JP2008158037A - Toner, method for manufacturing toner, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide toner capable of achieving a longer lifetime and preventing occurrence of void and scattering in transfer, or a method for manufacturing toner by which a small particle diameter toner having a sharp particle size distribution can be made without requiring a classification step. <P>SOLUTION: The toner contains core particles formed by aggregating at least first resin particles, colorant particles and wax particles in an aqueous medium, wherein the colorant contains C.I. Pigment Yellow 74 as an azo pigment, the wax contains a wax having an endothermic peak temperature by the DSC method of 50-120°C, and a definite relationship is provided to the hydrophile-lipophile balances (HLB) of surfactants used in a dispersion of the colorant particles and in a dispersion of the wax particles, respectively. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a copying machine, a laser printer, plain paper FAX, a color PPC, a color laser printer, a color FAX, a toner used in these multifunction peripherals, a toner manufacturing method, and an image forming apparatus.

  In recent years, image forming apparatuses such as printers are shifting from the purpose of office use to personal use, and there is a demand for technology for realizing miniaturization, high speed, high image quality, and colorization. Therefore, a tandem color process that enables high-speed output of color images, and a clear color image with high glossiness and high translucency and non-offset properties without using fixing oil for preventing offset during fixing. Oilless fixing is required along with conditions such as good maintainability 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 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. For high image quality, it is essential to reduce the particle size of the toner and to have a narrow particle size distribution.

  The toner is generally composed of a resin component, which is a binder resin, a pigment, a charge control agent, and, if necessary, additional components such as a release agent. The toner is premixed at an appropriate ratio, and heated and kneaded by heat melting. Then, it is finely pulverized by an airflow type collision plate method and classified into fine powders to complete toner base particles. Thereafter, an external additive such as hydrophobic silica is externally added to the toner base particles 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.

  In the conventional pulverization / classification operation in the kneading and pulverization method, there is a limit to the particle size that can be actually provided economically and in performance even if the particle size is reduced. In addition, in order to improve the fixability, in the configuration in which a release agent such as a low melting point wax is added, since the toner has a high cohesive property, the tendency of toner image disturbance and transfer failure during transfer is more prominent. It becomes 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.

  Therefore, a toner production method using various polymerization methods different from the kneading and pulverization method has been studied.

  In Patent Document 1 below, a toner comprising particles formed by polymerization and a coating layer made of fine particles formed by emulsion polymerization on the surface of the particles, and a water-soluble inorganic salt is added to the surface of the particles. The structure which produces | generates the coating layer by particle | grains and the structure which produces | generates the coating layer by microparticles on the particle | grain surface by changing the pH of a solution are disclosed.

  In the following Patent Document 2, a step of forming aggregated particles in a dispersion obtained by dispersing at least resin particles to prepare an aggregated particle dispersion, a resin fine particle dispersion in which resin fine particles are dispersed in the aggregated particle dispersion And a method for forming the adhering particles by adhering the resin particles to the agglomerated particles, and a process for heating and fusing the adhering particles. It is disclosed that it may be performed gradually and continuously, or may be performed stepwise by dividing into a plurality of times. And the effect which was excellent in the charging performance which suppressed generation | occurrence | production of a fine particle and the particle size distribution was sharp by adding and mixing the said resin fine particle (additional particle) is described.

  In Patent Document 3 below, the content of the surfactant in the toner particles is 3% by weight or less, and the inorganic metal salt having a charge of 2 or more, for example, zinc chloride is contained at 10 ppm or more and 1% by weight or less, and ion crosslinking. The structure which improves the moisture absorption resistance by forming is disclosed. After the resin fine particle dispersion and the colorant dispersion are mixed and the aggregate dispersion is adjusted using an inorganic metal salt, the toner is formed by heating above the glass transition point of the resin and fusing the aggregate. ing. Small toner particles having excellent charging characteristics, environmental dependency, cleaning properties, transferability, and sharp particle size distribution are described.

  In Patent Document 4 below, toner particles in which a resin layer (shell) formed by fusing resin particles by a salting-out / fusing method is formed on the surface of colored particles (core particles) containing a resin and a colorant. Disclosed is a configuration in which a dispersion of resin particles is added to a dispersion of colored particles to maintain a temperature above the glass transition temperature in succession to the salting-out / fusion process for obtaining colored particles. The amount of colorant present on the surface is small, and even if it is used for long-term image formation in a high-humidity environment, it does not cause changes in image density, fogging, and color due to changes in chargeability and developability. Is described.

  In the configuration in which these emulsified resin particles, wax particles, and pigment particles are aggregated to form particles, disclosure has been made regarding conditions such as an aggregating agent, temperature, and pH. However, if the balance of the aggregation speed of these particles is disturbed, for example, if the aggregation speed of the pigment is increased, the aggregation of the resin particles and the pigment particles proceeds rapidly, the wax is left behind, and the liquid remains cloudy. On the contrary, the pigment may be left behind and the liquid may remain in a yellow state, for example. In addition, when a resin layer is further attached to the core particles in which the resin particles, wax particles, and pigment particles are aggregated to form a core-shell structure, the adhesion of the shell resin may not proceed when the core particle surface is rich in wax or If the pigment is rich, the chargeability may be affected.

  As a result, the controllability of the shape of the toner particles is deteriorated, and the particle size distribution becomes broad, making it difficult to produce small particle size particles. In addition, a decrease in chargeability tends to cause a decrease in image quality such as omission or fog during transfer.

That is, it is important to form the core particles by adjusting the balance of the aggregation speed of the resin particles, the pigment particles, and the wax particles. However, the means for adjusting the balance of the aggregation speed to aggregate the core particles is not sufficiently disclosed. .
JP-A-57-045558 Japanese Patent Laid-Open No. 10-073955 Japanese Patent Laid-Open No. 11-311877 JP 2002-116574 A

  In the configuration in which the emulsified resin particles, wax particles, and pigment particles are aggregated to form particles, in the toner including the wax having a certain melting point and the yellow pigment, the aggregation rate of the resin particles, pigment particles, and wax particles The core particles are formed by adjusting the balance, and the phenomenon in which the wax and pigment particles are left behind and the liquid is not easily transparent is reduced, thereby enabling formation of particles having a small particle size and a narrow particle size distribution.

  In addition, a core-shell configuration is disclosed in which shell resin particles are fused to the surface of core particles (core particles) to obtain toner particles. A shell resin dispersion in which shell resin particles are dispersed is mixed with a dispersion of core particles. In the method of shelling by heating, when the shell resin particles are fused to the core particles blended with the wax described above, the presence of the wax makes the adhesion of the shell resin particles unstable, and the adhesion progresses easily. In some cases, once the shell resin particles adhere to the core particles, if the wax melts in the subsequent heat treatment step, the shell resin particles may be detached from the core particles due to the releasing action of the wax. The object is to make the progress of adhesion of the shell resin to the surface of the core particle in which the resin particles, wax particles and pigment particles are aggregated sufficiently good.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a toner that can produce a toner having a small particle size having a sharp particle size distribution without a classification step, and a method for producing the toner. It is another object of the present invention to provide a toner and a method for producing the toner that can prevent voids and scattering during transfer and can achieve high transfer efficiency.

  The configuration of the present invention is such that at least a first resin particle dispersion in which first resin particles are dispersed, a colorant particle dispersion in which colorant particles are dispersed, and a wax in which wax particles are dispersed in an aqueous medium. A toner containing core particles produced by mixing and agglomerating a particle dispersion, wherein the colorant is represented by C.I. I. Pigment Yellow 74 azo pigment, the wax contains a wax having an endothermic peak temperature of 50 to 120 ° C. by DSC method, and the main component of the surfactant used in the colorant particle dispersion and the wax particle dispersion is a nonionic interface When the HLB of the nonionic surfactant used in the colorant particle dispersion containing the activator is Yh1, and the HLB of the nonionic surfactant used in the wax particle dispersion is Wh1, the relationship shown in (Equation 1) is obtained. Toner to fill.

  Further, the configuration of the present invention is such that 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 particles are dispersed in the aqueous medium. A step of producing a mixed solution by mixing the wax particle dispersion liquid, and a step of aggregating the first resin particles, the colorant particles and the wax particles with a flocculant in the mixed solution to produce core particles. And the colorant particle dispersion was treated with a surfactant mainly composed of a nonionic surfactant (Chemical Formula 2). I. Pigment Yellow 74 monoazo pigment, and the wax contains a wax having an endothermic peak temperature of 50 to 120 ° C. according to DSC method, which is treated with a surfactant mainly composed of a nonionic surfactant, and the colorant particle dispersion includes This is a method for producing a toner satisfying the relationship expressed by (Equation 2), where Yh1 is the nonionic surfactant used for the HLB and Wh1 is the nonionic surfactant used for the wax particle dispersion.

In a toner configuration including core particles produced by mixing and aggregating each particle dispersion in which resin particles, colorant particles and wax particles are dispersed, C.I. I. Pigment Yellow 74 azo pigment, the wax contains a wax having an endothermic peak temperature of 50 to 120 ° C. by DSC method, and the colorant particle dispersion and the nonionic surfactant used in the wax particle dispersion have a certain relationship. By
The particles are formed by balancing the agglomeration speed of resin particles, pigment particles, and wax particles, and the phenomenon that the wax and pigment particles are left behind and the liquid is not easily transparent is reduced. Can be formed. In addition, in the toner configuration in which the shell resin particles are fused to the surface of the core particles containing wax, the progress of adhesion of the shell resin to the core particle surfaces can be made sufficiently good.

  As a result, an effect can be obtained in durability, charge stabilization, high temperature non-offset property and storage stability.

  In addition, in the tandem color process where image forming stations with multiple photoconductors and development units are arranged side by side and the toner of each color is successively transferred to the transfer body, it is possible to prevent voids and reverse transfer during transfer. In addition, high transfer efficiency can be obtained.

(1) Polymerization and agglomeration step The resin particle dispersion is prepared by subjecting the vinyl monomer to emulsion polymerization or seed polymerization in a surfactant to give a vinyl monomer homopolymer or copolymer ( A dispersion obtained by dispersing resin particles of a vinyl resin) in a 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, Dissolve the resin in the oily solvent, disperse the fine particles in water together with a surfactant and polymer electrolyte using a disperser such as a homogenizer, and then heat or reduce pressure to evaporate the oily solvent. Thus, a dispersion liquid in which resin particles other than the vinyl resin are dispersed in the surfactant is prepared.

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

  The wax particle dispersion is prepared by adding wax particles in water to which a surfactant is added and dispersing the particles using a suitable dispersing means.

  Toners are required to have low-temperature fixing, high-temperature non-offset property in oilless fixing, high translucency of color images, storage stability under a certain high temperature, and high image quality. Don't be.

  The first configuration of the present invention is a resin particle dispersion in which at least first resin particles are dispersed, a colorant particle dispersion in which colorant particles are dispersed, and a wax in which wax particles are dispersed in an aqueous medium. The particle dispersion is mixed and aggregated to produce core particles. This colorant is represented by C.I. I. Pigment Yellow 74 azo pigment, the wax contains a wax having an endothermic peak temperature (referred to as a melting point) by DSC method of 50 to 120 ° C., and the main component of the surfactant used in the colorant particle dispersion and the wax particle dispersion is non-volatile. Assuming that the HLB of the nonionic surfactant used in the colorant particle dispersion is Yh1 and the HLB of the nonionic surfactant used in the wax particle dispersion is Wh1 in a configuration including an ionic surfactant, (Equation 3) It is the structure which satisfies the relationship shown. The configuration is preferably 1.5 or more and 3.5 or less, more preferably 2 or more and 3 or less.

  This is because a nonionic surfactant is used as the surfactant, and the HLB value of the surfactant used in the pigment and wax is specified, so that the balance of the aggregation speed of the pigment particles and the wax particles is adjusted and each particle is adjusted. The object is to form uniformly dispersed particles. It has been found that the balance of the aggregation rate can be adjusted by having a certain relationship between the HLB value of the nonionic surfactant used in relation to the surface property of the yellow pigment and the properties of the wax. If the difference in HLB values is less than 1, the cloudiness does not disappear and the formed particles tend to be larger. If it is larger than 4, yellowing tends to be difficult to disappear.

Here, the HLB value is a value representing the degree of affinity of the surfactant to water and oil (an organic compound insoluble in water).
Particularly, the HLB value (Hydrophile-Lipophile Balance) of the nonionic surfactant is HLB = (MH × 20) / (MH + ML) where ML is the molecular weight of the lipophilic part of the surfactant and MH is the molecular weight of the hydrophilic part. (Griffin method).

  Further, the wax includes a wax having a melting point of 50 to 120 ° C. Preferably it is 50-100 degreeC, More preferably, it is 55-90 degreeC. It seems that the difference in behavior during the agglomeration reaction between wax particles that partially melt during the agglomeration reaction and pigment particles that do not melt during the agglutination reaction has an effect on the appropriate difference in HLB value. When the temperature is lower than 50 ° C., the agglomeration proceeds too quickly, and even if the HLB value is adjusted, the produced core particles tend to be coarse, and the storage stability in a high temperature storage state tends to deteriorate. When the temperature is higher than 120 ° C., the progress of aggregation is difficult to proceed, particle formation is difficult, and low-temperature fixability and color gloss tend not to be improved.

  In the first configuration of the present invention, the nonionic surfactant HLB (Wh1) used in the wax particle dispersion is 14.1-17.6, and the nonionic surfactant HLB (Yh1) used in the pigment particle dispersion. However, the structure which makes it the range of 13.3 to 16.8 is preferable.

  When Wh1 is smaller than 14.1, the agglomeration of wax particles proceeds rapidly, yellow particles are easily left behind, and the generated particles have a broad particle size distribution. When Wh1 is larger than 17.6, the aggregation of the wax particles does not easily proceed, the white turbidity is difficult to disappear, and the generated particles tend to have a broad particle size distribution.

  When Yh1 is less than 13.3, the progress of the aggregation of yellow particles is quick, wax particles are easily left behind, and the generated particles have a broad particle size distribution. When Yh1 is larger than 16.8, the aggregation of the wax particles does not easily proceed, the white turbidity is difficult to disappear, and the generated particles tend to have a broad particle size distribution.

  Preferably, Wh1 is 15.2 to 17.6, Yh1 is 13.3 to 16.8, more preferably Wh1 is 16 to 17.6, and Yh2 is 13.3 to 15.2. preferable.

  In the first configuration of the present invention, the average ethylene oxide addition mole number of the nonionic surfactant for dispersing the yellow pigment particles is Peo1, and the average ethylene oxide addition mole number of the nonionic surfactant for dispersing the wax particles is Weo1. Then, it is the structure which makes the value of Weo1 larger than Peo1. This is because the nonionic surfactant having a smaller average number of moles of ethylene oxide added tends to have higher cohesiveness with respect to the coagulant. Since the cohesiveness is different depending on the relationship between the surface property of the yellow pigment and the properties of the wax, it is considered that the aggregation rate is balanced by providing a difference in the average number of moles of ethylene oxide added.

  The average number of moles of ethylene oxide added to the nonionic surfactant used for dispersing the pigment particles is preferably 10 to 40. More preferably, it is 18-33, More preferably, it is 20-30.

  If the average ethylene oxide addition mole number of the nonionic surfactant is smaller than 10, the aggregation rate of the pigment particles with respect to the aggregating agent is too high (highly aggregating and easy to agglomerate). It grows into particles and is not taken into the toner particles. On the other hand, when the average ethylene oxide addition mole number of the nonionic surfactant is larger than 40, the cohesiveness with respect to the flocculant becomes too low, and the pigment fine particles do not aggregate and exist as particles in the reaction solution. , It is not taken into the toner particles and the liquid remains yellow.

  A configuration in which the nonionic surfactant used for dispersing the pigment particles contains a plurality of nonionic surfactants is also preferable. By itself, even if the average ethylene oxide addition mole number of the nonionic surfactant is not in the range of 10 to 40, the weight average ethylene oxide addition mole number of the plurality of nonionic surfactants should be in the range of 10 to 40. That's fine.

  Here, the aggregating property of each particle with respect to the aggregating agent is evaluated by the concentration of the aggregating agent when the particle dispersion is dripped into an aggregating agent aqueous solution of various concentrations (for example, magnesium sulfate aqueous solution) and the particles aggregate to a certain size. The higher the cohesiveness of the particles to the flocculant, the more the particles will aggregate at a lower flocculant concentration.

  The amount of the nonionic surfactant with respect to the pigment particles is preferably 10 to 20 parts by weight with respect to 100 parts by weight of the yellow pigment from the viewpoint of dispersion stability.

  In the first configuration of the present invention, the surfactant used in the first resin particle dispersion is a mixture of a nonionic surfactant and an ionic surfactant, and the surfactant used in the pigment particle and wax particle dispersion. A configuration in which the main component of the agent is a nonionic surfactant is preferred.

  Of the surfactants used in the first resin particle dispersion, it is preferable that the nonionic surfactant has 50 to 95 wt% with respect to the total surfactant. More preferably, it is 55-90 wt%, More preferably, it is 60-85 wt%. By setting it to 50 wt% or more, the phenomenon that the particle size distribution of the produced core particles is expanded can be suppressed. By setting it to 95 wt% or less, there is an effect of stabilizing the dispersion of the resin particles themselves in the resin particle dispersion. As the ionic surfactant, an anionic surfactant is preferable.

  In the first configuration of the present invention, as one embodiment of core particle formation, a first resin particle dispersion in which first resin particles are dispersed in an aqueous medium, and colorant particles in which colorant particles are dispersed. Mixing the dispersion and the wax particle dispersion in which the wax particles are dispersed, adjusting the pH of the mixed dispersion under a certain condition, and adding a water-soluble inorganic salt, the first resin particles, coloring Core particles in which agent particles and wax particles are aggregated are produced. By heating the aqueous medium above the glass transition temperature (Tg) of the first resin particles and / or above the melting point of the wax, core particles at least partially melted can be generated.

  When a resin particle dispersion uses a persulfate such as potassium persulfate as a polymerization initiator when polymerizing an emulsion polymerization resin, the residue is decomposed by the heat during the heat aggregation process to change the pH ( Heat treatment at a certain temperature or higher (preferably 80 ° C. or higher in order to sufficiently disperse the residue) for a certain time (preferably about 1 to 5 hours) after emulsion polymerization. It is preferable to apply. The pH of the produced resin particle dispersion is preferably 4 or less, more preferably 1.8 or less.

  For the measurement of pH (hydrogen ion concentration), 10 ml of a sample to be measured is collected from the liquid tank using a pipette and placed in a beaker having the same volume. This beaker is immersed in cold water, and the sample is cooled to room temperature (30 ° C. or lower). Using a pH meter (Seven Multi: manufactured by METTLER TOLEDO), immerse the measurement probe in the sample cooled to room temperature. When the meter display is stable, read the value and use it as the pH value.

  After adjusting the pH of the mixed dispersion, the temperature of the mixed dispersion is raised while stirring the liquid. The temperature rising rate is preferably 0.1 to 10 ° C./min. Slow productivity decreases. If it is too early, the shape tends to advance too spherically before the particle surface becomes smooth.

  It is preferable to adjust the pH of the mixed dispersion described above to a range of 9.5 to 12.2. Preferably, the pH is adjusted to 10.5 to 12.2, and more preferably the pH is adjusted to the range of 11.2 to 12.2. The pH can be adjusted by adding 1N NaOH. By setting the pH value to 9.5 or more, there is an effect of suppressing the generation of liberated wax particles and colorant particles and facilitating uniform encapsulation of the wax and colorant. By setting the pH value to 12.2 or less, there is an effect of suppressing the phenomenon that the formed core particles become coarse.

  After adjusting the pH of the mixed dispersion, a water-soluble inorganic salt is added, and heat treatment is performed to form core particles having a predetermined volume average particle diameter at least partially melted and aggregated.

  By maintaining the pH of the liquid in the range of 7 to 10 when the core particles having the predetermined volume average particle diameter are formed, the core particles having a narrow particle size distribution in which the wax is hardly released and the wax is included are obtained. Can be formed. The pH is preferably in the range of 8 to 10, more preferably in the range of 8.4 to 10.

  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 are appropriately selected. When the pH of the liquid when the particles are formed is less than 7, the core particles tend to become coarse. When the pH exceeds 10, the free wax tends to increase due to poor aggregation.

  As a preferred reaction vessel used for emulsion polymerization, mixing, and agglomeration, a glass-lined SUS vessel is not particularly limited as a stirring blade for stirring the dispersion, but a blade shape having a wide width in the depth direction ( A flat blade is effective. As the flat plate wing, Max Blend wing manufactured by Sumitomo Heavy Industries, Ltd., full zone wing manufactured by Shinko Pantech Co., Ltd., etc. are effective.

  FIG. 7 is a schematic diagram showing the configuration of the Max Blend wing, and FIG. 8 is a plan view seen from above. Moreover, the structure of a full zone blade | wing is shown in the schematic in FIG. 9, and the top view seen from the top in FIG. A shaft 301 is connected to a stirring motor (not shown). 302 is a stirring tank, 303 is a water surface of the liquid, 304 is a flat max blend blade, and 305 holes are provided in the blade to adjust the stirring strength of the liquid. Reference numeral 306 denotes a flat rectangular blade, and a stirring blade 307 is provided below the flat rectangular blade. The tip is bent about 130 degrees. Reference numeral 308 denotes the length of the stirring blade.

  The rotational speed of the stirring blade varies depending on the particle concentration in the dispersion and the target particle size, but is preferably 0.5 to 2.0 m / s. More preferably, it is 0.7-1.8 m / s, More preferably, it is 1.0-1.6 m / s. If the speed is too low, the particle size of the generated particles tends to be large and the particle size distribution tends to be widened. If the speed is too high, the aggregation of particles is hindered, the shape tends to be indefinite, and the generation of particles becomes difficult.

  In the toner production method of the present invention, as a preferred embodiment of core particle generation, the first resin particle dispersion, the colorant particle dispersion, and the wax particle dispersion are mixed in an aqueous medium to obtain a mixed dispersion. Generate. It is also preferable to heat the mixed dispersion and add a water-soluble inorganic salt as a flocculant to the mixed dispersion after the liquid temperature of the mixed dispersion reaches a certain temperature.

  By adding the flocculant when the temperature of the mixed dispersion reaches a certain level or more, the phenomenon in which the agglomeration occurs slowly with the temperature rise time is avoided, and the agglomeration reaction proceeds at once with the addition of the flocculant, and in a short time. Core particles can be generated. Further, it is possible to form core particles having a small particle size distribution and a narrow particle size distribution in which wax and colorant are uniformly incorporated.

  Furthermore, as described later, when waxes having different melting points are used in combination, in the process of raising the temperature, the low melting point wax is first melted, and when the temperature rises, then the higher melting point is reached. This is an effective method for preventing the formation of agglomerates of low melting point wax particles or high melting point particle waxes. It is possible to prevent the wax from being unevenly distributed in the core particles, thereby preventing the particle size distribution of the core particles from becoming wide and the shape distribution from becoming non-uniform. By using the yellow pigment particle dispersion and wax particle dispersion treated with the surfactant having the specific HLB value described above, the particles produced by aggregation can be made to have a small particle size and a narrow particle size distribution.

  As the flocculant to be added, an aqueous solution containing a water-soluble inorganic salt having a constant water concentration is used. After adjusting the pH value of the aqueous solution, at least the first resin particles are dispersed. It is also preferable that the liquid, the colorant particle dispersion in which the colorant particles are dispersed, and the wax dispersion in which the wax particles are dispersed are added to the mixed dispersion.

  It is considered that the aggregating action of the particles as the aggregating agent can be further enhanced by adjusting the pH value of the aqueous solution containing the aggregating agent to a constant value. It is preferable to have a certain relationship with the pH value of the mixed dispersion, and adding an aqueous flocculant solution with a different pH value to the mixed dispersion suddenly disturbs the pH balance of the liquid, so the aggregated particles are coarse. Or wax dispersion tends to be non-uniform. In order to suppress such a phenomenon, it is effective to adjust the pH of the flocculant aqueous solution.

  When the mixed dispersion obtained by mixing the first resin particle dispersion, the colorant particle dispersion, and the wax particle dispersion is heat-treated, and the pH value of the mixed dispersion before the addition of the aqueous solution containing the flocculant is HG, aggregation occurs. The pH value of the aqueous solution containing the agent is preferably adjusted and added in the range of HG + 2 to HG-4. The range is preferably HG + 2 to HG-3, more preferably HG + 1.5 to HG-2, and still more preferably HG + 1 to HG-2.

  When an aqueous flocculant solution having a different pH value is added to the mixed dispersion, the pH balance of the liquid is abruptly disturbed, so that the agglomeration reaction is difficult to proceed with delay, and the aggregated particles tend to be coarse. In order to suppress such a phenomenon, it is effective to adjust the pH of the flocculant aqueous solution. Although the cause is unknown, a configuration in which the pH value of the aqueous solution containing the flocculant is lower than the pH value of the mixed dispersion is more preferable.

  By setting it as HG-4 or more, the aggregating action of the particles as the aggregating agent can be further enhanced, and the agglutination reaction can be accelerated. By setting it to HG + 2 or less, there is an effect of suppressing the phenomenon that the aggregated particles become coarse or the particle size distribution becomes broad.

  The timing of adding the flocculant is the melting point of the wax measured by the DSC method described later, in which the temperature of the mixed dispersion obtained by mixing the first resin particle dispersion, the colorant particle dispersion, and the wax particle dispersion is mixed. A configuration in which a flocculant is added after reaching the above is preferable. By adding a flocculant in the state where the wax has started to melt, the agglomeration of the wax particles to be melted, the resin particles and the colorant particles proceeds all at once. It seems that melting progresses and particles are formed.

  At this time, even when the flocculant is added when the temperature of the mixed dispersion reaches the glass transition point of the first resin particles, the particles hardly aggregate and no particles are formed. When the temperature of the mixed dispersion reaches the specific temperature of the wax, the aggregation of the particles proceeds by adding a flocculant, and then 0.5 to 5 hours, preferably 0.5 to 3 hours, more preferably 1 Heat treatment for ˜2 hours produces core particles with a predetermined particle size distribution. The heat treatment may be performed while keeping the specific temperature of the wax, but it is preferably 80 to 95 ° C, more preferably 90 to 95 ° C. Aggregation reaction can be accelerated, leading to reduction of processing time.

  Furthermore, as described later, when two or more kinds of wax are included, it is preferable to adjust the specific temperature of the wax having the lower melting point. More preferably, the specific temperature of the wax having the higher melting point is adjusted. It is effective to add the flocculant in a temperature state where the melting of the wax particles is started.

  The flocculant may be added all at once, but it is also preferable to add the flocculant dropwise over a period of 1 to 120 minutes. Although it may be divided, continuous dripping is preferred. By dropping the flocculant at a constant rate into the heated mixed dispersion, the flocculant gradually and uniformly mixes with the entire mixed dispersion in the reaction kettle, and the uneven distribution makes the particle size distribution broad. It has the effect of suppressing the generation of suspended particles of wax and colorant. Moreover, the rapid fall of the liquid temperature of a mixed dispersion liquid can be suppressed. Preferably it is 5-60 min, More preferably, it is 10-40 min, More preferably, it is 15-35 min. For 1 min or longer, the shape of the core particles does not proceed to an indefinite shape, and a stable shape is obtained. By setting it to 120 min or less, the effect of suppressing the presence of particles floating alone due to poor aggregation of the colorant and wax particles can be obtained.

  A configuration in which 1 to 50 parts by weight of the flocculant is dropped with respect to 100 parts by weight of the total of the first resin particles, pigment fine particles, and wax fine particles is preferable. Preferably it is 1-20 weight part, More preferably, it is 5-15 weight part, More preferably, it is 5-10 weight part. When the amount is too small, the agglutination reaction does not proceed.

  In addition to the first resin particle dispersion, the colorant particle dispersion, and the wax particle dispersion, ion-exchanged water may be added to the mixed dispersion in order to adjust the solid concentration in the liquid. The solid concentration in the liquid is preferably 5 to 40 wt%.

  Further, as the flocculant, it is also preferable to use a water-soluble inorganic salt adjusted to a constant concentration with ion exchange water or the like. The concentration of the flocculant aqueous solution is preferably 5 to 50 wt%.

  In the structure of the toner of the present invention, the second resin particle dispersion in which the second resin particles are dispersed is added to and mixed with the core particle dispersion in which the core particles are dispersed, and the heat treatment is performed on the core particles. The toner particles are fused to the core particles to produce toner base particles.

  Forming a fusion layer (sometimes referred to as a shell layer) on the core particles of the second resin particles is desirable from the viewpoint of charging stability. In addition, since particles having different softening points or melting points of the resin and the wax are present in the core particle, there may be irregularities on the surface of the particle. Therefore, it is effective to provide a shell layer.

  In addition, from the viewpoint of enhancing the storage stability of the toner at a high temperature, resin particles having a high glass transition point (Tg (° C.)) are used. From the viewpoint of ensuring high temperature offset resistance during fixing, high molecular weight resin particles are used. It is desirable to form as a shell layer.

  In the configuration in which the second resin particles are fused to the core particles, the second resin particle dispersion in which the second resin particles whose pH value is adjusted to an alkaline state is dispersed is set to a pH value of 7 to 10. It is preferable to add to the core particle dispersion in which the core particles in the range state are dispersed.

  A configuration in which the pH value of the second resin particle dispersion in which the second resin particles adjusted to an alkaline state are dispersed is preferably in the range of 7.5 to 10.5. Preferably it is 8.5-10.5, More preferably, it is 8.9-10.5.

  The pH value of the second resin particle dispersion liquid in which the second resin particles are dispersed is higher than the pH value of the core particle dispersion liquid in which the core particles are dispersed, that is, adjusted to be more alkaline and added. It is preferable that The pH value of the second resin particle dispersion in which the second resin particles are dispersed is preferably 0.5 or more higher than the pH value of the core particle dispersion in which the core particles are dispersed. More preferably, it is 1 or more. When it is smaller than 0.5, there is a tendency that the generation of floating second resin particles that do not participate in fusion increases. On the other hand, if the difference exceeds 3.5, the second resin particles that float and do not participate in fusion are generated, and secondary agglomeration between core particles occurs, and the generated particles tend to be coarse. .

  By maintaining a certain relationship between the pH value of the second resin particle dispersion and the pH value of the core particle dispersion and adding the second resin particle dispersion, the second resin to the core particles is added. The aim is to promote the adhesion of particles, suppress the generation of floating second resin particles that do not participate in fusion, and further suppress the occurrence of secondary aggregation between core particles.

  Even when the pH value of the second resin particle dispersion in which the second resin particles are dispersed is lower than the pH value of the core particle dispersion in which the core particles are dispersed, the generation of the second resin particles is increased. The liquid continues to be cloudy.

  The pH value of the core particle dispersion is in the range of 7 to 10, and the pH value of the second resin particle dispersion is adjusted to 7.5 to 10.5, and then added to the second to the core particles. It is possible to promote the adhesion of resin particles, suppress the generation of floating second resin particles that do not participate in fusion, suppress the occurrence of secondary aggregation between core particles, and form a narrow particle size distribution with a small particle size It becomes possible.

  When the pH value of the core particle dispersion is less than 7 and the pH value of the second resin particle dispersion is less than 7.5, the adhesion of the second resin particles to the core particles does not proceed, and the second Resin particles tend to remain floating without being fused to the core particles. When the pH value of the core particle dispersion liquid is larger than 10 and the pH value of the second resin particle dispersion liquid is larger than 10.5, the second resin particles are not adhered to the core particles and generated. Particles tend to be coarsened.

  The pH value can be adjusted by adding sodium hydroxide or hydrochloric acid solution.

  In the configuration in which the second resin particles are fused to the core particles, the amount of the generated core particles is 100 parts by weight as a dropping condition of the second resin particle dispersion in the core particle dispersion in which the generated core particles are dispersed. On the other hand, a structure in which the dropping rate of the second resin particles is generated by dropping under a dropping condition of 0.14 parts by weight / min to 2 parts by weight / min is preferable.

  Preferably it is 0.15 weight part / min-1 weight part / min, More preferably, it is 0.2 weight part / min-0.8 weight part / min.

  The second resin particle dispersion is added as it is when the core particles reach a predetermined particle size. The addition is preferably performed by dropping sequentially. When the predetermined total amount is added all at once or exceeds 2 parts by weight / min, only the second resin particles tend to aggregate and the particle size distribution tends to be broad. In addition, when the input amount increases, the temperature of the liquid rapidly decreases and the agglomeration reaction stops, and a part of the second resin particles are suspended in the aqueous system without being attached to the core particles. It may remain.

  On the other hand, if the amount is less than 0.14 parts by weight / min, the amount of the second resin particles adhering to the core particles is reduced, and when the heating is continued, the core particles are aggregated. , The particles are coarse and the particle size distribution tends to be broad.

  By optimizing the dropping conditions of the second resin particle dispersion, it is possible to prevent the aggregation of the core particles and the aggregation of only the second resin particles, and to generate particles having a small particle size and a narrow particle size distribution. To do.

  A configuration in which the second resin particle dispersion is dropped is preferable so that the fluctuation of the liquid temperature of the core particle dispersion in which the produced core particles are dispersed is suppressed to within 10%.

  Further, after the second resin particles are attached to the surface of the core particles, the pH in the aqueous system is further adjusted to the range of 3.2 to 6.8, and then the temperature equal to or higher than the glass transition temperature of the second resin particles. It is also preferable to adopt a method of heat treatment for 0.5 to 5 hours. By setting the pH within this range, it is possible to further promote the surface smoothness of the particle shape while suppressing secondary aggregation between the core particles.

  In order to improve the durability, storage stability, and high temperature non-offset property of the toner, the thickness of the resin layer fused with the second resin particles is preferably 0.5 μm to 2 μm. If it is thinner than this, the effects of storage stability and high-temperature non-offset property cannot be exhibited, and if it is thicker, the low-temperature fixability is hindered.

  In the constitution of the toner of the present invention, the first resin particles are obtained by emulsion polymerization of a monomer using a polymerization initiator in an aqueous medium, and the addition amount of the polymerization initiator is a single amount. 0.5 to 2.5 parts by weight per 100 parts by weight of the body, the polymerization initiator is a persulfate having a solubility of 4 g or more in 100 g of water at a water temperature of 20 ° C., and the monomer is a styrenic monomer ( Including the (meth) acrylate monomer and the vinyl monomer having an acid group, the compounding amount of the vinyl compound having an acid group is 0.1 to 5.0% by weight in the monomer. Is preferred. By using the yellow pigment particle dispersion and wax particle dispersion treated with the surfactant having the specific HLB value described above, it is more effective to make the particles produced by agglomeration have a small particle size and a narrow particle size distribution. Is.

  About the addition amount of a polymerization initiator, it exists in the tendency which influences aggregation of a 1st resin particle, a colorant particle, and a wax particle by the abundance of the hydrophilic group derived from a polymerization initiator. That is, when the amount of polymerization initiator added is large, the agglomeration reaction tends to proceed slowly, and when the amount of polymerization initiator added is small, the agglomeration reaction tends to proceed quickly, and the appropriate amount of polymerization initiator added is appropriate. , 0.5 to 2.5 parts by weight per 100 parts by weight of the monomer. Preferably, it is 0.7-2.0 weight part, More preferably, it is 1.0-1.5 weight part. The first resin particles, the third resin particles, the colorant particles, and the wax particles are within a range in which the aggregation is appropriate.

  When the amount is less than 0.5 parts by weight, the aggregation of the first resin particles proceeds quickly, and the core particles that aggregate with the wax and the pigment are not generated, but the coarse particles of the resin in which the first resin particles aggregate are generated. Will be.

  When the amount is more than 2.5 parts by weight, the aggregation of the core particles tends to be delayed and time is required for productivity. Further, the high temperature non-offset property deteriorates, resulting in a narrow fixing temperature range. This is thought to affect the dispersibility of the wax because the agglutination reaction proceeds slowly due to the amount of hydrophilic groups derived from the polymerization initiator, but the details are not fully understood.

  The polymerization initiator is preferably a persulfate having a solubility of 4 g or more in 100 g of water having a water temperature of 20 ° C. The cohesiveness and fixability of the core particles can be made appropriate by optimizing the amount of hydrophilic groups derived from the polymerization initiator. If the solubility is low, it takes time to dissolve the persulfates during the emulsion polymerization reaction, and the productivity is slowed down. The dispersion state of persulfates during emulsification tends to change, and the agglomeration during the agglomeration reaction may become unstable.

  It is preferable that the compounding quantity of the vinyl compound which has an acid group is 0.1 to 5.0 weight% in a monomer. Preferably, it is 0.2 to 4.5% by weight, more preferably 0.5 to 2.0% by weight. This is a range in which the first resin particles, the third resin particles, the colorant particles, and the wax particles can be properly aggregated.

  If the amount is less than 0.1% by weight, the aggregation of the first resin particles is accelerated, and the core particles are not aggregated with the wax and the pigment. The particles tend to be coarse.

  When the amount is more than 5.0% by weight, the aggregation of the core particles tends to be delayed. This is because the aggregation reaction proceeds slowly due to the presence of the hydrophilic group derived from the acid group. It is thought that it affects the agglomeration, thereby changing the dispersion state of the wax, deteriorating the high temperature non-offset property and narrowing the fixable temperature range, but details are not fully understood.

  After the colored particles are formed, toner base particles can be obtained through an arbitrary 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.

  As the polymerization initiator, persulfates such as potassium persulfate, ammonium persulfate, sodium persulfate and the like are preferable materials.

  As the flocculant, a water-soluble inorganic salt is selected, and examples thereof 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. It is also preferable to use it after adjusting to a constant concentration with ion-exchanged water or the like.

  Examples of nonionic surfactants include higher alcohol ethylene oxide adducts, alkylphenol ethylene oxide adducts, fatty acid ethylene oxide adducts, polyhydric alcohol fatty acid ester ethylene oxide adducts, fatty acid amide ethylene oxide adducts, and fats and ethylene oxides. Adduct, Polyethylene glycol type nonionic surfactant such as polypropylene glycol ethylene oxide adduct, fatty acid ester of glycerol, fatty acid ester of pentaerythritol, fatty acid ester of sorbitol and sorbitan, fatty acid ester of sucrose, alkyl of other alcohol And polyhydric alcohol type nonionic surfactants such as ethers and fatty acid amides of alkanolamines.

  Polyethylene glycol type nonionic surfactants such as higher alcohol ethylene oxide adducts and alkylphenol ethylene oxide adducts can be particularly preferably used.

  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.

  In the case where a nonionic surfactant and an ionic surfactant are used in combination, examples of the polar surfactant include anions such as sulfate ester, sulfonate, phosphate, and soap. Surfactant, amine surfactant type, quaternary ammonium salt type cationic surfactant and the like.

  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.
(2) Resin Examples of the resin particles of the present invention include thermoplastic binder resins. 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 and 2-ethylhexyl methacrylate, carboxyl groups of acid groups such as acrylic acid, methacrylic acid, maleic acid and fumaric acid Homopolymers such as unsaturated polyvalent carboxylic acid monomers having a dissociation group, copolymers obtained by combining two or more of these monomers, or mixtures thereof.

  The solid content of the resin particles in the resin particle dispersion is usually 5 to 50% by weight, preferably 10 to 40% by weight.

  A configuration in which the softening point (Tmr1) of the first resin particles constituting the core particles is 80 ° C. to 130 ° C. is preferable. Preferably they are 80 to 125 degreeC, More preferably, they are 80 to 120 degreeC, More preferably, they are 85 to 110 degreeC.

  When the softening point is lower than 80 ° C., the progress of agglomeration is rapid, and it tends to be difficult to form particles with a small particle size and a narrow particle size distribution. In addition, the shape is close to a true sphere, and it tends to be difficult to control the shape. When the softening point is higher than 130 ° C., the low-temperature fixability tends to deteriorate.

  Moreover, the structure whose glass transition point of the 1st resin particle which comprises a core particle is 45 to 60 degreeC is preferable. More preferably, it is 45 degreeC-55 degreeC, More preferably, it is 45 degreeC-52 degreeC. When the glass transition point of the resin particles is lower than 45 ° C., the core particles are coarsened, and the storage stability and heat resistance tend to decrease. If it is higher than 60 ° C., the low-temperature fixability tends to deteriorate.

  Moreover, as a preferable structure of the first resin particles, the weight average molecular weight (Mwr1) is 10,000 to 60,000, and the ratio Mwr1 / Mnr1 of the weight average molecular weight (Mwr1) to the number average molecular weight (Mnr1) is 1.5 to 6. Some configurations are preferred. It is preferable that the weight average molecular weight (Mwr1) is 10,000 to 50,000 and the ratio Mwr1 / Mnr1 of the weight average molecular weight (Mwr1) to the number average molecular weight (Mnr1) is 1.5 to 3.9. More preferably, the weight average molecular weight (Mw1r) is 10,000 to 30,000, and the ratio Mw1r / Mnr1 of the weight average molecular weight (Mwr1) to the number average molecular weight (Mn1r) is preferably 1.5 to 3. The resin particles are preferably 60% by weight or more, more preferably 70% by weight or more, and still more preferably 80% by weight or more based on the total toner resin.

  When Mwr1 is less than 10,000, the core particles are coarsened, and the storage stability and heat resistance tend to decrease. If it exceeds 60,000, the low-temperature fixability tends to deteriorate. When Mwr1 / Mnr1 is larger than 6, the shape of the core particles is not stable, tends to be indeterminate, and irregularities remain on the particle surface, which tends to be inferior in surface smoothness.

  As described above, the first resin particles are desired to have a structure that lowers the softening point or molecular weight as much as possible in order to improve the low-temperature fixability. It tends to be difficult to remove. Therefore, it is possible to achieve both low-temperature fixing and shape control by blending resin particles having a certain thermal property relationship with the first resin particles having a low softening point or low molecular weight.

  Moreover, as a structure of 2nd resin particle, a glass transition point is 55 to 75 degreeC, a softening point is 140 to 180 degreeC, and the weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) is 5. The structure whose ratio Mw / Mn of 10,000 to 500,000 and a weight average molecular weight (Mw) and a number average molecular weight (Mn) is 2-10 is preferable. More preferably, the glass transition point is 60 ° C to 70 ° C, the softening point is 145 ° C to 180 ° C, the Mw is 80,000 to 500,000, and the Mw / Mn is 2 to 7. More preferably, the glass transition point is 65 ° C to 70 ° C, the softening point is 150 ° C to 180 ° C, Mw is 120,000 to 500,000, and Mw / Mn is 2 to 5. By making Mw / Mn small and making the molecular weight distribution close to monodisperse, it is possible to uniformly heat-bond the second resin particles to the surface of the core particles. The aim is to improve the durability, high-temperature offset resistance, and separability by promoting thermal fusion of the core particle surfaces and increasing the softening point.

  If the glass transition point of the second resin particles is lower than 55 ° C., secondary aggregation in which aggregation of core particles proceeds tends to occur. In addition, the storage stability tends to deteriorate. When the temperature is higher than 75 ° C., the heat fusion property to the surface of the core particle is deteriorated, and the uniform adhesion tends to be lowered.

  If the softening point of the second resin particles is lower than 140 ° C., durability, high-temperature offset resistance, and separation between paper and the fixing roller tend to be lowered. When it is higher than 180 ° C., glossiness and translucency tend to be lowered.

  When Mw of the second resin particles is smaller than 50,000, durability, high temperature non-offset property, and paper separation property tend to be lowered. If it exceeds 500,000, the low-temperature fixability, glossiness, and translucency tend to decrease.

  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 HLC8120GPC series manufactured by Tosoh Corporation, the column is TSKgel superHM-H H4000 / H3000 / H2000 (6.0 mm ID-150 mm × 3), eluent THF (tetrahydrofuran), flow rate 0.6 mL / min, sample concentration 0 .1% by weight, injection amount 20 μL, detector RI, measurement temperature 40 ° C., pre-measurement treatment was performed by dissolving the sample in THF and leaving it to stand overnight, followed by filtration with a 0.45 μm membrane filter. The resin component from which the additive was removed was measured. 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 9.8 × 10 ⁵ with a plunger while heating a sample of 1 cm ^{3 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 N / m ² and extruding from a die with a diameter of 1 mm and a length of 1 mm, the piston stroke is The temperature at which the sample starts to flow and the sample flows out is defined as the outflow start temperature (Tfb). As the temperature rises, the sample passes from the solid region to the transition region and the rubbery elastic region to the flow region. As for the melting temperature (softening point Tmr ° C.) in the 1/2 method, 1/2 of the difference between the outflow end point (Smax) and the minimum value (Smin) is obtained in relation to the temperature rise temperature and the piston stroke characteristic curve ( X = (Smax−Smin) / 2), which is the temperature at the position of point A plus X and the minimum value Smin of the curve, that is, the melting temperature in the 1/2 method (softening point Tmr ° C.).

  FIG. 11 shows calculation of the melting temperature in the 1/2 method. The temperature rise is plotted on the horizontal axis and the piston stroke is plotted on the vertical axis, and a curve is shown while the sample reaches from the solid region to the transition region, the rubber-like elastic region and the flow region as the temperature rises.

  The glass transition point of the resin was raised to 100 ° C. using a differential scanning calorimeter (Shimadzu DSC-50), 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 sample was heated at a heating rate of 10 ° C / min and the thermal history was measured, the maximum slope between the base line extension below the glass transition point and the peak rising portion to the peak apex was obtained. Says the temperature of the intersection with the indicated tangent.

In measuring the thermal properties of these resins, it is necessary to extract the solid content of the resin particles from the emulsion obtained by emulsion polymerization. As a method for extracting the solid content of the resin particles from the emulsion, a configuration in accordance with the toner aggregation step is performed. First, 2 ml of 1N NaOH is added to 20 g of the emulsion, 6 g of magnesium sulfate and 20 g of ion-exchanged water are added, and then the temperature is raised to 85 ° C. and heated for 1 hour. Thereafter, the mixture is cooled, 0.5 ml of 1N HCl is added, filtered, the precipitated sample is dried, and the molecular weight, softening point, glass transition point, etc. of the obtained polymer are measured.
(3) Wax In oilless fixing without using oil in the fixing roller, low temperature fixing property, high temperature non-offset property, or improvement in separation property of the transfer medium such as a copy sheet on which the toner melted at the time of fixing is mounted. For this reason, it is preferable to add a wax in order to expand the margin of the fixing characteristics that contradict each other in terms of low-temperature fixing, high-temperature offset resistance, and storage stability at high temperatures, and to improve the functionality. Furthermore, a configuration in which a plurality of waxes are added is preferable. By using waxes having different melting points, the functions of the waxes can be separated to achieve both low temperature fixing and high temperature offset resistance and to obtain a wide fixing temperature range characteristic. .

  The relationship between the surface properties of the yellow pigment and the properties of the wax, the difference in behavior during the agglomeration reaction between the wax particles that partially melt during the agglomeration reaction and the pigment particles that do not melt, and the addition of multiple waxes with different melting points Therefore, the use of the yellow pigment particle dispersion and the wax particle dispersion treated with the surfactant having the specific HLB value described above is more effective for making the particles produced by agglomeration have a small particle size and a narrow particle size distribution. It becomes the target. That is, even when waxes having different melting points are used, aggregates of low melting point wax particles and high melting point particle waxes are generated in an aqueous medium, and the dispersion state in which the wax is unevenly distributed in the core particles is suppressed, The object is to alleviate the residual pigment particles and wax particles that do not participate in the aggregation in the core particle dispersion.

  In the first configuration of the present invention, the wax includes at least a wax, and the wax includes a wax having a melting point of 50 to 120 ° C. Preferably it is 50-100 degreeC, More preferably, it is 55-90 degreeC.

  In the first configuration of the present invention, as a preferred embodiment of the wax, a configuration in which a plurality of waxes are added is preferable. As a preferred first configuration, the wax contains at least the first wax and the second wax, and the endothermic peak temperature (referred to as the melting point Tmw1 (° C.)) of the first wax by the DSC method is 50 to 90 ° C. And the structure which makes the endothermic peak temperature (melting | fusing point Tmw2 (degreeC)) by DSC method of a 2nd wax 80-120 degreeC is preferable. Tmw1 is preferably 55 to 85 ° C, more preferably 58 to 85 ° C, and still more preferably 68 to 74 ° C. Tmw2 is more preferably 85 to 100 ° C, further preferably 90 to 100 ° C.

  When Tmw1 is smaller than 50 ° C., the produced core particles are likely to be coarsened. Moreover, storage stability deteriorates. When it is higher than 90 ° C., the low-temperature fixability and color glossiness are not improved. When Tmw2 is smaller than 80 ° C., the high temperature non-offset property and the paper separation property are weakened. When it exceeds 120 ° C., the cohesiveness of the wax decreases, and free particles that do not aggregate in the aqueous system increase. The shape tends to be non-uniform.

  In an embodiment in which a plurality of waxes are used, a preferred second configuration is a configuration in which the wax includes at least a first wax and a second wax, and the first wax has a high carbon number of 16 to 24. It is preferable to include an ester wax composed of at least one of alcohol and a higher fatty acid having 16 to 24 carbon atoms, and the second wax includes an aliphatic hydrocarbon wax.

  In an embodiment using a plurality of waxes, as a preferred third configuration, the wax includes at least a first wax and a second wax, and the first wax has an iodine value of 25 or less and a saponification value of 30. It is preferable that the second wax contains an aliphatic hydrocarbon wax.

  In the second configuration and the third configuration preferable as the wax, the endothermic peak temperature (melting point Tmw1 (° C.)) of the first wax by DSC method is 50 to 90 ° C., 55 to 85 ° C., more preferably 58 to It is 85 degreeC, More preferably, it is 68-74 degreeC. When the temperature is lower than 50 ° C., the storage stability and heat resistance of the toner deteriorate. When it exceeds 90 ° C., the cohesiveness of the wax decreases, and free particles that do not aggregate in the aqueous system increase. Also, low temperature fixability and glossiness are not improved. Further, the endothermic peak temperature (melting point Tmw2 (° C.)) of the second wax by DSC method is 80 to 120 ° C., preferably 85 to 100 ° C., more preferably 90 to 100 ° C. When the temperature is lower than 80 ° C., the storage stability is deteriorated, and the high temperature non-offset property and the paper separation property are weakened. When it exceeds 120 ° C., the cohesiveness of the wax decreases, and free particles that do not aggregate in the aqueous system increase. In addition, low-temperature fixability and color translucency are hindered.

  In the second or third configuration preferable as the wax, when the core particles are formed together with the resin, the colorant and the aliphatic hydrocarbon wax in the aqueous system, the aliphatic hydrocarbon wax is used as a resin because of its compatibility with the resin. The agglomeration tends to hardly occur, and the presence of particles floating without the wax being taken into the core particles, or the aggregation of the core particles does not progress, and the particle size distribution tends to be broad.

  Further, if the temperature and time of the heat treatment are changed in order to suppress the suspended particles and prevent the particle size distribution from becoming broad, the particle diameter becomes coarse. In addition, when the shell is formed, a phenomenon that the core particles are rapidly coarsened occurs.

  Therefore, by using a wax composed of the second wax containing the specific aliphatic hydrocarbon wax and the first wax containing the specific wax as the wax, the aliphatic hydrocarbon wax becomes the core. The presence of particles floating without being taken into the particles can be suppressed, the particle size distribution of the core particles can be prevented from becoming broad, and the phenomenon that the core particles can be rapidly coarsened when shelled can be suppressed. .

  During the heat aggregation, the first wax is compatibilized with the resin, so that the aggregation with the aliphatic hydrocarbon wax resin is promoted and uniformly incorporated, and the generation of suspended particles can be prevented. I think that the. Furthermore, the first wax tends to be improved in low-temperature fixability due to partial progress of compatibilization with the resin. Since the aliphatic hydrocarbon wax does not progress in compatibilization with the resin, this wax can exhibit a function of improving the high temperature offset property and the separation property from paper. That is, the first wax has a function as a dispersion aid during the emulsification dispersion treatment of the aliphatic hydrocarbon wax, and further has a function as a low-temperature fixing aid.

  In the second or third configuration preferable as the wax to which a plurality of waxes are added, as described in the preferable first configuration, in the first configuration preferable as the wax, the wax having a different melting point is colored with resin in the aqueous system. When the toner particles are formed by agglomerating with the agent, the wax is uniformly taken into the toner to form particles having a small particle size and a narrow particle size distribution, and the second resin is melt-adhered to the core particles. In order to further promote the formation of the wax particles, the first wax and the second wax are not separately produced in the production of the wax particle dispersion, but the first wax and the second wax are mixed, emulsified and dispersed, and co-dispersed. It is preferable. In this method, the first wax and the second wax are heated and emulsified and dispersed in the emulsifying and dispersing apparatus at a constant blending ratio. The charging may be performed separately or simultaneously, but it is preferable that the final dispersion liquid contains the first wax and the second wax in a mixed state.

  Further, in the first, second, or third configuration preferable as a wax, when the weight ratio of the first wax to 100 parts by weight of the wax in the wax particle dispersion is ES1, and the weight ratio of the second wax is FT2, FT2 / ES1 is preferably 0.2 to 10. More preferably, it is 1-9, More preferably, it is the range of 1.5-3. If it is less than 0.2, that is, if the weight ratio of the first wax is too large, the effect of high temperature non-offset property cannot be obtained, and the storage stability tends to deteriorate. If it is larger than 10, that is, if the weight ratio of the second wax is too large, low-temperature fixing cannot be realized, and the above-mentioned core particles tend to be coarse. Further, setting the blending ratio of FT2 to 1.5 times or more and 3 times or less of ES1 is a well-balanced ratio capable of satisfying both low temperature fixing property, high temperature storage stability and fixing high temperature non-offset property.

  In addition, in the first, second or third constitution preferable as the wax, the dispersion stability is improved by treating the wax, particularly the aliphatic hydrocarbon wax with an anionic surfactant, but the core particles are aggregated. The core particles are coarse and it is difficult to obtain particles with a sharp particle size distribution.

  Therefore, it is preferable that the wax particle dispersion is prepared by mixing, emulsifying and dispersing the first wax and the second wax with a surfactant mainly composed of a nonionic surfactant. By mixing and dispersing with a surfactant mainly composed of a nonionic surfactant to prepare an emulsified dispersion, aggregation of the wax itself is suppressed and dispersion stability is improved. In the production of aggregated particles of these waxes with a resin and a colorant dispersion, core particles having a small particle size and a narrow particle size distribution can be formed without releasing the wax.

  In the first, second or third configuration preferable as the wax, the total amount of added wax is preferably 5 to 30 parts by weight with respect to 100 parts by weight of the binder resin. Preferably it is 8-25 weight part, More preferably, 10-20 weight part is preferable. When the amount is less than 5 parts by weight, the effects of low temperature fixing property, high temperature non-offset property and paper separation property are not exhibited. If the amount exceeds 30 parts by weight, it is difficult to control particles having a small particle size.

  In the first, second, or third configuration preferable as the wax, a configuration in which Tmw2 is higher than Tmw1 by 5 ° C. or more and 50 ° C. or less is preferable. More preferably, the temperature is 10 ° C. or higher, 40 ° C. or lower, more preferably 15 ° C. or higher, and 35 ° C. or lower. The functions of a plurality of waxes can be efficiently separated, and there is an effect of achieving both low-temperature fixing properties, high-temperature non-offset properties, and paper separation properties. When the temperature is lower than 5 ° C., it is difficult to achieve the effects of achieving both low-temperature fixability, high-temperature non-offset property, and paper separation failure. When the temperature is higher than 50 ° C., the first wax and the second wax are phase-separated and cannot be uniformly taken into the toner particles.

  The preferred first wax comprises at least one ester composed of at least one of a higher alcohol having 16 to 24 carbon atoms and a higher fatty acid having 16 to 24 carbon atoms. By using this wax, it is possible to suppress the presence of particles that are not incorporated into the core particles and the aliphatic hydrocarbon wax to float, to suppress the particle size distribution of the core particles from being broadened, and to form a shell. In addition, it is possible to alleviate the phenomenon that the core particles are coarsened rapidly. Moreover, low temperature fixing can be promoted. The combined use with the second wax prevents high-temperature non-offset property and paper separability as well as coarsening of the particle size, and enables generation of core particles having a small particle size and a narrow particle size distribution.

  As alcohol components, in addition to monoalcohols such as methyl, ethyl, propyl or butyl, glycols such as ethylene glycol or propylene glycol or multimers thereof, triols such as glycerin or multimers thereof, and polyhydric alcohols such as pentaerythritol Sorbitan or cholesterol is preferred. When the alcohol component is a polyhydric alcohol, the higher fatty acid may be a mono-substituted product or a poly-substituted product.

Specifically, esters comprising a higher alcohol having 16 to 24 carbon atoms and a higher fatty acid having 16 to 24 carbon atoms, such as stearyl stearate, palmityl palmitate, behenyl behenate or stearyl montanate,
Esters comprising a higher fatty acid having 16 to 24 carbon atoms such as butyl stearate, isobutyl behenate, propyl montanate or 2-ethylhexyl oleate and a lower monoalcohol,
Montanic acid monoethylene glycol ester, ethylene glycol distearate, monostearic acid glyceride, monobehenic acid glyceride, tripalmitic acid glyceride, pentaerythritol monobehenate, pentaerythritol dilinoleate, pentaerythritol trioleate or pentaerythritol tetrastearate, etc. Esters comprising a higher fatty acid having 16 to 24 carbon atoms and a polyhydric alcohol, or
Higher fatty acids having 16 to 24 carbon atoms and polyhydric alcohols such as diethylene glycol monobehenate, diethylene glycol dibehenate, dipropylene glycol monostearate, distearic diglyceride, tetrastearic acid triglyceride, hexabehenic acid tetraglyceride or decastearic acid decaglyceride Preferable examples include esters composed of multimers. These waxes may be used alone or in combination of two or more.

  When the alcohol component and / or the acid component has less than 16 carbon atoms, the function as a dispersion aid is hardly exhibited, and when it exceeds 24, the function as a low-temperature fixing aid is hardly exhibited.

  Further, the preferred first wax composition includes a wax having an iodine value of 25 or less and a saponification value of 30 to 300. By using in combination with the second wax, coarsening of the particle size is prevented, and core particles having a small particle size and a narrow particle size distribution can be generated. By defining the iodine value, the effect of improving the dispersion stability of the wax can be obtained, the core particles can be formed uniformly with the resin and the colorant particles, and the core particles with a small particle size and a narrow particle size distribution can be formed. To do. The iodine value is preferably 20 or less, the saponification value is 30 to 200, more preferably the iodine value is 10 or less, and the saponification value is 30 to 150.

  On the other hand, if the iodine value is greater than 25, the dispersion stability is too good, the core particles cannot be formed uniformly with the resin and the colorant particles, and the floating particles of the wax tend to increase. The particle size distribution tends to be high. If the floating particles remain in the toner, filming of the photoreceptor or the like is caused. 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. When the saponification value is less than 30, the presence of unsaponifiable matter and hydrocarbons increases, and it becomes difficult to form uniform core particles having a small particle size. The filming of the photosensitive member and the charging property of the toner are deteriorated, and the charging property during continuous use is reduced. When it becomes larger than 300, suspended matter in the water system increases. The repulsion due to the charge action of the toner is less likely to be alleviated. In addition, fog and toner scattering increase.

  It is preferable that the heat loss at 220 ° C. of the wax having a defined iodine value and saponification value is 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 of the generated toner becomes broad.

Molecular weight characteristics in gel permeation chromatography (GPC) of waxes with prescribed iodine value and saponification value, 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 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 . It preferably has at least one molecular weight maximum peak. 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. This causes toner photoconductor filming. The particle size distribution of the generated toner 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 the low-temperature fixability is lowered. It becomes difficult to reduce the particle size of the generated particles when the emulsified dispersed particles of wax are generated.

  The first wax is preferably a material such as a meadow foam oil derivative, carnauba wax derivative, jojoba oil derivative, wood wax, beeswax, ozokerite, carnauba wax, canderia wax, ceresin wax or rice wax. Derivatives are also preferably used. One type or a combination of two or more types can be used.

  As the meadow foam oil derivative, meadow foam oil fatty acid, metal salt of meadow foam oil fatty acid, meadow foam oil fatty acid ester, hydrogenated meadow foam oil or meadow foam oil triester can be preferably used. An emulsion dispersion having a small particle size and a uniform particle size distribution can be prepared. It is a preferable material that is effective for low-temperature fixability in oilless fixing, prolonging the life of the developer, and improving transferability. These can be used alone or in combination of two or more.

  The meadow foam oil fatty acid obtained by saponification and decomposition of meadow foam oil is preferably composed of a fatty acid having 4 to 30 carbon atoms. As the metal salt, metal salts such as sodium, potassium, calcium, magnesium, barium, zinc, lead, manganese, iron, nickel, cobalt or aluminum can be used. High temperature non-offset property is good.

  Meadowfoam oil fatty acid esters include, for example, esters such as methyl, ethyl, butyl, glycerin, pentaerythritol, polypropylene glycol, or trimethylolpropane, and in particular, meadowfoam oil fatty acid pentaerythritol monoester, meadowfoam oil fatty acid pentaerythritol triester. Ester or meadow foam oil fatty acid trimethylolpropane ester is preferred. Effective for low-temperature fixability.

  Hydrogenated Meadowfoam oil is obtained by hydrogenating Meadowfoam oil to make unsaturated bonds saturated bonds. Low temperature fixability and glossiness can be improved.

  Furthermore, an esterification reaction product of a meadow foam fatty acid and a polyhydric alcohol such as glycerin, pentaerythritol, trimethylolpropane, or the like is obtained by using tolylene diisocyanate (TDI), diphenylmethane-4,4′-diisocyanate (MDI), or the like. An isocyanate polymer of a meadow foam oil fatty acid polyhydric alcohol ester obtained by crosslinking with isocyanate can also be preferably used. The spent property to the carrier is small and the life of the two-component developer can be extended.

  As jojoba oil derivatives, jojoba oil fatty acid, metal salt of jojoba oil fatty acid, jojoba oil fatty acid ester, hydrogenated jojoba oil, jojoba oil triester, maleic acid derivative of epoxidized jojoba oil, isocyanate of jojoba oil fatty acid polyhydric alcohol ester Polymers and halogenated modified jojoba oil can also be preferably used. An emulsion dispersion having a small particle size and a uniform particle size distribution can be prepared. Easy mixing and dispersion of resin and wax. It is a preferable material that is effective for low-temperature fixability in oilless fixing, prolonging the life of the developer, and improving transferability. These can be used alone or in combination of two or more.

  Jojoba oil fatty acid obtained by saponifying and decomposing jojoba oil consists of fatty acids having 4 to 30 carbon atoms. As the metal salt, metal salts such as sodium, potassium, calcium, magnesium, barium, zinc, lead, manganese, iron, nickel, cobalt, and aluminum can be used. High temperature non-offset property is good.

  Examples of jojoba oil fatty acid esters include esters such as methyl, ethyl, butyl, glycerin, pentaerythritol, polypropylene glycol, and trimethylol propane. Particularly, jojoba oil fatty acid pentaerythritol monoester, jojoba oil fatty acid pentaerythritol triester, jojoba Oil fatty acid trimethylolpropane ester and the like are preferable. Effective for low-temperature fixability.

  Hydrogenated jojoba oil is obtained by hydrogenating jojoba oil to make unsaturated bonds saturated bonds. Low temperature fixability and glossiness can be improved.

  Furthermore, esterification reaction products of jojoba oil fatty acid and polyhydric alcohols such as glycerin, pentaerythritol, trimethylolpropane, tolylene diisocyanate (TDI), diphenylmethane-4,4′-disicocyanate (MDI), etc. An isocyanate polymer of jojoba oil fatty acid polyhydric alcohol ester obtained by crosslinking with the above isocyanate can also be preferably used. The spent property to the carrier is small and the life of the two-component developer can be extended.

  The saponification value refers to the number of milligrams of potassium hydroxide 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. It is the number of grams of iodine absorbed, 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 weight of the sample cell is precisely weighed to 0.1 mg (W1 mg), and 10 to 15 mg of the sample is put in this, and then weighed to 0.1 mg (W2 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 (W3 mg). The apparatus is TGD-3000 manufactured by Vacuum Riko, the heating rate is 10 ° C./min, the maximum temperature is 220 ° C., the holding time is 1 min, and the heating loss (%) = W 3 / (W 2 −W 1) × 100. .

  Measurement of endothermic peak temperature (melting point ° C) and onset temperature by DSC of wax uses TA Instruments Q100 type (use a genuine electric refrigerator for cooling), measurement mode is “standard”, purge gas (N2) The flow rate is 50 ml / min, the power is turned on, the temperature in the measurement cell is set to 30 ° C., and the sample is left in that state for 1 hour. The aluminum pan containing the sample was put into the measuring instrument. Thereafter, the temperature was maintained at 5 ° C. for 5 minutes, and the temperature was increased to 150 ° C. at a temperature increase rate of 1 ° C./min. For the analysis, “Universal Analysis Version 4.0” attached to the apparatus was used. In the graph, the horizontal axis represents the bath temperature, the vertical axis represents the heat flow, the temperature at which the endothermic curve starts to rise from the baseline was the onset temperature, and the peak value of the endothermic curve was the endothermic peak temperature (melting point).

  In addition, instead of the wax described above as the first wax, or in combination with a hydroxystearic acid derivative, glycerin fatty acid ester, glycol fatty acid ester or sorbitan fatty acid ester material is also preferable, and one or a combination of two or more types is used. Is also effective. Uniform emulsification-dispersed small particle size core particles can be prepared, and when used in combination with the second wax, coarsening of the particle size is prevented, and core particles having a small particle size and a narrow particle size distribution can be generated.

  As a derivative of hydroxystearic acid, methyl 12-hydroxystearate, butyl 12-hydroxystearate, propylene glycol mono12-hydroxystearate, glycerin mono12-hydroxystearate or ethylene glycol mono12-hydroxystearate is suitable. Material. It has low-temperature fixability, oil separability improvement effect, and photoconductor filming prevention effect in oilless fixing.

  Glycerin fatty acid esters include glycerol stearate, glycerol distearate, glycerol tristearate, glycerol monopalmitate, glycerol dipalmitate, glycerol tripalmitate, glycerol behenate, glycerol dibehenate, glycerol tribehenate, glycerol monomyristate Glycerin dimyristate or glycerin trimyristate is a suitable material. It has the effect of alleviating cold offset at low temperatures and preventing deterioration of transferability in oilless fixing.

  As the glycol fatty acid ester, propylene glycol fatty acid esters such as propylene glycol monopalmitate or propylene glycol monostearate, or ethylene glycol fatty acid esters such as ethylene glycol monostearate or ethylene glycol monopalmitate are suitable materials. Low temperature fixability, good slippage during development, and has the effect of preventing carrier spent.

  As sorbitan fatty acid ester, sorbitan monopalmitate, sorbitan monostearate, sorbitan tripalmitate or sorbitan tristearate are suitable materials. Furthermore, materials such as stearic acid ester of pentaerythritol and mixed esters of adipic acid and stearic acid or oleic acid are preferable, and one kind or a combination of two or more kinds can be used. It has the effect of improving the separability of paper in oilless fixing and the effect of preventing photoconductor filming.

  As the second wax, a fatty acid hydrocarbon wax such as polypropylene wax, polyethylene wax, polypropylene polyethylene copolymer wax, microcrystalline wax, paraffin wax, or Fischer-to-push wax can be preferably used.

  Further, in order to uniformly encapsulate the wax in the resin without desorbing and floating during the 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.

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

  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% diameter (PR84) for the volume particle diameter cumulative distribution when integrated from the small particle diameter side. It is preferable that emulsified and dispersed to a size of 400 nm or less and PR84 / PR16 of 1.2 to 2.0, with particles of 200 nm or less being 65% by volume or more and particles exceeding 500 nm being 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 core particle is formed by mixing and agglomerating the resin particle dispersion, the colorant particle dispersion, and the wax particle dispersion, the 50% diameter (PR50) is 20 to 200 nm, so that the wax becomes resin particles. It is easy to be taken in between, preventing aggregation between the waxes itself, and uniform dispersion. Particles that are taken into the resin particles and float in the water can be eliminated.

  Furthermore, when obtaining aggregated particles obtained by heating the core particles in an aqueous system, the molten resin particles surround and include the molten wax particles because of the surface tension, and the release agent is included in the resin. It becomes easy.

  PR16 is greater than 200 nm, 50% diameter (PR50) is greater than 300 nm, PR84 is greater than 400 nm, PR84 / PR16 is greater than 2.0, particles of 200 nm or less are less than 65% by volume, and particles greater than 500 nm When the amount exceeds 10% by volume, the wax is less likely to be taken in between the resin particles, and aggregation tends to occur frequently only between the waxes themselves. In addition, particles that are not taken into the core particles and float in water tend to increase. When the core particles are obtained by heating the core particles in an aqueous system to obtain molten core particles, the molten resin particles are unlikely 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. There is a tendency for the storage stability of the to decrease. In addition, the load increases during dispersion, heat generation increases, and productivity tends to decrease.

  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 on the wall of the tank having a constant 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 treatment liquid can be formed by a treatment for 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 prepared.

  The particle size distribution of fine particles can be made narrower and sharper than a disperser such as a homogenizer. Further, even if the particles are left for a long time, the fine particles forming the dispersion liquid do not re-aggregate and can maintain a stable dispersion state, and the storage 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. Alternatively, 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. .

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.
(4) Pigment Yellow pigment used in the present embodiment C.I. I. Pigment Yellow 74 is available from manufacturers such as Dainippon Ink, Dainichi Seika, Sanyo Dye. As the pigment, a method of emulsifying from a powder state, or a pigment prepared by emulsification in the form of a pigment-containing paste prepared in an aqueous medium from the synthesis stage without passing through a dry state can also be suitably used.

  Carbon black is used as the black pigment. As described above, the DBP oil absorption (ml / 100 g) of carbon black is 45 to 70. The particle diameter is preferably 20 to 40 nm. Preferably the particle size is 20-35 nm. The particle diameter is an arithmetic average diameter measured by an electron microscope. When the particle size is large, the coloring power is lowered. When the particle size is small, dispersion in the liquid becomes difficult. For example, Mitsubishi Chemical Corporation # 52 (particle size 27 nm, DBP oil absorption 63 ml / 100 g), # 50 (28 nm, 65 ml / 100 g), # 47 (23 nm, 64 ml / 100 g), # 45 (same as above) 24 nm, 53 ml / 100 g), # 45L (24 nm, 45 ml / 100 g), Cabot REGAL 250R (35 nm, 46 ml / 100 g), REGAL 330R (25 nm, 65 ml / 100 g), MOGULL (24 nm) , 60 ml / 100 g). More preferred are # 45, # 45, and LREGAL250R.

DBP oil absorption (JISK6217) was measured by putting 20 g (Ag) of sample dried at 150 ° C. ± 1 ° C. for 1 hour into a mixing chamber of an absorber meter (manufactured by Brabender, spring tension 2.68 kg / cm), After setting the limit switch to about 70% of the maximum torque in advance, the mixer is rotated. At the same time, DBP (specific gravity 1.045 to 1.050 g / cm ³ ) is added from the automatic burette at a rate of 4 ml / min. As the end point is approached, the torque increases rapidly and the limit switch is turned off. The DBP oil absorption (= Bx100 / A) (ml / 100 g) per 100 g of the sample is determined from the DBP amount (Bml) added so far and the sample weight.

  Examples of magenta pigments include C.I. 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 and 8 can be preferably used.

  Examples of cyan pigments include C.I. I. A blue dyed pigment of phthalocyanine and its derivatives such as Pigment Blue 15: 3 can be preferably used. The addition amount is preferably 3 to 8 parts by weight with respect to 100 parts by weight of the binder resin.

The volume average particle size of each particle dispersion after the dispersion treatment is usually 1 μm or less, 0.01 to 1 μm, preferably 0.05 to 0.5 μm, more preferably 0.05 to 0.1 μm. Is preferred. 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).
(5) External additive In this embodiment, inorganic fine powder is mixed and added as an external additive. External additives include silica, alumina, titanium oxide, zirconia, magnesia, ferrite, magnetite and other metal oxide fine powders, barium titanate, calcium titanate, titanates such as strontium titanate, barium zirconate, zircon Zirconates such as calcium acid and strontium zirconate, or mixtures thereof are used. The external additive is hydrophobized as necessary.

  Examples of the silicone oil-based material to be treated by the external additive include dimethyl silicone oil, methyl hydrogen silicone oil, methyl phenyl silicone oil, epoxy-modified silicone oil, carboxyl-modified silicone oil, methacryl-modified silicone oil, and alkyl-modified silicone oil. An external additive treated with at least one of fluorine-modified silicone oil, amino-modified silicone oil, and chlorophenyl-modified silicone oil is preferably used. Examples thereof include SH200, SH510, SF230, SH203, BY16-823 or BY16-855B manufactured by Toray Dow Corning Silicone.

  For the treatment, the external additive and the material such as silicone oil are mixed with a mixer such as a Henschel mixer (FM20B manufactured by Mitsui Mining Co., Ltd.), the method of spraying the silicone oil-based material onto the external additive, the silicone oil as the solvent There is a method of preparing by dissolving or dispersing a system material, mixing with an external additive, and then removing the solvent. The silicone oil-based material is preferably blended in an amount of 1 to 20 parts by weight with respect to 100 parts by weight of the external additive.

  As silane coupling agents, dimethyldichlorosilane, trimethylchlorosilane, allyldimethylchlorosilane, hexamethyldisilazane, allylphenyldichlorosilane, benzylmethylchlorosilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, Vinyltriacetoxysilane, divinylchlorosilane, dimethylvinylchlorosilane, or the like can be preferably used. The silane coupling agent treatment is a dry treatment in which the vaporized silane coupling agent is reacted with the external additive made into a cloud by stirring or the like, or a silane coupling agent in which the external additive is dispersed in a solvent is dropped. It is processed by a wet method or the like.

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

  The external additive having positive electrode chargeability is treated with aminosilane, amino-modified silicone oil or epoxy-modified silicone oil.

  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.

  Moreover, it is also preferable to treat the surface of the external additive with one or more selected from the group of fatty acid esters, fatty acid amides, fatty acids and fatty acid metal salts (hereinafter referred to as fatty acids). Surface-treated silica or titanium oxide fine powder is more preferable.

  Examples of fatty acids or fatty acid metal salts include caprylic acid, capric acid, undecylic 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 12 to 22 carbon atoms are preferred.

Moreover, as a metal which comprises a fatty-acid metal salt, aluminum, zinc, calcium, magnesium, lithium, sodium, lead, or barium is mentioned, Among these, aluminum, zinc, or sodium is 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. Further, it is considered that the processability with the external additive is improved during the treatment.

  The aliphatic amide has 16 to 24 carbon atoms such as palmitic acid amide, palmitoleic acid amide, stearic acid amide, oleic acid amide, arachidic acid amide, eicosenoic acid amide, behenic acid amide, erucic acid amide or ligrinoceric acid amide. Saturated or monovalent unsaturated aliphatic amides are preferably used.

  Examples of fatty acid esters include esters comprising higher alcohols having 16 to 24 carbon atoms and higher fatty acids having 16 to 24 carbon atoms such as stearyl stearate, palmityl palmitate, behenyl behenate or stearyl montanate, butyl stearate, Esters consisting of higher fatty acids having 16 to 24 carbon atoms and lower monoalcohols such as isobutyl behenate, propyl montanate or 2-ethylhexyl oleate, or fatty acid pentaerythritol monoester, fatty acid pentaerythritol triester, or fatty acid trimethylol Propane ester or the like is preferably used.

  Materials such as hydroxystearic acid derivatives, polyhydric alcohol fatty acid esters such as glycerin fatty acid ester, glycol fatty acid ester or sorbitan fatty acid ester are preferred, and one kind or a combination of two or more kinds can also be used.

  As a preferred form of the surface treatment, it is also preferred that the surface of the external additive to be treated is treated with a coupling agent and / or polysiloxane such as silicone oil and then treated with a fatty acid or the like. This is because a uniform treatment is possible as compared with the case where the fatty acid of the hydrophilic silica is simply treated, and the toner can be highly charged and the fluidity when added to the toner is improved. In addition, the above-described effects can be obtained even in a configuration in which fatty acid or the like is treated together with a coupling agent and / or silicone oil.

  Dissolve fatty acid in a hydrocarbon-based organic solvent such as toluene, xylene or hexane, and mix it with an external additive such as silica, titanium oxide, alumina, etc. It is produced by depositing, applying a surface treatment, and then removing the solvent and performing a drying treatment.

  The mixing ratio of the polysiloxane and the fatty acid is preferably 1: 2 to 20: 1. When the ratio is higher than 1: 2, the amount of charge of the external additive increases, and the image density tends to decrease, and charge-up tends to occur in two-component development. When the amount of fatty acid or the like is less than 20: 1, the effect on transfer loss and reverse transferability tends to decrease.

  At this time, the ignition loss of the external additive whose surface is treated with fatty acid or the like is preferably 1.5 to 25% by weight. More preferably, it is 5-25 weight%, More preferably, it is 8-20 weight%. When the amount is less than 1.5% by weight, the function of the treating agent is not sufficiently exhibited, and the effect of improving the chargeability and transferability does not appear. If it exceeds 25% by weight, an untreated agent is present, which adversely affects developability and durability.

  Unlike the conventional pulverization method, the surface of the toner base particles produced according to the present invention is formed from only a resin, which is advantageous in terms of charge uniformity. This is because compatibility with the external additive used is important.

  A configuration in which 1 to 6 parts by weight of an external additive having an average particle diameter of 6 nm to 200 nm is externally added to 100 parts by weight of the toner base particles is preferable. When the average particle diameter is smaller than 6 nm, filming on the suspended particles and the photoreceptor tends to occur. The reverse transfer during transfer tends to occur. If it exceeds 200 nm, the fluidity of the toner tends to deteriorate. When the amount is less than 1 part by weight, the fluidity of the toner tends to deteriorate. Reverse transfer during transfer tends to occur easily. When the amount is more than 6 parts by weight, the floating particles and the filming on the photoreceptor tend to occur easily.

  Further, an external additive having an average particle diameter of 6 nm to 20 nm is added to 0.5 to 2.5 parts by weight with respect to 100 parts by weight of the toner base particles, and an external additive having an average particle diameter of 20 nm to 200 nm is added to 100 parts by weight of the toner base particles. On the other hand, a configuration in which at least 0.5 to 3.5 parts by weight is externally added is also preferable. By using an external additive that is functionally separated by this configuration, the charge imparting property and the charge retention property are improved, and a margin can be further taken against reverse transfer, dropout, and toner scattering during transfer. At this time, the ignition loss of the external additive having an average particle diameter of 6 nm to 20 nm is preferably 0.5 to 20% by weight, and the ignition loss of the average particle diameter of 20 nm to 200 nm is preferably 1.5 to 25% by weight. . By increasing the loss on ignition with an average particle size of 20 nm to 200 nm more than the loss on ignition of an external additive with an average particle size of 6 nm to 20 nm, it is effective for reverse transfer during transfer and voiding. Is demonstrated.

  By specifying the loss on ignition of the external additive, a margin can be taken against reverse transfer, dropout, and scattering during transfer. It is possible to improve the handling property in the developing unit and increase the uniformity of the toner density.

  If the loss on ignition with an average particle size of 6 nm to 20 nm is less than 0.5% by weight, the transfer margin for reverse transfer and hollow out tends to be narrow. If it exceeds 20% by weight, the surface treatment becomes uneven, and there is a tendency for variation in charging to occur. The ignition loss is preferably 1.5 to 17% by weight, more preferably 4 to 10% by weight.

  If the loss on ignition with an average particle size of 20 nm to 200 nm is less than 1.5% by weight, the transfer margin for reverse transfer and hollow out tends to be narrow. If it exceeds 25% by weight, the surface treatment becomes uneven, and there is a tendency for variation in charging to occur. The ignition loss is preferably 2.5 to 20% by weight, more preferably 5 to 15% by weight.

  The external additive having an average particle diameter of 6 nm to 20 nm and an ignition loss of 0.5 to 20% by weight is 0.5 to 2 parts by weight with respect to 100 parts by weight of the toner base particles, and the average particle diameter is 20 nm to 0.5 to 3.5 parts by weight of an external additive having 100 nm and an ignition loss of 1.5 to 25% by weight based on 100 parts by weight of the toner base particles, an average particle diameter of 100 to 200 nm, and an ignition loss of 0 A configuration in which at least 0.5 to 2.5 parts by weight of the external additive of 1 to 10% by weight with respect to 100 parts by weight of the toner base particles is externally added is also preferable. The structure of the external additive with the function of specifying the average particle size and loss on ignition improves the charge imparting property, charge retention, reverse transfer during transfer, and improvement of voids. Effective for removal.

  Further, an external additive having a positive charging property with an average particle diameter of 6 nm to 200 nm and an ignition loss of 0.5 to 25% by weight is further added to 0.2 to 1.5 parts by weight based on 100 parts by weight of the toner base particles. It is also preferable to perform the external addition treatment.

  The effect of adding an external additive having a positive charging property can prevent the toner from being overcharged during long-term continuous use, thereby further extending 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% by weight, more preferably 5 to 19% by weight.

  The average particle diameter is a value obtained by taking an enlarged photograph with an SEM and obtaining an average value of the major axis and minor axis of about 100 particles.

  For loss on drying (% by weight), 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 (% by weight) = [Loss on drying (g) / Amount of sample (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 (% by weight) = [Loss on ignition (g) / Sample amount (g)] × 100.

  Further, the moisture absorption amount of the treated external additive is preferably 1% by weight or less. Preferably it is 0.5 weight% or less, More preferably, it is 0.1 weight% or less, More preferably, it is 0.05 weight% or less. When the amount is more than 1% by weight, the chargeability is lowered, 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.

  The degree of hydrophobicity is determined by methanol titration, weighing 0.2 g of the product to be tested in 50 ml of distilled water charged in a 250 ml beaker. At the tip, methanol is dropped from a burette that is invaded in the liquid until the total amount of the external additive 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.

Hydrophobicity = (a / (50 + a)) × 100 (%).
(6) Toner powder physical properties In this embodiment, toner base particles containing a binder resin, a colorant and a wax have a volume average particle size of 3 to 6 μm, a volume-based variation coefficient of 10 to 25%, and a number-based distribution. The toner particles having a particle diameter of 2.0 to 3.63 μm in the toner have a content of 10 to 85% by number, and toner particles having a particle diameter of 3.5 to 4.53 μm in the volume-based distribution are 25 to 75 volume%. Toner particles having a particle size of 6.06 μm or more in a volume-based distribution are contained in an amount of 5% by volume or less,
The volume% of toner particles having a particle diameter of 3.5 to 4.53 μm in the volume-based distribution is V34, and the number% of toner particles having a particle diameter of 3.5 to 4.53 μm in the number-based distribution is P34. P34 / V34 is preferably in the range of 0.4 to 2.2.

  Preferably, the toner base particles have a volume average particle size of 3 to 5 μm, a volume-based variation coefficient of 10 to 20%, and a content of toner particles having a particle size of 2.0 to 3.63 μm in a number-based distribution is 15 ~ 85% by number, toner particles having a particle size of 3.5 to 4.53 μm in a volume-based distribution are 30 to 65% by volume, toner particles having a particle size of 6.06 μm or more in a volume-based distribution are 2 volumes %, And P34 / V34 is preferably in the range of 0.5 to 1.5.

  More preferably, the toner base particles have a volume average particle size of 3 to 5 μm, a volume-based variation coefficient of 10 to 16%, and a content of toner particles having a particle size of 2.0 to 3.63 μm in a number-based distribution. 25 to 85% by number, toner particles having a particle size of 3.5 to 4.53 μm in the volume-based distribution are 40 to 60% by volume, toner particles having a particle size of 6.06 μm or more in the volume-based distribution are It is preferably contained at 0.5% by volume or less, and P34 / V34 is preferably in the range of 0.5 to 0.9.

  In a high resolution image quality, and further in a tandem configuration, it is possible to prevent reverse transfer during transfer and prevent voids and achieve both oil-less fixing. The toner particle size distribution affects toner fluidity, image quality, storage stability, filming on a photoreceptor, a developing roller, and a transfer body, aging characteristics, transferability, and in particular, multi-layer transfer in a tandem system. In addition, it affects the high temperature non-offset property and glossiness in oilless fixing. In a toner containing 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 6 μm, it is impossible to achieve both image quality and transfer. When the volume average particle size is less than 3 μm, the handling of toner particles during development tends to be difficult.

  If the content of toner particles having a particle size of 2.0 to 3.63 μm in the number-based distribution is less than 10% by number, it tends to be impossible to achieve both image quality and transfer. If it exceeds 85% by number, the handling properties of the toner base particles during development tend to be difficult. Further, filming on the photosensitive member, the developing roller, and the transfer member may occur. Furthermore, fine powder tends to be offset at high temperature because of its high adhesion to the heat roller. In the tandem system, toner aggregation tends to be strong, and a transfer failure of the second color tends to occur during multilayer transfer. An appropriate range is required.

  When toner particles having a particle size of 3.5 to 4.53 μm in the volume-based distribution are less than 25% by volume, the image quality tends to deteriorate. If it exceeds 75% by volume, it tends to be impossible to achieve both image quality and transfer.

  If toner particles having a particle size of 6.06 μm or more in the volume reference distribution are contained in excess of 5% by volume, the image quality is deteriorated, which tends to cause transfer defects.

  When P34 / V34 is smaller than 0.4, the amount of fine powder present becomes excessive, and the fluidity, transferability, and background fog tend to deteriorate. When it is larger than 2.2, there are many large particles and the particle size distribution becomes broad, and the image quality tends not to be improved.

  The purpose of defining P34 / V34 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 filming or transfer to the photosensitive member is performed. It tends to cause defects.

  Further, the shape index of the toner is preferably 1.25 to 1.55, more preferably 1.33 to 1.46, and still more preferably 1.35 to 1.42. The crazing property due to the rubber blade that progresses in a spherical shape decreases, and when the amorphous shape proceeds, the transfer property tends to decrease.

  Further, when the shape index of the toner base particles is SC and the volume average particle diameter is d50 (μm), the product of SC and d50 (SC × d50) is preferably 3.9 to 7.3. Preferably it is 4.0-6.6, More preferably, it is 4.1-5.7.

  By prescribing this numerical value, the cleaning performance with the rubber blade tends to deteriorate when the spheroidization of the shape proceeds when the particle shifts to a small particle size. In addition, when the particles shift to a large particle size, if the shape progresses to an irregular shape, there is a tendency to deteriorate transferability and image quality. In the case of a small particle size, the shape is shifted to an irregular shape. In order to maintain the cleaning property and to maintain the image quality by shifting the shape to a spherical shape in the case of a large particle size particle, the product of SC and d50 is set within a certain range. If it is smaller than 3.9, the cleaning property tends to deteriorate. If it is larger than 7.3, the image quality tends to deteriorate.

  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% by weight. About 2 mg of the toner to be measured is added to about 50 ml, and the electrolyte solution in which the sample is suspended is dispersed with an ultrasonic disperser for about 3 minutes Processing was performed, 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.

  The shape index was obtained by the following formula using a real surface view microscope (VE7800) manufactured by Keyence Corporation, taking about 100 toner base particles magnified 1000 times, measuring the maximum length and the projected area (d : Maximum length of toner particles, A: projected area of toner particles).

SC (shape factor) = π · d ² / (4 · A)
(7) Oilless Color Fixation In this embodiment, the present invention is suitably used for an electrophotographic apparatus having a fixing process of an oilless fixing configuration in which oil is not used as a toner fixing means. 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.
(8) 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 photosensitive member, 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. Take the configuration in the machine The size of the printer and the printing speed are both compatible. 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.

(Example of carrier production)
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 4) are methyl groups, that is, (CH ₃ ) ₂ SiO _2/2 units are 15.4 mol%, and R ₃ represented by (Chemical Formula 5) is a methyl group, that is, 250 g of polyorganosiloxane having a CH ₃ SiO _3/2 unit of 84.6 mol% and CF ₃ CH ₂ CH ₂ Si (OCH ₃ ) ₃ 21 g were reacted to obtain a fluorine-modified silicone resin. 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 CA1.
(2) Preparation of resin particle dispersion Next, examples of the toner of the present invention will be described, but the present invention is not limited to these examples.
(Table 1) shows the binding obtained in the resin particle dispersions (RL1, RL2, RL3, RH1, RH2, rl4, rl5, rh3, rh4) according to the present invention, which were prepared as examples of preparing the resin particle dispersion. The characteristic of resin is shown. “Mn” is the number average molecular weight, “Mw” is the weight average molecular weight, “Mz” is the Z average molecular weight, and “Mw / Mn” is the ratio Mw / Mn of the weight average molecular weight (Mw) to the number average molecular weight (Mn). , “Mz / Mn” is the ratio Mz / Mn of Z average molecular weight (Mz) and number average molecular weight (Mn), “Mp” is the peak value of molecular weight, Tg (° C.) is the glass transition point, and Ts (° C.) is softened Represents a point. (Table 2) shows the nonionic amount (g), the anionic amount (g), and the ratio of the nonionic amount (% by weight) to the total amount of the surfactant used in each resin particle dispersion.

(a) Preparation of resin particle dispersion RL1 A monomer liquid composed of 240.1 g of styrene, 59.9 g of n-butyl acrylate, and 4.5 g of acrylic acid was added to 440 g of ion-exchanged water, and a nonionic surfactant. (Sanyo Kasei Co., Ltd .: Nonipol 400) 7.2 g, anionic surfactant (Daiichi Kogyo Seiyaku, Neogen S20-F (20 wt% concentration)) 24 g (substantial anion amount 4.8 g), dodecanethiol 6 g Then, 4.5 g of potassium persulfate was added thereto, and emulsion polymerization was performed at 75 ° C. for 4 hours. Thereafter, aging treatment is further performed at 90 ° C. for 2 hours, and resin particles having Mn of 7200, Mw of 13800, Mz of 20500, Mp of 10800, Ts of 98 ° C., Tg of 52 ° C., and a median diameter of 0.14 μm are dispersed. A resin particle dispersion RL1 was prepared. The pH of the resin dispersion at this time was 1.8.

  (Table 3) shows monomers used for each resin particle dispersion based on the preparation of the resin particle dispersion RL1 in the emulsion polymerization of each resin particle dispersion RL2, RL3, RH1, RH2, rl4, rl5, rh3, rh4. The blending amount of etc. is shown.

(3) Preparation of pigment dispersion (Table 4) The pigment used in Table 5 and the surfactant used are shown.

(a) 308 g of ion-exchanged water and 12 g of surfactant SA2 were weighed in a 1 L beaker and stirred with a magnetic stirrer until the solid content of the surfactant was dissolved. To this surfactant aqueous solution, C.I. I. 80 g of Pigment Yellow 74 (manufactured by Sanyo Color Co., Ltd.) was added, followed by stirring with a magnetic stirrer for 10 minutes. Next, the contents were transferred to a 1 L tall beaker and dispersed using a homogenizer (manufactured by IKA, T-25) at a rotation speed of 9500 rpm for 10 minutes. This dispersion was further dispersed with a disperser (TK Fillmix: 56-50 manufactured by Tokushu Kika Co., Ltd.). The produced dispersion was designated as a pigment particle dispersion PYS2. The pigment concentration was 20% by weight.

  Hereinafter, based on the adjustment conditions of the pigment particle dispersion PYS2, pigments and dispersants used in each pigment dispersion are shown in Table 6.

(4) Preparation of Wax Dispersion (Table 7), (Table 8) and (Table 9) were respectively used in the preparation of the wax particle dispersion according to the present example formed as a preparation example of the wax particle dispersion. The wax material and its properties are shown.

(a) Preparation of Wax Particle Dispersion WA2 FIG. 3 is a schematic view of a stirring and dispersing device (TK Film Mix manufactured by Tokushu Kika Co., Ltd.), and FIG. Reference numeral 801 denotes an outer tank, in which cooling water is injected from 808 and discharged from 807. Reference numeral 802 denotes a dam plate that stops the liquid to be processed, and a hole is formed in the central portion. Reference numeral 803 denotes a rotating body that rotates at a high speed and is fixed to the shaft 806 and can rotate at 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 MAX of the rotating body can be up to 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 during high-pressure processing or batch processing.

  In a state of normal pressure in the tank, 67 g of ion exchange water, 3 g of surfactant (SA3), and 30 g of wax (W-1) are charged, the speed of the rotating body is 5 min at 30 m / s, and then the rotating speed is 50 m / sec. s and treated for 2 min. A wax particle dispersion WA2 was formed.

  Hereinafter, based on the adjustment conditions of the wax particle dispersion WA2, the wax particle dispersions (WA3 to WA7, WA10 to WA13, WA15 to WA17), and the wax particle dispersions for comparison (wa1, wa8, wa9, wa14). (Table 10) and (Table 11) show the types and properties of the waxes and surfactants used in (1). “First wax” and “second wax” indicate the wax material charged in the wax particle dispersion, and the value in parentheses at the end of the symbol indicating the wax is the blended weight composition amount (weight ratio) of the wax. ). Further, when the waxes W13 and W14 are used, the inside of the tank is pressurized to 0.4 MPa.

(5) Preparation of toner base
(a) The toner base (YT2, YT3, YT6 to YT8, YT11, YT12, YT15) according to the present invention prepared as an example of the toner base in preparation of the toner base YT2 (Table 12) and a toner base for comparison Each composition is shown about (yt1, yt4, yt5, yt9, yt10, yt13, yt14, yt16-yt20).

  204 g of the first resin particle dispersion RL1, 56 g of the colorant particle dispersion PYS2, and 60 g of the wax particle dispersion WA3 are placed in a cylindrical 2 L glass container equipped with a thermometer, a cooling pipe, a pH meter, and a stirring blade. Then, 400 ml of ion-exchanged water was added and mixed for 10 minutes using a homogenizer (manufactured by IKA: Ultra Tarrax T25) to prepare a mixed particle dispersion. The pH of the obtained mixed dispersion was 3.5.

  Thereafter, 1N NaOH was added to the obtained mixed dispersion to adjust the pH to 11.5, and then 220 g of a 23 wt% magnesium sulfate aqueous solution was added and stirred for 10 min. Thereafter, the temperature was raised from 20 ° C. to 90 ° C. at a rate of 1 ° C./min, followed by heat treatment for 2 hours to obtain core particles. The obtained core particle dispersion had a pH of 9.1.

  Thereafter, 120 g of the second resin particle dispersion RH4 having a pH adjusted to 10.5 was continuously added dropwise at a water temperature of 90 ° C. over a required time of 30 minutes, and 1.5 hours after completion of the addition. Heat treatment was performed to obtain particles in which the second resin particles were fused.

  After cooling, the product (toner base material) was filtered and washed 7 times with ion-exchanged water. Thereafter, the obtained toner base was dried at 35 ° C. for 8 hours with a fluid dryer to obtain toner base YT2.

  The toner bases YT3, YT6 to YT8, YT11, YT12, YT15, yt1, yt4, yt5, yt9, yt10, yt13, yt14, and yt16 to yt20 are based on the conditions of YT2, and the pigment and wax are changed. Agglomeration was observed.

  Table 13 shows the characteristics obtained with the toner base prepared. d50 (μm) represents the volume average particle size of the toner base particles, and the volume variation coefficient represents the spread of the particle size distribution on the volume basis of the toner base particles in the obtained toner base.

  The toner bases YT2, YT3, YT6 to YT8, YT11, YT12, and YT15 become substantially transparent by heat treatment for 2 to 5 hours after the liquid temperature reaches 90 ° C., and the resin particles, pigment particles, and wax particles Aggregation progresses and particles with a small particle size and a narrow particle size distribution are formed.

  In the toner bases yt1, yt5, yt10, and yt14, the aggregation reaction proceeds and particles are formed, but the generated particles tend to be coarse.

  In the toner bases yt4, yt9, yt13, and yt16, the aggregation of the reaction liquid does not proceed, and even after the heat treatment for 6 hours, it seems that the liquid remains cloudy and the wax particles remain floating.

The toner bases yt17 to yt20 appear to be in a state in which the pigment particles are floating or partly agglomerated while the liquid remains in a yellow turbid state.
(b) Preparation of toner base YT22 (Table 14) includes toner bases (YT22, YT23, YT26, YT27, YT30, YT31, YT34) according to the present invention, which are prepared as toner base preparation examples, and toner bases for comparison. Each composition is shown about (yt21, yt24, yt25, yt28, yt29, yt32, yt33, yt35-yt38).

  204 g of the first resin particle dispersion RL2, 56 g of the colorant particle dispersion PYS2, and 80 g of the wax particle dispersion WA11 are added to 2000 ml of a four-necked flask equipped with a thermometer, a condenser, a stirring rod, and a pH meter. Then, 400 ml of ion-exchanged water was added, and mixed for 10 minutes using a homogenizer (manufactured by IKA: Ultra Turrax T25) to prepare a mixed particle dispersion. The pH of the obtained mixed dispersion was 3.5.

  Thereafter, 1N NaOH was added to the obtained mixed dispersion to adjust the pH to 11.5 and stirred for 10 minutes. Thereafter, when the temperature was increased from 20 ° C. at a rate of 1 ° C./min and reached 90 ° C., 220 g of a 23 wt% magnesium sulfate aqueous solution was continuously added dropwise over a required time of 30 min, followed by heat treatment for 1 hour. Heat treatment was performed at 90 ° C. for 1 hour to obtain core particles. The obtained core particle dispersion had a pH of 9.2.

  Thereafter, 85 g of the second resin particle dispersion RH5 having a pH adjusted to 10.4 is added at a water temperature of 92 ° C. at a dropping rate of 5 g / min. Thus, particles in which the second resin particles were fused were obtained.

  After cooling, the 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 toner base YT22.

  The toner bases YT23, YT26, YT27, YT30, YT31, YT34, yt21, yt24, yt25, yt28, yt29, yt32, yt33, yt35 to yt38 are based on the conditions of YT22, and the pigment and wax particles are changed. The cohesiveness of was observed.

  Table 15 shows the characteristics obtained in the toner base prepared.

  The toner bases YT22, YT23, YT26, YT27, YT30, YT31, and YT34 are substantially transparent by the heat treatment for 0.5 to 3.5 hours after the liquid temperature reaches 90 ° C., and the resin particles and pigment particles In addition, agglomeration of the wax particles proceeds, and particles having a small particle size and a narrow particle size distribution are formed.

  In the toner bases yt21, yt25, yt29, and yt33, the aggregation reaction proceeds and particles are formed, but the generated particles tend to be coarse.

  In the toner bases yt24, yt28, yt32, and yt35, the aggregation of the reaction liquid does not proceed, and even after the heat treatment for 6 hours, the liquid remains cloudy and the wax particles remain floating.

  The toner bases yt36 to yt38 appear to be in a state in which the pigment particles float or are partially agglomerated while the liquid remains in a yellow turbid state.

  Thus, when the HLB (Wh1) of the nonionic surfactant used in the wax particle dispersion is small, the agglomeration of the wax particles proceeds quickly, the yellow particles are easily left behind, and the white particles of the wax are easily generated. The particles tend to have a broad particle size distribution.

  When Wh1 increases, the aggregation of the wax particles does not easily proceed, and the cloudiness does not easily disappear, and the particle generation tends to hardly proceed.

  When the HLB (Yh1) of the nonionic surfactant used in the yellow pigment particle dispersion is small, the aggregation of the yellow particles is fast, the wax particles are easily left behind, and the generated particles have a broad particle size distribution.

  When Yh1 increases, the aggregation of the yellow pigment particles does not readily proceed, and the yellow turbidity of the liquid does not easily disappear, and particle generation tends to be difficult to proceed.

Moreover, when the difference between the two HLB values is smaller than 1, the generated particles tend to increase, and some resin particles tend to be left behind. On the other hand, when the difference is large, aggregation is difficult to proceed and yellow cloudiness tends to be difficult to disappear.
(6) External additive Next, examples of the external additive will be described. (Table 16) shows each material and its characteristic about the external additive (S1, S2, S3, S4, S5, S6, S7, S8, S9) used in the present Example.

In the case of processing with a plurality of types of the processing material 1 and the processing material 2, () shows the blending weight ratio of each processing material. “5-minute value” and “30-minute value” represent the charge amount ([μC / g]), which were measured by the blow-off method of frictional charge with an uncoated ferrite carrier. Specifically, in an environment of 25 ° C. and 45 RH%, after mixing 50 g of carrier and 0.1 g of silica, etc. in a 100 ml polyethylene container, stirring for 5 minutes and 30 minutes at a speed of 100 minutes- ^{1 by} longitudinal rotation. 0.3 g was collected and measured by blowing with nitrogen gas 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. A high charge amount of silica can exhibit such characteristics with a small amount of addition.
(7) Toner Composition and External Addition Processing Next, a toner composition and an example of external addition processing will be described. (Table 17) and (Table 18) show the respective material compositions of the toners according to the present invention prepared as toner preparation examples. Unblended indicates no addition. Note that the value in parentheses at the end of the symbol indicating the external additive in the external additive column represents the blending amount (parts by weight) of the external additive with respect to 100 parts by weight of the toner base. In the external addition process (Henschel mixer FM20B, manufactured by Mitsui Mining Co., Ltd.), stirring blade Z0S0 type, rotation speed 2000 min ⁻¹ , treatment time 5 min, and input amount 1 kg were performed.

  Other magenta toners were made of Clariant's PERMANENT RULINE F6B, cyan toners were Dainippon Ink's KETBLUE111, and black toners were Mitsubishi Chemical's # 45L, with the same composition as toner YT2.

  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 photoconductor 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 to effectively prevent slack and charge accumulation due to long-term use of the transfer belt 12, and the coating of the surface with a fluororesin is effective for toner filming on the surface of the transfer belt after long-term use. This is to prevent it. 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. If 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 If 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 (K) 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 supply is omitted, a DC voltage of −500 V and an AC 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 26 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 simultaneously with image formation, a YMCK toner image is formed on the transfer belt 12 by the action of the first transfer rollers 10C and 10K. 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 last K 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.
(Example of image evaluation)
Next, an example of image output evaluation for toner and two-component developer will be described. Here, an image forming apparatus is used, and several kinds of two-component developers with different mixing ratios of toner and carrier are subjected to a running durability test of 100,000 sheets each with A4 plate output to determine the charge amount and the image density. In addition to the measurement, the ground fog in the non-image area in the output sample, the uniformity in the entire solid image, the transferability (character skipping during transfer, reverse transfer, transfer omission), and toner filming were evaluated. Image density (ID) evaluation measured the black solid part using the reflection densitometer RD-914 made from Macbeth Division of Kollmorgen Instruments Corporate.

The charge amount was measured by the blow-off method of frictional charging with the ferrite carrier. Specifically, in an environment of 25 ° C. and a relative humidity of 45% RH, 0.3 g of a sample for durability evaluation was collected and measured by blowing with nitrogen gas at 1.96 × 10 ⁴ Pa for 1 minute.
(Table 19) (Table 20) shows that each of the two-component developers used in this example was subjected to a 50,000-sheet running durability test using toner and carrier configurations as the two-component developer and A4 size paper. The evaluation results are shown below.

  According to Spectrolino SpectroScan, the fog level is better than “A” if it is 0.01 or less, and if it is less than 0.03 or less than 0.03, the fog level is slightly increased from “B” or 0.03. If it is large and 0.06 or less, the fogged level “C” greater than 0.06 indicates a problematic level “D”.

  As for the uniformity of the entire solid image, when a solid image sample is taken on the entire surface in A4 size, if the image density partially changes and the image density difference is small, the comparison between “A” and “A”. If the image density difference is a level that can be seen a little, “B” is indicated. If the image density difference is partially noticeable, “B” is indicated.

  For character skipping at the time of transfer, when the characters “轟, 議, 魏” are printed, evaluation is performed with the state of toner present around the line. If the toner present around the line is low and the level is “ “A”, “B” if there is a little toner around the line, “C” if there is a lot of toner around the line, and a level where there is a lot of toner around the line. For example, “D”.

  In reverse transfer, when two or more color image samples are printed, the first color toner is transferred from the photoconductor to the transfer belt, and then the second color toner is transferred from the photoconductor to the transfer belt. A phenomenon in which part of the first color toner adheres to the second color photoconductor. In the evaluation, the toner of the first color adheres to the photoconductor of the second color, is removed from the photoconductor by the craning blade, and the amount of toner collected in the waste toner box is visually evaluated. “A” if the first and second color toners are hardly mixed, “B” if the first and second color toners are a little mixed, clearly mixed. For example, “C”.

  In the middle of transfer, a pattern “+” where lines intersect is printed, and the presence state of toner is evaluated at this intersection. If the level at which the toner is present at the intersection, “A” is indicated, “B” if the level at which there is no toner at the intersection is “B”, and “C” if no toner is present at the intersection. .

  Two-component developers DYT2, DYT3, DYT6, DYT7, DYT8, DYT11, DYT12, DYT15, DYT22, DYT23, DYT26, DYT27, DYT30, DYT31, and DYT34 using the toner of the present invention are 5 A4 sheets. The toner filming on the photosensitive member when the 10,000 sheet running durability test was performed was at a level of no practical problem. In addition, toner filming on the transfer belt was at a level causing no practical problem. Further, no transfer belt cleaning failure occurred. Even in a full-color image in which the three colors overlap, no paper wrapping around the fixing belt occurred.

  As for the image density before and after the running test, a high density image having an image density of 1.3 or more was obtained at the initial stage and after the durability test, and stable characteristics were exhibited. In addition, the non-image area fogging and the whole-surface solid image uniformity were high in resolution because there was no occurrence of ground fogging in the non-image area and no toner scattering. Further, the uniformity when taking the entire solid image at the time of development was also good. With regard to transferability (character skipping during transfer, reverse transfer, and transfer skipping), skipping and the like were at a level that has no practical problem. In addition, no transfer failure occurred even in a full-color image in which the three colors overlapped. The transfer efficiency was 90% or more.

  On the other hand, in comparison dyt1, dyt5, dyt10, dyt14, dyt21, dyt25, dyt29, and dyt33, the particles are coarse and the particle shape is indefinite, so that the image density is slightly lower, and the character skipping at the time of transfer is performed. There are a lot of hollows.

  In addition, dyt4, dyt9, dyt13, dyt16, dyt24, dyt28, dyt32, and dyt35 have much filming of the photoconductor which is considered to be caused by residual wax particles, and have a slight problem in transferability. . In addition, dyt 17 to dyt 20 and dyt 36 to dyt 38 have a problem of transferability due to the occurrence of filming on the photoconductor, which is considered to be the effect of the remaining floating particles of the pigment particles, and fogging.

In the fixing property evaluation, the evaluation is performed by measuring the fixing temperature and the temperature at which the offset phenomenon occurs at a high temperature in a fixing device using a solid image with an adhesion amount of 1.2 mg / cm ^{2 at} a process speed of 125 mm / s and a belt without applying oil. evaluated. The storage stability was evaluated by the state of the toner after being left at 55 ° C. for 24 hours.

  As a result, TYT2, TYT3, TYT6, TYT7, TYT8, TYT11, TYT12, and TYT15 blended with a wax having a certain melting point exhibited a low temperature fixing property of 150 ° C. or lower and a high temperature non-offset property of 200 ° C. or higher. The high-temperature storage stability was also good. TYT22, TYT23, TYT26, TYT27, TYT30, TYT31, and TYT34 exhibited a low temperature fixing property of 140 ° C. or lower and a high temperature non-offset property of 210 ° C. or higher. The high-temperature storage stability was also good.

  On the other hand, non-offset properties of dyt4, dyt9, dyt13, dyt16, dyt24, dyt28, dyt32, and dyt35 deteriorated and the high-temperature storage stability was also poor. This is probably due to the floating particles of wax.

  The present invention is useful not only for an electrophotographic system using a photoconductor but also for a system in which a paper or a toner containing a conductive material is directly deposited on a substrate as a wiring pattern.

Sectional drawing which shows the structure of the image forming apparatus used in the Example of this invention Sectional drawing which shows the structure of the fixing unit used in the Example of this invention Schematic of the stirring and dispersing apparatus used in the examples of the present invention View from above of the stirring and dispersing device used in the examples of the present invention Schematic of the stirring and dispersing apparatus used in the examples of the present invention View from above of the stirring and dispersing device used in the examples of the present invention Schematic of the stirring and dispersing apparatus used in the examples of the present invention View from above of the stirring and dispersing device used in the examples of the present invention Schematic of the stirring and dispersing apparatus used in the examples of the present invention View from above of the stirring and dispersing device used in the examples of the present invention Schematic of calculation method of softening point (melting temperature in 1/2 method) of binder resin by flow tester of the present 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 13 Drive tension roller 14 2nd transfer 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 207 Coil 801 Outer tank 802 Dam plate 803 Rotating body 806 Shaft 807 Cooling water discharge port 808 Cooling water injection port

Claims (25)

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. A toner containing core particles produced by aggregation,
The colorant is represented by C.I. I. Pigment Yellow 74 azo pigment,
The wax includes a wax having an endothermic peak temperature of 50 to 120 ° C. according to DSC method,
The main component of the surfactant used in the colorant particle dispersion and the wax particle dispersion contains a nonionic surfactant,
When the nonionic surfactant HLB (Hydrophile-Lipophile Balance) used for the colorant particle dispersion is Yh1, and the nonionic surfactant HLB (Hydrophile-Lipophile Balance) used for the wax particle dispersion is Wh1, A toner characterized by satisfying the relationship shown in Formula 1).

HLB (Wh1) of the nonionic surfactant used for the wax particle dispersion is 14.1-17.6,
The toner according to claim 1, wherein the HLB (Yh1) of the nonionic surfactant used in the colorant particle dispersion is 13.3 to 16.8. The surfactant used in the first resin particle dispersion is a mixture of a nonionic surfactant and an ionic surfactant, and the surfactant used in the colorant particle dispersion and the wax particle dispersion is non-main component. The toner according to claim 1, wherein the toner is only an ionic surfactant. The average number of moles of ethylene oxide added to the nonionic surfactant in which the colorant particles are dispersed is Peo1,
3. The toner according to claim 1, wherein the nonionic surfactant for dispersing the wax particles has a configuration satisfying the relationship represented by (Equation 2) when the average number of moles of ethylene oxide added is Weo1.

3. The toner according to claim 1, wherein the nonionic surfactant has a mixing ratio of the surfactant used in the first resin particle dispersion of 50 to 95 wt% with respect to the entire surfactant. The wax comprises at least a first wax and a second wax, the endothermic peak temperature of the first wax by DSC method (melting point Tmw1 (° C.)) is 50 to 90 ° C., and the second wax The toner according to claim 1, wherein an endothermic peak temperature (melting point Tmw2 (° C.)) of the wax is 80 to 120 ° C. The wax includes at least a first wax and a second wax, and the first wax includes an ester wax composed of at least one of a higher alcohol having 16 to 24 carbon atoms and a higher fatty acid having 16 to 24 carbon atoms. The toner according to claim 1, wherein the second wax contains an aliphatic hydrocarbon wax. The wax includes at least a first wax and a second wax, the first wax includes a wax having an iodine value of 25 or less and a saponification value of 30 to 300, and the second wax is an aliphatic hydrocarbon type The toner according to claim 1, wherein the toner comprises a wax. The toner according to claim 6, wherein the melting point of the second wax is 5 to 50 ° C. higher than the melting point of the first wax. 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. Producing a mixed solution,
A step of aggregating the first resin particles, the colorant particles, and the wax particles with a flocculant in the mixed liquid to generate core particles;
The colorant particle dispersion is treated with a surfactant mainly composed of a nonionic surfactant (Chemical Formula 2). I. Pigment Yellow 74 monoazo pigment,
The wax contains a wax having an endothermic peak temperature of 50 to 120 ° C. by DSC method, which is treated with a surfactant mainly composed of a nonionic surfactant,
When the HLB of the nonionic surfactant used in the colorant particle dispersion is Yh1, and the HLB of the nonionic surfactant used in the wax particle dispersion is Wh1, the relationship shown in (Equation 3) is satisfied. Toner manufacturing method.

After the heat treatment, the 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 method for producing a toner according to claim 10, wherein the core particles are generated by a step of adding an aggregating agent. The water temperature of the mixed dispersion obtained by mixing the 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 is the melting point of the wax. 12. The method for producing a toner according to claim 10, wherein the flocculant is added after reaching the above. Further, the second resin particle dispersion in which the second resin particles are dispersed is added to the core particle dispersion containing the core particles, and the second resin particles are fused to the core particles by heating. The method for producing a toner according to claim 10, further comprising a step. A step of adding the second resin particle dispersion in which the second resin particles whose pH value is adjusted to an alkaline state is dispersed to the core particle dispersion in which the core particles having a pH value in the range of 7 to 10 are dispersed. A method for producing a toner according to claim 13. The method for producing a toner according to claim 13 or 14, wherein the pH value of the second resin particle dispersion in which the second resin particles adjusted to an alkaline state are dispersed is in the range of 7.5 to 10.5. The pH value of the second resin particle dispersion in which the second resin particles are dispersed is adjusted to an alkaline state equal to or higher than the pH value of the core particle dispersion in which the core particles are dispersed, and added. A method for producing the toner according to claim. HLB (Wh1) of the nonionic surfactant used for the wax particle dispersion is 14.1-17.6,
The method for producing a toner according to claim 10, wherein the HLB (Yh1) of the nonionic surfactant used in the colorant particle dispersion is 13.3 to 16.8. The surfactant used in the first resin particle dispersion is a mixture of a nonionic surfactant and an ionic surfactant, and the surfactant used in the colorant particle dispersion and the wax particle dispersion is non-main component. The method for producing a toner according to claim 10, wherein only the ionic surfactant is used. The average number of moles of ethylene oxide added to the nonionic surfactant in which the colorant particles are dispersed is Peo1,
18. The method for producing a toner according to claim 10, wherein the nonionic surfactant for dispersing the wax particles has a configuration satisfying the relationship represented by (Equation 4) when the average number of moles of added ethylene oxide is Weo2.

19. The toner production according to claim 10, wherein the mixing ratio of the surfactant used in the first resin particle dispersion is such that the nonionic surfactant has 50 to 95 wt% with respect to the entire surfactant. Method. The wax comprises at least a first wax and a second wax, the endothermic peak temperature of the first wax by DSC method (melting point Tmw1 (° C.)) is 50 to 90 ° C., and the second wax The method for producing a toner according to claim 10, wherein the endothermic peak temperature (melting point Tmw2 (° C.)) of said wax by DSC method is 80 to 120 ° C. The wax includes at least a first wax and a second wax, and the first wax includes an ester wax composed of at least one of a higher alcohol having 16 to 24 carbon atoms and a higher fatty acid having 16 to 24 carbon atoms. The method for producing a toner according to claim 10 or 21, wherein the second wax contains an aliphatic hydrocarbon wax. The wax includes at least a first wax and a second wax, the first wax includes a wax having an iodine value of 25 or less and a saponification value of 30 to 300, and the second wax is an aliphatic hydrocarbon type The method for producing a toner according to claim 10 or 21, wherein the toner comprises a wax. The method for producing a toner according to any one of claims 21 to 23, wherein the melting point of the second wax is 5 to 50 ° C higher than the melting point of the first wax. At least a magnetic field generating means, a heating member having a rotating action having at least a heat generating layer and a release layer that generate heat by electromagnetic induction, and a pressing member having a rotating action that forms a fixed nip with the heating member. A transfer medium comprising a heating and pressurizing unit, onto which the toner according to any one of claims 1 to 9 or the toner produced by the method according to any one of claims 10 to 24 is transferred between the heating member and the pressing member. An image forming apparatus comprising: a fixing process for passing the toner through and fixing.

Images