JP2017057286A - Aqueous polyester particle dispersion, method for producing the same, and method for producing toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: an aqueous polyester particle dispersion having aggregation stability; and a method for producing a toner, which can produce toner matrix particles having a narrow particle size distribution and can suppress generation of fine powder and coarse powder.SOLUTION: Provided is an aqueous polyester particle dispersion containing a polyvalent sulfonic acid salt-type surfactant having two or more sulfonic acid groups and an aromatic ring portion, and having polyester particles dispersed in an aqueous medium. A toner is finally obtained by generating aggregated particles of the polyester particles and particles of a vinylic resin, and melting and integrating the aggregated particles to produce toner matrix particles.SELECTED DRAWING: None

Description

  The present invention relates to an aqueous polyester particle dispersion, a method for producing the same, and a method for producing a toner.

  In recent years, in an electrophotographic image forming apparatus, an electrostatic latent image forming toner (heat-fixed at a lower temperature) for further energy saving in order to increase the printing speed and reduce the environmental load ( Hereinafter, it is simply called “toner”). As one of means for imparting such low-temperature fixability to the toner, polyester is used as the binder resin constituting the toner base particles. In such a method for producing toner base particles, an anionic surfactant having a single sulfonate (monovalent sulfonic acid type anionic surfactant) is present in an aqueous dispersion containing polyester particles. In the known method, the particles are aggregated and the obtained aggregated particles (associated particles) are integrated by melting the resin (see, for example, Patent Document 1).

JP 2008-0776519 A

  On the other hand, a styrene acrylic copolymer may be used in combination with polyester for the binder resin. In the toner base particle manufacturing method described above, if the styrene-acrylic copolymer particles coexist with the polyester particles as the resin particles to be aggregated, the cohesiveness of the two resin particles differs, resulting in variations in the degree of aggregation. As a result, the particle size of the associated particles becomes uneven, and as a result, unnecessary particles such as fine powder and coarse powder may be generated. Therefore, a technique for more appropriately controlling the particle size distribution of the toner base particles generated in the above production method is desired.

  In the above production method, an aqueous polyester particle dispersion in which polyester particles are dispersed in an aqueous medium is used as one of the materials. From the viewpoint of toner productivity, the dispersion liquid is desirably storable across lots as a material for toner base particles. However, if the dispersion liquid is left untreated, repulsive force between resin particles is weak. Or polyester particles may agglomerate. When the polyester particles are aggregated, it becomes one of the causes of non-uniformity of the particle diameter of the toner base particles in the above production method. Therefore, a water-based polyester particle dispersion having excellent aggregation stability is demanded.

  The first object of the present invention is to supply a water-based polyester particle dispersion having aggregation stability.

  A second object of the present invention is to provide a toner production method capable of producing toner base particles capable of producing fine toner particles and a coarse powder with a narrow particle size distribution of toner base particles to be generated.

  The present invention provides a water-based polyester containing water, an anionic surfactant having two or more sulfonic acid groups and an aromatic ring moiety, and polyester particles as at least one means for achieving the first object. A water-based polyester particle dispersion, which is a particle dispersion, wherein the content of the anionic surfactant with respect to the polyester is 3 to 25% by mass and the pH is 7 to 10.

  In addition, the present invention provides, as another means for at least achieving the first object, a step of dissolving polyester in an organic solvent, and an aqueous medium is added to the obtained polyester solution with stirring to add the polyester solution. A step of forming an emulsion in which droplets of the liquid are dispersed in the aqueous medium, a step of removing the organic solvent from the emulsion, an anionic surfactant having two or more sulfonic acid groups and an aromatic ring moiety, and the polyester. 2 to 20% by mass with respect to the polyester solution, the emulsion, and the step of adding to one or more selected from the group consisting of the emulsion from which the organic solvent has been removed, and a final pH of 7 to 10 Thus, the pH of one or both of the emulsion and the emulsion from which the organic solvent has been removed is adjusted with the addition of the basic compound. To provide a manufacturing method, an aqueous polyester particle dispersion and a step of adjusting by.

  Furthermore, the present invention, as a means for achieving at least the second object, produces aggregated particles by aggregating vinyl resin particles having at least sulfonic acid groups in an aqueous medium in the presence of an aggregating agent. Adding an aqueous polyester particle dispersion to the aqueous medium either during or after the formation of the associated particles, and further aggregating the polyester particles in the aqueous polyester particle dispersion into the associated particles And growing the associated particles, and fusing and integrating the vinyl resin particles and the polyester particles in the associated particles to form toner base particles, Provided is a toner production method using the above-described aqueous polyester particle dispersion according to the present invention as a polyester particle dispersion. .

 According to the present invention, it is possible to supply a water-based polyester particle dispersion having aggregation stability, and to form toner base particles capable of suppressing the generation of fine powder and coarse powder with a narrow particle size distribution of the toner base particles to be generated. A method for producing a toner that can be produced can be provided.

1 is a diagram schematically illustrating an example of the configuration of an image forming apparatus in which toner according to an embodiment of the present invention is used.

Embodiments of the present invention will be described below.
The water-based polyester particle dispersion according to the present embodiment includes water, an anionic surfactant having two or more sulfonic acid groups and an aromatic ring site (hereinafter referred to as “polyvalent sulfonate surfactant” (PSS)). And polyester particles). In the present embodiment, the “sulfonic acid group” may be in the form of a sulfonate.

  The polyester of the polyester particles may be one kind or more. The polyester may be a crystalline polyester having crystallinity, an amorphous polyester having no crystallinity, or both of them. The polyester may be a hybrid polyester modified with an addition polymer segment of a vinyl monomer as necessary.

  The above “crystallinity” means that in differential scanning calorimetry (DSC), it has a clear endothermic peak, not a step-like endothermic change, and specifically, measured at a heating rate of 10 ° C./min. It means that the half-value width of the endothermic peak is less than 15 ° C.

  Moreover, it is preferable that the said polyester does not have a sulfonic acid group. The reason why it is better that the polyester does not have a sulfonic acid group is that the polyester has a structure of a product obtained by polycondensation reaction between a polycarboxylic acid or a derivative thereof and a polyhydric alcohol or a derivative thereof. . More specifically, the polyester has a carboxylic acid or a hydroxyl group at its terminal, and the condensation part has an ester group. For this reason, the above-mentioned polyester is inherently easy to incorporate moisture in the air to some extent. When the polyester further has a sulfonic acid group, the polyester is more likely to take in moisture in the air, and as a result, there is a concern that the fluctuation range of charging performance or the like depending on the use environment of the toner becomes large.

  “No sulfonic acid group” means that the polyester has substantially no sulfonic acid group. For example, the above polyester means that at least the molecular structure of the polyester does not contain a sulfonic acid group. However, if the amount is less than the amount that substantially acts as a sulfonic acid group, such as a polyester in which a sulfonic acid group is unintentionally introduced, for example, a polyester in which a small amount of sulfonic acid group is mixed as an impurity, the polyester is It may have a sulfonic acid group.

  The polyester has a product structure obtained by polycondensation reaction between a polycarboxylic acid or a derivative thereof and a polyhydric alcohol or a derivative thereof, and can be produced by the polycondensation reaction. In the polycondensation reaction, a known polymerization catalyst can be used as necessary. Examples of the polyvalent carboxylic acid derivatives include alkyl esters, acid anhydrides, and acid chlorides of polyvalent carboxylic acids. Examples of the polyhydric alcohol derivatives include ester compounds of polyhydric alcohols and hydroxy compounds. Carboxylic acid is included.

  The polyvalent carboxylic acid is a compound containing two or more carboxyl groups in one molecule. Examples of divalent carboxylic acids having two carboxyl groups include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, β-methyladipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, nonane Dicarboxylic acid, decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid fumaric acid, Citraconic acid, diglycolic acid, cyclohexane-3,5-diene-1,2-dicarboxylic acid, malic acid, citric acid, hexahydroterephthalic acid, tartaric acid, mucous acid, phthalic acid, maleic acid, isophthalic acid, terephthalic acid , Tetrachlorophthalic acid, chlorophthalic acid, nitrophthalic acid, -Carboxyphenylacetic acid, p-phenylenediacetic acid, m-phenylenediglycolic acid, p-phenylenediglycolic acid, o-phenylenediglycolic acid, diphenylacetic acid, diphenyl-p, p'-dicarboxylic acid, naphthalene-1,4 -Dicarboxylic acid, naphthalene-1,5-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, anthracene dicarboxylic acid, dodecenyl succinic acid, etc. are mentioned.

  Examples of the polyvalent carboxylic acid having 3 or more carboxyl groups include trimellitic acid, pyromellitic acid, naphthalenetricarboxylic acid, naphthalenetetracarboxylic acid, pyrenetricarboxylic acid and pyrenetetracarboxylic.

  A polyhydric alcohol is a compound containing two or more hydroxyl groups in one molecule. Examples of the divalent polyol (diol) having two hydroxyl groups include ethylene glycol, propylene glycol, butanediol, pentanediol, heptanediol, hexanediol, octanediol, diethylene glycol, cyclohexanediol, octanediol, nonanediol, Examples include decanediol, undecanediol, dodecanediol, tridecanediol, tetradecanediol, octadecanediol, eicosanediol, ethylene oxide adduct of bisphenol A, and propylene oxide adduct of bisphenol A.

  Examples of the polyhydric alcohol (polyol) having 3 or more hydroxyl groups include glycerin, pentaerythritol, hexamethylol melamine, hexaethylol melamine, tetramethylol benzoguanamine and tetraethylol benzoguanamine.

  The melting point Tm of the crystalline polyester is preferably 65 to 90 ° C., and 70 to 80 ° C. from the viewpoint of sufficiently expressing both the low temperature fixability and the high temperature storage property of the toner containing the crystalline polyester as a material. It is more preferable that The said melting | fusing point can be measured by DSC, and can be made into the temperature of the top of the endothermic peak in the 2nd temperature rising process in the measurement program containing the 2 temperature rising process and the cooling process in the meantime.

  The weight average molecular weight Mw of the crystalline polyester is preferably 3000 to 50000, and preferably 5000 to 40000 from the viewpoint of sufficiently exhibiting both the fixing separation property and the low-temperature fixing property of the toner containing the polyester as a material. It is more preferable. The Mw can be obtained from a measurement result of gel permeation chromatography (GPC) using styrene as a standard sample, using a calibration curve.

  Moreover, the said polyester may contain the branched structure, the crosslinked structure, etc. in some molecular structures.

  The volume average particle diameter of the polyester particles is preferably 50 to 500 nm, and more preferably 70 to 400 nm, from the viewpoint of use as a material for toner base particles. From the same viewpoint, the content of the polyester particles in the aqueous polyester particle dispersion is preferably 15 to 50% by mass, and more preferably 18 to 45% by mass.

  One or more of the polyvalent sulfonate surfactants may be used. The number of sulfonic acid groups in the polyvalent sulfonate surfactant is usually 2, but may be more. Further, the number of aromatic ring sites in the polyvalent sulfonate surfactant may be one or more, but may be more. Examples of the aromatic ring moiety include a phenyl group and a phenylene group.

  The polyvalent sulfonate surfactant is represented by the following formula, for example. In the following formula, R represents an alkyl group having 6 to 14 carbon atoms, X is independently a monovalent metal ion (for example, Na, K, Li, etc.) or an ammonium ion, or a divalent metal ion (for example, Ca Etc.). The range with more preferable carbon number of the said alkyl group R is 10-14.

  Examples of the polyvalent sulfonate surfactant include decyl diphenyl ether disulfonate sodium salt, dodecyl diphenyl ether disulfonate sodium salt, and tetradecyl diphenyl ether disulfonate sodium salt. Of these, sodium dodecyl diphenyl ether disulfonate is more preferable.

  The content of the polyvalent sulfonate surfactant in the aqueous polyester particle dispersion is 2 to 20% by mass with respect to the polyester. If the content is too small, particles having an unintended size such as fine powder or coarse powder may be generated when used as a material for toner base particles. When the content is too large, the polyvalent sulfonate surfactant is likely to remain inside the toner base particles. For example, the toner base particle dispersion described later is dehydrated, washed, and dried to obtain a toner base. In the process of obtaining the particles, removal of the polyvalent sulfonate surfactant requires a lot of energy and time, and the productivity may be significantly impaired.

  The content is 2 to 25% by mass from the viewpoint of generating toner base particles having a desired particle size when used as a material for toner base particles and suppressing generation of fine powder and coarse powder. Is preferable, and it is more preferable that it is 4-20 mass%. The content of the polyvalent sulfonate surfactant is determined by extracting the polyvalent sulfonate surfactant from the aqueous polyester particle dispersion or a dried product thereof, and coloring the resulting test solution with methylene blue. And can be determined from the absorbance of the test solution.

  The aqueous polyester particle dispersion has a pH of 7-10. Since the isoelectric point of a general carboxyl group containing polyester (the dissociation / non-dissociation ratio of all carboxyl groups is in equilibrium at about 50%) is 5 to 6 in terms of pH, it is thus neutral. Alternatively, in the alkaline aqueous polyester particle dispersion, the carboxyl group in the polyester is dissociated in water. Therefore, the polyester itself having such a carboxylate group exhibits a self-emulsifying and dispersing action, and the polyester particles can be stably dispersed over a long period of time in the aqueous polyester particle dispersion.

  If the pH is too low, the self-emulsifying and dispersing action due to the dissociation of the carboxyl groups of the polyester particles themselves is weakened. Therefore, more of the above-mentioned many more to compensate for the decrease in the stability of the particles during long-term storage of the aqueous polyester particle dispersion. The addition of a polyvalent sulfonate type surfactant is required. Therefore, when the aqueous polyester particle dispersion is used as a material for toner base particles, generation of fine powder may be insufficiently suppressed. When the pH is too high, the polyester particles themselves are in an alkali-excess state with respect to the carboxyl group, so that a so-called alkali thickening that forms a hydrogen bond between the dissociated carboxyl group and water occurs, and the above during storage Part of the particles undergoes reaggregation, and the agglomeration property of the aqueous polyester particle dispersion increases. For this reason, when the aqueous polyester particle dispersion is used as a material for toner base particles, the suppression of the occurrence of coarse powder may be insufficient.

  From the viewpoint of sufficiently expressing the aggregation stability of the aqueous polyester particle dispersion, the pH is preferably 7 to 10, and more preferably 7.3 to 9.5.

  The pH can usually be adjusted by adding a basic compound. The basic compound may be one kind or more, and examples thereof include sodium hydroxide, potassium hydroxide, ammonia and triethylamine. The basic compound may be a weak basic compound, but is preferably a strong basic compound.

  The aqueous polyester particle dispersion may further contain other components as long as the effects of the present embodiment are exhibited. For example, the water-based polyester particle dispersion contains an anionic surfactant (polyvalent sulfonate non-aromatic surfactant) having a divalent or higher sulfonic acid group and not having an aromatic ring moiety. Furthermore, you may contain.

  Examples of the polyvalent sulfonate type non-aromatic surfactant include polyoxyethylene 1,10-decanediol disulfate sodium salt, polyoxyethylene 1,12-dodecanediol disulfate sodium salt, polyoxyethylene 1,2-dodecanediol disulfate sodium salt, polyoxyethylene dodecyl glyceryl ether disulfate sodium salt and polyoxyethylene octadecyl glyceryl ether disulfate sodium salt are included.

  In addition, as the other component, the aqueous polyester particle dispersion may be added to the aqueous medium in the range where the effects of the present embodiment are exerted (for example, a monovalent sulfonate type surfactant). Agents, sulfates, phosphates, carboxylates, etc.), nonionic surfactants and alcohols.

  The aqueous polyester particle dispersion includes a step of dissolving polyester in an organic solvent (first step), and an aqueous medium is added to the obtained polyester solution with stirring, so that droplets of the polyester solution are added to the aqueous medium. A step of producing a dispersed emulsion (second step), a step of removing the organic solvent from the emulsion (third step), and the polyvalent sulfonate type anionic surfactant for the polyester And a final pH of 7 by adding to one or more selected from the group consisting of the polyester solution, the emulsion, and the emulsion from which the organic solvent has been removed in an amount of 3 to 25% by mass. The pH of one or both of the emulsion and the emulsion from which the organic solvent has been removed is adjusted by adding a basic compound so as to be 10 to 10. A step (fifth step) adjust it, can be prepared by a process comprising.

  In the first step, the aforementioned polyester is used as the polyester. As the organic solvent, an organic solvent insoluble in the aqueous medium is used to such an extent that the polyester can be dissolved and separated. Moreover, it is preferable that the said organic solvent has a boiling point which can be distilled off from the said aqueous medium. The organic solvent may be composed of one compound or a mixed solution of two or more compounds.

  Examples of the organic solvent include ketone compounds such as methyl ethyl ketone, ester compounds such as ethyl acetate and methyl acetate, and hydrocarbon compounds such as toluene. The organic solvent may contain a highly polar solvent such as alcohol or water as necessary. The boiling point of the organic solvent ensures the solubility of the resin (on the low temperature side), does not cause hydrolysis of the ester site, and it is desirable to suppress as much as possible the thermal energy applied during solvent removal from the viewpoint of productivity, Taking them into consideration, the temperature is preferably 50 to 120 ° C. In dissolving the polyester in the organic solvent, the organic solvent may be heated.

  In the second step, the polyester solution is dispersed in the aqueous medium. As described above, when the pH of the dispersion is 7 to 10, the dispersed droplets of the polyester solution are stably present due to the emulsifying action of the polyester having a carboxyl group as a salt, thereby forming the emulsion. To do. In the second step, it is only necessary to make the flow state in the system uniform. For example, the liquid having an intended size such as an anchor type stirring blade, a pitched turbine, a slit type stirring blade, a homomixer, or a homogenizer. A known stirrer capable of producing drops is used.

  In the third step, the organic solvent in the droplets is removed from the aqueous medium from the obtained emulsion. The removal of the organic solvent can be usually performed by distillation, and is preferably performed by vacuum concentration from the viewpoint of suppressing heating of the aqueous medium. In addition, the organic solvent can be removed by adding a poor solvent to the aqueous medium to the emulsion.

  In the fourth step, the polyvalent sulfonate surfactant is added to one or more selected from the group consisting of the polyester solution, the emulsion, and the emulsion from which the organic solvent has been removed. The polyvalent sulfonate surfactant can be added any number of times as long as the polyvalent sulfonate surfactant is present in the aqueous polyester particle dispersion in the desired amount. It is. From the viewpoint of efficiently introducing the polyvalent sulfonate surfactant into the surface of the polyester particles, the polyvalent sulfonate surfactant is added to the aqueous medium after the third step. It is preferable.

  In the fifth step, the pH of one or both of the emulsion and the emulsion from which the organic solvent has been removed is adjusted by adding the basic compound so that the final pH is 7 to 10. The addition of the basic compound can be performed any number of times at any time within the range of the desired final pH, that is, the desired pH of the aqueous polyester particle dispersion. From the viewpoint of enhancing the dispersibility of the polyester particles, the basic compound is preferably added to one or both of the aqueous medium and the emulsion at least once in the second step or the third step.

  The method for producing the aqueous polyester particle dispersion may further include other steps than the above steps as long as the effects of the present embodiment can be obtained.

  A conventional aqueous polyester particle dispersion having only a carboxy group terminal in an aqueous medium may have insufficient high-temperature stability during storage, and is produced when used as a material for toner base particles. Control of the intended particle size in particle growth may be insufficient.

  In contrast, the aqueous polyester particle dispersion according to the present embodiment is excellent in storage stability. In the aqueous polyester particle dispersion, the polyvalent sulfonate surfactant includes, for example, a sulfonic acid group whose one sulfonic acid group is mutually neutralized with the neutralized carboxyl group of the polyester, such as van der Waals force or hydrogen bond. It is presumed that they are bonded by action and the other sulfonic acid group is directed outward. Alternatively, the polyvalent sulfonate surfactant has, for example, an aromatic ring portion bonded to the phenylene group in the skeleton of the crystalline polyester by the interaction as described above, and sulfonic acid groups at both ends are bonded. It is presumed that it is turning outward.

  The presence of the polyvalent sulfonate surfactant in the aqueous polyester particle dispersion further enhances the electrostatic repulsion between the polyester particles. As a result, the aqueous polyester particle dispersion is Has sufficient storage stability.

  As is clear from the above description, the aqueous polyester particle dispersion contains water, the polyvalent sulfonate surfactant, and the polyester particles, and the polyvalent sulfonate surfactant. Since the content of the agent with respect to the polyester is 3 to 25% by mass and the pH is 7 to 10, the composition has excellent aggregation stability.

  Moreover, since the manufacturing method of the said aqueous | water-based polyester particle dispersion includes the said 1st-5th process, it can supply the aqueous | water-based polyester particle dispersion which has the outstanding aggregation stability.

  In the aqueous polyester particle dispersion and the method for producing the same, the polyester is one or both of a crystalline polyester having no sulfonic acid group and an amorphous polyester having no sulfonic acid group. This is more effective from the viewpoint of enhancing one or both of the low-temperature fixability and high-temperature stability of the toner base particles produced when used in the above materials.

  In the aqueous polyester particle dispersion and the method for producing the same, the volume average particle size of the polyester particles is 50 to 500 nm from the viewpoint of generating toner base particles having a desired size and a resin composition. Even more effective.

  Further, in the aqueous polyester particle dispersion and the production method thereof, the concentration of the polyester particles of 15 to 50% by mass means that the aggregation stability of the aqueous polyester particle dispersion is maintained and the toner base particles From the viewpoint that it can be used as it is, it is more effective.

  The aqueous polyester particle dispersion is suitable as a material for toner base particles, and is preferably used in a toner production method. The toner production method includes a step I in which particles of vinyl resin having at least a sulfonic acid group are aggregated in an aqueous medium in the presence of an aggregating agent to generate associated particles, and during and after the generation of the associated particles. Step II of adding an aqueous polyester particle dispersion to the aqueous medium in one or both of the above, and further aggregating the polyester particles in the aqueous polyester particle dispersion into the associated particles to grow the associated particles; and And a step III of generating toner base particles by fusing and integrating the vinyl resin particles and the polyester particles in the associated particles.

  In the step I, the vinyl resin may be one kind or more. The vinyl resin is a resin having a structure of a monomer addition polymer containing a compound having a vinyl group or a derivative thereof. The vinyl-based resin generally has substantially no crystallinity, and includes, for example, an amorphous part in the resin. A part of the vinyl resin may be modified. The vinyl resin can be obtained, for example, by a known synthesis method.

  Examples of the vinyl resin include a styrene acrylic copolymer having an addition polymer structure of a styrene monomer and an acrylic acid monomer. One or more styrenic monomers may be used. Examples thereof include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, p-ethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn -Dodecylstyrene, 2,4-dimethylstyrene and 3,4-dichlorostyrene are included.

  One or more acrylic acid monomers may be used. Examples thereof include acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, and acrylic acid. Phenyl, methyl methacrylate, ethyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, propyl γ-aminoacrylate, stearyl methacrylate, dimethylaminoethyl methacrylate and methacrylic acid Diethylaminoethyl acid is included.

  In the presence of an arbitrary polymerization initiator such as peroxide, persulfide, azo compound or the like usually used for polymerization of the monomer, the vinyl resin is bulk polymerization, solution polymerization, emulsion polymerization method, miniemulsion method, It can be obtained by performing polymerization by a known polymerization method such as suspension polymerization method or dispersion polymerization method. In the above polymerization, a chain transfer agent that is usually used can be used for the purpose of adjusting the molecular weight of the vinyl resin. Examples of chain transfer agents include alkyl mercaptans and mercapto fatty acid esters.

  The vinyl resin particles have a sulfonic acid group. The vinyl resin may have the sulfonic acid group, the vinyl resin particles may have, or both. The vinyl resin having a sulfonic acid group is, for example, a vinyl resin obtained by radical addition polymerization of a vinyl monomer in the presence of a persulfate polymerization initiator. Such vinyl resins are usually introduced with sulfonic acid groups at their ends. Examples of the persulfate-based polymerization initiator include ammonium persulfate, sodium persulfate, and potassium persulfate.

  The vinyl resin particles having a sulfonic acid group are, for example, resin particles in the presence of a sulfonate-type surfactant from oil droplets in an aqueous medium of a vinyl resin, as in the above-described aqueous polyester particle dispersion. Is obtained. The particles usually have sulfonic acid groups on the surface.

  The volume average particle diameter of the vinyl resin particles is preferably 100 to 800 nm, and preferably 150 to 600 nm from the viewpoint of achieving the desired composition of the toner base particles and achieving the desired productivity. It is more preferable.

  The concentration of the vinyl resin particles in the aqueous medium is 10 to 50% by mass from the viewpoint of developing low-temperature fixability, from the viewpoint of productivity, and from the viewpoint of sufficiently expressing the effect of the vinyl resin in the toner. It is preferably 15 to 45% by mass, more preferably 20 to 40% by mass.

  One or more flocculants may be used. The aggregating agent can be appropriately selected within the range usually used for agglomeration of the vinyl resin particles. Examples thereof include monovalent metal salts such as sodium chloride, potassium chloride and lithium chloride, calcium chloride. Divalent metal salts such as zinc chloride, copper sulfate, magnesium sulfate, manganese sulfate, calcium nitrate, barium chloride, magnesium chloride, trivalent metal salts such as aluminum chloride, iron chloride, aluminum sulfate, and polyaluminum chloride And inorganic metal salt polymers such as polyaluminum hydroxide and calcium polysulfide.

  The association particles are particles formed by integrally integrating resin particles such as the vinyl resin, and are, for example, aggregates of the resin particles. The size of the associated particles can be appropriately determined according to the desired size of the toner base particles, the production process after the formation of the associated particles, and the like.

  In the step II, the aqueous polyester particle dispersion according to the present embodiment described above, that is, the aqueous polyester particle dispersion having a pH of 7 to 10 may be used as it is as the aqueous polyester particle dispersion. The aqueous polyester particle dispersion liquid further adjusted to a pH outside the above range (for example, pH 2 to 6) may be used for the purpose of adjusting fixing performance and the like. The readjustment of the pH can be performed by a conventional method, for example, by adding the basic compound, a known acidic compound, a known salt, or a mixture thereof.

  In Step II, the aqueous polyester particle dispersion may be added to the dispersion obtained in Step I at once, or may be added in several portions. In the step II, the flocculant may be further added. In the step II, the growth of the associated particles can be performed in the same manner as the generation and growth of the associated particles in the step I, and may be performed under the same conditions or different conditions.

  In step III, fusion and integration of the associated particles can be performed by heating the dispersion. The end point of the fusion and integration can be appropriately determined according to the average circularity of the generated particles (toner base particles), for example, as usual.

  In Steps I and II, particles containing other materials of the toner base particles may be further added to the aqueous medium according to the desired amount of the other materials in the toner base particles. Examples of the other materials include a colorant, a release agent, and a charge control agent. These other materials may be contained in one or both of the vinyl resin particles and the polyester particles as long as the effects of the present embodiment can be obtained.

  One or more colorants may be used. Examples of the colorant include carbon black, a magnetic material, a dye, and a pigment. The size of the colorant particles is preferably about 10 to 200 nm.

  Examples of the carbon black include channel black, furnace black, acetylene black, thermal black and lamp black.

  Examples of the magnetic body include ferromagnetic metals such as iron, nickel, and cobalt, alloys containing these metals, and compounds of ferromagnetic metals such as ferrite and magnetite.

  Examples of the dye include C.I. I. Solvent Red 1, 49, 52, 58, 63, 111, 122, C.I. I. Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162, C.I. I. Solvent Blue 25, 36, 60, 70, 93 and 95 are included.

  Examples of the pigment include C.I. I. Pigment Red 5, 48: 1, 48: 3, 53: 1, 57: 1, 81: 4, 122, 139, 144, 149, 166, 177, 178, 222, C.I. I. Pigment Orange 31 and 43, C.I. I. Pigment Yellow 14, 17, 74, 93, 94, 138, 155, 180, 185, C.I. I. Pigment green 7, C.I. I. Pigment Blue 15: 3, 15: 4, and 60.

  One or more release agents may be used. The addition amount of the release agent is preferably 2 to 20% by mass, more preferably 3 to 18% by mass, and 4 to 15% by mass with respect to the total mass of the resin particles. Further preferred. In addition, the melting point of the release agent is preferably 50 to 95 ° C. from the viewpoint of low-temperature fixability and releasability of the toner in electrophotography.

  Examples of the release agent include hydrocarbon waxes such as low molecular weight polyethylene wax, low molecular weight polypropylene wax, Fischer-Tropsch wax, microcrystalline wax, and paraffin wax, and carnauba wax, pentaerythritol behenic acid ester, behenic acid. Ester waxes such as behenyl and behenyl citrate.

  One or more charge control agents may be used. The charge control agent is preferably dispersible in the aqueous medium, and more specifically, the number average particle diameter in the aqueous medium is preferably about 10 to 500 nm in terms of primary particle diameter.

  Examples of the charge control agent include nigrosine dyes, metal salts such as naphthenic acid and higher fatty acids, alkoxylated amines, quaternary ammonium salt compounds, azo metal complexes, and salicylic acid metal salts and metal complexes thereof. included.

  Further, the growth of the associated particles in the above production method is stopped by a conventional method, for example, by adding a metal salt having a valence different from that of the flocculant or by adding a surfactant. Can do. Steps II and III may further include the step of stopping the associated particles as necessary.

  Furthermore, the manufacturing method may further include other steps as long as the effects of the present embodiment can be obtained. Examples of the other steps include a step of further adjusting the pH of the aqueous polyester particle dispersion before being added to the aqueous medium, and mixing and adhering an external additive to the obtained toner base particles. And a step of mixing the obtained toner particles with carrier particles to obtain a toner as a two-component developer.

  If the toner is a one-component developer, the toner is composed of the toner particles themselves, and if the toner is a two-component developer, the toner is composed of the toner particles and carrier particles. The toner particle content (toner concentration) in the two-component developer may be the same as that of a normal two-component developer, and is, for example, 4.0 to 8.0% by mass.

  The toner particles include, for example, the toner base particles and an external additive present on the surface thereof. It is preferable that the toner particles contain an external additive from the viewpoint of controlling the fluidity and chargeability of the toner particles. One or more external additives may be used. Examples of the external additive include silica particles, titania particles, alumina particles, zirconia particles, zinc oxide particles, chromium oxide particles, cerium oxide particles, antimony oxide particles, tungsten oxide particles, tin oxide particles, tellurium oxide particles, oxidation Manganese particles and boron oxide particles are included.

  More preferably, the external additive includes silica particles produced by a sol-gel method. Silica particles produced by the sol-gel method have a feature that the particle size distribution is narrow, which is preferable from the viewpoint of suppressing variation in adhesion strength of the external additive to the toner base particles.

  The number average primary particle size of the silica particles is preferably 70 to 200 nm. Silica particles having a number average primary particle size in the above range are larger than other external additives. Therefore, it has a role as a spacer in the two-component developer. Therefore, it is preferable from the viewpoint of preventing other smaller external additives from being embedded in the toner base particles when the two-component developer is stirred in the developing device. Further, it is also preferable from the viewpoint of preventing fusion between the toner base particles.

  The number average primary particle diameter of the external additive can be determined by, for example, image processing of an image taken with a transmission electron microscope, and can be adjusted by classification or mixing of classified products, for example. .

  The surface of the external additive is preferably hydrophobized. A known surface treating agent is used for the hydrophobic treatment. The surface treatment agent may be one or more, and examples thereof include silane coupling agents, silicone oils, titanate coupling agents, aluminate coupling agents, fatty acids, fatty acid metal salts, esterified products thereof, and rosin. Contains acid.

  Examples of the silane coupling agent include dimethyldimethoxysilane, hexamethyldisilazane (HMDS), methyltrimethoxysilane, isobutyltrimethoxysilane, and decyltrimethoxysilane. Examples of the silicone oil include cyclic compounds, linear or branched organosiloxanes, and more specifically, organosiloxane oligomers, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, tetramethyl. Cyclotetrasiloxane and tetravinyltetramethylcyclotetrasiloxane are included.

  Examples of the silicone oil include a highly reactive silicone oil in which a modifying group is introduced into a side chain or one end or both ends, side chain piece end, side chain both ends, etc., and at least the end is modified. . The type of the modifying group may be one or more, and examples thereof include alkoxy, carboxyl, carbinol, organic groups derived from higher fatty acids, phenol, epoxy, methacryl and amino.

  The addition amount of the external additive is preferably 0.1 to 10.0% by mass with respect to the whole toner particles. More preferably, it is 1.0-3.0 mass%.

  The carrier particles are made of a magnetic material. Examples of the carrier particles include coated carrier particles having core material particles made of the magnetic material and a coating material layer covering the surface thereof, and fine powder of the magnetic material dispersed in a resin. Resin dispersed carrier particles. The carrier particles are preferably the coated carrier particles from the viewpoint of suppressing the adhesion of the carrier particles to the photoreceptor.

  The core particle is composed of a magnetic material, for example, a material that is strongly magnetized in the direction by a magnetic field. The magnetic material may be one kind or more. Examples thereof include metals exhibiting ferromagnetism such as iron, nickel and cobalt, alloys or compounds containing these metals, and alloys exhibiting ferromagnetism by heat treatment. , Is included.

Examples of the metal exhibiting ferromagnetism or a compound containing the same include iron, ferrite represented by the following formula (a), and magnetite represented by the following formula (b). M in the formulas (a) and (b) represents one or more monovalent or divalent metals selected from the group consisting of Mn, Fe, Ni, Co, Cu, Mg, Zn, Cd, and Li.
Formula (a): MO · Fe ₂ O ₃
Formula (b): MFe ₂ O ₄

  Examples of alloys or metal oxides that exhibit ferromagnetism upon heat treatment include Heusler alloys such as manganese-copper-aluminum and manganese-copper-tin, and chromium dioxide.

  The core particle is preferably the ferrite. This is because the specific gravity of the coated carrier particles is smaller than the specific gravity of the metal constituting the core material particles, so that the impact force of stirring in the developing device can be further reduced.

  The said coating | covering material may be 1 type, or more. As the coating material, a known resin used for coating the core particles of the carrier particles can be used. It is preferable that the coating material is a resin having a cycloalkyl group from the viewpoint of reducing the moisture adsorptivity of the carrier particles and increasing the adhesion between the coating material layer and the core material particles. Examples of the cycloalkyl group include a cyclohexyl group, a cyclopentyl group, a cyclopropyl group, a cyclobutyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, and a cyclodecyl group. Among them, a cyclohexyl group or a cyclopentyl group is preferable, and a cyclohexyl group is more preferable from the viewpoint of adhesion between the coating material layer and the ferrite particles.

The weight average molecular weight Mw of the resin having a cycloalkyl group is, for example, 10,000 to 800,000, and more preferably 100,000 to 750000. Content of the said cycloalkyl group in the said resin is 10-90 mass%, for example. The content of the cycloalkyl group in the resin can be determined using a known instrumental analysis method such as P-GC / MS or ¹ H-NMR.

  The two-component developer can be produced by mixing an appropriate amount of the toner particles and the carrier particles. Examples of the mixing apparatus used for the mixing include a Nauter mixer, a W cone, and a V-type mixer.

  The size and shape of the toner particles can be appropriately determined as long as the effects of the present embodiment can be obtained. For example, the volume average particle size of the toner particles is 3.0 to 8.0 μm, and the average circularity of the toner particles is 0.920 to 1.000.

  The number average particle diameter of the toner particles can be measured and calculated using an apparatus in which a computer system for data processing is connected to “Multisizer 3” (manufactured by Beckman Coulter, Inc.). Further, the number average particle diameter of the toner particles can be adjusted by, for example, temperature and stirring conditions in the production of toner particles, classification of toner particles, and mixing of classified toner particles.

The average circularity of the toner particles is determined by using, for example, a flow type particle image analyzer “FPIA-3000” (manufactured by Sysmex), and a perimeter length L1 of a circle having the same projected area as the particle image in a predetermined number of toner particles. And the peripheral length L2 of the projected particle image, the total circularity C calculated from the following equation is divided by the predetermined number. The average circularity of the toner particles can be adjusted, for example, by the degree of aging of the resin particles in the production of the toner particles, heat treatment of the toner particles, mixing of toner particles having different circularity, and the like.
(Formula) C = L1 / L2

  Further, the size and shape of the carrier particles can be appropriately determined within a range in which the effect of the present embodiment can be obtained. For example, the carrier particles have a volume average particle size of 15 to 100 μm. The volume average particle diameter of the carrier particles can be measured by a wet method using, for example, a laser diffraction particle size distribution measuring device “HELOS KA” (manufactured by Nippon Laser Corporation). The volume average particle size of the carrier particles is adjusted by, for example, a method of controlling the particle size of the core material particles according to the manufacturing conditions of the core material particles, classification of the carrier particles, mixing of classified products of the carrier particles, or the like. Is possible.

  In the method for producing the toner, by using the aqueous polyester particle dispersion as a material for toner base particles containing the vinyl resin and the polyester as a binder resin, the vinyl resin particles and the polyester particles are used. Aggregation uniformity is increased. The reason is considered as follows.

  In general, persulfate is used as a polymerization initiator during emulsion polymerization of a styrene acrylic copolymer that is a vinyl resin. For this reason, a sulfonic acid group is introduced into the terminal of the styrene acrylic copolymer. Therefore, since sulfonic acid groups exist in addition to carboxy groups on the surface of the styrene acrylic copolymer particles in the aqueous medium, the aggregation stability of the particles is generally high.

  On the other hand, since polyester is generally obtained by polycondensation of a polyvalent carboxylic acid and a polyhydric alcohol, a carboxyl group is present at the end of the molecular structure, but a sulfonic acid group is not usually present. Therefore, since only the carboxy group is present on the surface of the polyester particles in the aqueous medium, the aggregation stability of the particles is lower than that of the styrene-acrylic copolymer particles.

  The aggregation stability of the particles can be obtained also in the aqueous polystyrene dispersion by using, for example, a monovalent sulfonate surfactant as a dispersant. However, when the aqueous polyester particle dispersion is used as a material for toner base particles together with the aqueous styrene acrylic copolymer dispersion, the above-mentioned aqueous polyester particles can be used to uniformly aggregate two types of resin particles having different cohesive properties. The cohesiveness of the polyester particles in the dispersion is insufficient. Therefore, in the above case, particles having a desired size and shape may not be formed without generating fine powder or coarse powder.

  In the present embodiment, since an anionic surfactant having a divalent sulfonic acid group and an aromatic ring is present on the surface of the polyester particles, the density of the sulfonic acid group on the surface is further increased. Therefore, in the electrostatic repulsion (repulsive force) between the resin particles and the aggregation attractive force between the aggregating agent and the resin particles, the polyester particles and the styrene acrylic copolymer particles can be balanced. A uniform hetero resin particle aggregate is formed. As a result, toner base particles having a sharp particle size distribution with little generation of fine powder and coarse powder can be obtained by using the toner base particle material.

  As is clear from the above description, the toner production method comprises the steps of aggregating particles of a vinyl resin having at least a sulfonic acid group in an aqueous medium in the presence of an aggregating agent to produce associated particles; During one or both of the generation of the associated particles and after the generation, an aqueous polyester particle dispersion is added to the aqueous medium, and the particles of the polyester in the aqueous polyester particle dispersion are further aggregated into the associated particles to form the associated particles. And a step of producing toner base particles by fusing and integrating the vinyl resin particles and the polyester particles in the associated particles, and the aqueous polyester particle dispersion described above. Is it possible to use the aqueous polyester particle dispersion liquid of this embodiment as it is or after adjusting the pH further? Can the particle size distribution of the resulting toner base particles is narrow, to produce the toner base particles capable of suppressing generation of fines and coarse powder.

  The toner production method further includes a step of further adjusting the pH of the aqueous polyester particle dispersion before being added to the aqueous medium, and further adjusting the pH of the aqueous polyester particle dispersion added to the aqueous medium. The use of the above-described aqueous polyester particle dispersion is more effective from the viewpoint of enhancing the desired properties of the obtained toner.

  When a vinyl resin obtained by radical addition polymerization of a vinyl monomer in the presence of a persulfate polymerization initiator is used for the vinyl resin having a sulfonic acid group, the sulfonic acid group is added to the vinyl resin. It is more effective from the viewpoint of easy introduction, and the fact that the vinyl resin is a styrene acrylic copolymer is more effective from the viewpoint of developing desired toner characteristics.

  As is apparent from the above description, in the present embodiment, an aqueous polyester particle dispersion having excellent storage stability can be obtained by using a surfactant having a higher sulfonic acid group density.

  An anion having a divalent sulfonic acid group and an aromatic ring in forming aggregated particles from particles of vinyl resin such as styrene acrylic copolymer having a sulfonic acid group in the molecule and polyester particles By using the polyester particles containing the surfactant, the balance of aggregation between the vinyl resin particles and the polyester particles can be controlled with high accuracy. As a result, by utilizing the aggregation, fine particles can be obtained. In addition, toner base particles with less generation of coarse powder can be obtained.

  The toner is applied to an ordinary electrophotographic image forming method and used for developing an electrostatic latent image. For example, the toner is accommodated in the image forming apparatus shown in FIG. 1 and used for forming a toner image on a recording medium.

  The image forming apparatus 1 illustrated in FIG. 1 includes an image reading unit 110, an image processing unit 30, an image forming unit 40, a paper transport unit 50, and a fixing device 60.

  The image forming unit 40 includes image forming units 41Y, 41M, 41C, and 41K that form images of toners of Y (yellow), M (magenta), C (cyan), and K (black). Since these have the same configuration except for the toner to be accommodated, the symbols representing the colors may be omitted hereinafter. The image forming unit 40 further includes an intermediate transfer unit 42 and a secondary transfer unit 43. These correspond to a transfer device.

  The image forming unit 41 includes an exposure device 411, a developing device 412, a photosensitive drum 413, a charging device 414, and a drum cleaning device 415. The photoreceptor drum 413 is, for example, a negatively charged organic photoreceptor. The surface of the photosensitive drum 413 has photoconductivity. The photoconductor drum 413 corresponds to a photoconductor. The charging device 414 is, for example, a corona charger. The charging device 414 may be a contact charging device that charges a contact charging member such as a charging roller, a charging brush, or a charging blade by contacting the photosensitive drum 413. The exposure device 411 includes, for example, a semiconductor laser as a light source, and a light deflection device (polygon motor) that irradiates the photosensitive drum 413 with laser light corresponding to an image to be formed.

  The developing device 412 is a two-component developing type developing device. The developing device 412 includes, for example, a developing container that contains a two-component developer, a developing roller (magnetic roller) that is rotatably disposed in an opening of the developing container, and a developing container that allows the two-component developer to communicate with each other. A partition partitioning the inside, a transport roller for transporting the two-component developer on the opening side of the developing container toward the developing roller, and an agitation roller for stirring the two-component developer in the developing container . The developer container contains the toner as a two-component developer.

  The intermediate transfer unit 42 includes an intermediate transfer belt 421, a primary transfer roller 422 that presses the intermediate transfer belt 421 against the photosensitive drum 413, a plurality of support rollers 423 including a backup roller 423A, and a belt cleaning device 426. The intermediate transfer belt 421 is looped around the plurality of support rollers 423. When at least one drive roller of the plurality of support rollers 423 rotates, the intermediate transfer belt 421 travels at a constant speed in the arrow A direction.

  The secondary transfer unit 43 has a plurality of support rollers 431 including an endless secondary transfer belt 432 and a secondary transfer roller 431A. The secondary transfer belt 432 is stretched in a loop by the secondary transfer roller 431A and the support roller 431.

  The fixing device 60 fixes, for example, the fixing roller 62, an endless heating belt 63 that covers the outer peripheral surface of the fixing roller 62, and heats and melts the toner constituting the toner image on the paper S, and the paper S. And a pressure roller 64 that presses toward the roller 62 and the heat generating belt 63. The paper S corresponds to a recording medium.

  The image forming apparatus 1 further includes an image reading unit 110, an image processing unit 30, and a paper transport unit 50. The image reading unit 110 includes a paper feeding device 111 and a scanner 112. The paper transport unit 50 includes a paper feed unit 51, a paper discharge unit 52, and a transport path unit 53. In the three paper feed tray units 51 a to 51 c constituting the paper feed unit 51, paper S (standard paper, special paper) identified based on basis weight, size, or the like is accommodated for each preset type. . The conveyance path unit 53 includes a plurality of conveyance roller pairs such as registration roller pairs 53a.

Image formation by the image forming apparatus 1 will be described.
The scanner 112 optically scans and reads the document D on the contact glass. Reflected light from the document D is read by the CCD sensor 112a and becomes input image data. The input image data is subjected to predetermined image processing in the image processing unit 30 and sent to the exposure device 411.

  The photosensitive drum 413 rotates at a constant peripheral speed. The charging device 414 uniformly charges the surface of the photosensitive drum 413 to a negative polarity. In the exposure apparatus 411, the polygon mirror of the polygon motor rotates at high speed, and the laser light corresponding to the input image data of each color component is developed along the axial direction of the photosensitive drum 413, and the photosensitive member along the axial direction. The drum 413 is irradiated on the outer peripheral surface. Thus, an electrostatic latent image is formed on the surface of the photosensitive drum 413.

  In the developing device 412, the toner particles are charged by stirring and transporting the two-component developer in the developing container, and the two-component developer is transported to the developing roller, and forms a magnetic brush on the surface of the developing roller. The charged toner particles are electrostatically attached to the electrostatic latent image portion on the photosensitive drum 413 from the magnetic brush. In this way, the electrostatic latent image on the surface of the photosensitive drum 413 is visualized, and a toner image corresponding to the electrostatic latent image is formed on the surface of the photosensitive drum 413.

  The toner image on the surface of the photosensitive drum 413 is transferred to the intermediate transfer belt 421 by the intermediate transfer unit 42. Transfer residual toner remaining on the surface of the photosensitive drum 413 after the transfer is removed by a drum cleaning device 415 having a drum cleaning blade that is in sliding contact with the surface of the photosensitive drum 413.

  When the intermediate transfer belt 421 is pressed against the photosensitive drum 413 by the primary transfer roller 422, a primary transfer nip is formed for each photosensitive drum 413 by the photosensitive drum 413 and the intermediate transfer belt 421. In the primary transfer nip, the toner images of the respective colors are sequentially transferred onto the intermediate transfer belt 421.

  On the other hand, the secondary transfer roller 431A is pressed against the backup roller 423A via the intermediate transfer belt 421 and the secondary transfer belt 432. Accordingly, a secondary transfer nip is formed by the intermediate transfer belt 421 and the secondary transfer belt 432. The sheet S passes through the secondary transfer nip. The sheet S is conveyed to the secondary transfer nip by the sheet conveying unit 50. The correction of the inclination of the sheet S and the adjustment of the conveyance timing are performed by a registration roller unit provided with a registration roller pair 53a.

  When the sheet S is conveyed to the secondary transfer nip, a transfer bias is applied to the secondary transfer roller 431A. By applying the transfer bias, the toner image carried on the intermediate transfer belt 421 is transferred onto the paper S. The sheet S on which the toner image is transferred is conveyed toward the fixing device 60 by the secondary transfer belt 432.

  The fixing device 60 forms a fixing nip by the heat generating belt 63 and the pressure roller 64, and heats and presses the conveyed paper S at the fixing nip portion. The toner particles constituting the toner image on the paper S are heated, and the polyester (for example, crystalline polyester) melts quickly in the inside thereof. As a result, the entire toner particles melt quickly with a relatively small amount of heat, and the toner component Adheres to the paper S. In the adhered molten toner component, the polyester is also quickly crystallized, and the entire molten toner component is rapidly solidified. Thus, the toner image is quickly fixed on the paper S with a relatively small amount of heat. The paper S on which the toner image has been fixed is discharged out of the apparatus by a paper discharge unit 52 having a paper discharge roller 52a. Thus, a high-quality image is formed.

  Note that transfer residual toner remaining on the surface of the intermediate transfer belt 421 after the secondary transfer is removed by a belt cleaning device 426 having a belt cleaning blade that is in sliding contact with the surface of the intermediate transfer belt 421.

  In the toner, since the aggregation characteristics of the polyester particles are similar to those of the vinyl resin, the polyester is easily included in the vinyl resin in the toner base particles. Therefore, since the polyester is difficult to be exposed from the toner base particles, the compatibility between the polyester and the vinyl resin is suppressed even if the polyester is exposed to a relatively high temperature environment during storage. Therefore, the toner has sufficient low-temperature stability as described above and sufficient high-temperature storage properties.

  The present invention will be described more specifically with reference to the following examples and comparative examples. In addition, this invention is not limited to a following example.

[Production of polyester C1]
In a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, the following components were added in the following amounts, and the inside of the reaction vessel was replaced with dry nitrogen gas, followed by 0.1 mass of titanium tetrabutoxide Further, a polymerization reaction was carried out for 8 hours while stirring at 180 ° C. under a nitrogen gas stream.
1,9-nonanediol 252 parts by mass 1,10-decanedicarboxylic acid 315 parts by mass

  To the obtained reaction liquid, 0.2 parts by mass of titanium tetrabutoxide was further added, and the temperature of the reaction liquid was increased to 220 ° C., and the polymerization reaction was further performed for 6 hours while stirring. Next, the pressure in the reaction vessel was reduced to 10 kPa, and the reaction was further performed at the above temperature under reduced pressure for 1 hour to obtain polyester C1 which is a crystalline polyester. The weight average molecular weight Mw of the polyester C1 was 14,000.

  The Mw of polyester C1 was determined by gel permeation chromatography. More specifically, as a GPC apparatus, an HLC-8120GPC, SC-8020 apparatus manufactured by Tosoh Corporation is used, TSKgei, SuperHM-H (6.0 mm ID × 15 cm × 2) is used as a column, and Wako Pure Chemical Industries is used as an eluent. This was carried out using THF (tetrahydrofuran) for chromatography. As the experimental conditions, the experiment was performed using a sample concentration of 0.5%, a flow rate of 0.6 mL / min, a sample injection amount of 10 μL, a measurement temperature of 40 ° C., and an IR detector. The calibration curve is “polystylen standard sample TSK standard” manufactured by Tosoh Corporation: A-500, F-1, F-10, F-80, F-380, A-2500, F-4, F-40, It produced from 10 samples of F-128 and F-700. The data collection interval in sample analysis was 300 ms.

The melting point Tm of the polyester C1 was 72 ° C. The melting point Tm of the polyester C1 is determined by differential scanning calorimetry (DSC), 3.0 mg of the polyester C1 is enclosed in an aluminum pan, and the endothermic peak peak in the DSC curve during the second heating step in the following temperature program Temperature.
[Temperature program]
First temperature raising step: step of raising the temperature of the sample from room temperature (25 ° C.) to 150 ° C. at 10 ° C./min and maintaining 150 ° C. for 5 minutes Cooling step: temperature of the sample following the first temperature raising step The temperature is lowered from 150 ° C. to 0 ° C. at 10 ° C./min and maintained at 0 ° C. for 5 minutes. Second temperature raising step: Following the cooling step, the temperature of the sample is raised from 0 ° C. to 150 ° C. at 10 ° C./min. Process

[Production of polyester C2]
In a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, the following components were added in the following amounts, and the inside of the reaction vessel was replaced with dry nitrogen gas, followed by 0.1 mass of titanium tetrabutoxide The polymerization reaction was carried out for 6 hours while stirring at 220 ° C. under a nitrogen gas stream. Next, the pressure in the reaction vessel was reduced to 10 kPa, and the reaction was further performed at the above temperature under reduced pressure for 1 hour. Subsequently, the obtained reaction liquid was once cooled to 160 ° C.
1,9-nonanediol 225 parts by mass 1,10-decanedicarboxylic acid 283 parts by mass

A mixed solution containing the following components in the following amounts was added dropwise to the reaction solution with a dropping funnel over 1 hour. In addition, the following “di-t-butyl peroxide” is a polymerization initiator. Subsequently, addition polymerization reaction was performed at 160 degreeC for 1 hour. Next, the temperature of the obtained reaction liquid was raised to 200 ° C. and maintained at this temperature at 10 kPa for 1 hour to remove excess styrene and butyl acrylate, thereby obtaining polyester C2 which is a crystalline vinyl-modified polyester. Mw of polyester C2 was 15,600. Moreover, Tm of polyester C2 was 70 degreeC.
Acrylic acid 5 parts by weight Styrene 42 parts by weight Butyl acrylate 11 parts by weight Di-t-butyl peroxide 7 parts by weight

[Production of polyester A1]
In a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, the following components are added in the following amounts, and the inside of the reaction vessel is replaced with dry nitrogen gas, followed by 0.2 mass of titanium tetrabutoxide. The polymerization reaction was carried out for 6 hours with stirring at 180 ° C. under a nitrogen gas stream. To the obtained reaction solution, 0.3 parts by mass of titanium tetrabutoxide was further added, the temperature of the reaction solution was raised to 200 ° C., and a polymerization reaction was performed at the temperature for 6 hours while stirring. Next, the pressure in the reaction vessel was reduced to 1.5 kPa, and the reaction was further performed at the above temperature under reduced pressure for 1 hour to obtain polyester A1 which was an amorphous polyester.
Bisphenol A propylene oxide 2 mol adduct 360 parts by mass Isophthalic acid 52 parts by mass Terephthalic acid 52 parts by mass Trimellitic acid 32 parts by mass Fumaric acid 17 parts by mass

  Mw of polyester A1 was 17,200. Polyester A1 had a glass transition point Tg of 60.5 ° C. and a softening point Tsp of 106 ° C.

  Tg is the second heat when performing the heat-cool-heat temperature control at the measurement temperature of 0 ° C. to 150 ° C., the temperature increase rate of 10 ° C./min, and the temperature decrease rate of 10 ° C./min in the DSC. Is the temperature at the intersection of the baseline extension before the first endothermic peak rises and the tangent showing the maximum slope from the first peak rise to the peak apex.

Tsp is measured by a flow tester shown below. That is, in an environment of 20 ° C. and 50% RH, 1.1 g of a sample (Polyester A1) was placed in a petri dish and flattened and allowed to stand for 12 hours or more. Then, a molding machine “SSP-10A” (manufactured by Shimadzu Corporation) Is pressed with a force of 3820 kg / cm ² (37.5 MPa) for 30 seconds to produce a cylindrical molded sample having a diameter of 1 cm. The above Tsp is obtained by subjecting this molded sample to a load tester “CFT-500D” (manufactured by Shimadzu Corporation) in an environment of 24 ° C. and 50% RH, a load of 196 N (20 kgf), a starting temperature of 60 ° C., and a preheating time of 300 seconds. Extruding from a cylindrical die hole (1 mm diameter x 1 mm) using a piston with a diameter of 1 cm from the end of preheating under the condition of a heating rate of 6 ° C / min, and an offset value of 5 mm by the melting temperature measurement method of the heating method Is the offset method temperature Toffset when measured with the setting of

[Production of polyester A2]
In a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, the following components were put in the following amounts, and the inside of the reaction vessel was replaced with dry nitrogen gas, and then titanium tetrabutoxide 0.2 A part by mass was further added, and a polymerization reaction was performed for 6 hours while stirring at 180 ° C. under a nitrogen gas stream. Subsequently, the inside of the reaction vessel was depressurized to 10 kPa, further reaction was performed at the above temperature under reduced pressure for 1 hour, and the obtained reaction liquid was once cooled to 160 ° C.
Bisphenol A propylene oxide 2 mol adduct 288 parts by mass Isophthalic acid 42 parts by mass Terephthalic acid 42 parts by mass Trimellitic acid 26 parts by mass Fumaric acid 14 parts by mass

A mixed solution containing the following components in the following amounts was added dropwise to the reaction solution with a dropping funnel over 1 hour, and after the addition, an addition polymerization reaction was performed at 160 ° C. for 1 hour. Next, the temperature of the reaction solution was raised to 200 ° C. and held at 10 kPa at that temperature for 1 hour to remove excess styrene and butyl acrylate, thereby obtaining polyester A2 which was an amorphous vinyl-modified polyester. Mw of polyester A2 was 18,900. Moreover, Tg of polyester A2 was 58.9 degreeC and Tsp was 107 degreeC.
Acrylic acid 5 parts by weight Styrene 75 parts by weight Butyl acrylate 26 parts by weight Di-t-butyl peroxide 16 parts by weight

Table 1 shows the raw material ratios of polyesters C1, C2, A1, and A2. In the table below, “PEs” represents polyester, “U _PEs ” represents a polyester unit, “U _Vr ” represents a vinyl resin unit, “Pal” represents a polyhydric alcohol component, and “Pca” represents a polyvalent carboxylic acid component. , “BPA” is a 2 mol adduct of bisphenol A propylene oxide, “NDO” is 1,9-nonanediol, “DCA” is 1,10-decanedicarboxylic acid, “IPA” is isophthalic acid, “TPA” "Represents terephthalic acid," TA "represents trimellitic acid," FA "represents fumaric acid, and" StAc "represents a styrene acrylic graft portion.

[Production of PEs dispersion L1]
After mixing 150 parts by weight of polyester C1 with 100 parts of methyl ethyl ketone, the mixture was stirred and dissolved at 70 ° C. Then, a 25% by weight aqueous sodium hydroxide solution as a neutralizing agent was added to the resulting solution with stirring. Pure water at 70 ° C. was added to the obtained dispersion to obtain a dispersion in which oil-phase polyester-containing droplets were dispersed in an aqueous medium.

  Next, methyl ethyl ketone is removed from the dispersion by vacuum concentration, and then the dispersion is cooled to 30 ° C. Then, sodium dodecyl diphenyl ether disulfonate is added to the dispersion in an amount corresponding to 3 parts by mass relative to the resin solids, A PEs dispersion L1 which is an aqueous polyester particle dispersion was obtained. It was 155 nm when the volume average particle diameter of the resin particles in the PEs dispersion L1 was measured by “Nanotrack Wave EX150” (manufactured by Nikkiso Co., Ltd.).

  Further, the pH of the PEs dispersion L1 was measured using a glass electrode type hydrogen ion concentration indicator “HM-20P” (manufactured by Toa DKK Corporation) and the reference electrode internal solution “RE-4” as a phthalic acid standard solution (pH 4. 01, 25 ° C.), neutral phosphate standard solution (pH 6.86, 25 ° C.), borate standard solution (pH 9.18, 25 ° C.), and after measuring three points, it was 8.9. there were.

  When the amount of sodium dodecyl diphenyl ether disulfonate in PEs dispersion L1 was detected from PEs dispersion L1, it was confirmed that the amount of sodium dodecyl diphenyl ether disulfonate was substantially the same as the amount added above. . The amount of sodium dodecyl diphenyl ether disulfonate in the PEs dispersion L1 was obtained by dissolving 0.1 g of the dried product of the dispersion in 50 mL of chloroform, and extracting the surfactant from the chloroform layer with 100 mL of ion-exchanged water. The chloroform layer is extracted once again with 100 mL of ion-exchanged water, a total of 200 mL of the extract (aqueous layer) is diluted to 2000 mL, and the obtained diluted solution is used as a test solution according to the method specified in JIS K0170-8. Is colored with methylene blue, the absorbance of the test solution is measured, and the amount of sodium dodecyl diphenyl ether disulfonate in the PEs dispersion L1 is calculated from a separately prepared calibration curve.

(Evaluation of storability)
The PEs dispersion L1 was mixed with a magnetic stirrer for 5 minutes, and the volume average particle diameter mV and the number average particle diameter mn were measured with Nanotrack Wave (manufactured by Nikkiso Co., Ltd.), and the distribution index I ₀ (mv / mn) was calculated. Next, the PEs dispersion L1 was allowed to stand in an environment of 50 ° C. for 1 month, then mixed with a magnetic stirrer for 5 minutes, and the distribution index I ₁ (mv / mn) after standing was determined in the same manner as I _0. Calculated. And change rate (DELTA) I (%) of the distribution index before and behind standing calculated | required by the following formula was calculated | required, and the storage property of PEs dispersion liquid L1 was evaluated for the said (DELTA) I with the following reference | standard. As a result, ΔI of PEs dispersion L1 was 7.7%.
ΔI = {| I ₀ −I ₁ | / L ₀ } × 100
[Evaluation criteria]
○: ΔI is within 5% Δ: ΔI is over 5% and within 10% ×: ΔI is over 10%

[Production of PEs dispersions L2 to L5]
Except for changing the addition amount of sodium dodecyl diphenyl ether disulfonate to the resin solid content to 9 parts by mass, 20 parts by mass, 2.9 parts by mass and 25.1 parts by mass, respectively, in the same manner as in the production of PEs dispersion L1, PEs dispersions L2 to L5 were obtained, respectively. The pH of PEs dispersion L2 was 8.5, and ΔI was 4.4%. The pH of PEs dispersion L3 was 7.5, and ΔI was 3.9%. The pH of the PEs dispersion L4 was 8.9, and ΔI was 8.5%. The pH of the PEs dispersion L5 was 7.3, and ΔI was 2.9%.

[Production of PEs dispersions L6 and L7]
PEs dispersions L6 and L7 were obtained in the same manner as in the production of PEs dispersion L2, except that polyesters C2 and A1 were used instead of polyester C1, respectively. The pH of PEs dispersion L6 was 8.3, and ΔI was 4.2%. The pH of PEs dispersion L7 was 8.7, and ΔI was 2.2%.

[Production of PEs dispersions L8 to L12]
Polyester A2 is used instead of polyester C1, and the amount of sodium dodecyl diphenyl ether disulfonate added to the resin solid content is changed to 3% by mass, 10% by mass, 20% by mass, 2.9% by mass, and 25.1% by mass, respectively. Otherwise, PEs dispersions L8 to L12 were obtained in the same manner as in the production of PEs dispersion L1. The pH of PEs dispersion L8 was 9.0, and ΔI was 5.2%. The pH of PEs dispersion L9 was 8.5, and ΔI was 4.2%. The pH of PEs dispersion L10 was 7.4, and ΔI was 2.7%. The pH of PEs dispersion L11 was 8.6, and ΔI was 6.3%. The pH of PEs dispersion L12 was 7.3, and ΔI was 2.3%.

[Production of PEs dispersions L13 and L14]
PEs dispersions L13 and L14 were obtained in the same manner as in the production of PEs dispersion L9, except that the pH was adjusted after obtaining the polyester dispersion. The pH of PEs dispersion L13 was 6.7, and ΔI was 5.4%. The pH of PEs dispersion L14 was 10.2, and ΔI was 5.3%.

[Production of PEs dispersion L15]
A PEs dispersion L15 was obtained in the same manner as the PES dispersion L9, except that polyoxyethylene (2) sodium dodecylglyceryl ether disulfate was used instead of sodium dodecyl diphenyl ether disulfonate. The pH of PEs dispersion L15 was 7.8, and ΔI was 4.7%.

[Production of PEs dispersions L16 and L17]
PEs dispersion L16 was prepared in the same manner as in the production of PEs dispersion L1 except that polyoxyethylene (2) sodium lauryl sulfate was used in place of sodium dodecyl diphenyl ether disulfonate and the addition amount thereof was 5 parts by mass relative to the resin solid content. Got. In addition, PEs dispersion L17 was obtained in the same manner as in the production of PEs resin dispersion L16 except that polyester A2 was used instead of polyester C1. The pH of PEs dispersion L16 was 7.3, and ΔI was 3.1%. The pH of PEs dispersion L17 was 7.6, and ΔI was 2.1%.

[Production of PEs dispersion L18]
A PEs dispersion L18 was obtained in the same manner as the PES dispersion L9 except that sodium dodecylbenzenesulfonate was used in place of sodium dodecyl diphenyl ether disulfonate. The pH of the PEs dispersion L18 was 7.9, and ΔI was 5.1%.

  Table 2 shows the composition, pH, ΔI, and storability of the materials of the PEs dispersions L1 to L18. In Table 2, "SS" is a sulfonate anionic surfactant, "ArPSS1" is sodium dodecyl diphenyl ether disulfonate, "AlPSS2" is polyoxyethylene (2) sodium dodecyl glyceryl ether disulfate, “AlSS3” represents sodium polyoxyethylene (2) lauryl sulfate, and “ArSS4” represents sodium dodecylbenzenesulfonate. Further, “content (parts by mass)” of SS is the part by mass of SS in the dispersion, “contents (% by mass)” is mass% of SS with respect to resin solids, and “Rv”. Is the volume average particle size of the polyester particles in the PEs dispersion.

[Preparation of VR dispersion 1]
(First stage polymerization)
8 parts by mass of sodium dodecyl sulfate and 3000 parts by mass of ion-exchanged water are charged into a 5 L reaction vessel equipped with a stirrer, a temperature sensor, a condenser, and a nitrogen introduction device, and the reaction vessel is stirred at a rate of 230 rpm under a nitrogen stream. While stirring the solution 1-1, the internal temperature of the reaction vessel was raised to 80 ° C. Next, a solution 1-2 in which 10 g of potassium persulfate was dissolved in 200 g of ion-exchanged water was added to the solution 1-1, and the temperature of the obtained solution 1-3 was set to 80 ° C.

Styrene 480 parts by mass n-butyl acrylate 250 parts by mass Methacrylic acid 68 parts by mass Next, a monomer mixture containing the above components in the above amounts was added dropwise over 1 hour to Solution 1-3, and then obtained. The monomer was polymerized by heating and stirring the mixture at 80 ° C. for 2 hours to prepare resin particle dispersion X1 in which resin particles x1 were dispersed.

(Second stage polymerization)
A solution 2-1 in which 7 parts by mass of polyoxyethylene (2) sodium dodecyl ether sulfate was dissolved in 2000 parts by mass of ion-exchanged water in a 5 L reaction vessel equipped with a stirrer, a temperature sensor, a cooling pipe, and a nitrogen introduction apparatus The mixture was charged and heated to 98 ° C., and solution 2-2 containing 260 parts by mass of resin particles x1 and the following components in the following amounts was added to solution 2-1. The following behenic acid behenate is a mold release agent, and its melting point is 73 ° C.
Styrene 284 parts by weight n-butyl acrylate 92 parts by weight Methacrylic acid 13 parts by weight n-octyl-3-mercaptopropionate 1.5 parts by weight Behenate behenate 190 parts by weight

  The resulting mixture is mixed and dispersed for 1 hour using a mechanical disperser “CREARMIX” (M Technique Co., Ltd., “CREAMIX” is a registered trademark of the company) having a circulation path, and emulsified particles (oil droplets). A dispersion 2-3 containing was prepared.

  Next, an initiator solution 2-4 in which 6 parts by mass of potassium persulfate is dissolved in 200 parts by mass of ion-exchanged water is added to the dispersion 2-3, and the resulting mixture is stirred at 84 ° C. for 1 hour. Thus, the above monomer was polymerized to prepare resin particle dispersion X2 in which resin particles x2 were dispersed.

(3rd stage polymerization)
A solution 3-1 in which 11 parts by mass of potassium persulfate was dissolved in 300 parts by mass of ion-exchanged water was added to the resin particle dispersion X2 to obtain a mixed solution. A monomer mixture containing the following components in the following amounts was dropped into the mixture at 82 ° C. over 1 hour.
Styrene 350 parts by mass n-butyl acrylate 215 parts by mass Acrylic acid 30 parts by mass n-octyl-3-mercaptopropionate 8 parts by mass

  Next, the monomer is polymerized by stirring the mixed solution at the above temperature for 2 hours, and then the mixed solution is cooled to 28 ° C. Thus, resin particles of an amorphous resin made of a vinyl resin. A VR dispersion 1 in which VR1 is dispersed was prepared.

  The volume-based median diameter of the resin particles VR1 in the VR dispersion 1 was measured and found to be 220 nm. Moreover, it was 32000 when the weight average molecular weight of resin which comprises the resin particle VR1 was measured. Furthermore, it was 55 degreeC when the glass transition temperature of the said resin was measured.

[Preparation of Cy dispersion]
90 parts by weight of sodium dodecyl sulfate was added to 1600 parts by weight of ion-exchanged water, and while stirring, 420 parts by weight of copper phthalocyanine (CI Pigment Blue 15: 3) was gradually added to the resulting solution. By carrying out a dispersion treatment using a stirrer “CLEARMIX” (manufactured by M Technique Co., Ltd.), an aqueous Cy dispersion in which particles of the colorant were dispersed was prepared. The volume-based median diameter of the colorant particles in the Cy dispersion was measured using a dynamic light scattering particle size distribution measuring device “Nanotrack Wave” (manufactured by Nikkiso Co., Ltd.), and was 120 nm.

[Production of Toner 1]
In a reaction vessel equipped with a stirrer, a temperature sensor, and a cooling pipe, 200 parts by mass of VR dispersion 1 in terms of solid content, 14 parts by mass of Cy dispersion in terms of colorant solid content, and 2000 parts by mass of ion-exchanged water Then, a 5 mol / liter aqueous sodium hydroxide solution was further added to the reaction vessel to adjust the pH of the mixed solution in the reaction vessel to 10.

  Next, an aqueous solution in which 60 parts by mass of magnesium chloride was dissolved in 60 parts by mass of ion-exchanged water was added to the above mixed solution over 10 minutes at 30 ° C. with stirring. Next, the obtained mixed liquid is heated to 80 ° C. over 90 minutes, and then 20 parts by mass of PEs dispersion L1 in terms of solid content is added to the mixed liquid over 20 minutes, and the number of stirring is appropriately set. The particle size of the associated particles was measured with “Coulter Multisizer 3” (manufactured by Coulter Beckman), and the particles were aggregated until the volume-based median diameter of the associated particles was 6.0 μm.

  Next, when the median diameter becomes 6.0 μm, an aqueous solution in which 190 parts by mass of sodium chloride is dissolved in 760 parts by mass of ion-exchanged water is added to the obtained dispersion to stop particle growth (aggregation). I let you. Next, the obtained dispersion was heated and stirred at 80 ° C. to advance the fusion of the particles. When the average circularity of the particles in the dispersion was measured using a measuring device “FPIA-2100” (manufactured by Sysmex) (the number of detected HPF was 4000), the average circularity reached 0.955. Then, the dispersion was cooled to 30 ° C. to stop the fusion of the particles. Thus, a toner dispersion liquid 1 containing toner base particles 1 was obtained.

  The toner base particles 1 are separated from the obtained toner dispersion 1, washed and dried, and 1% by mass of hydrophobic silica particles and 1.2% by mass of hydrophobic titanium oxide particles are added to the obtained toner base particles 1. Then, using a Henschel mixer, mixing was performed for 20 minutes under the condition of a peripheral speed of the rotating blades of 24 m / s, and the obtained mixed powder was passed through a 400 mesh sieve to separate coarse powder. Thus, toner particles 1 in which an external additive was adhered to the surface of toner base particles 1 were obtained. Further, to the toner particles 1, a ferrite carrier having a volume average particle diameter of 60 μm coated with a silicone resin was added and mixed so that the toner particle concentration was 6% by mass. Thus, toner 1 which is a two-component developer was manufactured.

Further, the content of ArPSS1 in the toner base particles 1 was detected by the following method and found to be 0.003% by mass.
[Detection method]
1 g of toner base particles 1 is dissolved in 50 mL of chloroform, the surfactant is extracted from the chloroform layer with 100 mL of ion-exchanged water, and then the chloroform layer is extracted once more with 100 mL of ion-exchanged water. Measurement is performed under the following measurement conditions by high performance liquid chromatography (HPLC) measurement using the aqueous layer) as a test solution.
Column used: ODS-3
Column length: 150mm
Column temperature: 40 ° C
Eluent A: 0.1 M ammonium acetate buffer (pH 5)
Eluent B: Methanol Gradient: B65% (0 min)-B100% (30 min)
Flow rate: 1.0 mL / min Detector: Corona CAD

[Production of Toners 2-8, 17 and 18]
Respective toner dispersions 2 to 8, 17 and 18 were obtained in the same manner as in the production of toner 1 except that PEs dispersions L2 to L7, L9, L16 and L17 were used in place of PEs dispersion L1, respectively. Each of 2-8, 17 and 18 was produced. The SS content in each of the toner base particles 2 to 8, 17 and 18 was in the range of 0.002 to 0.008% by mass.

[Production of Toners 9 to 16, 19 and 20]
The PEs dispersion L2 was added instead of the PEs dispersion L1 to associate the particles, and aggregation of the associated particles was performed until the volume-based median diameter of the associated particles was 6.0 μm, and then the obtained dispersion In addition, 20 parts by mass of each of PEs dispersions L8 to L15, L17 and L18 in terms of solid content are further added over 20 minutes, and the dispersion is stirred at the same temperature for 15 minutes, and then the aqueous sodium chloride solution is added. Each of the toner dispersions 9 to 16, 19 and 20 was obtained in the same manner as in the production of the toner 1 except that the growth of the particles was stopped by adding to the dispersion, and the toners 9 to 16, 19 and 20 were respectively obtained. Manufactured. The SS content in each of the toner base particles 9 to 16, 19 and 20 was in the range of 0.002 to 0.008% by mass.

[Evaluation of cohesiveness]
(1) Particle size distribution For each of the toner particles to 20, a coefficient of variation CV in the volume-based particle size distribution was determined, and the particle size distribution of the toner particles was evaluated according to the following criteria. In this evaluation, “◯” and “Δ” are determined as non-defective products.
○: CV is less than 18% △: CV is 18% or more and less than 20% ×: CV is 20% or more

  The coefficient of variation CV is a measuring device having “Multisizer 3” (manufactured by Beckman Coulter, Inc.) and a computer system mounted with data processing software “Software V3.51” connected thereto. Measured and calculated. Specifically, 0.02 g of each of the toner particles 1 to 20 is added to 20 mL of a surfactant solution to be acclimatized, and the sample solution obtained by sufficiently dispersing the sample solution is used as “ISOTONII” (Beckman in the sample stand).・ Pipe into a beaker containing Coulter) until the displayed concentration of the measuring device is 8%. In the measurement apparatus, the volume-based coefficient of variation (CV) is measured with a measurement particle count of 25,000 and an aperture diameter of 100 μm.

  The surfactant solution is an aqueous solution obtained by diluting a neutral detergent 10 times with pure water for the purpose of dispersing toner particles. Further, by setting the display density in the measuring apparatus to about “8%” as described above, a reproducible measurement value can be obtained.

(2) Measurement of the amount of fine powder After toner particles 1 to 20 were blended with an aqueous solution containing a surfactant and sufficiently dispersed, the measurement condition HPF (high) was measured by “FPIA-3000” (manufactured by Sysmex). In the magnification imaging mode, photographing is performed at an appropriate density of 3,000 to 10,000 HPF detections, and the ratio Rn (% based on the number of particles having a particle diameter of 3 μm or less (0.6 μm or more) to all toner particles ) And the amount of fine powder was evaluated according to the following criteria. In this evaluation, “◯” and “Δ” are determined as non-defective products.
○: Rn is less than 0.5% Δ: Rn is 0.5% or more and less than 1.0% ×: Rn is 1.0% or more

(3) Measurement of coarse powder amount For each of the toner particles 1 to 20, a particle size of 10 μm or more with respect to all the toner particles is obtained from the result of photographing at the appropriate density in the above mode using “FPIA-3000” (manufactured by Sysmex). The ratio Rv (%) on the volume basis of particles of 30 μm or less) was determined, and the amount of fine powder was evaluated according to the following criteria. In this evaluation, “◯” and “Δ” are determined as non-defective products.
○: Rv is less than 1.0% Δ: Rv is 1.0% or more and less than 2.0% ×: Rv is 2.0% or more

  Table 3 shows production conditions and evaluation results for the toners 1 to 20. In the table, “after completion of temperature increase” represents “after temperature increase (80 ° C.) of the dispersion before addition of PEs dispersion”, and “after 6 μm” indicates “resin in resin dispersion” “After the volume average particle diameter (median diameter) of the associated particles due to particle aggregation becomes 6 μm”. The particle size at the end point of the growth of the toner base particles in the present invention can be arbitrarily selected and is not limited to the value (6 μm) in the above embodiment.

  As apparent from Table 3, in each of the toners 1 to 3 and 5 to 11, the particle size distribution is sufficiently sharp, and the generation of fine powder and coarse powder is sufficiently suppressed. Therefore, it can be seen that when the toner base particles are manufactured, the toner base particles have a relatively uniform particle size and generation of fine powder and coarse powder is sufficiently suppressed.

  On the other hand, in toners 4 and 12, the suppression of the generation of fine powder and coarse powder is insufficient. This is because the content of ArPSS1 in the PEs dispersions L4 and L11 is insufficient, so that the aggregation of PEs particles alone occurs in the aggregation process after the addition of the PEs dispersion, or the vinyl-based PEs particles This is probably because rapid aggregation occurs in the process of aggregation with the resin.

  Further, the toner 13 is insufficient in suppressing the generation of fine powder. This is thought to be because, since the content of ArPSS1 that promotes the aggregation of the PEs particles and the growth complete particles is large, aggregation of the Pes particles simultaneously occurs when the PEs dispersion is added. “Growth complete particles” means particles that have been grown as toner base particles. For example, the structure of the toner is controlled by a core / shell structure or a domain-matrix structure (domains are arranged on the surface layer). These are core particles and matrix particles when performing the water granulation method.

  Further, the toner 14 is insufficient in suppressing the generation of fine powder. This is thought to be because the pH of the PEs dispersion L13 is too low, so that when the PEs dispersion is added, the dissociation of the carboxyl groups between the Pes particles becomes insufficient and unstable, and aggregation of the Pes particles occurs. .

  Further, the toner 15 is insufficient in suppressing the generation of coarse powder. This is because the pH of the PEs dispersion L14 is too high, the amount of dissociation of carboxyl groups between the Pes particles becomes excessive when the PEs dispersion is added, and the cohesion is increased (alkali thickening). This is thought to be due to the fact that a plurality of coagulations occur simultaneously (that is, rapid aggregation occurs).

  In addition, the toner 16 has insufficient sharpness of particle size distribution and insufficient generation suppression of fine powder. This is because, since the anionic surfactant AlPSS3 in the PEs dispersion does not have an aromatic ring group (phenylene group), aggregation of the polyester particles occurs at the same time as the polyester particles and the vinyl resin particles. This is considered to be because fine particles derived from the aggregates of the polyester particles are likely to be produced due to the aggregation of the polyester particles and the polyester aggregate particles and the vinyl resin particles are aggregated.

  In addition, the toners 17 and 18 are both insufficient in sharpness of the particle size distribution and insufficient in suppressing the generation of fine powder. Further, the toner 19 is insufficient in suppressing the generation of fine powder. This is because the anionic surfactant AlSS3 in the PEs dispersion is a monovalent sulfonic acid type anionic surfactant and does not have an aromatic ring group. This is presumably because it occurs in preference to the aggregation of particles and vinyl resin particles.

  In addition, the toner 20 is insufficient in suppressing the generation of fine powder. This is because although the anionic surfactant ArSS4 in the PEs dispersion has an aromatic ring group, it is a monovalent sulfonic acid type anionic surfactant. It is thought that it occurs in preference to the aggregation with the resin particles.

  According to the present invention, toner particles having a desired particle diameter and substantially free of fine powder and coarse powder can be obtained. In addition, according to the present invention, a water-based polyester particle dispersion having excellent dispersibility over time, which is useful as a material for producing such toner particles, can be obtained. Therefore, according to the present invention, further improvement in the productivity of high-performance toner used in the electrophotographic image forming technology is expected, and further spread and development of the image forming technology are expected.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 30 Image processing part 40 Image forming part 41Y, 41M, 41C, 41K Image forming unit 42 Intermediate transfer unit 43 Secondary transfer unit 50 Paper transport part 51 Paper feed part 51a, 51b, 51c Paper feed tray unit 52 Ejection Paper unit 52a Paper discharge roller 53 Transport path unit 53a Registration roller pair 60 Fixing device 62 Fixing roller 63 Heating belt 64 Pressure roller 110 Image reading unit 111 Paper feeding device 112 Scanner 112a CCD sensor 411 Exposure device 412 Developing device 413 Photosensitive drum 414 Charging device 415 Drum cleaning device 421 Intermediate transfer belt 422 Primary transfer roller 423, 431 Support roller 423A Backup roller 426 Belt cleaning device 431A Secondary transfer roller 43 2 Secondary transfer belt D Original S Paper

Claims (13)

A water-based polyester particle dispersion containing at least water, an anionic surfactant having two or more sulfonic acid groups and an aromatic ring portion, and polyester particles,
A water-based polyester particle dispersion in which the content of the anionic surfactant with respect to the polyester is 3 to 25% by mass and the pH is 7 to 10.   The aqueous polyester particle dispersion according to claim 1, wherein the polyester is one or both of a crystalline polyester having no sulfonic acid group and an amorphous polyester having no sulfonic acid group.   The aqueous polyester particle dispersion according to claim 1 or 2, wherein the volume average particle diameter of the polyester particles is 50 to 500 nm.   The water-based polyester particle dispersion according to any one of claims 1 to 3, wherein the content of the polyester particles is 15 to 50% by mass. Dissolving polyester in an organic solvent;
Adding an aqueous medium under stirring to the obtained polyester solution to produce an emulsion in which droplets of the polyester solution are dispersed in the aqueous medium;
Removing the organic solvent from the emulsion;
An anionic surfactant having two or more sulfonic acid groups and an aromatic ring moiety in an amount of 2 to 20% by mass with respect to the polyester, from the polyester solution, the emulsion, and the emulsion from which the organic solvent has been removed. Adding to at least one selected from the group consisting of:
Adjusting the pH of one or both of the emulsion and the emulsion from which the organic solvent has been removed by adding a basic compound so that the final pH is 7 to 10.
A method for producing an aqueous polyester particle dispersion.   The method for producing an aqueous polyester particle dispersion according to claim 5, wherein one or both of a crystalline polyester having no sulfonic acid group and an amorphous polyester having no sulfonic acid group are used as the polyester.   The method for producing an aqueous polyester particle dispersion according to claim 5 or 6, wherein the polyester particles have a volume average particle diameter of 50 to 500 nm.   Content of the said polyester particle | grain is a manufacturing method of the aqueous | water-based polyester particle dispersion liquid as described in any one of Claims 5-7 which is 15-50 mass%. A step of aggregating at least a vinyl resin particle having a sulfonic acid group in an aqueous medium in the presence of an aggregating agent to form an associated particle;
In one or both of the generation of the association particles and after the generation, an aqueous polyester particle dispersion is added to the aqueous medium, and the polyester particles in the aqueous polyester particle dispersion are further aggregated into the association particles to form the association. Growing the particles;
Producing toner base particles by fusing and integrating the vinyl resin particles and the polyester particles in the associated particles;
A method for producing a toner comprising:
The aqueous polyester particle dispersion contains water, an anionic surfactant having two or more sulfonic acid groups and an aromatic ring portion, and polyester particles, and the content of the anionic surfactant relative to the polyester Is 3 to 25% by mass, and a water-based polyester particle dispersion having a pH of 7 to 10 is used.
Toner manufacturing method. Further comprising adjusting the pH of the aqueous polyester particle dispersion before adding to the aqueous medium,
For the aqueous polyester particle dispersion added to the aqueous medium, the aqueous polyester particle dispersion whose pH is further adjusted is used.
The method for producing a toner according to claim 9.   11. The method for producing a toner according to claim 9, wherein one or both of a crystalline polyester having no sulfonic acid group and an amorphous polyester having no sulfonic acid group are used as the polyester.   The toner production method according to claim 9, wherein a volume average particle diameter of the polyester particles is 50 to 500 nm.   The toner production method according to claim 9, wherein a content of the polyester particles in the aqueous polyester particle dispersion is 15 to 50% by mass.

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