Abstract: The method for producing a developing agent according to the invention contains subjecting the toner material dispersion liquid to mechanical shearing to make the granular mixture into fine particles, thereby providing a dispersion liquid containing fine particles having a smaller particle diameter than a particle diameter of the granular mixture. The toner material dispersion liquid is subjected to mechanical shearing under a temperature of a glass transition point Tg of the binder resin or more and a pressure of 10 MPa or more, and the resulting dispersion liquid containing the fine particles is depressurized with two or more stages while maintaining the temperature of a glass transition point Tg of the binder resin or more and then cooled to a temperature of a glass transition point Tg of the binder resin or less.

Abstract: Disclosed is a decolorizable electrophotographic toner, including: a binder resin; and a colorant which contains at least a color developable compound and a color developing agent and is covered with an outer shell so as to have a capsule structure, wherein the number ratio of particles having an equivalent circle diameter of 0.6 ?m or more and 2.5 ?m or less of the toner when measured using a flow particle image analyzer after the toner is dispersed in an aqueous medium at a ratio of 0.08% by weight and the resulting dispersion is subjected to a stirring treatment in which stirring is performed at 5000 rpm for 30 minutes using a homogenizer (T-25 digital ULTRA-TURRAX (manufactured by IKA Japan K.K., provided with a shaft generator S25N-10G)) is 30% by number or less.

Abstract: Disclosed is a producing method of a decolorizable toner, comprising dispersing a mixed composition containing encapsulated colorant particles which are particles containing a color developable compound and a color developing agent and coated with an outer shell, a polymerizable monomer, and a release agent in an aqueous medium, and subjecting the polymerizable monomer to suspension polymerization in the aqueous medium.

Abstract: There is provided a method for producing a toner that includes encapsulated erasable colored fine particles aggregated with fine particles that contain at least a binder resin and a release agent. The method includes: mixing a dispersion of erasable fine particles with an aggregating agent to form an aggregating agent-containing colored fine particle dispersion; and mixing the aggregating agent-containing colored fine particle dispersion with a fine particle dispersion that contains at least a binder resin and a release agent, so as to aggregate the aggregating agent-containing colored fine particles with the fine particles that contain at least a binder resin and a release agent. In this way, the encapsulated colored fine particles are prevented from being released from the resultant toner particles, and an erasable toner can be obtained that has a narrow particle size distribution and that produces less fogging.

Abstract: Disclosed is a toner having a controlled micro/semimacro roughness ratio, such that the toner surface has a ratio of {an average of an arithmetic average height (Ra) in a 0.5 ?m-square region} to {an average of an arithmetic average height (Ra) in a 1 ?m-square region} of 0.5 or more. As a result, the toner is provided with improved electrophotographic performances, including low environmental variation, less toner scattering, and improved image quality.

Abstract: A developing agent including a core containing an amorphous polyester resin and a fatty acid ester based wax, a shell provided on the surface of the core and containing a copolymer of an aromatic vinyl monomer and acrylic acid or an acrylic ester, and a coloring agent.

Abstract: A method for producing a developing agent contains mechanically shearing a mixture containing a polyester resin, a colorant and a releasing agent to form first fine particles, aggregating the first fine particles to form aggregated particles as a core, aggregating second fine particles containing a polyester resin onto the core to form a shell.

Abstract: A method for manufacturing a developing agent by mixing a resin having a dissociable functional group and an aqueous medium, subjecting the mixture to mechanical shearing, finely pulverizing the pulverized mixture to form resin microparticles, adding a dispersion of colorant particles, causing the resin microparticles and colorant particles to agglomerate, and forming toner particles.

Abstract: A method for producing a developing agent, includes preparing a dispersion of particles containing a binder resin and a coloring agent and forming toner particles by aggregating and fusing the particles, in which the number of coarse particles having a particle size of 0.6 ?m or larger after the solid concentration of the dispersion of particles is adjusted to 1 ppm is less than 3,000 per ?L.

Abstract: A method for producing a developing agent including heating a dispersion of a toner particle material containing a binder resin fine particle, a coloring agent particle and a dispersion medium at a temperature of a glass transition point of the binder resin or higher and adding a coagulating agent in the heated dispersion of a toner particle material to coagulate a toner material containing the binder resin fine particle and the coloring agent particle, thereby forming a coagulated particle is disclosed.

Abstract: A coarse particle containing a polyester based resin and a coloring agent is added in an aqueous medium containing a surfactant, a basic substance and an inorganic water-soluble electrolyte, and dispersion and coagulation are carried out to form a toner particle.

Abstract: A method for producing a decolorable toner comprising: forming particles containing a color former compound, a color developing agent, and a binder resin; forming first aggregated particles by aggregating and fusing the particles containing the color former compound, the color developing agent, and the binder resin in a dispersion medium; and forming second aggregated particles by aggregating and fusing the first aggregated particles and a binder resin in a dispersion medium.

Abstract: It is intended to provide a method includes the step of forming agglomerated particles by agglomerating fine particulate mixture containing a binder resin and a colorant. In the step of forming agglomerated particles, a cationic organic coagulating agent having an average molecular weight of from 1000 to 100000 is added to a liquid dispersion containing fine particles.

Abstract: According to one embodiment, a method for producing a developing agent including aggregating fine particles of a toner material containing a binder resin and a coloring agent in a dispersion liquid in which the fine particles are dispersed in an aqueous medium to form aggregated particles, and washing the aggregated particles and drying the washed aggregated particles, forming toner particles is provided. An electrical conductivity of the toner particles is measured by a toner electrical conductivity evaluation method. A sample toner is prepared by adhering an additive to surfaces of the toner particles, and a content ratio of a sodium element to a carbon element in a region to which the additive is not adhered of the toner is measured. The washing of the toner particles is repeated until each of the measurement values becomes a predetermined reference value or less.

Abstract: The dispersion liquid including toner material particles is introduced into a mechanical shearing device including a heating unit, a mechanical shearing unit, and a cooling unit, heated to a temperature not lower than the glass transition temperature of the polyester resin under a condition that satisfies the following relationship (1), subjected to mechanical shearing, and thereafter cooled, whereby fine particles are obtained. ?2<log ((A+B)/C)<2??(1) With the proviso that a volume of a portion in which the dispersion liquid flows in the heating unit and the mechanical shearing unit is expressed as A cc, a volume of a portion in which the dispersion liquid flows in the cooling unit is expressed as B cc, and a flow rate of the dispersion liquid is expressed as C cc/min.

Abstract: According to one embodiment, a method for producing a developing agent includes pulverizing a mixture in the form of coarse particles of a toner material including a coloring agent and a binder resin by mechanical shearing, aggregating and fusing the resulting fine particles. The solid content concentration in a dispersion liquid including the aggregated particles is from 5.0% to 40.0%, the volume average particle diameter of the aggregated particles is from 1.0 ?m to 10.0 ?m, and the ratio of the standard deviation to the volume average particle diameter is 30.0% or less.

Abstract: A developing agent including a toner particle obtained by using a dispersion containing a solvent, a granular mixed compound having a binder resin and a coloring agent dispersed in the solvent, and, as an additive to disperse a compound, a combination of a surfactant and a basic compound or a combination of a sulfone-based surfactant and a polycarboxylic acid-based surfactant, wherein the additive remaining in the developing agent is within a predetermine range.

Abstract: A mixture containing a binder resin and a colorant is mixed with an aqueous medium, the resulting mixture liquid is mechanically sheared to finely granulate the mixture, fine particles are formed as cores, and a coating resin layer is formed on core surfaces, to obtain toner particles.

Abstract: As a first dispersion liquid containing first fine particles and a second dispersion liquid containing second fine particles, those satisfy the relationship represented by the following formula (1) are used, and these two dispersion liquids are mixed with each other, and an aggregating agent and a pH adjusting agent are added thereto in sequence, whereby encapsulation is achieved by selective formation of core particles through aggregation of the first fine particles and shells through aggregation of the second fine particles. 15 mV?|Z2?Z1|?5 mV??(1) In the formula, Z1 and Z2 represent zeta potentials of the first dispersion liquid and the second dispersion liquid, respectively, measured when aluminum sulfate is added to each dispersion liquid in an amount of 1% by weight based on the solid content in each dispersion liquid.

Abstract: A dispersion containing a coloring agent particle is mixed in a dispersion of a radical polymerizable monomer, and a reducing agent containing an iron(II) salt is added in the presence of a polymerization initiator to polymerize the dispersed radical polymerizable monomer by the action of a generated radical, thereby not only forming a binder resin fine particle but coagulating the binder resin fine particle and the coloring agent particle to form a coagulated particle.