JP2007270079A - Ink set for inkjet recording and inkjet recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink set for inkjet recording recording high-quality images excellent in long-term storage stability without color mixture and color bleeding at high density. <P>SOLUTION: The ink set for inkjet recording comprises a first liquid A for at least forming an image and a second liquid B different in composition from the first liquid A, wherein at least one of the liquid A and the liquid B contains organic material particles having an average particle size of 50 nm or less and a coefficient of variation of the particle size of 50%. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ink set for ink jet recording and an ink jet recording method, and more particularly to an ink set for ink jet recording and an ink jet recording method suitable for forming high-quality images at high speed using multiple liquids.

  An ink jet system that discharges ink in droplets from an ink discharge port such as a nozzle is used in many printers because it is small and inexpensive, and can form an image without contact with a print medium. Among these ink jet methods, the piezo ink jet method that ejects ink using deformation of piezoelectric elements and the thermal ink jet method that ejects ink droplets by utilizing the boiling phenomenon of ink due to thermal energy achieve high resolution and high printability. It has the feature of being excellent.

  2. Description of the Related Art Currently, high speed and high image quality when ink is ejected onto a non-water-absorbing recording medium such as plain paper or plastic by an ink jet printer are important issues.

  Ink-jet recording continuously discharges ink (liquid) droplets as droplet n1, droplet n2, droplet n3,..., Droplet nx, and droplets n1 and n2 on a recording medium. , Droplets n3,..., Lines are formed with droplets nx, or images are formed. However, if it takes time to penetrate the droplets after droplet ejection, bleeding tends to occur in the image. In addition, there are practical problems such as mixing between adjacent ink droplets n1 and ink droplets n2 and hindering sharp image formation. When mixing between droplets, adjacent droplets that have been struck are united to cause movement of the droplets, so that they deviate from the landing position, and when drawing thin lines, the line width is uneven. When a colored surface is drawn, color unevenness or the like occurs.

  One of the methods for suppressing image bleeding and non-uniform line width is a method for promoting ink curing. As one of them, a technique for curing and fixing by radiation rather than volatilization of the ink solvent has been proposed. Furthermore, in order to give precision drawing properties, two-component ink is used, and both are reacted on the recording medium. For example, after attaching a liquid having a basic polymer, an anionic dye is contained. A method for recording ink (for example, see Patent Document 1), and a method for applying an ink containing an anionic compound and a coloring material after applying a liquid composition containing a cationic substance (for example, see Patent Document 2) ), A recording method using an ink containing a photocurable resin on one side and a photopolymerization initiator on the other (see, for example, Patent Document 3).

  However, these methods have a certain effect in suppressing blurring of the image, but are insufficient for eliminating the non-uniform line width and color unevenness caused by mixing between droplets. Therefore, there is a concern that the drying speed is slow due to the presence of the dye, and the precipitated dye is likely to be unevenly distributed, resulting in a decrease in image quality.

As a technique related to the above, there is a technique in which a pigment is used as a coloring component and cured and fixed by radiation (for example, see Patent Document 4). Here, after forming a pixel using one of two liquids of an ink containing a monomer to be solidified and an ink containing a pigment dispersion, the pixel is formed at the same point as the image on the other side, and curing is performed with ultraviolet rays, It describes that it is performed using an electron beam or the like.
In addition, an ink composition containing a reactive monomer, a colorant and the like together with water and an aggregating solution containing an aggregating agent that generates an agglomerate are used, and after the aggregating solution is adhered onto a recording medium, the ink composition Has been described (see, for example, Patent Document 5). Furthermore, there is a description that a monomer-containing ink composition is applied after the reaction liquid containing a photopolymerization initiator is applied over the entire surface, and ultraviolet irradiation is performed (for example, see Patent Document 6).

In addition to the above, there is a description relating to ink ejection in two types so as to overlap each other (see, for example, Patent Document 7).
Japanese Unexamined Patent Publication No. 63-60783 JP-A-8-174997 Japanese Patent No. 3478495 Japanese Patent Laid-Open No. 8-21818 JP 2001-348519 A Patent 3642152 JP 2000-135781 A

  However, with only the conventional technique described above, for example, when recording is performed using a non-permeable or slowly permeable recording medium having a low ink absorption rate, adjacent droplets a1 and droplets to obtain a high image density. When a2 is deposited repeatedly, adjacent droplets are mixed on each other when they are present on the medium in a non-dry state, that is, a phenomenon of coalescence of adjacent droplets occurs. It is difficult to sufficiently eliminate uneven line width and mixed colors (color unevenness, etc.).

  Further, in the system using two liquids, liquids having different compositions are mixed on the recording medium. Therefore, when the dispersion is not performed particularly well when a pigment dispersant is used, a shock due to mixing causes a shock at the time of mixing. There is a problem that the dispersion destruction is caused to affect the image density and the transparency of the image is impaired.

The present invention has been made in view of the above, and is an ink jet recording ink set and an ink jet recording method that are excellent in long-term storage stability and can record high-quality images with high density and no color mixing and color bleeding. It is an object to provide this and to achieve the object.
In addition to the above, the present invention further provides an inkjet recording capable of recording an image having a uniform line width while maintaining a dot shape and an image having no stickiness and excellent scratch resistance, light resistance, and ozone resistance. It is another object of the present invention to provide a recording ink set and an ink jet recording method.

Specific means for achieving the above object are as follows.
<1> An ink set for ink-jet recording comprising at least one first liquid A for forming an image and at least one second liquid B having a composition different from that of the first liquid A. Thus, at least one of the liquids A and B is an ink set for ink jet recording containing organic material particles having an average particle size of 50 nm or less and a particle size variation coefficient of 50% or less.
<2> The ink set for ink jet recording according to <1>, wherein the organic material particles are generated by a reprecipitation method.
<3> The organic material particles are mixed with at least three kinds of a solution of an organic material dissolved in a good solvent, a poor solvent of the organic material compatible with the good solvent, and a solution containing a polymer dispersant. The ink set for ink jet recording according to <1> or <2>, wherein the organic material is produced as particles from the mixed solution.
<4> The ink set for ink-jet recording according to any one of <1> to <3>, wherein the organic material is an organic pigment.
<5> The inkjet recording according to any one of <1> to <4>, wherein the liquid B does not contain a colorant or the content of the colorant is less than 1%. It is an ink set.
<6> The ink set for inkjet recording according to any one of <1> to <5>, wherein the liquid A contains a polymerizable or crosslinkable material.
<7> The ink set for inkjet recording according to any one of <1> to <6>, wherein the liquid B further contains a surfactant.

<8> Using the ink set for inkjet recording according to any one of <1> to <7>, the second liquid B is the same as or more than the image formed with the first liquid A This is an ink jet recording method that is applied to a recording medium in a wide range in advance.
<9> The image is formed by ejecting the liquid A as at least a first droplet a1 and a droplet a2 and ejecting the droplet a1 and the droplet a2 with overlapping portions. <8> The inkjet recording method according to <8>.
<10> The inkjet recording method according to <9>, wherein the overlapping ratio in the overlapping portion is 10% or more and 90% or less.
<11> The above <8> to <10>, wherein after the application of the liquid B, the droplet ejection interval until the droplet a1 of the liquid A is ejected is 5 μs or more and 400 milliseconds or less. The inkjet recording method according to any one of the above.
<12> Any one of <8> to <11>, wherein a droplet size of the liquid A including the droplet a1 and the droplet a2 is 0.1 picoliter or more and 100 picoliter or less. The inkjet recording method according to one of the above.
<13> The inkjet recording method according to any one of <8> to <12>, wherein the liquid B is held in a liquid state until the liquid A is ejected.
<14> The liquid A contains a polymerizable or crosslinkable material, and after the droplet A is deposited, the active energy is applied to the image to polymerize or crosslink the polymerizable or crosslinkable material. The inkjet recording method according to any one of <8> to <13>.

According to the present invention, it is possible to provide an ink set for ink jet recording and an ink jet recording method which are excellent in storage stability in a long period of time and can record a high-quality image with high density and no color mixing and color bleeding.
Further, according to the present invention, in addition to the above, it is possible to record an image having a uniform line width while maintaining the dot shape, and an image having no stickiness, excellent scratch resistance, light resistance, and ozone resistance. An ink set for ink jet recording and an ink jet recording method can be provided.

  Hereinafter, the ink set for ink jet recording of the present invention and the ink jet recording method using the ink set will be described in detail.

  The ink set for inkjet recording of the present invention comprises at least one kind of first liquid A for forming an image and at least one kind of second liquid B having a composition different from that of the first liquid A. An organic material particle having an average particle size of 50 nm or less and a particle size variation coefficient of 50% is used for at least one of the first liquid A and the second liquid B.

A droplet a1, a droplet a2,..., And a second liquid B having a composition different from that of the first liquid A are formed on the recording medium from an ink discharge port (head) in the ink jet printer. Are formed by using “organic material particles having an average particle size of 50 nm or less and a coefficient of variation of the particle size of 50%” for the liquid A and / or the liquid B. Because these organic material particles are fine, monodisperse and highly agglomerated even when subjected to external force (shock), they overlap between droplets such as between droplets a1 and a2 to obtain a high image density. When the droplets are ejected so as to have a part, they can effectively avoid the dispersion destruction caused by the shock when the droplets collide and mix, so it is highly transparent at high concentration, and color mixing and color bleeding It is possible to record high-quality images without .
In addition, since it is configured in a two-liquid system of the first liquid A and the second liquid B having different compositions from each other, an image having a uniform line width can be recorded while maintaining the dot shape, and there is no stickiness and scratching. Excellent light resistance and ozone resistance.

  Hereinafter, the first liquid A and the second liquid B constituting the ink set for inkjet recording of the present invention will be described in detail.

  The first liquid A is configured to have at least a composition for forming an image, and the second liquid B is configured to have at least a composition different from that of the first liquid A. B or both liquid A and liquid B contain at least one organic material particle having an average particle size of 50 nm or less and a particle size variation coefficient of 50%.

-Organic material particles-
The organic material particles contained in the liquid A and / or the liquid B constituting the ink set for ink jet recording of the present invention have an average particle size of 50 nm or less and a particle size variation coefficient of 50%. Hereinafter, it is also referred to as “organic material particles according to the present invention”. The organic material particles according to the present invention are finely monodispersed, unlike conventional particles obtained by finely pulverizing a pigment of a certain size with beads or the like, and change in the particle size and monodispersity of the organic particles in a concentrated system. Uniform particles that are small or unchanged, and are difficult to agglomerate even when external shock is applied, resulting in a stable dispersion, resulting in dispersion destruction during droplet ejection during image formation, resulting in a decrease in density It is effective in preventing the deterioration of transparency and the occurrence of color mixing and color bleeding. In particular, it is possible to prevent a decrease in the density of the ink ejected downward when mixing the two liquids ejected onto the recording medium. Therefore, it is possible to record a high-quality image with high density and excellent transparency and color tone.

  The organic material particles according to the present invention have an average particle size of 50 nm or less, preferably 40 nm or less. The lower limit is 10 nm. The average particle size is the size of finely dispersed primary particles, and is obtained by direct observation using a scanning electron microscope S5200 (manufactured by Hitachi, Ltd.). When the average particle size is within the above range, a stable dispersion can be obtained, and dispersion breakage during droplet ejection during image formation is unlikely to occur.

Further, the organic material particles according to the present invention have a particle size variation coefficient of 50% or less and high monodispersity. The coefficient of variation should be as small as possible, preferably 45% or less.
The coefficient of variation of the particle size distribution is the ratio of the standard deviation of the particle size distribution to the average particle size. That is, a value obtained by dividing the standard deviation of the projected area diameter, sphere equivalent diameter, or thickness distribution of the particle by the average value of the projected area diameter, sphere equivalent diameter, or thickness and multiplying by 100 and expressed in%. The particle size distribution may be measured by any known method, but can be obtained by observing and measuring the shape of the particles with an electron micrograph. Specifically, it is calculated | required using scanning electron microscope S5200 [made by Hitachi, Ltd.].

  The organic material particles of the present invention are preferably produced by a reprecipitation method. The reprecipitation method is a method in which an organic material is dissolved in a good solvent and mixed with a poor solvent of the organic material to produce and prepare particles. Among these methods, it is more preferable to use the following method.

The preferred method of reprecipitation is shown below.
The organic material particles according to the present invention are a mixture of at least three kinds of a solution of an organic material dissolved in a good solvent, a poor solvent of the organic material compatible with the good solvent, and a solution containing a polymer dispersant. And it can prepare by producing | generating the said organic material as particle | grains from this liquid mixture. The organic material particles according to the present invention may be crystalline particles, non-crystalline particles, or a mixture thereof.
Hereinafter, the method for preparing organic material particles according to the present invention will be described in detail.

[Materials used as organic material particles]
The organic material forming the organic material particles is not particularly limited as long as the particles can be formed by a reprecipitation method. Organic materials include colored coloring materials and substantially colorless non-coloring materials, such as organic pigments, organic dyes, fullerenes, polydiacetylenes, polyimides and other high molecular compounds, aromatic hydrocarbons or aliphatics. And particles composed of hydrocarbons (eg, aromatic or aliphatic hydrocarbons having orientation, or aromatic or aliphatic hydrocarbons having sublimation properties), organic pigments, organic dyes, or high Molecular compounds are preferred, and organic pigments are particularly preferred. A combination of these may also be used.

  The organic pigment is not limited in hue, for example, perylene, perinone, quinacridone, quinacridonequinone, anthraquinone, anthanthrone, benzimidazolone, disazo condensation, disazo, azo, indanthrone, phthalocyanine, triarylcarbonium , Dioxazine, aminoanthraquinone, diketopyrrolopyrrole, thioindigo, isoindoline, isoindolinone, pyranthrone or isoviolanthrone pigment, or a mixture thereof.

  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);

C. 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 yellow 150 (C.I. No. 48545), 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. And isoviolanthrone pigments such as CI Pigment Violet 31 (60010).
In the present invention, two or more kinds of organic pigments or solid solutions of organic pigments can be used in combination.

  Examples of organic dyes include azo dyes, cyanine dyes, merocyanine dyes, and coumarin dyes. Examples of the polymer compound include polydiacetylene and polyimide.

[Formation of organic material particles]
Next, formation of organic material particles will be described.
The organic material particles (hereinafter also referred to as organic particles) in the organic material particles according to the present invention include an organic material solution obtained by dissolving an organic material in a good solvent, a poor solvent for the organic material, and a polymer dispersant solution. It can be suitably formed by a reprecipitation method in which organic particles are obtained by mixing (hereinafter, the organic particle liquid obtained by the reprecipitation method is referred to as “organic particle reprecipitation liquid”).

-Good solvent for organic particle formation-
First, a good solvent that dissolves the organic material will be described.
The good solvent is not particularly limited as long as it can dissolve the organic material to be used and is compatible with or uniformly mixed with the poor solvent used in the preparation of the organic particles. The solubility of the organic material in a good solvent is such that the solubility of the organic material is preferably 0.2% by mass or more, and more preferably 0.5% by mass or more. This solubility may be the solubility when dissolved in the presence of an acid or alkali. The preferable range of the compatibility or uniform mixing property between the poor solvent and the good solvent is preferably 30% by mass or more, and more preferably 50% by mass or more, with respect to the poor solvent.

Examples of good solvents include aqueous solvents (eg, water, hydrochloric acid, aqueous sodium hydroxide), alcohol solvents, amide solvents, ketone solvents, ether solvents, aromatic solvents, carbon disulfide, and aliphatic solvents. Solvents, nitrile solvents, sulfoxide solvents, halogen solvents, ester solvents, ionic liquids, mixed solvents thereof, and the like, aqueous solvents, alcohol solvents, ester solvents, sulfoxide solvents or amide solvents. Are preferred, aqueous solvents, sulfoxide solvents or amide solvents are more preferred, and sulfoxide solvents or amide solvents are particularly preferred.
Examples of amide solvents include N, N-dimethylformamide, 1-methyl-2-pyrrolidone, 2-pyrrolidinone, 1,3-dimethyl-2-imidazolidinone, 2-pyrrolidinone, ε-caprolactam, formamide, N -Methylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, N-methylpropanamide, hexamethylphosphoric triamide and the like.
Further, the concentration of the organic material solution in which the organic material is dissolved in the good solvent is preferably a saturated concentration of the organic material with respect to the good solvent in the dissolving conditions or a range of about 1/100 of this, depending on the organic material used. However, for example, 0.5 to 12% by mass is preferable, and 2 to 12% by mass is preferable when a higher yield than that expected for an industrial production scale is required.
The conditions for adjusting the organic material solution are not particularly limited, and a range from normal pressure to subcritical and supercritical conditions can be selected. The temperature at normal pressure is preferably −10 to 150 ° C., more preferably −5 to 130 ° C., and particularly preferably 0 to 100 ° C.

  In the present invention, the organic material dissolves uniformly in a good solvent, but it is also preferable that the organic material dissolves in an acidic or alkaline manner. 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.

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

  The amount of the base used is an amount capable of uniformly dissolving the pigment, and is not particularly limited. However, in the case of an inorganic base, it is preferably 1.0 to 30 molar equivalents relative to the organic material, more preferably 1 0.0 to 25 molar equivalents, more preferably 1.0 to 20 molar equivalents. In the case of an organic base, it is preferably 1.0 to 100 molar equivalents, more preferably 5.0 to 100 molar equivalents, still more preferably 20 to 100 molar equivalents relative to the organic material.

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 organic material, and is not particularly limited. Regardless of inorganic acid or organic acid, it is preferably 3 to 500 molar equivalents, more preferably 10 to 500 molar equivalents, still more preferably 30 to 200 molar equivalents relative to the organic material.

  When mixing an alkali or acid with an organic solvent and using it as a good solvent for an organic material, the solvent has a high solubility in some alkali or acid such as water or lower alcohol in order to completely dissolve the alkali or acid. Can be added to the organic solvent. The amount of water or lower alcohol is preferably 50% by mass or less, more preferably 30% by mass or less, based on the total amount of the organic material solution. Specifically, water, methanol, ethanol, n-propanol, isopropanol, butyl alcohol, or the like can be used.

-Poor solvent for organic materials-
Next, the poor solvent of an organic material is demonstrated.
The poor solvent for the organic material is not particularly limited as long as it is compatible with or uniformly mixed with a good solvent for dissolving the organic material. As a poor solvent for the organic material, the solubility of the organic material is preferably 0.02% by mass or less, and more preferably 0.01% by mass or less. This solubility may be the solubility when dissolved in the presence of an acid or alkali. Further, the compatibility or uniform mixing property between the good solvent and the poor solvent is as described in the section of the good solvent.
Examples of the poor solvent include aqueous solvents (for example, water, hydrochloric acid, aqueous sodium hydroxide), alcohol solvents, ketone solvents, ether solvents, aromatic solvents, carbon disulfide, aliphatic solvents, nitriles. Examples thereof include a system solvent, a halogen solvent, an ester solvent, an ionic liquid, a mixed solvent thereof, and the like, and an aqueous solvent, an alcohol solvent, or an ester solvent is preferable. In particular, an aqueous solvent is very preferable for inkjet applications.
Examples of the alcohol solvent include methanol, ethanol, isopropyl alcohol, n-propyl alcohol, 1-methoxy-2-propanol and the like. Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Examples of the ether solvent include dimethyl ether, diethyl ether, tetrahydrofuran and the like. Examples of the aromatic solvent include benzene and toluene. Examples of the aliphatic solvent include hexane. Examples of the nitrile solvent include acetonitrile. Examples of the halogen solvent include dichloromethane, trichloroethylene, and the like. Examples of the ester solvent include ethyl acetate, ethyl lactate, 2- (1-methoxy) propyl acetate and the like. Examples of the ionic liquid include a salt of 1-butyl-3-methylimidazolium and PF ₆ —.

-Dispersant when forming organic particles-
In the preparation of the organic particles, the polymer dispersant is added at the time of forming the organic particles. The molecular weight of the polymer dispersant can be used without limitation as long as it can be uniformly dissolved as a solution, but preferably has a molecular weight of 1,000 to 2,000,000, and 5,000 to 1,000,000. 000 is more preferable, 10,000 to 500,000 is more preferable, and 10,000 to 100,000 is particularly preferable (in the present invention, unless otherwise specified, the molecular weight means a weight average molecular weight. Polymer) The compound is a polydisperse system and does not necessarily have the same molecular weight or particle weight, so when the molecular weight is measured, the value obtained is an average molecular weight that is averaged in some form. That is, (1) number average molecular weight Mn, (2) weight average molecular weight Mw, (3) Z average molecular weight Mz, and a relationship of Mn <Mw <Mz is established. To.).

In the preparation of the organic material particles, the solvent for dissolving the polymer dispersant is not particularly limited as long as the polymer dispersant can be dissolved at a desired concentration. For example, an aqueous solvent (for example, water, hydrochloric acid, water, Sodium oxide aqueous solution), alcohol solvent, ketone solvent, ether solvent, aromatic solvent, carbon disulfide, aliphatic solvent, nitrile solvent, halogen solvent, ester solvent, ionic liquid, and mixtures thereof Examples of the solvent include an aqueous solvent, an alcohol solvent, and an ester solvent.
The concentration of the polymer dispersant solution is appropriately determined depending on the solubility of the polymer dispersant, etc. The amount of the polymer dispersant (the total amount when used in combination with other dispersants) is based on the total amount of the solution. It is preferably 1 to 90% by mass, more preferably 10 to 80% by mass, and particularly preferably 30 to 80% by mass.

Specific examples of the polymer dispersant include, for example, polyvinyl pyrrolidone, polyvinyl alcohol, polyvinyl methyl ether, polyethylene oxide, polyethylene glycol, polypropylene glycol, polyacrylamide, polyethylene imine, vinyl alcohol-vinyl acetate copolymer, polyvinyl alcohol-part. Formalized product, polyvinyl alcohol-partially butyralized product, vinyl pyrrolidone-vinyl acetate copolymer, polyethylene oxide / propylene oxide block copolymer, polyacrylate, polyvinyl sulfate, poly (4-vinylpyridine) salt, polyamide, poly Allylamine salt, condensed naphthalene sulfonate, styrene-acrylate copolymer, styrene-methacrylate copolymer, acrylate-acrylate copolymer , Acrylate-methacrylate copolymer, methacrylate-acrylate copolymer, methacrylate-methacrylate copolymer, styrene-itaconate copolymer, itaconic acid-itaconic acid Examples thereof include a salt copolymer, a vinyl naphthalene-acrylate copolymer, a vinyl naphthalene-methacrylate copolymer, a vinyl naphthalene-itaconate copolymer, a cellulose derivative, and a starch derivative. In addition, natural polymers such as alginate, gelatin, albumin, casein, gum arabic, tonganto gum and lignin sulfonate can also be used. Of these, polyvinylpyrrolidone, polyacrylamide, and polyethyleneimine are preferable. These polymer dispersants can be used alone or in combination of two or more.
In addition to the polymer dispersant, it is also desirable to use an anionic, cationic, amphoteric, nonionic or pigmentary low molecular dispersant in combination. These low molecular weight dispersants can be added to the organic material solution and / or the poor solvent of the organic material. It is also very preferable to add it to the polymer dispersant solution. The dispersant used in combination 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 alone or in combination of two or more.

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

The amphoteric dispersant is a dispersant having both an anion group part in the molecule of the anionic dispersant and a cationic group part in the molecule of the cationic dispersant.
Nonionic dispersants (nonionic surfactants) include polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylamine, Examples thereof include glycerin fatty acid esters. Of these, polyoxyethylene alkylaryl ether is preferable. These nonionic dispersants can be used alone or in combination of two or more.

The pigment-based dispersant is defined as a pigment-based dispersant derived from an organic pigment as a parent substance and 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 a functional group linked to the pigment parent structure via a methylene group, 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. When considering use as a color filter, it is preferable to use an alkali-soluble polymer dispersant. Further, compounds represented by the general formula (I) described in JP-A-2000-239554 are also preferably used.
The amount of the polymer dispersant relative to the organic material (the total amount when combined with other dispersants) is based on 100 parts by mass of the organic material in order to further improve the uniform dispersion and storage stability of the organic particles. The range is preferably 0.1 to 1000 parts by mass, more preferably 1 to 500 parts by mass, and particularly preferably 10 to 250 parts by mass. If the amount is less than 0.1 parts by mass, the dispersion stability of the organic material particles may not be improved.

[Conditions when forming organic particles]
There are no particular limitations on the conditions of the poor solvent when the organic particles are produced, that is, when the organic particles are deposited and formed, and a range from normal pressure to subcritical and supercritical conditions can be selected. The temperature at normal pressure is preferably −30 to 100 ° C., more preferably −10 to 60 ° C., and particularly preferably 0 to 30 ° C.
The mixing method of the organic material solution (a), the poor solvent (b) of the organic material, and the polymer dispersant solution (c) is not particularly limited and may be mixed simultaneously or sequentially. However, it is preferable to add the organic material solution (a) and the polymer dispersant solution (c) continuously to a sufficient amount of the poor solvent (b). More preferably, the molecular dispersant solution (c) is added simultaneously.
When the organic material solution (a) and / or the polymer dispersant solution (c) is added to the poor solvent (b), the poor solvent (b) is preferably in a stirred state. The stirring speed is preferably 100 to 10,000 rpm, more preferably 150 to 8000 rpm, and particularly preferably 200 to 6000 rpm. A pump or the like may be used for the addition, or it may not be used. Moreover, although addition in a liquid or addition outside a liquid may be sufficient, addition in a liquid is more preferable.
The mixing ratio of the organic material solution (a), the poor solvent (b), and the polymer dispersant solution (c) is preferably 1 <b / a <20 and 1 <b / c <100 in volume ratio.
The concentration of the resulting organic particle reprecipitation liquid is not particularly limited as long as it is a range in which organic particles can be generated, but the organic particles are preferably in the range of 10 to 40,000 mg, more preferably 20 to 1000 ml of the dispersion solvent. It is the range of -30000 mg, Most preferably, it is the range of 50-25000 mg.

[Particle size and monodispersity of organic material particles]
Regarding the particle size (average particle size) of the organic material particles, there is a method of expressing the average size of the group by quantifying by a measurement method, but as a commonly used mode diameter, which shows the maximum value of the distribution, There are median diameter corresponding to the median of the integral distribution curve, various average diameters (number average, length average, area average, weight average, volume average, etc.). In the present invention, the average particle size is represented by a number average diameter unless otherwise specified. The particle size of the organic particles (primary particles) is 50 nm or less, preferably 45 nm or less, and more preferably 40 nm or less.

  Further, as an index representing the monodispersity of the particles, the monodispersity of the particles (primary particles) contained in the organic particle dispersion used in the organic particle concentration method, that is, the volume average particle size (Mv) and the number average particle size. The ratio (Mv / Mn) to (Mn) is preferably 1.0 to 2.0, more preferably 1.0 to 1.8, and 1.0 to 1.5. Is particularly preferred.

[Organic particle formation method (manufacturing equipment)]
Specific preferred examples of the manufacturing apparatus used for forming the organic material particles and the particle forming method using the same will be described below. However, the present invention is not construed as being limited by this illustration.

(Organic particle production device example 1)
FIG. 1 is a schematic view of a manufacturing apparatus used as one embodiment in the present invention. In FIG. 1, the organic material solution is continuously supplied into the mixing chamber 13 provided in the container 11 by the supply pipe 14a and the polymer dispersant solution by 14b. Here, the container 11 is filled with the poor solvent 11a, the mixing chamber 13 is provided below the liquid surface of the poor solvent, and the inside thereof is filled with the poor solvent. The bulk poor solvent in the reaction vessel 11 is always convected by the action of stirring in the mixing chamber 13 so as to cross the mixing chamber 13 from below to above (in the direction of the arrow in the figure).

  FIG. 2 is an enlarged partial sectional view schematically showing the mixing chamber 13 in an enlarged manner as one embodiment of the manufacturing apparatus of FIG. The organic material solution is supplied into the mixing chamber 13 from the supply pipe 14a, and the polymer dispersant solution is supplied from 14b. The mixing chamber 13 is formed by a casing 17 made of a rectangular cylinder having a constant cross-sectional area. The upper end of the casing 17 is an open end, and a circular hole 18 is provided at the lower end so that the poor solvent in the mixer 13 is bulk. It is connected to the poor solvent. Here, the organic material solution supply pipe 14 a and the polymer dispersant solution supply pipe 14 b are provided in a wall constituting the lower end of the casing 17 and open toward the circular hole. A stirring blade 12 is provided in the mixer 13, and the stirring blade is attached to a shaft 15 and rotated by a motor (not shown). The rotation of the stirring blade 12 causes the poor solvent to constantly circulate through the circular hole 18 from the lower side to the upper side in the mixer 13.

The stirring blade 12 provided in the mixing chamber 13 must produce a desired mixing strength in the mixing chamber. This mixing strength is presumed to be an important operating factor for the size of the droplet when the organic material solution and the polymer dispersant solution are mixed.
In addition, the stirring blades 12 can be combined with other organic particles to become larger particles when the organic particles generated in the mixing space remain in the mixing chamber 13, or to the organic material solution supplied to the mixing chamber 13. It is preferable to select one that has the ability to quickly draw out the generated organic particles and quickly discharge them out of the mixing chamber 13 so that the particles are not exposed and become large particles.
As long as the said objective is achieved as the stirring blade 12, what kind of thing may be sufficient, for example, a turbine type, a fan turbine type, etc. may be used.
Moreover, it is preferable that the casing 17 is comprised by the square cylinder as mentioned above. By doing in this way, the angle of the casing 17 disturbs the flow created by the stirring blade 12, and the mixing effect can be further enhanced without requiring an additional material such as a baffle plate.

  FIG. 3 is an enlarged partial cross-sectional view of a mixer having two stirring blades (mixing stirring blade 19a and discharging stirring blade 19b) in the mixing chamber as another embodiment of the manufacturing apparatus of FIG. By providing two stirring blades in this way, the ability to control the mixing strength and the ability to discharge the generated organic particles to the outside of the mixer can be independently selected. It is possible to operate by setting the amount to a desired value independently.

(Organic particle production device example 2)
FIG. 4 is a cross-sectional view schematically showing another embodiment of a production apparatus used for producing organic material particles according to the present invention. In FIG. 4, the organic material solution and the poor solvent are continuously supplied into the agitation tank 21a through the supply pipes 24a and 24b, respectively. At the same time, the polymer dispersant solution is continuously supplied into the stirring tank 21a from the other supply pipe 24c. The organic particles generated in the agitation tank 21a stay in the agitation tank 21a, so that they are combined with other organic particles to become larger particles or exposed to the supplied organic material solution to become large particles. Thus, the generated organic particle re-precipitation liquid is quickly drawn out from the discharge pipe 23 so that the giant particles are not generated.

FIG. 5 is a sectional view schematically showing still another embodiment of the apparatus used for producing the organic particles of the present invention. In the manufacturing apparatus of FIG. 5, the stirring device 50 has finished the two liquid supply ports 32 and 33 through which the organic material solution and the poor solvent flow, the supply port 31 through which the polymer material solution flows, and the stirring process, respectively. A cylindrical stirring tank 38 having a liquid discharge port 36 for discharging the mixed liquid, and a stirring means for controlling the stirring state of the liquid in the stirring tank 38 by being driven to rotate in the stirring tank 38. A pair of stirring blades 41 and 42 is provided.
The agitation tank 38 includes a cylindrical tank body 39 whose central axis is directed in the vertical direction, and a seal plate 40 serving as a tank wall that closes the upper and lower opening ends of the tank body 39. The agitation tank 38 and the tank body 39 are made of a nonmagnetic material having excellent magnetic permeability. The two liquid supply ports 32 and 33 are provided at positions near the lower end of the tank body 39, and the liquid discharge port 36 is provided at a position near the upper end of the tank body 39.

  Then, the pair of stirring blades 41 and 42 are disposed apart from the upper and lower ends facing each other in the stirring tank 38 and are driven to rotate in opposite directions. Each of the stirring blades 41 and 42 constitutes a magnetic coupling C with an external magnet 46 disposed outside the tank wall (seal plate 40) in which the respective stirring blades 41 and 42 are close to each other. That is, the stirring blades 41 and 42 are coupled to the respective external magnets 46 by magnetic force, and are rotated in opposite directions by driving the external magnets 46 with independent motors 48 and 49. .

The pair of stirring blades 41 and 42 disposed opposite to each other in the tank 38 allow the stirring flows having different directions to enter the tank 38 as indicated by the wavy arrow (X) and the solid line arrow (Y) in FIG. Form. And since the stirring flow which each stirring blade 41 and 42 forms differs in the flow direction, it collides with each other, the high speed turbulent flow which accelerates | stimulates stirring in the tank 38 is produced | generated in the tank 38, Is prevented from becoming steady, and even when the rotation speed of the stirring blades 41 and 42 is increased, the formation of a cavity around the rotation axis of the stirring blades 41 and 42 is prevented, and at the same time, the stirring action is sufficiently achieved. Therefore, it is possible to prevent a disadvantage that a steady flow that flows in the tank 38 along the inner peripheral surface of the stirring tank 38 is formed. Therefore, the processing speed can be easily improved by increasing the speed of rotation of the stirring blades 41 and 42. Further, at this time, the liquid flow in the tank 38 becomes steady, and liquid with insufficient stirring and mixing is obtained. It is possible to prevent discharge and prevent deterioration in processing quality.
In addition, since the stirring blades 41 and 42 in the stirring tank 38 are connected to the motors 48 and 49 disposed outside the stirring tank 38 by the magnetic coupling C, the rotating shaft is attached to the tank wall of the stirring tank 38. Since there is no need for insertion, the stirring tank 38 can be made into a closed container structure without the insertion part of the rotating shaft, so that leakage of the stirred and mixed liquid to the outside of the tank can be prevented and at the same time the lubricating liquid (seal for the rotating shaft) It is possible to prevent deterioration in processing quality due to mixing of the liquid) into the liquid in the tank 38 as an impurity.

In the production of the organic particles according to the present invention, the organic particles can be produced not only in a batch method but also in a continuous flow method by using a production apparatus having these configurations, and can be used for mass production. Further, the generated organic particle reprecipitation liquid is quickly discharged, so that the ratio of the organic material solution and the poor solvent liquid supplied into the stirring tank can be made constant at all times. For this reason, it becomes possible to make the solubility of the organic material of a dispersion liquid constant from the time of manufacture start to the end of manufacture, and it is possible to manufacture monodisperse organic particles stably.
Furthermore, the liquid flow in the tank becomes steady and prevents the mixed liquid with insufficient stirring and mixing from being discharged, and the lubricating liquid (seal liquid) for the rotating shaft is mixed into the liquid in the tank as an impurity. By preventing this, monodispersed organic particles can be more stably produced.

[Concentration of organic particle reprecipitation solution]
In the present invention, by desalting and concentrating the organic particle reprecipitation liquid, it is possible to produce an organic particle dispersion composition that can be used as a suitable ink jet recording ink on an industrial scale.
Hereinafter, a method for concentrating the dispersion will be described.
The concentration method is not particularly limited as long as the organic particle liquid can be concentrated. For example, (i) a method of performing desalting and concentration by an ultrafiltration method, (ii) a concentration extraction method (in combination with filter filtration as necessary) ) Method of concentrating, (iii) Method of precipitating organic particles by centrifugation and concentrating, (iv) Method of drying (Method of concentrating by sublimating solvent by vacuum freeze-drying, Drying solvent by heating or reduced pressure) The method of concentrating etc. is preferable, and these combinations etc. are also used preferably. The concentration of the concentrated organic particle liquid (hereinafter also referred to as “concentrated organic particle liquid”) is appropriately determined according to the application, redispersion conditions, etc. It is preferably 1 to 100% by mass, more preferably 5 to 100% by mass, and particularly preferably 10 to 100% by mass.

  In the present invention, the organic particles in the liquid as a concentrated organic particle liquid can be obtained in a dispersed state without agglomeration, and an organic particle dispersion composition can be obtained. That is, reaggregation can be suppressed by mixing the polymer dispersant solution separately from the organic material solution and the poor solvent of the organic material during particle formation. Furthermore, thickening of the organic material solution is very effective for facilitating the concentration process with a view to industrial production scale, but even in such a case, the polymer dispersant is used as the organic material solution. By coexisting and concentrating inside, an undesirable change in particle size can be suppressed. The change in the particle size due to aggregation before and after concentration depends on the organic material used, but when not aggregated, the particle size change rate (the value obtained by subtracting 1 from the value obtained by dividing the particle size after concentration by the particle size before concentration) ), It is preferably 20% or less, and more preferably 10% or less.

(I) Ultrafiltration method For ultrafiltration, for example, a method used for desalting / concentration of a silver halide emulsion can be applied. Research Disclosure No. 10208 (1972), No. 13 122 (1975) and No. 16 351 (1977) are known. The pressure difference and flow rate that are important as operating conditions can be selected with reference to the characteristic curve described in Haruhiko Oya's “Membrane Utilization Technology Handbook” Koshobo Publishing (1978), p275. In order to process the particles, it is necessary to find an optimum condition in order to suppress the aggregation of particles. In addition, there are two methods for replenishing a solvent that is lost due to membrane permeation: a constant volume method in which the solvent is continuously added and a batch method in which the solvent is intermittently added, but the desalting time is relatively short. The formula is preferred. As the solvent to be replenished, pure water obtained by ion exchange or distillation is used. However, a dispersant, a poor solvent for the dispersant may be mixed in pure water, or the organic particle dispersion composition may be directly mixed. It may be added.

  FIG. 6 shows a configuration example of an apparatus for performing ultrafiltration. As shown in FIG. 6, this apparatus has a tank 81 for storing the organic particle reprecipitation liquid, a circulation pump 82 for circulating the organic particle reprecipitation liquid in the tank 81, and a dispersion introduced by the circulation pump 82. It has an ultrafiltration module 83 that removes by-product inorganic salts in the product as permeated water. The dispersion from which the permeated water has been separated is returned to the tank 81 again, and the same operation is repeated until the predetermined purpose of removing the by-product inorganic salt is achieved. Further, this apparatus is provided with a replenishment pure water measurement flow meter 84 used to replenish a certain amount of solvent lost by permeate as pure water, and is used to determine the replenishment amount of pure water. A permeated water flow meter 85 is installed. Further, a reverse cleaning pump 86 for introducing water for diluting the permeated water is installed.

As for ultrafiltration membranes, flat plate type, spiral type, cylindrical type, hollow fiber type, hollow fiber type, etc., already incorporated as modules, include Asahi Kasei Co., Ltd., Daicel Chemical Co., Ltd., Toray Co., Ltd., and Nitto Co., Ltd. Although it is commercially available from Denko etc., a spiral type or a hollow fiber type is preferred from the viewpoint of the total membrane area and detergency. In addition, the molecular weight cut off as an index of the threshold value of the component that can permeate the membrane needs to be determined from the molecular weight of the dispersant used, but preferably 5,000 or more and 50,000 or less. More preferably from 5,000 to 15,000.

(Ii) Concentrated Extraction Method In the concentrated extraction method, an extraction solvent is added to and mixed with the organic particle reprecipitation liquid, and the organic particles are concentrated and extracted into the extraction solvent phase (the concentrated organic solution is referred to as “concentrated extract solution”). ”,“ Organic Particle Concentrated Extract ”, etc.), and a method of concentrating the concentrated extract by filtering through a filter or the like as necessary.
The extraction solvent to be used is not particularly limited, but does not substantially mix with the dispersion solvent of the organic particle reprecipitation liquid (for example, an aqueous solvent). The amount of dissolution is preferably 50% by mass or less, more preferably 30% by mass or less), and it is preferably a solvent that forms an interface when allowed to stand after mixing. In addition, the extraction solvent is preferably a solvent that generates weak agglomeration in which organic particles can be re-dispersed in the extraction solvent (re-dispersion is possible without applying high shearing force such as milling or high-speed stirring). . In such a state, it is possible to easily remove the dispersion solvent such as water by filter filtration while wetting the target organic particles with the extraction solvent without causing strong aggregation that changes the particle size. Is preferable.
The extraction solvent is preferably an ester solvent, an alcohol solvent, an aromatic solvent or an aliphatic solvent, more preferably an ester solvent, an aromatic solvent or an aliphatic solvent, and particularly preferably an ester solvent.
Examples of the ester solvent include 2- (1-methoxy) propyl acetate, ethyl acetate, and ethyl lactate. Examples of the alcohol solvent include n-butanol and isobutanol. Examples of the aromatic solvent include benzene, toluene, xylene and the like. Examples of the aliphatic solvent include n-hexane and cyclohexane. Further, the extraction solvent may be a pure solvent based on the above preferred solvent or a mixed solvent composed of a plurality of solvents.

The amount of the extraction solvent is not particularly limited as long as the organic particles can be extracted, but is preferably smaller than the organic particle reprecipitation liquid in consideration of concentration and extraction. When this is represented by volume ratio, when the organic particle reprecipitation liquid is 100, the added extraction solvent is preferably in the range of 1 to 100, more preferably in the range of 10 to 90, and 20 to 80. The range of is particularly preferable. If it is too much, it will take a lot of time for concentration, and if it is too little, extraction will be insufficient and particles will remain in the dispersion solvent.
After adding the extraction solvent, it is preferable to stir and mix so as to be in sufficient contact with the dispersion. Conventional methods can be used for stirring and mixing. Although there is no restriction | limiting in particular in the temperature when adding and mixing an extraction solvent, It is preferable that it is 1-100 degreeC, and it is more preferable that it is 5-60 degreeC. Any device may be used for adding and mixing the extraction solvent as long as each step can be preferably performed. For example, a separation funnel type device can be used.

  According to the concentration extraction method, organic particles can be efficiently concentrated from the organic particle reprecipitation liquid. Regarding the concentration ratio, for example, the concentration in the organic particle liquid after concentration can be preferably concentrated to about 100 to 1000 times, more preferably about 500 to 1000 times. Furthermore, almost no organic particles remain in the dispersion solvent left after extraction of the organic particles, and a high extraction rate can be achieved.

  In order to separate the organic solvent reprecipitation dispersion solvent and the concentrated extract, it is preferable to filter. As the filter filtration apparatus, for example, an apparatus such as pressure filtration can be used. Preferred filters include nanofilters and ultrafilters. It is preferable to remove the remaining dispersion solvent by filtering and further concentrate the organic particles in the concentrated extract.

(Iii) Centrifugation method The centrifuge used for concentration of organic particles by centrifugation can be any device as long as the organic particles in the organic particle reprecipitation liquid (or organic particle concentrated extract) can be precipitated. Also good. As a centrifuge, for example, in addition to a general-purpose device, a device with a skimming function (a function of sucking the supernatant layer during rotation and discharging it out of the system) or continuous centrifugation for continuously discharging solid matter Machine.
Centrifugation conditions are preferably 50 to 10000, more preferably 100 to 8000, and particularly preferably 150 to 6000 in terms of centrifugal force (a value representing how many times the gravitational acceleration is applied). Although the temperature at the time of centrifugation is based on the solvent seed | species of a dispersion liquid, -10-80 degreeC is preferable, -5-70 degreeC is more preferable, 0-60 degreeC is especially preferable.

(Iv) Drying method and reduced pressure drying method The apparatus used for concentration of organic particles by reduced pressure drying is not particularly limited as long as the solvent of the organic particle reprecipitation liquid (or the organic particle concentrated extract) can be evaporated. For example, a general-purpose vacuum dryer and a rotary pump, an apparatus that can be heated and reduced in pressure while stirring the liquid, and an apparatus that can be continuously dried by passing the liquid through a heated and reduced pressure tube.
The heating and drying temperature is preferably 30 to 230 ° C, more preferably 35 to 200 ° C, and particularly preferably 40 to 180 ° C. The pressure during decompression is preferably 100 to 100,000 Pa, more preferably 300 to 90,000 Pa, and particularly preferably 500 to 80,000 Pa.
If concentrated by a reduced pressure drying method, the organic particles can be efficiently concentrated from the organic particle reprecipitation liquid. Regarding the concentration ratio, for example, when the density of the organic particles in the organic particle reprecipitation liquid as a raw material is 1, The density in the concentrated organic particle liquid can be preferably concentrated to about 100 to 3000 times, more preferably about 500 to 2000 times.

Freeze-drying method The freeze-drying method is not particularly limited, and examples thereof include a refrigerant direct expansion method, an overlapping freezing method, a heat medium circulation method, a triple heat exchange method, and an indirect heating freezing method, preferably a refrigerant direct expansion method Indirect heating freezing method, more preferably indirect heating freezing method is used. In any method, it is preferable to perform freeze-drying after preliminary freezing. The pre-freezing conditions are not particularly limited, but it is necessary that the sample to be freeze-dried is completely frozen.
Indirect heating freezing equipment includes small freeze dryer, FTS freeze dryer, LYOVAC freeze dryer, experimental freeze dryer, research freeze dryer, triple heat exchange vacuum freeze dryer, monocooling freeze dryer , HULL freeze dryers, preferably small freeze dryers, laboratory freeze dryers, research freeze dryers, monocooling freeze dryers, more preferably small freeze dryers, monocooling freeze dryers Should be used.
Although the temperature of freeze-drying is not specifically limited, For example, it is -190--4 degreeC, Preferably it is -120--20 degreeC, More preferably, it is about -80--60 degreeC. The pressure of lyophilization is not particularly limited, and can be appropriately selected by those skilled in the art. For example, the pressure may be 0.1 to 35 Pa, preferably 1 to 15 Pa, and more preferably about 5 to 10 Pa. The freeze-drying time is, for example, 2 to 48 hours, preferably 6 to 36 hours, and more preferably about 16 to 26 hours. However, these conditions can be appropriately selected by those skilled in the art. For lyophilization methods, for example, Formulation Machine Technology Handbook: Formulation Machine Technology Study Group, Jinjinshokan, p.120-129 (September 2000); Vacuum Handbook: Nippon Vacuum Technology Co., Ltd., Ohm, p. .328-331 (1992); Journal of the Research Group on Freezing and Drying: Koji Ito et al., No. 15, p. 82 (1965) can be referred to.

  The organic material particles are preferably a composition from which unnecessary ions are removed. The ions to be removed are not particularly limited, but it is preferable to remove ions having a small molecular weight such as sodium (Na), potassium (K), calcium (Ca), chlorine (Cl) and the like. For example, in a color filter application, if there are many ions having a small molecular weight and easy movement, a necessary voltage cannot be maintained, which is an obstacle. The total amount of ions after removal is preferably 1% by mass or less, more preferably 0.1% by mass or less, and particularly preferably 0.01% by mass or less with respect to the organic material. Unnecessary ions can be removed using, for example, the aforementioned ultrafiltration device.

[Dispersion of concentrated organic particle liquid]
In the present invention, the concentrated organic particles can be finely dispersed again in a suitable solvent in accordance with the ink for ink jet recording to obtain an organic particle dispersion composition (in the present invention, the fine dispersion is a dispersion liquid). This is to increase the degree of dispersion by deaggregating the particles inside.)
As described above in the section of the concentrated extraction method, in the organic particle concentrated extract, the organic particles may be aggregated together with the concentration in order to enable rapid filter filtration. Further, in the centrifugal separation method or the drying method, similarly, concentrated organic particles may be aggregated.

As a method for dispersing such agglomerated particles (in the present invention, agglomerated particles are particles in which particles such as agglomerates are gathered by a secondary force), for example, a dispersion method using ultrasonic waves or a physical method is used. A method of adding energy can be used.
The ultrasonic irradiation device used preferably has a function capable of applying an ultrasonic wave of 10 kHz or higher, and examples thereof include an ultrasonic homogenizer and an ultrasonic cleaner. When the liquid temperature rises during ultrasonic irradiation, thermal aggregation of particles occurs, so the liquid temperature is preferably 1 to 100 ° C, more preferably 5 to 60 ° C. The temperature control method can be performed by controlling the temperature of the dispersion, controlling the temperature of the temperature adjusting layer that controls the temperature of the dispersion, or the like.
There are no particular limitations on the disperser used when dispersing the concentrated organic particles by applying physical energy. Examples include a disperser.
It is also preferable to use the dispersant shown in the section [Dispersant for forming organic particles] as a dispersant used for forming organic particles during redispersion.

According to the method described above, the organic particles (primary particles) after redispersion can be made into finely dispersed particles, and can be obtained as nanoparticles having an average particle size of 50 nm or less.
In the present invention, the organic material particles according to the present invention can be used in the form of a dispersion.

Only one type of “organic material particles having an average particle size of 50 nm or less and a coefficient of variation in particle size of 50%” may be added to the ink set for inkjet recording of the present invention. You may use together.
The content of “organic material particles having an average particle size of 50 nm or less and a coefficient of variation in particle size of 50%” in each of liquid A and / or liquid B constituting the ink set for inkjet recording is 1-50 mass% of mass is preferable, 1.5-30 mass% is more preferable, and 2-20 mass% is still more preferable. When the content is within the above range, a desired hue, coloring density, and clear color tone can be obtained while maintaining dispersibility and stability.

  In the present invention, at least one of the first liquid A and the second liquid B contains the organic material particles according to the present invention. Preferably, the first liquid A is the organic material particles according to the present invention. As a preferred embodiment, the second liquid B contains a colored coloring material, and the second liquid B does not contain a coloring material or the content of the coloring material is less than 1%.

-Polymerizable or crosslinkable material-
The first liquid A and the second liquid B can be suitably configured using at least one kind of polymerizable or crosslinkable material for forming an image, and preferably used for at least the first liquid A. Composed. The polymerizable or crosslinkable material has a function of causing a polymerization or crosslinking reaction by an initiating species such as a radical generated from a polymerization initiator described later, and curing.

  As the polymerizable or crosslinkable material, a known polymerizable or crosslinkable material such as a radical polymerization reaction, a cationic polymerization reaction, or a dimerization reaction can be applied. Addition polymerizable compound having at least one ethylenically unsaturated double bond, epoxy compound, oxetane compound, oxirane compound, polymer compound having maleimide group in side chain, photodimerization adjacent to aromatic nucleus is possible Cinnamyl group having an unsaturated double bond, a polymer compound having a cinnamylidene group or a chalcone group in the side chain, and the like, more preferably an addition polymerizable compound having at least one ethylenically unsaturated double bond, It is particularly preferable that the compound is selected from compounds having at least one ethylenically unsaturated bond, more preferably two or more (monofunctional or polyfunctional compound). Specifically, it can be appropriately selected from those widely known in the industrial field according to the present invention, for example, monomers, prepolymers, that is, dimers, trimers and oligomers, or mixtures thereof, and Those having a chemical form such as a copolymer of

  In particular, various known polymerizable monomers known as cationic polymerizable monomers and radical polymerizable monomers are preferable, and specifically, acryloyl group, methacryloyl group, allyl group, vinyl group, internal double bond group in the molecule. (Maleic acid, etc.) and the like, and those having an epoxy group, oxetanyl group, etc. are preferable, and among them, a compound having an acryloyl group, a methacryloyl group, an epoxy group, or an oxetanyl group is preferable in that a curing reaction can be caused with low energy .

  Examples of the polyfunctional compound include a vinyl group-containing aromatic compound, an (meth) acrylate that is an ester of a divalent or higher alcohol and (meth) acrylic acid, an amide of a divalent or higher amine and (meth) acrylic acid. It can be obtained by combining (meth) acrylamide, polyester (meth) acrylate obtained by introducing (meth) acrylic acid into polycaprolactone, ester obtained by combining polybasic acid and dihydric alcohol, or coupling of alkylene oxide and polyhydric alcohol. Polyether (meth) acrylate in which (meth) acrylic acid is introduced into ether, (meth) acrylic acid is introduced into epoxy resin, or epoxy (meth) obtained by reacting a bivalent or higher alcohol with an epoxy-containing monomer Acrylate, urethane acrylate with urethane bond, amino resin Relate, acrylic resin acrylate, alkyd resin acrylate, spirane resin acrylate, silicone resin acrylate, reaction product of unsaturated polyester and photopolymerizable monomer, reaction product of waxes and polymerizable monomer, and the like. .

Among them, (meth) acrylate, polyester (meth) acrylate, polyether (meth) acrylate, epoxy acrylate, urethane acrylate, acrylic resin acrylate, silicone resin acrylate, reaction product of unsaturated polyester and the photopolymerizable monomer are preferable. Acrylate, polyester acrylate, polyether acrylate, epoxy acrylate, and urethane acrylate are particularly preferable.
In addition, in this specification, (meth) acrylic acid shows that it can take both acrylic acid and methacrylic acid.

  Specific examples of the polyfunctional compound include divinylbenzene, 1,3-butanediol diacrylate, 1,6-hexanediol diacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, dipentaerythritol hexaacrylate, 1, 6-acryloylaminohexane, hydroxypivalate ester neopentyl glycol diacrylate, polyester acrylate having a (meth) acryloyl group at the molecular chain end of a polyester having a molecular weight of 500 to 30,000 consisting of a dibasic acid and a dihydric alcohol, polyethylene glycol di An acrylate, an epoxy acrylate having a molecular weight of 450 to 30,000 having a bisphenol (A or S, F) skeleton, and a skeleton of a phenol novolac resin Epoxy acrylates amount from 600 to 30,000, the reaction product of a polyvalent isocyanate and a hydroxyl group (meth) acrylate monomer having a molecular weight of 350 to 30,000, and urethane modified products having urethane bonds and the like in the molecule.

Examples of monofunctional compounds include (meth) acrylate, styrene, acrylamide, vinyl group-containing monomers (vinyl esters, vinyl ethers, N-vinylamide, etc.), (meth) acrylic acid, and the like. , Acrylamide, vinyl esters and vinyl ethers are preferable, and (meth) acrylate and acrylamide are particularly preferable.
The polymerizable compound may be unsubstituted or may have a substituent, and examples of the substituent that can be introduced include a halogen atom, a hydroxyl group, an amide group, and a carboxylic acid group.

  Specific examples of the monofunctional compound include hydroxyethyl acrylate, glycidyl acrylate, tetrahydrofurfuryl acrylate, dicyclopentenyl acrylate, 2-acryloyloxyethyl phosphate, allyl acrylate, N, N-dimethylaminoethyl acrylate, N, N- Dimethylacrylamide, N, N-diethylaminopropylacrylamide, N-butoxymethylacrylamide, acryloylmorpholine, 2-hydroxyethyl vinyl ether, N-vinylformamide, N-vinylacetamide, 2-cyclohexylcarbamoyloxyethyl acrylate, polybutyl acrylate moiety on ester An acrylate having a polydimethylsiloxane moiety in an ester

  Furthermore, examples of the cation polymerizable monomer include JP-A-6-9714, JP-A-2001-31892, JP-A-2001-40068, JP-A-2001-55507, JP-A-2001-310938, JP-A-2001-310937, and JP-A-2001-220526. Epoxy compounds, vinyl ether compounds, oxetane compounds and the like described in each publication are suitable.

Examples of the epoxy compound include aromatic epoxides and alicyclic epoxides.
Examples of monofunctional epoxy compounds include phenyl glycidyl ether, p-tert-butylphenyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, allyl glycidyl ether, 1,2-butylene oxide, 1,3-butadiene monooxide 1,2-epoxydodecane, epichlorohydrin, 1,2-epoxydecane, styrene oxide, cyclohexene oxide, 3-methacryloyloxymethylcyclohexene oxide, 3-acryloyloxymethylcyclohexene oxide, 3-vinylcyclohexene oxide, etc. It is done.

Examples of polyfunctional epoxy compounds include bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, brominated bisphenol A diglycidyl ether, brominated bisphenol F diglycidyl ether, brominated bisphenol S diglycidyl ether Epoxy novolac resin, hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diglycidyl ether, 3,4-epoxycyclohexylmethyl-3 ', 4'-epoxycyclohexanecarboxylate, 2- (3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexane-meta-dioxane, bis (3,4-epoxycyclohexylmethyl Adipate, vinylcyclohexene oxide, 4-vinylepoxycyclohexane, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, 3,4-epoxy-6-methylcyclohexyl-3 ′, 4′-epoxy-6′- Methylcyclohexanecarboxylate, methylenebis (3,4-epoxycyclohexane), dicyclopentadiene diepoxide, di (3,4-epoxycyclohexylmethyl) ether of ethylene glycol, ethylenebis (3,4-epoxycyclohexanecarboxylate), epoxy Dioctyl hexahydrophthalate, di-2-ethylhexyl epoxyhexahydrophthalate, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol Liglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ethers, 1,1,3-tetradecadiene dioxide, limonene dioxide, 1,2,7,8-diepoxy Examples include octane and 1,2,5,6-diepoxycyclooctane.
Among these epoxy compounds, aromatic epoxides and alicyclic epoxides are preferable from the viewpoint of excellent curing speed, and alicyclic epoxides are particularly preferable.

  Examples of monofunctional vinyl ethers include methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, n-butyl vinyl ether, t-butyl vinyl ether, 2-ethylhexyl vinyl ether, n-nonyl vinyl ether, lauryl vinyl ether, cyclohexyl vinyl ether, cyclohexyl methyl vinyl ether, 4-methyl Cyclohexyl methyl vinyl ether, benzyl vinyl ether, dicyclopentenyl vinyl ether, 2-dicyclopentenoxyethyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, butoxyethyl vinyl ether, methoxyethoxyethyl vinyl ether, ethoxyethoxyethyl vinyl ether, methoxypolyethylene glycol vinyl ether, Trahydrofurfuryl vinyl ether, 2-hydroxyethyl vinyl ether, 2-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, 4-hydroxymethylcyclohexyl methyl vinyl ether, diethylene glycol monovinyl ether, polyethylene glycol vinyl ether, chloroethyl vinyl ether, chlorobutyl vinyl ether, chloroethoxy Examples include ethyl vinyl ether, phenyl ethyl vinyl ether, phenoxy polyethylene glycol vinyl ether, and the like.

Examples of polyfunctional vinyl ethers include ethylene glycol divinyl ether, diethylene glycol divinyl ether, polyethylene glycol divinyl ether, propylene glycol divinyl ether, butylene glycol divinyl ether, hexanediol divinyl ether, bisphenol A alkylene oxide divinyl ether, bisphenol F alkylene oxide. Divinyl ethers such as divinyl ether; trimethylolethane trivinyl ether, trimethylolpropane trivinyl ether, ditrimethylolpropane tetravinyl ether, glycerin trivinyl ether, pentaerythritol tetravinyl ether, dipentaerythritol pentavinyl ether, dipentaerythritol hexa Nyl ether, ethylene oxide-added trimethylolpropane trivinyl ether, propylene oxide-added trimethylolpropane trivinyl ether, ethylene oxide-added ditrimethylolpropane tetravinyl ether, propylene oxide-added ditrimethylolpropane tetravinyl ether, ethylene oxide-added pentaerythritol tetravinyl ether, propylene oxide-added pentane And polyfunctional vinyl ethers such as erythritol tetravinyl ether, ethylene oxide-added dipentaerythritol hexavinyl ether, and propylene oxide-added dipentaerythritol hexavinyl ether.
As the vinyl ether compound, a di- or trivinyl ether compound is preferable from the viewpoints of curability, adhesion to a recording medium, surface hardness of the formed image, and the like, and a divinyl ether compound is particularly preferable.

The oxetane compound refers to a compound having an oxetane ring, and a known oxetane compound is arbitrarily selected and used as described in JP-A Nos. 2001-220526, 2001-310937, and 2003-341217. it can.
As the compound having an oxetane ring, a compound having 1 to 4 oxetane rings in its structure is preferable. By using such a compound, it becomes easy to maintain the viscosity of the ink composition in a good handling property range, and it is possible to obtain high adhesion of the cured ink to the recording medium. .

  Examples of monofunctional oxetanes include 3-ethyl-3-hydroxymethyloxetane, 3- (meth) allyloxymethyl-3-ethyloxetane, (3-ethyl-3-oxetanylmethoxy) methylbenzene, 4-fluoro- [ 1- (3-ethyl-3-oxetanylmethoxy) methyl] benzene, 4-methoxy- [1- (3-ethyl-3-oxetanylmethoxy) methyl] benzene, [1- (3-ethyl-3-oxetanylmethoxy) Ethyl] phenyl ether, isobutoxymethyl (3-ethyl-3-oxetanylmethyl) ether, isobornyloxyethyl (3-ethyl-3-oxetanylmethyl) ether, isobornyl (3-ethyl-3-oxetanylmethyl) ether, 2-Ethylhexyl (3-ethyl-3-oxetanylmethyl) Ether, ethyl diethylene glycol (3-ethyl-3-oxetanylmethyl) ether, dicyclopentadiene (3-ethyl-3-oxetanylmethyl) ether, dicyclopentenyloxyethyl (3-ethyl-3-oxetanylmethyl) ether, dicyclo Pentenyl (3-ethyl-3-oxetanylmethyl) ether, tetrahydrofurfuryl (3-ethyl-3-oxetanylmethyl) ether, tetrabromophenyl (3-ethyl-3-oxetanylmethyl) ether, 2-tetrabromophenoxyethyl ( 3-ethyl-3-oxetanylmethyl) ether, tribromophenyl (3-ethyl-3-oxetanylmethyl) ether, 2-tribromophenoxyethyl (3-ethyl-3-oxetanylmethyl) ether, 2-hydride Xylethyl (3-ethyl-3-oxetanylmethyl) ether, 2-hydroxypropyl (3-ethyl-3-oxetanylmethyl) ether, butoxyethyl (3-ethyl-3-oxetanylmethyl) ether, pentachlorophenyl (3-ethyl- 3-oxetanylmethyl) ether, pentabromophenyl (3-ethyl-3-oxetanylmethyl) ether, bornyl (3-ethyl-3-oxetanylmethyl) ether, and the like.

  Examples of polyfunctional oxetanes include 3,7-bis (3-oxetanyl) -5-oxa-nonane, 3,3 ′-(1,3- (2-methylenyl) propanediylbis (oxymethylene)) bis- (3-ethyloxetane), 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, 1,2-bis [(3-ethyl-3-oxetanylmethoxy) methyl] ethane, 1,3 -Bis [(3-ethyl-3-oxetanylmethoxy) methyl] propane, ethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, dicyclopentenylbis (3-ethyl-3-oxetanylmethyl) ether, triethylene Glycol bis (3-ethyl-3-oxetanylmethyl) ether, tetraethylene glycol bis (3-ethyl-3-io Xetanylmethyl) ether, tricyclodecanediyldimethylene (3-ethyl-3-oxetanylmethyl) ether, trimethylolpropane tris (3-ethyl-3-oxetanylmethyl) ether, 1,4-bis (3-ethyl-3-) Oxetanylmethoxy) butane, 1,6-bis (3-ethyl-3-oxetanylmethoxy) hexane, pentaerythritol tris (3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tetrakis (3-ethyl-3-oxetanylmethyl) Ether, polyethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol hexakis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol pentakis (3-ethyl-3-oxy) Tanylmethyl) ether, dipentaerythritol tetrakis (3-ethyl-3-oxetanylmethyl) ether, caprolactone-modified dipentaerythritol hexakis (3-ethyl-3-oxetanylmethyl) ether, caprolactone-modified dipentaerythritol pentakis (3-ethyl) -3-oxetanylmethyl) ether, ditrimethylolpropane tetrakis (3-ethyl-3-oxetanylmethyl) ether, EO-modified bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, PO-modified bisphenol A bis (3-ethyl) -3-Oxetanylmethyl) ether, EO-modified hydrogenated bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, PO-modified hydrogenated bisphenol A bis (3-ethyl-3- Kisetanirumechiru) ether, EO-modified bisphenol F (3- ethyl-3-oxetanylmethyl) include polyfunctional oxetanes such as ether.

The compound having such an oxetane ring is described in detail in paragraphs [0021] to [0084] of JP-A No. 2003-341217, and the compounds described therein can be preferably used.
Among the oxetane compounds, it is preferable to use a compound having 1 to 2 oxetane rings from the viewpoint of viscosity and adhesiveness of the ink composition.

  The cationic polymerizable monomer may be used alone or in combination of two or more. From the viewpoint of effectively suppressing shrinkage during curing, at least one oxetane compound, an epoxy compound, and a vinyl ether compound. It is preferable to use in combination with at least one compound selected from the group consisting of:

The polymerizable or crosslinkable material may be used alone or in combination of two or more.
The content of the polymerizable or crosslinkable material in the first liquid A and / or the second liquid B is 50 to 99.6% by mass with respect to the total solid content (mass) of each droplet. The range is preferable, the range of 70 to 99.0% by mass is more preferable, and the range of 80 to 99.0% by mass is more preferable.
Moreover, as content in a droplet, the range of 20-98 mass% is preferable with respect to the total mass of each droplet, The range of 40-95 mass% is more preferable, The range of 50-90 mass% is preferable. Particularly preferred.

-Polymerization initiator-
The first liquid A and the second liquid B can be suitably configured using at least one kind of polymerization initiator, and are preferably configured using at least the second liquid B. This polymerization initiator generates radicals and other starting species by applying actinic light, heat, or both, and initiates, accelerates and cures the polymerization or crosslinking reaction of the polymerizable or crosslinkable material described above. A compound.

  This polymerization initiator is preferably contained separately from the polymerizable material from the viewpoint of ensuring the storage stability of the first liquid A and the second liquid B. In the present invention, the first liquid A contains A mode in which the polymerizable or crosslinkable material is contained and the second liquid B or other liquid contains a polymerization initiator is preferable.

In the polymerizable embodiment, it preferably contains a polymerization initiator that causes radical polymerization or cationic polymerization, and particularly preferably contains a photopolymerization initiator.
A polymerization initiator is a compound that undergoes a chemical change through the action of light or interaction with the electronically excited state of a sensitizing dye to produce at least one of a radical, an acid, and a base. From the viewpoint that polymerization can be initiated by a simple means of exposure, the photo radical generator or the photo acid generator is preferred.

  The photopolymerization initiator is an actinic ray to be irradiated, for example, 400 to 200 nm ultraviolet ray, far ultraviolet ray, g ray, h ray, i ray, KrF excimer laser beam, ArF excimer laser beam, electron beam, X ray, molecular beam. Or what has a sensitivity to an ion beam etc. can be selected suitably, and can be used.

  Specific photopolymerization initiators known to those skilled in the art can be used without limitation, and specifically, for example, Bruce M. et al. Monroe et al., Chemical Review, 93, 435 (1993). R. S. By Davidson, Journal of Photochemistry and biologic A: Chemistry, 73.81 (1993). J. P. Faussier “Photoinitiated Polymerization—Theory and Applications”: Rapra Review vol. 9, Report, Rapra Technology (1998). M. Tsunooka et al. , Prog. Polym. Sci. , 21, 1 (1996). Many are described. There are many chemical amplification type photoresists and compounds used for photocationic polymerization described in (Organic Electronics Materials Research Group, “Organic Materials for Imaging”, Bunshin Publishing (1993), pages 187-192). Has been. Further, F.I. D. Saeva, Topics in Current Chemistry, 156, 59 (1990). G. G. Maslak, Topics in Current Chemistry, 168, 1 (1993). H., et al. B. Shuster et al, JACS, 112, 6329 (1990). I. D. F. Eaton et al, JACS, 102, 3298 (1980). A group of compounds that undergo bond oxidative or reductive cleavage through interaction with the electronically excited state of the sensitizing dye described in the above.

  Preferred photopolymerization initiators include (a) aromatic ketones, (b) aromatic onium salt compounds, (c) organic peroxides, (d) hexaarylbiimidazole compounds, (e) ketoxime ester compounds, f) borate compounds, (g) azinium compounds, (h) metallocene compounds, (i) active ester compounds, (j) compounds having a carbon halogen bond, and the like.

  Preferable examples of the (a) aromatic ketones include “RADIATION CURING IN POLYMER SCIENCE AND TECHNOLOGY” P. FOUASSIER J.M. F. Examples include compounds having a benzophenone skeleton or a thioxanthone skeleton described in RABEK (1993), p77-117. More preferable examples of (a) aromatic ketones include α-thiobenzophenone compounds described in JP-B-47-6416, benzoin ether compounds described in JP-B-47-3981, and JP-B-47-22326. Α-substituted benzoin compounds, benzoin derivatives described in JP-B-47-23664, aroylphosphonic acid esters described in JP-A-57-30704, dialkoxybenzophenones described in JP-B-60-26483, Benzoin ethers described in JP-A-60-26403, JP-A-62-81345, JP-B-1-34242, US Pat. No. 4,318,791, and α-aminobenzophenones described in European Patent 0284561A1, P-di (dimethyla) described in JP-A-2-211452 Nobenzoyl) benzene, thio-substituted aromatic ketone described in JP-A-61-194062, acylphosphine sulfide described in JP-B-2-9597, acylphosphine described in JP-B-2-9596, JP-B-63- Examples thereof include thioxanthones described in Japanese Patent No. 61950, and coumarins described in Japanese Patent Publication No. 59-42864.

  As the (b) aromatic onium salt compound, elements of Group V, VI and VII of the periodic table, specifically N, P, As, Sb, Bi, O, S, Se, Te, or I Of the aromatic onium salt. For example, iodonium salts described in European Patent No. 104143, US Pat. No. 4,837,124, Japanese Patent Laid-Open No. 2-150848, Japanese Patent Laid-Open No. 2-96514, European Patent Nos. 370693, 233567, and 297443 are disclosed. , 294442, 279210, and 422570, U.S. Pat. Nos. 3,902,144, 4,933,377, 4,760013, 4,734,444, and 2,833,827, sulfonium salts and diazonium salts (Such as benzenediazonium which may have a substituent), diazonium salt resins (formaldehyde resin of diazodiphenylamine, etc.), N-alkoxypyridinium salts, etc. (for example, US Pat. No. 4,743,528, JP 63-1383 No. 5, JP-A-63-142345, JP-A-63-142346, and JP-B-46-42363, specifically 1-methoxy-4-phenylpyridinium tetrafluoro And the compounds described in JP-B Nos. 52-147277, 52-14278, and 52-14279 are preferably used. Generates radicals and acids as active species.

  The (c) “organic peroxide” includes almost all organic compounds having one or more oxygen-oxygen bonds in the molecule. Examples thereof include 3,3 ′, 4,4′- Tetra- (t-butylperoxycarbonyl) benzophenone, 3,3'4,4'-tetra- (t-amylperoxycarbonyl) benzophenone, 3,3'4,4'-tetra- (t-hexylperoxy) Carbonyl) benzophenone, 3,3′4,4′-tetra- (t-octylperoxycarbonyl) benzophenone, 3,3′4,4′-tetra- (cumylperoxycarbonyl) benzophenone, 3,3′4 Peroxide esters such as 4'-tetra- (p-isopropylcumylperoxycarbonyl) benzophenone and di-t-butyldiperoxyisophthalate are preferred.

  Examples of the (d) hexaarylbiimidazole compound include lophine dimers described in JP-B Nos. 45-37377 and 44-86516, such as 2,2′-bis (o-chlorophenyl) -4,4 ′. , 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-bromophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o, p- Dichlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-chlorophenyl) -4,4 ′, 5,5′-tetra (m-methoxyphenyl) biimidazole, 2,2′-bis (o, o′-dichlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-nitrophenyl) -4,4 ′, 5 5'-tetraphenylbiimi Dazole, 2,2′-bis (o-methylphenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-trifluorophenyl) -4,4 ′, 5 , 5′-tetraphenylbiimidazole and the like.

  Examples of the (e) ketoxime ester compound include 3-benzoyloxyiminobutan-2-one, 3-acetoxyiminobutan-2-one, 3-propionyloxyiminobutan-2-one, and 2-acetoxyimino. Pentan-3-one, 2-acetoxyimino-1-phenylpropan-1-one, 2-benzoyloxyimino-1-phenylpropan-1-one, 3-p-toluenesulfonyloxyiminobutan-2-one, And 2-ethoxycarbonyloxyimino-1-phenylpropan-1-one.

Examples of the (f) borate compound include compounds described in US Pat. Nos. 3,567,453 and 4,343,891, European Patents 109,772 and 109,773.
Examples of the (g) azinium salt compound include JP-A-63-138345, JP-A-63-142345, JP-A-63-142346, JP-A-63-143537, and JP-B-46-42363. The compound group which has NO bond as described in each gazette of No. can be mentioned.

  Examples of the (h) metallocene compound include JP-A-59-152396, JP-A-61-151197, JP-A-63-41484, JP-A-2-249, and JP-A-2-4705. And the iron-arene complexes described in JP-A-1-304453 and JP-A-1-152109.

  Specific examples of the titanocene compound include di-cyclopentadienyl-Ti-di-chloride, di-cyclopentadienyl-Ti-bis-phenyl, and di-cyclopentadienyl-Ti-bis-2,3. 4,5,6-pentafluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-cyclopentadienyl-Ti- Bis-2,4,6-trifluorophen-1-yl, di-cyclopentadienyl-Ti-2,6-difluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,4 -Difluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluorophen-1-yl, di-methylcyclopentadienyl-Ti- -2,3,5,6-tetrafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,4-difluorophen-1-yl, bis (cyclopentadienyl) -bis (2,6-difluoro-3- (pyridin-1-yl) phenyl) titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (methylsulfonamido) phenyl] titanium, bis (cyclopenta And dienyl) bis [2,6-difluoro-3- (N-butylbialoyl-amino) phenyl] titanium.

  Examples of the (i) active ester compound include European Patent Nos. 0290750, 046083, 156153, 271851, and 0388343, U.S. Pat. Nos. 3,901,710, and 4,181,531, Nitrobenzol ester compounds described in JP-A-60-198538 and JP-A-53-133022, European Patents 0199672, 84515, 199672, 0441115, and 0101122 , U.S. Pat. Nos. 4,618,564, 4,371,605 and 4,431,774, JP-A 64-18143, JP-A-2-245756, and JP-A-4-365048, respectively. Kosho 62-6223, Tokusho Sho No. 3-14340, and include compounds described in JP-59-174831 each publication.

  Preferred examples of the compound (j) having a carbon halogen bond include those described in Wakabayashi et al., Bull. Chem. Soc. Examples include compounds described in Japan, 42, 2924 (1969), compounds described in British Patent 1388492, compounds described in JP-A-53-133428, compounds described in German Patent 3333724, and the like. .

  F.F. C. J. Schaefer et al. Org. Chem. 29, 1527 (1964), compounds described in JP-A-62-258241, compounds described in JP-A-5-281728, and the like. A compound as described in German Patent No. 2641100, a compound described in German Patent No. 3333450, a compound group described in German Patent No. 3021590, or a compound group described in German Patent No. 3021599, etc. Can be mentioned.

  Preferable specific examples of the compounds represented by the above (a) to (j) include those shown below.

  The polymerization initiator preferably has excellent sensitivity. For example, it is not preferable to use one that causes thermal decomposition at a temperature of 80 ° C. or lower from the viewpoint of storage stability, and thermal decomposition occurs at a temperature up to 80 ° C. It is preferred to select a polymerization initiator that is not present.

  A polymerization initiator can be used 1 type or in combination of 2 or more types. Moreover, a well-known sensitizer can also be used together for the purpose of a sensitivity improvement in the range which does not impair the effect of this invention.

  The content of the polymerization initiator in the second liquid B is the maximum amount required for image formation of the first liquid A and the second liquid B from the viewpoint of stability over time, curability, and curing speed. When droplets are ejected onto the medium, the content is preferably 0.5 to 20% by mass, more preferably 1 to 15% by mass, and particularly preferably 3 to 10% by mass with respect to the polymerizable material applied per unit area. . When the content is too large, precipitation or separation with time may occur, or performance such as strength and rubbing resistance of the ink after curing may be deteriorated.

The polymerization initiator may be contained in the second liquid B and may be contained in the first liquid A. In this case, the storage stability of the first liquid A can be maintained within a desired range. It can be appropriately selected and contained.
Further, the polymerization initiator may be contained in the first liquid A described above without being contained in the second liquid B. In this case, the content in the first droplet is preferably 0.5 to 20% by mass and more preferably 1 to 15% by mass with respect to the polymerizable or crosslinkable compound in the first liquid A. .

-Sensitizing dye-
In the present invention, a sensitizing dye may be added for the purpose of improving the sensitivity of the photopolymerization initiator. Examples of preferred sensitizing dyes include those belonging to the following compounds and having an absorption wavelength in the 350 nm to 450 nm region.

  Polynuclear aromatics (eg, pyrene, perylene, triphenylene), xanthenes (eg, fluorescein, eosin, erythrosine, rhodamine B, rose bengal), cyanines (eg, thiacarbocyanine, oxacarbocyanine), merocyanines ( For example, merocyanine, carbomerocyanine), thiazines (for example, thionine, methylene blue, toluidine blue), acridines (for example, acridine orange, chloroflavin, acriflavine), anthraquinones (for example, anthraquinone), squalium (for example, squalium) ), Coumarins (eg 7-diethylamino-4-methylcoumarin).

  More preferable examples of the sensitizing dye include compounds represented by the following general formulas (IX) to (XIII).

In the formula (IX), A ¹ represents a sulfur atom or NR ⁵⁰ , R ⁵⁰ represents an alkyl group or an aryl group, and L ² forms a basic nucleus of the dye together with the adjacent A ¹ and the adjacent carbon atom. R ⁵¹ and R ⁵² each independently represent a hydrogen atom or a monovalent nonmetallic atomic group, and R ⁵¹ and R ⁵² may be bonded to each other to form an acidic nucleus of the dye. Good. W represents an oxygen atom or a sulfur atom.
In formula (X), Ar ¹ and Ar ² each independently represent an aryl group and are linked via a bond with —L ³ —. Here, L ³ represents —O— or —S—. W is synonymous with that shown in the general formula (IX).
In the formula (XI), A ² represents a sulfur atom or NR ⁵⁹ , L ⁴ represents a nonmetallic atomic group that forms a basic nucleus of the dye together with adjacent A ² and a carbon atom, R ⁵³ , R ⁵⁴ , R ⁵⁵ , R ⁵⁶ , R ⁵⁷ and R ⁵⁸ each independently represents a monovalent nonmetallic atomic group, and R ⁵⁹ represents an alkyl group or an aryl group.

In formula (XII), A ³ and A ⁴ each independently represent —S— or —NR ⁶² — or —NR ⁶³ —, wherein R ⁶² and R ⁶³ each independently represent a substituted or unsubstituted alkyl group, substituted or represents an unsubstituted aryl group, L to ^5, L ⁶ are each independently, together with the adjacent a ^3, a ⁴ and adjacent carbon atoms represents a nonmetallic atom group necessary for forming a basic nucleus of a dye, R ⁶⁰ , R ⁶¹ each independently represents a hydrogen atom or a monovalent non-metallic atomic group, or may be bonded to each other to form an aliphatic or aromatic ring.
In the formula (XIII), R ⁶⁶ represents an aromatic ring or a hetero ring which may have a substituent, and A ⁵ represents an oxygen atom, a sulfur atom or —NR ⁶⁷ —. R ⁶⁴ , R ⁶⁵ and R ⁶⁷ each independently represent a hydrogen atom or a monovalent nonmetallic atomic group, and R ⁶⁷ and R ⁶⁴ , and R ⁶⁵ and R ⁶⁷ each represent an aliphatic or aromatic ring. Can be combined to form.

  Preferable specific examples of the compounds represented by the general formulas (IX) to (XIII) include the exemplified compounds (A-1) to (A-20) shown below.

--Co-sensitizer--
Furthermore, a known compound having a function of further improving sensitivity or suppressing polymerization inhibition by oxygen may be added as a co-sensitizer.
Examples of co-sensitizers include amines such as M.I. R. Sander et al., “Journal of Polymer Society”, Vol. 10, 3173 (1972), Japanese Patent Publication No. 44-20189, Japanese Patent Publication No. 51-82102, Japanese Patent Publication No. 52-134692, Japanese Patent Publication No. 59-138205. No. 60-84305, JP-A 62-18537, JP-A 64-33104, Research Disclosure 33825, and the like. Specific examples include triethanolamine. P-dimethylaminobenzoic acid ethyl ester, p-formyldimethylaniline, p-methylthiodimethylaniline and the like.

Other examples include thiols and sulfides, for example, thiol compounds described in JP-A-53-702, JP-B-55-500806, JP-A-5-142772, and JP-A-56-75643. Specific examples include 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, 2-mercaptobenzimidazole, 2-mercapto-4 (3H) -quinazoline, β-mercaptonaphthalene, and the like. .
Other examples include amino acid compounds (eg, N-phenylglycine), organometallic compounds described in Japanese Patent Publication No. 48-42965 (eg, tributyltin acetate), and hydrogen described in Japanese Patent Publication No. 55-34414. Donors, sulfur compounds described in JP-A-6-308727 (eg, trithiane), phosphorus compounds described in JP-A-6-250387 (diethylphosphite, etc.), Si-- described in JP-A-8-65779 H, Ge-H compound, etc. are mentioned.

  In the second liquid B, the organic material particles according to the present invention described above can be suitably used with or without being contained in the first liquid A. Preferably, the sp value is Is adjusted to be 35 or less. The second liquid B is preferably water-insoluble and adjusted to the properties of the oil-soluble organic solvent system.

  When the sp value of the second liquid B is 35 or less, for example, between the first liquid A (droplet a1, droplet a2,...) Containing a polymerizable or crosslinkable material as described above. The affinity between the liquid droplets and the first liquid droplet a1 and the liquid droplet a2 can be prevented from being coalesced when the droplets a2 and a2 are applied with overlapping portions, and blurring of the image and lines such as fine lines in the image can be prevented. Generation of width variation can be effectively prevented.

  The droplets a1, droplets a2,... Of the first liquid A can be suitably prepared in an organic solvent system containing a polymerizable or crosslinkable material, and the second liquid when prepared in an organic solvent system. It is easy to mix with B, and it is possible to effectively avoid coalescence between droplets such as between the first droplet a1 and the droplet a2 that are ejected so as to contact each other and have an overlapping portion. Thereby, as described above, it is possible to effectively prevent the occurrence of blurring of the image and line width variations such as fine lines in the image.

The sp value of the second liquid B can be suitably adjusted using an oleophilic solvent (high boiling point organic solvent, polymerizable compound) or the like. As one of the preferable adjustment modes, the lipophilic solvent may be contained in the range of 50% by mass or more and 100% by mass or less of the total mass of the second liquid B. When the content of the lipophilic solvent is within the above range, the sp value can be reduced and adjusted to a range of 35 or less.
A more preferable range of the sp value of the second liquid is 30 or less, and particularly preferably 25 or less.

The sp value is defined for various solvents and solutes, and is a value indicating the ease of dissolution between solvent / solvent and between solvent / solute. This value is calculated from the change in energy when the solvent and the solvent are mixed, and when the solute dissolves in the solvent, the sp value used in the present invention is specifically the sp value by Tohoku University RLsmith. It is obtained by calculation with a value calculation program. In the calculation, with reference to 25 ° C., except for compounds not containing carbon atoms, the structural units such as polymers and polyethylene chains are saturated repeating units having bonds (for example, —CH ₂ —CH (C in the case of styrene). ₆ H ₅ )-) and water (H ₂ O) is calculated as 47.8.

-Lipophilic solvent-
The oleophilic solvent is effective in preventing the occurrence of blurring of the image and line width variations such as fine lines in the image, and can adjust the sp value of the second liquid to the above-described range.
“Lipophilic” refers to a compound having a solubility of 1 g or less with respect to 100 cc of water.

  The lipophilic solvent can be contained in the first liquid A described above with or without being contained in the second liquid B. Further, it may be contained in a liquid other than the second liquid B and the first liquid A.

Examples of the oleophilic solvent include high-boiling organic solvents and the above-described polymerizable compounds. High-boiling organic solvents are preferable for avoiding nozzle solidification and the like, and polymerization is performed to increase the film strength of the film formed with ink. It is preferable to use a functional compound.
Hereinafter, the high boiling point organic solvent suitable in the present invention will be described.

  As the high-boiling organic solvent, (1) a viscosity at 25 ° C. of 100 mPa · s or less or a viscosity at 60 ° C. of 30 mPa · s or less and (2) a boiling point higher than 100 ° C. is preferable.

  A high boiling point organic solvent that does not satisfy any of the above viscosity conditions (1) may increase the viscosity and hinder application on a recording medium, and satisfy the boiling point condition (2). If the organic solvent has a high boiling point, the boiling point becomes too low and the solvent evaporates during image recording, which may reduce the effect of the present invention.

  Among the conditions (1), the viscosity at 25 ° C. is preferably in the range of 70 mPa · s or less, more preferably in the range of 40 mPa · s or less, and particularly preferably in the range of 20 mPa · s or less. The viscosity at 60 ° C. is more preferably in the range of 20 mPa · s or less, and particularly preferably in the range of 10 mPa · s or less. Regarding the condition (2), the boiling point is more preferably in the range of 150 ° C. or more, and particularly preferably in the range of 170 ° C. or more. Moreover, as a lower limit of melting | fusing point, the range of 80 degrees C or less is preferable. Furthermore, the solubility (25 ° C.) of water is preferably 4 g or less, more preferably 3 g or less, further preferably 2 g or less, and particularly preferably 1 g or less.

  The “viscosity” here is a viscosity determined using a RE80 viscometer manufactured by Toki Sangyo Co., Ltd. The RE80 type viscometer is a conical rotor / flat plate type viscometer corresponding to the E type, and the rotor code No. 1 rotor was used and the measurement was performed at a rotation speed of 10 rpm. However, for those having a viscosity higher than 60 mPa · s, the rotational speed is 5 r.p.m., 2.5 r.p.m., 1 r.p.m., 0.5 r.p.m. The measurement was performed by changing to.

  The “water solubility” is the saturation concentration of water in a high boiling point organic solvent at 25 ° C., and means the mass (g) of water that can be dissolved in 100 g of the high boiling point organic solvent at 25 ° C.

  As the high boiling organic solvent, compounds represented by the following formulas [S-1] to [S-9] are preferable.

In the formula [S-1], R ₁ , R ₂ and R ₃ each independently represents an aliphatic group or an aryl group. A, b and c each independently represent 0 or 1;

In the formula [S-2], R ₄ and R ₅ each independently represents an aliphatic group or an aryl group, and R ₆ represents a halogen atom (F, Cl, Br, I and so on), an alkyl group, an alkoxy group, Represents an aryloxy group, an alkoxycarbonyl group or an aryloxycarbonyl group, and d represents an integer of 0 to 3. When d is plural, plural R ₆ may be the same or different.

In the formula [S-3], Ar represents an aryl group, e represents an integer of 1 to 6, and R ₇ represents an e-valent hydrocarbon group or a hydrocarbon group bonded to each other through an ether bond.

In the formula [S-4], R ₈ represents an aliphatic group, f represents an integer of 1 to 6, and R ₉ represents an f-valent hydrocarbon group or a hydrocarbon group bonded to each other through an ether bond.

In the formula [S-5], g represents an integer of 2 to 6, R ₁₀ represents a g-valent hydrocarbon group (excluding an aryl group), and R ₁₁ represents an aliphatic group or an aryl group.

In the formula [S-6], R ₁₂ , R ₁₃ and R ₁₄ each independently represents a hydrogen atom, an aliphatic group or an aryl group. X represents —CO— or —SO ₂ —. R ₁₂ and R ₁₃ or R ₁₃ and R ₁₄ may be bonded to each other to form a ring.

In the formula [S-7], R ₁₅ represents an aliphatic group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, an aryl group or a cyano group, and R ₁₆ represents a halogen atom, an aliphatic group or an aryl group. Represents a group, an alkoxy group or an aryloxy group, and h represents an integer of 0 to 3. When h is plural, plural R ₁₆ may be the same or different.

In the formula [S-8], R ₁₇ and R ₁₈ each independently represents an aliphatic group or an aryl group, R ₁₉ represents a halogen atom, an aliphatic group, an aryl group, an alkoxy group or an aryloxy group, and i Represents an integer of 0 to 5. When i is plural, plural R ₁₉ may be the same or different.

In the formula [S-9], R ₂₀ and R ₂₁ each independently represents an aliphatic group or an aryl group. j represents 1 or 2; R ₂₀ and R ₂₁ may be bonded to each other to form a ring.

In the formulas [S-1] to [S-9], when R _{1 to} R ₆ , R ₈ and R _{11 to} R ₂₁ are an aliphatic group or a group containing an aliphatic group, the aliphatic group is a straight chain, It may be branched or cyclic, and may contain an unsaturated bond or may have a substituent. Examples of the substituent include a halogen atom, an aryl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, a hydroxyl group, an acyloxy group, and an epoxy group.

In the formulas [S-1] to [S-9], R _{1 to} R ₆ , R ₈ and R _{11 to} R ₂₁ are cyclic aliphatic groups, that is, cycloalkyl groups, or groups containing cycloalkyl groups. Sometimes, the cycloalkyl group may contain an unsaturated bond in the 3- to 8-membered ring, and may have a substituent or a bridging group. Examples of the substituent include a halogen atom, an aliphatic group, a hydroxyl group, an acyl group, an aryl group, an alkoxy group, and an epoxy group, and examples of the crosslinking group include methylene, ethylene, isopropylidene, and the like.

In the formulas [S-1] to [S-9], when R _{1 to} R ₆ , R ₈ , R _{11 to} R ₂₁ , Ar is an aryl group or a group containing an aryl group, the aryl group is a halogen atom, aliphatic It may be substituted with a substituent such as a group, an aryl group, an alkoxy group, an aryloxy group, or an alkoxycarbonyl group.

In the formulas [S-3], [S-4], and [S-5], when R ₇ , R _9, or R ₁₀ is a hydrocarbon group, the hydrocarbon group is a cyclic structure (for example, a benzene ring, a cyclopentane ring, A cyclohexane ring) or an unsaturated bond, and may have a substituent. Examples of the substituent include a halogen atom, a hydroxyl group, an acyloxy group, an aryl group, an alkoxy group, an aryloxy group, and an epoxy group.

Hereinafter, among the high boiling point organic solvents represented by the formulas [S-1] to [S-9], particularly preferred high boiling point organic solvents will be described.
In the formula [S-1], R ₁ , R ₂ and R ₃ are each independently an aliphatic group having 1 to 24 (preferably 4 to 18) carbon atoms (for example, n-butyl, n-hexyl, n -Octyl, EH-octyl, 2-ethylhexyl, 3,3,5-trimethylhexyl, 3,5,5-trimethylhexyl, n-dodecyl, n-octadecyl, benzyl, oleyl, 2-chloroethyl, 2,3-dichloro Propyl, 2-butoxyethyl, 2-phenoxyethyl, cyclopentyl, cyclohexyl, 4-t-butylcyclohexyl, 4-methylcyclohexyl) or an aryl group having 6 to 24 (preferably 6 to 18) carbon atoms (for example, phenyl, Cresyl, p-nonylphenyl, xylyl, cumenyl, p-methoxyphenyl, p-methoxycarbonylphenyl) are preferred Yes. Among these, R ₁ , R ₂ and R ₃ are particularly n-hexyl, n-octyl, EH-octyl, 2-ethylhexyl, 3,5,5-trimethylhexyl, n-dodecyl, 2-chloroethyl, 2- Butoxyethyl, cyclohexyl, phenyl, cresyl, p-nonylphenyl and cumenyl are preferred.
a, b and c are each independently 0 or 1, and more preferably a, b and c are all 1.

In the formula [S-2], R ₄ and R ₅ are each independently an aliphatic group having 1 to 24 (preferably 4 to 18) carbon atoms (for example, the same group as the aliphatic group mentioned for R ₁ above). , Heptyl, ethoxycarbonylmethyl, 1,1-diethylpropyl, 2-ethyl-1-methylhexyl, cyclohexylmethyl, 1-ethyl-1,5-dimethylhexyl, 3,5,5-trimethylcyclohexyl, menthyl, bornyl, 1-methylcyclohexyl) or an aryl group having 6 to 24 (preferably 6 to 18) carbon atoms (for example, the aryl group mentioned for R ₁ , 4-t-butylphenyl, 4-t-octylphenyl, 1, 3,5-trimethylphenyl, 2,4, -di-t-butylphenyl, 2,4, -di-t-pentylphenyl) are preferred. Among these, R ₄ and R ₅ are more preferably aliphatic groups, and particularly preferably n-butyl, heptyl, 2-ethylhexyl, n-dodecyl, 2-butoxyethyl, and ethoxycarbonylmethyl.
R ₆ is a halogen atom (preferably a chlorine atom), an alkyl group having 1 to 18 carbon atoms (eg, methyl, isopropyl, t-butyl, n-dodecyl), an alkoxy group having 1 to 18 carbon atoms (eg, methoxy, n -Butoxy, n-octyloxy, methoxyethoxy, benzyloxy), an aryloxy group having 6 to 18 carbon atoms (for example, phenoxy, p-tolyloxy, 4-methoxyphenoxy, 4-t-butylphenoxy) or 2 carbon atoms A C-19 alkoxycarbonyl group (for example, methoxycarbonyl, n-butoxycarbonyl, 2-ethylhexyloxycarbonyl) or an aryloxycarbonyl group having 6 to 25 carbon atoms is preferred. Among these, R ₆ is further preferably an alkoxycarbonyl group, and particularly preferably n-butoxycarbonyl.
d is 0 or 1.

In the formula [S-3], Ar is an aryl group having 6 to 24 (preferably 6 to 18) carbon atoms (for example, phenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 4-methoxyphenyl, 1-naphthyl, 4- n-butoxyphenyl, 1,3,5-trimethylphenyl, 2- (2-n-butoxycarbonylphenyl) phenyl) are preferable, and among these, Ar is phenyl, 2,4-dichlorophenyl, 2- (2 -N-Butoxycarbonylphenyl) phenyl is preferred.
e is an integer of 1 to 4 (preferably 1 to 3).
R ₇ is an e-valent hydrocarbon group having 2 to 24 (preferably 2 to 18) carbon atoms [for example, the aliphatic group mentioned above for R ₄ , n-octyl, the aryl group mentioned for R ₄ ,-( CH _{2) 2} -,

] Or an e-valent hydrocarbon group having 4 to 24 (preferably 4 to 18) carbon atoms and bonded to each other by an ether bond [for example, —CH ₂ CH ₂ OCH ₂ CH ₂ —, —CH ₂ CH ₂ (OCH _{2 CH 2) 3 -, - CH} 2 CH 2 CH 2 OCH 2 CH 2 CH 2 -,

] Is preferable. Among these, R ₇ is more preferably an alkyl group, and particularly preferably n-butyl, n-octyl and 2-ethylhexyl.

In the formula [S-4], R ₈ is an aliphatic group having 1 to 24 (preferably 1 to 17) carbon atoms (for example, methyl, n-propyl, 1-hydroxyethyl, 1-ethylpentyl, n-heptyl, n - undecyl, n- tridecyl, pentadecyl, 8,9-epoxy heptadecyl, cyclopropyl, cyclohexyl, 4-methylcyclohexyl). among them, R ₈ in particular, n- heptyl, n- tridecyl, 1-hydroxy Ethyl, 1-ethylpentyl, and 8,9-epoxyheptadecyl are preferred.
f is an integer of 1 to 4 (preferably 1 to 3).
R ₉ is a hydrocarbon group having 2 to 24 (preferably 2 to 18) f-valent carbon atoms or a hydrocarbon group linked to each other by an ether bond having 4 to 24 (preferably 4 to 18) f-valent carbon atoms. (For example, the groups mentioned for R ₇ , 1-methyl-2-methoxyethyl, 2-hexyldecyl) are preferable, and among these, R ₉ is particularly 2-ethylhexyl, 2-hexyldecyl, 1-methyl-2 -Methoxyethyl,

Is preferred.

In the formula [S-5], g is 2 to 4 (preferably 2 or 3).
R ₁₀ represents a g-valent hydrocarbon group [for example, —CH ₂ —, — (CH ₂ ) ₂ —, — (CH ₂ ) ₄ —, — (CH ₂ ) ₇ —, — (CH ₂ ) ₈ —,

Among these, R ₁₀ is particularly — (CH ₂ ) ₄ —, — (CH ₂ ) ₈ —,

Is preferred.
R ₁₁ is an aliphatic group having 1 to 24 (preferably 4 to 18) carbon atoms, or an aryl group having 6 to 24 (preferably 6 to 18) carbon atoms (for example, the aliphatic groups mentioned for R ₄ above, Aryl group). Among these, R ₁₁ is more preferably an alkyl group, and n-butyl, n-octyl, and 2-ethylhexyl are particularly preferable.

In the formula [S-6], R ₁₂ is a hydrogen atom, an aliphatic group having 1 to 24 carbon atoms (preferably 3 to 20) [for example, n-propyl, 1-ethylpentyl, n-undecyl, n-pentadecyl, 2,4-di-t-pentylphenoxymethyl, 4-t-octylphenoxymethyl, 3- (2,4-di-t-butylphenoxy) propyl, 1- (2,4-di-t-butylphenoxy) propyl Cyclohexyl, 4-methylcyclohexyl, 8-N, N-diethylcarbamoyloctyl], or an aryl group having 6 to 24 (preferably 6 to 18) carbon atoms (for example, the aryl group mentioned for Ar, 3-methylphenyl) , 2-(N, N-di -n- octylcarbamoyl) phenyl). among them, R ₁₂ is especially, n- undecyl, 8-N, N-di Ji carbamoyl octyl, 3-methylphenyl, 2-(N, N-di -n- octylcarbamoyl) phenyl are preferred.
R ₁₃ and R ₁₄ are each a hydrogen atom or an aliphatic group having 1 to 24 (preferably 1 to 18) carbon atoms (eg, methyl, ethyl, isopropyl, n-butyl, n-hexyl, n-octyl, 2-ethylhexyl). , N-dodecyl, n-tetradecyl, cyclopentyl, cyclopropyl) or an aryl group having 6 to 18 carbon atoms (preferably 6 to 15) (for example, phenyl, 1-naphthyl, p-tolyl), among these, R ₁₃ and R ₁₄ are particularly preferably methyl, ethyl, n-butyl, n-octyl, n-tetradecyl and phenyl.
R ₁₃ and R ₁₄ may be bonded to each other to form a pyrrolidine ring, piperidine ring or morpholine ring together with N, and R ₁₂ and R ₁₃ may be bonded to each other to form a pyrrolidone ring or piperidine ring together with N. Also good.
X is —CO— or —SO ₂ —, and preferably X is —CO—.

In the formula [S-7], R ₁₅ is an aliphatic group having 1 to 24 (preferably 3 to 18) carbon atoms (for example, methyl, isopropyl, t-butyl, t-pentyl, t-hexyl, t-octyl, 2 -Butyl, 2-hexyl, 2-octyl, 2-dodecyl, 2-hexadecyl, t-pentadecyl, cyclopentyl, cyclohexyl), an alkoxycarbonyl group having 2 to 24 (preferably 5 to 17) carbon atoms (for example, n-butoxy) Carbonyl, 2-ethylhexyloxycarbonyl, n-dodecyloxycarbonyl), aryloxycarbonyl group having 7 to 24 carbon atoms (preferably 7 to 18) (for example, phenoxycarbonyl group, naphthoxycarbonyl group, cresyloxycarbonyl group) An alkylsulfonyl group having 1 to 24 (preferably 1 to 18) carbon atoms ( For example, methylsulfonyl, n-butylsulfonyl, n-dodecylsulfonyl), arylsulfonyl groups having 6 to 30 carbon atoms (preferably 6 to 24) (for example, p-tolylsulfonyl, p-dodecylphenylsulfonyl, p-hexadecyloxy) Phenylsulfonyl), an aryl group having 6 to 32 carbon atoms (preferably 6 to 24 carbon atoms) (for example, phenyl, p-tolyl), or a cyano group is preferable, and among these, R ₁₅ is further having 1 to 24 carbon atoms. An aliphatic group and an alkoxycarbonyl group having 2 to 24 carbon atoms are more preferable, and an aliphatic group having 1 to 24 carbon atoms is particularly preferable.
R ₁₆ is a halogen atom (preferably Cl), an aliphatic group having 1 to 24 carbon atoms (preferably 1 to 18 carbon atoms) {more preferably an alkyl group (for example, the alkyl groups mentioned for R ₁₅ above), carbon atoms 3-18 (more preferably 5-17) cycloalkyl group (for example, cyclopentyl, cyclohexyl)}, aryl group having 6-32 (preferably 6-24) carbon atoms (for example, phenyl, p-tolyl), carbon atom An alkoxy group of 1 to 24 (preferably 1 to 18) (for example, methoxy, n-butoxy, 2-ethylhexyloxy, benzyloxy, n-dodecyloxy, n-hexadecyloxy) or 6 to 32 carbon atoms (preferably Is an aryloxy group (for example, phenoxy, pt-butylphenoxy, pt-octylphenoxy, m-pen) Decylphenoxy, a p- dodecyloxy-phenoxy) Of these, R ₁₆ is further more preferably an aliphatic group having 1 to 24 carbon atoms, particularly preferably an aliphatic group having 1 to 12 carbon atoms.
h is an integer of 1-2.

In the formula [S-8], preferred examples of R ₁₇ and R ₁₈ are the same as the examples other than the hydrogen atom in R ₁₃ and R ₁₄ , and among these, R ₁₇ and R ₁₈ further have an aliphatic group. More preferred are n-butyl, n-octyl and n-dodecyl. However, R ₁₇ and R ₁₈ are not bonded to each other to form a ring.
Preferred examples of R ₁₉ are the same as R ₁₆ described above, and among these, R ₁₉ is more preferably an alkyl group and an alkoxy group, and particularly preferably n-octyl, methoxy, n-butoxy and n-octyloxy. .
i is an integer of 1-5.

In the formula [S-9], preferred examples of R ₂₀ and R ₂₁ are the same as those of R ₁ , R ₂ and R ₃ when they are not bonded to form a ring. Among these, R ₂₀ and R ₂₁ Is particularly preferably a substituted or unsubstituted aliphatic group having 1 to 24 carbon atoms.
R ₂₀ and R ₂₁ may be bonded to each other to form a ring, and the formed ring is preferably a 3- to 10-membered ring, particularly preferably a 5- to 7-membered ring.
j represents 1 or 2, and preferably j is 1.

Hereinafter, specific examples of high-boiling organic solvents (Exemplary Compounds S-1 to S-53) and viscosities of the respective high-boiling organic solvents (values measured by the above means in an environment at 25 ° C. and 60 ° C .; mPa · s) And the boiling point (° C.).
Here, the boiling point of the high-boiling organic solvent is a value converted from the boiling point during vacuum distillation to normal pressure. In the following specific examples, those having no boiling point are confirmed not to boil at 170 ° C., and those having no viscosity at 25 ° C. are solid at 25 ° C.

  Even if one kind of high-boiling organic solvent is used alone, two or more kinds [for example, tricresyl phosphate and dibutyl phthalate, trioctyl phosphate and di (2-ethylhexyl) sebacate, dibutyl phthalate and poly (Nt- Butylacrylamide)]] may be used in combination.

  Examples of other high boiling point organic solvents and / or methods for synthesizing these high boiling point organic solvents include, for example, U.S. Pat. Nos. 2,322,027, 2,533,514, and 2, 772,163, 2,835,579, 3,594,171, 3,676,137, 3,689,271, 3,700,454, 3,748,141, 3,764,336, 3,765,897, 3,912,515, 3,936,303, 4,004 , 928, 4,080,209, 4,127,413, 4,193,802, 4,207,393, 4,220,711, No. 4,239,851, No. 4,278,757, No. 4,353,9 No. 9, No. 4,363,873, No. 4,430,421, No. 4,430,422, No. 4,464,464, No. 4,483,918, No. 4,540,657, 4,684,606, 4,728,599, 4,745,049, 4,935,321, 5,013,639 European Patent Nos. 276,319A, 286,253A, 289,820A, 309,158A, 309,159A, 309,160A, 509,311A No. 510,576A, East German Patent No. 147,009, No. 157,147, No. 159,573, No. 225,240A, British Patent No. 2,091,124A, etc. Description, JP-A-48-47335, 50 No. 26530, No. 51-25133, No. 51-26036, No. 51-27921, No. 51-27922, No. 51-149028, No. 52-46816, No. 53-1520, No. 53-1521 53-15127, 53-146622, 54-91325, 54-106228, 54-118246, 55-59464, 56-64333, 56-81836, 59-204041, 61-84641, 62-118345, 62-247364, 63-167357, 63-214744, 63-301941, 63-94552, 64-945 9454, 64-68745, JP-A-1-101543, 1-102454, 2-792, and 2 No. 4239, No. 2-43541, No. 4-29237, No. 4-30165, No. 4-232946, No. 4-346338, and the like.

  In the present invention, a high boiling organic solvent having a boiling point higher than 100 ° C. is preferable, and a high boiling organic solvent having a boiling point higher than 170 ° C. is more preferable.

  The polymerizable compound described above can be used as the polymerizable compound that can be used in the present invention.

  The addition amount of the lipophilic solvent in the second liquid is preferably in the range of 50% by mass to 100% by mass, more preferably in the range of 70% by mass to 100% by mass, with respect to the total mass of the liquid, 90 A mass% or more and 100 mass% or less is particularly preferable.

The first liquid A is prepared such that the difference in sp value from the second liquid B is 10 or less. The difference in sp value with the second liquid B applied in advance before the first droplet a1 is ejected is 10 or less and the affinity is high, and when the droplet is ejected in contact with the subsequent droplet a2. The coalescence of droplets can be effectively prevented. A preferable difference in sp value is 5 or less.
When the difference in sp value between the first liquid A and the second liquid B is within the above range, the liquids are easily dissolved, and the liquid droplet a1 is between the liquid droplet B rather than between the liquid droplet a2. Since the contact area is larger, the affinity with the second liquid B is better, and for example, the droplets a1, a2,... Applied with overlapping portions are colored. In the case of containing an agent, it is effective in causing color bleeding and color mixing between the droplets a1 and a2, and avoiding line width variation of a colored line image.

  The sp value can be suitably adjusted using a lipophilic solvent, a polymerizable material, etc., which will be described later. For example, the sp value can be further lowered by increasing the ratio of the lipophilic solvent in the droplets.

In the present invention, as a preferred form,
(1) The first liquid A contains a polymerizable or crosslinkable material and “organic material particles having an average particle size of 50 nm or less and a coefficient of variation of the particle size of 50%”, and the second liquid B is polymerized Form (2) containing an initiator, the first liquid A contains a polymerizable or crosslinkable material and “organic material particles having an average particle size of 50 nm or less and a coefficient of variation of the particle size of 50%”; The liquid B contains a polymerization initiator and a lipophilic solvent.
In the above, the polymerizable or crosslinkable material is contained in the first liquid A, and may be contained in the second liquid B within a range that does not impair the effects of the present invention. It may be contained in the 1st liquid A in the range which does not inhibit the effect of this invention while containing in the 2nd liquid B which concerns.

In the ink set for ink-jet recording of the present invention, “organic material particles having an average particle size of 50 nm or less and a particle size variation coefficient of 50%” are added to the first liquid A and / or the second liquid B. In addition to containing, the first liquid A contains a polymerizable or crosslinkable material for forming an image, the second liquid B has an sp value of 35 or less, and the first liquid A A configuration in which the difference in sp value is 10 or less is preferable.
In particular, when recording an image on a recording medium having a low liquid absorbency such as a non-penetrating or slow penetrating recording medium, adjacent droplets provided with overlapping portions to obtain a high image density. If the (first droplet a1 and droplet a2) stay on and contact the medium before drying, the image blurs and the line width of the thin line becomes non-uniform, resulting in sharp images. Although the formability is likely to be impaired, the droplet a1 and the droplet a2 have overlapping portions due to the configuration in which the sp value of the liquid B is specified in advance before the first droplet a1 and the droplet a2 are deposited. Even if applied, the unity between the droplets a1 and a2 is suppressed, and the occurrence of image bleeding and line width variations such as fine lines in the image is effectively prevented, so that the image resolution of high image density It is possible to form a sharp line with a uniform width while ensuring a high quality image.

<Other ingredients>
In addition to the components described above, known additives can be used in combination according to the purpose.
~ Storage stabilizer ~
A storage stabilizer can be added to the first liquid A and the second liquid B (preferably to the first liquid A) according to the present invention for the purpose of suppressing undesirable polymerization during storage. The storage stabilizer is preferably used in the presence of a polymerizable or crosslinkable material, and it is preferable to use a storage stabilizer that is soluble in the contained droplets or liquid, or other coexisting components.

  Storage stabilizers include quaternary ammonium salts, hydroxyamines, cyclic amides, nitriles, substituted ureas, heterocyclic compounds, organic acids, hydroquinones, hydroquinone monoethers, organic phosphines, copper compounds, and the like. Specific examples include benzyltrimethylammonium chloride, diethylhydroxylamine, benzothiazole, 4-amino-2,2,6,6-tetramethylpiperidine, citric acid, hydroquinone monomethyl ether, hydroquinone monobutyl ether, and copper naphthenate. It is done.

  The amount of storage stabilizer added is preferably adjusted as appropriate based on the activity of the polymerization initiator, the polymerizability of the polymerizable or crosslinkable material, and the type of storage stabilizer, but the balance between storage stability and curability is balanced. In terms of solid content in the liquid, 0.005 to 1% by mass is preferable, 0.01 to 0.5% by mass is more preferable, and 0.01 to 0.2% by mass is even more preferable.

~ Conductive salts ~
Conductive salts are solid compounds that improve conductivity. In the present invention, it is preferable not to use it substantially because there is a great concern of precipitation during storage, but it is possible to increase the solubility of conductive salts or use a highly soluble liquid component. If it is good, an appropriate amount may be added.
Examples of the conductive salts include potassium thiocyanate, lithium nitrate, ammonium thiocyanate, dimethylamine hydrochloride and the like.

~solvent~
In the present invention, a solvent other than the high-boiling solvent described above can be used. The solvent can be used for the purpose of improving the polarity and viscosity of liquid (ink), surface tension, solubility and dispersibility of coloring materials, adjusting conductivity, and adjusting printing performance.
Note that the solvent is a water-insoluble liquid and does not contain an aqueous solvent because it is preferable in terms of recording a high-quality image with quick drying and uniform line width. The configuration used is desirable.

  A low boiling point organic solvent that is an organic solvent at 100 ° C. or lower is also exemplified, but there is a concern that the curability is affected, and it is desirable not to use the low boiling point organic solvent in consideration of environmental pollution. When used, it is preferable to use a highly safe solvent, and a highly safe solvent is a solvent having a high management concentration (an index indicated by the work environment evaluation criteria), preferably 100 ppm or more, More preferably, it is 200 ppm or more. Specific examples include alcohols, ketones, esters, ethers, hydrocarbons, and the like, and specific examples include methanol, 2-butanol, acetone, methyl ethyl ketone, ethyl acetate, and tetrahydrofuran.

  Solvents can be used in combination other than one kind alone, but when water and / or a low-boiling organic solvent is used, the amount of both used is preferably 0 to 20% by mass in each solution. 10 mass% is still more preferable, and it is preferable not to contain substantially. When water is contained in the first liquid A and the second liquid B according to the present invention, the stability over time such as non-uniformity over time, turbidity of the liquid due to precipitation of dye, etc., and non-penetration From the viewpoint of dryness when a recording medium having low permeability or slow permeability is used. In addition, it does not contain substantially means accepting presence of an inevitable impurity.

~ Other additives ~
Furthermore, known additives such as polymers, surface tension adjusters, ultraviolet absorbers, antioxidants, anti-fading agents and pH adjusters can be used in combination.
Regarding the surface tension adjusting agent, ultraviolet absorber, antioxidant, anti-fading agent, and pH adjusting agent, known compounds may be appropriately selected and used. For example, JP-A-2001-181549 discloses a specific example. The additives described can be used.

In addition to the above, each of the first liquid A and the second liquid B according to the present invention contains a pair of compounds that react by mixing to form aggregates or thicken, respectively. Can do. The set of compounds has a feature of rapidly forming aggregates or rapidly thickening the liquid, thereby more effectively suppressing coalescence between adjacent droplets. Can do.
Examples of the reaction of the set of compounds include an acid / base reaction, a hydrogen bonding reaction with a carboxylic acid / amide group-containing compound, a crosslinking reaction represented by boronic acid / diol, and a reaction by electrostatic interaction with a cation / anion. Etc.

Next, the ink jet recording method of the present invention will be described in detail.
In the ink jet recording method of the present invention, a recording medium is used in advance by using the ink set for ink jet recording of the present invention and applying the second liquid B to the same or wider range than the image formed by the first liquid A. To give to. By using the ink set for ink-jet recording of the present invention, it is possible to avoid dispersion destruction caused by shock when the two droplets that have been ejected collide and mix with each other. In addition, it is possible to record high-quality images without color blur.
In addition, since the second liquid B is applied to the recording medium in advance before the first liquid A is deposited, droplets of the first liquid A (for example, the droplet a1 and the droplet a2) are formed. Even if they are applied with overlapping parts, it is possible to suppress the unification between the droplets, for example, the droplet a1 and the droplet a2, and the effect of blurring of the image and generation of line width variations such as fine lines in the image is effective. Therefore, sharp lines can be formed with a uniform width while ensuring a high image density image resolution, and a high-quality image can be recorded. Moreover, there is no stickiness and it is excellent also in abrasion resistance, light resistance, and ozone resistance. This is particularly effective when the sp value of the liquid B is 35 or less (preferably 30 or less) and the difference in sp value from the liquid A is 10 or less.

  In the present invention, as the liquid for forming the image, the first liquid A including the first droplet a1 and the droplet a2 and the second liquid B having a composition different from the first liquid A are used. Here, the first droplet a1 and the droplet a2 are droplets in droplets a1, a2, a3,... Nx that are ejected from the ink ejection port using the single first liquid A. In this case, preferably, the droplets are ejected in an overlapping manner. The droplets may be droplets that are ejected at the same time, or may be the preceding droplet and the succeeding droplet that are the relationship between the preceding droplet and the subsequent droplet, and may be the preceding droplet and the subsequent droplet. preferable.

  More preferably, when forming a desired image by discharging the first liquid droplet a1, the liquid droplet a2,... By the first liquid A from the ink discharge port (head) in the ink jet printer, the liquid A is formed. After the first droplet a1 is ejected, the subsequent first droplet a2 is ejected so as to overlap with the droplet a1 previously ejected.

  In the ink jet recording method of the present invention, the first droplet a1 and the droplet a2 described above are ejected using an ink jet nozzle or the like, and the ink jet nozzle is not necessarily used for the second liquid B. The application is not limited to spraying but can be applied by other means such as coating.

  Next, an application unit for applying the second liquid B onto the recording medium will be described. The droplet ejection means for ejecting the first droplet a1 and the droplet a2 (first liquid A) will be described focusing on the ejection using the inkjet nozzle as described above. A specific example is shown below.

(I) Coating using a coating device Using the coating device, the second liquid B is coated on the recording medium, and then droplets a1 and a2 (first liquid A) are ejected by an inkjet nozzle. A mode in which an image is recorded by dropping is suitable.

The coating apparatus is not particularly limited and can be appropriately selected from known coating apparatuses according to the purpose, for example, an air doctor coater, a blade coater, a lot coater, a knife coater, a squeeze coater, an impregnation coater, Examples include reverse roll coaters, transfer roll coaters, gravure coaters, kiss roll coaters, cast coaters, spray coaters, curtain coaters, and extrusion coaters. For details, see Yuji Harasaki's “Coating Engineering”.
The ink jet nozzle is not particularly limited and can be appropriately selected from known nozzles according to the purpose. The ink jet recording method will be described later.

  It should be noted that other liquids other than the first liquid droplet a1 and the liquid droplet a2 (first liquid A) and the second liquid B may be used. It may be applied on the recording medium by any method such as jetting by the above, and the timing of application is not particularly limited. In the case of containing a colorant, it is preferable to spray by an ink jet nozzle, and it is preferable to apply after applying the second liquid B.

(Ii) Injection by inkjet nozzle The second liquid B is ejected by the inkjet nozzle as the second droplet b1, droplet b2, droplet b3,... Droplet bx, and then the first liquid A is injected. A mode in which an image is recorded by ejecting droplets a1, droplets a2, droplets a3,..., Droplet ax (first liquid A) with an inkjet nozzle is suitable. The ink jet nozzle is the same as described above.

  In this case as well, for any liquid other than the first liquid droplet a1 and the liquid droplet a2 (first liquid A) and the second liquid B, any method such as coating by a coating device or jetting by an inkjet nozzle may be used. And may be applied on the recording medium, and the timing of application is not particularly limited. In the case of containing a colorant, it is preferable that the colorant is injected by an ink jet nozzle, and it is preferable that the second liquid B is applied after being injected from the nozzle.

Next, an ejection method (inkjet recording method) using an inkjet nozzle will be described.
In the present invention, for example, a charge control method that ejects ink using electrostatic attraction, a drop-on-demand method (pressure pulse method) that uses the vibration pressure of a piezo element, and an electric signal is converted into an acoustic beam into ink. Known systems such as an acoustic ink jet system that irradiates and discharges ink using radiation pressure, and a thermal ink jet (bubble jet (registered trademark)) system that uses ink to form bubbles by heating ink and generate pressure Is preferred.
Inkjet recording methods include a method of ejecting a large number of low-density inks called photo inks in a small volume, a method of improving image quality using a plurality of inks having substantially the same hue and different densities, and colorless and transparent inks. The method using is included.

  In the case of the applying means (i), at least the first droplet a1 and the first droplet a2 are ejected onto the second liquid B previously applied on the recording medium by the ink jet recording method. An image is formed. In the case of using the applying means (ii), at least the first liquid droplet a1 and the first liquid droplet a2 are further ink-jetted on the second liquid B previously applied onto the recording medium by the ink jet recording method. The droplets are ejected by the recording method to form an image.

  In the present invention, since the droplet a1 and the droplet a2 have an overlapping portion, the number of droplet ejection per unit length increases, and higher-resolution image recording is possible. At this time, it is preferable that the first liquid droplet a1 and the liquid droplet a2 are ejected within 1 second or less after the second liquid B is applied to the recording medium.

The overlapping rate when droplets are ejected with an overlapping portion is an overlapping rate at least one second after the droplets a1 and a2 overlap and are ejected, and in particular the first droplet a1 is ejected. It is preferable that droplets are ejected such that the overlapping rate at the overlapping portion after 1 second from the droplets of the first droplet a2 after the droplets is 10% or more and 90% or less. It is effective for higher resolution image recording.
Among these, the overlapping rate is preferably 20% or more and 80% or less, and more preferably 30% or more and 70% or less.

  The overlapping rate is an index indicating at what rate the adjacent droplets (droplet a1, droplet a2,...) Overlap. Assuming that the diameter of the droplet after landing on the recording medium is a, the overlapping rate is 50% when ½a overlaps. In the case of the present invention, adjacent droplets that are ejected adjacently can maintain the droplet ejection shape without being united with each other, but the overlapping rate is defined as b being the radius of the droplet one second after droplet ejection. When the interval between adjacent droplets is c, 100 × (2b−c) / 2b [%].

  Moreover, there is no restriction | limiting in particular in the ejection amount of 1st droplet a1 and 1st droplet a2, It can select according to the sharpness of a recorded image. Generally, about 0.5 pl to 10 pl per droplet is preferable. Further, the application of the second liquid B is not particularly limited as long as it can be applied to the same region as the image formed by the first droplet a1 and the droplet a2 or a region wider than the image. .

  At the time of image recording, the amount of the droplet a1 or the droplet a2 is set to 1 as the balance of the application amount of the second liquid B per one droplet of the first droplet a1 and the first droplet a2. In this case, the application amount (mass ratio) of the second liquid B is preferably in the range of 0.05 to 5, more preferably in the range of 0.07 to 1, and particularly preferably in the range of 0.1 to 1.

  The first liquid A including the first droplet a1 and the droplet a2 is ejected with a droplet size of 0.1 pL (picoliter; the same applies hereinafter) to 100 pL (preferably by an inkjet nozzle). Is preferred. When the droplet size is within the above range, it is effective in that an image having a high sharpness can be drawn with a density. More preferably, it is 0.5 pL or more and 50 pL or less.

  Moreover, it is preferable that the droplet ejection interval after the application of the second liquid B until the droplet a1 of the first liquid A is deposited is in the range of 5 μs or more and 400 milliseconds or less. It is effective in that the effect of the present invention can be remarkably exhibited when the droplet ejection interval is within the above range. The droplet ejection interval is more preferably 10 μs or more and 300 ms or less, and particularly preferably 20 μs or more and 200 μs or less.

(Physical properties of liquid A and liquid B)
The physical properties of the first liquid A (droplet) and the second liquid B (droplet) ejected onto the recording medium by the ink jet recording method differ depending on the apparatus, but generally the viscosity at 25 ° C., respectively. Is preferably in the range of 5 to 100 mPa · s, more preferably 10 to 80 mPa · s.

The liquid A and the liquid B included in the ink set for ink jet recording of the present invention preferably contain a surfactant from the viewpoint of forming a liquid A dot having a desired size on the recording medium. It is preferable to satisfy all of the following conditions (A), (B), and (C).
(A) The surface tension of the liquid B is smaller than the surface tension of any liquid A included in the ink set for ink jet recording.
(B) At least one of the surfactants contained in the liquid B is
γs (0) −γs (saturated)> 1 mN / m
Satisfy the relationship.
(C) The surface tension of the liquid B is
γs <(γs (0) + γs (saturation) maximum) / 2
Satisfy the relationship.

  Here, γs is the value of the surface tension of the liquid B. γs (0) is the value of the surface tension of the liquid B excluding all the surfactants. γs (saturation) is obtained when one surfactant among the surfactants contained in liquid B is added to the “liquid excluding all surfactants” and the concentration of the surfactant is increased. It is the value of the surface tension of the liquid that saturates. The γs (saturation) maximum is the maximum value of γs (saturation) obtained for all the surfactants satisfying the condition (B) among the surfactants contained in the liquid B.

<Condition (A)>
In the present invention, as described above, in order to form a liquid A dot having a desired size on a recording medium, the surface tension γs of the liquid B is set to be any of the liquids A included in the ink set for ink jet recording. The surface tension is preferably smaller than γk.
Further, from the viewpoint of more effectively preventing the expansion of the liquid A dot from the landing to the exposure, γs <γk-3 (mN / m) is more preferable, and γs <γk-5 (mN / m) is particularly preferable. preferable.
Further, when printing a full-color image, from the viewpoint of improving the sharpness of the image, the surface tension γs of the liquid B may be set to be smaller than the surface tension of the liquid A containing at least a colorant having high visibility. More preferably, it is less than the surface tension of all the liquids A contained in the ink set for inkjet recording. Note that the colorant having high visibility includes a magenta, black, or cyan colorant.
In addition, even if the values of the surface tension γk of the liquid A and the surface tension γs of the liquid B satisfy the above relationship, if both values are less than 15 mN / m, it is difficult to form droplets during ink jet ejection. In some cases, non-ejection may occur. On the other hand, if it exceeds 50 mN / m, the wettability with the ink jet head may be deteriorated, resulting in a problem of non-ejection. Therefore, from the viewpoint of proper discharge, the surface tension γk of the liquid A and the surface tension γs of the liquid B are preferably 15 mN / m or more and 50 mN / m or less, more preferably 18 mN / m or more and 40 mN / m or less, and 20 mN / m. Above 38 mN / m is particularly preferable.
Here, the surface tension is measured by a Wilhelmy method using a commonly used surface tension meter (for example, Kyowa Interface Science Co., Ltd., surface tension meter CBVP-Z, etc.) at a liquid temperature of 20 ° C. and 60% RH. It is the value measured by.

<Condition (B) and Condition (C)>
In the present invention, in order to form an ink dot of a desired size on a recording medium, the liquid B preferably contains at least one kind of surfactant. In this case, at least one of the surfactants contained in the liquid B preferably satisfies the following condition (B).
γs (0) −γs (saturation)> 1 mN / m Condition (B)
Furthermore, the surface tension of the liquid B preferably satisfies the relationship of the following condition (C).
γs <(γs (0) + γs (saturation) maximum) / 2 ... condition (C)

  As described above, γs is the value of the surface tension of the liquid B. γs (0) is the value of the surface tension of the liquid B excluding all the surfactants. γs (saturation) is obtained when one surfactant among the surfactants contained in liquid B is added to the “liquid excluding all surfactants” and the concentration of the surfactant is increased. It is the value of the surface tension of the liquid that saturates. The γs (saturation) maximum is the maximum value of γs (saturation) obtained for all surfactants satisfying the condition (B) among the surfactants contained in the liquid B.

  The γs (0) can be obtained by measuring the surface tension value of the liquid B excluding all the surfactants. The γs (saturation) is obtained by adding one surfactant among the surfactants contained in the liquid B to the “liquid excluding all surfactants” and setting the surfactant concentration to 0. It is obtained by measuring the surface tension of the liquid when the amount of change in surface tension becomes 0.01 mN / m or less when it is increased by 01% by mass.

The γs (0), γs (saturated), and γs (saturated) maximum will be specifically described below.
For example, the component constituting the liquid B (Example 1) is a high boiling point solvent (diethyl phthalate, manufactured by Wako Pure Chemical Industries, Ltd.), a polymerization initiator (TPO-L, the following initiator-1), a fluorine-based solvent. When a surfactant (Megafac F475, manufactured by Dainippon Ink & Chemicals, Inc.) or a hydrocarbon surfactant (di-2-ethylhexyl sodium sulfosuccinate) is used, γs (0), γs (saturated) ¹ ( The maximum values of γs (saturated) ² (when a hydrocarbon surfactant is added), γs (saturated), and γs (saturated) are as follows.

That is, γs (0) is the surface tension value of the liquid B excluding all the surfactants, and is 36.7 mN / m. Further, when the saturation value of the surface tension of the liquid when a fluorine-based surfactant is added to the liquid and the concentration is increased is γs (saturated) ¹ , the value is 20.2 mN / m. Similarly, when a hydrocarbon surfactant is added to the liquid and the concentration is increased, the saturation value of the surface tension of the liquid is γs (saturated) ^2, and the value is 30.5 mN / m. It becomes.

Since the liquid B (Example 1) contains two kinds of surfactants that satisfy the condition (B), γs (saturated) is carbonized when the fluorosurfactant is added (γs (saturated) ¹ ). Two values (γs (saturated) ² ) can be taken when the hydrogen-based surfactant is added. From these, the γs (saturation) maximum is the maximum value of the γs (saturation) ¹ and γs (saturation) ² , and thus becomes the value of γs (saturation) ² .
From the above, they are summarized as follows.
γs (0) = 36.7 mN / m
γs (saturated) ¹ = 20.2 mN / m (when a fluorosurfactant is added)
γs (saturated) ² = 30.5 mN / m (when a hydrocarbon-based surfactant is added)
γs (saturation) maximum = 30.5 mN / m

From the above results, the surface tension γs of the liquid B is
γs <(γs (0) + γs (saturation) maximum) /2=33.6 mN / m
It is preferable to satisfy the relationship.
Regarding the condition (C), from the viewpoint of more effectively preventing the expansion of ink droplets from landing to exposure, the surface tension of the liquid B is as follows:
γs <γs (0) −3 × {γs (0) −γs (saturated)} / 4
It is more preferable to satisfy the relationship
γs ≦ γs (saturated)
It is particularly preferable to satisfy this relationship.

  Here, the surface tension was measured at a liquid temperature of 20 ° C. by the Wilhelmy method using a commonly used surface tension meter (for example, Kyowa Interface Science Co., Ltd., surface tension meter CBVP-Z, etc.). Value.

~ Surfactant ~
In the present invention, as described above, the liquid B preferably contains at least one surfactant in order to form ink dots of a desired size on the recording medium.
In the present invention, the surfactant is hexane, cyclohexane, p-xylene, toluene, ethyl acetate, methyl ethyl ketone, butyl carbitol, cyclohexanone, triethylene glycol monobutyl ether, 1,2-hexanediol, propylene glycol monomethyl ether, isopropanol, It is a substance having strong surface activity against at least one solvent among methanol, water, isobornyl acrylate, 1,6-hexane diacrylate, and polyethylene glycol diacrylate, preferably hexane, toluene, propylene glycol monomethyl ether , Isobornyl acrylate, 1,6-hexane diacrylate, and polyethylene glycol diacrylate have strong surface activity against at least one solvent More preferably, it is a substance having strong surface activity against at least one kind of solvent among propylene glycol monomethyl ether, isobornyl acrylate, 1,6-hexane diacrylate, and polyethylene glycol diacrylate, and particularly preferable. Is a substance having a strong surface activity against at least one solvent among isobornyl acrylate, 1,6-hexane diacrylate, and polyethylene glycol diacrylate.

Whether or not a certain compound has a strong surface activity with respect to the solvents listed above can be determined by the following procedure.
(procedure)
One solvent is selected from the solvents listed above, and the surface tension γ (0) solvent of the solvent is measured. When the compound is added to the same solution as the solvent for which the γ (0) solvent was obtained, the concentration of the compound is increased by 0.01% by mass, and the change in the surface tension becomes 0.01 mN / m or less The surface tension γ (saturated) solvent of the solution is measured. The relationship between the γ (0) solvent and the γ (saturated) solvent is
γ (0) solvent-γ (saturated) solvent> 1 mN / m
If so, the compound is judged to be a substance having a strong surface activity with respect to the solvent.

  Specific examples of the surfactant contained in the liquid B include anionic surfactants such as dialkylsulfosuccinates, alkylnaphthalenesulfonates, fatty acid salts, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, Nonionic surfactants such as acetylene glycols and polyoxyethylene / polyoxypropylene block copolymers, cationic surfactants such as alkylamine salts and quaternary ammonium salts, and fluorosurfactants. In addition, examples of the surfactant include those described in JP-A Nos. 62-173463 and 62-183457.

In the present invention, after the second liquid B is applied in advance as described above and the first droplet a1 and the droplet a2 are subsequently deposited, energy is obtained from the viewpoint of obtaining excellent fixability. A step of fixing the recorded image by applying can be provided. By applying energy, a curing reaction by polymerization or crosslinking of the polymerizable or crosslinkable material contained therein can be promoted, and a stronger image can be formed more efficiently. For example, in a system including a polymerization initiator, generation of active species due to decomposition of the polymerization initiator is promoted by application of active energy such as actinic light and heating, and due to the increase of active species and temperature rise, the result is due to the active species. The curing reaction by polymerization or crosslinking of the polymerizable or crosslinkable material is accelerated.
The application of energy can be suitably performed by irradiation with active light or heating.

Examples of the active light include ultraviolet rays and visible rays, as well as α rays, γ rays, X rays, electron rays, and the like. Among these, ultraviolet rays and visible rays are preferably used from the viewpoint of cost and safety, and ultraviolet rays are particularly preferred.
The amount of energy required for the curing reaction varies depending on the type and content of the polymerization initiator, but is generally about 1 to 500 mJ / cm ² .

In addition, when energy is applied by heating, it is preferable to heat for 0.1 to 1 second under the condition that the surface temperature of the recording medium is in a temperature range of 40 to 80 ° C.
Heating can be performed using a non-contact type heating means, such as a heating means for passing through a heating furnace such as an oven, a heating means by full exposure of ultraviolet light to visible light to infrared light, etc. are suitable. It is. Examples of light sources suitable for exposure as the heating means include metal halide lamps, xenon lamps, tungsten lamps, carbon arc lamps, mercury lamps and the like.

  In the present invention, it is possible to include a step of curing with the actinic ray between the droplets of the second liquid B and the first liquid A, but the droplets of the first liquid A are started. In the meantime, it is desirable to keep the second liquid B previously applied to the recording medium in a liquid state. Therefore, it is preferable that the second liquid B is not cured at all or semi-cured.

-Recording medium-
In the inkjet recording method of the present invention, any of a permeable recording medium, a non-permeable recording medium, and a slowly permeable recording medium can be used as a recording medium. Among these, a non-permeable or slowly permeable recording medium is preferable from the viewpoint of more remarkable effects of the present invention.

  When an image is recorded on a recording medium with low liquid absorbency, conventionally, adjacent droplets (ink A and ink B) applied so as to overlap each other stay on the medium and come into contact before drying. If the image is blurred and mixed, the line width of the thin line is non-uniform, and the end of the image is swelled, but the end is not uniform. When the second liquid B is ejected in advance in the same area or wider than the area, the liquid A droplets are applied when they overlap each other. Since the unity between the two is suppressed, it is possible to effectively prevent the line width variation of the fine line in the droplet-formed image, the distortion of the lattice line, and the unevenness due to the expansion of the image end. As a result, it is possible to record a high-quality image with no blur and fine line quality (including line width uniformity) and a uniform edge of the image. In addition, there is no stickiness and excellent scratch resistance.

  Here, the permeable recording medium is a medium in which when a 10 pl (picoliter) droplet is dropped on the recording medium, the time until the entire liquid amount permeates is 100 milliseconds or less. Examples of the paper include plain paper and porous paper. The non-permeable recording medium refers to a medium in which droplets do not substantially permeate, and examples thereof include a medium using synthetic resin or glass. “Substantially does not penetrate” means that the penetration rate of a droplet after 1 minute is 5% or less. Further, the slow-penetrating recording medium refers to a medium in which when a 10 pl droplet is dropped onto a recording medium, the time until the total liquid permeates is 100 ms or more. For example, paper. Details of the non-permeable or slowly permeable recording medium will be described later.

Examples of the permeable recording medium include plain paper, porous paper, and other media that can absorb liquid.
Examples of the non-permeable or slowly permeable recording medium include art paper, synthetic resin, rubber, resin-coated paper, glass, metal, earthenware, and wood. In addition, for the purpose of adding a function, a base material obtained by combining a plurality of these materials can be used.

  As the synthetic resin, any synthetic resin can be used. For example, polyesters such as polyethylene terephthalate and polybutadiene terephthalate, polyolefins such as polyvinyl chloride, polystyrene, polyethylene, polyurethane, and polypropylene, acrylic resins, polycarbonates, and acrylonitrile-butadiene. -Styrene copolymer etc., Diacetate, Triacetate, Polyimide, Cellophane, Celluloid etc. are mentioned. When the synthetic resin is used, the thickness and shape may be any of a film shape, a card shape, and a block shape, and are not particularly limited, and may be either transparent or opaque.

  The synthetic resin is preferably used in the form of a film used for so-called soft packaging, and various non-absorbable plastics and films thereof can be used. Examples of the plastic film include a PET film, an OPS film, an OPP film, a PNy film, a PVC film, a PE film, and a TAC film. Other plastics that can be used include polycarbonate, acrylic resin, ABS, polyacetal, PVA, and rubbers.

  Examples of the resin-coated paper include a transparent polyester film, an opaque polyester film, an opaque polyolefin resin film, and a paper support in which both sides of paper are laminated with a polyolefin resin. Particularly preferred is a paper support in which both sides of the paper are laminated with a polyolefin resin.

  There is no restriction | limiting in particular as said metal, For example, aluminum, iron, gold | metal | money, silver, copper, nickel, titanium, chromium, molybdenum, silicon | silicone, lead, zinc etc., or stainless steel etc., and these composite materials are suitable. .

  Further, a read-only optical disk such as a CD-ROM or DVD-ROM, a write-once optical disk such as a CD-R or DVD-R, a rewritable optical disk, or the like can also be used. And a gloss-imparting layer.

  Details of the first liquid A (droplets a1, a2,...) And the second liquid B used in the ink jet recording method of the present invention and the various components constituting them are as described above.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist thereof. Unless otherwise specified, “part” is based on mass.

Example 1
<Preparation of magenta pigment dispersion P-1>
PV19 (Hostaparm RED E5B02, manufactured by Clariant) 8 g, 56 g of bis {[1-ethyl (3-oxetaniel)] methyl} ether (OXT-221; manufactured by Toagosei Co., Ltd.), and 16 g of BYK-168 (manufactured by BYK Chemie) Were mixed and stirred with a stirrer for 1 hour. The mixture after stirring was dispersed with an Eiger mill to obtain a magenta pigment dispersion P-1.
Here, dispersion conditions were such that zirconia beads having a diameter of 0.65 mm were filled at a filling rate of 70%, the peripheral speed was 9 m / s, and the dispersion time was 1 hour.

<Preparation of Ink Liquid I-1 for Inkjet Recording Containing Magenta Pigment>
Inks for inkjet recording I-1 (Liquid A) were prepared by stirring, mixing and dissolving the components having the following composition. The sp value of the ink liquid I-1 for inkjet recording was 18, and the surface tension was 32 N / m.
<composition>
・ Magenta pigment dispersion P-1 above 3.75 g
・ Bis {[1-ethyl (3-oxetaniel)] methyl} ether: 0.825 g
1-methyl-4- (2-methyloxiranyl) -7-oxabicyclo [4.1.0] heptane (Cel3000, manufactured by Daicel-Cytec Corp.) ... 8.925 g
-The following polymerization initiator-2 ... 1.5g
(Irg250, manufactured by Ciba Specialty Chemicals)

  As described above, the sp value was calculated by the sp value calculation program by R.L.smith (Tohoku University) (25 ° C.). The same applies hereinafter. However, the compound containing no carbon atom was excluded from the calculation, and the structural unit such as a polymer or polyethylene chain was a saturated repeating unit having a bond, and water was calculated as 47.8.

<Preparation of pigment dispersion>
(Preparation Example 1)
6 g of pigment (PV19, Hostaparm RED E5B02, manufactured by Clariant) was dissolved in a solution obtained by mixing dimethyl sulfoxide and 8 mol / L (liter: same below) aqueous potassium hydroxide solution in a ratio of 6: 1 to 150 mmol / L. A pigment solution A1 was prepared.
Next, methacrylic acid / benzyl methacrylate copolymer (= 28/72 [molar ratio], weight average molecular weight: 30,000, 40% 1-methoxy-2-propyl acetate solution) 2.0 g, pigment dispersant A0 shown below .6 g and 18 g of a dispersant polyvinylpyrrolidone (manufactured by Wako Pure Chemical Industries, Ltd., K30, molecular weight 40,000) were dissolved to prepare 50 ml of 1-methoxy-2-propyl acetate solution B1.
Separately from this, water was prepared as a poor solvent.

  Here, the above pigment was added to 1000 ml of poor solvent water which was temperature-controlled at 1 ° C. and stirred at 500 rpm by GK-0222-10 type Lamond Stirrer manufactured by Fujisawa Pharmaceutical Co., Ltd. 200 ml of solution A1 was injected at a flow rate of 50 ml / min using NP-KX-500 large capacity non-pulsating flow pump manufactured by Nippon Seimitsu Co., Ltd., and at the same time, the 1-methoxy-2-propyl acetate solution B1 was added. Pigment particles were formed by injecting 100 ml at a flow rate of 25 ml / min using an NP-KX-500 large capacity non-pulsating flow pump manufactured by Nippon Seimitsu Co., Ltd., and a pigment particle reprecipitation liquid was prepared.

  Unnecessary ions and organic solvents are removed from the prepared pigment particle reprecipitation liquid (pigment particle concentration: about 0.5 mass%) by using an ultrafilter, and the solvent is bis {[1-ethyl (3-oxetaniel) ] Methyl} ether (OXT-221, manufactured by Toagosei Co., Ltd.) and replaced with 60 ml of pigment particle dispersion composition 1 (pigment particle concentration of about 10.0% by mass; dispersion of organic material particles according to the present invention) Obtained.

(Preparation Example 2)
In Preparation Example 1, 60 ml of pigment particle dispersion was performed in the same manner as in Preparation Example 1 except that 18 g of the polyvinylpyrrolidone dispersant used for the preparation of the 1-methoxy-2-propyl acetate solution B1 was replaced with 18 g of polyacrylamide. A composition 2 (pigment particle concentration of about 10.0% by mass; dispersion of organic material particles according to the present invention) was obtained.

(Preparation Example 3)
In Preparation Example 1, 60 ml of pigment particle dispersion was performed in the same manner as in Preparation Example 1, except that 18 g of the polyvinylpyrrolidone dispersant used for the preparation of the 1-methoxy-2-propyl acetate solution B1 was replaced with 18 g of polyethyleneimine. Composition 3 (pigment particle concentration of about 10.0% by mass; dispersion of organic material particles according to the present invention) was obtained.

<Preparation of ink liquids I-2 to I-4 for inkjet recording containing magenta pigment>
In the preparation of the ink liquid I-1 for ink jet recording, the ink jet recording was performed except that the magenta pigment dispersion P-1 was replaced with the pigment particle dispersion compositions 1, 2, and 3 obtained in Preparation Examples 1 to 3, respectively. Ink liquids I-2 to I-4 (liquid A) for ink jet recording containing a magenta pigment were prepared in the same manner as the ink liquid I-1. The sp value and surface tension of the ink liquids I-2 to I-4 for inkjet recording are shown in Table 1 below.

<Preparation of inkjet recording ink liquid II-1 containing cyan pigment>
In the preparation of the ink liquid I-1 for inkjet recording, PV19 (Hostaparm RED E5B02, manufactured by Clariant) used for the preparation of the magenta pigment dispersion P-1 was mixed with PB15: 3 (IRGALITE BLUE GLO; Inkjet recording ink liquid II-1 containing a cyan pigment was prepared in the same manner as the inkjet recording ink liquid I-1, except that each was replaced with Ciba Specialty Chemicals). The sp value and surface tension of the ink liquid II-1 for ink jet recording are shown in Table 1 below.

<Preparation of Ink Liquid III-1 for Inkjet Recording not Containing Pigment>
Components of the following composition were mixed by stirring and dissolved to prepare ink liquid III-1 for ink jet recording. Ink liquid III-1 for inkjet recording had an sp value of 19 and a surface tension of 23 mN / m.
<composition>
・ Bis {[1-ethyl (3-oxetaniel)] methyl} ether ... 4.18 g
1-methyl-4- (2-methyloxiranyl) -7-oxabicyclo [4.1.0] heptane (Cel3000, manufactured by Daicel-Cytec Corp.) ... 9.77 g
・ 9,10-Dibutoxyanthracene ・ ・ ・ 0.75g
・ Megafuck F475 (Dainippon Ink Chemical Co., Ltd.) ・ ・ ・ 0.3g

<Preparation of one-liquid type comparative ink liquids I′-1 to I′-4 and II′-1 for inkjet recording>
Components of the following composition are stirred and mixed to dissolve, and comparative ink liquids I′-1, I′-2, I′-3, I′-4 for ink jet recording containing a one-component magenta pigment, and a one-component type Comparative Ink Liquid II′-1 for inkjet recording containing the cyan pigment was prepared.
1) Comparative ink liquid I′-1 for inkjet recording containing a one-component magenta pigment
Components of the following composition were stirred and mixed and dissolved to prepare a comparative ink liquid I′-1 for inkjet recording containing a magenta pigment. The comparative ink liquid I′-1 had an sp value of 19 and a surface tension of 32 N / m.
<composition>
・ Magenta pigment dispersion P-1 above 3.75 g
・ Bis {[1-ethyl (3-oxetaniel)] methyl} ether: 0.6 g
1-methyl-4- (2-methyloxiranyl) -7-oxabicyclo [4.1.0] heptane (Cel3000, manufactured by Daicel Cytec Co., Ltd.) 8.4 g
・ Polymerization initiator-2 ... 1.5g
(Irg250, manufactured by Ciba Specialty Chemicals)
・ 9,10-Dibutoxyanthracene: 0.75g

2) Comparative ink liquids I′-2 to I′-4 for inkjet recording containing a one-component magenta pigment
Except for replacing the magenta pigment dispersion P-1 used for the preparation of the comparative ink liquid I′-1 for inkjet recording with the pigment particle dispersion compositions 1, 2, and 3 obtained in Preparation Examples 1 to 3, respectively. Comparative ink liquids I′-2 to I′-4 for inkjet recording containing a magenta pigment were prepared in the same manner as the comparative ink liquid I′-1 for inkjet recording.

3) Comparative ink II′-1 for inkjet recording containing a one-component cyan pigment
In the preparation of the comparative ink liquid I′-1 for inkjet recording, PV19 (Hostaparm RED E5B02, manufactured by Clariant) used for the preparation of the magenta pigment dispersion P-1 was mixed with PB15: 3 (IRGALITE BLUE) of the same mass as this. GLO (manufactured by Ciba Specialty Chemicals) was prepared in the same manner as the above-described comparative ink liquid I′-1 for ink jet recording, except that it was replaced with Ciba Specialty Chemicals Co., Ltd. did.

  Table 1 below shows the SP value, surface tension, average particle size of pigment particles in the ink liquid, and coefficient of variation of the pigment particles in the ink liquid obtained from the above.

<Image recording and evaluation>
The prepared ink liquids I-1, II-1, and III-1 for ink jet recording were applied to an ink jet printer (Toshiba Tech Head (CA3) mounting jig: droplet ejection frequency: 4.8 KHz, nozzle number: 318, nozzle density: 150 npi ( Nozzle / inch), drop size: Two variable heads are arranged in 7 stages between 6 to 42 pl (picoliter), and 4 sets of 300 npi headsets are loaded), and each ink is loaded from 3 headsets Was ejected (42 pl) and drawn uniformly over the entire surface of the recording medium to produce an image sample. At this time, a polyethylene terephthalate (PET) sheet (trade name: PPL / Xerox film for laser printers, manufactured by Fuji Xerox Co., Ltd .; hereinafter referred to as PET sheet) having a thickness of 60 μm was used as a recording medium.

  The ejection order is the order of ink recording ink liquid III-1 → II-1 → I-1, and the droplet ejection interval when ejecting ink liquid III-1 and ink liquid II-1 is 400 milliseconds, The interval at which ink droplets II-1 and I-1 were ejected was 400 milliseconds. At this time, the conveyance speed is adjusted so that the overlapping rate between the adjacent liquid droplets is 5% for the ink liquid III-1, and the adjacent liquid droplets (liquid liquid) are used for the ink liquids I-1 and II-1. The overlapping ratio between the droplet A1 and the droplet A2 including the droplet a2 is 50%.

  As described above, the overlap rate is 100 × (2b−c) / 2b [%], where b is the radius of the droplet after 1 second after droplet ejection and c is the interval between adjacent droplets. It was calculated by.

After discharging, the image sample was fixed by irradiating with a metal halide lamp at a wavelength of 365 nm with an amount of ultraviolet light of ~ 500 mJ / cm ² . Irradiation was performed 1 second after II-1 droplet ejection.

  Further, the ink liquid I-1 / II-1 for ink jet recording used in the above is a combination I-2 / II-1, I-3 / II-1, I-4 / II- as shown in Table 2 below. The sample was changed to 1 and drawn in the same manner as described above to produce an image sample. Furthermore, without using III-1, I'-1 / II'-1, I'-2 / II'-1, I'-3 / II'-1, I'-4 / II'-1 The image sample was produced by changing and drawing in the same manner as described above.

<Evaluation>
The following evaluation was performed about the produced image sample. The evaluation results are shown in Table 2 below.
-1. Cyan and magenta colors
Each image sample was visually observed, and a case where cyan and magenta ink droplets were mixed together was evaluated as “x”, and a case where each color ink droplet was present independently was evaluated as “◯”.

-2. Cyan density evaluation
Image sample in which III-1 → II-1 was ejected (that is, images produced without performing I-1, I-2, I-3, and I-4, respectively, when the image sample was produced) A sample) was prepared, and compared with the image sample, the difference in cyan density due to the presence or absence of ink droplet I ejection [(cyan density when ink droplet I was deposited) − (ink droplet I was ejected) Cyan density when not present) was measured by X-rite (manufactured by X-rite). The difference in cyan density is shown in Table 2 below.

-3. Evaluation of stickiness −
Immediately after UV irradiation, the image surface (recording surface) of the image sample was touched with a finger and evaluated according to the following evaluation criteria.
<Evaluation criteria>
A: There was no stickiness.
B: Some stickiness was recognized.
C: Significant stickiness was recognized.

-4. Evaluation of scratch resistance
With respect to the drawn PET sheet, a change when the image surface (recording surface) after 30 minutes from ultraviolet irradiation was rubbed 10 times with an eraser was observed and evaluated according to the following evaluation criteria.
<Evaluation criteria>
A: There was no decrease in density due to rubbing.
B: A slight decrease in density due to rubbing was observed.
C: The concentration was remarkably reduced by rubbing.

-5. Evaluation of light resistance
Each image sample was irradiated with xenon light (85,000 Lux) using a weather meter (Atlas C.I65) for 1 week, and the concentration before and after irradiation was measured using a microdensitometer (model name: MICRO-PHOTOMETER MPM-No. 172, manufacturer name: manufactured by Union Optical Co., Ltd.), the dye residual ratio [%] after irradiation was determined, and evaluated in five stages according to the following evaluation criteria. In addition, light resistance evaluation was performed only about the image on a PET sheet.
<Evaluation criteria>
A: The pigment residual ratio was 90% or more.
B: Dye remaining rate was 89-80%.
C: The pigment residual ratio was 79 to 70%.
D: Dye residual ratio was 69 to 50%.
E: Dye remaining rate was less than 49%.

-6. Evaluation of ozone resistance
Each image sample was stored for 1 week under an ozone concentration of 5.0 ppm, and the image density before and after storage was measured using a microdensitometer (model name: MICRO-PHOTOMETER MPM-No. 172, manufacturer name: Union Optical Co., Ltd.). The dye residual ratio (%) after storage was determined and evaluated according to the following evaluation criteria. The ozone resistance was evaluated only for the image on the PET sheet.
<Evaluation criteria>
A: The pigment residual ratio was 90% or more.
B: Dye remaining rate was 89-80%.
C: The pigment residual ratio was 79 to 70%.
D: Dye residual ratio was 69 to 50%.
E: Dye remaining rate was less than 49%.

As shown in Table 2, when drawing is performed using the liquid B together with the liquid A for forming an image (the present invention), the color mixing between the two colors can be avoided well, and the present invention is concerned. By using organic material particles, a drop in the color density deposited on the lower side in the case of repeated droplet ejection was suppressed, and good color developability was exhibited.
On the other hand, when a commercially available pigment is dispersed (comparative example) as in the ink liquid I-1 for ink jet recording, when the ink droplets are repeatedly ejected, the color density of the ink droplets dropped is lowered. Good color developability could not be obtained.
Further, the ink liquids I-1, I-2, I-3, I-4, and II-1 for inkjet recording do not cause solidification of the nozzles even when the nozzles are filled with the liquids, and are stable in ejection. However, while it was effective, the one-pack type comparative ink liquids I′-1, I′-2, I′-3, I′-4, and II′-1 were not filled with liquid. It was found that nozzle solidification occurs when the

(Example 2)
In Preparation Example 1 of Example 1, the pigment particle dispersion composition (pigment) was prepared so that the particle size and coefficient of variation of the prepared ink liquid became the values shown in Table 3 below by changing conditions such as the temperature at the time of preparation. The particle concentration of about 10.0% by mass; the dispersion of organic material particles according to the present invention) 4 to 8 is prepared, and the pigment particle dispersion composition 1 used in the ink liquid I-2 for ink jet recording is used as the pigment particle dispersion composition. Ink-jet recording ink liquids IV-1 to IV-5 were prepared in the same manner as the preparation of the ink-jet recording ink liquid I-2 instead of the products 4 to 8.

  Subsequently, in the same manner as in Example 1, image recording was performed using an ink jet printer in the discharge order shown in Table 4 below, and color mixing and cyan density evaluation were performed. The evaluation results are shown in Table 4 below.

  As described above, in the ink liquid of the comparative example containing a pigment having a particle size and a coefficient of variation outside the scope of the present invention, a decrease in cyan density was observed.

(Example 3)
Bis {[1-ethyl (3-oxetaniel)] methyl} ether and 1-methyl-4- (2-methyloxiranyl) used in the preparation of I-1 to I-4 and II-1 of Example 1 Similar to Example 1, except that -7-oxabicyclo [4.1.0] heptane (Cel3000, manufactured by Daicel Cytec Co., Ltd.) was replaced with an equal mass of the following high-boiling organic solvent S-15. Then, an ink liquid was prepared, image recording was performed, color mixing, and cyan density were evaluated. In this example, the same result as in Example 1 was obtained.

It is sectional drawing which shows schematically the preferable embodiment of the manufacturing apparatus used for the manufacturing method of organic material particle | grains. FIG. 2 is an enlarged partial cross-sectional view schematically showing a mixing chamber in a partial cross section as one embodiment of the manufacturing apparatus of FIG. 1. It is an expanded partial sectional view which shows a mixing chamber roughly with a partial cross section as another embodiment of the manufacturing apparatus of FIG. It is sectional drawing which shows schematically another preferable embodiment of the manufacturing apparatus used for the manufacturing method of organic material particle | grains. It is sectional drawing which shows schematically still another preferable embodiment of the manufacturing apparatus used for the manufacturing method of organic material particle. It is explanatory drawing which shows one structural example of the ultrafiltration apparatus used for the manufacturing method of organic material particle | grains.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Container 11a ... Liquid tank (solvent), 11b ... Liquid level 12 ... Stirring blade 13 ... Mixing chamber 14a, 14b ... Supply pipe 14c, 14d ... Supply pipe opening 15 ... Shaft 16 ... Motor 17 ... Casing (mixing chamber wall) )
18 ... hole (circular hole)
19a, 19b ... stirring blade 21 ... container (outer wall of stirring tank)
21a ... stirring tank 22 ... stirring blade 23 ... discharge pipe 24a, 24b, 24c ... supply pipe 25 ... shaft 31, 32, 33 ... supply port 36 ... discharge port 40 ... seal plate 41, 42 ... stirring blade 46 ... external magnet 48 , 49 ... Motor 50 ... Stirrer 81 ... Storage container 82 ... Circulation pump 83 ... Ultrafiltration module 84 ... Replenishment pure measurement flow meter 85 ... Permeate measurement flow meter 86 ... Backwash pump

Claims (14)

An ink set for ink jet recording comprising at least one first liquid A for forming an image and at least one second liquid B having a composition different from that of the first liquid A,
An ink set for inkjet recording, wherein at least one of the liquids A and B contains organic material particles having an average particle size of 50 nm or less and a coefficient of variation in particle size of 50% or less.   The ink set for inkjet recording according to claim 1, wherein the organic material particles are generated by a reprecipitation method.   The organic material particles are mixed at least three kinds of a solution of an organic material dissolved in a good solvent, a poor solvent of the organic material compatible with the good solvent, and a solution containing a polymer dispersant. The ink set for ink jet recording according to claim 1 or 2, wherein the organic material is produced as particles from a mixed solution.   The ink set for ink jet recording according to any one of claims 1 to 3, wherein the organic material is an organic pigment.   The ink set for inkjet recording according to any one of claims 1 to 4, wherein the liquid B does not contain a colorant, or the content of the colorant is less than 1%.   The ink set for ink jet recording according to any one of claims 1 to 5, wherein the liquid A contains a polymerizable or crosslinkable material.   The ink set for inkjet recording according to any one of claims 1 to 6, wherein the liquid B further contains a surfactant.   Using the ink set for ink jet recording according to any one of claims 1 to 7, the second liquid B is recorded in advance in the same or wider range than the image formed with the first liquid A. An ink jet recording method applied to a medium.   9. The image according to claim 8, wherein the liquid A is at least a first droplet a1 and a droplet a2, and the droplet a1 and the droplet a2 are ejected with overlapping portions. The inkjet recording method as described.   The ink jet recording method according to claim 9, wherein an overlapping ratio in the overlapping portion is 10% or more and 90% or less.   The droplet ejection interval until the droplet a1 of the liquid A is ejected after the application of the liquid B is 5 μs or more and 400 ms or less, according to any one of claims 8 to 10. The inkjet recording method as described.   12. The inkjet according to claim 8, wherein a droplet size of the liquid A including the droplets a <b> 1 and a <b> 2 is 0.1 picoliter or more and 100 picoliters or less. Recording method.   The ink jet recording method according to claim 8, wherein the liquid B is held in a liquid state until the liquid A is ejected.   9. The liquid A contains a polymerizable or crosslinkable material, and after the droplet A is deposited, an active energy is applied to the image to polymerize or crosslink the polymerizable or crosslinkable material. 14. The inkjet recording method according to any one of.

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