JP2021137725A - Dispersion fluid production device - Google Patents

Abstract

To provide a dispersion fluid production device capable of maintaining a function in which, a preparation ratio amount and an assumed composition ratio of a functional coat can be made substantially match, and producing particle dispersion fluid having no particle aggregation.SOLUTION: A dispersion fluid production device MS for producing particle dispersion fluid in which particles having a prescribed particle diameter or smaller are dispersed in a dispersant, comprises: cracking means 1 for cracking particle aggregate in the dispersant, in which the particle aggregate being obtained by aggregation of the particles whose particle diameter exceeds a prescribed particle diameter in the dispersant; classifying means 2 for classifying particles and particle aggregate in the dispersant; and a circulation line 3 for circulating the dispersant including any one of the particles and particle aggregate, between the cracking means and classifying means, in which a circulation line directed to the classifying means from the cracking means is a primary line 31, and a circulation line directed to the cracking means from the classifying means is a secondary line 32, and the classifying means is configured to return the dispersant including the particle aggregate, to the secondary line.SELECTED DRAWING: Figure 1

Description

The present invention relates to a dispersion liquid manufacturing apparatus for producing a particle dispersion liquid in which particles having a predetermined particle size or smaller are dispersed in a dispersion medium.

Conventionally, there are those in which a so-called functional coating film is formed on the surface of a base material such as a plastic film, and in the formation (coating) of such a functional coating film, predetermined particles selected according to the function are formed. A particle dispersion liquid in which particles having a diameter or smaller are dispersed in a dispersion medium is used. Here, when a predetermined amount (charged ratio amount) of particles is mixed in the dispersion medium according to the assumed composition ratio of the functional coating film, the particles aggregate in the dispersion medium and exceed the predetermined particle size. May form. Since the presence of such particle agglomerates causes deterioration of the performance of the functional coating film such as adhesive strength and breaking strength, it is important how to obtain a particle dispersion liquid without particle agglomerates.

A dispersion liquid producing apparatus for producing the particle dispersion liquid is known, for example, in Patent Document 1. This includes a stirring means (crushing means) for crushing particle aggregates in the dispersion medium, a circulation line for circulating the dispersion medium, and a filter provided on the circulation line. Then, by capturing and removing the particle agglomerates in the dispersion medium with a filter, a particle dispersion liquid without the particle agglomerates can be obtained. However, if the particle agglomerates are captured and removed as in the above-mentioned conventional example, the amount of particles contained in the particle dispersion liquid becomes smaller than the charged amount, and the charged ratio amount and the functional coating film There is a problem that the composition ratio does not match the assumed composition ratio.

Japanese Patent No. 3635170

In view of the above points, the present invention can produce a particle dispersion liquid without particle agglomerates without impairing the function of being able to substantially match the charged ratio amount and the assumed composition ratio of the functional coating film. The subject is to provide a dispersion liquid manufacturing apparatus.

In order to solve the above problems, the dispersion liquid manufacturing apparatus of the present invention for producing a particle dispersion in which particles having a predetermined particle size or smaller are dispersed in a dispersion medium has the particles that exceed a predetermined particle size in the dispersion medium and aggregate. A crushing means for crushing the particle agglomerates in the dispersion medium, a classification means for classifying the particles in the dispersion medium and the particle agglomerates, and the crushing means. A circulation line for circulating a dispersion medium containing at least one of the particles and the particle agglomerates is provided between the crushing means and the classification means, and a circulation line from the crushing means to the classification means is referred to as a primary line. The circulation line from the classification means to the crushing means is a secondary line, and the classification means is configured to return the dispersion medium containing the particle agglomerates to the secondary line. In this case, it is preferable to further provide a bypass line for returning the dispersion medium containing the particles from the rating means to the primary line.

According to the above, only the dispersion medium (dispersion unachieved liquid) containing the particle agglomerates requiring further crushing is returned to the crushing means from the classification means via the secondary line, and the particle coagulation in the dispersion medium. Further crushing is applied to the aggregate. After that, it is sent to the rating means by the primary line. Then, after being merged with the dispersion medium (dispersion achievement liquid) containing the particles that do not require further crushing, which is sent from the classification means, it is sent to the classification means again. By repeating this operation until the dispersion medium returned from the classification means to the crushing means does not contain particle aggregates, a particle dispersion liquid in which particles having a predetermined particle size or smaller are dispersed in the dispersion medium can be obtained. As described above, in the present invention, the crushing treatment of the particle agglomerates can be efficiently carried out by adopting the structure in which the classification means is provided and only the undispersed liquid is returned to the crushing means. At this time, since the obtained particle dispersion liquid does not capture and remove the particle agglomerates as in the above-mentioned conventional example, the amount of particles contained in the particle dispersion liquid can be made equal to the charged amount, and the result is As a result, when a functional coating film is formed using the obtained particle dispersion liquid, the assumed composition ratio of the functional coating film can be substantially matched with the charged ratio amount.

The schematic diagram which shows the dispersion liquid production apparatus of embodiment of this invention.

Hereinafter, the dispersion liquid production apparatus according to the embodiment of the present invention will be described with reference to the drawings, exemplifying an example of producing a particle dispersion liquid in which particles having a predetermined particle size or smaller are dispersed in a dispersion medium.

With reference to FIG. 1, the MS is a dispersion liquid manufacturing apparatus, and the dispersion liquid manufacturing apparatus MS regards particles that exceed a predetermined particle size in a dispersion medium as particle agglomerates and is contained in the dispersion medium. The crushing means 1 for crushing the particle agglomerates is provided. As the crushing means 1, for example, at least one selected from a high-speed stirrer, a rotor-stator type disperser, a jet mill, a bead mill, and the like can be used alone or in combination. Hereinafter, a case where a high-speed stirrer is used as the crushing means 1 will be described as an example. The high-speed stirrer 1 is provided in a stirring tank 11 having a predetermined volume with an open upper portion, a discharge port 12a and a supply port 12b provided on the bottom wall and side walls of the stirring tank 11, and a stirring tank 11. A high-speed stirring blade 13 that can be rotated by an external drive unit is provided. The particles and the dispersion medium are charged into the stirring tank 11 at a predetermined charging ratio, or the particles are mixed (prepared) with the dispersion medium at a predetermined charging amount in advance. Further, the stirring tank 11 is provided with a temperature control means (not shown) so that the temperature of the dispersion medium can be controlled to a predetermined temperature while the high-speed stirring blade 13 is rotated to crush the particle agglomerates. .. Since a known crushing means including the high-speed stirrer 1 can be used, further detailed description thereof will be omitted.

In the dispersion liquid production apparatus MS, at least one of the particles and the particle aggregate is used between the classification means 2 for classifying the particles and the particle aggregates in the dispersion medium and the high-speed stirrer 1 and the classification means 2. A circulation line 3 for circulating the containing dispersion medium is further provided. As the classification means 2, for example, a free vortex type or a forced vortex type wet classifier can be used, and since such a wet classifier is known, further detailed description thereof will be omitted. The circulation line 3 has a primary line 31 from the high-speed stirrer 1 to the wet classifier 2, and a secondary line 32 from the wet classifier 2 to the high-speed stirrer 1. Further has a bypass line 33 for connecting the above. A liquid feeding pump 4 is provided on the downstream side of the confluence of the primary line 31 with the bypass line 33. Since a known pump 4 can be used, detailed description thereof will be omitted here. By adopting such a configuration, the wet classifier 2 can return the dispersion medium (dispersion unachieved liquid) containing the classified particle aggregates to the secondary line 32, while dispersing the classified particles. The medium (dispersion achieved liquid) can be returned to the primary line 31 via the bypass line 33. Further, a branch line 34 having a valve 35 interposed therebetween is connected to the downstream side of the junction of the primary line 31 with the bypass line 33, and by opening the valve 35, particles are dispersed via the branch line 34. The liquid is ready to be obtained. Hereinafter, a method for producing a particle dispersion liquid for producing a particle dispersion liquid will be described using the dispersion liquid production apparatus MS.

First, particles are mixed in advance in a dispersion medium at a predetermined charging ratio amount and charged into the stirring tank 11 of the high-speed stirrer 1 (or, the dispersion medium and particles are charged into the stirring tank 11 at a predetermined charging ratio amount. In this case, the particles are mixed in the dispersion medium in the stirring tank 11). As the dispersion medium, a resin solution (polymer solution) obtained by diluting the resin with a solvent can be used. Examples of the resin include acrylic resins such as (meth) acrylic acid ester polymers and (meth) acrylic acid ester copolymers, vinyl chloride / vinyl acetate copolymers, vinyl chloride, vinyl chloride / acrylonitrile copolymers, and ethylene. -Vinyl-based copolymers such as vinyl acetate copolymers and polyolefin resins such as polyethylene and polypropylene can be exemplified. Examples of the solvent include organic solvents such as methanol, ethanol, methyl ethyl ketone, acetone, cyclohexanone, benzene, toluene, xylene, and ethyl acetate. The particles can be appropriately selected according to the function of the functional coating film, and include inorganic particles (inorganic fillers) such as silica, titanium dioxide, alumina, barium sulfate, calcium carbonate, and glass, polymethyl methacrylate, and the like. At least one selected from organic particles such as polycarbonate, polystyrene, polyvinyl chloride, silicone, and melamine-silica composite resin can be used alone or in combination. Further, the particles may be those in which very small primary particles such as fumed silica aggregate to form secondary particles.

When the particles are mixed in the dispersion medium in this way, the particles are not uniformly dispersed in the dispersion medium immediately after mixing, but the particles are aggregated in the dispersion medium to form particle agglomerates exceeding a predetermined particle size. Sometimes. In order to crush the particle agglomerates into particles, the high-speed stirring blade 13 in the stirring tank 11 is rotated at a predetermined rotation speed (for example, 1000 to 20000 rpm). At the same time, when the pump 4 is operated, the dispersion medium containing the particle aggregates and particles discharged from the discharge port 12a of the stirring tank 11 is sent to the wet classifier 2 via the primary line 31 and is wet. The classifier 2 classifies the particles contained in the dispersion medium and the particle aggregates.

Since the particle agglomerates classified by the wet classifier 2 require further crushing, the dispersion medium (dispersion unachieved liquid) containing the particle agglomerates is returned to the high-speed stirrer 1 via the secondary line 32. , The particle agglomerates in the dispersion medium are further crushed and then sent to the primary line 31. Then, after merging with the dispersion liquid (dispersion achievement liquid) containing the particles that do not require further crushing, which is sent from the wet classifier 2 via the bypass line 33, the wet classifier 2 is sent. By repeating this operation until the dispersion medium returned from the wet classifier 2 to the high-speed stirrer 1 does not contain particle agglomerates (that is, until the end point of the crushing process), particles having a predetermined particle size or less are dispersed. Particles dispersed in the medium are obtained. The end point of the crushing treatment is determined when the dispersion medium is sampled from the stirring tank 11, the particle size distribution of the sampled material is measured using a known particle size distribution meter, and the measured value is within the permissible range. be able to. When it is determined that the crushing process is completed, the valve 35 can be opened and the particle dispersion liquid can be obtained from the branch line 34.

As described above, in the present embodiment, by adopting a configuration in which the wet classifier 2 is provided and only the undispersed liquid is returned to the high-speed stirrer 1, the particle agglomerate can be efficiently crushed. At this time, since the obtained particle dispersion liquid does not capture and remove the particle agglomerates as in the above-mentioned conventional example, the amount of particles contained in the particle dispersion liquid can be made equal to the charged ratio amount. As a result, when a functional coating film is formed using the obtained particle dispersion liquid, the assumed composition ratio of the functional coating film can be substantially matched with the charged ratio amount.

Next, examples of the present invention will be described. Table 1 shows some of the liquid conditions, the classifier conditions, and the results in each Example and each Comparative Example described later.

(Example 1)
In Example 1, 80 parts by mass of 2-ethylhexyl acrylate, 5 parts by mass of acrylic acid, and 15 parts by mass of n-butyl methacrylate are copolymerized by a solution polymerization method to obtain a (meth) acrylic acid ester as an acrylic resin. A polymer was obtained, and this (meth) acrylic acid ester polymer was diluted with methyl ethyl ketone to obtain a resin solution as a dispersion medium. Silica (manufactured by Denka, trade name "SFP-30M") having a predetermined primary particle size (0.6 μm) as particles was mixed with this resin solution. The amount of the resin solution mixed with silica was 2000 ml, the content of the (meth) acrylic acid ester polymer with respect to the entire resin solution was 21% by mass, and the content of silica was 15% by mass. The resin solution mixed with silica in this way was put into the tank of a rotor-stator type disperser (manufactured by Primix Corporation, trade name "Neomixer") as the crushing means 1. Immediately after charging, the silica in the resin solution forms silica aggregates (the median diameter D50 at this time is 5.4 μm), and the rotor-stator type disperser (hereinafter referred to as “disperser”) 1 is rotated at a predetermined number of revolutions (hereinafter referred to as “disperser”). The silica aggregate was crushed by rotating at 10000 rpm). During the crushing process, the temperature of the resin solution in the tank was maintained at 20 ° C. using a temperature control facility. At the same time, silica and silica aggregates contained in the resin solution were classified by a wet classifier (manufactured by Satake Chemical Machinery Co., Ltd., trade name "SATAKE i Classifier") as the classifying means 2. The rotation speed of the wet classifier 2 was 3000 rpm, and the liquid treatment amount (total amount of resin solution flowing out from the wet classifier 2) was 10 L / hr. The resin solution (dispersion unachieved liquid) containing the silica aggregates classified by the wet classifier 2 was returned to the disperser 1 via the secondary line 32. The resin solution is periodically sampled from the inside of the wet disperser 2, and the particle size distribution is measured by a laser diffraction type particle size distribution meter (manufactured by Malvern, trade name "Mastersizer 3000"), and all the measured particle sizes are measured. When the time (dispersion achievement time) at which the target particle size was 0.8 μm (primary particle size 0.6 μm + 0.2 μm) or less was determined, the dispersion achievement time was 20 minutes (the median diameter d50 at this time was 0.62 μm), it was found that the silica aggregate can be efficiently crushed by the disperser 1. An isocyanate compound (manufactured by Toyochem Co., Ltd., trade name "BHS-8515") as a cross-linking agent is added to the particle dispersion obtained as described above, and a plastic film is used to obtain a dry film thickness of 5 μm by a roll knife method. A functional coating film was obtained by coating on the surface of. When the coated surface of the obtained functional coating film was visually observed, there were no agglomerate defects, and when the cross section of this functional coating film was observed with an optical microscope (magnification 100 times), it was larger than the film thickness. It was confirmed that there were no aggregates and that the particle dispersion had no silica aggregates. Further, 10 g of the particle dispersion obtained in Example 1 was heated in an electric furnace at a temperature of 800 ° C. for 24 hours to separate ash, and the weight of this ash (final particle weight) was determined. The final particle weight (1.5067 g) obtained and the initial particle weight (1.5068 g) obtained from the silica content (charge ratio) were substituted into the following equation to obtain the particle reduction rate, and the target value was obtained. It was less than 0.01% (shown as 0% in Table 1), which was smaller than (1%), and it was confirmed that the amount of particles contained in the particle dispersion could be made equal to the charged ratio amount.
Particle reduction rate (%) = (initial particle weight-final particle weight) / initial particle weight x 100

(Example 2)
In Example 2, the same resin solution as in Example 1 is used, and the amount of silica to be mixed is changed to make the silica content with respect to the entire resin solution 20% by mass, which is the same as in Example 1. A particle dispersion was obtained by the above method. Although the silica content was higher than that of Example 1, the dispersion achievement time was 20 minutes, which was the same as that of Example 1. The median diameter D50 of the silica aggregate immediately after charging was 6.1 μm, and the median diameter d50 of silica when dispersion was achieved was 0.62 μm, which were substantially the same values as in Example 1 above. Further, when a functional coating film was obtained in the same manner as in Example 1 and the coated surface and cross section thereof were observed, it was confirmed that the particle dispersion liquid did not contain silica aggregates. Further, when the particle reduction rate was obtained in the same manner as in Example 1, it was 0.01%, which was smaller than the target value (0.1%), and the amount of particles contained in the particle dispersion was the amount of the charged ratio. It was confirmed that it can be made equivalent to.

(Example 3)
In Example 3, the same resin solution as in Example 1 was used, and the amount of silica to be mixed was changed so that the silica content with respect to the entire resin solution was 30% by mass. A particle dispersion was obtained in the same manner as in the above. Since the silica content was further increased as compared with Example 2 (the median diameter D50 of the silica aggregate immediately after charging was 6.6 μm), the dispersion achievement time was 30 minutes, which was longer than that of Examples 1 and 2. The median diameter d50 of silica at the time of achieving dispersion was 0.63 μm, which was the same as in Example 1 above. Further, when a functional coating film was obtained in the same manner as in Example 1 and the coated surface and cross section thereof were observed, it was confirmed that the particle dispersion liquid did not contain silica aggregates. Further, when the particle reduction rate was obtained in the same manner as in Example 1, it was 0.01%, which was smaller than the target value (0.1%), and the amount of particles contained in the particle dispersion was the amount of the charged ratio. It was confirmed that it can be made equivalent to.

(Example 4)
In Example 4, the particles are barium sulfate having a predetermined primary particle size (0.6 μm) (manufactured by Sakai Chemical Industry Co., Ltd., trade name “BARIACE-55”) (the content of barium sulfate in the entire resin solution is 15). A particle dispersion was obtained in the same manner as in Example 1 above, except that the liquid treatment amount of the wet classifier 2 was 20 L / hr. The dispersion achievement time (the time when the particle size of all the particles became 0.8 μm or less, which is the primary particle size + 0.2 μm) was 20 minutes, which was the same as in Example 1 above. Immediately after charging, barium sulfate in the resin solution forms barium sulfate aggregates, and the median diameter D50 at this time is 5.8 μm, and the median diameter d50 of barium sulfate when dispersion is achieved is 0.60 μm. The values were substantially the same as those in Example 1 above. Further, when a functional coating film was obtained in the same manner as in Example 1 and the coated surface and cross section were observed, it was confirmed that the particle dispersion liquid did not contain barium sulfate aggregates. Further, when the particle reduction rate was determined in the same manner as in Example 1, it was less than 0.01%, which was smaller than the target value (0.1%), and the amount of particles contained in the particle dispersion was set as the charging ratio. It was confirmed that it can be equal to the amount.

(Example 5)
In Example 5, the particles are made of alumina having a predetermined primary particle size (0.7 μm) (the content of alumina in the entire resin solution is 15% by mass), and the liquid treatment amount of the wet classifier 2 is 20 L / hr. A particle dispersion was obtained in the same manner as in Example 1 above, except for the above points. The dispersion achievement time (the time when the particle size of all the particles became 0.9 μm or less, which is the primary particle size + 0.2 μm) was 20 minutes, which was the same as in Example 1 above. Immediately after charging, the alumina in the resin solution formed an alumina aggregate, and the median diameter D50 at this time was 6.1 μm, and the median diameter d50 of the alumina when dispersion was achieved was 0.74 μm. Further, when a functional coating film was obtained in the same manner as in Example 1 and the coated surface and cross section thereof were observed, it was confirmed that the particle dispersion liquid did not contain alumina aggregates. Further, when the particle reduction rate was obtained in the same manner as in Example 1, it was 0.01%, which was smaller than the target value (0.1%), and the amount of particles contained in the particle dispersion was the amount of the charged ratio. It was confirmed that it can be made equivalent to.

(Example 6)
In Example 6, the particles are silicone fine particles having a predetermined primary particle size (1 μm or less) (manufactured by Tanac Co., Ltd., trade name “XC99-A8808”) (the content of the silicone fine particles in the entire resin solution is 15% by mass). A particle dispersion was obtained in the same manner as in Example 1 above, except that the rotation speed of the wet classifier 2 was 500 rpm and the liquid treatment amount was 20 L / hr. The dispersion achievement time (the time when the particle size of all the particles became 1.2 μm or less, which is the primary particle size + 0.2 μm) was 20 minutes, which was the same as in Example 1 above. Immediately after charging, the silicone in the resin solution formed a silicone aggregate, and the median diameter D50 at this time was 3.8 μm, and the median diameter d50 of the silicone fine particles at the time of achieving dispersion was 1 μm. Further, when a functional coating film was obtained in the same manner as in Example 1 and the coated surface and cross section thereof were observed, it was confirmed that the particle dispersion liquid did not contain silicone aggregates. Further, when the particle reduction rate was obtained in the same manner as in Example 1, it was 0.01%, which was smaller than the target value (0.1%), and the amount of particles contained in the particle dispersion was the amount of the charged ratio. It was confirmed that it can be made equivalent to.

(Example 7)
In Example 7, the particles are melamine resin / silica composite particles (manufactured by Nissan Chemical Industries, Ltd., trade name "Optobeads 500SL") having a predetermined primary particle size (0.5 μm) (melamine resin / silica for the entire resin solution). A particle dispersion was obtained in the same manner as in Example 1 above, except that the content of the composite particles was 15% by mass), the rotation speed of the wet classifier 2 was 500 rpm, and the liquid treatment amount was 20 L / hr. .. The dispersion achievement time (the time when the particle size of all the particles became 0.7 μm or less, which is the primary particle size + 0.2 μm) was 20 minutes, which was the same as in Example 1 above. Immediately after charging, the melamine resin / silica composite particles in the resin solution form aggregates, and the median diameter D50 at this time is 2.9 μm, and the median diameter d50 of the melamine resin / silica composite particles when dispersion is achieved is It was 0.51 μm. Further, when a functional coating film was obtained in the same manner as in Example 1 and the coated surface and cross section thereof were observed, it was confirmed that the particle dispersion liquid had no agglomerates. Further, when the particle reduction rate was obtained in the same manner as in Example 1, it was 0.02%, which was smaller than the target value (0.1%), and the amount of particles contained in the particle dispersion was set as the charging ratio. It was confirmed that it can be made equivalent to.

(Example 8)
In Example 8, the particles were fumed silica (manufactured by Nippon Aerosil Co., Ltd., trade name “AEROSIL® R972”) (the content of fumed silica in the entire resin solution was 5% by mass). , A particle dispersion was obtained in the same manner as in Example 1 above. The particle size distribution was measured in the same manner as in Example 1 above, and the time (dispersion achievement time) at which all the measured particle sizes were equal to or less than the target particle size (10 μm) was 20 minutes (the median diameter d50 at this time was 8 μm), it was found that it can be efficiently crushed by a disperser. A plurality of the fumed silica before charging is aggregated to form an agglomerate, and the median diameter D50 of the fumed silica aggregate in the resin solution immediately after charging is an order of magnitude larger than that of Examples 1 to 7 above. It was 15 μm. Further, when a functional coating film was obtained in the same manner as in Example 1 and the coated surface and cross section thereof were observed, the fumed silica aggregates as observed immediately after the injection were not present in the particle dispersion liquid. Was confirmed. Further, when the particle reduction rate was obtained in the same manner as in Example 1, it was 0.08%, which was smaller than the target value (0.1%), and the amount of particles contained in the particle dispersion was set as the charging ratio. It was confirmed that it can be made equivalent to.

Next, a comparative example with respect to the above embodiment will be described.

(Comparative Example 1)
In Comparative Example 1, a particle dispersion was obtained in the same manner as in Example 1 above, except that the classifier was not used (that is, the dispersion treatment was performed using only the disperser 1). The dispersion achievement time was 90 minutes, which was 4.5 times that of Example 1. It is considered that this is because the silica agglomerates cannot be efficiently crushed by the disperser because the classifier is not used. The median diameter D50 of the silica aggregate at the time of charging was 5.4 μm, and the median diameter d50 of the silica at the time of achieving dispersion was 0.67 μm, which were substantially the same values as in Example 1 above.

(Comparative Example 2)
In Comparative Example 2, a particle dispersion was obtained in the same manner as in Example 4 except that a classifier was not used as in Comparative Example 1. The dispersion achievement time is 100 minutes, which is five times that of Example 4, which is considered to be because the barium sulfate aggregate cannot be efficiently crushed by the disperser as in Comparative Example 1. The median diameter D50 of the barium sulfate aggregate at the time of charging was 5.8 μm, and the median diameter d50 of the barium sulfate aggregate at the time of achieving dispersion was 0.63 μm, which were substantially the same values as in Example 4 above.

(Comparative Example 3)
In Comparative Example 3, a particle dispersion was obtained in the same manner as in Example 5 except that a classifier was not used as in Comparative Example 1. The dispersion achievement time is 100 minutes, which is five times that of Example 5, which is considered to be because the alumina agglomerates cannot be efficiently crushed by the disperser as in Comparative Example 1. The median diameter D50 of the alumina aggregate at the time of charging was 6.1 μm, and the median diameter d50 of the alumina at the time of achieving dispersion was 0.72 μm, which were substantially the same values as in Example 5 above.

(Comparative Example 4)
In Comparative Example 4, a particle dispersion was obtained in the same manner as in Example 6 except that a classifier was not used as in Comparative Example 1. The dispersion achievement time is 120 minutes, which is 6 times that of Example 6, which is considered to be because the silicone aggregate cannot be efficiently crushed by the disperser as in Comparative Example 1. The median diameter D50 of the silicone aggregate at the time of charging was 3.8 μm, and the median diameter d50 of the silicone fine particles at the time of achieving dispersion was 1 μm, which were substantially the same values as in Example 6 above.

(Comparative Example 5)
In Comparative Example 5, a particle dispersion was obtained in the same manner as in Example 7 except that a classifier was not used as in Comparative Example 1. The dispersion achievement time is 120 minutes, which is 6 times that of Example 7, which is considered to be because the agglomerates cannot be efficiently crushed by the disperser as in Comparative Example 1. The median diameter D50 of the aggregate at the time of charging was 2.9 μm, and the median diameter d50 of the melamine resin / silica composite particles at the time of achieving dispersion was 0.53 μm, which were substantially the same values as in Example 7 above.

(Comparative Example 6)
In Comparative Example 6, a particle dispersion was obtained in the same manner as in Example 8 except that a classifier was not used as in Comparative Example 1. The dispersion achievement time is 150 minutes, which is 7.5 times that of Example 8, which is considered to be because the agglomerates cannot be efficiently crushed by the disperser as in Comparative Example 1. The median diameter D50 of the aggregate at the time of charging was 15 μm, and the median diameter d50 of the fumed silica at the time of achieving dispersion was 8 μm, which were substantially the same values as in Example 8 above.

According to the above Examples and Comparative Examples, it was found that a particle dispersion liquid without particle agglomerates can be obtained by using a classifying machine as the classifying means 2. Further, it was found that the particle reduction rate was less than 1%, and the charged ratio amount and the assumed composition ratio of the functional coating film were substantially the same. If a classifier is not used as in the comparative example, the particles cannot be efficiently crushed by the crushing means, the dispersion achievement time becomes significantly long, and the particle dispersion liquid is not suitable for production (mass production). I found out.

Although the embodiments and examples of the present invention have been described above, various modifications are possible as long as they do not deviate from the scope of the technical idea of the present invention. In the above embodiments and examples, the case where a high-speed stirrer and a rotor-stator type disperser are used as the crushing means 1 has been described as an example, but a jet mill or a bead mill can be used. However, when a bead mill is used, so-called contamination may occur in which fragments generated by the beads colliding with the particle agglomerates are mixed in the particle dispersion liquid and thus in the functional coating film.

MS ... Dispersion liquid manufacturing equipment, 1 ... High-speed stirrer, Disperser (crushing means), 2 ... Wet classifier (classification means), 3 ... Circulation line, 31 ... Primary line, 32 ... Secondary line.

Claims (2)

In a dispersion liquid manufacturing apparatus for producing a particle dispersion liquid in which particles having a predetermined particle size or less are dispersed in a dispersion medium.
Particle agglomerates in which the particles exceed a predetermined particle size in the dispersion medium are used as particle agglomerates, and a crushing means for crushing the particle agglomerates in the dispersion medium, the particles in the dispersion medium, and the above. A classifying means for classifying the particle agglomerates and a circulation line for circulating a dispersion medium containing at least one of the particles and the particle agglomerates between the crushing means and the classifying means are provided.
The circulation line from the crushing means to the classification means is a primary line, the circulation line from the classification means to the crushing means is a secondary line, and the classification means has two dispersion media containing the particle aggregates. A dispersion liquid manufacturing apparatus characterized in that it is configured to return to the next line. The dispersion liquid manufacturing apparatus according to claim 1, further comprising a bypass line for returning the dispersion medium containing the particles to the primary line from the classification means.

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