JP2006201648A - Toner and developer comprising the toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner excellent in filming resistance on a photoreceptor, capable of forming a clear image of high and uniform density with a small toner amount, and capable of achieving miniaturization of an image forming apparatus by miniaturization of a developing device, a developer based on the toner and a developing method using the toner or the developer. <P>SOLUTION: The toner includes at least a binder resin and a colorant and has a predetermined average particle diameter. The developer consists essentially of the toner and an iron oxide. The developing method utilizes the toner or the developer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a toner used for developing a latent image such as an electrical latent image or a magnetic latent image in an image forming apparatus such as an electrophotographic system or a magnetic printing system, a developer containing the toner as a main component, and The present invention relates to a developing method using the toner or the developer.

  Electrophotographic image forming apparatuses are frequently used as copying machines or printers. An electrophotographic image forming apparatus forms an image through the following electrophotographic process. First, a photosensitive layer of an electrophotographic photosensitive member (hereinafter also simply referred to as a photosensitive member) provided in the apparatus is uniformly charged to a predetermined potential by a charging unit, exposed according to image information by an exposure unit, and electrostatic latent images are obtained. Form an image. A developer is supplied from the developing device to the formed electrostatic latent image, and the electrostatic latent image is developed by attaching fine particles called toner, which is a component of the developer, to the surface of the photosensitive member, and as a toner image Visualize. The formed toner image is transferred from the surface of the photoreceptor to a transfer medium such as recording paper by a transfer unit, and fixed by a fixing device.

  In recent years, in the field of electrophotographic image forming apparatuses, developments have been made with the aim of downsizing, speeding up, and improving image quality of the apparatus. As for downsizing of image forming apparatuses, downsizing of apparatuses used in each process of electrophotographic processes including developing devices and fixing devices is being studied. For example, in developing devices, reduction of the capacity and long life of a developer filling part such as a toner hopper is being studied. To realize these, development of a toner capable of forming many images with a small amount of toner Is desired.

  2. Description of the Related Art Conventionally, as a developing device, a two-component developing type developing device that performs development using a two-component developer obtained by mixing a carrier that is magnetic powder and toner is used. However, in the two-component development type developing device, both a developer filling unit for containing the developer and a replenishment toner filling unit for containing the toner to be replenished to the developer filling unit are required. Even if the capacity is reduced, the developing device itself cannot be reduced in size. Further, in order to keep the developing density constant, it is necessary to keep the mixing ratio of the toner and the carrier constant, so that the configuration of the entire developing device becomes complicated and various restrictions are imposed on miniaturization.

  In image forming apparatuses, a so-called oilless fixing apparatus that fixes an image on a transfer medium without applying a release agent such as oil to a fixing member is often used as a fixing apparatus. A fixing device having a function of applying a release agent to a fixing member requires a complicated mechanism such as a release agent supply unit, a release agent application roller, and a release agent collecting / circulating device. There is a problem that the inside of the fixing device is contaminated due to leakage and scattering of the agent. By adopting an oilless fixing device, these problems can be solved, and a simple mechanism can be designed. However, in the image forming apparatus using the oil-less fixing device, a part of the toner melted at the time of fixing adheres to the fixing member, and a so-called offset phenomenon occurs in which the attached matter is transferred to a subsequent transfer medium. There is a problem that the transfer medium is wound around the fixing member. Further, when the oilless fixing device is used in a color image forming apparatus, there arises a problem that the color development property and glossiness of the formed image toner layer are insufficient. Therefore, the toner used in the image forming apparatus employing the oilless fixing device does not cause the offset phenomenon and the wrapping of the transfer medium around the fixing member, and the color development property and glossiness of the formed image toner layer. It is required to be excellent.

  As a toner suitable for an image forming apparatus employing an oil-less fixing device, a toner containing a large amount of waxes for the purpose of imparting a release effect from a fixing member and a gloss feeling of a formed image, sufficient toner For the purpose of enhancing the color developability by securing a molten state, those containing a low melting point resin have been proposed. However, when these toners are used as a non-magnetic one-component developer, they are fused to the developing blade and filmed on the photoreceptor due to waxes added to the toner. There is a problem of doing. For example, when these toners are used in a developing device of a contact one-component developing system that performs development by bringing a developing roller into contact with the photosensitive member, thermally fragile components such as wax in the toner are present on the surface of the photosensitive member. Filming occurs due to fusion. In particular, when the content of the wax is large, a large amount of filming occurs on the photoreceptor, and the quality deteriorates due to storage in a high-temperature environment such as a developer filling portion. Therefore, further improvement is desired for the toner used in the image forming apparatus including the oilless fixing device.

  Further, from the viewpoint of improving the image quality of the formed image, a toner capable of obtaining a desired image density with an extremely thin toner layer is required. For example, in a lithographic image formed using ink, which is a liquid recording material, the ink penetrates into the print medium, and no layer of the recording material is formed on the print medium. Become. On the other hand, when a full color image is formed by an electrophotographic image forming apparatus, usually three process color toners of yellow, magenta and cyan and black toner are used, and various colors can be obtained by combining them. Since the reproduction is performed, the thickness of the recording material layer, that is, the toner layer on the transfer medium differs depending on the reproduced color. For this reason, in the electrophotographic image, the amount of light reflected by the toner layer differs for each color, and the difference from the flat print image is felt due to the difference in the amount of reflected light. Therefore, in order to obtain a uniform and clear high-quality image in the electrophotographic system, it is necessary to obtain a desired image density with an extremely thin toner layer.

  As a color toner satisfying such requirements, a color toner having a weight average particle diameter of 3 to 7 μm, 10 to 70% by weight of color toner particles having a particle diameter of 4.00 μm or less, and a particle diameter of 5.04 μm or less. Specific particle size distribution containing 40% by number or more of particles, 2 to 20% by volume of color toner particles having a particle size of 8.00 μm or more, and less than 6% by volume of color toner particles having a particle size of 10.08 μm or more There has been proposed a color toner having a specific coloring power (see Patent Document 1). In Patent Document 1, the above-described color toner having a specific particle size distribution and coloring power does not cause a decrease in image density and blurring even when a color original having a large image area is continuously copied. Have excellent image characteristics and excellent durability stability. Further, in Patent Document 1, when producing a color toner having the specific particle size distribution and coloring power described above, a coloring power of 0.5 to 12 parts by weight is used with respect to 100 parts by weight of the binder resin. It is disclosed that a color toner having a high image density and a high image density can be obtained.

  When the color toner disclosed in Patent Document 1 is mixed with a carrier and used as a two-component developer, it is excellent in gradation and sharpness when continuously copying a color document having a large image area. In addition, although it is possible to realize an image having a high image density, since it contains a large amount of small particle size particles having a particle size of 4.00 μm or less, it is developed when used as a non-magnetic one-component developer. There is a problem that fusion to the agent regulating member (developing blade) is likely to occur. In particular, when a release agent such as wax is contained in the toner, the fusion to the developing blade and the filming on the photosensitive member are remarkable. Further, fine particles having a particle size of 4.00 μm or less cannot be sufficiently charged by a developer regulating member (developing blade) or a developing roller. Therefore, the color toner disclosed in Patent Document 1 has poor charging stability, and toner There is also a problem in that scattering is likely to occur and image fogging due to the scattered toner is likely to occur. Therefore, when the color toner disclosed in Patent Document 1 is used, it is difficult to downsize the image forming apparatus because a one-component developing type developing device and an oilless fixing device cannot be used.

  In recent years, polymerized toner has been increasingly used to improve image quality and reduce toner consumption. However, in an image forming apparatus using polymerized toner, when a predetermined number of copies is reached, it is abrupt. In some cases, the toner scatters and the like, and thereafter, the level changes without changing much.

When continuous copying is performed, the charge amount distribution shifts to the weakly charged side, and the distribution is also broadened, causing toner scattering as the reverse charge and weakly charged toner amount increase. In addition, a transfer phenomenon may be deteriorated, such as a dropout failure with a shift in the charge amount distribution amount.
Various measures have been taken to deal with this phenomenon, but the situation is still insufficient.

  Further, full-color developers are required to have the ability to quickly charge charged toner and continuously develop a wide print area. Further, as the apparatus becomes more compact, the diameter of the developing sleeve is smaller, the amount of the developer is reduced, and the developer carrier is required to further improve the charging ability, extend the life, and improve the image quality.

  Under such circumstances, properties required as a carrier include toner retention, charge imparting ability, and a reduction in particle size for softening the magnetic brush. However, the problem of carrier scattering has always been highlighted as an adverse effect of reducing the particle size, and many countermeasures have been proposed.

Patent Document 2 proposes a carrier and a developer that do not cause image defects due to carrier adhesion in high-speed development.
In Patent Document 2, in order to prevent carrier scattering, the primary particles have a number average primary particle size (Dv) and a volume average primary particle size (Dn) that are uniform in magnetization. However, in the Dv / Dn ratio of 1.0 to 2.0 described in Patent Document 1, carrier scattering could not be prevented with respect to small particle size ferrite having an average particle size of 20 to 45 μm.
That is, in the Example of patent document 2, it is a test by a carrier core particle with an average particle diameter of 65 micrometers, and it is thought that those effects will be reduced with the average particle diameter of 20-45 micrometers which a carrier scattering tends to produce. Furthermore, it is presumed that if the average particle size of the carrier is reduced, the particle size of the raw material configured accordingly needs to be reduced.
There are many proposals regarding the magnetic characteristics and particle size distribution for holding carrier particles in the magnetic brush.

In Patent Document 3, the carrier has a weight average particle size of 35 to 55 μm, less than 22 μm: 0 to 15%, 88 μm or more: 0 to 5%, a specific resin coat is applied, and a magnetization of 70 to 120 emu / m in a magnetic field of 1 kOe. g carriers have been proposed. Certainly, the higher the magnetic characteristics, the better the carrier scattering, but on the other hand, the magnetic brush becomes hard and high-quality soft development becomes difficult.
In addition, there are many reports that the smaller the content on the fine powder side, the better the carrier scattering. However, there are many technical and price issues such as classification technology, yield, etc., and it is difficult to say that the overall performance is satisfactory.
On the other hand, although there are many proposals regarding small particle size carriers, even if the conventional technology for ferrite carriers having an average particle size of 60 μm or more is applied to a ferrite carrier having an average particle size of 20 to 45 μm as an extension line, carrier scattering I couldn't respond enough.
Japanese Patent No. 2992924 JP 9-197721 A JP 2001-27828 A

  In the present invention, the above-mentioned problems of the prior art are improved, charging stability in the developing device, resistance to fusing to each developing member and filming resistance on the photosensitive member are excellent, and with a small amount of toner. A toner capable of forming a uniform, clear image having a high density and capable of downsizing the image forming apparatus by downsizing the developing apparatus, a two-component developer containing the toner as a main component, and the toner It is an object of the present invention to provide a developing method using toner or the two-component developer.

The present invention
(1) A toner containing at least a binder resin and a colorant and having a volume average particle diameter in the range of 4 μm to 9 μm and containing 2.0% by volume or less of toner particles having a particle diameter of 15.0 μm or more. And a toner containing 30% by number or more of toner particles having a particle size of 3.00 μm or less and 10% by number or less of toner particles having a particle size of 1.00 μm or less.
(2) The toner and iron oxide described in (1) above are the main components, the volume average particle size is in the range of 30 to 90 μm, and the magnetization at a magnetic field of 1 kOe is in the range of 65 to 80 emu / g. Resin coating in which the current value of the carrier core material is in the range of 50 to 150 μA, the resin coating is applied, and the coating amount is in the range of 0.1 to 5.0% by weight with respect to the carrier core material Developer composed of carrier.
(3) The toner according to (1) above, which contains a colorant in the range of 5 wt% to 20 wt%.
(4) The toner according to (1) or (3) above, which contains a release agent in the range of 3 to 10% by weight.
(5) In the toner, the toner particles having a particle size of 1.0 μm or less have a circularity of 0.96 or more, and the toner is left in a standard environment (25 ° C., indoor humidity 50%) for 48 hours. The toner according to any one of (1), (3), and (4) above, wherein the water content of the particles is 1.0% or less.
(6) According to any one of the above (1), (3), (4), or (5), which is manufactured using a rotor / stator type wet disperser as one of the manufacturing apparatuses. The toner described.
(7) The developer as described in (2) above, which is manufactured by using a rotor / stator type wet disperser as one of the manufacturing apparatuses.
(8) The device according to any one of (1), (3), (4), (5), or (6) above, wherein the image is visualized by applying a bias voltage comprising a non-alternating component. Development method using toner.
(9) The developing method using the developer according to any one of (2) and (7) above, wherein the image is visualized by applying a bias voltage comprising a non-alternating component.
(10) The bias voltage composed of a direct current component is applied to visualize the image, (1), (3), (4), (5), or (6) Development method.
(11) The developing method according to any one of the above (2) and (7), wherein the image is visualized by applying a bias voltage comprising a direct current component.

  According to the present invention, there is provided a carrier for an electrophotographic developer that achieves a reduction in particle size, solves problems such as carrier scattering, and has excellent image characteristics when used in a full-color developer, and a method for producing the same. Provided.

The present invention will be described in detail below.
First, the toner of the present invention contains at least a binder resin and a colorant, has a volume average particle size of 4 μm or more and 9 μm or less, and contains 2.0% by volume or less of toner particles having a particle size of 15.0 μm or more. In addition, it contains 30% by number or more of toner particles having a particle size of 3.00 μm or less and 10% by number or less of toner particles having a particle size of 1.00 μm or less.

Since the toner of this embodiment has such a specific particle size distribution, when used as a two-component developer, the charging stability in the developing device, the anti-fusing property to each developing member, and the photoreceptor Excellent filming resistance on a recording medium such as
Therefore, by using the toner of this embodiment as a two-component developer, the chargeability of the toner is maintained throughout the life, and the toner is fused to the developing blade, and the recording medium such as the developing roller and the photosensitive member is used. Filming is suppressed.

The toner of the present invention can form a uniform and clear image with a small toner amount and a high density. In order to reduce the capacity and the life of the developer filling portion and to realize the downsizing of the image forming apparatus, it is preferable to reduce the amount of toner used for one image formation. In order to achieve high image quality of the formed image, it is preferable to reduce the thickness of the toner layer of the formed image. Therefore, in order to achieve downsizing of the image forming apparatus and high image quality of the formed image, the toner adhesion amount in the monochromatic solid portion of the unfixed toner image formed on the recording medium by development and transferred onto the transfer medium Is preferably 0.5 mg / cm ² or less.
However, when an image is formed using a conventional toner with a small toner amount of 0.5 mg / cm ² or less, sufficient color development and image density cannot be obtained, and the toner does not sufficiently fill the image area on the transfer medium. It cannot be covered and the saturation decreases.
On the other hand, since the toner of the present invention has the specific particle size distribution described above, even if the toner adhesion amount is reduced to 0.5 mg / cm ² or less, a high density, uniform and clear image is formed. can do.

Hereinafter, the reason why the toner in the present embodiment should be limited to the respective numerical value limiting ranges for the constituent components will be described.
When the content of toner particles having a particle diameter of 1.00 μm or less in the toner exceeds 10% by number, when used as a two-component developer, it is fused to a developer regulating blade, and a developing roller, a photoreceptor, etc. Filming on the recording medium tends to occur.
In addition, since toner particles having a particle size of 1.00 μm or less are difficult to be sufficiently charged, if the content of toner particles having a particle size of 1.00 μm or less in the toner exceeds 10% by number, the charging stability decreases. In addition, toner scattering is likely to occur, and image fogging due to the scattered toner is likely to occur.
Therefore, the content of toner particles having a particle diameter of 1.00 μm or less in the toner is set to 10% by number or less.

Further, if the volume average particle size is less than 4 μm, the image resolution can be sufficiently obtained, but the conditions for obtaining the above particle size distribution at the time of toner production are severe, and the yield is greatly reduced. Get higher.
On the other hand, when the volume average particle size exceeds 9 μm, the image resolution is lowered and the amount of toner attached to the transfer medium is 0.5 mg / cm ² or less as described above to form an image with a small amount of toner. The image area on the transfer medium cannot be sufficiently covered, and the image density is insufficient. Further, in the case of a color toner using a chromatic colorant as a colorant, a significant reduction in saturation occurs. Therefore, the volume average particle size is set to 4 μm or more and 9 μm or less.

Further, when the content of toner particles having a particle size of 15.0 μm or more in the toner exceeds 2.0% by volume, the image resolution is lowered and image unevenness is caused as in the case where the volume average particle size exceeds 9 μm. Cause undesirably.
Therefore, the content of toner particles having a particle diameter of 15.0 μm or more in the toner is set to 2.0% by volume or less.

  Further, when the content of toner particles having a particle diameter of 3.00 μm or less in the toner is less than 30% by number, the resolution and density of the formed image are lowered. In the case of color toners, when an image is formed with a small amount of toner, the saturation of the formed image may not be obtained sufficiently, making it difficult to reproduce halftones. Therefore, the content of toner particles having a particle size of 3.00 μm or less in the toner is set to 30% by number or more.

  As the binder resin of the toner constituent material, a resin selected from a wide range including known resins can be used as long as it serves to bind the constituent components of the toner resin composition to the transfer material. Can be used for both. For example, styrene resin such as polystyrene and polystyrene-acrylic acid ester copolymer, vinyl chloride resin, phenol resin, epoxy resin, polyester resin, polyether polyol resin, polyurethane resin, polyvinyl butyral resin and the like are used. Preferably, a styrene (co) polymer, a polyester polymer, a graft polymer obtained by grafting a vinyl resin to a polyester resin, or a powder mixture of these resins is used as the binder resin. These resins may be those in which incompatible substances having low compatibility with the resin from the synthesis stage, such as crystalline waxes, are finely dispersed in advance. One of these resins may be used alone, or two or more thereof may be mixed and used.

  The styrene-based (co) polymer used as the binder resin in the present invention has a styrene monomer as a main structural unit, preferably a structural unit derived from a styrene-based monomer, ( A chromatogram measured by GPC, comprising a meth) acrylic acid ester monomer or a structural unit derived from a (meth) acrylic acid monomer, having a glass transition temperature (Tg) of 45 ° C. or higher and 75 ° C. or lower. In which the weight average molecular weight (Mw) is 100,000 or more, each having a molecular weight of 3,000 or more and 12,000 or less and a region having a molecular weight of 100,000 or more and at least one maximum value or shoulder, It is preferable that it is a styrene-type (co) polymer whose ratio (Mw / Mn) of Mw and number average molecular weight (Mn) is 15 or more and 100 or less.

  Specific examples of the monomer constituting the styrene-based (co) polymer include the following, but are not limited thereto. Examples of the styrenic monomer include styrene, α-methyl styrene, halogenated styrene, vinyl toluene, 4-sulfonamido styrene, 4-styrene sulfonic acid, and the like. Examples of the (meth) acrylate monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, and isobutyl (meth) acrylate. Octyl (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, Furfuryl (meth) acrylate, hydroxylethyl (meth) acrylate, hydroxybutyl (meth) acrylate, (meth) acrylic acid dimethylaminomethyl ester, (meth) acrylic acid dimethylaminoethyl ester, (meth) acrylic acid 2- Ethylhexyl, 2-chloroethyl (meth) acrylate Etc., and the like.

  As the composition of the monomer in the styrene-based (co) polymer, the content of the styrene-based monomer is 60 to 95 wt%, and the content of the (meth) acrylic acid ester-based monomer is 5 to 40 wt%. Is preferred.

  Moreover, what is illustrated below can also be used as another monomer which comprises a styrene-type (co) polymer. That is, itaconic acid esters such as dimethyl itaconate, dipropyl itaconate, dibutyl itaconate, dioctyl itaconate, diamyl itaconate and the like, maleic acid esters and fumaric acid esters such as straight chain having 1 to 8 carbon atoms or Maleic and fumaric esters with branched alkyl groups, diethyl maleate, dipropyl maleate, dibutyl maleate, dipentyl maleate, dihexyl maleate, heptyl maleate, octyl maleate, ethyl butyl maleate, ethyl octyl maleate, Butyl octyl maleate, butyl hexyl maleate, pentyl octyl maleate, diethyl fumarate, dipropyl fumarate, dibutyl fumarate, dipentyl fumarate, dihexyl fumarate , Heptyl fumarate, octyl fumarate, ethyl butyl fumarate, ethyl octyl fumarate, butyl octyl fumarate, butyl hexyl fumarate, pentyl octyl fumarate, etc., and unsaturated carboxylic acids and unsaturated dicarboxylic acids such as cinnamic acid , Maleic acid, fumaric acid, itaconic acid, 2-vinylnaphthalene, itaconic anhydride, maleic anhydride, acrylamide methyl sulfonic acid, acrylamide ethyl sulfonic acid, acrylamide n-propyl sulfonic acid, acrylamide isopropyl sulfonic acid, acrylamide n- Butyl sulfonic acid, acrylamide s-butyl sulfonic acid, acrylamide t-butyl sulfonic acid, acrylamide pentane sulfonic acid, acrylamide hexane sulfonic acid, acrylamide Butanesulfonic acid, acrylamide octane sulfonic acid, methacrylamide methyl sulfonic acid, methacrylamide ethyl sulfonic acid, methacrylamide n-propyl sulfonic acid, methacrylamide isopropyl sulfonic acid, methacrylamide n-butyl sulfonic acid, methacrylamide s-butyl sulfonic acid , Metaacramide t-butyl sulfonic acid, methacrylamide pentane sulfonic acid, methacrylamide hexane sulfonic acid, methacrylamide heptane sulfonic acid, methacrylamide octane sulfonic acid, divinylbenzene, 1,3-butylene glycol diacrylate, 1,5- Pentanediol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, diethylene glycol Coal diacrylate, diethylene glycol dimethacrylate, tri-ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, polyethylene glycol # 400 dimethacrylate, polyethylene glycol # 600 dimethacrylate, polypropylene dimethacrylate N, N-methylenebismethacrylamide, pentaerythritol tri-methacrylate, tri-methylolpropane tri-methacrylate, tetramethylolpropane tri-methacrylate, 1,4-butanediol dimethacrylate, 2,2-bis (4-methacryloxypolyethoxyphenyl) propane and the like are exemplified.

  As a synthesis method of the styrene-based (co) polymer, it can be produced by a known polymerization method such as a bulk polymerization method, a solution polymerization method, a suspension polymerization method, and an emulsion polymerization method.

  Examples of the polymerization initiator at that time include t-butylperoxymethacrylate, t-butylperoxycrotonate, di (t-butylperoxy) fumarate, t-butylperoxyallylcarbonate, pertrimellitic acid tri-t-butylester, Pertrimellitic acid tri-t-amino ester, pertrimellitic acid tri-t-hexyl ester, pertrimellitic acid tri-t-1,1,3,3-tetramethylbutyl ester, pertrimellitic acid tri- t-cumyl ester, pertrimellitic acid tri-t- (p-isopropyl) cumyl ester, pertrimesic acid tri-t-butyl ester, pertrimesic acid tri-t-amino ester, pertrimesic acid tri-t-hexyl Ester, tri-t-1,1,3,3-tetramethylbutyl pertrimesate Ter, pertrimesic acid tri-t-cumyl ester, pertrimesic acid tri-t- (p-isopropyl) cumyl ester, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane, 2, 2-bis (4,4-di-t-hexylperoxycyclohexyl) propane, 2,2-bis (4,4-di-t-amylperoxycyclohexyl) propane, 2,2-bis (4,4 -Di-t-octylperoxycyclohexyl) propane 2,2-bis (4,4-di-α-cumylperoxycyclohexyl) propane, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) ) Butane, 2,2-bis (4,4-di-t-octylperoxycyclohexyl) butane, and the like can be used.

  In the chromatogram measured by GPC, the styrene-based (co) polymer has an Mw of 100,000 or more, an Mw / Mn of 15 to 100, a molecular weight of 3,000 to 12,000, and a molecular weight of 100. It is preferable that at least one local maximum value or shoulder is provided in each of the 3,000 or more regions.

  Moreover, what has Tg of the said styrene-type (co) polymer in the range of 45-75 degreeC is preferable. By satisfying the above conditions of Mw, Mw / Mn, the maximum value, and Tg, very good performance is exhibited in the balance of fixability, offset property, and storage stability.

  Specifically, Mw is 100,000 or more, Mw / Mn is 15 or more, and has a first maximum value or shoulder in a region having a molecular weight of 3,000 to 12,000, and a molecular weight of 100,000 or more. The use of the one having the second maximum value or shoulder in the region is preferable because the cohesive force of the styrene-based (co) polymer is improved and the offset resistance is good, and at the same time, Mw / Mn is less than 100, or the one having the first maximum value or shoulder in a region with a molecular weight of less than 12,000 reduces the viscosity of the styrene-based (co) polymer, thereby fixing It is preferable because the toner has good blocking properties when Tg is higher than 45 ° C, and is preferably lower than 75 ° C. Preferably possible to raise the lowest fixing temperature of the toner.

  Examples of the polyester resin used as the binder resin of the present invention include a polycondensate of a polyol and a polycarboxylic acid. The polyol is a diol, a tri- or higher valent polyol and its lower (1 to 8 carbon) alkanoic acid ester, and the polycarboxylic acid is a dicarboxylic acid, a tri- or higher valent polycarboxylic acid and its acid anhydride or lower ( C1-C4) alcohol ester is mentioned. As the diol, a diol having a hydroxyl value of 180 to 1900 mg KOH / g, specifically, alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1, 6-hexanediol), alkylene ether glycol (diethylene glycol, tri-ethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.), alicyclic diol (1,4-cyclohexanedimethanol, hydrogen) Added bisphenol A, etc.), bisphenols (bisphenol A, bisphenol F, bisphenol S, etc.), C2-C4 alkylene oxides of the above alicyclic diols (ethylene oxide, Adducts of propylene oxide, butylene oxide, etc.) and adducts of alkylene oxides having 2 to 4 carbon atoms (ethylene oxide, propylene oxide, butylene oxide, etc.) of the bisphenols. 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. Examples of the trivalent or higher polyol include polyols having a hydroxyl value of 150 to 1900 mg KOH / g, specifically, 3 to 8 or higher aliphatic polyhydric alcohols (glycerin, trimethylolethane, trimethylolpropane, pentane). Erythritol, sorbitol, etc.), adducts of C2-C4 alkylene oxides (ethylene oxide, propylene oxide, butylene oxide, etc.) of the above aliphatic polyhydric alcohols, trisphenols (trisphenol PA, etc.); novolac resins (phenol) Novolak, cresol novolak, etc.), C2-C4 alkylene oxide adducts of the above trisphenols, C2-C4 alkylene oxide adducts of the above-mentioned novolac resins, and the like. Among these, preferred are trivalent to octavalent or higher aliphatic polyhydric alcohols and alkylene oxide adducts of novolac resins, and particularly preferred are alkylene oxide adducts of novolac resins.

  Examples of the dicarboxylic acid include dicarboxylic acids having an acid value of 180 to 1250 mg KOH / g, specifically, alkylene dicarboxylic acids (succinic acid, adipic acid, sebacic acid, dodecenyl succinic acid, etc.), alkenylene dicarboxylic acids (maleic acid, fumaric acid, etc.) And aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, etc.). Among these, preferable are alkenylene dicarboxylic acids having 4 to 20 carbon atoms, aromatic dicarboxylic acids having 8 to 20 carbon atoms, and alkylene dicarboxylic acids having 6 to 21 carbon atoms. Moreover, even if these use together 2 or more types, there is no problem. Examples of trivalent to hexavalent or higher polycarboxylic acids include polycarboxylic acids having an acid value of 150 to 1250 mgKOH / g, specifically, aromatic polycarboxylic acids having 9 to 20 carbon atoms (trimellitic acid, pyromellitic acid). Acid), vinyl polymers of unsaturated carboxylic acid (styrene / maleic acid copolymer, styrene / acrylic acid copolymer, α-olefin / maleic acid copolymer, styrene / fumaric acid copolymer, etc.), etc. Can be mentioned. Among these, preferred are aromatic polycarboxylic acids having 9 to 20 carbon atoms, and particularly preferred are trimellitic acid and pyromellitic acid. In addition, as the dicarboxylic acid or the trivalent or higher polycarboxylic acid, acid anhydrides or lower alkyl esters (methyl ester, ethyl ester, isopropyl ester, etc.) described above may be used.

  The ratio of the polyol and the polycarboxylic acid is usually 2/1 to 1/2, preferably 1.5 / 1 to 1/1 / as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. 1.5, more preferably 1.4 / 1 to 1 / 1.4. The types of polyol and polycarboxylic acid to be used are selected in consideration of molecular weight adjustment so that the glass transition point of the polyester toner binder finally prepared is 45 to 70 ° C.

  The number average molecular weight (MnA) of the high molecular weight polyester useful for the toner binder for full color is usually 1800 to 1 million, preferably 2,000 to 100,000, more preferably 5,000 to 50,000, and the weight average molecular weight. (MwA) is 20,000 to 5,000,000, preferably 20,000 to 2,000,000, and more preferably 22,000 to 120,000.

  The polyester usually has a tetrahydrofuran (THF) insoluble content of 5 to 90% by mass, preferably 15 to 80% by mass, more preferably 20 to 70% by mass, and particularly preferably 25 to 60% by mass. When the THF-insoluble content is 5 to 90% by mass, the hot offset resistance is further improved. Moreover, it is preferable that it has a maximum value in the molecular weight 2000-2 million in GPC of THF soluble part, and it is still more preferable if it has a maximum value in 4,000-20000. By having the maximum molecular weight in the range of 2,000 to 2,000,000, the heat resistant storage stability and the powder fluidity are improved. The softening point measured with a polyester flow tester is usually 120 to 230 ° C, preferably 131 to 200 ° C, more preferably 135 to 190 ° C, and particularly preferably 160 to 180 ° C. By having a softening point of 120 to 230 ° C., it becomes easy to achieve both sufficient hot offset resistance and low-temperature fixability and pigment dispersibility. The acid value of the polyester is usually 0 to 40, preferably 8 to 30. By setting the acid value to 0 to 40, it becomes easy to achieve both sufficient charge amount, fixability, and environmental dependency of the charge amount.

  The production method of the polyester used in the present invention is exemplified. The polyester is obtained by heating and dehydrating condensation of a polyol and a polycarboxylic acid in the presence of a known esterification catalyst such as tetrabutoxy titanate or dibutyltin oxide at 150 to 280 ° C. It is also effective to reduce the pressure in order to improve the reaction rate at the end of the reaction.

  Specific examples of the polyester resin used in the present invention include the following. Bisphenol A propylene oxide 2 mol adduct / terephthalic acid polycondensate, bisphenol A propylene oxide 2 mol adduct / terephthalic acid / maleic anhydride polycondensate, bisphenol A ethylene oxide 2 mol adduct / terephthalic acid polycondensate, bisphenol A ethylene oxide 2 mol adduct / terephthalic acid / trimellitic anhydride polycondensate, bisphenol A ethylene oxide 2 mol adduct / bisphenol A ethylene oxide 4 mol adduct / terephthalic acid polycondensate, bisphenol A ethylene oxide 2 mol addition Terephthalic acid / trimellitic anhydride polycondensate, bisphenol A propylene oxide 2-mole adduct / bisphenol A ethylene oxide 4-mole adduct / terephthalic acid polycondensate, bis Enol A ethylene oxide 2 mol adduct / terephthalic acid / trimellitic anhydride polycondensate, bisphenol A propylene oxide 2 mol adduct / terephthalic acid / adipic acid polycondensate, bisphenol A propylene oxide 2 mol adduct / bisphenol A ethylene Oxide 2 mol adduct / terephthalic acid / fumaric acid / trimellitic anhydride polycondensate, bisphenol A propylene oxide 2 mol adduct / bisphenol A ethylene oxide 2 mol adduct / phenol novolac ethylene oxide adduct / terephthalic acid / anhydrous Trimellitic acid polycondensate, bisphenol A propylene oxide 2-mole adduct / bisphenol A ethylene oxide 2-mole adduct / terephthalic acid / trimellitic anhydride polycondensate, bisphenol 2-mol adduct of diol A propylene oxide / propylene oxide adduct of phenol novolac / terephthalic acid / dodecenyl succinic anhydride / trimellitic anhydride polycondensate, bisphenol A propylene oxide 2 mol adduct / dodecenyl succinic anhydride / terephthalic acid / tri anhydride Mellitic acid polycondensate, bisphenol A propylene oxide 2 mol adduct / bisphenol A propylene oxide 3 mol adduct / phenol novolak propylene oxide adduct / terephthalic acid / trimellitic anhydride polycondensate, bisphenol A propylene oxide 2 mol addition / Bisphenol A propylene oxide 3 mol adduct / terephthalic acid / trimellitic anhydride polycondensate, bisphenol A propylene oxide 2 mol adduct / Bisphenol A ethylene oxide 2 mol adduct / terephthalic acid / trimellitic anhydride polycondensate, bisphenol A propylene oxide 2 mol adduct / bisphenol A ethylene oxide 2 mol adduct / terephthalic acid / trimellitic anhydride polycondensate, bisphenol A propylene oxide 2 mol adduct / bisphenol A propylene oxide 3 mol adduct / phenol novolak propylene oxide adduct / terephthalic acid / trimellitic anhydride polycondensate, bisphenol A propylene oxide 2 mol adduct / fumaric acid / tri anhydride Merit acid polycondensate, etc.

  Further, the binder resin composition of the present invention may contain a graft polymer having a structure in which a vinyl resin having an SP value of 10.6 to 12.6 is grafted to a polyolefin resin having a softening point of 80 to 170 ° C. good. Examples of olefins constituting the polyolefin resin include ethylene, propylene, 1-butene, isobutylene, 1-hexene, 1-dodecene and 1-octadecene. Examples of the polyolefin resin include olefin polymers, oxides of olefin polymers, modified products of olefin polymers, and copolymers with other monomers copolymerizable with olefins. . Specific examples include polyethylene, polypropylene, ethylene / propylene copolymer, ethylene / 1-butene copolymer, and propylene / 1-hexene copolymer.

  The softening point of polyolefin resin is 80-170 degreeC normally, Preferably it is 90-160 degreeC, More preferably, it is 100-155 degreeC. When the softening point exceeds 80 ° C., the fluidity of the toner becomes good, and when it is less than 170 ° C., a good release effect is exhibited. The melt viscosity is usually 2 to 10000 (mPa · s) at 160 ° C., preferably 3 to 7000 (mPa · s), and more preferably 5 to 4500 (mPa · s). From the viewpoint of filming on a photosensitive drum and / or developing sleeve, developing rubber roller, magnetic carrier, and releasability to a fixing device (roller, belt, etc.), the number average molecular weight is usually 500 to 20,000, The weight average molecular weight is 800 to 100,000, preferably the number average molecular weight is 1,000 to 15,000, the weight average molecular weight is 1,500 to 60,000, more preferably the number average molecular weight is 1,500 to 1,500. The weight average molecular weight is 10,000 to 30,000.

The SP value (solubility parameter) of the vinyl resin is usually 10.6 to 12.6 (cal / cm ³ ) 1/2, preferably 10.6 to 12.0 (cal / cm ³ ) 1/2, preferably ^{10.7~11.8 (cal / cm 3) 1/2} , particularly preferably ^{10.8~11.5 (cal / cm 3) 1/2} . Even if the SP value exceeds 12.6, even if it is less than 10.6, the SP value difference with the binder resin becomes too large, resulting in poor dispersion of the release agent. The SP value can be calculated by a known Fedors method.

  Examples of MA include unsaturated nitrile monomers and α, β-unsaturated carboxylic acids. Examples of the unsaturated nitrile monomer include (meth) acrylonitrile and cyanostyrene. Of these, (meth) acrylonitrile is preferred.

  Examples of α, β-unsaturated carboxylic acids include unsaturated carboxylic acids and anhydrides thereof ((meth) acrylic acid, maleic acid, fumaric acid, itaconic acid and anhydrides thereof), unsaturated dicarboxylic acid monoesters [malein Monomethyl acid, monobutyl maleate, monomethyl itaconate, etc.]. Among these, (meth) acrylic acid and unsaturated dicarboxylic acid monoesters are preferable, and (meth) acrylic acid and maleic acid monoester [monomethyl maleate, monobutyl maleate] are particularly preferable.

  BA includes styrene monomers (styrene, α-methylstyrene, p-methylstyrene, m-methylstyrene, p-methoxystyrene, p-hydroxystyrene, p-acetoxystyrene, vinyltoluene, ethylstyrene, phenylstyrene, benzyl. Styrene), unsaturated carboxylic acid alkyl (C1-C18) ester (methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, etc.), vinyl ester Monomers (such as vinyl acetate), vinyl ether monomers (such as vinyl methyl ether), halogen element-containing vinyl monomers (such as vinyl chloride), diene monomers (such as butadiene and isobutylene), and combinations thereof. Among these, a styrene monomer, an unsaturated carboxylic acid alkyl ester, and a combination thereof are particularly preferable, and styrene and a combination of styrene and a (meth) acrylic acid alkyl ester are particularly preferable.

  In the toner binder composition of the present invention, other resins can be contained together with the polyester-based toner binder. Other resins include styrene resins (such as copolymers of styrene and alkyl (meth) acrylates, copolymers of styrene and diene monomers), epoxy resins (such as addition condensates of bisphenol A and epichlorohydrin), urethane, and the like. Examples thereof include resins (polyaddition product of diol and diisocyanate, etc.).

  Among the resins described above, a polyester resin or a polyether polyol resin excellent in thermal properties such as resin elasticity and spectral transmission characteristics is preferably used as the binder resin used in the color toner.

  The toner binder resin has a low molecular weight component having a weight average molecular weight Mw of about 5000 to 30000 and a weight average molecular weight Mw of 30000 to 30000 in order to satisfy performances such as transparency, meltability, and durability of the toner. A resin composition in which a high molecular weight component of about 100,000 is mixed at a ratio of about 1: 9 to 9: 1, or a crystalline resin of about several percent to 20% is added to impart sufficient meltability. It is particularly desirable to use a resin composition or the like.

  As the colorant, either a pigment or a dye may be used, or a combination of a pigment and a dye may be used. Among these, by using a pigment, a toner having excellent weather resistance can be obtained, and an image having high quality and stable quality can be formed. Therefore, it is preferable to use a pigment as a colorant.

  The color of the colorant is appropriately selected so that a toner having a desired color is realized. For the reproduction of each color in a full-color electrophotographic image, three color toners of yellow (Yellow; abbreviation: Y), magenta (abbreviation: M) and cyan (Cyan; abbreviation: C) are used. Each color is expressed by superimposing toner. However, since it is difficult to reproduce black in the mixed color of the three colors, black (Black; abbreviation: K) toner is used for black expression. A chromatic colorant corresponding to each color is used for the color toner, and a black colorant is used for the black toner.

  As the chromatic colorant, an organic pigment is preferably used, and specific examples thereof include the following pigments classified by color index (abbreviation: CI) numbers. Examples of coloring yellow pigments used for yellow toner include C.I. I. Bisazo pigments such as CI Pigment Yellow 17; I. Monoazo pigments such as C.I. Pigment Yellow 74 and 97; I. Condensed azo pigments such as CI Pigment Yellow 93 and 128, and C.I. I. Benzimidazolone pigments such as CI Pigment Yellow 180 and 194. Examples of the magenta pigment for coloring used in the magenta toner include C.I. I. Quinacridone pigments such as C.I. Pigment Red 122 and 202; I. Lake azo pigments such as C.I. Pigment Red 57, C.I. I. Perylene pigments such as CI Pigment Red 149, 190 and 224, and C.I. I. And naphthol-benzimidazolone pigments such as CI Pigment Red 184 and 185. Examples of the cyan pigment for coloring used in the cyan toner include known phthalocyanine pigments. I. A copper phthalocyanine pigment such as CI Pigment Blue 15: 3 or 15: 4 is preferably used.

  As the black colorant, known ones can be used, and various carbon blacks classified by the production method are suitably used. Specific examples include furnace black, channel black, acetylene black, thermal black, and lamp black.

The content of the colorant in the toner composition is preferably in the range of 5 to 20% by weight. In particular, when an image is formed with a small amount of toner with the amount of toner adhering to the transfer medium being 0.5 mg / cm ² or less as described above, the content of the colorant in the toner composition should be within the above range. Is preferred.

  By setting the content of the colorant in the above range, a toner having a high coloring power, a sufficient color can be obtained with a small amount of toner, and a high density and clear image can be formed. As a result, since the content of the binder resin in the toner composition can be made sufficient, a toner having excellent fixability to a transfer medium is realized. In the case of a color toner, by setting the content of the colorant in the above range, color development is excellent, the saturation and brightness of the formed image is high, and the secondary color reproduction range by superimposing the toners of the respective colors. Wide color toner is realized.

  When the content of the colorant in the toner composition is less than 5% by weight, a sufficient image density may not be obtained. When the content exceeds 20% by weight, the saturation and lightness of the formed image are reduced, secondary This is not desirable because it causes a reduction in the color reproduction range and a deterioration in the fixing property on the transfer medium due to a decrease in the melting resin component. Therefore, the preferable range of the content of the colorant in the toner composition is 5% by weight or more and 20% by weight or less.

The content of the colorant in the toner composition is desirably increased as the amount of toner used for one image formation is smaller. For example, when the toner adhesion amount on the transfer medium is 0.5 mg / cm ² , it is preferable that at least 5 wt% to 12 wt% of the colorant is contained, and 0.4 mg / cm ² . Preferably contains at least 8% to 15% by weight of colorant, and in the case of 0.3 mg / cm ² , it may contain at least 10% to 20% by weight of colorant. desirable.

As described above, the toner adhesion amount in the single-color solid portion of the unfixed toner image formed on the transfer medium is 0.5 mg / cm in order to reduce the size of the image forming apparatus and improve the image quality of the formed image. ² or less is preferable, and 0.4 mg / cm ² or less is more preferable. However, when the toner adhesion amount is less than 0.3 mg / cm ² , the monochromatic solid portion image may be changed depending on the particle size and particle size distribution of the toner, the content of the colorant, and the dispersion state of the pigment when using the pigment. When the toner is formed, a sufficient image density may not be obtained. Therefore, the toner adhesion amount is preferably 0.3 mg / cm ² or more.

  The amount of toner adhering to the transfer medium can be adjusted by controlling the amount of developer transport / the amount of toner in the developer.

  When the toner of the present invention is used in an image forming apparatus equipped with an oilless fixing device, it preferably contains a release agent in addition to the binder resin and the colorant. Here, the oilless fixing device is a fixing device that fixes a toner image transferred onto a transfer medium without applying a release agent such as oil to a fixing member. Examples of the oilless fixing device include a device that fixes a toner image by applying heat and pressure by a fixing member.

  By including a release agent in the toner, a releasing effect from the fixing member can be imparted, and an offset phenomenon when used in an image forming apparatus equipped with an oilless fixing device and a transfer medium to the fixing member. Winding can be suppressed. Also, by including a release agent in the color toner, even when used in an image forming apparatus equipped with an oil-less fixing device, it is excellent in color development and gloss, and forms a homogeneous and clear color image. Toner that can be used is realized.

  When the release agent is contained in the toner, the content of the release agent in the toner composition is preferably 3% by weight to 10% by weight. When the content of the release agent is less than 3% by weight, the effect of releasing from the fixing member cannot be sufficiently obtained, and when used in an image forming apparatus having an oilless fixing device, an offset phenomenon and a transfer medium It is easy to cause wrapping around the fixing member. Further, when the content of the release agent exceeds 10% by weight, a sufficient dispersion state cannot be obtained in the toner composition, and a free substance existing as a single release agent is generated at the time of toner production. Since many release agents are exposed on the surface of the toner particles, fusion to the developer regulating blade and filming on a recording medium such as a photoreceptor are likely to occur, and at a high temperature. Inconveniences such as a decrease in storage stability occur. Therefore, the preferable range of the content of the release agent in the toner composition is 3 wt% to 10 wt%.

Suitable mold release agents include synthetic waxes such as polyethylene wax and polypropylene wax, natural waxes such as carnauba wax and rice wax, and waxes such as silicone wax, higher fatty acid wax, polyolefin wax, and low molecular weight polymer wax. Used. One of these waxes may be used alone, or two or more thereof may be mixed and used.
Among the waxes, it is preferable to use a color toner having a melting point of 70 ° C. to 100 ° C. in order to impart sufficient melting characteristics.

  The toner of the present invention has toner particles with a particle size of 1.0 μm or less having a circularity of 0.96 or more, and after standing in a standard environment (25 ° C., indoor humidity 50%) for 48 hours, the water content is 1. It is 0% or less. If the circularity of toner particles of 1.0 μm or less is less than 0.96, the untransfer rate is increased in the transfer step, leading to a reduction in consumption and the life of the cleaning member. Accordingly, the circularity of the entire toner particles is preferably 0.96 or more.

The circularity of the toner particles is expressed by the following equation, and the measurement can be performed by FPIA-2000 manufactured by Sysmex Corporation.
Circularity = (circumference of a circle having the same area as the particle projection area) / (perimeter of the particle projection image)

  The moisture absorption amount of the toner is 1.0% or less, more preferably 0.5% or less after the toner is left in a standard environment (25 ° C., indoor humidity 50%) for 48 hours. When the moisture absorption amount is large, not only the storage stability is deteriorated, but also the fluctuation amount of the charge amount with respect to the environmental conditions is increased, which causes an image quality deterioration, which is not preferable. In order to improve the storage stability and the image quality, the water content needs to be 1.0% by weight or less. Various measurement methods such as a conventionally known betting method and Karl Fischer method can be used for moisture measurement.

  The toner of the present embodiment may contain other additives such as a charge control agent or an external additive in addition to the binder resin, the colorant, and the release agent. As the charge control agent, known ones can be used. As the charge control agent used for the color toner, a quaternary ammonium salt is used for positive charge, and a metal salt of alkyl salicylic acid is used for negative charge. Thus, it is preferable to use a colorless one. The charge control agent is not limited to these inorganic charge control agents, and an organic charge control agent such as a resin having an ionic group such as a sulfonic acid group may be used.

  Next, the external additive used for the toner of the present invention will be described. To the toner of the present invention, so-called external additives can be added and used for the purpose of improving fluidity, chargeability and cleaning property. These external additives are not particularly limited, but various inorganic fine particles, organic fine particles and lubricants can be used.

  A conventionally well-known thing can be used as an inorganic fine particle. Specifically, silica, titanium, alumina fine particles and the like can be preferably used. These inorganic fine particles are preferably hydrophobic. Specifically, as silica fine particles, for example, commercially available products R-805, R-976, R-974, R-972, R-812, R-809 manufactured by Nippon Aerosil Co., Ltd., HVK-2150, H manufactured by Hoechst -200, commercially available products TS-720, TS-530, TS-610, H-5, MS-5 and the like manufactured by Cabot Corporation.

  Examples of the titanium fine particles include commercially available products T-805 and T-604 manufactured by Nippon Aerosil Co., Ltd., commercially available products MT-100S, MT-100B, MT-500BS, MT-600, MT-600SS, and JA- 1. Commercial products TA-300SI, TA-500, TAF-130, TAF-510, TAF-510T manufactured by Fuji Titanium Co., Ltd. Commercial products IT-S, IT-OA, IT-OB, IT- manufactured by Idemitsu Kosan Co., Ltd. OC etc. are mentioned.

  Examples of the alumina fine particles include commercial products RFY-C and C-604 manufactured by Nippon Aerosil Co., Ltd. and commercial products TTO-55 manufactured by Ishihara Sangyo Co., Ltd.

  As the organic fine particles, spherical organic fine particles having a number average primary particle diameter of about 10 to 2000 nm can be used. As this, a homopolymer such as styrene or methyl methacrylate or a copolymer thereof can be used.

  Examples of lubricants include, for example, zinc stearate, aluminum, copper, magnesium, calcium, etc., zinc oleate, manganese, iron, copper, magnesium, etc., zinc palmitate, copper, magnesium, calcium, etc. And salts of higher fatty acids such as zinc of linoleic acid, salts of calcium, etc., zinc of ricinoleic acid, salts of calcium, etc.

  The amount of these external additives added is preferably 0.1 to 5% by mass with respect to the toner. Examples of the method for adding the external additive include various known mixing apparatuses such as a Turbuler mixer, a Henschel mixer, a Nauter mixer, and a V-type mixer.

  The toner of the present invention contains the materials described above. In this specification, the toner composition is a material constituting toner particles, and is added after the toner particles are produced. Things such as external additives are not included. That is, the toner composition includes at least a binder resin and a colorant, and also includes an additive such as a release agent that is mixed together with the binder resin and the colorant to become part of the toner particles.

The toner of the present invention is suitably used for developing an electric latent image such as an electrostatic latent image in image formation by electrophotography or the like. When developing the latent image, the toner of the exemplary embodiment may be used alone as a one-component developer, or may be mixed with a carrier and used as a two-component developer. The toner of the present invention is not limited to the development of an electric latent image, and may be used for developing a latent image in other different image forming methods, for example, developing a magnetic latent image in a magnetic printing method. When the toner of the present invention is used in the magnetic printing method, the toner of the present embodiment is made magnetic by adding magnetic powder or the like to obtain a magnetic toner.
The toner of the present invention is produced by wet pulverization in water after mixing raw materials and subjecting them to melt-kneading and dispersion treatment.

As a melt-kneading method, a conventionally known biaxial kneader (Nippon Steel Works, Toshiba Machine, etc.), an open roll (Mitsui Mine), etc. can be used.
By processing the melt-kneaded product obtained as described above with a rotor / screen type wet dispersion pulverizer, a toner having a sharp particle size distribution and a high circularity can be obtained.

  Specific examples of the apparatus include “CLEARMIX” (manufactured by M Technique Co., Ltd.). This “Clearmix” has a rotor (stirring blade) that rotates at a high speed and a fixed screen (fixed ring) that surrounds the rotor, and a shearing force, collision force, pressure fluctuation, cavitation and It has a structure that imparts the action of a potential core, and these actions function synergistically to effectively emulsify and disperse the liquid to be treated. That is, this “Clear mix” is originally used for the production of emulsion (dispersion of liquid fine particles), but the present inventors use it as an apparatus for dispersing solid colorant fine particles in an aqueous medium. Thus, it has been found that a dispersion of colorant fine particles having a preferable average particle size and a sharp particle size distribution can be obtained.

  FIG. 1A is a schematic diagram showing a rotor that rotates at a high speed and a fixed screen that surrounds the rotor. In FIG. 1, 101 is a screen, M is an agitation chamber partitioned by the screen 101, 102. Indicates a rotor rotating at high speed in the stirring chamber M. The rotor 102 is a stirring blade that rotates at a high speed, and its rotation speed is usually 4,500 to 22,000 rpm, preferably 10,000 to 21,500 rpm. The tip peripheral speed of the rotor 2 is normally 10 to 40 m / sec, preferably 15 to 30 m / sec. The screen 101 arranged so as to surround the rotor 102 is formed of a fixed ring composed of a large number of slits (not shown). The width of the slit is 0.5 to 5 mm, preferably 0.8 to 2 mm. Moreover, the number of slits is 10-50, Preferably it is 15-30. The gap (clearance) between the rotor 102 and the screen 101 is usually 0.1 to 1.5 mm, preferably 0.2 to 1.0 mm.

  The average particle size and particle size distribution of the colorant fine particles are adjusted by controlling the number of revolutions of the rotor 102, and can be adjusted by selecting the shapes of the screen 101 and the rotor 102. Specifically, the screen (S1.0-24, S1.5-24, S1.5-18, S2.0-18, S3.0-9) and the rotor (R1), which are standard equipment in “CLEARMIX”, are provided. Although a preferable dispersion state is obtained by combination with ~ R4), it may be produced in-house to obtain a more preferable dispersion state.

  FIG.1 (b) is a schematic diagram which shows the continuous processing apparatus (Clear mix) provided with the rotor and the screen. The predispersed dispersion liquid (preliminary dispersion liquid) is supplied to the stirring chamber between the screen 101 and the rotor from the preliminary dispersion liquid inlet 104 shown in FIG. The screen 101 and the rotor are surrounded by a pressurized vacuum attachment 103, and a temperature sensor 106, a cooling jacket 107, and a cooling coil 108 are disposed. The toner mass in the preliminary dispersion is crushed (finely dispersed) by applying a shearing force generated by the rotor rotating at high speed and the screen 101. That is, the colorant-aggregated particles in the preliminary dispersion supplied to the band-shaped stirring chamber located between the screen 101 and the rotor are subjected to shear force (mechanical energy) generated by high-speed rotation of the screen 101 and the rotor. In addition to the shearing force, the toner is pulverized (finely dispersed) into toner fine particles by the action of impact force, pressure fluctuation, cavitation, and potentio core. The toner fine particle dispersion is ejected from the slit of the screen 101 into the pressurized vacuum attachment 103 to obtain a dispersion of toner particles having a preferable average particle size and sharp particle size distribution. The dispersion liquid containing the toner particles is sent to the next process from the dispersion liquid outlet 5.

  The toner lump is pulverized in the stirring device by the action of the rotor and the screen to become toner particles having a preferable average particle size and sharp particle size distribution, and the formation mechanism is based on the following plural actions. .

(1) Near the surface of the rotor (stirring blade) that rotates at high speed, the speed gradient is large, so a high-speed shear rate region is formed near the surface, and the toner mass is crushed by the shearing force generated in this region.
(2) Behind the rotor (stirring blade), when the rotational speed is high, a vacuum part (cavitation) is generated, and the bubbles generated by the rotation are extinguished when the flow velocity of the dispersion is lowered. An impact pressure is generated along with the compression, and the toner mass is crushed by the impact pressure.
(3) The rotor (stirring blade) imparts pressure energy to the preliminary dispersion by its high-speed rotation, but when the pressure energy is suddenly released, the kinetic energy of the preliminary dispersion increases, and the preliminary dispersion flowing by the rotor is When repeatedly passing between the open part (slit part) and the sealed part (non-slit part) of the screen, a pressure wave is generated by changing the pressure energy to pulverize the toner mass.
(4) When the pre-dispersion liquid having a large kinetic energy collides with the screen or other wall, the toner mass subjected to the collision force is pulverized to become toner particles having a sharp particle size distribution.
(5) When the dispersion having velocity energy passes through the slit portion of the screen, it becomes a jet (jet flow). In the potential core (velocity region not affected by the viscous flow) in the jet, the surrounding fluid is sucked at a high speed. The toner mass that has received this energy is pulverized into toner particles having a sharp particle size distribution.

  The dispersion time for obtaining the toner particle dispersion is not particularly limited, but is 5 to 30 minutes, preferably 7 to 25 minutes. Moreover, when circulating, 5 or more passes are preferable, More preferably, it is 5 to 20 passes. If the dispersion time is too long, the dispersion becomes excessive and the abundance of fine particles increases, which is not preferable.

  FIG.1 (c) is a schematic diagram which shows the dispersion | distribution container which comprises such a stirring apparatus (Clear mix), and a dispersion process is performed by such an apparatus. In FIG. 1C, 111 is a dispersion vessel, 112 is a stirring device, and 113 is a stirring shaft for driving the stirring device 112. The stirring device 112 has the same configuration (screen and rotor) as that shown in FIG. The preliminary dispersion (toner particle dispersion) enters the stirring chamber from the upper part of the stirring device 112, and is stirred by the strong shearing force, impact force and turbulent flow generated between the rotor rotating at high speed and the screen. Toner particles having a particle diameter of 4 to 9 μm are formed and ejected into the dispersion container 111 from the slits of the screen. In the toner particle dispersion step, the dispersion container 111 may have a jacket structure, and warm water or steam, cold water or the like may flow through the jacket to control the temperature in the dispersion container 111.

  In the case of performing the dispersion treatment using the dispersion container shown in FIG. 1 (c), the colorant ejection direction from the stirring chamber of the stirring device 112 (the ejection direction of the colorant fine particles into the aqueous medium) It is preferred that it is downward or horizontal. By ejecting the toner particles downward or horizontally, the aqueous medium in the dispersion container 111 flows as indicated by the arrow F. As a result, the colorant is ejected downward, the flow rises along the wall, and again It is a system that circulates in the Claire mix. For this reason, a dispersion | distribution process can be repeated reliably and dispersion | distribution energy can be provided uniformly.

  As described above, the toner particles preferably used in the present invention are pulverized by the action of the shearing force generated by the screen and the rotor, and have a suitable average particle diameter (volume average particle diameter: 4 to 9 μm) and sharpness. A dispersion of toner particles having a uniform particle size distribution (standard deviation (σ) of 30 or less) is obtained.

  After the granulation step, the washing and concentration steps are repeated, and the toner of the present invention can be obtained by drying by a conventionally known method. Examples of the washing concentration include a centrifugal separation method, a vacuum filtration method using Nutsche and the like, a filtration method using a filter press and the like, but are not particularly limited thereto. In addition, examples of dryers used in the subsequent drying process include spray dryers, vacuum freeze dryers, and vacuum dryers, stationary shelf dryers, mobile shelf dryers, fluidized bed dryers, and rotary dryers. It is preferable to use a dryer, a stirring dryer, or the like.

  Although it does not intend to specifically limit as a dispersing agent used in the case of granulation, the following are illustrated. That is, for example, sulfonate (sodium dodecylbenzenesulfonate, sodium arylalkylpolyethersulfonate, sodium 3,3-disulfonediphenylurea-4,4-diazo-bis-amino-8-naphthol-6-sulfonate, Ortho-carboxybenzene-azo-dimethylaniline, 2,2,5,5-tetramethyl-triphenylmethane-4,4-diazo-bis-β-naphthol-6-sulfonic acid sodium salt), sulfate ester salt (dodecyl) Sodium sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate), fatty acid salts (sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, potassium stearate, Ionic surfactants such as calcium oxide) or, for example, polyethylene oxide, polypropylene oxide, combinations of polypropylene oxide and polyethylene oxide, esters of polyethylene glycol and higher fatty acids, alkylphenol polyethylene oxide, higher fatty acids and polyethylene glycol Nonionic surfactants such as esters, esters of higher fatty acids and polypropylene oxide, and sorbitan esters can be used.

  When a pigment is used as the colorant, the pigment is mixed with the binder resin after being subjected to a preliminary dispersion process in which it is dispersed in a binder resin or a colorless resin different from the binder resin, for example, by masterbatch or flushing. The melt-kneading dispersion treatment may be performed.

  In addition, the mixture containing at least the binder resin and the colorant is dispersed in advance by dry-mixing additives such as a charge control agent, a releasing agent such as waxes, and a dispersing agent with a mixer, The melt-kneading dispersion process may be performed. Henschel mixers (made by Mitsui Mining Co., Ltd.), super mixers (made by Kawata Co., Ltd.), mechano mills (made by Okada Seiko Co., Ltd.), Ongmill (made by Hosokawa Micron Co., Ltd.), high A hybridization system (manufactured by Nara Machinery Co., Ltd.), a Cosmo system (manufactured by Kawasaki Heavy Industries, Ltd.) and the like can be suitably used.

Next, the carrier is described.
(1) The carrier for an electrophotographic developer of the present invention is a resin-coated carrier containing iron oxide as a main component and having a volume average particle size of 30 to 90 μm.
This volume average particle size is selected in view of the balance between image quality improvement and carrier rise.
When the particle diameter is smaller than 30 μm, the carrier is likely to rise on the photoreceptor, and the life of the photoreceptor is shortened.
On the other hand, if it is larger than 90 μm, it becomes impossible to meet the demand for high image quality such as fine line reproducibility.
(2) Magnetization in a magnetic field of 1 kOe is 65 to 80 emu / g. Magnetization in a magnetic field of 1 kOe is measured using a vibration type magnetometer VSM-P7 manufactured by Toei Industry Co., Ltd. When the magnetization is less than 65 emu / g, the force with which the carrier particles are held by the magnet roll becomes small, and carrier scattering occurs. When the magnetization exceeds 80 emu / g, the magnetic brush becomes hard and soft development cannot be performed.
(3) The current value of the carrier core material is 50 to 150 μA. The current value of the carrier core material is measured by setting 500 g of the carrier core material in a developing machine facing the aluminum base tube and reading the value of the conduction current when a DC voltage of 200 V is applied. When the current value is less than 50 μA, the developability deteriorates, and when it exceeds 150 μA, problems such as leakage occur.
(4) The resin coating is applied, and the coating amount is 0.1 to 5.0% by weight with respect to the carrier core material. When the coating amount is less than 0.1% by weight, the effect of charge amount control and resistance control due to the effect of the coating resin is reduced. This causes malfunctions.

  The carrier coat resin is selected in consideration of the charge train with the toner to be combined. For example, polypropylene, polystyrene, acrylic resin, polyacrylonitrile resin, silicone resin, modified silicone resin, polytetrafluoroethylene, polyvinylidene fluoride, etc. A fluororesin, a polycarbonate resin, an epoxy resin, etc. are mentioned. These can be used alone or in combination, and can be used after further modification. For reasons such as high image quality and long life, a resin material containing a silicone-based resin or a fluorine-based resin that is excellent against toner contamination is preferable.

  When an insulating resin is used as the coating resin, the resistance becomes high. Therefore, a known conductive agent such as carbon black or titanium oxide is dispersed in the resin as necessary. The coating method includes a method of immersing the carrier core material in the resin solution and drying, a fluidized bed coat in which the carrier core material is flowed and sprayed with the resin solution, and heating while mixing the resin and the carrier core material to form the carrier core material. The dry method etc. which coat | cover can be used.

Next, the developing conditions of the present invention will be described.
In the present invention, normal development without contact or reversal development without contact can be performed. The DC developing electric field at that time is 1 × 10 ³ to 1 × 10 ⁵ V / cm in absolute value, preferably 5 × 10 ³ to 1 × 10 ⁴ V / cm, and development is less than 10 ³ V / cm. Insufficient image density can be obtained, and if it exceeds 10 ⁵ V / cm, the image quality is rough and fogging may occur. The AC bias is 0.5 to 4 kVp-p, and the frequency is 0.1 to 10 kHz, preferably 2 to 8 kHz.

  When the AC bias is less than 0.5 kVp-p, the toner attached to the carrier does not come off, non-contact development is insufficient, and the image density is insufficient. On the other hand, when the AC bias exceeds 4 kVp-p, carriers in the developer fly and cause carrier adhesion on the photosensitive member. If the frequency of the AC bias is less than 0.1 kHz, the toner is not sufficiently detached from the carrier, which may lead to insufficient development and a decrease in image density. On the other hand, if the frequency of the AC bias exceeds 10 kHz, the toner cannot follow the fluctuation of the electric field, resulting in poor development, and the image density may be lowered.

In the following examples, magenta toner is described, but the electrophotographic characteristics are confirmed in the same manner for yellow toner and cyan toner.
In addition, this invention is not limited only to the following Example.
In the following description, the term “parts” means parts by mass.

(Example of toner production)
(Toner Production Example 1)
The binder resin is a polyester resin composition having the characteristics of glass transition temperature Tg: 60 ° C., 1/2 flow softening temperature Tm: 120 ° C., and a low molecular weight component having a weight average molecular weight of about 10,000 and a weight average A polyester resin composition in which a high molecular weight component having a molecular weight of about 100,000 was mixed at a ratio of 4: 6 was used. Examples of the colorant include C.I. in Magenta Toner TM-1 to TM-9. I. Pigment Red 122 is used, and cyan toners TC-1 and TC-2 are C.I. I. Pigment Blue 15: 3 is used, and C.I. I. Pigment Yellow 74 was used. In addition, these pigments are kneaded in advance at a concentration of 40% by weight and preliminarily dispersed only in the low molecular weight component in the polyester resin composition which is a binder resin (hereinafter referred to as a pigment kneaded product for convenience). And used for the production of each toner. A binder resin, a pigment kneaded material, a low melting point polyethylene wax having a melting point of 80 ° C., and a charge control agent were charged into a Henschel mixer at a blending ratio shown in Table 1, and mixed for 10 minutes to obtain a raw material mixture.

The raw material mixture thus obtained was melt kneaded and dispersed with a twin-screw kneader manufactured by Toshiba Machine. Next, the kneaded material obtained by the melt-kneading dispersion treatment is cooled and coarsely crushed, and then wet pulverized using the CREAMIX W motion manufactured by M Technique Co., Ltd., Coulter Multisizer II (Beckman Coulter Co., Ltd.) The toner powder was adjusted so as to have a desired particle size distribution. The resulting granulated product was washed by filtration and dried by a fluid bed dryer to obtain a toner powder. Hydrophobic silica fine powder (BET specific surface area of about 140 m ^{2 /} g) having an average diameter of about 12 nm of primary particles surface-treated with a silane coupling agent having a trimethylsilyl group and 100 parts of the obtained toner powder 1.5 And 1.0 part of hydrophobic silica fine powder (BET specific surface area of about 50 m ^{2 /} g) having an average diameter of about 40 nm of primary particles subjected to the same surface treatment are mixed, and negatively charged toner Was made.

(Example of carrier production)
(Carrier production example 1)
Iron oxide 55 mol%, manganese oxide 40 mol%, magnesium oxide 5 mol% and strontium oxide are added to iron oxide, manganese oxide and magnesium oxide in an amount of 0.8 mol%, wet pulverization, and calcination is performed at a firing temperature of 350 ° C. did. After the fired product was crushed and classified, a carrier core material having an average particle size of 35 μm was obtained. Table 3 shows various physical properties (surface smoothness uniformity, average particle diameter, magnetic characteristics, current value) of the obtained carrier core material.
Carrier 1 is coated with 2.0% by weight of a silicone resin (trade name: SR-2411, manufactured by Toray Dow Corning Silicone Co., Ltd.) on the carrier core material using a fluidized bed coater. After performing, it classified by 250 mesh and manufactured by performing magnetic separation.
(Carrier production examples 2 to 6)
Carriers 2 to 13 were obtained by the same method as in Carrier Production Example 1.

  The toner and the carrier obtained as described above were developed (developer preparation operation) with a Nauter mixer (manufactured by Hosokawa Micron) at the ratio shown in the following table (Table 4) to obtain a developer.

  Each toner / developer produced was evaluated for image quality, fusing resistance and filming resistance as follows. In the following evaluation, a sharp two-component development type full-color multifunction machine was used as the image forming apparatus, and a full-color exclusive paper (product number: PP106A4C) manufactured by Sharp Corporation was used as the recording paper.

<Image quality>
The toner adhesion amount on the recording paper was adjusted to 0.5 mg / cm ² , and an image chart including a 30 mm square monochromatic solid portion was formed on the recording paper, and this was used as an evaluation image. Using a spectrocolorimetric densitometer (manufactured by X-Rite: X-Rite 938), an optical density indicating image density is measured for the image for evaluation, and L ^* a ^* b ^* color system (CIE: 1976). Chromaticness indices a ^* and b ^* were measured, and the saturation represented by the following formula (1) was determined.
(Saturation) = [(a ^* ) ² + (b ^* ) ² ] ^1/2 (1)
In addition, the presence or absence of white background fogging in the non-image portion of the evaluation image was determined visually.
Here, L ^* , a ^* , and b ^* are parameters based on the CIELab color system, L ^* is from black to white (lightness), and a ^* is the degree of red or green (hue) , B ^* are parameters for the degree of yellow or blue (saturation). These are first proposed by Hunter (R.S. Hunter) and are based on a theory known as the Hunter Lab color system.

The image quality was evaluated based on a comprehensive evaluation that combined optical density, saturation, and presence or absence of white background fog. The image quality evaluation criteria are as follows.
(A) Magenta toner ○: Good. Optical density of 1.35 or higher, saturation of 65 or higher, and no white background fog.
Δ: Slightly poor Optical density of 1.35 or more, saturation of 60 or more and less than 65, and no white background fog.
X: Defect. Optical density less than 1.35, or saturation less than 60, or white background fogging.

Table 5 shows the results of image evaluation using the developer (Dev-1) while changing the amount of adhesion on the recording paper.
The developer (Dev-1) to the developer (Dev-7) and the developer (Dev-14) to the developer (Dev-24) were good in any of image density, saturation, and white background fog.

<Non-offset width>
Using a device with a modified two-component development type full-color multi-function machine made by Sharp as a fixing roller, Sharp recommended paper was set on this and a copy test was conducted.
The fixing roll temperature at which the residual ratio of the image density after rubbing the fixed image with a pad becomes 70% or more was defined as the minimum fixing temperature.
The metal cylinder of the fixing roller was made of Fe material with a thickness of 0.34 mm. The surface pressure was set to 1.0 × 10 ⁵ Pa.
Further, the fixing was evaluated in the same manner as the fixing lower limit temperature, and the presence or absence of hot offset to the fixed image was visually evaluated. The fixing roll temperature at which hot offset occurred was defined as the hot offset occurrence temperature.
Then, the difference between the fixing temperature and the hot offset temperature was taken as a non-offset width.
○: 45 ° C or higher △: 20-44 ° C
×: 0 to 19 ° C.

<Filming properties>
Using the above developer on a copying machine imgio NEO450 manufactured by Ricoh Co., Ltd., which has a cleaning blade and a charging roller in contact with the photosensitive member, a black solid is printed at intervals of 1 cm in a direction perpendicular to the rotation direction of the developing sleeve in a normal temperature environment. A4 horizontal chart (image pattern A) that repeats white and white is performed, and the occurrence of filming on the photoconductor after 20,000, 50,000, and 100,000 sheets is detected as an abnormal image (halftone density unevenness) It was evaluated by.
After exposing the developer to a room temperature of 30 ° C. and an indoor humidity of 90% for 2 hours or more, a halftone image of 1 dot × 1 dot is output on A3 paper, and the reflection density of the darkest and the lightest part of the halftone ( ID) was measured with a Macbeth densitometer, and the difference was evaluated in five stages according to the following criteria.
In the state where filming does not occur at all, the reflection density (ID) is an equivalent value, and the larger the value, the worse the halftone unevenness.
Also, filming is more disadvantageous as the number of running sheets increases.
○: 0.1 or less △: 0.11-0.4
X: 0.41 or more

<Career rise / Career scattering>
In the case where a carrier is placed on the photoreceptor, if the carrier is scattered around the developing tank, it was evaluated as x.
As is clear from Table 6 below, all of the developers of the present invention (Examples 1 to 24) are excellent in image quality evaluation, non-offset width, and filming property, and all have no increase in carrier. There is an advantage.

  The present invention provides an electrophotographic developer carrier excellent in image characteristics and the like that can be used as a full-color developer, in which a reduction in particle size is achieved and problems such as carrier scattering are solved, and a method for producing the same. . The present invention also provides a toner that is excellent in filming resistance on a photoconductor and that can form a uniform, clear image with a small toner amount, a high density, a developer using the toner, and A developing method using the toner or the developer is provided. According to the developer of the present invention, it is possible to reduce the size of the developing device and the image forming apparatus.

It is the figure which illustrated the stirring apparatus used in order to obtain the coloring agent in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Screen 102 Rotor M Stirring chamber 103 Pressurized vacuum attachment 104 Preliminary dispersion inlet 105 Dispersion outlet 107 Cooling jacket 108 Cooling coil 111 Dispersion vessel 112 Stirrer 113 Stirring shaft

Claims (11)

  A toner containing at least a binder resin and a colorant, the toner having a volume average particle diameter in the range of 4 μm to 9 μm, and containing 2.0% by volume or less of toner particles having a particle diameter of 15.0 μm or more. A toner containing 30% by number or more of toner particles having a diameter of 3.00 μm or less and 10% by number or less of toner particles having a particle diameter of 1.00 μm or less.   The toner of claim 1 and iron oxide as main components, the volume average particle size is in the range of 30 to 90 μm, the magnetization in the magnetic field of 1 kOe is in the range of 65 to 80 emu / g, and the carrier core material It is composed of a resin-coated carrier having a current value in the range of 50 to 150 μA, resin-coated, and a coating amount in the range of 0.1 to 5.0% by weight with respect to the carrier core material. Developer.   The toner according to claim 1, comprising a colorant in a range of 5 to 20% by weight.   The toner according to claim 1, wherein the toner contains a release agent in a range of 3 wt% to 10 wt%.   The toner particles having a particle diameter of 1.0 μm or less in the toner have a circularity of 0.96 or more, and the water content of the toner particles after the toner is left in a standard environment (25 ° C., indoor humidity 50%) for 48 hours. The toner according to claim 1, wherein the toner ratio is 1.0% or less.   The toner according to claim 1, wherein the toner is manufactured using a rotor / stator type wet disperser as one of the manufacturing apparatuses.   The developer according to claim 2, wherein the developer is manufactured using a rotor / stator type wet disperser as one of the manufacturing apparatuses.   7. The developing method using toner according to claim 1, wherein a bias voltage comprising a non-alternating component is applied to make the image visible.   8. The developing method using a developer according to claim 2, wherein a bias voltage comprising a non-alternating component is applied to make the image visible.   7. The developing method using toner according to claim 1, wherein a bias voltage composed of a direct current component is applied to make a visible image.   8. The developing method using a developer according to claim 2, wherein a bias voltage composed of a direct current component is applied to make the image visible.

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