JP2005307154A - Organic pigment fine particle and its preparation process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a novel preparation process of a fine particle of an organic pigment which solves problems of the conventional build-up process and to provide an organic pigment particle having a uniform particle size, and a dispersion containing it by this process. <P>SOLUTION: This preparation process of an organic pigment fine particle includes a process in which a solution of an organic pigment dissolved in an alkali or acidic aqueous medium is flown in a flow passage (channel) as a laminar flow and the hydrogen ion exponent (pH) of the solution is changed in the laminar flow process. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing organic pigment fine particles. More specifically, it is a production method characterized by changing the hydrogen ion index (pH) of an organic pigment solution that flows as a laminar flow in a channel, and contains an organic pigment obtained by the method and the same Concerning the dispersion.

  Pigments exhibit vivid color tone and high coloring power, and are widely used in many fields. For example, paints, printing inks, electrophotographic toners, ink-jet inks, color filters, and the like can be cited as applications, and now they are important compounds indispensable in daily life. The general properties of pigments and the classification by use are described in Non-Patent Document 1, for example. Among the above-mentioned uses, high performance is required, and particularly important in practical use include pigments for inkjet inks and pigments for color filters.

  Dyes have been used as coloring materials for ink-jet inks, but there are drawbacks in terms of water resistance and light resistance, and pigments have been used to improve them. The image obtained with the pigment ink has a remarkable advantage in that it is excellent in light resistance and water resistance as compared with the image obtained by the dye-based ink. However, it has been difficult to uniformly refine (ie, monodisperse) a nanometer size that can penetrate into the voids on the paper surface, resulting in poor adhesion to paper.

  With the increase in the number of pixels in a digital camera, it is desired to reduce the thickness of a color filter used for a CCD sensor. An organic pigment is used for the color filter. However, since the thickness of the filter greatly depends on the particle diameter of the organic pigment, production of monodispersed and stable fine particles at a nanometer size level has been desired.

  In general, the method for producing fine particles is roughly divided into a breakdown method for producing from a bulk material by pulverization or the like, as shown in Non-Patent Document 2, etc., and a build-up method for producing by particle growth from the gas phase or liquid phase. ing. Conventionally, the pulverization method that is frequently used is a fine particle production method that is highly practical. However, in order to produce nanometer-sized particles of organic substances, the productivity is extremely low and applicable substances are limited. There are various problems, and in recent years, it has been examined whether nano-sized organic substances can be made into fine particles by the build-up method.

  As one of the methods disclosed recently, there is a method of atomizing an azo pigment, which is one of organic pigments, using a supercritical fluid or a subcritical fluid (for example, Patent Document 1). That is, it is a method for producing fine particles by dissolving a pigment in a supercritical fluid or a subcritical fluid and returning it to room temperature and normal pressure to grow crystals. In order to carry out this method, there is a problem that an apparatus capable of realizing an extremely high temperature and pressure in the vicinity of the supercritical temperature and pressure is necessary, and that organic compounds are generally easily decomposed under such conditions.

As a second method, there is a method of microparticulation using a microjet reactor which is one of microchemical process techniques (described later) (for example, Patent Documents 2, 3, and 4). In this method, the solution in which the pigment is dissolved and the precipitation medium liquid are pumped into two nozzles of different micrometer sizes facing each other at high pressure (for example, 5 MPa). In this method, air is introduced vertically, and the pigment suspension is discharged with the gas flow (about 0.5 m ³ / h). Among these, the methods described in Patent Documents 2 and 4 correspond to a breakdown method in which pigment particles are made fine by colliding pigment suspensions in a chamber. On the other hand, the method described in Patent Document 3 is to produce fine particles by spraying a pigment solution and a precipitation medium into a chamber to cause precipitation, and it is appropriate to consider the method as a build-up method. This method is devised to generate particles in a micrometer-scale small space and immediately take it out of the device to prevent clogging of the device with pigment fine particles, which is preferable for obtaining fine particles with a narrow particle size distribution. However, it is difficult to control the contact time between the two liquids, which makes it difficult to control the reaction delicately.

  A third method is a method in which a solution in which an organic pigment is dissolved is gradually brought into contact with an aqueous medium to precipitate the pigment (so-called coprecipitation method (reprecipitation method)). There is a method for producing fine particles (Patent Document 5). With this method, nanometer-sized particles can be easily produced, but when the scale is scaled up, the particle size varies, and needle-shaped particles are easily generated. However, when the particle shape was observed with a transmission electron microscope, it was a needle-like particle having a considerably long length, and it was unsuitable as a fine particle for an inkjet ink having a spherical shape.

  In addition, there is a method called conditioning that heats coarse particles to adjust the particle size as a method that is intermediate between the build-up method and breakdown method. Recently, a micro method using the idea of micro chemical process technology (described later). A method for conditioning an organic pigment in a reactor is disclosed (Patent Document 6). By continuously introducing a suspension of liquid pigment precursor (a pigment with a wide particle size distribution in a solution) into a microreactor and heat-treating, the phase change of the pigment crystal particles in the suspension At the same time, the average particle size is larger than that of the precursor, but particles having a narrow particle size distribution can be produced. Although this method has an advantage that particles having a narrow particle size distribution can be obtained, there is a disadvantage that the particle size of a small particle size in the precursor is increased.

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

  A general method for producing a disazo condensation pigment is described in, for example, Non-Patent Document 3 described above. On the other hand, as a method for producing a pigment in a microreactor based on a microchemical process technique, methods for producing a disazo condensation pigment and a diketopyrrolopyrrole pigment are disclosed in, for example, Patent Documents 7 and 8. . These can be considered as a kind of build-up method. In the description of Patent Document 7, the process leading to disazo pigment synthesis is performed in a microreactor, but since the raw material compound itself has low solubility, it is introduced into the microreactor as a suspension. If the condition control is mistaken, there is a high possibility of blocking the route, and it must be said that there is difficulty from the viewpoint of reproducibility and continuous production.

JP 2002-138216 A JP 2002-146222 A JP 2002-155221 A JP 2002-161218 A JP 2003-26972 A JP 2002-30230 A JP 2002-38043 A JP 2002-12788 A “Pigment Dispersion Stabilization and Surface Treatment Technology / Evaluation” 2001, pages 123-224, Technical Information Association. "Chemical Course of 4th Edition", Volume 12 of the Chemical Society of Japan, Year, 411-488, Maruzen Co., Ltd. W. Herbst, K. Hunger, “Industrial Organic Pigments, Production, Properties, Applications, Second Completely Revised Edition”, VCH A Wiley company, 1997, p. 595-630

  An object of this invention is to provide the organic pigment fine particle which solved the trouble of the conventional buildup method, and its manufacturing method. That is, in the synthesis of organic pigments, the object is to obtain an organic pigment simply and with high purity, and to provide a specific production method thereof. Furthermore, it aims at obtaining the pigment obtained by the above-mentioned reaction as organic pigment fine particles (monodispersed organic pigment fine particles) having a more uniform particle diameter, and providing a production method thereof.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors synthesized organic pigments by circulating a solution containing reaction components in a flow channel (channel). It was found that an organic pigment was obtained. In addition, compared with the conventional method in which a solution of organic pigment is carried out in a flask by carrying out a coprecipitation method (reprecipitation method) under the influence of pH change in a flow path where the laminar flow is dominant. It has been found that organic pigment fine particles having a more uniform particle diameter can be obtained. Furthermore, it has been found that by applying this method and selecting a synthetic intermediate, it can be produced particularly efficiently without clogging the flow path. The present invention has been made based on these findings.

（式中、ＸおよびＹは、独立してフッ素原子、塩素原子、炭素数１〜３のアルキル基、炭素数１〜３のアルコキシ基及びＣＯＯＲ_ａ基（ここでＲ_ａは、水素原子または炭素数１〜１０のアルキル基である）を表し、ｍおよびｎは、独立して０、１または２を表す。）
（１５）有機顔料微粒子が、アゾカルボン酸のアリールエステルと芳香族ジアミンの縮合体、またはアゾジカルボン酸のジアリールエステルと芳香族アミンの縮合体である、（１３）に記載の製造方法、
（１６）有機顔料を溶解した溶液および水性媒体の少なくとも一方が分散剤を有し、これら両者を、好ましくは等価直径１ｍｍ以下の流路を有する装置中で接触させて、該顔料を微粒子化することを特徴とする、顔料分散液の製造方法、
（１７）分散剤の少なくとも一つが高分子分散剤であることを特徴とする（１６）に記載の製造方法、
（１８）分散剤の少なくとも一つがアニオン性分散剤であることを特徴とする（１６）に記載の製造方法、
（１９）高分子分散剤の少なくとも一つとアニオン性分散剤の少なくとも一つとを含有する、（１６）〜（１８）のいずれか１項に記載の製造方法、
（２０）前記有機顔料の溶液がアルカリ性であることを特徴とする（１６）〜（１９）のいずれか１項に記載の製造方法、
により達成された。更に、本発明は以下の方法によっても達成された。 That is, the present invention (1) circulates a solution of an organic pigment dissolved in an alkaline or acidic aqueous medium as a laminar flow in a channel (channel), and determines the hydrogen ion index (pH) of the solution in the laminar flow process. A method for producing organic pigment fine particles having a step of changing,
(2) The method according to (1), wherein the organic pigment solution is alkaline.
(3) The method according to (1) or (2), wherein the organic pigment solution is a homogeneous solution in which the organic pigment is dissolved in a homogeneous mixed solvent of water and an organic solvent,
(4) The manufacturing method according to any one of (1) to (3), wherein the flow path has an equivalent diameter of 10 mm or less,
(5) The method according to any one of (1) to (4), wherein the organic pigment solution contains at least one dispersant.
(6) The production method according to (5), wherein at least one of the dispersants is a polymer dispersant,
(7) The production method according to (5), wherein at least one of the dispersants is an anionic dispersant,
(8) The production method according to any one of (5) to (7), comprising at least one of a polymer dispersant and at least one of an anionic dispersant,
(9) The production method according to any one of (1) to (8), wherein the organic pigment fine particles are obtained as a dispersion thereof.
(10) The manufacturing method according to any one of (1) to (9), wherein the flow path has an equivalent diameter of 1 mm or less,
(11) The production method according to (1), wherein the laminar flow path is a microreaction field.
(12) The organic pigment fine particles obtained by the production method according to any one of (1) to (10), wherein the mode diameter is 1 μm or less,
(13) A method for producing fine organic pigment particles, wherein a solution containing a reaction component is passed through an apparatus having a flow path having an equivalent diameter of 1 mm or less,
(14) The production method according to (13), wherein the organic pigment fine particles are a quinacridone pigment represented by the general formula (I),

(Wherein X and Y are independently a fluorine atom, a chlorine atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, and a COOR _a group (where R _a is a hydrogen atom or a carbon atom) And m and n independently represent 0, 1 or 2.)
(15) The production method according to (13), wherein the organic pigment fine particles are a condensate of an azocarboxylic acid aryl ester and an aromatic diamine, or a condensate of an azodicarboxylic acid diaryl ester and an aromatic amine,
(16) At least one of the solution in which the organic pigment is dissolved and the aqueous medium has a dispersant, and both of them are preferably brought into contact with each other in an apparatus having a flow path having an equivalent diameter of 1 mm or less to make the pigment fine particles. A method for producing a pigment dispersion,
(17) The production method according to (16), wherein at least one of the dispersants is a polymer dispersant.
(18) The production method according to (16), wherein at least one of the dispersants is an anionic dispersant.
(19) The production method according to any one of (16) to (18), comprising at least one of a polymer dispersant and at least one of an anionic dispersant,
(20) The method according to any one of (16) to (19), wherein the organic pigment solution is alkaline.
Achieved by. Furthermore, the present invention was also achieved by the following method.

(21) In order to change the hydrogen ion index (pH), water or an aqueous solution in which at least one dispersant is dissolved is introduced into the flow path from an inlet different from the organic pigment solution, and the two solutions are allowed to flow. (1) to (12) or (16) to (20), the production method according to claim
(22) When a laminar flow is formed in the flow path and the organic pigment fine particles formed in one laminar flow are included, the laminar flow including the organic pigment fine particles at the outlet of the flow path is referred to as another laminar flow. (1) to (12) or (16) to (21), the production method according to
(23) The step of changing the hydrogen ion index (pH) is performed within a temperature range of 5 to 15 ° C., and the temperature change is performed under conditions as small as possible (1) to (12), Or the production method according to (16) to (22),
(24) The method according to (1) to (12) or (16) to (23), wherein the organic pigment is a quinacridone pigment,
(25) The production method according to (1) to (12) or (16) to (23), wherein the organic pigment is a diketopyrrolopyrrole pigment.
(26) The production method according to any one of (1) to (12) or (16) to (23), wherein the organic pigment is a disazo condensation pigment.
(27) The production method according to (1) to (12) or (16) to (23), wherein the organic pigment is a phthalocyanine pigment,
(28) The production method according to (24), wherein the quinacridone pigment is represented by the general formula (I),
(29) The quinacridone pigment represented by the general formula (I) is an oxidation reaction of a 6,13-dihydroquinacridone compound represented by the general formula (II) or a diarylaminoterephthalate represented by the general formula (III) The production method according to (14), which is produced by a cyclization reaction of an acid or an ester compound thereof,

（式中、ＸおよびＹは、独立してフッ素原子、塩素原子、炭素数１〜３のアルキル基、炭素数１〜３のアルコキシ基及びＣＯＯＲ_a基（ここでＲ_aは、水素原子または炭素数１〜１０のアルキル基である）を表し、ｍおよびｎは、独立して０、１または２を表す。）

(In the formula, X and Y are independently a fluorine atom, a chlorine atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, and a COOR _a group (wherein R _a is a hydrogen atom or a carbon atom) And m and n independently represent 0, 1 or 2.)

（式中、Ｘ、Ｙ、ｍおよびｎは前記と同義の基または数を表す。Ｒ_ｂは水素原子、又は炭素数１〜１０のアルキル、アルケニル、アルキニルもしくはアリール基を表す。）

(In the formula, X, Y, m and n represent the same groups or numbers as described above. R _b represents a hydrogen atom or an alkyl, alkenyl, alkynyl or aryl group having 1 to 10 carbon atoms.)

(30) The production method according to (15), wherein the disazo condensation pigment is represented by any one of the following general formulas (IV) and (V).

（式中、Ａｒ_１は２価の芳香族基を表し、Ｄ_１は置換基を表す。）

(In the formula, Ar ₁ represents a divalent aromatic group, and D ₁ represents a substituent.)

（式中、Ａｒ_２は２価の芳香族基を表し、Ｄ_２は置換基を表す。）

(In the formula, Ar ₂ represents a divalent aromatic group, and D ₂ represents a substituent.)

According to the present invention, by performing a flow reaction in a laminar flow channel, pigments and pigment fine particles can be rapidly produced under simple and mild conditions as compared with a conventional method using a flask or the like.
That is, the reaction time can be controlled by a flow reaction using a laminar flow channel, and the precision of reaction temperature control in a narrow space can be used to suppress undesirable side reactions. In addition, in the preparation of micronized pigments, especially pigment dispersants, it is possible to apply a build-up method prepared by synthesis instead of the conventional break-up method by crushing with a mill, and the manufacturing process differs from the conventional scale-up. Since it is based on numbering up (parallelization of devices), the time required for commercialization can be drastically reduced.
In addition, the pigment dispersion obtained by the production method of the present invention can realize a more precise monodispersed state, and by controlling the particle diameter and particle shape, a new function can be added to the dispersion or contained fine particles. It can also be expected to exhibit higher functions than the current product.

The present invention is described in detail below. In this specification, the expression “numerical value A to numerical value B” in the case of representing a physical property value or a characteristic value represents the meaning of “numerical value A or more and numerical value B or less”.
The apparatus used in the present invention has a flow path capable of forming a laminar flow, preferably an apparatus having a flow path (channel) with an equivalent diameter of 10 mm or less, more preferably a flow path with an equivalent diameter of 1 mm or less. It is an apparatus having. First, the equivalent diameter will be described below.

Equivalent diameter, also called equivalent 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 (d _eq ) is defined as d _eq = 4 A / p, using A: the cross-sectional area of the pipe, and p: the wet wetting length (circumferential length) of the pipe. When applied to a circular tube, this equivalent diameter corresponds to the circular tube diameter. The equivalent diameter is used to estimate the flow or heat transfer characteristics of the pipe based on the data of the equivalent circular pipe, and represents the spatial scale (typical length) of the phenomenon. The equivalent diameter is d _eq = 4a ² / 4a = a for a regular square tube with one side a, and for a regular triangle tube with one side a,

流路高さｈの平行平板間の流れではｄ_ｅｑ＝２ｈとなる（例えば、（社）日本機械学会編「機械工学事典」１９９７年、丸善（株）参照）。

In the flow between parallel flat plates having a flow path height h, d _eq = 2h (for example, see “Mechanical Engineering Dictionary” edited by The Japan Society of Mechanical Engineers, 1997, Maruzen Co., Ltd.).

When water is poured into the tube, a thin tube is inserted into its central axis and colored liquid is injected, the colored liquid flows as a single line while the flow rate of water is low, and the water flows on the tube wall. It flows straight in parallel. However, when the flow velocity is increased and reaches a certain flow velocity, the water flow suddenly becomes turbulent, and the colored liquid is mixed with the water flow to become a colored flow. The former flow is called laminar flow, and the latter flow is called turbulent flow.
Whether the flow becomes laminar or turbulent depends on whether the Reynolds number, which is a dimensionless number indicating the flow, is below a certain critical value. The smaller the Reynolds number, the easier it is to form a laminar flow. The Reynolds number Re of the flow in the pipe is expressed by the following equation.
Re = D <υ _x > ρ / μ
D is the equivalent diameter of the tube, <υ _x > is the average cross-sectional velocity, ρ is the density of the fluid, and μ is the viscosity of the fluid. As can be seen from this equation, the smaller the equivalent diameter, the smaller the Reynolds number. Therefore, in the case of an equivalent diameter of μm, a stable laminar flow is easily formed. It can also be seen that the liquid physical properties of density and viscosity also affect the Reynolds number, and the smaller the density and the larger the viscosity, the smaller the Reynolds number and the easier it is to form a laminar flow.
A Reynolds number indicating a critical value is called a critical Reynolds number. The critical Reynolds number is not always constant, but the next value is the standard.
Re <2300 laminar flow
Re> 3000 Turbulence
3000 ≧ Re ≧ 2300 Transient state

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

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

  As shown in the description of the Reynolds number, the formation of a laminar flow is greatly influenced not only by the size of the equivalent diameter but also by the flow conditions including liquid properties such as viscosity and density. Therefore, in the present invention, the equivalent diameter of the flow path is not limited as long as the flow path can be made laminar, but a size capable of easily forming a laminar flow is preferable. Preferably, it is preferably 10 mm or less, and more preferably 1 mm or less that forms a micro reaction field. More preferably, it is 10 micrometers-1 mm, Most preferably, it is 20-300 micrometers.

  A typical reactor having a particularly preferable microscale size channel (channel) of the present invention is generally referred to as a “microreactor” and has recently been greatly developed (for example, W. Ehrfeld, V. Hessel, H. Loewe, “Microreactor”, 1Ed (2000) WILEY-VCH).

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

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

  When a microreactor having such characteristics is used, the reaction time and temperature between solutions can be precisely controlled as compared with a conventional batch system using a large volume tank or the like as a reaction field. In the case of the batch method, the reaction proceeds at the reaction contact surface at the initial stage of mixing, particularly between solutions with a high reaction rate, and the primary product generated by the reaction between the solutions continues to be reacted in the vessel. Therefore, there is a possibility that the product becomes non-uniform or the crystals of the product grow more than necessary and become coarse in the mixing container. On the other hand, according to the microreactor used in the present invention, the solution circulates continuously with almost no stagnation in the mixing container, so that the primary product generated by the reaction between the solutions is in the mixing container. It is possible to suppress the subsequent reaction during the stay, and it is possible to take out pure primary products that were difficult to remove in the past, and also to agglomerate and coarsen crystals in the mixing vessel It becomes difficult to occur.

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

  A method for producing a laminar flow channel used in the present invention will be described below. When the flow path is 1 mm or more in size, it can be made relatively easily by using a conventional machining technique. However, when the size is 1 mm or less, particularly when the size is 500 μm or less, the production becomes extremely difficult. A micro-sized channel (micro channel) is often formed on a solid substrate using a microfabrication technique. Any material can be used as the substrate material as long as it is not easily corroded. For example, metal (for example, stainless steel, hastelloy (Ni—Fe alloy), nickel, aluminum, silver, gold, platinum, tantalum, or titanium), glass, plastic, silicone, Teflon (registered trademark), or ceramics.

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

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

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

  So far, microreactors have been reported on devices aimed at improving reaction efficiency. For example, Japanese Patent Application Laid-Open Nos. 2003-210960, 2003-210963, and 2003-210959 relate to micromixers, and the present invention can use these microdevices.

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

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

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

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

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

  The method used as the fluid control method in the present invention is appropriately selected according to the purpose, but is preferably a continuous flow type pressure driving method.

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

  In the present invention, the production of the pigment or the preparation of the pigment dispersion is performed while flowing in the flow path, that is, by a continuous flow method. Therefore, the reaction time is controlled by the time spent in the flow path. The residence time is determined by the length of the flow path and the introduction speed of the reaction solution when the equivalent diameter is constant. Although there is no restriction | limiting in particular in the length of a flow path, Preferably they are 1 mm or more and 10 m or less, More preferably, they are 5 mm or more and 10 m or less, Especially preferably, they are 10 mm or more and 5 m or less.

  The number of flow paths used in the present invention is appropriately provided in the reaction apparatus, and of course, one may be used, but if necessary, several flow paths are arranged in parallel (numbering up), and the processing amount is Can be increased.

  Representative examples of the reactor used in the present invention are shown in FIGS. Needless to say, the present invention is not limited to these examples.

  1-1 is explanatory drawing of the reactor (10) which has a Y-shaped channel, FIG. 1-2 is sectional drawing of the II line | wire. The shape of the cross section perpendicular to the length direction of the flow path varies depending on the microfabrication technique used, but is a trapezoidal shape or a shape close to a rectangle. When the channel width / depth (especially C, H) is made in a micro size, the solution injected from the introduction port 11 and the introduction port 12 by a pump or the like passes through the introduction channel 13a or the introduction channel 13b. Then, they contact at the fluid confluence 13d, form a stable laminar flow, and flow through the reaction channel 13c. During the laminar flow, the solutes contained in the laminar flows are mixed or reacted by molecular diffusion at the interface between the laminar flows. In some cases, a solute that is very slowly diffusing does not cause diffusive mixing between laminar flows and mixes only after reaching the outlet 14. When the two solutions to be injected are easily mixed in the flask, if the flow path length F is long, the flow of liquid can be uniform at the outlet, but when the flow path length F is short, Laminar flow is maintained up to the outlet. When the two solutions to be injected do not mix in the flask and are separated into layers, the two solutions naturally flow as laminar flows and reach the outlet 14.

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

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

  In the present invention, an organic pigment solution uniformly dissolved in an alkaline or acidic aqueous medium is circulated as a laminar flow in the flow path, and the hydrogen ion index (pH) of the solution is changed in the process to form organic pigment fine particles. And a dispersion containing it, which will be described in detail below.

  The organic pigment used in the present invention is not limited in hue, and may be a magenta pigment, a yellow pigment, or a cyan pigment. Specifically, 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. 20050), C.I. I. Pigment red 144 (C.I. No. 20735), C.I. I. Pigment red 166 (C.I. No. 20730), C.I. I. Pigment red 220 (C.I. No. 20055), C.I. I. Pigment red 221 (C.I. No. 20065), C.I. I. Pigment red 242 (C.I. No. 20067), C.I. I. Pigment red 248, C.I. I. Pigment red 262, or C.I. I. Disazo condensation pigments such as CI Pigment Brown 23 (C.I. No. 20060); I. Pigment yellow 13 (C.I. No. 21100), C.I. I. Pigment yellow 83 (C.I. No. 21108), or C.I. I. Disazo pigments such as CI Pigment Yellow 188 (C.I. No. 21094); I. Pigment red 187 (C.I. No. 12486), C.I. I. Pigment red 170 (C.I. No. 12475), C.I. I. Pigment yellow 74 (C.I. No. 11714), C.I. I. Pigment red 48 (C.I. No. 15865), C.I. I. Pigment red 53 (C.I. No. 15585), C.I. I. Pigment orange 64 (C.I. No. 12760), or C.I. I. Azo pigments such as C.I. Pigment Red 247 (C.I. No. 15915), C.I. I. Indanthrone pigments such as CI Pigment Blue 60 (C.I. No. 69800); I. Pigment green 7 (C.I. No. 74260), C.I. I. Pigment Green 36 (C.I. No. 74265), Pigment Green 37 (C.I. No. 74255), Pigment Blue 16 (C.I. No. 74100), C.I. I. Phthalocyanine pigments such as CI Pigment Blue 75 (C.I. No. 74160: 2) or 15 (C.I. No. 74160); I. Pigment blue 56 (C.I. No. 42800), or C.I. I. Triarylcarbonium pigments such as CI Pigment Blue 61 (C.I. No. 42765: 1); I. Pigment violet 23 (C.I. No. 51319) or C.I. I. Dioxazine pigments such as CI Pigment Violet 37 (C.I. No. 51345); I. Aminoanthraquinone pigments such as CI Pigment Red 177 (C.I. No. 65300); I. Pigment red 254 (C.I. No. 56110), C.I. I. Pigment Red 255 (C.I. No. 561050), C.I. I. Pigment red 264, C.I. I. Pigment red 272 (C.I. No. 561150), C.I. I. Pigment orange 71, or C.I. I. Diketopyrrolopyrrole pigments such as C.I. Pigment Orange 73; I. Thioindigo pigments such as CI Pigment Red 88 (C.I. No. 7313), C.I. Pigment Yellow 139 (C.I. No. 56298), C.I. I. Pigment Orange 66 (C.I. No. 48210) and the like, isoindoline pigments such as C.I. I. Pigment yellow 109 (C.I. No. 56284), or C.I. Pigment Orange 61 (C.I. No. 11295) and the like, isoindolinone pigments such as C.I. I. Pigment Orange 40 (C.I. No. 59700), or C.I. I. Pyranthrone pigments such as CI Pigment Red 216 (C.I. No. 59710), or C.I. I. It is an isoviolanthrone pigment such as CI Pigment Violet 31 (60010).

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

  In the present invention, 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 depends on which conditions the target pigment is easily dissolved. . In general, in the case of a pigment having an alkaline and dissociable group in the molecule, alkali is used, and when there is no alkaline and dissociable group and there are many nitrogen atoms in the molecule that are prone to add protons, acidity is used. For example, quinacridone, diketopyrrolopyrrole, and disazo condensation pigments are alkaline, and phthalocyanine pigments are acidic.

  The base used in the case of 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. Are preferably inorganic bases.

  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 acidic dissolution is preferably 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. It 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 inorganic acid or 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.

  Next, the aqueous medium will be described. The aqueous medium in the present invention is water alone or a mixed solvent of water-soluble organic solvents. The addition of an organic solvent is not sufficient with water alone to dissolve the pigment and dispersant uniformly, and when water alone is insufficient to obtain the viscosity required to flow through the flow path, Although it is carried out when necessary for the formation of a stream and is not always necessary, in many cases a water-soluble organic solvent is added. Examples of the organic solvent to be added include ethylene glycol, propylene glycol, diethylene glycol, polyethylene glycol, thiodiglycol, dithiodiglycol, 2-methyl-1,3-propanediol, 1,2,6-hexanetriol, and acetylene glycol derivatives. , Polyhydric alcohol solvents such as glycerin or trimethylolpropane, polyvalent alcohols such as ethylene glycol monomethyl (or ethyl) ether, diethylene glycol monomethyl (or ethyl) ether, or triethylene glycol monoethyl (or butyl) ether Lower monoalkyl ether solvent of alcohol, ethylene glycol dimethyl ether (monoglyme), diethylene glycol dimethyl ether (diglyme), or tri Polyether solvents such as tylene glycol dimethyl ether (triglyme), dimethylformamide, dimethylacetamide, 2-pyrrolidone, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, urea, tetramethylurea, etc. Amide solvents, sulfur-containing solvents such as sulfolane, dimethyl sulfoxide, or 3-sulfolene, polyfunctional solvents such as diacetone alcohol and diethanolamine, acetic acid, maleic acid, docosahexaenoic acid, trichloroacetic acid, or trifluoroacetic acid. Examples thereof include carboxylic acid solvents, methanesulfonic acid, and sulfonic acid solvents such as trifluorosulfonic acid. Two or more of these solvents may be mixed and used.

  A preferred organic solvent is an amide solvent or a sulfur-containing solvent in the case of alkali, a carboxylic acid solvent, a sulfur solvent or a sulfonic acid solvent in the case of acid, and more preferably a sulfur-containing solvent in the case of alkali. If it is acidic, it is a sulfonic acid solvent. Particularly preferred is dimethyl sulfoxide (DMSO) when alkaline, and methanesulfonic acid when acidic.

  The mixing ratio of water and organic solvent is a ratio that can be uniformly dissolved, and is not particularly limited. Preferably, in the case of alkaline, 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. Preferably, water / organic solvent (organic acid) = 0.005 to 0.1 (mass ratio).

  In the present invention, it is preferable to introduce a uniformly dissolved solution into the flow path. When the suspension is added, the particle size becomes large, or the pigment particles become wide in particle distribution. In some cases, the flow path is easily blocked. The meaning of “uniformly dissolved” is a solution in which almost no turbidity is observed when observed under visible light. In the present invention, the solution is obtained through a microfilter of 1 μm or less, or filtered when passed through a 1 μm filter. A solution containing no substance is defined as a uniformly dissolved solution.

Next, the hydrogen ion index (pH) will be described. The hydrogen ion index (pH) is a common logarithm of the reciprocal of the hydrogen ion concentration (molar concentration), and is sometimes called the hydrogen index. The hydrogen ion concentration is the concentration of hydrogen ions H ⁺ in the solution, and means the number of moles of hydrogen ions present in 1 L of solution. Since the hydrogen ion concentration varies within a very wide range, it is usually expressed using the hydrogen ion index (pH). For example, pure water contains ^10-7 moles of hydrogen ions at 1 atmosphere and 25 ° C, so its pH is 7 and neutral. An aqueous solution with pH <7 is acidic, and an aqueous solution with pH> 7 is alkaline. As a method for measuring the pH value, there are a potentiometric method and a colorimetric method.

  In the present invention, the hydrogen ion index (pH) is changed in the course of flowing through the flow path to produce pigment fine particles, and the method has a flow path having an inlet different from the inlet of the uniform solution of the organic pigment, For example, it is performed using a flow path having at least two inlets as shown in FIG. 1-1 or FIG. Specifically, a uniform solution of the organic pigment is introduced into the introduction port 11 in FIG. 1-1 or the introduction port 21 in FIG. 2-1, and then introduced into the introduction port 12 in FIG. 1-1 or the introduction port 22 in FIG. 2-1. Neutral, acidic or alkaline water or an aqueous solution in which a dispersant is dissolved is introduced, and both solutions are brought into contact with each other in the flow path 13c or 23c, whereby the hydrogen ion concentration of the solution containing the organic pigment, that is, the hydrogen ion index (PH) is changed to neutral (pH 7). When the equivalent diameter of the channel is microscale, the Reynolds number is small, so a stable laminar flow (cylindrical laminar flow in Fig. 2-1) is formed, and water and ions diffuse through the stable interface between the two liquid layers. The hydrogen ion exponent (pH) of the solution containing the organic pigment moves and gradually 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 gradually precipitates as fine particles as the hydrogen ion index (pH) of a solution containing an organic pigment 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, preferably pH 16.0 when pigment fine particles are produced from a pigment dissolved in an alkaline aqueous medium. In the range of 1 to 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, preferably in the range of pH 1.5 to 4.0. It is. 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 encourage the precipitation of the organic pigment.

  Since the pigment fine particles generated in the microscale channel do not diffuse and flow to the outlet while being contained in one laminar flow, the flow having the outlet designed as shown in FIG. 3-1 or FIG. When a road device is used, a laminar flow containing organic pigment fine particles can be separated. When this method is used, a concentrated pigment dispersion can be obtained, and at the same time, the water-soluble organic solvent, alkaline or acidic water used to prepare the uniform solution, and excess dispersant can be removed. . Further, the two liquids are finally mixed, so that it is possible to prevent the crystals from becoming coarse and the pigment crystals from being altered.

  The reaction temperature in the flow path in the case of producing pigment fine particles is preferably within a range where the solvent does not solidify or vaporize, but is preferably -20 to 90 ° C, more preferably 0 to 50 ° C. Especially preferably, it is 5-15 degreeC.

The velocity (flow rate) of the fluid flowing in the flow channel when producing pigment fine particles is advantageously 0.1 mL to 300 L / hr, preferably 0.2 mL to 30 L / hr, more preferably 0.5 mL to 15 L / hr. hr, particularly preferably 1.0 mL to 6 L / hr.
In the present invention, the concentration range of the substrate (organic pigment and its reaction component) flowing through the flow path is usually 0.5 to 20% by mass, preferably 1.0 to 10% by mass.

  In the method for producing organic pigment fine particles of the present invention, a dispersant can be added in a solution containing an organic pigment or / and in an aqueous solution (aqueous medium) for changing the hydrogen ion index (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. In the present invention, as such a dispersant, an anionic, cationic, amphoteric, nonionic or pigmentary low molecular or high molecular 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. As the N-acyl-N-alkyltaurine salt, those described in JP-A-3-273067 are preferable. 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 defined as a 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 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, vinylpyrrolidone-vinyl acetate copolymer, polyethylene oxide / propylene oxide block copolymer, polyacrylate, polyvinyl sulfate, poly (4-vinylpyridine) salt, polyamide, polyallylamine salt, Condensed naphthalene sulfonate, styrene-acrylate copolymer, styrene-methacrylate copolymer, acrylate ester-acrylate copolymer, acrylate ester Methacrylate copolymer, methacrylate ester-acrylate copolymer, methacrylate ester-methacrylate copolymer, styrene-itaconate copolymer, itaconate-itaconate copolymer, vinyl Examples thereof include naphthalene-acrylate copolymer, vinyl naphthalene-methacrylate copolymer, vinyl naphthalene-itaconate copolymer, cellulose derivative, starch derivative and the like. In addition, natural polymers such as alginate, gelatin, albumin, casein, gum arabic, tonganto gum and lignin sulfonate can also be used. Of these, polyvinylpyrrolidone is preferable. These polymers can be used alone or in combination of two or more.

  A preferred embodiment includes 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.

  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, more preferably 1 to 100 parts by mass of the pigment. It is the range of -500 mass parts, More preferably, it is the range of 10-250 mass parts. If the amount is less than 0.1 parts by mass, the dispersion stability of the organic pigment fine particles may not be improved.

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

  The particle size of the fine particles is uniform, that is, the monodisperse fine particle system not only has the same size of the contained particles, but also shows no variation between particles in the chemical composition and crystal structure within the particles. Therefore, it is an important factor that determines the performance of particles. In particular, in the case of ultrafine particles having a particle size of nanometer, importance is attached as a factor governing the characteristics of the particles. The method of the present invention is an excellent method not only for controlling the size of particles but also for adjusting the size. An arithmetic standard deviation value is used as an index indicating that the sizes are uniform, and the arithmetic standard deviation value of the pigment fine particles produced according to the present invention is preferably 130 nm or less, particularly preferably 80 nm or less. The arithmetic standard deviation value is a method of obtaining the standard deviation by regarding the particle size distribution as a normal distribution, and is a value obtained by dividing the value obtained by subtracting the 16% particle size from the 84% particle size of the integrated distribution by 2.

  The method for producing an organic pigment of the present invention can be widely applied to the above-mentioned pigments, but specifically, a method for producing an unsubstituted or substituted quinacridone pigment will be described as an example. In the present invention, the unsubstituted or substituted quinacridone pigment represented by the general formula (I) is produced in an apparatus having a flow path forming a laminar flow. The substituent of the general formula (I) will be described.

X and Y are a fluorine atom, a chlorine atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, or a COOR _a group (where R _a is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms). In detail, when a group other than a fluorine atom, a chlorine atom and a carboxyl group is described in detail, an alkyl group of methyl, ethyl, propyl or isopropyl, an alkoxy group of methoxy, ethoxy, propyloxy or isopropoxy, or methoxycarbonyl Represents an alkoxycarbonyl group such as ethoxycarbonyl, isopropoxycarbonyl, or octyloxycarbonyl.

  X and Y are preferably a chlorine atom or an alkyl group, and particularly preferably a methyl group.

  m and n independently represent 0, 1 or 2, but preferably 1.

  Specific examples of preferable quinacridone pigments to be synthesized include unsubstituted or substituted quinacridone such as unsubstituted quinacridone, 2,9-dimethylquinacridone, and 4,11-dichloroquinacridone, and solid solutions thereof. I. Examples of numbers include, but are not limited to, Pigment Violet 19, Pigment Red 122, Pigment Red 207, Pigment Orange 48, Pigment Orange 49, Pigment Red 209, Pigment Red 206, and Pigment Violet 42.

  The production of an unsubstituted or substituted quinacridone pigment can be carried out according to a usual synthesis method, preferably by applying it to the aforementioned apparatus having a flow path having an equivalent diameter of 10 mm or less.

  Examples of the solvent that can be used in the present invention include the aforementioned organic solvents, dispersants, surfactants, water, and combinations thereof. Further, for example, a water-soluble organic solvent added to the ink composition and other components may be further added as necessary. As these solvent components, for example, components of a pigment dispersant as described in JP-A-2002-194263 and JP-A-2003-26972 can be applied.

  The reaction fluids may be fluids that are mixed with each other or fluids that are not mixed. Mixed fluids are solutions using the same or relatively similar organic solvent, or solutions using a highly polar organic solvent such as methanol and water. Non-mixed fluids are hexane. And a solution using a low polarity solvent such as methanol and a solution using a high polarity solvent such as methanol.

  When a gas such as air or oxygen is used as the oxidizing agent, they can be dissolved in the reaction fluid or introduced as a gas into the flow path. Preferably, a method of introducing as a gas is taken.

  The reaction temperature is desirably within the range where the solvent does not coagulate or vaporize, but is preferably -20 ° C to 250 ° C, more preferably 20 ° C to 150 ° C, still more preferably 40 ° C to 120 ° C, and most preferably. Is 60 ° C to 100 ° C.

  The flow rate is advantageously between 0.1 mL and 300 L / hr, preferably between 0.2 mL and 30 L / hr, more preferably between 0.5 mL and 15 L / hr, particularly preferably between 1.0 mL and 6 L / hr.

  There are various methods for synthesizing a quinacridone pigment that can be applied to a microreactor in the present invention, and any method can be applied. As a method for producing the quinacridone pigment of the present invention, two reaction schemes are shown below as preferable reactions. The quinacridone pigment can be produced in an apparatus having a flow path with an equivalent diameter of preferably 10 mm or less, more preferably 1 mm or less.

  As a method of synthesizing by oxidation reaction of 6,13-dihydroquinacridone (Scheme 1), a method using air or oxygen (methods described in JP-A-11-209441 and JP-A-2001-115052 as reference reaction examples) ) And those using hydrogen peroxide (the method described in JP-A-2000-226530 as a reference reaction example) are preferable from the viewpoint of environmental load.

式中、Ｘ、Ｙ、ｍおよびｎは前記と同義の基を表す。

In the formula, X, Y, m and n represent the same groups as described above.

  The ring-closing reaction of diarylaminoterephthalic acid or its ester (Scheme 2) is carried out using an appropriate condensing agent (methods described in JP-A-2001-335577 and JP-A-2000-103980 as examples of reference reactions). .

In the formula, X, Y, m and n represent the same groups as described above. The substituent R _b is a hydrogen atom or an alkyl group, alkenyl group, alkynyl group, or aryl group having 1 to 10 carbon atoms. For example, examples of the alkyl group include methyl, ethyl, propyl, butyl and the like. Examples of the alkenyl group include vinyl and allyl, examples of the alkenyl group include an ethynyl group, and examples of the aryl group include a phenyl group. These substituents may further have a substituent. An aryl group is preferable, and a phenyl group is particularly preferable.

Next, the manufacturing method of a disazo condensation pigment is demonstrated.
The disazo condensation pigment can be produced in an apparatus (such as a microreactor) having a flow path having an equivalent diameter of preferably 10 mm or less, more preferably 1 mm or less. As the disazo condensation pigment, any one of the general formulas (IV) and (V) can be used. Are preferred. These substituents Ar ₁ , Ar ₂ , D ₁ and D ₂ will be described below.

Ar ₁ and Ar ₂ represent a divalent aromatic group, specifically a divalent aromatic group having 6 to 20 carbon atoms, preferably a divalent aromatic group having 6 to 10 carbon atoms. is there. Specific examples of the divalent aromatic group include 1,4-phenylene, 2-chloro-5-methyl-1,4-phenylene, 2,5-dichloro-1,4-phenylene, and 2,5-dimethyl. -1,4-phenylene, 2-chloro-1,4-phenylene, 2,2′-dichloro-4,4′-biphenylene, benzanilide-4,4′-diyl, 4,4′-biphenylene, 1,4 An aromatic group of naphthylene or 1,5-naphthylene, among which 2-chloro-5-methyl-1,4-phenylene, 2,5-dichloro-1,4-phenylene, 2, 5-dimethyl-1,4-phenylene or 1,4-phenylene.

D ₁ and D ₂ each represent a substituent, for example, a group represented by any one of the following general formulas (a) and (b).

In the formula, * represents a binding site. R ₁ , R ₂ and R ₃ may be the same or different and each represents a group selected from the group consisting of a methyl group, a chlorine atom, a —CF ₃ group and a 4′-chlorophenoxy group. R ₄ and R ₅ may be the same or different and are each a chlorine atom, a methyl group, a —CF ₃ group, a —CO ₂ CH ₂ CH ₂ Cl group, a —COOR _c group (R _c is a group having 1 to 4 carbon atoms). And represents a group selected from the group consisting of a nitro group.

Preferably, D ₁ is a substituent represented by the general formula (b), and D ₂ is a substituent represented by the general formula (a).

  A particularly preferred specific example of the disazo condensation pigment to be synthesized is C.I. I. Pigment yellow 93, 94, 95, 128, 166; I. Pigment orange 31, 55; C.I. I. Pigment Red 139, 140, 141, 143, 144, 166, 214, 217, 218, 220, 221, 242, 248, 262; I. Pigment Brown 23, 41, and 42.

  The amide bond forming reaction of a preferred disazo condensation pigment applied to a microreactor in the method of the present invention is shown in Schemes 3 and 4 below. The reaction is a condensation of an aryl ester of azocarboxylic acid with an aromatic diamine.

Here, Ar _a and Ar _b represent a phenol derivative which is an ester component.

  Specific examples of the aryl ester of azocarboxylic acid that can be used in such a reaction are shown below, but the present invention is not limited thereto.

  Moreover, although the specific example of aromatic diamine is shown below, this invention is not limited to these.

  The molar ratio of the aromatic diamine and the aryl ester of azocarboxylic acid is preferably 1: 0.5 to 1:10, more preferably 1: 1 to 1: 5, and particularly preferably 1: 2 to 1: 4.

In the general formula (V), when the substituent represented by D ₂ is represented by the general formula (a), the condensation of a diaryl ester of azodicarboxylic acid with an aromatic amine as shown in Scheme 5 is also possible. Is possible.

Examples of Ar _b include the following structures. * Represents a binding site.

  Specific examples of the diaryl ester of azodicarboxylic acid that can be used for such a reaction are shown below, but the present invention is not limited thereto.

  Moreover, although the specific example of an aromatic amine is shown below, this invention is not limited to these.

  The molar ratio of the diaryl ester of azodicarboxylic acid to the aromatic amine is preferably 1: 0.5 to 1:10, more preferably 1: 1 to 1: 5, and particularly preferably 1: 2 to 1: 4.

  The reaction temperature and the reaction flow rate are the same as in the case of producing a quinacridone pigment.

  Solvents that can be used in the quinacridone pigments and disazo condensation pigments include organic solvents, dispersants, surfactants, or water, and combinations thereof. Specifically, ethers such as tetrahydrofuran, dioxane, dimethoxyethane and diglyme, esters such as ethyl acetate and butyl acetate, ketones such as methyl ethyl ketone, 2-methyl-4-pentanone and cyclohexanone, ethanol, ethylene glycol and diethylene glycol Alcohols such as acetonitrile, nitriles such as acetonitrile and propionitrile, amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone and N, N-dimethylimidazolidone, dimethyl sulfoxide, And sulfur-containing solvents such as sulfolane. From the viewpoint of solubility of raw materials and products, amide solvents, dimethyl sulfoxide, sulfolane and the like are preferable. Further, for example, a water-soluble organic solvent added to the ink composition and other components may be further added as necessary. As these solvent components, for example, constituents of a pigment dispersant described in JP-A Nos. 2002-194263 and 2003-26972 can be applied.

  The reaction fluids may be fluids that are mixed with each other or fluids that are not mixed. Mixed fluids are solutions using the same or relatively similar organic solvent, or solutions using a highly polar organic solvent such as methanol and water. Non-mixed fluids are hexane. And a solution using a low polarity solvent such as methanol and a solution using a high polarity solvent such as methanol.

  The quinacridone pigment and disazo condensation pigment obtained by the reaction are separated from the reaction solution by filtration or centrifugation, and are washed with an amide solvent such as N, N-dimethylacetamide and obtained with high purity.

  The purity of quinacridone was determined by the following method after the produced quinacridone was taken out, washed and sufficiently dried. 2 mg of quinacridone is precisely weighed and dissolved in 100 mL of 95% concentrated sulfuric acid at 10 ° C. or lower, UV absorption is measured, an absorption value at 606 nm is obtained, and compared with an absorption value at the same wavelength of a standard product. Purity. In addition, since the wavelength of substituted quinacridone is shifted as compared with that of the unsubstituted quinacridone, the optimum wavelength of the standard product of the substituted quinacridone to be measured was adjusted in the same manner.

  The purity of the disazo condensation pigment is measured by taking out the produced disazo condensation pigment, washing it, drying it thoroughly, solubilizing it with a sodium hydroxide-dimethylsulfoxide mixed solvent, etc. Determined by comparing spectra.

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

  The pH shown in the examples was measured with a glass electrode type hydrogen ion concentration meter HM-40V (measurement range pH 0 to 14) of Toa Denpa Kogyo Co., Ltd. The particle size distribution was measured with Nikkiso Co., Ltd. Microtrac UPA150. For the TEM measurement, a transmission electron microscope JEM-2000FX manufactured by JEOL Ltd. was used.

(Example 1)
1.5 g of 2,9-dimethylquinacridone was dissolved in 13.5 g of dimethyl sulfoxide, 2.68 mL of a 5 mol / L aqueous sodium hydroxide solution, and 0.75 g of a dispersant polyvinylpyrrolidone (manufactured by Wako Pure Chemical Industries, Ltd., K30) at room temperature. (IA liquid). The pH of the IA solution exceeded the measurement limit (pH 14) and could not be measured. Dispersant N-oleoyl-N-methyltaurine sodium salt 0.75 g and distilled water 90 mL were mixed (IIA solution). The pH of the IIA solution was 7.70. Impurities such as dust were removed by passing these through a 0.45 μm microfilter (Fuji Photo Film Co., Ltd.). Next, the reaction was performed by the following procedure using the reaction apparatus of FIG. Two Teflon (registered trademark) tubes with a length of 50 cm and an equivalent diameter of 1 mm are connected to two inlets of a Teflon (registered trademark) Y-shaped connector having an equivalent diameter of 500 μm using a connector, and IA liquid and The syringe containing the IIA solution was connected and set in the pump. A Teflon (registered trademark) tube having a length of 1 m and an equivalent diameter of 500 μm was connected to the outlet of the connector. When the IA liquid is sent out at a liquid feeding speed of 1 mL / h and the IIA liquid is sent out at a liquid feeding speed of 6 mL / h, the flow path becomes a laminar flow (Reynolds number: about 5.0), and a dispersion of 2,9-dimethylquinacridone is obtained. Therefore, this was collected from the tip of the tube and used as Sample 1 of the present invention. The pH of Sample 1 was 13.06. The mode diameter was 120 nm and the arithmetic standard deviation was 58 nm.

(Comparative Example 1)
Next, when the IA solution was added to 6 mL of the IIA solution in a beaker at room temperature while stirring with a stirrer, a dispersion of 2,9-dimethylquinacridone was obtained. This was designated as Comparative Sample 1. When the particle sizes and particle size distributions of the dispersions obtained in Sample 1 and Comparative Sample 1 were compared using a dynamic light scattering particle size measuring apparatus, the particle size of the dispersion in Sample 1 was the mode diameter of Comparative Sample 1. It was found that the distribution width was smaller than 144 nm and the arithmetic standard deviation of 77 nm.

(Example 2)
0.15 g of 2,9-dimethylquinacridone was dissolved in 13.35 mL of dimethyl sulfoxide, 1.65 mL of 0.8 mol / L potassium hydroxide aqueous solution, and 0.75 g of polyvinylpyrrolidone (manufactured by Wako Pure Chemical Industries, Ltd., K30) at room temperature. (IB solution). The pH of the IB solution exceeded the measurement limit and could not be measured. The IB solution and the IIA solution prepared in Example 1 were passed through a 0.45 μm microfilter (manufactured by Fuji Photo Film Co., Ltd.) to remove impurities such as dust and obtain transparent solutions. Next, the reaction was carried out by the following procedure using the reaction apparatus described below. Two Teflon (registered trademark) tubes with a length of 50 cm and an equivalent diameter of 1 mm are connected to the two inlets of a Teflon (registered trademark) Y-shaped connector having an equivalent diameter of 500 μm using a connector, and IB liquid and The syringe containing the IIA solution was connected and set in the pump. A Teflon (registered trademark) tube having a length of 1 m and an equivalent diameter of 500 μm was connected to the outlet of the connector. When the IB solution is sent at 1.0 mL / h and the IIA solution is sent at a delivery rate of 30.0 mL / h, the flow path becomes laminar (Reynolds number: about 21.9) and 2,9-dimethylquinacridone is dispersed. Since a liquid was obtained, it was collected from the tip of the tube and used as Sample 2 of the present invention. The pH of Sample 2 was 10.49. When this was measured using a dynamic light scattering particle size measuring apparatus, it was found that the mode diameter was 51 nm, the arithmetic standard deviation was 28 nm, and the distribution width was very small. Furthermore, when observed with a transmission electron microscope (TEM), it had a rounded particle shape.

(Comparative Example 2)
Next, 0.5 mL of IB solution was added to 3.0 mL of the IIA solution in a beaker at room temperature while stirring with a stirrer to obtain a dispersion of 2,9-dimethylquinacridone. This was designated as Comparative Sample 2. The pH of Comparative Sample 2 was 11.81. When this was measured using a dynamic light scattering particle diameter measuring apparatus, the mode diameter was 93 nm, the arithmetic standard deviation was 57 nm, and both the particle diameter and the distribution width were large. Furthermore, when it observed with the transmission electron microscope (TEM), it was acicular.

(Comparative Example 3)
Furthermore, the Teflon (registered trademark) tube used in the reactor of Example 2 and the Teflon (registered trademark) Y-shaped connector all had an equivalent diameter of 20 mm, the IB solution was 26.49 L / h, and the IIA solution was 122. Dispersion liquid was obtained by sending out at a feed speed of 4 L / h. The flow in the channel (Reynolds number; about 2639.6) was unstable. This was designated as Comparative Sample 3. The pH of Comparative Sample 3 was 12.56. When this was measured using a dynamic light scattering particle diameter measuring apparatus, it was found that the mode diameter was 277 nm, the arithmetic standard deviation was 140 nm, the particle diameter was large, and the distribution width was very wide.

  Comparison of Sample 2 of the present invention and Comparative Sample 2 showed that when a pigment was prepared in the flow path, the particle mode diameter and distribution width were reduced and the particle diameters were uniform. Further, the comparison between the sample 2 of the present invention and the comparative sample 3 showed that the equivalent diameter of the flow path is 10 mm or less, particularly when the scale is microscale, the particle mode diameter is small and the distribution width is considerably small.

(Example 3)
0.01 g of 2,9-dimethylquinacridone was dissolved in 10.0 mL of dimethyl sulfoxide, 0.11 mL of 0.8N aqueous potassium hydroxide solution and 0.05 g of polyvinylpyrrolidone (manufactured by Wako Pure Chemical Industries, Ltd., K30) at room temperature (IC liquid). The pH of the IC solution exceeded the measurement limit and could not be measured. This was passed through a 0.45 μm microfilter (manufactured by Fuji Photo Film Co., Ltd.) to remove impurities such as dust, and a transparent solution was obtained. Flow path width A: 100 μm, flow path width B: 100 μm, flow path width C: 100 μm, flow path length F: 12 cm, flow path depth H: Y-shaped as shown in FIG. In a reaction apparatus having a flow path, two Teflon (registered trademark) tubes are connected to the introduction port 11 and the introduction port 12 using connectors, and syringes containing only IC solution and distilled water are connected to the ends of the tubes, respectively. Set to pump. A Teflon (registered trademark) tube was also connected to the discharge port 14 using a connector. When the IC solution is sent out at a feed rate of 20 μL / min and distilled water is sent out at a rate of 20 μL / min, the inside of the channel becomes a laminar flow (Reynolds number: about 8.5), and a dispersion of 2,9-dimethylquinacridone is obtained. This was collected from the tip of the tube. The pH of this dispersion was 13.93. When this was measured using a dynamic light scattering particle size measuring apparatus, the mode diameter was 50 nm.

Example 4
A reaction apparatus having a cylindrical flow path as shown in FIG. 2-1 having a flow path diameter D of 200 μm, a flow path diameter E of 620 μm, a flow path length G of 10 cm, and two Teflon (registered trademark) tubes using a connector. Then, the syringe was connected to the inlet 21 and the inlet 22, and the syringes containing the IB liquid and the IIA liquid prepared in Examples 1 and 2 were connected to each other, and set in the pump. When the IB liquid is sent at a liquid feeding speed of 1.0 mL / h and the IIA liquid is sent at a liquid feeding speed of 30.0 mL / h, the inside of the flow path becomes a laminar flow (Reynolds number: about 17.7), and 2,9-dimethylquinacridone is dispersed. Since a liquid was obtained, it was collected from the outlet 24. The pH of this dispersion was 10.44. When this was measured using a dynamic light scattering particle size measuring apparatus, it was found that the mode diameter was 94 nm, the arithmetic standard deviation was 77 nm, and the distribution width was very small.

(Reference Example 1)
0.01 g of 2,9-dimethylquinacridone was mixed with 10 mL of dimethyl sulfoxide, 0.04 mL of 0.8 mol / L potassium hydroxide aqueous solution and 0.05 g of polyvinylpyrrolidone (manufactured by Wako Pure Chemical Industries, Ltd., K30) at room temperature (ID liquid). The pH of the ID solution was 12.74. Although this ID solution was suspended, it was used as it was without passing through a 0.45 μm microfilter (manufactured by Fuji Photo Film Co., Ltd.). A glass Y-shaped channel according to FIG. 1-1 having a channel width A: 100 μm, a channel width B: 100 μm, a channel width C: 100 μm, a channel length F: 12 cm, a channel depth H: 40 μm In the reaction apparatus having the above, two Teflon (registered trademark) tubes were connected to the introduction port 11 and the introduction port 12 using connectors, and the ID solution and the IIA solution prepared in Example 1 were respectively added to the syringes. And connected to the pump. A Teflon (registered trademark) tube was also connected to the discharge port 14 using a connector. When the ID liquid was sent out at a liquid feed speed of 20 μL / min and the IIA liquid was sent out at a liquid feed speed of 20 μL / min, the flow path was blocked when these two liquids joined. This shows that it is important to use a uniformly dissolved solution in the method of the present invention using a reactor having a Y-shaped channel.

(Reference Example 2)
In the reaction apparatus having the cylindrical flow path shown in FIG. 2-1 having a flow path diameter D: 200 μm, a flow path diameter E: 620 μm, a flow path length G: 10 cm, two Teflon (registered trademark) tubes are used with a connector. Connected to the inlet 21 and the inlet 22, the syringes containing the ID solution prepared in Reference Example 1 and the IIA solution prepared in Example 1 were connected to each other and set in a pump. When the ID liquid was sent out at a liquid feeding speed of 1.0 mL / h and the IIA liquid was sent out at a liquid feeding speed of 30.0 mL / h, the flow path was gradually blocked at the portion where these two liquids joined. From this, it can be seen that it is important to use a uniformly dissolved solution in the method of the present invention using a reactor having a cylindrical flow path.

(Example 5)
Channel width I: 100 μm, Channel width J: 100 μm, Channel width K: 100 μm, Channel width L: 100 μm, Channel width M: 100 μm, Channel length Q: 2 cm, Channel depth S: 40 μm In the reaction apparatus that can be separated at the discharge port having the Y-shaped flow path shown in FIG. 3-1, two Teflon (registered trademark) tubes are connected to the introduction port 31 and the introduction port 32 using connectors, Syringes containing the IB solution prepared in Example 3 and the IIA solution prepared in Example 1 were connected and set in a pump. Teflon (registered trademark) tubes were also connected to the discharge port 34 and the discharge port 35 using connectors. When the IB solution is sent at a rate of 10 μL / min and the IIA solution is sent at a rate of 60 μL / min, the dispersion layer of 2,9-dimethylquinacridone is laminar in the flow path (33) (Reynolds number: about 14.9). As a result, the dispersion layer could be separated into the discharge port 34 and the other liquid layers could be separated into the discharge port 35 at the fluid diversion point 33e. This made it possible to obtain a highly concentrated dispersion. The pH of the sample obtained from the outlet 34 was 12.46, and the pH of the sample obtained from the outlet 35 was 11.74.

(Example 6)
In a reactor that can be separated by a discharge port having a cylindrical flow channel as shown in FIG. 4 having a flow channel diameter N: 100 μm, a flow channel diameter P: 300 μm, a flow channel diameter O: 100 μm, a flow channel length R; (Registered trademark) Two tubes are connected to the inlet 41 and the inlet 42 using connectors, and syringes respectively containing the IC solution prepared in Example 3 and the IIA solution prepared in Example 1 are connected to the tubes. Connected and set to pump. Teflon (registered trademark) tubes were also connected to the discharge ports 44 and 45 using connectors. When the ID solution is sent out at a feed rate of 10 μL / min and the IIA solution is sent out at a rate of 30 μL / min, a dispersion of 2,9-dimethylquinacridone is flowed in a cylindrical laminar flow (Reynolds number; about 2) in the passage (reaction passage 43c). 83), the cylindrical laminar flow containing the dispersion liquid can be separated to the discharge port 45 and the other liquids can be separated to the discharge port 44 at the fluid branch point 43e. As a result, it was possible to obtain a highly concentrated dispersion using a cylindrical tube microreactor.

(Comparative Example 4)
Comparative Example of Invention According to Claim 5 IE solution obtained by removing polyvinylpyrrolidone (manufactured by Wako Pure Chemical Industries, Ltd., K30) and N-oleoyl-N-methyltaurine sodium salt from the IB solution of Example 2 and distillation Water was fed at 1.0 mL / h and 6.0 mL / h, respectively, and in the reactor used in Example 2, devices such as Teflon (registered trademark) Y-shaped connector and Teflon (registered trademark) tube were changed. The experiment was conducted without. When the obtained dispersion was measured using a dynamic light scattering particle size measuring apparatus, the mode diameter was 2.80 μm and the arithmetic standard deviation was 0.89 μm, and both the particle size and the arithmetic standard deviation were very large. This result shows that the dispersant is important for obtaining nano-sized fine particles in the present invention.

(Example 7)
Pigment Yellow 93 (1.0 g) was dissolved at room temperature in 10.0 g of dimethyl sulfoxide, 1.3 mL of a 5 mol / L sodium hydroxide aqueous solution, and 0.5 g of a dispersant polyvinylpyrrolidone (manufactured by Wako Pure Chemical Industries, Ltd., K30) (IF liquid). On the other hand, 0.5 g of dispersing agent N-oleoyl-N-methyltaurine sodium salt and 60 mL of distilled water were mixed (IIB solution). Impurities such as dust were removed by passing these through a 0.45 μm microfilter (Fuji Photo Film Co., Ltd.). Next, the reaction was performed according to the following procedure using the reaction apparatus described below. Two Teflon (registered trademark) tubes with a length of 50 cm and an equivalent diameter of 1 mm are connected to the two inlets of a Teflon (registered trademark) Y-shaped connector having an equivalent diameter of 500 μm using a connector, respectively, The syringe containing the IIB solution was connected and set in the pump. A Teflon (registered trademark) tube having a length of 1 m and an equivalent diameter of 500 μm was connected to the outlet using a connector. The IF liquid was sent out at 1 ml / h and the IIB liquid was sent out at a feeding speed of 6 mL / h, and a dispersion layer of Pigment Yellow 93 was obtained as a laminar flow (Reynolds number: about 4.9) in the flow path. This was collected from the tip of the tube. This was designated as Sample 3 of the present invention. At this time, the mode diameter was 133 nm and the arithmetic standard deviation was 69 nm.

(Comparative Example 5)
Next, when the IF solution was added to 6 mL of the IIB solution using a stirrer at room temperature, a dispersion of Pigment Yellow 93 was obtained. This was designated as Comparative Sample 4. When the pigment particle diameters of Sample 3 and Comparative Sample 4 were compared using a dynamic light scattering particle size measuring device, the mode diameter of Comparative Sample 4 was 189 nm and the arithmetic standard deviation was 98 nm. It was found that the diameter was smaller than that of the comparative sample 4 and the distribution width was small.

(Example 8)
In Example 4, 2,9-dimethylquinacridone in the IB liquid was changed to an equimolar amount of Pigment Yellow 93, and a pigment dispersion was obtained without changing other conditions. When observed with a transmission electron microscope (TEM), the primary particles had a rounded particle shape with an average particle size of 12 nm.

Example 9
In Example 4, 2,9-dimethylquinacridone in the IB liquid was changed to an equimolar amount of Pigment Red 254, and a pigment dispersion liquid was obtained without changing other conditions. When observed with a transmission electron microscope (TEM), the primary particles had a rounded particle shape with an average particle size of 9 nm.

(Example 10)
IG solution was prepared by dissolving 1.2 g of Pigment Blue 15 (manufactured by Tokyo Chemical Industry Co., Ltd.) in 10 mL of 95% sulfuric acid at room temperature. A IIC solution was prepared by mixing 6.0 g of polyvinylpyrrolidone (manufactured by Wako Pure Chemical Industries, Ltd., K30), 6.0 g of N-oleoyl-N-methyltaurine sodium salt and 240 mL of distilled water. These were passed through a 0.45 μm microfilter to remove impurities such as dust, and transparent solutions were obtained. A dispersion was prepared under the same conditions as in Example 4 except that the IB liquid used in Example 4 was changed to the IG liquid and the IIA liquid was changed to the IIC liquid. When observed with a transmission electron microscope (TEM), the average particle diameter of the primary particles had a rounded particle shape of 15 nm.

Example 11 Synthesis of 2,9-dimethylquinacridone by oxidation reaction 2,9-dimethyl-6,13-dihydroquinacridone, 2.0 g of 5 mol / L aqueous sodium hydroxide solution 10.0 mL, 18 g of polyethylene glycol 400 were added And stirred at room temperature. The resulting dark green solution was designated as Solution A. Solution A was fed at 3.0 mL / h using a syringe pump. Moreover, 30 mass% hydrogen peroxide solution was sent as the solution B at a rate of 0.5 mL / h using a syringe pump. These A and B liquids were connected to an IMM micromixer (flow path width 45 μm, depth 200 μm), mixed in the internal microspace, and production of a bright magenta dispersion was confirmed from the outlet. As a result of analysis, 2,9-dimethylquinacridone having a purity of 96% or more was produced.

(Comparative Example 6)
To 2.0 g of 2,9-dimethyl-6,13-dihydroquinacridone, 10.0 g of 5N sodium hydroxide aqueous solution and 18 g of polyethylene glycol 400 were added and stirred at room temperature. To the obtained dark green solution, 2.0 mL of 30% by mass hydrogen peroxide was dropped, stirred at 60 ° C. for 1 hour, and cooled to room temperature. As a result of analysis, the conversion was 80%, and 2,9-dimethylquinacridone having a pigment purity of 94% or more was produced.

Example 12 Synthesis of 2,9-dimethylquinacridone by dehydration condensation 2,5-di- (p-toluidino) -terephthalic acid 2.0 g, p-toluenesulfonic acid 0.1 g, ethylene glycol 15 mL, dimethylformamide 20 mL A mixed solution was prepared. A fused silica glass capillary (equivalent diameter 0.20 mm, length 4.0 m) was prepared as a reactor, and 2.5 m was fixed so as to pass through the oil bath. The oil bath was heated to 150 ° C., and this solution was fed into the reactor with a syringe pump at a speed of 1.1 mL / h (residence time 5 minutes). A pigment having a bright magenta color was obtained from the capillary outlet.

(Comparative Example 7)
A solution was prepared by mixing 2.0 g of 2,5-di- (p-toluidino) -terephthalic acid, 0.1 g of p-toluenesulfonic acid, 15 mL of ethylene glycol, and 20 mL of dimethylformamide. The oil bath was heated to 150 ° C. in a 50 mL flask and stirred for 30 minutes. The produced pigment was analyzed, and a little raw material remained.

Example 13 Production of C.I. Pigment Yellow 93 by Amidation Reaction

  0.3 g of phenyl ester derivative (A) and 0.1 g of 3-chloro-2-methylaniline were dissolved in 20 mL of dimethylformamide. A fused silica glass capillary (equivalent diameter 0.53 mm, length 1.5 m) was prepared as a microreactor, and 1.0 m of the capillary was fixed so as to pass through the oil bath. The oil bath was heated to 150 ° C., and this solution was fed into the reactor with a syringe pump at a rate of 2.2 mL / h (residence time 6 minutes). The pigment that emerged from the capillary outlet had a bright yellow color, and as a result of analysis, the purity was 95% or more.

(Comparative Example 8)
0.3 g of phenyl ester derivative (A) and 0.1 g of 3-chloro-2-methylaniline were dissolved in 20 mL of dimethylformamide. The oil bath was heated to 150 ° C. in a 50 mL flask and stirred for 1 hour. Analysis of the resulting pigment revealed that the conversion was 65%, the pigment purity was 93% or less, and a slightly dull yellow color.

Example 14 Production of C.I. Pigment Red 214 by Amidation Reaction

  1.0 g of phenyl ester derivative (B) and 0.2 g of 2,5-dichloro-1,4-phenylenediamine were dissolved in 50 mL of dimethyl sulfoxide. A fused silica glass capillary (equivalent diameter 0.53 mm, length 1.5 m) was prepared as a microreactor, and 1.0 m was fixed so as to pass through the oil bath. The oil bath was heated to 150 ° C., and this solution was fed into the reactor with a syringe pump at a speed of 3.3 mL / h (residence time 4 minutes). The pigment coming out from the capillary outlet had a bright red color, and as a result of analysis, the purity was 96% or more.

Synthesis of fine particles of phthalocyanine pigment (Pigment Blue 16) (Example 15)
A dark green solution prepared by dissolving 2.5 g (0.45 ml) of phthalocyanine disodium salt (Tokyo Chemicals) in dimethyl sulfoxide (DMSO) to 50 ml is a 0.5 μm Teflon (PTFE) microfilter (manufactured by Advantech) ) To obtain an IG solution. Next, a colorless transparent solution prepared by dissolving 0.5 g of polyvinyl pyrrolidone (PVP, K-90 manufactured by Wako Pure Chemical Industries, Ltd., average molecular weight 360,000) in DMSO to 50 ml was prepared from 0.5 μm Teflon (PTFE). The solution was filtered with a microfilter (manufactured by Advantech) to obtain an IH solution. Further, a colorless transparent solution prepared by dissolving 0.5 g (1.17 mmol) of N-oleoyl-N-methyltaurine sodium salt in distilled water to 50 ml was used as a 0.45 μm cellulose ester microfilter (Sartorius) for aqueous solvents. To make an IID solution.
In the reaction apparatus having the cylindrical flow path shown in FIG. 2A having a flow path diameter D of 100 μm, a flow path diameter E of 400 μm, a flow path length G of 20 cm, the flow path length G can be cooled to 5 ° C. The jacket which can circulate the refrigerant was installed. Two Teflon tubes were connected to the introduction port 21 and the introduction port 22 by connectors.
A syringe containing a liquid in which the IG liquid and IH liquid were mixed at a ratio of 1: 2 (volume ratio) was connected to the introduction port 21 and set in a syringe pump. A syringe containing the IID liquid was connected to the inlet 22 and set in a syringe pump. When it is sent out from the inlet 21 at a liquid feeding speed of 1.0 mL / h and from the inlet 22 at 10.0 mL / h, the flow path cooled to 5 ° C. becomes a laminar flow (Reynolds number: about 9.8). A dispersion of phthalocyanine was obtained and collected from the outlet 24. When this was measured using a dynamic light scattering particle size measuring apparatus, a dispersion having a mode diameter of 17.4 nm and an arithmetic standard deviation of 8.6 nm and a small particle size and a very small distribution width could be obtained. .

It is explanatory drawing of the reactor which has a Y-shaped flow path on one side. It is sectional drawing of the II line | wire of FIGS. 1-1. It is explanatory drawing of the reaction apparatus which has the cylindrical tube type flow path which provided the flow path penetrated to one side. It is sectional drawing of the IIa-IIa line | wire of FIG. It is sectional drawing of the IIb-IIb line | wire of FIG. It is explanatory drawing of the reactor which has a Y-shaped channel on both sides It is sectional drawing of the III-III line of FIGS. It is explanatory drawing of the reaction apparatus which has the cylindrical tube type flow path which provided the flow path penetrated on both sides

Explanation of symbols

10, 20, 30, 40 Reactor body 11, 12, 21, 22, 31, 32, 41, 42 Inlet 13, 33 Channel 13a, 13b, 23a, 23b, 33a, 33b, 43a, 43b Inlet channel 13c, 23c, 33c, 43c Reaction flow path 13d, 23d, 33d, 43d Fluid confluence 33e, 43e Fluid diversion point 33f, 33g, 43f, 43g Discharge flow path 14, 24, 34, 35, 44, 45 Discharge port

Claims (15)

  Organic pigment fine particles having a step of circulating a solution of an organic pigment dissolved in an alkaline or acidic aqueous medium as a laminar flow in a channel and changing the hydrogen ion index (pH) of the solution in the laminar flow process Manufacturing method.   The method according to claim 1, wherein the organic pigment solution is alkaline. 3. The production method according to claim 1, wherein the organic pigment solution is a homogeneous solution in which the organic pigment is dissolved in a homogeneous mixed solvent of water and an organic solvent.   The manufacturing method according to claim 1, wherein the flow path has an equivalent diameter of 10 mm or less.   The method according to claim 1, wherein the organic pigment solution contains at least one dispersant.   The production method according to claim 5, wherein at least one of the dispersants is a polymer dispersant.   The production method according to any one of 1 to 6, wherein the organic pigment fine particles are obtained as a dispersion thereof.   The manufacturing method according to claim 1, wherein the flow path has an equivalent diameter of 1 mm or less.   The method according to claim 1, wherein the laminar flow path is a micro reaction field.   10. The organic pigment fine particles obtained by the production method according to claim 1, wherein the mode diameter is 1 μm or less.   A method for producing organic pigment fine particles, wherein a solution containing a reaction component is passed through an apparatus having a flow path having an equivalent diameter of 1 mm or less. The production method according to claim 11, wherein the organic pigment fine particles are a quinacridone pigment represented by the general formula (I).

(Wherein X and Y are independently a fluorine atom, a chlorine atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, and a COOR _a group (where R _a is a hydrogen atom or a carbon atom) And m and n independently represent 0, 1 or 2.)   The production method according to claim 11, wherein the organic pigment fine particles are a condensate of an aryl ester of azocarboxylic acid and an aromatic diamine, or a condensate of a diaryl ester of azodicarboxylic acid and an aromatic amine.   At least one of a solution in which an organic pigment is dissolved and an aqueous medium have a dispersant, and both of them are brought into contact in an apparatus having a flow path having an equivalent diameter of 1 mm or less to make the pigment fine particles. A method for producing a pigment dispersion.   The method according to claim 14, wherein the organic pigment solution is alkaline.

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