JP2006058748A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of printing a high-quality image by effectively removing a transfer residual toner on a photoreceptor with a cleaning blade thereby preventing filming. <P>SOLUTION: The image forming apparatus is equipped with a particulate supply means 80 to deposit fine particles having 50 to 500 nm average particle size onto a photoreceptor 40 in a period after the toner is supplied to a latent image formed on the surface of the photoreceptor 40 to visualize the image until the visualized image on the surface of the photoreceptor 40 is transferred to a transfer medium and the transfer residual toner touches a cleaning blade 71. <P>COPYRIGHT: (C)2006,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.

An image forming apparatus using an electrophotographic process develops an electrostatic latent image formed on an image carrier such as a photoconductor with toner, and then the toner is transferred from the photoconductor to a transfer medium such as transfer paper in a transfer process. After that, the image is fixed on the paper surface in the fixing step. In the transfer process, a small amount of toner remains on the photoconductor, and cleaning is performed to remove the toner. For this photoconductor cleaning, a blade cleaning method that is small and low in cost is often used.
Further, in order to improve the image quality, the toner has been 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. The wear of the blade is accelerated by the slipped toner, and the life of the blade is shortened, or the slipped toner adheres to the photosensitive member and the charging roller and causes filming, resulting in an abnormal image.

  In the blade cleaning method of an image forming apparatus using a toner having a high degree of circularity, as described in Patent Documents 1 and 2, a lubricant is mixed with a developer, and the non-deformation is performed according to the image area ratio on the photoconductor. In some cases, a developer is applied to the photoconductor during printing to reduce the friction coefficient, thereby preventing slipping through and improving the cleaning property. However, the above method has problems such as affecting performance when printing is temporarily stopped and performing the above operation in a non-printing state, or requiring a mechanism for uniformly mixing the lubricant with the developer. It was.

JP 2003-241570 A JP 2004-37771 A

  In view of the above problems, it is an object of the present invention to provide an image forming apparatus that can effectively remove a transfer residual toner on a photoreceptor with a cleaning blade, prevent filming, and print a high-quality image. And

  In order to solve the above-described problems, the invention described in claim 1 is directed to an image carrier that carries a latent image, a charging unit that uniformly charges the surface of the image carrier, and an image on the surface of the charged image carrier. An exposure unit that performs exposure based on 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 a visible image on the surface of the image carrier are transferred In an image forming apparatus comprising: transfer means for transferring to a medium; and cleaning means for cleaning the surface of the image carrier after transfer, the cleaning means having at least a cleaning blade for removing toner on the image carrier. After developing to supply toner to the latent image formed on the surface of the image carrier and making it visible, the visible image on the surface of the image carrier is transferred to a transfer medium until the transfer residual toner contacts the cleaning blade. In between, statue An image forming apparatus comprising: a particulate supply means to attach the particulates in the lifting body.

A second aspect of the present invention is the image forming apparatus according to the first aspect, wherein the fine particles are fine particles having an average particle diameter of 50 to 500 nm.
A third aspect of the present invention is the image forming apparatus according to the first or second aspect, wherein the fine particles are inorganic fine particles.
A fourth aspect of the present invention is the image forming apparatus according to the first or second aspect, wherein the fine particles are organic fine particles.
According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects, the image forming apparatus includes a lubricant applying unit in which the fine particle supplying unit applies a solid lubricant to the surface of the image carrier. In the image forming apparatus, the fine particles are contained in a lubricant applied to the surface of the image carrier.
The invention according to claim 6 is the image forming apparatus according to any one of claims 1 to 5, wherein the toner has a polyester prepolymer having at least a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent. An image forming apparatus characterized by using a toner that crosslinks and / or extends in a water-based medium in the presence of resin fine particles.
A seventh aspect of the present invention is the image forming apparatus according to the sixth aspect, wherein the toner uses a toner having an average circularity in a range of 0.93 to 1.00. It is.
According to an eighth aspect of the present invention, in the image forming apparatus according to the sixth or seventh aspect, the toner has a volume average particle size to number average particle size ratio (dispersity) of 1.00 to 1. An image forming apparatus characterized by being in the range of 40.

According to a ninth aspect of the present invention, in the image forming apparatus according to any one of the sixth to eighth aspects, the toner has a substantially spherical appearance, and a 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 thickness to minor axis (r3 / r2) is in the range of 0.7 to 1.0, where major axis r1 ≧ minor axis r2 ≧ thickness. The image forming apparatus satisfies the relationship r3.
A tenth aspect of the present invention is a toner used in the image forming apparatus according to any one of the first to fifth aspects, wherein the toner includes a polyester prepolymer having at least a functional group containing a nitrogen atom, a polyester And a toner composition comprising a colorant and a release agent, and a crosslinking and / or elongation reaction in an aqueous medium in the presence of resin fine particles.
The invention described in claim 11 is the toner according to claim 10, wherein the toner has an average circularity in the range of 0.93 to 1.00.
According to a twelfth aspect of the present invention, in the toner according to the tenth or eleventh aspect, the ratio (dispersity) of the volume average particle diameter to the number average particle diameter is in the range of 1.00 to 1.40. The toner is characterized by the following.
According to a thirteenth aspect of the present invention, in the toner according to any one of the tenth to twelfth aspects, the toner has a substantially spherical appearance and has a ratio (r2 / r1) between the major axis and the minor axis. In the range of 0.5 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 The toner satisfies the following conditions.

  According to the present invention, it is possible to provide an image forming apparatus capable of effectively removing a transfer residual toner on a photoreceptor with a cleaning blade, preventing filming, and printing a high-quality image.

  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 a person 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. In the figure, reference numeral 100 is a copying apparatus main body, 200 is a paper feed table on which the copying apparatus is placed, 300 is a scanner mounted on the copying apparatus main body 100, and 400 is an automatic document feeder (ADF) mounted thereon.
The copying apparatus main body 100 has a tandem type in which four image forming units 18 each having various units for performing an electrophotographic process such as charging, developing, and cleaning are arranged in parallel around a photosensitive member 40 as a latent image carrier. An image forming apparatus 20 is provided. Above the tandem image forming apparatus 20, there is provided an exposure apparatus 21 that exposes the photoreceptor 40 with laser light based on image information to form a latent image. Further, an intermediate transfer belt 10 made of an endless belt member is provided at a position facing each photoconductor 40 of the tandem type image forming apparatus 20. A primary transfer unit 62 for transferring the toner images of the respective colors formed on the photoconductor 40 to the intermediate transfer belt 10 is disposed at a position facing the photoconductor 40 via the intermediate transfer belt 10.

A secondary transfer device 22 that collectively transfers the toner images superimposed on the intermediate transfer belt 10 onto transfer paper conveyed from the paper feed table 200 is disposed below the intermediate transfer belt 10. The secondary transfer device 22 is configured by spanning a secondary transfer belt 24 that is an endless belt between two rollers 23, and is disposed by pressing against the support roller 16 via the intermediate transfer belt 10. The toner image on 10 is transferred onto a transfer sheet. A fixing device 25 for fixing the image on the transfer paper is provided beside the secondary transfer device 22. The configuration of the fixing device 25 will be described in detail later.
The secondary transfer device 22 described above also has a sheet transport function for transporting the transfer paper after image transfer to the fixing device 25. Of course, a transfer roller or a non-contact charger may be arranged as the secondary transfer device 22, and in such a case, it is difficult to provide this sheet conveyance function together.
In the illustrated example, a reversing device 28 for reversing the transfer paper so as to record images on both sides of the transfer paper is provided below the secondary transfer device 22 and the fixing device 25 in parallel with the tandem image forming device 20 described above. .

The operation of the image forming apparatus is as follows.
First, a document is set on the document table 30 of the automatic document feeder 400, or the automatic document feeder 400 is opened and a document is set on the contact glass 32 of the scanner 300, and the automatic document feeder 400 is closed. Hold it down.
When a start switch (not shown) is pressed, when the document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32, and then the document is set on the other contact glass 32. At that time, the scanner 300 is immediately driven to travel the first traveling body 33 and the second traveling body 34. Then, the first traveling body 33 emits light from the light source and further reflects the reflected light from the document surface toward the second traveling body 34 and reflects by the mirror of the second traveling body 34 and passes through the imaging lens 35. The document is placed in the reading sensor 36 and the original content is read.

  When a start switch (not shown) is pressed, one of the support rollers 14, 15 and 16 is rotationally driven by a drive motor (not shown), the other two support rollers are driven to rotate, and the intermediate transfer belt 10 is rotated and conveyed. To do. At the same time, the individual image forming means 18 rotates the photoconductor 40 to form black, yellow, magenta, and cyan monochrome images on each photoconductor 40. Then, along with the conveyance of the intermediate transfer belt 10, the monochrome images are sequentially transferred to form a composite color image on the intermediate transfer belt 10.

On the other hand, when a start switch (not shown) is pressed, one of the paper feed rollers 42 of the paper feed table 200 is selectively rotated, and the sheet is fed out from one of the paper feed cassettes 44 provided in multiple stages in the paper bank 43, and the separation roller 45. Then, the sheets are separated one by one into the paper feed path 46, transported by the transport roller 47, guided to the paper feed path 48 in the copying machine main body 100, and abutted against the registration roller 49 and stopped.
Alternatively, the sheet feed roller 50 is rotated to feed out the sheets on the manual feed tray 51, separated one by one by the separation roller 52, put into the manual feed path 53, and abutted against the registration roller 49 and stopped.
Then, the registration roller 49 is rotated in synchronization with the composite color image on the intermediate transfer belt 10, the sheet is fed between the intermediate transfer belt 10 and the secondary transfer device 22, and is transferred by the secondary transfer device 22. A color image is recorded on the sheet.

The image-transferred sheet is conveyed by the secondary transfer device 22 and sent to the fixing device 25. The fixing device 25 applies heat and pressure to fix the transferred image, and then the switching roller 55 is used to switch the discharge image. The paper is discharged at 56 and stacked on the paper discharge tray 57. Alternatively, it is switched by the switching claw 55 and put into the sheet reversing device 28, where it is reversed and guided again to the transfer position, and the image is recorded also on the back surface, and then discharged onto the discharge tray 57 by the discharge roller 56.
On the other hand, the intermediate transfer belt 10 after the image transfer is removed by the intermediate transfer belt cleaning device 17 to remove residual toner remaining on the intermediate transfer belt 10 after the image transfer, so that the tandem image forming apparatus 20 can prepare for the image formation again.

FIG. 2 is a schematic diagram showing the configuration around the photoreceptor. A photosensitive member 40 on which an electrostatic latent image is formed, a charging device 60 that charges the surface of the photosensitive member 40, and a developing device that supplies toner to the latent image formed on the surface of the photosensitive member 40 to make a visible image. 4, a cleaning blade 71 that cleans the surface of the photoconductor 40, a fine particle supply unit 80, and a brush-like roller 91.
The photoconductor 40 can be made of amorphous metal having photoconductivity, amorphous metal such as amorphous selenium, or organic compound such as bisazo pigment or phthalocyanine pigment.
The developing device 4 includes a developing roller facing the photoconductor 40, a screw for conveying and stirring the developer, a toner concentration sensor, and the like. The developing roller is composed of an outer rotatable sleeve and an inner magnet. In accordance with the output of the toner density sensor, toner is supplied from the toner supply device. In this embodiment, a two-component developer composed of toner and carrier is used as the developer.
The charging roller 61 in the charging device 60 is conductive or semiconductive, and applies a DC and / or AC voltage to apply a charge on the photoconductor 40 to charge the photoconductor 40. A charging roller cleaning brush 62 for cleaning the roller surface is in contact with the charging roller 61. In this embodiment, since there is no contact, the applied bias is obtained by superimposing an AC voltage on a DC voltage in consideration of a variation in charging potential due to a minute gap variation, discharge stability, and the like.

  A cleaning blade 71 is in contact with the photoreceptor 40, a particulate supply means 80 for supplying particulates onto the photoreceptor on the upstream side in the rotational direction of the photoreceptor 40 with respect to the cleaning blade 71, and a brush-like roller 91 on the further upstream. Has been placed. The toner remaining on the photoreceptor 40 after the primary transfer is completed is first recovered from the photoreceptor 40 by the brush-like roller 91. Subsequently, fine particles are supplied onto the photosensitive member 40 by the fine particle supply means 80, and toner, filming, etc. remaining on the photosensitive member 40 are finally scraped off by the cleaning blade 71.

The brush-like roller 91 can use fibers selected from polyamide resins such as styrene resin, acrylic resin, polyester resin, fluororesin, and nylon. In particular, a polyamide resin and a polyester resin that are resistant to wear are good, and it is preferable that the conductive powder is not contained and that the insulating property be maintained. Specifically, the electric resistance is set to 10 ¹² Ωcm or more. In the case of conductivity, the charged toner is attracted to the brush with a mirror image force, so that it is difficult to separate even with the brush-shaped roller scraper 92. By making the brush insulative, it is easy to scrape off the toner from the brush-like roller 91 and to make it easy to separate by the brush-like roller scraper 92, thereby speeding up the collection of the cleaned toner.

If the resilience elastic modulus at 10 ° C. to 40 ° C. is 40% or less, the cleaning blade 71 is less likely to cause squealing and chattering. Further, the wear of the photoreceptor is reduced. It is considered that since the rebound resilience is small, so-called stick-slip at the contact portion of the photosensitive member is reduced and wear is reduced. Further, if the bending stiffness at a distance of 5 mm from the fulcrum when the cleaning blade 71 is bent 5 degrees is 400 mN or more, the cleaning performance is improved. 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. As the JIS-A hardness of the cleaning blade 71 is lowered, the blade that is in contact with the photosensitive member is likely to be deformed, and the contact area of the blade is increased due to an increase in the contact area of the blade. The ability to prevent slipping 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.
The material for forming the cleaning blade 71 is not particularly limited as long as it is urethane rubber.

  Next, the fine particle supply means 80 will be described in detail. The fine particle supply means 80 includes a fine particle application brush 82 and a hollow roller 81 (hereinafter referred to as a supply roller). A supply roller 81 is provided so as to be in contact with the fine particle application brush 82, and rotates with the rotation of the fine particle application brush 82. Fine particles are put in the hollow portion of the supply roller 81, and fine holes are provided on the surface of the supply roller 81 so as to communicate with the hollow portion. It adheres to the fine particle application brush 82 and is applied to the surface of the photoreceptor. The holes on the surface of the supply roller 81 may be limited to a part in the circumferential direction instead of reducing the hole diameter on the surface or having holes in the entire circumferential direction in order to prevent excessive supply. Further, the supply roller 81 may be formed of a mesh mesh instead of a metal cylinder. Furthermore, the supply roller 81 may not be rotated, and the supply roller 81 may be vibrated by the contact rotation of the particle application brush 82 so that the particles fly from the inside.

The fine particles are fine particles having an average particle diameter of 50 to 500 nm, and may be either inorganic fine particles or organic fine particles. When the average particle diameter is less than 50 nm, the cleaning blade slips through, so that the damming effect of the cleaning blade cannot be obtained. On the other hand, if it exceeds 500 nm, the frictional force due to contact with the photoreceptor increases, and the cleaning blade is likely to be damaged by slipping through the cleaning blade.
As inorganic fine particles, SiO ₂ , TiO ₂ , Al ₂ O ₃ , MgO, CuO, ZnO, SnO ₂ , CeO ₂ , Fe ₂ O ₃ , BaO, CaO, K ₂ O, Na ₂ O, ZrO ₂ , CaO.SiO ₂ , K ₂ O (TiO ₂ ) n, Al ₂ O ₃ .2SiO ₂ , CaCO ₃ , MgCO ₃ , BaSO ₄ , MgSO ₄ , SrTiO _{3 and the} like can be exemplified, preferably SiO ₂ , Examples thereof include TiO ₂ and Al ₂ O ₃ .
As the organic fine particles, a resin compound is preferable, and any resin can be used as long as it is a resin capable of forming an aqueous dispersion. For example, a vinyl resin, a polyurethane resin, an epoxy resin, a polyester may be used. Examples thereof include resins, polyamide resins, polyimide resins, silicon resins, phenol resins, melamine resins, urea resins, aniline resins, ionomer resins, and polycarbonate resins. As the resin fine particles, 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.
Vinyl resins are polymers obtained by homopolymerization or copolymerization of vinyl monomers, such as styrene- (meth) acrylic acid ester copolymers, styrene-butadiene copolymers, (meth) acrylic acid-acrylic acid ester copolymers. Examples thereof include a polymer, a styrene-acrylonitrile copolymer, a styrene-maleic anhydride copolymer, and a styrene- (meth) acrylic acid copolymer.

  Since the average particle diameter of these fine particles is 50 to 500 nm, the fine particles are deposited on the edge portion of the cleaning blade 71 to bring about the effect of clogging the transfer residual toner, and the toner remaining after the transfer is effectively removed by the cleaning blade 71. And the toner can be prevented from slipping through the cleaning blade 71. Furthermore, even a spherical toner that is difficult to clean can be cleaned. The fine particle supply means 80 may be disposed anywhere after the development as long as it is between the contact position of the photoreceptor 40 and the cleaning blade 71.

  The fine particles may be applied to the surface of the photoreceptor 40 using the fine particles as a lubricant molded body. FIG. 3 is a schematic diagram showing a configuration around the photoreceptor provided with a lubricant application unit. The lubricant application unit 95 is disposed upstream of the cleaning blade 71 in the rotation direction of the photoconductor 40, and also has a function as a toner removing unit. The toner remaining on the photoconductor 40 after the primary transfer is finished is first recovered from the photoconductor 40 by the brush roller 96. Subsequently, the fine particles contained in the solid lubricant 97 are supplied onto the photoconductor 40, and the toner remaining on the photoconductor 40 is scraped off by the cleaning blade 71.

The image forming apparatus that can obtain the effect of mounting the fine particle supply means 80 of the present invention is a case where the toner used in the developing device is a toner having a high degree of circularity with an average circularity of 0.93 or more.
Therefore, by providing the fine particle supply means 80 of the present invention, the cleaning blade 71 can efficiently clean the surface of the photoreceptor 40 as described below even when using the toner having a high average circularity as described above. can do. That is, the residual toner on the photoconductor 40 is first collected by the brush roller 91, and then fine particles are applied to the surface of the photoconductor 40 by the fine particle supply means 80, and finally remain on the photoconductor by the cleaning blade 71. The toner is blocked and scraped off and removed. Cleaning can be performed efficiently without damaging the surface of the photoreceptor 40.

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 SF-2 value increases, the unevenness of the toner surface becomes more prominent.
Specifically, the shape factor is measured by taking a photograph of the toner with a scanning electron microscope (S-800: manufactured by Hitachi, Ltd.), introducing it into an image analyzer (LUSEX 3: manufactured by Nireco), and analyzing it. Calculated.
When the shape of the toner is close to a sphere, the contact point between the toner and the toner or the toner and the photosensitive member is brought into contact, so that the adsorbing force between the toners is weakened and the fluidity is increased. The attractive force is also weakened and the transfer rate is increased. On the other hand, as described above, spherical toner tends to cause poor cleaning in blade type cleaning, but by using the fine particle supply means of the present invention, good cleaning can be performed with a cleaning blade. 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 by the conventional blade type cleaning. If 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. However, with the fine particle supply means according to the present invention, the brush roller 161 applies fine particles to the surface of the photoreceptor 5 and the cleaning blade 151 blocks the toner, thereby preventing slipping through and improving the cleaning performance.

  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 is deteriorated. 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, and rice wax, animal waxes such as beeswax and lanolin, mineral waxes such as ozokerite and cercin, and paraffin, microcrystalline, And petroleum waxes such as petrolatum. In addition to these natural waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax and polyethylene wax, and synthetic waxes such as esters, ketones, and ethers can be used. Furthermore, fatty acid amides such as 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide, chlorinated hydrocarbon, and low molecular weight crystalline polymer resin, poly-n-stearyl methacrylate, poly-n- A crystalline polymer having a long alkyl group in the side chain such as a homopolymer or copolymer of polyacrylate such as lauryl methacrylate (for example, a copolymer of n-stearyl acrylate-ethyl methacrylate, etc.) can also be used. .
The charge control agent and the release agent can be melt-kneaded together with the master batch and the binder resin, and of course, they may be added when dissolved and dispersed in the organic solvent.

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

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

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

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

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

  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 of the isocyanate group structure of the polyester prepolymer (A) with the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 24 hours. The reaction temperature is generally 0 to 150 ° C, preferably 40 to 98 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.

4) After completion of the reaction, the organic solvent is removed from the emulsified dispersion (reactant), washed and dried to obtain toner base particles.
In order to remove the organic solvent, the temperature of the entire system is gradually raised in a laminar stirring state, and after giving strong stirring in a certain temperature range, the solvent base is removed to produce spindle-shaped toner base particles. . Further, when an acid such as calcium phosphate salt or an alkali-soluble material is used as the dispersion stabilizer, the calcium phosphate salt is dissolved from the toner base particles by a method such as 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. Further, although Cu ferrite containing Zn is preferable because of high saturation magnetization, it can be appropriately selected according to the process of the image forming apparatus 1. 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. FIG. 2 is a schematic diagram illustrating a configuration around a photoconductor. It is the schematic which shows the structure of a photoreceptor periphery provided with a lubricant application means. FIG. 3 is a diagram schematically illustrating a toner shape. FIG. 3 is a schematic diagram illustrating an outer shape of a toner.

Explanation of symbols

4 Developing device 10 Intermediate transfer belt (intermediate transfer member)
18 Image forming means 21 Exposure device 22 Secondary transfer device 25 Fixing device 251 Heating roller 252 Fixing roller 253 Belt (toner heating member)
254 Pressure roller 40 Photosensitive member (latent image carrier)
60 Charging Device 61 Charging Roller 62 Primary Transfer Unit 71 Cleaning Blade 80 Particle Supply Device (Particle Supply Unit)
81 Supply Roller 82 Fine Particle Application Roller 83 Fine Particle 91 Brush Roller 92 Brush Roller Scraper 95 Lubricant Application Means 96 Brush Roller 97 Solid Lubricant 100 Copier Main Body 200 Paper Feed Table 300 Scanner 400 Automatic Document Conveyance Device

Claims (13)

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;
Transfer means for transferring a visible image on the surface of the image carrier to a transfer medium;
In an image forming apparatus comprising: cleaning means for cleaning the surface of an image carrier after transfer, and at least a cleaning means having a cleaning blade for removing toner on the image carrier.
After developing to supply toner to the latent image formed on the surface of the image carrier and making it visible, the visible image on the surface of the image carrier is transferred to a transfer medium until the transfer residual toner contacts the cleaning blade. An image forming apparatus comprising: a fine particle supply unit for attaching fine particles to the image carrier. The image forming apparatus according to claim 1.
The image forming apparatus, wherein the fine particles are fine particles having an average particle diameter of 50 to 500 nm. The image forming apparatus according to claim 1, wherein
The image forming apparatus, wherein the fine particles are inorganic fine particles. The image forming apparatus according to claim 1, wherein
The image forming apparatus, wherein the fine particles are organic fine particles. The image forming apparatus according to claim 1,
In the image forming apparatus, the fine particle supplying means is a lubricant applying means for applying a solid lubricant to the surface of the image carrier, and the fine particles are included in the lubricant applied to the surface of the image carrier. Forming equipment. The image forming apparatus according to claim 1,
A toner in which the toner comprises a toner composition containing at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent in a water-based medium in the presence of resin fine particles. An image forming apparatus comprising: The image forming apparatus according to claim 6.
An image forming apparatus comprising: a toner having an average circularity in a range of 0.93 to 1.00. The image forming apparatus according to claim 6 or 7,
The image forming apparatus, wherein the toner has a ratio (dispersity) of a volume average particle diameter to a number average particle diameter in a range of 1.00 to 1.40. The image forming apparatus according to any one of claims 6 to 8,
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. A toner used in the image forming apparatus according to claim 1,
A toner composition containing at least a polyester prepolymer having a functional group containing a nitrogen atom, polyester, a colorant, and a release agent is crosslinked and / or extended in the presence of resin fine particles in an aqueous medium. Toner. The toner according to claim 10.
The toner has an average circularity in a range of 0.93 to 1.00. The toner according to claim 10 or 11,
A toner having a ratio of volume average particle diameter to number average particle diameter (dispersity) in the range of 1.00 to 1.40. The toner according to any one of claims 10 to 12,
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.

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