JP4086240B2 - Electrophotographic toner manufacturing apparatus, manufacturing method, and electrophotographic toner - Google Patents

Description

  The present invention relates to a method for producing an electrophotographic toner by a continuous emulsion polymerization method and a production apparatus used therefor.

Developers used in image forming processes such as electrophotography, electrostatic recording, and electrostatic printing include two-component developers composed of a carrier and a toner, and one-component developers that do not require a carrier (magnetic toner, Non-magnetic toners are known.
In the developing process, this toner is attached to an electrostatic charge image formed on an image carrier such as a photoconductor to form a toner image that visualizes the electrostatic charge image, and then the toner image is transferred to the transfer process. Then, the toner image is transferred from the image carrier to a transfer medium such as transfer paper, and then fixed in a fixing step, and finally an image of the toner image fixed on the transfer medium surface is obtained.

Conventionally, the toner is a finely pulverized powder prepared by melt-kneading a resin such as a styrene resin and polyester together with a colorant and the like, roughly pulverizing the obtained kneaded material, and then pulverizing and classifying the coarsely pulverized material. .
In general, in an image forming apparatus, toner is stirred with a carrier in a developing unit, when used as a one-component developer, contact between a developing roller and a toner supply roller, a layer thickness regulating blade, a friction charging blade, etc. Subject to various stresses such as contact.
In recent years, high-quality and high-quality images have been demanded. For this reason, improvements have been made by reducing the particle diameter of toner, but the toner obtained by ordinary kneading and pulverization methods has an irregular particle shape. However, due to the above stress, it is easy to be pulverized or generate fine particles, and as a result, an additive (also referred to as an external additive) adhered to the surface as a fluidizing agent is embedded inside the toner surface. As a result, the image quality deteriorates.
In addition, because of its shape, the fluidity of the powder is poor and a large amount of fluidizing agent is required, and the filling rate into a toner-filled container such as a bottle is lowered, which is an obstacle to downsizing the image forming apparatus. ing.
For these reasons, the advantage of the toner having a reduced particle size is not utilized, and the pulverization method has a limit in reducing the particle size.
In addition, an irregular shape such as pulverized toner is not so high in transferability, and this causes a problem such as a loss of transferred image and a large amount of toner consumption to compensate for it.

Under such circumstances, there has been an urgent need for the appearance of a toner that can further increase transfer efficiency, reduce consumption, and form a high-quality image without missing images, and reduce running costs.
In the case of toner with very good transfer efficiency, there is no amount of toner (untransferred toner) that remains on the photoconductor without being transferred to the transfer medium, so there is no need to install a cleaning unit. The apparatus can be reduced in size and cost, and there can be obtained an advantage that waste toner is eliminated.
In recent years, various spherical toner manufacturing methods have been studied in order to compensate for the disadvantages of such irregularly shaped toner.
Examples of the method for producing the spherical toner include a continuous emulsion polymerization method in which a toner composition comprising at least a resin and a colorant is dissolved or dispersed in an organic solvent, and the solution or dispersion is continuously emulsified in an aqueous medium. The spherical toner obtained by this method has a wide particle size distribution range with various particle sizes.
A toner having a wide particle size distribution and a non-uniform particle size causes various toner physical properties such as charge amount and melting speed to become non-uniform, causing image omission and offset. Therefore, in order to ensure high image quality and high durability, a toner having a sharp particle size distribution, that is, a toner having a small Dv / Dp is required.

Since the toner obtained by such a continuous emulsion polymerization method has a variation in particle size, a dry or wet classification step is required after the continuous emulsification step in order to obtain a toner having a predetermined particle size and particle size distribution. Usually done.
Ultrafine toner and coarse particle toner that are out of the specified particle size by classification are usually discarded or recycled as raw materials. However, when discarded, they are wasted and temporarily recycled. However, the recycling is not preferable because the number of processes increases and the cost increases.

  As a conventionally proposed example for obtaining a toner having a sharp particle size distribution by a continuous emulsion polymerization method, for example, a melt (a) of a resin having an ionic group and a colorant is neutralized with the ionic group. A method for producing a toner by finely dispersing fine particles in an aqueous medium (b) containing a substance by mechanical means and immediately cooling rapidly to form colored resin fine particles, and separating and drying the colored resin fine particles. As a mechanical means, a high-speed rotation type continuous emulsification in which a ring-shaped stator having a slit and a ring-shaped rotor having a slit are provided on the same axis so as to be engaged with each other while maintaining a slight gap. It has been proposed to use a disperser (see, for example, Patent Document 1). Also, using the high-speed rotation type continuous emulsification disperser described in Patent Document 1, a softening point of 120 ° C. or higher and a weight average A melt containing a linear polyester resin (A) having a molecular weight of 30,000 or more, a polyester resin (B) having a softening point and a weight average molecular weight lower than that of the resin (A), and a colorant (C) is obtained. A method of cooling and drying after dispersion in an aqueous medium while maintaining the molten state of (A) and resin (B) (see, for example, Patent Document 2) has been proposed. Since the continuous emulsification is carried out in a state of flow that circulates in the pipe as it is, the particle size distribution of the finished particles is not sharp and is not satisfactory.

JP-A-9-311502 JP 2002-14492 A

  In view of the above circumstances, an object of the present invention is to produce a toner having a sharp particle size distribution width necessary for obtaining a high-quality and high-quality image by an emulsion polymerization method without waste. An apparatus and a manufacturing method using the same are provided.

According to the present invention, there is provided a method for producing an electrophotographic toner comprising the steps of dissolving or dispersing a toner composition comprising at least a resin and a colorant in an organic solvent and continuously emulsifying the dissolved or dispersed material in an aqueous medium. In the continuous emulsification process, when a centrifugal force is applied to the emulsion (the solution or dispersion dispersed in an aqueous medium, also referred to as a slurry), the centrifugal force causes the emulsion in the emulsification stage. It is possible to efficiently produce particles having a predetermined particle size.
That is, the emulsifier installed in the process of continuous emulsification is provided with an intake and an outlet for the emulsion, and piping for circulating the emulsion is provided in front of and behind the emulsifier and connected to the inlet / outlet. However, in the present invention, before the emulsion is supplied to the emulsifier, if a centrifugal force is applied to the emulsion in the pipe connected to the intake port of the emulsifier, coarse particles and pipes are formed on the tube inner wall side. A flow in the tube in which fine particles are unevenly distributed in the central portion occurs, and the fine particles gathered in the central portion of the tube cause agglomeration of the fine particles and grow into particle diameter particles within a predetermined range.
Furthermore, a mechanism having a rotating part (referred to as an axial flow generating mechanism) that generates an axial flow that gives a shearing force is installed after the installation part of the mechanism that applies the centrifugal force, and the blades of the rotating part, for example, rotate. Then, since the peripheral speed is larger in the vicinity of the outer periphery of the rotating portion than in the vicinity of the rotating shaft, a larger shear force is given to the emulsified liquid flowing in the vicinity of the rotating portion shaft by the emulsified liquid flowing in the vicinity of the rotating portion outer periphery. Thus, large particles can be refined.
It has been found that by these actions, the generation of fine particles and coarse particles in the continuous emulsification process can be suppressed, and predetermined internal particle diameter particles having a sharp particle size distribution width can be obtained efficiently.

An object of the present invention is to provide an electrophotographic process comprising (1) the step of “1)“ dissolving or dispersing a toner composition containing at least a resin and a colorant in an organic solvent and continuously emulsifying the dissolved or dispersed material in an aqueous medium. A method for producing a toner, wherein the continuous emulsification step includes a step of applying a centrifugal force to an emulsion containing the solution or dispersion and an aqueous medium, and a step of applying a shearing force to the emulsion. step of providing a centrifugal force to the emulsion, the emulsion along the pipe inner wall is intended to provide a centrifugal force to the emulsion flow in a spiral shape, is a set of small particles near the center of the pipe, said small grains And a process for producing a shearing force on the emulsion, and a method for producing a toner for electrophotography, characterized in that the centrifugal force applied to the particles in the emulsion is 500 G or more. (1) characterized in that And (3) “By applying centrifugal force, the emulsified liquid in the pipe has a distribution in which the proportion of fine particles increases from the pipe wall toward the center of the pipe. The method for producing an electrophotographic toner according to (1) or (2), wherein the shearing force is applied after the step of applying the centrifugal force. Using a pipe in which a mechanism (referred to as an axial flow generation mechanism) having a rotating part that generates the axial flow to be applied is installed, the vicinity of the rotating part becomes larger than the vicinity of the rotating axis generated by the rotation of the rotating part. Due to the difference in peripheral speed, a step of applying a large shearing force to the emulsion flowing in the vicinity of the rotating part axis to the emulsion flowing in the vicinity of the rotating part outer periphery to reduce the large particles to a predetermined particle size. Item (1) above characterized in that Itaru first (3) preparation of electrophotographic toner according to any one of items ", (5)" rotation direction of flow of the emulsion which centrifugal force is applied by the step of providing a centrifugal force, axial flow generating The method for producing an electrophotographic toner according to any one of (1) to (4) above, wherein the rotation direction is opposite to the rotation direction of the rotating portion of the mechanism ”, (6)“ Emulsification ” The electrophotographic toner according to any one of (1) to (5) above, wherein after the step, the particles in the liquid are taken out and the steps of washing, drying, and classification are sequentially performed. Achieved by "manufacturing method".
Further, the above-mentioned problem is (7) “electrophotographic toner produced by the production method according to any one of (1) to (6)” of the present invention. (8) “The electrophotographic toner according to (7) above, wherein the volume-based volume average particle diameter (Dv) obtained from the volume distribution is 3 to 10 μm”, (9) “ The value (Dv / Dp) obtained by dividing the volume average particle size (Dv) by the number-based number average particle size (Dp) obtained from the number distribution is 1.05 to 1.25. It is achieved by the “electrophotographic toner according to item 7) or (8)”.
Further, the above-mentioned problem is (10) “electrophotographic toner in which a toner composition containing at least a resin and a colorant is dissolved or dispersed in an organic solvent, and the solution or dispersion is continuously emulsified in an aqueous medium. The continuous emulsifying means includes a means for applying a centrifugal force to the emulsion containing the dissolved or dispersed material and the aqueous medium, and a means for applying a shearing force to the emulsion. The centrifugal force is applied to the emulsion by spirally flowing the emulsion along the inner wall of the pipe to give the emulsion a centrifugal force. The small particles are assembled near the center of the pipe , and the small particles are combined. is of electrophotographic toners production apparatus ", characterized in that those sent to means for applying a shearing force to the emulsion, (11) pipe that gives" a centrifugal force to the emulsion in the inner wall in a spiral Jo突 electromotive It is intended one lifting and piping Wherein characterized in that it is intended to incorporate part of the pipe in a continuous emulsifying device or to all the (10) electrophotographic toner production apparatus according to claim ', (12) "spiral in the pipe The electrophotographic toner production apparatus according to item (10) or (11), wherein a mechanism for generating a flow is incorporated in the emulsification apparatus, and (13) “centrifugal force” A mechanism (referred to as an axial flow generation mechanism) that generates an axial flow that applies a shearing force and has a rotating part (referred to as an axial flow generation mechanism) is disposed after the position where the mechanism that provides the rotation is provided. The electrophotographic toner manufacturing apparatus according to any one of Items 1 to (12) ”, (14)“ The axial flow generation mechanism is a pipeline homomixer ” Achieved by "Electrophotographic Toner Manufacturing Equipment" That.
In addition, the above-described problem is the image forming apparatus according to (15) of the present invention, wherein the toner for electrophotography according to any one of (7) to (9) is accommodated in the developing unit. Is achieved.
In addition, the above-described object is achieved by (16) “an image forming method using the electrophotographic toner according to any one of (7) to (9)” of the present invention. The

  With the production apparatus and production method of the present invention, it is possible to efficiently produce a toner having a sharp particle size distribution effective for obtaining a high-quality image.

FIG. 5 is a schematic diagram showing a process flow of a continuous emulsification method that is currently generally performed as a known construction method.
In FIG. 5, (001) and (002) are an [A oil phase] tank and a [B oil phase] tank in which the toner material is dissolved or dispersed in an organic solvent, respectively (003) [Water phase] tank for charging and emulsifying a dissolved or dispersed material.
These [A oil phase], [B oil phase] and [aqueous phase] are quantitatively fed from each tank by a feed pump (004), and [A oil phase] and [B oil phase] are mixed with the same static mixer ( 005) to allow both solutions to mix uniformly.
After the mixed solution of [A oil phase] and [B oil phase] and [aqueous phase] merge, the mixture is fed into an emulsifier (007) via a circulation pipe and emulsified. When the inside of the cooler (006) is passed through the circulation pipe, the temperature rise can be prevented.
Thereafter, a part of the emulsion is poured into the recovery tank (008) via a circulation pipe and collected as a product, and the remaining emulsion is recirculated through the circulation pipe in the continuous emulsification process to finally collect the toner. Discharged into the tank.
The continuous emulsification step is an emulsification performed after the mixed liquid of [A oil phase] and [B oil phase] and [aqueous phase] are joined and before the emulsified liquid is collected in the recovery tank. This means a process including emulsification in a machine, cooling in a cooler, and feeding and circulation of an emulsion using a circulation pipe.

  According to such a conventional process, as described above, the resulting particles have a broad particle size distribution, and when used as an electrophotographic toner, a high-quality image cannot be obtained. In general, wet or dry classification is performed in a subsequent process to remove particles having a particle size outside the predetermined range, thereby narrowing the particle size distribution width.

In the emulsification process, a toner composition consisting of a resin and a colorant dissolved or dispersed in an organic solvent is continuously introduced into a continuous emulsification pipe together with an aqueous medium, and installed in the continuous emulsification pipe as an axial flow generation mechanism. The toner composition is dispersed as fine oil droplets in the aqueous medium by a large shearing force generated in a narrow gap between the rotating portion of the rotating blade and the fixed portion of the rotating blade, such as a pumped pump. At this time, the particle size is increased or decreased depending on the shearing force applied to the toner composition.
FIG. 6 shows a schematic diagram of an example of an emulsifier (pipeline homomixer) provided with such an axial flow generation mechanism.

It is possible to control the average particle size of the particles by controlling the number of rotations of the rotating part constituting the liquid feeding means, but the particle size distribution is broad even if emulsification is carried out with a certain number of rotations. Often becomes. This is considered to be caused by various shapes, structures, operating conditions, and the like of the rotating part, for example, the rotating blade, with which the toner composition comes into contact.
That is, in the rotating blade, almost no shearing force is applied to the toner composition passing around the rotation axis due to the difference in peripheral speed, the size of the gap with the fixed portion, etc. This is because the peripheral speed is high and a large shear force is applied. However, this is based on the premise that the liquid feeding means having a shearing function generates an axial flow.
In the axial flow, the fluid entering the central part of the rotating blade is discharged through the central part of the rotating blade, and the fluid entering the peripheral part of the rotating blade is discharged through the peripheral part of the rotating blade. It is formed so that.
The liquid feeding means having such a function can selectively apply the shear force bias as described above to the fluid. On the other hand, in other types of liquid feeding means, such as a centrifugal pump, there is no such bias in liquid feeding, and the liquid near the center of the rotating blade and the liquid near the outer periphery of the rotating blade are mixed. To be liquidated.

  Therefore, the present inventors made the difference in the shearing force on the same rotating blade for the purpose of reducing the generation of fine particles and coarse particles as much as possible in the continuous emulsification process step and producing particles having a sharp particle size distribution. Focus attention and study diligently, using liquid feeding means as an axial flow generation mechanism to concentrate coarse particles that need to be subjected to a large shearing force in the vicinity of the outer periphery of a rotating blade with a large shearing force, and to apply a further shearing force We considered to concentrate fine particles that do not need to be concentrated in the vicinity of the rotation axis, which is difficult to receive shearing force.

In the continuous emulsification circulation pipe, in parallel with the above-described emulsification dispersion due to the shearing force effect, there is also an effect that the particles are united and enlarged.
That is, in the concentration process of the fine particles, since the fine particles have a large specific surface area, the attractive force between the surfaces is strong and the particles are likely to be combined. It is also possible to concentrate fine particles that are easy to coalesce and coalesce the fine particles to grow fine particles that have a predetermined outer particle diameter to a predetermined inner particle diameter.
With these two effects, it is possible to efficiently obtain particles having a predetermined inner particle diameter having a sharp particle size distribution.
As a result of investigations based on such an idea, the present inventors, as a result of giving a centrifugal effect to the emulsion liquid in the pipe in the continuous emulsification process, the particle size distribution of the pipe slurry liquid is non-uniform, that is, the pipe cross section. It was confirmed that there can be a bias in the radial direction.
In this way, the coarse particles that are biased in the particle size distribution and concentrated near the inner wall of the tube are given a large shear force on the blade tip of the rotating part by the axial flow generation mechanism provided in the continuous emulsification pipe. It became possible to make it smaller and to approach the predetermined internal particle size. On the other hand, the coalescence of the fine particles is promoted so that a large amount of fine particles are present at the center of the tube, and it becomes possible to approach the predetermined internal particle size.
According to the present invention based on these functions, it is possible to produce a predetermined inner particle size particle having a sharp particle size distribution width with less waste.

According to the present invention, as described above, a powder having a sharp particle size distribution, particularly a toner, is obtained by a continuous emulsion polymerization method by incorporating a mechanism for providing a centrifugal effect in a pipe connected to an inlet of an emulsifier in a continuous emulsification process. This makes it possible to obtain particles efficiently.
A process incorporating a mechanism for giving a centrifugal effect to the continuous emulsification process, which is a feature of the present invention, will be described.

FIG. 3 is a schematic view showing a process flow for explaining the continuous emulsification process of the present invention, in which a mechanism for giving a centrifugal effect is incorporated.
In FIG. 3, the conventional continuous emulsification step described with reference to FIG. 5 is used except that a mechanism (009) for providing a centrifugal effect is provided in the pipe connected to the inlet of the emulsifier (007). The various means are the same.

Various known mechanisms can be applied as a mechanism for applying a centrifugal force in the continuous emulsification step used in the method for producing an electrophotographic toner of the present invention.
For example, the electrophotographic toner production apparatus of the present invention can be effectively used when a part of or the entire inner wall of a pipe used in the continuous emulsification process is provided with a spiral protrusion or groove. Can be implemented.
FIG. 2 is a schematic view showing the inside of a part of a spiral pipe as an example of a mechanism that brings about a centrifugal effect.
FIG. 3 is a schematic view showing a flow of a continuous emulsification process in which the cyclone type mechanism shown in FIG. 4 is incorporated at the position (010) in the pipe connected to the inlet of the emulsifier (007). .
Of course, not limited to such a mechanism, for example, a mechanism provided with a mechanism for ejecting the emulsified liquid vigorously along the cylindrical tube wall may be used.
As the discharge mechanism, various known ones can be applied. For example, various pumps such as a centrifugal pump, a mixed flow pump, an axial flow pump, and a vortex pump can be applied, and the kind thereof is not limited.
Anyway, what is necessary is just to give the centrifugal effect by flowing the emulsion in a spiral shape in the pipe which is a feature of the present invention.

In this way, when the emulsion is spirally flowed in the pipe and centrifugal force is applied to the particles in the emulsion, the centrifugal force acts less in the center of the pipe when viewed from the pipe cross-section direction in the pipe. Many fine particles with small self-weight are gathered, and conversely, many coarse particles with large self-weight are gathered near the inner wall of the tube away from the center.
In order to classify the particle diameter by such centrifugal force, it is desirable to apply a large centrifugal force for a relatively short time, and the applied centrifugal force is preferably 500 G or more. When the applied centrifugal force is 500 G or less, it becomes difficult to give a sufficient centrifugal effect to the particles in the pipe, so the effect of the present invention is reduced.
As is generally well known, as described above, since the fine particles have a large specific surface area, the particles are easy to coalesce. Therefore, the fine particles are concentrated near the center of the tube by the centrifugal effect. It is one of the features of the present invention that the particles are combined to increase the particle size and approach the predetermined internal particle size.

Another feature of the present invention is that an axial flow generating means is installed after the mechanism for giving a centrifugal effect to the slurry liquid.
As the axial flow generating means, various known devices can be applied, but an axial flow type shearing device is optimal. An example of an applicable device is T.I. K. A pipeline homomixer (manufactured by Special Machine Industries Co., Ltd.) can be mentioned.
The particles in the slurry liquid circulating in the continuous emulsification pipe are put into the circulation part as a continuous liquid, and a strong shearing force is generated in the narrow gap formed between the rotating part and the fixed part of the liquid feeding means such as a pump. Is converted into particles.
At this time, the shear force applied to the particles increases as the peripheral speed of the rotating portion increases. That is, even in the same rotating part, since the shearing force near the outer periphery of the rotating part is larger than the shearing force near the rotating axis, the shearing force applied to the particles is non-uniform even on the same rotating part. Variation in diameter occurs. Those subjected to a strong shear force become finer than those subjected to a weak shear force.
During circulation in the continuous emulsification pipe, it is desirable to selectively apply a larger shearing force to coarse particles, and it is necessary to reduce the shearing force applied to fine particles that are sufficiently or more fine than necessary as much as possible.
When the fine particles are concentrated in the central portion of the tube and the coarse particles are concentrated near the inner wall of the tube due to the centrifugal effect in the continuous emulsification pipe, it is possible to apply such a selective shearing force.

Furthermore, in the present invention, depending on the combination of the rotational direction of the spiral flow of the emulsified liquid and the rotational direction of the rotating blades in the apparatus that generate the axial flow, the degree of the effect will be affected. The rotation direction of the spiral flow of the emulsified liquid and the rotation direction of the rotating blades in the apparatus that generate the axial flow can be applied in the same direction or in the reverse direction.
In the reverse direction, the relative speed of the emulsion and the rotating blade is greater than that in the same direction. Therefore, it is possible to receive a larger shearing force at the moment when the rotating blade receives the shearing force. By this action, for example, it is effective to use a combination in the opposite direction for a toner formulation that requires a high shearing force during emulsification. Needless to say, the present invention is not limited to this example, and any effect generated from the influence of the difference between the flow direction in the same direction and the reverse direction can be obtained.

  According to the production method of the present invention, it is possible to suppress the probability of occurrence of fine particles and coarse particles, and to produce particles having a predetermined inner diameter with high yield. Moreover, although fine particles and coarse particles are usually discarded, the amount of waste can be reduced, which is also effective for energy saving.

The toner obtained by the method of the present invention is preferably 10 μm or less because the smaller the volume-based volume average particle diameter (Dv) obtained from the volume distribution, the better the fine line reproducibility of the image.
However, since the cleaning property tends to decrease as the particle size decreases, it is preferably at least 3 μm. In particular, if 20% or more of toner of 2 μm or less is present, the amount of toner having a small particle size that is difficult to be developed on the surface of the magnetic carrier or the developing roller increases. Insufficient reverse chargeable toner increases, background stains occur, and image quality deteriorates.

Further, the particle size distribution represented by a value (Dv / Dp) obtained by dividing the volume average particle size (Dv) of the toner by the number-based number average particle size (Dp) obtained from the number distribution is 1.05-1. The range is preferably 25.
By sharpening the particle size distribution, the toner charge amount distribution becomes uniform and background fogging can be reduced. When Dv / Dp exceeds 1.25, the toner charge amount distribution becomes wide, and it becomes difficult to obtain a high-quality image.
The particle diameter of the toner shown here is selected using an aperture having a measurement hole size of 50 μm corresponding to the particle diameter of the toner to be measured using a Coulter Counter Multisizer (manufactured by Coulter). It is obtained by measuring the average particle size of 1,000 particles.

  As the resin used in the present invention, any normal toner resin such as styrene acrylic resin, polyol resin, and polyester resin can be applied. However, full color image reproduction is particularly possible from the viewpoint of fixability. For this, a polyester resin is suitable.

As polyester resins, functional groups contained in acid and alcohol monomer units and bonding groups other than ester bonds exist in the polyester resin, or resin components having different configurations exist in the polyester resin through covalent bonds, ionic bonds, etc. A modified polyester resin in a bonded state is preferred.
For example, the polyester terminal is reacted with something other than an ester bond. Specifically, a functional group such as an isocyanate group that reacts with an acid group or a hydroxyl group is introduced at the terminal and further reacted with an active hydrogen compound to modify or extend the terminal.
Further, compounds having a plurality of active hydrogen groups include those in which polyester ends are bonded to each other (urea-modified polyester, urethane-modified polyester, etc.).
In addition, a reactive group such as a double bond is introduced into the polyester main chain, radical polymerization is caused therefrom, and a carbon-carbon bond graft component is introduced into the side chain or the double bonds are bridged. Included (styrene modified, acrylic modified polyester, etc.).
In addition, a resin component having a different structure is copolymerized in the polyester main chain or reacted with a terminal carboxyl group or hydroxyl group. For example, those obtained by copolymerization with a silicone resin having a terminal modified with a carboxyl group, a hydroxyl group, an epoxy group, or a mercapto group (such as a silicone-modified polyester) are also included.
Examples of the urea-modified polyester resin (i) include a reaction product of a polyester prepolymer (A) having an isocyanate group and amines (B). Examples of the polyester prepolymer (A) having an isocyanate group include a polycondensate of a polyol (1) and a polycarboxylic acid (2) and a polyester having an active hydrogen group further reacted with a polyisocyanate (3). Can be mentioned.
Examples of the active hydrogen group possessed by the polyester include hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), amino groups, carboxyl groups, mercapto groups, and the like. Among these, alcoholic hydroxyl groups are preferred.

Examples of the polyol (1) include a diol (1-1) and a tri- or higher valent polyol (1-2). (1-1) alone or (1-1) and a small amount of (1-2) Mixtures are preferred. Diol (1-1) includes 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 alicyclic diol; bisphenol And alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, 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 polyol (1-2) 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 polycarboxylic acid (2) include dicarboxylic acid (2-1) and trivalent or higher polycarboxylic acid (2-2). (2-1) alone and (2-1) with a small amount of ( The mixture of 2-2) is preferred. Dicarboxylic acid (2-1) includes alkylene dicarboxylic acid (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acid (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acid (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 polycarboxylic acid (2-2) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (trimellitic acid, pyromellitic acid, and the like). In addition, as polycarboxylic acid (2), you may make it react with polyol (1) using the acid anhydride or lower alkyl ester (methyl ester, ethyl ester, isopropyl ester, etc.) of the above-mentioned thing.

  The ratio of the polyol (1) to the polycarboxylic acid (2) is usually 2/1 to 1/1, preferably 1. as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. 5/1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.

  Examples of the polyisocyanate (3) 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.); isocyanurates; polyisocyanates such as phenol derivatives, oximes, caprolactams And a combination of two or more of these.

The ratio of the polyisocyanate (3) is usually 5/1 to 1/1, preferably 4 /, as the equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. 1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. On the other hand, if the molar ratio of [NCO] is less than 1, the urea content in the modified polyester tends to be low, and the hot offset resistance tends to deteriorate.
The content of the polyisocyanate (3) component in the prepolymer (A) having an isocyanate group at the terminal is usually 0.5 to 40% by weight, preferably 1 to 30% by weight, more preferably 2 to 20% by weight. It is. If it is less than 0.5% by weight, 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% by weight, the low-temperature fixability tends to deteriorate.

The number of isocyanate groups contained per molecule in the prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2.5 on average. It is. 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.
As amines (B), diamine (B1), triamine or higher polyamine (B2), amino alcohol (B3), amino mercaptan (B4), amino acid (B5), and amino groups of (B1) to (B5) (B6) etc. that are blocked. Examples of the diamine (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′dimethyldicyclohexylmethane, diaminecyclohexane, Isophorone diamine etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine etc.) and the like.
Examples of the trivalent or higher polyamine (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), Examples include oxazoline compounds.
Among these amines (B), preferred are (B1) and a mixture of (B1) and a small amount of (B2).
Furthermore, if necessary, the molecular weight of the urea-modified polyester can be adjusted by using an elongation terminator. Examples of the elongation terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).

The ratio of amines (B) is the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). The ratio 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] exceeds 2 or less than 1/2, the molecular weight of the urea-modified polyester (i) tends to be low, and the hot offset resistance tends to deteriorate.
In the present invention, the urea-modified polyester (i) 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 tends to deteriorate.

The urea-modified polyester (i) of the present invention is produced by a one-shot method or a prepolymer method. The weight average molecular weight of the urea-modified polyester (i) is usually 10,000 or more, preferably 20,000 to 10,000,000, more preferably 30,000 to 1,000,000.
If it is less than 10,000, the hot offset resistance tends to deteriorate. The number average molecular weight of the urea-modified polyester 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. (I) When used alone, the number average molecular weight is usually 20000 or less, preferably 1000 to 10000, and more preferably 2000 to 8000. When it exceeds 20000, the low-temperature fixability and the gloss when used in a full-color device tend to deteriorate.

In the present invention, not only the urea-modified polyester (i) is used alone, but also the unmodified polyester (ii) can be contained as a toner binder component together with the (i). By using (ii) in combination, the low-temperature fixability and glossiness when used in a full-color apparatus are improved, which is preferable to single use.
Examples of (ii) include the same polycondensates of polyol (1) and polycarboxylic acid (2) as in the polyester component (i) above, 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, for example, may be modified with a urethane bond.
It is preferable that (i) and (ii) are at least partially compatible with each other 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) and (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 tends to deteriorate, and it tends to be disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.
The peak molecular weight of (ii) is usually 1000-30000, preferably 1500-10000, more preferably 2000-8000. If it is less than 1000, the heat resistant storage stability is deteriorated, and if it exceeds 10,000, the low-temperature fixability tends to be deteriorated.
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 tends to be disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. The acid value of (ii) is usually 1-30, preferably 5-20. By having an acid value, it tends to be negatively charged.

In the present invention, the glass transition point (Tg) of these resins serving as a toner binder is usually 50 to 70 ° C., preferably 55 to 65 ° C. If it is less than 50 ° C., the heat resistant storage stability of the toner is deteriorated, and if it exceeds 70 ° C., the low-temperature fixability tends to be insufficient.
Due to the coexistence of the urea-modified polyester resin, the dry toner of the present invention tends to have good heat-resistant storage stability even when the glass transition point is low, as compared with known polyester-based toners.
As the storage elastic modulus of the toner binder, the temperature (TG ′) at which 10000 dyne / cm ² is obtained at a measurement frequency of 20 Hz is usually 100 ° C. or higher, preferably 110 to 200 ° C. If it is less than 100 ° C., the hot offset resistance tends to deteriorate. As the viscosity of the toner binder, the temperature (Tη) at 1000 poise at a measurement frequency of 20 Hz is usually 180 ° C. or lower, preferably 90 to 160 ° C. If it exceeds 180 ° C., the low-temperature fixability tends to deteriorate.
That is, TG ′ is preferably higher than Tη from the viewpoint of achieving both low temperature fixability and hot offset resistance. In other words, the difference between TG ′ and Tη (TG′−Tη) is preferably 0 ° C. or higher. More preferably, it is 10 degreeC or more, Most preferably, it is 20 degreeC or more. The upper limit of the difference is not particularly limited.
Further, from the viewpoint of achieving both heat-resistant storage stability and low-temperature fixability, the difference between Tη and Tg is preferably 0 to 100 ° C. More preferably, it is 10-90 degreeC, Most preferably, it is 20-80 degreeC.

As the coloring agent of the present invention, known dyes and pigments can be used, such as 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, Fayce Red, Parachlor Ortoni Roaniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine B, 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, Tolujing Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake , Thioindigo red B, thioindigo maroon, oil red, quinacridone red, pyrazolone , Polyazo Red, Chrome Vermillion, 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, Chrome Oxide, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Fu Mention may be made of talocyanine green, anthraquinone green, titanium oxide, zinc white, litbon and the like and mixtures thereof.
The content of the colorant is usually 1 to 15% by weight, preferably 3 to 10% by weight, based on the toner.

The colorant used in the present invention can also be used as a master batch combined with a resin.
Examples of binder resins that can be used for the production of the master batch or kneaded with the master batch include those that can be used in addition to the modified and unmodified polyester resins listed above.
That is, a polymer of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyltoluene and the like; a styrene-p-chlorostyrene copolymer, a styrene-propylene copolymer, a styrene-vinyltoluene copolymer, a styrene- Vinyl naphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer , Styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene Copolymer, styrene-a Styrene copolymers such as polyene methacrylate, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, Polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic or alicyclic hydrocarbon resin, aromatic Base petroleum resin, chlorinated paraffin, paraffin wax and the like can be mentioned, and these can be used alone or in combination.

The masterbatch used in the present invention can be obtained by mixing and kneading the masterbatch resin and the colorant under high shearing force. At this time, an organic solvent can be used in order to enhance the interaction between the colorant and the resin.
There is also a method called so-called flushing method in which an aqueous paste containing water of a colorant is mixed and kneaded together with a resin and an organic solvent, the colorant is transferred to the resin side, and moisture and organic solvent components are removed. Since the wet cake of the agent can be used as it is, it does not need to be dried and is preferably used.
For mixing and kneading, a high shearing dispersion device such as a three-roll mill is preferably used.

Further, a wax may be contained as a release agent together with the toner binder and the colorant.
As the wax in the present invention, known ones can be used, for example, polyolefin wax (polyethylene wax, polypropylene wax, etc.); long chain hydrocarbon (paraffin wax, sasol wax, etc.); carbonyl group-containing wax, etc. Can be mentioned.
Of these, carbonyl group-containing waxes are preferred.
Carbonyl group-containing waxes include polyalkanoic acid esters (carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18. -Octadecandiol diol distearate, etc.); polyalkanol esters (tristearyl trimellitic acid, distearyl maleate, etc.); polyalkanoic acid amides (ethylenediamine dibehenyl amide, etc.); polyalkylamides (trimellitic acid tristearyl amide, etc.) And dialkyl ketones (such as distearyl ketone). Among these carbonyl group-containing waxes, polyalkanoic acid esters are preferred.
The melting point of the wax of the present invention is usually 40 to 160 ° C, preferably 50 to 120 ° C, more preferably 60 to 90 ° C.
A wax having a melting point of less than 40 ° C. has an adverse effect on heat-resistant storage stability, and a wax having a melting point of more than 160 ° C. tends to cause a cold offset when fixing at a low temperature.
Further, the melt viscosity of the wax is preferably 5 to 1000 cps, more preferably 10 to 100 cps as a measured value at a temperature 20 ° C. higher than the melting point. Waxes exceeding 1000 cps have poor effects for improving hot offset resistance and low-temperature fixability.
The content of the wax in the toner is usually 0 to 40% by weight, preferably 3 to 30% by weight.

The toner of the present invention may contain a charge control agent as necessary.
Known charge control agents can be used, such as nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified 4 Secondary ammonium salts or compounds, tungsten simple substances or compounds, fluorine activators, salicylic acid metal salts, and metal salts of salicylic acid derivatives.
Specifically, Bontron 03 of nigrosine dye, Bontron P-51 of quaternary ammonium salt, Bontron S-34 of metal-containing azo dye, E-82 of oxynaphthoic acid metal complex, E of salicylic acid metal complex -84, phenolic condensate E-89 (above, Orient Chemical Industries), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, Hodogaya Chemical Co., Ltd.), quaternary Copy charge PSY VP 2038 of ammonium salt, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR which is a boron complex 147 (manufactured by Nippon Carlit), copper phthalocyanine, perylene, quinaclide , Azo pigments, sulfonate group, carboxyl group, and polymer compounds having a functional group such as a quaternary ammonium salt.

In the present invention, the amount of charge control agent used is determined uniquely 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 uniquely limited. However, it is preferably 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 main charge control agent is reduced, the electrostatic attractive force with the developing roller is increased, the flowability of the developer is reduced, and the image density is reduced. Incurs a decline.
These charge control agents and mold release agents can be melt-kneaded together with the master batch and the resin, and of course, they may be added when dissolved and dispersed in an organic solvent.

  These resins, colorants, and charge control agents added as necessary are mixed and dispersed. In this mixing and dispersing, the contents are sufficiently uniformly dispersed, such as a mixer using ordinary stirring, more preferably a homogenizer having a high-speed rotating body and a stator, a high-pressure homogenizer, and a dispersing machine using a media such as a ball mill, a bead mill, and a sand mill. Suitable equipment.

  The aqueous medium used in the present invention may be water alone, or a solvent miscible with water may be used in combination. Examples of the miscible solvent include alcohol (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methylcellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.) and the like.

The method for producing a toner for electrophotography using the continuous emulsification method of the present invention uses an emulsifier to create emulsified droplets of a uniform dispersion of these resins, colorants and the like in an aqueous medium to obtain an emulsion. . The emulsification method is not particularly limited, and known equipment such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, and an ultrasonic wave can be applied.
In order to make the particle size of the dispersion 2 to 20 μm, a high-speed shearing type is preferable.
The emulsifier having rotating blades is not particularly limited, and any emulsifier and disperser that are generally commercially available can be used.
For example, Ultra Thalax (manufactured by IKA), Polytron (manufactured by Kinematica), TK auto homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), Ebara Milder (manufactured by Ebara Corporation), TK pipeline homomixer , TK homomic line flow (manufactured by Special Machine Industries Co., Ltd.), colloid mill (manufactured by Shinko Pantech Co., Ltd.), slasher, trigonal wet pulverizer (manufactured by Mitsui Miike Chemical Co., Ltd.) ), Fine flow mill (manufactured by Taiheiyo Kiko Co., Ltd.) and other continuous emulsifiers, CLEARMIX (manufactured by MTechnic Co., Ltd.), fill mix (manufactured by Koki Kogyo Co., Ltd.) Etc.

When a high-speed shearing disperser is used, the number of rotations is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm.
The emulsification time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. As temperature at the time of emulsification, it is 0-150 degreeC (under pressurization) normally, Preferably it is 10-98 degreeC.
Higher temperatures are preferred in that the uniform dispersion of resin, colorant, etc. has a low viscosity and is easily emulsified.
Within the uniform dispersion of the resin, colorant, etc., the resin elongates or undergoes a crosslinking reaction to become a toner binder.

An example of the polymerization reaction of the toner binder will be described.
The prepolymer (A) and the amines (B) react in a uniform dispersion such as a resin or a colorant to obtain a polyester modified with a urea bond serving as a toner binder.
Prepolymer (A) refers to polyol (1) and polycarboxylic acid (2) heated to 150-280 ° C. in the presence of a known esterification catalyst such as tetrabutoxytitanate, dibutyltin oxide, etc. It has an isocyanate group obtained by reacting a polyisocyanate (3) at 4, 0 to 140 ° C. with a polyester having a hydroxyl group obtained by distilling off generated water.
When the polyisocyanate (3) is reacted and when the prepolymer (A) and the amines (B) are reacted, a solvent can be used as necessary.
Usable solvents include aromatic solvents (toluene, xylene, etc.); ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.); esters (ethyl acetate, etc.); amides (dimethylformamide, dimethylacetamide, etc.) and ethers And those inert to the isocyanate (3), such as tetrahydrofuran (such as tetrahydrofuran). When polyester (ii) not modified with urea bond is used in combination, (ii) is produced by the same method as polyester having a hydroxyl group, and this is dissolved in the solution after completion of the reaction of (i) and mixed. To do.

The elongation or crosslinking reaction time is selected depending on the reactivity depending on the combination of the isocyanate group structure of the prepolymer (A) and the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 24 hours.
The reaction temperature is generally 0 to 150 ° C, preferably 40 to 98 ° C.
Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.

Further, a volatile solvent in which the modified polyesters (i) and (A) are soluble is used in order to lower the viscosity of the oil phase of the toner composition and enable emulsification. The solvent is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal.
Examples of the solvent include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, Methyl ethyl ketone, methyl isobutyl ketone and the like can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform, and carbon tetrachloride are preferable.
In addition, the toner shape can be further adjusted by using a solvent that can be dissolved in an aqueous medium such as alcohol or water.
The amount of solvent used with respect to 100 parts of the toner composition is usually 10 to 900 parts.

The emulsified droplets serving as toner particles are obtained by, for example, dispersing a dispersion composed of a prepolymer (A) having an isocyanate group as described above and a toner composition such as other resins and colorants in an aqueous medium, with amines (B). The modified polyester (i) produced in advance may be used.
A dispersant may be used in order to stabilize the emulsified droplets in the aqueous medium. Various types of dispersants can be used. Hereinafter, the kind of the dispersing agent will be described.

The solid fine particle dispersant is present in a solid form hardly soluble in water in an aqueous medium, and is preferably fine particles having an average particle diameter of 0.01 to 1 μm.
Specific examples of the inorganic solid fine particle dispersant include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, silica sand, clay, mica, silica Examples include apatite, diatomaceous earth, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride.
More preferably, tricalcium phosphate, calcium carbonate, colloidal titanium oxide, colloidal silica, hydroxyapatite and the like can also be used. In particular, hydroxyapatite synthesized by reacting sodium phosphate and calcium chloride in water under a basic condition is preferable.

The organic solid fine particle dispersant is copolymerized with a monomer having a carboxyl group such as methacrylic acid obtained by microcrystals of low molecular weight organic compounds or polymer fine particles such as soap-free emulsion polymerization, suspension polymerization or dispersion polymerization. Examples include polystyrene, methacrylic acid ester, acrylic acid ester copolymer, polycondensation systems such as silicone, benzoguanamine, and nylon, and polymer particles made of thermosetting resin.
After adjusting the solid fine particle dispersant in water, an inorganic substance that can be dissolved in an acid such as tricalcium phosphate is partially dissolved by adding a necessary amount of hydrochloric acid or the like in advance. The addition amount of the acid is preferably 0.01% to 10%, more preferably 0.1% to 5% of the amount capable of completely dissolving the inorganic substance.

  In the case where a polymer fine particle copolymerized with (meth) acrylic acid having a carboxyl group is used, a necessary amount of a base such as sodium hydroxide is added and partially dissolved. The amount of alkali added is preferably 0.01% to 10%, more preferably 0.1% to 5% of the amount capable of completely dissolving the inorganic substance.

  In addition, as a dispersant to be used together or after emulsion polymerization, alkylbenzene sulfonate, α-olefin sulfonate, phosphate anion surfactants such as phosphate ester, alkylamine salt, amino alcohol fatty acid derivative, polyamine fatty acid derivative, Cationic surfactants of amine salt type such as imidazoline, and quaternary ammonium salt type such as alkyltrimethylammonium salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, pyridinium salt, alkylisoquinolinium salt, benzethonium chloride , Nonionic surfactants such as fatty acid amide derivatives and polyhydric alcohol derivatives such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl-N, N-dimethylammonium Base amphoteric surfactants such as tines and the like.

Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount.
Preferred anionic surfactants having a fluoroalkyl group include fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [omega-fluoroalkyl (C6-C11). ) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [omega-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carvone Acids and metal salts, perfluoroalkyl carboxylic acids (C7 to C13) and their metal salts, perfluoroalkyl (C4 to C12) sulfonic acids and their metal salts, perfluorooctane sulfonic acid diethanolamide, N-propyl-N -(2 hydroxyethyl) -Fluorooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. Is mentioned.

  Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101. DS-102 (manufactured by Taikin Kogyo Co., Ltd.), Mega-Fac F-ll0, F-120, F-113, F-191, F-812, F-833 (Dainippon Ink Co., Ltd.), Xtop EF- 102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fagento F-100, F150 (manufactured by Neos).

  In addition, as the cationic surfactant, aliphatic quaternary ammonium salts such as aliphatic primary, secondary or secondary amic acid, perfluoroalkyl (C6 to C10) sulfonamidopropyltrimethylammonium salt which right the fluoroalkyl group, Benzalkonium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (Asahi Glass), Florard FC-135 (Sumitomo 3M), Unidyne DS-202 (Daikin Industries) ), Megafuck F-150, F-824 (Dainippon Ink Co., Ltd.), Xtop EF-132 (Tochem Products Co., Ltd.), Footgent F-300 (Neos Co., Ltd.), and the like.

The stabilization of the dispersed droplets may be adjusted with a polymer protective colloid.
For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride, or other (meth) acrylic simple substances containing hydroxyl groups Such as β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, γ-hydroxypropyl acrylate, γ-hydroxypropyl methacrylate, acrylic acid 3 -Chloro 2-hydroxypropyl, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate, N-methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, or esters of compounds containing vinyl alcohol and a carboxyl group Such as vinyl acetate, vinyl propionate, vinyl butyrate, acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, pinylviridine, vinylpyrrolidone, vinylimidazole, ethylene Homopolymers or copolymers such as those having a nitrogen atom such as imine or a heterocyclic ring thereof, polyoxyethylene, polyoxypropylene, Reoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxyethylene nonyl Polyoxyethylenes such as phenyl esters, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.

  When a dispersant is used, the dispersant can remain on the surface of the toner particles. However, after the elongation and / or cross-linking reaction, it is better to dissolve and wash away the remaining solid fine particle dispersant. From the aspect, it is preferable.

Toner particles are produced by such emulsification, but the resulting toner particles often have a wide particle size distribution width.
In the present invention, toner particles having a sharp particle size distribution are achieved by incorporating a classification function at the time of emulsification. Usually, a toner having a wide particle size distribution range is, for example, washed or dried after the emulsification step. After passing through such processes, wet or dry classification is performed so as to obtain a desired sharp particle size distribution.
At that time, a cyclone, a decanter, a centrifuge, an elbow jet or the like is used as a classifier.
The unnecessary fine particles or coarse particles obtained there may be returned to the kneading process and used for forming particles.
In the present invention, the unnecessary fine particles or coarse particles can be discharged and reused in a pre-process, that is, an emulsification process, so that unnecessary processing energy and labor can be saved.

After the toner particles are formed by emulsification or in addition to wet classification, a cleaning operation is performed to remove unnecessary substances such as the organic solvent and dispersant contained in the toner particle surface or inside the toner particles. Is done. It is preferable to use ion-exchanged water having low electrical conductivity for use as washing water. In addition, in order to wash away these unnecessary substances, acid or alkali may be mixed in the washing water.
Furthermore, after passing through a step of crushing the toner particles aggregated in the process into original fine particles, a step of removing the remaining coarse particles through a sieve.

By mixing the thus-dried toner powder together with external additives such as charge control fine particles, fluidizing agent fine particles, and cleaning improvers, and applying mechanical impact force to the mixed powder. Immobilize and fuse on the surface to make composite particles.
Specific means include a method of applying an impact force to the mixture by blades rotating at high speed, a method of injecting and accelerating the mixture in a high-speed air stream, and causing particles or composite particles to collide with an appropriate collision plate, etc. is there.
As equipment, Ong mill (manufactured by Hosokawa Micron Co., Ltd.), I-type mill (manufactured by Nippon Pneumatic Co., Ltd.) is modified to reduce the pulverization air pressure, hybridization system (manufactured by Nara Machinery Co., Ltd.), kryptron Examples include a system (manufactured by Kawasaki Heavy Industries, Ltd.) and an automatic mortar.

As the external additive, inorganic fine particles can be preferably used. The primary particle diameter of the inorganic fine particles is preferably 5 mμ to 2 μm, and particularly preferably 5 mμ to 500 mμ. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g.
The proportion of the inorganic fine particles used is preferably 0.01 to 5% by weight of the toner, and particularly preferably 0.01 to 2.0% by weight.
Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, quartz sand, clay, mica, wollastonite, diatomaceous earth. Examples include soil, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride.

  In addition, polymer fine particles, such as polystyrene obtained by soap-free emulsion polymerization, suspension polymerization, and dispersion polymerization, methacrylate esters, acrylate copolymers, polycondensation systems such as silicone, benzoguanamine, and nylon, thermosetting Examples thereof include polymer particles made of a resin.

Such a fluidizing agent performs surface treatment to increase hydrophobicity, and can prevent deterioration of flow characteristics and charging characteristics even under high humidity.
For example, silane coupling agents, silylating agents, silane coupling agents having a fluoroalkyl group, organic titanate coupling agents, aluminum coupling agents, silicone oils, modified silicone oils and the like are preferable surface treatment agents. .

Examples of the cleaning property improver for removing the developer after transfer remaining on the photoreceptor or the primary transfer medium include, for example, zinc stearate, calcium stearate, fatty acid metal salts such as stearic acid, such as polymethyl methacrylate fine particles, polystyrene fine particles, etc. And polymer fine particles produced by soap-free emulsion polymerization.
The fine polymer particles preferably have a relatively narrow particle size distribution and a Dv of 0.01 to 1 μm.

When the toner of the present invention is used for a two-component developer, it may be used by mixing with a magnetic carrier. The carrier to toner content ratio in the developer is 1 to 10 weights of toner with respect to 100 parts by weight of carrier. Part is preferred.
As the magnetic carrier, conventionally known ones such as iron powder, ferrite powder, magnetite powder, magnetic resin carrier having a particle diameter of about 20 to 200 μm can be used.
Examples of the coating material include amino resins such as urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, and epoxy resin.
Polyvinyl and polyvinylidene resins such as acrylic resins, polymethyl methacrylate resins, polyacrylonitrile resins, polyvinyl acetate resins, polyvinyl alcohol resins, polyvinyl butyral resins, polystyrene resins and styrene acrylic copolymer resins, Halogenated olefin resin such as vinyl chloride, polyester resin such as polyethylene terephthalate resin and polybutylene terephthalate resin, polycarbonate resin, polyethylene resin, polyvinyl fluoride resin, polyvinylidene fluoride resin, polytrifluoroethylene resin, polyhexa Fluoropropylene resin, copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene and vinylidene fluoride Fluoro such as terpolymers of emission and non-fluoride monomers including, and silicone resins.
Moreover, you may contain electrically conductive powder etc. in coating resin as needed. As the conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide or the like can be used. These conductive powders preferably have an average particle diameter of 1 μm or less. When the average particle diameter is larger than 1 μm, it becomes difficult to control electric resistance.

  The toner of the present invention can also be used as a one-component magnetic toner that does not use a carrier or a non-magnetic toner.

EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to this. Hereinafter, a part shows a weight part.
(Raw material adjustment)
In a reaction vessel in which a stir bar and a thermometer were set, 683 parts of water, 11 parts of sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30: manufactured by Sanyo Chemical Industries), 138 parts of styrene, 138 parts of methacrylic acid, 1 part of ammonium persulfate was charged and stirred at 400 rpm for 15 minutes to prepare a white emulsion. Next, the emulsion 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, and an aqueous dispersion of a vinyl resin (styrene-methacrylic acid-methacrylic acid etherene oxide adduct sulfate sodium salt copolymer) [ Fine particle dispersion].
Further, 83 parts of [fine particle dispersion] were mixed with 990 parts of water, 37 parts of a 48.5% aqueous solution of dodecyl diphenyl ether disulfonate (Eleminol MON-7): Sanyo Kasei Kogyo Co., Ltd., and 90 parts of ethyl acetate. A liquid was obtained.
This is referred to as [aqueous phase].
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 Add 2 parts of tin oxide, react at 230 ° C for 8 hours at normal pressure, and further react for 5 hours at 10-15 mmHg reduced pressure, then add 44 parts of trimellitic anhydride to the reaction vessel at 180 ° C at normal pressure. The mixture was reacted for 2 hours to obtain [Low molecular weight polyester].
In a reaction vessel equipped with a condenser, a stirrer, and a nitrogen introduction pipe, 682 parts of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, 22 parts of trimellitic anhydride And 2 parts of dibutyltin oxide were added, reacted at 230 ° C. for 8 hours at normal pressure, and further reacted for 5 hours at a reduced pressure of 10 to 15 mmHg to obtain an [intermediate polyester].
Next, 410 parts of [intermediate polyester], 89 parts of isophorone diisocyanate, and 500 parts of ethyl acetate were placed in a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe, and reacted at 100 ° C. for 5 hours. Phase].
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].
Add 1200 parts of water, 540 parts of carbon black (made by Printex35 Dexa) [DBP oil absorption = 42 ml / 100 mg, pH = 9.5], 1200 parts of polyester resin, and mix with a Henschel mixer (made by Mitsui Mining Co., Ltd.). After kneading at 150 ° C. for 30 minutes using two rolls, rolling and cooling and pulverizing with a pulverizer, a [masterbatch] was obtained.
A container equipped with a stir bar and a thermometer was charged with 378 parts of [low molecular polyester], 110 parts of Carnauba WAX, 22 parts of CCA (salicylic acid metal complex E-84: Orient Chemical Co., Ltd.), and 947 parts of ethyl acetate. The temperature was raised to 80 ° C. and maintained at 80 ° C. for 5 hours, and then cooled to 30 ° C. over 1 hour.
Next, 500 parts of [Masterbatch] and 500 parts of ethyl acetate were charged in a container and mixed for 1 hour to obtain [Raw material solution].
[Raw material solution] Transfer 1324 parts to a container and use a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.). Carbon black and WAX were dispersed under conditions of 3 passes.
Next, 1324 parts of a 65% ethyl acetate solution of [low molecular weight polyester] was added, and one pass was performed with a bead mill under the above conditions to obtain [Pigment / WAX Dispersion].
[Pigment / WAX dispersion] 664 parts and [ketimine compound] 5.9 parts are put in a container and mixed well with a disper to obtain [B oil phase].

(Used equipment / equipment)
Facilities and equipment used in performing the present invention, FIG. 1, a continuous emulsion equipment shown in the schematic diagram of FIG.
Moreover, the conventional continuous emulsification equipment used for the comparative example 1 of this invention is shown by the schematic of FIG.

First, a process in which a mixed liquid of [A oil phase], [B oil phase], and [aqueous phase] is sent into the continuous emulsification pipe, which is a common condition in the present example and the comparative example, will be described.
FIG. 1 shows a schematic view of a tube having helical protrusions incorporated in a continuous emulsification facility according to the present invention. At [A Oil Phase] of "001 [A Oil Phase] tank" in and "002 [B Oil Phase] for tank" of [B Oil Phase] are "004 feed pump (rotary pump)" It is sent to << 005 Static Mixer >>. The amount of liquid fed is adjusted so that [B oil phase] is 60.4 parts with respect to [A oil phase] 7.4 parts. Here, the mixture that is sufficiently mixed and uniform (referred to as [oil phase]) is combined with 101.6 parts of [water phase] sent from the << 003 [water phase] tank} and continuously emulsified. It is thrown into the circulation pipe.
Here, in FIG. 5, the joined [oil phase] and [aqueous phase] join with the slurry liquid already circulating at high speed in the continuous emulsification pipe, and << 007 emulsifier (pipeline homomixer) >> (T. K. Pipeline homomixer type 2SL, manufactured by Tokushu Kika Kogyo Co., Ltd.) and subjected to emulsification. At this time, a slurry liquid in which minute [oil phase] droplets are present in the [aqueous phase] medium is obtained.
This slurry liquid is discharged from the discharge port side of << 007 emulsifier (pipeline homomixer) >>. In this experiment, the number of rotations of << 007 emulsifier (pipeline homomixer) is 8400 rpm, and the amount of [A oil phase], [B oil phase], and [aqueous phase] fed is the above mixing ratio, The total was 1.0 kg / min. Moreover, the liquid temperature rise by the shear energy added to a liquid was suppressed with the cooler, and 23 degreeC was always maintained.

Immediately before << 007 emulsifier (pipeline homomixer) >> connected to the continuous emulsification pipe, in Fig. 1 a tube having a spiral protrusion is shown in Fig. 3 and a device for generating a {010 spiral flow (cyclone type) Device) >>, both of which are for applying centrifugal force to the particles in the emulsified slurry liquid as will be described later in the Examples.

Example 1
A continuous emulsification experiment was conducted using the facility (FIG. 1) in which a tube having spiral protrusions in a continuous emulsification mechanism was incorporated in the continuous emulsification facility according to the present invention.
The slurry liquid discharged from the discharge side of << 007 emulsifier (pipeline homomixer) circulates in the continuous emulsification circulation pipe. In this circulation pipe, << 009 spiral pipe >> is installed before << 007 emulsifier (pipeline homomixer) >>, and centrifugal force is applied to the circulating slurry liquid at this point. The applied centrifugal force is found to be 500 G as a result of calculation.
The slurry liquid that overflows from the continuous emulsification circulation pipe by the continuous addition of [oil phase] and [aqueous phase] is sequentially sent by pipe to the << 008 toner recovery tank >>.

(Example 2)
In Example 2, << 009 spiral pipe >> having a larger radius than that of Example 1 was used. Other equipment was the same as in Example 1, and the same experiment as in Example 1 was performed. By increasing the radius of << 009 spiral pipe >>, the centrifugal force applied to the circulating slurry liquid in Example 2 was 300G.

(Example 3)
In Example 3, << 009 spiral pipe >> is connected to the one in Example 1 in the reverse direction, so that the rotational direction given to the slurry liquid by << 009 spiral pipe >> and << 007 emulsifier (pipeline homomixer) The rotation direction of the rotating feathers of the Other equipment was the same as in Example 1, and the same experiment as in Example 1 was performed.

Example 4
In this Example 4, as shown in FIG. 3, immediately before << 007 emulsifier (pipeline homomixer) >> instead of << 009 spiral pipe >> to give a centrifugal effect to the particles in the emulsified slurry, A device for generating a 010 spiral flow (a cyclone type device) was installed. The discharge port of << 010 spiral flow generating device (cyclone type device) >> was connected to the continuous emulsification pipe, and a centrifugal effect of 500 G was imparted to the slurry liquid by the spiral flow from the discharge port. Other equipment was exactly the same as in Example 1, and the same experiment as in Example 1 was performed.

(Comparative Example 1)
In Comparative Example 1, an experiment was performed in a continuous emulsification process, which is normally performed as shown in FIG. The experiment was performed using the same equipment and the same conditions as in Example 1 except that there was no << 009 spiral pipe >> compared to FIG.

(Evaluation methods)
Dv and Dv / Dp of the particles contained in the slurry liquid in each << 008 toner recovery tank >> obtained by the above examples and comparative examples were measured. Dv and Dv / Dp of the particles were analyzed using Coulter Multisizer III (manufactured by Coulter), connected to a personal computer (manufactured by IBM), and analyzed using dedicated analysis software (manufactured by Coulter). The Kd value was set using standard particles of 10 μm, and the aperture current was set at an automatic setting. As the electrolytic solution, a 1% NaCl aqueous solution is prepared using primary sodium chloride.
In addition, ISOTON-II (manufactured by Coulter Scientific Japan) can be used. As a measuring method, 0.1 to 5 ml of a surfactant, preferably alkylbenzene sulfonate, is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution, and 2 to 20 mg of a measurement sample is further added. The electrolyte solution in which the sample is suspended is dispersed for about 1 to 3 minutes with an ultrasonic disperser, and the volume and number distribution of the toner particles of 2 μm or more are measured by 50,000 counts using a 100 μm aperture tube. And calculated.
Then, Dv and Dp according to the present invention were obtained. The closer the Dv / Dp is to 1.0, the sharper the particle size distribution.
Next, in order to evaluate the image characteristics using the sharp particle size distribution particles produced in the present invention as a toner, this mixed solution was transferred to a vessel equipped with a stir bar and a thermometer, 0.3 parts of sodium lauryl sulfate was added, and the room temperature was 30 minutes. Under stirring and dissolved.
Next, the solvent was removed under reduced pressure at 30 ° C. and 50 mmHg. Here, only the slurry liquid of Comparative Example 1 which is a conventional manufacturing method was subjected to wet classification using centrifugal force in accordance with the conventional manufacturing method, and fine particles were removed.
And after adding 120 parts of 35% concentrated hydrochloric acid to each of the slurry liquids of Examples 1, 2, 3, 4 and Comparative Example 1, the operation of separating by filtration, redispersing the obtained cake in distilled water and filtering. Washed repeatedly 3 times. Thereafter, it was dried under reduced pressure at 40 ° C. for 24 hours to obtain particles.
To 100 parts of the obtained particles, 0.7 part of hydrophobic silica and 0.3 part of hydrophobic titanium oxide were added and mixed with a Henschel mixer. A developer comprising 5 parts of the toner subjected to the external additive treatment and 95 parts of a copper-zinc ferrite carrier coated with a silicone resin and having an average particle diameter of 40 μm was prepared.

The charge amount is adjusted to an absolute value of about 15 to 25 (μc / g) in order to obtain sufficient developability of the toner and to prevent background staining due to the reversely charged toner. A developer was created.
The fine line reproducibility, an image characteristic item evaluated this time, is obtained by putting this developer into a remodeling machine from which a fixing oil portion of an intermediate transfer type commercial color copying machine (IMAGIO COLOR 5000; manufactured by Ricoh) is removed, and an image occupancy rate of 7 The running was carried out using 6000 paper manufactured by Ricoh with a printing rate of%.
Compare the original 10th image and the 30,000th image thin line with the original, zoom in with an optical microscope at a magnification of 100x, and evaluate the line omission in 5 stages while comparing it with the stage sample. did. In either case, the image quality is high in the order of ◎>○>●>△> ×. In particular, the evaluation of x is a level that cannot be adopted as a product. The results are shown in Table 1.

As can be seen from Table 1, Examples 1, 2, 3, and 4 in which the spiral pipe and cyclone type apparatus, which is a feature of the present invention, are incorporated in the emulsification process and the centrifugal effect is applied to the particles are ordinary emulsifications without a spiral pipe. Compared to the step (Comparative Example 1), it can be seen that the value of Dv / Dp immediately after emulsification and when the toner is completed is closer to 1.0 and the particle size distribution is sharp.
In addition, by applying a centrifugal effect to the particles, a large shearing force is applied to the coarse particles, and the Dv immediately after emulsification and at the completion of the toner is also reduced. Comparing Example 1 and Example 2 incorporating spiral piping, Dv is smaller and Dv / Dp is smaller when the applied centrifugal force is 500 G than when it is 300 G, and 500 G is caused by particles. As a result of giving a large centrifugal effect, it can be seen that the particle size distribution is sharp.
The result of the image evaluation was proportional to the degree of spread of the particle size distribution, and the best result was obtained when the applied centrifugal force was 500G. In Example 1 and Example 4 using a spiral pipe and a cyclone type device as means for applying an applied centrifugal force of 500 G, there is no significant difference in Dv and Dv / Dn at the time of toner completion immediately after emulsification.
Further, by making the liquid rotation direction with respect to the rotating blades reverse (Example 3), a larger shearing force is applied to the slurry liquid than in Example 1, and the volume average particle size is smaller than in Example 1. .

1 is a schematic view of a tube having spiral protrusions according to the present invention incorporated in a continuous emulsification facility. It is the inside schematic diagram which cut | disconnected partially the pipe | tube with a helical protrusion used for this invention. It is the schematic which integrated the mechanism (equipment of a cyclone type) which produces a spiral flow in piping according to the present invention in the continuous emulsification equipment. It is the schematic of the apparatus of the cyclone type used for this invention. It is the schematic of the conventional continuous emulsification equipment which does not incorporate the pipe | tube with a helical processus | protrusion. It is the schematic of the emulsifier provided with the axial flow flow generation mechanism.

Explanation of symbols

001 [A oil phase] tank 002 [B oil phase] tank 003 [water phase] tank 004 Liquid feed pump (rotary pump)
005 Static mixer 006 Cooler 007 Emulsifier (pipeline homomixer)
008 Toner recovery tank 009 Piping with spiral protrusion (spiral piping)
010 Device for generating spiral flow (Cyclone type device)

Claims (16)

An electrophotographic toner production method comprising a step of dissolving or dispersing a toner composition containing at least a resin and a colorant in an organic solvent, and continuously emulsifying the dissolved or dispersed material in an aqueous medium. The step includes a step of applying a centrifugal force to the emulsion containing the lysate or dispersion and an aqueous medium, a step of applying a shearing force to the emulsion, and the step of applying a centrifugal force to the emulsion includes the steps described above. The emulsion is spirally flown along the inner wall of the pipe to give centrifugal force to the emulsion. The small particles are gathered near the center of the pipe , the small particles are coalesced, and the emulsion is sheared. A method for producing an electrophotographic toner, wherein the toner is sent to a step of giving . 2. The method for producing an electrophotographic toner according to claim 1, wherein the centrifugal force applied to the particles in the emulsion is 500 G or more. 3. The emulsion according to claim 1, wherein by applying a centrifugal force, the emulsified liquid in the pipe is caused to flow so as to form a distribution in which the proportion of fine particles increases from the pipe wall toward the pipe center. A method for producing toner for electrophotography. Rotation after the step of providing the centrifugal force, using the pipe mechanism having a rotating portion to generate axial flow (referred to as axial flow stream generating mechanism) is installed to provide a shearing force, occurring due to the rotation of the rotating part Due to the difference in peripheral speed that is greater near the outer periphery of the rotating part than the vicinity of the axis, a large shear force is applied to the emulsified liquid flowing into the vicinity of the rotating part axis, resulting in larger particles 4. The method for producing an electrophotographic toner according to claim 1, further comprising a step of reducing the particle size to a predetermined particle size. The rotation direction of the flow of the emulsion liquid to which the centrifugal force is applied by the step of applying the centrifugal force is set to be opposite to the rotation direction of the rotating portion of the axial flow generation mechanism. A process for producing the electrophotographic toner according to claim 1. 6. The method for producing an electrophotographic toner according to any one of claims 1 to 5, wherein after the emulsification step, the particles in the liquid are taken out and the steps of washing, drying and classification are sequentially performed. An electrophotographic toner produced by the production method according to claim 1. The electrophotographic toner according to claim 7, wherein a volume-based volume average particle diameter (Dv) obtained from the volume distribution is 3 to 10 μm. The value (Dv / Dp) obtained by dividing the volume average particle diameter (Dv) by the number average particle diameter (Dp) obtained from the number distribution is 1.05 to 1.25. Or the electrophotographic toner according to 8. At least a resin, a toner composition comprising a colorant dissolved or dispersed in an organic solvent, a dissolution or dispersion an apparatus for producing a toner for electrophotography which continuous emulsion in an aqueous medium, the continuous emulsifying means, said Means for imparting centrifugal force to an emulsion containing a dissolved or dispersed material and an aqueous medium, means for imparting shear force to the emulsion, and means for imparting centrifugal force to the emulsion include piping the emulsion Spirally flow along the inner wall to give centrifugal force to the emulsified liquid, gather small particles near the center of the pipe, coalesce the small particles , and send to the means to give shear force to the emulsified liquid electrophotographic toner manufacturing apparatus, characterized in that. Claims the pipe to provide a centrifugal force to the emulsion are those one lifting spiral Jo突 cause the inner wall, and characterized in that incorporated in the part or all of the piping in the continuous emulsification device to the pipe Item 11. The electrophotographic toner production apparatus according to Item 10. The electrophotographic toner manufacturing apparatus according to claim 10 or 11, wherein a mechanism for generating a spiral flow in the pipe is incorporated in the emulsifying apparatus. 11. A mechanism (referred to as an axial flow generation mechanism) having a rotating part that generates an axial flow that applies a shearing force is disposed after the position where the mechanism that applies a centrifugal force is provided. The electrophotographic toner manufacturing apparatus according to any one of Items 12 to 12. 14. The electrophotographic toner production apparatus according to claim 13, wherein the axial flow generation mechanism is a pipeline homomixer. An image forming apparatus, wherein the developing unit contains the electrophotographic toner according to claim 7. An image forming method using the electrophotographic toner according to claim 7.

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