JP2009258678A - Method of manufacturing toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a toner, in which a classifying step of coarse powder with a screen is easily carried out after a granulation step of mother toner particles and prior to an external additive mixing step, and to provide a method of manufacturing a toner, by which screening with a finer screen can be carried out and coarse powder is reliably prevented from mingling (jump-in), and further, to provide a method of manufacturing an electrophotographic toner for achieving a prolonged life of the screen. <P>SOLUTION: The method of manufacturing a toner includes at least: a granulation step of granulating mother toner particles in an aqueous medium; an external addition step of transferring an external additive onto the granulated mother toner particles; and a size distribution adjusting step of adjusting a size distribution of the particle diameters of the mother toner particles. The size distribution adjusting step is carried out in a screening step of eliminating coarse particles with a screen from a wet state (slurry) prepared by dispersing the mother toner particles in an aqueous medium. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a toner manufacturing method.

In an electrophotographic apparatus, an electrostatic recording apparatus, etc., a toner is attached to an electrostatic latent image formed on a photoreceptor, transferred to a recording medium, and then fixed on the recording medium by heat to form a toner image. Is forming. Also, full-color image formation generally involves color reproduction using four color toners of black, yellow, magenta, and cyan. Each color is developed, and each toner layer is superimposed on a recording medium. The toner image is heated and fixed at the same time, thereby forming a full-color image.
However, from the viewpoint of users who are familiar with printing, in general, images on full-color copiers are not yet satisfactory, and there is a demand for higher image quality that satisfies photography, high-resolution, and high resolution. It is known that a toner having a small particle size and a narrow particle size distribution is effective for improving the quality of a photographic image.

Conventionally, an electrical or magnetic latent image has been developed with toner. The toner used for developing the electrostatic image is generally colored particles in which a binder, a charge control agent, and other additives are contained in a binder resin. The toner production method is roughly classified into a pulverization method and a chemical method (for example, a spray drying method in which an organic solvent liquid in which a binder resin component is dissolved is sprayed into droplets and dried to prepare a spherical toner particle base material. , O / W emulsion method, polymerization method, partial polymerization method in which an organic solvent liquid in which a binder resin is dissolved is dispersed in an aqueous liquid medium in the form of droplets, and the solvent is removed therefrom to prepare a spherical toner particle base material Etc.). In the pulverization method, a colorant, a charge control agent, an anti-offset agent, etc. are melt-mixed in a thermoplastic resin and uniformly dispersed, and the resulting toner composition is pulverized and classified to produce a toner. is doing.
According to the pulverization method, it is possible to produce a toner having excellent properties to some extent, but there are limitations on the selection of the toner material. For example, a toner composition obtained by melt mixing must be capable of being pulverized and classified by an economically usable apparatus. From this demand, the melt-mixed toner composition must be sufficiently brittle. For this reason, when the toner composition is actually pulverized into particles, a high-range particle size distribution is likely to be formed, and if an attempt is made to obtain a copy image with good resolution and gradation, for example, A fine powder having a diameter of 3 μm or less and a coarse powder having a diameter of 10 μm or more must be removed by classification, which has a drawback that the yield becomes very low. Further, in the pulverization method, it is difficult to uniformly disperse additives such as a colorant and a charge control agent in the thermoplastic resin. Such non-uniform dispersion of additives adversely affects toner fluidity, developability, durability, image quality, and the like.

On the other hand, chemical methods for producing toner base particles in an aqueous medium such as a polymerization method and an emulsion dispersion method are known. As a polymerization method, a suspension polymerization method is known in which a monomer, a polymerization initiator, a colorant, a charge control agent, and the like are added to an aqueous medium containing a dispersant while stirring to form oil droplets and then polymerized. It has been. Also known is an association method in which particles obtained by emulsion polymerization or suspension polymerization are aggregated and fused.
By such a method, the toner particle size can be reduced and the particle size distribution can be made narrow, and classification may not be necessary. However, when a particle size distribution that does not require classification is achieved, when produced by these production methods, coarse particles are often generated due to generation of coarse particles due to condensation or aggregation, or peeling off of particles adhering to the wall surface on the pipe. This causes the transfer omission and the like and has an influence on the quality.
These coarse powders are removed by using a strainer in the granulation process. From the viewpoint of productivity, the strainer screen is at least 100 μm, which is more than 10 times the toner particle size, and is very coarse. A sufficient amount of coarse particles could not be obtained.
Furthermore, classification with a decanter or the like, and after drying, a classification process similar to the pulverization method may be performed to remove coarse powder (removal of the fine powder process), but classification is an unnecessary process. This is undesirable because the productivity is reduced due to the addition, and these processes are neumatic separation that does not allow the screen to pass through. Had an impact.

Moreover, as seen in Japanese Patent Application Laid-Open No. 4-121112 of Patent Document 2, coarse particles are removed by passing through a sieving step after mixing, such as applying vibration using a ball and sieving the powder. Although it is not impossible, it is not possible to perform a uniform external addition process with respect to the coarse particles due to mixing during the external addition process, resulting in poor charging and variations.
The present invention makes it possible to remove coarse particles from a toner base particle system before external addition (before addition of an external additive) by a simple process at a stage different from the conventional one.

An object of the present invention is to provide a toner manufacturing method that solves the above-described problems.
That is, an object of the present invention is to provide a production method in which a coarse powder classification step using a screen is simply performed after a toner base particle granulation step and before an external additive mixing step.
Another object of the present invention is to provide a method for producing a toner that enables sieving with a finer screen and reliably prevents the intrusion of coarse powder.
Furthermore, another object is to provide a method for producing an electrophotographic toner capable of extending the life of the screen.

The above-mentioned subject is achieved by (1) to (7) of the present invention.
(1) “At least a granulation step of granulating toner base particles in an aqueous medium, an external addition step of transferring an external additive to the granulated toner base particles, and a particle size distribution of the particle size of the toner base particles. A toner manufacturing method having a particle size distribution adjusting step for adjusting, wherein the particle size distribution adjusting step removes coarse powder by a screen from a wet state (slurry) in which the toner base particles are dispersed in an aqueous medium. A method for producing a toner, characterized in that it is performed in a sieving step ",
(2) “The particle size distribution adjusting step is characterized in that the screen is fixed in a cylindrical shape, and the slurry collides with the screen from the inside of the screen by centrifugal force to remove coarse particles in the toner. The method for producing the toner according to the item (1), "
(3) “The particle size distribution adjusting step is a step of removing coarse particles by vibrating the screen by causing the slurry to collide with the screen. The method for producing the toner according to the item),
(4) “The method for producing a toner according to (3) above, wherein the cylindrical screen is fixed while being inclined”,
(5) “Production of toner according to any one of (1) to (4) above, wherein the solid content concentration of the slurry to be added to the particle size distribution adjusting step is 10 to 40 wt%. Method",
(6) "The method for producing a toner according to any one of (1) to (5) above, wherein the viscosity of the slurry to be added to the particle size distribution adjusting step is 5 cps to 100 cps",
(7) “The method for producing a toner according to any one of (3) to (6) above, wherein an opening diameter of the screen is 3 to 36 μm”.

  As will be apparent from the following detailed and specific description, according to the present invention, there is provided a production method for simply performing a coarse powder classification step using a screen after the toner base particle granulation step and before the external additive mixing step. In addition, a method for producing a toner that enables sieving on a finer screen and reliably prevents the intrusion of coarse powder is provided, and further, an electrophotographic toner capable of extending the life of the screen is provided. An extremely excellent effect that a manufacturing method is provided is exhibited.

It is a schematic sectional drawing which shows an example of the classification apparatus used by this invention.

The present invention is described in detail below.
FIG. 1 is a schematic cross-sectional view of an example of a wet classifier used in the particle size distribution adjusting step (sieving step) of the present invention. In the classifying device of this example, the blade (12) rotates at a high speed inside the cylindrical screen (11). The blade (12) is fixed to the rotating shaft (12a), and the rotating shaft (12a) is disposed in the axial direction at the center of the inside of the cylindrical screen (11). It is supported by a non-bearing and is given rotational force by power means. The rotating shaft (12a) in the apparatus of this example is provided with a slurry supply port (13) for supplying the material to be classified into the cylindrical screen (11). In the wet classifier of this example, the classified toner is discharged from the toner collecting section (14), and the coarse particles are discharged from the coarse particle outlet (15). The cylindrical screen (11) of the classifying device of this example is not horizontally disposed, but is slightly inclined so that the slurry supply port (13) side is high and becomes lower toward the opposite end. Yes. However, it is needless to say that the classifying device according to the present invention is not essential to be arranged in such an inclination, and even if it is a horizontal type (horizontal direction arrangement type), it is a vertical type (upright with a rotating axis direction standing up). Type).

Further, in the present invention, the blade (12) and the slurry supply port (13) are not necessarily limited to those shown in FIG.
2 to 4 show photographs of still another apparatus according to the present invention. In the apparatus of FIG. 2, in FIG. 2, the slurry supply port is arranged horizontally, and the wing shape is spiral. However, it does not deny other shapes and structures of the blades. 3 and 4 are photographs of a state in which the periphery of the spiral portion located at the center of FIG. 2 is surrounded by a mesh. A screen that looks like a white cylinder is a screen. A slurry (an aqueous dispersion of base particles) is placed inside the screen, and the slurry that has passed through the opening of the screen is collected by sieving and used as a toner.

  In the present invention, a screen having an opening diameter of 3 to 100 μm can be used as the mesh size (mesh opening diameter) of the cylindrical screen (11), and the viscosity of the slurry, the solid content in the slurry, etc. Although it depends on conditions, it is preferably 3 to 36 μm, more preferably 3 to 20 μm.

  According to the classifying device of such a configuration example, intermittent vibration is given to the screen (11) as the blades (12) rotate, and the slurry is completely discharged into the screen surface. In combination, it is understood that vibration is sufficient and separation is promoted, and the period of vibration is the number of rotations of the rotating shaft (12a), the angle and height of the rotating blade (12), the gradient, etc. It is understood that it depends on.

  The slurry supplied from the slurry supply port (13) collides with the blade (12) to be agglomerated, collides with the screen (11) by centrifugal force, and the toner having a particle size below the mesh passes to the outside. The coarse particles are collected by the toner collecting part (14) and move inside the screen to be discharged from the coarse particle discharge port (15). Further, the screen (11) is clogged due to the vibration of the blade (12), which causes the slurry to collide with the screen irregularly due to the centrifugal force, so that the screen (11) strikes and vibrates with the rotation of the blade. Can be prevented.

  The characteristic of the classifier used in the present invention is that, first of all, classification can be performed in a slurry state. For this reason, since there is no aggregation due to charging, which occurs in the dry process, there is almost no clogging due to charging, and secondly, it becomes possible to loosen aggregation in a disperser or the like in advance, and further rotation Since the toner aggregation can be sufficiently solved with the blades, productivity reduction and clogging hardly occur due to the aggregation.

Another feature is that a strong centrifugal force is applied to the slurry containing the base particles to pass through the screen. In the conventional apparatus, toner is passed through the screen only by gravity in the dry type, and in the case of slurry, the productivity cannot be increased by using a screen fixed to the flow rate. I couldn't. However, in the apparatus used in the present invention, since the toner is given a stronger force to pass through the screen, it can be used on a screen having an opening that is almost the same as the toner particle size.
The blade (12) used in the classifying device according to the present invention may have, for example, a plurality of plate-shaped or semi-arc-shaped cross sections attached to the rotating shaft (12a) via stays (12c), and the rotational speed is The range is approximately 500 to 2000 rpm. Any known screen may be used, but a screen made of a resin such as polyester or amide is preferable because the opening can be made very small and a minute amount of vibration can be applied.

  In the classifying device of the present invention, all known dry toners can be sieved. In particular, it can exert great power in sieving small toner particles having a particle diameter of about 3 to 8 μm. These toners are usually screened using a screen having an opening of about 20 to 50 μm for the classification of coarse particles. However, the classification device in the present invention is not limited to this, and is sufficiently compatible with the classification at 5 μm. can do. Therefore, it can be used not only for sieving coarse particles but also for classifying coarse portions of the distribution.

The toner production method of the present invention is preferably applied to a chemical toner in which a liquid is used in the preparation of base particles, and in particular, a granulation step of granulating at least in an aqueous system, and an external additive to the granulated toner base particles More preferably, it is applied to the production of a toner having an external addition step in which the toner is transferred and a particle size distribution adjusting step for adjusting the particle size distribution of the toner base particle or toner powder system.
Although it is possible to use the particles obtained by the pulverization method, it is not preferred to bother to make a slurry and increase the number of processing steps. It is preferable to add a classification step to the toner granulated in the aqueous system.

  In particular, the toner is preferably a toner having a small particle diameter and a nearly spherical toner particle. As a method for producing such a toner, a suspension polymerization method in which an oil phase containing a binder resin component and / or a precursor thereof is emulsified, suspended, coagulated or aggregated in an aqueous medium to form toner base particles. (Including partial polymerization such as polymer molecular chain extension reaction, oligomer component polymerization, cross-linking and curing reaction, etc.), emulsion polymerization method, polymer suspension method and the like. Hereinafter, examples of these toner production methods and materials, additives, etc. used in the production methods will be described.

(Suspension polymerization method)
A colorant, a release agent and the like are dispersed in an oil-soluble polymerization initiator and a polymerizable monomer, and then emulsified and dispersed by an emulsification method described later in an aqueous medium containing a surfactant and other solid dispersants. Thereafter, after the polymerization reaction to form particles, a wet treatment for attaching the inorganic fine particles A to the toner particle surfaces in the present invention may be performed. At that time, it is preferable to treat the toner particles from which excess surfactant and the like are removed by washing.
Polymerizable monomers such as acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride, acrylamide, methacrylamide, diacetone Functional groups can be introduced on the surface of toner particles by using a part of acrylate or methacrylate such as acrylamide or these methylol compounds, vinyl pyridine, vinyl pyrrolidone, vinyl imidazole, ethyleneimine, dimethylaminoethyl methacrylate and other amino groups. .
Further, by selecting a dispersant having an acid group or a basic group as the dispersant to be used, the dispersant can be adsorbed and left on the particle surface to introduce a functional group.

(Emulsion polymerization aggregation method)
A water-soluble polymerization initiator and a polymerizable monomer are emulsified in water using a surfactant, and a latex is synthesized by an ordinary emulsion polymerization technique. Separately, a dispersion in which a colorant, a release agent and the like are dispersed in an aqueous medium is prepared, and after mixing, the toner is aggregated to a toner size and heat-fused to obtain a toner. Thereafter, a wet treatment of inorganic fine particles A described later may be performed. A functional group can be introduced on the surface of the toner particles by using a latex similar to the monomer that can be used in the suspension polymerization method.

(Polymer suspension method)
As an aqueous medium used in the polymer suspension method, water alone may be used, but a solvent miscible with water may be used in combination. Examples of miscible solvents include alcohols (methanol, isopropanol, ethylene glycol, etc.), cyclic ethers (tetrahydrofuran, dioxane, etc.), cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.), dimethylformamide, etc. Can be mentioned.
In the oil phase of the toner composition, a colorant such as resin, prepolymer and pigment, a release agent, a charge control agent and the like are dissolved or dispersed in a volatile solvent.
The oil phase composed of the toner composition is dispersed in an aqueous medium in the presence of a surfactant, a solid dispersant and the like, and the prepolymer is reacted to form particles. Thereafter, a wet treatment of inorganic fine particles A described later may be performed.
In order to introduce a functional group into the toner particles, a copolymer with a monomer having a functional group used in the suspension polymerization method, or a functional group of an acid group as an acid monomer in the case of a polyester resin is used. It can be obtained by using one having three or more or esterifying the terminal hydroxyl group of the obtained polyester resin with a compound having a plurality of acid groups. Further, as a dispersion stabilizer in an aqueous medium, which will be described later, an acid group-containing surfactant, polar polymer, organic or inorganic resin fine particles can be used, and an acid group can be introduced by remaining on the toner particle surface. Examples of the acid group include a carboxyl group, a sulfone group, a sulfonic acid group, and a phosphoric acid group.

  The toner of the present invention more preferably dissolves or dissolves at least a compound having an active hydrogen group, a polymer having a site capable of reacting with the active hydrogen group, a polyester, a colorant, and a release agent in an organic solvent. It is a toner obtained by subjecting a dispersed toner material liquid to crosslinking and / or elongation reaction in an aqueous medium. Hereinafter, the constituent material and the manufacturing method of the toner will be described.

(Modified polyester)
The toner according to the present invention contains modified polyester (I) as a binder resin. The modified polyester (I) refers to a state in which a bonding group other than an ester bond is present in the polyester resin, or resin components having different configurations are bonded to the polyester resin by a covalent bond, an ionic bond, or the like. Specifically, a functional group (site capable of reacting with an active hydrogen group) such as an isocyanate group that reacts with a carboxylic acid group or a hydroxyl group (active hydrogen group) is introduced into the polyester terminal, and further reacted with an active hydrogen-containing compound. , Refers to a modified polyester end.

  Examples of the modified polyester (I) include urea-modified polyester obtained by a reaction between a polyester prepolymer (A) having an isocyanate group and amines (B). As the polyester prepolymer (A) having an isocyanate group, a polyester having a polycondensate of a polyhydric alcohol (PO) and a polyvalent carboxylic acid (PC) and having an active hydrogen group is further added to a polyvalent isocyanate compound (PIC). And those reacted with. Examples of the active hydrogen group possessed by the polyester include a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group, and the like. Among these, an alcoholic hydroxyl group is preferable.

The urea-modified polyester is produced as follows.
Examples of the polyhydric alcohol compound (PO) include dihydric alcohol (DIO) and trihydric or higher polyhydric alcohol (TO). (DIO) alone or a mixture of (DIO) and a small amount of (TO) preferable. Examples of the dihydric alcohol (DIO) include alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (diethylene glycol) , Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol) F, bisphenol S, etc.); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol; Alkylene oxide bisphenol (ethylene oxide, propylene oxide, butylene oxide, etc.), etc. adducts. Among them, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use. The trihydric or higher polyhydric alcohol (TO) includes 3 to 8 or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (Trisphenol PA, phenol novolak, cresol novolak, etc.); and alkylene oxide adducts of the above trivalent or higher polyphenols.

  Examples of the polyvalent carboxylic acid (PC) include divalent carboxylic acid (DIC) and trivalent or higher polyvalent carboxylic acid (TC). (DIC) alone and (DIC) with a small amount of (TC) Mixtures are preferred. Divalent carboxylic acids (DIC) include alkylene dicarboxylic acids (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acids (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid) And naphthalenedicarboxylic acid). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. Examples of the trivalent or higher polyvalent carboxylic acid (TC) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). In addition, as polyhydric carboxylic acid (PC), you may make it react with polyhydric alcohol (PO) using the above-mentioned acid anhydride or lower alkyl ester (Methyl ester, ethyl ester, isopropyl ester, etc.). The ratio of the polyhydric alcohol (PO) to the polycarboxylic acid (PC) is usually 2/1 to 1/1, preferably as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. Is 1.5 / 1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.

Examples of the polyvalent isocyanate compound (PIC) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.) Aromatic diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanates; Those blocked with caprolactam or the like; and combinations of two or more of these.
The ratio of the polyvalent isocyanate compound (PIC) is usually 5/1 to 1/1, preferably as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. 4/1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. When the molar ratio of [NCO] is less than 1, when a urea-modified polyester is used, the urea content in the ester is lowered and hot offset resistance is deteriorated.

The content of the polyvalent isocyanate compound (PIC) component in the polyester prepolymer (A) having an isocyanate group is usually 0.5 to 40 wt%, preferably 1 to 30 wt%, more preferably 2 to 20 wt%. . If it is less than 0.5 wt%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40 wt%, the low-temperature fixability deteriorates.
The number of isocyanate groups contained per molecule in the polyester prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2 on average. Five. If it is less than 1 per molecule, the molecular weight of the urea-modified polyester will be low, and the hot offset resistance will deteriorate.

Next, as amines (B) to be reacted with the polyester prepolymer (A), a divalent amine compound (B1), a trivalent or higher polyvalent amine compound (B2), an amino alcohol (B3), an amino mercaptan (B4) ), Amino acid (B5), and amino acid block of (B1) to (B5) (B6).
Examples of the divalent amine compound (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′-dimethyldicyclohexyl). Methane, diamine cyclohexane, isophorone diamine, etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.) and the like. Examples of the trivalent or higher polyvalent amine compound (B2) include diethylenetriamine and triethylenetetramine. Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid. As (B6) which blocked the amino group of (B1) to (B5), ketimine compounds obtained from the amines and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.) of (B1) to (B5), And oxazolidine compounds. Among these amines (B), preferred are (B1) and a mixture of (B1) and a small amount of (B2).

The ratio of amines (B) is equivalent to the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the polyester prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). Is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2. When [NCO] / [NHx] is more than 2 or less than 1/2, the molecular weight of the urea-modified polyester is lowered, and the hot offset resistance is deteriorated.
The urea-modified polyester may contain a urethane bond together with a urea bond. The molar ratio of the urea bond content to the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance is deteriorated.

The modified polyester (I) used in the present invention is produced by a one-shot method or a prepolymer method. The weight average molecular weight of the modified polyester (I) is usually 10,000 or more, preferably 20,000 to 10,000,000, more preferably 30,000 to 1,000,000. The peak molecular weight at this time is preferably 1000 to 10000. When the molecular weight is less than 1000, the elongation reaction hardly occurs, the elasticity of the toner is small, and as a result, the resistance to hot offset deteriorates. On the other hand, when it exceeds 10,000, the problem in production becomes high in the deterioration of fixability, particle formation and pulverization. The number average molecular weight of the modified polyester (I) is not particularly limited when the unmodified polyester (II) described later is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. In the case of (I) alone, the number average molecular weight is usually 20000 or less, preferably 1000 to 10000, more preferably 2000 to 8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color device are deteriorated.
In the crosslinking and / or extension reaction between the polyester prepolymer (A) and the amines (B) to obtain the modified polyester (I), a reaction terminator is used as necessary to adjust the molecular weight of the resulting urea-modified polyester. be able to. Examples of the reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).

(Unmodified polyester)
In the present invention, not only the modified polyester (I) is used alone, but also the unmodified polyester (II) can be contained as a binder resin component together with the (I). By using (II) in combination, the low-temperature fixability and the glossiness when used in a full-color apparatus are improved, which is preferable to single use. Examples of (II) include polycondensates of polyhydric alcohol (PO) and polyvalent carboxylic acid (PC) similar to the polyester component of (I), and preferred ones are also the same as (I). . Further, (II) is not limited to unmodified polyester, but may be modified with a chemical bond other than a urea bond, and may be modified with a urethane bond, for example. It is preferable that (I) and (II) are at least partially compatible in terms of low-temperature fixability and hot offset resistance. Accordingly, the polyester component (I) and (II) preferably have similar compositions. When (II) is contained, the weight ratio of (I) to (II) is usually 5/95 to 80/20, preferably 5/95 to 30/70, more preferably 5/95 to 25/75, Particularly preferred is 7/93 to 20/80. When the weight ratio of (I) is less than 5%, the hot offset resistance is deteriorated, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

  The peak molecular weight of (II) is 1000-10000 normally, Preferably it is 2000-8000, More preferably, it is 2000-5000. If it is less than 1000, heat-resistant storage stability will deteriorate, and if it exceeds 10,000, low-temperature fixability will deteriorate. The hydroxyl value of (II) is preferably 5 or more, more preferably 10 to 120, and particularly preferably 20 to 80. If it is less than 5, it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. The acid value of (II) is preferably from 1 to 5, more preferably from 2 to 4. Since a high acid value wax is used as the wax, the low acid value binder leads to electrification and high volume resistance, so that it is easy to match the toner used for the two-component developer.

  The glass transition point (Tg) of the binder resin is usually 35 to 70 ° C, preferably 55 to 65 ° C. If the temperature is lower than 35 ° C., the heat-resistant storage stability of the toner deteriorates, and if it exceeds 70 ° C., the low-temperature fixability becomes insufficient. Since the urea-modified polyester is likely to be present on the surface of the obtained toner base particles, the toner of the present invention tends to have good heat storage stability even when the glass transition point is low, as compared with known polyester-based toners. Show.

(Coloring agent)
As the colorant, known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher, Yellow lead, Titanium yellow, Polyazo yellow, Oil yellow, Hansa yellow (GR, A, RN, R), Pigment yellow L, Benzidine yellow (G, GR), Permanent yellow (NCG), Vulcan fast yellow (5G, R) ), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Phi Se Red, parachlor ortho nitroa Lynn Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carnmin BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R , Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thio Indigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red, Po Azo Red, Chrome Vermilion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), indigo, ultramarine blue, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Phthalo Anine green, anthraquinone green, titanium oxide, zinc white, lithopone and mixtures thereof can be used. The content of the colorant is usually 1 to 15% by weight, preferably 3 to 10% by weight, based on the toner.

  The colorant can also be used as a master batch combined with a resin. As a binder resin to be kneaded with the production of the master batch or the master batch, a polymer of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyl toluene or the like, or a copolymer of these and a vinyl compound, Polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, fat Aromatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, paraffin waxes and the like can be mentioned, and these can be used alone or in combination.

(Charge control agent)
Known charge control agents can be used. For example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus Simple substance or compound, tungsten simple substance or compound, fluorine-based activator, salicylic acid metal salt, metal salt of salicylic acid derivative, and the like. Specifically, Bontron 03 of a nigrosine dye, Bontron P-51 of a quaternary ammonium salt, Bontron S-34 of a metal-containing azo dye, E-82 of an oxynaphthoic acid metal complex, E-84 of a salicylic acid metal complex , Phenolic condensate E-89 (above, Orient Chemical Industries, Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, Hodogaya Chemical Co., Ltd.), quaternary ammonium salt copy Charge PSY VP2038, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (Nippon Carlit) Manufactured), copper phthalocyanine, perylene, quinacridone, azo series Fee, a sulfonic acid group include polymer compounds having a functional group such as a carboxyl group. Of these, substances that control the negative polarity of the toner are particularly preferably used.
The amount of the charge control agent used is determined by the type of binder resin, the presence or absence of additives used as necessary, and the toner production method including the dispersion method, and is not uniquely limited. Preferably, it is used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the charge control agent is reduced, the electrostatic attraction with the developing roller is increased, the flowability of the developer is lowered, and the image density is lowered. Invite.

(Release agent)
As a release agent, a low melting point wax having a melting point of 50 to 120 ° C. works more effectively as a release agent in the dispersion with the binder resin between the fixing roller and the toner interface. The effect on high temperature offset is exhibited without applying a release agent such as oil. Examples of such a wax component include the following. Examples of waxes and waxes include plant waxes such as carnauba wax, cotton wax, wood wax, and rice wax, animal waxes such as beeswax and lanolin, mineral waxes such as ozokerite and cercin, and paraffin, microcrystalline, And petroleum waxes such as petrolatum. In addition to these natural waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax and polyethylene wax, and synthetic waxes such as esters, ketones, and ethers can be used. Furthermore, fatty acid amides such as 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide, chlorinated hydrocarbon, and low molecular weight crystalline polymer resin, poly-n-stearyl methacrylate, poly-n- A crystalline polymer having a long alkyl group in the side chain such as a homopolymer or copolymer of polyacrylate such as lauryl methacrylate (for example, a copolymer of n-stearyl acrylate-ethyl methacrylate, etc.) can also be used. .
The charge control agent and the release agent can be melt-kneaded together with the master batch and the binder resin, and of course, they may be added when dissolved and dispersed in the organic solvent.

  In common with any of these toner production methods, the granulating step according to the present invention can be performed after granulation.

This step is preferably performed after the toner particles are formed and the used surfactant and the like are removed by washing.
Excess surfactant present in water is removed by solid-liquid separation operations such as filtration and centrifugation, and the resulting slurry is redispersed in an aqueous medium.
At this time, the viscosity of the aqueous phase is preferably 5 cps to 300 cps, more preferably 5 cps to 100 cps. Even if it is less than 5 cps, the fine particles can be classified, but it is considered that the solid content is low, and the productivity may be deteriorated.
Further, if it exceeds 300 cps, the viscosity of the slurry is high, and when a screen having a fine opening is used, it is difficult to pass the slurry itself and the productivity is deteriorated.
The solid content concentration of the fine particles in the slurry is preferably 10 wt% to 40 wt%. For the same reason as above, when the amount is less than 10 wt%, the productivity is deteriorated, and when it exceeds 40 wt%, the viscosity is increased, and further, the aggregation of fine particles seen in a dry method is not sufficiently loosened and the efficiency is deteriorated. Because.
After these fine particles are prepared, classified and dried, an external additive may be added to the obtained fine particles.

(External additive)
As the external additive, inorganic fine particles such as a metal oxide, a metal carbide, a metal nitride, and a metal carbonate can be used. Specifically, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide Cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride and the like.
Furthermore, organic fine particles can be used as the external additive. Specifically, polymer-based fine particles, such as polystyrene obtained by soap-free emulsion polymerization, suspension polymerization, and dispersion polymerization, methacrylic acid ester and acrylic acid ester copolymer, polycondensation systems such as silicone, benzoguanamine, and nylon, heat Polymer particles made of a curable resin may be used.

Further, the external additive used in the toner of the present invention can be surface-treated to increase hydrophobicity and prevent deterioration of flow characteristics and charging characteristics even under high humidity. For example, silane coupling agents that may contain alkyl groups, fluorinated alkyl groups, titanate coupling agents, coupling agents such as aluminum coupling agents, silicone oils, higher fatty acids, fluorine compounds and the like are preferable surface treatment agents. Can be mentioned.
In particular, a silane coupling agent which is an example of a coupling agent is used for improving the degree of hydrophobicity and fluidity. Specifically, as the silane coupling agent, chlorosilane, alkoxysilane, silazane, special silylating agent and the like can be used, and alkoxysilane is more preferable. Examples of the alkoxysilane include vinyltrimethoxysilane, propyltrimethoxysilane, I-butyltrimethoxysilane, n-butyltrimethoxysilane, n-hexyltrimethoxysilane, n-octyltrimethoxysilane, and n-dodecyltrimethoxy. A silane etc. can be mentioned.
As the silicone oil, polydimethylsiloxane, polymethylphenylsiloxane, polydiphenylsiloxane or the like can be used, and fluorine-containing siloxane or the like may be used.
The fluorine compound is preferably an organosilicon compound having a fluorine atom, such as 3,3,4,4,5,5,6,6,6-nonafluorohexyltrichlorosilane, 3,3,3-trifluoropropyl. Trimethoxysilane, methyl-3,3,3-trifluoropropyldichlorosilane, dimethoxymethyl-3,3,3-trifluoropropylsilane, 3,3,4,4,5,5,6,6,6- Nonafluorohexylmethyldichlorosilane and the like can be mentioned.
Further, examples of higher fatty acids include stearic acid, oleic acid, palmitic acid, and linoleic acid, and metal salts of these higher fatty acids may be used. Specific examples include zinc stearate, aluminum stearate, copper stearate, magnesium stearate, calcium stearate, zinc oleate, manganese oleate, zinc palmitate, zinc linoleate, and calcium linoleate.

  In the toner of the present invention, the external additive is dry mixing in which inorganic / organic fine particles such as hydrophobic silica fine powder are externally added in a mixer together with a mixed medium such as glass beads. For mixing external additives, a general mixer is used, but it is preferable to equip a jacket or the like to adjust the internal temperature. The external additive is appropriately added at the beginning or in the middle. Examples of the mixer include a V-type mixer, a rocking mixer, a Roedige mixer, a Nauter mixer, and a Henschel mixer.

  Further, wet mixing is used in which the toner is externally added in a water-based and / or alcohol-based solvent. In this wet mixing, an external additive is added to the toner dispersed in an aqueous solvent and adhered to the toner surface. Further, when this external additive has been subjected to a hydrophobic treatment, it may be dispersed after a small amount of alcohol or the like is used in combination to lower the interfacial tension to facilitate wetting. Thereafter, the solvent can be removed by heating and fixed to prevent desorption. As a result, the external additive can be uniformly dispersed on the toner surface. Further, when the toner and the external additive are dispersed in the aqueous solvent, the external additive can be uniformly dispersed on the toner surface by adding the surfactant. Further, it is preferable to use an external additive or a surfactant having a polarity opposite to that of the toner.

  In the classification shown in FIG. 1 of Patent Document 2, it seems that the balls are vibrated to increase the efficiency of sieving for sieving the powder. Therefore, the ball is not used. It is possible to screen quickly without using a ball. Also, in the case of a slurry, it is assumed that unlike a powder, it is difficult to agglomerate, but it is possible to screen without clogging even if a mesh having a small opening diameter is used compared to the case of a powder. Furthermore, it can be well understood that the present invention is advantageous from the comparison between the following comparative example and the example.

  EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited thereto. In the following, “part” means part by weight, and “%” means weight%.

Hereinafter, a specific method for producing the toner according to the present invention will be described.
<Synthesis of resin fine particle emulsion>
In a reaction vessel equipped with a stir bar and a thermometer, 683 parts of water, 11 parts of sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30, manufactured by Sanyo Chemical Industries), 80 parts of styrene, 83 parts of methacrylic acid, When 110 parts of butyl acrylate, 12 parts of butyl thioglycolate and 1 part of ammonium persulfate were added and stirred for 15 minutes at 400 rpm, a white emulsion was obtained. The system was heated to raise the system temperature to 75 ° C. and reacted for 5 hours. Further, 30 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 5 hours. A dispersion was obtained. This is designated as [fine particle dispersion 1]. The volume average particle size of the [fine particle dispersion 1] measured by a laser diffraction particle size distribution analyzer (LA-920, manufactured by Shimadzu Corp.) was 120 nm. A portion of [Fine Particle Dispersion 1] was dried to isolate the resin component. The Tg of the resin was 42 ° C., and the weight average molecular weight was 30,000.

<Preparation of aqueous phase>
990 parts of water, 65 parts of [fine particle dispersion 1], 37 parts of a 48.5% aqueous solution of sodium dodecyl diphenyl ether disulfonate (ELEMINOL MON-7 manufactured by Sanyo Chemical Industries) and 90 parts of ethyl acetate were mixed and stirred to give a milky white color Obtained liquid. This is designated as [Aqueous Phase 1].

<Synthesis of non-reactive resin>
In a reaction vessel equipped with a condenser, a stirrer and a nitrogen inlet tube, 229 parts of bisphenol A ethylene oxide 2-mole adduct, 529 parts of bisphenol A propylene oxide 3-mole adduct, 208 parts terephthalic acid, 46 parts adipic acid and dibutyl 2 parts of tin oxide was added, reacted at 230 ° C. for 8 hours at normal pressure, and further reacted for 5 hours at a reduced pressure of 10 to 15 mmHg. Then, 44 parts of trimellitic anhydride was added to the reaction vessel, and 2 parts at 180 ° C. and normal pressure. Reacting for a time, polyester of non-reactive resin [A] was obtained. The non-reactive resin [A] had a number average molecular weight of 2500, a weight average molecular weight of 6700, Tg of 43 ° C., and an acid value of 24.

<Synthesis of intermediate polyester>
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 682 parts of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, trimellitic anhydride 22 And 2 parts of dibutyltin oxide were added, reacted at 230 ° C. for 8 hours at normal pressure, and further reacted for 5 hours at a reduced pressure of 10 to 15 mmHg to obtain [Intermediate Polyester 1]. [Intermediate Polyester 1] had a number average molecular weight of 2,100, a weight average molecular weight of 9,500, Tg of 55 ° C., an acid value of 0.5, and a hydroxyl value of 51.

-Synthesis of a modified polyester resin (hereinafter referred to as "prepolymer 1") capable of reacting with a compound having at least an active hydrogen group-
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introducing tube, 410 parts of the above [intermediate polyester 1], 89 parts of isophorone diisocyanate and 500 parts of ethyl acetate were added and reacted at 100 ° C. for 5 hours. ] Was obtained. [Prepolymer 1] had a free isocyanate weight% of 1.53%.

<Synthesis of ketimine>
In a reaction vessel equipped with a stirrer and a thermometer, 170 parts of isophoronediamine and 75 parts of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to obtain [ketimine compound 1]. The amine value of [ketimine compound 1] was 418.

<Synthesis of master batch>
1200 parts of water, 40 parts of carbon black (manufactured by Cabot, Regal 400R), 60 parts of the non-reactive resin [A] and 30 parts of water are further added and mixed with a Henschel mixer (manufactured by Mitsui Mining). Was kneaded at 150 ° C. for 30 minutes using two rolls, rolled and cooled, and pulverized with a pulverizer to obtain [Masterbatch 1].

(Fine particle preparation example 1)
<Creation of oil phase>
In a container equipped with a stir bar and a thermometer, 400 parts of the non-reactive resin [A], 110 parts of carnauba wax, and 947 parts of ethyl acetate are charged, heated to 80 ° C. with stirring, and maintained at 80 ° C. for 5 hours. After that, it was cooled to 30 ° C. at 1 hour. Next, 500 parts of [Masterbatch 1] and 500 parts of ethyl acetate were placed in a container and mixed for 1 hour to obtain [Raw material solution 1].
[Raw material solution 1] 1324 parts are transferred to a container, and using a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.), a liquid feeding speed is 1 kg / hr, a disk peripheral speed is 6 m / sec, and 0.5 mm zirconia beads are 80% by volume. The wax was dispersed under the conditions of filling and 3 passes. Next, 1324 parts of a 65% ethyl acetate solution of the non-reactive resin [A] was added, followed by one pass with a bead mill under the above conditions to obtain [Pigment / Wax Dispersion 1]. The solid content concentration of [Pigment / Wax Dispersion 1] (130 ° C., 30 minutes) was 50%.

<Emulsification>
[Pigment / Wax Dispersion 1] 648 parts, [Prepolymer 1] 154 parts, [Ketimine Compound 1] 8.5 parts in a container, TK homomixer (manufactured by Tokushu Kika) 1 After mixing for 1 minute, 1200 parts of [Aqueous Phase 1] was added to the container and mixed with a TK homomixer at a rotation speed of 10,000 rpm for 20 minutes to obtain [Emulsion Slurry 1].
That is, it is dispersed in an aqueous medium containing resin fine particles and an elongation reaction is performed.

<Desolvent>
[Emulsion slurry 1] was put into a container equipped with a stirrer and a thermometer, and after removing the solvent at 30 ° C. for 8 hours, aging was carried out at 45 ° C. for 4 hours to obtain [Dispersion slurry 1].

<Washing>
[Dispersion Slurry 1] After filtering 100 parts under reduced pressure,
(1): 100 parts of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered.
(2): 100 parts of a 10% aqueous sodium hydroxide solution was added to the filter cake of (1), mixed with a TK homomixer (30 minutes at 12,000 rpm), and then filtered under reduced pressure.
(3): 100 parts of 10% hydrochloric acid was added to the filter cake of (2), mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered.
(4): Add 300 parts of ion-exchanged water to the filter cake of (3), mix with TK homomixer (10 minutes at 12,000 rpm), and then filter twice, cake containing mother fine particles A A product was obtained.

<Surface treatment>
(1): Add 100 parts of ion-exchanged water to the filter cake of [mother fine particles A], and mix with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes).
When the solid content concentration and the slurry viscosity were measured, the solid content concentration was 29% and the slurry viscosity was 89 cps.
The particle size of the particles was measured with Coulter Multisizer III. Dv = 5.4 μm, Dv / Dn = 1.19, 3.17 μm or less 11.2%, 12.7 μm or more: 2.1% [Slurry 1].
When 200 parts of the above ion-exchanged water was added and the same procedure was performed as in [Slurry 1], the slurry concentration was 15% and the slurry viscosity was 43 cps.
The particle size of the particles was measured with Coulter Multisizer III. Dv = 5.4 μm, Dv / Dn = 1.19, 3.17 μm or less 11.0%, 12.7 μm or more: 2.3% [Slurry 2].

(Using classification device 1)
The slurry shown in FIG. 1 was used, and the above-mentioned slurry (1) was used, and a classifier having an opening of 36 μm (material nylon) and a total screen area of 3140 cm ² was used. Details and results are shown in Table 1.

(Using classification device 2)
A device similar to the classifier (1) (including the use of the slurry (1)) was used except that the mesh size was 10 μm (material polyester).

[Comparative Example 1]
Classifier (3) Use The slurry (1) was used, and classification was performed using a Sharpless p600 superdecanter (manufactured by Sharpless Co., Ltd.) and 350 g.
The classification device (3) in this example is a centrifuge, unlike the sieving device in the present invention. There is no screen.

[Comparative Example 2 (using classification device 4)]
A strainer having an opening of 36 μm (material SUS) and a screen area of 3000 cm ^{2 and} the slurry (1) were used.
The classification device (4) in this example does not use the sieving device of the present invention. Run the slurry over the screen and let the screen pass by gravity.

[Comparative Example 3]
Classification device (5) use Classification was performed using an elbow jet.
In this example, the particle | grains which filtered the slurry (1) and dried with the normal air dryer were used. The classifier (5) did not use the sieving apparatus in the present invention, but used an elbow jet (ordinary powder classifier). Further, not the slurry but the dried powder (not including the external additive) was classified.

[Comparative Example 4]
Use of classifier (6) An ultrasonic vibration sieve (manufactured by Co., Ltd.) having a mesh size of 36 μm (material SUS) and a screen area of 5024 cm ² was used.
In this example, particles obtained by filtering the slurry (1) and drying it with a normal air dryer were used. Classification was performed using an ultrasonic vibration sieve without using the sieve device in the present invention. Further, not the slurry but the dried powder (including the external additive) was classified.

[Comparative Example 5]
Classifier (7) Use A turbo screener (manufactured by Turbo Kogyo Co., Ltd.) having a mesh opening of 36 μ (material polyester) and a screen area of 2750 cm ² was used.
In this example, a powder obtained by mixing the external additive (hydrophobic silica 1%) with particles obtained by filtering the slurry (1) and drying with a forward air dryer was used. The sieve device in the present invention is not used. Further, not the slurry but the dried powder (including the external additive) was classified.

  As described above, the classification device (5) uses a dried product of each of the above slurries, and the classification devices (6) and (7) use the respective slurries to dry and solidify the fine particles 100. One part of hydrophobic silica (R972) was mixed with that of part by Henschel mixer 20L (Mitsui Mining Co., Ltd.) at 1400 rpm for 3 minutes.

  The same experiment as in Example 1 was performed using the slurry (2).

11 Screen 12 Blade 12a Rotating Shaft 13 Slurry Supply Port 14 Toner Collection Portion 15 Coarse Grain Discharge Port

Japanese Patent Laid-Open No. 2002-162772 JP-A-4-121112

Claims (7)

  At least a granulation step for granulating toner base particles in an aqueous medium, an external addition step for transferring an external additive to the granulated toner base particles, and a particle size distribution for adjusting the particle size distribution of the toner base particles A toner manufacturing method having an adjustment step, wherein the particle size distribution adjustment step is a sieving step of removing coarse powder by a screen from a wet state (slurry) in which the toner base particles are dispersed in an aqueous medium. A method for producing a toner, comprising:   The particle size distribution adjusting step is characterized in that the screen is fixed in a cylindrical shape, and slurry is collided with the screen by centrifugal force from the inside of the screen to remove coarse particles in the toner. A method for producing the toner according to the description.   3. The toner manufacturing method according to claim 1, wherein the particle size distribution adjusting step is a step of removing coarse particles by vibrating the screen by causing the slurry to collide with the screen.   The toner manufacturing method according to claim 3, wherein the cylindrical screen is fixed while being inclined.   5. The method for producing a toner according to claim 1, wherein a solid content concentration of the slurry to be supplied to the particle size distribution adjusting step is 10 to 40 wt%.   6. The method for producing a toner according to claim 1, wherein the viscosity of the slurry charged in the particle size distribution adjusting step is 5 cps to 100 cps.   The toner manufacturing method according to claim 3, wherein the screen has an opening diameter of 3 to 36 μm.

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