JP4638179B2 - Cleaning device and image forming apparatus - Google Patents

Description

  The present invention relates to a cleaning device for cleaning an outer peripheral surface of an image carrier and an image forming apparatus using the cleaning device.

  Conventionally, in an electrophotographic image forming apparatus, a toner image is carried on an image carrier such as a photoreceptor or an intermediate transfer belt, and the toner image is transferred to a transfer member such as a recording medium to form an image. The outer peripheral surface of the image carrier after the transferred toner image is cleaned by a cleaning device, and the remaining foreign matters such as toner and paper dust are removed.

  As an example of a cleaning device that cleans the outer peripheral surface of an image carrier, a device that includes a brush roller and a cleaning blade is known, as disclosed in Patent Document 1. In a cleaning device provided with a brush roller and a cleaning blade, the paper roller attached to the outer peripheral surface of the image carrier is wiped off by rotation of the brush roller having the brush in contact with the outer peripheral surface of the image carrier. Thus, the toner adhering to the outer peripheral surface of the image carrier is removed so as to be scraped off when the contact portion of the cleaning blade contacts the outer peripheral surface of the image carrier.

Japanese Patent Laid-Open No. 10-282854

  Foreign matter such as toner removed from the outer peripheral surface of the image carrier adheres to the contact portion of the cleaning blade that is in contact with the outer peripheral surface of the image carrier. If the toner blade or other foreign matter adheres to the contact portion of the cleaning blade, the cleaning performance of the image carrier by the cleaning blade will deteriorate and the outer peripheral surface of the image carrier will become dirty. As a result, the quality of the image formed decreases. Therefore, it is necessary to periodically clean the contact portion of the cleaning blade, but this cleaning is troublesome and cumbersome.

  An object of the present invention is to easily perform cleaning of foreign matters adhering to a contact portion of a cleaning blade without taking time and effort.

According to a first aspect of the present invention, there is provided a cleaning device comprising: a brush roller which is brought into contact with an outer peripheral surface of an image carrier and rotated in a direction along a traveling direction of the image carrier; and the image of the brush roller. A cleaning blade disposed on the downstream side in the traveling direction of the carrier with the abutting portion in contact with the outer circumferential surface of the image carrier facing the brush roller, and the abutting portion serving as the outer circumferential surface of the image carrier. A case positioned at a position for receiving the foreign matter scraped off from the outer peripheral surface of the image carrier by the cleaning blade abutted on the image sensor, and an abutment for bringing the contact portion into contact with the outer peripheral surface of the image carrier the position and the contacting portion supporting said cleaning blade to be movable in a separate position of separating from the outer peripheral surface of the image bearing member, the abutment portion with the moving of the cleaning blade to the separate position, said image Burden Comprising a moving mechanism for moving the position where it comes into contact with the brush of the brush roller in a direction along the traveling direction of the body being rotated, the.

According to a second aspect of the invention, the cleaning device according to claim 1 Symbol placement, the material of the brush of the brush roller is a chemical fiber.

According to a third aspect of the present invention, there is provided an image forming apparatus that is rotatably supported and carries a toner image on an outer peripheral surface thereof, and a transfer device that transfers the toner image on the image carrier to a member to be transferred. And a cleaning device according to claim 2 , wherein the outer peripheral surface of the image carrier after the toner image is transferred is cleaned .

According to a fourth aspect of the present invention, in the image forming apparatus according to the third aspect , the shape of the toner used for forming the toner image is defined by a major axis r1, a minor axis r2, and a thickness r3 (provided that r1 ≧ r2 ≧ r3), the ratio (r2 / r1) between the major axis r1 and the minor axis r2 is set in the range of 0.5 to 1.0, and the ratio between the thickness r3 and the minor axis r2 (r3 / r2) is set in the range of 0.7 to 1.0.

According to the cleaning device of the first aspect of the present invention, when the cleaning blade is moved to the separation position where the contact portion is separated from the image carrier by the contact / separation mechanism, the contact portion is along the traveling direction of the image carrier. since moved to a position abutting the brush of the brush roller which is rotated in the direction, it is possible to remove the brushes of the brush roller to rotate is attached to the abutment by interfering with abutment foreign substances, those The contact portion can be easily cleaned without trouble. Then, the brush of the brush roller is driven to rotate in a direction along the traveling direction of the image carrier, and the contact portion of the cleaning blade is directed to the brush roller, and the brush roller is downstream along the traveling direction of the image carrier. Arranged on the side. Thus, the foreign matter removed by the contact portion can be blown toward the case, and the amount of movement when the contact portion of the cleaning blade is moved to a position where the contact portion of the brush roller contacts the brush can be reduced. Therefore, the foreign matter removed from the contact portion can be prevented from adhering to the image carrier again, the foreign matter removed from the contact portion can be reliably collected, and the structure of the contact / separation mechanism can be simplified. It can be.

According to the cleaning device of the second aspect of the invention, it is possible to set the desired state with respect to the shape of the brush tip, the thickness of the brush, the conductivity and non-conductivity of the brush, and the like. It is possible to improve the performance of removing the adhered foreign matter and the performance of removing the foreign matter from the image carrier by the brush roller .

According to the image forming apparatus of the invention described in claim 3, the same effect as that of any one of claims 1 to 2 can be obtained.

According to the image forming apparatus of the fourth aspect of the present invention, this toner can improve dot reproducibility and transfer efficiency, and improve toner fluidity, and a high-quality image can be obtained.

The implementation of the embodiment of the present invention will be described with reference to FIGS. 1 to 6. FIG. 1 is a longitudinal side view schematically showing a color printer as an image forming apparatus, FIGS. 2 and 3 are longitudinal side views showing the cleaning device in an enlarged manner, and FIG. 4 is for explaining the toner shape factor SF-1. FIG. 5 is an explanatory view schematically showing the shape of the toner, FIG. 5 is an explanatory view schematically showing the shape of the toner for explaining the toner shape factor SF-2, and FIG. 6 is an explanatory view showing the shape of the toner schematically. FIG.

  As shown in FIG. 1, four printer engines 3 (3Y, 3C, 3M, 3K) and optical writing for emitting a light beam are provided in a substantially central portion inside a main body case 2 of a color printer 1 as an image forming apparatus. An apparatus 4 and an intermediate transfer belt 5 as an image carrier are disposed. Each printer engine 3 is a portion for forming a toner image, and is formed in the same structure. Each printer engine 3 uses a different color toner, whereby a different color toner image is formed. In the description of the present specification and drawings relating to the printer engine 3 and the components of the printer engine 3, the subscripts Y, C, M, and K indicate yellow, cyan, magenta, and black, respectively. These subscripts are omitted as necessary.

  The mechanical structures of the four printer engines 3Y, 3C, 3M, and 3K are the same. Each printer engine 3 includes a photosensitive member 6 that is driven to rotate in the direction of an arrow, a charging device 7 that is disposed around the photosensitive member 6, The developing device 8 and the cleaning device 9 are configured.

  The photosensitive member 6 is formed in a cylindrical shape and is connected to a driving source (not shown), and rotates around the center line by a driving force from the driving source. A photosensitive layer is provided on the outer peripheral surface of the photoreceptor 6.

  The charging device 7 includes a charging roller 7 a that is disposed in contact with the outer peripheral surface of the photosensitive member 6 or that is disposed with a small gap from the outer peripheral surface of the photosensitive member 6. When a voltage is applied to the charging roller 7a from a power supply unit (not shown), corona discharge is generated between the charging roller 7a and the photosensitive member 6, and the outer peripheral surface of the photosensitive member 6 is uniformly charged. The

  The optical writing device 4 emits light according to the image data, and exposes the outer peripheral surface of the uniformly charged photoreceptor 6. By this exposure, an electrostatic latent image corresponding to the image data is formed on the outer peripheral surface of the photoreceptor 6.

  The developing device 8 supplies toner to the photoreceptor 6. The supplied toner adheres to the electrostatic latent image formed on the outer peripheral surface of the photoconductor 6, and the electrostatic latent image on the outer peripheral surface of the photoconductor 6 is visualized as a toner image. The toner image on the outer peripheral surface of the photoreceptor 6 is transferred onto the intermediate transfer belt 5.

  The intermediate transfer belt 5 is a loop-shaped belt formed using a resin film or rubber as a base, and is supported by rollers 10, 11, 12 and proceeds in the direction of arrow A. Four transfer rollers 13 for transferring the toner image on each photoconductor 6 onto the intermediate transfer belt 5 are arranged on the inner peripheral surface side (inside the loop) of the intermediate transfer belt 5. The toner images formed on the respective photoreceptors 6 are sequentially transferred onto the intermediate transfer belt 5 so that a color toner image is carried on the intermediate transfer belt 5.

  The cleaning device 9 cleans the outer peripheral surface of the photoreceptor 6 after the toner image is transferred to the intermediate transfer belt 5. This cleaning removes toner, paper dust, and the like remaining on the outer peripheral surface of the photoreceptor 6 when the toner image is transferred.

  Below the four printer engines 3 and the optical writing device 4 in the main body case 2, a paper feed cassette 15 in which recording media P as transfer members are stacked and held is disposed. The recording media P stacked and held in the paper feed cassette 15 are separately fed by the paper feed roller 16 in order from the highest one.

  In the main body case 2, a transport path 17 is formed through which the recording medium P separated and fed from the paper feed cassette 15 is transported. On this conveyance path 17, a registration roller 18, a transfer device 19, a fixing device 20, a paper discharge roller 21, and the like are arranged.

  The registration roller 18 is driven to rotate intermittently at a predetermined timing. By intermittently driving the registration roller 18, the recording medium P that has been transported to the position of the registration roller 18 and stopped is sent to a transfer position that is sandwiched between the intermediate transfer belt 5 and the transfer device 19.

  The transfer device 19 is applied with a transfer voltage at the timing when the recording medium P conveyed through the conveyance path 17 is sent between the intermediate transfer belt 5 and the transfer device 19, and the toner image on the intermediate transfer belt 5 is recorded. Transferred to the medium P.

  The fixing device 20 applies heat and pressure to the recording medium P to which the toner image is transferred to melt the toner, and fixes the toner image to the recording medium P. The recording medium P on which the toner image has been fixed by passing through the fixing device 20 is discharged onto a discharge tray 22 formed on the upper surface of the main body case 2 by a discharge roller 21.

  On the outer peripheral surface side of the intermediate transfer belt 5 (outside the loop), the outer peripheral surface of the intermediate transfer belt 5 after the toner image is transferred to the recording medium P is cleaned, and the outer periphery of the intermediate transfer belt 5 is transferred when the toner image is transferred. A cleaning device 14 for removing foreign matters such as toner and paper dust remaining on the surface is disposed.

  The cleaning device 14 is disposed at a position facing the outer peripheral surface of the intermediate transfer belt 5 and facing the roller 10 that supports the intermediate transfer belt 5, and includes a brush roller 23, a cleaning blade 24, a case 25, and a contact / separation mechanism. 26, a solid lubricant 27, a conveying screw 28, and the like. As for the brush roller 23 and the cleaning blade 24, the brush roller 23 is disposed on the upstream side along the traveling direction (arrow A direction) of the intermediate transfer belt 5, and the cleaning blade 24 is disposed on the downstream side. As the solid lubricant 27, zinc stearate, PTFE (polytetrafluoroethylene) or the like is used.

  The brush roller 23 includes a brush shaft 23a and a brush 23b planted on the outer periphery of the brush shaft 23a. The brush roller 23 is driven to rotate by bringing the brush 23b into contact with the outer peripheral surface of the intermediate transfer belt 5 and the solid lubricant 27. . The rotation direction of the brush roller 23 is a clockwise direction indicated by an arrow B, and is a direction along the traveling direction of the intermediate transfer belt 5. Further, the brush 23 b is disposed so as to abut on the entire lateral width direction of the intermediate transfer belt 5 orthogonal to the traveling direction of the intermediate transfer belt 5. The brush 23b is formed of chemical fibers (nylon, polyester, polypropylene, rayon, etc.), and the thickness, length, shape of the tip, electrical characteristics (conductive, non-conductive), etc. are set as necessary. Yes.

  By rotating the brush roller 23 while the brush 23b is brought into contact with the outer peripheral surface of the intermediate transfer belt 5, foreign matters such as paper dust and toner adhering to the outer peripheral surface of the intermediate transfer belt 5 are removed. Is done. Further, the brush 23 b is brought into contact with the solid lubricant 27 and the outer peripheral surface of the intermediate transfer belt 5 to rotate the brush roller 23, whereby the solid lubricant 27 is scraped and applied to the outer peripheral surface of the intermediate transfer belt 5. The

  The cleaning blade 24 is formed with a contact portion 24a that contacts the entire outer width of the intermediate transfer belt 5 in the lateral width direction perpendicular to the traveling direction of the intermediate transfer belt 5, and this contact portion 24a is formed on the intermediate transfer belt. 5, foreign matter such as paper dust and toner adhering to the outer peripheral surface of the intermediate transfer belt 5 is scraped off and removed. The cleaning blade 24 is disposed with the contact portion 24 a facing the brush roller 23.

  The case 25 accommodates the brush roller 23, the solid lubricant 27, and the like, and is positioned at a position for receiving foreign matter scraped off from the outer peripheral surface of the intermediate transfer belt 5 by the cleaning blade 24. Further, the case 25 is provided with an inlet-side seal 29 that contacts the upstream outer peripheral surface along the traveling direction of the intermediate transfer belt 5 and an outlet-side seal 30 that contacts the side surface of the cleaning blade 24. The cleaning blade 24 is sealed so that foreign matters such as paper dust and toner removed from the intermediate transfer belt 5 are not scattered outside the case 25.

  The conveying screw 28 removes foreign matters such as paper dust and toner that have been removed from the intermediate transfer belt 5 by the brush roller 23 and the cleaning blade 24 and dropped into the case 25 to a toner recycling device or a waste toner collecting device (both not shown). Transport to.

  The contact / separation mechanism 26 includes a holding body 31 that holds the cleaning blade 24, a support shaft 32 that rotatably supports the holding body 31, and an abutment portion 24a of the cleaning blade 24 that is locked to one end of the holding body 31. Formed by a pressure spring 33 that urges the holding body 31 in a direction to contact the outer peripheral surface of the intermediate transfer belt 5, a cam 34 that contacts the holding body 31 and rotates the holding body 31 around the support shaft 32. Has been. A stepping motor (not shown) is connected to the cam 34. FIG. 2 shows a state in which the holding body 31 is rotated to the first predetermined position by the urging force of the pressure spring 33 and the contact portion 24 a of the cleaning blade 24 is in contact with the outer peripheral surface of the intermediate transfer belt 5. is there. FIG. 3 shows a state in which the holding member 31 is rotated to the second predetermined position by rotating the cam 34, and the contact portion 24 a of the cleaning blade 24 is separated from the outer peripheral surface of the intermediate transfer belt 5. When the cleaning blade 24 moves to the position shown in FIG. 3, the contact portion 24 a of the cleaning blade 24 contacts the brush 23 b of the brush roller 23.

  In such a configuration, when the printer 1 forms an image, the cleaning device 14 cleans the intermediate transfer belt 5. When cleaning the intermediate transfer belt 5, the brush roller 23 rotates with the brush 23 b contacting the outer peripheral surface of the intermediate transfer belt 5 and the solid lubricant 27, and the contact portion 24 a of the cleaning blade 24 is transferred to the intermediate transfer belt 5. It is in contact with the outer peripheral surface of the belt 5. As a result, paper dust and toner particles remaining on the outer peripheral surface of the intermediate transfer belt 5 after the toner image on the intermediate transfer belt 5 is transferred to the recording medium P are removed by the brush roller 23 and the cleaning blade 24. Then, the removed foreign matter falls into the case 25. The foreign matter dropped into the case 25 is conveyed to the toner recycling device or the waste toner collecting device by the conveying screw 28.

  When the intermediate transfer belt 5 is cleaned by the cleaning device 14, foreign matters such as paper dust and toner removed from the outer peripheral surface of the intermediate transfer belt 5 adhere to the contact portion 24 a of the cleaning blade 24. Therefore, in order to remove the foreign matter adhering to the contact portion 24a, a predetermined timing, for example, immediately after the printer 1 is turned on, or the number of image formations counted by the counter reaches a predetermined number. The stepping motor is driven at timing or the like, and the cam 34 is rotated from the position shown in FIG. 2 to the position shown in FIG.

  With this rotation of the cam 34, the support 31 rotates around the support shaft 32, and the contact portion 24 b of the cleaning blade 24 moves away from the outer peripheral surface of the intermediate transfer belt 5 and contacts the brush 23 b of the brush roller 23. Move to a touching position.

  When the contact portion 24a moves to a position where the contact portion 24a contacts the brush 23b, the brush 23b of the rotating brush roller 23 interferes with the contact portion 24a, and the foreign matter attached to the contact portion 24a is removed.

  Here, since the cleaning blade 24 is disposed with the contact portion 24a facing the brush roller 23, the amount of movement when the contact portion 24a is moved to the position where the brush roller 23 contacts the brush 23b is reduced. Therefore, the structure of the contact / separation mechanism 26 can be a simple structure.

  Further, since the brush roller 23 is rotationally driven in the direction (arrow B direction) along the traveling direction (arrow A direction) of the intermediate transfer belt 5, the brush 23b rotates by interfering with the contact portion 24a. The foreign matter removed from the contact portion 24 a is blown into the case 25 by the rotation of the brush roller 23. As a result, it is possible to prevent the foreign matter removed from the contact portion 24a from flying again toward the intermediate transfer belt 5 and adhering to the intermediate transfer belt 5, and the foreign matter removed from the contact portion 24a can be reliably put into the case 25. It can be recovered.

  Therefore, it is possible to easily remove the foreign matter adhering to the contact portion 24a without taking time and effort.

  After the removal of the foreign matter adhering to the contact portion 24 a is completed, the cam 34 is rotated to the position shown in FIG. 2 and the support 31 is rotated around the support shaft 32 by the biasing force of the pressure spring 33. Then, the contact portion 24 a of the cleaning blade 24 is brought into contact with the outer peripheral surface of the intermediate transfer belt 5.

Next, the toner used in the printer 1 of the present embodiment will be described.
The toner has a volume average particle diameter of 3 to 8 μm and a ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) is set in a range of 1.00 to 1.40. Yes.

  In order to reproduce minute dots of 600 dpi or more, the volume average particle diameter of the toner is in the range of 3 to 8 μm, and the ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) is It is preferably in the range of 1.00 to 1.40. The closer (Dv / Dn) is to 1.00, the sharper the particle size distribution. With such a toner having a small particle size and a narrow particle size distribution, the toner charge amount distribution is uniform, and a high-quality image with little background fogging can be obtained. In addition, the electrostatic transfer method has a high transfer rate. can do.

  The toner preferably 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. 4 and 5 are explanatory diagrams schematically showing the shape of the toner in order to explain the shape factor SF-1 and the shape factor SF-2 of the toner. The shape factor SF-1 indicates the ratio of the roundness of the toner shape and is represented by the following formula (1). This is a value obtained by dividing the square of the maximum length MXLNG of the shape formed by projecting the toner on a two-dimensional plane by the figure area AREA and multiplying by 100π / 4.

SF-1 = {(MXLNG) ² / AREA} × (100π / 4) (1)
When the value of SF-1 is 100, the shape of the toner is a true sphere, and becomes larger as the value of SF-1 increases.

  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) Expression (2)
When the value of SF-2 is 100, there is no unevenness on the toner surface, and as the SF-2 value increases, the unevenness of the toner surface becomes more prominent.

  Specifically, the shape factor is measured by taking a photograph of the toner with a scanning electron microscope (S-800: manufactured by Hitachi, Ltd.), introducing it into an image analyzer (LUSEX 3: manufactured by Nireco) and analyzing it. Calculated.

  When the shape of the toner is close to a sphere, the contact state between the toner and the toner or the toner and the intermediate transfer belt 5 becomes a point contact, so that the adsorbing force between the toners becomes weak and the fluidity becomes high. Further, the attractive force between the toner and the intermediate transfer belt 5 is weakened, and the transfer rate from the intermediate transfer belt 5 to the recording medium P is increased. If either of the shape factors SF-1 and SF-2 exceeds 180, the transfer rate is lowered, which is not preferable.

In addition, the toner is prepared by subjecting a toner material solution in which at least a polyester prepolymer having a functional group containing a nitrogen atom, polyester, a colorant, and a release agent is dispersed in an organic solvent to a crosslinking reaction or an extension reaction in an aqueous medium. Alternatively, it is formed by a crosslinking reaction and an extension reaction. 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 between a polyhydric alcohol (PO) and a polycarboxylic acid (PC) is carried out in the presence of a known esterification catalyst such as tetrabutoxytitanate or dibutyltin oxide, and heated to 150 to 280 ° C. while reducing the pressure as necessary. The produced water is distilled off to obtain a polyester having a hydroxyl group. The hydroxyl value of the polyester is preferably 5 or more, and the acid value of the polyester is usually 1 to 30, preferably 5 to 20. By giving an acid value, it tends to be negatively charged, and furthermore, when fixing to a recording paper, the affinity between the recording paper and the toner is good and the low-temperature fixability is improved. However, when the acid value exceeds 30, there is a tendency to deteriorate with respect to the stability of charging, particularly environmental fluctuation.

  The weight average molecular weight of the polyester is 10,000 to 400,000, preferably 20,000 to 200,000. A weight average molecular weight of less than 10,000 is not preferable because offset resistance deteriorates. On the other hand, if it exceeds 400,000, the low-temperature fixability is deteriorated.

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

  Examples of the polyvalent isocyanate compound (PIC) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-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; 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 is lowered and hot offset resistance is deteriorated.

  The content of the polyvalent isocyanate compound (PIC) component in the polyester prepolymer (A) having an isocyanate group is usually 0.5 to 40 wt%, preferably 1 to 30 wt%, more preferably 2 to 20 wt%. . If it is less than 0.5 wt%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40 wt%, the low-temperature fixability deteriorates.

  The number of isocyanate groups contained per molecule in the polyester prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2 on average. Five. If it is less than 1 per molecule, the molecular weight of the urea-modified polyester will be low, and the hot offset resistance will deteriorate.

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

  Examples of the divalent amine compound (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′-dimethyldicyclohexyl). Methane, diamine cyclohexane, isophorone diamine, etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.) and the like. Examples of the trivalent or higher polyvalent amine compound (B2) include diethylenetriamine and triethylenetetramine. Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid. Examples of 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 deteriorated.

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

  The urea-modified polyester is produced by a one-shot method or the like. Polyhydric alcohol (PO) and 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 deteriorates. The number average molecular weight of the urea-modified polyester or the like is not particularly limited when the above-mentioned unmodified polyester is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. When the urea-modified polyester is used alone, its number average molecular weight is usually 2000-15000, preferably 2000-10000, more preferably 2000-8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color apparatus are deteriorated.

  By using the unmodified polyester and the urea-modified polyester in combination, the low-temperature fixability and the gloss when used in the full-color image forming apparatus 100 are improved. Therefore, it is preferable to use the urea-modified polyester alone. The unmodified polyester may include a polyester modified with a chemical bond other than a urea bond.

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

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

  The glass transition point (Tg) of the binder resin containing unmodified polyester and urea-modified polyester is usually 45 to 65 ° C, preferably 45 to 60 ° C. If it is less than 45 ° C., the heat resistance of the toner deteriorates, 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 Carmin Min 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, 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 with the developing roller is increased, the developer fluidity is lowered, and the image density is lowered. Invite.
(Release agent)
As a release agent, a low melting point wax having a melting point of 50 to 120 ° C. works more effectively as a release agent in the dispersion with the binder resin between the fixing roller and the toner interface. The effect on high temperature offset is exhibited without applying a release agent such as oil. Examples of such a wax component include the following. Examples of waxes and waxes include plant waxes such as carnauba wax, cotton wax, wood wax, rice wax, animal waxes such as beeswax and lanolin, mineral waxes such as ozokerite and cercin, and paraffin, microcrystalline, And petroleum waxes such as petrolatum. In addition to these natural waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax and polyethylene wax, and synthetic waxes such as esters, ketones, and ethers can be used. Furthermore, fatty acid amides such as 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide, chlorinated hydrocarbon, and low molecular weight crystalline polymer resin, poly-n-stearyl methacrylate, poly-n- A crystalline polymer having a long alkyl group in the side chain such as a homopolymer or copolymer of polyacrylate such as lauryl methacrylate (for example, a copolymer of n-stearyl acrylate-ethyl methacrylate, etc.) can also be used. .

The charge control agent and the release agent can be melt-kneaded together with the master batch and the binder resin, and of course, they may be added when dissolved and dispersed in the 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 particularly preferably 5 × 10 −3 to 0.5 μm. Moreover, it is preferable that the specific surface area by BET method is 20-500 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, silica sand, clay, mica, wollastonite, Examples thereof include diatomaceous earth, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. Among these, as the fluidity imparting agent, it is preferable to use hydrophobic silica fine particles and hydrophobic titanium oxide fine particles in combination. In particular, when stirring and mixing are performed using particles having an average particle size of 5 × 10-2 μm or less, the electrostatic force and van der Waals force with the toner are remarkably improved. Even when stirring and mixing inside the developing device is performed, a fluidity-imparting agent is not detached from the toner, a good image quality that does not cause fireflies and the like is obtained, and a reduction in residual toner is further achieved. .

  Titanium oxide fine particles are excellent in environmental stability and image density stability, but have a tendency to deteriorate the charge rise characteristics. Therefore, if the amount of titanium oxide fine particles added is larger than the amount of silica fine particles added, this side effect is affected. It can be considered large. However, when the added amount of the hydrophobic silica fine particles and the hydrophobic titanium oxide fine particles is in the range of 0.3 to 1.5 wt%, the charge rising characteristics are not greatly impaired, and the desired charge rising characteristics can be obtained, that is, repeated copying. Stable image quality can be obtained even if

Next, a toner manufacturing method will be described. Here, although a preferable manufacturing method is shown, it is not limited to this.
(Toner production method)
1) A toner material solution is prepared by dispersing a colorant, unmodified polyester, a polyester prepolymer having an isocyanate group, and a release agent in an organic solvent.

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

  2) The toner material liquid is emulsified in an aqueous medium in the presence of a surfactant and resin fine particles.

  The aqueous medium may be water alone or an organic solvent such as alcohol (methanol, isopropyl alcohol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.). It may be included.

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

  Further, in order to improve the dispersion in the aqueous medium, a dispersant such as a surfactant and resin fine particles is appropriately added.

  As surfactants, anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt types such as imidazoline, Quaternary ammonium salt type cationic surfactants such as alkyltrimethylammonium salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, pyridinium salt, alkylisoquinolinium salt, benzethonium chloride, fatty acid amide derivative, polyhydric alcohol 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.) 103, 104, 105, 112, 123A, 123B, 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 (Asahi Glass Co., Ltd.), Florard FC-135 (Sumitomo 3M Co., Ltd.), 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 number of rotations is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 40 to 98 ° C.

  3) At the same time as the preparation of the emulsion, the amines (B) are added to cause a reaction with the polyester prepolymer (A) having an isocyanate group.

  This reaction involves a crosslinking reaction or extension reaction of molecular chains, or a crosslinking reaction and extension reaction. 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 base is removed to produce spindle-shaped toner base particles. . Further, when an acid such as calcium phosphate salt or an alkali-soluble material is used as the dispersion stabilizer, the calcium phosphate salt is dissolved from the toner base particles by a method such as dissolving the calcium phosphate salt with an acid such as hydrochloric acid and washing with water. Remove. It can also be removed by operations such as enzymatic degradation.

  5) A charge control agent is injected into the toner base particles obtained above, and then inorganic fine particles such as silica fine particles and titanium oxide fine particles are externally added to obtain a toner.

  The injection of the charge control agent and the external addition of the inorganic fine particles are performed by a known method using a mixer or the like.

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

  The toner has a substantially spherical shape, and the shape is defined by a major axis r1, a minor axis r2, and a thickness r3 (where r1 ≧ r2 ≧ r3), and the major axis r1 and the minor axis r2. The ratio (r2 / r1) is in the range of 0.5 to 1.0, and the ratio (r3 / r2) of the thickness r3 to the minor axis r2 is in the range of 0.7 to 1.0.

  The shape of the toner is substantially spherical and can be expressed by the following shape rule. FIG. 6 is an explanatory diagram schematically showing the shape of the toner. In FIG. 6, 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 this embodiment has a major axis and a minor axis. The ratio (r2 / r1) to the axis (see FIG. 6B) is 0.5 to 1.0, and the ratio (r3 / r2) between the thickness and the minor axis (see FIG. 6C) is 0. It is preferable that it exists in the range of 7-1.0. If the ratio of the major axis to the minor axis (r2 / r1) is less than 0.5, the dot reproducibility and transfer efficiency are inferior because of the separation from the true spherical shape, and high image quality cannot be obtained. On the other hand, if the ratio of thickness to minor axis (r3 / r2) is less than 0.7, the shape is close to a flat shape, and a high transfer rate like a spherical toner cannot be obtained. In particular, when the ratio of the thickness to the minor axis (r3 / r2) is 1.0, the rotating body has a major axis as a rotation axis, and the fluidity of the toner can be improved.

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

A first reference embodiment of the present invention will be described with reference to FIGS. The same parts as those described in FIGS. 1 to 6 are denoted by the same reference numerals, and description thereof will be omitted (the same applies to the following reference embodiments).

In the cleaning device 14A according to this reference embodiment, the brush roller 23 and the cleaning blade 24, cleaning is arranged a brush roller 23 on the upstream side along the traveling direction (arrow A direction) of the intermediate transfer belt 5 on the downstream side blade 24 is arranged, and the brush roller 23 is rotationally driven in a direction (arrow C direction) opposite to the direction along the traveling direction of the intermediate transfer belt 5.

Further, the cleaning device 14A according to this reference embodiment, the lower region of the cleaning blade 24, and surrounds the separation mechanism 26, a sealing case 35 that seals between the outer peripheral surface of the intermediate transfer belt 5 Yes. Sealing between the sealing case 35 and the outer peripheral surface of the intermediate transfer belt 5 is performed by a second outlet-side seal 36 whose tip is in contact with the outer peripheral surface of the intermediate transfer belt 5.

In such a configuration, the cleaning device 14A according to this reference embodiment, as in the cleaning device 14 of the embodiment described above, the outer periphery of the intermediate transfer belt 5 the contact portion 24a of the cleaning blade 24 by the moving mechanism 26 When separated from the surface, the contact portion 24a can be brought into contact with the brush 23b of the brush roller 23, and foreign matter adhering to the contact portion 24a can be cleaned with the brush 23b of the brush roller 23.

  Further, since the rotation direction of the brush roller 23 is opposite to the traveling direction of the intermediate transfer belt 5, the force when the brush 23 b of the brush roller 23 contacts the intermediate transfer belt 5 is increased. For this reason, it is possible to improve the performance of removing the foreign matter adhering to the outer peripheral surface of the intermediate transfer belt 5 by the brush roller 23, and the cleaning performance of the intermediate transfer belt 5 is combined with the action of removing the foreign matter by the cleaning blade 24. Can be increased.

  Further, since the sealing case 35 is provided, when the contact portion 24a is separated from the outer peripheral surface of the intermediate transfer belt 5 to clean the contact portion 24a, the outer peripheral surface or the contact portion of the intermediate transfer belt 5 is used. It is possible to prevent the foreign matter removed from 24a from scattering outside the cleaning device 14.

A second embodiment of the present invention will be described with reference to FIG. The cleaning apparatus 14B according to this reference embodiment, the protrusion 37 is provided in the case 25. The protrusion 37 is formed in a plate shape or a comb shape extending along the axial direction of the brush roller 23, and is positioned at a position where the brush 23 b contacts when the brush roller 23 rotates.

Further, the fan 38 is provided as a stream generating means in the cleaning device 14B according to this reference embodiment, the negative pressure state the casing 25 by generating an air flow directed from the case 25 within the outer case 25. A filter 39 is attached to the intake side of the fan 38 facing the case 25.

In such a configuration, the cleaning apparatus 14B according to this reference embodiment, as in the cleaning device 14,14A in the form of the embodiments described above, and the first reference, those of the cleaning blade 24 by the moving mechanism 26 When the contact portion 24 a is moved away from the outer peripheral surface of the intermediate transfer belt 5, the contact portion 24 a can be brought into contact with the brush 23 b of the brush roller 23, and the foreign matter adhering to the contact portion 24 a is removed from the brush roller 23. It can be cleaned with the brush 23b.

  Furthermore, when the brush 23b comes into contact with the protrusion 37 as the brush roller 23 rotates, the foreign matter attached to the brush 23b can be removed. As a result, the cleaning performance of the brush roller 23 when the brush 23b comes into contact with the outer peripheral surface of the intermediate transfer belt 5 or the contact portion 24a of the cleaning blade 24 can be improved, thereby improving the cleaning performance of the cleaning device 14. be able to.

  Further, the fan 38 is driven to generate an air flow from the inside of the case 25 to the outside of the case 25, whereby foreign matter peeled off from the outer peripheral surface of the intermediate transfer belt 5 and the contact portion 24 a of the cleaning blade 24 is put into the case 25. Inhalation is possible, and foreign matter removed from the outer peripheral surface of the intermediate transfer belt 5 and the contact portion 24a can be prevented from being scattered outside the case 25.

The color printer as an image forming apparatus implementation form of the present invention is a vertical sectional side view schematically showing. It is a vertical side view which shows a cleaning apparatus. It is a vertical side view which shows the cleaning apparatus which is cleaning the contact part of a cleaning blade with a brush roller. FIG. 3 is an explanatory diagram schematically showing the shape of a toner in order to explain a toner shape factor SF-1. FIG. 3 is an explanatory diagram schematically showing the shape of a toner in order to explain a toner shape factor SF-2. FIG. 3 is an explanatory diagram schematically illustrating a toner shape. It is a vertical side view which shows the cleaning apparatus of the 1st reference form of this invention. It is a vertical side view which shows the cleaning apparatus which cleans the contact part of the cleaning blade in a 1st reference form with a brush roller. It is a vertical side view which shows the cleaning apparatus of the 2nd reference form of this invention.

Explanation of symbols

5 Image carrier 14 Cleaning device 14A Cleaning device 14B Cleaning device 19 Transfer device 23 Brush roller 23b Brush 24 Cleaning blade 24a Contact portion 25 Case 26 Contact / separation mechanism 35 Sealing case 37 Contact portion 38 Airflow generating means P Transfer target member

Claims (4)

A brush roller which is driven to rotate in a direction along the traveling direction of the image carrier by bringing the brush into contact with the outer peripheral surface of the image carrier;
A cleaning blade disposed on the downstream side of the brush roller along the traveling direction of the image carrier, with a contact portion that contacts the outer peripheral surface of the image carrier facing the brush roller;
A case positioned at a position for receiving a foreign object scraped off from the outer peripheral surface of the image carrier by the cleaning blade having the contact portion in contact with the outer peripheral surface of the image carrier;
The cleaning blade is supported so as to be movable between a contact position where the contact portion contacts the outer peripheral surface of the image carrier and a separation position where the contact portion moves away from the outer peripheral surface of the image carrier. A contact / separation mechanism for moving the contact portion to a position where the brush roller of the brush roller that is rotationally driven in a direction along the traveling direction of the image carrier is moved to a position in contact with the brush as the blade is moved to the separation position; ,
A cleaning device comprising:   The cleaning device according to claim 1, wherein a material of the brush of the brush roller is a chemical fiber. An image carrier that is rotatably supported and carries a toner image on an outer peripheral surface;
A transfer device for transferring a toner image on the image carrier to a transfer member;
An image forming apparatus comprising: the cleaning device according to claim 1, wherein the outer peripheral surface of the image carrier after the toner image is transferred is cleaned.   The shape of the toner used for forming the toner image is defined by a major axis r1, a minor axis r2, and a thickness r3 (where r1 ≧ r2 ≧ r3), and the ratio between the major axis r1 and the minor axis r2. (R2 / r1) is set in the range of 0.5 to 1.0, and the ratio (r3 / r2) of the thickness r3 to the minor axis r2 is set in the range of 0.7 to 1.0. Item 4. The image forming apparatus according to Item 3.

Images