycle having Y as a heteroatom. Specific examples of T include an alkylene group having 1 carbon atom.

In the above formula (V), F represents an organic group derived from a compound having a hole transport ability, T represents a divalent group, R ⁸ represents a monovalent organic group, m2 represents 0 or 1, and n8 Represents an integer of 1 to 4, respectively. Specific examples of T include an alkylene group having 1 carbon atom.

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

Here, in the above 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 —D—Si (R ¹ ) _(3-a) Q _a , — (X ¹ ) in the compounds represented by the above formulas (I) to (V). ^{_{n1 R 2 -ZH, - (X}} 2) n3 - (R 3) n4 - (Z) n5 G, - (T) m1 -O-CR 4 (CHR 5 R 6) (Y-R 7), - ( T) It has a site represented by _m2 -OCOOR ⁸ and a bond. k represents 0 or 1.

  In the present invention, the protective layer contains a phenol derivative having a methylol group and a 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. It is preferable to do.

  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, and doroquinone. 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. Further, 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.

  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 transparency of the protective layer, the volume average particle diameter 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, silicone-based hard coating agents mainly produced 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 is made of a cyclic compound having a repeating structural unit represented by the following general formula (VII-3) or a compound thereof for extending pot life, controlling film properties, and improving the uniformity of the coating film surface. The derivative | guide_body can also be contained.

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. Silicone fine particles used as silicon atom-containing fine particles are spherical and preferably have a volume average particle diameter 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 and vinylidene fluoride, and “8th Polymer Material 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, as a hindered phenol type, a Sumizer BHT-R, a Summarizer MDP-S, a Summarizer BBM-S, a Summarizer WX-R, a Summarizer NW, a Summarizer BP-76, a Summarizer BP-101, a Summarizer GA-80, a Summarizer GM, Sumilizer GS (manufactured by Sumitomo Chemical Co., Ltd.), IRGANOX1010, IRGANOX1035, IRGANOX1076, IRGANOX1098, IRGANOX1135, IRGANOX1141, IRGANOX1222, IRGANOX1425WL, IRGAIRNOX2520L, IRGANOX2452 Upper Ciba Specialty Chemicals), ADK STAB AO-20, ADK STAB AO-30, ADK STAB AO-40, ADK STAB AO-50, ADK STAB AO-60, ADK STAB AO-70, ADK STAB AO-80, ADK STAB AO-330 (and above) Asahi Denka). Examples of hindered amines include Sanol LS2626, Sanol LS765, Sanol LS770, Sanol LS744 (manufactured by Sankyo Lifetech Co., Ltd.), Tinuvin 144, Tinuvin 622LD, Mark LA57, Mark LA67, Mark LA62, Mark LA68, Mark LA63, and Sumitizer Examples of TPS and thioethers include Sumilizer TP-D, and examples of phosphites include Mark 2112, Mark PEP · 8, Mark PEP · 24G, Mark PEP · 36, Mark 329K, and Mark HP · 10. Phenol and hindered amine antioxidants are preferred. 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 ; LiSO _4, metal sulfates MgSO ₄ and the like; phosphoric acid zirconium, phosphorus Metal phosphates such as lanthanum; coupled to on silica gel by reacting aminopropyltriethoxysilane containing an amino group such as the resulting solid which groups _{surface; LiNO 3, Mn (NO 3} ) 2 and the like of a metal nitrate Inorganic solids such as 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. 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 15, a curing process is performed. Usually, during the curing treatment, the curing temperature is higher and the curing time is longer in order to accelerate the crosslinking reaction of the phenol derivative and increase the mechanical strength of the protective layer.

100-190 degreeC is preferable, the curing temperature in the case of a hardening process has more preferable 110-170 degreeC, and 130-160 degreeC is further more preferable. The curing time is preferably 30 minutes to 2 hours, more preferably 30 minutes to 1 hour. Further, the atmosphere for performing the curing treatment (crosslinking reaction) is preferably a so-called oxidation inert gas atmosphere (inert gas atmosphere) such as nitrogen, helium, or argon. 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 (II), when the site represented by (— (X ¹ ) _n1 R ² —ZH) is —CH ₂ —OH, the influence of the electrical characteristics due to the curing temperature tends to be greatest. In addition, since it is sensitive to oxidation, it is preferable to perform 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 -Sulfonyloxyimides, pyridones such as (4-fluorobenzenesulfonyloxy) -3,4,6-trimethyl-2-pyridone, 2,2,2-trifluoro-1-trifluoromethyl-1- ( Photoacid generators such as sulfonic acid esters such as 3-vinylphenyl) -ethyl-4-chlorobenzesulfonate, onium salts such as triphenylsulfonium methanesulfonate, diphenyliodonium trifluoromethanesulfonate, protonic acid or Lewis acid And a mixture of Lewis acid and trialkyl phosphate, sulfonate esters, phosphate esters, onium compounds, carboxylic anhydride compounds, 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, ferrous 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, octylcobalt, zinc octylate, zirconium octylate, oct Le stannous, 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.

  Moreover, when using an organometallic compound as a catalyst when forming a protective layer, it is preferable to add a polydentate ligand from the surface of pot life and hardening 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 solution 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, the 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. The thickness of the protective layer is preferably from 0.1 to 5 μm, more preferably from 1 to 5 μm.

  The dielectric layer (the sum of the thicknesses of the charge transport layer and the protective layer) used in the present invention is 5 to 18 μm, preferably 10 to 15 μm. If the film thickness is thicker than 18 μm, it is easy to receive a transfer history, and if an auxiliary charger that gives negative charge is not provided, it is not suitable for a system such as a color machine that requires high image quality. On the other hand, when the thickness is less than 5 μm, problems such as leakage are liable to occur particularly when a contact charger is used.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example at all. In the following description, “parts” means “parts by weight” unless otherwise specified.

1. Development of developer [Manufacture of toner base particles]
(Adjustment of resin fine particle dispersion)
A mixture of 370 g of styrene, 30 g of n-butyl acrylate, 8 g of acrylic acid, 24 g of dodecanethiol and 4 g of carbon tetrabromide was dissolved in 6 g of a nonionic surfactant (Nonipol 400, manufactured by Sanyo Chemical Co., Ltd.) Ion in which 10 g of anionic surfactant (Neogen SC, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) is emulsion-polymerized in a flask dissolved in 550 g of ion-exchanged water, and 4 g of ammonium persulfate is dissolved in this while slowly mixing for 10 minutes. 50 g of exchange water was added. After carrying out nitrogen substitution, the inside of the flask was stirred and heated in an oil bath until the content reached 70 ° C., and emulsion polymerization was continued for 5 hours. As a result, a resin fine particle dispersion in which resin particles of 150 nm, Tg = 58 ° C., and weight average molecular weight Mw = 11500 were dispersed was obtained. The solid content concentration of this dispersion was 40% by weight.

(Adjustment of colorant dispersion (1))
Carbon black (Mogal L, manufactured by Cabot): 60g
Nonionic surfactant (Nonipol 400, Sanyo Chemical Co., Ltd.): 6g
Ion exchange water: 240g
The above components are mixed, dissolved, stirred for 10 minutes using a homogenizer (Ultra Turrax T50, manufactured by IKA), then dispersed with an optimizer (color black (carbon black) having an average particle size of 250 nm) ) Colorant dispersant (1) in which particles were dispersed was prepared.

(Adjustment of colorant dispersion (2))
Cyan pigment B15: 360 g
Nonionic surfactant (Nonipol 400, Sanyo Chemical Co., Ltd.): 5g
Ion exchange water: 240g
The above components are mixed, dissolved, and stirred for 10 minutes using a homogenizer (Ultra Turrax T50, manufactured by IKA), then dispersed with an optimizer (Cyan pigment having an average particle size of 250 nm). ) A colorant in which particles were dispersed was dispersed to prepare a colorant dispersant (2).

(Adjustment of colorant dispersion (3))
Magenta pigment R122: 60 g
Nonionic surfactant (Nonipol 400, Sanyo Chemical Co., Ltd.): 5g
Ion exchange water: 240g
The above components are mixed, dissolved, stirred for 10 minutes using a homogenizer (Ultra Tarrax T50, manufactured by IKA), then dispersed with an optimizer (Colorant pigment having a mean particle size of 250 nm) ) Colorant dispersant (3) in which particles were dispersed was prepared.

(Adjustment of colored dispersion (4))
Yellow pigment Y180: 90 g
Nonionic surfactant (Nonipol 400, Sanyo Chemical Co., Ltd.): 5g
Ion exchange water: 240g
The above components are mixed, dissolved, stirred for 10 minutes using a homogenizer (Ultra Tarrax T50, manufactured by IKA), and then dispersed with an optimizer to give a colorant having an average particle size of 250 nm (Yellow pigment) ) A colorant dispersant (4) in which particles were dispersed was prepared.

(Release agent dispersion)
Paraffin wax (HNP0190, manufactured by Nippon Seiwa Co., Ltd., melting point 85 ° C.): 100 g
Cationic surfactant (Sanisol B50, manufactured by Kao Corporation): 5 g
Ion exchange water: 240g
The above components were dispersed in a round stainless steel flask using a homogenizer (Ultra Turrax T50, manufactured by IKA) for 10 minutes, and then dispersed with a pressure discharge type homogenizer, so that the average particle size was 550 nm. A release agent dispersion in which the mold agent particles were dispersed was prepared.

<Adjustment of toner mother particle K>
Resin fine particle dispersion (prepared during preparation of composite fine particles): 234 parts Colorant dispersion (1): 30 parts Release agent dispersion: 40 parts Polyaluminum hydroxide (manufactured by Asada Chemical Co., Paho2S): 0. 5 parts Ion-exchanged water: 600 parts The above components were mixed and dispersed in a round stainless steel flask using a homogenizer (Ultra Turrax T50, manufactured by IKA), and then the inside of the flask was heated in an oil bath for heating. Heat to 40 ° C. with stirring. After maintaining at 40 ° C. for 30 minutes, it was confirmed that aggregated particles having a D50 of 4.5 μm were produced. Further, the temperature of the heating oil bath was raised and maintained at 56 ° C. for 1 hour, and D50 was 5.3 μm. Thereafter, 26 parts by weight 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 the dispersion containing the aggregate particles and 1N sodium hydroxide to adjust the pH of the system to 7.0, the stainless steel flask is sealed and heated to 90 ° C. while continuing to stir using a magnetic seal. And held for 2 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 had a D50 of 5.8 μm and an average shape factor SF of 130.

<Adjustment of toner base particle C>
Toner mother particles C1 were obtained in the same manner as K1 except that the colored particle dispersion (2) was used instead of the colored particle dispersion (1). The toner base particles C1 had a D50 of 5.9 μm and an average shape factor SF of 131.

<Adjustment of toner base particle M>
Toner mother particles M1 were obtained in the same manner as K1 except that the colored particle dispersion (3) was used instead of the colored particle dispersion (1). The toner base particles M1 had a D50 of 5.7 μm and an average shape factor SF of 130.

<Adjustment of toner base particle Y>
Toner mother particles Y1 were obtained in the same manner as K1 except that the colored particle dispersion (4) was used instead of the colored particle dispersion (1). The toner base particle Y1 had a D50 of 5.9 μm and an average shape factor SF of 131.

K1, C1, M1, and Y1 are used as toner base particles, and 1 part of metatitanic acid (average primary particle size 40 nm, i-butyltrimethoxysilane treatment), silica (average) as an external additive with respect to 100 parts by weight of toner. 1.5 parts of primary particle size 12 nm, dimethyldimethoxysilane treatment, vapor phase oxidation method) and spherical fine particles shown in Table 1 are added to K1, C1, M1, and Y1, and a peripheral speed of 30 m / s × is measured with a 5 L Henschel mixer. After blending for 15 minutes, coarse particles were removed using a sieve having an opening of 45 μm, and developers (toners) 1 to 5 having different external additive compositions shown in Table 1 were obtained. The cross-linked acrylic (resin) of spherical fine particles 1 and spherical fine particles 2 in Table 1 means methyl methacrylate / 1,1,1-trimethylolpropane trimethacrylate. The average particle diameters of the spherical fine particles 1 and the spherical fine particles 2 are 75 nm and 180 nm, respectively, and the shape factors SF ′ are 112 and 118, respectively. Further, the spherical fine particles 3 (SiO ₂ ) are obtained by subjecting silica sol obtained by the sol-gel method to HMDS (hexamethyldisilazane) treatment, drying and pulverizing, to obtain a specific gravity of 1.50, an average particle diameter of 140 nm, and a shape factor SF. 'Is 106 spherical monodisperse silica. In addition, the average particle diameter and shape factor SF ′ of these spherical fine particles were obtained using FE-SEM as described above. The addition amount shown in Table 1 is weight% with respect to the toner.

2. Creation of carrier and developer [Manufacture of carrier]
Ferrite particles (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 The above components other than the above 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. The carrier was obtained by depressurizing while heating and degassing and drying. This carrier had a volume resistivity of 10 ¹¹ Ωcm when an applied electric field of 1000 V / cm.

  Further, 100 parts of the carrier and 6 parts of the toner were stirred with a V-blender at 40 rpm × 20 minutes, and sieved with a sieve having an opening of 212 μm to obtain a developer using each color toner.

3. Creation of photoconductor [Photoconductor 1]
The constituent materials shown below were dissolved in 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) was added, and the mixture was stirred at room temperature for 24 hours. Decomposition was performed. The constituent materials are as follows.
Compound shown in Chemical Formula 9 below: 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

0.1 parts of aluminum trisacetylacetonate (Al (aqaq) ₃ ) and 3,5-di-t-butyl-4-hydroxytoluene (BHT) are obtained by filtering and separating the ion exchange resin from the hydrolyzed product. ) 0.4 part is added, and this coating solution is applied onto the charge transport layer of the base photoreceptor by a ring-type dip coating method, air-dried at room temperature for 30 minutes, and then cured by heat treatment at 140 ° C. for 1 hour. A surface layer having a thickness of about 3 μm was formed. This is a photoreceptor 1.

[Photoreceptor 2]
2 parts of the compound shown in the chemical formula 10 below and 2 parts of Resist Top PL4852 (manufactured by Gunei Chemical Co., Ltd.) were dissolved in 10 parts of isopropyl alcohol to obtain a coating solution for forming a protective layer. This coating solution for forming a protective layer is dip-coated on the charge transport layer prepared under the same conditions as the photoreceptor 1, air dried at room temperature for 30 minutes, and then dried at 150 ° C. for 60 minutes to form a protective layer having a thickness of 3 μm. did. The obtained photoreceptor is designated as photoreceptor 2.

4). The evaluation machine / evaluation condition tester was based on a Fuji Xerox DCC500 machine and incorporated the following cleaning device. All of the cleaning devices are process cartridges.

<Cleaning device>
The following cleaning apparatus having the configuration shown in FIG. 3 was used.
(1) Roll-shaped brush member Brush material 1: Conductive nylon fiber thickness: 2 denier Electric resistance: 1 × 10 ⁸ Ω
Hair length: 2.5mm
Fiber density: 120,000 / inch ²
Biting into the photoreceptor: approx. 0.75mm
Peripheral speed: 60mm / s
Rotation direction: reverse direction of brush applied bias with respect to rotation direction of photoconductor: + 260V

Brush material 2: Conductive nylon fiber Thickness: 17 denier Electrical resistance: 1 × 10 ⁸ Ω
Hair length: 2.5mm
Fiber density: 120,000 / inch ²
Biting into the photoreceptor: approx. 0.75mm
Peripheral speed: 60mm / s
Rotation direction: reverse direction of brush applied bias with respect to rotation direction of photoconductor: + 260V

(2) Material of recovery roll member: phenol resin electric resistance in which conductive carbon is dispersed: 1 × 10 ⁸ Ω
Flexural modulus (JIS K7203): 100 MPa
Abrasion amount (JIS K6902): 2mg
Rockwell hardness (JIS K7202, M scale): 120
Biting amount into brush member: 1.0mm
Peripheral speed: 70mm / s
Rotation direction: Same direction as brush rotation direction Applied bias: + 660V

(3) Scraper material: SUS304
Thickness: 80μm
Biting amount into collection roll member: 1.2 mm
Free length (free length): 8.0 mm.

(4) Auxiliary corona charger wire: Tungsten (φ60)
Shield material: SUS (plate thickness 0.5mm)
Applied voltage: AC: 0.7 kHz / 3.2 kV _PP (constant voltage), DC-200 μA (constant current)

(5) Rub member The following two types of non-woven fabrics were used for the fine fiber member in the rub member.
Non-woven fabric 1: Product name: WP8085 / manufactured by Japan Vilene Co., Ltd., material: polyester / nylon, fiber thickness: 6 μm
Nonwoven fabric 2: Product name: 830CR / manufactured by Nippon Bayleen Co., Ltd., material: cellulose fiber, fiber thickness: 20 μm

The following members were used as the pressing member that holds the fine fiber member.
Pressing member 1: Urethane foam pressing member 2 having a width of 5 mm and a height (biting direction with respect to the photoconductor) 2: Cylindrical non-woven fabric is wound around a foamed urethane sponge roll of φ12, and the amount of biting into the photoconductor It was installed at 1 mm (pressing load 2.5 g / mm). Further, it was rotated in the same direction with respect to the photoreceptor so that the peripheral speed ratio with the photoreceptor becomes 0.6.

  In order to confirm the effect of the present invention, the positional relationship between the rotating roller and the rubbing member was set in the pattern shown in FIG. 3 (FIGS. 3A and 3C show that the rubbing member and the roll-shaped brush member are A separated state, (b) and (d) are in contact).

<Evaluation method>
The cleaning devices of Examples 1 to 4 and Comparative Examples 1 and 2 configured as shown in Table 2 for each component of the above-described cleaning device are manufactured, and the conditions are low and low humidity (10 ° C., 20% RH) and high temperature and high Durability running test of 200,000 sheets in total (100,000 sheets each under humidity (28 ° C, 80%) and conditions, and measurement of cleaning properties, image blurring, filming, photoconductor scratches and photoconductor wear. It was. The criteria for determining each characteristic value are shown below.

[Cleanability]
The cleaning property of the toner was evaluated as follows. After a durability test of a total of 400,000 sheets, after flowing three A3-sized solid images under low temperature and low humidity, a halftone image (image density of 30%) was flowed, and a drop-off cleaning defect appearing on the halftone was observed. .
(Double-circle): The drop-off state cleaning defect does not occur.
◯: A slight drop-off cleaning defect was observed on the first halftone image after three A3 size solid images, but not on the second halftone image.
X: Obvious drop-off cleaning failure is observed on the first halftone image after three A3 size solid images, and is also seen on the second halftone image.

[Image blur]
Image blur is 100,000 sheets under low-temperature and low-humidity (10 ° C, 20% RH) and 100,000 sheets under high-temperature and high-humidity (28 ° C, 80%), and then a halftone image (image density 30%). An evaluation was made based on whether the image was printed (O) or not (X).

[Filming]
In filming, as with image blur, after running 100,000 sheets under low temperature and low humidity (10 ° C, 20% RH) and 100,000 sheets under high temperature and high humidity (28 ° C, 80%), halftone images (image density) 30%) was printed and evaluated based on whether it occurred (◯) or not (×).

[Photoconductor scratches]
The photoreceptor scratches were evaluated by measuring 10-point average roughness (Rz) with a surface roughness meter (Surfcom 1400A, manufactured by Tokyo Seimitsu Co., Ltd.) after running 200,000 sheets. Judgment criteria are as follows.
A: Rz is 1.5 μm or less.
○: Rz exceeds 1.5 μm and is less than 2.5 μm (a level at which there is no problem in image quality).
X: Rz is 2.5 μm or more (white streaks appear on the image).

[Photoconductor wear]
Regarding the wear of the photoreceptor, the film thickness of the photoreceptor before and after the running test was measured with an eddy current film thickness meter, and the difference was judged. The values shown in Table 3 indicate the amount of wear per 1000 revolutions.

  As shown in Table 3, in Examples 1 and 2, the other items for which photoconductor abrasion occurred were generally good as ◯ to ◎, and the overall evaluation was ◯. Further, in Examples 3 and 4, the other items were also ◯ to ◎ while suppressing photoreceptor wear, and the overall evaluation was ◎. However, in Comparative Example 2, photoconductor abrasion and photoconductor scratches were suppressed, but the other items were x, and in Comparative Example 1, all items were x.

  It is possible to provide an image forming apparatus capable of suppressing image deterioration even after long-term use.

1 is a schematic view of an image forming apparatus used for electrophotographic formation. FIG. 2 is an enlarged cross-sectional view of a photoreceptor surface in an image forming apparatus. It is a schematic diagram which shows the arrangement | positioning aspect of the rubbing member in a cleaning apparatus, Comprising: (a) And (c) is a conventional arrangement | positioning aspect, (b) And (c) shows the arrangement | positioning aspect of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electrophotographic photoreceptor, 11 ... Conductive support, 12 ... Photosensitive layer, 13 ... Undercoat layer, 14 ... Charge generation layer, 15 ... Charge transport layer, 16 ... Protective layer, 17 ... Rubbing member (pressing member) 1), 18 ... rubbing member (pressing member 2), 2 ... charging device, 2a ... contact-type charger, 3 ... exposure device, 4 ... developing device, 5 ... transfer device, 6 ... intermediate transfer belt, 7 ... Cleaning device, 7b ... roll brush member, 7c ... collecting roll member, 7d ... scraper member, 8 ... auxiliary charger, 9 ... exposure pre-cleaning device

Claims (5)

A photosensitive member; a latent image forming unit that forms an electrostatic latent image on the photosensitive member; a developing unit that develops the electrostatic latent image; and a toner image developed on the photosensitive member is transferred to a transfer target. Transfer means for cleaning, and cleaning means for cleaning the toner remaining on the surface of the photoconductor after the toner image is transferred to the transfer object,
The cleaning means is composed of at least a conductive brush that is in contact with the surface of the photoreceptor and is applied with a voltage, and a recovery means that contacts the conductive brush and collects toner, and further the photoreceptor. A rubbing member having a fine fiber member is disposed on the surface of the photoreceptor upstream of the conductive brush with respect to the rotation direction, and the rubbing member is disposed at a position in contact with the conductive brush. An image forming apparatus.   The image forming apparatus according to claim 1, wherein the conductive brush has a fiber thickness of 10 denier or less, and the fine fiber member has a fiber thickness of 10 μm or less.   3. The rubbing member includes a pressing member having elasticity for attaching the fine fiber member, and a surface thereof is pressed against the photoconductor with a predetermined pressure. The image forming apparatus described in 1.   The rubbing member is a fine fiber rotating roller formed by coating a cylindrical cloth made of a fine fiber member on the surface of the pressing member in the form of a roll, and the fine fiber rotating roller rotates the photoreceptor. The image forming apparatus according to claim 1, wherein the image forming apparatus rotates in a direction that is a forward direction.   The image forming apparatus according to claim 1, wherein the outermost surface layer of the photoreceptor contains a resin having a structural unit having a charge transporting ability and having a crosslinked structure.

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