JP2004258605A - Method for manufacturing toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a toner which attains a stable image formation without causing image defects. <P>SOLUTION: The method for manufacturing the toner includes a process of subjecting a toner particle dispersion liquid containing toner particles formed in an aqueous medium or in an organic solvent to solid-liquid separation by using a filter. The filter has a mesh, and the mesh comprises linear members constituting the one direction of the mesh arranged at certain intervals and linear members constituting another direction of the mesh arranged at specified intervals. When the toner particle dispersion liquid is fed to the filter, a solid-liquid separation face comprising the toner particles is formed in the pores of the mesh to carry out the solid-liquid separation. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to a method for producing a toner, and more particularly to a method for producing 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, instead of toners manufactured by mechanical pulverization, toners obtained by wet granulation have attracted attention because they are advantageous for reducing the particle size, sharpening the particle size distribution, and introducing a large amount of a release agent. . Specific examples of the wet toner granulation method include an emulsion association method, a suspension polymerization method, a dispersion polymerization method, and a dissolution suspension method using a separately polycondensed polyester or the like.

  A polymerized toner by an emulsion association method that forms toner particles 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, and Thus, a toner having a rounded shape with no corners on the surface of each toner particle having a uniform shape can be obtained (for example, see Patent Document 1).

  Since a high-resolution image is expected from the toner having such a uniform size and shape, a minute dot image of, for example, 1200 dpi (dpi represents the number of dots per inch (2.54 cm)) is formed. Investigation of adoption of digital type image formation is becoming active.

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

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

  Further, there is disclosed a technique in which a cleaning liquid is added to a toner particle from which an aqueous medium has been removed in a container provided with a stirring blade and a filter, the mixture is 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 detached from the toner particles, or decomposed particles thereof remaining on the toner particles even if the ordinary washing operation is repeated.

  In fact, when an image is formed using the toner obtained through the cleaning method disclosed in the above-mentioned patent document, a problem called a toner blister in which a white granular image defect occurs in a high density portion on the image has occurred. This is presumed to be due to the fact that the impurities remaining in the toner particles are hydrated and are discharged as water vapor by heating in the fixing step, which destroys the toner layer when discharged in the form of bubbles, thereby causing image defects.

  As described above, a technique for cleaning toner particles while completely removing impurities from the toner particles by a known solid-liquid separation unit has not been established.

In addition, the filter is clogged by solid-liquid separation of a small amount of toner particle dispersion, so it is necessary to replace the filter with a new filter each time the filter is clogged. It has been difficult to quickly and efficiently perform liquid-solid separation 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 has as its object to provide a toner manufacturing method for manufacturing a toner capable of performing stable image formation without causing image defects on a toner image. And

The object of the present invention is achieved by employing the following configuration.
(Claim 1)
A toner production method comprising 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, wherein the filter has a mesh, and the mesh has one side. And the linear members constituting the other one are arranged at regular intervals, and the toner particle dispersion liquid was charged into the filter. A method for producing a toner, characterized in that sometimes a solid-liquid separation surface made of toner particles is formed in pores of the mesh, and solid-liquid separation is performed.
(Claim 2)
The mesh is formed by arranging linear members constituting one side and linear members constituting another side at intervals of 60 to 3000 lines / cm, at intervals. 2. The method for producing a toner according to item 1.
(Claim 3)
3. A method for producing a toner, comprising: concentrating the toner particle dispersion once by a solid-liquid separation operation; and then separating the dispersion dispersed in an aqueous medium again by the method according to claim 1 or 2.

  ADVANTAGE OF THE INVENTION 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 toner particles. The effect is excellent.

  In the configuration according to claim 1, a filter having a mesh in which one linear member and another linear member are arranged at a predetermined interval (hereinafter, a filter according to the present invention) ) To perform solid-liquid separation of the toner particle dispersion. Then, it has been found that when an image is formed using the toner obtained through such a manufacturing method, a good toner image free from image defects caused by toner blisters can be obtained.

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

  The term “toner particle dispersion” as used in the present invention refers to a liquid obtained by dispersing toner particles on which particle formation has been completed in a toner production process.

  The "mesh" in the present invention is a component of the filter according to the present invention, and is formed by combining or weaving linear members made of metal or resin. That is, the filter according to the present invention has a plain weave structure described later by alternately weaving the linear members. Then, mesh eyes are formed in an area surrounded by the alternately woven linear members.

  In the present invention, a linear member constituting one of the linear members and a linear member constituting the other one of the linear members are arranged at a predetermined interval to constitute a filter. Here, "one" refers to a state in which the linear members are arranged in an arbitrary direction, and "another" refers to a state in which the linear members are substantially orthogonal to the linear member arranged in one of the above. This refers to a 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 one.

  The term “solid-liquid separation” as used in the present invention means that a liquid component is removed from a toner particle dispersion liquid to separate toner particles, and the separated water-containing toner particles are formed into a toner mass (toner cake) having a predetermined shape called a toner cake. (Bulk material).

  In the present invention, the “solid-liquid separation surface” is a surface on which a liquid component is removed from a toner particle dispersion liquid. In the present invention, as described above, the toner particles enter the pores of the mesh and are filled. A state in which toner particles are densely supported by each other in the pores.

  Hereinafter, the present invention will be described in detail.

  When the toner particle dispersion is subjected to solid-liquid separation 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. Then, the toner cake grows as the solid-liquid separation proceeds.

  The present inventors use a conventional filter such as a non-woven fabric or a filter cloth to separate the toner particle dispersion liquid into a solid and a liquid, and remove the toner of the toner cake formed at a location close to the conventional filter such as a filter cloth. When the toner is used to form an image, the toner has a tendency to easily generate blisters, the toner has a weak adhesive force for adhering an external additive, and further, the carrier surface is easily contaminated and It has been noticed that it has a tendency to shorten the life of the.

  Further, 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, and as shown in FIG. 2, the state in which the toner particles entered the filter was observed. We paid attention to the formation.

  When the toner particles penetrate deep into the interior of the filter, the inventors have found that it is difficult to remove impurities from the surface of the toner particles due to the influence of the entered toner particles, and in particular, to remove impurities from the toner particles formed on the filter surface. Supposed to be difficult.

  That is, when the conventional type filter becomes clogged with toner particles or impurities, the amount of impurities in the toner particles of the toner cake formed on the filter surface increases, and the toner particles having the impurities gradually adhere to the entire toner cake. It was presumed that the overall performance of the toner was deteriorated.

  Therefore, the present inventors have sought a filter capable of forming a toner cake when toner particles enter deep into the filter when the toner cake is formed.

  In the groping, as shown in FIG. 1, a linear member constituting one side is arranged at intervals, and a mesh formed by arranging linear members constituting another side at a constant interval is provided. The toner particle dispersion was subjected to solid-liquid separation using a filter (filter according to the present invention) to form a toner cake. Further, they have found that toner blisters and carrier contamination do not occur even when an image is formed using a toner prepared from the toner cake formed on the filter surface according to the present invention.

  Although it is not clear why the impurities can be surely removed from the toner particles of the toner cake on the filter surface according to the present invention, it is supposed that when the solid-liquid separation is performed, the toner is contained in the filter as shown in FIG. It is presumed that the solid-liquid separation surface was formed by the particles, and the liquid component containing impurities could be smoothly removed by using the solid-liquid separation surface.

  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 pores of the mesh, and a solid-liquid separation surface made of toner particles is formed. Solid-liquid separation is performed on the solid-liquid separation surface. Then, on the solid-liquid separation surface formed by the toner particles, a separation capability is exhibited in which the concentrated impurities pass through the mesh and are discharged while maintaining the flatness just like column chromatography, and the toner particle dispersion liquid is formed. It is presumed that the impurity component together with the liquid component can be washed out from the toner particle surface of the toner cake and discharged.

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

  In FIG. 1, 20 is a plain weave, 30 is a twill weave, 21 is a linear member constituting one, and 22 is a linear member constituting another. In the plain weave 20, a linear member 21 constituting one side and a linear member 22 constituting another side are woven so as to intersect one by one at a constant interval. In the twill weave 30, a linear member 21 constituting one side and a linear member 22 constituting another side are woven so as to keep a constant interval and cross over each other by two or more. These weaves are preferable because they have fine openings (pores) even if they have a large wire diameter, so that solid-liquid separation can be performed even at a low pressure and durability is maintained at a high pressure.

  FIG. 2 is a schematic diagram illustrating an example of the filter according to the present invention.

  2, reference numeral 11 denotes a filter according to the present invention, 12 denotes a toner cake, 13 denotes a toner particle dispersion, 14 denotes a mesh forming a solid-liquid separation surface, 15 denotes a reinforcing mesh, 16 denotes toner particles, and 17 denotes a solid-liquid. The separation surface 18 indicates a droplet.

  Further, 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 mutually support each other, forming a strong bridge and allowing only the liquid component to pass. It is presumed to have been done.

  As a result, only the liquid flows through the gap 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 by the flow of the liquid. It is presumed that impurities could be removed from the surface of the toner particles to be formed.

  In the toner manufactured by using the filter according to the present invention, since impurities (for example, fatty acid metal salt) and free pigments which lower the chargeability of the toner are removed from the surface of the toner particles, the toner film is formed by half-toning. No image defects such as uneven tone density, image deletion, toner blister, etc., no carrier contamination, and good developer durability.

  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 hardly conceivable from the prior art. Was something.

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

  3, reference numeral 111 denotes a conventional filter, 12 denotes a toner cake, 13 denotes a toner particle dispersion, 16 denotes toner particles, 18 denotes droplets, and 19 denotes a nonwoven fabric.

  The apparatus for solid-liquid separating the toner particles from the toner particle dispersion using the filter according to the present invention to form a toner cake is not particularly limited, and may be a filter press, a pressurized leaf dehydrator, a pressurized nutsche. , A rotary cylindrical type dehydrator, a rotary disk type dehydrator, etc., among these, the rotary cylindrical type dehydrator can easily remove impurities from the toner cake and obtain good productivity. preferable.

Next, the filter according to the present invention, formation of a toner cake by solid-liquid separation from a toner particle dispersion, washing of the toner cake, scraping and discharging of the toner cake, and washing and regeneration of the filter will be described.
(filter)
The filter according to the present invention is different from known filters such as filter paper and nonwoven fabric in that a mesh is formed by arranging linear members constituting one side and linear members constituting another side so as to keep a constant interval. It is.

The characteristics required of the filter according to the present invention include (1) that the filter is filled with toner particles and has pores forming a solid-liquid separation surface for performing solid-liquid separation of the toner particle dispersion;
(2) flatness is ensured on the filter surface at the point of contact between the filter and the toner cake;
(3) not to cause clogging;
(4) Withstand operating pressure;
(5) abrasion resistance;
(6) The surface is smooth and the toner cake is easily scraped off.
(7) The filter can be used repeatedly by washing,
(8) Inexpensive,
And the like.

  Further, in adopting the filter according to the present invention, it was also important that the toner particles pass and the yield does not decrease.

  Examples of the weaving method of the linear member constituting the filter according to the present invention include plain weaving, twill weaving, semi-twill weaving, and double weaving, but plain weaving and twill weaving are preferred.

  As a preferred example of the filter according to the present invention, a filter formed by integrally processing a mesh forming a solid-liquid separation surface with another mesh by performing a heat bonding process called sintering can be given.

  Specifically, a filter formed by integrally processing two to four meshes by performing a heat bonding process on a mesh forming a solid-liquid separation surface, and the filter can withstand high operation pressure; It is excellent in that it is easy to handle and that the number of times the filter can be washed and used repeatedly increases.

  FIG. 4 is a cross-sectional view illustrating an example of a filter including two meshes.

  The filter 100 of FIG. 4 is integrated with a mesh 102 that forms a solid-liquid separation surface by thermal bonding to improve the handleability of the filter and to increase the number of times that the filter can be repeatedly used by washing. It was made.

  FIG. 5 is a cross-sectional view illustrating an example of a filter including five meshes.

  The filter 200 of FIG. 5 further includes a mesh 102 for forming a solid-liquid separation surface, a mesh 101 for protecting against a scraper for scraping a toner cake, and an easy installation to an apparatus and the number of times of washing and repeated use. Five meshes 103, 104, and 105 are integrally processed in order to extend the meshes.

  The mesh according to the present invention is obtained by weaving a linear member typified by a metal or plastic wire, and among these, the one woven by a metal wire ensures abrasion resistance and increases the number of times of repeated use. It is preferred in terms of.

  The material of the metal wire is not particularly limited as long as it can be integrated with another mesh by thermal bonding, and stainless steel (for example, SUS316L, SUS904L), nickel, or the like can be used. Among these, stainless steel SUS316L Are preferred in view of workability and strength. Further, as a material of the plastic wire, a fiber material having high tension and high elasticity represented by Kevlar is preferable, and has an advantage of reducing the mass of the filter itself.

  Although the wire diameter of the linear member is not particularly limited, it is specifically preferably 10 to 100 μm.

  The mesh according to the present invention is woven by arranging linear members constituting one side and linear members constituting another side at a constant interval of 60 to 3000, preferably 120 to 800, per cm. It was formed. It has been found that good solid-liquid separation can be performed by forming a mesh by weaving the linear members in a number within the above range. The mesh openings (pores) refer to the size of the mesh formed by a region surrounded by the linear member constituting one of the above and the linear member constituting the other of the above.

  The aperture of the mesh 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 size of the toner particles. Even if the opening of the mesh is about 20 times larger than the number average particle diameter of the toner particles, the toner particles are packed together while forming a bridge by mutually supporting the openings when the solid-liquid separation is started. Since the surface is formed, the toner particles do not flow out of the filter.

The mesh size of the other meshes is not particularly limited as long as it is at least the size that allows the toner particles to pass through, and is preferably 50 to 700 μm in terms of strength, durability and handleability.
(Formation of toner cake by solid-liquid separation of toner particle dispersion, washing of toner cake)
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, a toner particle dispersion containing toner particles is supplied into a tank of a rotary cylindrical dehydrator equipped with the filter according to the present invention, and the rotary cylindrical dehydrator is operated to operate the surface of the filter. To form a toner cake composed of toner particles.

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

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

  The water used for washing is not particularly limited, but water having an electric conductivity of 5 μS / cm or less is preferably used in order to make the electric conductivity of the filtrate 50 μS / cm or less. Further, water whose cleaning performance is improved by reducing clusters of water using magnetism or ultrasonic waves may be used.

  The acceleration of the rotating cylinder at the time of cleaning is preferably 500 to 1000 G, more preferably 600 to 800 G. When the acceleration is in this range, the washing water can be supplied uniformly over the entire toner cake, and impurities attached to the toner particles can be completely removed, which is preferable.

The supply amount of water used for washing is preferably in a range where washing water does not stay in the rotary cylindrical dehydrator. If the cleaning liquid does not stay, it is preferable because 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 at high speed. Thereafter, the toner cake dehydrated by a 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 a suction pipe or a discharge port, and conveyed to a drying device in the next step. You.
(Washing and regeneration of the filter according to the present invention)
The filter according to the present invention clogged with toner particles and impurities is taken out of the filter and immersed in an ultrasonic bath by a high-pressure jet flow from a high-pressure jet nozzle attached to or inserted into a rotary cylindrical dehydrator. Then, it is cleaned by ultrasonic waves and reused. Since the toner particles and impurities are removed by the washing, no problem occurs even if the toner is reused.

  Next, a rotary 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 illustrating an example of a rotary cylindrical dehydrator.

  The rotary cylindrical dewatering machine shown in FIG. 6 is of a type that discharges a toner cake from below, and includes a main body 301, a basket 302, a basket rotating device 303, a scraping device 304, a liquid supply pipe 305, and a liquid discharge port. 308, cake outlet 310 is attached. The scraping device 304 is provided with a scraper 306, the liquid supply pipe 305 is provided with a liquid injection nozzle 309, and the basket 302 is provided with a removable filter 307 according to the present invention. At the start, a toner particle dispersion is supplied from a liquid supply pipe 305, and the basket 302 is rotated at a high speed to perform solid-liquid separation to form a toner cake on the surface of the filter 307 according to the present invention. The filtrate is discharged from a liquid discharge port 308.

  Thereafter, cleaning water is supplied from a liquid supply pipe 305 to clean the toner cake. The cleaning water for the toner cake 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 is then scraped off by the scraper 306 while rotating the basket 302 at a low speed, and is discharged from the cake discharge port 310.

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

A high-pressure jet cleaning device 603 having 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 a water supply pipe 601 to a high-pressure jet nozzle 602, and high-pressure jet water is jetted from the nozzle to the surface of the filter 307 according to the present invention, and clogged toner particles and impurities Is removed. The jetted cleaning water is discharged from the liquid discharge port 308.

  Next, the toner production 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 coefficient of variation in number-based particle size distribution of 6 to 29%, an average circularity of 0.94 to 0.99, and a variation in circularity. Preferably, the coefficient is 2 to 16%.

  The number average particle diameter, the coefficient of variation of the number-based particle size distribution, the average circularity, and the coefficient of variation of the circularity are calculated using a Coulter Multisizer “SD-2000” (manufactured by Sysmex Corporation) which is an electric resistance type particle size distribution measuring device. ) Can be measured.

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

  The toner according to the present invention is formed by forming toner particles in an aqueous medium or an organic solvent, forming a toner particle dispersion, and then performing solid-liquid separation with a filter having at least two or more meshes to form toner particles. A toner can be obtained by forming a cake, washing and removing impurities from the toner cake, and drying to prepare toner particles, and adding and mixing an external additive as necessary with the toner particles.

  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, and a mixture thereof. . For the production of the toner, a suitable one can be selected from these.

  The method for producing the toner particle dispersion can be produced by a known production method, and specifically includes an emulsion association method, a suspension polymerization method, a dispersion polymerization method, a dissolution suspension method, a continuous emulsion dispersion method, and the like. Although it can be mentioned, it is not particularly limited.

  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.

  Further, 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. Methods can be mentioned.

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

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

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

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

  Each step will be described according to the flow shown in FIG. The toner particle dispersion liquid stocked in the tank 701 is charged into the rotary cylindrical dehydrator 704, and the balance between the supply amount of the toner particle dispersion liquid and the discharge liquid from the discharge port 308 is checked while the rotation of the rotary cylindrical dehydrator 704 is maintained. Continue the operation. After a certain amount of solid-liquid separation is completed, the operation is stopped, and after washing with water and dewatering, the scraper 306 takes out the toner cake from the cake outlet 310. The taken out toner cake is stored in a stock tank 705, and is preferably crushed and then sent to a drying device 706, dried by warm air 715, and then toner particles are collected by a cyclone 707. 708.

  FIG. 9 is a manufacturing flowchart (manufacturing process diagram) illustrating 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 in the decanter 702 and then sent to the liquid preparation tank 703. In the decanter 702, impurities having a lower specific gravity than water are removed in advance. In the adjustment tank 703, the diluting liquid 711 is added, and the toner particles in the concentrated liquid are re-dispersed and adjusted to a concentration suitable for solid-liquid separation, and at the same time, water-soluble impurities are dissolved in the re-dispersed liquid. The redispersed toner particle dispersion is put into a rotary cylindrical dehydrator 704, and thereafter the same operation as in FIG. 8 is performed.

  Examples of the drying device include a flash jet drier, a fluidized bed drier, a spray drier, a vacuum freeze drier, a reduced pressure drier and the like. Two or more of these driers are arranged in series and dried. Is preferred.

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

  Hereinafter, the present invention will be described specifically with reference to examples, but embodiments of the present invention are not limited thereto.

<< Preparation of filter according to the present invention >>
SUS316L metal wire was used as the mesh material. Regarding the weave of the mesh, the mesh forming the solid-liquid separation surface was made by twill weave and plain weave, and the other meshes were made by plain weave. The filter according to the present invention was produced by using a metal wire diameter shown in Table 1 and integrally processing by thermal bonding (sintering). Then, the filter was processed (the diameter of the basket was 1,524 mm and the depth was 1,020 mm) so that it could be mounted on the basket of the rotary cylindrical dehydrator, thereby producing "Filters 1 to 6".

Table 1 shows the eyes of "Filters 1 to 6" according to the present invention prepared as described above and "Filter 7" prepared with a nonwoven fabric (available from Okada Canvas Co., Ltd., air permeability 192 ml / cm ² · min) prepared for comparison. Indicates an opening or the like.

《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, a temperature sensor, a cooling pipe, and a nitrogen introducing device Formula (101)
_{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 in a nitrogen stream.

To this surfactant solution, an initiator solution obtained by dissolving 9.2 g of a polymerization initiator (potassium persulfate: KPS) in 200 g of ion-exchanged water was added, and after adjusting the temperature to 75 ° C., 70.1 g of styrene and 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 the system was heated and stirred at 75 ° C. for 2 hours to perform polymerization (first-stage polymerization). To prepare a latex (a dispersion of resin particles composed of a high molecular weight resin). This is designated as “latex (1H)”.
(2) Formation of intermediate layer (second stage polymerization)
In a flask equipped with a stirrer, a monomer mixture comprising 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-mercaptopropionate was separated. As a mold agent, 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.

Exemplified 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 (formula (101)) in 2700 ml of ion-exchanged water was heated to 98 ° C., and a dispersion of core particles was added to the surfactant solution. After adding 28 g of the above-mentioned "latex (1H)" in terms of solid content, a mechanical dispersing machine having a circulation path "CLEARMIX (CLEARMIX)" (manufactured by M Technic Co., Ltd.) was used. The monomer solution was mixed and dispersed for 8 hours to prepare a dispersion liquid (emulsion liquid) containing emulsified particles (oil droplets) having a dispersion particle diameter of 284 nm.

  Next, to this dispersion liquid (emulsion liquid), an initiator solution obtained by dissolving 5.1 g of a polymerization initiator (KPS) in 240 ml of ion-exchanged water and 750 ml of ion-exchanged water were added. 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 composed of a high molecular weight resin is 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 exemplary compound (19) not surrounded by the latex were observed.
(3) Formation of outer layer (third stage polymerization)
An initiator solution obtained by dissolving 7.4 g of a polymerization initiator (KPS) in 200 ml of ion-exchanged water was added to the “latex (1HM)” obtained as described above, and styrene was added at a temperature of 80 ° C. A monomer mixture composed of 300 g, 95 g of n-butyl acrylate, 15.3 g of methacrylic acid, and 10.4 g of n-octyl-3-mercaptopropionate was added dropwise over 1 hour. After the completion of the dropping, polymerization (third stage polymerization) is carried out by heating and stirring for 2 hours, and then cooled to 28 ° C., and a latex (a central portion composed of a high molecular weight resin, an intermediate layer composed of an intermediate molecular weight resin, A dispersion liquid of composite resin particles having an outer layer made of a molecular weight resin and the intermediate layer containing the exemplified compound (19). This latex is referred to as “latex (1HML)”.

  The composite resin particles constituting the “latex (1HML)” have peak molecular weights (weights) of 138,000, 80,000 and 13,000, and the weight average particle size of the composite resin particles is It was 122 nm.

(Preparation of toner particle dispersion)
59.0 g of an anionic surfactant (sodium dodecyl sulfate) was stirred and dissolved in 1600 ml of ion-exchanged water, and 420.0 g of “CI Pigment Blue 15: 3” was gradually added while stirring this solution. By performing a dispersion treatment using “CLEARMIX” (manufactured by M Technique Co., Ltd.), a “dispersion of colorant particles” was prepared.

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

  Next, an aqueous solution in which 12.1 g of magnesium chloride hexahydrate was dissolved in 1000 ml of ion-exchanged water was added over 10 minutes at 30 ° C. with stirring. After standing for 3 minutes, heating was started, and the temperature of the system was raised to 90 ° C. over 6 to 60 minutes to form associated particles. In this state, the particle size of the associated particles was measured with a “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 exchanged water was added to stop the growth of particles, and the mixture was heated and stirred at a liquid temperature of 98 ° C. for 2 hours as a ripening treatment to complete the fusion of the particles.

  Thereafter, the mixture was cooled to 30 ° C., and the pH was adjusted to 4.5 by adding hydrochloric acid, thereby producing “toner particle dispersion liquid 1”.

<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 dissolved therein was mixed with 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 purging with nitrogen, the contents in the flask were heated in an oil bath until the temperature reached 70 ° C. while stirring, and the emulsion polymerization was continued for 5 hours. As a result, a “resin fine particle dispersion 2” in which resin particles having a volume average particle size of 150 nm, a glass transition temperature of 58 ° C., and a weight average molecular weight of 11,500 were dispersed was obtained. The solid content concentration of this dispersion was 40% by mass.

(Preparation of colorant dispersion)
Coloring agent "CI Pigment Blue 15: 3" 60 parts by mass Nonionic surfactant "Noniphenyl ether" 5 parts by mass Ion exchange water 240 parts by mass After mixing and dissolving the above components, homogenizer "Ultra Turrax T50" (Manufactured by IKA Co., Ltd.) for 10 minutes, and then subjected to dispersion treatment with an ultimateizer to prepare “colorant dispersion liquid 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 mass Cationic surfactant “alkyl ammonium salt” 5 parts by mass Deionized water 240 parts by mass Homogenizer “Ultra Turrax T50” (IKA) in a round stainless steel flask (Manufactured by Co., Ltd.) for 10 minutes, and then subjected to a dispersion treatment with a pressure discharge homogenizer to prepare a "release agent dispersion liquid 2" in which release agent particles having a volume average particle diameter of 550 nm are dispersed.

(Preparation of aggregated particles)
Resin fine particle dispersion 2 234 parts by mass Colorant dispersion 2 30 parts by mass Release agent dispersion 2 40 parts by mass Polyaluminum chloride 1.8 parts by mass Deionized water 600 parts by mass The above components were placed in a 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 holding at 55 ° C. for 30 minutes, it was confirmed that aggregated particles having a D50 of 4.8 μm were formed in the solution. When the temperature of the heating oil bath was further increased and maintained at 56 ° C. for 2 hours, D50 became 5.9 μm. Then, after adding 32 parts by mass of “resin fine particle dispersion 2” to the dispersion containing the aggregated particles, the temperature of the heating oil bath is raised to 55 ° C. and maintained for 30 minutes to prepare “aggregated particles 2”. did. After adding 1 mol / L sodium hydroxide to the dispersion containing the “aggregated particles 2” to adjust the pH of the system to 5.0, the stainless steel flask was closed using a magnetic seal, and stirring was continued. While heating to 95 ° C. and holding for 6 hours to prepare “toner particle dispersion liquid 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 dimethyl sodium 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 It was placed in a polycondensation reactor. The mixture was heated to 190C and the temperature was slowly raised to about 200-202C while collecting methanol by-product in the distillation receiver. Next, the temperature was increased to about 210 ° C. while the pressure was reduced from atmospheric pressure to about 1067 Pa over about 4.5 hours. The product was taken out, and “polyester resin 3” having a glass transition temperature of 53.8 ° C. was prepared.

(Preparation of polyester resin emulsion)
Next, 168 g of the “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% by mass zinc acetate solution. This solution was placed in a reservoir placed on a balance and connected to a pump capable of accurately feeding the zinc acetate solution at 0.01-9.9 ml / min. The amount of zinc acetate required for the association of the emulsion is 10% of the mass of the resin in the emulsion.

  After heating “Emulsion / Dispersion 3” to 56 ° C., the zinc acetate solution was pumped in at 9.9 ml / min to initiate association. Once 60% by weight of the total amount of zinc acetate (205 g of a 5% by weight solution) has been added, the rate of addition of the pump is reduced to 1.1 ml / min and the amount of zinc acetate is equal to 10% by weight of the resin in the emulsion (5%). The addition was continued until the concentration reached 335 g (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 a metal compound of di-t-butylsalicylate, 8 g of a styrene-methacrylic acid copolymer, 20 g of paraffin wax (mp = 70 ° C.) Was heated to 60 ° C., and was uniformly dissolved and dispersed at 12,000 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 a 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 using a “TK homomixer” to disperse tricalcium phosphate. Liquid 4 "was prepared. The “polymerizable monomer composition 4” is added to the “suspension 4”, and the mixture is stirred with a “TK homomixer” at 10,000 rpm for 20 minutes to granulate the “polymerizable monomer composition 4”. did. Then, it reacted at 75-95 degreeC using a reaction apparatus for 5 to 15 hours. 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 100 parts by mass of ethyl acetate A container in which glass beads were added to a dispersion of the above-mentioned material composition was attached to a sand mill disperser. While cooling around the container, the mixture was dispersed in a high-speed stirring mode for 8 hours, and then diluted with ethyl acetate to prepare “Pigment Dispersion Liquid 5” having a pigment concentration of 15% by mass.

(Preparation of dispersion liquid of micronized wax)
Paraffin wax (melting point: 85 ° C.) 15 parts by mass Toluene 85 parts by mass The above-mentioned material was charged into a dispersing machine having a function of circulating a heating medium around a container, equipped with a stirring blade. The temperature was gradually increased while stirring at 83 revolutions per minute, and finally the mixture was stirred for 3 hours while maintaining the temperature at 100 ° C. Next, the mixture was cooled to room temperature at a rate of about 2 ° C. per minute while stirring was continued to precipitate finely divided wax. This wax dispersion was again dispersed 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 wax viscosity was measured and found to be 0.69 μm. The dispersion liquid of the prepared particulate wax was diluted with ethyl acetate so that the mass concentration of the wax became 15% by mass, to prepare a “dispersion liquid 5 of a particulate wax”.

(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 It was confirmed that the polyester resin in the above material composition was sufficiently dissolved. After confirmation, this solution was charged into a homomixer “Ace Homogenizer” (manufactured by Nippon Seiki Co., Ltd.), and stirred at 16,000 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 The aqueous calcium carbonate solution obtained by stirring the above-mentioned material for 4 days in a ball mill was referred to as “aqueous phase (aqueous calcium carbonate solution) 5”. The average particle size of the calcium carbonate was measured using a “laser diffraction / scattering particle size distribution analyzer A-700” (manufactured by Horiba, Ltd.) and found to be about 0.08 μm.

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

(Preparation of spherical particles)
Oil phase 5 55 parts by mass Aqueous phase (aqueous calcium carbonate solution) 515 parts by mass Aqueous phase (aqueous carboxymethyl cellulose solution) 530 parts by mass The above materials were charged into a “colloid mill” (manufactured by Nippon Seiki Co., Ltd.), and the gap interval was 1. Emulsification was performed at 5 mm, 9400 rpm for 40 minutes. Next, the above 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 became 10, and stirring was further continued for 1 hour while stirring in an ultrasonic cleaning tank to prepare “toner particle dispersion liquid 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, and an inlet for raw materials, etc., 0.5 parts by mass of potassium hydroxide and 200 parts by mass of toluene as a solvent were put, and the pressure in the system was reduced to 10 × 10 ⁵ While maintaining the Pa and the temperature at 40 ° C., while stirring, a mixed solution composed 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 change in molecular weight was tracked by terminal group determination, The reaction was terminated when the number average molecular weight reached 7,000. At this time, the total amount of the injected monomers 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 obtained polymer solution under reduced pressure of 4,000 Pa to obtain "polyether resin (A)".

(Synthesis of polyester resin (B) having no ether bond)
In a 5-liter flask equipped with a stirrer, a nitrogen inlet tube, a thermometer, and a rectification 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 reacted by stirring at 240 ° C. under a nitrogen stream. The reaction was terminated when the softening point by the ring and ball method reached 130 ° C., and “polyester resin (B)” was obtained. The obtained “polyester resin (B)” was a light yellow solid and had a weight average molecular weight in terms of polystyrene of 96,000 as measured by GPC.

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 mixed using a twin-screw continuous kneader. The colored resin melt heated to 180 ° C. was transferred to a rotating continuous dispersion apparatus “Cavitron CD1010” (produced by Eurotech) at a rate of 100 g / min. A separately prepared aqueous medium tank is charged with 0.37% by mass of diluted ammonia water obtained by diluting reagent ammonia water with ion-exchanged water, and heating at 150 ° C. with a heat exchanger at a rate of 0.1 liter per minute. Simultaneously with the colored resin melt, transferred to the Cavitron, a rotating speed of the rotor is 7500 rpm, the pressure is 5 × 10 ⁵ Pa, operating temperature of 5 × 10 ⁵ Pa, to obtain a dispersion of colored resin spherical fine particles at a temperature of 160 ℃, After cooling to a temperature of 40 ° C. in 10 seconds, “Toner Particle Dispersion 6” was prepared.

<Preparation of Toner Particle Dispersion 7 (Example of Dispersion Polymerization Method)>
8 parts by mass of polyvinyl butyral (polyvinyl acetate unit: 2% by mass, polyvinyl alcohol unit: 19% by mass, polyvinyl acetal unit: 79% by mass, average degree of polymerization: 630), 300 parts by mass 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 (1 mm in diameter) were added thereto. After stirring with a paint shaker for 6 hours, the glass beads were removed with a mesh to prepare "Dispersion 7".

  While maintaining the polymerization vessel equipped with a mechanical stirrer and an inlet tube for nitrogen bubbling at 15 ° C., 300 parts by mass of the obtained “dispersion liquid 7” and 2,2′-azobisisobutyronitrile were added thereto. 3.6 parts by mass were gradually added to form a polymerization reaction system. At this time, the pigment dispersion ratio 重合 of the polymerization reaction system was 1.01. 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 for 12 hours with stirring. Nitrogen bubbling was continued during the polymerization.

  After completion of the reaction, the mixture was cooled to 20 ° C. while stirring, and decanted to prepare “toner particle dispersion liquid 7”.

  The “toner particle dispersions 1 to 7” produced above were subjected to solid-liquid separation, washing and drying according to the production flow shown in FIG. 9 to obtain toner particles. That is, the solution is concentrated in a decanter to remove impurities having a low specific gravity, and then 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. Thereafter, solid-liquid separation was performed using a rotary cylindrical dehydrator “MARKIII Model No. 60 × 40” (manufactured by Matsumoto Kikai Co., Ltd.) equipped with “Filters 1-1 to 5” described in Table 1 in the order described in Table 2. Thus, a toner cake was formed. The toner cake was washed with water in a rotary cylindrical dehydrator, then the toner cake was scraped off by a scraper inserted in the machine, discharged from the machine and stored in a container. Thereafter, the toner cake was supplied little by little to a “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 prepare “toner particles 1 to 10”. .

<Preparation of toner>
0.8 parts by mass of rutile titanium oxide (volume average particle size = 20 nm, n-decyltrimethoxysilane treatment) was added to 100 parts by mass of the “toner particles 1 to 10” prepared above, and spherical monodispersed silica (sol-gel method) The silica sol obtained in (1) is subjected to HMDS treatment, and dried and pulverized, and 1.8 parts by mass of a particle diameter D50 = 127 nm) are mixed, and a “Henschel mixer” (peripheral speed: 30 m / s) (Mitsui Miike Chemical Co., Ltd.) For 15 minutes. Thereafter, coarse particles were removed using a filter having a mesh size of 45 μm to prepare “Toners 1 to 10”, which were referred to as “Examples 1 to 9” and “Comparative Example 1”.

<< Preparation of developer >>
A ferrite carrier having a volume average particle diameter of 60 μm was mixed with each of the “toners 1 to 10” prepared above to prepare “developers 1 to 10” having a toner concentration of 6%.

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

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

(Density unevenness of halftone image due to toner filming)
The surface of the photoreceptor was visually observed to confirm the presence or absence of toner filming. Then, a halftone image was printed using a gray chart, and density unevenness corresponding to toner filming in the halftone image was visually evaluated.

Evaluation criteria ◎ No toner filming. Good without uneven density ○ No toner filming. Although slight density unevenness is observed, it is good without practical problem. × There is a change in gloss of the photoconductor surface due to toner filming. Density unevenness is noticeable and there is a practical problem (image deletion)
After printing for 2 hours under the condition of high temperature and high humidity (33 ° C., 90% RH), the image flow is smeared along the transfer paper fiber to the 8-point character image of the first printed image. The flow was observed or not with a loupe to evaluate.

Evaluation Criteria ◎ Excellent with no characters that flowed in the image. ○ There are 1-2 characters that flowed in the image per A3 size. There is a problem in practical use due to the clear character flow described above.

(Toner blister)
The print image was formed by adjusting the process so that the toner adhesion amount on the transfer material was 1.6 mg / cm ² . This image was observed using a microscope to determine whether there was a hole having a diameter of about 0.1 to 0.5 mm, that is, a toner blister, and evaluated.

Evaluation criteria ◎ No toner blister at all, no problem ○ 1 to 2 toner blisters per 4 cm ² are present, but there is no practical problem since visual fixation is not enough × 3 or more clarity per 4 cm ² There are practical toner blisters and there is a problem in practical use.
(Carrier contamination)
Carrier contamination was observed at a magnification of 40,000 times using a field-effect scanning electron microscope on the carrier surface after printing 1 million sheets.

Evaluation Criteria ◎ The external additive released from the toner is hardly adhered and excellent. ○ ² to 10 external additives released from the toner are present in the area of 1 μm ² , but the charge amount does not change. Good without practical problems △ There are 11 to 30 external additives detached from the toner in an area of 1 μm ² , and the charge amount tends to decrease by 4 to 10 μC / part by mass as compared with the initial amount, so that practically a little Problem x There are 30 or more external additives detached from the toner in an area of 1 μm ² , the charge amount is reduced by 10 μC / part by mass or more compared to the initial stage, toner scattering and fogging occur, and there is a practical problem.

(Developer durability)
The durability of the developer was evaluated based on the number of prints until the printed image was fogged, the density was reduced, the practicality was lost, and the developer had to be replaced.

Evaluation criteria ◎ Excellent durability with no need to replace developer over 2.5 million prints ○ Good developer exchange with 1 to 2.5 million prints but good durability × Less than 1 million prints require developer replacement and durability Bad. However, printing continued until 1 million prints.

<Amount of cleaning water used>
The amount of washing water used was such that when the toner cake was washed with the rotating cylindrical dehydrator, the amount of washing water required to reduce the electric conductivity of the filtrate to 10 μS / cm was supplied to the rotating cylindrical dehydrator. The evaluation was made based on 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 supplied to the rotating cylindrical dehydrator).

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

Evaluation Criteria ◎ Less than 10 times the amount used is extremely small and excellent ○ 10 to 30 times the amount used is small and good × More than 30 times the amount is large and the productivity is poor, so it is not practical.

<Live-action evaluation>
Table 3 shows the evaluation results of the toner blister, the developer durability, and the amount of cleaning water used.

  As is clear from Table 3, the toners "Examples 1 to 9" obtained by installing the filter according to the present invention were obtained in the following manner. There is no problem in both contamination and developer durability, and a good image can be obtained stably over a long period of time, and the amount of washing water used is small, thus providing an excellent effect.

It is the surface and sectional drawing which show an example of the mesh which concerns on this invention. It is a schematic diagram showing an example of a filter concerning the present invention. FIG. 3 is a schematic diagram illustrating an example of a conventional type filter that performs solid-liquid separation in a state where toner particles enter a filter. It is sectional drawing which shows an example of the filter which concerns on this invention comprised from two meshes. It is sectional drawing which shows an example of the filter which concerns on this invention which consists of five meshes. It is sectional drawing which shows an example of a rotary cylindrical dehydrator. It is sectional drawing which shows an example of the rotary cylindrical dehydrator to which the high pressure jet nozzle which wash | cleans the filter which concerns on this invention is attached. FIG. 2 is a manufacturing flowchart (manufacturing process diagram) illustrating an example of a toner manufacturing method preferably used in the present invention. FIG. 2 is a manufacturing flowchart (manufacturing process diagram) illustrating an example of a toner manufacturing method preferably used according to the present invention.

Explanation of reference numerals

11 Filter According to the Present Invention 12 Toner Cake 13 Toner Particle Dispersion Liquid 14 Mesh Forming Solid-Liquid Separation Surface 15 Reinforcement Mesh 16 Toner Particle 17 Solid-Liquid Separation Surface 18 Droplet 701 Tank 702 Decanter 703 Adjustment Tank 704 Rotating Cylindrical Dehydration Machine 705 Stock tank 706 Drying device 707 Cyclone 708 Toner particle stock tank 715 Hot air 305 Liquid supply pipe 306 Scraper 308 Liquid outlet 310 Cake outlet 601 Cleaning water supply pipe

Claims (3)

A toner production method comprising 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, wherein the filter has a mesh, and the mesh has one side. And the linear members constituting the other one are arranged at regular intervals, and the toner particle dispersion liquid was charged into the filter. A method for producing a toner, characterized in that sometimes a solid-liquid separation surface made of toner particles is formed in pores of the mesh, and solid-liquid separation is performed. The mesh is formed by arranging linear members constituting one side and linear members constituting another side at intervals of 60 to 3000 lines / cm with an interval. 2. The method for producing a toner according to item 1. 3. A method for producing a toner, comprising: concentrating the toner particle dispersion once by a solid-liquid separation operation; and then separating the dispersion dispersed in an aqueous medium again by the method according to claim 1 or 2.

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