JP4875850B2 - Image forming method - Google Patents

Description

  The present invention relates to an electrophotographic image forming method. More specifically, the electrophotographic photosensitive member is charged, an electrostatic latent image is formed on the charged surface of the photosensitive member, information is written, and the electrostatic latent image on the photosensitive member is converted into a toner image by the developer carried on the developer carrying member. And an image forming method in which a toner image on a photosensitive member is transferred to a transfer member.

  In an image forming method used for an electrophotographic apparatus, an electrostatic recording apparatus, and the like, various methods are known as a method for forming a latent image on a photosensitive member such as an electrophotographic photosensitive member or an electrostatic recording dielectric. For example, in electrophotography, an electrical latent image is formed by uniformly charging a photoconductor using a photoconductive material as a latent photoconductor to the required polarity and potential, and then performing image pattern exposure. In general, the toner is developed and visualized, and this is transferred and fixed to a transfer medium such as paper.

  2. Description of the Related Art In recent years, multifunction devices compatible with a network that include all output terminals such as copying machines, printers, and facsimiles are widely accepted in the market.

  As such a network-compatible output terminal, an electrophotographic system is widely accepted, but one of the major problems is the duty cycle of the main body. The duty cycle is a limit number of sheets in which the main body continues to operate normally without requiring maintenance by an operator.

  One of the biggest factors that control the duty cycle is the life of the photosensitive drum. If the life of the photosensitive drum can be extended, it is possible to reduce waste, that is, reduce consumables, extend the life of consumables, and improve reliability. From the viewpoint of environmental protection, development of such a technology is required.

Under such circumstances, amorphous silicon (a-Si) photoreceptors are increasingly used as photoreceptors. This amorphous silicon photoreceptor has an extremely hard Vickers hardness of 500 or more (500 Kg / m ² or more, JIS standard), and is excellent in durability, heat resistance, and environmental stability. For this reason, it has become indispensable in a high-speed machine that requires particularly high reliability (for example, see Patent Document 1).

  Further, this amorphous silicon photoconductor has an advantage that the number of replacement lifetime is one digit or more higher than that of a generally used OPC photoconductor. That is, since the body life is equivalent, it has an advantage that waste can be reduced. Further, there is no need for labor such as recovery and recovery as in the process cartridge using the OPC photosensitive member.

  However, according to the knowledge of the present inventor, in these devices, it is not limited to toner that adheres to the surface of the photoreceptor and affects the image quality.

  That is, it adheres to the surface of the photosensitive member and affects the image quality because fine paper dust generated from a piece of paper that is often used as a transfer material, organic components precipitated from this, and high-pressure members in the apparatus Corona products generated due to the presence. These fine paper powders, organic components, or corona products adhere to the surface of the photoconductor to form foreign matter, which lowers the resistance particularly in a high humidity environment and prevents the formation of a clear electrostatic latent image. This is considered to be a factor causing image quality degradation.

  It is known that the above-described image deterioration phenomenon is likely to occur particularly in the case of an amorphous silicon (amorphous silicon) photoconductor that is formed by glow discharge decomposition of silanes.

  Therefore, in order to avoid such a deterioration phenomenon in the amorphous silicon photoconductor, particularly when a one-component magnetic toner is used, a magnet is disposed on the upstream side of the cleaning blade along the running direction of the photoconductor in the cleaning device. A method of arranging the rollers has been proposed.

  That is, a magnetic brush is formed by using a part of the toner collected by the cleaning device, and the magnetic brush is brought into contact with the surface of the photosensitive member to re-supply the magnetic toner, whereby the abrasive action on the toner particles at the blade portion is improved. A method has been proposed in which the various foreign substances described above are rubbed and removed.

  This technology not only reduces the local bias on the surface of the photoconductor due to the polishing action, but also a photoconductor, as compared to the method of rubbing the surface of the photoconductor using a separately prepared abrasive such as a web or a rubber roller. There is an advantage that it is possible to suppress the deterioration of the surface.

  In addition, the above-described technique is used in combination with an additional means such as a heater provided on the photoconductor to reduce the ambient humidity during standby at night to prevent a reduction in the resistance of the surface of the photoconductor. It has a certain effect in preventing image degradation based on such causes.

  In an image forming apparatus that repeats the process of transferring a transferable toner image formed on the surface of a photoconductor to a transfer material mainly using paper, the image is transferred to the photoconductor without being transferred to the transfer material at the time of transfer. It is necessary to sufficiently remove the residual toner that remains.

  For this reason, various means have been proposed as cleaning means. A representative one of these means is to scrape off the residual toner described above using a cleaning blade made of an elastic material such as urethane rubber.

  The configuration of the cleaning means using this cleaning blade is not only simple and compact, but also low in cost, and has an excellent toner removal function, so that it is widely used.

  As a rubber material for the cleaning blade, generally, urethane rubber having high hardness and high elasticity, and excellent in abrasion resistance, mechanical strength, oil resistance, and ozone resistance is used. There has also been proposed a technique for improving the cleaning performance by supplying particles conforming to the surface shape of the photoreceptor to such a urethane rubber blade so as to sufficiently exert a lubricating action (see, for example, Patent Document 2).

JP-A-60-67951 Japanese Patent Laid-Open No. 02-101488

  However, the image forming apparatus described above has three major problems.

  That is, firstly, the amorphous silicon photoreceptor has a problem that the surface resistance tends to be lowered. As described above, since the surface resistance of the amorphous silicon photosensitive member is easily reduced, the magnetic brush as described above is formed, brought into contact with the surface of the photosensitive member, and the magnetic toner is supplied again. An apparatus that rubs and removes various foreign substances using the polishing action of toner particles is an effective means for magnetic toners, but is less effective for non-magnetic toners.

  Further, the following factors can be cited as factors that cause image flow. That is, various metal oxides and oxygen compounds at the time of high-energy corona discharge generated from toner, fine paper dust generated from paper used as a transfer material in most cases, organic components precipitated therefrom, and high-pressure members in the apparatus This is a component in which nitrogen in the air is oxidized to form nitrate ions.

  When these foreign substances adhere to the surface of the photoreceptor, a thin film (hereinafter referred to as a filming layer) is formed on the surface of the photoreceptor with durability, absorbs moisture in a high-humidity environment, reduces resistance, and provides a clear electrostatic charge. Prevents the formation of latent images. These are factors causing image quality degradation.

  In order to remove the filming layer due to such durability, it is necessary to improve the rubbing ability of the surface of the photoreceptor. Specifically, when the elastic roll is brought into contact with the surface of the photoconductor with a difference in peripheral speed and rubbed, the toner locally adheres to the surface of the photoconductor. As a result, toner fusion locally occurs on the surface of the elastic roll, and this portion scrapes the surface of the photosensitive member, further causing unevenness and causing defective images.

  In order to avoid such image defects, it is necessary to further improve the rubbing property by the elastic roll on the surface of the photoreceptor. However, according to the knowledge of the present inventor, even if the photoconductor is composed of amorphous silicon, if the rubbing property is improved, the amount of wear increases rapidly and the reliability thereof is lowered.

  Further, with the setting as described above, there is a problem in that the elastic roll itself also increases the amount of wear and decreases reliability.

  Moreover, when this inventor performed the experiment regarding the filming layer formed by the above-mentioned endurance by the optical method, it was confirmed that the film thickness is about 3-8 nm.

  That is, when the present inventor measured the photoconductor with a reflection spectroscopic interferometer (for example, MCDP2000 manufactured by Otsuka Electronics Co., Ltd.), the filming layer was confirmed on the surface oxide layer described above even in the initial durability stage. It was done. The filming layer reached about 3 to 8 nm, and it was confirmed that the film thickness hardly changed after the film thickness was formed.

  However, as the inventor has advanced experiments and durability has progressed, it has been found that image deterioration that has been solved by dry wiping, water wiping, alcohol wiping, or the like in the early stage cannot be solved.

And the adhesive wear by this inventor is performed repeatedly, and with respect to the drum surface whose durability has advanced in such a state, abrasive grains made of cerium oxide (CeO ₂ ) having a particle size of about 0.3 to ₂ μm. It has been found that image degradation cannot be resolved unless the film is polished with an abrasive dispersed in alcohol or the like. Such a phenomenon occurs remarkably particularly when the drum heater is not attached.

  Therefore, the inventor has further studied earnestly, and the initial photoreceptor and the endurance photoreceptor surface having various surface shapes are made into an atomic force microscope (AFM: Digital Instruments), NAnoScopeIIIA Dimension 3000, (Scanning mode: tapping mode, scanning range: 20 μm × 20 μm, probe: Si cantilever).

In the measurement by the present inventor, the surface of the photoconductor after the endurance is almost smooth in appearance due to abrasion as compared with the initial stage. Therefore, the surface of the photoconductor after endurance is heated in a 5% sodium peroxodisulfate (Na ₂ S ₂ O ₈ ) aqueous solution at a temperature of 70 to 80 ° C. for 30 minutes and then ultrasonically cleaned in acetone for about 1 minute. The film was observed after rinsing with ethanol and pure water, and it was confirmed that the filming amount was particularly large in the recesses on the surface of the photoreceptor.

  Second, the present inventor conducted further experiments and found that the frictional force between the transfer residual toner and the drum by the cleaning blade increased due to durability as described above.

  In this regard, the present inventor has further studied and has come to recall that the increase in the frictional force is caused by the filming layer formed by durability.

  That is, the filming layer formed by durability increases the adhesion and affinity between the cleaning blade and the drum surface and between the transfer residual toner and the drum surface, and as a result, the frictional force increases. I came to remember that.

  It is conceivable that the shearing stress of the cleaning blade, the shearing stress between the toners, and the shearing stress in the vicinity of the drum surface increase due to the increase of the frictional force. As a result of these increased shear stresses, local edge chipping of the cleaning blade, so-called chipping, generation of toner and fusion due to increased heat generation due to increased permanent strain shear stress, and increased fatigue wear due to increased internal stress of the drum It is thought that it has led to outbreak.

  Thirdly, in recent years, as described above, image forming apparatuses have been widely used not only as copiers but also as printers.

  In addition, applications such as a feeder function and a sorter function are being enhanced, and a continuous operation of 4000 or more jobs can be performed at one time. For example, even when A4 paper is output at 50 sheets / minute, continuous operation is executed for 80 minutes or more by simple calculation.

  Under such circumstances, the ambient temperature in the vicinity of the photoconductor reaches up to about 50 ° C. It is considered that the temperature of 50 ° C. or higher is reached at the contact (nip) portion between the cleaning blade and the photosensitive member. As a result, the frequency of toner fusion occurring on the surface of the photoreceptor increases.

  An object of the present invention is to provide an image forming method capable of outputting a good image having excellent durability performance without long-term image flow, destruction of a cleaning member, and toner fusion on a high-hardness photoconductor. It is in.

  As a result of intensive studies, the present inventors have found that the surface of a photoconductor having a high hardness such as an amorphous silicon photoconductor is rubbed with an abrasive to solve the above problems. It has been found that image flow, destruction of the cleaning member, and toner fusion can be prevented by appropriately combining the diameter and shape.

  Specifically, by using the following image forming method, a long life can be achieved with a simple apparatus configuration.

The surface of a photoreceptor having a Vickers hardness (JIS standard) of 500 kg / m ² or more was charged by corona charging to form an electrostatic latent image on the photoreceptor, and the electrostatic latent image was developed with toner and developed. In an image forming method for transferring a toner image to a transfer material,
The image forming method includes a cleaning step of removing residual transfer toner remaining on the photoconductor with a cleaning blade, and supplying inorganic fine powder to the photoconductor by a roller member after the transfer and before the cleaning step. And
The photoconductor is an amorphous silicon photoconductor having a photoconductive layer made of a non-single-crystal material based on silicon atoms, and is measured in the range of 10 μm × 10 μm by an atomic force microscope (Q-scope 250). The average inclination Δa of the photoreceptor is 0.1 to 0.9,
The inorganic fine powder is strontium titanate, which is a perovskite-type crystal having a cubic particle shape and / or a rectangular parallelepiped particle shape, and the inorganic fine powder has an average primary particle size of 30 nm to 300 nm. And the content of aggregates having a particle size of 600 nm or more is 1% by number or less,
Assuming that the primary average particle diameter of the inorganic fine powder is D (nm), the relationship between the surface roughness Ra (nm) and the average inclination Δa in the range of 10 μm × 10 μm of the photoreceptor is expressed by the following formula 1 <D / 2Ra
D <4 × (Ra / Δa)
An image forming method characterized by satisfying

  According to the present invention, when the surface of a photoconductor having a high hardness such as an amorphous silicon photoconductor is rubbed with an abrasive to solve the above problems, the surface roughness / shape of the photoconductor and the particle size / shape of the abrasive particles are appropriately set. In combination, the image flow, destruction of the cleaning member, and toner fusion can be prevented, and image formation with high image quality and long life can be performed.

<Image forming process>
FIG. 1 shows an example of an image forming apparatus according to the present invention. FIG. 2 is a longitudinal sectional view showing a schematic configuration of a digital copying machine. The copying machine shown in the figure includes a drum-type electrophotographic photosensitive member 101 as a photosensitive member. The photosensitive member 101 is rotationally driven in the direction of an arrow by a driving unit (not shown). Around the photosensitive member 101, a charging roller 102, which is a primary charging unit, an exposure unit 103, a developing unit (developing unit) 104, and a transfer charging unit (transfer unit) 105 are arranged almost sequentially along the rotation direction. ing. Further, a fixing device 106 is disposed on the downstream side (left side in the figure) of the transfer charger 105 in the conveyance direction (arrow direction) of the transfer material 111. The surface of the photoreceptor 101 is uniformly charged by the primary charger 102. Next, image exposure is performed by the laser beam emitted from the exposure means 103, the electric charge of the laser beam irradiated portion is removed, and an electrostatic latent image is formed. The electrostatic latent image on the photoconductor 101 is developed with the charged toner of the developing device 104. The developed toner image on the photoreceptor 101 is transferred by the transfer charger 105 to the transfer material 111 conveyed in the direction of the arrow. After the toner image is transferred, the transfer material 111 is conveyed to a fixing device 106 where the toner image is fixed on the surface by being heated and pressurized. The untransferred toner remaining on the photosensitive member after the transfer is collected and removed by an elastic cleaning blade in contact with the counter of the drum of the cleaning device 107.

  The cleaning device 107 is means for collecting and cleaning the transfer residual toner remaining on the photoconductor after the toner transfer. For example, an elastic blade mainly made of polyurethane rubber is brought into contact with the rotation of the photosensitive member by a counter as shown in FIG. The toner and lubricant scraped off by the cleaning blade are received by a scooping sheet and sent to a waste toner box by a toner feed blade, a brush roller, a screw and the like.

<Inorganic powder supply member>
In the present invention, the inorganic powder supply member for the photoconductor supplies an abrasive to the photoconductor to prevent image flow and improve the cleaning property.

  The inorganic powder supply member may be supplied from anywhere on the photoreceptor. It can be attached to the toner as an external additive and supplied together with the toner during development. The charging device and the transfer device may also serve as the inorganic powder supply.

  FIG. 2 shows a schematic sectional view of a cleaning device of an image forming apparatus that supplies inorganic particles in the cleaning process. In this example, the molded solid abrasive particles 204 are pressed against the brush roller 203 and scraped off, applied to the photoreceptor 201, and supplied to the contact portion with the cleaning blade 202.

<Electrophotographic photoreceptor>
FIG. 3 shows an example of the electrophotographic photosensitive member in the present invention.

  The electrophotographic photosensitive member of this example is obtained by sequentially laminating a photoconductive layer 302 and a surface protective layer 303 on a base 301 made of a conductive material such as Al or stainless steel (see FIG. 3A).

  In addition to these layers, various functional layers such as a lower charge injection blocking layer 304, an upper charge injection blocking layer 305, a charge injection layer, and an antireflection layer can be provided as necessary. For example, by providing the lower charge injection blocking layer 304, the upper charge injection blocking layer 305, and the like and selecting a group 13 element or a group 15 element as a dopant, it is possible to control the charge polarity such as positive charge and negative charge. (See FIG. 3B).

  The substrate shape may be as desired according to the driving method of the electrophotographic photosensitive member. As the base material, conductive materials such as Al and stainless are generally used. However, for example, by depositing these conductive materials on non-conductive materials such as various plastics and ceramics, the conductivity can be improved. Those provided can also be used.

  A typical example of the photoconductive layer 302 is an amorphous material (also abbreviated as “a-Si (H, X)”) containing, for example, silicon atoms and hydrogen atoms or halogen atoms. Further, the layer thickness of the photoconductive layer 302 is not particularly limited, but about 15 to 50 μm is appropriate in consideration of the manufacturing cost.

  Further, in order to improve the characteristics, a plurality of layer structures such as a lower photoconductive layer 306 and an upper photoconductive layer 307 may be used (see FIG. 3B).

  The surface protective layer 303 is generally a non-single crystal (preferably amorphous) material a-SiC (H, X) containing a silicon atom as a base and containing a carbon atom and, if necessary, a hydrogen atom or a halogen atom. A non-single crystal (preferably amorphous) material a-SiN (H, X) containing a silicon atom as a base, a nitrogen atom and a hydrogen atom or a halogen atom as required, or a carbon atom as a base, If necessary, it is formed of non-single crystal carbon (preferably amorphous carbon) a-C (H, X) containing a hydrogen atom or a halogen atom.

  Alternatively, the interface between the photoconductive layer 302 and the surface protective layer 303 may be continuously changed, and an antireflection layer may be provided to control the interface reflection of the portion.

<A-Si photoconductor film forming apparatus>
An a-Si photoconductor film forming apparatus, a method for forming an amorphous silicon photoconductor, and its procedure will be described below.

  The a-Si photosensitive member can be formed by a plasma CVD apparatus using high-frequency power in the RF band (13.56 MHz) that has been widely used in the past. However, in order to realize an a-Si photosensitive member having a fine shape as disclosed in the present invention, it is more desirable to set the frequency of the high-frequency power source to the VHF band (50 to 450 MHz).

  The plasma CVD apparatus shown in FIGS. 4 and 5 shows a preferred example of the a-Si photosensitive film forming apparatus in the present invention.

  FIG. 4 shows an apparatus system for forming an electrophotographic photosensitive member using amorphous silicon as a base material using high-frequency power in the VHF band. The apparatus system includes at least a reaction vessel 402 capable of containing a cylindrical substrate 401, a gas pipe 417 for supplying a raw material gas into the reaction vessel 402, and a cathode 414 for introducing electric power for decomposing the raw material gas. A deposited film forming apparatus 400, a gas supply system 404 for supplying a source gas into the reaction container 402, an exhaust system 405 for exhausting the reaction container 402, and a power supply system 406 for supplying power to the cathode 414.

  FIG. 5 shows a cross-sectional view of the deposited film forming apparatus 400.

  First, the cylindrical substrate 401 is installed on the substrate support 403 incorporating the heater in the reaction vessel 402, and the reaction vessel 402 is evacuated by the exhaust pump 407 through the exhaust port 419, and the evacuation is completed to a desired degree of vacuum. After that, an inert gas such as He gas or Ar gas is supplied into the reaction vessel 402 at a predetermined flow rate by a mass flow controller in the source gas supply system 404. The inside of the reaction vessel 402 is controlled to a desired pressure by adjusting the exhaust speed of the exhaust pump 407.

  After the internal pressure of the reaction vessel 402 is set to a desired pressure, the cylindrical substrate 401 is heated to a desired temperature by a heater built in the substrate support 403. During the formation of the deposited film, it is kept at a desired temperature necessary for forming the deposited film.

After the heating process is completed by the above procedure, a deposited film forming process is subsequently performed. After the inert gas in the reaction vessel 402 is exhausted by the exhaust pump 407, the exhaust valve 408 is closed, the main exhaust valve 409 is opened, the throttle valve 410 is fully opened, and the main exhaust pump through the oil diffusion pump 411 is used. The inside of the reaction vessel 402 is evacuated to 4 × 10 ⁻³ Pa, for example, by 412.

  Subsequently, each source gas is supplied into the reaction vessel 402 at a predetermined flow rate by a source gas supply system 404 by a mass flow controller installed in each supply pipe. By adjusting the opening degree of the throttle valve 410 and adjusting the exhaust speed, the internal pressure of the reaction vessel 402 is controlled to a desired pressure. When the internal pressure of the reaction vessel 402 is stabilized, power is supplied from the power source 413 to the cathode 414 via the matching box 415 to cause glow discharge in the reaction vessel 402.

  By this discharge energy, the source gas introduced into the reaction vessel 402 is decomposed, and a predetermined deposited film is formed on the cylindrical substrate 401. In order to improve the uniformity of the deposited film in the circumferential direction of the substrate, a method in which the substrate 401 is rotated at a predetermined speed by the motor 416 via the driving unit 418 during the formation of the deposited film is effective. The unevenness in the circumferential direction of the silicon photoconductor can be easily reduced within an allowable range. In this way, when the deposited film reaches a desired film thickness, the supply of electric power applied to the cathode 414 is stopped, and the supply of the source gas from the source gas supply system 404 is stopped to complete the formation of the deposited film.

  By repeating the same operation a plurality of times, it becomes possible to form a deposited film having a multilayer structure.

  As described above, in order to produce an a-Si photosensitive member suitable for the present invention, it is more desirable to set the frequency of the high frequency power source to the VHF band (50 to 450 MHz). As a result of intensive studies by the present inventors using the above apparatus, in an a-Si photosensitive member produced with a 13.56 MHz high frequency power source, Ra measured in the range of 10 μm × 10 μm is 15 to 40 nm, similarly 10 μm × 10 μm. Δa measured in the range of 0.1 to 0.3 was in the range of 0.15 to 0.3, whereas in an a-Si photosensitive member manufactured with a high frequency power source in the range of 50 to 450 MHz, Ra was 5 to 68 nm, Δa Can be manufactured in a wider range of 0.05 to 0.65, and the surface roughness is controlled within the above range according to film forming parameters such as input power, substrate temperature, and bias potential. Became possible.

  Furthermore, in the a-Si photosensitive member manufactured with a high frequency power source in the range of 50 to 150 MHz, the surface roughness is controlled independently within the above range by film forming parameters such as input power, substrate temperature, and bias potential. It became easy to produce.

  Therefore, in order to realize a desired fine shape in the a-Si photosensitive member in the present invention, it is desirable that the frequency of the high-frequency power is in the range of 50 to 450 MHz. More preferably, a range of 50 to 150 MHz is desirable.

  The surface shape of the photoreceptor was measured by using an atomic force microscope (AFM) “Q-scope 250 manufactured by Questant”. The surface roughness indicates the value of the surface roughness Ra according to the above evaluation, and the average inclination Δa indicates a value calculated from the three-dimensional shape.

  In addition, in the surface observation of the cylindrical photoreceptor, the Q-scope 250 was subjected to the tilt removal mode, and the curvature of the AFM image of the sample was fitted to a parabola and then flattened (parabolic). Further, correction (Line by Line) for removing the inclination may be performed.

  Regarding the visual field, the same sample was evaluated with various visual fields other than 10 μm × 10 μm. When the field of view is enlarged, the Ra measurement value is stabilized, but the microscopic surface shape is less likely to be reflected due to the influence of the singular shape such as the undulation of the sample substrate, the projection, and the like. On the other hand, when the field of view is narrowed, the variation in the measurement location increases. The same applies to Δa.

  In the present invention, the result of the 10 μm × 10 μm field of view, which is excellent in the above detection capability and reproducibility overall performance, is used.

  The microscopic surface shape (Ra, Δa) can be controlled by changing discharge power, substrate temperature, total film thickness, and the like.

The Vickers hardness of the photoreceptor is measured by a measuring method according to JIS standard B7774. When the Vickers hardness is 500 kg / m ² or more, it is sufficiently hard and the fine surface shape described above can be maintained for a long time. If it is less than 500 kg / m ² , the growth of wear and scratches is rapid and it becomes difficult to maintain the surface shape.

  The microscopic surface shape Δa is preferably in the range of 0.1 to 0.9.

  If it is less than 0.1, the releasability from the toner is small, and transfer / cleaning becomes difficult. Further, when the cleaning blade comes into contact with the counter, it becomes easy to bend. If it is larger than 0.9, it becomes difficult to mechanically remove the deposits in the recesses (grooves) caused by the fine surface roughness.

<Abrasive particles>
Accordingly, as a result of intensive studies by the present inventors, inorganic fine powder, which is a perovskite crystal having an average primary particle size of 30 nm to 300 nm and having a cubic or rectangular parallelepiped shape, is adhered to the surface of the photoreceptor. In addition, the present inventors have found that, by interposing between the contact member and rubbing, deposits such as discharge generation substances, paper powder, and toner on the high-hardness photoreceptor can be removed, and image flow and clean blade chipping can be prevented.

  The abrasive particles used in the present invention preferably have perovskite crystals. Among the perovskite-type abrasive particles, strontium titanate, barium titanate, and calcium titanate are more preferable, and strontium titanate is more preferable.

  The perovskite type abrasive particles used in the present invention preferably have an average primary particle size of 30 nm to 300 nm. If the average particle size is less than 30 nm, the polishing effect in the cleaner portion is insufficient, while if it exceeds 300 nm, scratches are likely to occur when the photosensitive member is sandwiched between contact objects such as a cleaning blade, a roller, and a transfer object.

  In addition, the inorganic fine powder does not necessarily exist as primary particles on the surface of the colored particles, and may exist as aggregates. However, particularly when externally added to the toner, aggregates having a particle diameter of 600 nm or more are present. The content is preferably 1% by number or less.

  If aggregates having a particle diameter of 600 nm or more are contained in the state of being externally added to the toner, even if the primary particle diameter is 300 nm or less, scratches on the photoreceptor are likely to occur, which is not suitable. The particle size of the perovskite abrasive particles in the present invention was determined by measuring 100 particle sizes from a photograph taken at a magnification of 50,000 times with an electron microscope. The particle diameter was determined by (a + b) / 2, where a is the longest side of the primary particles and b is the shortest side.

  Perovskite-type abrasive particles can be surface-treated to make it difficult to fuse with a photoreceptor or a developing roller.

The number of carbon atoms of the fatty acid or fatty acid metal salt for surface-treating the perovskite-type abrasive particles is preferably 8 or more and 35 or less, and more preferably 10 or more and 30 or less. When the number of carbon atoms exceeds 35, the adhesion between the surface of the inorganic fine powder of the perovskite crystal and the fatty acid or fatty acid metal salt is inferior, and the durability deteriorates due to the occurrence of peeling due to long-term use. Fatty acids or fatty acid metal salts are not preferred because they cause fogging. On the other hand, when the number of carbon atoms is less than 8, it is not preferable because the adhesion of fine particles having a specific surface area of 100 m ² / g to 350 m ² / g is insufficient.

  Moreover, the preferable processing amount of a fatty acid or a fatty acid metal salt is 0.1 mass% or more and 15 mass% or less with respect to a base material, More preferably, it is 0.5 mass% or more and 12 mass% or less.

  In addition, when the surface treatment of perovskite-type abrasive particles is performed using a treatment agent such as a silicone oil, a silane coupling agent, or a titanium coupling agent that is generally used to improve the hydrophobicity of the external additive, the aforementioned adhesion There was no improvement in sex. This is because fatty acids or fatty acid metal salts have excellent releasability and improve adhesion, while silicone oil, silane coupling agents, titanium coupling agents, etc. have excellent hydrophobicity, but release It seems to be inferior.

When the perovskite-type abrasive particles are externally added to the toner, the perovskite-type treated with the present invention is used to prevent the influence of the moisture absorption of the inorganic fine powder in a high-humidity environment on the development process, for example, the reduction in the toner charge amount The specific surface area of the abrasive particles is preferably 45 m ² / g or less. By setting the specific surface area to 45 m ² / g or less, the absolute amount of water adsorbed on the surface of the inorganic fine powder can be kept small, so that the influence on the toner charge imparted by frictional charging can be reduced.

  In addition, the specific surface area of this invention was computed using the BET multipoint method using the autosorb 1 (made by Yuasa Ionics).

Furthermore, in order to prevent fine particles having a specific surface area of 100 m ² / g or more and 350 m ² / g or less from adhering to the surface of the perovskite abrasive particles in a low humidity environment, the contact angle of the perovskite abrasive particles treated with the present invention with water. Is more preferably 110 ° or more and 180 ° or less.

The contact angle measurement method is as follows. Perovskite abrasive particles were pressed by a tablet molding machine at a pressure of 300 KN / cm ^{2 to} obtain a sample having a diameter of 38 mm. At the time of molding, NP-Transparency TYPE-D was sandwiched between the molding machine and the sample. This sample was allowed to stand at 23 ° C. and 100 ° C. for 2 minutes and then returned to room temperature, and the contact angle was measured with a roll material contact angle meter CA-X roll type (manufactured by Kyowa Interface Chemical Co., Ltd.). The measurement was performed 20 times per sample, and the average value of 18 measured values excluding the maximum value and the minimum value was used.

In order to improve developability, the absolute value of the charge amount of the perovskite abrasive particles subjected to the surface treatment of the present invention is preferably 10 mC / kg or more and 80 mC / kg or less, and the charge polarity is 100 m in specific surface area. ^The polarity is preferably opposite to that of the fine particles of ² / g or more and 350 m ² / g or less.

  The method for measuring the charge amount is as follows.

Using a DSP 138 (manufactured by Dowa Iron Industries Co., Ltd.) as a carrier at a temperature of 23 ° C. and a relative humidity of 60%, a mixture obtained by adding 0.1 g of the sample to be measured to 9.9 g of the carrier is placed in a 50 ml capacity polyethylene bottle. Shake 100 times. Next, as shown in FIG. 8, about 0.5 g of the mixture is put in a metal measuring container 2 having a screen 3 of a metal mesh having a mesh opening of 32 μm at the bottom, and a metal lid 4 is formed. The total mass of the measurement container 2 at this time is weighed and is defined as W1g. Next, in the suction machine (at least the insulator is in contact with the measurement container 2), the pressure of the vacuum gauge 5 is set to 250 mmAq by suction from the suction port 7 and adjusting the air volume control valve 6. In this state, suction is performed for 2 minutes, and the sample to be measured is removed by suction. The potential of the electrometer 9 at this time is set to V (volt). Here, 8 is a capacitor, and the capacity is C (μF). Moreover, the mass of the whole measuring machine after suction is weighed and is defined as W2 (g). The triboelectric charge amount (mC / kg) of the sample to be measured is calculated as follows.
Frictional charge amount = CV / (W1-W2)

  The perovskite-type abrasive particles used in the present invention are prepared by adding strontium hydroxide to a titania sol dispersion obtained by adjusting the pH of a hydrous titanium oxide slurry obtained by, for example, hydrolyzing an aqueous solution of titanyl sulfate. It can be synthesized by heating up to.

  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, it is preferable to add an alkaline substance such as sodium hydroxide to the titania sol dispersion. 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 about 60 ° C to 100 ° C. 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.

  The inorganic particles thus produced can be obtained as perovskite crystals having a cubic or rectangular parallelepiped shape. When the particle shape is a cubic shape or a rectangular parallelepiped shape, the contact area with the surface of the photoreceptor can be increased, and a good scraping property by the solid ridgeline can be obtained. Further, by effectively using the particle size and the three-dimensional ridgeline and corner according to the surface shape of the photoconductor, it is possible to prevent deposits from depositing on fine irregularities when the photoconductor is particularly difficult to wear.

  Furthermore, at the same time as removing the adhering matter to the photosensitive member, it serves as a lubricant by appropriately slipping only the abrasive between the cleaning blade and the photosensitive member, thereby enabling the cleaning blade to be used for a long time.

  An example of an electron micrograph (magnification of 20,000 times) of the perovskite abrasive particles of the present invention is shown in FIG.

<Toner>
The method for producing the toner of the present invention is not particularly limited, and a suspension polymerization method, an emulsion polymerization method, an association polymerization method, a kneading and pulverization method, and the like are used.

  Further, the toner of the present invention can provide a sufficient effect in both cases of non-magnetic toner and magnetic toner.

  A method for producing toner in the kneading and pulverizing method will be described below.

  Examples of the binder resin used in the pulverized toner of the present invention include polystyrene, poly-α-methylstyrene, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, and styrene-vinyl acetate. Copolymers, styrene-acrylic acid ester copolymers, styrene-methacrylic acid acrylic copolymers, vinyl chloride resins, polyester resins, epoxy resins, phenol resins, polyurethane resins, etc. can be used alone or in combination. -Acrylic, styrene-methacrylic copolymer resin and polyester resin are preferred.

  Further, when the pulverized toner of the present invention is controlled to be positively charged, a modified product of a fatty acid metal salt or the like; 4 such as tributylbenzidyl ammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, etc. Onium salts such as quaternary ammonium salts and their analogs such as phosphonium salts; amines and polyamine compounds; metal salts of higher fatty acids; acetylacetone metal complexes; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, and dicyclohexyltin oxide Diorgano tin borate such as dibutyl tin borate, dioctyl tin borate, dicyclohexyl tin borate and the like are added. Moreover, when controlling to negative chargeability, an organometallic complex and a chelate compound are effective, and a monoazo metal complex, an acetylacetone metal complex, an aromatic hydroxycarboxylic acid, and an aromatic dicarboxylic acid metal complex can be used. The amount used is 0.1 to 15 parts by mass, preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the binder resin.

  A release agent can be added to the pulverized toner of the present invention as necessary. For example, aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, paraffin wax, and Fischer-Tropsch wax or oxides thereof; waxes mainly composed of aliphatic esters such as carnauba wax and montanic acid ester wax; And those obtained by deoxidizing some or all of them. In addition, saturated linear fatty acids such as palmitic acid, stearic acid, and montanic acid; unsaturated fatty acids such as brassic acid, eleostearic acid, and valinalic acid; stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnauvir alcohol, and seryl alcohol , Saturated alcohols such as melyl alcohol; polyhydric alcohols such as sorbitol; fatty acid amides such as linoleic acid amide; saturated fatty acid bisamides such as methylene bis stearic acid amide; unsaturated fatty acid amides such as ethylene bisoleic acid amide Aromatic bisamides such as N, N′-distearylisophthalic acid amide; fatty acid metal salts such as zinc stearate; waxes grafted to a hydrocarbon hydrocarbon wax using a vinyl monomer such as styrene; Fatty acids with polyhydric alcohols partial esters of such Henin acid monoglyceride; and methyl ester having a hydroxyl group obtained by and hydrogenated vegetable oils may also be used. The addition amount is 0.1 to 20 parts by mass, preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the binder resin.

  Next, in the case of non-magnetic toners, these binder resins, mold release agents, charge control agents, colorants, etc., and in the case of magnetic toners, magnetic substances are used in place of the above colorants, or colorants as required. And a magnetic material are sufficiently mixed by a mixer such as a Henschel mixer or a ball mill, and then melted and kneaded using a heat kneader such as a heating roll, a kneader or an extruder to charge the resin while the resins are compatible with each other. A control agent and a colorant are dispersed or dissolved, and after cooling and solidification, the particles are mechanically pulverized to a desired particle size, and the particle size distribution is sharpened by classification. Alternatively, after cooling and solidification, a finely pulverized product obtained by colliding with a target under a jet stream is spheroidized by heat or mechanical impact force.

Fine particles having a specific surface area of 100 m ² / g or more and 350 m ² / g or less are externally added to the colored particles thus obtained. The fine particles are inorganic particles such as metal oxides such as silicon, magnesium, zinc, aluminum, titanium, iron and zirconium; metal salts such as barium sulfate, calcium carbonate, magnesium carbonate and aluminum carbonate; clay minerals such as kaolin; apatite Phosphoric acid compounds such as silicon compounds such as silicon carbide and silicon nitride; and carbon powders such as carbon black and graphite. Organic particles and composite particles include polyamide resin particles, silicone resin particles, silicone rubber particles, urethane particles, melamine-formaldehyde particles, acrylic particles, etc .; rubber, wax, fatty acid compounds, resins, etc., metals, metals Composite particles composed of inorganic particles such as oxides, salts, carbon black, etc .; fluorine resins such as polyfluorinated ethylene and polyvinylidene fluoride; fluorine compounds such as carbon fluoride; fatty acid metal salts such as zinc stearate; Examples include fatty acid derivatives such as fatty acid esters; molybdenum sulfide, amino acids and amino acid derivatives.

The toner of the present invention is obtained by adding fine particles having a specific surface area of 100 m ² / g or more and 350 m ² / g or less to colored particles comprising at least a colorant and a binder resin. This is necessary for imparting appropriate fluidity and chargeability to the toner. If the specific surface area of the fine particles is less than 100 m ² / g, sufficient fluidity cannot be obtained, which is not preferable. Further, if the specific surface area of the fine particles exceeds 350 m ² / g, the charging becomes too high particularly in a low humidity environment, and filming on the photosensitive member is likely to occur, which is not preferable.

  The developing method using the toner of the present invention is not particularly limited. For example, a two-component developing method using a nonmagnetic toner manufactured by the above manufacturing method mixed with a carrier, a nonmagnetic one using only a nonmagnetic toner without using a carrier. Examples thereof include a component development method and magnetic one-component development using a magnetic toner.

<Latent image forming device>
In order to improve the image quality, it is necessary to make the spot diameter of the laser beam as small as possible. However, in a semiconductor laser having an oscillation wavelength in the near infrared region used as a light source, it is difficult to obtain a clear spot contour even if the beam diameter is reduced by operating the optical system. The cause is that the spot diameter D is directly proportional to the wavelength λ of the laser beam (D = 1.22λ / NA (NA is the numerical aperture of the lens)), and the wavelength of the laser beam itself. Therefore, to improve the image quality, it is effective to shorten the wavelength of the laser beam itself.

  The exposure means may include a light source that emits a laser having a wavelength of 600 nm or less, preferably 500 nm or less, more preferably 450 nm or less. As the light source, a semiconductor laser is preferable because the light source itself is small and the entire apparatus can be miniaturized. Examples of such a semiconductor laser include a gallium nitride semiconductor laser having a multi-quantum well structure and a laser whose wavelength is shortened by a nonlinear optical element.

  More specifically, an InGaN-based semiconductor laser (manufactured by Nichia Chemical Industries, Ltd.), a GaN-based semiconductor laser, an AlGaN-based semiconductor laser, etc., which has been developed at Nichia Chemical and outputs a main wavelength of 410 nm. Specific examples of the nonlinear optical element include a nonlinear optical element (manufactured by Matsushita Electric Industrial Co., Ltd.) that outputs a main wavelength of 425 nm. This non-linear optical element is a non-linear optical element that emits the second harmonic of 425 nm by making the output light of a 850 nm near-infrared semiconductor laser incident on a magnesium oxide-added lithium niobate crystal.

  The exposure means includes a beam converging means for emitting laser light from a light source using an ultraviolet blue-violet laser, a non-linear optical element, etc., and converging it on the electrophotographic photosensitive member, and a beam for scanning the electrophotographic photosensitive member. It is preferable to provide scanning means.

  The exposure unit is preferably a digital type exposure unit that performs exposure based on a digitally processed image signal. The digital exposure means for performing exposure based on the digitally processed image signal uses the exposure light source such as the above-mentioned ultraviolet blue-violet laser, nonlinear optical element, etc., and performs binarization or pulse width modulation or intensity modulation. It is an exposure means for performing exposure with the digitized light.

  The image forming apparatus of the present invention uses laser light having a short wavelength as the exposure means (light source) as described above, so that the diffusion of the spot of the laser beam can be suppressed as compared with a conventional semiconductor laser, and extremely high resolution. Images can be written.

  Lasers are known to scatter more easily than white light because their phases are aligned, and the scattering intensity is known to be proportional to the fourth power of the reciprocal of the wavelength when the scattering material is small. It has been. In other words, when a blue laser is used, scattering due to fine particles attached to the surface or added to the surface protective layer increases, so that even when writing on the electrophotographic photosensitive member with a high-density spot, it reaches the charge generation layer. There are problems such as disturbance of the light spot and reduction in the amount of light.

  At present, blue semiconductor lasers have much lower exposure power and are more expensive than red semiconductor lasers. Therefore, in order to make full use of the characteristics of the blue laser capable of reducing the spot diameter, it is necessary to reduce the amount of light reaching the charge generation layer, the spot disturbance, and the like as much as possible.

  When writing a latent image with a laser, the shorter the laser wavelength, the more easily affected by the size of fine irregularities on the surface of the medium to be written, and light scattering tends to occur. Therefore, in order to prevent the latent image from blurring due to light scattering, it is advantageous to make the unevenness as small as possible in the formation of the latent image using the short wavelength laser in the electrophotographic photosensitive member. In particular, when fine particles or the like are attached to the surface of the photoconductor, irregularities due to the presence of the particles occur and scattering is likely to occur.

<Relationship between perovskite-type abrasive particles and photoreceptor surface shape>
As shown in FIG. 7, the surface roughness expressed by “Ra” can actually be regarded as having a concave portion having a depth of “2Ra”. In order to remove the deposits present in the concave portion, it is necessary that the abrasive particles first enter the concave portion. The average value of the size of the concave portion and the distance between the convex portions is expressed by “2 × 2Ra / Δa”, which is sufficient to easily rub the concave portion with the ridge line of the abrasive particles when the abrasive particles are smaller than this. Scraping effect can be obtained.

  Further, if the abrasive particles have a particle size smaller than the depth “2Ra” of the concave portion, when entering the concave portion, it becomes difficult to move from there, so that it is difficult to obtain a polishing effect.

  Specifically, the size relationship of (1) shown in FIG. 7 is desirable, and if it is the relationship of (2) and (3), it is difficult to obtain a sufficient scraping effect.

  In addition, the abrasive particles in the present invention are sufficiently smaller than a general electrophotographic toner particle size of several to several tens of μm, and slip through little by little at a cleaning pressure that is generally performed. The abrasive particles that have passed through the cleaning step are loosened in powder aggregation and uniformly adhered to the photoconductor, which may hinder exposure for latent image formation.

  The light loss in the photoconductor includes internal absorption, surface scattering, interface scattering, internal scattering and the like in each layer. In particular, surface scattering is mainly caused by surface roughness due to grain boundaries.

  In general, light scattering is classified into types such as Rayleigh scattering if the particle or surface roughness is 1/10 or less of the wavelength of light, and Mie scattering if the particle size is comparable, but compared to the wavelength. The degree of scattering (spreading / strength) increases as the particle / roughness increases.

The total microscopic average surface roughness formed from the perovskite-type abrasive particles adhering to the photoreceptor surface and the photoreceptor surface shape is represented by (D + 2Ra) nm .

Accordingly, in the present invention, it is preferable that the microscopic average surface roughness is (D + 2Ra) nm sufficiently small with respect to the wavelength, and from the examination results, the microscopic average surface roughness is (D + 2Ra) being two minutes of the wavelength. It was confirmed that when the ratio was smaller than 1, the influence on the electrophotographic image was small, and the deterioration of dot reproducibility due to laser scattering could be suppressed.

  Hereinafter, the features of the present invention will be described specifically by way of examples. Part means part by mass.

<Photoconductor production example>
An a-Si comprising a charge injection blocking layer, a photoconductive layer, and a surface layer on an aluminum cylinder having a mirror finish of φ30, using an apparatus for manufacturing a photoconductor for an electrophotographic apparatus by a high frequency plasma CVD method using a VHF band. A photoconductor was prepared. Further, various photoconductors having different surface shapes were prepared by changing the film formation conditions of the mixing ratio and total flow rate of SiH ₄ and H ₂ of the photoconductive layer, discharge power (plasma power), and substrate temperature. The surface layer was a-SiN.

Thus, photoconductors A to L were obtained. The obtained photoreceptor had a Vickers hardness (JIS standard) of 1200 kg / m ² . Table 1 shows the microscopic surface roughness Ra and Δa of the surface.

<Production example of perovskite-type abrasive particles>
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 0.65 to obtain a titania sol dispersion. NaOH was added to the titania sol dispersion, the pH of the dispersion was adjusted to 4.5, and washing was repeated until the electrical conductivity of the supernatant reached 70 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. Further distilled water was added so as to 0.1～2.0Mol / liter terms of SrTiO _3.

  The slurry was heated to 83 ° C. at a rate of 5 to 30 ° C./hour in a nitrogen atmosphere, and reacted for 3 to 7 hours after reaching 83 ° C. After the reaction, cool to room temperature, remove the supernatant, and repeat washing with pure water.

  Further, in a nitrogen atmosphere, the slurry was placed in an aqueous solution in which 6.5% by mass of sodium stearic acid (18 carbon atoms) was dissolved with respect to the solid content of the slurry. Zinc stearate was deposited on the mold crystal surface.

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

  Various strontium titanates having different average particle diameters were obtained by varying the temperature rising rate and reaction time of the slurry.

  The obtained strontium titanate had an average primary particle size of 75, 110, 165, and 190 nm, and an aggregate content of 600 nm or more was 0.5% by number. The content of particles having a cubic or rectangular parallelepiped shape was 80% by number or more.

<Examples of colored particle production>
Styrene acrylic resin 100 parts (styrene-butyl acrylate copolymer ratio = 78: 22)
Magnetic material 90 parts Salicylic acid metal compound 2 parts Paraffin wax 3 parts The above is mixed using a Henschel mixer, melt kneaded with a twin screw extruder kneader, coarsely pulverized with a hammer mill, and finely pulverized with a jet mill. Classification was performed to obtain colored particles having an average particle diameter of 7 μm.

<Evaluation method>
Evaluation of image flow was performed with a Canon digital copier GP405 corona charging remodeling machine under the environment of temperature 30 ° C and humidity 80% RH. After the main body power was turned off, the digital halftone image and the 5-point character image after being left for 12 hours in the same environment were evaluated. The evaluation results were ranked as follows.
○: No image flow △: Halftone highlight skipping is slight, but characters are no problem ×: Halftone highlight is completely skipped, characters are blurred and cannot be read

  Durability evaluation of the cleaning blade was performed at a temperature of 30 ° C and humidity of 80% RH, and the Canon digital copier GP405 corona charging machine was used to print 100,000 sheets of 5% images, and cleaning was performed at that time. The slipping through the blade edge breakage was performed by observing a solid white image after the solid black paper was passed.

The blade edge was observed with a microscope to confirm the position of destruction, and was made to correspond to the slip-through position.
○: No slipping at all △: Slightly slipping through, but almost inconspicuous in the image ×: There is slipping through, conspicuous in the image

In some cases, the abrasive particles passed through the cleaning blade moved from the surface of the photosensitive member to the charging device and adhered, resulting in contamination. The examples were also evaluated for contamination of the charging device. Under the environment of temperature 30 ° C and humidity 80% RH, Canon digital copying machine GP405 corona charging remodeling machine was able to print 100,000 sheets of 5% images, and the following criteria for charging device contamination at that time Evaluated.
A: No contamination at all O: Abrasive particles are attached to the charging device but have no effect on the image Δ: Abrasive particles are attached to the charging device, and the image is slightly affected but not noticeable ×: Abrasive particles Is attached to the charging device, affecting the image

  The dot reproduction affected by light scattering was evaluated as follows.

After the photosensitive member was charged to −400 V, a latent image was written using a dye laser through 400 nm and 500 nm wavelength linear masks having a width of 40 μm. Using an electrostatic latent image analyzer produced by applying the SFM described in the Journal of the Electrophotographic Society, Vol. 32, No. 4, 62 (1993), this is perpendicular to the electrostatic latent image. Scanned and analyzed the electrostatic latent image. The width of the electrostatic latent image was defined as the width between positions where the potential decay rate was 1/20 of the potential decay rate at the exposure center.
○: Electrostatic latent image width 48 μm or less 1 dot reproducibility △: Electrostatic latent image width 60 μm or less 48 μm or more X: Electrostatic latent image width 60 μm or greater 1 dot poor reproduction

[Example 1]
<Example of providing a perovskite-type abrasive particle supply member and attaching it to a photoreceptor>
As a supply member, perovskite-type abrasive particles are supplied from the upstream side of the cleaning device cleaning blade shown in FIG. The amount of scraping was adjusted so that the perovskite-type abrasive particle supply rate was 2 g per 1000 A4 paper.

With respect to 100 parts of the colored particles, 1.2 parts of hydrophobic silica (BET = 220 m ^{2 /} g) which is 100 parts of silica and surface-treated with 20 parts of dimethyl silicone oil are subjected to rotation at 66S ⁻¹ with a Henschel mixer FM10B. Time: Toner A was obtained by external addition under conditions of 3 minutes, and this was used for actual image printing.

  Table 2 shows the results obtained by varying the values of the photoconductors A to L and D.

Regarding the relationship between the primary average particle diameter D (nm) of the perovskite-type abrasive particles, the surface roughness Ra (nm) in the range of 10 μm × 10 μm of the photoreceptor and the average inclination Δa, the following formula 1 <D / 2Ra D <4 × (Ra / Δa)
Satisfying the above can prevent the image from flowing and obtain a good cleaning performance.
Further, regarding the maximum light intensity wavelength λ ( nm ) , surface roughness Ra ( nm ) and primary average particle diameter D ( nm ) of the perovskite-type abrasive particles output from the exposure means, the following formula D + 2 × Ra ≦ λ / 2
Satisfying the above, it is possible to obtain good dot reproduction even in exposure with a short wavelength laser.

  In this example, strontium titanate was used as the abrasive particles, but the same effect can be obtained with barium titanate and calcium titanate.

  In this embodiment, a-SiN is used as the surface layer of the photoreceptor, but the same effect can be obtained with a-C, a-SiC, or MgF.

[ Reference Example 1 ]
<Example of using perovskite-type abrasive particles externally added to toner>
With respect to 100 parts of colored particles, 1.2 parts of hydrophobic silica (BET = 220 m ^{2 /} g) surface-treated with 100 parts of silica and 20 parts of dimethyl silicone oil, and inorganic fine powder at Henschel mixer FM10B Was added externally under the conditions of: 66S ⁻¹ , and time: 3 minutes to obtain a toner B. The amount of the perovskite abrasive particles added to the colored particles was 0.04% by mass to 5.2% by mass.

  This toner was used in the developing device of the image forming apparatus described above, and an actual image output evaluation was performed according to the previous evaluation method in the same manner as in Example 1. The evaluation results are shown in Tables 3-7.

As described above, in the case of using toner with externally added perovskite-type abrasive particles, the primary average particle diameter D (nm) , the surface roughness Ra (nm) of the photoreceptor in the range of 10 μm × 10 μm, and the average inclination Regarding the relationship with Δa, the following formula 1 <D / 2Ra D <4 × (Ra / Δa)
By satisfying the above, it is possible to prevent image flow and improve the cleaning performance without the need for a rubbing member such as a cleaning magnetic brush.

Further, regarding the maximum light intensity wavelength λ ( nm ) , surface roughness Ra ( nm ) and primary average particle diameter D ( nm ) of the perovskite-type abrasive particles output from the exposure means, the following formula D + 2 × Ra ≦ λ / 2
Satisfying the above, it is possible to obtain good dot reproduction even in exposure with a short wavelength laser.

  Further, when the external addition amount is 0.05 to 5% by weight, a better image with no image flow can be obtained, and there is no influence on the image due to the contamination of the charging device.

In this reference example, strontium titanate was used as the abrasive particles, but the same effect can be obtained with barium titanate and calcium titanate.

In this reference example, a-SiN was used as the photoreceptor surface layer, but a similar effect can be obtained with a-C, a-SiC, or MgF.

1 is a schematic cross-sectional view showing an image forming apparatus according to the present invention. It is a schematic sectional drawing of the cleaning apparatus concerning this invention. 1 is a cross-sectional view of an electrophotographic photosensitive member according to the present invention. It is sectional drawing which shows an a-Si photoreceptor film-forming apparatus. It is a cross-sectional view of an a-Si photosensitive member deposited film forming apparatus. It is an enlarged photograph of the abrasive particle concerning this invention by an electron microscope. It is a schematic diagram which shows the state of the abrasive particle which exists in the photoreceptor surface. It is a schematic explanatory drawing of the apparatus used for the measurement of triboelectric charge.

Explanation of symbols

101, photoconductor 102, charging roller 103, exposure device 104, developing device 105, transfer member 106, fixing device 107, cleaning device 111, transfer medium 701, photoconductor surface 702, abrasive particles

Claims (1)

The surface of a photoreceptor having a Vickers hardness (JIS standard) of 500 kg / m ² or more was charged by corona charging to form an electrostatic latent image on the photoreceptor, and the electrostatic latent image was developed with toner and developed. In an image forming method for transferring a toner image to a transfer material,
The image forming method includes a cleaning step of removing residual transfer toner remaining on the photoconductor with a cleaning blade, and supplying inorganic fine powder to the photoconductor by a roller member after the transfer and before the cleaning step. And
The photoconductor is an amorphous silicon photoconductor having a photoconductive layer made of a non-single-crystal material based on silicon atoms, and is measured in the range of 10 μm × 10 μm by an atomic force microscope (Q-scope 250). The average inclination Δa of the photoreceptor is 0.1 to 0.9,
The inorganic fine powder is strontium titanate whose primary particles are perovskite type crystals having a cubic particle shape and / or a rectangular parallelepiped particle shape, and the inorganic fine powder has an average primary particle size of 30 nm to 300 nm. And the content of aggregates having a particle size of 600 nm or more is 1% by number or less,
Assuming that the primary average particle diameter of the inorganic fine powder is D (nm), the relationship between the surface roughness Ra (nm) and the average inclination Δa in the range of 10 μm × 10 μm of the photoreceptor is expressed by the following formula 1 <D / 2Ra
D <4 × (Ra / Δa)
An image forming method characterized by satisfying

Images