JP2004258614A - Method for manufacturing toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a toner by which a favorable image can stably be formed without causing toner blister on a toner image. <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 used for the solid-liquid separation is regenerated by the effect of ultrasonic waves. <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 in which a filter for solid-liquid separation of a toner particle dispersion is regenerated by the action of ultrasonic waves.

  In recent years, instead of toner manufactured by mechanical pulverization, toner manufactured by wet granulation has attracted attention because it is advantageous for reducing the particle size, sharpening the particle size distribution, and introducing a large amount of release agent. ing. As a specific method for producing a toner produced by wet granulation, there are an emulsion association method, a suspension polymerization method, a dispersion polymerization method, and a solution suspension method using a separately polycondensed polyester or the like.

  A polymerized toner by an emulsion association method of forming toner particles through a polymerization process in an aqueous medium has a small particle size and a sharp particle size distribution because the particle size and shape of the toner particles can be controlled in the manufacturing process, 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 for a toner having such a uniform particle size and shape, for example, a minute dot image of 1200 dpi (dpi represents the number of dots per inch (2.54 cm)) is obtained. The adoption of digital type image forming for image formation is being actively studied.

  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 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, it is necessary to thoroughly wash the toner particles so that these impurities do not remain.

  For the purpose of removing water-soluble impurities and soluble impurities from the toner particles, while separating the solid particles and the aqueous medium by centrifugation, supply of the washing water until the electric conductivity of the separated liquid (filtrate) becomes a specific value or less. A technology for cleaning the toner particles by performing the cleaning is disclosed (for example, see Patent Document 2).

Further, there is disclosed a technique in which toner particles from which an aqueous medium has been removed are put into a container provided with a stirring blade and a filter, and a washing liquid is added and stirred, and then the toner particles are filtered under pressure to remove impurities. (For example, see Patent Document 3).
JP 2000-214629 A JP 2000-292976 A JP 2001-249490 A

  However, during the solid-liquid separation of the toner particle dispersion, the filter is clogged. That is, when the solid-liquid separation of the toner particle dispersion liquid is performed, insoluble salts, insoluble impurities such as a colorant and a release agent released from the toner particles, toner fine particles and the like are clogged in the filter to cause clogging. . Then, it was necessary to replace the filter with a new filter every time the filter clogged, which required a man-hour and cost for replacement, and it was difficult to carry out the solid-liquid separation of the toner particle dispersion liquid quickly, efficiently and at low cost. .

  In particular, when the filtration of the toner particles is continued under pressure as in Patent Document 3, the clogging of the filter is promoted, and it becomes difficult to remove impurities from the surface of the toner particles in a short cycle. It cannot be removed.

  In fact, without considering the clogging of the filter, when an image is formed using the toner obtained through the reproduction method disclosed in the above-mentioned patent document, a white granular “toner blister” is formed in a high density portion on the image. The image defect called what was called. An image defect called a toner blister is a phenomenon in which impurities remaining in toner particles become hydrates, and when the hydrates are turned into water vapor by heating in the fixing process and are discharged from the toner image as bubbles, the toner image layer is destroyed. As a result, it is presumed that a white granular image defect is generated in a high density portion on the image.

  As described above, a technique for solid-liquid separation of the toner particle dispersion liquid while completely removing impurities from the toner particles has not been established.

  Therefore, solid-liquid separation of the toner particle dispersion can be performed while removing impurities from the surface of the toner particles, and stable toner images are not generated on the toner image when the image is formed using the produced toner. An object of the present invention is to provide a toner manufacturing method for manufacturing a toner capable of forming an image.

  The present invention has been proposed in view of the above problems, and performs solid-liquid separation of a toner particle dispersion by removing impurities from the toner particle surface using a filter, and appropriately regenerates a filter that performs solid-liquid separation. An object of the present invention is to provide a toner manufacturing method for manufacturing a toner capable of forming a stable image without generating toner blisters when an image is formed with the toner thus manufactured.

The object of the present invention is achieved by employing the following configuration.
(Claim 1)
In a toner production method having a step of performing solid-liquid separation using a filter on a toner particle dispersion containing toner particles formed in an aqueous medium or in an organic solvent, the filter used for the solid-liquid separation includes an ultrasonic filter. A method for producing a toner, comprising a step of reproducing by an action.
(Claim 2)
The method according to claim 1, wherein the solid-liquid separation is performed using a filter that forms a solid-liquid separation surface.
(Claim 3)
3. The method according to claim 1, wherein in the step of performing the solid-liquid separation, clogging of the filter is detected by a detecting unit, and the filter is regenerated based on the detection result. 4.

  The toner manufacturing method of the present invention enables a filter for performing solid-liquid separation of a toner particle dispersion liquid to be regenerated by the action of ultrasonic waves, thereby enabling the filter to be used repeatedly. Significantly improved efficiency.

  Further, when an image is formed using the toner produced by the toner production method according to the present invention, it has become possible to stably produce a toner that forms a high-quality toner image without image defects.

  Furthermore, in the present invention, it has been found that the organic water-insoluble matter adhering to the filter which caused the filter to be clogged can be removed by applying ultrasonic vibration to the filter. In this way, clogging is eliminated by the action of ultrasonic vibration, so conventional methods have to consider the effects of environmental pollution, such as using a large amount of detergent and dissolving and removing impurities by chemical action. This is a different idea from the filter regeneration technology.

  The present invention relates to a toner manufacturing method including a step of removing clogging of a filter by regenerating the filter by applying ultrasonic vibration to a filter for solid-liquid separation of a toner particle dispersion.

  The inventors of the present invention have studied a technique of efficiently separating the formed toner particles from the toner particle dispersion liquid without leaving impurities on the surface of the toner particles. In the toner cake, solid-liquid separation is performed by securing microscopic voids of a micron order enough for moisture to sufficiently flow between toner particles, and stable toner without causing image defects due to toner blisters. Is an important condition in getting Even when such fine voids are formed between the toner particles, it is important that water is always flowing through the voids during solid-liquid separation, and foreign matter clogs the eyes of the filter. We studied to develop a state that does not cause such a factor that inhibits the flow of water in the void.

  That is, the present invention has found that clogging of a filter, which is a factor inhibiting stable solid-liquid separation, is eliminated by applying ultrasonic waves to the filter.

  In the present invention, a solid-liquid separation device provided with a detection means for detecting the clogged state of the filter is used, and when the detection result of the detection means reaches a specific value, ultrasonic waves are applied to the filter to adhere to the filter. It has been found that a stable toner free from image defects due to toner blisters can be obtained by removing water-insoluble matters (for example, toner fine particles and impurities).

  As described above, the present invention enables the solid-liquid separation of the toner particle dispersion liquid while always detecting the clogged state of the filter, so that the microparticles between the toner particles in the toner cake formed during the solid-liquid separation can be formed. The cleaning water was allowed to pass homogeneously without staying in the minute gaps of the order.

  Hereinafter, the present invention will be described in detail.

  First, the solid-liquid separation of the toner particle dispersion expressed in the present invention will be described.

  FIG. 1 is a schematic diagram showing a state in which toner particles in a toner cake are stacked in a coarse state, and there is a gap between the toner particles in which washing water flows uniformly.

  In FIG. 1, reference numeral 11 denotes a filter, 12 denotes a toner cake, 13 denotes a toner particle dispersion, 16 denotes toner particles, 17 denotes a solid-liquid separation surface, and 18 denotes droplets.

  The toner cake 12 shown in FIG. 1 is formed by stacking toner particles 16 in a coarse state, and forms a gap between the toner particles in which washing water flows uniformly. When an image is formed with toner obtained from the toner cake formed in this state, a good toner image without toner blisters is formed.

  On the other hand, FIG. 2 is a schematic view showing a state in which toner particles are stacked in a dense state in a toner cake to form an aggregate, and no gap is formed between the toner particles so that the washing water can flow uniformly. .

In FIG. 2, 11 is a filter, 12 is a toner cake, 13 is a toner particle dispersion, 16 is a toner particle, 17 is a solid-liquid separation surface, 18 is a droplet, and 19 is an aggregate.

  In the toner cake 12 shown in FIG. 2, the toner particles 16 are stacked in a dense state to form an aggregate, and since there is no gap between the toner particles so that the washing water flows uniformly, the toner cake 12 adheres to the surface of the toner particles. Impurities are difficult to wash with washing water. When an image is formed with toner obtained from the toner cake formed in this state, an image defect due to a toner blister easily occurs, and it is difficult to obtain a good toner image.

  According to the toner manufacturing method of the present invention, the clogging state of the filter is detected by various detecting means so that the solid-liquid separation can be performed in a state where the washing water flows well in the gap between the toner particles as shown in FIG. By regenerating the filter based on the above, stable solid-liquid separation can be performed.

  The toner manufacturing method of the present invention for realizing such a smooth solid-liquid separation is such that the filter clogged by the solid-liquid separation operation of the toner particle dispersion liquid is clogged by regenerating by the action of ultrasonic waves. The toner fine particles and impurities thus removed are efficiently removed, and the above-described solid-liquid separation is stably continued.

  The present invention is characterized in that the filter is regenerated by the action of ultrasonic waves. However, it is preferable to regenerate the filter by detecting the clogged state of the filter.

  Since the filter clogging state cannot be observed by taking out the filter from the solid-liquid separator during the solid-liquid separation, it is preferable to infer the clogged state from the value detected by the indirect detection means.

  By detecting the clogged state of the filter and regenerating the filter based on the detection result, it is possible to maintain good solid-liquid separation ability.

  Since the clogging state of the filter is detected, and the filter is regenerated by the action of ultrasonic cleaning and cleaning of the toner cake based on the detection result, the amount of cleaning water used for cleaning the toner cake is small and can be performed in a short time, and In addition, the amount of regenerated water required for regenerating the filter is small and can be performed in a short time. As a result, the time operation rate of solid-liquid separation can be increased, and the number of times the filter can be used repeatedly can be increased.

  Here, the time operation rate of solid-liquid separation is a value obtained by the following equation, and the larger the value of the time operation rate of solid-liquid separation, the better the productivity and the more preferable.

Formula Time operation rate (%) of solid separation = solid-liquid separation time / (solid-liquid separation time + toner cake washing time + filter regeneration time) × 100
FIG. 3 is a diagram illustrating an example of the toner manufacturing process according to the present invention.

  The process of FIG. 3 will be described in order.

  1. An instruction is given to send the toner particle dispersion to the solid-liquid separation device.

  2. The toner particle dispersion is subjected to solid-liquid separation by a solid-liquid separation device, and separated into a toner cake and a separated liquid.

  3. The clogging detection means detects the clogging, and if the detected value is within the control value, instructs to feed the toner particle dispersion.

  4. When the detected value exceeds the control value, the feeding of the toner particle dispersion is stopped, and an instruction to wash the toner cake is issued.

  5. Instructs to discharge the toner cake.

  6. Instruct the regeneration of the filter by the signal of the completion of discharge.

  Return to step 7.1 and instruct to continue toner production.

  As the “solid-liquid separation device” used in the present invention, a device that can be provided with a detection means (device) and can be provided with an ultrasonic vibrator for regenerating a filter is used. Specific examples include a filter press, a pressurized leaf-shaped dehydrator, a pressurized nutche, a rotary cylindrical dehydrator, a rotary disk dehydrator, and the like. Among these, a rotary cylindrical dehydrator as shown in FIG. This is preferable because the device can easily install the detecting device and the ultrasonic vibrator, and can efficiently reproduce the filter.

  The "filter" according to the present invention has a solid-liquid separating ability from the toner particle dispersion liquid to the toner particles and the dispersion liquid, and is capable of removing toner fine particles and impurities clogged in the filter and being reusable. If it is not particularly limited, specifically, a nonwoven fabric, a filter having a mesh in which linear members are regularly arranged and woven, a filter having a screen in which linear members are arranged in parallel, a filter having a porous member A filter having a mesh formed by regularly arranging linear members from the viewpoint of ease of reproduction, durability, handling, etc. preferable.

  The “filter that forms a solid-liquid separation surface” according to the present invention is a filter in which toner particles are filled in the eyes of the filter so that the toner particles can form a solid-liquid separation surface.

  As the `` method of forming a solid-liquid separation surface '' according to the present invention, when solid-liquid separation is performed using a filter that forms a solid-liquid separation surface, toner particles are filled in the eyes of the filter, and toner particles A solid-liquid separation surface is formed, and 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. In this method, an impurity component is washed away from the surface of the toner particles of the toner cake together with the liquid component.

  Here, the “solid-liquid separation surface” is a surface on which a liquid component is removed from the toner particle dispersion liquid. As described above, in the present invention, the toner particles form a filling state in the eyes of the filter, and Surfaces that support each other in a state.

Next, using a rotary cylindrical dehydrator equipped with a flow meter capable of detecting the discharge amount of the separated liquid subjected to solid-liquid separation, the toner particles are solid-liquid separated from the toner particle dispersion to form a toner cake, and the toner cake is washed. A method for scraping and discharging a toner cake and a method for regenerating a filter will be described.
(Formation of toner cake by solid-liquid separation of toner particles from toner particle dispersion, washing of toner cake)
In the present invention, the toner particle dispersion is solid-liquid separated using a filter to form a toner cake, and the toner cake is washed with washing water or alcohol.

  Specifically, a toner particle dispersion containing toner particles is supplied into a tank of a rotary cylindrical dehydrator equipped with a filter, and by operating this centrifugal separator, toner particles are deposited on the surface of the filter from the toner particles. To form a toner cake.

  During the operation of the rotary cylindrical dehydrator, the discharge amount of the separated liquid is checked by a flow meter, and when the discharge amount falls below a predetermined value, the supply of the toner particle dispersion liquid is stopped and the solid-liquid separation is interrupted. I do.

  Next, washing water is supplied into the tank of the rotary cylindrical dehydrator to wash the discharged liquid until the electric conductivity of the discharged liquid becomes 50 μS / cm or less. The electric conductivity of the discharged liquid can be measured by a normal electric conductivity meter, and examples of such an electric conductivity meter include “CM-10P” (manufactured by Toa Denpa Kogyo Co., Ltd.).

  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 separated liquid (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 704. 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 704 shown in FIG. 7 at high speed. Thereafter, the toner cake dehydrated by the scraper attached to or inserted into the rotary cylindrical dehydrator is scraped off the filter surface, discharged from the suction pipe or the discharge port, and conveyed to the drying device 706 in the next step.
(Play filter)
The present invention is characterized in that a filter clogged with toner fine particles and impurities is reproduced by the action of ultrasonic waves. The method of reproducing the clogged filter by the action of ultrasonic waves is a method of putting an ultrasonic vibrator into the apparatus for performing solid-liquid separation, or a method of removing the filter from the apparatus for performing solid-liquid separation and an ultrasonic generator. The method may be performed within the apparatus, but a method in which an ultrasonic vibrator is inserted into the apparatus is preferable from the viewpoint of performing reproduction in a short time and efficiently.

  Next, a method for regenerating a clogged filter by solid-liquid separation by introducing an ultrasonic vibrator into a rotary cylindrical dehydrator will be described.

  Examples of the ultrasonic generator used in the present invention include an oscillator W-115T manufactured by Honda Electronics, an oscillator manufactured by Branson, a GSC1200I manufactured by Ginsen, and an ultrasonic generator (Middle Wave, A commercially available ultrasonic generator such as a horn type or a mega wave TM jet) is used, and a vibrator portion of the ultrasonic generator is put into a rotary cylindrical dehydrator.

  The conditions for reproducing the filter by ultrasonic waves are preferably a frequency of 10 kHz to 2 MHz and an output of 500 to 5000 W.

  Here, the detection means (device) for detecting the clogged state of the filter will be described.

  In the present invention, the clogging state of the filter is detected by the indirect detection means, and the actual clogging state is estimated from the detection result to determine the timing at which the regeneration is performed.

  Although the indirect detection means is not particularly limited, the following method can be specifically mentioned.

1. 1. The amount of discharged separated liquid per unit time separated and discharged by the filter is detected by a flow meter or the like. 2. Dehydration pressure of the separated liquid discharged from the filter is detected by a pressure sensor or the like. The liquid level of the toner particle dispersion of the solid-liquid separation device is detected by an optical sensor, an ultrasonic sensor, a microwave sensor, or the like. Here, the "separation liquid" is used to disperse the toner particles to a concentration suitable for solid-liquid separation. The liquid may be a dispersion liquid (for example, an aqueous medium or an organic solvent) of the toner particle dispersion liquid used for forming the toner particles, or may be a newly added diluent liquid, and is not particularly limited.

  Next, a control chart for producing toner particles by using a rotary cylindrical dehydrator equipped with a “flow meter” for detecting the discharge amount of the separated liquid as a detecting means will be described.

  FIG. 4 is a management chart of toner particle production showing an example when the discharge amount of the separated liquid is managed by a flow meter.

  The vertical axis of the chart indicates the discharge amount of the separated liquid per unit time, and the horizontal axis indicates the time.

  When the toner particle dispersion is supplied to the rotary cylindrical dehydrator and solid-liquid separation is performed, the discharge amount of the separated liquid subjected to solid-liquid separation is detected by a flow meter. As the toner particle dispersion is supplied and solid-liquid separation is continued, filter clogging gradually progresses, and the amount of discharge decreases. When the discharge amount falls below a predetermined value, the supply of the toner particle dispersion is stopped and the solid-liquid separation is interrupted. The toner cake formed by solid-liquid separation is washed, dehydrated, and discharged from the rotary cylindrical dehydrator. The filters are then regenerated and reused. By repeating this operation, toner particles can be produced.

  FIG. 5 shows a rotary cylinder type dehydrator in which a “flow meter” for detecting the discharge amount of the separated liquid is installed as a detecting device for detecting the clogged state of the filter, and a filter regenerating device is provided with an ultrasonic vibrator. It is sectional drawing which shows an example.

  In FIG. 5, reference numeral 704 denotes a rotary cylindrical dehydrator, 301 denotes a main body, 302 denotes a basket, 303 denotes a basket rotating device, 304 a toner cake washing device, 305 denotes a supply pipe for liquid (toner particle dispersion liquid, toner cake washing water), 306 is an ultrasonic generator, 307 is an ultrasonic vibrator, 308 is an outlet for the separated liquid, 309 is a filter, 310 is a toner cake outlet, and 401 is a flow meter.

  The rotary cylindrical dehydrator shown in FIG. 5 is of a type that discharges a toner cake from the lower part. A main body 301 includes a basket 302, a basket rotating device 303, a scraping device (not shown), a toner cake cleaning device 304, A sound wave oscillator 306, a separation liquid outlet 308, and a toner cake outlet 310 are attached. A liquid supply pipe is attached to the toner cake cleaning device, an ultrasonic oscillator 307 of the ultrasonic oscillator 306 is put into the basket 302, and a removable filter 309 is attached to the basket 302.

  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, thereby forming a toner cake on the surface of the filter 309. The separated liquid (filtrate) is discharged from the separated liquid outlet 308. The discharge amount of the filtrate (dispersion liquid) per unit time discharged from the separation liquid discharge port 308 is measured using the flow meter 401, and when the flow rate exceeds the control value, the supply of the toner particle dispersion liquid is stopped. Then, the solid-liquid separation is interrupted.

  Thereafter, in order to wash the toner cake, washing water is supplied from a liquid supply pipe 305. The washing water for the toner cake is discharged from the drain 308 of the separated liquid.

  The washed toner cake is dehydrated by rotating the basket 302 at a high speed, then scraped off by a scraper at a low speed and discharged from the toner cake outlet 310.

  After the toner cake is scraped off, the main body 301 is filled with water, and the filter 309 is regenerated by the action of ultrasonic waves from the ultrasonic vibrator 307 or the action of cavitation generated by ultrasonic waves. Thereafter, the filter is dried, and the process returns to the first step, and the feeding of the toner particle dispersion is restarted.

  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 liquid, and then performing solid-liquid separation with a filter to form a toner cake composed of toner particles, and washing the toner cake. The toner particles are prepared by removing impurities and drying to prepare toner particles, and adding an external additive to the toner particles as necessary.

  Next, a method for producing the toner particle dispersion will be described.

  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.

  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.

  Examples of the organic solvent include toluene, xylene, and a mixture thereof, but are not particularly limited.

  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》
The following filter was prepared as a filter to be set in the rotary cylindrical dehydrator.

1. SUS316L metal wire was used as a material for the filter mesh having a mesh made of a linear member. The mesh of the filter forming the solid-liquid separation surface was made of twill tatami weave, and the other mesh was made of plain weave. The wire diameters shown in Table 1 were used. After the produced mesh was integrally processed by thermal bonding, it was processed to a size that could be mounted on a basket, thereby producing "Filter 1".

2. Filter having a screen made of wedge wire A filter having a screen in which an inverted triangular wire rod (made of SUS) is welded to a raindrop-shaped support rod (made of SUS) so that a slit-shaped gap (corresponding to an opening) becomes 10 μm. 2 "was produced.

3. A commercially available non-woven fabric (manufactured by Okada Canvas Co., Ltd., air permeability 192 ml / cm ² · min) “Filter 3” was prepared.

  Table 1 shows the apertures of “Filters 1 to 3” prepared and prepared as described above, the wire diameter used for each mesh, and the configuration thereof.

<< Preparation 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 mass average particle diameter of the composite resin particles is It was 122 nm.

(Preparation of Toner Particle Dispersion 1)
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 particles>
The toner particles were obtained by using an apparatus in which a “filter” described in Table 1 was set in a rotary cylindrical dehydrator “MARKIII model number 60 × 40” (manufactured by Matsumoto Kikai Co., Ltd.) equipped with the flow meter of FIG. The “toner particle dispersion 1” produced above was solid-liquid separated to form a toner cake. The solid-liquid separation is interrupted when the set reference value shown in Table 2 is exceeded, the formed toner cake is washed in a rotary cylindrical dehydrator, then scraped off with a scraper inserted in the machine, and 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, thereby producing “toner particles 1 to 4”. .

《Regeneration of filter》
After discharging the toner cake, the ultrasonic vibrator “Mega Wave TM Jet” (manufactured by Ultrasonic Industry Co., Ltd.) is put into the basket of the main body filled with water of the rotary cylindrical dehydrator, and operated for 10 minutes. The filter was regenerated by removing toner particles and impurities clogged in the filter. The ultrasonic conditions at this time were a frequency of 15 kHz and an output of 900 W. Thereafter, hot air was blown from the nozzle of the cleaning device used for cleaning the toner cake to dry the entire rotary cylindrical dehydrator, and the regeneration of the filter was completed.

  The life of the filter (the number of times the filter can be repeatedly used (n times)) is defined as the point in time when the discharge at the start of solid-liquid separation becomes 70% of the discharge of a new filter.

<Preparation of toner>
0.8 parts by mass of rutile-type titanium oxide (volume average particle size = 20 nm, n-decyltrimethoxysilane treatment) was added to 100 parts by mass of the “toner particles 1 to 4” prepared above, and spherical monodisperse 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 4”, which were referred to as “Examples 1 to 3” and “Comparative Example 1”.

<< Preparation of developer >>
A ferrite carrier having a volume average particle size of 60 μm was mixed with each of the “toners 1 to 4” produced above to prepare “developers 1 to 4” having a toner concentration of 6%.

  Table 2 shows the filters used for solid-liquid separation, the method of regenerating the filters, the set standard discharge amount at which solid-liquid separation is interrupted, the discharge amount at the start of a new filter, the discharge amount at the time of interruption, and the start of the one-time regeneration filter. And the discharge amount at the start of the 70-time regeneration filter.

《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).

(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 blisters at all and no problem ○ 1 to 2 toner blisters exist per 4 cm ^2, but there is no practical problem due to the fact that they cannot be recognized by visual observation △ 3 to 5 toners per 4 cm ² There is a toner blister, but there is no practical problem because it cannot be recognized by visual observation. There are 6 or more clear toner blisters per 4 cm ^{2 and} there is a practical problem.

(Resolution variation between lots)
Images of 20 batches of each toner were printed in the same carrier and image forming apparatus in the 600 dpi (dpi represents the number of dots per inch (2.54 cm)) mode, and the lot-to-lot variation in resolution was evaluated.

  8.0 black-and-white patterns per mm were printed in the main scanning direction, and a peak value of the sample frequency analysis with respect to the reference peak value of the frequency analysis of one line per mm was determined in image density, and evaluated according to the following evaluation criteria.

Evaluation criteria バ ッ チ Excellent without any batch whose ratio to the reference peak value is less than 50%.

○ One or more batches have a ratio of less than 50% to the reference peak value, and two or less batches have a good ratio of 40 to 50%. △ One or more batches have a ratio of less than 50% to the reference peak value. 8 batches or less that are present and 40 to 50% are barely practicable. × One or more batches whose ratio to the reference peak value is less than 50% exist, and 8 or more batches that are 40 to 50% exist. However, there is a practical problem.

<Hourly operation rate of solid-liquid separator>
The time during which the solid-liquid separator is operated to produce toner particles is the sum of the time during which the device is stopped due to toner washing and filter regeneration and the time during which the solid-liquid separator is operated to produce toner particles. The value divided by was evaluated as the time availability of the solid-liquid separator.

Evaluation criteria ◎ The productivity is excellent when the hourly operating rate is 90% or more. ○ The productivity is good when the hourly operating rate is 71 to 89%. × The operating rate is 70% or less and the productivity is poor.

  Table 3 shows the evaluation results of the toner blister, the lot-to-lot variation in resolution, the amount of washing water used, the time availability of the solid-liquid separator, and the life of the filter.

  As is clear from Table 3, the toners “Examples 1 to 4” produced by the toner production method of the present invention have less toner blisters and have a lot-to-lot variation in resolution than “Comparative Example 1”. And a good image can be obtained stably for a long period of time, and the time operation rate of solid-liquid separation is high, which is an excellent effect.

FIG. 4 is a schematic diagram illustrating a state in which toner particles in a toner cake are stacked in a coarse state, and there is a gap between the toner particles in which washing water flows uniformly. FIG. 4 is a schematic diagram showing a state in which toner particles are stacked in a dense state in a toner cake to form an aggregate, and no gap is formed between the toner particles so that the washing water can flow uniformly. FIG. 3 is a diagram illustrating an example of a toner manufacturing process according to the present invention. 6 is a management chart of toner particle production, showing an example when a discharge amount of a separated liquid is managed by a flow meter. A cross-section showing an example of a rotating cylindrical dehydrator equipped with a "flow meter" that detects the amount of separated liquid discharged as a detection device that detects the clogged state of the filter, and that is equipped with an ultrasonic vibrator as a filter regeneration device FIG.

Explanation of reference numerals

301 main body 302 basket 303 basket rotating device 304 toner cake cleaning device 305 liquid supply pipe 306 ultrasonic generator 307 ultrasonic transducer 308 separated liquid discharge port 309 filter 310 toner cake discharge port 401 flow meter 601 high pressure water supply pipe 704 Rotating cylindrical dehydrator

Claims (3)

In a toner production method having a step of performing solid-liquid separation using a filter on a toner particle dispersion containing toner particles formed in an aqueous medium or in an organic solvent, the filter used for the solid-liquid separation includes an ultrasonic filter. A method for producing a toner, comprising a step of reproducing by an action. The method according to claim 1, wherein the solid-liquid separation is performed using a filter that forms a solid-liquid separation surface. 3. The method according to claim 1, wherein in the step of performing the solid-liquid separation, clogging of the filter is detected by a detecting unit, and the filter is regenerated based on the detection result. 4.

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