JP4844746B2 - Toner manufacturing method - Google Patents

Description

  The present invention relates to a method for producing a toner for developing an electrostatic charge image that is suitably used in a copying machine, a printer, a fax machine, and the like, and further used in a toner jet type printer.

  In image output devices such as electrophotographic copiers, printers, fax machines, etc., the resolution of printed images is improved, the gradation is improved, the amount of waste toner is reduced, and the energy consumption is reduced by lowering the fixing temperature. In view of demands for improving image characteristics in full-color images, toner particles used for image formation use a polymerization method, an emulsification dispersion method, or the like instead of a pulverization method in which small particle size particles are produced by pulverization.

In the toner manufacturing method by the polymerization method, since the binder resin is limited to a vinyl polymer capable of radical polymerization, the toner cannot be manufactured using a polyester resin as a raw material. In addition, the polymerization method has a problem that volatile organic compounds composed of unreacted monomers remain.
Therefore, a method has been proposed in which a polyester resin or the like is emulsified and dispersed as a binder resin, and then the obtained fine particles are aggregated and further heated and fused to form an aggregate. Therefore, there is a problem that it is necessary to stir at high temperature for a long time.

  In addition, a method has been proposed in which fine particles are produced by emulsification and dispersion, and then the step of aggregating the fine particles and the step of fusing the agglomerated fine particles are performed at the same time. They are united by collisions between particles under force. For this reason, the coalescence tends to be non-uniform, and the generation of aggregates is inevitable. On the other hand, since emulsification and dispersion are performed under shearing force, and then the particles are aggregated under the same conditions, crushing occurs at the same time as coalescence, so the generation of fine particles increases, and the particle size distribution of the toner particles to be generated is increased. There was a limit to narrowing.

  In contrast to these methods, a toner manufacturing method is proposed in which a binder resin such as a polyester resin, wax, colorant, etc. is dissolved or dispersed in an organic solution, and the resulting oil phase component is dispersed and granulated in an aqueous medium. Has been. In this method, in order to reduce emulsification loss and obtain a sharp particle size distribution, an oil phase component is emulsified in an aqueous medium to form fine particles of the mixture in the aqueous medium, followed by dispersion stabilization. A toner is manufactured through a coalescing step in which the fine particles are coalesced by adding an agent and sequentially adding an electrolyte (see, for example, Patent Documents 1 and 2). In this production method, it has been studied to use wax fine particles in which the wax is finely dispersed to the particle size of the toner particles or less by wet dispersion using a medium forcibly, but the shape of the wax fine particles is changed from a potato shape to a needle shape or Due to the spindle shape, the particle size distribution of the wax fine particles is wide, and the wax is exposed from the surface of the obtained toner particles, resulting in a problem that the development durability of the toner is lowered.

On the other hand, the presence of a neutralizing agent in an amount sufficient to make the resin self-water-dispersible with a mixture that can be self-water-dispersible by neutralization, a colorant, a wax emulsion, and an organic solvent. A self-water-dispersible resin particle in which a colorant and wax fine particles are encapsulated in an aqueous medium by phase-inverting and emulsifying in addition to the aqueous medium or by adding an aqueous medium to the mixture and inversion-emulsifying below. After producing the toner, a method for producing a capsule toner in which the particles are separated and dried is studied (for example, see Patent Document 3). In this manufacturing method, by using a wax emulsion having a narrow particle size distribution and a substantially spherical shape, the exposure of the wax to the toner particle surface is reduced, but the water-based wax emulsion is combined with a binder resin, an organic solvent and a colorant. Since the wax emulsion aggregates when kneaded, the amount of added wax is limited.
JP 2003-122051 A JP 2004-198598 A Japanese Patent Laid-Open No. 10-186714

  The present invention relates to a method for producing a toner for developing an electrostatic charge image in which a water-based wax emulsion, a binder resin, a colorant and an organic solvent are used as raw materials. It is a problem to solve the problem.

The present invention relates to a wax master solution prepared from a binder resin, an organic solvent and a wax emulsion, a step of obtaining a colored resin solution by dissolving or dispersing the binder resin and a colorant in an organic solvent, A step of emulsifying the colored resin solution in an aqueous medium by sequentially adding a functional compound and water, adding an aqueous electrolyte solution to the prepared emulsion suspension, and combining the dispersoids in the emulsion suspension A step of forming colored resin fine particles to form particles, and after removing the organic solvent under reduced pressure, a step of separating, washing and drying the colored resin fine particles from the aqueous medium is performed. This is a method for producing a toner for developing an electrostatic image of 8 μm.
In a preferred embodiment of the present invention, in the above method for producing an electrostatic charge image developing toner having a volume average particle diameter of 5 to 8 μm, methyl ethyl ketone is contained in the wax master solution medium in the range of 22% by mass to 51% by mass, The wax is contained in the wax master solution in the range of 9% by mass to 15% by mass.

The present invention stirs a binder resin, an organic solvent, and a wax emulsion under conditions of a product temperature of 35 ° C. or lower, a specific energy amount of 0.5 to 3.0 kWh / kg, and a residence time of 15 minutes or more, and a wax master solution medium. A step of preparing a wax master solution in which methyl ethyl ketone is contained in the range of 22% to 51% by weight and wax is contained in the wax master solution in the range of 9% to 15% by weight, the wax master solution, and the binder resin And a step of dissolving or dispersing the colorant in an organic solvent to obtain a colored resin solution, a step of sequentially adding a basic compound and water to the colored resin solution to emulsify the colored resin solution in an aqueous medium, and a prepared emulsification Adding electrolyte aqueous solution to the suspension and combining the dispersoid in the emulsified suspension to produce colored resin fine particles to form particles; In the method for producing a toner for developing an electrostatic charge image having a volume average particle size of 1.5 to 4 μm, the organic resin is removed under the following steps, followed by a step of separating, washing and drying the colored resin fine particles from the aqueous medium. is there.
In a preferred embodiment of the present invention, in the above method for producing a toner for developing an electrostatic charge image having a volume average particle size of 1.5 to 4 μm, a wax emulsion is added to a resin solution obtained by dissolving a binder resin in an organic solvent. Disperse to prepare a wax master solution.
In another preferred embodiment of the present invention, a wax emulsion is finely dispersed in a resin solution by a bead mill in the above method for producing a toner for developing an electrostatic image.
In another preferred embodiment of the present invention, in the above method for producing an electrostatic image developing toner, the binder resin is a polyester resin.

The present invention will be described in detail below. The production method of the present invention comprises the following steps.
First step: Colored resin solution preparation step In this step, a wax master solution prepared from a binder resin, an organic solvent and a wax emulsion, and a binder resin and a colorant are dissolved or dispersed in an organic solvent to obtain a colored resin solution. is there.
Second step: emulsification step In this step, a basic compound and water are sequentially added to the colored resin solution to emulsify the colored resin solution in the aqueous medium.
Third step: coalescence step At least one step of adding colored electrolyte aqueous solution to the prepared emulsion suspension and coalescing the dispersoid in the emulsion suspension to produce colored resin fine particles to form particles This is a step of stopping the coalescence when the target particle size is reached after being performed once.
Fourth Step: Separation / Drying Step In this step, after removing the organic solvent under reduced pressure, the colored resin fine particles are separated from the aqueous medium, washed and dried to obtain toner base particles.

First, the first step will be described. In the first step, a colored resin composition is prepared by charging and dissolving or dispersing a binder resin and a colorant in an organic solvent, and then a wax master prepared from the binder resin, the organic solvent, and a wax emulsion. The solution is put into a colored resin composition to obtain a colored resin solution.
The binder resin and the colorant are preferably dissolved or dispersed in an organic solvent with a high-speed stirrer. In this case, the colorant may be pre-dispersed in advance to prepare a master kneading chip, and finely dispersed below the toner particle diameter to be prepared.

  The wax emulsion is obtained by emulsifying wax in the presence of an emulsifier. The emulsifier is not particularly limited. For example, polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan Nonionic emulsifiers such as fatty acid esters, various pluronics, alkyl sulfate ester type, alkyl sulfonate type anionic emulsifiers, quaternary ammonium salt type cationic emulsifiers, alkyl benzene sulfonate type emulsifiers, direct Mention may be made of chain alkylbenzene sulfonic acid type emulsifiers. The average particle size of the wax emulsion is preferably 0.05 μm to 3 μm, more preferably 0.1 to 1.5 μm, and particularly preferably 0.2 to 1.2 μm. The average particle diameter of the wax emulsion can be measured using Microtrack MT-3000II manufactured by Nikkiso Co., Ltd. Next, after the binder resin is dissolved in an organic solvent with a high-speed stirrer, a wax emulsion is added and further dispersed with a high-speed stirrer to prepare a wax master pre-dispersed solution. Thereafter, the wax master solution is prepared by finely dispersing with a media disperser. The media disperser used here is not particularly limited. For example, a bead mill such as LMZ10 manufactured by Ashizawa Finetech Co., Ltd., SC Mill, Mitsui Mining Co., Ltd., Eiger Motor Mill M-1000 manufactured by Eiger Corporation may be used. it can.

  As the wax, a release agent selected from hydrocarbon waxes such as polypropylene wax, polyethylene wax, and Fischer-Trofisch wax, natural ester waxes such as synthetic ester wax, carnauba wax, and rice wax is used. Can be mentioned. Of these, natural ester waxes such as carnauba wax and rice wax, synthetic ester waxes obtained from a high alcohol and a long-chain monocarboxylic acid, and hydrocarbon waxes such as Fischer-Trofisch wax are suitable. Examples of the synthetic ester wax include WEP-5 and WEP-7 (manufactured by NOF Corporation). The wax content is preferably in the range of 1 to 40% by mass with respect to the total toner. When the wax content is less than 1% by mass with respect to the whole toner, the releasability becomes insufficient, and when it exceeds 40% by mass, the wax is easily exposed on the toner particle surface, and the chargeability and storage stability are lowered. It becomes easy to do.

  When an electrostatic charge image developing toner having a volume average particle size of 1.5 to 4 μm is produced, the binder resin, organic solvent and wax emulsion have a product temperature of 35 ° C. or less and a specific energy amount of 0.5 to 3.0 kWh / Stir in kg for at least 15 minutes. Further, the concentration of methyl ethyl ketone contained in the medium of the wax master solution obtained by stirring the binder resin, the organic solvent and the wax emulsion under the above conditions is 22% by mass to 51% by mass, and the wax contained in the wax master solution The concentration of is in the range of 9% by mass to 15% by mass.

In the colored resin solution preparation step, Desper (manufactured by Asada Iron Works Co., Ltd.), T.M. K. A high-speed stirrer such as a homomixer (manufactured by PRIMIX Corporation) can be used. The blade tip speed at this time is preferably 4 to 30 m / s, and more preferably 8 to 25 m / s. By using the high-speed stirrer, the binder resin can be efficiently dissolved in the organic solvent, and uniform fine dispersion of the colorant in the binder resin solution can be achieved. That is, the state of the colorant finely dispersed in advance can be maintained in the binder resin solution by stirring at high speed.
When the blade tip speed is lower than 4 m / s, the fine dispersion of the colorant in the binder resin solution becomes insufficient, which is not preferable. On the other hand, if it is higher than 30 m / s, heat generation due to shearing becomes large, and it is not preferable because uniform stirring becomes difficult in combination with volatilization of the solvent. Moreover, the temperature in the case of melt | dissolving or disperse | distributing has the preferable range of 20-60 degreeC, and the range of 30-50 degreeC is more preferable.

  As an organic solvent, the thing whose solubility with respect to water in 25 degreeC is 0.1-30 mass% is preferable, and what is 0.1-25 mass% is more preferable. The boiling point at normal pressure is preferably lower than the boiling point of water. As such an organic solvent, for example, ketones such as methyl ethyl ketone and methyl isopropyl ketone, and esters such as ethyl acetate and isopropyl acetate are used. Two or more organic solvents can be mixed and used, but from the viewpoint of solvent recovery, it is preferable to use the same type of solvent alone. Further, the organic solvent is preferably a solvent having a low boiling point because it dissolves the binder resin and can be easily removed in a subsequent process.

An emulsifier may be added to the organic solvent together with the binder resin, the colorant, and the wax master solution.
In order for the emulsifier to function in the coalescing step, it is necessary to have a characteristic capable of maintaining dispersion stability even in the presence of an electrolyte added later. Examples of emulsifiers having such properties include polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene Nonionic emulsifiers such as oxyethylene sorbitan fatty acid esters or various pluronics, alkyl sulfate ester type, alkyl sulfonate type anionic emulsifiers, and quaternary ammonium salt type cationic emulsifiers is there. Moreover, an alkylbenzene sulfonate type emulsifier and a linear alkyl benzene sulfonic acid type emulsifier can be mentioned.
The above-mentioned emulsifiers may be used alone or in combination of two or more. That is, in the production method of the present invention, it is possible to prevent non-uniform coalescence by adding an electrolyte in the presence of an emulsifier. Thereby, a preferable particle size distribution is obtained.

  The amount of the emulsifier to be used is preferably 0.1 to 3.0% by mass, more preferably 0.3 to 2.0% by mass, and more preferably 0.3 to 1.5% by mass with respect to the solid content. It is particularly preferred that When the amount of the emulsifier to be used is less than 0.1% by mass with respect to the solid content, the desired effect of preventing the generation of coarse particles cannot be obtained. Further, when the amount of the emulsifier used is more than 3.0% by mass with respect to the solid content, the coalescence of the dispersoid in the emulsified suspension does not proceed sufficiently even if the amount of the electrolyte increases, and the predetermined amount As a result, fine particles remain and the yield decreases.

Next, in the emulsification step of the second step, a basic compound and water are sequentially added to the colored resin solution to emulsify the colored resin solution in the aqueous medium. Here, it is preferable to gradually add water to the colored resin solution in which the carboxyl group of the binder resin is neutralized by the basic compound. By neutralizing the carboxyl group, the hydrophilicity of the binder resin is improved and the affinity with water is improved.
The added water is hydrated to the carboxyl group portion of the binder resin, and the binder resin is dissolved or finely dispersed in combination with the stirring effect. On the other hand, the binder resin intervenes in the aqueous medium and the acid-base interaction becomes stronger, and the viscosity of the system containing the colored resin solution increases with the addition of water. When a certain amount of water is added, there is a point that the viscosity decreases, which is called a so-called phase inversion point. The viscosity increases until just before this, and the viscosity reaches the maximum value. The increase in viscosity correlates with the addition amount of the basic compound, and the increase in viscosity increases as the addition amount increases.

  On the other hand, the amount of the basic compound affects not only the emulsification step of the second step but also the uniformity and speed at the time of generation of colored resin fine particles in the coalescence step of the third step described later, and the carboxyl group of the binder resin A range of 1 to 3 equivalents is preferable. Moreover, the range of 1-2 equivalent is still more preferable. By adding in excess of the amount required to neutralize all the carboxyl groups of the binder resin in this way, it is possible to prevent the formation of irregularly shaped particles in the coalescing step, and toner particles The particle size distribution can be made narrow.

  The ratio of the organic solvent to the total amount of the organic solvent and water after the emulsification step is preferably in the range of 20 to 35% by mass, and more preferably in the range of 20 to 30% by mass. As described above, the amount of water up to the phase inversion point decreases as the amount of organic solvent in the colored resin solution preparation step decreases, and increases as the amount of basic compound increases. At the phase inversion point, the viscosity of the emulsion may be high, and the colored resin solution may not be completely finely dispersed in the aqueous medium. Therefore, it is preferable to further add water. The amount of water is preferably in the range of 50 to 80% by mass of the amount of water added up to the phase inversion point and the total amount of water used up to the phase inversion point.

  The binder resin used in the present invention is not particularly limited, but is preferably a polyester resin having an acid value of 3 to 30 KOHmg / g, and more preferably 5 to 20 KOHmg / g. When the acid value of the polyester resin is less than 3, toner particles cannot be produced. On the other hand, if the acid value of the polyester resin is greater than 30, the charge amount under the toner use environment is not stable. The polyester resin having an acid value of 3 to 30 KOHmg / g becomes an anionic type by neutralizing the carboxyl group with a basic compound. As a result, the hydrophilicity of the resin increases and can be dissolved or dispersed stably.

  Examples of the basic compound for neutralization include inorganic bases such as sodium hydroxide, potassium hydroxide, and ammonia, and organic bases such as diethylamine, triethylamine, and isopropylamine. In particular, an aqueous solution of an inorganic base such as sodium hydroxide, potassium hydroxide or ammonia is preferred.

  The emulsified suspension produced by the above-described method exists in a state where the colored resin solution is emulsified in an aqueous medium. The state varies depending on the type of organic solvent, the amount used, the acid value of the binder resin, the amount of basic compound used, the stirring conditions, etc., but the dispersoids such as resin oil droplets, wax dispersoids, colorant dispersoids, etc. It is preferable to emulsify as oil droplets having a particle size of less than 1 μm. Such a state is preferable because the stability of the emulsified suspension, the unitary stability in the subsequent steps, the particle size distribution of the colored resin fine particles, and the like are improved.

Next, the unification process which is the 3rd process is explained. By adding the electrolyte, the dispersoid is salted out or destabilized, and the dispersoids are integrated with each other, so that coalescence progresses to produce colored resin fine particles.
Examples of the electrolyte used here include organic and inorganic substances such as sodium sulfate, ammonium sulfate, potassium sulfate, magnesium sulfate, sodium phosphate, sodium dihydrogen phosphate, sodium chloride, potassium chloride, ammonium chloride, calcium chloride, and sodium acetate. A water-soluble salt or the like can also be used effectively as an electrolyte. These electrolytes to be added for unity may be used alone or in combination of two or more kinds. Among them, monovalent cation sulfates such as sodium sulfate and ammonium sulfate are preferable for promoting uniform coalescence.

  Moreover, since the colored resin fine particles obtained are swollen by a solvent and the hydration state of the particles is unstable due to the addition of an electrolyte, the particles are caused to collide with each other by stirring with low shearing force. It is preferable to proceed one. It is preferable to proceed the coalescence under a low shearing force such that only the coalescence proceeds without causing the splitting of the colored resin fine particles.

  In order to promote uniform coalescence, the stirring conditions at the time of coalescence are weight, for example, anchor blade, turbine blade, fowler blade, full zone blade, Max blend blade (registered trademark, manufactured by Sumitomo Heavy Industries), half moon blade, etc. Is used. Among them, it is preferable to use a large wing that is excellent in uniform mixing properties even at a low rotation, such as a Max blend wing or a full zone wing.

The peripheral speed of the stirring blade for generating a uniform unity is preferably 0.2 to 10 m / s, and more preferably stirring at a low shear of 0.2 to 8 m / s. In particular, 0.2 to 6 m / s is preferable. If the peripheral speed of the stirring blade is higher than 10 m / s, fine particles remain, which is not preferable. On the other hand, if the peripheral speed is less than 0.2 m / s, stirring is not uniform and coarse particles are generated, which is not preferable. Under the above-described conditions, coalescence proceeds only by collision between the colored resin fine particles, and the colored resin fine particles are not dissociated and dispersed. In particular, in the coalescing process, the generation of fine particles is small and a narrow particle size distribution can be obtained.
That is, it is preferable to stir with a high-speed stirrer such as a desper in the colored resin solution preparation step and the emulsification step, and a large blade that can be uniformly mixed at a low speed such as a max blend blade is suitable in the coalescence step. For this reason, it is preferable to carry out the coalescing step by transferring the emulsified suspension obtained in the emulsifying step to another container attached to the large blade.

Moreover, 0.5-15 mass% is preferable with respect to solid content, and, as for the quantity of the electrolyte to be used, it is more preferable that it is 1-12 mass%, and it is especially preferable that it is 1-6 mass%. When the amount of the electrolyte is less than 0.5% by mass, coalescence does not proceed sufficiently. If the amount is more than 15% by mass, it is not preferable because a large amount of stop water is required in the subsequent process, and it takes time for washing and drying.
Moreover, 1-15 mass% is preferable and, as for the density | concentration of electrolyte solution, it is more preferable that it is 3-10 mass%. If the amount is less than 1% by mass, the effect of the electrolyte is not sufficiently exhibited, and a large amount of electrolyte is required for salting out and coalescence. Or, colored resin fine particles may not be generated. On the other hand, if it is higher than 15% by mass, unevenness is likely to occur in the system, and in particular, aggregates and coarse particles are likely to be generated during the formation of colored resin fine particles in the initial stage of coalescence, which is not preferable.

  In the coalescing step, when the electrolyte solution is added, it is preferable to increase the stirring speed in order to uniformly and quickly mix the electrolyte into the system. The temporary temperature is preferably in the range of 10 to 50 ° C. More preferably, it exists in the range of 20-40 degreeC, and it is especially preferable that it is 20-35 degreeC. When the temperature is lower than 10 ° C., it is difficult to perform coalescence, which is not preferable. On the other hand, when the temperature is higher than 50 ° C., the coalescence speed is increased, and aggregates and coarse particles are easily generated, which is not preferable. In the production method of the present invention, for example, direct planting by coalescence and generation of fine particles are possible under low temperature conditions such as 20 to 40 ° C.

In unification, the colored resin fine particles swollen by the organic solvent collide with each other, and the fine particles are fused together to grow.
Moreover, since particle growth maintains a substantially constant growth rate under a certain condition, it can be expressed by creating a particle growth curve blotted from time and particle size. As a result, the arrival time of the target particle diameter can be estimated from the curve. Moreover, it is preferable to stop coalescence by adding water.

  In order to perform solvent removal rapidly under low temperature conditions, it is preferable to carry out under reduced pressure. In removing the solvent, an antifoaming agent is preferably added. The antifoaming agent is preferably in the form of a silicone emulsion. Examples of silicone-based antifoaming agents include BY22-517, SH5503, SM5572F, BY28-503 (manufactured by Toray Dow Corning Silicone), KM75, KM89, KM98, KS604, KS538 (manufactured by Shin-Etsu Chemical Co., Ltd.), and the like. . Of these, BY22-517 is preferred as having little influence on physical properties and a high defoaming effect. The amount of the antifoaming agent is preferably 30 to 100 ppm with respect to the solid content.

The toner particles produced by the production method of the present invention are characterized in that a colorant, wax, etc. are encapsulated in a binder resin, and the colorant, wax, etc. are observed by observation with a transmission electron microscope or the like. It can be confirmed that the particles are contained in the particles and are dispersed almost uniformly.
Further, the shape of the colored resin fine particles obtained in the coalescing step is determined by a particle image analyzer (flow type particle image analyzer FPIA-3000 manufactured by Sysmex) or the like, and the circularity corresponds to the projected area of the observed particle image. The average circularity, which is the average value of the numerical values expressed by the ratio of the circumference of the circle to be observed and the circumference of the observed projected image of the particle.
Regarding the shape of the toner particles, the average circularity is preferably 0.95 or more, more preferably 0.96 or more, and further preferably 0.97 or more. This is because powder fluidity is improved and transfer efficiency is improved by making the average circularity into a substantially spherical shape or a spherical shape with 0.97 or more.

  Next, in the separation / drying step as the fourth step, the colored resin fine particles are separated, washed and dehydrated. Separation from the aqueous medium can be performed by a separation means such as a centrifuge, a filter press, or a belt filter. Next, toner base particles can be obtained by drying the particles. Drying is a fluidized bed dryer such as a ribocorn dryer (Okawara Seisakusho), a mixed vacuum dryer such as Nauta Mixer (Hosokawa Micron), a fluidized bed dryer (Okawara Seisakusho), or a vibrating fluidized bed dryer (central processing machine). However, the present invention is not limited to these dryers.

As for the particle size distribution of the toner, it is preferable that the 50% volume particle size / 50% number particle size is 1.25 or less as measured by a multisizer type II (aperture tube diameter: 100 μm) manufactured by Beckman Coulter. More preferably, it is 20 or less. This is because it is easy to obtain a good image when it is 1.25 or less.
The preferred volume average particle size of the toner is 8 μm or less. When the conditions for adjusting the wax master solution are defined, the volume average particle diameter of the toner is set in the range of 1.5 to 4 μm. As the particle size of the toner decreases, the resolution and gradation are improved, the thickness of the toner layer forming the printed image is reduced, the amount of heat required for fixing is reduced, and at the same time the toner consumption is reduced.

In the present invention, the binder resin is not particularly limited, but a polyester resin is preferably used. The polyester resin used in the present invention is a cross-linked polyester resin or a linear polyester resin, and is obtained by reacting a compound selected from the following raw materials.
The crosslinked polyester is preferably produced by reacting a divalent basic acid or derivative thereof, a divalent alcohol, and a polyvalent compound as a crosslinking agent. In particular, it is preferable to produce by reacting a divalent basic acid or a derivative thereof, a divalent aliphatic polyhydric alcohol, and a polyvalent epoxy compound as a crosslinking agent.
The linear polyester resin is produced by reacting a divalent basic acid with a dihydric alcohol.

  Examples of the divalent basic acids used in producing the crosslinked polyester resin and the linear polyester resin include phthalic anhydride, terephthalic acid, isophthalic acid, orthophthalic acid, adipic acid, maleic acid, maleic anhydride, Examples thereof include dicarboxylic acids such as fumaric acid, itaconic acid, citraconic acid, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, cyclohexanedicarboxylic acid, succinic acid, malonic acid, glutaric acid, azelaic acid, sebacic acid, and derivatives thereof.

  Examples of the divalent aliphatic alcohol component include 1,4-cyclohexanedimethanol, ethylene glycol, diethylene glycol, propylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, neopentyl glycol, butanediol, and pentanediol. Hexanediol, polyethylene glycol, polypropylene glycol, ethylene oxide-propylene oxide random copolymer diol, ethylene oxide-propylene oxide block copolymer diol, ethylene oxide-tetrahydrofuran copolymer diol, polycaprocactone diol, etc. Diols are mentioned.

  Use of an aliphatic alcohol in the cross-linked polyester resin and the linear polyester resin is preferable because compatibility with waxes is improved and offset resistance is improved. Moreover, fixing property at low temperature is improved by softening the polyester main chain. When producing a crosslinked polyester resin, a polyvalent epoxy compound is further used as a crosslinking agent. Examples of such compounds include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, ethylene glycol diglycidyl ether, hydroquinone diglycidyl ether, N, N-diglycidyl aniline lysine triglycidyl ester, Trimethylolpropane triglycidyl ether, trimethylolethane triglycidyl ether, pentaerythritol tetraglycidyl ether, tetrakis 1,1,2,2 (P-hydroxyphenyl) ethane tetraglycidyl ether, cresol novolac epoxy resin, phenol novolac epoxy resin A polymer or copolymer of an epoxy group-containing vinyl compound, an epoxidized resorcinol-acetone condensate, a partial epoxy Polybutadiene, polymers of vinyl compounds having an epoxy group, or a copolymer, such as semi-drying or drying fatty acid ester epoxy compound. Among the above compounds, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, cresol novolac type epoxy resin, phenol novolac type epoxy resin, glycerin / triglycidyl ether, trimethylolpropane triglycidyl ether, trimethylol Ethanetriglycidyl ether and pentaerythritol tetraglycidyl ether are more preferably used.

  Specific examples of bisphenol A type epoxy resins include Dainippon Ink Chemical Co., Ltd. Epicron 850, Epicron 1050, Epicron 2055, Epicron 3050, and the like. Epicron 830, Epicron 520, etc. manufactured by Dainippon Ink & Chemicals, Inc. as examples of orthocresol novolac type epoxy resins, N-660, N-665, N-667, N-670, N- 673, N-680, N-690, N-695, etc. are examples of phenol novolac type epoxy resins. Epiklon N-740, N-770, N-775, N-manufactured by Dainippon Ink & Chemicals, Inc. 865 etc. As a polymer or copolymer of a vinyl compound having an epoxy group, Examples thereof include a homopolymer of glycidyl (meth) acrylate, an acrylic copolymer, and a copolymer with styrene.

Moreover, the epoxy compound mentioned above can also be used in combination of 2 or more types, Furthermore, the mono epoxy compound described below can also be used together as a modifier | denaturant of resin. Examples of the monoepoxy compound that can be used at the same time include phenyl glycidyl ether, alkylphenyl glycidyl ether, alkyl glycidyl ether, alkyl glycidyl ester, glycidyl ether of alkylphenol alkylene oxide adduct, α-olefin oxide, monoepoxy fatty acid alkyl ester, etc. Is mentioned.
By using these monoepoxy compounds in combination, fixability and resistance to offset at high temperatures are improved. Among these, alkyl glycidyl esters are particularly preferably used. A specific example is Cardura E (Neodecanoic acid glycidyl ester manufactured by Shell Japan).

The cross-linked polyester resin and the linear polyester resin can be obtained, for example, by performing a dehydration condensation reaction or a transesterification reaction in the presence of a catalyst using the raw material components described above. The reaction temperature and reaction time at this time are not particularly limited, but are usually 150 to 300 ° C. and 2 to 24 hours.
As the catalyst for performing the above reaction, for example, tetrabutyl titanate, zinc oxide, stannous oxide, dibutyltin oxide, dibutyltin dilaurate, paratoluenesulfonic acid, and the like can be used as appropriate.

  When a mixture of a crosslinked polyester resin and a linear polyester resin is used in the present invention, the mixing ratio is not particularly limited, but (mass of crosslinked polyester resin) / (mass of linear polyester resin) = 5 / 95 to 60/40 is preferable, 10/90 to 40/60 is more preferable, and 20/80 to 40/60 is particularly preferable. When the ratio of the cross-linked polyester resin is less than 5% by mass, the hot offset resistance, the coalescence speed, and the dispersibility of wax, colorant and the like are not preferable. On the other hand, when the ratio of the cross-linked polyester resin is more than 60% by mass, the melt viscosity (T1 / 2 temperature) increases and the low-temperature fixability decreases, which is not preferable.

  The glass transition temperature (Tg) of the cross-linked polyester resin is not particularly limited, but is preferably 40 to 85 ° C, and particularly preferably 60 to 80 ° C. When the glass transition temperature (Tg) is lower than 40 ° C., a blocking phenomenon (thermal aggregation) tends to occur when the toner is stored, transported, or exposed to a high temperature inside the developing device of the machine. Further, if the glass transition temperature (Tg) is higher than 85 ° C., the low-temperature fixability is lowered, which is not preferable.

  Although the glass transition temperature (Tg) of a linear polyester resin is not specifically limited, It is preferable that it is 35-70 degreeC, and it is especially preferable that it is 50-65 degreeC. When the glass transition temperature (Tg) is lower than 35 ° C., a blocking phenomenon (thermal aggregation) tends to occur when the toner is stored, transported, or exposed to a high temperature inside the developing device of the machine. Further, if the glass transition temperature (Tg) is higher than 70 ° C., the low-temperature fixability is lowered, which is not preferable.

  The softening point of the cross-linked polyester resin is not particularly limited, but is preferably 150 ° C or higher, more preferably 150 ° C to 220 ° C, and particularly preferably 170 ° C to 190 ° C. This is because when the softening point is less than 150 ° C., the toner tends to cause an aggregation phenomenon, so that trouble is likely to occur during storage or printing, and when it exceeds 220 ° C., the fixability is likely to deteriorate. is there.

  The softening point of the linear polyester resin is not particularly limited, but is preferably 90 ° C. or higher, more preferably 90 ° C. to 130 ° C., and particularly preferably 90 ° C. to 110 ° C. . As with the cross-linked polyester resin, when the softening point is less than 90 ° C., the glass transition temperature is lowered, and the toner tends to cause aggregation phenomenon, which is likely to cause trouble during storage or printing. If the temperature exceeds 130 ° C., the fixability tends to deteriorate.

The softening point of the polyester resin in the present invention is a T1 / 2 temperature measured using a constant load extrusion capillary type rheometer (Shimadzu Corporation flow tester CFT-500). The measurement was performed under the conditions of a piston cross-sectional area of 1 cm ² , a cylinder pressure of 0.98 MPa, a die length of 1 mm, a die hole diameter of 1 mm, a measurement start temperature of 50 ° C., a temperature increase rate of 6 ° C./min, and a sample mass of 1.5 g. .
Moreover, the measurement of the glass transition temperature (Tg) of a polyester resin is measured using DSC (Shimadzu DSC-60A). 20 mg of sample is put in an aluminum crimp cell, heated to 180 ° C. at a heating rate of 10 ° C./min, cooled to room temperature at a cooling rate of 10 ° C./min from 180 ° C., and again to 180 ° C. at a heating rate of 10 ° C./min. The temperature rise and the second run value are Tg.

  The colored resin solution can be prepared by mixing a charge control agent. The positively chargeable charge control agent is not particularly limited, and known and commonly used nigrosine dyes, quaternary ammonium compounds, onium compounds, triphenylmethane compounds and the like can be used for toners. In addition, basic group-containing compounds such as amino groups, imino groups, and N-heterocycles, such as tertiary amino group-containing styrene acrylic resins, are also effective as a positively chargeable charge control agent. As a control agent, it can be used alone or in combination with the positively chargeable charge control agent. Depending on the application, a small amount of a negative charge control agent such as an azo dye metal complex or a salicylic acid derivative metal complex salt may be used in combination with these positively chargeable charge control agents. In addition, as the negatively chargeable charge control agent, heavy metals such as trimethylethane dyes, salicylic acid metal complexes, benzylic acid metal complexes, copper phthalocyanine, perylene, quinacridone, azo pigments, metal complex azo dyes, azochrome complexes, etc. Examples thereof include acidic dyes, calixarene-type phenol condensates, cyclic polysaccharides, resins containing carboxyl groups and / or sulfonyl groups, and the like. The content of the charge control agent is preferably 0.01 to 10% by mass, and particularly preferably 0.1 to 6% by mass with respect to the whole toner.

  Examples of the colorant that can be added in the colored resin solution preparation step include C.I. I. Pigment Black 11 and other iron oxide pigments, C.I. I. Examples thereof include iron-titanium complex oxide pigments such as Pigment Black 12, and carbon black such as furnace black, channel black, acetylene black, thermal black, and lamp black.

  Examples of blue colorants include phthalocyanine C.I. I. Pigment Blue 1, 2, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 15, 16, 17: 1, 27, 28, 29, 56, 60, 63 and the like. Among these, C.I. I. Pigment Blue 15: 3, 15, 16, 60 are preferable. I. Pigment Blue 15: 3, 60 is more preferable.

  Examples of yellow colorants include C.I. I. Pigment Yellow 1, 3, 4, 5, 6, 12, 13, 14, 15, 16, 17, 18, 24, 55, 65, 73, 74, 81, 83, 87, 93, 94, 95, 97, 98 , 100, 101, 104, 108, 109, 110, 113, 116, 117, 120, 123, 128, 129, 133, 138, 139, 147, 151, 153, 154, 155, 156, 168, 169, 170 , 171, 172, 173, 180, 184, 185 and the like. Among these, C.I. I. Pigment Yellow 17, 74, 93, 97, 110, 155, 180, 184 are preferable. I. Pigment Yellow 74, 93, 97, 180 are more preferable. I. Pigment Yellow 93, 97, 180, and 184 are more preferable.

  Examples of red colorants include C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 15, 17, 18, 22, 23, 31, 37, 38, 41, 42, 48: 1, 48 : 2, 48: 3, 48: 4, 49: 1, 49: 2, 50: 1, 52: 1, 52: 2, 53: 1, 54, 57: 1, 58: 4, 60: 1, 63 : 1, 63: 2, 64: 1, 65, 66, 67, 68, 81, 83, 88, 90, 90: 1, 112, 114, 115, 122, 123, 133, 144, 146, 147, 149 , 150, 151, 166, 168, 170, 171, 172, 174, 175, 176, 177, 178, 179, 184, 185, 187, 188, 189, 190, 193, 194, 202, 208, 209, 214 216, 220, 221, 2 4,242,243,243: 1,245,246,247, and the like. Among these, C.I. I. Pigment Red 48: 1, 48: 2, 48: 3, 48: 4, 53: 1, 57: 1, 122, 184, 209 are preferred. I. Pigment Red 57: 1, 122, 184, and 209 are more preferable.

  The content of the colorant is preferably 1 to 20% by mass, more preferably 2 to 18% by mass, and still more preferably 2 to 15% by mass with respect to the whole toner. These colorants can be used alone or in combination of two or more.

The toner particles produced by the production method of the present invention can be adjusted in fluidity, electrostatic property, etc. by adding fine particles such as silica and titania or those hydrophobized to these as external additives. The obtained toner particles can be used as a one-component toner, but can also be used as a two-component toner by mixing a carrier.
EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

(Synthesis of cross-linked polyester resin)
Terephthalic acid 221 parts by mass Isophthalic acid 95 parts by mass Neopentyl glycol 104 parts by mass Ethylene glycol 62 parts by mass Tetrabutyl titanate 2.5 parts by mass Epicron 830 7 parts by mass (Dai Nippon Ink Chemical Co., Ltd. bisphenol F type epoxy resin Epoxy Equivalent 170 g / eq)
3 parts by weight of Cardura E (Shell Japan alkyl glycidyl ester epoxy equivalent 250 g / eq)
The above raw materials were put into a stainless steel 50 L reaction kettle and reacted at 240 ° C. for 10 hours under a normal pressure nitrogen stream. Thereafter, the pressure was reduced successively and the reaction was continued at 10 mmHg. The reaction was followed by the softening point specified in ASTM E28-517, and the reaction was terminated when the softening point reached 160 ° C. The obtained polymer was a colorless solid having an acid value of 11.0, a glass transition temperature of 64 ° C. by DSC measurement method, and a softening point (T1 / 2) by a flow tester of 175 ° C. The polymer is hereinafter referred to as “H1”.

(Synthesis of linear polyester resin)
Terephthalic acid 315 parts by mass Neopentyl glycol 21 parts by mass Ethylene glycol 12 parts by mass Propylene glycol 122 parts by mass Tetrabutyl titanate 2.5 parts by mass or more of raw materials are placed in a stainless steel 50 L reaction kettle and 240 under a normal pressure nitrogen stream. After the reaction at 12 ° C. for 12 hours, the pressure was reduced successively and the reaction was continued at 10 mmHg. The reaction was followed by the softening point specified in ASTM E28-517, and the reaction was terminated when the softening point reached 100 ° C. The obtained polymer was a colorless solid having an acid value of 10.0, a glass transition temperature of 57 ° C. by DSC measurement method, and a softening point (T1 / 2) by a flow tester of 102 ° C. The polymer is hereinafter referred to as “L2”.

(Preparation of wax emulsion)
Carnauba wax No. 1 (Yoko Kato import) 30 parts by mass was heated to 120 ° C. and melted, and 57 parts by mass of ion-exchanged water was added with 0.11 mass of emulsifier Neogen SC-F (Daiichi Kogyo Co., Ltd.). Carnauba wax melted in an emulsifier mixed warm water heated to 90 ° C. was added and emulsified with a forced emulsifier TK homomixer (manufactured by Primix Co., Ltd.). Thereafter, the mixture was cooled to 30 ° C. or lower with stirring, and adjusted to a solid content of 35% by mass to obtain a wax emulsion (WE1).

(Preparation of wax master solution 1)
70 parts by mass of the linear polyester resin L2 was dispersed in 85.6 parts by mass of methyl ethyl ketone using Desper (manufactured by Asada Iron Works Co., Ltd.) for 60 minutes at a rotational speed of 750 min ⁻¹ , and then a wax emulsion (WE1 ) 87.9 parts by mass were charged and dispersed and premixed for 5 minutes at a rotation speed of 750 min ^-1 with a desper, and then Table 1-Example 1 using an Eiger motor mill (M-1000 manufactured by Eiger, USA). And a wax master solution (WM1) was obtained by wet dispersion.

(Preparation of wax master solution 2)
After dispersing 9.0 parts by mass of linear polyester resin L2 in 11.0 parts by mass of methyl ethyl ketone using Desper (manufactured by Asada Iron Works Co., Ltd.) for 60 minutes at a rotational speed of 750 min ⁻¹ , wax emulsion (WE1) 11.26 parts by mass were charged and dispersed and premixed for 5 minutes at a rotation speed of 750 min ⁻¹ with a desper, and then subjected to LMZ10 bead mill (Ashizawa Co., Ltd.) under the conditions shown in Table 1-Example 2. To obtain a wax master solution (WM2).

(Preparation of wax master solution 3)
After 9.2 parts by mass of the linear polyester resin L2 was dispersed in 10.5 parts by mass of methyl ethyl ketone using Desper (manufactured by Asada Iron Works Co., Ltd.) at a rotational speed of 750 min ⁻¹ for 60 minutes, a wax emulsion (WE1) 11.3 parts by mass were charged and dispersed and premixed for 5 minutes at a rotation speed of 750 min ⁻¹ with a desper, and then subjected to LMZ10 bead mill (Ashizawa Corp.) under the conditions shown in Table 1-Example 3. To obtain a wax master solution (WM3).

(Preparation of wax master solution 4)
8.5 parts by mass of linear polyester resin L2 was dispersed in 12.0 parts by mass of methyl ethyl ketone using Desper (made by Asada Iron Works Co., Ltd.) at a rotational speed of 750 min ⁻¹ for 60 minutes, and then a wax emulsion. (WE1) 10.46 parts by mass were charged and dispersed and premixed for 5 minutes at a rotation speed of 750 min ⁻¹ with a desper, and then subjected to LMZ10 bead mill (Ashizawa Corp.) under the conditions shown in Table 1-Example 4. To obtain a wax master solution (WM4).

(Preparation of wax master solution 5)
10.8 parts by mass of the linear polyester resin L2 was dispersed in 7.0 parts by mass of methyl ethyl ketone using Desper (manufactured by Asada Iron Works Co., Ltd.) for 60 minutes at a rotational speed of 750 min ⁻¹ , and then a wax emulsion. (WE1) 13.2 parts by mass were charged and dispersed and premixed for 5 minutes at a rotation speed of 750 min ⁻¹ with a desper, and then subjected to LMZ10 bead mill (Ashizawa Co., Ltd.) under the conditions shown in Table 1-Example 5. To obtain a wax master solution (WM5).

(Preparation of wax master solution 6)
After dispersing 7.5 parts by mass of the linear polyester resin L2 in 14.3 parts by mass of methyl ethyl ketone using a desper (manufactured by Asada Iron Works Co., Ltd.) for 60 minutes at a rotational speed of 750 min ⁻¹ , a wax emulsion (WE1) 9.2 parts by mass were charged and dispersed and premixed for 5 minutes at a rotation speed of 750 min ⁻¹ with a desper, and then subjected to LMZ10 bead mill (Ashizawa Corp.) under the conditions shown in Table 1-Example 6. To obtain a wax master solution (WM6).

(Preparation of wax master solution 7)
After 8.9 parts by mass of the linear polyester resin L2 was dispersed in 11.2 parts by mass of methyl ethyl ketone for 60 minutes using a desper (manufactured by Asada Iron Works Co., Ltd.) at a rotation speed of 750 min ⁻¹ , a wax emulsion (WE1) 10.9 parts by mass were charged and dispersed and premixed for 5 minutes at a rotation speed of 750 min ⁻¹ with a desper, and then subjected to LMZ10 bead mill (Ashizawa Corporation) under the conditions shown in Table 1-Comparative Example 1. To obtain a wax master solution (WM7).

(Preparation of wax master solution 8)
After dispersing 9.0 parts by mass of linear polyester resin L2 in 18.4 parts by mass of methyl ethyl ketone using Desper (Asada Iron Works Co., Ltd.) at a rotational speed of 750 min ⁻¹ for 60 minutes, a wax emulsion (WE1) 11.0 parts by mass were charged and dispersed and premixed for 5 minutes at a rotation speed of 750 min ⁻¹ with a desper, and then subjected to the LMZ10 bead mill (Ashizawa Corp.) under the conditions shown in Table 1-Comparative Example 2. To obtain a wax master solution (WM8).

(Preparation of wax master solution 9)
19.5 parts by mass of the linear polyester resin L2 was dispersed in 26.3 parts by mass of methyl ethyl ketone using Desper (manufactured by Asada Iron Works Co., Ltd.) at a rotational speed of 750 min ⁻¹ for 60 minutes, and then a wax emulsion (WE1) 23.9 parts by mass were added, and after dispersion premixed for 5 minutes at a rotation speed of 750 min ⁻¹ with a desper, a bead mill LMZ10 bead mill (Ashizawa Corp.) under the conditions shown in Table 1-Comparative Example 3 ) To obtain a wax master solution (WM9).

(Preparation of wax master solution 10)
After 8.9 parts by mass of the linear polyester resin L2 was dispersed in 11.1 parts by mass of methyl ethyl ketone for 60 minutes using a desper (manufactured by Asada Iron Works Co., Ltd.) at a rotational speed of 750 min ⁻¹ , a wax emulsion (WE1) 10.9 parts by mass were added, and after dispersion premixed for 5 minutes at a rotation speed of 750 min ⁻¹ with a desper, LMZ10 bead mill (Ashizawa Corp.) under the conditions shown in Table 1-Comparative Example 4 To obtain a wax master solution (WM10).

(Preparation of colorant master chip)
20L Henschel set with 2000 parts by mass of Ket Blue 111 (Cyan Pigment, CI Pigment B-15: 3, manufactured by Dainippon Ink and Chemicals, Inc.) and 2000 parts by mass of linear polyester resin L2 with ST / A0 blades The mixture was put into a mixer (manufactured by Mitsui Mining Co., Ltd.) and stirred for 2 minutes at 698 min ⁻¹ to obtain a mixture. The mixture was melt-kneaded using a kneedex MOS140-800 (an open roll continuous extrusion kneader manufactured by Mitsui Mining Co., Ltd.) to prepare a master chip.

Example 1
A toner was manufactured as follows. In addition, about the process (process) in which temperature conditions are not described, it performed at room temperature (25 degreeC).
(Preparation of colored resin solution (MB-1))
42 parts by weight of a colorant master chip, 49.8 parts by weight of a cross-linked polyester resin H1, 108.2 parts by weight of a linear polyester resin L2, and 159.9 parts by weight of methyl ethyl ketone have a blade diameter of 9 inches within a range of 40 to 45 ° C. Using a disper (manufactured by Asada Iron Works Co., Ltd.), the mixture was mixed at 777 min ⁻¹ for 1 hour, and dissolved and dispersed.
Methyl ethyl ketone is further added to the obtained mixture to adjust the solid content to 65% by mass, and 1.1 parts by mass of dodecylbenzenesulfonic acid emulsifier Neogen SC-F (Daiichi Kogyo Seiyaku Co., Ltd.) is added. After adding, dissolving and dispersing, 243.6 parts by mass of the above wax master solution (WM1) was added and dispersed for 30 minutes with a desper to prepare a colored resin solution (MB-1).

(Emulsification process)
A cylindrical container having a blade with a blade diameter of 230 mm as a stirring blade is charged with 603.5 parts by weight of a colored resin solution (MB-1) (solid content 300.8 parts by weight), and then 40 parts by weight of 1N ammonia water is added. The temperature was adjusted to 35 ° C. after stirring at 777 min ⁻¹ . Subsequently, the stirring speed was changed to 1100 min ⁻¹ and 534.7 parts by mass of deionized water was added dropwise at 20 parts by mass / min to prepare an emulsified suspension. The peripheral speed of the stirring blade at this time was 13.2 m / s. As deionized water was added, the viscosity of the system increased, but water was taken into the system at the same time as the dropwise addition, and stirring and mixing were uniform. After adding 200 parts by weight of deionized water, a sharp drop in viscosity was observed (phase inversion emulsification). Further, when a predetermined amount of the remaining deionized water was added and the slurry was observed with an optical microscope, it was observed that the resin was dissolved and the pigment and wax fine particles were dispersed. No unemulsified material was observed. Since the pigment and wax fine particles are stably dispersed in the aqueous medium, it is considered that the resin is adsorbed on the surfaces of the fine particles. At this time, the methyl ethyl ketone ratio in all the solutions in the system was 27.7% by mass.

(Joint process)
Next, the emulsified suspension was transferred to a cylindrical vessel attached to a Max Blend blade (registered trademark, manufactured by Sumitomo Heavy Industries, Ltd.) having a blade diameter of 340 mm, and the temperature was maintained at 26 ° C. while maintaining the stirring speed at 85 min ^−1. Adjusted. Thereafter, the rotational speed was adjusted to 120 min ⁻¹ , 120 parts by mass of a 3.5 mass% sodium sulfate aqueous solution was added dropwise at 10 parts by mass / min, and 5 minutes after the completion of dropping, the rotational speed was 85 min ⁻¹ for 5 minutes and 65 min. ^The mixture was stirred for 5 minutes at ^-1 and continued for 20 minutes at 47 min- ¹ . The peripheral speed of the stirring blade at this time was 0.47 m / s. Subsequently, the rotational speed was adjusted to 120 min ⁻¹ , 2 parts by mass of a sodium sulfate aqueous solution having a concentration of 5.0% by mass was dropped at 10 parts by mass / min, and 5 minutes after the completion of dropping, the rotational speed was 85 min ⁻¹ for 5 minutes. Stirring was performed at 65 min ⁻¹ for 5 minutes, and stirring was continued at 47 min ⁻¹ for 20 minutes. Thereafter, an operation of dropping and stirring a sodium sulfate aqueous solution having a concentration of 5.0% by mass was repeated three times, and diluting water was added when the particle diameter had grown to 5.8 μm to complete the coalescence operation.

(Separation and drying process)
After adding 0.068 parts by mass of antifoaming agent BY22-517 (manufactured by Toray Dow Corning Silicone Co., Ltd.), methyl ethyl ketone and water were distilled off under reduced pressure until the degree of vacuum was 4 kPa. The slurry after the solvent removal was repeatedly washed by solid-liquid separation and redispersion, and then a colored resin fine particle dispersion obtained by removing the solvent with a basket type centrifuge was obtained. Thereafter, the mixture was dried with a Nauta mixer (manufactured by Hosokawa Micron Corporation) to obtain toner mother particles. The toner base particles had a 50% volume average particle size of 5.0 μm, a 50% volume average particle size / 50% number average particle size of 1.07, and an average circularity of 0.980.

(External addition process)
1 part by mass of silica H13TM (manufactured by Clariant Japan) was added to 100 parts by mass of the toner base particles, and the toner was treated at 35 m / sec for 5 minutes with a Henschel mixer to obtain an electrostatic charge image developing toner.

(Example 2)
A toner was manufactured as follows. In addition, about the process (process) in which temperature conditions are not described, it performed at room temperature (25 degreeC).
(Preparation of colored resin solution (MB-2))
8.6 parts by mass of methyl ethyl ketone was charged into a stainless steel container, and the resin H1 (diluted resin) was stirred while stirring at a rotation speed of 500 min ^-1 (blade tip speed: 5.5 m / sec) using a stirrer (Desper blade diameter 230 mm, manufactured by Asada Iron Works). ) 4.48 parts by weight were added. Thereafter, the rotation speed of the stirring blade was 777 min ⁻¹ (blade tip speed: 8.5 m / sec), 3.78 parts by mass of the colorant master chip, 9.74 parts by mass of resin L2 (diluted resin), and wax master 20 parts by weight of the dispersion (preparation 2 of the above wax master solution) and 0.1 parts by weight of sodium dodecylbenzenesulfonate as an emulsifier were put in this order in the container, whereby each component Was dissolved and dispersed. Thereafter, methyl ethyl ketone was additionally added so that the solid content was 65% by mass to obtain a mill base (MB-2). In addition, the material temperature at the time of stirring was hold | maintained at 30-40 degreeC.

(Emulsification process)
A cylindrical container equipped with a stirrer (Desper made by Asada Iron Works) having a stirring blade with a blade diameter of 230 mm was charged with 46.85 parts by mass of the colored resin solution (MB-2) (solid content 27 parts by weight) and then a base. As a functional compound, 5 parts by mass of 1N ammonia water was added, and after sufficiently stirring at 777 min ⁻¹ , the temperature was adjusted to 30 ° C.
Subsequently, the stirring speed was changed to 1100 min ⁻¹ and 35.77 parts by mass of water was added dropwise at a rate of 1.5 parts by mass / min. At this time, the blade tip speed of the stirring blade was 13.2 m / s. As water was added, the viscosity of the system increased, but water was taken into the system at the same time as dropping, and stirring and mixing could be performed uniformly. An emulsion suspension was obtained as described above.

(Joint process)
The emulsified suspension was transferred to a cylindrical container attached to Max Blend Wing (registered trademark) with a blade diameter of 340 mm, and then the temperature was adjusted to 25 ° C. while stirring at a stirring speed (number of rotations) of 85 min ⁻¹ . . Thereafter, the rotational speed was adjusted to 120 min ⁻¹ , 10.8 parts by mass of a 3.5 mass% sodium sulfate aqueous solution was added dropwise at 1 part by mass / min, and 5 minutes after the completion of dropping, the rotational speed was 5 min at 85 min ⁻¹ . The mixture was stirred for 5 minutes at 65 min ⁻¹ for 5 minutes and continuously stirred for 20 minutes at 47 min ⁻¹ . The blade tip speed of the stirring blade at this time was 0.47 m / s. Subsequently, the rotational speed of the stirring blade was adjusted to 120 min ⁻¹ , and 2.5 parts by mass of a 5.0 mass% sodium sulfate aqueous solution was dropped at 1 part by weight / min. Was stirred at 85 min ⁻¹ for 5 minutes and 65 min ⁻¹ for 5 minutes. Then, stirring was continued with the rotation speed of the stirring blade set to 47 min ⁻¹ , and when the particle size reached 3.60 μm, stirring was performed for 30 minutes with the rotation speed of the stirring blade set to 85 min ⁻¹ , and the desired coalesced particles were dispersed. A colored resin fine particle dispersion was obtained. The particle size was measured with a Coulter Counter Multisizer TAII (Beckman Coulter, Inc.) using a 100 μm aperture tube.

(Desolvation process)
Thereafter, 0.068 parts by mass of a silicone-based antifoaming agent (BY22-517 manufactured by Toray Dow Corning Silicone Co., Ltd.) was added, the container used for the reaction was sealed, and a vacuum pump was attached.
Next, at room temperature (25 ° C.), the solvent was removed by reducing the pressure for 30 minutes at a pressure of 2.7 kPa using a vacuum pump.
Next, while lowering the pressure, the vessel used for the reaction was heated for 90 minutes, and the internal material temperature was increased at a rate of 4 ° C./hour until the material temperature in the vacuum vessel reached 21 ° C. did. After 90 minutes, when the internal material temperature reached 21 ° C., the pressure was continuously reduced under the same pressure while maintaining the same temperature. The liquid distilled off under reduced pressure was reduced in pressure until the methyl ethyl ketone used was 138% by volume to obtain colored resin fine particle slurry. At this time, the final pressure was 1.0 kPa.

(Dedispersing medium process)
The slurry obtained as described above was subjected to a dedispersion medium at a peripheral speed of 1250 min ⁻¹ using a basket type centrifuge. After performing the dedispersion medium, while continuously rotating the basket-type centrifuge at the same peripheral speed, water of 6 times the solid content (in terms of mass) in the slurry is added, and washing is simply performed (hereinafter referred to as rinsing). And the water was shaken off to obtain a colored resin fine particle cake.

(Washing and dehydration process)
The colored resin fine particle cake was placed in the stirring tank of the stirring device. Water was added so that the solid content in the colored resin fine particle cake in the stirring tank was 15 to 20% by mass, and the temperature was controlled so that the water temperature was 30 ° C. In this state, an edged turbine blade was used as a stirring blade, stirring was performed for 30 minutes so that the blade tip speed of the stirring blade was 8.2 m / s, and a redispersed slurry was obtained.
Next, the redispersed slurry was dehydrated and rinsed in the same manner as in the dedispersing medium step. At this time, the water used for rinsing was set to 3 times the amount of solid content of the redispersed slurry (in terms of mass).
This operation was performed a total of 3 times to obtain a washed wet cake of coalesced particles. In addition, the water used for the last simple washing | cleaning was made into 6 times amount (mass conversion) of solid content of a re-dispersion slurry. The moisture content of the wet cake was 35% by mass.
In addition, the ratio d / D between the inner diameter D (cm) of the stirring vessel used this time and the blade diameter d (cm) of the stirring blade is 0.37, and the stirring energy per liter of the mixture is 0.25 (Wh / L).

(Drying process)
Then, toner mother particles were obtained by drying the wet cake for 24 hours at 25 ° C. (room temperature) using a vacuum dryer. The obtained toner base particles were confirmed to have a core region containing a resin component and a colorant and a shell region containing no colorant. The 50% volume particle size of the toner base particles was Dv 2.98 μm, and the ratio Dv / Dn of Dv to 50% number particle size Dn was 1.06. The average circularity R of the toner base particles was 0.985.

(External addition process)
1.0 part by mass of silica having a large particle size (RX50 manufactured by Nippon Aerosil Co., Ltd.) and silica having a small particle size (RX200 manufactured by Nippon Aerosil Co., Ltd.) as an external additive with respect to 100 parts by mass of toner base particles. 0 parts by mass and 0.5 parts by mass of titanium oxide (STT30S manufactured by Titanium Industry Co., Ltd.) were added. The toner base particles were put into a 10 L Henschel mixer (manufactured by Mitsui Mining Co., Ltd.) and mixed at a blade tip peripheral speed of 30 m / s for 2 minutes to obtain a toner.

(Examples 3 to 6)
A toner was manufactured in the same manner as in Example 2 except that the adjustment conditions of the wax master were changed as shown in Table 1.

(Comparative Examples 1-4)
A toner was manufactured in the same manner as in Example 2 except that the adjustment conditions of the wax master were changed as shown in Table 1.

  Table 2 shows the evaluation results of the toner base particles obtained in Examples 1 to 6 and Comparative Examples 1 to 4. The measuring method of each physical property shown in Table 2 is as follows.

(Volume average particle size)
A 50% volume average diameter was determined using a 100 micron aperture tube of Coulter Multisizer II (Coulter Beckman).

(Wax inclusion by optical microscope observation)
The sample in which the toner base particles were suspended in water was observed with an optical microscope. The case where the wax was encapsulated in the toner base particles is indicated by ○, the case where the wax is slightly exposed on the surface of the toner base particles is indicated by △, and the case where the wax is clearly exposed on the surface of the toner base particles is indicated by ×. Show.

(Wax inclusion by total reflection FT-IR method)
5 g of toner was pressed for 1 minute at a load of 9 t with a 50-ton press (manufactured by Shimadzu Corporation) to produce 50 mmφ (2.5 mm thick) pellets. The pellet surface was measured by FTIR600Plus, IRT-30 (microscopic FT-IR manufactured by JASCO Corporation) (using absorbance Abs). The objective used was ATR-30-G45, and measurement was performed with a germanium crystal having a diameter of 100 μm. At this time, the incident angle was 45 °, and the number of integrations was auto (the number of integrations was 95 to 97). The intensity of the obtained wax-derived peak (2859 cm ⁻¹ ) was defined as the relative amount of wax near the toner surface. Further, in order to confirm the presence state of the wax in the toner, observation with a transmission electron microscope has confirmed that there is a correlation between the state dispersed near the toner surface and the peak intensity derived from the wax. From this result, it can be said that when the peak value derived from the wax is 7 or more, the exposure of the wax from the toner surface is large, and when it is 5 or less, the exposure from the toner surface is small.
(Durable printing performance)
A durability printing test was conducted using a color laser printer LP-9000 (manufactured by Seiko Epson Corporation). It is indicated by ○ when the number of successfully printed sheets is 5000 or more, Δ when 2000 or more and less than 5000 sheets (practical lower limit), and x when 1000 sheets or less (unusable).

  The toner particles obtained in Examples 1 to 6 which are the production method of the present invention have high durability printing performance because wax is included in the toner particles. On the other hand, Comparative Example 1 in which the specific energy amount when the binder resin, the organic solvent, and the wax emulsion are stirred is too small, and the methyl ethyl ketone concentration is too high when the binder resin, the organic solvent, and the wax emulsion are stirred. In Comparative Example 3, the wax concentration when the binder resin, the organic solvent, and the wax emulsion are stirred is too high. In Comparative Example 4, the temperature when the binder resin, the organic solvent, and the wax emulsion is stirred is too high. The toner particles have low wax inclusion properties and low durable printing performance.

Claims (6)

A wax master solution prepared from a binder resin, an organic solvent and a wax emulsion, and a step of obtaining a colored resin solution by dissolving or dispersing the binder resin and a colorant in the organic solvent;
A step of sequentially adding a basic compound and water to the colored resin solution to emulsify the colored resin solution in an aqueous medium;
A step of forming particles by adding an aqueous electrolyte solution to the prepared emulsified suspension and generating dispersoids in the emulsified suspension to produce colored resin fine particles;
A method for producing a toner for developing an electrostatic charge image having a volume average particle diameter of 5 to 8 μm, wherein the organic solvent is removed under reduced pressure, and then the colored resin fine particles are separated from an aqueous medium, washed and dried. 2. The electrostatic charge image development according to claim 1, wherein methyl ethyl ketone is contained in the range of 22% by mass to 51% by mass in the medium of the wax master solution, and wax is contained in the range of 9% by mass to 15% by mass in the wax master solution. Of manufacturing toner. The binder resin, organic solvent and wax emulsion were stirred under conditions of a product temperature of 35 ° C. or lower, a specific energy amount of 0.5 to 3.0 kWh / kg, and a residence time of 15 minutes or more. A step of preparing a wax master solution which is contained in a range of from mass% to 51% by mass and wherein the wax is contained in a wax master solution in a range of from 9% to 15% by mass;
A step of obtaining a colored resin solution by dissolving or dispersing the wax master solution, the binder resin and the colorant in an organic solvent;
A step of sequentially adding a basic compound and water to the colored resin solution to emulsify the colored resin solution in an aqueous medium;
A step of forming particles by adding an aqueous electrolyte solution to the prepared emulsified suspension and generating dispersoids in the emulsified suspension to produce colored resin fine particles;
A method for producing a toner for developing an electrostatic charge image having a volume average particle size of 1.5 to 4 μm, wherein the organic solvent is removed under reduced pressure, and then the colored resin fine particles are separated from the aqueous medium, washed and dried. . The toner for electrostatic image development according to any one of claims 1 to 3, wherein a wax master solution is prepared by finely dispersing a wax emulsion in a resin solution obtained by dissolving a binder resin in an organic solvent. Method. The method for producing a toner for developing an electrostatic charge image according to any one of claims 1 to 4, wherein a wax emulsion is finely dispersed in a resin solution by a bead mill. 6. The method for producing a toner for developing an electrostatic charge image according to claim 1, wherein the binder resin is a polyester resin.