JP2008183554A - Method for producing dispersion liquid of organic fine particle, and organic fine particle obtained thereby - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a dispersion liquid excellent in dispersion stability and preservation stability of organic fine particles having small size and a sharp peak in a particle size distribution thereof, by which the excellent dispersion liquid of organic fine particles can be obtained efficiently with high purity and which is suitable for mass production (scale-up). <P>SOLUTION: The method for producing the dispersion liquid of organic fine particles comprises the steps of: circulating a solution which is obtained by dissolving an organic compound in a solvent, and a precipitating solvent at least a part of which can be dispersed in the solvent, through a flow passage having ≤1 mm equivalent diameter to bring the solution into contact with the precipitating solvent; precipitating the organic compound as fine particles in the presence of a polymerizing compound at the step of circulating the solution and the precipitating solvent; polymerizing the polymerizable compound; and fixing the polymer of the polymerizable compound onto each of the precipitated fine particles. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing an organic fine particle dispersion and the organic fine particles obtained thereby, and more specifically, a method for producing an organic fine particle dispersion in which a coexisting polymerizable compound is polymerized to stabilize the dispersion and the organic fine particles obtained thereby About.

  Research on inorganic / semiconductor nanoparticles began in the 1980s, and research on gold / silver nanoparticles, which are expected to produce an electric field effect due to fluorescent semiconductor nanoparticles for biolabeling and phase surface plasmons, has been extensively conducted. However, research on clear nano-sized particles has been delayed in the field of organic and polymer materials. The main reason for this is that high-temperature heating operations (vacuum deposition, melt deposition, etc.) used in the production of inorganic / semiconductor nanoparticles are generally not applicable to thermally unstable organic compounds. This is because it was difficult to synthesize nanometer-sized organic fine particles.

On the other hand, regarding the ultrafine particle material of nanometer size constituting the intermediate region between the bulk and the molecular size, the expectation as an electronic material is higher than before. The reason is that these materials exhibit very interesting properties in terms of optical properties and nonlinear optical characteristics due to the size effect.
Thus, research on organic fine particle materials that have been delayed is expected to be promoted.

  In the field of medicine, it is important to prepare drugs as appropriate capsules in the diagnosis and treatment of lesions such as cancer using a drug delivery system. For example, cancer cells have nanometer-sized voids between the cells, and a delivery system based on a passive method in which drugs are accumulated and taken up has been proposed. Thus, development of a method for synthesizing organic fine particles with a controlled size is also required in the pharmaceutical field.

  In other fields, dyes have been used as coloring materials for inkjet inks. However, there are problems in terms of water resistance and light resistance, and pigments have been used to improve the problem. The image obtained with the pigment ink has a remarkable advantage in that it is excellent in light resistance and water resistance as compared with the image obtained by the dye-based ink. However, it is difficult to uniformly reduce the size to a nanometer size that can penetrate into the voids on the paper surface, and there is a problem of poor adhesion to paper.

Further, regarding the increase in the number of pixels of a digital camera, it is desired to reduce the thickness of a color filter used in a CCD sensor. An organic pigment is used for this color filter. However, since the thickness of the filter greatly depends on the particle diameter of the organic pigment, it is desired to produce stable fine particles at a nanometer size level.
As described above, there is an increasing expectation for an effective production method that enables research and practical application of organic fine particles in various fields.

As a method for producing organic fine particles developed to meet such expectations, there is a method called “reprecipitation method” (see Patent Documents 1 and 2 and Non-Patent Document 1). This method is useful for nano-crystallization of π-conjugated organic / polymeric substances (eg, low molecular weight aromatic compounds such as polydiacetylene, perylene, fullerene, organic sulfur dyes) and organic pigments that are interested in electronic and optical properties. It is a versatile and excellent method in terms of applicability. There are several methods for reprecipitation, in which the organic compound is dissolved in a solvent (good solvent) that well dissolves the organic compound to be microparticulated, and the solution is dissolved in a solvent (poor solvent) that hardly dissolves the organic compound. Injecting with vigorous stirring to reprecipitate and precipitate, dissolving the organic compound in a solvent that is difficult to dissolve under normal conditions in a supercritical state, and then nanocrystallizing it by mixing with a cooling solvent (supercritical Reprecipitation method).
However, both methods require stirring of the solution if efficient fine particles are to be obtained. For this reason, the stirring effect becomes non-uniform at the time of scale-up, and it is extremely difficult to scale up and reproduce the result obtained at the time of small scale, for example, in the particle size distribution. Furthermore, there is a problem that thickening is difficult, and an improvement has been desired.

  Many so-called microencapsulation methods for encapsulating fine particles are also known. Microcapsule production methods include physical methods, mechanical methods, chemical methods, and physicochemical methods. Physical or mechanical methods require special equipment, lack the denseness and strength of the membrane wall, are fragile and the core material is likely to leak over time. The chemical method and the physicochemical method can be produced by controlling the fact that no special equipment is required and the microcapsule particle size is as small as 1 μm or less to as large as several mm.

  Here, as a chemical method, an interfacial polymerization method in which a monomer is polymerized at the interface between the oily core material and the aqueous phase to form a membrane wall, and a membrane wall is formed by polymerizing only in one of the oily core material or the aqueous phase in- There is a situ polymerization method.

  For the interfacial polymerization method, for example, an emulsifying dispersant is used, and the oily core substance is first emulsified and dispersed in the aqueous phase. As the curing agent for forming the film wall, a highly reactive compound such as isocyanate, acid chloride, or epoxy compound is used. Therefore, the microcapsule film is tough, but it is difficult to control the polymerization reaction.

  On the other hand, in the in-situ polymerization method, for example, a water-soluble anionic polymer electrolyte is used as an emulsifying dispersant, and an amino resin such as a melamine resin is used as a curing agent for forming a membrane wall. It has the advantages of being inexpensive, requiring no special catalyst for the polymerization reaction, and easily producing microcapsules in a short time. However, in this method, the emulsified dispersion of the oily core substance, the denseness of the membrane wall, etc. are worse than the other methods, and it is necessary to devise.

  As a physicochemical method, there is a method in which a polymerization reaction is performed by adsorbing a polymerizable compound to a core substance by physical adsorption or deposition by a difference in hydrophilicity / hydrophobicity of the compound or pH control. However, it is essentially difficult to control and adsorb an appropriate amount or type of polymerizable compound on the particle surface. Therefore, it must be said that it is difficult to control the desired size by the subsequent polymerization reaction.

  In recent years, a technique for performing a chemical reaction using a reaction channel having a minute channel cross-sectional area, so-called “microchemical process technology”, has attracted attention (Non-Patent Document 2). “Micro chemical process technology” is a material production / chemical analysis technology that uses chemical / physical phenomena expressed in a micro flow channel of several μm to several hundred μm wide created on a solid substrate by micro processing technology. is there.

  In micro space, the Reynolds number is small, so it is dominated by laminar flow, and mixing is performed by molecular diffusion through the interface. In the micro space, the specific surface area of the interface is large, and the movement distance of the molecule is small, so that the mixing is performed instantaneously by molecular diffusion through the interface. Therefore, precise high-speed mixing is possible as compared with turbulent mixing using a stirrer on a normal macro scale. Moreover, since the reaction is generally carried out in a flow, the flow rate can also be precisely controlled, and therefore the reaction time can be precisely controlled. Furthermore, since heat transfer is easy, precise temperature control is possible.

  As a technique for forming fine particles in a micro space, there is a technique for preparing organic pigment fine particles in a flow path, and organic pigment fine particles having a uniform particle diameter can be obtained quickly under mild conditions. There is no specific description of dispersion stability (Patent Documents 3 and 4). Moreover, although the microdevice which has several subchannels is disclosed (patent document 5), there is no description about preparation of organic pigment microparticles using this.

  By the way, the technique which synthesize | combines a water-insoluble coloring material particle | grain in a flask irrespective of a micro process, and superposes | polymerizes a polymerizable compound at this time is disclosed (refer patent document 6). Thereby, it is said that a dispersion liquid with fine colorant particles and high transparency is obtained, but it is desired to further improve the thermal stability of the dispersion liquid. In addition, a method for synthesizing, precipitating or crystallizing a color material in the presence of a block copolymer without using a polymerizable compound in the synthesis of a color material by a microchemical process is disclosed (Patent Literature). 7). In the manufacturing method described in Patent Document 7, depending on the use of the color material substance dispersion, it is said that each block of the coexisting block copolymer can have a desired function. It is desired to secure the solubility when dissolving the block copolymer and to more reliably prevent the blockage of the flow path.

JP-A-6-79168 JP 2004-91560 A NANOSCIENCE AND TECHNOLOGY, “Single Organic Nanoparticles”, Chap. 2, 14, 29, Spring-Verlag, Berlin (2003). W. Ehrfeld, V.M. Hessel, H.C. Loewe, “Microreactors”, 1 Ed. (2000), WILEY-VCH. JP 2005-307154 A JP 2006-263538 A JP 2005-288254 A JP 2004-43776 A JP 2006-104448 A

  An object of the present invention is to provide a method for producing an organic fine particle dispersion having a small size, a sharp particle size distribution peak, and excellent dispersion stability and storage stability. Another object of the present invention is to provide a method for producing an organic fine particle dispersion which can obtain the above excellent fine particle dispersion efficiently and with high purity and is suitable for mass production (scale-up).

The above object of the present invention has been achieved by the following means.
(1) A solution in which an organic compound is dissolved in a solvent and a precipitation solvent that is different from the solvent and that can diffuse at least partially in the solvent are circulated through a channel having an equivalent diameter of 1 mm or less. The organic compound was precipitated as fine particles in the presence of the polymerizable compound in the distribution process, and then the polymerizable compound was polymerized, and the polymer of the polymerizable compound was immobilized on the fine particles. A method for producing an organic fine particle dispersion.
(2) The method for producing an organic fine particle dispersion according to (1), wherein a polymerizable compound is contained in at least one of the organic compound solution and the precipitation solvent.
(3) A solution obtained by dissolving an organic compound in a solvent and a deposition solvent different from the solvent and capable of diffusing at least partly in the solvent are circulated as a laminar flow in the flow path to bring them into contact with each other. In the distribution process, the organic compound is precipitated as fine particles in the presence of the polymerizable compound, and then the polymerizable compound is polymerized, and the polymer of the polymerizable compound is fixed to the fine particles. A method for producing an organic fine particle dispersion.
(4) The method for producing an organic fine particle dispersion according to (3), wherein a polymerizable compound is contained in at least one of the organic compound solution and the precipitation solvent.
(5) The method for producing an organic fine particle dispersion according to any one of (1) to (4), wherein the precipitation solvent is a poor solvent for the organic compound.
(6) The method for producing an organic fine particle dispersion according to any one of (1) to (5), wherein the flow contact in the flow path is performed in a micro reaction field.
(7) The method for producing an organic fine particle dispersion according to (6), wherein the flow contact in the flow path is performed by a microreactor.
(8) When mixing the liquid flow of the solution in which the organic compound is dissolved in the solvent and the liquid flow of the precipitation solvent, at least one liquid flow is divided into a plurality of divided liquid flows, The central axis of at least one divided liquid flow of the plurality of divided liquid flows and the central axis of the other liquid flow are merged so as to intersect at one point in the merge region, and mixed. The method for producing an organic fine particle dispersion according to any one of (1) to (7).
(9) The organic fine particles according to (8), wherein the plurality of divided liquid flows circulate in a flow path extending radially from the central confluence region toward the central confluence region and are mixed and mixed. Manufacturing method.
(10) The method for producing an organic fine particle dispersion according to any one of (1) to (9), wherein the polymerizable compound is a polymerizable surfactant.
(11) The production of the organic fine particle dispersion according to any one of (1) to (10), wherein at least one dispersant is contained in at least one of the organic compound solution and the precipitation solvent. Method.
(12) The method for producing an organic fine particle dispersion as described in (11), wherein at least one of the dispersants is a polymer dispersant.
(13) The method for producing an organic fine particle dispersion according to (12), wherein at least one of the polymer dispersants is a block copolymer compound.
(14) The method for producing an organic fine particle dispersion according to (13), wherein the block copolymer compound is an amphiphilic polymer.
(15) At least one of the organic compound solution and the precipitation solvent contains at least one monomer that is copolymerized with the polymerizable compound, (1) to (14), A method for producing an organic fine particle dispersion.
(16) The method for producing an organic fine particle dispersion according to any one of (1) to (15), wherein a solution obtained by dissolving the organic compound in a solvent contains a polymerization initiator.
(17) The method for producing an organic fine particle dispersion according to (16), wherein the polymerization initiator is a polymer azo polymerization initiator.
(18) Organic fine particles produced by the method according to any one of (1) to (17).
(19) The organic fine particles according to (18), wherein the mode diameter is 1 μm or less.

According to the production method of the present invention, an organic fine particle dispersion liquid that can obtain organic fine particles having a small size and a sharp particle size distribution peak, and having excellent organic fine particles in dispersion stability and storage stability. As a result, an excellent effect can be obtained.
Further, according to the production method of the present invention, the production from organic fine particles to dispersion stabilization can be carried out continuously, and there is no need for extra steps such as separation of organic fine particles and switching of processes, and the purity is improved efficiently. Good and stable organic fine particles can be obtained, and further, even when mass-produced (scaled up), an organic fine particle dispersion can be obtained without deteriorating the above-mentioned good characteristics.

  In the method for producing an organic fine particle dispersion of the present invention, a solution in which an organic compound is dissolved (hereinafter sometimes referred to as “organic compound solution”) and a precipitation solvent (hereinafter, referred to as “at least partly diffusible”). In some cases, the compound is precipitated as fine particles. When mixing using the flow path, for example, the organic compound solution and the diffusible solvent can be circulated as a liquid flow in the flow path, and both liquids can be contacted and mixed. At this time, it is preferable to make both into a laminar flow in the flow path, contact each other in the laminar flow process, and contact at the laminar flow interface. Any apparatus may be used as long as it has a channel capable of forming a laminar flow, and the channel is preferably a channel having an equivalent diameter capable of forming a micro reaction field. Here, “circulate in the flow path” means that a long flow path is used and both liquids are circulated in the same direction in the longitudinal direction of the flow path, and droplets and liquid flows are ejected. The collision is not included in the present invention.

In the production method of the present invention, there are (i) an aspect in which the flow path diameter of the flow path is 1 mm or less and fine particle deposition, and (ii) an aspect in which the liquid flow in the flow path is laminar and the fine particle deposition is performed.
First, an aspect in which organic fine particles are deposited through a flow path having an equivalent diameter of 1 mm or less will be described. Equivalent diameter is also called equivalent diameter and is a term used in the field of mechanical engineering. When an equivalent circular pipe is assumed for a pipe having an arbitrary cross-sectional shape (a flow path in the present invention), the diameter of the equivalent circular pipe is referred to as an equivalent diameter. The equivalent diameter (d _eq ) is defined as d _eq = 4 A / p, using A: the cross-sectional area of the pipe, and p: the wet wetting length (circumferential length) of the pipe. When applied to a circular tube, this equivalent diameter corresponds to the circular tube diameter. The equivalent diameter is used to estimate the flow or heat transfer characteristics of the pipe based on the data of the equivalent circular pipe, and represents the spatial scale (typical length) of the phenomenon. The equivalent diameter is d _eq = 4a ² / 4a = a for a regular square tube with one side a, d _eq = a / 3 ^{1/2 for} a regular triangle tube with one side a, and the flow between parallel plates with a channel height h. d _eq = 2h (for example, see “Mechanical Engineering Encyclopedia” edited by the Japan Society of Mechanical Engineers, 1997, Maruzen Co., Ltd.).
In this aspect, the equivalent diameter of the flow path defined above is 1 mm or less.

Next, a mode in which fine particle deposition is performed using a liquid flow in the flow path as a laminar flow will be described.
In general, when water is poured into a pipe and a colored liquid is injected by inserting a thin pipe into the central axis of the pipe, the colored liquid flows as a single line while the flow rate of water is low. Flows straight in parallel to the tube wall. However, when the flow velocity is increased and reaches a certain flow velocity, the water flow suddenly becomes turbulent, and the colored liquid is mixed with the water flow to become a colored flow. The former flow is called laminar flow, and the latter flow is called turbulent flow.
Whether the flow becomes a laminar flow or a turbulent flow depends on whether a Reynolds number, which is a dimensionless number indicating the state of the flow, is below a certain critical value. The smaller the Reynolds number, the easier it is to form a laminar flow. The Reynolds number Re of the flow in the pipe is expressed by the following equation.
Re = D <υ _x > ρ / μ
D is the equivalent diameter of the tube, <υ _x > is the average cross-sectional velocity, ρ is the density of the fluid, and μ is the viscosity of the fluid. As can be seen from this equation, the smaller the equivalent diameter, the smaller the Reynolds number. Therefore, in the case of an equivalent diameter of μm, it becomes easy to form a stable laminar flow. It can also be seen that the liquid physical properties of density and viscosity also affect the Reynolds number, and the smaller the density and the larger the viscosity, the smaller the Reynolds number and the easier it is to form a laminar flow.
The critical Reynolds number (critical Reynolds number)
number). The critical Reynolds number is not always constant, but the next value is the standard.
Re <2300 laminar flow
Re> 3000 Turbulence
3000 ≧ Re ≧ 2300 Transient state In this embodiment, organic fine particles are deposited in the laminar flow according to the above-mentioned definition.

Hereinafter, the preferable embodiment of the manufacturing method of this invention is demonstrated.
As the equivalent diameter of the flow path decreases, the surface area per unit volume (specific surface area) increases, but when the flow path becomes microscale, the specific surface area increases dramatically, and the heat transfer efficiency through the wall of the flow path is Become very expensive. Since the heat transfer time (t) in the fluid flowing through the flow path is expressed by t = d _eq ² / α (α: the thermal diffusivity of the liquid), the heat transfer time becomes shorter as the equivalent diameter becomes smaller. That is, when the equivalent diameter is 1/10, the heat transfer time is 1/100. When the equivalent diameter is microscale, the heat transfer speed is extremely fast.

  That is, since the Reynolds number is small in a micro-size space having an equivalent diameter of microscale, the flow reaction can be performed under stable laminar flow control. Since the interfacial surface area between the laminar flows is very large, it is possible to mix the component molecules at high speed and accurately by molecular diffusion between the interfaces while maintaining the laminar flow. In addition, the use of a channel wall having a large surface area enables precise temperature control and precise control of reaction time by flow rate control of the flow reaction. Therefore, in the present invention, among the channels forming the laminar flow, a microscale channel having an equivalent diameter that is a field capable of highly reaction control as described above is defined as a micro reaction field.

  As shown in the description of the Reynolds number, the formation of a laminar flow is greatly influenced not only by the size of the equivalent diameter but also by the flow conditions including liquid properties such as viscosity and density. In the present invention, in the aspect in which fine particle precipitation is performed under laminar flow, the equivalent diameter of the flow path that can easily form laminar flow is preferable, specifically 10 mm or less, and preferably 1 mm or less. It is more preferable. And including the aspect which microparticles | fine-particles precipitate on the conditions whose equivalent diameter of a flow path is 1 mm or less, it is preferable to set it as 10 micrometers-1 mm, and it is especially preferable to set it as 20-500 micrometers.

  Typical reactors having microscale size channels (channels) are generally referred to as “microreactors” and have recently undergone significant development (eg, W. Ehrfeld, V. Hessel, H. Loewe). , "Microreactor", 1 Ed (2000) WILEY-VCH).

  The general microreactor is provided with a plurality of microchannels having an equivalent diameter of several μm to several hundreds of μm when the cross section is converted into a circle, and a mixing space connected to these microchannels. In such a microreactor, a plurality of solutions are introduced into a mixing space through a plurality of microchannels, thereby mixing the plurality of solutions or causing a chemical reaction with the mixing.

  Next, the main points in which the reaction by the microreactor is different from the batch method using a tank or the like will be described. Liquid-phase chemical reactions and two-phase liquid-phase chemical reactions generally occur when molecules meet at the interface of the reaction solution. The area of the interface increases and the reaction efficiency increases significantly. In addition, the diffusion time of the molecule itself is proportional to the square of the distance. This means that as the scale is reduced, the reaction proceeds more easily due to the diffusion of the molecules without active mixing of the reaction solution, and the reaction tends to occur. In microspaces, the Reynolds number (the dimensionless number that characterizes the flow) is small, so the flow is dominated by laminar flow, and the molecules that exist in each solution at the interface where the solutions are in a laminar flow state. Exchange occurs, and the migrated molecules cause precipitation and reaction.

  When a microreactor having such characteristics is used, the reaction time and temperature between solutions can be precisely controlled as compared with a conventional batch system using a large volume tank or the like as a reaction field. In the case of the batch method, the reaction proceeds at the reaction contact surface at the initial stage of mixing, particularly between solutions with a high reaction rate, and the primary product generated by the reaction between the solutions continues to be reacted in the vessel. Therefore, there is a possibility that the product becomes non-uniform, or the crystal of the product grows more than necessary in the mixing container and becomes coarse. On the other hand, according to the microreactor, the solution continuously circulates with almost no stagnation in the mixing container. Therefore, while the primary product generated by the reaction between the solutions stays in the mixing container, it continues. It is possible to prevent the reaction from occurring, and it is possible to take out a pure primary product that has been difficult to remove in the past, and it is difficult to cause aggregation and coarsening of crystals in the mixing vessel.

  In addition, when a small amount of chemical substances produced by an experimental production facility is manufactured (scaled up) in a large amount by a large-scale production facility, a large-scale batch method is conventionally used. It took a lot of labor and time to obtain reproducibility at the manufacturing equipment, but this was achieved by parallelizing (numbering up) the production lines using microrear coolers according to the required production volume. There is a possibility that labor and time for obtaining such reproducibility can be greatly reduced.

  A method for producing a flow path that can be used in the method for producing an organic fine particle dispersion of the present invention will be described below. When the flow path has a size of 1 mm or more, it can be manufactured relatively easily by using a normal machining technique. However, when the size is 1 mm or less, particularly 500 μm or less, the manufacturing becomes extremely difficult. In many cases, micro-sized flow paths (micro flow paths) are produced on a solid substrate using a microfabrication technique. The substrate material may be anything as long as it is a stable material that does not easily corrode. For example, metal (for example, stainless steel, hastelloy (Ni—Fe alloy), nickel, aluminum, silver, gold, platinum, tantalum, or titanium), glass, plastic, silicone, Teflon (registered trademark), or ceramics.

  Typical examples of microfabrication techniques for producing microchannels include LIGA (Roentgen-Lithographie Galvanik Abforming) technology using X-ray lithography, high aspect ratio photo using EPON SU-8 (trade name). Lithography method, micro electric discharge machining method (μ-EDM (Micro Electro Discharge Machining)), deep RIE (Reactive Ion Etching) silicon high aspect ratio processing method, Hot Emboss processing method, optical modeling method, laser processing method, ion beam Machining methods, and mechanical micro-cutting methods using micro tools made of hard materials such as diamond. These techniques may be used alone or in combination. Preferred microfabrication techniques are LIGA technology using X-ray lithography, high aspect ratio photolithography using EPON SU-8, micro electrical discharge machining (μ-EDM), and mechanical micromachining. In recent years, the application of fine injection molding technology to engineering plastics has been studied.

  Joining techniques are often used when producing microchannels. The usual bonding techniques are roughly divided into solid phase bonding and liquid phase bonding, and the commonly used bonding methods are pressure bonding and diffusion bonding as solid phase bonding, welding, eutectic bonding, soldering as liquid phase bonding, Adhesion or the like is a typical joining method. In addition, during assembly, a highly precise bonding method that maintains dimensional accuracy without deteriorating material due to high temperature heating or destruction of micro structures such as flow paths due to large deformation is desirable. There are bonding, anodic bonding, surface activation bonding, direct bonding using hydrogen bonding, bonding using HF aqueous solution, Au-Si eutectic bonding, void-free bonding, and the like.

  The microchannel is not limited to a microchannel manufactured on a solid substrate using a microfabrication technique, and may be various types of fused silica capillary tubes having an inner diameter of several μm to several hundred μm that can be obtained. Various silicon tubes, fluororesin tubes, stainless steel tubes, PEEK tubes (polyether ether ketone tubes) with an inner diameter of several μm to several hundreds of μm that are commercially available for high-performance liquid chromatographs and gas chromatographs are also used. Is possible.

  So far, microreactors have been reported on devices aimed at improving reaction efficiency. For example, JP2003-210960, JP2003-210963, JP2003-210959, JP2005-46650, JP2005-46651, JP2005-46652, and JP2005-288254 are micromixers and microreactors. The above-mentioned microdevice and the like can also be used.

  The microchannel may be surface-treated according to the purpose. In particular, when an aqueous solution is manipulated, surface treatment is important because adsorption of the sample to glass or silicon may be a problem. It would be desirable to achieve fluid control within a micro-sized channel without incorporating moving parts that require complex fabrication processes. For example, it is possible to create a hydrophilic region and a hydrophobic region by surface treatment in the flow path, and manipulate the fluid by utilizing the difference in surface tension acting on the boundary. As a method for surface treatment of glass or silicon, hydrophobic or hydrophilic surface treatment using a silane coupling agent is frequently used.

  In order to introduce and mix reagents and samples into the flow path, a fluid control function is required. In particular, since the behavior of the fluid in the microchannel has a property different from that of the macroscale, a control method suitable for the microscale must be considered. The fluid control method includes a continuous flow method and a liquid droplet (liquid plug) method in terms of form classification, and an electric drive method and a pressure drive method in terms of drive force classification.

  These methods are described in detail below. The most widely used form for handling fluid is the continuous flow system. In continuous flow type fluid control, the entire microchannel is generally filled with fluid, and the entire fluid is generally driven by a pressure source such as a syringe pump prepared outside. This method has a great advantage that a control system can be realized with a relatively simple setup, although it is difficult to have a large dead volume.

  As a method different from the continuous flow method, there is a droplet (liquid plug) method. In this system, droplets partitioned by air are moved in the reactor or in a flow path leading to the reactor, and each droplet is driven by air pressure. At that time, a vent structure that allows the air between the droplet and the channel wall or between the droplets to escape to the outside as needed, and a valve structure that keeps the pressure in the branched channel independent of other parts Etc. need to be prepared inside the reactor system. Further, in order to control the pressure difference and operate the droplet, it is necessary to construct a pressure control system including a pressure source and a switching valve outside. In this way, the droplet system makes the device configuration and the reactor structure somewhat complicated, but it can be operated in multiple stages, such as operating several droplets individually and sequentially performing several reactions. The degree of freedom of configuration increases.

As a drive method for fluid control, an electric drive method in which an electroosmotic flow is generated by applying a high voltage to both ends of a flow path (channel) and fluid is moved by this, and pressure is applied to the fluid using a pressure source outside. In general, a pressure driving method of moving by applying a pressure is widely used. The difference between the two is that, for example, the behavior of the fluid is a flat distribution when the flow velocity profile is electrically driven in the cross section of the flow path, whereas the center of the flow path is It is known that the wall portion is fast and has a slow distribution, and the electric drive method is more suitable for the purpose of moving the sample plug while keeping the shape of the sample plug or the like. When the electric drive method is used, the flow path needs to be filled with a fluid, so it must be in the form of a continuous flow method, but the fluid can be manipulated by electrical control. Therefore, for example, a relatively complicated process of creating a temporal concentration gradient is realized by changing the mixing ratio of two kinds of solutions continuously. In the case of the pressure drive system, there is almost no influence on the substrate because it can be controlled regardless of the electrical properties of the fluid, and it is not necessary to consider side effects such as heat generation and electrolysis. The application range is wide. On the other hand, it is necessary to automate complicated processes such as having to prepare a pressure source outside and changing the response characteristics of the operation according to the size of the dead volume of the pressure system.
The method used as the fluid control method is appropriately selected according to the purpose, but is preferably a continuous flow type pressure driving method.

  The temperature control in the flow path may be controlled by placing the entire apparatus having the flow path in a temperature-controlled container, or a heater structure such as a metal resistance wire or polysilicon is built in the apparatus for heating. This may be used for cooling, and the cooling may be performed by natural cooling. For temperature sensing, when using a metal resistance wire, it is preferable to create another resistance wire that is the same as the heater, and to detect the temperature based on the change in the resistance value. When using polysilicon, Detection is preferably performed using a thermocouple. Moreover, you may heat and cool from the outside by making a Peltier device contact a flow path. Which method is used is selected in accordance with the application and the material of the flow path body.

  When the fine particles are deposited in the flow process in the flow path, the reaction time can be controlled by the time spent in the flow path. The residence time is determined by the length of the flow path and the introduction speed of the reaction solution when the equivalent diameter is constant. Although there is no restriction | limiting in particular in the length of a flow path, Preferably they are 1 mm or more and 10 m or less, More preferably, they are 5 mm or more and 10 m or less, Especially preferably, they are 10 mm or more and 5 m or less.

  In the method for producing an organic fine particle dispersion of the present invention, the number of flow paths to be used is not particularly limited and may be appropriately determined, and may be one. However, if necessary, a number of flow paths may be arranged in parallel (numbering). Increase the amount of processing.

  In a microreactor, a device specialized for mixing is called a micromixer. Various devices have been developed due to the difference in the concept of the mixed mode. For example, W.W. Ehrfeld, V.M. Hessel, H.C. Loewe, “Microreactors”, 1 Ed. (2000), WILEY-VCH. Chapter 3 (pages 41-85) provides details on "Micromixer". In the present invention, an organic fine particle dispersion can be suitably produced according to these devices and the mixing mode. Many of these utilize the phenomenon of substance diffusion between the fluids to be mixed, and it is necessary to increase the contact area of the fluid to be mixed in order to perform it quickly and uniformly. Furthermore, in Japanese Patent Application Laid-Open No. 2005-288254, compared to the conventional type, a new mixing concept corresponding to quick and uniform mixing performance improvement, easy application of various operating conditions of mixing, blockage suppression, and stable continuous operation. A micromixer in which is introduced is disclosed. The performance of micromixers based on this concept has been reported (H. Nagasawa, N. Aoki and K. Mae, “Design of a New Mixer for Instant Mixing on the Coll. Of T. Mig. , 28, No. 3, pp. 324, 2005.). According to this, it has been shown that fluid mixing takes place very quickly with the new device of this concept. The device used in the present invention is not particularly limited, but the above-described new reactor is preferably used.

  In the present invention, when the liquid stream of the solution in which the organic compound is dissolved in the solvent and the liquid stream of the precipitation solvent are combined and mixed, at least one liquid stream is divided into a plurality of divided liquid streams, It is preferable that the central axis of at least one of the plurality of divided liquid streams and the central axis of the other liquid stream are merged and mixed so as to intersect at one point in the merge region, It is more preferable that the plurality of divided divided liquid streams circulate through a flow path extending radially from the central merge area toward the central merge area and be mixed and mixed.

  A reaction apparatus preferably used in the method for producing an organic fine particle dispersion of the present invention is shown in FIGS. Needless to say, the present invention is not limited to these examples.

  1-1 is explanatory drawing of the reactor 10 which has a Y-shaped flow path, FIG. 1-2 is sectional drawing of the II line | wire. The shape of the cross section orthogonal to the length direction of the flow path varies depending on the microfabrication technique used, but is preferably a trapezoidal or rectangular shape. Moreover, it is preferable that the flow path width C and the depth H are micrometer size. The solution injected from the introduction port 11 and the introduction port 12 by a pump or the like is contacted at the fluid confluence 13d via the introduction channel 13a or the introduction channel 13b, and preferably forms a stable laminar flow. It flows through the flow path 13c. While flowing as a laminar flow, the solutes contained in the liquids are mixed by molecular diffusion at the interface between the laminar flows, and the reaction can proceed. In the case of a solute with extremely slow diffusion, there is a case where diffusion mixing between laminar flows does not occur and mixing is performed only after reaching the discharge port 14. When the two liquids to be injected are easily mixed in the flask, if the flow path length F is long, the liquid flow can be uniform at the outlet, but when the flow path length F is short, Laminar flow is maintained up to the outlet. When the two solutions to be injected do not mix in the flask and are separated into layers, the two liquids can flow as a laminar flow and reach the outlet 14.

  FIG. 2-1 is an explanatory view of the reaction apparatus 20 having a cylindrical tube-type flow path provided with a flow path inserted on one side, and FIG. 2-2 is a cross-sectional view of the apparatus taken along line IIa-IIa. -3 is a sectional view taken along line IIb-IIb of the apparatus. The shape of the cross section perpendicular to the length direction of the flow path is preferably a circle or a shape close thereto. At this time, the flow path diameter (D, E) of the cylindrical tube is preferably a micrometer size. The liquid injected from the introduction port 21 and the introduction port 22 by a pump or the like comes into contact at the fluid confluence 23d through the introduction channel 23a and the introduction channel 23b, and preferably forms a stable cylindrical laminar flow. 23c. The solute contained in each laminar flow is mixed by molecular diffusion at the interface between the laminar flows while flowing as a cylindrical laminar flow, and the reaction can proceed in the same manner as in the apparatus of FIG. 1-1. Compared with the device shown in FIG. 1-1 above, the present device having a cylindrical channel has a larger contact interface between the two liquids, and further, there is no portion where the contact interface contacts the device wall surface. The feature is that there is no crystal growth from the contact portion with the wall surface, such as when it is generated by reaction, and the possibility of blocking the flow path is low.

  FIGS. 3-1 and 4 are modifications of the apparatus of FIGS. 1-1 and 2-1 so that when the two liquid flows reach the outlet in a laminar flow, they can be separated. When these devices are used, reaction and separation can be performed simultaneously. Moreover, it can be avoided that the two liquids are finally mixed and the reaction proceeds too much or the crystal becomes coarse. When a product or a crystal is selectively present in one liquid, the product or the crystal can be obtained at a higher concentration than when the two liquids are mixed. In addition, by connecting several of these devices, there is an advantage that the extraction operation is performed efficiently.

The microreactor apparatus 50 shown in FIG. 5 supplies a single liquid A (in the figure, the liquid is indicated by an arrow indicating the direction of the flow. The same applies to the liquids B and C). Two divided supply channels 51A and 51B that are branched from the middle of the supply channel 51 so that the liquid A can be divided into two, and one undivided supply channel 52 that supplies the liquid B The micro flow channel 53 that performs the reaction between the solution A and the solution B is formed so as to communicate with each other in one merging region 54. The divided supply channels 51A and 51B, the supply channel 52, and the microchannel 53 are arranged at equal intervals of 90 ° around the merging region 54 in substantially the same plane. That is, the central axes (one-dot chain lines) of the flow paths 51A, 51B, 52, and 53 intersect in a cross shape (intersection angle α = 90 °) in the merge region 54. In FIG. 5, only the supply path 51 for the liquid A is divided so that the supply amount can be increased as compared with the liquid B, but the supply path 52 for the liquid B may also be divided into a plurality. Further, the intersection angle α of the flow paths 51A, 51B, 52, 53 arranged around the merging region 54 is not limited to 90 ° and can be set as appropriate. Further, the number of divisions of the supply channels 51 and 52 is not particularly limited, but when the number is too large and the structure of the microreactor device 50 is complicated, the number of divisions is preferably 2 to 10. 2 to 5 is more preferable.
FIG. 6 shows another embodiment of the planar microreactor apparatus shown in FIG. 5. The crossing angle β formed by the central axes of the divided supply channels 61A and 61B with respect to the central axis of the supply channel 62 is 90 in FIG. It is formed at 45 ° smaller than °. Further, the crossing angle α formed by the central axis of the micro flow path 63 with respect to the central axis of the divided supply flow paths 61A and 61B is set to 135 °.
FIG. 7 shows still another aspect of the planar microreactor apparatus of FIG. 5, in which the central axis of the divided supply channels 71A and 71B in which the liquid A flows with respect to the central axis of the supply channel 72 in which the liquid B flows. The formed crossing angle β is set to 135 ° larger than 90 ° in FIG. Further, the crossing angle α formed by the central axis of the micro flow path 73 with respect to the central axis of the divided supply flow paths 71A and 71B is 45 °. The crossing angles α and β of the supply flow path 72, the divided supply flow paths 71A and 71B, and the micro flow path 73 can be set as appropriate, but the cross-sectional area in the thickness direction of all of the merged liquid B and liquid A The crossing angles α and β are preferably set so that S1> S2 is satisfied, where S1 is S1 and the radial cross-sectional area of the microchannel 73 is S2. This is because the contact area between the liquids A and B can be further increased and the diffusion mixing distance can be further reduced, so that instantaneous mixing is more likely to occur.
FIG. 8 shows an embodiment of a three-dimensional microreactor device, and is an exploded perspective view schematically showing three parts constituting the microreactor device 80 in an exploded manner. The three-dimensional microreactor apparatus 80 of this embodiment is mainly configured by a supply block 81, a merge block 82, and a reaction block 83 each having a cylindrical shape. In order to assemble the microreactor device 80, the cylindrical blocks 81, 82, 83 are made to be cylindrical by aligning the side surfaces with each other in this order. For example, each block is bolted in this state.・ Tighten together with nuts.
Two annular grooves 85, 86 are formed concentrically on the side surface 84 of the supply block 81 that faces the merging block 82. When the microreactor device 80 is assembled, the two annular grooves 86, Reference numeral 85 denotes a ring-shaped channel through which the liquid B and the liquid A flow. And the through-holes 88 and 87 which reach the outer side annular groove 86 and the inner side annular groove 85 from the opposite side surface 94 which does not oppose the confluence | merging block 82 of the supply block 81 are formed, respectively. Of the two through holes 88, 87, the through hole 88 communicating with the outer annular groove 86 is connected to supply means (a pump, a connection tube, etc.) for supplying the liquid A, and communicates with the inner annular groove 85. A supply means (a pump, a connection tube, etc.) for supplying the liquid B is connected to the through hole 87. In FIG. 8, the liquid A is allowed to flow in the outer annular groove 86 and the liquid B is allowed to flow in the inner annular groove 85, but the reverse may be possible.
A circular confluence 90 is formed at the center of the side surface 89 of the confluence block 82 facing the reaction block 83, and four long radial grooves 91 and four short radial grooves 92 are formed radially from the confluence 90. Alternately drilled. These merging holes 90 and radial grooves 91 and 92 form a circular space serving as a merging region 90 and radial flow channels through which liquids A and B flow when the microreactor device 80 is assembled. Further, among the eight radial grooves 91, 92, through holes 95 are formed in the thickness direction of the merge block 82 from the tip of the long radial groove 91, and these through holes 95 are formed in the supply block 81. It communicates with the outer annular groove 86 described above. Similarly, through holes 96 are formed in the thickness direction of the merging block 82 from the tips of the short radial grooves 92, and these through holes 96 communicate with an inner annular groove 85 formed in the supply block 81.
Further, at the center of the reaction block 83, one through hole 93 communicating with the merging portion 90 in the thickness direction of the reaction block 83 is formed, and this through hole 93 serves as a micro flow path.
Thereby, the liquid A flows from the through hole 88 of the supply block 81 through the outer annular groove 86, through the through hole 95 of the merge block 82, and through the supply flow path of the long radiation groove 91. The four divided flows reach the merging portion 90. On the other hand, the liquid B flows from the through hole 87 of the supply block 81 through the inner annular groove 85, through the through hole 96 of the confluence block 82, and through the supply flow path of the short radiation groove 92. The four divided flows reach the merging portion 90. After the split flow of the liquid A and the split flow of the liquid B merge with their kinetic energy in the merge section 90, the flow direction changes by 90 ° and flows into the microchannel 93.

  Any of the devices shown in FIGS. 1 to 8 can be preferably used in the present invention. Among them, the device having the concept shown in FIGS. 5 to 8 is preferably used, and the device having the concept shown in FIG. 8 is used. It is more preferable. Thereby, particularly in the production method of the present invention, the rapid mixing performance of the organic pigment solution and the precipitation medium when depositing the fine particles in the presence of the polymerizable compound is excellent, and when the polymerizable compound is polymerized and immobilized. The dispersion stability and storage stability of the organic fine particles are further increased. Further, since the blockage of the flow path is suppressed or prevented, the production stability is high, and the numbering up suitability is excellent, which is particularly preferable for producing the organic fine particle dispersion of the present invention.

The organic compound used in the production method of the present invention has a low solubility in a precipitation solvent, and is preferably separated and precipitated from a solution dissolved as a liquid or solid by mixing with these, and more preferably separated into a solid. . The organic compound used in the production method of the present invention may be polymerized by the polymerization treatment of the present invention or may not be polymerized. A compound that is polymerized by polymerization treatment is preferred, but in this case, the precipitated organic fine particles are firmly fixed, and it can be expected that stability is improved. Further, it is preferably a compound that is expected to exhibit a size effect when it is made into fine particles. Although there is no particular limitation, organic electronic materials (charge transfer agents, nonlinear optical materials, etc.), functional organic dye compounds (organic pigments, sensitizing dyes, photoelectric conversion dyes, optical recording dyes, image recording) Dyes, coloring dyes, etc.), pharmaceutical-related compounds (pharmaceuticals, agricultural chemicals, analytical agents, diagnostic agents, dietary supplements, etc.), among others, charge transport agents, organic pigments, dyes for optical recording, for image recording Dyes and coloring dyes are preferable, and organic dye compounds such as optical recording dyes, image recording dyes, and coloring dyes are more preferable. When classified from the structure, these organic compounds are not limited to single molecules, but may be oligomers or polymers having repeating units of different or similar molecular bonds in the molecular structure. Further, it may be an organic-inorganic or organic-metal hybrid compound.
In addition, since the fine particles obtained by the production method of the present invention have the same size, the solubility in a solvent is improved, the temperature during dissolution can be lowered, and the time required for dissolution can be shortened. As a result, it is preferable because the organic compound can be prevented from being thermally decomposed in the dissolving step.

  Specific examples of the charge transfer agent used in the production method of the present invention are shown below, but the present invention is not limited thereto.

  Specific examples of the dye for optical recording used in the production method of the present invention are shown below, but the present invention is not limited thereto.

  The organic pigment used in the present invention is not limited in hue, and may be a magenta pigment, a yellow pigment, or a cyan pigment. Specifically, for example, perylene, perinone, quinacridone, quinacridonequinone, anthraquinone, anthanthrone, benzimidazolone, disazo condensation, disazo, azo, indanthrone, phthalocyanine, triarylcarbonium, dioxazine, aminoanthraquinone, diketopyrrolopyrrole, Magenta pigments such as thioindigo, isoindoline, isoindolinone, pyranthrone or isoviolanthrone pigments or mixtures thereof, yellow pigments, or cyan pigments.

  More specifically, for example, C.I. I. Pigment red 190 (C.I. No. 71140), C.I. I. Pigment red 224 (C.I. No. 71127), C.I. I. Perylene pigments such as CI Pigment Violet 29 (C.I. No. 71129); I. Pigment orange 43 (C.I. No. 71105), or C.I. I. Perinone pigments such as CI Pigment Red 194 (C.I. No. 71100); I. Pigment violet 19 (C.I. No. 73900), C.I. I. Pigment violet 42, C.I. I. Pigment red 122 (C.I. No. 73915), C.I. I. Pigment red 192, C.I. I. Pigment red 202 (C.I. No. 73907), C.I. I. Pigment Red 207 (C.I. No. 73900, 73906) or C.I. I. Pigment Red 209 (C.I. No. 73905), a quinacridone pigment, C.I. I. Pigment red 206 (C.I. No. 73900/73920), C.I. I. Pigment orange 48 (C.I. No. 73900/73920), or C.I. I. Quinacridone quinone pigments such as CI Pigment Orange 49 (C.I. No. 73900/73920); I. Anthraquinone pigments such as CI Pigment Yellow 147 (C.I. No. 60645); I. Anthanthrone pigments such as CI Pigment Red 168 (C.I. No. 59300); I. Pigment brown 25 (C.I. No. 12510), C.I. I. Pigment violet 32 (C.I. No. 12517), C.I. I. Pigment yellow 180 (C.I. No. 21290), C.I. I. Pigment yellow 181 (C.I. No. 11777), C.I. I. Pigment orange 62 (C.I. No. 11775), or C.I. I. Benzimidazolone pigments such as CI Pigment Red 185 (C.I. No. 12516); I. Pigment yellow 93 (C.I. No. 20710), C.I. I. Pigment yellow 94 (C.I. No. 20038), C.I. I. Pigment yellow 95 (C.I. No. 20034), C.I. I. Pigment yellow 128 (C.I. No. 20037), C.I. I. Pigment yellow 166 (C.I. No. 20035), C.I. I. Pigment orange 34 (C.I. No. 21115), C.I. I. Pigment orange 13 (C.I. No. 21110), C.I. I. Pigment orange 31 (C.I. No. 20050), C.I. I. Pigment red 144 (C.I. No. 20735), C.I. I. Pigment red 166 (C.I. No. 20730), C.I. I. Pigment red 220 (C.I. No. 20055), C.I. I. Pigment red 221 (C.I. No. 20065), C.I. I. Pigment red 242 (C.I. No. 20067), C.I. I. Pigment red 248, C.I. I. Pigment red 262, or C.I. I. Disazo condensation pigments such as CI Pigment Brown 23 (C.I. No. 20060); I. Pigment yellow 13 (C.I. No. 21100), C.I. I. Pigment yellow 83 (C.I. No. 21108), or C.I. I. Disazo pigments such as CI Pigment Yellow 188 (C.I. No. 21094); I. Pigment red 187 (C.I. No. 12486), C.I. I. Pigment red 170 (C.I. No. 12475), C.I. I. Pigment yellow 74 (C.I. No. 11714), C.I. I. Pigment red 48 (C.I. No. 15865), C.I. I. Pigment red 53 (C.I. No. 15585), C.I. I. Pigment orange 64 (C.I. No. 12760), or C.I. I. Azo pigments such as C.I. Pigment Red 247 (C.I. No. 15915), C.I. I. Indanthrone pigments such as CI Pigment Blue 60 (C.I. No. 69800); I. Pigment green 7 (C.I. No. 74260), C.I. I. Pigment Green 36 (C.I. No. 74265), Pigment Green 37 (C.I. No. 74255), Pigment Blue 16 (C.I. No. 74100), C.I. I. Phthalocyanine pigments such as CI Pigment Blue 75 (C.I. No. 74160: 2) or 15 (C.I. No. 74160); I. Pigment blue 56 (C.I. No. 42800), or C.I. I. Triarylcarbonium pigments such as CI Pigment Blue 61 (C.I. No. 42765: 1); I. Pigment violet 23 (C.I. No. 51319) or C.I. I. Dioxazine pigments such as CI Pigment Violet 37 (C.I. No. 51345); I. Aminoanthraquinone pigments such as CI Pigment Red 177 (C.I. No. 65300); I. Pigment red 254 (C.I. No. 56110), C.I. I. Pigment Red 255 (C.I. No. 561050), C.I. I. Pigment red 264, C.I. I. Pigment red 272 (C.I. No. 561150), C.I. I. Pigment orange 71, or C.I. I. Diketopyrrolopyrrole pigments such as C.I. Pigment Orange 73; I. Thioindigo pigments such as CI Pigment Red 88 (C.I. No. 7313), C.I. Pigment Yellow 139 (C.I. No. 56298), C.I. I. Pigment Orange 66 (C.I. No. 48210) and the like, isoindoline pigments such as C.I. I. Pigment yellow 109 (C.I. No. 56284), or C.I. Pigment Orange 61 (C.I. No. 11295) and the like, isoindolinone pigments such as C.I. I. Pigment Orange 40 (C.I. No. 59700), or C.I. I. Pyranthrone pigments such as CI Pigment Red 216 (C.I. No. 59710), or C.I. I. It is an isoviolanthrone pigment such as CI Pigment Violet 31 (60010).

  Preferred pigments are quinacridone, diketopyrrolopyrrole, disazo condensation pigments, or phthalocyanine pigments, and particularly preferred are quinacridone, disazo condensation pigments, or phthalocyanine pigments.

  Next, the organic dye compound for coloring used in the production method of the present invention includes a reactive dye which is a hydrophobic dye, an azoic dye, a fluorescent dye, a disperse dye, a styrene dye, an acid dye, a metal-containing dye, and an acid mordant. Examples thereof include dyes, direct dyes, cationic dyes, basic dyes, sulfur dyes, and oil-soluble dyes.

Although the specific example of the coloring pigment | dye used for the manufacturing method of this invention is shown below, this invention is not limited to these.

  In the method for producing an organic fine particle dispersion of the present invention, the organic compound solution and the precipitation solvent are contacted and mixed using a flow path. At this time, the organic compound solution is uniformly dissolved in a solvent (hereinafter, a solvent that dissolves the organic compound is also referred to as “good solvent”). When the suspension is added, the particle size may increase or the organic particles may have a wide particle distribution, which may block the flow path. In the present invention, “uniformly dissolved” includes residues and precipitates corresponding to a solution obtained through a microfilter of 1 μm or less (that is, a solution that does not contain residues when filtered through the same filter). This refers to a dissolved state in which almost no turbidity is observed when observed under visible light. An additive may be used when the organic compound is uniformly dissolved.

Although the good solvent varies depending on the organic compound, it is preferable to use a polar solvent. Specifically, a fluorine-based alcohol (2,2,3,3-tetrafluoro-1-propanol, etc.), an amide-based solvent (dimethylformamide, dimethyl) Acetamide, N-methylpyrrolidone, 1,3-dimethyl-2-imidazolidinone, etc., carboxylic acid solvents (formic acid, acetic acid, etc.), sulfonic acid solvents (methanesulfonic acid, etc.), sulfur solvents (dimethyl sulfoxide, Examples include sulfolane and the like, ether solvents (such as tetrahydrofuran), halogen solvents (such as chloroform and dichloromethane), and ionic liquids (such as 1-butyl-3-methylimidazolium tetrafluoroborate). Of these, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, and dimethylsulfoxide are preferably used, and dimethylacetamide, N-methylpyrrolidone, and dimethylsulfoxide are more preferably used. These good solvents may be used alone or in combination.
The amount of the good solvent used is an amount capable of uniformly dissolving the organic compound, and is not particularly limited, but is preferably 10 to 500 times by mass ratio, preferably 20 to 100 times the organic compound. Amount.

Next, a precipitation solvent (hereinafter also referred to as a precipitation solvent) to be brought into contact with the organic compound solution will be described.
The kind of the precipitation solvent is determined by the above-mentioned good solvent, the kind of the organic compound, etc., and it is difficult to uniquely determine by itself. However, the precipitation solvent is preferably a poor solvent for an organic compound dissolved in a good solvent, and the solubility of the organic compound is preferably a solvent having a solubility of 0.1 or less. The combination of the good solvent and the precipitation solvent is preferably a combination in which the good solvent is a solvent having an organic compound solubility of 1 or more and the precipitation solvent is a solvent having an organic compound solubility of 0.1 or less (the solubility is in a saturated solution). The concentration of the solute in 100 g is expressed in terms of the amount of solute in 100 g of solution (in grams).
In the present invention, at least a part of the precipitation solvent can diffuse into the good solvent. In the present invention, “at least a part can be diffused” means that the dissolution amount when both solutions are vigorously stirred in a beaker and allowed to stand for 24 hours or more is 10% by mass or more of the precipitation solvent. In addition, it is preferable that it melt | dissolves uniformly at this time, and it is preferable that a deposit and a precipitate do not arise. In the production method of the present invention, as described above, the precipitation solvent has a compatibility of uniformly mixing 10% by mass or more with respect to the good solvent, but preferably has a compatibility capable of mixing 50% by mass or more. It is more preferable that they are compatible so that they can be mixed infinitely.

Regarding the combination of a good solvent and a precipitation solvent, for example, when the good solvent is a halogen solvent, the precipitation solvent is a hydrocarbon solvent (such as n-hexane or toluene), or an ester solvent (such as ethyl acetate) as the precipitation solvent. Function as.
The precipitation solvent is preferably an aqueous medium, an alcohol solvent, or a hydrocarbon solvent, although it depends on the combination with a good solvent.
The precipitation solvents may be used alone or in combination. The organic compound solution and the precipitation solvent may contain an inorganic or organic salt, acid, alkali, or the like as necessary.

  The mixing ratio of the organic compound solution and the precipitation solvent varies depending on the type of organic compound to be finely divided, the desired fine particle size, etc., but the precipitation solvent / organic compound solution (mass ratio) is preferably 0.01-100. 0.05 to 10 is more preferable. When mixing in the flow path, the ratio of the flow rates of the two liquids is preferably in the above range.

  In the present invention, an aqueous medium can be used as a precipitation solvent or a good solvent. In the present invention, the aqueous medium refers to water alone or a mixed solvent of water-soluble organic solvents. The organic solvent used at this time is, for example, (a) when water alone is insufficient to uniformly dissolve the organic compound or dispersant, and (b) obtains a viscosity necessary for circulation in the flow path. However, when water alone is insufficient, (c) it is preferably used when necessary for forming a laminar flow. In many cases, an organic compound or the like can be uniformly dissolved by using an aqueous medium to which a water-soluble organic solvent is added.

  Examples of the organic solvent to be added include ethylene glycol, propylene glycol, diethylene glycol, polyethylene glycol, thiodiglycol, dithiodiglycol, 2-methyl-1,3-propanediol, 1,2,6-hexanetriol, acetylene glycol derivatives, Polyhydric alcohol solvents such as glycerin or trimethylolpropane, polyhydric alcohols such as ethylene glycol monomethyl (or ethyl) ether, diethylene glycol monomethyl (or ethyl) ether, or triethylene glycol monoethyl (or butyl) ether Lower monoalkyl ether solvents, ethylene glycol dimethyl ether (monoglyme), diethylene glycol dimethyl ether (diglyme), or trie Polyether solvents such as lenglycol dimethyl ether (triglyme), dimethylformamide, dimethylacetamide, 2-pyrrolidone, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, urea, tetramethylurea, etc. Amide solvents, sulfur-containing solvents such as sulfolane, dimethyl sulfoxide, or 3-sulfolene, polyfunctional solvents such as diacetone alcohol and diethanolamine, acetic acid, maleic acid, docosahexaenoic acid, trichloroacetic acid, or trifluoroacetic acid. Examples thereof include carboxylic acid solvents, methanesulfonic acid, and sulfonic acid solvents such as trifluorosulfonic acid. Two or more of these solvents may be mixed and used.

  The temperature at which the organic fine particles are precipitated is preferably within a range where the solvent does not solidify or vaporize, but is preferably -20 to 90 ° C, more preferably 0 to 50 ° C. Especially preferably, it is 5-15 degreeC.

  The fluid velocity (flow rate) in the flow path is preferably 0.1 mL to 300 L / hr, more preferably 0.2 mL to 30 L / hr, still more preferably 0.5 mL to 15 L / hr, and 1.0 mL to 6 L / hr. hr is particularly preferred.

  In the method for producing an organic fine particle dispersion of the present invention, it is preferable to contain a polymerizable compound in at least one of the organic compound solution and the precipitation solvent, and a dispersant may be added. The polymerizable compound or / and the dispersant have the action of (1) quickly adsorbing on the surface of the deposited organic fine particles to form fine particles, and (2) preventing these particles from aggregating again. It is preferable. As the dispersant, anionic, cationic, amphoteric, nonionic, low molecular or high molecular dispersants can be used. These dispersants can be used alone or in combination.

  Examples of anionic dispersants (anionic surfactants) include N-acyl-N-alkyl taurine salts, fatty acid salts, alkyl sulfate esters, alkyl benzene sulfonates, alkyl naphthalene sulfonates, dialkyl sulfosuccinates, alkyl phosphorus Examples include acid ester salts, naphthalene sulfonic acid formalin condensate, polyoxyethylene alkyl sulfate ester salts, and the like. Especially, these anionic dispersing agents can be used individually or in combination of 2 or more types.

  Cationic dispersants (cationic surfactants) include quaternary ammonium salts, alkoxylated polyamines, aliphatic amine polyglycol ethers, aliphatic amines, diamines and polyamines derived from aliphatic amines and fatty alcohols, fatty acids And imidazolines derived from these and salts of these cationic substances. These cationic dispersants can be used alone or in combination of two or more.

  The amphoteric dispersant is a dispersant having both an anion group part in the molecule of the anionic dispersant and a cationic group part in the molecule of the cationic dispersant.

  Nonionic dispersants (nonionic surfactants) include polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylamine, Examples thereof include glycerin fatty acid esters. Of these, polyoxyethylene alkylaryl ether is preferable. These nonionic dispersants can be used alone or in combination of two or more.

  Specifically, as the polymer dispersant, polyvinyl pyrrolidone, polyvinyl alcohol, polyvinyl methyl ether, polyethylene oxide, polyethylene glycol, polypropylene glycol, polyacrylamide, vinyl alcohol-vinyl acetate copolymer, polyvinyl alcohol-partial formalized product, Polyvinyl alcohol-partially butyralized product, vinyl pyrrolidone-vinyl acetate copolymer, polyethylene oxide / propylene oxide block copolymer, polyacrylate, polyvinyl sulfate, poly (4-vinylpyridine) salt, polyamide, polyallylamine salt, Condensed naphthalene sulfonate, styrene-acrylate copolymer, styrene-methacrylate copolymer, acrylate ester-acrylate copolymer, acrylate ester Methacrylate copolymer, methacrylate ester-acrylate copolymer, methacrylate ester-methacrylate copolymer, styrene-itaconate copolymer, itaconate-itaconate copolymer, vinyl Examples thereof include naphthalene-acrylate copolymer, vinyl naphthalene-methacrylate copolymer, vinyl naphthalene-itaconate copolymer, cellulose derivative, starch derivative and the like. In addition, natural polymers such as alginate, gelatin, albumin, casein, gum arabic, tonganto gum and lignin sulfonate can also be used. Of these, polyvinylpyrrolidone is preferable. These polymers can be used alone or in combination of two or more.

When the polymer dispersant used in the production method of the present invention is a copolymer, a block copolymer compound consisting of several segments is preferred. In general, acrylic, methacrylic, polyoxyethylene, polyoxyalkylene, polystyrene and other addition polymerization or condensation polymerization block copolymers are known, but in particular, the same or different hydrophobicity. An amphiphilic polymer comprising a combination of a block and a hydrophilic block is more preferable. The number of these hydrophilic and hydrophobic blocks to be combined is not limited, but at least one of each of hydrophilic and hydrophobic blocks is included. Examples of the functional group contained in the hydrophilic block include a carboxylic acid group, a sulfonic acid group, a phosphoric acid group, a hydroxyl group, and an alkylene oxide, and those containing at least one of these are preferable. A carboxylic acid group, a sulfonic acid group, and a hydroxyl group are more preferable, a carboxylic acid group and a hydroxyl group are more preferable, and a carboxylic acid group is particularly preferable. Thereby, the role of the adsorption site to the organic fine particles and the function of strengthening the dispersion stability due to steric repulsion and / or charge repulsion can be imparted to the dispersant. One or more of these block copolymer compounds may be used in combination.
In the present invention, it is preferable to use at least one of the polymerizable compound and the block copolymer compound in combination. Thereby, it is possible to fix the organic compound fine particles more strongly when forming the organic compound fine particles, and it can be expected that the dispersion stability is remarkably improved.

  For the organic fine particles in the dispersion produced by the production method of the present invention, a polymer of a polymerizable compound is immobilized on the fine particles. In the present invention, “immobilization” refers to a state in which all (or part of) the polymerizable compound contained is in contact with the fine particles alone (or in a copolymerized state). At this time, the polymer may be present either on the surface of the fine particles or inside the fine particles, as long as all of the polymer (or a part thereof) is in contact with the fine particles. It is preferable that they are bonded so as not to be detached even if they are moved. Here, the polymer means a compound produced as a result of polymerization of two or more molecules of the polymerizable compound, and it is not necessary that all the polymerizable compounds on the fine particles are involved in the polymerization reaction. It may remain.

  As the polymerizable compound, any of water-soluble and water-insoluble polymerizable compounds can be used. Although it will not specifically limit if it can disperse | distribute with an organic fine particle, It is preferable that a polymeric compound is an ethylenically unsaturated monomer. Specifically, for example, (meth) acrylic acid esters (for example, methyl acrylate, ethyl acrylate, butyl acrylate, benzyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, cyclohexyl acrylate, methyl methacrylate, Ethyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, cyclohexyl methacrylate, ethyl β-hydroxyacrylate, propyl γ-aminoacrylate, propyl γ-hydroxyacrylate, δ-hydroxy Butyl acrylate, β-hydroxyethyl methacrylate, stearyl methacrylate, dimethylaminoethyl methacrylate, diethylene glycol methyl methacrylate, ethylene glycol dimethacrylate, Tetraethylene glycol dimethyl methacrylate and the like and derivatives thereof), vinyl aromatic monomers (for example, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, p-ethylstyrene, p-butylstyrene, p-t-butylstyrene, p-hexylstyrene, p-octylstyrene, p-nonylstyrene, p-decylstyrene, p-dodecylstyrene, 2,4 -Dimethylstyrene, 3,4-dichlorostyrene, α-methylstyrene, divinylbenzene, divinylnaphthalene, etc., and derivatives thereof), vinyl esters (vinyl acetate, vinyl propionate, vinyl benzoate, etc., and derivatives thereof), N-vinylamides (eg N-vinylpyrrolide) ), (Meth) acrylic amides, alkyl-substituted (meth) acrylamides, methacrylamides, N-substituted maleimides, vinyl ethers (vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl phenyl ether, divinyl ether, etc. , And derivatives thereof), olefins (ethylene, propylene, isobutylene, 1-butene, 1-pentene, 4-methyl-1-pentene, butadiene, isoprene, chloroprene, etc., and derivatives thereof) diallyl phthalate, maleic anhydride, (Meth) acrylonitrile, methyl vinyl ketone, vinylidene chloride and the like can be used.

  Furthermore, a water-soluble monomer having an anionic group such as a sulfonic acid group, a phosphoric acid group, and a carboxylic acid group is also used. For example, acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, p-vinylbenzoic acid Examples thereof include monomers having a carboxyl group such as acids, or alkali metal salts, alkaline earth metal salts, ammonium salts, amine salts thereof, and the like. Specific examples are styrene sulfonic acid, sodium styrene sulfonate, 2-acrylamido-2-methylpropane sulfonic acid, 2-hydroxymethyl methacryloyl phosphate, 2-hydroxyethyl methacryloyl phosphate, and 3-chloro-2-hydroxypropyl methacryloyl phosphate. As mentioned. These may be used alone or in combination with each other.

Among the polymerizable compounds, those in which the molecule has a hydrophilicity / hydrophobic function separated are called polymerizable surfactants, reactive surfactants, or reactive emulsifiers. It can use preferably for a manufacturing method. For example, α, β-ethylenically unsaturated group such as vinyl group, allyl group, propenyl group, (meth) acryloyl group and ion dissociable group such as sulfonic acid group or salt thereof, and hydrophilic group such as alkyleneoxy group The thing which has is mentioned. These are generally used for emulsion polymerization, and are anionic, cationic or nonionic surfactants having at least one unsaturated bond capable of radical polymerization in the molecule.
In the method for producing an organic fine particle dispersion of the present invention, the polymerizable surfactant may be used alone, in combination with a different one, or with a polymerizable compound other than the polymerizable surfactant. Preferable polymerizable surfactants include, for example, Kao Corporation, Sanyo Chemical Co., Ltd., Daiichi Kogyo Seiyaku Co., Ltd., Asahi Denka Kogyo Co., Ltd., Nippon Emulsifier Co., Ltd., Nippon Oil & Fats. Examples are commercially available from Co., Ltd., etc., described in “Cutting-edge Technology of Fine Particles / Powder, Chapter 1, Fine Particle Design Using Reactive Emulsifiers, pp23-31”, 2000 CMC Co., Ltd. And the like.

  Specific examples of the polymerizable surfactant are described below, but the present invention is not limited thereto.

  The polymerization method of the polymerizable compound used in the method for producing the organic fine particle dispersion of the present invention is not particularly limited as long as it is a method capable of polymerization in the organic fine particle dispersion, but polymerization is performed by generating radicals using a polymerization initiator. The method of making it preferable is. Although there are various triggers for initiating polymerization, it is preferable to use heat, light, ultrasonic waves, microwaves, or the like. The polymerization initiator is not particularly limited as long as it can polymerize a polymerizable compound, but is an inorganic system represented by a water-soluble or oil-soluble azo polymerization initiator, a polymer azo polymerization initiator, and a persulfate. Salts and peroxides are preferably used. Among these, water-soluble azo polymerization initiators, polymer azo polymerization initiators, and inorganic salts are more preferable, inorganic salts and polymer azo polymerization initiators are more preferable, and polymer azo polymerization initiators are particularly preferable. Specifically, as the inorganic salt, ammonium persulfate, potassium persulfate, sodium persulfate, as the peroxide, hydrogen peroxide, t-butyl hydroperoxide, benzoyl peroxide (BPO), etc. are oil-soluble. As the azo polymerization initiator, 2,2′-azobisisobutyronitrile (AIBN), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile); V-70 (Wako Pure Chemical Industries, Ltd.) Company [trade name]), 2,2′-azobis (2,4-dimethylvaleronitrile); V-65 (manufactured by Wako Pure Chemical Industries, Ltd. [trade name]), dimethyl 2,2′-azobis (2 -Methylpropionate); V-601 (Wako Pure Chemical Industries, Ltd. [trade name]), 2,2'-azobis (2-methylbutyronitrile); V-59 (Wako Pure Chemical Industries, Ltd.) 〔Product ], 1,1′-azobis (cyclohexane-1-carbonitrile); V-40 (manufactured by Wako Pure Chemical Industries, Ltd. [trade name]), 2,2′-azobis [N- (2-propenyl)- 2-methylpropionamide]; VF-096 (manufactured by Wako Pure Chemical Industries, Ltd. [trade name]); [(Cyano-1-methylethyl) azo] formamide; V-30 (Wako Pure Chemical Industries, Ltd. [trade name]), 2,2′-azobis (N-butyl-2-methylpropionamide); VAm- 110 (Wako Pure Chemical Industries, Ltd. [trade name]), 2,2′-azo (N-cyclohexyl-2-methylpropionamide); VAm-111 (Wako Pure Chemical Industries, Ltd. [trade name]), etc. As a water-soluble azo polymerization initiator, 2,2′-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride; VA-044 (trade name, manufactured by Wako Pure Chemical Industries, Ltd.) ), 2,2′-azobis [2- (2-imidazolin-2-yl) propane] disulfate dihydrate; VA-046B (manufactured by Wako Pure Chemical Industries, Ltd. [trade name]), 2, 2'-azobis (2-methylpropionami Dihydrochloride; V-50 (manufactured by Wako Pure Chemical Industries, Ltd. [trade name]), 2,2′-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] tetrahydrate; VA-057 (manufactured by Wako Pure Chemical Industries, Ltd. [trade name]), 2,2′-azobis {2- [1- (2-hydroxyethyl) -2-imidazolin-2-yl] propane} dihydrochloride; VA-060 (manufactured by Wako Pure Chemical Industries, Ltd. [trade name]), 2,2′-azobis [2- (2-imidazolin-2-yl) propane]; VA-061 (manufactured by Wako Pure Chemical Industries, Ltd. [ Product name]), 2,2′-azobis (1-imino-1-pyrrolidino-2-ethylpropane) dihydrochloride; VA-067 (manufactured by Wako Pure Chemical Industries, Ltd. [product name]), 2,2′- Azobis {2-methyl-N- [1,1-bis (hydroxymethyl) ) -2-hydroxyethyl] propionamide}; VA-080 (manufactured by Wako Pure Chemical Industries, Ltd. [trade name]), 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) propionamide] VA-086 (manufactured by Wako Pure Chemical Industries, Ltd. [trade name]), 2,2′-azobis (2-amidinopropane) dihydrochloride, 2,2′-azobis (2-N-benzylamidinopropane) As a polymer azo polymerization initiator such as hydrochloride, 2,2′-azobis [2-N- (2-hydroxyethyl) amidinopropane] dihydrochloride, a polydimethylsiloxane unit-containing polymer azo polymerization initiator; VPS-0501 (polysiloxane unit molecular weight of about 5,000), VPS-1001 (polysiloxane unit molecular weight of about 10,000) (both Wako Pure Chemical Industries, Ltd.) (Trade name)), polyethylene glycol unit-containing polymer azo polymerization initiator; VPE-0201 (polyethylene glycol unit molecular weight of about 2,000), VPE-0401 (polyethylene glycol unit molecular weight of about 4,000), VPE-0601 ( Polyethylene glycol unit molecular weight of about 6,000) (both manufactured by Wako Pure Chemical Industries, Ltd. [trade name]). For example, on the homepage of Wako Pure Chemical Industries, Ltd. (www.wako-chem.co.jp), various water-soluble azo polymerization initiators, oil-soluble azo polymerization initiators, and polymer azo polymerization initiators are available for 10 hours. It is described and available with a half-life temperature and its structural formula. Although the addition amount of a polymerization initiator is not specifically limited, It is 0.1-30 mass% with respect to all the monomer components, More preferably, it is 1-20 mass%, Most preferably, it is 2-10 mass%.

  In the production method of the present invention, the polymerization initiator is preferably contained in an organic compound solution, and a polymer azo polymerization initiator is preferably used as the polymerization initiator. The polymer azo polymerization initiator is a unique polymerization initiator that easily gives a block polymer by copolymerization with a polymerizable compound. Its structure is a polymer segment (for example, polydimethylsiloxane unit, polyethylene glycol unit) and azo group repeatedly bonded, and there are several radical generation points in one molecule. In addition, it is possible to synthesize polymers with very high blocking efficiency. In the present invention, the polymer azo polymerization initiator has a polymerization initiating function, and in the copolymerization with the polymerizable compound, a block copolymer with the polymer segment is formed inside, on the surface of the fine particle structure, or both. It is preferable that By combining at least one polymerizable compound, the hydrophilicity / hydrophobicity of the surface of the formed fine particles can be easily controlled, so that an organic fine particle dispersion excellent in dispersion stability and organic fine particles can be provided. it can.

  In the method for producing an organic fine particle dispersion of the present invention, the dispersion may be copolymerized with a monomer that copolymerizes with a polymerizable compound. There is no particular limitation on the time when the copolymerization monomer is contained, but it is preferable that at least one copolymerization monomer is contained in at least one of the organic compound solution and the precipitation solvent that can be at least partially diffused into the solution. The copolymerization monomer is not particularly limited as long as it does not hinder the precipitation of fine particles and the stabilization of the dispersion, and examples thereof include the polymerizable compounds mentioned above.

  In the method for producing an organic fine particle dispersion of the present invention, various inorganic or organic functional additives may be allowed to coexist in the dispersion regardless of whether they are copolymerized. The timing of adding the functional additive is not particularly limited, but preferred examples include a case where it is added to at least one of the organic compound solution and the precipitation solvent which can be at least partially diffused into the solution. The functional additive is not particularly limited as long as it does not hinder the precipitation of fine particles and the stabilization of the dispersion. For example, a metal sequestering agent, a bactericidal agent, a fungicide, a fragrance, an ultraviolet absorber, an antioxidant, and a surface tension modifier. , Water-soluble resins, pH adjusters, urea and the like.

  In the method for producing an organic fine particle dispersion of the present invention, the organic compound is precipitated as fine particles and the polymerizable compound in the dispersion is polymerized as it is, so that extremely high dispersion stability can be realized in the fine particle dispersion. This effect is considered as follows. Since the polymerizable compound is present in the process of depositing the dissolved organic compound into fine particles, the polymerizable compound is adsorbed integrally with the precipitated fine particles, and the fine particles are efficiently surrounded by the polymerizable compound without gaps. For this reason, the adsorption state of the polymerizable compound, which cannot be obtained simply by mixing the organic fine particles and the polymerizable compound, can be obtained. By subjecting this to a polymerization reaction as it is, the polymerizable compound can be surely polymerized so as to densely wrap the entire surface of the organic fine particles, and preferably, it can be firmly and uniformly fixed and not detached. In particular, when the polymerizable compound is a polymerizable surfactant, the stabilizing effect is further enhanced because it is more strongly adsorbed on the surface of the fine particles and surrounds the fine particles. As described above, in the present invention, by using the polymerizable compound, both the size control function at the time of build-up and the subsequent encapsulation function can be exhibited. Thereby, the finely dispersed organic fine particles can be encapsulated as they are, and high dispersion stability and storage stability can be imparted to nano-sized organic fine particles having a uniform particle diameter.

In the method for producing an organic fine particle dispersion of the present invention, the timing and method for polymerizing the polymerizable compound are not particularly limited. For example, the following two processes are shown as examples. It may be performed during or after 1), during or after step (2), or both. At this time, it is preferable to carry out both (1) and (2), and the certainty of the polymerization carried out once is increased. When the polymerization is carried out once, preferably during or after step (1) or step (2), more preferably after step (1) or step (2), particularly preferably step (1). ) After.
(1) A process of mixing a solution in which an organic compound is dissolved and a precipitation solvent in which at least part of the organic compound can diffuse.
(2) A process of concentrating and purifying the dispersion after mixing.

Similarly, the addition timing and method of the polymerization initiator are not particularly limited. For example, the polymerization initiator may be carried out a plurality of times by any one or a combination of the following four aspects. At this time, it is preferable to add the polymerization initiator a plurality of times from the viewpoint of increasing the certainty of polymerization rather than combining several processes or starting once. When it is added once, it is preferably (1), (2), (3), more preferably (1) or (3), and particularly preferably (1).
(1) Add the organic compound to the dissolved solution.
(2) It is added to a precipitation solvent that can be at least partially diffused into the solution.
(3) A solution in which an organic compound is dissolved and a precipitation solvent in which at least a part of the organic compound can be diffused are mixed and then added.
(4) The dispersion after mixing is concentrated and purified and then added.

In the method for producing an organic fine particle dispersion of the present invention, as described above, the polymerizable compound is preferably contained in at least one of an organic compound solution and a precipitation solvent capable of diffusing at least partially in the solution. It is more preferable to make it contain. When other polymerizable compounds and dispersants are used in combination, the mode is not particularly limited. For example, they may be dissolved in either an organic compound solution or a precipitation solvent that can be at least partially diffused in the solution. You may add to the dispersion liquid after mixing. Further, when the fine particles are precipitated, if the effect of the present invention is not hindered, an organic compound solution or a liquid of a precipitation solvent capable of diffusing at least a part of the organic compound solution may be mixed with the solution as necessary. You may mix sequentially.
The polymerization reaction temperature can be selected according to the type of the polymerization initiator, and is preferably 40 ° C to 100 ° C, more preferably 50 ° C to 90 ° C, and particularly preferably 50 ° C to 80 ° C.
The polymerization reaction time can be 1 to 12 hours, although it depends on the polymerizable compound used, its concentration, and the reaction temperature of the polymerization initiator.

In order to increase the fastness of organic fine particles, etc., UV absorbers, antioxidants, fragrances, fungicides, surface tension modifiers, water-soluble resins, bactericides, pH adjusters, urea and other additives are used in combination. Also good. The timing and method of addition of these are not particularly limited. For example, the following four aspects may be used, and any of these may be performed in combination. When the predetermined compound is added, it is preferably (1), (2), (3), more preferably (1) or (3), and particularly preferably (1).
(1) Add the organic compound to the dissolved solution.
(2) It is added to a precipitation solvent that can be at least partially diffused into the solution.
(3) A solution in which an organic compound is dissolved and a precipitation solvent in which at least a part of the organic compound can be diffused are mixed and then added.
(4) The dispersion after mixing is concentrated and purified and then added.
In order to adjust the degree of polymerization (molecular weight), various chain transfer agents (for example, catechols, alcohols, thiols, mercaptans) may be used.
In order to further improve the uniform dispersibility and storage stability of the organic fine particles, the content of the polymerizable compound is preferably in the range of 0.1 to 1000 parts by mass with respect to 100 parts by mass of the organic compound. Preferably it is the range of 1-500 mass parts, Most preferably, it is the range of 10-250 mass parts. If the amount is less than 0.1 parts by mass, the dispersion stability of the organic fine particles may not be improved. As for the content when the dispersant is contained in addition to the polymerizable compound, the total amount of both is preferably within the above range.

Next, the organic fine particles produced by the production method of the present invention will be described.
There is a method for expressing the average size of the population by quantifying in the particle measurement method, but the most commonly used is the mode diameter indicating the maximum value of the distribution and the median diameter corresponding to the median value of the integral distribution curve. , And various average diameters (length average, area average, weight average, number average, volume average, etc.). The particle size of the organic fine particles produced by the production method of the present invention is arbitrary as long as the flow path is not blocked, but the mode diameter is preferably 1 μm or less. Preferably it is 3 nm-800 nm, Most preferably, it is 5 nm-500 nm.

  Uniform particle size means that the particle size of the fine particles is uniform, that is, not only the size of the contained particles is uniform, but also the chemical composition and crystal structure within the particle do not vary between particles. However, it is an important factor that determines the performance of the particles. In particular, in the case of ultrafine particles having a particle size of nanometer, importance is attached as a factor governing the characteristics of the particles. The method for producing an organic fine particle dispersion of the present invention can not only make fine particles having a small particle diameter, but also control the size and make the sizes uniform. Although the arithmetic standard deviation value is used as an index indicating that the sizes are uniform, the arithmetic standard deviation value of the organic fine particles produced by the method for producing an organic fine particle dispersion of the present invention is preferably 130 nm or less, particularly Preferably, it is 80 nm or less, and the peak of the particle size distribution can be sharpened. The arithmetic standard deviation value is a method of obtaining the standard deviation by regarding the particle size distribution as a normal distribution, and is a value obtained by dividing the value obtained by subtracting the 16% particle size from the 84% particle size of the integrated distribution by 2.

  Further, a value (Mv / Mn) obtained by dividing the volume average particle diameter Mv by the number average particle diameter Mn may be expressed as an index of monodispersity. In the present invention, unless otherwise specified, the monodispersity of the fine particles is described above. The value is represented by the value of Mv / Mn, and the smaller the value is, the better the monodispersity is. The organic fine particles of the present invention preferably have a value of 1.80 or less, and preferably 1.60 or less. More preferably, it is particularly preferably 1.40 or less. The volume average particle diameter Mv and the number average particle diameter Mn can be measured by, for example, a dynamic light scattering method.

  Furthermore, it is preferable that the organic fine particles of the present invention have high stability, and can be represented by the rate of change of the particle size due to the heat storage treatment as an index indicating the stability, and the rate of change of the volume average particle size Mv described above. (Change rate of volume average particle diameter Mv: Volume average particle diameter Mv after heat storage treatment is divided by volume average particle diameter Mv before heat storage treatment and 1 is subtracted, and the absolute value is expressed as a percentage. ) The organic fine particles of the present invention preferably have a change rate of the volume average particle diameter Mv of 6.0% or less when subjected to heat storage treatment at 60 to 80 ° C. for 50 to 300 hours, and is 5.0% or less. More preferably, it is more preferably 4.0% or less.

  In the production method of the present invention, in addition to the organic compound solution and the precipitation solvent described above, an arbitrary fluid may be mixed together to precipitate organic fine particles. The fluid to be mixed may be a fluid that is mixed with both liquids, or may be a fluid that is not mixed. Mixing fluids include solutions using the same or relatively similar organic solvents, or solutions using highly polar organic solvents such as methanol, and water. Examples thereof include a solution using a polar solvent and a solution using a highly polar solvent such as methanol. When a gas such as air, nitrogen, oxygen, argon, helium is used as the fluid, they may be dissolved in a liquid or introduced as a gas into a flow path as it is, or preferably introduced as a gas. .

  According to the method for producing an organic fine particle dispersion of the present invention, an organic compound is precipitated as fine particles, and a polymerization reaction of the polymerizable compound is performed as it is, and a polymerizable film is preferably formed and fixed on the fine particles. That is, there is no need to pulverize the fine particles or to separate the produced fine particles and switch the process equipment. This is nothing but the introduction of the continuous production method by flow, and has the merit of greatly reducing physical loss such as quality stabilization, process stabilization, time and energy, and further transfer.

The organic fine particle dispersion of the present invention can be purified, concentrated and classified by filtration or centrifugation before and / or after the polymerization treatment. Furthermore, depending on the purpose of use, solvents (wetting agents, etc.), additives (metal sequestering agents, bactericides, fungicides, fragrances, ultraviolet absorbers, antioxidants, surface tension regulators, water-soluble resins, pH regulators) , Urea, etc.) may be added to adjust the liquid properties.
The organic fine particle dispersion of the present invention can be used as, for example, a suitable inkjet ink. In particular, since the presence of acid or alkali is not essential for the dissolution of organic compounds, a neutral dispersion is manufactured, and the surface tension, viscosity, antiseptic properties, etc. are adjusted as they are, and a good inkjet ink is efficiently prepared. can do. Viscosity preferred when prepared as an ink-jet ink varies depending on the organic compound species and concentration, but generally, for example, when it is 5% by mass, it is preferably 20 mPa · s or less, and preferably 10 mPa · s or less. More preferably, it is particularly preferably 5 mPa · s or less. In addition, as described above, the organic fine particle dispersion obtained by the production method of the present invention whose pH is not limited is appropriately used for a good color filter or the like by appropriately performing separation, concentration, preparation of liquid properties, etc. it can.
Thus, it is an advantage of the present invention that the presence of an acid or alkali is not essential, and the product can be produced without any influence.

  In the method for producing an organic fine particle dispersion of the present invention, a flow reaction using a flow path is performed under conditions of 1 mm or less or a laminar flow, the reaction time is controlled, and the reaction temperature control in a narrow space is precise. By using this, it is possible to produce organic fine particles with smaller and uniform particle size compared to the conventional reprecipitation method. Can be suitably manufactured for mass production. Furthermore, since the stability of the organic fine particles is increased by the polymerization treatment of the polymerizable compound, the applicability of the organic fine particle dispersion is high.

  The present invention will be described below in more detail based on examples, but the present invention is not limited to these examples.

  The particle size distribution shown in the examples was measured with a Microtrac UPA150 manufactured by Nikkiso Co., Ltd.

(Example 1)
1.0 g of Exemplified Compound (I-1) and 0.5 g of vinylpyrrolidone were dissolved in 50 mL of tetrahydrofuran (THF) together with 1.5 g of Aqualon KH-10 (trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) at room temperature ( IA solution). Distilled water was used as the IIA solution. Impurities such as dust were removed by passing these through a 0.45 μm microfilter (manufactured by Sartorius). Next, the reaction was carried out by the following procedure using a simple reactor having the flow path configuration of the reactor of FIG. That is, two Teflon (registered trademark) tubes having a length of 50 cm and an equivalent diameter of 1 mm are connected to two inlets of a Teflon (registered trademark) Y-shaped connector (manufactured by Tokyo Rika Kikai Co., Ltd.) having an equivalent diameter of 500 μm. Connected to each other, and syringes containing IA solution and IIA solution were connected to each other and set in a pump. A Teflon (registered trademark) tube having a length of 1.5 m and an equivalent diameter of 500 μm was connected to the outlet of the connector. The IA solution was sent out at 1.6 mL / min and the IIA solution was sent out at a delivery rate of 10 mL / min (Reynolds number of about 500). Since a dispersion of I-1 was obtained from the tip of the tube outlet, it was collected and used as Sample 1 for comparison. The volume average particle diameter Mv of the fine particles in Sample 1 was 35.1 nm, and the ratio of volume average particle diameter Mv / number average particle diameter Mn, which is an index of monodispersibility, was 1.40.
Next, the dispersion liquid of Sample 1 was purified while adding distilled water so as to maintain the liquid volume with an ultrafiltration device (manufactured by Advantech Toyo Co., Ltd., UHP-25K [trade name], molecular weight cut off 50,000).
Further, 5% potassium persulfate (K ₂ S ₂ O ₈ ) of Aqualon KH-10 contained in Sample 1 was added and heated at 70 ° C. for 3 hours to obtain Sample 1a of the present invention. The volume average particle diameter Mv of the fine particles in the sample 1a was 32.0 nm, and the ratio of volume average particle diameter Mv / number average particle diameter Mn, which is an index of monodispersibility, was 1.41.
Sample 1 and sample 1a were each heated and stored at 70 ° C. for 100 hours. The change rate of the volume average particle diameter of the fine particles in Sample 1 was 6.5%, and the change ratio of the volume average particle diameter of the fine particles in Sample 1a was 2.6%. From this result, it is understood that the stability is improved by the polymerization treatment.

(Example 2)
Replace AQUALON KH10 in the IA solution used in Example 1 with an equal mass of styrene (made by Wako Pure Chemical Industries, Ltd., special grade) (IA 'solution), and replace with the IIA solution to prepare a 1% aqueous solution of sodium lauryl sulfate. (IIA 'solution). In the same manner as in Example 1, the IA ′ liquid and the IIA ′ liquid were mixed to prepare a dispersion, and a sample 2 for comparison was obtained. The volume average particle diameter Mv of the fine particles in Sample 2 was 44.7 nm, and the ratio of volume average particle diameter Mv / number average particle diameter Mn, which is an index of monodispersibility, was 1.91.
Next, the dispersion liquid of Sample 2 was purified while adding distilled water so as to maintain the liquid volume with an ultrafiltration device (manufactured by Advantech Toyo Co., Ltd., UHP-25K [trade name], molecular weight cut off 50,000). Furthermore, 1% amount of K ₂ S ₂ O ₈ of styrene contained in the dispersion liquid of Sample 2 was added and heated at 70 ° C. for 3 hours to obtain Sample 2a of the present invention. The volume average particle diameter Mv of the fine particles in the sample 2a was 39.8 nm, and the ratio of volume average particle diameter Mv / number average particle diameter Mn, which is an index of monodispersibility, was 1.80.
Sample 2 and Sample 2a were each heated at 70 ° C. for 100 hours. The rate of change of the volume average particle size of the fine particles in Sample 2 was 5.4%, and the rate of change of the volume average particle size of the fine particles in Sample 2a was 4.1%. From this result, it is understood that the stability is improved by the polymerization treatment.

(Comparative Example 1)
A stirring bar was placed in a 50 mL beaker, and 25.0 mL of the IIA solution was stirred at room temperature. To this, 4.0 mL of IA solution was poured using a syringe to obtain a dispersion of Compound I-1 (Sample 3 for comparison). The volume average particle diameter Mv of the fine particles in Sample 3 was 88.4 nm, and the ratio of volume average particle diameter Mv / number average particle diameter Mn, which is an index of monodispersibility, was 2.91. Compared to Example 1, the size was clearly increased and the particle size distribution was broadened.
Next, in the same manner as in Example 1, a sample 3a of the present invention subjected to polymerization treatment was obtained. The volume average particle diameter Mv of the fine particles in the sample 3a was 94.3 nm, and the ratio of volume average particle diameter Mv / number average particle diameter Mn, which is an index of monodispersibility, was 3.31.
Sample 3 and sample 3a were each heated and stored at 70 ° C. for 100 hours. The change rate of the volume average particle diameter of the fine particles in Sample 3 was 15.5%, and the change ratio of the volume average particle diameter of the fine particles in Sample 3a was 11.1%. From this result, it can be seen that the comparative example is inferior in stability even by the polymerization treatment.

(Example 3)
A dispersion was prepared in the same manner as in Example 1 except that 10% of the total mass of Aqualon KH-10 was changed to the polymerizable compounds shown in Table 1, and Samples 4, 5, 6, 7, It was set to 8. These were each polymerized in the same manner as in Example 1 to obtain Samples 4a, 5a, 6a, 7a and 8a of the present invention. Table 1 shows the volume average particle diameter Mv and volume average particle diameter Mv / number average particle diameter Mn of the fine particles in each sample. Further, each sample was subjected to heat storage treatment in the same manner as in Example 1, and the rate of change in the volume average particle diameter Mv was measured and listed in Table 1. In Table 1, DVB represents divinylbenzene.

表１に示された結果より、いずれの有機微粒子分散液においても、本発明の製造方法により重合処理したものは、分散安定性及び保存安定性が向上していることが分かる。

From the results shown in Table 1, it can be seen that any of the organic fine particle dispersions is polymerized by the production method of the present invention and has improved dispersion stability and storage stability.

Example 4
Illustrative compound III-2 (3.0 g) 45.5 mL of dimethyl sulfoxide (DMSO), 2.4 g of styrene, 0.3 g of divinylbenzene, 0.15 g of polyvinylpyrrolidone K30 (trade name, manufactured by Tokyo Chemical Industry Co., Ltd.) VPE-0201 (trade name, manufactured by Wako Pure Chemical Industries, Ltd.) 1.5 g was dissolved at room temperature (IB solution). Distilled water was used as the IIB solution. Impurities such as dust were removed by passing these through a 0.45 μm microfilter (manufactured by Sartorius). As the microreactor device, a three-dimensional microreactor device having the following number of divisions (number of flow paths) and the like as shown in FIG. 8 was used.
(I) Number of supply flow paths (n): Divided into 5 for each of the two types of reaction solutions (a total of 10 flow paths merge. In addition, the apparatus of FIG. It is a device to do.)
(Ii) width (W) of supply flow paths 91 and 92: 400 μm each
(Iii) Depth (H) of supply flow paths 91 and 92: 400 μm each
(Iv) Diameter (D) of merging region 90 ... 800 μm
(V) Microchannel 93 diameter (R): 800 μm
(Vi) In the merging region 90, the crossing angle between the central axes of the supply flow channels 91 and 92 and the micro flow channel 93 is 90 °.
(Vii) Material of the device: stainless steel (SUS304)
(Viii) Flow path machining method: Performed by micro electric discharge machining, and the sealing method of the three parts of the supply block 81, the merging block 82, and the reaction block 83 was performed by metal surface sealing by mirror polishing. Two Teflon (registered trademark) tubes having a length of 50 cm and an equivalent diameter of 1 mm were connected to the two inlets using a connector, and syringes containing IB liquid and IIB liquid were respectively connected to the two ends and set in a pump. A Teflon (registered trademark) tube having a length of 1.5 m and an equivalent diameter of 2 mm was connected to the outlet of the connector. The IB solution was delivered at a delivery rate of 15 mL / min and the IIB solution at a delivery rate of 60 mL / min. At this time, the liquid flow was a laminar flow. Since a dispersion of III-2 was obtained from the tip of the tube outlet, it was collected and used as a sample 9 for comparison. The volume average particle diameter Mv of the fine particles in Sample 9 was 24.2 nm, and the ratio of volume average particle diameter Mv / number average particle diameter Mn, which is an index of monodispersibility, was 1.39.
Furthermore, it heated at 80 degreeC for 5 hours, and obtained the sample 9a of this invention. The volume average particle diameter Mv of the fine particles in the sample 9a was 22.9 nm, and the ratio of volume average particle diameter Mv / number average particle diameter Mn, which is an index of monodispersibility, was 1.38.

  Next, each of sample 9 and sample 9a was purified by adding ultrafiltration device (Advantech Toyo Co., Ltd., UHP-62K [trade name], molecular weight cut-off: 100,000) while adding distilled water to maintain the liquid volume, Then, heat storage treatment was performed at 60 ° C. for 100 hours. The change rate of the volume average particle diameter of the fine particles in the sample 9 was 4.1%, and the change ratio of the volume average particle diameter of the fine particles in the sample 9a was 2.0%. From this result, it is understood that the stability is improved by the polymerization treatment.

(Example 5)
In Example 1, five reactors were arranged in parallel, and a manifold capable of diverting to five was attached to the tip of two syringes for feeding. When the flow rate of one reactor was made equal and the dispersion liquid of I-1 was collected, the volume average particle diameter Mv was 35.5 nm, and the volume average particle diameter Mv / number average particle diameter, which is an index of monodispersity, was obtained. The ratio of Mn was 1.42. As described above, it was confirmed that there was almost no change in the fine particle characteristics due to the numbering up, and that the production amount could be increased by five times while maintaining good fine particle characteristics.

(Comparative Example 2)
The scale of Comparative Example 1 was scaled up 5 times. That is, a stirrer was placed in a 500 mL beaker, and 125.0 mL of the IIA solution was stirred at room temperature. 20.0 mL of IA liquid was dripped over about 1 hour using the syringe to this. The obtained dispersion had a volume average particle size Mv of 124.4 nm, and the ratio of volume average particle size Mv / number average particle size Mn, which is an index of monodispersibility, was 4.77. As described above, in the method of the comparative example, the variation in the fine particle characteristics increased due to the scale-up.

(Example 6)
In Example 1, an organic fine particle dispersion (sample 10) was used under the same conditions except that the Y-shaped connector having an equivalent diameter of 1 mm was used and the IA liquid and the IIA liquid were fed at a liquid feed speed such that the Reynolds number was about 4000. Got. The volume average particle diameter Mv of the fine particles in the sample 10 was 42.1 nm, and the ratio of volume average particle diameter Mv / number average particle diameter Mn, which is an index of monodispersibility, was 1.45.
Next, the dispersion liquid of Sample 10 was purified by adding distilled water so as to maintain the liquid volume with an ultrafiltration device (manufactured by Advantech Toyo Co., Ltd., UHP-25K (trade name), molecular weight cut off 50,000).
Furthermore, 5% amount of potassium persulfate (K ₂ S ₂ O ₈ ) of Aqualon KH-10 contained in this sample 10 was added and heated at 70 ° C. for 3 hours, and the organic fine particle dispersion of the present invention (sample 10a) Got. The volume average particle diameter Mv of the fine particles in the sample 10a was 44.0 nm, and the ratio of volume average particle diameter Mv / number average particle diameter Mn, which is an index of monodispersibility, was 1.44.
Sample 10 and sample 10a were each heated and stored at 70 ° C. for 100 hours. The change rate of the volume average particle size of the fine particles in the sample 10 was 7.9%, and the change rate of the volume average particle size of the fine particles in the sample 10a was 3.9%. From this result, it is understood that the stability is improved by the polymerization treatment.

(Example 7)
4-Vinylbenzoic acid (3.0 g) with dimethyl sulfoxide 45.5 mL, styrene 2.4 g, divinylbenzene 0.3 g, VPE-0201 (trade name, manufactured by Wako Pure Chemical Industries, Ltd.) 1.5 g at room temperature Dissolved (IC solution). Distilled water was used as the IIC solution. Impurities such as dust were removed by passing these through a 0.45 μm microfilter (manufactured by Sartorius). The same microreactor device as in Example 4 was used. Two Teflon (registered trademark) tubes having a length of 50 cm and an equivalent diameter of 1 mm were connected to the two inlets using a connector, and syringes containing IC solution and IIC solution were connected to the ends of the tubes and set in a pump. A Teflon (registered trademark) tube having a length of 1.5 m and an equivalent diameter of 2 mm was connected to the outlet of the connector. Sample 11 was obtained by feeding the IC solution at 15 mL / min and the IIC solution at a delivery rate of 90 mL / min. At this time, the liquid flow was a laminar flow. The obtained polymer fine particles had a volume average particle diameter Mv of 44.4 nm, and the ratio of volume average particle diameter Mv / number average particle diameter Mn, which is an index of monodispersibility, was 1.55. The dispersion obtained from the tip of the tube outlet was heated at 80 ° C. for 3 hours to obtain a sample 11a of the present invention. The volume average particle diameter Mv of the fine particles in the sample 11a was 55.5 nm, and the ratio of volume average particle diameter Mv / number average particle diameter Mn, which is an index of monodispersibility, was 1.49.
Sample 11 and sample 11a were each heated and stored at 70 ° C. for 100 hours. The change rate of the volume average particle size of the fine particles in the sample 11 was 6.5%, and the change rate of the volume average particle size of the fine particles in the sample 11a was 2.9%. From this result, it is understood that the stability is improved by the polymerization treatment.

(Examples 8 to 19)
Samples of the organic fine particle dispersion were prepared in the same manner except that the polymer compound, polymerization initiator, and reaction apparatus used in Example 7 were changed as shown in Table 2. Table 2 shows the results of measuring the average particle diameter (Mv), monodispersibility (Mv / Mn), and heat storage processability (%) in the same manner as in Example 7. In addition, all the high molecular compounds here were added to the liquid which melt | dissolved the organic compound.

表２中、スチレン−アクリル酸共重合体は、両親媒性の共重合ブロックポリマーであった。

In Table 2, the styrene-acrylic acid copolymer was an amphiphilic copolymer block polymer.

  From the results shown in Table 2, the dispersion of organic fine particles to which the polymer obtained by the production method of the present invention is immobilized has a dispersion stability regardless of containing extremely fine particles of nanometer size. It can be seen that the composition is excellent in stability and storage stability. In particular, it can be seen that a product obtained by bringing a plurality of divided liquid streams into contact at a single point has a smaller particle size and is monodispersed and has improved heat storage stability (Example for Example 8). 7, see Example 15 for Example 16). It can also be seen that the organic fine particles can be made finer and have a uniform particle size by using a specific polymer compound (see Examples 11 to 16). Then, by adding a polymer azo polymerization initiator to the organic compound solution, the particle size of the fine particles obtained by polymerizing and fixing the polymerizable compound is kept small, and it is monodispersed and enhances heat storage stability. (See Example 7 for Examples 17 and 18 and Example 8 for Example 19).

(Examples 20 to 24)
Samples of the organic fine particle dispersion were prepared in the same manner as in Example 1, except that the polymerization initiator and the reaction apparatus were changed as shown in Table 3 below. Table 3 shows the results obtained by measuring the average particle size (Mv), monodispersibility (Mv / Mn), and heat storage processability (%) of each sample in the same manner as in Example 7.

表３に示した結果より、本発明の製造方法により得た重合体が固定化された有機微粒子の分散液はいずれも分散安定性及び保存安定性に優れることが分かる。実施例２０〜２３においては、いずれも実施例１の重合開始剤の種類を替えたものであるが、加熱処理後における安定性はいずれも同等な性能を示した。更に実施例２３と２４を比較してわかるように、複数に分割された液流を一点で合流接触させる反応装置を用いたほうが、加熱処理前後のいずれにおいても安定性に優れた分散液を得る事ができた。

From the results shown in Table 3, it can be seen that all dispersions of organic fine particles to which the polymer obtained by the production method of the present invention is immobilized are excellent in dispersion stability and storage stability. In Examples 20-23, all changed the kind of the polymerization initiator of Example 1, but the stability after heat processing showed the same performance. Further, as can be seen from a comparison between Examples 23 and 24, it is possible to obtain a dispersion having excellent stability both before and after the heat treatment by using a reaction apparatus in which a plurality of divided liquid flows are brought into contact at one point. I was able to do things.

(Example 25)
2,9-dimethylquinacridone (Pigment Red 122, manufactured by Clariant, HOSTAPERM PINK E (trade name)) 0.5 g dimethyl sulfoxide 5.0 mL, 28% sodium methoxide methanol solution (manufactured by Wako Pure Chemical Industries, Ltd.) ) 0.85 mL, 25% Aqualon KH-10 (trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) in DMSO solution (2.0 mL) was dissolved at room temperature. Further, styrene (0.05 g) was added as a polymerizable compound, and 0.25 g of a styrene-acrylic acid copolymer (acid value 250, molecular weight 5000) was added as a polymer compound. (ID solution). The pH of the ID solution exceeded the measurement limit (pH 14) and could not be measured. Distilled water was used as the IID liquid. Impurities such as dust were removed by passing these through a 0.45 μm microfilter (manufactured by Sartorius). The same reaction apparatus as in Example 1 was used and the same operation was performed. Since a dispersion of 2,9-dimethylquinacridone was obtained from the tip of the tube outlet, it was collected and used as a sample 29 for comparison. Sample 29 had a volume average particle diameter Mv of 20.0 nm, and the ratio of volume average particle diameter Mv / number average particle diameter Mn, which is an index of monodispersibility, was 1.55.
Next, this pigment dispersion was purified by adding distilled water so as to maintain the liquid amount with an ultrafiltration device (manufactured by Advantech Toyo Co., Ltd., UHP-25K (trade name), molecular weight cut off 200,000). Further, 5% potassium persulfate (K ₂ S ₂ O ₈ ) of Aqualon KH-10 contained in this pigment dispersion was added and heated at 70 ° C. for 5 hours to obtain Sample 29a of the present invention. The volume average particle diameter Mv of the sample 29a was 19.5 nm, and the ratio of volume average particle diameter Mv / number average particle diameter Mn, which is an index of monodispersibility, was 1.57.
Sample 29 and sample 29a were each heated and stored at 70 ° C. for 100 hours. The change rate of the volume average particle size of the sample 29 is 4.1% (change rate of the volume average particle size: the volume average particle size Mv after the heat storage treatment is divided by the volume average particle size Mv before the heat storage treatment, and 1 is obtained. Subtracted value), the change rate of the volume average particle diameter of the sample 29a was 2.9%. From this result, it is understood that the stability is improved by the polymerization treatment.

(Examples 26 to 31)
A sample of the organic fine particle dispersion was prepared in the same manner except that the organic pigment, polymerizable compound, polymer compound, polymerization initiator, and reaction apparatus used in Example 25 were changed as shown in Table 4 below. Prepared. When the polymerizable compound was a polymer azo polymerization initiator, 50% by mass of the organic pigment was added to the solution in which the organic pigment was dissolved. Table 4 shows the results of measuring the average particle size (Mv), monodispersibility (Mv / Mn), and heat storage processability (%) of each sample in the same manner as in Example 25. In addition, all the high molecular compounds here were added to the liquid which melt | dissolved the organic pigment.

  From the results shown in Table 4, the dispersion of the organic pigment fine particles to which the polymer obtained by the production method of the present invention was immobilized was dispersed in spite of containing extremely fine particles of nanometer size. It turns out that it is excellent in stability and storage stability. In particular, it can be seen that when a polymerizable compound is polymerized by using an amphiphilic copolymer block polymer and a polymer azo polymerization initiator in combination as the polymer compound, the stability after the heat treatment is most increased (Example 27). And see Examples 25 and 26). In particular, it is understood that the liquid flow obtained by dividing the liquid flow divided into a plurality of points at one point is further reduced in particle size and monodispersed, and the heat storage stability is improved (see Examples 28 and 27). Comparison).

It is a top view which shows typically the reaction apparatus which has a Y-shaped flow path on one side. It is sectional drawing of the II line | wire of FIGS. 1-1. It is a longitudinal cross-sectional view which shows typically the reaction apparatus which has a cylindrical tube type flow path provided with the flow path penetrated in the one side. It is a cross-sectional view of the IIa-IIa line of FIG. FIG. 2 is a transverse sectional view taken along line IIb-IIb in FIG. 2-1. It is a top view which shows typically the reaction apparatus which has a Y-shaped channel on both sides. It is sectional drawing of the III-III line of FIGS. It is sectional drawing which shows typically the reaction apparatus which has a cylindrical tube type flow path provided with the flow path penetrated on both sides. It is a plane sectional view showing typically one embodiment of a plane type micro reactor device. It is a plane sectional view showing typically another embodiment of a plane type micro reactor device. It is a plane sectional view showing typically another embodiment of a plane type micro reactor device. 1 is an exploded perspective view schematically showing one embodiment of a three-dimensional microreactor device. FIG.

Explanation of symbols

10, 20, 30, 40 Reactor body 11, 12, 21, 22, 31, 32, 41, 42 Inlet 13, 33 Channel 13a, 13b, 23a, 23b, 33a, 33b, 43a, 43b Inlet channel 13c, 23c, 33c, 43c Reaction flow path 13d, 23d, 33d, 43d Fluid confluence 33e, 43e Fluid diversion point 33f, 33g, 43f, 43g Discharge flow path 14, 24, 34, 35, 44, 45 Discharge port 50 , 60, 70, 80 Microreactor devices 51, 52, 61, 62, 71, 72 Solution supply channels 51A, 61A, 71A Split supply channels 53, 63, 73 Microchannels 54, 64, 74 Merge region 81 Supply block 82 Merge block 83 Reaction block 86 Outer annular groove 85 Inner annular grooves 87, 88 Through holes 90 in the supply block Flow area)
91 Long radial groove 92 Short radial groove 95, 96 Through-hole 93 of confluence block Through-hole of reaction block (micro flow path)

Claims (19)

  A solution in which an organic compound is dissolved in a solvent and a precipitation solvent that is different from the solvent and that can diffuse at least partially in the solvent are circulated through a channel having an equivalent diameter of 1 mm or less to contact the two. The organic compound is precipitated as fine particles in the presence of the polymerizable compound in the distribution process, and then the polymerizable compound is polymerized, and the polymer of the polymerizable compound is fixed to the fine particles. A method for producing an organic fine particle dispersion.   The method for producing an organic fine particle dispersion according to claim 1, wherein a polymerizable compound is contained in at least one of the organic compound solution and the precipitation solvent.   A solution in which an organic compound is dissolved in a solvent and a precipitation solvent that is different from the solvent and that can diffuse at least partially in the solvent are circulated as a laminar flow in the flow path, and both are brought into contact with each other. In the process, the organic compound is precipitated as fine particles in the presence of a polymerizable compound, then the polymerizable compound is polymerized, and the polymer of the polymerizable compound is immobilized on the fine particles. Liquid manufacturing method.   4. The method for producing an organic fine particle dispersion according to claim 3, wherein a polymerizable compound is contained in at least one of the organic compound solution and the precipitation solvent.   The method for producing an organic fine particle dispersion according to claim 1, wherein the precipitation solvent is a poor solvent for the organic compound.   6. The method for producing an organic fine particle dispersion according to claim 1, wherein the flow contact in the flow path is performed in a micro reaction field.   The method for producing an organic fine particle dispersion according to claim 6, wherein the flow contact in the flow path is performed by a microreactor.   When the liquid stream of the solution in which the organic compound is dissolved in the solvent and the liquid stream of the precipitation solvent are combined and mixed, at least one liquid stream is divided into a plurality of divided liquid streams, The central axis of at least one of the plurality of divided liquid streams and the central axis of the other liquid stream are merged so as to intersect at one point in the merge area, and mixed. The manufacturing method of the organic fine particle dispersion liquid of any one of 1-7.   9. The method for producing organic fine particles according to claim 8, wherein the plurality of divided liquid flows circulate in a flow path extending radially from the central confluence region toward the central confluence region and are mixed and mixed. .   The method for producing an organic fine particle dispersion according to any one of claims 1 to 9, wherein the polymerizable compound is a polymerizable surfactant.   The method for producing an organic fine particle dispersion according to any one of claims 1 to 10, wherein at least one of the organic compound solution and the precipitation solvent contains at least one dispersant.   The method for producing an organic fine particle dispersion according to claim 11, wherein at least one of the dispersants is a polymer dispersant.   The method for producing an organic fine particle dispersion according to claim 12, wherein at least one of the polymer dispersants is a block copolymer compound.   14. The method for producing an organic fine particle dispersion according to claim 13, wherein the block copolymer compound is an amphiphilic polymer.   The organic fine particle dispersion according to any one of claims 1 to 14, wherein at least one of the organic compound solution and the precipitation solvent contains at least one monomer copolymerizable with the polymerizable compound. Manufacturing method.   The method for producing an organic fine particle dispersion according to claim 1, wherein a solution obtained by dissolving the organic compound in a solvent contains a polymerization initiator.   The method for producing an organic fine particle dispersion according to claim 16, wherein the polymerization initiator is a polymer azo polymerization initiator.   The organic fine particle manufactured by the method of any one of Claims 1-17.   The organic fine particles according to claim 18, wherein the mode diameter is 1 μm or less.

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