JP4840040B2 - Electrostatic image developing toner, method for producing electrostatic image developing toner, electrostatic image developer, image forming method, and image forming apparatus - Google Patents

Description

  The present invention relates to a toner for developing an electrostatic charge image used in electrophotography, electrostatic recording, and the like, a method for producing the same, an electrostatic charge image developer using the toner, an image forming method, and an image forming apparatus. .

  Many methods are known as electrophotographic methods. In general, an exposure process for forming an electrical latent image using various means on a photosensitive layer using a photoconductive material, and a toner using toner. A development process for developing the image, a transfer process for transferring the toner image onto a recording material (recording medium) such as paper, a fixing process for fixing the toner image to the recording material by heating, pressure, thermal pressure, solvent vapor, or the like; The process consists of basic processes such as a cleaning process for removing the toner remaining in the body layer.

In an image forming apparatus using such an electrophotographic system, after an electrical latent image is formed on the surface of a photoreceptor charged to a predetermined potential, the latent image is developed with a developer containing at least toner. As a result, a toner image corresponding to the latent image is formed on the surface of the photoreceptor.
The development of the latent image formed on the surface of the photosensitive member is performed by the charged toner adhering to the latent image forming region on the surface of the photosensitive member by electrostatic force.

  Therefore, the toner used in the electrophotographic image forming apparatus is required to have good chargeability.

  The electrostatic charge developing toner used in such an electrophotographic image forming apparatus is desired to have a small particle size in order to improve sharpness and improve image quality. As a method for producing a toner having a small particle diameter, development of a polymerization method toner is active.

  For example, a mixed dispersion liquid prepared by mixing a resin particle dispersion liquid in which resin particles are dispersed by emulsion polymerization or the like and a dispersion liquid in which colorant particles or the like are dispersed is prepared to form an aggregate including resin particles. A method is known in which toner particles are prepared by fusing and aggregating the aggregates by heating after obtaining the aggregation step.

As a technique for producing a toner having good chargeability, for example, in the technique of Patent Document 1, a dispersion of resin particles obtained by polymerizing a polymerizable monomer in an aqueous solvent is prepared, and in the presence of an anionic surfactant. In the aqueous solvent, the resin particles are obtained by salting out, agglomerating and fusing, and the produced toner uses 1 to 1000 ppm of an anionic surfactant as an aggregating agent. By containing 250 to 20000 ppm of valent or trivalent ions in total, a toner having good chargeability is provided.
Japanese Patent Laid-Open No. 2002-278111

In the technique of Patent Document 1, only a surfactant having a sulfone group is used as the anionic surfactant. Since the surfactant having a sulfone group has high surface activity, the stability of the mixed dispersion can be improved.
However, in the production of toner particles, in order to stop the growth of the aggregated particles in the mixed dispersion, it is necessary to set the pH to 9 or more at the minimum, so that a large amount of alkali is required to stop the aggregation reaction. To do. For this reason, there is a concern that the chargeability of the manufactured toner particles deteriorates.

  The present invention has been made in consideration of the above facts, and has electrostatic dispersion image developing toner having dispersion stability of the mixed dispersion liquid in the toner production process and good chargeability, and a production method thereof, and An object of the present invention is to provide an electrostatic charge image developer, an image forming method, and an image forming apparatus using the electrostatic charge image developing toner.

As a result of intensive studies to solve the above problems, the present inventors have conceived the present invention described below and found that the problems can be solved.
That is, the electrostatic image developing toner of the present invention is
<1> An electrostatic charge developing toner containing at least a binder resin and a release agent,
A surfactant containing a metal element capable of taking a valence of 2 or more, a surfactant having a sulfone group, and a surfactant having a carboxyl group, and having the sulfone group with respect to 100 g of the binder resin solid content. The relationship between the amount a (mol) of the agent and the amount b (mol) of the surfactant having a carboxyl group with respect to 100 g of the binder resin solid content is the condition of the following formula (1) and the following formula (2). An electrostatic charge developing toner characterized by satisfying the above.
0.0015 ≦ a ≦ 0.006 Equation (1)
0.018 ≦ 1.62 × a + b ≦ 0.025 (2)

< 2 > In a mixed dispersion obtained by mixing a resin particle dispersion in which resin particles containing at least a binder resin are dispersed and a colorant dispersion in which a colorant is dispersed, at least the resin particles and the colorant are mixed. A method for producing a toner for developing electrostatic charge, comprising: an aggregating step for forming aggregated particles, and a fusing step for fusing the aggregated particles by heating, wherein the mixed dispersion has a valence of 2 or more. The amount of the surfactant having a sulfone group with respect to 100 g of the binder resin solid content a (mol), which comprises a metal element capable of taking a surfactant, a surfactant having a sulfone group, and a surfactant having a carboxyl group And the amount b (mol) of the surfactant having a carboxyl group with respect to 100 g of the binder resin solid content satisfies the conditions of the following formula (3) and the following formula (4): That is a method for producing a toner for developing an electrostatic image.
0.0015 ≦ a ≦ 0.006 Equation (3)
0.018 ≦ 1.62 × a + b ≦ 0.025 Equation (4)

< 3 > An electrostatic latent image developer comprising the electrostatic charge developing toner according to <1 > .

< 4 > A charging step for charging the surface of the image carrier, and an electrostatic latent image corresponding to image information on the charged surface of the image carrier is developed with an electrostatic latent image developer containing at least an electrostatic charge developing toner. The image forming method includes at least a developing step for obtaining a toner image, a transfer step for transferring the toner image on the image carrier to a recording medium, and a fixing step for fixing the toner image on the recording medium. In the image forming method, the electrostatic charge developing toner is the electrostatic latent image developing toner described in the above item <1 > .

< 5 > A charging unit for charging the surface of the image bearing member, and an electrostatic latent image corresponding to image information on the surface of the image bearing member charged by the charging unit, and an electrostatic latent image including at least an electrostatic charge developing toner An image forming apparatus comprising: a developing unit that develops a toner image by developing with a developer; a transfer unit that transfers the toner image on the image carrier to a recording medium; and a fixing unit that fixes the toner image on the recording medium. In the image forming apparatus, the electrostatic charge developing toner is the electrostatic latent image developing toner described in <1 > .

  According to the electrostatic image developing toner, the electrostatic image developing toner manufacturing method, the electrostatic charge image developer, the image forming method, and the image forming apparatus of the present invention, the dispersion stability of the mixed dispersion in the toner manufacturing process is improved. And a method for producing the same, and an electrostatic image developer, an image forming method, and an image forming apparatus using the electrostatic image developing toner. With the goal. be able to.

  Hereinafter, the present invention will be described in the order of electrostatic charge image developing toner, electrostatic charge image developing toner manufacturing method, electrostatic charge image developer, and image forming method.

Hereinafter, the present invention will be described in detail.
<Toner for electrostatic charge development>
The electrostatic charge developing toner of the present invention (hereinafter sometimes simply referred to as “toner”) is an electrostatic charge developing toner containing at least a binder resin and a release agent, and has a bivalent or higher value. The amount a of the surfactant having a sulfone group with respect to 100 g of the binder resin solid content a containing a metal element capable of taking a number, a surfactant having a sulfone group, and a surfactant having a carboxyl group mol) and the amount b (mol) of the surfactant having a carboxyl group with respect to 100 g of the binder resin solid content satisfies the conditions of the following formula (1) and the following formula (2). It is said.

0.0015 ≦ a ≦ 0.006 Equation (1)
0.018 ≦ 1.62 × a + b ≦ 0.025 (2)

  In addition, the method for producing an electrostatic charge developing toner of the present invention comprises mixing and dispersing a resin particle dispersion in which resin particles containing at least a binder resin are dispersed and a colorant dispersion in which a colorant is dispersed. A method for producing an electrostatic charge developing toner, comprising: an aggregation step of forming aggregated particles containing at least the resin particles and a colorant in a liquid; and a fusion step of fusing the aggregated particles by heating. The mixed dispersion contains a metal element capable of having a valence of 2 or more, a surfactant having a sulfone group, and a surfactant having a carboxyl group, and the sulfone with respect to 100 g of the binder resin solid content. The relationship between the amount a (mol) of the surfactant having a group and the amount b (mol) of the surfactant having a carboxyl group with respect to 100 g of the binder resin solid content is expressed by the following formula (3) and It is characterized by satisfying the serial formula (4).

0.0015 ≦ a ≦ 0.006 Equation (3)
0.018 ≦ 1.62 × a + b ≦ 0.025 Equation (4)

  The electrostatic charge developing toner of the present invention comprises at least a mixed dispersion obtained by mixing a resin particle dispersion in which resin particles containing at least a binder resin are dispersed and a colorant dispersion in which a colorant is dispersed. After passing through the agglomeration step for forming the agglomerated particles including the resin particles and the colorant, in the fusing step, the agglomerated particles are heated and fused.

  In the toner and the toner manufacturing method of the present invention, by using the above-described configuration and the manufacturing method, it is possible to obtain a toner having good chargeability and to obtain good dispersion stability of the mixed dispersion in the toner manufacturing process. It has been found that it can be obtained.

Here, the “good dispersion stability of the mixed dispersion liquid” indicates a state in which particles in the mixed dispersion liquid are dispersed and the amount of precipitate of the aggregates is very small.
The “good chargeability” of the toner indicates that the toner does not adhere to a portion that is not a latent image during development because the distribution of the charge amount is small among the toner particles.

  It is known that the surfactant having a sulfone group has high surface activity because it has a large amount of charge dissociation and a large interaction with static electricity generated by charging with a medium. For this reason, the dispersion stability of the mixed dispersion liquid can be obtained by adding a surfactant having a sulfone group to the mixed dispersion liquid in the aggregation process at the time of toner production.

  Specific examples of the surfactant having a sulfone group include, for example, sodium alkylnaphthalene sulfonate, sodium glycol ether sulfonate, sodium dialkyl sulfosuccinate, sodium alkyl allyl sulfonate, polyoxyethylene noniphenyl, which are sulfonate surfactants. Examples include sodium ether sulfonate or sodium alkyldiphenyl ether disulfonate.

  As described above, when a surfactant having a sulfone group is added to the mixed dispersion, the surfactant having a sulfone group is in an ionized state even in a low pH mixed dispersion such as pH 3 or lower. Therefore, the dispersion stability of the mixed dispersion can be improved. However, in order to stop the growth of the aggregated particles in the mixed dispersion, it is necessary to add a large amount of alkali to the mixed solution. Therefore, the addition of a surfactant having a sulfone group can increase the chargeability of the aggregated particles. There is concern that it will get worse.

  Therefore, in the present invention, the mixed dispersion further contains a surfactant having a carboxyl group.

  A surfactant having a carboxyl group is less effective as a surfactant than a surfactant having a sulfone group, but the surfactant having a sulfone group penetrates into the agglomerated particles and is relatively agglomerated. It is considered that the chargeability of the aggregated particles in the mixed dispersion liquid can be ensured in order to suppress penetration into the inside of the surfactant having a sulfone group, which is abundant on the particle surface.

  The surfactant having a carboxyl group should not be restricted at all. For example, higher fatty acid alkali salts, alkyl ether carboxylates, alkyl ester carboxylates, acylamino acid salts, betaine acetate type amphoteric surfactants. Agents, imidazoline type amphoteric surfactants and the like. Examples of the higher fatty acid alkali salt include lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, oleic acid, coconut oil fatty acid, palm kernel oil fatty acid, sunflower oil fatty acid, beef tallow fatty acid sodium salt, potassium salt, Examples include triethanolamine salt and tripropanolamine salt. Examples of the alkyl ether carboxylic acid include POE lauryl ether acetate, POE tridecyl ether acetate, and the like. Examples of the alkyl ester carboxylate include sodium lauroyl lactate, sodium myristoyl lactate, and sodium stearoyl lactate. Examples of the acyl amino acid salt include coconut oil acyl glutamate, lauroyl acyl glutamate, cocoyl sarcosine salt, lauroyl sarcosine salt, myristoyl sarcosine salt, oleyl sarcosine salt, lauroyl methylalanine salt and the like.

  Examples of the betaine acetate type amphoteric surfactant include lauryldimethylaminoacetic acid betaine, coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, and the like. Examples of the imidazoline type amphoteric surfactant include N-coconut oil fatty acid acyl-N-carboxymethyl-N-hydroxyethylethylenediamine salt. Of these, higher fatty acid alkali salts, alkyl ester type carboxylates and acylamino acid salts are particularly preferred.

  The content of each of the surfactant having a sulfone group and the surfactant having a carboxyl group in the toner, and the amount added to the mixed dispersion at the time of toner production improve the chargeability of the produced toner. At the same time, it is determined to realize both good dispersion stability of the mixed dispersion.

  Specifically, the content of the surfactant having a sulfone group and the surfactant having a carboxyl group is the amount of the surfactant having a sulfone group with respect to 100 g of the binder resin solid content contained in the toner. When the amount of the surfactant having a carboxylic acid group with respect to 100 g of binder resin solid content contained in the toner is b (mol), the following formula (1) and the following formula (2) are satisfied. It is essential.

0.0015 ≦ a ≦ 0.006 Equation (1)
0.018 ≦ 1.62 × a + b ≦ 0.025 (2)

In addition, as shown in FIG. 1, “1.62” in the formula (2) is a relative value of a surfactant having a sulfone group as a surfactant with respect to a surfactant having a carboxyl group. This is a value obtained by measuring the amount of the surfactant having a carboxyl group of the surfactant having a sulfone group when the amount of the surfactant having a carboxyl group is in an appropriate range.
Further, “1.62 × a + b” is a value indicating the sum of surfactants that can be used when only surfactants having a carboxyl group are used.

  If the amount a of the surfactant having a sulfone group is less than 0.0015, there is a problem that the particle size distribution at the time of aggregation cannot be maintained. If the amount a exceeds 0.006, the charge amount of the finished toner decreases. There's a problem.

  Further, if the value of “1.62 × a + b” is less than 0.018, there is a problem that the particle size distribution at the time of aggregation cannot be maintained, and if it exceeds 0.0025, the charge amount of the finished toner decreases. There is a problem to say.

  The mixed dispersion and the produced toner contain a metal element that can take a valence of 2 or more.

  A metal element that can take a valence of 2 or more can function as an aggregating agent that aggregates various particles such as a binder resin contained in the mixed dispersion. By using a bivalent or higher-valent metal element, a toner having excellent charging characteristics can be obtained.

  The metal ion is essential to be a metal ion capable of taking a valence of 2 or more, and more preferably a metal ion of 3 or more.

  Metal ions that can take a valence of 2 or more have a lower critical coagulation concentration (coagulation value or coagulation point) than monovalent metal ions. Aggregation of various particles in the mixed dispersion can be advanced.

  The “critical aggregation concentration” is an index relating to the stability of the dispersion in the dispersion, and indicates the concentration at which aggregation occurs when a flocculant is added. This critical coagulation concentration varies greatly depending on the latex itself and the dispersant. For example, it is described in Seizo Okamura et al., “Polymer Chemistry” 17,601 (1960) and the like, and the value can be known by following these descriptions.

  Examples of the divalent or higher metal element include alkaline earth metals such as calcium and magnesium, divalent metals such as manganese and copper, and trivalent metals such as iron and aluminum. Among these, calcium, magnesium and aluminum are particularly preferable.

In addition, what is necessary is just to add the metal salt of these metal elements in a mixed dispersion, in order to add these metal elements in a mixed dispersion.
Specific examples of the metal salt include magnesium chloride, calcium chloride, calcium nitrate, zinc chloride, copper sulfate, magnesium sulfate, and manganese sulfate. Examples of the trivalent metal salt include aluminum chloride and iron chloride. These can be appropriately selected according to the purpose.

  In the present invention, the content of the divalent or higher-valent metal element in the toner is preferably 0.01% by weight to 1% by weight, more preferably 0.01% by weight to 0.1% by weight, and still more preferably. 0.01 wt% to 0.05 wt% is preferable.

  During the production of the toner, the mixed dispersion is adjusted using the metal salt described above so that the concentration is equal to or higher than the critical aggregation concentration. At this time, as a matter of course, whether the metal salt is added directly or as an aqueous solution is arbitrarily selected according to the purpose. When added as an aqueous solution, the added metal salt must be equal to or higher than the critical aggregation concentration of the aggregated particles with respect to the volume of the mixed dispersion and the total volume of the metal salt aqueous solution.

  The concentration of the metal salt used as the flocculant may be equal to or higher than the critical aggregation concentration, but is preferably added twice or more, more preferably 5 times or more the critical aggregation concentration.

  In addition, composite resin particles (the case where the particles have a multi-layer structure or when other structural components such as additives are included in the particles are referred to as composite resin particles) or a mixture in which colorant particles are dispersed The temperature of the mixed dispersion when adding the aggregating agent to the dispersion is preferably equal to or lower than the glass transition temperature (Tg) of the composite resin particles, and specifically in the range of 30 ° C to 65 ° C. Is more preferable, and 40 ° C to 55 ° C is more preferable.

  In the present invention, the toner is manufactured by the above-described manufacturing method, and the toner having the above-described configuration and excellent chargeability and excellent dispersion stability of the mixed dispersion is provided. can do.

Hereinafter, the structure of the electrostatic charge developing toner of the present invention will be described in order.
(Binder resin)
The binder resin used in the toner of the present invention may be an amorphous resin alone or a crystalline resin alone, or a crystalline resin and an amorphous resin may be mixed and used at the same time. Good.

  The “crystallinity” of the above “crystalline resin” means that in differential scanning calorimetry (DSC), it has a clear endothermic peak, not a stepwise change in endothermic amount. It means that the half-value width of the endothermic peak when measured at a temperature rate of 10 (° C./min) is within 10 ° C. On the other hand, a resin whose half width exceeds 10 ° C. or a resin with no clear endothermic peak means an amorphous resin (amorphous resin), but as an amorphous resin used in the present invention, it is clear. It is preferable to use a resin in which no endothermic peak is observed.

  In addition, it is preferable that the glass transition temperature of the amorphous resin in this invention is the range of 45-80 degreeC, and it is more preferable that it is the range of 50-70 degreeC. When the glass transition temperature is less than 45 ° C., the toner tends to easily block during storage or in the developing device (a phenomenon in which toner particles are aggregated into a lump). On the other hand, if the glass transition temperature exceeds 80 ° C., the toner fixing temperature increases, which is not preferable.

  In the present invention, a polyester resin obtained by condensation polymerization of a polyvalent carboxylic acid component and a polyhydric alcohol component is used as the binder resin.

  Examples of the polyvalent carboxylic acids used in the production of the amorphous polyester resin used in the present invention include oxalic acid, succinic acid, glutaric acid, adipic acid, peric acid, azelaic acid, sebacic acid, and 1,9-nonanedicarboxylic acid. Aliphatic dicarboxylic acids such as 1,10-decanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid; phthalic acid, isophthalic acid, terephthalic acid, naphthalene- Aromatic dicarboxylic acids such as dibasic acids such as 2,6-dicarboxylic acid, malonic acid, and mesaconic acid; and the like, and anhydrides and lower alkyl esters thereof are also included, but not limited thereto.

  Examples of the trivalent or higher carboxylic acid include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, and the like, and anhydrides thereof. And lower alkyl esters. These may be used individually by 1 type and may use 2 or more types together.

  Moreover, as an acid component, it is preferable that the divalent or higher carboxylic acid component which has a sulfone group other than the above-mentioned aliphatic dicarboxylic acid and aromatic dicarboxylic acid is contained. A dicarboxylic acid having a sulfone group is effective in that it can favorably disperse a coloring material such as a pigment.

  Examples of the dicarboxylic acid having a sulfone group include, but are not limited to, 2-sulfoterephthalic acid sodium salt, 5-sulfoisophthalic acid sodium salt, and sulfosuccinic acid sodium salt. Moreover, these lower alkyl esters, acid anhydrides, etc. are also mentioned.

  Moreover, as trivalent or more carboxylic acid which has a sulfone group, the sodium salt which the sulfone group substituted by trimellitic acid can be mentioned, for example.

  The polyvalent carboxylic acid contained in the polyester resin contained in the binder resin used in the production of the toner of the present invention preferably contains a divalent or higher carboxylic acid having a sulfone group as a copolymerization component, and the polyester. Weight ratio B of divalent or higher carboxylic acid having a sulfone group to acid component contained in resin, and weight ratio B of weight sum of surfactant having sulfone group and surfactant having carboxyl group to polyester resin The relationship between and preferably satisfies all of the following formulas (5), (6), and (7).

0.2 ≦ A ≦ 3.0 Equation (5)
0.4 ≦ B ≦ 4.0 Equation (6)
A + B <7.0 Equation (7)

A polyester resin is used as the binder resin, and this polyester resin contains a divalent or higher polyvalent carboxylic acid component containing a sulfone group as an essential component, thereby greatly improving the stability of the dispersion liquid in which the binder resin is dispersed. To be improved.
However, the more the divalent or higher carboxylic acid containing a sulfone group is contained in the polyester resin, the higher the hydrophilicity of the polyester resin itself, and the dispersion stability of the resin particle dispersion in which the resin particles containing the polyester resin are dispersed. However, after being manufactured as a toner, moisture in the air is adsorbed particularly in a high-temperature and high-humidity environment, leading to a decrease in charge and deterioration of transferability.

  For this reason, the weight ratio A of the divalent or higher carboxylic acid having a sulfone group to the acid component contained in the polyester resin is preferably in the range of 0.2 to 3.0, and is 0.3 to 2.0. The range is more preferable, and the range of 0.3 to 1.5 is particularly preferable.

  If the weight ratio A is less than 0.2, the effect on the dispersion stability of the mixed dispersion is insufficient, and if the weight ratio A exceeds 3.0, the toner's hygroscopicity becomes worse, which is not preferable.

  On the other hand, the weight ratio B of the total weight of the surfactant having a sulfone group and the surfactant having a carboxyl group is preferably in the range of 0.4 to 4.0 with respect to the polyester resin component. It is more preferably in the range of 4 to 3.0, particularly preferably in the range of 0.4 to 2.0.

  In the aggregation step, when the pH of the mixed dispersion is set to an acidic region of pH 4.0, for example, the electrostatic repulsion effect due to the dissociation of the carboxyl group contained in the polyester resin is suppressed, so that the weight ratio B is 0.00. If it is less than 4, the dispersion effect by the surfactant is reduced, the resin particles are aggregated, and it becomes difficult to produce toner particles.

  On the other hand, when the weight ratio B exceeds 4.0, the residual amount of the anionic surfactant (the sum of the weight of the surfactant having a sulfone group and the surfactant having a carboxyl group) in the toner after fusing is small. This increases the hygroscopicity of the toner or the dielectric properties, resulting in problems such as toner charge reduction.

  Further, when the value of “A + B” is 7.0 or more, the sulfone group component remaining in the toner increases, and the toner hygroscopicity is deteriorated.

  More preferably, the divalent or higher carboxylic acid having a sulfone group with respect to the acid component contained in the polyester resin is more than the weight ratio B of the total weight of the surfactant having a sulfone group and the surfactant having a carboxyl group. It is preferable that the acid weight ratio A is smaller.

  In the case of an anionic surfactant in the mixed dispersion, it is possible to remove the surfactant on the toner particle surface by forming a latent image after the toner particles are formed. On the other hand, the inclusion of a divalent or higher carboxylic acid component having a sulfone group in the skeleton of the binder resin makes it difficult to remove the sulfone group that is a hydrophilic group. There is a concern that the property deteriorates and causes a decrease in charge. For this reason, it is necessary to refrain from using the anionic surfactant as much as possible.

  Thus, when the weight ratio A and the weight ratio B satisfy all of the above formulas (5), (6), and (7), resin particles made of a polyester resin as a binder resin can be obtained. Stability at the time of aggregation can be imparted, and a toner having excellent pigment dispersion and sharp particle size distribution can be obtained.

  The “stability at the time of aggregation” indicates a state where the particle size distribution of the aggregated particles is narrow in the step of granulating the aggregated particles and controlling the particle size.

  Further, the surfactant having the sulfone group remaining in the toner when the weight ratio A and the weight ratio B satisfy all of the formulas (5), (6), and (7). The content of the surfactant having a carboxyl group can be less than 1.0% by weight.

The anionic surfactant remaining in the toner particles causes deterioration of the hygroscopicity of the toner particles, deterioration of dielectric characteristics, and reduction of electric resistance. Image density and image quality are deteriorated due to reduction of toner charge and transferability. Therefore, it is necessary to reduce it as much as possible by cleaning the toner particles.
For this reason, in the present invention, the surfactant component remaining in the produced toner can be reduced by the production method described above, so that it is possible to suppress a decrease in chargeability due to deterioration in the hygroscopicity of the toner.

  The method for measuring the surfactant having a sulfone group and the surfactant having a carboxyl group in the toner is described in “Surfactant Analysis and Test Method” published by Kodansha (1988). However, the specific method for measuring the content of the surfactant represented by the general formulas (7) and (8) is as follows.

  1 g of toner is dissolved in 50 ml of chloroform, the surfactant is extracted from the chloroform layer with 100 ml of ion-exchanged water, this chloroform layer is extracted once more with 100 ml of ion-exchanged water, and a total of 200 ml of extract (water layer) is reduced to 500 ml. The diluted solution is used as a test solution and colored with methylene blue according to the method defined in JIS 33636, the absorbance is measured, and the content in the toner is measured from a separately prepared calibration curve.

  Examples of the polyhydric alcohols contained in the polyester resin include aliphatic polyhydric alcohols, alicyclic polyhydric alcohols, and aromatic polyhydric alcohols. Aliphatic polyhydric alcohols include ethylene glycol, propylene glycol, 1,3-propanediol, 2,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, Ring opening of lactones such as neopentyl glycol, diethylene glycol, dipropylene glycol, dimethylol heptane, 2,2,4-trimethyl-1,3-pentanediol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ε-caprolactone Examples include aliphatic diols such as lactone-based polyester polyols obtained by polymerization, triols such as trimethylolethane, trimethylolpropane, glycerin, and pentaerythritol, and tetraols.

  Alicyclic polyhydric alcohols include 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, spiroglycol, hydrogenated bisphenol A, ethylene oxide adduct and propylene oxide adduct of hydrogenated bisphenol A, tricyclodecane Examples include diol, tricyclodecane dimethanol, dimer diol, hydrogenated dimer diol and the like.

  As aromatic polyhydric alcohols, para-xylene glycol, meta-xylene glycol, ortho-xylene glycol, 1,4-phenylene glycol, ethylene oxide adduct of 1,4-phenylene glycol, bisphenol A, ethylene oxide adduct of bisphenol A and Examples thereof include propylene oxide adducts.

  The glass transition point of the amorphous polyester resin used in the present invention must be 50 ° C. or higher, and more preferably 60 ° C. or higher and lower than 90 ° C. When the glass transition point is lower than this, there is a tendency to aggregate during handling or storage, which may cause a problem in storage stability. On the other hand, when the temperature is 90 ° C. or higher, the fixability is deteriorated.

  Moreover, it is preferable that the softening point of the amorphous polyester resin used for this invention is the range of 60 to 90 degreeC. In a toner in which the softening temperature of the amorphous polyester resin is kept lower than this, the toner tends to aggregate during handling or storage, and the fluidity may be greatly deteriorated particularly during long-time storage. If the softening point is higher than this, the fixing property is hindered.

  On the other hand, the crystalline polyester resin is not particularly limited as long as it is a polyester resin having crystallinity, and a known resin material can be used, but 2 having the sulfone group contained in the amorphous polyester resin. It is preferable not to contain a carboxylic acid having a valency or higher as a copolymerization component.

  For example, styrenes; methyl acrylate, ethyl acrylate, butyl acrylate, propyl acrylate, lauryl acrylate, ethyl hexyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, propyl methacrylate, lauryl methacrylate, methacryl Esters having a vinyl group such as ethylhexyl acid, vinyl acetate, vinyl benzoate; carboxylic acids having a double bond such as methyl maleate, ethyl maleate, butyl maleate; olefins such as ethylene, propylene, butylene, butadiene Carboxylic acids having a double bond such as acrylic acid, methacrylic acid, maleic acid, etc .; and those obtained by polymerization or copolymerization of two or more types, and those obtained by mixing these.

  Furthermore, an epoxy resin, a melamine resin polyester resin, a polyurethane resin, a polyamide resin, a cellulose resin, or a mixture of these with the vinyl resin, or a graft obtained when a vinyl monomer is polymerized in the presence of these resins. A polymer etc. are mentioned.

  As the crystalline resin contained in the toner of the present invention, when used as a toner of an electrophotographic image forming apparatus, the details of which will be described later, fixing property to paper at the time of fixing, charging property, and melting point adjustment within a preferable range From this point of view, it is preferable to use a crystalline polyester resin. It is more preferable to use an aliphatic crystalline polyester resin having an appropriate melting point.

  The crystalline polyester resin is synthesized from an acid (dicarboxylic acid) component and an alcohol (diol) component. In the present invention, a copolymer obtained by copolymerizing other components in a proportion of 50% by weight or less with respect to the crystalline polyester main chain is also referred to as crystalline polyester.

  The method for producing the crystalline polyester resin is not particularly limited, and can be produced by a general polyester polymerization method in which an acid component and an alcohol component are reacted. Examples thereof include direct polycondensation and transesterification. Depending on the type of monomer, it can be used separately.

  The production of the crystalline polyester resin can be carried out at a polymerization temperature of 180 to 230 ° C., and the reaction is carried out while reducing the pressure in the reaction system as necessary to remove water and alcohol generated during condensation. When the monomer is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added as a solubilizer and dissolved. In the polycondensation reaction, the dissolution auxiliary solvent is distilled off. In the case where a monomer having poor compatibility exists in the copolymerization reaction, it is preferable that the monomer having poor compatibility and the monomer and the acid or alcohol to be polycondensed are condensed in advance and then polycondensed together with the main component.

  Catalysts that can be used in the production of the crystalline polyester resin include alkali metal compounds such as sodium and lithium; alkaline earth metal compounds such as magnesium and calcium; metals such as zinc, manganese, antimony, titanium, tin, zirconium, and germanium Compounds: Phosphorous acid compounds, phosphoric acid compounds, amine compounds, and the like, and specific examples include the following compounds.

  Specifically, for example, sodium acetate, sodium carbonate, lithium acetate, lithium carbonate, calcium acetate, calcium stearate, magnesium acetate, zinc acetate, zinc stearate, zinc naphthenate, zinc chloride, manganese acetate, manganese naphthenate, titanium Tetraethoxide, titanium tetrapropoxide, titanium tetraisoproxide, titanium tetrabutoxide, antimony trioxide, triphenylantimony, tributylantimony, tin formate, tin oxalate, tetraphenyltin, dibutyltin dichloride, dibutyltin oxide, diphenyltin oxide, zirconium Tetrabutoxide, zirconium naphthenate, zirconyl carbonate, zirconyl acetate, zirconyl stearate, zirconyl octylate, germanium oxide, Li phenyl phosphite, tris (2, 4-t-butylphenyl) phosphite, ethyltriphenylphosphonium bromide, triethylamine, compounds such as triphenyl amine.

The molecular weight of the crystalline resin is not particularly limited, but the weight average molecular weight is preferably 8000 or more, and more preferably 10,000 or more. However, it is preferably 100,000 or less, and more preferably 70000 or less. If the weight average molecular weight of the crystalline resin is less than 8000, there is a risk that the strength of the fixed image will be insufficient, or crushing may occur while stirring the developing device. Further, if the weight average molecular weight of the crystalline resin is larger than 100,000, the fixing temperature may be increased.
In addition, the measurement of the said molecular weight can be performed similarly to the molecular weight measuring method of the said styrene copolymer.

  As melting | fusing point of crystalline resin, Preferably it is 50-120 degreeC, More preferably, it is 60-110 degreeC. If the melting point is lower than 50 ° C., the storage stability of the toner and the storage stability of the toner image after fixing may become a problem. On the other hand, if the melting point is higher than 120 ° C., sufficient low-temperature fixing cannot be obtained compared to the conventional toner. There is a case.

Here, the melting point of the crystalline resin was measured by ASTM / D3418-8 when a differential scanning calorimeter (DSC) was used and the temperature was measured 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 differential scanning calorimetry shown.
A crystalline resin may show a plurality of melting peaks, but in the present invention, the maximum peak is regarded as the melting point.

For the measurement of the maximum peak, for example, DSC-7 manufactured by Perkin Elmer is used. The temperature correction of the detection part of the apparatus uses the melting points of indium and zinc, and the correction of heat quantity uses the heat of fusion of indium. As the sample, an aluminum pan was used, an empty pan was set as a control, and the measurement was performed at a heating rate of 10 ° C./min.
The glass transition point and melting point of the binder resin described above were also measured by the same method as described above.

  Crystalline vinyl resins include amyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, Undecyl (meth) acrylate, tridecyl (meth) acrylate, myristyl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, oleyl (meth) acrylate, behenyl (meth) acrylate, etc. Examples thereof include vinyl resins using long-chain alkyl or alkenyl (meth) acrylic acid esters. In the present specification, the description “(meth) acryl” means to include both “acryl” and “methacryl”.

(Coloring agent)
As the colorant, known organic or inorganic pigments and dyes and oil-soluble dyes can be used. For example, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 185, C.I. I. Pigment blue 15: 1, C.I. I. Pigment Blue 15: 3, Lamp Black (C.I.No. 77266), Rose Bengal (C.I.No. 45432), Carbon Black, Nigrosine Dye (C.I.No. 5041B5), Metal Complex Dye, Metal Derivatives of complex salt dyes and mixtures thereof can be mentioned.

Furthermore, various metal oxides such as silica, aluminum oxide, magnetite and various ferrites, cupric oxide, nickel oxide, zinc oxide, zirconium oxide, titanium oxide, and magnesium oxide, and appropriate mixtures thereof are listed. It is done. The colorant is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP permeability, and dispersibility in the toner.
The content of the colorant depends on the toner particle size and the development amount, but generally a ratio of about 1 to 50 parts by mass with respect to 100 parts by mass of the toner is appropriate. 2-25 mass parts is especially preferable.

These colorants are dispersed by a known method. For example, a rotary shear type homogenizer, a media type ball mill, a sand mill, or the like is used.
Further, when these colorants are used in the emulsion aggregation method described later, a polar surfactant is used and dispersed in an aqueous system by the homogenizer.

(Other ingredients)
As described above, the component constituting the toner of the present invention is not particularly limited as long as it contains at least a binder resin containing a crystalline resin and an amorphous resin and a colorant. In addition, other components such as a release agent may be included.

Specific examples of the release agent include the following.
For example, waxes and waxes include plant waxes such as carnauba wax, cotton wax, wood wax, rice wax, animal waxes such as beeswax and lanolin, mineral waxes such as ozokerite and cercin, paraffin, and microcrystalline. And petroleum waxes such as petrolatum. In addition to these natural waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax and polyethylene wax, fatty acid amides such as 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide, and chlorinated hydrocarbons, esters and ketones Synthetic waxes such as ether can also be used.

  Still other release agents include homopolymers or copolymers of polyacrylates such as poly-n-stearyl methacrylate and poly-n-lauryl methacrylate (eg, n-stearyl acrylate / ethyl methacrylate copolymer). And crystalline polymers having a long alkyl group in the side chain. Among these, more preferable are petroleum waxes such as paraffin wax and microcrystalline wax, and synthetic waxes.

  The content of the release agent is preferably 10 to 40% by mass, more preferably 10 to 30% by mass, further preferably 15 to 30% by mass, and particularly preferably 15 to 25% by mass. If the content rate of a mold release agent is 10 mass% or more, sufficient release property can be ensured and generation | occurrence | production of a hot offset can be prevented. On the other hand, if it is 40% by mass or less, the release agent is not exposed to the toner surface, and good fluidity and chargeability can be obtained.

In addition, if necessary, a lubricant or a charge control agent may be added to the toner of the present invention.
Examples of the lubricant that can be used include fatty acid amides such as ethylene bisstearylamide and oleic acid amide, and fatty acid metal salts such as zinc stearate and calcium stearate.

  The charge control agent is added to improve and stabilize the chargeability. For example, a dye composed of a complex such as a quaternary ammonium salt compound, a nigrosine compound, aluminum, iron, or chromium, or a triphenylmethane type Various commonly used charge control agents such as pigments can be used, but this affects the stability of the aggregated particles in the aggregation process and fusion / unification process when the toner is prepared by the emulsion aggregation method described later. From the standpoint of controlling ionic strength and reducing wastewater contamination, materials that are difficult to dissolve in water are preferred.

  In particular, as the charge control agent, metal salts of benzoic acid, metal salts of salicylic acid, metal salts of alkyl salicylic acid, metal salts of catechol, metal-containing bisazo dyes, tetraphenylborate derivatives, and the like used in powder toners. A compound selected from the group consisting of a quaternary ammonium salt and an alkylpyridinium salt, and a combination thereof can be preferably used.

  Further, when inorganic fine particles are added to the toner as a charge control agent, examples of such inorganic fine particles include silica, alumina, titania, calcium carbonate, magnesium carbonate, tricalcium phosphate and the like, which are usually outside the surface of the toner. Listed are all inorganic fine particles used as an additive. In this case, these inorganic fine particles can be used by being dispersed in a solvent using an ionic surfactant, a polymer acid, a polymer base or the like.

As described above, in the present invention, it is preferable that the toner particles contain organic crosslinked fine particles as an external additive.
The organic crosslinked fine particles are, for example, water or a dispersion medium containing water as a main component, a monomer having a polymerizable monomer such as a styrene monomer and two or more ethylenically unsaturated groups in the molecule ( It is obtained by drying an emulsion obtained by emulsion copolymerization with a crosslinking agent. The water used as the dispersion medium is preferably ion exchange water or pure water. The dispersion medium mainly composed of water means a mixed aqueous solution of water and an organic solvent such as methanol, a surfactant or an emulsifier, or a water-soluble polymeric protective colloid such as polyvinyl alcohol.

  The surfactant, emulsifier, protective colloid, and the like may be reactive or non-reactive as long as the achievement of the object of the present invention is not hindered. In addition, these surfactants, emulsifiers, protective colloids and the like may be used alone or in combination of two or more.

  Examples of the reactive surfactant include an anionic reactive surfactant and a nonionic reactive surfactant into which a radical polymerizable propenyl group has been introduced. These reactive surfactants may be used alone or in combination of two or more.

As the polymerizable monomer, those mentioned as the constituent components of the binder resin can be used in the same manner, and among them, a styrene monomer can be preferably used.
Examples of the styrene monomer include styrene, α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, 2 , 5-dimethylstyrene, 3,4-dimethylstyrene, 3,5-dimethylstyrene, 2,4,5-trimethylstyrene, 2,4,6-trimethylstyrene, pn-butylstyrene, pt-butyl Styrene, pn-hexyl styrene, pn-octyl styrene, pn-dodecyl styrene, p-methoxy styrene, p-phenyl styrene, p-chloro styrene, 3,4-dichlorostyrene, potassium styrene sulfonate Among them, styrene is preferably used. These styrenic monomers may be used alone or in combination of two or more.

  Further, as the cross-linking agent having two or more ethylenically unsaturated groups in the molecule, use of a large aliphatic one having about 10 to 40 carbon atoms in the main chain prevents unnecessary hardening, and toner It is possible to obtain organic crosslinked fine particles having appropriate elasticity that sufficiently function as a cushion between the photosensitive member and the photosensitive member.

As such an aliphatic crosslinking agent, (meth) acrylic acid esters of linear polyhydric alcohols, (meth) acrylic acid esters of substituted polyhydric alcohols; polyvinyl esters of polycarboxylic acids are used. be able to.
Specific examples include polyethylene glycol # 200 glycol diacrylate, polyethylene glycol # 400 glycol diacrylate, polyethylene glycol # 600 glycol diacrylate, polyethylene glycol # 1000 glycol diacrylate, 1,10-decanediol diacrylate, and the like.

  The content of the crosslinking agent is preferably in the range of 0.1 to 5% by mass of the whole monomer, more preferably in the range of 0.5 to 4.5% by mass, and 0.7 to 4.2. A range of mass% is more preferred. When the addition amount of the crosslinking agent is less than 0.1% by mass, the degree of crosslinking is lowered and the elasticity is insufficient, and when the addition amount exceeds 5% by mass, the organic fine particles are hardened to increase the stress on the photoreceptor. There is.

A polymerization initiator may be used to induce and accelerate emulsion copolymerization by radical polymerization reaction between the polymerizable monomer and the ethylenically unsaturated group-containing monomer.
Examples of the polymerization initiator include persulfates such as aqueous hydrogen peroxide, ammonium persulfate, potassium persulfate, and sodium persulfate. These polymerization initiators may be used alone or in combination of two or more.

The production method for obtaining the organic crosslinked fine particles in the present invention is not particularly limited. For example, the production from the emulsion may be performed by the following procedure.
In a reaction vessel such as a separable flask equipped with a stirrer, a nitrogen inlet tube and a reflux condenser, for example, water, a dispersion medium mainly containing water, a polymerizable monomer, and an ethylenically unsaturated group-containing monomer After heating up to about 70 ° C. under a constant stirring condition in an inert gas stream such as nitrogen gas, a polymerization initiator is added, and emulsion copolymerization by radical polymerization reaction is performed. Let it begin. Thereafter, the temperature of the reaction system is maintained at about 70 ° C., and the emulsion copolymerization is completed in about 24 hours, whereby a desired emulsion can be obtained.

For the purpose of adjusting pH, an alkali such as hydrochloric acid, acetic acid or other acids, or sodium hydroxide may be added to the emulsion after completion of the polymerization.
Subsequently, organic crosslinked fine particles can be obtained by drying the emulsion obtained above by a drying method such as a freeze drying method or a spray drying method.

  The organic crosslinked fine particles thus obtained preferably have a volume average particle size in the range of 80 to 300 nm, more preferably in the range of 100 to 250 nm. In general, inorganic fine particles are used as an external additive of the toner, but it is preferably about 1.5 to 10 times the particle size of the inorganic fine particles.

  When the volume average particle size of the organic crosslinked fine particles exceeds 300 nm, a spacer effect is obtained, but an excessive amount must be added to the toner, and the charging characteristics of the particles themselves may adversely affect the charging characteristics of the toner. There are adverse effects such as inevitable or free from the toner surface and causing contamination of the toner image holding member. If the volume average particle size is less than 80 nm, the particle size may be too small to obtain the spacer effect between the toner and the photoreceptor.

  The volume average particle size of the organic crosslinked particles is a volume average particle size obtained by measuring the particle distribution of fine particles in an emulsion diluted with ion-exchanged water or pure water using a particle size analyzer utilizing laser diffraction scattering. It is obtained as a diameter. Specific examples of the measuring device include a laser diffraction / scattering particle size distribution measuring device (HORIBA LA-910).

  Further, when the particle size distribution of the organic crosslinked fine particles is large and the standard deviation is D50v (volume average particle size) × 0.20 or more, the spacer effect cannot be sufficiently obtained unless the amount added to the toner is increased. If the amount added is increased, the above-mentioned adverse effects may occur.

The hardness of the organic crosslinked fine particles is usually correlated with the degree of crosslinking, and can be expressed, for example, by the size of the gel fraction indicating the degree of crosslinking. The gel fraction of the organic crosslinked fine particles in the present invention is preferably in the range of 30 to 60%.
The gel fraction was determined by adding about 0.3 g of dried fine particles in 30 g of an organic solvent, drying an undissolved material in the organic solvent with a vacuum dryer, measuring the mass thereof, and applying the following formula (7) Calculated by The organic solvent may be any organic solvent that can dissolve the polymer composed of the monomer, and examples thereof include tetrahydrofuran.
Gel fraction (% by mass) = (mass of fine particles undissolved in THF / mass of all fine particles) × 100 (7)

  The chargeability of the organic crosslinked fine particles in the present invention is preferably the same polarity as that of the toner. For example, when the toner is negatively charged and the organic cross-linked fine particles are positively charged, there is a problem that the addition of the organic cross-linked fine particles to the toner greatly reduces the charge. When toner is replenished, reverse polarity toner is likely to be generated. This is thought to be because the organic cross-linking fine particles that should be on the toner surface are slightly embedded in the toner bulk by stirring for a long time and the toner surface configuration changes, and the charge polarity of the toner and monodisperse resin particles is different.

  The charged polarity of the organic crosslinked fine particles can be measured using a powder charge amount measuring device (TB-200: manufactured by Toshiba Chemical Co., Ltd.) after mixing with a predetermined ferrite powder and charging it. The charging polarity of the toner can be measured similarly.

In addition to the above organic crosslinked fine particles, inorganic fine particles or organic fine particles may be added to the surface of the toner of the present invention by applying a shearing force in a dry state for the purpose of use as a flow aid or a cleaning aid. Can do.
Examples of the inorganic fine particles include all particles usually used as external additives on the toner surface, such as silica, alumina, titania, calcium carbonate, magnesium carbonate, tricalcium phosphate, and cerium oxide. Examples of the organic fine particles include all particles usually used as external additives on the toner surface, such as vinyl resins, polyester resins, and silicone resins.

The volume average particle size of the inorganic fine particles and organic fine particles is preferably in the range of 10 to 150 nm.
In particular, when inorganic fine particles are externally added to the toner, not only the toner particles themselves but also stress due to the inorganic fine particles that are external additives are likely to be generated on the photoreceptor, so that the spacer effect by the organic crosslinked fine particles is obtained. It will be necessary.

In the present invention, the total amount of external additives including organic crosslinked fine particles is preferably 2% by mass or more, more preferably 3% by mass or more. If it is less than 2% by mass, there may be insufficient voids and sufficient release of the release agent may not be obtained during fixing. In addition, as an upper limit of the total addition amount of an external additive, 10 mass% or less is preferable, More preferably, it is 8 mass% or less. Incidentally, the toner melting inhibition at the time of fixing can be solved by using a metal roll having a good thermal conductivity.
The ratio C / D between the addition amount C of the organic crosslinked fine particles and the addition amount D of the inorganic fine particles is preferably in the range of 0.4 to 0.8, and more preferably in the range of 0.4 to 0.65.

  The volume average particle diameter D50v of the toner of the present invention is preferably in the range of 4.0 to 10.0 μm, more preferably in the range of 5.0 to 8.0 μm, still more preferably 5.5 to 7 The range is 5 μm. If the thickness is 4.0 μm or more, it is possible to prevent the occurrence of cloud due to toner behavior. On the other hand, if it is 10.0 μm or less, a good quality image can be obtained.

The particle size distribution of the toner of the present invention is preferably such that the volume average particle size distribution index (GSDv) is 1.30 or less and the number average particle size distribution index (GSDp) is 1.40 or less. If GSDv is 1.30 or less and GSDp is 1.40 or less, a high-quality image can be obtained.
Further, the ratio (GSDv / GSDp) of the volume average particle size distribution index GSDv and the number average particle size distribution index GSDp is preferably 0.95 or more. However, when the volume distribution index GSDv exceeds 1.30, the resolution of the image may decrease, and the ratio of the volume average particle size distribution index GSDv to the number average particle size distribution index GSDp (GSDv / GSDp ) Is less than 0.95, toner chargeability may be reduced, toner scattering, fogging, and the like may occur, leading to image defects.

The values of the volume average particle system, the volume average particle size distribution index GSDv, and the number average particle size distribution index GSDp were measured and calculated as follows. First, the toner particle size distribution measured using a Coulter Counter TA II (manufactured by Beckman Coulter, Inc.) is cumulatively distributed from the smaller diameter side with respect to the divided particle size range (channel) in terms of the volume and number of individual toner particles. , And the particle diameter of 16% cumulative is defined as volume average particle diameter D16v and number average particle diameter D16p, and the particle diameter of 50% cumulative is defined as volume average particle diameter D50v and number average particle diameter D50p. It is defined as Similarly, particle diameters that are 84% cumulative are defined as volume average particle diameter D84v and number average particle diameter D84p. The volume average particle size distribution index (GSDv) is defined as (D84v / D16v) ^1/2 , and the number average particle size distribution index (GSDp) is calculated as (D84p / D16p) ^1/2 .

The toner of the present invention preferably has a surface property index value represented by the following formula (8) of 2 or less.
(Surface property index value) = (actual value of specific surface area) / (calculated value of specific surface area) (8)
However, in the formula (8), the calculated specific surface area is represented by 6Σ (n × R ² ) / {ρ × Σ (n × R ³ )}, where n is a Coulter The number of particles in the channel in the counter (number / channel) is represented, R represents the channel particle size (μm) in the Coulter counter, and ρ represents the toner density (g / μm ³ ). The number of divisions of the channel is 16. The size of the division is 0.1 interval on the log scale.

  Here, the surface property index value is preferably 2 or less, more preferably 1.8 or less. If it exceeds 2, the smoothness of the toner surface is impaired, and when an external additive is externally added to the toner surface, the external additive may be buried and the chargeability may be lowered.

  The specific surface area calculated value is determined by measuring the particle diameter of each channel of the Coulter counter and the number of particles of the particle diameter as shown in the above formula for calculating the specific surface area, It calculated | required in the form which considered distribution. Moreover, the specific surface area actual measurement value is measured based on the gas adsorption / desorption method, and is obtained by obtaining the Langmuir specific surface area. As a measuring device, Coulter SA3100 type (manufactured by Coulter, Inc.), Gemini 2360/2375 (manufactured by Shimadzu Corporation), or the like can be used.

Furthermore, the toner of the present invention preferably has a shape factor SF1 represented by the following formula (9) within a range of 120 to 135.
SF1 = (ML ² / A) × (π / 4) × 100 (9)
Here, ML represents the maximum toner length (μm), and A represents the toner projected area (μm ² ).

  When the shape factor SF1 is less than 120, a cleaning failure may be caused when residual toner is removed after the transfer process. If the shape factor SF1 exceeds 135, transferability may be impaired. Further, when toner is used as a developer, the toner may be destroyed due to collision with a carrier in the developing device. In this case, as a result, the fine powder increases or the release agent component exposed on the toner surface may contaminate the surface of the photoreceptor and impair the charging characteristics. May cause problems.

The shape factor SF1 was measured as follows using a Luzex image analyzer (manufactured by Nireco Corporation, LUZEX III).
First, an optical microscope image of the toner spread on the slide glass is taken into a Luzex image analyzer through a video camera, and the maximum length (ML) and projected area (A) of 50 or more toners are measured. The value of SF1 was obtained and averaged to obtain the shape factor SF1.

  Next, a method for producing the toner of the present invention will be described.

  The toner of the present invention includes at least the resin particles and a resin dispersion in which resin particles containing at least a binder resin are dispersed and a colorant dispersion obtained by dispersing a colorant. A metal element produced through an aggregation step of forming aggregated particles containing a colorant and a fusion step of fusing the aggregated particles by heating, wherein the mixed dispersion can have a valence of two or more. A surfactant having a sulfone group and a surfactant having a carboxyl group, the amount a (mol) of the surfactant having a sulfone group relative to 100 g of the binder resin solid content, and the binder resin The relationship with the amount b (mol) of the surfactant having a carboxyl group with respect to 100 g of the solid content satisfies the conditions of the above formula (3) and the above formula (4).

In the agglomeration step, if various particles such as resin particles and colorants dispersed in the mixed dispersion have ionicity, the particles repel each other and are difficult to agglomerate. By adjusting to a low pH and adjusting to a low pH state, various particles in the mixed dispersion are aggregated.
In this aggregating step, it is preferable to add an aggregating agent in order to obtain agglomerated particles stably and quickly, or with a narrower particle size distribution. As the aggregating agent, a metal ion capable of taking the above valence of 2 or more can be used.

  Although the amount of the flocculant added depends on the thickness of the shell layer, the flocculant containing trivalent metal ions is mixed with the flocculant containing divalent metal ions in an amount of 0.35% by mass or less of the total mixture. It is preferable that it is 0.1 mass% or more of the whole liquid.

  In particular, when a flocculant containing a trivalent metal ion is added in an amount exceeding 0.35% by mass, a large number of trivalent metal ions that are active as a flocculant also exist in the second aggregation step. The content of trivalent metal ions on the surface cannot be reduced, and a desired toner may not be obtained. Further, if the amount of the flocculant containing divalent metal ions is less than 0.1% by mass, the amount of the flocculant containing trivalent metal ions is originally small, so that the flocculant for forming the shell layer There may be a lack of strength to create a satisfactory shell layer.

  The surfactant described above is used for the purpose of stabilizing the dispersion of the resin particle dispersion, the colorant dispersion, and the release agent dispersion.

In the fusion step, the growth of the formed aggregated particles is stopped by increasing the pH of the mixed dispersion, and then the aggregated particles are fused by heat fusion.
In this fusing step, polyvalent carboxylic acid can be used for the purpose of preventing fusion between toners while controlling the shape of the toner.

  Specific examples of polyvalent carboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid Acid, citric acid, malic acid, trimellitic acid and the like can be mentioned. These polyvalent carboxylic acids are presumed to act as protective films that adhere to the surface of the toner and prevent fusion between the toners at the same time as adjusting the solution pH to a value necessary for controlling the toner shape.

Next, a suitable method for producing the toner of the present invention will be described in detail.
The aggregation process is divided into a first aggregation process and a second aggregation process.
In the first aggregation step, first, a resin particle dispersion, a colorant particle dispersion, and preferably a release agent particle dispersion are prepared. Resin particle dispersion is a known phase inversion emulsification, or resin particles containing a binder resin prepared by emulsion polymerization or the like, the surfactant having a sulfone group, the surfactant having a carboxyl group, And can be prepared by dispersing in a solvent.

  The colorant particle dispersion is prepared by dispersing colorant particles having a desired color in a solvent using an ionic surfactant having a polarity opposite to that of the surfactant used for preparing the resin particle dispersion. In addition, the release agent particle dispersion allows the release agent to be dispersed in water together with a polymer electrolyte such as an ionic surfactant, a polymer acid, or a polymer base, heated above the melting point, and subjected to strong shearing. It is prepared by making fine particles with a homogenizer or a pressure discharge type disperser.

  Next, a resin particle dispersion, a colorant particle dispersion, a release agent particle dispersion, and a metal ion capable of taking a valence of 2 or more are contained as metal ions capable of taking a valence of 2 or more. Aggregated particles containing resin particles, colorant particles, and release agent particles having a diameter that is close to a desired toner diameter by mixing aggregating agent and heteroaggregating resin particles, colorant particles, and release agent particles (Core aggregated particles) are formed.

  The second aggregating step includes a resin particle dispersion containing the second resin particles on the surface of the core agglomerated particles obtained in the first aggregating step, and metal ions capable of taking a valence of 2 or more. A core layer in which a shell layer is formed on the surface of the core aggregated particles by attaching the second resin particles to form a coating layer (shell layer) having a desired thickness using Aggregated particles having a shell structure (core / shell aggregated particles) are obtained.

  In addition, the 2nd resin particle used in this case may be the same as the said resin particle, and may differ.

  The particle diameters of the resin particles, the second resin particles, the colorant particles, and the release agent particles used in the first and second aggregating steps are adjusted to a desired value for the toner diameter and the particle size distribution. In order to make it easy, it is preferably 1 μm or less, and more preferably in the range of 100 to 300 nm.

  In the core / shell structure of the aggregated particles, the thickness of the shell layer is not particularly limited, but is preferably in the range of 150 to 300 nm. When the thickness of the shell layer is less than 150 nm, the release agent may flow out to the toner surface, and the discharged release agent may contaminate the photoreceptor or the like as a result. Further, when the thickness of the shell layer exceeds 300 nm, the slurry internal viscosity in the step of forming the core component decreases, and the number of resin particles added at the time of shell formation increases rapidly, so the internal slurry viscosity Greatly increases, the particle size and particle size distribution may deteriorate during shell formation. Further, fine particles are likely to be generated during the shell formation, and toner production problems such as clogging when the toner slurry containing such residual resin particles is solid-liquid separated and removed with a filter or the like are likely to occur. There is a case.

  In addition, the 1st and 2nd aggregation process may be repeatedly performed in several steps dividedly.

  Next, in the fusion step, the glass transition of the first or second resin particles contained in the core / shell aggregated particles in the core / shell aggregated particles obtained through the second aggregation step is performed in a solution. The toner particles are obtained by heating above the temperature (the glass transition temperature of the resin having the highest glass point transition temperature when there are two or more types of resin) and fusing.

After the fusion process, the toner particles formed in the solution are converted into toner particles that have been dried through a known washing process, solid-liquid separation process, and drying process.
In addition, it is preferable that the washing | cleaning process performs substitution washing | cleaning by ion-exchange water fully from a charging point. The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration, and the like are preferably used from the viewpoint of productivity. Further, although the drying process is not particularly limited, freeze drying, flash jet drying, fluidized drying, vibration fluidized drying and the like are preferably used from the viewpoint of productivity.

<Electrostatic latent image developer>
The electrostatic latent image developer of the present invention is not particularly limited except that it contains the electrostatic charge developing toner of the present invention, and can have an appropriate component composition depending on the purpose. The electrostatic latent image developer in the present invention becomes a one-component electrostatic latent image developer when the electrostatic charge developing toner is used alone, and a two-component electrostatic latent image when used in combination with a carrier. Becomes a developer.

  For example, in the case of using a carrier, the carrier is not particularly limited, and examples thereof include known carriers. For example, resins described in JP-A Nos. 62-39879 and 56-11461 are disclosed. Known carriers such as a coated carrier can be used.

  Specific examples of the carrier include the following resin-coated carriers. Examples of the core particle of the carrier include normal iron powder, ferrite, magnetite molding, and the like, and the volume average particle size is in the range of about 30 to 200 μm.

  Examples of the coating resin for the resin-coated carrier include styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, lauryl acrylate, acrylic acid 2 -Α-methylene fatty acid monocarboxylic acids such as ethylhexyl, methyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate; nitrogen-containing acrylics such as dimethylaminoethyl methacrylate; acrylonitrile, methacrylonitrile, etc. Vinyl nitriles; vinyl pyridines such as 2-vinyl pyridine and 4-vinyl pyridine; vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl Homopolymers such as vinyl ketones such as ketones; olefins such as ethylene and propylene; vinyl-based fluorine-containing monomers such as vinylidene fluoride, tetrafluoroethylene and hexafluoroethylene; and copolymers comprising two or more types of monomers Furthermore, silicone resins containing methyl silicone, methyl phenyl silicone, etc., polyesters containing bisphenol, glycol, etc., epoxy resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, polycarbonate resins and the like can be mentioned. These resins may be used alone or in combination of two or more. The coating amount of the coating resin is preferably in the range of about 0.1 to 10 parts by mass, more preferably in the range of 0.5 to 3.0 parts by mass with respect to 100 parts by mass of the core particles.

  For the production of the carrier, a heating kneader, a heating Henschel mixer, a UM mixer, or the like can be used. Depending on the amount of the coating resin, a heating fluidized rolling bed, a heating kiln, or the like can be used. .

  The mixing ratio of the electrostatic charge developing toner of the present invention and the carrier in the two-component electrostatic image developer is not particularly limited and may be appropriately selected depending on the intended purpose.

<Image Forming Apparatus and Image Forming Method>
Next, an image forming apparatus and an image forming method using the toner of the present invention will be described.

As shown in FIG. 2, the image forming apparatus 82 of the present invention includes the electrophotographic photoreceptor 80 that rotates in a predetermined direction (the direction of arrow D in FIG. 2).
In the vicinity of the electrophotographic photoreceptor 80, a charging device 84, an exposure device 86, a developing device 88, a transfer device 89, a charge eliminating device 81, and a cleaning member 87 are provided along the rotation direction of the electrophotographic photoreceptor 80. It has been.

  The charging device 84 charges the surface of the electrophotographic photoreceptor 80 to a predetermined potential. The exposure device 86 exposes the surface of the electrophotographic photoreceptor 80 charged by the charging device 84 to form an electrostatic latent image corresponding to the image data.

The developing device 88 stores in advance the developer containing the toner of the present invention as a developer containing toner for developing the electrostatic latent image, and supplies the stored developer to the surface of the electrophotographic photoreceptor 80. Thus, the electrostatic latent image is developed to form a toner image.
The transfer device 89 transfers the toner image formed on the electrophotographic photoreceptor 80 to the recording medium 83 by sandwiching and transporting the recording medium 83 with the electrophotographic photoreceptor 80. The toner image transferred to the recording medium 83 is fixed on the surface of the recording medium 83 by a fixing device (not shown).

  The static eliminator 81 neutralizes the charged deposit adhered to the surface of the electrophotographic photoreceptor 80. The cleaning member 87 is provided so as to come into contact with the surface of the electrophotographic photoreceptor 80 and removes surface deposits by frictional force with the surface of the electrophotographic photoreceptor 80.

  The image forming apparatus 82 of the present invention may be a so-called tandem machine having a plurality of electrophotographic photoreceptors 80 corresponding to the toners of the respective colors. The transfer of the toner image to the recording medium 83 may be an intermediate transfer method in which the toner image formed on the surface of the electrophotographic photoreceptor 80 is transferred to the intermediate transfer body and then transferred to the recording medium.

  The surface of the electrophotographic photoreceptor 80 rotating in a predetermined direction (the direction of arrow D in FIG. 2) is uniformly charged by the charging device 84. The exposure device 86 forms an electrostatic latent image corresponding to the image data on the surface of the electrophotographic photoreceptor 80 whose surface is uniformly charged. When the area where the electrostatic latent image is formed on the electrophotographic photoreceptor 80 reaches the area facing the developing device 88, the electrostatic latent image is developed by the developer stored in the developing device 88. As described above, the electrostatic latent image is developed by the developer, whereby a toner image corresponding to the electrostatic latent image is formed on the electrophotographic photoreceptor 80.

  When the area of the toner image formed on the electrophotographic photoreceptor 80 reaches the area facing the transfer device 89 due to the rotation of the electrophotographic photoreceptor 80, the toner image is transferred to the recording medium 83 in this area. Is done. When the recording medium 83 is conveyed by a conveyance roller (not shown) and reaches the installation position of the fixing device 90, the toner image transferred onto the recording medium 83 is heated and pressurized by the fixing device 90 to be recorded. It is fixed on the medium 83.

  According to the image forming apparatus 82 of the present invention, since the toner having good chargeability is used, even when the image forming process is performed in the image forming apparatus 82, the image quality deterioration due to the decrease in the chargeability of the toner is caused. Can be suppressed.

  Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto. In the examples, “parts” and “%” mean “parts by weight” and “% by weight” unless otherwise specified.

<Measuring method of various characteristics>
First, methods for measuring physical properties of toners and the like used in Examples and Comparative Examples will be described.
(Toner particle size and particle size distribution measurement method)
In the present invention, the toner particle size and particle size distribution were measured using a Coulter Counter TA-II type (manufactured by Beckman-Coulter) as the measuring device, and ISOTON-II (manufactured by Beckman-Coulter) as the electrolyte.

  As a measurement method, 0.5 to 50 mg of a measurement sample is added to 2 ml of a 5% aqueous solution of a surfactant, preferably sodium alkylbenzenesulfonate, as a dispersant. This was added to 100 to 150 ml of the electrolytic solution. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 minute, and the particle size distribution of particles of 2 to 60 μm is measured using the Coulter counter TA-II type with an aperture diameter of 100 μm. The volume average particle diameter, GSDv, and GSDp were determined as described above. The number of particles to be measured was 50,000.

(Volume average particle size of binder resin particles, colorant particles, etc.)
The volume average particle diameter of binder resin particles, colorant particles, etc. is measured using a Coulter Counter TA-II type (manufactured by Beckman-Coulter) when the particle diameter to be measured is 2 μm or more, and the electrolyte is ISOTON. The particle size was measured using -II (Beckman-Coulter).

  As a measuring method, 0.5 to 50 mg of a measurement sample was added to 2 ml of a 5% aqueous solution of a surfactant, preferably sodium alkylbenzenesulfonate as a dispersant, and this was added to 100 to 150 ml of the electrolytic solution. The electrolytic solution in which the measurement sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 minute. Using the Coulter Counter TA-II type, an aperture having an aperture diameter of 100 μm is used. The particle size distribution of particles in the range of 60 μm was measured. The number of particles to be measured was 50,000.

  For the divided particle size range (channel), the measured particle size distribution is drawn from the small diameter side for each volume and number, and the particle size that is 16% cumulative by volume is accumulated by volume average particle size D16v and number. The cumulative number particle diameter of 16% is defined as D16p. Similarly, a particle diameter that is 50% cumulative in volume is defined as a volume average particle diameter D50v, and a particle diameter that is cumulative 50% in number is defined as a number average particle diameter D50p. Similarly, a particle diameter that is 84% cumulative in volume is defined as a volume average particle diameter D84v, and a cumulative number particle diameter that is 84% cumulative in number is defined as D84p. The volume average particle diameter is the D50v.

Using these, the volume average particle size distribution index (GSDv) is calculated from (D84v / D16v) ^1/2 , the number average particle size index (GSDp) is calculated from (D84p / D16p) ^1/2 , and the small diameter side number average The particle size index (lower GSDp) is calculated by {(D50p) / (D16p)}.

  On the other hand, when the particle diameter to be measured was less than 2 μm, the particle size was measured using a laser diffraction particle size distribution analyzer (LA-700: manufactured by Horiba, Ltd.). As a measurement method, a sample in a dispersion is adjusted to have a solid content of about 2 g, and ion exchange water is added thereto to make about 40 ml. This is put into the cell until an appropriate concentration is reached, waits for about 2 minutes, and is measured when the concentration in the cell becomes almost stable. The obtained volume average particle diameter for each channel was accumulated from the smaller volume average particle diameter, and the volume average particle diameter was determined to be 50%.

  When measuring powders such as external additives, 2 g of a measurement sample is added to 50 ml of a 5% aqueous solution of a surfactant, preferably sodium alkylbenzenesulfonate, and 2 with an ultrasonic disperser (1,000 Hz). A sample was prepared by dispersing for a minute, and the measurement was performed in the same manner as the above dispersion.

[Example A]
(Preparation of amorphous polyester resin dispersion (A1))
In a heat-dried flask, 35 mol parts of polyoxyethylene (2,0) -2,2-bis (4-hydroxyphenyl) propane and polyoxypropylene (2,2) -2,2-bis (4-hydroxy) were added. Phenyl) propane 65 mol part, terephthalic acid 80 mol part, n-dodecenyl succinic acid 10 mol part, isophthalic acid 10 mol part, and the total number of moles of these acid components (terephthalic acid, n-dodecenyl succinic acid, isophthalic acid) ) And 0.05 mol part of dibutyltin oxide is introduced, nitrogen gas is introduced into the container and kept in an inert atmosphere, the temperature is raised, and then a copolycondensation reaction is carried out at 150 to 230 ° C. for about 12 hours. Thereafter, the pressure was gradually reduced at 210 to 250 ° C. to synthesize an amorphous polyester resin (1). By molecular weight measurement (polystyrene conversion) by gel permeation chromatography, the resulting amorphous polyester resin (1) has a weight average molecular weight (Mw) of 15400, a number average molecular weight (Mn) of 6800, and a glass transition point of It was 65 ° C.

Next, 100 parts by weight of this amorphous polyester resin (A1) and 585 parts by weight of deionized water were placed in a stainless beaker, placed in a warm bath, and heated to 95 ° C. When the amorphous polyester resin (A1) was melted, it was stirred at 8000 rpm using a homogenizer (manufactured by IKA: Ultra Tarrax T50), and at the same time, diluted ammonia water was added to adjust the pH to 7.0.
Next, the emulsion was dispersed while adding 20 parts by weight of an aqueous solution obtained by diluting 4 parts by weight of an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK), and an amorphous material having a volume average particle size of 0.2 μm. A polyester resin dispersion (A1) [resin particle concentration: 30%] was prepared.

(Adjustment of colorant dispersion)
・ Carbon black (trade name, Legal 330, manufactured by Cabot Corporation) 100 parts ・ Anionic surfactant (trade name, Neogen RK, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 10 parts ・ Ion-exchanged water 390 parts

  The above components were mixed and subjected to a dispersion treatment at 75 ° C. for 30 minutes with a homogenizer (Ultra Turrax, manufactured by IKA) to obtain a colorant dispersion (A1) having a volume average particle size of 250 nm.

(Adjustment of release agent dispersion)
-Paraffin wax (Nippon Seiwa Co., Ltd., trade name HNP-9) 100 parts-Anionic surfactant (Lion Corporation, trade name Ripar 860K) 10 parts-Ion-exchanged water 390 parts

The above components were mixed, pre-dispersed for 10 minutes with a homogenizer (Ultra Turrax, manufactured by IKA), and then subjected to a dispersion treatment at 300 kg / cm ² for 60 minutes using a pressure jet mill (Gorin homogenizer, manufactured by Gorin). Was performed at 110 ° C. to obtain a release agent particle dispersion having a volume average particle size of 220 nm.

(Production of toner particles)
-Toner particles (A1)-
Amorphous polyester resin dispersion (A1): 220 parts by weight Surfactant having a sulfone group (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK sodium dodecylbenzenesulfonate): 0 for 100 g of polyester resin solid content .0025 mol
-Carboxyl group-containing surfactant (Kao Corporation: OS soap potassium oleate): 0.018 mol added to 100 g of polyester resin solid content-Pigment dispersion B-1: 30 parts by weight-Release agent dispersion (1): 60 parts by weight ・ Ion exchange water: 400 parts by weight

The above was placed in a round stainless steel flask, adjusted to pH 3 with nitric acid, and mixed and dispersed for 5 minutes with a homogenizer (manufactured by IKA: Ultra Turrax T50).
Next, 0.16 part by weight of polyaluminum chloride was added thereto, and the dispersing operation was continued for 8 minutes with the ultra turrax. Further, the flask was heated to 48 ° C. with stirring in an oil bath for heating, and kept at 48 ° C. for 60 minutes.

Next, 53.3 parts by weight of the amorphous polyester resin dispersion (A1) was gradually added to the round stainless steel flask.

  After further holding at 48 ° C. for 1 hour, 0.5 mol / L aqueous sodium hydroxide solution was added to adjust the pH of the solution to 9.0, and then the stainless steel flask was sealed and stirred using a magnetic seal. While continuing, it was heated to 90 ° C. and held for 3 hours.

  After holding for 3 hours (after completion of the reaction), after the stirring was stopped, the solution in the flask was immediately cooled using a heat exchanger. The temperature lowering rate at this time was 15 ° C./min.

Subsequently, the solution in the flask was filtered and thoroughly washed with ion exchange water, and then solid-liquid separation was performed by Nutsche suction filtration. This was further redispersed in 3 L of ion exchanged water at 40 ° C., and stirred and washed at 300 rpm for 15 minutes. This operation was further repeated five times. When the pH of the filtrate was 7.00, the electric conductivity was 8.8 μS / cm, and the surface tension was 71.0 Nm, solid-liquid separation was performed using No5A filter paper by Nutsche suction filtration. Next, vacuum drying was continued for 12 hours to obtain toner particles (A1).

  When the amount a (mol) of the surfactant having a sulfone group with respect to 100 g of the solid content of the amorphous polyester resin contained in the toner particles (A1) was measured, it was 0.0022 mol. Moreover, it was 0.015 mol when the quantity b (mol) of surfactant which has a carboxyl group with respect to 100 g of amorphous polyester resin solid content was measured. In addition, 1.62 × a + b was 0.0186.

-Production of toner particles (A2)-
(Production of toner particles)
Surfactant having a sulfone group in the toner particles (A1) (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK sodium dodecylbenzenesulfonate): Surfactant having a carboxyl group of 0.0017 mol per 100 g of polyester resin solid content (Kao Co., Ltd .: OS soap potassium oleate): Toner particles (A2) were produced in the same manner as toner particles (A1) except that the amount was changed to 0.020 mol based on 100 g of polyester resin solids.
When the amount a (mol) of the surfactant having a sulfone group with respect to 100 g of the solid content of the amorphous polyester resin contained in the toner particles (A2) was measured, it was 0.0016 mol. Moreover, it was 0.018 mol when the quantity b (mol) of the surfactant which has a carboxyl group with respect to 100 g of amorphous polyester resin solid content was measured. In addition, 1.62 × a + b was 0.0206.

-Production of toner particles (A3)-
(Production of toner particles)
Surfactant having a sulfone group in the toner particles (A1) (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK sodium dodecylbenzenesulfonate): Surfactant having a carboxyl group of 0.0068 mol per 100 g of polyester resin solid content (Kao Co., Ltd .: OS soap potassium oleate): Toner particles (A3) were produced in the same manner as toner particles (A1) except that the amount was changed to 0.016 mol based on 100 g of polyester resin solid content.
When the amount a (mol) of the surfactant having a sulfone group with respect to 100 g of the solid content of the amorphous polyester resin contained in the toner particles (A3) was measured, it was 0.0058 mol. Moreover, it was 0.013 mol when the quantity b (mol) of surfactant which has a carboxyl group with respect to 100 g of amorphous polyester resin solid content was measured. In addition, 1.62 × a + b was 0.0224.

-Production of toner particles (A4)-
(Production of toner particles)
Surfactant having a sulfone group in the toner particles (A1) (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK sodium dodecylbenzenesulfonate): Surfactant having a carboxyl group of 0.005 mol per 100 g of polyester resin solid content (Kao Co., Ltd .: OS soap potassium oleate): Toner particles (A4) were produced in the same manner as toner particles (A1) except that the amount was changed to 0.015 mol with respect to 100 g of polyester resin solids.
When the amount a (mol) of the surfactant having a sulfone group with respect to 100 g of the solid content of the amorphous polyester resin contained in the toner particles (A4) was measured, it was 0.004 mol. Moreover, it was 0.012 mol when the quantity b (mol) of surfactant which has a carboxyl group with respect to 100 g of amorphous polyester resin solid content was measured. In addition, 1.62 × a + b was 0.0185.

-Production of toner particles (A5)-
(Production of toner particles)
Surfactant having a sulfone group in the toner particles (A1) (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK sodium dodecylbenzenesulfonate): surfactant having a carboxyl group of 0.0027 mol per 100 g of polyester resin solid content (Kao Co., Ltd .: OS soap potassium oleate): Toner particles (A5) were produced in the same manner as toner particles (A1) except that the amount was changed to 0.018 mol with respect to 100 g of polyester resin solid content.
When the amount a (mol) of the surfactant having a sulfone group with respect to 100 g of the solid content of the amorphous polyester resin contained in the toner particles (A5) was measured, it was 0.015 mol. Moreover, it was 0.015 mol when the quantity b (mol) of surfactant which has a carboxyl group with respect to 100 g of amorphous polyester resin solid content was measured. In addition, 1.62 × a + b was 0.0393.

-Production of toner particles (A6)-
(Production of toner particles)
Surfactant having a sulfone group in the toner particles (A1) (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK sodium dodecylbenzenesulfonate): Surfactant having a carboxyl group of 0.0018 mol per 100 g of polyester resin solid content (Kao Co., Ltd .: OS soap potassium oleate): Toner particles (A6) were produced in the same manner as toner particles (A1) except that the amount was changed to 0.028 mol based on 100 g of polyester resin solids.
When the amount a (mol) of the surfactant having a sulfone group with respect to 100 g of the solid content of the amorphous polyester resin contained in the toner particles (A6) was measured, it was 0.0013 mol. Moreover, it was 0.025 mol when the quantity b (mol) of surfactant which has a carboxyl group with respect to 100 g of amorphous polyester resin solid content was measured. In addition, 1.62 × a + b was 0.0272.

-Production of toner particles (A7)-
(Production of toner particles)
Surfactant having a sulfone group in the toner particles (A1) (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK sodium dodecylbenzenesulfonate): Surfactant having a carboxyl group, 0.008 mol per 100 g of polyester resin solid content (Kao Co., Ltd .: OS soap potassium oleate): Toner particles (A7) were produced in the same manner as toner particles (A1) except that the amount was changed to 0.020 mol based on 100 g of polyester resin solid content.
When the amount a (mol) of the surfactant having a sulfone group with respect to 100 g of the solid content of the amorphous polyester resin contained in the toner particles (A7) was measured, it was 0.006 mol. Moreover, it was 0.016 mol when the quantity b (mol) of surfactant which has a carboxyl group with respect to 100 g of amorphous polyester resin solid content was measured. In addition, 1.62 × a + b was 0.0257.

-Production of toner particles (A8)-
(Production of toner particles)
Surfactant having a sulfone group in the toner particles (A1) (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK sodium dodecylbenzenesulfonate): Surfactant having a carboxyl group of 0.004 mol per 100 g of polyester resin solid content (Kao Co., Ltd .: OS soap potassium oleate): Toner particles (A8) were produced in the same manner as toner particles (A1) except that the amount was changed to 0.01 mol with respect to 100 g of polyester resin solids.
When the amount a (mol) of the surfactant having a sulfone group with respect to 100 g of the solid content of the amorphous polyester resin contained in the toner particles (A8) was measured, it was 0.003 mol. Moreover, it was 0.008 mol when the quantity b (mol) of surfactant which has a carboxyl group with respect to 100 g of amorphous polyester resin solid content was measured. In addition, 1.62 × a + b was 0.0129.

-Production of toner particles (A9)-
(Production of toner particles)
Surfactant having a sulfone group in the toner particles (A1) (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK sodium dodecylbenzenesulfonate): Surfactant having a carboxyl group of 0.0015 mol per 100 g of polyester resin solid content (Kao Co., Ltd .: OS soap potassium oleate): Toner particles (A9) were produced in the same manner as toner particles (A1) except that the amount was changed to 0.01 mol with respect to 100 g of polyester resin solid content.
When the amount a (mol) of the surfactant having a sulfone group with respect to 100 g of the solid content of the amorphous polyester resin contained in the toner particles (A9) was measured, it was 0.0010 mol. Moreover, it was 0.008 mol when the quantity b (mol) of surfactant which has a carboxyl group with respect to 100 g of amorphous polyester resin solid content was measured. Further, 1.62 × a + b was 0.0016.

-Production of toner particles (A10)-
(Production of toner particles)
Surfactant having a sulfone group in the toner particles (A1) (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK sodium dodecylbenzenesulfonate): Surfactant having a carboxyl group of 0.0015 mol per 100 g of polyester resin solid content (Kao Co., Ltd .: OS soap potassium oleate): Toner particles (A10) were produced in the same manner as toner particles (A1) except that the amount was changed to 0.025 mol with respect to 100 g of polyester resin solids.
When the amount a (mol) of the surfactant having a sulfone group with respect to 100 g of the solid content of the amorphous polyester resin contained in the toner particles (A10) was measured, it was 0.0010 mol. Moreover, it was 0.021 mol when the quantity b (mol) of surfactant which has a carboxyl group with respect to 100 g of amorphous polyester resin solid content was measured. In addition, 1.62 × a + b was 0.0226.

-Production of toner particles (A11)-
(Production of toner particles)
Surfactant having a sulfone group in the toner particles (A1) (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK sodium dodecylbenzenesulfonate): 0.01 mol per 100 g of polyester resin solid content and a surfactant having a carboxyl group Toner particles (A11) were produced in the same manner as toner particles (A1) except that the agent (Kao Corporation: OS soap potassium oleate) was not added.
When the amount a (mol) of the surfactant having a sulfone group with respect to 100 g of the solid content of the amorphous polyester resin contained in the toner particles (A11) was measured, it was 0.008 mol. In addition, 1.62 × a + b was 0.0130.

-Production of toner particles (A12)-
(Production of toner particles)
The surfactant having a sulfone group in the toner particles (A1) was removed, and the surfactant having a carboxyl group (Kao Corporation: OS soap, potassium oleate) was changed to 0.05 mol with respect to 100 g of polyester resin solid content. Except for the above, toner particles (A12) were produced in the same manner as toner particles (A1).
When the amount b (mol) of the surfactant having a carboxyl group with respect to 100 g of the solid content of the amorphous polyester resin contained in the toner particles (A12) was measured, it was 0.044 mol. In addition, 1.62 × a + b was 0.044.

<Preparation of developer>
To 50 parts of the above toner particles, 2.5 parts of hydrophobic silica (TS720, manufactured by Cabot) is added as an external additive, blended at 30 ° C., 3000 rpm, 5 minutes using a Henschel mixer, and externally added. Each toner was obtained.
On the other hand, 11 parts of toluene, 2 parts of diethylaminoethyl methacrylate-styrene-methyl methacrylate copolymer (copolymerization ratio: 2/20/78, weight average molecular weight: 50,000), carbon black (manufactured by Cabot Corporation, R330R) 0. Two parts and glass beads (particle size: 1 mm, the same amount as toluene) were put into a sand mill manufactured by Kansai Paint Co., Ltd., and stirred at a rotational speed of 1200 rpm for 30 minutes to prepare a coating resin layer forming solution.

Next, 100 parts of this coating resin layer forming solution and Mn—Mg ferrite particles (true specific gravity: 4.6 g / cm ³ , volume average particle size: 35 μm, saturation magnetization: 65 emu / g) are vacuum degassed kneader. The mixture was stirred for 10 minutes while maintaining the temperature at 60 ° C., and then the pressure was reduced and toluene was distilled off to obtain a ferrite carrier having a coating resin layer formed thereon.
To this ferrite carrier, the toner is mixed so that the toner concentration (the ratio of the toner in the developer to the total amount of developer 100) is 5%, stirred and mixed in a ball mill for 5 minutes, and the toner particles ( Developers (A1) to (A12) each containing A1) to (A12) were prepared.

<Example A1>
Using the developer A1 as described above, a modified DocuCentre Color 400CP printer manufactured by Fuji Xerox Co., Ltd. as an image forming apparatus, and an evaluation image at a process speed of 160 mm in an environment of high temperature and high humidity (28 ° C., 85% RH). / Sec and a fixing roll temperature of 180 ° C., 3000 sheet image forming processing was performed, and evaluation was performed according to the following criteria.
In the image formation, S paper (manufactured by Fuji Xerox Co., Ltd.) was used as the paper.
Further, as the evaluation image, an image obtained by outputting a halftone image with a toner loading of 0.2 g / cm ^{2 on} the entire surface of the A3 size paper is used.

-Image evaluation-
The toner density was adjusted to 5% for every 1000 sheets, and the halftone image to be output was visually evaluated according to the following criteria for the density of the density generated in the image.
-Image evaluation criteria-
A: When there is no difference in image density between the 3000th image and the 1st image.
○: There is no problem with 2000 sheets, and there is a difference in image density between the 3000th image and the 1st sheet.
Δ: When there is no problem with 1000 sheets, there is a difference in image density between the 2000th image and the first image.
×: When 1000 images have a difference in image density compared to the first image.
The above evaluation results are shown in Table 1.

<Example A2 to Example A4, Comparative Example A1 to Comparative Example A8>
Example A2 to Example A4 and Comparative Example A1 to Comparative Example A8 were carried out using the developer (A2) to developer (A12) prepared above instead of the developer (A1) in Example A1. The actual machine evaluation similar to Example A1 was performed.
The evaluation results are shown in Table 1.

As shown in Example A1 to Example A4 shown in Table 1, it can be seen that the halftone image density is maintained even under conditions where the number of output sheets is large.
On the other hand, in the developers used in Comparative Examples A1 to A8, it can be seen that there is a problem in the halftone image density compared to the initial image. This shows that even if the charge amount is the same as the initial toner density on the 1000th sheet, it is different from the initial value, and there is a problem in maintainability.

[Example B]
(Adjustment of amorphous polyester resin B1)
Acid component, terephthalic acid ... 29.8 mol% (37.7 wt%)
・ Fumaric acid 70 mol% (61.9 wt%)
-Sodium dimethyl-5-sulfonate isophthalate-0.2 mol% (0.5 wt%)
Alcohol component, bisphenol A ethylene oxide 2 mol adduct, 20 mol% (18.5 wt%)
-Bisphenol A propylene oxide 2 mol adduct-80 mol% (81.5 wt%)
The above components were put into a reaction vessel equipped with a stirrer, a thermometer, a condenser, and a nitrogen gas introduction tube. After the inside of the reaction vessel was replaced with dry nitrogen gas, 0.04 mol of dibutyltin oxide (reagent) was added and nitrogen gas was introduced. The reaction was stirred at about 195 ° C. for about 6 hours under an air stream. Furthermore, the inside of the reaction vessel was depressurized to 10.0 mmHg, and stirred and reacted for about 0.5 hours under reduced pressure to obtain an amorphous polyester resin B1.

(Adjustment of amorphous polyester resin B2)
Acid component, terephthalic acid ... 29.5 mol% (37.2 wt%)
・ Fumaric acid 70 mol% (61.7 wt%)
-Sodium dimethyl-5-sulfonate isophthalate-0.5 mol% (1.1 wt%)
Alcohol component · Bisphenol A ethylene oxide 2mol adduct · · 20mol% (18.5wt%)
-Bisphenol A propylene oxide 2 mol adduct-80 mol% (81.5 wt%)
The above components were put in a reaction vessel equipped with a stirrer, a thermometer, a condenser, and a nitrogen gas introduction tube, and reacted under the same conditions as the amorphous polyester resin B1 to obtain an amorphous polyester resin B2.

(Adjustment of amorphous polyester resin B3)
Acid component, terephthalic acid ... 80.0 mol% (79.4 wt%)
・ Isophthalic acid 19 mol% (18.9 wt%)
-Sodium dimethyl-5-sulfonate isophthalate-1 mol% (1.8 wt%)
Alcohol component-Bisphenol A ethylene oxide 2 mol adduct-80 mol% (95.1 wt%)
・ Ethylene glycol: 20 mol% (4.9% by weight)
The above components were put in a reaction vessel equipped with a stirrer, a thermometer, a condenser, and a nitrogen gas introduction tube, and reacted under the same conditions as the amorphous polyester resin B1 to obtain an amorphous polyester resin B2.

(Adjustment of amorphous polyester resin B4)
Acid component, terephthalic acid 30.0 mol% (38.0 wt%)
・ Fumaric acid 70 mol% (62.0 wt%)
Alcohol component · Bisphenol A ethylene oxide 2mol adduct · · 20mol% (18.5wt%)
-Bisphenol A propylene oxide 2 mol adduct-80 mol% (81.5 wt%)
The above components were put in a reaction vessel equipped with a stirrer, a thermometer, a condenser, and a nitrogen gas introduction tube, and reacted under the same conditions as the amorphous polyester resin B1 to obtain an amorphous polyester resin B2.

(Adjustment of amorphous polyester resin B5)
Acid component, terephthalic acid ... 28.4 mol% (35.4 wt%)
・ Fumaric acid 70 mol% (61.0 wt%)
-Sodium dimethyl-5-sulfonate isophthalate-1.6 mol% (3.6 wt%)
Alcohol component · Bisphenol A ethylene oxide 2mol adduct · · 20mol% (18.5wt%)
-Bisphenol A propylene oxide 2 mol adduct-80 mol% (81.5 wt%)
The above components were put in a reaction vessel equipped with a stirrer, a thermometer, a condenser, and a nitrogen gas introduction tube, and reacted under the same conditions as the amorphous polyester resin B1 to obtain an amorphous polyester resin B2.

  Table 2 shows materials constituting the amorphous polyester resin B1 to the amorphous polyester resin B5.

[Preparation of Amorphous Polyester Resin Dispersion B1]
The obtained amorphous polyester resin B1 was dispersed using a disperser in which Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) was modified to a high temperature and high pressure type. Charged at a composition ratio of 70% by weight of ion-exchanged water and 30% by weight of amorphous polyester resin B1,
As a surfactant having a sulfone group with respect to 100 g of the amorphous polyester resin solid content, 2.0% by weight (0.0058 mol) of linear alkylbenzene sulfonate sodium (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK) is added. At the same time, 3.2 wt% (0.011 mol) of sodium stearate having a carboxyl group (manufactured by Wako Pure Chemical Industries, Ltd.) having a carboxyl group was added to 100 g of solid content of amorphous polyester resin B1.

  Furthermore, by adjusting the pH to 8.8 with dilute ammonia water, operating the Cavitron under the conditions of a rotor rotation speed of 60 Hz, a pressure of 0.5 MPa, and heating by a heat exchanger at 140 ° C., an amorphous property A polyester resin dispersion B1 was obtained. The particle size distribution of the particles in the amorphous polyester resin dispersion was measured using a microtrack (manufactured by Nikkiso Co., Ltd., Microtrack UPA9340).

  The volume average particle diameter of the amorphous polyester resin particles in the obtained amorphous polyester resin dispersion B1 was 210 μm.

[Preparation of Amorphous Polyester Resin Dispersion B2]
The obtained amorphous polyester resin B2 was dispersed using a disperser in which Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) was modified to a high temperature and high pressure type. Charged at a composition ratio of 70% by weight of ion-exchanged water and 30% by weight of amorphous polyester resin B2,
As a surfactant having a sulfone group with respect to 100 g of amorphous polyester resin B2 solid content, 2.0 wt% (0.0058 mol) of linear alkylbenzene sulfonate sodium (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK) is added. At the same time, 2.6 wt% (0.0008 mol) of sodium stearate having a carboxyl group (manufactured by Wako Pure Chemical Industries, Ltd.) having a carboxyl group was added to 100 g of the amorphous polyester resin B2 solid content.

  Furthermore, by adjusting the pH to 9.0 with dilute ammonia water, operating the Cavitron under conditions of a rotor speed of 60 Hz, a pressure of 0.5 MPa, and heating by a heat exchanger at 140 ° C. A polyester resin dispersion B2 was obtained.

  The volume average particle diameter of the amorphous polyester resin particles in the obtained amorphous polyester resin dispersion B2 was 160 μm.

[Preparation of Amorphous Polyester Resin Dispersion B3]
The obtained amorphous polyester resin B3 was dispersed using a disperser in which Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) was modified to a high temperature and high pressure type. As a surfactant having a sulfone group with respect to 100 g of the solid content of amorphous polyester resin B3, charged with a composition ratio of 70% by weight of ion-exchanged water and a concentration of 30% by weight of amorphous polyester resin B3, linear alkylbenzenesulfonic acid Sodium (1st Kogyo Seiyaku Co., Ltd., Neogen RK) is added in an amount of 1.0% by weight (0.000029 mol), and surfactant sodium stearate having a carboxyl group with respect to 100 g of amorphous polyester resin B3 solid content ( 3.6% by weight (0.0122 mol) was added.

  Furthermore, by adjusting the pH to 8.7 with dilute ammonia water, operating the Cavitron under the conditions of a rotor rotation speed of 60 Hz, a pressure of 0.5 MPa, and heating by a heat exchanger at 140 ° C., an amorphous property A polyester resin dispersion B3 was obtained.

  The volume average particle diameter of the amorphous polyester resin particles in the obtained amorphous polyester resin dispersion B3 was 180 μm.

[Preparation of Amorphous Polyester Resin Dispersion B4]
The obtained amorphous polyester resin B2 was dispersed using a disperser in which Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) was modified to a high temperature and high pressure type. Charged at a composition ratio of 70% by weight of ion-exchanged water and 30% by weight of amorphous polyester resin B2,
As a surfactant having a sulfone group with respect to 100 g of solid content of amorphous polyester resin B2, 1.0% by weight (0.0023 mol) of sodium dodecyl diphenyl ether sulfonate (Belex SS-H manufactured by Kao Corporation) was added, 4.4 wt% (0.015 mol) of sodium stearate (manufactured by Wako Pure Chemical Industries, Ltd.) having a carboxyl group was added to 100 g of amorphous polyester resin B2 solid content.

  Furthermore, by adjusting the pH to 8.8 with dilute ammonia water, operating the Cavitron under the conditions of a rotor rotation speed of 60 Hz, a pressure of 0.5 MPa, and heating by a heat exchanger at 140 ° C., an amorphous property A polyester resin dispersion B4 was obtained. The volume average particle diameter of the amorphous polyester resin particles in the obtained amorphous polyester resin dispersion B4 was 162 μm.

[Preparation of Amorphous Polyester Resin Dispersion B5]
The obtained amorphous polyester resin B1 was dispersed using a disperser in which Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) was modified to a high temperature and high pressure type. Charged at a composition ratio of 70% by weight of ion-exchanged water and 30% by weight of amorphous polyester resin B1,
As a surfactant having a sulfone group with respect to 100 g of solid content of amorphous polyester resin B1, 0.5% by weight (0.0013 mol) of linear dodecylbenzenesulfonate sodium (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK) At the same time, 5.88% by weight (0.02 mol) of sodium stearate having a carboxyl group (manufactured by Wako Pure Chemical Industries, Ltd.) having a carboxyl group was added to 100 g of solid content of amorphous polyester resin B1.

  Furthermore, by adjusting the pH to 8.8 with dilute ammonia water, operating the Cavitron under the conditions of a rotor rotation speed of 60 Hz, a pressure of 0.5 MPa, and heating by a heat exchanger at 140 ° C., an amorphous property A polyester resin dispersion B5 was obtained. The volume average particle diameter of the amorphous polyester resin particles in the obtained amorphous polyester resin dispersion B5 was 210 μm.

[Preparation of Amorphous Polyester Resin Dispersion B6]
The obtained amorphous polyester resin B3 was dispersed using a disperser in which Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) was modified to a high temperature and high pressure type. Linear dodecylbenzenesulfone as a surfactant charged with a composition ratio of 70% by weight of ion-exchanged water and a concentration of 30% by weight of amorphous polyester resin B3 and having a sulfone group with respect to 100 g of solid content of amorphous polyester resin B3. Sodium surfactant (sodium stearate having a carboxyl group based on 100 g of solid content of amorphous polyester resin B3) while adding 3.0 wt% (0.0084 mol) of sodium acid (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK) 2% by weight (0.0065 mol) (manufactured by Wako Pure Chemical Industries, Ltd.) was added.

  Furthermore, by adjusting the pH to 8.6 with dilute ammonia water, operating the Cavitron under the conditions of a rotor rotation speed of 60 Hz, a pressure of 0.5 MPa, and heating by a heat exchanger at 140 ° C. A polyester resin dispersion B6 was obtained. The volume average particle diameter of the amorphous polyester resin particles in the obtained amorphous polyester resin dispersion B3 was 180 μm.

[Preparation of Amorphous Polyester Resin Dispersion B7]
The obtained amorphous polyester resin B1 was dispersed using a disperser in which Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) was modified to a high temperature and high pressure type. A composition ratio of 70% by weight of ion-exchanged water and a concentration of 30% by weight of amorphous polyester resin B1 was charged.

  Furthermore, by adjusting the pH to 8.5 with dilute ammonia water, operating the Cavitron under the conditions of a rotor rotation speed of 60 Hz, a pressure of 0.5 MPa, and heating by a heat exchanger at 140 ° C., an amorphous property A polyester resin dispersion B7 was obtained. The volume average particle diameter of the amorphous polyester resin particles in the obtained amorphous polyester resin dispersion B7 was 210 μm.

[Preparation of Amorphous Polyester Resin Dispersion B8]
The obtained amorphous polyester resin B1 was dispersed using a disperser in which Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) was modified to a high temperature and high pressure type. Linear dodecylbenzenesulfone as a surfactant charged with a composition ratio of 70% by weight of ion-exchanged water and a concentration of 30% by weight of amorphous polyester resin B1 and having a sulfone group with respect to 100 g of solid content of amorphous polyester resin B1. Sodium stearate having a carboxyl group with respect to 100 g of solid content of amorphous polyester resin B1 while adding 6.0 wt% (0.0167 mol) of sodium acid (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK) 2% by weight (0.0065 mol) (manufactured by Wako Pure Chemical Industries, Ltd.) was added.

  Furthermore, by adjusting the pH to 8.4 with dilute ammonia water, operating the Cavitron under the conditions of a rotor rotation speed of 60 Hz, a pressure of 0.5 MPa, and heating by a heat exchanger at 140 ° C. A polyester resin dispersion B8 was obtained. The volume average particle diameter of the amorphous polyester resin particles in the obtained amorphous polyester resin dispersion B8 was 210 μm.

[Preparation of Amorphous Polyester Resin Dispersion B9]
The obtained amorphous polyester resin B4 was dispersed using a disperser in which Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) was modified to a high temperature and high pressure type. Linear dodecylbenzenesulfone as a surfactant charged with a composition ratio of 70% by weight of ion-exchanged water and a concentration of 30% by weight of amorphous polyester resin B4 and having a sulfone group with respect to 100 g of amorphous polyester resin B4 solid content. Sodium stearate having a carboxyl group with respect to 100 g of amorphous polyester resin B4 solid content while adding 2.0 wt% (0.000056 mol) of sodium acid (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK) (Wako Pure Chemical Industries, Ltd.) was added in an amount of 0.5% by weight (0.0019 mol).

  Furthermore, by adjusting the pH to 9.0 with dilute ammonia water, operating the Cavitron under conditions of a rotor speed of 60 Hz, a pressure of 0.5 MPa, and heating by a heat exchanger at 140 ° C. A polyester resin dispersion B9 was obtained. The volume average particle diameter of the amorphous polyester resin particles in the obtained amorphous polyester resin dispersion B8 was 230 μm.

[Preparation of Amorphous Polyester Resin Dispersion B10]
The obtained amorphous polyester resin B3 was dispersed using a disperser in which Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) was modified to a high temperature and high pressure type. Linear dodecylbenzenesulfone as a surfactant charged with a composition ratio of 70% by weight of ion-exchanged water and a concentration of 30% by weight of amorphous polyester resin B3 and having a sulfone group with respect to 100 g of solid content of amorphous polyester resin B3. Sodium stearate having a carboxyl group with respect to 100 g of solid content of amorphous polyester resin B3 while adding 3.5 wt% (0.00088 mol) of sodium acid (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK) 2.8% by weight (0.00094 mol) (manufactured by Wako Pure Chemical Industries, Ltd.) was added.

  Furthermore, by adjusting the pH to 8.6 with dilute ammonia water, operating the Cavitron under the conditions of a rotor rotation speed of 60 Hz, a pressure of 0.5 MPa, and heating by a heat exchanger at 140 ° C. A polyester resin dispersion B10 was obtained. The volume average particle diameter of the amorphous polyester resin particles in the obtained amorphous polyester resin dispersion B10 was 175 μm.

[Preparation of Amorphous Polyester Resin Dispersion B11]
The obtained amorphous polyester resin B5 was dispersed using a disperser in which Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) was modified to a high temperature and high pressure type. Linear dodecylbenzenesulfone as a surfactant charged with a composition ratio of 70% by weight of ion-exchanged water and a concentration of 30% by weight of amorphous polyester resin B5 and having a sulfone group with respect to 100 g of solid content of amorphous polyester resin B5. Sodium stearate having a carboxyl group with respect to 100 g of solid content of amorphous polyester resin B5 while adding 1.0 wt% (0.000028 mol) of sodium acid (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK) 1.0% by weight (0.0033 mol) (manufactured by Wako Pure Chemical Industries, Ltd.) was added.

  Furthermore, by adjusting the pH to 9.1 with dilute ammonia water, operating the Cavitron under the conditions of a rotor rotation speed of 60 Hz, a pressure of 0.5 MPa, and heating by a heat exchanger at 140 ° C., an amorphous property A polyester resin dispersion B10 was obtained. The volume average particle diameter of the amorphous polyester resin particles in the obtained amorphous polyester resin dispersion B8 was 162 μm.

[Preparation of Amorphous Polyester Resin Dispersion B12]
The obtained amorphous polyester resin B6 was dispersed using a disperser in which Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) was modified to a high temperature and high pressure type. Linear dodecylbenzenesulfone as a surfactant charged with a composition ratio of 70% by weight of ion-exchanged water and a concentration of 30% by weight of amorphous polyester resin B6 and having a sulfone group with respect to 100 g of solid content of amorphous polyester resin B6. Sodium stearate having a carboxyl group with respect to 100 g of solid content of amorphous polyester resin B6 while adding 3.5 wt% (0.00088 mol) of sodium acid (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK) 3.0% by weight (0.0102 mol) (manufactured by Wako Pure Chemical Industries, Ltd.) was added.

  Furthermore, by adjusting the pH to 8.7 with dilute ammonia water, operating the Cavitron under the conditions of a rotor rotation speed of 60 Hz, a pressure of 0.5 MPa, and heating by a heat exchanger at 140 ° C., an amorphous property A polyester resin dispersion B8 was obtained. The volume average particle diameter of the amorphous polyester resin particles in the obtained amorphous polyester resin dispersion B12 was 173 μm.

[Preparation of Amorphous Polyester Resin Dispersion B13]
The obtained amorphous polyester resin B1 was dispersed using a disperser in which Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) was modified to a high temperature and high pressure type. Linear dodecylbenzenesulfone as a surfactant charged with a composition ratio of 70% by weight of ion-exchanged water and a concentration of 30% by weight of amorphous polyester resin B1 and having a sulfone group with respect to 100 g of solid content of amorphous polyester resin B1. Sodium sulfate (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK) was added at 6.0 wt% (0.0167 mol).

  Furthermore, by adjusting the pH to 8.4 with dilute ammonia water, operating the Cavitron under the conditions of a rotor rotation speed of 60 Hz, a pressure of 0.5 MPa, and heating by a heat exchanger at 140 ° C. A polyester resin dispersion B8 was obtained. The volume average particle diameter of the amorphous polyester resin particles in the obtained amorphous polyester resin dispersion B8 was 210 μm.

[Preparation of Amorphous Polyester Resin Dispersion B14]
The obtained amorphous polyester resin B1 was dispersed using a disperser in which Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) was modified to a high temperature and high pressure type. A surfactant sodium stearate (Wako Pure Chemical Industries, Ltd.) having a carboxyl group with respect to 100 g of amorphous polyester resin B1 solid content was charged at a composition ratio of 70% by weight of ion-exchanged water and 30% by weight of amorphous polyester resin B1. 4% by weight (0.0136 mol) was added.

  Furthermore, by adjusting the pH to 8.4 with dilute ammonia water, operating the Cavitron under the conditions of a rotor rotation speed of 60 Hz, a pressure of 0.5 MPa, and heating by a heat exchanger at 140 ° C. A polyester resin dispersion B8 was obtained. The volume average particle diameter of the amorphous polyester resin particles in the obtained amorphous polyester resin dispersion B8 was 400 μm.

Materials constituting the above-mentioned amorphous polyester resin dispersions B1 to B14, and resin particle average particle size (volume average particle size), pH, weight ratio A + weight ratio B, and (1.62 × binder resin solid content 100 g) Table 3 and Table 4 show values of the amount a) of the surfactant having a sulfone group relative to the amount of the surfactant a having a carboxyl group relative to 100 g of the binder resin solid content b).
In Tables 3 and 4, “polyester resin dispersion” means an amorphous polyester resin dispersion, and “polyester resin” means an amorphous polyester resin. In Tables 3 and 4, “W” means the above linear sodium alkylbenzene sulfonate (Neogen RK Daiichi Kogyo Seiyaku Co., Ltd.), and “Z” means the above sodium alkyldiphenyl ether disulfonate (Perex SS- H made by Kao). Further, a and b are the same as described above, the amount a (mol) of the surfactant having a sulfone group with respect to 100 g of the binder resin solid content, and the surfactant having a carboxyl group with respect to 100 g of the binder resin solid content. The quantity b (mol) is shown.

(Preparation of colorant particle dispersion)
Cyan pigment 20 parts by weight (manufactured by Dainichi Seika Co., Ltd .: ECB-301), 2 parts by weight of anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC, 10% by weight based on colorant as an active ingredient), ion Using 78 parts by weight of replacement water, when all of the above components are charged, the liquid level is charged into a stainless steel container whose size is about 1/3 of the container height, and a homogenizer (manufactured by IKA, Ultra Using a Thalax T50), the mixture was dispersed at 6000 rpm for 5 minutes, and then stirred for one day with a stirrer to degas.
Subsequently, the obtained dispersion was dispersed at a pressure of 240 MPa using a high-pressure impact disperser ultimateizer (manufactured by Sugino Machine Co., Ltd., HJP30006). The dispersion was equivalent to 25 passes in terms of the total amount of squeeze and the processing capacity of the apparatus. Thereafter, ion exchange water was added to adjust the solid content concentration to 15.0% by weight.
When the average particle diameter of the obtained colorant dispersion was measured with Microtrac UPA, the volume average particle diameter D50v was 115 nm.

(Preparation of release agent dispersion)
Carnauba wax (melting point: 81 ° C) 40 parts by weight, anionic surfactant 2 parts by weight (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) and ion-exchanged water 58 parts by weight, homogenizer (IKA, Ultra Turrax T50) ) For 5 minutes at 6000 rpm, and the mixture was stirred for a whole day and night with a stirrer to degas. Subsequently, the mixture was dispersed with a pressure discharge type gorin homogenizer, and then ion-exchanged water was added to adjust the solid content concentration to 25.0 wt%. When the particle size distribution of the obtained release agent dispersion was measured with Microtrac UPA, the volume average particle size D50v was 220 nm.

<Example B1>
-Production of toner particles (B1)-
-Ion exchange water: 410 parts by weight-Amorphous polyester resin dispersion B1: 200 parts by weight
The above components were put into a 3 liter reaction vessel equipped with a thermometer, a pH meter, and a stirrer, and maintained at a temperature of 30 ° C. and a stirring rotational speed of 150 rpm for 30 minutes while controlling the temperature with a mantle heater from the outside.

afterwards,
-Colorant dispersion: 50 parts by weight (colorant concentration 15% by weight)
Release agent dispersion: 60 parts by weight (release agent concentration 25% by weight)
The above ingredients were added and held for 5 minutes.
The 1.0 wt% nitric acid aqueous solution was added as it was to adjust the pH to 3.0.

  Subsequently, the stirrer and the mantle heater were removed, and after adding 0.25 parts by weight of polyaluminum chloride while being dispersed at 3000 rpm with a homogenizer (manufactured by IKA Japan: Ultra Tarax T50), the mixture was stirred at 50 ° C. While increasing the temperature, the particle size was measured every 10 minutes with a Coulter counter [TA-II] type (aperture diameter: 50 μm, manufactured by Coulter).

  When the volume average particle diameter D50v of the aggregated particles reached 5.0 μm, 20 parts by weight of amorphous polyester resin dispersion (B1) was added. After holding for 30 minutes, the pH was adjusted to 9.0 using a 5 wt% aqueous sodium hydroxide solution.

  Thereafter, while adjusting the pH to 9.0 every 5 ° C., the temperature was raised to 90 ° C. at a temperature rising rate of 1 ° C./min and held at 90 ° C. When the particle shape and surface properties were observed every 30 minutes with an optical microscope and a scanning electron microscope (FE-SEM), the particles were almost spherical in 3 hours. Solidified to obtain a toner slurry containing toner particles.

  Thereafter, the toner particles obtained by filtering the toner slurry are washed with ion-exchanged water, repeatedly washed until the filtrate has a conductivity of 20 μS / cm or less, and then in an oven at 40 ° C. The toner was obtained by vacuum drying for 5 hours.

To 100 parts by weight of the obtained toner, 1.5 parts by weight of hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd., RY50) and 1.0 part by weight of hydrophobic titanium oxide (manufactured by Nippon Aerosil Co., Ltd., T805) And blended for 30 seconds at 10,000 rpm using a sample mill.
Thereafter, the toner (B1) was prepared by sieving with a vibration sieve having an opening of 45 μm.

<Example B2>
A toner (B2) was obtained by the same operation except that the amorphous polyester resin dispersion B1 used in Example B1 was changed to an amorphous polyester resin dispersion B2.

<Example B3>
A toner (B3) was obtained by the same operation except that the amorphous polyester resin dispersion B1 used in Example B1 was changed to an amorphous polyester resin dispersion B5.

<Example B4>
A toner (B4) was obtained by the same operation except that the amorphous polyester resin dispersion B1 used in Example B1 was changed to an amorphous polyester resin dispersion B4.

<Example B5>
A toner (B5) was obtained by the same operation except that the amorphous polyester resin dispersion B1 used in Example B1 was changed to an amorphous polyester resin dispersion B5.

<Example B6>
A toner (B6) was obtained by the same operation except that the amorphous polyester resin dispersion B1 used in Example B1 was changed to an amorphous polyester resin dispersion B6.

<Comparative Example B1>
A toner (B7) was obtained by the same operation except that the amorphous polyester resin dispersion B1 used in Example B1 was changed to an amorphous polyester resin dispersion B7.

<Comparative Example B2>
A toner (B8) was obtained by the same operation except that the amorphous polyester resin dispersion B1 used in Example B1 was changed to an amorphous polyester resin dispersion B8.

<Comparative Example B3>
A toner (B9) was obtained by the same operation except that the amorphous polyester resin dispersion B1 used in Example B1 was changed to an amorphous polyester resin dispersion B9.

<Comparative Example B4>
A toner (B10) was obtained by the same operation except that the amorphous polyester resin dispersion B1 used in Example B1 was changed to an amorphous polyester resin dispersion B10.

<Comparative Example B5>
A toner (B11) was obtained by the same operation except that the amorphous polyester resin dispersion B1 used in Example B1 was changed to an amorphous polyester resin dispersion B11.

<Comparative Example B6>
A toner (B12) was obtained by the same operation except that the amorphous polyester resin dispersion B1 used in Example B1 was changed to an amorphous polyester resin dispersion B12.

<Comparative Example B7>
A toner (B13) was obtained by the same operation except that the amorphous polyester resin dispersion B1 used in Example B1 was changed to an amorphous polyester resin dispersion B13.

<Comparative Example B8>
A toner (B14) was obtained by the same operation except that the amorphous polyester resin dispersion B1 used in Example B1 was changed to an amorphous polyester resin dispersion B14.

  Tables 5 and 6 show the average particle sizes and particle size distributions of the toner (B1) to the toner (B14) obtained as described above.

(Carrier production)
Ferrite particles (volume average particle size 50 μm): 100 parts by weight Toluene: 14 parts by weight Styrene / methyl methacrylate copolymer (copolymerization ratio (molar ratio): 15/85): 2 parts by weight Carbon black (VXC72 : Cabot)): 0.2 parts by weight
First, among the above components, the components excluding the ferrite particles are stirred for 10 minutes with a sand mill, the dispersed coating solution is weighed, and then the coating solution and the ferrite particles are put into a vacuum degassing kneader and stirred. However, after reducing the pressure to −20 mmHg at 60 ° C. and mixing for 30 minutes, the temperature was increased / decreased and the mixture was stirred and dried at 90 ° C./−720 mmHg for 30 minutes to obtain a carrier. This carrier had a volume resistivity of 5 × 10 ¹³ Ωcm when an applied electric field of 10000 V / cm.

(Developer adjustment)
After blending 20 parts by weight of each toner (toner (B1) to toner (B14)) obtained in Examples and Comparative Examples with a V-type blender for 20 minutes with respect to 100 parts by weight of the carrier, an opening having a mesh size of 212 microns. Coarse particles were removed by a vibration sieve to obtain developers (B1) to (B14).

[Toner hygroscopicity]
Each of the produced toner (B1) to toner (B14) was vacuum dried in an oven at 60 ° C. for 10 hours. For each of the toner (B1) to toner (B14) in a vacuum-dried state, moisture was measured using an infrared moisture meter. Further, each of the toner (B1) to toner (B14) vacuum-dried in the 60 ° C. oven for 10 hours is left in an environmental chamber at a room temperature of 32 ° C. and a humidity of 75% RH for 24 hours, and then the toner (B1) to Each of the toners (B14) was measured for the moisture content of the toner using the infrared moisture meter, and the difference in toner moisture content before and after being left in the environmental chamber, that is, {(left at room temperature 32 ° C. and humidity 75% RH). (Moisture ratio after)-(Moisture ratio before leaving)} / 100 was defined as the toner moisture absorption rate.

[Colorant dispersion evaluation]
The cross section of the toner particles was observed with a transmission electron microscope and evaluated. The evaluation criteria are as follows.
○: Colorant particles are uniformly dispersed with respect to toner particles.
X: Aggregation of a large colorant is observed in the toner particles, and is practically unusable.

[Amount of anionic surfactant in the prepared toner]
The amount of the anionic surfactant remaining (containing) in each of the produced toner (B1) particles to toner (B14) particles was determined by the following method.
First, 1 g of toner particles was put into 6 g of acetone, the binder resin component of the toner particles was dissolved, and the anionic surfactant on the toner surface and inside was extracted into acetone. Next, ion exchange water is added to 550 g of this acetone solution to precipitate the binder resin again, and insoluble matters such as binder resin components, colorant particles, and release agent particles are removed by filtration to remove acetone / ion exchange. After removing acetone from the water filtrate with an evaporator, ethanol was added to prepare a 95% ethanol solution.

  Thereafter, this ethanol solution is sequentially trapped with a cation exchanger and an anion exchanger, each ion exchanger is washed away with a 2N HCl solution, and then the anion exchanger is trapped, and then the 2N HCl solution. After rinsing, the color was determined by the bromocresol green quinine method and quantified by absorbance at 610 nm. The amount of the anionic surfactant obtained by the above method was defined as the amount of the surfactant remaining in the toner.

[Image evaluation method]
Each developer obtained in an environmental chamber at room temperature of 32 ° C. and humidity of 75% is set in a developer of a DocuCenter Color 400 modified machine manufactured by Fuji Xerox Co., Ltd. The background fog of the obtained image and the sharpness of the character image were evaluated. As paper, C2 paper manufactured by Fuji Xerox Office Supply Co., Ltd. was used, and images containing Japanese characters including 4-point and 6-point kanji were formed.

― Fogging ―
After continuous printout of 50000 sheets, the fog was evaluated visually, and the following G1 to G5 were evaluated by comparison with a limit sample. Usually, if it is G2 or less, it can be determined that there is no problem in image quality.
G1: No fogging is seen.
G2: Although fog is observed with a loupe, there is no problem in actual use.
G3: Can be confirmed visually.
G4: It is easily observed visually.
G5: The fog is observed wisely.

-Sharpness-
After continuous printing of 50000 sheets, the sharpness of the character image was evaluated from the visual readability of Japanese characters with different sizes. The evaluation criteria are as follows.
○: 4-point Japanese characters can be read
Δ: 6-point Japanese characters can be read
×: 6-point Japanese characters difficult to read or unreadable

-Image density-
After continuous printing of 50000 sheets, the image density of the character image was measured with an X-rite 404 densitometer. In addition, if the image density is 1.20, it is a level with no problem.

-Evaluation of toner chargeability-
Remove the developer after printing out 50000 sheets continuously, adjust the amount of toner to 4% of the total amount of developer, and blow off the charge amount when stirred in an environmental chamber at room temperature of 32 ° C and humidity of 75% for 1 minute. This was confirmed by the method (TB-200, manufactured by Toshiba Chemical Corporation). Note that air was used as the gas at this time.

-Evaluation criteria for toner chargeability-
A: When the charge amount is 30 μC / g or more in absolute value.
◯: When the charge amount is 15 μC / g or more and less than 30 μC / g in absolute value.
Δ: When the charge amount is less than 15 μC / g in absolute value.

-Stability evaluation of polyester resin dispersion-
The produced amorphous polyester resin dispersions B1 to B14 were allowed to stand at 50 ° C. for 7 days, and the dispersions were evaluated according to the following criteria.
-Evaluation criteria for polyester resin dispersion-
A: When there is no precipitate at the bottom of the dispersion.
○: When there is a slight precipitate at the bottom of the dispersion.
(Triangle | delta): When there exists a deposit clearly at the bottom of a dispersion liquid.
The evaluation results are shown in Table 4 above.

From Table 5 and FIG. 6, the following matters are clear. In other words, Examples B1 to B6 show results that the image density, the sharpness, the fog, and the chargeability are good.
On the other hand, Comparative Examples B1 to B8 resulted in problems in any of image density, sharpness, fog, chargeability, and storage stability of the dispersion depending on the amount and type of anionic surfactant.

Relative value of surfactant having a sulfone group as a surfactant for a surfactant having a carboxyl group 1 is a schematic diagram illustrating a configuration of an image forming apparatus according to an embodiment of the present invention.

Explanation of symbols

80 Electrophotographic Photoreceptor 82 Image Forming Device 84 Charging Device 86 Exposure Device 87 Cleaning Member 88 Development Device 89 Transfer Device 90 Fixing Device

Claims (5)

An electrostatic charge developing toner containing at least a binder resin and a release agent,
A surfactant containing a metal element capable of taking a valence of 2 or more, a surfactant having a sulfone group, and a surfactant having a carboxyl group, and having the sulfone group with respect to 100 g of the binder resin solid content. The relationship between the amount a (mol) of the agent and the amount b (mol) of the surfactant having a carboxyl group with respect to 100 g of the binder resin solid content is the condition of the following formula (1) and the following formula (2). An electrostatic charge developing toner characterized by satisfying:
0.0015 ≦ a ≦ 0.006 Equation (1)
0.018 ≦ 1.62 × a + b ≦ 0.025 (2) Aggregated particles containing at least the resin particles and the colorant in a mixed dispersion obtained by mixing a resin particle dispersion in which resin particles containing at least a binder resin are dispersed and a colorant dispersion in which a colorant is dispersed. An agglomeration step to form,
A fusion step of fusing the aggregated particles by heating;
A method for producing an electrostatic charge developing toner comprising:
The mixed dispersion contains a metal element capable of having a valence of 2 or more, a surfactant having a sulfone group, and a surfactant having a carboxyl group, and the sulfone with respect to 100 g of the binder resin solid content. The relationship between the amount a (mol) of the surfactant having a group and the amount b (mol) of the surfactant having a carboxyl group with respect to 100 g of the binder resin solid content is expressed by the following formula (3) and the following formula ( 4. A method for producing a toner for developing electrostatic charge, which satisfies the condition 4).
0.0015 ≦ a ≦ 0.006 Equation (3)
0.018 ≦ 1.62 × a + b ≦ 0.025 Equation (4) An electrostatic latent image developer comprising the electrostatic charge developing toner according to claim 1 . A charging step for charging the surface of the image carrier;
A developing step of developing a latent electrostatic image corresponding to image information on the charged image carrier surface with an electrostatic latent image developer containing at least an electrostatic charge developing toner to obtain a toner image;
A transfer step of transferring a toner image on the image carrier to a recording medium;
A fixing step of fixing the toner image on a recording medium;
In an image forming method including at least
The image forming method according to claim 1, wherein the electrostatic charge developing toner is the electrostatic latent image developing toner according to claim 1 . Charging means for charging the surface of the image carrier;
Developing means for developing a toner image by developing an electrostatic latent image corresponding to image information on the surface of the image carrier charged by the charging means with an electrostatic latent image developer containing at least an electrostatic charge developing toner;
Transfer means for transferring a toner image on the image carrier to a recording medium;
Fixing means for fixing the toner image on a recording medium;
An image forming apparatus comprising:
The image forming apparatus according to claim 1, wherein the electrostatic charge developing toner is the electrostatic latent image developing toner according to claim 1 .

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