JP2005250154A - Toner, its manufacturing method, two-component developer, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To produce toner of a small particle diameter having sharp grain size distribution without requiring a classifying process, and to provide the toner which can be negatively charged. <P>SOLUTION: A first resin particle dispersion liquid prepared by dispersing resin particles, a colorant particle dispersion liquid prepared by dispersing colorant particles, a wax particle dispersion liquid prepared by dispersing wax, and a second resin (charge controlling agent) containing an acryl-sulfonic acid copolymer having a sulfonic acid polar group are mixed and aggregated in an aqueous medium to obtain a toner mother material. To the toner mother material at least a part of which is melted by heating, inorganic fine powder having 6 nm to 200 nm average particle diameter is added by 1.0 to 6 parts by weight to 100 parts by weight of the toner mother material. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a toner used in a copying machine, a laser printer, plain paper FAX, a color PPC, a color laser printer, a color FAX, and a composite machine thereof, a manufacturing method thereof, a two-component developer, and an image forming apparatus.

  In recent years, the electrophotographic apparatus is shifting from the purpose of office use to personal use, and there is a demand for technology that realizes miniaturization, high speed, high image quality, maintenance-free operation, and the like. Therefore, use a cleaner-less process that collects waste toner during development without cleaning waste toner remaining after transfer, a tandem color process that enables high-speed output of color images, and fixing oil to prevent offset during fixing. Oilless fixing that achieves both a clear color image having high glossiness and high translucency and a non-offset property is required along with conditions such as good maintenance and low ozone exhaust. These functions need to be compatible at the same time, and not only the process but also the improvement in toner characteristics is an important factor.

  In a color printer, an image carrier (hereinafter referred to as a photoconductor) is charged by corona discharge by a charging charger, and then a latent image of each color is irradiated to the photoconductor as an optical signal to form an electrostatic latent image. The latent image is developed by developing with one color, for example, yellow toner. Thereafter, a transfer member charged with a polarity opposite to that of the yellow toner is brought into contact with the photosensitive member to transfer the yellow toner image formed on the photosensitive member. The photosensitive member is neutralized after cleaning the toner remaining at the time of transfer, and the development and transfer of the first color toner are completed. Thereafter, the same operation as yellow toner is repeated for toners such as magenta and cyan, and a color image is formed by superimposing toner images of respective colors on a transfer member. A four-pass color process in which these superimposed toner images are transferred onto paper charged to a polarity opposite to that of the toner has been put into practical use.

  In addition, a plurality of image forming stations having a charger, a photosensitive member, a developing unit, and the like are arranged side by side, an endless transfer member is brought into contact with the photosensitive member, and toners of respective colors are sequentially transferred to the transfer member sequentially. Executes the transfer process to form a multi-layer transfer color toner image on the transfer body, and then transfers the multi-layer toner image formed on the transfer body to a transfer medium such as paper or OHP at once. A tandem color process configured to execute the process, and a tandem color process for continuously transferring directly to a transfer medium of paper or an overhead projector (OHP) without using a transfer body have been proposed.

  In the fixing process, in color images, it is necessary to melt and mix color toners to improve translucency. When toner fusing failure occurs, light scattering occurs on the surface or inside of the toner image, and the original color tone of the toner dye is impaired. In addition, in the overlapping portion, light does not enter the lower layer and color reproducibility deteriorates. . Therefore, it is a necessary condition that the toner has a complete melting characteristic and a translucency that does not disturb the color tone. The need for light transparency on OHP paper is increasing with the increasing number of presentation opportunities in color.

  When a color image is obtained, toner adheres to the surface of the fixing roller to cause an offset, so that a large amount of oil or the like must be applied to the fixing roller, which complicates handling and the configuration of the device. For this reason, in order to reduce the size, maintain maintenance, and reduce the cost of the equipment, it is required to realize oilless fixing that does not use oil during fixing, which will be described later. In order to make this possible, a configuration in which a release agent such as wax is added to a binder resin having sharp melt characteristics is being put into practical use.

  However, the problem with such a toner configuration is that the toner has a high agglomeration characteristic, so that the tendency of toner image disturbance and transfer failure during transfer occurs more significantly, making it difficult to achieve both transfer and fixing. . When used as two-component development, the low melting point component of the toner adheres to the surface of the carrier due to collision between particles, friction, mechanical collision such as collision between particles and developer, friction, etc., or heat generated by friction. Spent is likely to occur, which lowers the charging ability of the carrier and hinders the long life of the developer.

  Patent Document 1 below proposes a carrier in which a fluorine-substituted alkyl group is introduced into a silicone resin of a coating layer for a positively charged toner. Further, Patent Document 2 below proposes a coating carrier containing a conductive carbon and a cross-linked fluorine-modified silicone resin, as it has a high development capability in a high-speed process and does not deteriorate in the long term. Has been. Taking advantage of the excellent charging characteristics of silicone resin, the fluorine-substituted alkyl group provides slipperiness, peelability, water repellency, etc., preventing wear, peeling, cracks, etc., and preventing spelling. However, wear, delamination, cracks, etc. are not satisfactory, and a positively charged toner can provide an appropriate charge amount, but a negatively charged toner is used. The charge amount was too low, and a large amount of reversely charged toner (toner having positive chargeability) was generated, resulting in deterioration such as fogging and toner scattering, and was not durable.

  Various configurations have been proposed for toner. As is well known, the toner for electrostatic charge development used in the electrophotographic method is generally a resin component which is a binder resin, a coloring component consisting of a pigment or a dye, a plasticizer, a charge control agent, and further if necessary. It is comprised by additional components, such as a mold release agent. As the resin component, natural or synthetic resins may be used alone or mixed in a timely manner.

  Then, the above additives are premixed at an appropriate ratio, heated and kneaded by heat melting, finely pulverized by an airflow type impact plate method, and finely classified to complete a toner base. There is also a method in which a toner base is prepared by a chemical polymerization method. Thereafter, an external additive such as hydrophobic silica is added to the toner base to complete the toner. In one-component development, the toner is composed only of toner, but a two-component developer can be obtained by mixing with toner and a carrier composed of magnetic particles.

  However, in the conventional pulverizing / classifying operation in the kneading and pulverizing method, the particle size that can be actually provided economically and in performance is about 8 μm even if the particle size is reduced. At present, methods for producing small-diameter toners by various methods are being studied. Also, a method for realizing oil-less fixing by blending a release agent such as wax in a resin having a low softening point when the toner is melt-kneaded has been studied. However, there is a limit to the amount of wax that can be blended, and as the amount added is increased, adverse effects such as a decrease in toner fluidity, an increase in voids during transfer, and an increase in fusion to the photoreceptor occur.

  Therefore, a toner production method using various polymerization methods different from the kneading and pulverization method has been studied. For example, when a toner is prepared by a suspension polymerization method, even if an attempt is made to control the particle size distribution of the toner, it cannot leave the range of the kneading and pulverization method, and in many cases, further classification operation is required. Further, since the toner obtained by these methods has a substantially spherical shape, there is a problem that the toner remaining on the photosensitive member or the like is very poorly cleaned and the image quality reliability is impaired.

  In addition, a toner preparation method using an emulsion polymerization method includes a step of forming aggregated particles in a dispersion obtained by dispersing at least resin particles to prepare an aggregated particle dispersion, and dispersing resin fine particles in the aggregated particle dispersion The resin fine particle dispersion thus prepared is added and mixed so that the resin fine particles are adhered to the aggregated particles to form the adhered particles, and the adhered particles are heated and fused.

  In the following Patent Document 3, at least a resin particle dispersion obtained by dispersing resin particles in a polar dispersant and a colorant particle dispersion obtained by dispersing colorant particles in a polar dispersant are mixed. A liquid mixture preparation step for preparing a liquid mixture, and by making the polarity of the dispersant contained in the liquid mixture the same polarity, a highly reliable electrostatic image developing toner excellent in chargeability and color development It is disclosed that it can be easily and conveniently manufactured.

  Moreover, in the following Patent Document 4, the release agent contains at least one ester composed of at least one of a higher alcohol having 12 to 30 carbon atoms and a higher fatty acid having 12 to 30 carbon atoms, and the resin particles include: It is disclosed that by including at least two kinds of resin particles having different molecular weights, the fixing property, color developing property, transparency, color mixing property and the like are excellent.

  Release agents include low molecular weight polyolefins such as polyethylene, polypropylene, and polybutene; fatty acid amides such as silicones, oleic acid amide, erucic acid amide, ricinoleic acid amide, stearic acid amide; carnauba wax, rice wax , Plant waxes such as candelilla wax, tree wax, jojoba oil; animal waxes such as beeswax; minerals such as montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, petroleum System waxes and their modifications are disclosed.

However, if the dispersibility is deteriorated by adding a release agent, color turbidity tends to occur in the toner image melted at the time of fixing. At the same time, the dispersibility of the pigment also deteriorates, and the color developability of the toner becomes insufficient. In addition, when the resin fine particles are further adhered and fused on the surface of the aggregate in the next step, the dispersion of the release agent or the like makes the adhesion of the resin fine particles unstable. Moreover, the release agent once aggregated with the resin is separated and released into the aqueous system. The dispersion of the release agent has a great influence on the agglomeration during mixing and agglomeration due to the polarity and melting point of the wax used. Furthermore, in order to realize oil-less fixing without using oil at the time of fixing, a specific wax is added in a large amount. And when it fuse | melts with resin from which melting | fusing point, a softening point, and viscoelasticity differ, it becomes difficult to unite | combine, maintaining a uniform state, when uniting by heating. In particular, it is possible to achieve both oil-less fixing, fogging during development, and transfer efficiency by using a release agent having a certain acid value and functional group. In the aqueous system, uniform mixing and aggregation with resin fine particles and pigment fine particles are hindered, and there is a tendency to increase the presence of a floating release agent that is not involved in aggregation in the aqueous system, and also in the pigment.
Japanese Patent No. 2801507 JP 2002-23429 A JP-A-10-198070 JP-A-10-301332

  The present invention provides a toner having a small particle size having a sharp particle size distribution, which is prepared without a classification step, and which can be negatively charged. Another object of the present invention is to create a toner that can uniformly agglomerate and attach the charge control particles and has a stable chargeability. Still another object of the present invention is to achieve both low temperature fixing, high temperature offset property and storage stability by using a release agent such as wax in the toner in oilless fixing without using oil in the fixing roller. That is. Still another object of the present invention is to provide a two-component developer having high durability and long life that does not deteriorate due to spenting even when used in combination with a toner containing a release agent such as wax. . Still another object of the present invention is to provide an image forming apparatus which can prevent a void or scatter during transfer and obtain high transfer efficiency.

  The toner of the present invention includes a first resin particle dispersion in which resin particles are dispersed, a colorant particle dispersion in which colorant particles are dispersed, a wax particle dispersion in which wax is dispersed, and a sulfonic acid-based toner. A second resin (charge control resin) containing an acrylic sulfonic acid-based copolymer having a polar group is mixed and aggregated in an aqueous system, and at least a part of the toner base is heated and melted. The inorganic fine powder in the range of ˜200 nm is added in the range of 1.0 to 6 parts by weight with respect to 100 parts by weight of the toner base.

Another toner of the present invention includes a first resin particle dispersion in which resin particles are dispersed, a colorant particle dispersion in which colorant particles are dispersed, and a wax particle dispersion in which wax is dispersed in an aqueous system. Mixed and agglomerated
A second resin (charge control resin) containing at least an acrylic sulfonic acid type copolymer having a sulfonic acid type polar group is heated and fused to the surface of at least a part of the particles which are heated and melted. An inorganic fine powder having an average particle diameter in the range of 6 nm to 200 nm is added to the toner base in an amount of 1.0 to 6 parts by weight with respect to 100 parts by weight of the toner base.

  The method for producing a toner of the present invention comprises at least a first resin particle dispersion in which first resin particles are dispersed in an aqueous medium, and an acrylic sulfonic acid copolymer having a sulfonic acid polar group. The second resin particle dispersion in which the charge control resin particles are dispersed, the colorant particle dispersion in which the colorant particles are dispersed, and the wax particle dispersion in which the wax particles are dispersed are mixed to obtain a mixed dispersion, and heated. An agglomeration treatment is performed to produce agglomerated particles in which at least the first resin particles, the second resin particles, the colorant particles, and the wax particles are agglomerated.

  Another method for producing the toner of the present invention includes a first resin particle dispersion in which at least first resin particles are dispersed, a colorant particle dispersion in which colorant particles are dispersed, and wax particles in an aqueous medium. And a wax particle dispersion in which the agglomerated particles are mixed and heated to agglomerate to produce agglomerated particles in which at least the first resin particles, the colorant particles and the wax particles are agglomerated, and the agglomerated particles are dispersed. The aggregated particle dispersion is mixed with a second resin particle dispersion in which second resin particles containing an acrylic sulfonic acid copolymer having at least a sulfonic acid polar group are dispersed, and heated. And a step of fusing the second resin particles to the surface of the aggregated particles.

  The two-component developer of the present invention comprises any one of the toners described above and a carrier containing magnetic particles coated with a fluorine-modified silicone resin including at least the surface of the core material containing an aminosilane coupling agent. .

  The image forming apparatus of the present invention has a plurality of toner image forming stations including at least an image carrier, a charging unit for forming an electrostatic latent image on the image carrier, and a toner carrier, and is formed on the image carrier. A transfer process is performed in which the electrostatic latent image is visualized with the toner or the two-component developer, and the toner images visualized with the electrostatic latent image are sequentially transferred onto a transfer medium. A transfer system configured as described above, wherein the transfer process includes a distance from the first transfer position to the second transfer position, a distance from the second transfer position to the third transfer position, or a third When the distance from the transfer position to the fourth transfer position is d1 (mm) and the peripheral speed of the photoreceptor is v (mm / s), the configuration satisfies the condition of d1 / v ≦ 0.65 (sec). It is characterized by being.

  Since the toner of the present invention contains the second resin (charge control resin), the toner can be negatively charged. In addition, a toner having a small particle size and a uniform and narrow particle size having a sharp particle size distribution can be prepared without a classification step. Also, oilless fixing can be realized by preventing low offset and fixing at low temperature without requiring oil application. Further, it is possible to realize a durable two-component developer that does not deteriorate due to spent even when used in combination with a toner containing wax. In addition, in a tandem color process that arranges image forming stations that have multiple photoconductors and development sections side by side, and sequentially transfers the toner of each color to the transfer body, it prevents omission and reverse transfer during transfer. High transfer efficiency can be obtained.

  The present invention is an oilless fixing that has high glossiness and high translucency, has high charging characteristics, environmental dependency, cleaning properties, transferability, and a small particle size electrostatic charge having a sharp particle size distribution. The present inventors have intensively studied to provide an image developing toner and a two-component developer, and to provide an image forming capable of forming a high-quality and highly reliable color image without toner scattering and fogging.

(1) Polymerization method The resin particle dispersion is prepared by subjecting the vinyl monomer to emulsion polymerization or seed polymerization in an ionic surfactant, thereby producing a vinyl monomer homopolymer or copolymer ( A dispersion liquid in which resin particles of vinyl resin) are dispersed in an ionic surfactant is prepared. As the means, for example, a high-speed rotating emulsifier, a high-pressure emulsifier, a colloid emulsifier, a ball mill having a medium, a sand mill, a dyno mill, and the like are known per se.

  When the resin in the resin particles is a resin other than the homopolymer or copolymer of the vinyl monomer, if the resin is dissolved in an oily solvent having a relatively low solubility in water, The resin is dissolved in the oily solvent, and the solution is finely dispersed in water together with an ionic surfactant and a polymer electrolyte using a disperser such as a homogenizer, and then heated or reduced in pressure to evaporate the oily solvent. As a result, a dispersion is prepared by dispersing resin particles made of resin other than vinyl resin in an ionic surfactant.

  As polymerization initiators, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2 , 2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile and other azo or diazo polymerization initiators, persulfates (potassium persulfate, ammonium persulfate, etc.), azo compounds (4,4′-azobis-4-cyanovaleric acid and its salt, 2,2′-azobis (2-amidinopropane) salt, etc.), peroxide compounds and the like.

  The colorant particle dispersion is prepared by adding colorant particles in water to which a polar surfactant is added and dispersing the particles using the above-described dispersion means.

  Wax is added to the toner of this embodiment. The toner according to the exemplary embodiment is obtained by mixing and aggregating a resin particle dispersion in which resin particles are dispersed in an aqueous medium, a colorant particle dispersion in which colorant particles are dispersed, and a wax particle dispersion in an aqueous system. Thus, a toner base is generated.

  At this time, after mixing and aggregation in the aqueous medium, the aqueous medium is heated. As a result, the melting of the wax having sharp melt properties starts, and the melted waxes start to aggregate. Although the glass transition point (Tg) of the resin is 30 to 70 ° C., even when the aqueous medium is at a temperature higher than the Tg of the resin, the resin does not start to melt sharply like wax, and the surface gradually melts. . Then, fine particles of resin and pigment are aggregated so as to surround the melted wax, and the aggregated resin is also melted and associated by heat. And the state in which the low melting point wax is encapsulated by the resin is formed.

  The toner base is prepared by dispersing a resin particle dispersion in which the above-described resin particles are dispersed, a colorant particle dispersion in which the colorant particles are dispersed, and a wax particle dispersion in which the above-described wax particles are dispersed in an aqueous medium. And adjusting the pH of the aqueous medium under a certain condition, and in the presence of an inorganic salt, the aqueous medium is heated to a temperature above the glass transition temperature (Tg) of the resin to agglomerate to form a toner base. .

  Specifically, in an aqueous medium, at least a first resin particle dispersion in which the first resin particles are dispersed, and a second acrylsulfonic acid copolymer having a sulfonic acid polar group. The second resin particle dispersion in which the resin particles are dispersed, the colorant particle dispersion in which the colorant particles are dispersed, and the wax particle dispersion in which the wax particles are dispersed are mixed and heated to aggregate.

  At this time, in order to uniformly disperse and aggregate the second resin particles in the aqueous medium without releasing them, the first resin particle dispersion in which the first resin particles are dispersed, the sulfonic acid-based polar group Second resin particle dispersion in which second resin particles containing an acrylic sulfonic acid-based copolymer having water content are dispersed, colorant particle dispersion in which colorant particles are dispersed, and wax particles in which wax particles are dispersed The dispersion liquid is mixed to prepare a mixed dispersion liquid having a pH of 6.0 or lower. For example, when potassium persulfate is used when polymerizing an emulsion polymerization resin, the residue may be decomposed by the heat at the time of heat aggregation to lower the pH. The pH can be lowered by applying an acid or by shifting to acidity with hydrochloric acid or the like.

  Thereafter, a water-soluble inorganic salt is added and heated to a temperature equal to or higher than the glass transition temperature (Tg) of the resin. Adjust to range. The pH can be adjusted by adding 1N NaOH.

  Thereafter, a water-soluble inorganic salt is added, and heat treatment is performed to form aggregated particles having a predetermined volume average particle diameter (3 to 6 μm) in which at least resin particles, colorant particles, and wax particles are aggregated. By setting the pH of the liquid when the aggregated particles having the predetermined volume average particle diameter to be in the range of 7.0 to 9.5, the second resin particles containing the acrylic sulfonic acid copolymer can be used. It is possible to form colored resin particles having a narrow particle size distribution in which the wax is hardly released and the wax is included. The amount of NaOH to be added, the type and amount of flocculant, the pH of the emulsion polymerization resin dispersion, the pH of the colorant dispersion, the pH of the wax dispersion, the heating temperature, and the time can be adjusted.

  When the pH at the time of preparing the mixed dispersion is higher than 6.0, when the colored resin particles are formed by heating, the pH fluctuation (decrease phenomenon) in the liquid becomes large and the particles become coarse.

  When adjusting the pH of the mixed dispersion before addition of the water-soluble inorganic salt and before heating, if it is lower than 9.5, the formed colored resin particles become coarse. When the pH is higher than 12.2, the release of the second resin particles containing the acrylic sulfonic acid copolymer and the wax increases, and it becomes difficult to encapsulate the wax uniformly.

  If the pH of the liquid when the aggregated particles are formed is less than 7.0, the colored particles are coarsened. When the pH exceeds 9.5, the second resin particles containing the acrylic sulfonic acid copolymer and wax are liberated due to poor aggregation.

  Further, in the aqueous medium, the first resin particle dispersion in which the first resin particles are dispersed, the colorant particle dispersion in which the colorant particles are dispersed, and the wax particle dispersion in which the wax particles are dispersed are mixed. The second resin particles containing the acrylic sulfonic acid copolymer were dispersed in the aggregated particle dispersion in which the aggregated particles in which the first resin particles, the colorant particles and the wax particles were aggregated by heat aggregation were dispersed. It is also possible to form a surface layer of a resin having a charging action by mixing the second resin particle dispersion and heat-sealing. Thereby, the charging property, durability, and offset property of the toner can be improved.

  A second resin surface fusion layer can be formed by attaching a second resin to the surface of the aggregated particles and heating to a temperature equal to or higher than the Tg of the second resin.

  It is necessary to uniformly attach the surface of the aggregated particles without releasing the second resin particles and preventing secondary aggregation of the aggregated particles.

  When a second resin particle dispersion in which a second resin particle containing an acrylic sulfonic acid copolymer having a sulfonic acid polar group is dispersed is added to the aggregated particle dispersion in which the aggregated particles are dispersed. Is adjusted to the range of 5.2 to 8.8, followed by heat treatment at a temperature equal to or higher than the glass transition temperature of the second resin particles for 0.5 to 2 hours, and then the pH is set to 3.2 to 2. After adjusting to the range of 6.8, heat treatment is performed at a temperature equal to or higher than the glass transition temperature of the second resin particles to fuse the second resin particles to the aggregated particles.

  The purpose of the heat treatment for 0.5 to 2 hours at a temperature equal to or higher than the glass transition temperature of the second resin particles after adjusting the pH to the range of 5.2 to 8.8 is to After uniformly adhering to the surface of the agglomerated particles, and then adjusting the pH to the range of 3.2 to 6.8, the heat treatment is further performed at a temperature equal to or higher than the glass transition temperature of the second resin particles. Without causing aggregation, particles having a narrow particle size distribution in which the second resin particles are fused to the aggregated particles can be obtained.

  When the pH when the second resin particle dispersion is added is lower than 5.2, adhesion of the second resin particles hardly occurs and free resin particles increase. When the pH is higher than 8.8, secondary aggregation between the aggregated particles tends to occur.

  If the pH after 0.5 to 2 hours of heat treatment is lower than 3.2, the resin particles once adhered may be released. When the pH is higher than 6.8, secondary aggregation of the aggregated particles tends to occur.

  The difference in volume average particle size between the aggregated particles and the particles in which the second resin particles are adhered and fused to the aggregated particles is preferably 0.5 to 2 μm. If it is smaller than 0.5 μm, the adhesion state of the second resin is poor, the influence of moisture and the strength of the second resin itself are insufficient. If it exceeds 2 μm, the fixing property and glossiness are lowered.

  Furthermore, if necessary, a third resin particle in which a third resin particle is further dispersed together with a second resin particle dispersion in which a second resin particle containing an acrylic sulfonic acid copolymer is dispersed. It is also preferable to mix the dispersion and heat-fuse.

  When forming a resin surface fusion layer by attaching a third resin to the surface of the agglomerated particles and heating to a temperature equal to or higher than the Tg of the third resin, the second and third resin particles are released. It is necessary to adhere to the surface of the aggregated particles uniformly without preventing secondary aggregation of the aggregated particles.

  At this time, the Tg of the third resin is preferably higher than the Tg of the second resin particles containing an acrylic sulfonic acid copolymer. This is because a strong resin layer is formed on the surface of the aggregated particles.

  The second resin particle dispersion in which the second resin particles containing the acrylic sulfonic acid copolymer having a sulfonic acid polar group are dispersed in the aggregated particle dispersion in which the aggregated particles are dispersed, and the third resin particle dispersion The pH when adding the third resin particle dispersion in which the resin particles are dispersed is adjusted to a range of 5.2 to 8.8, and then 0 at a temperature equal to or higher than the glass transition temperature of the third resin particles. After the heat treatment for 5 to 2 hours and then adjusting the pH to the range of 3.2 to 6.8, the heat treatment is further performed at a temperature equal to or higher than the glass transition temperature of the third resin particles, and the aggregated particles The second resin particles and the third resin particles are fused.

  After adjusting the pH to the range of 5.2 to 8.8, the purpose of the heat treatment for 0.5 to 2 hours at a temperature equal to or higher than the glass transition temperature of the third resin particles is to The third resin particles are uniformly attached to the surface of the aggregated particles, and then the pH is adjusted to a range of 3.2 to 6.8, and then heat treatment is performed at a temperature equal to or higher than the glass transition temperature of the third resin particles. By doing so, it is possible to obtain particles having a narrow particle size distribution in which the second resin particles and the third resin particles are fused to the aggregated particles without causing secondary aggregation.

  When the pH when the second and third resin particle dispersions are added is lower than 5.2, adhesion of the second and third resin particles hardly occurs, and free resin particles increase. When the pH is higher than 8.8, secondary aggregation between the aggregated particles tends to occur.

  If the pH after 0.5 to 2 hours of heat treatment is lower than 3.2, the resin particles once adhered may be released. When the pH is higher than 6.8, secondary aggregation of the aggregated particles tends to occur.

  The difference in volume average particle diameter between the aggregated particles and the particles in which the second and third resin particles are adhered and fused to the aggregated particles is preferably 0.5 to 2 μm. If it is smaller than 0.5 μm, the adhesion state of the second and third resins is poor, and the influence of moisture and the strength of the second and third resins themselves are insufficient. If it exceeds 2 μm, the fixing property and glossiness are lowered.

  Examples of water-soluble inorganic salts include alkali metal salts and alkaline earth metal salts. Examples of the alkali metal include lithium, potassium, and sodium, and examples of the alkaline earth metal include magnesium, calcium, strontium, and barium. Of these, potassium, sodium, magnesium, calcium, and barium are preferable. Examples of the counter ion (anion constituting the salt) of the alkali metal or alkaline earth metal include chloride ion, bromide ion, iodide ion, carbonate ion, and sulfate ion.

  Examples of the organic solvent infinitely soluble in water include methanol, ethanol, 1-propanol, 2-propanol, ethylene glycol, glycerin, acetone and the like. Among these, alcohols having 3 or less carbon atoms such as methanol, ethanol, 1-propanol, 2-propanol and the like are preferable, and 2-propanol is particularly preferable.

  Thereafter, the toner can be obtained through any washing step, solid-liquid separation step, and drying step. In this washing step, it is preferable to sufficiently perform substitution washing with ion-exchanged water from the viewpoint of improving the chargeability. There is no restriction | limiting in particular as a separation method in the said solid-liquid separation process, From a viewpoint of productivity, well-known filtration methods, such as a suction filtration method and a pressure filtration method, are mentioned preferably. There is no restriction | limiting in particular as a drying method in the said drying process, Well-known drying methods, such as a flash jet drying method, a fluidized drying method, and a vibration type fluidized drying method, are mentioned preferably from a viewpoint of productivity.

  Examples of the dispersant having polarity include an aqueous medium containing a polar surfactant. Examples of the aqueous medium include water such as distilled water and ion exchange water, and alcohols. These may be used individually by 1 type and may use 2 or more types together. The content of the polar surfactant in the dispersant having the polarity cannot be generally defined and can be appropriately selected according to the purpose.

  Examples of polar surfactants include anionic surfactants such as sulfate ester, sulfonate, phosphate, and soap, and cationic surfactants such as amine salt type and quaternary ammonium salt type. Can be mentioned.

  Specific examples of the anionic surfactant include sodium dodecylbenzenesulfonate, sodium dodecylsulfate, sodium alkylnaphthalenesulfonate, sodium dialkylsulfosuccinate and the like. Specific examples of the cationic surfactant include alkylbenzene dimethyl ammonium chloride, alkyl trimethyl ammonium chloride, distearyl ammonium chloride and the like. These may be used individually by 1 type and may use 2 or more types together.

  In the present invention, these polar surfactants and nonpolar surfactants can be used in combination. Examples of the nonpolar surfactant include nonionic surfactants such as polyethylene glycol, alkylphenol ethylene oxide adducts, and polyhydric alcohols.

  In order for the low melting point wax to be uniformly encapsulated in the resin without being desorbed and suspended during mixing and aggregation, the dispersion particle size distribution of the wax, the composition of the wax, and the melting characteristics of the wax are also affected.

  When using styrene-acrylic copolymer for resin particles, ester wax is used rather than vinyl wax such as polypropylene and polyethylene, so that the resin particles are not loosely separated and suspended during mixing and agglomeration. Can be encapsulated in a single location. It is possible to eliminate the influence of free wax, to prevent filming and carrier spent on OPC and transfer belt, and to effectively prevent omission and reverse transfer during transfer.

  The wax particle dispersion is prepared by heating, melting, and dispersing wax in ion-exchanged water in an aqueous medium to which a polar surfactant is added.

  At this time, the dispersed particle diameter of the wax is 20 to 200 nm for the 16% diameter (PR16), 40 to 300 nm for the 50% diameter (PR50), and 84% for the 84% diameter (PR84). ) Is 400 nm or less, PR84 / PR16 is emulsified and dispersed to a size of 1.2 to 2.0, and particles of 200 nm or less are preferably 65% by volume or more and particles exceeding 500 nm are preferably 10% by volume or less.

  Preferably, the 16% diameter (PR16) is 20 to 100 nm, the 50% diameter (PR50) is 40 to 160 nm, and the 84% diameter (PR84) is 260 nm or less when integrated from the small particle diameter side. PR84 / PR16 is 1.2 to 1.8. It is preferable that particles of 150 nm or less are 65 volume% or more and particles exceeding 400 nm are 10 volume% or less.

  More preferably, the 16% diameter (PR16) is 20 to 60 nm, the 50% diameter (PR50) is 40 to 120 nm, and the 84% diameter (PR84) is 220 nm or less when integrated from the small particle diameter side. , PR84 / PR16 is 1.2 to 1.8. It is preferable that particles of 130 nm or less are 65 volume% or more, and particles exceeding 300 nm are 10 volume% or less.

  When the resin particle dispersion, the colorant particle dispersion, and the wax particle dispersion are mixed and aggregated to form aggregate particles, the 50% diameter (PR50) is 20 to 200 nm, so that the wax is resin. It is easy to be taken in between particles, and aggregation between waxes can be prevented and dispersion can be performed uniformly. Particles that are taken into the resin particles and float in the water can be eliminated.

  Further, when the aggregate particles are obtained by heating the aggregate particles in an aqueous system, the molten resin particles surround and include the molten wax particles due to the surface tension, and the release agent is included in the resin. It becomes easy to be done.

  PR16 is larger than 160 nm, 50% diameter (PR50) is larger than 200 nm, PR84 is larger than 300 nm, PR84 / PR16 is larger than 2.0, particles of 200 nm or less are larger than 65% by volume and larger than 500 nm When the amount exceeds 10% by volume, the wax is difficult to be taken in between the resin particles, and agglomeration occurs only between the waxes. There is a tendency that particles that are not taken into the resin particles and float in water increase. When the aggregate particles are heated in an aqueous system to obtain fused aggregate particles, the melted resin particles are less likely to include the melted wax particles, and the wax is less likely to be included in the resin. In addition, when the resin is adhered and fused, the amount of wax that is exposed and released on the surface of the toner base increases, filming on the photoconductor, increased spent on the carrier, handling characteristics during development, and development memory are generated. It becomes easy.

  When PR16 is smaller than 20 nm, 50% diameter (PR50) is smaller than 40 nm, and PR84 / PR16 is smaller than 1.2, it is difficult to maintain a dispersed state, and reaggregation of wax occurs when left, and particle size distribution. The standing stability of is not good. In addition, the load increases during dispersion, heat generation increases, and productivity decreases.

  In addition, the 50% diameter (PR50) in the volume particle size integration when the wax particles dispersed in the wax particle dispersion are integrated from the small particle size side is the 50% diameter of the resin particles when forming the aggregate particles. By making it smaller than (PR50), it is easy for the wax to be taken in between the resin particles, and aggregation between the waxes can be prevented, and the dispersion can be performed uniformly. Particles that are taken into the resin particles and float in the water can be eliminated. When the aggregated particles are obtained by heating the aggregated particles in an aqueous system to obtain fused aggregated particles, the melted resin particles include the melted wax particles because of the surface tension, and the wax is easily included in the resin. More preferably, it is 20% or more smaller than the 50% diameter (PR50) of the resin particles.

  A rotating body in which a wax melt obtained by melting the wax at a wax concentration of 40 wt% or less is rotated at a high speed through a fixed gap with a fixed gap in a medium to which a dispersant maintained at a temperature higher than the melting point of the wax is added. The wax particles can be finely dispersed by emulsifying and dispersing by the action of high shear force generated by the above.

  3 and 4, a gap of about 0.1 mm to 10 mm is provided in the tank wall in the tank of a certain capacity, and the rotating body is 30 m / s or more, preferably 40 m / s or more, more preferably 50 m / s or more. By rotating at a high speed, a strong shearing force acts on the aqueous system, and an emulsified dispersion having a fine particle size can be obtained. The dispersion can be formed by a treatment time of about 30 seconds to 5 minutes.

  A rotating body that rotates at a speed of 30 m / s or more, preferably 40 m / s or more, more preferably 50 m / s or more, with a gap of about 1 to 100 μm provided to a fixed stationary body as shown in FIGS. By adding a strong shearing force action, a fine dispersion can be created.

  Compared with a high-pressure disperser such as a high-pressure homogenizer, the particle size distribution of fine particles can be made narrower and sharper. Further, even when left for a long time, the fine particles forming the dispersion do not reaggregate and can maintain a stable dispersion state, and the standing stability of the particle size distribution is improved.

  When the melting point of the wax is high, a molten liquid is prepared by heating in a high pressure state. Also, the wax is dissolved in an oily solvent. This solution is obtained by dispersing fine particles in water together with a surfactant and a polymer electrolyte using the disperser shown in FIGS. 3, 4, 5 and 6, and then evaporating the oily solvent by heating or decompressing. You can also

  The particle size can be measured using a Horiba laser diffraction particle size measuring device (LA920), a Shimadzu laser diffraction particle size measuring device (SALD2100), or the like.

(2) Wax Ester wax is preferably used as the wax added to the toner of the present embodiment. As the wax, a wax having an iodine value of 25 or less and a saponification value of 30 to 300 is preferable. The repulsion due to the charge effect of the toner during the multi-layer transfer of toner can be alleviated, so that the transfer efficiency can be reduced, the character dropout during transfer and reverse transfer can be suppressed. In addition, the use in combination with a carrier described later can suppress the occurrence of spent on the carrier and can extend the life of the developer. Further, the handling property in the developing device is improved, and the uniformity of the image is improved on the rear side and the front side of the development. Further, development memory generation can be reduced.

  When the iodine value exceeds 25, the mixing and cohesiveness in the aqueous system deteriorates, the uniform dispersibility decreases, and color turbidity occurs. If the suspended matter increases and remains in the toner, filming of the photoreceptor or the like occurs. The repulsion due to the charge effect of the toner is difficult to be mitigated during the multi-layer transfer of toner in the primary transfer. The environmental dependency is large, and the change in the charging property of the material becomes large during long-term continuous use, which hinders the stability of the image. Development memory is also likely to occur. When the saponification value is less than 30, the presence of unsaponifiable matter and hydrocarbons increases, and photoconductor filming and chargeability are deteriorated. It causes a decrease in chargeability during filming and continuous use. When the saponification value exceeds 300, the wax dispersibility with the resin at the time of mixing and aggregation deteriorates. The repulsion due to the charge action of the toner is less likely to be alleviated. In addition, fog and toner scattering increase.

  The heat loss of the wax at 220 ° C. is preferably 8% by weight or less. When the loss on heating exceeds 8% by weight, the glass transition point of the toner is lowered and the storage stability of the toner is impaired. It adversely affects the development characteristics and causes fogging and photoconductor filming. The particle size distribution when emulsified and dispersed particles are generated becomes broad.

Molecular weight characteristics in gel permeation chromatography (GPC), number average molecular weight is 100 to 5000, weight average molecular weight is 200 to 10,000, and ratio of weight average molecular weight to number average molecular weight (weight average molecular weight / number average molecular weight) is 1.01 to 1.01. 8. The ratio of Z-average molecular weight to number-average molecular weight (Z-average molecular weight / number-average molecular weight) is 1.02 to 10, and the molecular weight is 5 × 10 ² to 1 × 10 ⁴ and has at least one molecular weight maximum peak. Preferably it is. More preferably, the number average molecular weight is 500-4500, the weight average molecular weight is 600-9000, the ratio of weight average molecular weight to number average molecular weight (weight average molecular weight / number average molecular weight) is 1.01-7, Z average molecular weight and number average. The molecular weight ratio (Z average molecular weight / number average molecular weight) is 1.02 to 9, more preferably the number average molecular weight is 700 to 4000, the weight average molecular weight is 800 to 8000, and the ratio of the weight average molecular weight to the number average molecular weight (weight average). (Molecular weight / number average molecular weight) is 1.01 to 6, and the ratio of Z average molecular weight to number average molecular weight (Z average molecular weight / number average molecular weight) is 1.02 to 8.

When the number average molecular weight is smaller than 100, the weight average molecular weight is smaller than 200, and the molecular weight maximum peak is located in a range smaller than 5 × 10 ² , the storage stability is deteriorated. Further, the handling property in the developing device is lowered, and the toner density uniformity is inhibited. In addition, toner photoconductor filming occurs. Furthermore, the particle size distribution at the time of emulsified dispersion particle generation becomes broad.

The number average molecular weight is greater than 5000, the weight average molecular weight is greater than 10,000, the ratio of the weight average molecular weight to the number average molecular weight (weight average molecular weight / number average molecular weight) is greater than 8, and the ratio of the Z average molecular weight to the number average molecular weight (Z When the average molecular weight / number average molecular weight) is larger than 10 and the molecular weight maximum peak is located in a range larger than the region of 1 × 10 ⁴ , the releasing action is weakened, and fixing properties such as fixing property and offset resistance are reduced. Function declines. Moreover, it becomes difficult to reduce the particle diameter of the generated particles when the emulsified dispersed particles are generated. Furthermore, the encapsulation of wax in the resin tends not to be uniform.

  An endothermic peak temperature (melting point Tmw) by DSC method is preferably 50 to 100 ° C. Preferably it is 55-95 degreeC, More preferably, it is 65-85 degreeC. When the temperature is less than 50 ° C., the storage stability of the toner deteriorates. When the temperature exceeds 100 ° C., it is difficult to reduce the particle size of the generated particles when the emulsified dispersed particles are generated. It becomes difficult to uniformly encapsulate the wax in the resin.

  Furthermore, the material whose volume increase rate at the time of 10 degreeC change at the temperature more than melting | fusing point is 2 to 30% is preferable. When it changes from solid to liquid when it melts with heat during fixing, the adhesion between the toners is further strengthened, the fixing property is further improved, and the releasability from the fixing roller is also improved. Offset property is also improved. The addition amount is preferably 2 to 90 parts by weight with respect to 100 parts by weight of the binder resin. Preferably, 5 to 80 parts by weight, more preferably 10 to 50 parts by weight, and still more preferably 15 to 20 parts by weight is added to 100 parts by weight of the binder resin. If it is less than 2 parts by weight, the effect of improving the fixing property cannot be obtained, and if it exceeds 90 parts by weight, there is a problem in storage stability.

  As the wax, materials such as meadow foam oil, carnauba wax derivatives, jojoba oil, wood wax, beeswax, ozokerite, carnauba wax, canderia wax, ceresin wax, rice wax, etc. are preferable, and these derivatives are also preferably used. Is done. It is also possible to use one type or a combination of two or more types. In particular, carnauba wax having a melting point of 76-90 ° C., candelilla wax having 66-80 ° C., hydrogenated jojoba oil having 64-78 ° C., hydrogenated meadowfoam oil having 74-78 ° C. or 74 At least one or two or more kinds of waxes selected from the group consisting of rice waxes having a temperature of ˜90 ° C. are more preferable.

  Saponification value refers to the number of milligrams of potassium hydroxide KOH required to saponify 1 g of a sample. This is the sum of acid value and ester value. To determine the saponification value, a sample is saponified in an alcohol solution of about 0.5 N potassium hydroxide, and then excess potassium hydroxide is titrated with 0.5 N hydrochloric acid.

  The iodine value refers to the amount of halogen absorbed when halogen is allowed to act on a sample, and expressed in terms of g relative to 100 g of the sample. This is the number of grams of iodine absorbed by 100 g of fat, and the higher this value, the higher the degree of unsaturation of the fatty acid in the sample. Add iodine and mercury (II) chloride alcohol solution or iodine glacial acetic acid solution to chloroform or carbon tetrachloride solution of the sample, and titrate the remaining iodine without reacting with sodium thiosulfate standard solution to absorb iodine Calculate the amount.

For the measurement of the loss on heating, the sample cell weight is precisely weighed to 0.1 mg (W ₁ mg), and 10 to 15 mg of the sample is put therein, and then weighed to 0.1 mg (W ₂ mg). The sample cell is set on a differential thermobalance, and the measurement is started with a weighing sensitivity of 5 mg. After the measurement, the weight loss when the sample temperature reaches 220 ° C. is read to 0.1 mg by the chart (W ₃ mg). The apparatus is TGD-3000 manufactured by Vacuum Riko Co., Ltd., the heating rate is 10 ° C./min, the maximum temperature is 220 ° C., the holding time is 1 min, and loss on heating (%) = [W ₃ / (W ₂ −W ₁ )] × 100. Thereby, it is possible to improve the translucency in the color image and to improve the resistance to offset to the roller. Further, the occurrence of spent on the carrier can be suppressed, and the life of the developer can be extended.

  Also, a wax obtained by reacting a long-chain alkyl alcohol having 4 to 30 carbon atoms with an unsaturated polyvalent carboxylic acid or an anhydride thereof and an unsaturated hydrocarbon wax, or a long-chain alkylamine and an unsaturated polyvalent carboxylic acid Or a wax obtained by reaction of an anhydride thereof with an unsaturated hydrocarbon wax, or a wax obtained by reaction of a long-chain fluoroalkyl alcohol with an unsaturated polycarboxylic acid or an anhydride thereof and an unsaturated hydrocarbon wax. Can also be suitably used. As a result, the release action by the long chain alkyl is enhanced, the dispersion phase with the resin by the ester group is improved, and the durability and offset property are improved by the vinyl bond.

In the molecular weight distribution in GPC of this wax, the weight average molecular weight is 1000 to 6000, the Z average molecular weight is 1500 to 9000, and the ratio of the weight average molecular weight to the number average molecular weight (weight average molecular weight / number average molecular weight) is 1.1 to 3. 8. The ratio of Z-average molecular weight to number-average molecular weight (Z-average molecular weight / number-average molecular weight) has at least one molecular weight maximum peak in the region of 1.5 to 6.5, 1 × 10 ^{3 to} 3 × 10 ⁴ The penetration value at an acid value of 10 to 80 mgKOH / g, a melting point of 50 to 120 ° C. and 25 ° C. is preferably 4 or less.

More preferably, the weight average molecular weight is 1000 to 5000, the Z average molecular weight is 1700 to 8000, the ratio of the weight average molecular weight to the number average molecular weight (weight average molecular weight / number average molecular weight) is 1.1 to 2.8, and the Z average molecular weight is The number average molecular weight ratio (Z average molecular weight / number average molecular weight) is at least one molecular weight maximum peak in the region of 1.5 to 4.5 and 1 × 10 ³ to 1 × 10 ⁴ , and the acid value is 10 to 50 mgKOH. / G, melting point 60-110 ° C. More preferably, the weight average molecular weight is 1000 to 2500, the Z average molecular weight is 1900 to 3000, the ratio of the weight average molecular weight to the number average molecular weight (weight average molecular weight / number average molecular weight) is 1.2 to 1.8, and the Z average molecular weight is The number average molecular weight ratio (Z average molecular weight / number average molecular weight) is in the region of 1.7 to 2.5, 1 × 10 ^{3 to} 3 × 10 ³ , and has at least one molecular weight maximum peak, and an acid value of 35 to 50 mgKOH / G, melting point 65-95 ° C. Thereby, non-offset property and high glossiness in oilless fixing, and high translucency of OHP can be expressed, and high temperature storage stability is not deteriorated. In an image in which three layers of color toner are formed on thin paper, this is particularly effective for improving the paper separation from the fixing roller and belt.

  Further, uniform dispersion with a resin pigment is possible by dispersion and mixed aggregation in a specific polar dispersant described later, and the presence of suspended solids is eliminated, thereby suppressing color turbidity. Further, when the subsequent resin is further adhered and fused, the release of the wax is difficult to occur. Further, even if a fluorine-based or silicone-based member is used for the fixing roller, the offset of the halftone image can be prevented.

  Use in combination with a carrier, which will be described later, can suppress the generation of spent as well as oilless fixing, extend the life of the developer, maintain uniformity in the developing device, and suppress the occurrence of development memory. Furthermore, charging stability during continuous use can be obtained, and both fixing property and development stability can be achieved.

  Here, when the carbon number of the long-chain alkyl of the wax is less than 4, the releasing action is weakened, and the separation property and the high temperature non-offset property are deteriorated. When the carbon number of the long-chain alkyl exceeds 30, the mixed aggregation property with the resin is deteriorated and the dispersibility is lowered. When the acid value is less than 10 mgKOH / g, the charge amount during long-term use of the toner is reduced. When the acid value exceeds 80 mgKOH / g, the moisture resistance decreases, the fogging under high humidity increases, and it becomes difficult to reduce the particle size of the produced particles when the emulsified dispersed particles are produced. Moreover, the encapsulation of wax in the resin tends not to be uniform.

  When the melting point is less than 50 ° C., the storage stability of the toner is lowered. When the melting point exceeds 120 ° C., the releasing action is weakened and the non-offset temperature range is narrowed. In addition, it is difficult to reduce the size of the generated particles when generating the emulsified dispersed particles. Moreover, it becomes difficult to make the wax encapsulated in the resin uniform.

  When the penetration at 25 ° C. exceeds 4, the toughness is lowered and the photoreceptor filming occurs during long-term use.

Weight average molecular weight smaller than 1000, Z average molecular weight smaller than 1500, Weight average molecular weight / number average molecular weight smaller than 1.1, Z average molecular weight / number average molecular weight smaller than 1.5, molecular weight maximum peak Is located in a range smaller than 1 × 10 ³ , the storage stability of the toner is lowered, and filming occurs on the photosensitive member and the intermediate transfer member. Further, the handling property in the developing device is lowered, and the uniformity of the toner density is lowered. Also, development memory is likely to occur. The particle size distribution of the produced particles at the time of producing the emulsified dispersed particles at the time of the action of a high shearing force by high-speed rotation becomes a load.

The weight average molecular weight is greater than 6000, the Z average molecular weight is greater than 9000, the weight average molecular weight / number average molecular weight is greater than 3.8, the Z average molecular weight / number average molecular weight is greater than 6.5, and the molecular weight maximum If the peak is located in a range larger than the region of 3 × 10 ⁴ , the releasing action is weakened and the fixing offset property is lowered. It becomes difficult to reduce the particle size of the generated particles when the emulsified dispersed particles are generated. Moreover, the encapsulation of wax in the resin tends not to be uniform.

Alcohols include octanol (C ₈ H ₁₇ OH), dodecanol (C ₁₂ H ₂₅ OH), stearyl alcohol (C ₁₈ H ₃₇ OH), nonacosanol (C ₂₉ H ₅₉ OH), pentadecanol (C ₁₅ H ₃₁ OH) Those having an alkyl chain having 4 to 30 carbon atoms, such as, can be used. Moreover, N-methylhexylamine, nonylamine, stearylamine, nonadecylamine, etc. can be used conveniently as amines. As the fluoroalkyl alcohol, 1-methoxy- (perfluoro-2-methyl-1-propene), hexafluoroacetone, 3-perfluorooctyl-1,2-epoxypropane and the like can be preferably used. As the unsaturated polyvalent carboxylic acid or anhydride thereof, one or more of maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride and the like can be used. Of these, maleic acid and maleic anhydride are more preferable. As the unsaturated hydrocarbon wax, ethylene, propylene, α-olefin and the like can be suitably used.

  Unsaturated polyhydric carboxylic acid or its anhydride is polymerized with alcohol or amine, and this is then added to synthetic hydrocarbon wax in the presence of dicrummi peroxide or tertiary butyl peroxyisopropyl monocarbonate. Can be obtained.

  The addition amount is preferably 2 to 90 parts by weight with respect to 100 parts by weight of the binder resin. Preferably, 5 to 50 parts by weight, more preferably 10 to 30 parts by weight, and further preferably 15 to 20 parts by weight are added to 100 parts by weight of the binder resin. When the addition amount is less than 2 parts by weight, the effect of improving the fixing property cannot be obtained, and when it exceeds 90 parts by weight, there is a problem in storage stability.

(3) Resin Examples of the resin fine particles of the toner of the present embodiment include a thermoplastic binder resin. Specifically, styrenes such as styrene, parachlorostyrene, and α-methylstyrene; acrylic monomers such as methyl acrylate, ethyl acrylate, n-propyl acrylate, lauryl acrylate, and 2-ethylhexyl acrylate; Methacrylic monomers such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate; and ethylenically unsaturated acids such as acrylic acid, methacrylic acid, sodium styrenesulfonate Vinyl nitriles such as acrylonitrile and methacrylonitrile; vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone and vinyl isopropenyl ketone; ethylene, Homopolymers such as monomers such as olefins such as lopyrene and butadiene, copolymers obtained by combining two or more of these monomers, or mixtures thereof, and epoxy resins, polyester resins, polyurethane resins, Polyamide resins, cellulose resins, polyether resins, etc., non-vinyl condensation resins, or mixtures of these with vinyl resins, graft polymers obtained by polymerizing vinyl monomers in the presence of these resins, etc. Can be mentioned.

  Among these resins, vinyl resins are particularly preferable. In the case of a vinyl resin, it is advantageous in that a resin particle dispersion can be easily prepared by emulsion polymerization or seed polymerization using an ionic surfactant or the like. Examples of the vinyl monomer include acrylic acid, methacrylic acid, maleic acid, cinnamic acid, fumaric acid, vinyl sulfonic acid, ethylene imine, vinyl pyridine, vinyl amine, and other vinyl polymer acids and vinyl polymer bases. The monomer used as a raw material is mentioned. In the present invention, the resin particles preferably contain the vinyl monomer as a monomer component. In the present invention, among these vinyl monomers, vinyl polymer acids are more preferable from the viewpoint of ease of formation reaction of vinyl resins, and specifically, acrylic acid, methacrylic acid, maleic acid, cinnamon. A dissociable vinyl monomer having a carboxyl group such as an acid or fumaric acid as a dissociating group is particularly preferred from the viewpoint of controlling the degree of polymerization and the glass transition point.

  The content of the resin particles in the resin particle dispersion is usually 5 to 50% by weight, preferably 10 to 30% by weight. The molecular weights of the resin, wax, and toner are values measured by gel permeation chromatography (GPC) using several types of monodisperse polystyrene as standard samples.

  The apparatus is HPLC 8120 series manufactured by Tosoh Corporation, the column is TSKgel superHM-H H4000 / H3000 / H2000 (7.8 mm diameter, 150 mm × 3), eluent THF (tetrahydrofuran), flow rate 0.6 ml / min, sample concentration 0.1 %, Injection amount 20 μL, detector RI, measurement temperature 40 ° C., pretreatment for measurement is to measure a resin component obtained by dissolving a sample in THF and filtering through a 0.45 μm filter to remove additives such as silica. The measurement conditions are conditions in which the molecular weight distribution of the target sample is included in a range in which the logarithm of the molecular weight and the count number are linear in a calibration curve obtained with several types of monodisperse polystyrene standard samples.

  In addition, the measurement of the wax obtained by the reaction with a long chain alkyl alcohol having 4 to 30 carbon atoms, an unsaturated polyvalent carboxylic acid or its anhydride, and an unsaturated hydrocarbon wax was performed using a GPC-150C manufactured by WATERS. Shodex HT-806M (8.0 mm ID-30 cm × 2), eluent is o-dichlorobenzene, flow rate is 1.0 mL / min, sample concentration is 0.3%, injection volume is 200 μL, detector is RI The measurement temperature was 130 ° C., and the pre-measurement treatment was performed by filtering the sample with a 0.5 μm sintered metal filter after dissolving the sample in a solvent. The measurement conditions are conditions in which the molecular weight distribution of the target sample is included in a range in which the logarithm of the molecular weight and the count number are linear in a calibration curve obtained with several types of monodisperse polystyrene standard samples.

The softening point of the binder resin was about 9.8 with a plunger while heating a 1 cm ³ sample at a heating rate of 6 ° C./min with a constant-load extrusion type capillary rheometer flow tester (CFT500) manufactured by Shimadzu Corporation. Applying a load of × 10 ⁵ N / m ² , pushing out from a die with a diameter of 1 mm and a length of 1 mm, the piston stroke starts to rise from the relationship between the temperature rise characteristic of the plunger stroke and temperature. The temperature is the outflow start temperature (Tfb), 1/2 of the difference between the lowest value of the curve and the end point of the outflow, and the temperature at the point where the minimum value of the curve is added is the melting temperature (softening point) in the 1/2 method. Tm).

In addition, the glass transition point of the resin was measured by using a differential scanning calorimeter (Shimadzu DSC-50), heated to 100 ° C., allowed to stand at that temperature for 3 minutes, and then cooled to room temperature at a cooling rate of 10 ° C./min. When the thermal history is measured by heating at a heating rate of 10 ° C./min, the maximum slope between the baseline extension line below the glass transition point and the peak rising portion to the peak apex is shown. Says the temperature at the intersection with the tangent.
The melting point of the endothermic peak by DSC of the wax was 5 ° C / min using a differential scanning calorimeter (Shimadzu DSC-50), heated to 200 ° C, rapidly cooled to 10 ° C for 5 minutes, then allowed to stand for 15 minutes. The temperature was raised at ° C./min, and the endothermic (melting) peak was obtained. The amount of sample put into the cell was 10 mg ± 2 mg.

(4) Charge Control Agent In this embodiment, charged fine particles are added for the purpose of toner charge control. As a preferable material, a polymer or copolymer having a sulfonic acid group is preferable, a copolymer having an acrylamide sulfonic acid monomer is more preferable, and 2-acrylamido-2-methylpropane is particularly preferable. A copolymer having a sulfonic acid monomer.

  The acrylic sulfonic acid copolymer is preferably a vinyl copolymer of an aromatic vinyl monomer and an acrylic acid monomer having a sulfonic acid group as a polar group. In particular, a copolymer having a styrene monomer and a 2-acrylamido-2-methylpropanesulfonic acid monomer is preferable.

  Furthermore, the acrylic sulfonic acid polymer is preferably a copolymer of an aromatic vinyl monomer, a (meth) acrylic acid ester monomer, and an acrylic acid monomer having a sulfonic acid group as a polar group. In particular, styrene monomers as aromatic vinyl monomers, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, acrylic as (meth) acrylic acid ester monomers Acrylic acid ester monomers such as lauryl acid and stearyl acrylate are preferred. Copolymers obtained by polymerizing styrene and 2-ethylhexyl acrylate or copolymers obtained by polymerizing styrene and (n) butyl acrylate Particularly preferred is a coalescence.

  As the monomer having a sulfonic acid group, 2-acrylamido-2-methylpropanesulfonic acid and 2-methacrylamide-2-methylpropanesulfonic acid are preferable.

  The weight ratio of the styrene monomer and the (meth) acrylic acid ester monomer is preferably 9: 1 to 6: 4. Improved dispersion in the resin and good productivity.

  The acrylic sulfonic acid monomer is preferably 10 to 60 parts by weight with respect to 100 parts by weight of the binder resin by mass ratio. More preferably, it is 20-50 weight part, More preferably, it is 30-50 weight part. When the amount exceeds 60 parts by weight, it is difficult to impart sufficient frictional charging ability to the toner, and when the amount is less than 10 parts by weight, the toner is not preferably dispersed uniformly in the binder resin.

  The addition amount of the acrylic sulfonic acid copolymer is preferably 1 to 10 parts by mass, more preferably 1 to 5 parts by mass, and still more preferably 1 to 2 parts by mass with respect to 100 parts by mass of the binder resin. It is good to contain. If the range is out of range, the charge control becomes difficult.

The acrylic sulfonic acid polymer having a sulfonic acid polar group has a weight average molecular weight of 3 × 10 ³ to 8 × 10 ⁴ and a Z average molecular weight of 5 × 10 ^{3 to} 5 × in GPC of THF-soluble matter. 10 ⁵ , the ratio of weight average molecular weight to number average molecular weight (weight average molecular weight / number average molecular weight) is 1.5 to 50, and the ratio of Z average molecular weight to number average molecular weight (Z average molecular weight / number average molecular weight) is 5 to 100. A polymer having at least one molecular weight maximum peak in a region of 4 × 10 ³ to 8 × 10 ⁴ and an acid value of 8 to 50 mgKOH / g is preferable.

When the weight average molecular weight is less than 3 × 10 ³ , the Z average molecular weight is less than 5 × 10 ³ , the weight average molecular weight / number average molecular weight) is less than 1.5, and the Z average molecular weight / number average molecular weight is less than 20, Filming on the photoreceptor is likely to occur. Furthermore, spent adhesion to the carrier and fusion to the intermediate transfer belt increase.

Further, when the weight average molecular weight is larger than 8 × 10 ⁴ , the Z average molecular weight is larger than 5 × 10 ⁵ , the weight average molecular weight / number average molecular weight is larger than 50, and the Z average molecular weight / number average molecular weight is larger than 100, the fixing property is increased. Inhibits. If the acid value is less than 8 mgKOH / g, the charging ability cannot be exhibited, and toner scattering, transfer failure, and fogging increase. On the other hand, if the acid value is larger than 50 mgKOH / g, the charge-up becomes too large and the image density is lowered during continuous use.

  The second resin particles containing an acrylic sulfonic acid copolymer having a sulfonic acid polar group preferably have a median diameter of 0.1 to 1 μm. It can be produced by emulsion polymerization similar to the method for producing the resin fine particles described above, or a method of producing a dispersion by melting the polymer at a high temperature. When the particle diameter exceeds 1 μm, the particle size distribution of the obtained toner is broadened or free particles are generated, which tends to cause deterioration in performance and reliability. On the other hand, when the median diameter is within the above range, there are no disadvantages, and the uneven distribution among the toners is reduced, the dispersion in the toner is improved, and the variation in performance and reliability is advantageous.

(5) Pigment Examples of the colorant (pigment) used in this embodiment include carbon black, iron black, graphite, nigrosine, azo dye metal complexes, C.I. I. Acetoacetic acid arylamide monoazo yellow pigments such as CI Pigment Yellow 1,3,74,97,98; I. Acetoacetic acid arylamide disazo yellow pigments such as C.I. Pigment Yellow 12, 13, 14, and 17; I. Solvent Yellow 19, 77, 79, C.I. I. Disperse Yellow 164 is blended, and C.I. I. Benzimidazolone pigments of CI Pigment Yellow 93, 180 and 185 are preferred.

  C. I. Red pigments such as CI Pigment Red 48, 49: 1, 53: 1, 57, 57: 1, 81, 122, 5; I. Red dyes such as Solvent Red 49, 52, 58, 8; I. One or two or more kinds of blue dyed pigments of phthalocyanine and derivatives thereof such as Pigment Blue 15: 3 are blended. The addition amount is preferably 3 to 8 parts by weight with respect to 100 parts by weight of the binder resin.

  The median diameter of each particle is usually 1 μm or less, preferably 0.01 to 1 μm. When the median diameter exceeds 1 μm, the particle size distribution of the finally obtained toner for developing an electrostatic charge image is broadened, or free particles are generated, which easily deteriorates performance and reliability. On the other hand, when the median diameter is within the above range, there are no disadvantages, and the uneven distribution among the toners is reduced, the dispersion in the toner is improved, and the variation in performance and reliability is advantageous. The median diameter can be measured using, for example, a Horiba laser diffraction particle size measuring instrument (LA920).

(6) External additive In this embodiment, as an external additive, metal oxide fine powders such as silica, alumina, titanium oxide, zirconia, magnesia, ferrite, and magnetite, barium titanate, calcium titanate, strontium titanate, etc. A zirconate such as titanate, barium zirconate, calcium zirconate, strontium zirconate or a mixture thereof is used. The external additive is hydrophobized as necessary.

  As the silicone oil-based material treated with silica, those shown in (Chemical Formula 3) are preferable.

  For example, dimethyl silicone oil, methyl hydrogen silicone oil, methyl phenyl silicone oil, cyclic dimethyl silicone oil, epoxy modified silicone oil, carboxyl modified silicone oil, carbinol modified silicone oil, methacryl modified silicone oil, mercapto modified silicone oil, polyether modified Silica treated with at least one of silicone oil, methylstyryl-modified silicone oil, alkyl-modified silicone oil, fluorine-modified silicone oil, amino-modified silicone oil, and chlorophenyl-modified silicone oil is preferably used. For example, SH200, SH510, SF230, SH203, BY16-823, BY16-855B, etc. manufactured by Toray Dow Corning Silicone may be mentioned. For the treatment, a method of mixing inorganic fine powder and a material such as silicone oil with a mixer such as a Henschel mixer, a method of spraying a silicone oil-based material onto silica, or a solution in which a silicone oil-based material is dissolved or dispersed in a solvent Then, after mixing with silica fine powder, there is a method of removing the solvent to prepare. It is preferable that 1 to 20 parts by weight of the silicone oil-based material is blended with respect to 100 parts by weight of the inorganic fine powder.

  As silane coupling agents, dimethyldichlorosilane, trimethylchlorosilane, allyldimethylchlorosilane, hexamethyldisilazane, allylphenyldichlorosilane, benzylmethylchlorosilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, There are vinyltriacetoxysilane, divinylchlorosilane, dimethylvinylchlorosilane, and the like. The silane coupling agent treatment is a dry treatment in which the vaporized silane coupling agent is reacted with a fine powder made into a cloud by stirring or the like, or a wet treatment in which a silane coupling agent in which the fine powder is dispersed in a solvent is dropped. Processed by law.

  It is also preferable to treat the silicone oil-based material after the silane coupling treatment.

  The inorganic fine powder having positive electrode chargeability is treated with aminosilane, amino-modified silicone oil or epoxy-modified silicone oil represented by the following formula (Formula 4).

  Moreover, in order to improve hydrophobic treatment, the combined use of treatment with hexamethyldisilazane, dimethyldichlorosilane, or other silicone oil is also preferable. For example, it is preferable to treat with at least one of dimethyl silicone oil, methylphenyl silicone oil, and alkyl-modified silicone oil.

It is also preferable to treat the surface of the inorganic fine powder with a fatty acid ester, a fatty acid amide, or a fatty acid metal salt. Silica or titanium oxide fine powder obtained by surface-treating any one kind or two or more kinds is more preferred.
Examples of fatty acid and fatty acid metal salts include caprylic acid, capric acid, undecyl acid, lauric acid, myristylic acid, parimitic acid, stearic acid, behenic acid, montanic acid, laccellic acid, oleic acid, erucic acid, sorbic acid, linoleic acid, etc. Is mentioned. Of these, fatty acids having 14 to 20 carbon atoms are preferred.

Examples of the metal constituting the fatty acid metal salt include aluminum, zinc, calcium, magnesium, lithium, sodium, lead, and barium. Of these, aluminum, zinc, and sodium are preferable. Particularly preferred are aluminum distearate (Al (OH) (C ₁₇ H ₃₅ COO) ₂ ) or aluminum monostearate (Al (OH) ₂ (C ₁₇ H ₃₅ COO)), etc. Is preferred. Having an OH group can prevent overcharging and suppress poor transfer. Moreover, it is thought that the processability with inorganic fine powders, such as a silica, improves at the time of a process.

  In addition, the handling property of the toner having a small particle diameter can be improved, and both high image quality and improved transferability can be achieved in development and transfer. In development, the latent image can be reproduced more faithfully. Transfer can be performed without deteriorating the transfer rate of the toner particles during transfer. Further, in tandem transfer, retransfer can be prevented, and occurrence of voids can be suppressed. Furthermore, a high image density can be obtained even if the development amount is reduced. In addition, use in combination with a carrier, which will be described later, can further improve spent resistance, improve handling in the developing device, and increase toner density uniformity. Moreover, development memory generation can be suppressed.

  A configuration in which 1 to 6 parts by weight of an inorganic fine powder having an average particle diameter of 6 nm to 200 nm is externally added to 100 parts by weight of toner base particles is preferable. If the average particle diameter is smaller than 6 nm, silica floating and filming on the photoreceptor are likely to occur. The occurrence of reverse transcription during transcription cannot be suppressed. When it is larger than 200 nm, the fluidity of the toner is deteriorated. When the amount is less than 1.5 parts by weight, the fluidity of the toner is deteriorated. The occurrence of reverse transcription during transcription cannot be suppressed. If the amount is more than 6 parts by weight, silica floating and filming on the photoreceptor are likely to occur. High temperature offset is deteriorated.

  Further, the inorganic fine powder having an average particle diameter of 6 nm to 20 nm is 0.5 to 2.5 parts by weight with respect to 100 parts by weight of the toner base particles, and the inorganic fine powder having an average particle diameter of 20 nm to 200 nm is 100 parts by weight of the toner base particles. On the other hand, a configuration in which 0.5 to 3.5 parts by weight is at least externally added is preferable. By using the silica whose function is separated by this configuration, it is possible to obtain a margin for handling property in development, reverse transfer at the time of transfer, dropout, and scattering. In addition, the spent on the carrier can be prevented. At this time, the ignition loss of the inorganic fine powder having an average particle diameter of 6 nm to 20 nm is preferably 1.5 to 25 wt%, and the ignition loss of the average particle diameter of 20 nm to 200 nm is preferably 0.5 to 23 wt%.

  By specifying the loss on ignition of silica, more margin can be taken against reverse transfer, dropout and scattering during transfer. Further, the use in combination with the carrier and wax described above can improve the spent resistance, improve the handling property in the developing device, and increase the uniformity of the toner density. Moreover, development memory generation can be suppressed.

  If the loss on ignition with an average particle size of 6 nm to 20 nm is less than 1.5 wt%, the transfer margin for reverse transfer and voids becomes narrow. If it exceeds 25 wt%, the surface treatment becomes uneven, resulting in uneven charging. The ignition loss is preferably 1.5 to 20 wt%, more preferably 5 to 19 wt%.

  If the loss on ignition with an average particle diameter of 20 nm to 200 nm is less than 0.5 wt%, the transfer margin for reverse transfer and hollow out becomes narrow. If it exceeds 23 wt%, the surface treatment becomes uneven, resulting in uneven charging. The ignition loss is preferably 1.5 to 18 wt%, more preferably 5 to 16 wt%.

  Further, a positively chargeable inorganic fine powder having an average particle diameter of 6 nm to 200 nm and an ignition loss of 0.5 to 25 wt% is further externally added in an amount of 0.2 to 1.5 parts by weight based on 100 parts by weight of the toner base particles. A configuration for processing is also preferable.

  The effect of adding the positively chargeable inorganic fine powder suppresses the toner from being overcharged during long-term continuous use, and can further extend the developer life. Furthermore, the effect of suppressing scattering during transfer due to overcharging can also be obtained. In addition, the spent on the carrier can be prevented. If the amount is less than 0.2 parts by weight, it is difficult to obtain the effect. If it exceeds 1.5 parts by weight, fogging during development increases. The ignition loss is preferably 1.5 to 20 wt%, more preferably 5 to 19 wt%.

  For drying loss (%), about 1 g of a sample is placed in a container that has been dried, allowed to cool, and precisely weighed in advance, and weighed accurately. Dry in a hot air dryer (105 ° C ± 1 ° C) for 2 hours. After cooling in a desiccator for 30 minutes, the weight is precisely weighed and calculated from the following formula.

Loss on drying (%) = [Loss on drying (g) / Sample amount (g)] × 100
For ignition loss, about 1 g of a sample is placed in a magnetic crucible that has been dried, allowed to cool, and precisely weighed in advance, and weighed accurately. Ignite for 2 hours in an electric furnace set to 500 ° C. After standing to cool in a desiccator for 1 hour, its weight is precisely weighed and calculated from the following formula.

Loss on ignition (%) = [Loss on ignition (g) / Sample amount (g)] × 100
Moreover, it is preferable that the moisture adsorption amount of the processed inorganic fine powder is 1 wt% or less. Preferably it is 0.5 wt% or less, More preferably, it is 0.1 wt% or less, More preferably, it is 0.05 wt% or less. When the content is more than 1 wt%, chargeability is deteriorated and filming on the photoconductor during durability is caused. The water adsorption amount was measured with a continuous vapor adsorption device (BELSORP18: Nippon Bell Co., Ltd.) for the water adsorption device.

  For the determination of the degree of hydrophobicity, 0.2 g of the product to be tested is weighed into 50 ml of distilled water charged in a 250 ml beaker. At the tip, methanol is dropped from a burette invaded in the liquid until the total amount of the inorganic fine powder is wet. At that time, slowly stir slowly with an electromagnetic stirrer. The degree of hydrophobicity is calculated by the following equation from the amount of methanol a (ml) essential for complete wetting.

Hydrophobic degree = (a / (50 + a)) × 100 (%)
(7) Toner powder physical properties In this embodiment, toner base particles containing a binder resin, a colorant and a wax have a volume average particle diameter of 3 to 7 μm and a toner particle diameter of 2.52 to 4 μm in the number distribution. Toner having a mother particle content of 10 to 75% by number, a toner particle size of 25 to 75% by volume in a volume distribution of 4 to 6.06 μm, and a toner particle size of 8 μm or more in a volume distribution Toner containing 5% by volume or less of mother particles and having a particle size of 4 to 6.06 μm in the volume distribution, V46 being the volume percent of the mother particles having a particle size of 4 to 6.06 μm in the number distribution When the number% of the base particles is P46, P46 / V46 is in the range of 0.5 to 1.5, the variation coefficient in the volume average particle size is 10 to 25%, and the variation coefficient in the number particle size distribution is 10 to 10. 28% Is preferred.

  Preferably, the toner base particles have a volume average particle size of 3 to 6.5 μm, the content of toner base particles having a particle size of 2.52 to 4 μm in the number distribution is 20 to 75% by number, and 4 to 6 in the volume distribution. The toner base particles having a particle size of 0.06 μm are 35 to 75% by volume. Further, toner mother particles having a particle size of 8 μm or more in the volume distribution are contained in an amount of 3% by volume or less, and the volume% of toner mother particles having a particle size of 4 to 6.06 μm in the volume distribution is V46. When the number% of toner base particles having a particle diameter of 4 to 6.06 μm in the distribution is P46, P46 / V46 is in the range of 0.5 to 1.3, and the coefficient of variation in the volume average particle diameter is 10 It is preferable that the variation coefficient of the number particle size distribution is 10 to 23%.

  More preferably, the toner base particles have a volume average particle size of 3 to 5 μm, the content of toner base particles having a particle size of 2.52 to 4 μm in the number distribution is 40 to 75% by number, and 4 to 6 in the volume distribution. The toner base particles having a particle size of 0.06 μm are 45 to 75% by volume. Further, toner mother particles having a particle size of 8 μm or more in the volume distribution are contained in an amount of 3% by volume or less, and the volume% of toner mother particles having a particle size of 4 to 6.06 μm in the volume distribution is V46. When the number% of toner base particles having a particle size of 4 to 6.06 μm in the distribution is P46, P46 / V46 is in the range of 0.5 to 0.9, and the coefficient of variation in the volume average particle size is 10 It is preferable that the variation coefficient of the number particle size distribution is 10 to 18%.

  It is possible to prevent high-resolution image quality, and also prevent reverse transfer and dropout in tandem transfer, and achieve both oil-less fixing. The fine powder in the toner affects toner fluidity, image quality, storage stability, filming on the photosensitive member, developing roller, and transfer member, aging characteristics, transferability, particularly multi-layer transfer in the tandem system. Furthermore, it affects the non-offset property, glossiness and translucency in oilless fixing. In a toner containing a wax such as a wax for realizing oil-less fixing, the amount of fine powder affects the compatibility with tandem transferability.

  When the volume average particle size exceeds 7 μm, it is impossible to achieve both image quality and transfer. When the volume average particle size is less than 3 μm, it becomes difficult to handle the toner particles during development.

  If the content of toner base particles having a particle diameter of 2.52 to 4 μm in the number distribution is less than 10% by number, it is impossible to achieve both image quality and transfer. When it exceeds 75% by number, it becomes difficult to handle the toner base particles during development. In addition, filming on the photosensitive member, the developing roller, and the transfer member is likely to occur. Furthermore, fine powder tends to be offset because of its high adhesion to the heat roller. Further, in the tandem system, toner aggregation tends to be strong, and transfer failure of the second color is likely to occur during multilayer transfer. An appropriate range is required.

  If toner base particles having a particle size of 4 to 6.06 μm in the volume distribution exceed 75% by volume, it is impossible to achieve both image quality and transfer. When it is less than 30% by volume, the image quality is deteriorated.

  When toner mother particles having a particle size of 8 μm or more in the volume distribution are contained exceeding 5% by volume, the image quality is deteriorated. Causes transfer failure.

  When the volume% of toner base particles having a particle diameter of 4 to 6.06 μm in the volume distribution is V46, and the number% of toner base particles having a particle diameter of 4 to 6.06 μm in the number distribution is P46, When P46 / V46 is less than 0.5, the amount of fine powder present becomes excessive, resulting in poor fluidity, poor transferability, and poor background fog. When it is larger than 1.5, there are many large particles and the particle size distribution becomes broad, so that high image quality cannot be achieved.

  The purpose of defining P46 / V46 can be used as an index for making toner particles small and narrowing the particle size distribution.

  The coefficient of variation is the standard deviation of the toner particle size divided by the average particle size. This is based on the particle diameter measured using a Coulter counter (Coulter). The standard deviation is expressed as the square root of the value obtained by dividing the square of the difference from the average value of each measured value when (n-1) is measured when n particle systems are measured.

  In other words, the coefficient of variation represents the extent of the particle size distribution, and if the coefficient of variation of the volume particle size distribution is less than 10% or the coefficient of variation of the number particle size distribution is less than 10%, it is difficult to produce, This will increase costs. When the variation coefficient of the volume particle size distribution is larger than 25% or the variation coefficient of the number particle size distribution is larger than 28%, the particle size distribution becomes broad, the toner cohesion becomes stronger, and the filming and transfer to the photosensitive member are performed. It is difficult to collect residual toner in a defective and cleaner-less process.

  The particle size distribution is measured by using a Coulter Counter TA-II type (Coulter Counter Co., Ltd.) and connecting an interface (manufactured by Nikkaki Co., Ltd.) for outputting the number distribution and volume distribution and a personal computer. The electrolyte solution is a surfactant (sodium lauryl sulfate) added to a concentration of 1%. About 2 mg of the toner to be measured is added to about 50 ml. The electrolyte solution in which the sample is suspended is dispersed for about 3 minutes with an ultrasonic disperser. And an aperture of 70 μm was used with a Coulter counter TA-II type. In the 70 μm aperture system, the particle size distribution measurement range is 1.26 μm to 50.8 μm, but the region less than 2.0 μm is not practical because the measurement accuracy and measurement reproducibility are low due to the influence of external noise and the like. Therefore, the measurement area was set to 2.0 μm to 50.8 μm.

Further, the degree of compression is calculated from the static bulk density and the dynamic bulk density, which is one of the indicators of toner fluidity. The fluidity of the toner is affected by the particle size distribution of the toner, the toner particle shape, the external additive, and the type and amount of the wax. When the toner particle size distribution is narrow and the amount of fine powder is small, the toner surface has few irregularities and the shape is nearly spherical, the amount of external additive added is large, or the particle size of the external additive is small, the degree of compression is small. The fluidity of the toner becomes higher. The degree of compression is preferably 5 to 40%. More preferably, it is 10 to 30%. It is possible to achieve both oilless fixing and tandem multi-layer transfer. If it is less than 5%, the fixability is lowered, and the translucency is particularly likely to deteriorate. Toner scattering tends to increase from the developing roller. Transferability greater than 40% is lowered, and tandem-type deficiency occurs and transfer failure occurs.
(8) Carrier For the resin-coated carrier of the present embodiment, a carrier having a coating resin layer made of a fluorine-modified silicone resin containing an aminosilane coupling agent as the carrier core material is preferably used.

  Examples of the carrier core material include an iron powder carrier core material, a ferrite carrier core material, a magnetite carrier core material, and a resin-dispersed carrier core material in which a magnetic material is dispersed in a resin.

  Here, as an example of the ferrite carrier core material, it is generally represented by the following formula.

(MO) _X (Fe ₂ O ₃ ) _Y (where M is selected from Cu, Zn, Fe, Mg, Mn, Ca, Li, Ti, Ni, Sn, Sr, Al, Ba, Co, Mo, etc.) (Contains at least one, and X and Y indicate a molar ratio by weight and satisfy the condition X + Y = 100.)
Ferrite carrier core material is Fe ₂ O ₃ as a main raw material, M is from Cu, Zn, Fe, Mg, Mn, Ca, Li, Ti, Ni, Sn, Sr, Al, Ba, Co, Mo, etc. At least one selected oxide is mixed and used as a raw material.

  As an example of a method for producing a ferrite-based carrier core material, first, an appropriate amount of raw materials such as the above oxides are blended, pulverized, mixed and dried for 10 hours by a wet ball mill, and then held at 950 ° C. for 4 hours. This is pulverized with a wet ball mill for 24 hours, and further added with polyvinyl alcohol, an antifoaming agent, a dispersing agent or the like as a binder to form a slurry having a raw material particle size of 5 μm or less. This slurry is granulated and dried to obtain a granulated product, which is kept at 1300 ° C. for 6 hours while controlling the oxygen concentration, and then pulverized and further classified into a desired particle size distribution.

  As the resin used for the resin coating layer of the present invention, a fluorine-modified silicone resin is essential. The fluorine-modified silicone resin is preferably a crosslinkable fluorine-modified silicone resin obtained from a reaction between a perfluoroalkyl group-containing organosilicon compound and polyorganosiloxane. The compounding ratio of the polyorganosiloxane and the perfluoroalkyl group-containing organosilicon compound is 3 parts by weight or more and 20 parts by weight or less of the perfluoroalkyl group-containing organosilicon compound with respect to 100 parts by weight of the polyorganosiloxane. Is preferred.

  The polyorganosiloxane preferably exhibits at least one repeating unit selected from the following formulas (Chemical Formula 5) and (Chemical Formula 6).

Examples of perfluoroalkyl group-containing organosilicon compounds include CF ₃ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , C ₄ F ₉ CH ₂ CH ₂ Si (CH ₃ ) (OCH ₃ ) ₂ , and C ₈ F _{17. CH 2 CH 2 Si (OCH 3} ) 3, C 8 F 17 CH 2 CH 2 Si (OC 2 H 5) 3, (CF 3) 2 CF (CF 2) 8 CH 2 CH 2 Si (OCH 3) 3 , etc. In particular, those having a trifluoropropyl group are preferred.

  Moreover, in this embodiment, an aminosilane coupling agent is contained in the coating resin layer. As this aminosilane coupling agent, known ones may be used. For example, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, octadecylmethyl [3- (trimethoxy Cyril) propyl] ammonium chloride (from the top SH6020, SZ6023, AY43-021: trade names manufactured by Toray Dow Corning Silicone), KBM602, KBM603, KBE903, KBM573 (trade names manufactured by Shin-Etsu Silicone), etc. Primary amines are preferred. A secondary or tertiary amine substituted with a methyl group, ethyl group, phenyl group or the like is weak in polarity and has little effect on the charge rising characteristics with the toner. When the amino group is an aminomethyl group, aminoethyl group, or aminophenyl group, the most advanced silane coupling agent is a primary amine, but the amino group in a linear organic group extending from the silane. Does not contribute to the charge start-up characteristics with the toner and, conversely, is affected by moisture at high humidity, so it has the charge imparting ability with the initial toner due to the state-of-the-art amino group, but it has the charge imparting ability during printing durability. It will eventually drop and its life will be short.

  Therefore, by using such an aminosilane coupling agent and a fluorine-modified silicone resin in combination, negative chargeability can be imparted to the toner while ensuring a sharp charge amount distribution, and the toner is replenished. The toner has a quick charge rising property and can reduce the toner consumption. Furthermore, the aminosilane coupling agent expresses an effect like a crosslinking agent, improves the degree of crosslinking of the fluorine-modified silicone resin layer as the base resin, further improves the coating resin hardness, Separation and the like can be reduced, the spent resistance is improved, the decrease in charge imparting ability is suppressed, the charge is stabilized, and the durability is improved.

  Further, in the toner configuration described above, the surface of the toner to which a certain amount or more of the low melting point wax is added is substantially resin, so that the chargeability is somewhat unstable. For example, a case where the charging property is weak and the charging start-up property is slow is assumed, and the uniformity of fog and the whole surface of the solid image is deteriorated. By using the carrier in combination, the above problems are improved, the handling property in the developing device is improved, and the uniformity of density on the back side and the near side of the development on the image is improved. In addition, so-called development memory in which a history remains after collecting a solid image can be reduced.

  The use ratio of the aminosilane coupling agent is 5 to 40% by weight, preferably 10 to 30% by weight, based on the resin. If the amount is less than 5% by weight, the effect of the aminosilane coupling agent is not obtained. If the amount exceeds 40% by weight, the degree of crosslinking of the resin coating layer becomes too high, and the charge-up phenomenon is likely to occur. It may cause the occurrence.

Further, in order to prevent charge-up in order to stabilize charging, the resin coating layer can contain conductive fine particles. Conductive fine particles include oil furnace carbon and acetylene black carbon black, semiconductive oxides such as titanium oxide and zinc oxide, powder surfaces such as titanium oxide, zinc oxide, barium sulfate, aluminum borate and potassium titanate. Examples thereof include tin oxide, carbon black, and those coated with metal, and those having a specific resistance of 10 ¹⁰ Ω · cm or less are preferred. The content in the case of using conductive fine particles is preferably 1 to 15% by weight. If the conductive fine particles are contained in a certain amount with respect to the resin coating layer, the filler effect increases the hardness of the resin coating layer by the filler effect. However, if the content exceeds 15% by weight, the formation of the resin coating layer is inhibited. However, it causes a decrease in adhesion and hardness. Further, the excessive content of the conductive fine particles in the full color developer causes the color stain of the toner transferred and fixed on the paper surface.

  The average particle size of the carrier used in the present invention is preferably 20 to 70 μm. When the average particle diameter of the carrier is less than 20 μm, the abundance ratio of the fine particles is increased in the carrier particle distribution, and the carrier particles have a low magnetization per carrier particle, so that the carrier is easily developed on the photoreceptor. On the other hand, when the average particle of the carrier exceeds 70 μm, the specific surface area of the carrier particle becomes small and the toner holding force becomes weak, so that toner scattering occurs. In addition, a full color with many solid portions is not preferable because the reproduction of the solid portions is particularly poor.

  The method for forming the coating layer on the carrier core material is not particularly limited. For example, a known coating method, for example, a dipping method in which powder as a carrier core material is immersed in a solution for forming a coating layer, or for forming a coating layer. Spray method for spraying the solution onto the surface of the carrier core material, Fluidized bed method for spraying the solution for forming the coating layer in a state where the carrier core material is suspended by the fluidized air, Solution for forming the carrier core material and the coating layer in a kneader coater In addition to wet coating methods such as the kneader coater method that removes the solvent, the powdered resin and the carrier core material are mixed at high speed, and the frictional heat is used to melt the resin powder onto the surface of the carrier core material. Any of these can be applied, and in the coating of a fluorine-modified silicone resin containing an aminosilane coupling agent in the present invention, wet coating is possible. The law is particularly preferably used.

  The solvent used in the coating layer forming coating solution is not particularly limited as long as it dissolves the coating resin, and can be selected so as to be compatible with the coating resin used. In general, for example, aromatic hydrocarbons such as toluene and xylene, ketones such as acetone and methyl ethyl ketone, and ethers such as tetrahydrofuran and dioxane can be used.

  The amount of the resin coating is preferably 0.2 to 6.0% by weight, more preferably 0.5 to 5.0% by weight, still more preferably 0.6 to 4.0% by weight, based on the carrier core material. 7 to 3% by weight. When the coating amount of the resin is less than 0.2% by weight, a uniform coating cannot be formed on the surface of the carrier, and it is greatly affected by the characteristics of the carrier core material, and the fluorine-modified silicone resin of the present invention The effect of the aminosilane coupling agent cannot be exhibited sufficiently. If it exceeds 6.0% by weight, the coating layer becomes too thick, and granulation of carrier particles occurs, and uniform carrier particles tend not to be obtained.

  Thus, after coating the fluorine-modified silicone resin containing an aminosilane coupling agent on the surface of the carrier core material, it is preferable to perform a baking treatment. The means for performing the baking process is not particularly limited, and may be either an external heating system or an internal heating system, for example, a fixed or fluid electric furnace, a rotary kiln electric furnace, or a burner furnace. Or it may be baked by microwave. However, with regard to the temperature of the baking treatment, in order to efficiently express the effect of the fluorine silicone that improves the spent resistance of the resin coating layer, the treatment is preferably performed at a high temperature of 200 to 350 ° C., more preferably 220-280 ° C. The treatment time is preferably 1.5 to 2.5 hours. When the treatment temperature is low, the hardness of the coating resin itself is lowered. If the processing temperature is too high, charge reduction occurs.

(9) Two-component development In the development process, an AC bias is applied between the photosensitive member and the developing roller together with a DC bias. The frequency at that time is 1 to 10 kHz, the AC bias is 1.0 to 2.5 kV (pp), and the peripheral speed ratio between the photoconductor and the developing roller is 1: 1.2 to 1: 2. It is preferable. More preferably, the frequency is 3.5 to 8 kHz, the AC bias is 1.2 to 2.0 kV (pp), and the peripheral speed ratio between the photosensitive member and the developing roller is 1: 1.5 to 1: 1. .8. More preferably, the frequency is 5.5 to 7 kHz, the AC bias is 1.5 to 2.0 kV (pp), and the peripheral speed ratio between the photosensitive member and the developing roller is 1: 1.6 to 1: 1. .8.

  With this development process configuration and the use of the toner or the two-component developer of the present embodiment, dots can be faithfully reproduced, and the original density and the density of the output image are proportional (also referred to as a characteristic that repels the development γ characteristic). it can. Both high-quality images and oilless fixability can be achieved. Further, even a high-resistance carrier can prevent charge-up under low humidity, and a high image density can be obtained even in continuous use.

  Even if the toner surface is almost resin-based, the combined use of this carrier composition and AC bias can reduce adhesion to the carrier, maintain image density, reduce fog, and reproduce dots faithfully. Seem.

  If the frequency is smaller than 1 kHz, dot reproducibility is deteriorated and halftone reproducibility is deteriorated. When the frequency is higher than 10 kHz, the development region cannot be followed and the effect does not appear. In this frequency range, in the two-component development using a high resistance carrier, it works to reciprocate between the carrier and the toner rather than between the developing roller and the photosensitive member, and has the effect of slightly releasing the toner from the carrier. Good reproducibility and halftone reproducibility are achieved, and a high image density can be obtained.

  When the AC bias is smaller than 1.0 kV (pp), the effect of suppressing charge-up cannot be obtained, and when the AC bias is larger than 2.5 kV (pp), the fog increases. If the peripheral speed ratio between the photoconductor and the developing roller is smaller than 1: 1.2 (the developing roller becomes slow), it is difficult to obtain image density. When the peripheral speed ratio between the photosensitive member and the developing roller is larger than 1: 2 (the developing roller speed is increased), toner scattering increases.

(10) Tandem color process In order to form a color image at high speed, this embodiment has a plurality of toner image forming stations including a photoconductor, a charging means, and a toner carrier, and a static image formed on the image carrier. A primary transfer process in which a toner image obtained by developing an electrostatic latent image is transferred to the transfer member by bringing an endless transfer member into contact with the image carrier is sequentially executed, and a multilayer image is formed on the transfer member. A transfer process configured to execute a secondary transfer process in which a multi-layer toner image formed on the transfer body is then collectively transferred to a transfer medium such as paper or OHP. When the distance from the first primary transfer position to the second primary transfer position is d1 (mm) and the peripheral speed of the photosensitive member is v (mm / s), the transfer position satisfies d1 / v ≦ 0.65. In the configuration that takes the configuration, This is intended to achieve both downsizing of the printer and printing speed. In order to realize a reduction in size that can process 20 sheets per minute (A4) or more and the machine can be used for SOHO, it is essential to have a configuration in which a plurality of toner image forming stations are short and the process speed is increased. is there. In order to achieve both a reduction in size and a printing speed, a configuration in which the above value is 0.65 or less is considered a minimum.

  However, when the configuration between the toner image forming stations is short, for example, the time from the primary transfer of the yellow toner of the first color to the primary transfer of the next magenta toner of the second color is extremely short. There is almost no charge relaxation or charge relaxation of the transferred toner, and when transferring the magenta toner onto the yellow toner, the magenta toner is repelled by the charge action of the yellow toner, the transfer efficiency decreases, The problem of hollowing out occurs. Further, during the primary transfer of the cyan toner of the third color, the cyan toner scatters, transfer failure, and transfer loss occur remarkably when transferred onto the previous yellow and magenta toners. Furthermore, during repeated use, toner of a specific particle size is selectively developed, and if the fluidity of each toner particle differs greatly, the chance of frictional charging differs, resulting in variation in charge amount and further deterioration in transferability. Will be invited.

  Therefore, by using the toner or the two-component developer of the present embodiment, the charge distribution is stabilized, the toner can be prevented from being overcharged, and the fluidity fluctuation can be suppressed. For this reason, it is possible to prevent transfer efficiency from being lowered, character dropout during transfer, and reverse transfer without sacrificing fixing characteristics.

(11) Cleanerless process In this embodiment, a cleanerless process that performs the following charging, exposure, and development processes without using a cleaning process that collects toner remaining on the photoreceptor after cleaning by cleaning is basically used. It is also suitably used for the electrophotographic apparatus having the configuration.

  By using the toner or the two-component developer of the present embodiment, toner aggregation is suppressed, overcharging is prevented, charging property is stabilized, and high transfer efficiency can be obtained. Further, the improvement in uniform dispersibility in the resin, good chargeability, and the releasability of the material make it possible to recover the toner remaining in the non-image area during development. For this reason, there is no development memory in which the image pattern in front of the non-image portion remains.

(12) Oilless Color Fixation In this embodiment, the present invention is suitably used for an electrophotographic apparatus having a fixing process having an oilless fixing configuration in which oil is not used as a toner fixing unit. As the heating means, electromagnetic induction heating is a preferable configuration from the viewpoint of shortening the warm-up time and saving energy. A heating and pressurizing unit having at least a magnetic field generating unit, a rotary heating member having at least a heat generation layer and a release layer generated by electromagnetic induction, and a rotary pressurizing member forming a fixed nip with the rotary heating member; In this configuration, a transfer medium such as copy paper on which toner is transferred is passed between the rotary heating member and the rotary pressure member, and is fixed. As a feature thereof, the warm-up time of the rotary heating member is very fast compared to the case where a conventional halogen lamp is used. For this reason, since the copying operation is started in a state where the temperature of the rotary pressure member is not sufficiently raised, low temperature fixing and a wide range of offset resistance are required.

  As a configuration, a configuration using a fixing belt in which a heating member and a fixing member are separated is also preferably used. As the belt, a heat resistant belt such as a nickel electroformed belt or a polyimide belt having heat resistance and deformability is preferably used. In order to improve releasability, it is preferable to use silicone rubber, fluororubber, or fluororesin as the surface layer.

  In such fixing, conventionally, release oil has been applied to prevent offset. It is no longer necessary to apply release oil with toner having releasability without using oil. However, if the release oil is not applied, it is easy to be charged, and if an unfixed toner image comes close to the heating member or the fixing member, toner jump may occur due to the influence of charging. It tends to occur especially at low temperatures and low humidity.

  Therefore, by using the toner of this embodiment, low temperature fixing and a wide range of offset resistance can be realized without using oil, and high color translucency can be obtained. Further, the toner can be prevented from being overcharged, and toner flying due to the charging action with the heating member or the fixing member can be suppressed.

(Carrier production example 1)
39.7Mol% in terms of MnO, 9.9 mol% in terms of MgO, in 0.8 mol% wet ball mill 49.6Mol% and SrO terms in terms of Fe ₂ O _3, and ground for 10 hours, mixed, dried , Kept at 950 ° C. for 4 hours, and pre-baked. This was pulverized with a wet ball mill for 24 hours, then granulated with a spray dryer, dried, and held in an electric furnace at 1270 ° C. for 6 hours in an atmosphere with an oxygen concentration of 2%, followed by firing. Then, it was crushed and further classified to obtain a ferrite particle core material having an average particle diameter of 50 μm and a saturation magnetization of 65 emu / g when the applied magnetic field was 3000 oersted.

Next, R ₁ and R ₂ represented by (Chemical Formula 7) are methyl groups, that is, (CH ₃ ) ₂ SiO _2/2 unit is 15.4 mol%, and R ₃ represented by (Chemical Formula 8) is a methyl group, that is, A fluorine-modified silicone resin was obtained by reacting 250 g of polyorganosiloxane having 84.6 mol% of CH ₃ SiO _3/2 units with 21 g of CF ₃ CH ₂ CH ₂ Si (OCH ₃ ) ₃ . Further, 100 g of the fluorine-modified silicone resin in terms of solid content and 10 g of aminosilane coupling agent (γ-aminopropyltriethoxysilane) were weighed and dissolved in 300 cc of toluene solvent.

  Coating was performed on 10 kg of the ferrite particles by stirring the coating resin solution for 20 minutes using an immersion drying type coating apparatus. Thereafter, baking was performed at 260 ° C. for 1 hour to obtain carrier A1.

(Carrier production example 2)
The core material is manufactured and coated in the same process as in Production Example 1, except that CF ₃ CH ₂ CH ₂ Si (OCH ₃ ) _{3 is changed} to C ₈ F ₁₇ CH ₂ CH ₂ Si (OCH ₃ ) ₃ Carrier A2 was obtained.

(Carrier production example 3)
The core material is manufactured and coated in the same process as in Production Example 1 except that conductive carbon (EC made by Ketjen Black International Co., Ltd.) is dispersed in a pearl mill in an amount of 5 wt% based on the resin solid content. A3 was obtained.

(Carrier Production Example 4)
Except having changed the addition amount of the aminosilane coupling agent into 30g, the core material was manufactured in the process similar to the manufacture example 3, it coated, and carrier A4 was obtained.

(Carrier Production Example 5)
A core material was produced in the same process as in Production Example 3 except that the amount of the aminosilane coupling agent added was changed to 50 g, and coating was performed to obtain a carrier b1.

(Carrier Production Example 6)
100 g of straight silicone (SR-2411 manufactured by Toray Dow Corning Co., Ltd.) as a solid content was weighed as a coating resin and dissolved in 300 cc of a toluene solvent. Coating was performed on 10 kg of the ferrite particles by stirring the coating resin solution for 20 minutes using an immersion drying type coating apparatus. Thereafter, baking was performed at 210 ° C. for 1 hour to obtain a carrier b2.

(Carrier Production Example 7)
As a coating resin, 100 g of perfluorooctylethyl acrylate / methacrylate copolymer in terms of solid content was weighed and dissolved in 300 cc of toluene solvent. Coating was performed on 10 kg of the ferrite particles by stirring the coating resin solution for 20 minutes using an immersion drying type coating apparatus. Thereafter, baking was performed at 200 ° C. for 1 hour to obtain a carrier b3.

(Carrier Production Example 8)
100 g of an acrylic modified silicone resin (KR-9706, manufactured by Shin-Etsu Chemical Co., Ltd.) as a solid content was weighed and dissolved in a 300 cc toluene solvent. Coating was performed on 10 kg of the ferrite particles by stirring the coating resin solution for 20 minutes using an immersion drying type coating apparatus. Thereafter, baking was performed at 210 ° C. for 1 hour to obtain carrier b4.

  Next, examples of the toner of the present invention will be described, but the present invention is not limited to these examples.

[Toner manufacturing process]
The manufacturing process of one Example of this invention is shown using FIG. Reference numeral 20 denotes an emulsion polymerization tank, which carries out emulsion polymerization by supplying a monomer, an anionic surfactant (emulsifier), a polymerization initiator, ion-exchanged water and the like from a raw material supply line 21. The resulting polymer is a resin particle dispersion having an average particle size of 0.1 to 0.2 μm. Reference numeral 30 denotes a pigment dispersion tank, which supplies pigment, an anionic surfactant, and ion-exchanged water from a raw material supply line 31 to obtain pigment dispersed particles having an average particle size of 0.1 to 0.2 μm. Reference numeral 40 denotes the wax dispersion tank described in FIGS. 3 to 4, and wax dispersion particles having an average particle diameter of 0.2 to 0.5 μm are supplied from the raw material supply line 44 by supplying wax, an anionic surfactant, and ion-exchanged water. Get. Reference numeral 90 denotes a dispersion tank of charge control resin particles, and second resin particles containing an acrylic sulfonic acid copolymer having a sulfonic acid polar group having an average particle diameter of 0.1 to 1 μm from the supply line 91. A dispersion (charge control resin particles) is supplied.

  When each primary particle was obtained, valves 22, 32, 49, and 92 were opened, and each primary material was sent from each supply line 51, 52, 53, and 93 to agglomeration tank 50 to prepare a mixed particle dispersion.

  Thereafter, NaOH and an aqueous magnesium sulfate solution were added to the obtained mixed dispersion at a predetermined mixing ratio, and heated to obtain aggregated particles in which the resin was melted. The operation process in the aggregation tank 50 is shown in FIGS.

  Next, the valve 54 is opened and sent from the supply line 61 to the filtration separation tank 60 to separate the aggregated particles. Next, the valve 62 is opened and the aggregated particles are sent from the supply line 71 to the washing tank 70 to perform water cleaning, and the valve 72 is opened and sent from the supply line 73 to the filtration separation tank 60 to separate the aggregated particles from water. . Repeat this operation multiple times. Thereafter, the valve 63 is opened to obtain a purified toner of aggregated particles. This is dried to obtain a toner product.

  In the above, the filter of the filtration separation tank 60 is a funnel glass filter No. 5A (7 μm) was used.

  FIG. 8 shows an operation process in the aggregation tank 50.

  First, in FIG. 8A, a first resin particle dispersion in which first resin particles are dispersed, and charge control resin particles containing an acrylic sulfonic acid copolymer having a sulfonic acid polar group are dispersed. A mixed dispersion having a pH of 6.0 or less is prepared by mixing the second resin particle dispersion, the colorant particle dispersion in which the colorant particles are dispersed, and the wax particle dispersion in which the wax particles are dispersed. This is because, during the emulsion polymerization of the resin in the previous step, a aging treatment is further performed at 90 ° C. for about 3 hours after the polymerization, and the used polymerization initiator is retained on the acidic side and disappears.

Next, in pH adjustment step 1, an alkali such as NaOH is added to maintain the pH at 9.5 to 12.2. This is to efficiently perform aggregation in the next aggregation process. In the aggregation treatment step, for example, a flocculant such as MgSO ₄ is added for aggregation treatment.

  Next, in the heat treatment step, heat fusion treatment is performed. At this time, the pH at the end of the treatment is maintained at 7.0 to 9.5, and toner particles that are aggregated particles having a sharp molecular weight distribution are obtained.

  In FIG. 8B, the first resin particle dispersion in which the first resin particles are dispersed, and the charge control resin particles containing the acrylic sulfonic acid copolymer having a sulfonic acid polar group are dispersed. A mixed dispersion having a pH of 6.0 or less is prepared by mixing the second resin particle dispersion, the colorant particle dispersion in which the colorant particles are dispersed, and the wax particle dispersion in which the wax particles are dispersed. This is because, during the emulsion polymerization of the resin in the previous step, a aging treatment is further performed at 90 ° C. for about 3 hours after the polymerization, and the used polymerization initiator is retained on the acidic side and disappears.

Next, in pH adjustment step 1, an alkali such as NaOH is added to maintain the pH at 9.5 to 12.2. This is to efficiently perform aggregation in the next aggregation process. In the aggregation treatment step, for example, a flocculant such as MgSO ₄ is added for aggregation treatment.

  Next, in the heat treatment step, heat fusion treatment is performed. At this time, the pH at the end of the treatment is maintained at 7.0 to 9.5, and aggregated particles having a sharp molecular weight distribution are obtained.

  Further, a second resin particle dispersion containing an acrylic sulfonic acid copolymer having a sulfonic acid polar group is added and mixed, and in the pH adjustment step, the pH is adjusted to 5.2 to 8.8. The heat treatment step is performed, and in the pH adjustment step, the pH is adjusted to 3.2 to 6.8. Then, heat treatment is performed in the heat treatment step to form toner particles in which a second resin containing an acrylic sulfonic acid copolymer having a sulfonic acid polar group is fused.

[Creation of resin dispersion]
Table 1 shows the characteristics of the resin used. Mn is a number average molecular weight, Mw is a weight average molecular weight, Mz is a Z average molecular weight, Mp is a molecular weight peak value, Tm (° C.) is a softening point, and Tg (° C.) is a glass transition point. Styrene, n-butyl acrylate, and acrylic acid indicate the amount (g).

(1) Preparation of resin particle dispersion RL1 A monomer liquid consisting of 96 g of styrene, 24 g of n-butyl acrylate, and 3.6 g of acrylic acid was added to an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd.) in 200 g of ion-exchanged water. (Product: Neogen RK) 3 g, dodecanethiol 6 g, carbon tetrabromide 1.2 g was dispersed, potassium persulfate 1.2 g was added thereto, and emulsion polymerization was performed at 70 ° C. for 6 hours. Thereafter, aging treatment is further performed at 90 ° C. for 3 hours, and resin particles having Mn of 3900, Mw of 10900, Mz of 37800, Mp of 8100, Tm of 115 ° C., Tg of 43 ° C., and median diameter of 0.12 μm are dispersed. A first resin particle dispersion RL1 was prepared.

(2) Preparation of resin particle dispersion RL2 A monomer liquid consisting of 204 g of styrene, 36 g of n-butyl acrylate, and 3.6 g of acrylic acid was added to an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd.) in 400 g of ion-exchanged water. (Product: Neogen RK) 6 g, dodecanethiol 6 g, carbon tetrabromide 1.2 g was dispersed, potassium persulfate 1.2 g was added thereto, and emulsion polymerization was performed at 70 ° C. for 5 hours. Thereafter, aging treatment is further performed at 90 ° C. for 5 hours, and resin particles having Mn of 6600, Mw of 60300, Mz of 259000, Mp of 8100, Tm of 128 ° C., Tg of 55 ° C., and median diameter of 0.18 μm are dispersed. A first resin particle dispersion RL2 was prepared.

(3) Preparation of resin particle dispersion RL3 A monomer liquid consisting of 204 g of styrene, 36 g of n-butyl acrylate, and 3.6 g of acrylic acid was added to an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd.) in 400 g of ion-exchanged water. (Product: Neogen RK) 6 g, dodecanethiol 12 g, and carbon tetrabromide 2.4 g were dispersed, and potassium persulfate 1.2 g was added thereto, followed by emulsion polymerization at 70 ° C. for 5 hours. Thereafter, aging treatment is further performed at 90 ° C. for 2 hours, and resin particles having Mn of 2600, Mw of 18300, Mz of 96200, Mp of 2700, Tm of 109 ° C., Tg of 45 ° C., and median diameter of 0.18 μm are dispersed. A first resin particle dispersion RL3 was prepared.

(4) Preparation of resin particle dispersion RH4 A monomer liquid consisting of 102 g of styrene, 18 g of n-butyl acrylate, and 1.8 g of acrylic acid was added to an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd.) in 200 g of ion-exchanged water. Manufactured by: Neogen RK) 3 g, dodecanethiol 0 g, carbon tetrabromide 0 g, and potassium persulfate 1.2 g is added thereto, followed by emulsion polymerization at 70 ° C. for 5 hours. Mn is 43300, Mw is A third resin particle dispersion RH4 was prepared in which resin particles of 262000, Mz of 577000, Mp of 182000, Tm of 197 ° C., Tg of 77 ° C., and median diameter of 0.12 μm were dispersed.

(5) Preparation of Resin Particle Dispersion RD5 A monomer liquid comprising 102 g of styrene, 23.5 g of (Chemical Formula 9), and 31 g of (Chemical Formula 10) was added to 250 g of ion-exchanged water with an anionic surfactant (first Kogyo Seiyaku Co., Ltd .: Neogen RK) 3 g, dodecanethiol 6 g, carbon tetrabromide 1.2 g were dispersed, and a polymerization initiator 2,2′-azobis (2-methylbutyronitrile) 1. 6 g of the diluted solution was added dropwise over 1 hour and heated to 70 ° C. with stirring. Stirring was continued for 5 hours to complete the polymerization. A second resin particle dispersion RD5 in which resin particles with a median diameter of 0.17 μm were dispersed was prepared.

(6) Preparation of resin particle dispersion RD6 A monomer liquid consisting of 102 g of styrene, 22 g of (Chemical 9) and 22 g of (Chemical 10) was added to 230 g of ion-exchanged water with an anionic surfactant (Daiichi Kogyo Seiyaku). Co., Ltd .: Neogen RK) 3 g, dodecanethiol 6 g, carbon tetrabromide 1.2 g were dispersed, and polymerization initiator 2,2′-azobis (2-methylbutyronitrile) 1.6 g The diluted solution was added dropwise over 1 hour and heated to 70 ° C. with stirring. Stirring was continued for 5 hours to complete the polymerization. A second resin particle dispersion RD6 in which resin particles having a median diameter of 0.18 μm were dispersed was prepared.

(7) Preparation of Resin Particle Dispersion RD7 A monomer liquid consisting of 102 g of styrene, 20.4 g of (Chemical Formula 9), and 13.6 g of (Chemical Formula 10) was added to 220 g of ion-exchanged water with an anionic surfactant ( Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK) 3 g, dodecanethiol 6 g, carbon tetrabromide 1.2 g was dispersed, and this was a polymerization initiator 2,2′-azobis (2-methylbutyronitrile). 1.6 g of the diluted solution was added dropwise over 1 hour and heated to 70 ° C. with stirring. Stirring was continued for 5 hours to complete the polymerization. A second resin particle dispersion RD7 in which resin particles having a median diameter of 0.20 μm were dispersed was prepared.

(8) Preparation of Resin Particle Dispersion RH8 A monomer liquid consisting of 102 g of styrene obtained by melting 4 g of an aluminum salicylate metal complex (Orient Chemical Co., Ltd .: E88), 18 g of n-butyl acrylate, and 1.8 g of acrylic acid was ionized. In 200 g of exchange water, 3 g of an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK) was dispersed using 0 g of dodecanethiol and 0 g of carbon tetrabromide, and 1.2 g of potassium persulfate was added thereto. Emulsion polymerization was performed at 70 ° C. for 5 hours, and resin particles having Mn of 41000, Mw of 242000, Mz of 575000, Mp of 154000, Tm of 193 ° C., Tg of 76 ° C., and median diameter of 0.22 μm were dispersed. A third resin particle dispersion RH8 was prepared.

(Example 1)
Creating a pigment dispersion
Table 2 shows the pigments used.

(1) Preparation of Colorant Particle Dispersion Liquid PM1 20 g of magenta pigment (KETRED 309 manufactured by Dainippon Ink & Co.), 2 g of anionic surfactant (Neogen R manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), and 78 g of ion-exchanged water are mixed and ultrasonically mixed. Using a disperser, dispersion was performed at an oscillation frequency of 30 kHz for 20 minutes to prepare a colorant particle dispersion liquid PM1 in which colorant particles having a median diameter of 0.12 μm were dispersed.

(2) Preparation of Colorant Particle Dispersion PC1 20 g of cyan pigment (KETBLUE111 manufactured by Dainippon Ink & Co., Ltd.), 2 g of anionic surfactant (Neogen R manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and 78 g of ion-exchanged water are mixed and ultrasonicated. Dispersion was performed for 20 minutes at an oscillation frequency of 30 kHz using a disperser to prepare a colorant particle dispersion PC1 in which colorant particles having a median diameter of 0.12 μm were dispersed.

(3) Preparation of colorant particle dispersion PY1 20 g of yellow pigment (PY74 manufactured by Sanyo Dye), 2 g of anionic surfactant (Neogen R manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), and 78 g of ion-exchanged water are mixed and ultrasonically dispersed. A colorant particle dispersion PY1 in which colorant particles having a median diameter of 0.12 μm were dispersed was prepared by using a machine for 20 minutes at an oscillation frequency of 30 kHz.

(4) Preparation of colorant particle dispersion PB1 20 g of black pigment (MA100S manufactured by Mitsubishi Chemical Co., Ltd.), 2 g of anionic surfactant (Neogen R manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and 78 g of ion-exchanged water are mixed and ultrasonically dispersed. Dispersion was performed for 20 minutes at an oscillation frequency of 30 kHz using a machine to prepare a colorant particle dispersion PB1 in which colorant particles having a median diameter of 0.12 μm were dispersed.

(Example 2)
A wax dispersion was made. The properties of the waxes used are shown in (Table 3), (Table 4), (Table 5), and (Table 6).

(1) Preparation of Wax Particle Dispersion WA1 FIG. 3 is a schematic view of a stirring and dispersing apparatus, and FIG. 4 is a view seen from above. Reference numeral 41 denotes an outer tub, in which cooling water is injected from 47 and discharged from 48. Reference numeral 42 denotes a dam plate that stops the liquid to be treated, and a hole is formed in the center portion. Reference numeral 43 denotes a rotating body that rotates at a high speed and is fixed to the shaft 46 so that it can rotate at a high speed. A hole of about 1 to 5 mm is formed on the side surface of the rotating body, and the liquid to be processed can be moved. The tank is 120 ml, and about half of the liquid to be treated is charged. The speed of the rotating body was rotated at a maximum of 50 m / s. The diameter of the rotating body is 52 mm, and the inner diameter of the tank is 56 mm. Reference numeral 804 denotes a raw material inlet for continuous processing. Sealed when batch-type.

  70 g of ion exchange water, 1 g of an anionic surfactant (SCF manufactured by Sanyo Kasei Kogyo Co., Ltd.), 1 g of nonionic surfactant (New Coal 565C manufactured by Nippon Emulsifier Co., Ltd.), and 28 g of wax (W-1) were charged, and the speed of the rotating body Was 20 min / s for 5 min, and then the rotational speed was increased to 50 m / s and treated for 5 min. The liquid temperature in the tank rose to 92 ° C. The heat melted the wax, and a fine wax particle dispersion WA1 was formed by a strong shearing force.

(2) Preparation of wax particle dispersion WA2
Under the same conditions as in (1), 70 g of ion-exchanged water, 1 g of an anionic surfactant (SCF manufactured by Sanyo Kasei Kogyo Co., Ltd.), 1 g of nonionic surfactant (New Coal 565C manufactured by Nippon Emulsifier Co., Ltd.), wax (W-2) 28 g was charged, and the speed of the rotating body was 3 minutes at 20 m / s, and then the rotational speed was increased to 45 m / s for 5 minutes to form a wax particle dispersion WA2.

(3) Preparation of wax particle dispersion WA3
Under the same conditions as in (1), 70 g of ion-exchanged water, 1 g of an anionic surfactant (SCF manufactured by Sanyo Kasei Kogyo Co., Ltd.), 1 g of nonionic surfactant (New Coal 565C manufactured by Nippon Emulsifier Co., Ltd.), wax (W-2) 28 g was charged, and the speed of the rotating body was 20 m / s for 3 minutes, and then the rotational speed was increased to 50 m / s for 4 minutes to form a wax particle dispersion WA3.

(4) Preparation of Wax Particle Dispersion WA4 FIG. 5 is a schematic view of a stirring and dispersing apparatus, and FIG. 6 is a view seen from above. 80 is a raw material inlet, 82 is a fixed body and has a floating structure. A narrow gap of about 1 μm to 10 μm is formed by the pressing force of the spring 81 and the pushing force of the rotating body 83 and the high speed rotating force. A shaft 84 is connected to a motor (not shown). The raw material charged from 80 receives a strong shearing force between the gap between the stationary body and the rotating body, and is dispersed into fine particles in the liquid. The processed raw material liquid is discharged from 86. FIG. 6 shows a view from above. The discharged raw material liquid 85 is radiated and collected in a sealed container. The outer diameter of the rotating body is 100 mm.

  The raw material liquid is pre-dispersed with a wax and a surfactant in a preheated aqueous medium, which is introduced from the inlet 80 and is instantly refined. The supply amount was 1 kg / h, and the rotating body was rotated at a maximum speed of 100 m / s.

  70 g of ion-exchanged water, 1 g of an anionic surfactant (SCF manufactured by Sanyo Kasei Kogyo Co., Ltd.), 1 g of a nonionic surfactant (New Coal 565C manufactured by Nippon Emulsifier Co., Ltd.), and 28 g of wax (W-3) were charged, and the speed of the rotating body Was processed at 100 m / s and the supply rate was 1 kg / h to form a wax particle dispersion WA4.

(5) Preparation of wax particle dispersion WA5
Under the same conditions as in (1), 70 g of ion-exchanged water, 1 g of an anionic surfactant (SCF manufactured by Sanyo Chemical Industries, Ltd.), 1 g of a nonionic surfactant (New Coal 565C manufactured by Nippon Emulsifier Co., Ltd.), wax (W-4) 28 g was charged, and the speed of the rotating body was 3 minutes at 20 m / s, and then the rotational speed was increased to 40 m / s for 4 minutes to form a wax particle dispersion WA5.

(6) Preparation of wax particle dispersion WA6
Under the same conditions as in (4), the speed of the rotating body was rotated at 90 m / s, 70 g of ion-exchanged water, 1 g of an anionic surfactant (SCF manufactured by Sanyo Kasei Kogyo Co., Ltd.), nonionic surfactant (manufactured by Nippon Emulsifier Co., Ltd.) 1 g of New Coal 565C) and 28 g of wax (W-1) were charged to form a wax particle dispersion WA6.

(7) Preparation of wax particle dispersion WA7
Under the same conditions as in (1), 70 g of ion-exchanged water, 1 g of an anionic surfactant (SCF manufactured by Sanyo Chemical Industries, Ltd.), 1 g of a nonionic surfactant (New Coal 565C manufactured by Nippon Emulsifier Co., Ltd.), wax (W-4) 28 g was charged, the speed of the rotating body was 3 minutes at 20 m / s, and then the rotational speed was increased to 40 m / s, followed by treatment for 4 minutes to form a wax particle dispersion WA7.

(8) Preparation of Wax Particle Dispersion Wa8 70 g of ion-exchanged water, 1 g of an anionic surfactant (SCF manufactured by Sanyo Kasei Kogyo Co., Ltd.), 1 g of a nonionic surfactant (New Coal 565C manufactured by Nippon Emulsifier Co., Ltd.), paraffin wax (Nippon Seiki) A wax particle dispersion wa8 was formed under the same conditions as in (1), with a rotating body speed of 20 m / s and 5 min treatment.

(9) Preparation of wax particle dispersion wa9 70 g of ion exchange water, 1 g of an anionic surfactant (SCF manufactured by Sanyo Chemical Industries, Ltd.), 1 g of a nonionic surfactant (New Coal 565C manufactured by Nippon Emulsifier Co., Ltd.) FT0070 (manufactured by Nippon Seiki Co., Ltd., melting point: 72 ° C.) (28 g) was charged, and under the same conditions as in (1), the speed of the rotating body was 25 m / s and the treatment was performed for 5 minutes to form a wax particle dispersion wa9.

(10) Preparation of Wax Particle Dispersion Wa10 70 g of ion-exchanged water, 1 g of an anionic surfactant (SCF manufactured by Sanyo Kasei Kogyo Co., Ltd.), 1 g of a nonionic surfactant (New Coal 565C manufactured by Nippon Emulsifier Co., Ltd.), a hydrocarbon wax ( 28 g of LUVAX 2191 manufactured by Nippon Seisaku Co., Ltd., melting point 83 ° C.) was charged and treated with a homogenizer for 30 min to form a wax particle dispersion wa10.

Example 3
Preparation of toner base The composition of the toner produced as a trial toner is shown in Table 7.

(1) Preparation of toner base M1 In a four-necked flask having 2000 ml of a thermometer and a cooling tube, 204 g of the first resin particle dispersion RL2, 20 g of the second resin particle dispersion RD6, and colorant particle dispersion PM1 20 g, wax particle dispersion WA1 50 g, and ion-exchanged water 200 ml were added, and mixed for 10 min using a homogenizer (manufactured by IKA: Ultra Tarrax T50) to prepare a mixed particle dispersion. The pH of the obtained mixed dispersion was 3.3.

Thereafter, 1N NaOH was added to the obtained mixed dispersion to adjust the pH to 12.0, and then 200 g of a 30% strength magnesium sulfate aqueous solution was added and stirred for 10 minutes. Thereafter, the temperature was raised from 22 ° C. to 70 ° C. at a rate of 5 ° C./min, and then heated at 70 ° C. for 2 hours. Thereafter, the temperature was raised to 85 ° C. and treated for 5 hours to obtain aggregated particles. The obtained aggregated particle dispersion had a pH of 9.4.
Then, after cooling, the reaction product (toner base material) was filtered and washed with ion-exchanged water three times. The toner base thus obtained was dried at 40 ° C. for 6 hours with a fluid dryer to obtain toner base M1. When observed with a Coulter counter (manufactured by Coulter Inc .: Multisizer 2), the volume average particle diameter was 3.9 μm and the coefficient of variation was 20.1.

  At this time, when the pH at the time of preparing the mixed dispersion becomes higher than 6.0, when the colored resin particles are formed by heating, the pH fluctuation (decrease phenomenon) in the liquid becomes large and the particles become coarse. End up. When adjusting the pH of the mixed dispersion before addition of the water-soluble inorganic salt and before heating, if it is less than 9.5, the formed colored resin particles become coarse. When the pH was 9.1, the volume average particle diameter was 9.2 μm, and the coefficient of variation was 29.5, which was coarse. When the pH was 12.5, the amount of free wax increased, making it difficult to encapsulate the wax uniformly. When the pH of the liquid when the aggregated particles are formed is greater than 9.5, aggregation is poor and free wax increases.

(2) Preparation of toner base M2 In a 4-ml flask having a thermometer and a cooling tube, 2000 ml, 204 g of the first resin particle dispersion RL2, 10 g of the second resin particle dispersion RD7, and colorant particle dispersion PM1 20 g, wax particle dispersion WA3 30 g, and ion-exchanged water 200 ml were added and mixed for 10 min using a homogenizer (IKA: Ultra Turrax T50) to prepare a mixed particle dispersion. The pH of the obtained mixed dispersion was 0.9.

  Thereafter, 1N NaOH was added to the obtained mixed dispersion to adjust the pH to 9.9, and then 200 g of a 30% strength magnesium sulfate aqueous solution was added and stirred for 10 minutes. Thereafter, the temperature was raised from 22 ° C. to 70 ° C. at a rate of 5 ° C./min, and then heated at 70 ° C. for 2 hours. Thereafter, the temperature was raised to 85 ° C. and treated for 5 hours to obtain aggregated particles. The obtained aggregated particle dispersion had a pH of 7.5.

  Then, after cooling, the reaction product (toner base material) was filtered and washed with ion-exchanged water three times. The toner base thus obtained was dried at 40 ° C. for 6 hours with a fluid-type dryer to obtain a toner base M2. When observed with a Coulter counter (manufactured by Coulter Co., Ltd .: Multisizer 2), the volume average particle diameter was 5.9 μm and the coefficient of variation was 16.2.

(3) Preparation of toner base M3 In a four-necked flask having 2000 ml of a thermometer and a cooling tube, 204 g of the first resin particle dispersion RL2, 6 g of the second resin particle dispersion RD5, and colorant particle dispersion PM1 20 g, wax particle dispersion WA5 40 g, and ion-exchanged water 200 ml were added, and mixed for 10 min using a homogenizer (manufactured by IKA: Ultra Tarrax T50) to prepare a mixed particle dispersion. The pH of the obtained mixed dispersion was 2.0.

  Thereafter, 1N NaOH was added to the obtained mixed dispersion to adjust the pH to 11.4, and then 200 g of a 30% strength magnesium sulfate aqueous solution was added and stirred for 10 minutes. Thereafter, the temperature was raised from 22 ° C. to 70 ° C. at a rate of 5 ° C./min, and then heated at 70 ° C. for 2 hours. Thereafter, the temperature was raised to 85 ° C. and treated for 5 hours to obtain aggregated particles. The obtained aggregated particle dispersion had a pH of 8.7.

  Then, after cooling, the reaction product (toner base material) was filtered and washed with ion-exchanged water three times. The toner base thus obtained was dried at 40 ° C. for 6 hours with a fluid-type dryer to obtain a toner base M3. When observed with a Coulter counter (manufactured by Coulter Inc .: Multisizer 2), the volume average particle diameter was 4.8 μm and the coefficient of variation was 17.5.

(4) Preparation of toner base M4 In a 4-ml flask having a thermometer and a cooling tube, 2000 ml, 204 g of the first resin particle dispersion RL1, 20 g of the colorant particle dispersion PM1, 40 g of the wax particle dispersion WA5, 200 ml of ion-exchanged water was added and mixed for 10 minutes using a homogenizer (manufactured by IKA: Ultra Tarrax T50) to prepare a mixed particle dispersion. The pH of the obtained mixed dispersion was 3.2.

  Thereafter, 1N NaOH was added to the obtained mixed dispersion to adjust the pH to 11.9, and then 200 g of a 30% strength magnesium sulfate aqueous solution was added and stirred for 10 minutes. Thereafter, the temperature was raised from 22 ° C. to 70 ° C. at a rate of 5 ° C./min, and then heated at 70 ° C. for 2 hours. Thereafter, the temperature was raised to 85 ° C. and treated for 5 hours to obtain aggregated particles. The obtained aggregated particle dispersion had a pH of 9.3. The volume average particle size was 3.0 μm, and the coefficient of variation was 16.1.

  Thereafter, the water temperature was 60 ° C., 10 g of the second resin particle dispersion RD5 and 40 g of the third resin particle dispersion RH4 for the shell were added, 1N NaOH was added, and the pH was adjusted to 8.6. The water temperature was heated at 80 ° C. for 0.5 hour, and then 1N HCl was added to adjust the pH to 6.6. Thereafter, the mixture was further heated at 90 ° C. for 2 hours. Then, after cooling, the reaction product (toner base material) was filtered and washed with ion-exchanged water three times. Thereafter, the obtained toner base was dried at 40 ° C. for 6 hours by a fluid drier to obtain a toner base M4 having a volume average particle size of 4.1 μm and a coefficient of variation of 17.5.

When the pH when the second and third resin particle dispersions (RH4 and RD5 in this example) were added was 5.0, the second resin particles hardly adhered and free resin particles increased. Further, when the pH was 9.0, secondary aggregation between the aggregated particles occurred, and the particles became coarse to about 13 μm.
When the pH after the heat treatment was 3.0, some of the resin particles once adhered were released and fine particles were generated. When 7.0, secondary agglomeration of the agglomerated particles occurred, and the particles were coarsened to about 14 μm.

(5) Preparation of toner base M5 In a 2000 ml four-necked flask with a thermometer and a cooling tube, 204 g of the first resin particle dispersion RL1, 20 g of the colorant particle dispersion PM1, and 30 g of the wax particle dispersion WA2 200 ml of ion-exchanged water was added and mixed for 10 minutes using a homogenizer (manufactured by IKA: Ultra Tarrax T50) to prepare a mixed particle dispersion. The pH of the obtained mixed dispersion was 0.8.

  Thereafter, 1N NaOH was added to the obtained mixed dispersion to adjust the pH to 9.7, and then 200 g of a 30% strength magnesium sulfate aqueous solution was added and stirred for 10 minutes. Thereafter, the temperature was raised from 22 ° C. to 70 ° C. at a rate of 5 ° C./min, and then heated at 70 ° C. for 2 hours. Thereafter, the temperature was raised to 85 ° C. and treated for 5 hours to obtain aggregated particles. The obtained aggregated particle dispersion had a pH of 7.2. The volume average particle size was 4.4 μm and the coefficient of variation was 13.1.

  Thereafter, the water temperature was adjusted to 60 ° C., 20 g of the second resin particle dispersion RD6 and 30 g of the third shell particle dispersion RH4 were added, 1N NaOH was added, and the pH was adjusted to 5.0.

The water temperature was then heated at 80 ° C. for 2 hours, after which 1N HCl was added to adjust the pH to 3.4.
Thereafter, the mixture was further heated at 90 ° C. for 2 hours.

  Then, after cooling, the reaction product (toner base material) was filtered and washed with ion-exchanged water three times. Thereafter, the obtained toner base was dried at 40 ° C. for 6 hours by a fluid drier to obtain a toner base M5 having a volume average particle size of 5.5 μm and a coefficient of variation of 14.

(6) Preparation of toner base M6 In a four-necked flask with 2000 ml of a thermometer and a cooling tube, 204 g of the first resin particle dispersion RL3, 20 g of the colorant particle dispersion PM1, 30 g of the wax particle dispersion WA4, 200 ml of ion-exchanged water was added and mixed for 10 minutes using a homogenizer (manufactured by IKA: Ultra Tarrax T50) to prepare a mixed particle dispersion. The pH of the obtained mixed dispersion was 1.8.

  Thereafter, 1N NaOH was added to the obtained mixed dispersion to adjust the pH to 11.2, and then 200 g of a 30% strength magnesium sulfate aqueous solution was added and stirred for 10 minutes. Thereafter, the temperature was raised from 22 ° C. to 70 ° C. at a rate of 5 ° C./min, and then heated at 70 ° C. for 2 hours. Thereafter, the temperature was raised to 85 ° C. and treated for 5 hours to obtain aggregated particles. The obtained aggregated particle dispersion had a pH of 8.5. The volume average particle size was 4.1 μm, and the coefficient of variation was 14.9.

  Thereafter, the water temperature was 60 ° C., 6 g of the second resin particle dispersion RD7 and 40 g of the third resin particle dispersion RH4 for the shell were added, and 1N NaOH was added to adjust the pH to 6.8.

Then, the water temperature was heated at 80 ° C. for 1 hour, and then 1N HCl was added to adjust the pH to 5.0.
Thereafter, the mixture was further heated at 90 ° C. for 5 hours.

  Then, after cooling, the reaction product (toner base material) was filtered and washed with ion-exchanged water three times. Thereafter, the obtained toner base was dried at 40 ° C. for 6 hours by a fluid drier to obtain a toner base M6 having a volume average particle size of 5.3 μm and a coefficient of variation of 15.2.

(7) Preparation of toner base M7 In a four-necked flask with 2000 ml of a thermometer and a cooling tube, 204 g of the first resin particle dispersion RL3, 20 g of the colorant particle dispersion PM1, 40 g of the wax particle dispersion WA6, 200 ml of ion-exchanged water was added and mixed for 10 minutes using a homogenizer (manufactured by IKA: Ultra Tarrax T50) to prepare a mixed particle dispersion. The pH of the obtained mixed dispersion was 1.8.

  Thereafter, 1N NaOH was added to the obtained mixed dispersion to adjust the pH to 11.2, and then 200 g of a 30% strength magnesium sulfate aqueous solution was added and stirred for 10 minutes. Thereafter, the temperature was raised from 22 ° C. to 70 ° C. at a rate of 5 ° C./min, and then heated at 70 ° C. for 2 hours. Thereafter, the temperature was raised to 85 ° C. and treated for 5 hours to obtain aggregated particles. The obtained aggregated particle dispersion had a pH of 8.5. The volume average particle size was 4.0 μm, and the coefficient of variation was 15.2.

  Thereafter, the water temperature was adjusted to 60 ° C., 10 g of the second resin particle dispersion RD6 and 35 g of the third shell resin particle dispersion RH8 were added, and 1N NaOH was added to adjust the pH to 6.8.

Then, the water temperature was heated at 80 ° C. for 1 hour, and then 1N HCl was added to adjust the pH to 5.0.
Thereafter, the mixture was further heated at 90 ° C. for 5 hours.

  Then, after cooling, the reaction product (toner base material) was filtered and washed with ion-exchanged water three times. Thereafter, the obtained toner base was dried at 40 ° C. for 6 hours by a fluid drier to obtain a toner base M7 having a volume average particle size of 5.1 μm and a coefficient of variation of 16.7.

(8) Preparation of toner base M8 In a four-necked flask with 2000 ml of a thermometer and a cooling tube, 204 g of the first resin particle dispersion RL3, 20 g of the colorant particle dispersion PM1, 40 g of the wax particle dispersion WA7, 200 ml of ion-exchanged water was added and mixed for 10 minutes using a homogenizer (manufactured by IKA: Ultra Tarrax T50) to prepare a mixed particle dispersion. The pH of the obtained mixed dispersion was 1.8.

  Thereafter, 1N NaOH was added to the obtained mixed dispersion to adjust the pH to 11.2, and then 200 g of a 30% strength magnesium sulfate aqueous solution was added and stirred for 10 minutes. Thereafter, the temperature was raised from 22 ° C. to 70 ° C. at a rate of 5 ° C./min, and then heated at 70 ° C. for 2 hours. Thereafter, the temperature was raised to 85 ° C. and treated for 5 hours to obtain aggregated particles. The obtained aggregated particle dispersion had a pH of 8.5. The volume average particle diameter was 3.8 μm, and the coefficient of variation was 17.2.

  Thereafter, the water temperature was adjusted to 60 ° C., 4 g of the second resin particle dispersion RD7 and 30 g of the third resin particle dispersion RH8 for the shell were added, and 1N NaOH was added to adjust the pH to 6.8.

Then, the water temperature was heated at 80 ° C. for 1 hour, and then 1N HCl was added to adjust the pH to 5.0.
Thereafter, the mixture was further heated at 90 ° C. for 5 hours.

  Then, after cooling, the reaction product (toner base material) was filtered and washed with ion-exchanged water three times. Thereafter, the obtained toner base was dried at 40 ° C. for 6 hours by a fluid drier to obtain a toner base M8 having a volume average particle size of 4.9 μm and a coefficient of variation of 18.7.

(9) Preparation of toner base m9 In a four-necked flask with 2000 ml of thermometer and cooling tube, 204 g of resin particle dispersion RL2, 20 g of colorant particle dispersion PM1, 30 g of wax particle dispersion wa8, ion-exchanged water 200 ml was added, and mixed for 10 minutes using a homogenizer (manufactured by IKA: Ultra Turrax T50) to prepare a mixed particle dispersion.

  1N NaOH was added to the obtained mixed particle dispersion to adjust the pH to 8.8, and then 200 g of a 30% strength magnesium sulfate aqueous solution was added and stirred for 10 min. Thereafter, the temperature was raised from 22 ° C. to 70 ° C. at a rate of 5 ° C./min, and then heated at 70 ° C. for 2 hours. Thereafter, the temperature was raised to 85 ° C. and treated for 5 hours to obtain aggregated particles. The resulting aggregated particle dispersion had a pH of 6.0.

  Then, after cooling, the reaction product (toner base material) was filtered and washed with ion-exchanged water three times. The toner base thus obtained was dried at 40 ° C. for 6 hours with a fluid dryer to obtain toner base m9 having a volume average particle size of 10.8 μm and a coefficient of variation of 38.8.

(10) Preparation of toner base m10 In a four-necked flask with 2000 ml of thermometer and cooling tube, 204 g of resin particle dispersion RL2, 20 g of colorant particle dispersion PM1, 30 g of wax particle dispersion wa9, ion-exchanged water 200 ml was added, and mixed for 10 minutes using a homogenizer (manufactured by IKA: Ultra Turrax T50) to prepare a mixed particle dispersion.

  1N NaOH was added to the obtained mixed particle dispersion to adjust the pH to 9.1, and then 200 g of a 30% strength magnesium sulfate aqueous solution was added and stirred for 10 min. Thereafter, the temperature was raised from 22 ° C. to 70 ° C. at a rate of 5 ° C./min, and then heated at 70 ° C. for 2 hours. Thereafter, the temperature was raised to 85 ° C. and treated for 5 hours to obtain aggregated particles. The obtained aggregated particle dispersion had a pH of 6.2.

  Then, after cooling, the reaction product (toner base material) was filtered and washed with ion-exchanged water three times. Thereafter, the obtained toner base was dried at 40 ° C. for 6 hours by a fluid drier to obtain a toner base m10 having a volume average particle size of 9.2 μm and a coefficient of variation of 39.9.

(11) Preparation of toner base m11 A 2000 ml four-necked flask having a thermometer and a cooling tube, 204 g of resin particle dispersion RL2, 20 g of colorant particle dispersion PM1, 30 g of wax particle dispersion wa10, and 200 ml of ion-exchanged water Was mixed for 10 min using a homogenizer (manufactured by IKA: Ultra Turrax T50) to prepare a mixed particle dispersion.

  1N NaOH was added to the obtained mixed particle dispersion to adjust the pH to 9.3, and then 200 g of a 30% strength magnesium sulfate aqueous solution was added and stirred for 10 min. Thereafter, the temperature was raised from 22 ° C. to 70 ° C. at a rate of 5 ° C./min, and then heated at 70 ° C. for 2 hours. Thereafter, the temperature was raised to 85 ° C. and treated for 5 hours to obtain aggregated particles. The resulting aggregated particle dispersion had a pH of 6.5.

  Then, after cooling, the reaction product (toner base material) was filtered and washed with ion-exchanged water three times. Thereafter, the obtained toner base was dried at 40 ° C. for 6 hours by a fluid drier to obtain a toner base m11 having a volume average particle size of 8.1 μm and a coefficient of variation of 42.1.

Table 8 shows the external additives used in this example. The amount of charge was measured by the blow-off method of frictional charging with an uncoated ferrite carrier. In an environment of 25 ° C. and 45 RH%, 50 g of carrier and 0.1 g of silica, etc. are mixed in a 100 ml polyethylene container, and stirred for 5 minutes and 30 minutes at a speed of 100 min ⁻¹ by longitudinal rotation. Then, nitrogen gas was blown with 1.96 × 10 ⁴ (Pa) for 1 minute.

  For negative chargeability, the 5-minute value is preferably −100 to −800 μC / g, and the 30-minute value is preferably −50 to −600 μC / g. Highly charged silica can function with a small amount of addition.

  Table 9 shows the toner material composition used in this example. Other black toner, cyan toner, and yellow toner used PB1, PC1, and PY1 as pigments, and other compositions were the same as the magenta toner composition.

The external additive indicates a blending amount (parts by weight) with respect to 100 parts by weight of the toner base. The external addition process was performed in FM20B with a stirring blade Z0S0 type, a rotational speed of 2000 min ⁻¹ , a processing time of 5 min, and an input amount of 1 kg.

  FIG. 1 is a cross-sectional view showing a configuration of an image forming apparatus for forming a full-color image used in this embodiment. In FIG. 1, the outer casing of the color electrophotographic printer is omitted.

  The transfer belt unit 17 includes a transfer belt 12, a first color (yellow) transfer roller 10Y made of an elastic body, a second color (magenta) transfer roller 10M, a third color (cyan) transfer roller 10C, and a fourth color (black). Transfer roller 10K, drive roller 11 made of aluminum roller, second transfer roller 14 made of elastic body, second transfer driven roller 13, belt cleaner blade 16 for cleaning the toner image remaining on the transfer belt 12, and opposed to the cleaner blade A roller 15 is provided at a position to be used.

  At this time, the distance from the first color (Y) transfer position to the second color (M) transfer position is 70 mm (second color (M) transfer position to third color (C) transfer position, third color (C). The fourth color (K) transfer position is the same distance from the transfer position), and the peripheral speed of the photosensitive member is 125 mm / s.

The transfer belt 12 is used by kneading a conductive filler in an insulating polycarbonate resin and forming a film with an extruder. In the present example, a film obtained by adding 5 parts by weight of conductive carbon (for example, ketjen black) to 95 parts by weight of polycarbonate resin (for example, Iupilon Z300, manufactured by Mitsubishi Gas Chemical) as the insulating resin was used. Further, the surface is coated with a fluororesin, the thickness is about 100 μm, the volume resistance is 10 ⁷ to 10 ¹² Ω · cm, and the surface resistance is 10 ⁷ to 10 ¹² Ω / □. This is also for improving dot reproducibility. This is for the purpose of effectively preventing loosening and charge accumulation due to long-term use of the transfer belt 12, and the reason that the surface is coated with fluororesin is that the toner filming on the surface of the transfer belt after long-term use. This is so that it can be effectively prevented. If the volume resistance is less than 10 ⁷ Ω · cm, retransfer is likely to occur, and if it is greater than 10 ¹² Ω · cm, the transfer efficiency deteriorates.

The first transfer roller is a carbon conductive urethane foam roller having an outer diameter of 8 mm, and the resistance value is 10 ² to 10 ⁶ Ω. During the first transfer operation, the first transfer roller 10 is pressed against the photoreceptor 1 with a pressing force of 1.0 to 9.8 (N) via the transfer belt 12, and the toner on the photoreceptor is transferred onto the belt. Is done. When the resistance value is smaller than 10 ² Ω, retransfer is likely to occur. Larger transfer defects are more likely to occur than 10 ⁶ Ω. If it is less than 1.0 (N), transfer defects occur, and if it is greater than 9.8 (N), transfer character omission occurs.

The second transfer roller 14 is a carbon conductive foamed urethane roller having an outer diameter of 10 mm, and the resistance value is 10 ² to 10 ⁶ Ω. The second transfer roller 14 is pressed against the transfer roller 13 via the transfer belt 12 and a transfer medium 19 such as paper or OHP. The transfer roller 13 is configured to be driven to rotate by the transfer belt 12. In the second transfer, the second transfer roller 14 and the counter transfer roller 13 are pressed against each other with a pressing force of 5.0 to 21.8 (N), and the toner is transferred from the transfer belt onto the recording material 19 such as paper. The When the resistance value is smaller than 10 ² Ω, retransfer is likely to occur. Larger transfer defects are more likely to occur than 10 ⁶ Ω. If it is smaller than 5.0 (N), transfer failure occurs. If it is larger than 21.8 (N), the load increases and jitter tends to occur.

  Four sets of image forming units 18Y, 18M, 18C, and 18K for each color of yellow (Y), magenta (M), cyan (C), and black (B) are arranged in series as shown in the figure.

  Each of the image forming units 18Y, 18M, 18C, and 18K is composed of the same constituent members except for the developer contained therein, so that the Y image forming unit 18Y will be described to simplify the description, and the units for other colors The description of is omitted.

  The image forming unit is configured as follows. 1 is a photosensitive member, 3 is a pixel laser signal light, 4 is a developing roller having an outer diameter of 10 mm made of aluminum having a magnet having a magnetic force of 1200 gauss, and is opposed to the photosensitive member with a gap of 0.3 mm. Rotate in the direction of. 6 is a stirring roller that stirs the toner and carrier in the developing device and supplies them to the developing roller. The composition ratio of the carrier and the toner is read by a magnetic permeability sensor (not shown) and is supplied from a toner hopper (not shown) in a timely manner. A metal magnetic blade 5 regulates the magnetic brush layer of the developer on the developing roller. The developer amount is 150 g. The gap was 0.4 mm. Although the power source is omitted, a direct current of −500 V and an alternating voltage of 1.5 kV (pp) and a frequency of 6 kHz are applied to the developing roller 4. The peripheral speed ratio between the photoreceptor and the developing roller was 1: 1.6. The mixing ratio of toner and carrier was 93: 7, and the developer amount in the developing unit was 150 g.

  A charging roller 2 having an outer diameter of 10 mm made of epichlorohydrin rubber is applied with a DC bias of -1.2 kV. The surface of the photoreceptor 1 is charged to −600V. 8 is a cleaner, 9 is a waste toner box, and 7 is a developer.

  The paper is transported from below the transfer unit 17 so that the paper 19 is fed by a paper feed roller (not shown) to the nip portion where the transfer belt 12 and the second transfer roller 14 are pressed. A conveyance path is formed.

  The toner on the transfer belt 12 is transferred to the paper 19 by +1000 V applied to the second transfer roller 14, and includes a fixing roller 201, a pressure roller 202, a fixing belt 203, a heating medium roller 204, and an induction heater unit 205. It is conveyed to the fixing unit and fixed there.

  FIG. 2 shows the fixing process. A belt 203 is placed between the fixing roller 201 and the heat roller 204. A predetermined load is applied between the fixing roller 201 and the pressure roller 202, and a nip is formed between the belt 203 and the pressure roller 202. An induction heater unit 205 including a ferrite core 206 and a coil 207 is provided on the outer peripheral surface of the heat roller 204, and a temperature sensor 208 is provided on the outer surface.

  The belt has a structure in which 30 μm of Ni is used as a base, silicone rubber is 150 μm thereon, and further, PFA tube is 30 μm.

  The pressure roller 202 is pressed against the fixing roller 201 by a pressure spring 209. The recording material 19 having the toner 210 moves along the guide plate 211.

  A fixing roller 201 as a fixing member is a silicone rubber having a rubber hardness (JIS-A) of 20 degrees according to JIS standard on the surface of an aluminum hollow roller metal core 213 having a length of 250 mm, an outer diameter of 14 mm, and a thickness of 1 mm. An elastic layer 214 having a thickness of 3 mm is provided. A silicone rubber layer 215 is formed thereon with a thickness of 3 mm and has an outer diameter of about 20 mm. It receives a driving force from a driving motor (not shown) and rotates at 125 mm / s.

  The heat roller 204 is a hollow pipe having a thickness of 1 mm and an outer diameter of 20 mm. The surface temperature of the fixing belt was controlled to 170 ° using a thermistor.

  The pressure roller 202 as a pressure member has a length of 250 mm and an outer diameter of 20 mm. This is provided with a 2 mm thick elastic layer 217 made of silicone rubber having a rubber hardness (JIS-A) of 55 degrees according to JIS standards on the surface of a hollow roller metal core 216 made of aluminum having an outer diameter of 16 mm and a thickness of 1 mm. . The pressure roller 202 is rotatably installed, and a nip width of 5.0 mm is formed between the pressure roller 202 and the fixing roller 201 by a spring-loaded spring 209 on one side 147N.

  The operation will be described below. In the full color mode, all of the first transfer rollers 10 of Y, M, C, and K are pushed up and press the photoreceptor 1 of the image forming unit via the transfer belt 12. At this time, a DC bias of +800 V is applied to the first transfer roller. An image signal is sent from the laser beam 3 and is incident on the photoreceptor 1 whose surface is charged by the charging roller 2 to form an electrostatic latent image. The toner on the developing roller 4 that rotates in contact with the photoreceptor 1 visualizes the electrostatic latent image formed on the photoreceptor 1.

  At this time, the image forming speed of the image forming unit 18Y (125 mm / s equal to the peripheral speed of the photoconductor) and the moving speed of the transfer belt 12 are 0.5 to 1.5% slower than the transfer belt speed. Is set to

  In the image forming process, the Y signal light 3Y is input to the image forming unit 18Y, and image formation with Y toner is performed. Simultaneously with the image formation, the first transfer roller 10Y causes the Y toner image to be transferred from the photoreceptor 1Y to the transfer belt 12. At this time, a DC voltage of +800 V was applied to the first transfer roller 10Y.

  With a time lag between the first color (Y) first transfer and the second color (M) first transfer, M signal light 3M is input to the image forming unit 18M, and image formation with M toner is performed. Simultaneously with the image formation, the M toner image is transferred from the photosensitive member 1M to the transfer belt 12 by the action of the first transfer roller 10M. At this time, the first color (Y) toner is formed and the M toner is transferred. Similarly, image formation with C (cyan) and K (black) toners is performed, and a YMCK toner image is formed on the transfer belt 12 by the action of the first transfer rollers 10C and 10B simultaneously with the image formation. This is a so-called tandem method.

  On the transfer belt 12, toner images of four colors are positioned and overlapped to form a color image. After the transfer of the final B toner image, the four color toner images are collectively transferred to the paper 19 fed from a paper feed cassette (not shown) at the same time by the action of the second transfer roller 14. At this time, the transfer roller 13 was grounded, and a DC voltage of +1 kV was applied to the second transfer roller 14. The toner image transferred to the paper was fixed by a pair of fixing rollers 201 and 202. The paper was then discharged out of the apparatus through a pair of discharge rollers (not shown). The residual transfer toner remaining on the intermediate transfer belt 12 was cleaned by the action of the cleaning blade 16 to prepare for the next image formation.

  Table 10 shows the results of image output using the electrophotographic apparatus shown in FIG. In Table 11, the state of transfer failure in the character portion of a full-color image in which the toners are magenta, cyan, and yellow are overlapped, and the paper wrapping property on the fixing belt in fixing is evaluated.

The charge amount is measured by the blow-off method of frictional charging with the ferrite carrier. In an environment of 25 ° C. and 45% RH, 0.3 g of a sample for durability evaluation was collected and blown with nitrogen gas 1.96 × 10 ⁴ (Pa) for 1 minute.

When an image was produced using a developer, the image was very high resolution with a uniform solid black image and 16 lines / mm. A high density image having an image density of 1.3 or higher was obtained. In addition, the ground cover of the non-image area did not occur. Further, even in the long-term durability test of 1 million A4 sheets, both the fluidity and the image density showed a stable characteristic with little change. In addition, the uniformity when the entire solid image was taken at the time of development was also good. There is no development memory. Even during continuous use, no abnormal image of the vertical muscles occurred. There is almost no spent toner component on the carrier. There is little change in carrier resistance and decrease in charge amount, and fog does not occur. The charge rising property at the time of rapid toner replenishment was also good, and there was no phenomenon that fogging increased in a high humidity environment. Also, when used for a long time, a high saturation charge amount was obtained and could be maintained for a long time. Fluctuations in charge amount under low temperature and low humidity hardly occur. Also, in the transfer, the void is at a level that causes no problem in practical use, and the transfer efficiency is about 95%. Further, the filming of the toner on the photosensitive member and the transfer belt was at a level where there was no practical problem. There was no defective cleaning of the transfer belt. Also, there is almost no toner disturbance or toner skipping during fixing. In addition, in the full-color image in which the three colors overlap, no transfer failure occurred, and no paper wrapping around the fixing belt occurred during fixing.
For cm1, cm2, cm3, and cm4, the toner and developer have a process speed of 100 mm / s, and when the distance between the photoconductors is 70 mm, the characters are scattered at the time of transfer, the transferred characters are missing, and the reverse transferability is acceptable. The image uniformity was good, but the solid image uniformity was slightly deteriorated when the process speed was increased to 125 mm / s or when the distance between the photoconductors was 60 mm.
In cm1 and cm3, an increase in charge occurred and the image density decreased. The fog was also noticeable at cm2 and cm4. In addition, when the entire surface was continuously taken with two-component development and the toner was replenished rapidly, charge reduction occurred and fogging increased. The phenomenon worsened particularly in a high humidity environment.

Next, a solid image with a deposit amount of 1.2 mg / cm ² was evaluated for OHP transmittance (fixing temperature 160 ° C.) and offset property at high temperature using a fixing device using a belt with a process speed of 125 mm / s and no oil applied. did. The OHP transmittance was measured with a spectrophotometer U-3200 (Hitachi, Ltd.) for the transmittance of 700 nm light. Storage stability shows the result after standing at 60 ° C. for 5 hours.

  No OHP jam occurred at the fixing nip. In the full-solid image of plain paper, no offset occurred at 200,000 sheets. Even if the oil is not applied with a silicone or fluorine-based fixing belt, the surface deterioration phenomenon of the belt is not observed. The OHP translucency was 80% or more, and the non-offset temperature range was obtained in a wide range in the fixing roller not using oil. In addition, almost no aggregation was observed in the storage stability at 60 ° C. for 5 hours (◯ level).

  The present invention is useful not only for an electrophotographic system using a photoconductor but also for a system in which toner is directly attached to paper for printing.

1 is a cross-sectional view illustrating a configuration of an image forming apparatus used in an embodiment of the present invention. FIG. 3 is a cross-sectional view illustrating a configuration of a fixing unit used in one embodiment of the present invention. 1 is a schematic view of a stirring and dispersing device used in one embodiment of the present invention. The figure seen from the stirring dispersion | distribution apparatus used in one Example of this invention. 1 is a schematic view of a stirring and dispersing device used in one embodiment of the present invention. The figure seen from the stirring dispersion | distribution apparatus used in one Example of this invention. The schematic process drawing which shows the manufacturing method of one Example of this invention. AB is process drawing which shows the aggregation processing operation of one Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging roller 3 Laser signal light 4 Developing roller 5 Blade 10 1st transfer roller 12 Transfer belt 14 2nd transfer roller 13 Drive tension roller 17 Transfer belt unit 18B, 18C, 18M, 18Y Image forming unit 18 Image forming unit Group 201 Fixing roller 202 Pressure roller 203 Fixing belt 205 Induction heater unit 206 Ferrite core 40 Stirring dispersion device 41 Outer tank 42 Dam plate 43 Rotating body 46 Shaft 47 Cooling water inlet 48 Cooling water outlet 80 Raw material inlet 81 Spring 82 Fixed body 83 Rotating body 84 Shaft 85 Fine particles

Claims (22)

  First resin particle dispersion in which resin particles are dispersed, colorant particle dispersion in which colorant particles are dispersed, wax particle dispersion in which wax is dispersed, and acrylic sulfone having a sulfonic acid-based polar group An inorganic toner having an average particle size in the range of 6 nm to 200 nm is mixed with a second resin (charge control resin) containing an acid copolymer in a water base, and at least a part of the toner base is melted by heating. A toner which is a fine powder and is added in an amount of 1.0 to 6 parts by weight with respect to 100 parts by weight of the toner base.   The toner has a first resin particle dispersion in which resin particles are dispersed, a colorant particle dispersion in which colorant particles are dispersed, a wax particle dispersion in which wax is dispersed, and a sulfonic acid-based polar group. A second resin (charge control resin) containing an acrylic sulfonic acid copolymer is mixed to a pH of 6.0 or less, and the pH is adjusted to 9.5 to 12 before addition of the water-soluble inorganic salt and before heating. .2 is adjusted, and then a water-soluble inorganic salt is added, and heat treatment is performed to form aggregated particles in which at least resin particles, colorant particles and wax particles are aggregated, and the aggregated particles are formed. The toner according to claim 1, wherein the toner is obtained by controlling the pH in a range of 7.0 to 9.5.   The first resin particle dispersion in which the resin particles are dispersed, the colorant particle dispersion in which the colorant particles are dispersed, and the wax particle dispersion in which the wax is dispersed are mixed and aggregated in an aqueous system, and at least partly To the toner base in which a second resin (charge control resin) containing at least an acrylic sulfonic acid-based copolymer having a sulfonic acid-based polar group is heated and fused to the surface of the heat-melted particles. The toner is characterized in that an inorganic fine powder having an average particle diameter of 6 nm to 200 nm is added in a range of 1.0 to 6 parts by weight with respect to 100 parts by weight of the toner base. The toner base particles have a volume average particle diameter of 3 to 7 μm, a toner base particle content of 2.5 to 4 μm in the number distribution is 10 to 75% by number, and 4 to 6.06 μm in the volume distribution. Toner base particles having a diameter of 25 to 75% by volume, and toner base particles having a particle size of 8 μm or more in the volume distribution are contained in an amount of 5% by volume or less,
When the volume% of toner base particles having a particle diameter of 4 to 6.06 μm in the volume distribution is V46, and the number% of toner base particles having a particle diameter of 4 to 6.06 μm in the number distribution is P46, The toner according to claim 1, wherein P46 / V46 is in the range of 0.5 to 1.5. The charge control resin has a weight average molecular weight of 3 × 10 ³ to 8 × 10 ⁴ , a Z average molecular weight of 5 × 10 ^{3 to} 5 × 10 ⁵ , and a ratio of the weight average molecular weight to the number average molecular weight in GPC of THF-soluble matter. Acrylic sulfone having a sulfonic acid polar group having a weight average molecular weight / number average molecular weight of 1.5 to 50 and a ratio of Z average molecular weight to number average molecular weight (Z average molecular weight / number average molecular weight) of 5 to 100. The toner according to claim 1, which is an acid copolymer.   The toner according to claim 1, wherein the acrylic sulfonic acid copolymer is a copolymer of 2-acrylamido-2-methylpropane sulfonic acid and a vinyl monomer.   The toner according to claim 1, wherein the wax contains an ester wax having an iodine value of 25 or less, a saponification value of 30 to 300, and an endothermic peak temperature (melting point) by DSC method of 50 to 100 ° C.   The wax has an acid value of 10 to 80 mg KOH / g and a melting point of 50 to 50 obtained by a reaction with a long-chain alkyl alcohol having at least 4 to 30 carbon atoms, an unsaturated polycarboxylic acid or an anhydride thereof, and an unsaturated hydrocarbon wax. The toner according to claim 1, comprising a 120 ° C. wax. In the molecular weight distribution in gel permeation chromatography (GPC), the wax has a number average molecular weight of 100 to 5000, a weight average molecular weight of 200 to 10,000, and a ratio of the weight average molecular weight to the number average molecular weight (weight average molecular weight / number average molecular weight). Is 1.01 to 8, the ratio of the Z average molecular weight to the number average molecular weight (Z average molecular weight / number average molecular weight) is 1.02 to 10, and the molecular weight is 5 × 10 ² to 1 × 10 ^4. The toner according to claim 1, comprising an ester-based wax having a peak and a loss on heating at 220 ° C. of 8% by weight or less.   The inorganic fine powder having an average particle diameter of 6 nm to 20 nm is 0.5 to 2.5 parts by weight based on 100 parts by weight of the toner base, and the inorganic fine powder having an average particle diameter of 20 nm to 200 nm is based on 100 parts by weight of the toner base. The toner according to claim 1 or 3, wherein 0.5 to 3.5 parts by weight of the external additive is added.   An inorganic fine powder having an average particle size of 6 nm to 20 nm and an ignition loss of 1.5 to 25 wt% is 0.5 to 2.5 parts by weight with respect to 100 parts by weight of the toner base, an average particle size of 20 nm to 200 nm, strong 4. The toner according to claim 1, wherein 0.5 to 3.5 parts by weight of an inorganic fine powder having a heat loss of 0.5 to 23 wt% is further added to 100 parts by weight of the toner base.   When the volume particle size distribution of the wax particles dispersed in the wax particle dispersion is integrated from the small particle size side, the 16% diameter (PR16) is 20 to 200 nm and the 50% diameter (PR50) is 20 to 200 nm. The toner according to claim 1, wherein the toner has a diameter of 40 to 300 nm and an 84% diameter (PR84) of 400 nm or less.   In the aqueous medium, at least the first resin particle dispersion in which the first resin particles are dispersed, and the charge control resin particles containing an acrylic sulfonic acid copolymer having a sulfonic acid polar group are dispersed. The second resin particle dispersion, the colorant particle dispersion in which the colorant particles are dispersed, and the wax particle dispersion in which the wax particles are dispersed are mixed to obtain a mixed dispersion, and heat aggregation treatment is performed, so that at least the first A method for producing a toner, comprising: agglomerated particles obtained by aggregating the resin particles, the second resin particles, the colorant particles, and the wax particles. In the aqueous medium, at least the first resin particle dispersion in which the first resin particles are dispersed, and the charge control resin particles containing an acrylic sulfonic acid copolymer having a sulfonic acid polar group are dispersed. Creating a mixed dispersion having a pH of 6.0 or less by mixing the second resin particle dispersion, the colorant particle dispersion in which the colorant particles are dispersed, and the wax particle dispersion in which the wax particles are dispersed;
Adjusting the pH to a range of 9.5 to 12.2 before adding the water-soluble inorganic salt and before heating;
Thereafter, a water-soluble inorganic salt is added, and heat treatment is performed to form aggregated particles in which at least a part of at least the first resin particles, the second resin particles, the colorant particles, and the wax particles are melted is melted. And forming a process,
The method for producing a toner according to claim 13, wherein a pH when the aggregated particles are formed is in a range of 7.0 to 9.5. In an aqueous medium, at least the first resin particle dispersion in which the first resin particles are dispersed, the colorant particle dispersion in which the colorant particles are dispersed, and the wax particle dispersion in which the wax particles are dispersed are mixed. And heat aggregation treatment to produce aggregated particles in which at least the first resin particles, the colorant particles, and the wax particles are aggregated;
A second resin particle dispersion in which second resin particles containing at least an acrylic sulfonic acid copolymer having a sulfonic acid polar group is dispersed is mixed with the aggregated particle dispersion in which the aggregated particles are dispersed. And a step of fusing the second resin particles containing the acrylic sulfonic acid copolymer having at least the sulfonic acid polar group on the surface of the aggregated particles. Manufacturing method. After adding the second resin particle dispersion in which the second resin particles containing the acrylic sulfonic acid copolymer having at least the sulfonic acid polar group are dispersed, the pH is set to 5.2 to 8.8. Adjusting to the range of
Heat treatment at a temperature equal to or higher than the glass transition temperature of the second resin particles;
adjusting the pH to a range of 3.2 to 6.8;
The method for producing a toner according to claim 15, further comprising: heat-treating the second resin particles at a temperature equal to or higher than a glass transition temperature of the second resin particles, and fusing the second resin particles to the aggregated particles. A toner according to claim 1;
A two-component developer comprising a carrier containing magnetic particles coated at least on the surface of a core material with a fluorine-modified silicone resin containing an aminosilane coupling agent.   The two-component developer according to claim 17, wherein the fluorine-modified silicone resin is a crosslinkable fluorine-modified silicone resin obtained from a reaction between a perfluoroalkyl group-containing organosilicon compound and a polyorganosiloxane. Perfluoroalkyl group-containing organosilicon compounds include CF ₃ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , C ₄ F ₉ CH ₂ CH ₂ Si (CH ₃ ) (OCH ₃ ) ₂ , C ₈ F ₁₇ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , C ₈ F ₁₇ CH ₂ CH ₂ Si (OC ₂ H ₅ ) ₃ , (CF ₃ ) ₂ CF (CF ₂ ) ₈ CH ₂ CH ₂ Si (OCH ₃ ) _3, etc. The two-component developer according to claim 18, which is at least one. The two-component developer according to claim 18, wherein the polyorganosiloxane is at least one selected from the following (Chemical Formula 1) and (Chemical Formula 2).

  Crosslinkable fluorine-modified silicone obtained by a reaction in which the fluorine-modified silicone resin is a reaction in which the organosilicon compound containing a perfluoroalkyl group is 3 parts by weight or more and 20 parts by weight or less with respect to 100 parts by weight of the polyorganosiloxane. The two-component developer according to claim 17 or 18, which is a resin.   And a plurality of toner image forming stations including at least an image carrier, a charging unit for forming an electrostatic latent image on the image carrier and a toner carrier, and an electrostatic latent image formed on the image carrier. The toner image developed with the toner according to any one of 1 to 12 or the two-component developer according to any one of 17 to 21 and visualized the electrostatic latent image is successively transferred onto a transfer medium. A transfer system configured to execute a transfer process for transferring, wherein the transfer process is a distance from a first transfer position to a second transfer position, or a second transfer position to a third transfer position; Or the distance from the third transfer position to the fourth transfer position is d1 (mm), and the peripheral speed of the photoreceptor is v (mm / s), d1 / v ≦ 0.65 (sec. ) That satisfies the conditions of Forming apparatus.

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