JP5371573B2 - Image forming method - Google Patents

Description

  The present invention relates to an image forming method used in a recording method using electrophotography, electrostatic recording, or the like.

  Many methods are known as electrophotographic methods. In general, an electrostatic latent image is formed on a photoreceptor by various means, and then the electrostatic latent image is developed with toner to form a visible image. After the toner image is transferred to a transfer material such as paper, This is a method of cleaning toner remaining on the body. On the other hand, the toner image on the transfer material is fixed on the transfer material by heat, pressure or the like to obtain a copy.

  Among the electrophotographic processes described above, the cleaning step of cleaning the peripheral surface of the photosensitive member by removing the toner remaining on the photosensitive member after the transfer step is an important step for obtaining a clear image.

  As a cleaning method, a method in which a cleaning blade is brought into contact with a photosensitive member so as not to have a gap to scrape off transfer residual toner is mainly used from the viewpoint of cost and ease of design.

  However, in the cleaning method using the cleaning blade, since the frictional force between the cleaning blade and the photosensitive member is large, the cleaning blade is liable to be chattered or twisted. As a result, a cleaning failure easily occurred due to the edge or chipping of the cleaning blade. Here, chattering of the cleaning blade is a phenomenon in which the cleaning blade vibrates due to an increase in frictional resistance between the cleaning blade and the peripheral surface of the photosensitive member. The cleaning blade is a phenomenon that the cleaning blade is reversed in the moving direction of the photosensitive member.

  In particular, the surface layer of the organic photoreceptor is generally formed by a dip coating method, and the surface of the photoreceptor becomes very smooth. Therefore, the contact area between the cleaning blade and the peripheral surface of the electrophotographic photosensitive member is increased, the frictional resistance between the cleaning blade and the surface of the photosensitive member is increased, and the above problem becomes remarkable.

  As one of methods for overcoming the chattering and wrinkling of the cleaning blade, a method of appropriately roughening the surface of the photoreceptor is known. As a technique for roughening the surface of the photoreceptor, for example, the following is disclosed.

  A technique for roughening the surface of an electrophotographic photosensitive member by containing particles in a surface layer (see Patent Document 1). A technique for roughening the surface of the photoreceptor by polishing the surface of the surface layer using a film-like abrasive (see Patent Document 2). A technique for roughening the surface of a photoreceptor by blasting (see Patent Document 3).

  However, when observing the roughened surface-processed area of about several μm on these photoconductors, uniformity in the microscopic area is not obtained, and the effect of improving chatter and wrinkling of the cleaning blade is insufficient. It is.

  Therefore, paying attention to the control of the surface shape of the photoconductor, a photoconductor having a predetermined dimple shape by compressing and molding the surface of the photoconductor using an uneven stamper has been proposed (see Patent Document 4). By this method, the direction of solving problems such as chattering and drowning of the cleaning blade was found. However, in the image forming method using the photosensitive member having such a concavo-convex shape, line reproducibility is liable to be lowered at the time of outputting a high MTF chart such as when a 1 line-1 space image is formed at 600 dpi. This is because the toner is trapped in the concave shape on the surface of the photoreceptor when passing through the development nip.

  In this regard, an image forming method has been proposed in which the problem is improved by defining the relationship between the size of the dimples on the surface of the photoreceptor and the particle sizes of the toner and the external additive (see Patent Document 5).

JP-A-52-026226 Japanese Patent Laid-Open No. 02-139666 Japanese Patent Laid-Open No. 02-150850 JP 2001-0666814 A JP 2007-233357 A

  However, even in the above case, the external additive may accumulate in the dimples and block exposure for forming a latent image. As a result, an original latent image dot cannot be formed, and a part of the necessary toner amount cannot be developed, which may cause an image defect. In the case of reversal development, a solid image appears as a minute white spot (white spot). Turn into.

  As described above, according to the conventional technology, although there is a certain effect on the suppression of image defects, there is still room for improvement in improving the overall performance. .

  An object of the present invention is to provide an image forming method capable of cleaning an excellent photoreceptor even during long-term use and having good image reproducibility.

The present invention includes a step of charging a photosensitive member, a step of forming an electrostatic latent image on the charged photosensitive member, a step of developing the electrostatic latent image with toner to form a toner image on the photosensitive member, An image forming method comprising a step of transferring a toner image on a photoconductor to a transfer material, and a step of removing residual toner on the photoconductor after transfer,
The photoreceptor has concave portions on the surface, and the number of the concave portions is 40 or more and 40,000 or less per 100 μm square, and the average major axis diameter of the opening of the concave portion is 0.5 μm or more and 15.0 μm or less. ,
The toner is a toner having toner particles having a colorant and a binder resin, and inorganic fine powder A, and the inorganic fine powder A includes:
(1) The number average particle diameter of the primary particles is 80 nm or more and 200 nm or less,
(2) The true density is 2.4 g / cm ³ or more and 3.0 g / cm ³ or less,
(3) Total energy TE measured at 7 times after compression, measured using a powder fluidity analyzer, is 2000 mJ or more and 3200 mJ or less,
(4) The present invention relates to an image forming method, wherein the flow velocity index FRI is 0.8 or more and 1.8 or less.

  As described above, according to the present invention, an image forming method that maintains good cleaning performance, good dot reproducibility, and high toner transferability even during long-term durability and various usage environments. Can be provided.

It is a figure which shows the example of a shape of the opening of the recessed part in the photoreceptor surface. It is a figure which shows the example of a cross-sectional shape of the depth direction of the recessed part in the photoreceptor surface. It is a figure which shows the propeller type | mold blade of a powder fluidity analyzer powder rheometer. It is a figure which shows the example (partial enlarged view) of the arrangement pattern of a mask. It is a figure which shows the example of the schematic of a laser processing apparatus. It is a figure which shows the example (partial enlarged view) of the arrangement pattern of the concave-shaped part of the outermost surface of a photoreceptor. It is a figure which shows the example of the schematic of the press-contact shape transcription | transfer processing apparatus by a mold. It is a figure which shows an example of the shape of a mold, (1) shows the mold shape seen from the top, (2) is a figure which shows the mold shape seen from the side. It is a figure which shows the outline of the output chart of Fischer scope H100V (made by Fischer). 1 is an example of a cross-sectional view of an image forming apparatus.

  The photoconductor used in the present invention has a concave portion on the surface thereof in order to prevent chatter and wobbling of the cleaning blade. 1A to 1G show examples of specific shapes of recess openings on the surface of the photoreceptor used in the present invention. 2A to 2E show examples of the cross-sectional shape in the depth direction of the recess. As the shape of the opening, as shown in FIGS. 1A to 1G, various shapes such as a circle, an ellipse, a square, a rectangle, a triangle, and a hexagon can be formed. The present invention can exert an effect regardless of the shape of the opening of the recess.

  As the cross-sectional shape in the depth direction of the concave portion, various shapes can be formed as shown in FIGS. Among them, for example, shapes as shown in FIGS. 2A, 2D, and 2E are preferable. That is, a shape in which the depth (Rdv ′) capable of maintaining the opening shape from the initial opening shape in an arbitrary cross section is 60% or more of the depth (Rdv) of the recess (Rdv ′ / Rdv ≧ 0.6) is preferable. . Here, “the opening shape can be maintained from the initial opening shape” means that the angles θ and θ ′ formed by the surface of the photoreceptor and the inclined surface in the depth direction of the recess in an arbitrary cross section are 80 ° or more and 100 ° or less. It means that there is something (see FIG. 2 (f)). Moreover, it is preferable that the depth of a recessed part is 0.1 micrometer or more and 10 micrometers or less. In the recess having such a cross-sectional shape, the three-dimensional shape of the recess is a columnar or polygonal column. Therefore, even when the photoconductor is scraped due to long-term durability, the opening shape does not change from the initial state, so that it is possible to prevent a cleaning failure due to chattering or wobbling of the cleaning blade.

  The plurality of recesses formed on the surface of the photoconductor preferably have all shapes, sizes, and depths, but even if different shapes, sizes, and depths are mixed, the present invention It can be effective.

  As shown in FIGS. 1A to 1G, the minimum straight line length among the straight lines obtained by projecting the openings of the concave portions in the horizontal direction is defined as the minor axis diameter (Lpc). The maximum straight line length is defined as the major axis diameter (Rpc). For example, the diameter is adopted as the minor axis diameter in the case of a circle, the minor axis in the case of an ellipse, and the shorter one of the sides in the case of a rectangle. In addition, for example, the diameter is adopted as the major axis diameter in the case of a circle, the major axis in the case of an ellipse, and the longer one of diagonal lines in the case of a quadrangle.

  The major axis diameter is measured by dividing the surface of the target photosensitive member into four equal parts in the direction of rotation of the photosensitive member and dividing it into 25 equal parts in a direction perpendicular to the direction of rotation of the photosensitive member. A square region having a side of 100 μm is provided, and the recesses included in the square are performed. The major axis diameter of each of the recesses per unit area thus obtained is statistically processed, and the average value is defined as the average major axis diameter.

  In the present invention, for good cleaning properties, the number of recesses on the surface of the photoreceptor is 40 or more and 40000 or less per 100 μm square, and the average major axis diameter of the openings of the recesses is 0.5 μm or more and 15.0 μm or less. Preferably there is. When the recesses on the surface of the photoconductor satisfy such conditions, the releasability of the toner from the photoconductor is improved and good transferability is obtained. For this reason, the residual toner on the photoreceptor is reduced and the cleaning property is improved. Further, the increase in the frictional force between the photosensitive member and the cleaning blade due to the decrease in the residual toner can be suppressed by the reduction in the contact area between the photosensitive member and the cleaning blade due to the above-described shape, thereby preventing the cleaning blade from being bent or chattered. .

  When the number of the concave portions on the surface of the photoconductor is less than 40 per 100 μm square, the contact area between the photoconductor and the cleaning blade is not reduced, and it is not preferable because the cleaning blade can be prevented from being bent or chattered. Further, when the number of concave portions on the surface of the photoconductor exceeds 40000 per 100 μm square, it is not preferable because the releasability of the toner from the photoconductor is reduced and the transferability is deteriorated.

  When the average major axis diameter of the opening of the concave portion on the surface of the photoconductor is less than 0.5 μm, the contact area between the photoconductor and the cleaning blade is not reduced, and it is not preferable because the cleaning blade can be prevented from being bent or chattered. . Further, when the average major axis diameter of the opening of the concave portion on the surface of the photosensitive member exceeds 15 μm, toner accumulates in the concave portion and is fused to cause image defects (white spots).

  In the present invention, the measurement of the recesses on the surface of the electrophotographic photosensitive member can be performed with a commercially available laser microscope. For example, ultra deep depth measurement microscopes VK-8550 and VK-8700 manufactured by Keyence Co., Ltd., surface shape measurement system Surface Explorer SX-520DR model manufactured by Ryoka System Co., Ltd., and scanning type manufactured by Olympus Co., Ltd. A focus laser microscope OLS3000 and a real color confocal microscope Oplitex C130 manufactured by Lasertec Corporation can be used. Using these laser microscopes, the short axis diameter Lpc of the opening of the concave portion, the long axis diameter Rpc or the longest diameter Epc (described later) of the opening of the concave portion, and the depth Rdv of the concave portion and the cross-sectional area Sdv at a certain field of view with a predetermined magnification. Can be measured. Furthermore, the area ratio of the opening of the recess per unit area can be obtained by calculation.

As an example, a measurement example using an analysis program by the Surface Explorer SX-520DR type machine will be described. The electrophotographic photosensitive member to be measured is placed on the work table, and the tilt is adjusted to adjust the horizontal, and the three-dimensional shape data of the peripheral surface of the electrophotographic photosensitive member is captured in the wave mode. Thereby, the cross-sectional shape of the concave portion on the surface of the photoreceptor can be known. At the time of measurement, the magnification of the objective lens may be 50 times, and field observation of 100 μm × 100 μm (10000 μm ² ) may be performed. In this method, the surface of the photoconductor to be measured is divided into four equal parts in the direction of rotation of the photoconductor and divided into 25 equal parts in a direction perpendicular to the direction of rotation of the photoconductor, Measurement is performed by providing a square region having a side of 100 μm.

  Next, the contour line data of the surface of the electrophotographic photosensitive member is displayed using a particle analysis program in the data analysis software.

The hole analysis parameters of the recess, such as the shape of the recess, the major axis diameter, the depth, and the opening area, can be optimized depending on the formed recess. For example, when observing and measuring a recess having a major axis diameter of about 10 μm, the upper limit of the major axis diameter is 15 μm, the lower limit of the major axis diameter is 1 μm, the lower limit of depth is 0.1 μm, and the lower limit of volume is 1 μm ³ . And the number of the recessed parts which can be discriminate | determined on an analysis screen was counted, and this was made into the number of recessed parts.

  In addition, about the recessed part whose major axis diameter of opening is about 1 micrometer or less, observation with a laser microscope and an optical microscope is possible. In order to further increase the measurement accuracy, a violet laser microscope such as VK-9500, VK-9500GII, VK-9700 manufactured by Keyence Corporation, or a nanosearch microscope SFT-3500 manufactured by Shimadzu Corporation. Alternatively, it is preferable to perform observation and measurement with an electron microscope such as a real surface view microscope VE-7800, VE-8800, VE-9800 manufactured by Keyence Corporation, or a carry scope JCM-5100 manufactured by JEOL.

The toner used in the present invention is a toner having at least a toner particle having a colorant and a binder resin and an inorganic fine powder A, and the inorganic fine powder A includes:
(1) The number average particle diameter of the primary particles is 80 nm or more and 200 nm or less,
(2) The true density is 2.4 g / cm ³ or more and 3.0 g / cm ³ or less,
(3) Total energy TE measured at 7 times after compression, measured using a powder fluidity analyzer, is 2000 mJ or more and 3200 mJ or less,
(4) The flow velocity index FRI is 0.8 or more and 1.8 or less.

  In the above-mentioned photoreceptor, it has been confirmed that the external additive of toner accumulates in the concave portion of the surface after long-term use. As described in the background art, the technique of roughening the surface layer using a film-like abrasive, the technique of roughening the surface of the photoreceptor by blasting, or as shown in FIGS. 2 (b) and 2 (c) In the case of a concave shape, the external additive that has entered the concave portion is relatively easily scraped off by the friction of the cleaning blade. This is presumably because the cross-sectional shape of the recess is a tapered shape. However, in the case of the preferable concave section shape as described above, there is no escape route for the external additive when rubbed with the cleaning blade, and the external additive tends to be compressed and accumulated in the concave portion. Conventionally, it has been thought that the accumulation of external additives in the recesses on the surface of the photoconductor contributes to good cleaning properties. However, if the accumulation of external additives in the recesses becomes significant, minute white spots (white spots) appear in the solid image. ) May occur. This occurs because the external additive accumulates in the recesses on the surface of the photoreceptor, and the exposure for forming the latent image is blocked, so that the original latent image dots cannot be formed and a part of the necessary toner amount cannot be developed. it is conceivable that. Thus, it is necessary to prevent excessive accumulation of the external additive in the recesses on the surface of the photoreceptor.

  As a result of intensive studies, the present inventor has found that the use of inorganic fine powder A satisfying the conditions (1) to (4) as an external additive for toner can prevent excessive accumulation of the external additive. I found it.

  In the inorganic fine powder A used in the present invention, the number average particle size of primary particles is preferably 80 nm or more and 200 nm or less. When the number average particle diameter of the primary particles is less than 80 nm, it is not preferable because it tends to accumulate in the recesses on the surface of the photoreceptor. Further, when the number average particle diameter of the primary particles exceeds 200 nm, the ability to impart fluidity to the toner, which is one of the important roles of the external additive, is inferior, and transferability is deteriorated.

  In addition, about the number average particle diameter of a primary particle, the particle diameter about 100 particle | grains was measured from the photograph image | photographed with the magnification of 50,000 times with the electron microscope, and the average was calculated | required. The particle size of each particle was determined as (a + b) / 2, where a is the longest side of the primary particle and b is the shortest side.

The inorganic fine powder A used in the present invention preferably has a true density of 2.4 g / cm ³ or more and 3.0 g / cm ³ or less. In the present invention, the opening average major axis diameter of the recesses on the photoreceptor surface is 0.5 μm (500 nm) or more, and the number average particle diameter of the primary particles of the inorganic fine powder A is 200 nm or less. It enters the surface recess. The degree to which the entering inorganic fine powder is directly accumulated in the recesses on the surface of the photoreceptor is not determined only by the true density of the inorganic fine powder. However, if the true density is 2.4 g / cm ³ or more and 3.0 g / cm ³ or less, it is preferable that the true density is easily scraped out from the concave portion of the surface of the photoreceptor again by rubbing of the cleaning blade. If the true density is less than 2.4 g / cm ³ , it tends to float in the recesses on the surface of the photoreceptor, and if the true specific gravity exceeds 3.0 g / cm ³ , it tends to deposit on the bottom of the recesses on the photoreceptor surface. Since it is hard to be scraped off from a surface recessed part, it is not preferable.

In addition, the measurement of the true density of the inorganic fine powder of the present invention uses a gas displacement type measurement method using helium. The measurement was performed using Accupic 1330 (manufactured by Shimadzu Corporation). In the measurement method, a precisely measured measurement sample is put in a stainless steel cell having an inner diameter of 18.5 mm, a length of 39.5 mm, and a capacity of 10 cm ³ . Subsequently, the volume of the inorganic fine powder A in the sample cell was measured by a change in the pressure of helium, and the true density was determined from the determined volume and the weight of the sample.

  Furthermore, the inorganic fine powder A used in the present invention has a total energy TE of 2000 mJ or more and 3200 mJ or less, and a flow rate index FRI of 0.8 or more and 1 measured at the seventh measurement after compression, measured using a powder fluidity analyzer. .8 or less is preferable.

  Here, the measurement using a powder fluidity analyzer will be described.

(A) Measurement of total energy TE The total energy TE and flow rate index FRI in the present invention are “powder fluidity analyzer powder rheometer FT4” (manufactured by Freeman Technology, hereinafter, may be abbreviated as FT4). Measure by using.

  Specifically, the measurement is performed by the following operation.

  In all operations, a 48 mm-diameter blade dedicated to FT4 (see FIG. 3; model number: C210, material: SUS, hereinafter may be abbreviated as blade) is used as the propeller blade. This propeller-type blade has a rotation axis in the normal direction at the center of a 48 mm × 10 mm blade plate, and the blade plate has an outermost edge portion (24 mm portion from the rotation shaft) of 70 ° and a portion 12 mm from the rotation shaft. It is smoothly twisted counterclockwise, such as 35 °.

  As the measurement container, a cylindrical split container dedicated to FT4 (model number: C203, material: glass, diameter 50 mm, volume 160 ml, height 82 mm from the bottom surface to the split part, hereinafter may be abbreviated as container) is used. .

For compression of the inorganic fine powder, a compression test piston (diameter 48 mm, height 20 mm, lower mesh tension) is used instead of the propeller blade.
In the measurement, the inorganic fine powder used is left for 3 days or more in an environment of a temperature of 23 ° C. and a humidity of 60% RH.

(1) Compression operation (a) Preliminary experiment: A compression test piston is attached to the main body. Approximately 50 ml of inorganic fine powder (weighed in advance) is placed in a measurement container, and the piston is lowered at 0.5 mm / s to compress the inorganic fine powder. When the load on the piston reaches 20N, the descent is stopped and held for 20 seconds. Read the volume of the compressed inorganic fine powder from the scale of the container.
(B) ¼ inorganic fine powder in an amount corresponding to 180 ml of the volume of the compressed inorganic fine powder calculated from the preliminary experiment (the one used in the preliminary experiment is not used, and an unused inorganic fine powder Use the same procedure as in the preliminary experiment.
(C) The operation of (b) is performed three more times (four times in total) (inorganic fine powder is added).
(D) The inorganic fine powder layer compressed at the split portion of the measurement container is ground and the upper part of the powder layer is removed.

(2) Total energy TE measurement operation (a) A propeller blade is mounted on the main body. The propeller blade is rotated counterclockwise with respect to the surface of the powder layer (direction in which the powder layer is pushed in by rotation of the blade) so that the peripheral speed of the outermost edge of the blade is 10 mm / sec. The blade is advanced in the vertical direction from the surface of the powder layer to a position of 10 mm from the bottom surface of the powder layer at an approach speed of 5 °. Thereafter, the blade rotates clockwise with respect to the surface of the powder layer so that the peripheral speed of the outermost edge of the blade is 60 mm / sec, and the angle forming the vertical entry speed to the powder layer becomes 2 °. It is made to approach to the position of 1 mm from the bottom face of the powder layer at the approach speed. Further, the blade is moved to a position of 100 mm from the bottom surface of the powder layer at a speed of 5 °, and is extracted. When the extraction is completed, the blade is rotated clockwise and counterclockwise alternately, and the inorganic fine powder adhering to the blade is wiped off.
(B) The operation of (2)-(a) is further repeated 6 times (7 times in total), and the rotation obtained when the blade enters the position from 100 mm to 10 mm from the bottom of the powder layer in the final time. The sum of torque and vertical load is defined as total energy TE.

  The total energy TE measured as described above is considered to be an index of energy required for the inorganic fine powder to be released after entering the concave portion of the photoreceptor surface and being compressed.

  In this measurement, the value of the total energy TE is also measured differently if the air content of the powder to be measured is different. In order to improve the reproducibility of the measurement, the compression operation is performed in this measurement. However, after the compression operation, the value of the total energy TE measured from the first operation (2)-(a) did not become a desired energy index. This is presumably because the compression operation actually does not represent the compressed state because the inorganic fine powder has entered the concave portion of the photoreceptor surface. When the inorganic fine powder enters the concave portion of the photoreceptor surface during image formation and is compressed, pressurization by the piston is not performed as in the compression operation. As a result of the examination, it was found that, in this measurement, after the compression operation, the operation of (2)-(a) is performed, and then the value of the total energy TE is measured to obtain a desired energy index.

  The reason why the operations (2) to (a) are performed a total of 7 times is that the measurement result varies when the number of trials is small, and therefore it is necessary to repeat the operation about 7 times in order to stabilize the data. .

  In the present invention, the total energy TE of the inorganic fine powder is set to 2000 mJ or more and 3200 mJ or less, so that the accumulation of the inorganic fine powder in the concave portion on the surface of the photoreceptor is satisfactorily suppressed. When the total energy TE exceeds 3200 mJ, the inorganic fine powder that has entered and compressed into the recesses on the surface of the photoreceptor is difficult to be released, and therefore, it is difficult to be discharged from the recesses. On the other hand, from the above reason, it is considered that the smaller the total energy TE, the better the accumulation of inorganic fine powder in the recesses on the surface of the photoreceptor can be suppressed. However, as a result of the examination, it has been found that when the total energy TE is less than 2000 mJ, the discharge performance from the concave portion of the photoreceptor deteriorates. This is thought to be because when the inorganic fine powder is discharged from the concave portion of the photoreceptor surface, it is more likely to be discharged in a state of being agglomerated to some extent, but the detailed reason is unknown.

(B) Flow velocity index FRI measurement operation (a) Same as (A) Measurement of total energy TE except that the peripheral speed of the outermost edge of the blade is changed to 100 mm / sec in (2)-(a) above. The total energy TE (100) is obtained.
(B) Obtaining the flow velocity index FRI by (total energy TE obtained in (A)) / (total energy TE (100) above) The flow velocity index FRI is easy to solve for the magnitude of the load on the compressed inorganic fine powder. The closer the value is to 1.0, the more it can be solved at a constant level regardless of the magnitude of the load. The load on the compressed inorganic fine powder is a load for releasing the inorganic fine powder accumulated in the concave portion on the surface of the photosensitive member and discharging it to the outside of the concave portion on the photosensitive member surface. For example, rubbing with a cleaning blade, toner And impact due to the intrusion of external additives. During actual image formation, these loads are not always constant. When the load is small, the inorganic fine powder that has entered the surface concave portion of the photoreceptor and is compressed is difficult to be released, and when the load is large, the inorganic fine powder tends to be further compressed by the photoconductor surface concave portion due to the load. If the flow rate index FRI is 0.8 or more and 1.8 or less, it can be solved in the same way regardless of the load applied to the compressed and agglomerated inorganic fine powder. Then, it can be discharged out of the surface of the photoreceptor. When the flow rate index FRI is less than 0.8 or exceeds 1.8, it is not preferable because a stable load cannot be obtained because inorganic fine powder accumulates in the recesses on the surface of the photoreceptor.

  The inorganic fine powder A used in the present invention is not particularly limited as long as it satisfies the above characteristics, but is preferably a carbonate or silicate, more preferably a metal carbonate, and particularly preferably calcium carbonate.

  In the present invention, the inorganic fine powder A preferably has the above-described characteristics from the viewpoint of solving aggregation, but it is also preferable that the adhesion between the inorganic fine powder and the surface of the photoreceptor (including the recesses) is small. Therefore, the inorganic fine powder A of the present invention is a fatty acid represented by the following general formula (1) or a fatty acid metal represented by the following general formula (2) in order to suppress adhesion to the surface of the photoreceptor (including the recesses). The surface is preferably treated with a salt.

(R is a hydrocarbon group having 12 to 28 carbon atoms, X is H or a metal element)

  Specifically, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, montanic acid, and metal salts thereof such as aluminum, zinc, calcium, magnesium, strontium, etc. are preferably used.

  Here, the treatment amount with the fatty acid or the fatty acid metal salt is preferably 0.5% by mass or more and 10% by mass or less of the inorganic fine powder A. If it is in the above range, the inorganic fine powder A is less likely to aggregate, so that accumulation in the concave portion of the photoreceptor surface can be prevented.

  Furthermore, in order to suppress adhesion to the surface of the photoreceptor (including recesses), the fatty acid or fatty acid metal salt is 70% by mass of the compound represented by the general formula (1) in which R is a linear alkyl group. It is preferable to contain above.

Examples of the method for performing the surface treatment of the inorganic fine powder in the present invention include the following methods. In an Ar gas or N ₂ gas atmosphere, the slurry of the inorganic fine powder is placed in a fatty acid sodium aqueous solution, and the desired metal salt aqueous solution is dropped while stirring to precipitate and adsorb the fatty acid metal salt on the surface. it can. For example, if a sodium stearate aqueous solution and aluminum sulfate are used, aluminum stearate can be adsorbed.

However, the characteristics required for the inorganic fine powder in the present invention described above,
(3) The total energy TE is 2000 mJ or more and 3200 mJ or less. (4) In order to satisfy the flow velocity index FRI of 0.8 or more and 1.8 or less, the surface treatment is preferably performed by the following method.

  First, an inorganic fine powder is put into a sealed high-speed stirrer and stirred. Further, the fatty acid or fatty acid metal salt used as the surface treatment agent is melted at a temperature equal to or higher than its melting point, preferably before reaching the boiling point or decomposition point, and sprayed into the stirrer. At this time, it is preferable to keep the temperature of the sealed high-speed stirrer the same as the temperature of the melted surface treatment agent for stable treatment. After spraying the surface treatment agent, the temperature inside the stirrer is gradually returned to room temperature while stirring and then crushed by a pin mill.

  In order to suppress adhesion to the surface of the photoreceptor (including the recesses), the inorganic fine powder A is preferably surface-treated with a silane coupling agent. Examples of silane coupling agents include aminopropyltrimethoxysilane, aminopropyltriethoxysilane, dimethylaminopropyltrimethoxysilane, dimethylaminopropylmethyldiethoxysilane, and diethylaminopropyltrimethoxysilane. , Dipropylaminopropyltrimethoxysilane, dibutylaminopropyltrimethoxysilane, monobutylaminopropyltrimethoxysilane, dioctylaminopropyltrimethoxysilane, dibutylaminopropylmethyldimethoxysilane, dibutylaminopropyldimethylmonomethoxysilane, dimethylaminophenyltri Ethoxysilane, trimethoxysilyl-γ-propylphenylamine, trimethoxysilyl-γ-propylbenzylamine , Trimethoxysilyl-γ-propylpiperidine, trimethoxysilyl-γ-propylmorpholine, trimethoxysilyl-γ-propylimidazole, γ-aminopropyldimethylmethoxysilane, γ-aminopropylmethyldimethoxysilane, 4-aminobutyldimethyl Examples include methoxysilane, 4-aminobutylmethyldiethoxysilane, and N- (2-aminoethyl) aminopropyldimethylmethoxysilane.

  Surface treatment with a silane coupling agent can be carried out by dispersing inorganic fine powder in water to form primary particles and hydrolyzing the silane compound, or by mechanically treating inorganic fine powder or There is a method of dropping or spraying a silane coupling agent while sufficiently stirring with an air stream. At this time, the reactor is preferably purged with nitrogen or heated to 50 to 350 ° C. When the viscosity of the treatment agent is high, it may be diluted with a solvent such as alcohol, ketone, or hydrocarbon. Further, there is a method in which inorganic fine powder is dispersed in an organic solvent, treated with a treating agent, filtered or the solvent is distilled off and then dried. In order to reduce agglomerates, it is also preferable to perform a pulverization treatment thereafter with a pin mill or a jet mill. The drying process may be stationary or flowing, and is preferably heated to about 50 to 350 ° C., and may be decompressed. As the organic solvent, hydrocarbon organic solvents such as toluene, xylene, hexane and isopar are preferably used. As a dispersion treatment method, a stirrer, a shaker, a pulverizer, a mixer, and a disperser are used. Among them, a disperser using a medium such as a ball or a bead made of ceramics, agate, alumina, or zirconia is preferably used. It is done. For example, there are a sand mill, a grain mill, a basket mill, a ball mill, a sand grinder, a visco mill, a paint shaker, an attritor, a dyno mill, and a pearl mill. As a particularly preferred treatment method, a method in which particles to be treated are dispersed in an organic solvent and a treatment agent is added as a paste and then applied to a disperser, a method in which a particle treatment paste of an organic solvent containing a treatment agent is applied to a disperser, There are a method in which a paste obtained by adding a treatment agent and particles to be treated to an organic solvent is applied to a disperser, and a method in which the treatment agent is added while the paste is applied to the disperser. A method of treating in an organic solvent is a preferred method because the particles to be treated can be treated in a dispersed state, coalescence hardly occurs after the treatment, and aggregates are hardly generated. When treating with several kinds of treatment agents, they may be added simultaneously with the preparation of the slurry, may be added sequentially, or may be added when applied to the disperser. Alternatively, when it is applied to the disperser several times, each time it is applied to the disperser, it may be added in advance when it is added and mixed in the slurry or applied to the disperser.

  Further, the surface treatment with a silane coupling agent can be used in combination with the above-described surface treatment with a fatty acid or a metal salt of a fatty acid.

  The inorganic fine powder A of the present invention is preferably added in an amount of 0.05 to 2.00 parts by mass with respect to 100 parts by mass of the toner particles. If the addition amount is within the above range, a sufficient addition effect can be obtained.

In the present invention, in order to further improve the developability, the toner further contains fine particles having a primary particle number average particle diameter of 3 nm to 25 nm and a true density of 0.5 g / cm ^{3 to} 4.5 g / cm ^3. It is preferable to have the body B. Moreover, it is more preferable that the addition amount of the inorganic fine powder A is 0.3 to 1.5 times (mass basis) of the addition amount of the fine powder B.

  As a result of studying the combined use of inorganic fine powder A and finer fine powder, the present inventor has prevented the accumulation of external additives in the concave portion of the photoreceptor surface even under low temperature and low humidity by using the above fine powder, It has been found that good developability can be obtained.

  As fine powder B, metal oxides such as silica, titanium oxide, alumina, zinc oxide and magnesium oxide, metal salts such as calcium carbonate, magnesium carbonate and aluminum carbonate, polyamide resin particles, silicone resin particles, silicone rubber particles, urethane Resin particles such as particles, melamine-formaldehyde particles, and acrylic particles; composite particles composed of rubber, wax, fatty acid compound or resin and inorganic particles of metal, metal oxide, carbon black; Teflon (registered trademark), polyfluoride Fluorine resins such as vinylidene fluoride; fluorinated compounds such as carbon fluoride; fatty acid metal salts such as zinc stearate; fatty acid derivatives such as fatty acid esters; organic particles and composite particles such as molybdenum sulfide, amino acids and amino acid derivatives can be used. .

  In order to obtain long-term durability and stable developability, it is known that particles having a primary particle number average particle diameter of about 50 nm, which are called spacer particles, are added to the toner. Accumulation in was recognized.

Therefore, as a result of studying the combined use with the spacer particles, the present inventors have found that more stable developability can be obtained even during long-term durability while preventing external additive accumulation on the photoreceptor surface recesses under the following conditions. I found it. That is, the number average particle size of the primary particles of the inorganic fine powder C as the spacer particles is 25 nm or more and 70 nm or less, and the true density is 1.5 g / cm ³ or more and 2.3 g / cm ³ or less. Further, by setting the content in the toner to 20% by mass or more and 80% by mass or less of the content of the inorganic fine powder A in the toner, the long-term durability stability of the toner and the accumulation of external additives in the recesses on the photoreceptor surface Can be made better. As the inorganic fine powder C, silica is preferably used.

  When the fine powder B and the inorganic fine powder C are used alone, they may accumulate in the recesses of the photoreceptor to cause image defects, but when combined with the inorganic fine powder A of the present invention, image defects are generated. Each effect can be exhibited without any problems. The following reasons are conceivable. The inorganic fine powder A is easy to be released and has the property of being easily pushed out from the recess regardless of the load applied to the surface of the photoreceptor. Therefore, when the fine powder B or the inorganic fine powder C is used in the toner used in the present invention, the fine powder B or the inorganic fine powder C is pushed out from the concave portion together with the inorganic fine powder A, so that the inorganic fine powder is accumulated in the concave portion. It is considered difficult. As a result, the effect as an external additive of the fine powder B and the inorganic fine powder C can be obtained without causing image defects.

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

  Hereinafter, a method for producing toner particles by suspension polymerization will be described. In the polymerizable monomer, a colorant and, if necessary, a low softening point substance such as wax, a polar resin, a charge control agent, and a polymerization initiator are added. Then, the monomer composition uniformly dissolved or dispersed by a homogenizer or an ultrasonic disperser is dispersed in an aqueous phase containing a dispersion stabilizer by a stirrer, a homogenizer or a homomixer. At this time, granulation is preferably performed by adjusting the stirring speed and time so that the droplets of the monomer composition have a desired toner particle size. Thereafter, stirring may be carried out to such an extent that the particle state of the monomer composition is maintained by the action of the dispersion stabilizer and precipitation of the particles of the monomer composition is prevented. The polymerization temperature is preferably set to 40 ° C. or higher, generally 50 to 90 ° C. The temperature may be raised in the second half of the polymerization reaction, and in order to remove unreacted polymerizable monomers and by-products that cause odor during toner fixing, some water may be added in the second half of the reaction or at the end of the reaction. Alternatively, a part of the aqueous medium may be distilled off. After completion of the reaction, the produced toner particles are recovered by washing and filtration and dried. In the suspension polymerization method, it is usually preferable to use 300 to 3,000 parts by weight of water as a dispersion medium with respect to 100 parts by weight of the monomer composition.

  Toner particle size distribution control and particle size control can be done by adjusting the pH of the aqueous medium during granulation, changing the type and amount of dispersion stabilizer that acts as a water-insoluble inorganic salt or protective colloid, This can be done by controlling the peripheral speed of the rotor of the apparatus, the number of passes, the shape of the stirring blade, the stirring conditions, the container shape, or the solid content concentration in the aqueous solution.

  Examples of the polymerizable monomer used for suspension polymerization include styrene; styrene derivatives such as o- (m-, p-) methylstyrene and m- (p-) ethylstyrene; methyl acrylate, methyl methacrylate, acrylic Propyl acid, propyl methacrylate, butyl acrylate, butyl methacrylate, octyl acrylate, octyl methacrylate, dodecyl acrylate, dodecyl methacrylate, stearyl acrylate, stearyl methacrylate, behenyl acrylate, behenyl methacrylate, acrylic acid Acrylic ester monomers such as 2-ethylhexyl, 2-ethylhexyl methacrylate, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate; butadiene, Isoprene, cyclohexene, acrylonitrile, methacrylonitrile, acrylic acid amide.

  As the polar resin added at the time of polymerization, a copolymer of styrene and acrylic acid or methacrylic acid, a maleic acid copolymer, a polyester resin, and an epoxy resin are preferably used.

  Examples of the polymerization initiator used in the present invention include 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1- Carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, azo polymerization initiators such as azobisisobutylnitrile, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroxy peroxide, 2 Peroxide polymerization initiators such as 1,4-dichlorobenzoyl peroxide and lauroyl peroxide are used. The addition amount of the polymerization initiator varies depending on the desired degree of polymerization, but is generally used at a ratio of 0.5 to 20% by mass (based on the polymerizable monomer) with respect to the polymerizable monomer. . The kind of the polymerization initiator is slightly different depending on the polymerization method, but may be used alone or mixed with reference to the 10-hour half-life temperature.

  As dispersion stabilizers for suspension polymerization, inorganic oxides such as calcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, metasilicic acid Calcium, calcium sulfate, barium sulfate, bentonite, silica, alumina, magnetic material, and ferrite can be mentioned. Examples of the organic compound include polyvinyl alcohol, gelatin, methyl cellulose, methyl hydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, and starch. These dispersion stabilizers are preferably used in a proportion of 0.2 to 2.0 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

  A commercially available dispersion stabilizer may be used as it is, but in order to obtain dispersed particles having a fine uniform particle size, an inorganic compound may be produced in a dispersion medium under high-speed stirring. For example, in the case of calcium phosphate, a dispersion stabilizer preferable for the suspension polymerization method can be obtained by mixing an aqueous sodium phosphate solution and an aqueous calcium chloride solution under high-speed stirring.

  In order to refine these dispersion stabilizers, 0.001 to 0.1 parts by mass of a surfactant may be used in combination with 100 parts by mass of the suspension. Specifically, commercially available nonionic, anionic and cationic surfactants can be used. Examples include sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, and calcium oleate.

  Next, an example of a method for producing toner particles using a pulverization method will be described.

  In the pulverization method, a binder resin, a release agent, a charge control agent, a colorant, and the like are sufficiently mixed by a mixer such as a Henschel mixer or a ball mill. Then, these are melt-kneaded using a heat kneader such as a heating roll, a kneader, an extruder, and the charge control agent and the colorant are dispersed or dissolved in the resins so that they are mutually compatible, and after cooling and solidification, The particle size distribution of the finely pulverized product is sharpened by mechanically pulverizing to a desired particle size and further classification. Alternatively, after cooling and solidification, a finely pulverized product obtained by colliding with a target under a jet stream is spheroidized by heat or mechanical impact force.

  The toner particles obtained as described above are externally added with the above-mentioned inorganic fine powder to obtain the toner according to the present invention.

  Examples of the binder resin used in the pulverization method include polystyrene, poly-α-methylstyrene, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, and styrene-vinyl acetate copolymer. Styrene-acrylic acid ester copolymer, styrene-methacrylic acid acrylic copolymer, vinyl chloride resin, polyester resin, epoxy resin, phenol resin, polyurethane resin. These are used alone or in combination. Of these, styrene-acrylic copolymer resins, styrene-methacrylic copolymer resins, and polyester resins are preferred.

When the toner particles are controlled to be positively charged, the following charge control agents can be used. For example, modified products with fatty acid metal salts; quaternary ammonium salts such as tributylbenzidylammonium-1-hydroxy-4-naphthosulfonate and tetrabutylammonium tetrafluoroborate; tributylbenzidylphosphonium-1-hydroxy-4-naphtho Phosphonium salts such as sulfonates and tetrabutylphosphonium tetrafluoroborate; amines and polyamine compounds; metal salts of higher fatty acids; acetylacetone metal complexes; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide and dicyclohexyltin oxide; dibutyltin borate , Diorganotin borate such as dioctyl tin borate and dicyclohexyl tin borate can be added. In addition, when the toner particles are controlled to be negatively charged, the following charge control agents can be used. For example, organometallic complexes and chelate compounds are effective, monoazo metal complexes, acetylacetone metal complexes, aromatic hydroxycarboxylic acid, metal complexes of aromatic dicarboxylic acids, polymer compounds having sulfonic acid in the side chain, boron compounds, urea compounds , Silicon compounds, calixarene, and the like can be used. The amount of these charge control agents used is 0.1 to 15 parts by mass, preferably 0.1 to 10 parts by mass, with respect to 100 parts by mass of the binder resin.
As the charge control agent used in the present invention, a known charge control agent can be used, but a charge control agent having no polymerization inhibitory property and no soluble component in an aqueous medium is particularly preferable.

  A low softening point substance can be added to the toner particles as necessary. Low softening point substances include aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, paraffin wax, and Fischer-Tropsch wax or their oxides; aliphatic esters such as carnauba wax and montanate wax. And wax obtained by deoxidizing a part or all of the wax. Furthermore, saturated linear fatty acids such as palmitic acid, stearic acid, and montanic acid; unsaturated fatty acids such as brandic acid, eleostearic acid, and valinalic acid; stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnauvyl alcohol, and seryl alcohol Saturated alcohols such as melisyl alcohol; polyhydric alcohols such as sorbitol; fatty acid amides such as linoleic acid amide; saturated fatty acid bisamides such as methylenebisstearic acid amide; unsaturated fatty acid amides such as ethylene bisoleic acid amide Aromatic bisamides such as N, N'-distearylisophthalic acid amide; fatty acid metal salts such as zinc stearate; waxes grafted to aliphatic hydrocarbon waxes using vinyl monomers such as styrene; Such fatty acids and partial esters of polyhydric alcohols behenic acid monoglyceride; and methyl ester having a hydroxyl group obtained by hydrogenation of vegetable fats and oils. The addition amount of the low softening point substance is 0.1 to 20 parts by mass, preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the binder resin (or polymerizable monomer).

  Next, a method for forming the surface of the electrophotographic photosensitive member will be described. The method for forming the surface shape is not particularly limited as long as the method can satisfy the requirements related to the concave portion. Examples of the method for forming the surface of an electrophotographic photosensitive member include a method for forming a surface of an electrophotographic photosensitive member by laser irradiation having an output characteristic having a pulse width of 100 ns (nanoseconds) or less, and a mold having a predetermined shape as an electron. There is a method of forming a surface that is pressed against the surface of a photographic photosensitive member and performs shape transfer.

  A method for forming the surface of an electrophotographic photosensitive member by laser irradiation having an output characteristic with a pulse width of 100 ns (nanoseconds) or less will be described. Specific examples of the laser used in this method include an excimer laser using a gas such as ArF, KrF, XeF or XeCl as a laser medium or a femtosecond laser using titanium sapphire as a medium. Furthermore, the wavelength of the laser beam in the laser irradiation is preferably 1,000 nm or less.

  The excimer laser is laser light emitted in the following steps. First, high energy such as discharge, electron beam or X-ray is applied to a mixed gas of a rare gas such as Ar, Kr or Xe and a halogen gas such as F or Cl to excite the above elements. And combine them. Thereafter, excimer laser light is emitted when dissociating by falling to the ground state. Examples of the gas used in the excimer laser include ArF, KrF, XeCl, and XeF, and any of them may be used. In particular, KrF or ArF is preferable.

As a method for forming the concave portion, a mask in which the laser light shielding portion a and the laser light transmitting portion b shown in FIG. 4 are appropriately arranged is used. Only the laser beam that has passed through the mask is condensed by the lens and irradiated on the surface of the electrophotographic photosensitive member, thereby forming a concave portion having a desired shape and arrangement. In the above method for forming the surface of an electrophotographic photosensitive member by laser irradiation, a large number of concave portions within a certain area can be processed instantaneously and simultaneously regardless of the shape or area of the concave portion. It can be performed in a short time. An area of several mm ² to several cm ^{2 on} the surface of the electrophotographic photosensitive member is processed per irradiation by laser irradiation using a mask. In laser processing, as shown in FIG. 5, first, the electrophotographic photosensitive member f is rotated by a workpiece rotating motor d. While rotating, the workpiece moving device e shifts the laser irradiation position of the excimer laser beam irradiator c in the axial direction of the electrophotographic photosensitive member f, thereby efficiently forming a concave shape over a wide area of the surface of the electrophotographic photosensitive member. The part can be formed.

  By the method for forming the surface of the electrophotographic photosensitive member by laser irradiation, an electrophotographic photosensitive member having a plurality of independent concave portions on the surface layer can be produced. Further, when the major axis diameter of the concave part is Rpc and the depth indicating the distance between the deepest part of the concave part and the aperture surface is Rdv, the ratio of the depth to the major axis diameter (Rdv / Rpc) is It can be larger than 1.0 and 7.0 μm or smaller. The depth of the concave portion is arbitrary within the above range. When forming the surface of the electrophotographic photosensitive member by laser irradiation, the depth of the concave portion can be adjusted by adjusting the manufacturing conditions such as the laser irradiation time and the number of times. You can control it. From the viewpoint of manufacturing accuracy or productivity, when forming the surface of an electrophotographic photosensitive member by laser irradiation, the depth of the concave portion by one irradiation should be 0.1 μm or more and 2.0 μm or less. Desirably, it is preferably 0.3 μm or more and 1.2 μm or less. By using the method of forming the surface of the electrophotographic photosensitive member by laser irradiation, the surface processing of the electrophotographic photosensitive member can be realized with high controllability of the size, shape and arrangement of the concave portions, and high accuracy and high flexibility. .

  Further, in the method for forming the surface of the electrophotographic photosensitive member by laser irradiation, the above-described surface forming method may be applied to a plurality of portions or the entire surface of the photosensitive member using the same mask pattern. By this method, a highly uniform concave portion can be formed on the entire surface of the photoreceptor. As a result, the mechanical load applied to the cleaning blade when used in the electrophotographic apparatus becomes uniform. Further, as shown in FIG. 6, a mask pattern is formed so as to form an array in which both the concave-shaped portion h and the concave-shaped non-formed portion g exist on an arbitrary circumferential line (indicated by an arrow) of the photosensitive member. Thus, the uneven distribution of the mechanical load on the cleaning blade can be further suppressed.

  Next, a method for forming a surface for transferring a shape by pressing a mold having a predetermined shape against the surface of the electrophotographic photoreceptor will be described.

  Fig.7 (a) is a figure which shows the example of the schematic of the press-contact shape transfer processing apparatus by the mold in this invention. After the predetermined mold B is attached to the pressure device A that can repeatedly press and release, the mold is brought into contact with the electrophotographic photoreceptor C at a predetermined pressure to transfer the shape. Thereafter, the pressurization is once released and the electrophotographic photosensitive member C is rotated, and then the pressurization and the shape transfer process are performed again. By repeating this process, it is possible to form a predetermined concave portion over the entire circumference of the electrophotographic photosensitive member.

  Further, for example, the concave portion may be formed by a method as shown in FIG. That is, a mold B having a predetermined shape about the length of the circumference of the surface of the electrophotographic photosensitive member C is attached to the pressure device A. Thereafter, the electrophotographic photosensitive member C is rotated (in the direction indicated by the arrow) and moved (in the direction indicated by the arrow) while applying a predetermined pressure to the electrophotographic photosensitive member C. A concave portion is formed.

  It is also possible to sandwich the sheet-shaped mold between the roll-shaped pressing device and the electrophotographic photosensitive member, and to perform surface processing while feeding the mold sheet.

  Further, for the purpose of efficiently transferring the shape, the mold or the electrophotographic photosensitive member may be heated. The heating temperature of the mold and the electrophotographic photosensitive member is arbitrary as long as the shape of the present invention can be formed, but the temperature (° C.) of the mold at the time of shape transfer is the temperature of the resin forming the photosensitive layer on the support of the photosensitive member. Heating is preferably performed so as to be higher than the glass transition temperature (° C.). Further, in addition to the heating of the mold, the temperature (° C.) of the support during shape transfer is controlled to be lower than the glass transition temperature (° C.) of the photosensitive layer. It is preferable for forming the shape portion stably.

  When the electrophotographic photoreceptor of the present invention is a photoreceptor having a charge transport layer, the mold temperature (° C.) during shape transfer is set higher than the glass transition temperature (° C.) of the charge transport layer on the support. It is preferable to be heated. Furthermore, in addition to the mold heating, the temperature of the support during shape transfer (° C) is controlled to be lower than the glass transition temperature (° C) of the charge transport layer. It is preferable when forming a part stably.

  The material, size, and shape of the mold itself can be selected as appropriate. Examples of the material include a metal having a fine surface processed and a silicon wafer patterned with a resist, a resin film in which fine particles are dispersed, or a metal film coated on a resin film having a predetermined fine surface shape. An example of the mold shape is shown in FIG. In FIG. 8, (1) shows the mold shape seen from above, and (2) shows the mold shape seen from the side.

  Further, an elastic body may be provided between the mold and the pressure device for the purpose of imparting pressure uniformity to the photoreceptor.

  An electrophotographic photosensitive member having a plurality of independent concave portions on the surface layer can be produced by the surface forming method in which a mold having a predetermined shape is pressed against the surface of the electrophotographic photosensitive member to perform shape transfer. it can. When the major axis diameter of the concave part is Rpc and the depth indicating the distance between the deepest part of the concave part and the aperture surface is Rdv, the depth of the major axis diameter is adjusted by adjusting the shape of the mold. The ratio of thickness (Rdv / Rpc) can be made larger than 1.0 and 7.0 or smaller. The depth of the concave portion is arbitrary within the above range. However, when forming a surface for shape transfer by pressing a mold having a predetermined shape against the surface of the electrophotographic photosensitive member, the depth is 0. It is desirable that the thickness be 1 μm or more and 10 μm or less. By using a surface formation method in which a mold having a predetermined shape is pressed against the surface of the electrophotographic photosensitive member to transfer the shape, the size, shape, and arrangement of the concave portions are highly controllable, with high accuracy and flexibility. High surface processing of an electrophotographic photosensitive member can be realized.

  Next, the configuration of the electrophotographic photosensitive member used in the present invention will be described.

  As described above, the electrophotographic photosensitive member used in the present invention has a support and an organic photosensitive layer provided on the support. In general, a cylindrical organic electrophotographic photosensitive member having a photosensitive layer formed on a cylindrical support is widely used as the electrophotographic photosensitive member, but a belt-like or sheet-like shape is also possible.

  Even if the photosensitive layer is a single-layer type photosensitive layer containing the charge transport material and the charge generation material in the same layer, the charge generation layer containing the charge generation material and the charge transport layer containing the charge transport material Separated layered (functionally separated type) photosensitive layers may be used. From the viewpoint of electrophotographic characteristics, a laminated photosensitive layer is preferred. In addition, even if the laminated type photosensitive layer is a normal type photosensitive layer in which the charge generation layer and the charge transport layer are laminated in this order from the support side, the reverse layer type photosensitive layer in which the charge transport layer and the charge generation layer are laminated in order from the support side. It may be a layer. In the electrophotographic photoreceptor according to the present invention, when a laminated type photosensitive layer is employed, a normal layer type photosensitive layer is preferable from the viewpoint of electrophotographic characteristics. Further, the charge generation layer may have a laminated structure, and the charge transport layer may have a laminated structure. Furthermore, it is possible to provide a protective layer on the photosensitive layer for the purpose of improving the durability performance.

  As the support, those having conductivity (conductive support) are preferable, and for example, a metal support such as aluminum, aluminum alloy, or stainless steel can be used. In the case of aluminum or aluminum alloy, ED tube, EI tube, or these are cut, electrolytic composite polishing (electrolysis with electrode having electrolytic action and polishing with grinding stone having polishing action), wet or dry honing treatment Can also be used. In addition, the above metal support or resin support (polyethylene terephthalate, polybutylene terephthalate, phenol resin, polypropylene or polystyrene resin) having a layer formed by vacuum deposition of aluminum, aluminum alloy or indium oxide-tin oxide alloy Can also be used. In addition, a support in which conductive particles such as carbon black, tin oxide particles, titanium oxide particles, or silver particles are impregnated in a resin or paper, or a plastic having a conductive binder resin can also be used.

  The surface of the support may be subjected to cutting treatment, roughening treatment, alumite treatment, etc. for the purpose of preventing interference fringes due to scattering of laser light or the like.

When the volume resistivity of the support is a layer provided for imparting conductivity to the surface of the support, the volume resistivity of the layer is preferably 1 × 10 ¹⁰ Ω · cm or less, In particular, it is more preferably 1 × 10 ⁶ Ω · cm or less.

  Between the support and an intermediate layer or photosensitive layer (charge generation layer, charge transport layer), which will be described later, a conductive layer for the purpose of preventing interference fringes due to scattering of laser light, etc., and covering scratches on the support May be provided. This is a layer formed by applying a coating liquid in which conductive powder is dispersed in an appropriate binder resin.

  Examples of such conductive powder include the following. Carbon black, acetylene black; metal powder such as aluminum, nickel, iron, nichrome, copper, zinc or silver; metal oxide powder such as conductive tin oxide or ITO.

  Moreover, as binder resin used simultaneously, the following thermoplastic resins, thermosetting resins, or photocurable resin resins are mentioned. Polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, polyarylate Resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin or alkyd resin .

  The conductive layer consists of the conductive powder and the binder resin, an ether solvent such as tetrahydrofuran or ethylene glycol dimethyl ether; an alcohol solvent such as methanol; a ketone solvent such as methyl ethyl ketone; an aromatic carbon such as toluene. It can be formed by dispersing or dissolving in a hydrogen solvent and applying it. The average film thickness of the conductive layer is preferably 0.2 μm or more and 40 μm or more, more preferably 1 μm or more and 35 μm or less, and even more preferably 5 μm or more and 30 μm or less.

  The surface of a conductive layer in which a conductive pigment or a resistance adjusting pigment is dispersed tends to be roughened.

  An intermediate layer having a barrier function or an adhesive function may be provided between the support or the conductive layer and the photosensitive layer (charge generation layer, charge transport layer). The intermediate layer is formed, for example, for improving adhesion of the photosensitive layer, improving coating properties, improving charge injection from the support, and protecting the photosensitive layer from electrical breakdown.

  The intermediate layer can be formed by applying a curable resin and then curing to form a resin layer, or by applying an intermediate layer coating solution containing a binder resin on the conductive layer and drying.

  Examples of the binder resin for the intermediate layer include the following. Water-soluble resin such as polyvinyl alcohol, polyvinyl methyl ether, polyacrylic acid, methyl cellulose, ethyl cellulose, polyglutamic acid or casein; polyamide resin, polyimide resin, polyamideimide resin, polyamic acid resin, melamine resin, epoxy resin, polyurethane resin or poly Glutamic acid ester resin. In order to effectively develop the electrical barrier property, the binder resin of the intermediate layer is preferably a thermoplastic resin from the viewpoints of coatability, adhesion, solvent resistance and resistance. Specifically, a thermoplastic polyamide resin is preferable. The polyamide resin is preferably a low crystalline or non-crystalline copolymer nylon that can be applied in a solution state. The average film thickness of the intermediate layer is preferably 0.05 μm or more and 7 μm or less, and more preferably 0.1 μm or more and 2 μm or less.

  In addition, in order to prevent the flow of electric charges (carriers) in the intermediate layer, semiconductive particles are dispersed in the intermediate layer, or an electron transport material (electron-accepting material such as an acceptor) is contained. You may let them.

Next, the photosensitive layer will be described.
Examples of the charge generating material added to the photosensitive layer include the following. Azo pigments such as monoazo, disazo or trisazo; phthalocyanine pigments such as metal phthalocyanine or non-metal phthalocyanine; indigo pigments such as indigo or thioindigo; perylene pigments such as perylene anhydride or perylene imide; anthraquinone or pyrenequinone Polycyclic quinone pigments such as: squarylium dyes, pyrylium salts or thiapyrylium salts, triphenylmethane dyes; inorganic substances such as selenium, selenium-tellurium or amorphous silicon; quinacridone pigments, azurenium salt pigments, cyanine dyes, xanthene dyes, quinoneimines Dye or styryl dye. These charge generation materials may be used alone or in combination of two or more. Among these, metal phthalocyanines such as oxytitanium phthalocyanine, hydroxygallium phthalocyanine or chlorogallium phthalocyanine are particularly preferable because of their high sensitivity.

  When the photosensitive layer is a laminated photosensitive layer, examples of the binder resin used for the charge generation layer include the following. Polycarbonate resin, polyester resin, polyarylate resin, butyral resin, polystyrene resin, polyvinyl acetal resin, diallyl phthalate resin, acrylic resin, methacrylic resin, vinyl acetate resin, phenol resin, silicone resin, polysulfone resin, styrene-butadiene copolymer resin Alkyd resin, epoxy resin, urea resin or vinyl chloride-vinyl acetate copolymer resin. In particular, a butyral resin is preferred. These can be used singly or in combination of two or more as a mixture or copolymer.

  The charge generation layer can be formed by applying and drying a charge generation layer coating solution obtained by dispersing a charge generation material together with a binder resin and a solvent. The charge generation layer may be a vapor generation film of a charge generation material. Examples of the dispersion method include a method using a homogenizer, an ultrasonic wave, a ball mill, a sand mill, an attritor, or a roll mill. The ratio between the charge generating material and the binder resin is preferably in the range of 10: 1 to 1:10 (mass ratio), and more preferably in the range of 3: 1 to 1: 1 (mass ratio).

  The solvent used for the charge generation layer coating solution is selected from the solubility and dispersion stability of the binder resin and charge generation material used. Examples of the organic solvent include alcohol solvents, sulfoxide solvents, ketone solvents, ether solvents, ester solvents, and aromatic hydrocarbon solvents.

  The average film thickness of the charge generation layer is preferably 5 μm or less, and more preferably 0.1 to 2 μm.

  In addition, various sensitizers, antioxidants, ultraviolet absorbers and / or plasticizers can be added to the charge generation layer as necessary. In order to prevent the flow of charges (carriers) in the charge generation layer from stagnation, the charge generation layer may contain an electron transport material (an electron accepting material such as an acceptor).

  Examples of the charge transport material used in the electrophotographic photoreceptor include a triarylamine compound, a hydrazone compound, a styryl compound, a stilbene compound, a pyrazoline compound, an oxazole compound, a thiazole compound, or a triallylmethane compound. These charge transport materials may be used alone or in combination of two or more.

  The charge transport layer can be formed by applying a charge transport layer coating solution obtained by dissolving a charge transport material and a binder resin in a solvent, and drying it. In addition, among the above charge transport materials, those having film formability alone can be formed as a charge transport layer by itself without using a binder resin.

  When the photosensitive layer is a laminated photosensitive layer, examples of the binder resin used for the charge transport layer include the following. Acrylic resin, styrene resin, polyester resin, polycarbonate resin, polyarylate resin, polysulfone resin, polyphenylene oxide resin, epoxy resin, polyurethane resin, alkyd resin or unsaturated resin. In particular, polymethyl methacrylate resin, polystyrene resin, styrene-acrylonitrile copolymer resin, polycarbonate resin, polyarylate resin or diallyl phthalate resin is preferable. These can be used singly or in combination of two or more as a mixture or copolymer.

  The charge transport layer can be formed by applying and drying a charge transport layer coating solution obtained by dissolving a charge transport material and a binder resin in a solvent. The ratio between the charge transport material and the binder resin is preferably in the range of 2: 1 to 1: 2 (mass ratio).

  The following are mentioned as a solvent used for the coating liquid for charge transport layers. Ketone solvents such as acetone or methyl ethyl ketone; ester solvents such as methyl acetate or ethyl acetate; ether solvents such as tetrahydrofuran, dioxolane, dimethoxymethane or dimethoxyethane; aromatic hydrocarbons such as toluene, xylene or chlorobenzene solvent. These solvents may be used alone or in combination of two or more. Among these solvents, it is preferable to use an ether solvent or an aromatic hydrocarbon solvent from the viewpoint of resin solubility.

  The average film thickness of the charge transport layer is preferably 5 to 50 μm, more preferably 10 to 35 μm.

  In addition, for example, an antioxidant, an ultraviolet absorber, and a plasticizer can be added to the charge transport layer as necessary.

  In improving the durability of the electrophotographic photosensitive member, the material design of the charge transport layer serving as the surface layer is important in the case of the function-separated type photosensitive member. For example, a method using a high-strength binder resin, a method for optimizing the ratio between a charge transporting material and a binder resin exhibiting plasticity, and a method using a polymer charge transporting material can be mentioned. In order to achieve this, it is effective to form the surface layer with a curable resin.

  Examples of the method of constituting the surface layer with a curable resin include, for example, constituting the charge transport layer with a curable resin, and curing as a second charge transport layer or a protective layer on the charge transport layer. Forming a base resin layer. The characteristics required for the curable resin layer are both the strength of the film and the charge transport capability, and it is generally composed of a charge transport material and a polymerized or crosslinkable monomer or oligomer.

  In the method of constituting these surface layers with a curable resin, known hole transporting compounds and electron transporting compounds can be used as the charge transporting material. Examples of materials for synthesizing these compounds include chain polymerization materials having an acryloyloxy group or a styrene group. In addition, a material such as a sequential polymerization system having a hydroxyl group, an alkoxysilyl group or an isocyanate group can be used. In particular, a combination of a hole transporting compound and a chain polymerization material is preferable from the viewpoint of electrophotographic characteristics, versatility, material design, and production stability of an electrophotographic photosensitive member having a surface layer made of a curable resin. Furthermore, an electrophotographic photoreceptor constituted by a surface layer obtained by curing a compound having both a hole transporting group and an acryloyloxy group in the molecule is particularly preferable.

  As the curing means, known means such as heat, light or radiation can be used.

  In the case of the charge transport layer, the average thickness of the cured layer is preferably 5 μm or more and 50 μm or less, and more preferably 10 μm or more and 35 μm or less. In the case of the second charge transport layer or protective layer, the thickness is preferably 0.1 μm or more and 20 μm or less, and more preferably 1 μm or more and 10 μm or less.

  Various additives can be added to each layer of the electrophotographic photoreceptor of the present invention. Examples of the additive include a deterioration inhibitor such as an antioxidant, an ultraviolet absorber or a light stabilizer, organic fine particles, and inorganic fine particles. Examples of the deterioration inhibitor include hindered phenol antioxidants, hindered amine light stabilizers, sulfur atom-containing antioxidants, and phosphorus atom-containing antioxidants. Examples of the organic fine particles include polymer resin particles such as fluorine atom-containing resin particles, polystyrene fine particles, and polyethylene resin particles. Examples of the inorganic fine particles include metal oxides such as silica and alumina.

  As described above, the electrophotographic photosensitive member used in the present invention has a specific concave portion on the surface of the electrophotographic photosensitive member. The concave portion of the present invention works effectively when applied to a photoreceptor whose surface is not easily worn.

The elastic deformation rate of the surface layer of the electrophotographic photoreceptor is preferably 40% or more and 70% or less, more preferably 45% or more and 65% or less, and even more preferably 50% or more and 60% or less. preferable. Further, the universal hardness value of the surface of the electrophotographic photosensitive member (HU) is preferably at 140 N / mm ² or more 240 mm ² or less, further preferably has a 150 N / mm ² or more 220 N / mm ² or less .

In the present invention, the universal hardness value (HU) and elastic deformation rate of the surface of the electrophotographic photosensitive member are as follows: Microhardness measuring device Fischerscope H100V (manufactured by Fischer) It is the value measured using. The Fischerscope H100V has a continuous hardness by contacting an indenter with a measurement object (the peripheral surface of the electrophotographic photosensitive member), continuously applying a load to the indenter, and directly reading the indentation depth under the load. It is a required device. In the present invention, a Vickers quadrangular pyramid diamond indenter having a facing angle of 136 ° was used as the indenter, and the indenter was pressed against the peripheral surface of the electrophotographic photosensitive member.
Final load applied to the indenter continuously (final load): 6 mN
Time for holding a state where a final load of 6 mN is applied to the indenter (holding time): 0.1 second In addition, the measurement points were 273 points.

  FIG. 9 is a diagram showing an outline of an output chart of the Fischer scope H100V (Fischer). In FIG. 9, the vertical axis represents the load F (mN) applied to the indenter, and the horizontal axis represents the indentation depth h (μm). FIG. 9 shows the results when the load applied to the indenter is increased stepwise to maximize the load (A → B) and then decreased gradually (B → C).

The universal hardness value can be obtained by the following equation from the indentation depth of the indenter when a final load of 6 mN is applied to the indenter. In the following formula, HU represents universal hardness, Ff represents the final load (unit N), and Sf represents the surface area (mm ² ) of the portion where the indenter is pushed when the final load is applied. Hf represents the indentation depth (mm) of the indenter when the final load is applied.

  In addition, the elastic deformation rate is the work amount (energy) performed by the indenter on the measurement target (the peripheral surface of the electrophotographic photosensitive member), that is, the increase / decrease of the load on the measurement target (the peripheral surface of the electrophotographic photosensitive member) It can be obtained from the change in energy due to. Specifically, a value (We / Wt) obtained by dividing the elastic deformation work We by the total work Wt is the elastic deformation rate. The total work Wt is the area of the region surrounded by A-B-D-A in FIG. 9, and the elastic deformation work We is the region surrounded by C-B-D-C in FIG. Area.

  When applying the coating liquid of each of the above layers, an application method such as a dip coating method, a spray coating method, a spinner coating method, a roller coating method, a Meyer bar coating method, a blade coating method or a ring coating method may be used. it can.

Next, the image forming method of the present invention will be described.
FIG. 10A is an example of a cross-sectional view of an image forming apparatus to which the image forming method of the present invention can be applied. In FIG. 10A, the photosensitive member 1 is rotationally driven in the direction of an arrow by a driving device (not shown).

  The surface of the photoreceptor 1 is charged to a desired potential by charging means. FIG. 10A shows a corona charging method using the scorotron charger 2, but a contact charging method or a proximity charging method can also be used.

  A desired electrostatic latent image is formed on the surface of the charged photoreceptor 1 by the exposure device 3.

  The electrostatic latent image formed on the photoreceptor 1 is developed as a toner image by the developing device 4. The development method may be either a one-component development method or a two-component development method, and may be contact development or non-contact development.

  The developing device 4 includes a developing sleeve 4a as a toner carrier. The developing sleeve 4a is rotatably arranged with a part of its outer peripheral surface exposed to the outside of the developing device 4. A magnet roller (not shown) fixed in a non-rotating manner is inserted into the developing sleeve 4a. A toner coating blade 4b is provided facing the developing sleeve 4a. A developer 5 is accommodated in the developing device 4.

  The developing sleeve 4a is disposed in contact with the photosensitive member 1 while maintaining contact with the photosensitive member 1 or a closest distance (S-Dgap). S-Dgap is appropriately set in a range of about 0.2 μm to 1.0 μm in the one-component development method and about 0.3 μm to 2.0 μm in the two-component development method. A facing portion between the photoreceptor 1 and the developing sleeve 4a is a developing portion.

  A predetermined developing bias is applied to the developing sleeve 4a. The developing bias voltage applied to the developing sleeve 4a is preferably an oscillating voltage obtained by superimposing a DC voltage (Vdc) and an AC voltage (Vac).

  When the developer that forms a layered thin layer on the developing sleeve 4a is conveyed to the developing unit, the photosensitive member 1 corresponds to the electrostatic latent image formed on the photosensitive member 1 by an electric field due to a developing bias. Selectively adheres to the surface of The electrostatic latent image formed on the photoreceptor 1 in this way is developed as a toner image.

The toner image formed on the photoreceptor 1 is transferred to the transfer material 6 by a transfer device including a corona charger 7. As the transfer device, a transfer device including a transfer roller can be used.
Further, an intermediate transfer member can be used as shown in FIG. In FIG. 10B, the intermediate transfer member 9 is mainly composed of a primary transfer roller 9a and an intermediate transfer belt 9b. A bias having a reverse polarity to the toner of the toner image is applied to the primary transfer roller to transfer the toner image to the intermediate transfer belt 9b. Further, the toner image transferred onto the intermediate transfer belt 9 b is transferred to the transfer material 6 by applying a bias having a reverse polarity to the toner of the toner image to the secondary transfer roller 10.
Further, the toner remaining on the photoconductor 1 after the transfer process is removed from the photoconductor 1 by the cleaning blade 8.

  Hereinafter, the present invention will be described in more detail with reference to specific examples. Unless otherwise specified, “part” in the examples represents “part by mass”.

<Photoconductor Production Example 1>
An aluminum cylinder having a diameter of 84 mm and a length of 370.0 mm cut was used as a support (cylindrical support).

Next, a solution comprising the following components was dispersed with a ball mill for about 20 hours to prepare a conductive layer coating.
60 parts of powder composed of barium sulfate particles having a tin oxide coating layer
(Product name: Pastoran PC1, Mitsui Mining & Smelting Co., Ltd.)
Titanium oxide 15 parts
(Product name: TITANIX JR, manufactured by Teika)
43 parts of resol type phenol resin (trade name: Phenolite J-325, manufactured by Dainippon Ink & Chemicals, Inc., solid content 70%)
0.015 parts of silicone oil
(Product name: SH28PA, manufactured by Toray Silicone Co., Ltd.)
3.6 parts of silicone resin
(Product name: Tospearl 120, manufactured by Toshiba Silicone Co., Ltd.)
2-methoxy-1-propanol 50 parts Methanol 50 parts The coating material for conductive layer prepared by the above method is applied onto the support by the dipping method, and is cured by heating in an oven heated to 140 ° C for 1 hour. Thus, a conductive layer having an average film thickness of 15 μm at a position 170 mm from the upper end of the support was formed.

Next, an intermediate layer coating solution in which the following components are dissolved in a mixed solution of methanol 400 parts / n-butanol 200 parts is dip-coated on the conductive layer, and heated in an oven heated to 100 ° C. for 30 minutes. Heat-dried. Then, an intermediate layer having an average film thickness of 0.45 μm at a position of 170 mm from the upper end of the support was formed.
Copolymer nylon resin 10 parts
(Product name: Amilan CM8000, manufactured by Toray Industries, Inc.)
30 parts of methoxymethylated 6 nylon resin
(Product name: Toresin EF-30T, manufactured by Teikoku Chemical Co., Ltd.)

Next, the following components were dispersed in a sand mill apparatus using glass beads having a diameter of 1 mm for 4 hours, and then 700 parts of ethyl acetate was added to prepare a charge generation layer coating material.
20 parts of hydroxygallium phthalocyanine (in CuKα characteristic X-ray diffraction, 7.5 °, 9.9 °, 16.3 °, 18.6 °, 25.1 °, 28.3 ° (Bragg angle (2θ ± 0. Having a strong diffraction peak at 2 °))
The following structural formula (1)

Calixarene compound represented by 0.2 part polyvinyl butyral 10 parts
(Product name: ESREC BX-1, manufactured by Sekisui Chemical)
600 parts of cyclohexanone The above coating film for charge generation layer is applied on the intermediate layer by dip coating, and is heated and dried in an oven heated to 80 ° C. for 15 minutes, whereby the average film thickness at 170 mm position from the upper end of the support is obtained. A 0.17 μm charge generation layer was formed.

Next, the following components were dissolved in a mixed solvent of 600 parts of chlorobenzene and 200 parts of methylal to prepare a charge transport layer coating material. Using this, the charge transport layer is dip-coated on the charge generation layer and dried in an oven heated to 100 ° C. for 30 minutes, whereby the average film thickness at a position of 170 mm from the upper end of the support is 15 μm. A charge transport layer was formed.
The following structural formula (2)

Charge transport material (hole transport material) represented by 70 parts polycarbonate resin 100 parts
(Iupilon Z400, manufactured by Mitsubishi Engineering Plastics)

Next, the following components were mixed with 20 parts of 1,1,2,2,3,3,4-heptafluorocyclopentane (trade name: Zeolora H, manufactured by Nippon Zeon Co., Ltd.) and 20 parts of 1-propanol. Dissolved in solvent.
Fluorine atom-containing resin 0.5 part
(Product name: GF-300, manufactured by Toagosei Co., Ltd.)
10 parts of tetrafluoroethylene resin powder (trade name: Lubron L-2, manufactured by Daikin Industries, Ltd.) was added to the solution in which the fluorine atom-containing resin was dissolved. Thereafter, the solution obtained by adding the tetrafluoroethylene resin powder was subjected to four treatments at a pressure of 600 kgf / cm 2 with a high-pressure disperser (trade name: Microfluidizer M-110EH, manufactured by Microfluidics, USA), and uniformly Dispersed. Further, the dispersion-treated solution was filtered with a polyflon filter (trade name: PF-040, manufactured by Advantech Toyo Co., Ltd.) to prepare a dispersion. Then, the following structural formula (3)

90 parts of a charge transport material (hole transport material), 70 parts of 1,1,2,2,3,3,4-heptafluorocyclopentane and 70 parts of 1-propanol were added to the dispersion. This was filtered with a polyflon filter (trade name: PF-020, manufactured by Advantech Toyo Co., Ltd.) to prepare a coating material for the second charge transport layer.

  The second charge transport layer coating material was applied onto the charge transport layer using the second charge transport layer coating material, and then dried in an oven at 50 ° C. for 10 minutes in the air. Thereafter, electron beam irradiation was carried out for 1.6 seconds in a nitrogen atmosphere while rotating the support at 200 rpm under conditions of an acceleration voltage of 150 kV and a beam current of 3.0 mA. Subsequently, the temperature around the support was raised from 25 ° C. to 125 ° C. over 30 seconds in a nitrogen atmosphere, and the curing reaction of the substance contained in the second charge transport layer was performed. In addition, when the absorbed dose of the electron beam at this time was measured, it was 15 kGy. The oxygen concentration in the electron beam irradiation and heat curing reaction atmosphere was 15 ppm or less. The support subjected to the above treatment is naturally cooled to 25 ° C. in the atmosphere, and then subjected to heat treatment in the atmosphere for 30 minutes in an oven heated to 100 ° C. A protective layer having an average film thickness of 5 μm was formed to obtain an electrophotographic photosensitive member.

  The electrophotographic photosensitive member produced by the above method was subjected to surface processing in a press-contact shape transfer processing apparatus using a mold shown in FIG. 8 to obtain a photosensitive member a. The temperature of the electrophotographic photosensitive member and the mold during processing was controlled at 110 ° C., and shape transfer was performed by rotating the photosensitive member in the circumferential direction while applying a pressure of 5 MPa. In FIG. 8, (1) shows the mold shape seen from above, and (2) shows the mold shape seen from the side. The mold shown in FIG. 8 has a cylindrical shape, the major axis diameter D is 1.0 μm, the height F is 3.0 μm, and the distance E between the molds is 1.0 μm.

  Surface observation was performed on the electrophotographic photosensitive member produced by the above method using an ultradeep shape measuring microscope VK-9500 (manufactured by Keyence Corporation). The electrophotographic photosensitive member to be measured was placed on a table that was processed so that the cylindrical support could be fixed, and the surface was observed at a position 170 mm away from the upper end of the electrophotographic photosensitive member. At that time, the objective lens magnification was set to 50 times, and the measurement was carried out by observing a 100 μm square of the surface of the photosensitive member as visual field observation. The concave portion observed in the measurement field was analyzed using an analysis program.

  The shape of the surface portion of each concave-shaped part in the measurement visual field, the average major axis diameter, and the number of concave-shaped parts in a 100 μm square were measured. It was confirmed that a cylindrical concave portion shown in FIG. 2A was formed on the surface of the electrophotographic photosensitive member. The average major axis diameter was 1.0 μm. Further, the number of concave portions in 100 μm square was 2500.

The electrophotographic photosensitive member produced by the above method was left in an environment having an ambient temperature of 23 ° C. and a relative humidity of 50% for 24 hours, and then the elastic deformation rate and universal hardness were measured. As a result, the elastic deformation rate value was 55% and the universal hardness value was 180 N / mm ² .

<Photoconductor Production Examples 2, 3, 4>
Photosensitive bodies b, c, and d were obtained in the same manner as in Photoconductor Production Example 1 except that the mold for surface processing in the press-contact shape transfer processing apparatus was changed. Table 1 shows the shape of the surface portion of the concave portion, the average major axis diameter, the number of concave portions in 100 μm square, the elastic deformation rate, and the universal hardness.

<Photoconductor Comparative Production Examples 1, 2, 3, 4, 5>
Photoreceptors e, f, g, h, i were obtained in the same manner as in Photoconductor Production Example 1 except that the mold at the time of surface processing in the pressure contact shape transfer processing apparatus was changed. Table 1 shows the shape of the surface portion of the concave portion, the average major axis diameter, the number of concave portions in 100 μm square, the elastic deformation rate, and the universal hardness.

<Example of toner particle production>
630 parts of ion-exchanged water and 485 parts by mass of a 0.1 mol / L Na ₃ PO ₄ aqueous solution were added to a 2 L four-necked flask equipped with a high-speed stirrer CLEARMIX (M Technique Co., Ltd.). The number of revolutions of CLEARMIX was set to 14,000 rpm and heated to 65 ° C. To this, 65 parts of a 1.0 mol / L CaCl ₂ aqueous solution was gradually added, and 10% hydrochloric acid was further added dropwise, and a pH = 5.8 containing a minute water-insoluble dispersant Ca ₃ (PO ₄ ) ₂ was added. An aqueous dispersion medium was prepared.
-Styrene monomer 180 parts-N-butyl acrylate monomer 20 parts-Carbon black 45 parts-Aluminum compound of 3,5-di-tert-butylsalicylic acid 1.3 parts Using the attritor for the above materials for 5 hours After preparing the mixture after dispersion, the following components were added to the mixture and further dispersed for 2 hours to prepare a monomer mixture.
Saturated polyester resin (monomer composition, polycondensate of propylene oxide modified bisphenol A and terephthalic acid)
(Acid value 8.8 mg KOH / g, peak molecular weight 12,500, weight average molecular weight 19500) 12 parts / ester wax (composition: behenyl behenate, molecular weight 11500) 20 parts Next, a polymerization initiator 2 was added to the monomer mixture. A polymerizable monomer composition was prepared by adding 5 parts of 2′-azobis (2,4-dimethylvaleronitrile), and then charged into an aqueous dispersion medium. Under a nitrogen atmosphere with an internal temperature of 70 ° C., 15, Granulated for 15 minutes at 000 rpm. Thereafter, the stirrer was replaced with a propeller stirrer, and polymerization was performed for 5 hours while maintaining at 70 ° C. while stirring at 50 rpm, and the internal temperature was raised to 80 ° C. for polymerization for 5 hours. After the polymerization was completed, the slurry was cooled and diluted hydrochloric acid was added to remove the dispersant. Further, it was washed with water, dried and classified to obtain toner particles a having a weight average particle diameter of 6.8 μm.

<Example of carrier production>
MnO and 20.0 mol%, MgO of 7.8mol%, _Fe 2 _{O 3} the 65.2Mol% and (manufactured by Fritsch Co.) 0.8 mol% wet ball mill to SrCO ₃ in 5 hours grinding, mixing, dried , Held at 920 ° C. for 1 hour, and pre-baked. This was pulverized with a wet ball mill for 7 hours to 3 μm or less. 5% by mass of a dispersant and a binder (polyvinyl alcohol) are added to this slurry, and then granulated and dried with a spray dryer (manufactured by Mitsubishi Chemical Corporation), and held in an electric furnace at 1200 ° C. for 4 hours to perform main firing. It was. Thereafter, it was crushed and further classified to obtain a carrier core material having a volume average particle diameter of 45.2 μm. Next, 100 parts by mass of straight silicone (KR255 manufactured by Shin-Etsu Chemical Co., Ltd.) and 5 parts by mass of a silane coupling agent (γ-aminopropylethoxysilane) are mixed with 300 parts by mass of xylene to form a carrier resin coating solution. It was. The carrier core material was coated and solvent-removed while stirring using a fluidized bed heated to 70 ° C. using this resin coating solution. Furthermore, using an oven, treat at 230 ° C. for 2.5 hours, disintegrate, classify with a sieve, loosen agglomerates, and then remove coarse particles over 200 mesh (75 μm openings). Carrier a was obtained.

<Example 1>
100 parts of untreated calcium carbonate (inorganic fine powder Aa) obtained by the carbon dioxide reaction method is placed in a closed high-speed stirrer and stirred. 12 parts of molten zinc stearate (stearic acid purity 98%) heated to 190 ° C. is sprayed into the stirrer. After spraying the entire amount of the treating agent, the inside of the stirrer was gradually cooled at a rate of 1.5 ° C./min with stirring and taken out to room temperature, and then crushed by a pin mill to obtain inorganic fine powder Ab. The characteristics of the inorganic fine powder Aa and the inorganic fine powder Ab are shown in Table 2.

100 parts of toner particles a, 1 part of inorganic fine powder Ab and alumina surface-treated with 10 parts of dimethyl silicone oil (number average particle diameter of primary particles is 15 nm, true density is 3.7 g / cm ³ , fine powder Ba ) 1 part of silica and surface treated with 7 parts of isobutyltrimethoxysilane (number average particle diameter of primary particles 50 nm, true density 1.9 g / cm ³ , inorganic fine powder Ca) 0.5 part Henschel Toner a was obtained by external addition with a mixer (FM10B, manufactured by Mitsui Miike Chemical Co., Ltd.) (rotation speed: 66 times / second, time: 3 minutes).

  Toner a and carrier a were mixed at a toner concentration of 8% to prepare a two-component developer.

  Next, the photoreceptor a was mounted on a modified machine (remodeled to a negatively charged type) of an electrophotographic copying machine iRC6800 manufactured by Canon Inc., and evaluated as follows.

First, in an environment of a temperature of 25 ° C./humidity of 60% RH, the electrophotographic photosensitive member has a dark part potential (Vd) of −700 V and a light part potential (Vl) of 0.3 g / cm ³ on the photosensitive member. The potential conditions were set so that the initial potential of the electrophotographic photosensitive member was adjusted.

  Next, a cleaning blade made of urethane rubber was set so that the contact angle was 26 ° and the contact pressure was 0.294 N / cm (30 g / cm) with respect to the surface of the electrophotographic photosensitive member.

  Using toner a as a replenisher, the following evaluation was performed with an output resolution of 600 dpi. The evaluation results are shown in Table 5.

[Image density stability]
In a temperature 25 ° C./humidity 60% RH environment, 25,000 A4 continuous prints were performed using a character chart with a print ratio of 6%. A black image was sampled on the 100th and 25,000th A4 continuous prints. The image density of the solid black portion of the 100th and 25,000th samples in evaluation mode 1 is measured (average of 9 points), and the difference is obtained. Density measurement was performed with a reflection densitometer RD918 (manufactured by Macbeth). This evaluation was performed three times, and the rank was determined from the average value. The ranking of evaluation was performed as follows.
Rank 5: Density difference less than 0.05 Rank 4: Density difference between 0.05 and less than 0.1 Rank 3: Density difference between 0.1 and less than 0.15 Rank 2: Density difference between 0.15 and less than 0.20 Rank 1 : Concentration difference of 0.20 or more

[Cleanability]
In order to evaluate the cleaning property, the fusion caused by the poor cleaning was evaluated. In an environment of temperature 25 ° C./humidity 3% RH, 25,000 A4 continuous prints were performed using a character chart with a printing ratio of 30%.

After the end of continuous printing, the surface of the photosensitive member is observed with a digital high vision microscope VQ-7000 (manufactured by Keyence Corporation) (magnification 300 times). The part where the fusion occurs in the visual field is marked, the area is obtained, and the area ratio where the fusion occurs in the visual field is obtained. This was observed over 20 fields of view on the entire surface of the photoreceptor, and the average value was defined as the fusion occurrence rate. This evaluation was performed three times, and the rank was determined from the average value. The ranking of evaluation was performed as follows.
Rank 5: Fusion rate 1% or less Rank 4: Fusion rate 1% or more and less than 5% Rank 3: Fusion rate 5% or more and less than 10% Rank 2: Fusion rate 10% or more and less than 15% Rank 1: Fusing rate 15% or more

[Transfer efficiency]
The transfer efficiency was measured at the 25,000th sheet of the image density stability evaluation.

[Generation of white spots]
In an environment of temperature 25 ° C./humidity 3% RH, 10,000 A4 continuous prints were performed using a character chart with a printing ratio of 15%. After the continuous printing, five solid black images (A3) were sampled.

On the solid black image, the number of white spots in a circle with a radius of 2.5 cm centered on a total of 9 points of 5 cm, 15 cm, 25 cm from the left end and 7 cm, 21 cm, 35 cm from the upper end was counted for each circle. The average number of white spots per circle was determined. Furthermore, the average in five sample images was calculated | required and the following ranking was performed.
Rank 5: No white spots Rank 4: Less than 1.0 Rank 3: 1.0 or more and less than 2.0 Rank 2: 2.0 or more and less than 5.0 Rank 1: 5.0 or more

<Inorganic fine powders Ac to Ax>
The external additives Ac and Af to An were prepared in the same manner as the inorganic fine powder Ab except that the treatment method was changed as follows. At was obtained as follows. Ae was not surface treated. Other inorganic fine powders were prepared in the same manner as the inorganic fine powder Ab, except that the base was changed as shown in Table 2.
Ac: Surface treatment of inorganic fine powder Aa is 10 parts of trimethylsilane. Af: Surface treatment of inorganic fine powder Aa is 6 parts of hexamethyldisilazane. Ag: Surface treatment agent of inorganic fine powder Aa is stearic acid: olein. Surface treatment using a calcium salt of a fatty acid having a mass ratio of acid = 70: 30 Ah: Calcium salt of a fatty acid having a mass ratio of stearic acid: oleic acid = 68: 32 as a surface treatment agent for inorganic fine powder Aa Ai: surface treated with calcium salt of octanoic acid as a surface treating agent for inorganic fine powder Aa Aj: surface treated with calcium salt of lauric acid as a surface treating agent for inorganic fine powder Aa Treated Ak: surface treated with a calcium salt of myristic acid as a surface treating agent for inorganic fine powder Aa Al: inorganic fine powder Surface treatment with behenic acid calcium salt as surface treatment agent for Aa Am: Surface treatment with calcium salt of montanic acid as surface treatment agent for inorganic fine powder Aa An: Surface treatment of inorganic fine powder Aa 100 parts of untreated calcium carbonate (inorganic fine powder Aa) obtained by the carbon dioxide reaction method was slurried and surface-treated with a calcium salt of melicic acid as an agent, and the slurry was solidified in a nitrogen atmosphere. The solution was placed in an aqueous solution in which 3% by mass of sodium stearate was dissolved. And stirring calcium sulfate aqueous solution was dripped, and the calcium stearate was deposited on the inorganic fine powder Aa surface. The slurry was washed repeatedly with pure water and then filtered with Nutsche, and the resulting cake was dried and surface-treated with calcium stearate.

<Examples 2-37>
A toner was prepared and evaluated in the same manner as in Example 1 except that the inorganic fine powder used was changed as shown in Table 5. The results are shown in Table 5. Details of the inorganic fine powders Aa to Ax, Ba to Bg, and Ca to Cf are shown in Tables 2, 3, and 4, respectively.

<Examples 38 to 40>
In Example 1, evaluation was performed in the same manner as in Example 1 except that instead of the photoreceptor a, the photoreceptor b, the photoreceptor c, and the photoreceptor d were used. The results are shown in Table 5.

<Comparative Examples 1-5>
In Example 1, evaluation was performed in the same manner as in Example 1 except that the photosensitive members e, f, g, h, and i were used instead of the photosensitive member a. The results are shown in Table 6.

<Comparative Examples 6-11>
A toner was prepared and evaluated in the same manner as in Example 1 except that the inorganic fine powder used was changed as shown in Table 6. The results are shown in Table 6.

Rpc Average major axis diameter Lpc Average minor axis diameter Rdv Depth a Laser light shielding part b Laser light transmitting part c Excimer laser light irradiator d Work rotating motor e Work moving device f Photosensitive body g Concave-shaped part non-forming part h Concave Shape part A Pressurizing device B Mold C Electrophotographic photosensitive member 1 Photosensitive member 2 Scorotron charger 3 Exposure device 4 Developing device 4a Developing sleeve 4b Toner coating blade 5 Developer 6 Transfer material 7 Corona charger 8 Cleaning blade 9a Primary transfer Roller 9b Intermediate transfer belt 10 Secondary transfer roller

Claims (7)

Charging the photoconductor, forming an electrostatic latent image on the charged photoconductor, developing the electrostatic latent image with toner to form a toner image on the photoconductor, and on the photoconductor An image forming method comprising a step of transferring a toner image to a transfer material, and a step of removing residual toner on the photoreceptor after the transfer step,
The photoreceptor has concave portions on the surface, and the number of the concave portions is 40 or more and 40,000 or less per 100 μm square, and the average major axis diameter of the opening of the concave portion is 0.5 μm or more and 15.0 μm or less. ,
The toner is a toner having toner particles having a colorant and a binder resin, and inorganic fine powder A,
The inorganic fine powder A is:
(1) The number average particle diameter of the primary particles is 80 nm or more and 200 nm or less,
(2) True density is 2.4 g / cm ³ or more and 3.0 g / cm ³ or less, measured using a powder fluidity analyzer, and (3) total energy TE is 2000 mJ at the seventh measurement after compression. Above 3200 mJ,
(4) The image forming method, wherein the flow velocity index FRI is 0.8 or more and 1.8 or less.   The image forming method according to claim 1, wherein the inorganic fine powder A is a metal carbonate.   The image forming method according to claim 1, wherein the inorganic fine powder A is calcium carbonate.   The inorganic fine powder A is a fatty acid or fatty acid selected from the group consisting of lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, montanic acid, and a salt of aluminum, zinc, calcium, magnesium, strontium of the fatty acid 4. The image forming method according to claim 1, wherein the surface treatment is performed with a metal salt.   4. The image forming method according to claim 1, wherein the inorganic fine powder A is surface-treated with a silane coupling agent. The toner has fine powder B having a number average particle size of primary particles of 3 nm to 25 nm and a true density of 0.5 g / cm ^{3 to} 4.5 g / cm ³ , and the addition of the inorganic fine powder A. the image forming method according to any one of claims 1 to 4, characterized in that the amount is less than 1.5 times 0.3 times the amount of the fine powder B. The toner has an inorganic fine powder C having a number average particle size of primary particles of 25 nm to 70 nm and a true density of 1.5 g / cm ^{3 to} 2.3 g / cm ³ . addition amount, the image forming method according to any one of claims 1 to 6, characterized in that said at most 80 mass% 20 mass% or more of the amount of the inorganic fine powder a.