JP2008046301A - Image forming device and processing cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device incorporating a lubricant applying device which can spread the lubricant thinner and more evenly in the width direction on the photoreceptor and improve the transfer performance and cleaning performance, and also provide a processing cartridge thereof. <P>SOLUTION: The lubricant application means in this image forming device is composed of a first lubricant applicating device 17 disposed upstream the cleaning blade 15a in the revolution direction X of the photoreceptor, and a second lubricant applicator 18 disposed downstream. The first lubricant applicating device 17 works also as a cleaning brush roller 15b to apply the lubricant to the photoreceptor drum 11. The second lubricant applicating device 18 has a solid lubricant 18b, a brush-like roller 18a turning in contact with the solid lubricant 18b to scrape the lubricant off to apply to the surface of the photoreceptor drum 11, and an application blade 18c to spread the supplied lubricant thin on the photoreceptor drum 11. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus and a process cartridge, and more particularly to an image forming apparatus and a process cartridge provided with a lubricant applying device for applying a lubricant to the surface of a photoreceptor.

  In recent years, color image forming apparatuses using an electrophotographic method have become widespread, and further high definition of printed images has been demanded in connection with the fact that digitized images can be easily obtained. . In consideration of higher resolution and gradation of an image, in order to form a high-definition image, studies have been made on reducing the particle size and spheroidizing of toner.

  The toner having a small particle size and spherical shape is suitable for obtaining a high-definition image because it is faithfully transferred. However, since the spherical toner is easy to roll, a cleaning blade and a photosensitive member in a cleaning device are used. , The toner is not cleaned and remains on the photoconductor, and is scattered in the apparatus and contaminates the charging roller and the like, which may cause abnormal images such as black spots and ground fog on the image.

  For this purpose, as a cleaning means for removing the toner from the photosensitive drum, a cleaning blade, and a brush roller disposed in contact with the photosensitive drum on the upstream side of the cleaning blade in the rotation direction of the photosensitive drum, Has been proposed (see, for example, Patent Document 1).

In this cleaning device, the brush roller is rotated and scraped from the lubricant of the rod-shaped molded body that is in sliding contact with the brush roller, and the lubricant thus scraped is applied to the surface of the photosensitive drum, and then the photosensitive drum. Improved toner releasability from the surface of the drum, facilitating the separation of the toner from the surface of the photosensitive drum by rubbing the cleaning blade, and improved cleaning performance when using spherical small-diameter toner It is something to be made.
JP 2003-140518 A

  However, the cleaning device described in Patent Document 1 has a problem in that a uniform lubricant application state cannot be achieved in the width direction of the photoreceptor, and an abnormal image cannot be prevented.

  The present invention has been made in consideration of the above circumstances, and includes a lubricant application device in which the lubricant is thinned more uniformly in the width direction of the photoreceptor, and transfer performance and cleaning performance can be improved. An object is to provide an image forming apparatus and a process cartridge.

  In order to achieve this object, the invention according to claim 1 is based on a photoconductor for forming a latent image, a charging device for uniformly charging the surface of the photoconductor, and image data on the charged surface of the photoconductor. An exposure device that exposes and writes a latent image, a developing device that supplies toner to the latent image formed on the surface of the photoconductor to make it visible, and a cleaning device that cleans the surface of the photoconductor In the forming apparatus, a lubricant application device for applying a lubricant to the surface of the photoconductor is provided at a plurality of locations on the outer periphery of the photoconductor.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the cleaning device includes a cleaning blade that removes transfer residual toner remaining on the surface of the photoreceptor, and is disposed at the plurality of positions. The lubricant applying device includes a first lubricant applying device disposed on the upstream side of the cleaning blade and a second lubricant applying device disposed on the downstream side of the cleaning blade. .

  According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the plurality of lubricant application devices vary the amount of lubricant applied to the surface of the photoreceptor. It is characterized by.

  According to a fourth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the plurality of lubricant application devices are made of a lubricant material applied to the surface of the photoreceptor. It is characterized by making each different.

  According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects, the plurality of lubricant application devices include brushes for supplying a lubricant to the surface of the photoreceptor. And a coating blade for leveling the lubricant supplied by the lubricant supply roller on the photoconductor.

  The invention according to claim 6 is the image forming apparatus according to any one of claims 1 to 5, wherein the lubricant is a fatty acid metal salt, and the metal of the fatty acid metal salt is zinc, At least one metal selected from iron, calcium, aluminum, lithium, magnesium, strontium, barium, cerium, titanium, zirconium, lead, manganese, and the fatty acid of the fatty acid metal salt is lauric acid, stearin It is at least one fatty acid selected from acids, palmitic acid, myristic acid and oleic acid.

  According to a seventh aspect of the present invention, in the image forming apparatus according to any one of the first to sixth aspects, the charging device includes a charging member that is not in contact with the photoconductor, and the charging member has a direct current. A bias voltage in which AC and AC are superimposed is applied.

  The invention according to claim 8 is the image forming apparatus according to any one of claims 1 to 7, wherein the toner has a weight average particle diameter of 3 to 8 μm and a weight average particle diameter (Dv). The ratio (Dv / Dn) to the number average particle diameter (Dn) is in the range of 1.00 to 1.40.

  The invention according to claim 9 is the image forming apparatus according to any one of claims 1 to 8, wherein the toner particles have an average circularity in a range of 0.93 to 1.00. It is characterized by.

The image forming apparatus according to any one of claims 1 to 9, wherein the toner particles have a shape factor SF-1 in the range of 100 to 180, and the shape factor. SF-2 is in the range of 100 to 180 (however, the shape factors SF-1 and SF-2 are the maximum length (MXLNG) of the shape formed by projecting toner particles on a two-dimensional plane, figure When the area (AREA) and the perimeter of the figure (PERI) are used, the following expressions (1) and (2) are satisfied.
SF-1 = {(MXLNG) ² / AREA} × (100π / 4) (1)
SF-2 = {(PERI) ² / AREA} × (100π / 4) (2)

The invention according to claim 11 is the image forming apparatus according to any one of claims 1 to 10, wherein the toner has an average primary particle size of 50 to 500 nm and a bulk density of 0.3 g / cm. ^It contains ³ or more fine particles.

  The invention according to claim 12 is the image forming apparatus according to any one of claims 1 to 11, wherein the toner has a glass transition temperature of 35 to 70 ° C and an outflow start temperature of 90 to 115 ° C. It contains a binder resin.

  The invention according to claim 13 is the image forming apparatus according to any one of claims 1 to 12, wherein the toner is a polyester prepolymer, polyester, or colorant having a functional group containing at least a nitrogen atom. The composition is obtained by crosslinking and / or extending a toner material liquid in which a release agent is dispersed in an organic solvent in an aqueous medium.

  According to a fourteenth aspect of the present invention, a photosensitive member carrying a latent image and a cleaning device for cleaning residual toner on the photosensitive member are at least integrally configured and detachably attached to the main body of the image forming apparatus. In the process cartridge, a lubricant application device for applying a lubricant to the surface of the photoconductor is integrally provided with the photoconductor and a cleaning device at a plurality of locations on the outer periphery of the photoconductor.

  According to a fifteenth aspect of the present invention, in the process cartridge according to the fourteenth aspect, the cleaning device includes a cleaning blade that removes transfer residual toner remaining on the surface of the photoconductor, and is disposed at the plurality of positions. The lubricant applying device includes a first lubricant applying device disposed on the upstream side of the cleaning blade and a second lubricant applying device disposed on the downstream side of the cleaning blade. .

  The invention described in claim 16 is the process cartridge according to claim 14 or 15, wherein the plurality of lubricant applying devices vary the amount of lubricant applied to the surface of the photoreceptor. Features.

  The invention described in claim 17 is the process cartridge according to any one of claims 14 to 16, wherein the plurality of lubricant application devices respectively apply a lubricant material applied to the surface of the photoreceptor. It is characterized by making it different.

  The invention according to claim 18 is the process cartridge according to any one of claims 14 to 17, wherein the plurality of lubricant application devices have brushes for supplying a lubricant to the surface of the photoreceptor. A lubricant supply roller is provided, and an application blade for leveling the lubricant supplied by the supply roller on the photoreceptor is provided.

  According to the present invention, by adopting the above-described configuration, the lubricant is thinned more uniformly in the width direction of the photoconductor, and image formation including a lubricant coating device that can improve transfer performance and cleaning performance. Apparatus and process cartridges can be provided.

  In the present invention, as a result of studying the point that the uniform lubricant application state in the width direction of the photoconductor cannot be achieved with the device described in Patent Document 1, the case where toner is interposed between the developing device and the photoconductor Between the toner and the photosensitive member, and when the toner is interposed between the transfer means and the photosensitive member, the toner and the photosensitive member are rubbed, and further, the toner is transferred between the cleaning blade of the cleaning device and the photosensitive member. It has been found that one reason is that the lubricant layer formed on the surface of the photoreceptor is scraped off due to the rubbing between the toner and the photoreceptor when the residual toner is present.

  As a result, the lubricant is applied with unevenness partially in the width direction of the photosensitive member, resulting in a problem that uniform transfer performance and good cleaning performance cannot be obtained. Furthermore, the cleaning performance deteriorates and the charging means partially develops, and the uniform charging performance is also impaired.

  Based on the results of this study, as a result of further studies, after the lubricant layer has been scraped off by rubbing between the toner and the photoreceptor, the lubricant layer should be replenished and repaired as soon as possible. For example, it has become possible to always maintain a uniform lubricant layer in the width direction of the photoreceptor, and to investigate that transfer performance and cleaning performance are improved.

  Specifically, there are a plurality of photosensitive members around the photosensitive member, such as before and after the cleaning blade of the cleaning device, and before and after the transfer device and the developing device, in which the lubricant layer is likely to be scraped by the friction between the toner and the photosensitive member. By installing the lubricant application device, when the lubricant layer is scraped by the rubbing between the toner and the photoconductor, the lubricant is applied to the photoconductor from the lubricant applicator immediately after the occurrence. It was clarified that the above problem can be solved by repairing the scraped portion of the agent layer.

  However, installing a large number of lubricant application devices is not only expensive, but also leads to an increase in the size of the device, so that the lubricant layer is likely to be scraped off due to friction between the toner and the photoreceptor. A lubricant application device is disposed before and after the cleaning blade of the cleaning device to immediately repair the abrasion of the lubricant layer caused by the rubbing between the toner and the photoconductor on the cleaning blade. For the abrasion of the lubricant layer due to the friction between the toner and the photoconductor generated in the transfer device or the developing device, a lubricant is applied immediately before the cleaning blade of the cleaning device contacts the photoconductor. The lubricant layer scraping due to the friction between the toner and the photoconductor generated in the transfer device or the developing device is repaired.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration of an image forming apparatus according to an embodiment of the present invention. The image forming apparatus according to this embodiment includes four image forming units 1Y, 1M, 1C, and 1K for forming images of each color of yellow (Y), magenta (M), cyan (C), and black (K). I have. In the following description, yellow, magenta, cyan, and black are indicated by Y, M, C, and K, respectively. The color order of Y, M, C, and K is not limited to that shown in FIG.

  The image forming units 1Y, 1M, 1C, and 1K include drum-shaped photoconductors 11Y, 11M, 11C, and 11K as image carriers that are rotationally driven by a motor (not shown), and the photoconductors 11Y, 11M, respectively. , 11C, and 11K, photoreceptor units 2Y, 2M, 2C, and 2K, which will be described later, and developing devices 10Y, 10M, 10C, and 10K are disposed. The image forming units 1Y, 1M, 1C, and 1K are arranged such that the rotation axes of the photoconductors 11Y, 11M, 11C, and 11K are parallel to each other and a predetermined pitch in the moving direction B of the transfer paper 100. It is set to arrange in.

  Above the image forming units 1Y, 1M, 1C, and 1K, a light source, a polygon mirror, an f-θ lens, a reflection mirror, and the like are provided, and on the surface of each photosensitive drum 11Y, 11M, 11C, and 11K based on image data. An optical writing unit 3 that irradiates while scanning with laser light L carries a transfer paper 100 below, and transfers toner images from the photoreceptors 11Y, 11M, 11C, and 11K with transfer rolls 67Y, 67M, 67C, and 67K. A transfer portion of each image forming unit to be transferred is provided.

  In addition, an endless transfer conveyance belt 60 that conveys the transfer portion so as to pass through the transfer portion is stretched around the drive roller 62 and guide rollers 61, 63, 64, 65, and 66 in the direction of the arrow A. A transfer unit 6 is disposed as a belt driving device for driving. A cleaning device 85 including a brush roller and a cleaning blade is disposed on the outer peripheral surface of the transfer conveyance belt 60 so as to come into contact therewith. The cleaning device 85 removes foreign matters such as toner adhering to the transfer / conveying belt 60.

  On the side of the transfer unit 6, a belt fixing type fixing unit 7, a paper discharge tray 8, and the like are provided. Under the image forming apparatus, paper feed cassettes 4a and 4b on which transfer paper 100 is placed are provided. A manual tray MF that manually feeds paper from the side of the image forming apparatus is also provided. In addition, a toner replenishing container TC is provided, and a waste toner bottle, a duplex / reversing unit, a power supply unit, and the like (not shown) are also provided in a space S indicated by a two-dot chain line.

  The developing devices 10Y, 10M, 10C, and 10K as developing means are all of the same configuration, and are two-component developing type developing devices that differ only in the color of the toner to be used. Contained. The developing devices 10Y, 10M, 10C, and 10K include a developing roller that faces the photosensitive drum 11, a screw that conveys and stirs the developer, a toner density sensor, and the like. The developing roller is composed of an outer rotatable sleeve and an inner magnet. In accordance with the output of the toner density sensor, toner is supplied from the toner supply device.

  The image forming apparatus of the present embodiment forms an electrostatic latent image corresponding to each color on the surface of the rotating photoreceptors 11Y, 11M, 11C, and 11K by the laser light L emitted from the optical writing unit 3, A toner image is formed by electrostatically adhering toner of each color supplied from the developing device to the latent image.

  On the other hand, the transfer paper 100 supplied from the paper feed cassettes 4a and 4b and the manual feed tray MF is transferred between the photoconductors 11Y, 11M, 11C, and 11K and the transfer rollers 67Y, 67M, 67C, and 67K by the transfer conveyance belt 60. It is conveyed and passes through transfer rolls 67Y, 67M, 67C, and 67K. At this time, the toner images of the respective colors held on the photoconductors 11Y, 11M, 11C, and 11K are transferred onto the transfer paper 100. The transfer paper 100 onto which the toner image has been transferred in this manner is heated and pressurized by the fixing unit to fix the toner image, and is conveyed and discharged in the direction of arrow B.

  The present embodiment is characterized by the arrangement of the lubricant application device. This point will be described with reference to FIG. 2 shows a photosensitive drum 11 on which an electrostatic latent image is formed, a charging device 14 for uniformly charging the surface of the photosensitive drum 11, a cleaning device 15, and first and second lubricant application devices 17. , 18 are diagrams showing a schematic configuration of the photoreceptor unit 2 which is a process cartridge integrally configured. The above-described photoreceptor unit 2 in the image forming apparatus of the present embodiment has the same configuration for 2Y, 2M, 2C, and 2K. Hereinafter, the configuration and the like are configured by the photoreceptor unit 2 shown in FIG. explain.

  The cleaning device 15 is driven by a cleaning blade 15a that scrapes off transfer residual toner remaining on the surface of the photoconductive drum 11 from the surface of the photoconductive drum 11 and a brush 15d planted on the rotary shaft 15c while being driven and rotated by a rotating means (not shown). A cleaning brush roller 15 b that captures the transfer residual toner held on the photosensitive drum 11 and cleans the photosensitive drum 11 is provided.

  A scraper 15e is provided in the vicinity of the cleaning brush roller 15b, and the scraper 15e is in contact with the brush 15d in order to scrape and remove the toner adhering to the brush fibers 15d of the cleaning brush roller 15b. The toner scraped off by the scraper 15e is moved to the toner transport auger 15f side, and the waste toner collected by rotating the toner transport auger 15f is transported to a waste toner storage unit (not shown).

  Next, the lubricant applying means in the present embodiment will be described. The lubricant applying means is a first lubricant applying device 17 arranged on the upstream side in the rotation direction X of the photosensitive member 1 of the cleaning blade 15a. And a second lubricant application device 18 disposed on the downstream side.

  The first lubricant application device 17 also serves as a cleaning brush roller 15 b that cleans the toner remaining after transfer from the photosensitive drum 11 as a means for applying the lubricant to the photosensitive drum 11. Further, the first lubricant application device 17 contacts the solid lubricant 17b, the cleaning brush roller 15b that contacts the solid lubricant 17b, scrapes the lubricant, and supplies it to the surface of the photosensitive drum 11, and the solid lubricant 17b. The pressure spring 17d presses the brush roller 15b against the brush roller 15b with a predetermined pressure, and the cleaning blade 15a also functions as an application blade for thinning the lubricant supplied onto the photosensitive drum 11. .

  Then, the first lubricant application device 17 applied the lubricant to the surface of the photosensitive drum 11 at the start of use to form a thin film of the lubricant, and occurred while the photosensitive drum 11 made a full circle. The transfer unit 6 and the developing device 10 also have a function of replenishing and repairing the abrasion of the lubricant layer due to the friction between the toner and the photosensitive member. In this case, the cleaning brush roller 15b and the cleaning blade 15a may be used exclusively as a cleaning member, and a brush roller and an application blade for applying a lubricant independent of the cleaning brush roller 15b and the cleaning blade 15a may be provided. .

  On the other hand, the second lubricant application device 18 described above includes a solid lubricant 18b, a brush roller 18a that contacts the solid lubricant 18b while rotating, scrapes the lubricant, and supplies the surface to the surface of the photosensitive drum 11. , And a coating blade 18c for thinning the supplied lubricant on the photosensitive drum 11. In this case, the coating blade 18c is not always necessary, but is preferably used because the supplied lubricant can be made thinner on the photosensitive drum 11.

  Further, the second lubricant application device 18 has a function of replenishing and repairing the abrasion of the lubricant layer due to the friction between the toner and the photosensitive member in the cleaning blade 15a. The amount of lubricant applied to the second lubricant application device 18 is adversely affected by the charging action on the charging device 14 if it is excessive, so it is preferable that the amount applied is smaller than that of the first lubricant application device 17.

  Therefore, in the present embodiment, the solid lubricant 18b is not pressed by the pressurizing means, and is brought into sliding contact with the brush-like roller 18a by the pressurization by its own weight. In this case, if necessary, as in the case of the first lubricant application device 17, a pressure spring may be used to pressurize the lubricant and press the brush roller 18a. Further, the lubricant used in the second lubricant application device 18 may be the same as the lubricant used in the first lubricant application device 17, but the first lubricant. A different lubricant such as a softer lubricant than the lubricant used in the coating device 17 can be used.

  The lubricant used in the present embodiment is a fatty acid metal salt, and the metal of the fatty acid metal salt is zinc, iron, calcium, aluminum, lithium, magnesium, strontium, barium, cerium, titanium, zirconium, lead. And at least one metal selected from manganese, wherein the fatty acid of the fatty acid metal salt is selected from lauric acid, stearic acid, palmitic acid, myristic acid, oleic acid A fatty acid metal salt is preferred.

  As this lubricant, a solid lubricant molded into a block shape or the like is preferable. Examples of the solid lubricants 17b and 18b include lead oleate, zinc oleate, copper oleate, zinc stearate, stearic acid. Fatty acid metal salts such as cobalt, iron stearate, copper stearate, zinc palmitate, copper palmitate, zinc linolenate, polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, polytrifluorochloroethylene, dichloro A resin obtained by molding and processing a fluororesin such as difluoroethylene, tetrafluoroethylene-ethylene copolymer, tetrafluoroethylene-oxafluoropropylene copolymer into a block shape is used. In particular, fatty acid metal salts are highly effective in reducing the friction of the photosensitive drum 11, and zinc stearate and calcium stearate using stearic acid as the fatty acid, zinc or calcium as the metal are more preferable.

  The cleaning brush roller 15b and the brush-like roller 18a are installed in parallel with the rotational axis of the photosensitive drum 11, and are in sliding contact with the photosensitive drum 11 over the entire width in the width direction (axial direction) of the photosensitive drum 11. Is applied.

  The pressure spring 17d is biased against the brush-like roller (cleaning brush roller) 15b so that almost all of the solid lubricant 17b is used up. Since the solid lubricant 17b is a consumable item, its thickness decreases with time, but since it is pressurized by the pressure spring 17d, the solid lubricant 17b is scraped off by always contacting the brush-like roller 17a. Then, it is supplied and applied to the surface of the photosensitive drum 11.

  Note that the first and second lubricant application devices 17 and 18 are not limited to the above-described configuration, and a configuration in which the solid lubricants 17b and 18b are applied in direct contact with the surface of the photosensitive drum 11 or powder. A configuration may be used in which a lubricant is supplied to the surface of the photosensitive drum 11. Thus, by providing the means for applying the lubricant to the surface of the photosensitive drum 11, the friction coefficient of the surface of the photosensitive drum 11 can be reduced, the adhesion between the surface of the photosensitive drum 11 and the toner is weakened, In addition to improving the transferability of the developed toner, it is possible to improve the cleaning performance of the toner remaining on the surface of the photosensitive drum 11 after the transfer by the cleaning blade 15a.

  In particular, this is an effective means in the case of using a toner having a reduced particle size and a spherical shape as shown below. By satisfactorily cleaning the toner remaining on the surface of the photosensitive drum 11, contamination on the surface of the charging roller 14a of the charging device 14 can be reduced. As a result, charging is performed so as to cleanly contact the charging roller 14a and clean the surface of the charging roller 14a. The life of the cleaning roller 14b can be extended. In this case, the charging roller 14a is preferably in a non-contact state with the photosensitive drum 11 and applied with a bias voltage in which direct current and alternating current are superimposed.

  Even if the lubricant applied to the surface of the photoconductive drum 11 and thinned is scraped off by the rubbing when the transfer residual toner is interposed between the cleaning blade and the photoconductor, the second lubricant is used. Even when the lubricant is supplemented by the coating device 18 and is partially scraped off at the development nip portion and the transfer nip portion, it is supplemented by the first lubricant coating device 17 so that it is constantly uniform in the width direction of the photosensitive drum 11. In addition, since the lubricant is thinned, transfer performance and cleaning performance can be improved.

  As the process cartridge in the present embodiment, the photosensitive drum 11, the cleaning device 15, the charging device 14, and the first and second lubricant application devices 17 and 18 are integrally configured. Not limited to the illustrated example, the charging device 14 may be a separate body, or conversely, a process cartridge in which the developing device 10 and the charge removal device are integrated into the above-described configuration may be used.

  In the image forming apparatus of this embodiment, the toner used in the developing device 10 has a volume average particle diameter 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 preferably a toner having a small particle size and a narrow particle size distribution in the range of 1.00 to 1.40. By using a toner having a small particle diameter, the toner can be densely attached to the latent image. Further, by narrowing the particle size distribution, the toner charge amount distribution becomes uniform, a high-quality image with little background fogging can be obtained, and the transfer rate can be increased. Further, since the amount of the reversely charged toner can be reduced, contamination on the surface of the charging roller 14a can be reduced, and the life of the charging cleaning roller 14b can be extended.

  The toner used in the developing device 10 is suitably particles having an average circularity in the range of 0.93 to 1.00, and can be defined by the values of the following shape factors SF-1 and SF-2. Spherical toner is preferred. FIG. 3 is a diagram schematically showing the shape of the toner for explaining the shape factor SF-1 and the shape factor SF-2. FIG. 3A shows the shape of the toner 5 in relation to the shape factor SF-1. (B) is a diagram showing the surface shape of the toner 5 in relation to the shape factor SF-2.

The shape factor SF-1 indicates the ratio of the roundness of the toner shape, and is expressed by the following formula (1). The square of the maximum length MXLNG of the shape formed by projecting the toner onto the two-dimensional plane is represented by the area AREA. Divided by 100π / 4.
SF-1 = {(MXLNG) ² / AREA} × (100π / 4) (1)
When the value of SF-1 is 100, the shape of the toner becomes a true sphere, and becomes larger as the value of SF-1 increases.

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 by the graphic area AREA and multiplying by 100π / 4.
SF-2 = {(PERI) ² / AREA} × (100π / 4) (2)
When the value of SF-2 is 100, there is no unevenness on the toner surface, and as the value of SF-2 increases, the unevenness of the toner surface becomes more prominent.

  Specifically, these shape factors are measured by taking a photograph of the toner with a scanning electron microscope (S-800: manufactured by Hitachi, Ltd.) and introducing it into an image analyzer (LUSEX 3: manufactured by Nireco). Analyzed and calculated.

  The toner in the present embodiment is a toner having SF-1 in the range of 100 to 180 and SF-2 in the range of 100 to 180. When the shape of the toner is close to a spherical shape, the contact between the toner and the toner or the toner and the photosensitive drum 11 is close to a point contact, so that the adsorbing force between the toners is weakened and the fluidity is increased. The adhesion force to the surface of the photosensitive drum 11 is also reduced, and the transfer rate is increased. On the other hand, since the spherical toner easily enters the gap between the cleaning blade 15a and the photosensitive drum 11, the toner shape factors SF-1 and SF-2 are preferably 100 or more. Further, when SF-1 and SF-2 are increased, toner is scattered on the image and the image quality is lowered. Therefore, it is preferable that the shape factors SF-1 and SF-2 of the toner do not exceed 180.

  The toner suitably used in the image forming apparatus of the present embodiment is, for example, a toner material in which at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent are dispersed in an organic solvent. It is a composition obtained by cross-linking and / or elongation reaction of a liquid in an aqueous solvent. Hereinafter, the constituent material and the manufacturing method of the toner will be described.

  The toner in this embodiment contains the modified polyester (1) as a binder resin. The modified polyester (1) 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 (1) 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 the like 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), and (DIO) or a mixture of (DIO) and a small amount of (TO) is 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 Lumpur acids (ethylene oxide, propylene oxide, butylene oxide, etc.) adducts.

  Among these, 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) and 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) , Naphthalenedicarboxylic acid, etc.). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. Examples of the trivalent or higher polyvalent carboxylic acid (TC) include aromatic polyvalent carboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). In addition, as polycarboxylic acid (PC), you may make it react with polyhydric alcohol (PO) using the acid anhydride or lower alkyl ester (methyl ester, ethyl ester, isopropyl ester, etc.) of the above-mentioned thing.

  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-diisocyanatomethyl caproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.) ); Aromatic diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanates; phenol derivatives, oximes, Those blocked with caprolactam and 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 B1 to B5 amino group blocked (B6) include ketimine compounds and oxazolidine compounds obtained from the amines of B1 to B5 and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Among these amines (B), preferred are B1 and a mixture of B1 and a small amount of B2.

  The ratio of amines (B) is equivalent to the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the polyester prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). Is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2. When [NCO] / [NHx] is more than 2 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 as well as a urea bond. The molar ratio of the urea bond content to the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance is deteriorated.

  The modified polyester (1) in the present embodiment is produced by a one-shot method or a prepolymer method. The weight average molecular weight of the modified polyester (1) is usually 10,000 or more, preferably 20,000 to 10,000,000, and more preferably 30,000 to 1,000,000. The peak molecular weight at this time is preferably 1,000 to 10,000. If it is less than 1,000, the elongation reaction hardly occurs and the elasticity of the toner decreases, and as a result, the hot offset resistance deteriorates. On the other hand, if it exceeds 10,000, the problem of production becomes high in the case where the fixing property is lowered and the particles are formed or crushed. The number average molecular weight of the modified polyester (1) is not particularly limited when the unmodified polyester (2) described later is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. (1) When used alone, the number average molecular weight is usually 20,000 or less, preferably 1,000 to 10,000, and more preferably 2,000 to 8,000. If it exceeds 20,000, 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) for obtaining the modified polyester (1), 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 the present embodiment, not only the modified polyester (1) is used alone, but also the unmodified polyester (2) can be contained as a binder resin component together with the (1). By using (2) in combination, the low-temperature fixability and the gloss when used in a full-color device are improved, which is preferable to single use. Examples of (2) include polycondensates of polyhydric alcohol (PO) and polyvalent carboxylic acid (PC) similar to the polyester component of (1) above, and preferred ones are also the same as (1). . Further, (2) is not limited to unmodified polyester, but may be modified with a chemical bond other than a urea bond, and may be modified with a urethane bond, for example. It is preferable that (1) and (2) are at least partially compatible with each other in terms of low-temperature fixability and hot offset resistance. Accordingly, the polyester component (1) and (2) preferably have similar compositions. In the case of containing (2), the weight ratio of (1) and (2) 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 (1) 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 (2) is usually 1,000 to 10,000, preferably 2,000 to 8,000, and more preferably 2,000 to 5,000. If it is less than 1,000, heat-resistant storage stability will deteriorate, and if it exceeds 10,000, low-temperature fixability will deteriorate. The hydroxyl value of (2) 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 (2), 1-5 are preferable, More preferably, it is 2-4. Since a high acid value wax is used for the wax, the binder is easily matched with the toner used for the two-component developer because the low acid value binder leads to charging and high volume resistance.

  The glass transition point (Tg) of the binder resin is usually 35 to 70 ° C, preferably 45 to 65 ° C. If the temperature is lower than 35 ° C., the heat-resistant storage stability of the toner is deteriorated. Since the urea-modified polyester is likely to be present on the surface of the obtained toner base particles, the toner in the present embodiment has good heat resistant storage stability even when the glass transition point is low, as compared with a known polyester-based toner. Show the trend. The outflow start temperature is preferably 90 ° C to 115 ° C.

(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 binder resin kneaded with the production of the masterbatch or the masterbatch, a polymer of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyltoluene and 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 used, 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- of a salicylic acid metal complex 84, E-89 of phenol-based condensate (above, manufactured by Orient Chemical Co., Ltd.), TP-302, TP-415 of quaternary ammonium salt molybdenum complex (made of 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 (above, manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (Nippon Carlit) ), Copper phthalocyanine, perylene, quinacridone, azo Pigment, 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. It is effective against high temperature offset 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 petrolatum. And petroleum wax. 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, 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%. The inorganic fine particles are preferably fine particles having a bulk density of 0.3 g / cm ³ or more. 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 both the fine particles have an average particle diameter of 5 × 10 ⁻² μm or less and are stirred and mixed, the electrostatic force and van der Waals force with the toner are remarkably improved. Even when stirring and mixing inside the developing device is performed to obtain a level, the fluidity imparting agent is not detached from the toner, a good image quality that does not cause firefly and the like can be obtained, and the transfer residual toner can be further reduced. Figured.

  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 liquid 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 or 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 with respect to 100 parts by weight of the toner material liquid is usually 50 to 2,000 parts by weight, preferably 100 to 1,000 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 20,000 parts by weight, it is not economical.

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

Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount. Examples of the anionic surfactant having a fluoroalkyl group that is preferably used include fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [ω-fluoroalkyl (C _6- C ₁₁ ) oxy] -1-alkyl (C ₃ -C ₄ ) sodium sulfonate, 3- [ω-fluoroalkanoyl (C ₆ -C ₈ ) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C ₁₁ ~C ₂₀₎ carboxylic acids and metal salts thereof, perfluoroalkyl carboxylic acids (C ₇ ~C ₁₃₎ and metal salts thereof, perfluoroalkyl (C ₄ ~C ₁₂₎ sulfonic acids and metal salts thereof, perfluorooctane Sulfonic acid diethanolamide, N-propyl-N- (2-hydroxyethyl) perfluoroo Tan sulfonamide, perfluoroalkyl (C ₆ ~C ₁₀₎ sulfonamide propyl trimethyl ammonium salts, perfluoroalkyl (C ₆ ~C ₁₀₎ -N- ethylsulfonyl glycine salts, monoperfluoroalkyl (C ₆ ~C ₁₆₎ Examples thereof include ethyl phosphate. Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101. DS-102 (manufactured by Daikin Industries, Ltd.), Megafac F-110, F-120, F-113, F-191, F-812, F-833 (manufactured by Dainippon Ink, Inc.), Xtop EF-102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fgentent F-100, F150 (manufactured by Neos).

In addition, examples of the cationic surfactant include aliphatic quaternary compounds such as aliphatic primary, secondary or secondary amine acids having a fluoroalkyl group, and perfluoroalkyl (C ₆ -C ₁₀ ) sulfonamidopropyltrimethylammonium salts. Ammonium salts, benzalkonium salts, benzethonium chloride, pyridinium salts, imidazolinium salts, and the like can be mentioned. DS-202 (manufactured by Daikin Industries Co., Ltd.), Mega-Fac F-150, F-824 (manufactured by Dainippon Ink, Inc.), Xtop EF-132 (manufactured by Tochem Products), and Footgent F-300 (manufactured by Neos) Etc.

  As the resin fine particles, any resin can be used as long as it can form an aqueous dispersion, and it may be a thermoplastic resin or a thermosetting resin. For example, vinyl resin, polyurethane resin, epoxy resin, polyester resin, polyamide resin, polyimide resin, silicon resin, phenol resin, melamine resin, urea resin, aniline resin, ionomer resin, polycarbonate resin and the like can be mentioned. As the resin, two or more of the above resins may be used in combination.

  Of these, vinyl resins, polyurethane resins, epoxy resins, polyester resins, and combinations thereof are preferred because an aqueous dispersion of fine spherical resin particles is easily obtained. For example, vinyl resins are polymers obtained by homopolymerization or copolymerization of vinyl monomers, such as styrene- (meth) acrylic acid ester copolymers, styrene-butadiene copolymers, (meth) acrylic acid-acrylic acid ester polymers. Examples thereof include resins such as a polymer, a styrene-acrylonitrile copolymer, a styrene-maleic anhydride copolymer, and a styrene- (meth) acrylic acid copolymer. The average particle size of the resin fine particles is 5 to 200 nm, preferably 20 to 300 nm.

  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 single monomers A mer 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- Hydroxypropyl, 3-chloro-2-hydroxypropyl acrylate, 3-chloro-2-hydroxypropyl methacrylate, 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, etc., or compounds containing vinyl alcohol and a carboxyl group Esters such as vinyl acetate, vinyl propionate, vinyl butyrate, etc., acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, vinyl pyridine, vinyl pyrrolidone, vinyl Homopolymers or copolymers such as nitrogen-containing compounds such as imidazole and ethyleneimine or those having a heterocyclic ring thereof, polyoxyethylene, polyoxypropylene , Polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxyethylene Polyoxyethylenes such as 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 type, a high-speed shear type, a friction type, a high-pressure jet type, 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 revolutions is not particularly limited, but is usually 1,000 to 30,000 rpm, preferably 5,000 to 20,000 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. Simultaneously with the preparation of the emulsion, the amines (B) are added to cause a reaction with the polyester prepolymer (A) having an isocyanate group. This reaction involves molecular chain crosslinking and / or elongation. The reaction time is selected depending on the reactivity of the isocyanate group structure of the polyester prepolymer (A) with the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 24 hours. The reaction temperature is generally 0 to 150 ° C, preferably 40 to 98 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.

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

  5. The toner base particles obtained above are charged with a charge control agent as required, 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 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.

  Further, the shape of the toner in the present embodiment is a substantially spherical shape, and can be represented by the following shape rule. FIG. 4 is a diagram schematically illustrating the shape of the toner in the present embodiment. FIG. 4A is a schematic diagram illustrating the toner particles 5 in a three-dimensional XYZ axis, and FIG. FIG. 4C is a schematic diagram of the toner particle 5 represented by the XY axis, and FIG. 5C is a schematic diagram of the toner particle 5 represented by the YZ axis. In FIG. 4, 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 in the present embodiment has a major axis and a minor axis. The ratio (r2 / r1) to the axis (see FIG. 4B) is 0.5 to 1.0, and the ratio (r3 / r2) between the thickness and the minor axis (see FIG. 4C) is 0. It is preferable that it exists in the range of 7-1.0. When the ratio of the major axis to the minor axis (r2 / r1) is less than 0.5, the dot reproducibility and transfer efficiency are inferior because of being away from the true spherical shape, and high-quality image quality cannot be obtained. On the other hand, if the ratio of thickness to minor axis (r3 / r2) is less than 0.7, the shape is close to a flat shape, and a high transfer rate like a spherical toner cannot be obtained. In particular, when the ratio of the thickness to the minor axis (r3 / r2) is 1.0, the rotating body has a major axis as a rotation axis, and the fluidity of the toner can be improved. Note that r1, r2, and r3 were measured with a scanning electron microscope (SEM) while changing the angle of field of view and taking pictures.

  The toner produced as described above can also be used as a one-component magnetic toner that does not use a magnetic carrier or a non-magnetic toner. Further, when used in a two-component developer, it may be used by mixing with a magnetic carrier, and the magnetic carrier is a ferrite containing a divalent metal such as iron, magnetite, Mn, Zn, Cu, A volume average particle size of 20 to 100 μm is preferred. If the average particle size is less than 20 μm, carrier adhesion is likely to occur on the photoreceptor 1 during development. Cheap.

  Further, Cu ferrite containing Zn is preferable because of high saturation magnetization, but can be appropriately selected according to the process of the image forming apparatus 100. Although it does not specifically limit as resin which coat | covers a magnetic carrier, For example, there exist a silicone resin, a styrene-acryl resin, a fluorine-containing resin, an olefin resin etc. In the manufacturing method, the coating resin may be dissolved in a solvent, sprayed into a fluidized bed and coated on the core, or the resin particles are electrostatically attached to the core particles and then thermally melted for coating. It may be a thing. The resin to be coated has a thickness of 0.05 to 10 μm, preferably 0.3 to 4 μm.

  The above-described embodiment is a preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiment alone, and various modifications are made without departing from the gist of the present invention. Implementation is possible.

1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a cross-sectional view illustrating a schematic configuration of a photoreceptor unit according to an embodiment of the present invention. 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 a toner shape according to an exemplary embodiment of the present invention.

Explanation of symbols

1Y, 1M, 1C, 1K Image forming unit 2, 2Y, 2M, 2C, 2K Photosensitive unit 5 Toner particles 10Y, 10M, 10C, 10K Developing device 11, 11Y, 11M, 11C, 11K Photosensitive drum 14 Charging device 15 Cleaning device 15a Cleaning blade 15b Cleaning brush roller 15c Rotating shaft 15d Brush 15e Scraper 15f Toner transport auger 17 First lubricant application device 17b, 18b Solid lubricant 17d Pressure spring 18 Second lubricant application device 18a Brush roller 18c Coating blade 60 Transfer conveyor belt 67Y, 67M, 67C, 67K Transfer roller 100 Transfer paper

Claims (18)

A photosensitive member that forms a latent image; a charging device that uniformly charges the surface of the photosensitive member; an exposure device that exposes the charged surface of the photosensitive member based on image data and writes a latent image; and the surface of the photosensitive member An image forming apparatus comprising: a developing device that supplies toner to a latent image formed on the surface to visualize the latent image; and a cleaning device that cleans the surface of the photoreceptor.
An image forming apparatus comprising: a lubricant application device for applying a lubricant to the surface of the photoconductor at a plurality of locations on the outer periphery of the photoconductor.   The cleaning device includes a cleaning blade that removes transfer residual toner remaining on the surface of the photoconductor, and the lubricant application device disposed at the plurality of locations includes a first lubrication disposed upstream of the cleaning blade. 2. The image forming apparatus according to claim 1, further comprising an agent coating device and a second lubricant coating device disposed downstream of the cleaning blade.   3. The image forming apparatus according to claim 1, wherein the plurality of lubricant application devices vary the amount of lubricant applied to the surface of the photosensitive member. 4.   4. The image forming apparatus according to claim 1, wherein the plurality of lubricant application devices vary the material of the lubricant applied to the surface of the photoreceptor. 5.   The plurality of lubricant application devices include a lubricant supply roller having a brush for supplying a lubricant to the surface of the photoconductor, and applies the lubricant supplied by the lubricant supply roller on the photoconductor. The image forming apparatus according to claim 1, further comprising a blade.   The lubricant is a fatty acid metal salt, and the metal of the fatty acid metal salt is selected from zinc, iron, calcium, aluminum, lithium, magnesium, strontium, barium, cerium, titanium, zirconium, lead, and manganese. Wherein the fatty acid metal salt is at least one fatty acid selected from lauric acid, stearic acid, palmitic acid, myristic acid, and oleic acid. The image forming apparatus according to claim 1.   7. The charging device according to claim 1, wherein the charging device includes a charging member that is not in contact with the photosensitive member, and a bias voltage in which direct current and alternating current are superimposed is applied to the charging member. The image forming apparatus described.   The toner has a weight average particle diameter of 3 to 8 μm and a ratio (Dv / Dn) of the weight average particle diameter (Dv) to the number average particle diameter (Dn) is in the range of 1.00 to 1.40. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.   9. The image forming apparatus according to claim 1, wherein the toner particles have an average circularity in a range of 0.93 to 1.00. 10. The toner particle according to claim 1, wherein the toner 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. 11. Image forming apparatus. (However, the shape factors SF-1 and SF-2 are the maximum shape length (MXLNG), figure area (AREA), figure circumference (PERI) formed by projecting toner particles on a two-dimensional plane, (It has the relationship of following Formula (1) and (2).)
SF-1 = {(MXLNG) ² / AREA} × (100π / 4) (1)
SF-2 = {(PERI) ² / AREA} × (100π / 4) (2) The image according to any one of claims 1 to 10, wherein the toner contains fine particles having an average primary particle diameter of 50 to 500 nm and a bulk density of 0.3 g / cm ³ or more. Forming equipment.   12. The image forming apparatus according to claim 1, wherein the toner contains a binder resin having a glass transition temperature of 35 to 70 ° C. and an outflow start temperature of 90 to 115 ° C. 12. .   In the toner, 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 is crosslinked and / or extended in an aqueous medium. 13. The image forming apparatus according to claim 1, wherein the image forming apparatus is a composition obtained by causing the composition to form. In a process cartridge in which a photosensitive member carrying a latent image and a cleaning device for cleaning residual toner on the photosensitive member are at least integrally configured and detachably attached to an image forming apparatus main body,
A process cartridge characterized in that a lubricant application device for applying a lubricant to the surface of the photoconductor is provided integrally with the photoconductor and a cleaning device at a plurality of locations on the outer periphery of the photoconductor.   The cleaning device includes a cleaning blade that removes transfer residual toner remaining on the surface of the photoreceptor, and a lubricant application device disposed at the plurality of locations is a first disposed at an upstream side of the cleaning blade. The process cartridge according to claim 14, further comprising a lubricant applying device and a second lubricant applying device disposed on the downstream side of the cleaning blade.   The process cartridge according to claim 14, wherein the plurality of lubricant application devices vary the amount of lubricant applied to the surface of the photoreceptor.   The process cartridge according to any one of claims 14 to 16, wherein the plurality of lubricant application devices vary the material of the lubricant applied to the surface of the photoreceptor.   The plurality of lubricant application devices include a lubricant supply roller having a brush for supplying a lubricant to the surface of the photoconductor, and an application blade for leveling the lubricant supplied by the supply roller on the photoconductor The process cartridge according to claim 14, further comprising a process cartridge.

Images