JP2007084784A - Ink-jet ink, ink-jet ink set and ink-jet recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink-jet ink and ink-jet ink set capable of preventing feathering, bleeding and beading by using an active energy beam-crosslinkable polymer, having sufficient curing sensitivity while including resin fine particles in ink-jet ink, excellent in discharge stability and having sufficient setting property and water resistance and to provide an ink-jet recording method using the ink-jet ink and the ink-jet ink set. <P>SOLUTION: An ink-jet ink containing a colorant, resin microparticles and a polymer, wherein the polymer has a hydrophilic main chain and a plurality of side chains and the polymer is capable of undergoing crosslinking between the side chains by irradiation with active energy beam. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a novel inkjet ink, an inkjet ink set, and an inkjet recording method using them.

  The ink jet recording method is capable of recording high-definition images with a relatively simple apparatus, and has been rapidly developed in various fields. In addition, there are various uses, and a recording medium or an ink-jet ink suitable for each purpose is used.

  In particular, in recent years, recording speed has been greatly improved, and ink jet printers having printing performance that can withstand light printing applications have been developed.

  However, in order to fully draw out the performance of the ink jet printer, an ink jet exclusive paper provided with ink jet ink absorbency is required.

  When recording on recording media with low ink absorption such as art paper or coated paper, or recording media such as plastic film with no ink absorption, bleed that causes inks of different hues to mix on the recording medium and cause color mixing. In the ink jet recording system, there is a problem in providing a variety of recording media.

  In the above problem, an ink for ink jet recording that is cured by irradiation with ultraviolet rays is disclosed (see Patent Document 1). In addition, a so-called non-aqueous ink containing a pigment as a colorant, a triacrylate or higher polyacrylate as a polymerizable material, and having a ketone or alcohol as a main solvent has been proposed (see Patent Document 2). . An aqueous active energy ray-curable ink jet recording ink composition containing a polyurethane compound, a basic compound, a colorant, a water-soluble organic solvent and water containing a group having an active energy ray-curable unsaturated double bond Has been proposed (see Patent Document 3). Furthermore, a water-based inkjet ink comprising a self-dispersing pigment having one or more hydrophilic groups bonded to the surface of pigment particles, an ultraviolet curable monomer made of a vinyl compound, a photopolymerization initiator, and water. It has been proposed (see Patent Document 4). According to these methods, good recording on a non-absorbable recording medium is possible.

  However, if the ink-jet ink contains a photocurable polymer compound that is cured by ultraviolet rays in a sufficient amount for fixing the formed image quality, the solid content in the ink-jet ink becomes too high, and the printed matter such as dot swells There was a problem with the texture. In addition, there is a problem that the irradiation energy of ultraviolet rays necessary for the dots to be cured and fixed on the recording medium is large, and the power consumption of the irradiation device is increased.

  In order to solve this problem, a method has been proposed in which non-photocurable resin fine particles are contained in the inkjet ink in addition to the photocurable resin (see, for example, Patent Document 5). According to the method disclosed in Patent Document 5, stable ejection properties are solved, and it can be expected that the fixability is improved by adding resin fine particles to the ink-jet ink containing the photocurable polymer compound. .

However, by containing non-photocurable resin fine particles in the ink in addition to the photocurable resin, the ink droplets landed on the recording medium are cured by the light shielding effect of ultraviolet rays irradiated by the non-photocurable resin fine particles. It has been found that it causes a new problem of reduced sensitivity.
U.S. Pat. No. 4,228,438 JP-A-5-64667 JP 2002-80767 A JP 2002-275404 A JP 2001-81365 A

  The present invention has been made in view of the above problems, and its purpose is to prevent feathering, bleeding and beading by using an active energy ray-crosslinking polymer, and further to contain resin fine particles in the inkjet ink. However, an object of the present invention is to provide an inkjet ink, an inkjet ink set, and an inkjet recording method using them, which have sufficient curing sensitivity, excellent ejection stability, sufficient fixing properties and water resistance.

  The above object of the present invention is achieved by the following configurations.

  1. It contains at least a coloring material, a polymer compound, and resin fine particles. The polymer compound has a plurality of side chains in the hydrophilic main chain, and can be cross-linked between side chains by irradiation with active energy rays. An ink-jet ink comprising a molecular compound.

  2. 2. The inkjet ink as described in 1 above, wherein the resin fine particles have a glass transition point (Tg) of −30 ° C. or higher and 150 ° C. or lower.

  3. 3. The ink-jet ink as described in 1 or 2 above, wherein the resin fine particles have an average particle size of 10 nm or more and 200 nm or less.

  4). 4. The ink-jet ink according to any one of 1 to 3, wherein the content of the resin fine particles is 5% by mass or more and 200% by mass or less with respect to the color material.

  5. 5. The inkjet ink according to any one of 1 to 4, wherein the resin fine particles are polyurethane resin fine particles.

  6). Any one of the above 1 to 5, wherein the polymer compound is a saponified product having a hydrophilic main chain of polyvinyl acetate, a saponification degree of 77 to 99%, and a polymerization degree of 200 to 4000. The inkjet ink according to item 1.

  7). 7. The inkjet ink according to any one of 1 to 6, wherein the polymer compound has a side chain modification rate of 0.8 mol% or more and 4 mol% or less with respect to the hydrophilic main chain.

  8). 8. The ink-jet ink as described in any one of 1 to 7 above, which contains a water-soluble photopolymerization initiator.

  9. An inkjet ink set comprising two or more types of inkjet inks, wherein at least one of the inkjet inks is the inkjet ink described in any one of 1 to 8 above. set.

  10. 9. An ink jet recording method comprising: discharging the ink jet ink according to any one of 1 to 8 above onto a recording medium;

  11. 10. An ink jet recording method, comprising: discharging the ink jet ink set described in 9 above onto a recording medium;

  12 12. The inkjet recording method according to 10 or 11, wherein the recording medium is a low-absorbency recording medium or a non-absorbent recording medium.

  13. 12. The inkjet recording method according to 10 or 11, wherein the recording medium is plain paper.

  According to the present invention, feathering, bleeding, and beading can be prevented, and even if resin fine particles are contained in the ink-jet ink, it has sufficient curing sensitivity, excellent ejection stability, and sufficient fixability and water resistance. Ink jet ink, ink jet ink set, and ink jet recording method using them can be provided.

  Hereinafter, the best mode for carrying out the present invention will be described in detail.

  The present invention contains at least a coloring material, a polymer compound and resin fine particles, the polymer compound has a plurality of side chains in the hydrophilic main chain, and is crosslinked between the side chains by irradiating active energy rays. An ink-jet ink comprising a bondable polymer compound.

  In the inkjet ink in which the conventional photocurable resin and the resin fine particles described in Patent Document 5 described above coexist, sufficient curing sensitivity of the photocurable resin cannot be obtained due to the ultraviolet shielding effect of the resin fine particles. It was. As a result of the study by the present inventors, instead of the conventional photocurable resin, the hydrophilic main chain has a plurality of side chains and is crosslinked between the side chains by irradiating active energy rays, for example, ultraviolet rays. By using a bondable polymer compound, the above-described problems of the ultraviolet curable ink have been solved. That is, the hydrophilic main chain according to the present invention having high curing sensitivity has a plurality of side chains, and a polymer compound and resin fine particles that can be cross-linked between the side chains by irradiating active energy rays. By using in combination, it was possible to achieve both good bleed resistance and feathering resistance, and sufficient fixability and water resistance.

  Details of the present invention will be described below.

(Active energy ray crosslinkable polymer)
In the inkjet ink of the present invention (hereinafter also simply referred to as ink), the polymer compound has a plurality of side chains in the hydrophilic main chain, and can be cross-linked between the side chains by irradiating active energy rays. And a high molecular compound (hereinafter also referred to as an active energy ray crosslinkable polymer).

  Examples of the polymer compound having a plurality of side chains in the hydrophilic main chain according to the present invention and capable of crosslinking between the side chains by irradiating active energy rays include, for example, saponified polyvinyl acetate, polyvinyl acetal , Polyethylene oxide, polyalkylene oxide, polyvinyl pyrrolidone, polyacrylamide, polyacrylic acid, hydroxyethyl cellulose, methyl cellulose, hydroxypropyl cellulose, or a derivative of the hydrophilic resin, and at least one selected from the group consisting of these copolymers In the hydrophilic resin, modified groups such as a photodimerization type, a photodecomposition type, a photopolymerization type, a photomodification type, and a photodepolymerization type are introduced into the side chain.

  The side chain is preferably nonionic, anionic, or amphoteric (betaine compound), and particularly when combined with an anionic pigment as a colorant, it is preferably nonionic or anionic from the viewpoint of ink storage stability. Preferably it is nonionic.

  The side chain is preferably represented by the following general formula (A).

Formula (A)
P-{(X) m- (B) p- (Y) n}
In the general formula (A), P represents a hydrophilic main chain, and {} represents a side chain. X represents a divalent or higher valent linking group, B represents a crosslinkable group, and Y represents a hydrogen atom or a substituent. m represents an integer of 0 or 1, n represents an integer of 0 or 1, and p represents a natural number of 1 or 2.

  In the hydrophilic main chain, a saponified product of polyvinyl acetate is preferable from the viewpoint of ease of introduction of side chains and handling, and the degree of saponification is preferably 77% or more and 99% or less. Further, the degree of polymerization is preferably 200 or more and 4000 or less, more preferably 200 or more and 2000 or less from the viewpoint of handling, and the effect of the present invention can be more preferably exhibited at 200 or more and 500 or less. If the degree of polymerization is 200 or more, a thickening effect by crosslinking is moderately recognized, and bleeding resistance and feathering resistance are sufficient. When the degree of polymerization is 4000 or less, the discharge performance of the nozzle after a certain period of pause, so-called intermittent discharge performance, is good.

  The modification rate of the side chain with respect to the hydrophilic main chain is preferably 0.8 mol% or more and 4.0 mol% or less, and the reactivity is preferably 1.0 mol% or more and 3.5 mol% or less. More preferable from the viewpoint. If it is 0.8 mol% or more, sufficient crosslinkability is obtained, and if it is 4.0 mol% or less, the crosslink density becomes appropriate, a sufficient cured film can be obtained, and the strength of the film can be maintained.

  As the photodimerization-type modifying group, those having a diazo group, a cinnamoyl group, a stilbazolium group, a stilquinolium group or the like are preferably used. For example, a photosensitive resin described in JP-A-60-129742 (Composition).

  The photosensitive resin described in JP-A-60-129742 is a compound represented by the following general formula (1) in which a stilbazolium group is introduced into a polyvinyl alcohol structure.

In the formula, R ₁ represents an alkyl group having 1 to 4 carbon atoms, and A ⁻ represents a counter anion.

  The photosensitive resin described in JP-A-56-67309 includes a 2-azido-5-nitrophenylcarbonyloxyethylene structure represented by the following general formula (2) in the polyvinyl alcohol structure, or the following general formula. It is a resin composition represented by (3) and having a 4-azido-3-nitrophenylcarbonyloxyethylene structure.

  Further, a modifying group represented by the following general formula (4) is also preferably used.

  In the formula, R represents an alkylene group or an aromatic ring. A benzene ring is preferred.

  As the photopolymerization type modifying group, for example, resins represented by the following general formula (5) shown in JP-A Nos. 2000-181062 and 2004-189841 are preferable from the viewpoint of reactivity.

In the formula, R ₂ represents Me or H, n represents 1 or 2, X represents — (CH ₂ ) _m —COO—, —CH ₂ —COO— or —O—, Y represents an aromatic ring or a single bond, m represents an integer of 0 to 6.

  Moreover, it is also preferable to use the photopolymerization type | mold modified group represented by following General formula (6) described in Unexamined-Japanese-Patent No. 2004-161942 for a conventionally well-known water-soluble resin.

Wherein, R ₃ represents Me or H, R ₄ represents a linear or branched alkylene group having 2 to 10 carbon atoms.

  In the ink of the present invention, it is preferable to add a water-soluble photopolymerization initiator. These compounds may be dissolved or dispersed in a solvent, or may be chemically bonded to the photosensitive resin.

  The water-soluble photopolymerization initiator to be applied is not particularly limited, but 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone (HMPK) is particularly preferable from the viewpoint of mixing property and reaction efficiency. ), Thioxanthone ammonium salt (QTX), and benzophenone ammonium salt (ABQ) are preferable from the viewpoint of miscibility with an aqueous solvent.

  Furthermore, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone (n = 1) represented by the following general formula (7) from the viewpoint of compatibility with the active energy ray-crosslinking polymer. HMPK) and its ethylene oxide adduct (n = 2 to 5) are more preferable.

  In the formula, n represents an integer of 1 to 5.

  Other examples include benzophenones such as benzophenone, hydroxybenzophenone, bis-N, N-dimethylaminobenzophenone, bis-N, N-diethylaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone. Thioxanthones such as thioxatone, 2,4-diethylthioxanthone, isopropylthioxanthone, chlorothioxanthone, and isopropoxychlorothioxanthone. Anthraquinones such as ethyl anthraquinone, benzanthraquinone, aminoanthraquinone and chloroanthraquinone. Acetophenones. Benzoin ethers such as benzoin methyl ether. 2,4,6-trihalomethyltriazines, 1-hydroxycyclohexyl phenyl ketone, 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di ( m-methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-phenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-phenylimidazole dimer, 2- (P-methoxyphenyl) -4,5-diphenylimidazole dimer, 2, -di (p-methoxyphenyl) -5-phenylimidazole dimer, 2- (2,4-dimethoxyphenyl) -4,5 -2,4,5-triarylimidazole dimer of diphenylimidazole dimer, benzyldimethyl ketal, 2-benzyl-2-dimethyl Amino-1- (4-morpholinophenyl) butan-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 2-hydroxy-2-methyl-1-phenyl -Propan-1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, phenanthrenequinone, 9,10-phenanthrenequinone, Benzoins such as methylbenzoin and ethylbenzoin, 9-phenylacridine, acridine derivatives such as 1,7-bis (9,9'-acridinyl) heptane, bisacylphosphine oxide, and mixtures thereof are preferably used. May be used alone or in combination.

  In addition to these water-soluble photopolymerization initiators, accelerators and the like can also be added. Examples of these include ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, ethanolamine, diethanolamine, triethanolamine and the like.

  These water-soluble photopolymerization initiators are also preferably grafted to the side chain with respect to the hydrophilic main chain.

  A polymer compound having a plurality of side chains in the hydrophilic main chain according to the present invention and capable of cross-linking between side chains by irradiating active energy rays is a main chain originally having a certain degree of polymerization. Since the side chains are cross-linked through a cross-linking bond, the effect of increasing the molecular weight per photon is remarkably greater than that of an ultraviolet curable resin that is polymerized through a general chain reaction. As a result, a very high curing sensitivity was realized.

  In the active energy ray crosslinkable polymer used in the present invention, the number of crosslinking points can be completely controlled by the length of the hydrophilic main chain and the amount of side chains introduced, and the physical properties of the ink film can be controlled according to the purpose. is there.

  Furthermore, almost all of the conventionally known active energy ray-curable inks other than the color material are curable, so that the dots after curing are raised and inferior in image quality typified by gloss, are used in the present invention. The active energy ray crosslinkable polymer requires only a small amount, and since there are many dry components, the image quality after drying can be improved.

(Active energy rays, irradiation method)
Examples of the active energy rays in the present invention include electron beams, ultraviolet rays, α rays, β rays, γ rays, X-rays, etc., but they are dangerous to the human body and easy to handle. Electron beams and ultraviolet rays that are widely used are preferred. In the present invention, ultraviolet rays are particularly preferable.

  When using an electron beam, the amount of the electron beam to be irradiated is preferably in the range of 0.1 to 30 Mrad. If it is less than 0.1 Mrad, a sufficient irradiation effect cannot be obtained, and if it exceeds 30 Mrad, the support or the like may be deteriorated.

  When ultraviolet rays are used, the light source is, for example, a low pressure, medium pressure, high pressure mercury lamp, metal halide lamp, xenon lamp having a light emission wavelength in the ultraviolet region, cold cathode tube, hot cathode tube having an operating pressure of several hundred Pa to 1 MPa. A conventionally well-known thing, such as LED, is used.

(Light irradiation conditions after ink landing)
As the irradiation condition of the active energy ray, it is preferable that the active energy ray is irradiated for 0.001 to 1.0 seconds after the ink has landed on the recording medium, and more preferably 0.001 to 0.00. 5 seconds. In order to form a high-definition image, it is particularly important that the irradiation timing is as early as possible.

(Irradiation method of active energy rays)
As a method for irradiating active energy rays, a basic method is disclosed in Japanese Patent Application Laid-Open No. 60-132767. According to this, the light source is provided on both sides of the head unit, and the head and the light source are scanned by the shuttle method. Irradiation is performed after a certain period of time after ink landing. Further, the curing is completed by another light source that is not driven. In US Pat. No. 6,145,979, as an irradiation method, a method using an optical fiber or a method of irradiating a recording unit with ultraviolet rays by applying a collimated light source to a mirror surface provided on the side surface of the head unit is disclosed. . Any of these irradiation methods can be used in the inkjet recording method of the present invention.

  Also preferred is a method in which the irradiation of active energy rays is divided into two stages, and the active energy rays are first irradiated by the above-described method within 0.001 to 2.0 seconds after ink landing, and further the active energy rays are irradiated. It is one of. By dividing the irradiation of the active energy ray into two stages, it is possible to further suppress the shrinkage of the recording material that occurs during ink curing.

(Resin fine particles)
The ink of the present invention contains resin fine particles together with a polymer compound having a plurality of side chains in the hydrophilic main chain described above and capable of cross-linking between the side chains by irradiation with active energy rays. It is characterized by that.

  By using the active energy ray-crosslinkable polymer according to the present invention and the resin fine particles in combination, the ink is gelled and becomes insoluble by irradiation with ultraviolet rays after printing, and bleeding and feathering are suppressed. In the process where the component penetrates or the volatile component in the ink volatilizes, the resin fine particles form a film on the formed image, whereby the coloring material is fixed, and the scratch resistance and water resistance can be improved.

  Ink using conventional UV curable resin and resin fine particles together, it was difficult to obtain sufficient curing sensitivity due to the light shielding effect of resin fine particles, but it was much harder than conventional UV curable resin. By applying the active energy ray crosslinkable polymer according to the present invention having sensitivity, excellent bleed resistance and feathering resistance can be obtained, and good fixability and water resistance can be realized. .

  The resin fine particles according to the present invention are preferably polymer compounds having a glass transition point (Tg) of −30 ° C. or higher and 150 ° C. or lower, and more preferably −10 ° C. or higher and 120 ° C. or lower. If the glass transition point (Tg) is −30 ° C. or higher, nozzles are not clogged and good light emission can be obtained, and if it is 150 ° C. or lower, good water resistance can be obtained. The glass transition point (Tg) can be measured by a known method utilizing the fact that the coefficient of thermal expansion and specific heat change discontinuously in the process of changing the temperature.

  The resin fine particles according to the present invention are not particularly limited, but are preferably polyurethane, polystyrene-acryl, polystyrene-butadiene, polystyrene-maleic acid, polyester, polyether, polycarbonate, polyamide, polyacrylonitrile, polystyrene, polybutadiene, poly Resin fine particles composed of acrylic acid, polymethacrylic acid, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, acrylic modified silicone resin, acrylic modified fluororesin, etc., or resin fine particles composed of copolymers and salts thereof. Preferably, a copolymer selected from at least one of polyurethane, polystyrene-acryl, polystyrene-butadiene, and polystyrene-maleic acid is used.

  The resin fine particles according to the present invention are particularly preferably polyurethane resin fine particles, and have a good compatibility with the active energy ray-crosslinkable polymer according to the present invention present after volatilization of the volatile components in the ink. Therefore, the gloss of the formed image is very good. Examples of the polyurethane resin fine particles include polyester, polyether, polycarbonate, and aromatic isocyanate, but polyester, polyether, and polycarbonate are more preferable. Specifically, Superflex series (Daiichi Kogyo Seiyaku Co., Ltd.), Permarin UA series (Sanyo Kasei Co., Ltd.), etc. can be used, and one or two or more selected from these can be used in combination. Can do.

  The resin fine particles according to the present invention may be either a forced emulsification type forcibly emulsified with an emulsifier, or a self-emulsification type in which a hydrophilic group or a hydrophilic segment is imparted and dispersed in a resin. A surfactant is often used as an emulsifier, but a polymer having a hydrophilic group such as a sulfonic acid group or a carboxylic acid group (for example, a polymer having a hydrophilic group grafted thereto, a monomer having a hydrophilic part, It is also preferable to use a polymer obtained from a monomer having a hydrophobic portion.

  In recent years, as latex polymer particles, there are also latexes in which core-shell type polymer particles having different compositions at the center and outer edge of the particles are dispersed in addition to the latex in which the polymer particles are uniform throughout. However, this type of latex can also be preferably used.

  The resin fine particles according to the present invention are preferably anionic from the viewpoint of storage stability.

  In the inkjet ink of the present invention, the average particle size of the resin fine particles is preferably 10 nm or more and 200 nm or less, more preferably 10 nm or more and 150 nm or less. If the average particle diameter of the resin fine particles is 10 nm or more, the storage stability is excellent, and if it is 200 nm or less, good gloss can be obtained. The average particle size of the resin fine particles can be determined by a commercially available particle size measuring instrument using a light scattering method, an electrophoresis method, a laser Doppler method, or the like.

  In the inkjet ink of the present invention, the content of the resin fine particles according to the present invention is preferably 5% by mass or more and 200% by mass or less, more preferably 10% by mass or more and 200% by mass with respect to the color material. % Or less. If the content of the resin fine particles according to the present invention is 5% by mass or more with respect to the color material, sufficient scratch resistance and water resistance can be obtained, and if it is 200% by mass or less, the nozzle is clogged. Therefore, the continuous emission is improved.

[Color material]
As the colorant used in the ink jet ink according to the present invention, various dyes or pigments known in ink jet can be used. From the combination with the ionicity of the side chain of the active energy ray-crosslinked resin, anionic It is preferable that

(dye)
There is no restriction | limiting in particular as dye which can be used by this invention, Water-soluble dyes, such as an acid dye, a direct dye, and a reactive dye, a disperse dye, etc. are mentioned, It is an anionic dye.

<Water-soluble dye>
Examples of the anionic water-soluble dye that can be used in the present invention include azo dyes, methine dyes, azomethine dyes, xanthene dyes, quinone dyes, phthalocyanine dyes, triphenylmethane dyes, diphenylmethane dyes, and the like. The specific compound is shown below. However, it is not limited to these exemplified compounds.

<C. I. Acid Yellow>
1, 3, 11, 17, 18, 19, 23, 25, 36, 38, 40, 42, 44, 49, 59, 61, 65, 67, 72, 73, 79, 99, 104, 110, 114, 116, 118, 121, 127, 129, 135, 137, 141, 143, 151, 155, 158, 159, 169, 176, 184, 193, 200, 204, 207, 215, 219, 220, 230, 232, 235, 241, 242, 246,
<C. I. Acid Orange>
3, 7, 8, 10, 19, 24, 51, 56, 67, 74, 80, 86, 87, 88, 89, 94, 95, 107, 108, 116, 122, 127, 140, 142, 144, 149, 152, 156, 162, 166, 168,
<C. I. Acid Red>
88, 97, 106, 111, 114, 118, 119, 127, 131, 138, 143, 145, 151, 183, 195, 198, 211, 215, 217, 225, 226, 249, 251, 254, 256, 257, 260, 261, 265, 266, 274, 276, 277, 289, 296, 299, 315, 318, 336, 337, 357, 359, 361, 362, 364, 366, 399, 407, 415,
<C. I. Acid Violet>
17, 19, 21, 42, 43, 47, 48, 49, 54, 66, 78, 90, 97, 102, 109, 126,
<C. I. Acid Blue>
1, 7, 9, 15, 23, 25, 40, 62, 72, 74, 80, 83, 90, 92, 103, 104, 112, 113, 114, 120, 127, 128, 129, 138, 140, 142, 156, 158, 171, 182, 185, 193, 199, 201, 203, 204, 205, 207, 209, 220, 221, 224, 225, 229, 230, 239, 249, 258, 260, 264, 278, 279, 280, 284, 290, 296, 298, 300, 317, 324, 333, 335, 338, 342, 350,
<C. I. Acid Green>
9, 12, 16, 19, 20, 25, 27, 28, 40, 43, 56, 73, 81, 84, 104, 108, 109,
<C. I. Acid Brown>
2, 4, 13, 14, 19, 28, 44, 123, 224, 226, 227, 248, 282, 283, 289, 294, 297, 298, 301, 355, 357, 413,
<C. I. Acid Black>
1, 2, 3, 24, 26, 31, 50, 52, 58, 60, 63, 107, 109, 112, 119, 132, 140, 155, 172, 187, 188, 194, 207, 222,
<C. I. Direct yellow>
8, 9, 10, 11, 12, 22, 27, 28, 39, 44, 50, 58, 79, 86, 87, 98, 105, 106, 130, 132, 137, 142, 147, 153,
<C. I. Direct orange>
6, 26, 27, 34, 39, 40, 46, 102, 105, 107, 118,
<C. I. Direct Red>
2, 4, 9, 23, 24, 31, 54, 62, 69, 79, 80, 81, 83, 84, 89, 95, 212, 224, 225, 226, 227, 239, 242, 243, 254,
<C. I. Direct Violet>
9, 35, 51, 66, 94, 95,
<C. I. Direct Blue>
1, 15, 71, 76, 77, 78, 80, 86, 87, 90, 98, 106, 108, 160, 168, 189, 192, 193, 199, 200, 201, 202, 203, 218, 225, 229, 237, 244, 248, 251, 270, 273, 274, 290, 291,
<C. I. Direct Green>
26, 28, 59, 80, 85,
<C. I. Direct Brown>
44, 106, 115, 195, 209, 210, 222, 223,
<C. I. Direct Black>
17, 19, 22, 32, 51, 62, 108, 112, 113, 117, 118, 132, 146, 154, 159, 169,
<C. I. Reactive Yellow>
2, 3, 7, 15, 17, 18, 22, 23, 24, 25, 27, 37, 39, 42, 57, 69, 76, 81, 84, 85, 86, 87, 92, 95, 102, 105, 111, 125, 135, 136, 137, 142, 143, 145, 151, 160, 161, 165, 167, 168, 175, 176,
<C. I. Reactive Orange>
1, 4, 5, 7, 11, 12, 13, 15, 16, 20, 30, 35, 56, 64, 67, 69, 70, 72, 74, 82, 84, 86, 87, 91, 92, 93, 95, 107,
<C. I. Reactive Red>
2, 3, 5, 8, 11, 21, 22, 23, 24, 28, 29, 31, 33, 35, 43, 45, 49, 55, 56, 58, 65, 66, 78, 83, 84, 106, 111, 112, 113, 114, 116, 120, 123, 124, 128, 130, 136, 141, 147, 158, 159, 171, 174, 180, 183, 184, 187, 190, 193, 194, 195, 198, 218, 220, 222, 223, 228, 235,
<C. I. Reactive Violet>
1, 2, 4, 5, 6, 22, 23, 33, 36, 38,
<C. I. Reactive Blue>
2, 3, 4, 5, 7, 13, 14, 15, 19, 21, 25, 27, 28, 29, 38, 39, 41, 49, 50, 52, 63, 69, 71, 72, 77, 79, 89, 104, 109, 112, 113, 114, 116, 119, 120, 122, 137, 140, 143, 147, 160, 161, 162, 163, 168, 171, 176, 182, 184, 191, 194, 195, 198, 203, 204, 207, 209, 211, 214, 220, 221, 222, 231, 235, 236,
<C. I. Reactive Green>
8, 12, 15, 19, 21,
<C. I. Reactive Brown>
2, 7, 9, 10, 11, 17, 18, 19, 21, 23, 31, 37, 43, 46,
<C. I. Reactive Black>
5, 8, 13, 14, 31, 34, 39,
<C. I. Food Black>
1, 2,
Etc.

(Pigment)
In the inkjet ink of the present invention, a pigment can be used as a coloring material.

  Examples of the pigment that can be used in the present invention include conventionally known organic or inorganic pigments. For example, azo pigments such as azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments, phthalocyanine pigments, perylene and perylene pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, thioindigo pigments, isoindolinone pigments, quinophthalone pigments, etc. Examples include polycyclic pigments, dye lakes such as basic dye type lakes and acid dye type lakes, organic pigments such as nitro pigments, nitroso pigments, aniline black, daylight fluorescent pigments, and inorganic pigments such as carbon black. However, the present invention is not limited to these.

  Specific organic pigments are exemplified below.

  Examples of pigments for magenta or red include C.I. I. Pigment red 2, C.I. I. Pigment red 3, C.I. I. Pigment red 5, C.I. I. Pigment red 6, C.I. I. Pigment red 7, C.I. I. Pigment red 15, C.I. I. Pigment red 16, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 53: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 123, C.I. I. Pigment red 139, C.I. I. Pigment red 144, C.I. I. Pigment red 149, C.I. I. Pigment red 166, C.I. I. Pigment red 177, C.I. I. Pigment red 178, C.I. I. And CI Pigment Red 222.

  Examples of the orange or yellow pigment include C.I. I. Pigment orange 31, C.I. I. Pigment orange 43, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 15, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. Pigment yellow 128, C.I. I. And CI Pigment Yellow 138.

  Examples of pigments for green or cyan include C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 2, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 16, C.I. I. Pigment blue 60, C.I. I. And CI Pigment Green 7.

  The color material content in the ink of the present invention is 1 to 20% by mass.

  The pigment to be applied in the ink of the present invention is usually dispersed by a known dispersing means using a dispersant, and as an applicable dispersant, an anionic surfactant, a nonionic surfactant, or a water-soluble surfactant is used. A polymeric dispersant can be mentioned.

  As the water-soluble polymer dispersant that can be preferably used in the ink of the present invention, the following water-soluble resin is preferably used from the viewpoint of ejection stability.

  As the water-soluble resin, styrene-acrylic acid-acrylic acid alkyl ester copolymer, styrene-acrylic acid copolymer, styrene-maleic acid copolymer, styrene-maleic acid-acrylic acid alkyl ester copolymer are preferably used. Polymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylic acid alkyl ester copolymer, styrene-maleic acid half ester copolymer, vinyl naphthalene-acrylic acid copolymer, vinyl naphthalene-maleic acid copolymer It is a water-soluble resin such as.

  The content of the water-soluble resin with respect to the total amount of the ink is preferably 0.1 to 10% by mass, and more preferably 0.3 to 5% by mass. Two or more of these water-soluble resins can be used in combination.

  Examples of the dispersing means that can be used in the present invention include a ball mill, a sand mill, an attritor, a roll mill, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a pearl mill, a wet jet mill, a paint shaker, and a high-pressure homogenizer. Various dispersers can be used. It is also preferable to use a centrifugal separator or a filter for the purpose of removing the coarse particles of the pigment dispersion.

  In the inkjet ink of the present invention, a self-dispersing pigment can also be used as a colorant. The self-dispersing pigment refers to a pigment that can be dispersed without a dispersant, and particularly preferably pigment particles having a polar group on the surface.

  The pigment particle having a polar group on the surface refers to a pigment directly modified with a polar group on the surface of the pigment particle, or an organic substance having an organic pigment mother nucleus and having a polar group bonded directly or through a joint. .

  Examples of the polar group include a sulfonic acid group, a carboxylic acid group, a phosphoric acid group, a boric acid group, and a hydroxyl group, preferably a sulfonic acid group and a carboxylic acid group, and more preferably a carboxylic acid group.

  The average particle size of the pigment dispersion used in the ink of the present invention is preferably 500 nm or less, more preferably 200 nm or less, and particularly preferably 100 nm or less.

(Water-soluble solvent)
The ink of the present invention can contain a solvent, and an aqueous liquid medium is preferably used, and a mixed solvent such as water and a water-soluble organic solvent is more preferably used. Examples of water-soluble organic solvents that are preferably used include alcohols (eg, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, secondary butanol, tertiary butanol), polyhydric alcohols (eg, ethylene glycol, diethylene glycol, Triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, hexanediol, pentanediol, glycerin, hexanetriol, thiodiglycol), polyhydric alcohol ethers (eg, ethylene glycol monomethyl ether, ethylene Glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol Nomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, ethylene glycol Monophenyl ether, propylene glycol monophenyl ether), amines (for example, ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenediamine, triethylenetetra) , Tetraethylenepentamine, polyethyleneimine, pentamethyldiethylenetriamine, tetramethylpropylenediamine), amides (eg, formamide, N, N-dimethylformamide, N, N-dimethylacetamide, etc.), heterocycles (eg, 2 -Pyrrolidone, N-methyl-2-pyrrolidone, cyclohexyl pyrrolidone, 2-oxazolidone, 1,3-dimethyl-2-imidazolidinone), sulfoxides (for example, dimethyl sulfoxide) and the like.

(Surfactant)
The ink of the present invention can contain a surfactant. Examples of the surfactant include alkyl sulfates, alkyl ester sulfates, dialkyl sulfosuccinates, alkyl naphthalene sulfonates, alkyl phosphates, polyphosphates, and the like. Nonionic surfactants such as oxyalkylene alkyl ether phosphates and fatty acid salts, polyoxyethylene alkyl ethers, polyoxyalkylene alkyl phenyl ethers, acetylene glycols, polyoxyethylene-polyoxypropylene block copolymers Surfactants such as ionic surfactants, glycerin esters, sorbitan esters, polyoxyethylene fatty acid amides, amine oxides, and cationic surfactants such as alkylamine salts and quaternary ammonium salts. These surfactants can also be used as pigment dispersants, and anionic surfactants can be particularly preferably used.

(Various additives)
In the ink of the present invention, in addition to the above description, if necessary, the output stability, print head and ink cartridge compatibility, storage stability, image storage stability, and other various performance improvement objectives are known. Various additives such as a viscosity modifier, a specific resistance modifier, a film forming agent, an ultraviolet absorber, an antioxidant, a fading inhibitor, an antifungal agent, a rust inhibitor, etc. can be appropriately selected and used. Oil droplet fine particles such as liquid paraffin, dioctyl phthalate, tricresyl phosphate, silicone oil, ultraviolet absorbers described in JP-A-57-74193, JP-A-57-87988, and JP-A-62-261476; -74192, 57-87989, 60-72785, 61-146591, JP-A-1-95091 and 3-13376, etc. Anti-fading agents, fluorescent whitening agents described in JP-A-59-42993, JP-A-59-52689, JP-A-62-280069, JP-A-61-242871, and JP-A-4-219266. be able to.

(Inkjet recording method)
In the inkjet recording method of the present invention, the inkjet ink of the present invention is ejected onto a recording medium using an inkjet head to form an image.

  The ink jet head used in the ink jet recording method of the present invention may be an on-demand system or a continuous system. As the discharge method, an electro-mechanical conversion method (for example, single cavity type, double cavity type, bender type, piston type, shear mode type, shared wall type, etc.), electro-thermal conversion method (for example, thermal ink jet) Specific examples include a mold, a bubble jet (registered trademark) type, an electrostatic attraction method (for example, an electric field control type, a slit jet type, etc.), and a discharge method (for example, a spark jet type). However, any discharge method may be used. Further, as a printing method, a serial head method, a line head method, etc. can be used without limitation, but among them, it is particularly preferable for an ink jet recording method using an ink jet head having a line head method with severe requirements for clogging. Can also be used.

(recoding media)
Examples of the recording medium that can be applied in the ink jet ink recording method of the present invention include absorptive supports such as plain paper and high-quality paper, or low-absorbency recording media such as art paper or coated paper, or non-absorbing films. Absorbent media and inkjet recording media can be widely used.

The paper, coated paper, there is a non-coated paper, as the coated paper, the coating amount per 1m ² is one side 20g before and after of art paper, 1m ² per coated amount on one side 10g before and after the coated paper Examples include a light-weight coated paper having a coating amount per 1 m ^{2 of} about 5 g on one side, a finely coated paper, a mat-like finished mat-coated paper, a dull-like finished dull-coated paper, and a newsprint. Non-coated paper includes printing paper A using 100% chemical pulp, printing paper B using 70% or more chemical pulp, printing paper C using 40% or more and less than 70% chemical pulp, and printing using less than 40% chemical pulp. Examples thereof include paper D, gravure paper containing mechanical pulp and subjected to calendar treatment. More details are described in detail in “Latest Paper Processing Handbook” edited by the Paper Processing Handbook Editorial Committee, published by Tech Times, “Printing Engineering Handbook” edited by the Japan Printing Society.

  The plain paper is 80 to 200 μm uncoated paper belonging to a part of uncoated paper, special printing paper and information paper. The plain paper used in the present invention includes, for example, high-grade printing paper, intermediate-grade printing paper, low-grade printing paper, thin-like printing paper, fine-coating printing paper, special printing paper such as fine-quality printing paper, foam paper, PPC paper, and others There are information sheets and the like. Specifically, there are the following sheets and various modified / processed sheets using these sheets, but the present invention is not particularly limited thereto.

  High quality paper and colored high quality paper, recycled paper, copy paper / colored paper, OCR paper, carbonless paper / colored paper, synthetic paper such as YUPO 60, 80, 110 microns, YUPO COAT 70, 90 microns, etc. Coated paper 90kg, Foam mat paper 70, 90, 110kg, Foamed PET 38 microns, Mitsuori-kun (above, Kobayashi recording paper), OK fine paper, New OK fine paper, Sunflower, Phoenix, OK Royal White, Export fine paper ( NPP, NCP, NWP, Royal White) OK Book Paper, OK Cream Book Paper, Cream Premium Paper, OK Map Paper, OK Ishikari, Cucumber, OK Foam, OKH, NIP-N (above, Shin Oji Paper), Gold Wang, Toko, export quality paper, special demand quality paper, book paper, book paper L, light cream book paper, elementary textbook Paper, continuous slip paper, high quality NIP paper, silver ring, gold yang, gold yang (W), bridge, capital, silver ring book, harp, harp cream, SK color, securities paper, opera cream, opera, KYP medical record, silvia HN, Excellent Foam, NPI Foam DX (Nippon Paper), Pearl, Kinryo, Uscream fine paper, Special Book Paper, Super Book Paper, Book Paper, Diamond Foam, Inkjet Foam (Mitsubishi Paper), Carpet V, carpet SW, white elephant, luxury publication paper, cream carpet, cream white elephant, securities / voucher paper, book paper, map paper, copy paper, HNF (above, Hokuetsu), phone book cover, Book paper, cream shirairai, cream shirairaifu, cream shirairaifu, DSK (above, Daishowa Paper), Sendai MP fine paper, Jiang, Thunderbird quality, hanging paper, colored paper base, dictionary paper, cream book, white book, cream quality paper, map paper, continuous slip paper (above, Chuetsu Pulp), OP gold cherry (Chuetsu), gold sand, reference book paper, Replacement certificate paper (white), form printing paper, KRF, white foam, color foam, (K) NIP, fine PPC, Kishu inkjet paper (above, made by Kishu Paper), Taiou, Bright Foam, Kant, Kant White, Dante , CM paper, Dante comic, Heine, paperback book paper, Heine S, New AD paper, Utrilo Excel, Excel Super A, Kant Excel, Excel Super B, Dante Excel, Heine Excel, Excel Super C, Excel Super D, AD Excel, Excel Super E, New Bright Foam, New Bright NI P (above, made by Daio Paper), Sun Ring, Moon Ring, Cloud Pass, Galaxy, Baiyun, Wyeth, Moon Ring Ace, Baiyun Ace, Cloud Pass Ace (above, Nippon Paper Industries), Taiou, Bright Foam, Bright Nip (Nagoya Pulp), Peony A, Golden Pigeon, Special Peony, White Peony A, White Peony C, Silver Pigeon, Super White Peony A, Light Cream White Peony, Special Medium Quality Paper, White Pigeon, Super Medium Quality Paper, Blue Pigeon, Red Pigeon, Gold Pigeon M Snow Vision, Snow Vision, Gold Pigeon Snow Vision, White Pigeon M, Super DX, Hamanasu O, Red Pigeon M, HK Super Printing Paper (Made by Honshu Paper), Stalinden (A・ AW), Star Elm, Star Maple, Star Laurel, Star Poplar, MOP, Star Cherry I, Cherry I Super, Cherry II Super, Star Cherry III, Star Cherry IV, Cherry III Super, Cheri -IV Super (above, made by Maruzumi Paper), SHF (above, made by Toyo Pulp), TRP (above, made by Tokai Pulp), etc.

  Typical printing papers include Mitsubishi Paper's Tokuhishi Art and Oji Paper's OK Top Coat N.

  As the various films, all commonly used films can be used. For example, there are a polyester film, a polyolefin film, a polyvinyl chloride film, a polyvinylidene chloride film, and the like. Resin-coated paper that is photographic printing paper or YUPO paper that is synthetic paper can also be used.

  As the various ink jet recording media, an ink receiving layer is formed on the surface using an absorbent support or a non-absorbent support as a base material. Examples of the ink receiving layer include a coating layer, a swelling layer, and a fine void layer.

  The swelling layer absorbs ink when the ink receiving layer made of a water-soluble polymer swells. The fine void layer is composed of inorganic or organic fine particles having a secondary particle size of about 20 to 200 nm and a binder, and fine voids of about 100 nm absorb ink.

  In recent years, an inkjet recording medium in which the above-mentioned fine void layer is provided on a base material using RC paper in which both sides of a paper base material are coated with an olefin resin is preferably used in terms of photographic images.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "part by mass" or "mass%" is represented.

《Synthesis of active energy ray crosslinkable polymer compound》
(Synthesis of active energy ray crosslinkable polymer compound 1)
After 100 g of polyacrylic acid (weight average molecular weight 800,000) was dissolved in 750 g of methanol by heating, 16 g of 4-hydroxybutyl acrylate glycidyl ether and 11 g of pyridine as a catalyst were added and stirred for 24 hours while maintaining at 60 ° C. Furthermore, after raising the temperature of the system to 95 ° C. and distilling off methanol while adding water dropwise, it was treated with an ion exchange resin (Mitsubishi Chemical: PK-216H) to remove pyridine and remove the non-volatile concentration. A 15% aqueous solution was obtained. In this aqueous solution, n = 1 Irgacure 2959 (manufactured by Ciba Specialty Chemicals Co., Ltd.) of the general formula (7) as a photopolymerization initiator was mixed at a ratio of 0.1 g with respect to 100 g of 15% aqueous solution. Dilution with exchange water gave an aqueous solution of 10% active energy ray crosslinkable polymer compound 1.

(Synthesis of active energy ray crosslinkable polymer compound 2)
56 g of glycidyl methacrylate, 48 g of p-hydroxybenzaldehyde, 2 g of pyridine, and 1 g of N-nitroso-phenylhydroxyamine ammonium salt were put in a reaction vessel and stirred in a hot water bath at 80 ° C. for 8 hours.

  Subsequently, 45 g of polyvinyl acetate saponified product having a polymerization degree of 2200 and a saponification rate of 88% was dispersed in 225 g of ion-exchanged water, and then 4.5 g of phosphoric acid was added to this solution and p- (3-methacryloxy obtained in the above reaction. 2-Hydroxypropyloxy) benzaldehyde was added so that the modification rate was 3.0 mol% with respect to polyvinyl alcohol, and the mixture was stirred at 90 ° C. for 6 hours. After cooling the obtained solution to room temperature, 30 g of basic ion exchange resin was added and stirred for 1 hour. Thereafter, the ion exchange resin was filtered, and Irgacure 2959 (supra) as a photopolymerization initiator was mixed at a rate of 0.1 g with respect to 100 g of a 15% aqueous solution, and then diluted with ion exchange water. % Aqueous solution of active energy ray crosslinkable polymer compound 2 was obtained.

(Synthesis of active energy ray crosslinkable polymer compounds 3 to 7)
In the synthesis of the active energy ray-crosslinkable polymer compound 2, the polymerization degree of the polyvinyl acetate saponified product shown in Table 1 was adjusted to be the saponification degree, and p- (3-methacryloxy-2-hydroxypropyloxy was further adjusted. ) Active energy ray crosslinkable polymer compounds 3 to 7 were synthesized in the same manner except that the amount of benzaldehyde added was changed to adjust the introduction modification rate, and 10% active energy ray crosslinkable polymer compounds 3 to 7 were synthesized. An aqueous solution of was obtained.

(Active energy ray crosslinkable polymer compound 8)
A compound represented by general formula (4) in which R is a p-phenylene group (RSP manufactured by Toyo Gosei Co., Ltd., main chain PVA polymerization degree 500, saponification degree 88%, modification rate 3.0 mol%), active energy ray crosslinking An aqueous solution of 10% active energy ray crosslinkable polymer compound 8 was obtained.

<Preparation of ink set>
Ink sets 1 to 19 were prepared as follows.

(Preparation of pigment dispersion)
(Preparation of magenta pigment dispersion)
The following additives were mixed and dispersed using a sand grinder filled with 50% by volume of 0.6 mm zirconia beads to prepare a magenta pigment dispersion having a magenta pigment content of 15%. The average particle diameter of the magenta pigment particles contained in this magenta pigment dispersion was 80 nm. The particle size was measured using a Zetasizer 1000HS manufactured by Malvern.

C. I Pigment Red 122 15 parts Jonkrill 61 (Styrene-acrylic resin dispersant, manufactured by Johnson, solid content 30%) 10 parts Glycerin 15 parts Ion-exchanged water 60 parts (Preparation of black pigment dispersion)
Carbon black self-dispersion product Cabot-jet 300 manufactured by Cabot was diluted with ion-exchanged water to prepare a black pigment dispersion liquid having a carbon black content of 15%. The average particle size of the carbon black particles contained in the obtained black pigment dispersion was 148 nm. The particle size was measured using a Zetasizer 1000HS manufactured by Malvern.

[Preparation of ink set 1]
<Preparation of magenta pigment ink 1>
Magenta pigment dispersion (solid content 15%) 20 parts Aqueous solution of active energy ray crosslinkable polymer compound 1 (solid content 10%) 28 parts Resin fine particles: Superflex 110 (urethane resin fine particles, Tg = 48 ° C., particle size = 0.09 μm, solid content 30%, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 4.5 parts Triethylene glycol monoethyl ether 15 parts 1,2-hexanediol 5 parts Orphine E1010 (manufactured by Nissin Chemical) 1 part Agent: Proxel GXL (manufactured by Avicia) 0.3 part Ion exchange water was added to finish to 100 parts.

  In addition, the addition amount of resin fine particle showed the quantity corresponded to solid content.

<Preparation of Black Pigment Ink 1>
A black pigment ink 1 was obtained in the same manner as in the preparation of the magenta pigment ink 1 except that a black pigment dispersion was used instead of the magenta pigment dispersion.

  The magenta pigment ink 1 and the black pigment ink 1 thus prepared were used as an ink set 1.

(Preparation of ink sets 2 to 16)
In the preparation of the ink set 1, the type of active energy ray crosslinkable polymer compound, the type of resin fine particles, and the addition amount (% by mass) to the pigment were changed in the same manner as described in Table 1, Magenta pigment ink 2 + black pigment ink 2 = ink set 2> to <magenta pigment ink 16 + black pigment ink 16 = ink set 16> were prepared.

(Preparation of ink set 17)
<Preparation of magenta pigment ink 17>
Magenta pigment dispersion (solid content 15%) 20 parts Aqueous UV curable urethane acrylate resin emulsion (solid content 40%, manufactured by Taisei Kako Co., Ltd., trade name: WBR-839) 7 parts 2-pyrrolidinone 15 parts Ethylene glycol 10 parts Orphin E1010 (manufactured by Nissin Chemical Co., Ltd.) 1 part Antifungal agent: Proxel GXL (manufactured by Abyssia) 0.3 part Ion exchange water was added to finish to 100 parts.

<Preparation of black pigment ink 17>
A black pigment ink 17 was obtained in the same manner as in the preparation of the magenta pigment ink 17 except that a black pigment dispersion was used instead of the magenta pigment dispersion.

  The prepared magenta pigment ink 17 and black pigment ink 17 were used as an ink set 17.

(Preparation of ink set 18)
In the preparation of the ink set 6, a magenta pigment ink 18 and a black pigment ink 18 were prepared in the same manner except that water was used instead of the active energy ray crosslinkable polymer 6. .

(Preparation of ink set 19)
<Preparation of magenta pigment ink 19>
Magenta pigment dispersion (solid content 15%) 20 parts Aqueous UV curable urethane acrylate resin emulsion (solid content 40%, manufactured by Taisei Kako Co., Ltd., trade name: WBR-839) 7 parts Resin fine particle: Superflex 110 (urethane type) Resin fine particles, Tg = 48 ° C., particle size = 0.09 μm, solid content 30%, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 4.5 parts 2-pyrrolidinone 15 parts ethylene glycol 10 parts Olphine E1010 (manufactured by Nisshin Chemical Co., Ltd.) 1 Part Antifungal agent: Proxel GXL (manufactured by Avicia) 0.3 part Ion exchange water was added to finish to 100 parts.

<Preparation of black pigment ink 19>
A black pigment ink 19 was obtained in the same manner as in the preparation of the magenta pigment ink 19 except that a black pigment dispersion was used instead of the magenta pigment dispersion.

  The prepared magenta pigment ink 19 and black pigment ink 19 were used as an ink set 19.

  Details of ink sets 1 to 19 prepared as described above are shown in Table 1.

  In addition, the detail of each resin fine particle of Table 1 is as follows.

Superflex 110: Urethane resin fine particles, Tg = 48 ° C., average particle size = 0.09 μm, manufactured by Daiichi Kogyo Seiyaku Co., Ltd. Superflex 130: Urethane resin fine particles, Tg = 101 ° C., average particle size = 0.02 μm, Daiichi Kogyo Seiyaku Co., Ltd. Superflex 300: Urethane resin fine particles, Tg = −42 ° C., average particle size = 0.07 μm, Daiichi Kogyo Seiyaku Co., Ltd. Superflex 420: Urethane resin fine particles, Tg = −10 ° C. Average particle size = 0.01 μm, manufactured by Daiichi Kogyo Seiyaku Co., Ltd. Superflex E-2500: Urethane resin fine particles, Tg = 42 ° C., average particle size = 0.96 μm, manufactured by Daiichi Kogyo Seiyaku Co., Ltd. Acrylic resin fine particles, Tg = 16 ° C., average particle size = 0.06 μm, manufactured by Jonkrill SX1105: Styrene-butadiene tree Particles, Tg = 0 ℃, average particle size = 0.10 .mu.m, manufactured by Nippon Zeon Co., Ltd. "formation of an ink jet image and Evaluation"
(Evaluation of ink storage stability)
Each ink set was stored for 3 to 10 days in an environment of 60 ° C., the state of each ink was visually observed, and the ink storage stability was evaluated according to the following criteria.

◎: Precipitation is not observed in either magenta ink or black ink even after 10 days of storage ○: Precipitation is observed in either magenta ink or black ink after 10 days of storage △: Storage After 5 days, either magenta ink or black ink shows the occurrence of precipitate. X: After 5 days of storage, both magenta ink and black ink show the occurrence of precipitation. Xx: After 3 days of storage. , Magenta ink and black ink both generate precipitates (evaluation of ejection stability: resistance to nozzle clogging)
<Evaluation of continuous discharge stability>
In an environment of 20 ° C. and 30% RH, each ink set is mounted on an ink jet printer equipped with a piezo-type head having a nozzle hole diameter of 20 μm, a driving frequency of 10 kHz, and the number of nozzles of 128. The state after the discharge was continuously continued for 1 hour without cleaning was visually observed, and the continuous discharge stability was evaluated according to the following criteria.

◎: Normal emission from all nozzles ○: Clogging is observed in 1 to 3 nozzles, but recovered by suction cleaning from the nozzle surface △: Clogging occurs in 4 or more nozzles and cannot be recovered by suction cleaning Clogging occurs in one nozzle, but is in a practically acceptable range. X: Clogging occurs in 7 or more nozzles, and clogging that cannot be recovered by suction cleaning occurs in 2 nozzles. Xx: Clogging in 10 or more nozzles. 3 nozzles or more that could not be recovered by suction cleaning occurred. <Evaluation of intermittent discharge stability>
In an environment of 20 ° C. and 30% RH, each ink set is mounted on an ink jet printer equipped with a piezo-type head having a nozzle hole diameter of 20 μm, a driving frequency of 10 kHz, and the number of nozzles of 128. 1) Continuous discharge for 10 seconds, 2) After stopping discharge for a predetermined time, 3) Continuous discharge for 10 seconds was performed again. At this time, 2) the length of the pause time is changed stepwise from 1 second to 40 seconds, and there is no disturbance in the discharge direction at the beginning of the re-discharge of 3), and stable re-discharge can be performed. The rest time was obtained, and intermittent discharge stability was evaluated according to the following criteria.

◎: Stable ejection was performed when the pause time was 30 seconds or more and 40 seconds or less. ○: Stable ejection was performed when the pause time was 20 seconds or more and 29 seconds or less. Δ: Stable discharge in the range of 10 seconds or more and 19 seconds or less, and disturbance of discharge occurs in some nozzles in 20 seconds or more ×: Stable in the range of pause times of 5 seconds or more and 9 seconds or less Discharge occurred in 10 seconds or more and discharge disturbance occurred. XX: Stable discharge could only be performed within a pause time of 4 seconds or less (Evaluation of feathering resistance)
A piezo-type head having a nozzle diameter of 25 μm, a drive frequency of 12 kHz, a nozzle count of 128, and a nozzle density of 180 dpi is mounted on an on-demand type ink jet printer having a maximum recording density of 720 × 720 dpi. A black fine line having a width of 100 μm was printed on a first class paper manufactured by Business Technology Corporation.

  In addition, 120 seconds after continually discharging and landing, a 120 W / cm metal halide lamp (MAL 400NL manufactured by Nihon Battery Co., Ltd., power supply power 3 kW · hr) was irradiated.

  The fine line image obtained as described above was visually observed for the presence of bleeding, and the feathering resistance was evaluated according to the following criteria.

◎: Fine lines can be clearly confirmed ○: Slight blurring is confirmed, but the effect on the fine line image is small △: Slight blurring is observed, but it is within a practically acceptable range ×: Smudge is seriously generated , Practical quality is unacceptable. XX: Severe blurring, unclear border of fine lines, unusable for practical use (evaluation of color bleed resistance)
A piezo-type head with a nozzle diameter of 25 μm, a drive frequency of 12 kHz, a nozzle count of 128, and a nozzle density of 180 dpi. Each ink set is mounted on an on-demand type ink jet printer with a maximum recording density of 720 × 720 dpi, and art paper (Oji Paper) An image pattern in which black characters with different print points are arranged on a solid magenta image was output to NK Art Kanfuji N). In addition, dpi as used in the field of this invention represents the number of dots per 2.54 cm.

  Next, each ink was continuously ejected and, after landing, 0.1 seconds later, a 120 W / cm metal halide lamp (MAL 400NL manufactured by Nihon Battery Co., Ltd., power supply power 3 kW · hr) was irradiated.

  About the image obtained by the above, the presence or absence of color mixing was visually observed and color bleed resistance was evaluated according to the following criteria.

◎: No color mixing at all ○: Color mixing is a little, but 5-point characters can be confirmed △: Color mixing is slightly, but 7-point characters can be confirmed, and is in a practically acceptable range ×: Color Mixing was severe and only 9-point characters could be confirmed. XX: Color mixing was quite severe and even 9-point characters could not be confirmed (evaluation of beading resistance)
Using an on-demand type ink jet printer with a maximum recording density of 720 × 720 dpi, using a piezo head having a nozzle diameter of 25 μm, a drive frequency of 12 kHz, a nozzle number of 128, and a nozzle density of 180 dpi, art paper (NK Art Kanto N manufactured by Oji Paper) ) Was printed with a 10 cm × 10 cm magenta solid image, the solid image was visually observed, and beading resistance was evaluated according to the following criteria.

  Ink was continuously ejected, and 0.1 seconds after landing, a 120 W / cm metal halide lamp (MAL 400NL, manufactured by Nippon Battery Co., Ltd., power supply power 3 kW · hr) was irradiated.

◎: Uniform image ○: Mottled noise, which can be seen by looking closely, is present in less than 6 points Δ: Mottled noise, which can be seen by looking closely, is present in 6 points or more and less than 12 points ×: Clear mottled shape There are 12 or more noises and less than 20 noises. XX: Mottled noises are 20 or more noises. Of these, XX and XX are qualities that are problematic as a product.

(Evaluation of scratch resistance)
A piezo-type head with a nozzle diameter of 25 μm, a drive frequency of 12 kHz, a nozzle count of 128, and a nozzle density of 180 dpi is mounted on an on-demand type ink jet printer with a maximum recording density of 720 × 720 dpi, and art paper (Oji Paper) NK Art Kanto N) and high-quality paper (First Class paper, manufactured by Konica Minolta Business Technology Co., Ltd.) were printed on a 10 cm × 10 cm magenta solid.

  In addition, 0.1 seconds after the ink was continuously ejected and landed, a 120 W / cm metal halide lamp (MAL 400NL manufactured by Nippon Battery Co., Ltd., power supply power 3 kW · hr) was irradiated to prepare an evaluation image sample.

  After the image sample formed as described above was rubbed 10 times with an eraser (manufactured by MONON Dragonfly Pencil Co., Ltd.), the printed portion was visually observed for the presence or absence of stains, and scratch resistance was evaluated according to the following criteria.

◎: No change in the printed image ○: Slight stain is observed in the printed image when observed in detail △: Stain is slightly observed in the printed image, but is in a practically acceptable range ×: The printed image Stain is clearly observed and the quality is outside the acceptable range for practical use. XX: Printed image is very dirty and cannot withstand practical use (evaluation of water resistance)
An evaluation image sample was prepared in the same manner as the evaluation of scratch resistance.

  The evaluation image sample was water-immersed in Kimwipe S-200 (manufactured by Crecia) and rubbed five times, and the degree of image density reduction was visually observed, and water resistance was evaluated according to the following criteria.

◎: No color fading is observed at all. ○: Some color fading is observed, but the image is not a concern. △: Color fading is slightly confirmed, and a slight decrease in image quality is observed, but acceptable in practice. Within the possible range ×: Color loss is large, the effect on image quality is large, and the quality is unacceptable for practical use. ××: Color loss is quite large, the image is heavily soiled, and is not practical. Evaluation)
A piezo-type head with a nozzle diameter of 25 μm, a drive frequency of 12 kHz, a nozzle count of 128, and a nozzle density of 180 dpi is mounted on an on-demand type ink jet printer with a maximum recording density of 720 × 720 dpi, and art paper (Oji Paper) A solid image of 10 cm × 10 cm magenta was printed on NK Art Kanto N).

  In addition, 0.1 seconds after the ink was continuously ejected and landed, a 120 W / cm metal halide lamp (MAL 400NL manufactured by Nippon Battery Co., Ltd., power supply power 3 kW · hr) was irradiated to prepare an evaluation image sample.

  The gloss of the evaluation image sample was visually observed and evaluated according to the following criteria.

A: Natural with little difference in glossiness between the recording surface and the substrate. ○: The glossiness between the recording surface and the substrate is slightly different. △: The glossiness between the recording surface and the substrate is visually different. Within the allowable range ×: The glossiness of the recording surface and the base is clearly observable visually, and the glossiness of the recording surface is lower than the base XX: The glossiness of the recording surface and the base is clearly different Table 2 shows the results obtained as described above, and the glossiness of the recording surface is significantly lower than the background.

  As is clear from the results shown in Table 2, the polymer fine particles and the hydrophilic main chain have a plurality of side chains, and contain polymer compounds that can be cross-linked between the side chains by irradiating active energy rays. The ink set composed of the ink of the present invention is superior to the comparative example in terms of ejection stability during ink ejection, excellent feathering resistance when printed on plain paper, water resistance and scratch resistance, and art. It can be seen that the image printed on paper is excellent in color bleed resistance, beading resistance, scratch resistance and water resistance, and has improved gloss.

Claims (13)

It contains at least a coloring material, a polymer compound, and resin fine particles. The polymer compound has a plurality of side chains in the hydrophilic main chain, and can be cross-linked between side chains by irradiation with active energy rays. An ink-jet ink comprising a molecular compound. 2. The inkjet ink according to claim 1, wherein the resin fine particles have a glass transition point (Tg) of −30 ° C. or higher and 150 ° C. or lower. The inkjet ink according to claim 1 or 2, wherein the resin fine particles have an average particle size of 10 nm or more and 200 nm or less. 4. The ink-jet ink according to claim 1, wherein a content of the resin fine particles is 5% by mass or more and 200% by mass or less with respect to the coloring material. The inkjet ink according to claim 1, wherein the resin fine particles are polyurethane resin fine particles. 6. The polymer compound according to claim 1, wherein the polymer compound is a saponified product having a hydrophilic main chain of polyvinyl acetate, a saponification degree of 77 to 99%, and a polymerization degree of 200 to 4000. The inkjet ink of Claim 1. The inkjet ink according to any one of claims 1 to 6, wherein a modification rate of a side chain with respect to the hydrophilic main chain of the polymer compound is 0.8 mol% or more and 4 mol% or less. . The inkjet ink according to any one of claims 1 to 7, further comprising a water-soluble photopolymerization initiator. An inkjet ink set comprising two or more inkjet inks, wherein at least one of the inkjet inks is the inkjet ink according to any one of claims 1 to 8. . An ink jet recording method comprising: drying the ink jet ink according to claim 1 after discharging the ink jet ink onto the recording medium, irradiating with ultraviolet rays. An ink jet recording method comprising: discharging the ink jet ink set according to claim 9 onto a recording medium; The ink jet recording method according to claim 10 or 11, wherein the recording medium is a low-absorbency recording medium or a non-absorbing recording medium. The inkjet recording method according to claim 10 or 11, wherein the recording medium is plain paper.