JP2015079195A - Manufacturing method of toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner that is excellent in a heat-resistant storage property, durability, and environmental stability.SOLUTION: A manufacturing method of toner according to an embodiment of the present invention includes the steps of: dissolving or dispersing a composition including a binder resin and/or a precursor of the binder resin, colorant, and mold release agent in an organic solvent to prepare a first liquid; and a step of dispersing the first liquid in an aqueous medium to prepare a second liquid, where the aqueous medium includes resin particles and surfactant and has a zeta potential ζ of 1.0 mV or more and 4.0 mV or less.

Description

  The present invention relates to a toner manufacturing method.

  In recent years, development of environment-friendly electrophotographic apparatus aiming at resource saving has been active, and as a toner, reduction of consumption raw materials and waste products at the time of manufacture is required.

  Conventionally, a dissolution suspension method has been used as a toner production method.

  In the dissolution suspension method, since an organic solvent is used, an excessive amount of a surfactant is used, and there is a problem in that the charge amount in a high temperature and high humidity environment is lowered and the environmental stability is lowered.

  In Patent Document 1, a toner material solution or dispersion prepared by dissolving or dispersing a toner material in an organic solvent is emulsified or dispersed in an aqueous medium in which resin fine particles are dispersed to prepare an emulsion or dispersion. Then, a method for producing a toner including at least mixing an emulsified or dispersed liquid with an aqueous medium is disclosed.

  However, when the content of the surfactant in the aqueous medium is reduced, the content of the resin fine particles in the toner is reduced, and there is a problem that the heat resistant storage stability and durability of the toner are lowered.

  An object of one embodiment of the present invention is to provide a toner that is excellent in heat-resistant storage stability, durability, and environmental stability in view of the above-described problems of the related art.

  According to one embodiment of the present invention, in the method for producing a toner, a first liquid is obtained by dissolving or dispersing a binder resin and / or a binder resin precursor, a colorant, and a release agent in an organic solvent. And a step of dispersing the first liquid in an aqueous medium to prepare a second liquid, the aqueous medium including resin particles and a surfactant, and a zeta potential ζ of 1 It is 0.0 mV or more and 4.0 mV or less.

  According to one embodiment of the present invention, a toner excellent in heat-resistant storage stability, durability, and environmental stability can be provided.

  Next, the form for implementing this invention is demonstrated.

  The method for producing a toner comprises a step of preparing a first liquid by dissolving or dispersing a binder resin and / or a binder resin precursor, a colorant and a release agent in an organic solvent; A step of preparing a second liquid by dispersing one liquid in an aqueous medium.

  The aqueous medium includes resin particles and a surfactant.

  The zeta potential ζ of the aqueous medium is 1.0 to 4.0 mV. When the zeta potential ζ of the aqueous medium is less than 1.0 mV, when the content of the surfactant in the aqueous medium is reduced, the oil droplets of the first liquid are excessively aggregated, and the heat resistant storage stability and charging of the toner are reduced. Properties, durability and environmental stability are reduced. On the other hand, when the zeta potential ζ of the aqueous medium exceeds 4.0 mV, the cohesive force between the oil droplets of the first liquid and the resin particles decreases when the surfactant content in the aqueous medium decreases. Further, the heat resistant storage stability, durability and environmental stability of the toner are reduced.

  The zeta potential ζ of the aqueous medium can be adjusted by dissolving an inorganic salt or the like.

  The organic solvent is not particularly limited as long as the composition can be dissolved or dispersed, but toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane. , Trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, and the like. Among these, ester solvents are preferable, and ethyl acetate is particularly preferable.

  The organic solvent preferably has a boiling point of less than 150 ° C. because it can be easily removed.

  The mass ratio of the organic solvent to the composition is usually 0.4 to 3.0, preferably 0.6 to 1.4, and more preferably 0.8 to 1.2.

  Although it does not specifically limit as an aqueous medium, Water, the solvent etc. which are miscible with water are mentioned, You may use 2 or more types together. Of these, water is preferred.

  The solvent miscible with water is not particularly limited, and examples thereof include alcohol, dimethylformamide, tetrahydrofuran, cellosolve, and lower ketone.

  Examples of the alcohol include methanol, isopropanol, and ethylene glycol.

  Examples of lower ketones include acetone and methyl ethyl ketone.

  The water content in the aqueous medium is usually 75% by mass or more.

  The aqueous medium can also contain an organic solvent at a solubility or lower.

  The resin constituting the resin particles is not particularly limited as long as it can be dispersed in an aqueous medium, but is not limited to vinyl resin, polyurethane, epoxy resin, polyester, polyamide, polyimide, phenol resin, melamine resin, urea resin, An aniline resin, an ionomer resin, a polycarbonate, a silicone resin, a benzoguanamine resin and the like may be mentioned, and two or more kinds may be used in combination. Among these, vinyl resin, polyurethane, epoxy resin, or polyester is preferable because fine spherical resin particles can be easily obtained.

  Vinyl resins include styrene- (meth) acrylic acid ester copolymer, styrene-butadiene copolymer, (meth) acrylic acid-acrylic acid ester copolymer, styrene-acrylonitrile copolymer, styrene-maleic anhydride copolymer. Examples thereof include a polymer and a styrene- (meth) acrylic acid copolymer.

  Vinyl resin particles can also be synthesized using a vinyl monomer having a plurality of unsaturated groups.

  The vinyl monomer having a plurality of unsaturated groups is not particularly limited, and examples thereof include divinylbenzene and 1,6-hexanediol acrylate.

  The volume average particle size of the resin particles is usually 0.01 to 1 μm.

  The volume average particle diameter of the resin particles can be measured using a laser diffraction / scattering method.

  The method for synthesizing the resin particles is not particularly limited, but is a method of polymerizing vinyl monomers by suspension polymerization, emulsion polymerization, seed polymerization or dispersion polymerization, polyaddition or condensation of polyester, polyurethane, epoxy resin, etc. A method in which a precursor of a resin based resin (for example, a monomer or oligomer) or a solution thereof is dispersed in an aqueous medium in the presence of a dispersant and then reacted, polyaddition or condensation resin such as polyester, polyurethane, epoxy resin, etc. A method in which an emulsifier is dissolved in a precursor (eg, a monomer or oligomer) or a solution thereof, and then water is added to perform phase inversion emulsification and reaction. Resin particles obtained by pulverizing and classifying a resin synthesized by condensation or condensation polymerization using a mechanical rotary or jet pulverizer A method of dispersing in an aqueous medium in the presence of a dispersant, by spraying a solution of a resin previously synthesized by polymerization (for example, addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization) in the form of a mist Dispersing the obtained resin particles in an aqueous medium in the presence of a dispersant, a resin previously synthesized by polymerization (for example, addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization) in a solvent Then, a method of dispersing resin particles obtained by adding a poor solvent and removing the solvent in an aqueous medium in the presence of a dispersing agent, prepolymerization (for example, addition polymerization, ring-opening polymerization, polyaddition) , Addition condensation, condensation polymerization) a method of dispersing resin particles obtained by dissolving a resin synthesized by heating in a solvent and then cooling and removing the solvent in an aqueous medium in the presence of a dispersant, Pre-polymerized (eg, A method of removing a solvent after dispersing a resin solution synthesized by addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization) in an aqueous medium in the presence of a dispersant; Examples thereof include a method in which an emulsifier is dissolved in a resin solution synthesized by addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, and then water is added to perform phase inversion emulsification.

  Although it does not specifically limit as surfactant, Anionic surfactant, cationic surfactant, nonionic surfactant, amphoteric surfactant, etc. are mentioned. Among these, an anionic surfactant is preferable.

The anionic surfactants of the general formula _{C n H 2n + 1 -Ar-} SO 3 - M +
(In the formula, Ar is a phenylene group, M ⁺ is a monovalent metal ion, and n is an integer of 10 to 18.)
In alkylbenzenesulfonate represented by the general formula _{C n H 2n + 1 -O-} SO 3 - M +
(In the formula, M ⁺ is a monovalent metal ion, and n is an integer of 10 to 18.)
In alkyl sulfate represented by the general formula ^{_{C n H 2n + 1 -SO 3}} - M +
(In the formula, M ⁺ is a monovalent metal ion, and n is an integer of 10 to 18.)
And alkyl sulfonates, α-olefin sulfonates, phosphoric acid esters, alkyl carboxylates, and the like. Of these, alkyl sulfates or alkyl sulfonates are preferred.

  Examples of the cationic surfactant include amine salt type surfactants and quaternary ammonium salt type surfactants.

  Examples of amine salt type surfactants include alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, and imidazolines.

  Examples of the quaternary ammonium salt type surfactant include alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, pyridinium salts, alkylisoquinolinium salts, and benzethonium chloride.

  Examples of nonionic surfactants include fatty acid amide derivatives and polyhydric alcohol derivatives.

  Examples of amphoteric surfactants include alanine, dodecylbis (aminoethyl) glycine, bis (octylaminoethyl) glycine, N-alkyl-N, N-dimethylammonium betaine.

  The content of the surfactant in the aqueous medium is usually 0.1 to 3% by mass, and preferably 0.2 to 2.5% by mass. When the content of the surfactant in the aqueous medium is less than 0.1% by mass, the heat resistant storage stability, charging characteristics and durability of the toner may be deteriorated. May decrease.

  The aqueous medium preferably contains an inorganic salt. This improves the stability of the oil droplets in the first liquid by adjusting the salt concentration of the second liquid, adjusting the thickness of the electric double layer, and adjusting the adsorption concentration of the resin particles. Can do.

  Although it does not specifically limit as a cation which comprises inorganic salt, A sodium ion, potassium ion, calcium ion, etc. are mentioned.

  Although it does not specifically limit as an anion which comprises inorganic salt, A chloride ion, nitrate ion, sulfate ion, carbonate ion, etc. are mentioned.

  The content of the inorganic salt in the aqueous medium is usually 0.01 to 20% by mass. If the content of the inorganic salt in the aqueous medium is less than 0.01% by mass, the zeta potential of the aqueous medium may be less than 1.0 mV, and if it exceeds 20% by mass, the zeta potential of the aqueous medium is 4 May exceed 0.0 mV.

  The aqueous medium may further contain organic particles or inorganic particles.

  Although it does not specifically limit as a material which comprises organic particle, The microcrystal of a low molecular organic compound etc. are mentioned, You may use together 2 or more types.

  The material constituting the inorganic particles is not particularly limited, but silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, silica sand, clay, mica, Wollastonite, diatomaceous earth, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride, tricalcium phosphate, calcium carbonate, colloidal Examples thereof include titanium oxide, colloidal silica, and hydroxyapatite, and two or more kinds may be used in combination. Among these, hydroxyapatite synthesized by reacting sodium phosphate and calcium chloride in water in the presence of a base is preferable.

  The mass ratio of the aqueous medium to the composition is usually from 0.5 to 20, and preferably from 1 to 10. When the mass ratio of the aqueous medium to the composition is less than 0.5, the dispersibility of the first liquid may be reduced, and when it exceeds 20, the production cost may be increased.

  By dispersing the first liquid in the aqueous medium, oil droplets of the first liquid are formed in the aqueous medium.

  The disperser used for dispersing the first liquid in the aqueous medium may be either a batch type or a continuous type.

  The disperser is not particularly limited, and examples thereof include a low speed shear disperser, a high speed shear disperser, a friction disperser, a high pressure jet disperser, and an ultrasonic disperser. Among these, a continuous disperser is preferable from the viewpoint of improving productivity, and a high-speed shear disperser is preferable from the viewpoint that the particle size of oil droplets can be controlled to 2 to 20 μm.

  The rotational speed of the high-speed shearing disperser is usually 1000 to 30000 rpm, and preferably 5000 to 20000 rpm.

  The dispersion time of the high-speed shearing disperser is usually 0.1 to 5 minutes in the batch method.

  The dispersion temperature of the high-speed shearing disperser is usually 0 to 150 ° C. and preferably 40 to 98 ° C. under pressure.

  The oil droplets of the first liquid formed in the aqueous medium are converged by the oil droplets existing in the vicinity of each other. Thereby, one particle is formed from the oil droplets existing in the vicinity.

  When a high shear force is applied when dispersing the first liquid in the aqueous medium, not only the first liquid exhibits a Newtonian viscosity but also a non-Newtonian viscosity. The structural viscosity is destroyed by the force, the viscosity is close to that of a Newtonian fluid, and spherical oil droplets are formed according to the difference in interfacial tension between the first liquid and the aqueous medium.

  When the oil droplets are converged in a state where a low shear force is applied or in a stationary state, base particles having a narrow particle size distribution are obtained. This is because even when the particle size distribution of the oil droplets is wide, the oil droplets having a small particle size are associated with the oil droplets having a large particle size, so that the oil droplets having a small particle size are reduced and the particle size distribution is narrowed. it is conceivable that.

  At this time, in order to obtain deformed base particles, it is necessary to prevent flow in oil droplets during convergence.

  When the oil droplets converge, the oil droplets are released from a high shear force, and thus exhibit a non-Newtonian viscosity. When the oil droplets exhibit a structural viscosity, the structural viscosity is recovered or recovered. Drops meet. At this time, since the associated oil droplets exhibit structural viscosity, the oil droplets do not flow within the oil droplets, and the oil droplets within the associated oil droplets maintain their respective shapes, and deformed particles Form. For example, after the oil droplets converge, the oil droplets with large particle sizes maintain the shape of the oil droplets with large particle sizes within the associated oil droplets. In addition, after the oil droplets have converged, the oil droplets having a small particle size maintain the shape of the oil droplets having a small particle size while being associated with the oil droplets having a large particle size.

  Accordingly, although both the oil droplets having a large particle size and the oil droplets having a small particle size are associated, the shape of each oil droplet is relatively maintained, and deformed base particles are formed.

  In preparing the second liquid, the aqueous medium in which the first liquid is dispersed may be diluted with the aqueous medium. Thereby, aggregation of the oil droplet of a 1st liquid can be suppressed.

  At this time, the aqueous medium to be diluted may be the same as or different from the aqueous medium in which the first liquid is dispersed.

  The toner manufacturing method usually further includes a step of removing the organic solvent from the second liquid to form base particles, a step of cleaning the base particles, and a step of drying the cleaned base particles. Depending on the method, the method may further include a step of classifying the base particles.

  In order to produce deformed base particles, it is necessary to prevent flow in the oil droplets when removing the organic solvent.

  When the oil droplets exhibit non-Newtonian viscosity and structural viscosity, even if the structural viscosity is destroyed by dispersing the first liquid in the aqueous medium, the viscosity of the oil droplets recovers over time. For example, when the oil droplets are converged, even when a substantially spherical oil droplet having a large particle diameter is formed without recovering the structural viscosity, the structural viscosity is recovered over time, and the organic solvent is removed. In this case, since no flow occurs in the oil droplet, the surface area shrinkage cannot follow the uniform volume shrinkage, and deformed particles are formed.

  When removing the organic solvent, as long as the oil droplets show non-Newtonian viscosity, deformed base particles can be produced, but the oil droplets when converging the oil droplets show non-Newtonian viscosity, organic It is preferred that the oil droplets when removing the solvent exhibit non-Newtonian viscosity. When the oil droplets converge and when the organic solvent is removed, if the oil droplets exhibit a non-Newtonian viscosity, it is possible to produce deformed base particles having a small particle size.

  The method for removing the organic solvent is not particularly limited, but the temperature of the second liquid is gradually raised to evaporate and remove the organic solvent in the oil droplets, and the second liquid is sprayed into a dry atmosphere. And a method of evaporating and removing the organic solvent and the aqueous medium in the oil droplets.

  In addition, it is preferable to age | cure | ripen, after heating up a 2nd liquid gradually and evaporating and removing the organic solvent in an oil droplet.

  The method of classifying the base particles is not particularly limited, but a method of removing fine particles from the base particles before drying by a cyclone, a decanter, centrifugation, etc., a method of removing coarse particles from the base particles after drying Etc.

  The precursor of the binder resin is preferably a polymer having a group capable of reacting with an active hydrogen group, and more preferably a polyester prepolymer having an isocyanate group. As a result, the heat-resistant storage stability and low-temperature fixability of the toner can be compatible.

  At this time, when the polymer having a group capable of reacting with an active hydrogen group reacts with a compound having an active hydrogen group, a binder resin is formed, and the polyester prepolymer having an isocyanate group has an amino group. When reacted with a compound, a urea-modified polyester is formed.

  The compound having an active hydrogen group acts as an elongation agent, a crosslinking agent or the like when a polymer having a group capable of reacting with an active hydrogen group undergoes an elongation reaction, a crosslinking reaction, or the like.

  Although it does not specifically limit as an active hydrogen group, A hydroxyl group (alcoholic hydroxyl group or phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group etc. are mentioned, You may use together 2 or more types.

  Although it does not specifically limit as a polymer which has a group which can react with an active hydrogen group, A polyol resin, an acrylic resin, polyester, an epoxy resin etc. are mentioned, You may use 2 or more types together.

  Although it does not specifically limit as group which can react with an active hydrogen group, An isocyanate group, an epoxy group, carboxylic acid, an acid chloride group etc. are mentioned, You may use 2 or more types together.

  The polyester prepolymer having an isocyanate group can be synthesized by reacting a polyester having a hydroxyl group, which is a polycondensate of a polyol and a polycarboxylic acid, with a polyisocyanate.

  Although it does not specifically limit as a polyol, A diol, a trihydric or more polyol, a mixture of diol and a trihydric or more polyol, etc. are mentioned, You may use 2 or more types together. Among these, a diol or a mixture of a diol and a small amount of a trivalent or higher polyol is preferable.

  Examples of the diol include alkylene glycol (for example, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol), alkylene ether glycol (for example, diethylene glycol, triethylene glycol, Ethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol), alicyclic diols (for example, 1,4-cyclohexanedimethanol, hydrogenated bisphenol A), alkylene oxides of alicyclic diols (for example, , Ethylene oxide, propylene oxide, butylene oxide) adducts, bisphenols (eg, bisphenol A, bisphenol F, bisphenol S), Alkylene oxide phenols (e.g., ethylene oxide, propylene oxide, butylene oxide), and adducts. Among them, alkylene glycols having 2 to 12 carbon atoms, alkylene oxide adducts of bisphenols, etc. are preferable, and alkylene oxide adducts of bisphenols, mixtures of alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. Is more preferable.

  Examples of the trihydric or higher polyol include trihydric or higher aliphatic alcohols (for example, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol), and trihydric or higher polyphenols (for example, trisphenol PA, phenol novolac, Cresol novolac) and alkylene oxide (for example, ethylene oxide, propylene oxide, butylene oxide) adducts of trivalent or higher polyphenols.

In the mixture of the diol and the trihydric or higher polyol, the mass ratio of the trihydric or higher polyol to the diol is usually 1 × 10 ^{−4 to} 0.1 and 1 × 10 ^{−4 to} 0.01. preferable.

  Although it does not specifically limit as polycarboxylic acid, Dicarboxylic acid, trivalent or more polycarboxylic acid, the mixture of dicarboxylic acid and trivalent or more polycarboxylic acid, etc. are mentioned, You may use 2 or more types together. Among these, dicarboxylic acid or a mixture of dicarboxylic acid and a small amount of tricarboxylic or higher polycarboxylic acid is preferable.

  Dicarboxylic acids include alkylene dicarboxylic acids (for example, succinic acid, adipic acid, sebacic acid), alkenylene dicarboxylic acids (for example, maleic acid, fumaric acid), aromatic dicarboxylic acids (for example, phthalic acid, isophthalic acid, terephthalic acid, Naphthalenedicarboxylic acid) and the like. Among these, alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms are preferable.

  Examples of the trivalent or higher polycarboxylic acid include trivalent or higher aromatic polycarboxylic acid (for example, trimellitic acid and pyromellitic acid). Among them, trivalent or higher aromatic polycarboxylic acids having 9 to 20 carbon atoms are preferable.

  In place of polycarboxylic acid, polycarboxylic anhydride or lower alkyl (for example, methyl, ethyl, isopropyl) ester may be used.

The mass ratio of the trivalent or higher polycarboxylic acid to the dicarboxylic acid in the mixture of the dicarboxylic acid and the trivalent or higher polycarboxylic acid is usually 1 × 10 ^{−4 to} 0.1, and 1 × 10 ^{−4 to} 0. 01 is preferred.

  The molar ratio [OH] / [COOH] of the hydroxyl group to the carboxyl group in the polycondensation of the polyol and the polycarboxylic acid is usually 1 to 2, preferably 1 to 1.5, preferably 1.02 More preferably, it is 1.3.

  The polyisocyanate is not particularly limited, but aliphatic polyisocyanate (for example, tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethyl caproate, octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, tetradeca Methylene diisocyanate, trimethylhexane diisocyanate, tetramethylhexane diisocyanate), alicyclic polyisocyanates (eg, isophorone diisocyanate, cyclohexylmethane diisocyanate), aromatic diisocyanates (eg, tolylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, Diphenylene-4,4′-diisocyanate, 4 , 4′-diisocyanato-3,3′-dimethyldiphenyl, 3-methyldiphenylmethane-4,4′-diisocyanate, diphenyl ether-4,4′-diisocyanate), araliphatic diisocyanates (eg, α, α, α ′, α'-tetramethylxylylene diisocyanate), isocyanurates (for example, tris (isocyanatoalkyl) isocyanurate, tris (isocyanatocycloalkyl) isocyanurate, and the like may be used in combination.

  In place of polyisocyanate, polyisocyanate in which an isocyanate group is blocked with a phenol derivative, oxime, caprolactam, or the like can be used.

  The molar ratio [NCO] / [OH] of the isocyanate group to the hydroxyl group when the polyisocyanate and the polyester having a hydroxyl group are reacted is usually 1 to 5, preferably 1.2 to 4, preferably 1.5. More preferably, it is ~ 3. When [NCO] / [OH] is less than 1, the hot offset resistance of the toner may be lowered, and when it exceeds 5, the low-temperature fixability of the toner may be lowered.

  Content of the structural unit derived from the polyol in the polyester prepolymer which has an isocyanate group is 0.5-40 mass% normally, it is preferable that it is 1-30 mass%, and it is 2-20 mass%. Is more preferable. When the content of the constituent unit derived from the polyol in the polyester prepolymer having an isocyanate group is less than 0.5% by mass, the hot offset resistance of the toner may be reduced. When the content exceeds 40% by mass, Low temperature fixability may be reduced.

  Content of the structural unit derived from polyisocyanate in the polyester prepolymer having an isocyanate group is usually 0.5 to 40% by mass, preferably 1 to 30% by mass, and 2 to 20% by mass. More preferably. When the content of the structural unit derived from polyisocyanate in the polyester prepolymer having an isocyanate group is less than 0.5% by mass, the hot offset resistance of the toner may be deteriorated. The low-temperature fixability of the ink may deteriorate.

  The average value of the number of isocyanate groups contained in the polyester prepolymer is usually 1 or more, preferably 1.2 to 5, and more preferably 1.5 to 4. If the average number of isocyanate groups in the polyester prepolymer is less than 1, the hot offset resistance of the toner may be lowered.

  The weight average molecular weight of the polyester prepolymer having an isocyanate group is usually 3000 to 40000, preferably 4000 to 30000. When the weight average molecular weight of the polyester prepolymer having an isocyanate group is less than 3000, the heat-resistant storage stability of the toner may be lowered, and when it exceeds 40000, the low-temperature fixability of the toner may be lowered.

  In addition, the weight average molecular weight of the polyester prepolymer having an isocyanate group is a molecular weight in terms of polystyrene measured using gel permeation chromatography (GPC).

  Although it does not specifically limit as a compound which has an amino group, A diamine, a trivalent or more polyamine, amino alcohol, an amino mercaptan, an amino acid, etc. are mentioned, You may use 2 or more types together. Of these, diamine and a mixture of diamine and a small amount of trivalent or higher polyamine are preferable.

  Examples of the diamine include aromatic diamines (eg, phenylenediamine, diethyltoluenediamine, 4,4′diaminodiphenylmethane), alicyclic diamines (eg, 4,4′-diamino-3,3′dimethyldicyclohexylmethane, diaminecyclohexane, Isophoronediamine), aliphatic diamines (for example, ethylenediamine, tetramethylenediamine, hexamethylenediamine) and the like.

  Examples of trivalent or higher polyamines include diethylenetriamine and triethylenetetramine.

  Examples of amino alcohols include ethanolamine and hydroxyethylaniline.

  Examples of amino mercaptans include aminoethyl mercaptan and aminopropyl mercaptan.

  Examples of amino acids include aminopropionic acid and aminocaproic acid.

  A compound having a blocked amino group may be used instead of the compound having an amino group.

  Examples of the compound having a blocked amino group include ketimines and oxazolidones obtained by reacting a compound having an amino group with a ketone (for example, acetone, methyl ethyl ketone, methyl isobutyl ketone).

  The molar ratio [NCO] / [NHx] of the isocyanate group to the amino group in the reaction of the polyester prepolymer having an isocyanate group and the compound having an amino group is usually 1/3 to 3 and 0.5 to 2 It is preferable that it is 2 / 3-1.5. When [NCO] / [NHx] is less than 1/3, the low-temperature fixability of the toner may be lowered, and when it exceeds 3, the hot offset resistance of the toner may be lowered.

  In addition, when stopping reaction of the compound which has an amino group, and the polyester prepolymer which has an isocyanate group, a reaction terminator can be used. Thereby, the molecular weight of the urea-modified polyester can be controlled.

  Examples of the reaction terminator include monoamines (eg, diethylamine, dibutylamine, butylamine, laurylamine) and ketimines in which the amino group of the monoamine is blocked.

  The weight average molecular weight of the urea-modified polyester is usually 3000 or more, preferably 5,000 to 1,000,000, and more preferably 7,000 to 500,000. When the weight average molecular weight of the urea-modified polyester is less than 3000, the hot offset resistance of the toner may be lowered.

  The weight average molecular weight of the urea-modified polyester is a molecular weight in terms of polystyrene measured using gel permeation chromatography (GPC).

  The glass transition temperature of the urea-modified polyester is usually 30 to 70 ° C, and preferably 40 to 65 ° C. When the glass transition temperature of the urea-modified polyester is less than 30 ° C., the heat-resistant storage stability of the toner may be lowered, and when it exceeds 70 ° C., the low-temperature fixability of the toner may be lowered.

  The urea-modified polyester may have a urethane bond as well as a urea bond.

  In this case, the molar ratio of the urethane bond to the urea bond is usually from 0 to 9, preferably from 0.25 to 4, and more preferably from 2/3 to 7/3. When the molar ratio of the urethane bond to the urea bond exceeds 9, the hot offset resistance of the toner may be lowered.

  The binder resin is not particularly limited, and examples thereof include polyester (not modified), urea-modified polyester, polyol resin, acrylic resin, and epoxy resin, and two or more kinds may be used in combination. Among these, polyester is preferable from the viewpoint of low-temperature fixability of the toner and gloss of the image.

  Polyester can be synthesized by polycondensation of the aforementioned polyol and polycarboxylic acid.

  The weight average molecular weight of the polyester is usually 1000 to 30000, and preferably 1500 to 15000. When the weight average molecular weight of the polyester is less than 1000, the heat-resistant storage stability of the toner may be lowered, and when it exceeds 30000, the low-temperature fixability of the toner may be lowered.

  In addition, the weight average molecular weight of polyester is a molecular weight of polystyrene conversion measured using gel permeation chromatography (GPC).

  Content of the component whose molecular weight of polyester is less than 1000 is 8-28 mass% normally.

  The glass transition temperature of polyester is usually 35 to 70 ° C. If the glass transition temperature of the polyester is less than 35 ° C., the heat-resistant storage stability of the toner may be lowered, and if it exceeds 70 ° C., the low-temperature fixability of the toner may be lowered.

  The hydroxyl value of the polyester is usually 5 mgKOH / g or more, preferably 10 to 120 mgKOH / g, and more preferably 20 to 80 mgKOH / g. If the hydroxyl value of the polyester is less than 5 mgKOH / g, it may be difficult to achieve both heat-resistant storage stability and low-temperature fixability of the toner.

  The acid value of the polyester is usually 1 to 30 mgKOH / g, and preferably 5 to 20 mgKOH / g.

  When a polyester prepolymer having a polyester and an isocyanate group is used in combination, the mass ratio of the polyester prepolymer having an isocyanate group to the polyester is usually 5/95 to 25/75, and 10/90 to 25/75. Is preferred. When the mass ratio of the polyester prepolymer having an isocyanate group to the polyester is less than 5/95, the hot offset resistance of the toner may be deteriorated, and when it exceeds 25/75, the low-temperature fixability of the toner and the gloss of the image May decrease.

  In this case, it is preferable that the polyester is partially compatible with the polyester prepolymer having an isocyanate group, that is, has a similar structure capable of being compatible with each other. Thereby, the low-temperature fixability and hot offset resistance of the toner can be improved.

  The content of the polyester in the binder resin is usually 50 to 100% by mass, and preferably 55 to 95% by mass. When the content of the polyester in the binder resin is less than 50% by mass, the low-temperature fixability of the toner, the image strength, and the glossiness may be deteriorated.

  The urea-modified polyester may be formed by dispersing a first liquid containing a polyester prepolymer having an isocyanate group and a compound having an amino group in an aqueous medium and then reacting the polyester prepolymer having an isocyanate group. The first liquid containing a polymer may be produced by dispersing the first liquid containing a polymer in an aqueous medium containing a compound having an amino group and then reacting the first liquid containing a polyester prepolymer having an isocyanate group. After being dispersed in an aqueous medium, a compound having an amino group may be added and reacted.

  In addition, since the first liquid containing the polyester prepolymer having an isocyanate group is dispersed in an aqueous medium and then a compound having an amino group is added, a urea-modified polyester is preferentially generated on the surface of the base particle. A concentration gradient of urea-modified polyester can also be provided.

  The time for reacting the polyester prepolymer having an isocyanate group and the compound having an amino group is usually 10 minutes to 40 hours, and preferably 2 to 24 hours.

  The temperature at which the polyester prepolymer having an isocyanate group and the compound having an amino group are reacted is usually 0 to 150 ° C, and preferably 40 to 98 ° C.

  As a combination of a urea-modified polyester and a polyester, (1) a urea-modified polyester obtained by reacting a polyester prepolymer obtained by reacting a bicondensate of ethylene oxide with 2 moles of bisphenol A and a polycondensate of isophthalic acid with isophorone diisocyanate; Polyester prepolymer obtained by reacting bisphenol A ethylene oxide 2 mol adduct and isophthalic acid polycondensate, (2) bisphenol A ethylene oxide 2 mol adduct and isophthalic acid polycondensate with isophorone diisocyanate Urea-modified polyester reacted with bisphenol A ethylene oxide 2-mole adduct and terephthalic acid polycondensate, (3) bisphenol A ethylene oxide 2-mole addition / Urea-modified polyester obtained by reacting a polycondensate of propylene oxide of bisphenol A and a polycondensate of terephthalic acid with isophorone diisocyanate and isophorone diamine, and an ethylene oxide 2 mol adduct of bisphenol A / bisphenol Propylene oxide 2-mole adduct of A and polycondensate of terephthalic acid, (4) Reacting ethylene oxide 2-mole adduct of bisphenol A / Propylene oxide 2-mole adduct of bisphenol A and polycondensate of terephthalic acid with isophorone diisocyanate A polycondensate of a urea-modified polyester obtained by reacting the polyester prepolymer thus reacted with isophoronediamine, a 2-mol adduct of bisphenol A with propylene oxide and terephthalic acid, (5 Polyester prepolymer obtained by reacting a polycondensate of bisphenol A with ethylene oxide and polycondensate of terephthalic acid with isophorone diisocyanate, a urea-modified polyester obtained by reacting with hexamethylenediamine, an ethylene oxide 2 mol adduct of bisphenol A and terephthalate (6) a urea-modified polyester obtained by reacting a polyester prepolymer obtained by reacting a polycondensate of ethylene oxide 2 mol adduct of bisphenol A and a polycondensate of terephthalic acid with isophorone diisocyanate with hexamethylenediamine, and bisphenol A Ethylene oxide 2 mol adduct / bisphenol A propylene oxide 2 mol adduct and terephthalic acid polycondensate, (7) bisphenol A ethylene oxide 2 mol adduct and And a polyester prepolymer obtained by reacting a polycondensate of terephthalic acid with isophorone diisocyanate, and a urea-modified polyester obtained by reacting ethylenediamine with ethylenediamine, 2-mole adduct of bisphenol A and polycondensate of terephthalic acid, (8) bisphenol A Of a polyester prepolymer obtained by reacting a polycondensate of ethylene oxide with 2 mol of an ethylene oxide and diphenylmethane diisocyanate with hexamethylene diamine, an ethylene oxide 2 mol adduct of bisphenol A and isophthalic acid. Polycondensate, (9) bisphenol A ethylene oxide 2-mole adduct / bisphenol A propylene oxide 2-mole adduct and terephthalic acid / dodecenyl succinic anhydride polycondensate A urea-modified polyester obtained by reacting a polyester prepolymer reacted with diphenylmethane diisocyanate with hexamethylenediamine, an ethylene oxide 2-mole adduct of bisphenol A / a propylene oxide 2-mole adduct of bisphenol A and a polycondensate of terephthalic acid, ( 10) Urea-modified polyester obtained by reacting a polyester prepolymer obtained by reacting a polycondensate of ethylene oxide with bisphenol A and a polycondensate of isophthalic acid with toluene diisocyanate with hexamethylene diamine, and a 2-mole adduct of bisphenol A with ethylene oxide. And a polycondensate of isophthalic acid.

  The binder resin may contain a crystalline resin.

  The crystalline resin is preferably a crystalline polyester.

  The crystalline resin has crystallinity and exhibits a heat-melting characteristic in which the viscosity rapidly decreases near the fixing start temperature. For this reason, the toner containing the crystalline resin has good heat-resistant storage stability due to the crystallinity of the crystalline resin until just before the melting start temperature, and the viscosity of the crystalline resin rapidly decreases at the melting start temperature. Therefore, the low-temperature fixability is also good. In addition, a toner containing a crystalline resin has a large difference between the minimum fixing temperature and the hot offset occurrence temperature.

  Although it does not specifically limit as an alcohol component used when synthesize | combining crystalline polyester, A C2-C6 diol compound (for example, 1, 4- butanediol, 1, 6-hexanediol) etc. are mentioned.

  The content of the diol compound having 2 to 6 carbon atoms in the alcohol component is usually 80 mol% or more and preferably 85 mol% or more.

  Examples of the acid component used when synthesizing the crystalline polyester include maleic acid, fumaric acid, and succinic acid.

  The colorant is not particularly limited as long as it is a dye or a pigment. Carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher , Yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Vulcan fast yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Phi Sayred, parachloroortonite Aniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine B, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R , Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Tolujing Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo red B, thioindigo maroon, oil red, quinacridone red, pyrazolone red Polyazo Red, Chrome Vermillion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), indigo, ultramarine blue, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Lid Russianine green, anthraquinone green, titanium oxide, zinc white, litbon, etc. may be mentioned, and two or more kinds may be used in combination.

  The content of the colorant in the toner is usually 1 to 15% by mass, and preferably 3 to 10% by mass. When the content of the colorant in the toner is less than 1% by mass, the coloring power of the toner may be reduced. When the content exceeds 15% by mass, poor pigment dispersion occurs and the coloring power of the toner decreases. Or the electrical characteristics of the toner may deteriorate.

  The pigment may be used as a master batch combined with a resin.

  The resin is not particularly limited, but a polymer of styrene or its substitute, a styrene copolymer, polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin , Epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid, rosin, modified rosin, terpene resin, aliphatic hydrocarbon resin, alicyclic hydrocarbon resin, aromatic petroleum resin, etc. You may use together.

  Examples of the polymer of styrene or a substituted product thereof include polystyrene, poly p-chlorostyrene, and polyvinyl toluene.

  As the styrene copolymer, styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, Styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate Copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile- Indene copolymer, styrene-mer Ynoic acid copolymer, styrene - maleic acid ester copolymers and the like.

  The master batch can be manufactured by applying high shear force to the resin and the pigment and mixing or kneading them. At this time, it is preferable to add an organic solvent in order to enhance the interaction between the pigment and the resin. Also, a so-called flushing method is preferable in that a wet cake of a pigment can be used as it is and does not need to be dried. The flushing method is a method of removing water and an organic solvent after applying a high shear force to a pigment aqueous paste together with a resin and an organic solvent to mix or knead the pigment and transfer the pigment to the resin side.

  Although it does not specifically limit as a high shear disperser which applies a high shear force, A three roll mill etc. are mentioned.

  Although it does not specifically limit as a mold release agent, The wax which has a carbonyl group, polyolefin wax, a long chain hydrocarbon, etc. are mentioned, You may use 2 or more types together. Among these, a wax having a carbonyl group is preferable.

  Examples of the wax having a carbonyl group include polyalkanoic acid esters (for example, carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18-octadecanediol distearate), polyalkanol esters (eg, tristearyl trimellitic acid, distearyl maleate), polyalkanoic acid amides (eg dibehenyl amide), polyalkylamides (eg trimellitic acid) Tristearylamide), dialkyl ketones (for example, distearyl ketone) and the like. Of these, polyalkanoic acid esters are preferred.

  Examples of the polyolefin wax include polyethylene wax and polypropylene wax.

  Examples of the long chain hydrocarbon include paraffin wax and sazol wax.

  The melting point of the release agent is usually 40 to 160 ° C, preferably 50 to 120 ° C, and more preferably 60 to 90 ° C. When the melting point of the release agent is less than 40 ° C., the heat-resistant storage stability of the toner may be lowered, and when it exceeds 160 ° C., the low-temperature fixability of the toner may be lowered.

  The melt viscosity at a temperature 20 ° C. higher than the melting point of the release agent is usually 5 to 1000 cps, and preferably 10 to 100 cps. If the melt viscosity at a temperature 20 ° C. higher than the melting point of the release agent is less than 5 cps, the releasability of the toner may be reduced, and if it exceeds 1000 cps, the hot offset resistance and low-temperature fixability of the toner will be reduced. There are things to do.

  The content of the release agent in the toner is usually 40% by mass or less, and preferably 3 to 30% by mass. When the content of the release agent in the toner exceeds 40% by mass, the fluidity of the toner may be lowered.

  The toner may further contain a charge control agent, a fluidity improver, a cleaning property improver, a magnetic material, and the like.

  The charge control agent is not particularly limited, but triphenylmethane dye, molybdate chelate pigment, rhodamine dye, alkoxy amine, quaternary ammonium salt (including fluorine-modified quaternary ammonium salt), alkylamide, phosphorus Simple substance or compound thereof, tungsten simple substance or compound thereof, fluorine-based surfactant, salicylic acid metal salt, salicylic acid derivative metal salt, quinacridone, azo pigment, sulfonic acid group, carboxyl group, quaternary ammonium base polymer A compound etc. are mentioned and you may use 2 or more types together.

  Commercially available charge control agents include quaternary ammonium salt Bontron P-51, oxynaphthoic acid metal complex E-82, salicylic acid metal complex E-84, phenolic condensate E-89 (above, Orient Chemical Co., Ltd.) quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, Hodogaya Chemical Co., Ltd.), quaternary ammonium salt copy charge PSY VP2038, triphenylmethane derivative copy blue PR, quaternary ammonium salt copy charge NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, boron complex LR-147 (manufactured by Nippon Carlit), and the like.

  The charge control agent may be melt-kneaded together with the master batch.

The mass ratio of the charge control agent to the binder resin is usually 1 × 10 ^{−3 to} 0.1, and preferably 2 × 10 ^{−3 to} 0.05. If the mass ratio of the charge control agent to the binder resin is less than 1 × 10 ⁻³ , the chargeability of the toner may be reduced, and if it exceeds 0.1, the fluidity of the toner may be reduced or the image density May decrease.

  The material constituting the fluidity improver is not particularly limited, but silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, silica sand, clay, Examples include mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride, etc. May be.

  The average primary particle size of the fluidity improver is usually 5 nm to 2 μm, and preferably 5 to 500 nm.

The BET specific surface area of the fluidity improver is usually 20 to 500 m ² / g.

  The BET specific surface area of the fluidity improver can be measured by a BET multipoint method by adsorbing nitrogen gas to the surface of the sample using a specific surface area measuring device Tristar 3000 (manufactured by Shimadzu Corporation).

  The content of the fluidity improver in the toner is usually 0.01 to 5.0% by mass, and preferably 0.01 to 5.0% by mass.

  The fluidity improver may be surface-treated with a hydrophobizing agent. Thereby, the fall of the fluidity | liquidity and charging property in high humidity can be suppressed.

  The hydrophobizing agent is not particularly limited, but includes a silane coupling agent, a silylating agent, a silane coupling agent having a fluorinated alkyl group, an organic titanate coupling agent, an aluminum coupling agent, silicone oil, and a modification. Silicone oil etc. are mentioned.

  The cleaning property improver is not particularly limited, and examples thereof include fatty acid metal salts such as zinc stearate and calcium stearate, polymer particles synthesized by soap-free emulsion polymerization such as polymethyl methacrylate particles and polystyrene particles.

  The volume average particle diameter of the polymer particles is usually 0.01 to 1 μm.

  Although it does not specifically limit as a magnetic material, Iron, magnetite, a ferrite, etc. are mentioned.

  Components other than the binder resin and the polymer capable of reacting with the active hydrogen group may be added when dispersing the resin particles during preparation of the aqueous medium, or may be dissolved or dispersed in an organic solvent. You may let them.

  The toner production method usually further comprises a step of mixing the base particles with particles of a colorant, a release agent, a charge control agent, a fluidity improver, a cleaning property improver, a magnetic material, etc., if necessary. The method may further include a step of applying a mechanical impact force. By applying a mechanical impact force, it is possible to suppress the detachment of particles from the surface of the base particle.

  The method of applying the mechanical impact force is not particularly limited, but a method of applying an impact force to the mixture with a blade rotating at high speed, the mixture is injected into a high-speed air stream, and the particles are accelerated or mixed particles. The method of making it collide with a collision board is mentioned.

  As a device for applying mechanical impact force, an ong mill (manufactured by Hosokawa Micron Co., Ltd.), an I-type mill (manufactured by Nippon Pneumatic Co., Ltd.) has been modified to reduce the pulverization air pressure, and a hybridization system (Nara Machinery Co., Ltd.). Kryptron system (manufactured by Kawasaki Heavy Industries, Ltd.), automatic mortar and the like.

  The volume average particle size of the toner is usually 3 to 8 μm, and preferably 4 to 7 μm.

  The ratio of the volume average particle diameter to the number average particle diameter of the toner is usually from 1.05 to 1.25, and preferably from 1.05 to 1.20.

  The volume average particle size and number average particle size of the toner can be measured using a particle size measuring device Multisizer II (manufactured by Beckman Coulter, Inc.).

  The average circularity of the toner is usually 0.90 to 0.98, preferably 0.94 to 0.97.

  The content of particles having a circularity of 0.97 or more in the toner is usually 10% or less.

  The average circularity can be measured using a flow type particle image analyzer FPIA-2100 (manufactured by Sysmex Corporation).

  The softening temperature of the toner is usually 30 ° C. or higher, and preferably 50 to 90 ° C. When the softening temperature of the toner is less than 30 ° C., the heat resistant storage stability of the toner may be lowered.

  The starting temperature of the outflow of toner is usually 60 ° C. or higher, and preferably 80 to 120 ° C. When the toner flow start temperature is less than 60 ° C., the heat resistant storage stability and offset resistance of the toner may be lowered.

  The 1/2 method softening point of the toner is usually 90 ° C. or higher, preferably 100 to 170 ° C. If the 1/2 method softening point of the toner is less than 90 ° C., the offset resistance of the toner may be lowered.

  The softening temperature, outflow start temperature, and 1/2 method softening point of the toner can be measured using an elevated flow tester CFT500 type (manufactured by Shimadzu Corporation).

  The glass transition temperature of the toner is usually 40 to 70 ° C, and preferably 45 to 65 ° C. When the glass transition temperature of the toner is less than 40 ° C., the heat-resistant storage stability of the toner may be lowered, and when it exceeds 70 ° C., the low-temperature fixability of the toner may be lowered.

  The glass transition temperature of the toner can be measured using a differential scanning calorimeter DSC-60 (manufactured by Shimadzu Corporation).

The BET specific surface area of the toner is usually 0.5 to 8.0 m ² / g, and preferably 0.5 to 7.5 m ² / g. When the BET specific surface area of the toner is less than 0.5 m ² / g, the resin particles may cover the surface of the base particles closely, and the low-temperature fixability of the toner may be lowered. On the other hand, when the BET specific surface area of the toner exceeds 8.0 m ² / g, the resin particles may hinder the release of the release agent, and the hot offset resistance of the toner may decrease.

  The BET specific surface area of the toner can be measured by a BET multipoint method by adsorbing nitrogen gas to the surface of the sample using a specific surface area measuring device Tristar 3000 (manufactured by Shimadzu Corporation).

  The acid value of the toner is usually from 0.5 to 40 mgKOH / g, preferably from 3 to 35 mgKOH / g, and more preferably from 5 to 30 mgKOH / g.

  The color of the toner is not particularly limited, and examples thereof include black, cyan, magenta, and yellow.

  The toner can be used for image formation by electrophotography.

  The developer has toner and may be a one-component developer made of toner, or a two-component developer made of toner and carrier.

  The carrier preferably has a protective layer formed on the surface of the core.

  The material constituting the core material is not particularly limited, and examples thereof include a manganese-strontium (Mn—Sr) material and a manganese-magnesium (Mn—Mg) material having a mass magnetization of 50 to 90 emu / g. Two or more species may be used in combination. Among them, in view of image density, a highly magnetized material such as iron having a mass magnetization of 100 emu / g or more and magnetite having a mass magnetization of 75 to 120 emu / g is preferable. Further, the copper-zinc (Cu—Zn) having a mass magnetization of 30 to 80 emu / g is advantageous in that it can weaken the hitting of the photoconductor in which the toner is in a spiked state, and is advantageous in improving the image quality. Weakly magnetized materials such as system materials are preferred.

  The volume median diameter (D50) of the core material is usually 10 to 150 μm, and preferably 40 to 100 μm. When the volume median diameter (D50) of the core material is less than 10 μm, carrier scattering may occur, and when it exceeds 150 μm, toner scattering may occur.

  The protective layer contains a resin.

  Although it does not specifically limit as resin, Amino resin, vinyl resin, styrene resin, halogenated olefin resin, polyester, polycarbonate, polyethylene, polyvinyl fluoride, polyvinylidene fluoride, polytrifluoroethylene, polyhexafluoropropylene, vinylidene fluoride And copolymers of acrylic monomers, copolymers of vinylidene fluoride and vinyl fluoride, fluoroterpolymers such as terpolymers of tetrafluoroethylene, vinylidene fluoride and non-fluorinated monomers, and silicone resins Two or more kinds may be used in combination.

  Examples of amino resins include urea-formaldehyde resins, melamine resins, benzoguanamine resins, urea resins, polyamide resins, and epoxy resins.

  Examples of the vinyl resin include acrylic resin, polymethyl methacrylate, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, and polyvinyl butyral.

  Examples of the styrenic resin include polystyrene and styrene acrylic copolymer.

  Examples of the halogenated olefin resin include polyvinyl chloride.

  Examples of the polyester include polyethylene terephthalate and polybutylene terephthalate.

  The protective layer may further contain a conductive powder.

  The conductive powder is not particularly limited, and examples thereof include metal powder, carbon black, titanium oxide powder, tin oxide powder, and zinc oxide powder.

  The average particle size of the conductive powder is usually 1 μm or less. When the average particle diameter of the conductive powder exceeds 1 μm, it may be difficult to control the electric resistance.

  The protective layer can be formed by applying a coating solution in which a resin is dissolved in a solvent to the surface of the core material, drying it, and baking it.

  The method for applying the coating liquid is not particularly limited, and examples thereof include a dip coating method, a spray coating method, and a brush coating method.

  Although it does not specifically limit as a solvent, Toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, butyl cellosolve acetate, etc. are mentioned.

  The baking method may be an external heating method or an internal heating method.

  The baking method is not particularly limited, and examples thereof include a method using a stationary electric furnace, a fluid electric furnace, a rotary electric furnace, a burner furnace, and a method using a microwave.

  The content of the protective layer in the carrier is usually 0.01 to 5.0% by mass. When the content of the protective layer in the carrier is less than 0.01% by mass, the protective layer may not be uniformly formed on the surface of the core material. When the content exceeds 5.0% by mass, the carriers are granulated. May occur.

  The content of the carrier in the two-component developer is usually 90 to 98% by mass, and preferably 93 to 97% by mass.

  The developer can be used for image formation by various known electrophotographic methods such as a magnetic one-component development method, a non-magnetic one-component development method, and a two-component development method.

  Examples of the present invention will be described below, but the present invention is not limited to the examples. In addition, a part means a mass part.

(Synthesis of polyester 1)
In a reaction vessel equipped with a condenser, a stirrer, and a nitrogen introduction tube, 220 parts of an ethylene oxide 2-mole adduct of bisphenol A, 561 parts of a propion oxide 3-mole adduct of bisphenol A, 218 parts of terephthalic acid, 48 parts of adipic acid, and After adding 2 parts of dibutyltin oxide, the mixture was reacted at 230 ° C. for 8 hours. Next, after reacting under reduced pressure of 10 to 15 mmHg for 5 hours, 45 parts of trimellitic anhydride was added and reacted at 180 ° C. for 2 hours to obtain polyester 1. Polyester 1 had a number average molecular weight of 2500, a weight average molecular weight of 6700, a glass transition temperature of 43 ° C., and an acid value of 25 mgKOH / g.

(Synthesis of polyester prepolymer 1)
In a reaction vessel equipped with a condenser, a stirrer and a nitrogen introduction tube, 682 parts of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, trimellitic anhydride 22 And 2 parts of dibutyltin oxide were added and reacted at 230 ° C. for 8 hours. Next, it was made to react under reduced pressure of 10-15 mHg for 5 hours, and the polyester which has a hydroxyl group was obtained. The polyester having a hydroxyl group had a number average molecular weight of 2,100, a weight average molecular weight of 9,500, a glass transition temperature of 55 ° C., an acid value of 0.5 mgKOH / g, and a hydroxyl value of 51 mgKOH / g.

  Into a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introducing tube, 410 parts of polyester having a hydroxyl group, 89 parts of isophorone diisocyanate and 500 parts of ethyl acetate were added and reacted at 100 ° C. for 5 hours to obtain polyester prepolymer 1 Got. Polyester prepolymer 1 had a free isocyanate group content of 1.35% by mass.

(Molecular weight)
First, after stabilizing the column in a 40 ° C. heat chamber, tetrahydrofuran was flowed at a flow rate of 1 mL / min. Next, 50 to 200 μL of a 0.05 to 0.6 mass% tetrahydrofuran solution of the sample was injected, and the molecular weight of the sample was measured. The molecular weight of the sample was calculated from the relationship between the logarithmic value of a calibration curve prepared in advance and the number of counts using a monodisperse polystyrene standard sample. The monodisperse standard polystyrene sample has a molecular weight of 6 × 10 ² , 2.1 × 10 ² , 4 × 10 ² , 1.75 × 10 ⁴ , 1.1 × 10 manufactured by Pressure Chemical or Toyo Soda Kogyo. Samples of ⁵ , 3.9 × 10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ and 4.48 × 10 ⁶ were used. An RI (refractive index) detector was used as the detector.

(Glass-transition temperature)
The glass transition temperature was measured using TG-DSC system TAS-100 (manufactured by Rigaku Corporation). First, about 10 mg of a sample was put in an aluminum sample container, and then the sample container was placed on a holder unit and set in an electric furnace. Next, the temperature was raised from room temperature to 150 ° C. at a rate of temperature increase of 10 ° C./min, left at 150 ° C. for 10 minutes, cooled to room temperature, and left for 10 minutes. Furthermore, the temperature was raised to 150 ° C. at a rate of temperature rise of 10 ° C./min in a nitrogen atmosphere, and the DSC curve was measured. From the obtained DSC curve, the glass transition temperature was calculated from the tangent of the endothermic curve near the glass transition temperature and the contact point of the baseline using the analysis system in the TG-DSC system TAS-100 system.

(Synthesis of ketimine 1)
Into a reaction vessel equipped with a stirrer and a thermometer, 170 parts of isophoronediamine and 75 parts of methyl ethyl ketone were added and reacted at 50 ° C. for 5 hours to obtain ketimine 1. Ketimine 1 had an amine value of 418 mgKOH / g.

(Preparation of master batch 1)
40 parts of carbon black legal 400R (Cabot) 40 parts, acid value 10 mgKOH / g, weight average molecular weight 20000, glass transition temperature 64 ° C. polyester RS801 (Sanyo Chemical Industries) 40 parts and water 30 parts, After mixing using a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.), the mixture was kneaded for 45 minutes at 130 ° C. using two rolls. Next, after rolling and cooling, a master batch 1 was obtained by pulverizing to 1 mm in diameter using a pulverizer (manufactured by Hosokawa Micron).

(Example 1)
-Preparation of the first liquid-
Into a container equipped with a stir bar and a thermometer, 378 parts of polyester 1, 110 parts of carnauba wax, 22 parts of a metal complex E-84 (manufactured by Orient Chemical Co., Ltd.) and 947 parts of ethyl acetate were added. The temperature was raised to 0 ° C. and held for 5 hours. Next, after cooling to 30 ° C. in 1 hour, 500 parts of master batch 1 and 500 parts of ethyl acetate were added and mixed for 1 hour to obtain a mixed liquid (A).

  Using 1324 parts of the mixed liquid (A), an ultra visco mill (made by Imex Co., Ltd.), a bead mill, a feeding speed of 1 kg / h, a peripheral speed of the disk of 6 m / s, and zirconia beads having a diameter of 0.5 mm. Three passes were performed under the condition of filling 80% by volume. Next, after adding 1324 parts of a 65 mass% ethyl acetate solution of polyester 1, one pass was performed under the same conditions using an ultra visco mill (manufactured by Imex Co., Ltd.) as a bead mill to obtain a mixed solution (B). The liquid mixture (B) had a solid content concentration of 53% by mass.

  In addition, the solid content density | concentration of the liquid mixture (B) was measured by heating at 130 degreeC for 30 minutes.

  Into the container, 648 parts of the mixed solution (B), 154 parts of the polyester prepolymer 1 and 6.6 parts of ketimine 1 are charged, and then 1 at 5000 rpm using a TK homomixer (manufactured by Tokushu Kika). Mixing for 1 minute gave a first solution.

-Preparation of aqueous medium-
In a reaction vessel equipped with a stirrer, a stirring blade and a thermometer, water 683 parts, sodium salt Eleminol RS-30 of sulfuric acid ester of methacrylic acid ethylene oxide adduct (manufactured by Sanyo Chemical Industries), 83 parts of styrene After adding 83 parts of methacrylic acid, 110 parts of butyl acrylate and 1 part of ammonium persulfate, the mixture was stirred at 400 rpm for 15 minutes. Next, after raising the temperature to 75 ° C. and reacting for 5 hours, 30 parts of a 1% by mass ammonium persulfate aqueous solution was added and aged at 75 ° C. for 5 hours to obtain a dispersion of vinyl resin particles. The dispersion of vinyl resin particles had a volume average particle size of 40 nm. Further, a part of the dispersion of vinyl resin particles was dried to isolate the vinyl resin particles. The vinyl resin particles had a glass transition temperature of 59 ° C. and a weight average molecular weight of 150,000.

  The volume average particle size of the dispersion of vinyl resin particles was measured using a laser diffraction / scattering particle size distribution analyzer LA-920 (manufactured by Horiba, Ltd.).

  985 parts of ion-exchanged water, 83 parts of a dispersion of vinyl resin particles, 25 parts of 48.5% by weight sodium dodecyl diphenyl ether disulfonate aqueous solution Eleminol MON-7 (manufactured by Sanyo Chemical Industries), 25 parts of 10% by weight sodium chloride aqueous solution and 90 parts of ethyl acetate was mixed to obtain an aqueous medium. The aqueous medium had a zeta potential ζ of 1.0 mV.

-Preparation of the second liquid-
To 809 parts of the first liquid, 1200 parts of an aqueous medium was added and mixed for 20 minutes at 13000 rpm using a TK homomixer (manufactured by Tokushu Kika Co., Ltd.) to obtain an emulsified slurry.

  Into a container equipped with a stirrer, 100 parts of the emulsified slurry was added, and then 20 parts of ion exchange water was added to obtain a second liquid.

-Preparation of third solution-
The second liquid was put into a container equipped with a stirrer and a thermometer, and then the solvent was removed at 30 ° C. for 8 hours to obtain a third liquid.

-Formation of base particles-
The third liquid was aged at 45 ° C. for 4 hours to form base particles to obtain a dispersed slurry.

-Cleaning, drying, and classification of base particles-
100 parts of the dispersion slurry was filtered under reduced pressure to obtain a filter cake. Next, 300 parts of ion-exchanged water was added to the filter cake, and after mixing for 10 minutes at 12000 rpm using a TK homomixer (manufactured by Tokushu Kika Co., Ltd.), the filtration operation was repeated three times to obtain a filter cake. .

  The filter cake was dried at 45 ° C. for 48 hours using a circulating dryer, and then sieved with a mesh having an opening of 75 μm to obtain base particles.

-Preparation of toner-
Using a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.), 100 parts of base particles, 0.7 part of hydrophobic silica and 0.3 part of hydrophobic titanium oxide were mixed to obtain a toner.

(Example 2)
The preparation of the aqueous medium was carried out except that 1008 parts of ion-exchanged water and 3 parts of 48.5% by weight sodium dodecyl diphenyl ether disulfonate aqueous solution were used instead of 985 parts of ion-exchanged water and 25 parts of 10% by weight sodium chloride aqueous solution. In the same manner as in Example 1, a toner was obtained. At this time, the aqueous medium had a zeta potential ζ of 4.0 mV.

(Example 3)
The preparation of the aqueous medium was carried out except that 985 parts of ion-exchanged water and 25 parts of a 10% by weight sodium chloride aqueous solution were used, except that 1000 parts of ion-exchanged water and 10 parts of a 48.5% by weight sodium dodecyl diphenyl ether disulfonate aqueous solution were used. In the same manner as in Example 1, a toner was obtained. At this time, the aqueous medium had a zeta potential ζ of 2.0 mV.

Example 4
In the preparation of the aqueous medium, instead of 985 parts of ion-exchanged water, 25 parts of 48.5% by weight sodium dodecyl diphenyl ether sodium disulfonate aqueous solution and 25 parts of 10% by weight sodium chloride aqueous solution, 1015 parts of ion-exchanged water, 48.5% by weight of dodecyl A toner was obtained in the same manner as in Example 1 except that 2.5 parts of an aqueous sodium diphenyl ether disulfonate solution and 18 parts of a 10% by mass aqueous sodium chloride solution were used. At this time, the aqueous medium had a zeta potential ζ of 2.0 mV.

(Example 5)
In the preparation of the aqueous medium, instead of 985 parts of ion-exchanged water, 25 parts of 48.5% by weight sodium dodecyl diphenyl ether sodium disulfonate aqueous solution and 25 parts of 10% by weight sodium chloride aqueous solution, 958 parts of ion-exchanged water, 48.5% by weight dodecyl A toner was obtained in the same manner as in Example 1 except that 75 parts of an aqueous sodium diphenyl ether disulfonate solution and 1 part of a 10 mass% sodium chloride aqueous solution were used. At this time, the aqueous medium had a zeta potential ζ of 2.0 mV.

(Example 6)
In the preparation of the aqueous medium, instead of 985 parts of ion-exchanged water, 25 parts of 48.5% by weight sodium dodecyl diphenyl ether sodium disulfonate aqueous solution and 25 parts of 10% by weight sodium chloride aqueous solution, 1015 parts of ion-exchanged water, 48.5% by weight of dodecyl A toner was obtained in the same manner as in Example 1 except that 2 parts of an aqueous sodium diphenyl ether disulfonate solution and 18 parts of a 10% by mass aqueous sodium chloride solution were used. At this time, the aqueous medium had a zeta potential ζ of 2.0 mV.

(Example 7)
In the preparation of the aqueous medium, instead of 985 parts of ion-exchanged water, 25 parts of 48.5% by weight sodium dodecyl diphenyl ether sodium disulfonate aqueous solution and 25 parts of 10% by weight sodium chloride aqueous solution, 953 parts of ion-exchanged water, 48.5% by weight dodecyl A toner was obtained in the same manner as in Example 1 except that 80 parts of an aqueous sodium diphenyl ether disulfonate solution and 0.8 parts of a 10% by mass aqueous sodium chloride solution were used. At this time, the aqueous medium had a zeta potential ζ of 2.0 mV.

(Comparative Example 1)
In the preparation of the aqueous medium, Example 1 and Example 1 were used except that 1005 parts of ion-exchanged water and 2.5 parts of 10% by weight sodium chloride aqueous solution were used instead of 985 parts of ion-exchanged water and 25 parts of 10% by weight sodium chloride aqueous solution. Similarly, a toner was obtained. At this time, the aqueous medium had a zeta potential ζ of 5.0 mV.

(Comparative Example 2)
In the preparation of the aqueous medium, the same procedure as in Example 1 was performed except that 980 parts of ion-exchanged water and 30 parts of a 10% by weight sodium chloride aqueous solution were used instead of 985 parts of ion-exchanged water and 25 parts of a 10% by weight sodium chloride aqueous solution. The toner was obtained. At this time, the aqueous medium had a zeta potential ζ of 0.8 mV.

(Comparative Example 3)
In the preparation of the aqueous medium, instead of 985 parts of ion-exchanged water, 25 parts of 48.5% by weight aqueous sodium dodecyl diphenyl ether disulfonate and 25 parts of 10% by weight aqueous sodium chloride, 860 parts of ion-exchanged water and 48.5% by weight of dodecyl are used. A toner was obtained in the same manner as in Example 1 except that 175 parts of an aqueous sodium diphenyl ether disulfonate solution was used. At this time, the aqueous medium had a zeta potential ζ of 5.0 mV.

(Comparative Example 4)
In the preparation of the aqueous medium, instead of 985 parts of ion exchange water, 25 parts of 48.5% by weight sodium dodecyl diphenyl ether sodium disulfonate aqueous solution and 25 parts of 10% by weight sodium chloride aqueous solution, 860 parts of ion exchange water, 48.5% by weight dodecyl A toner was obtained in the same manner as in Example 1 except that 175 parts of a sodium diphenyl ether disulfonate aqueous solution and 0.3 part of a 10 mass% sodium chloride aqueous solution were used. At this time, the aqueous medium had a zeta potential ζ of 0.8 mV.

(Zeta potential ζ of aqueous medium)
The zeta potential ζ of the aqueous medium was measured using a zeta potential measuring device DT-1200 (manufactured by Nippon Luft).

(Development of developer)
A developer was obtained by a conventional method using 5 parts of the toners of Examples 1 to 7 and Comparative Examples 1 to 4 and 95 parts of a copper-zinc ferrite carrier having an average particle diameter of 40 μm coated with a silicone resin.

  Next, using the toner, the resin particle content, heat-resistant storage stability, charging characteristics, durability, and environmental stability were evaluated. Further, durability was evaluated using a developer.

(Content of resin particles)
Using styrene derived from vinyl resin particles as a label, the amount of styrene in the thermal decomposition product of the toner was measured, and the content of vinyl resin particles in the toner was calculated. Specifically, first, a model in which the content of vinyl resin particles having a known composition is 0.01% by mass, 0.10% by mass, 1.00% by mass, 3.00% by mass, and 10.0% by mass. The toner was pyrolyzed at 590 ° C. for 12 seconds, and the pyrolysis product was analyzed using a pyrolysis gas chromatograph mass spectrometer under the following measurement conditions to determine the area of the peak derived from styrene. Next, for the toner, similarly, the area of the peak derived from styrene was determined, and the content of vinyl resin particles in the toner was calculated. The case where the content of the vinyl resin particles was 95% or more with respect to the prescription amount was evaluated as ◎, the case where it was 70% or more and less than 95%, and the case where it was less than 70% as ×.

Device body: QR-5000 (manufactured by Shimadzu Corporation)
Accessory pyrolysis furnace: JHP-3S (manufactured by Nippon Analytical Industrial Co., Ltd.)
Column: DB-1 (L = 30 m, ID = 0.25 mm, Film = 0.25 μm)
Column temperature: 40 ° C. (holding 2 min) to 300 ° C. (10 ° C./min)
Vaporization chamber temperature: 300 ° C
(Heat resistant storage stability)
After 20 mg glass bottle was filled with 10 mg of toner, the glass bottle was tapped 100 times. Next, after leaving for 24 hours in a constant temperature bath of 55 ° C. and 80% RH (high temperature and high humidity) or 10 ° C. and 15% RH (low temperature and low humidity), the penetration is determined by a penetration test (JIS K2235-1991). Measured and evaluated for heat resistant storage stability. In the case of using a high-temperature, high-humidity and low-temperature, low-humidity constant temperature bath, the smaller value of penetration is 25 mm or more, ◎, 15 mm or more and less than 25 mm, ○, or less than 15 mm Was determined as x.

(Charging characteristics)
In a test room at 20 ° C. and 50% RH, 100 parts of the carrier and 7 parts of the toner used for producing the developer were put into a stainless steel pot, and then mixed on a ball mill frame at 280 rpm for 10 minutes. Next, the charge amount of the toner was measured using a blow-off device, and the charging characteristics were evaluated. In addition, the case where the charge amount of the toner is −35 μC / g or more and less than −20 μC / g is ◎, the case where −20 μC / g or more and less than −10 μC / g or the case where −45 μC / g or more and less than −35 μC / g is given, The case of -10 μC / g or more or less than −45 μC / g was determined as x.

(durability)
Using an evaluation machine that has been tuned by modifying the image forming apparatus IPSIO Color 8100 (manufactured by Ricoh) to an oilless fixing system, the surface temperature of the fixing roller is set to 160 ± 2 ° C., and the transfer paper type is 6000 (manufactured by Ricoh). A solid image having a toner adhesion amount of 0.4 ± 0.1 mg / cm ² was formed. Next, the image density of arbitrary three places in the solid image was measured using a spectrometer 938 spectrodensitometer (manufactured by X-Rite), and the average value of the image densities of the three places was calculated. Further, after 100,000 sheets of an image chart having an image area ratio of 35% were output in a running manner, a solid image was formed in the same manner as described above, and an average value of image densities at three locations was calculated to evaluate durability. In addition, the case where the difference between the average values of the image density at three locations before and after running output is less than 0.1 is 場合, the case where it is 0.1 or more and less than 0.5 is ○, the case where it is 0.5 or more Judged as x.

(Environmental stability)
In a test room at 10 ° C., 15% RH (low temperature and low humidity) or 40 ° C., 90% RH (high temperature and high humidity), 100 parts of the carrier and 7 parts of the toner used for preparing the developer were put into a stainless steel pot, and then ball mill The mixture was mixed at 280 rpm for 5 minutes on the gantry. Next, the charge amount of the toner was measured using a blow-off device. Furthermore, the formula (charge amount in low-temperature and low-humidity test chamber−charge amount in high-temperature and high-humidity test chamber) / [(charge amount in low-temperature and low-humidity test chamber + charge amount in high-temperature and high-humidity test chamber) / 2]
From this, the environmental fluctuation rate was calculated and the environmental stability was evaluated. In addition, when the environmental fluctuation rate is less than 0.95, ◎, when 0.95 or more and less than 0.98, ◯, when 0.98 or more and less than 1, Δ when 1 or more Judged.

  Table 1 shows the evaluation results of the resin particle content, heat resistant storage stability, charging characteristics, durability, and environmental stability.

表１から、実施例１〜７のトナーは、ビニル樹脂粒子の含有量が大きく、耐熱保存性、帯電特性、耐久性及び環境安定性に優れることがわかる。

From Table 1, it can be seen that the toners of Examples 1 to 7 have a large vinyl resin particle content and are excellent in heat-resistant storage stability, charging characteristics, durability, and environmental stability.

  On the other hand, since the toner of Comparative Example 1 has a zeta potential ζ of 5.0 mV in the aqueous medium, the content of the vinyl resin particles is small, and the heat resistant storage stability, durability, and environmental stability are lowered.

  In the toner of Comparative Example 2, since the zeta potential ζ of the aqueous medium is 0.8 mV, the content of the vinyl resin particles is small, and the heat resistant storage stability, charging characteristics, durability, and environmental stability are deteriorated.

  In the toner of Comparative Example 3, the content of the surfactant in the aqueous medium is 7.0% by mass, so the content of the resin particles is large, but the zeta potential ζ of the aqueous medium is 5.0 mV. Charging characteristics deteriorate.

  In the toner of Comparative Example 4, since the surfactant content in the aqueous medium is 7.0% by mass, the resin particle content is large, but the zeta potential ζ of the aqueous medium is 0.8 mV. Environmental stability decreases.

JP 2006-178407 A

Claims (7)

A step of preparing a first liquid by dissolving or dispersing a binder resin and / or a binder resin precursor, a colorant and a release agent in an organic solvent;
Having the step of dispersing the first liquid in an aqueous medium to prepare a second liquid,
The aqueous medium contains resin particles and a surfactant, and has a zeta potential ζ of 1.0 mV to 4.0 mV.   2. The toner production method according to claim 1, wherein the aqueous medium has a content of the surfactant of 0.1% by mass or more and 3% by mass or less.   The method for producing a toner according to claim 1, wherein the surfactant is an anionic surfactant.   The method for producing a toner according to claim 3, wherein the anionic surfactant is an alkyl sulfate or an alkyl sulfonate.   The toner manufacturing method according to claim 1, wherein the aqueous medium further contains an inorganic salt.   The toner production method according to claim 5, wherein the content of the inorganic salt in the aqueous medium is 0.01% by mass or more and 20% by mass or less.   The toner manufacturing method according to claim 5, wherein the inorganic salt includes sodium ion, potassium ion, or calcium ion, and chloride ion, nitrate ion, sulfate ion, or carbonate ion.