JPWO2008056519A1 - Toner and toner production method - Google Patents

Abstract

The toner of the present invention is a toner containing toner base particles and an external additive, and the toner base particles are at least binder resin particles as first resin particles and third resin particles in an aqueous medium. Fusing the coated resin particles, which are the second resin particles, to the core particles produced by aggregating the shape-adjusting resin particles for adjusting the shape of the toner, the colorant particles and the wax particles, The softening point of the shape-adjusting resin particles and the coating resin particles is higher than the softening point of the binder resin particles. Thus, it is possible to provide a toner and a toner manufacturing method capable of appropriately controlling the shape of the toner, producing a toner having a small particle size having a narrow particle size distribution without a classification step, and preventing omission and scattering during transfer.

Description

  The present invention relates to a toner used in a copying machine, a laser printer, plain paper FAX, a color PPC, a color laser printer, a color FAX, and a complex machine thereof, and a toner manufacturing method.

  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 that realizes miniaturization, high speed, high image quality, and maintenance-free. Therefore, a cleaner-less process that collects waste toner during development without cleaning waste toner remaining after transfer in electrophotography, a tandem color process that enables high-speed output of color images, and fixing to prevent offset during fixing Oil-less fixing that achieves both high glossiness and high translucency, a clear color image and non-offset properties without using oil, 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 a color printer or the like, in a fixing process, it is necessary to melt and mix color toners in a color image to improve translucency. When toner melting 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 is deteriorated. Therefore, it is a necessary condition that the toner has a melting characteristic that dissolves quickly and has a light-transmitting property that does not disturb the color tone.

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

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

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

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

  However, in the conventional pulverizing / classifying operation in the kneading and pulverizing method, the particle size that can be actually provided economically and in performance is about 8 μm even if the particle size is reduced. At present, methods for producing small-diameter toners by various methods are being studied. In addition, a method for realizing oil-less fixing by blending a release agent such as wax in a low softening resin during melt kneading of the toner has been studied. However, there is a limit to the amount of wax that can be blended, and as the amount added increases, adverse effects such as a decrease in toner fluidity, an increase in voids during transfer, and the occurrence of filming on the photoconductor occur. Moreover, the surface state of the pulverized particles is uneven, and it is difficult to control the surface smoothness.

  Therefore, a toner production method using various polymerization methods different from the kneading and pulverization method has been studied. For example, when a toner is prepared by a suspension polymerization method, it is difficult to control the particle size distribution of the toner, and a classification operation may be required in order to generate particles having a narrow particle size distribution. Further, since the toner obtained by this method has a substantially spherical shape, there is a problem that the cleaning performance of the toner remaining on the photoconductor and the like by the cleaning blade is poor and the image quality reliability is impaired.

  In addition, a toner preparation method using an emulsion polymerization method is a method of preparing an aggregated particle dispersion by forming aggregated particles in a dispersion obtained by dispersing at least resin particles and colorant particles. Further, a resin fine particle dispersion obtained by dispersing resin fine particles is added to the resin particles, and the resin fine particles are attached to the aggregated particles, and then heated and fused.

  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. It is disclosed that a coating layer made of fine particles is formed on the surface of a particle by changing the pH of the composition and solution for forming the coating layer made of particles.

  In the following Patent Document 2, the release agent contains at least one ester composed of at least one of a higher alcohol having 12 to 30 carbon atoms and a higher fatty acid having 12 to 30 carbon atoms, and the resin particles have a molecular weight. It is disclosed that by including at least two different types of resin particles, it is excellent in fixing property, coloring property, transparency, color mixing property and the like.

  In Patent Document 3 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, the amount of colorant present on the particle surface is small, and even when subjected to long-term image formation in a high-humidity environment, changes in image density, fogging, and color changes due to changes in chargeability and developability The effect which does not generate | occur | produce is described.

  In Patent Document 4 below, in an electrostatic charge image developing toner including toner particles containing at least a resin and a colorant, the toner particles include a core containing resin A and at least one layer of resin B covering the core. A toner having a shell containing the toner and having a film thickness of 50 nm to 500 nm on the outermost surface layer of the shell is disclosed, and the effect of the toner for developing an electrostatic charge image having excellent offset resistance and good storage stability Is described.

  Patent Document 5 below discloses a toner having a shape factor of 100 to 137, forms an aggregate particle dispersion of resin fine particles and a colorant, and the obtained aggregate particle dispersion is used as a glass transition temperature ( Tg) or more, preferably Tg to Tg + 10 ° C. The temperature is increased to a temperature range of Tg to Tg + 10 ° C., for example, after the aggregate particles are grown to the desired toner particle diameter over 2 hours, the aggregation is stopped and further It is disclosed that the toner particles having a shape factor of 100 to 137 are formed by heating to the same temperature and fusing and coalescing the surfaces of the aggregate particles within 10 hours.

In the following Patent Document 6, shape index SF1 = 125 to 140 (where SF1 = (π / 4) × (L ² / A) × 100, L is the maximum length, A represents the projected area), cumulative volume average A toner having a particle size D _50V = 3 to 7 μm is disclosed, after mixing at least one resin particle dispersion and at least one colorant dispersion, and adding an aggregating agent to form aggregated particles, A manufacturing method is disclosed in which toner particles are manufactured by fusing the aggregated particles by heating to a temperature above the glass point of the resin particles.
Japanese Unexamined Patent Publication No. 57-45558 JP-A-10-301332 JP 2002-116574 A JP 2004-191618 A Japanese Patent Laid-Open No. 2000-131876 JP 2000-267331 A

  The shape of the toner tends to be determined from the relationship with the image forming process such as development, transfer, and cleaning process, and the toner shape has a larger shape index when the cleaning property of the photoreceptor or transfer belt is important. The potato-like shape increases the margin for cleaning. When emphasizing transferability, the toner shape is made closer to a sphere with a small shape factor to increase the transfer efficiency. Accordingly, it is important to be able to arbitrarily control the shape index in order to ensure a design margin for the image forming process.

  Conventionally, it has been disclosed that the shape is adjusted by adjusting the temperature and time when aggregated particles are generated. However, the adjustment of the temperature tends to cause a variation in the particle size distribution, making it difficult to adjust the shape and the particle size distribution. Further, adjusting the treatment time also tends to cause fluctuations in the particle size distribution, affects the surface smoothness of the particles, and may also affect the productivity. As described above, regarding the setting of the shape factor within the set value, the description of the specific method is not sufficient, and it cannot be said that the correlation between the condition of the method and the shape index is sufficiently obtained.

  The present invention can appropriately control the shape of the particles without affecting the particle size distribution and the surface smoothness of the particles, and can produce a small-sized toner having a narrow particle size distribution without a classification step. Objective.

  In addition, in oilless fixing without using oil in the fixing roller, a release agent such as wax is used in the toner to achieve low temperature fixing property, high temperature non-offset property, paper separating property from the fixing roller, etc. and high temperature state. The object is to achieve both storage stability during storage.

  In addition, an image forming apparatus is provided which can prevent high-efficiency by preventing omission and scattering during transfer.

  The toner of the present invention is a toner containing toner base particles and an external additive, and the toner base particles are at least binder resin particles as first resin particles and third resin particles in an aqueous medium. Fusing the coated resin particles, which are the second resin particles, to the core particles produced by aggregating the shape-adjusting resin particles for adjusting the shape of the toner, the colorant particles and the wax particles, The softening point of the shape-adjusting resin particles and the coating resin particles is higher than the softening point of the binder resin particles.

  The toner manufacturing method of the present invention is a toner manufacturing method including toner base particles and an external additive, wherein the toner base particles are at least a first resin in which binder resin particles are dispersed in an aqueous medium. A particle dispersion, a third resin particle dispersion in which resin particles for adjusting the shape of the toner are dispersed, a colorant particle dispersion in which colorant particles are dispersed, and a wax particle dispersion in which wax particles are dispersed. Mixing the liquid and aggregating to produce core particles, and adding the second resin particle dispersion in which the coated resin particles are dispersed to the core particle dispersion containing the generated core particles; And a step of fusing the second resin particles to the core particles.

FIG. 1 is a schematic sectional view showing the configuration of an image forming apparatus used in an embodiment of the present invention. FIG. 2 is a schematic sectional view showing the structure of the fixing unit used in the embodiment of the present invention. FIG. 3 is a schematic perspective view of the stirring and dispersing apparatus used in the embodiment of the present invention. FIG. 4 is a schematic plan view of the stirring and dispersing apparatus used in the examples of the present invention. FIG. 5 is a schematic cross-sectional view of the stirring and dispersing apparatus used in the examples of the present invention. FIG. 6 is a schematic plan view of the stirring and dispersing apparatus used in the examples of the present invention. FIG. 7 is a schematic perspective view of the stirring and dispersing apparatus used in the examples of the present invention. FIG. 8 is a schematic plan view of the stirring and dispersing apparatus used in the examples of the present invention. FIG. 9 is a schematic perspective view of the stirring and dispersing apparatus used in the examples of the present invention. FIG. 10 is a schematic plan view of the stirring and dispersing apparatus used in the examples of the present invention. FIG. 11 is an explanatory diagram of a method for calculating the softening point (melting temperature in the 1/2 method) of the binder resin by the flow tester of the present invention. FIG. 12 is a scanning electron microscope (SEM, magnification 5000 times) observation image of the toner ct1 produced in the example of the present invention. FIG. 13 is an SEM observation image (magnification 3000 times) of the toner CT2 produced in the example of the present invention. FIG. 14 is an SEM observation image (magnification 3000 times) of the toner CT4 produced in the example of the present invention. FIG. 15 is an SEM observation image (magnification 3000 times) of the toner ct5 produced in the example of the present invention. FIG. 16 is an SEM observation image (magnification 3000 times) of the toner CT7 produced in the example of the present invention. FIG. 17 is an SEM observation image (magnification 3000 times) of the toner CT8 produced in the example of the present invention. FIG. 18 is an SEM observation image (magnification 3000 times) of the toner ct11 produced in the example of the present invention. FIG. 19 is an explanatory diagram for explaining the shape index of the present invention.

  In the present invention, at least the first resin particles, the third resin particles for adjusting the shape of the toner, the colorant particles, and the wax particles are aggregated into the core particles formed in the aqueous medium. By fusing the resin particles, it is possible to arbitrarily control the shape of the particles, and at the same time, the toner base particles are made coarse, and the toner base particles having a small particle size and a narrow particle size distribution are created without a classification step. can do.

  In addition, storage stability can be maintained while improving low-temperature fixability / glossiness and high-temperature non-offset properties.

  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.

  Hereinafter, each element of the present invention will be described.

(1) Polymerization step The resin particle dispersion is prepared by homopolymerization or copolymerization of a vinyl monomer (vinyl type) by subjecting the vinyl monomer to emulsion polymerization or seed polymerization in a surfactant. Resin) is dispersed in a surfactant. 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 a 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 made of resin other than the vinyl resin are dispersed in the surfactant is prepared.

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

  The colorant particle dispersion is prepared by adding colorant particles in water to which a 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 the above-described dispersion means.

  Toners are required to have further low-temperature fixing, high-temperature non-offset property in oilless fixing, releasability, high transparency of color images, and storage stability under a certain high temperature, and must satisfy these simultaneously. I must.

  The toner of the present invention includes, in an aqueous medium, at least a first resin particle dispersion in which first resin particles are dispersed, and a third resin particle in which third resin particles for adjusting the shape of the toner are dispersed. A resin particle dispersion, a colorant particle dispersion in which colorant particles are dispersed, and a wax particle dispersion in which wax particles are dispersed are mixed and aggregated to produce core particles. Then, a second resin particle dispersion in which the second resin particles are dispersed is added to the core particle dispersion containing the generated core particles, and the second resin particles are fused to the core particles. Toner.

  The third resin particles are blended with the core particles for the purpose of controlling the shape of the particles. By adding resin particles having a certain relationship with the characteristics of the first resin particles, the shape can be changed by changing the aggregation reactivity of the core particles.

As a preferable characteristic of the third resin particle, when the softening point in the melt viscosity characteristic of the third resin particle is Ts3 (° C.) and the softening point in the melt viscosity characteristic of the first resin particle is Ts1 (° C.),
Ts1 + 30 ° C ≦ Ts3 ≦ Ts1 + 80 ° C
Satisfy the relationship. Due to the presence of the third resin particles having a certain softening point, the agglomeration reaction during the heat treatment delays the state in which the agglomerated particles are melted by the presence of the resin particles having different melting states, and the surface due to the melting of the particles By changing the effect of tension, the shape can be changed from a spherical shape to a potato shape or an indeterminate shape. If the difference between the softening points of the third resin particles and the first resin particles is less than 30 ° C., it is difficult to delay the state in which the melting of the core particles proceeds, and the shape adjustment tends not to proceed well. Conversely, if the difference in softening point between the third resin particles and the first resin particles exceeds 80 ° C., the aggregation of the core particles is difficult to proceed, and the third resin particles are difficult to be taken into the core particles. There are cases where the three resin particles remain in the aqueous system and white turbidity in the aqueous system remains.

  Further, as a preferable second characteristic of the third resin particle, when the weight average molecular weight in the gel permeation chromatogram of the third resin particle is Mwr3 and the weight average molecular weight of the first resin particle is Mwr1, Mwr1 × 1. The relationship of 5 ≦ Mwr3 ≦ Mwr1 × 12 is satisfied. Due to the presence of the third resin particles having a certain weight average molecular weight, in the agglomeration reaction in the course of the heat treatment, the state in which the melting of the core particles proceeds due to the presence of the resin particles having different melting states is delayed. It becomes possible to change from a spherical shape to a potato shape or an indeterminate shape. If the weight average molecular weight of the third resin particles is less than 1.5 times the weight average molecular weight of the first resin particles, it is difficult to delay the state in which the melting of the core particles proceeds, and the shape adjustment does not proceed well. There is a tendency. Conversely, if the weight average molecular weight of the third resin particles exceeds 12 times the weight average molecular weight of the first resin particles, the aggregation of the core particles is difficult to proceed, and the third resin particles are difficult to be taken into the core particles. The third resin particles tend to remain in the aqueous system and remain cloudy in the aqueous system.

  Moreover, it is preferable that the mixture ratio of the 3rd resin particle shall be 2-30 weight part with respect to 100 weight part of 1st resin particles. If it is less than 2 parts by weight, it is difficult to obtain the effect of shape adjustment. When it exceeds 30 parts by weight, the cohesiveness of the core particles is deteriorated, the third resin particles are not easily taken into the core particles, and the third resin particles tend to remain in the aqueous system and remain cloudy in the aqueous system. .

  The blending ratio of the third resin particles is also related to the softening point or the weight average molecular weight of the third resin particles. The higher the softening point or the weight average molecular weight, the smaller the blending amount.

  When Ts3 is Ts1 + 30 ° C. to Ts1 + 45 ° C., the blending ratio of the third resin particles is in the range of 22 to 30 parts by weight with respect to 100 parts by weight of the first resin particles, and when Ts3 is Ts1 + 45 ° C. to Ts1 + 65 ° C. The mixing ratio of the third resin particles is in the range of 12 to 22 parts by weight with respect to 100 parts by weight of the first resin particles. When Ts3 is Ts1 + 65 ° C. to Ts1 + 80 ° C., the mixing ratio of the third resin particles is However, the amount needs to be increased or decreased depending on the target shape with respect to 100 parts by weight of the first resin particles.

  When Mwr3 is Mwr1 × 1.5 to Mwr1 × 4, the blending ratio of the third resin particles is 22 to 30 parts by weight with respect to 100 parts by weight of the first resin particles, and Mwr3 is Mwr1. In the case of × 4 to Mwr1 × 8, the blending ratio of the third resin particles is in the range of 12 to 22 parts by weight with respect to 100 parts by weight of the first resin particles, and Mwr3 is Mwr1 × 8 to Mwr1 × 12. When the mixing ratio of the third resin particles is in the range of 2 to 12 parts by weight with respect to 100 parts by weight of the first resin particles, the amount needs to be increased or decreased depending on the target shape. There is.

  In the toner production method of the present invention, at least a first resin particle dispersion in which the first resin particles are dispersed and a third resin particle for adjusting the shape of the toner are dispersed in an aqueous medium. Three resin particle dispersions, a colorant particle dispersion in which colorant particles are dispersed, and a wax particle dispersion in which wax particles are dispersed are mixed, and a core particle dispersion containing core particles produced by aggregation is obtained. The second resin particle dispersion in which the second resin particles are dispersed is added, and the second resin particles are produced by a method of fusing the core particles to the core particles.

  As a preferable method for generating the core particles, a first resin particle dispersion in which the first resin particles are dispersed, and a third resin particle dispersion in which the third resin particles for adjusting the shape of the toner are dispersed. , Adjust the pH of the mixture dispersion, which is a mixture of the colorant particle dispersion in which the colorant particles are dispersed and the wax particle dispersion in which the wax particles are dispersed, under a certain condition, and add a certain amount of water-soluble inorganic salt. To do. Then, the first resin particle, the third resin particle, the colorant particle, and the wax particle are heated by heating the aqueous medium to the glass transition temperature (Tg) or higher of the first resin particle and / or the melting point of the wax or higher. Can be formed and core particles in which at least a part is melted can be produced.

  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 the range of 10.5 to 12.2, more preferably the pH is in 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 phenomenon that the formed core particles become coarse. In addition, by setting the pH value to 12.2 or less, there is an effect of suppressing generation of free wax particles and colorant particles and facilitating uniform encapsulation of wax and colorant.

  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.

  A glass-lined stainless steel (SUS) kettle as a preferred reaction kettle used for emulsion polymerization, mixing, and agglomeration is not particularly limited as a stirring blade for stirring the dispersion, but the width in the depth direction is not particularly limited. A wide blade shape (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, in an aqueous medium, a first resin particle dispersion, a third resin particle dispersion, a colorant particle dispersion, and a wax particle dispersion Are mixed to form a mixed dispersion. Then, this mixed dispersion is heated, and after the liquid temperature of the mixed dispersion reaches a certain temperature, a water-soluble inorganic salt is added as a flocculant to the mixed dispersion.

  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 aggregation reaction proceeds at once with the addition of the flocculant, and in a short time. Core particles can be generated. In addition, it is possible to form core particles with a small particle size and a narrow particle size distribution in which wax and colorant are uniformly encapsulated.

  Further, as described later, when waxes having different melting points are used in combination, the low melting point wax is first melted in the process of raising the temperature. Since melting starts and aggregation starts, this is an effective method for preventing the formation of aggregates 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 being widened and the shape distribution from becoming uneven.

  In the toner production method of the present invention, as a preferred embodiment of core particle generation, the first resin particle dispersion, the third resin particle dispersion, and the colorant particle dispersion are mixed and aggregated in an aqueous medium. The resin particles and the colorant particles are agglomerated to form core particles, and the core particle dispersion is mixed with the first resin particle dispersion liquid and the wax particle dispersion liquid. It is also preferable to produce core particles by aggregating the resin particles and wax particles.

  In an aqueous medium, a resin particle dispersion in which resin particles are dispersed and a colorant particle dispersion in which colorant particles are dispersed are mixed to form a mixed solution. After heating the mixed liquid and the liquid temperature of the mixed liquid reaches a certain temperature, a water-soluble inorganic salt is added to the mixed dispersion as a flocculant to agglomerate the resin particles and the colorant particles. Is generated. Thereafter, in a heated state, the resin particle dispersion and the wax particle dispersion are added to the core particle dispersion in which the core particles are generated, and the core particles, the resin particles, and the wax are aggregated to generate core particles. . By avoiding direct agglomeration with wax, the function of shape adjustment is more effectively exhibited.

  By adding the flocculant when the temperature of the mixed solution 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.

  In addition, the contact between the wax particles and the colorant particles is performed through the resin particles, so that the reaction between the resin particles and the colorant particles and the reaction between the resin particles and the wax particles is given priority. Each of the particles can be easily taken into the core particles uniformly, and core particles having a small particle size and a narrow particle size distribution in which wax and colorant are uniformly encapsulated can be formed.

  The core particle preferably has a structure in which a core particle portion obtained by aggregating resin particles and colorant particles and a mixed particle of resin particles and wax particles are fused to the surface of the core particles. By not exposing the colorant particles to the surface of the toner particles, the influence on the charging property can be minimized. By bringing the wax particles closer to the toner particle surface layer, the fixing property (non-offset temperature range) can be expanded. As will be described later, it is also preferable to fuse the second resin particles to the surface of the core particles.

  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 to add the mixture, the third resin particle dispersion, the colorant particle dispersion in which the colorant particles are dispersed, and the wax dispersion in which the wax particles are mixed.

  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 by adding an aqueous flocculant solution having a pH value with a certain relationship to the mixed dispersion, the core particles become coarse or the wax The phenomenon of non-uniform dispersion can be suppressed, which is effective.

  The mixed dispersion obtained by mixing the first resin particle dispersion, the third resin particle dispersion, the colorant particle dispersion, and the wax particle dispersion is subjected to heat treatment, and the mixed dispersion before the addition of the aqueous solution containing the flocculant When the pH value is HG, it is preferable that the pH value of the aqueous solution containing the flocculant is adjusted within the range of HG + 2 to HG-4. The range is preferably HG + 2 to HG-3, more preferably the range HG + 1.5 to HG-2, and still more preferably the range 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 core particles tend to become 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, it is more preferable that the pH value of the aqueous solution containing the flocculant is lower than the pH value of the mixed dispersion.

  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 core particle becomes coarse or the particle size distribution becomes broad.

  The timing of adding the flocculant is the DSC method described later, where the temperature of the mixed dispersion obtained by mixing the first resin particle dispersion, the third resin particle dispersion, the colorant particle dispersion, and the wax particle dispersion is mixed. It is preferable to add the flocculant after reaching the melting point of the wax measured by 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 temperature is adjusted to a specific temperature of a wax having a higher melting point. It is effective to add the flocculant in a temperature state where the melting of the wax particles is started.

  The total amount of the flocculant may be added all at once, but it is also preferable that the flocculant is dropped 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.

  It is preferable to add 1 to 50 parts by weight of the flocculant with respect to 100 parts by weight of the total of the first resin particles, the third resin particles, the pigment fine particles, and the wax fine particles. Preferably it is 1-20 weight part, More preferably, it is 5-15 weight part, More preferably, it is 5-10 weight part. If the amount is too small, the agglutination reaction does not proceed. If the amount is too large, the resulting particles tend to be coarse.

  In addition to the first resin particle dispersion, the third resin particle dispersion, the colorant particle dispersion, and the wax particle dispersion, the mixed dispersion is prepared by adding ion-exchanged water to adjust the solid concentration in the liquid. It doesn't matter. The solid concentration in the liquid is preferably 5 to 40% by weight.

  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% by weight.

  In addition, the first resin particle dispersion and the wax particle dispersion are added to the core particle dispersion in which the first resin particles, the core particles obtained by aggregating the third resin particles and the colorant particles are generated, and the core particles are added. In the example in which the first resin particles and the wax are aggregated to produce the core particles, the first resin particle dispersion, the third resin particle dispersion, and the colorant particle dispersion are used as the timing for adding the flocculant. It is also preferable to add the flocculant after the temperature of the mixed dispersion obtained by mixing the dispersion reaches the melting point of the wax measured by the DSC method described later.

  This is to increase the temperature of the aqueous medium above the melting point of the wax in order to promote the adhesion of the first resin particles and wax particles subsequently dropped after the formation of the core particles to the core particles without changing the temperature of the aqueous medium. When the wax is dripped, melting of the wax is started, aggregation of the melting wax particles, the first resin particles, and the core particles proceeds at a stretch, and the heat treatment is continued to further increase the core particles. The formation of core particles in which the first resin particles and the wax particles are aggregated progresses quickly, and particles having a small particle size and a narrow particle size distribution can be formed.

  When the core particles are produced by aggregating the first resin particles and the colorant particles, the agglomeration agent is added even when the flocculant is added when the temperature of the mixed dispersion reaches the glass transition point of the first resin particles. Is difficult to progress. When the temperature of the mixed dispersion reaches 80 ° C. or higher, the particles grow and the particles tend to grow to a particle size of 1 to 3 μm.

  Further, 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 temperature is adjusted to a specific temperature of a wax having a higher melting point.

  After adding the flocculant to form the first resin particles, the core particles where the third resin particles and the colorant particles are aggregated, the first resin particle dispersion and the wax particle dispersion are dropped, and the core particles And the first resin particles and wax particles are aggregated to produce core particles. It is preferable to continue the temperature of the aqueous medium at this time without changing.

  The first resin particles used for the core particles and the first resin particles used when the core particles are subsequently added together with the wax particles may be resins having different compositions and thermal characteristics, but they are the same. The first resin particles are preferred.

  When the total amount of the first resin particles contained in the core particles is 100, the first resin particles used for the core particles are preferably 30 to 80 by weight. By setting it to 30 or more, it is possible to generate a core particle having a small particle size and a narrow particle size distribution by aggregation of the first resin particles and the colorant particles. When it is less than 30, the dispersibility of the colorant particles tends to be lowered.

  The first resin particles and the wax particle dispersion are preferably dropped separately, or a dispersion previously mixed at a constant rate is preferably dropped at a constant dropping rate. If the total amount is added in a large amount, the temperature of the liquid may decrease, and aggregation may not progress uniformly.

  After dripping the predetermined amount of the first resin particles and the wax particle dispersion, the heat treatment is continued for a predetermined time. The time is preferably 10 minutes to 2 hours. Preferably, in 10 to 30 minutes, after mixing uniformly to some extent and keeping the temperature stable, the pH of the mixed solution in which the core particles, the first resin particles, and the wax particles are mixed is adjusted to 7 or more and 10 or less. To do. Thereby, adhesion of the 1st resin particle and wax particle to a core particle can be advanced. If the pH of the mixed solution is smaller than 7 or larger than 10, it becomes difficult to cause the first resin particles and wax particles to adhere to the core particles, and the core particles become coarse or the floating particles increase. It will be.

  After the pH adjustment, the heat treatment is continued for a predetermined time until a predetermined particle size and surface smoothness are obtained, whereby core particles are generated. The shape or surface smoothness of the core particles can be controlled by the heating time.

  The heating time is 0.5 to 5 hours, preferably 0.5 to 3 hours, more preferably 1 to 2 hours, whereby core particles having a predetermined particle size distribution are produced. 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.

  In 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. The toner base particles are produced by fusing the particles to the core particles.

  From the viewpoint of charging stability, it is desirable to form a fusion layer (sometimes referred to as a coating layer or a shell layer) on the core particles of the second resin particles. In addition, since resin particles with different softening points are present in the core particle as a shape adjustment, unevenness may occur on the particle surface, which may affect the chargeability and fluidity, so it is effective to provide a shell layer. It is.

  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, and 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.

  When 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 adjusted 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.

  The pH value of the second resin particle dispersion in which the second resin particles adjusted to the 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 in which the second resin particles are dispersed is higher than the pH value of the core particle dispersion in which the core particles are dispersed, that is, adjusted to be more alkaline and added. Is preferred. 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. Adhesion of particles can be promoted, generation of floating second resin particles not participating in fusion can be suppressed, and generation of secondary aggregation between core particles can be suppressed.

  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 The resin particles tend to remain in a floating state 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.

  When 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, it is preferable that 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. 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 is increased, the liquid temperature 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.

  The conditions under which the second resin particle dispersion is added dropwise are preferred so as to keep the fluctuation of the liquid temperature of the core particle dispersion in which the produced core particles are dispersed 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 heat-treat 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 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 amount of the polymerization initiator added is 100% monomer. 0.5 to 2.5 parts by weight with respect to parts by weight, 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 styrene monomer, (meth) It is preferable that the compounding quantity of the vinyl compound which has an acrylic acid ester monomer and an acid group-containing vinyl-type monomer and has an acid group shall be 0.1 to 5.0 weight% in a monomer.

  About the addition amount of a polymerization initiator, it exists in the tendency to influence aggregation of a 1st resin particle, a 3rd resin particle, a colorant particle, and a wax particle by the abundance of the hydrophilic group derived from a polymerization initiator. In other words, when the addition amount of the polymerization initiator is large, the aggregation reaction tends to proceed slowly, and when the addition amount of the polymerization initiator is small, the aggregation reaction tends to proceed earlier. 0.5 to 2.5 parts by weight per 100 parts by weight. 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 addition amount of the polymerization initiator is less than 0.5 parts by weight, the aggregation of the first resin particles proceeds quickly, and the first resin particles are aggregated without forming the core particles aggregated with the wax and the pigment. Coarse particles of the resin are produced. When the amount is more than 2.5 parts by weight, the aggregation of the core particles tends to be delayed, and it takes time 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 agglomeration reaction proceeds slowly due to the amount of hydrophilic groups derived from the polymerization initiator.

  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 agglutination 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 considered that the agglomeration is affected, whereby the dispersion state of the wax is fluctuated, the high temperature non-offset property is deteriorated, and the fixable temperature range is narrowed.

  In the present invention, the main component of the surfactant used when preparing the colorant particle or wax particle dispersion is preferably a nonionic surfactant. In this specification, a main component means 50 weight% or more.

  In the present invention, the first resin particle dispersion in which the first resin particles are dispersed, the third resin particle dispersion in which the third resin particles are dispersed, or the second resin particle dispersion in which the second resin particles are dispersed. The main component of the surfactant used for preparing the liquid is a nonionic surfactant, and the main component of the surfactant used for the colorant particle and wax particle dispersion is preferably a nonionic surfactant. .

  In the present invention, the first resin particle dispersion in which the first resin particles are dispersed, the third resin particle dispersion in which the third resin particles are dispersed, or the second resin particle dispersion in which the second resin particles are dispersed. Of the surfactants used for preparing the liquid, it is preferable that the nonionic surfactant has 50 to 95% by weight with respect to the entire surfactant. More preferably, it is 55 to 90 weight%, More preferably, it is 60 to 85 weight%.

  Moreover, it is preferable that nonionic surfactant has 50 to 100 weight% with respect to the whole surfactant among surfactant used for a coloring agent particle dispersion and a wax particle dispersion. More preferably, it is 60-100 weight%, More preferably, it is preferable to have 60-90 weight%.

  Among the surfactants used in the dispersion of each particle, the blending ratio of the ionic surfactant (preferably anionic surfactant) to the whole surfactant is such that wax particles, colorant particles, first resin particles, It is preferable to increase the order of the three resin particles.

  First, the first resin particles that use anionic surfactant in a large proportion start agglomeration to form nuclei, and then color that uses anionic surfactant in a larger proportion than wax particles The agent particles begin to aggregate around the core of the resin particles. Finally, it is presumed that the wax particles using the most nonionic surfactant are aggregated and aggregated so as to wrap the colorant particles together with the resin particles to form core particles. First, the first resin particles start to aggregate to form nuclei, but the colorant particles and wax particles are not taken into the core particles, and the colorant particles and wax particles that do not participate in aggregation remain in the core particle dispersion. This is considered to be a point to avoid the phenomenon.

  In the present invention, the surfactant used when preparing the first resin particle dispersion in which the first resin particles are dispersed and the third resin particle dispersion in which the third resin particles are dispersed is a nonionic surfactant. It is also preferable that the main component of the surfactant used in the wax particle dispersion and the colorant particle dispersion is only a nonionic surfactant.

  When such a resin particle, colorant particle, and wax particle are used and an aggregating agent is allowed to act in an aqueous medium, the resin particle starts to aggregate to form a nucleus. Next, the colorant particles begin to aggregate around the cores of the resin particles. Finally, the wax particles are aggregated, and the colorant particles are encapsulated with the resin particles. Resin particles are usually added several times or more in weight concentration as compared with colorant particles and wax particles, so that the core of the resin particles only aggregates on the wax particles and the outermost surface is covered with resin. Is estimated to be formed. It is considered that by this mechanism, the presence of floating colorant particles and wax particles that are not involved in aggregation in an aqueous system is eliminated, and core particles having a small particle size, a uniform and sharp particle size distribution can be formed. .

  In a mixed system of a nonionic surfactant and an ionic surfactant, and in the surfactant of the first resin particle dispersion and the third resin particle dispersion, the nonionic surfactant is added to the entire surfactant. On the other hand, it is preferably 50 to 95% by weight. More preferably, it is 55-90 weight%, More preferably, it is 60-85 weight%. By setting it to 50% by weight or more, it becomes easy to suppress the phenomenon that the particle size distribution of the generated core particles is widened. By making it 95% by weight or less, the dispersion of the resin particles themselves in the resin particle dispersion is easily stabilized. As the ionic surfactant, an anionic surfactant is preferable.

  Furthermore, in the colorant particles and wax particle dispersions dispersed only with the nonionic surfactant, the average ethylene oxide addition mole number of the nonionic surfactant used for wax particle dispersion is used for the colorant particle dispersion. It is preferable that it is larger than the average number of moles of added ethylene oxide of the nonionic surfactant. This is because the nonionic surfactant having a smaller average number of moles of added ethylene oxide tends to have higher cohesiveness with respect to the coagulant.

  The average number of moles of ethylene oxide added to the nonionic surfactant used for dispersing the pigment particles is preferably 18 to 33. More preferably, it is 20-30, More preferably, it is 20-26.

  If the average ethylene oxide addition mole number of the nonionic surfactant is smaller than 18, the cohesiveness of the pigment particles with respect to the coagulant becomes too high, and grows into large particles before being surrounded by the resin, and is incorporated into the toner particles. It will not be. On the other hand, when the average ethylene oxide addition mole number of the nonionic surfactant is larger than 33, the cohesiveness with respect to the flocculant becomes too low, and the carbon black fine particles do not aggregate and exist as fine particles in the reaction solution. As a result, the toner particles are not taken into the toner particles.

  It is also preferred that the nonionic surfactant used for dispersing the pigment particles contains a plurality of nonionic surfactants. By itself, even if the average ethylene oxide addition mole number of the nonionic surfactant is not in the range of 20 to 30, the weight average ethylene oxide addition mole number of the plurality of nonionic surfactants may be in the range of 20 to 30. 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.

  When such a resin particle, a colorant particle, and a wax particle are used and a flocculant is allowed to act in a solution, first, the resin particle using the anionic surfactant starts agglomeration to form a nucleus. Next, the colorant particles using the nonionic surfactant having a small average number of moles of added ethylene oxide begin to aggregate around the cores of the resin particles. Finally, wax particles using a nonionic surfactant having a large average number of moles of added ethylene oxide are aggregated and aggregated so as to wrap the colorant particles together with the resin particles to form core particles.

  It is possible to avoid a phenomenon in which the colorant particles and wax particles are not taken into the core particles and the colorant particles and wax particles that do not participate in aggregation in the core particle dispersion liquid remain.

  The amount of the nonionic surfactant relative to the pigment particles is preferably 10 to 20 parts by weight with respect to 100 parts by weight of carbon black in terms of dispersion stability.

  The main component of the surfactant used in the second resin dispersion is preferably a nonionic surfactant. Furthermore, it is also preferable that the surfactant used in the second resin particle dispersion is a mixture of a nonionic surfactant and an ionic surfactant. The nonionic surfactant is preferably 50 to 95% by weight based on the whole surfactant. More preferably, it is 55-90 weight%, More preferably, it is 60-85 weight%. By setting it to 50% by weight or more, adhesion of the second resin particle fine particles to the core particles can be promoted. By setting it to 95% by weight or less, there is an effect of stabilizing the dispersion of the resin particles themselves in the resin particle dispersion.

  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.

  Nonionic surfactants include, for example, 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.

  The softening point (Ts1) of the first resin particles constituting the core particles is preferably in the range of 80 ° C to 130 ° C. 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 less than 80 ° C., the agglomeration proceeds rapidly and it tends to be difficult to form particles having 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 exceeds 130 ° C., the low-temperature fixability tends to deteriorate.

  Moreover, it is preferable that the glass transition point of the 1st resin particle which comprises a core particle is 45 to 60 degreeC. 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 less than 45 ° C., the core particles are coarsened, and the storage stability and heat resistance tend to decrease. If it exceeds 60 ° C., the low-temperature fixability tends to deteriorate.

  The first resin particles have a weight average molecular weight (Mwr1) of 10,000 to 60,000 and a ratio Mwr1 / Mnr1 of the weight average molecular weight (Mwr1) to the number average molecular weight (Mnr1) of 1.5 to 6. preferable. More preferably, 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 preferably 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 exceeds 6, the shape of the core particle is not stable, tends to be indefinite, and unevenness remains on the particle surface, which tends to be inferior in surface smoothness.

  As described above, the first resin particles want to lower the softening point or the molecular weight as much as possible in order to improve the low-temperature fixability. It tends to be difficult. 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 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 50,000-. It is preferable that the ratio Mw / Mn of 500,000 and the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 2 to 10. More preferably, the glass transition point is 60 ° C to 70 ° C, the softening point is 145 ° C to 180 ° C, Mw is 80,000 to 500,000, and 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. Durability, high-temperature offset resistance, and separability can be improved by promoting thermal fusion of the core particle surfaces and setting the softening point higher.

  In addition, when the second resin particles constituting the shell are fused to the core particles blended with the third resin particles, there are different portions such as softening points in the core particles. In order to prevent non-uniformity, it is effective to have the above-mentioned constant glass transition point, softening point, or molecular weight characteristics. Further, even when the different shape becomes a potato shape or an indeterminate shape, it is effective to use the second resin particles having the above-mentioned characteristics in order to prevent the second resin particles from being unevenly adhered. is there.

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

  When the softening point of the second resin particles is less than 140 ° C., durability, high-temperature offset resistance, and separation between paper and the fixing roller tend to decrease. When it exceeds 180 ° C., the gloss and translucency tend to decrease.

  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 super HM-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 (first resin) particles is in the range of 80 to 130 ° C., and the softening points of the shape-adjusting resin particles (third resin) and the coating resin (second resin) particles are 140 to 180 respectively. It is preferably in the range of ° C. The same resin can be used for the shape-adjusting resin particles (third resin) and the coating resin (second resin) particles.

  The softening point of the binder resin is measured by a constant-load extrusion type capillary rheometer flow tester (CFT500) manufactured by Shimadzu Corporation.

First, a sample is filled in a cylinder, heated from the surroundings and melted, and a certain pressure is applied from above by a piston. The molten sample is extruded through a die having a narrow hole (diameter 1 mm, length 1 mm), and the fluidity of the sample, that is, the melt viscosity is determined from the flow rate (cm ³ / g).

  A heating furnace surrounding the cylinder and die is provided and set to 50 ° C. Fill the cylinder with 1 g of sample. Hold at 50 ° C. for 2.5 min without applying load. A load is applied to remove air from the sample. At this time, the length of the piston coming out of the heating furnace is set to about 12 to 15 mm. When the total holding time reaches 5 minutes, the temperature rise is started.

A load of 9.8 × 10 ⁵ N / m ² is applied to the piston and the piston is heated at a heating rate of 6 ° C./min. When the sample starts to melt, the downward movement of the piston begins. When the movement of the piston stops, the temperature rise and pressurization are stopped.

  At this time, the viscosity at each temperature can be measured from the relationship with the temperature rise temperature characteristic in the relationship between the moving amount of the descending piston and the temperature.

  FIG. 11 shows a flow curve. The horizontal axis shows the temperature, and the vertical axis shows the image of the piston movement. At the time of A, it is a solid state region of the sample, and as temperature rises thereafter, A to B are transition regions, where the sample is deformed by receiving a compressive load and the internal voids gradually decrease. B is a temperature at which the internal voids disappear and a single transparent body having a uniform appearance with a non-uniform stress distribution is obtained.

  B to C are regions where there is no clear change in the piston position within a finite time, and it is difficult for the sample to flow out of the die, and this region includes the rubbery elastic region of the sample.

  C is defined as a temperature at which the sample starts to flow (outflow start temperature (Tfb)) at a temperature at which the sample starts to flow and the piston starts to descend.

  The region from C to D through E is the flow region where the sample clearly flows out of the die, where E is the point where the sample has finished flowing out.

  The softening point of the binder resin is defined by the melting temperature in the 1/2 method (softening point Ts ° C.). Specifically, the softening point is defined as the temperature at which the piston moves 50% from the outflow start temperature with respect to the total movement distance of the piston from the outflow start temperature to the outflow end temperature.

  11, the temperature at which the piston starts to descend (temperature at which the sample flows) is first measured. This is the outflow start temperature (Tfb). The piston position at this time is read and made the minimum value (Smin).

  Thereafter, as the temperature rises, the sample continues to flow out of the die, and the temperature at the outflow end point E at which the outflow of the sample is completed and the position of the piston are read and set as the outflow end point (Smax).

  1/2 of the difference between the outflow end point (Smax) and the minimum value (Smin) is obtained (X = (Smax−Smin) / 2), and the temperature at the position of the point D where X and the minimum value Smin of the curve are added is calculated. calculate. This is the melting temperature (softening point Ts ° C.) in the 1/2 method.

  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. The temperature at the intersection with the indicated tangent.

  In order to measure the thermal characteristics 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 of extracting the solid content of the resin particles from this emulsion, it is carried out in the order along the toner aggregation step. 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 Low-temperature fixability, high-temperature non-offset properties, improved separation properties of transfer media such as copy paper on which toner melted at the time of fixing and heating rollers, etc., and fixing properties that conflict with storage stability, In order to improve the functionality, it is preferable to add a plurality of waxes.

  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.

  In the present invention, as a preferred first example of the wax, the wax contains at least the first wax and the second wax, and the endothermic peak temperature (referred to as the melting point Tsw1 (° C.)) of the first wax by the DSC method is 50. The endothermic peak temperature (melting point Tsw2 (° C.)) of the second wax by DSC method is set to 80 to 120 ° C. Storage stability will deteriorate that Tsw1 is less than 50 degreeC. If it exceeds 90 ° C, the low-temperature fixability and color glossiness will not be improved. Tsw1 is preferably 55 to 85 ° C, more preferably 60 to 85 ° C, and still more preferably 65 to 75 ° C. When Tsw2 is less than 80 ° C., the high temperature non-offset property and the paper separation property tend to be weakened. When the temperature exceeds 120 ° C., the cohesiveness of the wax decreases, and free particles that do not aggregate in the aqueous system tend to increase. Tsw2 is more preferably 85 to 100 ° C, and still more preferably 90 to 100 ° C.

  As a preferred second example of the wax, the wax contains at least a first wax and a second wax, and the first wax is at least a higher alcohol having 16 to 24 carbon atoms and a higher fatty acid having 16 to 24 carbon atoms. It is preferable that the ester wax comprises one and the second wax contains an aliphatic hydrocarbon wax.

  As a preferred third example of the 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, The wax preferably contains an aliphatic hydrocarbon wax.

  In preferred second and third examples of the wax, the endothermic peak temperature (melting point Tsw1 (° C.)) of the first wax by DSC method is 50 to 90 ° C., preferably 55 to 85 ° C., more preferably 60-85 degreeC, More preferably, it is 65-75 degreeC. When it is less than 50 ° C., the storage stability and heat resistance of the toner tend to deteriorate. When it exceeds 90 ° C., the cohesiveness of the wax decreases, and free particles that do not aggregate in the aqueous system increase. In addition, the low-temperature fixability and glossiness tend not to improve.

  Further, in the second and third examples preferable as the wax, the endothermic peak temperature (melting point Tsw2 (° C.)) of the second wax by DSC method is 80 to 120 ° C., preferably 85 to 100 ° C. Preferably it is 90-100 degreeC. When the temperature is less than 80 ° C., the storage stability tends to deteriorate, and the high temperature non-offset property and the paper separation property tend to be weak. When the temperature exceeds 120 ° C., the cohesiveness of the wax decreases, and free particles that do not aggregate in the aqueous system tend to increase. In addition, low-temperature fixability and color translucency tend to be hindered.

  In the preferred second or third example of the wax, when forming the core particles together with the resin particles, the colorant and the aliphatic hydrocarbon wax in the aqueous system, the aliphatic hydrocarbon wax is a resin because of its compatibility with the resin. Agglomeration tends to occur, and the presence of particles floating without wax being incorporated into the core particles or the aggregation of the core particles does not proceed 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. Further, when the shell is formed, a phenomenon that the core particles are coarsened tends to occur.

  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 of the aliphatic hydrocarbon wax with the resin is promoted and uniformly taken in, and the generation of suspended particles can be prevented. Furthermore, the first wax tends to be further improved in low-temperature fixability by partially compatibilizing with the resin. In addition, since the aliphatic hydrocarbon wax is less likely to be compatibilized with the resin, this wax can exert 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 preferred second or third example of the wax, as described in the preferred first example, when the toner particles are formed by aggregating a wax having a different melting point with a resin and a colorant in an aqueous system, In order to further promote the formation of particles having a small particle size and a narrow particle size distribution, and the formation of a shell that melts and attaches the second resin to the core particles, the first wax is used in the production of the wax particle dispersion. The second wax is preferably prepared by mixing, emulsifying and dispersing the first wax and the second wax, not separately. That is, the first wax and the second wax are heated and emulsified and dispersed in a constant blending ratio in the emulsifying and dispersing apparatus. 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.

  In the preferred first, second or third example of the wax, if the first wax weight ratio with respect to 100 parts by weight of the wax in the wax particle dispersion is ES1, and the second wax weight ratio is FT2, FT2 The relationship of / 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. When it exceeds 10, that is, when the weight ratio of the second wax is too large, low-temperature fixing cannot be realized, and the above-described 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 the preferred first, second or third examples of 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. As a result, the core particles become coarse and it is difficult to obtain particles having 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 preparation of core particles of these waxes with a resin and a colorant dispersion, wax is not liberated and particles having a small particle size and a narrow particle size distribution can be formed.

  In the preferred first, second or third example of 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 tend not to be exhibited. When the amount is more than 30 parts by weight, it tends to be difficult to control particles having a small particle diameter.

  In the preferred first, second or third example of the wax, Tsw2 is 5 ° C. or more higher than Tsw1 and preferably 50 ° C. or less. More preferably, the temperature is 10 ° C or higher, 40 ° C or lower, more preferably 15 ° C or higher, and preferably 35 ° C or lower. The function of the wax can be efficiently separated, and there is an effect of satisfying both low temperature fixing property, high temperature non-offset property and paper separation property. When the temperature is lower than 5 ° C., the effects of achieving both low-temperature fixability, high-temperature non-offset property, and poor paper separation tend to be difficult to achieve. When the temperature is higher than 50 ° C., the first wax and the second wax are likely to be phase-separated and tend not to be uniformly taken into the toner particles.

  A preferred first wax includes 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 coarse particle size, and makes it possible to produce toner base particles including 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, (1) 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, (2 ) 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, (3) montanic acid monoethylene glycol ester, ethylene glycol Distearate, monostearic glyceride, monobehenic acid glyceride, tripalmitic acid glyceride, pentaerythritol monobehenate, pentaerythritol dilinoleate, pentaerythritol trioleate or pentaerythritol tetrastearate Esters composed of higher fatty acids having 16 to 24 carbon atoms such as carbonate and polyhydric alcohols, or (4) diethylene glycol monobehenate, diethylene glycol dibehenate, dipropylene glycol monostearate, distearic acid diglyceride, tetrastearin Preferable examples include esters composed of a higher fatty acid having 16 to 24 carbon atoms such as acid triglyceride, hexabehenic acid tetraglyceride or decastearic acid decaglyceride and a polyhydric alcohol multimer. These waxes may be used alone or in combination of two or more.

  If the alcohol component and / or the acid component has less than 16 carbon atoms, the function as a dispersion aid is difficult to exhibit, and if it exceeds 24, the function as a low-temperature fixing aid tends to be difficult to exhibit.

  A preferred first wax 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. When the iodine value exceeds 25, the dispersion stability becomes 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. It tends to be distributed. When the saponification value is less than 30, the presence of unsaponifiable matter and hydrocarbons increases, and formation of uniform core particles having a small particle size tends to be difficult. If the saponification value exceeds 300, suspended matter in the aqueous system tends to 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 tends to be impaired. The particle size distribution of the generated toner tends to be 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 particle size distribution of the generated particles tends to be broad. Storage stability tends to deteriorate.

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 tends to be difficult to reduce the particle size of the generated particles when generating the emulsified dispersed particles.

  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 emulsified 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, a metal salt 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. 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 meadow foam oil fatty acid and a polyhydric alcohol such as glycerin, pentaerythritol, trimethylolpropane, etc., such as tolylene diisocyanate (TDI), diphenylmethane-4,4′-diisocyanate (MDI), etc. 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 emulsified 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 methyl, ethyl, butyl, glycerin, pentaerythritol, polypropylene glycol, trimethylolpropane and the like, and in particular, 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, an esterification reaction product of jojoba oil fatty acid and a polyhydric alcohol 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 chloride glacial acetic acid solution to chloroform or carbon tetrachloride solution of sample and titrate the remaining iodine without reaction with sodium thiosulfate standard solution to absorb iodine Calculate the amount.

  For the measurement of weight loss by heating, the weight of the sample cell is precisely weighed to 0.1 mg (W1 mg), 10 to 15 mg of the sample is put in this, and it is precisely 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 Co., Ltd., the heating rate is 10 ° C./min, the maximum temperature is 220 ° C., the holding time is 1 min, and the heating loss (weight%) = W3 / (W2−W1) × 100. It is done.

  Measurement of endothermic peak temperature (melting point Tsw ° C), onset temperature and endothermic amount by DSC method (differential scanning calorimeter measurement method) of wax, manufactured by TA Instruments, Q100 type (a genuine electric refrigerator is used for cooling) ), The measurement mode is “standard”, the purge gas (N2) 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 sample to be measured was placed in an aluminum pan as a sample amount of 10 mg ± 2 mg, and 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 shows the temperature of an empty aluminum crimp pan, the vertical axis shows the heat flow, the temperature at which the endothermic curve starts to rise from the baseline is the onset temperature, and the endothermic curve peak value is the endothermic peak temperature. (Melting point).

  In general, when measuring by the DSC method, in order to erase the thermal history of the sample, once the temperature is raised and cooled, the temperature is raised again and the endotherm at that time is measured. Since the structure was predicted to change, the heating process and cooling process for eliminating the thermal history were omitted.

  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 can be prevented, and toner base particles having a small particle size and a narrow particle size distribution can be generated.

  Oilless fixing having low temperature fixing, high glossiness, and translucency can be realized. In addition, the life of the developer can be extended along with the oilless fixing.

  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 and propylene glycol monostearate, and ethylene glycol fatty acid esters such as ethylene glycol monostearate and 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 esters, sorbitan monopalmitate, sorbitan monostearate, sorbitan tripalmitate, and 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, fatty acid hydrocarbon waxes such as polypropylene wax, polyethylene wax, polypropylene polyethylene copolymer wax, microcrystalline wax, paraffin wax, and Fischer-to-push wax can be suitably used.

  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, the 84% diameter (PR84) is 260 nm or less, and 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, the 84% diameter (PR84) is 220 nm or less, and PR84 / PR16 is 1.2 to 1.8. It is preferable that particles of 130 nm or less are 65 volume% or more, and particles exceeding 300 nm are 10 volume% or less.

  When the resin particle dispersion, the colorant particle dispersion, and the wax particle dispersion are mixed and aggregated to form aggregated particles, the 50% diameter (PR50) is 40 to 300 nm, and the wax is 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 the aggregated particles are heated in an aqueous system to obtain molten aggregated particles, 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.

  Particles with PR16 greater than 200 nm, 50% diameter (PR50) greater than 300 nm, PR84 greater than 400 nm, PR84 / PR16 greater than 2.0, less than 200 nm particles less than 65% by volume and greater than 500 nm When the amount exceeds 10% by volume, the wax is difficult to be taken in between the resin particles, and the agglomeration of only the waxes tends to occur frequently. In addition, particles that are not taken into the resin particles and float in water tend to increase. When the agglomerated particles are heated in an aqueous system to obtain fused agglomerated particles, the molten resin particles are less likely to include the melted wax particles, and the wax is less likely to be included in the resin. In addition, when the resin is adhered and fused, the amount of wax that is exposed and released on the surface of the toner base increases, filming on the photoconductor, increased spent on the carrier, handling characteristics during development, and development memory are generated. It tends to be easier.

  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.

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

  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 dispersion can be formed by a treatment time of about 30 seconds to 5 minutes.

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

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

  When the melting point of the wax is high, a molten liquid is prepared by heating in a high pressure state. Also, the wax is dissolved in an oily solvent. This solution is obtained by dispersing fine particles in water together with a surfactant 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 As a colorant (pigment) used in this embodiment, as a cyan pigment, C.I. I. Blue dyes and pigments of phthalocyanine and its derivatives such as Pigment Blue 15: 3 can be preferably used. Phthalocyanine pigments such as SANDYESUPERBLUE 1809 manufactured by the company can be preferably used.

  The yellow pigment is C.I. I. Acetoacetic acid arylamide monoazo yellow pigments such as C.I. Pigment Yellow 1, 3, 74, 97 or 98; I. Acetoacetic acid arylamide disazo yellow pigments such as C.I. Pigment Yellow 12, 13, 14, and 17; I. Solven Yellow 19, 77, 79 or C.I. I. Disperse Yellow 164 is blended, and C.I. I. Benzimidazolone pigments of CI Pigment Yellow 93, 180 and 185 are preferred.

  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.

  Carbon black can be suitably used as the black pigment. For example, # 52, # 50, # 47, # 45, # 45L, # 44, # 40, # 33, # 32, # 25, # 260, MA100S, # 40 manufactured by Mitsubishi Chemical Corporation, MOGULL manufactured by Cabot Corporation REGAL660R, REGAL500R, REGAL400R, REGAL330R, REGAL300R, REGAL250R, etc. can be preferably used.

  More preferably, carbon black having a DBP oil absorption (ml / 100 g) of 45 to 70 is preferred. Preferably it is 45-63, More preferably, it is 45-60, More preferably, it is 45-53.

  By using carbon black particles having a predetermined DBP oil absorption amount, the phenomenon of carbon black particles growing first can be suppressed, and even if the core particles are reduced in size, the carbon black particles are taken into the core particles. In addition, an effect of eliminating carbon black particles remaining without adding to the aggregation of core particles or core particles can be obtained. Although the reason is not clearly understood, it is presumed that carbon black larger than 70 is likely to cause aggregation of carbon black quickly, and the carbon black particles are not easily taken into the core particles or core particles.

  The particle size of carbon black is preferably 20 to 40 nm. The preferred particle size is 20 to 35 nm. The particle diameter is an arithmetic average diameter measured by an electron microscope. When the particle size is large, the coloring power tends to decrease. When the particle size is small, dispersion in the liquid tends to be 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 at a rate of 4 ml / min from the automatic burette. 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.

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

(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 and the like). 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 preferably, 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. Moreover, the said effect is show | played also by processing a fatty acid etc. 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.

  It is preferable that 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. 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. It is also preferable to externally add at least 0.5 to 3.5 parts by weight. 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 It is also preferable to externally add 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. 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 externally add.

  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 standing to cool 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) / Sample amount (g)] × 100
For ignition loss, about 1 g of a sample is placed in a magnetic crucible that has been dried, allowed to cool, and precisely weighed in advance, and weighed accurately. Ignite for 2 hours in an electric furnace set to 500 ° C. After standing to cool in a desiccator for 1 hour, its weight is precisely weighed and calculated from the following formula.
Loss on ignition (% 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%. In addition, toner particles having a particle size of 6.06 μm or more in the volume-based distribution are contained at 5% by volume or less, and volume percentage of toner particles having a particle size of 3.5 to 4.53 μm in the volume-based distribution is V34 When the number% of toner particles having a particle size 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 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, and toner particles having a particle size of 6.06 μm or more in the volume-based distribution are 0 .5% by volume or less, and P34 / V34 is 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 craving property by the rubber blade that progresses in the spherical shape is lowered, and when the irregular shape advances, the transfer property tends to be lowered.

  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 using a Coulter Counter TA-II type (Coulter Counter Co., Ltd.) by 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 by 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 determined by the following equation using a real surface view microscope (VE7800) manufactured by Keyence Corporation, measuring the maximum length and projected area of 100 toner base particles magnified 1000 times (d: toner particles) , A: projected area of toner particles, π is the circumference).
SC (shape index) = π · d ² / (4 · A)
The shape index will be described with reference to FIG. B in FIG. 19 is a perfect circle whose diameter is the maximum length d of the toner particles, and the area of the perfect circle B is π · (d / 2) ² . A in FIG. 19 is a projected area of toner particles. Since the shape index is represented by B / A, B / A = π · (d / 2) ² / A, and when this is arranged, π · d ² / (4 · A) is obtained.

(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 preferable 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 use, 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 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.

  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 structure in small machine It is intended to achieve both mold formation and printing speed. In order to realize a reduction in size that can process more than 20 sheets per minute (A4) and the machine can be used for SOHO applications, it is essential to shorten the interval between multiple toner image forming stations and increase the process speed. is there. In order to achieve both a reduction in size and a printing speed, the minimum value is considered to be 0.65 or less.

  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 of the present exemplary 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.

  Hereinafter, the present invention will be described more specifically with reference to examples. In addition, this invention is not limited to the following Example.

(1) 39.7mol% create terms of MnO carrier Preparation (a) a carrier CA1, 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 The mixture was pulverized for 10 hours, mixed, and dried, and then held at 950 ° C. for 4 hours to carry out calcination. This was pulverized with a wet ball mill for 24 hours, then granulated with a spray dryer, dried, and held in an electric furnace in an atmosphere of 2% oxygen concentration at 1270 ° C. for 6 hours to perform main 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 1) are methyl groups, that is, (CH ₃ ) ₂ SiO _2/2 units are 15.4 mol%, and R ₃ represented by (Chemical Formula 2) is a methyl group, A fluorine-modified silicone resin was obtained by reacting 250 g of polyorganosiloxane having 84.6 mol% of CH ₃ SiO _3/2 units with 21 g of CF ₃ CH ₂ CH ₂ Si (OCH ₃ ) ₃ . Further, 100 g of the fluorine-modified silicone resin in terms of solid content and 10 g of aminosilane coupling agent (γ-aminopropyltriethoxysilane) were weighed and dissolved in 300 cc of toluene solvent.

  Coating was performed on 10 kg of the ferrite particles by stirring the coating resin solution for 20 minutes using an immersion drying type coating apparatus. Thereafter, baking was performed at 260 ° C. for 1 hour to obtain carrier 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 characteristics of the resin particles obtained in the prepared resin particle dispersion (RL1, RL2, RL3, RH1, RH2, RH3, RH4, RH5, RH6). “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 the Z average molecular weight (Mz) to the 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.

(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 8 g of acrylic acid was added to 440 g of ion-exchanged water (Sanyo). Kasei Co., Ltd .: Nonipol 400) 7.2 g, anionic surfactant (Daiichi Kogyo Seiyaku, Neogen S20-F (20 wt% aqueous solution concentration)) 24 g (substantial anion amount 4.8 g), dodecanethiol 8 g were used. Then, 4.5 g of potassium persulfate was added thereto, and emulsion polymerization was performed at 78 ° C. for 3 hours. Thereafter, aging treatment was further performed at 90 ° C. for 4 hours to prepare a resin particle dispersion RL1 in which resin particles having a median diameter of 0.14 μm were dispersed. The pH of the resin dispersion at this time was 1.8.

  Table 2 shows the nonionic amount (g), the anionic amount (g), and the ratio (wt%) of the nonionic amount to the total surfactant amount used in each resin particle dispersion. In a liquid using an anionic surfactant (Daiichi Kogyo Seiyaku, Neogen S20-F (solid content 20 wt% concentration)), ion-exchanged water was adjusted so that the concentration was about 20 wt%. The weight ratio in Table 2 indicates the actual anion amount ratio.

  Tables 3 and 4 show the blending amounts of acrylic acid, potassium persulfate and the like 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. Potassium persulfate indicates parts by weight based on 100 parts by weight of the monomer component.

(3) Preparation of Pigment Dispersion Table 5 and Table 6 show the pigments that are colorants used and the surfactants used.

(A) Preparation of Pigment Particle Dispersion PCS1 In a 1 L beaker, 308 g of ion exchange water and 12 g of surfactant SA3 were weighed and stirred with a magnetic stirrer until the solid content of the surfactant was dissolved. 80 g of cyan pigment particles PC1 were added to this aqueous surfactant solution, and further stirred 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 pigment particle dispersion PCS1. The pigment concentration was 20% by weight.

  Hereinafter, based on the adjustment conditions of the cyan pigment particle dispersion PCS1, black pigments, magenta pigments, yellow pigments used for the respective black pigment dispersions CBS1, 2, 3, magenta pigment dispersion PMS1 and yellow pigment dispersion PYS1 Table 7 shows the conditions of the surfactants.

(4) Preparation of Wax Dispersion Table 8, Table 9 and Table 10 show the wax materials and their properties used in the preparation of the wax particle dispersion according to this example formed as preparation examples of the wax particle dispersion. .

(A) Preparation of Wax Particle Dispersion WA1 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 treated, and a hole is formed in the center 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 a high speed. A hole of about 1 to 5 mm is formed on the side surface of the rotating body, and the liquid to be processed can be moved. The tank is 120 ml, and about half of the liquid to be treated is charged. The speed 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 for high-pressure processing or batch processing.

  The inside of the tank was charged with 67 g of ion-exchanged water, 3 g of a nonionic surfactant (manufactured by Sanyo Kasei Co., Ltd .: Elminol NA400), 30 g of wax (W-1), and the speed of the rotating body was 30 m / s for 5 min, and then the rotational speed was increased to 50 m / s for 2 min. A wax particle dispersion WA1 was formed.

  Tables 11 and 12 show the types and characteristics of the waxes used and the surfactants used for each wax particle dispersion wax particle dispersion (WA1 to WA12) based on the adjustment conditions of the wax particle dispersion WA1. . “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. Represents.

  In a liquid using an anionic surfactant (Daiichi Kogyo Seiyaku, Neogen S20-F (20 wt% concentration)), ion-exchanged water was adjusted so that the pigment concentration was about 20 wt%. The weight ratio in the table indicates the actual anion amount ratio, and the total amount is the same amount. 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) Preparation of toner base CT2 Table 13 shows toner bases (CT2, CT3, CT4) according to examples of the present invention prepared as toner base preparation examples and toner bases for comparison ( The respective compositions are shown for ct1, ct5).

  156 g of the first resin particle dispersion RL1 and 48 g of the third resin particle dispersion RH2 as a shape control in a cylindrical 2 L glass container equipped with a thermometer, a cooling pipe, a pH meter, and a stirring blade, a colorant 56 g of particle dispersion PCS1 and 60 g of wax particle dispersion WA11 were added, 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 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 3 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 toner base thus obtained was dried at 35 ° C. for 8 hours by a fluid drier to obtain toner base CT2.

  For toner bases ct1, CT3, CT4, and ct5, the third resin particles were changed based on the conditions of CT2, and the agglomeration of the particles was observed.

  Table 14 shows the characteristics obtained in the toner base prepared. A difference in Ts indicates a difference in softening point Ts3 between the first resin Ts1 and the third resin, and a difference in Mw indicates a value obtained by dividing Mwr3 of the third resin by Mwr3 of the first resin. 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. 2.0 to 3.63 (p%) is the content of toner particles having a particle size of 2.0 to 3.63 μm in the number-based distribution, and over 6.06 μm (v%) is a particle of 6 μm or more in the volume-based distribution. The content of toner particles having a diameter, SC × d50 (μm), is a value obtained by multiplying the shape index and the volume average particle diameter.

  In the ct1 toner, the aggregation of the core particles proceeds rapidly, so the pH of the mixed dispersion is set to 10.5. In the ct5 toner, the progress of aggregation of the core particles is slow, and the liquid is not completely transparent even after 6 hours. Also, the shape remains fairly irregular. It seems that suspended particles that do not participate in the aggregation of wax or resin particles remain.

  The SEM observation image of the shape of the ct1 toner is shown in FIG. 12, the SEM observation image of CT2 is shown in FIG. 13, the SEM observation image of CT4 toner is shown in FIG. 14, and the SEM observation image of ct5 toner is shown in FIG. CT2, CT3, and CT4 toners showed good cohesiveness and obtained a toner base having a small particle size and a narrow particle size distribution. In the sample in which the softening point of the third resin is increased, the shape tends to shift from spherical to potato.

(B) Preparation of toner base CT7 Table 15 shows toner bases (CT7, CT8, CT9, CT10) and toner bases (ct6, ct11) for comparison according to examples of the present invention prepared as toner base preparation examples. Each composition is shown.

  To a 2000 ml four-necked flask equipped with a thermometer, a cooling tube, a stirring rod, and a pH meter, 169 g of the first resin particle dispersion RL2, 35 g of the third resin particle dispersion RH2, and the colorant particle dispersion PCS1 56 g and 45 g of wax particle dispersion WA10 were added, 350 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 11.0 and stirred for 10 minutes. Thereafter, when the temperature was increased from 20 ° C. at a rate of 1 ° C./min and reached 80 ° C., 200 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. The temperature was raised to 90 ° C. and heat treatment was performed for 3 hours to obtain core particles. The obtained core particle dispersion had a pH of 8.7.

  Thereafter, 105 g of the second resin particle dispersion RH3 whose pH was adjusted to 9.4 was 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. Thereafter, the obtained toner base was dried at 40 ° C. for 6 hours with a fluid dryer to obtain toner base CT7.

  For toner bases ct6, CT8, CT9, CT10, and ct11, the third resin particles were changed based on the conditions of CT7, and the cohesiveness of the particles was observed.

  Table 16 shows the characteristics obtained in the toner base prepared.

  In the ct6 toner, the aggregation of the core particles proceeds rapidly, so the pH of the mixed dispersion is set to 10.5. In the ct11 toner, the progress of aggregation of the core particles is slow, and the liquid is not completely transparent even after 6 hours. Also, the shape remains fairly irregular. It seems that suspended particles that do not participate in the aggregation of wax or resin particles remain.

  FIG. 16 shows an SEM observation image of CT7, FIG. 17 shows an SEM observation image of CT8 toner, and FIG. 18 shows an SEM observation image of ct11 toner. In the CT7, CT8, CT9, and CT10 toners, toner bases exhibiting good cohesion and having a small particle size and a narrow particle size distribution were obtained. In the sample in which the softening point of the third resin is increased, the shape tends to shift from spherical to potato.

(C) Preparation of toner matrix CT13 Table 17 shows the compositions of the toner matrix (CT13, CT14, CT15) and the toner matrix (ct12) for comparison according to the embodiment of the present invention, which were created as examples of the toner matrix. Show.

  For toner bases ct12, CT13, CT14, and CT15, the third resin particles were changed based on the conditions of CT2, and the cohesiveness of the particles was observed.

  Table 18 shows the characteristics obtained in the toner base prepared.

  In the case of ct12 toner, the aggregation of the core particles progresses quickly, so the pH of the mixed dispersion is set to 11.

  CT13, CT14, and CT15 toners showed good aggregation properties. In the sample in which the softening point of the third resin is increased, the shape tends to shift from spherical to potato.

(D) Preparation of Toner Base CT17 Table 19 shows the compositions of the toner base (CT17, CT18) and the comparative toner bases (ct16, ct19) according to the examples of the present invention prepared as toner base preparation examples. Show.

  To a 2000 ml four-necked flask equipped with a thermometer, a condenser, a stirring rod, and a pH meter, 174 g of the first resin particle dispersion RL2, 30 g of the third resin particle dispersion RH3, and the colorant particle dispersion PCS1 56 g and 70 g of wax particle dispersion WA9 were added, 350 ml of ion exchange water was added, and the mixture was mixed for 10 min 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 11.0 and stirred for 10 minutes. Thereafter, when the temperature was raised from 20 ° C. at a rate of 1 ° C./min and reached 90 ° C., 200 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 92 ° C. for 3 hours to obtain core particles. The obtained core particle dispersion had a pH of 8.4.

  Thereafter, 85 g of the second resin particle dispersion RH5 having a pH adjusted to 8.9 with a water temperature of 92 ° C. was added at a dropping rate of 5 g / min. Thus, particles in which the second resin particles were fused were obtained.

  For toner bases ct16, CT18, and ct19, the third resin particles were changed based on the conditions of CT17, and the cohesiveness of the particles was observed.

  Table 20 shows the characteristics obtained in the toner base prepared.

  In the case of ct16 toner, the aggregation of the core particles progresses quickly, so the pH of the mixed dispersion is set to 11.

  In CT17 and CT18 toners, toner bases exhibiting good cohesion and having a small particle size and a narrow particle size distribution were obtained. In the sample in which the blending amount of the third resin is increased, the shape tends to shift from spherical to potato as the amount increases. However, if the blending amount is increased too much, the core particle aggregation proceeds slowly in the ct19 toner, and the liquid is not completely transparent even after 6 hours.

(E) Preparation of toner base CTw20 For toner bases CTw20, CTw21, CTw22, CTw23, CTw24, CTw25, and CTw26, based on the conditions of CT17, the wax dispersion to be added was changed, and the agglomeration property of the particles was observed.

  Table 21 shows the respective compositions of toner bases (CTw20, CTw21, CTw22, CTw23, CTw24, CTw25, CTw26) according to the examples of the present invention, which are prepared as toner base preparation examples.

  Table 22 shows the characteristics obtained in the toner base prepared.

  There is a tendency to influence the shape depending on the melting point of the wax used. As an agglomeration method, it seems that the effect tends to appear when the resin particles, the colorant, and the wax are mixed, heated, and the aggregating agent is added after reaching a certain temperature. It is considered that the influence of the wax is likely to appear by adding a flocculant and allowing the agglutination reaction to proceed while a part of the resin and wax is melted.

  When a hydrocarbon wax having a high melting point of 85 to 98 ° C. is blended, the shape tends to shift from a spherical shape to a potato shape and an indefinite shape. When a hydrocarbon wax having a melting point higher than 100 ° C. is blended, the shape becomes indefinite, and the agglomeration does not proceed in part and tends to remain cloudy. Further, it seems that the shape of the low melting point ester wax of 68 to 85 ° C. tends to be slightly spherical.

(6) External additive Next, examples of the external additive will be described. Table 23 shows the respective materials and characteristics of the external additives (S1, S2, S3, S4, S5, S6, S7, S8, S9) used in this 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 a 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 24 shows toners (TCT2 to TCT4, TCT7 to TCT10, TCT12 to TCT14, TCT17 to TCT18, TCT20 to TCT26) and toners for comparison (tct1, tct5, The material composition of each of tct6, tct10, tct11, tct15, tct16, and tct19) is shown. 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. The external addition process was performed in a Henschel mixer FM20B (Mitsui Mining Co., Ltd.) with a stirring blade Z0S0 type, a rotational speed of 2000 min ⁻¹ , a processing time of 5 min, and an input amount of 1 kg.

  Other black toner, magenta toner, and yellow toner used CBS2, PMS1, and PYS1 as pigments, and other compositions were the same as those of the cyan toner composition.

  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. When the resistance value is smaller than 10 ² Ω, retransfer is likely to occur. Larger transfer defects are more likely to occur than 10 ⁶ Ω. If it is less than 1.0 (N), transfer defects occur, and if it is greater than 9.8 (N), transfer character omission occurs.

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

  Four sets of image forming units 18Y, 18M, 18C, and 18K for each color of yellow (Y), magenta (M), cyan (C), and black (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 mixing ratio of the carrier and the toner is read by a magnetic permeability sensor (not shown) and supplied from a toner hopper (not shown) at an appropriate time. Reference numeral 5 denotes a metal magnetic blade that 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, and 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 against each other. 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 is made of 30 μm Ni as a substrate, silicone rubber is 150 μm thereon, and PFA tube 30 μm is overlaid thereon.

  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 ° C. using a thermistor.

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

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

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

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

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

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

(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 25 shows the two-component developers (DCT2 to DCT4, DCT7 to DCT9, DCT12 to DCT14, DCT17 to DCT18, DCT20 to DCT26) used in this example and the comparative examples. For each of the agents (dct1, dct5, dct6, dct10, dct15, dct16, dct19), the composition of the toner and carrier as a two-component developer, and the results of evaluating and evaluating 100,000 sheets running durability test on A4 size paper Show. In the table, “A” is very good, “B” is good, “C” is somewhat problematic, and “D” is problematic.

  The two-component developers DCT2 to DCT4, DCT7 to DCT9, DCT12 to DCT14, DCT17 to DCT18, and DCT20 to DCT26 according to the embodiments of the present invention are on the photoreceptor when the 100,000 sheets running durability test is performed on A4 size paper. As for toner filming, the level of practically no problem. In addition, toner filming on the transfer belt was at a level causing no practical problem. Further, no cleaning failure of the photoconductor and the transfer belt occurred. Even in a full-color image in which the three colors overlap, no paper wrapping around the fixing belt occurred.

  Further, regarding the image density before and after the running test, the two-component developers according to the examples of the present invention all obtained high-density images having an image density of 1.3 or more. Even after the endurance test of 100,000 sheets of A4 stencil, the fluidity of the two-component developer was stable, and the image density showed stable characteristics with little change of 1.3 or more.

  In addition, regarding the non-image area fogging and the entire surface solid image uniformity, the two-component developers according to the examples of the present invention have no high image density, no non-image area fogging, and no toner scattering. , High resolution. Further, the uniformity when taking the entire solid image at the time of development was also good.

  In addition, no abnormal image of the vertical streak occurred even during continuous use. Further, the spent component of the toner component on the carrier hardly occurred. In addition, there is little change in carrier resistance and a decrease in charge amount. In addition, the rise of charge is good when toner is rapidly replenished by continuously taking a solid image, and the phenomenon that fog increases in a high humidity environment is also observed. I couldn't. Moreover, even in long-term use, a high saturation charge amount could be maintained for a long time. Moreover, there was almost no change in the charge amount under low temperature and low humidity.

  Further, with regard to transferability (character skip during transfer, reverse transfer, and transfer omission), the two-component developers according to the examples of the present invention were at a level where there was no practical problem with omission. In addition, no transfer failure occurred even in a full-color image in which the three colors overlapped. The transfer efficiency was about 95%.

  In terms of fog and character skipping during transfer, DCT3, DCT7 to DCT9, DCT13 to DCT14, DCT17 to DCT18, and DCT20 to DCT24 are particularly better.

  Even if the mixing ratio of the toner and the carrier is changed to 5 to 20% by weight, the two-component developer according to the embodiment of the present invention has little change in image quality such as image density and ground fogging, and can control the toner density widely. Became possible.

  On the other hand, the two-component developer (dct5, dct10, dct15, dct19) for comparison causes toner filming on the photoreceptor in the running durability test. In addition, the image density before and after the running test is low, the image density is lowered after long-term use, or the fog in the non-image area tends to increase. Further, when the entire surface was continuously taken and the toner was replenished rapidly, the charge decreased and the fog increased. In particular, the phenomenon worsened in a high humidity environment. This is probably due to the influence of wax particles and resin particles that do not participate in the aggregation reaction.

  In the two-component developer (dct1, dct6, dct11, dct16) for comparison, a cleaning failure on the photoconductor occurred in the running test.

Next, Table 26 shows the evaluation results for the fixing property, non-offset property, high-temperature storage stability, and paper wrapping property around the fixing belt in a full-color image. In the table, “G” indicates that the evaluation result is good, and “F” indicates that there is a problem. Here, 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 not coated with oil, OHP film transmittance (fixing temperature 160 ° C.) and minimum fixing temperature And the temperature at which the offset phenomenon occurred at high temperature was measured. Further, in the storage stability test at a high temperature, the state of the toner after being left at 50 ° C. for 24 hours was evaluated. The film transmittance for OHP was measured with a spectrophotometer U-3200 (Hitachi, Ltd.) for the transmittance of 700 nm light.

  The toners TCT2 to TCT4, TCT7 to TCT9, TCT12 to TCT14, TCT17 to TCT18, and TCT20 to TCT21 according to the embodiments of the present invention have good OHP film transmittance of 70% or more. Met. As for non-offset properties, a non-offset temperature range can be obtained over a wide range of 140 to 200 ° C. or more in a fixing roller that does not use oil, and the fixing temperature range (the range from the lowest fixing temperature to the temperature at which high temperature offset phenomenon occurs). ) Was wide. The offset phenomenon did not occur even with 200,000 full-color images of plain paper. Further, the surface deterioration phenomenon of the belt was not observed even if the oil was not applied with a silicone resin or fluororesin fixing belt. In addition, regarding the high-temperature storage stability, almost no aggregation was observed in the storage stability at 50 ° C. for 24 hours. In addition, as for the winding property of the paper around the fixing belt, jamming of the OHP film at the fixing nip portion did not occur.

  For comparison toners tct5, tct10, tbt15, and tbt19 toners, the high temperature non-offset property was weak and the margin of the fixable region was narrow. This seems to be due to the influence of wax particles and resin particles that do not participate in aggregation during the aggregation reaction.

[Document Name] Description
Patent application title: TONER AND METHOD FOR PRODUCING TONER
【Technical field】
[0001]
The present invention relates to a toner used in a copying machine, a laser printer, plain paper FAX, a color PPC, a color laser printer, a color FAX, and a complex machine thereof, and a toner manufacturing method.
[Background]
[0002]
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 that realizes miniaturization, high speed, high image quality, and maintenance-free. Therefore, a cleaner-less process that collects waste toner during development without cleaning waste toner remaining after transfer in electrophotography, a tandem color process that enables high-speed output of color images, and fixing to prevent offset during fixing Oil-less fixing that achieves both high glossiness and high translucency, a clear color image and non-offset properties without using oil, 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.
[0003]
In a color printer or the like, in a fixing process, it is necessary to melt and mix color toners in a color image to improve translucency. When toner melting 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 is deteriorated. Therefore, it is a necessary condition that the toner has a melting characteristic that dissolves quickly and has a light-transmitting property that does not disturb the color tone.
[0004]
When a color image is obtained, toner adheres to the surface of the fixing roller to cause an offset, so that a large amount of oil or the like must be applied to the fixing roller, which complicates handling and the configuration of the device. For this reason, in order to reduce the size, maintain maintenance, and reduce the cost of the equipment, it is required to realize oilless fixing that does not use oil during fixing, which will be described later. In order to make this possible, it is becoming practical to add a release agent such as wax into a binder resin having sharp melt characteristics.
[0005]
However, since the toner has such a characteristic that the toner cohesion is strong, the tendency of toner image disturbance and transfer failure during transfer is more prominent, making it difficult to achieve both transfer and fixing. When used as two-component development, the low melting point component of the toner adheres to the surface of the carrier due to collision between particles, friction, mechanical collision such as collision between particles and developer, friction, etc., or heat generated by friction. Spent is likely to occur, which lowers the charging ability of the carrier and hinders the long life of the developer.
[0006]
Various proposals have been made for toner. As is well known, the toner for electrostatic charge development used in the electrophotographic method is generally a resin component which is a binder resin, a coloring component consisting of a pigment or a dye, a plasticizer, a charge control agent, and further if necessary. It is comprised by additional components, such as a mold release agent. As the resin component, natural or synthetic resins may be used alone or mixed in a timely manner.
[0007]
Then, the above additives are premixed at an appropriate ratio, heated and kneaded by heat melting, finely pulverized by an airflow type impact plate method, and finely classified to complete a toner base. There is also a method in which a toner base is prepared by a chemical polymerization method. Thereafter, an external additive such as hydrophobic silica is added to the toner base to complete the toner. In one-component development, the toner is composed only of toner, but a two-component developer can be obtained by mixing with toner and a carrier composed of magnetic particles.
[0008]
However, in the conventional pulverizing / classifying operation in the kneading and pulverizing method, the particle size that can be actually provided economically and in performance is about 8 μm even if the particle size is reduced. At present, methods for producing small-diameter toners by various methods are being studied. In addition, a method for realizing oil-less fixing by blending a release agent such as wax in a low softening resin during melt kneading of the toner has been studied. However, there is a limit to the amount of wax that can be blended, and as the amount added increases, adverse effects such as a decrease in toner fluidity, an increase in voids during transfer, and the occurrence of filming on the photoconductor occur. Moreover, the surface state of the pulverized particles is uneven, and it is difficult to control the surface smoothness.
[0009]
Therefore, a toner production method using various polymerization methods different from the kneading and pulverization method has been studied. For example, when a toner is prepared by a suspension polymerization method, it is difficult to control the particle size distribution of the toner, and a classification operation may be required in order to generate particles having a narrow particle size distribution. Further, since the toner obtained by this method has a substantially spherical shape, there is a problem that the cleaning performance of the toner remaining on the photoconductor and the like by the cleaning blade is poor and the image quality reliability is impaired.
[0010]
In addition, a toner preparation method using an emulsion polymerization method is a method of preparing an aggregated particle dispersion by forming aggregated particles in a dispersion obtained by dispersing at least resin particles and colorant particles. Further, a resin fine particle dispersion obtained by dispersing resin fine particles is added to the resin particles, and the resin fine particles are attached to the aggregated particles, and then heated and fused.
[0011]
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. It is disclosed that a coating layer made of fine particles is formed on the surface of a particle by changing the pH of the composition and solution for forming the coating layer made of particles.
[0012]
In the following Patent Document 2, the release agent contains at least one ester composed of at least one of a higher alcohol having 12 to 30 carbon atoms and a higher fatty acid having 12 to 30 carbon atoms, and the resin particles have a molecular weight. It is disclosed that by including at least two different types of resin particles, it is excellent in fixing property, coloring property, transparency, color mixing property and the like.
[0013]
In Patent Document 3 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, the amount of colorant present on the particle surface is small, and even when subjected to long-term image formation in a high-humidity environment, changes in image density, fogging, and color changes due to changes in chargeability and developability The effect which does not generate | occur | produce is described.
[0014]
In Patent Document 4 below, in an electrostatic charge image developing toner including toner particles containing at least a resin and a colorant, the toner particles include a core containing resin A and at least one layer of resin B covering the core. A toner having a shell containing the toner and having a film thickness of 50 nm to 500 nm on the outermost surface layer of the shell is disclosed, and the effect of the toner for developing an electrostatic charge image having excellent offset resistance and good storage stability Is described.
[0015]
Patent Document 5 below discloses a toner having a shape factor of 100 to 137, forms an aggregate particle dispersion of resin fine particles and a colorant, and the obtained aggregate particle dispersion is used as a glass transition temperature ( Tg) or more, preferably Tg to Tg + 10 ° C. The temperature is increased to a temperature range of Tg to Tg + 10 ° C., for example, after the aggregate particles are grown to the desired toner particle diameter over 2 hours, the aggregation is stopped and further It is disclosed that the toner particles having a shape factor of 100 to 137 are formed by heating to the same temperature and fusing and coalescing the surfaces of the aggregate particles within 10 hours.
[0016]
In the following Patent Document 6, the shape index SF1 = 125 to 140 (where SF1 = (π / 4) × (L ² / A) × 100, L is maximum length, A represents projected area), cumulative volume average particle diameter D _50V = 3 to 7 μm toner is disclosed, and at least one resin particle dispersion and at least one colorant dispersion are mixed, and after adding an aggregating agent to form aggregated particles, A manufacturing method is disclosed in which toner particles are manufactured by fusing the aggregated particles by heating to a temperature above the glass point.
[Prior art documents]
[Patent Document 1] Japanese Unexamined Patent Publication No. 57-45558
[Patent Document 2] JP-A-10-301332
[Patent Document 3] Japanese Patent Application Laid-Open No. 2002-116574
[Patent Document 4] Japanese Unexamined Patent Application Publication No. 2004-191618
[Patent Document 5] Japanese Patent Application Laid-Open No. 2000-131876
[Patent Document 6] Japanese Patent Laid-Open No. 2000-267331
SUMMARY OF THE INVENTION
[Problems to be solved by the invention]
[0017]
The shape of the toner tends to be determined from the relationship with the image forming process such as development, transfer, and cleaning process, and the toner shape has a larger shape index when the cleaning property of the photoreceptor or transfer belt is important. The potato-like shape increases the margin for cleaning. When emphasizing transferability, the toner shape is made closer to a sphere with a small shape factor to increase the transfer efficiency. Accordingly, it is important to be able to arbitrarily control the shape index in order to ensure a design margin for the image forming process.
[0018]
Conventionally, it has been disclosed that the shape is adjusted by adjusting the temperature and time when aggregated particles are generated. However, the adjustment of the temperature tends to cause a variation in the particle size distribution, making it difficult to adjust the shape and the particle size distribution. Moreover, adjusting according to the processing time also tends to cause fluctuations in the particle size distribution, affects the surface smoothness of the particles, and may also affect the productivity. As described above, regarding the setting of the shape factor within the set value, the description of the specific method is not sufficient, and it cannot be said that the correlation between the condition of the method and the shape index is sufficiently obtained.
[Means for Solving the Problems]
[0019]
The present invention can appropriately control the shape of the particles without affecting the particle size distribution and the surface smoothness of the particles, and can produce a small-sized toner having a narrow particle size distribution without a classification step. Objective.
[0020]
In addition, in oilless fixing without using oil in the fixing roller, a release agent such as wax is used in the toner to achieve low temperature fixing property, high temperature non-offset property, paper separating property from the fixing roller, etc. and high temperature state. The object is to achieve both storage stability during storage.
[0021]
In addition, an image forming apparatus is provided which can prevent high-efficiency by preventing omission and scattering during transfer.
[0022]
The toner of the present invention is a toner containing toner base particles and an external additive, and the toner base particles are at least binder resin particles as first resin particles and third resin particles in an aqueous medium. Fusing the coated resin particles, which are the second resin particles, to the core particles produced by aggregating the shape-adjusting resin particles for adjusting the shape of the toner, the colorant particles and the wax particles, The softening point of the shape-adjusting resin particles and the coating resin particles is higher than the softening point of the binder resin particles.
[0023]
The toner manufacturing method of the present invention is a toner manufacturing method including toner base particles and an external additive, wherein the toner base particles are at least a first resin in which binder resin particles are dispersed in an aqueous medium. A particle dispersion, a third resin particle dispersion in which resin particles for adjusting the shape of the toner are dispersed, a colorant particle dispersion in which colorant particles are dispersed, and a wax particle dispersion in which wax particles are dispersed. Mixing the liquid and aggregating to produce core particles, and adding the second resin particle dispersion in which the coated resin particles are dispersed to the core particle dispersion containing the generated core particles; And a step of fusing the second resin particles to the core particles.
[Brief description of the drawings]
[0024]
FIG. 1 is a schematic cross-sectional view showing the configuration of an image forming apparatus used in an embodiment of the present invention.
FIG. 2 is a schematic cross-sectional view showing a configuration of a fixing unit used in an embodiment of the present invention.
FIG. 3 is a schematic perspective view of a stirring and dispersing apparatus used in an example of the present invention.
FIG. 4 is a schematic plan view of a stirring and dispersing apparatus used in an example of the present invention.
FIG. 5 is a schematic cross-sectional view of a stirring and dispersing apparatus used in an example of the present invention.
FIG. 6 is a schematic plan view of a stirring and dispersing apparatus used in an example of the present invention.
FIG. 7 is a schematic perspective view of a stirring and dispersing apparatus used in an example of the present invention.
FIG. 8 is a schematic plan view of a stirring and dispersing apparatus used in an example of the present invention.
FIG. 9 is a schematic perspective view of a stirring and dispersing apparatus used in an example of the present invention.
FIG. 10 is a schematic plan view of a stirring and dispersing apparatus used in an example of the present invention.
FIG. 11 is an explanatory diagram of a calculation method of the softening point (melting temperature in the 1/2 method) of the binder resin by the flow tester of the present invention.
FIG. 12 is a scanning electron microscope (SEM, magnification) of toner ct1 produced in an example of the present invention.
(5000 magnifications) Observation image.
FIG. 13 is an SEM observation image (magnification 3000 times) of toner CT2 produced in an example of the present invention.
FIG. 14 is an SEM observation image (magnification 3000 times) of toner CT4 produced in an example of the present invention.
FIG. 15 is an SEM observation image (magnification 3000 times) of the toner ct5 produced in the example of the present invention.
FIG. 16 is an SEM observation image (magnification: 3000 times) of toner CT7 produced in an example of the present invention.
FIG. 17 is a SEM observation image (magnification 3000 times) of toner CT8 produced in an example of the present invention.
FIG. 18 is an SEM observation image (magnification 3000 times) of the toner ct11 produced in the example of the present invention.
FIG. 19 is an explanatory diagram for explaining the shape index of the present invention.
BEST MODE FOR CARRYING OUT THE INVENTION
[0025]
In the present invention, at least the first resin particles, the third resin particles for adjusting the shape of the toner, the colorant particles, and the wax particles are aggregated into the core particles formed in the aqueous medium. By fusing the resin particles, it is possible to arbitrarily control the shape of the particles, and at the same time, the toner base particles are made coarse, and the toner base particles having a small particle size and a narrow particle size distribution are created without a classification step. can do.
[0026]
In addition, storage stability can be maintained while improving low-temperature fixability / glossiness and high-temperature non-offset properties.
[0027]
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.
[0028]
Hereinafter, each element of the present invention will be described.
[0029]
(1) Polymerization process
The resin particle dispersion is prepared by emulsion polymerization or seed polymerization of a vinyl monomer in a surfactant to obtain a resin particle of a vinyl monomer homopolymer or copolymer (vinyl resin). A dispersion is prepared in which is dispersed in a surfactant. 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.
[0030]
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 made of resin other than vinyl resin are dispersed in a surfactant is prepared.
[0031]
As polymerization initiators, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2 , 2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile and other azo or diazo polymerization initiators, persulfates (potassium persulfate, ammonium persulfate, etc.), azo compounds (4,4′-azobis-4-cyanovaleric acid and its salt, 2,2′-azobis (2-amidinopropane) salt, etc.), peroxide compounds and the like.
[0032]
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.
[0033]
The wax particle dispersion is prepared by adding wax particles in water to which a surfactant is added and dispersing the particles using the above-described dispersion means.
[0034]
Toners are required to have further low-temperature fixing, high-temperature non-offset property in oilless fixing, releasability, high transparency of color images, and storage stability under a certain high temperature, and must satisfy these simultaneously. I must.
[0035]
The toner of the present invention includes, in an aqueous medium, at least a first resin particle dispersion in which first resin particles are dispersed, and a third resin particle in which third resin particles for adjusting the shape of the toner are dispersed. A resin particle dispersion, a colorant particle dispersion in which colorant particles are dispersed, and a wax particle dispersion in which wax particles are dispersed are mixed and aggregated to produce core particles. Then, a second resin particle dispersion in which the second resin particles are dispersed is added to the core particle dispersion containing the generated core particles, and the second resin particles are fused to the core particles. Toner.
[0036]
The third resin particles are blended with the core particles for the purpose of controlling the shape of the particles. By adding resin particles having a certain relationship with the characteristics of the first resin particles, the shape can be changed by changing the aggregation reactivity of the core particles.
[0037]
As a preferable characteristic of the third resin particle, when the softening point in the melt viscosity characteristic of the third resin particle is Ts3 (° C.) and the softening point in the melt viscosity characteristic of the first resin particle is Ts1 (° C.),
Ts1 + 30 ° C ≦ Ts3 ≦ Ts1 + 80 ° C
Satisfy the relationship. Due to the presence of the third resin particles having a certain softening point, the agglomeration reaction during the heat treatment delays the state in which the agglomerated particles are melted by the presence of the resin particles having different melting states, and the surface due to the melting of the particles By changing the effect of tension, the shape can be changed from a spherical shape to a potato shape or an indeterminate shape. If the difference between the softening points of the third resin particles and the first resin particles is less than 30 ° C., it is difficult to delay the state in which the melting of the core particles proceeds, and the shape adjustment tends not to proceed well. Conversely, if the difference in softening point between the third resin particles and the first resin particles exceeds 80 ° C., the aggregation of the core particles is difficult to proceed, and the third resin particles are difficult to be taken into the core particles. There are cases where the three resin particles remain in the aqueous system and white turbidity in the aqueous system remains.
[0038]
Further, as a preferable second characteristic of the third resin particles, when the weight average molecular weight in the gel permeation chromatogram of the third resin particles is Mwr3 and the weight average molecular weight of the first resin particles is Mwr1, Mwr1 × 1. The relationship of 5 ≦ Mwr3 ≦ Mwr1 × 12 is satisfied. Due to the presence of the third resin particles having a certain weight average molecular weight, in the agglomeration reaction in the course of the heat treatment, the state in which the melting of the core particles proceeds due to the presence of the resin particles having different melting states is delayed. It becomes possible to change from a spherical shape to a potato shape or an indeterminate shape. If the weight average molecular weight of the third resin particles is less than 1.5 times the weight average molecular weight of the first resin particles, it is difficult to delay the state in which the melting of the core particles proceeds, and the shape adjustment does not proceed well. There is a tendency. Conversely, if the weight average molecular weight of the third resin particles exceeds 12 times the weight average molecular weight of the first resin particles, the aggregation of the core particles is difficult to proceed, and the third resin particles are difficult to be taken into the core particles. The third resin particles tend to remain in the aqueous system and remain cloudy in the aqueous system.
[0039]
Moreover, it is preferable that the mixture ratio of the 3rd resin particle shall be 2-30 weight part with respect to 100 weight part of 1st resin particles. If it is less than 2 parts by weight, it is difficult to obtain the effect of shape adjustment. When it exceeds 30 parts by weight, the cohesiveness of the core particles is deteriorated, the third resin particles are not easily taken into the core particles, and the third resin particles tend to remain in the aqueous system and remain cloudy in the aqueous system. .
[0040]
The blending ratio of the third resin particles is also related to the softening point or the weight average molecular weight of the third resin particles. The higher the softening point or the weight average molecular weight, the smaller the blending amount.
[0041]
When Ts3 is Ts1 + 30 ° C. to Ts1 + 45 ° C., the blending ratio of the third resin particles is in the range of 22 to 30 parts by weight with respect to 100 parts by weight of the first resin particles, and when Ts3 is Ts1 + 45 ° C. to Ts1 + 65 ° C. The mixing ratio of the third resin particles is in the range of 12 to 22 parts by weight with respect to 100 parts by weight of the first resin particles. When Ts3 is Ts1 + 65 ° C. to Ts1 + 80 ° C., the mixing ratio of the third resin particles is However, the amount needs to be increased or decreased depending on the target shape with respect to 100 parts by weight of the first resin particles.
[0042]
When Mwr3 is Mwr1 × 1.5 to Mwr1 × 4, the blending ratio of the third resin particles is 22 to 30 parts by weight with respect to 100 parts by weight of the first resin particles, and Mwr3 is Mwr1. In the case of × 4 to Mwr1 × 8, the blending ratio of the third resin particles is in the range of 12 to 22 parts by weight with respect to 100 parts by weight of the first resin particles, and Mwr3 is Mwr1 × 8 to Mwr1 × 12. When the mixing ratio of the third resin particles is in the range of 2 to 12 parts by weight with respect to 100 parts by weight of the first resin particles, the amount needs to be increased or decreased depending on the target shape. There is.
[0043]
In the toner production method of the present invention, at least a first resin particle dispersion in which the first resin particles are dispersed and a third resin particle for adjusting the shape of the toner are dispersed in an aqueous medium. Three resin particle dispersions, a colorant particle dispersion in which colorant particles are dispersed, and a wax particle dispersion in which wax particles are dispersed are mixed, and a core particle dispersion containing core particles produced by aggregation is obtained. The second resin particle dispersion in which the second resin particles are dispersed is added, and the second resin particles are produced by a method of fusing the core particles to the core particles.
[0044]
As a preferable method for generating the core particles, a first resin particle dispersion in which the first resin particles are dispersed, and a third resin particle dispersion in which the third resin particles for adjusting the shape of the toner are dispersed. , Adjust the pH of the mixture dispersion, which is a mixture of the colorant particle dispersion in which the colorant particles are dispersed and the wax particle dispersion in which the wax particles are dispersed, under a certain condition, and add a certain amount of water-soluble inorganic salt. To do. Then, the first resin particle, the third resin particle, the colorant particle, and the wax particle are heated by heating the aqueous medium to the glass transition temperature (Tg) or higher of the first resin particle and / or the melting point of the wax or higher. Can be formed and core particles in which at least a part is melted can be produced.
[0045]
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.
[0046]
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.
[0047]
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.
[0048]
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 the range of 10.5 to 12.2, more preferably the pH is in 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 phenomenon that the formed core particles become coarse. In addition, by setting the pH value to 12.2 or less, there is an effect of suppressing generation of free wax particles and colorant particles and facilitating uniform encapsulation of wax and colorant.
[0049]
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.
[0050]
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.
[0051]
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.
[0052]
A glass-lined stainless steel (SUS) kettle as a preferred reaction kettle used for emulsion polymerization, mixing, and agglomeration is not particularly limited as a stirring blade for stirring the dispersion, but the width in the depth direction is not particularly limited. A wide blade shape (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.
[0053]
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.
[0054]
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.
[0055]
In the toner production method of the present invention, as a preferred embodiment of core particle generation, in an aqueous medium, a first resin particle dispersion, a third resin particle dispersion, a colorant particle dispersion, and a wax particle dispersion Are mixed to form a mixed dispersion. Then, this mixed dispersion is heated, and after the liquid temperature of the mixed dispersion reaches a certain temperature, a water-soluble inorganic salt is added as a flocculant to the mixed dispersion.
[0056]
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 encapsulated.
[0057]
Further, as described later, when waxes having different melting points are used in combination, the low melting point wax is first melted in the process of raising the temperature. Since melting starts and aggregation starts, this is an effective method for preventing the formation of aggregates 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 being widened and the shape distribution from becoming uneven.
[0058]
In the toner production method of the present invention, as a preferred embodiment of core particle generation, the first resin particle dispersion, the third resin particle dispersion, and the colorant particle dispersion are mixed and aggregated in an aqueous medium. The resin particles and the colorant particles are agglomerated to form core particles, and the core particle dispersion is mixed with the first resin particle dispersion liquid and the wax particle dispersion liquid. It is also preferable to produce core particles by aggregating the resin particles and wax particles.
[0059]
In an aqueous medium, a resin particle dispersion in which resin particles are dispersed and a colorant particle dispersion in which colorant particles are dispersed are mixed to form a mixed solution. After heating the mixed liquid and the liquid temperature of the mixed liquid reaches a certain temperature, a water-soluble inorganic salt is added to the mixed dispersion as a flocculant to agglomerate the resin particles and the colorant particles. Is generated. Thereafter, in a heated state, the resin particle dispersion and the wax particle dispersion are added to the core particle dispersion in which the core particles are generated, and the core particles, the resin particles, and the wax are aggregated to generate core particles. . By avoiding direct agglomeration with wax, the function of shape adjustment is more effectively exhibited.
[0060]
By adding the flocculant when the temperature of the mixed solution 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.
[0061]
In addition, the contact between the wax particles and the colorant particles is performed through the resin particles, so that the reaction between the resin particles and the colorant particles and the reaction between the resin particles and the wax particles is given priority. Each of the particles can be easily taken into the core particles uniformly, and core particles having a small particle size and a narrow particle size distribution in which wax and colorant are uniformly encapsulated can be formed.
[0062]
The core particle preferably has a structure in which a core particle portion obtained by aggregating resin particles and colorant particles and a mixed particle of resin particles and wax particles are fused to the surface of the core particles. By not exposing the colorant particles to the surface of the toner particles, the influence on the charging property can be minimized. By bringing the wax particles closer to the toner particle surface layer, the fixing property (non-offset temperature range) can be expanded. As will be described later, it is also preferable to fuse the second resin particles to the surface of the core particles.
[0063]
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 to add the mixture, the third resin particle dispersion, the colorant particle dispersion in which the colorant particles are dispersed, and the wax dispersion in which the wax particles are mixed.
[0064]
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 by adding an aqueous flocculant solution having a pH value with a certain relationship to the mixed dispersion, the core particles become coarse or the wax The phenomenon of non-uniform dispersion can be suppressed, which is effective.
[0065]
The mixed dispersion obtained by mixing the first resin particle dispersion, the third resin particle dispersion, the colorant particle dispersion, and the wax particle dispersion is subjected to heat treatment, and the mixed dispersion before the addition of the aqueous solution containing the flocculant When the pH value is HG, it is preferable that the pH value of the aqueous solution containing the flocculant is adjusted within the range of HG + 2 to HG-4. The range is preferably HG + 2 to HG-3, more preferably the range HG + 1.5 to HG-2, and still more preferably the range HG + 1 to HG-2.
[0066]
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 core particles tend to become 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, it is more preferable that the pH value of the aqueous solution containing the flocculant is lower than the pH value of the mixed dispersion.
[0067]
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 core particle becomes coarse or the particle size distribution becomes broad.
[0068]
The timing of adding the flocculant is the DSC method described later, where the temperature of the mixed dispersion obtained by mixing the first resin particle dispersion, the third resin particle dispersion, the colorant particle dispersion, and the wax particle dispersion is mixed. It is preferable to add the flocculant after reaching the melting point of the wax measured by 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.
[0069]
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.
[0070]
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 temperature is adjusted to a specific temperature of a wax having a higher melting point. It is effective to add the flocculant in a temperature state where the melting of the wax particles is started.
[0071]
The total amount of the flocculant may be added all at once, but it is also preferable that the flocculant is dropped 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.
[0072]
It is preferable to add 1 to 50 parts by weight of the flocculant with respect to 100 parts by weight of the total of the first resin particles, the third resin particles, the pigment fine particles, and the wax fine particles. 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. When the amount is too large, the generated particles tend to be coarse.
[0073]
In addition to the first resin particle dispersion, the third resin particle dispersion, the colorant particle dispersion, and the wax particle dispersion, the mixed dispersion is prepared by adding ion-exchanged water to adjust the solid concentration in the liquid. It doesn't matter. The solid concentration in the liquid is preferably 5 to 40% by weight.
[0074]
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% by weight.
[0075]
In addition, the first resin particle dispersion and the wax particle dispersion are added to the core particle dispersion in which the first resin particles, the core particles obtained by aggregating the third resin particles and the colorant particles are generated, and the core particles are added. In the example in which the first resin particles and the wax are aggregated to produce the core particles, the first resin particle dispersion, the third resin particle dispersion, and the colorant particle dispersion are used as the timing for adding the flocculant. It is also preferable to add the flocculant after the temperature of the mixed dispersion obtained by mixing the dispersion reaches the melting point of the wax measured by the DSC method described later.
[0076]
This is to increase the temperature of the aqueous medium above the melting point of the wax in order to promote the adhesion of the first resin particles and wax particles subsequently dropped after the formation of the core particles to the core particles without changing the temperature of the aqueous medium. When the wax is dripped, melting of the wax is started, aggregation of the melting wax particles, the first resin particles, and the core particles proceeds at a stretch, and the heat treatment is continued to further increase the core particles. The formation of core particles in which the first resin particles and the wax particles are aggregated progresses quickly, and particles having a small particle size and a narrow particle size distribution can be formed.
[0077]
When the core particles are produced by aggregating the first resin particles and the colorant particles, the agglomeration agent is added even when the flocculant is added when the temperature of the mixed dispersion reaches the glass transition point of the first resin particles. Is difficult to progress. When the temperature of the mixed dispersion reaches 80 ° C. or higher, the particles grow and the particles tend to grow to a particle size of 1 to 3 μm.
[0078]
Further, 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 temperature is adjusted to a specific temperature of a wax having a higher melting point.
[0079]
After adding the flocculant to form the first resin particles, the core particles where the third resin particles and the colorant particles are aggregated, the first resin particle dispersion and the wax particle dispersion are dropped, and the core particles And the first resin particles and wax particles are aggregated to produce core particles. It is preferable to continue the temperature of the aqueous medium at this time without changing.
[0080]
The first resin particles used for the core particles and the first resin particles used when the core particles are subsequently added together with the wax particles may be resins having different compositions and thermal characteristics, but they are the same. The first resin particles are preferred.
[0081]
When the total amount of the first resin particles contained in the core particles is 100, the first resin particles used for the core particles are preferably 30 to 80 by weight. By setting it to 30 or more, it is possible to generate a core particle having a small particle size and a narrow particle size distribution by aggregation of the first resin particles and the colorant particles. When it is less than 30, the dispersibility of the colorant particles tends to be lowered.
[0082]
The first resin particles and the wax particle dispersion are preferably dropped separately, or a dispersion previously mixed at a constant rate is preferably dropped at a constant dropping rate. If the total amount is added in a large amount, the temperature of the liquid may decrease, and aggregation may not progress uniformly.
[0083]
After dripping the predetermined amount of the first resin particles and the wax particle dispersion, the heat treatment is continued for a predetermined time. The time is preferably 10 minutes to 2 hours. Preferably, in 10 to 30 minutes, after mixing uniformly to some extent and keeping the temperature stable, the pH of the mixed solution in which the core particles, the first resin particles, and the wax particles are mixed is adjusted to 7 or more and 10 or less. To do. Thereby, adhesion of the 1st resin particle and wax particle to a core particle can be advanced. If the pH of the mixed solution is smaller than 7 or larger than 10, it becomes difficult to cause the first resin particles and wax particles to adhere to the core particles, and the core particles become coarse or the floating particles increase. It will be.
[0084]
After the pH adjustment, the heat treatment is continued for a predetermined time until a predetermined particle size and surface smoothness are obtained, whereby core particles are generated. The shape or surface smoothness of the core particles can be controlled by the heating time.
[0085]
The heating time is 0.5 to 5 hours, preferably 0.5 to 3 hours, more preferably 1 to 2 hours, whereby core particles having a predetermined particle size distribution are produced. 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.
[0086]
In 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. The toner base particles are produced by fusing the particles to the core particles.
[0087]
From the viewpoint of charging stability, it is desirable to form a fusion layer (sometimes referred to as a coating layer or a shell layer) on the core particles of the second resin particles. In addition, since resin particles with different softening points are present in the core particle as a shape adjustment, unevenness may occur on the particle surface, which may affect the chargeability and fluidity, so it is effective to provide a shell layer. It is.
[0088]
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, and 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.
[0089]
When 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 adjusted 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.
[0090]
The pH value of the second resin particle dispersion in which the second resin particles adjusted to the 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.
[0091]
The pH value of the second resin particle dispersion in which the second resin particles are dispersed is higher than the pH value of the core particle dispersion in which the core particles are dispersed, that is, adjusted to be more alkaline and added. Is preferred. 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. .
[0092]
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. Adhesion of particles can be promoted, generation of floating second resin particles not participating in fusion can be suppressed, and generation of secondary aggregation between core particles can be suppressed.
[0093]
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.
[0094]
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 The resin particles tend to remain in a floating state 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.
[0095]
The pH value can be adjusted by adding sodium hydroxide or hydrochloric acid solution.
[0096]
When 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, it is preferable that 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. 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.
[0097]
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.
[0098]
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.
[0099]
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.
[0100]
The conditions under which the second resin particle dispersion is added dropwise are preferred so as to keep the fluctuation of the liquid temperature of the core particle dispersion in which the produced core particles are dispersed within 10%.
[0101]
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 heat-treat 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.
[0102]
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 inhibited.
[0103]
In 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 amount of the polymerization initiator added is 100% monomer. 0.5 to 2.5 parts by weight with respect to parts by weight, 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 styrene monomer, (meth) It is preferable that the compounding quantity of the vinyl compound which has an acrylic acid ester monomer and an acid group-containing vinyl-type monomer and has an acid group shall be 0.1 to 5.0 weight% in a monomer.
[0104]
About the addition amount of a polymerization initiator, it exists in the tendency to influence aggregation of a 1st resin particle, a 3rd resin particle, a colorant particle, and a wax particle by the abundance of the hydrophilic group derived from a polymerization initiator. In other words, when the addition amount of the polymerization initiator is large, the aggregation reaction tends to proceed slowly, and when the addition amount of the polymerization initiator is small, the aggregation reaction tends to proceed earlier. 0.5 to 2.5 parts by weight per 100 parts by weight. 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 addition amount of the polymerization initiator is less than 0.5 parts by weight, the aggregation of the first resin particles proceeds quickly, and the first resin particles are aggregated without forming the core particles aggregated with the wax and the pigment. Coarse particles of the resin are produced. 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 agglomeration reaction proceeds slowly due to the amount of hydrophilic groups derived from the polymerization initiator.
[0105]
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.
[0106]
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 considered that the agglomeration is affected, whereby the dispersion state of the wax is fluctuated, the high temperature non-offset property is deteriorated, and the fixable temperature range is narrowed.
[0107]
In the present invention, the main component of the surfactant used when preparing the colorant particle or wax particle dispersion is preferably a nonionic surfactant. In this specification, a main component means 50 weight% or more.
[0108]
In the present invention, the first resin particle dispersion in which the first resin particles are dispersed, the third resin particle dispersion in which the third resin particles are dispersed, or the second resin particle dispersion in which the second resin particles are dispersed. The main component of the surfactant used for preparing the liquid is a nonionic surfactant, and the main component of the surfactant used for the colorant particle and wax particle dispersion is preferably a nonionic surfactant. .
[0109]
In the present invention, the first resin particle dispersion in which the first resin particles are dispersed, the third resin particle dispersion in which the third resin particles are dispersed, or the second resin particle dispersion in which the second resin particles are dispersed. Of the surfactants used in preparing the liquid, the nonionic surfactant preferably has 50 to 95% by weight based on the total surfactant. More preferably, it is 55 to 90 weight%, More preferably, it is 60 to 85 weight%.
[0110]
Moreover, it is preferable that nonionic surfactant has 50 to 100 weight% with respect to the whole surfactant among surfactant used for a coloring agent particle dispersion and a wax particle dispersion. More preferably, it is 60-100 weight%, More preferably, it is preferable to have 60-90 weight%.
[0111]
Among the surfactants used in the dispersion of each particle, the blending ratio of the ionic surfactant (preferably anionic surfactant) to the whole surfactant is such that wax particles, colorant particles, first resin particles, It is preferable to increase the order of the three resin particles.
[0112]
First, the first resin particles that use anionic surfactant in a large proportion start agglomeration to form nuclei, and then color that uses anionic surfactant in a larger proportion than wax particles The agent particles begin to aggregate around the core of the resin particles. Finally, it is presumed that the wax particles using the most nonionic surfactant are aggregated and aggregated so as to wrap the colorant particles together with the resin particles to form core particles. First, the first resin particles start to aggregate to form nuclei, but the colorant particles and wax particles are not taken into the core particles, and the colorant particles and wax particles that do not participate in aggregation remain in the core particle dispersion. This is considered to be a point to avoid the phenomenon.
[0113]
In the present invention, the surfactant used when preparing the first resin particle dispersion in which the first resin particles are dispersed and the third resin particle dispersion in which the third resin particles are dispersed is a nonionic surfactant. It is also preferable that the main component of the surfactant used in the wax particle dispersion and the colorant particle dispersion is only a nonionic surfactant.
[0114]
When such a resin particle, colorant particle, and wax particle are used and an aggregating agent is allowed to act in an aqueous medium, the resin particle starts to aggregate to form a nucleus. Next, the colorant particles begin to aggregate around the cores of the resin particles. Finally, the wax particles are aggregated, and the colorant particles are encapsulated with the resin particles. Resin particles are usually added several times or more in weight concentration as compared with colorant particles and wax particles, so that the core of the resin particles only aggregates on the wax particles and the outermost surface is covered with resin. Is estimated to be formed. It is considered that by this mechanism, the presence of floating colorant particles and wax particles that are not involved in aggregation in an aqueous system is eliminated, and core particles having a small particle size, a uniform and sharp particle size distribution can be formed. .
[0115]
In a mixed system of a nonionic surfactant and an ionic surfactant, and in the surfactant of the first resin particle dispersion and the third resin particle dispersion, the nonionic surfactant is added to the entire surfactant. On the other hand, it is preferably 50 to 95% by weight. More preferably, it is 55-90 weight%, More preferably, it is 60-85 weight%. By setting it to 50% by weight or more, it becomes easy to suppress the phenomenon that the particle size distribution of the generated core particles is widened. By making it 95% by weight or less, the dispersion of the resin particles themselves in the resin particle dispersion is easily stabilized. As the ionic surfactant, an anionic surfactant is preferable.
[0116]
Furthermore, in the colorant particles and wax particle dispersions dispersed only with the nonionic surfactant, the average ethylene oxide addition mole number of the nonionic surfactant used for wax particle dispersion is used for the colorant particle dispersion. It is preferable that it is larger than the average number of moles of added ethylene oxide of the nonionic surfactant. This is because the nonionic surfactant having a smaller average number of moles of added ethylene oxide tends to have higher cohesiveness with respect to the coagulant.
[0117]
The average number of moles of ethylene oxide added to the nonionic surfactant used for dispersing the pigment particles is preferably 18 to 33. More preferably, it is 20-30, More preferably, it is 20-26.
[0118]
If the average ethylene oxide addition mole number of the nonionic surfactant is smaller than 18, the cohesiveness of the pigment particles with respect to the coagulant becomes too high, and grows into large particles before being surrounded by the resin, and is incorporated into the toner particles. It will not be. On the other hand, when the average ethylene oxide addition mole number of the nonionic surfactant is larger than 33, the cohesiveness with respect to the flocculant becomes too low, and the carbon black fine particles do not aggregate and exist as fine particles in the reaction solution. As a result, the toner particles are not taken into the toner particles.
[0119]
It is also preferred that the nonionic surfactant used for dispersing the pigment particles contains a plurality of nonionic surfactants. By itself, even if the average ethylene oxide addition mole number of the nonionic surfactant is not in the range of 20 to 30, the weight average ethylene oxide addition mole number of the plurality of nonionic surfactants may be in the range of 20 to 30. That's fine.
[0120]
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 dropped into an aggregating agent aqueous solution of various concentrations (for example, magnesium sulfate aqueous solution) and the particles are aggregated 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.
[0121]
When such a resin particle, a colorant particle, and a wax particle are used and a flocculant is allowed to act in a solution, first, the resin particle using the anionic surfactant starts agglomeration to form a nucleus. Next, the colorant particles using the nonionic surfactant having a small average number of moles of added ethylene oxide begin to aggregate around the cores of the resin particles. Finally, wax particles using a nonionic surfactant having a large average number of moles of added ethylene oxide are aggregated and aggregated so as to wrap the colorant particles together with the resin particles to form core particles.
[0122]
It is possible to avoid a phenomenon in which the colorant particles and wax particles are not taken into the core particles and the colorant particles and wax particles that do not participate in aggregation in the core particle dispersion liquid remain.
[0123]
The amount of the nonionic surfactant relative to the pigment particles is preferably 10 to 20 parts by weight with respect to 100 parts by weight of carbon black in terms of dispersion stability.
[0124]
The main component of the surfactant used in the second resin dispersion is preferably a nonionic surfactant. Furthermore, it is also preferable that the surfactant used in the second resin particle dispersion is a mixture of a nonionic surfactant and an ionic surfactant. The nonionic surfactant is preferably 50 to 95% by weight based on the whole surfactant. More preferably, it is 55-90 weight%, More preferably, it is 60-85 weight%. By setting it to 50% by weight or more, adhesion of the second resin particle fine particles to the core particles can be promoted. By setting it to 95% by weight or less, there is an effect of stabilizing the dispersion of the resin particles themselves in the resin particle dispersion.
[0125]
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.
[0126]
As the polymerization initiator, persulfates such as potassium persulfate, ammonium persulfate, sodium persulfate and the like are preferable materials.
[0127]
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 it to a certain concentration with ion exchange water or the like.
[0128]
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.
[0129]
Polyethylene glycol type nonionic surfactants such as higher alcohol ethylene oxide adducts and alkylphenol ethylene oxide adducts can be particularly preferably used.
[0130]
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.
[0131]
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.
[0132]
Specific examples of the anionic surfactant include sodium dodecylbenzenesulfonate, sodium dodecylsulfate, sodium alkylnaphthalenesulfonate, sodium dialkylsulfosuccinate and the like.
[0133]
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.
[0134]
(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.
[0135]
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.
[0136]
The softening point (Ts1) of the first resin particles constituting the core particles is preferably in the range of 80 ° C to 130 ° C. 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 less than 80 ° C., the agglomeration proceeds rapidly and it tends to be difficult to form particles having 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 exceeds 130 ° C., the low-temperature fixability tends to deteriorate.
[0137]
Moreover, it is preferable that the glass transition point of the 1st resin particle which comprises a core particle is 45 to 60 degreeC. 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 less than 45 ° C., the core particles are coarsened, and the storage stability and heat resistance tend to decrease. If it exceeds 60 ° C., the low-temperature fixability tends to deteriorate.
[0138]
The first resin particles have a weight average molecular weight (Mwr1) of 10,000 to 60,000 and a ratio Mwr1 / Mnr1 of the weight average molecular weight (Mwr1) to the number average molecular weight (Mnr1) of 1.5 to 6. preferable. More preferably, 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 preferably 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 exceeds 6, the shape of the core particle is not stable, tends to be indefinite, and unevenness remains on the particle surface, which tends to be inferior in surface smoothness.
[0139]
As described above, the first resin particles want to lower the softening point or the molecular weight as much as possible in order to improve the low-temperature fixability. It tends to be difficult. 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.
[0140]
Moreover, as a 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 50,000-. It is preferable that the ratio Mw / Mn of 500,000 and the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 2 to 10. More preferably, the glass transition point is 60 ° C to 70 ° C, the softening point is 145 ° C to 180 ° C, Mw is 80,000 to 500,000, and 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. Durability, high-temperature offset resistance, and separability can be improved by promoting thermal fusion of the core particle surfaces and setting the softening point higher.
[0141]
In addition, when the second resin particles constituting the shell are fused to the core particles blended with the third resin particles, there are different portions such as softening points in the core particles. In order to prevent non-uniformity, it is effective to have the above-mentioned constant glass transition point, softening point, or molecular weight characteristics. Further, even when the different shape becomes a potato shape or an indeterminate shape, it is effective to use the second resin particles having the above-mentioned characteristics in order to prevent the second resin particles from being unevenly adhered. is there.
[0142]
When the glass transition point of the second resin particles is less than 55 ° C., secondary aggregation in which aggregation of core particles proceeds tends to occur. In addition, the storage stability tends to deteriorate. When it exceeds 75 ° C., the heat fusion property to the surface of the core particle is deteriorated, and the uniform adhesion tends to be lowered.
[0143]
When the softening point of the second resin particles is less than 140 ° C., durability, high-temperature offset resistance, and separation between paper and the fixing roller tend to decrease. When it exceeds 180 ° C., the gloss and translucency tend to decrease.
[0144]
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.
[0145]
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 super HM-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.
[0146]
The softening point of the binder resin (first resin) particles is in the range of 80 to 130 ° C., and the softening points of the shape-adjusting resin particles (third resin) and the coating resin (second resin) particles are 140 to 180 respectively. It is preferably in the range of ° C. The same resin can be used for the shape-adjusting resin particles (third resin) and the coating resin (second resin) particles.
[0147]
The softening point of the binder resin is measured by a constant-load extrusion type capillary rheometer flow tester (CFT500) manufactured by Shimadzu Corporation.
[0148]
First, a sample is filled in a cylinder, heated from the surroundings and melted, and a certain pressure is applied from above by a piston. The molten sample was extruded through a die with a narrow hole (diameter 1 mm, length 1 mm) and flow rate (cm ^Three / G), the fluidity of the sample, that is, the melt viscosity is obtained.
[0149]
A heating furnace surrounding the cylinder and die is provided and set to 50 ° C. Fill the cylinder with 1 g of sample. Hold at 50 ° C. for 2.5 min without applying load. A load is applied to remove air from the sample. At this time, the length of the piston coming out of the heating furnace is set to about 12 to 15 mm. When the total holding time reaches 5 minutes, the temperature rise is started.
[0150]
9.8x10 on the piston ^Five N / m ² And heating at a rate of temperature increase of 6 ° C./min. When the sample starts to melt, the downward movement of the piston begins. When the movement of the piston stops, the temperature rise and pressurization are stopped.
[0151]
At this time, the viscosity at each temperature can be measured from the relationship with the temperature rise temperature characteristic in the relationship between the moving amount of the descending piston and the temperature.
[0152]
FIG. 11 shows a flow curve. The horizontal axis shows the temperature, and the vertical axis shows the image of the piston movement. At the time of A, it is a solid state region of the sample, and as temperature rises thereafter, A to B are transition regions, where the sample is deformed by receiving a compressive load and the internal voids gradually decrease. B is a temperature at which the internal voids disappear and a single transparent body having a uniform appearance with a non-uniform stress distribution is obtained.
[0153]
B to C are regions where there is no clear change in the piston position within a finite time, and it is difficult for the sample to flow out of the die, and this region includes the rubbery elastic region of the sample.
[0154]
C is defined as a temperature at which the sample starts to flow (outflow start temperature (Tfb)) at a temperature at which the sample starts to flow and the piston starts to descend.
[0155]
The region from C to D through E is the flow region where the sample clearly flows out of the die, where E is the point where the sample has finished flowing out.
[0156]
The softening point of the binder resin is defined by the melting temperature in the 1/2 method (softening point Ts ° C.). Specifically, the softening point is defined as the temperature at which the piston moves 50% from the outflow start temperature with respect to the total movement distance of the piston from the outflow start temperature to the outflow end temperature.
[0157]
11, the temperature at which the piston starts to descend (temperature at which the sample flows) is first measured. This is the outflow start temperature (Tfb). The piston position at this time is read and made the minimum value (Smin).
[0158]
Thereafter, as the temperature rises, the sample continues to flow out of the die, and the temperature at the outflow end point E at which the outflow of the sample is completed and the position of the piston are read and set as the outflow end point (Smax).
[0159]
1/2 of the difference between the outflow end point (Smax) and the minimum value (Smin) is obtained (X = (Smax−Smin) / 2), and the temperature at the position of the point D where X and the minimum value Smin of the curve are added is calculated. calculate. This is the melting temperature (softening point Ts ° C.) in the 1/2 method.
[0160]
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. The temperature at the intersection with the indicated tangent.
[0161]
In order to measure the thermal characteristics 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 of extracting the solid content of the resin particles from this emulsion, it is carried out in the order along the toner aggregation step. First, 2 ml of 1N NaOH is added to 20 g of the emulsion, 6 g of magnesium sulfate and 20 g of ion exchange 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.
[0162]
(3) Wax
Improved low-temperature fixability, high-temperature non-offset properties, improved separation properties of transfer media such as copy paper on which toner melted during fixing and heating rollers, etc., and fixing properties that conflict with storage stability, and improved functionality Therefore, it is preferable to add a plurality of waxes.
[0163]
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.
[0164]
In the present invention, as a preferred first example of the wax, the wax contains at least the first wax and the second wax, and the endothermic peak temperature (referred to as the melting point Tsw1 (° C.)) of the first wax by the DSC method is 50. The endothermic peak temperature (melting point Tsw2 (° C.)) of the second wax by DSC method is set to 80 to 120 ° C. Storage stability will deteriorate that Tsw1 is less than 50 degreeC. If it exceeds 90 ° C, the low-temperature fixability and color glossiness will not be improved. Tsw1 is preferably 55 to 85 ° C, more preferably 60 to 85 ° C, and still more preferably 65 to 75 ° C. When Tsw2 is less than 80 ° C., the high temperature non-offset property and the paper separation property tend to be weakened. When the temperature exceeds 120 ° C., the cohesiveness of the wax decreases, and free particles that do not aggregate in the aqueous system tend to increase. Tsw2 is more preferably 85 to 100 ° C, and still more preferably 90 to 100 ° C.
[0165]
As a preferred second example of the wax, the wax contains at least a first wax and a second wax, and the first wax is at least a higher alcohol having 16 to 24 carbon atoms and a higher fatty acid having 16 to 24 carbon atoms. It is preferable that the ester wax comprises one and the second wax contains an aliphatic hydrocarbon wax.
[0166]
As a preferred third example of the 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, The wax preferably contains an aliphatic hydrocarbon wax.
[0167]
In preferred second and third examples of the wax, the endothermic peak temperature (melting point Tsw1 (° C.)) of the first wax by DSC method is 50 to 90 ° C., preferably 55 to 85 ° C., more preferably 60-85 degreeC, More preferably, it is 65-75 degreeC. When it is less than 50 ° C., the storage stability and heat resistance of the toner tend to deteriorate. When it exceeds 90 ° C., the cohesiveness of the wax decreases, and free particles that do not aggregate in the aqueous system increase. In addition, the low-temperature fixability and glossiness tend not to improve.
[0168]
Further, in the second and third examples preferable as the wax, the endothermic peak temperature (melting point Tsw2 (° C.)) of the second wax by DSC method is 80 to 120 ° C., preferably 85 to 100 ° C. Preferably it is 90-100 degreeC. When the temperature is less than 80 ° C., the storage stability tends to deteriorate, and the high temperature non-offset property and the paper separation property tend to be weak. When the temperature exceeds 120 ° C., the cohesiveness of the wax decreases, and free particles that do not aggregate in the aqueous system tend to increase. In addition, low-temperature fixability and color translucency tend to be hindered.
[0169]
In the preferred second or third example of the wax, when forming the core particles together with the resin particles, the colorant and the aliphatic hydrocarbon wax in the aqueous system, the aliphatic hydrocarbon wax is a resin because of its compatibility with the resin. Agglomeration tends to occur, and the presence of particles floating without wax being incorporated into the core particles or the aggregation of the core particles does not proceed and the particle size distribution tends to be broad.
[0170]
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. Further, when the shell is formed, a phenomenon that the core particles are coarsened tends to occur.
[0171]
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. .
[0172]
During the heat aggregation, the first wax is compatibilized with the resin, so that the aggregation of the aliphatic hydrocarbon wax with the resin is promoted and uniformly taken in, and the generation of suspended particles can be prevented. Furthermore, the first wax tends to be improved in low-temperature fixability due to partial progress of compatibilization with the resin. In addition, since the aliphatic hydrocarbon wax is less likely to be compatibilized with the resin, this wax can exert 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.
[0173]
In the preferred second or third example of the wax, as described in the preferred first example, when the toner particles are formed by aggregating a wax having a different melting point with a resin and a colorant in an aqueous system, In order to further promote the formation of particles having a small particle size and a narrow particle size distribution, and the formation of a shell that melts and attaches the second resin to the core particles, the first wax is used in the production of the wax particle dispersion. The second wax is preferably prepared by mixing, emulsifying and dispersing the first wax and the second wax, not separately. That is, the first wax and the second wax are heated and emulsified and dispersed in a constant blending ratio in the emulsifying and dispersing apparatus. 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.
[0174]
In the preferred first, second or third example of the wax, if the first wax weight ratio with respect to 100 parts by weight of the wax in the wax particle dispersion is ES1, and the second wax weight ratio is FT2, FT2 The relationship of / 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. When it exceeds 10, that is, when the weight ratio of the second wax is too large, low-temperature fixing cannot be realized, and the above-described 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.
[0175]
In the preferred first, second or third examples of 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. As a result, the core particles become coarse and it is difficult to obtain particles having a sharp particle size distribution.
[0176]
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.
[0177]
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 preparation of core particles of these waxes with a resin and a colorant dispersion, wax is not liberated and particles having a small particle size and a narrow particle size distribution can be formed.
[0178]
In the preferred first, second or third example of 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 tend not to be exhibited. When the amount is more than 30 parts by weight, it tends to be difficult to control particles having a small particle diameter.
[0179]
In the preferred first, second or third example of the wax, Tsw2 is 5 ° C. or more higher than Tsw1 and preferably 50 ° C. or less. More preferably, the temperature is 10 ° C or higher, 40 ° C or lower, more preferably 15 ° C or higher, and preferably 35 ° C or lower. The function of the wax can be efficiently separated, and there is an effect of satisfying both low temperature fixing property, high temperature non-offset property and paper separation property. When the temperature is lower than 5 ° C., the effects of achieving both low-temperature fixability, high-temperature non-offset property, and poor paper separation tend to be difficult to achieve. When the temperature is higher than 50 ° C., the first wax and the second wax are likely to be phase-separated and tend not to be uniformly taken into the toner particles.
[0180]
A preferred first wax includes 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 coarse particle size, and makes it possible to produce toner base particles including core particles having a small particle size and a narrow particle size distribution.
[0181]
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.
[0182]
Specifically, (1) 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, (2 ) 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, (3) montanic acid monoethylene glycol ester, ethylene glycol Distearate, monostearic glyceride, monobehenic acid glyceride, tripalmitic acid glyceride, pentaerythritol monobehenate, pentaerythritol dilinoleate, pentaerythritol trioleate or pentaerythritol tetrastearate Esters composed of higher fatty acids having 16 to 24 carbon atoms such as carbonate and polyhydric alcohols, or (4) diethylene glycol monobehenate, diethylene glycol dibehenate, dipropylene glycol monostearate, distearic acid diglyceride, tetrastearin Preferable examples include esters composed of a higher fatty acid having 16 to 24 carbon atoms such as acid triglyceride, hexabehenic acid tetraglyceride or decastearic acid decaglyceride and a polyhydric alcohol multimer. These waxes may be used alone or in combination of two or more.
[0183]
If the alcohol component and / or the acid component has less than 16 carbon atoms, the function as a dispersion aid is difficult to exhibit, and if it exceeds 24, the function as a low-temperature fixing aid tends to be difficult to exhibit.
[0184]
A preferred first wax 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. When the iodine value exceeds 25, the dispersion stability becomes 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. It tends to be distributed. When the saponification value is less than 30, the presence of unsaponifiable matter and hydrocarbons increases, and formation of uniform core particles having a small particle size tends to be difficult. If the saponification value exceeds 300, suspended matter in the aqueous system tends to increase.
[0185]
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. If the loss on heating is more than 8% by weight, the glass transition point of the toner is lowered and the storage stability of the toner tends to be impaired. The particle size distribution of the generated toner tends to be broad.
[0186]
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, molecular weight 5 × 10 ² ~ 1x10 ^Four It is preferable to have at least one molecular weight maximum peak in this region. 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.
[0187]
Number average molecular weight is less than 100, weight average molecular weight is less than 200, and molecular weight maximum peak is 5 × 10 ² If it is located in a smaller range, the particle size distribution of the generated particles tends to be broad. Storage stability tends to deteriorate.
[0188]
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 (Average molecular weight / number average molecular weight) is greater than 10, and the molecular weight maximum peak is 1 × 10 ^Four If it is located in a range larger than the above region, the releasing action is weakened, the low-temperature fixability is lowered, and the particle size of the produced particles at the time of producing the wax emulsified dispersed particles tends to be difficult to be reduced.
[0189]
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.
[0190]
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 emulsified 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.
[0191]
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, a metal salt 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.
[0192]
Meadowfoam oil fatty acid esters include, for example, esters such as methyl, ethyl, butyl, glycerin, pentaerythritol, polypropylene glycol, or trimethylolpropane. Ester or meadow foam oil fatty acid trimethylolpropane ester is preferred. Effective for low-temperature fixability.
[0193]
Hydrogenated Meadowfoam oil is obtained by hydrogenating Meadowfoam oil to make unsaturated bonds saturated bonds. Low temperature fixability and glossiness can be improved.
[0194]
Furthermore, an esterification reaction product of a meadow foam fatty acid and a polyhydric alcohol such as glycerin, pentaerythritol, trimethylolpropane, etc. 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.
[0195]
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 emulsified 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.
[0196]
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.
[0197]
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.
[0198]
Hydrogenated jojoba oil is obtained by hydrogenating jojoba oil to make unsaturated bonds saturated bonds. Low temperature fixability and glossiness can be improved.
[0199]
Furthermore, an esterification reaction product of jojoba oil fatty acid and a polyhydric alcohol 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.
[0200]
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.
[0201]
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 chloride glacial acetic acid solution to chloroform or carbon tetrachloride solution of sample and titrate the remaining iodine without reaction with sodium thiosulfate standard solution to absorb iodine Calculate the amount.
[0202]
For the measurement of weight loss by heating, the weight of the sample cell is precisely weighed to 0.1 mg (W1 mg), 10 to 15 mg of the sample is put in this, and it is precisely 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 Co., Ltd., the heating rate is 10 ° C./min, the maximum temperature is 220 ° C., the holding time is 1 min, and the heating loss (weight%) = W3 / (W2−W1) × 100. It is done.
[0203]
Measurement of endothermic peak temperature (melting point Tsw ° C), onset temperature and endothermic amount by DSC method (differential scanning calorimeter measurement method) of wax, manufactured by TA Instruments, Q100 type (a genuine electric refrigerator is used for cooling) ), The measurement mode is “standard”, the purge gas (N2) 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 sample to be measured was placed in an aluminum pan as a sample amount of 10 mg ± 2 mg, and 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.
[0204]
In the graph, the horizontal axis shows the temperature of an empty aluminum crimp pan, the vertical axis shows the heat flow, the temperature at which the endothermic curve starts to rise from the baseline is the onset temperature, and the endothermic curve peak value is the endothermic peak temperature. (Melting point).
[0205]
In general, when measuring by the DSC method, in order to erase the thermal history of the sample, once the temperature is raised and cooled, the temperature is raised again and the endotherm at that time is measured. Since the structure was predicted to change, the heating process and cooling process for eliminating the thermal history were omitted.
[0206]
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 can be prevented, and toner base particles having a small particle size and a narrow particle size distribution can be generated.
[0207]
Oilless fixing having low temperature fixing, high glossiness, and translucency can be realized. In addition, the life of the developer can be extended along with the oilless fixing.
[0208]
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.
[0209]
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.
[0210]
As the glycol fatty acid ester, propylene glycol fatty acid esters such as propylene glycol monopalmitate and propylene glycol monostearate, and ethylene glycol fatty acid esters such as ethylene glycol monostearate and ethylene glycol monopalmitate are suitable materials. Low temperature fixability, good slippage during development, and has the effect of preventing carrier spent.
[0211]
As sorbitan fatty acid esters, sorbitan monopalmitate, sorbitan monostearate, sorbitan tripalmitate, and 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.
[0212]
As the second wax, fatty acid hydrocarbon waxes such as polypropylene wax, polyethylene wax, polypropylene polyethylene copolymer wax, microcrystalline wax, paraffin wax, and Fischer-to-push wax can be suitably used.
[0213]
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.
[0214]
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.
[0215]
Preferably, the 16% diameter (PR16) is 20 to 100 nm, the 50% diameter (PR50) is 40 to 160 nm, the 84% diameter (PR84) is 260 nm or less, and 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.
[0216]
More preferably, the 16% diameter (PR16) is 20 to 60 nm, the 50% diameter (PR50) is 40 to 120 nm, the 84% diameter (PR84) is 220 nm or less, and 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.
[0217]
When the resin particle dispersion, the colorant particle dispersion, and the wax particle dispersion are mixed and aggregated to form aggregated particles, the 50% diameter (PR50) is 40 to 300 nm, and the wax is 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.
[0218]
Furthermore, when the aggregated particles are heated in an aqueous system to obtain molten aggregated particles, 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.
[0219]
Particles with PR16 greater than 200 nm, 50% diameter (PR50) greater than 300 nm, PR84 greater than 400 nm, PR84 / PR16 greater than 2.0, less than 200 nm particles less than 65% by volume and greater than 500 nm When the amount exceeds 10% by volume, the wax is difficult to be taken in between the resin particles, and the agglomeration of only the waxes tends to occur frequently. In addition, particles that are not taken into the resin particles and float in water tend to increase. When the agglomerated particles are heated in an aqueous system to obtain fused agglomerated particles, the molten resin particles are less likely to include the melted wax particles, and the wax is less likely to be included in the resin. In addition, when the resin is adhered and fused, the amount of wax that is exposed and released on the surface of the toner base increases, filming on the photoconductor, increased spent on the carrier, handling characteristics during development, and development memory are generated. It tends to be easier.
[0220]
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.
[0221]
Rotation of a wax melt obtained by melting the wax at a wax concentration of 40% by weight or less in a medium added with a dispersant maintained at a temperature equal to or higher than the melting point of the wax, rotating at a high speed through a fixed gap with a fixed body The wax particles can be finely dispersed by emulsifying and dispersing by the action of high shear force generated by the body.
[0222]
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 dispersion can be formed by a treatment time of about 30 seconds to 5 minutes.
[0223]
A rotating body that rotates at a speed of 30 m / s or more, preferably 40 m / s or more, more preferably 50 m / s or more, with a gap of about 1 to 100 μm provided to a fixed stationary body as shown in FIGS. By adding a strong shearing force action, a fine dispersion can be created.
[0224]
The particle size distribution of fine particles can be made narrower and sharper than a disperser such as a homogenizer. Further, even when left for a long time, the fine particles forming the dispersion do not reaggregate and can maintain a stable dispersion state, and the standing stability of the particle size distribution is improved.
[0225]
When the melting point of the wax is high, a molten liquid is prepared by heating in a high pressure state. Also, the wax is dissolved in an oily solvent. This solution is obtained by dispersing fine particles in water together with a surfactant using the disperser shown in FIGS. 3, 4, 5, and 6, and then heating or reducing the pressure to evaporate the oily solvent.
[0226]
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.
[0227]
(4) Pigment
Examples of the colorant (pigment) used in the present embodiment include C.I. I. Blue dyes and pigments of phthalocyanine and its derivatives such as Pigment Blue 15: 3 can be preferably used. Phthalocyanine pigments such as SANDYESUPERBLUE 1809 manufactured by the company can be preferably used.
[0228]
The yellow pigment is C.I. I. Acetoacetic acid arylamide monoazo yellow pigments such as C.I. Pigment Yellow 1, 3, 74, 97 or 98; I. Acetoacetic acid arylamide disazo yellow pigments such as C.I. Pigment Yellow 12, 13, 14, and 17; I. Solven Yellow 19, 77, 79 or C.I. I. Disperse Yellow 164 is blended, and C.I. I. Benzimidazolone pigments of CI Pigment Yellow 93, 180 and 185 are preferred.
[0229]
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.
[0230]
Carbon black can be suitably used as the black pigment. For example, # 52, # 50, # 47, # 45, # 45L, # 44, # 40, # 33, # 32, # 25, # 260, MA100S, # 40 manufactured by Mitsubishi Chemical Corporation, MOGULL manufactured by Cabot Corporation REGAL660R, REGAL500R, REGAL400R, REGAL330R, REGAL300R, REGAL250R, etc. can be preferably used.
[0231]
More preferably, carbon black having a DBP oil absorption (ml / 100 g) of 45 to 70 is preferred. Preferably it is 45-63, More preferably, it is 45-60, More preferably, it is 45-53.
[0232]
By using carbon black particles having a predetermined DBP oil absorption amount, the phenomenon of carbon black particles growing first can be suppressed, and even if the core particles are reduced in size, the carbon black particles are taken into the core particles. In addition, an effect of eliminating carbon black particles remaining without adding to the aggregation of core particles or core particles can be obtained. Although the reason is not clearly understood, it is presumed that carbon black larger than 70 is likely to cause aggregation of carbon black quickly, and the carbon black particles are not easily taken into the core particles or core particles.
[0233]
The particle size of carbon black is preferably 20 to 40 nm. The preferred particle size is 20 to 35 nm. The particle diameter is an arithmetic average diameter measured by an electron microscope. When the particle size is large, the coloring power tends to decrease. When the particle size is small, dispersion in the liquid tends to be difficult.
[0234]
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.
[0235]
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 ^Three ) 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.
[0236]
The median diameter of each particle is usually 1 μm or less, preferably 0.01 to 1 μm. When the median diameter exceeds 1 μm, the particle size distribution of the finally obtained toner for developing an electrostatic charge image is broadened, or free particles are generated, which easily deteriorates performance and reliability. On the other hand, when the median diameter is within the above range, there are no disadvantages, and the uneven distribution among the toners is reduced, the dispersion in the toner is improved, and the variation in performance and reliability is advantageous. The median diameter can be measured using, for example, a Horiba laser diffraction particle size measuring instrument (LA920).
[0237]
(5) External additives
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.
[0238]
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.
[0239]
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.
[0240]
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.
[0241]
It is also preferable to treat the silicone oil-based material after the silane coupling treatment.
[0242]
The external additive having positive electrode chargeability is treated with aminosilane, amino-modified silicone oil or epoxy-modified silicone oil.
[0243]
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.
[0244]
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 and the like). Surface-treated silica or titanium oxide fine powder is more preferable.
[0245]
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 or linoleic acid Is mentioned. Of these, fatty acids having 12 to 22 carbon atoms are preferred.
[0246]
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 is aluminum distearate (Al (OH) (C ₁₇ H ₃₅ COO) ₂ ) Or aluminum monostearate (Al (OH) ₂ (C ₁₇ H ₃₅ COO)), and the like are preferably difatty acid aluminum and monofatty acid aluminum. 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.
[0247]
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.
[0248]
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.
[0249]
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.
[0250]
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. Moreover, the said effect is show | played also by processing a fatty acid etc. with a coupling agent and / or silicone oil.
[0251]
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.
[0252]
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.
[0253]
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.
[0254]
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.
[0255]
It is preferable that 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. 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.
[0256]
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. It is also preferable to externally add at least 0.5 to 3.5 parts by weight. 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.
[0257]
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.
[0258]
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.
[0259]
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.
[0260]
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 It is also preferable to externally add 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. 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.
[0261]
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 externally add.
[0262]
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, 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.
[0263]
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.
[0264]
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 standing to cool 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) / Sample amount (g)] × 100
For ignition loss, about 1 g of a sample is placed in a magnetic crucible that has been dried, allowed to cool, and precisely weighed in advance, and weighed accurately. Ignite for 2 hours in an electric furnace set to 500 ° C. After standing to cool in a desiccator for 1 hour, its weight is precisely weighed and calculated from the following formula.
Loss on ignition (% 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.
[0265]
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 (%)
[0266]
(6) Toner powder physical properties
In this embodiment, the toner base particles including the binder resin, the colorant, and the wax have a volume average particle diameter of 3 to 6 μm, a volume-based variation coefficient of 10 to 25%, and a number-based distribution of 2.0 to 3.63 μm. Of toner particles having a particle size of 10 to 85% by number, toner particles having a particle size of 3.5 to 4.53 μm in a volume-based distribution are 25 to 75% by volume, and 6.06 μm in a volume-based distribution. 2. Toner particles having the above particle diameters are contained at 5% by volume or less, and the volume% of toner particles having a particle diameter of 3.5 to 4.53 μm in the volume-based distribution is V34. When the number% of toner particles having a particle diameter of 5 to 4.53 μm is P34, P34 / V34 is preferably in the range of 0.4 to 2.2.
[0267]
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 in the range of 0.5 to 1.5.
[0268]
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, and toner particles having a particle size of 6.06 μm or more in the volume-based distribution are 0 .5% by volume or less, and P34 / V34 is in the range of 0.5 to 0.9.
[0269]
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.
[0270]
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.
[0271]
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.
[0272]
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.
[0273]
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.
[0274]
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.
[0275]
The purpose of defining P34 / V34 can be used as an index for making toner particles small and narrowing the particle size distribution.
[0276]
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.
[0277]
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.
[0278]
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 craving property by the rubber blade that progresses in the spherical shape is lowered, and when the irregular shape advances, the transfer property tends to be lowered.
[0279]
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.
[0280]
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.
[0281]
The particle size distribution is measured using a Coulter Counter TA-II type (Coulter Counter Co., Ltd.) by 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 by 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.
[0282]
The shape index was determined by the following equation using a real surface view microscope (VE7800) manufactured by Keyence Corporation, measuring the maximum length and projected area of 100 toner base particles magnified 1000 times (d: toner particles) , A: projected area of toner particles, π is the circumference).
SC (shape index) = π · d ² / (4 ・ A)
The shape index will be described with reference to FIG. B in FIG. 19 is a perfect circle whose diameter is the maximum length d of the toner particles, and the area of the perfect circle B is π · (d / 2). ² It is. A in FIG. 19 is a projected area of toner particles. Since the shape index is represented by B / A, B / A = π · (d / 2) ² / A, which is π · d ² / (4 · A).
[0283]
(7) Oilless color fixing
In the present embodiment, it is suitably used for an electrophotographic apparatus having a fixing process of an oil-less fixing configuration in which oil is not used as a means for fixing toner. As the heating means, electromagnetic induction heating is preferable 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 use, 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 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.
[0284]
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.
[0285]
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.
[0286]
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.
[0287]
(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 photoconductor, a charging unit, and a toner carrier, and an electrostatic latent image formed on the image carrier is visualized. A primary transfer process in which an endless transfer member is brought into contact with the image carrier and transferred to the transfer member is sequentially executed to form a multilayer transfer toner image on the transfer member. Then, in the transfer process configured to execute a secondary transfer process in which the multilayer toner images formed on the transfer body are collectively transferred to a transfer medium such as paper or OHP, the first primary transfer is performed. In this structure, the distance from the position to the second primary transfer position is d1 (mm) and the peripheral speed of the photosensitive member is v (mm / s), and the transfer position is d1 / v ≦ 0.65. Both miniaturization and printing speed It is. In order to realize a reduction in size that can process more than 20 sheets per minute (A4) and the machine can be used for SOHO applications, it is essential to shorten the interval between multiple toner image forming stations and increase the process speed. is there. In order to achieve both a reduction in size and a printing speed, the minimum value is considered to be 0.65 or less.
[0288]
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.
[0289]
Therefore, by using the toner of the present exemplary 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】
[0290]
Hereinafter, the present invention will be described more specifically with reference to examples. In addition, this invention is not limited to the following Example.
[0291]
(1) Carrier production example
(A) Creation of carrier CA1
39.7 mol% in terms of MnO, 9.9 mol% in terms of MgO, Fe ₂ O _Three The mixture was pulverized for 10 hours, mixed and dried with a wet ball mill of 49.6 mol% in terms of conversion and 0.8 mol% in terms of SrO, and then pre-baked by holding at 950 ° C. for 4 hours. This was pulverized with a wet ball mill for 24 hours, then granulated with a spray dryer, dried, and held in an electric furnace in an atmosphere of 2% oxygen concentration at 1270 ° C. for 6 hours to perform main 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.
[0292]
Next, R represented by (Chemical Formula 1) ₁ , R ₂ Is a methyl group, ie (CH _Three ) ₂ SiO _2/2 The unit is 15.4 mol%, R represented by (Chemical Formula 2) _Three Is a methyl group, ie CH _Three SiO _3/2 250 g of polyorganosiloxane having a unit of 84.6 mol%, CF _Three CH ₂ CH ₂ Si (OCH _Three ) _Three 21 g was 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.
[0293]
[Chemical 1]
[0294]
[Chemical 2]
[0295]
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.
[0296]
(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.
[0297]
Table 1 shows the characteristics of the resin particles obtained in the prepared resin particle dispersion (RL1, RL2, RL3, RH1, RH2, RH3, RH4, RH5, RH6). “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.
[0298]
[Table 1]
[0299]
(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 8 g of acrylic acid was added to 440 g of ion-exchanged water, and 7.2 g of a nonionic surfactant (manufactured by Sanyo Kasei Co., Ltd .: Nonipol 400). , An anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen S20-F (20 wt% aqueous solution concentration)) 24 g (substantial anion amount 4.8 g) and dodecanethiol 8 g were dispersed, and potassium persulfate 4 0.5 g was added and emulsion polymerization was carried out at 78 ° C. for 3 hours. Thereafter, aging treatment was further performed at 90 ° C. for 4 hours to prepare a resin particle dispersion RL1 in which resin particles having a median diameter of 0.14 μm were dispersed. The pH of the resin dispersion at this time was 1.8.
[0300]
Table 2 shows the nonionic amount (g), the anionic amount (g), and the ratio (wt%) of the nonionic amount to the total surfactant amount used in each resin particle dispersion. In a liquid using an anionic surfactant (Daiichi Kogyo Seiyaku, Neogen S20-F (solid content 20 wt% concentration)), ion-exchanged water was adjusted so that the concentration was about 20 wt%. The weight ratio in Table 2 indicates the actual anion amount ratio.
[0301]
Tables 3 and 4 show the blending amounts of acrylic acid, potassium persulfate and the like 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. Potassium persulfate indicates parts by weight based on 100 parts by weight of the monomer component.
[0302]
[Table 2]
[0303]
[Table 3]
[0304]
[Table 4]
[0305]
(3) Preparation of pigment dispersion
Tables 5 and 6 show the pigments that are colorants used and the surfactants used.
[0306]
[Table 5]
[0307]
[Table 6]
[0308]
(A) Preparation of pigment particle dispersion PCS1
In a 1 L beaker, 308 g of ion-exchanged water and 12 g of surfactant SA3 were weighed and stirred with a magnetic stirrer until the solid content of the surfactant was dissolved. 80 g of cyan pigment particles PC1 were added to this aqueous surfactant solution, and further stirred 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 pigment particle dispersion PCS1. The pigment concentration was 20% by weight.
[0309]
Hereinafter, based on the adjustment conditions of the cyan pigment particle dispersion PCS1, black pigments, magenta pigments, yellow pigments used for the black pigment dispersions CBS1, 2, 3, magenta pigment dispersion PMS1 and yellow pigment dispersion PYS1 Table 7 shows the conditions of the surfactants.
[0310]
[Table 7]
[0311]
(4) Preparation of wax dispersion
Tables 8, 9 and 10 show the wax materials and their properties used in the preparation of the wax particle dispersion according to this example formed as examples of the preparation of the wax particle dispersion.
[0312]
[Table 8]
[0313]
[Table 9]
[0314]
[Table 10]
[0315]
(A) Preparation of wax particle dispersion WA1
FIG. 3 shows a schematic view of a stirring and dispersing device (TK Film Mix manufactured by Tokushu Kika Co., Ltd.), and FIG. 4 shows a view from above. 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 treated, and a hole is formed in the center 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 a high speed. A hole of about 1 to 5 mm is formed on the side surface of the rotating body, and the liquid to be processed can be moved. The tank is 120 ml, and about half of the liquid to be treated is charged. The speed 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 for high-pressure processing or batch processing.
[0316]
The inside of the tank was charged with 67 g of ion-exchanged water, 3 g of a nonionic surfactant (manufactured by Sanyo Kasei Co., Ltd .: Elminol NA400), 30 g of wax (W-1), and the speed of the rotating body was 30 m / s for 5 min, and then the rotational speed was increased to 50 m / s for 2 min. A wax particle dispersion WA1 was formed.
[0317]
Tables 11 and 12 show the types and characteristics of the waxes used and the surfactants used for each wax particle dispersion wax particle dispersion (WA1 to WA12) based on the adjustment conditions of the wax particle dispersion WA1. . “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. Represents.
[0318]
[Table 11]
[0319]
[Table 12]
[0320]
In a liquid using an anionic surfactant (Daiichi Kogyo Seiyaku, Neogen S20-F (20 wt% concentration)), ion-exchanged water was adjusted so that the pigment concentration was about 20 wt%. The weight ratio in the table indicates the actual anion amount ratio, and the total amount is the same amount. Further, when the waxes W13 and W14 are used, the inside of the tank is pressurized to 0.4 MPa.
[0321]
(5) Preparation of toner base
(A) Preparation of toner matrix CT2
Table 13 shows the respective compositions of the toner bases (CT2, CT3, CT4) prepared as examples of toner bases according to the present invention and the toner bases (ct1, ct5) for comparison.
[0322]
[Table 13]
[0323]
156 g of the first resin particle dispersion RL1 and 48 g of the third resin particle dispersion RH2 as a shape control in a cylindrical 2 L glass container equipped with a thermometer, a cooling pipe, a pH meter, and a stirring blade, a colorant 56 g of particle dispersion PCS1 and 60 g of wax particle dispersion WA11 were added, 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.
[0324]
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 3 hours to obtain core particles. The obtained core particle dispersion had a pH of 9.1.
[0325]
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.
[0326]
After cooling, the product (toner base material) was filtered and washed 7 times with ion-exchanged water. Thereafter, the toner base thus obtained was dried at 35 ° C. for 8 hours by a fluid drier to obtain toner base CT2.
[0327]
For toner bases ct1, CT3, CT4, and ct5, the third resin particles were changed based on the conditions of CT2, and the agglomeration of the particles was observed.
[0328]
Table 14 shows the characteristics obtained in the toner base prepared. A difference in Ts indicates a difference in softening point Ts3 between the first resin Ts1 and the third resin, and a difference in Mw indicates a value obtained by dividing Mwr3 of the third resin by Mwr3 of the first resin. 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. 2.0 to 3.63 (p%) is the content of toner particles having a particle size of 2.0 to 3.63 μm in the number-based distribution, and over 6.06 μm (v%) is a particle of 6 μm or more in the volume-based distribution. The content of toner particles having a diameter, SC × d50 (μm), is a value obtained by multiplying the shape index and the volume average particle diameter.
[0329]
[Table 14]
[0330]
In the ct1 toner, the aggregation of the core particles proceeds rapidly, so the pH of the mixed dispersion is set to 10.5. In the ct5 toner, the progress of aggregation of the core particles is slow, and the liquid is not completely transparent even after 6 hours. Also, the shape remains fairly irregular. It seems that suspended particles that do not participate in the aggregation of wax or resin particles remain.
[0331]
The SEM observation image of the shape of the ct1 toner is shown in FIG. 12, the SEM observation image of CT2 is shown in FIG. 13, the SEM observation image of CT4 toner is shown in FIG. 14, and the SEM observation image of ct5 toner is shown in FIG. CT2, CT3, and CT4 toners showed good cohesiveness and obtained a toner base having a small particle size and a narrow particle size distribution. In the sample in which the softening point of the third resin is increased, the shape tends to shift from spherical to potato.
[0332]
(B) Preparation of toner matrix CT7
Table 15 shows the compositions of the toner bases (CT7, CT8, CT9, CT10) according to the examples of the present invention prepared as examples of toner bases and the toner bases (ct6, ct11) for comparison.
[0333]
[Table 15]
[0334]
To a 2000 ml four-necked flask equipped with a thermometer, a condenser, a stirring rod, and a pH meter, 169 g of the first resin particle dispersion RL2, 35 g of the third resin particle dispersion RH2, and the colorant particle dispersion PCS1 56 g and 45 g of wax particle dispersion WA10 were added, 350 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.
[0335]
Thereafter, 1N NaOH was added to the obtained mixed dispersion to adjust the pH to 11.0 and stirred for 10 minutes. Thereafter, when the temperature was increased from 20 ° C. at a rate of 1 ° C./min and reached 80 ° C., 200 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. The temperature was raised to 90 ° C. and heat treatment was performed for 3 hours to obtain core particles. The obtained core particle dispersion had a pH of 8.7.
[0336]
Thereafter, 105 g of the second resin particle dispersion RH3 whose pH was adjusted to 9.4 was 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.
[0337]
After cooling, the product (toner base material) was filtered and washed with ion-exchanged water three times. Thereafter, the obtained toner base was dried at 40 ° C. for 6 hours with a fluid dryer to obtain toner base CT7.
[0338]
For toner bases ct6, CT8, CT9, CT10, and ct11, the third resin particles were changed based on the conditions of CT7, and the cohesiveness of the particles was observed.
[0339]
Table 16 shows the characteristics obtained in the toner base prepared.
[0340]
[Table 16]
[0341]
In the ct6 toner, the aggregation of the core particles proceeds rapidly, so the pH of the mixed dispersion is set to 10.5. In the ct11 toner, the progress of aggregation of the core particles is slow, and the liquid is not completely transparent even after 6 hours. Also, the shape remains fairly irregular. It seems that suspended particles that do not participate in the aggregation of wax or resin particles remain.
[0342]
FIG. 16 shows an SEM observation image of CT7, FIG. 17 shows an SEM observation image of CT8 toner, and FIG. 18 shows an SEM observation image of ct11 toner. In the CT7, CT8, CT9, and CT10 toners, toner bases exhibiting good cohesion and having a small particle size and a narrow particle size distribution were obtained. In the sample in which the softening point of the third resin is increased, the shape tends to shift from spherical to potato.
[0343]
(C) Preparation of toner matrix CT13
Table 17 shows the compositions of the toner bases (CT13, CT14, CT15) prepared as examples of the toner base according to the present invention and the toner base (ct12) for comparison.
[0344]
[Table 17]
[0345]
For toner bases ct12, CT13, CT14, and CT15, the third resin particles were changed based on the conditions of CT2, and the cohesiveness of the particles was observed.
[0346]
Table 18 shows the characteristics obtained in the toner base prepared.
[0347]
[Table 18]
[0348]
In the case of ct12 toner, the aggregation of the core particles progresses quickly, so the pH of the mixed dispersion is set to 11.
[0349]
CT13, CT14, and CT15 toners showed good aggregation properties. In the sample in which the softening point of the third resin is increased, the shape tends to shift from spherical to potato.
[0350]
(D) Preparation of toner matrix CT17
Table 19 shows the respective compositions of the toner bases (CT17, CT18) and toner bases (ct16, ct19) for comparison according to the examples of the present invention prepared as toner base preparation examples.
[0351]
[Table 19]
[0352]
To a 2000 ml four-necked flask equipped with a thermometer, a condenser, a stirring rod, and a pH meter, 174 g of the first resin particle dispersion RL2, 30 g of the third resin particle dispersion RH3, and the colorant particle dispersion PCS1 56 g and 70 g of wax particle dispersion WA9 were added, 350 ml of ion exchange water was added, and the mixture was mixed for 10 min 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.
[0353]
Thereafter, 1N NaOH was added to the obtained mixed dispersion to adjust the pH to 11.0 and stirred for 10 minutes. Thereafter, when the temperature was raised from 20 ° C. at a rate of 1 ° C./min and reached 90 ° C., 200 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 92 ° C. for 3 hours to obtain core particles. The obtained core particle dispersion had a pH of 8.4.
[0354]
Thereafter, 85 g of the second resin particle dispersion RH5 having a pH adjusted to 8.9 with a water temperature of 92 ° C. was added at a dropping rate of 5 g / min. Thus, particles in which the second resin particles were fused were obtained.
[0355]
For toner bases ct16, CT18, and ct19, the third resin particles were changed based on the conditions of CT17, and the cohesiveness of the particles was observed.
[0356]
Table 20 shows the characteristics obtained in the toner base prepared.
[0357]
[Table 20]
[0358]
In the case of ct16 toner, the aggregation of the core particles progresses quickly, so the pH of the mixed dispersion is set to 11.
[0359]
In CT17 and CT18 toners, toner bases exhibiting good cohesion and having a small particle size and a narrow particle size distribution were obtained. In the sample in which the blending amount of the third resin is increased, it can be seen that the shape tends to shift from spherical to potato as the amount increases. However, if the blending amount is excessively increased, the core particle aggregation proceeds slowly in the ct19 toner, and the liquid is not completely transparent even after 6 hours.
[0360]
(E) Preparation of toner matrix CTw20
For toner bases CTw20, CTw21, CTw22, CTw23, CTw24, CTw25, and CTw26, the agglomeration property of the particles was observed by changing the wax dispersion to be added based on the conditions of CT17.
[0361]
Table 21 shows the respective compositions of the toner bases (CTw20, CTw21, CTw22, CTw23, CTw24, CTw25, CTw26) according to the examples of the present invention, which were prepared as toner base preparation examples.
[0362]
[Table 21]
[0363]
Table 22 shows the characteristics obtained in the toner base prepared.
[0364]
[Table 22]
[0365]
A tendency to influence the shape can be seen depending on the melting point of the wax used. As an agglomeration method, it seems that the effect tends to appear when the resin particles, the colorant and the wax are mixed, heated, and the aggregating agent is added after reaching a certain temperature. It is considered that the influence of the wax is likely to appear by adding a flocculant in the state where a part of the resin and the wax is melted to advance the agglomeration reaction.
[0366]
When a hydrocarbon wax having a high melting point of 85 to 98 ° C. is blended, the shape tends to shift from a spherical shape to a potato shape and an indefinite shape. When a hydrocarbon wax having a melting point higher than 100 ° C. is blended, the shape becomes indefinite, and the agglomeration does not proceed partially but tends to remain cloudy. In addition, it seems that the shape of the low melting point ester wax of 68 to 85 ° C. tends to be slightly spherical.
[0367]
(6) External additive
Next, examples of external additives will be described. Table 23 shows the respective materials and characteristics of the external additives (S1, S2, S3, S4, S5, S6, S7, S8, S9) used in this example.
[0368]
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%, a carrier of 50 g and 0.1 g of silica or the like are mixed in a 100 ml polyethylene container, and 100 minutes by longitudinal rotation. ^-1 After stirring at a speed of 5 minutes for 30 minutes, 0.3 g was collected and nitrogen gas 1.96 × 10 6 was collected. ^Four [Pa] was measured by blowing for 1 minute.
[0369]
[Table 23]
[0370]
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.
[0371]
(7) Toner composition and external addition treatment
Next, a toner composition and an example of external addition processing will be described. Table 24 shows toners (TCT2 to TCT4, TCT7 to TCT10, TCT12 to TCT14, TCT17 to TCT18, TCT20 to TCT26) and toners for comparison (tct1, tct5, The material composition of each of tct6, tct10, tct11, tct15, tct16, and tct19) is shown. 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 The treatment time was 5 min and the input amount was 1 kg.
[0372]
[Table 24]
[0373]
Other black toner, magenta toner, and yellow toner used CBS2, PMS1, and PYS1 as pigments, and other compositions were the same as those of the cyan toner composition.
[0374]
FIG. 1 is a cross-sectional view showing a configuration of an image forming apparatus for forming a full-color image used in this embodiment. In FIG. 1, the outer casing of the color electrophotographic printer is omitted. The transfer belt unit 17 includes a transfer belt 12, a first color (yellow) transfer roller 10Y made of an elastic body, a second color (magenta) transfer roller 10M, a third color (cyan) transfer roller 10C, and a fourth color (black). Transfer roller 10K, drive roller 11 made of aluminum roller, second transfer roller 14 made of elastic body, second transfer driven roller 13, belt cleaner blade 16 for cleaning the toner image remaining on the transfer belt 12, and opposed to the cleaner blade A roller 15 is provided at a position to be used. At this time, the distance from the first color (Y) transfer position to the second color (M) transfer position is 70 mm (second color (M) transfer position to third color (C) transfer position, third color (C). The fourth color (K) transfer position is the same distance from the transfer position), and the peripheral speed of the photosensitive member is 125 mm / s.
[0375]
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, and the volume resistance is 10 ⁷ -10 ¹² Ω · cm, surface resistance is 10 ⁷ -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. Volume resistance is 10 ⁷ If it is smaller than Ω · cm, retransfer is likely to occur. ¹² If it is larger than Ω · cm, the transfer efficiency deteriorates.
[0376]
The first transfer roller is a carbon conductive foamed urethane roller having an outer diameter of 8 mm, and the resistance value is 10 ² -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. Resistance value is 10 ² If it is smaller than Ω, retransfer is likely to occur. 10 ⁶ Larger transfer defects are more likely to occur than 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.
[0377]
The second transfer roller 14 is a carbon conductive urethane foam roller having an outer diameter of 10 mm, and the resistance value is 10 ² -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 Resistance value is 10 ² If it is smaller than Ω, retransfer is likely to occur. 10 ⁶ Larger transfer defects are more likely to occur than 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.
[0378]
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.
[0379]
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.
[0380]
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 mixing ratio of the carrier and the toner is read by a magnetic permeability sensor (not shown) and supplied from a toner hopper (not shown) at an appropriate time. Reference numeral 5 denotes a metal magnetic blade that 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.
[0381]
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.
[0382]
The paper is transported from below the transfer unit 17, and 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 against each other. A conveyance path is formed.
[0383]
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.
[0384]
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.
[0385]
The belt is made of 30 μm Ni as a substrate, silicone rubber is 150 μm thereon, and PFA tube 30 μm is overlaid thereon.
[0386]
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.
[0387]
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.
[0388]
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 ° C. using a thermistor.
[0389]
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.
[0390]
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.
[0390]
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
[0392]
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.
[0393]
With a time lag between the first color (Y) first transfer and the second color (M) first transfer, M signal light 3M is input to the image forming unit 18M, and image formation with M toner is performed. Simultaneously with the image formation, the M toner image is transferred from the photosensitive member 1M to the transfer belt 12 by the action of the first transfer roller 10M. At this time, the first color (Y) toner is formed and the M toner is transferred. Similarly, image formation with C (cyan) and K (black) toners is performed, and a YMCK toner image is formed on the transfer belt 12 by the action of the first transfer rollers 10C and 10B simultaneously with the image formation. This is a so-called tandem method.
[0394]
On the transfer belt 12, toner images of four colors are positioned and overlapped to form a color image. After the transfer of the final B toner image, the four color toner images are collectively transferred to the paper 19 fed from a paper feed cassette (not shown) at the same time by the action of the second transfer roller 14. At this time, the transfer roller 13 was grounded, and a DC voltage of +1 kV was applied to the second transfer roller 14. The toner image transferred to the paper was fixed by a pair of fixing rollers 201 and 202. The paper was then discharged out of the apparatus through a pair of discharge rollers (not shown). The residual transfer toner remaining on the intermediate transfer belt 12 was cleaned by the action of the cleaning blade 16 to prepare for the next image formation.
[0395]
(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.
[0396]
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 nitrogen gas was 1.96 × 10 6. ^Four Measurement was performed by blowing at Pa for 1 minute.
[0397]
Table 25 shows the two-component developers (DCT2 to DCT4, DCT7 to DCT9, DCT12 to DCT14, DCT17 to DCT18, DCT20 to DCT26) used in this example and the comparative examples. For each of the agents (dct1, dct5, dct6, dct10, dct15, dct16, dct19), the composition of the toner and carrier as a two-component developer, and the results of evaluating and evaluating 100,000 sheets running durability test on A4 size paper Show. In the table, “A” is very good, “B” is good, “C” is somewhat problematic, and “D” is problematic.
[0398]
[Table 25]
[0399]
The two-component developers DCT2 to DCT4, DCT7 to DCT9, DCT12 to DCT14, DCT17 to DCT18, and DCT20 to DCT26 according to the embodiments of the present invention are on the photoreceptor when the 100,000 sheets running durability test is performed on A4 size paper. As for toner filming, the level of practically no problem. In addition, toner filming on the transfer belt was at a level causing no practical problem. Further, no cleaning failure of the photoconductor and the transfer belt occurred. Even in a full-color image in which the three colors overlap, no paper wrapping around the fixing belt occurred.
[0400]
Further, regarding the image density before and after the running test, the two-component developers according to the examples of the present invention all obtained high-density images having an image density of 1.3 or more. Even after the endurance test of 100,000 A4 stencil sheets, the fluidity of the two-component developer was stable, and the image density showed stable characteristics with little change of 1.3 or more.
[0401]
In addition, regarding the non-image area fogging and the entire surface solid image uniformity, the two-component developers according to the examples of the present invention have no high image density, no non-image area fogging, and no toner scattering. , High resolution. Further, the uniformity when taking the entire solid image at the time of development was also good.
[0402]
In addition, no abnormal image of the vertical streak occurred even during continuous use. Further, the spent component of the toner component on the carrier hardly occurred. In addition, there is little change in carrier resistance and a decrease in charge amount. In addition, the rise of charge is good when toner is rapidly replenished by continuously taking a solid image, and the phenomenon that fog increases in a high humidity environment is also observed. I couldn't. Moreover, even in long-term use, a high saturation charge amount could be maintained for a long time. Moreover, there was almost no change in the charge amount under low temperature and low humidity.
[0403]
Further, with regard to transferability (character skipping during transfer, reverse transfer, and transfer skipping), the two-component developers according to the examples of the present invention were at a level where there was no practical problem with skipping. In addition, no transfer failure occurred even in a full-color image in which the three colors overlapped. The transfer efficiency was about 95%.
[0404]
In terms of fog and character skipping during transfer, DCT3, DCT7 to DCT9, DCT13 to DCT14, DCT17 to DCT18, and DCT20 to DCT24 are particularly better.
[0405]
Even if the mixing ratio of the toner and the carrier is changed to 5 to 20% by weight, the two-component developer according to the embodiment of the present invention has little change in image quality such as image density and ground fogging, and can control the toner density widely. Became possible.
[0406]
On the other hand, the two-component developer (dct5, dct10, dct15, dct19) for comparison causes toner filming on the photoreceptor in the running durability test. In addition, the image density before and after the running test is low, the image density is lowered after long-term use, or the fog in the non-image area tends to increase. Further, when the entire surface was continuously taken and the toner was replenished rapidly, the charge decreased and the fog increased. In particular, the phenomenon worsened in a high humidity environment. This is probably due to the influence of wax particles and resin particles that do not participate in the aggregation reaction.
[0407]
In the two-component developer (dct1, dct6, dct11, dct16) for comparison, a cleaning failure on the photoconductor occurred in the running test.
[0408]
Next, Table 26 shows the evaluation results for the fixing property, non-offset property, high-temperature storage stability, and paper wrapping property around the fixing belt in a full-color image. In the table, “G” indicates that the evaluation result is good, and “F” indicates that there is a problem. Here, the adhesion amount 1.2 mg / cm ² With a fixing device using a solid image of a process speed of 125 mm / s and a belt not coated with oil, the OHP film transmittance (fixing temperature 160 ° C.), the minimum fixing temperature, and the offset phenomenon occurrence temperature at high temperature were measured. . Further, in the storage stability test at a high temperature, the state of the toner after being left at 50 ° C. for 24 hours was evaluated. The film transmittance for OHP was measured with a spectrophotometer U-3200 (Hitachi, Ltd.) for the transmittance of 700 nm light.
[0409]
[Table 26]
[0410]
The toners TCT2 to TCT4, TCT7 to TCT9, TCT12 to TCT14, TCT17 to TCT18, and TCT20 to TCT21 according to the examples of the present invention have good OHP film transmittance of 70% or more. Met. As for non-offset properties, non-offset temperature range is obtained in a wide range of 140 to 200 ° C. or higher in a fixing roller that does not use oil, and the fixing temperature range (range from the lowest fixing temperature to the high temperature offset phenomenon occurrence temperature). ) Was wide. Note that the offset phenomenon did not occur even with 200,000 full-color images of plain paper. Further, the surface deterioration phenomenon of the belt was not observed even if the oil was not applied with a silicone resin or fluororesin type fixing belt. In addition, regarding the high-temperature storage stability, almost no aggregation was observed in the storage stability at 50 ° C. for 24 hours. Moreover, jamming of the OHP film at the fixing nip portion did not occur with respect to the winding property of the paper around the fixing belt.
[0411]
For comparison toners tct5, tct10, tbt15, and tbt19 toners, the high temperature non-offset property was weak and the margin of the fixable region was narrow. This seems to be due to the influence of wax particles and resin particles that do not participate in aggregation during the aggregation reaction.

Claims (20)

A toner containing toner base particles and an external additive,
In the aqueous medium, the toner base particles include at least binder resin particles as first resin particles, shape-adjusting resin particles for adjusting the shape of toner as third resin particles, colorant particles, and To the core particles produced by agglomerating the wax particles,
Fusing the coated resin particles that are the second resin particles,
The toner according to claim 1, wherein a softening point of the shape-adjusting resin particles and the coating resin particles is higher than a softening point of the binder resin particles. The toner base particles are magnified 1000 times with a microscope, 100 maximum lengths and projected areas are measured, and the shape index (SC) determined by the following formula is in the range of 1.25 to 1.55. The toner according to claim 1.
SC (shape index) = π · d ² / (4 · A)
d: Maximum length of toner particles A: Projected area of toner particles π: Circumference ratio   The toner according to claim 1, wherein the softening point of the binder resin particles is in a range of 80 to 130 ° C., and the softening points of the shape-adjusting resin particles and the coating resin particles are in a range of 140 to 180 ° C., respectively.   2. The toner according to claim 1, wherein Ts1 + 30 ° C. ≦ Ts3 ≦ Ts1 + 80 ° C. is satisfied, where Ts3 (° C.) is the softening point of the third resin particles and Ts1 (° C.) is the softening point of the first resin particles. .   The weight average molecular weight in the gel permeation chromatogram of the third resin particle is Mwr3, and the weight average molecular weight of the first resin particle is Mwr1, and Mwr1 × 1.5 ≦ Mwr3 ≦ Mwr1 × 12 is satisfied. The toner according to 1.   The toner according to claim 1, wherein the blending ratio of the third resin particles is 5 to 50 parts by weight with respect to 100 parts by weight of the first resin particles.   The wax particles include at least a first wax and a second wax, and an endothermic peak temperature (referred to as a melting point Tsw1 (° C.)) of the first wax by DSC method (differential scanning calorimeter) is 50 to 90 ° C., 2. The toner according to claim 1, wherein the second wax has an endothermic peak temperature (melting point Tsw2 (° C.)) by DSC of 80 to 120 ° C. 2.   The wax particles include at least a first wax and a second wax, and the first wax is an ester composed of at least one selected from 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, comprising a wax, and the second wax comprises an aliphatic hydrocarbon wax.   The wax particles include 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 carbonization. The toner according to claim 1, comprising a hydrogen-based wax.   The endothermic peak temperature (melting point Tsw1 (° C.)) of the first wax by DSC method is 50 to 90 ° C., and the endothermic peak temperature (melting point Tsw2 (° C.)) of the second wax by DSC method is 80 to 120. The toner according to any one of claims 7 to 9, which is at ° C.   The toner according to claim 7, wherein the melting point of the second wax is higher by 5 ° C. or more and 50 ° C. or less than the melting point of the first wax. The toner base particles have a volume average particle size of 3 to 6 μm, a volume-based variation coefficient of 10 to 25%, and a content of particles having a particle size of 2.0 to 3.63 μm in the number-based distribution is 10 to 85 particles. %, Particles having a particle size of 3.5 to 4.53 μm in the volume-based distribution are contained in 25 to 75% by volume, particles having a particle size of 6.06 μm or more in the volume-based distribution are contained in 5% by volume or less,
When the volume% of particles having a particle diameter of 3.5 to 4.53 μm in the volume-based distribution is V34, and the number% of particles having a particle diameter of 3.5 to 4.53 μm in the number-based distribution is P34, The toner according to claim 1, wherein P34 / V34 is 0.4 to 2.2.   2. The toner according to claim 1, wherein the external additive is an inorganic fine powder having an average particle diameter of 6 nm to 200 nm and is added in an amount of 1 to 6 parts by weight with respect to 100 parts by weight of the toner base particles. A method for producing a toner including toner base particles and an external additive,
The toner base particles include, in an aqueous medium, at least a first resin particle dispersion in which binder resin particles are dispersed, and a third resin particle dispersion in which resin particles for adjusting the shape of the toner are dispersed. And mixing the colorant particle dispersion in which the colorant particles are dispersed and the wax particle dispersion in which the wax particles are dispersed, and agglomerating to produce core particles;
Adding a second resin particle dispersion in which coating resin particles are dispersed to the core particle dispersion containing the generated core particles, and fusing the second resin particles to the core particles. And a method for producing the toner.   The pH of the second resin particle dispersion is adjusted to an alkaline state, and the second resin particle dispersion is added to a core particle dispersion having a pH value of 7 to 10. A method for producing the toner according to claim.   The toner production method according to claim 15, wherein the pH value of the second resin particle dispersion is in the range of 7.5 to 10.5.   The toner manufacturing method according to claim 15, wherein the pH value of the second resin particle dispersion 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.   The method for producing a toner according to claim 14, wherein the softening point of the binder resin particles is in a range of 80 to 130 ° C., and the softening points of the shape-adjusting resin particles and the coating resin particles are in a range of 140 to 180 ° C., respectively. .   The method for producing a toner according to claim 14, wherein the dispersant for dispersing at least one selected from the colorant and the wax is a surfactant containing a nonionic surfactant. The surfactant used for dispersing at least one dispersion selected from the first resin particle dispersion, the third resin particle dispersion, and the second resin particle dispersion is a nonionic surfactant, And,
The method for producing a toner according to claim 14, wherein the dispersant for dispersing the colorant and the wax is a surfactant containing a nonionic surfactant.