JP2008209581A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus characterized in that degrees of wear of a plurality of blades, such as a cleaning blade and application blade, which are consumable members, are recognized by counting the speed of rotation of a photoreceptor, and when the speed of rotation reaches a specified value, the reach of blade replacement is warned and displayed, thereby efficient blade replacement can be performed at an appropriate time. <P>SOLUTION: The image forming apparatus includes: the rotating photoreceptor 40; a lubricant and a brush for applying the lubricant onto the photoreceptor 40; an application blade 77 for further applying the applied lubricant onto the photoreceptor 40 finely; and a cleaning blade 75 for cleaning off toner remaining on the photoreceptor 40. After an image forming operation, the application blade 77 and the cleaning blade 75 reduce their pressures applied to the photoreceptor 40, or separate from the photoreceptor 40. In the image forming apparatus, the speed of rotation of the photoreceptor 40 can be counted. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to an image forming apparatus that forms an image by an electrostatic copying process, such as a copying machine, a facsimile machine, and a printer.
It is about.

  The multicolor image forming apparatus capable of forming a full-color image includes a direct transfer system that directly transfers a visible image on a photoconductor to a recording sheet or the like, and a photoconductor and a visible image on the photoconductor. An intermediate transfer member that is once transferred for each color is provided. In this case, a visible image is formed for each color on the photosensitive member, and the visible image is once transferred for each color on the intermediate transfer member. Transcribed. In the toner to be used, the particle size has been reduced, and various additives have been added to ensure fluidity. When such a toner is used, if the additive contained in the toner having a reduced particle size cannot be completely cleaned from the image bearing member such as the intermediate transfer member or the photosensitive member, the photosensitive member The additive filming will remain on the surface. This phenomenon causes image degradation over time. Therefore, in order to improve the cleaning ability of the cleaning blade as a cleaning member, efforts are also being made to improve the material and dimensional accuracy. Further, the lubricant is shaved with a brush and applied to the surface of the photosensitive member, and further, coating unevenness is eliminated by using an application blade to prevent filming.

On the other hand, in recent years, downsizing of the machine has been required due to the problem of the installation space of the machine, and since the size of each unit is limited, it is necessary to minimize the parts and at the same time economically, it has a long life It is also necessary to make it easier. For this reason, it is necessary to replace a component having a short lifetime without replacing a component having a long lifetime, thereby extending the lifetime of the unit and reducing the total cost.
The life of the cleaning blade or coating blade is considered to be that the tip is bent by constantly applying pressure to the photoconductor, so that the toner and additives slip through the tip, and the blade sags over time. Therefore, slipping due to insufficient pressure at the tip can be considered. That is, it can be said that the cleaning blade and the coating blade are worn by rubbing against the photosensitive member, and are therefore substantially proportional to the total number of rotations of the photosensitive member. Therefore, if the number of rotations of the photosensitive member is counted, the amount of wear of the cleaning blade and the coating blade can be known.

  However, at present, the number of sheets when an image is formed under a certain condition is regarded as the lifetime, and the lifetime is managed by the number of sheets regardless of the imaging condition. By the way, since the photosensitive member needs to be rotated by an end sequence such as pre-rotation at the time of image formation or cleaning at the end of the image formation, the number of image formation is not proportional to the rotation number of the photosensitive member. For example, when 10 images are formed one by one and when 10 images are continuously formed, 10 images are formed continuously because there are 10 pre-rotations and end sequences. The number of rotations of the photoconductor is larger than that. In other words, it is difficult to convert the amount of lubricant consumed by the number of images formed. Therefore, if the life management is performed by the number of sheets, there is a possibility that even those that can still be used are replaced, and vice versa. The amount of wear of each blade and the amount of wear that can be performed normally vary depending on the material and the applied pressure. Therefore, if measured in advance, the blade life can be grasped only by measuring the rotational speed of the photoreceptor.

Here, as disclosed in Patent Document 1, a configuration is proposed in which the cleaning unit is contacted and separated by a solenoid and the operating time is counted to determine the lifetime, and the photoconductor unit is replaced. ing. In this case, there is only one kind of pressure applied because of the contact and separation by the solenoid. In recent years, the lifespan of a photoconductor has been extended, and three times and four times as much as a cleaning blade have become commonplace. Also, since the blade itself plays a different role, the blade pressurization time, pressurization time, material, etc. are different, so the life of each part will be different, so the replacement time for each part is the first. Match to short parts. In order to extend the service life, when the function of each blade is not necessary, it is necessary to reduce the pressure abutting on the photosensitive member as much as possible to reduce wear and sag. In this case, if the pressure is weak, the wear amount is also reduced. Therefore, the more accurate wear amount can be obtained by counting the number of revolutions when the pressure is normal and when the pressure is reduced.
Further, as proposed in Patent Document 2, in order to remove foreign matter sandwiched between the tip portion and the photosensitive member, such as a cleaning blade, it is reversed without separation or reduced in pressure when no image is formed. Thus, it is possible to remove foreign matters while avoiding wear as much as possible, which leads to a longer life of the cleaning blade, but it is not possible to know an appropriate time.

JP-A-62-231271 JP 2005-62233 A

  Therefore, the present invention has been made in view of the above problems, and the problem is grasped by counting the number of rotations of the photosensitive member to determine the wear amount of a plurality of blades such as cleaning blades and coating blades that are life parts. It is an object of the present invention to provide an image forming apparatus characterized in that when a prescribed number of rotations is reached, a warning is displayed for blade replacement, so that it can be replaced efficiently at an appropriate time.

The features of the present invention, which is a means for solving the above problems, are listed below.
The image forming apparatus of the present invention includes a rotating image carrier, a brush for applying the lubricant and the lubricant to the image carrier, and an application blade for further applying the applied lubricant to the image carrier. An image forming apparatus having a cleaning member for cleaning toner remaining on the image carrier, wherein the coating blade and the cleaning member are depressurized or separated from the image carrier after the image forming operation. The number of rotations of the carrier can be counted.
In the image forming apparatus of the present invention, the two blades are further depressurized or separated at independent timings, and the respective times of depressurization or separation are counted when the image carrier is rotating. Features.
In the image forming apparatus of the present invention, the image carrier is a photosensitive member.
The image forming apparatus of the present invention further includes a charging unit for uniformly charging the photosensitive member, a unit for exposing the charged photosensitive member according to information to form a latent image, and a latent image, A developing means for developing with charged toner particles, and the charging means is a charging means for applying an AC voltage to a charging member provided in contact with the photosensitive member or in a non-contact manner with an interval of 10 to 500 μm. It is a means.
The image forming apparatus of the present invention further includes a charging unit for uniformly charging the photosensitive member, a unit for exposing the charged photosensitive member according to information to form a latent image, and a latent image, And developing means for developing with charged toner particles, wherein the charging means is a charging member brought into contact with the photoreceptor.
The image forming apparatus of the present invention is further characterized in that a toner in which a base resin is produced by a polymerization reaction or a polyaddition reaction of a monomer or a prepolymer in a liquid medium is used as toner particles.
In addition, the image forming apparatus of the present invention is a process cartridge that can be attached to and detached from the image forming apparatus main body as a unit in which a photoconductor, a lubricant, a lubricant application brush, a lubricant application blade, and a cleaning member are integrally formed. It is formed.

  In the image forming apparatus of the present invention, the number of rotations of the photosensitive member can be counted, so that the wear amount of the cleaning blade and the coating blade can be grasped, so that the parts can be replaced at an appropriate time.

  The best mode for carrying out the present invention will be described below with reference to the drawings. Note that it is easy for a person skilled in the art to make other embodiments by changing or correcting the present invention within the scope of the claims, and these changes and modifications are included in the scope of the claims. The following description is an example of the best mode of the present invention, and does not limit the scope of the claims.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an embodiment of the present invention and is a schematic diagram showing the configuration of a tandem indirect transfer type color image forming apparatus.
In the figure, reference numeral 100 is a copying machine main body, 200 is a paper feed table on which it is placed, 300 is a scanner mounted on the copying machine main body 100, and 400 is an automatic document feeder (ADF) further mounted thereon.
The copying machine main body 100 is provided with an endless belt-shaped intermediate transfer member 10 in the center. As shown in FIG. 1, in the illustrated example, it is wound around three support rollers 14, 15, and 16 so that it can be rotated and conveyed clockwise in the figure.
In this illustrated example, an intermediate transfer body cleaning device 17 that removes residual toner remaining on the intermediate transfer body 10 after image transfer is provided to the left of the second support roller 15 among the three. Further, four images of black, cyan, magenta, and yellow are formed on the intermediate transfer member 10 stretched between the first support roller 14 and the second support roller 15 among the three along the conveyance direction. The tandem image forming apparatus 20 is configured by arranging the forming units 18 side by side. An exposure device 21 is further provided on the tandem image forming apparatus 20 as shown in FIG.

On the other hand, a secondary transfer device 22 is provided on the side opposite to the tandem image forming apparatus 20 with the intermediate transfer body 10 interposed therebetween. In the illustrated example, the secondary transfer device 22 is configured by spanning a secondary transfer belt 24, which is an endless belt, between two rollers 23, and is pressed against the third support roller 16 via the intermediate transfer body 10. The image on the intermediate transfer body 10 is transferred to a sheet.
A fixing device 25 for fixing the transfer image on the sheet is provided beside the secondary transfer device 22. The fixing device 25 is configured by pressing a pressure roller 27 against a fixing belt 26 that is an endless belt.
The secondary transfer device 22 described above is also provided with a sheet transport function for transporting the image-transferred sheet to the fixing device 25. Of course, a non-contact charger may be arranged as the secondary transfer device 22, and in such a case, it is difficult to provide this sheet conveyance function together.
In the illustrated example, under such a secondary transfer device 22 and a fixing device 25, a sheet reversing device 28 for reversing the sheet so as to record images on both sides of the sheet in parallel with the tandem image forming device 20 described above. Is provided.

  Now, when making a copy using this color copying machine, a document is set on the document table 30 of the automatic document feeder 400. Alternatively, the automatic document feeder 400 is opened, a document is set on the contact glass 32 of the scanner 300, and the automatic document feeder 400 is closed and pressed by it. When a start switch (not shown) is pressed, when the document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32, and then the document is set on the other contact glass 32. At that time, the scanner 300 is immediately driven to travel the first traveling body 33 and the second traveling body 34. Then, the first traveling body 33 emits light from the light source and further reflects the reflected light from the document surface toward the second traveling body 34, and is reflected by the mirror of the second traveling body 34 and passes through the imaging lens 35. The document is placed in the reading sensor 36 and the original content is read.

When a start switch (not shown) is pressed, one of the support rollers 14, 15, and 16 is driven to rotate by a drive motor (not shown), and the other two support rollers are driven to rotate to convey the intermediate transfer member 10. To do. At the same time, the individual image forming means 18 rotates the photosensitive member 40 to form black, yellow, magenta, and cyan single-color images on each photosensitive member 40, respectively. Then, along with the conveyance of the intermediate transfer member 10, the single color images are sequentially transferred to form a composite color image on the intermediate transfer member 10.
On the other hand, when a start switch (not shown) is pressed, one of the paper feed rollers 42 of the paper feed table 200 is selectively rotated, and the sheet is fed out from one of the paper feed cassettes 44 provided in multiple stages in the paper bank 43, and the separation roller 45. Then, the sheets are separated one by one into the paper feed path 46, transported by the transport roller 47, guided to the paper feed path 48 in the copying machine main body 100, and abutted against the registration roller 49 and stopped.
Alternatively, the sheet feed roller 50 is rotated to feed out the sheets on the manual feed tray 51, separated one by one by the separation roller 52, put into the manual feed path 53, and abutted against the registration roller 49 and stopped.

Then, the registration roller 49 is rotated in synchronization with the composite color image on the intermediate transfer member 10, the sheet is fed between the intermediate transfer member 10 and the secondary transfer device 22, and transferred by the secondary transfer device 22. A color image is recorded on the sheet.
The image-transferred sheet is conveyed by the secondary transfer device 22 and sent to the fixing device 25. The fixing device 25 applies heat and pressure to fix the transferred image, and then the switching roller 55 is used to switch the discharge roller. The paper is discharged at 56 and stacked on the paper discharge tray 57. Alternatively, it is switched by the switching claw 55 and put into the sheet reversing device 28, where it is reversed and guided again to the transfer position, and an image is recorded also on the back surface, and then discharged onto the discharge tray 57 by the discharge roller 56.
On the other hand, the intermediate transfer body 10 after the image transfer is removed by the intermediate transfer body cleaning device 17 to remove residual toner remaining on the intermediate transfer body 10 after the image transfer, so that the tandem image forming apparatus 20 can prepare for another image formation.

FIG. 2 is a schematic diagram showing in detail the configuration around the photoconductor that is a part of the image forming apparatus.
Now, in the tandem image forming apparatus 20 described above, the individual image forming means 18 includes, for example, a charging device 60, a developing device 61, and a primary device around a drum-shaped photoconductor 40 as shown in FIG. The image forming apparatus includes a transfer device 62, a photoconductor cleaning device 63, a charge removal device 64, and the like. In the illustrated example, the photosensitive member 40 has a drum shape in which a photosensitive organic photosensitive material is applied to a base tube made of aluminum or the like to form a photosensitive layer. However, the photosensitive member 40 may have an endless belt shape.
Although not shown in the drawing, at least the photoconductor 40 is provided, and a process cartridge is formed by all or a part of the part constituting the image forming unit 18, and is removable from the copying machine main body 100 in a lump to improve maintenance. You may do it.

Of the portions constituting the image forming unit 18, the charging device 60 is formed in a roller shape in the illustrated example, and charges the photosensitive member 40 by applying a voltage in contact with the photosensitive member 40.
Next, the charging device 3 will be described in detail. The charging device 3 includes a charging roller as a charging member disposed to face the photosensitive drum 1. The charging roller includes, for example, a cored bar as a conductive support having a cylindrical shape, a resistance adjusting layer formed on the outer peripheral surface of the cored bar with a uniform thickness, and covering the surface of the resistance adjusting layer. And a protective layer for preventing leakage. The charging roller is connected to a power source and is applied with a predetermined voltage. The voltage may be only a direct current (DC) voltage, but is preferably a voltage obtained by superimposing an alternating current (AC) voltage on a DC voltage. By applying the AC voltage, the surface of the photoreceptor 40 can be more uniformly charged. It is preferable to superimpose the AC voltage on the DC voltage because the generation of ozone is reduced and the photosensitive member 40 can be uniformly charged. The charging roller is brought into contact with the photoreceptor 40 or is disposed with a minute gap of 10 to 500 μm. The minute gap is set by, for example, winding a spacer member having a certain thickness around the non-image forming regions at both ends of the charging roller so that the surface of the spacer member abuts on the surface of the photosensitive drum 1. Can do. As the applied bias, an AC superposition type voltage is applied, and the photosensitive member is charged by a discharge generated in a minute gap between the charging roller and the photosensitive member. Further, the charging roller may be brought into contact with the photoreceptor 40. The amount of ozone can be reduced by reducing the applied voltage.
The thickness of the photoreceptor 40 is 30 μm, the beam spot diameter of the optical system is 50 × 60 μm, and the light quantity is 0.47 mW. Further, the developing process is performed with the charging (pre-exposure) potential V ₀ of the photoreceptor 40 being −700 V, the post-exposure potential _VL being −120 V, and the developing bias voltage being −470 V, that is, the developing potential 350 V.
Next, the primary transfer device 62 is formed in a roller shape and is pressed against the photoconductor 40 with the intermediate transfer body 10 interposed therebetween. Separately, it is not limited to a roller shape, and may be a non-contact corona charger or the like.
The photoconductor cleaning device 63 is provided with a cleaning blade 75 as a cleaning member made of polyurethane rubber, for example, with its tip pressed against the photoconductor 40, and the outer periphery of the photoconductor cleaning device 63 is in contact with the photoconductor 40 to provide a conductive fur brush 76. Provided to rotate freely in the direction of the arrow.

The static eliminator 64 is a lamp, for example, and initializes the surface potential of the photoreceptor 40 by irradiating light.
Then, along with the rotation of the photosensitive member 40, the surface of the photosensitive member 40 is first uniformly charged by the charging device 60, and then the writing light L from the exposure device 21 described above is emitted from the exposure device 21 according to the reading content of the scanner 300. Irradiation forms an electrostatic latent image on the photoreceptor 40.
Thereafter, toner is attached by the developing device 61 to visualize the electrostatic latent image, and the visible image is transferred onto the intermediate transfer member 10 by the primary transfer device 62. The surface of the photoconductor 40 after the image transfer is cleaned by removing residual toner with the photoconductor cleaning device 63, and is neutralized with the static eliminator 64 to prepare for another image formation.

  In the example of FIG. 2, the image forming apparatus 18 is integrated as a process cartridge. A photoreceptor 40 as a latent image carrier, a charging module 60 as a charging means, a developing module 61 as a developing means, and a cleaning module 63 as a cleaning means can be provided as each process means. The process cartridge 18 itself can also be replaced. With the process cartridge 18 removed from the main body of the image forming apparatus 100, the photosensitive member 40, the charging module 60, the developing module 61, and the cleaning module 63 can be replaced with new modules. It is exchangeable. Each module can be handled by a serviceman and a user.

Sensor means are also provided. As sensor means, a temperature / humidity sensor 65 for detecting the temperature / humidity in the process cartridge 18, a potential sensor 66 for detecting the potential of the photosensitive member 40, and a developed toner amount on the photosensitive member 40 after development are detected. A toner density sensor 67 is provided.
The temperature / humidity sensor 65 is disposed in the process cartridge 18 and has a positive temperature characteristic, for example, platinum, tungsten, nichrome, cantal, or a negative temperature coefficient, for example, SiC (silicon carbide), TaN (nitriding) Detection is performed by a detection element such as a fine temperature sensor such as a fine wire (such as tantalum) or a thin film or a thermistor. As shown in FIG. 2, the temperature / humidity sensor 65 is disposed on the upper portion 18, but is not limited to this position as long as it is on the frame.

  The potential sensor 66 is disposed on the process cartridge frame 18 and includes a potential detection unit and a control unit. The potential sensor 66 is disposed at a distance of 1 to 3 mm from the surface of the photoconductor 40 of the object to be measured. By doing so, the surface potential of the photoreceptor 40 can be detected. As shown in FIG. 2, the potential sensor 66 is disposed between the charging module 60 and the developing module 61 on the downstream side of the laser light to be exposed, at the upper portion of 18. At this position, the potential of the photoreceptor 40 that forms a latent image that becomes a patch-like solid black portion is detected, and the detected signal is transmitted to the main body of the image forming apparatus 100 through a signal line (harness) (not shown). The magnitude of the developing bias applied by the developing module 61 is determined, and the voltage is applied by controlling the power source. The potential sensor 66 is not limited to the position, and may detect the potential of the photoconductor 40 serving as a white background portion and control the light amount and exposure time of the laser beam forming the solid black portion.

  A toner density detection sensor (hereinafter referred to as “P sensor”) 67 is disposed in the process cartridge 18 and visualizes the latent image of the solid black portion formed outside the image forming area on the photoreceptor 40 with toner. The toner adhesion amount of the solid black portion is optically detected as an image density, and the detection result is transmitted as a signal to the control unit. The P sensor 67 is composed of a light emitting element (for example, an LED) and a light receiving element (not shown), and the light receiving element captures the amount of light of the light emitting element reflected from the solid black portion to obtain the amount of toner on the photoconductor 40. The toner amount on the photosensitive member 3 is detected, and the toner concentration of the developer contained in the developing module 5 is determined from the table recorded in the control unit. This P sensor is provided on the downstream side of the developing module 61. By arranging the sensors related to the photosensitive member 40 in the cartridge frame 18 in this way, the sensor means can be effectively used without wasting expensive sensors, and each process means can be easily replaced individually. can do. In addition, each replaceable process means can be made inexpensive.

In addition, signal line harnesses (not shown) are gathered on the back side of the process cartridge 18 and connected to a connector part (not shown) provided on the back side of the process cartridge 18, and this connector part is connected to the main body connector part of the image forming apparatus 100. . A connector portion is formed on the back side of the process cartridge 18 and is connected to an electric circuit on the image forming apparatus 100 main body side. A harness extending from the above-described sensor is attached to the connector portion.
In addition to this, for example, a pre-transfer charge eliminating device 68 may be provided. The pre-transfer static elimination 68 is provided on the upstream side of the transfer area to attenuate the charge on the photoconductor 40 to facilitate transfer. Further, the pre-cleaning static eliminator 64 facilitates cleaning of residual toner that has not been transferred onto the photoreceptor 40. These light emitting diodes (LD), LEDs, electroluminescence (EL), fluorescent lamps and the like are disposed as light emitting means, and any of them can expose the photoreceptor 40 to attenuate the charge on the photoreceptor 40. . The light emitting means is preferably EL or LD, and the structure is simple, and it is more preferable to use EL. Moreover, you may provide static elimination before a charge upstream of a charging device. The residual potential of the photoconductor 40 can be erased and the photoconductor 40 can be uniformly charged.

The lubricant application brush 40 a has a large number of bristles provided on the outer periphery of the central axis extending long in the width direction of the photoreceptor 40. The tip of the lubricant application brush 40a is in contact with the surface of the photoreceptor 40 over almost the entire width. The rotating shaft extends perpendicularly to the paper surface of FIG. 2 and is rotatably supported by the front and rear side plates of the cleaning case, which is a supporting member thereof, and is driven in an appropriate direction by a driving device (not shown) and a clutch connected thereto. Driven by rotation (rotates when the clutch is ON, and does not rotate when the clutch is OFF).
In FIG. 2, the photoconductor 40 rotates in the A direction, and the lubricant application brush 40a rotates in the B direction. The rotating lubricant application brush 40a contacts the solid lubricant 40b pressurized by the spring 40c, and scrapes off the solid lubricant 40b little by little. The lubricant transferred to the lubricant application brush 40a is applied to the photoconductor 40 driven in the A direction while being in contact with the lubricant application brush 40a.

  As the solid lubricant 40b, for example, a dry solid hydrophobic lubricant is used, and typical examples thereof include zinc stearate, barium stearate, lead stearate, iron stearate, nickel stearate, cobalt stearate, stearin. Copper oxide, strontium stearate, calcium stearate, cadmium stearate, magnesium stearate, zinc oleate, manganese oleate, iron oleate, cobalt oleate, lead oleate, magnesium oleate, copper oleate, zinc palmitate, Cobalt palmitate, copper palmitate, magnesium palmitate, aluminum palmitate, calcium palmitate, lead caprylate, lead caproate, zinc linolenate, cobalt linolenate, calcium linolenate, and Such as the relatively higher fatty acids such as linolenic acid cadmium can be mentioned. Natural waxes such as carnauba wax can also be used.

Usually, the normal image forming cleaning blade 75 and the coating blade 77 apply pressure to the photosensitive member 40 with a certain amount of biting to clean the toner remaining on the photosensitive member and apply the lubricant 40b. In this state, even when the machine is not operating, each blade remains in a state of being bitten into the photoreceptor 40 (deformed state). As a result, the cleaning and coating ability is reduced.
As shown in the figure, the cleaning blade 75 for removing the toner remaining on the photoconductor 40 is rotated around the rotation center 83 by the pressure spring 84 together with the cleaning cam contact / separation bracket 78 and is pressed against the photoconductor 40. ing. The lubricant applied to the photoreceptor by the lubricant application brush 40a is further uniformly applied to the photoreceptor 40 by the application blade 77.
The coating blade 77 is integrated with the lubricant 40 b and the coating blade cam contact / separation bracket 79, and rotates around the rotation center 83. In the figure, when no external force is applied, it rotates to the right by its own weight.

The cleaning blade cam contact / separation bracket 78 and the application blade cam contact / separation bracket 79 are moved up and down by the rotation of the cams 80 and 81, respectively. The cam is connected to a motor (not shown) of the main body, and the cams 80 and 81 are rotated by the rotation of the motor.
FIG. 3 is a schematic view showing the configuration of each cam corresponding to the cleaning blade cam contact / separation bracket and the application blade cam contact / separation bracket. In FIG. 2, the cams 80 and 81 are integrated, but when viewed from the side, the cams 80 and 81 are as shown in FIG. 3, so that the cams 80 and 81 and the contact / separation members do not interfere with each other. Although integrated, this may have separate drives with separate cams. By integrating, the drive space can be reduced and the cost can be reduced because it can be done with one drive.

  For example, since the cleaning blade 75 is pulled by the spring 84 at the time of image formation, it pressurizes the photoreceptor 40. At this time, the cam 80 for the cleaning blade 75 is on the bottom dead center side and is not in contact with the cleaning cam contact / separation bracket 78. When the cam 80 rotates and comes to the top dead center, the cleaning cam contact / separation bracket 78 is lifted by the cam 80, and the cleaning blade 75 is depressurized or separated from the photosensitive member 40.

FIG. 4 is a schematic view showing a mechanism for pressurizing and depressurizing the cleaning blade and the coating blade.
Since the lubricant application blade 77 is integrated with the lubricant 40b and the application blade contact / separation cam bracket 79 and rotates to the right side by its own weight, the cam 81 is at the top dead center during image formation, and the lubricant application blade 77 is When the pressure is applied and the image is not formed, the lubricant application blade 77 is at the bottom dead center side, and the lubricant application blade 77 is depressurized or separated.
FIG. 5 is a schematic view showing a mechanism for pressurizing and depressurizing the cleaning blade and the coating blade, respectively. Further, by changing the shape of the cam, the timing of pressurization and depressurization can be shifted so that when one of them is pressurized, the other is depressurized or vice versa. For example, as in the initial state, no image is formed, but if only the lubricant is to be applied, the coating blade is pressurized. If the cleaning blade does not require pressure, the cam shape is set as shown in FIG. The contact / separation timing can be shifted by controlling the rotation angle.

FIG. 6 is a flowchart showing the flow of blade replacement in the image forming apparatus of the present invention.
First, the image forming apparatus is started. Alternatively, after the cleaning blade 75 and the coating blade 77 are replaced, the operation is restarted.
Next, the total number of revolutions MX of the photoconductor 40 that rotates during normal image formation is stored (step S1). At that time, the amount of wear of the cleaning blade 75 and the coating blade 77 is confirmed from the total number of revolutions MX of the photoreceptor 40 (step S2). This can be achieved by incorporating a wear amount table for the photoreceptor 40 during normal image formation.
Further, when the cleaning blade 75 and the coating blade 77 are depressurized or separated from the photoconductor, the wear amount of each blade is reduced when the photoconductor 40 is rotated. RX is stored as the total number of revolutions (step S3). Then, the amount of wear of the cleaning blade 75 and the coating blade 77 per rotation number during normal rotation and reduced pressure rotation of the photoconductor 40 is confirmed (step S4).
Thus, the sum BX of the wear amount BmX at the time of normal rotation MX and the wear amount BrX at the rotation speed RX at the time of pressure reduction is confirmed (step S5). When it becomes larger than the predetermined limit wear amount B1 (step S6), a blade replacement display is displayed on the operation unit (step S7). If B1 is less than the total wear amount BX, the image forming operation is continued. The value of B1 may be a value with a margin in order to display the near end state.

  In the case where the cleaning blade 75 and the coating blade 77 are moved separately from each other, BrX is calculated for each blade to obtain BX. Further, even when the amount of wear of the blade itself is different, it is necessary to obtain the respective BrX. Thus, the amount of wear of the blade can be ascertained from the number of rotations of the photoreceptor 40, so that the cleaning blade 75 and the coating blade 77 can be replaced at an appropriate time.

  Further, the toner used in the image forming apparatus of the present invention uses, as toner particles, a toner in which a base resin is produced by a polymerization reaction or a polyaddition reaction of a monomer or a prepolymer in a liquid medium. In particular, a toner composition in which a polymer having a site capable of reacting with a compound having an active hydrogen group, polyester, and a colorant is dispersed in an organic solvent is dispersed in an aqueous medium to extend and / or crosslink. Those to be made are preferable. Below, the constituent material and manufacturing method of the toner will be described. Here, the constituent material and production example of the toner by the wet polymerization method will be described, but the toner of the present invention may be a dry melt kneading method.

(Modified polyester)
There are bonding groups other than ester groups and functional groups contained in acid and alcohol monomer units in the polyester resin, and resin components with different configurations are bonded in the polyester resin through covalent bonds, ionic bonds, etc. Indicates a state.
For example, the polyester terminal is reacted with something other than an ester bond. Specifically, a functional group such as an isocyanate group that reacts with an acid group or a hydroxyl group is introduced into the terminal and further reacted with an active hydrogen compound to modify or extend the terminal. Further, compounds having a plurality of active hydrogen groups include those in which polyester ends are bonded to each other (urea-modified polyester, urethane-modified polyester, etc.). In addition, a reactive group such as a double bond is introduced into the polyester main chain, radical polymerization is caused therefrom, and a carbon-carbon bond graft component is introduced into the side chain or the double bonds are bridged. Included (styrene modified, acrylic modified polyester, etc.).
In addition, a resin component having a different structure is copolymerized in the polyester main chain or reacted with a terminal carboxyl group or hydroxyl group. For example, those having a terminal copolymerized with a silicone resin modified with a carboxyl group, a hydroxyl group, an epoxy group, or a mercapto group are included (silicone-modified polyester and the like).

(Synthesis example of modified polyester)
Into a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 724 parts of bisphenol A ethylene oxide 2-mole adduct, 200 parts of isophthalic acid and 70 parts of fumaric acid, and 2 parts of dibutyltin oxide are added. The mixture was reacted at 230 ° C. for 8 hours and further reacted at a reduced pressure of 10 to 15 mmHg for 5 hours, then cooled to 160 ° C., 32 parts of phthalic anhydride was added thereto and reacted for 2 hours. Next, the mixture was cooled to 80 ° C., 200 parts of styrene, 1 part of benzoyl peroxide and 0.5 part of dimethylaniline were added in ethyl acetate and reacted for 2 hours. The ethyl acetate was distilled off, and the weight average molecular weight was 92,000. Polystyrene graft-modified polyester (1) was obtained.
Examples of the urea-modified polyester (i) include a reaction product of a polyester prepolymer (A) having an isocyanate group and an amine (B). As the polyester prepolymer (A) having an isocyanate group, a polycondensate of a polyol (1) and a polycarboxylic acid (2) and a polyester having an active hydrogen group are further added to the polyisocyanate (3). Examples include reacted products. Examples of the active hydrogen group possessed by the polyester include a hydroxyl group (an alcoholic hydroxyl group and a phenolic hydroxyl group), an amino group, a carboxyl group, and a mercapto group. Among these, an alcoholic hydroxyl group is preferable. is there.

  Examples of the polyol (1) include diol (1-1) and trivalent or higher polyol (1-2). (1-1) alone or (1-1) and a small amount The mixture of (1-2) is preferable. Diol (1-1) includes 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 alicyclic diol; Examples include adducts of alkylene oxides (ethylene oxide, propylene oxide, butylene oxide, etc.). Of these, preferred are alkylene oxide adducts of alkylene glycols and bisphenols having 2 to 12 carbon atoms, and particularly preferred are alkylene oxide adducts of bisphenols and those having 2 carbon atoms. It is combined use with ˜12 alkylene glycol. The trivalent or higher polyol (1-2) includes 3 to 8 or higher polyvalent aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol. Trihydric or higher phenols (trisphenol PA, phenol novolak, cresol novolak, etc.); alkylene oxide adducts of the above trivalent or higher polyphenols.

Examples of the polycarboxylic acid (2) include dicarboxylic acid (2-1) and trivalent or higher polycarboxylic acid (2-2). (2-1) alone and (2-1) with a small amount of ( The mixture of 2-2) is preferred. Dicarboxylic acids (2-1) 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, naphthalenedicarboxylic acid, etc.). 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 polycarboxylic acid (2-2) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (trimellitic acid, pyromellitic acid, and the like). The polycarboxylic acid (2) may be reacted with the polyol (1) using an acid anhydride or a lower alkyl ester (methyl ester, ethyl ester, isopropyl ester, etc.) described above.
The ratio of the polyol (1) to the polycarboxylic acid (2) is usually 2/1 to 1/1, preferably as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. 1.5 / 1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.
Examples of the polyisocyanate (3) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethyl caproate, etc.); alicyclic polyisocyanates -Toro (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.); Aromatic diisocyanate (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); Aro-aliphatic diisocyanate (α , Α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanurates; those polyisocyanates blocked with phenol derivatives, oximes, caprolactams, etc .; and two or more of these Combined use is mentioned.

  The ratio of the polyisocyanate (3) is usually 5/1 to 1/1, as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group, preferably Is 4/1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. If the molar ratio of [NCO] is less than 1, the urea content in the modified polyester will be low, and the hot offset resistance will deteriorate. The content of the polyisocyanate (3) component in the prepolymer (A) having an isocyanate group at the terminal is usually 0.5 to 40% by weight, preferably 1 to 30% by weight, more preferably 2 to 2%. 20% by weight. If it is less than 0.5% by weight, 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% by weight, the low-temperature fixability deteriorates.

The number of isocyanate groups contained per molecule in the prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to average. 2.5 pieces. If it is less than 1 per molecule, the molecular weight of the modified polyester will be low, and the hot offset resistance will deteriorate.
As amines (B), diamine (B1), triamine or higher polyamine (B2), amino alcohol (B3), amino mercaptan (B4), amino acid (B5), and amino groups of B1 to B5 are blocked. (B6) and the like. Examples of the diamine (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′dimethyldicyclohexylmethane, diaminecyclohexane, Isophorone diamine etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine etc.) and the like. Examples of the trivalent or higher polyamine (B2) include diethylenetriamine and triethylenetetramine. Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid. Examples of the B1 to B5 amino group blocked (B6) include ketimine compounds and oxazoline compounds obtained from the B1 to B5 amines 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.

Furthermore, if necessary, the molecular weight of the modified polyester can be adjusted using an elongation terminator. Examples of the elongation terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).
The ratio of the amines (B) is equivalent to the equivalent ratio [NCO] / isocyanate group [NCO] in the prepolymer (A) having an isocyanate group to the amino group [NHx] in the amines (B). [NHx] 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] exceeds 2 or less than 1/2, the molecular weight of the urea-modified polyester (i) becomes low, and the hot offset resistance deteriorates. In the present invention, the modified polyester (i) may contain a urethane bond as well as 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 main peak molecular weight of the modified polyester of the present invention is usually 1000 to 10000, preferably 2000 to 8000. When the amount of the component having a molecular weight of less than 1000 is increased, the heat resistant storage stability tends to be deteriorated, and when the component having a molecular weight of 10,000 or more is increased, the low-temperature fixability tends to be decreased. . Further, the content of a polymer component having a molecular weight of 30000 or more is 1% to 10%, and preferably 3 to 6%, although it varies depending on the toner material. If it is less than 1%, sufficient hot offset resistance cannot be obtained, and if it is 10% or more, the gloss and transparency are deteriorated.
Moreover, it leads to hot offset improvement by using the polyester resin which contains 1-25% of THF insolubles. In addition, the toner is further pulverized by contact stress caused by a developing roller, a toner supply roller, a layer thickness regulating blade, a frictional charging blade, and the like due to long-term stirring inside the one-component developing device. This is effective for problems such as generation of ultrafine particles and deterioration of image quality due to the fluidizing agent embedded in the toner surface. Although THF-insoluble matter is effective for hot offset in color toner, it is negative for gloss and transparency of OHP, but it is effective within 1 to 10% for widening the mold release width. There is also a case that demonstrates.

(Unmodified polyester)
In the present invention, not only the modified polyester (i) can be used alone, but also the polyester (ii) not modified can be contained as a toner-binder component together with the (i). By using (ii) in combination, the low-temperature fixability and glossiness when used in a full color apparatus are improved, which is preferable to single use. Examples of (ii) include the same polycondensates of polyol (1) and polycarboxylic acid (2) as in the polyester component (i) above, and preferred ones are also the same as (i). Further, (ii) is not limited to unmodified polyester, but may be modified with, for example, a urea bond or a urethane bond. It is preferable that (i) and (ii) are at least partially compatible with each other in terms of low-temperature fixability and hot offset resistance. Accordingly, the polyester component (i) and (ii) preferably have similar compositions. When (ii) is contained, the weight ratio of (i) and (ii) is usually 5/95 to 80/20, preferably 5/95 to 30/70, more preferably 5/95 to 25/75, Particularly preferred is 7/93 to 20/80. If the weight ratio of (i) is less than 5%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.
The peak molecular weight of (ii) is usually 1000-20000, preferably 1500-10000, more preferably 2000-8000. If it is less than 1000, heat-resistant storage stability will deteriorate, and if it exceeds 10,000, low-temperature fixability will deteriorate. The hydroxyl value of (ii) is preferably 5 or more, more preferably 10 to 120, and particularly preferably 20 to 80. If it is less than 5, it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. The acid value of (ii) is preferably 10-30. By giving an acid value, it tends to be negatively charged, and the fixability tends to be further improved. However, when the acid value exceeds 30, particularly when used in a high temperature and high humidity environment, the toner charge amount may decrease, and problems such as background smearing on the image may occur.

  In the present invention, the glass transition point (Tg) of (ii) is 35 to 55 ° C, preferably 40 to 55 ° C. If it is less than 35, the heat resistant storage stability of the toner deteriorates, and if it exceeds 55 ° C., the low-temperature fixability becomes insufficient. Due to the coexistence of the modified polyester resin, the dry toner of the present invention tends to have good heat-resistant storage stability even when the glass transition point is low, as compared with known polyester toners. As the storage elastic modulus of the toner binder, the temperature (TG ′) at which 10000 dyne / cm 2 is obtained at a measurement frequency of 20 Hz is usually 100 ° C. or higher, preferably 110 to 200 ° C. If it is less than 100 ° C., the resistance to hot offset deteriorates. As the viscosity of the toner binder, the temperature (Tη) at 1000 poise at a measurement frequency of 20 Hz is usually 180 ° C. or less, preferably 90 to 160 ° C. If it exceeds 180 ° C., the low-temperature fixability deteriorates. That is, TG ′ is preferably higher than Tη from the viewpoint of achieving both low temperature fixability and hot offset resistance. In other words, the difference between TG ′ and Tη (TG′−Tη) is preferably 0 ° C. or more. More preferably, it is 10 degreeC or more, Most preferably, it is 20 degreeC or more. The upper limit of the difference is not particularly limited. Further, from the viewpoint of achieving both heat-resistant storage stability and low-temperature fixability, the difference between Tη and Tg is preferably 0 to 100 ° C. More preferably, it is 10-90 degreeC, Most preferably, it is 20-80 degreeC.

(External additive)
As the external additive, inorganic fine particles can be preferably used. The primary particle diameter of the inorganic fine particles is preferably 5 mμ to 2 μm, and particularly preferably 5 mμ to 500 mμ. Moreover, it is preferable that the specific surface area by BET method is 20-500 m <2> / g. The proportion of the inorganic fine particles used is preferably 0.01 to 5% by weight of the toner, and particularly preferably 0.01 to 2.0% by weight. 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.
In addition, polymer fine particles, such as polystyrene obtained by soap-free emulsion polymerization, suspension polymerization, and dispersion polymerization, methacrylate esters, acrylate copolymers, polycondensation systems such as silicone, benzoguanamine, and nylon, thermosetting Examples thereof include polymer particles made of a resin.
Such external additives can be surface treated to increase hydrophobicity and prevent deterioration of flow characteristics and charging characteristics even under high humidity. For example, silane coupling agents, silylating agents, silane coupling agents having an alkyl fluoride group, organic titanate coupling agents, aluminum coupling agents, silicone oils, modified silicone oils and the like are preferable surface treatment agents. .
Further, as a cleaning property improver for removing the developer after transfer remaining on the photosensitive member or the primary transfer medium, for example, fatty acid metal salts such as zinc stearate and calcium stearate, such as polymethyl methacrylate fine particles, polystyrene fine particles, etc. Examples thereof include fine polymer particles produced by soap-free emulsion polymerization. The polymer fine particles preferably have a relatively narrow particle size distribution and a volume average particle size of 0.01 to 1 μm.

(Coloring agent)
As the coloring agent of the present invention, all known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphtho-louero-S, Hansaero (10G, 5G, G), cadmium yellow -Yellow iron oxide, ocher, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanentoiero -(NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Lead Red, Lead Zhu, Kad Miu Mured, Cadmium mar-Curi red, Antimony vermilion, Permanent red 4R, Para red, Faucet red, Parachlorol Nitroaniline Red, Resource Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B , Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bold-5B, Toluidine Marun, Permanent Bold-F2K, Heliobold-BL, Bold- 10B, Bonmarine Light, Bonmarum Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone , Polyazo red, chrome bar million, benzidine orange, perinone orange, oil orange, cobalt blue, cerulean blue, alkaline bull lake, peak cock bull lake, victoria bull lake , Metal-free phthalocyanine bull, phthalocyanine bull, fast sky bull, indense rumble (RS, BC), indigo, ultramarine blue, bitumen, anthraquinone bull, 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, naphtho green B, green gold, acid green -Key, Malachite Green Lake Phthalocyanine 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 used in the present invention can also be used as a master batch combined with a resin. The binder resin to be kneaded together with the production of the master batch or the master batch includes styrene such as polystyrene, poly p-chlorostyrene, polyvinyltoluene, and its substitutes in addition to the modified and unmodified polyester resins mentioned above. Polymer: Styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate Copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene -Α-chloromethyl methacrylate copolymer, Tylene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-malein Styrenic copolymers such as acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, Examples include polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, and paraffin wax. Can be used alone or in combination The
In this master batch, a master batch can be obtained by mixing and kneading a resin for a master batch and a colorant under a high shearing force. At this time, an organic solvent can be used to enhance the interaction between the colorant and the resin. In addition, the so-called flushing method is a method of mixing and kneading an aqueous paste containing water of a colorant together with a resin and an organic solvent, transferring the colorant to the resin side, and removing moisture and organic solvent components. -Since it can be used as it is, it does not need to be dried and is preferably used. For mixing and kneading, a high shear dispersion device such as a three-roll mill is preferably used.

The dry toner of the present invention can be produced by the following method, but is not limited thereto.
(Manufacturing method of toner in aqueous medium)
As an aqueous medium used in the present invention, water alone may be used, but a solvent miscible with water may be used in combination. Examples of miscible solvents include alcohol (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (e.g., methyl cellosolve), lower ketones (e.g., acetone, methyl ethyl ketone), etc. Is mentioned.
As a method for stably forming a dispersion composed of the prepolymer (A) and the unmodified polyester (ii) in the aqueous medium, the prepolymer (A) and the unmodified polyester (ii) are formed in the aqueous medium. Examples thereof include a method of adding a toner raw material composition and dispersing it by shearing force. The prepolymer (A), unmodified polyester (ii) and other toner compositions (hereinafter referred to as toner raw materials) colorants, colorant master batches, mold release agents, charge control agents, Although mixing may be performed when forming the dispersion in the medium, it is more preferable to mix the toner raw material in advance and then add and disperse the mixture in the aqueous medium. In the present invention, other toner raw materials such as a colorant, a release agent, and a charge control agent do not necessarily have to be mixed when forming particles in an aqueous medium. It may be added later. For example, after forming particles containing no colorant, the colorant can be added by a known dyeing method.

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. In order to make the particle size of the dispersion 2 to 20 μm, a high-speed shearing type 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. Higher temperatures are preferred in that the dispersion of the modified polyester (i) or the prepolymer (A) has a low viscosity and is easily dispersed.
The amount of the aqueous medium used is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight based on 100 parts of the toner composition containing the prepolymer (A) and the unmodified polyester (ii). If the amount is less than 50 parts by weight, the toner composition is not well dispersed, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 20000 parts by weight, it is not economical. Moreover, a dispersing agent can also be used with resin fine particles as needed. The use of a dispersant is preferred in that the particle size distribution is sharp and the dispersion is stable.
The step of synthesizing the urea-modified polyester from the prepolymer (A) may be carried out by adding amines (B) before dispersing the toner composition in the aqueous medium, or after dispersing in the aqueous medium. A reaction may be caused from the particle interface by adding the compound (B). In this case, urea-modified polyester is preferentially produced on the surface of the manufactured toner, and a concentration gradient can be provided inside the particles.

  As an dispersant for emulsifying and dispersing the oily phase in which the toner composition is dispersed in a liquid containing water, anionic surface active soot such as alkylbenzene sulfonate, α-olefin sulfonate, and phosphate ester, alkyl Amine salt types such as amine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, imidazoline, alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, pyridinium salts, alkylisoquinolinium salts, chlorides Quaternary ammonium salt type cationic surfactants such as benzethonium, nonionic surfactants such as fatty acid amide derivatives and polyhydric alcohol derivatives such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine And N-alkyl N, amphoteric surfactants such as N- dimethyl ammonium betaine and the like.

Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount. Preferred examples of the anionic surfactant having a fluoroalkyl group include a fluoroalkylcarboxylic acid having 2 to 10 carbon atoms and a metal salt thereof, disodium perfluorooctanesulfonylglutamate, 31- [omega-fluoroalkyl (C6 -C11) oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [omega-fluoroalkanoyl (C6-C8) mono-N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) ) Carboxylic acid and metal salt, perfluoroalkylcarboxylic acid (C7 to C13) and its metal salt, perfluoroalkyl (C4 to C12) sulfonic acid and its metal salt, perfluorooctanesulfonic acid diethylanolamide N-propyl-N- (2hydroxyethyl) -Fluorooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, mono-fluoroalkyl (C6-C16) ethyl phosphoric acid Examples include esters.
As product names, Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florad FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS 1-101, DS-102 (manufactured by Taikin Kogyo Co., Ltd.), Mega-Fac F-l10, F-120, F-113, F-191, F-812, F-833 (manufactured by Dainippon Ink, Inc.), Ektop EF-1 102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), Phgent F-100, F150 (manufactured by Neos), etc. Can be mentioned.

  Further, as the cationic surfactant, aliphatic quaternary ammonium salts such as aliphatic primary, secondary or secondary amic acid, perfluoroalkyl (C6C10) sulfonamidopropyltrimethylammonium salt which right the fluoroalkyl group , Benzalkonium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, as trade names, Surflon S-121 (manufactured by Asahi Glass Co., Ltd.), Florad FC-135 (manufactured by Sumitomo 3M Co., Ltd.), Unidyne DS-202 (Manufactured by Daikin Industries Co., Ltd.), MegaFuck F-150, F-824 (manufactured by Dainippon Ink, Inc.), Xtop EF-132 (manufactured by Tochem Products), Phgentent F1300 (manufactured by Neos), etc. Is mentioned.

Moreover, tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, hydroxyapatite, etc. can be used as an inorganic compound dispersant which is hardly soluble in water.
Further, it is particularly preferable to stabilize the dispersed droplets with a polymer protective colloid. For example, (meth) acrylic acid containing acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride, or a hydroxyl group Monomers such as β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, γ-hydroxypropyl acrylate, γ-hydroxypropyl methacrylate, acrylic acid 3-chloro-2-hydroxypropyl, 3-chloro-2-monohydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate, N -Ethers of vinyl alcohol or vinyl alcohol, such as methylol acrylamide, N-methylol methacrylamide, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, or vinyl alcohol Esters of compounds containing a carboxyl group, for example, pinyl acetate, pinyl propionate, vinyl butyrate, acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride , Homopolymers or copolymers such as those having a nitrogen atom such as pinyl pyridine, vinyl pyrrolidone, vinyl imidazole, ethylene imine, or a heterocyclic ring thereof, polyoxyethylene, polyoxypropylene, polyethylene Oxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, poly Polyoxyethylenes such as oxyethylene nonylphenyl ester, celluloses such as methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose and the like can be used.
In addition, when an acid such as calcium phosphate salt or an alkali-soluble substance is used as the dispersion stabilizer, the calcium phosphate salt is removed from the fine particles by a method such as dissolving the calcium phosphate salt with an acid such as hydrochloric acid and then washing with water. To do. It can also be removed by operations such as enzymatic degradation.
When a dispersant is used, the dispersant can remain on the surface of the toner particles. However, it is preferable from the charged surface of the toner that the dispersant is washed away after the elongation and / or crosslinking reaction.

Further, in order to lower the viscosity of the toner composition, a solvent in which the prepolymer (A) and the unmodified polyester (ii) are soluble can be used. The use of a solvent is preferable in that the particle size distribution is sharpened. The solvent is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal. Examples of the solvent include 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 the solvent with respect to 100 parts of prepolymer (A) is 0-300 parts normally, Preferably it is 0-100 parts, More preferably, it is 25-70 parts. When a solvent is used, it is removed by heating under normal pressure or reduced pressure after the elongation and / or crosslinking reaction.
The elongation and / or crosslinking reaction time is selected depending on the reactivity depending on the combination of the isocyanate group structure of the prepolymer (A) and the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 24. It's time. The reaction temperature is usually 0 to 150 ° C, preferably 5 to 50 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.

In order to remove the organic solvent from the obtained emulsified dispersion, a method in which the temperature of the entire system is gradually raised to completely evaporate and remove the organic solvent in the droplets can be employed. Alternatively, the emulsified dispersion can be sprayed into a dry atmosphere to completely remove the water-insoluble organic solvent in the droplets to form toner fine particles, and the aqueous dispersant can be removed by evaporation. is there. As a dry atmosphere in which the emulsified dispersion is sprayed, a gas obtained by heating air, nitrogen, carbon dioxide gas, combustion gas, or the like, in particular, various air currents heated to a temperature equal to or higher than the boiling point of the highest boiling solvent used is generally used. Sufficient target quality can be obtained by short-time processing such as spray dryer, belt dryer, rotary kiln and the like.
When the particle size distribution at the time of emulsification dispersion is wide and washing and drying processes are performed while maintaining the particle size distribution, the particle size distribution can be adjusted by classifying into a desired particle size distribution.
In the classification operation, the fine particle portion can be removed in the liquid by a cyclone, a decanter, centrifugation, or the like. Of course, the classification operation may be performed after obtaining the powder as a powder after drying.
The dispersant used is preferably removed from the obtained dispersion as much as possible, but it is preferable to carry out it simultaneously with the classification operation described above.

Mix the resulting toner powder after drying with dissimilar particles such as release agent fine particles, charge control fine particles, fluidizing agent fine particles, and colorant fine particles, or give mechanical impact force to the mixed powder. By immobilizing and fusing on the surface, it is possible to prevent detachment of foreign particles from the surface of the resulting composite particle.
Specific means include a method of applying an impact force to the mixture by blades rotating at high speed, a method of injecting and accelerating the mixture in a high-speed air stream, and causing particles or composite particles to collide with an appropriate collision plate, etc. is there. As equipment, Ong mill (manufactured by Hosokawa Micron Co., Ltd.), I-type mill (manufactured by Nippon Numatic Co., Ltd.) was modified to reduce pulverization air pressure, hybridization system (manufactured by Nara Machinery Co., Ltd.), A kryptron system (manufactured by Kawasaki Heavy Industries, Ltd.), an automatic mortar, etc.

  The toner can be mixed with a magnetic carrier and used as a two-component developer. In this case, the carrier to toner content ratio in the developer is preferably 1 to 10 parts by weight of toner with respect to 100 parts by weight of carrier. As the magnetic carrier, conventionally known ones such as iron powder, ferrite powder, magnetite powder, magnetic resin carrier having a particle diameter of about 20 to 200 μm can be used. Examples of the coating material include amino resins such as urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, and epoxy resin. Polyvinyl and polyvinylidene resins such as acrylic resins, polymethyl methacrylate resins, polyacrylonitrile resins, polyvinyl acetate resins, polyvinyl alcohol resins, polyvinyl butyral resins, polystyrene resins and styrene acrylic copolymer resins, Halogenated olefin resins such as vinyl, polyester resins such as polyethylene terephthalate resin and polybutylene terephthalate resin, polycarbonate resins, polyethylene resins, polyvinyl fluoride resins, polyvinylidene fluoride resins, polytrifluoroethylene resins, polyhexafluoro Propylene resin, copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene and vinylidene fluoride and non- Monomers including a fluoro terpolymers such, and silicone resins. Moreover, you may contain electrically conductive powder etc. in coating resin as needed. As the conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide or the like can be used. These conductive powders preferably have an average particle diameter of 1 μm or less. When the average particle diameter is larger than 1 μm, it becomes difficult to control electric resistance.

  The toner of the present invention can also be used as a one-component magnetic toner that does not use a carrier or a non-magnetic toner.

  In addition, when preparing the developer, in order to improve the fluidity, storage stability, developability, and transferability of the developer, the hydrophobic silica fine particles listed above are further listed in the developer produced as described above. Inorganic fine particles such as powder may be added and mixed. For mixing external additives, a general powder mixer is used, but it is preferable to equip a jacket or the like to adjust the internal temperature. In order to change the load history applied to the external additive, the external additive may be added in the middle or gradually. Of course, you may change the rotation speed of a mixer, rolling speed, time, temperature, etc. A strong load may be given first, then a relatively weak load, or vice versa. Examples of the mixing equipment that can be used include a V-type mixer, a rocking mixer, a Ladige mixer, a Nauter mixer, a Henschel mixer, and the like.

The developing device 4 of the image forming unit 18 uses a developer containing the above toner. In the developing device 4, the developer carrying member carries and conveys the developer, and an alternating electric field is applied at a position facing the photoconductor 40 to develop the latent image on the photoconductor 40. By applying the alternating electric field, the developer is activated, the charge amount distribution of the toner can be narrowed, and the developability can be improved.
In addition, the photosensitive member 40 and the developing device are integrally supported, and the process cartridge can be formed to be detachable from the main body of the image forming apparatus. In addition, the process cartridge may include a charging unit and a cleaning unit.

1 is a schematic diagram illustrating a configuration of a color image forming apparatus of a tandem type indirect transfer system according to an embodiment of the present invention. 2 is a schematic diagram illustrating in detail a configuration around a photoconductor that is a part of the image forming apparatus. FIG. It is the schematic which shows the structure of each cam corresponding to a cleaning blade cam contact / separation bracket and a coating blade cam contact / separation bracket. It is the schematic which shows the mechanism which pressurizes and depressurizes a cleaning blade and a coating blade. It is the schematic which shows the mechanism which pressurizes and depressurizes a cleaning blade and a coating blade, respectively. 6 is a flowchart showing a flow of blade replacement in the image forming apparatus of the present invention.

Explanation of symbols

1 Charged body (photoconductor)
DESCRIPTION OF SYMBOLS 10 Intermediate transfer body 17 Intermediate transfer body cleaning device 18 Image forming means 20 Tandem image forming device 21 Exposure device 22 Secondary transfer device 24 Secondary transfer belt 25 Fixing device 35 Imaging lens 36 Read sensor 40 Photoconductor 42 Feed roller 44 Paper feed cassette 45 Separation roller 46 Paper feed path 47 Transport roller 48 Paper feed path 49 Registration roller 50 Paper feed roller 56 Paper discharge roller 57 Paper discharge tray 60 Charging device 61 Cleaning device 64 Pre-cleaning static elimination device 65 Temperature / humidity sensor 66 Potential sensor 67 Toner density detection sensor 68 Pre-transfer static eliminator 75 Cleaning blade 77 Application blade 78 Cleaning cam contact / separation bracket 79 Application blade cam contact / separation bracket 80, 81 Cam 83 Rotation center 84 Pressure spring 100 Image forming apparatus main body 200 Paper feed table 300 Scanner 400 Automatic document feeder (ADF)

Claims (7)

A rotating image carrier;
A brush for applying the lubricant and the lubricant to the image carrier;
An application blade for further applying the applied lubricant to the image carrier, and
A cleaning member for cleaning toner remaining on the image carrier,
In the image forming apparatus in which the coating blade and the cleaning member are depressurized or separated from the image carrier after the image forming operation,
The image forming apparatus is capable of counting the number of rotations of the image carrier. The image forming apparatus according to claim 1,
Two blades are depressurized or separated at independent timings,
An image forming apparatus, characterized in that each time of decompression or separation is counted during a time when the image carrier is rotating. The image forming apparatus according to claim 1, wherein
An image forming apparatus, wherein the image carrier is a photoconductor. The image forming apparatus according to claim 3.
Charging means for uniformly charging the photoreceptor;
Means for exposing a charged photoreceptor in accordance with information to form a latent image;
Developing means for developing the latent image with charged toner particles;
An image forming apparatus, wherein the charging unit is a charging unit that applies an AC voltage to a charging member that is in contact with the photosensitive member or in a non-contact manner with an interval of 10 to 500 μm. The image forming apparatus according to claim 3.
Charging means for uniformly charging the photoreceptor;
Means for exposing a charged photoreceptor in accordance with information to form a latent image;
Developing means for developing the latent image with charged toner particles;
An image forming apparatus, wherein the charging unit is a charging member brought into contact with the photosensitive member. The image forming apparatus according to claim 4 or 5,
An image forming apparatus comprising: a toner in which a base resin is produced by a polymerization reaction or a polyaddition reaction of a monomer or a prepolymer in a liquid medium as toner particles. The image forming apparatus according to claim 3.
An image forming apparatus characterized in that the photosensitive member, the lubricant, the lubricant applying brush, the lubricant applying blade, and the cleaning member are integrally formed as a process cartridge that is detachable from the main body of the image forming apparatus. .