JP2009086640A - Image forming method, image forming apparatus, and process cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming method capable of preventing an abnormal image from being generated caused by defective cleaning, capable of preventing an image carrier from being abraded, capable of preventing a cleaning blade from being abraded, capable of preventing an abnormal image from being generated caused by image deflection or the like, at the same time, and capable of prolonging a service life of an image forming apparatus, in the image forming method using water granulated toner. <P>SOLUTION: This image forming method for developing a latent image formed on the image carrier, using the water granulated toner, and for transferring a formed toner image directly or indirectly onto a recording paper sheet, is provided, as subsequent processes of a transfer process, with a cleaning process for cleaning transfer residual toner on the image carrier by a cleaning blade, and a lubricant applying process for applying a lubricant onto a surface of the image carrier, and the water granulated toner used therein has 2.5 to 7.0 m<SP>2</SP>/g of BET specific surface area. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image forming method and apparatus using an electrophotographic method applicable to an image forming apparatus such as a copying machine and a printer, and more specifically, a toner image formed on an image carrier is directly or indirectly transferred to a recording sheet. The present invention relates to an image forming method (image forming apparatus) having a transfer step (transfer unit), a cleaning step (cleaning unit) on the image carrier, and a lubricant application step (lubricant application unit) on the image carrier.

  In the image forming method using the electrophotographic method, for example, as shown in the image forming apparatus of FIG. 12, the image forming area on the surface of the image carrier 8 is uniformly charged by the charging means 1 and the image carrier 8 is exposed by the exposure means 2. Then, an image is formed by toner triboelectrically charged on the image carrier 8 by the developing means 3. Thereafter, the image on the image carrier 8 is transferred directly to the recording paper conveyed from the paper feeding means 9 by the transfer means 4 or indirectly via an intermediate transfer body (not shown), and the image on the recording paper is fixed by the fixing means 10. The image is fixed.

  Conventionally, corotron chargers using corona discharge, scorotron chargers and the like have been mainstream as charging means 1 for charging the image carrier 8. However, the charging means using the corona discharge has a problem that a large amount of ozone is generated or nitrogen oxide NOx generated by the corona discharge adheres to the image carrier 8 and causes problems such as image flow over time. was there. Further, in order to perform corona discharge, a high voltage power supply that applies a high voltage of 5 to 10 kV to the charge wire is necessary, and it is difficult to reduce the cost of the image forming apparatus.

  Therefore, in recent years, as a charging unit that can be employed in an image forming apparatus, a contact-type charging unit that does not use corona discharge and makes the charging unit contact the image carrier, or a proximity type that makes the charging unit close to the image carrier. Many charging means have been proposed. In this contact type / proximity type charging means (in general, a charging roller is used, but a charging member such as a fur brush, a magnetic brush, or a blade may be used), charging using the corona discharge is performed. While many of the problems mentioned in the case of the means are solved, there is a problem that the wear amount of the image carrier increases and the life is shortened. In addition, when alternating current is used as the applied voltage, noise is also a problem. In addition, since the charging means rubs toner or paper powder against the image carrier, the contamination of the surface of the image carrier is promoted, and there is a problem that the surface of the charging means is soiled.

  Next, the developer used in the developing means includes a two-component developer composed of toner and carrier and a one-component developer composed of only magnetic or non-magnetic toner. The production of these toners is generally a kneading and pulverizing method in which a resin, a pigment, a charge control agent, and a release agent are melt-kneaded, cooled and then pulverized and classified, but the particle size and shape are not uniform. It was difficult to control.

  For this reason, in recent years, there has been an attempt to intentionally control the particle size of toner particles to solve the above-mentioned problems, and toner methods such as an emulsion polymerization method and a solution suspension method have been used for aqueous granulation. It became prosperous.

  In recent years, there has been an increasing demand for higher image quality, and in particular, in order to realize a high-definition image in the formation of a color image, there has been an increasing demand for toner having a smaller diameter and a uniform particle size. This is because fine toner particles contaminate the developing sleeve, contact / proximity charging means, cleaning blade, photoconductor (image carrier), carrier, etc. when toner is formed using a toner having a wide particle size distribution, or toner scattering. This is because the problem of occurrence of image quality increases and it is difficult to simultaneously achieve high image quality and high reliability. On the other hand, when the particle size is uniform and the particle size distribution is sharp, the development behavior of individual toner particles is uniform, and the fine dot reproducibility can be greatly improved.

  However, the spherical toner granulated in water system has a problem with respect to cleaning properties. In particular, it is impossible to stably clean the toner (residual toner) remaining on the image carrier by blade cleaning. That is, when such a spherical toner is used, after the toner image is transferred from the photosensitive member carrying the toner image to a recording paper or the like, residual toner remaining on the surface of the photosensitive member is removed with a cleaning blade. The spherical toner easily slips between the cleaning blade and the surface of the photoconductor on which the cleaning blade is in contact, and a cleaning failure of residual toner on the surface of the photoconductor tends to occur. Spherical toner cleaning failure is due to the momentary rotational driving force that occurs when the spherical toner contacts the insulating cleaning blade due to the adhesion force and friction coefficient between the spherical toner and the photoreceptor, and the toner passes through while rotating. A hypothetical mechanism that occurs is considered.

  In view of this, various methods have been proposed for improving the cleaning property by devising the toner production method and the toner constituent materials. As one of them, there is a method for changing the shape of the toner from a spherical shape. By changing the shape of the toner, the toner can be blocked by the blade, and the blade can be cleaned. However, if the degree of toner deformation is excessively large, the behavior of the toner becomes unstable during development and the like, and the fine dot reproducibility deteriorates. As described above, characteristics such as toner transfer quality, transfer efficiency, and cleaning performance are affected by the toner shape. Therefore, in order to obtain a toner having the above characteristics, an optimum design of the toner shape distribution is required.

Although there is no description regarding cleaning properties in Patent Document 1, the specific surface area of a toner base produced by heat treatment after pulverization is Sb (m ² / g), the volume average particle diameter is Dv, and the specific gravity is Hb (g / cm ³ ). When Sb × Dv × Hb is 6.0, a true sphere shape is obtained (the same document, page 4, left column, line 31), and the toner base is 6 ≦ Sb × Dv × Hb ≦ 30, and It is described that high density and high image quality with low fog can be realized by using a configuration having specific saturation magnetization.

  By the way, the cleaning method of the image forming apparatus in the electrophotographic method is mainly a cleaning method using a blade, and there are many image forming apparatuses having cleaning means only for the blade. Some high-speed machines are provided with a cleaning assisting means in order to avoid a state in which a large amount of toner has partially adhered to the cleaning blade. This is installed upstream of the cleaning means and mechanically disturbs the toner input to the cleaning means to improve the cleaning performance.

  Under such circumstances, the use of water-based granulated toner is desired in order to obtain a higher quality image, but it is difficult to ensure the cleaning property as described above. Therefore, in the case of using a toner having a high sphericity, the image carrier is provided with a means for applying a lubricant to improve the margin of cleaning performance, to protect the surface of the image carrier and to prevent filming. There are many cases.

  Although there is no description regarding lubricant application in Patent Document 2, it is described that fine particle toner produced by soap-free emulsion polymerization or the like is excellent in charging property, fixing property, cleaning property, and heat resistance (the same document, (Refer to page 2, upper right column, line 5 to lower left column, last line).

  Conventionally, there have been many proposals regarding an application mechanism (means) for applying a lubricant to the surface of an image carrier (see, for example, Patent Documents 3 to 7).

  Further, as a charging means, a charging means for charging by discharging in a minute gap between the image carrier and the charging means is known. When such a charging means is used, the image quality and the cleaning property, the image carrier surface From the viewpoint of protection, it is essential to apply a lubricant. In order to provide a longer-life image forming apparatus, it is necessary to prevent the cleaning blade from being accelerated due to an increase in the coefficient of friction of the image carrier surface when the lubricant deteriorates. Here, as means for preventing the wear of the cleaning blade from being accelerated, (1) making the lubricant difficult to deteriorate, and (2) presenting a cleaning blade that does not promote wear even if the image carrier surface friction coefficient increases. And (3) removing the deteriorated lubricant on the surface of the image carrier from the surface of the image carrier.

On the other hand, when using a charging means that does not rely on discharge in a minute gap between the image carrier and the charging means, it is essential to apply a lubricant from the viewpoint of image quality and cleanability. Since the lubricant does not deteriorate, the wear of the cleaning blade is reduced and the life can be extended. However, when such a corona charger is used, ozone O ₃ and nitrogen oxides NOx are generated, and discharge products such as NOx in particular are present on the surface of the image carrier, as has been conventionally considered. Deteriorate the image by sticking to it. That is, in order to perform stable image output over a long period of time, the following three means, namely (1) make it difficult for the discharge product to adhere, and (2) no image deterioration even if the discharge product adheres. It is conceivable to employ an image forming method, to remove discharge products adhering to the surface of the image carrier from the surface of the image carrier.

  From the above, regardless of which charging means is used, removing foreign matter (deteriorated lubricant or discharge product) adhering to the surface of the image carrier from the surface of the image carrier is more stable image formation. It is important to do. As a conventional example, as shown in Patent Document 8, a discharge product removing member that contacts the surface of the image carrier is provided, the discharge product is blocked by the member, and a part of the discharge product is absorbed by the member. An image forming apparatus for removing a discharge product that has been blocked by a cleaning blade is described, and the removal member is composed of an elastic water-containing member and a highly water-absorbing member hermetically sealed around the outside of a core shaft such as metal (See the same document, paragraph [0027] and the following). Further, as shown in Patent Document 9, an image formed by a rotating image forming unit selected by an intermediate transfer member contacting / separating unit and specified as an intermediate transfer member on which a toner image formed by an image forming unit is intermediately transferred. An image forming apparatus is described in which deposits on an image carrier of another image forming unit are removed by a deposit removing means while the image forming unit selected and specified is brought into contact with and separated from the carrier. (See ibid, paragraph [0010] et seq.).

JP-A-6-317928 JP-A-1-257857 JP 2002-244516 A JP 2002-156877 A JP 2002-55580 A JP 2002-244487 A JP 2002-229227 A JP 2002-162881 A JP 2004-20660 A

  The present invention has been made in view of the above problems, and in an image forming method and apparatus that employs any type of charging means and uses water-based granulated toner, foreign matter (deteriorated) that adheres to the surface of the image carrier. An image forming method and apparatus capable of removing a lubricant and a discharge product) from the surface of the image carrier, maintaining a fresh image carrier surface, and outputting a stable image while achieving a long life. The purpose is to provide.

In order to solve the above problems, the invention described in claim 1 is a charging step for charging the surface of an image carrier made of an electrophotographic photosensitive member, and a latent image is formed by exposing the surface of the charged image carrier. A developing process in which the formed latent image is developed with toner to form a visible image, a transferring process in which the formed toner image is transferred onto the transfer medium directly or via an intermediate transfer member, on the transfer medium In an image forming method having a fixing step of fixing the toner image of
As a post-step of the transfer step, a cleaning step of cleaning the transfer residual toner remaining on the surface of the image carrier with a cleaning blade and a lubricant application step of applying a lubricant to the surface of the image carrier are provided. Is a water-based granulated toner and is characterized by using a toner having the following requirements (1) to (4).
(1) Volume average particle diameter Dv is in the range of 3.0 μm ≦ Dv ≦ 7.0 μm (2) Average value of shape factor SF-1 is between 120 and 160 (3) Shape factor SF− The average value of 2 is between 100 and 140. (4) The BET specific surface area is 2.5 to 7.0 (m ² / g).

  According to a second aspect of the present invention, in the image forming method according to the first aspect, the charging means in the charging step uses a charging means that does not depend on a discharge in a minute gap between the charging means and the image carrier. Features.

  According to a third aspect of the present invention, in the image forming method according to the first or second aspect, the volume average particle diameter Dv of the toner is in a range of 3.0 μm ≦ Dv ≦ 5.5 μm.

  According to a fourth aspect of the present invention, in the image forming method according to the first or second aspect, the volume average particle diameter Dv of the toner is in the range of 5.0 μm ≦ Dv ≦ 5.5 μm.

  According to a fifth aspect of the present invention, in the image forming method according to any one of the first to fourth aspects, a corona charger is used as the charging means in the charging step.

  A sixth aspect of the present invention is the image forming method according to any one of the first to fifth aspects, wherein the toner is a layered material in which at least a binder resin, a colorant, and a metal cation are modified with an organic cation. It comprises toner base particles containing an inorganic mineral and an external additive.

According to a seventh aspect of the present invention, in the image forming method according to any one of the first to sixth aspects, the BET specific surface area of the external additive contained per unit weight of the toner is 0.5 to It is 3.5 (m ² / g).

  According to an eighth aspect of the present invention, in the image forming method according to any one of the first to seventh aspects, the toner has a ratio of a volume average particle diameter (Dv) to a number average particle diameter (Dn) (Dv / 7. The image forming method according to claim 1, wherein Dn) is in the range of 1.00 to 1.40.

  According to a ninth aspect of the present invention, in the image forming method according to any one of the first to eighth aspects, the toner has 1 to 10% by number of particles of 2 μm or less.

According to a tenth aspect of the present invention, in the image forming method according to any one of the first to ninth aspects, the toner has an average primary particle size of 50 to 500 nm on the toner base particle surface and a bulk density of 0.3 g. It is a toner obtained by externally adding fine particles of / cm ³ or more.

  According to an eleventh aspect of the present invention, in the image forming method according to any one of the first to tenth aspects, the image carrier is an organic photoreceptor having a surface layer in which a filler is dispersed. .

  According to a twelfth aspect of the present invention, in the image forming method according to any one of the first to tenth aspects, the image carrier is an organic photoreceptor having a protective layer using a crosslinkable charge transport material, or a filler. And an organic photoreceptor having a protective layer using a crosslinkable charge transport material.

  According to a thirteenth aspect of the present invention, in the image forming method according to any one of the first to tenth aspects, the image carrier is an amorphous silicon photoconductor.

According to a fourteenth aspect of the present invention, there is provided an image carrier comprising an electrophotographic photosensitive member, a charging means for charging the surface of the image carrier, and formation of a latent image for forming a latent image by exposing the charged image carrier surface. Means, developing means for visualizing the formed latent image using toner, transfer means for transferring the formed toner image directly or via an intermediate transfer member onto a transfer medium, transfer In an image forming apparatus provided with at least fixing means for fixing a toner image on a medium,
A cleaning means for cleaning the transfer residual toner remaining on the surface of the image carrier with a cleaning blade and a lubricant application means for applying a lubricant to the surface of the image carrier, downstream of the transfer means, and the toner Is a water-based granulated toner having the following requirements (1) to (4).
(1) Volume average particle diameter Dv is in the range of 3.0 μm ≦ Dv ≦ 7.0 μm (2) Average value of shape factor SF-1 is between 120 and 160 (3) Shape factor SF− The average value of 2 is between 100 and 140. (4) The BET specific surface area is 2.5 to 7.0 (m ² / g).

  According to a fifteenth aspect of the present invention, in the image forming apparatus according to the fourteenth aspect, a charging unit that does not depend on a discharge in a minute gap between the charging unit and the image carrier is used as the charging unit. .

  According to a sixteenth aspect of the present invention, in the image forming apparatus according to the fourteenth or fifteenth aspect, the toner has a volume average particle diameter Dv in a range of 3.0 μm ≦ Dv ≦ 5.5 μm.

  According to a seventeenth aspect of the present invention, in the image forming apparatus according to the fourteenth or fifteenth aspect, the toner has a volume average particle diameter Dv in a range of 5.0 μm ≦ Dv ≦ 5.5 μm.

  According to an eighteenth aspect of the present invention, there is provided a process cartridge for use in the image forming apparatus according to any one of the fourteenth to seventeenth aspects, wherein the process cartridge is at least selected from an image carrier, a charging unit, a developing unit, and a cleaning unit. One means is integrally supported and is detachable from the main body of the image forming apparatus.

  According to the image forming method of the present invention, the volume average particle diameter Dv and the shape factor (SF-1, SF-2) of the water-based granulated toner used in the development step are specified, and the BET specific surface area is set within the specified range. Therefore, when a toner image is formed by development on the image carrier, stable image formation can be performed over a long period of time by the above-described various types of charging means.

  For example, when a charging means (for example, corona charging) that does not rely on a discharge in a minute gap between the charging means and the image carrier is employed, the discharge product generated by the charging is adsorbed by the toner, and the transfer process or When the toner is removed from the image carrier in the cleaning step, the discharge product is also removed from the image carrier together with the toner, so that the discharge product does not accumulate on the surface of the image carrier. For this reason, it is possible to perform good image formation over time without generating an abnormal image such as image flow.

  Further, even when a charging means by discharging in a minute gap between the charging means and the image carrier (charging means by proximity discharge) is used, the BET specific surface area of the water-based granulated toner used in the development process is within the above specific range. Therefore, when a toner image is formed by development on the image carrier, the deteriorated lubricant is adsorbed by the toner, and when the toner is removed from the image carrier in the transfer step or cleaning step, The lubricant that has deteriorated together with the toner is also removed from the image carrier. For this reason, it is possible to prevent an increase in the coefficient of friction on the surface of the image bearing member and premature wear of the cleaning blade, thereby extending the life of the image forming apparatus.

Among the above-mentioned charging means, towards the charging means and the charging means does not depend on the discharge in a minute gap between the image bearing member (e.g., corona charging) is referred to the production of occurrence and nitrogen oxides NO _X ozone can be suppressed In this respect, it can be said that this is a more preferable form than a charging means by discharging in a minute gap between the charging means and the image carrier (charging means by proximity discharge).

  Further, according to the image forming apparatus and the process cartridge in which the image forming method is performed, it is possible to provide an image forming apparatus and a process cartridge capable of performing stable image formation over a long period of time.

Hereinafter, the present invention will be described in detail.
The present invention relates to an image forming method in which a toner image formed on an image carrier is formed using water-based granulated toner, and the toner image is transferred directly or indirectly to a recording paper. A cleaning process for cleaning the transfer residual toner remaining on the surface of the image carrier with a cleaning blade, and a lubricant application process for applying a lubricant to the surface of the image carrier. By using the toner having the requirements (1) to (4), an image forming method capable of forming a stable image without generating an abnormal image over a long period of time is obtained.
(1) Volume average particle diameter Dv is in the range of 3.0 μm ≦ Dv ≦ 7.0 μm (2) Average value of shape factor SF-1 is between 120 and 160 (3) Shape factor SF− The average value of 2 is between 100 and 140. (4) The BET specific surface area is 2.5 to 7.0 (m ² / g).

  Toner that is granulated in water is often spherical, and a high-quality image can be obtained, but it tends to cause poor cleaning. Therefore, it is necessary to apply a lubricant to the image carrier to improve the cleaning margin. However, when the lubricant is applied to the surface of the image carrier, if the charging means is a charging means (proximity or contact charging means) by discharging in a minute gap between the charging means and the image carrier, the surface of the lubricant is charged. Due to the discharge caused by the above, the cleaning blade is worn by being deteriorated and the coefficient of friction of the surface is increased. For this reason, in a system using charging means by discharging in a minute gap between the charging means and the image carrier, the system can be used stably over a long period of time unless the deteriorated lubricant on the surface of the image carrier is removed. I can't. On the other hand, in a system using a charging means that does not depend on discharge in a minute gap between the charging means and the image carrier, for example, a corona charging means, it is possible to prevent premature wear of the cleaning blade, but it accumulates on the image carrier. If the discharge product is not removed, stable high image quality cannot be obtained over a long period of time.

  In view of such a background, the present inventors use a cleaning blade to clean the transfer residual toner remaining on the surface of the image carrier as a subsequent process of the transfer process when image formation is performed using water-based granulated toner. A cleaning step and a lubricant application step for applying a lubricant to the surface of the image carrier, and if the BET specific surface area of the water-based granulated toner is defined within a specific range, when a corona charging means is used, It has been found that the discharge product on the surface of the image carrier can be removed, and that a deteriorated lubricant on the surface of the image carrier can be removed when charging means using proximity discharge is used.

That is, by defining the BET specific surface area of the water-based granulated toner in the range of 2.5 to 7.0 (m ² / g), when a toner image is formed by development on the image carrier, The discharge product generated by the charging means, for example, the corona charging means, which is not caused by the discharge in the minute gap between the image carriers is adsorbed by the toner, and the toner is removed from the image carrier in the transfer process or the cleaning process. At that time, it was recognized that the discharge products were also removed from the image carrier at the same time.
In addition, in the case where a charging means by discharging in a minute gap between the charging means and the image carrier (charging means by proximity discharge) is used, the toner is removed from the image carrier in the transfer process or the cleaning process. At the same time, it was observed that the deteriorated lubricant on the surface of the image bearing member was removed at the same time.

  In this case, the toner has a volume average particle diameter Dv of 3.0 μm ≦ Dv ≦ 7.0 μm, an average value of the shape factor SF-1 between 120 and 160, and an average value of the shape factor SF-2 of 100. It must be between ~ 140. The volume average particle diameter Dv is preferably in the range of 3.0 ≦ Dv ≦ 5.5 μm, more preferably in the range of 5.0 ≦ Dv ≦ 5.5 μm.

In addition, the BET specific surface area is set in the range of 2.5 to 7.0 (m ² / g) because when the BET specific surface area is smaller than 2.5 (m ² / g), the discharge product is removed. In time, discharge products accumulate on the surface of the image carrier, resulting in an abnormal image. On the other hand, when the BET specific surface area is larger than 7.0 (m ² / g), it has been confirmed that the image quality is remarkably deteriorated and cannot be used as a toner.

<About the shape factor>
FIG. 9 is a diagram schematically illustrating the shape of the toner in order to explain the shape factor SF-1 and the shape factor SF-2. The shape factor SF-1 indicates the ratio of the roundness of the toner shape and is represented by the following formula (1). This is a value obtained by dividing the square of the maximum length MXLNG of the shape formed by projecting the toner on a two-dimensional plane by the figure area AREA and multiplying by 100π / 4.

[Equation 1]
Formula (1)
SF-1 = {(MXLNG) ² / AREA} × (100π / 4)
When the value of SF-1 is 100, the shape of the toner is a true sphere, and becomes larger as the value of SF-1 increases.

  The shape factor SF-2 indicates the ratio of the unevenness of the toner shape, and is represented by the following formula (2). A value obtained by dividing the square of the perimeter PERI of the figure formed by projecting the toner on the two-dimensional plane by the figure area AREA and multiplying by 100π / 4.

[Equation 2]
Formula (2)
SF-2 = {(PERI) ² / AREA} × (100π / 4)
When the value of SF-2 is 100, there is no unevenness on the toner surface, and as the value of SF-2 increases, the unevenness of the toner surface becomes more prominent.

Specifically, the shape factor is measured by randomly sampling 300 SEM images of toner obtained by FE-SEM (S-4200) manufactured by Hitachi, Ltd., and using the image information via the interface. Analysis was performed by introducing the image into an image analysis apparatus (Luzex AP) manufactured by Nireco Corporation, and values obtained from the above equations were defined as SF-1 and SF-2.
The values of SF-1 and SF-2 are preferably values obtained by the above Luzex, but are not particularly limited to the FE-SEM device and the image analysis device as long as similar analysis results can be obtained.

  When the shape of the toner is close to a spherical shape, the contact state between the toner and the toner or the toner and the photoconductor becomes a point contact, so that the adsorbing force between the toners becomes weak and the fluidity increases, and the toner and the photoconductor The attraction force becomes weaker and the transfer rate becomes higher. If any of the shape factors SF-1 and SF-2 exceeds 180, the transfer rate is lowered, which is not preferable.

<BET specific surface area>
The BET specific surface area (m ² / g) is determined according to the BET method by using a device capable of complying with JIS standards (Z8830 and R1626) such as a specific surface area measuring device Autosorb 1 (NOVA series manufactured by Yuasa Ionics). Gas can be adsorbed and measured using the BET multipoint method.

<Constituent Material of Toner of the Present Invention and Toner Production Method>
The toner of the present invention preferably includes at least a binder resin, a colorant, toner base particles containing a layered inorganic mineral obtained by modifying at least a part of a metal cation with an organic cation, and an external additive. That is, as a means for obtaining the BET specific surface area of the toner, it is effective to contain in the toner a layered inorganic mineral (organic modified clay) in which at least a part of the metal cation is modified with an organic cation.

  Further, this toner includes a prepolymer composed of at least a binder resin and a modified polyester resin in an organic solvent, a compound that extends or crosslinks with the prepolymer, a colorant, a release agent, and at least a metal cation contained in the layered inorganic mineral. It is produced from a solution or dispersion in which a layered inorganic mineral (organic modified clay) at least partially modified with an organic cation is dissolved or dispersed, and the layered inorganic mineral is produced from the solution or dispersion. The toner solid content is preferably adjusted to be 0.05 to 10% by weight. If it is less than 0.05% by weight, the target Casson yield value may not be obtained, and if it exceeds 10% by weight, the fixing performance is likely to deteriorate.

  Further, the Casson yield value at 25 ° C. of the solution or dispersion is desirably 1 to 100 Pa, and the dispersion obtained by subjecting the solution or dispersion to a crosslinking reaction and / or extension reaction in an aqueous medium. A toner obtained by removing the solvent from the liquid is desirable. If the Casson yield value is less than 1 Pa, it is difficult to obtain the target shape, and if it exceeds 100 Pa, the productivity is likely to deteriorate.

The toner is preferably manufactured under the above-described manufacturing conditions, and is a toner granulated in an aqueous system, the volume average particle diameter Dv is in the range of 3.0 μm ≦ Dv ≦ 7.0 μm, and the average value of the shape factor SF-1 is The toner base particles having an average value of 120 to 160, an average shape factor SF-2 of 100 to 140, and a BET specific surface area of 2.5 to 7.0 (m ² / g) can be easily produced. Thereby, when an external additive is externally added to the toner base particles, a toner having a BET specific surface area of 2.5 to 7.0 (m ² / g) can be produced.

<Layered inorganic mineral in which at least part of metal cation is modified with organic cation>
Examples of the layered inorganic mineral obtained by modifying at least a part of the metal cation used in the toner of the present invention with an organic cation include organic modified montmorillonite and organic modified smectite.
Examples of organic cation modifiers that provide organic cations include quaternary alkyl ammonium salts, phosphonium salts, and imidazolium salts, with quaternary alkyl ammonium salts being preferred. Examples of the quaternary alkyl ammonium include trimethyl stearyl ammonium, dimethyl stearyl benzyl ammonium, dimethyl octadecyl ammonium, oleyl bis (2-hydroxyethyl) methyl ammonium, and the like.

<Casson yield measurement method>
The Casson yield value can be measured using a high shear viscometer or the like.
The measurement conditions are as follows.
Device: AR2000 (TA Instruments)
Shear stress 120Pa / 5min Geometry: 40mm steel plate Geometry gap: 1mm
Analysis software: TA DATA ANALYSIS (TA Instruments)

Hereinafter, the constituent material and the manufacturing method of the toner will be described.
The toner suitably used in the image forming method of the present invention is a water-based toner material liquid in which at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent are dispersed in an organic solvent. A toner obtained by crosslinking and / or elongation reaction in a solvent.

<Polyester>
The polyester is obtained by a polycondensation reaction between a polyhydric alcohol compound and a polycarboxylic acid compound.
Examples of the polyhydric alcohol compound (PO) include dihydric alcohol (DIO) and trihydric or higher polyhydric alcohol (TO). (DIO) alone or a mixture of (DIO) and a small amount of (TO) preferable.

Examples of the dihydric alcohol (DIO) include alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (diethylene glycol) , Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol) F, bisphenol S, etc.); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol; Alkylene oxide bisphenol (ethylene oxide, propylene oxide, butylene oxide, etc.), etc. adducts.
Among these, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use.

  As trihydric or higher polyhydric alcohol (TO), trihydric or higher polyhydric aliphatic alcohol (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (Trisphenol PA, phenol novolak, cresol novolak, etc.); and alkylene oxide adducts of the above trivalent or higher polyphenols.

Examples of the polyvalent carboxylic acid (PC) include divalent carboxylic acid (DIC) and trivalent or higher polyvalent carboxylic acid (TC). (DIC) alone and (DIC) and a small amount of (TC) Mixtures are preferred.
Divalent carboxylic acids (DIC) include alkylene dicarboxylic acids (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acids (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid) And naphthalenedicarboxylic acid). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms.
Examples of the trivalent or higher polyvalent carboxylic acid (TC) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). In addition, as polyhydric carboxylic acid (PC), you may make it react with polyhydric alcohol (PO) using the above-mentioned acid anhydride or lower alkyl ester (Methyl ester, ethyl ester, isopropyl ester, etc.).

  The ratio of the polyhydric alcohol (PO) to the polycarboxylic acid (PC) is usually 2/1 to 1/1, preferably as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. Is 1.5 / 1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.

  The polycondensation reaction between a polyhydric alcohol (PO) and a polycarboxylic acid (PC) is carried out in the presence of a known esterification catalyst such as tetrabutoxytitanate or dibutyltin oxide, and heated to 150 to 280 ° C. while reducing the pressure as necessary. The produced water is distilled off to obtain a polyester having a hydroxyl group. The hydroxyl value of the polyester is preferably 5 or more, and the acid value of the polyester is usually 1 to 30, preferably 5 to 20. By giving an acid value, the toner tends to be negatively charged, and further, when fixing to a recording paper, the affinity between the recording paper and the toner is good and the low-temperature fixing property is improved. However, when the acid value exceeds 30, there is a tendency to deteriorate with respect to the stability of charging, particularly environmental fluctuation.

  The weight average molecular weight is 10,000 to 400,000, preferably 20,000 to 200,000. A weight average molecular weight of less than 10,000 is not preferable because offset resistance deteriorates. On the other hand, if it exceeds 400,000, the low-temperature fixability is deteriorated.

  In addition to the unmodified polyester obtained by the above polycondensation reaction, the polyester preferably contains a urea-modified polyester. The urea-modified polyester is obtained by reacting a terminal carboxyl group or hydroxyl group of the polyester obtained by the above polycondensation reaction with a polyvalent isocyanate compound (PIC) to obtain a polyester prepolymer (A) having an isocyanate group. It is obtained by cross-linking and / or extending the molecular chain by the reaction of the amine with amines.

  Examples of the polyvalent isocyanate compound (PIC) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.) Aromatic diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanates; Those blocked with caprolactam or the like; and combinations of two or more of these.

  The ratio of the polyvalent isocyanate compound (PIC) is usually 5/1 to 1/1, preferably as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. 4/1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. When the molar ratio of [NCO] is less than 1, when a urea-modified polyester is used, the urea content in the ester is lowered and hot offset resistance is deteriorated.

  The content of the polyisocyanate compound (PIC) component in the polyester prepolymer (A) having an isocyanate group is usually 0.5 to 40 wt%, preferably 1 to 30 wt%, more preferably 2 to 20 wt%. . If it is less than 0.5 wt%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40 wt%, the low-temperature fixability deteriorates.

  The number of isocyanate groups contained per molecule in the polyester prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2 on average. Five. If it is less than 1 per molecule, the molecular weight of the urea-modified polyester will be low, and the hot offset resistance will deteriorate.

  Next, as amines (B) to be reacted with the polyester prepolymer (A), a divalent amine compound (B1), a trivalent or higher polyvalent amine compound (B2), an amino alcohol (B3), an amino mercaptan (B4) ), Amino acid (B5), and amino acids B1 to B5 blocked (B6).

  Examples of the divalent amine compound (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′-dimethyldicyclohexyl). Methane, diamine cyclohexane, isophorone diamine, etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.).

Examples of the trivalent or higher polyvalent amine compound (B2) include diethylenetriamine and triethylenetetramine.
Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline.
Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan.
Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid.
Examples of the compound (B6) obtained by blocking the amino group of B1 to B5 include ketimine compounds and oxazolidine compounds obtained from the amines of B1 to B5 and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.).

  Among these amines (B), preferred are B1 and a mixture of B1 and a small amount of B2.

  The ratio of amines (B) is equivalent to the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the polyester prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). Is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2. When [NCO] / [NHx] is more than 2 or less than 1/2, the molecular weight of the urea-modified polyester is lowered, and the hot offset resistance is deteriorated.

  The urea-modified polyester may contain a urethane bond together with a urea bond. The molar ratio of the urea bond content to the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance is deteriorated.

  The urea-modified polyester is produced by a one-shot method or the like. Polyhydric alcohol (PO) and polyvalent carboxylic acid (PC) are heated to 150-280 ° C. in the presence of a known esterification catalyst such as tetrabutoxytitanate, dibutyltin oxide, etc., and water produced while reducing the pressure as necessary. Distill off to obtain a polyester having a hydroxyl group. Subsequently, at 40-140 degreeC, this is made to react with polyvalent isocyanate (PIC), and the polyester prepolymer (A) which has an isocyanate group is obtained. Further, this (A) is reacted with amines (B) at 0 to 140 ° C. to obtain a urea-modified polyester.

  When reacting (PIC) and when reacting (A) and (B), a solvent may be used if necessary. Usable solvents include aromatic solvents (toluene, xylene, etc.); ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.); esters (ethyl acetate, etc.); amides (dimethylformamide, dimethylacetamide, etc.) and ethers And those inert to isocyanates (PIC), such as tetrahydrofuran (such as tetrahydrofuran).

  In addition, in the crosslinking and / or extension reaction between the polyester prepolymer (A) and the amines (B), a reaction terminator can be used as necessary to adjust the molecular weight of the resulting urea-modified polyester. Examples of the reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those blocked (ketimine compounds).

  The weight average molecular weight of the urea-modified polyester is usually 10,000 or more, preferably 20,000 to 10,000,000, and more preferably 30,000 to 1,000,000. If it is less than 10,000, the hot offset resistance deteriorates. The number average molecular weight of the urea-modified polyester or the like is not particularly limited when the above-mentioned unmodified polyester is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. When the urea-modified polyester is used alone, the number average molecular weight is usually 2000 to 15000, preferably 2000 to 10,000, and more preferably 2000 to 8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color device are deteriorated.

  By using the unmodified polyester and the urea-modified polyester in combination, the low-temperature fixability and the glossiness when used in a full-color image forming apparatus are improved. Therefore, it is preferable to use the urea-modified polyester alone. The unmodified polyester may include a polyester modified with a chemical bond other than a urea bond.

  The unmodified polyester and the urea-modified polyester are preferably at least partially compatible with each other in terms of low-temperature fixability and hot offset resistance. Therefore, it is preferable that the unmodified polyester and the urea-modified polyester have a similar composition.

  The weight ratio of unmodified polyester to urea-modified polyester is usually 20/80 to 95/5, preferably 70/30 to 95/5, more preferably 75/25 to 95/5, particularly preferably 80 /. 20-93 / 7. When the weight ratio of the urea-modified polyester is less than 5%, the hot offset resistance is deteriorated, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

  The glass transition point (Tg) of the binder resin containing unmodified polyester and urea-modified polyester is usually 45 to 65 ° C, preferably 45 to 60 ° C. If it is less than 45 ° C., the heat resistance of the toner deteriorates, and if it exceeds 65 ° C., the low-temperature fixability becomes insufficient.

  In addition, since the urea-modified polyester is likely to be present on the surface of the obtained toner base particles, the heat-resistant storage stability tends to be good even when the glass transition point is low as compared with known polyester-based toners.

<Colorant>
As the colorant, all known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher , Yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Vulcan fast yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Phi Sayred, Parachlor Ortonito Aniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmin Min BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R , Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thio Indigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red Polyazo Red, Chrome Vermillion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), indigo, ultramarine blue, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Lid Russian nin green, anthraquinone green, titanium oxide, zinc white, litbon and mixtures thereof can be used.

  The content of the colorant is usually 1 to 15% by weight, preferably 3 to 10% by weight, based on the toner.

  The colorant can also be used as a master batch combined with a resin. As a binder resin to be kneaded with the production of the master batch or with the master batch, a polymer of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyl toluene or the like, or a copolymer of these and a vinyl compound, Polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, fat Aromatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, paraffin waxes and the like can be mentioned, and these can be used alone or in combination.

<Charge control agent>
The toner of the present invention can contain a charge control agent as required. Known charge control agents can be used, such as nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified 4 Secondary ammonium salt or compound, tungsten simple substance or compound, fluorine-based activator, salicylic acid metal salt, metal salt of salicylic acid derivative, and the like. Specifically, Bontron 03 of a nigrosine dye, Bontron P-51 of a quaternary ammonium salt, Bontron S-34 of a metal-containing azo dye, E-82 of an oxynaphthoic acid metal complex, E-84 of a salicylic acid metal complex , Phenolic condensate E-89 (above, Orient Chemical Industries, Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, Hodogaya Chemical Co., Ltd.), quaternary ammonium salt copy Charge PSY VP2038, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (Nippon Carlit) Manufactured), copper phthalocyanine, perylene, quinacridone, azo series Fee, a sulfonic acid group, a carboxyl group, and polymer compounds having a functional group such as quaternary ammonium salts. Of these, substances that control the negative polarity of the toner are particularly preferably used.

  The amount of charge control agent used is determined by the type of binder resin, the presence or absence of additives used as necessary, and the toner production method including the dispersion method, and is not uniquely limited. Preferably, it is used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the charge control agent is reduced, the electrostatic attraction with the developing roller is increased, the developer fluidity is lowered, and the image density is lowered. Invite.

<Release agent>
The toner of the present invention can contain a release agent as necessary. As a release agent, a low melting point wax having a melting point of 50 to 120 ° C. works more effectively as a release agent in the dispersion with the binder resin between the fixing roller and the toner interface. The effect on high temperature offset is exhibited without applying a release agent such as oil. Examples of such a wax component include the following. Examples of waxes and waxes include plant waxes such as carnauba wax, cotton wax, wood wax and rice wax, animal waxes such as beeswax and lanolin, mineral waxes such as ozokerite and cercin, and paraffin, microcrystalline and petrolatum. And petroleum wax. In addition to these natural waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax and polyethylene wax, and synthetic waxes such as esters, ketones, and ethers can be used. Furthermore, fatty acid amides such as 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide, chlorinated hydrocarbon, and low molecular weight crystalline polymer resin, poly-n-stearyl methacrylate, poly-n- A crystalline polymer having a long alkyl group in the side chain such as a homopolymer or copolymer of polyacrylate such as lauryl methacrylate (for example, a copolymer of n-stearyl acrylate-ethyl methacrylate, etc.) can also be used. .

  The amount of the release agent used is determined by the type of binder resin, the presence or absence of additives used as necessary, and the toner production method including the dispersion method, but is not uniquely limited. The amount is preferably in the range of 1 to 15 parts by weight and more preferably in the range of 3 to 10 parts by weight with respect to 100 parts by weight of the binder resin.

  The charge control agent and the release agent can be melt-kneaded together with the master batch and the binder resin, and of course, they may be added when dissolved and dispersed in the organic solvent.

<Toner production method>
Next, a toner manufacturing method will be described. Here, although it shows about a preferable manufacturing method, it is not limited to this.

1) A toner material solution is prepared by dispersing a colorant, unmodified polyester, a polyester prepolymer having an isocyanate group, and a release agent in an organic solvent.
The organic solvent is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal after toner base particle formation. Specifically, toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, Methyl isobutyl ketone and the like can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform and carbon tetrachloride are preferred. The usage-amount of an organic solvent is 0-300 weight part normally with respect to 100 weight part of polyester prepolymers, Preferably it is 0-100 weight part, More preferably, it is 25-70 weight part.

  2) The toner material liquid is emulsified in an aqueous medium in the presence of a surfactant and resin fine particles. The aqueous medium may be water alone or an organic solvent such as alcohol (methanol, isopropyl alcohol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.). It may be included.

  The amount of the aqueous medium used relative to 100 parts by weight of the toner material liquid is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight. If the amount is less than 50 parts by weight, the dispersion state of the toner material liquid is poor, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 2000 parts by weight, it is not economical.

  Further, in order to improve the dispersion in the aqueous medium, a dispersant such as a surfactant and resin fine particles is appropriately added.

  As surfactants, anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt types such as imidazoline, Quaternary ammonium salt type cationic surfactants such as alkyltrimethylammonium salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, pyridinium salt, alkylisoquinolinium salt, benzethonium chloride, fatty acid amide derivative, polyhydric alcohol Nonionic surfactants such as derivatives, for example, amphoteric surfactants such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl-N, N-dimethylammonium betaine And the like.

  Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount. Preferred anionic surfactants having a fluoroalkyl group include fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [ω-fluoroalkyl (C6-C11 ) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [ω-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carvone Acids and metal salts, perfluoroalkylcarboxylic acids (C7 to C13) and metal salts thereof, perfluoroalkyl (C4 to C12) sulfonic acids and metal salts thereof, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- ( 2-Hydroxyethyl) Perful Olooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. Can be mentioned.

  Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101. DS-102 (manufactured by Daikin Industries, Ltd.), Megafac F-110, F-120, F-113, F-191, F-812, F-833 (manufactured by Dainippon Ink, Inc.), Xtop EF-102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fgentent F-100, F150 (manufactured by Neos).

  In addition, examples of the cationic surfactant include aliphatic quaternary ammonium salts such as aliphatic primary, secondary or secondary amine acids having a fluoroalkyl group, and perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salts. , Benzalkonium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (manufactured by Asahi Glass), Florard FC-135 (manufactured by Sumitomo 3M), Unidyne DS-202 (Daikin Industries) Manufactured), MegaFuck F-150, F-824 (Dainippon Ink Co., Ltd.), Xtop EF-132 (Tochem Products), Footgent F-300 (Neos), and the like.

  The resin fine particles are added to stabilize the toner base particles formed in the aqueous medium. For this reason, it is preferable to add so that the coverage existing on the surface of the toner base particles is in the range of 10 to 90%. For example, polymethyl methacrylate fine particles 1 μm and 3 μm, polystyrene fine particles 0.5 μm and 2 μm, poly (styrene-acrylonitrile) fine particles 1 μm, trade names are PB-200H (manufactured by Kao), SGP (manufactured by Soken Co., Ltd.), Technopolymer There are SB (manufactured by Sekisui Chemical Co., Ltd.), SGP-3G (manufactured by Sokensha), Micropearl (manufactured by Sekisui Fine Chemical Co., Ltd.) and the like.

  In addition, inorganic compound dispersants such as tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, and hydroxyapatite can also be used.

  As a dispersant that can be used in combination with the above resin fine particles and inorganic compound dispersant, the dispersed droplets may be stabilized by a polymer protective colloid. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride and other (meth) acrylic monomers containing hydroxyl groups Bodies such as acrylic acid-β-hydroxyethyl, methacrylic acid-β-hydroxyethyl, acrylic acid-β-hydroxypropyl, methacrylic acid-β-hydroxypropyl, acrylic acid-γ-hydroxypropyl, methacrylic acid-γ-hydroxy Propyl, acrylic acid-3-chloro-2-hydroxypropyl, methacrylic acid-3-chloro-2-hydroxypropyl, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate Acid esters, N-methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, or compounds containing vinyl alcohol and a carboxyl group Esters such as vinyl acetate, vinyl propionate, vinyl butyrate, acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, vinyl pyridine, vinyl pyrrolidone, vinyl imidazole , Nitrogen-containing compounds such as ethyleneimine, or homopolymers or copolymers such as those having a heterocyclic ring thereof, polyoxyethylene, polyoxypro Len, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxyethylene Polyoxyethylenes such as nonylphenyl ester, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.

  The dispersion method is not particularly limited, and known equipment such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, and an ultrasonic wave can be applied. Among these, the high-speed shearing method is preferable in order to make the particle size of the dispersion 2 to 20 μm. When a high-speed shearing disperser is used, the rotational speed is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 40 to 98 ° C.

3) At the same time as the preparation of the emulsion, the amines (B) are added to cause a reaction with the polyester prepolymer (A) having an isocyanate group.
This reaction involves molecular chain crosslinking and / or elongation. The reaction time is selected depending on the reactivity between the isocyanate group structure of the polyester prepolymer (A) and the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 24 hours. The reaction temperature is generally 0 to 150 ° C, preferably 40 to 98 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.

  4) After completion of the reaction, the organic solvent is removed from the emulsified dispersion (reactant), washed and dried to obtain toner base particles.

  In order to remove the organic solvent, the temperature of the entire system is gradually raised in a laminar stirring state, and after applying strong stirring in a certain temperature range, the solvent-based toner base particles can be produced by removing the solvent. . Further, when an acid such as calcium phosphate salt or an alkali-soluble material is used as the dispersion stabilizer, the calcium phosphate salt is dissolved from the toner base particles by a method such as dissolving the calcium phosphate salt with an acid such as hydrochloric acid and washing with water. Remove. It can also be removed by operations such as enzymatic degradation.

5) A charge control agent is injected into the toner base particles obtained above, and then inorganic fine particles such as silica fine particles and titanium oxide fine particles are externally added to obtain a toner.
The injection of the charge control agent and the external addition of the inorganic fine particles are performed by a known method using a mixer or the like.

  Thereby, a toner having a small particle size and a sharp particle size distribution can be easily obtained. Furthermore, by applying strong agitation in the process of removing the organic solvent, it is possible to control the shape between a true spherical shape and a rugby ball shape, and the surface morphology is also controlled between a smooth shape and an umeboshi shape. be able to.

Hereinafter, further preferable points in the image forming method of the present invention will be described.
[1] First, in the toner used in the image forming method of the present invention, the BET specific surface area of the external additive contained per unit weight of the toner is 0.5 to 3.5 (m ² / g). It is preferable.
In general, if an external additive is not added, it is difficult to use the toner as an image forming apparatus. On the other hand, if an external additive is added too much, a problem may occur in the image forming apparatus. Therefore, the BET specific surface area of the external additive contained per toner unit weight needs to be within the above range. Adjustment to this range can be performed by changing the amount to be added according to the BET specific surface area value of the external additive to be used.

[2] Next, the charging means used in the image forming method of the present invention is not particularly limited, but a charging means using corona discharge is desirable.
Conventional charging means using corona discharge include a corotron charger and a scorotron charger. In the present invention, either of these chargers may be used. However, in terms of uniform chargeability to the image carrier, the surface of the image carrier can be uniformly charged by using a scorotron charger, and the frequency of occurrence of abnormal images can be reduced. Therefore, it is desirable to use a scorotron charger as the charger.

[3] The toner used in the image forming method of the present invention has a ratio (Dv / Dn) of volume average particle diameter (Dv) to number average particle diameter (Dn) in the range of 1.00 to 1.40. Preferably there is.
The volume average particle diameter Dv is preferably 3.0 to 7.0 μm. In general, it is said that the smaller the particle size of the toner, the more advantageous it is to obtain a high-resolution and high-quality image, but it is disadvantageous for transferability and cleaning properties. is there. Further, when the volume average particle diameter is smaller than the above range, in the case of a two-component developer, the toner is fused to the surface of the carrier during a long period of stirring in the developing device, and the charging ability of the carrier is reduced. When used, toner filming on the developing roller and toner fusion to a blade for thinning the toner are easily generated.

  If Dv / Dn is within such a range, high-resolution and high-quality toner can be obtained. Furthermore, in the case of a two-component developer, even if the toner balance is maintained over a long period of time, fluctuations in the particle size of the toner in the developer are reduced, and good and stable developability even during long-term agitation in the developing device. Enable. If Dv / Dn exceeds 1.40, the variation in particle size of individual toner particles is large, and the behavior of the toner varies during development, etc., and the reproducibility of minute dots is impaired, resulting in high quality. Correct images cannot be obtained. Dv / Dn is more preferably in the range of 1.00 to 1.20, and a better image can be obtained.

<Measuring method of particle size distribution>
As an apparatus for measuring the particle size distribution of toner particles by the Coulter Counter method, there are Coulter Counter TA-II, Coulter Multisizer II, and Multisizer III (all manufactured by Coulter, Inc.).
First, 0.1 to 5 ml of a surfactant (preferably Na salt of alkylbenzene sulfonic acid) is added as a dispersant to 100 to 150 ml of an aqueous electrolytic solution. Here, the electrolytic solution is a solution prepared by preparing a 1% NaCl aqueous solution using primary sodium chloride. For example, ISOTON-II (manufactured by Coulter) can be used. Here, 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes. Volume distribution and number distribution are calculated. From the obtained distribution, the weight average particle diameter (D4) and the number average particle diameter of the toner can be obtained.

  As channels, 2.00 to less than 2.52 μm; 2.52 to less than 3.17 μm; 3.17 to less than 4.00 μm; 4.00 to less than 5.04 μm; 5.04 to less than 6.35 μm; 6 Less than 35 to 8.00 μm; less than 8.00 to less than 10.08 μm; less than 10.08 to less than 12.70 μm; less than 12.70 to less than 16.00 μm; less than 16.00 to less than 20.20 μm; Uses 13 channels of less than 40 μm; 25.40 to less than 32.00 μm; 32.00 to less than 40.30 μm, and targets particles having a particle size of 2.00 μm to less than 40.30 μm.

[4] The toner used in the image forming method of the present invention preferably contains 1 to 10% by number of particles of 2 μm or less. The defect due to the particle size is greatly related to the content of fine powder. In particular, when the particle size of 2 μm or less exceeds 10%, it becomes an obstacle when the adhesion to the carrier or the charging stability at a high level is achieved. Conversely, when the toner particle size is larger than the above range, it becomes difficult to obtain a high-resolution and high-quality image, and the toner particle size when the balance of the toner in the developer is performed. In many cases, fluctuations of It was also clarified that the same applies when Dv / Dn is greater than 1.40. Therefore, it is desirable that 1 to 10% by number of particles of 2 μm or less.

<Method for measuring particle size of 2 μm or less>
The particle ratio of 2 μm or less and the circularity of the toner can be measured by a flow type particle image analyzer FPIA-2000 (manufactured by Toa Medical Electronics Co., Ltd.). As a specific measuring method, 0.1 to 0.5 ml of a surfactant, preferably alkylbenzene sulfonate is added as a dispersant to 100 to 150 ml of water from which impure solids have been removed in advance, and further measurement is performed. Add about 0.1-0.5g of sample. The suspension in which the sample is dispersed is obtained by performing dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and measuring the shape and distribution of the toner with the above apparatus at a dispersion concentration of 3000 to 10,000 / μl. .

[5] The toner used in the image forming method of the present invention is obtained by externally adding fine particles having an average primary particle size of 50 to 500 nm and a bulk density of 0.3 g / cm ³ or more to the surface of the toner base particles. The obtained toner is preferable.
By using such fine particles as an external additive, the cleaning property is improved, and particularly when a small particle size toner capable of obtaining high image quality is used, improvement in the developability and transferability is improved. Can do.

  In addition, the improvement in cleaning property facilitates removal of the discharge product and the toner adsorbing the deteriorated lubricant from the surface of the image carrier. Further, by removing the discharge products and the deteriorated lubricant, it is possible to have a margin for the occurrence of abnormal images such as image flow.

  When the average primary particle size is less than 50 nm, the fine particles may be buried in the concave and convex portions on the toner surface to lower the role of the rollers. On the other hand, when the particle size is larger than 500 μm, when the fine particles are positioned between the blade and the surface of the photosensitive member, the order of the toner is the same level as the contact area of the toner itself, and the toner particles to be cleaned are passed, that is, defective cleaning occurs. It becomes easy.

When the bulk density is less than 0.3 mg / cm ³ , although there is a contribution to the improvement of fluidity, the scattering property and adhesion of the toner and fine particles are increased, so that the effect as a roller and accumulation in the cleaning unit, The so-called dam effect that prevents toner cleaning failure is reduced.

Examples of the inorganic compound in the fine particles include SiO ₂ , TiO ₂ , Al ₂ O ₃ , MgO, CuO, ZnO, SnO ₂ , CeO ₂ , Fe ₂ O ₃ , BaO, CaO, K ₂ O, Na ₂ O, and ZrO _{2. , CaO · SiO 2, K 2} O (TiO 2) n, Al 2 O 3 · 2SiO 2, CaCO 3, MgCO 3, BaSO 4, MgSO 4, can be exemplified SrTiO ₃ or the like, preferably, SiO ₂ , TiO ₂ , and Al ₂ O ₃ . In particular, these inorganic compounds may be hydrophobized with various coupling agents, hexamethyldisilazane, dimethyldichlorosilane, octyltrimethoxysilane, and the like.

  The organic compound fine particles may be a thermoplastic resin or a thermosetting resin. For example, vinyl resin, polyurethane resin, epoxy resin, polyester resin, polyamide resin, polyimide resin, silicon resin, phenol resin, melamine resin, Examples include urea resins, aniline resins, ionomer resins, and polycarbonate resins. As the resin fine particles, two or more of the above resins may be used in combination. Of these, vinyl resins, polyurethane resins, epoxy resins, polyester resins, and combinations thereof are preferred because an aqueous dispersion of fine spherical resin particles is easily obtained.

  Specific examples of vinyl resins include polymers obtained by homopolymerization or copolymerization of vinyl monomers, such as styrene- (meth) acrylic acid ester copolymers, styrene-butadiene copolymers, (meth) acrylic acid. -Acrylic ester copolymer, styrene-acrylonitrile copolymer, styrene-maleic anhydride copolymer, styrene- (meth) acrylic acid copolymer, and the like.

The bulk density of the fine particles was measured by the following method.
Using a 100 ml graduated cylinder, fine particles were gradually added to make 100 ml. At that time, no vibration was applied. The bulk density was measured by the difference in weight before and after placing the fine particles of the graduated cylinder. Formula (3) was used for calculation of the bulk density.

[Equation 3]
Formula (3)
Bulk density (g / cm ³ ) = fine particle amount (g / 100 ml) ÷ 100

  As a method of adding and attaching the fine particles to the toner surface, the toner base particles and the fine particles are mechanically mixed and attached using various known mixing devices, or the toner base particles and the fine particles in the liquid phase. There is a method of uniformly dispersing with a surfactant or the like, and drying after adhering treatment.

[6] The image carrier used in the image forming method of the present invention is preferably an organic photoreceptor having a filler dispersed in the surface layer.
By using an organic photoreceptor having a filler dispersed in the surface layer of the image carrier, the life of the image carrier can be further extended. By using the image carrier having improved wear resistance in this way, the surface of the image carrier can be easily kept flat. For this reason, the toner is not trapped by fine irregularities on the surface, and thus the cleaning property is easily maintained. Further, since it is easy to maintain the cleaning property, the toner adsorbing the discharge product and the deteriorated lubricant is easily removed from the surface of the image carrier, and as a result, the discharge product and the deteriorated lubricant from the surface of the image carrier. Is easily removed. Thereby, it is possible to have a margin for the occurrence of an abnormal image such as an image flow.

  A photoreceptor in which a filler is dispersed in the surface layer is, for example, a photoreceptor in which a filler is added to the protective layer for the purpose of improving wear resistance. Examples of organic fillers include fluororesin powders such as polytetrafluoroethylene, silicone resin powders, and a-carbon powders. Inorganic fillers include metal powders such as copper, tin, aluminum, and indium, tin oxide, and oxidation. Examples thereof include zinc, titanium oxide, indium oxide, antimony oxide, bismuth oxide, tin oxide doped with antimony, metal oxides such as tin-doped indium oxide, and inorganic materials such as potassium titanate. These fillers may be used alone or in combination of two or more. Further, these fillers can be dispersed by using an appropriate disperser for the protective layer coating solution. Moreover, it is preferable from the point of the transmittance | permeability of a protective layer that the average particle diameter of a filler is 0.5 micrometer or less, Preferably it is 0.2 micrometer or less. Moreover, you may add a plasticizer and a leveling agent in a protective layer.

[7] The image carrier used in the image forming method of the present invention is preferably an organic photoreceptor having a protective layer using a cross-linked charge transport material.
As the binder composition of the protective layer, a binder having a crosslinked structure is effectively used. Regarding the formation of a cross-linked structure, a reactive monomer having a plurality of cross-linkable functional groups in one molecule is used to cause a cross-linking reaction using light or heat energy to form a three-dimensional network structure. is there. This network structure functions as a binder resin and exhibits high wear resistance.

  From the viewpoint of electrical stability, printing durability, and life, it is a very effective means to use a monomer having a charge transporting ability in whole or in part as the reactive monomer. By using such a monomer, a charge transporting site is formed in the network structure, and the function as a protective layer can be sufficiently expressed.

  As the reactive monomer having charge transporting ability, a compound containing at least one charge transporting component and a silicon atom having a hydrolyzable substituent in the same molecule, and a charge transporting component in the same molecule A compound containing a hydroxyl group, a compound containing a charge transporting component and a carboxyl group in the same molecule, a compound containing a charge transporting component and an epoxy group in the same molecule, a charge transporting component in the same molecule And a compound containing an isocyanate group. These charge transport materials having a reactive group may be used alone or in combination of two or more.

  More preferably, a reactive monomer having a triarylamine structure is effectively used as the monomer having a charge transporting ability because of its high electrical and chemical stability and fast carrier mobility.

  In addition to this, monofunctional and bifunctional polymerizable monomers and polymerizable oligomers are used in combination for the purpose of viscosity adjustment during coating, stress relaxation of the cross-linked charge transport layer, low surface energy, and reduction of friction coefficient. be able to. As these polymerizable monomers and oligomers, known ones can be used.

  In addition, the hole transporting compound is polymerized or cross-linked using heat or light. When the polymerization reaction is carried out by heat, the polymerization reaction proceeds only with thermal energy and the case where a polymerization initiator is required. However, in order to advance the reaction efficiently at a lower temperature, it is preferable to add an initiator.

  In the case of polymerization by light, it is preferable to use ultraviolet light as light, but the reaction rarely proceeds only by light energy, and generally a photopolymerization initiator is used in combination. The polymerization initiator in this case mainly absorbs ultraviolet rays having a wavelength of 400 nm or less, generates active species such as radicals and ions, and starts polymerization. In the present invention, the aforementioned heat and photopolymerization initiators can be used in combination.

  The charge transport layer having a network structure formed in this manner has high wear resistance, but has a large volume shrinkage during the crosslinking reaction, and if it is too thick, it may cause cracks. In such a case, the protective layer may be a laminated structure, a low molecular dispersion polymer protective layer may be used for the lower layer (photosensitive layer side), and a protective layer having a crosslinked structure may be formed on the upper layer (surface side). good.

An example of the preparation of a crosslinking type protective layer coating solution and the film thickness and production conditions of the protective layer are shown.
30 parts by weight of a hole transporting compound (the following structural formula 1), 0.6 parts by weight of an acrylic monomer (the following structural formula 2) and a photopolymerization initiator (1-hydroxy-cyclohexyl-phenyl-ketone), and monochlorobenzene 50 It was dissolved in a mixed solvent of parts by weight / 50 parts by weight of dichloromethane to prepare a coating material for the surface protective layer. This paint was applied on the previous charge transport layer by spray coating, and cured for 30 seconds with a light intensity of 500 mW / cm ² using a metal halide lamp to form a surface protective layer having a thickness of 5 μm.

[8] The image bearing member used in the image forming method of the present invention may be an amorphous silicon photosensitive member.
As an electrophotographic photoreceptor used in the present invention, a conductive support is heated to 50 ° C. to 400 ° C., and a vacuum deposition method, a sputtering method, an ion plating method, a thermal CVD method, a photo CVD is applied on the support. An amorphous silicon photoconductor (hereinafter referred to as “a-Si photoconductor”) having a photoconductive layer made of a-Si can be used by a film forming method such as a plasma CVD method. Among them, a plasma CVD method, that is, a method in which a source gas is decomposed by direct current, high frequency or microwave glow discharge to form an a-Si deposited film on a support is preferably used.

The layer structure of the amorphous silicon photoconductor is, for example, as follows.
FIG. 10 is a schematic configuration diagram for explaining a layer configuration. In the electrophotographic photoreceptor 500 shown in FIG. 10A, a photoconductive layer 502 made of a-Si: H, X and having photoconductivity is provided on a support 501.
An electrophotographic photoreceptor 500 shown in FIG. 10B includes a photoconductive layer 502 made of a-Si: H, X and having photoconductivity, and an amorphous silicon surface layer 503 on a support 501. It is configured.
An electrophotographic photoreceptor 500 shown in FIG. 10C has a photoconductive layer 502 made of a-Si: H, X and having photoconductivity on a support 501, an amorphous silicon surface layer 503, and And an amorphous silicon based charge injection blocking layer 504.
In the electrophotographic photoreceptor 500 shown in FIG. 10D, a photoconductive layer 502 is provided on a support 501. The photoconductive layer 502 includes a charge generation layer 505 made of a-Si: H, X and a charge transport layer 506, and an amorphous silicon-based surface layer 503 is provided thereon.

The support for the photoreceptor may be conductive or electrically insulating. Examples of the conductive support include metals such as Al, Cr, Mo, Au, In, Nb, Te, V, Ti, Pt, Pd, and Fe, and alloys thereof such as stainless steel. Also, at least the surface on the side where the photosensitive layer is to be formed of an electrically insulating support such as polyester, polyethylene, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polystyrene, polyamide or other synthetic resin film or sheet, glass or ceramic. A conductively treated support can also be used.
The shape of the support can be a cylindrical or plate-like or endless belt with a smooth or uneven surface, and the thickness thereof is appropriately determined so that a desired photoreceptor for an image forming apparatus can be formed. When flexibility as a photoreceptor for an image forming apparatus is required, it can be made as thin as possible within a range where the function as a support can be sufficiently exhibited. However, the support is usually 10 μm or more from the viewpoint of production and handling, such as mechanical strength.

<Injection prevention layer>
The amorphous silicon photosensitive member that can be used in the present invention includes a charge injection blocking layer that functions to prevent charge injection from the conductive support side between the conductive support and the photoconductive layer, if necessary. It is more effective to provide (FIG. 10 (c)). That is, the charge injection blocking layer has a function of blocking charge injection from the support side to the photoconductive layer side when the photosensitive layer is subjected to a charging process with a certain polarity on its free surface. When charged, it has a so-called polarity dependency that does not exhibit such a function. In order to provide such a function, the charge injection blocking layer contains a relatively large number of atoms for controlling conductivity as compared with the photoconductive layer. The layer thickness of the charge injection blocking layer is preferably from 0.1 to 5 μm, more preferably from 0.3 to 4 μm, and most preferably from 0.5 to 0.5 in view of obtaining desired electrophotographic characteristics and economic effects. It is desirable to be 3 μm.

<Photoconductive layer>
The photoconductive layer is formed on the undercoat layer as necessary, and the layer thickness of the photoconductive layer 502 is appropriately determined as desired from the viewpoint of obtaining desired electrophotographic characteristics and economic effects, preferably It is desirable that the thickness is 1 to 100 μm, more preferably 20 to 50 μm, and most preferably 23 to 45 μm.

<Charge transport layer>
The charge transport layer is a layer mainly having a function of transporting charges when the photoconductive layer is functionally separated. The charge transport layer includes at least silicon atoms, carbon atoms, and fluorine atoms as constituent elements, and is formed of a-SiC (H, F, O) including hydrogen atoms and oxygen atoms as required. Conductive properties, especially charge retention properties, charge generation properties, and charge transport properties.
In the present invention, it is particularly preferable to contain an oxygen atom.
The layer thickness of the charge transport layer is appropriately determined as desired from the viewpoint of obtaining desired electrophotographic characteristics and economic effects. The charge transport layer is preferably 5 to 50 μm, more preferably 10 to 40 μm, Optimally, the thickness is desirably 20 to 30 μm.

<Charge generation layer>
The charge generation layer is a layer mainly having a function of generating charges when the photoconductive layer is functionally separated. This charge generation layer is composed of a-Si: H containing at least silicon atoms as components and substantially no carbon atoms and, if necessary, hydrogen atoms, and has desired photoconductive properties, particularly charge generation properties. , Has charge transport properties.
The layer thickness of the charge generation layer is appropriately determined as desired from the viewpoints of obtaining desired electrophotographic characteristics and economic effects, etc., preferably 0.5 to 15 μm, more preferably 1 to 10 μm, optimally 1 ˜5 μm.

<Surface layer>
If necessary, the amorphous silicon photoreceptor that can be used in the present invention can be provided with a surface layer on the photoconductive layer formed on the support as described above. It is preferable to form a surface layer. This surface layer has a free surface, and is provided to achieve the object of the present invention mainly in moisture resistance, continuous repeated use characteristics, electrical pressure resistance, use environment characteristics, and durability.
The thickness of the surface layer is usually 0.01 to 3 μm, preferably 0.05 to 2 μm, and most preferably 0.1 to 1 μm. If the layer thickness is less than 0.01 μm, the surface layer is lost due to wear or the like during use of the photoreceptor, and if it exceeds 3 μm, electrophotographic characteristics such as an increase in residual potential are observed.

[9] An image forming apparatus in which the image forming method of the present invention is implemented is provided.
In the image forming method of the present invention, the image forming area on the surface of the image carrier is uniformly charged by the charging means, the latent image is formed by writing on the image carrier by the exposure means, and the latent image is rubbed by the developing means. An image is formed by developing with charged toner. As the toner, the above water-based granulated toner is used. Next, the image on the image carrier is transferred directly to the recording paper conveyed from the paper feeding means by the transfer means or indirectly via the intermediate transfer body, and then the image is fixed to the recording paper by the fixing means. .

  On the other hand, the untransferred toner remaining on the image carrier without being completely transferred is scraped off from the image carrier by the cleaning means, and the image carrier is formed in a cylindrical shape or a belt shape. After the formation process, the next image formation process is started as it is.

  In the image forming apparatus of the present invention, the lubricant is applied to the image carrier by the lubricant applying means. The lubricant application position may be on either the upstream side or the downstream side of the cleaning unit as long as it is downstream of the transfer unit and upstream of the charging unit. However, if it is difficult to uniformly apply the lubricant to the image carrier for reasons such as process speed, the lubricant may be applied downstream of the cleaning means and upstream of the charging means. desirable. In addition, an image forming apparatus that improves the efficiency of applying the lubricant to the image carrier by providing a lubricant leveling unit may be used.

  An image forming apparatus comprising such a process has a revolver system that has only one image carrier and forms an image for each color with the image carrier, and a tandem system that uses one image carrier for each color. .

Moreover, the following are used as each means.
First, as the charging unit, as described above, a roller system is an example of a charging unit (charging unit using proximity discharge) by discharging in a minute gap between the charging unit and the image carrier. Further, as an example of a charging method that does not perform charge transfer due to discharge between the charging means and the image carrier, there is a corona charging method, and examples of a charger using the corona charging method include a corotron charger and a scorotron charger. There is.

  As the exposure means, an exposure method using an LD, an LED lamp, or a xenon lamp can be used.

  The developing means is a developing method using a one-component developing means or a two-component developing means for mixing and developing toner and a carrier, and the toner used is the above-mentioned water-based granulated toner.

  As the transfer means, a transfer method using a transfer belt, a transfer charger, and a transfer roller can be used.

Examples of the cleaning means include a blade-shaped cleaning blade made of polyurethane rubber, silicone rubber, nitrile rubber, chloroprene rubber, or the like. A plurality of cleaning means may be mounted. At this time, as the shape of the cleaning blade, a blade having an obtuse angle (90 ° to 180 °) at the tip of the blade edge that contacts the image carrier may be used when contacting with the counter. By adopting such a blade shape, the blade contact pressure to the image carrier can be increased, and the cleaning property can be improved. In addition, a method of electrostatically cleaning the toner on the surface of the image carrier by applying a voltage to such a cleaning unit may be used in combination. The contact of the cleaning blade to the image carrier may be trailing or counter with respect to the rotation direction of the image carrier.

  When the cleaning of the toner on the image carrier is insufficient with only the cleaning means, a cleaning auxiliary means is mounted to improve the cleaning performance. Examples of the cleaning auxiliary means include a fur brush, an elastic roller, a tube covering roller, and a nonwoven fabric. A plurality of these may be mounted. At this time, a cleaning property may be improved by applying a voltage to the cleaning assisting means to control the polarity of the toner. Moreover, you may use the loop brush comprised so that a bristle tip might become a loop shape.

  As the lubricant application means, a method of applying a lubricant to the image carrier with a fur brush, a loop brush, a roller, or a belt, or a method of directly applying a solid lubricant or lubricant powder to the image carrier may be used. . Moreover, you may use the loop brush comprised so that a bristle tip might become a loop shape.

  Lubricants include fatty acid salts with lamellar crystal structures such as powdered, solid, and film-like fluororesins (polytetrafluoroethylene, polyvinylidene fluoride, etc.), zinc stearate, magnesium stearate, and calcium stearate. Metals (other than lauroyl lysine, monocetyl phosphate sodium zinc salt, lauroyl taurine calcium), liquid materials such as silicone oil, fluorine oil, natural wax, synthetic wax, and gaseous materials are used as external additives. Things.

When the lubricant to be used is a fatty acid metal salt, it is desirable that an amount of lubricant specified as follows be applied to the image carrier.
That is, in the charged area of the image carrier by the charging means, the element ratio [%] of the metal element contained in the fatty acid metal salt present on the surface of the image carrier is measured by an X-ray photoelectron spectrometer (XPS) as follows: It is desirable to apply the lubricant to the image carrier so that the ratio is equal to or greater than the ratio calculated in (4).

[Equation 4]
Formula (4)
1.52 × 10−4 × {Vpp−2 × Vth} × f / v
(Where Vpp is the amplitude [V] of the AC component applied to the charging means, f is the frequency [Hz] of the AC component applied to the charging means, and v is the moving speed [mm] of the image carrier surface facing the charging means. / Sec], Vth is the discharge start voltage, and the value of Vth is d [μm] for the film thickness of the image carrier, Gp for the closest distance [μm] between the charging means surface and the surface of the image carrier. When the relative dielectric constant of the carrier is εopc and the relative dielectric constant in the space between the image carrier and the charging means is εair, Vth = 312 + 6.2 × (d / εopc + Gp / εair) + √ (7737.6 × d / Εopc))

  Examples of the lubricant leveling means include blade-shaped lubricant leveling means made of polyurethane rubber, silicone rubber, nitrile rubber, chloroprene rubber or the like. At this time, the shape of the lubricant leveling blade may be a blade having an obtuse angle (90 ° to 180 °) at the tip of the blade edge that comes into contact with the image carrier when contacting with the counter. By adopting such a blade shape, the blade contact pressure to the image carrier can be increased, and the lubricant leveling efficiency can be improved. Further, a method of electrostatically cleaning the toner passing through the cleaning means from the surface of the image carrier by applying a voltage to the lubricant leveling means may be used. The contact of the lubricant leveling blade to the image carrier may be trailing or counter with respect to the rotation direction of the image carrier.

1 to 7 and 13 each illustrate an image forming apparatus to which the image forming method of the present invention is applied.
FIG. 1 shows corona charging means (1), exposure means (2), developing means (3), transfer means (4) in the rotational direction of a cylindrical image carrier (8) made of an electrophotographic photosensitive member, The image forming apparatus includes a lubricant application unit (6) having a lubricant (5) and a cleaning unit (7).
FIG. 2 shows an image forming apparatus in which the cleaning means (7) is arranged next to the transfer means (4), and the lubricant application means (6) having the lubricant (5) is arranged next.
FIG. 3 also shows that the brush-like cleaning auxiliary means (11) is arranged next to the transfer means (4), and then the cleaning means (7) and the lubricant applying means (6) having the lubricant (5). The image forming apparatuses are arranged in order.
4 shows that the transfer means (4), the cleaning means (7), and the lubricant application means (6) having the lubricant (5) are arranged in this order, and then the lubricant leveling means (12). An image forming apparatus provided with (counter contact).
Further, FIG. 5 shows that the transfer means (4) is followed by a brush-like cleaning auxiliary means (11), then the cleaning means (7), the lubricant application means (6) having the lubricant (5), The image forming apparatus is arranged in the order of lubricant leveling means (12) (counter contact).
FIG. 6 also shows the transfer means (4), the cleaning means (7), the lubricant application means (6) having the lubricant (5), the lubricant leveling means (12) (trailing contact). The image forming apparatuses are arranged in this order.
FIG. 7 shows an image forming apparatus having a transfer unit (4), a cleaning auxiliary unit (6), a cleaning unit, a lubricant applying unit, a lubricant, and a lubricant leveling unit (trailing contact). is there.
FIG. 13 shows an image forming apparatus having charging means (1) by proximity discharge in the charging means.
The above-described examples are revolver type image forming apparatuses, but of course, a tandem type may be used.
The example shown in FIGS. 1 to 7 is a corona charging unit as an example of a charging method in which the charging unit does not perform charge transfer by discharging between the charging unit and the image carrier, but between the charging unit and the image carrier. It may be a charging means by discharging in a minute gap (charging means by proximity discharge).

[10] As shown in FIG. 8, the image forming apparatus integrally includes an image carrier (8) and at least one means selected from a charging means (1), a developing means (3), and a cleaning means (7). It is also possible to have a configuration in which a process cartridge that is supported and detachable from the main body of the image forming apparatus is loaded, and it is desirable to replace the entire process cartridge during maintenance.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. In addition, this invention is not limited to the Example illustrated here. The “parts” shown below are parts by weight.

[Example 1]
(Synthesis of unmodified polyester resin)
229 parts of bisphenol A ethylene oxide 2-mole adduct, 529 parts of bisphenol A propion oxide 3-mole adduct, 208 parts of terephthalic acid, 46 parts of adipic acid and dibutyltin oxide 2 parts were added and reacted at 230 ° C. under normal pressure for 8 hours. Next, after reacting under reduced pressure of 10 to 15 mmHg for 5 hours, 44 parts of trimellitic anhydride was added to the reaction vessel and reacted at 180 ° C. for 2 hours under normal pressure to synthesize an unmodified polyester resin. .

  The obtained unmodified polyester resin had a number average molecular weight of 2500, a weight average molecular weight of 6700, a glass transition temperature of 43 ° C., and an acid value of 25 mgKOH / g.

(Preparation of masterbatch)
1200 parts of water, 540 parts of carbon black Printex 35 (manufactured by Dexa; DBP oil absorption = 42 ml / 100 mg, pH = 9.5) and 1200 parts of unmodified polyester resin were mixed using a Henschel mixer (manufactured by Mitsui Mining). . The resulting mixture was kneaded at 150 ° C. for 30 minutes using two rolls, then rolled and cooled, and pulverized with a pulverizer (manufactured by Hosokawa Micron Corporation) to prepare a master batch.

(Preparation of raw material solution)
In a reaction vessel equipped with a stirrer and a thermometer, 378 parts of unmodified polyester resin, 110 parts of carnauba wax, 22 parts of salicylic acid metal complex E-84 (manufactured by Orient Chemical Co., Ltd.) and 947 parts of ethyl acetate were charged and stirred. The temperature was raised to 80 ° C., held at 80 ° C. for 5 hours, and then cooled to 30 ° C. over 1 hour. Next, 500 parts of a master batch and 500 parts of ethyl acetate were charged into the reaction vessel and mixed for 1 hour to obtain a raw material solution.

(Preparation of wax dispersion)
1324 parts of the obtained raw material solution was transferred to a reaction vessel, and filled with 80% by volume of 0.5 mm zirconia beads using a bead mill Ultra Visco Mill (manufactured by Imex Co., Ltd.). 3 passes under the condition of 6 m / sec. I. Pigment Red and carnauba wax were dispersed to obtain a wax dispersion.

(Preparation of dispersion of toner material)
Next, 1324 parts of a 65 wt% ethyl acetate solution of unmodified polyester resin was added to the wax dispersion. A layered inorganic mineral montmorillonite (Clayton APA Southern Clay modified at least partially with a quaternary ammonium salt having a benzyl group) was added to 200 parts of the dispersion obtained by one pass using Ultraviscomyl under the same conditions as above. 3 parts) (manufactured by Products) are added. K. The mixture was stirred for 30 minutes using a homodisper (manufactured by Tokushu Kika Kogyo Co., Ltd.) to obtain a toner material dispersion.

(Synthesis of intermediate polyester resin)
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 682 parts of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, 22 parts of trimellitic anhydride And 2 parts of dibutyltin oxide were added and reacted at 230 ° C. for 8 hours under normal pressure. Next, it was made to react under reduced pressure of 10-15mHg for 5 hours, and the intermediate polyester resin was synthesize | combined. The obtained intermediate polyester resin had a number average molecular weight of 2,100, a weight average molecular weight of 9,500, a glass transition temperature of 55 ° C., an acid value of 0.5 mgKOH / g, and a hydroxyl value of 51 mgKOH / g.

(Prepolymer synthesis)
Next, 410 parts of the intermediate polyester resin, 89 parts of isophorone diisocyanate, and 500 parts of ethyl acetate are charged into a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe, and reacted at 100 ° C. for 5 hours. Was synthesized. The free isocyanate content of the obtained prepolymer was 1.53% by weight.

(Synthesis of ketimine)
In a reaction vessel equipped with a stir bar and a thermometer, 170 parts of isophoronediamine and 75 parts of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to synthesize a ketimine compound. The amine value of the obtained ketimine compound was 418 mgKOH / g.

(Preparation of oil phase mixture)
In a reaction vessel, 749 parts of a dispersion of toner material, 115 parts of a prepolymer and 2.9 parts of a ketimine compound are charged and mixed at 5,000 rpm for 1 minute using a TK homomixer (manufactured by Tokushu Kika). A mixture was obtained.

(Preparation of resin particle dispersion)
In a reaction vessel equipped with a stirring bar and a thermometer, 683 parts of water, 11 parts of reactive emulsifier (sodium salt of sulfuric acid ester of methacrylic acid ethylene oxide adduct), Eleminol RS-30 (manufactured by Sanyo Chemical Industries), styrene 83 Parts, 83 parts of methacrylic acid, 110 parts of butyl acrylate and 1 part of ammonium persulfate were stirred at 400 rpm for 15 minutes to obtain an emulsion. The emulsion was heated, heated to 75 ° C. and reacted for 5 hours. Next, 30 parts of a 1% by weight aqueous ammonium persulfate solution was added and aged at 75 ° C. for 5 hours to prepare a resin particle dispersion.

(Preparation of aqueous medium)
990 parts of water, 83 parts of resin particle dispersion, 37 parts of a 48.5% by weight aqueous solution of dodecyl diphenyl ether disulfonate, Eleminol MON-7 (manufactured by Sanyo Kasei Kogyo Co., Ltd.), 1% by weight aqueous solution of sodium carboxymethylcellulose polymer dispersant 135 parts of BS-H-3 (Daiichi Kogyo Seiyaku Co., Ltd.) and 90 parts of ethyl acetate were mixed and stirred to obtain an aqueous medium.

(Preparation of dispersion (emulsified slurry))
To 1200 parts of the aqueous medium, 867 parts of the oil phase mixed liquid was added and mixed for 20 minutes at 13000 rpm using a TK homomixer to prepare a dispersion (emulsified slurry).

  Next, the emulsified slurry was charged into a reaction vessel in which a stirrer and a thermometer were set, and after removing the solvent at 30 ° C. for 8 hours, aging was performed at 45 ° C. for 4 hours to obtain a dispersed slurry.

(Washing, drying, air sieving)
After filtering 100 parts of the dispersion slurry under reduced pressure, 100 parts of ion-exchanged water was added to the filter cake, followed by mixing at 12000 rpm for 10 minutes using a TK homomixer, followed by filtration.
To the obtained filter cake, 10 wt% hydrochloric acid was added to adjust the pH to 2.8, and the mixture was mixed at 12000 rpm for 10 minutes using a TK homomixer, followed by filtration.
Furthermore, 300 parts of ion-exchanged water was added to the obtained filter cake, mixed for 10 minutes at 12000 rpm using a TK homomixer, and then filtered twice to obtain a final filter cake.
The obtained final filter cake was dried at 45 ° C. for 48 hours using a circulating drier and sieved with a mesh having a mesh size of 75 μm to obtain toner base particles.

  To 100 parts of the obtained toner base particles, 1.0 part of hydrophobic silica as an external additive and 0.5 part of hydrophobic titanium oxide are added and mixed using a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.). Then, a toner was prepared. Table 1 shows the physical properties of the produced toner (Example A).

[Example 2]
A toner was prepared in the same manner as in Example 1 except that the amount of the modified layered inorganic mineral (trade name: Clayton APA) was changed from 3 parts to 0.1 parts. Table 1 shows the physical properties of the produced toner (Example B).

Example 3
A toner was prepared in the same manner as in Example 1 except that Clayton APA was changed to a layered inorganic mineral montmorillonite (manufactured by Kraton HY Southern Clay Products) at least partially modified with an ammonium salt having a polyoxyethylene group. Table 1 shows the physical properties of the produced toner (Example C).

Example 4
A toner was prepared in the same manner as in Example 1 except that the addition amount of Clayton APA was changed from 3 parts to 1.4 parts. Table 1 shows the physical properties of the produced toner (Example D).

Example 5
A toner was prepared in the same manner as in Example 1 except that the addition amount of Clayton APA was changed from 3 parts to 6 parts. Table 1 shows the physical properties of the produced toner (Example E).

[Comparative Example 1]
A toner was prepared in the same manner as in Example 1 except that Clayton APA was not added. Table 1 shows the physical properties of the produced toner (Comparative Example A).

[Comparative Example 2]
A toner was prepared in the same manner as in Example 1 except that the addition amount of Clayton APA was changed from 3 parts to 10 parts. As a result, the viscosity of the toner material dispersion became very high, and emulsification and dispersion were performed. The toner could not be obtained.

[Comparative Example 3]
A toner was prepared in the same manner as in Example 1 except that Clayton APA (manufactured by Southern Clay Products) was changed to an unmodified layered inorganic mineral montmorillonite (trade name: Kunipia, Kunimine Kogyo Co., Ltd.). Table 1 shows the physical properties of the resultant toner (Comparative Example B).

[Comparative Example 4]
Example 1 except that Clayton APA (manufactured by Southern Clay Products) was changed to unmodified layered inorganic mineral montmorillonite (trade name: Kunipia, Kunimine Kogyo Co., Ltd.) and the addition amount was changed from 3 parts to 1 part. A toner was prepared in the same manner as described above. The physical properties of the obtained toner (Comparative Example C) are shown in Table 1.

<Evaluation method and evaluation conditions>
For the toners of Examples A to E and Comparative Examples A and B obtained as described above, measurement of the content of particles of 2 μm or less, volume average particle diameter (Dv), number average particle diameter (Dn), and BET specific surface area The tests of Evaluation 1 under the following conditions (1) to (11) and Evaluation 2 under the following conditions were performed. The test results are shown in Table 1. The upper part of Evaluation 1 and Evaluation 2 in Table 1 is the determination result of the abnormal image, and the lower part is the determination result of the filming (hereinafter the same). In each of the above measurements, the following methods were used to measure (Dv) and (Dn), and the other measurements were performed according to the methods described above.

(Dv, Dn measurement method)
The volume average particle diameter (Dv) and the number average particle diameter (Dn) of the toner are measured with a particle size measuring device (“Multisizer III”, manufactured by Beckman Coulter, Inc.) at an aperture diameter of 100 μm, and analyzed with software (Beckman Coulter Multisizer). 3 Version 3.51). Specifically, 0.5 ml of 10 wt% surfactant (alkylbenzene sulfonate Neogen SC-A; manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was added to a glass 100 ml beaker, 0.5 g of each toner was added, and the mixture was stirred with a micropartel. Subsequently, 80 ml of ion-exchanged water was added. The obtained dispersion was subjected to a dispersion treatment for 10 minutes with an ultrasonic disperser (W-113MK-II, manufactured by Honda Electronics Co., Ltd.). The dispersion was measured using the Multisizer III and Isoton III (manufactured by Beckman Coulter) as the measurement solution. In the measurement, the toner sample dispersion was dropped so that the concentration indicated by the apparatus was 8 ± 2%. In this measurement method, it is important to adjust the concentration to 8 ± 2% from the viewpoint of the reproducibility of the particle size. Within this concentration range, no error occurs in the particle size.

Evaluation 1:
(1) The sample toner used in the experiment and the apparatus were all left for one day in an environmental room at 25 ° C. and 50%.
(2) The PCU (process cartridge unit) built in the Ricoh Copier Imagio neo C600 is charged with the corona charging method, the surface of the image carrier is cleaned with a cleaning blade, and the lubricant is applied. It was modified so that the lubricant could be applied by means. Further, the image bearing member was changed to a photosensitive member whose surface is not reinforced with a filler.
(3) The elastic modulus of the cleaning blade was 70%, the thickness was 2 mm, and the contact angle of the counter with the image carrier was 20 °.
(4) Remove all toner from the PCU, leaving only the carrier in the developing device.
(5) 28 g of black toner serving as a sample is put into a developing device including only a carrier, and 400 g of a developer having a toner concentration of 7% is produced.
(6) A modified PCU is mounted on the Imagio neo C600 main body, and only the developing device is idled for 5 minutes at a developing sleeve linear velocity of 300 mm / s.
(7) Both the developing sleeve and the photoconductor were rotated at 300 mm / s trailing, and the charging potential and the developing bias were adjusted so that the toner on the photoconductor was 0.6 ± 0.05 mg / cm ² .
(8) Under the above development conditions, the transfer current is adjusted so that the transfer rate is 96 ± 2%.
(9) Using the set values, 1000 thin line images shown in FIG. 11 were output.
(10) The thin line part of the character was observed about the image output at the end, and it was visually evaluated whether it was an abnormal image.
(11) “X” is assigned to an image determined to be an abnormal image, and “O” is assigned to an image that is not determined to be an abnormal image.
(12) Further, the image carrier after the experiment was visually confirmed, and “X” was assigned to an object determined to be filming, and “O” was assigned to an object determined not to be filmed.

Evaluation 2:
The PCU (process cartridge unit) incorporated in the Ricoh copier Imagio neo C600 is charged by the proximity discharge charging method, the surface of the image carrier is cleaned by the cleaning blade, and the lubricant application means is used. Modified to be able to apply lubricant. Further, the image bearing member was changed to a photosensitive member whose surface is not reinforced with a filler.
As the charging means using the proximity discharge charging method, the charging means incorporated in the copying machine Imagio neo C600 manufactured by Ricoh Company was used. The same evaluation as evaluation 1 was performed with the above-described modified machine, and abnormal images and filming were determined based on the same criteria.

Example 6
Using the toner produced in Example 1, in the above Evaluation 1 and Evaluation 2, only the photoconductor was changed to an organic photoconductor having a surface layer in which a filler was dispersed, and a similar experiment was performed. As the filler, alumina having an average primary particle size of about 300 nm was used. The evaluation results are shown in Example F of Table 1.

Example 7
Using the toner produced in Example 1, in the above Evaluation 1 and Evaluation 2, only the photoconductor was changed to an organic photoconductor having a protective layer using a crosslinkable charge transport material, and the same experiment was conducted. . An acrylic resin was used as the binder resin, and poly-N-vinylcarbazole was used as the charge transport material. The evaluation results are shown in Example G of Table 1.

From Table 1, in Evaluation 1, the volume average particle diameter Dv is in the range of 3.0 μm ≦ Dv ≦ 7.0 μm, the average value of the shape factor SF-1 is between 120 and 160, and the shape factor SF-2. If the toner has an average value of 100 to 140 and a BET specific surface area of 2.5 to 7.0 (m ² / g), both image quality and filming can be determined to be OK. This is because a certain amount of BET specific surface area is required in order to remove the lubricant on the surface of the image carrier, and if the BET specific surface area becomes too large, minute irregularities on the toner surface are crushed. It can be considered that filming has occurred because part of the film has adhered to the surface of the image carrier.
On the other hand, the same experimental results are obtained when charging means using proximity discharge is used, and in order to remove the deteriorated lubricant on the surface of the image carrier, a certain amount of BET specific surface area is particularly required. It can be considered that the same phenomenon.

1 is a schematic configuration diagram illustrating an example of an image forming apparatus of the present invention. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus of the present invention. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus of the present invention. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus of the present invention. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus of the present invention. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus of the present invention. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus of the present invention. It is a figure which shows the structural example of a process cartridge. It is a figure for demonstrating the calculation method of shape factor SF11, SF2. It is a figure which shows the layer structure of an amorphous silicon photoconductor. It is the chart of the thin line image used for experiment. It is a schematic block diagram which shows an example of the conventional image forming apparatus. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Charging means 2 Exposure means 3 Developing means 4 Transfer means 5 Lubricant 6 Lubricant application means 7 Cleaning means 8 Image carrier 9 Paper feed means 10 Fixing means 11 Cleaning auxiliary means 12 Lubricant leveling means
500 Electrophotographic Photoreceptor 501 Support 502 Photoconductive Layer 503 Surface Layer 504 Charge Injection Blocking Layer 505 Charge Generation Layer 506 Charge Transport Layer

Claims (18)

A charging step for charging the surface of an image carrier made of an electrophotographic photosensitive member, a step for exposing the charged image carrier surface to form a latent image, and developing the formed latent image with toner to form a visible image. An image forming method including a developing step, a transfer step of transferring a formed toner image directly or via an intermediate transfer member onto a transfer medium, and a fixing step of fixing the toner image on the transfer medium.
As a subsequent step of the transfer step, a cleaning step of cleaning the transfer residual toner remaining on the surface of the image carrier with a cleaning blade and a lubricant application step of applying a lubricant to the surface of the image carrier, and
The toner is a water-based granulated toner, and a toner having the following requirements (1) to (4) is used:
An image forming method.
(1) Volume average particle diameter Dv is in the range of 3.0 μm ≦ Dv ≦ 7.0 μm (2) Average value of shape factor SF-1 is between 120 and 160 (3) Shape factor SF− The average value of 2 is between 100 and 140. (4) The BET specific surface area is 2.5 to 7.0 (m ² / g).   2. The image forming method according to claim 1, wherein the charging means in the charging step uses a charging means that does not depend on discharge in a minute gap between the charging means and the image carrier.   3. The image forming method according to claim 1, wherein a volume average particle diameter Dv of the toner is in a range of 3.0 μm ≦ Dv ≦ 5.5 μm.   3. The image forming method according to claim 1, wherein a volume average particle diameter Dv of the toner is in a range of 5.0 μm ≦ Dv ≦ 5.5 μm.   5. The image forming method according to claim 1, wherein a corona charger is used as the charging means in the charging step.   6. The toner according to claim 1, wherein the toner comprises at least a binder resin, a colorant, toner base particles containing a layered inorganic mineral obtained by modifying at least part of a metal cation with an organic cation, and an external additive. The image forming method according to any one of the above. 7. The toner according to claim 1, wherein the BET specific surface area of the external additive contained per unit weight of the toner is 0.5 to 3.5 (m ² / g). The image forming method described.   8. The toner according to claim 1, wherein a ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) is in the range of 1.00 to 1.40. The image forming method according to any one of the above.   9. The image forming method according to claim 1, wherein the toner contains 1 to 10% by number of particles of 2 μm or less. 2. The toner according to claim 1, wherein the toner is obtained by externally adding fine particles having an average primary particle diameter of 50 to 500 nm and a bulk density of 0.3 g / cm ³ or more on the surface of toner base particles. 10. The image forming method according to any one of items 9 to 9.   11. The image forming method according to claim 1, wherein the image carrier is an organic photoreceptor having a surface layer in which a filler is dispersed.   The image carrier is an organic photoreceptor having a protective layer using a crosslinkable charge transport material or an organic photoreceptor having a protective layer using a filler and a crosslinkable charge transport material. Item 11. The image forming method according to any one of Items 1 to 10.   11. The image forming method according to claim 1, wherein the image carrier is an amorphous silicon photoconductor. An image carrier comprising an electrophotographic photosensitive member, a charging means for charging the surface of the image carrier, a latent image forming means for forming a latent image by exposing the charged image carrier surface, and the formed latent image as a toner Developing means for forming a visible image using the toner, transfer means for transferring the formed toner image onto the transfer medium directly or via an intermediate transfer member, and fixing the toner image on the transfer medium In an image forming apparatus provided with at least a fixing unit,
Downstream of the transfer means, a cleaning means for cleaning the transfer residual toner remaining on the surface of the image carrier with a cleaning blade, and a lubricant application means for applying a lubricant to the surface of the image carrier, and
The toner is an aqueous granulated toner and has the following requirements (1) to (4).
(1) Volume average particle diameter Dv is in the range of 3.0 μm ≦ Dv ≦ 7.0 μm (2) Average value of shape factor SF-1 is between 120 and 160 (3) Shape factor SF− The average value of 2 is between 100 and 140. (4) The BET specific surface area is 2.5 to 7.0 (m ² / g).   The image forming apparatus according to claim 14, wherein the charging unit is a charging unit that does not rely on a discharge in a minute gap between the charging unit and the image carrier.   16. The image forming method according to claim 14, wherein the toner has a volume average particle diameter Dv in a range of 3.0 μm ≦ Dv ≦ 5.5 μm.   16. The image forming apparatus according to claim 14, wherein a volume average particle diameter Dv of the toner is in a range of 5.0 μm ≦ Dv ≦ 5.5 μm.   18. A process cartridge used in the image forming apparatus according to claim 14, wherein the image carrier and at least one means selected from a charging means, a developing means, and a cleaning means are integrally supported. A process cartridge which is detachable from the image forming apparatus main body.

Images