JP4134855B2 - Toner manufacturing method - Google Patents

Description

  The present invention relates to a toner manufacturing method, and more particularly to a toner manufacturing method for manufacturing a toner by performing solid-liquid separation of a toner particle dispersion using a filter having a mesh formed by arranging linear members.

  In recent years, toners that have been wet-granulated instead of toners produced by mechanical grinding are attracting attention because they are advantageous for reducing particle size, sharpening particle size distribution, and introducing a large amount of release agent. . Specific examples of a method for producing a toner that is granulated by a wet method include an emulsion association method, a suspension polymerization method, a dispersion polymerization method, and a solution suspension method using separately polycondensed polyester.

  Polymerized toner by the emulsion association method in which toner particles are formed through a polymerization process in an aqueous medium can control the particle size and shape of the toner particles in the manufacturing process, so that the particle size distribution is small and the particle size distribution is sharp. As a result, a toner having a rounded shape with no corners on the particle surface in which the shapes of the individual toner particles are uniform can be obtained (see, for example, Patent Document 1).

  Since high-resolution images are expected for toners of this size and shape, for example, a minute dot image of 1200 dpi (dpi represents the number of dots per inch (2.54 cm)) is formed. Considerations for adoption of digital image forming are increasing.

  The wet granulated toner is formed by forming toner particles in an aqueous medium or an organic solvent to form a toner particle dispersion, and then using a separation means represented by a solid-liquid separation device such as a filtration device. It is obtained by separating the toner particles from the particle dispersion and then adding an external additive as necessary. The dispersion liquid in which the toner particles are dispersed contains impurities such as surfactant, free release agent particles detached from the toner particles, or decomposed particles thereof. Therefore, when separating the toner particles from the dispersion liquid, it is necessary to clean the toner particles so that these impurities do not remain.

  Technology for cleaning toner particles by supplying washing water until the electrical conductivity of the filtrate falls below a specific value while separating solid particles and aqueous medium by centrifugation for the purpose of removing impurities from toner particles Is disclosed (for example, see Patent Document 2).

  Further, a technique is disclosed in which a cleaning liquid is added to a toner particle from which an aqueous medium has been removed in a container equipped with a stirring blade and a filter and stirred, and then the toner particle is filtered under pressure to remove impurities ( For example, see Patent Document 3.)

  However, it is not possible to completely remove impurities such as surfactants, salts, free release agent particles released from the toner particles, or decomposed particles thereof even if the usual cleaning action is repeated.

  In fact, when image formation is performed using toner obtained through the cleaning method disclosed in the above-mentioned patent document, a problem called toner blister occurs in which a white granular image defect occurs in a high density portion on the image. This is presumed that impurities remaining in the toner particles are hydrated and discharged as water vapor by heating in the fixing process, and as a result of destroying the toner layer when discharged in the form of bubbles, image defects are generated.

  Thus, a technique for cleaning toner particles while completely removing impurities from toner particles by a known solid-liquid separation means has not been established.

In addition, the solid-liquid separation of a small amount of toner particle dispersion causes the filter to become clogged. Therefore, it is necessary to replace the filter with a new filter each time the filter is clogged. It was difficult to carry out solid-liquid separation of liquid quickly and efficiently at low cost.
JP 2000-214629 A JP 2000-292976 A JP 2001-249490 A

  The present invention has been proposed in view of the above problems, and an object of the present invention is to provide a toner manufacturing method for manufacturing a toner capable of forming a stable image without causing an image defect on the toner image. And

The object of the present invention is achieved by adopting the following configuration.
(Claim 1)
In a toner manufacturing method including a step of solid-liquid separating a toner particle dispersion containing toner particles formed in an aqueous medium or an organic solvent using a filter, the filter has a mesh, And the linear members constituting the other one are arranged in close contact with each other, and when the toner particle dispersion is put into the filter, A method for producing a toner, comprising forming a solid-liquid separation surface made of toner particles in a mesh and performing solid-liquid separation.
(Claim 2)
In the mesh, the linear members constituting the one side are arranged at intervals of 12 to 240 lines / cm, and the linear members constituting the other side are arranged in close contact with 130 to 3000 lines / cm. The toner manufacturing method according to claim 1, wherein the toner is formed.
(Claim 3)
3. A toner manufacturing method, wherein the toner particle dispersion is once concentrated by a solid-liquid separation operation, and then the dispersion dispersed again in an aqueous medium is subjected to solid-liquid separation by the method according to claim 1 or 2.

  The toner manufacturing method of the present invention makes it possible to form a stable toner image without causing image defects due to toner blisters by sufficiently removing impurities from the surface of the toner particles. There is an excellent effect.

  In the configuration of the first aspect, a linear member constituting one side is arranged with a space therebetween, and a filter having a mesh in which a linear member constituting another one is arranged in close contact (hereinafter referred to as a book) The toner particle dispersion is subjected to solid-liquid separation using a filter according to the invention. Then, it has been found that when an image is formed using toner obtained through such a manufacturing method, a good toner image without causing image defects due to toner blisters can be obtained.

  Here, terms used in the above configuration will be described.

  The “toner particle dispersion liquid” as used in the present invention refers to a liquid obtained by dispersing toner particles that have undergone particle formation in a toner manufacturing process.

  The “mesh” referred to in the present invention constitutes the filter according to the present invention, and is formed by combining or weaving metal or resin linear members. That is, the filter according to the present invention has a tatami weave structure as described later by alternately weaving linear members. Then, mesh eyes are formed in regions surrounded by linear members woven alternately.

  In the present invention, one of the linear members is arranged at intervals, and the other one is arranged so as to be in close contact with each other to constitute a filter. Here, “one” means a state in which linear members are arranged in an arbitrary direction, and “another one” means a linear shape so as to be substantially orthogonal to the linear members arranged in the above-mentioned one. The state in which the members are arranged. Then, mesh eyes (hereinafter also referred to as pores) are formed in a region surrounded by the linear member constituting one and the linear member constituting the other.

  In the present invention, “solid-liquid separation” refers to separating liquid particles from the toner particle dispersion to separate the toner particles, and separating the water-containing toner particles into a toner lump of a predetermined shape called a toner cake ( An operation for forming a bulk product.

  The “solid-liquid separation surface” referred to in the present invention is a surface from which liquid components are removed from the toner particle dispersion, and as described above, in the present invention, the toner particles form a filled state in the mesh eye, A “surface” is formed by supporting toner particles in a dense state in the eye.

  Hereinafter, the present invention will be described in detail.

  When the toner particle dispersion is solid-liquid separated using the filter according to the present invention, toner particles are deposited along the filter surface according to the present invention to form a toner cake. As the solid-liquid separation progresses, the toner cake grows.

  The present inventors have used toner cake toner formed at a location close to a conventional type filter such as a filter cloth when the toner particle dispersion is solid-liquid separated using a conventional type filter such as a nonwoven fabric or a filter cloth. When image formation is performed using the toner, the developer tends to easily generate toner blisters, the adhesion force of the toner to adhere the external additive is weak, and the carrier surface easily contaminates the developer. We focused on the tendency to shorten the lifetime of

  In addition, when the present inventors performed solid-liquid separation of the toner particle dispersion using a conventional type filter such as a nonwoven fabric or a filter cloth, as shown in FIG. 2, the toner particles enter the filter. Focused on the formation.

  When the toner particles enter deep inside the filter, it becomes difficult to remove impurities from the surface of the toner particles due to the influence of the toner particles that have entered, and in particular, the removal of impurities from the toner particles formed on the filter surface. I guessed it was difficult.

  That is, when a conventional filter is clogged with toner particles or impurities, the amount of impurities in the toner particles of the toner cake formed on the surface of the filter increases, and the toner particles to which the impurities are gradually adhered become the entire toner cake. It was estimated that the performance of the whole toner was deteriorated.

  Accordingly, the present inventors have sought a filter that can form a toner cake without toner particles entering deep inside the filter when the toner cake is formed.

  As a result, the solid-liquid separation of the toner particle dispersion was performed using a filter having an eye that can form a solid-liquid separation surface made of toner particles as shown in FIG. 2 (filter according to the present invention). The inventors have found that even when an image is formed using toner prepared from a toner cake formed on the filter surface, toner blisters and carrier contamination do not occur, and resolution does not vary depending on toner lots.

  The reason why the impurities can be surely removed from the toner particles of the toner cake on the filter surface according to the present invention is not clear. However, when solid-liquid separation is performed, as shown in FIG. It is presumed that a solid-liquid separation surface made of particles is formed, and the impurities can be efficiently discharged out of the system while being uniformly adsorbed and desorbed by the toner cake layer.

  That is, as shown in FIG. 2, when solid-liquid separation is performed using the filter according to the present invention, toner particles are filled in the filter to form a solid-liquid separation surface with the toner particles. Solid-liquid separation is performed using the separation surface. Then, on the solid-liquid separation surface formed with the toner particles, the separation ability that impurities that have been concentrated through the mesh are discharged while maintaining the flatness just like column chromatography is developed, and the toner particle dispersion liquid It is presumed that the impurity component as well as the liquid component can be washed away from the toner particle surface of the toner cake and discharged.

  FIG. 1 is a surface and cross-sectional view showing an example of a mesh according to the present invention.

  In FIG. 1, 20 is a flat woven, 30 is a twill, 21 is a linear member constituting one, and 22 is a linear member constituting another. The flat tatami weave 20 is woven by arranging the linear members 21 constituting one side at intervals with the weaving method woven in a tatami shape, and the horizontal lines 22 are closely arranged. This weaving method is preferable because even if a thick wire diameter is used, a fine mesh can be obtained, so that solid-liquid separation can be performed even at a low pressure and excellent durability can be achieved even at a high pressure. The twill woven 30 is woven by arranging the linear members 21 constituting one side at intervals with a weave woven in a twill shape, and the horizontal lines 22 are closely arranged. This weaving method is preferable when a wire having a diameter larger than that of a plain tatami weave is used, and a finer mesh opening is obtained.

  FIG. 2 is a schematic view showing an example of a filter according to the present invention.

  In FIG. 2, 11 is a filter according to the present invention, 12 is a toner cake, 13 is a toner particle dispersion, 14 is a mesh forming a solid-liquid separation surface, 15 is a reinforcing mesh, 16 is toner particles, and 17 is a solid / liquid. The separation surface, 18 is a droplet, and 10 is an eye (pore).

  In addition, when the toner cake is formed on the surface of the filter according to the present invention, the toner particles are in a dense state and the toner particles support each other, forming a sturdy bridge and allowing only liquid components to pass through. It is speculated that.

  As a result, only the liquid flows through the gaps between the toner particles in the toner cake, and the impurities adhering to the toner particle surface are washed out together with the liquid from the toner particle surface due to the flow of the liquid. It is presumed that impurities can be removed from the toner particle surface to be formed.

  The toner produced using the filter according to the present invention includes impurities that lower the chargeability of the toner (for example, fatty acid metal salts) and impurities that reduce the electrical resistance and transfer rate (for example, free pigments, Since the free release agent or the like is removed from the toner particle surface, there is no image failure such as transfer repelling and toner blistering, and the developer durability is good.

  Thus, the technical idea of forming a solid-liquid separation surface with toner particles in the mesh of the filter and performing solid-liquid separation using the solid-liquid separation surface made of the toner particles is completely unthinkable from the prior art. It was a thing.

  FIG. 3 is a schematic view showing an example of a conventional type filter that performs solid-liquid separation in a state where toner particles enter the filter.

  In FIG. 3, 111 is a conventional filter, 12 is a toner cake, 13 is a toner particle dispersion, 16 is toner particles, 18 is a droplet, and 19 is a nonwoven fabric.

  An apparatus for forming a toner cake by solid-liquid separation of toner particles from a toner particle dispersion using the filter according to the present invention is not particularly limited. A filter press, a pressure leaf dehydrator, a pressure nutche Rotating cylindrical dehydrator, rotating disk dehydrator, etc., among them, the rotating cylindrical dehydrator can easily remove impurities from the toner cake, and good productivity can be obtained. preferable.

Next, the filter according to the present invention, solid-liquid separation from the toner particle dispersion, toner cake formation, toner cake cleaning, toner cake scraping and discharging, and filter cleaning / regeneration will be described.
(filter)
The filter according to the present invention is different from known filters such as filter paper and non-woven fabric, in which a linear member is arranged on one side at intervals, and a linear member is arranged in close contact with the other to form a mesh. It will be.

The properties required for the filter according to the present invention include (1) having an eye that forms a solid-liquid separation surface in which toner particles are filled in the filter and solid-liquid separation of the toner particle dispersion is performed.
(2) The flatness of the filter surface is ensured at the contact point between the filter and the toner cake.
(3) Do not cause clogging,
(4) Withstand the operating pressure,
(5) having wear resistance;
(6) The surface is smooth and the toner cake can be easily scraped off.
(7) The filter can be used repeatedly by washing,
(8) Be inexpensive
Etc.

  Further, in adopting the filter according to the present invention, it has become an important point that the toner particles pass and the yield does not decrease.

  As the weaving method of the linear members constituting the filter according to the present invention, flat woven, twill woven, rather woven, reverse flat woven, reverse twill woven, double twill woven, double twill woven, etc. Of these, plain woven and twill woven are preferred, and twill woven is more preferred.

  As a preferable example of the filter according to the present invention, a filter formed by integrally processing another mesh on a mesh forming a solid-liquid separation surface by performing a thermal bonding process called sintering.

  Specifically, a filter formed by integrally processing 2 to 4 meshes to form a solid-liquid separation surface by performing a thermal bonding process, the filter can withstand high operating pressure, It is excellent in that it is easy to handle and the number of times the filter can be washed and used repeatedly increases.

  FIG. 4 is a cross-sectional view showing an example of a filter composed of two meshes.

  The filter 100 shown in FIG. 4 is obtained by integrating the mesh 104 by heat bonding to the mesh 102 forming the solid-liquid separation surface in order to improve the handleability of the filter and to increase the number of times that the filter can be used repeatedly. It was produced.

  FIG. 5 is a cross-sectional view showing an example of a filter composed of five meshes.

  The filter 200 shown in FIG. 5 further includes a mesh 102 that forms a solid-liquid separation surface, a mesh 101 for protecting the scraper that scrapes off the toner cake, and ease of attachment to the apparatus and the number of times that can be repeatedly used after cleaning. In order to stretch, five meshes 103, 104, and 105 are integrally processed.

  The mesh according to the present invention is a woven linear member typified by a metal or plastic wire. Among these, a woven metal wire ensures wear resistance, increases the number of repeated use, etc. This is preferable.

  The material of the metal wire is not particularly limited as long as it can be integrated with other meshes by thermal bonding, and stainless steel (for example, SUS316L, SUS904L), nickel, or the like can be used. Among these, stainless steel SUS316L is used. Is preferable in terms of workability and strength. The material of the plastic wire is preferably a high tension and high elasticity fiber material represented by Kevlar, which has the advantage of reducing the mass of the filter itself.

  Although the wire diameter of a linear member is not specifically limited, Specifically, the thing of 10-100 micrometers is preferable.

  In the mesh according to the present invention, 12 to 240, preferably 140 to 240, linear members are arranged on one side, and 140 to 240 linear members are arranged on the other side, and 130 to 3000, preferably 270 to 3000, linear members are arranged on one side. The books are arranged and woven so as to be in close contact with each other. It has been found that good solid-liquid separation can be achieved by forming a mesh by weaving with a number falling within the above range. The mesh opening means a size of an eye formed by a region surrounded by the linear member constituting one side and the linear member constituting another side.

  The mesh opening on which the solid-liquid separation surface is formed is preferably 0.2 to 20 times, more preferably 0.5 to 10 times the number average particle diameter of the toner particles. Even if the mesh opening is about 20 times larger than the number average particle diameter of the toner particles, the solid-liquid separation is performed while the solid-liquid separation starts and the toner particles support each other and form a bridge to form a bridge. Since the surface is formed, the toner particles do not flow out through the filter.

The mesh opening of the other mesh is not particularly limited as long as it is larger than the size that allows the toner particles to pass through, and 50 to 700 μm is preferable in terms of strength, durability, and handleability.
(Toner particle dispersion is solid-liquid separated to form toner cake, and toner cake is washed)
In the present invention, the toner particle dispersion is solid-liquid separated using the filter according to the present invention to form a toner cake, and the toner cake is washed with water or alcohol.

  Specifically, as shown in FIGS. 6 to 9 described later, a toner particle dispersion containing toner particles is supplied into a tank of a rotating cylindrical dehydrator 704 equipped with a filter according to the present invention. The rotating cylindrical dehydrator 704 is operated to form a toner cake made of toner particles on the surface of the filter 307.

  Next, water is supplied into the tank of the rotary cylindrical dehydrator 704 to wash the toner cake. Washing with water is continued until the electrical conductivity of the filtrate is 50 μS / cm or less. Washing until the electrical conductivity of the filtrate reaches 50 μS / cm or less is preferable because the residual amount of impurities adhering to the toner particles is reduced. Further, it is more preferable that the washing is continued until the electric conductivity of the filtrate becomes 10 μS / cm or less because the amount of impurities adhering to the toner particles is further reduced.

  The electric conductivity of the filtrate can be measured with a normal electric conductivity meter, and “CM-10P” (manufactured by Toa Denpa Kogyo Co., Ltd.) can be given as an example of a measuring instrument.

  Although it does not specifically limit as water used for washing | cleaning, In order to make the electrical conductivity of a filtrate into 50 microsiemens / cm or less, it is preferable to use the water of electrical conductivity of 5 microsiemens / cm or less. Furthermore, you may use the water which improved the washing | cleaning performance by making the cluster of water small using magnetism or an ultrasonic wave.

  The acceleration of the rotating cylinder during cleaning is preferably 500 to 1000G, and more preferably 600 to 800G. If the acceleration is within this range, it is preferable that the cleaning water can be supplied uniformly over the entire toner cake, and impurities attached to the toner particles can be completely removed.

The supply amount of water used for washing is preferably within a range in which no washing water stays in the rotary cylindrical dehydrator. If the cleaning liquid does not stay, it is preferable that the impurities once separated from the toner particles do not cause a problem of reattaching to the toner particles.
(Scraping and discharging toner cake)
The toner cake from which impurities have been removed by washing with water is dehydrated by rotating the rotating cylinder (basket) of the rotating cylindrical dehydrator shown in FIGS. After that, the toner cake dehydrated by the scraper attached to or inserted into the rotary cylindrical dehydrator is scraped off from the surface of the filter according to the present invention, discharged from the suction pipe or the discharge port, and conveyed to the drying device of the next process. The
(Cleaning and regeneration of the filter according to the present invention)
The filter according to the present invention, which is clogged with toner particles and impurities, is taken out by a high-pressure jet flow from a high-pressure jet nozzle attached to or inserted into a rotary cylindrical dehydrator and immersed in an ultrasonic bath. Then, it is cleaned and reused by ultrasonic waves. Since the toner particles and impurities are removed by the washing, there is no problem even if it is reused.

  Next, a rotating cylindrical dehydrator used as an apparatus for forming a toner cake by solid-liquid separation of toner particles from a toner particle dispersion will be described.

  FIG. 6 is a cross-sectional view showing an example of a rotating cylindrical dehydrator.

  A rotating cylindrical dehydrator 704 shown in FIG. 6 is of a type that discharges a toner cake from the lower part. The main body 301 includes a basket 302, a basket rotating device 303, a scraping device 304, a liquid supply pipe 305, and a liquid drain. An outlet 308 and a cake discharge port 310 are attached. The scraper 304 is equipped with a scraper 306, the liquid supply pipe 305 is equipped with a liquid injection nozzle 309, and the basket 302 is equipped with a removable filter 307 according to the present invention. At the start, the toner particle dispersion is supplied from the liquid supply pipe 305, and the basket 302 is rotated at high speed to separate the solid and the liquid, thereby forming a toner cake on the surface of the filter 307 according to the present invention. The filtrate is discharged from the liquid discharge port 308.

  Thereafter, cleaning water is supplied from a liquid supply pipe 305 to clean the toner cake. The toner cake washing water is discharged from a liquid drain port 308.

  Thereafter, the washed toner cake is dehydrated by rotating the basket 302 at a high speed, and then scraped off by the scraper 306 while rotating the basket 302 at a low speed, and discharged from the cake discharge port 310.

  FIG. 7 is a cross-sectional view showing an example of a rotating cylindrical dehydrator equipped with a high-pressure jet nozzle for cleaning a filter according to the present invention.

A high pressure jet cleaning device 603 with a high pressure jet nozzle 602 is attached to the main body 301. High-pressure water (50 to 100 × 10 ⁵ Pa) is sent from the water supply pipe 601 to the high-pressure jet nozzle 602, and the high-pressure jet water is jetted from the nozzle onto the surface of the filter 307 according to the present invention. Is removed. The sprayed cleaning water is discharged from the liquid discharge port 308.

  Next, the toner manufacturing method according to the present invention will be described.

  The toner (toner particles) according to the present invention has a number average particle diameter of 3 to 10 μm, a number-based particle size distribution variation coefficient of 6 to 29%, an average circularity of 0.94 to 0.99, and a variation in circularity. The coefficient is preferably 2 to 16%.

  The number average particle size, number-based particle size distribution variation coefficient, average circularity, and circularity variation coefficient are measured by Coulter Multisizer “SD-2000” (manufactured by Sysmex Corporation). ).

  The toner particles having the shape characteristics as described above are preferable because they can be solid-liquid separated satisfactorily without being filtered out from the filter according to the present invention.

  The toner according to the present invention comprises toner particles formed by forming toner particles in an aqueous medium or an organic solvent to form a toner particle dispersion, followed by solid-liquid separation with a filter having at least two meshes. The toner can be obtained by a toner manufacturing method in which a cake is formed, impurities are washed and removed from the toner cake, dried to prepare toner particles, and external additives are added to the toner particles as necessary.

  Examples of the aqueous medium include, but are not particularly limited to, water, methanol, ethanol, isopropanol, butanol, 2-methyl-2-butanol, acetone, methyl ethyl ketone, tetrahydrofuran, or a mixture thereof. . A suitable toner can be selected from among these.

  The production method of the toner particle dispersion can be prepared by a known production method. Specifically, an emulsion association method, a suspension polymerization method, a dispersion polymerization method, a dissolution suspension method, a continuous emulsion dispersion method, etc. Although it can mention, it does not specifically limit.

  Hereinafter, a method for producing a toner particle dispersion by an emulsion association method and a dispersion polymerization method will be described.

  A method for producing a toner particle dispersion by emulsion polymerization is a method for forming toner particles in an aqueous medium, and is disclosed in, for example, JP-A-2002-351142.

  In addition, the resin particles disclosed in JP-A-5-265252, JP-A-6-329947, and JP-A-9-15904 are salted out / fused in an aqueous medium to produce a toner particle dispersion. A method can be mentioned.

  Specifically, after resin particles are dispersed in water using an emulsifier, a coagulant having a critical coagulation concentration or higher is added for salting out, and at the same time, heat fusion is performed at or above the glass transition temperature of the formed polymer itself. Gradually grow the particle size while forming fused particles, stop the particle size growth by adding a large amount of water when the desired particle size is reached, and further smooth the particle surface while heating and stirring The shape is controlled to prepare a toner particle dispersion. Here, a solvent that is infinitely soluble in water, such as alcohol, may be added simultaneously with the flocculant.

  The method for producing a toner particle dispersion by dispersion polymerization is to dissolve a monomer and a polymerization initiator simultaneously in a good solvent in which the monomer is soluble, and precipitate the polymer component that is no longer soluble in the solvent as the polymerization proceeds. It is a method of forming. As the solvent, methanol is generally used, and solid-liquid separation is generally performed in an alcohol medium, or in an aqueous medium in which water and alcohol are mixed.

  Next, a toner manufacturing method according to the present invention will be described.

  FIG. 8 is a manufacturing flow diagram (manufacturing process diagram) showing an example of a toner manufacturing method preferably used in the present invention.

  Each process is demonstrated according to the flow shown in FIG. The toner particle dispersion stocked in the tank 701 is charged into the rotary cylindrical dehydrator 704, and the balance of the supply amount of the toner particle dispersion and the amount of liquid discharged from the discharge port 308 is observed while checking the balance of the rotary cylindrical dehydrator 704. Continue operation. When a certain amount of solid-liquid separation is completed, the operation is stopped, washed with water, dehydrated, and the scraper 306 removes the toner cake from the cake discharge port 310. The taken-out toner cake is stored in a stock tank 705, preferably unwound and then sent to a drying device 706, dried with hot air 715, and then collected with a cyclone 707, and the toner particle stock tank. It is stored in 708.

  FIG. 9 is a manufacturing flow diagram (manufacturing process diagram) showing an example of a toner manufacturing method preferably used according to the present invention.

  In the flow shown in FIG. 9, the toner particle dispersion liquid stocked in the tank 701 is concentrated by the decanter 702 and then sent to the liquid preparation tank 703. In the decanter 702, impurities having a specific gravity smaller than that of water are removed in advance. In the adjustment tank 703, a diluent 711 is added to re-disperse the toner particles in the concentrated liquid and adjust the concentration to a level suitable for solid-liquid separation, and at the same time dissolve water-soluble impurities in the re-dispersed liquid. The re-dispersed toner particle dispersion is put into a rotating cylindrical dehydrator 704, and thereafter the same operation as in FIG. 9 is performed.

  Examples of the drying device include a flash jet dryer, a fluidized bed drying device, a spray dryer, a vacuum freeze-drying device, and a vacuum drying device. Two or more of these drying devices are arranged in series for drying. It is preferable to do.

  The water content of the dried toner particles is preferably 5% by mass or less, more preferably 2% by mass or less.

  The present invention will be specifically described below with reference to examples, but the embodiments of the present invention are not limited to these examples.

<< Preparation of filter according to the present invention >>
As the mesh material, SUS316L metal wire was used. As for the mesh weaving method, the mesh forming the solid-liquid separation surface was produced by twill and plain tatami mats, and the other meshes were produced by plain weaves. The filter according to the present invention was manufactured by using the metal wire diameters shown in Table 1 and integrated processing by thermal bonding (sintering). Thereafter, the filter was processed (basket diameter is 1524 mm, depth is 1020 mm) so that it can be attached to a basket of a rotating cylindrical dehydrator to produce “filters 1 to 6”.

Table 1 shows the “filters 1 to 6” according to the present invention prepared above (the present invention) and the “filter” manufactured by the nonwoven fabric prepared for comparison (Okada Canvas Co., Ltd., air flow rate 192 ml / cm ² · min). 7 "is shown.

<Manufacture of toner>
<Preparation of Toner Particle Dispersion 1 (Example of Emulsion Association Method)>
(Preparation of latex (1HML))
(1) Preparation of core particles (first stage polymerization)
An anionic surfactant in a 5000 ml separable flask equipped with a stirrer, temperature sensor, condenser, and nitrogen inlet
C ₁₀ H ₂₁ (OCH ₂ CH ₂ ) ₂ OSO ₃ Na
A surfactant solution (aqueous medium) in which 7.08 g was dissolved in 3010 g of ion-exchanged water was charged, and the temperature in the flask was raised to 80 ° C. while stirring at a stirring speed of 230 rpm under a nitrogen stream.

To this surfactant solution, an initiator solution prepared by dissolving 9.2 g of a polymerization initiator (potassium persulfate: KPS) in 200 g of ion-exchanged water was added, the temperature was adjusted to 75 ° C., and then 70.1 g of styrene, n -A monomer mixture consisting of 19.9 g of butyl acrylate and 10.9 g of methacrylic acid was added dropwise over 1 hour, and this system was polymerized by heating and stirring at 75 ° C for 2 hours (first stage polymerization). And a latex (a dispersion of resin particles made of a high molecular weight resin) was prepared. This is referred to as “latex (1H)”.
(2) Formation of intermediate layer (second stage polymerization)
In a flask equipped with a stirrer, a monomer mixture consisting of 105.6 g of styrene, 30.0 g of n-butyl acrylate, 6.2 g of methacrylic acid, and 5.6 g of n-octyl-3-mercaptopropionic acid ester was separated. As a mold, 98.0 g of a compound represented by the following formula (hereinafter referred to as “Exemplary Compound (19)”) was added, heated to 90 ° C. and dissolved to prepare a monomer solution.

Exemplary compound (19)
_{CH 3 (CH 2) 20 COOCH} 2 C (CH 2 OCO (CH 2) 20 CH 3) 3
On the other hand, a surfactant solution obtained by dissolving 1.6 g of an anionic surfactant (the above formula (101)) in 2700 ml of ion-exchanged water is heated to 98 ° C., and a dispersion of core particles is added to the surfactant solution. After adding 28 g of the above-mentioned “latex (1H)” in terms of solid content, a mechanical disperser “CLEARMIX” (manufactured by M Technique Co., Ltd.) having a circulation path is used to The monomer solution was mixed and dispersed for 8 hours to prepare a dispersion (emulsion) containing emulsified particles (oil droplets) having a dispersed particle diameter of 284 nm.

  Next, an initiator solution prepared by dissolving 5.1 g of a polymerization initiator (KPS) in 240 ml of ion-exchanged water and 750 ml of ion-exchanged water are added to this dispersion (emulsion). Polymerization (second-stage polymerization) was carried out by heating and stirring over time to obtain a latex (a dispersion of composite resin particles having a structure in which the surface of resin particles made of a high molecular weight resin was coated with an intermediate molecular weight resin). This is referred to as “latex (1HM)”.

The “latex (1HM)” was dried and observed with a scanning electron microscope. As a result, particles (400 to 1000 nm) mainly composed of the exemplified compound (19) not surrounded by the latex were observed.
(3) Formation of outer layer (third stage polymerization)
An initiator solution in which 7.4 g of a polymerization initiator (KPS) is dissolved in 200 ml of ion-exchanged water is added to the “latex (1HM)” obtained as described above, and styrene is added at a temperature of 80 ° C. A monomer mixed liquid consisting of 300 g, 95 g of n-butyl acrylate, 15.3 g of methacrylic acid, and 10.4 g of n-octyl-3-mercaptopropionic acid ester was added dropwise over 1 hour. After completion of the dropwise addition, polymerization (third stage polymerization) was performed by heating and stirring for 2 hours, followed by cooling to 28 ° C. and latex (a central part made of a high molecular weight resin, an intermediate layer made of an intermediate molecular weight resin, A dispersion of composite resin particles) having an outer layer made of a molecular weight resin and containing the exemplary compound (19) in the intermediate layer was obtained. This latex is referred to as “latex (1HML)”.

The composite resin particles constituting this “latex (1HML)” have peak molecular weights (weights) at 138,000, 80,000 and 13,000, and the weight average particle diameter of the composite resin particles is It was 122 nm.
(Preparation of toner particle dispersion)
Anionic surfactant (sodium dodecyl sulfate) 59.0 g was dissolved in 1600 ml of ion-exchanged water with stirring, and 420.0 g of “CI Pigment Blue 15: 3” was gradually added while stirring this solution. A “colorant particle dispersion” was prepared by dispersion treatment using “CLEARMIX” (manufactured by M Technique Co., Ltd.).

  Reaction in which 420.7 g of “latex (1HML)” (converted to solid content), 900 g of ion-exchanged water, and 166 g of “dispersion of colorant particles” were attached with a temperature sensor, a cooling pipe, a nitrogen introducing device, and a stirring device. It stirred in the container (four necked flask). After adjusting the temperature in the container to 30 ° C., 5 mol / L sodium hydroxide aqueous solution was added to this solution to adjust the pH to 8.

  Next, an aqueous solution obtained by dissolving 12.1 g of magnesium chloride hexahydrate in 1000 ml of ion-exchanged water was added at 30 ° C. over 10 minutes with stirring. After standing for 3 minutes, the temperature was started to rise, and the system was heated to 90 ° C. over 6 to 60 minutes to produce associated particles. In this state, the particle size of the associated particles was measured with “Coulter Counter TA-II” (manufactured by Coulter Counter Co., Ltd.). When the volume average particle size reached 6.4 μm, 80.4 g of sodium chloride was ionized. An aqueous solution dissolved in 1000 ml of exchange water was added to stop the particle growth, and further, the particles were fused by heating and stirring at a liquid temperature of 98 ° C. for 2 hours as an aging treatment.

  Thereafter, the mixture was cooled to 30 ° C., hydrochloric acid was added to adjust the pH to 4.5, and “Toner Particle Dispersion 1” was produced.

<Preparation of Toner Particle Dispersion 2 (Example of Emulsion Association Method)>
(Preparation of resin particle dispersion)
A mixture of 370 g of styrene, 30 g of n-butyl acrylate, 8 g of acrylic acid, 24 g of dodecanethiol, and 4 g of carbon tetrabromide was dissolved in 6 g of a nonionic surfactant “nonylphenyl ether” and an anionic surfactant “ Emulsion polymerization was carried out in a flask in which 10 g of sodium dodecylbenzenesulfonate was dissolved in 550 g of ion-exchanged water, and 50 g of ion-exchanged water in which 4 g of ammonium persulfate was dissolved was added thereto while slowly mixing for 10 minutes. After carrying out nitrogen substitution, the inside of the flask was stirred and heated in an oil bath until the contents reached 70 ° C., and emulsion polymerization was continued for 5 hours. As a result, “resin fine particle dispersion 2” in which resin particles having a volume average particle diameter = 150 nm, a glass transition temperature = 58 ° C., and a weight average molecular weight = 11500 was dispersed was obtained. The solid content concentration of this dispersion was 40% by mass.

(Preparation of colorant dispersion)
Colorant “CI Pigment Blue 15: 3” 60 parts by weight Nonionic surfactant “Noniphenyl ether” 5 parts by weight Ion-exchanged water 240 parts by weight After mixing and dissolving the above components, the homogenizer “Ultra Turrax T50” (“IKA Co., Ltd.”) for 10 minutes, and then dispersed with an optimizer to prepare “Colorant Dispersion 2” in which colorant particles having a volume average particle diameter of 250 nm are dispersed. .

(Preparation of release agent dispersion)
Paraffin wax (melting point 97 ° C.) 100 parts by weight Cationic surfactant “alkyl ammonium salt” 5 parts by weight Ion-exchanged water 240 parts by weight The product was dispersed for 10 minutes using a pressure discharge type homogenizer, and “release agent dispersion 2” in which release agent particles having a volume average particle size of 550 nm were dispersed was prepared.
(Preparation of aggregated particles)
Resin fine particle dispersion 2 234 parts by weight Colorant dispersion 2 30 parts by weight Release agent dispersion 2 40 parts by weight Polyaluminum chloride 1.8 parts by weight Ion-exchanged water 600 parts by weight In the round stainless steel flask After mixing and dispersing using a homogenizer “Ultra Turrax T50” (manufactured by IKA Corporation), the mixture was heated to 55 ° C. while stirring the inside of the flask in a heating oil bath. After maintaining at 55 ° C. for 30 minutes, it was confirmed that aggregated particles having D50 of 4.8 μm were formed in the solution. Further, when the temperature of the heating oil bath was raised and held at 56 ° C. for 2 hours, D50 was 5.9 μm. Thereafter, 32 parts by mass of “resin fine particle dispersion 2” is added to the dispersion containing the aggregated particles, and then the temperature of the heating oil bath is raised to 55 ° C. and held for 30 minutes to prepare “aggregated particles 2”. did. After adding 1 mol / L sodium hydroxide to the dispersion containing “aggregated particles 2” and adjusting the pH of the system to 5.0, the stainless steel flask was sealed with a magnetic seal and stirring was continued. The resulting mixture was heated to 95 ° C. and held for 6 hours to prepare “Toner Particle Dispersion 2”.

<Preparation of Toner Particle Dispersion 3 (Example of Polyester Association Method)>
(Preparation of polyester resin)
715.0 g of dimethyl terephthalate, 95.8 g of sodium dimethyl 5-sulfoisophthalate, 526.0 g of propanediol, 48.0 g of diethylene glycol, 247.1 g of dipropylene glycol, and 1.5 g of butyltin hydroxide catalyst Placed in polycondensation reactor. The mixture was heated to 190 ° C. and slowly raised to about 200-202 ° C. while collecting methanol by-product in the distillation receiver. Next, the temperature was raised to about 210 ° C. while reducing the pressure from atmospheric pressure to about 1067 Pa over about 4.5 hours. The product was taken out to prepare “Polyester Resin 3” having a glass transition temperature of 53.8 ° C.

(Preparation of polyester resin emulsion)
Next, 168 g of the above-mentioned “polyester resin 3” was added to 1,232 g of deionized water and stirred at 92 ° C. for 2 hours to prepare “polyester resin emulsion 3”.

(Meeting process)
1,400 g of “Polyester Resin Emulsion 3” and 14.22 g of “CI Pigment Blue 15: 3” were added to the reactor to prepare “Emulsion / Dispersion 3”.

  Next, zinc acetate was dissolved in deionized water to prepare a 5 mass% zinc acetate solution. This solution was placed in a reservoir placed on a balance and connected to a pump capable of accurately supplying a zinc acetate solution at 0.01-9.9 ml / min. The amount of zinc acetate required for emulsion association is 10% of the resin mass in the emulsion.

  After “Emulsion / Dispersion 3” was heated to 56 ° C., the zinc acetate solution was pumped at 9.9 ml / min to initiate association. After adding 60% by weight of the total amount of zinc acetate (205 g for a 5% by weight solution), the pump addition rate was reduced to 1.1 ml / min and the amount of zinc acetate was equal to 10% by weight of the resin in the emulsion (5 The addition was continued until 335 g in a mass% solution, and the mixture was stirred at 80 ° C. for 9 hours to prepare “Toner Particle Dispersion 3”.

<Preparation of Toner Particle Dispersion 4 (Example of Suspension Polymerization Method)>
165 g of styrene, 35 g of n-butyl acrylate, 10 g of “CI Pigment Blue 15: 3”, 2 g of metal compound of di-t-butylsalicylate, 8 g of styrene-methacrylic acid copolymer, 20 g of paraffin wax (mp = 70 ° C.) The mixture was heated to 60 ° C., and uniformly dissolved and dispersed at 12000 rpm using a “TK homomixer” (manufactured by Tokushu Kika Kogyo Co., Ltd.). To this, 10 g of 2,2′-azobis (2,4-valeronitrile) as a polymerization initiator was added and dissolved to prepare “polymerizable monomer composition 4”. Next, 450 g of 0.1 M sodium phosphate aqueous solution was added to 710 g of ion-exchanged water, and 68 g of 1.0 M calcium chloride was gradually added while stirring at 13,000 rpm with a “TK homomixer” to disperse tricalcium phosphate. Liquid 4 "was prepared. The above-mentioned “polymerizable monomer composition 4” is added to this “suspension 4” and stirred at 10,000 rpm for 20 minutes with “TK homomixer” to granulate “polymerizable monomer composition 4”. did. Then, it was made to react at 75-95 degreeC for 5 to 15 hours using the reaction apparatus. The tricalcium phosphate was dissolved and removed with hydrochloric acid to prepare “Toner Particle Dispersion 4”.

<Preparation of toner particle dispersion 5 (example of dissolution suspension method)>
(Preparation of pigment dispersion)
50 parts by mass of polyester resin (Tg: 60 ° C., softening point: 98 ° C., weight average molecular weight: 9500)
C. I. Pigment Blue 15: 3 50 parts by mass Ethyl acetate 100 parts by mass A container obtained by adding glass beads to the dispersion having the above material composition was attached to a sand mill disperser. While cooling around the vessel, the dispersion was carried out for 8 hours in a high-speed stirring mode, and then diluted with ethyl acetate to prepare “Pigment Dispersion Liquid 5” having a pigment concentration of 15% by mass.

(Preparation of micronized wax dispersion)
Paraffin wax (melting point: 85 ° C.) 15 parts by mass Toluene 85 parts by mass The above materials were placed in a dispersing machine equipped with a stirring blade and having a function of circulating a heat medium around the container. The temperature was gradually raised while stirring at 83 rpm, and finally the mixture was stirred for 3 hours while maintaining at 100 ° C. Next, while continuing stirring, the mixture was cooled to room temperature at a rate of about 2 ° C. per minute to precipitate finely divided wax. This wax dispersion was dispersed again at a pressure of 550 × 10 ⁵ Pa using a high-pressure emulsifier “APV Gorin homogenizer” (manufactured by APV Gorin Co., Ltd.). At the same time, the viscosity of the wax was measured and found to be 0.69 μm. The prepared fine particle wax dispersion was diluted with ethyl acetate so that the mass concentration of the wax was 15% by mass to prepare “fine particle wax dispersion 5”.

(Preparation of oil phase)
85 parts by mass of polyester resin (Tg: 60 ° C., softening point: 98 ° C., weight average molecular weight: 9500)
Pigment dispersion 5 (pigment concentration 15% by mass) 50 parts by mass Fine particle wax dispersion 5 (wax concentration 15% by mass) 33 parts by mass Ethyl acetate 32 parts by mass The polyester resin in the material composition was sufficiently dissolved. After confirmation, this solution was put into a homomixer “ACE Homogenizer” (manufactured by Nippon Seiki Co., Ltd.) and stirred at 16000 rpm for 2 minutes to prepare a uniform “oil phase 5”.

(Preparation of aqueous phase)
Calcium carbonate (average particle size: 0.03 μm) 60 parts by mass Pure water 40 parts by mass An aqueous calcium carbonate solution obtained by stirring the above materials with a ball mill for 4 days was referred to as “aqueous phase (calcium carbonate aqueous solution) 5”. When the average particle diameter of calcium carbonate was measured using “Laser diffraction / scattering particle size distribution measuring apparatus A-700” (manufactured by Horiba, Ltd.), it was about 0.08 μm.

Carboxymethylcellulose 2 parts by mass Pure water 98 parts by mass An aqueous solution of carboxymethylcellulose obtained by stirring the above materials with a ball mill was designated as “aqueous phase (carboxymethylcellulose aqueous solution) 5”.

(Preparation of spherical particles)
Oil phase 5 55 parts by mass Aqueous phase (calcium carbonate aqueous solution) 5 15 parts by mass Aqueous phase (carboxymethylcellulose aqueous solution) 5 30 parts by mass The above materials were put into a “colloid mill” (manufactured by Nippon Seiki Co., Ltd.). Emulsification was performed at 5 mm, 9400 rpm for 40 minutes. Next, the emulsion was put into a rotary evaporator, and the solvent was removed under reduced pressure at room temperature of 4,000 Pa for 3 hours.

  Thereafter, 12 mol / L hydrochloric acid was added until the pH reached 2, and calcium carbonate was removed from the toner surface. Thereafter, 10 mol / L sodium hydroxide was added until the pH reached 10, and stirring was continued for 1 hour while stirring in an ultrasonic cleaning tank to prepare “toner particle dispersion 5”.

<Preparation of Toner Particle Dispersion 6 (Example of Continuous Emulsion Dispersion Method)>
(Synthesis of polyether resin (A))
In a high-pressure reactor equipped with a stirrer, a nitrogen inlet tube, a thermometer, a raw material inlet, etc., 0.5 parts by mass of potassium hydroxide and 200 parts by mass of toluene as a solvent are placed, and the pressure in the system is 10 × 10 ⁵ Pa, while maintaining the temperature at 40 ° C., a mixture of 10.8 parts by mass of propylene oxide and 89.2 parts by mass of styrene oxide was injected little by little, and the state of molecular weight change was traced by end group determination. The reaction was terminated when the number average molecular weight reached 7,000. The total amount of the monomer injected at this time was 8.64 parts by mass of propylene oxide and 71.4 parts by mass of styrene oxide. Toluene and unreacted monomers were distilled off from the resulting polymer solution under a reduced pressure of 4,000 Pa to obtain “polyether resin (A)”.

(Synthesis of polyester resin (B) having no ether bond)
In a flask having an internal volume of 5 liters equipped with a stirrer, a nitrogen introduction tube, a thermometer, and a rectifying column, 67.85 parts by mass of terephthalic acid, 3.34 parts by mass of neopentyl glycol, 25.58 parts by mass of propylene glycol, 3.22 parts by mass of trimethylolpropane and 0.3 parts by mass of dibutyltin oxide were added, and the reaction was allowed to stir at 240 ° C. under a nitrogen stream. The reaction was terminated when the softening point by the ring and ball method reached 130 ° C. to obtain “polyester resin (B)”. The obtained “polyester resin (B)” was a light yellow solid, and the weight average molecular weight in terms of polystyrene by GPC measurement was 96,000.

18 parts by mass of “polyether resin (A)”, 72 parts by mass of “polyester resin (B)” and 10 parts by mass of “CI Pigment Blue 15: 3” were used using a biaxial continuous kneader. A colored resin melt heated to 180 ° C. was transferred to a rotary continuous dispersion apparatus “Cabitron CD1010” (manufactured by Eurotech Co., Ltd.) at a rate of 100 g / min. Separately prepared aqueous medium tank is filled with 0.37 mass% diluted ammonia water diluted with ion-exchanged water and heated at 150 ° C. with a heat exchanger at a rate of 0.1 liter per minute. The colored resin melt is transferred to the Cavitron at the same time, and a dispersion liquid having a temperature of 160 ° C. in which the colored resin spherical fine particles are dispersed is obtained under operating conditions of a rotor rotation speed of 7500 rpm and a pressure of 5 × 10 ⁵ Pa. The mixture was cooled to a temperature of 40 ° C. in 10 seconds to prepare “Toner Particle Dispersion 6”.

<Preparation of Toner Particle Dispersion 7 (Example of Dispersion Polymerization Method)>
8 parts by weight of polyvinyl butyral (polyvinyl acetate unit: 2% by weight, polyvinyl alcohol unit: 19% by weight, polyvinyl acetal unit: 79% by weight, average degree of polymerization: 630), 300 parts by weight of 2-methyl-2-butanol, styrene A mixture consisting of 82 parts by mass and 18 parts by mass of n-butyl acrylate was sufficiently dissolved, and 7 parts by mass of “CI Pigment Blue 15: 3” and 500 parts by mass of glass beads (diameter 1 mm) were added thereto. After stirring for 6 hours with a paint shaker, the glass beads were removed with a mesh to prepare “Dispersion 7”.

  While maintaining a polymerization vessel equipped with a mechanical stirrer and an introduction tube for nitrogen bubbling at 15 ° C., 300 parts by mass of the obtained “dispersion 7” and 2,2′-azobisisobutyronitrile 3.6 parts by mass were gradually added to form a polymerization reaction system. The pigment dispersion rate ψ of the polymerization reaction system at this time was 1.01. Further, the amount of dissolved oxygen in the polymerization reaction system was 8.2 mg / liter.

  While maintaining the polymerization reaction system at 20 ° C., nitrogen was bubbled into the liquid until the amount of dissolved oxygen in the polymerization reaction system reached 0.2 mg / liter. This was heated to 75 ° C. and polymerized with stirring for 12 hours. Nitrogen bubbling was continued during the polymerization.

  After completion of the reaction, the mixture was cooled to 20 ° C. with stirring and decanted to prepare “Toner Particle Dispersion 7”.

The “toner particle dispersions 1 to 7” produced above were solid-liquid separated, washed and dried according to the production flow shown in FIG. 10 to obtain toner particles. That is, after concentration by a decanter to remove impurities having a small specific gravity, the solution is sent to a liquid preparation tank. In the adjustment tank, a diluent was added, and the toner particles in the concentrated liquid were redispersed and adjusted to a concentration suitable for solid-liquid separation. After that, solid-liquid separation was performed with a rotary cylindrical dehydrator “MARK III model number 60 × 40” (manufactured by Matsumoto Kikai Co., Ltd.) in which “filters 1 to 7” shown in Table 1 were mounted in the order shown in Table 2. A toner cake was formed. The toner cake was washed with water in a rotary cylindrical dehydrator, and then the toner cake was scraped off by a scraper inserted into the machine, discharged from the machine, and stored in a container. Thereafter, the toner cake was supplied little by little to “flash jet dryer” (manufactured by Seishin Enterprise Co., Ltd.) and dried until the water content of the toner particles became 0.5% by mass to produce “toner particles 1 to 10”. .
<Production of toner>
To 100 parts by mass of the “toner particles 1 to 10” produced above, 0.8 part by mass of rutile-type titanium oxide (volume average particle size = 20 nm, n-decyltrimethoxysilane treatment), spherical monodispersed silica (sol-gel method) The silica sol obtained in HMDS was subjected to HMDS treatment, dried and pulverized and mixed with 1.8 parts by mass of “Henschel mixer” (circumferential speed 30 m / s) (Mitsui Miike Chemical Co., Ltd.) For 15 minutes. Thereafter, coarse particles were removed using a filter having an opening of 45 μm to produce “Toners 1 to 10”, which were designated as “Examples 1 to 9” and “Comparative Example 1”.
<< Preparation of developer >>
Each of the “toners 1 to 10” produced above was mixed with a ferrite carrier having a volume average particle diameter of 60 μm to prepare “developers 1 to 10” having a toner concentration of 6%.

  Table 2 shows the toner particle dispersion used for preparing the toner, the filter used, the opening of the filter, the toner particle characteristics, and the time until the filter becomes clogged and needs to be replaced.

《Filter playback》
After discharging the toner cake, high-pressure water (70 × 10 ⁵ Pa) is jetted from the beam type nozzle of the high-pressure jet cleaning device installed in the rotary cylindrical dehydrator, and the toner particles and impurities clogged in the filter Was removed. Thereafter, the entire rotary cylindrical dehydrator was dried with hot air from the nozzle to complete the regeneration of the filter.

<Evaluation>
<Live-action evaluation>
The toner and the developer were set in a developing device of a commercially available image forming apparatus “Konica 9331” (manufactured by Konica Corporation) adopting an electrophotographic method, and printing was performed. The following evaluation items were evaluated. The image density was measured using a “Macbeth RD-918 densitometer” (manufactured by Macbeth).

(Transfer repelling)
32 sheets of cardboard (200 g / m ² ) were continuously printed at low temperature and low humidity (10 ° C., 20% RH). A halftone having a relative density of 0.2 to 0.3 was printed, and transfer repelling (mottle) due to discharge generated at the rear end of the image was visually confirmed.

Evaluation Criteria ◎ No transfer repellency is good. ○ There are 1 to 2 transfer repellations that cannot be detected without staring, but there is no problem in practical use.

(Toner blister)
The process was adjusted so that the toner adhesion amount on the transfer material was 1.6 mg / cm ² to form a printed image. The image was observed using a microscope to evaluate whether there was a hole having a diameter of about 0.1 to 0.5 mm, that is, a toner blister.

Evaluation criteria ◎ No toner blisters and no problem ○ There are 1 to 2 toner blisters per 4 cm ^2, but there is no practical problem because they cannot be understood without staring visually × 3 or more clear per 4 cm ² There is a problem in practical use because there is a toner blister.

(Developer durability)
The durability of the developer was evaluated based on the number of printed sheets until fog, density reduction, etc. occurred in the printed image, the utility was lost, and the developer had to be replaced.

Evaluation criteria ◎ Excellent durability without replacement of developer over 2.5 million prints ○ Durability replacement was necessary for 1 to 2.5 million prints, but durability was good × Durability needed for developer replacement for less than 1 million prints Bad. However, printing continued to 1 million prints.

<Use amount of washing water>
The amount of washing water used was the amount of washing water used to reduce the electrical conductivity of the filtrate to 10 μS / cm when the toner cake was washed with the rotating cylindrical dehydrator. The mass ratio to the amount of toner particles in the toner particle dispersion (the amount of washing water used / the amount of toner particles in the toner particle dispersion charged in a rotating cylindrical dehydrator) was evaluated.

  The electrical conductivity was measured using “CM-10P” (manufactured by Toa Denpa Kogyo Co., Ltd.).

Evaluation Criteria ◎ Less than 10 times the amount used is very small and excellent ○ 10 to 30 times the amount used is small and good × 30 times the amount is more practical and unproductive due to poor productivity.

  Table 3 shows the evaluation results of transfer repellency, toner blister, developer durability, and amount of cleaning water used.

  As is apparent from Table 3, “Examples 1 to 9”, which are toners obtained by mounting the filter according to the present invention, have no problems in terms of transfer repelling, toner blistering, and developer durability, and for a long time. A good image can be stably obtained over a long period of time, and the amount of washing water used is small and has an excellent effect.

It is the surface and sectional drawing which show an example of the mesh which concerns on this invention. It is the schematic which shows an example of the filter concerning this invention. It is the schematic which shows an example of the conventional type filter which performs solid-liquid separation in the state in which the toner particle entered the inside of a filter. It is sectional drawing which shows an example of the filter concerning this invention comprised from two meshes. It is sectional drawing which shows an example of the filter which concerns on this invention comprised from five meshes. It is sectional drawing which shows an example of a rotation cylindrical type dehydrator. It is sectional drawing which shows an example of the rotation cylindrical type dehydrator with which the high pressure jet nozzle which wash | cleans the filter which concerns on this invention was attached. FIG. 4 is a production flow diagram (production process diagram) showing an example of a toner production method preferably used in the present invention. FIG. 6 is a manufacturing flow diagram (manufacturing process diagram) showing an example of a toner manufacturing method preferably used according to the present invention.

Explanation of symbols

305 Liquid supply pipe 306 Scraper 308 Liquid discharge port 310 Cake discharge port 601 Washing water supply pipe 11 Filter according to the present invention 12 Toner cake 13 Toner particle dispersion 14 Mesh forming solid-liquid separation surface 15 Reinforcing mesh 16 Toner Particle 17 Solid-liquid separation surface 18 Liquid droplet 701 Tank 702 Decanter 703 Adjustment tank 704 Rotating cylindrical dehydrator 705 Stock tank 706 Drying device 707 Cyclone 708 Toner particle stock tank 715 Hot air

Claims (3)

In a toner manufacturing method including a step of solid-liquid separating a toner particle dispersion containing toner particles formed in an aqueous medium or an organic solvent using a filter, the filter has a mesh, And the linear members constituting the other one are arranged in close contact with each other, and when the toner particle dispersion is put into the filter, A method for producing a toner, comprising forming a solid-liquid separation surface made of toner particles in a mesh and performing solid-liquid separation. In the mesh, the linear members constituting the one side are arranged at intervals of 12 to 240 lines / cm, and the linear members constituting the other side are arranged in close contact with 130 to 3000 lines / cm. The toner manufacturing method according to claim 1, wherein the toner is formed. 3. A toner manufacturing method, wherein the toner particle dispersion is once concentrated by a solid-liquid separation operation, and then the dispersion dispersed again in an aqueous medium is subjected to solid-liquid separation by the method according to claim 1 or 2.

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