JP5488078B2 - Method for producing fine particles using photocuring material - Google Patents

Description

  The present invention relates to an improved method for producing resinous fine particles using an inkjet method.

  Conventionally, many methods for producing resinous fine particles have been proposed. For example, in Japanese Patent No. 3778634 of Patent Document 1, as an improved method of the spray drying process, the raw material is discharged from a piezoelectric element use head portion that discharges a fluid raw material to a tower-like solidified portion, and fine particles However, this technique does not use a photocurable resin, nor does it produce fine particles by discharging droplets into a liquid.

  Japanese Patent Application Laid-Open No. 2006-28432 of Patent Document 2 discloses an aggregate in which a plurality of first fine particles mainly composed of a resin material are ejected from an ejection head, and a second cured photocurability. Although a method for producing resin particles for forming composite particles through a process of melt-bonding with resin particles is disclosed, this is not what is once discharged into a liquid and photocured as in the present invention. Since the powder obtained from the droplets from the nozzle is photocured during transportation, it is insufficiently cured, and the subsequent handling and transportability are inconvenient as a collection of powder fine particles. In this case, since a droplet exists in the liquid and the step of becoming spherical due to the interfacial tension is not taken into account, the shape is likely to be disturbed, and the product is difficult to handle because it is a fine particle powder.

Conventionally, methods for producing fine particles by discharging droplets of raw materials using an ink jet are known, but many are thermosetting materials, and are heated and cured over time.
For example, Japanese Patent Application Laid-Open No. 2004-300366 of Patent Document 3 discloses a method for producing resinous fine particles by discharging a molten material or a liquid material or solution of a resinous material from a liquid jet head into an insoluble medium and solidifying it. Although the specification mentions the possibility of using an ultraviolet curing method in the specification, examples of light-curing curing are not described, and a polyester or epoxy resin containing a hydrocarbon ring has a high glass transition. From the point of view and melt viscosity, it is described that it is preferable, and it is cured by a thermal reaction.

  In Japanese Patent Application Laid-Open No. 61-243803 of Patent Document 4 and Japanese Patent Application Laid-Open No. 61-246202 of Patent Document 5, fine particle monomers are intermittently discharged from a discharge head using a piezoelectric element and then cured or cured. A method for producing fine particles whose content is to be polymerized is disclosed, but thermosetting is used. In the technique described in Japanese Patent Application Laid-Open No. 4-65403 of Patent Document 6, the first liquid containing the addition polymerizable monomer is discharged in the form of droplets from the voltage application nozzle into the second liquid made of water or an aqueous solution. The method relates to a method for producing polymer fine particles including a step, which also uses thermosetting.

It is obvious that the temperature change due to heating has a great influence on the viscosity of the discharge liquid, the dispersion stability of the dispersoid, the solubility in the liquid, etc., when trying to obtain fine particles having a desired particle diameter. .
Further, if the time until the droplets are cured after the droplets are formed is long, the droplets are fused or deformed, and it is difficult to obtain fine particles with good uniformity.

  Furthermore, the technique described in Japanese Patent Application Publication No. 2008-531142 in Patent Document 7 is that the collection base material is solid, and the technique described in Japanese Patent Application Laid-Open No. 2004-91767 in Patent Document 8 is a photocurable resin fine particle. It is a manufacturing method and not a photocuring manufacturing method.

  As a result of intensive studies on a method for producing fine particles by irradiating light after discharging a droplet of the material (B) having an ultraviolet curable material to the receiving liquid (A), the liquid of the material (B) is now Correlation between the physical properties of the droplet and the physical properties of the liquid (A) on the receiving side, changes in physical properties over time, and liquids of different materials (B) when a plurality of types of material (B) droplets are ejected We found some important facts below regarding the behavior between drops.

  A first object of the present invention is to provide a method for producing fine particles having a uniform particle size distribution by an inkjet method, and to produce fine particles effective for producing twin balls having finely colored surfaces. Another object of the present invention is to provide a method for producing colored fine particles such as toner by adding a colorant as a functional material.

As described above, as a result of intensive studies on a method for producing fine particles by irradiating light after discharging a droplet of a material (B) having an ultraviolet curable material into the receiving liquid (A), I found the following facts.
(1) For the production of fine particles, the physical properties of the liquid (A) on the receiving side are very important, and if the static surface tension is 30 mN / m (25 ° C.) or more, the fine particles are hardly generated.
(2) If the light irradiation is not performed promptly after the liquid (A) is discharged, the fine particles are fused or deformed and it is difficult to form uniform fine particles.
(3) A functional material (for example, a colorant) is added to the material (B) to create a plurality of types of liquids (B1, B2,...), Which are discharged to the same location or a nearby location and cured. As a result, the two types of droplets are fused, but one fine particle sphere having different components is formed for each part of the fine particle sphere (for each of the hemispheres in the case of two components) without completely uniformly dissolving.

Thus, the problems of the prior art are suitably solved by the present inventions (1) to ( 9 ) below.
(1) “In a method for producing hardened fine particles using droplets of a raw material (B) containing at least a curable material and having fluidity,
The raw material (B) is used as droplets, and the droplets of the raw material (B) are dissolved or liquids that are not compatible with one phase (A) discharged toward the liquid surface (A) The raw material (B) droplets into the liquid And (A) a fine particle curing step of curing fine particles in the liquid,
The curable material is an actinic ray curable material, and the raw material (B) is composed of a plurality of raw materials (B1, B2,...) Including a functional material. The functional material can be obtained by ejecting droplets of a plurality of raw materials (B1, B2...) Containing the functional material toward the liquid surface (A) and fusing the droplets in the liquid (A). A step of forming combined fine particles, wherein the fine particle curing step irradiates the fused fine particles in the liquid (A) with an actinic ray to cure the formed fine particles. The liquid (A) is mainly composed of water, contains a surfactant, has a static surface tension of 30 mN / m (25 ° C.) or less, and is irradiated with actinic rays for curing. the (B) droplets that performed within 1 hour after being placed in said solution (a) The butterflies, the production method of the fine particles. ";
( 2 ) The above-mentioned (A) The raw material (B) droplet in the liquid has satellite droplets formed at the time of ejection, and microparticles having a small particle diameter are produced using the satellite droplets. The method for producing fine particles according to item (1) . ”;
( 3 ) The item (1) or (2), wherein the droplet is deformed by creating a flow in the liquid (A) before light irradiation, and deformed fine particles are produced by light irradiation as it is. The method for producing fine particles according to the above. ";
( 4 ) "Items (1) to (3) above, wherein the discharge of the raw material (B) droplets toward the liquid surface (A) uses a piezo-type inkjet head. Or a method for producing the fine particles according to any one of the above.
( 5 ) "Items (1) to (3), wherein the discharge of the raw material (B) droplets toward the liquid surface (A) uses a thermal inkjet head" Or a method for producing the fine particles according to any one of the above.
( 6 ) "The method for producing fine particles as described in (1) above, wherein the surfactant is a fluorine-based or silicon-based surfactant";
( 7 ) "The method for producing fine particles according to item (1), wherein the functional material is a colorant";
( 8 ) “The method for producing fine particles according to any one of items (1) to (7), wherein fine particles having a small particle diameter are produced by an electrospray deposition method”;
( 9 ) “ A layer of the liquid (A) is provided on the actinic ray curable liquid (C), and the raw material (B) droplets are ejected toward the surface of the layer to irradiate the light. The method for producing fine particles according to (1) above, wherein a film in which the fine particles obtained by curing the raw material (B) are adhered on the cured film of the actinic ray curable liquid (C) is prepared by evaporation .

As will be understood from the following description, as advantages of producing fine particle spheres by ink jetting by the method of the present invention, (1) fine particles having a very uniform particle size can be produced, and (2) the particle size is an ejection droplet of an ink jet. It can be arbitrarily adjusted by applying a technique for adjusting the size of the particle, and (3) it is possible to suppress disturbance of the particle diameter due to the fusion of the droplets by rapid photocuring.
According to the present invention, in addition to that, a plurality of types of droplets (B1, B2,. Thus, it is possible to produce fine particles having different components (in the case of two components, the components of the hemisphere and the hemisphere are approximately different).

Such fine particles can be applied in various fields. For example, if a negatively chargeable material and a positively chargeable material are combined, fine particles having portions with different charge polarities in one particle can be formed.
If a colorant is added to one side, the direction is changed by the electric field, and the display function can be expressed by the colorant.
In addition, it is possible to impart photochargeability of particles by fine particles in which a charge generating agent and a charge transporting agent are combined.
Furthermore, fine particles that can be used as spacers for liquid crystal displays, backlight light diffusing agents, twin balls for paper displays, matting agents, lubrication improvers, colored fillers, resin stress relaxation agents, and the like can be produced.
The “functional material” in the present specification is discharged together with the actinic ray curable material, and simultaneously fixed by the curing of the actinic ray curable material, so as to be optical, electrical, magnetic, biological, mechanical It means a material having a function that has a useful or chemically useful function as an attribute.

In addition, as a manufacturing method of a twist ball (two-color ball) used for an electric paper display, there is a spin disk method described in US Pat. No. 5,262,098 of Patent Document 9, but the particle diameters are uniformed. Have difficulty.
The present invention can be applied to the production of twist balls having a uniform particle diameter.

  In addition, after producing fine particles by the method of this patent, fine particles obtained by filtering and separating water can be used as spacers such as liquid crystals by spraying or other methods, but the liquid (A) is directly applied to the substrate, (B) After the liquid is imprinted and photocured, the liquid (A) can be evaporated to form a spacer portion for liquid crystal production.

Further, it can be used as fine particles for a light diffusion sheet as described in Japanese Patent No. 4306318 of Patent Document 10. In order to fix the position of the fine particles, a layer that adheres to the fine particles may be provided in advance in the lower layer of the liquid (A).
It can also be used for the production of an antiglare film as described in JP 2004-151642 A.

  Furthermore, after the (B) droplets are discharged into the liquid (A) and before light irradiation, a flow is formed in the entire liquid, the particles are deformed, and if the light is irradiated, deformed particles can be produced.

It is an optical microscope photograph of the hardening fine particle by Example 1 of this invention. It is an optical microscope photograph of the hardening magenta coloring fine particle by Example 2 of this invention. 4 is an optical micrograph of cured cyan-magenta colored fine particles according to Example 3 of the present invention. 4 is a partially enlarged photograph of an optical micrograph of cured cyan-magenta colored fine particles according to Example 3. FIG. It is the figure and model figure by which the functional material fuse | melted and the functional fine particle from which a component differs for every hemisphere was formed. 2 is an optical micrograph according to Comparative Example 1. The dynamic surface tension value and the static surface tension of each receiving liquid are plotted. The horizontal axis indicates the time until measurement. 6 is an optical micrograph according to Comparative Example 2. It is a model figure of manufacture of the microparticles | fine-particles as an example of this invention, and its utilization method.

<Viscosity>
The viscosity here is measured at 25 ° C. using a rotational viscometer (manufactured by Toki Sangyo Co., Ltd., Viscoat TV22).
<Static surface tension>
The static surface tension was measured at 25 ° C. using a static surface tension meter (manufactured by Kyowa Interface Science Co., Ltd., CBVP-Z type). Follow Wilhelmi's law. A stable value was recorded 1 to 2 minutes after the start of measurement. In addition, although a value fluctuates somewhat with elapsed time, if it is 30 mN / m (25 ° C.) or less, fine particles are reliably formed. If it is 35 mN / m or more, the formation of fine particles becomes difficult.
<Dynamic surface tension>
The dynamic surface tension was measured at 25 ° C. using a dynamic surface tension meter (SITA Messtechnik GmbH, SITA DynaTester). It is a bubble pressure system. After surface formation, the relationship between elapsed time and surface tension was measured.

[Curable material]
Hereinafter, the present invention will be described in detail and specifically with reference to the drawings.
As a curable material used for the discharge liquid (B), at least a material having photocurability may be used.
For that purpose, radical polymerization, cationic polymerization, or anionic polymerization of various photocurable monomers, oligomers, polyfunctional monomers, and polyfunctional oligomers are preferably used as the main material.
Moreover, the photocuring initiator corresponding to each is used preferably.
In addition, a surfactant for adjusting physical properties is also necessary in some cases.
Any of those used as so-called inkjet UV inks can be used.
In the present specification, the raw material (B) “has fluidity” means that the raw material (B) has fluidity to such an extent that it can be discharged from, for example, the heads of various printers. However, the head may be heated for ejection. That is, it may be a normal temperature solid phase change type ultraviolet curing agent. What is necessary is just a solution at the time of a heating. In the case of electrospray deposition, a considerably high viscosity material can be discharged.
Regarding the (B) liquid, its physical properties are not as important as the (A) liquid, and any ordinary inkjet ultraviolet curable ink can be used.
The physical properties of normal ultraviolet curable ink are 20 mPas or less, generally 3 to 15 mPas at the temperature at the time of ejection, and 5 to 100 mPas (25 ° C.), preferably 5 to 50 mPas (25 ° C.) at room temperature. When the viscosity is high at room temperature, the head is heated and discharged. Usually, it is often heated at 40 to 60 ° C.
Further, the surface tension is usually 20 to 35 mN / m (25 ° C.) in many cases.
The density is often 1.05 to 1.15 (25 ° C.).
As usual components, UV curable resin is about 75 to 90% by weight, initiator is 3 to 10% by weight, colorant is 3 to 10% by weight, and colorant dispersant is 1 to 5% by weight. It is. In some cases, a surfactant is added in an amount of about 0.01 to 0.05% by weight, and a sensitizer is added in an amount of 1 to 5% by weight. The pigment may be an elementary pigment or may be processed by a method as described in JP-A-2004-18656.
Various functional fine particles can be produced from ink containing a functional material characterized by electrical characteristics, magnetic characteristics, and biological characteristics instead of these colorants.

[Functional materials]
A representative functional material added to these is a colorant, which may be a pigment or a dye.
As described above, the “functional material” in the present specification is discharged together with an actinic ray curable material, and simultaneously fixed by the curing of the actinic ray curable material, and is optically, electrically, and magnetically , Means a material having a function of biologically, mechanically or chemically useful as an attribute, but as a material, in addition to a colorant, a function characterized by electrical characteristics, optical characteristics, biological characteristics, etc. The photocurable material molecule itself may have such a function.

[Receiving liquid (A)]
What is important is that the discharge liquid (B) is not instantaneously compatible with the receiving liquid (A).
It must not be dissolved by at least light irradiation.
However, if it can be cured even if it is compatible to some extent, there is a possibility that a characteristic material can be obtained.
In general, when a water-insoluble photocurable liquid is ejected, the receiving liquid (A) is preferably a water-soluble liquid so as not to dissolve the ejected liquid (B).
As for the receiving liquid (A), any amount may be used as long as it is satisfied that the light for curing is transmitted and that the ejected droplet is spherical. The thickness is 1 to 10000 times, preferably several times to 1000 times the diameter.
However, in the case of producing a large amount of fine particles, the number of nozzles may be increased, and a large amount of (A) liquid may be continuously discharged and photocured.
(B) Regarding the liquid discharge amount, if it is not desired to fuse the droplets, the interval between the droplets should be as wide as possible. In the case of the present invention, particles having a uniform diameter were obtained with 7 pl droplets (diameter: about 23 μm) and 150 dpi × 150 dpi (interval 169 μm). If this becomes a resolution of 1200 dpi 1200 dpi (space 21 μm), fusion may occur. It is preferable not to print at a resolution that is denser than the diameter of the drop.
On the other hand, if you want to fusing different types of drops intentionally, for example, if you want to fuse cyan and magenta drops, and if you want to create fine particles of cyan for the hemisphere and magenta for the hemisphere, make the cyan and magenta drops land nearby. There is a need. Also in this case, there is a limit to the discharge resolution as described above in order to avoid the fusion of further drops.
(B) Regarding the discharge amount of one drop of liquid, the discharge amount of one drop determines the diameter of the fine particles to be formed, but this differs depending on the purpose. At present, in the case of the piezo method, 2 pl to 40 pl is possible in consideration of the particle formation stability.
However, finer particles having a smaller diameter can be obtained by using satellites generated during ejection as in the present invention or by using mist formation as in electrospray deposition.

[Surfactant]
As a result of the study in the present invention, it was very preferable to add a surfactant for the production of fine particles. By adding the surfactant, the surface tension of the liquid (A) decreases, and the liquid (B) easily enters the liquid (A) and becomes fine particles. (Strictly speaking, whether or not it is completely inside the liquid (A) depends on the density difference, but at least tends to be spherical due to a decrease in surface tension.)
(A) The liquid must have a transparent wavelength portion at least at the wavelength of the irradiation light so that light can reach the (B) droplet.

As the surfactant to be added to the receiving liquid, nonionic, anionic and materials can be used. In order to lower the surface tension, fluorine and silicon surfactants are particularly effective.
For example, surfactants such as those described in JP-A-2009-62519, Japanese Patent No. 3993022, Japanese Patent No. 4268368, Japanese Patent No. 3952794 are effective.
A preferable addition amount will be described in detail later, including its analysis.

[Alternate process]
The above is a case where an oily photocurable liquid is ejected onto an aqueous liquid and irradiated with light. Conversely, an aqueous photocurable liquid is ejected onto an oily liquid and irradiated with light. There is also a possibility.

[Manufacture of fine particles]
In addition, after creation of cured fine particles, only the fine particles can be easily separated by filtration using an aqueous liquid filter.
Further, it may be used by applying it while the fine particles are present in water and drying the water.
It is useful as a light diffusing agent for liquid crystal display spacers and backlights.
If it is desired to make the particle diameters uniform, it may be discharged so that no satellite is present.
Normal ink jet technology can be used.

[Discharge means]
As the ink jet head, the piezo method is preferable to the thermal method.
The reason is that it is easy to discharge high-viscosity ink and it is easy to change the size of the droplets.
Since the photocurable ink generally has a high viscosity, it is necessary to heat the head so that the viscosity is 10 mPas or less. However, heating is not necessary if the head is capable of discharging a high viscosity liquid.

[satellite]
In order to produce ultrafine particles using satellites, filtration with a filter capable of separating satellites and main droplets is possible, but since the particle sizes are simple, centrifugation and sedimentation separation are also possible. is there.

  In addition, if a plasticizer is added to the photocurable liquid or a material is selected so as to lower the softening temperature after curing, it can be used as a colorant particle, a toner, or a colored particle for inkjet.

  Hereinafter, the present invention will be described in more detail and specifically by way of examples. However, these examples are not intended to limit the present invention, but to facilitate understanding of the present invention. Unless otherwise indicated, “part” in each example represents “part by mass”.

[Preparation of droplet (B)]
The following composition was used after being dispersed by a sand mill and filtered.
[Injection liquid (B) -1; black ink]
A liquid for drops (B) having the following composition was prepared.
Liquid formulation UV monomer (radical) (2-phenoxyethyl acrylate, etc.) 85 parts Initiator (radical generator: Irgacure 907 manufactured by Ciba Specialty Chemicals) 7.5 parts Colorant (carbon black) 2.5 parts Ester solvent 2.5 parts Other small amount of additives (pigment dispersant) The physical properties were adjusted as follows by adding several parts by weight.
Static surface tension: 23 mN / m

[Injection liquid (B) -2; Magenta ink]
A liquid for drops (B) having the following composition was prepared.
Liquid formulation UV monomer (radical) (2-phenoxyethyl acrylate, etc.) 75 parts Initiator (radical generator) 7.5 parts Magenta pigment (quinacdrine pigment) as a colorant 7.5 parts Ester solvent 2.5 parts Other small amount of additives (pigment dispersant) The physical properties were adjusted as follows with the addition of several parts by weight.
Static surface tension: 23 mN / m
(This is, of course, merely an example. For the preparation of the liquid for black droplets, for example, 80 to 90 parts of the UV monomer, 5 to 10 parts of an initiator (radical generator), and a colorant are used. (Carbon black) can be used very suitably in the range of 1 to 5. The same applies to the liquid for magenta drops and the liquid for cyan drops. Can be similarly produced.

[Injection liquid (B) -3; cyan ink]
A liquid for drops (B) having the following composition was prepared.
UV monomer (radical) (2-phenoxyethyl acrylate, etc.) 85 parts Initiator (radical generator) 7.5 parts Cyan pigment (phthalocyanine pigment) as colorant 2.5 parts Ester solvent 2.5 parts Other small amount Additives (pigment dispersants, etc.) Added with several parts by weight, the physical properties were adjusted as follows.
Static surface tension: 21 mN / m

[Preparation of receiving liquid (A)]
[Receiving liquid (A) -1]
A receiving liquid (A) having the following composition was prepared.
Ion exchange water: 1 part Fluorosurfactant MegaFac F410 (manufactured by DIC Corporation): 1%
Dynamic surface tension (mN / m) (25 ° C)
; 34.3 (15 msec)
19.2 (150 msec)
16.8 (1500 msec)
Static surface tension (25 ° C.); 16.0 mN / m

[Receiving liquid (A) -2]
A receiving liquid (A) having the following composition was prepared.
The amount of the surfactant (A) -1 is 0.1%
Dynamic surface tension (mN / m) (25 ° C)
; 67.5 (15 msec)
56.4 (150 msec)
44.7 (1500msec)
Static surface tension (25 ° C.); 16.7 mN / m

[Receiving liquid (A) -3]
A receiving liquid (A) having the following composition was prepared.
The amount of the surfactant (A) -1 is 0.035%.
Dynamic surface tension (25 ℃)
; 68.1 (15 msec)
66.3 (150 msec)
62.7 (1500 msec)
Static surface tension (25 ° C.); 21.0 mN / m

[Receiving liquid (A) -4]
A receiving liquid (A) having the following composition was prepared.
0.01% of the amount of the surfactant (A) -1
Dynamic surface tension (mN / m) (25 ° C)
71.4 (15 msec)
70.0 (150msec)
68.9 (1500 msec)
Static surface tension (25 ° C.); 30.4 mN / m

The receiving liquid (A) -1 was formed into an aqueous liquid film with a thickness of about 1 mm on a slide glass.
The printing liquid (B) -1 was printed on the liquid surface (resolution: 150 dpi in the X direction, 150 dpi in the Y direction).
Line-type 1-pass printing with one row of nozzles.
A piezo inkjet printing apparatus was used.
The discharge was performed by heating the UV curable liquid (B) to 40 ° C. The size of one drop is about 7 pl. Drop ejection speed is about 7m / sec.
Thereafter, light irradiation curing was performed. Light irradiation curing (metal halide lamp: INTEGRATION TECHNOLOGY, SubZero 085S) was performed 19 msec after discharging with the apparatus provided at the rear in one axis direction after printing of the liquid (B).
Therefore, in this case, the head feed speed is 1800 mm / sec and the ejection frequency is 10.63 kHz.
The amount of light irradiation was such that at least the vicinity of the surface was sufficiently cured (light intensity was 638 mW / cm ² , integrated light amount 11 mJ / cm ² ).
As a result, cured fine particles were produced as shown in FIG. The fine particles gradually move in the liquid and gather, but the fine particles do not fuse because they are already cured.
In this figure, small droplets are due to satellites, and large droplets are fine particles made from main droplets.
Due to the difference in moving speed, they can be assembled separately and separated from each other. When satellites are used in this way, fine particles having a small particle diameter can be produced.
In addition, since the diameter of each particle is constant using an inkjet, there is very little variation in particle diameter.

Fine particles were produced in the same manner as in Example 1 except that the printing liquid was changed to (B) -2.
However, light irradiation curing (metal is a ride lamp) was performed 350 msec after discharge by the apparatus provided in the rear part in the uniaxial direction after the printing of the liquid (B).
Therefore, in this case, the head feed speed is 100 mm / sec and the ejection frequency is 0.59 kHz.
As in the case described above, the amount of light irradiation was such that at least the vicinity of the surface was sufficiently cured (light intensity was 638 mW / cm ² , integrated light amount 189 mJ / cm ² ).
As a result, similarly magenta-colored cured fine particles were produced. FIG. 2 shows the photographed result. Most of them are two kinds of fine particles of the size of satellite and main drop, and both can be easily separated by filtration.

In the same manner as in Example 2, after curing the cyan and magenta UV curable inks of the printing liquids (B) -2 and (B) -3 onto the receiving liquid (A) -1, the cured fine particles were irradiated with light. Was made.
Cyan cured particles and magenta cured particles were produced. FIG. 3 shows the photographed result.
Among them, cured fine particles in which cyan and magenta were partially fused were produced. FIG. 4 which is a partially enlarged view of FIG. 3 shows the photographed result.
It seems that what happened to have the same discharge position was fused before curing.
Since the time until light irradiation after ejection is short, it can be seen that the colorants of the fine particles are separated into hemispherical parts without mixing colors.
This means that fine particles having different components for each hemisphere can be produced if the discharge positions are the same.
When the cyan and magenta ejection positions were printed at substantially the same position, more composite fine particles were formed.

In the same manner as in Example 3, the UV curable ink (B) -2 or (B) -3 was applied to the receiving liquid (A) -2 or (A) -3, and then irradiated with light.
As a result, cured fine particles similar to those in Example 3 were produced.

[Comparative Example 1]
In the same manner as in Example 4, the receiving liquid was changed to (A) -4.
As a result, the water surface of (A) -4 was repelled and separated. In addition, although there were droplets ejected into water, fine particles were not prepared at all, and a surface such as a cured film of oil liquid was formed on the surface.
FIG. 5 shows the photographed result.
Thus, when the addition amount of the surfactant is small (that is, the surface tension of the liquid (A) is large), the fine particles cannot be produced. For the production of fine particles, 35 mN / m or less, preferably 30 mN / m or less (25 ° C.) is preferable.
(A) Even if pure water is used as the liquid, fine particles cannot be produced.
Thus, the physical properties of the receiving liquid are important for the production of fine particles, and the mechanism is currently unknown. However, if the surface tension is not low to some extent, it is considered that the ejected droplet does not enter the inside.

[Dependence of dynamic surface tension of receiving liquid (A) over time]
FIG. 6 is a plot of the surface tension of each receiving liquid with time to measurement.
Here, the static surface tension is plotted as a value after 60 seconds, but is a stable region that does not change so much even from 10 seconds to several tens of minutes.

[Comparative Example 2]
FIG. 7 shows a photograph in Example 3 when one hour or more has passed without light irradiation.
It can be seen that the droplets are partly fused to a large particle size.
This is not unusable, but it is understood that it is preferable to cure by light irradiation at least within 1 hour after injection for the production of fine particles having a uniform particle diameter.

  (B) The following liquid was used.

物性を以下に示す。

The physical properties are shown below.

This was conducted in the same manner as in Example 2.
In this case as well, fine particles were formed when the static surface tension of the liquid (A) was 30 mN / m or less, as in the previous example.
In addition, fine particles having different components for each hemisphere were formed by fusing different types of droplets.
Further, fine particles having a small particle diameter were formed by the satellite.

物性を以下に示す。

The physical properties are shown below.

This was conducted in the same manner as in Example 1.
In this case as well, fine particles were formed when the static surface tension of the liquid (A) was 30 mN / m or less, as in the previous example.
In addition, fine particles having different components for each hemisphere were formed by fusing different types of droplets.
Further, fine particles having a small particle diameter were formed by the satellite.

Applying a voltage of 5000 V or more between the injection nozzle and the substrate, the charged droplets are ejected, and the droplets are separated into mists by the charged electric charge, so-called electrospray deposition method. This is an example showing that a mist-like droplet having an extremely small particle diameter can be ejected onto a liquid, and light-irradiated to produce cured fine particles having an extremely small particle diameter.
The power supply and system were discharged from (B) -1 to (B) -9 into (A) -1 solution at an applied voltage of 10000 V using an electrospray deposition system Espray 2000 from Fuens Co., Ltd. It can be cured to form very fine colored particles.

As an example of application of the fine particle forming apparatus system of the present invention, as shown in FIG. 8, the liquid (A) is applied onto a substrate by a coating device for receiving layer liquid (liquid A) and photocured by an ink jet coating apparatus. The liquid containing the material (liquid B) was discharged to form spherical particles in the liquid (A), and only the fine particles were collected by filtration separation.
It is also possible to evaporate the liquid (A) and use it as it is after it is irradiated with light to form cured fine particles.

[Use of electrospray deposition method]
A so-called electrospray deposition method is known in which droplets are discharged while applying a high electric field and separated into minute mists by charging the droplets. Then, nano-level cured fine particles can be formed.
Nano-level colored fine particles can be used as an inkjet colorant.

Japanese Patent No. 3786034 JP 2006-28432 A JP 2004-300136 A JP-A-61-243803 JP-A-61-246202 JP-A-4-65403 JP-T 2008-5312142 JP 2004-91767 A US Pat. No. 5,262,098 Japanese Patent No. 4306318 JP 2004-151642 A

Claims (9)

In a method for producing hardened fine particles using droplets of a raw material (B) containing at least a curable material and having fluidity,
The raw material (B) is used as droplets, and the droplets of the raw material (B) are dissolved or liquids that are not compatible with one phase (A) discharged toward the liquid surface (A) The raw material (B) droplets into the liquid And (A) a fine particle curing step of curing fine particles in the liquid,
The curable material is an actinic ray curable material, and the raw material (B) is composed of a plurality of raw materials (B1, B2,...) Including a functional material. The functional material can be obtained by ejecting droplets of a plurality of raw materials (B1, B2...) Containing the functional material toward the liquid surface (A) and fusing the droplets in the liquid (A). A step of forming combined fine particles, wherein the fine particle curing step irradiates the fused fine particles in the liquid (A) with an actinic ray to cure the formed fine particles. The liquid (A) is mainly composed of water, contains a surfactant, has a static surface tension of 30 mN / m (25 ° C.) or less, and is irradiated with actinic rays for curing. the (B) droplets that performed within 1 hour after being placed in said solution (a) The butterflies, the production method of the fine particles. Wherein the material (B) droplets in the solution (A) has a satellite droplet formed during the discharge, according to claim 1, characterized in that to produce the fine particles of the small particle size by using a satellite droplet Method for producing fine particles. The method for producing fine particles according to claim 1 or 2 , wherein the droplets are deformed by creating a flow in the liquid (A) before light irradiation, and deformed fine particles are produced by light irradiation as it is. The fine particle production according to any one of claims 1 to 3 , wherein ejection of the raw material (B) droplets toward the liquid surface (A) uses a piezo-type ink jet head. Method. The fine particle production according to any one of claims 1 to 3 , wherein ejection of the raw material (B) droplets toward the liquid surface (A) uses a thermal ink jet head. Method. The method for producing fine particles according to claim 1 , wherein the surfactant is a fluorine-based or silicon-based surfactant. The method for producing fine particles according to claim 1 , wherein the functional material is a colorant. The method for producing fine particles according to any one of claims 1 to 7 , wherein fine particles having a small particle diameter are produced by an electrospray deposition method. By providing a layer of the liquid (A) on the actinic ray curable liquid (C), discharging the raw material (B) droplets toward the layer surface, irradiating with light, and then evaporating the water in the liquid (A) The method for producing fine particles according to claim 1 , wherein a film in which the fine particles obtained by curing the raw material (B) are adhered on the cured film of the actinic ray curable liquid (C) is produced.

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