JP2014066767A - Cleaning blade and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning blade configured to prevent abnormal wear/noise as compared with a conventional cleaning blade, while improving cleaning performance, and to provide an image forming apparatus.SOLUTION: A cleaning blade 62 is formed by covering at least an impregnated tip ridge part 62c of a strip elastic blade 622 with a surface layer 623 harder than the elastic blade 622. The cleaning blade 62 comes in contact with a surface of a member to be cleaned, such as a photoreceptor 10 surface-moving on the tip ridge part 62c of the elastic blade 622 to remove powder from the surface of the member to be cleaned. The elastic blade 622 is formed of a plurality of layers including materials different in 100% modulus value. An edge layer 622a in the layers of the elastic blade 622, which forms the tip ridge part 62c, is formed of a material higher in 100% modulus value than other layers, such as a backup layer 622b.

Description

  The present invention relates to a cleaning blade and an image forming apparatus.

2. Description of the Related Art Conventionally, in an electrophotographic image forming apparatus, unnecessary transfer residual toner adhering to a surface after transferring a toner image to a transfer paper or an intermediate transfer body is removed as a cleaning unit. Has been removed by.
As a cleaning member of this cleaning device, one that uses a strip-shaped cleaning blade is well known because it can generally be simplified in configuration and has excellent cleaning performance. This cleaning blade is made of an elastic body such as polyurethane rubber. Then, the base end of the cleaning blade is supported by a support member, and the leading edge portion is pressed against the peripheral surface of the image carrier, and the toner remaining on the image carrier is damped and scraped off and removed.

  Further, in order to meet the recent demand for higher image quality, an image forming apparatus using a toner having a small particle diameter and a nearly spherical shape (hereinafter, polymerized toner) formed by a polymerization method or the like is known. This polymerized toner has characteristics such as higher transfer efficiency than conventional pulverized toner, and can meet the above requirements. However, it is difficult to remove the polymerized toner sufficiently from the surface of the image carrier using a cleaning blade, and there is a problem that cleaning failure occurs. This is because the polymerized toner having a small particle size and excellent sphericity passes through a slight gap formed between the blade and the image carrier.

In order to suppress such slip-through, it is necessary to increase the cleaning pressure by increasing the contact pressure between the image carrier and the cleaning blade. However, as described in Patent Document 1, it is known that the following problems occur.
When the contact pressure of the cleaning blade is increased, the frictional force between the image carrier 123 and the cleaning blade 62 increases as shown in FIG. 18A, and the cleaning blade 62 is pulled in the moving direction of the image carrier 123. The leading edge portion 62c of the cleaning blade 62 is turned up. When the turned cleaning blade 62 is restored to its original state against the turn, abnormal noise may occur. Furthermore, if the cleaning is continued with the leading edge portion 62c of the cleaning blade 62 turned up, as shown in FIG. 18B, the cleaning blade 62 is separated from the leading edge portion 62c of the blade leading surface 62a by several [μm]. Local wear will occur at the spot. If the cleaning is further continued in such a state, the local wear increases, and the leading edge portion 62c is eventually lost as shown in FIG. 18C. If the leading edge portion 62c is missing, the toner cannot be properly cleaned, resulting in poor cleaning.

  In order to solve the above problems, in Patent Document 1, at least the tip ridge line portion is impregnated with at least one selected from an isocyanate compound, a fluorine compound, and a silicone compound, and the elastic blade A novel cleaning blade is proposed that is composed of a surface layer made of an ultraviolet curable resin that is harder than the elastic blade that covers the tip ridge.

  The novel cleaning blade proposed in Patent Document 1 is provided with a harder surface layer than the elastic blade to increase the hardness of the tip ridge line portion, thereby deforming the tip ridge line portion in the surface movement direction of the image carrier. Can be suppressed. Further, by impregnating the tip ridge portion of the elastic blade, the friction coefficient of the tip ridge portion of the elastic blade can be lowered. As a result, even when the surface layer is worn over time and the tip ridge line portion of the elastic blade is exposed, the impregnated portion of the elastic blade comes into contact with the surface of the image carrier, so that the image carrier of the elastic blade The behavior of the abutting portion can be moderately suppressed. As a result, the occurrence of abnormal wear and abnormal noise can be suppressed over time, and poor cleaning over time can be suppressed.

  However, even if a cleaning blade composed of an elastic blade impregnated in the tip ridge line and a surface layer made of an ultraviolet curable resin harder than the elastic blade covering the tip ridge line of the elastic blade is used, abnormal wear occurs. The generation of noise and noise cannot be sufficiently suppressed, and further improvement of the cleaning blade is required.

  The present invention has been made in view of the above problems, and its purpose is to suppress the occurrence of abnormal wear and abnormal noise compared to the cleaning blade described in Patent Document 1, and to obtain good cleaning properties. A cleaning blade and an image forming apparatus that can be used.

  In order to achieve the above object, the invention of claim 1 is characterized in that at least the vicinity of the tip ridge line portion of the strip-shaped elastic blade impregnated in the tip ridge line portion is covered with a surface layer harder than the elastic blade, and the tip of the elastic blade In the cleaning blade that contacts the surface of the member to be cleaned that moves the surface of the ridge line and removes the powder from the surface of the member to be cleaned, the elastic blade is made of a plurality of layers made of materials having mutually different 100% modulus values. The edge layer forming the tip ridge line portion of the plurality of layers of the elastic blade is formed of a material having a higher 100% modulus value than other layers.

The inventors of the present invention conducted the following intensive studies on further improvement of wear resistance and cleaning performance of the cleaning blade. That is, as described with reference to FIG. 18, the abnormal wear and abnormal noise are generated by elastic deformation of the tip ridge line portion in the surface movement direction of the object to be cleaned. Therefore, the present inventors can suppress elastic deformation of the tip ridge line portion in the moving direction of the surface of the object to be cleaned by changing the elastic blade to a material that is less elastically deformed than before, and abnormal wear occurs. I thought it was possible to suppress the occurrence of noise. Based on this idea, the present inventors tried to use an elastic blade having a 100% modulus value higher than that of the conventional one. Here, the 100% modulus is a tensile stress when 100% elongation is given to an elastic rubber test piece, and is generally used as an index value indicating the difficulty (hardness) of elastic deformation of rubber. Is. In this way, by using an elastic blade having a 100% modulus value higher than that of the conventional elastic blade, it is possible to make the tip ridge line portion harder and less elastically deformed than the cleaning blade described in Patent Document 1. It was thought that abnormal wear and abnormal noise could be sufficiently suppressed. However, in this case, the cleaning blade was too rigid, and when the cleaning was brought into contact with the object to be cleaned, the cleaning blade was not sufficiently bent. As a result, the cleaning blade could not sufficiently follow the undulation of the surface of the object to be cleaned, and the cleaning performance deteriorated.
Therefore, in the present invention, the elastic blade is constituted by a plurality of layers made of materials having mutually different 100% modulus values, and among the plurality of layers of the elastic blade, the edge layer that forms the tip ridge line portion is used as another layer. Compared with a material having a higher modulus value than 100%. As a result, the cleaning blade can have appropriate elasticity, and the tip ridge line portion can be further stiffened. As a result, the cleaning blade can be made to follow well the undulation of the surface of the object to be cleaned, and good cleaning properties can be ensured. Further, it is possible to suppress the tip ridge line portion from being elastically deformed in the surface moving direction of the object to be cleaned as compared with the cleaning blade described in Patent Document 1, and further stabilize the behavior of the contact portion of the cleaning blade with the object to be cleaned. Can be Thereby, generation | occurrence | production of abnormal wear and abnormal noise can be suppressed compared with the cleaning blade of patent document 1. FIG.

  According to the present invention, the occurrence of abnormal wear or abnormal noise can be suppressed as compared with the cleaning blade described in Patent Document 1, and good cleaning properties can be obtained.

1 is a schematic configuration diagram illustrating a printer according to an embodiment. FIG. 2 is a schematic configuration diagram illustrating a process cartridge included in the printer. FIG. 2 is a schematic perspective view of a charging roller provided in the process cartridge. The figure which represented the shape of the toner typically in order to demonstrate shape factor SF-1. The figure which represented the shape of the toner typically in order to demonstrate shape factor SF-2. FIG. 3 is a diagram schematically illustrating a toner shape. Explanatory drawing for demonstrating the measuring method of the circularity of a toner. The perspective view of the cleaning blade of this embodiment. (A) is explanatory drawing of the state in which the cleaning blade is in contact with the surface of the photoreceptor. FIG. 6B is an enlarged explanatory view of the vicinity of the tip ridge line portion 62 c of the cleaning blade 62. The schematic block diagram which shows a holder and an elastic blade. The figure which shows an example of the cleaning blade only of an elastic blade. The figure which shows an example of the cleaning blade which provided the impregnation part and the surface layer in the single layer elastic blade. The figure which shows the cleaning blade of this embodiment. (A) is a figure which shows the cross section of the photoreceptor which provided the photosensitive layer on the electroconductive support body. (B) is a figure which shows the example which further provided the surface layer in the structure of (a). (C) is a figure which shows the example which made the photosensitive layer 2 layer structure in the structure of (b). (D) is a figure which shows the example which provided the undercoat layer in the structure of (c). The schematic block diagram which shows the printer which provided the soundproof member and the ozone filter. FIG. 10 is a schematic configuration diagram illustrating a modified example of a printer. FIG. 7 is a schematic configuration diagram illustrating a K color process cartridge in the printer according to the modification. (A) is a diagram showing a state in which the leading edge portion of the cleaning blade is turned up, (b) is a diagram for explaining local wear on the leading end surface of the cleaning blade, and (c) is a diagram showing the leading edge portion of the cleaning blade. The figure which shows the state missing. (A) is a figure which shows the input image of the verification experiment 1. FIG. (B) is a figure which shows the input image of the verification experiment 2. FIG. (C) is a figure which shows the input image of the verification experiment 3. FIG.

  Hereinafter, an embodiment in which the present invention is applied to a printer as an image forming apparatus will be described. FIG. 1 is a schematic configuration diagram illustrating a printer 100 which is an image forming apparatus according to the present embodiment. The printer 100 forms a full-color image, and mainly includes an image forming unit 120, an intermediate transfer device 160, and a paper feeding unit 130. In the following description, the subscripts Y, C, M, and K indicate members for yellow, cyan, magenta, and black, respectively.

  The image forming unit 120 is provided with a yellow toner process cartridge 121Y, a cyan toner process cartridge 121C, a magenta toner process cartridge 121M, and a black toner process cartridge 121K in order from the left side in the drawing. These process cartridges 121 (Y, C, M, K) are arranged in a substantially horizontal direction.

The intermediate transfer device 160 includes an endless intermediate transfer belt 162 that is an intermediate transfer member stretched around a plurality of support rollers, a primary transfer roller 161 (Y, C, M, K), and a secondary transfer roller 165. And is composed mainly of. The intermediate transfer belt 162 is a drum-shaped photosensitive member 10 (Y, C, M) as an image carrier that moves on the surface of each process cartridge 121 (Y, C, M, K). , K) along the surface movement direction. The intermediate transfer belt 162 moves on the surface in synchronization with the surface movement of the photoreceptor 10 (Y, C, M, K). In addition, each primary transfer roller 161 (Y, C, M, K) is disposed on the inner peripheral surface side of the intermediate transfer belt 162, and intermediate between these primary transfer rollers 161 (Y, C, M, K). The outer peripheral surface (surface) located on the lower side of the transfer belt 162 is in weak pressure contact with the outer peripheral surface (surface) of each photoconductor 10 (Y, C, M, K).

  The configuration and operation of forming a toner image on each photoconductor 10 (Y, C, M, K) and transferring the toner image to the intermediate transfer belt 162 is the same as each process cartridge 121 (Y, C, M, K). Is substantially the same. However, the primary transfer roller 161 (Y, C, M) corresponding to the three color process cartridges 121 (Y, C, M) is provided with a swinging mechanism (not shown) that swings them up and down. . The swing mechanism operates so that the intermediate transfer belt 162 does not contact the photoconductor 10 (Y, C, M) when a color image is not formed.

The intermediate transfer device 160 that is an intermediate transfer unit is configured to be detachable from the main body of the printer 100. Specifically, the front cover (not shown) on the front side in FIG. 1 covering the image forming unit 120 of the printer 100 is opened, and the secondary transfer device 160 is moved from the back side to the front side in FIG. By sliding, the secondary transfer device 160 can be detached from the main body of the printer 100. When the secondary transfer device 160 is attached to the main body of the printer 100, an operation opposite to the removal operation may be performed.
In the intermediate transfer belt 162, on the downstream side of the secondary transfer roller 165 in the surface movement direction and on the upstream side of the process cartridge 121Y, deposits such as residual toner after the secondary transfer adhered on the intermediate transfer belt 162. An intermediate transfer belt cleaning device 167 is provided for removing the toner. The intermediate transfer belt cleaning device 167 is configured to be detachable from the printer 100 main body as the intermediate transfer device 160 in a state of being supported integrally with the intermediate transfer belt 162.

Above the intermediate transfer device 160, toner cartridges 159 (Y, C, M, K) corresponding to the respective process cartridges 121 (Y, C, M, K) are arranged in a substantially horizontal direction.
Further, below the process cartridge 121 (Y, C, M, K), an electrostatic latent image is formed by irradiating the surface of the charged photoreceptor 10 (Y, C, M, K) with laser light. An exposure device 140 is arranged.
A paper feeding unit 130 is disposed below the exposure device 140. The paper feed unit 130 is provided with a paper feed cassette 131 and a paper feed roller 132 for accommodating transfer paper as a recording material, and is provided between the intermediate transfer belt 162 and the secondary transfer roller 165 via a registration roller pair 133. The transfer paper is fed to the secondary transfer nip portion at a predetermined timing.
A fixing device 90 is disposed downstream of the secondary transfer nip portion in the transfer paper conveyance direction, and a discharge roller and a discharged transfer paper are placed downstream of the fixing device 90 in the transfer paper conveyance direction. A paper discharge storage unit is provided for storage.

FIG. 2 is a schematic configuration diagram illustrating a process cartridge 121 provided in the printer 100.
Here, since the configuration of each process cartridge 121 is substantially the same, in the following description, the subscripts Y, C, M, and K for color coding are omitted, and the configuration and operation of the process cartridge 121 will be described.
The process cartridge 121 includes the photoconductor 10 and a cleaning device 30, a charging device 40, and a developing device 50 arranged around the photoconductor 10.

  The charging device 40 is mainly composed of a charging roller 41 disposed so as to contact the photoreceptor 10 and a charging roller cleaner 42 rotating in contact with the charging roller 41. As shown in FIG. 3, the charging roller 41 is provided with a conductive rubber layer 41b on a cored bar 41a, and the surface of the rubber layer is provided with irregularities 41c extending along the circumferential direction. The unevenness 41c can be formed by bringing abrasive paper or the like into contact with the charging roller 41 being rotated. Due to the unevenness 41c, the contact area with respect to the photoreceptor 10 is small, and the contact portion and the gap portion are appropriately distributed. Therefore, the chance of discharge is increased and the charging is stabilized. In particular, when the linear velocity is high, the effect of charging stability is great. In addition, since the contact area is small, the charging roller 41 is less likely to be contaminated by the charging roller 41, and conversely, the charging roller 41 is not easily contaminated by toner on the photosensitive member 10. The bias applied to the charging roller 41 is a direct current. By using a direct current, the load on the photoconductor 10 is reduced, the amount of wear of the photoconductor 10 is reduced, and the life can be extended.

  The unevenness 41c of the charging roller 41 is preferably formed so that the ten-point average surface roughness Rz is 20 μm or less. As a result, the acceleration of photoconductor wear can be minimized and the life can be extended. Further, by setting the 10-point average surface roughness Rz of the charging roller 41 to 20 μm or less, the charging roller 41 is less likely to be discharged unevenly, and the surface of the photoreceptor can be charged without unevenness. Since the surface of the photoreceptor can be charged without unevenness, it is possible to output a high-quality image without image density unevenness. In general, the surface potential of the photoreceptor is likely to be unstable (the surface potential fluctuation range is likely to increase) in a low-temperature and low-humidity environment, but the ten-point average surface roughness Rz is 20 μm or less on the surface of the charging roller 41. By forming 41c, the surface potential of the photoreceptor 10 can be stabilized even in a low temperature and low humidity environment.

  Further, it is preferable that the surface layer portion of the charging roller 41 is surface-treated with a surface treatment liquid containing fluorine, whereby contamination of the photoreceptor 10 can be prevented in any environment.

  The developing device 50 has a developing roller 51 as a developer carrier. A developing bias is applied to the developing roller 51 from a power source (not shown). In the casing of the developing device 50, a supply screw 52 and a stirring screw 53 are provided that stir the developer contained in the casing while conveying the developer in opposite directions. A doctor 54 for regulating the developer carried on the developing roller 51 is also provided. The toner in the developer stirred and conveyed by the two screws of the supply screw 52 and the stirring screw 53 is charged to a predetermined polarity. Then, the developer is pumped onto the surface of the developing roller 51, and the pumped developer is regulated by the doctor 54, and the toner adheres to the latent image on the photoconductor 10 in the development area facing the photoconductor 10. .

  The cleaning device 30 includes a cleaning blade 62, a recovery screw 43, and the like. The cleaning blade 62 is in contact with the photoconductor 10 in the counter direction with respect to the surface movement direction of the photoconductor 10. The toner remaining on the photoreceptor 10 after the toner image is transferred to the intermediate transfer belt 162 is cleaned by the cleaning blade 62. The toner removed from the cleaning blade 62 is transported by a recovery screw 43 to a waste toner container (not shown). Details of the cleaning blade 62 will be described later.

  The four process cartridges 121 having the above-described configuration can be detached and replaced independently by a service person or a user. Further, with respect to the process cartridge 121 removed from the printer 100, the photoconductor 10, the charging device 40, the developing device 50, and the cleaning device 30 are each configured to be replaceable with a new device. The process cartridge 121 may include a waste toner tank that collects the transfer residual toner collected by the cleaning device 30. In this case, if the configuration is such that the waste toner tank can be detached and replaced independently in the process cartridge 121, the convenience is improved.

Next, the operation of the printer 100 will be described.
In the printer 100, when a print command is received from an external device such as an operation panel (not shown) or a personal computer, first, the photosensitive member 10 is rotated in the direction of arrow A in FIG. 2 and the photosensitive member 41 is charged by the charging roller 41 of the charging device 40. 10 surfaces are uniformly charged to a predetermined polarity. The exposure device 140 irradiates, for example, laser beam light, which is light-modulated in accordance with the input color image data, on the surface of each photoconductor 10 with respect to the surface of each photoconductor 10. The electrostatic latent image is formed. Each electrostatic latent image is supplied with a developer of each color from the developing roller 51 of the developing device 50 of each color, and the electrostatic latent image of each color is developed with the developer of each color to form a toner image corresponding to each color. To visualize it. Next, by applying a transfer voltage having a polarity opposite to that of the toner image to the primary transfer roller 161, a primary transfer electric field is formed between the photoreceptor 10 and the primary transfer roller 161 with the intermediate transfer belt 162 interposed therebetween, and the primary transfer roller In 161, the intermediate transfer belt 162 is slightly pressed to form a primary transfer nip. By these actions, the toner image on each photoconductor 10 is efficiently primary-transferred onto the intermediate transfer belt 162. On the intermediate transfer belt 162, the toner images of the respective colors formed on the respective photoconductors 10 are transferred so as to overlap each other, thereby forming a laminated toner image.

  The laminated toner image that has been primarily transferred onto the intermediate transfer belt 162 is fed at a predetermined timing through the transfer paper accommodated in the paper feed cassette 131 via the paper feed roller 132 and the registration roller pair 133. Then, by applying a transfer voltage having a polarity opposite to that of the toner image to the secondary transfer roller 165, a secondary transfer electric field is formed between the intermediate transfer belt 162 and the secondary transfer roller 165 with the transfer paper interposed therebetween. The laminated toner image is transferred onto the paper. The transfer paper onto which the laminated toner image has been transferred is sent to the fixing device 90 and fixed by heat and pressure. The transfer paper on which the toner image is fixed is discharged and placed in the paper discharge storage portion by the paper discharge roller. On the other hand, the transfer residual toner remaining on each photoconductor 10 after the primary transfer is scraped and removed by the blade member of each cleaning device 30.

Next, toner suitable for the printer 100 to which the present invention is applied will be described.
The toner preferably used in this printer preferably has a volume average particle diameter of 3 to 6 [μm] in order to reproduce minute dots of 600 dpi or more. A toner having a ratio (Dv / Dn) of volume average particle diameter (Dv) to number average particle diameter (Dn) in the range of 1.00 to 1.40 is preferable. The closer (Dv / Dn) is to 1.00, the sharper the particle size distribution. With such a toner having a small particle size and a narrow particle size distribution, the toner charge amount distribution is uniform, a high-quality image with little background fogging can be obtained, and the electrostatic transfer method has a high transfer rate. can do.

The toner shape factor SF-1 is preferably in the range of 100 to 180, and the shape factor SF-2 is preferably in the range of 100 to 180. FIG. 4 is a diagram schematically showing the shape of the toner in order to explain the shape factor SF-1. The shape factor SF-1 indicates the ratio of the roundness of the toner shape and is represented by the following formula (1). This is a value obtained by dividing the square of the maximum length MXLNG of the shape formed by projecting the toner on a two-dimensional plane by the figure area AREA and multiplying by 100π / 4.
SF-1 = {(MXLNG) ² / AREA} × (100π) / 4 Formula (1)
When the value of SF-1 is 100, the shape of the toner becomes a true sphere, and becomes larger as the value of SF-1 increases.

FIG. 5 is a diagram schematically showing the shape of the toner in order to explain the shape factor SF-2. The shape factor SF-2 indicates the ratio of unevenness in the shape of the toner, and is represented by the following formula (2). A value obtained by dividing the square of the perimeter PERI of the figure formed by projecting the toner on the two-dimensional plane by the figure area AREA and multiplying by 100 / (4π).
SF-2 = {(PERI) ² / AREA} × 100 / (4π) (2)
When the value of SF-2 is 100, there is no unevenness on the toner surface, and as the value of SF-2 increases, the unevenness of the toner surface becomes more prominent.

  Specifically, the shape factor is measured by taking a photograph of the toner with a scanning electron microscope (S-800: manufactured by Hitachi, Ltd.), introducing it into an image analyzer (LUSEX 3: manufactured by Nireco) and analyzing it. Calculated. When the shape of the toner is close to a spherical shape, the contact state between the toner and the toner or the toner and the photoconductor becomes a point contact, so that the adsorbing force between the toners becomes weak and the fluidity increases, and the toner and the photoconductor The attraction force becomes weaker and the transfer rate becomes higher. If either of the shape factors SF-1 and SF-2 exceeds 180, the transfer rate is lowered, which is not preferable.

  In addition, a toner suitably used for a color printer is a toner material liquid in which at least a polyester prepolymer having a functional group containing a nitrogen atom, polyester, a colorant, and a release agent are dispersed in an organic solvent. Is a toner obtained by crosslinking and / or elongation reaction in an aqueous solvent. Hereinafter, the constituent material and the manufacturing method of the toner will be described.

(polyester)
The polyester is obtained by a polycondensation reaction between a polyhydric alcohol compound and a polycarboxylic acid compound.
Examples of the polyhydric alcohol compound (PO) include dihydric alcohol (DIO) and trihydric or higher polyhydric alcohol (TO). (DIO) alone or a mixture of (DIO) and a small amount of (TO) preferable. Examples of the dihydric alcohol (DIO) include alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (diethylene glycol) , Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol) F, bisphenol S, etc.); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol; Alkylene oxide bisphenol (ethylene oxide, propylene oxide, butylene oxide, etc.), etc. adducts. Among them, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use. The trihydric or higher polyhydric alcohol (TO) includes 3 to 8 or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (Trisphenol PA, phenol novolak, cresol novolak, etc.); and alkylene oxide adducts of the above trivalent or higher polyphenols.

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

  The ratio of the polyhydric alcohol (PO) to the polycarboxylic acid (PC) is usually 2/1 to 1/1, preferably as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. Is 1.5 / 1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1. The polycondensation reaction of polyhydric alcohol (PO) and polycarboxylic acid (PC) is performed at 150 to 280 ° C. in the presence of a known esterification catalyst such as tetrabutoxytitanate or dibutyltin oxide, while reducing the pressure as necessary. The produced water is distilled off to obtain a polyester having a hydroxyl group. The hydroxyl value of the polyester is preferably 5 or more, and the acid value of the polyester is usually 1 to 30, preferably 5 to 20. By giving an acid value, it tends to be negatively charged, and furthermore, when fixing to a recording paper, the affinity between the recording paper and the toner is good and the low-temperature fixability is improved. However, when the acid value exceeds 30, there is a tendency to deteriorate with respect to the stability of charging, particularly environmental fluctuation. The weight average molecular weight is 10,000 to 400,000, preferably 20,000 to 200,000. A weight average molecular weight of less than 10,000 is not preferable because offset resistance deteriorates. On the other hand, if it exceeds 400,000, the low-temperature fixability is deteriorated.

  In addition to the unmodified polyester obtained by the above polycondensation reaction, the polyester preferably contains a urea-modified polyester. The urea-modified polyester is obtained by reacting a terminal carboxyl group or hydroxyl group of the polyester obtained by the above polycondensation reaction with a polyvalent isocyanate compound (PIC) to obtain a polyester prepolymer (A) having an isocyanate group. It is obtained by cross-linking and / or extending the molecular chain by the reaction of the amine with amines. Examples of the polyvalent isocyanate compound (PIC) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-isocyanatomethyl caproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.) Aromatic diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanates; phenol derivatives, oximes, caprolactam And a combination of two or more of these. The ratio of the polyvalent isocyanate compound (PIC) is usually 5/1 to 1/1, preferably as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. 4/1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5/1, the low-temperature fixability deteriorates. When the molar ratio of [NCO] is less than 1/1, when a urea-modified polyester is used, the urea content in the ester becomes low and hot offset resistance deteriorates. The content of the polyvalent isocyanate compound (PIC) component in the polyester prepolymer (A) having an isocyanate group is usually 0.5 to 40 wt%, preferably 1 to 30 wt%, more preferably 2 to 20 wt%. . If it is less than 0.5 wt%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40 wt%, the low-temperature fixability deteriorates. The number of isocyanate groups contained per molecule in the polyester prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2 on average. Five. If it is less than 1 per molecule, the molecular weight of the urea-modified polyester will be low, and the hot offset resistance will deteriorate.

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

  Examples of the divalent amine compound (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′-dimethyldicyclohexyl). Methane, diamine cyclohexane, isophorone diamine, etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.) and the like. Examples of the trivalent or higher polyvalent amine compound (B2) include diethylenetriamine and triethylenetetramine. Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid. Examples of B1 to B5 blocked amino groups (B6) include ketimine compounds and oxazolidine compounds obtained from the amines of B1 to B5 and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Among these amines (B), preferred are B1 and a mixture of B1 and a small amount of B2.

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

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

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

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

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

  The weight average molecular weight of the urea-modified polyester is usually 10,000 or more, preferably 20,000 to 10,000,000, and more preferably 30,000 to 1,000,000. If it is less than 10,000, the hot offset resistance deteriorates. The number average molecular weight of the urea-modified polyester or the like is not particularly limited when the above-mentioned unmodified polyester is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. When the urea-modified polyester is used alone, its number average molecular weight is usually 2000-15000, preferably 2000-10000, more preferably 2000-8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color image forming apparatus are deteriorated.

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

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

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

  The glass transition point (Tg) of the binder resin containing unmodified polyester and urea-modified polyester is usually 45 to 65 ° C, preferably 45 to 60 ° C. If the temperature is lower than 45 ° C., the heat resistance of the toner is deteriorated.

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

(Coloring agent)
As the colorant, all known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher , Lead yellow, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR1, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Vulcan fast yellow (5G, R) , Tartrazine rake, quinoline yellow rake, anthrazan yellow BGL, isoindolinone yellow, bengara, red lead, lead vermilion, cadmium red, cadmium mercurial red, antimon vermilion, permanent red 4R, para red, phissa red Parachlor ortho nitro Nirin Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine B, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, thioindigo maroon, oil red, quinacridone red, pyrazolone red, Riazo Red, Chrome Vermillion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), indigo, ultramarine blue, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Phthalo Cyanine green, anthraquinone green, titanium oxide, zinc white, litbon and mixtures thereof can be used. The content of the colorant is usually 1 to 15% by weight, preferably 3 to 10% by weight, based on the toner.

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

(Charge control agent)
Known charge control agents can be used, such as nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified 4 Secondary ammonium salts or compounds, tungsten simple substances or compounds, fluorine activators, salicylic acid metal salts, and metal salts of salicylic acid derivatives. Specifically, Bontron 03 of a nigrosine dye, Bontron P-51 of a quaternary ammonium salt, Bontron S-34 of a metal-containing azo dye, E-82 of an oxynaphthoic acid metal complex, E-84 of a salicylic acid metal complex , Phenolic condensate E-89 (above, Orient Chemical Industries, Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, Hodogaya Chemical Co., Ltd.), quaternary ammonium salt copy Charge PSYVP2038, copy blue PR of triphenylmethane derivative, copy charge NEG VP2036 of quaternary ammonium salt, copy charge NX VP434 (manufactured by Hoechst), LR1-901, LR-147 which is a boron complex (manufactured by Nippon Carlit) ), Copper phthalocyanine, perylene, quinacridone, azo face , Sulfonate group, carboxyl group, and polymer compounds having a functional group such as quaternary ammonium salts. Of these, substances that control the negative polarity of the toner are particularly preferably used.

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

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

  The charge control agent and the release agent can be melt-kneaded together with the masterbatch and the binder resin, or may be added when dissolved and dispersed in an organic solvent.

(External additive)
Inorganic fine particles are preferably used as an external additive for assisting the fluidity, developability and chargeability of the toner particles. The primary particle diameter of the inorganic fine particles is preferably ⁵ × ¹⁰ -3~2 [μm], it is particularly preferably ⁵ × ¹⁰ -3~0.5 [μm]. Moreover, it is preferable that the specific surface area by BET method is 20-500 [m2 / g]. The use ratio of the inorganic fine particles is preferably 0.01 to 5 wt% of the toner, and particularly preferably 0.01 to 2.0 wt%. Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, quartz sand, clay, mica, wollastonite, diatomaceous earth. Examples include soil, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. Among these, as the fluidity imparting agent, it is preferable to use hydrophobic silica fine particles and hydrophobic titanium oxide fine particles in combination. In particular, when stirring and mixing are performed using particles having an average particle diameter of 5 × 10 ⁻⁴ μm or less, the electrostatic force and van der Waals force with the toner are remarkably improved. Even when stirring and mixing inside the developing device is performed to obtain a good image quality that does not cause the release of the fluidity imparting agent from the toner and does not generate firefly, etc., and further reduces the residual toner. It is done. Titanium oxide fine particles are excellent in environmental stability and image density stability, but have a tendency to deteriorate the charge rise characteristics. Therefore, if the amount of titanium oxide fine particles added is larger than the amount of silica fine particles added, this side effect is affected. It can be considered large. However, when the added amount of the hydrophobic silica fine particles and the hydrophobic titanium oxide fine particles is in the range of 0.3 to 1.5 wt%, the charge rising characteristics are not greatly impaired, and the desired charge rising characteristics can be obtained, that is, repeated copying. Stable image quality can be obtained even if

  Next, a toner manufacturing method will be described. Here, although a preferable manufacturing method is shown, it is not limited to this.

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

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

  The amount of the aqueous medium used relative to 100 parts by weight of the toner material liquid is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight. If the amount is less than 50 parts by weight, the dispersion state of the toner material liquid is poor, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 20000 parts by weight, it is not economical.

Further, in order to improve the dispersion in the aqueous medium, a dispersant such as a surfactant and resin fine particles is appropriately added.
As surfactants, anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt types such as imidazoline, Quaternary ammonium salt type cationic surfactants such as alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, pyridinium salts, alkylisoquinolinium salts, benzethonium chloride, fatty acid amide derivatives, polyhydric alcohols Nonionic surfactants such as derivatives, for example, amphoteric surfactants such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl-N, N-dimethylammonium betaine And the like.

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

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

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

  The resin fine particles are added to stabilize the toner base particles formed in the aqueous medium. For this reason, it is preferable to add so that the coverage existing on the surface of the toner base particles is in the range of 10 to 90%. For example, polymethyl methacrylate fine particles 1 [μm] and 3 [μm], polystyrene fine particles 0.5 [μm] and 2 [μm], poly (styrene-acrylonitrile) fine particles 1 [μm], trade name is PB- 200H (manufactured by Kao Corporation), SGP (manufactured by Sokensha), technopolymer SB (manufactured by Sekisui Chemical Co., Ltd.), SGP-3G (manufactured by Sokensha), micropearl (manufactured by Sekisui Fine Chemical Co., Ltd.) and the like. In addition, inorganic compound dispersants such as tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, and hydroxyapatite can also be used.

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

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

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

(4) After completion of the reaction, the organic solvent is removed from the emulsified dispersion (reactant), washed and dried to obtain toner base particles.
In order to remove the organic solvent, the temperature of the entire system is gradually raised in a laminar stirring state, and after giving strong stirring in a certain temperature range, the solvent base is removed to produce spindle-shaped toner base particles. . Further, when an acid such as calcium phosphate salt or an alkali-soluble material is used as the dispersion stabilizer, the calcium phosphate salt is dissolved from the toner base particles by a method such as dissolving the calcium phosphate salt with an acid such as hydrochloric acid and washing with water. Remove. It can also be removed by operations such as enzymatic degradation.

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

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

  The toner has a substantially spherical shape and can be represented by the following shape rule. 6A, 6B, and 6C are diagrams schematically illustrating the shape of the toner. 6A, 6B, and 6C, when a substantially spherical toner is defined by a major axis r1, a minor axis r2, and a thickness r3 (where r1 ≧ r2 ≧ r3), the toner is defined. The ratio of the major axis to the minor axis (r2 / r1) (see FIG. 6B) is 0.5 to 1.0, and the ratio of the thickness to the minor axis (r3 / r2) (FIG. 6C )) Is preferably in the range of 0.7 to 1.0. When the ratio of the major axis to the minor axis (r2 / r1) is less than 0.5, the dot reproducibility and transfer efficiency are inferior because of being away from the true spherical shape, and high-quality image quality cannot be obtained. On the other hand, if the ratio of thickness to minor axis (r3 / r2) is less than 0.7, the shape is close to a flat shape, and a high transfer rate like a spherical toner cannot be obtained. In particular, when the ratio of the thickness to the minor axis (r3 / r2) is 1.0, the rotating body has a major axis as a rotation axis, and the fluidity of the toner can be improved.

  Note that r1, r2, and r3 were measured with a scanning electron microscope (SEM) while changing the angle of field of view and taking pictures.

  As the toner used in the printer 100, it is preferable to use a polymerized toner produced by a suspension polymerization method, an emulsion polymerization method, or a dispersion polymerization method, which can easily increase the circularity and reduce the particle size, in order to improve the image quality. In particular, it is preferable to use a polymerized toner having a circularity of 0.97 or more and a volume average particle size of 5.5 [μm] or less. By using a material having an average circularity of 0.97 or more and a volume average particle size of 5.5 [μm], a higher resolution image can be formed.

  The “circularity” here is an average circularity measured by a flow type particle image analyzer FPIA-2000 (trade name, manufactured by Toa Medical Electronics Co., Ltd.). Specifically, a surfactant, preferably an alkylbenzene sulfonate, is added in an amount of 0.1 to 0.5 [ml] as a dispersant in 100 to 150 [ml] of water from which impure solids have been removed in advance. Further, about 0.1 to 0.5 [g] of a measurement sample (toner) is added. Thereafter, the suspension in which the toner is dispersed is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes so that the concentration of the dispersion becomes 3000 to 1 [10,000 / μl]. To measure the shape and distribution of the toner. Based on the measurement result, the outer peripheral length of the actual toner projection shape shown in FIG. 7A is C1, and the projection area is S. The outer circumference of the perfect circle shown in FIG. C2 / C1 was determined when the length was C2, and the average value was defined as the circularity.

  The volume average particle diameter can be determined by a Coulter counter method. Specifically, the toner number distribution and volume distribution data measured by the Coulter Multisizer 2e type (manufactured by Coulter) are sent to a personal computer via an interface (manufactured by Nikkaki Co., Ltd.) for analysis. More specifically, a 1% NaCl aqueous solution using first grade sodium chloride is prepared as an electrolytic solution. Then, 0.1 to 5 [ml] of a surfactant, preferably alkylbenzene sulfonate, is added as a dispersant to 100 to 150 [ml] of the electrolytic aqueous solution. Further, 2 to 20 [mg] of toner as a test sample is added thereto, and dispersion treatment is performed for about 1 to 3 [minutes] with an ultrasonic disperser. Then, 100 to 200 [ml] of the electrolytic aqueous solution is put into another beaker, and the solution after the dispersion treatment is added to the beaker so as to have a predetermined concentration, and then applied to the Coulter Multisizer 2e type. The aperture is 100 [μm], and the particle size of 50,000 toner particles is measured. As a channel, it is less than 2.00-2.52 [micrometer]; 2.52-less than 3.17 [micrometer]; 3.17-less than 4.00 [micrometer]; 4.00-5.04 [micrometer] Less than 5.04 to 6.35 [μm]; 6.35 to less than 8.00 [μm]; 8.00 to less than 10.08 [μm]; 10.08 to less than 12.70 [μm]; 12.70 to less than 16.00 [μm]; 16.00 to less than 20.20 [μm]; 20.20 to less than 25.40 [μm]; 25.40 to less than 32.00 [μm]; Using 13 channels of 00 to less than 40.30 [μm], toner particles with a particle size of 2.00 [μm] or more and 32.0 [μm] or less are targeted. Then, the volume average particle diameter is calculated based on the relational expression “volume average particle diameter = ΣXfV / ΣfV”. However, “X” is the representative diameter in each channel, “V” is the equivalent volume in the representative diameter of each channel, and “f” is the number of particles in each channel.

  In such a polymerized toner, even if an attempt is made to remove the pulverized toner from the surface of the photoconductor 10 with the cleaning blade 62 in the same manner as when the conventional pulverized toner is removed from the surface of the photoconductor 10, the polymerized toner cannot be sufficiently removed from the surface of the photoconductor. Defects occur. Therefore, when the contact pressure of the cleaning blade 62 to the photosensitive member 10 is increased to improve the cleaning performance, there is a problem that the cleaning blade 62 wears out early. Further, the frictional force between the cleaning blade 62 and the photosensitive member 10 is increased, and the leading edge portion 62c of the cleaning blade 62 in contact with the photosensitive member 10 is pulled in the moving direction of the photosensitive member 10, so that the leading edge portion 62c is I will turn over. When the tip ridge line portion of the cleaning blade 62 is turned, various problems such as abnormal noise, vibration, and lack of the tip ridge line portion occur.

  Further, in the present embodiment, as described above, the charging roller 41 in which the unevenness 41c extending along the circumferential direction is formed on the surface is used. If there is unevenness along the circumferential direction of the charging roller 41, it is considered that the unevenness of the contact between the unevenness and the photoconductor 10 does not cause the photoconductor 10 to be uniformly worn but forms fine unevenness. As a result, the frictional force between the cleaning blade 10 and the photosensitive member 10 is increased, the behavior of the tip ridge line portion 62c is not stable, the tip ridge line portion 62c is easily turned over, and abnormal wear and noise are generated. Cheap.

Next, the cleaning blade 62 that is a feature of the present embodiment will be described.
FIG. 8 is a perspective view of the cleaning blade 62 of the present embodiment, and FIG. 9 is an enlarged cross-sectional view of the cleaning blade 62. FIG. 9A is an explanatory diagram showing a state in which the cleaning blade 62 is in contact with the surface of the photosensitive member 10, and FIG. 9B is an enlarged explanatory diagram in the vicinity of the tip ridge line portion 62 c of the cleaning blade 62. .
The cleaning blade 62 includes a strip-shaped holder 621 made of a rigid material such as metal or hard plastic, and a strip-shaped elastic blade 622. The elastic blade 622 is fixed to one end side of the holder 621 with an adhesive or the like, and the other end side of the holder 621 is cantilevered by the case of the cleaning device 30.

  In the cleaning blade 62 of this embodiment, an impregnated portion 62d impregnated with acrylic or / and methacrylic cross-linked resin is formed on the tip ridge line portion of the laminated elastic blade 622 in which the edge layer 622a and the backup layer 622b are laminated. ing. Further, a resin surface layer 623 made of acrylic or / and methacrylic resin having a hardness higher than that of the elastic blade is formed in the blade front end surface 62a and the blade lower surface 62b in the blade longitudinal direction.

The tip ridge portion of the elastic blade 622 is impregnated with acrylic or / and methacrylic crosslinked resin, and an acrylic or / and methacrylic crosslinked resin surface layer having a higher hardness than the elastic blade is provided on the elastic blade surface of the tip ridge portion 62c. Thus, for example, there are the following effects.
The toner removal performance is greatly improved. The wear of the cleaning blade 62 is reduced, and the cleaning performance can be maintained for a long time.
-The coefficient of friction between the cleaning blade 62 and the photosensitive member is reduced.
-The amount of photoconductor wear is reduced, and the life of the photoconductor and the life of the image forming apparatus can be extended.
Since the cleaning blade 62 does not rub the toner additive or the like against the surface of the photoreceptor, there is no occurrence of a white-out abnormal image.

FIG. 10 is a schematic configuration diagram showing the holder 621 and the elastic blade 622.
As shown in FIG. 10, the elastic blade 622 is a laminated blade composed of two layers of an edge layer 622a and a backup layer 622b. The edge layer 622a is a layer that forms a tip ridge line portion that is in direct contact with the photoconductor 10. The edge layer 622a uses a urethane rubber material having higher strength than the backup layer 622b. The 100% modulus value of the edge layer 622a is a combination that is larger than that of the backup layer 622b. As an example of the combination of the edge layer 622a and the backup layer 622b, a urethane rubber material having a 100% modulus (23 ° C.) of 6 to 7 [Mpa] is used as the edge layer 622a, and 4 to 5 [Mpa] as the backup layer 622b. ] Urethane rubber material was used. As for the rubber hardness, urethane rubber with 80 degrees (JISA) was used for the edge layer 622a, and urethane rubber with 75 degrees rubber (JISA) was used for the backup layer 622b. The thickness of the edge layer 622a is 0.5 mm, and the thickness of the backup layer 622b is 1.3 mm.

FIG. 11A is a view showing an example of a cleaning blade using only an elastic blade conventionally used, and FIG. 11B is an enlarged view of a tip ridge line portion.
The cleaning blade shown in FIG. 11 is a cleaning blade made of an elastic blade with a relatively medium hardness having a 100% modulus value of 2.5 [MPa] and a hardness of about 72 degrees.
In such a conventional single-layer cleaning blade, as shown in the drawing, the strength of the tip ridge line portion 62c is low. Therefore, as shown in FIG. 11B, the tip ridge line portion when the photosensitive member 10 is rotationally driven is shown. The deformation is large, the stick slip amount becomes large, and the behavior of the nip (contact portion between the photosensitive member and the cleaning blade) becomes unstable. For this reason, the cleaning property is liable to be deteriorated, and the toner additive or the like is rubbed against the surface of the photoreceptor, and an abnormal white image is generated. In particular, when used in an image forming apparatus that does not have a lubricant application device that applies a lubricant to the surface of the photoconductor 10, abnormal images may be a major issue. In addition, there is a problem that vibration at the tip ridge line portion is large, and the amount of photoconductor film scraping and blade wear increases.

FIG. 12A is a view showing an example of a cleaning blade in which a single-layer elastic blade 622 is impregnated with an impregnation portion 62d impregnated with acrylic and methacrylic and a surface layer 623 made of acrylic or / and methacrylic resin. Yes, (b) is an enlarged view of the tip ridge line portion.
As shown in FIG. 12B, due to the effect of the impregnated portion 62d and the surface layer 623, the strength of the tip ridge line portion 62c is higher than that of the cleaning blade having only the elastic blade shown in FIG. The deformation of the tip ridge line portion 62c can be reduced. Thereby, the amount of stick slip becomes small. Therefore, the nip behavior is stable compared to the cleaning blade shown in FIG. 11, the cleaning property is improved, the toner additive or the like is hardly rubbed against the surface of the photoconductor, and white-out abnormal images are hardly generated. be able to. In addition, since vibration is reduced, there is an effect that the amount of photoconductor film abrasion and blade wear is reduced. However, when used in an image forming apparatus that does not have a lubricant application device for applying a lubricant to the surface of the photoconductor 10, an abnormal white image may occur, which may not be sufficient. there were.

FIG. 13 shows an impregnation portion 62d in which a laminated elastic blade 622 having an edge layer 622a and a backup layer 622b is impregnated with acrylic and methacrylic resin, and a surface layer 623 made of acrylic or / and methacrylic resin. It is a figure which shows the cleaning blade of this embodiment which gave it, (b) is an enlarged view of a front-end | tip ridgeline part.
In the cleaning blade of this embodiment, in addition to the effects of the impregnated part 62d and the surface layer 623, the edge layer 622a made of a high-strength material has the effect of further increasing the strength of the leading edge line part 62c than the cleaning blade shown in FIG. Can be high. Thereby, as shown in FIG.13 (b), the deformation | transformation and vibration of the front-end | tip ridgeline part 62c can be made still smaller, and nip behavior can be stabilized very much. Therefore, a very good cleaning property is obtained, and no white-out abnormal image is generated. Further, even when used in an image forming apparatus that does not have a lubricant application device, white-out abnormal images do not occur. Further, since vibration is minimized, the amount of photoconductor film scraping and blade wear is minimized.

  On the other hand, a single-layer elastic blade 622 made of a high-strength material used in the edge layer was provided with an impregnation portion 62d in which acrylic and methacrylic resins were impregnated, and a surface layer 623 made of acrylic or / and methacrylic resin. In the case of the configuration, the elastic blade 622 becomes too rigid and cannot follow the eccentricity of the photosensitive member 10 or the minute waviness of the surface of the photosensitive member 10, the contact pressure with the photosensitive member is lowered, and the cleaning performance is improved. A decrease may occur. In addition, the contact pressure is likely to be lower than that when a low-strength elastic blade is used even under the influence of settling due to long-term use, and good cleaning properties cannot be obtained over time. Therefore, by using an elastic blade made of an edge layer made of a high-strength material and a backup layer made of a low-strength material as the elastic blade, appropriate elasticity can be given, and the eccentricity of the photoconductor 10 or the photoconductor. 10 cannot follow the minute undulations on the surface, and the contact pressure with the photosensitive member is lowered, so that the cleaning performance can be prevented from being lowered. In addition, since the back-up due to long-term use can prevent a decrease in contact pressure due to the elasticity of the backup layer made of a low-strength material, good cleaning performance can be obtained over a long period of time.

  In particular, as in the present embodiment, the charging roller 41 having the surface provided with the unevenness 41c extending in the circumferential direction is used to form fine unevenness on the photosensitive member 10, and due to this, the cleaning blade 62-photosensitive In the configuration in which the frictional force between the bodies 10 is increased, the configuration shown in FIG. 13 can favorably suppress the turning of the tip ridge line portion 62c and favorably suppress the occurrence of abnormal wear and abnormal noise. it can.

Next, the impregnation treatment of acrylic and methacrylic resin into the elastic blade 622 having a laminated structure and the surface layer 623 will be described.
The impregnation treatment to the tip ridge line portion 62c of the elastic blade 622 can be crosslinked by impregnating acrylic or / and methacrylic monomers by brush coating, spray coating, dip coating or the like. Acrylic or / and methacrylic monomers undergo a crosslinking reaction by applying energy such as heat, light, and electron beam.

  Examples of acrylic and methacrylic monomers used include trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate, HPA-modified trimethylolpropane triacrylate, EO-modified trimethylolpropane triacrylate, and PO-modified trimethylolpropane triacrylate. , Caprolactone modified trimethylolpropane triacrylate, HPA modified trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate (PETTA), glycerol triacrylate, ECH modified glycerol triacrylate, EO modified glycerol triacrylate, PO modified glycerol triacrylate Acrylate, Tris (acryloyl Ethyl) isocyanurate, dipentaerythritol hexaacrylate (DPHA), caprolactone-modified dipentaerythritol hexaacrylate, dipentaerythritol hydroxypentaacrylate, alkyl-modified dipentaerythritol pentaacrylate, alkyl-modified dipentaerythritol tetraacrylate, alkyl-modified dipentaerythritol Examples include triacrylate, dimethylolpropane tetraacrylate (DTMPTA), pentaerythritol ethoxytetraacrylate, EO-modified phosphoric acid triacrylate, 2,2,5,5-tetrahydroxymethylcyclopentanone tetraacrylate, and the like. Or two or more types may be used in combination.

  The surface layer 623 is formed by impregnating the elastic blade 622 with an acrylic or / and methacrylic monomer cross-linked resin and air-drying for a predetermined time, and then spraying, dip coating, screen printing, or the like to form a tip ridge line portion of the cleaning blade 62 62c is covered. The surface layer 623 is preferably covered with a material having a pencil hardness of 7H or higher. Further, the surface layer 623 is made of a member having a hardness higher than that of the elastic blade 622 and is rigid, so that it is difficult to be deformed, and the turning of the front edge line portion 62c of the cleaning blade 62 can be suppressed.

The hardness here can be, for example, Martens hardness measured using a microhardness meter H-100 manufactured by Fischer. In the present embodiment, the elastic blade 622 is about 1 [N / mm ² ], but when a material having a pencil hardness of 7 to 9H used for the surface layer 623 is cured on a glass substrate and measured, 100 to 300 is measured. It was [N / mm ² ], and the hardness was 100 times or more.

  After impregnating the cross-linked resin or after covering with the surface layer 623, the impregnated portion 62d shown in FIG. 9 is formed by heating and irradiating, and the hardness of the tip ridge line portion 62c is increased. A quality effect can be produced. The first possible reason for the effect of the modification is that the crosslinking resin monomer undergoes a crosslinking reaction inside the rubber to form a three-dimensional crosslinked shape, thereby artificially increasing the crosslinking density of the rubber itself. In addition, the wear resistance may be improved. Further, by providing these resins, it is considered that the adhesion and adhesion of the surface layer provided on the surface are further improved and the durability is increased.

  In the cleaning blade 62 of the present embodiment, the elastic blade 622 is impregnated with a crosslinked resin by dip coating, and further, the crosslinked resin for forming the surface layer 623 is spray coated, and then the resin is cured by ultraviolet irradiation. .

  As a timing for applying heat and light energy to cure the impregnated crosslinked resin, it is better to add heat and light energy after the elastic blade 622 is impregnated with the crosslinked resin and before the surface layer 623 is coated. . After impregnating urethane rubber as a base material of the elastic blade 622 with a crosslinking resin, once the impregnation state of the crosslinking resin is fixed by irradiation with heat and light energy, and then a crosslinking resin liquid for forming the surface layer 623 is applied. However, since the impregnation state does not change, the elastic blade 622 in a desired impregnation state can be created.

  9B, the cleaning blade 62 of the present embodiment has such a gradient that the content of the cross-linked resin is reduced with respect to the urethane rubber toward the inside of the elastic blade 622 in the impregnated portion 62d. Impregnation to occur. Specifically, by performing the impregnation operation for a short time or under difficult conditions, the amount of the crosslinked resin to be impregnated is reduced, and the outer side of the elastic blade 622 in the impregnated portion has a large amount of impregnation, The impregnation operation is performed so that the amount of impregnation decreases toward the inside. In this embodiment, the impregnation operation is performed by a dipping method, and the impregnation time is 30 [seconds].

  If the impregnation material (crosslinked resin) penetrates sufficiently to the inside of the base material (urethane rubber of the elastic blade 622), such as performing an impregnation operation for a long time, a kind of equilibrium state is obtained, and the whole has a uniform composition. It is possible to create a state without inclination. However, in this embodiment, the content of the crosslinked resin with respect to the urethane rubber of the elastic blade 622 is given a gradient by suppressing the amount of the crosslinked resin impregnated in the impregnation operation.

  In the cleaning blade 62 of the present embodiment, the surface layer 623 that is harder than the elastic blade 622 is provided, and the friction coefficient between the leading edge portion 62c and the surface of the photoconductor 10 can be reduced.

  In the cleaning blade 62 of the present embodiment, the cross-linked resin exists so as to have a gradient with respect to the base material of the elastic blade 622 inside the surface layer 623 having high hardness. As a result, the mechanical strength and rigidity of the elastic rubber (urethane rubber) serving as the base material is moderately strengthened, and good cleaning can be performed by moderately suppressing the behavior of the blade tip during sliding with the photoreceptor surface. It is possible to exhibit high wear resistance by suppressing the occurrence of abnormal wear and abnormal noise.

  Further, if only the surface layer 623 having a high hardness is provided on the base material of the elastic blade 622, the hardness changes suddenly at the boundary between the high hardness layer and the base material layer, stress concentrates, and the elastic blade 622 may be damaged. There is. On the other hand, by causing the base material of the elastic blade 622 to have a gradient in content, it is possible to suppress a sudden change in hardness at the boundary between the high hardness layer and the base material layer, resulting in stress concentration. Thus, the elastic blade 622 can be prevented from being damaged.

  Patent Document 2 describes a configuration in which only the surface layer 623 is provided, or a configuration in which the base material of the elastic blade 622 is simply impregnated with a resin material. When the configuration is such that only the surface layer is provided, the following problems occur. That is, even if the surface layer 623 is provided to reduce the friction coefficient, the surface layer 623 wears and decreases over time. At this time, if the surface layer 623 is made thick so that it can withstand long-term use, there is a risk that the elastic deformation at the tip ridge line portion 62c of the elastic blade 622 is inhibited, resulting in poor cleaning. On the other hand, if the surface layer 623 is made thin so as not to hinder elastic deformation at the tip ridge line portion 62c of the elastic blade 622, the surface layer 623 is worn to such an extent that the base material is exposed in a short time. When the low-hardness base material is exposed and directly contacts the surface of the photoconductor 10, the friction coefficient between the cleaning blade 62 and the photoconductor surface increases, and abnormal wear or abnormal noise occurs. Further, when the resin material is only impregnated, the hardness of the portion of the cleaning blade 62 that comes into contact with the photosensitive member 10 at the beginning of use cannot be as high as that provided with the surface layer 623, and the abrasion resistance Abrasion becomes insufficient. The cleaning blade 62 described in Patent Document 2 has a pencil hardness of B to 6H, and even if it is used as the surface layer 623, the pencil hardness is not sufficient and the durability is poor. If the surface layer 623 is made thick in order to compensate for this durability, the posture control of the edge (tip ridge line portion) is impaired, and the durability is lowered.

  Patent Document 3 describes a configuration in which the elastic blade 622 is impregnated with a silicone-containing cross-linked resin with a gradient, and the surface of the elastic blade 622 is covered with the resin. Since the cleaning blade 62 described in Patent Document 3 covers the surface of the elastic blade 622 with the impregnated cross-linked resin, it is different from the cleaning blade 62 of the present embodiment in which the surface layer 623 is provided separately from the impregnated one. . In addition, the silicone-containing crosslinked resin is inferior in durability to the resin (acrylic or / and methacrylic monomer crosslinked resin) used for the surface layer 623 of the present embodiment. Furthermore, if the impregnation is performed for 12 hours as in the impregnation operation described in Patent Document 3, the amount of the impregnated cross-linked resin becomes excessive, the base rubber swells too much, the rubber network structure is destroyed, and the mechanical strength is reduced. The durability is lowered.

  On the other hand, the cleaning blade 62 of the present embodiment covers the surface with a surface layer 623 made of a cross-linked resin having a pencil hardness of 7H or more, and the elastic blade 622 is impregnated with the cross-linked resin with an inclination. Since the elastic blade 622 contains a cross-linked resin to increase the hardness, durability over time can be ensured even if the thickness of the surface layer 623 is reduced. Due to the extremely thin film thickness and high pencil hardness of the surface layer 623, it is possible to achieve high durability that enables the posture control and durability of the tip ridge line portion 62c to be expressed simultaneously. Further, by suppressing the amount of the crosslinked resin impregnated to be contained in the elastic blade 622, it is possible to achieve both the reduction of the rubber mechanical strength due to swelling of the base rubber and the strengthening of the network structure due to the infiltration of the high hardness resin material. .

  In addition to the above, in the present embodiment, the elastic blade 622 is composed of two layers of a backup layer 622b and an edge layer 622a having a 100% modulus value higher than that of the backup layer 622b constituting the tip ridge line portion 62c. By using the laminated blade, it is possible to further increase the strength of the tip ridge line portion, and to further favorably control the posture of the edge (tip ridge line portion).

  As described above, in the present embodiment, since the hardness of the tip ridge line portion 62c of the elastic blade 622 is increased by the impregnation treatment, the tip ridge line portion 62c of the elastic blade 622 is hardly deformed. In particular, in this embodiment, since the elastic blade 622 has a two-layer structure and the strength of the edge layer 622a constituting the tip ridge line portion 62c is increased, the elastic blade 622 is more difficult to deform.

  For this reason, when the surface layer 623 having higher hardness than the elastic blade 622 is formed on the entire surface of the blade lower surface 62b (edge layer 622a) of the elastic blade 622, the surface layer 623 formed on the blade lower surface 62b becomes the tip edge line of the elastic blade 622. The elastic deformation of the portion 62c on the surface of the photosensitive member is hindered, and the restoring force for the elastic deformation acting in the direction of increasing the contact pressure on the surface of the photosensitive member at the tip ridge line portion 62c is hardly obtained. As a result, the leading edge ridge line portion 62c cannot follow the eccentricity and minute waviness of the photoconductor 10. Accordingly, the contact pressure with respect to the photoconductor 10 fluctuates, and the contact pressure decreases under severe conditions such as receiving a large pressing force from the toner dammed to the leading edge portion 62c, such as during continuous solid image formation. Then, the toner may slip through the cleaning blade 62 and cause a cleaning failure.

For such a problem, it may be considered that the surface layer 623 is not formed on the blade lower surface 62 b of the elastic blade 622. However, when the surface layer 623 is not formed on the blade lower surface 62b, the tip ridge line portion 62c of the elastic blade 622 is greatly elastically deformed in the surface movement direction of the photosensitive member 10, and the tip ridge line portion 62c is turned up. Wear may occur.
Therefore, in the present embodiment, the surface layer 623 is formed on both the blade tip surface 62a and the blade lower surface 62b so that the film thickness becomes 1 [μm] or less at a position of 50 [μm] from the tip ridge line portion 62c. . Accordingly, it is possible to suppress elastic deformation of the tip ridge line portion 62c in the surface movement direction of the photosensitive member 10 as compared with the case where the surface layer 623 is formed only on the blade tip surface 62a. Further, by forming the surface layer 623 so that the film thickness becomes 1 [μm] or less at a position of 50 [μm] from the leading edge portion 62c, even if the photoreceptor 10 is decentered, the elastic blade 622 is formed. Due to the restoring force against the elastic deformation of the tip ridge line portion 62c, the tip ridge line portion 62c can be made to follow the surface of the photoreceptor 10, and good cleaning properties can be maintained.

Further, as the material of the surface layer 623, an acrylic or / and methacrylic monomer of the same kind as that of the impregnating material is applied, and an energy such as heat, light, electron beam or the like is applied to provide a crosslinked surface layer.
As the photocrosslinking resin, it is preferable to use a monomer having a main skeleton of pentaerythritol triacrylate having a functional group equivalent molecular weight of 350 or less and a functional group number of 3 to 6. If the functional group equivalent molecular weight exceeds 350, or a material other than the pentaerythritol triacrylate skeleton is used, the surface layer 623 may become too brittle. When the surface layer 623 becomes brittle, the leading edge portion 62c of the cleaning blade 62 is turned over, leading to wear of the leading edge as shown in FIG. 9B, and the cleaning performance for a long time cannot be maintained.

  Further, as a material for the surface layer 623, it is preferable to appropriately mix an acrylate material having a functional group equivalent molecular weight of 100 to 1000 and a functional group number of 1 to 2 in addition to the pentaerythritol / triacrylate skeleton material. Thus, flexibility can be imparted to the surface layer 623, and the properties of the surface layer 623 can be customized in accordance with the characteristics of the machine on which the cleaning blade 62 is mounted. Therefore, it is possible to improve environmental characteristics and the like, for example, by finely adjusting the blade behavior when abnormal noise occurs in a specific environment.

Next, a specific example of a material used for the impregnation treatment / formation treatment of the surface layer 623 will be described.
Specific examples of the curable material used for the impregnation process and the surface layer 623 formation process include the following curable materials 1 to 7.

<Curing material 1>
Monomer: Daicel Cytec Co., Ltd. PETIA 10 parts Polymerization initiator: Ciba Specialty Chemicals Co., Ltd. Irgacure 184 1 part Solvent: 2-butanone 89 parts Crosslinking method: Photocrosslinking (metal halide lamp)
Irradiation intensity: 500 mW / cm2 (365 nm)
Irradiation time: Light irradiation under the condition of 60 seconds

<Curing material 2>
Monomer 1: Daicel Cytec Co., Ltd. PETIA 9 parts Monomer 2: Daicel Cytec Co., Ltd. HDDA 1 part Polymerization initiator: Ciba Specialty Chemicals Co., Ltd. Irgacure 184 1 part Solvent: 2-butanone 89 parts Crosslinking method: Photocrosslinking (metal halide lamp)
Irradiation intensity: 500 mW / cm2 (365 nm)
Irradiation time: Light irradiation under the condition of 60 seconds

<Curing material 3>
Monomer 1: Daicel Cytec Co., Ltd. PETIA 7 parts Monomer 2: Daicel Cytec Co., Ltd. ODA-N 3 parts Polymerization initiator: Ciba Specialty Chemicals Co., Ltd. Irgacure 184 1 part Solvent: 2-butanone 89 parts Crosslinking method: Photocrosslinking (metal halide lamp) )
Irradiation intensity: 500 mW / cm2 (365 nm)
Irradiation time: Light irradiation under the condition of 60 seconds

<Curing material 4>
Monomer 1: Daicel Cytec Co., Ltd. PETIA 2 parts Monomer 2: Negami Kogyo UN-2700 8 parts Polymerization initiator: Ciba Specialty Chemicals Irgacure 184 1 part Solvent: 2-butanone 89 parts
Crosslinking method: Photocrosslinking (metal halide lamp)
Irradiation intensity: 500 mW / cm2 (365 nm)
Irradiation time: Light irradiation under the condition of 60 seconds

<Curing material 5>
Monomer 1: Daicel Cytec Corporation DPHA 10 parts Polymerization initiator: Ciba Specialty Chemicals Co., Ltd. Irgacure 184 1 part Solvent: 2-butanone 89 parts Crosslinking method: Photocrosslinking (metal halide lamp)
Irradiation intensity: 500 mW / cm2 (365 nm)
Irradiation time: Light irradiation under the condition of 60 seconds

<Curing material 6>
Monomer: Nippon Kayaku DPCA-120 10 parts Polymerization initiator: Ciba Specialty Chemicals Irgacure 184 1 part Solvent: 2-butanone 89 parts Crosslinking method: Photocrosslinking (metal halide lamp)
Irradiation intensity: 500 mW / cm2 (365 nm)
Irradiation time: Light irradiation under the condition of 60 seconds

溶媒：２−ブタノン ９０部
架橋方法 ： 熱架橋
架橋温度 ： １３０度
架橋時間 ： ２０分 <Curing material 7>
Monomer 1: Sumika Bayer Sumijoule HT <HDI adduct> 8 parts Monomer 2: Made by Kanto Chemical Co. 2 parts polyol

Solvent: 90 parts of 2-butanone
Crosslinking method: Thermal crosslinking Crosslinking temperature: 130 degrees Crosslinking time: 20 minutes

  After immersing the laminated blade in any of the cured materials 1 to 7 for a predetermined time (30 [seconds]) as an impregnating material, it is air-dried for 3 minutes. Further, a surface layer 623 made of the above-mentioned curable material was formed by a spray coating method. Specifically, for each elastic blade made of urethane rubber appropriately impregnated, the film thickness is 1 μm at a spray gun moving speed of 10 mm / s from the blade tip surface by spray coating. The overcoat was applied over the entire tip. After touch-drying for 3 minutes, the lower surface of the blade was applied by spray coating. Thereafter, touch-drying is further performed for 3 minutes, and light irradiation and thermosetting are performed under the above-described conditions, whereby the cleaning blade 62 including the impregnated portion 62d and the surface layer 623 can be obtained.

Next, the photoconductor 10 will be described.
The photoreceptor 10 has at least a photosensitive layer and a surface layer on a conductive support, and the surface layer has inorganic fine particles dispersed in a resin.

First, the layer structure in the photoreceptor 10 of the present embodiment will be described.
FIG. 14A shows an example of a cross section of the photoreceptor 10 in which a photosensitive layer 92 containing inorganic fine particles is provided near the surface on a conductive support 91. FIG. 14B shows an example of a cross section of the photoreceptor 10 in which a photosensitive layer 92 and a surface layer 93 containing inorganic fine particles are provided on a conductive support 91. FIG. 14C is an example showing a cross section of the photoreceptor 10 in which a charge generation layer 921, a photosensitive layer 92 in which a charge transport layer 922 is laminated, and a surface layer 93 containing inorganic fine particles are provided on a conductive support 91. is there. FIG. 14D shows a photoreceptor 10 in which an undercoat layer 94 is provided on a conductive support 91, a photosensitive layer 92 in which a charge generation layer 921 and a charge transport layer 922 are laminated, and a surface layer 93 containing inorganic fine particles. It is an example which shows the cross section.

  The photoreceptor 10 of the present embodiment preferably has at least a photosensitive layer 92 and a surface layer 93 on a conductive support 91, and other layers and the like may be arbitrarily combined.

  By containing fine particles in the surface layer 93 of the photoconductor 10, the wear resistance of the surface of the photoconductor is improved. In particular, in the present embodiment, the charging roller 41 having the unevenness 41c extending in the circumferential direction on the surface is used, and the photoreceptor 10 is uniformly worn by the unevenness in the circumferential direction of the charging roller 41. Without the above, fine irregularities may be formed. By containing fine particles in the surface layer 93 of the photoconductor 10 and improving the wear resistance of the photoconductor surface, it is possible to suppress the formation of fine irregularities as described above on the photoconductor surface. Thereby, it is possible to satisfactorily suppress an increase in the frictional force between the cleaning blade 62 and the photosensitive member 10, the tip ridge line portion 62 c can be prevented from turning over, and the occurrence of abnormal wear and abnormal noise can be suppressed. .

  Further, when the surface layer 93 contains fine particles, fine irregularities due to the presence or absence of fine particles are generated on the surface of the photoreceptor. If there are fine irregularities, a gap is formed between the cleaning blade and the surface of the photoconductor, so that the toner additive is not easily sandwiched between the cleaning blade and the surface of the photoconductor, and is not easily rubbed on the surface of the photoconductor. As a result, it is possible to prevent white-out abnormal images due to rubbing of the toner additive on the surface of the photoreceptor. On the other hand, since the surface of the photoconductor without fine particles is smooth, there is no gap between the cleaning blade and the surface of the photoconductor, and the toner additive is sandwiched between the blade and the photoconductor and is easily rubbed against the surface of the photoconductor. .

Examples of the conductive support 91 include those having a volume resistance of 10 ¹⁰ Ω · cm or less, for example, metals such as aluminum, nickel, chromium, nichrome, copper, gold, silver, platinum, tin oxide, indium oxide, etc. The metal oxide of the above is coated with film or cylindrical plastic or paper by vapor deposition or sputtering, or a plate made of aluminum, aluminum alloy, nickel, stainless steel or the like and extruded by drawing or drawing. After pipe formation, surface treatment pipes such as cutting, superfinishing, and polishing can be used.

  Further, the endless nickel belt and the endless stainless steel belt disclosed in Patent Document 4 can also be used as the conductive support 91. In addition, a conductive support 91 may be used in which conductive powder is dispersed in a suitable binder resin and coated on a support to form a conductive layer. Examples of the conductive powder include carbon black, acetylene black, metal powder such as aluminum, nickel, iron, nichrome, copper, zinc and silver, or metal oxide powder such as conductive tin oxide and ITO. . The binder resin used at the same time is polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer. , Polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, Examples thereof include thermoplastic, thermosetting resins, and photocurable resins such as melamine resin, urethane resin, phenol resin, and alkyd resin.

  Such a conductive layer can be provided by dispersing and coating these conductive powder and binder resin in a suitable solvent such as tetrahydrofuran, dichloromethane, methyl ethyl ketone, and toluene. Furthermore, it is electrically conductive by a heat-shrinkable tube in which the conductive powder is contained in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, Teflon (registered trademark) on a suitable cylindrical substrate. Those provided with a conductive layer can also be used favorably as the conductive support 91.

Next, the photosensitive layer 92 will be described.
The photosensitive layer 92 may be a single layer as shown in FIGS. 14 (a) and 14 (b) or a laminate as shown in FIGS. 14 (c) and 14 (d). A photoconductor having the configuration example shown in FIGS. 14C and 14D, which includes the charge generation layer 921 and the charge transport layer 922, will be described.

The charge generation layer 921 is a layer mainly composed of a charge generation material. A known charge generation material can be used for the charge generation layer 921, and representative examples thereof include monoazo pigments, disazo pigments, trisazo pigments, perylene pigments, perinone pigments, quinacridone pigments, and quinone condensed polycycles. Examples thereof include compounds, squalic acid dyes, other phthalocyanine pigments, naphthalocyanine pigments, and azulenium salt dyes. These charge generation materials may be used alone or in combination of two or more. In the present embodiment, in particular, an azo pigment and / or a phthalocyanine pigment is effectively used.
In particular, an azo pigment represented by the following structural formula (1) and titanyl phthalocyanine (particularly at least 27.2 as a diffraction peak (± 0.2 °) with a Bragg angle 2θ with respect to the characteristic X-ray (wavelength 1.514Å) of CuKα). (Titanyl phthalocyanine) having a maximum diffraction peak at 0 ° can be used effectively.

  The charge generation layer 921 is dispersed in a suitable solvent together with a binder resin as necessary using a ball mill, attritor, sand mill, ultrasonic wave, etc., and this is applied onto the conductive support 91 and dried. It is formed by. As the binder resin used for the charge generation layer 921 as necessary, polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, polysulfone, poly-N -Vinylcarbazole, polyacrylamide, polyvinyl benzal, polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyamide, polyvinyl pyridine, cellulose resin, casein, polyvinyl alcohol, polyvinyl pyrrolidone, etc. Can be mentioned. The amount of the binder resin is suitably 0 to 500 parts by weight, preferably 10 to 300 parts by weight with respect to 100 parts by weight of the charge generating material. Examples of the solvent used here include isopropanol, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane, monochlorobenzene, cyclohexane, toluene, xylene, and ligroin. In particular, ketone solvents, ester solvents, and ether solvents are preferably used.

  The charge generation layer 921 is formed by applying on the conductive support 91. As the coating method, methods such as dip coating, spray coating, beat coating, nozzle coating, spinner coating, and ring coating can be used. The thickness of the charge generation layer 921 is suitably about 0.01 to 5 μm, preferably 0.1 to 2 μm.

  The charge transport layer 922 can be formed by dissolving or dispersing a charge transport material and a binder resin in an appropriate solvent, and applying and drying the solution on the charge generation layer 921. Moreover, a plasticizer, a leveling agent, antioxidant, etc. can also be added as needed. Charge transport materials include hole transport materials and electron transport materials.

  Examples of the electron transporting material include chloroanil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4 , 5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-tri Examples thereof include electron-accepting substances such as nitrodibenzothiophene-5,5-dioxide and benzoquinone derivatives.

  Examples of the hole transport material include poly-N-vinylcarbazole and derivatives thereof, poly-γ-carbazolylethyl glutamate and derivatives thereof, pyrene-formaldehyde condensates and derivatives thereof, polyvinylpyrene, polyvinylphenanthrene, polysilane, oxazole derivatives, Oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triarylmethane derivatives, 9-styrylanthracene derivatives, pyrazolines Derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, etc., bisstilbene derivatives, enamine derivatives, etc. Other known materials may be mentioned.

These charge transport materials may be used alone or in combination of two or more.
As the binder resin, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, Polyvinylidene chloride, polyarate, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol Examples thereof include thermoplastic or thermosetting resins such as resins and alkyd resins.

  As the solvent, tetrahydrofuran, dioxane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, methyl ethyl ketone, acetone or the like is used.

  The amount of the charge transport material is appropriately 20 to 300 parts by weight, preferably 40 to 150 parts by weight with respect to 100 parts by weight of the binder resin. The thickness of the charge transport layer 922 is preferably 25 μm or less from the viewpoint of resolution and responsiveness. Regarding the lower limit, although it differs depending on the system to be used (particularly the charging potential), it is preferably 5 μm or more.

Further, a plasticizer or a leveling agent may be added to the charge transport layer 922.
As the plasticizer, those used as general plasticizers such as dibutyl phthalate and dioctyl phthalate can be used as they are, and the amount used is suitably about 0 to 30% by weight based on the binder resin.

  As the leveling agent, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, polymers or oligomers having a perfluoroalkyl group in the side chain are used, and the amount used is 0 to 0 with respect to the binder resin. 1% by weight is suitable.

  When the charge transport layer 922 is the outermost layer, the charge transport layer 922 contains inorganic fine particles. Inorganic fine particles include metal powders such as copper, tin, aluminum and indium, silicon oxide, silica, tin oxide, zinc oxide, titanium oxide, indium oxide, antimony oxide, bismuth oxide, tin oxide doped with antimony, tin And metal materials such as indium oxide doped with silicon and inorganic materials such as potassium titanate. In particular, metal oxides are good, and silicon oxide, aluminum oxide, titanium oxide and the like can be used effectively.

The average primary particle size of the inorganic fine particles is preferably 0.01 to 0.5 μm from the viewpoint of light transmittance and wear resistance of the surface layer (charge transport layer 922).
When the average primary particle size of the inorganic fine particles is 0.01 μm or less, it causes a decrease in wear resistance and a dispersibility. Or toner filming may occur.

  The higher the amount of inorganic fine particles added, the better the wear resistance and the better. However, if it is too high, the residual potential increases, the writing light transmittance of the charge transport layer 922 decreases, and side effects may occur. Therefore, it is generally 30% by weight or less, preferably 20% by weight or less, based on the total solid content. The lower limit is usually 3% by weight.

  Further, these inorganic fine particles can be surface-treated with at least one kind of surface treatment agent, and it is preferable from the viewpoint of dispersibility of the inorganic fine particles. A decrease in the dispersibility of inorganic fine particles not only increases the residual potential, but also decreases the transparency of the coating film, the occurrence of coating film defects, and a decrease in wear resistance. It can develop into a big problem to hinder.

Next, the case where the photosensitive layer 92 shown in FIGS. 14A and 14B has a single layer structure will be described.
The single photosensitive layer 92 is obtained by dispersing the above-described charge generating material in a binder resin. The single-layer photosensitive layer 92 can be formed by dissolving or dispersing a charge generation material, a charge transport material, and a binder resin in an appropriate solvent, and applying and drying the solution. In addition, as shown in FIG. 14A, when the single photosensitive layer 92 is a surface layer, it contains inorganic fine particles.

  Further, the photosensitive layer 92 may be a function separation type to which the above-described charge transport material is added, and can be used satisfactorily. Moreover, a plasticizer, a leveling agent, antioxidant, etc. can also be added as needed.

As the binder resin, the binder resin previously mentioned in the charge transport layer 922 may be used as it is, or the binder resin mentioned in the charge generation layer may be mixed and used.
The amount of the charge generating material with respect to 100 parts by weight of the binder resin is preferably 5 to 40 parts by weight, and the amount of the charge transporting material is preferably 0 to 190 parts by weight, and more preferably 50 to 150 parts by weight.

  The single-layer photosensitive layer 92 is formed by immersing a coating solution in which a charge generating material and a binder resin are dispersed together with a charge transporting material, if necessary, using a solvent such as tetrahydrofuran, dioxane, dichloroethane, and cyclohexane with a disperser or the like. It can be formed by spray coating or bead coating. The film thickness of the single photosensitive layer 92 is suitably about 5 to 25 μm.

In the photoreceptor 10 of this embodiment, an undercoat layer 94 may be provided between the conductive support 91 and the photosensitive layer 92 as shown in FIG.
The undercoat layer 94 generally contains a resin as a main component. However, considering that the photosensitive layer 92 is applied with a solvent thereon, these resins are resins having high solvent resistance with respect to general organic solvents. It is desirable.

  Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane, melamine resin, phenol resin, alkyd-melamine resin, and epoxy. Examples thereof include a curable resin that forms a three-dimensional network structure such as a resin.

  Further, in order to prevent moire and reduce residual potential, the undercoat layer 94 may be added with fine powder pigments of metal oxides exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide and the like. Good. The undercoat layer 94 can be formed using an appropriate solvent and coating method like the photosensitive layer 92 described above.

Furthermore, as the undercoat layer 94, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can be used. In addition, the undercoat layer 94 is formed by anodizing Al ₂ O ₃ , organic materials such as polyparaxylylene (parylene), SiO ₂ , SnO ₂ , TiO ₂ , ITO, CeO _2, etc. What provided the inorganic substance by the vacuum thin film preparation method can also be used favorably. In addition, known ones can be used. The thickness of the undercoat layer 94 is suitably 0 to 5 μm.

  In the photoreceptor 10 of this embodiment, as shown in FIGS. 14B, 14C, and 14D, a surface layer 93 containing inorganic fine particles on the outermost surface of the photosensitive layer 92 is provided. The thing which provides is preferable.

  The surface layer 93 is composed of at least inorganic fine particles and a binder resin. As the binder resin, a thermoplastic resin such as polyarylate resin or polycarbonate resin, or a crosslinked resin such as urethane resin or phenol resin is used.

  As the fine particles, organic fine particles and inorganic fine particles are used. Examples of the organic fine particles include fluorine-containing resin fine particles and carbon-based fine particles. Metal powder such as copper, tin, aluminum, indium, silicon oxide, silica, tin oxide, zinc oxide, titanium oxide, indium oxide, antimony oxide, bismuth oxide, tin oxide doped with antimony, tin doped Examples thereof include metal oxides such as indium oxide and inorganic materials such as potassium titanate. In particular, metal oxides are good, and silicon oxide, aluminum oxide, titanium oxide and the like can be used effectively.

The average primary particle size of the inorganic fine particles is preferably 0.01 to 0.5 μm from the viewpoint of the light transmittance and wear resistance of the surface layer 93. When the average primary particle size of the inorganic fine particles is 0.01 μm or less, the abrasion resistance and the dispersibility are deteriorated. When the average primary particle size is 0.5 μm or more, the settling properties of the inorganic fine particles are promoted in the dispersion. Or toner filming may occur.

  The higher the concentration of the inorganic fine particles in the surface layer 93, the higher the wear resistance and the better. However, if it is too high, the residual potential increases, the write light transmittance of the protective layer decreases, and side effects may occur. . Therefore, it is approximately 50% by weight or less, preferably 30% by weight or less, based on the total solid content. The lower limit is usually 5% by weight.

Further, these inorganic fine particles can be surface-treated with at least one kind of surface treatment agent, and it is preferable from the viewpoint of dispersibility of the inorganic fine particles. A decrease in the dispersibility of inorganic fine particles not only increases the residual potential, but also decreases the transparency of the coating film, the occurrence of coating film defects, and a decrease in wear resistance. It can develop into a big problem to hinder. As the surface treatment agent, a conventionally used surface treatment agent can be used, but a surface treatment agent capable of maintaining the insulating properties of the inorganic fine particles is preferable. For example, a titanate coupling agent, an aluminum coupling agent, a zircoaluminate coupling agent, a higher fatty acid, etc., or a mixing treatment of these with a silane coupling agent, Al ₂ O ₃ , TiO ₂ , ZrO ₂ , Silicone, aluminum stearate, or the like, or a mixture thereof is more preferable from the viewpoint of dispersibility of inorganic fine particles and image blur.

  The treatment with the silane coupling agent is strongly influenced by image blur, but the influence may be suppressed by performing a mixing treatment of the surface treatment agent and the silane coupling agent. The surface treatment amount varies depending on the average primary particle size of the inorganic fine particles used, but is preferably 3 to 30 wt%, more preferably 5 to 20 wt%. If the surface treatment amount is less than this, the dispersion effect of the inorganic fine particles cannot be obtained, and if it is too much, the residual potential is significantly increased.

  These inorganic fine particle materials may be used alone or in combination of two or more. The thickness of the surface layer 93 is preferably in the range of 1.0 to 8.0 μm. It is preferable that the photoconductor 10 that is repeatedly used for a long period of time has high mechanical durability and is not easily worn. However, ozone, NOx gas, and the like are generated from the charging member or the like in the actual machine and adhere to the surface of the photoreceptor. When these deposits are present, image flow occurs. In order to prevent this image flow, it is necessary to wear the photosensitive layer 92 at a certain speed or higher. For that purpose, it is preferable that the surface layer 93 has a film thickness of at least 1.0 μm or more in consideration of long-term repeated use. Moreover, when the surface layer 93 film thickness is larger than 8.0 μm, it is considered that the residual potential increases and the fine dot reproducibility decreases.

  These inorganic fine particle materials can be dispersed by using an appropriate disperser. The average particle size of the inorganic fine particles in the dispersion is preferably 1 μm or less, and preferably 0.5 μm or less from the viewpoint of the transmittance of the surface layer 93.

  As a method of providing the surface layer 93 on the photosensitive layer 92, a dip coating method, a ring coating method, a spray coating method, or the like is used. Among these, a general method for forming the surface layer 93 is to form a coating film by ejecting paint from a nozzle having a minute opening and depositing fine droplets generated by atomization on the photosensitive layer 92. A spray coating method is used.

  As the solvent used here, tetrahydrofuran, dioxane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, methyl ethyl ketone, acetone and the like are used.

  Further, the surface layer 93 may contain a charge transport material in order to reduce residual potential and improve responsiveness. As the charge transport material, the materials described in the description of the charge transport layer can be used. When a low molecular charge transport material is used as the charge transport material, it may have a concentration gradient in the surface layer 93.

  For the surface layer 93, a polymer charge transport material having a function as a charge transport material and a function of a binder resin is also preferably used. The surface layer 93 composed of these polymer charge transport materials is excellent in wear resistance. A known material can be used as the polymer charge transport material, but at least one polymer selected from polycarbonate, polyurethane, polyester, and polyether is preferable. In particular, a polycarbonate containing a triarylamine structure in the main chain and / or side chain is preferable.

The photoreceptor surface hardness is preferably a Martens hardness of 190 N / mm ² or more and an elastic power (We / Wt value) of 37.0% or more.
The Martens hardness and the elastic power increased here are measured under the following conditions.
Evaluation device: Fisherscope H-100
Test method: Load unloading repetition (one time) Test indenter: Micro Vickers indenter Maximum load: 9.8 mN
Load (unloading) time: 30 seconds Holding time: 5 seconds

  The Martens hardness is measured by using a micro hardness meter while pushing the micro Vickers indenter with a constant force, for example, 30 seconds, holding it for 5 seconds, and pulling it with the constant force for 30 seconds. The elastic power is Wlast (Wt value) when the integrated stress when the micro Vickers indenter is pushed in, and the last stress at the test load unloading temple is Welast (We value). A characteristic value defined by an expression. A higher elastic power indicates less plastic deformation, that is, higher rubber properties. If the elastic power is too low, it is closer to glass than rubber.

By setting the Martens hardness to 190 N / mm ² or more, as shown in the verification experiment, it is possible to suppress the surface of the photosensitive member from being damaged and to suppress the occurrence of a white-out image due to toner fixation.

  The void image on the photoconductor is generated by the fixing of the toner base component and the toner additive, but the toner base component and the additive are caught by minute scratches on the surface of the photoconductor. It is known that it occurs by stinging.

  Since the photosensitive member forms an image while being constantly in contact with a developing machine, a transfer belt, a charging roller, a cleaning blade, etc., fine scratches are generated. While the number of images formed is small, these fine scratches are like so-called scratches, and by suppressing the occurrence of scratches, white-out images due to sticking of the toner base component and additive component are suppressed. Will lead to.

By increasing the Martens hardness, it becomes difficult to scratch the surface of the photoreceptor, and as shown in the verification experiment described later, the surface of the photoreceptor is scratched over time by setting the Martens hardness to 190 N / mm ² or more. And the occurrence of abnormal white spots due to toner fixation can be prevented. Martens hardness is an index indicating the degree of hardness with the "load" required to scratch a measurement object with a micro Vickers indenter and create a dent of a certain depth, and indicates whether scratches are likely to occur. The index value is optimal.

  Further, when the elastic power (We / Wt value) is less than 37.0%, as shown in a verification experiment described later, when the image area ratio changes in the direction of the photoreceptor axis, the photoreceptor wear speed is low This causes a problem that wear unevenness occurs. For this reason, hardness and elastic work rate are controlled by the addition amount of inorganic fine particles and the resin type. Resins such as polycarbonate and polyarylate are improved in hardness and elastic power by incorporating a rigid structure into the resin skeleton. Further, by adopting the polymer charge transport material, the hardness and elastic power are improved.

Next, five photoconductors 1 to 5 having different surface layers were prepared, and the results of examining the Martens hardness and power are shown.
[Support]
An aluminum support (outer diameter 40 mmΦ) base tube was used.

[Underlayer]
The undercoat layer was formed on the support by coating by dipping so that the film thickness after drying was 3.5 μm.
Undercoat layer coating solution / alkyd resin: Beckosol 1307-60-EL: Dainippon Ink Chemical Co., Ltd./melamine resin: Super Becamine G-821-60: Dainippon Ink Chemical Co., Ltd./Titanium oxide: CR-EL: Ishihara Sangyo )
-Methyl ethyl ketone mixing ratio (weight): alkyd resin / melamine resin / titanium oxide / methyl ethyl ketone = 3/2/20/100

混合比（重量）：ビスアゾ顔料／ポリビニルブチラール／テトラヒドロフラン＝５／（１／１００）／２００ [Charge generation layer]
On the undercoat layer, a charge generation layer coating solution containing a bisazo pigment having the following structure was dip coated and dried by heating to form a charge generation layer having a thickness of 0.2 μm.
Charge generation layer coating solution ・ Bisazo pigment with the structure shown in the chemical formula 2 below ・ Polyvinyl butyral (XYHL: UCC)
・ 2-butanone cyclohexanone

Mixing ratio (weight): bisazo pigment / polyvinyl butyral / tetrahydrofuran = 5 / (1/100) / 200

混合比（重量）：ポリカーボネート／電荷輸送物質／テトラヒドロフラン＝１／１／１０ [Charge transport layer]
On this charge generation layer, a charge transport layer coating solution containing a low molecular charge transport material having the following structure was dip-coated and heat-dried to obtain a charge transport layer having a thickness of 22 μm.
Charge transport layer coating liquid / charge transport layer coating liquid: bisphenol Z-type polycarbonate, low molecular charge transport material having the structure shown in Chemical Formula 3 below, tetrahydrofuran

Mixing ratio (weight): polycarbonate / charge transport material / tetrahydrofuran = 1/1/10

[Surface layer 1]
Low molecular charge transport material used for surface layer 1 coating liquid / surface layer coating liquid charge transport layer: Bisphenol Nor type polycarbonate (TS2050: Teijin Chemicals)
・ Silica fine particles (KMPX100: manufactured by Shin-Etsu Chemical)
Tetrahydrofuran / cyclohexanone mixing ratio (weight): charge transport material / polycarbonate / silica fine particles / tetrahydrofuran / cyclohexanone = 3/4/3/170/50

[Surface layer 2]
Low molecular charge transport material used for surface layer 2 coating liquid / surface layer coating liquid charge transport layer: Bisphenol A type Z polycarbonate (TS2050: Teijin Kasei)
・ Alumina fine particles (AA03: manufactured by Sumitomo Chemical)
Tetrahydrofuran / cyclohexanone mixing ratio (weight): charge transport material / polycarbonate / alumina fine particle / tetrahydrofuran / cyclohexanone = 3/4/3/170/50

[Surface layer 3]
Low molecular charge transport material used for surface layer 3 coating liquid / surface layer coating liquid charge transport layer: Bisphenol A type polycarbonate (TS2040: Teijin Chemicals)
・ Alumina fine particles (AA03: manufactured by Sumitomo Chemical)
Tetrahydrofuran / cyclohexanone mixing ratio (weight): charge transport material / polycarbonate / alumina fine particles / tetrahydrofuran / cyclohexanone

混合比（重量）：高分子電荷輸送物質／アルミナ微粒子／テトラヒドロフラン／シクロヘキサノン＝７／３／１７０／５０ [Surface layer 4]
Low molecular charge transport material used for surface layer 4 coating liquid / surface layer coating liquid charge transport layer: high molecular charge transport material having structure shown in chemical formula 4 below (n = 2, m = 3, viscosity average molecular weight 65000) )
・ Alumina fine particles (AA03: manufactured by Sumitomo Chemical)
・ Tetrahydrofuran ・ Cyclohexanone

Mixing ratio (weight): polymer charge transport material / alumina fine particle / tetrahydrofuran / cyclohexanone = 7/3/170/50

[Surface layer 5]
Low molecular charge transport material used for surface layer 5 coating liquid / surface layer coating liquid charge transport layer: Bisphenol Nor type polycarbonate (TS2050: Teijin Chemicals)
Tetrahydrofuran / cyclohexanone mixing ratio (weight): charge transport material / polycarbonate / tetrahydrofuran / cyclohexanone = 4/5/170/50

[Photoreceptor 1]
Using the coating solution for surface layer 1 containing the low molecular charge transport material used for the charge transport layer on the charge transport layer, spray coating is performed under the following conditions, followed by heating and drying at 150 ° C. for 20 minutes, and a photoreceptor. 1 was formed.

[Photoreceptor 2]
Using the coating solution for surface layer 2 containing the low-molecular charge transport material used for the charge transport layer on the charge transport layer, spray coating is performed under the following conditions, followed by heating and drying at 150 ° C. for 20 minutes. 2 was formed.

[Photoreceptor 3]
Using the coating solution for surface layer 3 containing the low molecular charge transport material used for the charge transport layer on the charge transport layer, spray coating is performed under the following conditions, followed by heating and drying at 150 ° C. for 20 minutes, and a photoreceptor. 3 was formed.

[Photosensitive member 4]
Using the coating solution for surface layer 4 containing the low-molecular charge transport material used for the charge transport layer on the charge transport layer, spray coating is performed under the following conditions, followed by heating and drying at 150 ° C. for 20 minutes, and a photoreceptor. 4 was formed.

[Photoreceptor 5]
Using the coating solution for surface layer 5 containing the low-molecular charge transport material used for the charge transport layer on the charge transport layer, spray coating is performed under the following conditions, followed by heating and drying at 150 ° C. for 20 minutes, and a photoreceptor. 5 was formed.

  The Martens hardness and elastic work rate (We / Wt value) of the photoconductor were measured using a fine surface hardness tester H-100 manufactured by Fisherscope of the surface of the photoconductor produced. The results are shown in Table 1.

  With respect to the photoreceptors 1 to 5 shown in Table 1 above, an experiment for confirming the presence or absence of occurrence of an abnormal white spot image was performed when the toner or toner additive adhered to the photoreceptor surface.

<Verification Experiment 1: Experiment for Confirming Existence of White Spots-1>
Whether the toner adheres to the surface of the photoreceptor was examined by the following method.
As shown in FIG. 19A, a belt image having a belt-like image portion and a non-image portion is input in the axial direction of the photosensitive member, and the surface of the photosensitive member of toner in the belt portion where the toner is input on the photosensitive member An experiment was conducted to compare the fixed state of each.

The band image portion is a solid image, and an experiment was conducted under the condition that the base component of the toner easily adheres to the photoconductor by supplying a large amount of toner onto the photoconductor surface at one time. Specifically, 5000 belt images were input continuously, and the presence / absence of adhesion of the toner component to the surface of the photoreceptor and the presence / absence of an abnormal image due to white spots were compared. As a result, the photosensitive member 2 and the photosensitive member 4 having a Martens hardness of 190 N / mm ² or more did not cause the toner component to adhere to the surface of the photosensitive member, and abnormal images due to white spots were not generated. On the other hand, in the photoconductors 1, 3, and 5, the toner component was fixed on the surface of the photoconductor, and abnormal images were observed due to white spots.

<Verification experiment 2: Experiment 2 for confirming the presence or absence of white spots>
In the above-mentioned experiment 1 for confirming whether or not white spots have occurred, in order to accelerate whether or not the toner base component is fixed to the photosensitive member, the toner input to the surface of the photosensitive member is accelerated as shown in FIG. Experiments were performed using such band images. However, white spots are caused not only by the fixing of the toner base but also by the fact that silica as a toner additive adheres to the surface of the photoreceptor. Therefore, for the purpose of verifying the occurrence of white spots due to the fixing of the toner additive, Experiment 2 for confirming the occurrence of white spots was performed. Specifically, as shown in FIG. 19B, 3000 blank sheets were continuously input, and the presence / absence of adhesion of the toner additive to the surface of the photoreceptor was compared with the presence / absence of an abnormal image due to white spots.

  When the blank paper is continuously input, the toner is agitated in the developing machine, but the toner is not developed on the photoconductor and remains in the developing machine without being consumed. It becomes easy to detach from the toner base material. The released toner additive tends to move from the developing roller onto the photoreceptor. Therefore, by continuously inputting the blank paper image, it is possible to conduct an experiment under a condition where the toner additive component is easily fixed to the photoreceptor.

  Also in this verification experiment 2, the photosensitive member 2 and the photosensitive member 4 did not cause the toner additive to adhere to the surface of the photosensitive member, and there was no occurrence of abnormal images due to white spots. On the other hand, in the photoconductors 1, 3 and 5, the toner additive was fixed on the surface of the photoconductor, and abnormal images were observed due to white spots.

<Verification Experiment 3: Photoconductor Wear Speed and Elastic Power>
Next, using the photoconductors 2, 3, and 4, the relationship between the elastic power and the photoconductor wear speed was examined. Specifically, as shown in FIG. 19C, a solid image is formed in half of the photosensitive member axis direction, and 10,000 images are formed in which the other half is a non-image portion, and a band image portion and a non-image portion are formed. The amount of abrasion of the photoconductor was measured. It has been found that the wear speed of the photoreceptor varies depending on the difference in image area ratio. In particular, when the image area ratio in the photoconductor axis direction varies greatly between repeated image outputs, the photoconductor wear amount in the photoconductor axis direction varies, resulting in wear unevenness, image density unevenness, and an abnormal image. As for the image input, three sheets were continuously output, the photosensitive member was stopped once, the three sheets were continuously output, and the operation of once stopping the photosensitive member was repeated. As a result, the photoreceptor wear amount was as follows. Further, as an example, when the number of output of the photosensitive member is 10,000, the number of sheets that can be output by the image output apparatus in which the photosensitive member traveling distance is about 7 km is estimated and written together. At this time, the allowable cutting amount that does not cause an abnormal image due to film cutting is set to 5 μm.

(Photoreceptor 2)
Elastic power: 36.6%
10,000 wear amount:
・ Band image part = 0.25μm / km
・ Non-image area = 0.14 μm / km
Outputtable number:
Band image part = (5 μm / 0.25 μm / km) × (10000 sheets / 7 km) = 28571 sheetsNon-image part = 5 / 0.14 × 10000/7 = 51020 sheets Difference in wear amount = (0.14 μm /Km/0.25 μm / km) × 100 = 56%

(Photoreceptor 3)
Elastic power: 37.1%
10,000 wear amount:
・ Band image part = 0.22μm / km
・ Non-image area = 0.13 μm / km
Outputtable number:
・ Band image part = 34013 sheets ・ Non-image part = 54945 sheets Difference in wear amount = 63%

(Photoreceptor 4)
Elastic power: 37.5%
10,000 wear amount:
・ Band image part = 0.18μm / km
・ Non-image area = 0.12 μm / km
Outputtable number:
・ Band image part = 39682 sheets ・ Non-image part = 59523 sheets Difference in wear amount = 67%

  As described above, it can be seen that as the elastic power increases, the wear amount of the photoconductor decreases particularly in the band image portion where the photoconductor scraping amount by the toner increases. It can also be seen that as the elastic power increases, the difference in the photoreceptor wear amount between the belt image portion and the non-image portion decreases. For the photoconductor 3 and the photoconductor 4 having an elastic power of over 37%, the difference in the amount of wear can be set to 60% or more, and the problem of wear unevenness can be satisfactorily suppressed.

Next, a modified example of the image forming apparatus will be described.
In the image forming apparatus shown in FIG. 1, the bias applied to the charging roller 41 of each of the process cartridges 121Y, 121M, 121C, and 121K is set to DC, but the DC voltage is applied to the DC roller as the bias applied to the charging roller 41. By superimposing the voltage, contamination of the charging roller 41 can be suppressed. Thereby, as compared with the case where only the DC voltage is applied to the charging roller 41, there is an advantage that charging failure due to contamination of the charging roller 41 can be suppressed and the life of the process cartridge 121 can be extended.

  However, when the charging roller 41 is configured to apply a bias in which an AC voltage is superimposed on a DC voltage, a charging sound is generated. In addition, when the AC voltage is applied while the contact charging method has a small ozone generation amount, the charging current increases, so that the ozone generation amount increases compared to the case where only the DC voltage is applied. For this reason, when an AC voltage is applied to the charging roller 41 of each of the Y, M, C, and K image forming units 121, the charging sound increases during full-color image formation with four colors simultaneously, and abnormal noise and There is a case. Furthermore, the amount of ozone generation increases during four-color imaging. Therefore, it is necessary to add a soundproofing member 201 as shown in FIG. 15 as a countermeasure against abnormal noise as described above, or to add an ozone treatment system such as an ozone filter as a countermeasure against ozone, which increases the size and weight of the machine. It will become.

  Therefore, in the image forming apparatus according to the modified example, in a general office environment in which a monochrome image is output more than a color image, the Y, M, and C color processes are used less frequently than the K color process cartridge. Only the DC voltage may be applied to the charging rollers 41 of the cartridges 121Y, M, and C, and the AC voltage may be applied to the charging roller 41 of the K process cartridge 121K.

  With this configuration, even when full-color image formation is performed simultaneously for four colors, the charging sound due to the application of AC voltage is only in the black image forming unit, and the same level of charging sound as in monochrome mode is generated. A member etc. become unnecessary. Furthermore, the amount of ozone generated is at the same level as in monochrome mode, and it is not necessary to perform ozone treatment with an ozone filter or the like, and it is not necessary to add an ozone treatment system member. Therefore, the size and weight of the machine can be reduced.

  Further, the replacement cycle of the K process cartridge 121 can be made closer to the replacement cycle of the Y, M, and C process cartridges 121Y, M, and C. As a result, it is possible to improve the inconvenience such as calling a serviceman many times to replace only the K color process cartridge.

  Also, as shown in FIGS. 16 and 17, the lubricant applying device 70K may be provided only for the K color process cartridge. By using the lubricant applying device 70K, it is possible to protect the surface of the photosensitive member from the attacking action caused by the alternating current of the charging roller 41K, and to suppress the life reduction of the K-color process cartridge 121K.

  As shown in FIG. 17, the K-color process cartridge 212K includes a solid lubricant 73K, a lubricant pressure spring 72K, and the like, and uses a fur brush 71K as an application brush for applying the solid lubricant 73 onto the photoconductor 10. ing. The solid lubricant 73K is held by the bracket 75K and is pressed toward the fur brush 71K by the lubricant pressurizing spring 72K. Then, the solid lubricant 73K is scraped by the fur brush 71K that rotates in the counter direction with respect to the rotation direction of the photoconductor 10, and the lubricant is applied onto the photoconductor 10K. Lubricant scraped from the solid lubricant 73K by the fur brush roller 71K and adhered to the surface of the photoreceptor 10 in powder form is a fixed pressure type leveling blade supported so as to contact the surface of the photoreceptor 10K. 74K leveles on the photoreceptor 10K.

  The solid lubricant 73K contains a fatty acid metal salt (A) and an inorganic lubricant (B). The fatty acid metal salt is prevented from being destroyed by the charging current, and the surface of the photoconductor is prevented. At the same time, the inorganic lubricant that is not destroyed by the charging current provides a lubricating action (than the case where the lubricant is only the fatty acid metal salt). ) Maintained in better condition. This makes it possible to maintain the photoreceptor cleaning better.

  Examples of the fatty acid metal salt (A) include barium stearate, lead stearate, iron stearate, nickel stearate, cobalt stearate, copper stearate, strontium stearate, calcium stearate, cadmium stearate, magnesium stearate, Zinc stearate, zinc oleate, magnesium oleate, iron oleate, cobalt oleate, copper oleate, lead oleate, manganese oleate, zinc palmitate, cobalt palmitate, lead palmitate, magnesium palmitate, palmitate Aluminum, calcium palmitate, lead caprylate, lead caprate, zinc linolenate, cobalt linolenate, calcium linolenate, zinc ricinoleate, cadmium ricinoleate and mixtures thereof There, but is not limited to this. Moreover, you may mix and use these. In the present invention, among them, zinc stearate is most preferably used because it is particularly excellent in film formability on the photoreceptor 10.

  The inorganic lubricant (B) refers to an inorganic compound that cleaves and lubricates itself or causes internal slip. Specific examples include talc, mica, boron nitride, molybdenum disulfide, tungsten disulfide, kaolin, smectite, hydrotalcite compound, calcium fluoride, graphite, plate-like alumina, sericite, and synthetic mica. However, it is not limited to this. In particular, boron nitride has hexagonal mesh surfaces with tightly intermingled atoms overlapping at a wide interval, and the force acting between the layers is only the weak van der Waals force, so it is easily cleaved and lubricated. It can be preferably used.

  These inorganic lubricants may be surface-treated as necessary for the purpose of imparting hydrophobicity. In addition, by adding a lubricant component to the K color toner, it is possible to reduce the amount of photoconductor abrasion and improve the cleaning performance by stabilizing the cleaning blade edge. Zinc stearate, the above-described fatty acid metal salt (A), the inorganic lubricant (B), or both are added to the toner base as additives.

  By applying a lubricant to the surface of the K-color photoconductor using the lubricant application device 70K, it is possible to protect the surface of the photoconductor from the attacking action caused by the alternating current of the charging roller 41K. Further, it is possible to improve the photoconductor cleaning performance and transferability. In order to stabilize the lubricant application, the lubricant application device 70K is provided on the downstream side of the cleaning blade 62K with respect to the photoreceptor rotation direction. Further, the charging roller 41K faces the photoconductor 10K with a gap for the purpose of achieving high image quality and long life.

Further, the configuration of the cleaning blade 62K used for the K process cartridge 121K may be different from the configuration of the cleaning blades 62Y, M, and C used for the Y, M, and C process cartridges 121Y, M, and C.
More specifically, the cleaning blades 62Y, M, and C for Y, M, and C colors will be described with reference to FIG. 9 in which the 100% modulus value of the edge layer 622a of the elastic blade 622 is larger than the backup layer 622b. As the cleaning blade 62K for K color, an elastic blade 622 having a 100% modulus value of the edge layer 622a smaller than the backup layer 622b was used.

  The K-color process cartridge 121K is supplied with a lubricant onto the surface of the photosensitive member by the lubricant application device 70K. Therefore, compared to the color process cartridges 121Y, M, and C that do not supply the lubricant, the leading edge portion of the cleaning blade The behavior of 62c is stabilized. Therefore, in the K-color cleaning blade 62K, the modulus value of 100% of the edge layer 622a is made larger than that of the backup layer 622b, and the tip ridge line portion 62c of the elastic blade 622 does not have to be configured to be difficult to elastically deform. No abnormal wear or abnormal noise occurs.

  As shown in FIG. 13B, when the 100% modulus of the edge layer 622a is made higher than that of the backup layer 622b and the tip edge line portion of the cleaning blade 62 is made rigid, as shown in FIG. In addition, although the behavior of the tip ridge line portion is stable, the contact pressure with the photosensitive member is increased and the wear resistance is reduced.

  In the printer 100 shown in FIGS. 16 and 17, since the lubricant is applied to the surface of the K-color photoconductor 10K, compared to the Y, M, and C-color photoconductors that are not coated with the lubricant. The traveling distance of the photoconductor that reaches the end of its life becomes longer. Therefore, the elastic blade 622 in which the 100% modulus value of the edge layer 622a is higher than that of the backup layer 622b is used as the K-color cleaning blade 62K, similarly to the Y, M, and C-color cleaning blades 62Y, M, and C. In this case, the life of the cleaning blade 62K comes before the life of the photoconductor 10K. Accordingly, the K-color cleaning blade 62K has a 100% modulus of the edge layer 622a lower than that of the backup layer 622b, and suppresses an increase in the contact pressure of the cleaning blade 62 with the photoreceptor 10, thereby preventing wear. Increase sex.

  On the other hand, in the color cleaning blades 62Y, 62M, and 62C that clean the surface of the photoreceptor to which the lubricant is not applied, the leading edge line is more than the cleaning blade 62K for K color that cleans the surface of the photoreceptor to which the lubricant is applied. The behavior of the part 62c is not stable. Therefore, in the color cleaning blades 62Y, 62M, and 62C, abnormal wear and noise are generated by using the cleaning blade using the elastic blade 622 in which the 100% modulus of the edge layer 622a is higher than that of the backup layer. Can be suppressed. Further, the color photoconductors 10Y, 10M, and 10C have a lifetime at a stage where the traveling distance is shorter than that of the K-color photoconductor 10K coated with a lubricant, so that the 100% modulus of the edge layer 622a is reached. However, even if the wear resistance is lowered as compared with the K-color cleaning blade by using the elastic blade 622 that is higher than the backup layer, the life of the cleaning blade does not reach before the photoreceptor.

  Here, a urethane rubber material having a 100% modulus of 2.5 MPa or less is used for the edge layer 622a of the K-color cleaning blade 62K, and an elastic blade 622 in which materials of 3 MPa or more are combined is used as the backup layer 622b. . The thickness of the edge layer 622a was 0.5 mm, and the backup layer 622b was 1.3 mm. Alternatively, in terms of rubber hardness, an elastic blade 622 that is a combination of rubber materials of 60 to 65 degrees (JISA) for the edge layer and 70 to 75 degrees for the backup layer may be used as the elastic blade 622 of the K-color cleaning blade.

What has been described above is an example, and the present invention has a specific effect for each of the following aspects.
(Aspect 1)
The photosensitive member 10 that covers the tip ridge line portion 62c of the elastic blade 622 by covering at least the vicinity of the tip ridge line portion of the strip-shaped elastic blade 622 impregnated with the tip ridge line portion 62c with a surface layer 623 harder than the elastic blade 622, and the like. In the cleaning blade 62 that comes into contact with the surface of the member to be cleaned and removes the powder from the surface of the member to be cleaned, the elastic blade 622 is composed of a plurality of layers made of materials having 100% modulus values different from each other. Of the plurality of layers 622, the edge layer 622a that forms the tip edge line portion 62c is formed of a material having a 100% modulus value higher than that of other layers such as the backup layer 622b.
By providing such a configuration, as described in the embodiment, the behavior of the tip ridge line portion 62c can be stabilized, and abnormal wear and abnormal noise can be suppressed. In particular, even without applying a lubricant to the surface of a member to be cleaned such as the photoconductor 10, the occurrence of abnormal wear and abnormal noise can be suppressed, a lubricant application device can be eliminated, and the device can be made inexpensive. it can. In addition, the apparatus can be reduced in size.

(Aspect 2)
In the cleaning blade 62 described in the above (Aspect 1), the elastic blade 622 has the tip ridge line portion 62c impregnated with acrylic or / and methacrylic crosslinked resin, and the surface layer 623 is acrylic or / and / or It was formed with a methacrylic crosslinked resin.
By providing such a configuration, the following advantages can be obtained.
The toner removal performance is greatly improved. The wear of the cleaning blade 62 is reduced, and the cleaning performance can be maintained for a long time.
-The coefficient of friction between the cleaning blade 62 and the photosensitive member is reduced.
-The amount of photoconductor wear is reduced, and the life of the photoconductor and the life of the image forming apparatus can be extended.
Since the cleaning blade 62 does not rub the toner additive or the like against the surface of the photoreceptor, there is no occurrence of a white-out abnormal image.

(Aspect 3)
b In the cleaning blade 62 described in (Aspect 1) or (Aspect 2), the edge layer 622a of the elastic blade 622 has a 100% modulus value at 23 ° C. of 6 [MPa] or more and 12 [MPa] or less. Made of material.
By providing such a configuration, as described in the embodiment, the behavior of the tip ridge line portion 62c can be stabilized, and abnormal wear and abnormal noise can be suppressed.

(Aspect 4)
Also, latent image formation such as an image carrier such as the photosensitive member 10, a charging means such as a charging device 40 for charging the surface of the image carrier, and an exposure device 140 for forming an electrostatic latent image on the surface of the charged image carrier. And developing means such as a developing device 50 for developing the electrostatic latent image formed on the surface of the image carrier to form a toner image, and transferring the toner image on the surface of the image carrier to a transfer body such as the intermediate transfer belt 162. A printer 100 including a transfer unit such as a primary transfer roller 161 and a cleaning unit such as a cleaning device 30 having a cleaning blade 62 that contacts the surface of the image carrier and cleans transfer residual toner attached to the surface of the image carrier. In the image forming apparatus such as the above, as the cleaning blade 62, any one of the cleaning blades of (Aspect 1) to (Aspect 3) is used.
By providing such a configuration, as described in the embodiment, it is possible to suppress the generation of abnormal noise and obtain a good image over time.

(Aspect 5)
In the image forming apparatus according to (Aspect 4), the charging unit such as the charging device 40 includes a charging roller 41 that comes into contact with the surface of the image carrier such as the photoconductor 10. The unevenness | corrugation extended along was formed.
With this configuration, as described in the embodiment, the surface of the image carrier such as the photoconductor 10 can be stably charged. Further, even if fine irregularities are formed on the surface of the photosensitive member due to wear with the charging roller, the cleaning blade according to (Aspect 1) to (Aspect 3) is used, so that abnormal cleaning of the cleaning blade and generation of abnormal noise occur. Can be suppressed.

(Aspect 6)
In the image forming apparatus according to (Aspect 5), a surface treatment layer surface-treated with a surface treatment liquid containing fluorine is provided on the surface layer portion of the charging roller 41.
By providing such a configuration, as described in the embodiment, contamination of the photoconductor 10 by the charging roller 41 can be prevented in any environment.

(Aspect 7)
In the image forming apparatus according to (Aspect 5) or (Aspect 6), the ten-point average surface roughness Rz of the irregularities on the surface of the charging roller 41 is set to 20 [μm] or less.
By providing such a configuration, as described in the embodiment, the acceleration of photoconductor wear can be minimized. In addition, the discharge unevenness of the charging roller 41 is less likely to occur, the surface of the photoreceptor can be charged without unevenness, and the surface potential of the photoreceptor 10 can be stabilized even in a low temperature / low humidity environment.

(Aspect 8)
In the image forming apparatus according to any one of (Aspect 4) to (Aspect 7), the image carrier such as the photoreceptor 10 has a surface layer containing fine particles.
With this configuration, as described in the embodiment, the abrasion resistance of the surface of the photoreceptor is improved, and the cleaning performance is improved. In addition, since the fine particles are contained, an abnormal white image due to rubbing of the toner additive on the surface of the photoreceptor is prevented.

(Aspect 9)
In any of the image forming apparatuses (Aspect 4) to (Aspect 8), the image carrier such as the photoconductor 10 has a Martens hardness (HM) of 190 [N / mm ² ] or more and is elastic. The surface layer 93 has a work rate (We / Wt) of 37% or more.
With this configuration, as described in the embodiment, the abrasion resistance of the surface of the photoreceptor is improved, and the cleaning performance is improved. In addition, since the fine particles are contained, an abnormal white image due to rubbing of the toner additive on the surface of the photoreceptor is prevented.

(Aspect 10)
In the image forming apparatus according to any one of (Aspect 4) to (Aspect 9), at least an image carrier such as the photoreceptor 10, a charging unit such as the charging device 40, and a developing unit such as the developing device 50. And a cleaning means such as a cleaning device 30 and an image forming unit such as a plurality of process cartridges 121 for forming different color images, and one of the plurality of image forming units generates a black image. The black image forming unit is a black image forming unit, the charging unit of the black image forming unit applies a voltage obtained by superimposing an AC voltage on a DC voltage to a charging member such as the charging roller 41, and the charging unit of the other image forming unit includes: Only a DC voltage was applied, and a lubricant application device 70K for applying a lubricant to the surface of the image carrier was provided only in the black image forming unit.
By adopting such a configuration, as described in the embodiment, compared to the case where a voltage obtained by superimposing an AC voltage on a DC voltage is applied to the charging member of each image forming unit, abnormal noise when forming a full-color image, Ozone generation can be suppressed. In addition, as described in the embodiment, the charging member of the black image forming unit, which is frequently used in an office environment, is applied with a voltage obtained by superimposing an AC voltage on a DC voltage. And the life of the black image forming unit can be brought close to the life of the color image forming unit. As a result, even if the black image forming unit and the color image forming unit are exchanged at the same time, the image forming units for other colors are also near the end of their lives, so that waste of the image forming units for other colors can be suppressed. it can.

10: Photoconductor 30: Cleaning device 40: Charging device 41: Charging roller 41a: Core metal 41b: Conductive rubber layer 41c: Concavity and convexity 50: Developing device 62: Cleaning blade 62a: Blade tip surface 62b: Blade lower surface 62c: Tip ridge line Part 62d: Impregnation part 70K: Lubricant coating device 91: Conductive support 92: Photosensitive layer 93: Surface layer 94: Undercoat layer 121: Process cartridge 140: Exposure device 161: Primary transfer roller 162: Intermediate transfer belt 621: Holder 622: Elastic blade 622a: Edge layer 622b: Backup layer 623: Surface layer

JP 2010-152295 A Japanese Patent No. 3602898 JP 2004-233818 A JP 52-36016 A

Claims (10)

Cover at least the tip ridge line portion of the strip-shaped elastic blade impregnated in the tip ridge line with a surface layer harder than the elastic blade, and contact the surface of the member to be cleaned moving the tip ridge line part of the elastic blade. In the cleaning blade for removing powder from the surface of the member to be cleaned,
The elastic blade is constituted by a plurality of layers made of materials having mutually different 100% modulus values,
Of the plurality of layers of the elastic blade, an edge layer forming the tip edge line portion is formed of a material having a 100% modulus value higher than that of other layers. The cleaning blade of claim 1.
In the elastic blade, the tip ridge is impregnated with acrylic or / and methacrylic crosslinked resin,
A cleaning blade, wherein the surface layer is formed of acrylic or / and methacrylic crosslinked resin. The cleaning blade according to claim 1 or 2,
A cleaning blade, wherein an edge layer of the elastic blade is formed of a material having a 100% modulus value at 23 ° C. of 6 [MPa] or more and 12 [MPa] or less. An image carrier;
Charging means for charging the surface of the image carrier;
Latent image forming means for forming an electrostatic latent image on the surface of the charged image carrier;
Developing means for developing the electrostatic latent image formed on the surface of the image bearing member into a toner image;
Transfer means for transferring the toner image on the surface of the image carrier to a transfer body;
In an image forming apparatus provided with a cleaning unit having a cleaning blade that contacts the surface of the image carrier and cleans transfer residual toner attached to the surface of the image carrier.
An image forming apparatus using the cleaning blade according to claim 1 as the cleaning blade. The image forming apparatus according to claim 4.
The charging means includes a charging roller that contacts the surface of the image carrier.
An image forming apparatus, wherein unevenness extending along a circumferential direction is formed on a surface of the charging roller. The image forming apparatus according to claim 5.
An image forming apparatus, wherein a surface treatment layer surface-treated with a surface treatment liquid containing fluorine is provided on a surface layer portion of the charging roller. The image forming apparatus according to claim 5 or 6,
An image forming apparatus, wherein a ten-point average surface roughness Rz of irregularities on the surface of the charging roller is 20 [μm] or less. The image forming apparatus according to any one of claims 4 to 7,
An image forming apparatus, wherein the image carrier has a surface layer containing fine particles. The image forming apparatus according to claim 4.
The image bearing member has a surface layer having a Martens hardness (HM) of 190 [N / mm ² ] or more and an elastic work rate (We / Wt) of 37% or more. apparatus. The image forming apparatus according to any one of claims 4 to 9,
Including at least the image carrier, the charging unit, the developing unit, and a cleaning unit, and a plurality of image forming units for forming images of different colors,
Among the plurality of image forming units, one is a black image forming unit that forms a black image,
The black image forming unit charging means applies a voltage obtained by superimposing an alternating voltage on a direct current voltage to the charging member, and the other image forming unit charging means is configured to apply only the direct current voltage,
An image forming apparatus characterized in that a lubricant applying device for applying a lubricant to the surface of an image carrier is provided only in the black image forming unit.

Images