JP2006084938A - Image forming apparatus and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus in which defective separation of transfer paper is solved, the defective separation being apt to occur when a toner image formed on a drum-shaped organic photoreceptor is transferred to transfer paper having elasticity satisfying a Clark stiffness of ≤30 cm<SP>3</SP>at a process speed of 200 mm/sec, further, the crack and wear flaw of the photoreceptor caused by damage to a pawl and defective transfer are prevented, and also, a satisfactory half-tone image can be formed, and to provide an image forming method using the image forming apparatus. <P>SOLUTION: The image forming apparatus includes: a transferring means of transferring a toner image formed on the surface of a drum-shaped organic photoreceptor onto transfer paper having a Clark stiffness of ≤30 cm<SP>3</SP>at a process speed of ≥200 mm/sec; and a separation pawl of separating the transfer paper, wherein the organic photoreceptor has surface properties satisfying the relation in the following general expression (1), and the separation pawl is composed of a member having a water absorption of <0.2%: general expression (1): 1.5≥B/A≥1.0; where A denotes the ratio between the elastic work done measured at an indentation load of 2 mN and the total work done, and B denotes the ratio between the elastic work done measured at an indentation load of 20 mN and the total work done. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention uses an image forming apparatus such as a copying machine, a printer, and a facsimile machine, which forms a toner image on the surface of an organic photoreceptor by electrophotography and transfers the toner image onto a transfer sheet, and the image forming apparatus. In particular, the present invention relates to an image forming apparatus and an image forming method for satisfactorily separating transfer paper from the surface of an organic photoreceptor.

  In recent years, organic photoreceptors have been widely used for electrophotographic photoreceptors. Organic photoreceptors have advantages over other photoreceptors, such as easy development of materials suitable for various exposure light sources from visible light to infrared light, the ability to select materials that are free from environmental pollution, and low manufacturing costs. However, the disadvantage is that the mechanical strength is weak and the surface of the photoreceptor is deteriorated or scratched when a large number of sheets are printed.

  In order to improve the mechanical strength and wear characteristics of such an organic photoreceptor, an organic photoreceptor having a surface layer of a siloxane-based resin layer has been developed (Patent Document 1). In addition, a technique in which an organic photoreceptor having the surface layer of the siloxane-based resin layer is applied to an image forming apparatus having a nail separation unit has been disclosed, and improvement of nail scratches and transfer paper separation failure has been reported (Patent Literature). 2).

  That is, in general, in reversal development used in digital image formation, the action of Coulomb force due to residual charges in the unexposed area is greater than in regular development. Therefore, after the transfer of the toner from the photoconductor to the transfer paper, the adhesion between the transfer paper and the photoconductor is high, and it becomes very difficult to separate the transfer paper from the photoconductor. It has been reported that separation means using a separation claw is effective for separating the transfer paper having high adhesion from the photoreceptor.

However, even when these techniques related to the organic photoreceptor of the improved siloxane resin layer are used, the degree of improvement in the occurrence of transfer paper separation failure and image defects due to claws is not sufficient. In particular, a toner image formed on a drum-shaped organic photoreceptor (hereinafter, the drum-shaped organic photoreceptor is simply referred to as an organic photoreceptor or a photoreceptor) is soft when the transfer paper has a Clark stiffness of 30 cm ³ or less. When transferring toner images to transfer paper at high speed using transfer paper, such soft transfer paper has high adhesion to a drum-shaped organic photoreceptor having a siloxane-based resin layer, resulting in poor separation. Cheap. In addition, the surface layer of the siloxane-based resin layer is generally improved in nail scratches by forming a cured film having a high elastic strength, but in order to improve the improvement degree of nail scratches, the elastic strength is increased. As the height is increased, the cured film becomes brittle and cracks are likely to occur at the contact portion of the nail, and as a result, image unevenness due to cracks is likely to occur.

On the other hand, if a cured film with a low elastic strength is used, the surface of the photoconductor tends to be subject to abrasion flaws due to separation nails. If the wear flaws increase, the halftone image deteriorates and a rough image is generated. There is a problem that the adhesion of the body surface is increased, winding occurs, and transfer paper separation failure (hereinafter also simply referred to as jam) is likely to occur.
Japanese Patent Laid-Open No. 2001-100447 JP 2001-255683 A

The present invention has been made to solve the above-described problems, that is, to solve the problem of transfer and separation of a toner image formed on a drum-shaped organic photoreceptor, and the process speed is improved. At 200 mm / sec, the toner image formed on the photosensitive drum on the drum is solved with the transfer paper separation failure that is likely to occur when the transfer paper has a Clark stiffness of 30 cm ³ or less and is transferred onto a soft transfer paper. Another object of the present invention is to provide an image forming apparatus capable of preventing cracks and abrasion scratches on a photoreceptor due to claw scratches and transfer defects and obtaining a good halftone image, and an image forming method using the image forming apparatus.

The present inventors have developed a toner image formed on a drum-shaped organic photoreceptor having a surface layer of a siloxane-based resin layer with a process speed of 200 mm / sec or more on a soft transfer paper having a Clark stiffness of 30 cm ³ or less. After the transfer, when separating the transfer paper using the nail separation means, the surface properties of the organic photoconductor, the characteristics of the separation nail and the characteristics of the toner adhering to the transfer paper were examined in detail. In order to improve the transfer paper separation performance by the nail, it is necessary to make the transfer paper easy to separate from the surface of the organophotoreceptor, and the surface physical properties that do not leave nail scratches and are less likely to cause cracks In addition, the present inventors have found that it is important to use a separation claw that does not easily adhere to the toner and a toner that does not adhere to the separation claw. That is, the present invention is configured by combining the surface properties of the siloxane-based resin layer within a range of specific elastic characteristics, and combining the separation claw that hardly adheres toner to the nail of the separating means and the toner that hardly adheres to the separation claw. As a result, the present invention was completed. The present invention is achieved by having any of the following configurations.
(Claim 1)
Transfer means for transferring a toner image formed on the surface of a drum-shaped organic photoconductor at a process speed of 200 mm / sec or more to a transfer paper having a Clark stiffness of 30 cm ³ or less, and separation for separating the transfer paper from the organic photoconductor In the image forming apparatus provided with a separation unit having a nail, the organic photoreceptor has a surface physical property having a relationship represented by the following general formula (1), and the water absorption rate of the separation nail is less than 0.2%: An image forming apparatus comprising:

General formula (1): 1.5 ≧ B / A ≧ 1.0
However,
A represents the ratio of elastic work (We2) and total work (Wt2) measured with an indentation load of 2 mN: We2 / Wt2,
B represents a ratio of elastic work (We20) and total work (Wt20) measured with an indentation load of 20 mN: We20 / Wt20.
(Claim 2)
The image forming apparatus according to claim 1, wherein the organic photoreceptor has a drum shape having an outer diameter of 40 to 240 mm.
(Claim 3)
The image forming apparatus according to claim 1, wherein at least a surface of the separation claw is a resin.
(Claim 4)
The image forming apparatus according to claim 1, wherein at least a part of the surface of the separation claw is a fluororesin.
(Claim 5)
The image forming apparatus according to claim 1, wherein the separating unit includes a unit in which the separating claw swings at a contact portion with the organic photoconductor.
(Claim 6)
The toner used to form a toner image on the organic photoreceptor has a particle size of 0.7 × (Dp50) or less and a number of 10% by number where the particle size of the toner particles is 50% (Dp50). The image forming apparatus according to claim 1, wherein:
(Claim 7)
The toner used to form a toner image on the organic photoreceptor has a ratio (Dv50 / Dp50) of 50% volume particle size (Dv50) to 50% number particle size (Dp50) of the toner particles of 1.0 to 1.0. 1.15: The ratio (Dv75 / Dp75) of 75% cumulative volume particle size (Dv75) from the larger volume particle size to 75% cumulative particle size (Dp75) from the larger number particle size is 1. The image forming apparatus according to claim 1, wherein the number of particles having a particle size of 0 to 1.20 and a particle size of 0.7 × (Dp50) or less is 10 number% or less.
(Claim 8)
The image forming apparatus according to claim 6, wherein the 50% volume particle size (Dv50) is 2 to 9 μm.
(Claim 9)
The image forming apparatus according to claim 6, wherein the toner is a polymerized toner.
(Claim 10)
The image forming apparatus according to claim 9, wherein a saturated water content of the polymerized toner in an environment of 30 ° C. and 80 RH% is 0.1 to 2.5% by mass.
(Claim 11)
The image forming apparatus according to claim 1, wherein the surface layer of the organic photoreceptor is a siloxane-based resin layer having a crosslinked structure.
(Claim 12)
A transfer step of transferring a toner image formed on the surface of a drum-shaped organic photoconductor at a process speed of 200 mm / sec or more onto a transfer paper having a Clark stiffness of 30 cm ³ or less, and a separation for separating the transfer paper from the organic photoconductor In the image forming method of preparing an electrophotographic image including a separation step having a nail, the organophotoreceptor has a surface property having a relationship represented by the following general formula (1), and the water absorption rate of the separation nail is 0. An image forming method comprising a member of less than 2%.

General formula (1): 1.5 ≧ B / A ≧ 1.0
However,
A represents the ratio of elastic work (We2) and total work (Wt2) measured with an indentation load of 2 mN: We2 / Wt2,
B represents a ratio of elastic work (We20) and total work (Wt20) measured with an indentation load of 20 mN: We20 / Wt20.

By using the image forming apparatus and the image forming method of the present invention, when a transfer paper having a Clark stiffness of 30 cm ³ or less is used, it is possible to prevent the transfer paper from being wrapped around the organic photoreceptor, and the transfer paper is separated by a separation claw. Can prevent image deterioration due to cracks and abrasion scratches on organic photoreceptors that tend to occur at the same time, and at the same time, can achieve good transfer paper transfer properties, and can provide highly reliable and high-quality electrophotographic images. .

The separation means according to the present invention uses a separation claw made of a member having at least a surface water absorption of less than 0.2% in order to separate transfer paper having a Clark stiffness of 30 cm ³ or less from the drum-shaped organic photoreceptor. That is, the transfer paper that is soft to contact with the drum-shaped organic photoreceptor is separated by a separation claw made of a member having a water absorption rate of less than 0.2%. By using a separation claw made of a member having a water absorption rate of 0.2% or more, the toner easily adheres to the separation claw, the adhesion between the separation claw and the photosensitive member is lowered, and the transfer paper is wound around the photosensitive member, thereby jamming. Is likely to occur. In addition, the photoconductor is easily scratched. In particular, when the water absorption rate of the separation nail is 0.2% or more, toner containing a large amount of fine particle components easily adheres to the separation nail, and the adhered toner causes jam due to poor separation of transfer paper. And scratches on the photoreceptor. More preferably, the water absorption of the separation claw is less than 0.15%.

  The separation claw having a water absorption rate of less than 0.2% may be a separation claw formed entirely of a metal member such as stainless steel or cemented carbide, but the organic photoreceptor of the present invention is more scratched. A metal member in which the surface of a resin claw or a metal member formed of a resin such as plastic that is difficult to be coated with a resin is preferable.

  For example, as a resin nail of a plastic material, a polyimide resin having a low water absorption rate, a polyamideimide resin having a low water absorption rate, or the like is used. Moreover, what processed the resin on the surface of the separation claw of stainless steel is preferably used for this invention. In order to reduce the friction coefficient between the separation claw and the organic photoconductor and suppress damage due to abrasion of the separation claw and contact with the organic photoconductor, it is preferable to provide a coating of a fluororesin on the surface of the separation claw . By providing a coating of fluororesin, the coefficient of friction with the transfer paper is also reduced, which is effective for improving the guide property of the transfer paper and for contamination due to toner particles, paper dust, and the like. As the fluorine-based resin, polyterola fluoroethylene (PTFE), tetrafluoropolyethylene resin or the like is used, and a stainless steel separation claw portion is preferably sintered and coated. This sintered coating is sufficiently effective only by the surface coating on the tip of the separation claw.

Measurement condition of water absorption rate of separation nail After leaving a sample to be measured (0.2 to 1 g) in an environment of 30 ° C. and 80% RH for 48 hours, a moisture measuring device (Karl Fischer method) manufactured by Mitsubishi Chemical Corporation was used. To measure. Other devices may be used as long as they are devices that measure by the Karl Fischer method. In the case where the separation claw is coated with a fluorine resin or the like, the measurement is performed by removing the coated portion.

  Next, an image forming apparatus using the separating means of the present invention will be described. FIG. 1 is a block diagram showing an example of an image forming apparatus according to the present invention, to which a digital electrophotographic system is applied.

  The image forming apparatus 1 in FIG. 1 is provided with a charging unit 3, a writing unit 4, a developing unit 5, a transfer unit 6, a neutralizing unit 7, a separating unit 10, and a cleaning unit 8 at the peripheral portion of the rotating organic photoreceptor 2. Then, after the surface of the organic photoreceptor 2 is uniformly charged by the charging unit 3, a latent image is formed by performing light irradiation based on image data read from the original by the laser of the writing unit 4, and the latent image Is reversely developed by the developing means 5 to which a bias is applied to form a toner image on the surface of the organic photoreceptor 2.

  On the other hand, the transfer paper (toner image support material such as paper or transparent sheet) P fed from the transfer paper storage means 13 is sent to the transfer position, and the toner image is transferred to the transfer paper by the transfer means 6 at the transfer position. Transferred onto P. Thereafter, the charge on the transfer paper P is erased by the charge eliminating means 7, separated from the organic photoreceptor 2 by the separating means 10, conveyed by the intermediate conveying section 9, and subsequently heated and fixed by the fixing means 11. 12 is discharged. On the other hand, the developer remaining on the surface of the organic photoreceptor 2 is removed downstream of the separating unit 10 by the cleaning blade 80 of the cleaning unit 8 to prepare for the next image formation.

The present invention prevents wrapping around a drum-shaped organic photoconductor that is easy to generate on a transfer paper having a crack stiffness of 30 cm ³ or less on the transfer paper, and causes jamming, generation of cracks on the surface of the photoconductor, and generation of scratches. The purpose of this is to prevent image degradation caused by. The definition and measurement method defined in (JIS P 8143) is used for the Clark stiffness of the transfer paper. The Clark stiffness at which the effect of the present invention is most prominent is preferably 25 cm ³ or less. The lower limit of the Clark stiffness is not particularly limited, but is generally preferably 5 cm ³ or more, more preferably 8 or more. The Clark stiffness can be adjusted by changing the basis weight and thickness of the transfer paper, the orientation of pulp fibers in the transfer paper, and the like.

  In the present invention, the separation means of the separation claw comprising the organic photoreceptor 2 having a physical property of the relationship of the general formula (1) and a member having a water absorption of less than 0.2% is used.

  FIG. 2 is a configuration diagram of the separating means 10 provided with the separating claws 101 used in the present invention.

  In the separating means 10 in FIG. 2, 101 is a separation claw, 103 is a claw pressing spring for abutting the separation claw 101 on the organic photoreceptor 2, 102 is a release plate for releasing the abutment of the separation claw 101, 104 is A rotation shaft 105 for rotating the separation claw 101 to abut or release the separation claw 101, and a support member 105 for supporting each member.

  FIG. 3 shows the shape of the separation claw 101. In FIG. 3A, the tip is flat when viewed from the top and bottom surfaces, and is in surface contact with the organic photoreceptor 2. In FIG. 3B, the tip is sharp when viewed from the top, but is planar, and when viewed from the bottom, the tip is sharp and has a ridge line, and the tip is a triangular pyramid shape. It has become. The organic photoconductor 2 is in surface contact with a surface narrower than the above (A), and the guide portion for guiding the transfer paper P is a ridgeline and is in line contact. FIG. 3C shows a quadrangular pyramid shape with a sharp tip and a ridge line when viewed from the top and bottom surfaces. The contact with the organic photoconductor 2 is a line contact state almost similar to a point contact, and the transfer paper P is also in line contact as in the case of (B). When the above three types of shapes were examined in the present invention, a favorable result was obtained that the organic photoconductor 2 was less likely to be worn in the pyramid shape of (C).

  FIG. 4 is a diagram for explaining the contact condition when the separation claw 101 is in contact with the organic photoreceptor 2.

  In FIG. 4, the separation claw 101 is a contact portion (upper side of the side view in FIG. 3) that contacts the organic photoreceptor 2, and a guide portion (FIG. 3 in the side view in FIG. a is an angle formed by the tangent line of the organic photoconductor 2 at the contact point where the tip of the separation claw 101 is in contact with the organic photoconductor 2 and the contact portion of the separation claw 101. b is an angle formed between the tangent line of the organic photoconductor 2 at the contact point where the tip of the separation claw 101 is in contact with the organic photoconductor 2 and the guide portion of the separation claw 101. c is a perpendicular line drawn from the center of the organic photoconductor 2 to the conveyance path of the transfer paper P to the organic photoconductor 2 and a straight line passing through the organic photoconductor 2 from the position where the tip of the separation claw 101 is in contact. It is an angle to make. d is a straight line passing through the center of the organic photosensitive member 2 parallel to the conveyance path of the transfer paper P to the organic photosensitive member 2 and the contact point where the tip of the separation claw 101 is in contact with the organic photosensitive member 2. The angle formed with the tangent line is positive with respect to a straight line passing through the center of the organic photoconductor 2 parallel to the transport path, and negative with respect to a line formed on the upper side. The d can also be obtained from the equation “bc”. In the present invention, a is also referred to as a contact angle and d is also referred to as a rake angle.

  The guide portion of the separation claw 101 is conventionally linear, but it is preferable to bend it so that it is guided at a different angle from the middle of the guide portion so that the transfer of the transfer paper P after separation is good. . The angle to be changed may be changed so that the transfer direction of the transfer paper P is below a straight line passing through the center of the organic photoreceptor 2 parallel to the transport path with the organic photoreceptor 2 described above. It is preferable that the transfer paper P after being guided by the separation claw 101 is promptly and reliably guided to the subsequent intermediate transport section to prevent transport failure.

  Further, by providing a bent guide portion, the separation performance can be improved even when the rake angle of the separation claw 101 is a negative angle of 0 ° or less, and the transfer paper P after separation can be guided well. preferable. It is preferable in terms of transportability that the change in the guide direction is a direction in which the separated transfer paper P is guided downward.

  The contact angle a of the separation claw 101 to the organic photoreceptor 2 of the present invention is preferably 5 to 25 degrees because the separation property of the transfer paper P can be further improved. If the angle is less than 5 degrees, poor separation of the transfer paper P is likely to occur. If the angle exceeds 25 degrees, damage due to wear on the surface of the organic photoreceptor 2 is likely to be promoted, and the durability of the organic photoreceptor 2 is likely to deteriorate. Become.

  The rake angle d of the separation claw 101 with respect to the organic photoreceptor 2 of the present invention is −3 degrees to −10 degrees, which prevents the separation claw 101 from being deformed due to the abutment of the transfer paper P and improves the separability. This is preferable. When it exceeds −3 degrees, the separation claw 101 is easily deformed due to an increase in force caused by the contact of the transfer paper P with the separation claw 101. If it is less than −10 degrees, conveyance failure of the transfer paper P after separation tends to occur.

  The contact of the separation claw 101 with the organic photoreceptor 2 is preferably performed by applying a load to the separation claw 101 by an elastic member. The separation claw 101 may bounce on the organic photoreceptor 2 due to a slight difference in the friction coefficient on the surface of the organic photoreceptor 2. If the transfer paper P happens to come at this time, the transfer paper P is below the separation claw 101. May incur a separation failure, and this bounce phenomenon can be eliminated. As the elastic member, a metal spring is preferable, and in this embodiment, the claw pressing spring 103 corresponds. When such a claw pressing spring is used, claw scratches and cracks are likely to occur in the organic photoreceptor, but when the organic photoreceptor having the characteristic of the general formula (1) of the present invention is used. Generation of these claws and cracks can be prevented, and image deterioration can be prevented. The contact of the separation claw 101 with the organic photoreceptor 2 can be performed only when the transfer paper P is sent. When the transfer paper P does not need to be separated, the contact of the separation claw 101 can be released. As described above, it is preferable to provide a release member in order to suppress damage to the organic photoreceptor 2 to a minimum and to significantly improve durability. In the present embodiment, the release plate 102 corresponds to the release member.

  The separation claw 101 is preferably swung with respect to the organic photoreceptor 2. As a mechanism for swinging the separation claw 101, a known mechanism may be used. By swinging the separation claw 101 on the organic photoreceptor 2, the separation claw 101 is not brought into contact only with the same circumferential position of the organic photoreceptor 2, and the organic photoreceptor is caused by friction between the organic photoreceptor 2 and the separation claw 101. The local damage on the surface 2 can be eliminated, and the durability of the organic photoreceptor 2 can be further improved.

  The image forming apparatus having the separation claw of the present invention is particularly effective when it is operated at a process speed (photosensitive member moving speed (rotational speed) of 200 mm / sec or more (forms an electrophotographic image)). In other words, a photoconductor that moves at high speed is likely to be cracked or worn by the separation claw, and is likely to cause poor separation of the transfer paper. However, an image using the combination of the photoconductor of the present invention with toner and the separation claw. The forming apparatus can prevent cracks and wear scratches, and can also significantly improve transfer paper separation.

  Next, the organic photoreceptor of the present invention will be described.

  The organophotoreceptor of the present invention is characterized by having the relationship of the general formula (1), but the elastic work (We2, We20) and the total work (Wt2, Wt20) of the general formula (1) are It represents the work function value of plastic deformation and elastic deformation for a constant load indenter (total load is 2 mN or 20 mN) weighted from the surface of the photoreceptor.

  Below, the measurement conditions of elastic work (We2, We20) and total work (Wt2, Wt20) are described.

Equipment used: Fischer scope H100V (microhardness measuring device), manufactured by Fischer Instruments Co., Ltd. Working indenter: Diamond Vickers indenter Load condition: Surface of organic photoreceptor at a speed of 0.2 mN / sec or 2.0 mN / sec Push in the Vickers indenter from the load time: 10 sec
Unloading conditions: Remove the load at the same speed as the load Measurement sample As in the case of the above photoreceptor, an intermediate layer, a charge generation layer, a first charge transport layer, and a second charge transport layer are provided on an aluminum plate and dried under the same conditions. The sample prepared was fixed to an H100V machine, and a Vickers indenter was pushed in perpendicular to the sample for measurement.

  The measurement is performed by the procedure of indenter load (10 sec) and unloading.

  An example of work function measurement data measured under the above conditions is illustrated in FIG.

  As the load on the horizontal axis in FIG. 5 increases, the amount of deformation on the vertical axis increases. When the load is stopped at point A and the accumulated load is gradually removed, the amount of deformation gradually decreases. The shaded portion (E region) is the elastic work amount, and the sum of the shaded portion and the horizontal line portion (V region) is the total work amount.

In the present invention, as described above, the ratio of the elastic work (We2) and the total work (Wt2) measured with an indentation load of 2 mN (total load is 2 mN): A = We2 / Wt2,
Ratio of elastic work (We20) and total work (Wt20) measured at an indentation load of 20 mN (total load is 20 mN): When B = We20 / Wt20, the following general formula (1) between A and B It has the relationship of these.

General formula (1): 1.5 ≧ B / A ≧ 1.0
The organophotoreceptor of the present invention has the above-mentioned relationship. By using the organophotoreceptor with the separation means having the separation pawl of the present invention, the generation of scratches and cracks due to the separation pawl is prevented, and the halftone image is deteriorated. It is possible to prevent streak-like image defects, reliably achieve transfer paper separation, and obtain a good electrophotographic image.

  On the other hand, if B / A is larger than 1.5, the surface of the photoconductor is easily cracked by rubbing with the separation claw, etc., and the toner easily adheres to the crack portion. As a result, the separation claw cannot be in close contact with the photosensitive surface. , Prone to separation failure of transfer paper. A more preferable range of B / A is 1.05 or more and 1.45 or less.

  Also, if B / A is less than 1.0, scratches due to the separation nails are likely to occur, and toner fine particle components adhere to the scratch areas, hindering the adhesion of the separation nails to the photoreceptor, and separating the transfer paper. Prone to defects.

  Further, We2, Wt2, We20, and Wt20 each preferably have the following ranges.

0.02 ≦ We2 ≦ 0.4 0.1 ≦ Wt2 ≦ 0.6
1 ≦ We20 ≦ 40 5 ≦ Wt20 ≦ 60
When We2 is smaller than 0.02 or We20 is smaller than 1, scratches due to the separation claw are likely to occur, and the halftone image is deteriorated, and the fine particle component of the toner adheres to the scratched part, resulting in poor separation. Likely to happen.

  When We2 is larger than 0.4 or We20 is larger than 40, cracks are likely to occur due to rubbing with a separation claw, and the crack portion tends to cause streak-like image defects.

  When Wt2 is smaller than 0.1 or Wt20 is smaller than 5, scratches due to the separation nails are likely to occur, and the halftone image is deteriorated. It is difficult to adhere to the photoconductor, and transfer paper is likely to be poorly separated.

  If Wt2 is greater than 0.6 or Wt20 is greater than 60, cracks are likely to occur due to rubbing with a separation claw, etc., and the cracks are likely to cause streak-like image defects, and transfer paper separation defects occur. It's easy to do.

  The organophotoreceptor having surface physical properties of the general formula (1) used in the present invention comprises a surface layer of the organophotoreceptor composed of a siloxane-based resin layer having a crosslinked structure, and production of the siloxane-based resin layer. The hydrolyzable organosilicon compound used in the above is used in a proportion of 50 parts by mass to 200 parts by mass with respect to 100 parts by mass of the difunctional component and 100 parts by mass of the bifunctional component, and non-hydrolysis of the hydrolyzable organosilicon compound A highly elastic siloxane-based resin layer obtained by drying and curing at 120 to 150 degrees using a long-chain alkyl group or glycidyl alkyl group having 3 or more carbon atoms as a degradable group (a substituent that does not cause hydrolysis) Is preferably formed.

  A representative example of the hydrolyzable organosilicon compound is an organosilicon compound represented by the following general formula (2). A siloxane-based resin layer having a crosslinked structure can be formed by applying and drying a coating composition using these compounds as raw materials. These raw materials form a condensate (oligomer) of an organosilicon compound in a solvent by hydrolysis in a hydrophilic solvent and subsequent condensation reaction. By applying and drying these coating compositions, a resin layer containing a siloxane resin having a three-dimensional network structure can be formed.

General formula (2)
(R) _n -Si- (X) _4-n
In the formula, Si represents a silicon atom, R represents an organic group in which carbon is directly bonded to the silicon atom, X represents a hydroxyl group or a hydrolyzable group, and n represents an integer of 0 to 3.

  In the organosilicon compound represented by the general formula (2), examples of the organic group in which carbon is directly bonded to silicon represented by R include alkyl groups such as methyl, ethyl, propyl, and butyl, phenyl, tolyl, naphthyl, Aryl groups such as biphenyl, epoxy-containing groups such as γ-glycidoxypropyl, β- (3,4-epoxycyclohexyl) ethyl, (meth) acryloyl groups such as γ-acryloxypropyl, γ-methacryloxypropyl, Hydroxyl groups such as γ-hydroxypropyl and 2,3-dihydroxypropyloxypropyl, vinyl-containing groups such as vinyl and propenyl, mercapto groups such as γ-mercaptopropyl, γ-aminopropyl, N-β (aminoethyl)- Amino-containing groups such as γ-aminopropyl, γ-chloropropyl, 1,1,1-trifluoropropyl, nonaf Orohekishiru, halogen-containing groups such as perfluorooctylethyl, other nitro, and cyano-substituted alkyl group. In particular, alkyl groups such as methyl, ethyl, propyl and butyl are preferred. Examples of the hydrolyzable group for X include alkoxy groups such as methoxy and ethoxy, halogen groups, and acyloxy groups. In particular, an alkoxy group having 6 or less carbon atoms is preferable.

  In the case of a specific compound of an organosilicon compound represented by the general formula (2) and n is 2 or more, a plurality of R may be the same or different. Similarly, when n is 2 or less, the plurality of Xs may be the same or different. Moreover, when using 2 or more types of organosilicon compounds represented by General formula (2), R and X may be the same between each compound, and may differ.

  In order to obtain an organophotoreceptor having surface physical properties related to the general formula (1), among the organosilicon compounds represented by the general formula (2), at least two or more of two functional groups and three or more functional groups are contained. It is preferable to use a compound having a long-chain alkyl group having 3 or more carbon atoms or a glycidylalkyl group in the non-hydrolyzable group described above as a kind of trifunctional component.

  The resin layer may be formed by adding colloidal silica to a composition containing the organosilicon compound or a hydrolysis condensate thereof. Colloidal silica is silicon dioxide particles colloidally dispersed in a dispersion medium, but colloidal silica may be added at any stage of the coating liquid composition preparation. Colloidal silica may be added in the form of an aqueous or alcoholic sol, or an aerosol produced in the gas phase may be directly dispersed in the coating solution of the present invention.

  In addition, metal oxides such as titania and alumina may be added in the form of sol or particle dispersion.

  Colloidal silica and the tetrafunctional (n = 0) or trifunctional (n = 1) organosilicon compound give the resin layer film of the present invention elasticity and rigidity by forming a crosslinked structure. When the ratio of the bifunctional organosilicon compound (n = 2) increases, the viscosity increases and the hydrophobicity increases. The monofunctional organosilicon compound (n = 3) does not become a polymer but reacts with unreacted residual SiOH groups. It works to increase hydrophobicity.

  In addition, the siloxane-based resin layer having the cross-linked structure is prepared by using a reactive charge transporting raw compound having reactivity with the silicon compound together with the silicon compound, so that the partial structure of the charge-transporting group is formed in the siloxane-based resin layer. It is preferable to impart charge transportability to the siloxane-based resin layer. Examples of the reactive charge transporting compound include compounds having the following structure.

  The surface layer preferably contains an antioxidant. By containing an antioxidant, it is possible to reduce the time-dependent change in the surface properties of the general formula (1), maintain stable surface properties, and prevent changes in sensitivity and residual potential. The antioxidant preferably used for this invention is illustrated below.

  Under the surface layer, a known organic photoreceptor layer structure can be used. That is, an organic photoreceptor in which an intermediate layer or the like is provided on a conductive support made of an aluminum-based alloy material and a photosensitive layer is provided thereon if necessary. The photosensitive layer may be a single-layer type photosensitive layer having a single layer structure for charge generation and charge transport. More preferably, a charge transport layer is formed on the charge generation layer to form a charge generation function and a charge transport function. A function-separated type organic photoreceptor in which is separated from each other is preferred.

  Here, the organic photoconductor of the present invention means an electrophotographic photoconductor constituted by providing an organic compound with at least one of a charge generation function and a charge transport function essential to the configuration of the electrophotographic photoconductor. In addition, all known organic electrophotographic photoreceptors such as a photoreceptor composed of a known organic charge generating material or an organic charge transport material, a photoreceptor composed of a polymer complex with a charge generation function and a charge transport function are contained.

  The conductive support, charge generation layer, charge transport layer and the like will be described in more detail.

As the conductive support of the organic photoreceptor of the present invention,
1) A metal plate such as an aluminum plate or a stainless steel plate 2) A thin metal layer such as aluminum, palladium or gold provided on a support such as paper or plastic film by laminating or vapor deposition 3) Paper or plastic film Examples of the material of the conductive support used in the present invention in which a layer of a conductive compound such as a conductive polymer, indium oxide, and tin oxide is provided on the support by coating or vapor deposition are mainly aluminum, A metal material such as copper, brass, steel, stainless steel, or other plastic material formed into a belt shape or a drum shape is used. Among them, aluminum excellent in cost, workability, and the like is preferably used, and a thin cylindrical aluminum base tube that is usually extruded or pultruded is often used. In addition, the conductive support may have a sealed anodized film formed on the surface thereof.

  In the organic photoreceptor of the present invention, an intermediate layer, a charge generation layer and a charge transport layer are preferably laminated on a conductive support.

  The intermediate layer is required to have a blocking layer that can enhance the adhesion between the conductive support and the photosensitive layer and at the same time prevent injection of charge carriers from the conductive support. As the intermediate layer, an undercoat layer using a polyamide resin or an intermediate layer in which metal oxide particles are dispersed in a binder resin such as polyamide is used. Examples of the intermediate layer preferably used in the present invention include an intermediate layer formed by dispersing surface-treated titanium oxide particles in a polyamide resin. The film thickness of the intermediate layer depends on the composition of the intermediate layer, but is preferably in the range of 0.3 μm to 10 μm.

  The charge generation layer has a function of generating charge carriers by image exposure. Examples of the charge generation material (CGM) contained in the charge generation layer include phthalocyanine pigments, polycyclic quinone pigments, azo pigments, perylene pigments, indigo pigments, quinacridone pigments, azurenium pigments, squarylium dyes, cyanine dyes, pyrylium dyes, Examples thereof include thiopyrylium dyes, xanthene dyes, triphenylmethane dyes, styryl dyes, and the like. These charge generation materials (CGM) are formed in a layer alone or together with an appropriate binder resin.

  The charge transport layer has a function of accepting injection of charge carriers generated in the charge generation layer and moving the charge carriers to the surface of the photoreceptor. Examples of the charge transport material (CTM) contained in the charge transport layer include oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidazolone derivatives, imidazoline derivatives, bisimidazolidine derivatives, styryl. Compound, hydrazone compound, benzidine compound, pyrazoline derivative, stilbene compound, amine derivative, oxazolone derivative, benzothiazole derivative, benzimidazole derivative, quinazoline derivative, benzofuran derivative, acridine derivative, phenazine derivative, aminostilbene derivative, poly-N-vinylcarbazole , Poly-1-vinylpyrene, poly-9-vinylanthracene, and the like. These charge transport materials (CTM) are usually combined with a binder. Layer formation is performed.

  The binder resin contained in the charge generation layer (CGL) and the charge transport layer (CTL) includes polycarbonate resin, polyester resin, polystyrene resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, and polyvinyl butyral resin. , Polyvinyl acetate resin, styrene-butadiene resin, vinylidene chloride-acrylonitrile copolymer resin, vinyl chloride-maleic anhydride copolymer resin, urethane resin, silicone resin, epoxy resin, silicone-alkyd resin, phenol resin, polysilane resin, Examples thereof include polyvinyl carbazole.

  The ratio of the charge generation material to the binder resin in the charge generation layer is preferably 1:10 to 10: 1 by mass ratio. The film thickness of the charge generation layer is preferably 5 μm or less, particularly preferably 0.05 to 2 μm.

  The charge transport layer is formed by dissolving the charge transport material and the binder resin in a suitable solvent, and coating and drying the solution. The mixing ratio of the charge transport material and the binder resin is preferably 10: 1 to 1:10 by mass ratio.

  The thickness of the charge transport layer is usually 5 to 50 μm, particularly preferably 10 to 40 μm. When a plurality of charge transport layers are provided, the thickness of the upper layer of the charge transport layer is preferably 10 μm or less and smaller than the total thickness of the charge transport layer provided under the upper layer of the charge transport layer. It is preferable.

  The organophotoreceptor of the present invention is preferably formed by laminating the siloxane resin layer on the charge generation layer and the charge transport layer.

  Next, as a coating processing method for producing the photoreceptor used in the present invention, a coating processing method such as dip coating, spray coating, circular amount regulation type coating, etc. is used, but coating processing on the resin layer side of the photosensitive layer. In order to prevent the lower layer film from being dissolved as much as possible, it is preferable to use a coating method such as spray coating or circular amount regulation type (a typical example is a circular slide hopper type) in order to achieve uniform coating processing. The spray coating is described in detail in, for example, JP-A-3-90250 and JP-A-3-269238, and the circular amount-regulating coating is described in detail in, for example, JP-A-58-189061. Yes.

  The photoreceptor used in the present invention is preferably heat-dried at a temperature of 50 ° C. or more, preferably 60 to 200 ° C. after the siloxane-based resin layer is formed by coating. By this heat drying, an organic photoreceptor having the above-mentioned surface physical properties can be produced while reducing the remaining coating solvent.

  The toner according to the image forming apparatus of the present invention will be described.

  On the other hand, the developing means of the image forming apparatus of the present invention contains at least colored particles composed of a resin and a colorant, and when the 50% number particle size is (Dp50), the particle size is 0.7 × (Dp50) or less. It is preferable that the toner contains 10% or less of toner.

  That is, in the present invention, the surface property of the separation unit of the separation claw comprising the organic photoreceptor 2 having the relationship of the general formula (1) and a member having a water absorption of less than 0.2% is used, and the development unit By using a toner having a particle size of 0.7 × (Dp50) or less and 10% by number or less, the synergistic effect of the present invention can be exhibited.

  The toner with a small particle size easily adheres to the separation nail, easily adheres to the surface of the separation nail, generates toner filming, reduces the adhesion of the separation nail to the photoreceptor, and improves the separation characteristics of recording materials such as paper. It tends to deteriorate and jam. In the present invention, the water absorption rate of the separation claw is reduced, and the toner component having a fine particle diameter that easily adheres to the separation claw is reduced to prevent toner filming on the surface of the separation claw. By using the separation claw for the organic photoreceptor having the above characteristics, it is possible to prevent the occurrence of poor separation (jam) of the recording material from the photoreceptor and to provide a highly reliable image forming apparatus.

  In addition, the present inventors have reduced the amount of small particle size components with high adhesion as toner used in this image forming method, and at the same time, 50% particles, which is the median value of the toner particle size of all toners. Focusing on the diameter, in analyzing the small particle size component deviating from the particle size, the cumulative 75% from the large particle diameter side of the toner to the large particle diameter side of the toner. Focusing on the frequency particle size, it was found that a toner having the following particle size distribution is suitable.

  That is, the ratio (Dv50 / Dp50) of 50% volume particle size (Dv50) to 50% number particle size (Dp50) is 1.0 to 1.15, and the cumulative 75% volume particle size from the larger volume particle size ( Dv75) and the ratio (Dv75 / Dp75) of the cumulative 75% number particle size (Dp75) from the larger number particle size is 1.0 to 1.20, and the particle size is 0.7 × (Dp50) By using toner having a particle size distribution of 10% by number or less in the developing means of the present invention, toner adhesion to the separation claw described above is prevented, transfer paper separation failure is prevented, and dot reproduction is performed. An electrophotographic image having good properties and sharpness can be obtained.

  In order to obtain a toner having the above characteristics, there is a method of classifying and preparing a toner by a conventional kneading and pulverizing method. In order to achieve such a particle size distribution with good reproducibility, a polymerization toner by a polymerization method is used. Is preferably used.

  The term “polymerized toner” means a toner obtained by forming a resin for a toner binder and forming the toner shape by polymerization of a raw material monomer for the binder resin and, if necessary, subsequent chemical treatment. More specifically, it means a toner obtained through a polymerization reaction such as suspension polymerization or emulsion polymerization and, if necessary, a subsequent step of fusing particles.

  First, the volume particle size, the number particle size, and the ratio between the volume particle size and the number particle size of the toner according to the present invention will be described.

  From the viewpoint of obtaining the effects described in the present invention, the toner according to the present invention is preferably monodispersed as a particle size distribution, and the ratio of 50% volume particle size (Dv50) to 50% number particle size (Dp50) ( Dv50 / Dp50) needs to be 1.0 to 1.15, but is preferably 1.0 to 1.13.

  In order to suppress the fluctuation range of transferability and developability, the ratio (Dv75 / Dp75) of the cumulative 75% volume particle size (Dv75) to 75% number particle size (Dp75) from the larger toner is 1. Although it is necessary to be from 1.0 to 1.20, it is preferably from 1.1 to 1.19. Further, in all the toners, the number of toners having a particle size of 0.7 × (Dp50) or less needs to be 10% by number or less, preferably 5% to 9% by number.

  The toner according to the present invention has a 50% volume particle size (Dv50) of preferably 2 μm to 8 μm, more preferably 3 μm to 7 μm. The 50% number particle size (Dp50) of the toner according to the present invention is preferably 2 μm to 7.5 μm, and more preferably 2.5 μm to 7 μm. By setting it as this range, the effect of this invention can be exhibited more notably.

  Here, the cumulative 75% volume particle diameter (Dv75) or the cumulative 75% number particle diameter (Dp75) from the larger one is the sum of the frequencies from the larger particle diameter and the sum of the total volume or the sum of the numbers. On the other hand, each is represented by a volume particle size or a number particle size of a particle size distribution portion showing 75%.

  In the present invention, 50% volume particle size (Dv50), 50% number particle size (Dp50), cumulative 75% volume particle size (Dv75), cumulative 75% number particle size (Dp75) and the like are Coulter Counter TA-II type Alternatively, it can be measured with a Coulter Multisizer (manufactured by Coulter).

  The components of the toner according to the present invention, the components of the binder resin that is a component of the toner, and the production thereof will be described.

  The toner according to the present invention contains at least a colorant, a binder resin, and the like. The toner may be manufactured through a pulverization / classification process, and is obtained by polymerizing a polymerizable monomer as shown below. The toner particles may be produced by a so-called polymerization method in which a toner is produced using the resin particles. When a toner is produced using a polymerization method, a production method having a step of salting out / fusing resin particles is particularly preferable.

  As the polymerizable monomer used in the polymerization method, a radical polymerizable monomer can be used as a constituent component, and a crosslinking agent can be used as necessary. Moreover, it is preferable to contain at least one radical polymerizable monomer having the following acidic group or radical polymerizable monomer having a basic group.

(1) Radical polymerizable monomer The radical polymerizable monomer component is not particularly limited, and a conventionally known radical polymerizable monomer can be used. Moreover, it can be used combining 1 type (s) or 2 or more types so that the required characteristic may be satisfy | filled.

  Specifically, aromatic vinyl monomers, (meth) acrylic acid ester monomers, vinyl ester monomers, vinyl ether monomers, monoolefin monomers, diolefin monomers And halogenated olefin monomers.

  Examples of the aromatic vinyl monomer include styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, p-methoxy styrene, p-phenyl styrene, p-chloro styrene, p-ethyl styrene, p. -N-butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, 2, Examples thereof include styrene monomers such as 4-dimethylstyrene and 3,4-dichlorostyrene and derivatives thereof.

  Examples of (meth) acrylic acid ester monomers include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, and methacrylic acid. Examples include butyl, hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, propyl γ-aminoacrylate, stearyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and the like.

  Examples of vinyl ester monomers include vinyl acetate, vinyl propionate, and vinyl benzoate.

  Examples of the vinyl ether monomer include vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl phenyl ether and the like.

  Examples of the monoolefin monomer include ethylene, propylene, isobutylene, 1-butene, 1-pentene, 4-methyl-1-pentene and the like.

  Examples of the diolefin monomer include butadiene, isoprene, chloroprene and the like.

  Examples of the halogenated olefin monomer include vinyl chloride, vinylidene chloride, vinyl bromide and the like.

(2) Crosslinking agent As the crosslinking agent, a radical polymerizable crosslinking agent may be added to improve the properties of the toner. Examples of the radical polymerizable crosslinking agent include those having two or more unsaturated bonds such as divinylbenzene, divinylnaphthalene, divinyl ether, diethylene glycol methacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, and diallyl phthalate.

(3) Radical polymerizable monomer having an acidic group or radical polymerizable monomer having a basic group As the radical polymerizable monomer having an acidic group or the radical polymerizable monomer having a basic group, For example, a polymerizable monomer having a carboxyl group, a polymerizable monomer having a sulfonic acid group, a primary amine, a secondary amine, a tertiary amine, a quaternary ammonium salt, or other amine-based polymerizability Monomer.

  Examples of the polymerizable monomer having a carboxyl group include acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, cinnamic acid, maleic acid monobutyl ester, maleic acid monooctyl ester and the like.

  Examples of the polymerizable monomer having a sulfonic acid group include styrene sulfonic acid, allyl sulfosuccinic acid, octyl allyl sulfosuccinate and the like.

  These may have a structure of an alkali metal salt such as sodium or potassium or an alkaline earth metal salt such as calcium.

  Examples of the radical polymerizable monomer having a basic group include amine compounds, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, and quaternary ammonium salts of the above four compounds, 3-dimethylaminophenyl acrylate, 2-hydroxy-3-methacryloxypropyltrimethylammonium salt, acrylamide, N-butylacrylamide, N, N-dibutylacrylamide, piperidylacrylamide, methacrylamide, N-butylmethacrylamide, N-octadecylacrylamide Vinyl pyridine, vinyl pyrrolidone; vinyl N-methylpyridinium chloride, vinyl N-ethylpyridinium chloride, N, N-diary Ammonium chloride, N, N-diallyl-ethyl ammonium chloride, and the like.

  As the radical polymerizable monomer used in the present invention, a radical polymerizable monomer having an acidic group or a radical polymerizable monomer having a basic group is used in an amount of 0.1 to 15% by mass based on the whole monomer. The radical polymerizable crosslinking agent is preferably used in the range of 0.1 to 10% by mass with respect to the total radical polymerizable monomer, although it depends on its properties.

[Chain transfer agent]
For the purpose of adjusting the molecular weight, a commonly used chain transfer agent can be used. The chain transfer agent is not particularly limited, and for example, octyl mercaptan, dodecyl mercaptan, tert-dodecyl mercaptan, n-octyl-3-mercaptopropionic acid ester, carbon tetrabromide and styrene dimer are used.

(Polymerization initiator)
The radical polymerization initiator used in the present invention can be appropriately used as long as it is water-soluble. For example, persulfates (potassium persulfate, ammonium persulfate, etc.), azo compounds (4,4′-azobis-4-cyanovaleric acid and its salts, 2,2′-azobis (2-amidinopropane) salts, etc.), peroxides Compounds and the like.

  Furthermore, the radical polymerization initiator can be combined with a reducing agent as necessary to form a redox initiator. By using a redox initiator, the polymerization activity is increased, the polymerization temperature is lowered, and the polymerization time can be further shortened.

  The polymerization temperature may be any temperature as long as it is equal to or higher than the lowest radical generation temperature of the polymerization initiator, but for example, a range of 50 ° C. to 90 ° C. is used. However, it is possible to perform polymerization at room temperature or higher by using a polymerization initiator that starts at room temperature, for example, a combination of hydrogen peroxide and a reducing agent (ascorbic acid or the like).

[Surfactant]
In order to perform polymerization using the above-mentioned radical polymerizable monomer, it is necessary to perform oil droplet dispersion in an aqueous medium using a surfactant. Although it does not specifically limit as surfactant which can be used in this case, The following ionic surfactant can be mentioned as an example of a suitable thing.

  Examples of the ionic surfactant include sulfonates (sodium dodecylbenzenesulfonate, sodium arylalkylpolyethersulfonate, 3,3-disulfonediphenylurea-4,4-diazo-bis-amino-8-naphthol-6 Sodium sulfonate, ortho-carboxybenzene-azo-dimethylaniline, 2,2,5,5-tetramethyl-triphenylmethane-4,4-diazo-bis-β-naphthol-6-sodium sulfonate, etc.), sulfuric acid Ester salts (sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, etc.), fatty acid salts (sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, potassium stearate) Beam, calcium oleate and the like).

  Nonionic surfactants can also be used. Specifically, polyethylene oxide, polypropylene oxide, combination of polypropylene oxide and polyethylene oxide, ester of polyethylene glycol and higher fatty acid, alkylphenol polyethylene oxide, ester of higher fatty acid and polyethylene glycol, ester of higher fatty acid and polypropylene oxide, sorbitan ester Etc.

  In the present invention, these are mainly used as an emulsifier at the time of emulsion polymerization, but may be used for other processes or purposes.

[Colorant]
Examples of the colorant include inorganic pigments, organic pigments, and dyes.

  A conventionally well-known thing can be used as an inorganic pigment. Specific inorganic pigments are exemplified below.

  Examples of the black pigment include carbon black such as furnace black, channel black, acetylene black, thermal black, and lamp black, and magnetic powder such as magnetite and ferrite.

  These inorganic pigments can be used alone or in combination as required. Moreover, the addition amount of a pigment is 2-20 mass% with respect to a polymer, Preferably 3-15 mass% is selected.

  When used as a magnetic toner, the above-mentioned magnetite can be added. In this case, it is preferable to add 20 to 60% by mass in the toner from the viewpoint of imparting predetermined magnetic properties.

  Conventionally known organic pigments and dyes can also be used. Specific organic pigments and dyes are exemplified below.

  Examples of pigments for magenta or red include C.I. I. Pigment red 2, C.I. I. Pigment red 3, C.I. I. Pigment red 5, C.I. I. Pigment red 6, C.I. I. Pigment red 7, C.I. I. Pigment red 15, C.I. I. Pigment red 16, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 53: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 123, C.I. I. Pigment red 139, C.I. I. Pigment red 144, C.I. I. Pigment red 149, C.I. I. Pigment red 166, C.I. I. Pigment red 177, C.I. I. Pigment red 178, C.I. I. And CI Pigment Red 222.

  Examples of the orange or yellow pigment include C.I. I. Pigment orange 31, C.I. I. Pigment orange 43, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 15, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. Pigment yellow 138, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 185, C.I. I. Pigment yellow 155, C.I. I. Pigment yellow 156, and the like.

  Examples of pigments for green or cyan include C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 2, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 16, C.I. I. Pigment blue 60, C.I. I. And CI Pigment Green 7.

  As the dye, C.I. I. Solvent Red 1, 49, 52, 58, 63, 111, 122, C.I. I. Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162, C.I. I. Solvent Blue 25, 36, 60, 70, 93, 95 etc. can be used, and a mixture thereof can also be used.

  These organic pigments and dyes can be used alone or in combination as desired. Moreover, the addition amount of a pigment is 2-20 mass% with respect to a polymer, Preferably 3-15 mass% is selected.

  The colorant can also be used after surface modification. As the surface modifier, conventionally known ones can be used, and specifically, silane coupling agents, titanium coupling agents, aluminum coupling agents and the like can be preferably used.

  The toner according to the present invention may be used in combination with a release agent. For example, low molecular weight polyolefin waxes such as polypropylene and polyethylene, paraffin wax, Fischer-Tropsch wax, ester wax and the like can be used as the release agent. Moreover, in this invention, the ester wax shown by following General formula (3) can be used preferably.

General formula (3)
R _1- (OCO-R ₂ ) _n
In the formula, n represents an integer of 1 to 4, preferably 2 to 4, more preferably 3 to 4, and particularly preferably 4.

R ₁ and R ₂ represent a hydrocarbon group which may have a substituent.

R ₁ : carbon number = 1-40, preferably 1-20, more preferably 2-5
R ₂ : carbon number = 1-40, preferably 13-29, more preferably 12-25
Specific examples of the crystalline compound having an ester group according to the present invention are shown below, but the present invention is not limited thereto.

  These ester waxes are contained in resin particles and have a function of imparting good fixability (adhesiveness to an image support) to a toner obtained by fusing resin particles.

  The addition amount of the release agent used in the present invention is preferably 1% by mass to 30% by mass, more preferably 2% by mass to 20% by mass, and further preferably 3% by mass to 15% by mass with respect to the whole toner. Further, the toner of the present invention is an ester compound as described above as a release agent in resin particles in which the release agent dissolved in the polymerizable monomer is dispersed in water and polymerized. A toner prepared by a step of forming particles encapsulating and salting out and fusing together with colorant particles is preferable.

  The toner according to the present invention may contain materials capable of imparting various functions as toner materials in addition to the colorant and the release agent. Specific examples include charge control agents. These components can be added simultaneously with the resin particles and the colorant particles in the salting out / fusion step described above, and can be added by various methods such as a method included in the toner and a method of adding to the resin particles themselves.

  Similarly, various known charge control agents and those that can be dispersed in water can be used. Specific examples include nigrosine dyes, naphthenic acid or higher fatty acid metal salts, alkoxylated amines, quaternary ammonium salt compounds, azo metal complexes, salicylic acid metal salts or metal complexes thereof.

  The external additive used for the toner according to the present invention will be described.

  The toner according to the present invention can be used by adding a so-called external additive for the purpose of improving fluidity, chargeability and cleaning property. These external additives are not particularly limited, but various inorganic fine particles, organic fine particles and lubricants can be used.

  A conventionally well-known thing can be used as an inorganic fine particle. Specifically, silica, titanium, alumina fine particles and the like can be preferably used. These inorganic fine particles are preferably hydrophobic. Specifically, as silica fine particles, for example, commercially available products R-805, R-976, R-974, R-972, R-812, R-809 manufactured by Nippon Aerosil Co., Ltd., HVK-2150, H manufactured by Hoechst -200, commercially available products TS-720, TS-530, TS-610, H-5, MS-5 and the like manufactured by Cabot Corporation.

  Examples of the titanium fine particles include commercially available products T-805 and T-604 manufactured by Nippon Aerosil Co., Ltd., commercially available products MT-100S, MT-100B, MT-500BS, MT-600, MT-600SS, and JA- 1. Commercial products TA-300SI, TA-500, TAF-130, TAF-510, TAF-510T manufactured by Fuji Titanium Co., Ltd. Commercial products IT-S, IT-OA, IT-OB, IT- manufactured by Idemitsu Kosan Co., Ltd. OC etc. are mentioned.

  Examples of the alumina fine particles include commercial products RFY-C and C-604 manufactured by Nippon Aerosil Co., Ltd. and commercial products TTO-55 manufactured by Ishihara Sangyo Co., Ltd.

  As the organic fine particles, spherical organic fine particles having a number average primary particle diameter of about 10 to 2000 nm can be used. As this, a homopolymer such as styrene or methyl methacrylate or a copolymer thereof can be used.

  Examples of lubricants include, for example, zinc stearate, aluminum, copper, magnesium, calcium, etc., zinc oleate, manganese, iron, copper, magnesium, etc., zinc palmitate, copper, magnesium, calcium, etc. And salts of higher fatty acids such as zinc of linoleic acid, salts of calcium, etc., zinc of ricinoleic acid, salts of calcium, etc.

  The amount of these external additives added is preferably 0.1 to 5% by mass with respect to the toner.

  Examples of the method for adding the external additive include various known mixing apparatuses such as a Turbuler mixer, a Henschel mixer, a Nauter mixer, and a V-type mixer.

  A method for producing an electrostatic charge image developing toner according to the present invention will be described.

"Manufacturing process"
In the toner of the present invention, a polymerizable monomer or a polymerizable monomer solution as described above in which a release agent is dissolved is dispersed in an aqueous medium, and then resin particles encapsulating the release agent are obtained by a polymerization method. A step of preparing, a step of fusing resin particles in an aqueous medium using the resin particle dispersion, a washing step of filtering the obtained particles from an aqueous medium to remove a surfactant, and the like. It is preferable to produce by a polymerization method comprising a drying step and an external additive addition step of adding an external additive to particles obtained by drying. Here, the resin particles may be colored particles. In addition, non-colored particles can also be used as resin particles. In this case, colored particles are formed by adding a colorant particle dispersion or the like to the resin particle dispersion and then fusing it in an aqueous medium. Can do.

  In particular, the method of fusing is preferably a method of salting out / fusing using resin particles produced by the polymerization step. When non-colored resin particles are used, the resin particles and the colorant particles can be salted out / fused in an aqueous medium.

  In addition to the colorant and the release agent, a charge control agent that is a component of the toner can be added as particles in this step.

  In addition, an aqueous medium here consists of water as a main component, and shows content whose water content is 50 mass% or more. Examples of substances other than water include organic solvents that dissolve in water, such as methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran. Alcohol organic solvents such as methanol, ethanol, isopropanol, and butanol, which are preferably organic solvents that do not dissolve the resin, are particularly preferable.

  As a preferable polymerization method in the present invention, a monomer solution in which a release agent is dissolved in a monomer is dispersed in an aqueous medium in which a surfactant having a critical micelle concentration or less is dissolved, and dispersed in oil droplets by mechanical energy. And a method of radical polymerization by adding a water-soluble polymerization initiator. In this case, an oil-soluble polymerization initiator may be added to the monomer.

  The disperser for performing the oil droplet dispersion is not particularly limited, and examples thereof include CLEARMIX, ultrasonic disperser, mechanical homogenizer, manton gourin, pressure homogenizer, and the like.

  The colorant itself may be used after surface modification. In the surface modification method of the colorant, the colorant is dispersed in a solvent, and after the surface modifier is added therein, the temperature is raised and the reaction is performed. After completion of the reaction, the mixture is filtered, washed with the same solvent, repeatedly filtered and dried to obtain a pigment treated with a surface modifier.

  There is a method in which the colorant particles are prepared by dispersing a colorant in an aqueous medium. This dispersion is preferably performed in a state where the surfactant concentration in water is equal to or higher than the critical micelle concentration (CMC).

  The disperser at the time of pigment dispersion is not particularly limited, but preferably a medium such as CLEARMIX, ultrasonic disperser, mechanical homogenizer, pressure disperser such as Manton Gorin or pressure homogenizer, sand grinder, Getzmann mill, diamond fine mill, etc. Type disperser.

  As the surfactant used here, the aforementioned surfactants can be used.

  In the step of salting out / fusion, a salting-out agent composed of an alkali metal salt or an alkaline earth metal salt is added as a flocculant having a critical coagulation concentration or more in water in which resin particles and colorant particles are present. Next, it is a step of performing fusion at the same time as salting-out proceeds by heating the resin particles to a temperature higher than the glass transition point.

  Here, the alkali metal salt and the alkaline earth metal salt which are salting-out agents include lithium, potassium, sodium and the like as the alkali metal, and examples of the alkaline earth metal include magnesium, calcium, strontium and barium. Preferably, potassium, sodium, magnesium, calcium, and barium are used. Examples of the salt include chlorine salt, bromine salt, iodine salt, carbonate salt, sulfate salt and the like.

  The method for achieving the toner particle size distribution is not particularly limited, but for example, a method such as control by classification or the like, temperature or time at the time of association, and control of a stopping method for terminating the association are used. can do.

  As a particularly preferable production method, a method of controlling the association time in water, the association temperature, the stopping speed, and the like can be mentioned. That is, in the case of performing salting out / fusion, it is preferable to make the time allowed to stand after adding the salting-out agent as short as possible. The reason for this is not clear, but there are problems that the aggregation state of the particles fluctuates depending on the standing time after salting out, the particle size distribution becomes unstable, and the surface property of the fused toner fluctuates. appear. The temperature at which the salting-out agent is added is not particularly limited.

  In the present invention, it is preferable to use a method in which the dispersion of the resin particles is heated as quickly as possible and heated to the glass transition temperature or more of the resin particles. The time until this temperature rise is less than 30 minutes, preferably less than 10 minutes. Further, although it is necessary to quickly raise the temperature, the rate of temperature rise is preferably 1 ° C./min or more. The upper limit is not particularly clear, but is preferably 15 ° C./min or less from the viewpoint of suppressing the generation of coarse particles due to rapid progress of salting out / fusion. As a particularly preferred embodiment, there can be mentioned a method in which salting-out / fusion is continued even when the glass transition temperature is reached. By adopting this method, the fusion can be effectively advanced as the particles grow, and the durability as a final toner can be improved.

  Furthermore, it is possible to control the particle size in particular by salting out / fusion using a divalent metal salt at the time of association. Although the reason for this is not clear, the use of a divalent metal salt increases the repulsive force during salting out, making it possible to effectively suppress the dispersibility of the surfactant, resulting in an exile distribution. It is estimated that it became possible to control.

  Moreover, it is preferable to add a monovalent metal salt and water in order to stop the salting out / fusion. By adding this, salting out can be stopped, and as a result, the presence of large particle size components and small particle size components can be suppressed.

  For polymerized toners that associate or fuse resin particles in an aqueous medium, by controlling the flow and temperature distribution of the medium in the reaction vessel in the fusing step, the heating temperature is further increased in the shape control step after fusing. The shape distribution and shape of the entire toner can be arbitrarily changed by controlling the number of rotations of stirring and time.

  That is, in the polymerization method toner that associates or fuses the resin particles, the flow in the reaction apparatus is made into a laminar flow, and the agitation step and the agitation tank that can make the internal temperature distribution uniform are used. By controlling the temperature, the number of rotations, and the time in the shape control step, the toner having the shape factor and uniform shape distribution of the present invention can be formed. The reason for this is that if the laminar flow is fused in a place where the laminar flow is formed, strong stress is not applied to the particles (aggregation or agglomerated particles) in which aggregation and fusion proceed, and in laminar flow where the flow is accelerated As a result of the uniform temperature distribution in the stirring tank, the shape distribution of the fused particles is estimated to be uniform. Further, the fused particles gradually become spherical by heating and stirring in the subsequent shape control step, and the shape of the toner particles can be arbitrarily controlled.

  In order to control the toner of the present invention to a predetermined shape, it is preferable that salting-out and fusion are simultaneously performed. In the method of heating after forming the agglomerated particles, the shape tends to be distributed, and the generation of fine particles cannot be suppressed. That is, since the aggregated particles are heated while being stirred in the aqueous medium, it is presumed that the aggregated particles are repartitioned and a component having a small particle size is likely to be generated.

  Polymerized toners are generally produced in an aqueous medium (an aqueous solvent such as water), so the water content of the toner tends to increase. However, a toner having a high water content tends to adhere to the separation claw of the present invention. As a result, the separation claw is less likely to be in close contact with the photosensitive member, and the separation property of the transfer paper is likely to deteriorate. The polymerized toner used in the present invention preferably has a saturated water content of 0.3 to 2.5% by mass in a 30 ° C./80% RH environment. In order to reduce the saturated water content to less than 0.3% by mass with a polymerized toner, the cost required for this is too high, which is not practical. On the other hand, if the saturated water content is larger than 2.5% by mass, the toner easily adheres to the separation claw as described above, and as a result, the separation claw becomes difficult to adhere to the photoconductor, and the separation property of the transfer paper is deteriorated. Cheap.

  In the present invention, the saturated water content in the 30 ° C./80% RH environment of the polymerized toner is preferably suppressed to 0.3 to 2.5% by mass. A specific method for adjusting the water content of the polymerized toner will be described below. To do.

  As a result of studying the above problems and advancing researches, the present inventors have conducted a primary drying of a water-containing cake of colored particles obtained by forming particles in an aqueous medium to a water content of 5% by mass or less (high temperature After drying to high humidity (measured samples stored in an environment of 30 ° C. and 80% RH), the water content contained in the colored particles is 0.3 to 2.5% by mass (high temperature and high humidity ( It has been found that the toner can be obtained by measuring a sample stored in an environment of 30 ° C. and 80% RH).

  Specifically, the colored particles formed in the aqueous medium are colored particles before the strong particles are formed on the surface layer of the colored particles at a temperature at which the colored particles are not welded to form a lump. When the moisture content is also removed from the center of the glass and dried (primary drying) until the water content becomes 5% by mass or less (30 ° C., 80% RH), then after drying (secondary drying), coloring occurs. It has been found that the water content contained in the particles can be 0.3-2.5% by mass (30 ° C., 80% RH).

  However, the colored particles formed in the aqueous medium may be subjected to primary drying in a state where the water content in the colored particles exceeds 5% by mass (30 ° C., 80% RH), and then secondary drying may be performed. It is difficult to make the water content contained in the colored particles 0.3 to 2.5% by mass (30 ° C., 80% RH).

  The reason is not clear, but if a strong coating is formed on the surface of the colored particles with a high water content in the primary drying, the strong coating formed on the surface of the colored particles even if the secondary drying is performed. Reduced to 0.3 to 2.5% by mass (30 ° C., 80% RH), because it is difficult for water to flow from the center of the colored particles, and the saturated water content contained in the colored particles is reduced by 0.3 to 2.5% by mass (30 ° C. and 80% RH). Is estimated to be difficult.

<Saturated water content of toner>
Here, the saturated water content of the toner in the environment of 30 ° C. and 80% RH of the present invention is the value of the saturated water content (mass%) contained in the colored particles (toner) determined by the Karl Fischer method. It can measure using apparatus "AQS-724" (made by Hiranuma Sangyo Co., Ltd.). Specifically, the measurement sample (colored particles) in an opened state is left in an environment of 30 ° C. and 80% RH for 48 hours or more, and then saturated with the moisture content measurement device in a measurement room at room temperature and humidity. Measure the amount of water.

  The developer used in the present invention will be described.

  When used as a two-component developer by mixing with a carrier, as the carrier magnetic particles, conventionally known materials such as metals such as iron, ferrite, magnetite, and alloys of these metals with metals such as aluminum and lead Can be used. Ferrite particles are particularly preferable. The magnetic particles preferably have a volume average particle size of 15 to 100 μm, more preferably 25 to 80 μm.

  The volume average particle diameter of the carrier can be typically measured by a laser diffraction particle size distribution measuring apparatus “HELOS” (manufactured by SYMPATEC) equipped with a wet disperser.

  The carrier is preferably a carrier in which magnetic particles are further coated with a resin, or a so-called resin dispersion type carrier in which magnetic particles are dispersed in a resin. The resin composition for coating is not particularly limited, and for example, olefin resin, styrene resin, styrene-acrylic resin, silicone resin, ester resin, or fluorine-containing polymer resin is used. In addition, the resin for constituting the resin-dispersed carrier is not particularly limited, and a known resin can be used. For example, a styrene-acrylic resin, a polyester resin, a fluorine resin, a phenol resin, or the like is used. be able to.

Example 1
Production of photoconductor (production of photoconductor 1)
Intermediate layer 60 g of polyamide resin (Amilan CM-8000: manufactured by Toray Industries, Inc.) was dissolved and dispersed in 1600 ml of methanol to prepare an intermediate layer composition solution, and immersed on a washed cylindrical aluminum substrate (diameter: 80 mm). It apply | coated by the apply | coating method and formed the intermediate | middle layer with a film thickness of 0.3 micrometer.

Charge generation layer 60 g of Y-type titanyl phthalocyanine and 700 g of a silicone resin solution (KR5240, 15% xylene-butanol solution: manufactured by Shin-Etsu Chemical Co., Ltd.) are mixed with a coating composition solution of 2000 ml of 2-butanone, and a sand mill is used. For 10 hours to prepare a charge generation layer coating solution. This charge generation layer coating solution was applied onto the intermediate layer by a dip coating method to form a charge generation layer having a thickness of 0.2 μm.

Charge transport layer 200 g of charge transport material (4-methoxy-4 ′-(4-methyl-α-phenylstyryl) triphenylamine), 300 g of bisphenol Z-type polycarbonate (Iupilon Z300: manufactured by Mitsubishi Gas Chemical Company), A charge transport layer coating solution was prepared by mixing and dissolving 2000 ml of 1,2-dichloroethane. This charge transport coating solution was applied onto the charge generation layer by a dip coating method to form a charge transport layer having a thickness of 20 μm.

Surface layer 59 g of γ-glycidoxypropyl and 32 g of dimethoxysilane were dissolved in 35 g of ethanol to obtain a uniform solution. To this, 26 g of dihydroxymethyltriphenylamine (Exemplary Compound T-1), an antioxidant (Exemplary Compound 2-1), and 1 g of aluminum chelate (Aluminum Chelate A (W): manufactured by Kawaken Chemical Co., Ltd.) were added and mixed. This solution was applied on the charge transport layer as a surface layer having a dry film thickness of 3 μm, and heat-cured at 120 ° C. for 1 hour to prepare the photoreceptor 1 of the present invention.

(Preparation of photoconductor 2)
Photoconductor 2 was prepared in the same manner except that the surface layer of photoconductor 1 was changed as follows.

A uniform solution was prepared by dissolving 46 g of γ-glycidoxypropyl and 45 g of dimethoxysilane in 35 g of ethanol. To this, 26 g of dihydroxymethyltriphenylamine (Exemplary Compound T-1), an antioxidant (Exemplary Compound 2-1), and 1 g of aluminum chelate (Aluminum Chelate A (W): manufactured by Kawaken Chemical Co., Ltd.) were added and mixed. This solution was applied on the charge transport layer as a surface layer having a dry film thickness of 3 μm, and heat-cured at 120 ° C. for 1 hour to prepare the photoreceptor 2 of the present invention.
Production of Photoreceptor (3) Photoreceptor 3 was produced in the same manner except that the surface layer of photoreceptor 1 was changed as follows.

A uniform solution was prepared by dissolving 32 g of γ-glycidoxypropyl and 58 g of dimethoxysilane in 35 g of ethanol. To this, 26 g of dihydroxymethyltriphenylamine (Exemplary Compound T-1), an antioxidant (Exemplary Compound 2-1), and 1 g of aluminum chelate (Aluminum Chelate A (W): manufactured by Kawaken Chemical Co., Ltd.) were added and mixed. This solution was applied as a surface layer having a dry film thickness of 3 μm on the charge transport layer, followed by heat curing at 120 ° C. for 1 hour to prepare the photoreceptor 3 of the present invention.
Production of Photoreceptor (4) Photoreceptor 4 was produced in the same manner except that the surface layer of photoreceptor 1 was changed as follows.

59 g of γ-glycidoxypropyl and 32 g of dimethoxysilane were dissolved in 35 g of ethanol to obtain a uniform solution. To this, 26 g of dihydroxymethyltriphenylamine (Exemplary Compound T-1), an antioxidant (Exemplary Compound 2-1), and 1 g of aluminum chelate (Aluminum Chelate A (W): manufactured by Kawaken Chemical Co., Ltd.) were added and mixed. This solution was applied onto the charge transport layer as a surface layer having a dry film thickness of 3 μm, and heat-cured at 130 ° C. for 1 hour to produce the photoreceptor 4 of the present invention.
Production of Photoreceptor (5) Photoreceptor 5 was produced in the same manner except that the surface layer of photoreceptor 1 was changed as follows.

59 g of γ-glycidoxypropyl and 32 g of dimethoxysilane were dissolved in 35 g of ethanol to obtain a uniform solution. To this, 26 g of dihydroxymethyltriphenylamine (Exemplary Compound T-1), an antioxidant (Exemplary Compound 2-1), and 1 g of aluminum chelate (Aluminum Chelate A (W): manufactured by Kawaken Chemical Co., Ltd.) were added and mixed. This solution was applied on the charge transport layer as a surface layer having a dry film thickness of 3 μm, and heat-cured at 150 ° C. for 1 hour to prepare the photoreceptor 5 of the present invention.
Production of Photoreceptor (6) Photoreceptor 6 was produced in the same manner except that the surface layer of photoreceptor 1 was changed as follows.

5 g of γ-glycidoxypropyl, 50 g of silicate (M silicate 51: manufactured by Tama Chemical Co., Ltd.) and 32 g of dimethoxysilane were dissolved in 35 g of ethanol to obtain a uniform solution. To this, 26 g of dihydroxymethyltriphenylamine (Exemplary Compound T-1), an antioxidant (Exemplary Compound 2-1), and 1 g of aluminum chelate (Aluminum Chelate A (W): manufactured by Kawaken Chemical Co., Ltd.) were added and mixed. This solution was applied on the charge transport layer as a surface layer having a dry film thickness of 3 μm, and heat-cured at 150 ° C. for 1 hour to prepare the photoreceptor 6 of the present invention.
Production of Photoreceptor (7) Photoreceptor 7 was produced in the same manner except that the surface layer of photoreceptor 1 was changed as follows.

69 g of γ-glycidoxypropyl and 21 g of dimethoxysilane were dissolved in 35 g of ethanol to obtain a uniform solution. To this, 26 g of dihydroxymethyltriphenylamine (Exemplary Compound T-1), an antioxidant (Exemplary Compound 2-1), and 1 g of aluminum chelate (Aluminum Chelate A (W): manufactured by Kawaken Chemical Co., Ltd.) were added and mixed. This solution was applied on the charge transport layer as a surface layer having a dry film thickness of 3 μm, and heat-cured at 120 ° C. for 1 hour to prepare the photoreceptor 7 of the present invention.
Production of Photoreceptor (8) Photoreceptor 8 was produced in the same manner except that the surface layer of photoreceptor 1 was changed as follows.

  A uniform solution was prepared by dissolving 23 g of γ-glycidoxypropyl and 66 g of dimethoxysilane in 35 g of ethanol. To this, 26 g of dihydroxymethyltriphenylamine (Exemplary Compound T-1), an antioxidant (Exemplary Compound 2-1), and 1 g of aluminum chelate (Aluminum Chelate A (W): manufactured by Kawaken Chemical Co., Ltd.) were added and mixed. This solution was applied on the charge transport layer as a surface layer having a dry film thickness of 3 μm, and heat-cured at 120 ° C. for 1 hour to prepare the photoreceptor 8 of the present invention.

  For each of the photoreceptors 1 to 8, the elastic work (We2, We20) and the total work (Wt2, Wt20) were measured under the measurement conditions described above. The results are shown in Table 1.

  Next, a toner used in the present invention and a developer using the toner were prepared.

<Developer>
<< Manufacture of latex 1 >>
A solution prepared by dissolving 7.08 g of an anionic active agent (sodium dodecylbenzenesulfonate: SDS) in ion-exchanged water (2760 g) in a 5000 ml separable flask equipped with a stirrer, temperature sensor, condenser, and nitrogen introducing device. Add. The internal temperature was raised to 80 ° C. while stirring at a stirring speed of 230 rpm under a nitrogen stream. On the other hand, 72.0 g of Exemplified Compound 19) was added to a monomer composed of 115.1 g of styrene, 42.0 g of n-butyl acrylate, and 10.9 g of methacrylic acid, and heated to 80 ° C. and dissolved to prepare a monomer solution. Here, the above heated solution was mixed and dispersed by a mechanical disperser having a circulation path to produce emulsified particles having a uniform dispersed particle size. Subsequently, a solution in which 0.84 g of a polymerization initiator (potassium persulfate: KPS) was dissolved in 200 g of ion-exchanged water was added, and the mixture was heated and stirred at 80 ° C. for 3 hours to prepare latex particles. Subsequently, a solution obtained by further dissolving 7.73 g of a polymerization initiator (KPS) in 240 ml of ion-exchanged water was added, and after 15 minutes, 383.6 g of styrene, 140.0 g of n-butyl acrylate, 36. A mixed solution of 4 g and 14.0 g of n-octyl-3-mercaptopropionic acid ester was dropped over 120 minutes. After completion of dropping, the mixture was heated and stirred for 60 minutes and then cooled to 40 ° C. to obtain latex particles.

  This latex particle is designated as Latex 1.

<< Manufacture of colored particles >>
(Production of colored particles 1)
Sodium n-dodecyl sulfate = 9.2 g is dissolved in 160 ml of ion-exchanged water with stirring. Under stirring, 20 g of Legal 330R (carbon black manufactured by Cabot Corporation) was gradually added, and then dispersed using CLEARMIX. As a result of measuring the particle diameter of the dispersion using an electrophoretic light scattering photometer ELS-800 manufactured by Otsuka Electronics Co., Ltd., the mass average diameter was 112 nm. This dispersion is referred to as “colorant dispersion 1”.

1250 g of the above-mentioned “Latex 1”, 2000 ml of ion-exchanged water, and “Colorant dispersion 1” are placed in a 5-liter four-necked flask equipped with a temperature sensor, a cooling tube, a nitrogen introducing device, and a stirring device and stirred. After adjusting to 30 ° C., a 5 mol / liter aqueous sodium hydroxide solution was added to this solution to adjust the pH to 10.0. Subsequently, an aqueous solution in which 52.6 g of magnesium chloride hexahydrate was dissolved in 72 ml of ion-exchanged water was added at 30 ° C. for 5 minutes with stirring. Thereafter, after standing for 2 minutes, temperature increase is started, and the temperature is raised to 90 ° C. in 5 minutes (temperature increase rate = 12 ° C./min). In that state, the particle size was measured with a Coulter Counter TAII, and when the volume average particle size reached 4.3 μm, an aqueous solution in which 115 g of sodium chloride was dissolved in 700 ml of ion-exchanged water was added to stop the particle growth and continue. Then, the mixture is heated and stirred at a liquid temperature of 85 ° C. ± 2 ° C. for 8 hours to cause salting out / fusion. Then, it cooled to 30 degreeC on the conditions of 6 degreeC / min, hydrochloric acid was added, pH was adjusted to 2.0, and stirring was stopped. The produced colored particles were filtered / washed, and wet cake-like colored particles were collected by filtration. The wet cake-like colored particles (water content: 48% by mass) are subjected to a drying process (primary drying) using a continuous instantaneous air flow dryer “flash jet dryer, model: 5 cm” (manufactured by Seishin Enterprise Co., Ltd.). went. Here, 120 ° C. The inlet temperature of the continuous instantaneous flash dryer, the outlet temperature of 55 ° C., the air flow 2 Nm ³ / min ( "Nm ^3" are the same.. Or less representative of the volume of the room temperature equivalent) was set to. In addition, the water content of the colored particles discharged from the continuous instantaneous air dryer is sequentially measured so that the water content of the colored particles is 5% by mass or less. The supply amount (treatment amount) of the particles was controlled in the range of 5 to 20 kg / hour. The time required for this drying process (primary drying) was 90 minutes, and the water content of the colored particles after the drying process was measured and found to be 1.3% by mass (30 ° C., 80% RH).

  Next, the dried particles (primary dried) with a water content of 1.3% by mass (30 ° C., 80% RH) were dried using a “vibrating fluid dryer” (manufactured by Chuo Kako Co., Ltd.). At 55 ° C., post-drying treatment (secondary drying) was performed until the saturated water content became 0.88% by mass (30 ° C., 80% RH) to obtain “colored particles 1”. Toner 1 obtained by emulsion polymerization association by adding 0.5 part by mass of 0.3 μm strontium titanate and 1.0 part by mass of 15 nm hydrophobic silica to 100 parts by mass of the colored particles 1 using a Henschel mixer. Got.

(Production of colored particles 2, 3 and 4)
In the production of colored particles 1, colored particles 2 to 4 were produced in the same manner except that the production conditions and drying conditions shown in Table 2 were changed.

(Production of colored particles 5 and 6)
In the production of the colored particles 1, the production conditions and the drying conditions described in Table 2 were set, and when the volume average particle size reached 3.8 μm, the particle growth was stopped, and the colored particles 5 and 6 were respectively produced. Manufactured.

(Production of colored particles 7 and 8)
In the production of the colored particles 1, the production conditions and the drying conditions described in Table 2 were set, and when the volume average particle size became 5.5 μm, the particle growth was stopped. Manufactured.

(Production of colored particles 9)
In the production of colored particles 1 and the drying conditions, the particle growth was stopped when the number average particle size reached 7.3 μm, and colored particles 9 were produced.

  The production conditions for the colored particles 1 to 9 are shown in Table 2.

(Manufacture of toner particles)
1% by mass of hydrophobic silica (number average primary particle size = 12 nm, degree of hydrophobization = 68) and hydrophobic titanium oxide (number average primary particle size = 20 nm, hydrophobized) were obtained, respectively. Toner 1 to 9 were obtained by adding 0.5 mass% of degree = 63) and mixing with a Henschel mixer.

  Table 3 shows the particle size distribution characteristics of the obtained toners 1 to 9 and the saturated water content described above.

(Manufacture of developer)
Each of the toners 1 to 9 was mixed with a ferrite carrier having a volume average particle diameter of 60 μm coated with a silicone resin to produce developers 1 to 9 having a toner concentration of 6%.

(Evaluation 1)
The photoconductors 1 to 8, the developers 1 to 9, and the separation claws 1 to 4 having the configuration shown in FIG. 2 are combined as shown in Table 4 and attached to the image forming apparatus shown in FIG. Below, an image formation test of 1 million sheets was performed using a transfer paper having a process speed of 350 mm / sec and a Clark stiffness of 13 cm ³ .

  In addition, the following separation claws 1 to 4 having different water absorption rates were used in combination as shown in Table 4 for the separation claws at this time. The shape of these separation claws is a quadrangular pyramid shape shown in FIG. The separation claw is in contact with the photosensitive member like the separation claw 101 in FIG. 2, and the contact conditions are such that the contact angle a is 9 degrees, the rake angle d is −4 degrees, and c is 40 degrees. The image forming apparatus is a digital electrophotographic system, and the developing unit is a reversal developing system. The separation claw 101 is swung, a 200 mgf spring load is applied, and the contact is released except when the transfer paper P is separated.

Separation Claw 1: Separation Claw Covered with Potassium Tetrafluoroethylene Resin (0.00% by Mass Water Absorption) on SUS Metal Member Separation Claw 2: Polyester Ether Ketone (VICTREX450G: Water Absorption Rate 0.13% by Mass) Separation claw molded with ICI) Separation claw 3: Separation claw molded with polyamideimide resin (TORLON 4000T: manufactured by Mitsubishi Kasei Co., Ltd.) having a water absorption rate of 0.18% by mass Separation claw 4: Water absorption rate of 0.24 Separation claw molded with a mass% polyamideimide resin (TORLON 4275: manufactured by Mitsubishi Kasei Co., Ltd.) Evaluation items and evaluation criteria are shown below.
(Evaluation items and criteria)
Evaluation of nail scratches on the surface of the photoreceptor ○: There is little generation of scratches due to separation nails on the surface of the photoreceptor, and the image (halftone image) is clear (no problem in practical use)
×: Abrasion caused by the separation nail occurs on the surface of the photoconductor, and the image (halftone image) is rough (practically problematic)
Evaluation of photoconductor surface cracks ◎: No cracks on photoconductor surface (good)
○: Although small cracks are observed on the surface of the photoreceptor, no traces of cracks appear in the image (no problem in practical use)
X: A crack is generated in the photoconductor, and a crack image is generated in the image (there is a problem in practice).
Evaluation of transfer paper separation performance ◎; No transfer paper separation failure occurred during 1 million sheet image test (good)
○: Occurrence of separation failure of transfer paper 5 times or less during 1 million image test (no problem in practical use)
×: During the image test of 1 million sheets, the transfer paper separation failure occurred 6 times or more (there is a problem in practical use)

  From the results of Table 4, a combination (combination No. 1) in which the organophotoreceptor has surface properties having the relationship of the general formula (1) and the separation nail has a water absorption of less than 0.2%. Nos. 6, 9, 10, 12 to 19) show no image deterioration due to the occurrence of claw scratches or cracks on the surface of the photoreceptor, and the transfer paper has good separability. On the other hand, when the surface physical properties of the organic photoreceptor deviated from the relationship of the general formula (1) (combination Nos. 7 and 8), the combination No. using the photoconductor 7 having a B / A of less than 1.0 was used. In No. 7, halftone images are deteriorated due to claw scratches on the surface of the photoreceptor, and transfer paper is poorly separated. Combination No. using a photoreceptor 8 having a B / A greater than 1.5 In No. 8, image degradation due to cracks occurs, and transfer paper separation failure also occurs. Further, even if the photoreceptor is within the scope of the present invention, the combination No. using a separation claw made of a member having a water absorption rate of 0.2 or more is used. 11, the halftone image is deteriorated due to a claw on the surface of the photoreceptor, and the transfer paper is also separated.

(Evaluation 2)
Evaluation 2 was performed under the same conditions as in Evaluation 1 except that the transfer paper with a Clark stiffness of 13 cm ³ was changed to a transfer paper with a Clark stiffness of 22 cm ³ under the conditions of Evaluation 1 at a process speed of 350 mm / sec to 250 mm / sec.

  As a result of evaluation 2, an evaluation result almost equivalent to evaluation 1 was obtained.

Production of photoconductors 9 and 10 Photoconductor 9 was produced in the same manner as in production of photoconductor 1 except that the diameter of the cylindrical aluminum substrate was changed from 80 mm to 40 mm, and the diameter of the cylindrical aluminum substrate was changed from 80 mm to 220 mm. A photoconductor 10 was produced in the same manner except that it was changed to. The surface properties such as B / A of the photoconductor 9 and the photoconductor 10 were almost the same as those of the photoconductor 1.

(Evaluation 3)
Evaluation 3 was performed under the same conditions as in Evaluation 1 except that the transfer paper with a Clark stiffness of 13 cm ³ was changed to a transfer paper with a Clark stiffness of 10 cm ³ under the conditions of Evaluation 1 at a process speed of 350 mm / sec to 200 mm / sec.

  The evaluation results of the photoconductor 9 and the photoconductor 10 of the evaluation 3 were almost the same as the evaluation results of the photoconductor 1 of the evaluation 1.

1 is a schematic configuration diagram illustrating an embodiment of an image forming apparatus of the present invention. It is a block diagram of the isolation | separation means which provided the isolation | separation nail | claw used for this invention. It is a shape figure of a separation nail. It is a figure explaining the contact conditions of a separation nail. It is a figure which shows an example of the measurement data of a work function.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Organic photoreceptor 3 Charging means 4 Writing means 5 Developing means 6 Transfer means 7 Electric discharge means 8 Cleaning means 9 Intermediate conveyance part 10 Separation means 11 Fixing means 12 Paper discharge tray 13 Transfer paper storage means 80 Cleaning blade 101 Separation Claw 102 Release plate 103 Claw pressing spring 104 Rotating shaft 105 Support member P Transfer paper

Claims (12)

Transfer means for transferring a toner image formed on the surface of a drum-shaped organic photoconductor at a process speed of 200 mm / sec or more to a transfer paper having a Clark stiffness of 30 cm ³ or less, and separation for separating the transfer paper from the organic photoconductor In the image forming apparatus provided with a separation unit having a nail, the organic photoreceptor has a surface physical property having a relationship represented by the following general formula (1), and the water absorption rate of the separation nail is less than 0.2%: An image forming apparatus comprising:
General formula (1): 1.5 ≧ B / A ≧ 1.0
However,
A represents the ratio of elastic work (We2) and total work (Wt2) measured with an indentation load of 2 mN: We2 / Wt2,
B represents a ratio of elastic work (We20) and total work (Wt20) measured with an indentation load of 20 mN: We20 / Wt20. The image forming apparatus according to claim 1, wherein the organic photoreceptor has a drum shape having an outer diameter of 40 to 240 mm. The image forming apparatus according to claim 1, wherein at least a surface of the separation claw is a resin. The image forming apparatus according to claim 1, wherein at least a part of the surface of the separation claw is a fluororesin. The image forming apparatus according to claim 1, wherein the separating unit includes a unit in which the separating claw swings at a contact portion with the organic photoconductor. The toner used to form a toner image on the organic photoreceptor has a particle size of 0.7 × (Dp50) or less and a number of 10% by number where the particle size of the toner particles is 50% (Dp50). The image forming apparatus according to claim 1, wherein: The toner used to form a toner image on the organic photoreceptor has a ratio (Dv50 / Dp50) of 50% volume particle size (Dv50) to 50% number particle size (Dp50) of the toner particles of 1.0 to 1.0. 1.15: The ratio (Dv75 / Dp75) of 75% cumulative volume particle size (Dv75) from the larger volume particle size to 75% cumulative particle size (Dp75) from the larger number particle size is 1. The image forming apparatus according to claim 1, wherein the number of particles having a particle size of 0 to 1.20 and a particle size of 0.7 × (Dp50) or less is 10 number% or less. The image forming apparatus according to claim 6, wherein the 50% volume particle size (Dv50) is 2 to 9 μm. The image forming apparatus according to claim 6, wherein the toner is a polymerized toner. The image forming apparatus according to claim 9, wherein a saturated water content of the polymerized toner in an environment of 30 ° C. and 80 RH% is 0.1 to 2.5% by mass. The image forming apparatus according to claim 1, wherein the surface layer of the organic photoreceptor is a siloxane-based resin layer having a crosslinked structure. A transfer step of transferring a toner image formed on the surface of a drum-shaped organic photoconductor at a process speed of 200 mm / sec or more onto a transfer paper having a Clark stiffness of 30 cm ³ or less, and a separation for separating the transfer paper from the organic photoconductor In the image forming method of preparing an electrophotographic image including a separation step having a nail, the organophotoreceptor has a surface property having a relationship represented by the following general formula (1), and the water absorption rate of the separation nail is 0. An image forming method comprising a member of less than 2%.
General formula (1): 1.5 ≧ B / A ≧ 1.0
However,
A represents the ratio of elastic work (We2) and total work (Wt2) measured with an indentation load of 2 mN: We2 / Wt2,
B represents a ratio of elastic work (We20) and total work (Wt20) measured with an indentation load of 20 mN: We20 / Wt20.

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