JP2008129401A - Image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming method by which a clear image free from image deletion is obtained under high temperature and high humidity conditions even if a drum heater is not used in a copying machine or printer equipped with an a-Si photoreceptor, and high image quality is maintained over a long period of time by satisfying all of image deletion resistance, excellent cleaning property and durability of a cleaning member. <P>SOLUTION: A digital image forming method uses an a-Si photoreceptor 101 and includes a cleaning step, wherein the cleaning step has a step 110 of rubbing a surface of the photoreceptor 101 through abrasive powder M comprising perovskite-type crystals having an average particle diameter of 50-500 nm, and a covering step 111 of applying and spreading a covering agent S on the surface of the photoreceptor 101. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotating image carrier, a charging step for charging the image carrier, a latent image forming step for forming a latent image on the charged image carrier, and a latent image as a developer image by a developer. The present invention relates to an image forming method including a developing step of developing and a transferring step of transferring a developer image to a recording medium.

  In the above, the image carrier is an electrophotographic photosensitive member or an electrostatic recording dielectric. The recording medium is a recording material such as transfer paper or a belt-type or drum-type intermediate transfer member.

  In recent years, digital electrophotographic apparatuses such as laser printers have attracted attention because of their good image quality and high-speed printout.

  In particular, an electrophotographic apparatus using an amorphous silicon photoconductor (a-Si photoconductor) is preferable in terms of high sensitivity, high stability, and high durability, a long maintenance interval, and a reduction in running cost.

  On the other hand, miniaturization, high productivity, and energy saving are advancing as the needs of the electrophotographic apparatus market. Even in an electrophotographic apparatus using a highly durable photoconductor, it is desired to reduce the diameter or speed of the photoconductor and to remove temperature control means such as an environmental heater (no drum heater). .

  In a digital electrophotographic apparatus using a highly durable photoconductor represented by an a-Si photoconductor, a method of scraping the charged product together with the surface layer like a conventional organic photoconductor (OPC) cannot be used. For this reason, in particular, when there is no drum heater, there is a case where an image defect such as a so-called image flow occurs in which an image is blurred in a high humidity environment.

  Further, in reducing the diameter of the a-Si photosensitive member or increasing the speed of the electrophotographic apparatus using the a-Si photosensitive member, the time from the neutralization step to the main charging step is shortened between processes, Since an excessive current is required, the image flow deteriorates as the discharge product increases. Further, in the downsizing, the image flow may be deteriorated due to the narrowing of the space around each unit or the photoconductor.

  As a method for solving these problems, an a-Si photosensitive member using a toner surface-treated with two kinds of titanium oxide fine particles defining the average particle diameter and specific resistance of primary particles and a cleaning roller made of polyurethane foam is used. A method of polishing the surface has been proposed (Patent Document 1).

  Further, as a response to localized output (repeated localized output patterns such as ruled lines), a static elimination light source is provided on the upstream side of the cleaning means including a magnetic brush member and a cleaning blade. As a result, a method has been proposed in which the electrostatic force of transfer residual toner is weakened and the waste toner is re-supplied from the magnetic brush to the surface of the photosensitive member (Patent Document 2).

  In addition, as a method that takes into account the rubbing of the surface of the photosensitive member and the charging stability, a neutralization unit is provided upstream of the cleaning unit, and injection charging is performed between the cleaning unit and the neutralization unit. A method using an auxiliary charging means has been proposed (Patent Document 3).

  Further, a method has been proposed in which a developer containing an abrasive that defines an average particle diameter and an electric resistance value is used, and an auxiliary charging member made of an elastic roller is used (Patent Document 4).

  In recent years, from the viewpoint of energy saving, drum heaters are not required. On the other hand, sleep or printing immediately after power-on has become the mainstream of market needs. In particular, when a so-called corona charging method such as scorotron is employed, a high humidity flow may occur during image formation after standing for a long time. A method of applying a protective agent made of a fatty acid metal salt or the like has been proposed as a suppression of deterioration of the photoreceptor surface due to this charging (Patent Document 5).

An example in which an abrasive and a lubricant are used in combination is also proposed (Patent Document 6).
JP 2005-017524 A Japanese Patent Laid-Open No. 10-049017 Japanese Patent Laid-Open No. 2003-091142 JP 2001-042734 A Japanese Patent Laying-Open No. 2005-115311 Japanese Patent Laying-Open No. 2005-165090

  However, in the method of Patent Document 1, since a sponge roller is used, when the localized output pattern such as ruled lines is repeated, there is a case where the polishing force is uneven due to the difference in the image ratio.

  The method of Patent Document 2 is insufficient as a countermeasure against image flow.

  In the method of Patent Document 3, since injection charging is used as auxiliary charging, an additional device such as a high-voltage power supply needs to be added, and the cost is unavoidable.

  In the configuration of Patent Document 4, the polishing force may be uneven as in Patent Document 1. JP-A-2001-005256 is cited as another document similar to Patent Document 4.

  The method of Patent Document 5 has been proposed with a focus on reducing wear due to charging of the surface of the photoconductor. Originally, an image flow when using a photoconductor having a long life, and further for suppressing the flow. The required application amount of the protective agent and the disclosure regarding the removal of the protective agent are insufficient. . Other documents similar to Patent Document 5 include Japanese Unexamined Patent Application Publication No. 2004-341480, Japanese Unexamined Patent Application Publication No. 08-202226, Japanese Unexamined Patent Application Publication No. 2004-309939, and Japanese Unexamined Patent Application Publication No. 2004-109754.

  Japanese Patent Application Laid-Open No. H10-260260 particularly seeks a function and effect as a lubricant in the cleaning section, and these are also insufficiently disclosed for the flow. Other documents similar to Patent Document 6 include JP-A-2005-091979, JP-A-2004-053892, JP-A-2004-037734, and JP-A-2003-140382.

  An object of the present invention is to solve the problems of the prior art as described above. Specifically, image formation that maintains and maintains a cleaning property that can satisfactorily remove charged products from the image carrier over a long period of time, prevents image defects such as image flow, and maintains stable image characteristics at a high level. It aims to provide a method.

  In order to achieve the above object, a typical configuration of the image forming method according to the present invention includes a rotated image carrier, a charging step for charging the image carrier, and a latent image in the charged image carrier. An image forming method comprising: a latent image forming step for forming an image; a developing step for developing the latent image as a developer image with a developer; and a transfer step for transferring the developer image to a recording medium. A rubbing step of rubbing the surface of the image carrier through abrasive particles made of inorganic fine particles having an average particle diameter D of 30 to 500 nm between the step and the charging step, and covering the surface of the image carrier And a coating step of applying and spreading the agent.

  As a result of the study by the present inventors, in particular, in an image bearing member with a small amount of wear and a long life, in order to suppress the image flow and maintain high image quality over a long period of time, a coating agent is almost applied to the surface of the image bearing member. Apply evenly. Further, it has been found that it is effective to appropriately remove the coating layer of the coating agent to which the charged product has adhered and apply a new coating agent. Furthermore, the present inventors have found that the required amount of the coating agent depends on the surface shape (roughness) of the image carrier.

  That is, a coating agent that is easy to apply, spread, and remove on the surface of the image carrier is used to prevent the charged product from directly depositing on the surface of the image carrier, and the coating layer to which the charged product has adhered is properly polished. Image removal can be prevented by removing with an agent.

  Even when an a-Si photosensitive member having excellent wear resistance is used as the image carrier, the charged product can be scraped off satisfactorily and image flow can be prevented.

  In addition, it is possible to make the polishing force and the load on the cleaning blade uniform when repeatedly used (so-called printing durability) with an output of a localized image or an image with extremely low density. As a result, it is possible to prevent the image from flowing, maintain good cleaning properties, and suppress wear of the cleaning blade and the image carrier.

  By defining the correlation between the surface shape of the image bearing member and the particle size of the abrasive, it is possible to improve the fluidity, particularly in the longitudinal direction, mainly in the cleaning process if the charged product is polished and removed with high efficiency.

  By defining the correlation between the surface roughness of the image bearing member and the coating amount of the coating agent, the coating agent can be applied and spread within the optimum range, thereby suppressing flow and achieving both high image quality and long life.

  By adopting a magnetic one-component development system that is a non-contact development system, it is possible to suppress the recovery of abrasive particles in the development process and the accompanying deterioration in development characteristics. Further, not only the abrasive particles but also the rubbing effect on the surface of the image carrier due to the high-hardness magnetic toner is superimposed.

  By providing the proximity charging method and the abrasive particle recovery process, the life of the system including the image carrier, the cleaning unit, and the charging unit can be extended, and the maintenance load can be reduced.

  Hereinafter, the present invention will be described in detail.

<Configuration of image forming apparatus>
FIG. 1 shows an embodiment of an image forming apparatus using the image forming method of the present invention. The image forming apparatus includes a drum-type electrophotographic photosensitive member (hereinafter referred to as a photosensitive member) 101 as an image carrier that is rotationally driven in the X direction (clockwise) at a predetermined speed. The rotating photoconductor 101 is uniformly charged to a predetermined polarity and potential by a charging means (main charging means) 102 (charging process). Next, image information is exposed to the uniformly charged surface by the image exposure means 103, and an electrostatic latent image corresponding to the exposure image information is formed on the surface of the photoreceptor 101 (latent image forming step). . Next, the electrostatic latent image is visualized as a developer image by the developer in the developing unit 104 (development process). The developer image is sequentially electrostatically transferred to a recording material (transfer material) P as a recording medium in a transfer portion which is a facing portion between the photoconductor 101 and the transfer unit 108 (transfer process). The recording material P is fed from a paper supply unit (not shown) at a predetermined control timing, and is introduced into the transfer unit by the registration unit 112 at a predetermined control timing. The recording material P that has passed through the transfer portion is separated from the surface of the photosensitive member 101 (separation step), and is introduced into a fixing unit (not shown) by the conveying unit 109. The fixing unit fixes the unfixed developer image on the recording material P as a fixed image on the surface of the recording material P by heat, heat and pressure, or pressure (fixing step). The recording material P that has undergone image fixing is output as an image formed product. The surface of the photosensitive member 101 after separation of the recording material is subjected to surface treatment by a post-processing unit 105, and further subjected to charge removal processing by a charge removal unit 107 such as an eraser lamp, and repeatedly used for image formation.

  The post-processing means 105 has a rubbing means 110 for rubbing the surface of the photoreceptor 101 through inorganic fine particles M as abrasive particles (abrasive) in the cleaning container 105a (rubbing step). Alternatively, it has a rubbing means 110 for rubbing the surface of the photoreceptor 101 through the inorganic fine particles M and further collecting excess inorganic fine particles. As will be described later, the inorganic fine particles M are particles having an average particle diameter D of 30 to 500 nm, more preferably 100 to 300 nm.

  The transfer residual developer (toner) remaining on the surface of the photoconductor 101 after separation of the recording material in the transfer portion is removed from the surface of the photoconductor 101 in the process of rubbing and collecting inorganic fine particles M against the surface of the photoconductor by the rubbing means 110. It is scraped off and stored in the waste toner portion in the cleaning container 105a.

  Further, the post-processing means 105 has a coating material applying means 111 for applying and spreading the coating material S on the surface of the photoreceptor 101 (coating process). The application unit 111 is located downstream of the rubbing unit 110 in the rotation direction of the photosensitive member 101.

  By applying the coating material S, which is easy to apply, spread and remove on the surface of the photoconductor 101, by the coating unit 111, the charging unit 102 and the transfer unit 108 generate the charge directly on the surface of the photoconductor. An object can be prevented from adhering. Further, the image layer can be prevented by removing the coating layer on the surface of the photosensitive member to which the charged product is adhered by rubbing with the inorganic fine particles M by the rubbing means 110. Even when an a-Si photoconductor having excellent wear resistance is used as the photoconductor 101, the charged product can be scraped well, and the image flow can be prevented.

  In the image forming apparatuses of FIGS. 1 to 5, 7, and 9, both the charging unit 102 and the transfer unit 108 use a corona discharger that is a non-contact charging unit.

  In the image forming apparatus shown in FIGS. 6, 8, and 10, both the charging unit 102 and the transfer unit 108 use a charging roller that is a contact charging type.

  The image forming apparatus shown in FIGS. 11 and 13 uses a proximity charging type electrode plate or an electrode roller as the charging unit 102, and a contact charging type charging roller as the transfer unit 108. In the proximity charging, a dischargeable area determined by the voltage between the gap and the correction Paschen curve is ensured between the charging member to which the charging bias is applied and the member to be charged, and a small gap (gap) of, for example, several tens of μm exists. This is a charging method in which the object to be charged is charged in a non-contact manner.

  The image exposure unit 103 is, for example, a laser scanning exposure unit. Other digital exposure apparatuses using a combination of a light source such as an LED array or fluorescent light and a liquid crystal shutter may be used. Analog exposure means such as an image imaging projection optical apparatus may be used. In the digital image forming method, there are roughly two types of electrostatic latent image forming methods depending on the relationship between the image information and the exposure unit. One is a background exposure method (back exposure method: BAE, Back Area Exposure) in which a non-image portion (background portion) of image information is exposed on the surface of the charged photoreceptor 101. The other is an image exposure method (IAE, Image Area Exposure) in which an image portion is exposed on the surface of a charged photoreceptor 101. The BAE method employs a regular development method that develops portions other than the exposed background portion. In contrast, the IAE method employs a reversal development method in which a non-exposed portion is developed.

  In the case where the image carrier is an electrostatic recording dielectric, an electrostatic latent image is formed by selectively eliminating the charge on the surface to be charged by a discharging means such as a discharging needle or an electron gun.

  The developing unit 104 may be a regular developing unit or a reversal developing unit. Generally, electrostatic latent image development methods using toner are roughly classified into four types: a one-component non-contact development method, a one-component contact development method, a two-component contact development method, and a two-component non-contact development method. Is done. In the one-component non-contact developing method, non-magnetic toner is applied onto a developer carrying / conveying member such as a sleeve with a blade or the like, or magnetic toner is applied onto the developer carrying / conveying member by a magnetic force. In this method, the electrostatic latent image is developed in a non-contact state. The one-component contact development method is a method for developing an electrostatic latent image by applying the nonmagnetic toner or magnetic toner applied on the developer carrying member as described above in contact with the image carrier. The two-component contact development method is a method of developing an electrostatic latent image by using a two-component developer in which toner and a magnetic carrier are mixed, transported by a magnetic force, and applied in contact with an image carrier. The two-component non-contact developing method is a method for developing an electrostatic latent image by applying the above two-component developer to the image carrier in a non-contact state.

  Regarding the charge eliminating unit 107, the image forming apparatuses in FIGS. 9 to 11 and 13 are arranged between the transfer unit 108 and the post-processing unit 105.

  4 to 11 and 13, the post-processing unit 105 includes a blade cleaning unit (blade cleaning step). That is, the cleaning blade 106 is disposed in contact with the surface of the photoconductor 101 as a cleaning unit for the photoconductor 101, and the surface of the photoconductor is cleaned by the cleaning blade 106. Between the transfer step and the blade cleaning step, there are the rubbing step and the covering step or the rubbing step or the covering step.

  7 to 11 and 13, the functions of both the rubbing unit 110 and the coating unit 111 are shared by the same unit 111.

<< Coating agent S and coating means 111 >>
The coating agent S needs to be applied substantially over the entire surface of the photoconductor in order to prevent the charge generating material generated by the charging means 102 and the like from directly attaching to the surface of the photoconductor 101. In addition, the coating material S adheres to the charged product and lowers the resistance similarly to the surface of the photoreceptor in a high humidity environment, so it needs to be removed as appropriate. Furthermore, since it is applied to the outermost surface of the photoreceptor, it functions as a window material (translucent member) that transmits each light such as latent image exposure and static elimination light and reaches the photoreceptor, and charging and development. It is also necessary not to disturb other processes such as transfer and cleaning.

  Therefore, as a so-called disposable surface layer, the coating agent S is required to have a film formation ease (soft and easy to spread), an easy scraping, a transparency of the film, and an appropriate resistance.

  Examples of the coating agent S include materials such as fluororesins, fatty acid metal salts, and silicone oils because of these physical properties. Of these, fatty acid metal salts, particularly zinc stearate, are preferable because they are excellent in the above-mentioned properties and easy to process into a solid state.

  As a method for applying the coating agent S to the surface of the photoreceptor 101, a powdery, liquid, or powdery material may be processed into a solid and directly applied, or a separate application member may be provided. . In the case of a gaseous state, it can be supplied by spraying or the like. A form in which the coating member is processed into a solid state is preferable because maintenance and space saving of the coating material S and control of the coating amount are easy.

  As the application member, an appropriate member such as an elastic member such as a fur brush or a sponge, a magnetic brush, or a blade shape can be used. In particular, when considering a long-life system, it is preferable to use a magnetic brush. The magnetic brush has a fluidity in the longitudinal direction (photoreceptor axial direction), is excellent in uniform coating, and has been put into practical use as an auxiliary cleaning means in an image forming apparatus using amorphous silicon as a photoreceptor. It is also effective from the viewpoint of long life.

Good results were obtained when the fur brush was a 0.56-3.33 tex (5D-30D) fur brush. If it is less than 0.56 tex, the coating action may not be maintained for a long time due to wear or deformation of the fur. Further, when it exceeds 3.33 tex, the photoreceptor may be worn out or unevenly coated. Both tex (text) and D (denier) are units indicating the thickness (fineness) of the fiber. Conventionally, D is commonly used in the textile industry, but the official SI unit of fineness is kg / m, and tex is a provisional combined unit. The correlation is 9D = 1 tex = 1 g / km = 1 × 10 ⁻⁶ kg / m.

  The elastic member preferably has an Asker C hardness of 5 to 30 °. In the case of a hard elastic member exceeding 30 °, uneven coating or wear of the photoreceptor may occur. Further, in the case of an elastic member having a low hardness of less than 5 °, durability may be deteriorated, for example, the elastic member may be damaged or the outer diameter may be changed.

  As the magnetic brush, a magnet roller or a sleeve-like member including a magnetic body having an appropriate magnetic particle coat thickness regulating member can be used. Also, known magnetic particles can be used. The magnetic particle coat thickness has a good range in which both the fluidity and the coating ability of the magnetic particles are compatible, and specifically, several hundred μm to several mm. Further, the magnetic flux density, the magnetic susceptibility of the magnetic particles, and the like are adjusted in an appropriate range from the coat thickness, coating ability, magnetic fluidity, and the like.

  These application members are driven with a relative speed difference with respect to the surface of the photoreceptor. Further, especially after being left for a long period of time, the charged product may accumulate due to the standing. It is also preferable to drive the coating member at a speed different from that at the time of normal image formation, for example, to improve the rubbing property by increasing the relative speed difference before the image formation after the standing.

  As a driving condition of the coating member, the relative speed [%] with respect to the surface speed of the photosensitive member is approximately -100 to + 200%, although it depends on the physical properties of the material of the coating member, the surface speed of the photosensitive member, the penetration pressure, and the like. It is a range. A range excluding -10 to + 10% and +90 to + 110% of approximate rotation is preferable.

  As for the relative speed [%], + is the forward direction with respect to the rotation direction of the photoconductor, − is the counter direction. For example, + 100% is a state where the photoconductor is rotated, 0% is a stop state, and −100% is a stop state. , Refers to the state of rotating in the counter direction at the same speed as the photoreceptor surface speed. The difference in relative speed is preferably large, but if it is too large, the member may be worn out.

  On the other hand, when the application member is blade-shaped, it is preferable from the viewpoint of simplifying the coating material application means. As the blade-shaped application member, the same material as that of the cleaning blade 106 can be used. In particular, it is preferable to widen the contact nip width with the photoreceptor or increase the contact pressure because of rubbing and recovery. Since the blade-shaped application member is not mainly intended for toner cleaning, installation conditions can be selected, such as setting an obtuse angle to the photoreceptor.

<< Inorganic fine particles M >>
The inorganic fine particles as abrasive particles (abrasive) for rubbing and removing the above-mentioned coating containing the charged product adhering to the surface of the photoreceptor 101 preferably have an average particle diameter D of 30 to 500 nm. . More preferably, it is 100 nm-300 nm. When the particle size is in this range, it has a sufficient rubbing / polishing action, is excellent in fluidity, and is suitable for uniform rubbing / polishing in the longitudinal direction.

  In the system having the blade cleaning means (FIGS. 4 to 11 and 13), the inorganic fine particles M effectively prevent the image flow in the wedge-shaped region or nip immediately adjacent to the nip between the cleaning blade 106 and the photosensitive member 101, Also acts as a cleaning blocking layer or lubricant. As a result, it is possible to maintain good cleaning properties, suppress wear of the cleaning blade 106 and the photosensitive member 101, and obtain a good image over a long period of time.

  In the case of inorganic fine particles having a small particle diameter of 30 nm or less, the rubbing / polishing action may be reduced. In addition, the uniformity of rubbing by the rubbing / collecting means may be reduced. On the other hand, in the case of inorganic fine particles having a large particle diameter exceeding 500 nm, the photoconductor 101 coated with the coating material S is difficult to be microscopically uniformly rubbed, and so-called rough cutting may occur. . Further, in the system having the blade cleaning means, it is difficult to enter the vicinity of the nip between the cleaning blade 106 and the photosensitive member 101, particularly a wedge-shaped portion, and a sufficient rubbing action may not be obtained. Further, the wedge-shaped portion, and further, the penetration of the cleaning blade 106 and the photosensitive member 101 into the nip portion becomes non-uniform in the longitudinal direction of the nip portion, and the cleaning blade 106 or the photosensitive member 101 may be worn out.

  Furthermore, the inorganic fine particles M are preferably inorganic fine particles having a perovskite crystal structure.

  Examples of the material having a perovskite crystal structure include strontium titanate and calcium titanate. These particles are practically used as an abrasive in electrophotography, and the particle size can be controlled relatively easily.

  About the average particle diameter of inorganic fine particles, 100 particle diameters were measured from the photograph image | photographed with the magnification of 50,000 with the electron microscope, and the average was calculated | required. The particle size was determined as (a + b) / 2, where a is the longest side of the primary particles and b is the shortest side.

  Further, when the inorganic fine particles are added to the developer, the liberation ratio to the toner particles is preferably 20% by volume or less, and more preferably 15% by volume or less.

  Here, the liberation rate is obtained by determining the ratio of perovskite crystal inorganic fine particles released from toner particles in volume%. Specifically, a known principle ("Japan Hardcopy 97 papers" pages 65-68 by a particle analyzer (PT1000: manufactured by Yokogawa Electric Corporation) (publisher: Electrophotographic Society, issue date: July 9, 1997) Day)).

  More specifically, the liberation rate is defined as a value obtained by the following formula 1 from the simultaneous emission of light of carbon atoms, which are constituent elements of the binder resin, and light of constituent atoms of the perovskite crystal inorganic fine particles.

Release rate (volume%) = “A / (B + A)] × 100 Formula 1
A: Phosphor with only constituent atoms of perovskite-type crystalline inorganic fine particles B: Constituent atoms of perovskite-type crystalline inorganic fine particles emitting simultaneously with carbon atoms
The light emission volume of the light emission volume B is “emitted simultaneously with carbon atoms” is 2.6 msec. From the light emission of carbon atoms. The emission of constituent atoms of the perovskite crystalline inorganic fine particles emitted within. Thereafter, the light emission of the constituent atoms of the perovskite crystal inorganic fine particles is the light emission of only the constituent atoms of the perovskite crystal inorganic fine particles.

  In the present invention, the light emission of the constituent atoms of the perovskite-type crystalline inorganic fine particles emitted simultaneously with the carbon atoms is measured by the perovskite-type crystalline inorganic fine particles adhering to the toner particle surface. The light emission from only the constituent atoms of the perovskite crystal inorganic fine particles means that the perovskite crystal inorganic fine particles released from the toner particles are measured, and the liberation rate is obtained using these.

  The shape of the inorganic fine particles may be indefinite, but a shape having a ridgeline or a corner, specifically a polygonal shape or a rectangular parallelepiped shape is preferable. It is preferable that the content of particles having a ridge line or corner in the perovskite crystal inorganic fine particles is 50% by number or more because the charged product can be more efficiently removed.

  For example, the circularity is preferably 0.930 or less. More preferably, it is 0.870-0.930. This indicates a polygonal shape or a rectangular parallelepiped shape as shown in FIG. 14 (SEM photograph), for example.

  By using inorganic fine particles having a particle diameter and circularity as described above, the surface of the photoreceptor can be rubbed uniformly and efficiently, and the coating agent to which the charged product is adhered can be suitably removed. In particular, in a system having blade cleaning means, the inorganic fine particles are likely to be present in the immediate vicinity of the contact nip between the cleaning blade 106 and the photosensitive member 101, which is effective in maintaining cleaning properties and suppressing wear of the cleaning blade 106.

  As for the circularity of the inorganic fine particles, an enlarged image of the inorganic fine particles taken with an electron microscope at 50000 times is taken into a computer. Then, with the software “analySIS” manufactured by Soft Imaging System, the circumference of the same circle as the particle projection area and the circumference of the particle projection image were calculated, and the circularity was calculated by the following equation.

Circularity = (perimeter of the same circle as the particle projection area) / (perimeter of the particle projection image)
The object data was obtained by randomly extracting 200 samples from inorganic fine particle images (abrasive agent images) of 30 to 500 nm obtained from the images, and the average value was calculated.

  The inorganic fine particles of perovskite crystals can be produced by a known sintering / pulverization method. The rectangular parallelepiped fine powder is prepared by adding strontium hydroxide to a titania sol dispersion obtained by adjusting the pH of a hydrous titanium oxide slurry obtained by hydrolyzing a titanyl sulfate aqueous solution. It can be synthesized by heating to temperature. By setting the pH of the hydrous titanium oxide slurry to 0.5 to 1.0, a titania sol having good crystallinity and particle size can be obtained.

  For the purpose of removing ions adsorbed on the titania sol particles, an alkaline substance such as sodium hydroxide is preferably added to the dispersion of the titania sol. At this time, it is preferable that the pH of the slurry is not 7 or higher so that sodium ions and the like are not adsorbed on the surface of the hydrous titanium oxide. The reaction temperature is preferably 60 ° C. to 100 ° C., and in order to obtain a desired particle size distribution, the temperature rising rate is preferably 30 ° C./hour or less, and the reaction time is preferably 3 to 7 hours.

  Examples of the method for subjecting the inorganic fine particles produced by the above method to surface treatment with a fatty acid or a metal salt thereof include the following methods. For example, fatty acid can be deposited on the perovskite crystal surface by placing the inorganic fine particle slurry in an aqueous solution of fatty acid sodium under Ar gas or N 2 gas atmosphere. In addition, for example, in an Ar gas or N 2 gas atmosphere, the inorganic fine particle slurry is placed in a fatty acid sodium aqueous solution, and the desired metal salt aqueous solution is dropped while stirring to precipitate and adsorb the fatty acid metal salt on the perovskite crystal surface. be able to. For example, if a sodium stearate aqueous solution and aluminum sulfate are used, aluminum stearate can be adsorbed.

<< Photoreceptor 101 >>
In order to reduce the maintenance load of the image forming system, the photosensitive member 101 is preferably a long-life photosensitive member.

  The a-Si photoreceptor (amorphous silicon photoreceptor) is a long-life photoreceptor excellent in wear resistance and potential stability accompanying durability.

  The surface layer of the a-Si photosensitive member is made of a non-single crystal material containing a hydrogen atom, a halogen atom, a hydrogen atom, or a halogen atom with a surface layer of a silicon atom and a carbon atom or a silicon atom or a carbon atom as a base.

  FIG. 15 is a schematic configuration diagram for explaining an example of a layer configuration of an a-Si photosensitive member. In the photoreceptor 1500, a photosensitive layer 1502 is provided on a support 1501. The photosensitive layer 1502 includes a photoconductive layer 1503, a surface layer 1504, and charge injection blocking layers 1505 and 1506 provided as necessary. Each layer is a known a-Si photosensitive material and plasma CVD. It can be created by a known manufacturing method.

  In the present invention, the photoconductor as the image carrier is preferably a photoconductor having a prescribed surface shape.

  As the 10-point average roughness Rz of the surface of the photoreceptor, the average particle diameter D of the inorganic fine particles is 0.5 in order for the inorganic fine particles M to flow effectively or to loosen aggregates such as the inorganic fine particles. It is preferably ˜2 times (0.5 ≦ Rz / D ≦ 2.0).

  If the Rz / D is too large, the inorganic fine particles cannot effectively flow. On the other hand, if the particle size is too small, the inorganic fine particles are hardly rolled.

  Further, it has been found that the surface shape of the surface of the photosensitive member particularly affects the image flow. In particular, when the surface roughness Ra of the photoreceptor surface increases, the flow tends to deteriorate. Further, the present inventors have found that the required coating amount of the coating agent for suppressing the image flow depends on the surface roughness Ra.

Specifically, the surface roughness Ra of the photoreceptor surface is 0.01 μm or more and 0.100 μm or less (Kosaka / macroscopic roughness). The coating amount of the surface roughness Ra and the coating amount per unit area in the coating contact area with the surface of the photosensitive member in the coating step (when the photosensitive member advances 1 cm per 1 cm in the longitudinal direction of the coating) A range where T [μg / cm ² ] satisfies the following formula is preferable.

T ≧ 0.61 × Ra + 0.064
The surface shape of the a-Si photosensitive member can be controlled by forming the photosensitive layer 1502 after adjusting the surface shape of the supporting member 1501 by, for example, cutting the supporting member 1501 or processing with a rotating ball mill or the like. .

  Specifically, the surface shape of the support can be controlled by adjusting the type, angle, or cutting pitch of the cutting tool when cutting the support 1501 such as an aluminum cylinder. Further, the manufactured a-Si photosensitive member has a surface shape corresponding to the surface shape of the support 1501 as shown in FIG. Furthermore, it is possible to control the surface shape by polishing the surface of the prepared photoreceptor using a polishing tape or the like. Further, it depends on the flow rate of the raw material gas at the time of forming the a-Si photosensitive layer, the film discharge conditions such as the plasma discharge power and the substrate temperature. For example, in the case of manufacturing by plasma CVD, when the source gas flow rate is increased and the discharge power / source gas flow rate ratio is increased, Rz and Ra tend to increase.

  These methods for controlling the surface shape may be controlled independently or in combination.

  The above-mentioned photoreceptor surface shape (Rz, Ra) can be measured with a surface roughness measuring device corresponding to JISB0601: 1994.

  Specifically, using a surf coder SE-3400 manufactured by Kosaka Laboratory (manufacturer), measuring length l = 5 mm, speed 0.05 mm / sec, cutoff λc 0.8 mm, JIS 1994 mode, longitudinal direction of cleaning blade The measurement was performed in the direction corresponding to.

《BAE method and IAE method》
As described above, in the digital image forming method, the latent image forming method is roughly classified into an IAE method (image exposure method) and a BAE method (background exposure method) depending on the relationship between the image information and the exposure unit. The BAE method is the same as the analog image forming method and uses a so-called regular development method, while the IAE method employs a reversal development method in which the photoconductor and the developer have opposite polarities.

  FIG. 17 shows the state of one line of the IAE system on the left side, that is, the light beam ON state for only one line, and the state of one line of the BAE system on the right side, that is, the latent image state of only one line with the light beam OFF. And the DC component of the developing bias.

  The solid line is the photoreceptor surface potential during the development process. The developing bias is Vdi in the IAE system and Vdb in the BAE system.

  The developer is developed on the surface of the photoreceptor by electrostatic adhesion, and the electrostatic adhesion is caused by contrasts of ΔVl1 = Vdi−Vi and ΔVh1 = Vb−Vdb, respectively.

  In other words, in the one-line portion of FIG. 17, in the IAE system, the developer tends to adhere more strongly as the potential well of the photoreceptor is deeper or the photoreceptor is lower in potential. On the other hand, in the BAE system, the higher the potential peak of the photoconductor, or the higher the potential of the photoconductor, the stronger the adhesion.

  When the surface potential of the photoconductor attenuates and becomes in the state shown by the broken line, the adhesive force of the developer is reduced in the BAE method, so that the developer can easily move in the longitudinal direction of the photoconductor in the cleaning process. The residual transfer developer, abrasive particles and the like are evenly leveled by the cleaning blade. It is also effective that the potential difference between the image area and the non-image area is reduced as the photoreceptor potential is attenuated.

  In the embodiment system of the present invention, since the charge removal process is passed before entering the cleaning process, the potential difference between the image area and the non-image area is further reduced at the time of the cleaning process, as shown by the dashed line in FIG. It works more effectively with the BAE method. In particular, the a-Si photosensitive member is more effective because the potential attenuation is larger than that of OPC or the like.

  Furthermore, as a result of the study by the present inventors, particularly in a system using an a-Si photoreceptor, in a short time such as 100 msec or less from the static elimination process to the charging process, An image defect called a ghost may occur.

  In a system in which the time from the cleaning process to the charging process is 100 msec or less, it is possible to lengthen the time from the charge eliminating process to the charging process by arranging the charge eliminating process upstream from the cleaning process. It is effective.

  In the IAE method, the non-image portion (background portion) has a higher potential than the image portion. Therefore, the transfer separation performance is wider in the BAE method than in the IAE method, and the BAE method is advantageous in this respect.

<Developer>
A known developer can be used as the developer. In particular, in a high-speed and long-life system, it is preferable that the developing means is also maintenance-free, and the jumping development method, which is a non-contact magnetic one-component development method, is practically used in an a-Si photoreceptor image forming apparatus. It has become.

  Since jumping development is non-contact development, even if the inorganic fine particles M as the abrasive described above slip through from the cleaning process or the like, it is difficult to collect them in the developing means, and the inorganic fine particles in the developing means It is possible to prevent fluctuations in image characteristics due to concentration of the liquid. Further, since the toner is a magnetic toner, additional actions such as addition of a polishing action by the magnetic substance and use of the magnetic substance as a rubbing recovery member can be expected.

  The magnetic one-component developer is a developer composed of magnetic toner particles and an external additive. The particle diameter of the magnetic toner particles is preferably smaller from high image quality and high definition. On the other hand, if it is too small, toner cleaning may be difficult. In general, when the toner particle size is small, the contribution ratio of the electrostatic adhesive force to the adhesive force is small, and it is preferable that the toner is not too small from the viewpoint of the effect of the BAE method.

  The toner particles preferably have a weight average particle diameter X (μm) of 4 μm to 12 μm.

  Further, the average circularity of toner particles having an equivalent circle diameter of 3 μm or more and 400 μm or less measured by a flow type particle image measuring apparatus is 0.930 or more and less than 0.970 (preferably 0.935 or more and less than 0.970). Is preferred.

  The higher the average circularity a, the better the releasability. That is, the adhesive force can be reduced, which is advantageous for cleaning performance and also improves the transfer efficiency. On the other hand, when the degree of circularity is too high, such as a spherical shape, the fluidity at the cleaning blade portion is reduced, and the action of uniformly leveling the inorganic fine particles as the abrasive in the longitudinal direction of the cleaning blade is reduced. . As a result, the effect of the inorganic fine particles and a decrease in cleaning properties may be caused.

  The circularity is an index of the degree of unevenness of the toner particles, and indicates 1.00 when the toner is a perfect sphere, and the circularity becomes smaller as the surface shape becomes more complicated.

  The average circularity is used as a simple method for quantitatively expressing the shape of particles. In the present invention, measurement is performed in an environment of 23 ° C. and 60% RH using a flow type particle image analyzer FPIA-2100 manufactured by Sysmex Corporation. Particles having a circle-equivalent diameter of 0.60 μm to 400 μm are measured, and the circularity a ′ of the measured particle is determined by the following formula 2. For particles having an equivalent circle diameter of 3 μm or more and 400 μm or less, a value obtained by dividing the sum of the circularity a ′ by the total number of particles is defined as an average circularity a.

Circularity a ′ = L0 / L Expression 2
In Equation 2, L0 represents the circumference of a circle having the same projection area as the particle image, and L is the particle projection image when image processing is performed at an image processing resolution of 512 × 512 (pixels of 0.3 μm × 0.3 μm). The perimeter of is shown.

  As a specific measuring method, 10 ml of ion-exchanged water from which impure solids have been removed in advance is prepared in a container, and a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant therein, followed by further measurement. Add 0.02 g of sample and disperse uniformly.

  As a means for dispersion, an ultrasonic disperser “Tetora 150 type” (manufactured by Nikka Ki Bios Co., Ltd.) is used, and dispersion treatment is performed for 2 minutes to obtain a measurement dispersion. In that case, it cools suitably so that the temperature of this dispersion may not be 40 degreeC or more. In order to suppress variation in circularity, the installation environment of the apparatus is controlled to 23 ° C. ± 0.5 ° C. so that the in-machine temperature of the flow type particle image analyzer FPIA-2100 is 26 to 27 ° C. Then, automatic focus adjustment is performed using 2 μm latex particles at regular intervals, preferably every 2 hours.

  To measure the circularity of the toner particles, the flow type particle image measuring device is used, and the concentration of the dispersion is readjusted so that the toner particle concentration at the time of measurement is 3000 to 10,000 particles / μl. Measure more than one. After the measurement, data having an equivalent circle diameter of less than 3 μm is cut using this data, and the average circularity of the toner particles is obtained.

  In the circularity distribution based on the number of circularity a ′, it is preferable that 90% by number or more of particles having a circularity a ′ of 0.900 or more are present. The effect of controlling the average circularity works effectively, and the above cleaning property and uniformity in the longitudinal direction of the cleaning blade can be suitably maintained.

  For the production of the magnetic toner particles, a known method such as a known pulverization method or polymerization method can be used. As the production means, a known device can be used for any of a mixer, a kneader, a pulverizer, a classifier, and a sieving device. The degree of circularity can also be controlled by using a known mechanical type or surface modification means by heat, or by adjusting the polymerization conditions. Also, well-known materials can be used as additives such as binder resin, magnetic material, and wax used for toner particles, and additives added externally to toner particles.

<Charging method>
As the charging method of the photosensitive member, a known charging method such as a corona charging method, a contact charging method, or a so-called proximity charging method located between these can be used.

  The charging bias to be applied may be a DC bias alone or an AC bias superimposed on the DC bias (referred to as AC / DC).

  In general, the contact charging method and the proximity charging method generate less products such as ozone and NOx than the corona charging method. The contact and proximity charging method is excellent in charging performance in a small size, and is effective in downsizing the image forming apparatus.

  In the proximity charging method, the surface of the charging member is hardly contaminated with a bias almost equal to that of contact charging and is not in contact with the photosensitive member, and further, an air flow is generated between the photosensitive member and the charging unit, thereby generating charge. Objects are difficult to accumulate in the charged area.

  In the proximity charging method, the gap between the photosensitive member and the charging unit is 500 μm or less, preferably 20 to 300 μm, more preferably 100 μm or less, and most preferably 50 μm or less at the closest portion, and the distance from the photosensitive member is A distinction from large (several mm) corona charging.

  If this gap is too large, the charging tends to become unstable, and if it is too small, the surface of the charging member may be contaminated when there are abrasive particles remaining on the photoreceptor. There is sex.

  The shape of the charging means 102 for proximity charging is, for example, as shown in FIGS. 11 and 12 (1) and 12 (2), in which the electrode member as the proximity charging means 102 is fixed in the state of being close to the photoreceptor 101. Alternatively, it may be a roller or a belt-like movable member as shown in FIG. A member such as a spacer can be provided outside the image area of the charging unit 102 so that a gap with the photoreceptor can be maintained. Although a well-known material can be used for the proximity charging member, it is generally set to a higher hardness than the contact charging means. Any hardness that can maintain the voids is acceptable.

  In particular, in the case of the movable type, it is possible to substantially increase the surface area, and it is easy to extend the life of the member or to provide a cleaning means.

<< Sliding and collecting means 110 for inorganic fine particles M >>
As the above-mentioned abrasive particles, the surface of the photoreceptor 101 is rubbed through the inorganic fine particles M, and / or the rubbing / recovering means 110 for collecting the inorganic fine particles M is appropriately selected from a fur brush, an elastic member, a magnetic brush, and the like. The member of the form can be used.

  The system having the blade cleaning means is effective in reducing the load on the cleaning blade 106 and suppressing wear.

  The rubbing / recovering means 110 can use the same member as the coating agent applying means 111 described above.

  In order to collect the inorganic fine particles M in these rubbing / collecting members, it is also preferable to apply a bias having a polarity opposite to that of the inorganic fine particles M.

《Examples of manufacturing inorganic fine particles》
In the following production example, perovskite-type crystalline inorganic fine particles made of strontium titanate as abrasive particles were prepared.

1) Production Example 1
Hydrous titanium oxide obtained by hydrolysis by adding ammonia water to an aqueous solution of titanium tetrachloride is washed with pure water, and 0.3% sulfuric acid is added to the hydrous titanium oxide slurry as SO3 with respect to the hydrous titanium oxide. did.

  Next, hydrochloric acid was added to the hydrous titanium oxide slurry to adjust the pH to 0.6 to obtain a titania sol dispersion. NaOH was added to the titania sol dispersion, the pH of the dispersion was adjusted to 5.0, and washing was repeated until the electrical conductivity of the supernatant liquid reached 50 μS / cm.

0.97-fold molar amount of Sr (OH) ₂ .8H ₂ O was added to the hydrous titanium oxide, and the mixture was placed in a SUS reaction vessel and purged with nitrogen gas. Furthermore, distilled water was added so as to be 0.6 mol / liter in terms of SrTiO ₃ . The slurry was heated to 60 ° C. at a rate of 10 ° C./hour in a nitrogen atmosphere, and reacted for 7 hours after reaching 60 ° C. After the reaction, the reaction solution was cooled to room temperature, and the supernatant was removed. Then, the washing was repeated with pure water, and then filtered with Nutsche. The obtained cake was dried to obtain strontium titanate fine particles not passing through the sintering step.

  The strontium titanate fine particles were designated as inorganic fine particles A. Table 1 shows the physical properties of the inorganic fine particles A.

2) Production Example 2
The hydrous titanium oxide obtained by hydrolysis by adding aqueous ammonia to an aqueous titanium tetrachloride solution is washed with pure water, and 0.25% sulfuric acid is added to the hydrous titanium oxide slurry as SO _{3 with} respect to the hydrous titanium oxide. Added. Next, hydrochloric acid was added to the hydrous titanium oxide slurry to adjust the pH to 0.65 to obtain a titania sol dispersion. NaOH was added to the titania sol dispersion, the pH of the dispersion was adjusted to 4.7, and washing was repeated until the electrical conductivity of the supernatant reached 50 μS / cm.

A 0.95-fold molar amount of Sr (OH) ₂ .8H ₂ O was added to the hydrous titanium oxide, and the mixture was placed in a SUS reaction vessel and purged with nitrogen gas. Further, distilled water was added so as to be 0.6 mol / liter in terms of SrTiO ₃ .

  The slurry was heated to 65 ° C. at a rate of 10 ° C./hour in a nitrogen atmosphere, and reacted for 8 hours after reaching 65 ° C. After the reaction, the mixture was cooled to room temperature, the supernatant was removed, and washing was repeated with pure water.

  Further, in a nitrogen atmosphere, the slurry is put into an aqueous solution in which 2% by mass of sodium stearate is dissolved with respect to the solid content of the slurry, and while stirring, an aqueous magnesium sulfate solution is dropped, and magnesium stearate is deposited on the perovskite crystal surface. Was precipitated.

  The slurry was washed repeatedly with pure water and then filtered with Nutsche, and the resulting cake was dried to obtain strontium titanate fine particles whose surface was treated with magnesium stearate.

  The surface-treated strontium titanate fine particles that have not passed through the sintering step are referred to as inorganic fine particles B. Table 1 shows the physical properties of the inorganic fine particles B.

3) Production Example 3
The inorganic fine particle C which consists of a strontium titanate fine particle was adjusted with respect to the said manufacture example 2 by adjusting the quantity and pH of the sulfuric acid to add, slurry temperature rising temperature, and reaction time. Table 1 shows the physical properties of the inorganic fine particles C.

4) Production Example 4
The hydrous titanium oxide slurry obtained by hydrolyzing the aqueous titanyl sulfate solution was washed with an alkaline aqueous solution. Next, hydrochloric acid was added to the hydrous titanium oxide slurry to adjust the pH to 0.7 to obtain a titania sol dispersion. NaOH was added to the titania sol dispersion, the pH of the dispersion was adjusted to 5.0, and washing was repeated until the electrical conductivity of the supernatant reached 70 μS / cm.

A 0.98-fold molar amount of Sr (OH) ₂ .8H ₂ O was added to the hydrous titanium oxide, placed in a SUS reaction vessel, and purged with nitrogen gas. Furthermore, distilled water was added so as to be 0.5 mol / liter in terms of SrTiO ₃ . The slurry was heated to 80 ° C. at a rate of 7 ° C./hour in a nitrogen atmosphere, and reacted for 6 hours after reaching 80 ° C. After the reaction, the reaction solution was cooled to room temperature, and the supernatant was removed. Then, the washing was repeated with pure water, and then filtered with Nutsche. The obtained cake was dried to obtain strontium titanate fine particles not passing through the sintering step.

  The strontium titanate fine particles were designated as inorganic fine particles D. Table 1 shows the physical properties of the inorganic fine particles D.

  Moreover, the photograph image | photographed by the magnification of 50,000 times with the electron microscope of this inorganic fine particle D is shown in FIG. In FIG. 14, rectangular parallelepiped strontium titanate fine particles having an average primary particle diameter D of 100 nm can be seen.

5) Production Example 5
The hydrous titanium oxide slurry obtained by hydrolyzing the aqueous titanyl sulfate solution was washed with an alkaline aqueous solution. Next, hydrochloric acid was added to the hydrous titanium oxide slurry to adjust the pH to 0.8 to obtain a titania sol dispersion. NaOH was added to the titania sol dispersion, the pH of the dispersion was adjusted to 5.0, and washing was repeated until the electrical conductivity of the supernatant reached 70 μS / cm.

A 0.95-fold molar amount of Sr (OH) ₂ .8H ₂ O was added to the hydrous titanium oxide, placed in a SUS reaction vessel, and purged with nitrogen gas. Further, distilled water was added so as to be 0.7 mol / liter in terms of SrTiO ₃ . The slurry was heated to 65 ° C. at 8 ° C./hour in a nitrogen atmosphere, and reacted for 5 hours after reaching 65 ° C. After the reaction, the reaction solution was cooled to room temperature, and the supernatant was removed. Then, the washing was repeated with pure water, and then filtered with Nutsche. The obtained cake was dried to obtain strontium titanate fine particles not passing through the sintering step.

  The strontium titanate fine particles were designated as inorganic fine particles E. Table 1 shows the physical properties of the inorganic fine particles E.

6) Production Example 6
Strontium titanate fine particles F were obtained by adjusting the pH, the molar amount of Sr (OH) ₂ .8H ₂ O added to the hydrous titanium oxide, the slurry temperature rise temperature and the reaction time. Table 1 shows the physical properties of the inorganic fine particles F.

7) Production Example 7
The hydrous titanium oxide slurry obtained by hydrolyzing the aqueous titanyl sulfate solution was washed with an alkaline aqueous solution. Next, hydrochloric acid was added to the hydrous titanium oxide slurry to adjust the pH to 1.5 to obtain a titania sol dispersion. NaOH was added to the titania sol dispersion, the pH of the dispersion was adjusted to 5.3, and washing was repeated until the electrical conductivity of the supernatant reached 100 μS / cm.

A 1.07-fold molar amount of Sr (OH) ₂ .8H ₂ O was added to the hydrous titanium oxide, and the mixture was placed in a SUS reaction vessel and purged with nitrogen gas. Further, distilled water was added so as to be 0.3 mol / liter in terms of SrTiO ₃ .

  The slurry was heated to 87 ° C. at 70 ° C./hour in a nitrogen atmosphere, and reacted for 5 hours after reaching 87 ° C. After the reaction, the mixture was cooled to room temperature, the supernatant was removed, and washing was repeated with pure water.

  Further, in a nitrogen atmosphere, the slurry is placed in an aqueous solution in which 1% by mass of sodium stearate is dissolved with respect to the solid content of the slurry, and while stirring, an aqueous zinc sulfate solution is dropped, and zinc stearate is deposited on the perovskite crystal surface. Was precipitated.

  The slurry was washed repeatedly with pure water and then filtered with Nutsche, and the resulting cake was dried to obtain strontium titanate fine particles whose surface was treated with zinc stearate.

  The strontium titanate fine particles having an average primary particle size of 320 nm were designated as G. Table 1 shows the physical properties of the inorganic fine particles G.

8) Production Example 8
The hydrous titanium oxide obtained by hydrolysis by adding ammonia water to the aqueous titanium tetrachloride solution was washed with pure water until the electrical conductivity of the supernatant reached 90 μS / cm.

A 1.5-fold molar amount of Sr (OH) ₂ .8H ₂ O was added to the hydrous titanium oxide, placed in a SUS reaction vessel, and purged with nitrogen gas. Further, distilled water was added so as to be 0.2 mol / liter in terms of SrTiO ₃ .

  The slurry was heated to 80 ° C. at 15 ° C./hour in a nitrogen atmosphere, and reacted for 5 hours after reaching 80 ° C. After the reaction, the mixture was cooled to room temperature, the supernatant was removed, and washing was repeated with pure water.

  Further, in a nitrogen atmosphere, the slurry is placed in an aqueous solution in which 18% by mass of sodium stearate is dissolved with respect to the solid content of the slurry. Was precipitated.

  The slurry was washed repeatedly with pure water and then filtered with Nutsche, and the resulting cake was dried to obtain strontium titanate fine particles whose surface was treated with zinc stearate.

  The primary particles were strontium titanate fine particles H having an average particle size of 350 nm. Table 1 shows the physical properties of the inorganic fine particles H.

9) Production Example 9
For Production Example 8, the electrical conductivity of the supernatant, the amount of Sr (OH) ₂ .8H ₂ O to be added, the temperature rise temperature, and the reaction time were adjusted, and strontium titanate having an average primary particle size of 420 nm. Fine powder I was obtained. Table 1 shows the physical properties of the inorganic fine particles I.

10) Production Example 10
For Production Example 8, the electrical conductivity of the supernatant, the amount of Sr (OH) ₂ .8H ₂ O to be added, the temperature rise temperature and the reaction time were adjusted, and strontium titanate having an average primary particle size of 500 nm. Fine particle J was designated. Table 1 shows the physical properties of the inorganic fine particles J.

11) Production Example 11
Strontium titanate fine particles K having an average primary particle size of 130 nm and an amorphous crystal shape were used. Table 1 shows the physical properties of the inorganic fine particles K.

12) Production Example 12
Strontium titanate fine particles L having an average primary particle size of 280 nm and an amorphous crystal shape were used. Table 1 shows the physical properties of the inorganic fine particles L.

13) Production Example 13
The inorganic fine powder E was sintered at 1000 ° C. and then crushed to obtain strontium titanate fine particles via a sintering process. The inorganic fine particles M were strontium titanate fine particles having an average primary particle size of 500 nm and an irregular particle shape. Table 1 shows the physical properties of the inorganic fine particles M.

14) Production Example 14
Strontium carbonate (SrCO ₃ ) equivalent to Ti is dissolved in 300 ml of titanium chloride 100 g / l (TiCl ₄ ) aqueous solution, and potassium hydroxide (KOH) equivalent to chlorine ion in the solution is added under a nitrogen atmosphere. The mixture was stirred and heated in a crepe at 140 ° C. for 3 hours. The product was filtered, washed and dried to obtain strontium titanate fine particles N. The fine particles N have an average primary particle size of 190 nm and have a spherical particle shape. Table 1 shows the physical properties of the inorganic fine particles N.

14) Comparative production example 1
The hydrous titanium oxide slurry obtained by hydrolyzing the aqueous titanyl sulfate solution was washed with an alkaline aqueous solution. Next, hydrochloric acid was added to the hydrous titanium oxide slurry to adjust the pH to 4.0 to obtain a titania sol dispersion. NaOH was added to the titania sol dispersion, the pH of the dispersion was adjusted to 8.0, and washing was repeated until the electrical conductivity of the supernatant reached 100 μS / cm.

  To the hydrous titanium oxide, 1.02 times the molar amount of Sr (OH) 2 .8H 2 O was added and placed in a SUS reaction vessel, and the nitrogen gas was replaced. Furthermore, distilled water was added so that it might become 0.3 mol / liter in conversion of SrTiO3. The slurry was heated to 90 ° C. at 30 ° C./hour in a nitrogen atmosphere, and reacted for 5 hours after reaching 90 ° C. After the reaction, the reaction solution was cooled to room temperature, and the supernatant was removed. Then, the washing was repeated with pure water, and then filtered with Nutsche. The obtained cake was dried to obtain strontium titanate fine particles having an average primary particle size of 25 nm.

  The strontium titanate fine particles were used as comparative fine powder A. Table 1 shows the physical properties of the comparative fine powder A.

15) Comparative production example 2
Strontium titanate fine particles having an average primary particle size of 620 nm were obtained. The strontium titanate fine particles were used as comparative fine particles B. Table 1 shows the physical properties of the comparative fine particles B.

16) Comparative production example 3
Strontium titanate fine particles having an average primary particle size of 24 nm and an amorphous crystal shape were obtained.

  The strontium titanate fine particles were used as comparative fine particles C. The physical properties of the comparative fine particles C are shown in Table 1.

17) Comparative production example 4
Strontium titanate fine particles having an average primary particle size of 530 nm and an amorphous crystal shape were obtained.

  The strontium titanate fine particles were used as comparative fine particles D. Table 1 shows the physical properties of the comparative fine particles D.

18) Comparative production example 5
600 g of strontium carbonate and 350 g of titanium oxide were wet mixed in a ball mill for 8 hours and then filtered and dried. The mixture was molded at a pressure of 10 kg / cm ² and sintered at 1200 ° C. for 7 hours. This was mechanically pulverized to obtain strontium titanate fine particles having an average primary particle diameter of 700 nm through a sintering process.

  The strontium titanate fine particles were used as comparative fine particles E. Table 1 shows the physical properties of the comparative fine particles E.

<< Example of photoconductor production >>
In the following production example, an a-Si photoreceptor was prepared.

  The surface of the support having an outer diameter of 80 mm (described as φ80) was cut using a commercially available cutting lathe. A support body in which the type of the R-shaped tool was shaken and a support body in which the installation angle and the penetration amount of the flat tool were controlled were prepared. In addition, a rotating ball mill was used to collide metal spheres having different particle diameters with the cylinders to create irregularly shaped supports.

The spectral sensitivity peak of the a-Si photosensitive member was approximately 660 to 700 nm, and the resistivity of the surface layer was 2 × 10 ¹⁶ Ω · cm.

  The film formation conditions of the photosensitive layer were fixed to the conditions shown in Table 2, and film formation was performed by RF-CVD to prepare positively charged a-Si photoconductors P01 to P05.

  Further, a photoconductor prepared by the same method as the photoconductor P01 was buffed to obtain photoconductors P06 to P07.

  Further, the photoconductors P08 to P12 were prepared by adjusting the film forming conditions, particularly the power of the photoconductive layer portion and the charge injection blocking layer portion, the substrate temperature, and the gas flow rate.

  The surface shapes of the prepared photoreceptors P01 to P12 were measured. The results are shown in Table 3.

  Although details are omitted in this example, the surface shape can also be controlled by changing the conditions of plasma CVD. For example, when the gas flow rate is increased and the discharge power / gas flow rate is increased, the 10-point average roughness Rz and the surface roughness Ra of the surface of the photoreceptor are increased.

  Table 4 shows the result of dividing the surface shape Rz of the photoreceptors P01 to P07 in Table 3 by the average primary particle diameter D of the inorganic fine particles A to N and the comparative fine particles A to E in Table 1.

<< Production Example of Coating Agent S >>
The coating agent S was created in the following production example.

  Commercially available zinc stearate (SZ-2000 manufactured by Sakai Chemical Industry) was prepared. A fine powder and a solid A3 long rectangular solid were prepared. The hardness of the solid molded product was HF in JIS pencil hardness.

<< Production Example of Coating Agent Application Unit 111 >>
As a means for applying the coating agent S to the surface of the photoreceptor 101, there is a method in which the coating agent S is externally added to the developer and supplied from the developing means. However, in this case, the developing sleeve may be contaminated with the coating agent, which may cause problems such as a decrease in the developing density. Therefore, the coating agent applying member 111 is separately provided as described below.

A. Direct Application Member The solid molded product of the coating S was directly brought into contact with the surface of the photoreceptor 101 using a spring 111-1 as shown in FIG.

B. Fur brush 11-2 rayon conductive yarn was used, 100 kF / inch ² and a hair length of 4 mm, and a fur brush 111-2 having an outer diameter of 18 mm was prepared.
In addition, F / inch ² is a unit (F; filament... Number of fibers) representing the density of fibers to be used, and in this example, indicates that the density is 100k in 1 inch square.

C. Elastic roller An elastic roller 111-3 made of an elastic foam and having an Asker C hardness of 25 degrees and an outer diameter of 18 mm was prepared.

D. Magnetic brush A 6-pole magnet roller having an outer diameter of 15 mm was prepared, and a magnetic carrier having an average particle diameter of approximately 20 μm, which was known as a magnetic particle, was prepared. When the image forming apparatus to be used uses a magnetic developer, the magnetic developer was used as magnetic particles in order to simplify the mechanism. Further, a magnetic carrier layer thickness regulating member was provided to produce a magnetic brush 111-4 having an outer diameter of 20 mm.

  The above-mentioned coating members B to D were provided with means for driving the photoconductor in the counter direction at the contact portion with the photoconductor, and grounded to prevent leakage and the like.

  Further, as shown in FIG. 18, the coating agent S molded in a rectangular parallelepiped shape is placed on the fixing member so as to come into contact with the application members B to D with a predetermined contact pressure.

<< Manufacturing Example of Developer >>
In the following production example, a developer composed of toner particles and various additives was prepared.

Well-known polyester binder resin: 100 parts by mass Magnetic iron oxide: 100 parts by mass Monoazo iron compound: 2 parts by mass Salicylic acid Al compound: 1 part by mass Fischer-Tropsch wax ...・ 4 parts by mass (DSC peak top temperature = 104 ° C., Mw / Mn = 1.8)
Is premixed with a Henschel mixer. This was melt kneaded with a biaxial extruder heated to 130 ° C., and the cooled kneaded product was coarsely pulverized with a hammer mill to obtain a coarsely pulverized toner product.

  The obtained coarsely pulverized product is adjusted to -15 ° C at the inlet air temperature, 48 ° C at the outlet air temperature, and -5 ° C to cool the cooling rotor and liner, using a mechanical pulverizer turbo mill. And finely pulverized by mechanical pulverization.

  The resulting finely pulverized product was subjected to strict classification and removal of fine powder and coarse powder at the same time using a multi-division classifier (Elbow Jet Classifier manufactured by Nittetsu Mining Co., Ltd.) using the Coanda effect.

  Thereafter, toner particles having various degrees of circularity were prepared using a mechanical surface reformer.

100 parts by mass of the toner particles and 1.5 parts by mass of hydrophobized silica particles obtained by subjecting BET 200 m ² / g dry silica to a hydrophobization treatment are mixed with a Henschel mixer.

  As a result, negatively chargeable toners T1 to T11 having a weight average particle diameter X of 6.4 μm and an average circularity a as shown in Table 5 were obtained.

<< Production example of rubbing / recovering member 110 >>
In the following production examples, various rubbing / recovering means 110 were created.

1) Production Example 1
A urethane blade material 110-1 having a thickness of 2 mm made of the same material as the cleaning blade used in the Canon Co., Ltd. iR6570 copier was prepared.

  The member was set to have a free length of 5 mm, a contact angle of 140 ° (40 ° in the forward direction), and a contact pressure of a total pressure of 800 g.

2) Production Example 2
A brush roller 110-2 was prepared in which 2tex (18D) rayon in which carbon was dispersed was provided at 9.3 × 10 ³ F / cm ² (60 kF / inch ² ). The brush roller 110-2 was disposed so as to enter the photosensitive member by 1.5 mm. Further, a scraper was installed in the cleaning container 105a so as to enter the brush roller by 0.5 mm.

3) Production Example 3
By a known method, an elastic roller 110-3 made of urethane foam in which carbon is dispersed on a φ8 core metal was prepared. The elastic roller has a large number of single bubble cells having an average pore diameter of φ50 μm. Asker-C hardness was 25 degrees, and it was installed so as to penetrate 0.5 mm into the photoreceptor. Further, a scraper was installed in the cleaning container 105a so as to enter 0.2 mm into the elastic roller.

4) Production Example 4
A magnet roller made of a plastic magnet was formed on a core metal of φ8 by a known method. A magnetic brush 110-4 was prepared by providing a thickness regulating member (not shown) and a scraper so that the magnetic particles were coated with a thickness of 1.5 mm on the magnet roller. The magnetic brush was placed in contact with the surface of the photoreceptor with an intrusion amount of 0.2 mm.

  The fur brush roller 110-2, the elastic roller 110-3, and the magnetic brush 110-4 have driving means that is driven to rotate at an arbitrary speed with respect to the surface speed of the photosensitive member in synchronization with the rotation of the photosensitive member.

  Each of the rubbing / polishing members 110-1 to 110-4 was grounded to prevent charge-up. If necessary, a bias applying means may be added instead of grounding as in the embodiments described later.

[Example 1]
As an evaluation apparatus, a Canon Co., Ltd. copier iR6570 (scorotron charger, photoreceptor surface speed 290 mm / sec, 65 ppm machine) was modified to obtain an evaluation machine as shown in FIG.

  Specifically, the charging conditions and exposure conditions can be controlled externally, and the photoreceptor surface speed can be adjusted. Of course, the conditions of each unit such as paper conveyance are also adjusted in synchronization with the surface speed. In this embodiment, the photoreceptor surface speed is left at the iR6750 default.

  In printing durability and each evaluation, the charging conditions and the exposure conditions were adjusted so that the dark potential at the developing position of the photoconductor was 420 V, and the latent image exposure potential was 50 V.

  Further, the drum heater, the cleaning blade, and the cleaning auxiliary members (magnet roller, doctor roller, etc.) provided as standard are removed, and the rubbing / recovering means 110 and the coating material applying means 111 are provided. It was remodeled as follows.

  As the rubbing / recovering member 110, a fur brush 110-2 was used, and the amount of penetration into the photosensitive member was 0.5 mm, and the driving speed was −80% (counter direction 80%). Further, the inorganic fine particles M can be supplied from the cleaning container 105a.

  The waste toner portion that collects transfer residual toner, paper powder, excess inorganic fine particles, and the like was separated by a partition member (not shown). After passing through the waste toner portion, the rubbing / collecting unit 110-2 cleaned by a scraper (not shown) supplies the inorganic fine particles from the inorganic fine particle portion to the surface of the photoreceptor 101.

  A to M were used as the inorganic fine particles, and T10 (Table 6: Average circularity a = 0.918) was used as the developer.

  As the coating agent S, the aforementioned zinc stearate fine powder was put in a container. The coating agent supply means 111 uses a fur brush 111-2, and has an intrusion amount of 0.5 mm and a driving speed of + 75% (forward direction 75%). The coating amount of the coating was obtained from the difference between the total weight of the coating S, the coating member, and the container of the coating S before and after the printing durability evaluation. The same can be obtained for molded products.

As the evaluation photoreceptor, the above-described photoreceptor P01 was used.
Using this evaluation device, ruled lines (500 μm lines at equal intervals in the sheet passing direction were arranged at 10 mm intervals in the paper passing direction as shown in FIG. 19 in an environment of 30 ° C./80% humidity (H / H). %) Was continuously printed at 20 k sheets / day. Thereafter, various image formations for evaluation were performed, and the main switch was turned off and left at night. The next morning, after the evaluation image was formed, the 20 k sheet / day printing durability test was continued in the same manner, and the printing durability test up to 300 k was performed. Next, in a (L / L) environment at a temperature of 10 ° C./humidity of 15%, similarly, 100 k sheets, a total of 400 k sheets, was passed. Each 100k was left for 5 nights, and the characteristics after long-term storage were evaluated.

  As an evaluation image, a grid image obtained by intersecting 300 μm lines at intervals of 5 mm, a halftone image of 1 dot 1 space, 1 dot 2 space, solid black, and a 17 gradation image were formed.

In Example 1, the coating material application amount T was 0.88 [μg / cm ² ].

  The photoconductor durability was evaluated by the amount of abrasion on the surface of the photoconductor and scratches. The amount of wear was measured with a reflection spectroscopic interferometer (trade name: MCPD-2000, manufactured by Otsuka Electronics Co., Ltd.), and was calculated as wear rate [nm / rotation] per rotation. Further, the surface roughness of the surface of the photoreceptor was measured as an additional measurement point at any 12 points on the surface of the photoreceptor and where a scratch or streak was visually recognized.

  The evaluation criteria are as follows.

1) Image flow (H / H environment)
Judgment was made from the sample image of the morning after printing. The judgment criteria are as follows.

A: Very good (no blurring of lines and dots in the above evaluation image)
○: Good (Lattice image cannot be recognized, dot blurring or density drop in some areas of halftone or gradation image, but recovered within 10 sheets of A4 paper)
●: Practical (Lattice image cannot be recognized, halftone or gradation image has dot blur or density reduction, 10-30 images until recovery)
△: Practical (The grid image cannot recognize the flow, the halftone or gradation image has dot blurring or density reduction, it exceeds 30 sheets until recovery, or the grid image can recognize some flow, but the grid image (Up to 10 sheets until flow recovery)
×: Other than the above (flow is recognized by grid images)
2) CLN (cleaning) durability The cleaning property was evaluated for filming, toner fusion, abrasion, and abnormal noise (vibration sound, resonance sound). Especially when using blade cleaning, the edge portion of the cleaning blade was observed with a microscope before and after the endurance to evaluate the wear level.

  After the printing durability test, the surface of the rubbing / removal member, or the cutting surface and contact surface of the cleaning blade are observed with a microscope, and the size and number of chipping, scratching, and member wear areas, toner slipping, chattering, and twisting The cleaning failure was evaluated.

  The judgment criteria are as follows.

◎; Very good (no chipping, chipping or fur wear area. No more than three chipping, chipping or fur wearing areas below the toner particle size. )
◯: Good (4-5 spots of chipping, erosion or fur wear below the toner particle size, no toner particle size or more, no scraping, no turning, resonance noise may occur when the photoreceptor is stopped. Or chatter may occur (frequently)
●: Practical use (Sheets smaller than the toner particle size, chipping, or wear area of the fur is 6 to 10 and there are toner particles larger than the particle size, but there are no more than twice the toner particle size, no rubbing through , Resonance sound or chatter may occur (frequently))
△: Practical (no chipping below the toner particle size, gap or fur wear area is 10 or more, and there are more than twice the toner particle size, but there is no scraping, both resonance and chatter occur May be (frequently))
×: Other than the above (there is scraping due to chipping, erosion, or a worn area of the fur, or in the case of a blade, peeling may occur, chattering and resonance sound occur or the frequency is high)
3) Photoconductor durability As an evaluation of photoconductor wear, after the printing durability test, the body printing test was continued in an H / H environment to obtain a printing durability test of a total of 1,200k sheets. The coating agent S, the coating member 111, the inorganic fine powder, the rubbing / recovering member 110, and the like are subjected to maintenance such as replenishment and replacement every 400k as necessary.

  The film thickness wear of each photoconductor before and after the printing durability test was measured. In the measurement of the thickness of the photoreceptor, the surface layer thickness of the photoreceptor was measured at a total of 36 locations, 6 locations in the circumferential direction and 6 locations in the major axis direction, and the average value was taken as the average surface layer thickness. The amount of wear was calculated as wear rate [nm / 10k rotation (rot)] per 10,000 rotations by dividing by the difference in average surface layer thickness before and after endurance and the number of rotations of the photoreceptor. The image density was measured as an absolute density, and the above image at the time of each image evaluation was measured using a densitometer “RD-918” (manufactured by Macbeth).

  The judgment criteria are as follows.

A: Very good (wear rate is 1.5 [nm / 10 krot] or less and no uneven wear)
○: Good (wear rate is 1.5 [nm / 10 krot] or less, there is uneven wear, but there is no measurement point exceeding 2.0 [nm / 10 krot], and the difference in image density between the uneven wear portion and its vicinity is 0 .2 or less)
X: Other than the above (there is a measurement point where the wear rate exceeds 1.5 [nm / 10 krot] or exceeds 2.0 [nm / 10 krot], or the difference in image density between the uneven wear portion and its vicinity exceeds 0.2)
The evaluation results are shown in Tables 6-8.

[Examples 2 to 7]
Evaluation was performed in the same manner as in Example 1 except that the photoconductors P02 to P07 were used as the photoconductor for evaluation. The coating amount of the coating agent is the same as in Example 1. The results are shown in Tables 6-8.

  In particular, the flow and CLN durability results are shown in FIG. 20 as a correlation with the average primary particle size D of the inorganic fine particles. From Table 6 to Table 8 and FIG. 20, good results were obtained when the average particle diameter D of the inorganic fine particles was 30 to 500 nm. Even better results were obtained when the average particle size D of the inorganic fine particles was 100 to 300 nm. In addition, it can be seen from the comparison between the inorganic fine particles A to M, particularly E and N, that the circularity of the inorganic fine particles is preferably 0.930 or less.

  FIG. 21 shows the correlation between the evaluation result of the flow and the inorganic fine particles having an average particle diameter D of 30 to 500 nm and the ratio (Rz / D) to Rz of the photoreceptors P01 to P07. Show. From FIG. 21, it can be seen that even better results are obtained when Rz / D is 0.5 to 2.0.

  In addition, the coating material application member 111 uses an elastic roller 111-3 so that the penetration amount into the photosensitive member is 0.3 mm. In the system in which the rubbing / recovering member 110 is driven by the elastic roller 110-3 under the same driving condition as that of the fur brush, the same result as that obtained when the fur brush was used was obtained.

  In a low speed machine of less than 100 mm / sec (approximately 20 ppm), the life level required in the market is several k to several tens of k. A long-life photoconductor such as an a-Si photoconductor, and the combined use of the coating means and the rubbing means can provide good results in terms of technology, but the cost increases, so from the viewpoint of cost effectiveness, Not necessarily practical.

[Comparative Examples 1-7]
Evaluation similar to the example of the fur brush of Example 1 was performed except that the comparative fine particles A to E were used as the inorganic fine particles. The coating amount T is the same as that in Example 1.

  Tables 6 to 8 show the printing durability evaluation results of Comparative Examples 1 to 5. In particular, the flow and CLN durability were different from those of the examples.

Example 8
The same coating material S and rubbing / recovery member 110 as those in Example 1 were used. The coating material application member uses the elastic member 111-3 in the same manner as in Example 1, and the coating material application means 111-3 varies the amount of penetration into the photosensitive member and the driving speed, and the coating amount S of the coating material S is determined. The same evaluation as in Example 1 was performed.

  Similarly, the rubbing / polishing member 110 is also an elastic member 110-3, and in accordance with the increase / decrease in the coating amount T, the intrusion amount and driving conditions are adjusted as necessary to match the rubbing / collecting ability. did.

Using the photoreceptor P01 and the inorganic fine particles D, the same printing durability test as in Example 1 was performed, and the dependency on the coating amount T [μg / cm ² ] was evaluated.

  Similarly, for the photoreceptors P08, P09, P10, P11, and P12, D, E, E, F, and F were used as inorganic fine particles, respectively, and the same printing durability test and evaluation were performed. The inorganic fine particles for each photoconductor were selected so that Rz / D was approximately 1.0 and the conditions were not greatly different.

  The evaluation results are shown in Tables 9 to 11.

  From Table 11, regarding the photoreceptor durability, very good results were obtained in most evaluations of this example. It is considered that the use of a metal soap material as the coating agent S and the action of the inorganic fine particles were synergistic.

  Table 10 shows that the coating agent S may be a metal soap in synergy with the action of the inorganic fine particles, and good results were obtained with a small amount of coating and cleaning durability.

  From Table 9, the flow is not always very good even if the cleaning performance and cleaning durability are in a very good range, and the lower limit of the coating amount T of the coating agent S is required to be larger than that for cleaning. It turns out that it is.

  This will be discussed next. In other words, in order to function as a lubricant, it is only necessary to exist at a certain degree or more in the contact portion between the photosensitive member and the coating means 111, the rubbing means 110, etc. that are in contact therewith. On the other hand, in order to suppress the flow, it is considered that a larger amount than the lubricant is required to spread and coat the entire surface of the photoreceptor.

  From Tables 9 to 11, it can be seen that the range of the preferred coating amount T of the coating agent S varies depending on the Ra of the photoreceptor.

  FIG. 22 shows the correlation between Ra and the area “◎” in Table 9 (flow) and Table 10 (cleaning durability).

The lower limit of the required coating amount of the coating agent is rate-determined by the flow, and the coating amount T [μg / cm ² ] of the coating agent per unit area (when the photosensitive member advances 1 cm per 1 cm in the longitudinal direction of the coating agent) When satisfying Equation 3, good results were obtained.

T ≧ 0.61 × Ra + 0.064 Formula 3
In addition, when the coating amount T is excessive, uneven coating such as uneven coating or uneven coating may occur, and rubbing / polishing may not be uniform, and the effect on the flow may be reduced locally. there were.

  Regarding the CLN durability, if Ra is too small, the driving torque of the rubbing / recovering means 110 and the applying means 111 may increase or the wear of these members may occur. On the other hand, when Ra is too large, uneven rubbing occurs, and the effect on the flow and cleaning properties may be locally reduced. Ra is preferably within the range of Formula 4.

0.010 μm ≦ Ra ≦ 0.100 μm Formula 4
Further, when the application amount T is excessive application, the drive torque of the rubbing / recovery means 110 and the application means 111 may increase and the wear of these members may occur. From Tables 10 to 12 and FIG. 22, the coating amount T is preferably in the range of Formula 5.

T ≦ 1.500 μg / cm ² Formula 5
In the region indicated by the wavy line in FIG. 22, the flow, cleaning durability, and photoreceptor durability characteristics were very good.

[Comparative Example 8]
Evaluation was performed in the same manner as in Example 1 except that the coating material S and the coating material application unit 111 were omitted. The results are shown in Table 12.

  From Table 12, the cleaning durability and the photoreceptor durability were almost the same as in Example 1. On the other hand, regarding the flow, the level was lower than that in Example 1 in which the coating agent was applied particularly by the charger trace flow of the corona charger.

  Moreover, the same evaluation as Example 1 was performed similarly to the above except that the zinc stearate fine powder was removed and the coating agent was not used. The contact condition and driving condition of the coating material application unit 111 were the same as those in Example 1. Even in this system, the same results as in Table 12 were obtained, but in some cases, the wear of the fur of the coating material applying means 111 sometimes occurred.

Example 9
For Example 1, a solid molded product was used as a coating agent, and direct coating, fur brush coating, and elastic roller coating were evaluated.

  As a direct coating method, the molded coating S is directly brought into contact with the surface of the photoconductor with a predetermined contact pressure by means of direct application 111-1 (FIG. 18). Instead, the coating S in a fine powder state is used. The coating container was removed.

  In order to prevent uneven coating due to the surface shape or the like of the photoconductor, reciprocating drive is performed in the bus line direction of the photoconductor by the driving means. The application amount T can be controlled by adjusting the contact pressure and reciprocating conditions. What is necessary is just to adjust in the range which does not produce wear to this coating material S or a photoreceptor.

  The fur brush system and the elastic roller system are configured as shown in FIG.

  As a fur brush application method, a solid molded product of a coating material was brought into contact with a coating material application member 111-2 made of a fur brush with a predetermined contact pressure using a pressing means. Again, the powder container was removed. Control of the coating amount T of the coating material is performed by changing the hardness of the molded coating material S and / or the condition for contacting the coating material S with the coating material application member 111 and / or the driving condition of the coating means 111-2. Adjust it. In addition, the mechanism which makes the coating material S reciprocate was not provided.

  As an elastic roller application method, an applicator 111-3 made of an elastic roller was used, and an evaluation machine was prepared according to the fur brush type application means 111-2.

In any of the above methods, the coating amount T was set to 0.88 [μg / cm ² ] as in Example 1. When the same evaluation as in Example 1 was performed, the same results as in Example 1 were obtained. In addition, the apparatus configuration can be simplified by using the molded coating agent S, and maintenance is facilitated.

Example 10
In contrast to Example 9, the coating material application member 111 was a magnetic brush 111-4 coated with magnetic particles having an average particle diameter of 15 μm. The coating amount T is controlled by adjusting the conditions for bringing the solid molding of the coating S into contact with the magnetic brush 111-4 as the coating means and the driving conditions for the magnetic brush 111-4. it can. The driving condition of the magnetic brush 111-4 was + 75% (75% in the forward direction).

  In this state, when the same evaluation as in Example 9 was performed, the same result was obtained. Further, in this example using the magnetic brush coating material application means 111-4, the coating material S and the coating material application means 111 do not require maintenance in the printing durability of 1200k sheets, or are molded coating material S. The maintenance and maintainability have been greatly improved.

Example 11
To developer T10 (Table 6), inorganic fine particles A to M and comparative fine particles A to E are further added in an amount of 1.5 parts by mass with respect to 100 parts by mass of toner particles by a well-known method. 'I got.

  The T10 'was used as a developer, and inorganic fine particles were supplied from the developing means. Of course, the development conditions and transfer conditions are adjusted according to changes in the developer.

  As the rubbing / recovering member 110, a magnetic brush 110-4 coated with magnetic particles having an average particle diameter of 15 μm was used. In the magnetic brush 110-4, excess magnetic particles are scraped off by a layer thickness regulating member and a scraper, and a constant outer diameter is maintained. Instead, as shown in FIG. 3, the mechanism for storing inorganic fine particles was removed.

  Except for the above, the same evaluation as in Example 10 was performed in the same manner as in Example 10. The results are shown in Table 14.

  As for the flow, the same results as in Example 1 were obtained. Since the inorganic fine particles are supplied from the developing means, the action of the inorganic fine particles is not particularly localized depending on the image ratio to be formed.

  The fluidity of the magnetic brush suppresses the localization of the inorganic fine particles due to the image ratio and image localization, and it is considered that the rubbing is performed uniformly. Further, with respect to the rubbing / recovering member of the magnetic brush, no maintenance is required for 1200 k printing durability.

  Further, similar results were obtained even when T10 ', which is a magnetic developer, was used as the magnetic particles constituting the magnetic brush.

Example 12
In contrast to Example 11, as a magnetic particle coated on the magnetic brush 111-4 as a coating agent applying means and the magnetic brush 110-4 as a rubbing / recovering means, a developer T10 ′ to which inorganic fine particles are externally added. It was used. Further, the magnetic brush type coating material applying means 111-4 is driven at -70% (counter 70%) with respect to the photosensitive member. The position of the coating material S, the doctor roller, and the scraper was adjusted with the change in the driving direction. The coating amount T of the coating agent S was the same as in Example 11.

  Other conditions were the same as in Example 11, and the same evaluation as in Example 11 was performed. The results are shown in Table 13.

  From Table 13, a better result was obtained in Example 12, particularly with respect to the flow. Moreover, the coating material S and the maintenance property were also favorable.

  Using a magnetic brush, in addition to the suppression of coating application, rubbing / recovery localization, the application means was counter-driven to scrape off inorganic fine particles leaking from the rubbing / recovery means 110. After that, a coating agent is spread on the surface of the photoreceptor.

  FIG. 23 shows a model diagram in the vicinity of the contact portion between the photosensitive member 101 and the coating unit 111. The photosensitive member 101 and the coating unit 111 move in the directions of arrows.

  Excess inorganic fine particles leaked from the rubbing / collecting means 110 (not shown) on the upstream side (lower side in FIG. 23) of the contact portion in the traveling direction of the photosensitive member 101 rotate the coating means 111. Thus, the intrusion to the corresponding contact portion is suppressed.

  On the other hand, the coating agent S is applied to the surface of the photoreceptor 101 from which excess inorganic fine particles have been removed on the downstream side (upper side in the drawing) from the corresponding contact portion.

  Thereafter, the coating material S conveyed to the vicinity of the contact portion by the application unit 111 is uniformly applied and spread by the rubbing of the surface of the photoreceptor 101 and the application unit 111.

  Further, the coating material S stays in the vicinity of the contact portion due to the movement of the photosensitive member 101. Even during the stay, the coating material S is leveled in the longitudinal direction by the movement of the photosensitive member 101 and the coating unit 111.

  This is considered to be a result of synergy that a more uniform film is formed. Alternatively, it is considered that a stay region of the coating agent S is likely to be generated in the immediate vicinity of the contact nip between the photosensitive member 101 and the coating unit 111 and promotes the formation of the coating film.

Example 13
Further, as shown in FIG. 5, cleaning means (blade cleaning) 106 of a copying machine iR6570 manufactured by Canon Inc. was added to Example 11. The installation conditions of the cleaning blade 106 were the same as those of the copying machine iR6570.

  As magnetic particles coated on the magnetic brush 111-4 as the coating agent applying means and the magnetic brush 110-4 as the rubbing / recovering means, developer T10 'to which each inorganic fine particle was externally added was used. Other conditions were the same as in Example 11, and the same evaluation as in Example 11 was performed.

  The results are shown in Table 13. From Table 13, the results of Example 13 were better than those of Example 11 in particular regarding the flow. Further, the cleaning blade 106 (CLN blade) was hardly worn and the maintainability was good.

  In addition to the fact that the application of the coating material, the rubbing / recovery was prevented from being localized using the magnetic brush, the coating material was spread by the cleaning blade 106, and a more uniform film was formed. The result is considered.

Example 14
As magnetic particles coated on the magnetic brush 111-4 as the coating agent applying means and the magnetic brush 110-4 as the rubbing / recovering means, developer T10 ′ to which each inorganic fine particle was externally added was used.

  Further, in Example 13, the magnetic brush type coating material applying means 111-4 was driven at -80% (counter 80%) with respect to the photoreceptor. The coating amount T of the coating agent S is the same as in Example 11. In this embodiment, the coating material application means 111-4 also has a rubbing / recovery function, and the application means 111-4 is provided with a doctor roller and a scraper. The configuration shown in FIG.

  The results of the same evaluation as in Example 13 are shown in Table 11. From Table 11, good results were obtained as in Example 13.

Example 15
Among the developers T10 ′, those obtained by externally adding inorganic fine particles J and M having an average primary particle diameter D of 500 nm were used. Further, P01 was used as the photosensitive member, the photosensitive member surface speed was set to 80 ppm at 320 mm / sec, and 500 μm lines were arranged at intervals of 20 mm as images formed in the printing durability test. The image ratio was 2.5%. The speed of each means such as paper feeding and paper discharging means, the bias condition applied to the charging means, the exposure means, etc. were adjusted in association with the photoreceptor surface speed.

  Under these conditions, the printing durability test and the evaluation were performed in the same manner as in Example 11. The results are shown in Table 14. From Table 14, it can be seen that the rectangular inorganic fine particles J have a wider latitude for flow and CLN durability than the amorphous inorganic fine particles M.

Example 16
P01 was used as the photoreceptor. Further, as the developer, a product obtained by externally adding inorganic fine particles G having an average primary particle diameter D of 320 nm to T1 to T11 as in Example 11 was used.

  Using these photoreceptors, inorganic fine particles, and developers, printing durability and evaluation were performed in the same manner as in Example 11. The results are shown in Table 15.

  From Table 15, good results were obtained when the average toner circularity a was 0.930 to 0.970, particularly 0.935 or more. By controlling the circularity of the toner, uniformity in the vicinity of the contact portion of the rubbing / collecting means is improved, cleaning durability is improved, and uniform rubbing / collecting is performed. It is considered that the effects of the above are synergistic and the flow level is improved.

Example 17
In contrast to the fourteenth embodiment, as shown in FIG. 8, the charging means 102 is a charging roller for a copying machine iR400 manufactured by Canon Inc. The holding means of the charging means 102, the contact condition to the photosensitive member, and the cleaning for the charging means. The members also have the iR400 specifications.

  In addition, the transfer / separation means 108 also uses the iR400. The pre-transfer charging means (not shown) attached to the iR6570 as a standard was removed, and there was no so-called corona charging.

  The charging means 102 and the charging means cleaning means were replaced with new ones every 40k sheets, and printing durability evaluation was performed in the same manner as in Example 14. The results are shown in Table 16. From Table 16, a better result than Example 14 was obtained especially in the flow.

Example 18
As shown in FIG. 13, a resin thin film layer was provided on the surface of the conductive resin roller for resistance adjustment, and a charging means 102 having the same resistance as that of the iR400 charging roller was produced. This charging means 102 was provided as a proximity distance regulating means with a roller outside the image area, and maintained at 30 μm at the closest distance to the photoreceptor. Except that the charging unit 102 is driven to rotate in synchronization with the photosensitive member 101, the holding of the charging unit 102 and the cleaning member for the charging unit are also the specifications of the iR400.

  Table 16 shows the results of the same printing durability evaluation as in Example 14 except for the above. From Table 16, as in Example 17, particularly better results than Example 14 were obtained in the flow. Further, the charging means was less contaminated than in Example 17, and the durability of the charging means and the charging means cleaning means was improved.

  Generally, in the corona charging means, the charged product adheres to the housing part during image formation, and the charged product is deposited from the housing part on the surface of the photoconductor during standing for a long period of time, and the flow tends to occur at the charging unit facing part. Become. The reason why the flow is improved in Examples 17 and 18 is considered to be that the above-mentioned yielding is suppressed by removing the corona charging means.

Example 19
An a-Si photoconductor of φ30 having the same surface properties as the photoconductor P01 was prepared.

  As an evaluation apparatus, a Canon copier iR400 was modified to obtain an evaluation machine as shown in FIG. Specifically, an LED having a peak wavelength of 680 nm was used as the charge eliminating means 107, and was disposed between the transfer process and the cleaning process as shown in FIG.

  The surface speed of the photoconductor is set to 50 ppm (ppm; Print Per minute) at 240 mm / sec, and the polarity and bias can be adjusted by modifying the high-voltage power supply for regular development of the positively charged a-Si photoconductor and the negatively charged developer. I made it.

  At this time, the time from the cleaning process to the charging process is 90 msec, and the time from the charge removal process to the charging process is 130 msec.

  Further, the latent image exposure means was modified, a laser having a center wavelength of 660 nm was used, and a BAE of 256 dpi with a spot diameter of 40 μm was set to PWM of 256 gradations.

  Further, waste toner conveying means is provided so that transfer residual toner, paper dust and the like collected by the cleaning means are collected in a waste toner box (not shown). Furthermore, modifications such as adjustment of exposure amount and charging conditions and installation of an electrometer were made so that potential evaluation could be performed. The electrometer used was 344 made by TRek 杜 and probe 555P-1 made by the same company, and was installed at the developing means position with a dedicated jig to measure the potential.

  Further, the waste toner feeding blade of the iR400 cartridge was removed, and the molded coating material S, magnetic brush type coating material coating means 111-4, a doctor roller, and a scraper (not shown) were installed.

The development position potential of the photosensitive member was set to the same potential as in Examples 1 to 18, and printing durability and evaluation similar to those in Example 17 were performed. As a result, very good results were obtained as in Example 17.
Furthermore, as a result of performing the same evaluation by changing the photosensitive member surface speed and the position of the charge removal means 107, the charge potential and the image quality were stable when the time from the charge removal process to the charge process was 100 msec or more.
On the other hand, when the charging process is 100 msec or less from the cleaning process, in a system in which the charge removal process is provided between the cleaning process and the charging process, the charge potential may become unstable and the image quality may deteriorate. Conversely, if the current amount of the charging unit is increased in order to stabilize the image quality, the cleaning unit may be worn out or the rubbing or covering may be insufficient.

  Similarly, good results were also obtained in the case of the configuration as shown in FIGS. In particular, the rotatable configuration shown in FIG. 13 is more durable than the configuration shown in FIG.

Schematic configuration diagram of an image forming apparatus according to an embodiment (part 1) Schematic configuration diagram of image forming apparatus of embodiment example (2) Schematic configuration diagram of an image forming apparatus of an embodiment (part 3) Schematic configuration diagram of image forming apparatus of embodiment example (No. 4) Schematic configuration diagram of image forming apparatus of embodiment example (No. 5) Schematic configuration diagram of image forming apparatus of embodiment example (No. 6) Schematic configuration diagram of an image forming apparatus of an embodiment (part 7) Schematic configuration diagram of an image forming apparatus of an embodiment (No. 8) Schematic configuration diagram of image forming apparatus of embodiment example (9) Schematic configuration diagram of image forming apparatus of embodiment example (No. 10) Schematic configuration diagram of an image forming apparatus of an embodiment (No. 11) (A) and (b) are schematic views showing another embodiment of the proximity charging unit in FIG. 11, respectively. Schematic configuration diagram of an image forming apparatus of Embodiment (No. 12) Electron micrograph (SEM photo) of an example of inorganic fine particles The figure which shows an example of the layer structure of an a-Si photoreceptor (A), (b) and (c) are schematic views showing the relationship between the support surface shape of the photoreceptor and the surface shape of the photoreceptor, respectively. IAE and BAE photoreceptor surface potential model Schematic showing an example of coating agent application means (direct application) Schematic diagram of printing durability test chart used in Examples and Comparative Examples The graph which shows the correlation of the average particle diameter of inorganic fine particles and evaluation result in Examples 1-7 The graph which shows the correlation of ratio Rz / D of Rz on the surface of a photoreceptor, and the average particle diameter D of inorganic fine particles, and an evaluation result in Examples 1-7 The graph which shows the suitable range of Ra on the surface of a photoreceptor, and coating agent coating amount T in Example 8 Model diagram for explaining the behavior of the inorganic fine particles and the coating material S when the coating material application means is counter-driven in Example 12 Schematic configuration diagram of an image forming apparatus according to an exemplary embodiment

Explanation of symbols

  101, 1500; photoconductor, 102; charging means, 103; latent image forming exposure means, 104; developing means, 105; post-processing means, 105a; cleaning container, 106; cleaning means, 107; 109; Conveying means 110; Rubbing / collecting means 111; Coating agent applying means 1501; Support 1502; Photosensitive layer 1503; Photoconductive layer 1504; Surface layer 1505 · 1506; , X: photosensitive member traveling direction, P: transfer material, S: coating agent, Vdi · Vdb; development bias DC potential, ΔVl1 · ΔVl1; development contrast

Claims (20)

A rotating image carrier, a charging step for charging the image carrier, a latent image forming step for forming a latent image on the charged image carrier, and developing the latent image as a developer image with a developer. In an image forming method comprising: a developing step to transfer; and a transfer step to transfer the developer image to a recording medium.
A rubbing step of rubbing the surface of the image carrier through abrasive particles made of inorganic fine particles having an average particle diameter D of 30 to 500 nm between the transfer step and the charging step; and the surface of the image carrier An image forming method comprising: a coating step of applying and spreading a coating agent.   2. The image forming method according to claim 1, wherein the inorganic fine particles have an average particle diameter D of 100 to 300 nm.   The image forming method according to claim 1, wherein the coating agent is a fatty acid metal salt.   4. The image forming method according to claim 1, wherein the inorganic fine particle is a perovskite crystal.   The image carrier is an electrophotographic photosensitive member, and the surface layer is made of a non-single crystal material containing a silicon atom and a carbon atom or a silicon atom or a carbon atom as a base and a hydrogen atom and a halogen atom or a hydrogen atom or a halogen atom. The image forming method according to claim 1, wherein:   The image according to any one of claims 1 to 5, wherein the 10-point average roughness Rz of the surface of the image carrier is 0.5 to 2 times the average particle diameter D of the inorganic fine particles. Forming method. The surface roughness Ra of the surface of the image carrier is 0.01 μm or more and 0.100 μm or less, the surface roughness Ra [μm], and the coating agent contact area with the surface of the image carrier in the coating step The image forming method according to claim 1, wherein the coating amount T [μg / cm ² ] of the coating agent per unit area [cm ² ] in the above satisfies the following formula.
T ≧ 0.61 × Ra + 0.064 The image forming method according to claim 7, wherein the coating amount T [μg / cm ² ] is 1.5 or less.   The image forming method according to claim 1, wherein the coating agent before being coated on the surface of the image carrier is a solid formed into a predetermined shape.   The image forming method according to claim 1, wherein the covering step is performed by a magnetic brush.   11. The image forming method according to claim 1, wherein the developer used in the developing step is a magnetic developer comprising at least magnetic toner particles and an external additive.   The magnetic toner particles have a weight average particle diameter X (μm) of 4 μm to 12 μm, and an average value of average circularity a ′ measured by an equivalent circle diameter of 3 μm or more and 400 μm or less measured by a flow type particle image measurement method ( 12. The image forming method according to claim 11, wherein the average circularity a) is 0.930 or more and less than 0.970.   The image forming method according to claim 1, wherein the circularity of the inorganic fine particles is 0.930 or less.   The image forming method according to claim 1, wherein the inorganic fine particles are rectangular parallelepiped particles.   15. The coating process according to claim 1, wherein the covering step is performed by a rotating member, and the rotating member is driven in a counter direction with respect to the rotation direction of the image carrier at a position where the rotating member contacts the image carrier. The image forming method described.   16. The image forming method according to claim 1, wherein the charging step is a contact charging method or a proximity charging method.   A blade cleaning step in which a blade is brought into contact with the surface of the image carrier to perform cleaning, and the rubbing step and the covering step or the rubbing step or the covering step are performed between the transfer step and the cleaning step. The image forming method according to claim 1, wherein the image forming method is provided.   The image forming method according to claim 17, further comprising: a charge eliminating step for discharging the surface of the image carrier between the transfer step and the cleaning step.   19. The image forming method according to claim 17, wherein a moving time of the surface of the image carrier from the cleaning process to the center of the charging process is 100 msec or less.   The image forming method according to claim 1, wherein the latent image forming step is a back exposure method.