JP5181611B2 - Resin particle manufacturing apparatus and resin particle manufacturing method - Google Patents

Description

  The present invention relates to a resin fine particle production apparatus for producing fine particles having a uniform particle size distribution, a resin fine particle production method, and a toner production method obtained thereby.

In recent years, in the electronic printing field, the electrophotographic field, and the like, the market demand for higher resolution is increasing. In order to improve the resolution of images and characters printed on paper using electronic devices such as copiers and printers, it is necessary to use fine resin particles having a narrow particle size distribution as the toner used for printing. For this purpose, a technique for uniformly forming resin used in toner into particles is indispensable. Conventionally, apparatuses for producing resin fine particles used for toner are mainly (1) means for adding a colorant, a pigment, a charge control agent, a release agent, a curing agent, other additives and the like to a resin and kneading; (2) Means for pulverizing the kneaded resin; (3) Means for classifying the pulverized resin. However, kneading the above - milling - in apparatus equipped with the means of the classification, to obtain without classifying the narrow fine resin particles of particle size distribution such that required by the market was difficult. Actually, the average particle diameter of the conventional resin fine particles is about 5 to 8 μm for toner, but it is difficult to obtain resin fine particles having a narrow particle diameter distribution with a good yield with the above-described apparatus. This is because the resin may be excessively pulverized at the time of pulverization, and further, in order to obtain a particle size distribution in a desired range, it is necessary to remove a large amount of particle groups deviating from the desired size at the time of classification.

As a device that compensates for such drawbacks, there is a device that produces resin fine particles by stretching (stretching) a toner material extruded from a kneader into a fiber shape with a roller and cutting it with a cutter (for example, a patent) Reference 1). The apparatus of Patent Document 1 kneads and heats a resin as a toner raw material in a kneader and extrudes the molten resin through a die to form a string. Then, the resin is stretched into a fibrous shape using a roller and then solidified, and the finally produced fibrous resin is cut to obtain a resin powder having a narrow particle size distribution.
However, since the apparatus described in Patent Document 1 stretches the resin extruded from the kneader with a roller to form a fiber, if the resin breaks for some reason during the stretching process, the next cutting process Therefore, it becomes impossible to send the fibrous resin to the resin, and thus the production of the resin fine particles has to be interrupted, or the fiber diameter varies greatly without interruption. This leads to deterioration in production efficiency and becomes a major problem in producing resin fine particles on a commercial scale. If such fine fibers are cut to produce resin fine particles, the particle diameter will vary. Furthermore, in such a method of drawing fibers with a roller, a special production method (for example, a production method of a sea-island type composite fiber using an incompatible two-component polymer blend, a production method of an easy-cut fiber, etc.) is used in combination. Unless otherwise, it is generally difficult to stably produce fine fibers having a diameter of 10 μm or less on a commercial basis. As described above, in the method of Patent Document 1, it is substantially possible to stably and efficiently produce fine fibers using a general resin material (a resin material not optimized for fiberization). It was impossible.

As an apparatus for efficiently producing a fine fibrous resin, there has been a melt blow type spinning die for nonwoven fabric (for example, see Patent Document 2). The spinning die of Patent Document 2 extrudes molten resin from a nozzle while being combined with warm air, and then introduces the extruded resin into cold spinning together with cold air so that the resin is cooled and fiberized. It has become a structure. With the method described in Patent Document 2, since the drawing is performed immediately after the spinning die discharges the raw material resin, even if the resin breaks for some reason, it is difficult for variations to occur. Patent Document 3 attempts to apply the spinning die and apparatus described in Patent Document 2 to an apparatus for processing a toner raw material into a fiber. That is, Patent Document 3 claims an operating condition and an installation condition when the apparatus of Patent Document 2 is applied to toner. That is, in Patent Document 3, based on the apparatus of Patent Document 2, optimum conditions such as a cooling mechanism, arrangement, and operating conditions such as temperature and the amount of air used for stretching are defined (for example, Patent Document 3 No. 0009 section). Further, Patent Document 4 has requirements similar to those described in Patent Document 3 (described in Section 0020 and FIG. 2), and has a static mixer at the rear stage of the kneading process and at the front stage of the miniaturization unit. A manufacturing method and apparatus are defined. Further, Patent Document 5, proposed the shape control using the grinding step and further subsequent step after the processing of the toner material to a fibrous is such.

  The concepts of Patent Documents 1 and 3-5 sharpen the particle size distribution of the final product toner particles by pre-dispersing the raw materials efficiently and uniformly before cutting or grinding. It ’s an excellent idea. However, in both cases, after processing the toner into a fibrous form, the fibrous form is once recovered, and then fine particles are obtained using a secondary device such as grinding or cutting. As a result, the classification process is changed. Spinning process is added to the process and does not contribute to shortening the entire process. Patent Document 6 describes an example of means for directly obtaining toner particles without spraying and drying a solution dissolved and diluted in an organic solvent, without pulverizing it. However, the means of using an organic solvent as in Patent Document 6 has a danger of explosion due to the use of the organic solvent itself, is harmful to the human body, and is a source of VOCs. Therefore it is not friendly to the environment.

  Patent Document 7 describes a technique for improving the efficiency of pulverization and suppressing the generation of fine powder by pulverizing a toner material in which a gaseous substance is finely dispersed in a resin. Although this is an excellent idea, it is a technique that can be regarded as a category of the conventional pulverization classification method, and does not provide a solution for improving the circularity, that is, spheroidization. Patent Document 8 mainly shows a method of finely dispersing a toner material after it is melted and colliding with a high-pressure gas, that is, a method of obtaining fine particles by spraying the melted toner material together with various conditions for spraying. Has been. According to this method, it is possible to produce toner particles directly from the melted raw material without the need for a drying step such as solvent removal, further without the need to crush or cut the toner material, and without classification treatment. Is an excellent feature. However, in this patent document 8, the optimal apparatus form and the means of scale-up are not shown, but there is room for many devices about the apparatus form.

For example, although are base mentioned for example in the 0025 term for forms of supply method for supplying apparatus high-pressure gas suitable for spraying, supply method and apparatus of the molten toner material is sprayed, i.e. requirements for a nozzle or mouthpiece Is not discussed at all. Similarly, the scale-up means is not described. Means for suppressing secondary agglomeration is described in Item 0032. Specific means for improving the degree of circularity of primary particles, which is one of the important requirements for toner particles in recent years, is shown. There was no room for ingenuity. As a result of attempts to improve many of the above-mentioned basic problems, the inventors have improved a production apparatus and production of resin fine particles that can be scaled up without pulverization and can improve the circularity. Devised the law. Furthermore, this has been developed into a toner particle manufacturing apparatus and manufacturing method.

JP-A-6-138704 (FIG. 1) JP-A-2002-371427 (FIG. 2) JP-A-2004-332130 (FIG. 3) Japanese Patent Application No. 2004-290948 (Fig. 2) JP 2006-106236 A Shoko 63-053006 JP-A-2005-004182 JP 2005-258394 A JP2003-10666

Therefore, the present invention has been made in view of the above problems, and the problem is that a production method for efficiently producing resin particles having a circularity of 0.950 or more and a weight average particle diameter (D4) of 10 μm or less, and It is to provide a manufacturing apparatus.
Furthermore, toner particles having a high degree of circularity can be manufactured for toner particles that are a kind of resin fine particles.

  That is, in the present invention, after melting or dissolving a resin or a resin mixture, it is extruded from a fine extrusion nozzle hole, collided with a high-temperature gas flow, and subsequently placed in a high-temperature atmosphere to thereby obtain particles with high circularity. obtain. Particularly in the case of toner particles, a kneaded product of a material containing any of resin, wax, pigment, and CCA is used.

  According to the present invention, it is possible to obtain particles having high circularity with resin fine particles such as electrophotographic toner.

  The best mode for carrying out the present invention will be described below with reference to the drawings. Note that it is easy for a person skilled in the art to make other embodiments by changing or correcting the present invention within the scope of the claims, and these changes and modifications are included in the scope of the claims. The following description is an example of the best mode of the present invention, and does not limit the scope of the claims.

  FIG. 1 is a schematic view showing an example of an entire resin fine particle production apparatus for producing fine particle precursor fibers. By extruding the fluidized resin raw material from the fine nozzle holes, atomization when colliding with the hot gas flow can be promoted. The nozzle hole preferably has a shape such as a fine hole (for example, a circle) or a fine slit. Moreover, after extruding and atomizing from a nozzle hole, resin fine particles with higher circularity can be obtained by exposing to a high temperature atmosphere for a certain period. The process of atomizing a liquid is, for example, after a liquid to which a shearing force is applied is turned into a film, and then the film is divided by the shearing force that is applied subsequently and the surface tension of the liquid itself to form a liquid column or liquid yarn After (fibrosis), it is due to repeated or combination such as breaking into droplets by shearing force and surface tension. In other words, before applying shearing force to the fluid that you want to make into droplets, make the shape as fine as possible in advance, that is, make it a fine liquid column, fiber, fine liquid film, etc. to promote atomization after applying shearing force I can do it. As a means for spraying, a known two-fluid spray nozzle or a known method conforming or derived therefrom can be used as a matter of course.

(High temperature atmosphere)
High circularity, that prescribes the method of producing finely dispersing the resin fine particles such as toner in a hot gas stream.
The Atsushi Ko gas stream by a T1 / 2 or more temperature of the resin, without cooling the resin, it is possible to provide a distributed force to the resin while maintaining the fluid-like (liquid). In consideration of the deterioration of the resin, the temperature of the high-temperature gas flow is desirably 2.5 times or less of the T1 / 2 outflow temperature, more preferably 2 times or less of the T1 / 2 outflow temperature.
The droplet formation process is as described above. Especially in the case of a resin raw material that is cooled and solidified, if it is cooled immediately after atomization, it solidifies while maintaining the shape of the liquid yarn or short fiber in the fission process. End up. Therefore, by holding at a high temperature for a proper time for a proper time, it is possible to promote the spheroidization from the short fiber shape by the surface tension.
That is, the temperature of the high-temperature atmosphere is at least equal to or higher than the Tg of the target resin, preferably equal to or higher than the T1 / 2 outflow temperature defined separately. More preferably, it is desirable that the temperature is not more than twice the T1 / 2 outflow temperature. By doing in this way, the resin raw material in a deformation | transformation process can be softened and the resin fine particle with higher circularity can be obtained. The time of exposure to this high temperature atmosphere needs to be at least 0.1 second, and preferably 0.5 second or longer. However, exposure to a high-temperature atmosphere for an unnecessarily long time is undesirable because it causes deterioration of the resin. Therefore, the time to be exposed to a high temperature atmosphere, Ru der should be both within 10 seconds longer. Also, the high temperature atmosphere, the shape of the resin means a more easily deformable become ambient temperatures for cold atmosphere. In a low-temperature atmosphere where the ease of deformation of the resin does not change, the atomized resin immediately cools and solidifies, and particles with high circularity cannot be obtained. For example, the temperature at which the deformation of the resin becomes easy includes the glass transition point Tg and the like, and the standard of the fluidizing temperature includes Tfb and the like. It has been experimentally confirmed that the temperature of the high-temperature atmosphere is generally at least equal to or higher than the Tg of the target resin, preferably higher than or equal to the outflow start temperature Tfb, and preferably 2.5 times or lower than Tfb. . The outflow start temperature Tfb is also called a flow tester characteristic, and is evaluated as, for example, a softening temperature (Ts), an outflow start temperature (Tfb), a 1/2 method softening point (T1 / 2), and the like. These thermal characteristics can be measured by an appropriately selected method. For example, the thermal characteristics can be obtained from a flow curve measured using an elevated flow tester CFT500 type (manufactured by Shimadzu Corporation).
The measuring method of the outflow start temperature T1 / 2 is as follows.
(About softening point)
The flow curve of this flow tester becomes the data shown in FIG. 2, from which each temperature can be read. In FIG. 2, Ts is the softening temperature, Tfb is the outflow start temperature, and the melting temperature in the 1/2 method corresponds to the softening point of the present invention.
Measurement conditions are as follows.
Load: 30 kg / cm ²
Temperature increase rate: 3.0 ° C / min
Die diameter: 0.50mm
Die length: 1.0mm
(About glass transition point)
Further, the glass transition point (Tg) in the present invention is specifically determined by the following procedure. Using Shimadzu TA-60WS and DSC-60 as measuring devices, the measurement was performed under the following measurement conditions .
Measurement Teijo matter
Sample container: aluminum sample pan (Futaa Ri)
Sample amount: 5m g
Reference: aluminum sample pan (alumina 10m g)
Atmosphere: nitrogen (flow rate of 50ml / mi n)
Temperature soil matter
Open starting temperature: 20 ℃
Heating rate: 10 ℃ / mi n
End temperature: 150 ℃
Retention times: to a
Descending temperature Temperature: 10 ℃ / mi n
End temperature: 20 ℃
Retention times: to a
Heating rate: 10 ℃ / mi n
End temperature: 150 ℃
Results were measured boss was analyzed the Shimadzu data analysis software (TA-60, version 1.52) used. The analysis method is to specify a range of ± 5 ° C centering on the point showing the maximum peak on the lowest temperature side of the DrDSC curve, which is the DSC differential curve of the second temperature rise, and use the peak analysis function of the analysis software to determine the peak temperature. Ask. Next, the maximum endothermic temperature of the DSC curve is determined using the peak analysis function of the analysis software in the range of the peak temperature + 5 ° C. and −5 ° C. in the DSC curve. The temperature shown here corresponds to the Tg of the toner.
In the present invention, when the raw material resin is a mixture of a plurality of resin types, T1 / 2 is the maximum value for T1 / 2 and Tg of the resin occupying 10% or more of the plurality of resin types. It employs the smallest value.
The time during which the resin fine particles are maintained in a temperature atmosphere of Tg or more and T1 / 2 or less of the resin is the distance x from the cooling and solidifying means or a position lower than the desired temperature to the farthest position of the particle generation unit, The theoretical time t for moving. Here, the moving speed v is the moving capacity V (volume, normal conversion) per unit time of the airflow including the particles from the cooling solidification means or the position where the temperature is lower than the desired heat retention temperature to the farthest position of the particle generation unit. , A value obtained by dividing by the maximum area s of the plane on which the particles can exist on a plane perpendicular to the straight line from the cooling solidification means or a position below the desired temperature to the farthest position of the particle generation unit (v = V / S). That is t = x / v Ru der.
(With the grain child diameter)
Evaluation of particle element size, a value measured by a Coulter counter method.
Examples of the particle size distribution measuring apparatus by the Coulter Counter method include Coulter Counter TA-II and Coulter Multisizer II (both manufactured by Coulter Co.). It describes the measurement method is as follows.
Also not a added 0.1~5ml polyoxyethylene alkyl ether as a dispersing agent in the electrolytic solution 100 to 150 ml. Here, the electrolytic solution is a solution prepared by preparing a 1% NaCl aqueous solution using primary sodium chloride. For example, ISOTON-II (manufactured by Coulter) can be used. Here, 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the measurement device is used to measure the volume or number of particles or particles using a 100 μm aperture as the aperture. Calculate distribution and number distribution. From the obtained distribution, the weight average particle diameter (D4) and the number average particle diameter of the particles can be obtained.
As channels, 2.00 to less than 2.52 μm; 2.52 to less than 3.17 μm; 3.17 to less than 4.00 μm; 4.00 to less than 5.04 μm; 5.04 to less than 6.35 μm; 6 Less than 35 to 8.00 μm; less than 8.00 to less than 10.08 μm; less than 10.08 to less than 12.70 μm; less than 12.70 to less than 16.00 μm; less than 16.00 to less than 20.20 μm; less 40 [mu] m; less than 25.40～32.00Myuemu; using 13 channels of less than 32.00～40.30Myuemu, target particle size of less than 2.00μm ~ 40.30μm.
(Attached to the circular shape of)
The measurement of the circle Katachido, flow-type particle image analyzer; measured using a ( "FPIA-2100" manufactured by Sysmex Corporation), analysis software (FPIA-2100
Data Processing Program for FPIA version 00-10) is used. Specifically, 0.1 to 0.5 ml of 10 wt% surfactant (alkylbenzene sulfonate Neogen SC-A; manufactured by Daiichi Kogyo Seiyaku Co., Ltd. ) is added to a glass 100 ml beaker, and fine particles 0.1 to 0.00 are added. Add 5 g and stir with microspatel, then add 80 ml of ion-exchanged water. The obtained dispersion was dispersed for 3 minutes with an ultrasonic disperser (manufactured by Honda Electronics Co., Ltd.), and the dispersion was dispersed with fine particles until a concentration of 5000 to 15000 / μl was obtained using the FPIA-2100. Measure shape and distribution.

(About fine nozzle holes)
By refining the nozzle, the resin fluid can be divided into small portions in advance, and dispersion in the subsequent dispersion process can be promoted, so that finer resin particles can be obtained. It is difficult or impossible to disperse generally viscous materials such as resin fluids to the desired particle size in a one-step process (for example, more high temperature) Gas) and is not economical. By preliminarily dispersing before applying the final dispersion force, it is possible to assist fine dispersion in the subsequent process. The fine nozzle hole is, for example, a small-diameter hole or a slit having a narrow clearance.

Atomization can be promoted by mixing the second substance before introducing the resin raw material into the nozzle hole. Since this resin fine particle manufacturing apparatus has an appropriate mixing device after supplying the second substance, it is possible to uniformly form bubbles in the resin fluid, resulting in a more uniform particle size after dispersion in the latter stage of the process. ing to.
(With the second material)
The second substance is preferably one that lowers the viscosity of the resin fluid (one that can be easily dispersed by mixing) or one that improves separation and dispersibility. For example, a wax having a low melting point and a low viscosity is preferable as a material for reducing the viscosity of the resin fluid. For example, plant waxes such as candelilla wax, carnauba wax, rice wax, mineral waxes such as montan wax and ceresin wax, petroleum waxes such as paraffin wax and petrolatum, synthetic hydrocarbons such as polypropylene and polyethylene, hardened castor oil and Hydrogenated waxes such as hardened castor oil derivatives, fatty acid derivatives such as alcohols, esters, amides, imides, ketones, and metal soaps can be used. In particular, carnauba wax, rice wax, polyethylene, polypropylene, and montan wax are more preferable.

  In another example, a gaseous substance is preferred. For example, by finely mixing air with a resin fluid, a resin fluid containing fine bubbles is obtained. That is, by including many bubbles in the fluid, the resin is preliminarily dispersed in advance, so that atomization in the subsequent stage is further promoted. This pre-dispersion means that the resin is divided into fine segments in advance due to the presence of bubbles, or that the thinning process, which is a spraying process, has progressed to some extent. Among the gaseous substances, carbon dioxide, nitrogen and butane gas are particularly preferable. Butane gas is generally known to be easily dissolved and dispersed in a resin, and is suitable for generating fine bubbles effective for atomization in the subsequent stage. Carbon dioxide and nitrogen are inexpensive and safe, are inert to the resin, and do not adversely affect the resin. More preferably, the gas is supplied in a supercritical state. In particular, supercritical fluids of carbon dioxide and nitrogen are most suitable. For example, in the case of carbon dioxide, it becomes a supercritical state at 31.0 ° C. or more and 72.8 atm or more. Supercritical fluids have the property that their viscosity is small compared to gas, and their diffusion coefficient is close to several hundred times that of liquids. Is widely known to have a uniform bubble diameter (Patent Document 7). In addition, it is known that the bubble film can be thinned to about 2 to 15 μm according to such a bubble formation technique using a supercritical fluid (Patent Document 7). That is, since the resin fluid foamed using the supercritical fluid has already been thinned to about 2 to 15 μm, it is effective as a preliminary dispersion of fine dispersion in the present invention.

(About the mixing mechanism of the second substance)
In particular, when a screw-type mixing device is provided, the dispersion becomes better and the particle diameter becomes uniform. Further, when a static mixer is provided, the dispersion is good and the particle size is uniform. Furthermore, when supercritical fluid is mixed with a static mixer, the operation becomes easier and the device cost is lower than that of a screw-type mixing device. When it is desired to make the apparatus configuration simple and inexpensive, it is preferable to use an extruder that is a kind of screw-type mixer and is generally used for melting and kneading resins. The form of the extruder may be uniaxial or biaxial, or may be other forms such as kneading and dispersing. If you want to facilitate Shinakae, when, etc. that do not want to make extra shearing force to the resin is preferably provided with a stationary mixer in the flow path of the resin fluid leading to the nozzle hole (static mixer). In order to make the particle size after dispersion even more uniform, after mixing with a screw type mixing mechanism, a static mixer may be used to further improve the mixing accuracy and make the bubbles uniform.

  In particular, when mixing a supercritical liquid, it is more preferable to use a static mixer. For example, when mixing a supercritical fluid using a screw-type kneader, complicated pressure control is required as shown in FIG. 3 of Patent Document 9, the operation of the resin fine particle manufacturing apparatus becomes complicated, and the screw The internal design of the kneader is also a special specification requiring modification as described in paragraph 0013 of Patent Document 9, so that the cost is high. When a static mixer is used, the supply pressure of the first substance at the time of coalescence upstream of the static mixer is P1, and the supply pressure of the second substance at the time of coalescence upstream of the static mixer is P2. At this time, it may be simply controlled as P1 = P2. In order to handle gas in a supercritical state, it must be a resin fine particle production apparatus capable of high temperature and pressure. These can use known resin fine particle production apparatuses and means. For example, as a means for increasing the temperature, a known heating means or heat retaining means may be provided. The means for increasing the pressure may also be a known means. Of course, the material and design constituting the resin fine particle manufacturing apparatus must be a material and design that can withstand high temperature and pressure, but this may also be a known one.

By using the gear pump as a means for adjusting the amount of extrusion, fine particles having a more uniform particle diameter can be obtained. As other means for adjusting the amount of extrusion, for example, when using an extruder, there are a method of adjusting by the number of revolutions of the extruder, and a method of adjusting the supply amount of the raw material to the extruder. It is preferable to use it as a means for adjusting the amount. By extrusion amount becomes uniform, always the ratio of the hot gas flow and extrusion rate is constant, the distribution of the particle diameter of atomized particles is uniform.

By providing a plurality of nozzle holes, it is possible to improve ShikaNaru to capacity. By having a unit for supplying hot gas flow for each plurality of nozzle holes, the resin particle production apparatus configuration is simplified, the production cost is cut with reduced. By arranging the nozzle holes in a straight line, the high-temperature gas flow can be efficiently shared with a simpler configuration. It is a form that efficiently shares a high-pressure gas flow with a simpler configuration. By arranging the nozzle holes in an annular shape, the high-temperature gas flow can be efficiently shared with a simpler configuration. It is a form that efficiently shares a hot gas flow with a simpler configuration. The diameter of the nozzle for extruding the resin, by refining the 500μm or less in circle equivalent diameter, previously resin flow body and small fence divided, it is possible to facilitate dispersion in the subsequent distribution process. The nozzle diameter (circular equivalent diameter) is preferably from 100 to 500 μm, and more preferably from 150 to 300 μm. Although it is preferable that the hole diameter of the extrusion nozzle is finer, the finer the pressure, the larger the pressure required for extrusion, or the amount of extrusion decreases if the pressure is constant. Therefore, unnecessarily downsizing is undesirable because it increases the required power and decreases the processing capacity. The pitch (distance) between the nozzle holes is desirably such that the distance d between the centers or the centers of gravity of the nozzle holes is at least twice as large as the circle-converted diameter D of the nozzle holes, more preferably at least three times. More specifically, it is desirably 500 μm or more. Machining below 500 μm involves considerable difficulty and is costly, but even if d is less than 3D, liquid droplets generated by dispersion from a certain nozzle hole are generated from adjacent nozzle holes. The probability of colliding with a drop increases and does not lead to improved energy efficiency. Further, d less than 2D is meaningless because it not only contributes to improvement of energy efficiency but also requires extra processing cost and reduces the strength of the nozzle unit that is an aggregate of nozzle holes. Reducing the strength of the nozzle unit means that the strength of the structure is weakened by narrowing the pitch between nozzles. As a result of the weakened strength, for example, defects such as breakage or cracks in the pitch between the nozzles occur during use.

  By making the nozzle hole into a slit with a narrow clearance, the resin fluid can be thinned in advance, and dispersion in the subsequent dispersion process can be promoted. In addition, the slit shape can be easily scaled up by changing the slit width. The width of the slit is preferably 50 to 400 μm, more preferably 80 μm to 350 μm. The slit width of the extrusion nozzle is preferably finer from the viewpoint of miniaturization. However, the finer the pressure, the greater the pressure required for extrusion, or the constant the pressure reduces the extrusion amount. Therefore, unnecessarily downsizing is undesirable because it increases the required power and decreases the processing capacity.

  By arranging the slits in an annular shape, the slit width can be increased in a more compact device form. Therefore, the processing capability can be improved while maintaining a more compact apparatus configuration. By jetting a high-temperature gas flow from both sides, the shear force can be applied to the extruded resin more uniformly. With a simple apparatus configuration, the processing capacity can be easily improved, and an optimum shape that can efficiently supply a high-temperature gas flow to the extrudate is shown. With a simple apparatus configuration, the processing capacity can be easily improved, and an optimum shape that can efficiently supply a high-temperature gas flow to the extrudate is shown.

  It defines a manufacturing method in which fine resin particles (for example, toner) having a high degree of circularity are finely dispersed in a high-temperature gas flow. By setting the high-temperature gas flow to a temperature equal to or higher than Tfb of the resin and setting the high-temperature atmosphere to equal to or higher than Tg of the resin, the resin raw material can be softened and the circularity can be improved. The temperature of the high-temperature atmosphere is at least equal to or higher than the Tg of the target resin, preferably equal to or higher than the Tfb outflow temperature defined separately, and twice or less than the Tfb outflow temperature. A more preferable production method is defined for a production method in which fine resin particles (for example, toner) having a high degree of circularity are finely dispersed in a high-temperature gas flow.

  The best embodiment for producing resin fine particles will be described. The resin fine particle production apparatus of the flow in FIG. 1 has a flow with specifications satisfying at least the present invention. For example, in order to satisfy the present invention, from the resin fine particle production apparatus of the flow shown in FIG. 1, a main agent feeder having a function of melting and dissolving a resin mixture that is mainly a main agent, a high-temperature air supply unit, and a fine hole It is configured to include at least a spraying device having a nozzle. A so-called extruder is suitable for the main agent supply machine, and for example, a uniaxial or biaxial one is used. In particular, a biaxial one is more suitable. Moreover, a gear pump etc. may be provided as a means to adjust the supply amount of a main ingredient. It is desirable that the melting / dissolving temperature by the main agent feeder can be set to a temperature range of about Tg to twice of Tfb of the resin. For example, in the case of toner, the melting / dissolving temperature by the main agent feeder is preferably 50 to 250 ° C., more preferably 70 to 230 ° C. Furthermore, it is not necessary to set the same temperature at the front, middle, and rear stages of the main agent supply machine, and a temperature gradient may be provided according to the purpose. The main agent supply device can include a mechanism for supplying the second substance in the middle of the supply machine. For example, a feeder A can be provided. The second substance is supplied from a source A having a form suitable for the form of the second substance. The supply source A can supply wax or a substance that is gaseous at normal temperature and pressure. In particular, in order to supply the gas so as to be supercritical, it is desirable to have pressure resistance. As the supply source A, known ones such as a tank, a cylinder, and a hopper can be used. Further, it is desirable to provide a pump A that can cut out a desired amount from the supply source A. Known pumps such as a screw type, gear pump, and diaphragm type can be used. Since the wax is solid at normal temperature and pressure, when supplying the wax, an appropriate superheating mechanism is also required for the supply mechanism of the second substance. The melt viscosity of the wax is desirably 1000 mPa · s or less by heating, and for this purpose, it is desirable to be able to control the temperature range of about 50 to 230 ° C.

A stationary mixer can be provided downstream of the main agent feeder. Further, the stationary mixer can be provided with a feeder B that is a mechanism for supplying the second substance. The second substance is supplied from the supply source B in accordance with the form of the second substance, and it is desirable to further include a pump B that can cut out a desired amount from the supply source B. The requirements and functions of source B are the same as source A. The high temperature air supply unit mainly includes an air supply source and a heater unit for heating the air. Although not shown, it is desirable to provide an air amount adjusting means. As a supply source of air, a known air source can be used in addition to a blower and a compressor. As the heater, in addition to an electric heater and a gas heater, a known heat source can be used, and it is desirable to include a temperature adjusting means. The temperature of the high-temperature air is preferably set to about 3.5 times the Tfb of the resin. For example, in the case of toner, the temperature is preferably 100 to 350 ° C, more preferably 150 to 330 ° C. The spray device includes a nozzle unit having fine nozzle holes, a distribution unit that supplies raw materials to the nozzle holes, and an air unit that supplies high-temperature air. As a means for spraying, a known two-fluid spray nozzle or a known method conforming or derived therefrom can be used as a matter of course. As a more preferable form, what is necessary is just to use what is shown, for example in FIG. The temperature of the spraying device is preferably set to about 3 times the Tfb of the resin. For example, in the case of toner, the temperature is preferably 100 to 300 ° C, more preferably 150 to 250 ° C.
FIG. 6 shows an example of the portion of the nozzle unit to the heat retaining chamber shown in FIG. In addition to the heat insulation chamber and its front and rear devices, as shown in FIG. 6, auxiliary air for controlling the temperature of the heat insulation chamber, cooling air that provides cooling action after the heat insulation chamber, and the like are supplied. Is done.
As shown in FIG. 6, the distance from the heat retaining unit to the cooling unit is, for example, a temperature in the vicinity of the collision of the resin fluid / gas flow or the heat retaining chamber in order to measure that the temperature inside the heat retaining chamber is a desired temperature. A temperature sensor that can measure the temperature near the outlet of the resin can be provided, and the distance from the collision part to the cooling part is guided by the temperature range that is higher than the Tg of the resin measured by the temperature sensor, etc., and the fine particles are kept above Tg Guide the time to be played.

FIG. 3 is an example of the spraying part of the resin fine particle manufacturing apparatus. It consists of nozzle holes arranged in series at equal intervals and gas nozzles positioned in parallel across the nozzle holes. FIG. 4 is also an example of the spraying part of the resin fine particle manufacturing apparatus. Consists of elliptical or roughly rectangular or short slit-shaped nozzle holes arranged in an annular shape at equal intervals, and gas nozzles installed in an annular shape with the same center of gravity as the nozzle hole ring with the nozzle hole in between Ru is.
FIG. 5 is also an example of the spraying part of the resin fine particle manufacturing apparatus. It consists of a nozzle that is a resin flow path formed in a single slit and a gas nozzle that is positioned in parallel across the nozzle.
The arrangement of the nozzles and gas nozzles is not limited to FIGS. As other similar forms, for example, a nozzle that is a resin flow path formed in a single slit shape as shown in FIG. 5, for example, a spray part configured to replace the nozzle hole of FIG. 4, It is also possible to configure an oval shape, a roughly rectangular shape, or a short slit-like nozzle hole as shown in FIG. 4 and a spraying part configured to replace the nozzle hole of FIG. Moreover, in FIGS. 3-5, although the linear form and the annular | circular shaped example were shown, naturally other forms can be taken. Specifically, the nozzle unit may be L-shaped by combining two linear nozzle units, or may be elliptical or rectangular instead of an annular shape. However, in order for each part of each nozzle hole or nozzle slit to exhibit the same ability as each part, a straight line shape or an annular shape is particularly preferable. The spraying device is preferably provided with means for adjusting the resin pressure with respect to the flow path to the nozzle hole, particularly when a supercritical fluid is used. For example, a pressure adjusting unit can be provided in the X part of FIG. . The pressure adjusting means is a known resistor such as a mesh shape or a slit shape, and is installed so as to act equally on each nozzle hole to which the resin is to be distributed.

  1 can maintain a supercritical state even after the gas is mixed with the toner material. For example, pressures between the extruder and the gear pump, between the extruder and the X portion, between the gear pump and the X portion, and the like can be adjusted, so that a high pressure that becomes a supercritical state can be maintained at an arbitrary position. A thermal insulation chamber for maintaining a high-temperature atmosphere of the resin fine particle production apparatus of the present invention can be provided at the subsequent stage of the spraying section. The heat insulation chamber may be a known one, but is particularly preferably one that can arbitrarily control the residence time. The residence time control means may be a known means. For example, as a means for controlling the residence time, for example, means for raising or lowering the amount of air in the chamber, that is, the wind speed, etc., changing the angle of the airflow as a swirling flow, etc. There is a means.

The effects of the present invention will be described below with reference to examples and comparative examples. These are only one aspect of the present invention, and the technical scope of the present invention is not limited thereto.
Raw material: polyester resins 46.75 parts by weight softening point (T1 / 2) 107 ℃ Tg64 ℃
Po Riesuteru resins 38.25 parts by weight softening point (T1 / 2) 124 ℃ T g64 ℃
Po Riesuteru resins 10.00 parts by weight softening point (T1 / 2) 112 ℃ Tg58 ℃
Magenta pigment Dainippon Ink & Chemicals, Inc. TOSHIKI RED 1022 6.0 parts by weight
Polarity control agent Orient Chemical Industries Co., Ltd. BONTRON E-304 0.50 parts by weight
It was premixed over than in a Henschel mixer, after obtaining the raw material A, was carried out comparative experiments to replace parts as required in particulate production apparatus of the flow as shown in FIG. 1 by the following procedure. As the second substance, agent A: carnauba wax and agent B: carbon dioxide gas were used.

Example 1
As the nozzle hole, a 160 μm circular nozzle was used, and a unit having 750 nozzle holes on the left was used as the nozzle unit. The pitch between nozzles is approximately 0.6 mm. The arrangement relationship between the high-temperature air supply port and the nozzle unit is as shown in FIG. 3 , and a slit for high-temperature air is provided so as to sandwich a row of nozzle holes arranged in a straight line. The temperature from the feeder to just before the spray device (temperature of the resin flow path tube wall) was 160 ° C., and the temperature of the spray device (temperature of the tube wall of the resin flow path) was 200 ° C. The high temperature air temperature was 240 ° C. Note that the static mixer of FIG. 1 is replaced with a cylindrical flow path without an intentional resistor inside. Further, the gear pump unit of FIG. 1 was constructed by replacing the simple cylindrical flow path has the name of the resistor. The processing amount of the resin fine particle manufacturing apparatus is the processing amount per nozzle hole where the indicated value of the pressure gauge 2 is 3 MPa under the above-mentioned resin fine particle manufacturing apparatus temperature condition (the processing amount per nozzle hole at this time is 1 unit of raw material throughput). The supply amount of high-temperature air was selected so that the passing rate of the collected particle group through the 400 mesh sieve was 75% under the above-described resin fine particle production apparatus and the temperature condition of the air condition (normal conversion at this time) Air consumption is one unit of air consumption ). In previous SL state, kept chamber temperature was about 200 ° C. (range of 190 to 210 ° C.). The residence time in the heat insulation chamber was theoretically about 2 seconds. Although not shown after passing through the heat insulation chamber, the collected powder is pneumatically transported in a state where the temperature of the collected powder is controlled to 50 ° C. or less (the ambient atmosphere temperature is 40 ° C. or less), collected by a dust collector, and then subjected to sieving, etc. We decided to carry out. Table 1 summarizes the above conditions.
In the comparison of the present case, the one having a 400 mesh sieve passage rate exceeding 60% is of good quality, the weight average diameter D4 after passing through the approximate sieve is less than 10 μm, and the circularity is 0.950 or more. It is a criterion for pass / fail.

Table 2 shows the evaluation results of the products obtained under these conditions.

  Comparative Examples 1 to 3 will be described below. As the nozzle hole, a 160 μm circular nozzle was used, and a unit having 750 nozzle holes on the left was used as the nozzle unit. The pitch between nozzles is approximately 0.6 mm. The arrangement relationship between the high-temperature air supply port and the nozzle unit is as shown in FIG. 3, and a slit for high-temperature air is provided so as to sandwich a row of nozzle holes arranged in a straight line. The temperature from the feeder to just before the spray device (temperature of the resin flow path tube wall) was 160 ° C., and the temperature of the spray device (temperature of the tube wall of the resin flow path) was 200 ° C. The high temperature air temperature is as shown in Table 1. Note that the static mixer of FIG. 1 is replaced with a cylindrical flow path without an intentional resistor inside. The raw material processing amount per nozzle hole was 1 unit. The supply amount of high-temperature air was 1 unit. In this state, the heat retaining chamber was diverted and used as a cooling chamber, and the chamber was cooled so that the temperature in the chamber was less than 60 ° C. Although not shown after passing through the heat insulation chamber, the collected powder is pneumatically transported in a state where the temperature of the collected powder is controlled to 50 ° C. or less (the ambient atmosphere temperature is 40 ° C. or less), collected by a dust collector, and then subjected to sieving, etc. We decided to carry out. Table 1 summarizes the above conditions. Table 2 shows the evaluation results of the products obtained under these conditions. From the results shown in Table 2, it can be seen that when toner is produced with the resin fine particle production apparatus of the present invention, the toner particles can be obtained with higher yield and better.

Examples 2 to 8 and 12 will be described below. As the nozzle hole, a 160 μm circular nozzle was used, and a unit having 750 nozzle holes on the left was used as the nozzle unit. The pitch between nozzles is approximately 0.6 mm. The arrangement relationship between the high-temperature air supply port and the nozzle unit is as shown in FIG. 3, and a slit for high-temperature air is provided so as to sandwich a row of nozzle holes arranged in a straight line. The temperature immediately before the feeder, the static mixer, and the spray device (temperature of the resin flow path tube wall) was 160 ° C., and the temperature of the spray device (temperature of the resin flow path tube wall) was 200 ° C. The high temperature air temperature was 240 ° C. The raw material throughput of the resin fine particle manufacturing apparatus was 1 unit. The supply amount of high-temperature air was 1 unit. In the above state, the temperature in the heat insulation chamber was about 200 ° C. (range 190 to 210 ° C.). The residence time in the heat insulation chamber was about 2 seconds by the method defined in the present invention. Although not shown after passing through the heat insulation chamber, the collected powder is pneumatically transported in a state where the temperature of the collected powder is controlled to 50 ° C. or less (the ambient atmosphere temperature is 40 ° C. or less), collected by a dust collector, and then subjected to sieving, etc. We decided to carry out. Under the above conditions, Table 3 shows a summary of the production methods to which various conditions shown in the present invention were given and improved, and the gear pump, the static mixer, and the pressure adjusting means were attached / removed as necessary.

Table 4 shows the evaluation results of the products obtained under these conditions.

  Example 2 is an example in which a gear pump is installed for adjusting the flow rate of the resin with respect to Condition 1. By making the rotation speed of the gear pump constant, the resin flow rate can be made constant. With respect to Condition 1, the passing rate of the sieve was improved, the average diameter was smaller, the CV value was smaller, and an improvement in the dispersion state was confirmed. Circularity does not change. It seems that the amount of extrusion was stabilized by installing a gear pump and controlling the amount of resin supplied precisely. As a result of stabilizing the extrusion amount, the dispersion state is stabilized, the production amount of coarse particles / ultrafine particles is decreased, and the CV value is decreased. Example 3 is obtained by adding 10 parts by weight of the agent A as a wax using the feeder A to Example 2. Compared to Example 2, the sieve passing rate was improved and the average diameter was also reduced. This is because the resin melt contained more wax in the nozzle hole portion than that of Example 2 and the viscosity of the resin melt during air dispersion was reduced, so that the resin melt became easier to disperse. It can be confirmed from the decrease in the extrusion pressure that the resin viscosity is relatively lowered. In Example 4, 1 part by weight of B agent which is a gaseous substance is added to Example 2. Compared to Example 2, the sieve passing rate was improved and the average diameter was also reduced. This is a result of the molten resin being in a state containing fine bubbles at the nozzle hole, and air dispersion being promoted. In Example 5, B agent is further added in the supercritical state from the state of Example 4, and is mixed with the resin in the supercritical state. It can be seen that the yield after sieving is further improved with respect to Example 4, the average diameter and CV value are slightly reduced, and the particle size distribution is sharpened while the product is refined. This is because the B agent was handled in a supercritical state, and as a result of the improved dispersibility of the B agent in the resin, it was uniformly dispersed in the resin, the foaming became finer and uniform, and each bubble contributed to the air dispersion. This is a result derived by making more uniform. In the sixth embodiment, instead of supplying the B agent from the feeder A as in the fifth embodiment, the B agent is supplied from the feeder B. In Example 6, the B agent was mixed with the resin in the static mixer, but the product was not different from that in Example 5, but the operation of the extruder was easier and more handled. It was easy. Example 7 is an example in which the agent A is introduced into the main agent supply machine together with the raw material A with respect to the example 6. Compared with Example 6, it became more advantageous for dispersion due to the effect of wax blending, and an improvement in yield after passing through the sieve, a reduction in average diameter, and a reduction in CV value were obtained. In Example 8, the raw material A was supplied to the main agent supplying machine, 5 parts by weight of the A agent was supplied from the supplying machine A, and 1 part by weight of the B agent was supplied from the supplying machine B. That is, each compounding amount is the same as in Example 7. The product obtained was the same as in Example 7. From the case of Example 7 or Example 8, it was found that when a supercritical liquid such as B agent was used, a product of at least the same quality could be obtained with a simpler operation if a static mixer was used. Example 12 is an example in which the temperature condition of Example 1 is changed. It can be confirmed that a product having a desired particle size range can be obtained under the temperature condition within the scope of the present invention.

  Example 9 will be described below. The example using the nozzle comprised by the circular tube is shown. As Example 9, an experiment was performed using the nozzle unit having a circular tubular shape as shown in FIG. As the nozzle hole, a 160 μm circular nozzle was used, and a unit having 750 nozzle holes on the left was used as the nozzle unit. The width of the clearance part from which high-temperature air is ejected is the same as that in the first embodiment. The pitch of the nozzle holes is the same as that of the seventh embodiment, and the clearance between the high temperature gas jetting and the distance between the nozzle holes is the same as that of the seventh embodiment. That is, the nozzle of Example 7 is reconfigured as a circular tube as it is. As a result of the experiment, a product similar to that in Example 7 was obtained.

また、この条件で得た製品の評価結果が表６である。

Table 6 shows the evaluation results of the products obtained under these conditions.

  Examples 10 to 11 will be described below. An example using a slit-shaped nozzle is shown. In Example 10, the same resin fine particle manufacturing apparatus as used in Example 1 was used, and only the nozzle unit as shown in FIG. 5 was used. Unlike the first to ninth embodiments, the resin nozzle holes are formed in a slit shape. The slit width of the nozzle hole was 160 μm, and the slit length was 120 mm. The clearance width at which the high-temperature gas is ejected was the same as in Examples 1 and 2, but the slit length was 4/15 relative to Example 1. The main raw material and the second substance were adjusted under the same conditions as in Example 1, and the raw material processing amount of the entire resin fine particle manufacturing apparatus was 750 units (the same processing amount as that in Example 7), and the amount of high-temperature air used was adjusted. However, the amount of high-temperature air used to obtain a sieved product yield similar to that in Example 1 was 0.82 units, the required air amount per unit raw material was reduced, and the energy efficiency was improved. In Example 11, the same nozzle unit as in Example 10 was used, the raw material processing amount was the same and the amount of air used was also the same, and the main raw material and mainly the substance supply were the same as in Example 7 and processed. The obtained product was the same as Condition 9. Table 7 summarizes the above apparatus conditions and the like.

Table 8 shows the evaluation results of the products obtained under these conditions.

It is the schematic which shows an example of the whole apparatus which manufactures fine particle precursor fiber. It is an example of the chart of a flow tester. It is an example of the spraying part of the resin fine particle manufacturing apparatus. It is an example of the spraying part of the resin fine particle manufacturing apparatus. It is an example of the spraying part of the resin fine particle manufacturing apparatus. It is an example of the site | part of a nozzle unit-a heat retention chamber.

Claims (21)

A resin raw material, a resin or a resin mixture containing a resin as a component, a main agent supply mechanism for melting or dissolving, and a nozzle hole for extruding the resin raw material in a melted or dissolved state,
And a means for controlling the amount of extrusion, a mechanism for supplying the second substance to the resin raw material in the previous stage of the nozzle hole, and after the second substance is supplied, the resin raw material and the second substance are mixed, A mixing mechanism for obtaining the second substance mixed resin raw material, and a mechanism for causing the second substance mixed resin raw material flowing out from the nozzle hole to collide with a high-temperature gas flow having a temperature equal to or higher than T1 / 2 of the resin,
Furthermore, it has a structure for holding the resin particles after colliding with the high-temperature gas flow at a temperature equal to or higher than Tg of the resin for a time of 0.1 seconds to 10 seconds, and then has a mechanism for cooling the resin particles,
The second substance is wax and gas, and the wax is supplied from the supply mechanism provided in the main agent supply mechanism to the main agent supply mechanism, and the gas is supercritical from the supply mechanism provided in the mixing mechanism. weight average particle size 10μm or less of the tree fat particle manufacturing apparatus, characterized in that it is supplied in. In the resin particle manufacturing apparatus according to claim 1,
The nozzle hole is tapered toward the tip. Resin particle manufacturing apparatus. In the resin particle manufacturing apparatus according to claim 1 or 2,
The high-temperature gas flow supply port (gas nozzle) is positioned in parallel with the nozzle hole in between. In the resin particle manufacturing apparatus according to any one of claims 1 to 3,
A heat insulation chamber is provided at the rear stage of the nozzle hole,
The resin particle manufacturing apparatus, wherein the cooling mechanism includes a temperature sensor that measures a temperature at which a resin fluid / hot gas flow collides from a heat retaining unit to a cooling unit, or a temperature near an outlet of the heat retaining chamber. . In the resin particle manufacturing apparatus according to claim 4,
The apparatus for producing resin particles, wherein the cooling mechanism supplies auxiliary air for controlling the temperature of the heat retaining chamber or cooling air for cooling the resin particles. In the resin particle manufacturing apparatus according to any one of claims 1 to 5,
A resin particle manufacturing apparatus, wherein the mixing mechanism is a screw having a kneading mechanism. In the resin particle manufacturing apparatus according to any one of claims 1 to 5,
The mixing mechanism is a static mixer. A resin particle manufacturing apparatus, wherein: In the resin particle manufacturing apparatus according to any one of claims 1 to 7,
The gas is carbon dioxide, nitrogen, or butane. In the resin particle manufacturing apparatus according to any one of claims 1 to 8,
An apparatus for producing resin particles, characterized in that the supercritical state is maintained even after the gas supplied in the supercritical state is mixed with at least a resin raw material. In the resin particle manufacturing apparatus according to any one of claims 1 to 9,
The resin particle manufacturing apparatus, wherein the means for controlling the amount of extrusion is a gear pump. In the resin particle manufacturing apparatus according to any one of claims 1 to 10,
A resin particle manufacturing apparatus comprising a plurality of the nozzle holes. In the resin particle manufacturing apparatus according to claim 11,
The apparatus for producing resin particles, wherein the plurality of nozzle holes share a high-temperature gas flow. In the resin particle manufacturing apparatus according to claim 11,
The nozzle holes are arranged linearly. A resin particle manufacturing apparatus, wherein: In the resin particle manufacturing apparatus according to claim 11,
The nozzle holes are arranged in an annular shape. In the resin particle manufacturing apparatus according to any one of claims 11 to 14,
The diameter of the nozzle hole in terms of a circle is 100 to 500 μm. In the resin particle manufacturing apparatus according to any one of claims 11 to 15,
The nozzle hole has a slit shape with a width of 50 to 400 μm. In the resin particle manufacturing apparatus according to claim 16,
The said slit is cyclic | annular. The resin particle manufacturing apparatus characterized by the above-mentioned. In the resin particle manufacturing apparatus according to any one of claims 1 to 3,
The gas particle supply device is installed on both sides of the nozzle hole as a center. In the resin particle manufacturing apparatus according to claim 13 or 14,
The diameter of the nozzle hole in terms of a circle is 100 to 500 μm, and the gas flow supply port is installed on both sides of the nozzle hole as a center. The process according to claim 1 to 19 or the resin particle production apparatus weight average particle size 10μm or less of the tree fat particles you characterized by producing in the description. In the manufacturing method of the resin particle according to claim 20,
A method for producing resin particles, wherein the resin particles are toner.

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