JP5267210B2 - Cleaning device, process cartridge, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning device that includes a first rubber blade and a counter type second rubber blade at a position downstream from the first rubber blade relative to a direction of rotation of a photoconductive drum based on a transfer position on the photoconductive drum, wherein anxiety about occurrence of chipping, curling of the second rubber blade, and noise or the like is completely eliminated. <P>SOLUTION: The second rubber blade 24 is formed of the same material as the first rubber blade 17, and has the same width and thickness as those of the first rubber blade 17, and only free length that is length of the rubber blade projecting from a blade holder is formed to be longer in the second rubber blade 24 than in the first rubber blade 17. The second rubber blade 24 is attached to a cartridge case 14 via a second blade holder 23 such that a bite amount at the photoconductive drum 15 is the same, and a contact angle &theta; that is an angle formed by a tangent of the photoconductive drum 15 at a contact-side edge of a leading end with an edge surface of the leading end is between 70-90 degrees. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a cleaning device, a process cartridge, and an image forming apparatus used in an electrophotographic image forming apparatus.

For example, an upstream rubber blade (hereinafter referred to as a “first rubber blade”) that abuts on the surface of the image carrier, and an image bearing member that is attached to the rotatable image carrier that carries the toner image. And a downstream rubber blade (hereinafter referred to as “second rubber blade”) that contacts the surface of the image carrier on the downstream side in the rotation direction of the image carrier relative to the transfer position of An apparatus is known (see, for example, Patent Document 1).
This rubber blade employs a so-called counter system in which the front end portion is provided to the upstream side in the rotational direction with respect to the rear end portion in order to efficiently remove transfer residual toner, lubricant, and the like on the image carrier. .

  A closed space formed by the first rubber blade, the second rubber blade longer than the first rubber blade, and the image carrier is filled with a lubricant made of zinc stearate, A rubber blade dedicated to leveling a lubricant is known (see, for example, Patent Document 2).

  As described above, by using the rubber blade as a counter system, it is possible to efficiently remove the transfer residual toner and lubricant on the image carrier, but the transfer residual toner and lubricant on the edge of the rubber blade in contact with the image carrier. When the entry of the agent becomes extremely small, the lubricant and the transfer residual toner that made the rubber blade and the image carrier slip well are insufficient, the blade edge is chipped, the blade is turned over, abnormal noise, abnormal wear, etc. May occur.

  In this regard, the first rubber blade has no problem because the transfer residual toner remaining on the surface of the image carrier immediately after the toner image carried on the image carrier is transferred to the transfer body is not a problem. In the case of this rubber blade, since most of the transfer residual toner is scraped off by the first rubber blade, the above-described problems may occur.

  In the cleaning device of Patent Document 1, the free length, which is the amount of protrusion of the blade from the end of the blade holder that holds the rubber blade, is set to the same length for both the first rubber blade and the second rubber blade. Although it is described that the pressing force to the photosensitive drum is pressed using a spring, etc., rubber blades having the same free length and blade thickness are arranged side by side so that the tip faces downward, For example, the lubricant and transfer residual toner are positively dropped (see FIG. 2 in Patent Document 1). For example, the blade edge of the second rubber blade caused by insufficient entry of the lubricant or transfer residual toner. No consideration was given to defects such as chipping, blade turning, abnormal noise, and abnormal wear.

  In order to reduce or eliminate such a problem, the force that presses the second rubber blade against the image carrier, that is, the contact pressure (at rest) is lowered from the first rubber blade, so that the image carrier and its image carrier are reduced. It is preferable to reduce the frictional resistance with the edge of the second rubber blade that is a contact portion with the body.

  As means for lowering the contact pressure (when stationary) of the second rubber blade to the image carrier from that of the first rubber blade, the Young rubber modulus of the second rubber blade material is lowered. For example, the thickness may be reduced, or the amount of biting into the image carrier of the second rubber blade may be reduced.

When the Young's modulus of the second rubber blade material is lowered, the margin with respect to the blade mechanism is lowered as compared with the first rubber blade. In addition, the modulus (the rubber elastic body stress, for example, the 300% modulus which is the tensile stress at the time of elongation of 300%, etc.) in the case where the hardness and the amount of deformation, which are physical properties correlated with the Young's modulus, are large is also reduced. The margin for wear is reduced.
When the blade thickness of the second rubber blade is reduced, the shear stress to the blade increases, so that the permanent set increases and causes a large decrease in the stationary contact pressure due to deterioration over time.
If the amount of biting into the image carrier of the second rubber blade is reduced, it will cause a large variation in the contact pressure at rest due to the effects of component tolerances, so the conditions should be far away from the first rubber blade. It is difficult.

  Patent Document 2 discloses a second rubber blade that is longer than the first rubber blade, but in a closed space formed by the first rubber blade, the second rubber blade, and the image carrier. Filled with lubricant. Therefore, when viewed as a rubber blade for scraping off the transfer residual toner, it is substantially the same as one rubber blade, and it is said that the transfer residual toner on the image carrier is efficiently scraped at two locations. In addition, since the second rubber blade used for leveling the lubricant is in close contact with the lubricant, it is difficult to obtain sufficient elastic deformation, which may cause unevenness in the leveling of the lubricant.

  The present invention has been made in view of such a situation, and an object thereof is to provide a cleaning device, a process cartridge, and an image forming apparatus that can solve the above-described problems.

According to the first aspect of the present invention, the edge of the leading end is brought into contact with the surface of the rotatable image carrier that carries the toner image to be transferred to the transfer body, and the leading end is in contact with the rear end. A belt-shaped first rubber blade that is provided so as to be directed upstream in the rotational direction of the image carrier and whose rear end is supported by a first blade holder; and the toner image is transferred to the transfer target The edge of the tip is brought into contact with the surface of the image carrier on the downstream side of the rotation direction of the image carrier from the first rubber blade with reference to the transfer position on the image carrier. Is provided with a required space from the first rubber blade so as to be directed upstream of the rear end portion in the rotation direction of the image carrier, and the rear end portion is supported by the second blade holder. a strip-shaped second rubber blades, the first A lubricant applying means for applying a lubricant to the surface of the image carrier, and the second rubber blade and the lubricant applying means. A powder conveying screw that is rotatably provided in the region and conveys transfer residual toner and lubricant scraped off by the second rubber blade to the storage unit, and has a length of the rubber blade protruding from the blade holder. The second rubber blade has a free length longer than the free length of the first rubber blade so that the contact pressure at rest of the second rubber blade is lower than that of the first rubber blade. It is characterized by that.
According to a second aspect of the present invention, in the first aspect, a contact angle that is an angle formed between a tangent line of the image carrier and a front end surface of the front end portion at an edge of the front end portion is the first rubber blade and the first end. Each of the two rubber blades is 70 degrees or more and 90 degrees or less.
The invention according to claim 3 is characterized in that, in claim 1 or 2, the first rubber blade and the second rubber blade are made of the same material or a material having equivalent physical properties.
According to a fourth aspect of the present invention, in any one of the first to third aspects, the first rubber blade and the second rubber blade are formed to have the same width and the same thickness, and to the image carrier. The amount of biting is the same.
According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the lubricant applying means is a brush roller .
According to a sixth aspect of the present invention, there is provided a charging device comprising the cleaning device according to any one of the first to fifth aspects and the image carrier, and charging means for charging the surface of the image carrier, the image carrier. And a developing unit that develops the electrostatic latent image formed on the toner image into the toner image, and a process cartridge that is detachably integrated with the main body of the image forming apparatus .
According to a seventh aspect of the invention, there is provided an image forming apparatus including the cleaning device according to any one of the first to fifth aspects or the process cartridge according to the sixth aspect.
The invention according to claim 8 is the toner according to claim 7, wherein the toner for forming the toner image has a volume average particle diameter (Dv) in the range of 3 to 8 μm, and the volume average particle diameter (Dv) and the number average. The dispersity defined by the ratio (Dv / Dn) to the particle size (Dn) is in the range of 1.00 to 1.40 .
According to a ninth aspect of the present invention, in the seventh aspect, the toner for forming the toner image has a shape factor SF-1 in the range of 100 to 180, and the shape factor SF-2 in the range of 100 to 180. It is characterized by that.
According to a tenth aspect of the present invention, in the seventh aspect , the toner for forming the toner image is substantially spherical, and the ratio of the major axis to the minor axis (r2 / r1) is 0.5 to 1.0. In the range, the ratio of thickness to minor axis (r3 / r2) is in the range of 0.7 to 1.0, and the relationship of major axis r1 ≧ minor axis r2 ≧ thickness r3 is satisfied .

According to the present invention, the second rubber blade has a free length longer than the free length of the first rubber blade, and the stationary contact pressure of the second rubber blade is lower than that of the first rubber blade. The frictional resistance between the image carrier and the edge of the second rubber blade that is the contact portion between the image carrier and the edge is reduced without any side effects, and the blade edge is chipped, the blade is turned over, abnormal noise, or abnormal. Problems such as wear can be reduced with an extremely simple configuration.
Further, the second rubber blade also functions as a scraper for the transfer residual toner that has passed through the first rubber blade and the lubricant application means. By providing the lubricant application means away from the lubricant, the second rubber blade is provided. Since the rubber blade 2 can be sufficiently elastically deformed even when the lubricant is leveled, it is possible to avoid the possibility of unevenness in the leveling of the lubricant.

1 is a longitudinal front view schematically showing an image forming apparatus according to an embodiment. FIG. 3 is a simplified vertical front view of a process cartridge. It is an enlarged view around a rubber blade. An outline of a toner shape used in the image forming apparatus of this embodiment is shown, (a) is a schematic diagram for explaining a toner shape factor SF-1, and (b) is a toner shape factor SF-2. It is a schematic diagram. An outline of the spherical shape of a toner used in the image forming apparatus of this embodiment is shown, (a) is a schematic diagram for explaining how to define the major axis, minor axis, and thickness of the toner, and (b) is a long diagram. FIG. 4C is a schematic diagram illustrating the ratio between the axis and the minor axis, and FIG. 5C is a schematic diagram illustrating the ratio between the thickness and the minor axis.

  An embodiment of the present invention will be described. The embodiment of the present invention exemplifies an image forming apparatus provided with a cleaning device as a main part.

  As shown in FIG. 1, the image forming apparatus according to the present embodiment includes an endless intermediate transfer belt 3 that is hung on a driving roller 1 and a driven roller 2 and can rotate counterclockwise, and the intermediate transfer belt. 3, a primary transfer roller 4 provided at a predetermined interval along the inner side of the lower traveling side, and process cartridges 5Y, 5M, and 5C disposed opposite to the primary transfer roller 4 across the lower traveling side of the intermediate transfer belt 3. 5K, an exposure device 6 disposed below the process cartridges 5Y, 5M, 5C, and 5K, a paper tray 7 disposed below the exposure device 6, and a paper feed provided near the paper tray 7 A roller 8, a secondary transfer roller 9 disposed opposite to the driving roller 1 with the intermediate transfer belt 3 interposed therebetween, and a resist provided between the secondary transfer roller 9 and the sheet feeding roller 8. A toner image is generated by the fixing device 11 disposed above the roller pair 10, the driving roller 1 and the secondary transfer roller 9, a paper discharge tray portion 12 formed on the upper surface of the image forming device, and the fixing device 11. A paper discharge roller pair 13 for discharging the fixed paper to the paper discharge tray unit 12 is provided.

  As shown in FIG. 2, the process cartridges 5Y, 5M, 5C, and 5K include a cartridge case 14 and a photosensitive drum 15 as an image carrier that is provided in a substantially central position of the cartridge case 14 so as to rotate clockwise. The photoconductor drum 15 includes a cleaning device, a charging device, and a developing device, which are arranged in a clockwise direction with the topmost portion of the photosensitive drum 15 as a transfer position, and are arranged in order clockwise.

  As shown in FIG. 1, there are four process cartridges, a yellow process cartridge 5Y, a magenta process cartridge 5M, a cyan process cartridge 5C, and a black process cartridge 5K, each of which is a transfer position. The image forming apparatus main body is detachably mounted so that the top of the photosensitive drum 15 and the primary transfer roller 4 face each other with the intermediate transfer belt 3 interposed therebetween.

The cleaning device includes a first cleaning unit, a lubricant application unit, and a second cleaning unit.
The first cleaning unit is formed in a substantially L shape in a side view and is attached to the upper right part of the cartridge case 14. The front end part of the first cleaning part is in the rotational direction of the photosensitive drum 15 with respect to the rear end part. A belt-like first rubber blade 17 whose rear end is fixed to the first blade holder 16 toward the upstream side, and whose lower edge is in contact with the surface of the photosensitive drum 15; The transfer residual toner and the lubricant scraped off by the first rubber blade 17 are rotatably provided in an area defined by the first rubber blade 17 and the cartridge case 14 and are conveyed to a storage unit (not shown). The transfer of residual toner and lubricant scraped off by the first rubber blade 17 while wearing the first powder conveying screw 18 and the right end of the opening on the upper surface of the cartridge case 14 exposing the upper portion of the photosensitive drum 15. And a scattering prevention sheet 19 for preventing.

  The lubricant application section is driven by a drive means (not shown) in the clockwise direction in the drawing so as to be in contact with the surface of the photosensitive drum 15 and a brush roller 20 as a lubricant application means, and a metal soap such as zinc stearate. And a lubricant 21 for increasing the releasability of the toner image, that is, transfer efficiency, and a lubricant support portion 22 that supports the lubricant 21 and presses against the brush roller 20 to rub the lubricant 21. This lubricant application means is provided below the first cleaning unit, and the brush roller 20 to which the lubricant has been applied rotates on the surface of the photosensitive drum 15 that has been substantially cleaned by the first cleaning unit. The lubricant is applied by contact.

  The second cleaning unit includes a second blade holder 23 formed in a substantially L shape in side view and attached to the right middle portion of the cartridge case 14 below the lubricant applying means, and a front end portion with respect to the rear end portion. Is attached to the second blade holder 23 so that the end of the photosensitive drum 15 is upstream of the rotation direction of the photosensitive drum 15, and one edge (left edge in the drawing) of the leading end is on the surface of the photosensitive drum 15. A second rubber blade is rotatably provided in an area defined by the abutted strip-shaped second rubber blade 24, the second rubber blade 24, the cartridge case 14, and the lubricant applying means. And a second powder conveying screw 25 that conveys the transfer residual toner and the lubricant scraped off by the blade 24 to a storage unit (not shown).

The first rubber blade 17 and the second rubber blade 24 are both made of the same material (for example, silicon rubber) and are formed with the same width and the same thickness t (for example, about 1 to 3 mm) as shown in FIG. Only the free length L, which is the length of the rubber blade protruding from the blade holder, is longer in the second rubber blade 24 than in the first rubber blade 17.
Then, the biting amount dp (initial compression amount of the edge portion in contact with the photosensitive drum 11; for example, about 0.65 mm) to the photosensitive drum is also made the same, and the tangent of the photosensitive drum 15 at the lower edge of the front end portion. A counter is attached to the cartridge case 14 via the first blade holder 16 and the second blade holder 23 so that the contact angle θ, which is an angle formed with the tip surface of the tip portion, is 70 degrees or more and 90 degrees or less. It is attached with a formula.
The second rubber blade 24 is provided with a required space from the first rubber blade 17. The second rubber blade 24 is formed in the space formed by the first rubber blade 17 and the second rubber blade 24 and the second rubber blade. A brush roller 20 is provided so as to be separated from the blade 24.
In this manner, the contact pressure when the second rubber blade 24 is stationary is made lower than the contact pressure when the first rubber blade 17 is stationary. As the ratio, for example, when the contact pressure when the first rubber blade 17 is stationary is 1.0, the contact pressure when the second rubber blade 24 is stationary is approximately 0.8.

  As shown in FIG. 2, the charging device is provided with a charging roller 26 that is pressed against the photosensitive drum 15 by a pressing spring and is rotated in a counterclockwise direction to charge the surface of the photosensitive drum 15, and a pressing spring. A cleaner roller 27 that is pressed by the charging roller 26 and is rotatably driven by the charging roller 26 is disposed near the lowermost portion of the photosensitive drum 15.

  As shown in FIG. 2, in the developing device, the photosensitive drum 15 is irradiated with scanning light from the exposure device 6 through the opening of the cartridge case 14 formed between the developing device and the charging device. A developing roller 28 for supplying toner to the electrostatic latent image formed in step 1 and developing the toner image, and a pair of left and right conveying screws 30 for conveying the toner from the toner supply unit 29 to the developing roller 28, and a photoconductor Arranged on the left side of the drum 15.

The operation of the image forming apparatus according to the present embodiment configured as described above will be described with reference to FIGS.
The photosensitive drum 15 is rotated in the clockwise direction in the figure by driving means (not shown), and the surface of the photosensitive drum 15 is uniformly charged to a predetermined polarity by the charging device. Scanning light is irradiated from the exposure device 6 toward the charged surface of the photosensitive drum 15, whereby an electrostatic latent image is formed on the surface of the photosensitive drum 15. At this time, the image information exposed to each photosensitive drum 15 is single-color image information obtained by separating a desired full-color image into color information of yellow, magenta, cyan, and black. The electrostatic latent image is visualized as a toner image by the developing device.

  The intermediate transfer belt 3 rotates counterclockwise in the figure, and each color toner image is sequentially transferred from the photosensitive drum 15 to the intermediate transfer belt 3 by the action of the primary transfer roller 4 in each of the process cartridges 5Y, 5M, 5C, and 5K. . In this way, a full-color toner image is formed on the surface of the intermediate transfer belt 3. Note that a single color image is formed using any one of the process cartridges 5Y, 5M, 5C, and 5K, or two or three of the plurality of process cartridges 5Y, 5M, 5C, and 5K are used. A color or three-color image can also be formed. In the case of monochrome printing, among the four process cartridges 5Y, 5M, 5C, and 5K, image formation is performed using the rightmost black process cartridge 5K in the drawing.

  Before and after the above operation, the sheet feeding roller 8 starts conveying the sheet from the sheet tray 7. The sheet that has started to be conveyed is sent out toward the secondary transfer position by the registration roller pair 10 in accordance with the movement of the toner image carried on the intermediate transfer belt 3, and the surface of the intermediate transfer belt 3 by the secondary transfer roller 9. The toner image is transferred. The sheet carrying the toner image is sent to the fixing device 11, and the toner image is melted and fixed on the sheet by heat and pressure, and is discharged to the discharge tray unit 12 by the discharge roller pair 13.

On the other hand, in each process cartridge, the surface of the photoconductor drum 15 after the toner image is transferred to the intermediate transfer belt 3 is attached with the transfer residual toner and the lubricant. Most of the toner and lubricant are scraped off, and the scraped transfer residual toner and lubricant are transported to a storage unit (not shown) by the first powder transport screw 18.
The surface of the photosensitive drum 15 that has passed through the first rubber blade 17 is coated with a lubricant by the brush roller 20.

  On the surface of the photosensitive drum 15 to which the lubricant is applied, in addition to the newly applied lubricant, a slight amount of transfer residual toner or lubricant that has passed through the first rubber blade 17 is attached. The lubricant is evenly leveled while being scraped off by the two rubber blades 24. Then, the scraped transfer residual toner and lubricant start to accumulate in the region between the tip surface of the second rubber blade 24 and the surface of the photosensitive drum 15, and eventually, only the amount overflowed from the region falls. . The transfer residual toner and the lubricant that have fallen are transported to a storage unit (not shown) by the second powder transport screw 25.

  At this time, since the second rubber blade 24 has a smaller frictional resistance than the first rubber blade 17, the blade edge of the second rubber blade 24 is broken, the blade is turned over, abnormal noise, abnormal wear, etc. It is hard to happen. In addition, the first rubber blade 17 moves toward the downstream side in the rotation direction of the photosensitive drum 15 with reference to the transfer position on the photosensitive drum 15 where the toner image carried on the photosensitive drum 15 is transferred to the intermediate transfer belt 3. Since the brush roller 20 and the second rubber blade 24 are arranged in this order, the applied lubricant further reduces the frictional resistance, so that the occurrence of the above-described problems can be greatly reduced.

  The surface of the photosensitive drum 15 that has passed through the cleaning device is uniformly charged to a predetermined polarity by the above-described charging device to prepare for the next image formation.

Next, toner used in the image forming apparatus according to the present embodiment will be described.
The toner used in this exemplary embodiment has a volume average particle diameter of 3 to 8 μm and a ratio (Dv / Dn) of volume average particle diameter (Dv) to number average particle diameter (Dn) of 1.00 to 1.40. The one in the range is used. Therefore, according to such a toner, the toner charge amount distribution is uniform, and a high-quality image with little background fogging can be obtained. Further, in the image forming apparatus using the electrostatic transfer method, the transfer rate can be increased.

  In response to the recent demand for high image quality, the toner preferably has a volume average particle diameter of 3 to 8 μm in order to reproduce fine dots of 600 dpi or more in the formed image. On the other hand, the ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) is preferably in the range of 1.00 to 1.40. That is, the closer this ratio (Dv / Dn) is to 1.00, the sharper the particle size distribution. In such a toner having a small particle size and a narrow particle size distribution, the toner charge amount distribution is uniform, so that a high-quality image with little background fogging can be obtained, and the transfer rate is high in the electrostatic transfer method. can do.

  Further, toner having a shape factor SF-1 in the range of 100 to 180 and a shape factor SF-2 in the range of 100 to 180 is used. Therefore, when the shape of the toner is close to a sphere, the contact state between the toner and the toner, or the contact state between the toner and the photosensitive member becomes a point contact, so that the adsorbing force between the toners becomes weak and the fluidity increases. Further, the attracting force between the toner and the photoreceptor is weakened, and the transfer rate is increased. If any of the shape factors SF-1 and SF-2 exceeds 180, the transfer rate decreases. Therefore, the transfer rate can be increased by setting the range of SF-1 and SF-2 to 100 to 180. .

  That is, it is preferable that the shape factor SF-1 of the toner is in the range of 100 to 180, and the shape factor SF-2 is in the range of 100 to 180. The shape factor SF-1 and the shape factor SF-2 will be described with reference to the diagrams schematically showing the shape of the toner D in FIGS.

As shown in FIG. 4A, the shape factor SF-1 indicates the ratio of the roundness of the toner shape, and is represented by the following formula (1). SF-1 is a value obtained by dividing the square of the maximum length MXLNG of the shape formed by projecting toner onto a two-dimensional plane by the figure area AREA and multiplying by 100π / 4.
SF-1 = {(MXLNG) 2 / AREA} × (100π / 4) Expression (1)
When the value of SF-1 is 100, the shape of the toner is a true sphere, and becomes irregular as the value of SF-1 increases.

Further, as shown in FIG. 4B, the shape factor SF-2 indicates the ratio of the unevenness of the toner shape, and is represented by the following formula (2). A value obtained by dividing the square of the perimeter PERI of the figure formed by projecting the toner on the two-dimensional plane by the figure area AREA and multiplying by 100π / 4.
SF-2 = {(PERI) 2 / AREA} × (100π / 4) (2)
When the value of SF-2 is 100, there is no unevenness on the toner surface, and the unevenness of the toner surface becomes more prominent as the value of SF-2 increases. Specifically, the shape factor is measured by taking a photograph of the toner with a scanning electron microscope (S-800: manufactured by Hitachi, Ltd.), and introducing it into an image analyzer (LUSEX 3: manufactured by Nireco) for analysis. And calculated.

  Therefore, when the shape of the toner is close to a sphere, the contact state between the toner and the toner or between the toner and the photoconductor becomes a point contact. For this reason, the attractive force between the toners becomes weak, and therefore the fluidity becomes high, and the attractive force between the toner and the photosensitive member becomes weak, and the transfer rate becomes high. However, if any of the shape factors SF-1 and SF-2 exceeds 180, the transfer rate decreases, which is not preferable.

  The toner suitably used in the image forming apparatus of this embodiment is a toner material in which at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent are dispersed in an organic solvent. The toner is obtained by crosslinking and / or elongation reaction of the liquid 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, the charging stability tends to be lowered, and in particular, it tends to be easily affected by environmental fluctuations.
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 decreases. On the other hand, if it exceeds 400,000, the low-temperature fixability is lowered, which is not preferable.

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

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

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

  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 is lowered, 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 is lowered, and the hot offset resistance is lowered.

  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 the compound (B6) obtained by blocking the amino group of B1 to B5 include ketimine compounds and oxazolidine compounds obtained from the amines of B1 to B5 and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Among these amines (B), preferred are B1 and a mixture of B1 and a small amount of B2.

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

  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 decreases.

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

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

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

  Use of unmodified polyester and urea-modified polyester in combination improves the low-temperature fixability and gloss of the image obtained when used in a full-color image forming apparatus, so it is preferable to use 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. If the weight ratio of the urea-modified polyester is less than 5%, the hot offset resistance is lowered, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

The glass transition point (Tg) of the binder resin containing unmodified polyester and urea-modified polyester is usually 45 to 65 ° C, preferably 45 to 60 ° C. If it is less than 45 ° C., the heat resistance of the toner is lowered, and if it exceeds 65 ° C., the low-temperature fixability becomes insufficient.
In addition, since the urea-modified polyester is likely to be present on the surface of the obtained toner base particles, the heat-resistant storage stability tends to be good even when the glass transition point is low as compared with known polyester-based toners.

(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 , Yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Vulcan fast yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Phi Sayred, Parachlor Ortonito Aniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant 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, Thio Indigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red Polyazo Red, Chrome Vermillion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), indigo, ultramarine blue, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Lid Russian nin green, anthraquinone green, titanium oxide, zinc white, litbon and mixtures thereof can be used. The content of the colorant is usually 1 to 15% by weight, preferably 3 to 10% by weight, based on the toner.

  The colorant can also be used as a master batch combined with a resin. As a binder resin to be kneaded 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 PSY VP2038, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (Nippon Carlit) Manufactured), copper phthalocyanine, perylene, quinacridone, azo series Fee, a sulfonic acid group, a carboxyl group, and polymer compounds having a functional group such as quaternary ammonium salts. Of these, substances that control the negative polarity of the toner are particularly preferably used.

  The amount of charge control agent used is determined by the type of binder resin, the presence or absence of additives used as necessary, and the toner production method including the dispersion method, and is not uniquely limited. Preferably, it is used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the charge control agent is reduced, the electrostatic attraction force with the developing roller 28 is increased, the developer fluidity is reduced, and the image density is increased. Cause a decline.

(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. Even if a release agent such as oil is not applied, a useful effect against high temperature offset can be obtained. 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 master batch and the binder resin, or may be added when dissolved or 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 to 2 μm, and more preferably 5 × 10 −3 to 0.5 μm. The specific surface area by the BET method is preferably 20 to 500 m <2> / 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. Particularly when both the fine particles have an average particle size of 5 × 10 −2 μm or less and are stirred and mixed, the electrostatic force and van der Waals force with the toner are remarkably improved. Therefore, even with stirring and mixing inside the developing device to obtain a desired charge level, the fluidity-imparting agent is not detached from the toner, and a good image quality that does not generate fireflies can be obtained. Reduction of residual toner is achieved.

  Titanium oxide fine particles are excellent in environmental stability and image density stability, but tend to deteriorate the charge rising characteristics. For this reason, when the amount of titanium oxide fine particles added is larger than the amount of silica fine particles added, it is considered that the influence of this side effect is increased. However, if the addition amount of the hydrophobic silica fine particles and the hydrophobic titanium oxide fine particles is set in the range of 0.3 to 1.5 wt% in consideration of the influence of this side effect, the charge rise characteristics are not greatly impaired, and the desired charge rise is achieved. Characteristics are obtained. That is, stable image quality can be obtained even when copying, that is, image formation is repeated.

  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, 124a, 124b, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fgentent F-100, F150 (manufactured by Neos).

  Moreover, as the cationic surfactant, aliphatic quaternary ammonium such as aliphatic primary, secondary or secondary amic acid, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt which has a right fluoroalkyl group is used. Salt, 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) Smoke), Megafac F-150, F-824 (Dainippon Ink Co., Ltd.), Xtop EF-132 (Tochem Products), Footage F-300 (Neos), and the like.

  The resin fine particles are added to stabilize the toner base particles formed in the aqueous medium. For this reason, it is preferable to add so that the coverage existing on the surface of the toner base particles is in the range of 10 to 90%. For example, polymethyl methacrylate fine particles 1 μm and 3 μm, polystyrene fine particles 0.5 μm and 2 μm, poly (styrene-acrylonitrile) fine particles 1 μm, trade names are PB-200H (manufactured by Kao), SGP (manufactured by Soken), Techno Examples include polymer SB (manufactured by Sekisui Chemical Co., Ltd.), SGP-3G (manufactured by Sokensha), and micropearl (manufactured by Sekisui Fine Chemical Co., Ltd.). 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, the high-speed shearing method is preferable in order to make the particle size of the dispersion 2 to 20 μm. When a high-speed shearing disperser is used, the rotational speed is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 40 to 98 ° C.

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

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

5) A charge control agent is injected into the toner base particles obtained above, and then inorganic fine particles such as silica fine particles and titanium oxide fine particles are externally added to obtain a toner.
The injection of the charge control agent and the external addition of the inorganic fine particles are performed by a known method using a mixer or the like. Thereby, a toner having a small particle size and a sharp particle size distribution can be easily obtained. Furthermore, by applying strong agitation in the process of removing the organic solvent, it is possible to control the shape from a spherical shape to a rugby ball shape. It can be arbitrarily controlled up to the shape.

  Therefore, according to the toner constituent material and the manufacturing method described above, it is possible to easily obtain a toner having a small particle size and a sharp particle size distribution. Furthermore, by giving strong agitation in the process of removing the organic solvent, the shape can be controlled in a range from true sphere to rugby ball shape, and the surface morphology is also smooth to plum blossom shape Can be controlled in the range between.

  Further, the shape of the toner suitably used in the image forming apparatus of this embodiment is a substantially spherical shape, and the shape of the toner represented by the following shape definition is defined by the major axis r1, the minor axis r2, and the thickness r3. (Where r1 ≧ r2 ≧ r3), the ratio of the major axis r1 to the minor axis r2 (r2 / r1) is in the range of 0.5 to 1.0, and the thickness r3 and minor axis r2 The ratio (r3 / r2) in the range of 0.7 to 1.0 is used.

  That is, description will be given based on FIGS. 5A to 5C schematically showing the shape of the toner D. FIG. As shown in FIG. 5A, when a substantially spherical toner is defined by a major axis r1, a minor axis r2, and a thickness r3 (where r1 ≧ r2 ≧ r3), this toner is As shown in FIG. 5 (b), the ratio of the major axis to the minor axis (r2 / r1) is 0.5 to 1.0, and as shown in FIG. r3 / r2) is preferably in the range of 0.7 to 1.0.

  If the ratio of the major axis to the minor axis (r2 / r1) is less than 0.5, the toner is spherical and away from the true spherical shape, so that dot reproducibility and transfer efficiency are inferior, 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.

  In addition, as a concrete measuring method of r1, r2, r3, it measured with the scanning electron microscope (SEM), changing the angle of a visual field, taking a photograph, and observing.

  Accordingly, since the toner used in the image forming apparatus has a substantially spherical shape, dot reproducibility and transfer efficiency can be improved. In particular, 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 of the present invention has a ratio of the major axis to the minor axis. When the configuration is such that (r2 / r1) is in the range of 0.5 to 1.0 and the ratio of thickness to minor axis (r3 / r2) is in the range of 0.7 to 1.0, the toner shape is a true sphere shape. Close to. For this reason, dot reproducibility and transfer efficiency can be improved. As a result, high quality image quality can be obtained.

As described above, in the present embodiment, the first rubber blade 17 and the second rubber blade 24 are made of a common material, have the same width and the same thickness, and the free length that is the length of the rubber blade protruding from the blade holder. Only the L is formed so that the second rubber blade 24 is longer than the first rubber blade 17. The contact angle that is the angle between the tangent line of the photosensitive drum 15 and the front end surface of the front end portion so that the amount dp of biting into the photoconductive drum 15 becomes the same, and the contact side edge of the front end portion. It is attached to the cartridge case 14 via the first blade holder 16 and the second blade holder 23 so that θ (see FIG. 3) is 70 degrees or more and 90 degrees or less.
With this configuration, the contact pressure when the second rubber blade 24 is stationary is lower than the contact pressure when the first rubber blade 17 is stationary, and the frictional resistance is reduced. Problems such as chipping, blade turning, abnormal noise, and abnormal wear of the blade 24 can be reduced with a simple configuration. Moreover, since the lubricant applied by the brush roller 20 further reduces the frictional resistance, the occurrence of the above-described problems can be greatly reduced.

  The brush roller 20 that applies a lubricant to the surface of the photosensitive drum 15 is separated from the second rubber blade 24 in the space formed by the first rubber blade 17 and the second rubber blade 24. By providing the second rubber blade 24, the second rubber blade 24 functions not only for scraping off the transfer residual toner that has passed through the first rubber blade 17 and the brush roller 20, but also sufficient for leveling the lubricant. Since elastic deformation is obtained, it is possible to avoid the possibility of unevenness in the leveling of the lubricant.

The image forming apparatus according to the present embodiment has been described above. However, the above-described embodiment shows an example of a preferred embodiment of the present invention, and the present invention is not limited thereto. Various modifications can be made without departing from the scope of the invention.
For example, in the present embodiment, the example in which the lubricant application unit is provided between the first cleaning unit and the second cleaning unit is illustrated, but the present invention can also be applied to a cleaning device without the lubricant application unit.
Further, the process cartridges 5Y, 5M, 5C, and 5K of the present embodiment have been illustrated as having a cleaning device, a photosensitive drum 15 that is an image carrier, a charging unit, and a developing unit. Of these, only one of the charging means and the developing means may be provided.

5 Process Cartridge 15 Photosensitive Drum 16 First Blade Holder 17 First Rubber Blade 20 Brush Roller 23 Second Blade Holder 24 Second Rubber Blade

JP-A-2005-352310 JP 2000-330443 A

Claims (10)

The edge of the leading end is brought into contact with the surface of the rotatable image carrier that carries the toner image to be transferred to the transfer target, and the leading end is upstream in the rotation direction of the image carrier with respect to the rear end. A first rubber blade in the form of a strip plate, the rear end of which is supported by the first blade holder;
The edge of the tip on the surface of the image carrier downstream of the first rubber blade in the rotation direction of the image carrier with respect to the transfer position on the image carrier to which the toner image is transferred to the transfer body Is provided with a required space from the first rubber blade so that the front end portion is directed upstream of the rear end portion in the rotation direction of the image carrier. A belt-like second rubber blade having a portion supported by a second blade holder ;
A lubricant application means provided between the first rubber blade and the second rubber blade for applying a lubricant to the surface of the image carrier;
Powder that is rotatably provided in an area defined by the second rubber blade and the lubricant application means, and conveys transfer residual toner and lubricant scraped off by the second rubber blade to the storage unit. A body conveying screw ,
The length of the rubber blade protruding from the blade holder is the free length,
The second rubber blade has a free length longer than the free length of the first rubber blade so that the stationary contact pressure of the second rubber blade is lower than that of the first rubber blade. Cleaning device to do.   The contact angle, which is the angle formed between the tangent line of the image carrier at the edge of the tip portion and the tip surface of the tip portion, is 70 degrees or more and 90 degrees for both the first rubber blade and the second rubber blade. The cleaning device according to claim 1, wherein the cleaning device is less than or equal to a degree.   The cleaning device according to claim 1, wherein the first rubber blade and the second rubber blade are made of the same material or a material having equivalent physical properties.   The first rubber blade and the second rubber blade are formed with the same width and the same thickness, and the amount of biting into the image carrier is the same. The cleaning device according to claim 1. The cleaning apparatus according to claim 1, wherein the lubricant application unit is a brush roller . An electrostatic latent image formed on the image carrier, comprising: a cleaning device according to any one of claims 1 to 5; and the image carrier, a charging unit that charges the surface of the image carrier. A process cartridge comprising: one or both of developing means for developing the toner image into the toner image and detachably integrated with the main body of the image forming apparatus . An image forming apparatus comprising the cleaning device according to claim 1 or the process cartridge according to claim 6 . The toner for forming the toner image has a volume average particle diameter (Dv) in the range of 3 to 8 μm, and a ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn). The image forming apparatus according to claim 7, wherein the degree of dispersion defined by the above is in a range of 1.00 to 1.40 . The toner for forming the toner image has a shape factor SF-1 in the range of 100 to 180, and a shape factor SF-2 in the range of 100 to 180. Image forming apparatus . The toner for forming the toner image is substantially spherical, and the ratio of the major axis to the minor axis (r2 / r1) is in the range of 0.5 to 1.0, and the ratio of the thickness to the minor axis (r3 / r2). 8 is a range of 0.7 to 1.0, and satisfies the relationship of major axis r1 ≧ minor axis r2 ≧ thickness r3 .

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