JP4670473B2 - Method for producing resin particle dispersion for electrostatic image developing toner, electrostatic image developing toner and method for producing the same - Google Patents

Description

  The present invention relates to an electrostatic charge image developing toner used when developing an electrostatic latent image formed by an electrophotographic method or an electrostatic recording method with a developer, a manufacturing method thereof, and resin particles used as a raw material thereof The present invention relates to a method for producing a dispersion.

  A method of visualizing image information through an electrostatic charge image such as electrophotography is currently used in various fields. In the electrophotographic method, an electrostatic image is formed on the photoreceptor by charging and exposure processes, the electrostatic latent image is developed with a developer containing toner, and visualized through a transfer and fixing process. The developer used here includes a two-component developer composed of a toner and a carrier and a one-component developer using a magnetic toner or a non-magnetic toner alone. The toner is usually produced by using a thermoplastic resin as a pigment. In addition, a kneading and pulverizing method is used in which melt-kneading is performed together with a release agent such as a charge control agent and wax, and the mixture is cooled, finely pulverized, and further classified. In these toners, if necessary, inorganic or organic particles for improving fluidity and cleaning properties may be added to the toner particle surfaces.

  In recent years, copiers, printers using color electrophotography, and multi-function machines such as those and facsimiles have been widely used. However, in order to achieve moderate gloss in color image reproduction and transparency to obtain an excellent OHP image, It is generally difficult to use a release agent such as wax. For this reason, a large amount of oil is applied to the fixing roll to assist in peeling, so that it is difficult to add a copy image containing OHP, and it is difficult to add to the image with a pen or the like, and non-uniform glossiness is generated. There are also many. In normal black-and-white copying, commonly used waxes such as polyethylene, polypropylene, and paraffin are more difficult to use because they impair OHP transparency.

  For example, even if the transparency is sacrificed, it is difficult to suppress the toner exposure to the surface by the conventional toner production method by the kneading and pulverization method. Problems such as deterioration of the image quality and filming on the developing machine and the photoreceptor.

  As a fundamental improvement method for these problems, an oil phase composed of a monomer and a colorant as a resin raw material is dispersed in an aqueous phase and directly polymerized into a toner. There has been proposed a production method by a polymerization method in which the exposure to the surface is controlled by inclusion.

  In addition, Patent Documents 1 and 2 propose a toner manufacturing method using an emulsion polymerization aggregation method as means for enabling intentional control of the toner shape and surface structure. In general, a resin particle dispersion is prepared by emulsion polymerization or the like, while a colorant dispersion in which a colorant is dispersed in a solvent is prepared and mixed to form an aggregate corresponding to the toner particle diameter and heated. Is a method for producing toner by fusing together.

  These manufacturing methods not only realize the inclusion of the wax, but also facilitate the reduction of the toner diameter, and enable higher resolution and clearer image reproduction.

  In order to provide high-quality images in the electrophotographic process as described above and maintain stable performance of the toner under various mechanical stresses, pigment, release agent selection, amount optimization, surface application In addition to suppressing the exposure of the mold release agent, it is extremely important to improve the mold release and suppress hot offset in the absence of gloss and fixing oil by optimizing the resin characteristics.

  On the other hand, in order to reduce energy consumption, a technology capable of fixing at a lower temperature is desired. Particularly in recent years, in order to save energy, it is desirable to stop energization of the fixing machine except during use. ing. Accordingly, the temperature of the fixing device needs to be energized and instantaneously raised to the operating temperature. For this purpose, it is desirable to make the heat capacity of the fixing machine as small as possible. In this case, however, the temperature fluctuation of the fixing machine tends to be larger than before. That is, the overshoot of the temperature after the start of energization increases, and on the other hand, the temperature drop due to paper passing also increases. In addition, when paper having a width smaller than the width of the fixing device is continuously passed, the temperature difference between the paper passing portion and the non-paper passing portion also increases. In particular, when used in high-speed copying machines and printers, the power supply capacity tends to be insufficient, and there is a strong tendency to cause the above phenomenon. Therefore, there is a strong demand for a toner for electrophotography having a wide fixing latitude, which is fixed at a low temperature and does not cause an offset to a higher temperature region.

  As a means for lowering the fixing temperature of the toner, it is known to use a polycondensation type crystalline resin showing a sharp melting behavior with respect to the temperature as the binder resin constituting the toner. In many cases, the melt kneading and pulverization method is difficult to pulverize and generally cannot be used.

  Furthermore, the polymerization of the polycondensation type resin requires a reaction that takes 10 hours or more under stirring at a high temperature exceeding 200 ° C. under high power and under a high vacuum, resulting in a large amount of energy consumption. For this reason, enormous capital investment is often required to obtain durability of the reaction equipment.

  In addition, when the toner is prepared by the emulsion polymerization aggregation method as described above, after the polycondensation type crystalline resin is polymerized, it is emulsified in an aqueous medium and aggregated with a pigment or wax in a latex state. Can be fused and united.

  However, when the polycondensation resin is emulsified, it is emulsified by high shear under high heat exceeding 150 ° C., or the solvent is removed after the solution which has been dissolved in the solvent and reduced in viscosity is dispersed in an aqueous medium. It requires a very inefficient and energy consuming process.

  In addition, it is difficult to avoid problems such as hydrolysis during emulsification in an aqueous medium, and indeterminate factors are inevitable in material design.

  These problems are conspicuous in the crystalline resin, but are not limited to this, and the same is true for the amorphous resin.

For example, in Patent Document 3, a toner raw material containing at least a polyester resin is heated and melted to produce a melt of the toner raw material, and then the resin fine particles are obtained by emulsifying the melt in an aqueous medium. There has been proposed a method for producing a toner for developing an electrostatic charge image, characterized in that an aggregate of the resin fine particles is produced by aggregating and then fusing the resin fine particles.
Here, a conventional polycondensation catalyst such as tetrabutyl titanate is used, and monomers include trimellitic anhydride (TMA) as polyvalent carboxylic acid, terephthalic acid (TPA) as divalent carboxylic acid, and isophthalic acid. (IPA), polyoxypropylene (2.4) -2,2-bis (4-hydroxyphenyl) propane (BPA-PO), polyoxyethylene (2.4) -2,2-bis (aromatic diol) 4-Hydroxyphenyl) propane (BPA-EO), ethylene glycol (EG) as an aliphatic diol, etc., reacted at 220 ° C. for 15 hours under normal pressure nitrogen flow, then reduced in pressure and reacted at 10 mmHg. A polyester having a weight average molecular weight of about 5,000 to 90,000 is prepared, and then melt-kneaded with a colorant, wax and the like. Thereafter, the melt-kneaded product MB1 is heated to 190 ° C. and charged into Cavitron CD1010 (Eurotech Co., Ltd.), which is a dispersion emulsifier, and 0.5 wt% diluted ammonia water is added and heated to 160 ° C. with a heat exchanger. A method is used in which the dispersion slurry is fed to the Cavitron at a speed of 1 L / min, and the dispersed slurry is cooled to 60 ° C. and taken out.
In order to make a toner, this dispersion is further used for agglomeration, fusion, washing and drying. However, in such a method, energy during resin production and resin emulsification is enormous. It is clear that this is not possible.
In addition, such emulsification dispersion under high energy conditions tends to lead to decomposition of the resin, etc., and it is difficult to realize uneven distribution of the composition and uniformity of the particle size distribution of the resin particles in the dispersion liquid. Problems arise, and toners using these materials tend to cause problems not only in initial image quality, but also in image quality stability during continuous printing.

Japanese Patent Laid-Open No. 63-282275 JP-A-6-250439 JP 2002-351140 A

  Accordingly, an object of the present invention is to solve the conventional problems and achieve the following object. That is, the present invention is to provide a resin particle dispersion for an electrostatic charge image developing toner in which resin particles are stably emulsified and dispersed in an aqueous medium with low energy. Another object of the present invention is to provide an electrostatic charge image developing toner sufficiently satisfying toner characteristics, a method for producing the same, an electrostatic charge image developer, and an image forming method using these.

The above problems are solved by means <1> to <5> shown below.
<1> A step of obtaining a polycondensation resin by polycondensing a polycondensable monomer using an acid having a surface-active effect as a polycondensation catalyst, and dispersing the polycondensation resin in an aqueous medium to which a base is added. A process for producing a resin particle dispersion for electrostatic charge image developing toner, comprising a step of obtaining a resin particle dispersion having a median diameter of the resin particles of 0.05 μm or more and 2.0 μm or less,
<2> A method for producing an electrostatic charge image developing toner comprising a step of aggregating the resin particles in a dispersion containing at least a resin particle dispersion to obtain aggregated particles, and a step of heating and aggregating the aggregated particles A method for producing an electrostatic image developing toner, wherein the resin particle dispersion is a resin particle dispersion for an electrostatic image developing toner obtained by the production method according to the above <1>.
<3> An electrostatic image developing toner obtained by the method for producing an electrostatic image developing toner according to <2> above,
<4> An electrostatic charge image developer comprising the electrostatic charge image developing toner according to <3> and a carrier,
<5> A latent image forming step for forming an electrostatic latent image on the surface of the latent image holding member, and a toner image is formed by developing the electrostatic latent image formed on the surface of the latent image holding member with a developer containing toner. An image development process, a transfer process for transferring the toner image formed on the surface of the latent image carrier to the surface of the transfer target, and a fixing process for thermally fixing the toner image transferred to the surface of the transfer target. An image forming method comprising using the electrostatic image developing toner according to <3> as the toner or the electrostatic image developer according to <4> as the developer. .

  According to the present invention, it is possible to provide a resin particle dispersion for an electrostatic charge image developing toner in which resin particles are stably emulsified and dispersed in an aqueous medium with low energy. Further, by utilizing this, it is possible to provide an electrostatic charge image developing toner sufficiently satisfying the toner characteristics, a method for producing the same, an electrostatic charge image developer, and an image forming method using them.

  Hereinafter, the present invention will be described in detail.

(Dispersion for electrostatic image developing toner)
The resin particle dispersion for an electrostatic charge image developing toner of the present invention is obtained by dispersing polycondensation resin particles having a median diameter of 0.05 μm or more and 2.0 μm or less in an aqueous medium containing an acid salt having a surface active effect. It is characterized by being.

In such a resin particle dispersion of the present invention, the polycondensable monomer is polycondensed at a low temperature (preferably 150 ° C. or less, more preferably 70 to 150 ° C., more preferably 70 to 140 ° C.), and the low temperature (Preferably 150 ° C. or less, more preferably 70 to 150 ° C., and further preferably 70 to 90 ° C.), polycondensation resin particles can be obtained with low energy and polycondensation in an aqueous medium. As the dispersed state of the resin particles, an isolated state in water is realized, and it is stable for a long time before the aggregation operation using a coagulant for toner formation. Since this makes it possible to form particles, the particle size distribution as a toner is improved, and the composition and structure of each toner are made uniform, so that the toner characteristics are sufficiently satisfied. Toner can be obtained.
As a result, the initial image quality can be maintained as well as a stable image quality even during continuous printing.

Here, the median diameter (center diameter) of the polycondensation resin particles is 0.05 μm or more and 2.0 μm or less, preferably 0.1 μm or more and 1.5 μm or less, more preferably 0.1 μm or more and 1.0 μm or less, Particularly preferably, the thickness is from 0.1 μm to 0.3 μm. When the median diameter is in the above range, the dispersion state of the polycondensation resin particles in the medium in the aqueous medium is stabilized as described above. Therefore, if the median diameter is too small at the time of toner preparation, the agglomeration property at the time of particle formation is deteriorated, free resin particles are likely to be generated, and the viscosity of the system is likely to be increased. It becomes difficult to control. On the other hand, if it is too large, the generation of coarse powder is likely to occur, the particle size distribution is deteriorated, and the release agent such as wax is easily released, so that the releasability at the time of fixing and the offset generation temperature are lowered.
The median diameter of the polycondensation resin particles can be measured, for example, with a laser diffraction particle size distribution analyzer (LA-920, manufactured by Horiba, Ltd.).

  In addition, the polycondensation resin particles are suitable not only for their median diameter but also for generation of ultrafine powder and ultracoarse powder, and the ratio of polycondensation resin particles having a particle diameter of 0.03 μm or less or 5.0 μm or more. (Hereinafter also referred to as large / small particle total ratio) is preferably 10% or less of the total, more preferably 5% or less. This ratio can be obtained by plotting the relationship between the particle diameter and the frequency integration in the measurement result in LA-920 and obtaining from the frequency integration amount of 0.03 μm or less or 5.0 μm or more.

(Method for producing dispersion for electrostatic charge image developing toner)
The method for producing a resin particle dispersion for an electrostatic charge image developing toner of the present invention (hereinafter also simply referred to as a resin particle dispersion of the present invention) uses a polycondensable monomer by using an acid having a surface-active effect as a polycondensation catalyst. A step of obtaining a polycondensation resin by polycondensation of the product, and dispersion of the polycondensation resin in an aqueous medium to which a base is added, wherein the resin particles have a median diameter of 0.05 μm or more and 2.0 μm or less It includes a step of obtaining a liquid.

Hereafter, the manufacturing method of the resin particle dispersion liquid of this invention is demonstrated.
In order to obtain the resin particle dispersion of the present invention, for example, first, a polycondensable monomer and an acid having a surfactant effect are melt-mixed as a target resin raw material, and then heated, stirred, under normal pressure or reduced pressure. It is obtained by mixing with hot water containing a base for neutralizing the catalyst acid in a heated state, and dispersing and emulsifying with a homogenizer or the like. Heating during the polycondensation is preferably 150 ° C. or less, more preferably 70 to 150 ° C., and further preferably 70 to 140 ° C. Within the above range, decomposition of the polycondensation resin and uneven distribution of the composition do not occur, and when the resin particle dispersion is used, the particle size distribution of the resin particles becomes uniform.
At this time, if necessary, other polycondensation catalyst, surfactant and the like can be used in combination.

In the present invention, the base added to the aqueous medium in which the resin particles are dispersed may be any base that neutralizes the acidity of the dispersion. Examples thereof include inorganic bases such as inorganic hydroxides, inorganic carbonates, and ammonia. And organic bases such as amines. Among them, inorganic hydroxides are preferable from the viewpoint of cost and solubility in aqueous media, and sodium hydroxide is particularly preferable.
When the base is added to the aqueous medium, a part or all of the acid having a surface-active effect is neutralized to produce an acid salt having a surface-active effect. The acid salt having a surface active effect may be dissolved in the aqueous medium or may be precipitated in the aqueous medium.
The amount of the base to be added depends on the solubility in an aqueous medium, the pKa of the base, etc., but it is preferable that the amount of the dispersion be maintained from weakly acidic to neutral (pH = 4 to 8). The acid having a surfactant effect is preferably 0.01 to 2 equivalents, more preferably 0.05 to 1 equivalent, and still more preferably 0.1 to 0.8 equivalent.
Examples of the aqueous medium that can be used in the present invention include water such as distilled water and ion-exchanged water, alcohol, and the like. Among these, water such as distilled water and ion exchange water is preferable. These may be used individually by 1 type and may use 2 or more types together.
The pH of the resin particle dispersion of the present invention is preferably 4.0 to 8.0, more preferably 5.0 to 8.0, and 6.0 to 8.0. Further preferred.

The acid having a surface active effect acts as a polycondensation catalyst having an effect at a low temperature (preferably 150 ° C. or less, more preferably 70 to 150 ° C., further preferably 70 to 140 ° C.) during polymerization of the resin, The acid having a surface-active effect and / or a salt thereof acts as a dispersant uniformly mixed in the resin at the time of dispersion emulsification in water, and has a low temperature (preferably 150 ° C. or less, more preferably 70 to 150 ° C., further Preferably, emulsification at 70 to 90 ° C. can be realized.
Conventionally, there are many examples of adding a dispersing agent to the water side during emulsification of the resin in water, but in this case, it is difficult to act on emulsification unless a high temperature is applied so that the resin has a low viscosity. , Emulsification at low temperatures cannot be realized.
In order to improve the emulsifiability of the resin, as disclosed in JP-A-2002-351140, it is possible to give an acid value or make it self-water dispersible when the resin is finally used as a toner. Since the hydrophilicity of the toner is high, it is not practical to cause a decrease in chargeability or a large change in toner chargeability under high temperature, high humidity and low temperature and low humidity.
Since the acid having a surface-active effect used here is a relatively low molecule and has high water solubility, most of it is removed at the time of washing after agglomeration and fusion for toner formation, so that the toner chargeability is improved. Can be minimized.
As temperature at the time of emulsification dispersion, 150 ° C or less is preferred, 100 ° C or less is more preferred, and 90 ° C or less is still more preferred. Within the above range, hydrolysis of the polycondensation resin does not occur, and the charging property and fixing property of the toner are good, which is preferable.

  In order to polycondense a polycondensable monomer at a low temperature of 150 ° C. or lower, or preferably 100 ° C. or lower, a polycondensation catalyst is usually used. Examples of such a polycondensable catalyst having catalytic activity at a low temperature include acids having a surface-active effect, but a rare earth-containing catalyst or a hydrolase can also be used in combination.

An acid having a surface-active effect is a catalyst having a chemical structure composed of a hydrophobic group and a hydrophilic group, an acid structure in which at least a part of the hydrophilic group is composed of protons, and having both an emulsifying function and a catalytic function. is there. Examples of the acid having a surface active effect include alkylbenzene sulfonic acid, alkyl sulfonic acid, alkyl disulfonic acid, alkyl phenol sulfonic acid, alkyl naphthalene sulfonic acid, alkyl tetralin sulfonic acid, alkyl allyl sulfonic acid, petroleum sulfonic acid, alkyl benzimidazole sulfone. Acid, higher alcohol ether sulfonic acid, alkyl diphenyl sulfonic acid, long chain alkyl sulfate, higher alcohol sulfate, higher alcohol ether sulfate, higher fatty acid amide alkylol sulfate, higher fatty acid amide alkylated sulfate, sulfated fat, Sulfosuccinates, various fatty acids, sulfonated higher fatty acids, higher alkyl phosphates, resin acids, resin acid alcohol sulfuric acid, and all these chlorides And the like, may be used in combination of two or more as necessary. Among these, a sulfonic acid having an alkyl group or an aralkyl group, a sulfate ester having an alkyl group or an aralkyl group, or a salt compound thereof is preferable, and the alkyl group or the aralkyl group has 7 to 20 carbon atoms. More preferably. Specifically, dodecylbenzenesulfonic acid, isopropylbenzenesulfonic acid, kerylbenzenesulfonic acid, camphor sulfonic acid, paratoluenesulfonic acid, monobutylphenylphenol sulfate, dibutylphenylphenol sulfate, dodecyl sulfate, naphthenyl alcohol sulfate And naphthenic acid.
The amount of the acid having a surfactant effect that can be used in the present invention is preferably 0.01 to 5% by weight, preferably 0.1 to 3% by weight, based on the total weight of the polycondensable monomer. Is more preferable.

Examples of rare earth-containing catalysts that can be used in combination include scandium (Sc), yttrium (Y), lanthanoid elements such as lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium. (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), etc. In particular, alkylbenzene sulfonates, alkyl sulfates, or those having a triflate structure are effective. Examples of the triflate include X (OSO ₂ CF ₃ ) _{3 in} the structural formula. X is a rare earth element, and among these, scandium (Sc), yttrium (Y), ytterbium (Yb), samarium (Sm), and the like are preferable.
The lanthanoid triflate is described in detail in, for example, Journal of Synthetic Organic Chemistry, Vol. 53, No. 5, p44-54.

  The hydrolase used in combination is not particularly limited as long as it catalyzes an ester synthesis reaction. Examples of the hydrolase include EC (enzyme number) 3.1 group (Maruo, Lipoprotein lipase, etc.) such as carboxyesterase, lipase, phospholipase, acetylesterase, pectinesterase, cholesterol esterase, tannase, monoacylglycerol lipase, lactonase and lipoprotein lipase. Hydrolase, epoxide hydrase, etc. classified into EC 3.2 group that acts on glycosyl compounds such as esterase, glucosidase, galactosidase, glucuronidase, xylosidase, etc. classified in “Enzyme Handbook” supervised by Tamiya (1982). It is classified into EC3.4 group that acts on peptide bonds such as hydrolase, aminopeptidase, chymotrypsin, trypsin, plasmin, subtilisin etc. Hydrolase, mention may be made of hydrolytic enzymes such as classified into EC3.7 group such as furo retinoic hydrolase.

  Among these esterases, the enzyme that hydrolyzes glycerol esters and liberates fatty acids is called lipase, but lipase has high stability in organic solvents, catalyzes ester synthesis reaction in high yield, and can be obtained at a low price. There are advantages such as. Therefore, it is desirable to use lipase also in the manufacturing method of the polyester of this invention from the surface of a yield or cost.

  Lipases of various origins can be used, but preferable examples include Pseudomonas genus, Alcaligenes genus, Achromobacter genus, Candida genus, Aspergillus genus, Rhizopus Examples include lipases obtained from microorganisms such as (Rhizopus) genus and Mucor genus, lipases obtained from plant seeds, lipases obtained from animal tissues, pancreatin, steapsin and the like. Among these, it is desirable to use lipases derived from microorganisms of the genus Pseudomonas, Candida, and Aspergillus.

  These polycondensation catalysts may be used alone or in combination. The amount of the polycondensation catalyst used is preferably 0.01 to 15% by weight, more preferably 0.1 to 10% by weight, based on the total weight of the polycondensable monomer.

  On the other hand, examples of the polycondensation monomer used for polycondensation include polyvalent carboxylic acids, polyols, and polyamines. Examples of the polycondensation resin include polyesters and polyamides. Polyesters obtained by using polycondensation monomers containing polyvalent carboxylic acids and polyols are particularly preferable.

  The polyvalent carboxylic acid is a compound containing two or more carboxyl groups in one molecule. Among these, dicarboxylic acid is a compound containing two carboxyl groups in one molecule. For example, oxalic acid, succinic acid, maleic acid, adipic acid, β-methyladipic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid , Decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, fumaric acid, citraconic acid, diglycolic acid, cyclohexane-3,5-diene-1,2-carboxylic acid, malic acid, citric acid, hexahydroterephthalic acid, Malonic acid, pimelic acid, tartaric acid, mucous acid, phthalic acid, isophthalic acid, terephthalic acid, tetrachlorophthalic acid, chlorophthalic acid, nitrophthalic acid, p-carboxyphenylacetic acid, p-phenylenediacetic acid, m-phenylenediglycolic acid, p-phenylene diglycolic acid, o-phenylene diglycol 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, etc. it can. Examples of the polyvalent carboxylic acid other than dicarboxylic acid include trimellitic acid, trimesic acid, pyromellitic acid, naphthalenetricarboxylic acid, naphthalenetetracarboxylic acid, pyrenetricarboxylic acid, and pyrenetetracarboxylic acid.

  When the polycondensation reaction is carried out in an aqueous medium dispersion, among the polycarboxylic acids, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,11- It is preferable to use undecane dicarboxylic acid, 1,12-dodecanedicarboxylic acid, terephthalic acid, trimellitic acid, pyromellitic acid and the like. Since these polyvalent carboxylic acids are hardly soluble or insoluble in water, the ester synthesis reaction proceeds in a suspension in which the polyvalent carboxylic acid is dispersed in water.

  A polyol is a compound containing two or more hydroxyl groups in one molecule. Among these, diol is a compound containing two hydroxyl groups in one molecule, such as ethylene glycol, propylene glycol, butanediol, diethylene glycol, hexanediol, cyclohexanediol, octanediol, nonanediol, decanediol, dodecanediol, etc. Can be mentioned. Examples of polyols other than diols include glycerin, pentaerythritol, hexamethylol melamine, hexaethylol melamine, tetramethylol benzoguanamine, and tetraethylol benzoguanamine.

In particular, among polyols, ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol. It is preferable to use a diol such as
When the polycondensation reaction is carried out in an aqueous medium dispersion, a diol such as 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol is used. Is preferred. Since these polyols are hardly soluble or insoluble in water, the ester synthesis reaction proceeds in a suspension in which the polyol is dispersed in water.

  In addition, an amorphous resin or a crystalline resin can be easily obtained by combining these polycondensable monomers.

  For example, polyvalent carboxylic acids used to obtain crystalline polyesters and crystalline polyamides include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, peric acid, azelaic acid, sebacic acid, Maleic acid, fumaric acid, citraconic acid, itaconic acid, glutamic acid, n-dodecyl succinic acid, n-dodecenyl succinic acid, isododecyl succinic acid, isododecenyl succinic acid, n-octyl succinic acid, n-octenyl succinic acid, 1 , 9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, and acid anhydrides or acid chlorides thereof.

  Further, for example, as the polyol used for obtaining the crystalline polyester, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1, 4-butenediol, neopentyl glycol, 1,5-pentane glycol, 1,6-hexane glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetra Mention may also be made of methylene glycol, bisphenol A, bisphenol Z, hydrogenated bisphenol A and the like.

  Further, for example, polyamines used for obtaining polyamides include ethylenediamine, diethylenediamine, 1,2-propanediamine, 1,3-propanediamine, 1,4-butanediamine, 1,4-butenediamine, 2 , 2-dimethyl-1,3-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,4-cyclohexanediamine, 1,4-cyclohexanebis (methylamine), and the like.

  Examples of the polyvalent carboxylic acid for obtaining an amorphous polyester include aromatics such as dibasic acids such as phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, malonic acid, and mesaconic acid. Examples thereof include dicarboxylic acids, and these lower esters are not limited thereto. Examples of the trivalent or higher carboxylic acid include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 1,3,5-benzenetricarboxylic acid (trimesic acid), and 1,2,4-naphthalenetricarboxylic acid. , Pyromellitic acid, and anhydrides thereof, sodium 2-sulfoterephthalate, sodium 5-sulfoisophthalate, sodium sulfosuccinate, and lower esters thereof, but are not limited thereto.

  Examples of the polyhydric alcohol for obtaining the non-crystalline polyester preferably include aliphatic, alicyclic, and aromatic polyhydric alcohols. Specific examples include ethylene glycol and 1,5-pentane. Glycol, 1,6-hexane glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A, bisphenol Z, hydrogenated bisphenol A, Examples thereof include ethylene oxide or propylene oxide adducts of bisphenol A (for example, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane), but are not limited thereto.

  The polycondensation resin particles obtained by polycondensation of such a polycondensable monomer are preferably crystalline. In particular, by using a crystalline resin, low-temperature fixing of toner can be easily realized.

  Examples of such crystalline polycondensation resins include polyesters obtained by reacting 1,9-nonanediol and 1,10-decanedicarboxylic acid, or cyclohexanediol and adipic acid, 1,6-hexanediol and sebacin. Polyester obtained by reacting acid, polyester obtained by reacting ethylene glycol and succinic acid, polyester obtained by reacting ethylene glycol and sebacic acid, reacting 1,4-butanediol and succinic acid The polyester obtained by reacting 1,9-nonanediol and azelaic acid can be preferably mentioned. Among these, polyesters obtained by reacting 1,9-nonanediol with 1,10-decanedicarboxylic acid and 1,6-hexanediol with sebacic acid are more preferable.

Moreover, as an amorphous polycondensation resin, polyester obtained by reacting ethylene glycol, polyoxyethylene (2.4) -2,2-bis (4-hydroxyphenyl) propane and terephthalic acid is preferably exemplified. be able to.
Moreover, the ethylene oxide adduct and propylene oxide adduct of bisphenol A as described above can be used by mixing, or terephthalic acid or fumaric acid can be used alone or in combination on the acid side.

  Here, when the polycondensation resin particles are a crystalline resin, the crystal melting point Tm is preferably 50 ° C. or higher and lower than 120 ° C., more preferably in the range of 55 to 90 ° C. When the Tm is in the above range, the cohesive force of the binder resin itself in the high temperature range does not decrease, the peeling property and the hot offset property are good at the time of fixing, and the minimum fixing temperature does not increase, which is preferable. .

Here, for the measurement of the melting point of the crystalline resin, a differential scanning calorimeter (DSC) was used, and the input shown in JIS K-7121 when measuring from room temperature to 150 ° C. at a heating rate of 10 ° C. per minute. It can be determined as the melting peak temperature of the compensated differential scanning calorimetry. The crystalline resin may show a plurality of melting peaks, but in the present invention, the maximum peak is regarded as the melting point.
Moreover, the glass transition point of an amorphous resin means the value measured by the method (DSC method) prescribed | regulated to ASTMD3418-82.

  On the other hand, when the polycondensation resin particles are an amorphous resin, the glass transition point Tg is preferably 50 ° C. or higher and lower than 80 ° C., more preferably in the range of 50 to 65 ° C. When the Tg is in the above range, the cohesive force of the binder resin itself in the high temperature range does not decrease, hot offset hardly occurs during fixing, and the minimum fixing temperature does not increase, which is preferable.

  The weight average molecular weight of the polycondensation resin particles obtained by polycondensation of the polycondensable monomer is suitably in the range of 1,500 to 60,000, preferably 3,000 to 40,000. The above range is preferable because the cohesive force of the binder resin is sufficient, the hot offset property is good, and the minimum fixing temperature does not increase. Further, depending on selection of the carboxylic acid valence and alcohol valence of the monomer, a part of the polycondensation resin may have branching or crosslinking.

  Further, when the polycondensation resin is emulsified and dispersed in an aqueous medium, each of the above materials is emulsified or dispersed in the aqueous medium using, for example, mechanical shear or ultrasonic waves. It is also possible to add a surfactant, a polymer dispersant, an inorganic dispersant and the like to the aqueous medium.

Examples of the surfactant used herein include anionic surfactants such as sulfate ester, sulfonate, and phosphate ester; cationic surfactants such as amine salt type and quaternary ammonium salt type; polyethylene glycol And nonionic surfactants such as polyphenols, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, anionic surfactants and cationic surfactants are preferable. The nonionic surfactant is preferably used in combination with the anionic surfactant or the cationic surfactant. The said surfactant may be used individually by 1 type, and may use 2 or more types together.
Examples of the anionic surfactant include sodium dodecylbenzenesulfonate, sodium alkylnaphthalenesulfonate, sodium arylalkylpolyethersulfonate, 3,3-disulfonediphenylurea-4,4-diazo-bis-amino-8-naphthol. Sodium 6-sulfonate, ortho-carboxybenzene-azo-dimethylaniline, 2,2,5,5-tetramethyl-triphenylmethane-4,4-diazo-bis-β-naphthol-6-sodium sulfonate, Sodium dialkylsulfosuccinate, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, sodium caprate, sodium caprylate, Sodium Ron, potassium stearate, and the like calcium oleate.
Examples of the cationic surfactant include alkylbenzene dimethyl ammonium chloride, alkyl trimethyl ammonium chloride, distearyl ammonium chloride and the like.
Nonionic surfactants include, for example, polyethylene oxide, polypropylene oxide, a combination of polypropylene oxide and polyethylene oxide, esters of polyethylene glycol and higher fatty acids, alkylphenol polyethylene oxide, esters of higher fatty acids and polyethylene glycol, higher fatty acids and polypropylene. Examples include oxide esters and sorbitan esters.
Examples of the polymer dispersant include sodium polycarboxylate and polyvinyl alcohol, and examples of the inorganic dispersant include calcium carbonate. However, these do not limit the present invention.
Further, in order to prevent the Ostripd ripping phenomenon of the monomer emulsion particles in an ordinary aqueous medium, a higher alcohol represented by heptanol or octanol or a higher aliphatic hydrocarbon represented by hexadecane is often added as a stabilizer. It is also possible.

  In addition, when polycondensation resin particles are polycondensed in an aqueous medium, components necessary for normal toner such as a fixing agent such as a colorant and wax, and other charging assistants are mixed in advance in the aqueous medium, and then polycondensed. At the same time, it can be mixed in the polycondensation resin particles.

(Method for producing electrostatic image developing toner)
The method for producing an electrostatic image developing toner of the present invention comprises a step of aggregating the resin particles in a dispersion containing at least a resin particle dispersion to obtain aggregated particles (aggregation step), and heating the aggregated particles. A method for producing an electrostatic charge image developing toner comprising a fusing step (fusing step), wherein the resin particle dispersion is obtained by the method for producing a resin particle dispersion for an electrostatic charge image developing toner of the present invention. It is a resin particle dispersion for image developing toner. Hereinafter, this production method is also referred to as an emulsion polymerization aggregation method.

  In the aggregation step, the polycondensation resin particles in the resin particle dispersion of the present invention are prepared in an aqueous medium, so that they can be used as they are as a resin dispersion, and this resin particle dispersion can be used as needed. Aggregated particles having a toner diameter can be formed by mixing with the colorant particle dispersion and the release agent particle dispersion, adding an aggregating agent, and heteroaggregating these particles. In addition, after forming the first aggregated particles by aggregation in this way, the resin particle dispersion of the present invention or another resin particle dispersion is further added to form the second shell layer on the surface of the first particles. Is also possible. In this illustration, the colorant dispersion is separately adjusted. However, when the colorant is mixed in advance with the polycondensation resin particles, the colorant dispersion is not necessary.

Here, as a flocculant, besides a surfactant, an inorganic salt or a divalent or higher metal salt can be suitably used. In particular, when a metal salt is used, it is preferable in characteristics such as cohesion control and toner chargeability.
Further, for example, a surfactant can be used for emulsion polymerization of resin, dispersion of pigment, dispersion of resin particles, dispersion of release agent, aggregation, stabilization of aggregated particles, and the like. Specifically, sulfate surfactants, sulfonates, phosphates, soaps and other anionic surfactants, amine salts, quaternary ammonium salts and other cationic surfactants, polyethylene glycols, It is also effective to use a nonionic surfactant such as an alkylphenol ethylene oxide adduct system or a polyhydric alcohol system. As a dispersing means, a general method such as a ball mill, sand mill, or dyno mill having a rotary shear homogenizer or a media is used. Can be used

  In addition to the resin particle dispersion of the present invention, addition polymerization resin particle dispersions prepared using conventionally known emulsion polymerization and the like can be used together. The median diameter of the resin particles in the addition polymerization resin particle dispersion that can be used in the present invention is preferably 0.05 μm or more and 2.0 μm or less as in the resin particle dispersion of the present invention.

  Examples of addition polymerization monomers for preparing these resin particle dispersions include styrenes such as styrene and parachlorostyrene, vinyl naphthalene, vinyl chloride, vinyl bromide, vinyl fluoride, vinyl acetate, propion. Vinyl esters such as vinyl acid, vinyl benzoate, vinyl butyrate, such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, n-octyl acrylate, 2-chloroethyl acrylate, Methylene aliphatic carboxylic esters such as phenyl acrylate, methyl α-chloroacrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide such as vinyl methyl ether, vinyl ethyl ether, vinyl Monomers having N-containing polar groups such as vinyl ethers such as isobutyl ether, N-vinyl compounds such as N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone, methacrylic acid and acrylic acid In addition, homopolymers and copolymers of vinyl monomers such as vinyl carboxylic acids such as cinnamic acid and carboxyethyl acrylate, and various waxes can also be used.

  In the case of addition polymerization monomers, emulsion polymerization can be carried out using an ionic surfactant or the like to produce a resin particle dispersion, and in the case of other resins, it is oily and the solubility in water is compared. If it is soluble in a low solvent, the resin is dissolved in those solvents and dispersed in an aqueous medium with a disperser such as a homogenizer together with an ionic surfactant or polymer electrolyte, and then heated or decompressed. Then, the resin particle dispersion can be obtained by evaporating the solvent.

  After the aggregation step, in the fusion step (fusion / unification step), the resin particles are heated to a temperature above the glass transition point or above the melting point to fuse and coalesce the aggregate particles. The toner can be obtained by washing and drying.

  In addition, after completion of the fusion process, desired toner particles are obtained through an arbitrary washing process, solid-liquid separation process, and drying process. In consideration of charging properties, the washing process should be sufficiently washed with ion exchange water. Is desirable. Moreover, although there is no restriction | limiting in particular in a solid-liquid separation process, From the point of productivity, suction filtration, pressure filtration, etc. are suitable. Further, the drying process is not particularly limited, but freeze drying, flash jet drying, fluidized drying, vibration fluidized drying and the like are preferably used from the viewpoint of productivity.

Hereinafter, constituent components of the toner (raw materials used in the production method) will be described.
First, the following can be used as the colorant.
Examples of the black pigment include carbon black, copper oxide, manganese dioxide, aniline black, activated carbon, nonmagnetic ferrite, and magnetite.
Examples of yellow pigments include yellow lead, zinc yellow, yellow iron oxide, cadmium yellow, chrome yellow, hansa yellow, hansa yellow 10G, benzidine yellow G, benzidine yellow GR, selenium yellow, quinoline yellow, permanent yellow NCG, and the like. be able to.
Examples of the orange pigment include red yellow lead, molybdenum orange, permanent orange GTR, pyrazolone orange, vulcan orange, benzidine orange G, indanthrene brilliant orange RK, and indanthrene brilliant orange GK.
Red pigments include Bengala, cadmium red, red lead, mercury sulfide, watch young red, permanent red 4R, risor red, brilliantamine 3B, brilliantamine 6B, dapon oil red, pyrazolone red, rhodamine B rake, lake red C , Rose Bengal, Eoxin Red, Alizarin Lake and the like.
Blue pigments include bitumen, cobalt blue, alkali blue rake, Victoria blue rake, fast sky blue, induslen blue BC, aniline blue, ultramarine blue, calco oil blue, methylene blue chloride, phthalocyanine blue, phthalocyanine green, malachite green oxare. The rate etc. can be mentioned.
Examples of purple pigments include manganese purple, fast violet B, and methyl violet lake.
Examples of the green pigment include chromium oxide, chromium green, pigment green, malachite green lake, final yellow green G, and the like.
Examples of white pigments include zinc white, titanium oxide, antimony white, and zinc sulfide.
Examples of extender pigments include barite powder, barium carbonate, clay, silica, white carbon, talc, and alumina white.
Examples of the dye include various dyes such as basic, acidic, dispersion, and direct dyes, such as nigrosine, methylene blue, rose bengal, quinoline yellow, and ultramarine blue.

  These colorants are used alone or in combination. With respect to these colorants, for example, a dispersion of colorant particles can be prepared using a media type dispersing machine such as a rotary shearing homogenizer, a ball mill, a sand mill, or an attritor, or a high-pressure opposed collision type dispersing machine. Further, these colorants can be dispersed in an aqueous system by a homogenizer using a polar surfactant.

  The colorant is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP permeability, and dispersibility in the toner.

  The colorant can be added in the range of 4 to 15% by weight with respect to the total weight of the toner constituting solids. When using a magnetic material as a black colorant, 12 to 240% by weight can be added unlike other colorants.

  The blending amount of the colorant is a necessary amount for securing the color developability at the time of fixing. Further, the center diameter (median diameter) of the colorant particles in the toner is preferably 100 to 330 nm, and OHP transparency and color developability can be ensured within the above range.

  The center diameter (median diameter) of the colorant particles was measured, for example, with a laser diffraction particle size distribution measuring apparatus (LA-920, manufactured by Horiba, Ltd.).

  Further, when used as a magnetic toner, magnetic powder may be contained. Specifically, a material that is magnetized in a magnetic field is used, but a ferromagnetic powder such as iron, cobalt, or nickel, or a compound such as ferrite or magnetite is used. When obtaining toner in the aqueous phase, it is necessary to pay attention to the aqueous phase migration of the magnetic material, and it is preferable to modify the surface of the magnetic material in advance, for example, to perform a hydrophobic treatment or the like.

  In addition, magnetic materials such as ferrite, magnetite, reduced iron, cobalt, nickel, manganese and other metals, alloys, and compounds containing these metals are used as internal additives, and quaternary ammonium salt compounds, nigrosine as charge control agents. Various charge control agents, such as dyes consisting of complexes of aluminum compounds, aluminum, iron, chromium, and triphenylmethane pigments, can be used, but the ionic strength that affects the aggregation and temporary stability From the viewpoints of control of wastewater and reduction of wastewater contamination, materials that are difficult to dissolve in water are suitable.

Specific examples of the release agent include, for example, various ester waxes, low molecular weight polyolefins such as polyethylene, polypropylene, and polybutene, silicones that show a softening point by heating, oleic acid amide, erucic acid amide, ricinoleic acid amide, stearic acid Fatty acid amides such as amides, plant waxes such as carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil, animal waxes such as beeswax, montan wax, ozokerite, ceresin, paraffin Examples thereof include mineral-based and petroleum-based waxes such as wax, microcrystalline wax, microcrystalline wax, Fischer-Tropsch wax, and modified products thereof.
It is preferable that these waxes are hardly dissolved in a solvent such as toluene near room temperature or very small even if dissolved.

  These waxes are dispersed in an aqueous medium together with a polymer electrolyte such as an ionic surfactant, polymer acid or polymer base, heated above the melting point, and have a strong shearing ability and pressure discharge type. It can be dispersed in the form of particles with a disperser (Gorin homogenizer, manufactured by Gorin Co., Ltd.) to produce a dispersion of particles of 1 μm or less.

  It is desirable to add the release agent in the range of 5 to 25% by weight with respect to the total weight of the toner constituting solids, in order to ensure the peelability of the fixed image in the oilless fixing system.

  In addition, the particle diameter of the release agent particle dispersion was measured, for example, with a laser diffraction particle size distribution analyzer (LA-920, manufactured by Horiba, Ltd.). In addition, when using a release agent, after the resin particles, colorant particles, and release agent particles are aggregated, it is possible to add resin particle dispersion to adhere the resin particles to the surface of the aggregated particles. From the viewpoint of securing the property

The cumulative volume average particle diameter D ₅₀ of the toner obtained by the method for producing an electrostatic charge image developing toner of the present invention is preferably in the range of 3.0 to 9.0 μm, more preferably in the range of 3.0 to 5.0 μm. is there. Within the above range, the adhesion is not high, the developability is good, and the image resolution is also good, which is preferable.

  Further, the volume average particle size distribution index GSDv of the obtained toner is preferably 1.30 or less. It is preferable that GSDv is 1.30 or less because resolution is good and image defects such as toner scattering and fogging hardly occur.

Here, the cumulative volume average particle diameter D ₅₀ and the average particle size distribution index are, for example, the particle size distribution measured by a measuring instrument such as Coulter Counter TAII (manufactured by Nikka Kisha Co., Ltd.), Multisizer II (manufactured by Nikka Kisha Co., Ltd.). The particle size range (channel) divided based on the volume and number are cumulative distributions starting from the small diameter side, and the particle size that is 16% cumulative is the volume D _16v , the number D _16P , and the particle that is 50% cumulative The diameter is _defined as a volume D _50v and a number D _50P , and the particle diameter at a cumulative 84% is defined as a volume D _84v and a number D _84P . Using these, the volume average particle size distribution index (GSDv) is calculated as (D _84v / D _16V ) ^1/2 and the number average particle size distribution index (GSDp) is calculated as (D _84P / D _16P ) ^1/2 .

  The shape factor SF1 of the obtained toner is preferably from 100 to 140, more preferably from 110 to 135, from the viewpoint of image formability. The shape factor SF1 is obtained as follows. First, the optical microscope image of the toner spread on the slide glass is taken into a Luzex image analyzer through a video camera, the maximum length (ML) and the projected area (A) are measured for 50 or more toners, and SF1 is calculated by the following formula. The average value is obtained.

式中、ＭＬはトナー粒子の最大長を示し、Ａは粒子の投影面積を示す。

In the formula, ML represents the maximum length of toner particles, and A represents the projected area of the particles.

  The obtained toner is dried in the same manner as a normal toner for the purpose of imparting fluidity and improving cleaning properties, and then inorganic particles such as silica, alumina, titania and calcium carbonate, and resins such as vinyl resins, polyesters and silicones. The particles can be added to the surface of the toner particles while being sheared in a dry state.

  In addition, when adhering to the toner surface in an aqueous medium, examples of inorganic particles include silica, alumina, titania, calcium carbonate, magnesium carbonate, tricalcium phosphate, etc. Can be used by dispersing with an ionic surfactant, polymer acid, or polymer base.

The toner obtained by the method for producing an electrostatic charge image developing toner of the present invention described above is used as an electrostatic charge image developer. The developer is not particularly limited except that it contains the electrostatic image developing toner, and can have an appropriate component composition depending on the purpose. When the electrostatic image developing toner is used alone, it is prepared as a one-component electrostatic image developer, and when used in combination with a carrier, it is prepared as a two-component electrostatic image developer.
The carrier is not particularly limited, but usually, magnetic particles such as iron powder, ferrite, iron oxide powder, nickel, etc .; the magnetic particles as a core material and the surface thereof as a styrene resin, vinyl resin, ethylene resin, rosin Resin-coated carrier formed by coating a resin such as a resin based on polyester, polyester or melamine, or a wax such as stearic acid, and forming a resin coating layer; a magnetic material obtained by dispersing magnetic particles in a binder resin Examples include a distributed carrier. Among them, the resin-coated carrier is particularly preferable because the chargeability of the toner and the resistance of the entire carrier can be controlled by the configuration of the resin coating layer.
The mixing ratio of the toner of the present invention and the carrier in the two-component electrostatic image developer is usually 2 to 10 parts by weight of the toner with respect to 100 parts by weight of the carrier. The method for preparing the developer is not particularly limited, and examples thereof include a method of mixing with a V blender or the like.

Further, the electrostatic image developer (electrostatic image developing toner) can be used in an ordinary electrostatic image developing system (electrophotographic system) image forming method.
The image forming method of the present invention includes a latent image forming step of forming an electrostatic latent image on the surface of the latent image holding member, and developing the electrostatic latent image formed on the surface of the latent image holding member with a developer containing toner. A developing step for forming a toner image, a transfer step for transferring the toner image formed on the surface of the latent image holding member to the surface of the transfer target, and a fixing for thermally fixing the toner image transferred to the surface of the transfer target. An electrostatic charge image developing toner of the present invention as the toner, or the electrostatic charge image developer of the present invention as the developer.
For each of the above steps, a known step can be used in the image forming method, and are described in, for example, JP-A-56-40868 and JP-A-49-91231. Further, the image forming method of the present invention may include steps other than the above-described steps. For example, a cleaning step for removing the electrostatic charge image developer remaining on the electrostatic latent image carrier is preferable. Can be mentioned. In the image forming method of the present invention, an embodiment that further includes a recycling step is preferable. The recycling step is a step of transferring the electrostatic image developing toner collected in the cleaning step to a developer layer. The image forming method including the recycling step can be performed using an image forming apparatus such as a toner recycling system type copying machine or facsimile machine. Further, the present invention can be applied to a recycling system in which the cleaning step is omitted and toner is collected simultaneously with development.

As the latent image holding member, for example, an electrophotographic photosensitive member and a dielectric recording member can be used.
In the case of an electrophotographic photosensitive member, the surface of the electrophotographic photosensitive member is uniformly charged by a corotron charger, a contact charger or the like and then exposed to form an electrostatic latent image (latent image forming step). Next, the toner particles are adhered to the electrostatic latent image by contacting or approaching a developing roll having a developer layer formed on the surface to form a toner image on the electrophotographic photosensitive member (developing step). The formed toner image is transferred onto the surface of a transfer medium such as paper using a corotron charger or the like (transfer process). Further, the toner image transferred to the surface of the transfer target is heat-fixed by a fixing device, and a final toner image is formed.
In the heat fixing by the fixing device, a release agent is usually supplied to a fixing member in the fixing device in order to prevent offset and the like.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited at all.

  For the toner of this example, the following resin particle dispersion, colorant particle dispersion, and release agent particle dispersion were prepared, and the flocculant was added while mixing and stirring them at a predetermined ratio. Agglomerated particles are formed. Next, inorganic hydroxide is added to adjust the pH of the system from weakly acidic to neutral, and then the mixture is heated to a temperature equal to or higher than the glass transition point of the resin particles to fuse and unite. After completion of the reaction, a desired toner is obtained through sufficient washing, solid-liquid separation, and drying processes. Hereinafter, each preparation method is demonstrated.

(Example 1: Preparation of resin particle dispersion (1))
-3.6 parts by weight of dodecylbenzenesulfonic acid-80.0 parts by weight of 1,9-nonanediol-115.0 parts by weight of 1,10-decanedicarboxylic acid are mixed in a 500 ml flask and heated to 120 ° C with a mantle heater. After heating and melting the mixture, the contents became a viscous melt when kept at 90 ° C. for 8 hours with stirring and deaeration with a three-one motor.
Similarly, a neutralizing aqueous solution in which 2.0 parts by weight of 1N NaOH aqueous solution was dissolved in 790 parts by weight of ion-exchanged water heated to 90 ° C. was put into the flask and emulsified with a homogenizer (manufactured by IKA, Ultra Tarrax) for 5 minutes. Thereafter, the flask was cooled with room temperature water.
As a result, a crystalline polyester resin particle dispersion (1) having a resin particle center diameter of 220 nm, a melting point of 71 ° C., a weight average molecular weight of 14,000, and a solid content of 20% was obtained.
In addition, the particles of the resin particle dispersion (1) have a median diameter of 0.03 μm or less or 5.0 μm or more of the total ratio of particles (hereinafter referred to as the large / small particle total ratio) of 2.0%. The pH was 7.5.

  The stability of the resin particle dispersion (1) used was measured by weighing 100 g of the resin particle dispersion into a 300 ml stainless beaker, shearing in the beaker with IKA Ultra Turrax T50 for 1 minute, and then using a 77 micron nylon mesh. When the resin particle dispersion was filtered and examined by a method for observing the presence or absence of agglomeration, no agglomerate was observed, and the dispersion was in a stable state (◎).

(Example 2: Preparation of resin particle dispersion (2))
-Dodecylbenzenesulfonic acid 3.6 parts by weight-1,6-hexanediol 59 parts by weight-Sebacic acid 101 parts by weight

Mix in a 500 ml flask, heat to 130 ° C. with a mantle heater, melt the mixture, then hold at 80 ° C. for 8 hours with stirring and degassing with a three-one motor, and the contents become a viscous melt. It was.
Similarly, a neutralizing aqueous solution in which 2.0 parts by weight of 1N NaOH solution was dissolved in 650 parts by weight of ion-exchanged water heated to 80 ° C. was put into the flask, and emulsified with a homogenizer (manufactured by IKA, Ultra Tarrax) for 5 minutes. Thereafter, the flask was cooled with room temperature water.
As a result, a crystalline polyester resin particle dispersion (2) having a resin particle central diameter of 240 nm, a melting point of 69 ° C., a weight average molecular weight of 11,000, and a solid content of 20% was obtained.
The particles of the resin particle dispersion (2) had a large / small particle overall ratio of 4.7%, and the pH of the dispersion was 6.8.

  Further, when the stability of the used resin particle dispersion (2) was examined by the shear homogenization method described above, no aggregation was observed and the stability was good (◎).

(Example 3: Preparation of resin particle dispersion (3))
-3.0 parts by weight of dodecyl sulfate-80 parts by weight of 1,9-nonanediol-94 parts by weight of azelaic acid

Mix in a 500 ml flask, heat to 110 ° C. with a mantle heater, melt the mixture, and then hold at 70 ° C. for 8 hours with stirring and degassing with a three-one motor. The contents become a viscous melt. It was.
Similarly, a neutralizing aqueous solution in which 2.0 parts by weight of 1N NaOH solution was dissolved in 650 parts by weight of ion-exchanged water heated to 70 ° C. was put into the flask, and emulsified with a homogenizer (IKA, Ultra Tarrax) for 5 minutes. Thereafter, the flask was cooled with room temperature water.
As a result, a crystalline polyester resin particle dispersion (3) having a median diameter of 190 nm, a melting point of 54 ° C., a weight average molecular weight of 9,000, and a solid content of 20% was obtained.
The particles of the resin particle dispersion (3) had a large / small particle ratio of 0.8%, and the pH of the dispersion was 7.1.

  Further, when the stability of the used resin particle dispersion (3) was examined by the shear homogenization method described above, no aggregation was observed and the stability was good (◎).

(Example 4: Preparation of resin particle dispersion (4))
・ 2.5 parts by weight of paratoluenesulfonic acid, 3.6 parts by weight of scandium dodecylbenzenesulfonate (rare earth-containing catalyst), 46 parts by weight of terephthalic acid, polyoxyethylene (2.4) -2,2-bis (4- Hydroxyphenyl) propane
34 parts by weight / ethylene glycol 20 parts by weight

Mix in a 500 ml flask, heat to 140 ° C. with a mantle heater, melt the mixture, then hold at 140 ° C. for 10 hours with stirring and degassing with a three-one motor, and the contents become a viscous melt. It was.
Similarly, a neutralizing aqueous solution in which 3.0 parts by weight of a 1N NaOH solution was dissolved in 425 parts by weight of ion-exchanged water heated to 90 ° C. was put into the flask, and emulsified with a homogenizer (Ultra Tallax, manufactured by IKA) for 10 minutes. Thereafter, the flask was cooled with room temperature water.
As a result, an amorphous polyester resin particle dispersion (4) having a median diameter of the resin particles of 280 nm, a glass transition point of 55 ° C., a weight average molecular weight of 13,500, and a solid content of 20% was obtained.
The particles of the resin particle dispersion (4) had a large / small particle ratio of 3.5%, and the pH of the dispersion was 7.8.

  Further, when the stability of the resin particle dispersion (4) used was examined by the method of shear homogenization described above, the occurrence of agglomeration was slightly observed but at a level (◯) with no problem.

(Example 5: Preparation of resin particle dispersion (5))
-Dodecylbenzenesulfonic acid 2.4 parts by weight-Lipase (Pseudomonas genus: enzyme catalyst) 10 parts by weight-1,9-nonanediol 80 parts by weight-1,10-decanedicarboxylic acid 115 parts by weight

Mix in a 500 ml flask according to the above composition, heat to 120 ° C. with a mantle heater, melt the mixture, and then hold the mixture at 80 ° C. for 10 hours with stirring and deaeration with a three-one motor, and the contents will melt viscous I became a body.
Similarly, a neutralizing aqueous solution in which 2.0 parts by weight of 1N NaOH aqueous solution was dissolved in 820 parts by weight of ion-exchanged water heated to 80 ° C. was put into the flask and emulsified with a homogenizer (manufactured by IKA, Ultra Tarrax) for 5 minutes. Thereafter, the mixture was further emulsified in an ultrasonic bath for 10 minutes, and then the flask was cooled with room temperature water.
As a result, a non-crystalline polyester resin particle dispersion (5) having a median diameter of resin particles of 180 nm, a melting point of 70 ° C., a weight average molecular weight of 15,000, and a solid content of 20% was obtained.
The particles of the resin particle dispersion (5) had a large / small particle overall ratio of 4.2%, and the pH of the dispersion was 6.3.

  Further, when the stability of the used resin particle dispersion (5) was examined by the shear homogenization method described above, the occurrence of agglomeration was slightly observed but at a level (◯) with no problem.

(Comparative Example 1: Preparation of resin particle dispersion (6))
-Dodecylbenzenesulfonic acid 1.8 parts by weight-1,9-nonanediol 80 parts by weight-1,10-decanedicarboxylic acid 115 parts by weight

Mix in a 500 ml flask according to the above formulation, heat to 120 ° C. with a mantle heater, melt the mixture, and then keep the contents at 90 ° C. for 8 hours with stirring and deaeration with a three-one motor. It became a melt.
Similarly, 790 parts by weight of ion-exchanged water heated to 90 ° C. was put into a flask without adding a neutralizing base, emulsified with a homogenizer (IKA, Ultra Turrax) for 5 minutes, and then the flask was washed with room temperature water. Cooled down.
As a result, a crystal raw polyester resin particle dispersion (6) having a median diameter of 2,050 nm, a melting point of 70 ° C., a weight average molecular weight of 9,500, and a solid content of 20% was obtained.
The particles of the resin particle dispersion (6) had a large / small particle ratio of 10.8%, and the pH of the dispersion was 2.5.

  Further, when the stability of the used resin particle dispersion (6) was examined by the shear homogenization method described above, a large amount of aggregation was observed (×).

(Comparative Example 2: Preparation of resin particle dispersion (7))
・ Dodecylbenzenesulfonic acid 3.6 parts by weight ・ 1,4-butanediol 45 parts by weight ・ Azelaic acid 94 parts by weight

Mix in a 500 ml flask according to the above composition, heat to 110 ° C. with a mantle heater, melt the mixture, and then hold the mixture at 80 ° C. for 8 hours with stirring and deaeration with a three-one motor. I became a body.
Similarly, a neutralizing aqueous solution in which 2.0 parts by weight of 1N NaOH solution was dissolved in 570 parts by weight of ion-exchanged water heated to 80 ° C. was put into the flask, and emulsified with a homogenizer (manufactured by IKA, Ultra Tarrax) for 10 minutes. Thereafter, the mixture was further emulsified in an ultrasonic bath for 10 minutes, and then the flask was cooled with water at room temperature.
As a result, a crystalline polyester resin particle dispersion (7) having a median diameter of the resin particles of 40 nm, a melting point of 47 ° C., a weight average molecular weight of 21,000, and a solid content of 20% was obtained.
The particles of the resin particle dispersion (7) had an overall ratio of large and small particles of 10.8%, and the pH of the dispersion was 7.2.

  Further, when the stability of the used resin particle dispersion (7) was examined by the shear homogenization method described above, the occurrence of aggregation was observed (×).

The results of Examples 1 to 5 and Comparative Examples 1 and 2 are shown in Table 1.
In the table, the evaluation criteria for the stability of the resin particle dispersion are:
“◎” means no aggregation at all,
“○” is slightly agglomerated but no problem.
"△" is a slight aggregation occurrence,
“X” was regarded as a large amount of aggregation.

From these results shown in Table 1, the resin particle dispersion can be stabilized by setting the median diameter of the polycondensation resin particles that are polycondensed at a low temperature and emulsified and dispersed simultaneously with neutralization within a predetermined range as in this example. It can be seen that the property is improved.
In contrast, even in the case of polycondensation resin particles obtained by emulsifying and dispersing a polycondensed resin as in the comparative example, the median diameter deviates from a predetermined range, or after separately obtaining the polycondensation resin, the aqueous medium In the case of the polycondensation resin particles dispersed therein, it can be seen that even if the median diameter is within a predetermined range, the stability of the resin particle dispersion is poor.

(Preparation of resin particle dispersion (8): non-crystalline vinyl resin latex)
-Styrene 460 parts by weight-n-butyl acrylate 140 parts by weight-Acrylic acid 12 parts by weight-Dodecanethiol 9 parts by weight

  According to the above formulation, each component was mixed and dissolved to prepare a solution. On the other hand, 12 parts by weight of an anionic surfactant (manufactured by Rhodia, Dowfax) was dissolved in 250 parts by weight of ion-exchanged water, and the solution was added and dispersed and emulsified in a flask (monomer emulsion A). Furthermore, 1 part by weight of an anionic surfactant (manufactured by Rhodia, Dowfax) was dissolved in 555 parts by weight of ion-exchanged water and charged into a polymerization flask. The polymerization flask is sealed, a reflux tube is installed, and the polymerization flask is heated to 75 ° C. with a water bath while being slowly stirred while injecting nitrogen, and held.

  Next, 9 parts by weight of ammonium persulfate was dissolved in 43 parts by weight of ion-exchanged water and dropped into the polymerization flask through a metering pump over 20 minutes, and then the monomer emulsion A was also passed through the metering pump. Add dropwise over 200 minutes.

  Thereafter, the polymerization flask is held at 75 ° C. for 3 hours while stirring slowly, to complete the polymerization.

As a result, an anionic resin particle dispersion (8) in which the median diameter of the resin particles was 210 nm, the glass transition point was 53.5 ° C., the weight average molecular weight was 31,000, and the solid content was 42% was obtained.
The particles of the resin particle dispersion (8) had a large / small particle overall ratio of 0.2%.

(Preparation of colorant particle dispersion (1))
・ Yellow pigment (manufactured by Dainichi Seika Co., Ltd., Y74) 50 parts by weight ・ Anionic surfactant (Daiichi Kogyo Seiyaku, Neogen R) 5 parts by weight ・ Ion-exchanged water 200 parts by weight

  In accordance with the above composition, the components were mixed and dissolved, and dispersed for 5 minutes with a homogenizer (manufactured by IKA, Ultra Tarrax) and for 10 minutes with an ultrasonic bath, with a median diameter of 240 nm and a solid content of 21.5%. A Yellow colorant particle dispersion (1) was obtained.

(Preparation of colorant particle dispersion (2))
In the preparation of the colorant particle dispersion liquid (1), it was prepared in the same manner as the colorant particle dispersion liquid (1) except that a cyan pigment (manufactured by Dainichi Seika Co., Ltd., copper phthalocyanine B15: 3) was used instead of the yellow pigment. Thus, a Cyan colorant particle dispersion (2) having a center diameter (median diameter) of 190 nm and a solid content of 21.5% was obtained.

(Preparation of colorant particle dispersion (3))
In the preparation of the colorant particle dispersion (1), except that a magenta pigment (manufactured by Dainichi Ink Chemical Co., PR122) was used instead of the yellow pigment, it was prepared in the same manner as the colorant particle dispersion (1). A Magenta colorant particle dispersion (3) having a center diameter (median diameter) of 165 nm and a solid content of 21.5% was obtained.

(Preparation of colorant particle dispersion (4))
In the preparation of the colorant particle dispersion (1), except that a black pigment (Cabot, carbon black) was used instead of the yellow pigment, the colorant particle dispersion (1) was prepared in the same manner as the colorant particle dispersion (1). A Black colorant particle dispersion (4) having a median diameter of 170 nm and a solid content of 21.5% was obtained.

(Preparation of release agent particle dispersion)
・ 50 parts by weight of paraffin wax (manufactured by Nippon Seiwa Co., Ltd., HNP9; melting point 70 ° C.) 5 parts by weight of anionic surfactant (Dowfax made by Rhodia) 200 parts by weight of ion-exchanged water

  In accordance with the above composition, the components were heated to 95 ° C. and sufficiently dispersed with a homogenizer (IKA, Ultra Tarrax T50), then dispersed with a pressure discharge type homogenizer (Gorin homogenizer, Gorin), and the center diameter. A release agent particle dispersion having a median diameter of 180 nm and a solid content of 21.5% was obtained.

[Toner Example 6]
(Preparation of toner particles)
-Resin particle dispersion (1) 210 parts by weight (42 parts by weight of resin)
-Resin particle dispersion (8) 50 parts by weight (21 parts by weight of resin)
Colorant particle dispersion (1) 40 parts by weight (8.6 parts by weight of colorant)
Release agent particle dispersion 40 parts by weight (release agent 8.6 parts by weight)
・ Polyaluminum chloride 0.15 parts by weight ・ Ion exchange water 300 parts by weight

  In accordance with the above formulation, the components (excluding the resin particle dispersion (8)) were thoroughly mixed and dispersed in a round stainless steel flask using a homogenizer (IKA, Ultra Turrax T50), and then the flask was heated with an oil bath for heating. The mixture was heated to 42 ° C. with stirring and held at 42 ° C. for 60 minutes, and then 50 parts by weight (21 parts by weight of resin) of the resin particle dispersion (8) was added and gently stirred.

  Thereafter, the pH in the system was adjusted to 6.0 with a 0.5 mol / liter aqueous sodium hydroxide solution, and then heated to 95 ° C. while continuing stirring. During the temperature increase up to 95 ° C, the pH in the system usually drops to 5.0 or less, but here, an aqueous sodium hydroxide solution is added dropwise to keep the pH from dropping to 5.5 or less. did.

  After completion of the reaction, the mixture was cooled, filtered, sufficiently washed with ion exchange water, and then solid-liquid separated by Nutsche suction filtration. And it re-dispersed in 3 liters of ion-exchanged water at 40 ° C., and stirred and washed at 300 rpm for 15 minutes. This washing operation was repeated 5 times, followed by solid-liquid separation by Nutsche suction filtration, and then vacuum drying for 12 hours to obtain toner particles.

When the particle size of the toner particles was measured with a Coulter counter, the cumulative volume average particle size D ₅₀ was 4.8 μm, and the volume average particle size distribution index GSDv was 1.22. The shape factor SF1 of the toner particles obtained from the shape observation by Luzex was 131 potato shapes.

  To 50 parts by weight of the toner particles, 1.5 parts by weight of hydrophobic silica (manufactured by Cabot, TS720) was added and mixed by a sample mill to obtain an externally added toner.

  Then, using a ferrite carrier having an average particle diameter of 50 μm coated with 1% of polymethyl methacrylate (manufactured by Soken Chemical Co., Ltd.), the externally added toner is weighed so that the toner concentration becomes 5%. A developer was prepared by stirring and mixing for a minute.

(Evaluation of toner)
Using the above developer, Fuji Xerox's DocuCenterColor500 modified machine uses Fuji Xerox's J-coated paper as the transfer paper, and the process speed is adjusted to 180 mm / sec to examine toner fixability. It was confirmed that the oilless fixability by the PFA tube fixing roll was good, the minimum fixing temperature was 115 ° C. or higher, the image showed sufficient fixability, and the transfer paper was peeled without any resistance. Note that the minimum fixing temperature is that when the fixing temperature is gradually raised from a low temperature (usually around 70 ° C.), the image is fixed and then rubbed with white gauze to prevent contamination of the image. The fixing temperature was such that the toner did not adhere to the gauze.
As a result of examining the image quality under the same conditions as described above using the modified machine, the surface gloss of the image at a fixing temperature of 140 ° C. is as good as 65%, both developability and transferability are good, and there is no image defect. An image of good quality (◯) was shown.
Further, when the remodeling machine was used to gradually raise the fixing temperature under the same conditions as described above and the occurrence of hot offset was examined, no occurrence of hot offset was observed even at a fixing temperature of 200 ° C.
In the modified machine, a continuous print test of 50,000 sheets was performed at 23 ° C. and 55% RH, and the initial good image quality was maintained until the end. (Continuous test maintenance: ○)

[Toner Example 7]
In Example 6, the resin particle dispersion (1) was changed to the resin particle dispersion (2), the colorant particle dispersion (1) was changed to the colorant particle dispersion (2), and the mixture was heated at 95 ° C. Toner particles were obtained in the same manner as in Example 6 except that the pH was maintained at 5.0.

The cumulative volume average particle diameter D ₅₀ of the toner particles is 4.50 μm, and the volume average particle size distribution index GSDv is 1.20. The shape factor SF1 was slightly spherical with 125.

Using this toner particle, an externally added toner was obtained in the same manner as in Example 1 and a developer was further prepared. The toner fixability was examined in the same manner as in Example 6. As a result, oil-less fixability with a PFA tube fixing roll was obtained. It was confirmed that the minimum fixing temperature was 110 ° C. or higher, the image showed sufficient fixability, and the transfer paper was peeled off without any resistance. The surface gloss of the image at a fixing temperature of 150 ° C. was as good as 70%, both developability and transferability were good, and there was no image defect and a high quality and good image (◯) was shown. Also, no hot offset was observed at a fixing temperature of 200 ° C.
In the modified machine, a continuous print test of 50,000 sheets was performed at 23 ° C. and 55% RH, and the initial good image quality was maintained until the end. (Continuous test maintenance: ○)

[Toner Example 8]
In Example 6, the resin particle dispersion (1) was changed to the resin particle dispersion (3), the resin particle dispersion (8) was changed to the resin particle dispersion (4), and the colorant particle dispersion (2 ) To colorant particle dispersion (3), and toner particles were obtained in the same manner as in Example 6 except that the amount of polyaluminum chloride was changed to 0.12 parts by weight.

The accumulated volume average particle diameter D ₅₀ of the toner particles 4.20Myuemu, volume average particle size distribution index GSDv of 1.24, a shape factor SF1 of a spherical 120.

Using these toner particles, an externally added toner was obtained in the same manner as in Example 6, and a developer was further prepared. The toner fixability was examined in the same manner as in Example 1. As a result, oil-less fixability with a PFA tube fixing roll was investigated. It was confirmed that the minimum fixing temperature was 105 ° C. or higher, the image showed sufficient fixing properties, and the transfer paper was peeled off without any resistance. The surface gloss of the image at a fixing temperature of 150 ° C. was as good as 80%, both developability and transferability were good, and an extremely high quality image (◯) was obtained without image defects. No occurrence of hot offset was observed even at a fixing temperature of 200 ° C.
In the modified machine, a continuous print test of 50,000 sheets was performed at 23 ° C. and 55% RH, and the initial good image quality was maintained until the end. (Continuous test maintenance: ○)

[Toner Example 9]
Toner in the same manner as in Example 6, except that the resin particle dispersion (1) is changed to the resin particle dispersion (5) and the colorant dispersion is changed from (1) to (4). Particles were obtained.

The cumulative volume average particle diameter D ₅₀ of the toner particles is 3.80 μm, the volume average particle size distribution index GSDv is 1.25, and the shape factor SF1 is 133.

Using these toner particles, an externally added toner was obtained in the same manner as in Example 6, and a developer was further prepared. The toner fixability was examined in the same manner as in Example 1. As a result, oil-less fixability with a PFA tube fixing roll was investigated. It was confirmed that the minimum fixing temperature was 110 ° C. or higher, the image showed sufficient fixability, and the transfer paper was peeled off without any resistance. The surface gloss of the image at a fixing temperature of 150 ° C. was as good as 50%, both developability and transferability were good, and there was no image defect and a high quality and good (◯) image was shown. The occurrence of hot offset was not observed even at a fixing temperature of 200 ° C.
In the modified machine, a continuous print test of 50,000 sheets was performed at 23 ° C. and 55% RH, and the initial good image quality was maintained until the end. (Continuous test maintenance: ○)

[Toner Comparative Example 3]
In Example 7, toner particles were obtained in the same manner as in Example 7 except that the resin particle dispersion (2) was changed to the resin particle dispersion (6).

The toner particles had a cumulative volume average particle diameter D ₅₀ of 5.90 μm, a volume average particle size distribution index GSDv of 1.30, a shape factor SF1 of 137 and a potato shape.

Using these toner particles, an externally added toner was obtained in the same manner as in Example 6, and a developer was further prepared. The toner fixability was examined in the same manner as in Example 1. As a result, oil-less fixability with a PFA tube fixing roll was investigated. The image was satisfactory and the minimum fixing temperature was 130 ° C. or higher, and the image showed a sufficient fixing property, but the peeled state of the transfer paper was poor, and undulation and wrapping after fixing of the paper were confirmed. Hot offset was observed from the fixing temperature of 180 ° C. Coarse powder was generated in the toner, and defects such as white spots were observed in the image.
In the modified machine, a continuous print test was performed at 23 ° C. and 55% RH. The white image in the image deteriorated further from the initial image quality, and the evaluation was terminated at 5,000 sheets. (Continuous test maintenance: x)

[Toner Comparative Example 4]
In Example 7, toner particles were obtained in the same manner as in Example 7 except that the resin particle dispersion (2) was changed to the resin particle dispersion (7).

The accumulated volume average particle diameter D ₅₀ of the toner particles 5.40Myuemu, volume average particle size distribution index GSDv of 1.26, a shape factor SF1 was 122 spherical.

  Using these toner particles, an externally added toner was obtained in the same manner as in Example 6, and a developer was further prepared. The toner fixability was examined in the same manner as in Example 1. As a result, oil-less fixability with a PFA tube fixing roll was investigated. The image was not good, the minimum fixing temperature was 90 ° C. or more, and the image showed a sufficient fixing property, but the transfer paper was not peeled well, and undulation and winding after fixing of the paper were confirmed. In addition, significant hot offset has occurred from the fixing temperature of 140 ° C., there are image defects (×), and sufficient image evaluation has not been achieved. Also, image defects and winding of the paper after fixing are severe, and continuous print tests can be performed. I couldn't do it. (Continuous test maintenance: XX)

The results of Examples 6 to 9 and Comparative Examples 3 and 4 are summarized in Table 2.
The image quality evaluation criteria are
“◎” is extremely good,
“○” is good,
“X” was defined as occurrence of an image defect.
Moreover, evaluation of continuous test maintainability is as having mentioned above by each Example and the comparative example.

From these results, as in this example, the median diameter of the polycondensation resin particles that were polycondensed at a low temperature and emulsified and dispersed at the same time as neutralization was set within a predetermined range, so that the toner using the polycondensation resin as a raw material could be efficiently It can be seen that, in addition to making it possible to manufacture the toner, it is possible to dramatically improve the image quality fixing performance of the toner.
In contrast, even in the case of polycondensation resin particles obtained by emulsifying and dispersing a polycondensed resin as in the comparative example, the median diameter deviates from a predetermined range, or after separately obtaining the polycondensation resin, the aqueous medium In the case of the polycondensation resin particles dispersed in the toner, the toner characteristics (hot offset temperature, image quality, continuous test maintainability) may be worse than in the examples even if the median diameter is within a predetermined range. Recognize.

Claims (5)

A step of polycondensing a polycondensable monomer using an acid having a surface-active effect as a polycondensation catalyst to obtain a polycondensation resin; and
Said base in an aqueous medium plus dispersed polycondensation resin, saw including a step of median diameter of the resin particles to obtain a resin particle dispersion at 0.05μm or 2.0μm or less,
Resin particles for electrostatic charge image developing toner, wherein the acid having a surface-active effect is a sulfonic acid having an alkyl group or an aralkyl group, a sulfuric acid ester having an alkyl group or an aralkyl group, or a salt compound thereof. A method for producing a dispersion. A step of aggregating the resin particles in a dispersion containing at least a resin particle dispersion to obtain aggregated particles; and
A method for producing an electrostatic charge image developing toner comprising a step of heating and aggregating the aggregated particles,
The method for producing an electrostatic image developing toner, wherein the resin particle dispersion is a resin particle dispersion for an electrostatic image developing toner obtained by the production method according to claim 1.   An electrostatic image developing toner obtained by the method for producing an electrostatic image developing toner according to claim 2.   An electrostatic image developer comprising the electrostatic image developing toner according to claim 3 and a carrier. A latent image forming step of forming an electrostatic latent image on the surface of the latent image holding member;
A developing step of developing the electrostatic latent image formed on the surface of the latent image holding body with a developer containing toner to form a toner image;
A transfer step of transferring the toner image formed on the surface of the latent image carrier to the surface of the transfer target;
A fixing step of thermally fixing the toner image transferred to the surface of the transfer material,
An image forming method using the electrostatic image developing toner according to claim 3 as the toner, or the electrostatic image developer according to claim 4 as the developer.