JP2007086227A - Image forming method and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming method for obtaining a high quality and stable image for a long period with respect to an image forming apparatus/equipment applying an electrophotographic method, and an image forming apparatus which realizes miniaturization, resource saving, and environmental load reduction without impairing the enhancement of reliability and image quality. <P>SOLUTION: In the image forming method including an electrostatic charging process, a latent image forming process, a developing process, a transfer process, and a cleaning process; the toner contains particles of 60 to 300 nm in number average grain size subjected to surface treatment with a silicone oil as an external additive; the average circularity ranges from 0.975 to 1,000; a cleaning member consists of a toner holding function part and an elastic body supporting the toner holding function part and pressing the same to an electrostatic latent image carrier and brings the toner holding function part into contact with the electrostatic latent image carrier at a surface having a nip width below 25% of the outer peripheral surface length of the electrostatic latent image carrier of ≥1 mm in the length in the moving direction of the electrostatic latent image carrier. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming method and an image forming apparatus for developing an electrostatic latent image formed by electrophotography or electrostatic recording with a developer. More specifically, the present invention relates to an image forming method and an image forming apparatus used for a printer, a copier, a fax machine, and the like that output an image to a recording medium.

  In electrophotography, an electrostatic latent image formed on an electrostatic latent image carrier (photoconductor) is developed with toner containing a colorant, and the obtained toner image is transferred onto a recording medium. An image is obtained by fixing with a heat roll or the like. On the other hand, in order to form an electrostatic latent image again on the photoconductor, the residual toner on the surface is removed / cleaned by a cleaning device equipped with a cleaning blade or the like.

  To meet the recent demands for higher image quality and low environmental impact in the electrophotographic market, toner tends to be reduced in diameter and sphere, but it is extremely difficult to remove the small diameter and spherical toner remaining on the photoreceptor. It is difficult to. For example, in a cleaning method using a cleaning blade, there is a problem that such a small particle size or spherical toner rotates between the photosensitive member and the blade, enters the gap and slips through, and is difficult to remove.

  These residual toners that could not be removed may contaminate the charger during the charging process of the electrostatic latent image carrier, or may cause the color to get mixed into other color developing units during the development process. When the transfer process is reached again, it may be transferred onto the transfer body and cause image noise.

  In order to suppress image noise due to toner slipping, there is known a method of increasing the pressure for pressing a cleaning member such as a blade or a brush that scrapes off toner remaining after transfer to an electrostatic latent image carrier. However, this method initially has a high effect of removing the transfer residual toner, but the cleaning member is easily worn, the electrostatic latent image carrier is easily damaged, and the film is reduced. It was difficult.

  Further, problems specific to the image forming method by electrophotography include image flow and image blur due to deterioration of the electrostatic latent image carrier. This is a problem caused by a discharge product generated in the process of charging the surface of the electrostatic latent image carrier. In the process of charging the surface of the latent electrostatic image bearing member, various chargers such as a charging brush, a charging roller, and a non-contact charging device such as a corotron wire are used depending on the purpose. The charger also applies a direct current, an alternating current, or a direct current and an alternating current to a high voltage to uniformly charge the electrostatic latent image carrier. At the same time, the charger chemically changes oxygen and nitrogen in the air to generate discharge products such as ozone and nitrogen oxides.

  These discharge products are highly reactive and hygroscopic. When the discharge products adhere to the electrostatic latent image carrier, the surface characteristics of the electrostatic latent image carrier are altered and the amount of moisture adsorbed increases. Or the surface electrical resistance decreases or the friction coefficient increases. The electrostatic latent image carrier to which the discharge product is attached is liable to leak electric charge, and the formed electrostatic latent image cannot be held. Further, in this state, an image output through the electrophotographic image forming process has troubles such as image flow and image blurring, resulting in a significant deterioration in image quality.

  This image quality defect is caused by the use in a high humidity environment or after the use of the image forming apparatus has been suspended, specifically, after the use in summer, the image forming apparatus is stopped, and the image forming apparatus is started again the next day. This is particularly noticeable in the initial output image when the image is taken. Furthermore, since the surface friction coefficient of the electrostatic latent image carrier has increased even if these image defects do not occur, excessive frictional force is generated at the contact portion with the cleaning member, and heat generation of the drive motor, blades, etc. It causes squealing, turning over, and scratches on the electrostatic latent image carrier.

In order to solve these problems, it is effective to remove moisture and discharge products adhering to the electrostatic latent image carrier and to remove the outermost surface layer of the electrostatic latent image carrier. Many methods have been proposed.
For example, a method of removing the discharge product by wiping the surface of the electrostatic latent image carrier or contacting a member containing a cleaning liquid, and supplying an abrasive component onto the electrostatic latent image carrier. A method of polishing and removing the outermost surface layer of the body, a method of rubbing a cleaning film in which a photocatalyst for decomposing a discharge product is dispersed, and an electrostatic latent image carrier, a surface layer in which inorganic particles are dispersed, and a diamond-like carbon film And a method of rubbing the electrostatic latent image bearing member having the above with a member mainly composed of a nonwoven fabric of ultrafine fibers (for example, see Patent Documents 1 to 5).

  Each of these methods has a certain effect, but it is not sufficient in terms of secondary obstacles and effects. For example, in the method of cleaning the surface of the electrostatic latent image carrier with water or a cleaning liquid, highly reactive substances such as ozone generated by discharge gradually react with the electrostatic latent image carrier itself, and electrostatic The surface layer of the latent image carrier is altered to a state where it can easily bind to moisture. Since the surface layer of the electrostatic latent image carrier that has been altered cannot be removed by washing, it is difficult to prevent image flow and image bleeding. In addition, since a mechanism for storing water and cleaning liquid, a mechanism for cleaning the surface of the electrostatic latent image carrier, and a mechanism for drying the cleaned electrostatic latent image carrier are required, an increase in complexity and size of the apparatus is inevitable. .

  In the method of supplying an abrasive onto the electrostatic latent image carrier, it is difficult to uniformly grind the electrostatic latent image carrier, and scratches caused by excessive polishing and the deterioration of the cleaning member are quick and stable. It is difficult to exert the effect, and the electrostatic latent image carrier having a reduced film thickness changes the electrical characteristics, so that the image density and the gradation of the image are disturbed. In addition, when the abrasive remains in the output image, there is a problem that the image quality is deteriorated such as white spots, color blur, and dullness.

  In addition, the method of sliding the cleaning film using the photocatalyst on the electrostatic latent image carrier can be expected to have a long-term effect on decomposition of the discharge matter, but is effective for removing the surface degradation layer of the electrostatic latent image carrier. It is thin, uses a photocatalytic reaction, requires a certain amount of time for the decomposition reaction, and it is difficult to respond at high speed. If discharge products are generated at a rate higher than the decomposition reaction rate, decomposition removal cannot catch up and discharge products accumulate. Such as the necessity of a light source for photocatalytic reaction.

  Further, the method of rubbing the electrostatic latent image carrier with a member mainly composed of a nonwoven fabric of ultrafine fibers initially has a scraping force of discharge products adhering to the electrostatic latent image carrier due to the ultrafine fibers. Since it can be expected, there is a certain effect in improving image flow and image bleeding, but if the nonwoven fabric fiber is contaminated with the scraped discharge products, the effect of removing discharge dye organisms from the electrostatic latent image carrier is reduced. In order to adjust the scraping force, there is a problem that the nonwoven fabric fibers may damage the electrostatic latent image carrier when the pressure of pressing the member mainly composed of the nonwoven fabric against the electrostatic latent image carrier is increased. Yes.

  As another method for cleaning the electrostatic latent image carrier, the electrostatic latent image carrier may be made of paper dust removing means such as nonwoven fabric in a weak contact state that does not disturb the toner image formed on the electrostatic latent image carrier. There is also a method of installing in (see, for example, Patent Document 6). In this method, the load on the electrostatic latent image carrier is small, and there is little concern about the occurrence of problems such as scratches and wear, and it can be expected to remove dirt that is weakly adhered to the electrostatic latent image carrier such as paper dust. What is firmly attached to the electrostatic latent image carrier such as a discharge product cannot be removed. Further, since there is no function of removing the surface degradation layer of the electrostatic latent image carrier, image flow and image blur are not improved.

As described above, the method for efficiently and stably removing the discharge products on the surface of the latent electrostatic image bearing member is not sufficient, and it is possible to cope with cleaning of the spherical toner used for improving the image quality. At present, no cleaning method has yet been found.
Japanese Patent Laid-Open No. 5-150693 Japanese Patent Laid-Open No. 3-189656 Japanese Patent Laid-Open No. 2001-249592 JP-A-8-248820 Japanese Patent Laid-Open No. 2002-258666 JP 2000-267537 A

The object of the present invention is to solve the above-mentioned problems of the prior art.
That is, an object of the present invention is to provide an image forming method for obtaining a high-quality and stable image over a long period of time with respect to an image forming apparatus and apparatus to which electrophotography is applied. Another object of the present invention is to provide an image forming apparatus that realizes downsizing, resource saving, and low environmental load without impairing high reliability and high image quality.

The above-mentioned subject is achieved by the following present invention. That is, the present invention
<1> A charging step of charging the surface of the electrostatic latent image carrier, a latent image forming step of forming an electrostatic latent image on the charged electrostatic latent image carrier, and developing the electrostatic latent image with a developer containing toner. A development step for forming a toner image, a transfer step for transferring the toner image to a recording medium or an intermediate transfer member, and a cleaning step for removing residual toner remaining on the electrostatic latent image carrier after the transfer by a cleaning member. In the image forming method,
The toner contains particles having a number average particle diameter of 60 to 300 nm surface-treated with silicone oil as an external additive, and the average circularity is in the range of 0.975 to 1.000.
The cleaning member includes a toner holding function part that contacts the surface of the electrostatic latent image carrier and an elastic body that supports the toner holding function part and presses the electrostatic latent image carrier, and the toner holding function. Forming method for contacting the surface with a surface having a nip width of 1 mm or more in the moving direction of the electrostatic latent image carrier and 25% or less of the outer peripheral length of the electrostatic latent image carrier It is.

<2> The image forming method according to <1>, wherein a plurality of the cleaning members are provided around the electrostatic latent image carrier.

<3> The image forming method according to <1> or <2>, wherein a peripheral speed of the electrostatic latent image carrier is in a range of 10 to 250 mm / second.

<4> Charging means for charging the surface of the electrostatic latent image carrier, latent image forming means for forming an electrostatic latent image on the charged electrostatic latent image carrier, and developing the electrostatic latent image with a developer containing toner An image including a developing unit that forms a toner image, a transfer unit that transfers the toner image to a recording medium or an intermediate transfer member, and a cleaning unit that removes transfer residual toner remaining on the electrostatic latent image carrier after the transfer by a cleaning member. In the forming device,
The toner contains particles having a number average particle diameter of 60 to 300 nm surface-treated with silicone oil as an external additive, and the average circularity is in the range of 0.975 to 1.000.
The cleaning member includes a toner holding function part that contacts the surface of the electrostatic latent image carrier and an elastic body that supports the toner holding function part and presses the electrostatic latent image carrier, and the toner holding function. Image forming apparatus in which the portion contacts the electrostatic latent image carrier with a surface having a nip width of 1 mm or more in the moving direction of the electrostatic latent image carrier and 25% or less of the outer peripheral length of the electrostatic latent image carrier It is.

  According to the present invention, for an image forming apparatus and apparatus using electrophotography, an image forming method for obtaining a high-quality and stable image over a long period of time, and a small size without impairing high reliability and high image quality. It is possible to provide an image forming apparatus that realizes a reduction in energy consumption, resource saving, and low environmental load.

Hereinafter, the present invention will be described in detail.
<Image forming method>
The image forming method of the present invention comprises a charging step for charging the surface of an electrostatic latent image carrier, a latent image forming step for forming an electrostatic latent image on the charged electrostatic latent image carrier, and the electrostatic latent image as a toner. A developing process for forming a toner image with a developer containing toner, a transfer process for transferring the toner image to a recording medium or an intermediate transfer member, and a transfer residual toner remaining on the electrostatic latent image carrier after the transfer by a cleaning member In the image forming method including the cleaning step, the toner contains particles having a number average particle diameter of 60 to 300 nm surface-treated with silicone oil as an external additive, and an average circularity of 0.975 to 1.000. The cleaning member comprises a toner holding function part that contacts the surface of the electrostatic latent image carrier and an elastic body that supports the toner holding function part and presses against the electrostatic latent image carrier. In addition, the toner holding function unit is attached to the electrostatic latent image carrier on a surface having a nip width of 1 mm or more in the moving direction of the electrostatic latent image carrier and 25% or less of the outer peripheral length of the electrostatic latent image carrier. It is made to contact.

  As described above, an electrostatic latent image by a wiping member such as a nonwoven fabric, which is a cleaning method performed for adhesion of discharge products to a conventional electrostatic latent image carrier and deterioration of the surface layer of the electrostatic latent image carrier. In the rubbing of the carrier, the discharge product adhering to the electrostatic latent image carrier can be scraped only in a small part where the wiping member is in direct contact with the electrostatic latent image carrier. . Wiping members such as non-woven fabric have minute irregularities on the surface depending on the density of the fibers and the direction of the fibers, and the convex portions are pressed against the electrostatic latent image carrier to exhibit a high scraping effect. A portion that is not in contact with the electrostatic latent image carrier, such as a concave portion between them, does not function effectively, so that the amount of discharge products removed is limited.

  In addition, the scraping of a wiping member such as a non-woven fabric scrapes and removes the discharge product with a fiber such as a non-woven fabric. If it is covered with a scraped discharge product, the ability to remove the discharge product adhering to the electrostatic latent image carrier is not only reduced, but the discharge product accumulated in the scraping member such as a nonwoven fabric As a result, the electrostatic latent image carrier was rubbed again.

  For the above, it is also possible to improve the discharge product removal capability of the surface of the electrostatic latent image carrier by increasing the pressing pressure of a wiping member such as a nonwoven fabric on the electrostatic latent image carrier. However, the surface of the electrostatic latent image carrier was easily damaged in the circumferential direction due to the unevenness caused by the fibers contained in the nonwoven fabric. Furthermore, there has been a problem that the wiping member itself is quickly deteriorated due to an increase in the pressing pressure.

  On the other hand, as described above, even in the cleaning method for preventing poor cleaning of the spherical toner, the electrostatic latent image carrier is eventually increased by increasing the pressing pressure of a cleaning member such as a blade or increasing the scraping force. Since it is necessary to apply a high load, the electrostatic latent image carrier is likely to be damaged similarly to the above, and there are problems such as shortening the life of the cleaning member itself.

  As a result of intensive studies by the present inventors on the above problems, a toner holding function unit that is brought into surface contact with the electrostatic latent image carrier by pressing with an elastic body is used to solve image quality defects such as image flow and image blurring. By using the cleaning member, a certain amount of toner or a toner component is held on the contact surface with the electrostatic latent image carrier, and the surface of the electrostatic latent image carrier is rubbed with the held toner. Has been found to be effective in removing the discharge products and the surface deterioration layer adhering to the electrostatic latent image carrier without damaging the surface of the electrostatic latent image carrier. Furthermore, a new transfer residual toner is always supplied to the cleaning member, and a certain amount of new toner and toner components are always held on the contact surface with the electrostatic latent image carrier. The discharge product and the surface degradation layer do not accumulate excessively on the rubbing surface with the body, and the effect of removing the discharge product and the surface degradation layer adhering to the electrostatic latent image carrier stably for a long time is obtained. be able to.

  At the same time, by using an appropriate spherical toner as the toner in this case, a cleaning member having a toner holding function portion that is brought into surface contact with the electrostatic latent image carrier by pressing with an elastic body while achieving high image quality. By using it, it becomes possible to efficiently remove even spherical toner, and the amount of transfer residual toner supplied to the cleaning member can be made appropriate. It has been found that the load applied to the latent image carrier can be minimized and the effect can be obtained stably over a long period of time.

  Further, by controlling the particle size and surface characteristics of the external additive to be processed by the toner, the toner holding property of the toner holding function portion at the contact portion with the electrostatic latent image carrier is improved, and the toner slips through. It has also been found that toner and toner drops can be suppressed.

Hereinafter, the image forming method of the present invention will be described for each step.
The image forming method of the present invention includes a charging process, a latent image forming process, a developing process, a transfer process, and a cleaning process. First, a cleaning process that is a characteristic process of the present invention will be described.

  In the cleaning process of the present invention, the cleaning member includes a toner holding function part that contacts the surface of the electrostatic latent image carrier and an elastic body that supports the toner holding function part and presses the electrostatic latent image carrier. And the toner holding function unit is placed on the surface having a nip width of 1 mm or more in the moving direction of the electrostatic latent image carrier and 25% or less of the outer peripheral length of the electrostatic latent image carrier. Contact with the image carrier.

  The cleaning member used in the present invention has an elastic body inside, a toner holding function portion on the surface in contact with the electrostatic latent image carrier, and an elastic body supporting the toner holding function portion inside. is important. This is because the elastic body alone does not have the ability to hold toner, and the surface of the electrostatic latent image carrier cannot be rubbed with toner. In addition, it is difficult to form an appropriate pressing pressure and pressure distribution only with the toner holding function unit. Further, by having an elastic body inside, the toner holding amount in the depth direction (perpendicular to the moving direction of the electrostatic latent image carrier) is also increased, and the pressing pressure is increased even if the toner accumulates in the depth direction. The toner holding function portion can be uniformly pressed against the electrostatic latent image carrier, and the effect can be stably maintained for a long time.

  The cleaning member used in the present invention has an electrostatic latent image on the surface having a nip width of 1 mm or more in the moving direction of the electrostatic latent image carrier and 25% or less of the outer peripheral length of the electrostatic latent image carrier. It is important that it is in contact with the carrier. If the width between the cleaning member and the contact surface of the electrostatic latent image carrier is too short, the cleaning function cannot be fully exhibited. In particular, it is difficult to perform the cleaning function for a long time, and the frequency of replacement and maintenance is dramatically increased. On the other hand, if the width of the contact surface between the cleaning member and the electrostatic latent image carrier is too long, the frictional resistance of rubbing increases and a load is applied to the power source that drives the electrostatic latent image carrier. The latent image carrier is easily scratched, and frictional heat is generated to fuse the toner.

  The lower limit of the nip width is preferably 2 mm or more, and more preferably 4 mm or more. The upper limit is preferably 12% or less of the outer peripheral length of the electrostatic latent image carrier, and more preferably 10% or less. The nip width is controlled mainly by the shape, area, pressing pressure, biting amount, and pressing angle of the pressing surface of the elastic body that presses the toner holding function unit.

  As the cleaning member in the present invention, any member may be used as long as the cleaning member is brought into contact with the surface having the nip width and has an internal elastic body and a toner holding function portion on the surface. For example, porous structures such as foamed polyurethane foam, polyolefin foam, and sponge with fine pores on the surface, processed products of elastic structures such as soft rubber and silicone rubber with fine irregularities on the surface, cotton and fabric And fabrics using fibers such as felt and non-woven fabrics, paper products using pulp and the like, and combinations thereof and those combined with elastic bodies such as springs.

  The toner holding function part may adopt any form as long as it has a function of supplementing the toner. However, the toner holding function part may be a fibrous material (cloth, non-woven fabric, brush, etc.) and / or porous. It is preferably a solid body. By using these, for example, a method of capturing toner between fibers using fiber entanglement, a method of creating a minute groove on the surface and storing the toner in the groove, and forming a large number of fine pores on the surface A method of trapping toner inside the hole, a method of forming a surface with a substance that easily generates static electricity and electrically adsorbing the toner, a method of applying voltage to electrically adsorb the toner, and a substance having adhesiveness on the surface. For example, a method of capturing toner can be preferably employed. Particularly preferred is a non-woven fabric present on the surface in a state in which fibers that are easily charged with static electricity are entangled.

More specifically, the following is mentioned.
First, examples of the porous body include polyurethane foam, polyolefin foam, rubber sponge, acrylic foam, poron, Nannex, silicone sponge, fluororubber sponge, and polyethylene foam.

  The hardness of these porous bodies is preferably in the range of 5 to 50 degrees in terms of Asker C hardness from the viewpoint of not damaging the surface while taking a wide contact area with the electrostatic latent image carrier. Further, the pore diameter of the porous body is preferably in the range of 10 to 500 μm from the viewpoint of efficiently holding the toner.

  Examples of the fibrous material include natural cellulose fibers, regenerated cellulose fibers such as rayon, nylon fibers, polyester fibers, polyurethane fibers, polyolefin fibers, acrylic fibers, polyamide fibers, polyamideimide fibers, polyetheramide fibers, and polyphenylene sulfide fibers. And woven fibers such as polybenzimidazole fibers and polyvinyl fibers, and non-woven fibers. A fiber formed by mixing conductive powder such as carbon black, metal oxide particles or metal particles, or a conductive polymer may be used as the fiber, and a non-woven fabric having conductivity may be used.

  As a processing method to the nonwoven fabric, any known method such as a wet chemical bond manufacturing method, a wet thermal bond manufacturing method, a spun lace manufacturing method, a dry chemical bond manufacturing method, a dry thermal bond manufacturing method, a dry spun lace manufacturing method, a needle punch manufacturing method, a stitch bond manufacturing method, A spunbond manufacturing method, a melt blow manufacturing method, a flash spinning manufacturing method, a toe weaving manufacturing method, or the like can be used.

The thickness of the fibers used for the fibrous material is in the range of 1 to 15 μm, and the density is in the range of ³⁰ to 300 g / cm ^{3 in} terms of the basis weight, so that the toner can be efficiently held and, as will be described later, It is preferable in that the replacement can be easily performed.

  In the present invention, the thickness of the toner holding function portion in the contact direction with the electrostatic latent image carrier (when pressed against the electrostatic latent image carrier) is preferably in the range of 0.1 to 1.3 mm. The range of 0.2 to 1.0 mm is more preferable. By setting the thickness within this range, it is possible to sufficiently ensure the durability of the toner holding function unit including the replacement of the toner existing on the electrostatic latent image carrier rubbing surface.

  Examples of the elastic body include natural rubber, nitrile rubber, chloroprene rubber, EPT rubber, butyl rubber, urethane rubber, silicone rubber, and fluorine rubber. These may be foams or solids. In the case of a foam, it is particularly preferable to use a foam that forms closed cells.

  The hardness of the elastic body is preferably in the range of 2 to 30 degrees in terms of Asker C hardness. When the toner holding function part is a porous material such as urethane foam, the ratio (A / B) between the hardness A of the toner holding function part and the hardness B of the elastic body is 1.0 to 3.0. This range is preferable from the viewpoint of realizing the strength of the toner holding function unit and a stable contact rubbing state on the electrostatic latent image carrier.

  Furthermore, the thickness of the elastic body in the pressing direction is preferably in the range of 2 to 20 mm. If the thickness is too small, a sufficient elastic effect cannot be obtained, and it becomes difficult to obtain a stable contact rubbing state on the electrostatic latent image carrier, and if it is too thick, rubbing with the electrostatic latent image carrier is difficult. Because the frictional force is dragged in the moving direction of the electrostatic latent image carrier and the posture is disturbed, it is difficult to obtain a stable contact rubbing state on the electrostatic latent image carrier. The pressing direction is preferably a direction perpendicular to the sliding surface of the electrostatic latent image carrier.

Particularly preferable as a cleaning member having the above-described structures is a combination of a foamed elastic body such as polyurethane foam or poron and a non-woven fabric made of polyester fiber or nylon fiber as a toner holding function part, polyester For example, a non-woven fabric made of fibers or nylon fibers may be superimposed.
The toner holding function portion and the elastic body in the present invention may be integrated as long as the above functions can be achieved. As a preferable example of this type, a polyurethane foam having fine irregularities on the surface, Polon etc. are mentioned.

The cleaning member is used by being pressed against the electrostatic latent image carrier with a certain pressure. In this case, the effect can be exhibited more efficiently by selecting an appropriate pressing pressure according to the material type and shape of the electrostatic latent image carrier.
As an example of an appropriate pressing pressure of the cleaning member to the electrostatic latent image carrier, a pressing force is applied to the electrostatic latent image carrier having a cylindrical shape with a diameter of 30 mm and an outermost surface layer made of an organic resin component. the covering preferably in the range of 0.2~1.5gf / cm ² pressure, and more preferably in the range of 0.3~1.2gf / cm ^2.

  The pressing force of the cleaning member to the electrostatic latent image carrier is the amount of biting into the electrostatic latent image carrier, the hardness and elasticity of the elastic part, the hardness and elasticity of the toner holding function part, and the electrostatic latent image carrier. It can be arbitrarily adjusted by controlling the hardness and elasticity of the body.

In the cleaning member installed as described above, when used as an image forming apparatus, the toner contributing to cleaning is 0.005 to 0.08 mg / mm ² between the surface of the photoreceptor and the toner holding function unit. It is preferable to be held in the range of about.

  One cleaning member or a plurality of cleaning members may be installed as required for one electrostatic latent image carrier. Increasing the number of installations improves the ability to remove the discharge products attached to the electrostatic latent image carrier and the ability to remove the deteriorated layer of the electrostatic latent image carrier. The installation location of the cleaning member may be anywhere depending on the layout of the image forming apparatus, but preferably after the step of transferring the toner image formed on the electrostatic latent image carrier to the recording medium or the intermediate transfer member, One example is before the step of uniformly charging the surface of the latent electrostatic image bearing member. At this position, there is no concern about image quality deterioration due to transfer residual toner or charger contamination, and the ability to remove the discharge products attached to the electrostatic latent image carrier and the ability to remove the deteriorated layer of the electrostatic latent image carrier. Can be demonstrated.

  On the other hand, the toner (transfer residual toner) used in the cleaning process contains particles having a number average particle diameter of 60 to 300 nm surface-treated with silicone oil as an external additive and an average circularity of 0.975 to 1. 000 range.

  In the present invention, the toner present on the surface of the cleaning member rubs the surface of the electrostatic latent image carrier to remove discharge products on the electrostatic latent image carrier. Further, since the cleaning member is appropriately covered with the toner, the unevenness of the cleaning member itself is alleviated and the electrostatic latent image carrier is prevented from being damaged.

  It should be noted that what is held by the cleaning member is not limited to the toner, but may be a part of the toner component, or the toner and a part of the toner component may be held together. The term “a part of the toner component” as used herein refers to a lubricity imparting agent mixed with the toner, an abrasive, an external additive released from the toner, and the like. When these substances are also held on the surface of the cleaning member, they perform the same function as toner, so the ability to remove the discharge products adhering to the electrostatic latent image carrier and the effect of removing the deteriorated layer of the electrostatic latent image carrier Can be obtained.

In this case, residual toner is sequentially supplied to the toner holding function portion on the surface of the cleaning member. In addition, the electrostatic discharge image carrier is excessively contaminated without the toner that has adhered a large amount of the removed discharge product and the debris from the electrostatic latent image carrier remaining on the outermost surface of the cleaning member. It is necessary to keep the toner that is not always in contact.
That is, the portion of the cleaning member that is in contact with the electrostatic latent image carrier is always not contaminated by the discharge product or the shavings of the deteriorated layer of the electrostatic latent image carrier, and adheres to the electrostatic latent image carrier. Therefore, it is necessary to maintain a stable effect while maintaining the ability to remove the discharge product and the ability to remove the deteriorated layer of the electrostatic latent image carrier.

  In order to obtain the above effect, first, it is important that the toner used in the present invention has an average circularity in the range of 0.975 to 1.000. By setting the average circularity in the range of 0.975 to 1.000, the amount of transfer residual toner that reaches the cleaning member is appropriately maintained while achieving a high-quality image. The part can always form a stable state.

  The average circularity is preferably in the range of 0.975 to 0.995, and more preferably in the range of 0.977 to 0.987. If the average circularity is too small, not only the reproducibility of the fine line portion and the homogeneity of the halftone portion is impaired, the image quality is impaired, but also the amount of toner remaining after the transfer is increased, and the toner holding function portion on the surface of the cleaning member In other words, the image is not completely held and slips through, causing image quality defects such as color streaks and color mixing.

  The average circularity of the toner is measured by, for example, a flow-type particle shape measuring machine, an image analysis device, or the like, and the circumference of a circle having a maximum toner length (equivalent circumference) and the actual circumference of the toner. From (perimeter length), it is calculated by (circle equivalent perimeter length / perimeter length).

  Further, the toner used in the present invention needs to contain particles having a number average particle diameter in the range of 60 to 300 nm and surface-treated with silicone oil as an external additive. This is because when the surface of the particle as an external additive is treated with silicone oil, the lubricity of the particle is improved and the adhesion is increased, so that the toner to which the particle is externally added reaches the toner holding function portion of the cleaning member. Then, in order to reduce the frictional force with the electrostatic latent image carrier by the action of the silicone oil on the particles, the toner holding function unit can reliably hold the toner from the pressure contact portion between the cleaning member and the electrostatic latent image carrier. There is no slipping through.

  In addition, the binding force of silicone oil can efficiently capture the discharge products adhering to the electrostatic latent image carrier and the surface degradation layer shavings of the electrostatic latent image carrier. There is no transfer to the electrostatic latent image carrier. In addition, since the adhesion to the toner holding function part is strengthened by the action of particle adhesion, and the frictional friction force with the electrostatic latent image carrier is weakened by the slipperiness of the particles, The toner and toner components are prevented from being detached, and the toner and toner components on the surface of the toner holding function unit are pushed into the toner holding function unit by new transfer residual toner and toner components supplied to the rubbing unit later, Since the toner moves to the side away from the electrostatic latent image carrier, the toner at the contact portion with the electrostatic latent image carrier can be efficiently replaced.

  In addition, when the number average particle diameter of the particles treated with the silicone oil is in the range of 60 to 300 nm, it can be appropriately present on the surface of the toner and exhibit an effect. A preferred number average particle size range is in the range of 80 to 200 nm, more preferably in the range of 90 to 180 nm.

  When the particle size of the particles treated with silicone oil is smaller than 60 nm, the effect is reduced because the particles are not sufficiently exposed to the toner surface and are hidden by the unevenness present on the toner particle surface. Further, since the toner is easily embedded in the toner when subjected to stress, the maintainability of the effect also decreases. If the particle size is larger than 300 nm, the toner particles are not fixed on the surface of the toner particles and are detached from the toner, so that the expected effect cannot be obtained, and the particles adhere to the electrostatic latent image carrier or the charger. It may cause image quality defects or scratch the electrostatic latent image carrier or charger.

Specific examples of the particles having a number average particle diameter of 60 to 300 nm and surface-treated with silicone oil used in the present invention include the following.
First, the core particles as the core are silica, titania, alumina, zinc oxide, cerium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, calcium carbonate, silica sand, clay, mica, wollastonite , Diatomaceous earth, cerium chloride, bengara, chromium oxide, antimony trioxide, magnesium oxide, zirconium oxide, silicon carbide, silicon nitride calcium carbonate, etc .; acrylic resin particles, urea resin particles, melamine resin particles, nylon resin And various resin particles such as particles, fluororesin particles, silicone resin particles, fatty acid metal salts, higher alcohols and waxes; and inorganic particles such as carbon black.

  As said silicone oil, what is represented by following General formula (1) is preferable.

  In the general formula (1), R represents an alkyl group having 1 to 3 carbon atoms, R ′ includes a halogen group, a halogen-modified alkyl group, a phenyl group, a modified phenyl group, a substituted or unsubstituted sulfonic acid group, and a hetero atom. Any of the organic groups that may be present, R ″ represents an alkyl group having 1 to 3 carbon atoms or an alkoxy group. N and m each represent an integer of 1 or more.

  Specifically, dimethyl silicone oil, methyl hydrogen silicone oil, methyl phenyl silicone oil, alkyl modified silicone oil, α-methyl sulfone modified silicone oil, chlorophenyl silicone oil, amino modified silicone oil, epoxy modified silicone oil, carboxyl modified Examples include silicone oil, carbino-modified silicone oil, methacryl-modified silicone oil, mercapto-modified silicone oil, phenol-modified silicone oil, polyether-modified silicone oil, methylstyryl-modified silicone oil, higher fatty acid ester-modified silicone oil, and fluorine-modified silicone oil. However, the silicone oil in the present invention is not limited to these compounds.

  Examples of the combination of the mother particles and silicone oil include silica, titania, alumina treated with dimethyl silicone oil, and silica, titania, alumina treated with a silane coupling treatment agent, and further treated with dimethyl silicone oil.

  As a method for surface-treating the mother particles with silicone oil, a known method can be used, for example, spray drying in which silicone oil or a solution containing silicone oil is sprayed on the mother particles suspended in the gas phase. It can be processed by a dry method such as a method or a wet method in which particles are immersed in a solution containing a treatment agent and dried. As long as the silicone oil treatment is performed, a composite treatment or a multilayer treatment using a known coupling agent may be performed.

  The treatment amount of the silicone oil may be arbitrarily selected, but a preferable range is preferably a range of 0.5 to 35 parts by mass, more preferably a range of 1 to 15 parts by mass with respect to 100 parts by mass of the base particles. Is mentioned. If the amount of silicone oil to be treated is too small, the efficiency of capturing toner on the surface of the cleaning member may be reduced. When the amount of the silicone oil to be treated is too large, problems such as excessive silicone oil deteriorating the powder characteristics of the toner and the silicone oil being liberated and contaminating the member are likely to occur.

  The surface-treated particles can be added in an arbitrary amount to the toner particles, but a preferable range is 0.3 to 5 parts by mass, more preferably 0.5 to 100 parts by mass of the toner particles. The range of -3 mass parts is mentioned. If the amount added is too small, the efficiency of capturing the toner on the surface of the cleaning member may be reduced. If the amount to be added is too large, excessive particles may be released and agglomerate or adhere, which may cause various problems. For example, if particle agglomerates are mixed in the image, it may cause image quality defects such as white spots, or if loose particles adhere to the developing device, the developer transport becomes unstable, resulting in uneven density or streaks. It may cause image quality defects such as missing shapes.

  Furthermore, if necessary, a plurality of kinds of particles not subjected to the known silicone oil treatment, such as the aforementioned metal oxide particles, resin particles, and inorganic particles, can be added.

Next, other steps of the image forming method of the present invention will be described.
The charging step is a step of uniformly charging the electrostatic latent image carrier. Examples of the charging means include a non-contact charger such as corotron and scorotron, and a contact method in which a latent image carrier surface is charged by applying a voltage to a conductive member in contact with the latent image carrier surface. Any type of charger may be used. However, a contact charging type charger is preferable from the viewpoint that the amount of generated ozone is small, there are few problems of environmental pollution and off-flavor, and power consumption is low. In the contact charging type charger, the shape of the conductive member may be any of a brush shape, a blade shape, a roller shape, etc., but the viewpoint that the charging stability is high and the wear of the electrostatic latent image carrier can be suppressed. A roller-like member is preferable.

  The latent image forming step is a step of forming an electrostatic latent image by exposing the surface of the electrostatic latent image carrier charged in the charging step with a laser optical system or an LED array. The image forming method of the present invention is not subject to any particular limitation in the latent image forming process.

  The developing step refers to the electrostatic latent image on the surface of the latent image carrier by bringing the developer carrier on which the developer layer containing at least toner is formed on the surface of the latent image carrier. In this step, toner particles are adhered to the surface of the latent image carrier to form a toner image. The development method can be performed using a known method. Examples of the development method using the two-component developer used in the present invention include a cascade method and a magnetic brush method. , Contact magnetic brush method, non-contact non-shoot method, etc. The image forming method of the present invention is not particularly limited with respect to the developing method.

  The transfer step is a step of transferring a toner image formed on the surface of the electrostatic latent image carrier to a recording medium to form a transfer image. The transfer step in the present invention includes not only the transfer of the toner image directly onto a recording medium such as paper but also the transfer onto an intermediate transfer member.

A corotron can be used as a transfer device that transfers a toner image from the electrostatic latent image carrier onto paper or the like. Corotron is effective as a means to electrostatically move toner and transfer toner images to paper or an intermediate transfer body, but a high voltage of several kV is applied to give a predetermined charge to paper as a recording medium. And requires a high voltage power supply. In addition, ozone is generated by corona discharge, which causes deterioration of rubber parts and the electrostatic latent image carrier. Therefore, a conductive transfer roll made of an elastic material is pressed against the electrostatic latent image carrier and the intermediate transfer member. In addition, a contact transfer method in which a toner image is transferred to paper or an intermediate transfer member is preferable.
In the image forming method of the present invention, the transfer device is not particularly limited.

The image forming method of the present invention may also include a fixing step.
The fixing step is a step of fixing the toner image transferred on the surface of the recording medium with a fixing device. As the fixing device, a heat fixing device using a heat roll is preferably used. The heat fixing device includes a fixing roller having a heater lamp for heating inside a cylindrical metal core, a so-called release layer formed on the outer peripheral surface by a heat resistant resin film layer or a heat resistant rubber film layer, and the fixing roller. The pressure roller or pressure belt is disposed in pressure contact with the roller and has a heat-resistant elastic body layer formed on the outer peripheral surface of the cylindrical metal core or the surface of the belt-like base material. The fixing process of the unfixed toner image is performed by inserting a recording material on which an unfixed toner image is formed between a fixing roller and a pressure roller or a pressure belt, and using a binder resin, an additive, and the like in the toner. Fix by heat melting.
In the image forming method of the present invention, the fixing method is not particularly limited.

  In the image forming method of the present invention as described above, the peripheral speed (moving speed) of the electrostatic latent image carrier used is preferably in the range of 10 to 240 mm / second, and in the range of 30 to 220 mm / second. It is more preferable. If the peripheral speed of the electrostatic latent image carrier is too low, the image forming speed is extremely reduced, which is difficult in terms of productivity, and the electrostatic latent image on the electrostatic latent image carrier is developed using a developer. Thus, when forming a toner image, there is a problem that charges are injected into the developer to disturb the toner image. If the peripheral speed of the latent electrostatic image bearing member is too high, the frictional friction between the latent electrostatic image bearing member and the cleaning member becomes too large, and heat is generated at the contact portion, causing deterioration of the member and toner fusing, or residual transfer. The toner can easily pass through the cleaning member, or the toner image formed on the electrostatic latent image carrier can be easily disturbed.

Here, the toner used in the present invention will be described in more detail.
As the toner used in the present invention, the following spherical toner is particularly suitable. In recent years, there have been increasing demands for higher quality output images, lower power consumption of image forming devices, and environmental load improvements in the toner manufacturing process. To meet these demands, technology to reduce toner particle size and shape control technology of toner has been developed. Have been doing. Toners using a wet manufacturing method meet these requirements, development of wet toner manufacturing technology and commercialization of wet manufacturing toners are rapidly progressing.

  In general, a wet process toner can reduce the particle size of the toner, improve the particle size distribution, and control the shape, so that a toner suitable for the purpose can be obtained, and is particularly suitable for high image quality. That is, since toner with a small particle size can be developed faithfully to the electrostatic latent image, even fine images such as fine lines can be reproduced with high quality. A toner having a nearly spherical shape, such as a spherical toner or a potato-shaped toner, has stable developability and transferability for a long period of time, so that a high-quality image can be obtained with little highlighting. When a full-color image is formed, a secondary color highlight image with little color shift or harshness can be stably reproduced. Furthermore, since the internal structure of the toner can be controlled, it is possible to save power in the image forming apparatus such as high-speed fixing and low-temperature fixing by optimizing the dispersion form of the release agent and the viscoelasticity of the toner. . Furthermore, the toner wet manufacturing method can eliminate the fine pulverization process and the classification process that require a large amount of energy in the conventional kneading pulverized toner manufacturing process, thereby reducing the energy required for toner manufacturing and improving the yield. It is highly effective for low environmental impact. Since it is possible to reduce the amount of residual toner in the transfer process in the electrophotographic method, it is possible to reduce the amount of waste toner and to effectively use the toner.

  Examples of the wet manufacturing method of the spherical toner include an emulsion polymerization method, an emulsion polymerization aggregation method, a suspension polymerization method, and a melt suspension method. In addition, the amorphous toner obtained by the conventionally used melt-kneading pulverization method can be made spherical by hot air treatment or the like.

  The toner used in the present invention contains, in addition to a binder and a colorant such as carbon black, a release agent such as wax, and one or more inorganic powders or resin powders that adjust viscoelasticity as an internal additive. It may be configured. In addition, a petroleum resin may be included in order to satisfy the pulverization property and heat storage property of the toner. Petroleum-based resins are synthesized from diolefins and monoolefins contained in cracked oil fractions by-produced from an ethylene plant that produces ethylene, propylene and the like by steam cracking of petroleum.

  Binders used in toners include styrenes such as styrene and chlorostyrene; monoolefins such as ethylene, propylene, butylene, and isoprene; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, and vinyl acetate. Α-methylene aliphatic monocarboxylic acids such as methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate Examples of homopolymers or copolymers of esters; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl butyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropenyl ketone; Rukoto can.

  Particularly representative binder resins include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer. A polymer, polyethylene, and polypropylene can be mentioned. Furthermore, polyesters, polyurethanes, epoxy resins, silicone resins, polyamides, and modified rosins can be exemplified, but the invention is not particularly limited thereto.

  What is suitable as a mold release agent used for this invention is obtained from the following waxes. Paraffin wax and derivatives thereof, montan wax and derivatives thereof, microcrystalline wax and derivatives thereof, Fischer-Tropsch wax and derivatives thereof, polyolefin wax and derivatives thereof, and the like. Derivatives include oxides, polymers with vinyl monomers, and graft modified products. In addition, alcohols, fatty acids, plant waxes, animal waxes, mineral waxes, ester waxes, acid amides and the like can be used, but are not particularly limited thereto.

  In addition, the toner particle colorants include carbon black, nigrosine, aniline blue, calcoil blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, lamp black, Rose Bengal, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 57: 1, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 12, C.I. I. Pigment blue 15: 1, C.I. I. Pigment Blue 15: 3 can be exemplified as a representative one.

  The toner used in the present invention may be produced by any known method, and examples thereof include known production methods such as kneading and pulverization method, suspension polymerization method, emulsion polymerization aggregation method, submerged drying method and dispersion polymerization method. However, the present invention is not limited to this. As a method for producing a small particle toner, a spherical toner, or a potato toner, an emulsion polymerization aggregation method is particularly preferable.

  In addition to the particles in the present invention, the toner particles obtained by the above-described method may contain inorganic powder and resin powder alone for the purpose of further improving the long-term storage stability, fluidity, developability and transferability of the toner. Or you may add together. As the inorganic powder, for example, known inorganic compounds such as silica, alumina, titania, zinc oxide and the like can be used without particular limitation, and these may be used alone or in combination of two or more. it can.

  Specific silica particles may contain anhydrous silicate, aluminum silicate, sodium silicate, potassium silicate, etc., but the composition has a refractive index of 1.5 or less. Are preferred. Further, it may be subjected to surface treatment using various methods. For example, those surface-treated with a silane coupling agent, a titanium coupling agent, silicone oil, etc. can be preferably used.

Examples of the resin powder include spherical particles such as PMMA, nylon, melamine, benzoguanamine, and fluorine, and amorphous powders such as vinylidene chloride and fatty acid metal salts.
When these particles are added to the surface of the toner particles, the amount of each added should be in the range of 0.1 to 5% by mass, more preferably 0.5 to 3% by mass. Is preferred. The toner used in the present invention can be produced by mixing toner particles and the above external additive using a Henschel mixer or a V blender. In addition, when the toner particles are produced by a wet method, external addition can be performed by a wet method.

  The volume average particle size of the toner used in the present invention is preferably in the range of 3 to 9 μm, and more preferably in the range of 4 to 8 μm. When the volume average particle diameter of the toner particles exceeds 9 μm, the ratio of coarse particles increases, and the reproducibility and gradation of fine lines and fine dots of the image obtained through the fixing process are lowered. On the other hand, when the volume average particle size of the toner particles is less than 3 μm, the powder fluidity, developability, or transferability of the toner deteriorates, and the cleaning property of the toner remaining on the surface of the image carrier decreases. Various problems occur in other processes due to the deterioration of characteristics.

  Further, as the particle size distribution index of the toner particles used in the present invention, the volume average particle size distribution index GSDv is preferably 1.30 or less, and the ratio GSDv / GSDp to the number average particle size distribution index GSDp is 0.95 or more. It is more preferable that When the volume distribution index GSDv exceeds 1.30, the homogeneity of the highlight portion decreases, and when the ratio of the volume average particle size distribution index GSDv to the number average particle size distribution index GSDp is less than 0.95, the chargeability decreases. At the same time it may occur, it may scatter and cause image defects such as fogging.

The volume average particle size and the particle size distribution index were measured and calculated as follows. First, with respect to the divided particle size range (channel) measured using Coulter Multisizer II (manufactured by Beckman-Coulter) as a measuring device, the volume and number of individual toner particles from the small diameter side. Draw a cumulative distribution, define the particle size to be 16% cumulative as volume average particle size D16v and number average particle size D16p, and set the particle size to 50% cumulative to volume average particle size D50v (this value is the volume average particle size). Defined as D50p). Similarly, the particle diameters with an accumulation of 84% are defined as volume average particle diameters D84v and D84p. Using these, the volume average particle size distribution index GSDv is defined as (D84v / D16v) ^1/2 , and the number average particle size distribution index GSDp is defined as (D84p / D16p) ^1/2 .

Further, the toner shape factor SF1 in the present invention is preferably in the range of 110 to 140.
By setting the shape factor SF1 in the range of 110 to 140, the transfer efficiency of the toner image after development can be increased, and the supply amount of the transfer residual toner to the cleaning member can be made constant.

Here, the shape factor SF1 is obtained by the following equation (1).
SF1 = (ML ² / A) × (π / 4) × 100 (1)
In the above formula (1), ML represents the absolute maximum length of the toner particles, and A represents the projected area of the toner particles.

In the present invention, the toner is used not only in a one-component developer but also in a system called a two-component developer composed of a toner and a carrier.
The carrier may be any known carrier, iron powder, ferrite, glass beads, resin particles in which fine magnetic powder is dispersed, magnetic powder having a resin coated on the surface, and the like. More preferably, a carrier in which a magnetic powder core is coated with a resin is selected for charge control and electric resistance control.

  As the coating resin of the resin-coated carrier, a resin that suppresses contamination of the coating film surface due to toner constituents and adhesion of the toner itself, and has excellent mechanical strength and resistance to abrasion and breakage is preferable. Specifically, polyolefin resin, polyvinyl resin and polyvinylidene resin are preferable, and more specifically, acrylic resin, polystyrene resin, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, Polyvinyl ether, polyvinyl ketone, polyester, polyurethane, polycarbonate, amino resin, epoxy resin, vinyl chloride-vinyl acetate copolymer, styrene-acrylic copolymer, silicone resin composed of organosiloxane bond, and modified products thereof, fluorine resin , Polystyrene resin, methacrylic acid and the like. Particularly preferred are polystyrene resin, acrylic acid resin, and styrene acrylic copolymer.

  As a coating amount, Preferably it is the range of 0.5-5 mass%, More preferably, the range of 1.5-3.5 mass% is mentioned. If the amount is too small, the carrier core material is often exposed, and the characteristics as a coat carrier are not exhibited. If the amount is too large, adhesion to the manufacturing equipment during carrier production and generation of agglomerates where the carriers are united with each other will increase, resulting in a decrease in manufacturability but also a decrease in fluidity of the carrier powder and mixing with toner. There is a concern that the toner tends to become a non-uniform developer.

Various additives can be applied to the coating layer for the purpose of charge control and electric resistance control.
For charge control, charge control agents such as nigrosine dyes, benzimidazole compounds, quaternary ammonium salt compounds, alkoxylated amines, alkylamides, molybdate chelate pigments, triphenylmethane compounds, salicylic acid metal salt complexes, Any known azo chromium complex, copper phthalocyanine, etc. may be used. Particularly preferred are quaternary ammonium salt compounds, alkoxylated amines and alkylamides.

  For electrical resistance control, known conductive powder, metal particles, metal oxide particles, carbon black, carbon fiber, metal compound particles, and the like can be arbitrarily selected. Of these, carbon black is particularly preferable. A preferable addition amount is in the range of 0.05 to 20 parts by mass when the carrier core material is 100 parts by mass. If it is in this range, the control of electric resistance and the strength of the carrier coat film can be compatible, which is preferable. A more preferred range is from 0.1 to 5 parts by mass.

  Further, the carrier further includes known particles such as acrylic resin particles, urea resin particles, melamine resin particles, nylon resin particles, fluororesin particles, silicone resin particles, silica particles, titania particles, alumina particles, and the like. The metal oxide particles can be optionally added. The particles may be subjected to a surface treatment as necessary. By adding these particles, the dispersion state of the additive in the coating film can be controlled, and the charging characteristics and electrical resistance characteristics of the carrier can be improved.

  The manufacturing apparatus used for manufacturing the carrier may be of any known type. Examples include a fluidized bed, spray drying, a high-speed rotary mixer, a planetary coating apparatus, a kneader coating apparatus, and the like. A particularly preferable manufacturing apparatus is a kneader coating apparatus.

  The mixing ratio (mass ratio) of the toner and the carrier is in the range of toner: carrier = 1: 100 to 30: 100, and more preferably in the range of 3: 100 to 20: 100.

<Image forming apparatus>
Next, the image forming apparatus of the present invention will be described.
An image forming apparatus according to the present invention includes a charging unit that charges an electrostatic latent image carrier by applying a voltage from the outside, a latent image forming unit that forms an electrostatic latent image, and the electrostatic latent image that has toner. Developing means for developing the toner image into a toner image using the developer, transfer means for transferring the toner image to a recording medium or an intermediate transfer member, and transfer residual toner remaining on the electrostatic latent image carrier after transfer. An image forming apparatus including a cleaning unit that removes the toner using a cleaning member, wherein the above-described cleaning member and toner are used.

  FIG. 1 is a schematic cross-sectional view showing an electrophotographic apparatus which is an example of the image forming apparatus of the present invention. The electrophotographic apparatus shown in FIG. 1 includes an electrophotographic photosensitive member (electrostatic latent image carrier) 10, a charger (charging means) 11 that charges the surface of the electrophotographic photosensitive member 10, and a voltage applied to the charger 11. A power source 12, an image input device (latent image forming means) 13 for forming a latent image on the surface of the electrophotographic photosensitive member 10, and an electrostatic latent image developer formed on the surface of the electrophotographic photosensitive member 10. A developing unit (developing unit) 14 that develops the electrostatic latent image to obtain a toner image, a transfer unit (transfer unit) 15 that transfers the formed toner image to the surface of the recording medium 20, and a toner on the surface of the elastic body A cleaning device (cleaning means) 16 that removes residual toner and the like on the surface of the electrophotographic photosensitive member 10 by a cleaning member 19 having a holding function unit, a static eliminator 17 that removes a residual potential on the surface of the electrophotographic photosensitive member 10, Transferred to the surface of the recording medium 20 The toner image includes a fixing device 18 for fixing by heat and / or pressure, etc., the.

The electrophotographic photosensitive member 10 in FIG. 1 is provided with a contact charging type charger 11 such as a charging roll, and the charger 11 is operated by a voltage supplied from a power source 12. In this example, the transfer device 15 uses a contact transfer method such as a transfer roll, but in the present invention, the contact transfer method or the non-contact transfer method is not limited.
The cleaning device 16 is configured with the cleaning member 19 provided in the opening of the box 21, and among the residual toner removed from the surface of the electrophotographic photosensitive member 10, the toner that could not be held in the toner holding function portion, etc. The structure is accommodated in the box 21.

  In addition, the configurations of the image input device (latent image forming unit) 13, the developing unit (developing unit) 14, the transfer unit (transfer unit) 15, the static eliminator 17, and the fixing unit 18 are not particularly limited in the present invention. Any configuration conventionally known in the electrophotographic field can be applied as it is. In the case of the configuration using the contact charging type charger 11 as in this example, the static eliminator 17 is not necessarily provided.

  In the image forming apparatus, by using the developer and cleaning member of the present invention described above as the electrostatic latent image developer and cleaning member, various properties such as charging property, developing property, transfer property, fixing property, and cleaning property can be obtained. The properties can be maintained over a long period of time. Further, since cleaning is performed with a spherical or potato-shaped toner or toner component held in the toner holding function unit, even in long-term use, without causing damage to the electrostatic latent image carrier, which causes functional deterioration, It is possible to remove the discharge product adhering to the electrostatic latent image carrier and the deteriorated layer on the surface of the electrostatic latent image carrier, and further, high quality images can be obtained without contaminating the charging member and the transfer member. It can be formed stably.

  Hereinafter, although an example and a comparative example are given and the present invention is explained more concretely in detail, the present invention is not limited to the following examples. In the following description, “part” represents “part by mass” and “%” represents “% by mass” unless otherwise specified.

<Measuring method of various characteristics>
First, methods for measuring physical properties of toners and the like used in Examples and Comparative Examples will be described.
(Measurement method of toner particle size)
In the measurement of the toner particle size in the present invention, COULTER MULTISIZER II (manufactured by Beckman-Coulter) was used as a measuring device, and ISOTON-II (manufactured by Beckman-Coulter) was used as the electrolyte.

  As a measurement method, 0.5 to 50 mg of a measurement sample is added to 2 ml of a 5% aqueous solution of a surfactant, preferably sodium alkylbenzenesulfonate, as a dispersant. This was added to 100 to 150 ml of the electrolytic solution. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 minute, and the particle size distribution of particles of 2 to 60 μm is measured using the Coulter counter TA-II with an aperture diameter of 100 μm. The volume average particle diameter, GSDv, and GSDp were determined as described above. The number of particles to be measured was 50,000.

(Measurement of average circularity of toner)
The average circularity of the toner was measured with FPIA-2100 manufactured by Sysmex. This system employs a method in which particles dispersed in water or the like are measured by a flow-type image analysis method, and the aspirated particle suspension is guided to a flat sheath flow cell and converted into a flat sample flow by the sheath liquid. It is formed. By irradiating the sample stream with stroboscopic light, the passing particles are imaged as a still image with a CCD camera through the objective lens, and the captured particle image is processed in a two-dimensional image to obtain a projection area and perimeter length. The equivalent circle diameter and circularity were calculated.

The equivalent circle diameter was calculated as the equivalent circle diameter from the area of the two-dimensional image with respect to each photographed particle. The number average particle size and the number average particle size variation were determined by performing image processing for each of at least 5,000 particles photographed in this manner and performing statistical processing. Regarding the circularity, the circularity was determined by the following equation (2) for each photographed particle. As for the circularity, the average circularity was obtained by performing image analysis on 5,000 or more particles photographed and performing statistical processing.
Circularity = circle equivalent diameter circumference length / perimeter length = [2 × (Aπ) ^1/2 ] / PM Formula (2)
In the above formula, A represents the projected area, and PM represents the perimeter. In addition, HPF mode (high resolution mode) was used for the measurement, and the dilution factor was 1.0. In analyzing the data, the number particle size analysis range was set to 2.0 to 30.1 μm and the circularity analysis range was selected to be 0.40 to 1.00 for the purpose of removing measurement noise.

(Measurement method of particle size)
The number average particle diameter of the particles was confirmed by a scanning electron microscope (manufactured by Hitachi, Ltd .: S-4100). The particles were observed with a scanning electron microscope, the particle diameter of 300 primary particles was measured, and the average value was obtained.

(Measurement method of molecular weight and molecular weight distribution of resin)
In the present invention, the specific molecular weight distribution is performed under the following conditions. GPC uses “HLC-8120GPC, SC-8020 (manufactured by Tosoh Corporation)” apparatus, and column uses “TSKgel, SuperHM-H (6.0 mm ID × 15 cm, manufactured by Tosoh Corporation)”. THF (tetrahydrofuran) was used as an eluent. As experimental conditions, an experiment was performed using a sample concentration of 0.5%, a flow rate of 0.6 ml / min, a sample injection amount of 10 μl, a measurement temperature of 40 ° C., and an IR detector. The calibration curve is “polystylen standard sample TSK standard” manufactured by Tosoh Corporation: “A-500”, “F-1”, “F-10”, “F-80”, “F-380”, “A-2500”. ”,“ F-4 ”,“ F-40 ”,“ F-128 ”, and“ F-700 ”.

(Volume average particle diameter of resin particles, colorant particles, etc.)
Volume average particle diameters of resin particles, colorant particles, and the like were measured with a laser diffraction particle size distribution measuring apparatus (LA-700, manufactured by Horiba, Ltd.).

(Measurement method of glass transition temperature of resin, melting point of release agent)
The glass transition temperature of the resin is the temperature at the intersection of the base line and the rising line in the endothermic part when differential scanning calorimetry is performed according to ASTM D3418-8, and the melting point of the release agent is the endothermic peak. The temperature at the apex of
A differential scanning calorimeter (manufactured by Shimadzu Corporation, DSC-50) was used for the measurement.

(Measurement of cleaning member pressing pressure)
An equipment that can move up and down with the cleaning member fixed horizontally was prepared, and the cleaning member used for the experiment was fixed to this equipment. The photosensitive member (electrostatic latent image carrier) used for the experiment is fixed on the balance, and the cleaning member is gradually lowered and pressed against it, and the strain on the elastic member of the cleaning member and the load applied to the balance at that time And recorded. A value obtained by dividing the load by the area where the cleaning member is in contact with the photosensitive member was defined as the pressing pressure. Note that when the cleaning member was attached to the image forming apparatus with a predetermined pressing pressure, the cleaning member support was adjusted so that the elastic member had the same strain (bite-in amount) in the cleaning member.

<Preparation of particles>
(Particle 1)
Surface treatment is performed by spraying 5 parts of dimethyl silicone oil with a viscosity of 50 cs on 100 parts of sol-gel silica particles having a number average particle diameter of 108 nm and spraying a treatment agent on the particles suspended in the gas phase by spray drying. Then, it was crushed with a jet mill to obtain particles 1.

(Particle 2)
Particle 2 was obtained in the same manner except that sol-gel silica particles having a number average particle diameter of 65 nm were used as mother particles in the preparation of Particle 1.
(Particle 3)
Particle 3 was obtained in the same manner except that sol-gel silica particles having a number average particle diameter of 250 nm were used as mother particles in the preparation of Particle 1.
(Particle 4)
Particle 4 was obtained in the same manner except that sol-gel silica particles having a number average particle diameter of 45 nm were used as mother particles in the production of particle 1.
(Particle 5)
Particle 5 was obtained in the same manner except that sol-gel silica particles having a number average particle size of 410 nm were used as mother particles in the preparation of particle 1.

(Particle 6)
In the production of the particles 1, particles 6 were obtained in the same manner except that sol-gel silica particles having a number average particle size of 108 nm were used as mother particles and hexamethylsilazane was used instead of dimethyl silicone oil.
(Particle 7)
Particles 7 were obtained in the same manner except that 5 parts of dimethyl silicone oil having a viscosity of 50 cs was further used as the surface treating agent in the production of the particles 6.

(Particle 8)
Particle 8 was obtained in the same manner except that rutile-type titania particles having a number average particle size of 88 nm were used as mother particles in the production of particles 1.
(Particle 9)
Particle 9 was obtained in the same manner except that polymethylmethacrylate resin particles having a number average particle size of 152 nm were used as mother particles in the production of particle 1.

<Production of toner>
(Preparation of each dispersion)
-Resin particle dispersion-
450 parts of styrene, 25 parts of n-butyl acrylate, 5 parts of acrylic acid and 25 parts of dodecanethiol were mixed and dissolved in 10 parts of a nonionic surfactant (Nonipol 400, manufactured by Sanyo Chemical Co., Ltd.) and anion 10 parts of a surfactant (Neogen SC, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) is placed in a flask in which 650 parts of ion-exchanged water are dissolved, and emulsion polymerization is performed while slowly mixing at 80 ° C. for 30 minutes. 50 parts of ion-exchanged water in which the part was dissolved was added. After carrying out nitrogen substitution, the inside of the flask was stirred and heated in an oil bath until the content reached 75 ° C., and emulsion polymerization was continued for 4 hours.

  As a result, a resin particle dispersion was obtained in which emulsified particles having a volume average particle size of 142 nm, a glass transition point (Tg) of 54 ° C., and a weight average molecular weight Mw of 16000 were dispersed. The solid content concentration of this dispersion was 45%.

-Colorant dispersion-
Mix 60 parts of Cyan pigment (CI Pigment Blue 15: 3), 5 parts of nonionic surfactant (Nonipol 400, manufactured by Sanyo Kasei Co., Ltd.) and 240 parts of ion-exchanged water, and dissolve, homogenizer (Ultra) A colorant dispersant in which colorant (Cyan pigment) particles having a volume average particle diameter of 218 nm are dispersed by stirring with an optimizer for 30 minutes using a Thalax T50 (manufactured by IKA). Prepared.

-Release agent dispersion-
100 parts of paraffin wax (HNP0190, manufactured by Nippon Seiwa Co., Ltd., melting point: 86 ° C.), 5 parts of cationic surfactant (Sanisol B50, manufactured by Kao Corporation) and 240 parts of ion-exchanged water were added to round stainless steel. After being dispersed for 30 minutes using a homogenizer (Ultra Tarrax T50, manufactured by IKA) in a flask made, the release agent particles having a volume average particle diameter of 530 nm were dispersed by a dispersion treatment using a pressure discharge homogenizer. A mold dispersion was prepared.

(Production of toner particles)
-Toner particles 1-
・ 230 parts of resin particle dispersion ・ 20 parts of colorant dispersion ・ 50 parts of release agent dispersion ・ 1.0 part of polyaluminum hydroxide (Paho2S manufactured by Asada Chemical Co., Ltd.) ・ 800 parts of ion exchange Were mixed using a homogenizer (Ultra Turrax T50, manufactured by IKA) and dispersed. In order to agglomerate the particles, the inside of the flask was heated to 45 ° C. with stirring in a heating oil bath and held for 45 minutes, and then the temperature of the heating oil bath was further raised and held at 55 ° C. for 120 minutes. When the size of the aggregated particles in the slurry was measured, the volume average particle diameter was 6.5 μm.

Thereafter, in order to control the shape of the aggregated particles, 1N sodium hydroxide is added to the slurry containing the aggregated particles to adjust the pH of the system to 7.5, and then the stainless steel flask is sealed and magnetically sealed. The mixture was heated to 85 ° C. while stirring was continued for 4 hours. After cooling, the toner particles were filtered off, washed four times with ion exchange water, and then lyophilized to obtain toner particles 1.
Toner particles 1 had a volume average particle diameter of 7.4 μm and an average circularity of 0.985.

-Toner particles 2-
Toner particles 2 were prepared in the same manner except that the heating conditions and pH treatment conditions were changed. Toner particles 2 had a volume average particle diameter of 7.1 μm and an average circularity of 0.977.

-Toner particles 3-
Toner particles 3 were prepared in the same manner except that the heating conditions and pH treatment conditions were changed in the preparation of toner particles 1. Toner particles 3 had a volume average particle diameter of 7.2 μm and an average circularity of 0.965.

(Production of toner)
-Toner 1
1. To 100 parts of toner particles, 1.2 parts of metatitanic acid having a number average particle diameter of 22 nm and 2 parts of particles 1 treated with 3 parts of n-decyltrimethoxysilane were added at a peripheral speed of 30 m / sec with a 5 L Henschel mixer. After blending for 18 minutes, coarse particles were removed using a sieve having an opening of 45 μm to obtain toner 1.

-Toner 2-12-
Toners 1 to 12 were prepared in the same manner except that the toner particles and the external additive particles were changed as shown in Table 1 in the preparation of the toner 1. In the toner 9, blending was performed by adding 0.3 part of cerium oxide having a particle diameter of 600 nm in addition to 1: 2 parts of the particles.

<Preparation of developer>
3 parts of styrene-acrylic resin (styrene: methyl methacrylate = 20: 80, Mw: 30,000) was added to 40 parts of toluene to prepare a resin solution. 0.5 parts of carbon black was added to this resin solution, and this mixture was finely dispersed for 30 minutes using a sand mill to prepare a dispersion. 20 parts of this dispersion was mixed with 100 parts of ferrite particles having a volume average particle size of 50 μm. Furthermore, this mixture was put into a vacuum degassing type kneader, stirred for 30 minutes while being heated to 80 ° C., and further stirred under reduced pressure to remove the solvent. After removing the solvent, sieving was carried out with a 75 μm mesh to remove the aggregates, and carrier 1 was obtained.

  10 parts of each of toners 1 to 12 and 1: 100 parts of carrier were mixed using a V blender to prepare developers 1 to 12, respectively.

<Production of cleaning member>
(Cleaning member 1)
A non-woven fabric (toner holding function part) cut to a width of 11 mm and a length of 320 mm was wrapped around a sponge (elastic body) having a width of 5 mm, a length of 320 mm, and a thickness of 3 mm, leaving one surface with a width of 5 mm. The nonwoven fabric used at this time has a thickness of 0.3 mm using polyester fibers (thickness: 2.5 μm) and a basis weight (density) of 40 g / cm ² , and the sponge is a closed cell made of polyurethane resin as a raw material. An Asker C hardness of 12 degrees was used. The sponge bonded with a nonwoven fabric was fixed to a stainless steel support plate on the surface where the sponge was exposed to obtain the cleaning member 1.

(Cleaning member 2)
In the production of the cleaning member 1, the nonwoven fabric is cut into a width of 7.2 mm and a length of 320 mm, and wound around a sponge having a width of 1.2 mm, a length of 320 mm and a thickness of 3 mm, leaving one surface of the width of 1.2 mm. A cleaning member 2 was obtained in the same manner except that they were laminated.

(Cleaning member 3)
A non-woven fabric cut to a width of 26 mm and a length of 320 mm (same as that used for the cleaning member 1), a sponge having a width of 20 mm, a length of 320 mm and a thickness of 3 mm (same as that used for the cleaning member 1) Wrapped around each other leaving one side with a width of 20 mm. The nonwoven fabric bonded to the sponge was fixed to a stainless steel support plate having a shape along the rotational direction surface of the photoreceptor, which will be described later, on the surface where the sponge was exposed, to obtain the cleaning member 3.

(Cleaning member 4)
In the production of the cleaning member 1, the nonwoven fabric is cut into a width of 6.7 mm and a length of 320 mm, and wound around a sponge having a width of 0.7 mm, a length of 320 mm, and a thickness of 3 mm, leaving one surface of the width of 0.7 mm. A cleaning member 4 was obtained in the same manner except that they were laminated.

(Cleaning member 5)
In the production of the cleaning member 3, the nonwoven fabric was cut into a width of 33 mm and a length of 320 mm, and the same operation was performed except that the surface of the 27 mm width was wrapped around a sponge having a width of 27 mm, a length of 320 mm and a thickness of 3 mm. Thus, the cleaning member 5 was obtained.

(Cleaning member 6)
The same sponge as that used for the cleaning member 1 was cut into a width of 5 mm, a length of 320 mm, and a thickness of 3 mm, and a surface with a width of 5 mm was fixed to a stainless steel support plate to obtain a cleaning member 6.

(Cleaning member 7)
A plurality of polyester fiber nonwoven fabrics (same as those used for the production of the cleaning member 1) cut to a width of 5 mm and a length of 320 mm are laminated to a thickness of 3 mm, which is supported by stainless steel in a direction parallel to the nonwoven fabric surface. The cleaning member 7 was obtained by fixing to a plate.

(Cleaning member 8)
A cleaning blade made of urethane resin installed in the color copying machine Docu Center Color 400CP (manufactured by Fuji Xerox Co., Ltd.) was prepared without modification, and this was used as the cleaning member 8.

(Cleaning member 9)
A polyester fiber nonwoven fabric (the same as that used for the cleaning member 1) cut to a width of 20 mm and a length of 320 mm was wrapped around a stainless steel plate having a width of 8 mm, a length of 320 mm, and a thickness of 2 mm, and bonded together. This was fixed to a stainless steel support plate to obtain a cleaning member 9.

(Cleaning member 10)
The same sponge as that used for the cleaning member 1 was cut into a width of 5 mm, a length of 320 mm, and a thickness of 3 mm, and an OHP film for a laser printer having a width of 5 mm and a length of 320 mm was attached. The sponge bonded with the OHP film was fixed to the stainless steel support plate on the surface opposite to the surface where the OHP film was bonded to obtain the cleaning member 10.

(Cleaning member 11)
Silicone rubber (Asker C hardness: 15 degrees) was cut into a width of 5 mm, a length of 320 mm, and a thickness of 3 mm, and fixed to a stainless steel support plate to obtain a cleaning member 11.

(Cleaning member 12)
Silicone rubber (same as that used for the cleaning member 11), which was cut into a width of 11 mm and a length of 320 mm, and cut into a width of 5 mm, a length of 320 mm, and a thickness of 3 mm, from the same nonwoven fabric as that used for the cleaning member 1 ) And wrapped together. This silicone rubber laminated non-woven fabric was fixed to a stainless steel support plate to obtain a cleaning member 12.

<Example 1>
A photoconductor unit of an image forming apparatus Docu Center Color 400CP (peripheral speed of photoconductor: 194 mm / sec) manufactured by Fuji Xerox Co., Ltd. was prepared, the cleaning blade was removed, and the cleaning member 1 was remodeled. The pressing pressure of the cleaning member 1 against the photosensitive member was adjusted to 0.5 gf / cm ² (49.0 Pa). At this time, the contact nip width of the cleaning member 1 with the non-woven fabric photoreceptor was 5 mm (5.5% with respect to the entire circumference of the photoreceptor).
Further, the control computer unit of the image forming apparatus main body was modified so that an image can be output even in a single color and the image forming speed can be arbitrarily changed.

  The toner 1 is put into the toner cartridge used in the Docu Center Color 400CP, the developer 1 is put into the developing device used in the Docu Center Color 400CP, and the humidity is 88% RH by the modified image forming apparatus. After continuously printing 3000 sheets in an environment controlled at a temperature of 30 ° C., the power supply was shut off and left as it was overnight. The power was turned on again the next day, and 3000 sheets were printed continuously. Unless a serious abnormality occurred, this test was performed for 10 consecutive days, and a total of 30000 prints were made.

Regarding the image after printing 30000 sheets (including the state when it was canceled before 30000 sheets), the following confirmation items such as the image quality and the state of the image forming apparatus are judged according to the following criteria, and The cleaning property, toner cleaning property and the like were evaluated.
-Image quality check items: ground cover in background, image flow, fine line reproducibility (presence of scattering and blurring), homogeneity in highlight, solid image density and uniformity.
-Status check items of the image forming apparatus: abnormal noise during operation, toner contamination inside and around the apparatus, and the presence or absence of scratches on the electrostatic latent image carrier.

A: There is no problem with all the above confirmation items until the end of the test, and a high-quality image can be stably obtained.
○: Among the above confirmation items, some items are inferior in practical use but inferior items are recognized, or some items are inferior in only two hours or conditions during the test, but normal immediately It will not be a problem for actual use.
X: Among the image confirmation items and the state confirmation items of the image forming apparatus, one or more items are clearly inferior, which causes a problem in actual use.
XX: One or more of the image confirmation items and the state confirmation items of the image forming apparatus are remarkably inferior, and the test cannot be continued or difficult.
The results are shown in Table 2.

<Examples 2 to 16, Comparative Examples 1 to 11>
In Example 1, the evaluation was performed in the same manner except that the developer (toner) to be used, the cleaning member, the pressing condition to the photosensitive member, and the peripheral speed of the photosensitive member were changed as shown in Table 2. If a serious problem occurred during the test, printing was stopped at that time.
The results are summarized in Table 2.

  The results shown in Table 2 will be described in more detail. First, Example 1, Example 9, Example 13, and Example 14 have good fine line reproducibility and high-quality image quality with excellent halftone uniformity. It continued stably until the end of the experiment. In Example 2 and Example 16, the sample immediately after power-on after the 8th day of the experiment showed a slight fine line blur, but there was no problem after the second print and there was no problem in practical use. was.

  In Example 3, a slight rubbing noise between the photosensitive member and the cleaning member was heard during the experiment, but it was at a level causing no problem in practical use, and the print sample had good fine line reproducibility and excellent halftone homogeneity. High-quality image quality remained stable until the end of the experiment. In Example 4, scattering of fine lines from the initial stage of the experiment was observed, but there was no problem in practical use, and image output was performed stably until the end of the experiment. In Example 5, after a print of about 24,000 sheets, an extremely slight halftone rough feeling was recognized, but there was no problem in practical use.

  In Examples 6 and 12, there was no problem during the experiment. However, when the inside of the image forming apparatus was checked after the experiment was completed, extremely slight charger contamination was observed. The degree of contamination of the charger was light, and it was a level that did not disturb the image. In Example 7, the sample immediately after turning on the power on or after the seventh day of the experiment showed a slight fine line blur, but there was no problem after the second print, and there was no problem in practical use. In Example 8, the sample immediately after turning on the power on or after the 9th day of the experiment showed a slight thin line blur, but there was no problem after the second print, and there was no problem in practical use.

  In Example 10, the image quality was high and the operation of the image forming apparatus was stable without any problem, but the image output capability was low and the productivity was inferior. In Example 11, very slight streak-like stains were observed on about 28,000 print samples to about 0.5 out of 100 print samples. However, the degree of stains was light and there was no problem in practical use. It was. In Example 15, after a print of about 22,000 prints, an extremely slight halftone rough feeling was recognized, but there was no problem in practical use.

  On the other hand, in Comparative Example 1, streak-like stains and positive ghost-like image stains occurred on the print sample from the first print. The stains deteriorated every time printing was performed, and there were many stains that could not be identified as an image. Therefore, the experiment was stopped at the 35th print. In Comparative Example 2, the printed sample showed scattering of fine lines and uneven halftone from the beginning of the experiment, and the image quality was low and inferior to actual use. In Comparative Example 3, from about 5000 prints, the printed sample showed scattering of fine lines and uneven halftone, streak-like image smearing occurred from about 7500 sheets, and the image quality was inferior.

  In Comparative Example 4, white spots occurred in the printed image from about 500 prints, and the number of white spots increased thereafter. The image quality was inferior. In Comparative Example 5, image blurring was observed in the print sample immediately after the power was turned on after the second day of the experiment, and it deteriorated thereafter. Streaky stains were generated from about 21,000 prints, and the image quality was inferior. In Comparative Example 6, image blurring was observed in the print sample immediately after the power was turned on after the fourth day of the experiment, and the image quality deteriorated thereafter and the image quality was inferior. In Comparative Example 7, streaky density irregularities and image disturbances occurred on the print sample from about 7000 prints, and thereafter deteriorated and the image quality was inferior. After the experiment was completed, the inside of the image forming apparatus was confirmed, and the photosensitive member was found to have streak-like scratches in the circumferential direction.

  In Comparative Example 8, streak-like stains were generated on the print sample from about 4000 prints, and each time printing was performed, the image was extremely deteriorated and positive ghost-like image stains were produced from about 4500 prints. The experiment was interrupted. In Comparative Example 9, streaky density unevenness and image disturbance occurred on the print sample from about 1200 prints, and each time printing was performed, the experiment deteriorated. After the experiment was interrupted, the inside of the image forming apparatus was confirmed, and the photoconductor had streak-like scratches in the circumferential direction.

  In Comparative Example 10, streak-like stains were generated on the print sample from about 25 prints, and each time printing was performed, the experiment deteriorated. In Comparative Example 11, image blurring was observed in the print sample immediately after the power was turned on after the second day of the experiment, and it deteriorated thereafter. The image quality was inferior.

1 is a schematic cross-sectional view showing an electrophotographic apparatus which is an example of an image forming apparatus of the present invention.

Explanation of symbols

10 Electrophotographic photoreceptor (electrostatic latent image carrier)
11 Charger (charging means)
12 Power supply 13 Image input device (electrostatic latent image forming means)
14 Developer (Developing means)
15 Transfer device (transfer means)
16 Cleaning device (cleaning means)
17 Static eliminator 18 Fixing device 19 Cleaning member 20 Recording medium 21 Box

Claims (2)

A charging step for charging the surface of the electrostatic latent image carrier, a latent image forming step for forming an electrostatic latent image on the charged electrostatic latent image carrier, and a toner image with a developer containing toner. Image forming method comprising: a developing step for transferring, a transfer step for transferring the toner image to a recording medium or an intermediate transfer member, and a cleaning step for removing transfer residual toner remaining on the electrostatic latent image carrier after the transfer by a cleaning member In
The toner contains particles having a number average particle diameter of 60 to 300 nm surface-treated with silicone oil as an external additive, and the average circularity is in the range of 0.975 to 1.000.
The cleaning member includes a toner holding function part that contacts the surface of the electrostatic latent image carrier and an elastic body that supports the toner holding function part and presses the electrostatic latent image carrier, and the toner holding function. The portion is brought into contact with the electrostatic latent image carrier on a surface having a nip width of 1 mm or more in the moving direction of the electrostatic latent image carrier and 25% or less of the outer peripheral length of the electrostatic latent image carrier. An image forming method. A charging means for charging the surface of the electrostatic latent image carrier, a latent image forming means for forming an electrostatic latent image on the charged electrostatic latent image carrier, and a toner image obtained by developing the electrostatic latent image with a developer containing toner. An image forming apparatus including: a developing unit that performs transfer; a transfer unit that transfers the toner image to a recording medium or an intermediate transfer member; and a cleaning unit that removes transfer residual toner remaining on the electrostatic latent image carrier after the transfer by a cleaning member. ,
The toner contains particles having a number average particle diameter of 60 to 300 nm surface-treated with silicone oil as an external additive, and the average circularity is in the range of 0.975 to 1.000.
The cleaning member includes a toner holding function part that contacts the surface of the electrostatic latent image carrier and an elastic body that supports the toner holding function part and presses the electrostatic latent image carrier, and the toner holding function. The portion contacts the electrostatic latent image carrier on a surface having a nip width of 1 mm or more in the moving direction of the electrostatic latent image carrier and 25% or less of the outer peripheral length of the electrostatic latent image carrier. An image forming apparatus.

Images