JP5521960B2 - Release agent dispersion and method for producing the same, and toner for image formation and method for producing the same - Google Patents

Description

  The present invention relates to a release agent dispersion that is preferably used in the production of an image forming toner and a method for producing the same, and an image forming toner that uses the release agent dispersion and a method for producing the same.

  In general, an electrophotographic image forming method generally uses a developer to develop an electrostatic image formed on a photoreceptor prepared using a photoconductive substance using various means. In this method, the developed image is transferred to paper or the like as necessary, and fixed by heating, pressing, solvent vapor, or the like.

  The electrostatic image developing method is roughly classified into a liquid developing method using a liquid developer in which various pigments and dyes are dispersed in an insulating organic liquid, a cascade method, a magnetic brush method, and a powder cloud method. As described above, there is a dry development method using a dry developer in which a colorant such as carbon black is dispersed in a natural or synthetic resin (hereinafter sometimes referred to as “toner”). Is widely used.

  In recent years, heat fixing has become the mainstream in the process of fixing toner to a paper medium because of its high efficiency. In the case of heat fixing, conventionally, oil is applied to the fixing surface in order to suppress the adhesion between the fixing roller and the toner, but in recent years, toner containing a release agent is mainly used in the toner.

The method for producing the toner is roughly classified into a pulverization method and a polymerization method.
Since the pulverization method must be capable of being pulverized and classified using an apparatus that can be used economically, the composition obtained by melt mixing must be sufficiently brittle, There are limitations on the toner material, the particle size distribution tends to be wide when the resulting composition is pulverized, and a fine powder with a particle size of 4 μm or less and 15 μm to reduce the weight average particle size of the toner When the above coarse powder is removed by classification, the toner yield decreases, and it is difficult to uniformly disperse the colorant, charge control agent, etc. in the thermoplastic resin. It has been a problem in that it adversely affects performance, durability, image quality, and the like.
Therefore, in order to overcome the problems in the pulverization method, a method of producing a toner by a polymerization method such as a suspension polymerization method or an emulsion polymerization aggregation method (see Patent Document 1), a toner composed of a polyester resin is organically treated in water. There are disclosed a method for producing a toner that spheroidizes using a solvent (see Patent Document 2), a method for producing a toner in which a prepolymer having an isocyanate group and amines are reacted (see Patent Document 3), and the like.

As a method for producing a release agent used in the polymerization method, for example, dispersion by a wet pulverization method using a medium is known.
However, the wet pulverization method requires a long time to obtain a desired particle size distribution because a significant reduction in pulverization efficiency occurs when the particle size is below a certain particle size. Is unsuitable for pulverization and dispersion of low melting point release agents, easily forms irregular shapes due to the crystal structure of the release agent, instability in emulsification, and collisions between media. This is a problem in that, for example, the toner is scraped and mixed as an impurity in the release agent dispersion liquid, the chargeability as a toner is lowered.

As a technique for overcoming the problems in the wet pulverization method, there is a spray granulation method.
The spray granulation method is known as a toner production technique, and is a method of obtaining toner particles by spraying and granulating a melt-kneaded material composed of a toner constituent material such as a resin and a release agent with a high-pressure gas. When toner particles obtained by the spray granulation method are used, better image quality can be obtained as compared with the conventional pulverization method.
Regarding the spray granulation method, granulation based on a plurality of apparatus configurations and manufacturing conditions has been proposed. For example, a method has been proposed in which a supercritical fluid is injected into a heated and melted kneaded material, dispersed, and spray-granulated from a nozzle to rapidly expand (see Patent Document 4).

  However, the rapid expansion method has a problem that productivity is generally low. That is, in the rapid expansion method, the amount of toner fine particles generated per unit supercritical fluid and subcritical fluid weight is limited to be less than the solubility of toner in the supercritical fluid and subcritical fluid. Since critical fluids and subcritical fluids have low density and poor solubility, most high-boiling substances that are solid at room temperature (25 ° C.) have low solubility in supercritical fluids and subcritical fluids. Therefore, the toner-based production amount necessary to ensure the desired dispersion production amount, that is, the weight flow rate of the supercritical fluid and subcritical fluid capable of realizing the toner processing amount per unit time becomes very large, Considering circulation recycling of supercritical fluids and subcritical fluids, which requires large production facilities, it is a problem in terms of inefficiency due to enormous energy consumption.

  Further, the spray granulation method focuses on only the ejection of the kneaded product and injects the supercritical fluid into the kneaded product, so the volume fraction occupied by the supercritical fluid in the kneaded product is low, and when sprayed from the nozzle This was a problem in that the kneaded product was insufficiently cut and separated to easily generate coarse particles, and the particle concentration was high, so that the particles were likely to agglomerate with each other and there were very few submicron-order particles. In addition, since coarse particles are likely to be generated, there is a problem in that the nozzles are likely to be clogged because the mixed substances are blocked in the flow path in the nozzle.

Therefore, a method has been proposed in which when a kneaded product is ejected from a nozzle, a certain amount of gas collides from the periphery of the flow path before being projected from the nozzle (see Patent Document 5). According to this method, nozzle blockage can be prevented.
However, even with this method, it is difficult to granulate particles on the order of submicrons, and this method is not suitable for granulating a release agent that requires a particle size on the order of submicrons.

  Therefore, a mold release agent that can efficiently produce a mold release dispersion containing impurities with a small particle size on the order of submicron and uniform, and free from impurities in both productivity and production energy. Manufacturing method of dispersion liquid, submicron order small particle size and uniform release agent dispersion liquid obtained by the method of manufacturing release agent dispersion liquid, and manufacturing of image forming toner using the release agent dispersion liquid Manufactured by the above-described method and the above-described image forming toner manufacturing method, excellent in heat-resistant storage stability, good chargeability, and capable of obtaining a good image over a long period of time without being fused to the photoreceptor during image formation. At present, there is a demand for providing a toner for forming an image.

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, the present invention can efficiently produce a release dispersion containing impurities with a small particle size and uniform particle size on the order of submicron and free of impurities in both productivity and production energy. A mold release agent dispersion that can be obtained, a submicron order small particle size and uniform mold release agent dispersion obtained by the process for producing a mold release agent dispersion, and image formation using the mold release agent dispersion Manufactured by the above toner forming method and the above image forming toner manufacturing method, excellent in heat-resistant storage stability, good chargeability, and good image for a long time without fusing to a photoreceptor during image formation. An object of the present invention is to provide an image forming toner capable of obtaining the above.

  In order to solve the above-mentioned problems, the present inventors have made extensive studies and as a result, obtained the following findings. That is, a mixture preparation step of preparing a mixture containing 80% to 99% by volume of the supercritical fluid or subcritical fluid by mixing a supercritical fluid or subcritical fluid with the molten release agent; and the mixture A step of granulating the release agent to form release agent fine particles, and collecting the release agent fine particles in a liquid solvent to release the release agent fine particles. A release agent dispersion preparation method comprising a release agent dispersion preparation step for preparing a dispersion, and a method for producing a release agent dispersion that is efficient in terms of both productivity and production energy, with a small particle size and uniform release agent on the order of submicrons It has been found that a release dispersion containing fine particles and free of impurities can be produced in a short time, and the present invention has been completed.

The present invention is based on the above findings by the present inventors, and means for solving the above problems are as follows. That is,
<1> a mixture preparation step of preparing a mixture containing 80% by volume to 99% by volume of the supercritical fluid or subcritical fluid by mixing a supercritical fluid or subcritical fluid with a molten release agent;
A release agent fine particle granulating step of spraying the mixture to rapidly expand, granulating the release agent to form release agent fine particles;
And a release agent dispersion preparation step of preparing a release agent dispersion by collecting the release agent fine particles in a liquid solvent.
<2> The method for producing a release agent dispersion according to <1>, wherein the temperature of the mixture is not lower than the melting temperature of the release agent and not higher than 200 ° C.
<3> The method for producing a release agent dispersion according to any one of <1> to <2>, wherein the pressure of the mixture is 5 MPa to 100 MPa.
<4> The method for producing a release agent dispersion according to any one of <1> to <3>, wherein the supercritical fluid or subcritical fluid contains at least carbon dioxide.
<5> The method for producing a release agent dispersion according to any one of <1> to <4>, wherein the liquid solvent contains at least a release agent dispersant.
<6> The release agent according to any one of <1> to <5>, wherein the release agent is at least one selected from paraffin wax, microcrystalline wax, ester wax, carnauba wax, and rice wax. It is a manufacturing method of a dispersion liquid.
<7> The method for producing a release agent dispersion according to any one of <1> to <6>, wherein the solubility parameter (SP value) of the liquid solvent is 7 to 11.
<8> Obtained by the method for producing a release agent dispersion according to any one of <1> to <7>, wherein a median diameter in a volume-based particle size distribution of the release agent fine particles is 0.2 μm to 3.0 μm. The release agent dispersion is characterized in that the release frequency of the release agent fine particles of at least 5.0 μm is 5.0% or less.
<9> A method for producing an image forming toner, wherein the release agent dispersion liquid according to <8> is used.
<10> A solution preparation step of preparing a solution obtained by dissolving the release agent dispersion liquid described in <8> in a toner material solution, and dispersing the solution obtained in the solution preparation step in an aqueous medium And a toner particle granulating step for granulating toner particles. The method for producing an image forming toner according to <9>.
<11> The solution preparation step includes a releasing agent dispersion, a compound having an active hydrogen group, a polymer having a site capable of reacting with the compound having an active hydrogen group, and a binder resin in an organic solvent. And a coloring agent is dispersed, and the toner particle granulation step is in the process of reacting the compound having the active hydrogen group and the polymer having a site capable of reacting with the compound having the active hydrogen group, or The method for producing an image forming toner according to <10>, wherein the organic solvent is removed after the reaction.
<12> The method for producing an image forming toner according to any one of <10> to <11>, obtained by aggregating resin fine particles in an aqueous medium.
<13> The method for producing an image forming toner according to any one of <11> to <12>, wherein the binder resin is a polyester resin.
<14> The method for producing an image forming toner according to <13>, wherein the polyester resin has a glass transition temperature (Tg) of 30 ° C to 70 ° C.
<15> An image forming toner obtained by the method for producing an image forming toner according to any one of <9> to <14>.
<16> The image forming toner according to <15>, wherein the weight average particle diameter is 3 μm to 15 μm.
<17> The image formation according to any one of <15> to <16>, wherein a ratio (Dv / Dn) of the weight average particle diameter (Dv) to the number average particle diameter (Dn) is 1.25 or less. Toner.

  According to the present invention, it is possible to solve the above-mentioned problems and achieve the above-mentioned object, and to efficiently release particles having a small particle size and uniform on the order of submicron, both in terms of productivity and production energy. A release agent dispersion manufacturing method capable of producing a release dispersion containing impurities in a short time, a submicron order small particle size and uniform obtained by the release agent dispersion manufacturing method Produced by a mold release agent dispersion, a method for producing an image forming toner using the mold release agent dispersion, and a method for producing the image formation toner, and having excellent heat-resistant storage stability and good chargeability, It is possible to provide an image forming toner capable of obtaining a good image over a long period of time without being fused to the photoreceptor during image formation.

FIG. 1 is a diagram showing an example of an apparatus used in the method for producing a release agent dispersion of the present invention.

(Method for producing release agent dispersion)
The method for producing a release agent dispersion of the present invention includes at least a mixture preparation step, a release agent fine particle granulation step, and a release agent dispersion preparation step, and further includes other steps as necessary. .

<Mixture preparation process>
The said mixture preparation process is a process of mixing a supercritical fluid thru | or a subcritical fluid (phase) with the molten mold release agent (phase).

<< Mixture >>
The mixture includes at least a molten release agent and a supercritical fluid or a subcritical fluid, and further includes other components as necessary.

-Release agent-
There is no restriction | limiting in particular as said mold release agent, According to the objective, it can select suitably, For example, waxes etc. are mentioned.
The waxes are not particularly limited and can be appropriately selected according to the purpose. For example, low molecular weight polyolefin wax, synthetic hydrocarbon wax, natural wax, petroleum wax, higher fatty acid and metal salt thereof, Examples thereof include higher fatty acid amides and modified waxes obtained by modifying these various waxes. These may be used individually by 1 type and may use 2 or more types together.

There is no restriction | limiting in particular as said low molecular weight polyolefin wax, According to the objective, it can select suitably, For example, a low molecular weight polyethylene wax, a low molecular weight polypropylene wax, etc. are mentioned.
The synthetic hydrocarbon wax is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include Fischer-Tropsch wax.
The natural wax is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include beeswax, carnauba wax, candelilla wax, rice wax, and montan wax.
There is no restriction | limiting in particular as said petroleum wax, According to the objective, it can select suitably, For example, paraffin wax, microcrystalline wax, etc. are mentioned.
There is no restriction | limiting in particular as said higher fatty acid, According to the objective, it can select suitably, For example, a stearic acid, a palmitic acid, myristic acid etc. are mentioned.
Among these, paraffin wax, microcrystalline wax, ester wax, carnauba wax and rice wax are preferable, and carnauba wax and paraffin wax are particularly preferable.

  There is no restriction | limiting in particular as melting | fusing point of the said mold release agent, Although it can select suitably according to the objective, 40 to 160 degreeC is preferable, 50 to 120 degreeC is more preferable, and 60 to 90 degreeC is especially preferable. . If the melting point is less than 40 ° C., the wax may adversely affect the heat-resistant storage stability. If the melting point exceeds 160 ° C., it may easily cause a cold offset when fixing at a low temperature. May occur.

  There is no restriction | limiting in particular as content in the said mold release agent dispersion liquid of the said mold release agent, Although it can select suitably according to the objective, 1 mass part-15 mass parts are preferable, and 2 mass parts-10 mass parts are preferable. Is more preferable. When the content exceeds 15 parts by mass, the release agent fine particles may aggregate to cause deterioration of toner granulation property and heat resistant storage stability.

-Supercritical fluid or subcritical fluid-
The supercritical fluid exists as a non-condensable high-density fluid at a temperature or pressure range that exceeds the limit (critical point) where gas and liquid can coexist, does not cause condensation even when compressed, and exceeds the critical temperature. And it is a fluid in the state more than a critical pressure.
The subcritical fluid is a fluid that exists as a high-pressure liquid in a temperature or pressure region near the critical point.
The critical point temperature (critical temperature) is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably lower from the viewpoint of energy consumption and the like.

These supercritical fluids or subcritical fluids are not particularly limited and can be appropriately selected according to the purpose. For example, carbon monoxide, carbon dioxide, ammonia, nitrogen, water, methanol, ethanol, ethane, propane 2,3-dimethylbutane, benzene, chlorotrifluoromethane, dimethyl ether and the like. These may be used alone or in combination of two or more.
Among these, carbon dioxide is particularly preferable in that it has a low critical temperature of about 31.3 ° C., becomes a supercritical fluid or subcritical fluid under mild conditions, has excellent handling properties, is nonpolar, harmless, and inexpensive. preferable. Carbon dioxide is also preferable in that it has a high affinity with organic substances, so that the amount dissolved in the melted release agent is high, and a high shear effect is obtained in the release agent fine particle granulation step described later. Further, when the supercritical fluid or subcritical fluid is carbon dioxide, the median diameter of the release agent fine particles is reduced, the toner surface exposure amount of the release agent is reduced, and the photoreceptor is not contaminated, and the fixing property is improved. In addition, when it is used for a chemical toner, the granulation behavior is stable.

The ratio of the supercritical fluid to subcritical fluid in the mixture is 80% to 99% by volume, preferably 85% to 98% by volume. When the ratio is less than 80% by volume, the release agent particles may be coarsened, and when it exceeds 99% by volume, the production energy efficiency is significantly deteriorated.
On the other hand, by setting the ratio to 80% by volume to 99% by volume, it is possible to form a state in which the release agent is suspended as droplets in the mixture. It is preferable in that the release agent is uniformly and efficiently sheared during rapid expansion, and reaggregation between release agent particles can be suppressed.
The ratio of the supercritical fluid or subcritical fluid in the mixture can be adjusted by, for example, the flow rate when the supercritical fluid or subcritical fluid is mixed with the molten release agent.

<< Method for Preparing Mixture >>
The method for preparing the mixture is not particularly limited and may be appropriately selected depending on the intended purpose. For example, after the mold release agent is placed in a heatable pressure-resistant container and melted, it is under pressure. Examples thereof include a method of mixing the supercritical fluid or subcritical fluid into the molten release agent.

  The state of the mixture is not particularly limited and may be appropriately selected depending on the intended purpose. However, before being used in the release agent fine particle granulation step described later, the release agent (phase) is formed into droplets. A state of being suspended (dispersed) in the supercritical fluid or subcritical fluid (phase) is particularly preferable. When the release agent is not suspended, the shearing effect on the release agent at the time of rapid expansion in the release agent fine particle granulation step to be described later is not uniform, and the particle size distribution of the release agent dispersion becomes wide. There is.

The temperature of the mixture is not particularly limited as long as it is equal to or higher than the critical temperature of the supercritical fluid or subcritical fluid to be used, and can be selected according to the purpose.
There is no restriction | limiting in particular as an upper limit of the said critical temperature, Although it can select suitably according to the kind etc. of mold release agent, 200 degrees C or less is preferable and 180 degrees C or less is more preferable. When the melting point exceeds 200 ° C., the release agent may be thermally decomposed.
Further, the lower limit of the critical temperature is not particularly limited and can be appropriately selected according to the type of the release agent, but the other fluid that can be added to the supercritical fluid or subcritical fluid is The temperature that can exist as a gas is preferable, and the melting temperature of the release agent or higher is more preferable. If the melting point is lower than the melting temperature of the release agent, since the release agent is solid, spray granulation may not be possible in the release agent fine particle granulation step described later.
The temperature of the mixture is substantially the same as the set temperature of the atmosphere in which the melted release agent and the supercritical fluid or subcritical fluid are mixed.

The pressure of the mixture is not particularly limited as long as it is equal to or higher than the critical pressure of the supercritical fluid or subcritical fluid to be used, and can be appropriately selected according to the purpose, but is preferably 5 MPa to 100 MPa, 60 MPa is more preferable.
When the pressure is less than 5 MPa, the amount of carbon dioxide dissolved in the release agent melt is small, and the pressure is low. In some cases, the amount of particles increases, and when the pressure exceeds 100 MPa, the equipment becomes expensive and the energy efficiency during production may deteriorate.
The pressure of the mixture is substantially the same temperature as the set pressure of the atmosphere in which the melted release agent and the supercritical fluid or subcritical fluid are mixed.

  The time for mixing the molten release agent and the supercritical fluid or subcritical fluid is not particularly limited and may be appropriately selected according to the purpose.

  The flow rate for mixing the supercritical fluid or subcritical fluid in the molten release agent is not particularly limited and may be appropriately selected depending on the intended purpose, but is 10 L / min to 1,000 L / min. Is preferable, and 50 L / min to 500 L / min is more preferable.

<Particle release agent granulation process>
The release agent fine particle granulating step is a step of spraying the mixture to rapidly expand, and granulating the release agent to form release agent fine particles.
The release agent fine particle granulation step preferably uses a PGSS (Particles from Gas Saturated) method. By spraying the mixture maintained at a high pressure in the mixture preparation step onto a region where the high pressure state cannot be maintained. The release agent when the pressure of the mixture changes rapidly and the supercritical fluid or subcritical fluid dissolved in the release agent, or the supercritical fluid or subcritical fluid outside the release agent is rapidly expanded. Is sheared and fine particles are granulated.
Therefore, in the release agent fine particle granulating step, the pressure, temperature, and the like at which the mixture is sprayed are substantially the same as the pressure, temperature, and the like of the mixture.

<< Spray granulation method >>
The method for spray granulating the mold release agent is not particularly limited as long as it can be rapidly expanded and the mold release agent can be granulated, and can be appropriately selected according to the purpose. The method of spraying to the area | region which cannot maintain a high pressure state etc. is mentioned.
Here, the region where the high pressure state cannot be maintained means normal pressure, and preferably 0.1 MPa or less.

<Partner preparation process>
The releasing agent dispersion preparing step is a step of collecting the releasing agent fine particles in a liquid solvent to prepare a releasing agent dispersion.

<< Liquid solvent >>
The liquid solvent is not particularly limited as long as the release agent can be dispersed, and can be appropriately selected according to the purpose. For example, methanol, isopropanol, ethylene glycol, dimethylformamide, tetrahydrofuran, cellosolves , Lower ketones, or aqueous liquid solvents such as mixed solvents thereof; toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, Examples include dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, acetone, tetrahydrofuran, methanol, ethanol, isopropanol, ethylene glycol, and other organic solvents. These may be used alone or in combination of two or more.
Among these, the liquid solvent preferably has a solubility parameter (SP value) of 7 to 11, preferably 7.5 to 10 when the releasing agent dispersion is used in a toner production method. More preferably.
Specific examples of the liquid solvent having the SP value of 7 to 11 include ethyl acetate (SP value: 9.1), toluene (SP value: 8.9), xylene (SP value: 8.8), benzene ( SP value: 9.2), methylene chloride (SP value: 9.7), 1,2-dichloroethane (SP value: 9.8), chloroform (SP value: 9.3), carbon tetrachloride (SP value: 8.6) is particularly preferable.
The SP value can be calculated by, for example, a known Fedors method.

  There is no restriction | limiting in particular as usage-amount of the said liquid solvent, Although it can select suitably according to the objective, 100 mass parts-10,000 mass parts are preferable with respect to 100 mass parts of said mold release agents, 300 masses Parts to 5,000 parts by mass are more preferable, and 800 parts to 2,000 parts by mass are particularly preferable. If the amount of the liquid solvent used is less than 100 parts by mass, the collection of the release agent may be insufficient and the recovery rate may be reduced. If the amount exceeds 10,000 parts by mass, the collection tank volume is large. Energy efficiency may be reduced.

  The temperature of the liquid solvent is not particularly limited and may be appropriately selected depending on the intended purpose. It is preferably not less than the melting point of the liquid solvent, not more than the boiling point of the liquid solvent and not more than the melting point of the release agent, and 20 ° C. ~ 100 ° C is more preferable, and 20 ° C to 60 ° C is particularly preferable. When the temperature of the liquid solvent is less than 20 ° C., the spray nozzle may be clogged. When the temperature exceeds 100 ° C., the liquid solvent may volatilize or cause release agent particles to aggregate. There is.

-Release agent dispersant-
It is preferable that the liquid solvent further contains a release agent dispersant.
The release agent dispersant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a unit that is highly compatible with the release agent and a unit that is highly compatible with the liquid solvent are block bodies. Diblock copolymers or graft copolymers present as oligomers and oligomers thereof, or unsaturated hydrocarbons such as ethylene, propylene, butene, styrene, α-styrene, and acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid And α, β-unsaturated carboxylic acids such as itaconic anhydride, copolymers thereof or their anhydrides, vinyl resin-polyester blocks, or grafts. These may be used alone or in combination of two or more.

  The unit having high compatibility with the release agent is not particularly limited and may be appropriately selected depending on the purpose. For example, a long-chain alkyl group having 12 or more carbon atoms, polyethylene, polypropylene, polybutene, polybutadiene, Or the copolymer etc. are mentioned.

  The unit having high compatibility with the liquid solvent is not particularly limited and may be appropriately selected depending on the purpose. For example, a copolymer with acrylic acid, methacrylic acid, maleic acid, an ester thereof or an anhydride thereof And polyester.

There is no restriction | limiting in particular as a density | concentration of the said mold release agent dispersing agent in the said liquid solvent, Although it can select suitably according to the objective, 50 mass% or less is preferable and 30 mass% or less is more preferable. When the dispersant concentration exceeds 50% by mass, the viscosity of the liquid solvent increases, resulting in a decrease in fluidity, which facilitates coalescence and / or aggregation of release agent fine particles and widens the particle size distribution. is there.
The particle size of the release agent fine particles can be controlled by changing the concentration of the release agent dispersant.

<< Method for Preparing Release Agent Dispersion >>
In the release agent dispersion preparation step, the method for preparing the release agent fine particles is not particularly limited and can be appropriately selected according to the purpose. For example, in the release agent fine particle granulation step, For example, a method of collecting the sprayed release agent fine particles in the liquid solvent at the same time as spraying the mixture onto a region where a high pressure state cannot be maintained.

  The method for producing the release agent dispersion is not particularly limited as long as it includes the mixture preparation step, the release agent fine particle granulation step, and the release agent dispersion preparation step, and may be appropriately selected according to the purpose. For example, you may manufacture using a well-known apparatus.

  Hereinafter, an example of a method for producing the release agent dispersion using the apparatus will be described with reference to the drawings, but the production method of the present invention is not limited thereto.

FIG. 1 is a diagram showing an example of an apparatus used in the method for producing the release agent dispersion.
The apparatus includes a release agent melting phase 1 for melting a release agent, a liquid delivery device 2 for feeding a melted release agent, a liquid delivery device 3 for feeding a supercritical fluid or a subcritical fluid, A mixing unit 4 that forms a mixture of the release agent and the supercritical fluid or subcritical fluid, a high-pressure nozzle 5 that sprays the mixture of the release agent and the supercritical fluid or subcritical fluid, and a liquid solvent 6 are accommodated. And a chamber 7.
A supercritical fluid or a subcritical fluid, which is supplied with the release agent into the release agent melt phase 1 and melted, and the release agent melted by the liquid delivery device 2 is fed and fed by the liquid delivery device 3. A chamber containing a liquid solvent 6 from a high-pressure nozzle 5 after contacting the molten release agent and mixing the release agent and supercritical fluid or subcritical fluid in the mixing unit 4 to prepare a mixture. 7 Spray inside. Since the inside of the chamber 7 is at a normal pressure, when the mixture is sprayed from the high-pressure nozzle 5 when the mixture is discharged, the mixture rapidly expands to generate release agent fine particles. The release agent fine particles are diffused in the liquid solvent 6 in the chamber 7 to produce a release agent dispersion.

According to the method for producing a release agent dispersion of the present invention, the molten release agent and the supercritical fluid or subcritical fluid are mixed without dissolving the entire release agent in the supercritical fluid or subcritical fluid. By spray granulating the mixture, it is advantageous in that a release agent dispersion can be produced efficiently and in a short time in both productivity and production energy.
Further, it is advantageous in that it is possible to granulate release agent fine particles having a small particle size on the order of submicron, which is impossible with the conventional method proposed for granulating toner.

(Release agent dispersion)
The release agent dispersion in the present invention contains at least release agent fine particles and a liquid solvent, and further contains other components as necessary.
The release agent dispersion of the present invention is obtained by the method for producing a release agent dispersion, and the release agent fine particles and the liquid solvent contained in the release agent dispersion are as described above.

As the particle diameter of the release agent fine particles in the release agent dispersion, the median diameter in the volume-based particle size distribution is 0.2 μm to 3 μm, preferably 0.2 μm to 1 μm, preferably 0.2 μm to 0 μm. More preferably, it is 6 μm. When the median diameter is less than 0.2 μm, the occurrence of cold offset or winding around the roller may occur. When the median diameter exceeds 3.0 μm, the toner surface exposure amount of the release agent increases and the photosensitive member. When used in chemical toners, it may cause problems such as contamination of the toner, deterioration of fixability, deterioration of heat storage stability, and instability of granulation behavior.
The median diameter can be measured by, for example, a laser scattering particle size measuring device (for example, LA-920: Horiba, Ltd.).

Here, a particle having a particle size of 5.0 μm or more in the volumetric particle size distribution is referred to as coarse particles.
The ratio of the coarse particles of the release agent fine particles in the release agent dispersion is not particularly limited and may be appropriately selected depending on the intended purpose. The integration frequency is preferably 5.0% or less, and more preferably 1% or less. When the ratio of the coarse particles exceeds 5.0%, the toner surface exposure amount of the release agent increases, so that the toner is contaminated, the fixing property is deteriorated, the heat resistant storage property is deteriorated, and the toner is used for a chemical toner. May cause problems such as coarsening.

  The release agent dispersion is preferably used in a method for producing an image forming toner because the release agent contained in the release agent dispersion has a small particle size and uniform on the order of submicrons.

(Method for producing image-forming toner)
The method for producing the image forming toner of the present invention is not particularly limited as long as the release agent dispersion of the present invention is used, and can be appropriately selected according to the purpose. Examples thereof include a turbid polymerization method, a dispersion polymerization method, an emulsion aggregation method, a polymer solution suspension method, and a polymer elongation method.
Among these, a method of obtaining toner particles by suspending a polymer solution in an aqueous medium to obtain toner particles is preferred, and a method of obtaining toner particles by a polymer stretching method and a polymer stretching method are particularly preferred.

  The method of suspending the polymer solution in an aqueous medium to obtain toner particles includes, for example, a solution preparation step and a toner particle granulation step, and if necessary, a synthesis step of an active hydrogen group-containing compound. And a synthesis step of a polymer (prepolymer) capable of reacting with the active hydrogen group-containing compound.

<Dissolution preparation process>
The solution preparation step is a step of preparing a solution obtained by dissolving the release agent dispersion in a toner material solution.

<< Toner Material Solution >>
As the toner material solution (oil phase), at least the release agent dispersion of the present invention is contained in an organic solvent, and if necessary, a compound having an active hydrogen group and a compound having the active hydrogen group And other components such as a polymer having a site capable of reacting with the binder, a binder resin, a colorant, a charge control agent, polymer polymer particles, a fluidity improver, a cleaning property improver, and a magnetic material.

-Organic solvent-
The organic solvent is not particularly limited as long as it is a solvent that can dissolve or disperse the image forming toner raw material, and can be appropriately selected according to the purpose. Of volatile compounds such as toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, Examples include ethyl acetate, methyl ethyl ketone, and methyl isobutyl ketone. These may be used individually by 1 type and may use 2 or more types together.
Among these, the organic solvent is particularly preferably ethyl acetate, toluene, xylene, benzene, methylene chloride, 1,2-dichloroethane, chloroform, carbon tetrachloride, and the like.

  There is no restriction | limiting in particular as the usage-amount of the said organic solvent, Although it can select suitably according to the objective, 40 mass parts-300 mass parts are preferable with respect to 100 mass parts of said toner materials for image formation, 60 masses. Part to 140 parts by weight is more preferable, and 80 parts to 120 parts by weight is particularly preferable.

-Release agent dispersion-
The content of the release agent dispersion in the image forming toner is not particularly limited and may be appropriately selected depending on the intended purpose. However, the release agent in the toner particles exceeds 0 part by mass. The amount is preferably less than or equal to parts by mass, more preferably 3 to 35 parts by mass. When the content exceeds 40 parts by mass, the low-temperature fixability may be impaired or the image quality may be deteriorated (glossiness is too high).

-Active hydrogen group-containing compound-
The active hydrogen group-containing compound acts as an elongation agent, a crosslinking agent, or the like when a polymer capable of reacting with the active hydrogen group-containing compound undergoes an elongation reaction, a crosslinking reaction, or the like in an aqueous medium described later.
The active hydrogen group-containing compound is not particularly limited as long as it has an active hydrogen group, and can be appropriately selected depending on the purpose. For example, the polymer capable of reacting with the active hydrogen group-containing compound is In the case of the isocyanate group-containing polyester prepolymer (A), the amines (B) can be increased in molecular weight by a reaction such as an elongation reaction or a crosslinking reaction with the isocyanate group-containing polyester prepolymer (A). Is preferred.

  There is no restriction | limiting in particular as said active hydrogen group, According to the objective, it can select suitably, For example, a hydroxyl group (alcoholic hydroxyl group or phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, alcoholic hydroxyl groups are particularly preferable.

--Isocyanate group-containing polyester prepolymer (A)-
The isocyanate group-containing polyester prepolymer (A) is not particularly limited and may be appropriately selected depending on the intended purpose. For example, it is a polycondensate of a polyol (PO) and a polycarboxylic acid (PC), And what made the said active hydrogen group containing polyester resin react with polyisocyanate (PIC) etc. are mentioned.

--- Polyol (PO) ---
There is no restriction | limiting in particular as said polyol (PO), According to the objective, it can select suitably, For example, diol (DIO), trihydric or more polyol (TO), diol (DIO), and trihydric or more polyol ( TO) and the like. These may be used individually by 1 type and may use 2 or more types together. Among these, the diol (DIO) alone or a mixture of the diol (DIO) and a small amount of the trivalent or higher polyol (TO) is preferable.

Examples of the diol (DIO) include alkylene glycols, alkylene ether glycols, alicyclic diols, alkylene oxide adducts of alicyclic diols, bisphenols, alkylene oxide adducts of bisphenols, and the like.
The alkylene glycol is preferably one having 2 to 12 carbon atoms, such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, and the like. Can be mentioned.
Examples of the alkylene ether glycol include diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene ether glycol. Examples of the alicyclic diol include 1,4-cyclohexanedimethanol and hydrogenated bisphenol A.
Examples of the alkylene oxide adduct of the alicyclic diol include those obtained by adding an alkylene oxide such as ethylene oxide, propylene oxide, butylene oxide to the alicyclic diol.
Examples of the bisphenols include bisphenol A, bisphenol F, and bisphenol S.
Examples of the alkylene oxide adduct of the bisphenol include those obtained by adding an alkylene oxide such as ethylene oxide, propylene oxide, butylene oxide to the bisphenol.
Among these, alkylene glycols having 2 to 12 carbon atoms, alkylene oxide adducts of bisphenols and the like are preferable, and alkylene oxide adducts of bisphenols, alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. Mixtures are particularly preferred.

The trihydric or higher polyol (TO) is preferably trivalent to octahydric or higher, for example, a trihydric or higher polyhydric aliphatic alcohol, a trihydric or higher polyphenol, a trihydric or higher polyphenol. And alkylene oxide adducts.
Examples of the trihydric or higher polyhydric aliphatic alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, and the like.
Examples of the trihydric or higher polyphenols include trisphenol PA, phenol novolak, cresol novolak, and the like.
Examples of the alkylene oxide adduct of trihydric or higher polyphenols include those obtained by adding an alkylene oxide such as ethylene oxide, propylene oxide, butylene oxide to the trihydric or higher polyphenols.

  As a mixing mass ratio (DIO: TO) of the diol (DIO) and the trivalent or higher polyol (TO) in the mixture of the diol (DIO) and the trivalent or higher polyol (TO), there is a particular limitation. However, 100: 0.01 to 10 is preferable, and 100: 0.01 to 1 is more preferable.

--- Polycarboxylic acid (PC) ---
There is no restriction | limiting in particular as said polycarboxylic acid (PC), Although it can select suitably according to the objective, For example, dicarboxylic acid (DIC), trivalent or more polycarboxylic acid (TC), dicarboxylic acid (DIC) ) And a tri- or higher valent polycarboxylic acid. These may be used individually by 1 type and may use 2 or more types together. Among these, dicarboxylic acid (DIC) alone or a mixture of DIC and a small amount of trivalent or higher polycarboxylic acid (TC) is preferable. Examples of the dicarboxylic acid include alkylene dicarboxylic acid, alkenylene dicarboxylic acid, and aromatic dicarboxylic acid.

The alkenylene dicarboxylic acid preferably has 4 to 20 carbon atoms, and examples thereof include succinic acid, adipic acid, sebacic acid, maleic acid, and fumaric acid.
As said aromatic dicarboxylic acid, a C8-C20 thing is preferable, For example, a phthalic acid, an isophthalic acid, a terephthalic acid, naphthalene dicarboxylic acid etc. are mentioned.
Among these, alkenylene dicarboxylic acid having 4 to 20 carbon atoms and aromatic dicarboxylic acid having 8 to 20 carbon atoms are preferable.
The trivalent or higher polycarboxylic acid (TC) is preferably 3 to 8 or higher, and examples thereof include aromatic polycarboxylic acids.
The aromatic polycarboxylic acid preferably has 9 to 20 carbon atoms, and examples thereof include trimellitic acid and pyromellitic acid.

  As the polycarboxylic acid (PC), the dicarboxylic acid (DIC), the trivalent or higher polycarboxylic acid (TC), and a mixture of the dicarboxylic acid (DIC) and the trivalent or higher polycarboxylic acid, Any acid anhydride or lower alkyl ester selected from can also be used. Examples of the lower alkyl ester include methyl ester, ethyl ester, isopropyl ester and the like.

  Mixing mass ratio (DIC: TC) of the dicorbonic acid (DIC) and the trivalent or higher polycarboxylic acid (TC) in the mixture of the dicarboxylic acid (DIC) and the trivalent or higher polycarboxylic acid (TC) There is no restriction | limiting in particular, Although it can select suitably according to the objective, 100: 0.01-10 are preferable and 100: 0.0.1-1 are more preferable.

  The mixing ratio for the polycondensation reaction between the polyol (PO) and the polycarboxylic acid (PC) is not particularly limited and may be appropriately selected depending on the intended purpose. For example, in the polyol (PO) The equivalent ratio ([OH] / [COOH]) of the hydroxyl group [OH] and the carboxyl group [COOH] in the polycarboxylic acid (PC) is usually preferably 2/1 to 1/1, and 1.5 / 1-1 / 1 is more preferable, and 1.3 / 1 to 1.02 / 1 is particularly preferable.

  There is no restriction | limiting in particular as content of the said polyol (PO) in the said isocyanate group containing polyester prepolymer (A), Although it can select suitably according to the objective, 0.5 mass%-40 mass% are preferable. 1 mass%-30 mass% are more preferable, and 2 mass%-20 mass% are especially preferable. When the content is less than 0.5% by mass, the hot offset resistance deteriorates, and it may be difficult to achieve both heat-resistant storage stability and low-temperature fixability of the image forming toner. If it exceeds 100%, the low-temperature fixability may deteriorate.

--- Polyisocyanate (PIC) ---
There is no restriction | limiting in particular as said polyisocyanate (PIC), Although it can select suitably according to the objective, For example, aliphatic polyisocyanate, alicyclic polyisocyanate, aromatic diisocyanate, araliphatic diisocyanate, isocyanurate And those blocked with phenol derivatives, oximes, caprolactams, and the like.

Examples of the aliphatic polyisocyanate include tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, trimethylhexane diisocyanate, Examples include tetramethylhexane diisocyanate.
Examples of the alicyclic polyisocyanate include isophorone diisocyanate and cyclohexylmethane diisocyanate.
Examples of the aromatic diisocyanate include tolylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, diphenylene-4,4′-diisocyanate, 4,4′-diisocyanato-3,3′-dimethyldiphenyl, 3- Examples thereof include methyldiphenylmethane-4,4′-diisocyanate and diphenyl ether-4,4′-diisocyanate.
Examples of the araliphatic diisocyanate include α, α, α ′, α′-tetramethylxylylene diisocyanate. Examples of the isocyanurates include tris-isocyanatoalkyl-isocyanurate and triisocyanatocycloalkyl-isocyanurate. These can be used alone or in combination of two or more.

  As a mixing ratio when the polyisocyanate (PIC) and the active hydrogen group-containing polyester resin (for example, a hydroxyl group-containing polyester resin) are reacted, the isocyanate group [NCO] in the polyisocyanate (PIC) and the hydroxyl group-containing component are used. The mixing equivalent ratio ([NCO] / [OH]) with the hydroxyl group [OH] in the polyester resin is usually preferably 5/1 to 1/1, more preferably 3/1 to 1.2 / 1. 5/1 to 1.1 / 1 is particularly preferred. When the isocyanate group [NCO] exceeds 5, offset resistance may deteriorate, and when it is less than 1, gelation may occur during synthesis.

  There is no restriction | limiting in particular as content in the said isocyanate group containing polyester prepolymer (A) of the said polyisocyanate (PIC), Although it can select suitably according to the objective, For example, 0.5 mass%-40 mass % Is preferable, 1% by mass to 30% by mass is more preferable, and 2% by mass to 20% by mass is still more preferable. When the content is less than 0.5% by mass, the hot offset resistance is deteriorated, and it may be difficult to achieve both heat-resistant storage stability and low-temperature fixability. When the content exceeds 40% by mass, Low temperature fixability may deteriorate.

  The average number of isocyanate groups contained per molecule of the isocyanate group-containing polyester prepolymer (A) is preferably 2 or more, more preferably 2.0 to 2.5, and particularly preferably 2.0 to 2.2. preferable. When the average number of isocyanate groups is less than 2, hot offset resistance may be deteriorated.

  There is no restriction | limiting in particular as said amine (B), According to the objective, it can select suitably, For example, diamine (B1), trivalent or more polyamine (B2), amino alcohol (B3), amino mercaptan ( Examples thereof include B4), amino acid (B5), and those obtained by blocking the amino group of (B1) to B5) (B6). These may be used individually by 1 type and may use 2 or more types together. Among these, diamine (B1), a mixture of diamine (B1) and a small amount of a trivalent or higher polyamine (B2) is particularly preferable.

There is no restriction | limiting in particular as said diamine (B1), According to the objective, it can select suitably, For example, aromatic diamine, alicyclic diamine, aliphatic diamine etc. are mentioned.
Examples of the aromatic diamine include phenylenediamine, diethyltoluenediamine, and 4,4′diaminodiphenylmethane.

Examples of the alicyclic diamine include 4,4′-diamino-3,3′dimethyldicyclohexylmethane, diaminecyclohexane, and isophoronediamine.
Examples of the aliphatic diamine include ethylene diamine, tetramethylene diamine, and hexamethylene diamine.
Examples of the trivalent or higher polyamine (B2) include diethylenetrimine and triethylenetetramine.
Examples of the amino alcohol (B3) include ethanolamine and hydroxyethylaniline.
Examples of the amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan.
Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid.
Examples of (B6) in which the amino group of (B1) to (B5) is blocked (B6) include any of the amines and ketones of (B1) to (B5) (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.) And ketimine compounds and oxazolyzone compounds obtained from the above.

  There is no restriction | limiting in particular as a mixing ratio of the said amines (B) and the said isocyanate group containing polyester prepolymer (A), Although it can select suitably according to the objective, The said isocyanate group containing prepolymer (A ) And the equivalent group ratio ([NCO] / [NHx]) of the amino group [NHx] in the amines (B) is preferably 1/3 to 3/1, 2 to 2/1 is more preferable, and 1 / 1.5 to 1.5 / 1 is particularly preferable. When the mixing equivalent ratio ([NCO] / [NHx]) is less than 1/3, the low-temperature fixability may be lowered. When the mixing equivalent ratio exceeds 3/1, the molecular weight is lowered and the hot offset resistance is reduced. May get worse.

-Polymer capable of reacting with the active hydrogen group-containing compound-
The polymer that can react with the active hydrogen group-containing compound is not particularly limited as long as it has at least a site capable of reacting with the active hydrogen group-containing compound. For example, a polyol resin, a polyacrylic resin, a polyester resin, an epoxy resin, or a derivative resin thereof can be used. These may be used individually by 1 type and may use 2 or more types together. Among these, the polymer capable of reacting with the active hydrogen group-containing compound is particularly preferably a polyester resin in terms of high fluidity and transparency at the time of melting.

  The site capable of reacting with the active hydrogen group-containing compound is not particularly limited and may be appropriately selected from known substituents. Examples thereof include an isocyanate group, an epoxy group, a carboxylic acid, and an acid chloride group. Is mentioned. These may be contained singly or in combination of two or more. Among these, an isocyanate group is particularly preferable.

There is no restriction | limiting in particular as a mass average molecular weight of the polymer which can react with the said active hydrogen group containing compound, Although it can select suitably according to the objective, 1,000 or more are preferable and 2,000-1,000. 1,000 is more preferable, and 8,000 to 100,000 is particularly preferable. When the mass average molecular weight is less than 1,000, the hot offset resistance may be deteriorated.
The molecular weight can be measured, for example, by GPC (gel permeation chromatography).

  There is no restriction | limiting in particular as glass transition temperature (Tg) of the polymer which can react with the said active hydrogen group containing compound, Although it can select suitably according to the objective, 30 to 70 degreeC is preferable, and 40 to 65 ° C. is more preferable. When the glass transition temperature (Tg) is less than 30 ° C., the heat-resistant storage stability of the image forming toner may deteriorate, and when it exceeds 70 ° C., the low-temperature fixability may not be sufficient.

-Binder resin-
There is no restriction | limiting in particular as said binder resin, According to the objective, it can select suitably, For example, a polyester resin etc. are mentioned. Among these, the binder resin is particularly preferably an unmodified polyester resin (an unmodified polyester resin). When the unmodified polyester resin is contained in the image forming toner, low-temperature fixability and glossiness can be improved.

The unmodified polyester resin is not particularly limited and may be appropriately selected from known ones according to the purpose. For example, the same polyester resin as the urea bond-forming group-containing polyester resin, that is, polyol (PO) Examples include polycondensates with polycarboxylic acids (PC).
The unmodified polyester resin is partially compatible with the urea bond-forming group-containing polyester resin (RMPE), that is, has a similar structure compatible with each other. It is preferable in terms of hot offset.

  The mass average molecular weight of the unmodified polyester resin is not particularly limited and may be appropriately selected depending on the intended purpose. It is 1,000 to 30,000 as measured by GPC (gel permeation chromatography). Preferably, 1,500 to 10,000 are more preferable, and 2,000 to 8,000 are particularly preferable. When the mass average molecular weight is less than 1,000, the heat resistant storage stability may be deteriorated, and when it exceeds 30,000, the low temperature fixability may be deteriorated.

There is no restriction | limiting in particular as a hydroxyl value of the said unmodified polyester resin, Although it can select suitably according to the objective, 5 or more are preferable, 10-120 are more preferable, and 20-80 are especially preferable. If the hydroxyl value is less than 5, it may be difficult to achieve both heat-resistant storage stability and low-temperature fixability.
The hydroxyl value can be measured based on, for example, JIS K0070.

There is no restriction | limiting in particular as an acid value of the said non-modified polyester resin, Although it can select suitably according to the objective, 1-40 are preferable and 4-30 are more preferable. In general, the image forming toner is likely to be negatively charged by having an acid value.
The acid value can be measured based on, for example, JIS K0070.
Can be measured.

  When the unmodified polyester resin is contained in the image forming toner, the mixing mass ratio between the urea bond-forming group-containing polyester resin and the unmodified polyester resin is not particularly limited and is appropriately selected depending on the purpose. 5/95 to 50/50 are preferred. When the mixing mass ratio of the unmodified polyester resin to the urea bond-forming group-containing polyester resin is more than 95, hot offset resistance is deteriorated, and it is difficult to achieve both heat-resistant storage stability and low-temperature fixability. If it is less than 50, the low-temperature fixing may be deteriorated.

There is no restriction | limiting in particular as glass transition temperature (Tg) of the said binder resin, Although it can select suitably according to the objective, 30 to 70 degreeC is preferable and 35 to 60 degreeC is more preferable. When the glass transition temperature is less than 30 ° C., the heat resistant storage stability may be deteriorated, and when it exceeds 70 ° C., the cold offset generation temperature may be increased.
The glass transition temperature can be measured with a thermal analyzer (for example, TG-DSC system TAS-100, manufactured by Rigaku Corporation).

-Colorant-
The colorant is not particularly limited and may be appropriately selected from known dyes and pigments according to the purpose. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Lead Red, Lead Red, Cadmium Red, Cad Muum Mercury Red, Antimon Zhu, Permanent Red 4R, PA Red, Faise Red, Parachlor Ortho Nitroaniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Risor Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pogment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon, Oh Lured, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), Indigo, Ultramarine Blue, Bitumen, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Oxidation Chrome, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Ash Examples include degreen lake, malachite green lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc white, and litbon. These may be used individually by 1 type and may use 2 or more types together.

  The content of the colorant in the toner particles for image formation is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1% by mass to 15% by mass, and 3% by mass to 10% by mass. Is more preferable. When the content is less than 1% by mass, the coloring power of the image forming toner is reduced. When the content exceeds 15% by mass, poor dispersion of the pigment in the image forming toner occurs, and the coloring power is reduced. It may lead to a decrease in the electrical characteristics of the image forming toner.

The colorant may be used as a master batch combined with a resin.
The masterbatch resin is not particularly limited and may be appropriately selected from known ones according to the purpose. For example, styrene or a substituted polymer thereof, a styrene copolymer, polymethyl methacrylate, Polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic hydrocarbon resin , Alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax and the like. These may be used individually by 1 type and may use 2 or more types together.

Examples of the polymer of styrene or a substituted product thereof include polyester resin, polystyrene, poly p-chlorostyrene, and polyvinyl toluene.
Examples of the styrene copolymer include a styrene-p-chlorostyrene copolymer, a styrene-propylene copolymer, a styrene-vinyltoluene copolymer, a styrene-vinylnaphthalene copolymer, and a styrene-methyl acrylate copolymer. Polymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene- Butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene An acrylonitrile-indene copolymer, Styrene - maleic acid copolymer, styrene - like maleic acid ester copolymer.

The masterbatch can be produced by mixing or kneading the masterbatch resin and the colorant under high shear. At this time, it is preferable to add an organic solvent in order to enhance the interaction between the colorant and the masterbatch resin.
Also, the so-called flushing method is preferable in that the wet cake of the colorant can be used as it is, and there is no need to dry it. This flushing method is a method in which an aqueous paste containing water of a colorant is mixed or kneaded together with a resin and an organic solvent, and the colorant is transferred to the resin side to remove moisture and organic solvent components. For the mixing or kneading, for example, a high shear dispersion device such as a three-roll mill is preferably used.

-Charge control agent-
The charge control agent is not particularly limited and may be appropriately selected from known ones according to the purpose. However, since a color tone may change when a colored material is used, a colorless or nearly white material may be used. Preferably, for example, nigrosine dye, triphenylmethane dye, chromium-containing metal complex dye, molybdate chelate pigment, rhodamine dye, alkoxy amine, quaternary ammonium salt (including fluorine-modified quaternary ammonium salt), alkylamide And a simple substance of phosphorus or a compound thereof, a simple substance of tungsten or a compound thereof, a fluorine-based activator, a metal salt of salicylic acid, a metal salt of a salicylic acid derivative, and the like. These may be used alone or in combination of two or more.
Among these, salicylic acid metal salts and metal salts of salicylic acid derivatives are preferable.

  There is no restriction | limiting in particular as said metal, According to the objective, it can select suitably, For example, aluminum, zinc, titanium, strontium, boron, silicon, nickel, iron, chromium, zirconium etc. are mentioned.

  Commercially available products may be used as the charge control agent. Examples of the commercially available products include quaternary ammonium salt Bontron P-51, oxynaphthoic acid metal complex E-82, and salicylic acid metal complex. E-84, E-89 of a phenol-based condensate (manufactured by Orient Chemical Industry Co., Ltd.), TP-302, TP-415 of a quaternary ammonium salt molybdenum complex (manufactured by Hodogaya Chemical Co., Ltd.), Fourth Copy charge PSY VP2038 of quaternary ammonium salt, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR which is a boron complex -147 (Nippon Carlit Co., Ltd.), quinacridone, azo pigment, other sulfonic acid groups, Carboxyl group, and polymer compounds having a functional group such as a quaternary ammonium salt.

  The charge control agent may be melted and kneaded together with the master batch and then dissolved or dispersed. Alternatively, the charge control agent may be added when dissolved or dispersed directly in the organic solvent together with the components of the image forming toner particles. Alternatively, it may be fixed on the surface of the toner particles for image formation in a toner particle granulating step described later.

  The content of the charge control agent in the toner particles for image formation is not particularly limited and can be appropriately selected according to the type of the binder resin, the presence or absence of an additive, a dispersion method, and the like. 0.1 mass part-10 mass parts are preferable with respect to 100 mass parts of resin, and 1 mass part-5 mass parts are more preferable. When the content is less than 0.1 parts by mass, the charging characteristics of the image forming toner may be deteriorated. When the content exceeds 10 parts by mass, the chargeability of the image forming toner particles becomes too large. The effect of the main charge control agent is diminished, and the electrostatic attraction force with the developing roller is increased, leading to a decrease in developer fluidity and a decrease in image density.

-High polymer particles-
The polymer particles are not particularly limited and may be appropriately selected from known ones according to the purpose. For example, polystyrene, methacrylic acid obtained by soap-free emulsion polymerization, suspension polymerization, dispersion polymerization, etc. Examples thereof include particles formed of acid ester, acrylate copolymer, silicone resin, polycondensation resin such as benzoguanamine, nylon, thermosetting resin, and the like. These may be used alone or in combination of two or more.

-Fluidity improver-
The fluidity improver means a material that can be surface-treated to increase hydrophobicity and prevent deterioration of flow characteristics and charging characteristics even under high humidity.
The fluidity improver is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a silane coupling agent, a silylating agent, a silane coupling agent having a fluorinated alkyl group, and an organic titanate cup. Examples thereof include a ring agent, an aluminum-based coupling agent, silicone oil, and modified silicone oil.

-Cleaning improver-
The cleaning property improving agent is added to the image forming toner in order to remove the transferred developer remaining on the photoreceptor or the primary transfer medium.
The cleaning property improver is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include zinc stearate, calcium stearate, fatty acid metal salts such as stearic acid, polymethyl methacrylate fine particles, polystyrene fine particles Examples thereof include fine polymer particles produced by soap-free emulsion polymerization.
The polymer fine particles preferably have a relatively narrow particle size distribution, and those having a volume average particle size of 0.01 μm to 1 μm are suitable.

-Magnetic material-
There is no restriction | limiting in particular as said magnetic material, According to the objective, it can select suitably, For example, (1) Iron oxide containing magnetic iron oxides, such as a magnetite, a maghemite, a ferrite, or another metal oxide, 2) Metals such as iron, cobalt and nickel, or these metals and aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium, etc. And alloys with these metals, and (3) mixtures thereof.

The magnetic material is not particularly limited and may be appropriately selected depending on the purpose, for _{example, Fe 3 O 4, γ-} Fe 2 O 3, ZnFe 2 O 4, Y 3 Fe 5 O 12, CdFe 2 _{O 4, Gd 3 Fe 5 O} 12, CuFe 2 O 4, PbFe 12 O, NiFe 2 O 4, NdFe 2 O, BaFe 12 O 19, MgFe 2 O 4, MnFe 2 O 4, LaFeO 3, iron powder, cobalt Examples thereof include powder and nickel powder. These may be used individually by 1 type and may be used in combination of 2 or more type. Among these, fine powders of iron trioxide and γ-iron trioxide are preferable.

Moreover, as the magnetic material, magnetic iron oxides such as magnetite, maghemite, and ferrite containing different elements, or a mixture thereof can be used. The heterogeneous element is not particularly limited and can be appropriately selected depending on the purpose. For example, lithium, beryllium, boron, magnesium, aluminum, silicon, phosphorus, germanium, zirconium, tin, sulfur, calcium, scandium, Examples include titanium, vanadium, chromium, manganese, cobalt, nickel, copper, zinc, and gallium. Among these, magnesium, aluminum, silicon, phosphorus, or zirconium is particularly preferable.
The heterogeneous element may be incorporated into the iron oxide crystal lattice, may be incorporated into the iron oxide as an oxide, or may be present on the surface as an oxide or hydroxide. Although it is good, it is preferably contained as an oxide.
The different elements can be incorporated into the particles by mixing the salts of the different elements at the time of producing the magnetic material and adjusting the pH. Moreover, it can precipitate on the particle | grain surface by adjusting pH after magnetic material particle production | generation, or adding salt of each element and adjusting pH.

There is no restriction | limiting in particular as usage-amount of the said magnetic material, Although it can select suitably according to the objective, 10 mass%-200 mass% are preferable with respect to resin, and 20 mass%-150 mass% are more. preferable.
The number average particle size of the magnetic material is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.1 μm to 2 μm, and more preferably 0.1 μm to 0.5 μm.
The number average diameter can be obtained by measuring a photograph taken with a transmission electron microscope with a digitizer or the like.
The magnetic properties of the magnetic material are not particularly limited and can be appropriately selected according to the purpose. However, the magnetic properties at 10 K oersted application are coercive force 20 oersted to 150 oersted, saturation magnetization 50 emu / g to 200 emu / g and residual magnetization of 2 emu / g to 20 emu / g are preferable.
The magnetic material can also be used as a colorant.

<Toner particle granulation process>
The toner particle granulation step is a step of granulating toner particles by dispersing the solution obtained in the solution preparation step in an aqueous medium.
The method of aggregating the toner particles is not particularly limited and may be appropriately selected depending on the intended purpose. The toner material solution (oil phase) is emulsified or dispersed in the aqueous medium (aqueous phase). This may be carried out by removing the organic solvent during or after the extension reaction or crosslinking reaction between the compound having an active hydrogen group and the polymer having a site capable of reacting with the compound having the active hydrogen group. preferable.
In the toner material solution, components other than the polymer (prepolymer) capable of reacting with the active hydrogen group-containing compound are added and mixed in the aqueous medium when the resin fine particles are dispersed in the aqueous medium described later. Alternatively, when the toner material solution is added to the aqueous medium, it may be added to the aqueous medium together with the toner material solution.

<< Aqueous medium >>
There is no restriction | limiting in particular as said aqueous medium, It can select suitably from well-known things, For example, although water may be sufficient, the solvent miscible with water can also be used together. As the solvent miscible with water in the previous period, for example, alcohol (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.), or these Examples thereof include mixed solvents.
The aqueous medium may contain external additives such as resin fine particles and inorganic fine particles as necessary. When the external additive is contained, the external additive can be aggregated on the surface of the toner particles, which is preferable in terms of improving toner properties such as charging property.

-Resin fine particles-
The resin fine particle is not particularly limited as long as it is a resin capable of forming an aqueous dispersion in an aqueous medium, and can be appropriately selected from known resins according to the purpose, and is a thermoplastic resin. It may be a thermosetting resin, for example, vinyl resin, polyurethane resin, epoxy resin, polyester resin, polyamide resin, polyimide resin, silicon resin, phenol resin, melamine resin, urea resin, aniline resin, ionomer resin, polycarbonate. Resin etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.
Among these, at least one selected from vinyl resins, polyurethane resins, epoxy resins, and polyester resins is preferable because an aqueous dispersion of fine spherical resin particles can be easily obtained.

  The vinyl resin is a polymer obtained by homopolymerizing or copolymerizing a vinyl monomer. For example, a styrene- (meth) acrylic acid ester resin, a styrene-butadiene copolymer, a (meth) acrylic acid-acrylic acid ester polymer. Styrene-acrylonitrile copolymer, styrene-maleic anhydride copolymer, styrene- (meth) acrylic acid copolymer, and the like.

  Moreover, as the resin fine particles, a copolymer comprising a monomer having at least two unsaturated groups can be used. The monomer having at least two unsaturated groups is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a sodium salt of methacrylic acid ethylene oxide adduct sulfate (trade name: Eleminol RS- 30; manufactured by Sanyo Chemical Industries, Ltd.), divinylbenzene, 1,6-hexanediol acrylate, and the like.

  There is no restriction | limiting in particular as a volume average particle diameter of the said resin fine particle, Although it can select suitably according to the objective, 20 nm-400 nm are preferable and 30 nm-350 nm are more preferable. When the volume average particle diameter of the resin fine particles is less than 20 nm, the resin fine particles remaining on the surface of the image forming toner particles may be filmed, or the entire surface of the image forming toner particles may be covered densely. As a result, the resin fine particles inhibit the adhesion between the binder resin inside the image forming toner particles and the fixing paper as a transfer material, and the minimum fixing temperature increases. Sometimes. If the volume average particle diameter of the resin fine particles exceeds 400 nm, the resin fine particles inhibit the exudation of the wax component, and sufficient releasability cannot be obtained, which may cause an offset.

  The coverage of the toner particles for image formation of the resin fine particles is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 75% to 100%, more preferably 80% to 100%. If the toner particle coverage is less than 75%, the storage stability of the image forming toner particles is deteriorated, and blocking may occur during storage or use.

  The content of the resin fine particles in the image forming toner particles is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.5% by mass to 8.0% by mass, and 0.6 The mass% to 7.0 mass% is more preferable. When the content is less than 0.5% by mass, the storage stability of the image forming toner deteriorates, and blocking may be observed during storage or use. If it exceeds the above range, the resin fine particles may inhibit the exudation of the wax, so that sufficient releasability cannot be obtained and offset may occur.

-Inorganic fine particles-
The inorganic fine particles are not particularly limited and can be appropriately selected from known ones according to the purpose. For example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate , Zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide , Silicon nitride, and the like. These may be used individually by 1 type and may use 2 or more types together.

There is no restriction | limiting in particular as a primary particle diameter of the said inorganic fine particle, Although it can select suitably according to the objective, 5 nm-2 micrometers are preferable, and 5 nm-500 nm are more preferable.
As the specific surface area by BET method of the inorganic fine ^particles, 20m ² / ^g~500m 2 / g are preferred.

There is no restriction | limiting in particular as content in the said image forming toner of the said inorganic fine particle, Although it can select suitably according to the objective, 0.01 mass%-5.0 mass% are preferable, 0.01 mass % To 2.0% by mass is more preferable.
The inorganic fine particles can be suitably used as an external additive for the image forming toner.

In the toner particle granulation step, when the active hydrogen group-containing compound and the polymer capable of reacting with the active hydrogen group-containing compound are subjected to an extension reaction or a crosslinking reaction, the adhesive base material is generated.
The adhesive substrate (for example, the urea-modified polyester resin is, for example, (1) the toner containing a polymer that can react with the active hydrogen group-containing compound (for example, the isocyanate group-containing polyester prepolymer (A)). The material solution is emulsified or dispersed in the aqueous medium together with the active hydrogen group-containing compound (for example, the amines (B)) to form a dispersion, and both are extended or cross-linked in the aqueous medium. (2) The toner material solution is emulsified or dispersed in the aqueous medium to which the active hydrogen group-containing compound has been added in advance to form a dispersion, and both in the aqueous medium. (3) The toner material solution is added to and mixed with the aqueous medium, and then the active water is added. It may be formed by adding a group-containing compound to form a dispersion, and subjecting both to an extension reaction or a crosslinking reaction from the particle interface in the aqueous medium. A modified polyester resin is preferentially produced on the toner surface, and a density gradient can be provided in the image forming toner particles.

The reaction conditions for producing the adhesive substrate by the emulsification or dispersion are not particularly limited, and may be a combination of the active hydrogen group-containing compound and a polymer capable of reacting with the active hydrogen group-containing compound. It can be appropriately selected depending on the case.
There is no restriction | limiting in particular as said reaction time, Although it can select suitably according to the objective, 10 minutes-40 hours are preferable, and 2 hours-24 hours are more preferable.
There is no restriction | limiting in particular as said reaction temperature, Although it can select suitably according to the objective, 0 to 150 degreeC is preferable and 40 to 98 degreeC is more preferable.

  In the emulsification or dispersion, the amount of the aqueous medium used is not particularly limited and may be appropriately selected depending on the intended purpose, but is 50 parts by mass to 2 parts by mass with respect to 100 parts by mass of the image forming toner raw material. 000 parts by mass is preferable, and 100 parts by mass to 1,000 parts by mass is more preferable. When the amount used is less than 50 parts by mass, the dispersion state of the image forming toner raw material is poor, and toner particles having a predetermined particle size may not be obtained. Cost can be high.

In the emulsification or dispersion, if necessary, it is preferable to use a dispersant from the viewpoint of sharpening the particle size distribution and performing stable dispersion.
There is no restriction | limiting in particular as said dispersing agent, According to the objective, it can select suitably, For example, surfactant, a sparingly water-soluble inorganic compound dispersing agent, a polymeric protective colloid, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, surfactants are preferable.

  Examples of the surfactant include an anionic surfactant, a cationic surfactant, a nonionic surfactant, and an amphoteric surfactant.

  Examples of the anionic surfactant include alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters and the like, and those having a fluoroalkyl group are preferable.

  Examples of the anionic surfactant having a fluoroalkyl group include a fluoroalkylcarboxylic acid having 2 to 10 carbon atoms or a metal salt thereof, disodium perfluorooctanesulfonylglutamate, 3- [omega-fluoroalkyl (6 carbon atoms). -11) oxy] -1-alkyl (3 to 4 carbon atoms) sodium sulfonate, 3-omega-fluoroalkanoyl (6 to 8 carbon atoms) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl ( Carbon number 11-20) carboxylic acid or metal salt thereof, perfluoroalkyl carboxylic acid (carbon number 7-13) or metal salt thereof, perfluoroalkyl (carbon number 4-12) sulfonic acid or metal salt thereof, perfluorooctane Sulfonic acid diethanolamide, N-propyl-N- (2-hydroxy Chill) perfluorooctanesulfonamide, perfluoroalkyl (carbon number 6-10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (carbon number 6-10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (carbon number) 6-16) Ethyl phosphate and the like.

  Examples of commercially available surfactants having a fluoroalkyl group include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.); Fluorard FC-93, FC-95, FC-98, FC -129 (manufactured by Sumitomo 3M Co., Ltd.); Unidyne DS-101, DS-102 (manufactured by Daikin Industries, Ltd.); Megafac F-110, F-120, F-113, F-191, F-812, F- 833 (manufactured by Dainippon Ink Co., Ltd.); Xtop EF-102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products); F150 (manufactured by Neos Co., Ltd.) and the like can be mentioned.

  Examples of the cationic surfactant include amine salt type surfactants and quaternary ammonium salt type cationic surfactants.

Examples of the amine salt type surfactant include alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, imidazolines, and the like.
Examples of the quaternary ammonium salt type cationic surfactant include alkyltrimethylammonium salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, pyridinium salt, alkylisoquinolinium salt, benzethonium chloride and the like. .

  Among the cationic surfactants, aliphatic quaternary ammonium such as aliphatic primary, secondary or tertiary amine acids having a fluoroalkyl group, perfluoroalkyl (6 to 10 carbon atoms) sulfonamidopropyltrimethylammonium salt, etc. Salts, benzalkonium salts, benzethonium chloride, pyridinium salts, imidazolinium salts and the like.

  Commercially available products of the cationic surfactant include, for example, Surflon S-121 (manufactured by Asahi Glass Co., Ltd.); Florard FC-135 (manufactured by Sumitomo 3M Co., Ltd.); Unidyne DS-202 (manufactured by Daikin Industries, Ltd.), MegaFuck F-150, F-824 (manufactured by Dainippon Ink Co., Ltd.); Xtop EF-132 (manufactured by Tochem Products);

  Examples of the nonionic surfactant include fatty acid amide derivatives and polyhydric alcohol derivatives. Examples of the amphoteric surfactant include alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine, N-alkyl-N, N-dimethylammonium betaine, and the like.

  Examples of the poorly water-soluble inorganic compound dispersant include tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, and hydroxyapatite.

  Examples of the polymeric protective colloid include acids, (meth) acrylic monomers containing a hydroxyl group, vinyl alcohol or ethers of vinyl alcohol, esters of vinyl alcohol and a compound containing a carboxyl group, amides Examples thereof include homopolymers or copolymers such as compounds or their methylol compounds, chlorides, those having a nitrogen atom or a heterocyclic ring thereof, polyoxyethylenes, and celluloses.

  Examples of the acids include acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid, maleic anhydride, and the like. Examples of the (meth) acrylic monomer containing a hydroxyl group include β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, and γ-acrylate. -Hydroxypropyl, γ-hydroxypropyl methacrylate, 3-chloro-2-hydroxypropyl acrylate, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate Glycerin monomethacrylate, N-methylolacrylamide, N-methylolmethacrylamide and the like.

Examples of the vinyl alcohol or ethers with vinyl alcohol include vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, and the like.
Examples of the esters of vinyl alcohol and a compound containing a carboxyl group include vinyl acetate, vinyl propionate, and vinyl butyrate.
Examples of the amide compound or these methylol compounds include acrylamide, methacrylamide, diacetone acrylamide acid, or these methylol compounds.
Examples of the chlorides include acrylic acid chloride and methacrylic acid chloride.
Examples of the homopolymer or copolymer such as those having a nitrogen atom or a heterocyclic ring thereof include vinyl pyridine, vinyl pyrrolidone, vinyl imidazole, and ethylene imine.
Examples of the polyoxyethylene are polyoxyethylene, polyoxypropylene, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonylphenyl ether, polyoxyethylene Examples thereof include oxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, and polyoxyethylene nonyl phenyl ester. Examples of the celluloses include methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose.

In the emulsification or dispersion, a dispersion stabilizer can be used as necessary.
Examples of the dispersion stabilizer include acids that are soluble in acids and alkalis such as calcium phosphate salts. When the dispersion stabilizer is used, the calcium phosphate salt can be removed from the fine particles by a method of dissolving the calcium phosphate salt with an acid such as hydrochloric acid and then washing with water or a method of decomposing with an enzyme.

  In the emulsification or dispersion, a catalyst for the extension reaction or the crosslinking reaction can be used. Examples of the catalyst include dibutyltin laurate and dioctyltin laurate.

  The organic solvent is removed from the emulsified slurry obtained in the emulsification or dispersion. The organic solvent is removed by (1) a method in which the entire reaction system is gradually heated to completely evaporate and remove the organic solvent in the droplets, and (2) the emulsion or dispersion is sprayed in a dry atmosphere. And a method of completely removing the water-insoluble organic solvent in the droplets to form toner fine particles and evaporating and removing the aqueous dispersant.

  When the organic solvent is removed, toner particles are formed. In this method, the toner particles can be collected by filtration as a wet cake, washed, dried, etc., and then classified as desired. The classification can be performed, for example, by removing fine particle portions by a cyclone, a decanter, centrifugation, or the like in a liquid, and the classification operation may be performed after obtaining a powder after drying.

<Synthesis process of polymer (prepolymer) capable of reacting with active hydrogen group-containing compound>
Examples of a method for stably forming the dispersion containing a polymer capable of reacting with the active hydrogen group-containing compound (for example, the isocyanate group-containing polyester prepolymer (A)) in the aqueous medium include, for example, the aqueous system. In a medium, a polymer capable of reacting with the active hydrogen group-containing compound dissolved or dispersed in the organic solvent (for example, the isocyanate group-containing polyester prepolymer (A)), the colorant, the release agent, Examples thereof include a method of adding the image forming toner raw material such as a charge control agent and the unmodified polyester resin, and dispersing them by shearing force.

  The dispersion method is not particularly limited and can be appropriately selected using a known disperser. Examples of the disperser include a low-speed shear disperser, a high-speed shear disperser, and a friction disperser. High pressure jet disperser, ultrasonic disperser and the like. Among these, a high-speed shearing disperser is preferable in that the particle size of the dispersion can be controlled to 2 μm to 20 μm. This is preferable in that a toner having a particle diameter can be granulated for the purpose.

When the high-speed shearing disperser is used, conditions such as the number of rotations, dispersion time, dispersion temperature and the like are not particularly limited and can be appropriately selected depending on the purpose.
There is no restriction | limiting in particular as said rotation speed, Although it can select suitably according to the objective, 1,000 rpm-30,000 rpm are preferable, and 5,000 rpm-20,000 rpm are more preferable.
The dispersion time is preferably 0.1 minutes to 5 minutes in the case of a batch method.
The dispersion temperature is preferably 0 ° C. to 150 ° C., more preferably 40 ° C. to 98 ° C. under pressure.
The dispersion temperature is generally easier when the temperature is higher.

  Thus, the obtained toner particles are mixed with particles of the colorant, the release agent, the charge control agent, and the like, or further, a mechanical impact force is applied to the release particles from the surface of the toner particles. It is possible to prevent the particles such as the agent from being detached.

As the method for applying the mechanical impact force, for example, a method in which an impact force is applied to the mixture by blades rotating at a high speed, a mixture is introduced into a high-speed air stream and accelerated to appropriately collide particles or composite particles. The method of making it collide with a board is mentioned.
As an apparatus used in this method, for example, an ong mill (manufactured by Hosokawa Micron Co., Ltd.), an I-type mill (manufactured by Nippon Pneumatic Co., Ltd.) to reduce the pulverization air pressure, and a hybridization system (Nara Machinery Co., Ltd.) Kryptron system (manufactured by Kawasaki Heavy Industries, Ltd.), automatic mortar, and the like.
Through the above steps, the image forming toner particles are formed.

(Image forming toner)
The image forming toner of the present invention is a toner manufactured by the image forming toner manufacturing method of the present invention.

  The shape, size, and the like of the toner particles for image formation are not particularly limited and may be appropriately selected depending on the intended purpose. However, the following thermal characteristics, image density, average circularity, volume average particles It is preferable to have a diameter, a ratio of volume average particle diameter to number average particle diameter (volume average particle diameter / number average particle diameter), and the like.

<Thermal characteristics>
The thermal characteristics are also called flow tester characteristics, and are evaluated as, for example, a softening temperature (Ts), an outflow start temperature (Tfb), a 1/2 method softening point (T1 / 2), and the like.
These thermal characteristics can be measured by an appropriately selected method. For example, the thermal characteristics can be obtained from a flow curve measured using an elevated flow tester CFT500 type (manufactured by Shimadzu Corporation).

  There is no restriction | limiting in particular as said softening temperature (Ts), Although it can select suitably according to the objective, 50 degreeC or more is preferable and 80 to 120 degreeC is more preferable. When the softening temperature (Ts) is less than 50 ° C., at least one of heat resistant storage stability and low temperature storage stability may deteriorate.

  There is no restriction | limiting in particular as said outflow start temperature (Tfb), Although it can select suitably according to the objective, 60 degreeC or more is preferable and 70 to 150 degreeC is more preferable. If the outflow start temperature (Tfb) is less than 60 ° C., at least one of heat resistant storage stability and low temperature storage stability may deteriorate.

  There is no restriction | limiting in particular as said 1/2 method softening point (T1 / 2), Although it can select suitably according to the objective, 60 degreeC or more is preferable and 80 to 170 degreeC is more preferable. If the 1/2 method softening point (T1 / 2) is less than 60 ° C., at least one of heat resistant storage stability and low temperature storage stability may be deteriorated.

<Image density>
The image density is preferably 1.90 or more, more preferably 2.00 or more, and particularly preferably 2.10 or more, as measured by a spectrometer (X-Light, 938 Spectrodensitometer). preferable. If the image density is less than 1.90, the image density may be low and high image quality may not be obtained.

The image density is, for example, imagio Neo450 (manufactured by Ricoh Co., Ltd.), and the amount of developer attached to copy paper (TYPE6000 <70W>: manufactured by Ricoh Co., Ltd.) is 1.00 ± 0.05 mg / cm ^2. A solid image is formed at a surface temperature of the fixing roller of 160 ± 2 ° C., and the image density at any six positions in the obtained solid image is measured with a spectrometer (X-Light Corp., 938 Spectrodensitometer). It can measure by using and measuring and calculating the average value.

<Average circularity>
The average circularity is a value obtained by dividing the perimeter of an equivalent circle having the same projected area as the shape of the image forming toner by the perimeter of the actual particles.
There is no restriction | limiting in particular as said average circularity, Although it can select suitably according to the objective, 0.900-0.980 are preferable and 0.950-0.975 are more preferable. In addition, it is preferable that the particles having an average circularity of less than 0.94 are 15% or less. If the average circularity is less than 0.900, satisfactory transferability and a high-quality image free from dust may not be obtained. If the average circularity exceeds 0.980, image formation employing blade cleaning or the like is employed. In the system, defective cleaning occurs on the photoconductor and the transfer belt, and in the case of image formation with a high image area ratio such as a photographic image, an untransferred image is formed due to defective paper feeding, etc. As a result, the accumulated toner may become a transfer residual toner on the photoconductor, which may cause background smearing of the image, or may contaminate the charging roller for charging the photoconductor in contact with the original charging ability. It may become impossible to demonstrate.

  The average circularity is measured by, for example, an optical detection band method in which a suspension containing toner particles is passed through an imaging unit detection band on a flat plate, and a particle image is optically detected and analyzed by a CCD camera. For example, it can be measured using a flow particle image analyzer FPIA-3000 (manufactured by Sysmex Corporation).

<Volume average particle diameter>
The volume average particle diameter of the image forming toner is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 3 μm to 15 μm, and more preferably 4 μm to 12 μm. When the volume average particle size is less than 3 μm, in the case of a two-component developer, the toner may be fused to the surface of the carrier during a long period of stirring in the developing device, and the charging ability of the carrier may be reduced. In the developer, toner filming on the developing roller and toner fusion to a member such as a blade are likely to occur because the toner is thinned, and if it exceeds 8 μm, the resolution is high and high. It becomes difficult to obtain an image of an image quality, and when the balance of the toner in the developer is performed, the variation in the particle diameter of the toner may increase.

  The ratio of the volume average particle diameter to the number average particle diameter (volume average particle diameter / number average particle diameter) in the image forming toner is not particularly limited and may be appropriately selected depending on the intended purpose. .25 or less is preferable, 1.00 to 1.25 is more preferable, and 1.10 to 1.25 is particularly preferable. When the ratio of the volume average particle diameter to the number average particle diameter (volume average particle diameter / number average particle diameter) exceeds 1.25, the two-component developer causes the surface of the carrier to be agitated for a long period of time in the developing device. The toner may be fused to reduce the charging ability of the carrier. In the case of a one-component developer, the toner filming on the developing roller or the toner is thinned so that the toner is fused to a member such as a blade. May occur easily, and it becomes difficult to obtain a high-resolution and high-quality image, and when the balance of the toner in the developer is performed, the fluctuation of the toner particle size may increase. is there.

  The volume average particle diameter and the ratio of the volume average particle diameter to the number average particle diameter (volume average particle diameter / number average particle diameter) are, for example, a particle size measuring device (Coulter Counter TAII: manufactured by Beckman Coulter, Inc.) ).

  Since the image forming toner is manufactured by the image forming toner manufacturing method of the present invention using the release agent dispersion of the present invention, the image forming toner has excellent heat-resistant storage stability and good chargeability. Since a good image can be obtained over a long period of time without being fused to the photoconductor, it can be suitably used for image formation by various known electrophotographic methods. It can be particularly suitably used for a cartridge, an image forming apparatus, and an image forming method.

(Developer)
A developer using the image forming toner of the present invention is also included in the scope of the present invention.
The developer contains at least the image-forming toner of the present invention and, if necessary, further contains other appropriately selected components such as a carrier.
The developer may be a one-component developer or a two-component developer. However, when the developer is used in a high-speed printer or the like corresponding to the recent improvement in information processing speed, the service life is improved. In view of the above, the two-component developer is preferable.

In the case of the one-component developer using the image-forming toner of the present invention, the toner particle diameter does not fluctuate even if the balance of the toner is performed, and the toner filming on the developing roller or the toner is thinned. The image forming toner is not fused to a member such as a blade for layering, and good and stable developability and an image can be obtained even in the long-term use (stirring) of the developing device.
Further, in the case of the two-component developer using the image forming toner of the present invention, the toner particle diameter in the developer is little changed even if the toner balance is maintained over a long period of time, and long-term agitation in the developing device. In this case, good and stable developability can be obtained.

<Career>
There is no restriction | limiting in particular as said carrier, Although it can select suitably according to the objective, What has a core material and the resin layer which coat | covers this core material is preferable.
There is no restriction | limiting in particular as a material of the said core material, It can select suitably from well-known things, For example, a manganese-strontium (Mn-Sr) type material of 50 emu / g-90 emu / g, manganese-magnesium ( A Mn—Mg) -based material is preferable, and from the viewpoint of securing image density, a highly magnetized material such as iron powder (100 emu / g or more), magnetite (75 emu / g to 120 emu / g) is preferable.
In addition, the weakness of the copper-zinc (Cu-Zn) system (30 emu / g to 80 emu / g) or the like is advantageous in that it can weaken the contact with the photoconductor in which the toner is in a spiked state and is advantageous in improving the image quality. Magnetized materials are preferred. These may be used alone or in combination of two or more.

The particle diameter of the core material is preferably 10 μm to 150 μm, more preferably 40 μm to 100 μm in terms of volume average particle diameter (D50).
When the volume average particle size is less than 10 μm, there are many fine powder systems in the distribution of carrier particles, the magnetization per particle may be lowered and carrier scattering may occur, and when it exceeds 150 μm, the specific surface area decreases. However, toner scattering may occur, and in the case of a full color with many solid portions, reproduction of the solid portions may be particularly deteriorated.

  The material of the resin layer is not particularly limited and can be appropriately selected from known resins according to the purpose. Examples thereof include amino resins, polyvinyl resins, polystyrene resins, halogenated olefin resins, and polyesters. Resin, polycarbonate resin, polyethylene resin, polyvinyl fluoride resin, polyvinylidene fluoride resin, polytrifluoroethylene resin, polyhexafluoropropylene resin, copolymer of vinylidene fluoride and acrylic monomer, vinylidene fluoride and Examples thereof include copolymers with vinyl fluoride, fluoroterpolymers such as terpolymers of tetrafluoroethylene, vinylidene fluoride, and non-fluorinated monomers, and silicone resins. These may be used individually by 1 type and may use 2 or more types together.

Examples of the amino resin include urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, and epoxy resin.
Examples of the polyvinyl resin include acrylic resin, polymethyl methacrylate resin, polyacrylonitrile resin, polyvinyl acetate resin, polyvinyl alcohol resin, and polyvinyl butyral resin.
Examples of the polystyrene resin include polystyrene resin and styrene acrylic copolymer resin. Examples of the halogenated olefin resin include polyvinyl chloride. Examples of the polyester resin include polyethylene terephthalate resin and polybutylene terephthalate resin.

  The resin layer may contain conductive powder or the like as necessary. Examples of the conductive powder include metal powder, carbon black, titanium oxide, tin oxide, and zinc oxide. The average particle diameter of these conductive powders is preferably 1 μm or less. When the average particle diameter exceeds 1 μm, it may be difficult to control electric resistance.

  For example, the resin layer is prepared by dissolving the silicone resin or the like in a solvent to prepare a coating solution, and then uniformly coating the coating solution on the surface of the core material by a known coating method, drying, and baking. It can be formed by doing. Examples of the coating method include a dipping method, a spray method, and a brush coating method.

  There is no restriction | limiting in particular as said solvent, Although it can select suitably according to the objective, For example, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cersol butyl acetate, etc. are mentioned.

  The baking is not particularly limited, and may be an external heating method or an internal heating method. For example, a stationary electric furnace, a fluid electric furnace, a rotary electric furnace, a burner furnace, etc. The method of using, the method of using a microwave, etc. are mentioned.

  There is no restriction | limiting in particular as the quantity in the said carrier of the said resin layer, Although it can select suitably according to the objective, 0.01 mass%-5.0 mass% are preferable. When the amount is less than 0.01% by mass, the uniform resin layer may not be formed on the surface of the core material. When the amount exceeds 5.0% by mass, the resin layer becomes thick. In some cases, granulation of carriers occurs, and uniform carrier particles may not be obtained.

  When the developer is the two-component developer, the content of the carrier in the two-component developer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, 90% by mass to 98% % By mass is preferable, and 93% by mass to 97% by mass is more preferable.

  Since the developer of the present invention contains the toner for image formation, no odor is generated during image formation, excellent chargeability can be secured, and high-quality images can be stably formed. Can do. The developer of the present invention can be suitably used for image formation by various known electrophotographic methods such as a magnetic one-component development method, a non-magnetic one-component development method, and a two-component development method. It can be particularly suitably used for containers, process cartridges, image forming apparatuses and image forming methods.

  EXAMPLES The present invention will be specifically described below with reference to examples of the present invention, but the present invention is not limited to these examples.

<Preparation of release agent dispersion 1>
A paraffin wax having a melting point of 75 ° C. as a mold release agent is placed in a heat-resistant pressure vessel and completely melted at 150 ° C., and then carbon dioxide is used as a supercritical fluid at 150 ° C., 60 MPa, a flow rate of 5.0 L / min (standard state) The volume ratio of carbon dioxide was 94% in terms of conversion value to prepare a mixture of a release agent and supercritical carbon dioxide.
The resulting mixture was mixed with an ethyl acetate solution (30%) containing 3.0% by mass of a styrene-acrylonitrile-butyl acrylate copolymer (copolymer composition ratio 80/10/10 (molar ratio)) as a release agent dispersant. The release agent dispersion liquid 1 was obtained by spraying in the air and releasing into the atmosphere (opening in the region of 0.1 MPa). At this time, the solid content concentration of [Releasing Agent Dispersion 1] was 9.8%.

The release agent-dispersed particle size of the obtained [release agent dispersion liquid 1] was measured with a laser scattering particle size measuring device (LA-920: Horiba, Ltd.). Specifically, 2 mL of 10% by weight release agent dispersant was added to about 200 mL of ethyl acetate, and then [release agent dispersion 1] was added until the transmittance became 85 ± 2%, and sonication was performed. Measurement was performed for 75 minutes. The median diameter in the volume-based particle size distribution was 0.22 μm, and the cumulative frequency of 5.0 μm or more was 0%.
The production conditions of [Releasing Agent Dispersion 1] and the results of laser scattering particle size measurement are shown in Table 1 below.

<Preparation of release agent dispersion 2>
In the production of [Releasing Agent Dispersion 1], the volume ratio of supercritical carbon dioxide was changed to 94% and changed to 80%, in the same manner as in [Releasing Agent Dispersion 1]. Release agent dispersion 2] was prepared.
The release agent-dispersed particle size of the obtained [release agent dispersion liquid 2] was measured by a method similar to that of [release agent dispersion liquid 1] using a laser scattering particle size measurement apparatus. The production conditions of [Releasing Agent Dispersion Liquid 2] and the results of laser scattering particle size measurement are shown in Table 1 below.

<Preparation of release agent dispersion 3>
In the production of [Releasing Agent Dispersion Liquid 1], except that the volume ratio of supercritical carbon dioxide was changed to 94% and changed to 99%, Release agent dispersion 3] was prepared.
The release agent-dispersed particle diameter of the obtained [release agent dispersion liquid 3] was measured by a method similar to that of [release agent dispersion liquid 1] using a laser scattering particle diameter measuring apparatus. Table 1 below shows the production conditions of [Releasing Agent Dispersion Liquid 3] and the results of laser scattering particle size measurement.

<Preparation of release agent dispersion 4>
The production of [Releasing Agent Dispersion 1] was the same as that of [Releasing Agent Dispersion 1] except that the melting temperature of paraffin wax and supercritical carbon dioxide were changed to 150 ° C. to 75 ° C. Thus, [Mold release agent dispersion 4] was produced.
The release agent dispersed particle size of the obtained [release agent dispersion 4] was measured by the same method as [release agent dispersion 1] using a laser scattering particle size measuring apparatus. The production conditions of [Releasing Agent Dispersion 4] and the results of laser scattering particle size measurement are shown in Table 1 below.

<Preparation of release agent dispersion 5>
The production of [Releasing Agent Dispersion 1] is the same as that of [Releasing Agent Dispersion 1] except that the melting temperature of paraffin wax and the temperature of supercritical carbon dioxide are changed to 150 ° C. to 200 ° C. Thus, [Mold release agent dispersion 5] was produced.
The release agent-dispersed particle diameter of the obtained [release agent dispersion liquid 5] was measured by a method similar to that of [release agent dispersion liquid 1] using a laser scattering particle diameter measuring apparatus. The production conditions of [Releasing Agent Dispersion 5] and the results of laser scattering particle size measurement are shown in Table 1 below.

<Preparation of release agent dispersion 6>
In producing [Releasing Agent Dispersion 1], the same procedure as in [Releasing Agent Dispersion 1] was performed except that the pressure during mixing of paraffin wax and supercritical carbon dioxide was changed to 60 MPa to 5 MPa. Thus, [Mold release agent dispersion 6] was produced.
The release agent dispersed particle size of the obtained [release agent dispersion 6] was measured by the same method as [release agent dispersion 1] using a laser scattering particle size measuring apparatus. The production conditions of [Releasing Agent Dispersion 6] and the results of laser scattering particle size measurement are shown in Table 1 below.

<Preparation of release agent dispersion 7>
In the production of [Releasing Agent Dispersion Liquid 1], the same procedure as in the production of [Releasing Agent Dispersion Liquid 1] was performed except that the pressure during mixing of paraffin wax and supercritical carbon dioxide was changed to 60 MPa to 100 MPa. Thus, [Mold release agent dispersion liquid 7] was produced.
The release agent-dispersed particle diameter of the obtained [release agent dispersion liquid 7] was measured by a method similar to that of [release agent dispersion liquid 1] using a laser scattering particle diameter measuring apparatus. The production conditions of [Releasing Agent Dispersion 7] and the results of laser scattering particle size measurement are shown in Table 1 below.

<Preparation of release agent dispersion 8>
Preparation of [Releasing Agent Dispersion 1], except that in the preparation of [Releasing Agent Dispersion 1], carnauba wax having a melting point of 85 ° C. was used in place of the paraffin wax having a melting point of 75 ° C. used as the release agent. In the same manner as described above, [Mold release agent dispersion 8] was produced.
The release agent dispersed particle size of the obtained [release agent dispersion 8] was measured by the same method as [release agent dispersion 1] using a laser scattering particle size measuring apparatus. The production conditions of [Releasing Agent Dispersion 8] and the results of laser scattering particle size measurement are shown in Table 2 below.

<Preparation of release agent dispersion 9>
[Mold Release Agent Dispersion 1] In the same manner as [Mold Release Agent Dispersion 1], except that the supercritical fluid is nitrogen instead of carbon dioxide, [Mold Release Agent Dispersion 1]. 9] was produced.
The release agent dispersed particle size of the obtained [release agent dispersion 9] was measured by the same method as [release agent dispersion 1] using a laser scattering particle size measuring apparatus. The preparation conditions of [Releasing Agent Dispersion 9] and the results of laser scattering particle size measurement are shown in Table 2 below.

<Preparation of mold release agent dispersion 10>
In the production of [Releasing Agent Dispersion 1], the amount of styrene-acrylonitrile-butyl acrylate copolymer (copolymer composition ratio 80/10/10 (molar ratio)) in ethyl acetate was 3.0% by mass. [Release agent dispersion liquid 10] was produced in the same manner as in [Release agent dispersion liquid 1] except that the content was changed to 0%.
The release agent dispersed particle size of the obtained [release agent dispersion 10] was measured by the same method as [release agent dispersion 1] using a laser scattering particle size measuring apparatus. The production conditions of [Releasing Agent Dispersion Liquid 10] and the results of laser scattering particle size measurement are shown in Table 2 below.

<Preparation of release agent dispersion 11>
In the production of [Releasing Agent Dispersion Liquid 1], except that the solvent for collecting the releasing agent fine particles was toluene instead of ethyl acetate, [Mold release agent dispersion 11] was produced.
The release agent-dispersed particle diameter of the obtained [release agent dispersion 11] was measured by the same method as [release agent dispersion 1] using a laser scattering particle size measuring apparatus. The production conditions of [Releasing Agent Dispersion 11] and the results of laser scattering particle size measurement are shown in Table 2 below.

<Preparation of release agent dispersion 12>
A mixture of paraffin wax having a melting point of 75 ° C. as a release agent, ethyl acetate, and a styrene-acrylonitrile-butyl acrylate copolymer (a copolymer composition ratio of 80/10/10 (molar ratio)) as a release agent dispersant. After melting at 77 ° C., the crystallization liquid obtained by rapid cooling was dispersed with a bead mill to obtain [Partitioner Dispersion Liquid 12].
The release agent-dispersed particle size of the obtained [release agent dispersion liquid 12] was measured by a method similar to that of [release agent dispersion liquid 1] using a laser scattering particle size measuring apparatus. The production conditions of [Releasing Agent Dispersion 12] and the results of laser scattering particle size measurement are shown in Table 2 below.

<Preparation of release agent dispersion 13>
The production of [Releasing Agent Dispersion 1] was the same as that of [Releasing Agent Dispersion 1], except that the volume ratio of supercritical carbon dioxide was changed from 94% to 70%. Thus, [Partner Dispersant 13] was prepared.
The release agent-dispersed particle size of the obtained [release agent dispersion 13] was measured by the same method as that of [Release agent dispersion 1] using a laser scattering particle size measuring apparatus. The production conditions of [Releasing Agent Dispersion 13] and the results of laser scattering particle size measurement are shown in Table 2 below.

<Evaluation of production time and production energy>
The production time and production energy of the obtained [release agent dispersion 1] to [release agent dispersion 13] were calculated by the following equations. The results are shown in Tables 1 and 2 below.
Production time = treatment time [h] / treated release agent [kg]
Production energy = Processing energy [kWh] / Processed release agent [kg]
The processing energy was measured with a watt-hour meter.

Example 1
-Synthesis of organic fine particle emulsion-
In a reaction vessel equipped with a stirrer and a thermometer, 683 parts of water, 11 parts of sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30, Sanyo Chemical Industries, Ltd.), 83 parts of styrene, 83 parts of methacrylic acid Parts, 110 parts of butyl acrylate, and 1 part of ammonium persulfate were added and stirred at 400 rpm for 15 minutes to obtain a white emulsion. Then, the system was heated to raise the temperature in the system to 75 ° C. and reacted for 5 hours. Further, 30 parts of a 1% by weight ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 5 hours to be a vinyl resin (a copolymer of styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt). An aqueous dispersion [fine particle dispersion 1] was obtained.
When [Fine Particle Dispersion 1] was measured by a laser scattering particle size measuring apparatus (LA-920) in the same manner as [Releasing Agent Dispersion 1], the volume average particle size was 105 nm.
Next, a part of [Fine Particle Dispersion 1] was dried to isolate the resin component.

<Measurement of glass transition point (Tg)>
The glass transition point (Tg) of the isolated resin was measured by the following method.
About 10 mg of a sample (resin content) was placed in an aluminum sample container, placed on a holder unit, and set in an electric furnace. After heating from room temperature to 150 ° C. at a rate of temperature increase of 10 ° C./min, let stand at 150 ° C. for 10 minutes, cool the sample to room temperature and leave it for 10 minutes, then raise the temperature to 150 ° C. again in a nitrogen atmosphere at 10 ° C./min And DSC measurement was performed with a thermal analysis measuring machine (TG-DSC system TAS-100: manufactured by Rigaku Corporation). Tg was calculated from the contact point between the tangent line of the endothermic curve near the Tg and the base line using the analysis system in the TAS-100 system. As a result, the Tg (° C.) of the isolated resin was 59 ° C.

<Measurement of mass average molecular weight and number average molecular weight>
Moreover, the mass average molecular weight of the isolated resin was measured by GPC (gel permeation chromatography, HLC-8220 GPC, manufactured by Tosoh Corporation) by the following method.
The column was stabilized in a heat chamber at 40 ° C., and tetrahydrofuran (THF) as a solvent was passed through the column at this temperature at a flow rate of 1 mL / min, and the sample (resin content) concentration was 0.05 mass% to 0.06 mass. The THF sample solution of the resin prepared in% was injected at 50 μL to 200 μL and measured. In measuring the weight average molecular weight of the sample, the weight average molecular weight distribution of the sample was calculated from the relationship between the logarithmic value of the prepared calibration curve and the number of counts using several monodisperse polystyrene standard samples. As a standard polystyrene sample for preparing a calibration curve, mass average molecular weights manufactured by Toyo Soda Industry Co., Ltd. are 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , 5.1 ×. Use 10 ⁴ , 1.1 × 10 ⁵ , 3.9 × 10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶ , and use at least 10 standard polystyrene samples It was. An RI (refractive index) detector was used as the detector.
As a result, the mass average molecular weight of the isolated resin was 150,000.
The number average molecular weight can also be measured by the same method as the mass average molecular weight.

-Preparation of aqueous phase-
990 parts of water, 83 parts of [fine particle dispersion 1], 37 parts of a 48.5% by weight aqueous solution of sodium dodecyl diphenyl ether disulfonate (trade name Eleminol MON-7: Sanyo Chemical Industries, Ltd.) and 90 parts of ethyl acetate are mixed and stirred. As a result, a milky white liquid was obtained. This was designated as [Aqueous Phase 1].

-Synthesis of low molecular weight polyester-
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 229 parts of bisphenol A ethylene oxide 2 mol adduct (manufactured by Nippon Emulsifier Co., Ltd.), bisphenol A propylene oxide 2 mol adduct (manufactured by Nippon Emulsifier Co., Ltd.) 529 parts, 208 parts of terephthalic acid, 46 parts of adipic acid, and 2 parts of dibutyltin oxide were reacted at 230 ° C. for 8 hours at normal pressure, and further reacted for 5 hours at a reduced pressure of 10 mmHg to 15 mmHg. Was added 44 parts of trimellitic anhydride and reacted at 180 ° C. and normal pressure for 2 hours to obtain [Low molecular weight polyester 1].
When the mass average molecular weight and Tg of the obtained [low molecular weight polyester 1] were measured by the same method as in [Fine particle dispersion 1], the mass average molecular weight was 6,700 and Tg was 43 ° C.
Further, the number average molecular weight was measured by the same method as that for the mass average molecular weight, and it was 2,500.

<Measurement of acid value>
Moreover, when the acid value of the obtained [low molecular polyester 1] was measured by a titration method based on JIS K0070, the acid value was 25.

-Synthesis of polyester prepolymer-
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 682 parts of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, 22 parts of trimellitic anhydride And 2 parts of dibutyltin oxide were added, reacted at 230 ° C. at normal pressure for 8 hours, and further reacted at reduced pressure of 10 mmHg to 15 mmHg for 5 hours to obtain [Intermediate Polyester 1].
The number average molecular weight, weight average molecular weight, Tg, and acid value of [Intermediate Polyester 1] were measured in the same manner as [Low Molecular Polyester 1]. 500, Tg was 55 ° C., and the acid value was 0.5.

<Measurement of hydroxyl value>
In addition, the hydroxyl value of [Intermediate Polyester 1] was measured by a titration method based on JIS K0070 to be 51.

Next, 410 parts of [Intermediate Polyester 1], 89 parts of isophorone diisocyanate and 500 parts of ethyl acetate are placed in a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, and reacted at 100 ° C. for 5 hours. Polymer 1] was obtained.
It was 1.53 mass% when the free isocyanate amount (mass%) of the obtained [prepolymer] was measured by the titration method.

-Synthesis of ketimine-
In a reaction vessel equipped with a stirrer and a thermometer, 170 parts of isophoronediamine and 75 parts of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to obtain [ketimine compound].
The amine value of the obtained [ketimine compound] was measured by a titration method based on JIS K7237 to be 418.

-Production of master batch (MB)-
1,200 parts of water, 540 parts of carbon black (Printex35: manufactured by Dexa) [DBP oil absorption = 42 mL / 100 mg, pH = 9.5] and 1,200 parts of polyester resin were added, and Henschel mixer (manufactured by Nippon Coke Industries, Ltd.) ), And the mixture was kneaded at 150 ° C. for 30 minutes using two rolls, rolled and cooled, and pulverized with a pulverizer to obtain a [masterbatch].

-Preparation of oil phase ([pigment / wax dispersion 1])-
In a container equipped with a stirring blade, 186 parts of [Partner Dispersion Liquid 1] was charged, and 101 parts of ethyl acetate was charged. Next, while stirring the contents of the container, 60 parts of [Masterbatch 1] and 246 parts of [Low molecular weight polyester 1] were added to the container and mixed for 1 hour to obtain [Raw material solution 1].
[Raw material solution 1] 600 parts were transferred to a container and mixed with a TK homomixer at a rotation speed of 8,000 rpm for 1 hour to obtain [Pigment / wax dispersion 1].
The solid content concentration of the obtained [Pigment / Wax Dispersion 1] was measured by a drying method and found to be 55% by mass.
-Emulsification, desolvation-
[Pigment / Wax Dispersion 1] 600 parts, [Prepolymer 1] 60 parts, [Ketimine Compound 1] 4.6 parts in a container, 5,000 rpm with TK Homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) After mixing for 1 minute, 1,200 parts of [Aqueous phase 1] was added to the container and mixed with a TK homomixer at 13,000 rpm for 1 minute to obtain [Emulsion slurry 1]. [Emulsion slurry 1] was put into a container equipped with a stirrer and a thermometer, and after removing the solvent for 8 hours at 30 ° C., aging was performed at 40 ° C. for 4 hours to obtain [Dispersion slurry 1]. The obtained [Dispersion Slurry 1] was washed and then dried for 48 hours to obtain a toner.

<Measurement of volume average particle diameter and number average particle diameter>
The volume average particle diameter and number average particle diameter of the obtained toner were measured by the Coulter counter method as follows.
As an electrolytic aqueous solution, about 1% by mass of a sodium chloride aqueous solution (ISOTON-II: manufactured by Beckman Coulter Co., Ltd.) 100 mL to 150 mL prepared using primary sodium chloride, 0.1 mL to alkylbenzene sulfonate as a dispersant is added. 5 mL was added, and 2 mg to 20 mg of a measurement sample (toner) was further added.
The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 minute to 3 minutes, and a 100 μm aperture is used as an aperture by a Coulter counter (Coulter counter TA-II: manufactured by Beckman Coulter, Inc.). Then, the volume and the number distribution of the toner were measured, and the volume distribution and the number distribution were calculated.
Channels are 2.00 μm to less than 2.52 μm; 2.52 μm to less than 3.17 μm; 3.17 μm to less than 4.00 μm; 4.00 μm to less than 5.04 μm; 5.04 μm to less than 6.35 μm; .35 μm to less than 8.00 μm; 8.00 μm to less than 10.08 μm; 10.08 μm to less than 12.70 μm; 12.70 μm to less than 16.00 μm; 16.00 μm to less than 20.20 μm; Less than 40 [mu] m; 25.40 [mu] m to less than 32.00 [mu] m; 13 channels of 32.00 [mu] m to less than 40.30 [mu] m were used, and particles with a particle size of 2.00 [mu] m to less than 40.30 [mu] m were targeted.
Further, the volume-based volume average particle diameter (Dv) obtained from the calculated volume distribution and the number average particle diameter (Dn) obtained from the number distribution and the ratio Dv / Dn were obtained.
As a result, the volume average particle diameter (Dv) of the toner was 5.22 μm, the number average particle diameter (Dn) was 4.55 μm, and the ratio (Dv / Dn) thereof was 1.15.

-Production of developer-
To 100 parts by mass of the obtained toner, 0.8 part of silica having an average particle diameter of 12 nm (trade name RX200: manufactured by Nippon Aerosil Co., Ltd.), which has been subjected to a hydrophobic treatment, is added and subjected to a surface treatment using a Henschel mixer. Thus, [Developer 1] was produced.

(Example 2)
A toner was prepared in the same manner as in Example 1 except that [Releasing Agent Dispersion 2] was used instead of [Releasing Agent Dispersion 1], and [Developer 2] was obtained. It was.

(Example 3)
A toner was prepared in the same manner as in Example 1 except that [Releasing Agent Dispersion 3] was used instead of [Releasing Agent Dispersion 1], and [Developer 3] was obtained. It was.

Example 4
In Example 1, a toner was prepared in the same manner as in Example 1 except that [Releasing Agent Dispersion 4] was used instead of [Releasing Agent Dispersion 1], and [Developer 4] was obtained. It was.

(Example 5)
A toner was prepared in the same manner as in Example 1 except that [Releasing Agent Dispersion Liquid 1] was used instead of [Releasing Agent Dispersion Liquid 1] in Example 1, and [Developer 5] was obtained. It was.

(Example 6)
A toner was prepared in the same manner as in Example 1 except that [Releasing Agent Dispersion Liquid 1] was used instead of [Releasing Agent Dispersion Liquid 1] in Example 1, and [Developer 6] was obtained. It was.

(Example 7)
In Example 1, a toner was prepared in the same manner as in Example 1 except that [Releasing Agent Dispersion 7] was used instead of [Releasing Agent Dispersion 1], and [Developer 7] was obtained. It was.

(Example 8)
In Example 1, a toner was prepared in the same manner as in Example 1 except that [Releasing Agent Dispersion 1] was used instead of [Releasing Agent Dispersion 1], and [Developer 8] was obtained. It was.

Example 9
A toner was prepared in the same manner as in Example 1 except that [Releasing Agent Dispersion 1] was used instead of [Releasing Agent Dispersion 1], and [Developer 9] was obtained. It was.

(Example 10)
In Example 1, a toner was prepared in the same manner as in Example 1 except that [Releasing Agent Dispersion 10] was used instead of [Releasing Agent Dispersion 1], and [Developer 10] was obtained. It was.

(Example 11)
A toner was prepared in the same manner as in Example 1 except that [Releasing Agent Dispersion 11] was used instead of [Releasing Agent Dispersion 1], and [Developer 11] was obtained. It was.

(Comparative Example 1)
A toner was prepared in the same manner as in Example 1 except that [Releasing Agent Dispersion 12] was used instead of [Releasing Agent Dispersion 1], and [Developer 12] was obtained. It was.

(Comparative Example 2)
In Example 1, a toner was prepared in the same manner as in Example 1 except that [Releasing Agent Dispersion Liquid 13] was used instead of [Releasing Agent Dispersion Liquid 1], and [Developer 13] was obtained. It was.

  The toners and developers of Examples 1 to 11 and Comparative Examples 1 and 2 thus obtained were measured for toner physical properties and image density and evaluated for fusing as follows. The results are shown in Tables 3 to 4 below.

<Evaluation of fixability>
The toner obtained in Examples 1 to 11 and Comparative Examples 1 and 2 was modified with an apparatus using a Teflon (registered trademark) roller as a fixing roller by modifying a fixing unit of a copying machine (MF2200: manufactured by Ricoh Co., Ltd.). Using this, paper (type 6200: manufactured by Ricoh Co., Ltd.) was set thereon, and a copy test was performed. The cold offset temperature (fixing lower limit temperature) and the hot offset temperature (hot offset resistant temperature) were determined by changing the fixing temperature.
The fixing minimum temperature of the conventional low-temperature fixing toner is about 140 ° C. to 150 ° C. The evaluation conditions for low-temperature fixing are as follows: the linear speed of paper feed is 1,200 mm / sec to 150 mm / sec, the surface pressure is 1.2 kgf / cm ² , the nip width is 3 mm, and the evaluation conditions of high temperature offset are the linear speed of paper feed. The settings were 50 mm / second, surface pressure 2.0 kgf / cm ² , and nip width 4.5 mm.

<Evaluation of heat-resistant storage stability>
After the toners obtained in Examples 1 to 11 and Comparative Examples 1 and 2 were stored at 55 ° C. for 8 hours, the toner was sieved with a 42 mesh sieve for 2 minutes. It was. A toner having better heat-resistant storage stability has a lower residual ratio, and thus was evaluated based on the following evaluation criteria.
Residual rate (%) = toner mass after sieving / toner mass before sieving × 100
[Evaluation criteria]
×: Residual rate is 30% or more Δ: Residual rate is 20% to 30%
○: Residual rate is 10% to 20%
A: Residual rate is less than 10%

<Evaluation of charge amount>
(1) Stir charge amount for 15 seconds 10 g of toner obtained in Examples 1 to 11 and Comparative Examples 1 and 2 and 100 g of ferrite carrier are made of stainless steel up to 30% of the internal volume in an environment with a temperature of 28 ° C. and a humidity of 80%. The developer was charged in a pot and stirred for 15 seconds at a stirring speed of 100 rpm, and the charge amount (μC / g) of the developer was measured by a blow-off method using a charge amount measuring device (TB-200: manufactured by Toshiba Chemical Corporation).
(2) Agitated charge amount for 10 minutes The measurement of the agitated charge amount in (1) is the same as the measurement of the agitated charge amount in (1) except that the agitated charge amount is changed to agitated for 15 seconds and stirred for 10 minutes. The charge amount was measured by this method.

<Evaluation of image density>
Using the obtained developers 1 to 13, the amount of the developer adhered to the copy paper (TYPE6000 <70W>: manufactured by Ricoh Co., Ltd.) with a tandem type color electrophotographic apparatus (image Neo 450: manufactured by Ricoh Co., Ltd.) is 1. A solid image of 00 ± 0.05 mg / cm ² was formed.
The solid image was repeatedly formed on 8,000 copy sheets. The image density of the obtained solid image was visually observed at the initial stage and after endurance of 8,000 sheets, and evaluated based on the following evaluation criteria. The higher the image density obtained, the higher the density image can be formed.
[Evaluation criteria]
◯: There was no change in image density and high image quality was obtained at the initial stage and after endurance of 8,000 sheets.
[Delta]: After 8,000 sheets were used, the image density was slightly lowered and the image quality was lowered.
X: After the endurance of 8,000 sheets, the image density was remarkably lowered and the image quality was greatly lowered.

<Fusion>
In the evaluation of the image density, the toner obtained in Examples 1 to 11 and Comparative Examples 1 and 2 to an OPC (Organic Photoconductor) photoreceptor was visually observed after image formation, and based on the following evaluation criteria. evaluated.
[Evaluation criteria]
○: No fusion of toner to the photoreceptor was observed.
X: Fusion of toner to photoreceptor was observed.

The method for producing a release agent dispersion according to the present invention is an efficient release in both productivity and production energy, and contains a release agent dispersion having a small particle size of uniform submicron order and uniform release agent fine particles, and having no impurities. Since it can be produced in a short time, it is suitably used for producing a release agent dispersion used in a method for producing an image forming toner.
Further, the release agent dispersion of the present invention is suitably used for the production of an image forming toner because the release agent contained in the release agent dispersion has a small particle size and uniform on the order of submicrons. .
In addition, since the image forming toner of the present invention uses the release agent dispersion of the present invention, the image forming toner of the present invention produced thereby has excellent heat-resistant storage stability and chargeability. It can be used for image formation by various known electrophotographic methods without being fused to the photoreceptor during image formation, and can be suitably used for image formation by various known electrophotographic methods. It can be suitably used for a cartridge, an image forming apparatus, an image forming method, and the like.

DESCRIPTION OF SYMBOLS 1 Mold release agent melt phase 2 Liquid feeding apparatus 3 Liquid feeding apparatus 4 Mixing part 5 High pressure nozzle 6 Liquid solvent 7 Chamber

Japanese Patent No. 2537503 JP-A-9-34167 JP-A-11-149180 JP 2005-258394 A JP 2008-70583 A

Claims (17)

A mixture preparation step of preparing a mixture containing 80% to 99% by volume of the supercritical fluid or subcritical fluid by mixing the molten release agent with a supercritical fluid or subcritical fluid;
A release agent fine particle granulating step of spraying the mixture to rapidly expand, granulating the release agent to form release agent fine particles;
A release agent dispersion preparation step of collecting the release agent fine particles in a liquid solvent to prepare a release agent dispersion, and a method for producing a release agent dispersion.   The method for producing a release agent dispersion according to claim 1, wherein the temperature of the mixture is not lower than the melting temperature of the release agent and not higher than 200 ° C.   The method for producing a release agent dispersion according to claim 1, wherein the pressure of the mixture is 5 MPa to 100 MPa.   The method for producing a release agent dispersion according to any one of claims 1 to 3, wherein the supercritical fluid or subcritical fluid contains at least carbon dioxide.   The method for producing a release agent dispersion according to any one of claims 1 to 4, wherein the liquid solvent contains at least a release agent dispersant.   The method for producing a release agent dispersion according to any one of claims 1 to 5, wherein the release agent is at least one selected from paraffin wax, microcrystalline wax, ester wax, carnauba wax, and rice wax.   The method for producing a release agent dispersion according to any one of claims 1 to 6, wherein the solubility parameter (SP value) of the liquid solvent is 7 to 11.   It is obtained by the method for producing a release agent dispersion according to any one of claims 1 to 7, and a median diameter in a volume-based particle size distribution of the release agent fine particles is 0.2 µm to 3.0 µm, and at least 5. A release agent dispersion liquid, wherein an integration frequency of the release agent fine particles of 0 μm is 5.0% or less.   A method for producing an image forming toner, wherein the release agent dispersion according to claim 8 is used. A solution preparation step of preparing a solution obtained by dissolving the release agent dispersion according to claim 8 in a toner material solution;
The toner forming method according to claim 9, further comprising: a toner particle granulating step of granulating toner particles by dispersing the solution obtained in the dissolving liquid preparing step in an aqueous medium. In the organic solvent, the solution preparation step includes a release agent dispersion, a compound having an active hydrogen group, a polymer having a site capable of reacting with the compound having an active hydrogen group, a binder resin, and coloring. By dispersing the agent,
A toner particle granulation step is performed by removing the organic solvent during or after the reaction between the compound having an active hydrogen group and a polymer having a site capable of reacting with the compound having an active hydrogen group. The method for producing an image forming toner according to claim 10.   The method for producing a toner for image formation according to any one of claims 10 to 11, obtained by agglomerating resin fine particles in an aqueous medium.   The method for producing an image forming toner according to claim 11, wherein the binder resin is a polyester resin.   The method for producing an image forming toner according to claim 13, wherein the polyester resin has a glass transition temperature (Tg) of 30 ° C. to 70 ° C.   An image-forming toner obtained by the toner production method according to claim 9.   The toner for image formation according to claim 15, wherein the weight average particle diameter is 3 μm to 15 μm.   17. The image forming toner according to claim 15, wherein the ratio (Dv / Dn) of the weight average particle diameter (Dv) to the number average particle diameter (Dn) is 1.25 or less.