JP2005249917A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a process cartridge and an image forming apparatus in which the frictional coefficient on a photoreceptor can be decreased by a simple structure to increase cleaning property and an image of high quality can be printed even when a toner having high circularity is used. <P>SOLUTION: In the image forming apparatus employing a blade cleaning system and using a toner having high circularity, the revolution or the revolting time of a brush roller 62 in a cleaning device is controlled according to the image area rate on the surface of a photoreceptor 1 so as to control the supply amount of a lubricant 64 to the photoreceptor 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus of a blade cleaning type using an electrophotographic process such as a copying machine, a printer, and a facsimile.

Currently, in order to improve the image quality, the toner is reduced in particle size and increased in circularity. Since toners manufactured by the pulverization method have limitations in these characteristics, polymerized toners manufactured by a suspension polymerization method, an emulsion polymerization method, a dispersion polymerization method, etc. capable of reducing the particle size and increasing the circularity are available. It is being adopted.
In general, it is known that toner having a high degree of circularity has poor cleaning properties. This is due to the fact that in a conventional rubber blade that has been used as a cleaning means when pulverized toner is used, the toner rolls without being caught by the blade edge, and thus the blade is easy to slip through. In particular, some toners produced by the polymerization method are close to true spheres (average circularity of 0.98 or more), and are difficult to clean by the above blade cleaning method.

As a cleaning method in the case of using toner having a high degree of circularity, the following proposal has been made in the blade cleaning method. In Patent Document 1, a lubricant is mixed with a developer, and the slippage is prevented by applying the developer to the photoconductor and reducing the friction coefficient during non-printing according to the image area ratio on the photoconductor. The cleaning property is improved.
In Patent Document 2, a flicker roller is arranged between the lubricant and the application roller, the toner density on the photoconductor is detected based on the image area ratio on the photoconductor, and the lubricant is pressed against the flicker roller. By adjusting the amount to be applied and reducing the coefficient of friction of the photoconductor, slipping is prevented and cleaning performance is improved.
Both Patent Documents 1 and 2 have a common difference in reducing the coefficient of friction in accordance with the image area ratio on the photoconductor, but the method is different. Patent Document 1 describes that the lubricant is uniformly applied to the developer. However, Patent Document 2 has a problem that an adjustment mechanism for pressing the lubricant against the flicker roller is required.

JP 2003-241570 A JP-A-8-234642

  In view of the above problems, the present invention provides a process cartridge capable of printing a high-quality image by reducing the friction coefficient on the photosensitive member and improving the cleaning property with a simple configuration even when toner having high circularity is used. An image forming apparatus is provided.

In order to solve the above problems, the present invention described in claim 1 includes an image carrier that carries a latent image, a charging unit that uniformly charges the surface of the image carrier, and a surface of the charged image carrier. An exposure unit that performs exposure based on image data and writes a latent image, a developing unit that supplies toner to the latent image formed on the surface of the image carrier and visualizes the image, and calculates an image area of the visible image An image area calculating means, an image area ratio calculating means for the traveling area of the image carrier of the image area, a transfer means for transferring a visible image on the surface of the image carrier to a transfer medium, and a surface of the image carrier after the transfer In an image forming apparatus comprising a cleaning means for cleaning and applying a lubricant to the surface of the image carrier through a fur brush, the surface of the image carrier is changed according to the image area ratio of the visible image on the surface of the image carrier. Adjusting means to adjust the amount of lubricant to be applied An image forming apparatus.
According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the adjusting means adjusts the amount of the lubricant by adjusting the number of rotations of the rotatable brush roller. An image forming apparatus.
According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the adjusting unit adjusts the amount of lubricant by adjusting a rotation time of a rotatable brush roller. An image forming apparatus characterized by the above.

According to a fourth aspect of the present invention, in the image forming apparatus according to the first or second aspect of the present invention, the supply of the lubricant is completed and the developing operation for the latent image corresponding to the previous transfer paper is completed in one print job. After that, before starting the developing operation corresponding to the next transfer paper, the image forming apparatus is characterized in that the lubricant is supplied to the image carrier.
According to a fifth aspect of the present invention, in the image forming apparatus according to the first or third aspect, the lubricant is supplied to the image carrier between the print job and the print job. The image forming apparatus is characterized.
According to a sixth aspect of the present invention, in the image forming apparatus according to any one of the first to fifth aspects, the cleaning unit moves in a rotational direction of the image carrier from a contact position between the image carrier and the brush roller. It is a cleaning blade located downstream and in contact with the image carrier.
A seventh aspect of the present invention is the image forming apparatus according to the sixth aspect, wherein the cleaning blade has a bending stiffness of 300 mN (measurement conditions 5 mm, 5 °) or more. is there.
The invention according to claim 8 is the image forming apparatus according to claim 6 or 7, wherein the cleaning blade has a JIS-A hardness of 60 or more.

According to a ninth aspect of the present invention, there is provided the image forming apparatus according to any one of the first to eighth aspects, wherein the image bearing member and the cleaning unit are at least integrally supported and are supported by the main body of the image forming apparatus. An image forming apparatus using a process cartridge formed to be detachable.
According to a tenth aspect of the present invention, in the image forming apparatus according to any one of the first to ninth aspects, the toner has a weight average particle diameter of 10 μm or less, and has a weight average particle diameter and a number average particle diameter. The image forming apparatus is characterized in that the ratio (dispersion degree) is in the range of 1.00 to 1.40.
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 circularity in a range of 0.95 to 1.00. An image forming apparatus.
According to a twelfth aspect of the present invention, in the image forming apparatus according to any one of the first to eleventh aspects, the toner has a substantially spherical appearance, and a ratio of a major axis to a minor axis (r2). / R1) is in the range of 0.5 to 1.0, and the ratio of thickness to minor axis (r3 / r2) is in the range of 0.7 to 1.0, where the major axis r1 ≧ minor axis r2 ≧ thickness. The image forming apparatus satisfies the relationship r3.
According to a thirteenth aspect of the present invention, in the image forming apparatus according to any one of the first to twelfth aspects, the toner is a polyester prepolymer having at least a functional group containing a nitrogen atom, a polyester, a colorant, a release agent. An image forming apparatus characterized in that a toner material solution in which a mold is dissolved or dispersed in an organic solvent is crosslinked and / or extended in an aqueous medium.
A fourteenth aspect of the present invention is a toner used in the image forming apparatus according to any one of the first to ninth aspects, wherein the weight average particle diameter is 10 μm or less, and the weight average particle diameter and the number average particle diameter. The image forming apparatus is characterized in that the ratio (dispersion degree) to the range is 1.00 to 1.40.

According to a fifteenth aspect of the present invention, in the toner according to the fourteenth aspect, the toner has an average circularity in the range of 0.95 to 1.00.
According to a sixteenth aspect of the present invention, in the toner according to the fourteenth or fifteenth aspect, the appearance of the toner is substantially spherical, and the ratio of the major axis to the minor axis (r2 / r1) is 0. In the range of 5 to 1.0, the ratio of thickness to minor axis (r3 / r2) is in the range of 0.7 to 1.0, and the relationship of major axis r1 ≧ minor axis r2 ≧ thickness r3 is satisfied. The toner is characterized by that.
According to a seventeenth aspect of the present invention, in the toner according to any one of the fourteenth to sixteenth aspects, the toner includes at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent. A toner material solution obtained by dissolving or dispersing each in a solvent is crosslinked and / or elongated in an aqueous medium.

  The present invention provides a process cartridge and an image forming apparatus capable of printing a high-quality image by reducing the friction coefficient on the photosensitive member with a simple configuration and improving the cleaning performance even when toner having high circularity is used. can do.

  The best mode for carrying out the present invention will be described below with reference to the drawings. The following description is an example of the best mode of the present invention, and it is easy for those skilled in the art to make other embodiments within the scope of the claims by making changes and modifications within the scope of the claims. However, this does not limit the scope of the claims.

FIG. 1 is a schematic configuration diagram of an image forming apparatus according to the present invention. The main part of the image forming apparatus includes a photosensitive member 1 as a latent image carrier, a charging device 2, a developing device 4, a transfer device 5, a cleaning device 6, a latent image forming device and a fixing device (not shown).
An original image is exposed on the photosensitive member 1 uniformly charged by the charging device 2 to form a latent image, and then a toner is attached to the latent image by the developing device 4 to visualize the toner image. . This toner image is transferred to transfer paper or an intermediate transfer medium by the transfer device 5. The toner remaining on the photoconductor 1 after the transfer is removed from the photoconductor by the cleaning device 6, and the photoconductor is continuously used repeatedly.

The photoconductor 1 can be made of amorphous metal having photoconductivity, amorphous metal such as amorphous selenium, or organic compound such as bisazo pigment or phthalocyanine pigment. In consideration of environmental problems and post-treatment after use, an OPC photoreceptor using an organic compound is preferable.
The charging device 2 may be any one of a corona method, a roller method, a brush method, and a blade method. Here, the charging device 2 of a roller method is shown. The charging device 2 includes a charging roller 2a, a charging roller cleaning member 2b that is in contact with the charging roller 2a for cleaning, and a power source (not shown) connected to the charging roller 2a. A high voltage is applied to the charging roller 2a to generate corona discharge with the photosensitive member 1 to uniformly charge the surface of the photosensitive member 1.
The developing device 4 includes a developer carrier 4a that carries the developer and supplies it to the photosensitive member 1, a toner supply chamber (not shown), and the like. The developer carrier 4a includes a hollow cylindrical developer carrier 4a that is rotatably supported, and a magnet roll fixed coaxially with the developer carrier 4a. The developer is magnetically attracted to the outer peripheral surface of the carrier 4a and conveyed. The developer carrier 4a is electrically conductive and is made of a nonmagnetic member, and is connected to a power source (not shown) for applying a developing bias. A voltage is applied from the power source between the developer carrying member 4a and the photoreceptor 1, and an electric field is formed in the developing region.

  One embodiment of the cleaning device 6 according to the present invention will be described with reference to FIG. The cleaning device 6 includes a cleaning blade 61 in contact with the photoreceptor 1, and a lubricant application unit 62 that scrapes off the solid lubricant 64 and supplies the solid lubricant 64 onto the photoreceptor 1 upstream of the cleaning blade 61 in the rotational direction of the photoreceptor 1. Is provided. The lubricant applying unit 62 also has a function as a toner removing unit. The toner remaining on the photoconductor 1 after the primary transfer is first collected from the photoconductor 1 by the toner removing means 62. Subsequently, the fine particles of the solid lubricant 64 are supplied onto the photoreceptor 1 by the lubricant application means 62, and the toner, filming, etc. remaining on the photoreceptor 1 are finally scraped off by the cleaning blade 61. In FIG. 1, the lubricant application unit also has a toner removal unit.

Next, a brush roller 62 is used as the lubricant applying means 62 that also serves as a toner removing means, as shown in FIG. The fur brush of the brush roller 62 is formed using a material adjusted to a volume resistivity of 1 × 10 ³ to 1 × 10 ⁸ Ω · cm by adding a resistance control material such as carbon black to a resin such as nylon or acrylic. ing. The brush roller 62 is provided with a solid lubricant 64 in contact with its own weight. Examples of the solid lubricant 64 include fatty acid metals such as lead oleate, zinc oleate, copper oleate, zinc stearate, cobalt stearate, iron stearate, copper stearate, zinc palmitate, copper palmitate and zinc linoleate. Although salts can be used, among these, zinc stearate is used in this example.
The brush roller 62 is driven to rotate to scrape the solid lubricant 64 and supply the finely divided lubricant to the surface of the photoreceptor 1. Thereafter, due to the contact between the surface of the photoreceptor 1 and the cleaning blade 61, the lubricant is stretched to become a thin film, and the friction coefficient of the surface of the photoreceptor 1 is reduced. The rotation direction of the brush roller 62 is rotating in the same direction at the joint position with the photosensitive member. The amount of biting of the brush into the photoreceptor is 1.0 mm.

The brush roller 62 scrapes off the solid lubricant 64 and supplies it to the photoreceptor 1, while collecting the toner remaining on the photoreceptor 1. Particularly after using a toner having a reduced particle size and a spherical shape and forming an image with a high image area ratio, reducing the toner input to the cleaning blade 61 as much as possible is effective for good cleaning. Is.
If the impact resilience at 10 ° C. to 40 ° C. is 40% or less, the cleaning blade 61 that scrapes off the toner adhering to the photosensitive member is less likely to cause the blade and chatter. Further, the wear of the photoreceptor is reduced. Since the rebound resilience is small, so-called stick-slip at the contact portion of the photoreceptor is reduced, and wear is considered to be reduced. Further, the cleaning property is improved when the bending stiffness at a distance of 5 mm from the fulcrum when the cleaning blade is bent 5 degrees is 300 mN or more. When the bending stiffness is low, when the contact is made under the same condition, the linear pressure at the portion where the blade comes into contact with the photosensitive member is lowered, and the force for preventing the toner from slipping is reduced.
When the JIS-A hardness of the cleaning blade is 60 or more, the cleaning property is more stable. When the hardness is low, the blade in contact with the photosensitive member is easily deformed, and the contact pressure of the blade is reduced by increasing the contact area of the blade, and the force for preventing the toner from slipping through is reduced. Further, since the force to push back when the toner is pushed into the blade edge is weakened, the toner is easy to slip through.
As described above, in order to improve the cleaning property of the photosensitive member by blade cleaning, it is necessary to reduce the friction coefficient of the surface of the photosensitive member 1.

In the embodiment according to the present invention, the amount of the lubricant 64 applied to the photoconductor 1 is optimized by controlling the number of rotations of the brush roller 62 in order to reduce the friction coefficient of the surface of the photoconductor 1.
FIG. 2 is a flowchart showing an example of lubricant application control. That is, when the printing operation is started, the original image is exposed to form a latent image on the photoconductor, and then toner is attached to the latent image by the developing device 4 to be visualized as a toner image. Is transferred to transfer paper or an intermediate transfer medium by the transfer device 4. After the transfer, a control CPU (not shown) reads the calculated image area ratio, and changes the number of rotations of the brush roller according to the read image area ratio. In the present embodiment, the number of rotations is changed in three stages of an image area ratio of less than 25%, 25 or more, less than 50, and 50% or more, but is not limited to three stages. If it is 50% or more, it is possible to control at an arbitrary rotation speed or rotation time. When the brush roller 62 is controlled by the rotation time, a lubricant is applied at the end of the print job, that is, between the print job.

The image area ratio is calculated by the following procedure. The image area ratio is
[Image area ratio] = [Image area] / [Running area]
The image area is an image area of an image that is developed by the developing device and formed on the photoreceptor, and can be calculated from the following equation.
[Image area] = [Count pixel count] x [Area of one pixel]
The number of pixels to be written is counted to calculate the number of pixels to be counted. Here, since the area of one pixel is determined in advance, the image area can be known.
The travel area is calculated from the travel distance of the photoconductor based on the image developed by the developing device and formed on the photoconductor, and the width of the photoconductor that can be imaged.
[Traveling area] = [traveling distance] x [imaging width]
Here, since the image forming width is determined in advance, the traveling area can be known by obtaining the traveling distance.
The travel distance can be calculated from the following equation.
[Travel distance] = [photoreceptor count rotation speed] × [photoreceptor circumference] or [travel distance] = [photoreceptor count rotation time] × [photoreceptor linear speed]
Here, since the circumferential length and linear velocity of the photosensitive member 1 are determined in advance, the traveling distance can be known by counting the number of rotations or the rotation time of the photosensitive member 1.
As described above, the image area ratio that is the ratio of the image area to the traveling area of the photosensitive member 1 is calculated. Then, the lubricant is supplied to the photosensitive member based on the calculated image area ratio.

The reason why the supply of the lubricant 64 can be controlled by the rotation speed of the brush roller 62 is that the rotation speed or rotation time of the brush roller 62 is substantially proportional to the supply of the lubricant 64.
FIG. 3 is a diagram showing the relationship between the rotation time of the brush roller 62 and the consumption amount of the lubricant 64. In order to clarify the influence of the lubricant 64 deposited on the photosensitive member 1 on the consumption amount of the lubricant, the photosensitive member 1 is replaced every hour, or the photosensitive member 1 is replaced every two hours. The consumption amount of the lubricant 64 was examined in three ways when the oil was not replaced. As shown in FIG. 3, it can be seen that the lubricant 64 is consumed in proportion to the rotation time in all three ways.
As described in this embodiment, the lubricant 64 is supplied to the photoconductor 1 with a simple configuration by controlling the rotation speed or the rotation time of the brush roller 62 according to the image area ratio. It becomes possible to maintain the friction coefficient of the surface at 0.25 or less, and it becomes possible to improve the cleaning property with certainty.

The photosensitive member 1 and the cleaning device 6 of the present invention described above can be integrally supported and a process cartridge can be formed detachably on the image forming apparatus main body. In addition to this, the process cartridge may include a charging device 2 and / or a developing device 4. This process cartridge can improve the cleaning on the photoconductor 1 and cause deterioration in image quality even in an image forming process in which development using a toner having a high circularity and a small particle diameter is performed. There can be no process cartridge.
In addition, the process cartridge is advantageous in terms of maintenance, and if a failure occurs due to the photosensitive member, the cleaning device, the charging device 2 and / or the developing device 4, etc., it is only necessary to replace the cartridge. Since the original state can be restored at an early stage, the service time can be shortened. Further, by making the electrophotographic photosensitive member easy to clean, it greatly contributes to extending the life of the process cartridge.

The image forming apparatus that can obtain the effect of mounting the cleaning device 6 of the present invention is a case where the toner used in the developing means 4 is a toner having a high degree of circularity with an average circularity of 0.95 or more.
Therefore, even when the toner having a high average circularity as described above is used, the surface of the photoreceptor 1 can be efficiently cleaned as follows by the cleaning device 6 of the present invention. That is, the residual toner on the photosensitive member 1 is first collected by the brush roller 62 that also serves as a toner removing unit, and then the solid lubricant 64 is applied to the surface of the photosensitive member 1 by the brush roller 62, and the friction coefficient of the photosensitive member 1 surface is determined. The remaining toner is scraped off and finally removed by the cleaning blade 61. Cleaning can be performed efficiently without damaging the surface of the photoreceptor 1.

The toner is also suitable for cleaning toner having a nearly spherical shape. The spherical toner can be defined by the values of the following shape factors SF-1 and SF-2. The toner used in the image forming apparatus is a toner having a shape factor SF-1 of 100 to 180 and a shape factor SF-2 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 the toner on a two-dimensional plane by the figure area AREA and multiplying by 100π / 4.
SF-1 = {(MXLNG) ² / AREA} × (100π / 4) (1)
When the value of SF-1 is 100, the shape of the toner 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) Expression (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, the shape factor is measured by taking a photograph of the toner with a scanning electron microscope (S-800: manufactured by Hitachi, Ltd.), introducing it into an image analyzer (LUSEX 3: manufactured by Nireco) and analyzing it. Calculated.
When the shape of the toner is close to a sphere, the contact point between the toner and the toner or the toner and the photoconductor 1 is brought into contact, so that the adsorbing force between the toners becomes weak and the fluidity becomes high. The attraction force becomes weaker and the transfer rate becomes higher. On the other hand, as described above, the spherical toner is liable to cause a cleaning failure in the blade-type cleaning, but can be satisfactorily cleaned by the cleaning device 6 of the present invention. If SF-1 and SF-2 are increased, toner is scattered on the image and the image quality is lowered. Therefore, it is preferable that SF-1 and SF-2 do not exceed 180.

  The volume average particle diameter of the toner is 3 to 8 μm, and the ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) is in the range of 1.00 to 1.40. Even when a toner having a small particle size and a narrow particle size distribution is used, good cleaning properties can be obtained. By narrowing the particle size distribution of the toner, the charge amount distribution becomes uniform, a high-quality image with little background fogging can be obtained, and the transfer rate can be increased. It is difficult to clean such a small particle size toner by overcoming the adhesion force with the photoreceptor 1 by the conventional blade type cleaning. Further, when the particle size is small, the content of the external additive fine particles and the like of the toner tends to be relatively high, so that they are detached from the toner and filming is likely to occur on the photoreceptor 1. However, with the cleaning device 6 of the present invention, the brush roller 62 applies the lubricant to the surface of the photoconductor 1 well, thereby reducing the coefficient of friction on the surface of the photoconductor 1 and improving the cleaning performance of the cleaning blade 61. Can do.

  The toner suitably used in the image forming apparatus of the present invention is a toner material in which at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent are dissolved or dispersed in an organic solvent. It is a toner obtained by crosslinking and / or extending the liquid in an aqueous solvent. Hereinafter, the constituent material and the manufacturing method of the toner will be described.

(Modified polyester)
The toner of the present invention contains a modified polyester (i) as a binder resin. The modified polyester (i) refers to a state in which a bonding group other than an ester bond is present in the polyester resin, or resin components having different configurations are bonded to the polyester resin by a covalent bond, an ionic bond, or the like. Specifically, the polyester terminal is modified by introducing a functional group such as a carboxylic acid group or an isocyanate group that reacts with a hydroxyl group into the polyester terminal and further reacting with an active hydrogen-containing compound.

  Examples of the modified polyester (i) include urea-modified polyester obtained by a reaction between a polyester prepolymer (A) having an isocyanate group and amines (B). As the polyester prepolymer (A) having an isocyanate group, a polyester having a polycondensate of a polyhydric alcohol (PO) and a polyvalent carboxylic acid (PC) and having an active hydrogen group is further added to a polyvalent isocyanate compound (PIC). And those reacted with. Examples of the active hydrogen group possessed by the polyester include a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group, and the like. Among these, an alcoholic hydroxyl group is preferable.

The urea-modified polyester is produced as follows.
Examples of the polyhydric alcohol compound (PO) include dihydric alcohol (DIO) and trihydric or higher polyhydric alcohol (TO). (DIO) alone or a mixture of (DIO) and a small amount of (TO) preferable. Examples of the dihydric alcohol (DIO) include alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (diethylene glycol) , Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol) F, bisphenol S, etc.); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol; Alkylene oxide bisphenol (ethylene oxide, propylene oxide, butylene oxide, etc.), etc. adducts. Among them, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use. The trihydric or higher polyhydric alcohol (TO) includes 3 to 8 or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (Trisphenol PA, phenol novolak, cresol novolak, etc.); and alkylene oxide adducts of the above trivalent or higher polyphenols.

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

  The ratio of the polyhydric alcohol (PO) to the polycarboxylic acid (PC) is usually 2/1 to 1/1, preferably as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. Is 1.5 / 1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.

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

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

The content of the polyvalent isocyanate compound (PIC) component in the polyester prepolymer (A) having an isocyanate group is usually 0.5 to 40 wt%, preferably 1 to 30 wt%, more preferably 2 to 20 wt%. . If it is less than 0.5 wt%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40 wt%, the low-temperature fixability deteriorates.
The number of isocyanate groups contained per molecule in the polyester prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2 on average. Five. If it is less than 1 per molecule, the molecular weight of the urea-modified polyester will be low, and the hot offset resistance will deteriorate.

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

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

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

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

  The peak molecular weight of (ii) is 1000-10000 normally, Preferably it is 2000-8000, More preferably, it is 2000-5000. If it is less than 1000, heat-resistant storage stability will deteriorate, and if it exceeds 10,000, low-temperature fixability will deteriorate. The hydroxyl value of (ii) is preferably 5 or more, more preferably 10 to 120, and particularly preferably 20 to 80. If it is less than 5, it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. As for the acid value of (ii), 1-5 are preferable, More preferably, it is 2-4. Since a high acid value wax is used as the wax, the low acid value binder leads to electrification and high volume resistance, so that it is easy to match the toner used for the two-component developer.

  The glass transition point (Tg) of the binder resin is usually 35 to 70 ° C, preferably 55 to 65 ° C. If the temperature is lower than 35 ° C., the heat-resistant storage stability of the toner deteriorates, and if it exceeds 70 ° C., the low-temperature fixability becomes insufficient. Since the urea-modified polyester is likely to be present on the surface of the obtained toner base particles, the toner of the present invention tends to have good heat storage stability even when the glass transition point is low, as compared with known polyester-based toners. Show.

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

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

(Charge control agent)
Known charge control agents can be used, such as nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified 4 Secondary ammonium 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 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. 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 flowability of the developer is lowered, and the image density is lowered. Invite.

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

(External additive)
Inorganic fine particles are preferably used as an external additive for assisting the fluidity, developability and chargeability of the toner particles. The primary particle diameter of the inorganic fine particles is preferably 5 × ¹⁰ -3 ~2μm, it is particularly preferably 5 × ¹⁰ -3 ~0.5μm. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g. The use ratio of the inorganic fine particles is preferably 0.01 to 5 wt% of the toner, and particularly preferably 0.01 to 2.0 wt%.
Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, quartz sand, clay, mica, wollastonite, diatomaceous earth. Examples include soil, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. Among these, as the fluidity imparting agent, it is preferable to use hydrophobic silica fine particles and hydrophobic titanium oxide fine particles in combination. In particular, when stirring and mixing are performed using particles having an average particle diameter of 5 × 10 ⁻² μm or less, the electrostatic force and van der Waals force with the toner are remarkably improved. Even when stirring and mixing inside the developing device is performed to obtain a good image quality that does not cause the release of the fluidity imparting agent from the toner and does not generate firefly, etc., and further reduces the residual toner. It is done.
Titanium oxide fine particles are excellent in environmental stability and image density stability, but have a tendency to deteriorate the charge rise characteristics. Therefore, if the amount of titanium oxide fine particles added is larger than the amount of silica fine particles added, this side effect is affected. It can be considered large. However, when the added amount of the hydrophobic silica fine particles and the hydrophobic titanium oxide fine particles is in the range of 0.3 to 1.5 wt%, the charge rising characteristics are not greatly impaired, and the desired charge rising characteristics can be obtained, that is, repeated copying. Stable image quality can be obtained even if

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

2) The toner material liquid is emulsified in an aqueous medium in the presence of a surfactant and resin fine particles.
The aqueous medium may be water alone or an organic solvent such as alcohol (methanol, isopropyl alcohol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.). It may be included.
The amount of the aqueous medium used relative to 100 parts by weight of the toner material liquid is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight. If the amount is less than 50 parts by weight, the dispersion state of the toner material liquid is poor, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 20000 parts by weight, it is not economical.

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

Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount. Preferred anionic surfactants having a fluoroalkyl group include fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [ω-fluoroalkyl (C6-C11 ) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [ω-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carvone Acids and metal salts, perfluoroalkylcarboxylic acids (C7 to C13) and metal salts thereof, perfluoroalkyl (C4 to C12) sulfonic acids and metal salts thereof, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- ( 2-Hydroxyethyl) Perful Olooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. Can be mentioned.
Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101. DS-102 (manufactured by Daikin Industries, Ltd.), Megafac F-110, F-120, F-113, F-191, F-812, F-833 (manufactured by Dainippon Ink, Inc.), Xtop EF-102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fgentent F-100, F150 (manufactured by Neos).

  Further, as the cationic surfactant, aliphatic quaternary ammonium salts such as aliphatic primary, secondary or secondary amine acids having a fluoroalkyl group, and perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salts. , Benzalkonium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (manufactured by Asahi Glass), Florard FC-135 (manufactured by Sumitomo 3M), Unidyne DS-202 (Daikin Industries) Manufactured), MegaFuck F-150, F-824 (Dainippon Ink Co., Ltd.), Xtop EF-132 (Tochem Products), Footgent F-300 (Neos), and the like.

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. Examples thereof include vinyl resins, polyurethane resins, epoxy resins, polyester resins, polyamide resins, polyimide resins, silicon resins, phenol resins, melamine resins, urea resins, aniline resins, ionomer resins, and polycarbonate resins. 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 esters. 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 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 spherical shape and the spindle shape can be controlled, and the surface morphology is also controlled between the smooth shape and the umeboshi shape. Can do.

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 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. The ratio (r2 / r1) (see FIG. 5B) is 0.5 to 1.0, and the ratio of thickness to minor axis (r3 / r2) (see FIG. 5C) is 0.7 to 1.0. It is preferable to be in the range of 1.0. When the ratio of the major axis to the minor axis (r2 / r1) is less than 0.5, the dot reproducibility and transfer efficiency are inferior because of being away from the true spherical shape, and high-quality image quality cannot be obtained. On the other hand, if the ratio of thickness to minor axis (r3 / r2) is less than 0.7, the shape is close to a flat shape, and a high transfer rate like a spherical toner cannot be obtained. In particular, when the ratio of the thickness to the minor axis (r3 / r2) is 1.0, the rotating body has a major axis as a rotation axis, and the fluidity of the toner can be improved.
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.
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, and if it exceeds 100 μm, the miscibility with the toner is low and the charge amount of the toner is insufficient, resulting in poor charging during continuous use. Cheap. In addition, Cu ferrite containing Zn is preferable because of its high saturation magnetization, but can be appropriately selected according to the process of the image forming apparatus 100. The resin for coating the magnetic carrier is not particularly limited, and examples thereof include silicone resin, styrene-acrylic resin, fluorine-containing resin, and olefin resin. 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.

1 is a schematic configuration diagram of an image forming apparatus according to the present invention. It is a flowchart which shows an example of lubricant application control. It is a figure which shows the relationship between the rotation time of a brush roller, and the consumption of a lubricant. FIG. 3 is a diagram schematically illustrating a toner shape. FIG. 3 is a schematic view illustrating an outer shape of toner.

Explanation of symbols

1 Latent image carrier (photoreceptor)
2 charging device 2a charging roller 2b charging roller cleaning member 4 developing device 4a developer carrier 5 transfer device 6 cleaning device 61 cleaning blade 62 lubricant application means (brush roller)
63 Flicker 64 Solid lubricant

Claims (17)

An image carrier for carrying a latent image;
Charging means for uniformly charging the surface of the image carrier;
Exposure means for exposing the surface of the charged image carrier based on image data and writing a latent image;
Developing means for supplying a toner to the latent image formed on the surface of the image bearing member to visualize the latent image;
Image area calculating means for calculating the image area of the visible image;
Image area ratio calculating means for the traveling area of the image carrier of this image area,
Transfer means for transferring a visible image on the surface of the image carrier to a transfer medium;
In an image forming apparatus provided with a cleaning unit that cleans the surface of the image carrier after transfer and applies a lubricant to the surface of the image carrier through a fur brush.
An image forming apparatus comprising: an adjusting unit that adjusts an amount of a lubricant applied to the surface of the image carrier according to an image area ratio of a visible image on the surface of the image carrier. The image forming apparatus according to claim 1.
An image forming apparatus, wherein the adjusting means adjusts the amount of lubricant by adjusting the number of rotations of a rotatable brush roller. The image forming apparatus according to claim 1, wherein
An image forming apparatus, wherein the adjusting means adjusts the amount of lubricant by adjusting a rotation time of a rotatable brush roller. The image forming apparatus according to claim 1, wherein
After finishing the developing operation for the latent image corresponding to the previous transfer paper in one print job after supplying the lubricant, the lubricant is applied to the image carrier before starting the developing operation for the next transfer paper. An image forming apparatus. The image forming apparatus according to claim 1 or 3,
An image forming apparatus, wherein the lubricant is supplied to the image carrier between the print job and the supply of the lubricant. The image forming apparatus according to claim 1,
The image forming apparatus according to claim 1, wherein the cleaning unit is a cleaning blade that is positioned downstream of the contact position between the image carrier and the brush roller in the rotation direction of the image carrier and is in contact with the image carrier. The image forming apparatus according to claim 6.
The image forming apparatus, wherein the cleaning blade has a bending stiffness of 300 mN (measurement conditions: 5 mm, 5 °) or more. The image forming apparatus according to claim 6 or 7,
The image forming apparatus, wherein the cleaning blade has a JIS-A hardness of 60 or more. The image forming apparatus according to claim 1,
An image forming apparatus comprising: a process cartridge that is integrally supported and includes at least the image carrier and the cleaning unit and is detachably formed on a main body of the image forming apparatus. The image forming apparatus according to claim 1,
The toner has a weight average particle diameter of 10 μm or less, and a ratio (dispersity) between the weight average particle diameter and the number average particle diameter is in the range of 1.00 to 1.40. . The image forming apparatus according to claim 1,
The image forming apparatus, wherein the toner has an average circularity in a range of 0.95 to 1.00. The image forming apparatus according to claim 1,
The toner has a substantially spherical appearance,
The ratio of the major axis to the minor axis (r2 / r1) is in the range of 0.5 to 1.0, and the ratio of the thickness to the minor axis (r3 / r2) is in the range of 0.7 to 1.0. An image forming apparatus characterized by satisfying a relationship of major axis r1 ≧ minor axis r2 ≧ thickness r3. The image forming apparatus according to claim 1,
In the toner, a toner material solution in which at least a polyester prepolymer having a functional group containing a nitrogen atom, polyester, a colorant, and a release agent is dissolved or dispersed in an organic solvent is crosslinked and / or dispersed in an aqueous medium. Alternatively, an image forming apparatus characterized by causing an extension reaction. A toner used in the image forming apparatus according to claim 1,
A toner having a weight average particle diameter of 10 μm or less and a ratio (dispersity) of the weight average particle diameter to the number average particle diameter in the range of 1.00 to 1.40. The toner according to claim 14.
The toner has an average circularity in a range of 0.95 to 1.00. The toner according to claim 14 or 15,
The appearance of the toner is almost spherical,
The ratio of the major axis to the minor axis (r2 / r1) is in the range of 0.5 to 1.0, and the ratio of the thickness to the minor axis (r3 / r2) is in the range of 0.7 to 1.0. And a toner satisfying the relationship of major axis r1 ≧ minor axis r2 ≧ thickness r3. The toner according to any one of claims 14 to 16,
The toner is obtained by crosslinking and / or crosslinking a toner material solution obtained by dissolving or dispersing at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent in an organic solvent in an aqueous medium. A toner characterized by an extension reaction.

Images