JP4102380B2 - Toner for developing electrostatic image, method for producing the same, electrostatic image developer using the same, image forming method and formed image using the same - Google Patents

Description

  The present invention relates to a toner for developing an electrostatic image used in an image forming apparatus using an electrophotographic system, a method for producing the same, an electrostatic image developer using the toner, an image forming method using the toner, and a formed image. More specifically, the present invention relates to facilitating the production of toner having excellent reproducibility.

  Along with recent remarkable development of OA equipment, copiers, printers, facsimile machines, and the like that perform printing using an electrophotographic system have become widespread. In general, an image forming apparatus using an electrophotographic system forms an image through a charging process, an exposure process, a development process, a transfer process, a cleaning process, a fixing process, and the like.

  In the charging step, the surface of the photoreceptor is uniformly charged in a dark place. In the exposure step, the original image is projected onto the charged photoconductor, so that the charged portion is removed and an electrostatic latent image is formed on the surface of the photoconductor. In the development step, a toner image (visible image) is formed by binding toner to the electrostatic latent image formed on the surface of the photoreceptor. In the transfer process, a recording medium such as paper or sheet is brought into contact with the toner image formed on the surface of the photoconductor, and corona discharge is performed from the side opposite to the surface of the recording medium that is in contact with the toner image. The toner image is transferred to the recording medium by applying a charge of the polarity to the recording medium. In the fixing step, the toner image transferred to the recording medium is fixed by means such as heating and pressing. In the cleaning process, the toner remaining on the surface of the photoreceptor without being transferred to the recording medium is collected. An image forming apparatus using an electrophotographic system forms a desired image on a recording medium through the above steps.

  As a method for producing an electrostatic image developing toner used in an image forming apparatus using an electrophotographic system, there are a dry method and a wet method. Examples of the dry method include a pulverization method. The pulverization method is a method for obtaining toner by melting and kneading a resin, pigment (colorant), wax, and the like, and finely pulverizing and classifying the obtained kneaded material with a pulverizer or the like. It is used. The toner is desired to have a small particle size in order to achieve high image quality of the formed image. However, in the pulverization method, energy and time required for pulverization increase, and the manufacturing process becomes complicated. Further, since the yield is further lowered, there is a problem that the manufacturing cost is remarkably increased.

Examples of the wet method include a suspension polymerization method and an emulsion polymerization method. The suspension polymerization method is a method for obtaining a toner by suspension polymerization of a synthetic resin monomer such as a vinyl monomer in an aqueous medium containing a pigment (see Patent Documents 1 and 2).
On the other hand, the emulsion polymerization method is a method in which an aqueous dispersion of synthetic resin particles and a dispersion of pigment in an organic solvent are mixed to form aggregated particles of synthetic resin particles and pigment, and the aggregated particles are heated and melted. This is a method for obtaining toner (see Patent Documents 3 to 6). Although this method will be described later, since the surfactant is contained in the resin particle dispersion, which is a starting material for toner production, the surfactant remains in the produced toner.

As another wet method, there is a method using phase inversion emulsification (see Patent Document 7). The phase inversion emulsification method involves dissolving or dispersing a self-water dispersible resin and pigment in an organic solvent, adding a neutralizing agent that neutralizes the dissociation group of the resin, and adding water while stirring. In this method, toner particles are obtained by phase inversion emulsification of resin solution droplets containing a pigment or the like.
As another wet method, toner particles are obtained by granulating a solution in which a resin is dissolved or dispersed in a solvent in which the resin is soluble in an aqueous medium containing an inorganic dispersant, removing the solvent, and drying. There is a method (Patent Document 8). In this method for producing an electrostatic image developing toner, a material containing a polyester resin and a pigment is dissolved or dispersed in a solvent in which the polyester resin can be dissolved, and the resulting solution is granulated in an aqueous medium containing an inorganic dispersant. Then, the solvent is removed to produce a toner.

  As other conventional techniques, techniques similar to the technique of Patent Document 8 are described in Patent Documents 9 and 10. The method for producing a negatively charged toner for developing an electrostatic image in Patent Document 9 and the method for producing a positively charged toner for developing an electrostatic image in Patent Document 10 use an inorganic dispersant having an average particle diameter of 0.7 to 5 μm. Except for this, the toner is manufactured in the same manner as the method for manufacturing a toner for developing an electrostatic charge image in Patent Document 8. The method for producing a negative charge toner for developing an electrostatic image in Patent Document 9 uses a negative charge control agent, and the method for producing a positive charge toner for developing an electrostatic image in Patent Document 10 is positively charged. Sex charge control agent is used.

  As another conventional technique, a technique similar to the techniques of Patent Documents 8 to 10 is described in Patent Document 11. In the method for producing a toner for developing an electrostatic charge image in Patent Document 11, a polymerizable vinyl monomer containing styrene, a styrene derivative, a (meth) acrylic acid alkyl ester and a mixture thereof as a main component as a binder resin is polymerized. The toner is produced in the same manner as in the method for producing an electrostatic charge image developing toner disclosed in Patent Document 8, except that a vinyl polymer obtained in this manner is used.

  As another conventional technique, Patent Document 12 describes a technique similar to the techniques of Patent Documents 8 to 11. In the method for producing a toner for developing an electrostatic charge image of Patent Document 12, after toner particles are prepared, the toner is further washed with water until the difference in electric conductivity between water before washing and water after washing becomes 200 μS / cm or less. Except for this, the toner is manufactured in the same manner as the method for manufacturing a toner for developing an electrostatic charge image in Patent Document 8.

As another conventional technique, Patent Document 13 describes a technique similar to the techniques of Patent Documents 8 to 12. The method for producing the toner for developing an electrostatic charge image of Patent Document 13 is produced in the same manner as the method for producing the toner for developing an electrostatic charge image of Patent Document 8, except that a surfactant is further added to the aqueous medium.
As another conventional technique, a technique similar to the techniques of Patent Documents 8 to 13 is described in Patent Document 14. The toner production method of Patent Document 14 is the production of the electrostatic image developing toner of Patent Document 8, except that an aqueous dispersion containing a surfactant and an inorganic dispersant having an average particle size of 0.1 to 2 μm is used. Produced in the same way as the method.

  In the method for producing a toner by the wet method as described above, an organic solvent, a resin monomer, a surfactant and the like remain in the obtained toner. Such components ooze out of the toner and damage members such as a developing roller when the toner is actually used for developing an electrostatic image. Further, the chargeability of the toner varies. Therefore, after the toner is manufactured, a step of removing the organic solvent, the monomer, the surfactant and the like from the toner is required. However, in such a removal step, variations in the shape of the obtained toner and its chargeability tend to occur due to subtle variations in operating conditions such as pressure, temperature, and time. Therefore, in order to obtain a toner having a uniform shape, it is necessary to adjust the operation condition to an optimum condition, and it is very difficult to realize it. Further, since a large amount of an organic solvent, a monomer, a surfactant, and the like that give a large load to the environment are used, facilities for processing these are necessary, and the manufacturing cost of the toner is increased.

Further, the toner obtained by the conventional wet method as described above is used for the image density of the image formed on the recording medium and the image quality such as “fogging”, the dispersibility of the pigment on the recording medium, and the recording medium. Not all of the toner characteristics such as transfer rate to are excellent.
Therefore, as another conventional technique, Patent Document 15 describes a toner manufacturing method that does not use an organic solvent and does not use a polymerization reaction when forming particles that are toner. In the method for producing a toner composition of Patent Document 15, a pigment aqueous dispersion in which a pigment is dispersed in water using sodium sulfonated polyester is added to an emulsion in which sodium sulfonated polyester is dispersed in water. The toner is manufactured by adding an alkali halide solution to form an aggregate.

Similarly, Patent Document 16 describes a method for producing a toner using a self-dispersing resin containing a hydrophilic ethylenically unsaturated monomer. Patent Document 16 discloses that a styrene derivative is a sodium or potassium sulfonate salt as a hydrophilic ethylenically unsaturated monomer. In this document, a sulfonic acid metal salt is a self-dispersing resin having a hydrophilic machine, and a toner is prepared using a polyvalent metal salt as a flocculant.
Further, Patent Document 17 is cited as a patent using self-dispersing polyester. This discloses a method for producing a toner using a mixture of a vinyl resin dispersion and a self-dispersing polyester. The self-dispersing polyester disclosed therein is preferably a polyester containing no trivalent monomer. Further, it is disclosed that soft flocculation is performed using an ionic surfactant as a flocculant.

JP 57-154253 A JP 59-62870 JP-A 63-186253 JP-A 63-282758 JP-A-63-282749 JP-A-10-26842 JP-A-5-66600 JP-A-7-152202 JP-A-7-168395 Japanese Patent Laid-Open No. 7-168396 JP 7-219267 A JP-A-8-179555 JP-A-8-179556 Japanese Patent Laid-Open No. 9-230624 JP 10-39545 A JP 2002-131977 A JP 2004-354411 A

It is desirable that the toner for developing an electrostatic charge image does not contain unnecessary components such as an organic solvent and a monomer, can be easily manufactured, and has excellent toner characteristics.
In the toner production method of Patent Document 15, a toner composition is produced by aggregating a pigment dispersed in water with sodium sulfonated polyester as a toner component and sodium sulfonated polyester dispersed in water. And a toner composition production method capable of producing a toner composition so as not to contain unnecessary components such as an organic solvent and a monomer. However, simply dispersing the pigment using sodium sulfonated polyester results in insufficient dispersibility of the pigment, resulting in agglomeration of only the pigment, and toner properties such as color reproducibility are not satisfactory. In other words, a toner composition having excellent toner characteristics cannot be produced. Further, the toner composition produced by this method has a problem that the charging characteristics become unstable due to environmental conditions, and the use is limited depending on the environmental conditions, which is derived from a sulfonic acid group which is a hydrophilic group. It is considered a thing.

Similarly, in the toner production method disclosed in Patent Document 16, although the dispersibility of the pigment is maintained, the environmental characteristics of the produced toner are the same problems as above because the hydrophilic group is a sulfone metal salt. Is included.
Furthermore, with the toner disclosed in Patent Document 17, it is difficult to first self-disperse the polyester, and it is very difficult to control the particle size because of soft aggregation caused by a surfactant.

Thus, according to the present invention, anionic surfactant or a pigment aqueous dispersion dispersed by using a dispersing agent comprising a nonionic surfactant, a binder containing a self-dispersible polyester binder resin particles A mixed liquid preparation step of mixing a resin particle aqueous dispersion with a wax fine particle aqueous dispersion containing natural and / or synthetic wax fine particles to be bound to the self-dispersing polyester binder resin particles ; Adding a polyvalent metal salt as an aggregating agent while stirring the mixed solution to form an aggregate in which at least a dispersed pigment is bound to the self-dispersing binder resin particles; and A mixed liquid containing the aggregate is heated to form a particle forming step for uniformizing the particle size and shape of the aggregate, and the aggregate is washed with pure water, then washed with water having a pH of 6 or less, and then pure water. Wash with The self-dispersing polyester binder resin particles are synthesized from polyhydric carboxylic acids including polyhydric carboxylic acids having at least three carboxyl groups and a polyhydric alcohol, and include a washing step of drying thereafter. It has carboxylic acid as a hydrophilic group in the chain,
Provided is a method for producing a toner for developing an electrostatic image , wherein the polyvalent carboxylic acid having at least three carboxyl groups is introduced into a reaction system at the end of polymerization of the acid and the alcohol. .
According to another aspect of the present invention, there is provided an electrostatic image developing toner produced by the method for producing an electrostatic image developing toner.
According to still another aspect of the present invention, there is provided an electrostatic charge image developer comprising the above electrostatic charge image developing toner and a carrier.
According to still another aspect of the present invention, an electrostatic latent image is formed on a photoconductor, and the electrostatic latent image on the photoconductor is developed using the electrostatic image developer to form a toner image. An image forming method including a step of forming and transferring and fixing a toner image onto a recording medium, and a formed image formed by the image forming method are provided.

According to the method for producing a toner for developing an electrostatic charge image of the present invention, an aqueous solution containing an aggregating agent is added to a self-dispersion-type binder while stirring a liquid mixture obtained by mixing at least a pigment and a self-dispersion binder resin in water. The toner is produced by forming an aggregate in which the dispersed pigment is bound to the resin particles. As a result, it is possible to easily produce a toner without including unnecessary components such as a dispersant for emulsifying and dispersing a resin, an organic solvent, and a binder resin constituent monomer, which are necessary in the prior art. Further, in the conventional method of melt-kneading the pigment and the binder resin, the polymer is cut by shear stress to change the molecular weight, and the desired toner characteristics can be obtained by changing from the molecular weight distribution at the time of preparation. Although it may not be possible, the present invention does not cause such a problem. Furthermore, by using a dispersed pigment having excellent dispersibility, the dispersed particle diameter of the pigment in the toner can be reduced, and a toner having excellent toner characteristics such as color reproducibility can be manufactured.
Further, according to the toner for developing an electrostatic charge image of the present invention, since it is produced by the above production method, there are few unnecessary components such as an organic solvent and a binder resin constituting monomer, and the toner characteristics are excellent.
Furthermore, in the electrostatic image developing toner of the present invention, since the hydrophilic group has a carboxylic acid, it is hydrophobized by washing with an acid, and has an effect of being excellent in environmental stability compared to a polyester resin containing a sulfonic acid group. is there.

  The present invention is a self-dispersion type synthesized from an aqueous pigment dispersion, a polyvalent carboxylic acid containing at least three carboxyl groups and / or an acid anhydride thereof and a polyhydric alcohol, and having a carboxylic acid as a hydrophilic group in the main chain. A mixed liquid preparation step of preparing a mixed liquid by mixing at least a binder resin particle aqueous dispersion containing polyester binder resin particles, and adding a polyvalent metal salt as an aggregating agent while stirring the mixed liquid A method for producing a toner for developing electrostatically charged images, comprising an agglomerate forming step of forming an agglomerate in which at least a dispersed pigment is bound to the self-dispersing binder resin particles.

  FIG. 1 is a process diagram showing a method for producing an electrostatic image developing toner of the present invention. In the toner manufacturing method according to the embodiment of the present invention, the mixed liquid preparation step S1, the aggregate formation step S2, the particle formation step S3, and the cleaning step S4 are performed in this order.

In the mixed liquid preparation step S1, toner components such as individually dispersed pigments and self-dispersing binder resins are mixed with water to prepare a mixed liquid. In the agglomerate forming step S2, an aqueous solution containing an aggregating agent is added to the mixed solution to form toner as an agglomerate in an aqueous medium. Further, by performing steps S3 and S4, a toner having more excellent toner characteristics can be obtained. Specifically, in the particle forming step S3, the aqueous medium containing the aggregate is heated to form the aggregate. In the washing step S4, the agglomerated particles are washed and dried.
Hereinafter, the above steps will be described in more detail.

  In the mixed liquid preparation step S1, a pigment aqueous dispersion containing a dispersed pigment is prepared by previously dispersing a dispersion pigment and a self-dispersing binder resin, which will be described later, in water using an agitator (emulsifier or disperser). And a binder resin particle aqueous dispersion containing self-dispersing binder resin particles, respectively, and the resulting pigment aqueous dispersion and binder resin particle aqueous dispersion are mixed and mixed to include a toner component. Obtain a liquid. Preferably, the binder resin particle aqueous dispersion and the pigment aqueous dispersion are mixed so as to contain 80 to 99% by weight of a self-dispersing binder resin in a solid content concentration and 0.1 to 20% by weight of a dispersed pigment, The prepared liquid mixture is obtained by stirring at room temperature for 1 to 5 hours using a stirrer. Furthermore, in the mixed liquid preparation step S1, a wax fine particle aqueous dispersion containing natural and / or synthetic wax fine particles emulsified in water may be mixed with the above mixed liquid, and the amount thereof is 0.1 to 0.1 in terms of solid content concentration. 20% by weight.

In the agglomerate forming step S2, a predetermined amount (for example, 0.5 part with respect to 100 parts by weight of the toner component) is added to a mixed solution containing toner components such as pigments and self-dispersing binder resin particles (including wax fine particles in some cases). (About 20 parts by weight) of an aggregating agent is added and mixed by stirring to form an agglomerate containing a toner component. Therefore, unnecessary components other than the toner component, for example, a dispersant for dispersing the pigment, an organic solvent, a binder resin constituting monomer, and the like are not included in the toner.
This step S2 is preferably performed at room temperature, but may be heated to near the glass transition temperature (Tg) of the self-dispersing binder resin. Furthermore, in this step S2, it is preferable to stir the mixed solution by a mechanical shearing force using a stirrer from the viewpoint that it becomes easy to form aggregates into particles having a uniform particle size and shape. .
Furthermore, in this aggregate formation step S2, a predetermined amount (for example, 1 to 5% by weight of the total amount of the resin used) is mixed with a binder resin particle aqueous dispersion that does not contain a pigment and contains self-dispersing binder resin particles. It is also possible. By including this operation, the toner surface property can be intentionally controlled. For example, a difference in charge amount is likely to occur between a toner having a conductive material such as carbon black on the toner surface layer and a toner having a colored pigment (cyan, magenta, yellow, etc.) on the surface layer, and the developer design is individual. Forced to consider. Since the charge characteristics are mainly governed by the toner surface properties, a difference in charging performance due to the pigments can be reduced by providing a layer on which the pigment is not directly exposed. Furthermore, when the resin layer is provided on the surface layer, a secondary effect that the spent of the carrier by the wax can be improved can be expected. In this case, the resin amount in the binder resin particle aqueous dispersion to be mixed in the previous mixed solution preparation step S1 is reduced in advance by a predetermined amount. Moreover, in order to prevent reaggregation of aggregates, a surfactant may be added, or sodium hydroxide or the like may be added to adjust the pH to 8 or more.

In the particle forming step S3, by heating the aqueous medium containing the obtained aggregate, the aggregate can be made into particles having a substantially uniform particle size and shape. In this case, it is preferable to heat the self-dispersing binder resin to a temperature equal to or higher than the glass transition temperature and adjust the particle diameter to be 1 to 20 μm. By doing so, the toner has a substantially uniform particle diameter and shape. Particles can be easily obtained.
Further, in this particle forming step S3, in order to control the toner shape, it is possible to add a binder resin particle aqueous dispersion containing a self-dispersing binder resin to form an aggregate again. At this time, a surfactant may be added to prevent reaggregation of the aggregates, or sodium hydroxide or the like may be added to adjust the pH to 8 or higher. In this case as well, it is desirable to reduce the amount of resin in the binder resin particle aqueous dispersion mixed in the previous mixed solution preparation step S1 in advance by a predetermined amount.

  In the washing step S4, the mixed solution containing the toner (aggregate) is cooled to, for example, room temperature, the mixed solution is filtered to remove the supernatant, and the separated toner is washed with water. For cleaning, it is preferable to use pure water having a conductivity of 20 μS / cm or less, and it is preferable to wash the toner until the supernatant of the water from which the toner has been cleaned has a conductivity of 50 μS / cm or less. Cleaning of the toner using pure water may be performed by a batch method or a continuous method. Cleaning of the toner with pure water is performed to remove unnecessary components other than the toner components such as impurities that affect the chargeability of the toner and unnecessary flocculants that did not participate in the aggregation. A toner that does not contain unnecessary components can be easily produced. Further, the step of washing with water having a pH of 6 or less may be included one or more times in the washing step with pure water, whereby impurities are more sufficiently removed. Thereafter, the toner washed in this way may be separated from the washing water by filtration and dried using, for example, a vacuum dryer. A desired additive (for example, a charge control agent, a release agent, an external additive, etc.) may be added to the toner obtained by drying.

[Description of Toner Component]
(Self-dispersing binder resin particles)
In the present invention, the resin constituting the self-dispersing binder resin particles is not particularly limited as long as it is a resin that can be dispersed in water (resin that can be made into particles), and known resins can be used. Vinyl copolymer resin, polyurethane resin, epoxy resin, and the like, and these resins can be used alone or in combination. Of these, polyester resins and vinyl copolymer resins are preferable, and polyester resins are particularly preferable in consideration of improving powder flowability, low-temperature fixability, secondary color reproducibility, and the like of the obtained toner particles.

  As described above, the self-dispersing binder resin particles in the present invention preferably have a polyester resin as a main component, and the ratio of the polyester resin to the whole resin constituting the self-dispersing binder resin particles is 50% by weight or more. It is preferably 80% by weight or more, more preferably 90% by weight or more. This is to develop the color reproducibility as a toner and the function of adhesion to paper. The polyester resin used for the self-dispersing binder resin particles is obtained by polycondensation of an acid component and an alcohol component. The acid component mainly uses polyvalent carboxylic acids, and the alcohol component mainly contains polyvalent alcohols. A polyester resin polycondensed using is preferred.

  Examples of the polyvalent carboxylic acids include terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, anthracene dipropionic acid, anthracene dicarboxylic acid, diphenic acid, and sulfoterephthalic acid. Aromatic dicarboxylic acids such as 5-sulfoisophthalic acid, 4-sulfophthalic acid, 4-sulfonaphthalene-2,7 dicarboxylic acid, 5 (4-sulfophenoxy) isophthalic acid, p-oxybenzoic acid and p- (hydroxyethoxy) ) Aromatic oxycarboxylic acids such as benzoic acid, aliphatic dicarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid and dodecanedicarboxylic acid, fats such as fumaric acid, maleic acid, itaconic acid, mesaconic acid and citraconic acid Group unsaturated polycarboxylic acid, Trivalent or higher polyvalent carboxylic acids such as aromatic unsaturated polycarboxylic acids such as nylene diacrylic acid, alicyclic dicarboxylic acids such as hexahydrophthalic acid and tetrahydrophthalic acid, trimellitic acid, trimesic acid and pyromellitic acid Examples thereof include acids and / or acid anhydrides thereof, and these can be used alone or in combination.

  In the present invention, the acid component may contain monocarboxylic acids. As monocarboxylic acids, aromatic monocarboxylic acids are preferred. Examples of the aromatic monocarboxylic acid include benzoic acid, chlorobenzoic acid, bromobenzoic acid, parahydroxybenzoic acid, naphthalenecarboxylic acid, anthracenecarboxylic acid, 4-methylbenzoic acid, 3-methylbenzoic acid, salicylic acid, thiosalicylic acid, Phenylacetic acid, lower alkyl esters thereof, sulfoammonium monoammonium salt, sulfobenzoic acid monosodium salt, cyclohexylaminocarbonylbenzoic acid, n-dodecylaminocarbonylbenzoic acid, tertiary butylbenzoic acid and tertiarybutylnaphthalenecarboxylic acid, etc. Can be mentioned.

  In the acid component, the content of polyvalent carboxylic acids is 70 mol% or more, preferably 80 mol% or more, particularly preferably 90 mol% or more, and aromatic polyvalent carboxylic acids are preferred as the polyvalent carboxylic acids. Further, the aromatic polyvalent carboxylic acid preferably contains terephthalic acid and isophthalic acid. The content of terephthalic acid is preferably 40 to 95 mol%, more preferably 60 to 95 mol%, and particularly preferably 70 to 90 mol% in the acid component. Moreover, it is preferable that content of isophthalic acid is 5-60 mol% in an acid component. Further, the total content of terephthalic acid and isophthalic acid is preferably 80 mol% or more, more preferably 90 mol% or more in the acid component. In the present invention, the polyvalent carboxylic acids include trivalent or higher polyvalent carboxylic acids such as trimellitic acid, trimesic acid and pyromellitic acid and / or their acid anhydrides such as pyromellitic anhydride and cyclohexane. It is particularly preferable that -1,2,3,4-tetracarboxylic acid-3,4-anhydride, ethylene glycol bisanhydro trimellitate, etc. are contained alone or in a plurality of selectively, and the content thereof is It is preferable that it is 0.5-8 mol% in an acid component, and 0.5-6 mol% is especially preferable. When monocarboxylic acids are contained in the acid component, the content thereof is preferably 2 to 25 mol% during acidification, and more preferably 5 to 20 mol%. This is because the self-dispersibility of the polyester resin is maintained.

In the present invention, examples of the polyhydric alcohols include aliphatic polyhydric alcohols, alicyclic polyhydric alcohols, and aromatic polyhydric alcohols. Examples of the aliphatic polyhydric alcohol include ethylene glycol, propylene glycol, 1,3-propanediol, 2,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6- Hexanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 2,2,4-trimethyl-1,3-pentanediol, aliphatic diols such as polyethylene glycol, polypropylene glycol and polytetramethylene glycol, trimethylolethane, trimethylol Triols such as propane, glycerin and pentaelsitol, tetraols and the like can be mentioned. Examples of the alicyclic polyhydric alcohol include 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, spiroglycol, hydrogenated bisphenol A, ethylene oxide adduct and propylene oxide adduct of hydrogenated bisphenol A, tri Examples include cyclodecanediol and tricyclodecane dimethanol. Examples of the aromatic polyhydric alcohol include para-xylene glycol, meta-xylene glycol, ortho-xylene glycol, 1,4-phenylene glycol, 1,4-phenylene glycol ethylene oxide adduct, bisphenol A, and bisphenol A ethylene oxide addition. And propylene oxide adducts. Furthermore, examples of the polyester polyol include a lactone polyester polyol obtained by ring-opening polymerization of a lactone such as ε-caprolactone.
In the present invention, monoalcohols may be included in the polyhydric alcohols as the alcohol component. Examples of monoalcohols include aliphatic alcohols, aromatic alcohols, and alicyclic alcohols.

  In the alcohol component forming the polyester resin of the present invention, the content of polyhydric alcohol is 50 mol% or more, preferably 70 mol% or more, more preferably 80 mol% or more, particularly preferably 90 mol% or more. The alcohols preferably include aliphatic diols and / or alicyclic diols. As the aliphatic diol, ethylene glycol, propylene glycol, and 2,3-butanediol are preferable. Among these, ethylene glycol and propylene glycol are preferable. As the alicyclic diols, tricyclodecane dimethanol, cyclohexane diol, and cyclohexane dimethanol are preferable. In particular, in the present invention, it is preferable that ethylene alcohol and / or propylene glycol is contained in the alcohol component in an amount of 50 mol% or more, preferably 60 mol% or more, more preferably 70 mol% or more.

  The polyester resin constituting the self-dispersing binder resin fine particles is obtained mainly by polycondensation of a raw material divalent or higher polyvalent carboxylic acid and a divalent or higher polyhydric alcohol as described above. The purpose is to broaden the molecular weight distribution of the polyester resin, not to gel the resin. The gelation of the resin makes it difficult to take out the resin from the polymerization apparatus and significantly reduces the productivity. The polyester resin used in the present invention is substantially free of gelation, more specifically, the chloroform insoluble content of the polyester resin is 0.5% by weight or less, preferably 0.25% by weight or less, and The acid value of the polyester resin is 40 mgKOH / g or less, preferably 30 mgKOH / g or less.

  In the present invention, the glass transition point (or softening point) of the polyester resin constituting the self-dispersing binder resin particles is preferably 40 to 80 ° C. (80 to 150 ° C.), more preferably 45 to 80 ° C. (85 to 150 ° C), particularly preferably 50 to 75 ° C (80 to 145 ° C). When the glass transition point is 40 ° C. or the softening point is lower than 80 ° C., the toner formed using the polyester resin particles tends to block, which causes a problem in storage stability. On the other hand, when the glass transition temperature is 80 ° C. or the softening point exceeds 150 ° C., the toner formed using the polyester resin particles has a problem in fixability, and the fixing roll needs to be heated to a high temperature. The material of the fixing roll and the material of the substrate to be transferred are limited.

  The number molecular weight of the polyester resin within the range of the glass transition temperature and the softening point can be selected from a wide range, but the obtained toner particles can be used as a color toner, the fixability to an OHP sheet and the like can be improved. Considering that the offset region shifts to the high temperature side and prevents fixing failure of toner particles to the transfer material, it is preferably 2000 to 200000, more preferably 2000 to 50000, The average molecular weight is 2000 to 30000, preferably 3000 to 25000, and more preferably 3000 to 20000. If the number average molecular weight is larger than 200000, it is difficult to self-disperse, and if it is smaller than 2000, there is a disadvantage that the durability as a toner is inferior.

  As the hydrophilic group contained in the main chain of the self-dispersing binder resin, an ionic group is preferable, and among them, an anionic group is particularly preferable. Specific examples of preferred hydrophilic groups include carboxyl groups, sulfonic acid groups, phosphoric acid groups, phosphonic acid groups, phosphinic acid groups, ammonium salts and metal salts of the above groups. Among these, alkali metal carboxylates More preferred are salts and ammonium carboxylate. In the case of a polyester resin, for example, when introducing an alkali metal carboxylate and an ammonium carboxylate, a polyvalent carboxylic acid such as trimellitic acid and / or an acid anhydride thereof is used at the end of polymerization of the polyester. It is possible to use a method in which a carboxyl group is added to the end of the polymer by introducing it into the polymer, and this is then neutralized with ammonia, sodium hydroxide or the like to exchange for a carboxylate. The ionic group has a function of imparting water dispersibility to the polyester resin, but the counter cation of these ionic group-containing monomers in polymerizing the polyester is preferably a monovalent cation. A self-dispersing polyester resin having a carboxylate as a hydrophilic group has an advantage that it can be hydrophobized by a subsequent washing method.

Next, a method for obtaining particles having a predetermined average particle size and particle size distribution from a self-dispersing resin containing an ionic group will be described. In the case of a polyester resin, the ionic group-containing polyester resin has water dispersibility. An aqueous fine dispersion of a polyester resin containing an ionic group can be produced by a known method. For example, there is a method in which a polyester resin containing an ionic group and a water-soluble organic compound are preliminarily adjusted to 50 to 200 ° C., mixed, and water is added thereto.
As another method, a method of producing by adding a mixture of a polyester resin containing an ionic group and a water-soluble organic compound (for example, a counter cation) to water and further heating to 40 to 120 ° C. and dispersing. There is.
As another method, there is a method in which a polyester resin containing an ionic group is added to a mixed solution of water and a water-soluble organic compound, and the mixture is further heated to 40 to 100 ° C. and stirred.
As the water-soluble organic compound, solvents such as ethanol, butanol, isopropanol, ethyl cellosolve, butyl cellosolve, dioxane, tetrahydrofuran, acetone and methyl ethyl ketone can be used.
The average particle size of self-dispersing binder resin particles such as an aqueous fine dispersion of polyester resin is 0.2 μm or less, preferably 0.01 to 0.18 μm, more preferably 0.01 to 0.15 μm. . When the average particle size of the self-dispersing binder resin particles is larger than 0.2 μm, the aggregated particles become large and it is difficult to control to a desired toner size.

(Pigment)
In the present invention, known pigments can be used, and any of blue, brown, cyan, green, violet, magenta, red and yellow pigments or a mixture thereof may be used. Specifically, anthraquinone pigments, phthalocyanine blue pigments, phthalocyanine green pigments, diazo pigments, monoazo pigments, pyranthrone pigments, perylene pigments, heterocyclic yellow, quinacridone, indigoid pigments and thioindigoid pigments, etc. Is mentioned. Examples of the anthraquinone pigment include pigment red 43, pigment red 194 (perinone red), pigment red 216 (brominated pyrantrone red), and pigment red 226 (pyrantron red). Examples of the phthalocyanine blue pigment include copper phthalocyanine blue and pigment blue 15 which is a derivative thereof. Examples of the pyrerin pigment include pigment red 123 (bell million), pigment red 149 (scarlet), pigment red 179 (maroon), pigment red 190 (red), pigment violet, pigment red 189 (yellow shade red), and pigment red 224. Etc. Examples of the heterocyclic yellow include pigment yellow 117 and pigment yellow 138. Examples of the quinacridone pigment include Pigment Orange 48, Pigment Orange 49, Pigment Red 122, Pigment Red 192, Pigment Red 202, Pigment Red 206, Pigment Red 207, Pigment Red 209, Pigment Violet 19 and Pigment Violet 42. Examples of the thioindigoid pigment include Pigment Red 86, Pigment Red 87, Pigment Red 88, Pigment Red 181, Pigment Red 198, Pigment Violet 36, and Pigment Violet 38. As the black pigment, carbon black produced by various methods can be used.

  The pigment may be dispersed in water using a dispersant such as a surfactant. In this case, as the dispersant, an anionic surfactant and a nonionic surfactant are preferable, and an anionic surfactant is particularly preferable. By using the dispersant, the pigment can be easily dispersed in water, the dispersed particle diameter of the pigment in the toner can be reduced, and a toner having more excellent toner characteristics can be produced. Further, it is possible to remove unnecessary dispersant by the washing step.

  A pigment may be used individually by 1 type and may use 2 or more types together. Moreover, when using 2 or more types of pigments together, the pigment of the same color may be used together, and the pigment of multiple colors may be used together. In the present invention, the content of the pigment can be selected from a wide range according to the required toner characteristics, but is 0.1 to 20% by weight with respect to 100% by weight of the self-dispersing binder resin. It is preferable that it is 0.1 to 15 weight%. When the amount is less than 0.1% by weight, the image density of the formed image is unlikely to be excellent, and when the amount exceeds 20% by weight, it is difficult to ensure the dispersibility of the pigment in the formed image.

(Wax fine particles)
In the present invention, wax fine particles that may be one of the toner components may be included. As the fine particles, known waxes can be used. For example, natural waxes such as carnauba wax and rice wax, polypropylene waxes, polyethylene waxes, synthetic waxes such as Fischer and Lopush wax, and coal-based waxes such as montan wax. , Alcohol waxes and ester waxes. One type of wax may be used alone, or two or more types may be used in combination. The wax fine particles are mixed with the liquid mixture in the mixed liquid preparation step S1. At this time, the wax fine particle aqueous dispersion prepared by previously mixing and emulsifying the wax in water or the encapsulated wax in which the surface of the wax is encapsulated with a resin. Is preferably mixed in the mixed solution. For this reason, inclusion of encapsulated wax is preferable in that the spent on the carrier can be improved because the wax is not exposed on the toner surface in the toner of the production method in which the resin layer is not provided on the toner surface. When the toner component contains a wax, the content thereof is preferably 0.5 to 20% by weight, more preferably 1 to 10% by weight with respect to 100% by weight of the self-dispersing binder resin.

(Additive)
In the present invention, in addition to the above-described toner components, additives generally added to the toner as necessary, for example, a charge control agent and a release agent may be added in an appropriate amount to the dried toner after the washing step. Good.
Further, the toner particles may be surface-modified by adding an external additive to the dried toner after the washing step. As the external additive, known external additives can be used, and examples thereof include water-dispersible inorganic particles such as silica and titanium oxide. These inorganic particles have an average particle diameter of 1 μm or less, preferably 0.01 to 0.8 μm, and one or more kinds can be used in combination. Furthermore, surface modification may be performed by adding a silicone resin or the like to the external additive. The addition amount of the external additive is preferably 1 to 10 parts by weight with respect to 100 parts by weight of the toner particles.

  The toner obtained by the above production method of the present invention preferably has an average particle size of 10 μm or less, more preferably 2 to 9 μm, particularly preferably 3 to 8 μm. When the average particle diameter exceeds 10 μm, the particle size distribution becomes broad in the toner production process, and the chargeability variation is large, which causes the image to be disturbed.

The toner obtained by the production method of the present invention can be used as a one-component developer or a two-component developer. When used as a one-component developer, a carrier is not used, only toner is used, a blade and a fur brush are used, a toner is frictionally charged by a developing sleeve, and the toner is attached onto the sleeve to form an image. .
When used as a two-component developer, toner is used together with a carrier. As the carrier, a known carrier can be used, and examples thereof include a single or composite ferrite composed of iron, copper, zinc, nickel, cobalt, manganese, magnesium and chromium, and a carrier core particle whose surface is coated with a coating substance. . As the coating material, known materials can be used. For example, polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicone resin, polyester resin, metal compound of ditertiary butylsalicylic acid, styrene resin, acrylic resin , Polyacid, polyvinyllar, nigrosine, aminoacrylate resin, basic dye, basic dye lake, silica fine powder, alumina fine powder, and the like, which are preferably selected according to the toner component. Moreover, a coating substance may be used individually by 1 type, and may be used in combination of 2 or more type. The average particle size of the carrier is preferably 10 to 100 μm, more preferably 20 to 80 μm.

[Description of flocculant]
As the aggregating agent used in the agglomerate forming step in the toner production method of the present invention, known ones can be used, for example, electrolytes, organic substances having ions opposite to the pigments, and the like can be used. As described above, since the self-dispersing binder resin and the pigment preferably have an ionic group and / or an ionizable group on the surface, the self-dispersing binder resin and the pigment are ionized. Polyvalent metal salts capable of binding are preferred. Further, magnesium sulfate and aluminum sulfate, which are easily dissolved in water so as to be easily washed with pure water, are more preferable. Among these, magnesium sulfate is particularly preferable. The reason for this is that the magnesium salt has a ionic valence of 2 and, when used as an aggregating agent, compared to a trivalent aluminum salt, the agglomeration rate is slow and is optimal for controlling the particle size. . Further, as the flocculant, an organic flocculant such as dimethylaminoethyl (2,2 dimethylol) propionate can be used.
The amount of the flocculant used is 0.5 to 20 parts by weight, preferably 0.5 to 18 parts by weight, and more preferably 1.0 to 18 parts by weight with respect to 100 parts by weight of the toner component. If the amount of the flocculant used is less than 0.5 parts by weight, no aggregation occurs and particles cannot be formed. If the amount exceeds 20 parts by weight, the aggregated particles become too large.

[Description of pure water]
The pure water used in the cleaning step in the toner production method of the present invention preferably has an electrical conductivity of 20 μS / cm or less. Such pure water can be obtained by a known method such as an activated carbon method, an ion exchange method, a distillation method, or a reverse osmosis method, and a plurality of methods may be combined. The temperature of pure water at the time of washing is preferably not higher than the lowest glass transition temperature of the self-dispersing binder resin from the viewpoint of reaggregation.

[Description of agitator]
In the agglomerate forming step in the toner production method of the present invention, it is preferable to use a stirrer for stirring the mixture. As the stirrer, known emulsifiers and dispersers can be used, but the toner component and the aqueous medium can be received batchwise or continuously, have a heating means, and the toner component and the aqueous medium are heated. An apparatus capable of producing toner which is binder resin particles containing a pigment by mixing and discharging the toner in a batch type or a continuous type is preferable. In addition, the emulsifier and the disperser can impart a shearing force to the mixture of the toner and the aqueous medium, which makes it easier to form the formed aggregate into particles having a uniform particle size and shape. This is preferable. Further, the emulsifier and the disperser preferably have at least one of a stirring unit and a rotating unit, and can mix the toner and the aqueous medium under stirring or rotation. In the emulsifier and the disperser, the mixing container for mixing the toner and the aqueous medium preferably has a heat retaining means.
Specifically, for example, Ultra Thalax (trade name: manufactured by IKA Japan Co., Ltd.), Polytron homogenizer (trade name: manufactured by Kinematica Co., Ltd.) and TK Auto Homo Mixer (trade name: manufactured by Special Machine Industries Co., Ltd.) Batch type emulsifiers such as Max Blend (manufactured by Sumitomo Heavy Industries, Ltd.), Ebara Milder (trade name: manufactured by Ebara Manufacturing Co., Ltd.), TK Pipeline Homo Mixer (trade name: manufactured by Special Machine Industries Co., Ltd.) ), TK homomic line flow (trade name: manufactured by Special Machine Engineering Co., Ltd.), Philmix (trade name: manufactured by Special Machine Engineering Co., Ltd.), colloid mill (trade name: manufactured by Shinko Pantech Co., Ltd.) ), Thrasher (trade name: manufactured by Mitsui Miike Chemicals Co., Ltd.), Trigonal wet milling machine (trade name: manufactured by Mitsui Miike Chemicals Co., Ltd.), Cavitron (trade name: manufactured by Eurotech Co., Ltd.) and Continuous emulsifiers such as Fine Flow Mill (trade name: manufactured by Taiheiyo Kiko Co., Ltd.), Claremix (trade name: manufactured by M Technique Co., Ltd.), and Fillmix (trade name: manufactured by Tokushu Kika Kogyo Co., Ltd.) ) And the like.

  EXAMPLES Examples and comparative examples of the present invention will be specifically described below, but the present invention is not limited to these examples unless it exceeds the gist.

[Synthesis of copolymerized polyester resin used as self-dispersing binder resin particles]
(Copolymerized polyester resin 1)
In an autoclave equipped with a thermometer and a stirrer, 137 parts by weight of dimethyl terephthalate, 55 parts by weight of dimethyl isophthalate, 68 parts by weight of ethylene glycol, 175 parts by weight of bisphenol A ethylene oxide adduct (average molecular weight 350) and tetrabutoxy titanate as a catalyst 0.1 part by weight was charged, and the ester exchange reaction was performed by heating at 150 to 220 ° C. for 180 minutes, and then the temperature was raised to 240 ° C. Then, the pressure of the reaction system was gradually reduced to 10 mmHg after 30 minutes, The reaction was continued for a minute. Thereafter, the inside of the autoclave was replaced with nitrogen gas to obtain atmospheric pressure. While maintaining the temperature at 200 ° C., 2 parts by weight of trimellitic anhydride was added and reacted for 70 minutes to obtain a copolyester resin 1.
It was 15 KOHmg when the acid value of the obtained copolyester resin 1 was measured.

(Copolymerized polyester resin 2)
In an autoclave equipped with a thermometer and a stirrer, 38 parts by weight of 1,5-naphthalenedicarboxylic acid methyl ester, 96 parts by weight of dimethyl terephthalate, 58 parts by weight of dimethyl isophthalate, 136 parts by weight of ethylene glycol and tetrabutoxy titanate 0 as a catalyst .1 part by weight was charged and transesterified by heating at 150 to 220 ° C. for 180 minutes. Next, after the temperature was raised to 240 ° C., the pressure in the reaction system was gradually reduced to 30 mm after 30 minutes, and the reaction was continued for 70 minutes. Thereafter, the inside of the autoclave was replaced with nitrogen gas to obtain atmospheric pressure. While maintaining the temperature at 200 ° C., 10 parts by weight of trimellitic anhydride was added and reacted for 70 minutes to obtain a copolyester resin 2.
The acid value of the obtained copolyester resin 2 was measured and found to be 14 KOHmg.

(Copolymerized polyester resin 3)
In an autoclave equipped with a thermometer and a stirrer, 112 parts by weight of dimethyl terephthalate, 76 parts by weight of dimethyl isophthalate, 6 parts by weight of 5 sodium sulfodimethyl isophthalate, ethylene glycol 96 parts by weight, 50 parts by weight of propylene glycol, and 0.1 parts by weight of tetrabutoxy titanate were charged and heated at 180 to 230 ° C. for 120 minutes to conduct a transesterification reaction. Next, the temperature of the reaction system was raised to 250 ° C., and the reaction was continued for 60 minutes at a system pressure of 1 to 10 mmHg. As a result, a copolyester resin 3 was obtained.
The acid value of the obtained copolyester resin 3 was measured and found to be 0.1 KOHmg.
Table 1 shows the glass transition temperatures and number average molecular weights of the obtained copolyester resins 1 and 2. The glass transition temperature was determined by DSC (differential scanning calorimeter) measurement, and the number average molecular weight was determined by GPC (gel permeation chromatography) measurement.

[Preparation of water dispersion of copolymerized polyester resin]
(Copolymerized polyester resin water fine dispersion 1)
100 parts by weight of the above copolyester resin 1, 48 parts by weight of butanol, 12 parts by weight of methyl ethyl ketone and 20 parts by weight of isopropanol are put into a four-necked 10 liter separable flask equipped with a thermometer, a condenser and a stirring blade. And dissolved at 70 ° C. with stirring. Further, 270 parts by weight of 1N ammonia aqueous solution was added so as to be equal to the acid value of the copolyester resin 1, and after stirring for 30 minutes while maintaining 70 ° C., 300 parts by weight of 70 ° C. water was added while stirring. A water fine dispersion of the copolyester resin 1 was obtained. Further, the obtained water fine dispersion was put into a distillation flask, and the organic solvent was removed by reducing the pressure with a vacuum pump at a temperature of 70 ° C. Finally, the solid content was adjusted with deionized water to obtain a copolyester resin water fine dispersion 1 having a solid content concentration of 30%, which was finally desolvated. The average particle diameter of this polyester resin water fine dispersion was 0.095 μm.

(Copolymerized polyester resin water fine dispersion 2)
A copolyester resin water fine dispersion 2 was obtained in the same manner as the preparation of the copolyester resin water fine dispersion 1 except that the copolyester 2 was used.
The average particle diameter of this polyester resin water fine dispersion was 0.080 μm.
(Copolymerized polyester resin water fine dispersion 3)
A copolyester resin water fine dispersion 3 was obtained in the same manner as in the preparation of the copolyester resin water fine dispersion 1 except that the copolyester 3 was used. The average particle diameter of the polyester resin water finely dispersed particles was 0.2 μm.

[Preparation of dispersed pigment]
(Pigment aqueous dispersion 1)
50 parts by weight of a cyan pigment (manufactured by BASF: Eupolene Blue 69-1501), 5 parts by weight of an anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen R) and 223 parts by weight of ion-exchanged water are zirconia beads having a diameter of 0.5 mm. For 40 minutes with a planetary ball mill (manufactured by Fritsch), and then put into a homogenizer (manufactured by Polytron, PT3000) and stirred for 20 minutes at room temperature to disperse the pigment, and in addition, an ultrasonic homogenizer (Japan) And a blue pigment aqueous dispersion 1 having an average particle size of 0.10 μm was obtained.
In addition, the measurement of the average particle diameter of the pigment of the pigment aqueous dispersion 1 and the pigment aqueous dispersions 2 to 5 described later was measured with Microtrac UPA-ST150 (manufactured by Nikkiso Co., Ltd.).

(Pigment aqueous dispersion 2)
50 parts by weight of magenta pigment 1 (manufactured by BASF: Eupolen Red 47-9001), 5 parts by weight of an anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen R) and 223 parts by weight of ion-exchanged water are zirconia having a diameter of 0.5 mm. Use beads to disperse for 40 minutes with a planetary ball mill (manufactured by Fritsch), then add to a homogenizer (manufactured by Polytron, PT3000) and stir at room temperature for 20 minutes to disperse the pigment, then add with an ultrasonic homogenizer Dispersion was carried out for 20 minutes to obtain a red pigment aqueous dispersion 2 having an average particle size of 0.09 μm.

(Pigment aqueous dispersion 3)
Zirconia beads having a diameter of 0.5 mm containing 50 parts by weight of a yellow pigment (manufactured by BASF: Eupole Yellow 09-6101), 5 parts by weight of an anionic surfactant (Neogen R, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and 223 parts by weight of ion-exchanged water. And then dispersed in a planetary ball mill (manufactured by Fritsch) for 40 minutes, and then placed in a homogenizer (manufactured by Polytron, PT3000) and stirred at room temperature for 20 minutes to disperse the pigment. In addition, an ultrasonic homogenizer was used for 20 Dispersing for a minute, a yellow pigment aqueous dispersion 3 having an average particle size of 0.08 μm was obtained.

(Pigment aqueous dispersion 4)
Using zirconia beads having a diameter of 0.5 mm, 50 parts by weight of carbon black (manufactured by Cabot, Mogal L), 5 parts by weight of a nonionic surfactant (manufactured by Sanyo Chemical Co., Ltd., Nonipol 400) and 223 parts by weight of ion-exchanged water are used. Carbon black having an average particle size of 0.13 μm is dispersed for 40 minutes with a planetary ball mill (manufactured by Fritsch), then charged into a homogenizer (manufactured by Polytron, PT3000) and stirred at room temperature for 20 minutes to disperse the pigment. A pigment aqueous dispersion 4 was obtained.

[Preparation of aqueous wax fine particle dispersion]
Stainless steel beaker with jacket containing 50 parts by weight of paraffin wax (Nippon Seiwa Co., Ltd., HNP10, melting point 72 ° C.), 5 parts by weight of anionic surfactant (Daiichi Kogyo Seiyaku, Neogen R) and 161 parts by weight of ion-exchanged water. And dispersed for 30 minutes while heating at 95 ° C. with a homogenizer (manufactured by Polytron, PT3000), then transferred to a pressure discharge type homogenizer (manufactured by Nippon Seiki Co., Ltd.) and subjected to a dispersion treatment at 90 ° C. for 20 minutes. An aqueous wax fine particle dispersion having a particle size of 0.4 μm was obtained. The average particle size of the dispersed pigment of wax fine particles was measured with Microtrac UPA-ST150 (manufactured by Nikkiso Co., Ltd.).

[Example 1]
(Mixed liquid preparation process)
In the solid content concentration (parts by weight) shown in Table 2, the pigment aqueous dispersion 2 containing dispersed pigment magenta, the copolymerized polyester resin water fine dispersion 1 (85% of 90 parts by weight shown in Table 2) And a wax fine particle aqueous dispersion were mixed to obtain a mixed solution. At this time, it adjusted with the pure water so that the solid content density | concentration containing all might be 10%.

(Aggregate formation process)
While stirring the obtained mixed liquid at 1500 rpm using a Max blend stirrer, 270 parts by weight of a 1% by weight magnesium chloride aqueous solution as a flocculant was dropped little by little, and then this mixed liquid was stirred for 1 hour. By doing so, the aggregate which is a toner was formed in the aqueous medium. Next, the remaining polyester resin aqueous fine dispersion 1 (the remaining 15% of 90 parts by weight shown in Table 2) was mixed, and 30 parts by weight of a 1% by weight magnesium chloride aqueous solution was added dropwise little by little. The mixture was stirred for 1 hour. By doing so, the aggregate which is a toner was further formed in the aqueous medium.

(Particle formation process)
The aqueous medium containing the aggregate that has undergone the aggregate formation process is heated to 75 ° C., and stirring is further continued for 30 minutes, and further stirred at 94 ° C. for 20 minutes to uniformize the particle size and shape of the aggregate. It was. At this time, in order to prevent re-aggregation, the pH was adjusted to 10 and 1 part by weight of linear sodium alkylbenzene sulfonate was added.

(Washing process)
Next, the supernatant liquid of the aqueous medium containing aggregates is removed, and the aggregates are washed three times with pure water (supernatant liquid is exchanged three times), then washed with an aqueous HCl solution adjusted to pH 2, and further purified water. After washing three times with a filter, it was filtered and dried using a vacuum dryer to prepare a magenta toner.
In addition, the pure water used for washing | cleaning used the 0.5 micro S / cm water adjusted from the tap water using the ultrapure water manufacturing apparatus (ADVANTEC company_made: Ultra Pure Water System CPW-102). The pH and conductivity of water were measured using a Lacom tester (manufactured by Inoue Seieido: EC-PHCON10).

[Example 2]
The same procedure as in Example 1 was conducted except that a mixed solution was prepared using pigment aqueous dispersion 1 containing dispersed pigment cyan and copolymer polyester resin aqueous fine dispersion 2 at a solid content concentration (parts by weight) shown in Table 2. A toner was manufactured to obtain a cyan toner of Example 2.

[Example 3]
The same procedure as in Example 1 was conducted, except that a mixed liquid was prepared using pigment aqueous dispersion 3 containing dispersed pigment yellow and copolymer polyester resin aqueous fine dispersion 3 at a solid content concentration (parts by weight) shown in Table 2. A toner was manufactured to obtain a yellow toner of Example 3.

[Example 4]
The same procedure as in Example 1 was conducted except that a mixed liquid was prepared using the pigment aqueous dispersion 4 containing the dispersed pigment black and the copolyester resin water fine dispersion 2 at the solid content concentration (parts by weight) shown in Table 2. A toner was manufactured to obtain a black toner of Example 4.

[Example 5]
A mixed liquid is prepared using the pigment aqueous dispersion 4 containing the dispersed pigment black and the copolyester resin aqueous fine dispersion 2 at a solid content concentration (parts by weight) shown in Table 2. Here, in Example 4, the polyester resin was agglomerated in two portions, but instead of dividing the polyester resin in two times, a predetermined weight part was mixed from the beginning to produce a toner. A toner was obtained. That is, the toner was produced without performing the subsequent aggregation process.

[Comparative Example 1]
The same procedure as in Example 1 was conducted, except that a mixed liquid was prepared using pigment aqueous dispersion 4 containing dispersed pigment black and copolymer polyester resin aqueous fine dispersion 3 at a solid content concentration (parts by weight) shown in Table 2. A toner was manufactured to obtain a black toner of Comparative Example 1.

[Comparative Example 2]
A mixed liquid was prepared using the pigment aqueous dispersion 4 containing the dispersed pigment black and the copolyester resin aqueous fine dispersion 2 at a solid content concentration (parts by weight) shown in Table 2, and the flocculant of Example 1 was changed to Sanisol. A black toner of Comparative Example 2 was obtained in the same manner except that the toner was changed to B50 (manufactured by Kao Corporation) (alkyldimethylbenzylammonium chloride).
[Comparative Example 3]
Aggregates were produced in the same manner as in Example 1. In the subsequent cleaning step, not only the step of cleaning with an aqueous HCl solution of pH 2, but the subsequent steps were performed in the same manner as in Example 1 to prepare a magenta toner.

[Toner preparation]
By mixing (externally adding) 0.7 parts by weight of silica particles having an average primary particle diameter of 20 nm hydrophobized with a silane coupling agent to the toners obtained in Examples 1 to 5 and Comparative Examples 1 and 2, each color. No toner was obtained.

[Preparation of developer]
70 g of each externally added toner prepared as described above for Examples 1 to 5 and Comparative Examples 1 and 2 and 1400 g of a ferrite carrier coated with a thermoplastic resin were mixed in a V-type mixer and developed. An agent was prepared.

[Evaluation methods]
For Examples 1 to 5, each evaluation of average particle diameter, coefficient of variation, average circularity, image density, fog, pigment dispersibility and transfer rate and their overall evaluation are performed by the evaluation methods shown below, and the results are shown. It is shown in Table 3. In Table 3, the following “◯” symbols mean that the evaluation is very excellent in each item.

(Average particle size and coefficient of variation)
The average particle size and variation coefficient of the toner particles were measured using Coulter Multisizer II (manufactured by Coulter Inc.), and evaluated based on the following criteria based on the variation coefficient. The number of measured particles was 50,000 counts, and the aperture diameter was 100 μm. In addition, the unit of the average particle diameter in Table 3 is μm.
○: The coefficient of variation is 40 or less.

(Average circularity)
The average circularity of the toner particles was measured using a flow particle image analyzer (manufactured by Toa Medical Electronics Co., Ltd .: FPIA-2000). The average circularity is defined by the following formula in the projected image of the particles detected by the flow type particle image analyzer, and has a value of 1 or less.
Average circularity = (perimeter of a circle having the same area as the projected image) / (perimeter of the projected image)

(Image density)
The image density was evaluated by measuring the optical density of the evaluation image using a spectrocolorimetric densitometer (manufactured by Nippon Planographic Printing Equipment Co., Ltd .: X-Rite 938) and based on the optical density based on the following criteria. The evaluation image was obtained by attaching toner particles on full-color exclusive paper (Sharp: PP106A4C) using the above developer in a modified device of a developing device of a digital full-color multifunction peripheral (Sharp: AR-C150). The amount was adjusted to 0.6 mg / cm ² and printed, and an external fixing machine was used.
○: Optical density is 1.2 or more.

(Fog)
The fog was evaluated as follows. In the case of black toner, the whiteness of A4 size full color paper (manufactured by Sharp Corporation: PP106A4C) is measured in advance using a whiteness meter (manufactured by Nippon Denshoku Industries Co., Ltd .: Z-Σ90 COLOR MEASURING SYSTEM). Is the first measured value W1. Next, three originals including a white circle with a diameter of 55 mm are copied, and the whiteness of the obtained white portion is measured with a whiteness meter, and this value is set as a second measurement value W2. The fog density W (%) was calculated from the following formula, and evaluated according to the following criteria based on the fog density.
W = {100 × (W1-W2) / W1}
○: The fog density W is 2.0% or less.

(Environmental assessment)
A predetermined amount of the developer is put into a developing tank and stored for one day in each environment ((a) temperature 5 ° C., humidity 10%, (b) temperature 35 ° C., humidity 80%). Rotate at the same rotation speed for 2 minutes, measure the charge amount of the toner at that time, and based on the relative ratio of the charge amount of the toner under the high temperature and high humidity condition of (b) to the low temperature and low humidity condition of (a) Evaluation was made according to the following criteria.
○: Change rate is within 60%.

(Transfer rate)
The transfer rate T (%) is obtained by measuring the toner particle weight Mp on the paper surface on which a predetermined chart is copied and the toner particle weight Md remaining on the photosensitive member, and is calculated from the following formula. %) Based on the following criteria.
T = {Mp / (Md + Mp) × 100}
○: Transfer rate T is 90% or more.

As apparent from Table 3, according to the present invention (Examples 1 to 5), it was found that a toner having excellent toner characteristics such as particle size distribution, image density, fog, environmental evaluation and transfer rate can be produced.
In addition, when Examples 4 and 5 were compared, the toner with a resin layer on the particle surface was slightly more stable in evaluating the charging property of the toner due to the environment.
Further, according to Example 4 and Comparative Example 1, it can be seen that the carboxylic acid self-dispersing polyester and the sulfonic acid group-containing self-dispersing polyester are superior in the environmental characteristics of the toner using the carboxylic acid polyester.
Further, according to Example 4 and Comparative Example 2, it can be seen that the use of a polyvalent metal salt as an aggregating agent can produce a toner more stably.
Furthermore, according to Example 1 and Comparative Example 3, it was found that the environmental characteristics became unstable because the cleaning process was not performed with water having a pH of 6 or less.

  The electrostatic image developing toner of the present invention can be suitably used for a copying machine or a printer.

FIG. 3 is a flowchart showing a method for producing an electrostatic image developing toner of the present invention.

Claims (11)

A pigment aqueous dispersion dispersed by using a dispersing agent consisting of anionic surfactant or a nonionic surfactant, a binder resin particle aqueous dispersion containing self-dispersible polyester binder resin particles, wherein A mixed liquid preparation step of preparing a mixed liquid by mixing a wax fine particle aqueous dispersion containing natural and / or synthetic wax fine particles to be bound to the self-dispersing polyester binder resin particles ;
An agglomerate forming step of forming an agglomerate in which at least a dispersed pigment is bound to the self-dispersing binder resin particles by adding a polyvalent metal salt as an aggregating agent while stirring the mixed liquid ;
A particle forming step of heating the mixed liquid containing the aggregate to make the particle diameter and shape of the aggregate uniform; and
Washing the agglomerates with pure water, followed by washing with water of pH 6 or less, then washing with pure water, and then drying;
The self-dispersing polyester binder resin particles are synthesized from a polyhydric carboxylic acid containing a polycarboxylic acid having at least three carboxyl groups and a polyhydric alcohol, and have a carboxylic acid as a hydrophilic group in the main chain. Is,
The method for producing a toner for developing electrostatically charged images , wherein the polyvalent carboxylic acid having at least three carboxyl groups is introduced into a reaction system at the end of polymerization of the acid and the alcohol . 2. The electrostatic charge image development according to claim 1, wherein in the aggregate formation step, the aqueous dispersion of binder resin particles containing self-dispersing polyester binder resin particles is further mixed while stirring the mixed liquid containing the aggregate. Of manufacturing toner. The method for producing a toner for developing an electrostatic image according to claim 1 or 2, wherein the aggregate has an average particle size of 10 µm or less. The method for producing a toner for developing an electrostatic image according to claim 1, wherein the self-dispersing polyester binder resin particles have an average particle size of 0.2 μm or less. The method for producing a toner for developing an electrostatic image according to any one of claims 1 to 4, wherein the metal of the polyvalent metal salt is a magnesium or aluminum metal salt. The method for producing a toner for developing an electrostatic charge image according to any one of claims 1 to 5 , wherein in the aggregate formation step, an aqueous solution containing an aggregating agent is mixed while stirring the mixed liquid by a mechanical shearing force. Toner for electrostatic charge image development, characterized in that it is manufactured by the manufacturing method of the electrostatic charge image developing toner according to any one of claims 1-6. 8. The electrostatic image developing toner according to claim 7 , wherein one or more kinds of inorganic particles having an average particle diameter of 1 [mu] m or less are bound to the surface of the toner particles. An electrostatic charge image developer comprising the electrostatic charge image developing toner according to claim 7 and a carrier. An electrostatic latent image is formed on the photoreceptor, and the electrostatic latent image on the photoreceptor is developed using the electrostatically charged image developer according to claim 9 to form a toner image, and the toner image is recorded on the recording medium. An image forming method comprising a step of transferring and fixing to an image. A formed image produced by the image forming method according to claim 10 .

Images