JP2010169884A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a charging device achieving high durability by relatively simple control operation, a process cartridge having the charging device, and an image forming apparatus. <P>SOLUTION: In the image forming apparatus 1, a lubricant application blade 34 is an elastic body formed in a sheet shape; an edge part of the blade 34 is pressed in a counter position; a cleaning device 20 has a cleaning blade 21 which comes in contact with a photoreceptor 3 to clean it; the cleaning blade 21 can perform operation of contact with and separation from the photoreceptor 3; and the operation of contact with and separation from the photoreceptor 3 by the cleaning blade 21 is controlled according to information held by the image forming apparatus 1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, and a fax machine, and more particularly to an image forming apparatus using an intermediate transfer member.

2. Description of the Related Art Conventionally, in an electrophotographic image forming apparatus, there is known a cleaning device that cleans unnecessary transfer residual toner or paper dust attached to the surface of an image bearing member or an intermediate transfer member with a cleaning member.
However, in recent years, an image formed by the image forming apparatus is required to be a highly accurate image. In order to cope with this highly accurate image, a toner having a small average particle diameter is often used. However, if the average particle size of the toner is small, there is a problem that it is difficult to clean the blade system.
For this reason, in order to improve the cleaning property of the toner, a lubricant is applied on the photoreceptor. For example, in Patent Document 1, a cleaning is provided in which a lubricant leveling blade is provided to abut the image carrier downstream of the cleaning member in the moving direction of the image carrier and level the lubricant applied to the image carrier. An apparatus is described.

  However, in the case where the blade member is provided downstream of the cleaning member in the moving direction of the image carrier as in the cleaning device described in Patent Document 1, depending on the image to be formed, the edge portion of the blade member is missing. As a result, the toner slipped from the lubricant and the cleaning member from the chipped portion may be streaked, and the charging member in contact with or close to the image carrier may be soiled, resulting in poor charging.

On the other hand, by inputting particles such as toner and lubricant between the blade member and the image carrier that is the object to be coated, chipping of the edge portion of the blade member can be suppressed, and for a long time. It has been found that charging failure can be prevented.
Therefore, the present invention has been made in view of the above problems, and the problem is that a charging device that can achieve high durability by a relatively simple control operation, a process cartridge having the charging device, and an image forming apparatus. 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 according to the present invention has a roller-shaped charging member disposed in contact with or close to the image carrier to charge the image carrier, and a downstream of a cleaning device that cleans deposits on the image carrier. On the side, a lubricant application device provided with a lubricant, an application roller for applying the lubricant to the image carrier, and a leveling member that extends the lubricant applied on the image carrier to form a thin layer The leveling member is an elastic body formed in a sheet shape, and the edge portion is pressed in a counter posture, and the cleaning device abuts against the image carrier to perform cleaning. The cleaning member is capable of moving to and away from the image carrier, and the cleaning member can be brought into contact with and separated from the image carrier in accordance with information held by the image forming apparatus. Image forming apparatus characterized by work is controlled.
The image forming apparatus of the present invention further includes a counting unit that counts the area of the image to be formed, and the information held by the image forming apparatus is information by the counting unit. .
The image forming apparatus of the present invention is further characterized in that the cleaning member is separated when the count value by the counting means is not more than a predetermined value.
Further, in the image forming apparatus of the present invention, the information held by the image forming apparatus is information obtained by counting the number of print pixels that are pixels to which toner is to be attached based on image data of the image forming apparatus. It is characterized by being.
The image forming apparatus according to the present invention further includes a process in which at least one of a charging device, a developing device, a cleaning device, and a lubricant applying device and an image carrier are integrally configured to be detachable from the main body of the image forming device. It is a cartridge form.
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.

The present invention, which is a means for solving the above problems, has the following specific effects.
In the image forming apparatus of the present invention, the lubricant is extended to form a thin layer by controlling the contact and separation of the member to be cleaned with respect to the image carrier in accordance with the information held by the image forming apparatus. The toner is input to the leveling member and the lubricant is extended to suppress chipping of the edge portion of the blade, which is a leveling member that forms a thin layer.

1 is a diagram illustrating a schematic configuration of an image forming apparatus according to the present invention. It is a figure which expands and shows one of four image formation units. It is a graph which shows the relationship between an image area ratio (%) and the frequency | count of occurrence of an edge defect. FIG. 6 is a diagram schematically illustrating the shape of a toner in order to explain the shape factor SF-1 and the shape factor SF-2. FIG. 3 is a diagram schematically illustrating the shape of toner used by the image forming apparatus of the present invention.

  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.

Embodiments of the present invention will be specifically described below with reference to the drawings.
FIG. 1 is a diagram showing a schematic configuration of an image forming apparatus according to the present invention.
The image forming apparatus includes an intermediate transfer belt 51 in the approximate center of the inside thereof. The intermediate transfer belt 51 is an endless belt made of a heat-resistant material such as polyimide or polyamide and having a base adjusted to a medium resistance. The intermediate transfer belt 51 is supported by being wound around four rollers 531, 532, 533, and 534. It is rotationally driven in the direction of arrow A. Below the intermediate transfer belt 51, four image forming units corresponding to yellow (Y), magenta (M), cyan (C), and black (K) toners are arranged along the belt surface of the intermediate transfer belt 51. It is out.

FIG. 2 is an enlarged view showing one of the four image forming units. Since any image forming unit has the same configuration, Y, M, C, and K indicating color distinction are omitted in this figure. Each image forming unit includes photoreceptors 3Y, 3M, 3C, and 3K. Around each photoreceptor 3, a charging roller 11 that applies charges to the surface of the photoreceptor 3 and a latent image formed on the surface of the photoreceptor 3 are displayed. Lubricant coating including a developing device 40 that develops toner with each color toner to form a toner image, a brush roller 31 that applies a lubricant 32 to the surface of the photoreceptor 3, and a lubricant application blade 34 that equalizes the lubricant applied by the brush roller. A device 30 and a cleaning device 20 including a cleaning blade 21 for cleaning the surface of the photosensitive member 3 after the toner image transfer are disposed. Thus, in FIG. 2, one process cartridge 2 is formed. The process cartridge 2 integrally supports at least one of the photosensitive member 3 and the charging device 10, the developing device 40, the cleaning device 20, and the lubricant application device, and is detachable from the image forming apparatus 1. It has become.
Further, referring to FIG. 1, below the four image forming units, there are provided exposure devices 9 for exposing the surface of each charged photoreceptor 3 based on the image data of each color and forming a latent image. Yes.
A primary transfer roller 52 that primarily transfers a toner image formed on the photoconductor 3 onto the intermediate transfer belt 51 is disposed at a position facing each photoconductor 3 with the intermediate transfer belt 51 interposed therebetween. The primary transfer roller 52 is connected to a power source (not shown) and is applied with a predetermined voltage.

A secondary transfer roller 54 is pressed against the outside of the portion of the intermediate transfer belt 51 supported by the support roller 532. The secondary transfer roller 54 is connected to a power source (not shown) and is applied with a predetermined voltage. A contact portion between the secondary transfer roller 54 and the intermediate transfer belt 51 is a secondary transfer portion, and the toner image on the intermediate transfer belt 51 is transferred onto a recording sheet.
An intermediate transfer belt cleaning device 55 for cleaning the surface of the intermediate transfer belt 51 after the secondary transfer is provided outside the portion of the intermediate transfer belt 51 supported by the support roller 531.
A fixing device 70 is provided above the secondary transfer unit to fix the toner image on the recording paper semi-permanently on the recording paper. The fixing device 70 includes a fixing roller 71 and a pressure roller 72 that is disposed opposite to and in pressure contact with a halogen heater therein. In addition, although not shown, instead of the fixing roller 71, a heating roller having a halogen heater inside and an endless fixing belt wound around the fixing roller may be used.
Below the image forming apparatus, there is provided a paper feeding device 60 for placing the recording paper and feeding the recording paper toward the secondary transfer unit.

Next, referring to FIG. 2, the configuration around the photoconductor of the image forming apparatus will be described in detail.
Each element shown in FIG. 2 may be separately assembled in the image forming apparatus main body, but in the illustrated example, a charging device including a charging roller 11, a charging roller pressing spring 12, and a charging cleaner roller 13, A lubricant application device 30, a developing device 40, a cleaning blade 21, and a waste unit including a lubricant 32, a lubricant pressure spring 33, a brush roller 31 for applying the lubricant, and a lubricant application blade 34 for leveling the lubricant. A process in which at least one cleaning device including the toner collecting coil 22 and a member to be charged made of the photosensitive member 3 are integrally assembled to form a photosensitive member unit, and the unit can be attached to and detached from the image forming apparatus main body. Mounted as a cartridge 2.

The photoconductor 3 is an organic photoconductor, and a surface protective layer is formed of a polycarbonate resin.
The charging device 10 includes a charging roller 11 configured by covering a conductive cored bar with a medium-resistance elastic layer as a charging member. The charging roller 11 is connected to a power source (not shown) and is applied with a predetermined voltage. The charging roller 11 is disposed with a small gap with respect to the photoreceptor 3. The minute gap is set by, for example, winding a spacer member having a certain thickness around the non-image forming regions at both ends of the charging roller 11 to bring the surface of the spacer member into contact with the surface of the photosensitive member 3. can do. Further, the charging roller 11 may be brought close to the photosensitive member without contacting the photosensitive member. The photosensitive member 3 can be charged by discharging at a portion that is in a roller shape and is close to the photosensitive member 3. Further, the non-contact can suppress the occurrence of contamination due to the transfer residual toner of the charging roller 11.
Further, the charging roller 11 is provided with a charging cleaner roller 13 for cleaning the surface of the charging roller 11 in contact with the charging roller 11.
In the developing device 40, a developing sleeve (not shown) provided with a magnetic field generating means is disposed at a position facing the photoconductor 3. Below the developing sleeve, there are provided two screws (not shown) for mixing toner introduced from a toner bottle (not shown) with the developer and pumping it up to the developing sleeve while stirring. The developer composed of toner and magnetic carrier pumped up by the developing sleeve is regulated to a predetermined developer layer thickness by a doctor blade (not shown) and is carried on the developing sleeve. The developing sleeve carries and conveys the developer while moving in the same direction at a position facing the photoreceptor 3 and supplies toner to the latent image surface of the photoreceptor 3.

The cleaning device 20 includes a mechanism in which the cleaning blade 21 serving as a cleaning member abuts and separates from the photosensitive member 3 (not shown), and can be arbitrarily abutted and separated by the control unit of the image forming apparatus main body.
The lubricant application device 30 is applied by a solid lubricant 32 housed in a fixed case, a brush roller 31 that contacts the solid lubricant 32 and scrapes the lubricant, and is applied to the photoreceptor 3 and the brush roller 31. A lubricant application blade 34 for leveling the lubricant is provided. The solid lubricant 32 is formed in a rectangular parallelepiped shape and is urged toward the brush roller 31 by a pressure spring 33. The solid lubricant 32 is scraped off and consumed by the brush roller 31, and its thickness decreases with time. However, since the solid lubricant 32 is pressurized by the pressure spring 33, the solid lubricant 32 is always in contact with the brush roller 31. The brush roller 31 applies the lubricant scraped off while rotating to the surface of the photoreceptor 3.
The thickness of the brush fiber of the brush roller 31 is preferably 3 to 8 denier, and the density of the brush fiber is preferably 20,000 to 100,000 pieces / inch2. If the thickness of the brush fiber is too thin, the brush roller 31 is liable to fall when the brush roller 31 comes into contact with the surface of the photoconductor 3, and conversely, if the brush fiber is too thick, the density of the fiber cannot be increased. In addition, if the density of the brush fibers is low, the number of brush fibers in contact with the surface of the photoconductor 3 is small, so that the lubricant cannot be applied uniformly. Conversely, if the density of the brush fibers is too high, The gap becomes small, and the amount of the lubricant powder that has been scraped off decreases, resulting in an insufficient amount of coating.
Therefore, the brush roller 31 having the above-mentioned setting range having the thickness of the brush fiber for preventing the hair from collapsing and the density of the brush fiber capable of efficiently applying the lubricant uniformly.

  As the solid lubricant 32, a dry solid hydrophobic lubricant can be used. In addition to zinc stearate, barium stearate, lead stearate, iron stearate, nickel stearate, cobalt stearate Those having a stearic acid group such as copper stearate, 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. Further, waxes such as candelilla wax, carnauba wax, rice wax, wax, ooba oil, beeswax, and lanolin can be used.

In this embodiment, a lubricant application blade 34 as a lubricant leveling means is brought into contact with the surface of the photoreceptor on the downstream side in the moving direction with respect to the lubricant application position by the brush roller 31. The lubricant application blade 34 is made of rubber which is an elastic body, has a function as a cleaning means, and is in contact with the moving direction of the photosensitive member 3 in the counter direction. However, when the lubricant application blade 34 is contacted in the counter direction, chipping occurs at the edge portion of the contacted blade, the charging roller 11 is soiled, and vertical streak-like charging failure may occur at an early stage. . In addition, when the lubricant application blade 34 is installed in the trailing direction, there is a problem in that the ability to clean the transfer residual toner that has passed through cannot be sufficiently ensured, resulting in poor cleaning.
Therefore, the present inventor inputs the toner to the lubricant applying blade 34 arranged in a counter manner downstream of the cleaning blade 21 in the moving direction of the photosensitive member by the investigation as shown in FIG. It has been found that edge chipping of the blade 34 can be suppressed.
FIG. 3 is a graph showing the relationship between the image area ratio (%) and the number of occurrences of edge defects.
The graph shown in FIG. 3 shows that a new process cartridge is set in the image forming apparatus, A4 landscape paper (A4 size 210 mm x 297 mm, meaning that the paper transport direction is 210 mm), five continuous 500 sheets, a total of 2500 sheets. It is the graph which investigated the number of edge missing generation | occurrence | production of the lubricant application | coating blade 34 in each image area when running 5 times. The image area ratio (%) is A4 size 100%.

As shown in the figure, for the case where no toner (= transfer residual toner) is input to the lubricant application blade 34, the number of edge defects increases as the image area decreases, whereas the cleaning blade 21 increases. When the transfer residual toner was directly input to the lubricant application blade 34 with the toner being separated from the photosensitive member 3, no edge chipping occurred even once. Thus, it can be seen that by supplying toner to the lubricant application blade 34, it is possible to prevent the lubricant application blade 34 that is disposed downstream of the cleaning blade 21 in the moving direction of the photosensitive member. As a result, the lubricant 32 due to the amount of residual toner is extended by controlling the contact and separation of the cleaning blade 21 with respect to the photoreceptor 3 in accordance with the information of the counting means. The toner input to the lubricant coating blade 34 forming the thin layer is made uniform, and the lubricant 32 is extended to suppress the chipping of the edge portion of the blade that is the lubricant coating blade 34 forming the thin layer. Charge failure can be prevented.
In the present embodiment, a counting unit that counts the image area formed on the main body of the image forming apparatus 1 is mounted, and the cumulative image forming area for every 100 sheets is counted.
The color image information read by a scanner (not shown) is temporarily stored in the image memory unit via the main control unit, and then color-separated for each color, and the writing control circuit of the exposure apparatus 4 as color-separated image data. Sent to. The writing control circuit drives the semiconductor laser while driving the polygon motor based on the transmitted color separation image data to rotate the polygon mirror. The laser beam LD emitted from the semiconductor laser by this driving is reflected by a regular hexahedral polygon mirror and changed in the main scanning direction, and optically scans the photoreceptor 3 of the photoreceptor unit via a reflection mirror (not shown). To do. At this time, the write control circuit calculates the number of write pixels based on the color separation image data of each color, and calculates the area of the image formed by the toner, the ratio of the white background portion and the image portion of the toner, etc. can do. This result is transmitted to the main control unit. The main control unit performs predetermined control on each color developing device based on the calculated value of the number of write pixels sent from the write control circuit.
When the accumulated image area is equal to or less than a predetermined value (for example, an accumulated image area value where the image area per sheet is 2% or less), a flag for executing the separation operation of the cleaning blade 21 is set, and the image operation currently being executed After completion, the cleaning blade 21 is separated from the photoreceptor 3. As a result, at the time of the next image formation, the cleaning blade 21 inputs the transfer residual toner blocked at the previous image formation and the transfer residual toner at the time of the currently executed image formation to the lubricant application blade 34. . As a result, it is considered that blade edge chipping of the lubricant application blade 34 can be suppressed. In addition, the cleaning blade 21 is brought into contact again because the accumulated image area after the separation is greater than or equal to a predetermined value (for example, the accumulated value of the image area is equivalent to an A4 size of 400% or more = equivalent to 80 sheets or more if the image is 5%). At this time, it is considered that the cleaning performance of the original two blades can be ensured by setting a flag for executing the contact operation of the cleaning blade 21 and bringing the cleaning blade 21 into contact after the currently executed image forming operation. . Thus, the lubricant 32 due to the amount of residual toner is extended by controlling the contact and separation operation of the cleaning blade 21 with respect to the photoreceptor 3 in accordance with the information of the counting means. The toner input to the lubricant coating blade 34 forming the thin layer is made uniform, and the lubricant 32 is extended to suppress chipping of the edge portion of the blade that is the lubricant coating blade 34 forming the thin layer. Charge failure can be prevented.
Note that the timing at which the cleaning blade 21 is separated and brought into contact may affect the torque fluctuation of the photosensitive member 3 during the separation or contact in the middle of the image forming operation, or an image in which vibration occurs. Thus, it is preferable that the image forming apparatus 1 is stopped, for example, after the image forming operation is completed.

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

The toner shape factor SF-1 is preferably in the range of 100 to 180, and the shape factor SF-2 is preferably in the range of 100 to 180. FIG. 4 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. The shape factor SF-1 indicates the ratio of the roundness of the toner shape and is represented by the following formula (1). This is a value obtained by dividing the square of the maximum length MXLNG of the shape formed by projecting toner on a two-dimensional plane by the figure area AREA and multiplying by 100π / 4.
SF-1 = {(MXLNG) 2 / AREA} × (100π / 4) Formula (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 represented by the following formula (2). A value obtained by dividing the square of the perimeter PERI of the figure formed by projecting the toner on the two-dimensional plane by the figure area AREA and multiplying by 100π / 4.
SF-2 = {(PERI) 2 / AREA} × (100π / 4) (2)
When the value of SF-2 is 100, 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.
Specifically, the shape factor is measured by taking a photograph of the toner with a scanning electron microscope (S-800: manufactured by Hitachi, Ltd.), introducing it into an image analyzer (LUSEX 3: manufactured by Nireco) and analyzing it. Calculated.
When the shape of the toner is close to a spherical shape, the contact state between the toner and the toner or the toner and the photoconductor becomes a point contact, so that the adsorbing force between the toners becomes weak and the fluidity increases, and the toner and the photoconductor The attraction force becomes weaker and the transfer rate becomes higher. If any of the shape factors SF-1 and SF-2 exceeds 180, the transfer rate is lowered, which is not preferable.

The toner suitably used in the image forming apparatus of the present invention includes a toner material liquid 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. A toner obtained by crosslinking and / or elongation reaction in an aqueous solvent. Hereinafter, the constituent material and the manufacturing method of the toner will be described.
(polyester)
The polyester is obtained by a polycondensation reaction between a polyhydric alcohol compound and a polycarboxylic acid compound.
Examples of the polyhydric alcohol compound (PO) include dihydric alcohol (DIO) and trihydric or higher polyhydric alcohol (TO). (DIO) alone or a mixture of (DIO) and a small amount of (TO) preferable. Examples of the dihydric alcohol (DIO) include alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (diethylene glycol) , Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol) F, bisphenol S, etc.); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol; Alkylene oxide bisphenol (ethylene oxide, propylene oxide, butylene oxide, etc.), etc. adducts. Among them, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use. As trihydric or higher polyhydric alcohol (TO), 3 to 8 or higher polyhydric aliphatic alcohol (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (Trisphenol PA, phenol novolak, cresol novolak, etc.); and alkylene oxide adducts of the above trivalent or higher polyphenols.

  Examples of the polyvalent carboxylic acid (PC) include divalent carboxylic acid (DIC) and trivalent or higher polyvalent carboxylic acid (TC). (DIC) alone and (DIC) with a small amount of (TC) Mixtures are preferred. Divalent carboxylic acids (DIC) include alkylene dicarboxylic acids (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acids (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid) And naphthalenedicarboxylic acid). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. Examples of the trivalent or higher polyvalent carboxylic acid (TC) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). In addition, as polyhydric carboxylic acid (PC), you may make it react with polyhydric alcohol (PO) using the above-mentioned acid anhydride or lower alkyl ester (Methyl ester, ethyl ester, isopropyl ester, etc.).

The ratio of the polyhydric alcohol (PO) to the polycarboxylic acid (PC) is usually 2/1 to 1/1, preferably as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. Is 1.5 / 1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.
The polycondensation reaction between a polyhydric alcohol (PO) and a polycarboxylic acid (PC) is carried out in the presence of a known esterification catalyst such as tetrabutoxytitanate or dibutyltin oxide, and heated to 150 to 280 ° C. while reducing the pressure as necessary. The produced water is distilled off to obtain a polyester having a hydroxyl group. The hydroxyl value of the polyester is preferably 5 or more, and the acid value of the polyester is usually 1 to 30, preferably 5 to 20. By giving an acid value, it tends to be negatively charged, and furthermore, when fixing to a recording paper, the affinity between the recording paper and the toner is good and the low-temperature fixability is improved. However, when the acid value exceeds 30, there is a tendency to deteriorate with respect to the stability of charging, particularly environmental fluctuation.
The weight average molecular weight is 10,000 to 400,000, preferably 20,000 to 200,000. A weight average molecular weight of less than 10,000 is not preferable because offset resistance deteriorates. On the other hand, if it exceeds 400,000, the low-temperature fixability is deteriorated.

In addition to the unmodified polyester obtained by the above polycondensation reaction, the polyester preferably contains a urea-modified polyester. The urea-modified polyester is obtained by reacting a terminal carboxyl group or hydroxyl group of the polyester obtained by the above polycondensation reaction with a polyvalent isocyanate compound (PIC) to obtain a polyester prepolymer (A) having an isocyanate group. It is obtained by cross-linking and / or extending the molecular chain by the reaction of the amine with amines.
Examples of the polyvalent isocyanate compound (PIC) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.) Aromatic diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanates; Those blocked with caprolactam or the like; and combinations of two or more of these.
The ratio of the polyvalent isocyanate compound (PIC) is usually 5/1 to 1/1, preferably as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. 4/1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. When the molar ratio of [NCO] is less than 1, when a urea-modified polyester is used, the urea content in the ester is lowered and hot offset resistance is deteriorated.
The content of the polyvalent isocyanate compound (PIC) component in the polyester prepolymer (A) having an isocyanate group is usually 0.5 to 40 wt%, preferably 1 to 30 wt%, more preferably 2 to 20 wt%. . If it is less than 0.5 wt%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40 wt%, the low-temperature fixability deteriorates.
The number of isocyanate groups contained per molecule in the polyester prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2 on average. Five. If it is less than 1 per molecule, the molecular weight of the urea-modified polyester will be low, and the hot offset resistance will deteriorate.

Next, as amines (B) to be reacted with the polyester prepolymer (A), a divalent amine compound (B1), a trivalent or higher polyvalent amine compound (B2), an amino alcohol (B3), an amino mercaptan (B4) ), Amino acid (B5), and amino acid block of B1 to B5 (B6).
Examples of the divalent amine compound (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′-dimethyldicyclohexyl). Methane, diamine cyclohexane, isophorone diamine, etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.) and the like. Examples of the trivalent or higher polyvalent amine compound (B2) include diethylenetriamine and triethylenetetramine. Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid. Examples of the compound (B6) obtained by blocking the amino group of B1 to B5 include ketimine compounds and oxazolidine compounds obtained from the amines of B1 to B5 and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Among these amines (B), preferred are B1 and a mixture of B1 and a small amount of B2.

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

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

When reacting (PIC) and when reacting (A) and (B), a solvent may be used if necessary. Usable solvents include aromatic solvents (toluene, xylene, etc.); ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.); esters (ethyl acetate, etc.); amides (dimethylformamide, dimethylacetamide, etc.) and ethers And those inert to isocyanates (PIC), such as tetrahydrofuran (such as tetrahydrofuran).
In addition, in the crosslinking and / or extension reaction between the polyester prepolymer (A) and the amines (B), a reaction terminator may be used as necessary to adjust the molecular weight of the resulting urea-modified polyester. Examples of the reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).
The weight average molecular weight of the urea-modified polyester is usually 10,000 or more, preferably 20,000 to 10,000,000, and more preferably 30,000 to 1,000,000. If it is less than 10,000, the hot offset resistance deteriorates. The number average molecular weight of the urea-modified polyester or the like is not particularly limited when the above-mentioned unmodified polyester is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. When the urea-modified polyester is used alone, its number average molecular weight is usually 2000-15000, preferably 2000-10000, more preferably 2000-8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color apparatus are deteriorated.

By using the unmodified polyester and the urea-modified polyester in combination, the low-temperature fixability and the gloss when used in the full-color image forming apparatus 100 are improved. Therefore, it is preferable to use the urea-modified polyester alone. The unmodified polyester may include a polyester modified with a chemical bond other than a urea bond.
The unmodified polyester and the urea-modified polyester are preferably at least partially compatible with each other in terms of low-temperature fixability and hot offset resistance. Therefore, it is preferable that the unmodified polyester and the urea-modified polyester have a similar composition.
The weight ratio of unmodified polyester to urea-modified polyester is usually 20/80 to 95/5, preferably 70/30 to 95/5, more preferably 75/25 to 95/5, and particularly preferably 80 /. 20-93 / 7. When the weight ratio of the urea-modified polyester is less than 5%, the hot offset resistance is deteriorated, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

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

(Coloring agent)
As the colorant, all known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher , Yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Vulcan fast yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Phi Sayred, Parachlor Ortonito Aniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine B, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R , Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Tolujing Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thio Indigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red Polyazo Red, Chrome Vermillion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), indigo, ultramarine blue, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Lid Russian nin green, anthraquinone green, titanium oxide, zinc white, litbon and mixtures thereof can be used. The content of the colorant is usually 1 to 15% by weight, preferably 3 to 10% by weight, based on the toner.

  The colorant can also be used as a master batch combined with a resin. As a binder resin to be kneaded together with the production of a master batch or a master batch, a polymer of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyl toluene, or a substituted product thereof, or a copolymer of these and a vinyl compound, Polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, fat Aromatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, paraffin waxes and the like can be mentioned, and these can be used alone or in combination.

(Charge control agent)
Known charge control agents can be used, such as nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified 4 Secondary ammonium salts or compounds, tungsten simple substances or compounds, fluorine activators, salicylic acid metal salts, and metal salts of salicylic acid derivatives. Specifically, Bontron 03 of a nigrosine dye, Bontron P-51 of a quaternary ammonium salt, Bontron S-34 of a metal-containing azo dye, E-82 of an oxynaphthoic acid metal complex, E-84 of a salicylic acid metal complex , Phenolic condensate E-89 (above, Orient Chemical Industries, Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, Hodogaya Chemical Co., Ltd.), quaternary ammonium salt copy Charge PSY VP2038, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (Nippon Carlit) Manufactured), copper phthalocyanine, perylene, quinacridone, azo series Fee, a sulfonic acid group, a carboxyl group, and polymer compounds having a functional group such as quaternary ammonium salts. Of these, substances that control the negative polarity of the toner are particularly preferably used.
The amount of charge control agent used is determined by the type of binder resin, the presence or absence of additives used as necessary, and the toner production method including the dispersion method, and is not uniquely limited. Preferably, it is used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the charge control agent is reduced, the electrostatic attraction with the developing roller is increased, the developer fluidity is lowered, and the image density is lowered. Invite.

(Release agent)
As a release agent, a low melting point wax having a melting point of 50 to 120 ° C. works more effectively as a release agent in the dispersion with the binder resin between the fixing roller and the toner interface. The effect on high temperature offset is exhibited without applying a release agent such as oil. Examples of such a wax component include the following. Examples of waxes and waxes include plant waxes such as carnauba wax, cotton wax, wood wax, rice wax, animal waxes such as beeswax and lanolin, mineral waxes such as ozokerite and cercin, and paraffin, microcrystalline, And petroleum waxes such as petrolatum. In addition to these natural waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax and polyethylene wax, and synthetic waxes such as esters, ketones, and ethers can be used. Furthermore, fatty acid amides such as 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide, chlorinated hydrocarbon, and low molecular weight crystalline polymer resin, poly-n-stearyl methacrylate, poly-n- A crystalline polymer having a long alkyl group in the side chain such as a homopolymer or copolymer of polyacrylate such as lauryl methacrylate (for example, a copolymer of n-stearyl acrylate-ethyl methacrylate, etc.) can also be used. .
The charge control agent and the release agent can be melt-kneaded together with the masterbatch and the binder resin, or may be added when dissolved and dispersed in an organic solvent.

(External additive)
Inorganic fine particles are preferably used as an external additive for assisting the fluidity, developability and chargeability of the toner particles. The primary particle diameter of the inorganic fine particles is preferably 5 × ¹⁰ -3 ~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 2000 parts by weight, it is not economical.

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

Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount. Preferred anionic surfactants having a fluoroalkyl group include fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [ω-fluoroalkyl (C6-C11 ) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [ω-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carvone Acids and metal salts, perfluoroalkylcarboxylic acids (C7 to C13) and metal salts thereof, perfluoroalkyl (C4 to C12) sulfonic acids and metal salts thereof, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- ( 2-Hydroxyethyl) Perful Olooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. Can be mentioned.
Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101. DS-102 (manufactured by Daikin Industries, Ltd.), Megafac F-110, F-120, F-113, F-191, F-812, F-833 (manufactured by Dainippon Ink, Inc.), Xtop EF-102, 103, 104, 105, 112, 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. Salts, benzalkonium salts, benzethonium chloride, pyridinium salts, imidazolinium salts, trade names include Surflon S-121 (Asahi Glass Co., Ltd.), Florard FC-135 (Sumitomo 3M Co., Ltd.), Unidyne DS-202 (Daikin Industries) Smoke), Megafac F-150, F-824 (Dainippon Ink Co., Ltd.), Xtop EF-132 (Tochem Products), Footage F-300 (Neos), and the like.

The resin fine particles are added to stabilize the toner base particles formed in the aqueous medium. For this reason, it is preferable to add so that the coverage existing on the surface of the toner base particles is in the range of 10 to 90%. For example, polymethyl methacrylate fine particles 1 μm and 3 μm, polystyrene fine particles 0.5 μm and 2 μm, poly (styrene-acrylonitrile) fine particles 1 μm, trade names are PB-200H (manufactured by Kao), SGP (manufactured by Soken), Techno Examples include polymer SB (manufactured by Sekisui Chemical Co., Ltd.), SGP-3G (manufactured by Sokensha), and micropearl (manufactured by Sekisui Fine Chemical Co., Ltd.).
In addition, inorganic compound dispersants such as tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, and hydroxyapatite can also be used.

  As a dispersant that can be used in combination with the above resin fine particles and inorganic compound dispersant, the dispersed droplets may be stabilized by a polymer protective colloid. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride and other (meth) acrylic monomers containing hydroxyl groups Bodies such as acrylic acid-β-hydroxyethyl, methacrylic acid-β-hydroxyethyl, acrylic acid-β-hydroxypropyl, methacrylic acid-β-hydroxypropyl, acrylic acid-γ-hydroxypropyl, methacrylic acid-γ-hydroxy Propyl, acrylic acid-3-chloro-2-hydroxypropyl, methacrylic acid-3-chloro-2-hydroxypropyl, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate Luric acid esters, N-methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, or compounds containing vinyl alcohol and a carboxyl group Esters such as vinyl acetate, vinyl propionate, vinyl butyrate, acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, vinyl pyridine, vinyl pyrrolidone, vinyl Nitrogen compounds such as imidazole and ethyleneimine, or homopolymers or copolymers such as those having a heterocyclic ring thereof, polyoxyethylene, poly Xoxypropylene, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxy Polyoxyethylenes such as ethylene nonylphenyl ester, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.

  The dispersion method is not particularly limited, and known equipment such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, and an ultrasonic wave can be applied. Among these, the high-speed shearing method is preferable in order to make the particle size of the dispersion 2 to 20 μm. When a high-speed shearing disperser is used, the 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 according to the present invention has a substantially spherical shape and can be represented by the following shape rule.
FIG. 5 is a diagram schematically showing the shape of the toner used by the image forming apparatus of the present invention. In FIG. 5, 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 (b)) is 0.5 to 1.0, and ratio of thickness to minor axis (r3 / r2) (see (c)) is 0.7 to 1.0. It is preferable to be in the range. 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.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Process cartridge 3 Photoconductor 4 Exposure apparatus 10 Charging apparatus 11 Charging roller 12 Charging roller pressurizing spring 13 Charging cleaner roller 14 Charging cleaner roller pressurizing spring 20 Cleaning device 21 Cleaning blade 22 Waste toner collection coil 30 Lubricant Coating device 31 Brush roller 32 Lubricant 33 Pressure spring 34 Lubricant coating blade 40 Developing device 50 Transfer device 51 Intermediate transfer belt 52 Primary transfer roller 531, 532, 533, 534 Support roller 54 Secondary transfer roller 55 Intermediate transfer belt cleaning Device 60 Paper feed device 61 Paper feed unit 62 Paper feed roller 63 Registration roller 64 Paper discharge roller 65 Paper discharge stock unit 70 Fixing device

JP 2001-305907 A

Claims (9)

A charging device for charging the image carrier by placing a roller-shaped charging member in contact with or in proximity to the image carrier;
On the downstream side of the cleaning device that cleans deposits on the image carrier,
A lubricant,
An application roller for applying a lubricant to the image carrier;
In an image forming apparatus equipped with a lubricant application device provided with a leveling member that extends a lubricant applied on an image carrier to form a thin layer,
The leveling member is an elastic body formed in a sheet shape, and the edge portion is pressed in a counter posture,
The cleaning device includes a cleaning member that contacts and cleans the image carrier, and the cleaning member can move away from and contact the image carrier, depending on information held by the image forming apparatus. An image forming apparatus, wherein the operation of contacting and separating the cleaning member with respect to the image carrier is controlled. The image forming apparatus according to claim 1,
The image forming apparatus includes a counting unit that counts an area of an image to be formed.
The information held by the image forming apparatus is information by the counting unit. The image forming apparatus according to claim 2.
The image forming apparatus is characterized in that the cleaning member is separated when the count value by the counting means is not more than a predetermined value. The image forming apparatus according to any one of claims 1 to 3,
The information held by the image forming apparatus is information obtained by counting the number of print pixels, which are pixels to which toner is attached, based on image data of the image forming apparatus. The image forming apparatus according to claim 1,
An image forming apparatus comprising a process cartridge in which at least one of a charging device, a developing device, a cleaning device, and a lubricant coating device and an image carrier are integrally formed and detachable from a main body of the image forming device. . 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.

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