JP2010077365A - Manufacturing method of fine particle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a fine particle that permits exhibition of sufficient functions with a small used amount of a functional chemical to reduce the cost of the chemical and can be realized by a single microdevice. <P>SOLUTION: A pigment solution L1 comprising an organic pigment dissolved in a solvent, a poor solvent L2 which lowers solubility of the organic pigment in the pigment solution L1 thereby to deposit particles of the organic pigment, a dispersant solution L3 containing a dispersant which exhibits functions on the surface part of the deposited particles and a buffer solution L4 which acts on the organic pigment as a good solvent for the organic pigment and is at least almost compatible with the poor solvent are made to join together at one joining region 14 through independent inlet flow paths 16A-16E, respectively, and made to flow out through one mixed flow path 18 from the joint region 14, and, in the joint region 14, the four flows are made to join so that a phase of the buffer solution L4 is formed between a phase comprising the pigment solution L1 and the poor solvent L2 and a phase of a dispersant solution L3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing fine particles, and more particularly to a build-up process for producing fine organic pigment particles by mixing a solution obtained by dissolving an organic pigment in a good solvent with a poor solvent having low solubility in the organic pigment.

  Since pigments have a clear color tone and high coloring power, they are used as optical materials in a wide range of applications such as paints, printing inks, electrophotographic toners, inkjet inks, and color filters.

  In addition, since nano-sized particles are sufficiently smaller than visible light, a material transparent to visible light can be obtained if the particles can be solidified (hybridized) while maintaining dispersibility. By applying this, nanoparticles having various optical properties are dispersed in the resin without agglomeration, whereby an optical material having excellent properties possessed by the nanoparticles can be obtained.

  For example, in the case of a color filter using pigment particles as an optical material, high contrast (CR) can be realized by giving high wavelength selectivity. However, when pigment particles of several hundred nanometers are mixed in the dispersion, the contrast is reduced. It is known that it will decline and impair the value as a product. In order to raise CR, it is necessary to have high monodispersity without the presence of coarse particles, as a matter of course, being fine particles.

  Incidentally, it is now possible to produce monodisperse nanoparticle pigment fine particles by a precipitation type fine particle production method, so-called build-up method. In this method, an organic pigment is once dissolved at a molecular level with an appropriate good solvent, and a poor solvent is added later to lower the solubility to promote precipitation. For example, JP-A-2004-43776 discloses a method for producing pigment fine particles using a build-up method.

In this production method, pigment particles are precipitated by bringing a pigment solution containing an organic pigment and a dispersant into contact with water which is a poor solvent.
JP 2004-43776 A

  However, the method for producing fine particles of Patent Document 1 has a problem that the dispersion performance is not commensurate with the amount of use (content) of the dispersant contained in the pigment solution. As a result, it is necessary to use an excessive amount of the dispersing agent in order to sufficiently exhibit the dispersion performance, which increases the cost of the medicine. Not only the dispersant but also functional agents such as pigment derivatives and particle growth inhibitors used in the production of fine particles have the same problem.

  The present invention has been made in view of such circumstances, and can exhibit a sufficient function with a small amount of use of a functional drug, so that the cost of the drug can be reduced. An object of the present invention is to provide a method for producing fine particles, which can be realized with a micro device and can reduce the cost of the apparatus.

  According to a first aspect of the present invention, in order to achieve the above object, a material solution obtained by dissolving a particle forming material in a solvent, and the solubility of the particle forming material in the material solution is lowered to reduce the solubility of the particle forming material. A poor solvent for precipitating particles, a functional solution containing a functional agent that exhibits a function on the surface portion of the particles to be deposited, and acting as a good solvent for the fine particle forming material and in the poor solvent On the other hand, a buffer solution that is approximately compatible or more compatible is merged in one merging region through independent inlet channels, and flows out from the merging region through one mixing channel. In the merging region, And providing a fine particle production method, wherein the buffer solution phase is formed between the phase composed of the material solution and the poor solvent and the phase of the functional solution so that the phase of the buffer solution is formed.

  In the present invention, the functional drug is preferably at least one of a dispersant, a pigment derivative, and a particle growth inhibitor. Further, the term “above substantially compatible” means that there is a compatibility of 50% by mass or more, more preferably 80% by mass or more, and still more preferably 95% by mass or more.

  The dispersant, which is one of the functional drugs used in the production of fine particles, is an important drug for producing fine particles with good monodispersibility, but the dispersant is a main chain and side chain with flexibility. And exerts its function by charge repulsion or steric repulsion. For this reason, a dispersing agent cannot exhibit the function, unless the functional part which exhibits a dispersing function is exposed to the particle | grain surface of particle | grains.

  As a result of diligent research on the conventional problems in which the dispersant does not exhibit the dispersion performance commensurate with the amount of use, the pigment solution (material solution) contains the dispersant (functional agent) in advance as in the past. In this case, the dispersant is present from the initial stage of particle formation when particle nuclei are generated by precipitation, and the functional part of the dispersant used (containing) is taken into the particles during the growth of the particle nuclei. I got the knowledge that. It can be confirmed by the spin diffusion phenomenon by NMR (nuclear magnetic resonance apparatus) that the functional part of the dispersant is taken into the particles.

  In addition, as a functional chemical | medical agent which cannot fully exhibit a function by being taken in inside a particle | grain, all the chemical | medical agents which exhibit a function on the particle | grain surface in manufacture of microparticles | fine-particles, such as a pigment derivative and a particle growth inhibitor, are included.

  According to claim 1 of the present invention, a functional agent that exhibits a function on the surface of the particles to be formed (for example, a dispersant) is prepared separately as a functional solution without being included in the material solution. The solvent and the functional solution were merged in one merging region through independent inlet channels, and were allowed to flow out through one mixing channel. In addition, a buffer solution that acts as a good solvent for the fine particle forming material and is approximately compatible with the poor solvent is merged from another inlet channel to the merge region, and the material solution and poor solution are merged in the merge region. A buffer liquid phase was formed between the phase for precipitation consisting of a solvent and the phase of a functional solution containing a functional agent (for example, a dispersant). The combined liquids flow through the mixing channel and mix with each other, and then are discharged.

  As a result, the phase of the buffer liquid can delay the timing (timing) at which the precipitated particles and the dispersant come into contact with each other, so that the particle nuclei and the dispersant can be prevented from contacting at the initial stage of particle formation. It becomes possible to adsorb the dispersant on the particle surface by bringing the particles after the formation, that is, after the growth, into contact with the dispersant. As a result, since the functional part of the dispersant is not taken into the inside of the particle, a dispersing function commensurate with the amount of dispersant used can be exhibited. The degree to which the timing of contact between the particles and the dispersant is delayed can be appropriately adjusted by changing the phase thickness of the buffer solution.

  Therefore, by carrying out the method for producing fine particles of the present invention, a sufficient function can be exhibited with a small amount of a functional drug, so that the cost of the drug can be reduced, and this can be achieved with a single micro drug. It can be realized with a device. The present invention can be applied to various kinds of fine particle production, and is particularly effective when producing organic pigment fine particles.

    In the present invention, it is more preferable to sandwich the material solution with a poor solvent in the merge region. The equivalent diameters of the independent inlet channel and the mixing channel are preferably in the range of 0.5 to 6 mm. The volume flow ratio of the material solution and the poor solvent is in the range of 1: 0.5 to 1: 2, and the volume flow ratio of the material solution and the dispersant solution is in the range of 1: 1 to 1: 100. The volume flow rate ratio of the material solution and the buffer solution is preferably in the range of 1: 0.5 to 1: 2.

  According to the fine particle production method of the present invention, a sufficient function can be exhibited with a small amount of a functional drug, so that the cost of the drug can be reduced and the apparatus can be realized with a single micro device. Cost can be reduced.

  Hereinafter, preferred embodiments of a method for producing fine particles according to the present invention will be described with reference to the accompanying drawings.

  In the following embodiment, an example in which organic pigment fine particles are produced using an organic pigment as a fine particle forming material and a dispersant as a functional agent will be described.

(Micro device)
First, the preferable aspect of the microdevice for enforcing the microparticle manufacturing method of this invention is demonstrated.

  FIG. 1 is a cross-sectional view of a device body 10 of a micro device, and FIG. 2 is a vertical cross-sectional view taken along the line aa.

  As shown in these drawings, the device main body 10 of the micro device has a joining region 14 formed at a substantially central portion of the surface of the substrate 12, and five inlet grooves 16a, 16b, 16c, 16d centering on the joining region 14. 16e and one mixing groove 18a are formed radially. Then, as shown in FIG. 2, the cover plate 20 is put on the substrate 12 to be integrated, so that the five inlet channels 16A, 16B, 16C, 16D, and 16E, and one mixing channel. 18 are formed.

  A through-hole penetrating in the thickness direction is formed in the cover plate 20 at a position corresponding to the inlet side end portions of the inlet grooves 16a to 16e and the outlet side end portion of the mixing groove 18a. FIG. 2 shows the through holes 22 and 24 of the inlet channel 16C and the mixing channel 18 among the through holes.

  Then, the four liquids L1 to L4 introduced from the five inlet channels 16A to 16E are, in order from the left side of FIG. 1, the poor solvent L2, the pigment solution L1 (material solution), the poor solvent L2, and the organic solvent. The supply lines 26A, 26B, 26C, 26D, and 26E of the liquids L1 to L4 are connected to the through holes so that the buffer liquid L4 and the dispersant solution L3 (functional solution) are obtained. For supplying the liquids L1 to L4 to the inlet channels 16A to 16E, a supply unit (not shown) (for example, a micro syringe pump) is used. Of the supply lines 26A to 26E for the liquids L1 to L4, at least the supply line 26D for the buffer solution L4 is preferably provided with a supply amount adjusting means 28 for adjusting the supply amount of the buffer solution L4. In FIG. 1, the supply amount adjusting means 28 is provided only in the supply line 26D of the buffer solution L4, but it may be provided in other lines.

  The channel widths of the inlet channels 16A to 16E are not particularly limited. For example, the equivalent diameter is preferably about 1 mm or less, but a pigment solution that is a slurry solution in which an organic pigment is dissolved in a good solvent is used. It is necessary to flow so as not to clog the flow path. For example, the viscosity of the pigment solution is preferably 20 cP or less, and more preferably 5 cP or less. When the viscosity is 20 cP or less, the channel width of the inlet channels 16A to 16E is preferably in the range of 0.5 mm to 6 mm, and more preferably in the range of 0.5 mm to 2 mm.

  The channel width of the mixing channel 18 can be 0.5 mm to 6 mm, more preferably 1 mm to 6 mm, and particularly preferably 2 mm to 6 mm in terms of equivalent diameter.

Equivalent diameter, also called equivalent (straight) diameter, 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 (deq) is defined as deq = 4 A / p, using A: cross-sectional area of the pipe and p: 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 deq = 4a ² / 4a = a for a regular square tube with one side a, deq = a / √3 for a regular triangle tube with one side a, and deq = 2h for a flow between parallel plates with a channel height h. (For example, see "Mechanical Engineering Encyclopedia" edited by Japan Society of Mechanical Engineers, 1997, Maruzen Co., Ltd.).

  The length L of the mixing channel 18 (the length from the inlet 18b to the through-hole 24 of the mixing channel 18) is preferably a length that can completely complete the reaction from the precipitation of particles to dispersion. Moreover, it is preferable that the width | variety of the confluence | merging area | region 14 does not exceed 30 mm at maximum.

  The cross-sectional shapes of the inlet channels 16A to 16E and the mixing channel 18 are not limited to rectangles, but may be semicircular, circular, V-shaped, elliptical, trapezoidal, or the like.

  The device body 10 of the micro device can be manufactured using precision processing techniques such as micro drilling, micro electric discharge machining, molding using plating, injection molding, dry etching, wet etching, and hot embossing.

  The material of the apparatus main body 10 is not particularly limited as long as it has corrosion resistance to various solutions to be used and can apply the above processing technique. Specifically, metal materials (iron, aluminum, stainless steel, titanium, various metals, etc.), resin materials (acrylic resin, PDMS, etc.), glass (silicon, Pyrex (registered trademark), quartz glass, etc.), quartz Glass or Pyrex (registered trademark) glass subjected to parylene (paraxylene vapor deposition) treatment, or fluorine or hydrocarbon silane coupling treatment can be suitably used.

  Moreover, a heating means (not shown) for heating the apparatus main body 10 is provided as necessary. As such a heating means, there is a method in which a heater structure such as a metal resistance wire or polysilicon is built in the apparatus main body. In the case of a heater structure such as a metal resistance wire or Polysilicon, this is used for heating, and the temperature is controlled by performing a thermal cycle with natural cooling for cooling. For temperature sensing in this case, in the case of a metal resistance wire, make another same resistance wire, detect the temperature based on the change in the resistance value, and in the case of Polysilicon, use a thermocouple. A method for detecting the temperature by using this method is generally employed. Further, a temperature control function using a Peltier element may be incorporated in the apparatus main body.

  Next, the microparticle production method of the present invention will be described using the microdevice configured as described above.

  First, each liquid L1-L4 used by this invention is prepared.

  The pigment solution L1 is prepared as a slurry solution in which a solid substance of an organic pigment is moistened with a good solvent. In the build-up process in which fine particles are precipitated and generated, it is necessary to completely dissolve the organic pigment to the molecular level. For this reason, it is preferable to prepare a pigment solution L1 in which an organic pigment is completely dissolved in a good solvent by adding an acid or an alkali agent to the slurry solution.

  Also, the poor solvent L2 that is compatible with the good solvent of the pigment solution L1 but does not dissolve the organic pigment, the dispersant solution L3 containing the dispersant as a solvent, and a poor solvent that acts on the organic pigment as a good solvent. A buffer solution L4 that is approximately compatible with the solvent L2 is prepared. In addition, substantially compatible or more means having compatibility of 50% by mass or more, more preferably 80% by mass or more, and further preferably 95% by mass or more.

  Then, as shown in FIG. 3 (A), the pigment solution L1, the poor solvent L2, the dispersant solution L3, and the buffer solution L4 are introduced from the respective inlet channels 16A to 16E. The phase of the buffer solution L4 is merged between the phase for precipitation of particle nuclei composed of the pigment solution L1 and the poor solvent L2 and the phase of the dispersant solution L3 containing the dispersant.

  FIG. 3B schematically shows the phases formed by the liquids at the inlet position 18 b of the mixing channel 18 from the merge region 14. In the present embodiment, using the five inlet channels 16A to 16E, both sides of the phase of the pigment solution L1 are sandwiched between a pair of poor solvents L2, and one of the poor solvent L2 and the dispersant solution L3 are sandwiched. A phase of buffer solution L4 was formed between the two phases.

  The combined liquids L <b> 1 to L <b> 4 are mixed with each other while flowing through the mixing flow path 18 to form the fine particle dispersion LM and flow out of the apparatus main body 10. That is, by mixing the phase of the pigment solution L1 and the phase of the poor solvent L2 in the mixing channel 18, the solubility of the organic pigment in the pigment solution L1 is lowered, so that the particle nuclei of the pigment particles are precipitated. (Nucleation field). Further, the phase of the pigment solution L1 and the poor solvent L2 and the phase of the buffer solution L4 are mixed, so that the precipitated particle nuclei form a buffer solution L4 that acts as a good solvent for the organic pigment while growing particles. Captured (growth field). Further, by mixing the phase of the buffer solution L4 and the phase of the dispersant solution L3, the particles formed by contact between the grown particles and the dispersant are dispersed so as not to aggregate (dispersion field).

  Although the mixing of the phases in the mixing channel 18 proceeds simultaneously, a phase of the buffer solution L4 is formed between the phase of the pigment solution L1 and the poor solvent L2 and the phase of the dispersant solution L3 in the merge region 14. By merging as described above, the phase (timing) at which the phase of the buffer liquid L4 comes into contact with the particle nuclei that precipitate in the initial stage of particle formation and the dispersant can be delayed. In this case, how much the timing is delayed is adjusted by controlling the phase thickness of the buffer solution L4. As a guideline for adjustment, it is preferable that the time from the growth of the particle nuclei formed in the nucleation field to the dispersion in the dispersion field with the dispersant is in the range of 0.1 to 10 msec. If it is less than 0.1 msec, the dispersant is likely to come into contact with the particle nuclei at the initial stage of particle formation, so that the dispersant is easily taken into the grown particles. On the other hand, if it exceeds 10 msec, aggregation of the grown particles is promoted and monodispersed fine particles cannot be obtained.

  As a result, the functional part of the dispersant is not taken into the inside of the particles as shown in FIG. 4 (A) as in the conventional case where the dispersant is previously contained in the pigment solution L1. ) To be exposed from the particle surface. Therefore, according to the method for producing fine particles of the present invention, a dispersion function commensurate with the amount of dispersant used can be exhibited.

  Further, in the present invention, by using the buffer liquid L4, the liquids L1 to L4 are merged in one merging region 14 via the respective inlet channels 16A to 16E, and one mixed flow is generated from the merging region 14. Since it can flow out through a channel | path, the microparticle manufacturing method of this invention is realizable with a single microdevice.

  In addition, in the apparatus main body 10 of FIG. 1, although it showed by the case where five inlet flow paths and one mixing flow path extended radially centering on a confluence | merging area | region, it is not limited to this. It is sufficient that there are at least four inlet channels for allowing the liquids L1 to L4 to flow in, a merging region, and one mixing channel, and the relationship between the channels does not have to be radial.

  Next, various materials used in this embodiment will be described.

(Organic pigment)
The organic pigment used in the present embodiment is not limited in hue, and may be a magenta pigment, a yellow pigment, or a cyan pigment. Specifically, perylene, perinone, quinacridone, quinacridonequinone, anthraquinone, anthanthrone, benzimidazolone, disazo condensation, disazo, azo, indanthrone, phthalocyanine, triarylcarbonium, dioxazine, aminoanthraquinone, diketopyrrolopyrrole, thioindigo, Magenta pigments such as 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. 20055), 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 C.I. Pigment Brown 23 (C.I. No. 20006); 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. 73312); 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. I. Pigment Orange 61 (C.I. No. 11295) and other isoindolinone pigments, 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).

  Particularly preferred pigments are quinacridone, diketopyrrolopyrrole, disazo condensation, azo, phthalocyanine, and dioxazine pigments.

(Dispersant)
As the dispersant used in the present embodiment, the following can be used.

  Examples of anionic dispersants (anionic surfactants) include N-acyl-N-alkyltaurine salts, fatty acid salts, alkylsulfuric acid ester salts, alkylbenzene sulfonates, anionic sulfonates (trade name Aqualon KH10: Daiichi Industrial pharmaceuticals), alkyl naphthalene sulfonates, dialkyl sulfosuccinates, alkyl phosphate esters, naphthalene sulfonate formalin condensates, polyoxyethylene alkyl sulfates, and the like. Of these, N-acyl-N-alkyltaurine salts are preferred. As the N-acyl-N-alkyl taurine salts, those described in JP-A-3-273067 are preferable. These anionic dispersants can be used alone or in combination of two or more. 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 singly 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 singly or in combination of two or more.

  The organic pigment dispersant is defined as an organic pigment dispersant which is derived from an organic pigment as a parent substance and is produced by chemically modifying the parent structure. For example, sugar-containing organic pigment dispersants, piperidyl-containing organic pigment dispersants, naphthalene or perylene-derived organic pigment dispersants, organic pigment dispersants having a functional group linked to the organic pigment parent structure via a methylene group, polymer chemistry Modified organic pigment parent structure, organic pigment dispersant having sulfonic acid group, organic pigment dispersant having sulfonamide group, organic pigment dispersant having ether group, or carboxylic acid group, carboxylic ester group or carboxamide group And organic pigment dispersants.

  Specific examples of the polymer dispersant include polyvinyl pyrrolidone, polyvinyl alcohol, polyvinyl methyl ether, polyethylene oxide, polyethylene glycol, polypropylene glycol, polyacrylamide, vinyl alcohol-vinyl acetate copolymer, polyvinyl alcohol partially formalized product, polyvinyl Alcohol partially butyralized, 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-acrylate copolymer, Methacrylate-methacrylate copolymer, Styrene-itaconate copolymer, Itaconic ester-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. Further, an embodiment in which an anionic dispersant is contained in an aqueous medium and a nonionic dispersant and / or a polymer dispersant is contained in a solution in which an organic pigment is dissolved can be exemplified.

  In order to further improve the uniform dispersibility and storage stability of the organic pigment, the blending amount of the dispersant is preferably in the range of 0.1 to 1000 parts by weight, more preferably 100 parts by weight of the organic pigment. Is in the range of 1 to 500 parts by weight, more preferably in the range of 10 to 250 parts by weight. If the amount is less than 0.1 parts by mass, the dispersion stability of the organic pigment fine particles may not be improved.

  In the fine particle production method described in each of the above embodiments, the organic pigment fine particles are produced. However, the fine particle production method and apparatus of the present invention can be applied to various reactions. Other fine particle forming materials include titanium dioxide, calcium carbonate, copper oxide, aluminum oxide, iron oxide, chromium oxide, bismuth vanadate, rutile mixed phase pigment, silver halide, silica, and carbon black. It is not limited to these.

  The organic pigment must be uniformly dissolved in an alkaline or acidic aqueous medium, but whether it dissolves in acid or alkaline is selected depending on which conditions the target pigment is easily dissolved . Generally, in the case of a pigment having an alkaline and dissociable group in the molecule, alkalinity is used. Alternatively, when there is no alkaline dissociating group and there are many nitrogen atoms in the molecule to which protons can easily be added, acidity is used. For example, quinacridone, diketopyrrolopyrrole, and disazo condensation pigments are alkaline, and phthalocyanine pigments are acidic.

  Bases used for alkaline dissolution are inorganic bases such as lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, or barium hydroxide, or trialkylamine, diazabicycloundecene (DBU), An organic base such as a metal alkoxide is preferable, but an inorganic base is preferable.

  The amount of the base used is an amount capable of uniformly dissolving the pigment, and is not particularly limited, but in the case of an inorganic base, it is preferably 1.0 to 30 molar equivalents relative to the pigment, more preferably 2. It is 0-25 molar equivalent, More preferably, it is 3-20 molar equivalent. In the case of an organic base, it is preferably 1.0 to 100 molar equivalents relative to the pigment, more preferably 5.0 to 100 molar equivalents, and even more preferably 20 to 100 molar equivalents.

  The acid used for the acid dissolution is an inorganic acid such as sulfuric acid, hydrochloric acid, or phosphoric acid, or an organic acid such as acetic acid, trifluoroacetic acid, oxalic acid, methanesulfonic acid, or trifluoromethanesulfonic acid, preferably Is an inorganic acid. Particularly preferred is sulfuric acid.

The amount of the acid used is an amount capable of uniformly dissolving the pigment, and is not particularly limited, but is often used in an excessive amount as compared with the base. Regardless of an inorganic acid or an organic acid, it is preferably 3 to 500 molar equivalents, more preferably 10 to 500 molar equivalents, and further preferably 30 to 200 molar equivalents with respect to the pigment.
In this embodiment, the example of the dispersant is described as the functional drug. However, the present invention can be applied to all drugs that exhibit a function on the particle surface, and examples thereof include pigment derivatives and particle growth inhibitors.

(Buffer solution)
The buffer solution acts as a good solvent for the organic pigment, and an organic solvent that is substantially compatible with the poor solvent (for example, water), that is, an organic solvent that is compatible with 50% by mass or more at an arbitrary ratio. It is preferably 80% by mass or more, more preferably 95% by mass or more. For example, the buffer solution is preferably an aprotic solvent such as N-methylpyrrolidone (NMP), dimethyl sulfoxide (DMSO), dimethylformamide (DMF), or acetonitrile. As a specific example, when water is used as the poor solvent, dimethyl sulfoxide (DMSO) can be suitably used as the buffer solution.

  The compatibility between the buffer solution L4 and the organic solvent of the dispersant solution L3 is preferably at least 50% by mass, more preferably 70% by mass or more, and still more preferably complete mixing at an arbitrary ratio. Is preferred. For example, as the organic solvent for the dispersant solution, PGMEA (propylene glycol monomethyl ether acetate), ethyl lactate, ethyl acetate, MEK (methyl ethyl ketone) and the like are preferable.

(Volume flow ratio of each liquid)
The volume flow rate ratio of the pigment solution L1, water (poor solvent) L2, the dispersant solution L3, and the buffer solution L4 preferably has the following relationship when the flow rate of the pigment solution L1 is 1. The volume flow rate ratio between the pigment solution L1 and the water (poor solvent) L2 is preferably in the range of 1: 0.5 to 1: 2. Moreover, the volume flow rate ratio of the pigment solution L1 and the dispersant solution L3 is preferably in the range of 1: 1 to 1: 100. Furthermore, the volume flow rate ratio of the pigment solution L1 and the buffer solution L4 is preferably in the range of 1: 0.5 to 1: 2. However, the flow rate required for mixing (the total of L1 to L3 or L1 to L4) is preferably defined by the Reynolds number at the time when the liquids merge, that is, the Reynolds number at the outlet of the mixing channel, and the outlet Reynolds changes. Otherwise, it is possible to change the volume flow rate ratio. The exit Reynolds number is preferably 2000 or more, and more preferably 10,000 or more.

  The micro device 10 is not particularly limited, but a structure having a plurality of channels such as a micro device having four channels (FIG. 1) and a micro device having six channels (FIG. 4) is required.

  The fine particle production method of the present invention will be described in more detail based on the following examples, but the present invention is not limited to these examples.

  In Examples, organic pigment fine particles were produced using the microdevice shown in FIG. As the microdevice, a fine particle manufacturing apparatus provided with a rectangular mixing channel of 0.5 mm in length and width was used. In addition, by using a cover plate formed of a transparent resin for the apparatus main body, the phase formation state in the merge region and the mixing channel can be observed with a microscope.

  The pigment solution L1, the poor solvent L2, the dispersant solution L3, and the buffer solution L4 were prepared as follows.

(1) Preparation method of pigment solution L1 PR122 powder which is one of magenta was used as the pigment. This was dissolved in 5% by mass with dimethyl sulfoxide (DMSO) which is an aprotic solvent which is a good solvent to form a slurry. Further, SM28 (28% by mass sodium methoxide methanol solution), which is one of alkali agents, was completely dissolved in a molecular state to obtain a pigment solution L1.

  (2) Distilled water was used as the poor solvent L2.

(3) Preparation of dispersant solution L3
Dispersant polyvinyl pyrrolidone K25 and Solsperse 24000 (manufactured by Avecia) were contained in an organic solvent PGMEA as a dispersion solvent so as to have a total mass of 5% by mass to obtain a dispersant solution L3.

(4) The above dimethyl sulfoxide (DMSO) was used as the buffer solution L4. (5) Reaction conditions i) Set flow rate: Using a micro syringe pump (manufactured by Harvard), dissolved solution L1 was 20 mL / min, and poor solvent L2 was used. 40 mL / min, dispersant solution L3 was supplied at a constant flow rate of 100 mL / min, and buffer solution was supplied at a constant flow rate of 10 mL / min.

  ii) Reaction temperature: The test was carried out continuously at 18 ° C. for 20 hours.

  As a comparative example, when a dispersant is contained in the pigment solution, a Y-channel microdevice is used, and the pigment solution containing the dispersant and the poor solvent are placed on the top of the Y-channel. After being flown in from the first flow channel and merged in the merge region, it was discharged from one lower flow channel of the Y-shaped flow channel.

  The amount of dispersant used was the same in both the examples and comparative examples. Then, the particle size and monodispersity (Mv / Mn) of the pigment fine particles produced in Examples and Comparative Examples were measured using Nanotrack UPA-EX150 manufactured by Nikkiso Co., Ltd., and the median average diameter and arithmetic standard deviation were measured. It was measured.

  As a result, in the examples, the particle diameter of the organic pigment fine particles was 20.6 nm, and the monodispersity (Mv / Mn) was 1.33.

  In the comparative example, the organic pigment fine particles had a particle size of 35.5 nm and a monodispersity (Mv / Mn) of 1.70.

  Further, when the pigment fine particles of the examples and comparative examples were measured by NMR, in the case of the comparative examples, the ratio of the functional part of the dispersant incorporated in the pigment particles was large.

It is a top view which shows an example of the apparatus main body of the microdevice which implements this invention. It is the a-a 'line sectional view of the microdevice of Drawing 1. It is an expansion schematic diagram which shows typically the effect | action of the manufacturing method of this invention. It is a schematic diagram which shows the relationship between the particle | grains and a dispersing agent in the past and this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Micro device main body, 12 ... Board | substrate, 14 ... Merge area | region, 16A-16E ... Inlet flow path, 18 ... Mixing flow path, L1 ... Pigment solution, L2 ... Poor solvent, L3 ... Dispersant solution, L4 ... Buffer solution, LM ... Fine particle dispersion

Claims (7)

A material solution obtained by dissolving a fine particle forming material in a solvent, a poor solvent that lowers the solubility of the fine particle forming material in the material dissolving solution to precipitate particles of the fine particle forming material, and a surface of the particles to be precipitated A functional solution containing a functional drug that exhibits a function in a portion, and a buffer solution that acts as a good solvent for the fine particle forming material and is substantially compatible with the poor solvent or more, are independent of each other. Merging at one merging region via the inlet channel, flowing out from the merging region through one mixing channel,
In the merging region, fine particles are produced by merging so that the phase of the buffer solution is formed between the phase composed of the material solution and the poor solvent and the phase of the functional solution. Method.   The method for producing fine particles according to claim 1, wherein the functional agent is at least one of a dispersant, a pigment derivative, and a particle growth inhibitor.   3. The fine particle production according to claim 1, wherein a time for mixing the material solution, the poor solvent phase and the functional solution phase is controlled by changing a phase thickness of the buffer solution. Method.   The method for producing fine particles according to any one of claims 1 to 3, wherein, in the merging region, the material solution is sandwiched between the poor solvents.   5. The method for producing fine particles according to claim 1, wherein an equivalent diameter of each of the independent inlet channel and the mixing channel is in a range of 0.5 to 6 mm.   The method for producing fine particles according to claim 1, wherein the fine particle forming material is an organic pigment.   The volume flow ratio of the material solution to the poor solvent is in the range of 1: 0.5 to 1: 2, and the volume flow ratio of the material solution to the dispersant solution is from 1: 1 to 1: 100. The volumetric flow rate ratio between the material solution and the buffer solution is in the range of 1: 0.5 to 1: 2, and the fine particles according to any one of claims 1 to 6 Production method.

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