JP2005173263A - Manufacturing method of toner, toner, and apparatus for manufacturing toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner of uniform shape being narrow in grain size distribution by an environmentally friendly method. <P>SOLUTION: The toner is manufactured by using a dispersion 6 which is prepared by finely dispersing dispersoid mainly consisting of resin materials into a dispersion medium and is subjected to degassing treatment. The dispersion 6 charged into a dispersion feeding section 4 is fed into a head section 2. The head section 2 has a dispersion storage section 4 for storing the dispersion 6 and a discharge section for discharging the dispersion 6. The dispersion 6 in the dispersion storage section 4 is discharged from the discharge section to a solidifying section 3 by the piezoelectric pulse of a piezoelectric element. The discharged dispersion 6 has a granular form. While the dispersion 6 is conveyed in the solidifying section 3, the dispersion is removed of a dispersion medium and is thereby solidified to a toner particle 9. A voltage applying means 8 is connected to a cylindrical housing 31 constituting the solidifying section 3 and the voltage of the same polarity as that of the granular dispersion 6 is applied to the housing 31. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a toner manufacturing method, a toner, and a toner manufacturing apparatus.

A number of methods are known as electrophotographic methods. In general, a process (exposure process) of forming an electrical latent image on a photoconductor by various means using a photoconductive substance, A developing step of developing the latent image with toner, a transferring step of transferring the toner image onto a transfer material such as paper, and a step of fixing the toner image by heating, pressing, etc. using a fixing roller. doing.
As a method for producing a toner used in such an electrophotographic method, a pulverization method, a polymerization method, and a spray drying method are used.

  In the pulverization method, a raw material containing a resin as a main component (hereinafter also simply referred to as “resin”) and a colorant is kneaded at a temperature equal to or higher than the softening point of the resin to obtain a kneaded product, and then the kneading. This is a method of cooling and pulverizing an object (for example, see Non-Patent Document 1). Such a pulverization method is excellent in that the range of selection of raw materials is wide and toner can be produced relatively easily. However, the toner obtained by the pulverization method has the disadvantages that the variation in shape among the particles is large and the particle size distribution tends to be wide. As a result, variations in charging characteristics, fixing characteristics, and the like among the toner particles increase, and the reliability of the entire toner decreases.

  In the polymerization method, toner particles are produced by performing a polymerization reaction in a liquid phase or the like using a monomer that is a constituent component of a resin to produce a target resin (for example, Patent Documents). 1). Such a polymerization method is excellent in that the shape of the obtained toner particles can be made to have a relatively high sphericity (geometrically close to a perfect sphere). However, in the polymerization method, there may be a case where the particle size variation cannot be sufficiently reduced between the particles. Further, in the polymerization method, the selection range of the resin material is narrow, and it may be difficult to obtain a toner having the desired characteristics.

  The spray drying method is a method of obtaining a fine powder as a toner by spraying a raw material for toner production dissolved in a solvent using a high-pressure gas. The spray drying method has an advantage that the pulverization step as described above is unnecessary. However, in such a spray drying method, since the raw material is sprayed using a high-pressure gas, it is difficult to accurately control the raw material spraying conditions. For this reason, for example, it is difficult to efficiently produce toner particles having a desired shape and size. Further, in the spray drying method, since the variation in the size of the particles formed by spraying is large, the variation in the moving speed of each particle is also large. For this reason, before the sprayed raw material solidifies, the sprayed particles collide and agglomerate to form an irregularly shaped powder, and the resulting variation in the shape and size of the toner particles is even greater. Sometimes. As described above, since the toner obtained by the spray drying method has a large variation in shape and size between the particles, the variation in charging characteristics and fixing characteristics among the toner particles is large, and the toner as a whole is large. Reliability decreases.

Supervised by the Society of Electrophotography, “Basics and Applications of Electrophotography” published by Corona, 1988, p482-486 JP-A-6-332257 (page 2, lines 28-35)

  An object of the present invention is to provide a toner having a uniform shape and a narrow particle size distribution, and to provide a toner production method and a toner production apparatus capable of producing such a toner. is there.

Such an object is achieved by the present invention described below.
The method for producing a toner of the present invention is a method for producing a toner using a dispersion in which a dispersoid containing a raw material for toner production is finely dispersed in a dispersion medium,
A degassing step of degassing the dispersion;
And a step of making the dispersion liquid subjected to the deaeration treatment into fine particles, spraying from the head portion, solidifying the particles while transporting the inside of the solidification portion, and granulating.
Thereby, a toner having a uniform shape and a small width of the particle size distribution can be provided.

In the toner manufacturing method of the present invention, it is preferable that the dispersion is intermittently ejected by piezoelectric pulses.
As a result, the dispersion liquid sprayed (discharged) after being atomized can be discharged intermittently drop by drop, and the stability of the shape of the discharged dispersion liquid is improved. As a result, it is possible to obtain a toner having a small variation in shape and size between particles, and to produce toner particles having a high sphericity (geometrically close to a perfect sphere). Can be done relatively easily.

In the toner manufacturing method of the present invention, the head section stores a dispersion liquid storage section that stores the dispersion liquid, a piezoelectric body that applies a piezoelectric pulse to the dispersion liquid stored in the dispersion liquid storage section, and the piezoelectric pulse. It is preferable to have a discharge unit that discharges the dispersion liquid.
This further improves the stability of the shape of the dispersion liquid that is atomized and ejected (discharged). As a result, it is possible to obtain a toner having a particularly small variation in shape and size between the particles, and to produce toner particles having a high sphericity (geometrically nearly spherical shape). It is relatively easy to do.

In the method for producing a toner of the present invention, it is preferable that the discharge portion has a substantially circular shape and has a diameter of 5 to 500 μm.
Accordingly, it is possible to stably discharge a fine particle (droplet-shaped) dispersion liquid with small variations in shape, size, and the like while preventing clogging and the like in the discharge unit.
In the toner manufacturing method of the present invention, the frequency of the piezoelectric pulse is preferably 1 kHz to 500 MHz.
As a result, it is possible to improve the toner productivity while sufficiently reducing variations in the shape and size of the liquid droplets to be discharged.

In the method for producing a toner of the present invention, it is preferable that the dispersoid in the dispersion liquid discharged from the head portion is aggregated when passing through the solidification portion.
As a result, a toner having a more uniform shape and a narrow width of particle size distribution can be provided.
In the toner production method of the present invention, the degassing step is preferably performed by placing the dispersion in an atmosphere of 80 kPa or less.
Thereby, the dissolved gas can be efficiently removed while sufficiently maintaining the shape of the dispersoid in the dispersion.

In the method for producing a toner of the present invention, it is preferable that the dispersion medium is mainly composed of water and / or a liquid having excellent compatibility with water.
Thereby, for example, the dispersibility of the dispersoid in the dispersion medium can be enhanced, and the dispersoid in the dispersion can have a relatively small particle size and a particularly small variation in size. . As a result, it is possible to obtain toner particles having a particularly small variation in size and shape between particles and a large circularity.
In the method for producing a toner of the present invention, the dispersion is preferably a suspension.
Thus, it is possible to more effectively prevent unnecessary components such as a solvent from remaining in the finally obtained toner. As a result, the reliability of the toner is particularly excellent.

In the toner production method of the present invention, the dispersion is preferably prepared by introducing a material containing a resin or a precursor thereof into a liquid containing at least water.
Thereby, a dispersion liquid can be prepared comparatively easily. Further, in the solidified portion, the organic solvent can be substantially prevented from volatilizing, and the toner can be manufactured by a method that hardly causes adverse effects on the environment.
In the method for producing a toner of the present invention, the dispersion liquid undergoes a mixing step of mixing a resin liquid containing at least a resin or a precursor thereof and a solvent that dissolves at least a part thereof and an aqueous liquid containing at least water. It is preferable that it is prepared.
Thereby, the particle size of the dispersoid in the dispersion liquid can be adjusted to an appropriate size relatively easily, and the dispersion of the size and shape of the dispersoid can be particularly small.

In the toner production method of the present invention, the mixing of the resin liquid and the aqueous liquid is preferably performed by dropping droplets of the resin liquid into the aqueous liquid.
Thereby, the particle size of the dispersoid in the dispersion can be adjusted to an appropriate size, and the dispersion of the size and shape of the dispersoid can be further reduced.

In the method for producing a toner of the present invention, it is preferable that the dispersion is prepared by removing at least a part of the solvent after the mixing step.
Thereby, a dispersion liquid (suspension) including a solid dispersoid and having a particularly small variation in size and shape of the dispersoid can be obtained.
In the method for producing a toner of the present invention, the solvent is preferably removed by heating.
As a result, the dispersoid can be solidified (a suspension is obtained) more efficiently while the dispersion of the size and shape of the dispersoid is sufficiently small.

In the method for producing a toner of the present invention, the average particle size of the dispersoid in the dispersion is preferably 0.05 to 1.0 μm.
As a result, the toner particles can be obtained with a sufficiently high degree of circularity and particularly excellent uniformity in characteristics and shape among the particles. Thereby, the discharge conditions of the dispersion can be further stabilized.

In the toner manufacturing method of the present invention, when the average particle size of the dispersoid in the dispersion is Dm [μm] and the average particle size of the toner particles to be manufactured is Dt [μm], 0.005 ≦ Dm It is preferable to satisfy the relationship of /Dt≦0.5.
As a result, a toner having particularly small variations in shape and size among the particles can be obtained.

In the method for producing a toner of the present invention, the content of the dispersoid in the dispersion is preferably 1 to 99 wt%.
As a result, toner particles having an appropriate degree of circularity and a particularly small variation in particle size and shape can be obtained efficiently.
In the toner manufacturing method of the present invention, it is preferable that a discharge amount of one drop of the dispersion discharged from the head portion is 0.05 to 500 pl.
Thereby, toner particles having an appropriate particle diameter can be obtained more reliably.

In the method for producing a toner of the present invention, when the average particle diameter of the dispersion discharged from the head portion is Dd [μm] and the average particle diameter of the dispersoid in the dispersion is Dm [μm] It is preferable that the relationship of Dm / Dd <0.5 is satisfied.
This makes it possible to reduce the variation in the particle diameter of the toner particles while sufficiently exhibiting the characteristics of the dispersion liquid (good liquid drainage, etc.) during toner production.

In the method for producing a toner of the present invention, when the average particle diameter of the dispersion discharged from the head portion is Dd [μm] and the average particle diameter of the produced toner particles is Dt [μm], 0.05 is obtained. It is preferable that the relationship of ≦ Dt / Dd ≦ 1.0 is satisfied.
As a result, toner particles that are sufficiently fine, have a high degree of circularity, and a sharp particle size distribution can be obtained relatively easily.

In the toner manufacturing method according to the aspect of the invention, it is preferable that the dispersion discharged from the head unit is discharged into a gas flow flowing in almost one direction.
Thus, the granular dispersion can be efficiently solidified in the solidification part, and the dispersion (toner particles) can be more efficiently conveyed.
In the toner manufacturing method of the present invention, it is preferable that the dispersion liquid is discharged from a plurality of the head portions.
Thereby, toner particles can be produced more efficiently.

In the toner manufacturing method of the present invention, it is preferable that the dispersion liquid is ejected while gas is ejected from between the head parts adjacent to each other.
Thereby, a dispersion liquid can be conveyed and solidified, maintaining the space | interval of the granular dispersion liquid discharged from the head part. As a result, collision and aggregation between the discharged granular dispersions can be more effectively prevented.

In the toner manufacturing method of the present invention, it is preferable that the humidity of the gas ejected from between the head portions adjacent to each other is 50% RH or less.
This makes it possible to efficiently remove the dispersion medium contained in the dispersion in the solidifying unit, and the toner productivity is further improved.
In the toner manufacturing method of the present invention, it is preferable to shift the discharge timing of the dispersion liquid from at least two adjacent head portions.
Thereby, before the granular dispersion liquid discharged from the adjacent head part solidifies, it can prevent more effectively that a granular dispersion liquid collides and aggregates.

In the toner manufacturing method according to the aspect of the invention, it is preferable that the dispersion is discharged in a state where a voltage having the same polarity as that of the dispersion is applied to the solidification portion.
Thereby, it is possible to effectively prevent the dispersion liquid and toner particles from adhering to the inner surface (inner wall) of the solidified portion. As a result, the generation of irregularly shaped toner particles can be more effectively prevented, and the toner particle recovery efficiency can be improved.

In the toner manufacturing method of the present invention, it is preferable that an initial speed of the dispersion liquid discharged from the head portion is 0.1 to 10 m / second.
As a result, the toner particles obtained can be made to have a higher degree of circularity while sufficiently increasing the productivity of the toner.
In the toner manufacturing method of the present invention, the viscosity of the dispersion in the head is preferably 0.5 to 200 [mPa · s].
As a result, even when the discharge interval of the dispersion liquid is relatively short, the liquid droplet dispersion liquid with small variations in size and shape can be discharged more reliably. As a result, it is possible to produce a toner having a small variation in size and shape between particles with excellent productivity.

In the toner production method of the present invention, it is preferable that the dispersion medium is removed in the solidification part.
As a result, a toner having a more uniform shape and a narrow width of particle size distribution can be provided.
In the method for producing a toner of the present invention, the pressure in the solidified part is preferably 150 kPa or less.
This makes it possible to more smoothly remove the dispersion medium from the liquid droplet dispersion while sufficiently preventing the generation of irregularly shaped toner particles.

In the toner manufacturing method of the present invention, it is preferable that the dispersion is discharged from the head portion in a heated state.
Thereby, in the solidification part, aggregation (fusion) of the dispersoids contained in the granular dispersion can proceed more smoothly, and the circularity of the obtained toner particles can be made particularly high.
In the toner manufacturing method of the present invention, it is preferable that the dispersion discharged from the head unit is heated by the solidification unit.
Thereby, in the solidification part, aggregation (fusion) of the dispersoids contained in the granular dispersion can proceed more smoothly, and the circularity of the obtained toner particles can be made particularly high.

The toner of the present invention is produced by the method of the present invention.
Thereby, a toner having a uniform shape and a small width of the particle size distribution can be provided.
In the toner of the present invention, the average particle diameter is preferably 2 to 20 μm.
As a result, the variation in characteristics such as charging characteristics and fixing characteristics among the toner particles is particularly small, and the resolution of the image formed by the toner is sufficiently high while the reliability of the entire toner is particularly high. Can be.

In the toner of the present invention, it is preferable that the standard deviation of the particle diameter between each particle is 1.5 μm or less.
As a result, variations in characteristics such as charging characteristics and fixing characteristics among the toner particles are particularly reduced, and the reliability of the toner as a whole is further improved.
In the toner 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 toner particles 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 toner particles to be measured) Represents length)
Thereby, the transfer efficiency and mechanical strength of the toner particles can be made particularly excellent while the particle diameter of the toner particles is sufficiently small. Also, the fluidity of the toner is improved.

In the toner of the present invention, the standard deviation of the average circularity between each particle is preferably 0.02 or less.
As a result, variations such as charging characteristics and fixing characteristics are particularly reduced, and the reliability of the toner as a whole is further improved.
In the toner of the present invention, the dispersoid is preferably composed of aggregates.
Thereby, the circularity of the toner particles can be made sufficiently large.
The toner production apparatus of the present invention is characterized by carrying out the method of the present invention.
Thereby, a toner having a uniform shape and a small width of the particle size distribution can be manufactured.

Hereinafter, preferred embodiments of a toner production method, a toner, and a toner production apparatus of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a longitudinal sectional view schematically showing a first embodiment of the toner manufacturing apparatus of the present invention, and FIG. 2 is an enlarged sectional view of the vicinity of the head portion of the toner manufacturing apparatus shown in FIG.
[Dispersion]
First, the dispersion 6 used in the present invention will be described. The toner of the present invention is produced using the dispersion liquid 6. Examples of the dispersion include suspensions (suspensions) and emulsions (emulsions, emulsions, and emulsions). 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 and ethyl benzoate, amine solvents such as trimethylamine, hexylamine, triethylamine and aniline, nitrile solvents such as acrylonitrile and 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 particles 9 are small in size and shape variation between the particles, and have high 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 solidification section of the toner manufacturing apparatus described later. In addition, the dispersion medium 62 can be removed at a relatively low temperature in a solidification section of a toner manufacturing apparatus, which will be described later, and deterioration of characteristics of the obtained toner particles 9 can be more effectively prevented. 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 solidification portion of the toner manufacturing apparatus 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 9 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 monomer, dimer, oligomer, or the like as a precursor thereof).
Hereinafter, the constituent material of the dispersoid 61 will be described.
1. Resin (binder resin)
Examples of the resin (binder resin) include polystyrene, poly-α-methylstyrene, chloropolystyrene, styrene-chlorostyrene copolymer, styrene-propylene copolymer, styrene-butadiene copolymer, and styrene-vinyl chloride copolymer. Polymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-acrylic acid ester-methacrylic acid ester copolymer, styrene -Monopolymer or copolymer containing styrene or styrene-substituted styrene resin such as methyl α-chloroacrylate copolymer, styrene-acrylonitrile-acrylic acid ester copolymer, styrene-vinyl methyl ether copolymer , Polyester resin, epoxy tree Fat, 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 Examples thereof include resins, polyvinyl butyral resins, terpene resins, phenol resins, aliphatic or alicyclic hydrocarbon resins, and one or more of these can be used in combination. In addition, when a toner is manufactured by polymerizing a raw material in the dispersoid 61 in a solidification section of a toner manufacturing apparatus described later, the above-mentioned resin material monomers, dimers, oligomers and the like are usually used.
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%.

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 particles 9 are small in size and shape variation between the particles, and have high circularity.

Any solvent can be used as long as it dissolves at least a part of the components constituting the dispersoid 61. However, the solvent can be easily removed in a solidifying part of a toner production apparatus as 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, and 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. As the colorant, for example, a pigment, a dye, or the like can be used. 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 Blue, 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 wax such as mineral wax, wax, paraffin wax, microwax, microcrystalline wax, petroleum wax such as petrolatum, wax, Fischer-Tropsch wax, polyethylene wax (polyethylene resin), polypropylene wax (polypropylene resin) ), Synthetic hydrocarbon waxes such as oxidized polyethylene wax, oxidized polypropylene wax, 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide, chlorinated hydrocarbons 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 a copolymer of n-stearyl acrylate-ethyl methacrylate).

  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 benzoic acid metal salts, salicylic acid metal salts, alkyl salicylic acid metal salts, catechol metal salts, metal-containing bisazo dyes, nigrosine dyes, tetraphenylborate derivatives, quaternary ammonium salts, 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.

In the dispersion 6, the dispersoid 61 is finely dispersed in the dispersion medium 62.
Although the average particle diameter of the dispersoid 61 in the dispersion liquid 6 is not specifically limited, It is preferable that it is 0.05-1.0 micrometer, and it is more preferable that it is 0.1-0.8 micrometer. When the average particle size of the dispersoid 61 is in such a range, the finally obtained toner particles 9 have a sufficiently high circularity and excellent properties and shape uniformity among the particles. It becomes.

  Although content of the dispersoid 61 in the dispersion liquid 6 is not specifically limited, It is preferable that it is 1-99 wt%, and it is more preferable that it is 5-95 wt%. When the content of the dispersoid 61 is less than the lower limit, the circularity of the finally obtained toner particles 9 tends to decrease. On the other hand, when the content of the dispersoid 61 exceeds the upper limit, depending on the composition of the dispersion medium 62 and the like, the viscosity of the dispersion 6 is increased, and the shape and size of the finally obtained toner particles 9 vary. It shows a tendency to increase.

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. In addition, when the dispersoid 61 is in a liquid form, variation in shape and size between the dispersoids 61 can be made particularly small. The variation in shape and size is particularly small.

  Further, 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, the dispersoid 61 dispersed in the dispersion medium 62 may have, for example, substantially the same composition among the particles or may have different compositions. For example, the dispersion 6 may include, as the dispersoid 61, one mainly composed of a resin material and one mainly composed of wax.
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 solidification part of the toner manufacturing apparatus 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.

Further, when the average particle size of the dispersoid 61 in the dispersion 6 is Dm [μm] and the average particle size of the toner particles 9 is Dt [μm], the relationship of 0.005 ≦ Dm / Dt ≦ 0.5 is established. It is preferable to satisfy, and it is more preferable to satisfy the relationship of 0.01 ≦ Dm / Dt ≦ 0.2. By satisfying such a relationship, a toner having a particularly small variation in shape and size among the particles can be obtained.
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 toner particles 9 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. Further, when a solvent is used for preparing the resin liquid, for example, at least a part of the solvent contained in the dispersoid 61 is obtained by, for example, heating the obtained dispersion liquid 6 after the dropwise addition as described above. May be removed. 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, it is possible to substantially prevent the organic solvent from volatilizing in the solidifying part of the toner manufacturing apparatus 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, the toner particles 9 can be obtained as a mixture of the constituent components more uniformly. 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 degassing treatment (subjected to a degassing step) before being used for discharge in a toner manufacturing apparatus described later. Thereby, the dissolved amount of the gas in the dispersion 6 can be reduced, and when the dispersion medium 62 is removed from the dispersion 6 discharged in the form of droplets in the solidification part of the toner manufacturing apparatus described later, It is possible to effectively prevent bubbles and the like from being generated in the dispersion liquid 6. 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. When the atmospheric pressure during the deaeration treatment is within such a range, dissolved gas can be efficiently removed while maintaining the shape of the dispersoid 61 in the dispersion 6 sufficiently.

[Toner production equipment]
The toner manufacturing apparatus 1 of the present invention includes a head unit 2 that discharges 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 the head unit 2. The unit 4 includes a solidifying unit 3 to which the dispersion 6 discharged from the head unit 2 is conveyed, and a collecting unit 5 for collecting the manufactured toner particles 9.

The dispersion liquid supply unit 4 stores the dispersion liquid 6 as described above, and the dispersion liquid 6 is fed into the head unit 2.
The dispersion liquid supply unit 4 may have any function as long as it has a function of supplying the dispersion liquid 6 to the head unit 2. Alternatively, the dispersion liquid supply unit 4 may have stirring means 41 for stirring the dispersion liquid 6 as illustrated. 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 portion 2.

The head unit 2 includes a dispersion liquid storage unit 21, a piezoelectric element 22, and a discharge unit 23.
The dispersion liquid storage section 21 stores the dispersion liquid 6 as described above.
The dispersion liquid 6 stored in the dispersion liquid storage unit 21 is discharged from the discharge unit 23 to the solidifying unit 3 by the pressure pulse of the piezoelectric element 22.
As described above, the present invention is characterized in that the dispersion liquid is used as the discharge liquid. Thereby, the following effects are obtained.

  That is, by using the dispersion liquid as the discharge liquid, when discharging the discharge liquid (dispersion liquid) from the discharge section, it is selectively cut at the portion of the dispersion medium having a microscopic viscosity and discharged as droplets. The For this reason, the size of the discharged dispersion liquid is small in size variation among the droplets. Accordingly, the finally obtained toner has a small variation in size among the particles (toner particles).

  And the droplet discharged from the discharge part becomes spherical shape immediately after discharge by the surface tension of the dispersion medium. Furthermore, the droplets composed of the dispersion liquid are excellent in shape stability even when being transported in the solidification section, and solidify while maintaining a substantially spherical shape. Therefore, the finally obtained toner (toner particles) has a high degree of circularity and a small variation in shape between the particles.

  On the other hand, when a solution or a melt is used as the discharge liquid, such an effect cannot be obtained. That is, since such a discharge liquid has a uniform viscosity even when viewed microscopically, when the liquid is discharged from the discharge portion, the so-called liquid breakage is likely to be in a bad state, and the liquid droplets are tailed. It tends to be a shape that pulls. Moreover, when it is conveyed in the solidification part, it tends to have a shape with a tail as described above. Therefore, when a solution or a melt is used as the discharge liquid, the finally obtained toner (toner particles) has large variations in size and shape between the particles, and the circularity of the toner particles is small. easy.

Although the shape of the discharge part 23 is not specifically limited, It is preferable that it is a substantially circular shape. Thereby, the sphericity of the discharged dispersion 6 and the formed toner particles 9 can be increased.
When the discharge part 23 is a substantially circular shape, the diameter (nozzle diameter) is, for example, preferably 5 to 500 μm, and more preferably 10 to 200 μm. When the diameter of the discharge part 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 discharge part 23 exceeds the upper limit, the discharged dispersion liquid 6 may entrap bubbles depending on the force relationship between the negative pressure of the dispersion liquid storage part 21 and the surface tension of the nozzle. There is sex.

Further, the vicinity of the discharge portion 23 of the head portion 2 (particularly, the inner surface of the opening of the discharge portion 23 and the surface on the side where the discharge portion 32 of the head portion 2 is provided (the lower surface in the figure)) is a dispersion liquid. 6 preferably has liquid repellency. Thereby, it can prevent effectively that the dispersion liquid 6 adheres to the discharge part 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 discharge portion, the stability of the shape of the discharged droplets is improved (the variation in shape and size between the droplets is small). The 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.

  Further, the vicinity of the discharge portion 23 of the head portion 2 (particularly, the inner surface of the opening of the discharge portion 23 and the surface on the side where the discharge portion 32 of the head portion 2 is provided (the lower surface in the drawing)) is hydrophobized. It is preferable that the treatment is performed. 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, but even if such water is used as a constituent material of the dispersion medium 62, the disadvantage is caused by the dispersion 6 adhering to the vicinity of the discharge portion. Is effectively prevented from occurring. Therefore, when the hydrophobic treatment is performed in the vicinity of the discharge portion 23 of the head portion 2, the dispersion liquid 6 substantially not containing or hardly containing an organic solvent can be suitably used. The toner can be produced by a method that hardly causes an adverse effect.

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, the piezoelectric element 22 has a configuration in which the piezoelectric body 222 is interposed between the upper electrode 223 and the lower electrode 221.
The piezoelectric element 22 functions as a vibration source, and the diaphragm 24 vibrates due to the vibration of the piezoelectric element (vibration source) 22 and has a function of instantaneously increasing the internal pressure of the dispersion liquid storage unit 21. It is.

  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, a state where no voltage is applied between the lower electrode 221 and the upper electrode 223 of the piezoelectric element 22. Then, 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 discharge unit 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 increases instantaneously, and the granular dispersion liquid 6 is discharged from the discharge unit 23.

  When one discharge of the dispersion liquid 6 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, a pressure (pressure in the positive direction) acting from the dispersion liquid supply unit 4 to the discharge unit 23 acts on the dispersion liquid 6. For this reason, air is prevented from entering the dispersion liquid storage part 21 from the discharge part 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. The

By applying the voltage as described above at a predetermined cycle, the piezoelectric element 22 vibrates and the granular dispersion liquid 6 is repeatedly discharged.
In this way, by performing discharge (injection) of the dispersion liquid 6 with 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 discharged dispersion liquid 6 can be discharged. The shape of is stable. As a result, it is possible to obtain a toner with small variation in shape and size between each particle (each toner particle), and to produce toner particles with high sphericity (geometrically perfect spherical shape). Can be made relatively easy.

  Further, by discharging (injecting) the dispersion liquid as described above, the vibration frequency of the piezoelectric body, the opening area (nozzle diameter) of the discharge portion, the temperature / viscosity of the dispersion liquid, the discharge amount of one drop of the dispersion liquid, The content of the dispersoid in the dispersion and the particle size of the dispersoid in the dispersion can be controlled relatively accurately, making it easy to control the toner to be manufactured to the desired shape and size. it can. 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 granular dispersion liquid discharged collides and aggregates, and can prevent the formation of irregular-shaped powder more effectively.
The initial velocity of the dispersion 6 discharged from the head unit 2 to the solidifying 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 liquid 6 is less than the lower limit, the productivity of the toner decreases. On the other hand, when the initial velocity of the dispersion 6 exceeds the upper limit, the sphericity of the toner particles 9 obtained 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 control the size of the discharged particles (granular dispersion liquid 6), and the variation of the obtained toner particles 9 may increase. is there. On the other hand, when the viscosity of the dispersion 6 exceeds the upper limit, the diameter of the formed particles increases, the discharge speed of the dispersion 6 decreases, and the amount of energy required for discharging the dispersion 6 tends to increase. Show. In addition, when the viscosity of the dispersion liquid 6 is particularly large, the dispersion liquid 6 cannot be discharged as droplets.

  Further, the dispersion 6 discharged from the head unit 2 may be preheated. 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, in the solidified portion 3 to be described later, the dispersoid 61 contained in the granular dispersion 6 is smoothly aggregated (fused), and the resulting toner particles 9 have a particularly high circularity.

Further, the discharge amount of one drop of the dispersion 6 is slightly different depending on the content of the dispersoid 61 in the dispersion 6, but is preferably 0.05 to 500 pl, and more preferably 0.5 to 5 pl. Is more preferable. By setting the discharge amount of one drop of the dispersion 6 within such a range, the toner particles 9 can be made to have an appropriate particle size.
Incidentally, the granular dispersion liquid 6 discharged from the head unit 2 is generally sufficiently larger than the dispersoid 61 in the dispersion liquid 6. That is, a large number of dispersoids 61 are dispersed in the granular dispersion liquid 6. For this reason, even if the dispersion of the particle size of the dispersoid 61 is relatively large, the ratio of the dispersoid 61 in the discharged granular dispersion liquid 6 is almost uniform for each droplet. Therefore, even when the particle size variation of the dispersoid 61 is relatively large, the toner particles 9 have a small particle size variation by making the discharge amount of the dispersion 6 substantially uniform. Such a tendency becomes more remarkable. For example, when the average particle diameter of the discharged dispersion liquid 6 is Dd [μm] and the average particle diameter of the dispersoid 61 in the dispersion liquid 6 is Dm [μm], the relationship of Dm / Dd <0.5 is satisfied. It is preferable to satisfy the relationship of Dm / Dd <0.2.

  Further, when the average particle size of the discharged dispersion 6 is Dd [μm] and the average particle size of the manufactured toner particles is Dt [μm], a relationship of 0.05 ≦ Dt / Dd ≦ 1.0 is established. It is preferable to satisfy, and it is more preferable to satisfy the relationship of 0.1 ≦ Dt / Dd ≦ 0.8. By satisfying such a relationship, it is possible to relatively easily obtain toner particles 9 that are sufficiently fine, have a high degree of circularity, and have a sharp particle size distribution.

  The frequency 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.

The toner manufacturing apparatus 1 having the illustrated configuration has a plurality of head portions 2. Then, a granular dispersion 6 is discharged from each of these head units 2 to the solidifying unit 3.
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, before the granular dispersion liquid 6 discharged from the adjacent head part 2 solidifies, it can prevent more effectively that a granular dispersion liquid collides and aggregates.

  Further, as shown in FIG. 2, the toner manufacturing apparatus 1 includes a gas flow supply unit 10, and the gas supplied from the gas flow supply unit 10 passes through the duct 101 to the head unit 2 -head. From each gas injection port 7 provided between the parts 2, it becomes the structure injected by a substantially uniform pressure. Thereby, the dispersion liquid 6 can be conveyed and solidified, maintaining the interval of the granular dispersion liquid 6 intermittently discharged from the discharge unit 23. As a result, collision and aggregation between the discharged granular dispersions 6 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 a gas flow that flows in substantially one direction (downward in the figure) in the solidifying unit 3. When such a gas flow is formed, the granular dispersion 6 (toner particles 9) in the solidifying unit 3 can be more efficiently conveyed.
In addition, an air current curtain is formed between particles ejected from each head unit 2 by ejecting gas from the gas ejection port 7, for example, a collision between particles ejected from adjacent head units, Aggregation can be prevented more effectively.

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 solidifying unit 3 can be solidified efficiently.
Further, when such a gas flow supply means 10 is provided, the solidification speed of the dispersion 6 discharged from the discharge unit 23 can be easily controlled by adjusting the supply amount of the gas 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 10 to 250 ° C., and preferably 15 to 200 ° 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 contained in the dispersion 6 is efficiently removed while maintaining the uniformity of the shape of the toner particles 9 obtained. The toner productivity can be particularly improved.

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, the solidifying unit 3 described later can efficiently remove the dispersion medium 62 contained in the dispersion 6, and toner productivity. Is further improved.
The granular dispersion 6 discharged from the head unit 2 becomes toner particles 9 by being solidified while being conveyed through the solidifying unit 3.

The toner particles 9 are obtained, for example, by removing the dispersion medium 62 from the discharged granular dispersion liquid 6. In such a case, the dispersoid 61 contained in the dispersion 6 aggregates as the dispersion medium 62 in the discharged dispersion 6 is removed. As a result, the toner particles 9 are obtained as an aggregate of the dispersoid 61. In addition, when the above-mentioned solvent is contained in the dispersoid 61, the said solvent is also normally removed in the solidification part 3. FIG.
The particle size of the dispersoid 61 contained in the dispersion liquid 6 is usually sufficiently smaller than the obtained toner particles 9 (the granular dispersion liquid 6 to be discharged). Therefore, the toner particles 9 obtained as an aggregate of the dispersoid 61 have a sufficiently large circularity.

  Further, when the toner particles 9 are obtained by removing the dispersion medium 61, the obtained toner particles 9 are usually smaller than the dispersion liquid 6 ejected from the ejection unit 23. For this reason, even when the area (opening area) of the discharge portion 23 is relatively large, the size of the toner particles 9 obtained can be made relatively small. Therefore, in the present invention, sufficiently fine toner particles 9 are obtained even if the head portion 2 is not obtained by performing special precision processing (even if it can be manufactured relatively easily). be able to.

Further, as described above, in the present invention, since the area of the discharge part 23 does not need to be extremely small, the particle size distribution of the dispersion 6 discharged from each head part 2 is relatively sharp enough. Can be. As a result, the toner particles 9 also have a small variation in particle size, that is, a sharp particle size distribution.
As described above, in the present invention, by using a dispersion as the discharge liquid, even when the particle size of the toner particles 9 to be produced is sufficiently small, the circularity is easily made sufficiently high. In addition, the particle size distribution can be sharp. As a result, the obtained toner has a uniform charge between the particles, and the toner thin layer formed on the developing roller is leveled and densified when the toner is used for printing. Become. As a result, defects such as fog are hardly generated and a sharper image can be formed. Further, since the shape and particle size of the toner particles 9 are uniform, the bulk density of the whole toner (aggregate of toner particles 9) can be increased. As a result, it is advantageous for increasing the amount of toner filled in the cartridge of the same volume and for reducing the size of the cartridge.

The solidified portion 3 is configured by 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 9 due to differences in manufacturing conditions can be reduced, and the reliability of the toner as a whole is improved.
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.

  The temperature (atmosphere temperature) in the solidified part 3 varies depending on the composition of the dispersoid 61 and the dispersion medium 62 contained in the dispersion 6, but is usually preferably 0 to 120 ° C., and 10 to 110 ° C. More preferably, it is 15 to 100 ° C. When the temperature in the solidified portion 3 is in such a range, the uniformity and stability of the shape of the obtained toner particles 9 are sufficiently high, and the dispersion medium 62 contained in the dispersion 6 is efficiently used. As a result, the toner productivity can be made particularly excellent. Further, since the toner particles 9 can be formed more smoothly, the toner manufacturing apparatus 1 can be reduced in size.

  In the illustrated configuration, the pressure in the housing 31 is adjusted by the pressure adjusting means 12. As described above, by adjusting the pressure in the housing 31, the dispersion medium 62 in the discharged dispersion liquid 6 can be efficiently removed, and the toner productivity is improved. In the configuration shown in the figure, the pressure adjusting means 12 is connected to the housing 31 by a connecting pipe 121. Further, an enlarged diameter portion 122 having an enlarged inner diameter is formed in the vicinity of the end portion of the connection pipe 121 connected to the housing 31, and a filter 123 for preventing the suction of the toner particles 9 and the like is further provided. ing.

  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 (the dispersion medium 62 is formed from the liquid dispersion 6 while sufficiently preventing generation of irregularly shaped toner particles 9 and the like. Solvent material) can be removed more smoothly.

  In the above description, the dispersion medium 62 is removed from the dispersion 6 in the solidifying unit 3, so that the dispersoid 61 in the granular dispersion 6 is aggregated (fused) to obtain toner particles 9. However, the toner particles 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), the toner particles 9 are obtained by advancing a polymerization reaction in the solidified portion 3. Such a method may be used.

The housing 31 is connected to voltage applying means 8 for applying a voltage. By applying a voltage having the same polarity as that of the granular dispersion 6 (toner particles 9) to the inner surface side of the housing 31 by the voltage application means 8, the following effects can be obtained.
Usually, the toner particles are positively or negatively charged. For this reason, when there is a charged substance charged with a polarity different from that of the toner particles, a phenomenon occurs in which the toner particles are electrostatically attracted and attached to the charged substance. On the other hand, if there is a charged material charged to the same polarity as the toner particles, the charged material and the toner particles repel each other, and the phenomenon that the toner adheres to the surface of the charged material can be effectively prevented. Therefore, by applying a voltage having the same polarity as that of the granular dispersion liquid 6 (toner particles 9) to the inner surface side of the housing 31, it is effective that the dispersion liquid 6 (toner particles 9) adhere to the inner surface of the housing 31. Can be prevented. As a result, the generation of irregularly shaped toner powder can be more effectively prevented, and the collection efficiency of the toner particles 9 can be improved.

  The housing 31 has a reduced diameter portion 311 in the vicinity of the collecting portion 5 that decreases in inner diameter in the downward direction in FIG. By forming such a reduced diameter portion 311, it is possible to efficiently collect the toner particles 9. As described above, the dispersion 6 discharged from the discharge unit 23 is solidified in the solidification unit 3, but such solidification is almost completely completed in the vicinity of the recovery unit 5, and the reduced diameter portion. In the vicinity of 311, problems such as agglomeration hardly occur even if each particle contacts.

The toner particles 9 obtained by solidifying the granular dispersion 6 are collected in the collection unit 5.
The toner obtained as described above may be subjected to various kinds of treatment such as heat treatment as necessary. Thereby, the joining of the fine particles derived from the dispersoid constituting the toner particles 9 is advanced, and the mechanical strength (mechanical stability) of the toner particles 9 can be further improved. Further, by performing such a heat treatment, the circularity of the toner particles 9 can be made particularly large.

In addition, the toner as described above may be subjected to various processes such as a classification process and an external addition process 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 2 to 20 μm, and more preferably 4 to 10 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.
Next, a second embodiment of the present invention will be described. Hereinafter, the present embodiment will be described with a focus on differences from the above-described embodiments, and description of similar matters will be omitted.
The toner manufacturing apparatus of the present embodiment has the same configuration as that of the first embodiment except that the configuration of the head unit is different.
FIG. 3 is a diagram schematically showing a structure in the vicinity of the head portion of the toner manufacturing apparatus of the present embodiment.

As shown in FIG. 3, in the toner manufacturing apparatus of the present embodiment, an acoustic lens (concave lens) 25 is installed in the head unit 2. 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 ejection unit 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 liquid 6 stored in the dispersion liquid storage unit 21 has a relatively high viscosity, it can be reliably discharged from the discharge unit 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 diameter of the toner particles 9 can be controlled to a relatively small value.
As described above, in this embodiment, the toner particles 9 can be controlled to have a desired shape and size even when a material having a higher viscosity or a material having a high cohesive force is used as the dispersion liquid 6. Therefore, the range of material selection is particularly wide, and a toner having desired characteristics can be obtained more easily.

  In the present embodiment, since the dispersion liquid 6 is ejected by the converged pressure pulse, the size of the dispersion liquid 6 to be ejected is relatively large even when the area (opening area) of the ejection portion 23 is relatively large. Can be small. That is, even when it is desired to make the particle size of the toner particles 9 relatively small, the area of the discharge portion 23 can be increased. Thereby, even if the dispersion liquid 6 has a relatively high viscosity, the occurrence of clogging or the like in the discharge unit 23 can be more effectively prevented.

The toner production method, toner, and toner production apparatus of the present invention have been described based on the preferred embodiments, but the present invention is not limited to this.
For example, each unit constituting the toner manufacturing apparatus of the present invention can be replaced with an arbitrary one that exhibits the same function, or another configuration can be added. For example, in the above-described embodiment, the configuration in which the granular dispersion liquid is discharged downward in the vertical direction has been described. However, the discharge direction of the dispersion liquid may be any direction such as vertically upward or in the horizontal direction. Moreover, as shown in FIG. 7, 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 liquid 6 changes depending on the gas flow, and is transported substantially at right angles to the discharge direction from the discharge unit 23.

Moreover, although the said 2nd Embodiment demonstrated the structure which used the concave lens as an acoustic lens, an 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.
Furthermore, in the said 2nd Embodiment, although the structure which interposed only the dispersion liquid 6 between the acoustic lens 25 and the discharge part 23 was demonstrated, as shown to FIGS. 4-6, for example, the acoustic lens 25 is shown. A diaphragm member 13 having a converging shape may be disposed between the nozzle and the discharge unit 23 toward the discharge unit 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 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 for discharging (injecting) the dispersion liquid, a method such as a spray drying method or a so-called bubble jet (“Bubble Jet” is a registered trademark) method is used, and “the dispersion liquid is pressed against a smooth surface with a gas flow. A method of injecting a dispersion liquid in the form of droplets (as fine particles) using a nozzle that draws the thin layer flow into a thin laminar flow and injects the thin laminar flow away from the smooth surface as fine particles (Japanese Patent Application 2002-2002). The method as described in the specification of US Pat. No. 3,218,89) may be used. The spray drying method is a method of obtaining liquid droplets by spraying (spraying) a liquid (dispersion) using a high-pressure gas. Moreover, as a method to which a so-called bubble jet (“bubble jet” is a registered trademark) method is applied, a method described in the specification of Japanese Patent Application No. 2002-169348 can be cited. That is, as a method for ejecting (injecting) the dispersion liquid, a “method for intermittently ejecting the dispersion liquid from the head portion by a change in gas volume” can be applied.

[1] Production of toner (Example 1)
First, polyester resin as a binder resin (glass transition point Tg: 62 ° C., softening point T _1/2 : 108 ° C., weight average molecular weight Mw: 9800): 100 parts by weight, phthalocyanine pigment (manufactured by Dainichi Seika Co., Ltd.) as a colorant Phthalocyanine blue): 5 parts by weight, Cr-salicylic acid complex as a charge control agent (Bontron E-81, manufactured by Orient Chemical Industries): 1 part by weight, carnauba wax as a wax: 3 parts by weight, tetrahydrofuran as a solvent (Wako Pure Chemicals) 300 parts by weight were prepared.

These components were mixed and dispersed with a ball mill for 10 hours to prepare a binder 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 weights while stirring at a rotation speed of 4000 rpm using a TK homomixer (manufactured by Tokki Kako). 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, tetrahydrofuran in the emulsion (dispersoid) is removed, then cooled to room temperature, and further ion-exchanged water is added to form a solid. A binder resin suspension (dispersion) in which fine particles were dispersed was obtained.

  Thereafter, the obtained binder resin suspension (dispersion) was degassed. The deaeration treatment was performed by placing the binder resin suspension (dispersion) in a stirred state in an atmosphere of 14 kPa for 10 minutes. The ambient temperature during the deaeration treatment was 25 ° C. The solid content (dispersoid) concentration in the binder resin suspension (dispersion) thus obtained was 10 wt%. The viscosity of the binder resin suspension (dispersion) at 25 ° C. was 2 mPa · s. Moreover, the average particle diameter Dm of the dispersoid constituting the binder resin suspension was 0.4 μm. The average particle size of the dispersoid was measured using a laser diffraction / scattering particle size distribution analyzer (LA-920, manufactured by Horiba, Ltd.).

  The degassed dispersion (binder resin suspension) was put into a dispersion supply section 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 discharge part to the solidification part. The discharge part had a circular shape with a diameter of 26 μm. Further, 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 discharge portion is used.

  Dispersion liquid is discharged at a dispersion 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 discharge part is 4 m / second, and one drop of the dispersion liquid discharged from the head part. The discharge amount was adjusted to 3 pl (particle size Dd: 18 μm, weight: about 3 ng). 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 100 ° C., humidity of 27% RH, and a flow velocity of 4 m / second is jetted vertically downward from the gas injection port, and the temperature in the housing (atmosphere temperature) is 20 It adjusted so that it might become -90 degreeC. The pressure in the housing (atmospheric pressure) was adjusted to be 100 to 105 kPa. The length of the solidified part (length in the transport direction) was 2 m.

In the solidification part, the dispersion medium was removed from the discharged dispersion liquid, and particles as aggregates of dispersoids were formed.
The particles formed in the solidified part were collected with a cyclone. The recovered particles had an average circularity R of 0.974 and a circularity standard deviation of 0.012. The volume-based average particle diameter Dt was 6.4 μm. The volume standard particle size standard deviation was 0.8 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). However, the circularity R is represented by the following formula (I).
R = L ₀ / L ₁ (I)
(Wherein, L ₁ [μm] is the circumference of the projected image of the 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 particle to be measured. Represents.)
To 100 parts by weight of the obtained particles, 1.0 part by weight of hydrophobic silica was added to obtain a final toner. The finally obtained toner had a volume-based average particle size of 6.5 μm.

(Comparative Example 1)
First, polyester resin as a binder resin (glass transition point Tg: 62 ° C., softening point T _1/2 : 108 ° C., weight average molecular weight Mw: 9800): 300 parts by weight, phthalocyanine pigment (manufactured by Dainichi Seika Co., Ltd.) as a colorant , Phthalocyanine blue): 15 parts by weight, Cr salt of salicylic acid as a charge control agent (Bontron E-81, manufactured by Orient Chemical Industries): 3 parts by weight, carnauba wax as wax: 9 parts by weight, toluene as a solvent (Wako Pure Chemical) 300 parts by weight were prepared.

These components were mixed and stirred while maintaining at 85 ° C. to prepare a binder resin solution (resin solution).
Thereafter, the obtained binder resin solution (resin solution) was degassed. The deaeration treatment was performed by placing the binder resin solution (resin solution) in a stirred state in an atmosphere of 14 kPa for 10 minutes. The ambient temperature during the deaeration treatment was 25 ° C. The viscosity of the binder resin solution (resin solution) thus obtained at 25 ° C. was 12 mPa · s.

Next, except that this binder resin solution was used in place of the binder resin suspension (dispersion liquid), it was discharged and solidified in the form of droplets in the same manner as in Example 1 above. A corresponding large number of particles were obtained.
To 100 parts by weight of the obtained particles, hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd., R-972): 2.0 parts by weight was added to obtain a final toner.

(Comparative Example 2)
A toner was manufactured in the same manner as in Example 1 except that the dispersion was not used as a discharge liquid without being subjected to a degassing treatment.
Table 1 shows the toner production conditions for the above examples and comparative examples.

[2] Evaluation The durability and transfer efficiency of each toner obtained as described above were evaluated.
[2.1] Durability The toner obtained in each of the above Examples and Comparative Examples was set in a developing machine 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.

[2.2] Transfer efficiency Transfer efficiency of each toner obtained as described above was evaluated.
The 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.

  Based on these results, average circularity R, circularity standard deviation, volume-based average particle diameter Dt, particle diameter of particles (toner mother particles, toner particles before adding silica) manufactured using a toner manufacturing apparatus Table 2 shows the standard deviation and the average circularity R of the finally obtained toner, the circularity standard deviation, the volume-based average particle diameter Dt, and the particle diameter standard deviation.

As is apparent from Table 2, the toner of the present invention (Example 1) had a large degree of circularity and a small width of the particle size distribution. Moreover, the variation in shape (standard deviation of circularity) was also small.
In contrast, the toner of the comparative example has a particularly small circularity, and a large number of toner particles having relatively large convex portions were observed. This is considered to be due to the following reasons.
That is, in Example 1, since the raw material discharged from the head part is a dispersion liquid (suspension), when it is discharged from the head part, it is selectively cut at the portion of the dispersion medium that is microscopically low in viscosity. And discharged as a discharge liquid. Further, since the aqueous dispersion medium has an appropriate surface tension, the discharge liquid becomes spherical immediately after discharge. In addition, since the dispersion liquid subjected to the deaeration process is used in Example 1, when the dispersion medium is removed from the dispersion liquid discharged in the form of droplets in the solidification unit, bubbles or the like are generated in the dispersion liquid. Generation | occurrence | production can be prevented effectively. As a result, it is possible to effectively prevent the toner particles (hollow particles, missing particles, etc.) having irregular shapes from being mixed into the finally obtained toner. The particles seem to have a uniform shape and a narrow particle size distribution. On the other hand, in Comparative Example 1, since the raw material used for manufacturing has a uniform viscosity even when viewed microscopically, the liquid droplet has a shape that draws a tail when ejected from the head portion. Cheap. In addition, since the toner of the comparative example is manufactured using a solution as a discharge liquid, the shape as described above (a shape with a tail) is maintained when the solvent is removed in the solidified portion. Solidify. For this reason, in Comparative Example 1, it is considered that toner particles having relatively large convex portions were generated. Further, in Comparative Example 2 using the dispersion liquid that has not been degassed, the amount of dissolved gas in the dispersion liquid is large, so that when the dispersion medium is removed in the solidification part of the toner production apparatus, the droplets When bubbles are generated in the liquid dispersion or when such bubbles are repelled, many irregularly shaped toner particles (hollow particles, missing particles, etc.) are generated. As a result, the shape and size of the toner particles are reduced. It is considered that the variation became large and the circularity of the toner particles was low.

  Further, as apparent from Table 2, the toner of the present invention was excellent in transfer efficiency. In contrast, the toner of the comparative example was inferior in transfer efficiency. This is because the toner of the comparative example has a large variation in shape, size, and characteristics among the particles, whereas the toner of the present invention has a variation in shape, size, and characteristics between the toner particles. This is probably due to being small enough. Further, the toner of the present invention had excellent durability, while the toner of the comparative example was inferior in durability.

1 is a longitudinal sectional view schematically showing a first embodiment of a toner manufacturing apparatus of the present invention. FIG. 2 is an enlarged cross-sectional view of the vicinity of the head portion of the toner manufacturing apparatus shown in FIG. 1. FIG. 6 is a diagram schematically illustrating a structure near a head portion of a toner manufacturing apparatus according to a second 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 ... Discharge part 24 ... Diaphragm 25 ... ... Acoustic lens 26 ... Pressure pulse converging part 3 ... Solidifying part 31 ... Housing 311 ... Reduced diameter part 4 ... Dispersing liquid supply part 41 ... Agitating means 5 ... Recovery part 6 ... Dispersing liquid 61 ... Dispersoid 62 ... Dispersion medium 7 ... Gas injection port 8 ... Voltage application means 9 ... Toner particles 10 ... Gas flow supply means 101 ... Duct 11 ... Heat exchanger 12 ... Pressure adjustment means 121 ... Connecting pipe 122 …… Expanded diameter part 123 …… Filter 13 …… Drawing member

Claims (39)

A dispersoid containing a raw material for toner production is a method for producing toner using a dispersion finely dispersed in a dispersion medium,
A degassing step of degassing the dispersion;
A method for producing a toner, comprising: a step of making the dispersion liquid subjected to the degassing treatment into fine particles, spraying from the head portion, solidifying the particles while transporting the inside of the solidifying portion, and granulating.   The toner manufacturing method according to claim 1, wherein the dispersion liquid is intermittently ejected by piezoelectric pulses.   The head section stores a dispersion liquid storage section that stores the dispersion liquid; a piezoelectric body that applies a piezoelectric pulse to the dispersion liquid stored in the dispersion liquid storage section; and a discharge section that discharges the dispersion liquid using the piezoelectric pulse. The method for producing a toner according to claim 1, wherein:   The method for producing a toner according to claim 3, wherein the discharge portion has a substantially circular shape and has a diameter of 5 to 500 μm.   The method for producing a toner according to claim 2, wherein the frequency of the piezoelectric pulse is 1 kHz to 500 MHz.   The method for producing a toner according to claim 1, wherein the dispersoid in the dispersion discharged from the head unit is aggregated when passing through the solidification unit.   The toner production method according to claim 1, wherein the degassing step is performed by placing the dispersion in an atmosphere of 80 kPa or less.   The method for producing a toner according to claim 1, wherein the dispersion medium is mainly composed of water and / or a liquid having excellent compatibility with water.   The toner manufacturing method according to claim 1, wherein the dispersion is a suspension.   The method for producing a toner according to claim 1, wherein the dispersion is prepared by introducing a material containing a resin or a precursor thereof into a liquid containing at least water.   2. The dispersion liquid is prepared through a mixing step of mixing a resin liquid containing at least a resin or a precursor thereof and a solvent capable of dissolving at least a part thereof and an aqueous liquid containing at least water. The method for producing a toner according to any one of Items 10 to 10.   The toner manufacturing method according to claim 11, wherein the mixing of the resin liquid and the aqueous liquid is performed by dropping droplets of the resin liquid into the aqueous liquid.   The method for producing a toner according to claim 11, wherein the dispersion is prepared by removing at least a part of the solvent after the mixing step.   The toner production method according to claim 13, wherein the solvent is removed by heating.   The method for producing a toner according to claim 1, wherein an average particle size of the dispersoid in the dispersion is 0.05 to 1.0 μm.   When the average particle size of the dispersoid in the dispersion is Dm [μm] and the average particle size of the toner particles to be produced is Dt [μm], the relationship of 0.005 ≦ Dm / Dt ≦ 0.5 is established. The toner production method according to claim 1, wherein the toner production method is satisfactory.   The toner manufacturing method according to claim 1, wherein a content of the dispersoid in the dispersion is 1 to 99 wt%.   18. The method for producing toner according to claim 1, wherein a discharge amount of one droplet of the dispersion discharged from the head portion is 0.05 to 500 pl.   When the average particle diameter of the dispersion liquid discharged from the head portion is Dd [μm] and the average particle diameter of the dispersoid in the dispersion liquid is Dm [μm], a relationship of Dm / Dd <0.5. The method for producing a toner according to claim 1, wherein:   When the average particle diameter of the dispersion liquid discharged from the head portion is Dd [μm] and the average particle diameter of the manufactured toner particles is Dt [μm], 0.05 ≦ Dt / Dd ≦ 1.0. The method for producing a toner according to claim 1, wherein the toner satisfies the relationship.   21. The toner manufacturing method according to claim 1, wherein the dispersion liquid discharged from the head portion is released into a gas flow flowing in substantially one direction.   The toner manufacturing method according to claim 1, wherein the dispersion liquid is discharged from a plurality of the head portions.   The toner manufacturing method according to claim 22, wherein the dispersion liquid is discharged while gas is ejected from between the head parts adjacent to each other.   24. The method for producing a toner according to claim 23, wherein the humidity of the gas ejected from between the adjacent head portions is 50% RH or less.   25. The method for producing toner according to claim 22, wherein the discharge timing of the dispersion liquid from at least two adjacent head portions is shifted.   26. The toner manufacturing method according to claim 1, wherein the dispersion liquid is discharged in a state where a voltage having the same polarity as that of the dispersion liquid is applied to the solidification portion.   27. The toner manufacturing method according to claim 1, wherein an initial speed of the dispersion liquid discharged from the head portion is 0.1 to 10 m / sec.   28. The toner manufacturing method according to claim 1, wherein the dispersion liquid has a viscosity of 0.5 to 200 [mPa · s] in the head portion.   The method for producing a toner according to claim 1, wherein the dispersion medium is removed in the solidification unit.   30. The toner manufacturing method according to claim 1, wherein the pressure in the solidified portion is 150 kPa or less.   31. The toner manufacturing method according to claim 1, wherein the dispersion liquid is discharged from the head portion in a heated state.   32. The toner manufacturing method according to claim 1, wherein the dispersion liquid discharged from the head part is heated by the solidification part.   A toner produced by the method according to claim 1.   34. The toner according to claim 33, having an average particle diameter of 2 to 20 [mu] m.   35. The toner according to claim 33 or 34, wherein the standard deviation of the particle diameter between the particles is 1.5 μm or less. 36. The toner according to claim 33, 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 toner particles 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 toner particles to be measured) Represents length)   37. The toner according to claim 33, wherein the standard deviation of the average circularity between the particles is 0.02 or less.   38. The toner according to claim 33, wherein the dispersoid is composed of aggregated aggregates.   A toner manufacturing apparatus, wherein the method according to claim 1 is performed.

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