JP2006152060A - Method for producing resin particulate and resin particulate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing resin particulates having excellent mechanical strength, uniform shape and narrow particle size distribution while preventing unintentional degeneration of the resin constituting the resin particulate and provide resin particulates produced by the method. <P>SOLUTION: The method for producing resin particulates uses a dispersion liquid containing a dispersoid made mainly of a resin material in a dispersant in finely dispersed state. The method has a step to eject the dispersion liquid in the form of droplets and a step to remove the dispersant from the dispersion liquid droplets. A coagulation preventing layer to prevent or suppress the coagulation of the dispersoid is formed on the surface of the dispersoid. The coagulation preventing layer is formed by applying a material to form the coagulation preventing layer to the dispersion liquid ejected in the form of droplets. The application of the material is carried out by spraying the layer-forming liquid containing the material in finely dispersed state to the dispersion liquid ejected in the form of droplets. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing resin fine particles and resin fine particles.

Examples of fine particles mainly composed of a resin material, that is, resin fine particles include toners used in image forming apparatuses such as printers, copiers, and facsimiles that employ an electrophotographic method, and powder paints.
As a method for producing such resin fine particles, a method is known in which resin fine particles are obtained by solidifying droplets of a dispersion liquid in which a dispersoid containing a resin is finely dispersed in a dispersion medium (for example, Patent Documents). 1).

For example, in Patent Document 1, a dispersion liquid in which a dispersoid containing resin is dispersed is ejected as droplets from a nozzle by an inkjet method, and the dispersion medium is removed from the droplets while the droplets are conveyed in an air stream. Thus, resin fine particles are obtained. At that time, the droplets contain a plurality of dispersoids, and the resin fine particles obtained are aggregates obtained by agglomerating a plurality of fine particles derived from the dispersoids.
However, in the method of Patent Document 1, resin fine particles are obtained as an aggregate of fine particles derived from a plurality of dispersoids, so that the particles are easily divided between the fine particles and have low strength. Also, for the purpose of increasing the strength of the resin fine particles, it is conceivable to melt-bond the fine particles derived from the dispersoids at a high temperature. Is difficult. In addition, the resin fine particles obtained may not have the desired characteristics due to unintentional modification of the constituent resin.

  In addition, when the droplets are heated at a relatively high temperature in order to quickly remove the dispersion medium from the droplets of the dispersion liquid and then the particles from the dispersoid are aggregated, the particles become unwilling. Will join. As a result, the dispersion medium is difficult to remove from the inside of the droplet, and the resulting aggregate is formed with a hollow portion or having an irregular shape. As a result, the obtained toner has large variations in particle size and shape. When such resin fine particles are used as the toner, when the toner image is formed, the toner particles cannot be frictionally charged with each other, which may cause a charging failure, and the toner particles may be electrostatically applied to the photosensitive drum. There is a risk of causing a transfer defect when it is adhered. Further, when such resin fine particles are used as a powder coating material, coating film defects such as cracks and pinholes may occur in the coating film depending on the coating conditions.

Japanese Patent Laid-Open No. 2004-070303

  An object of the present invention is to produce resin fine particles having a uniform shape and a small width of particle size distribution while improving mechanical strength while preventing unintentional modification of the resin constituting the resin fine particles. It is an object to provide a method for producing resin fine particles and resin fine particles.

Such an object is achieved by the present invention described below.
The method for producing resin fine particles of the present invention is a method for producing resin fine particles using a dispersion in which a dispersoid mainly composed of a resin material is finely dispersed in a dispersion medium,
Discharging the dispersion into droplets;
Removing the dispersion medium from the droplet-like dispersion liquid,
An aggregation preventing layer that prevents or suppresses aggregation of the dispersoids is formed on the surface of the dispersoid.

  Thereby, in the dispersion medium removing step, each fine particle derived from the dispersoid can be made into resin fine particles. Since the resin fine particles thus obtained are not aggregates of fine particles, they have excellent mechanical strength. Moreover, since granulation (aggregation) is not required to obtain resin fine particles, it is possible to prevent the generation of particles having hollow portions (hollow particles) or irregularly shaped particles. As a result, it is possible to efficiently produce resin fine particles having a uniform shape and a narrow particle size distribution. Further, since it is not necessary to melt and bond the fine particles derived from the dispersoids at a high temperature in order to obtain mechanical strength, unintentional modification of the resin constituting the resin fine particles can be prevented.

In the method for producing resin fine particles of the present invention, the formation of the aggregation preventing layer is preferably carried out by applying a material for forming the aggregation preventing layer to the dispersion discharged in the form of droplets.
Thereby, in the dispersion medium removing step, each fine particle derived from the dispersoid can be made into the resin fine particle more reliably.

In the method for producing resin fine particles of the present invention, it is preferable that the material is applied by spraying a layer forming liquid in which the material is finely dispersed onto the dispersion liquid discharged in the form of droplets.
Thereby, the material which should form an aggregation prevention layer easily and reliably can be provided to the discharged dispersion liquid.

In the method for producing resin fine particles of the present invention, when the average particle size of the dispersoid is Dm [μm] and the average particle size of the material in the layer forming liquid is Dc [μm], 1 × 10 ⁻³ It is preferable that the relationship of ≦ Dc / Dm ≦ 1 × 10 ⁻¹ is satisfied.
Thereby, the aggregation preventing layer can be reliably formed on the surface of the dispersoid, and the dispersoids in the liquid dispersion can be effectively prevented from aggregating. Then, each fine particle derived from the dispersoid can be made into a resin fine particle more reliably. As a result, resin fine particles having excellent mechanical strength and a uniform shape can be obtained.

In the method for producing resin fine particles of the present invention, the average particle size of the material in the layer forming liquid is preferably 0.02 to 1.0 μm.
Thereby, the aggregation preventing layer can be reliably formed on the surface of the dispersoid, and the dispersoids in the liquid dispersion can be effectively prevented from aggregating. Then, each fine particle derived from the dispersoid can be made into a resin fine particle more reliably. As a result, resin fine particles having excellent mechanical strength and a uniform shape can be obtained.

In the method for producing resin fine particles of the present invention, it is preferable that the aggregation preventing layer is mainly composed of a fluororesin.
Thereby, aggregation of dispersoids can be prevented more reliably.
In the method for producing resin fine particles of the present invention, the fluororesin is preferably polytetrafluoroethylene.
Thereby, aggregation of dispersoids can be prevented more reliably.

In the method for producing resin fine particles of the present invention, when the average particle diameter of the discharged liquid droplet is Dd [μm] and the average particle diameter of the dispersoid is Dm [μm], 0.5 < It is preferable that the relationship of Dm / Dd <1.0 is satisfied.
Thereby, it is possible to prevent two or more dispersoids from being included in the discharged dispersion liquid. As a result, the liquid dispersion in the form of droplets can contain one dispersoid in the dispersion medium, or can be substantially composed of only the dispersion medium without containing the dispersoid. Thereby, it is possible to more reliably prevent the dispersoids from aggregating with each other, and it is possible to obtain resin particles having excellent mechanical strength and a uniform shape.

In the method for producing resin fine particles of the present invention, in the step of removing the dispersion medium, it is preferable to remove the dispersion medium by heating at a temperature lower than the boiling point of the dispersion medium.
As a result, in the dispersion medium removal step, the dispersion medium can be efficiently removed while more effectively preventing the fine particles derived from the dispersoids from joining and aggregating, and the shape uniformity of the resulting resin fine particles , The stability can be made sufficiently high. As a result, it is possible to obtain resin fine particles with less variation in shape and size between the particles, and to produce resin fine particles with high sphericity (geometrically perfect sphere shape). Can be made relatively easy.

In the method for producing resin fine particles of the present invention, the resin fine particles are preferably toner particles.
Thus, it is possible to provide a toner having a uniform shape and a small width of particle size distribution while improving mechanical strength while preventing unintentional modification of the resin constituting the toner. As a result, when forming an image, it is possible to obtain an excellent image by exhibiting excellent charging characteristics and transfer characteristics.

In the method for producing resin fine particles of the present invention, the resin fine particles are preferably a powder paint.
Accordingly, it is possible to provide a powder coating material having a uniform shape and a small width of particle size distribution while improving mechanical strength while preventing unintentional modification of the resin constituting the powder coating material. it can. In particular, since the generation of hollow particles and irregularly shaped particles can be prevented, when a coating film is formed using a powder coating material, it is possible to prevent pinholes and voids from occurring in the coating film. it can.

The resin fine particles of the present invention are produced by the method for producing resin fine particles of the present invention.
Accordingly, it is possible to provide resin fine particles having a uniform shape and a small width of particle size distribution while improving mechanical strength while preventing unintentional modification of the resin constituting the resin fine particles.

In the resin fine particles of the present invention, the average circularity R represented by the following formula (I) is preferably 0.95 or more.
R = L ₀ / L ₁ (I)
(Where, L ₁ [μm] is the circumference of the projected image of the resin fine particle to be measured, and L ₀ [μm] is the circumference of a perfect circle having an area equal to the area of the projected image of the resin fine particle to be measured) Represents length)
Thereby, for example, when resin fine particles are applied to the toner, variations in characteristics such as charging characteristics and fixing characteristics among the toner particles are particularly reduced, and the reliability of the entire toner is further improved.

In the resin fine particles of the present invention, the standard deviation of the average circularity between the particles is preferably 0.015 or less.
Thereby, for example, when resin fine particles are applied to the toner, variations in characteristics such as charging characteristics and fixing characteristics among the toner particles are particularly reduced, and the reliability of the entire toner is further improved.

In the resin fine particles of the present invention, the bulk density is preferably 0.34 g / cm ³ or more.
Thereby, for example, when resin fine particles are applied to toner, it is possible to achieve excellent charging characteristics and durability. Further, it is possible to increase the amount of toner filled in the cartridge of the same volume, and to reduce the size of the cartridge.

Hereinafter, based on an accompanying drawing, a resin fine particle manufacturing method of the present invention and a suitable embodiment of resin fine particles are described in detail.
The resin fine particles obtained by the method for producing resin fine particles of the present invention may be any resin particles as long as they are mainly composed of a resin material. Among various resin fine particles, printers and copying machines that employ an electrophotographic method. Toners used in image forming apparatuses such as printers and facsimiles are required to have a more uniform size and shape uniformity among particles, and the effects of applying the present invention are particularly prominent. It is. Therefore, in the following description, toner particles will be representatively described as an example of resin fine particles. In the present specification, “resin fine particles” refers to particles (powder) mainly composed of a resin material, and may include components other than the resin material.

[Dispersion]
First, the dispersion 6 used in the present invention will be described.
The resin fine particles of the present invention are produced using the dispersion liquid 6. In the following description, the case where the resin fine particles of the present invention are applied to toner will be described.
Examples of the dispersion 6 include a suspension (suspension) and an emulsion (emulsion, emulsion, emulsion). In this specification, “suspension” refers to a dispersion (including a suspended colloid) in which a solid (solid) dispersoid (suspended particle) is dispersed in a liquid dispersion medium. The term “emulsified liquid (emulsion, emulsion, milky liquid)” refers to a dispersion in which a liquid dispersoid (dispersed particles) is dispersed in a liquid dispersion medium. In the dispersion liquid, a solid dispersoid and a liquid dispersoid may coexist. In such a case, among the dispersoids in the dispersion, those in which the proportion of the solid dispersoid is larger than the proportion of the liquid dispersoid is called a suspension, and the proportion of the liquid dispersoid is solid. What is larger than the proportion of the dispersoid in the form of a powder is called an emulsion. In particular, it is preferable that the dispersion used in the present invention has been deaerated. The deaeration process will be described in detail later.
The dispersion 6 has a configuration in which a dispersoid (dispersed phase) 61 is finely dispersed in a dispersion medium 62.

<Dispersion medium>
The dispersion medium 62 may be any material as long as the dispersoid 61 described below can be dispersed, but is mainly a material generally used as a solvent (hereinafter also referred to as “solvent material”). It is preferred that it is constructed.
Examples of such materials include inorganic solvents such as water, carbon disulfide, and carbon tetrachloride, methyl ethyl ketone (MEK), acetone, diethyl ketone, methyl isobutyl ketone (MIBK), methyl isopropyl ketone (MIPK), cyclohexanone, Ketone solvents such as 3-heptanone and 4-heptanone, methanol, ethanol, n-propanol, isopropanol, n-butanol, i-butanol, t-butanol, 3-methyl-1-butanol, 1-pentanol, 2- Alcohol solvents such as pentanol, n-hexanol, cyclohexanol, 1-heptanol, 1-octanol, 2-octanol, 2-methoxyethanol, allyl alcohol, furfuryl alcohol, phenol, diethyl ether, dipropyl ether Ether solvents such as diisopropyl ether, dibutyl ether, 1,2-dimethoxyethane (DME), 1,4-dioxane, tetrahydrofuran (THF), tetrahydropyran (THP), anisole, diethylene glycol dimethyl ether (diglyme), 2-methoxyethanol Cellosolve solvents such as methyl cellosolve, ethyl cellosolve, phenyl cellosolve, aliphatic hydrocarbon solvents such as hexane, pentane, heptane, cyclohexane, methylcyclohexane, octane, didecane, methylcyclohexene, isoprene, toluene, xylene, benzene, ethylbenzene , Aromatic hydrocarbon solvents such as naphthalene, pyridine, pyrazine, furan, pyrrole, thiophene, 2-methylpyridine, 3-methylpyridine, 4-methyl Aromatic heterocyclic compound solvents such as pyridine and furfuryl alcohol, amide solvents such as N, N-dimethylformamide (DMF) and N, N-dimethylacetamide (DMA), dichloromethane, chloroform, 1,2-dichloroethane, Halogenated solvents such as trichloroethylene and chlorobenzene, acetylacetone, ethyl acetate, methyl acetate, isopropyl acetate, isobutyl acetate, isopentyl acetate, ethyl chloroacetate, butyl chloroacetate, isobutyl chloroacetate, ethyl formate, isobutyl formate, ethyl acrylate, methacrylic acid Ester solvents such as methyl acid, ethyl benzoate, amine solvents such as trimethylamine, hexylamine, triethylamine, aniline, nitrile solvents such as acrylonitrile, acetonitrile, nitromethane, Examples include nitro solvents such as nitroethane, organic solvents such as aldehyde solvents such as acetaldehyde, propionaldehyde, butyraldehyde, pentanal, and acrylic aldehyde. A mixture of one or more selected from these is used. be able to.

  Among the above materials, the dispersion medium 62 is mainly composed of water and / or a liquid having excellent compatibility with water (for example, a liquid having a solubility in 100 g of water at 25 ° C. of 30 g or more). preferable. Thereby, for example, the dispersibility of the dispersoid 61 in the dispersion medium 62 can be enhanced, and the dispersoid 61 in the dispersion liquid 6 has a relatively small particle diameter and small variation in size. be able to. As a result, the finally obtained toner, that is, the resin fine particles, has a small variation in size and shape between the particles and a large circularity. In particular, when the dispersion medium 62 is composed of water, for example, in the toner manufacturing process, the organic solvent can be substantially prevented from volatilizing. As a result, the toner can be produced by a method that hardly causes adverse effects on the environment, that is, an environmentally friendly method.

  When a mixture of a plurality of components is used as the constituent material of the dispersion medium 62, the constituent material of the dispersion medium is an azeotrope (lowest boiling point azeotrope) between at least two components constituting the mixture. It is preferable to use one that can form As a result, the dispersion medium 62 can be efficiently removed in the conveyance unit 3 of the toner manufacturing apparatus 1 described later. In addition, it becomes possible to remove the dispersion medium 62 at a relatively low temperature in the conveyance unit 3 of the toner manufacturing apparatus 1 to be described later, and more effectively prevent the deterioration of the properties of the finally obtained toner (toner particles). it can. For example, liquids that can form an azeotrope with water include carbon disulfide, carbon tetrachloride, methyl ethyl ketone (MEK), acetone, cyclohexanone, 3-heptanone, 4-heptanone, ethanol, n-propanol, Isopropanol, n-butanol, i-butanol, t-butanol, 3-methyl-1-butanol, 1-pentanol, 2-pentanol, n-hexanol, cyclohexanol, 1-heptanol, 1-octanol, 2-octanol 2-methoxyethanol, allyl alcohol, furfuryl alcohol, phenol, dipropyl ether, dibutyl ether, 1,4-dioxane, anisole, 2-methoxyethanol, hexane, heptane, cyclohexane, methylcyclohexane, octane, dideca , Methylcyclohexene, isoprene, toluene, benzene, ethylbenzene, naphthalene, pyridine, 2-methylpyridine, 3-methylpyridine, 4-methylpyridine, furfuryl alcohol, chloroform, 1,2-dichloroethane, trichloroethylene, chlorobenzene, acetylacetone, acetic acid Ethyl acetate, methyl acetate, isopropyl acetate, isobutyl acetate, isopentyl acetate, ethyl chloroacetate, butyl chloroacetate, isobutyl chloroacetate, ethyl formate, isobutyl formate, ethyl acrylate, methyl methacrylate, ethyl benzoate, trimethylamine, hexylamine, triethylamine Aniline, acrylonitrile, acetonitrile, nitromethane, nitroethane, acrylic aldehyde and the like.

Further, the boiling point of the dispersion medium 62 is not particularly limited, but is preferably 180 ° C. or lower, more preferably 150 ° C. or lower, and further preferably 35 to 130 ° C. As described above, when the boiling point of the dispersion medium 62 is relatively low, the dispersion medium 62 can be removed relatively easily in the conveyance unit 3 of the toner manufacturing apparatus 1 described later. Further, by using such a material as the dispersion medium 62, the residual amount of the dispersion medium 62 in the finally obtained toner particles can be made particularly small. As a result, the reliability as a toner is further increased.
The dispersion medium 62 may contain components other than the materials described above. For example, in the dispersion medium 62, various materials such as materials exemplified later as constituents of the dispersoid 61, inorganic fine powders such as silica, titanium oxide, and iron oxide, organic fine powders such as fatty acids and fatty acid metal salts, etc. Additives and the like may be included.

<Dispersed quality>
The dispersoid 61 is usually made of a material containing at least a resin as a main component or a precursor thereof (hereinafter collectively referred to as “resin material”). Examples of the resin precursor include a monomer, a dimer, and an oligomer of the resin.
Hereinafter, the constituent material of the dispersoid 61 will be described.

1. Resin (binder resin)
Examples of the resin (binder resin) include (meth) acrylic resin, polycarbonate resin, polystyrene, poly-α-methylstyrene, chloropolystyrene, styrene-chlorostyrene copolymer, styrene-propylene copolymer, and styrene-butadiene. Copolymer, Styrene-vinyl chloride copolymer, Styrene-vinyl acetate copolymer, Styrene-maleic acid copolymer, Styrene-acrylic acid ester copolymer, Styrene-methacrylic acid ester copolymer, Styrene-acrylic acid Styrene or styrene substitution with styrenic resins such as ester-methacrylic acid ester copolymer, styrene-α-methyl chloroacrylate copolymer, styrene-acrylonitrile-acrylic acid ester copolymer, styrene-vinyl methyl ether copolymer Unipolymerization involving the body Body or copolymer, polyester resin, epoxy resin, urethane modified epoxy resin, silicone modified epoxy resin, vinyl chloride resin, rosin modified maleic acid resin, phenyl resin, polyethylene, polypropylene, ionomer resin, polyurethane resin, silicone resin, ketone resin , Ethylene-ethyl acrylate copolymer, xylene resin, polyvinyl butyral resin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, etc., and one or a combination of two or more of these may be used. Can do. In addition, when the toner is manufactured by polymerizing the raw material in the dispersoid 61 in the transport unit 3 of the toner manufacturing apparatus 1 to be described later, the resin material monomer, dimer, oligomer, or the like is usually used.

When a thermosetting resin is used as the constituent material of the dispersoid 61, irregularly shaped resin fine particles, particularly, irregularly shaped resin fine particles due to bonding of the resin fine particles 9 are effectively prevented in the dispersion medium removing step described later. As a result, it is possible to obtain resin fine particles with smaller variations in shape and size between the particles.
The content of the resin in the dispersoid 61 is not particularly limited, but is preferably 2 to 98 wt%, more preferably 5 to 95 wt%.

Moreover, it is preferable that the glass transition point of resin which comprises the dispersoid 61 is 50-70 degreeC. Thereby, suitable resin fine particles 9 can be efficiently obtained in the dispersion medium removing step described later. When the resin material constituting the dispersoid 61 is composed of a plurality of types of resin materials (resin components), the glass of the resin (component) constituting the main component of the dispersoid 61 as the glass transition point of the resin. Adopt a transition point.
Moreover, it is preferable that melting | fusing point of resin which comprises the dispersoid 61 is 90-150 degreeC. Thereby, the dispersion medium removal process mentioned later can be performed efficiently. When the resin material constituting the dispersoid 61 is composed of a plurality of types of resin materials (resin components), the melting point of the resin (component) constituting the main component of the dispersoid 61 is adopted as the melting point of the resin. To do.

2. Solvent The dispersoid 61 may contain a solvent that dissolves at least a part of its components. Thereby, for example, the fluidity of the dispersoid 61 in the dispersion liquid 6 can be improved, and the dispersoid 61 in the dispersion liquid 6 has a relatively small particle size and small variation in size. be able to. As a result, the finally obtained toner (toner particles) is small in size and shape variation between particles and has a large circularity.

The solvent may be any solvent as long as it dissolves at least a part of the components constituting the dispersoid 61, but can be easily removed by the transport unit 3 of the toner manufacturing apparatus 1 described later. Preferably there is.
The solvent is preferably a solvent having low compatibility with the dispersion medium 62 described above (for example, a solvent having a solubility in 100 g of the dispersion medium at 25 ° C. of 30 g or less). Thereby, the dispersoid 61 can be finely dispersed in the dispersion 6 in a stable state.
Moreover, the composition of the solvent can be appropriately selected according to, for example, the composition of the resin and the colorant described above, the composition of the dispersion medium, and the like.

  Examples of the solvent include inorganic solvents such as water, carbon disulfide, and carbon tetrachloride, methyl ethyl ketone (MEK), acetone, diethyl ketone, methyl isobutyl ketone (MIBK), methyl isopropyl ketone (MIPK), cyclohexanone, and 3-heptanone. , Ketone solvents such as 4-heptanone, methanol, ethanol, n-propanol, isopropanol, n-butanol, i-butanol, t-butanol, 3-methyl-1-butanol, 1-pentanol, 2-pentanol, Alcohol solvents such as n-hexanol, cyclohexanol, 1-heptanol, 1-octanol, 2-octanol, 2-methoxyethanol, allyl alcohol, furfuryl alcohol, phenol, diethyl ether, dipropyl ether, diisopropyl Ether solvents such as pyr ether, dibutyl ether, 1,2-dimethoxyethane (DME), 1,4-dioxane, tetrahydrofuran (THF), tetrahydropyran (THP), anisole, diethylene glycol dimethyl ether (diglyme), 2-methoxyethanol Cellosolve solvents such as methyl cellosolve, ethyl cellosolve, phenyl cellosolve, aliphatic hydrocarbon solvents such as hexane, pentane, heptane, cyclohexane, methylcyclohexane, octane, didecane, methylcyclohexene, isoprene, toluene, xylene, benzene, ethylbenzene , Aromatic hydrocarbon solvents such as naphthalene, pyridine, pyrazine, furan, pyrrole, thiophene, 2-methylpyridine, 3-methylpyridine, 4-methylpyridine Aromatic heterocyclic compound solvents such as furfuryl alcohol, amide solvents such as N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMA), dichloromethane, chloroform, 1,2-dichloroethane, trichlorethylene, Halogenated solvents such as chlorobenzene, acetylacetone, ethyl acetate, methyl acetate, isopropyl acetate, isobutyl acetate, isopentyl acetate, ethyl chloroacetate, butyl chloroacetate, isobutyl chloroacetate, ethyl formate, isobutyl formate, ethyl acrylate, methyl methacrylate Ester solvents such as ethyl benzoate, amine solvents such as trimethylamine, hexylamine, triethylamine and aniline, nitrile solvents such as acrylonitrile and acetonitrile, nitromethane, nitroethane Organic solvents such as nitro solvents such as aldehyde, aldehyde solvents such as acetaldehyde, propionaldehyde, butyraldehyde, pentanal, acrylic aldehyde, etc. are used, and one or a mixture of two or more selected from these is used. be able to. Among these, those containing an organic solvent are preferred, and ether solvents, cellosolve solvents, aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents, aromatic heterocyclic compounds solvents, amide solvents, halogen compound solvents. More preferably, the solvent contains one or more selected from a solvent, an ester solvent, a nitrile solvent, a nitro solvent, and an aldehyde solvent. By using such a solvent, the above-described components can be dispersed sufficiently uniformly in the dispersoid 61 relatively easily.

  In addition, the dispersion 6 usually contains a colorant. Examples of the colorant that can be used include pigments and dyes. Examples of such pigments and dyes include carbon black, spirit black, lamp black (CI No. 77266), magnetite, titanium black, chrome lead, cadmium yellow, mineral fast yellow, navel yellow, and naphthol yellow S. , Hansa Yellow G, Permanent Yellow NCG, Chrome Yellow, Benzidine Yellow, Quinoline Yellow, Tartrazine Lake, Red Mouth Lead, Molybdenum Orange, Permanent Orange GTR, Pyrazolone Orange, Benzidine Orange G, Cadmium Red, Permanent Red 4R, Watching Red Calcium salt, eosin lake, brilliant carmine 3B, manganese purple, fast violet B, methyl violet lake, bitumen, cobalt blue, al Reblue Lake, Victoria Blue Lake, First Sky Blue, Indanthrene Blue BC, Ultramarine, Aniline Blue, Phthalocyanine Blue, Calco Oil Blue, Chrome Green, Chrome Oxide, Pigment Green B, Malachite Green Lake, Phthalocyanine Green, Final Yellow Green G, Rhodamine 6G, quinacridone, rose bengal (C.I. No. 45432), C.I. I. Direct Red 1, C.I. I. Direct Red 4, C.I. I. Acid Red 1, C.I. I. Basic Red 1, C.I. I. Modern Tread 30, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 184, C.I. I. Direct Blue 1, C.I. I. Direct Blue 2, C.I. I. Acid Blue 9, C.I. I. Acid Blue 15, C.I. I. Basic Blue 3, C.I. I. Basic Blue 5, C.I. I. Modern Blue 7, C.I. I. Pigment blue 15: 1, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 5: 1, C.I. I. Direct Green 6, C.I. I. Basic Green 4, C.I. I. Basic Green 6, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 180, C.I. I. Pigment Yellow 162, nigrosine dye (CI No. 50415B), metal complex dye, silica, aluminum oxide, magnetite, maghemite, various ferrites, cupric oxide, nickel oxide, zinc oxide, zirconium oxide, titanium oxide, Examples thereof include metal oxides such as magnesium oxide, and magnetic materials containing magnetic metals such as Fe, Co, and Ni, and one or more of these can be used in combination. Such a colorant is usually contained in the dispersoid 61 in the dispersion liquid 6.

  The content of the colorant in the dispersion 6 is not particularly limited, but is preferably 0.1 to 10 wt%, and more preferably 0.3 to 3.0 wt%. If the content of the colorant is less than the lower limit, it may be difficult to form a visible image having a sufficient density depending on the type of the colorant. On the other hand, when the content of the colorant exceeds the upper limit, the fixing characteristics and charging characteristics of the finally obtained toner may be deteriorated.

  Further, the dispersion 6 may contain wax. The wax is usually used for the purpose of improving releasability. Examples of such wax include plant waxes such as candelilla wax, carnauba wax, rice wax, cotton wax, and wood wax, animal waxes such as beeswax and lanolin, montan wax, ozokerite, and ceresin. Mineral waxes such as mineral waxes, paraffin waxes, microwaxes, microcrystalline waxes, petroleum waxes such as petrolatum waxes, Fischer-Tropsch waxes, polyethylene waxes (polyethylene resins), polypropylene waxes (polypropylene resins) ), Synthetic hydrocarbon waxes such as oxidized polyethylene wax and oxidized polypropylene wax, 12-hydroxy stearamide, stearamide, phthalic anhydride, chlorinated hydrocarbon Fatty acid amides, esters, ketones, synthetic wax wax such as ether and the like, can be used singly or in combination of two or more of them. Further, as the wax, a crystalline polymer resin having a lower molecular weight may be used. For example, a homopolymer or copolymer of polyacrylate such as poly n-stearyl methacrylate and poly n-lauryl methacrylate (for example, It is also possible to use a crystalline polymer having a long alkyl group in the side chain, such as an n-stearyl acrylate-ethyl methacrylate copolymer).

  The wax content in the dispersion 6 is not particularly limited, but is preferably 1.0 wt% or less, and more preferably 0.5 wt% or less. If the content of the wax is too large, the wax is liberated and coarsened in the finally obtained toner particles, and the toner seeps into the toner particle surface and the transfer efficiency of the toner tends to decrease. Indicates.

The softening point of the wax is not particularly limited, but is preferably 50 to 180 ° C, and more preferably 60 to 160 ° C.
Further, the dispersion 6 may contain components other than these. Examples of such components include emulsifying dispersants, charge control agents, magnetic powders, and the like. Among these, when the emulsifying dispersant is used, for example, the dispersibility of the dispersoid 61 in the dispersion 6 can be improved. Here, examples of the emulsifying dispersant include emulsifiers, dispersants, and dispersion aids.

  Examples of the dispersant include inorganic dispersants such as tricalcium phosphate, nonionic organic dispersants such as polyvinyl alcohol, carboxymethyl cellulose, and polyethylene glycol, metal tristearate (for example, aluminum salt), and metal distearate. Salt (eg, aluminum salt, barium salt, etc.), stearic acid metal salt (eg, calcium salt, lead salt, zinc salt, etc.), linolenic acid metal salt (eg, cobalt salt, manganese salt, lead salt, zinc salt, etc.) , Octanoic acid metal salts (eg, aluminum salts, calcium salts, cobalt salts, etc.), oleic acid metal salts (eg, calcium salts, cobalt salts, etc.), palmitic acid metal salts (eg, zinc salts, etc.), naphthenic acid metal salts (For example, calcium salt, cobalt salt, manganese salt, lead salt, zinc salt, etc.), Resin metal salt (example Calcium salt, cobalt salt, manganese lead salt, zinc salt, etc.), polyacrylic acid metal salt (eg, sodium salt), polymethacrylic acid metal salt (eg, sodium salt), polymaleic acid metal salt (eg, Sodium salts, etc.), anionic organic dispersants such as acrylic acid-maleic acid copolymer metal salts (eg, sodium salts), polystyrene sulfonic acid metal salts (eg, sodium salts), etc., cations such as quaternary ammonium salts Organic dispersants and the like. Among these, nonionic organic dispersants or anionic organic dispersants are particularly preferable.

The content of the dispersant in the dispersion 6 is not particularly limited, but is preferably 3.0 wt% or less, and more preferably 0.01 to 1.0 wt%.
Examples of the dispersion aid include anions, cations, and nonionic surfactants.
The dispersing aid is preferably used in combination with a dispersing agent. When the dispersion 6 contains a dispersant, the content of the dispersion aid in the dispersion 6 is not particularly limited, but is preferably 2.0 wt% or less, and is 0.005 to 0.5 wt%. Is more preferable.

Examples of the charge control agent include a metal salt of benzoic acid, a metal salt of salicylic acid, a metal salt of alkyl salicylic acid, a metal salt of catechol, a metal-containing bisazo dye, a nigrosine dye, a tetraphenylborate derivative, a quaternary ammonium salt, Examples thereof include alkyl pyridinium salts, chlorinated polyesters, and nitrohumic acid.
Examples of the magnetic powder include magnetite, maghemite, various ferrites, cupric oxide, nickel oxide, zinc oxide, zirconium oxide, titanium oxide, magnesium oxide, and other metal oxides such as Fe, Co, and Ni. The thing comprised with the magnetic material containing a magnetic metal etc. are mentioned.

In addition to the above materials, for example, zinc stearate, zinc oxide, cerium oxide or the like may be added to the dispersion liquid 6.
In addition, components other than the dispersoid 61 may be dispersed in the dispersion 6 as insoluble matters. For example, in the dispersion 6, inorganic fine powders such as silica, titanium oxide, and iron oxide, organic fine powders such as fatty acids and fatty acid metal salts, and the like may be dispersed.

Although the average particle diameter of the dispersoid 61 in the dispersion liquid 6 is not specifically limited, It is preferable that it is 0.5-9 micrometers, and it is more preferable that it is 0.5-5 micrometers.
The content of the dispersoid 61 in the dispersion 6 is not particularly limited, but is preferably 1 to 99 wt%, more preferably 5 to 95 wt%.
In the dispersion 6, the dispersoid 61 may be in a solid form, in a liquid form, or may coexist. That is, the dispersion 6 may be a suspension or an emulsion.

  When the dispersoid 61 is liquid (for example, in a solution state or a molten state), the average particle diameter of the dispersoid 61 finely dispersed in the dispersion medium 62 is relatively easily set to a value in the above range. can do. Further, when the dispersoid 61 is in a liquid form, variation in shape and size between the dispersoids 61 can be made particularly small, so that the finally obtained toner is between the toner particles. The variation in shape and size is particularly small.

  On the other hand, when the dispersoid 61 is solid, unnecessary components such as a solvent can be effectively prevented from remaining in the finally obtained toner. As a result, the reliability of the toner is particularly excellent. When the dispersoid 61 is solid, that is, when the dispersion 6 is a suspension, for example, the suspension as the dispersion 6 is prepared via an emulsion. There may be. Thereby, the advantage in the case where the dispersoid 61 is in a liquid state is also effectively exhibited while sufficiently exhibiting the advantage in the case where the dispersoid 61 is in a solid state as described above.

  Further, when the dispersion 6 is an emulsion (emulsion), the dispersion 6 is an O / W emulsion, that is, a liquid having a low solubility in water in the aqueous dispersion medium 62. The dispersoid 61 is preferably dispersed. As a result, a toner having a small variation in shape and size between the particles can be stably produced. Further, by using an aqueous liquid as the dispersion medium 62, it is possible to reduce the volatilization amount of the organic solvent in the transport unit 3 of the toner manufacturing apparatus 1 as described later or to substantially not volatilize the organic solvent. . As a result, the toner can be manufactured by a method that hardly causes adverse effects on the environment.

The dispersion 6 as described above can be prepared using, for example, the following method (first method).
First, an aqueous solution in which a dispersant and / or a dispersion medium is added to water or a liquid excellent in compatibility with water (water-soluble liquid) as necessary is prepared.
On the other hand, a resin liquid containing a resin as a main component of the toner or a precursor thereof (hereinafter collectively referred to as “resin material”) is prepared. For the preparation of the resin liquid, for example, the above-described solvent may be used in addition to the resin material. The resin liquid may be a molten liquid obtained by heating a resin material.

  Next, the dispersion liquid 6 in which the dispersoid 61 containing the resin material is dispersed in the aqueous dispersion medium 62 is obtained by adding the resin liquid while gradually dropping into the stirred aqueous solution. can get. By preparing the dispersion 6 by such a method, the circularity of the dispersoid 61 in the dispersion 6 can be further increased. As a result, the finally obtained toner particles have a particularly high degree of circularity and a particularly small variation in shape between the particles. In addition, when dripping a resin liquid, you may heat an aqueous solution and / or a resin liquid. In addition, when a solvent is used for the preparation of the resin liquid, for example, after the dropwise addition as described above, the obtained dispersion liquid 6 is heated or placed in a reduced-pressure atmosphere or the like in the dispersoid 61. You may remove at least one part of the solvent contained. For example, the dispersion 6 can be obtained as a suspension by removing most of the solvent contained in the dispersoid 61.

As mentioned above, although the example of the preparation method of the dispersion liquid 6 was demonstrated, the dispersion liquid is not limited to what was prepared by such a method. For example, the dispersion liquid 6 can also be prepared by the following method (second method).
First, an aqueous solution is prepared by adding a dispersant and / or a dispersion medium as necessary to water or a liquid having excellent compatibility with water.
On the other hand, a powdery or granular material containing a resin material is prepared.
Next, a dispersion liquid in which the dispersoid 61 containing the resin material is dispersed in the aqueous dispersion medium 62 by gradually adding the powdery or granular material into the stirred aqueous solution. 6 is obtained. When the dispersion liquid 6 is prepared by such a method, the organic solvent can be substantially prevented from volatilizing in the transport unit 3 of the toner manufacturing apparatus 1 as described later. As a result, the toner can be manufactured by a method that hardly causes adverse effects on the environment. In addition, when adding the said material, you may heat an aqueous solution, for example.

The dispersion 6 can also be prepared by the following method (third method).
First, a resin dispersion in which at least a resin material is dispersed and a colorant dispersion in which at least a colorant is dispersed are prepared.
Next, the resin dispersion and the colorant dispersion are mixed and stirred. At this time, if necessary, an aggregating agent such as an inorganic metal salt may be added while stirring.
By stirring for a predetermined time, an aggregate in which the resin material, the colorant and the like are aggregated is formed. As a result, a dispersion 6 in which the aggregate is dispersed as the dispersoid 61 is obtained.

  In the method for preparing a dispersion as described above, a kneaded material containing a resin material (binder resin) may be used. That is, as the “resin material” in the first method and the third method described above, a kneaded material containing a resin material may be used, or as the “powdered or granular material” in the second method, A kneaded material containing a resin material may be used. Thereby, for example, toner particles can be obtained as a mixture in which each constituent component is more uniformly mixed. In particular, even when the toner includes two or more components having poor dispersibility and compatibility, the above-described effects can be obtained. In addition, as a kneaded material, what contains components (for example, components, such as a coloring agent, a wax, a charge control agent) other than a resin component, for example can be used. Thereby, the above effects become more remarkable.

  Further, for example, the method described in Japanese Patent Application No. 2003-113428 may be applied to the preparation of the dispersion liquid 6. That is, a liquid containing a powdered or granular resin material (kneaded material) is ejected from a plurality of nozzles, the liquids ejected from the nozzles collide with each other, and the resin material (kneaded material) is atomized to form fine particles. A method of obtaining the dispersion 6 containing the dispersed dispersoid 61 may be applied. Thereby, the size of the dispersoid 61 contained in the dispersion liquid 6 can be easily made relatively small (the size in the above-described range), and the dispersion of the sizes of the dispersoids 61 can be easily achieved. Can be reduced.

  Further, it is preferable that the dispersion 6 obtained by the above method is subjected to a deaeration process (subjected to a deaeration process) before being used for discharge in the toner manufacturing apparatus 1 described later. Thereby, the dissolved amount of gas in the dispersion liquid 6 can be reduced, and when the dispersion medium 62 is removed from the droplet 6A of the discharged dispersion liquid 6 in the transport unit 3 of the toner manufacturing apparatus 1 described later. Thus, it is possible to effectively prevent bubbles and the like from being generated in the droplet 6A. As a result, it is possible to effectively prevent toner particles having irregular shapes (hollow particles, missing particles, etc.) from being mixed into the finally obtained toner. Therefore, it is possible to easily and reliably obtain a toner in which each toner particle has a uniform shape and a narrow particle size distribution. Thereby, the finally obtained toner can be made particularly excellent in properties such as transferability, fluidity, and cleaning properties. Further, by subjecting the dispersion liquid 6 to deaeration treatment, the ratio of pores (voids) in the finally obtained toner particles can be reduced. As a result, the reliability of the toner is further improved.

The method of deaeration treatment is not particularly limited, and for example, a method of applying ultrasonic vibration to the dispersion (ultrasonic vibration method), a method of placing the dispersion in a reduced-pressure atmosphere (decompression method), or the like can be used. .
When the decompression method is used as the degassing method, the pressure of the atmosphere in which the dispersion is placed is preferably 80 kPa or less, more preferably 0.1 to 40 kPa, and further preferably 1 to 27 kPa. preferable. If the atmospheric pressure during the degassing treatment is within this range, the dissolved gas can be efficiently removed while maintaining the shape of the dispersoid 61 in the dispersion 6 sufficiently.

[Toner production equipment]
Next, a toner manufacturing apparatus used in the toner manufacturing method in the present embodiment will be described.
FIG. 1 is a longitudinal sectional view schematically showing an embodiment of a toner manufacturing apparatus used for manufacturing the toner of the present invention. FIG. 2 is an enlarged sectional view of the vicinity of the head portion of the toner manufacturing apparatus shown in FIG. These are sectional drawings which show typically the dispersoid in which the aggregation prevention layer was formed.

The toner manufacturing apparatus 1 includes a plurality of head units 2 that discharge the dispersion liquid 6 (particularly, the dispersion liquid 6 that has been deaerated), and a dispersion liquid supply that supplies the dispersion liquid 6 to each head unit 2. Unit 4, transport unit 3 that transports the dispersion liquid 6 ejected from the head unit 2, and layer formation liquid supply that sprays a layer formation liquid as will be described later onto the ejected liquid dispersion 6. Means 141 and a collection unit 5 for collecting the produced resin fine particles 9 (hereinafter also referred to as toner) are provided. Such a toner manufacturing apparatus 1 discharges the dispersion liquid 6 from the head unit 2 to form droplets 6A (hereinafter also referred to as a droplet formation process), and the transport unit 3 removes the dispersion medium 61 from the droplets 6A. The resin fine particles 9 made of the fine particles derived from one dispersoid 61 are obtained (hereinafter also referred to as a dispersion medium removing step).
Hereinafter, the operation of the toner manufacturing apparatus 1, that is, the method for manufacturing resin fine particles of the present invention will be described together with each configuration of the toner manufacturing apparatus 1.

A dispersion liquid 6 in which a dispersoid 61 is finely dispersed in a dispersion medium 62 is stored in the dispersion liquid supply section 4, and the dispersion liquid 6 is sent to the head section 2. The constituent materials of the dispersion 6 will be described in detail later.
The dispersion supply unit 4 may have any function as long as it has a function of supplying the dispersion 6 to the head unit 2. In the present embodiment, the dispersion supply unit 4 includes a stirring unit 41 that stirs the dispersion 6 as illustrated. Yes. That is, the dispersion 6 before discharge is accommodated in the dispersion supply unit 4 having a stirring function, and is supplied from the dispersion supply unit 4 to the head unit 2. Thereby, for example, even if the dispersoid 61 is difficult to disperse in the dispersion medium, the dispersion 6 in which the dispersoid 61 is sufficiently uniformly dispersed can be supplied into the head unit 2.

As shown in FIG. 2, each head unit 2 includes a dispersion liquid storage unit 21 that receives the supply of the dispersion liquid 6 from the dispersion liquid supply unit 4 as described above, and a piezoelectric for changing the internal pressure of the dispersion liquid storage unit 21. It has the element 22 and the nozzle 23 connected to the dispersion liquid storage part 21.
The dispersion liquid storage unit 21 stores the dispersion liquid 6 from the dispersion liquid supply unit 4. Further, a part of the dispersion liquid storage unit 21 is partitioned by the diaphragm 24, and the piezoelectric element 22 is provided on the diaphragm 24.

As shown in FIG. 2, the piezoelectric element 22 includes a lower electrode (first electrode) 221, a piezoelectric body 222, and an upper electrode (second electrode) 223 that are stacked in this order. In other words, in the piezoelectric element 22, the piezoelectric body 222 is interposed between the upper electrode 223 and the lower electrode 221.
The piezoelectric element 22 has a function of instantaneously increasing the internal pressure of the dispersion liquid storage unit 21 by vibrating (displacement) the diaphragm 24. Therefore, the dispersion 6 stored in the dispersion storage unit 21 is discharged from the nozzle 23 to the transport unit 3 by the pressure pulse (piezoelectric pulse) of the piezoelectric element 22.

  More specifically, the head unit 2 is in a state where a predetermined ejection signal is not input from a piezoelectric element driving circuit (not shown), that is, between the lower electrode 221 and the upper electrode 223 of the piezoelectric element 22. In a state where no voltage is applied, the piezoelectric body 222 is not deformed. For this reason, the diaphragm 24 is not deformed and the volume of the dispersion liquid storage unit 21 is not changed. Therefore, the dispersion 6 is not discharged from the nozzle 23.

  On the other hand, in a state where a predetermined ejection signal is input from the piezoelectric element driving circuit, that is, in a state where a predetermined voltage is applied between the lower electrode 221 and the upper electrode 223 of the piezoelectric element 22, the piezoelectric body 222 is deformed. Arise. As a result, the diaphragm 24 is greatly deflected (bends downward in FIG. 2), and the volume of the dispersion liquid storage unit 21 is reduced (changed). At this time, the pressure in the dispersion liquid storage unit 21 instantaneously increases, and the granular dispersion liquid 6 is ejected from the nozzle 23 to form droplets 6A.

  When the discharge of one dispersion 6 is completed, that is, when the formation of one droplet 6A is completed, the piezoelectric element driving circuit stops applying the voltage between the lower electrode 221 and the upper electrode 223. Thereby, the piezoelectric element 22 returns almost to its original shape, and the volume of the dispersion liquid storage unit 21 increases. At this time, pressure (pressure in the positive direction) from the dispersion liquid supply unit 4 toward the nozzle 23 acts on the dispersion liquid 6. For this reason, air is prevented from entering the dispersion liquid storage part 21 from the nozzle 23, and an amount of the dispersion liquid 6 corresponding to the discharge amount of the dispersion liquid 6 is supplied from the dispersion liquid supply part 4 to the dispersion liquid storage part 21. .

By applying the voltage as described above at a predetermined cycle, the piezoelectric element 22 vibrates and the droplet 6A is repeatedly formed.
In this manner, by performing the discharge of the dispersion liquid 6 by the pressure pulse generated by the vibration of the piezoelectric body 222, the dispersion liquid 6 can be intermittently discharged one by one, and the shape of the droplet 6A is stabilized.

Moreover, by discharging the dispersion liquid as described above, the frequency of the piezoelectric body, the nozzle opening area (nozzle diameter), the temperature and viscosity of the dispersion liquid, the discharge amount of one drop of the dispersion liquid, The content of the dispersoid occupying, the particle size of the dispersoid in the dispersion can be controlled relatively accurately, and the toner to be manufactured can be easily controlled to a desired shape and size. Further, by controlling these conditions and the like, for example, the production amount of toner and the like can be easily and reliably managed.
Further, by using the vibration of the piezoelectric body for discharging the dispersion liquid, the dispersion liquid can be discharged more reliably at a predetermined interval. For this reason, it can prevent effectively that the droplet 6A of the formed dispersion liquid 6 collides and aggregates, and can prevent formation of irregularly shaped powder more effectively.

  The initial velocity of the dispersion 6 discharged from the head unit 2 to the transport unit 3 is, for example, preferably 0.1 to 10 m / sec, and more preferably 2 to 8 m / sec. When the initial speed of the dispersion 6 is less than the lower limit, the productivity of the resin fine particles 9, that is, the productivity of the toner is lowered. On the other hand, when the initial velocity of the dispersion liquid 6 exceeds the upper limit, the sphericity of the finally obtained toner particles tends to decrease.

  Moreover, the viscosity of the dispersion 6 discharged from the head part 2 is not particularly limited, but is preferably 0.5 to 200 [mPa · s], for example, 1 to 25 [mPa · s]. Is more preferable. When the viscosity of the dispersion liquid 6 is less than the lower limit, it is difficult to sufficiently reduce the variation in the size of the formed droplets 6A, and the dispersion of finally obtained toner particles may increase. . On the other hand, when the viscosity of the dispersion liquid 6 exceeds the upper limit, the diameter of the formed droplet 6A increases, the discharge speed of the dispersion liquid 6 decreases, and the amount of energy required for discharging the dispersion liquid 6 also increases. Show the trend. In addition, when the viscosity of the dispersion liquid 6 is particularly large, the dispersion liquid 6 cannot be discharged as droplets.

It is preferable to discharge the dispersion 6 from the head unit 2 at a temperature not higher than the glass transition point of the dispersoid 61. This makes it difficult for the dispersoids 61 to stick to each other when forming the droplets 6A of the dispersion liquid 6, so that the fine particles derived from the dispersoids 61 can be prevented from being joined to each other.
Further, the temperature of the dispersion 6 discharged from the head unit 2 is not particularly limited, but is preferably lower than the temperature in the transport unit 3 (the processing temperature in the dispersion medium removing step) described in detail later. Thereby, it is possible to effectively prevent the dispersion liquid 6 from solidifying unintentionally due to the volatilization of the dispersion medium 62 from the dispersion liquid 6 immediately after discharge. Specifically, in the vicinity of the nozzle 23, effectively preventing the nozzle 23 from being clogged by volatilization of the dispersion medium 62 from the dispersion 6 before discharging (before running out of liquid). Can do. In particular, the temperature of the dispersion liquid 6 (dispersion liquid 6 in the head section 2) discharged from the head section 2 is T ₀ [° C.], and the temperature in the transport section 3 described in detail later (processing temperature in the dispersion medium removing step). ) Is T ₁ [° C.], it is preferable to satisfy the relationship of −5 ≦ T ₁ −T ₀ ≦ 60, and more preferably satisfy the relationship of −5 ≦ T ₁ −T ₀ ≦ 50, It is more preferable that the relationship of 5 ≦ T ₁ −T ₀ ≦ 40 is satisfied. By satisfying such a relationship, the above-described effects can be made more remarkable.

  The dispersion 6 discharged from the head unit 2 may be preheated (particularly, heated to a temperature equal to or lower than the temperature in the transport unit 3 described in detail later). By heating the dispersion 6 in this manner, for example, even if the dispersoid 61 is in a solid state (or a relatively high viscosity state) at room temperature, the dispersoid is in a molten state (or in discharge). (Viscosity is relatively low, softened state). As a result, the circularity of the dispersoid 61 contained in the droplet 6A is particularly high in the transport unit 3 described later, and as a result, the finally obtained toner particles may have a high circularity. it can.

  Further, the discharge amount of one droplet of the dispersion 6, that is, the average volume of the droplet 6 </ b> A is slightly different depending on the content of the dispersoid 61 in the dispersion 6, but is preferably 0.05 to 100 pl. More preferably, it is 0.5-5pl. By setting the discharge amount of one droplet of the dispersion 6 to a value in such a range, it is possible to stably form the droplet 6A while suppressing variations in the particle diameter of the droplet 6A of the dispersion 6. As a result, it is possible to more effectively suppress variations in the particle diameter of the obtained resin fine particles 9.

  The frequency (frequency of the piezoelectric pulse) of the piezoelectric element 22 is not particularly limited, but is preferably 1 kHz to 500 MHz, and more preferably 5 kHz to 200 MHz. When the vibration frequency of the piezoelectric element 22 is less than the lower limit value, toner productivity decreases. On the other hand, when the vibration frequency of the piezoelectric element 22 exceeds the upper limit, the discharge of the granular dispersion liquid 6 cannot follow, and there is a possibility that the dispersion of the size of one drop of the dispersion liquid 6 becomes large.

  Each head unit 2 may discharge the dispersion 6 almost simultaneously, but it is preferable that at least two adjacent head units are controlled so that the discharge timing of the dispersion 6 is different. . Thereby, it is possible to more effectively prevent the granular dispersions 6 discharged from the adjacent head portions 2, that is, the droplets 6 </ b> A, from colliding before becoming the resin fine particles 9 and aggregating them. it can.

The shape of the nozzle 23 is not particularly limited, but is preferably substantially circular. As a result, the sphericity of the discharged dispersion liquid 6, the resin fine particles 9 formed in the transport unit, and finally the toner particles obtained can be increased.
When the nozzle 23 has a substantially circular shape, the diameter (nozzle diameter) is, for example, preferably 5 to 500 μm, and more preferably 10 to 200 μm. If the diameter of the nozzle 23 is less than the lower limit value, clogging is likely to occur, and the dispersion of the size of the discharged dispersion liquid 6 may increase. On the other hand, when the diameter of the nozzle 23 exceeds the upper limit, the discharged dispersion 6 may embed bubbles due to the force relationship between the negative pressure of the dispersion reservoir 21 and the surface tension of the nozzle. There is.

On the other hand, when the diameter of the nozzle 23 is less than the lower limit value, clogging is likely to occur, and the dispersion of the discharged dispersion liquid 6, that is, the droplet 6A, may increase in size. On the other hand, if the diameter of the nozzle 23 exceeds the upper limit, the droplet 6A may embed bubbles depending on the force relationship between the negative pressure of the dispersion liquid storage unit 21 and the surface tension of the nozzle 23. .
Further, the vicinity of the nozzle 23 of the head portion 2 (particularly, the inner surface of the opening of the nozzle 23 and the surface on the side where the nozzle 23 of the head portion 2 is provided (the lower surface in the drawing)) It preferably has liquid repellency. Thereby, it can prevent effectively that the dispersion liquid 6 adheres to nozzle vicinity. As a result, it is possible to effectively prevent a so-called poor liquid runout or a discharge failure of the dispersion 6. Further, by effectively preventing the dispersion liquid 6 from adhering to the vicinity of the nozzle, the stability of the shape of the ejected droplets is improved (the variation in shape and size between the droplets is reduced). ) Variation in the shape and size of the toner particles finally obtained is also reduced.

Examples of such a material having liquid repellency include fluorine resins such as polytetrafluoroethylene (PTFE), silicone materials, and the like.
In addition, the vicinity of the nozzle 23 of the head portion 2 (particularly, the inner surface of the opening of the nozzle 23 and the surface of the head portion 2 where the nozzle 23 is provided (the lower surface in the figure)) is subjected to a hydrophobic treatment. It is preferable. Thereby, for example, when the dispersion medium 62 of the dispersion 6 is mainly composed of water, the above-described liquid repellency can be more suitably exhibited, and the above effects are more remarkable. Appears as something. Examples of the hydrophobic treatment method include formation of a film made of a hydrophobic material (for example, the above-described material having liquid repellency). By the way, water has a relatively high viscosity among various liquids. However, even if such water is used as a constituent material of the dispersion medium 62, there is a disadvantage in that the dispersion 6 adheres to the vicinity of the nozzle. Generation is effectively prevented. Therefore, when the hydrophobic treatment is performed in the vicinity of the nozzle 23 of the head part 2, the dispersion liquid 6 substantially not containing or hardly containing an organic solvent can be suitably used, which has an adverse effect on the environment. The toner can be produced by a method that is extremely difficult to impart the toner.

A gas injection port 7 is provided between the head portions 2 as described above, and a gas flow supply means 10 is provided in the gas injection port 7 via a duct 101 as shown in FIG. It is connected.
As shown in FIG. 2, the gas supply means 10 injects gas with a substantially uniform pressure from each gas injection port 7 provided between the head portion 2 and the head portion 2 via the duct 101. ing. Thereby, the droplet 6A can be conveyed and the resin fine particles 9 can be obtained while maintaining the interval of the granular dispersion 6 discharged intermittently from the nozzle 23. As a result, collision and aggregation of the droplets 6A are more effectively prevented.

In addition, by injecting the gas supplied from the gas flow supply means 10 from the gas injection port 7, it is possible to form an airflow that flows in substantially one direction (downward in the drawing) in the transport unit 3. When such an air flow is formed, the granular dispersion 6 (resin fine particles 9) in the transport unit 3 can be transported more efficiently.
A heat exchanger 11 is attached to the gas flow supply means 10. Thereby, the temperature of the gas injected from the gas injection port 7 can be set to a preferable value, and the granular dispersion 6 discharged to the transport unit 3 is efficiently solidified, that is, the dispersion medium 62 is removed from the droplet 6A. It can be removed efficiently.
In addition, such a gas flow supply means 10 can easily control the speed of removing the dispersion medium 62 from the droplets 6A by adjusting the supply amount of the air flow.

  Although the temperature of the gas injected from the gas injection port 7 varies depending on the composition of the dispersoid 61 and the dispersion medium 62 contained in the dispersion 6, it is usually preferably 0 to 70 ° C., and 15 to 60 ° C. It is more preferable that When the temperature of the gas ejected from the gas ejection port 7 is in such a range, the dispersion medium 62 is efficiently produced from the droplet 6A while preventing unintentional modification of the resin constituting the resin fine particles 9 to be obtained. As a result, the toner productivity can be made particularly excellent.

  Moreover, the humidity of the gas injected from the gas injection port 7 is preferably 50% RH or less, and more preferably 30% RH or less, for example. When the humidity of the gas ejected from the gas ejection port 7 is 50% RH or less, it becomes possible to efficiently remove the dispersion medium 62 from the droplets 6A of the dispersion 6 in the transport unit 3 described later, and the resin fine particles 9 (toner) productivity is further improved.

3 is formed on the surface of the dispersoid 61 in the dispersion 6 (droplet 6A) discharged as described above (see FIG. 3). Aggregation prevention layer forming step).
By forming such an agglomeration preventing layer 14, each of the fine particles derived from the dispersoid 61 can be made into resin fine particles (toner particles) 9 in a dispersion medium removing step described later. Since the resin fine particles 9 thus obtained are not aggregates of fine particles, they have excellent mechanical strength. Further, since the resin fine particles 9 are not obtained as an aggregate of fine particles, generation of particles having hollow portions (hollow particles) or irregularly shaped particles can be prevented. As a result, it is possible to efficiently produce resin fine particles 9 having a uniform shape and a small width of particle size distribution. Moreover, since it is not necessary to melt and bond the fine particles derived from the dispersoid 61 at a high temperature in order to obtain mechanical strength, unintentional modification of the resin constituting the resin fine particles 9 can be prevented.

In the present embodiment, the aggregation preventing layer 14 is formed as follows.
As shown in FIG. 1, a layer forming liquid 15 in which a material (layer forming material) 14 ′ for forming an aggregation preventing layer 14 is finely dispersed in the discharged dispersion 6 (droplet 6A) is formed into a layer. Spray from the liquid supply means 141 for use. Thereby, layer formation material 14 'can be more easily given to droplet 6A.

The layer forming material 14 ′ applied to the droplet 6A adheres to the surface of the dispersoid 61 and forms the aggregation preventing layer 14 as shown in FIG.
Thus, after discharging the dispersion liquid 6, the specific gravity of the dispersoid 61 to be the resin fine particles and the layer forming material 14 ′ is greatly different by forming the aggregation preventing layer 14 on the surface of the dispersoid 61. Even in this case, the layer forming material 14 ′ can be uniformly applied to the surface of the dispersoid 61, and the aggregation preventing layer 14 can be formed more uniformly. Further, since it is not necessary to consider the specific gravity of the layer forming material 14 ′, the selection range of the layer forming material 14 ′ is widened.

  The layer forming liquid 15 has a configuration in which the layer forming material 14 ′ is finely dispersed in a dispersion medium (layer forming material dispersion medium). By using such a layer forming liquid 15, the layer forming material 14 'can be efficiently applied to the droplets 6A. Further, since both the droplet 6A and the layer forming liquid 15 are liquid, they are easily mixed, and the layer forming material 14 'can be uniformly applied to the entire droplet 6A.

Examples of the layer forming material 14 ′ include silica, aluminum oxide, titanium oxide, strontium titanate, cerium oxide, magnesium oxide, chromium oxide, titania, zinc oxide, alumina, magnetite and other metal oxides, and nitride nitride such as silicon nitride. Composed of inorganic materials such as carbides, carbides such as silicon carbide, calcium sulfate, calcium carbonate, aliphatic metal salts, organic materials such as acrylic resin, fluororesin, polystyrene resin, polyester resin, aliphatic metal salt And fine particles composed of these composites, and one or more of these can be used in combination.
Among the above, it is preferable to use a fluororesin as the aggregation preventing layer forming material 14 ′. Thereby, aggregation of dispersoid 61 can be prevented more reliably.

Examples of the fluororesin include polytetrafluoroethylene (PTFE), polytetrafluoroethylene-perfluoroalkoxy-ethylene copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), ethylene- Tetrafluoroethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF) and the like. These can be used alone or in combination of two or more.
Among the above-mentioned, it is preferable to use polytetrafluoroethylene as the fluororesin. As a result, the effect of preventing aggregation of the dispersoid 61 becomes more remarkable. Moreover, since this polytetrafluoroethylene is excellent in handleability, it can be suitably used as the aggregation preventing layer forming material 14 '.

  The layer forming material dispersion medium is not particularly limited as long as it can disperse the layer forming material 14 ′. For example, the layer forming material dispersion medium may be the same as the dispersion medium 62 constituting the dispersion 6. Can do. As a result, the sprayed layer forming liquid 15 and the droplet 6A are easily mixed. As a result, the layer forming material 14 ′ can be uniformly attached to the surface of the dispersoid 61, and the aggregation preventing layer can be more efficiently applied. 14 can be formed.

  Further, when the dispersion medium 62 is composed of an aqueous liquid, for example, water and / or a liquid having excellent compatibility with water is used as the layer forming material dispersion medium. The forming liquid 15 is mixed more efficiently, and as a result, a more uniform aggregation preventing layer 14 can be easily formed. Furthermore, alcohols such as methanol and ethanol may be appropriately added to water and / or a liquid having excellent compatibility with water. When such alcohols are contained, when the layer forming liquid 15 is applied to the droplet 6A, the layer forming liquid 15 spreads on the surface of the droplet 6A, and the entire alcohol concentration is made uniform. Due to the action of the liquid to be converted, the layer forming material 14 ′ is more quickly dispersed and more uniformly adheres to the surface of the dispersoid 61. As a result, a more uniform aggregation preventing layer 14 can be efficiently formed.

  The application of the layer forming material 14 ′ (layer forming liquid 15) may be performed, for example, by providing a cooled region (cooling region) in the vicinity of the head portion 2 and in the cooling region. As a result, the layer forming material 14 ′ can be applied to the discharged dispersion liquid 6 before the substantial removal of the dispersion medium 62 is started, so that the dispersoid 61 can be more reliably prevented from agglomerating. be able to. In addition, it is preferable that the atmospheric temperature of this cooling area | region is about 10-35 degreeC, and it is more preferable that it is about 20-25 degreeC.

When the average particle diameter of the layer forming material 14 ′ in the layer forming liquid 15 is Dc [μm] and the average particle diameter of the dispersoid 61 is Dm [μm], 1 × 10 ⁻³ ≦ Dc / Dm ≦ 1 × The relationship of 10 ⁻¹ is preferably satisfied, and the relationship of 5 × 10 ⁻³ ≦ Dc / Dm ≦ 2 × 10 ⁻² is more preferable. By satisfying such a relationship, the aggregation preventing layer 14 can be reliably formed on the surface of the dispersoid 61, and the dispersoids 61 in the droplet 6A can be effectively prevented from aggregating with each other. it can. The fine particles derived from the dispersoid 61 can be made into the resin fine particles 9 more reliably. As a result, resin fine particles having excellent mechanical strength and a uniform shape can be obtained.

  Specifically, the layer forming material 14 ′ in the layer forming liquid 15 is preferably 0.02 to 1.0 μm, and more preferably 0.1 to 1.0 μm. Thereby, the aggregation preventing layer 14 can be reliably formed on the surface of the dispersoid 61, and the dispersoids 61 in the droplets 6A can be effectively prevented from aggregating with each other. The fine particles derived from the dispersoid 61 can be made into the resin fine particles 9 more reliably. As a result, resin fine particles having excellent mechanical strength and a uniform shape can be obtained.

  The layer forming liquid 15 is preferably sprayed so that the content of the layer forming material 14 ′ in the finally obtained resin fine particle 9 powder is about 0.1 to 1.0 wt%. It is more preferable to spray the layer forming liquid 15 so as to be about ˜0.8 wt%. Thus, the function of the resin fine particles 9 finally obtained can be sufficiently exhibited while more reliably preventing the dispersoids 61 in the droplets 6A from aggregating. In addition, aggregation in the finally obtained toner (resin fine particle) powder can be prevented, and the storage stability of the toner is improved.

  Further, when the average particle diameter of the discharged droplet 6A is Dd [μm] and the average particle diameter of the dispersoid 61 is Dm [μm], the relationship of 0.5 <Dm / Dd <1.0 is satisfied. It is preferable that the relationship is satisfied, and it is more preferable that the relationship of 0.7 <Dm / Dd <0.9 is satisfied. Thereby, it is possible to prevent two or more dispersoids 61 from being included in the discharged droplet 6A. As a result, the formed droplet 6A may include one dispersoid 61 in the dispersion medium 62 or may be substantially composed of only the dispersion medium 62 without the dispersoid 61. . Thereby, it is possible to more reliably prevent the dispersoids 61 from aggregating with each other, and to obtain resin fine particles having excellent mechanical strength and a uniform shape.

The average particle diameter Dd of the droplets 6A is preferably 1 to 9 μm, and more preferably 1 to 7 μm. As a result, it is possible to stably form the droplet 6A while suppressing variation in the particle diameter of the droplet 6A of the dispersion liquid 6. As a result, it is possible to more effectively suppress variations in the particle diameter of the obtained resin fine particles 9.
Further, the standard deviation of the average particle diameter Dd of the droplets 6A is preferably 1.0 μm or less, and more preferably 0.8 μm or less. Thereby, the dispersion | variation in the particle size of the resin fine particle 9 obtained can be suppressed more effectively.

The droplet 6A including the dispersoid 61 in which the aggregation preventing layer 14 is formed as described above is removed from the disperse medium 62 while being transported through the transport unit 3, so that the resin fine particles composed of the fine particles derived from the dispersoid 61 are obtained. 9 When the dispersoid 61 contains a solvent as described above, the solvent is usually removed by the transport unit 3.
In particular, in the present invention, when the dispersion medium is removed, since the aggregation preventing layer is formed on the surface of the dispersoid, the aggregation of the dispersoid contained in the liquid dispersion is prevented, and as a result, A plurality of resin fine particles corresponding to fine particles derived from individual dispersoids are obtained. That is, one resin fine particle is obtained as one composed of fine particles derived from one dispersoid. Therefore, only by making the dispersoid have a uniform shape and a small width of the particle size distribution, the obtained resin fine particles can also have a uniform shape and a small width of the particle size distribution.

In addition, since the resin fine particles are obtained as one fine particle derived from one dispersoid rather than the resin fine particles as an aggregate, the resin fine particles can be made excellent in mechanical strength.
Further, since the resin fine particles are not obtained as aggregates, resin fine particles having excellent mechanical strength can be obtained without exposing the fine particles derived from the dispersoid to a temperature higher than the melting point. Moreover, since it is not necessary to expose the fine particles derived from the dispersoid to a temperature equal to or higher than the melting point, unintentional modification of the resin constituting the resin fine particles can be prevented.
Further, since the resin fine particles can be obtained as fine particles derived from a single dispersoid, the dispersion medium can be quickly removed from the discharged dispersion liquid without exposing the discharged dispersion liquid to a high temperature, and hollow. Generation of particles and irregularly shaped particles can be prevented.

The transport unit 3 includes a cylindrical housing 31.
During the production of the toner, the inside of the housing 31 is preferably maintained at a temperature within a predetermined range. As a result, variations in characteristics among the toner particles (resin fine particles 9) due to differences in manufacturing conditions can be reduced, and the reliability of the entire toner is improved. Further, for example, the inside of the housing 31 may have a plurality of regions having different temperatures in the longitudinal direction (dispersion liquid 6 and resin fine particle transport direction). As a result, the dispersion medium 62 is more smoothly removed while improving the productivity of the resin fine particles 9 (toner particles) while preventing unintentional modification of the resin constituting the resin fine particles 9 (toner particles). Can do.

As described above, for the purpose of keeping the temperature in the housing 31 within a predetermined range, for example, a heat source or a cooling source is installed inside or outside the housing 31, or a flow path for the heat medium or the cooling medium is formed in the housing 31. It is good also as a made jacket.
Further, the temperature in the transport unit 3 (treatment temperature in the dispersion medium removing step) is preferably set to a temperature lower than the boiling point of the dispersion medium 62, and is set to a temperature not higher than the glass transition point of the resin material constituting the dispersoid 61. Is preferred. Thereby, in the transport unit 3 (dispersion medium removing step), the dispersion medium 62 can be efficiently removed while preventing the fine particles derived from the dispersoid 61 from joining and aggregating more effectively. The uniformity and stability of the shape of the resin fine particles 9 to be obtained can be made sufficiently high. As a result, it is possible to obtain resin fine particles with less variation in shape and size between the particles, and to produce resin fine particles with high sphericity (geometrically perfect sphere shape). Can be made relatively easy.

  When the dispersoid 61 is composed of a plurality of types of resin materials (resin components), that is, when the dispersoid 61 includes a plurality of types of resin materials, the temperature in the transport unit 3 (in the dispersion medium removing step). The processing temperature is preferably equal to or lower than the glass transition point of the resin material constituting the main component in the dispersoid 61, and more preferably equal to or lower than the glass transition point of all the resin components constituting the dispersoid 61. As a result, it is possible to more reliably prevent the generation of irregularly shaped resin fine particles, particularly hollow particles, and as a result, obtain resin fine particles with even smaller variations in shape and size between the particles. it can.

  Specifically, the temperature in the transport unit 3 (treatment temperature (atmosphere temperature) in the dispersion medium removing step) varies depending on the composition of the dispersoid 61 and the dispersion medium 62 contained in the dispersion 6, but is usually 0. It is preferably ˜50 ° C., more preferably 15 to 40 ° C. When the temperature in the transport unit 3 is in such a range, the dispersion medium 62 can be efficiently removed from the droplets 6A while preventing unintentional modification of the resin constituting the resin fine particles 9 to be obtained. As a result, the toner productivity can be made particularly excellent. Further, since the formation of the resin fine particles 9 can proceed more smoothly, it is possible to contribute to the downsizing of the toner manufacturing apparatus 1.

In particular, it is preferable that the temperature in the transport unit 3 (processing temperature in the dispersion medium removing step) satisfies the following relationship with the glass transition point of the resin material constituting the dispersoid 61. That is, T ₁ [° C.] is the temperature in the transport unit 3 from which the droplets 6A are discharged (processing temperature in the dispersion medium removing step), and T g [° C.] is the glass transition point of the resin material constituting the dispersoid 61. In this case, the relationship 0 ≦ Tg−T ₁ ≦ 70 is preferably satisfied, the relationship 0 ≦ Tg−T ₁ ≦ 60 is more preferable, and the relationship 0 ≦ Tg−T ₁ ≦ 30 is satisfied. Is more preferable, and it is most preferable that the relationship of 5 ≦ Tg−T ₁ ≦ 26 is satisfied. By satisfying such a relationship, aggregation of the dispersoids 61 contained in the droplet 6A can be more reliably prevented. Further, it is possible to efficiently remove the dispersion medium 62 from the droplets 6A while preventing unintentional modification of the resin constituting the resin fine particles 9 to be obtained. As a result, the toner productivity is particularly excellent. can do. In addition, when the dispersoid 61 is comprised with multiple types of resin material (resin component), the value calculated | required as a weighted average value of the weight reference | standard of each of these components is employable as Tg.

  In the illustrated configuration, the pressure adjusting means 12 for adjusting the pressure in the housing 31 is connected to the housing 31 via a connecting pipe 121. By adjusting the pressure in the housing 31, the dispersion medium 62 can be efficiently removed from the droplets 6A, and the toner productivity is improved. In the configuration shown in the drawing, an enlarged diameter portion 122 having an enlarged inner diameter is formed in the vicinity of an end portion of the connection pipe 121 connected to the housing 31, and a filter 123 for preventing the suction of the resin fine particles 9 and the like. Is provided.

  Although the pressure in the housing 31 is not specifically limited, It is preferable that it is 150 kPa or less, It is more preferable that it is 100-120 kPa, It is further more preferable that it is 100-105 kPa. When the pressure in the housing 31 is a value within the above range, for example, the dispersion medium 62 is more smoothly removed from the droplet 6A while sufficiently preventing unintentional modification of the resin constituting the resin fine particles 9. be able to.

In the above description, the disperse medium 62 is removed from the droplet 6A of the dispersion 6 in the transport unit 3, so that one dispersoid 61 in the droplet 6A becomes the resin fine particles 9 almost as it is. However, the resin fine particles 9 are not limited to those obtained in this way. For example, when the dispersoid 61 contains a precursor of a resin material (for example, a monomer, a dimer, an oligomer, or the like corresponding to the resin material), a polymerization reaction is caused to proceed while removing the dispersion medium 61 in the transport unit 3. Thus, a method of obtaining the resin fine particles 9 may be used. In other words, the resin fine particles 9 may have substantially the same constituent material as the constituent material of the dispersoid 61 or may be different.
In addition, voltage application means 8 for applying a voltage to the inner wall surface of the housing 31 is connected to the housing 31. When the voltage application means 8 applies a voltage having the same polarity as the droplet 6A of the dispersion liquid 6 and the resin fine particles 9 to the inner wall surface of the housing 31, the following effects can be obtained.

  Usually, the toner particles and the resin fine particles 9 as the production intermediate thereof are charged positively or negatively. For this reason, if there is a charged substance charged with a polarity different from that of the resin fine particles 9 and the droplets 6A, a phenomenon occurs in which the resin fine particles 9 are electrostatically attracted and attached to the charged substance. On the other hand, if there is a charged substance charged with the same polarity as the resin fine particles 9 and the droplets 6A, the charged substance and the resin fine particles 9 repel each other, and the phenomenon that the resin fine particles 9 adhere to the surface of the charged substance is effective. Can be prevented. Therefore, by applying a voltage having the same polarity as the droplet 6A and the resin fine particle 9 to the inner surface side of the housing 31, it is possible to effectively prevent the droplet 6A and the resin fine particle 9 from adhering to the inner surface of the housing 31. Can do. Thereby, generation | occurrence | production of the toner powder of an irregular shape can be prevented more effectively, and the collection | recovery efficiency of the resin fine particles 9 is also improved.

The housing 31 has a reduced diameter portion 311 in which the inner diameter becomes smaller as the lower end portion in FIG. 1 faces downward. By forming such a reduced diameter portion 311, the resin fine particles 9 can be recovered efficiently. In the vicinity of the reduced diameter portion 311, since the dispersion 6 discharged from the nozzle 23, that is, the droplet 6 </ b> A is solidified into the resin fine particles 9, problems such as agglomeration almost occur even when each particle contacts. do not do.
The recovery unit 5 is connected to the lower end of the reduced diameter portion 311, and the dispersion medium 62 is removed from the resin fine particles 9 obtained by solidifying the granular dispersion 6, that is, the droplets 6 A. The obtained resin fine particles 9 are collected in the collection unit 5.

The treatment time of the dispersion medium removing step as described above (the time from when the dispersion liquid 6 is discharged in the form of droplets to when the resin fine particles 9 are collected by the collection unit 5) is preferably 5 to 120 seconds. 5 to 60 seconds is more preferable, and 5 to 20 seconds is still more preferable. When the treatment time of the dispersion medium removing step is within such a range, the productivity as the toner can be sufficiently enhanced while preventing unintentional modification of the resin constituting the resin fine particles 9 to be obtained. .
The resin fine particles 9 obtained as described above may be subjected to various treatments such as aeration, vacuum degassing (vacuum degassing), and heating. By applying aeration to the resin fine particles 9, the amount of the dispersion medium remaining in the resin fine particles 9 (for example, water content) can be reduced.

  The water content (water content) of the resin fine particles 9 is not particularly limited, but is preferably 15 wt% or less, more preferably 0.1 to 12 wt%, and further preferably 0.2 to 10 wt%. preferable. If the water content in the resin fine particles 9 is too large, it may be difficult to sufficiently reduce the water content in the final toner particles. When a relatively large amount of water is contained in the toner particles, there is a possibility that charging may become unstable. Further, in this step, if the water content (water content) of the resin fine particles 9 is reduced more than necessary, the constituent materials of the resin fine particles 9 are likely to be deteriorated and undesirably modified.

As described above, in the present invention, a dispersion liquid in which a dispersoid composed of a resin material is finely dispersed in a dispersion medium is discharged in a droplet shape, and the dispersion medium is removed from the droplet dispersion liquid. To obtain resin fine particles.
In particular, in the present invention, by forming an anti-aggregation layer on the surface of the dispersoid in the discharged dispersion, aggregation of the dispersoid in the liquid droplet is prevented, and the liquid dispersion By removing the dispersion medium from the liquid, the fine particles derived from the individual dispersoids contained in the liquid droplet dispersion can be made into resin fine particles. Therefore, only by making the dispersoid have a uniform shape and a small width of the particle size distribution, the obtained resin fine particles can also have a uniform shape and a small width of the particle size distribution.

  In addition, in general, when droplets are formed by the inkjet method, in addition to a main droplet having a required particle size, a sub-droplet having a particle size smaller than that of the main droplet may be subsequently generated. However, according to the present invention, aggregation of the dispersoids in the subdroplets can be prevented, and the fine particles derived from the individual dispersoids can be made into resin fine particles. Can be small.

Further, since the resin fine particles can be obtained as one fine particle derived from a dispersoid, the obtained resin fine particles have excellent mechanical strength without exposing the fine particles derived from the dispersoid to a temperature equal to or higher than the melting point. be able to. Moreover, since it is not necessary to expose the fine particles derived from the dispersoid to a temperature equal to or higher than the melting point, unintentional modification of the resin constituting the resin fine particles can be prevented.
In addition, since the resin fine particles can be obtained as fine particles derived from a single dispersoid, the dispersion medium can be quickly removed from the dispersion without exposing the discharged dispersion to high temperature, and the hollow particles and foreign particles can be removed. Generation of shaped particles can be prevented.
The resin fine particles 9 (toner) obtained as described above may be subjected to various treatments such as aeration, classification treatment, and external addition treatment as necessary.

For the classification treatment, for example, a sieve, an airflow classifier or the like can be used.
Examples of the external additive used for the external addition treatment include metal oxides such as silica, aluminum oxide, titanium oxide, strontium titanate, cerium oxide, magnesium oxide, chromium oxide, titania, zinc oxide, alumina, and magnetite. Fine particles composed of inorganic materials such as nitrides such as silicon nitride, carbides such as silicon carbide, calcium sulfate, calcium carbonate, aliphatic metal salts, acrylic resins, fluororesins, polystyrene resins, polyester resins, aliphatic metal salts Fine particles composed of organic materials such as these, and fine particles composed of a composite of these.

As the external additive, the surface of the fine particles as described above is subjected to a surface treatment with HMDS, a silane coupling agent, a titanate coupling agent, a fluorine-containing silane coupling agent, silicone oil or the like. It may be used.
The toner of the present invention produced as described above has a uniform shape and a sharp particle size distribution (small width). In particular, in the present invention, toner particles having a shape close to a true sphere can be obtained.

Specifically, the toner (toner particles) preferably has an average circularity R represented by the following formula (I) of 0.95 or more, more preferably 0.96 or more, and 0.97. More preferably, it is 0.98 or more. When the average circularity R is 0.95 or more, the toner transfer efficiency is further improved.
R = L ₀ / L ₁ (I)
(Where, L ₁ [μm] is the circumference of the projected image of the toner particles to be measured, and L ₀ [μm] is a perfect circle having an area equal to the area of the projected image of the toner particles to be measured (completely (Represents the perimeter of a geometric circle)
The toner preferably has a standard deviation of average circularity between particles of 0.02 or less, more preferably 0.015 or less, and further preferably 0.01 or less. When the standard deviation of the average circularity between the particles is 0.02 or less, variations such as charging characteristics and fixing characteristics are particularly reduced, and the reliability of the toner as a whole is further improved.

  The volume-based average particle diameter of the toner obtained as described above is preferably 0.5 to 9 μm, and more preferably 0.5 to 6 μm. When the average particle size of the toner is less than the lower limit, it becomes difficult to uniformly charge, and the adhesion force to the surface of the electrostatic latent image carrier (for example, a photoreceptor) increases. As a result, There may be an increase in the residual toner. On the other hand, when the average particle size of the toner exceeds the upper limit, the reproducibility of the contour portion of an image formed using the toner, particularly a character image or a light pattern, is deteriorated.

Further, the toner preferably has a standard deviation of the particle size between particles of 1.5 μm or less, more preferably 1.3 μm or less, and even more preferably 1.0 μm or less. When the standard deviation of the particle diameter between the particles is 1.5 μm or less, variations in charging characteristics, fixing characteristics and the like are particularly small, and the reliability of the toner as a whole is further improved.
The toner has a bulk density of preferably at 0.34 g / cm ³ or more, more preferably from 0.35~0.50g / cm ^3. This improves toner characteristics such as durability and transfer efficiency. Further, it is possible to increase the amount of toner filled in the cartridge of the same volume, and to reduce the size of the cartridge.

  The water content (water content) of the toner particles is not particularly limited, but is preferably 5 wt% or less, more preferably 0.01 to 4 wt%, and 0.02 to 1 wt%. Further preferred. When the water content in the toner particles is too high, there is a possibility that charging becomes unstable. If the water content in the toner particles is extremely reduced, deterioration of the toner constituent material, unintentional modification, and the like are likely to occur, so that it is not necessary to reduce the water content more than necessary.

As mentioned above, although this invention was demonstrated based on suitable embodiment, this invention is not limited to this.
For example, in the above-described embodiment, the dispersion preventing layer is formed on the surface of the dispersoid after discharging the dispersion. However, the present invention is not limited to this, and the aggregation preventing layer is formed before discharging the dispersion. It may be a thing. For example, an aggregation preventing layer may be formed on the surface of the dispersoid by previously applying a layer forming material (layer forming liquid) to the dispersion before discharging. Thereby, it can prevent more reliably that the dispersoids in the dispersion liquid before discharging aggregate. Further, the aggregation preventing layer can be reliably formed by the surface of the dispersoid in the discharged dispersion liquid, and the aggregation of the dispersoids can be more effectively prevented in the discharged dispersion liquid.

In the embodiment described above, the layer formation liquid is used to form the aggregation preventing layer. However, the present invention is not limited to this, and the layer formation liquid may not be used. For example, the aggregation preventing layer may be formed on the surface of the dispersoid by directly applying the layer forming material to the dispersion without using the layer forming liquid.
In the above-described embodiment, the entire surface of the dispersoid has been described as being covered with the layer forming material. However, the present invention is not limited to this, and there may be a portion not covered with the layer forming material.

Moreover, the anti-aggregation layer described above may remain on the surface of the resin fine particles finally obtained, or the anti-aggregation layer may be removed. When the aggregation preventing layer remains on the surface of the finally obtained resin fine particles, aggregation in the finally obtained resin fine particle powder can be prevented, and the storage stability of the resin fine particles is improved.
In addition, each unit constituting the toner manufacturing apparatus can be replaced with an arbitrary one that exhibits the same function, or another configuration can be added.

Further, instead of the head portion of the toner manufacturing apparatus in the above-described embodiment, a head portion as shown in FIG. 4 can be used.
Specifically, an acoustic lens (concave lens) 25 is installed in the head unit 2 shown in FIG. By installing such an acoustic lens 25, for example, the pressure pulse (vibration energy) generated by the piezoelectric element 22 can be converged by the pressure pulse converging unit 26 in the vicinity of the nozzle 23. As a result, vibration energy generated by the piezoelectric element 22 can be efficiently used as energy for discharging the dispersion liquid 6. Therefore, even if the dispersion 6 stored in the dispersion storage part 21 has a relatively high viscosity, it can be reliably discharged from the nozzle 23. In addition, even if the dispersion 6 stored in the dispersion storage unit 21 has a relatively large cohesive force (surface tension), it can be discharged as fine droplets. The particle size of the resin fine particles 9 and the finally obtained toner particles can be controlled to a relatively small value.
As described above, by using the head portion shown in FIG. 4, even if a material having higher viscosity or a material having a high cohesive force is used as the dispersion liquid 6, the resin fine particles 9 have a desired shape and size. Therefore, the range of material selection is particularly wide, and a toner having desired characteristics can be obtained more easily.

  Further, since the dispersion liquid 6 is discharged by the converged pressure pulse by using the head portion shown in FIG. 4, even if the area (opening area) of the nozzle 23 is relatively large, the dispersion liquid 6 to be discharged is discharged. The size can be made relatively small. That is, even when it is desired to relatively reduce the particle size of the finally obtained toner particles, the area of the nozzle 23 can be increased. Thereby, even if the dispersion liquid 6 has a relatively high viscosity, the occurrence of clogging in the nozzle 23 can be more effectively prevented.

In the head portion shown in FIG. 4, the configuration using the concave lens as the acoustic lens has been described, but the acoustic lens is not limited to this. For example, a Fresnel lens, an electronic scanning lens, or the like may be used as the acoustic lens.
Further, instead of the head portion of the toner manufacturing apparatus in the above-described embodiment, a head portion as shown in FIGS. 5 to 7 can be used.

Specifically, as shown in FIGS. 5 to 7, a diaphragm member 13 or the like having a converging shape can be disposed between the acoustic lens 25 and the nozzle 23 toward the nozzle 23. Thereby, convergence of the pressure pulse (vibration energy) generated by the piezoelectric element 22 can be assisted, and the pressure pulse generated by the piezoelectric element 22 can be used more efficiently.
In the embodiment described above, the configuration in which the granular dispersion liquid is discharged vertically downward has been described, but the discharge direction of the dispersion liquid may be any direction such as vertically upward or horizontal direction. Moreover, as shown in FIG. 8, the thing of the structure from which the discharge direction of the dispersion liquid 6 and the injection direction of the gas injected from the gas injection port 7 become substantially perpendicular | vertical may be sufficient. In this case, the traveling direction of the discharged granular dispersion 6 changes depending on the gas flow, and is transported substantially perpendicular to the discharge direction from the nozzle 23.

  In the above-described embodiment, the dispersion liquid is intermittently ejected from the head portion by the piezoelectric pulse. However, other methods can be used as a dispersion liquid ejection method (injection method). For example, as a method of discharging the dispersion, a method such as a so-called bubble jet (“bubble jet” is a registered trademark) method may be used. Examples of a method to which a so-called bubble jet (“bubble jet” is a registered trademark) method is applied include a method described in Japanese Patent Application No. 2002-169348. That is, as a method for discharging the dispersion liquid, a “method for intermittently discharging the dispersion liquid from the head portion by changing the volume of gas” can be applied.

In the above-described embodiment, the method for producing toner particles as resin fine particles has been described. However, the resin fine particles to which the present invention is applied are not limited to toner particles, and may be any type.
For example, when a powder coating is manufactured using the method for manufacturing resin fine particles of the present invention, a coating film coated using the obtained powder coating has extremely excellent smoothness, pinholes and There are very few coating film defects such as missing.

[1] Production of toner (Example 1)
First, an epoxy resin as a resin (Arakawa Chemical Co., modified epoxy resin, glass transition point Tg: 70 ° C., melting point Tm: 110 ° C.): 100 parts by weight, a phthalocyanine pigment as a colorant (Phthalocyanine Blue, manufactured by Dainichi Seika) : 5 parts by weight, and 300 parts by weight of tetrahydrofuran (manufactured by Wako Pure Chemical Industries) as a solvent were prepared.

These components were mixed and dispersed in a ball mill for 10 hours to prepare a resin solution (resin solution).
On the other hand, an aqueous solution (aqueous solution) prepared by dissolving 10 parts by weight of sodium polyacrylate as a dispersant (manufactured by Wako Pure Chemical Industries, average polymerization degree n = 2700-7500) in 590 parts by weight of ion-exchanged water was prepared.

  Next, 600 parts by weight of this aqueous solution is placed in a 3 liter round bottom stainless steel container, and a binder resin solution: 409 wt. The portion was gradually added dropwise over 10 minutes. At this time, the liquid temperature was kept at 70 ° C. The emulsion was further stirred for 10 minutes while maintaining the liquid temperature at 70 ° C. after the completion of the dropwise addition of the binder resin solution.

Next, under conditions of temperature: 45 ° C. and atmospheric pressure: 10 to 20 kPa, the tetrahydrofuran in the emulsified liquid (dispersoid) is removed, then cooled to room temperature, and further ion-exchanged water is added. A resin dispersion in which fine particles containing a resin were dispersed as a dispersoid was obtained.
Thereafter, the obtained resin dispersion was subjected to deaeration treatment. The deaeration treatment was performed by placing the stirred resin (dispersion liquid in an atmosphere of 14 kPa for 10 minutes. The ambient temperature during the deaeration treatment was 25 ° C. In this way, it was obtained. The solid content (dispersoid) concentration in the resin dispersion was 10 wt%, and the viscosity of the resin dispersion at 25 ° C. was 150 mPa · s. The average particle diameter Dm was 5 μm, and the average particle diameter of the dispersoid was measured using a laser diffraction / scattering particle size distribution measuring apparatus (LA-920, manufactured by Horiba, Ltd.).

  The degassed resin dispersion was put into a dispersion supply part of a toner production apparatus as shown in FIGS. While stirring the dispersion liquid in the dispersion liquid supply part with the stirring means, the liquid was supplied to the dispersion liquid storage part of the head part by the metering pump, and was discharged from the nozzle to the transport part. The nozzle had a circular shape with a diameter of 26 μm. Moreover, as the head portion, a head portion that has been subjected to a hydrophobic treatment with a fluororesin (polytetrafluoroethylene) coat in the vicinity of the nozzle was used.

  The dispersion liquid is discharged at a temperature of 25 ° C. in the head part, the frequency of the piezoelectric body is 10 kHz, the initial speed of the dispersion liquid discharged from the nozzle is 4 m / second, and one drop of the dispersion liquid discharged from the head part. The discharge amount was adjusted to 1.5 pl (average particle diameter Dd: 8 μm). Further, the dispersion liquid was discharged so that the discharge timing of the dispersion liquid was shifted in at least adjacent head parts among the plurality of head parts.

  At the time of discharging the dispersion, air having a temperature of 40 ° C., humidity of 27% RH, and a flow velocity of 4 m / second is jetted vertically downward from the gas injection port, and the pressure in the housing (atmospheric pressure) is 100. It adjusted so that it might become -105kPa. Further, a cooling region having an ambient temperature of 10 to 15 ° C. and a length of 30 cm was provided immediately below the head portion, and the temperature (atmospheric temperature) of other regions was adjusted to be 40 to 60 ° C. The length of the conveyance part (length in the conveyance direction) was 2 m.

  As shown in FIG. 1, a layer forming liquid was sprayed from the layer forming liquid supply means to the discharged dispersion liquid in the cooling region. As the layer forming liquid, a liquid in which polytetrafluoroethylene (PTFE) is finely dispersed in an aqueous dispersion medium (ion exchange water) is used. The concentration of PTFE in the layer forming liquid was 40 wt%, and the average particle size of PTFE was 0.1 μm. The layer forming liquid was jetted so that the PTFE content in the finally obtained toner powder was 0.25 wt%.

  In the transport section, the dispersion medium was removed from the discharged dispersion liquid to form resin fine particles of dispersoid (fine particles), and the formed resin fine particles were collected in the collection section (dispersion medium removal step). Further, the processing time (time required for passing through the inside of the transport unit) of the dispersion medium removing step for each particle (droplet and resin fine particles formed from the droplet) was 12 seconds. Moreover, the water content of the obtained resin fine particles was 0.7 to 3 wt%. The water content was measured by the Karl Fischer method.

Thereafter, the water content of the resin fine particles was reduced to about 0.5 wt% by performing aeration for 1 hour while the obtained resin fine particles were heated to 50 ° C.
The obtained toner particles had a water content of 0.3 to 0.5 wt%, an average circularity R of 0.989, and a circularity standard deviation of 0.010. The volume-based average particle diameter Dt was 5.7 μm. The volume standard particle diameter standard deviation was 0.9 μm. The circularity was measured in a water dispersion system using a flow particle image analyzer (manufactured by Toa Medical Electronics Co., Ltd., FPIA-2000).

(Example 2)
A toner was produced in the same manner as in Example 1 except that a styrene-acrylic acid ester copolymer (glass transition point Tg: 52 ° C., melting point Tm: 105 ° C.) was used as the resin.
(Example 3)
A toner was produced in the same manner as in Example 1 except that the liquid for layer formation was a polytetrafluoroethylene-perfluoroalkoxy-ethylene copolymer (PFA) finely dispersed in an aqueous dispersion medium. The concentration of PFA in the layer forming liquid was 40 wt%, and the average particle size of PFA was 0.05 μm.

Example 4
The same procedure as in Example 1 was performed except that the layer forming liquid was applied to the degassed resin dispersion so that the concentration of PTFE was 0.025 wt% without spraying the layer forming liquid. A toner was produced.
(Comparative Example 1)
A toner was produced in the same manner as in Example 1 except that the layer forming liquid was not sprayed.

(Comparative Example 2)
Aggregates in which the average particle size of the dispersoid in the resin dispersion is 0.2 μm and a plurality of fine particles derived from the dispersoid are aggregated by the toner manufacturing apparatus shown in FIG. 1 without spraying the layer forming liquid. A toner was manufactured in the same manner as in Example 1 except that resin fine particles were obtained by heat treatment.

At this time, the heat treatment was performed using a surfing system (Nihon Pneumatic Kogyo Co., Ltd., SFS-3 type). The heat treatment is performed under the conditions of treatment temperature (hot air temperature): 70 ° C., hot air flow rate: 1 m ³ / min, dispersed air flow rate: 0.1 m ³ / min, raw material charging speed: 0.5 kg / hour, suction air flow rate: 10 m ³ / min. I went there. Moreover, the processing time about each aggregate (each particle) was 3 second. Thereby, the fine particles constituting the aggregate were melt-bonded to obtain resin fine particles.
Table 1 shows the toner production conditions for Examples 1 to 4 and Comparative Examples 1 and 2 (hereinafter referred to as Examples and Comparative Examples).

[2] Evaluation Each toner obtained as described above was evaluated for the abundance ratio, durability, transfer efficiency, and storage stability of the hollow particles.
[2.1] Abundance ratio of hollow particles For each toner obtained in each of the examples and comparative examples, the internal structure of each toner particle was observed using a transmission electron microscope (TEM) to obtain hollow particles. The abundance ratio was evaluated according to the following four-stage criteria.

A: The presence of hollow particles is not recognized at all.
A: The presence of hollow particles is slightly observed, but the abundance ratio is less than 1%.
Δ: The abundance ratio of hollow particles is 1% or more and less than 3%.
X: The abundance ratio of the hollow particles is 3% or more.
Further, as an indicator of the presence of hollow particles, the bulk density was measured for each toner obtained in each of the above Examples and each of the above Comparative Examples using a bulk specific gravity measuring instrument (JIS-K5101, manufactured by Tsutsui Rikagaku Co., Ltd.). .

[2.2] Durability The toner obtained in each Example and each Comparative Example was set in a developing device of a color laser printer (manufactured by Seiko Epson Corporation: LP-2000C). Thereafter, the developing machine was continuously rotated so as not to print. After 12 hours, the developing machine was taken out, the uniformity of the toner thin layer on the developing roller was visually confirmed, and evaluated according to the following four criteria.
A: No disturbance is observed in the thin layer.
○: Disturbance is hardly observed in the thin layer.
Δ: Some disturbance is observed in the thin layer.
X: Streaky disturbance is clearly observed in the thin layer.

[2.3] Transfer Efficiency The transfer efficiency of each toner obtained as described above was evaluated.
Transfer efficiency was evaluated as follows using a color laser printer (manufactured by Seiko Epson Corporation, LP-2000C).
The toner on the photoconductor immediately after the development process to the photoconductor (before transfer) and the toner on the photoconductor after transfer (after printing) were collected using different tapes, and their weights were measured. When the toner weight on the photoconductor before transfer is W _b [g] and the toner weight on the photoconductor after transfer is W _a [g], it is obtained as (W _b −W _a ) × 100 / W _b. The value was defined as transfer efficiency.

[2.4] Storage stability 10 g of the toner of each example and each comparative example is put in a sample bottle and left in a thermostat at 50 ° C. for 48 hours, and then visually checked for the presence of lumps (aggregation). The evaluation was made according to the following three-stage criteria.
A: The presence of lumps (aggregation) was not recognized at all.
(Triangle | delta): The small lump (aggregation) was recognized slightly.
X: A lump (aggregation) was clearly recognized.
These results are shown in Table 2.

As is apparent from Tables 1 and 2, the toners of the present invention (Examples 1 to 4) all had a large degree of circularity and a small width of the particle size distribution. Further, the variation in shape (standard deviation of circularity) was small, and irregularly shaped toner particles such as hollow particles were not substantially contained. This is because the aggregation of the dispersoid is prevented by the formation of the aggregation preventing layer on the surface of the dispersoid, and the obtained toner is derived from one dispersoid. Is considered to be reflected in the circularity and particle size distribution of the toner as it is.
On the other hand, the toner of Comparative Example 1 has a small degree of circularity, and many toner particles having relatively large convex portions were observed. This is considered to be due to the following reasons.

  In Comparative Examples 1 and 2, when the dispersion medium is removed from the droplets of the dispersion liquid, dispersoid aggregation occurs, and the aggregation does not proceed uniformly. It has a large number of relatively large irregularities, and the variation in shape and size between the particles is large. Further, since the removal of the dispersion medium proceeds rapidly, the abundance ratio of irregularly shaped toner particles such as hollow particles becomes high.

  Further, as apparent from Table 2, the toners of the examples of the present invention were excellent in transfer efficiency. On the other hand, the toner of each comparative example was inferior in transfer efficiency. This is because the toner of the comparative example has a large variation in shape and size among the particles, and many irregularly shaped toner particles such as hollow particles are included, so that the variation in characteristics between the particles is large. The toner of the present invention substantially does not contain irregularly shaped toner particles such as hollow particles (or the existence ratio is extremely low even if it is contained), and the shape, size between the toner particles as described above, This is considered to be due to the fact that the variation in characteristics is sufficiently small. Further, the toner of the present invention had excellent durability, while the toner of the comparative example was inferior in durability.

Such transfer characteristics and durability results also contribute to the fact that the toner of the present invention does not substantially contain irregularly shaped toner particles such as hollow particles, or the existence ratio is extremely low even if included. It is thought that.
Further, the toners of the examples were excellent in storage stability. This is presumably because an aggregation preventing layer is formed on the surface of the toner.

[3] Production of powder paint (Example 5)
Resin fine particles were produced in the same manner as in Example 1 except that the disk-type spray dryer (Sakamoto Giken Co., Ltd., DCTRS-3N type) was used instead of the head of the resin fine particle production apparatus shown in FIG. A body paint was used.
At this time, the dispersion was sprayed by injecting the dispersion with compressed air having a temperature of 40 ° C. and a pressure of 0.65 MPa at an initial speed of 4 m / sec. The dispersion was sprayed at 20 mL per minute, and the average spray amount for one drop of the dispersion sprayed from the nozzle was 1.5 pl (average particle diameter Dm: 8 μm).

(Example 6)
A powder coating material was produced in the same manner as in Example 6 except that a styrene-acrylic acid ester copolymer (glass transition point Tg: 52 ° C., melting point Tm: 105 ° C.) was used as the resin.
(Comparative Example 3)
In the same manner as in Example 6, except that the layer forming liquid was not sprayed, the compressed air used for spraying the dispersion liquid was set to a temperature of 150 ° C., the pressure was set to 0.55 MPa, and the temperature in the conveying unit was set to 150 ° C. A body paint was produced.

[4] Evaluation For each powder paint obtained as described above, the abundance ratio of the hollow particles was evaluated in the same manner as in [2.1] described above.
As is apparent from Table 2, the powder coating material of the present invention (Examples 5 and 6) did not substantially contain irregular-shaped coating particles such as hollow particles.

On the other hand, in the powder coating material of Comparative Example 3, many coating particles having relatively large convex portions were recognized.
In addition, the powder coatings of Examples 5 and 6 have a higher bulk density than the powder coating of Comparative Example 3, and thus it is understood that there are fewer hollow particles and irregular shaped particles than the powder coating of Comparative Example 3. .
About each such powder coating material, it applied to a base material, and when the external appearance of the obtained coating film was visually observed, the coating film using the powder coating material of Examples 5 and 6 was extremely excellent in smoothness. In addition, no coating film defects were observed. On the other hand, the coating film using the powder coating material of Comparative Example 3 was inferior in smoothness compared to Examples 5 and 6, and coating film defects such as pinholes were confirmed.

In addition, the said base material used what applied the melamine hardening polyester resin system intermediate coating to the mild steel plate (Nippon Parkerizing Co., Ltd. bonderite # 3030) which electrodeposited the epoxy resin system cationic electrodeposition coating.
In addition, each powder coating is applied in two portions so that the dried coating film is 20 μm in an environment of a temperature of 25 ° C. and a relative humidity of 65 to 70%. Baking was performed for a minute to obtain a coating film. The air pressure of the spray gun at the time of painting was 5 kg / cm, the flow rate of the paint was 400 m / min, and the distance between the substrate and the spray gun was 40 cm.

1 is a longitudinal sectional view schematically showing a first embodiment of a toner manufacturing apparatus used for manufacturing a toner of the present invention. FIG. 2 is an enlarged cross-sectional view of the vicinity of a head portion of the toner manufacturing apparatus shown in FIG. 1. It is sectional drawing which shows typically the dispersoid in which the aggregation prevention layer was formed. It is a figure which shows typically the structure of the head part vicinity of the toner manufacturing apparatus of other embodiment. It is a figure which shows typically the structure of the head part vicinity of the toner manufacturing apparatus of other embodiment. It is a figure which shows typically the structure of the head part vicinity of the toner manufacturing apparatus of other embodiment. It is a figure which shows typically the structure of the head part vicinity of the toner manufacturing apparatus of other embodiment. It is a figure which shows typically the structure of the head part vicinity of the toner manufacturing apparatus of other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Toner manufacturing apparatus 2 ... Head part 21 ... Dispersion liquid storage part 22 ... Piezoelectric element 221 ... Lower electrode 222 ... Piezoelectric body 223 ... Upper electrode 23 ... Nozzle 24 ... Diaphragm 25 ... Acoustic lens 26 …… Pressure pulse converging part 3 …… Conveying part 31 …… Housing 311 …… Reducing diameter part 4 …… Dispersed liquid supply part 41 …… Agitating means 5 …… Recovery part 6 …… Dispersed liquid 6A …… Liquid Drop 61 ... Dispersoid 62 ... Dispersion medium 7 ... Gas injection port 8 ... Voltage application means 9 ... Resin fine particles 10 ... Gas flow supply means 101 ... Duct 11 ... Heat exchanger 12 ... Pressure adjustment Means 121... Connection pipe 122... Expanded diameter part 123... Filter 13... Throttling member 14.

Claims (15)

A method for producing resin fine particles using a dispersion in which a dispersoid mainly composed of a resin material is finely dispersed in a dispersion medium,
Discharging the dispersion into droplets;
Removing the dispersion medium from the droplet-like dispersion liquid,
A method for producing resin fine particles, comprising forming an anti-aggregation layer on a surface of the dispersoid to prevent or suppress aggregation of the dispersoids.   The method for producing resin fine particles according to claim 1, wherein the formation of the aggregation preventing layer is performed by applying a material for forming the aggregation preventing layer to the dispersion liquid discharged in the form of droplets.   The method for producing resin fine particles according to claim 2, wherein the application of the material is performed by spraying a liquid for layer formation in which the material is finely dispersed to the dispersion liquid ejected in the form of droplets. When the average particle size of the dispersoid is Dm [μm] and the average particle size of the material in the layer forming liquid is Dc [μm], 1 × 10 ⁻³ ≦ Dc / Dm ≦ 1 × 10 ^−1. The method for producing resin fine particles according to claim 3, wherein the relationship is satisfied.   The method for producing resin fine particles according to claim 3 or 4, wherein an average particle diameter of the material in the layer forming liquid is 0.02 to 1.0 µm.   The method for producing resin fine particles according to claim 1, wherein the aggregation preventing layer is mainly composed of a fluororesin.   The method for producing resin fine particles according to claim 6, wherein the fluororesin is polytetrafluoroethylene.   When the average particle size of the discharged liquid droplets is Dd [μm] and the average particle size of the dispersoid is Dm [μm], a relationship of 0.5 <Dm / Dd <1.0 is established. The method for producing fine resin particles according to claim 1, wherein the method is satisfactory.   The method for producing resin fine particles according to any one of claims 1 to 8, wherein in the step of removing the dispersion medium, the dispersion medium is removed by heating at a temperature lower than the boiling point of the dispersion medium.   The method for producing resin fine particles according to claim 1, wherein the resin fine particles are toner particles.   The method for producing resin fine particles according to claim 1, wherein the resin fine particles are powder paint.   A resin fine particle produced by the method for producing a resin fine particle according to claim 1. The resin fine particles according to claim 12, wherein an average circularity R represented by the following formula (I) is 0.95 or more.
R = L ₀ / L ₁ (I)
(Where, L ₁ [μm] is the circumference of the projected image of the resin fine particle to be measured, and L ₀ [μm] is the circumference of a perfect circle having an area equal to the area of the projected image of the resin fine particle to be measured) Represents length)   The resin fine particles according to claim 12 or 13, wherein the standard deviation of the average circularity between the particles is 0.015 or less. The resin fine particle according to any one of claims 12 to 14, which has a bulk density of 0.34 g / cm ³ or more.

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