JP2007262162A - Method of producing organic pigment fine particle, organic pigment fine particle and pigment ink using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable production of a pigment fine particle which has a production suitability and is excellent in monodispersity through a build-up method. <P>SOLUTION: A plurality of kinds of solution is reacted through a liquid phase method in a mixing field 20, and at least one of the plurality of kinds of solution is supplied to the mixing field 20 by a high-pressure jet stream. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing organic pigment fine particles, organic pigment fine particles, and pigment inks using the same, and in particular, organic pigment fine particles used for paints, printing inks, electrophotographic toners, inkjet inks, color filters and the like. The present invention relates to a production method, organic pigment fine particles, and pigment ink using the same.

  Conventionally, pigments used in printing inks, paints, and the like include fine particles obtained by pulverizing coarse pigment particles. In order to obtain the color reproducibility of the pigment particles, it is a problem to make the size of the pigment particles after pulverization uniform, and various studies have been made regarding the pulverization method of the pigment particles.

  For example, as one of the above pulverization methods, a pulverization method using a bead mill can be cited. This pulverization method is a method in which a raw material is put into a vessel (container) filled with beads (media), a central rotating shaft is rotated to flow the beads, and the raw material is crushed, pulverized and dispersed. However, the pulverization method using a bead mill has a lot of contamination and is difficult to separate from the raw material (especially when the beads have a small diameter), and there are raw materials that are not crushed by the beads, so the particle size distribution is broadened and the viscosity of the raw material is increased. There was a problem that it was easy to go up.

  Another pulverization method includes a collision pulverization method. This pulverization method is a method in which particles are collided to form fine particles. For example, a method in which a pigment dispersion is ejected as a high-speed flow and collided to be pulverized to form fine particles (Patent Document 1), or a mixture containing pigment is passed through an orifice at 100 to 1000 m / second, and then the mixture is mixed. A method of forming fine particles by high-pressure emulsification ejected inside (Patent Document 2) has been proposed. However, in the impact pulverization method, variation in kinetic energy given to particles tends to cause non-uniform particle size, and collision is performed stochastically. There was a problem that it was necessary.

  As means for solving these problems, a method for producing fine particles called a build-up method has been proposed. This build-up method is a method in which particles are produced from molecules by chemical reaction instead of pulverizing the particles. In this method, it is important to make the chemical reaction field uniform in order to make the particle size uniform.

  Patent Document 3 proposes a method of producing pigment fine particles in a minireactor. According to this, it is said that the reaction field can be made uniform by reducing the chemical reaction field.

Patent Document 4 proposes a method for producing an azo colorant by spraying a plurality of reaction liquids into a gas phase with a nozzle in a microjet mixer.
Japanese Patent Laid-Open No. 10-36738 JP 2003-20427 A Special table 2003-524033 gazette JP 2002-129050 A

  However, the conventional build-up method as shown in Patent Document 3 has a problem that the produced fine particles accumulate in the reactor and cause clogging (low production suitability). In Patent Document 4, gas is introduced into the reaction chamber to prevent the above-mentioned blockage. However, since gas-liquid separation is necessary in the subsequent process, the process becomes complicated and the production suitability is lowered. was there.

  The present invention has been made in view of such circumstances, and has a production suitability, a method for producing organic pigment fine particles capable of producing organic pigment fine particles having excellent monodispersibility by a build-up method, organic pigment fine particles, And a pigment ink using the same.

  According to a first aspect of the present invention, in order to achieve the object, a plurality of types of solutions are reacted in a mixing field by a liquid phase method, and at least one of the plurality of types of solutions is supplied into the mixing field by a high-pressure jet flow. The present invention provides a method for producing fine organic pigment particles.

  According to the first aspect, a plurality of types of solutions are reacted in the mixing field by a liquid phase method, and at least one of the plurality of types of solutions is supplied into the mixing field by a high-pressure jet flow to be reacted. As a result, a high shear field can be formed in the mixing field, and a plurality of types of solutions can be mixed instantaneously, so that the reaction can be made uniform and adhesion of deposits to the inner wall surface of the mixing field can be suppressed. Therefore, pigment fine particles that are suitable for production and excellent in monodispersibility can be produced by a build-up method. Here, the liquid phase method means a reaction method in which all of the fluid supplied to the mixing chamber is a liquid, or a liquid in which bubbles or particles are suspended in the liquid.

  A second aspect of the present invention is the method according to the first aspect, wherein the reaction is a precipitation reaction.

  Thus, in the precipitation reaction, the mixing field is likely to be blocked due to the formation of precipitates, and the present invention is particularly effective.

  Here, the precipitation reaction is a reaction in which a solid is mainly produced from a solution or a solution of a certain substance. For example, the precipitation of the compound is caused by temperature change, pH change, solvent amount / mixing ratio change, etc. Many things are caused by a decrease in solubility, and include recrystallization and reprecipitation.

  A third aspect is characterized in that, in the second aspect, the precipitation reaction is a precipitation reaction due to a change in solubility and / or a change in pH.

  As described above, the present invention is particularly effective in the method for producing organic pigment fine particles utilizing the precipitation reaction due to the solubility change and / or the pH change. As the precipitation reaction as described above, for example, an organic pigment solution uniformly dissolved in an alkaline or acidic aqueous medium, more preferably an alkaline aqueous medium, and an aqueous medium that does not dissolve the organic pigment are mixed, and both solutions are mixed. Examples thereof include a method of depositing organic pigment fine particles by changing the hydrogen ion index (pH).

  A fourth aspect of the present invention is characterized in that, in any one of the first to third aspects, an ejection pressure of the high-pressure jet stream supplied into the mixing field is 1 MPa to 200 MPa.

  A fifth aspect of the present invention is characterized in that, in any one of the first to fourth aspects, a flow velocity of the high-pressure jet flow supplied into the mixing field is 50 m / sec to 700 m / sec.

  A sixth aspect of the present invention is characterized in that, in any one of the first to fifth aspects, a Reynolds number Re in the vicinity of a jet outlet of the high-pressure jet flow supplied into the mixing field is 2100 to 150,000.

  Claims 4 to 6 define preferable operating conditions of the high-pressure jet flow in order to ensure mixing performance between a plurality of solutions and suppress excessive heat generation and the like.

  By setting the amount within the above range, pigment fine particles that are suitable for production and excellent in monodispersity can be produced by a build-up method.

  A seventh aspect according to any one of the first to sixth aspects, wherein the ratio D / d of the equivalent circle diameter d of the jet outlet of the high-pressure jet flow supplied into the mixing field and the equivalent circle diameter D of the mixing field. Is 5-30.

  The seventh aspect defines an apparatus configuration for forming a high-pressure jet flow for ensuring mixing performance between a plurality of solutions.

  An eighth aspect of the present invention is characterized in that, in any one of the first to seventh aspects, the collision angle between at least one high-pressure jet stream and a solution other than the high-pressure jet stream is 0 ° to 90 °.

  Since mixing is performed such that the collision angle between at least one high-pressure jet stream and a solution other than the high-pressure jet stream is 0 ° to 90 °, high mixing performance can be ensured.

  Therefore, pigment fine particles that are suitable for production and excellent in monodispersibility can be produced by a build-up method.

  A ninth aspect is characterized in that, in any one of the first to eighth aspects, one of the plurality of solutions is a high-pressure jet stream.

  According to claim 9, by adopting a one-jet system, an organic pigment having excellent monodispersibility, which ensures mixing performance among a plurality of solutions and suppresses excessive heat generation and the like as in claims 4-6. Fine particles can be generated. Further, by limiting the jet flow to one liquid, there is no problem in operation in terms of design for preventing erosion of the apparatus due to the jet flow, and the equipment cost can be reduced.

  The organic pigment fine particles according to claim 10 are manufactured by using the method for manufacturing organic pigment fine particles according to any one of claims 1 to 9.

  According to the tenth aspect, organic pigment fine particles having excellent monodispersibility can be obtained.

  An eleventh aspect is characterized in that, in the tenth aspect, a particle size distribution Mv / Mn of the organic pigment fine particles is 1.55 or less. Here, Mv is a volume average particle diameter, and Mn is a number average particle diameter. Mv / Mn is used as an index of particle size distribution, and the closer the value is to 1, the higher the monodispersity.

  According to the eleventh aspect, it is possible to obtain organic pigment fine particles having excellent monodispersity, which are produced by the method for producing organic pigment fine particles according to any one of the first to ninth aspects.

  A pigment ink according to a twelfth aspect uses the organic pigment fine particles according to the tenth or eleventh aspect.

  According to the twelfth aspect, a pigment ink having excellent dispersibility and color reproducibility can be obtained.

  According to the present invention, it is possible to produce organic pigment fine particles that are suitable for production and excellent in monodispersibility by a build-up method.

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

  First, the reaction for depositing the organic pigment fine particles according to the present invention and various materials will be described. The reaction for forming the organic pigment fine particles is not limited to this embodiment.

Organic pigment fine particles are produced by bringing an organic pigment solution in which an organic pigment is dissolved into contact with a liquid that does not dissolve the organic pigment (for example, an aqueous medium), and depositing the organic pigment that has become insoluble as organic pigment fine particles (so-called Coprecipitation method (reprecipitation method)) and the like.
Specific examples of the precipitation reaction include a precipitation reaction due to a change in pH and a precipitation reaction due to a change in solubility. In addition, in the above precipitation method, there is also a method for producing stable fine particles by allowing a dispersant to coexist in any solution.

  In the present embodiment, a precipitation reaction involving pH change and solubility change, that is, an organic pigment solution uniformly dissolved in an alkaline or acidic aqueous medium and an aqueous medium that does not dissolve the organic pigment are supplied into the mixing field, and the process The method of depositing organic pigment fine particles by changing the hydrogen ion index (pH) of both solutions will be described.

  Specifically, a homogeneous organic pigment solution (solution L1) and neutral, acidic or alkaline water, or an aqueous solution in which a dispersant is dissolved (solution L2) are respectively introduced into a mixing field, and both solutions are introduced. By contacting, the hydrogen ion concentration of the solution containing the organic pigment, that is, the hydrogen ion index (pH) is changed in the neutral (pH 7) direction.

  Thus, by mixing the solution L1 and the solution L2, the hydrogen ion index (pH) of the solution L1 changes in the neutral direction. A pigment is difficult to dissolve in an aqueous medium when it has low alkalinity or low acidity, and therefore, the pigment precipitates as fine particles when the hydrogen ion index (pH) changes in a neutral direction.

  The change in the hydrogen ion index (pH) is generally a change within the range of pH 16.0 to 5.0 when organic pigment fine particles are produced from a pigment dissolved in an alkaline aqueous medium. The change is preferably within a range of 10.0. When producing pigment fine particles from a pigment dissolved in an acidic aqueous medium, the change is generally in the range of pH 1.5 to 9.0, and in the range of pH 1.5 to 4.0. It is preferable. The width of the change depends on the value of the hydrogen ion exponent (pH) of the organic pigment solution, but may be sufficient to promote the precipitation of the organic pigment.

  The reaction temperature in the mixing field when producing organic pigment fine particles is preferably within the range where the solvent does not coagulate or vaporize, but is preferably -20 ° C to 90 ° C, preferably 0 ° C to 50 ° C. It is more preferable.

  The concentration range of the substrate (organic pigment and its reaction components) flowing through the mixing field is usually 0.5% by mass to 20% by mass, and preferably 1.0% by mass to 10% by mass.

  Next, various materials used for the above-described organic pigment fine particle precipitation reaction will be described.

  The organic pigment used in the present embodiment is not limited in hue, and includes a magenta pigment, a yellow pigment, or a cyan pigment. Specific examples include perylene, perinone, quinacridone, quinacridone quinone, anthraquinone, anthanthrone, benzimidazolone, disazo condensation, disazo, azo, indanthrone, phthalocyanine, triarylcarbonium, dioxazine, aminoanthraquinone, diketopyrrolo Magenta pigments such as pyrrole, thioindigo, isoindoline, isoindolinone, pyranthrone or isoviolanthrone pigments or mixtures thereof, yellow pigments, cyan pigments, and the like can be used.

  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. Isoviolanthrone pigments such as CI Pigment Violet 31 (60010) can be used.

  The organic pigment is preferably a quinacridone, diketopyrrolopyrrole, disazo condensation, or phthalocyanine pigment, more preferably a quinacridone, disazo condensation, or phthalocyanine pigment. Two or more kinds of organic pigments, solid solutions of organic pigments, or combinations of organic pigments and inorganic pigments can also be used.

  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 under which conditions the target pigment is easily dissolved . Generally, in the case of a pigment having an alkaline and dissociable group in the molecule, the alkalinity is used, and when there are no groups that are alkaline and dissociable and there are many nitrogen atoms in the molecule that are prone to add protons, the acidity is used. It is done. For example, quinacridone, diketopyrrolopyrrole, and disazo condensation pigments are dissolved in an alkaline manner, and phthalocyanine pigments are dissolved in an acidic manner.

  The base used for the alkaline dissolution is an inorganic base such as sodium hydroxide, calcium hydroxide, or barium hydroxide, or an organic base such as trialkylamine, diazabicycloundecene (DBU), or metal alkoxide. Is preferably an inorganic base.

  The amount of the base used is an amount capable of uniformly dissolving the organic pigment and is not particularly limited. However, in the case of an inorganic base, it is preferably 1.0 to 30 molar equivalents relative to the pigment. It is more preferably from 0 to 25 molar equivalents, and further preferably from 3 molar equivalents to 20 molar equivalents. 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 further preferably 20 to 100 molar equivalents. preferable.

  Acids used for acidic dissolution are inorganic acids such as sulfuric acid, hydrochloric acid, or phosphoric acid, or organic acids such as acetic acid, trifluoroacetic acid, oxalic acid, methanesulfonic acid, or trifluoromethanesulfonic acid. An acid is preferable, and sulfuric acid is more preferable.

  The amount of the acid used is an amount capable of uniformly dissolving the organic pigment, and is not particularly limited, but is often used in an excessive amount as compared with the base. Regardless of inorganic acid or organic acid, it is preferably 3 to 500 molar equivalents, more preferably 10 to 500 molar equivalents, and more preferably 30 to 200 molar equivalents with respect to the pigment. More preferably it is.

  The aqueous medium used in the present embodiment is a solvent in which a pigment is dissolved with an alkali or an acid and is further soluble with water. Specifically, it is water alone or an organic solvent soluble in water.

  Examples of water-soluble organic solvents include monovalent alcohol solvents such as methanol, ethanol, isopropanol, and t-butanol, ethylene glycol, propylene glycol, diethylene glycol, polyethylene glycol, thiodiglycol, dithiodiglycol, A polyhydric alcohol solvent represented by 2-methyl-1,3-propanediol, 1,2,6-hexanetriol, acetylene glycol derivative, glycerin, or trimethylolpropane, ethylene glycol monomethyl (or ethyl) ether, Lower monoalkyl ether solvents of polyhydric alcohols such as diethylene glycol monomethyl (or ethyl) ether or triethylene glycol monoethyl (or butyl) ether, ethylene glycol dimethyl Polyether solvents such as ether (monoglyme), diethylene glycol dimethyl ether (diglyme), or triethylene glycol dimethyl ether (triglyme), dimethylformamide, dimethylacetamide, 2-pyrrolidone, N-methyl-2-pyrrolidone, 1,3-dimethyl- Amide solvents such as 2-imidazolidinone, urea or tetramethylurea, sulfur-containing solvents such as sulfolane, dimethyl sulfoxide or 3-sulfolene, polyfunctional solvents such as diacetone alcohol and diethanolamine, acetic acid and maleic acid Carboxylic acid solvents such as docosahexaenoic acid, trichloroacetic acid, or trifluoroacetic acid, and sulfonic acid solvents such as methanesulfonic acid or trifluorosulfonic acid. Two or more of these solvents may be mixed and used.

  The organic solvent is an amide solvent or a sulfur-containing solvent in the case of alkali, preferably a carboxylic acid solvent, a sulfur solvent or a sulfonic acid solvent in the case of acid, and a sulfur-containing solvent in the case of alkali. In the case of acidity, a sulfonic acid solvent is more preferable. In the case of alkaline, it is dimethyl sulfoxide (DMSO), and in the case of acid, it is more preferably methanesulfonic acid.

  When a mixed solvent of water and an organic solvent is used as the aqueous medium, the mixing ratio of water and the organic solvent is a ratio that can be uniformly dissolved, and is not particularly limited. In the case of alkali, it is preferable that water / organic solvent = 0.05 to 10 (mass ratio). When an inorganic acid is used in the acidic case, it is preferable to use sulfuric acid alone, for example, without using an organic solvent. When an organic acid is used, the organic acid itself is an organic solvent, and a plurality of acids are mixed or water is added in order to adjust viscosity and solubility. It is preferable that water / organic solvent (organic acid) = 0.005 to 0.1 (mass ratio).

  In the present embodiment, it is preferable to put a uniformly dissolved solution into the mixing field. When the suspension is added, the particle size becomes large or the particle distribution becomes broad pigment fine particles. Moreover, the mixing field may be easily blocked. The meaning of “uniformly dissolved” is a solution in which turbidity is hardly observed when observed under visible light. In this embodiment, the solution obtained through a microfilter of 1 μm or less, or when passed through a 1 μm filter. A solution in which a solution that does not contain a substance to be filtered is uniformly dissolved is preferable.

  Moreover, in this embodiment, a dispersing agent can be added in the solution containing an organic pigment or / and the aqueous solution (aqueous medium) for changing a hydrogen ion exponent (pH). The dispersant (1) has a function of adsorbing rapidly on the surface of the deposited pigment to form fine pigment particles, and (2) preventing these particles from aggregating again.

  As such a dispersant, an anionic, cationic, amphoteric, nonionic or pigmentary low molecular or polymeric dispersant can be used. These dispersants can be used alone or in combination. The dispersant used for dispersing the pigment is described in detail on pages 29 to 46 of “Pigment dispersion stabilization and surface treatment technology / evaluation” (Chemical Information Association, issued in December 2001).

  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. Of these, N-acyl-N-alkyltaurine salts are preferred. These anionic dispersants can be used singly 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 pigment dispersant is derived from an organic pigment as a parent substance and is produced by chemically modifying the parent structure. For example, sugar-containing pigment dispersants, piperidyl-containing pigment dispersants, naphthalene or perylene-derived pigment dispersants, pigment dispersants having functional groups linked to the pigment parent structure through methylene groups, and polymer-modified pigment parents. Examples include a structure, a pigment dispersant having a sulfonic acid group, a pigment dispersant having a sulfonamide group, a pigment dispersant having an ether group, or a pigment dispersant having a carboxylic acid group, a carboxylic ester group, or a carboxamide group.

  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 Naphthalene-acrylate copolymer, vinyl naphthalene-methacrylate copolymer, vinyl naphthalene-itaconate copolymer, cellulose derivative, starch derivative and the like can be mentioned. 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.

  In order to further improve the uniform dispersibility and storage stability of the pigment, the blending amount of the dispersant is preferably in the range of 0.1 to 1000 parts by mass with respect to 100 parts by mass of the pigment. The range is more preferably in the range of from 500 parts by weight to 500 parts by weight, and still more preferably in the range of from 10 parts by weight to 250 parts by weight.

  As described above, organic pigment fine particles are precipitated by mixing and reacting the prepared solution L1 and solution L2 in a mixing field. In the present embodiment, organic pigment fine particles having a small size and excellent monodispersibility are manufactured by performing a high-pressure mixing method in which at least one of the plurality of solutions L1 and L2 is supplied to a mixing field by a high-pressure jet stream. I did it.

  Next, a method and apparatus for producing organic pigment fine particles according to the present invention will be described.

  In the method for producing organic pigment fine particles, the above-mentioned mixing performance of the two liquids is important. As the types of high-pressure mixing methods for obtaining high mixing performance, 1) one-jet mixing method, 2) T-shaped / Y-shaped mixing method, and 3) parallel flow mixing method can be suitably used. Each mixing method will be described below.

1) One-Jet Mixing Method FIG. 1 is a preferred conceptual diagram showing the structure of a static mixing device 12 that implements the one-jet mixing method.

  As shown in FIG. 1, the static mixing device 12 has an opening on one end side of a mixer 22 in which a cylindrical mixing chamber 20 (mixing field) for mixing and reacting the solution L1 and the solution L2 is formed. A first conduit 24 for introducing the solution L2 into the mixing chamber 20 is connected, and a discharge pipe 26 for the reaction solution mixed and reacted in the mixing chamber 20 is connected to the other end side opening. A second conduit 28 for introducing the solution L1 into the mixing chamber 20 is connected to the side of the mixer 22 near the outlet of the first conduit 24. A first orifice 30 is formed inside the distal end of the first conduit 24. As a result, a first nozzle 34 that ejects turbulent liquid is formed in the first conduit 24.

  In FIG. 1, the solution L2 is introduced from the first conduit 24 and the solution L1 is introduced from the second conduit 28. However, both solutions can be reversed. Further, if the connection position of the discharge pipe 26 is in the vicinity of the other end side of the mixer 22, the discharge pipe 26 may be connected to the side surface of the mixer 22.

  A jacket 21 through which a heat medium having a relatively large heat capacity such as water and oil flows is wound around the outer periphery of the mixer 22, and a heat medium inlet 23A and a heat medium outlet 23B of the jacket are not shown. It is preferably connected to a supply device.

  From the heat medium supply device, a heat medium having a temperature capable of controlling the reaction temperature with the solutions L1 and L2 in the mixer 22 in the range of −20 ° C. to 90 ° C. is supplied to the jacket 21, and again to the heat medium supply device. Circulated. The reaction temperature depends on the type of reaction of the solutions L1 and L2, but is preferably set similarly to the reaction temperature in the mixing field in the case of producing the organic pigment fine particles described above. Moreover, it is more preferable to set reaction temperature to 10-60 degreeC, and it is still more preferable to set to 25-50 degreeC.

  Further, there is a balance with the amount of the solutions L1 and L2 mixed and reacted in the mixer 22, but when it is difficult to raise the temperature to the set reaction temperature by simply winding the jacket 21, the solution L1, A temperature adjusting device may be provided in a preparation tank (not shown) for preparing L2.

  As a method of drilling the first orifice 30 in the block-shaped orifice material 23, a micro-cutting process, a micro-machining process, or a micro-machining process can be used as a method of precisely opening an ejection hole of about 100 μm in the orifice material 23 of metal, ceramics, glass or the like. Grinding, spraying, micro electrical discharge machining, LIGA method, laser machining, SPM machining, etc. can be suitably used.

  The material of the orifice material 23 is preferably a material having good workability and a hardness close to diamond. Therefore, as materials other than diamond, those obtained by hardening various metals and metal alloys such as quenching, nitriding, and sintering can be preferably used. Ceramics also have high hardness and can be suitably used because it is more workable than diamond.

  In the present embodiment, an example of an orifice will be described as the throttle structure of the first nozzle 34. However, any other method can be used as long as it has a function of ejecting turbulent liquid. .

  Further, the first conduit 24 is provided with a pressurizing means (not shown), and the solution L1 is pressurized and supplied to the first nozzle 34.

  Various means are known as pressurizing means for applying a high pressure to the liquid, and any means can be used. However, relatively easy and inexpensive means such as a plunger pump and a booster pump are available. It is preferable to use a simple reciprocating pump. Moreover, although high pressure cannot be generated as much as a reciprocating pump, there is a high pressure generating type among rotary pumps, and such a pump can also be used.

  As a material of the member constituting the static mixing device 12, a material having high strength, corrosion prevention, and high fluidity of the raw material fluid is preferable. For example, metals (iron, aluminum, stainless steel, titanium, other various metals), ceramics (silicon, etc.) can be preferably used.

  In order to further enhance the corrosion resistance of the metal material, a member in which the surface in contact with the solution is coated (lined) with resin (fluorine resin, acrylic resin, etc.) or glass (quartz etc.) can be used.

  In the present embodiment, the organic pigment fine particle precipitation reaction is substantially perpendicular to the solution L2 in the entrained flow accompanying the turbulent high-speed high-pressure jet solution L2, as schematically shown in FIG. By entraining the solution L1 flowing in from, the solution L2 and the solution L1 are mixed to obtain high-performance mixing and reaction. Accordingly, the mixing chamber 20 and the first nozzle 34 of the static mixing device 12 are formed to have the following relationship.

  That is, as shown in FIG. 1, the equivalent circle diameter D of the cross-sectional area of the mixing chamber 20 is formed larger than the equivalent circle diameter d of the sectional area of the orifice of the first nozzle 34. The equivalent circle diameter refers to the diameter of a circle corresponding to the same sectional area when the sectional shape is not a circle. In particular, the dimensional ratio D / d of the equivalent circle diameter D of the mixing chamber 20 to the equivalent circle diameter d of the orifice of the first nozzle 34 is preferably in the range of 5-30.

  The equivalent circle diameter D of the mixing chamber 20 is preferably 10 mm or less, and more preferably 1 mm to 5 mm. The equivalent circle diameter d of the orifice is preferably 0.1 mm to 1 mm.

  In addition, it is necessary to ensure the length L of the mixing chamber 20, but if it is too long, the reaction liquid LM is in a laminar flow state in the mixing chamber 20 and particle precipitation is likely to occur. Accordingly, the length L of the mixing chamber 20 is preferably 20 mm to 100 mm.

  In addition, the shape of the longitudinal section of the mixing chamber 20 or the longitudinal section of the orifice may be a rectangle, a trapezoid, a semicircle, or the like other than a circle.

  In order to obtain high-performance mixing and reaction with the solution L1 and the solution L2, the ejection pressure of the high-pressure jet stream ejected from the first nozzle 34 into the mixing chamber 20 is preferably in the range of 1 MPa to 200 MPa.

  Moreover, it is preferable that the flow velocity of the high-pressure jet flow ejected from the first nozzle 34 to the mixing chamber 20 is in the range of 50 m / sec to 700 m / sec.

  In addition, the Reynolds number Re in the vicinity of the jet outlet of the first nozzle 34 of the high-pressure jet flow jetted into the mixing chamber 20 is preferably in the range of 2100 to 150,000.

  In addition, as shown in FIG. 2, the collision angle θ between the high-pressure jet stream (solution L2 in the figure) and a solution other than the high-pressure jet stream (solution L1 in the figure) is 0 ° to 90 °. Is preferred.

  Appropriate ranges of the high-pressure jet flow and the apparatus configuration as described above are grasped by performing simulation in advance using R-Flow, a numerical analysis software made by R-Flow, which is already commercially available in Japan as a flow analysis software. be able to.

  The jet flow shape of the high-pressure jet flow jetted from the first nozzle 34 to the mixing chamber 20 is regulated by the first orifice 30 provided in the first nozzle 34, and this jet flow shape affects the mixing performance. Accordingly, it is preferable to appropriately use the first orifice 30 that forms a jet flow shape such as a filament shape, a conical shape, a slit shape, or a fan shape in accordance with the purpose of the reaction.

  For example, in the case of a reaction with a very high reaction speed on the order of milliseconds, the first orifice 30 that forms a spouted flow shape is preferable. When the reaction rate is relatively slow, the first orifice 30 that forms a thin jet flow shape is preferable. In the case of an intermediate reaction rate between a very fast reaction rate on the order of milliseconds and a relatively slow reaction rate as in this embodiment, the first orifice 30 that forms a conical jet flow shape is preferable. .

  FIGS. 3 to 6 illustrate the first orifice 30 for forming each of the spouted flow shapes, such as a filament shape, a conical shape, a slit shape, and a fan shape. Among these, (a) in each figure is the figure which looked at the orifice from the front end side, (b) is the longitudinal cross-sectional view of an orifice, (c) is the cross-sectional view of an orifice.

  FIG. 3 shows a first orifice 30 for ejecting the straight linear flow A in the mixing chamber 20 and is formed in a linear shape. FIG. 4 shows a first orifice 30 for ejecting the conical straight flow A into the mixing chamber 20, and is formed in a trumpet shape with an open front end. FIG. 5 shows a first orifice 30 for ejecting a straight-line flow A of a thin film into the mixing chamber 20 and is formed in a rectangular slit shape. FIG. 6 shows a first orifice 30 for ejecting a straight flow A of a fan-shaped thin film into the mixing chamber 20, and the tip portion is formed with a fan-shaped diameter.

  Next, the operation of the static mixing device 12 will be described with reference to FIG.

  First, as shown in FIG. 2, a liquid (solution L2) that does not dissolve the pigment is ejected from the first nozzle 34 as a high-pressure jet flow (arrow A), and a turbulent flow is formed in the mixing chamber 20. Further, the organic pigment solution (solution L1) is supplied from the second conduit 28 to the mixing chamber 20 as an orthogonal flow that is substantially orthogonal to the solution L2 (arrow B).

  In this case, even if the solution L2 is not completely orthogonal to the solution L1 at an angle of 90 °, the solution L2 only needs to have an orthogonal velocity vector component as a main component. Alternatively, the solution L2 may be injected from the first nozzle 34 into the mixing chamber 20 as a high-pressure jet flow, and the solution L1 may be supplied into the mixing chamber 20 from the second conduit 28. Moreover, it is preferable to control the reaction temperature in the mixer 22 in the range of 5 ° C. to 80 ° C. by the temperature adjusting device of the preparation tank for preparing the jacket 21 and / or the solutions L1 and L2 wound around the mixer 22. .

  Thereby, the solution L1 and the solution L2 are instantaneously and efficiently mixed and reacted under appropriate temperature conditions to precipitate organic pigment fine particles, and a reaction liquid LM (organic pigment fine particle dispersion) containing organic pigment fine particles. Is generated. Then, the reaction liquid LM is immediately discharged from the discharge pipe 26.

  Thereby, the organic pigment fine particles excellent in monodispersity satisfying the particle size distribution Mv / Mn of 1.55 or less can be produced.

  Next, a modification of the static mixing device 12 of FIG. 1 will be described. 7 and 8 are conceptual diagrams showing structures of modified examples of the static mixing device 12 of FIG. In each figure, the description of the jacket 21 is omitted.

  The static mixing device 12 in FIG. 7 is configured in the same manner as in FIG. 1 except that the vicinity of the outlet of the first conduit 24 in the mixing chamber 20 is a trumpet tube having a tip opened in the discharge direction, that is, a streamlined shape. ing.

  By setting it as such a shape, retention of the solutions L1 and L2 can be suppressed.

  The static mixing device 12 shown in FIG. 8 has a trumpet-shaped or streamlined shape in which the vicinity of the outlet of the first conduit 24 in the mixing chamber 20 is open toward the outlet, and the number of conduits for supplying a solution other than the high-pressure jet flow. The configuration is the same as that shown in FIG.

  Thereby, while restraining retention of the solutions L1 and L2, the mixing performance and reaction efficiency of a high-pressure jet stream and other solutions can be improved.

  In addition, in FIG. 1, FIG. 7 and FIG. 8, when there are two or more kinds of solutions to be mixed, a plurality of conduits for introducing the solution may be further installed.

  Note that the static mixing device 12 that performs the one-jet mixing method is not limited to the above-described FIG. 1, FIG. 7, and FIG. 8, and the solution L1 and the solution L2 are larger than the nozzle diameter from each nozzle. A static mixing device that ejects the reaction liquid to a mixing field having a diameter and causes the reaction liquid to discharge from a discharge port having a diameter smaller than the diameter of the mixing field is used, and at least one solution of the solution L1 and the solution L2 is 1 MPa to 200 MPa. Any high-pressure jet stream and any Reynolds number Re when flowing into the mixing field can be jetted to the mixing field in the range of 2100 to 150,000 and the remaining solution can be supplied at a lower pressure than the high-pressure jet stream. .

  In the present embodiment, the example of the one-jet method in which the high-pressure jet flow is formed by the first orifice 30 has been described, but the solution L2 other than the high-pressure jet flow may be ejected from the second orifice to be a two-jet method. Further, a three-jet method, a multi-jet method, or the like that forms three or more high-pressure jet flows may be used.

2) T-shaped / Y-shaped mixing method FIGS. 9 and 10 are conceptual diagrams showing the structure of a preferred embodiment of a static mixing device 40 that performs the T-shaped / Y-shaped mixing method. 9 shows a T-shaped static mixing device 40, and FIG. 10 shows a Y-shaped static mixing device 40.

  As shown in FIGS. 9 and 10, the high-pressure jet satisfying the above-described range of the jetting pressure of the solution L1 and the solution L2 at the intersection (mixing field) of very thin pipes such as a T-shaped pipe and a Y-shaped pipe. By colliding with the flow, both liquids are instantaneously mixed and reacted, and the reaction liquid LM is discharged from the discharge pipe in a short time.

  That is, the solution L2 is ejected from the second addition pipe 46 to the mixing field 44 with a high-pressure jet flow that satisfies the above-described jet pressure range, and the solution L1 is filled from the first addition pipe 42 to the above-described jet pressure range. Both solutions are made to collide by jetting into the mixing field 44 with a high-pressure jet stream. The reaction liquid LM mixed and reacted with the energy by the collision is discharged from the discharge pipe 48 in a short time.

  Note that the pressures of the solution L1 and the solution L2 may be the same or different as long as they are within the range of the ejection pressure described above. Further, a jacket 43 is wound around the outer periphery of the first addition pipe 42, the second addition pipe 46, and the discharge pipe 48, and, as described with reference to FIG. The reaction temperature is controlled. Also in this case, a temperature adjusting device can be provided in a preparation tank (not shown) for preparing the solutions L1 and L2. 9 and 10, reference numeral 43 </ b> A is a heat medium inlet of the jacket 43, and reference numeral 43 </ b> B is a heat medium outlet. As a result, the solution L1 and the solution L2 are instantaneously and efficiently mixed and reacted under an appropriate reaction temperature condition to form a reaction liquid LM containing organic pigment fine particles.

  As a result, organic pigment fine particles having excellent monodispersity that satisfy the particle size distribution Mv / Mn of the organic pigment fine particles of 1.55 or less can be produced.

  FIG. 11 shows a mixing chamber 20 (mixing field) that is a high-pressure jet flow that satisfies the range of the above-described ejection pressure from the direction in which the solution L1 and the solution L2 face each other, and is larger than the diameter of the nozzle that ejects the L1 solution and the L2 solution The reaction liquid LM is discharged from a discharge pipe 26 having a diameter smaller than the diameter of the mixing chamber 20. The same members and phenomena as those in FIGS. 1 and 2 are described with the same reference numerals.

  The static mixing apparatus 10 of FIG. 11 introduces the solution L1 into the mixing field 20 into an opening on one end side of a mixer 22 in which a cylindrical mixing chamber 20 for mixing and reacting the solution L1 and the solution L2 is formed. The first conduit 24 is connected, and the second conduit 28 for introducing the solution L2 into the mixing chamber 20 is connected to the opening on the other end side. Further, a discharge pipe 26 for discharging the reaction liquid LM mixed and reacted in the mixing chamber 20 from the mixing chamber 20 is connected to the central opening of the mixer 22.

  A first orifice 30 and a second orifice 32 are provided inside the distal ends of the first conduit 24 and the second conduit 28, respectively, so that the first conduit 24 and the second conduit 28 are not disturbed. A first nozzle 34 and a second nozzle 36 for injecting the straight flow A1, A2 of the flow are formed. In the present embodiment, the example in which the solution L1 is ejected from the first nozzle 34 and the solution L2 is ejected from the second nozzle 36 will be described.

  A jacket 21 is wound around the outer periphery of the mixer 22, and the reaction temperature with the solutions L <b> 1 and L <b> 2 in the mixer 22 is controlled as described with reference to FIG. 1. Also in this case, a temperature adjusting device can be provided in a preparation tank (not shown) for preparing the solutions L1 and L2.

  The equivalent circle diameter D of the mixing chamber 20, the equivalent circle diameter d1 of the orifice of the first nozzle 34, and their dimensional relationship may be different from those in the one-jet mixing method. Further, the orifice diameter d2 of the second nozzle 36 may be different from the orifice diameter of the first nozzle 34. The length L of the mixing chamber 20 is the same as in the case of the one jet. Further, the method of forming the first and second orifices 30 and 32, the material of the orifice material 23, and the pressurizing means are the same as described in the one-jet mixing method. Further, the shapes of the straight flow A1 and A2 can be formed into the shape of each of the spouted flow shapes such as a thread line shape, a conical shape, a slit shape, and a fan shape.

  11 and FIG. 12, the solution L1 and the solution L2 are ejected from the first nozzle 34 and the second nozzle 36 from one end and the other end of the mixing chamber 20 by a high-pressure jet flow, and are opposed to each other. Collisions are made in the mixing chamber 20 as A1 and A2. The solution L1 and the solution L2 are reacted instantaneously under appropriate reaction temperature conditions by the two straight flow A1 and A2, thereby forming a reaction liquid LM containing organic pigment fine particles. Thereby, the organic pigment fine particles excellent in monodispersity satisfying the particle size distribution Mv / Mn of 1.55 or less can be produced.

  As described above, not only the contact efficiency at the liquid-liquid interface between the straight flow A1 and the straight flow A2 is increased to improve the mixing performance, but also heat generation due to liquid-liquid friction caused by the collision between the straight flow A1 and the straight flow A2. Can also be suppressed.

The static mixing devices 10 and 40 that perform the T-shaped / Y-shaped mixing method are not limited to those shown in FIGS. 9 to 12 described above, and all of the solution L1 and the solution L2 in the mixing field. As long as the jet pressure can be made to collide with a high-pressure jet flow satisfying the above-mentioned range.
3) Parallel Flow Mixing Method FIG. 13 is a cross-sectional view showing the structure of a preferred embodiment of a static mixing device 50 that implements the parallel flow mixing method.

  As shown in FIG. 13, the static mixing device 50 is formed of a concentric double cylindrical tube structure with an inner tube 52 and an outer tube 54. As a result, a narrow inner flow path 56 is formed in the inner pipe 52, and an annular narrow annular outer flow path 58 is formed between the inner pipe 52 and the outer pipe 54. Further, the outlet 52A of the inner tube 52 is retracted somewhat deeper than the outlet 54A of the outer tube 54, and a mixing field 60 is formed in the space formed thereby. Further, the first supply pipe 62 is connected to the inlet 56 </ b> A of the inner flow path 56, and the second supply pipe 64 is connected to the inlet 58 </ b> A of the annular outer flow path 58.

  A jacket 51 is wound around the outer circumference of the outer tube 54, and the reaction temperature with the solutions L1 and L2 in the mixing field 60 is controlled in the same manner as described with reference to FIG. Also in this case, a temperature adjusting device can be provided in a preparation tank (not shown) for preparing the solutions L1 and L2. In addition, the code | symbol 51A of FIG. 11 is a heat-medium inlet of the jacket 51, and the code | symbol 51B is a heat-medium exit.

  Then, the solution L2 is introduced from the first supply pipe 62, the solution L1 is introduced from the second supply pipe 64, and the Reynolds number Re when the solution L1 and the solution L2 flow into the mixing field 60 is in the above range. To satisfy. Thereby, in the mixing field 60, the solution L1 and the solution L2 are instantaneously and efficiently mixed and reacted under an appropriate reaction temperature condition to form a reaction liquid LM containing organic pigment fine particles, and the reaction liquid LM is mixed. It is immediately discharged from the exit 66 of the field 60.

  The supply pipes for the solution L1 and the solution L2 may be reversed. Thereby, the organic pigment fine particles excellent in monodispersity satisfying the particle size distribution Mv / Mn of 1.55 or less can be produced.

  The static mixing device 50 that performs the parallel flow mixing method is not limited to the double cylindrical tube structure. For example, when a plurality of solutions are mixed with the solution L2, a number of multiples corresponding to the number of solutions is used. A cylindrical tube structure is preferable.

  FIG. 14 shows a yarn-like jet flow shape in which one of the solution L1 and the solution L2 passes from the inner tube 52 to the mixing field and the Reynolds number Re satisfies the above range, and the other solution passes from the outer tube 54 to the mixing field. Re is in the shape of an annular jet flow satisfying the above-mentioned range, and is jetted into a mixing chamber (mixing field) larger than the nozzle diameter for jetting these solutions, and the reaction liquid LM is smaller in diameter than the diameter of the mixing field. The gas is discharged from the discharge pipe 26. The same members as those in FIG. 13 are denoted by the same reference numerals and description thereof is omitted, and the same members as those shown in FIG.

  The static mixing device 70 of FIG. 14 has a cylindrical mixing chamber 20 (mixing field) having a diameter larger than the diameter of the outer tube 54 connected to the tip of the outer tube 54 shown in FIG. A discharge pipe 26 having a diameter smaller than that of the mixing chamber 20 is provided at the tip of the chamber 20. A jacket 53 is wound around the outer circumference of the outer tube 54 and the mixing chamber 20, and the reaction temperature with the solutions L1 and L2 in the outer tube 54 and the mixer 22 is controlled in the same manner as described with reference to FIG. . Also in this case, a temperature adjusting device can be provided in a preparation tank (not shown) for preparing the solutions L1 and L2. 14 is a heat medium inlet of the jacket 53, and 53B is a heat medium outlet.

  Then, the solution L1 is introduced from the first supply pipe 62, the solution L2 is introduced from the second supply pipe 64, and the Reynolds number Re when the solution L1 and the solution L2 flow into the mixing field 60 is Fill the range. The supply pipes for the solution L1 and the solution L2 may be reversed.

  Accordingly, the solution L1 and the solution L2 react instantaneously and efficiently under appropriate reaction temperature conditions to form a reaction liquid containing organic pigment fine particles, and the reaction liquid LM is immediately discharged from the discharge pipe 26.

  In this way, one solution is ejected into the mixing chamber 20 in an annular shape, and the other solution is ejected in the form of a filament at the center of the annular shape, thereby instantly and efficiently mixing the solution L1 and the solution L2. Then, a reaction solution containing organic pigment fine particles is formed. Thereby, the organic pigment fine particles excellent in monodispersity satisfying the particle size distribution Mv / Mn of 1.55 or less can be produced.

  In FIGS. 13 and 14, the cylinder diameter D (inner diameter of the outer tube) of the mixing chambers 20 and 60, the inner diameter d of the inner tube, and their dimensional relationship are the relationship between the cylinder diameter D and the orifice d1 in the case of the one-jet mixing method. Same as relationship. The lengths of the mixing chambers 20 and 60 are the same as in the one-jet mixing method. Further, the method of forming the first and second orifices 30 and 32 and the material of the orifice material 23 are the same as described in the one-jet mixing method.

  Further, the static mixing devices 50 and 70 for performing the parallel flow mixing method are not limited to those shown in FIG. 13 and FIG. 14 described above, and are mixed and reacted, and the reaction liquid is discharged from the mixing field. Any solution can be used as long as the Reynolds number Re when the solution flows into the mixing field can satisfy the above range.

  As mentioned above, although each embodiment of the manufacturing method of the organic pigment fine particle which concerns on this invention was described, this invention is not limited to the said embodiment, Various aspects can be taken.

  For example, the temperature control in the mixing field may be controlled by putting the entire apparatus having the mixing field in a temperature-controlled container, or a heater structure such as a metal resistance wire or polysilicon is built in the apparatus. This may be used for heating and thermal cooling may be performed by natural cooling for cooling.

  Next, a pigment ink composition will be described as an application example using the organic pigment fine particles according to the present invention.

  An ink composition, for example, an ink composition for ink jet recording, can be prepared by dissolving and / or dispersing organic pigment fine particles produced by applying the present invention in an oleophilic medium or an aqueous medium. In particular, it is preferable to use an aqueous medium. Moreover, it is preferable to contain another additive as needed.

  The water-soluble organic solvent is used for the purpose of preventing drying, accelerating wetting and adjusting the viscosity. Further, the drying inhibitor is suitably used at the ink ejection port of the nozzle in the ink jet recording method, and prevents clogging due to drying of the ink for ink jet.

  Specific examples of the water-soluble organic solvent include alcohols (for example, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, sec-butanol, t-butanol, pentanol, hexanol, cyclohexanol, benzyl alcohol), many Monohydric alcohols (eg, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, hexanediol, pentanediol, glycerin, hexanetriol, thiodiglycol), glycol derivatives ( For example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono Chill ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, triethylene glycol monomethyl ether, ethylene glycol diacetate, ethylene glycol monomethyl ether acetate, triethylene glycol monomethyl ether , Triethylene glycol monoethyl ether, ethylene glycol monophenyl ether), amine (for example, ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethyleneto Amines, triethylenetetramine, polyethyleneimine, tetramethylpropylenediamine) and other polar solvents (eg, formamide, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, sulfolane, 2-pyrrolidone, N-methyl) 2-pyrrolidone, N-vinyl-2-pyrrolidone, 2-oxazolidone, 1,3-dimethyl-2-imidazolidinone, acetonitrile, acetone). In addition, a water-soluble organic solvent may be used independently and may use 2 or more types together.

  Other additives include, for example, anti-drying agents (wetting agents), anti-fading agents, emulsion stabilizers, penetration enhancers, ultraviolet absorbers, preservatives, anti-fungal agents, pH adjusters, surface tension adjusters, Well-known additives, such as a foaming agent, a viscosity modifier, a dispersing agent, a dispersion stabilizer, a rust preventive agent, a chelating agent, are mentioned. In the case of water-soluble ink, these various additives are added directly to the ink.

  Polymer fine particles may be added to the ink mainly for the purpose of improving the fixing property of the ink to the recording medium and the abrasion resistance of the coated surface. Such polymer fine particles are preferably dispersed in water and a water-containing organic solvent as a polymer latex.

  As the polymer latex, various latexes such as styrene latex, acrylic latex and vinyl acetate latex can be used, and styrene latex is particularly preferable. The styrene-based latex is preferably a styrene-butadiene copolymer or a styrene-isoprene copolymer latex, and more preferably a styrene-butadiene copolymer coated on art paper or coated paper.

  The polymer latex may be a copolymer of monomers other than styrene and butadiene, and any copolymerizable monomer may be used. As such a polymer latex, acrylic acid, methacrylic acid, acrylic acid ester, methacrylic acid ester, and acrylamide 2-methylpropanesulfonic acid are preferable, and acrylic acid, methacrylic acid, and acrylamide 2-methylpropanesulfonic acid are preferable. More preferred are acrylic acid and methacrylic acid. The addition amount of the polymer fine particles is preferably 0.5 to 20% by mass and more preferably 1 to 20% by mass with respect to the ink.

  The drying inhibitor is preferably a water-soluble organic solvent having a vapor pressure lower than that of water. Specific examples of the drying inhibitor include ethylene glycol, propylene glycol, diethylene glycol, polyethylene glycol, thiodiglycol, dithiodiglycol, 2-methyl-1,3-propanediol, 1,2,6-hexanetriol, Polyvalent alcohols typified by acetylene glycol derivatives, glycerin, trimethylolpropane, etc., polyvalent alcohols such as ethylene glycol monomethyl (or ethyl) ether, diethylene glycol monomethyl (or ethyl) ether, triethylene glycol monoethyl (or butyl) ether Lower alkyl ethers of alcohols, 2-pyrrolidone, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, heterocyclic rings such as N-ethylmorpholine, sulfolane, dimethyls Sulfoxide, sulfur-containing compounds such as 3-sulfolene, diacetone alcohol, polyfunctional compounds such as diethanolamine, and urea derivatives. Of these, the drying inhibitor is preferably a polyhydric alcohol such as glycerin or diethylene glycol. Moreover, said drying inhibitor may be used independently or may be used together 2 or more types. These drying inhibitors are preferably contained in the ink in an amount of 10 to 50% by mass.

  The penetration accelerator is preferably used for the purpose of allowing the ink to penetrate better into the recording medium (printing paper). Specific examples of penetration enhancers include alcohols such as ethanol, isopropanol, butanol, di (tri) ethylene glycol monobutyl ether, 1,2-hexanediol, sodium lauryl sulfate, sodium oleate, and nonionic surfactants. Etc. can be used suitably. These penetration enhancers exhibit a sufficient effect when contained in the ink composition in an amount of 5 to 30% by mass. Further, it is preferable that the penetration enhancer is used within a range of an addition amount that does not cause printing bleeding and paper loss (print through).

  As the dispersant, the aforementioned dispersants can be used.

  The ultraviolet absorber is used for the purpose of improving image storability. Examples of ultraviolet absorbers include benzotriazoles described in JP-A Nos. 58-185677, 61-190537, JP-A-2-782, JP-A-5-97075, JP-A-9-34057, and the like. Compounds, benzophenone compounds described in JP-A No. 46-2784, JP-A No. 5-194433, US Pat. No. 3,214,463, etc., JP-B Nos. 48-30492, 56-211141, Cinnamic acid compounds described in, for example, Kaihei 10-88106, JP-A-4-298503, 8-53427, 8-239368, 10-182621, JP-A-8- No. 501291, etc., triazine compounds, Research Disclosure No. The compounds described in No. 24239, compounds that emit fluorescence by absorbing ultraviolet rays typified by stilbene-based compounds and benzoxazole-based compounds, so-called fluorescent brighteners, can also be used.

  The anti-fading agent is used for the purpose of improving image storage stability. As the anti-fading agent, various organic and metal complex anti-fading agents can be used. Organic anti-fading agents include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, heterocycles, etc. Complex, zinc complex and the like. More specifically, Research Disclosure No. No. 17643, Nos. VII to I, J; 15162, ibid. No. 18716, page 650, left column, ibid. No. 36544, page 527, ibid. No. 307105, page 872, ibid. The compounds described in the patent cited in Japanese Patent No. 15162 and the compounds included in the general formulas and compound examples of typical compounds described on pages 127 to 137 of JP-A-62-215272 can be used.

  Examples of the antifungal agent include sodium dehydroacetate, sodium benzoate, sodium pyridinethione-1-oxide, p-hydroxybenzoic acid ethyl ester, 1,2-benzisothiazolin-3-one and salts thereof. These are preferably used in an amount of 0.02 to 1.00% by weight in the ink.

  As the pH adjuster, a neutralizer (organic base, inorganic alkali) can be used. For the purpose of improving the storage stability of the inkjet ink, the pH adjuster is preferably added so that the inkjet ink has a pH of 6 to 10, and more preferably added to have a pH of 7 to 10.

  Examples of the surface tension adjusting agent include nonionic surfactants, cationic surfactants, anionic surfactants, betaine surfactants, and the like.

  The addition amount of the surface tension adjusting agent is preferably an addition amount that adjusts the surface tension of the ink to 20 mN / m to 60 mN / m, and is preferably adjusted to 20 mN / m to 45 mN / m, in order to eject droplets well by inkjet. The amount is more preferable, and the addition amount adjusted to 25 mN / m to 40 mN / m is more preferable.

  Specific examples of surfactants include fatty acid salts, alkyl sulfate esters, alkylbenzene sulfonates, alkyl naphthalene sulfonates, dialkyl sulfosuccinates, alkyl phosphate esters, naphthalene sulfonate formalin condensation in hydrocarbons Products, anionic surfactants such as polyoxyethylene alkyl sulfates, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxy Nonionic surfactants such as ethylene alkylamine, glycerin fatty acid ester and oxyethyleneoxypropylene block copolymer are preferred. Further, SURFYNOLS (Air Products & Chemicals), which is an acetylene-based polyoxyethylene oxide surfactant, is also preferably used. An amine oxide type amphoteric surfactant such as N, N-dimethyl-N-alkylamine oxide is also preferred.

  The above surface tension adjusting agent can also be used as an antifoaming agent, and fluorine compounds, silicone compounds, chelating agents represented by EDTA, and the like can also be used.

  As described above, the pigment ink has been described as an application example to which the present invention is applied. However, the present invention is not limited to the above, and the present invention is not limited to the above. Applicable.

  Next, examples will be described in detail, but the present invention is not limited to the following examples. Using a static mixing device 12 shown in FIG. 1, a solution L1 in which an organic pigment, a dispersant, and the like are dissolved and an aqueous solvent L2 are mixed to produce organic pigment fine particles by a build-up method.

(Preparation of raw material solution)
Dimethyl sulfoxide (DMSO) and caustic potash are mixed, dimethyl quinacridone pigment is added and stirred while stirring at room temperature, impurities are removed with a 0.45 μm filter, and 1% by weight dimethyl quinacridone solution (solution L1) Was prepared.

  Distilled water was used as Solution L2. The density of the solution L1 was 1.1 g / mL, and the density of the solution L2 was 1.0 g / mL.

(Production conditions for organic pigment fine particles)
In the static mixing device 12 shown in FIG. 1, a solution L2 is supplied from a diamond orifice having an equivalent circle diameter d of 0.2 mm to a mixing chamber 20 having an equivalent circle diameter D of 4 mm and a length L of 90 mm. Was ejected at a pressure of 10 MPa (Example 1). The solution L2 became a yarn-like high-pressure jet flow in the mixing chamber 20, and formed a turbulent vortex. The solution L2 whose temperature was adjusted to 25 ° C. was jetted into the mixing chamber 20. The flow rate of the high-pressure jet stream of this solution L2 was 141 m / s, and the Re number was 2.8 × 10 ⁴ .

  Next, as a result of supplying the solution L1 from the second conduit 28 so that the flow rate of the solution L1 is about 1/6 of the solution L2, the solution L2 that forms a string-like high-pressure jet flow in the mixing chamber 20 Upon mixing, organic pigment fine particles were precipitated. The temperature of the solution L1 was adjusted to 25 ° C. as in the case of the solution L2. The reaction liquid containing the organic pigment fine particles was collected from the discharge pipe 26. The flow rate of the reaction liquid at this time was 230 mL / min. This corresponds to the fact that 20 g / hour of organic pigment fine particles can be produced.

  As a result of measuring the particle size distribution of the reaction liquid containing the collected organic pigment fine particles with a Microtrack particle size distribution measuring apparatus manufactured by Nikkiso Co., Ltd., as shown in FIG. The average particle diameter of the organic pigment fine particles was about 20 nm.

  On the other hand, as Comparative Example 1, the organic pigment solution L1 and the solution L2, which is distilled water, were fed at a feeding rate of 20 μL / min. In the mixing field 20, the solutions L1 and L2 both formed a laminar flow, and a reaction liquid containing organic pigment fine particles was obtained. However, as time passed, the particles accumulated in the apparatus, leading to clogging. From this, it was confirmed that Example 1 to which the present invention was applied was superior in production suitability and had a fine particle size.

  Further, as Comparative Example 2, solutions L1 and L2 were stirred and mixed in a beaker at 400 rpm to prepare a solution containing organic pigment particles. And as a result of measuring a particle size distribution like the above, as shown in FIG.15 (b), Mv / Mn was 1.59 and the average particle diameter was about 30 nm.

  As described above, by applying the method for producing organic pigment fine particles according to the present invention, organic pigment fine particles having a fine size and excellent monodispersity with a particle size distribution Mv / Mn close to 1 can be stably obtained. did it.

It is the conceptual diagram which showed the structure of the static mixing apparatus which enforces the one jet mixing method which is one Embodiment of this invention. It is explanatory drawing explaining the effect | action which mixes the solution L1 and the solution L2 in the one jet mixing method. It is explanatory drawing explaining the shape of a thread-like jet stream. It is explanatory drawing explaining a cone-shaped ejection flow shape. It is explanatory drawing explaining a slit-shaped ejection flow shape. It is explanatory drawing explaining a fan-shaped ejection flow shape. It is the conceptual diagram which showed the structure of another aspect of the static mixing apparatus which implements the one jet mixing method. It is the conceptual diagram which showed the structure of another aspect of the static mixing apparatus which implements the one jet mixing method. It is the conceptual diagram which showed the structure of the one aspect | mode of the static mixing apparatus which implements a T-shaped mixing method. It is the conceptual diagram which showed the structure of the one aspect | mode of the static mixing apparatus which implements a Y-shaped mixing method. It is the conceptual diagram which showed the structure of the one aspect | mode of the static mixing apparatus which added the concept of eddy viscosity to the T-shaped mixing method. It is explanatory drawing explaining the effect | action which mixes the solution L1 and the solution L2 in a T-shaped mixing method. It is the conceptual diagram which showed the structure of the one aspect | mode of the static mixing apparatus which implements a parallel flow mixing method. It is the conceptual diagram which showed the structure of the one aspect | mode of the static mixing apparatus in the parallel flow mixing method. It is a graph in an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 12, 40, 50, 70 ... Static mixing apparatus, 20 ... Mixing chamber (mixing field), 22 ... Mixer, 23, 43, 51, 53 ... Jacket, 24 ... First conduit, 26 ... Discharge pipe 28 ... second conduit, 30 ... first orifice, 34 ... first nozzle, 36 ... second nozzle, A ... straight flow, B ... cross flow, 42 ... first addition pipe, 44 ... intersection (mixing) ), 46 ... second addition pipe, 48 ... discharge pipe, 52 ... inner pipe, 54 ... outer pipe, 56 ... inner flow path, 58 ... annular outer flow path, 60 ... mixing field

Claims (12)

  A method for producing organic pigment fine particles, wherein a plurality of types of solutions are reacted in a mixing field by a liquid phase method, and at least one of the plurality of types of solutions is supplied into the mixing field by a high-pressure jet flow.   The method for producing fine organic pigment particles according to claim 1, wherein the reaction is a precipitation reaction.   3. The method for producing organic pigment fine particles according to claim 2, wherein the precipitation reaction is a precipitation reaction due to a change in solubility and / or a change in pH.   The method for producing organic pigment fine particles according to any one of claims 1 to 3, wherein an ejection pressure of the high-pressure jet flow supplied into the mixing field is 1 MPa to 200 MPa.   The method for producing organic pigment fine particles according to any one of claims 1 to 4, wherein a flow rate of the high-pressure jet stream supplied into the mixing field is 50 m / sec to 700 m / sec.   6. The method for producing fine organic pigment particles according to claim 1, wherein a Reynolds number Re in the vicinity of a jet outlet of the high-pressure jet stream supplied into the mixing field is 2100 to 150,000.   The ratio D / d between the equivalent circle diameter d of the outlet of the high-pressure jet flow supplied into the mixing field and the equivalent circle diameter D of the mixing field is 5-30. The manufacturing method of organic pigment fine particles in any one of -6.   The method for producing fine organic pigment particles according to any one of claims 1 to 7, wherein the collision angle between at least one high-pressure jet stream and a solution other than the high-pressure jet stream is 0 ° to 90 °.   The method for producing fine organic pigment particles according to claim 1, wherein one of the plurality of solutions is a high-pressure jet stream.   Organic pigment fine particles produced using the method for producing organic pigment fine particles according to any one of claims 1 to 9.   The organic pigment fine particles according to claim 10, wherein the particle size distribution Mv / Mn of the organic pigment fine particles is 1.55 or less.   A pigment ink comprising the organic pigment fine particles according to claim 10.

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