JP5451062B2 - Method for producing toner particles - Google Patents

Description

  The present invention relates to a toner and a toner particle manufacturing method for developing an electrostatic image in an image forming method such as electrophotography, electrostatic printing, and magnetic recording. In particular, the present invention relates to a method for producing toner particles for preventing adhesion of a polymer scale to an inner wall surface of a polymerization vessel when producing toner particles by polymerization.

  Many methods of electrophotography are known. In general, a photoconductive substance is used, and an electric latent image is formed on a photoreceptor by various means. Next, the latent image is developed using toner, and the toner image is transferred onto a transfer material such as paper as necessary. Then, the latent image is fixed by heating, pressure, solvent vapor or the like to obtain a copy. Various methods have been proposed in the past as a method for developing with toner or a method for fixing a toner image, and a method suitable for each image forming process is employed.

  In recent years, toners are roughly classified into pulverized toners and wet granulated toners. The pulverized toner is obtained by melt-kneading a colorant in a thermoplastic resin and uniformly dispersing it, then cooling and solidifying the melt-kneaded product, pulverizing the kneaded product with a pulverizer, and classifying the pulverized product with a classifier. It is manufactured by obtaining toner particles having a desired particle size.

  On the other hand, wet granulated toner is attracting attention because it can reduce the particle size and sharpen the particle size distribution and is advantageous for introducing a large amount of a release agent. As specific toner production methods for wet granulation, various polymerization method production methods such as suspension polymerization method, emulsion polymerization method, dissolution suspension method using separately polycondensed polyester, etc. have been proposed. ing.

  For example, in the suspension polymerization method, a polymerizable monomer and a colorant (and a polymerization initiator, a crosslinking agent, a charge control agent and other additives as necessary) are uniformly dissolved or dispersed to form a polymerizable monomer composition. Then, the polymerizable monomer composition is dispersed in a continuous phase (for example, an aqueous phase) containing a dispersion stabilizer using an appropriate stirrer, and a polymerization reaction is performed to obtain a desired particle size. Toner particles are obtained. Thereafter, the toner is manufactured through filtration, washing, drying, and classification (see Patent Document 1).

  In the emulsion polymerization method, first, a monomer composition containing a polymerizable monomer, a polymerization initiator, a surfactant and, if necessary, a crosslinking agent, a chain transfer agent, and other additives in an aqueous medium. Dispersion is carried out using a suitable stirrer, and a polymerization reaction is carried out to obtain emulsified resin particles having a desired particle size. Thereafter, the colorant is uniformly finely dispersed in an aqueous medium containing a surfactant, and is associated (aggregated and fused) with the emulsified resin particles to obtain a toner particle dispersion having a desired particle size. Thereafter, the toner is produced through filtration, washing, drying and classification in the same manner as in the suspension polymerization method and the dissolution suspension method (see Patent Document 2).

  In these toner particle production methods by the polymerization method, adhesion occurs on the inner wall surface of the polymerization vessel by the polymer scale of the dispersed droplets. The adhesion of the polymer scale becomes more prominent as the number of polymerization batches increases, and the toner scale decreases and the polymer scale peeled off from the inner wall surface of the polymerization container is mixed into the toner particles as irregularly shaped particles. Adversely affects sex. The adhesion of the scale to the polymerization vessel wall surface reduces the heat transfer coefficient of the polymerization vessel, making it difficult to control the temperature during polymerization or reducing the heat transfer efficiency from the jacket. Moreover, the removal work of the scale adhering to the inner wall surface or the like of the polymerization vessel requires excessive labor and time, and the operation rate of the apparatus is reduced, leading to a decrease in production efficiency.

  As a method for preventing scale adhesion in such a polymerization reaction, a method for forming a scale preventive coating film by forming an inorganic dispersed powder layer on a sticky inorganic compound layer in which colloidal silica and alkyl silicate are mixed on the inner wall surface of the polymerization vessel ( Patent Document 3) has been proposed. In this method, repulsion between the inorganic dispersed powder layer and the dispersed droplets of the polymerizable monomer is insufficient, and a satisfactory scale prevention effect cannot be obtained.

  A method for preventing adhesion of polymer scale by applying a scale inhibitor containing a condensation reaction product of an aldehyde compound and a hydroxynaphthalene compound and a vinylphenol polymer to the inner wall of the polymerization vessel (see Patent Document 4). Proposed. In this method, a part of the used scale inhibitor migrates into the toner particles and / or the toner particle surface, which adversely affects the developability.

  In addition, as a method for preventing scale from entering the gas phase part and the gas-liquid interface in the polymerization vessel, a method of spraying an aqueous dispersion medium containing water or a dispersion stabilizer on the inner wall of the gas phase part in the polymerization vessel during the polymerization is clearly shown. (See Patent Document 5). However, there is no effect in suppressing the polymer scale in the polymerization vessel liquid.

  Furthermore, the dispersion of the aqueous dispersion medium containing the dispersion stabilizer on the inner wall of the polymerization vessel, and the dispersion of the polymerizable monomer composition mixed with the aqueous dispersion medium containing the dispersion stabilizer separately prepared A method for preventing scale by simultaneously charging the polymerization vessel is disclosed (see Patent Document 6). However, it is not possible to prevent the scale generated with the temperature rise and / or the liquid level drop during the polymerization. Further, according to the examination by the present applicant, this method has not provided a sufficient scale prevention effect.

Japanese Patent Laid-Open No. 51-14895 JP-A-5-265252 JP-A-5-287564 JP 2006-160960 A JP-A-10-153878 Japanese Patent Laid-Open No. 2003-287928

  An object of the present invention is to provide a method for producing toner particles that solves the above-described problems.

  That is, the present invention relates to a method for producing toner particles by a polymerization method, which suppresses the occurrence of adhesion of a polymer scale generated on the inner wall of a polymerization vessel when polymerizing dispersed droplets of a polymerizable monomer composition. It aims at providing the manufacturing method of.

  It is another object of the present invention to provide a method for producing toner particles having excellent image characteristics by suppressing adhesion of a polymer scale.

To achieve the above object, a first invention of the present application, a polymerizable monomer composition containing a polymerizable monomer and a colorant, an aqueous dispersion medium containing an inorganic dispersion stabilizer (Liquid A ) was dispersed in the granulation process to prepare a polymerizable monomer composition dispersion and,
In the production method of the toner particles containing at least the polymerizable monomer composition Ru by polymerizing the polymerization process which is present as droplets in the polymerizable monomer composition dispersion,
The production method further includes a step of bringing a liquid (liquid B) containing a poorly water-soluble inorganic compound into contact with at least a part of the inner wall of the polymerization vessel used in the polymerization step, followed by drying .
A method for producing toner particles, wherein the hardly water-soluble inorganic compound is a hardly water-soluble metal phosphate obtained by mixing an alkali metal phosphate aqueous solution and a metal halide aqueous solution. The content.

  According to the present invention, it is possible to effectively prevent not only the liquid phase part on the inner wall of the polymerization vessel in the polymerization step of the polymerizable monomer composition but also the adhesion of the polymer scale to the vicinity of the gas-liquid interface and to the gas phase part. . Further, irregularly shaped particles due to peeling of the scale into the toner particles are very rarely mixed, and hardly water-soluble inorganic compounds hardly remain in the toner particles. By these effects, toner particles can be produced stably and efficiently, and toner particles having excellent image characteristics can be produced.

  Hereinafter, the present invention will be described in detail.

  FIG. 1 is an example of a cross-sectional view of a suitable polymerization vessel used in the present invention, but is not limited thereto. The present invention is used in various polymerization toner production methods including suspension polymerization and emulsion aggregation, and is preferably used in suspension polymerization.

  In FIG. 1, 1 is a polymerization vessel, 2 is a stirring device, 3 is a baffle, 4 is a drive device, 5 is a gas-liquid interface, and 6 is a jacket for temperature control.

  It is preferable that the poorly water-soluble inorganic compound is present on the inner wall of the polymerization vessel by contacting and drying the liquid (liquid B) containing the poorly water-soluble inorganic compound on the inner wall surface of the polymerization vessel 1. Thereby, the poorly water-soluble inorganic compound adheres firmly to the inner wall of the polymerization vessel. A polymerizable monomer composition dispersion is introduced into a polymerization vessel in which a poorly water-soluble inorganic compound is present on the surface. Adhesion of the polymer scale to the inner wall of the polymerization vessel due to repulsion between the inorganic dispersion stabilizer covering the droplets of the polymerizable monomer composition and the inner wall of the polymerization vessel and / or the poorly water-soluble inorganic compound on the surface of the accessory device Can be suppressed. Moreover, the adhesion of the scale to the surface of the auxiliary equipment in the polymerization vessel can be suppressed by performing the same treatment on the surface of the auxiliary equipment such as the stirring device 2 and the baffle 3.

  Simply contacting the poorly water-soluble inorganic compound directly to the inner wall of the polymerization vessel is not preferable because of poor adhesion to the inner wall of the polymerization vessel and easy peeling. For this reason, sufficient adhesion suppression effect is not acquired.

  The liquid component of the liquid B is not particularly limited as long as the hardly water-soluble inorganic compound is insoluble and has volatility. For example, water; methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, i Alcohols such as butyl alcohol and t-butyl alcohol can be used. Furthermore, organic solvents, such as acetone, methyl acetate, ethyl acetate, dimethyl sulfoxide, n-hexane, toluene, xylene, can be mentioned. Moreover, these can also be used individually or in combination of 2 or more types. Among those exemplified above, use of water alone or in combination with alcohols is preferable from the industrial and economic viewpoints.

  In the polymerization method, droplet formation of a polymerizable monomer composition and a polymerization reaction are performed in water or an aqueous medium mainly composed of water. A dispersion stabilizer is used to stabilize the dispersion. That is, in a method for producing toner particles by a polymerization method, generally, a polymerizable monomer composition is dispersed into fine droplets in an aqueous medium containing a dispersion stabilizer, and then polymerization is performed. The dispersion stabilizer adheres to the droplet surface of the polymerizable monomer composition, and enhances the dispersion stability of the droplet during droplet formation and polymerization. Dispersants are generally classified into water-soluble polymers that form a protective colloid layer to develop a repulsive force due to steric hindrance and poorly water-soluble inorganic compounds that develop a static repulsive force to stabilize dispersion. Separated.

  As water-soluble polymers, for example, polyvinyl alcohol, methylcellulose, and gelatin are known.

  Examples of the hardly water-soluble inorganic compounds include, for example, carbonates such as barium sulfate, calcium sulfate, barium carbonate, calcium carbonate, and magnesium carbonate; phosphoric acids such as aluminum phosphate, magnesium phosphate, calcium phosphate, barium phosphate, and zinc phosphate Polyvalent metal salts; inorganic salts such as calcium metasuccinate, calcium sulfate and barium sulfate; inorganic oxides such as silica, bentonite and alumina; inorganics such as calcium hydroxide, aluminum hydroxide, magnesium hydroxide and ferric hydroxide A hydroxide; and the like. These poorly water-soluble inorganic compounds can be used alone or in combination of two or more. Since many of these poorly water-soluble inorganic compounds are metal compounds, they may be referred to as poorly water-soluble metal compounds. These poorly water-soluble inorganic compounds exhibit a function as a dispersion stabilizer when present as fine particles in an aqueous medium. As the fine particles of the hardly water-soluble inorganic compound, it is desirable to use a substance that dissolves by making the liquid property acid or alkali. By dissolving with an acid or alkali, it can be dissolved and removed by washing with an acid or alkali after the polymerization, so that toner particles having excellent image characteristics can be obtained.

  Among these poorly water-soluble inorganic compounds, poorly water-soluble metal phosphates such as aluminum phosphate, magnesium phosphate, calcium phosphate, barium phosphate and zinc phosphate are preferably used. Furthermore, alkaline earth metal phosphates such as calcium phosphate are preferred.

  In the present invention, the hardly water-soluble inorganic compound used as the dispersion stabilizer is used as the poorly water-soluble inorganic compound used in the liquid B to be dried by contacting with the inner wall of the polymerization vessel. These poorly water-soluble inorganic compounds may be used alone or in combination of two or more. Among them, metal phosphates such as aluminum phosphate, magnesium phosphate, calcium phosphate, barium phosphate, and zinc phosphate are preferably used, and alkaline earth metal phosphates such as calcium phosphate are more preferable.

  Although the slightly water-soluble inorganic compound as the inorganic dispersion stabilizer and the slightly water-soluble inorganic compound contained in the liquid B may be different from each other, from the viewpoint of simplifying the process of removing the dispersion stabilizer after polymerization. It is preferable to use a combination of those soluble in acid or alkali. Furthermore, it is preferable to use a hardly water-soluble inorganic compound having the same composition.

  The dispersion stabilizer used in the granulation step in which the polymerizable monomer composition is performed in an aqueous dispersion medium is preferably an inorganic dispersion stabilizer. Electrostatic repulsion due to the inorganic dispersion stabilizer that collects in the dispersed droplets of the polymerizable monomer composition and the poorly water-soluble inorganic compound that adheres to the inner wall of the polymerization vessel suppresses the adhesion of the dispersed droplets to the inner wall of the polymerization vessel. The Thereby, a scale can be suppressed effectively.

  When a water-soluble polymer is used as a dispersion stabilizer, a sufficient repulsive force is not generated between the dispersed droplets and the polymerization vessel, so that the effect of preventing adhesion of the polymer scale is not satisfactory.

  It is preferable to uniformly and efficiently contact the liquid B containing the poorly water-soluble inorganic compound with the inner wall of the polymerization vessel. Moreover, the liquid B can suppress adhesion of the polymer scale to the surface of an incidental device by contacting and drying the surface of the incidental device in the polymerization container.

  As an example of a preferable method for contacting the liquid B, a method of spraying the liquid B on the inner wall of the polymerization vessel may be mentioned. The spraying method will be described with reference to FIG. FIG. 2 is an example of a cross-sectional view of a preferred polymerization apparatus used in the present invention provided with a shower nozzle for spraying liquid B containing a poorly water-soluble inorganic dispersant. In FIG. 2, 1 is a polymerization vessel, 2 is a stirring device, 3 is a baffle, 4 is a drive device, 6 is a jacket for temperature control, and 7 is a shower nozzle. Liquid B is sprayed from the shower nozzle toward the inner wall of the polymerization vessel. In FIG. 2, the shower is sprayed toward the upper part of the polymerization vessel, but the direction of the shower may be changed to an arbitrary direction. If it is a direction shown in FIG. 2, the liquid B spread | dispersed on the superposition | polymerization container upper part will contact | connect the superposition | polymerization container inner wall and the incidental device surface in a superposition | polymerization container which are side surfaces. At this time, the stirring device 2 may be rotated.

As an example of a preferable method for contacting the liquid B, there is a method in which the inside of the polymerization vessel is immersed in the liquid B and then discharged. The liquid B preferably fills the inside of the polymerization vessel, but the volume V _b (l) of the liquid B is 1.10 V <V _b with respect to the volume V (l) of the polymerizable monomer composition dispersion. It is preferable to become. If the above relationship is satisfied, the polymer scale adheres to the polymer scale because the polymerizable monomer composition dispersion in the polymerization step is in contact with the inner wall of the polymerization vessel and there is a hardly water-soluble inorganic compound near the gas-liquid interface. Can be well controlled. In addition, the liquid B containing the hardly water-soluble inorganic compound may be prepared in advance and immersed in the polymerization vessel or may be prepared in the polymerization vessel.

  It is preferable to heat the inner wall of the polymerization vessel and dry the liquid (liquid B) containing the hardly water-soluble inorganic compound. There is no restriction | limiting in particular as a heating method, Blowing of the heating air in a superposition | polymerization container, heating a superposition | polymerization container inner wall indirectly with an external jacket, etc. are mentioned. By applying heat and drying, the poorly water-soluble inorganic compound adheres more firmly to the inner wall of the polymerization vessel. For this reason, peeling of a hardly water-soluble inorganic compound hardly occurs, and scale adhesion can be further prevented.

  Furthermore, the heating temperature is preferably in the range of 40.0 ° C. or higher and 80.0 ° C. or lower. The inner wall of the polymerization vessel and the liquid B may be heated in advance.

  When the heating temperature is lower than 40.0 ° C., not only is the non-uniform fixation of the poorly water-soluble inorganic compound on the surface of the polymerization vessel after drying undesirably, but the drying time becomes longer and the production efficiency is impaired.

  When the heating temperature exceeds 80.0 ° C., the drying rate is too fast, so that the hardly water-soluble inorganic compound is not sufficiently fixed, and it is easy to peel off during the polymerization process, which is not preferable.

The concentration of the hardly water-soluble inorganic compound and the concentration C _a of the dispersion stabilizer (weight%), for a liquid (liquid B) containing a poorly water-soluble inorganic compound to the dispersion stabilizer aqueous dispersion medium containing a (liquid A) C _b ( % By mass) preferably satisfies the relationship of 1.0C _a ≦ C _b ≦ 40.0C _a . Furthermore, it is preferable to satisfy the relationship of _{1.2C a ≦ C b ≦ 32.0C a} .

If the concentration of the hardly water-soluble inorganic compound to liquid B C _b (mass%) of 1.0 C _a smaller repulsive force between the dispersion stabilizer covers the periphery of the dispersed droplets of the polymerizable monomer composition is reduced It is difficult to obtain a sufficient effect. When the concentration C _b (mass%) is larger than 40.0C _a , a part of the hardly water-soluble inorganic compound on the inner wall of the polymerization vessel moves into the polymerizable monomer composition dispersion liquid or in the vicinity of the dispersed droplets in the subsequent process. This is not preferable because it increases the load of the. Furthermore, the image properties of the resulting toner particles may be adversely affected, such as changing the physical properties of the polymerizable monomer composition dispersion.

It is preferred that the hardly water-soluble inorganic compound to the polymerization vessel inner wall surface is present at a density of 0.05 mg / cm ² or more 7.50mg / cm ² or less. When it is less than 0.05 mg / cm ² , a part in which the hardly water-soluble inorganic compound does not exist is generated. Moreover, the electrostatic repulsive force with respect to the droplet of the polymerizable monomer composition of a poorly water-soluble inorganic compound is reduced. For these reasons, the scale adhesion suppressing effect is reduced, which is not preferable. If it is greater than 7.50 mg / cm ² , cracks occur in the layer of the hardly water-soluble inorganic compound, and the layer of the hardly water-soluble inorganic compound increases in thickness, so that it is easy to peel off due to the flow of the polymerizable monomer composition dispersion. Become. Further, the heat transfer efficiency of the polymerization vessel is lowered by the layer of the hardly water-soluble inorganic compound. These effects are not preferable because scale adhesion partially occurs and developability of toner particles is adversely affected.

  The method for producing toner particles of the present invention can be preferably used not only for producing non-magnetic toner particles but also for producing magnetic toner particles.

  It is preferable that the surface of the magnetic material used when producing the magnetic toner by the suspension polymerization method is hydrophobized. When hydrophobizing the magnetic material, it is very preferable to use a method in which the surface treatment is carried out while hydrolyzing the coupling agent while dispersing the magnetic material particles as primary particles in an aqueous medium. In this hydrophobization method, the magnetic particles are less likely to coalesce than in the gas phase, and the magnetic repulsion action between the magnetic particles due to the hydrophobization treatment works, so the magnetic material is almost in the state of primary particles. Surface treatment with.

  The method of treating the surface of the magnetic material while hydrolyzing the coupling agent in an aqueous medium does not require the use of a coupling agent that generates gas, such as chlorosilanes and silazanes. In addition, since the magnetic particles can be easily united in the gas phase so far, it is possible to use a highly viscous coupling agent that has been difficult to perform well, so the effect of hydrophobization is tremendous. It is.

Examples of the coupling agent that can be used in the surface treatment of the magnetic material according to the present invention include a silane coupling agent and a titanium coupling agent. Among them, a silane coupling agent is more preferably used, and has the following general formula R _m SiY _n
[Wherein, R represents an alkoxy group, m represents an integer of 1 to 3, Y represents a functional group such as an alkyl group, a vinyl group, a glycidoxy group, or a methacryl group, and n represents an integer of 1 to 3] . ]
It is shown by.

  For example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxy Propylmethyldiethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyl Trimethoxysilane, diphenyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, n-butyltrimethoxysilane, Butyl trimethoxy silane, trimethyl silane, hydroxypropyl trimethoxysilane, n- hexadecyl trimethoxy silane, can be mentioned n- octadecyl trimethoxysilane.

Among them, it is more preferable to use an alkyltrialkoxysilane coupling agent represented by the following formula in combination in order to obtain sufficient hydrophobicity.
C _p H _{2p + 1} -Si- (OC _q H _2q +1) ₃
[Wherein, p represents an integer of 2 to 20, and q represents an integer of 1 to 3]

  In the above formula, when p is smaller than 2, the hydrophobization treatment is easy, but it is difficult to sufficiently impart hydrophobicity, and it becomes difficult to suppress the exposure of the magnetic particles to the particle surface. On the other hand, when p is larger than 20, the hydrophobicity is sufficient, but the coalescence between the magnetic particles increases, and it becomes difficult to sufficiently disperse the magnetic particles in the toner particles, and the particle size distribution of the toner is reduced. It feels broad. On the other hand, when q is larger than 3, the reactivity of the silane coupling agent is lowered and the hydrophobicity is not sufficiently performed.

  More preferably, an alkyltrialkoxysilane coupling agent in which p is an integer of 3 to 15 and q is 1 or 2 in the above formula is used.

  The treatment amount is 0.05 parts by mass or more and 20 parts by mass or less, preferably 0.1 parts by mass or more and 10 parts by mass or less of the silane coupling agent with respect to 100 parts by mass of the magnetic substance. It is preferable to adjust the amount of the treatment agent according to the surface area and the reactivity of the coupling agent.

  Moreover, the aqueous medium used at the time of the hydrophobic treatment is a medium containing water as a main component. Specific examples of the aqueous medium include water itself, water added with a small amount of a surfactant, water added with a pH adjusting agent, and water added with an organic solvent. As the surfactant, a nonionic surfactant such as polyvinyl alcohol is preferable. The surfactant is preferably added in an amount of 0.1% by mass to 5% by mass with respect to water. Examples of the pH adjuster include inorganic acids such as hydrochloric acid, and examples of the organic solvent include alcohols.

  In addition, when using a multiple types of silane coupling agent, a multiple types of coupling agent can be thrown in simultaneously or with a time difference, and a magnetic body can be processed.

  In the magnetic material thus obtained, particle aggregation is suppressed and the surface of each particle is uniformly hydrophobized, so that the dispersibility of the magnetic material in the polymerizable monomer is good.

The magnetic body is composed mainly of iron oxide such as triiron tetroxide and γ-iron oxide, and may contain elements such as phosphorus, cobalt, nickel, copper, magnesium, manganese, aluminum, and silicon. These magnetic materials preferably have a BET specific surface area of 2 m ² / g or more and 30 m ² / g or less, more preferably 3 m ² / g or more and 28 m ² / g or less by a nitrogen adsorption method. Further, those having a Mohs hardness of 5 to 7 are preferred.

  For example, in the case of the suspension polymerization method, the magnetic material used for the toner is preferably 10 parts by mass or more and 200 parts by mass or less with respect to 100 parts by mass of the binder resin. More preferably, 20 parts by mass or more and 180 parts by mass or less are used. If it is less than 10 parts by mass, the coloring power of the toner is poor, and it is difficult to suppress fogging. On the other hand, when the amount exceeds 200 parts by mass, not only is it difficult to uniformly disperse the magnetic material into individual toner particles, but also the retention of the obtained toner on the toner carrier increases due to the magnetic force, resulting in a decrease in developability. , The fixing property is lowered.

  The content of the magnetic substance in the toner is measured with a thermal analyzer, TGA7, manufactured by PerkinElmer. In the measurement method, the toner is heated from normal temperature to 900 ° C. at a temperature increase rate of 25 ° C./min in a nitrogen atmosphere, and the weight loss from 100 ° C. to 750 ° C. is defined as the binder resin amount, and the remaining mass is approximated. The amount of magnetic material.

  For example, in the case of magnetite, the magnetic material used in the magnetic toner according to the present invention can be produced by the following method. An aqueous solution containing ferrous hydroxide is prepared by adding an alkali such as sodium hydroxide in an amount equivalent to or higher than the iron component to the ferrous salt aqueous solution. Air was blown in while maintaining the pH of the prepared aqueous solution at 7 or more (preferably pH 8 to 14), and iron oxide was oxidized while heating the aqueous solution to 70 ° C. First, a seed crystal is formed.

  Next, an aqueous solution containing about 1 equivalent of ferrous sulfate is added to the slurry-like liquid containing seed crystals based on the amount of alkali added previously. While maintaining the pH of the solution at 6 to 14, the reaction of ferrous hydroxide proceeds while blowing air to grow magnetic iron oxide particles with the seed crystal as the core. As the oxidation reaction proceeds, the pH of the liquid shifts to the acidic side, but the pH of the liquid is preferably not less than 6. Adjust the pH of the solution at the end of the oxidation reaction, stir well so that the magnetic iron oxide becomes primary particles, add the coupling agent, stir well, stir, filter, dry, and lightly crush after stirring By doing so, hydrophobic treated magnetic iron oxide particles can be obtained. Alternatively, after the oxidation reaction is completed, the iron oxide particles obtained by washing and filtering are redispersed in another aqueous medium without drying, and then the pH of the redispersion is adjusted and the silane is stirred well. A coupling agent may be added to perform the coupling treatment. In any case, it is preferable to perform the coupling agent treatment after the oxidation reaction without passing through the drying step.

  As the ferrous salt, iron sulfate generally produced as a by-product in the production of sulfuric acid titanium, iron sulfate produced as a by-product with the surface cleaning of the steel sheet can be used, and iron chloride or the like can be used.

  In the production method of magnetic iron oxide by the aqueous solution method, when iron sulfate is used, the aqueous solution generally has an iron concentration of 0.5 mol / l or more and 2.0 mol / l from the viewpoint of preventing the viscosity from increasing during the reaction and the solubility of iron sulfate. The following are used. Generally, the lower the iron sulfate concentration, the finer the particle size of the product. Further, in the reaction, the more the amount of air is and the lower the reaction temperature is, the easier it is to atomize.

  By using the magnetic toner made of the hydrophobic magnetic particles produced as described above, stable toner charging property can be obtained, transfer efficiency is high, and high image quality and high stability are possible.

  The magnetic material obtained as described above can be suitably used as a colorant contained in the toner particles. However, the magnetic material other than the magnetic material that can be suitably used for the toner produced in the present invention. Examples of the agent include carbon black and the following yellow / magenta / cyan colorants.

  As a colorant suitable for the yellow color, a pigment or a dye can be used. Specifically, examples of the pigment include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 17, 23, 62, 65, 73, 74, 81, 83, 93, 94, 95, 97, 98, 109, 110, 111, 117, 120, 127, 128, 129, 137, 138, 139, 147, 151, 154, 155, 167, 168, 173, 174, 176, 180, 181, 183, 191 and C.I. I. Bat yellow 1, 3, 20, etc. Examples of the dye include C.I. I. Solvent yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162 etc. are mentioned. These may be used alone or in combination.

  As a colorant suitable for magenta, a pigment or a dye can be used. Specifically, examples of the pigment include C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48, 48: 2, 48: 3, 48: 4, 49, 50, 51, 52, 53, 54, 55, 57, 57: 1, 58, 60, 63, 64, 68, 81, 81: 1, 83, 87, 88, 89, 90, 112, 114, 122, 123, 144, 146, 150, 163, 166, 169, 177, 184, 185, 202, 206, 207, 209, 220, 221, 238, 254, etc., C.I. I. Pigment violet 19; C.I. I. Vat Red 1, 2, 10, 13, 15, 23, 29, 35, etc. Examples of the dye include C.I. I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 52, 58, 63, 81, 82, 83, 84, 100, 109, 111, 121, 122, etc. I. Disper thread 9, C.I. I. Solvent Violet 8, 13, 14, 21, 27 etc., C.I. I. Oil-soluble dyes such as disperse violet 1, C.I. I. Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, 40, etc. I. Basic violet 1,3,7,10,14,15,21,25,26,27,28 etc. basic dyes etc. are mentioned. These may be used alone or in combination.

  As a colorant suitable for cyan, a pigment or a dye can be used. Specifically, examples of the pigment include C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 16, 17, 60, 62, 66, etc., C.I. I. Bat Blue 6, C.I. I. Acid Blue 45. Examples of the dye include C.I. I. Solvent Blue 25, 36, 60, 70, 93, 95 etc. are mentioned. These may be used alone or in combination.

  These colorants can be used singly or in combination of two or more, or can be used in the form of a solid solution. The colorant of the present invention is selected from the viewpoints of hue angle, saturation, lightness, weather resistance, OHP transparency, and dispersibility in toner particles. The amount of the colorant added is preferably 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the binder resin.

  The toner particles may contain a release agent. Examples of the release agent include petroleum wax such as paraffin wax, microcrystalline wax, and petrolatum and derivatives thereof, montan wax and derivatives thereof, hydrocarbon wax and derivatives thereof according to the Fischer-Tropsch method, polyolefin waxes represented by polyethylene, and the like. Derivatives thereof, natural waxes such as carnauba wax and candelilla wax, and derivatives thereof, which include oxides, block copolymers with vinyl monomers, and graft modified products. Furthermore, fatty acids such as higher aliphatic alcohols, stearic acid and palmitic acid, or compounds thereof, acid amide waxes, ester waxes, ketones, hydrogenated castor oil and derivatives thereof, plant waxes, animal waxes and the like can also be used.

  Specific examples of the wax that can be used as a release agent include Biscol (registered trademark) 330-P, 550-P, 660-P, TS-200 (Sanyo Chemical Industries); high wax 400P, 200P, 100P, 410P, 420P, 320P, 220P, 210P, 110P (Mitsui Chemicals); Sazol H1, H2, C80, C105, C77 (Schumann Sazol); HNP-1, HNP-3, HNP-9, HNP-10, HNP-11, HNP-12 (Nippon Seiki Co., Ltd.); Unilin (registered trademark) 350, 425, 550, 700, Unicid (registered trademark) 350, 425, 550, 700 (Toyo Petrolite Co., Ltd.); Beeswax, rice wax, candelilla wax, carnauba wax (available at Celerica NODA) And the like.

  A charge control agent may be blended in the toner particles. A well-known thing can be utilized as a charge control agent. Further, for example, in the case of a wet granulation method using a suspension polymerization method, when producing toner particles, a charge control agent having a low polymerization inhibitory property and substantially free from a solubilized product in an aqueous dispersion medium is particularly preferable. Specific compounds include, as negative charge control agents, metal compounds of aromatic carboxylic acids such as salicylic acid, alkylsalicylic acid, dialkylsalicylic acid, naphthoic acid, dicarboxylic acid, metal salts or metal complexes of azo dyes or azo pigments, sulfones Examples thereof include a polymer compound having an acid or carboxylic acid group in the side chain, a boron compound, a urea compound, a silicon compound, and a calixarene. Examples of the positive charge control agent include quaternary ammonium salts, polymer compounds having the quaternary ammonium salt in the side chain, guanidine compounds, nigrosine compounds, and imidazole compounds.

  As a method for adding the charge control agent to the toner particles, there are a method of adding the charge control agent inside the toner particles and a method of adding the charge control agent externally to the toner particles. The amount of these charge control agents used is determined by the toner production method including the type of binder resin, the presence or absence of other additives, and the dispersion method, and is not uniquely limited. When added internally, it is preferably used in the range of 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the binder resin. When added externally, the amount is preferably 0.005 parts by mass or more and 1.0 parts by mass or less, more preferably 0.01 parts by mass or more and 0.3 parts by mass or less, with respect to 100 parts by mass of the toner particles.

  In the present invention, for example, in the case of emulsion polymerization or suspension polymerization, examples of the polymerizable monomer used include the following. Styrene monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-ethylstyrene; methyl acrylate, ethyl acrylate, n-butyl acrylate, acrylic acid Acrylic esters such as isobutyl, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, and phenyl acrylate; methyl methacrylate, methacrylic acid Ethyl, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethyl methacrylate Aminoethyl, methacrylic acid esters such as diethylaminoethyl methacrylate; and other acrylonitrile, methacrylonitrile, and the like monomers acrylamide.

  In the case of the emulsion polymerization method or suspension polymerization method, polymerization may be carried out by adding a resin (polymer) to the polymerizable monomer. Resins containing hydrophilic functional groups such as amino groups, carboxylic acid groups, hydroxyl groups, sulfonic acid groups, glycidyl groups, and nitrile groups that cannot be used because monomers are water-soluble and dissolve in aqueous suspension to cause emulsion polymerization. In the toner particles, a random copolymer of these monomers having a functional group and a vinyl compound such as styrene or ethylene, a block copolymer, or a copolymer such as a graft copolymer. Or in the form of a polycondensate such as polyester or polyamide, or in the form of a polyaddition polymer such as polyether or polyimine.

In the present invention, alcohol components and acid components used for obtaining a polyester resin used by adding to the polymerizable monomer are exemplified below. As alcohol components, ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexane Diol, neopentyl glycol, 2-ethyl-1,3-hexanediol, cyclohexanedimethanol, butenediol, octenediol, cyclohexenedimethanol, hydrogenated bisphenol A, a bisphenol derivative represented by formula (I) or the formula (I Hydrogenated compound represented by:
H (OR) _x OPhC (CH ₃ ) ₂ PhO (RO) _y H (I)
[Wherein, R represents an ethylene group or a propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2 to 10. ]

Alternatively, a diol represented by the following formula (II) or a hydrogenated product of the compound represented by the formula (II) can be used.
HOR'OPhOR'OH (II)
[Wherein R ′ is CH ₂ CH ₂ , CH ₂ CHCH ₃ , CH ₂ C (CH ₃ ) ₂ ]

  As the divalent carboxylic acid as the acid component, benzene dicarboxylic acid such as phthalic acid, terephthalic acid, isophthalic acid, phthalic anhydride or an anhydride thereof; alkyl dicarboxylic acid such as succinic acid, adipic acid, sebacic acid, azelaic acid, or Succinic acid or anhydride thereof substituted with an alkyl or alkenyl group having 6 to 18 carbon atoms; unsaturated dicarboxylic acids such as fumaric acid, maleic acid, citraconic acid, itaconic acid or anhydrides thereof; Can be mentioned.

  Furthermore, polyhydric alcohols such as glycerin, pentaerythritol, sorbit, sorbitan, and oxyalkylene ethers of novolac type phenol resins can be cited as the alcohol component, and trimellitic acid, pyromellitic acid, 1,2,3,4- Examples thereof include polyvalent carboxylic acids such as butanetetracarboxylic acid, benzophenonetetracarboxylic acid and anhydrides thereof.

  It is preferable that 45 mol% or more and 55 mol% or less of the polyester resin is an alcohol component, and 55 mol% or less and 45 mol% or more is an acid component. In the present invention, two or more kinds of polyester resins may be used in combination as long as the physical properties of the obtained toner particles are not adversely affected, or modified with, for example, silicone or a fluoroalkyl group-containing compound to adjust the physical properties. Is also preferably performed. Moreover, when using resin containing such a polar functional group, the average molecular weight has preferable 5,000 or more.

  In addition, resins other than those mentioned above may be added to the monomer system. Examples of the resin used include styrene such as polystyrene and polyvinyltoluene, and homopolymers of substitution products thereof; styrene-propylene copolymer, styrene -Vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer Styrene-dimethylaminoethyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, Styrene-vinyl methyl ether copolymer, styrene Nyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer, etc. Copolymer: Polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyester resin, polyamide resin, epoxy resin, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenol resin Aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins and the like can be used alone or in combination.

  As addition amount of these resin, 1 to 20 mass parts is preferable with respect to 100 mass parts of monomers. If the amount is less than 1 part by mass, the effect of addition is small. On the other hand, if the amount added is more than 20 parts by mass, it becomes difficult to design various physical properties of the polymerized toner.

  Further, a polymer having a molecular weight different from the molecular weight range of the toner particles obtained by polymerizing the monomer may be dissolved in the monomer for polymerization.

  In the method for producing toner particles of the present invention, when a polymerization initiator is used for initiating the polymerization reaction of the polymerizable monomer, the one having a half-life of 0.5 hours to 30 hours at the time of the polymerization reaction, When a polymerization reaction is carried out with an addition amount of 0.5 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer, a polymer having a maximum between 10,000 and 100,000 can be obtained. The toner can be provided with the desired strength and suitable melting characteristics. As polymerization initiators, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), Azo or diazo polymerization initiators such as 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene Examples thereof include peroxide polymerization initiators such as hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, t-butylperoxy 2-ethylhexanoate, and t-butylperoxypivalate.

  When the toner is produced, a crosslinking agent may be added, and a preferable addition amount is 0.001 part by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer.

  Here, as the cross-linking agent, a compound having two or more polymerizable double bonds is mainly used. For example, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; carboxylic acid esters having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, and the like; Divinyl aniline, divinyl ether, divinyl sulfide, divinyl sulfone and other divinyl compounds; and compounds having three or more vinyl groups are used alone or as a mixture of two or more.

  For example, a specific toner manufacturing method when the suspension polymerization method is selected will be described.

  First, the components necessary for the toner such as a colorant, a release agent, a plasticizer, a charge control agent, a crosslinking agent, and other additives in the polymerizable monomer, for example, the viscosity of the polymer produced by the polymerization reaction is reduced. For this purpose, an organic solvent, a resin component (polymer), a dispersing agent and the like are added as appropriate, and uniformly dissolved or dispersed to obtain a colorant-containing polymerizable monomer composition. At this time, you may perform temperature control operation as needed. This colorant-containing polymerizable monomer composition is dispersed in an aqueous medium containing a dispersion stabilizer, suspended and granulated.

  At this time, the colorant-containing polymerizable monomer composition is granulated, or at the same time after granulation, the composition is polymerized (polymerization step).

  The specific timing of addition of the polymerization initiator may be added simultaneously with the addition of other additives to the polymerizable monomer, or the colorant-containing polymerizable monomer composition may be added to the aqueous medium. It may be added and mixed immediately before suspending. Moreover, when starting superposition | polymerization after granulation, as mentioned above, it can add after granulation. Further, an additional polymerizable monomer or a polymerization initiator dissolved in a solvent can be added during the polymerization reaction.

  After granulation, stirring may be performed to such an extent that the particle state is maintained and the particles are prevented from staying and settling using a normal stirrer while adjusting the temperature.

  In the case of producing toner particles, a known surfactant or an organic / inorganic dispersant as described above can be used as a dispersion stabilizer. Of these, inorganic dispersants are preferred because they are less likely to produce ultrafine powders that adversely affect toner performance, and stability is not easily lost even when the reaction temperature is changed. Examples of such inorganic dispersion stabilizers include the aforementioned poorly water-soluble inorganic compounds.

  These inorganic dispersion stabilizers are preferably used alone in an amount of 0.2 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer. Moreover, you may use together 0.001 mass part or more and 0.1 mass part or less surfactant.

  Examples of the surfactant include sodium dodecylbenzenesulfonate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, sodium stearate, potassium stearate and the like.

  When using the above-mentioned inorganic dispersant, commercially available ones may be used as they are, but in order to obtain finer particles, the inorganic dispersant particles can be generated and used in an aqueous medium. For example, in the case of calcium phosphate, a sodium phosphate aqueous solution and a calcium chloride aqueous solution can be mixed with high-speed stirring to produce water-insoluble calcium phosphate, which enables more uniform and fine dispersion. At this time, water-soluble sodium chloride salt is by-produced at the same time. However, when water-soluble salt is present in the aqueous medium, dissolution of the polymerizable monomer in water is suppressed, and ultrafine toner particles based on emulsion polymerization are used. This is more convenient because it becomes difficult to occur. The inorganic dispersant can be dissolved with an acid or an alkali after the completion of the polymerization and removed almost completely by the next step such as filtration and washing.

  In the polymerization step, the polymerization is performed at a polymerization temperature of 40 ° C. or higher, generally 50 ° C. or higher and 90 ° C. or lower. When the polymerization is carried out in this temperature range, the release agent and wax to be sealed inside the toner particles are precipitated by phase separation, and the encapsulation becomes more complete. In order to consume the remaining polymerizable monomer, the reaction temperature may be raised to 90 ° C. or higher and 150 ° C. or lower at the end of the polymerization reaction. After completion of the polymerization reaction, the obtained toner particle dispersion is filtered and washed, and then preferably dried by an air flow drying device.

  In general, coarse particles and fine particles outside the desired particle size range are removed from the obtained toner particles in the classification step. The classification step can be carried out by a known method used in conventional toner production, and is not particularly limited. A toner can be obtained by mixing an external additive such as an inorganic fine powder with the toner particles obtained through the classification step and adhering them to the surface of the toner particles.

  In the present invention, it is one of desirable modes to directly obtain the toner by omitting the classification process from the manufacturing process or to cut coarse powder and fine powder with high precision by performing a more accurate classification process.

  In the present invention, it is preferable to add a fluidity imparting agent as an external additive to the toner particles. Preferable fluidity-imparting agents include inorganic fine particles having a number average primary particle size of 4 nm to 80 nm.

As the inorganic fine particles, fine particles such as silica, alumina, and titanium oxide can be used. For example, as the silica fine particles, both a so-called dry method produced by vapor phase oxidation of silicon halide or dry silica called fumed silica, and so-called wet silica produced from water glass or the like can be used. , fewer silanol groups on the inner surface and the silica fine particles and Na ₂ O, SO ₃ ^- it is preferable less dry silica of manufacturing residue such. In dry silica, it is also possible to obtain composite fine powders of silica and other metal oxides by using other metal halogen compounds such as aluminum chloride and titanium chloride together with silicon halogen compounds in the production process, They are also included.

  The addition amount of the inorganic fine particles is preferably 0.1% by mass or more and 3.0% by mass or less with respect to the toner particles. If the addition amount is less than 0.1% by mass, the effect is not sufficient, and if it is more than 3.0% by mass, the fixability may be lowered. The content of the inorganic fine particles can be quantified using a calibration curve prepared from a standard sample using fluorescent X-ray analysis.

  The inorganic fine particles are preferably hydrophobized in view of characteristics in a high temperature and high humidity environment. As treatment agents for hydrophobizing treatment, treatment agents such as silicone varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, silane compounds, silane coupling agents, other organic silicon compounds, and organic titanium compounds are used alone. Or may be used in combination.

  As a method for treating the inorganic fine particles, for example, a method of forming a hydrophobic thin film on the surface with silicone oil as a second-stage reaction after performing a silylation reaction as a first-stage reaction to eliminate silanol groups by chemical bonding. Can be mentioned.

The silicone oil may have a viscosity less of 10 mm ² / s or more 200,000 mm ² / s at 25 ° C., and more preferably the following 3,000 mm ² / s or more 80,000mm ² / s. If it is less than 10 mm ² / s, the inorganic fine particles are not stable, and the image quality tends to deteriorate due to heat and mechanical stress. If it exceeds 200,000 mm ² / s, uniform processing tends to be difficult.

  As the silicone oil used, for example, dimethyl silicone oil, methylphenyl silicone oil, α-methylstyrene modified silicone oil, chlorophenyl silicone oil, fluorine modified silicone oil and the like are particularly preferable.

  As a method for treating inorganic fine particles with silicone oil, for example, inorganic fine particles treated with a silane compound and silicone oil may be directly mixed using a mixer such as a Henschel mixer, or silicone oil may be sprayed onto the inorganic fine particles. You may use the method to do. Alternatively, after dissolving or dispersing silicone oil in a suitable solvent, inorganic fine particles may be added and mixed to remove the solvent. A method using a sprayer is more preferable in that the formation of inorganic fine particle aggregates is relatively small.

  The treatment amount of the silicone oil is 1 to 40 parts by mass, preferably 3 to 35 parts by mass with respect to 100 parts by mass of the inorganic fine particles.

In the case of using the silica fine particles in order to impart good fluidity to the toner, the specific surface area measured by the BET method by nitrogen adsorption of preferably those in the range of 20 to 350m ² / g, 25 to 300 meters ² / g is more preferable.

  In accordance with the BET method, the specific surface area is obtained by adsorbing nitrogen gas to the sample surface using a specific surface area measuring device Autosorb 1 (manufactured by Yuasa Ionics) and calculating the specific surface area using the BET multipoint method.

For the purpose of improving the cleaning property, it is also preferable to add inorganic or organic spherical fine particles having a primary particle size exceeding 30 nm (more preferably, the primary particle size is 50 nm or more) as an external additive to the toner particles. One of the forms. As the inorganic or organic fine particles, those having a specific surface area of less than 50 m ² / g (more preferably a specific surface area of less than 30 m ² / g) can be preferably used. As such fine particles, for example, spherical silica particles, spherical polymethylsilsesquioxane particles, spherical resin particles and the like are preferably used.

  Other external additives may be added to the toner particles and used within a range that does not substantially adversely affect the toner. For example, lubricant powder such as polyfluorinated ethylene powder, zinc stearate powder, polyvinylidene fluoride powder; abrasive such as cerium oxide powder, silicon carbide powder, strontium titanate powder; imparting fluidity such as titanium oxide powder, aluminum oxide powder Agents; anti-caking agents and the like. In addition, a small amount of organic fine particles or inorganic fine particles having reverse polarity can be used as a developing property improver. These external additives can also be used after the surface is hydrophobized.

  The toner containing toner particles produced in the present invention can be used as a one-component developer or a two-component developer mixed with a magnetic carrier.

  The magnetic carrier is generated using an element selected from iron, copper, zinc, nickel, cobalt, manganese, and chromium alone or in a composite ferrite state. The magnetic carrier has a spherical shape, a flat shape, or an indeterminate shape. Furthermore, it is preferable to control the fine structure (for example, surface unevenness) of the surface state of the magnetic carrier particles. As a method for producing a carrier, a method is generally used in which the above-mentioned inorganic oxide is fired and granulated to previously produce magnetic carrier core particles, and then the carrier core particles are coated with a resin. For the purpose of reducing the load of the magnetic carrier on the toner, a method of obtaining a low density dispersion carrier by kneading and classifying an inorganic oxide and a resin, or a kneaded product of an inorganic oxide and a monomer directly in an aqueous medium It is also possible to use a method in which suspension polymerization is performed to obtain a true spherical magnetic carrier.

  Among these, a coated carrier obtained by coating the surface of the carrier core particle with a resin is particularly preferable. As a method of coating the surface of the carrier core particles with the resin, the resin is dissolved or suspended in a solvent and applied to the carrier core by coating, or the resin powder and the carrier core particles are mixed and attached. Can be applied.

  The coating material on the surface of the carrier particles varies depending on the toner material. For example, polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicone resin, polyester resin, styrene resin, acrylic resin, polyamide, polyvinyl butyral And aminoacrylate resins. These may be used alone or in plural.

The magnetic properties of the carrier are as follows. The magnetization strength (σ1000) at a magnetic field strength of 79.6 kA / m after magnetic saturation is preferably 3.77 μWb / cm ³ or more and 37.7 μWb / cm ³ or less. In order to achieve higher image quality, it is more preferably 12.6 μWb / cm ³ or more and 31.4 μWb / cm ³ or less. When the magnetization intensity is greater than 37.7 μWb / cm ^3, it becomes difficult to obtain a high-quality toner image. On the other hand, when it is less than 3.77 Wb / cm ³ , the magnetic binding force is also reduced, so that carrier adhesion is likely to occur.

  When a two-component developer is prepared by mixing the toner used in the present invention with a magnetic carrier, the mixing ratio is such that the toner concentration in the developer is 2% by mass or more and 15% by mass or less, preferably 4% by mass or more and 13%. Good results are usually obtained when the content is less than or equal to mass%.

  An example of an image forming apparatus that can suitably use the toner of the present invention will be specifically described with reference to the drawings.

  In the image forming apparatus shown in FIG. 3, reference numeral 100 denotes a photosensitive drum, and a primary charging roller 117, a developing device 140, a transfer charging roller 114, a cleaner 116, a register roller 124, and the like are provided around the photosensitive drum. The photoreceptor 100 is charged to, for example, −700 V by the primary charging roller 117 (applied voltages are AC voltage −2.0 kVpp, DC voltage −700 Vdc). Then, exposure is performed by irradiating the photosensitive member 100 with a laser beam 123 by the laser generator 121. The electrostatic latent image on the photoconductor 100 is developed with a one-component magnetic developer by the developing device 140 and transferred onto the transfer material by the transfer charging roller 114 in contact with the photoconductor via the transfer material. The transfer material on which the toner image is placed is conveyed to the fixing device 126 by the conveying belt 125 or the like and fixed on the transfer material. In addition, toner partially remaining on the photoconductor is cleaned by a cleaner 116. As shown in FIG. 4, the developing device 140 is provided with a cylindrical toner carrier 102 (hereinafter referred to as a developing sleeve) made of a nonmagnetic metal such as aluminum or stainless steel in the vicinity of the photosensitive member 100. The gap between 100 and the developing sleeve 102 is maintained at about 300 μm by a sleeve / photoreceptor gap holding member (not shown). A magnet roller 104 is fixed and arranged concentrically with the developing sleeve 102 in the developing sleeve. However, the developing sleeve 102 is rotatable. The magnet roller 104 is provided with a plurality of magnetic poles as shown in the figure, and S1 influences development, N1 regulates the amount of toner coating, S2 takes in / conveys toner, and N2 affects toner blowout prevention. The toner is applied to the developing sleeve 102 by the toner application roller 141, and is adhered and conveyed. An elastic blade 103 is provided as a member for regulating the amount of toner conveyed, and the amount of toner conveyed to the development region is controlled by the contact pressure of the elastic blade 103 against the developing sleeve 102. In the developing region, a DC and AC developing bias is applied between the photosensitive member 100 and the developing sleeve 102, and the developer on the developing sleeve flies on the photosensitive member 100 in accordance with the electrostatic latent image and becomes a visible image. Become.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but these do not limit the present invention in any way.

  Each measurement method used in the present invention will be described below.

<Measuring method of weight average particle diameter (D4) and number average particle diameter (D1)>
The weight average particle diameter (D4) and number average particle diameter (D1) of the toner are calculated as follows. As a measuring device, a precise particle size distribution measuring device “Coulter Counter Multisizer 3” (registered trademark, manufactured by Beckman Coulter, Inc.) using a pore electrical resistance method equipped with a 100 μm aperture tube is used. For setting the measurement conditions and analyzing the measurement data, the attached dedicated software “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.) is used. Note that the measurement is performed with 25,000 effective measurement channels.

  As the electrolytic aqueous solution used for the measurement, special grade sodium chloride is dissolved in ion-exchanged water so as to have a concentration of about 1% by mass, for example, “ISOTON II” (manufactured by Beckman Coulter, Inc.) can be used.

  Prior to measurement and analysis, dedicated software was set up as follows.

  On the “Change Standard Measurement Method (SOM)” screen of the dedicated software, set the total count in the control mode to 50000 particles, set the number of measurements once, and set the Kd value to “standard particles 10.0 μm” (Beckman Coulter, Inc.) Set the value obtained using By pressing the “Threshold / Noise Level Measurement Button”, the threshold and noise level are automatically set. In addition, the current is set to 1600 μA, the gain is set to 2, the electrolyte is set to ISOTON II, and the “aperture tube flush after measurement” is checked.

  In the “Pulse to particle size conversion setting” screen of the dedicated software, the bin interval is set to logarithmic particle size, the particle size bin is set to 256 particle size bin, and the particle size range is set to 2 μm to 60 μm.

  The specific measurement method is as follows.

  (1) About 200 ml of the electrolytic aqueous solution is put in a glass 250 ml round bottom beaker exclusively for Multisizer 3, set on a sample stand, and the stirrer rod is stirred counterclockwise at 24 rotations / second. Then, the dirt and bubbles in the aperture tube are removed by the “aperture flush” function of the dedicated software.

  (2) About 30 ml of the electrolytic aqueous solution is put into a glass 100 ml flat bottom beaker. In this, "Contaminone N" (nonionic surfactant, anionic surfactant, 10% by weight aqueous solution of neutral detergent for pH7 precision measuring instrument cleaning, made by organic builder, manufactured by Wako Pure Chemical Industries, Ltd. About 0.3 ml of a diluted solution obtained by diluting 3) with ion-exchanged water is added.

  (3) Two oscillators with an oscillation frequency of 50 kHz are incorporated with the phase shifted by 180 degrees, and an ultrasonic disperser “Ultrasonic Dissipation System Tetora 150” (manufactured by Nikki Bios Co., Ltd.) having an electrical output of 120 W is prepared. About 3.3 l of ion-exchanged water is placed in the water tank of the ultrasonic disperser, and about 2 ml of Contaminone N is added to the water tank.

  (4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. And the height position of a beaker is adjusted so that the resonance state of the liquid level of the electrolyte solution in a beaker may become the maximum.

  (5) In a state where the electrolytic aqueous solution in the beaker of (4) is irradiated with ultrasonic waves, about 10 mg of toner is added to the electrolytic aqueous solution little by little and dispersed. Then, the ultrasonic dispersion process is continued for another 60 seconds. In the ultrasonic dispersion, the temperature of the water tank is appropriately adjusted so as to be 10 ° C. or higher and 40 ° C. or lower.

  (6) To the round bottom beaker of (1) installed in the sample stand, the electrolyte solution of (5) in which the toner is dispersed is dropped using a pipette, and the measurement concentration is adjusted to about 5%. . The measurement is performed until the number of measured particles reaches 50,000.

  (7) The measurement data is analyzed with the dedicated software attached to the apparatus, and the weight average particle diameter (D4) and the number average particle diameter (D1) are calculated. When the graph / volume% is set in the dedicated software, the “average diameter” on the “Analysis / volume statistics (arithmetic average)” screen is the weight average particle diameter (D4), and the graph / number% in the dedicated software. The “average diameter” on the “analysis / number statistics (arithmetic mean)” screen is the number average particle diameter (D1).

<Calculation method of coarse powder amount>
The volume-based coarse powder amount (volume%) in the toner is calculated by analyzing the data after measuring the Multisizer 3 described above.

  The volume percentage of particles of 10.0 μm or more in the toner is calculated by the following procedure. First, graph / volume% is set with dedicated software, and the measurement result chart is displayed as volume%. Then, check “>” in the particle size setting portion on the “format / particle size / particle size statistics” screen, and enter “10” in the particle size input section below. When the “analysis / volume statistic (arithmetic average)” screen is displayed, the numerical value of the “> 10 μm” display portion is the volume% of particles of 10.0 μm or more in the toner. The volume percentage of 10 μm or more at this time was defined as the amount of coarse powder.

<Calculation of adhesion rate>
The polymerization container that has been subjected to the polymerization reaction n times in the same polymerization container is washed and dried, and the mass of the scale deposit in the polymerization container is L. Let M be the total solid mass calculated from the toner particle manufacturing recipe. The adhesion rate is
Formula Adhesion rate = L / M / n × 100
Is calculated by

<Manufacture of hydrophobic magnetic iron oxide>
An aqueous solution containing ferrous hydroxide was prepared by mixing 1.0 to 1.1 equivalents of a caustic soda solution with respect to iron ions in an aqueous ferrous sulfate solution. While maintaining the aqueous solution at pH 8, air was blown in, and an oxidation reaction was performed at 80 to 90 ° C. to prepare a slurry liquid for generating seed crystals. Next, after adding ferrous sulfate aqueous solution to this slurry liquid so as to be 0.9 to 1.2 equivalents relative to the initial alkali amount (sodium component of caustic soda), the slurry liquid was maintained at pH = 8, The oxidation reaction was advanced while blowing air, and the pH was adjusted to about 6 at the end of the oxidation reaction to complete the oxidation reaction. The produced iron oxide particles are washed, filtered, and once taken out, re-dispersed in another water without drying, the pH of the re-dispersed liquid is adjusted, and the n-hexyltrimethoxysilane coupling agent is sufficiently stirred. Was added to 100 parts of magnetic iron oxide and stirred sufficiently. The produced hydrophobic iron oxide particles were washed, filtered and dried by a conventional method, and then the aggregated particles were pulverized to obtain hydrophobic magnetic iron oxide having an average particle size of 0.20 μm.

  The evaluation methods for each evaluation performed in the examples and comparative examples of the present invention and the judgment criteria thereof will be described below.

LASER JET2300 was used as the image forming apparatus. Here, a process speed was set to 150 mm / sec, and a development bias in which an alternating electric field of 1.6 kVpp and a frequency of 2200 Hz was superimposed on a DC voltage Vdc of −430 V was used. Under these conditions, the adjusted toner is used, and 6,000 sheets in an intermittent mode with an 8-point A letter and a print rate of 4% in a normal temperature and humidity environment (23 ° C., 60% RH). The image endurance test was conducted. As the recording medium, A4 75 g / m ² paper was used. As a result, there was no fog on the non-image area before and after the durability test, the image density was 1.4 or more, and a high-definition image without scattering was obtained.

<Image density>
The image density formed a solid image portion, and the density of the solid image was measured with a Macbeth reflection densitometer (manufactured by Macbeth).

<Fog>
A white image was output, and the reflectance was measured using a REFECTMETER MODEL TC-6DS manufactured by Tokyo Denshoku. On the other hand, the reflectance of the transfer paper (standard paper) before white image formation was measured in the same manner. As the filter, a green filter was used for black and magenta toners, an amber filter was used for cyan toners, and a blue filter was used for yellow toners. The fog was calculated from the reflectance before and after the white image output using the following formula (6).
Fog (reflectance) (%)
= Reflectance of standard paper (%)-Reflectance of white image sample (%) (6)

The determination criteria for fogging are as follows.
A: Very good (less than 1.5%)
B: Good (1.5% or more and less than 2.5%)
C: Normal (2.5% or more and less than 4.0%)
D: Poor (4.0% or more)

<Toner fusion>
After the durability test, whether or not toner fusion occurred on the toner carrying member was visually determined according to the following criteria.
A: It is not fused.
B: Slightly fused, but not on the image.
C: A level at which some fusion occurs but does not appear on the image.
D: Fusing has occurred, streaks appear on the image, and this is an undesirable level for practical use.

Example 1
1354 parts by mass of 0.5 mol / liter-Na ₃ PO ₄ aqueous solution was stirred at 16000 rpm and heated to 60 ° C. To this, 380 parts by mass of a 3.0 mol / liter-CaCl ₂ aqueous solution was added to obtain a liquid containing calcium phosphate. A part of this liquid water was removed to obtain a liquid B containing calcium phosphate which is a hardly water-soluble inorganic compound.

A 2 liter four-neck separable flask was heated in a hot water bath at 60 ° C., and the liquid B prepared above was placed in the flask and brought into contact with the inner wall. After the excess liquid B was removed from the polymerization vessel, the inside of the flask was dried in a 60 ° C. hot water bath to fix calcium phosphate to the flask surface. The density (mg / cm ² ) of calcium phosphate calculated from the difference in mass of the flask before and after fixing calcium phosphate and the surface area of the inner wall of the flask was calculated. Table 1 shows the kind of the poorly water-soluble inorganic compound, the concentration C _b , the density when fixed to the flask, and the drying temperature.

720 parts by mass of ion-exchanged water and 450 parts by mass of 0.1 mol / liter-Na ₃ PO ₄ aqueous solution are charged into a _4- liter separable flask for 2 liters equipped with Claremix (M Technique Co., Ltd.), 16000 rpm And warmed to 60 ° C. To this, 67.6 parts by mass of a 1.0 mol / liter-CaCl ₂ aqueous solution was added to obtain an aqueous medium containing a calcium phosphate salt. Table 1 shows the types and concentrations of the dispersion stabilizer for the solution in the aqueous dispersion medium.

on the other hand,
Styrene 74 parts by mass n-butyl acrylate 26 parts by mass Divinylbenzene 0.5 parts by mass Saturated polyester resin 15 parts by mass (Polycondensate of bisphenol A and terephthalic acid, Mn = 10000, Mw / Mn = 2.6, acid value = 12mgKOH / g, Tg = 72 ° C)
E-88 (manufactured by Orient Chemical Co., Ltd.) 2 parts by mass negative charge control agent / T-77 (manufactured by Hodogaya Chemical) 1 part by mass hydrophobic magnetic iron oxide 95 parts by mass The above formulation was heated to 60 ° C. and dissolved uniformly. Distributed. 10 parts by weight of paraffin wax (maximum endothermic peak 78 ° C. in DSC) was added and mixed and dissolved, and 6 parts by weight of the polymerization initiator benzoyl peroxide was dissolved therein to obtain a polymerizable monomer composition.

Next, the polymerizable monomer composition is put into the aqueous medium, and stirred at 13,000 rpm for 10 minutes in Claremix (manufactured by M Technique Co., Ltd.) in an N ₂ atmosphere at 60 ° C. and granulated. A polymerizable monomer composition dispersion was obtained.

  The polymerizable monomer composition dispersion prepared above is transferred to the above-mentioned flask to which calcium phosphate is fixed, and the stirring speed of the stirrer equipped with a propeller stirring blade is increased to 200 ° C. and the temperature is raised to 80 ° C. for 8 hours. did. After completion of the polymerization, the suspension was cooled and the slurry was transferred to another container. The slurry remaining in the flask used for the polymerization was thoroughly washed with ion exchange water, dried, and weighed. The same polymerization reaction was performed 7 times using this flask. Table 2 shows the adhesion rate per batch calculated from the amount of scale adhesion in the polymerization vessel at the end of the seventh polymerization.

  Dilute hydrochloric acid was added to the suspension obtained by the seventh polymerization reaction to dissolve calcium phosphate. This slurry was filtered under pressure, then reslurried with ion exchange water 3 times the mass ratio of the toner particles, filtered again under pressure to reduce the water content to 20% or less, and then crushed to 40 ° C. And left in a constant temperature bath for 3 days to dry. Table 2 shows the result of measuring the amount of coarse particles of the dried toner particles. The dried toner particles were classified with a Coanda type airflow classifier to obtain toner particles having a weight average particle diameter (D4) of 7.7 μm.

Hydrophobic silica fine powder 1 having 100 parts by mass of the above toner particles, silica having a primary particle size of 12 nm, treated with hexamethyldisilazane and then treated with silicone oil, and a BET specific surface area value of 120 m ² / g after treatment. 0.0 part by mass was mixed with a Henschel mixer (Mitsui Miike Chemical Co., Ltd.) to prepare a toner. Table 2 shows the results of evaluation of image density, fog, and toner fusion of the obtained toner.

(Example 2)
Toner particles were obtained in the same manner as in Example 1 except that the drying temperature of the polymerization vessel was 40.0 ° C. Table 2 shows the adhesion rate per batch and the results of image evaluation similar to Example 1 performed on the obtained toner particles.

(Example 3)
Toner particles were obtained in the same manner as in Example 1 except that the drying temperature of the polymerization vessel was 80.0 ° C. Table 2 shows the adhesion rate per batch and the results of image evaluation similar to Example 1 performed on the obtained toner particles.

Example 4
Except that the 22% concentration C _b of the liquid B containing the calcium phosphate is a poorly water-soluble inorganic compound to obtain toner particles in the same manner as in Example 1. Table 2 shows the adhesion rate per batch and the results of image evaluation similar to Example 1 performed on the obtained toner particles.

(Example 5)
Except that the 17.9% concentration C _b of the liquid B containing the calcium phosphate is a poorly water-soluble inorganic compound to obtain toner particles in the same manner as in Example 1. Table 2 shows the adhesion rate per batch and the results of image evaluation similar to Example 1 performed on the obtained toner particles.

(Example 6)
720 parts by mass of ion-exchanged water and 450 parts by mass of 0.1 mol / liter-Na ₃ PO ₄ aqueous solution are charged into a _4- liter separable flask for 2 liters equipped with Claremix (M Technique Co., Ltd.), 16000 rpm And warmed to 60 ° C. To this, 67.6 parts by mass of 1.0 mol / liter-CaCl ₂ aqueous solution was added to prepare Liquid B containing calcium phosphate.

  The prepared liquid B was transferred to another container, and the flask was placed in a 60 ° C. hot water bath and dried to fix calcium phosphate to the flask surface. Liquid B was again brought into contact with the dried flask and dried in a 60 ° C. hot water bath. Toner particles were obtained in the same manner as in Example 1 except that this flask was used as a polymerization container. Table 2 shows the adhesion rate per batch and the results of image evaluation similar to Example 1 performed on the obtained toner particles.

(Example 7)
520 parts by mass of ion-exchanged water and 450 parts by mass of 0.1 mol / liter-Na ₃ PO ₄ aqueous solution were charged into a _4- liter separable flask for 2 liters equipped with Claremix (M Technique Co., Ltd.), and 16000 rpm And warmed to 60 ° C. To this, 67.6 parts by mass of 1.0 mol / liter-CaCl ₂ aqueous solution was added to prepare Liquid B containing calcium phosphate.

  The prepared liquid B was transferred to another container, and the flask was placed in a 60 ° C. hot water bath and dried to fix calcium phosphate to the flask surface. Liquid B was again brought into contact with the dried flask and dried in a 60 ° C. hot water bath. Toner particles were obtained in the same manner as in Example 1 except that this flask was used as a polymerization container. Table 2 shows the adhesion rate per batch and the results of image evaluation similar to Example 1 performed on the obtained toner particles.

(Example 8)
720 parts by mass of ion-exchanged water and 450 parts by mass of 0.1 mol / liter-Na ₃ PO ₄ aqueous solution are charged into a _4- liter separable flask for 2 liters equipped with Claremix (M Technique Co., Ltd.), 16000 rpm And warmed to 60 ° C. To this, 67.6 parts by mass of 1.0 mol / liter-CaCl ₂ aqueous solution was added to prepare Liquid B containing calcium phosphate.

Toner particles were obtained in the same manner as in Example 1 except that this liquid B was transferred to another container, the flask was placed in a 60 ° C. water bath and dried, and calcium phosphate was fixed to the flask surface to form a polymerization container. At this time, the density of the poorly water-soluble inorganic compound fixed to the surface of the flask was 0.05 (mg / cm ² ). Table 2 shows the adhesion rate per batch and the results of image evaluation similar to Example 1 performed on the obtained toner particles.

Example 9
The concentration C _b of the liquid B containing the calcium phosphate is a poorly water-soluble inorganic compound is 23%, except that repeated drying and liquid contact B 2 times to obtain toner particles in the same manner as in Example 1. At this time, the density of the poorly water-soluble inorganic compound fixed on the surface of the flask was 7.61 (mg / cm ² ). Table 2 shows the adhesion rate per batch and the results of image evaluation similar to Example 1 performed on the obtained toner particles.

( Reference Example 10)
To an aqueous solution in which 221 parts by mass of magnesium chloride is dissolved in 720 parts by mass of ion-exchanged water, an aqueous solution in which 185.6 parts by mass of sodium hydroxide is dissolved in 510 parts by mass of ion-exchanged water is gradually added with stirring. Liquid B containing magnesium was prepared.

  A 2 liter four-necked separable flask was heated in a 60 ° C. hot water bath, and the liquid B prepared above was placed on the inner wall and brought into contact with the inner wall. After removing excess liquid B from the polymerization vessel, toner particles were obtained in the same manner as in Example 1 except that the inside of the flask was dried in a 60 ° C. hot water bath and magnesium hydroxide was fixed to the flask surface. . Table 2 shows the adhesion rate per batch and the result of image evaluation similar to that of Example 1 performed on the obtained toner particles.

(Example 11)
Toner particles were obtained in the same manner as in Example 1 except that the drying temperature of the polymerization vessel was 35.0 ° C. Table 2 shows the adhesion rate per batch and the results of image evaluation similar to Example 1 performed on the obtained toner particles.

(Example 12)
Toner particles were obtained in the same manner as in Example 1 except that the drying temperature of the polymerization vessel was 85.0 ° C. Table 2 shows the adhesion rate per batch and the results of image evaluation similar to Example 1 performed on the obtained toner particles.

(Example 13)
After preparing the liquid B under the conditions of Example 6, toner particles were obtained in the same manner as in Example 1 except that water was added to adjust the calcium phosphate concentration to 0.50% by mass. Table 2 shows the adhesion rate per batch and the results of image evaluation similar to Example 1 performed on the obtained toner particles.

(Example 14)
Toner particles were obtained in the same manner as in Example 6 except that liquid B was prepared under the conditions of Example 1. Table 2 shows the adhesion rate per batch and the results of image evaluation similar to Example 1 performed on the obtained toner particles.

( Reference Example 15)
The toner was prepared in the same manner as in Example 1 except that Snowtex 20 (Nissan Chemical Industries) diluted twice with water was used as Liquid B, and the sparingly water-soluble inorganic compound contained in Liquid B was changed to silica. Particles were obtained. Table 2 shows the adhesion rate per batch and the results of image evaluation similar to Example 1 performed on the obtained toner particles.

(Comparative Example 1)
Toner particles were obtained in the same manner as in Example 1 except that the solution to be contact-dried on the surface of the polymerization vessel was a 12% by weight polyvinyl alcohol solution. Table 2 shows the adhesion rate per batch and the results of image evaluation performed on the obtained toner particles in the same manner as in Example 1.

(Comparative Example 2)
1354 parts by mass of 0.5 mol / liter-Na ₃ PO ₄ aqueous solution was stirred at 16000 rpm and heated to 60 ° C. To this, 380 parts by mass of a 3.0 mol / liter-CaCl ₂ aqueous solution was added to obtain a liquid containing calcium phosphate. A part of this liquid water was removed to obtain a liquid B containing a hardly water-soluble inorganic compound.

  A 2-liter four-necked separable flask was placed in a 60 ° C. hot water bath, the prepared liquid B was placed in the flask, brought into contact with the inner wall, and the polymerization step was carried out without drying. Toner particles were obtained. Table 2 shows the adhesion rate per batch and the results of image evaluation similar to Example 1 performed on the obtained toner particles.

(Comparative Example 3)
720 parts by mass of ion-exchanged water and 450 parts by mass of 0.1 mol / liter-Na ₃ PO ₄ aqueous solution are charged into a _4- liter separable flask for 2 liters equipped with Claremix (M Technique Co., Ltd.), 16000 rpm And warmed to 60 ° C. To this, 67.6 parts by mass of 1.0 mol / liter-CaCl ₂ aqueous solution was added to prepare Liquid B containing calcium phosphate.

  The prepared liquid B was transferred to another container, and the flask was placed in a 60 ° C. hot water bath and dried to fix calcium phosphate to the flask surface. Liquid B was brought into contact with the dried flask again and placed in a 60 ° C. water bath to dry the inside. This flask was used as a polymerization vessel.

  In a 4-liter separable flask for 2 liters equipped with Claremix (M Technique), 0.21 parts by mass of polyvinyl alcohol is added to 1230 parts by mass of ion-exchanged water, and heated to 60 ° C. and heated at 12000 rpm. Stir. Toner particles were obtained in the same manner as in Example 1 except that this solution was used as an aqueous dispersion medium. Table 2 shows the adhesion rate per batch and the results of image evaluation similar to Example 1 performed on the obtained toner particles.

(Reference Example A )
720 parts by mass of ion-exchanged water and 450 parts by mass of 0.1 mol / liter-Na ₃ PO ₄ aqueous solution are charged into a _4- liter separable flask for 2 liters equipped with Claremix (M Technique Co., Ltd.), 16000 rpm And warmed to 60 ° C. To this, 67.6 parts by mass of a 1.0 mol / liter-CaCl ₂ aqueous solution was added to obtain an aqueous medium containing a calcium phosphate salt .

on the other hand,
Styrene 74 parts by mass n-butyl acrylate 26 parts by mass Divinylbenzene 0.5 parts by mass Saturated polyester resin 15 parts by mass (Polycondensate of bisphenol A and terephthalic acid, Mn = 10000, Mw / Mn = 2.6, acid value = 12mgKOH / g, Tg = 72 ° C)
E-88 (manufactured by Orient Chemical Co., Ltd.) 2 parts by mass negative charge control agent / T-77 (manufactured by Hodogaya Chemical) 1 part by mass hydrophobic magnetic iron oxide 95 parts by mass The above formulation was heated to 60 ° C. and dissolved uniformly. Distributed. Thereto was added 10 parts by mass of paraffin wax (maximum endothermic peak at DSC of 78 ° C.), mixed and dissolved, and 6 parts of the polymerization initiator benzoyl peroxide was dissolved therein to obtain a polymerizable monomer composition.

Next, the polymerizable monomer composition is put into the aqueous medium, and stirred at 13,000 rpm for 10 minutes in a Claremix (manufactured by M Technique Co., Ltd.) in an N ₂ atmosphere at 60 ° C. and granulated. A polymerizable monomer composition dispersion was obtained.

Was prepared in the polymerizable monomer composition dispersion is transferred to the flasks, the rotation speed 200rpm stirrer equipped with a propeller stirring blade, the polymerization was raised the temperature to 80 ° C. and polymerization for 8 hours. After completion of the polymerization, the suspension was cooled and the slurry was transferred to another container. The slurry remaining in the flask used for the polymerization was thoroughly washed with ion-exchanged water, dried and measured for mass. Using this flask, the same polymerization reaction was carried out five times in the same manner. Table 2 shows the adhesion rate per batch calculated from the amount of coarse particles of toner particles obtained at the end of the fifth polymerization and the amount of scale attached in the polymerization container at the end of the seventh polymerization.

  Dilute hydrochloric acid was added to the suspension obtained by the seventh polymerization reaction to dissolve calcium phosphate. This slurry was filtered under pressure, then reslurried with ion exchange water 3 times the mass ratio of the toner particles, filtered again under pressure to reduce the water content to 20% or less, and then crushed to 40 ° C. And left in a constant temperature bath for 3 days to dry. The dried toner particles were classified by a Coanda type airflow classifier to obtain toner particles having a weight average particle diameter of 7.7 μm.

Hydrophobic silica fine powder 1 having 100 parts by mass of the above toner particles, silica having a primary particle size of 12 nm, treated with hexamethyldisilazane and then treated with silicone oil, and a BET specific surface area value of 120 m ² / g after treatment. 0.0 part by mass was mixed with a Henschel mixer (Mitsui Miike Chemical Co., Ltd.) to prepare a toner. Table 2 shows the evaluation results of the image density, fogging, and toner fusion described above for the obtained toner.

It is sectional drawing of the suitable superposition | polymerization container used for this invention. It is sectional drawing of the suitable superposition | polymerization container used for this invention provided with the shower nozzle. 1 is a schematic diagram illustrating an example of an image forming apparatus used in an embodiment of the present invention. FIG. 4 is an enlarged view illustrating a configuration of a developing unit portion of the image forming apparatus illustrated in FIG. 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Polymerization container 2 Stirrer 3 Baffle 4 Drive device 5 Gas-liquid interface 6 Temperature control jacket 7 Shower nozzle 100 Photoconductor 102 Developing sleeve (toner carrier)
103 Elastic Blade 104 Magnet Roller 114 Transfer Charging Roller 116 Cleaner 117 Primary Charging Roller 121 Laser Generator 123 Laser Light 124 Register Roller 125 Conveying Belt 126 Fixing Device 140 Developing Device 141 Toner Application Roller

Claims (7)

Prepare a polymerizable monomer and a polymerizable monomer composition containing a colorant, are dispersed in an aqueous dispersion medium containing an inorganic dispersion stabilizer (Liquid A), the polymerizable monomer composition dispersion Granulating process , and
In the production method of the toner particles containing at least the polymerizable monomer composition Ru by polymerizing the polymerization process which is present as droplets in the polymerizable monomer composition dispersion,
The production method further includes a step of bringing a liquid (liquid B) containing a poorly water-soluble inorganic compound into contact with at least a part of the inner wall of the polymerization vessel used in the polymerization step, followed by drying .
The method for producing toner particles, wherein the hardly water-soluble inorganic compound is a hardly water-soluble metal phosphate obtained by mixing an alkali metal phosphate aqueous solution and a metal halide aqueous solution . Wherein the dried cell process, said inner wall of the polymerization vessel was warmed method for producing toner particles according to 請 Motomeko 1 the liquid B in contact with the inner wall of the polymerization vessel Ru dried. Wherein the dried cell process, method for producing the toner particles of claim 2, the inner wall of the polymerization vessel warmed in the range of 40.0 ° C. over 80.0 ° C. or less. An inorganic dispersion stabilizer used in the granulation step, and the dried to the slightly water-soluble inorganic compound used in step is production of the toner particles according to any one of 請 Motomeko 1-3 Ru der same composition Method. Wherein the said liquid A mineral dispersion stabilizer concentration C _a (mass%), and the concentration C _b of the slightly water-soluble inorganic compound in the liquid B (wt%) but, 1.0 C _a ≦ C _b ≦ method for producing toner particles according to any one of 請 Motomeko 1-4 satisfying the relationship 40.0C _a. The concentration C _a (mass%), the concentration C _b and (by weight percent), the production method of the toner particles according to 請 Motomeko 5 that satisfy the relation 1.2C _a ≦ C _b ≦ 32.0C _a . Wherein in the polymerization step, the hardly water-soluble inorganic compound, either 請 Motomeko 1-6 that exist at 0.05 mg / cm ² or more 7.50mg / cm ² or less of the density on the surface of the inner wall of the polymerization vessel 2. A method for producing toner particles according to item 1 .

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