JP2009037015A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus for further reducing contamination in a charging roller and filming on a photoconductor generated due to a small particle diameter sphere toner. <P>SOLUTION: The image forming apparatus 100 comprises: a cleaning apparatus 15 having a means for causing a first blade 151 to abut on a surface of the photoconductor 11, removing a residue, and ejecting the removed object to the outside; a transferring apparatus 20 for transferring a visual image on the surface of the photoconductor 11 to a recording medium directly or after it is transferred to an intermediate transfer belt 21; and a fixing apparatus 25 for fixing a toner image on the recording medium. A second blade 152 abuts on the surface of the photoconductor 11 between the first blade 151 and a charger 12. The photoconductor 11 is controlled so as to move in the direction opposite to the direction during an imaging operation after an image forming operation is completed or before the image forming operation is initiated. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cleaning apparatus that is mounted on an electrophotographic image forming apparatus such as a copying machine, a printer, or a facsimile machine and that cleans the surface of an image carrier such as a photoconductor.

An electrophotographic image forming apparatus forms a toner image on a photoconductor as an image carrier, transfers the toner image to a transfer material or an intermediate transfer body, and then cleans the surface by a cleaning device to prepare for the next image. The operation is repeated to form an image. The cleaning device generally uses a brush roller or a blade and scrapes the surface of the photoreceptor. However, not only toner adheres to the surface of the photoreceptor, but also aggregates of toner additives, and those that are easily fixed, such as ozone and nitrogen oxide when bias is applied. Therefore, if the cleaning brush or cleaning blade is excessively pressed to scrape off the deposits effectively, the surface of the photoconductor may be damaged to cause an abnormal image, or the tip of the cleaning blade may be deformed, turned over, or entangled. Cause.
Further, in recent years, toners having a spherical shape and a small particle size have been made while high resolution and gradation images are required (see, for example, Patent Documents 1 to 6). However, when a toner having a spherical shape and a reduced particle size is used, there are some problems in cleaning on the photoreceptor after image formation.
The first is that wax that is added internally or externally to the toner to improve the releasability and inorganic fine particles to improve fluidity are detached from the toner and adhere to the photoreceptor. It is. As the toner becomes smaller in particle size, the content of these additives in the toner becomes higher than that in the conventional toner, so that the adhering substances on the photoreceptor tend to increase, and the adhering substances that are not removed. Causes minute filming on the surface of the photoreceptor. This filming is solidified by repeatedly receiving the charging energy under the charging device and gradually grows to cover the surface of the photoreceptor over time, affecting the charging uniformity and latent image reproducibility, and abnormal images such as streaks and image blurring. Will be generated. In order to solve this problem, for example, a means for removing the filming by bringing another blade in contact with the surface of the photoreceptor in addition to the cleaning blade between the cleaning device and the charging device has been disclosed and put into practical use. (For example, see Patent Document 7).

Secondly, in the cleaning method using a cleaning blade, spherical toner rotates between the blade and the photosensitive member and enters the gap, so that cleaning cannot be performed and cleaning failure occurs. The toner, toner additives, etc. that could not be stopped by this cleaning blade adhere to the charging device located downstream of the cleaning device and accumulate gradually, degrading the charging function and causing vertical streak-like abnormal images. Generally, a charging device having a long lifetime of an image forming apparatus has a charging cleaning unit. For this reason, the life of the charging cleaning means may become a bottleneck of the life of the image forming apparatus. To solve the problem that the small particle size spherical toner is difficult to clean, for example, a method for obtaining a small particle size toner having an irregular shape and a method for obtaining toner particles having irregularities on the surface are disclosed. (For example, see Patent Documents 8 and 9).
However, when both shapes are sufficiently cleanable, the resolution, which is a merit as a spherical toner, is also reduced. Therefore, the shape cannot be changed to a level that has a sufficient effect on cleaning properties.

In addition, as a first solution to this problem of slipping toner, in the apparatus having the two blades described above, the second blade can remove most of the toner that has passed through the first sheet. As a result, when the slipping-off toner and the scraped filming material that have been gradually removed between the first blade and the second blade accumulate over time, the filming scraping function of the second blade decreases, Further, slipping from the second blade also increases, which promotes charging roller contamination. For example, when the toner is clogged and overflows, the toner and additives staying as if the second blade is pushed up and broken pass through the second blade and stain the charging roller as it is, thereby causing an abnormal image.
As a charging method that uniformly charges the surface of the photoreceptor, in recent years, a charging roller formed as a roller with a conductive member is brought close to or in contact with the surface of the photoreceptor, and a voltage is applied between the charging roller and the photoreceptor. As a result, a charging roller system for charging the surface of the photoreceptor has been widely put into practical use because of the advantage of lowering ozone and lowering power. (For example, see Patent Document 10).
As a method of applying a bias to the charging roller, there is a method of superimposing a DC bias and a DC + AC bias. The method of applying only the DC bias has problems such as variation in charging potential due to minute charging gap fluctuation and discharge stability, and the DC + AC bias superimposing method is suitable for products that emphasize high image quality and high reliability. Conceivable.

However, a slight amount of toner or toner external additive that has passed through the cleaning blade tends to adhere to the surface of the charging roller in the charging region of the charging roller. In particular, the slipping toner remaining on the photoreceptor due to the AC amplitude movement of the charging bias flies to the charging roller side and is strongly adsorbed electrostatically.
In addition, slipping toner that has not been attracted to the charging roller and toner external additives may melt on the photosensitive member or increase adhesion to the surface of the photosensitive member when subjected to strong discharge energy due to charging bias, particularly AC bias. As a result, filming on the photoreceptor is likely to grow. As the above-mentioned contamination of the charging roller progresses, resistance unevenness occurs on the roller surface, mainly on vertical black stripes and black belts on the background, and when filming on the photoconductor progresses, latent image formation is inhibited and mainly the image area. This results in abnormal images such as vertical white stripes and white stripes.
To solve the above problems, a thin layer of lubricant is formed on the surface of the photoconductor to prevent the first detached toner additive from directly adhering to the surface of the photoconductor, thereby suppressing filming. A means for preventing the rotation of toner between the blade and the photosensitive member and suppressing the occurrence of defective cleaning is disclosed.
In this method, in order to reduce the thickness of the lubricant, the solid lubricant formed by a brush roller is pulverized and supplied to the surface of the photoreceptor, and the blade is brought into contact with the photoreceptor to form a uniform thin layer. Means for making it disclosed is disclosed.
In this means, for example, an apparatus is disclosed in which a lubricant supply brush is disposed in contact with the photosensitive member on the upstream side of the cleaning blade in the moving direction of the photosensitive member. (For example, see Patent Document 11).

  However, there is a problem that the lubricant and the photoconductor residue such as toner adhere to the brush surface and are difficult to separate, and the application performance of the lubricant is lowered. In addition, the brush scraping function may be reduced due to toner residue remaining in the brush and the application amount may be reduced. If the toner acts like an abrasive and the lubricant is scraped more than necessary, the application amount May be excessive. If the amount of coating is insufficient, filming or cleaning failure will occur.If the amount of coating is excessive, the lubricant layer on the photoconductor will be multi-layered, and the charging device will be soiled with the lubricant. Become. In order to solve this problem, for example, an image forming apparatus including a lubricant coating device that supplies a lubricant on a photosensitive member with a brush roller between a cleaning device and a charging device and thins the layer with a coating blade. It is disclosed. Among the means for making full use of the above-mentioned small particle size and spherical toner, it has been put into practical use as means for extending the life of the apparatus. (For example, see Patent Document 12). Filming is eliminated by the means for applying the lubricant, and the removal capability of the cleaning blade is remarkably improved, but a small amount of toner slips out. Since the amount is very small, dirt on the surface of the charging roller, for example, the charging roller is gradually accumulated, so it does not immediately cause an abnormal image like the above-mentioned cleaning failure. It causes abnormal images.

Japanese Patent Laid-Open No. 1-112253 JP-A-2-284158 Japanese Patent Laid-Open No. 3-181952 JP-A-4-162048 Japanese Patent Laid-Open No. 5-72808 Japanese Patent Laid-Open No. 9-15902 Japanese Patent No. 3889686 Japanese Patent Laid-Open No. 5-188642 JP 9-15903 A JP-A 63-149668 JP 2003-140518 A JP-A-2005-70276

  Accordingly, the present invention has been made in view of the above-described problems, and an object thereof is an image forming apparatus capable of reducing the occurrence of further charging roller contamination and filming on the photosensitive member in a small particle diameter, spherical toner. Is to provide.

The features of the present invention, which is a means for solving the above problems, are listed below.
The image forming apparatus of the present invention includes an image carrier that forms a latent image, a charging device that uniformly charges the surface of the image carrier, and the latent image is written on the charged image carrier surface based on image data. An exposure device, a developing device that supplies toner to the latent image formed on the surface of the image carrier and visualizes the image, and a first blade is brought into contact with the surface of the image carrier to remove the residue, and the removed product A cleaning device having means for discharging the toner to the outside of the apparatus, a transfer device for transferring the visible image on the surface of the image bearing member directly or onto the intermediate transfer member, and then transferring the toner image on the recording medium. In the image forming apparatus including the fixing device, the image forming apparatus causes the second blade to contact the surface of the image carrier between the first blade and the charging device, and after or after the image forming operation is completed. The direction opposite to that during the image forming operation of the image carrier before And controlling so as to move to.
The image forming apparatus according to the present invention is further characterized in that when the image carrier is moved in a direction opposite to that during the image forming operation, a unit for discharging the image carrier to the outside of the cleaning device is also operated.
In the image forming apparatus of the present invention, the cleaning device may further include a brush roller that removes residue by contacting and rotating the surface of the image carrier upstream of the first blade with respect to the image carrier movement direction. And the brush roller is simultaneously rotated when the image carrier is moved in a direction opposite to that during the image forming operation.
The image forming apparatus according to the present invention is further characterized in that the charging device uses an AC voltage as a charging bias.
The image forming apparatus of the present invention further includes a lubricant supply device that supplies a lubricant between the first blade and the second blade, and the second blade forms a lubricant layer on the image carrier. It is characterized by that.
Further, in the image forming apparatus of the present invention, the toner used in the developing device has a volume average particle diameter of 3 to 8 μm, and a ratio of the volume average particle diameter (Dv) to the number average particle diameter (Dn) ( Dv / Dn) is in the range of 1.00 to 1.40.
In the image forming apparatus of the present invention, it is further preferable that the toner used in the developing device 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. Features.
In the image forming apparatus of the present invention, the toner used in the developing device further includes at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent dispersed in an organic solvent. It is a toner obtained by crosslinking and / or stretching reaction of the toner material solution thus prepared in an aqueous medium.
The image forming apparatus of the present invention is further characterized in that the toner used in the developing device has a substantially spherical shape.
In the image forming apparatus of the present invention, the shape of the toner is defined by a major axis r1, a minor axis r2, and a thickness r3 (provided that r1 ≦ r2 ≦ r3), and the major axis r1. The ratio (r2 / r1) to the minor axis r2 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. It is characterized by being.

  As described above, according to the present invention, the first blade and the second blade are provided by providing two blades of the first blade and the second blade from the upstream side in the rotation direction of the image carrier, and performing reverse rotation of the photosensitive member. Therefore, it is possible to provide a device capable of discharging the toner and its additive accumulated between the two and the outside of the device and maintaining a good cleaning function over a long period of time. In particular, in an image forming apparatus that uses toner having a spherical shape and a reduced particle size for development, the toner passing through the cleaning blade and the additive desorbing from the toner surface are also effectively prevented from adhering to the photoreceptor and the charging device. can do. In addition, by installing the cleaning device of the present invention, it is possible to provide a process cartridge and an image forming apparatus that do not cause deterioration of image quality over a long period of time due to an excellent cleaning function.

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

A full-color image forming apparatus will be described as an example of the claims of the present invention. FIG. 1 is an overall schematic diagram of an image forming system in which four image forming units of this image forming apparatus are arranged in parallel. FIG. 2 is a schematic configuration diagram of one image forming unit.
A copying machine, which is an embodiment of an image forming apparatus according to the present invention, includes a document transport device (ADF) 500 that transports a document, a scanner unit 400 for reading a document, and a digital signal output from the scanner unit. The printer unit 300 includes an image processing unit that forms an image on a transfer sheet based on a digital signal output from the image processing unit. In the scanner unit 400, an image of a document placed on the document placement table is read by the color CCD 36 via an irradiation lamp, a mirror, and a lens, and the data is sent to the image processing unit. In the image processing unit, necessary processing is performed on the data, converted into an image signal, and sent to the printer unit 300.

  In the printer unit 300, four yellow, cyan, magenta, and black image forming units 10Y, 10C, 10M, and 10K are arranged in parallel, and one intermediate transfer belt 10 and one for the four image forming units 10 are provided. Two secondary transfer rollers 23 are provided. As described above, FIG. 2 shows a configuration of a yellow image forming unit 10Y as an example of the image forming unit 10 constituting the image forming apparatus 100. Unless otherwise specified, the other cyan image forming unit 10C, magenta image forming unit 10M, and black image forming unit 10K have the same configuration and operation. When the image forming operation is started, in the yellow image forming unit 10 </ b> Y, the surface of the photoreceptor 11, which is an electrostatic latent image carrier, is uniformly charged by the charging device 12. An electrostatic latent image of a yellow component image of a full-color original is formed on the charged photoreceptor 11 by exposure from an optical writing exposure device 20, and the electrostatic latent image is visualized with yellow toner by a yellow developing device 13Y. It becomes. Further, similar image forming operations are performed in the cyan image forming unit, the magenta image forming unit, and the black image forming unit 10 with a predetermined time difference, and toner images of cyan, magenta, and black colors are formed on the respective photoreceptors 11. Is done. In order to superimpose the toner images Y, C, M, and Bk formed on the photoreceptor 11 in each of the image forming units 10Y, 10C, 10M, and 10Bk as one full-color image on the intermediate transfer belt 21, this intermediate transfer is performed. On the back side of the belt 21, a transfer roller 14 is disposed at a position opposite to the photoconductor 11 of each image forming unit 10, and a predetermined transfer bias is applied to the transfer roller 14, whereby the toner image of each image forming unit 10 is transferred. The images are successively transferred onto the intermediate transfer belt 21 in a superimposed manner. Then, the toner image on the intermediate transfer belt 21 that has become one full-color image is transferred onto the transfer paper conveyed in time with the secondary transfer roller 23 to which a predetermined bias is applied, and then the transfer paper. Is transferred to the fixing device 25 and heated and pressurized to fix the toner image on the transfer paper and output a full color image. The transfer device includes a primary transfer roller 14, a secondary transfer roller 23, an intermediate transfer belt 21, a belt cleaning device 22, and the like.

The photoconductor 11 in each image forming unit 10 after being transferred to the intermediate transfer belt 21 has its surface potential eliminated by an unillustrated light neutralizing unit, and the transfer residual toner remaining on the photoconductor 11 is removed from the cleaning blade 151 of the cleaning device 15. , 152, and a series of image forming cycles such as charging by the charging device 12 described above are repeated. After the belt transfer, the surface of the photoconductor 11 is neutralized by an optical neutralization unit, and then a residue such as toner is removed by a cleaning device 15. The toner removed by the cleaning device 15 is transported to a waste toner storage tank through a waste toner transport path.
The charging device 12 is a contact charging method in which a charging member 12a disposed opposite to the photoconductor 11 is brought into contact and a predetermined DC voltage (DC) is applied to uniformly charge the surface of the photoconductor 11, and the charging member is elastic. A resin roller is used. A non-contact type potential sensor is installed at a position opposite to the photoreceptor surface between the exposure position and the development position on the photoreceptor surface in the rotation direction of the photoreceptor, and a charging bias is set so that a predetermined charging potential and a latent image potential are obtained. Adjust the value and exposure.

  Deposits such as toner and paper dust remaining on the surface of the intermediate transfer belt 21 after the transfer of the full color toner image onto the transfer paper are removed by a cleaning brush roller or a cleaning blade (not shown) of the intermediate transfer belt cleaning device 22. Then, it is transported to the waste toner container in the same manner as the above-described photoreceptor waste toner. A tension roller installed in a transfer unit including an intermediate transfer belt 21, a transfer roller, a transfer bias power source, a belt drive shaft, etc. applies or releases tension to the transfer belt by a cam mechanism, so that the transfer belt can form each image. The unit 10 can be changed between a state in contact with the photoconductor 11 and a state in which the unit 10 is separated. As a result, when the machine is operating, the photoconductor 11 of each image forming unit is in a contact state prior to rotation, and when the machine is stopped, the photoconductor 11 is separated from the photoconductor 11. After the toner image is transferred to the intermediate transfer belt, the surface of the photosensitive member is discharged by the light discharging unit, and the cleaning device 15 first (upstream position in the rotating direction of the photosensitive member in the cleaning unit) firstly rotates and counters the photosensitive member. The brush roller is rotated in contact with the toner to disturb the residual toner and adhered matter on the photosensitive member to weaken the adhesive force with the photosensitive member 11, and a blade made of a rubber elastic body is brought into contact with the photosensitive member 11 at a downstream position. Thus, the above-mentioned disturbed toner and deposits are removed.

Next, the cleaning device of the present invention will be described. The cleaning device 15 serves as a cleaning unit in order from the upstream side in the rotation direction of the photosensitive member, the brush roller 153 that removes residues such as toner after transfer, the first blade 151, and a recovery coil 155 that conveys the toner to the outside of the device. And a second blade 152 for removing film adsorbing on the photosensitive member.
For the first and second cleaning blades 151 and 152, rubbers such as fluorine rubber, silicone rubber, butyl rubber, butadiene rubber, isoprene rubber, and urethane rubber are preferably used. Of these, urethane rubber is particularly preferable.
In addition, since the second cleaning blade 152 is located downstream of the first cleaning blade 151, there may be no inclusion between the photoconductor 11 and the second cleaning blade 152, and the second cleaning blade 152 is increased due to an increase in frictional force. In order to prevent the blade 152 from being caught or scratched, the lubricating blade 152 has a two-layer structure of a blade base layer and a lubricant particle-containing layer on the photoreceptor. The manufacturing method for making the second cleaning blade 152 into a two-layer structure includes, for example, injecting a lubricant particle-containing layer before the blade base layer that is centrifugally molded in a centrifugal mold is completely cured. The layers can be formed integrally. Lubricant particles are not coated on the blade surface but dispersed in the blade, so that the lubricant particles do not peel off and can maintain a uniform lubricant application over time. Examples of the lubricant particles include fatty acid metal salts, silicone oils, fluorine resins, and the like, and these can be used alone or in admixture of two or more.

As the fatty acid metal salt, for example, myristic acid, palmitic acid, stearic acid, oleic acid and the like are preferable, and stearic acid is more preferable. Examples of the metal include lithium, magnesium, calcium, strontium, zinc, cadmium, aluminum, cerium, titanium, and iron. Of these, zinc stearate, magnesium stearate, zinc stearate, iron stearate and the like are preferred, and zinc stearate is most preferred.
Moreover, as the fluororesin fine particles, a modified body made of fluororesin, fluororesin acrylic resin, polyester resin or the like can be used. As the fluororesin, a fluororesin such as polytetrafluoroethylene, polytrifluoroethylene, and polyvinylidene fluoride, and a modified fluororesin obtained by highly fluorinating an acrylic resin, a polyimide resin, or the like can be used.
Specific examples of silicone oils include dimethyl silicone oil, phenylmethyl silicone oil, chlorophenyl silicone oil, fluorosilicone oil, fatty acid ester-modified silicone oil, methylhydrogen silicone oil, alkoxy group-containing silicone oil, amino-modified silicone oil, and carboxylic acid-modified. Examples include silicone oil and alcohol-modified silicone oil.

The lubricant particle-containing layer can contain an abrasive in a dispersed manner. By dispersing the abrasive with a certain width, it is possible to effectively remove adhered substances, filming substances, and the like on the photoconductor 11.
As the polishing agent, known ones such as cerium oxide and silica can be used. The average particle size of the abrasive is preferably 5 × 10 ⁻² μm or more and 100 μm or less. If the average particle diameter is less than 5 × 10 ⁻² μm, the particles are too fine, making it difficult to uniformly disperse in the rubber, or insufficient polishing power as a polishing blade cannot be obtained. On the other hand, if the average particle size exceeds 100 μm, the polishing force is too large, and the surface of the photoreceptor is damaged, which is not preferable. The content of the abrasive is preferably 0.5 wt% or more and 50 wt% or less. When the content of the abrasive particles is less than 0.5 wt%, sufficient polishing power as a polishing blade cannot be obtained. Further, if the content of the abrasive particles exceeds 50 wt%, the progress of wear on the surface of the photoreceptor is accelerated, which is not preferable.
The second cleaning blade 152 having such a two-layer structure is placed in contact with the photoreceptor 11 on the surface formed by the lubricant particle-containing layer.

FIG. 3 is a schematic diagram for explaining the functions of the first and second cleaning blades.
The first cleaning blade 151 mainly removes transfer residues on the photoreceptor 11 such as toner. The second cleaning blade 152 removes adhered substances, filming substances, and the like on the photoreceptor 11 whose main component is inorganic fine particles detached from the toner. Further, the toner leaking from the first cleaning blade is also removed.
The structure of the cleaning blades 151 and 152 includes a rubber blade and a holder sheet metal. The blade rubber is bonded to a metal holder sheet metal such as a galvanized steel plate with an adhesive such as hot melt. Further, both the first blade and the second blade are of a counter blade cleaning system in which the blade edge abuts in the counter direction with respect to the traveling direction of the photosensitive member 11.
A part of the toner or toner additive that has passed through the first blade 151 passes through the second blade 152, but most of the toner temporarily stays between the first blade 151 and the second blade 152. In a state where the photoreceptor 11 and the intermediate transfer belt 21 are separated from each other at a predetermined timing, for example, at the end of an initialization operation performed after the main power of the image forming apparatus 100 is turned on or after a paper jam processing operation, etc. Rotate in the opposite direction to the photoconductor rotation direction and stop.
As a result, the accumulated matter between the first blade 151 and the second blade 152 is pulled back upstream from the first blade 151, and is then cleaned again by the first blade 151 at the timing when the photosensitive member 11 rotates. At the same time, the cleaning brush 153 and the recovery coil 155 are also operated.
The reason why the intermediate transfer belt 21 and the photosensitive member 11 are reversely rotated is that the intermediate transfer belt 21 is in contact with the intermediate transfer belt 21 when the intermediate transfer belt 21 is operating. Since the rotation direction of the photoconductor 11 is reversed at the contact position, the rubbing force increases and an overload is applied to the respective drive motors. Further, it is possible to avoid the same problem even when the intermediate transfer belt 21 is stopped.

FIG. 4 is a schematic configuration diagram showing another embodiment of the image forming unit. The charging roller 12a is bonded to a roller member having a height difference of 0.030 mm with respect to the surface of the charging roller at a position in the non-image forming area at both ends thereof, so that the entire surface of the charging roller in the image forming area is 0.030. A gap with a tolerance of ± 0.015 mm is maintained, and a DC + alternating current (AC) bias is applied to charge the photoreceptor 11.
The AC bias condition is fixed at f = 2.5 kHz (> 7 times the photosensitive member linear velocity (353 mm / sec)) and adjusted to the predetermined voltage by adjusting the peak voltage Vpp and the DC bias value while comparing with the potential sensor detection value. The potential is controlled.
Next, a cleaning device having another configuration of the present invention will be described.
FIG. 5 is a schematic configuration diagram showing another embodiment of the image forming unit. The cleaning device 15 serves as a cleaning unit in order from the upstream side in the rotation direction of the photosensitive member, the brush roller 154 that removes residues such as toner after transfer, the first blade 151, and a recovery coil 155 that conveys the toner to the outside of the device. A second blade 152 for uniformly thinning the applied powder lubricant on the surface of the photoreceptor, and a lubricant application device 16 for supplying the second blade 152 with a lubricant. Yes. This lubricant application device includes a solid lubricant 162 that is solid molded, a brush roller 161 that contacts the solid lubricant, scrapes and supplies the lubricant to the photoreceptor 11, and a pressure member 164 that pressurizes the lubricant 162. Is provided. The solid lubricant 162 is urged toward the brush roller 161 by a pressure member 164 such as a plate spring or a compression spring. The brush roller 161 applies the lubricant 162 scraped off while rotating to the surface of the photoconductor 11.

As the solid lubricant 162, zinc stearate is used. This lubricant can be a dry solid hydrophobic lubricant. Besides zinc stearate, barium stearate, lead stearate, iron stearate, nickel stearate, cobalt stearate, stearic acid Those having a stearic acid group such as copper, strontium stearate, calcium stearate, cadmium stearate and magnesium stearate can be used. In addition, the same fatty acid groups zinc oleate, manganese oleate, iron oleate, cobalt oleate, lead oleate, magnesium oleate, copper oleate, and palmitic acid, zinc cobalt palmitate, copper palmitate, palmitate Magnesium acid, aluminum palmitate, and calcium palmitate may be used. In addition, fatty acids such as lead caprylate, lead caproate, zinc linolenate, cobalt linolenate, calcium linolenate and cadmium ricolinolenate, metal salts of fatty acids, and the like can also be used.
Like the first blade, the second blade is preferably a rubber such as fluorine rubber, silicone rubber, butyl rubber, butadiene rubber, isoprene rubber, or urethane rubber. Among these, urethane rubber is particularly preferable.
The first cleaning blade 151 mainly removes transfer residues on the photoreceptor 11 such as toner. The second cleaning blade 152 forms a thin layer of the lubricant 162 and removes the toner leaking from the first cleaning blade 152 at the same time. The cleaning blade is composed of a rubber blade and a holder sheet metal. The blade rubber is bonded to a metal holder sheet metal such as a galvanized steel plate with an adhesive such as hot melt. Further, both the first blade and the second blade are of a counter blade cleaning system in which the blade edge abuts in the counter direction with respect to the traveling direction of the photosensitive member 11.

  As in the first embodiment, a part of the toner or toner additive that has passed through the first blade 151 passes through the second blade 152, but most of the toner once stays between the first blade 151 and the second blade 152. To do. In a state where the photosensitive member 11 and the intermediate transfer belt 21 are separated from each other at a predetermined timing, for example, at the end of an initialization operation performed after the main power of the image forming apparatus 100 is turned on or after a paper jam processing operation, etc. Rotate in the opposite direction to the photoconductor rotation direction and stop. As a result, the accumulated matter between the first blade 151 and the second blade 152 is pulled back upstream from the first blade 151, and is then cleaned again by the first blade 151 at the timing when the photosensitive member 11 rotates. At the same time, the cleaning brush 153 and the recovery coil 155 are also operated.

Next, the toner used in the image forming apparatus according to the present invention will be described.
As the toner used in the developing device of the image forming apparatus according to the present invention, for example, 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. A toner material solution prepared by crosslinking and / or elongation reaction in an aqueous solvent can be used. Hereinafter, the constituent material and the manufacturing method of the toner will be described.

(Modified polyester)
The toner according to the present invention contains a modified polyester (i) as a binder resin. The modified polyester (i) refers to a state in which a bonding group other than an ester bond is present in the polyester resin, or resin components having different configurations are bonded to the polyester resin by a covalent bond, an ionic bond, or the like. Specifically, the polyester terminal is modified by introducing a functional group such as a carboxylic acid group or an isocyanate group that reacts with a hydroxyl group into the polyester terminal and further reacting with an active hydrogen-containing compound.
Examples of the modified polyester (i) include urea-modified polyester obtained by a reaction between a polyester prepolymer (A) having an isocyanate group and amines (B). As the polyester prepolymer (A) having an isocyanate group, a polyester having a polycondensate of a polyhydric alcohol (PO) and a polyvalent carboxylic acid (PC) and having an active hydrogen group is further added to a polyvalent isocyanate compound (PIC). And those reacted with. Examples of the active hydrogen group possessed by the polyester include a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group, and the like. Among these, an alcoholic hydroxyl group is preferable.

The urea-modified polyester is produced as follows.
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.

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 modified polyester (i) used in the present invention is produced by a one-shot method or a prepolymer method. The weight average molecular weight of the modified polyester (i) is usually 10,000 or more, preferably 20,000 to 10,000,000, more preferably 30,000 to 1,000,000. The peak molecular weight at this time is preferably 1000 to 10000. When the molecular weight is less than 1000, the elongation reaction hardly occurs, the elasticity of the toner is small, and as a result, the resistance to hot offset deteriorates. On the other hand, when it exceeds 10,000, the problem in production becomes high in the deterioration of fixability, particle formation and pulverization. The number average molecular weight of the modified polyester (i) is not particularly limited when the unmodified polyester (ii) described later is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. (I) When used alone, the number average molecular weight is usually 20000 or less, preferably 1000 to 10000, and more preferably 2000 to 8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color device are deteriorated.
In the crosslinking and / or extension reaction between the polyester prepolymer (A) and the amines (B) to obtain the modified polyester (i), a reaction terminator is used as necessary to adjust the molecular weight of the resulting urea-modified polyester. be able to. Examples of the reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).
In addition, the molecular weight of the produced | generated polymer can be measured using a gel permeation chromatography (GPC).

(Unmodified polyester)
In the present invention, not only the modified polyester (i) is used alone, but also the unmodified polyester (ii) can be contained as a binder resin component together with the (i). By using (ii) in combination, the low-temperature fixability and the gloss when used in a full-color device are improved, which is preferable to the single use. Examples of (ii) include polycondensates of a polyhydric alcohol (PO) and a polyvalent carboxylic acid (PC), which are the same as the polyester component (i), and preferred ones are also the same as (i). . Further, (ii) is not limited to unmodified polyester, but may be modified with a chemical bond other than a urea bond, for example, may be modified with a urethane bond. It is preferable that (i) and (ii) are at least partially compatible with each other in terms of low-temperature fixability and hot offset resistance. Therefore, the polyester component (i) and (ii) preferably have similar compositions. In the case of containing (ii), the weight ratio of (i) to (ii) is usually 5/95 to 80/20, preferably 5/95 to 30/70, more preferably 5/95 to 25/75, Particularly preferred is 7/93 to 20/80. If the weight ratio of (i) is less than 5%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

The peak molecular weight of (ii) is 1000-10000 normally, Preferably it is 2000-8000, More preferably, it is 2000-5000. If it is less than 1000, heat-resistant storage stability will deteriorate, and if it exceeds 10,000, low-temperature fixability will deteriorate. The hydroxyl value of (ii) is preferably 5 or more, more preferably 10 to 120, and particularly preferably 20 to 80. If it is less than 5, it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. As for the acid value of (ii), 1-5 are preferable, More preferably, it is 2-4. Since a high acid value wax is used as the wax, the low acid value binder leads to electrification and high volume resistance, so that it is easy to match the toner used for the two-component developer.
The glass transition point (Tg) of the binder resin is usually 35 to 70 ° C, preferably 55 to 65 ° C. If it is less than 35 ° C., the heat resistant storage stability of the toner is deteriorated, and if it exceeds 70 ° C., the low-temperature fixability is insufficient. Since the urea-modified polyester is likely to be present on the surface of the obtained toner base particles, the toner of the present invention tends to have good heat storage stability even when the glass transition point is low, as compared with known polyester-based toners. Show.
The glass transition point (Tg) can be measured using a Rigaku THRMOFLEX TG8110 manufactured by Rigaku Corporation with a temperature increase rate of 10 ° C./min. The method for measuring the glass transition point is outlined below.
As a glass transition point measuring device, a TG-DSC system TAS-100 manufactured by Rigaku Corporation can be used. Specifically, about 10 mg of a sample is placed in an aluminum sample container, placed on a holder unit, and set in an electric furnace. Next, after heating the temperature of the electric furnace from room temperature to 150 ° C. at a heating rate of 10 ° C./min, the sample was allowed to stand at 150 ° C. for 10 minutes, and then the sample was cooled to room temperature and allowed to stand for 10 minutes. Then, DSC measurement was performed again by heating to 150 ° C. at a temperature rising rate of 10 ° C./min. The value of the glass transition point (Tg) was calculated from the contact point between the tangent line of the endothermic curve near the Tg and the base line using the analysis system in the TAS-100 system.

(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 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 salt or compound, tungsten simple substance or compound, fluorine activator, salicylic acid metal salt, metal salt of salicylic acid derivative, and the like. 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 the 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. The amount is preferably 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 flowability of the developer 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, and 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 ~2μm, it is particularly preferably 5 × ¹⁰ -3 ~0.5μm. 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, quartz sand, clay, mica, wollastonite, diatomaceous earth. Examples include soil, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. Among these, as the fluidity imparting agent, it is preferable to use hydrophobic silica fine particles and hydrophobic titanium oxide fine particles in combination. In particular, when stirring and mixing are performed using particles having an average particle diameter of 5 × 10 ⁻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 to obtain a good image quality that does not cause the release of the fluidity imparting agent from the toner and does not generate firefly, etc., and further reduces the residual toner. It is done.
Titanium oxide fine particles are excellent in environmental stability and image density stability, but have a tendency to deteriorate the charge rise characteristics. Therefore, if the amount of titanium oxide fine particles added is larger than the amount of silica fine particles added, this side effect is affected. It can be considered large. However, when the added amount of the hydrophobic silica fine particles and the hydrophobic titanium oxide fine particles is in the range of 0.3 to 1.5 wt%, the charge rising characteristics are not greatly impaired, and the desired charge rising characteristics can be obtained, that is, repeated copying. Stable image quality can be obtained even if

Next, a toner manufacturing method will be described. Here, although a preferable manufacturing method is shown, it is not limited to this.
(Toner production method)
1) A toner material solution is prepared by dispersing a colorant, unmodified polyester, a polyester prepolymer having an isocyanate group, and a release agent in an organic solvent.
The organic solvent is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal after toner base particle formation. Specifically, toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, Methyl isobutyl ketone and the like can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform, and carbon tetrachloride are preferable. The usage-amount of an organic solvent is 0-300 weight part normally with respect to 100 weight part of polyester prepolymers, Preferably it is 0-100 weight part, More preferably, it is 25-70 weight part.

2) The toner material liquid is emulsified in an aqueous medium in the presence of a surfactant and resin fine particles.
The aqueous medium may be water alone or an organic solvent such as alcohol (methanol, isopropyl alcohol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.). It may be included.
The amount of the aqueous medium used relative to 100 parts by weight of the toner material liquid is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight. If the amount is less than 50 parts by weight, the dispersion state of the toner material liquid is poor and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 20000 parts by weight, it is not economical.
Further, in order to improve the dispersion in the aqueous medium, a dispersant such as a surfactant and resin fine particles is appropriately added.
As surfactants, anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt types such as imidazoline, Quaternary ammonium salt type cationic surfactants such as alkyltrimethylammonium 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.), Xtop EF-102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fgentent F-100, F150 (manufactured by Neos).

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 cause a reaction with the polyester prepolymer (A) having an isocyanate group.
This reaction involves molecular chain crosslinking and / or elongation. The reaction time is selected depending on the reactivity 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 used in the present invention preferably has a volume average particle diameter (Dv) of 3.0 to 8.0 μm, and the ratio (Dv) of the volume average particle diameter (Dv) to the number average particle diameter (Dn). / Dn) is preferably 1.00 to 1.40. By using a toner having such a particle size and particle size distribution, it is excellent in heat-resistant storage stability, low-temperature fixability, and hot offset resistance, and particularly when used in a full-color copying machine, etc. Sex is obtained.
In general, the smaller the particle size of the toner, the more advantageous it is to obtain a high-resolution and high-quality image, but conversely, it is disadvantageous for transferability and cleaning properties. Become. Further, when the volume average particle size is less than 3.0 μm, when used as a two-component developer, the toner is fused to the surface of the magnetic carrier by long-term stirring in the developing device, and the charging ability of the magnetic carrier When the toner is used as a one-component developer, the toner filming on the developing roller or the toner fusing to a member such as a blade for thinning the toner may occur. Is likely to occur. On the other hand, when the volume average particle size of the toner exceeds 8.0 μm, it becomes difficult to obtain a high-resolution and high-quality image, and when the toner balance is made in the developer, the toner particle size In many cases, the fluctuation becomes large.
On the other hand, if Dv / Dn exceeds 1.40, the charge amount distribution becomes wide and the resolving power decreases, which is not preferable. The ratio Dv / Dn between the volume average particle diameter Dv and the number average diameter (Dn) of the toner obtained as described above mainly includes, for example, the water phase viscosity, the oil phase viscosity, the characteristics of the resin fine particles, the addition amount, and the like. It can be controlled by adjusting. Further, Dv and Dn can be controlled by adjusting, for example, the characteristics of resin fine particles, the addition amount, and the like.
The average particle size and particle size distribution of the toner can be measured using a Coulter Counter TA-II or Coulter Multisizer (manufactured by Coulter, Inc.) as a measuring device.
The measuring method is as follows. First, 0.1 to 5 ml of a surfactant (preferably alkyl benzene sulfonate) is added as a dispersant to 100 to 150 ml of an electrolytic aqueous solution. Here, the electrolytic solution was prepared by preparing approximately 1% NaCl aqueous solution using primary sodium chloride, and ISOTON R-II (manufactured by Coulter Scientific Japan) was used. Further, 2 to 20 mg of a measurement sample was added thereto, suspended in an electrolytic solution, and subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes. Using the measurement apparatus, the volume and number of toner particles in the sample were measured for each channel using a 100 μm aperture as the aperture, and the volume distribution and number distribution of the toner were calculated.
In addition, as a channel, it is 2.00-2.52 micrometer; 2.52-3.17 micrometer; 3.17-4.00 micrometer; 4.00-5.04 micrometer; 5.04-6.35 micrometer; 6.35- 8.00 to 10.08 μm; 10.08 to 12.70 μm; 12.70 to 16.00 μm; 16.00 to 20.20 μm; 20.20 to 25.40 μm; 25.40 to 32. 00 μm; 13 channels from 32.00 to 40.30 μm were used.

(Average circularity)
The average circularity of the toner used in the present invention is preferably 0.95 or more. By using a toner having an average circularity of 0.95 or more, dot reproducibility is excellent and a high transfer rate can be obtained. When the average circularity is less than 0.95, the toner is separated from the spherical shape, the dot reproducibility is deteriorated, and the number of contact points with the photoreceptor 11 as a latent image carrier increases, so that the releasability is improved. The transfer rate decreases.
As described above, even when a toner having a high average circularity and a nearly spherical shape is used, the image forming apparatus of the present invention can exhibit good blade cleaning performance.
The average circularity of the toner particles is a value obtained by optically detecting the particles and dividing by the circumference of an equivalent circle having the same projected area. Specifically, the measurement is performed using a flow particle image analyzer (FPIA-2100; manufactured by Sysmex Corporation). In a predetermined container, 100 to 150 mL of water from which impure solids are removed in advance is added, 0.1 to 0.5 mL of a surfactant is added as a dispersant, and about 0.1 to 9.5 g of a measurement sample is further added. The suspension in which the sample is dispersed is subjected to dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the concentration and dispersion of the dispersion are set to 3,000 to 10,000 / μL, and the shape and distribution of the toner are measured.

The toner used in the present invention is preferably a toner having a shape factor SF-1 in the range of 100 to 180 and SF-2 in the range of 100 to 180. SF-1 is more preferably 110 to 170, more preferably 120 to 160, and particularly preferably 130 to 150. SF-2 is more preferably 110 to 170, more preferably 120 to 160, and particularly preferably 130 to 150.
FIG. 6 is a diagram schematically showing the shape of the toner in order to explain the shape factor SF-1 and the shape factor SF-2. In FIG. 6, (a) is a diagram for explaining the shape factor SF-1, and (b) is a diagram for explaining the shape factor SF-2.
The shape factor SF-1 indicates the ratio of the roundness of the toner shape, and the square of the maximum length MXLNG of the shape formed by projecting the toner onto the two-dimensional plane represented by the following formula (1) is represented by the graphic area. Divide by AREA and multiply by 100π / 4.
The shape factor SF-2 indicates the ratio of the unevenness of the toner shape, and is expressed by the square of the perimeter PERI of the figure formed by projecting the toner on the two-dimensional plane represented by the following formula (2). It is a value obtained by dividing the figure area AREA and multiplying by 100 / 4π.
SF-1 = {(MXLNG) ² / AREA} × (100π / 4) (1)
SF-2 = {(PERI) ² / AREA} × (100π / 4) Expression (2)
When the value of SF-1 is 100, the shape of the toner becomes a true sphere, and becomes larger as the value of SF-1 increases. Further, when the value of SF-2 is 100, unevenness does not exist on the toner surface, and as the value of SF-2 increases, the unevenness of the toner surface becomes more prominent.

The shape factor SF-1 is 100 images of toner particles magnified by a magnification of 500 using an electron microscope (for example, FE-SEM (S-800) manufactured by Hitachi, Ltd., and the same applies hereinafter). The image information is sampled randomly, and the image information is introduced into the image analysis apparatus via the interface and analyzed, and is a value obtained from the equation (1). As an image analysis apparatus, for example, Nexus NEW CUBE ver. 2.5 (manufactured by NEXUS), Luzex III (manufactured by Nicole) and the like, and so on.
The shape factor SF-2 is obtained by randomly sampling 50 toner particle images magnified to a magnification of 3500 times using an electron microscope, introducing the image information into an image analysis apparatus via an interface, and performing analysis. It is a value obtained from 2).
When the shape factors SF-1 and SF-2 are both close to 100 and the shape of the toner is close to a true sphere, the contact between the toner and the toner or the toner and the image carrier becomes a point contact. Accordingly, the fluidity is increased and the adhesion between the toner and the image carrier is also weakened, and the transfer rate is increased. The dot reproducibility is also improved. On the other hand, when the toner shape factors SF-1 and SF-2 are large to some extent, the margin for cleaning increases, and there is no problem such as defective cleaning. Therefore, it is preferable that the shape factors SF-1 and SF-2 are in the range of 100 to 180 as a range in which the image quality is not deteriorated from the balance between the two.

Further, the shape of the toner used in the present invention is substantially spherical, and can be represented by the following shape rule.
FIG. 7 is a diagram schematically showing the shape of the toner applied to the present invention. In FIG. 7, 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 major axis and a minor axis. Ratio (r2 / r1) (see FIG. 7B) is 0.5 to 1.0, and the ratio of thickness to minor axis (r3 / r2) (see FIG. 7C) is 0.7 to 1.0. It is preferable to be in the range of 1.0. When the ratio of the major axis to the minor axis (r2 / r1) is less than 0.5, the dot reproducibility and transfer efficiency are inferior because of being away from the true spherical shape, and high quality image quality cannot be obtained. On the other hand, if the ratio of thickness to minor axis (r3 / r2) is less than 0.7, the shape is close to a flat shape, and a high transfer rate like a spherical toner cannot be obtained. In particular, when the ratio of the thickness to the minor axis (r3 / r2) is 1.0, the rotating body has a major axis as a rotation axis, and the fluidity of the toner can be improved.
In addition, r1, r2, r3 can be measured by the following method, for example.
That is, the toner is uniformly dispersed and adhered on a smooth measurement surface, and 100 particles of the toner are magnified 500 times by a color laser microscope (VK-8500: manufactured by Keyence Corporation). The major axis r1 (μm), the minor axis r2 (μm), and the thickness r3 (μm) of the toner particles can be measured and obtained from their arithmetic average values.

1 is a schematic configuration diagram of an image forming apparatus according to an exemplary embodiment. 1 is a schematic diagram illustrating a configuration of an image forming unit applied to the present invention. It is a schematic diagram for demonstrating the function of a 1st and 2nd cleaning blade. It is the structure schematic which shows other embodiment in this image creation unit. It is the structure schematic which shows other embodiment in this image creation unit. FIG. 4 is a diagram schematically illustrating the shape of a toner for explaining the shape factor SF-1 and the shape factor SF-2. FIG. 3 is a diagram schematically illustrating the shape of a toner applied to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Image forming apparatus 200 Paper feeder 300 Image forming main body 400 Scanner part 500 Automatic document feeder (ADF)

DESCRIPTION OF SYMBOLS 10 Image forming unit 11 Photoconductor 12 Charging device 13 Developing device 14 Transfer roller 15 Cleaning device 151 1st blade 152 2nd blade 153 Cleaning brush 154 Flitter 155 Recovery coil 16 Lubricant coating device 161 Lubricant application brush roller 162 Solid lubricant 164 Pressure member 20 Exposure device 21 Intermediate transfer belt 22 Belt cleaning device 23 Secondary transfer roller 24 Conveying belt 25 Fixing device 30 Reading CCD
40 Paper cassette 42 Pickup roller 45 Transport roller 49 Registration roller

Claims (10)

An image carrier for forming a latent image;
A charging device for uniformly charging the surface of the image carrier;
An exposure device that exposes a charged image carrier surface based on image data and writes a latent image; and
A developing device that supplies toner to the latent image formed on the surface of the image carrier to make a visible image;
A cleaning device having means for removing the residue by contacting the first blade against the surface of the image carrier and discharging the removed material out of the device;
A transfer device for transferring a visible image on the surface of the image bearing member directly or onto an intermediate transfer member and then transferring it to a recording medium;
An image forming apparatus including a fixing device that fixes a toner image on a recording medium.
The image forming apparatus has a second surface on the surface of the image carrier between the first blade and the charging device.
The image forming apparatus is configured to control the image carrier to move in a direction opposite to that during the image forming operation after the image forming operation is completed or before the image forming operation is completed. The image forming apparatus according to claim 1,
An image forming apparatus, wherein when the image carrier is moved in a direction opposite to that during the image forming operation, a unit for discharging the image carrier to the outside of the cleaning device is also operated. The image forming apparatus according to claim 1,
The cleaning device has a brush roller that removes the residue by contacting and rotating the surface of the image carrier upstream of the first blade with respect to the moving direction of the image carrier,
An image forming apparatus, wherein when the image carrier is moved in a direction opposite to that during the image forming operation, the brush roller is simultaneously rotated. The image forming apparatus according to claim 1,
The charging device uses an AC voltage as a charging bias. The image forming apparatus according to claim 1,
An image forming apparatus comprising a lubricant supply device for supplying a lubricant between a first blade and a second blade, and forming a lubricant layer on the image carrier with the second blade. The image forming apparatus according to claim 1,
The toner used in the developing device 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) of 1.00 to 1.40. An image forming apparatus characterized by being in the range. The image forming apparatus according to claim 1,
The image forming apparatus, wherein the toner used in the developing device 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. The image forming apparatus according to claim 1,
The toner used in the developing device is obtained by crosslinking a toner material liquid in which at least a polyester prepolymer having a functional group containing a nitrogen atom, polyester, a colorant, and a release agent is dispersed in an organic solvent in an aqueous medium. And / or a toner obtained by an extension reaction. The image forming apparatus according to claim 1,
The toner used in the developing device has a substantially spherical shape. The image forming apparatus according to claim 1,
The shape of the toner used in the developing device 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 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. Forming equipment.

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