JP2007138073A - Inkjet ink set and inkjet recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an inkjet ink set that has slight ink absorption, does not cause beading and color bleeding to a medium having no ink absorption and has improved sense of gloss incompatibility of shadow part and highlight part and light source dependence of image. <P>SOLUTION: The inkjet ink set comprises two or more kinds of inkjet ink containing at least a colorant, water and a polymer compound containing a plurality of side chains on a hydrophilic main chain and crosslinkable and bondable between side chains by irradiation with an active energy ray and contains black ink and at least two kinds of gray ink having different black colorant concentrations. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is an ink jet ink which has no beading or color bleeding on a medium with little ink absorbability or no ink absorbability, and which has an uncomfortable glossiness between shadow and highlight portions and an image light source dependency. The present invention relates to an ink set and an inkjet recording method.

  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 ink suitable for each purpose is used.

  In particular, in recent years, the recording speed has been greatly improved, and printers having performance capable of withstanding light printing applications have been developed.

  However, in order to bring out the performance of the ink jet printer, an ink jet special paper provided with ink absorbability is required.

  When recording on coated paper or art paper that does not absorb much ink, or on plastic film that does not absorb ink at all, there are problems such as so-called bleed that cause different color ink liquids to mix on the recording medium and cause color turbidity. However, it has been a problem in providing a variety of recording media to inkjet.

  In the above problems, a hot-melt ink composition made of a wax that is solid at room temperature is used, liquefied by heating, etc., sprayed with some energy applied, cooled and solidified while adhering to the recording medium, and recorded A hot-melt ink jet recording method for forming dots has been proposed.

  Since this ink is solid at room temperature, it does not get dirty during handling, and there is no substantial amount of ink evaporation at the time of melting, so there is no clogging of the nozzles. Furthermore, an ink composition has been proposed that solidifies immediately after adhering and has less color bleeding and provides good print quality regardless of paper quality (see Patent Documents 1 and 2).

  However, an image recorded by such a method has problems such as deterioration in quality due to the rising of the dots and lack of scratching performance because the ink dots are in the form of soft wax.

  On the other hand, an inkjet recording ink that is cured by exposure to ultraviolet rays has been disclosed (see Patent Document 3). In addition, a so-called non-aqueous ink containing a pigment as an essential component and a triacrylate or higher polyacrylate as a polymerizable material and using a ketone or an alcohol as a main solvent has been proposed (Patent Document 4). reference).

  Further, an ink using an aqueous ultraviolet polymerization monomer has been proposed (see Patent Document 5).

  In these methods, since the ink itself is cured with a curing component, recording is possible even on a non-absorbing medium. However, since the curing component other than the colorant is contained in a large amount and does not volatilize, the recording surface is reduced. The ink dots swelled up, causing unnaturalness in image quality, especially gloss. Furthermore, there is a safety concern for conventionally known curing components, and there is a problem that even if safety is cleared, there is a narrow selection of substances and it is not possible to design materials and physical properties freely.

  We solve the above problems by including in the water-based ink a polymer compound having a plurality of side chains in the hydrophilic main chain and capable of crosslinking between the side chains by irradiation with active energy rays. I found.

However, it has been found that, depending on the image, there is a light source dependency in which a difference in gloss is felt between the shadow portion and the highlight portion, or the appearance of the image portion changes depending on the light source.
US Pat. No. 4,391,369 U.S. Pat. No. 4,484,948 U.S. Pat. No. 4,228,438 Japanese Patent Publication No. 5-64667 JP-A-7-224241

  Accordingly, an object of the present invention is that no beading or color bleeding occurs on a medium with low ink absorption or non-ink absorption, and the glossiness between the shadow portion and the highlight portion is uncomfortable and the light source dependency of the image. To provide an improved ink jet ink set and recording method.

  The above problem could be solved by the following configuration.

  1. An ink-jet ink comprising at least a colorant, water, and a polymer compound having a plurality of side chains in a hydrophilic main chain and capable of crosslinking between side chains by irradiation with active energy rays An ink jet ink set comprising two or more ink jet ink sets, wherein the ink jet ink set contains black ink and at least two types of gray inks having different black color material concentrations.

  2. 2. The inkjet ink set as described in 1 above, wherein the inkjet ink set comprises yellow ink, magenta ink, cyan ink, black ink, light gray ink, and gray ink.

  3. 3. The inkjet ink set as described in 1 or 2 above, wherein the black ink and the color material of at least two types of gray ink are carbon black.

  4). The ink according to any one of 1 to 3, wherein the ink containing the polymer compound contains 0.8 to 5.0% by mass of the polymer compound with respect to the total mass of the ink. Ink set.

  5. The hydrophilic main chain is a saponified product of polyvinyl acetate, and has a saponification degree of 77 to 99% and a polymerization degree of 200 to 4000. Ink set for inkjet.

  6). 6. The inkjet ink set according to any one of 1 to 5, wherein a modification rate of the side chain with respect to the hydrophilic main chain is 0.8 mol% or more and 4 mol% or less.

  7). 7. The ink set for inkjet according to any one of 1 to 6, further comprising a water-soluble photopolymerization initiator.

  8). 8. An ink jet recording method comprising discharging the ink set for ink jet according to any one of 1 to 7 onto a recording medium, irradiating the ink jet ink with active energy rays, and then drying.

  According to the present invention, there is no occurrence of beading or color bleeding with respect to a medium having low ink absorbability or non-ink absorbability, and the glossiness in the shadow portion and the highlight portion is improved, and the light source dependency of the image is improved. Ink set and recording method could be provided.

  The present invention will be described in detail below.

  In the present invention, the hydrophilic main chain has a plurality of side chains, and a water-based ink contains a polymer compound that can be cross-linked between the side chains by irradiating active energy rays. Later, the ink itself thickens on the recording medium, and it is possible to suppress the occurrence of color mixing between different colors (color bleeding) and mottle (beading) due to ink overflow. Therefore, it is possible to print directly on a recording medium having no absorbency.

  Conventionally, there has been a technique of putting a component that cures with active energy in this way into the ink. However, the component to be cured is a monomer, energy efficiency is low, and if a considerable amount is not added to the ink, it is non-absorbing. It was not possible to print directly on the recording medium. For this reason, the swell of the image portion is increased, and an image having a high smoothness cannot be obtained.

  In the present invention, only a small amount of the curing component is required, and the total solid content in the ink can be suppressed to about 10%. Therefore, the rise of the image portion after the volatile component is volatilized is very thin. Therefore, it is possible to print an image with high image quality and high smoothness as it is on a recording medium having low or no absorbency such as printing paper.

  However, it has been found that, depending on the image, there is a light source dependency in which a difference in gloss is felt between the shadow portion and the highlight portion, or the appearance of the image portion changes depending on the light source. These phenomena are also observed with ordinary water-based pigment inks and water-based dye inks. However, at least the colorant, water, and the hydrophilic main chain according to the present invention have a plurality of side chains and are irradiated with active energy rays. In an inkjet ink containing a polymer compound that can be cross-linked between side chains, the polymer compound is cured by active energy rays, and the ink is dried to form an image. Due to changes in the presence state of the dye, gloss difference and light source dependency may be felt strongly.

  It has been found that the difference in gloss and light source dependency can be improved by using two or more kinds of gray inks having different black color material concentrations in the ink set.

  That is, light gray ink is printed in the highlight area, gray ink is printed between the highlight and shadow areas, and gray ink or black ink is printed in the shadow area. It is considered that the dependency due to is reduced.

  Further, by printing light gray ink on the highlight portion, it is possible to reduce the gloss difference between the shadow portion and the highlight portion.

  The black color material may be either a dye or a pigment, but if it is a pigment, particularly carbon black, the effects of the present invention can be more manifested.

  The black color material concentration in the light gray ink is preferably 0.01% or more and less than 0.5%, and the black color material concentration in the gray ink is preferably 0.5% or more and less than 1.5%. If it is out of the above range, the effect of the present invention is not manifested because it is too thin or too dark.

  Since the ink set of the present invention can form a full-color image, it is preferably composed of yellow, magenta, cyan, black, light gray, and gray.

<Active energy ray crosslinkable polymer compound>
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 with active energy rays is a saponified product of polyvinyl acetate, polyvinyl acetal, polyethylene Oxide, polyalkylene oxide, polyvinylpyrrolidone, polyacrylamide, polyacrylic acid, hydroxyethyl cellulose, methyl cellulose, hydroxypropyl cellulose, or a derivative of the hydrophilic resin, and at least one hydrophilic selected from the group consisting of these copolymers In the resin, a modified group such as a photodimerization type, a photodecomposition type, a photopolymerization type, a photomodification type, or a photodepolymerization type is introduced into the side chain. Photopolymerizable crosslinkable groups are desirable from the viewpoints of sensitivity and performance of the generated image.

  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 polymerization degree is preferably 200 or more and 4000 or less, and 200 or more and 2000 or less is more preferable from the viewpoint of handling. preferable. The modification rate of the side chain with respect to the main chain is preferably 0.3 mol% or more and 4 mol% or less, and more preferably 0.8 mol% or more and 4 mol% or less from the viewpoint of reactivity. If it is less than 0.3 mol%, the crosslinkability is insufficient and the effect of the present invention is reduced. If it is more than 4 mol%, the crosslink density is increased and the film is hard and brittle, and the strength of the film is lowered.

  As the photodimerization-type modifying group, those having a diazo group, a cinnamoyl group, a stilbazonium group, a styrylquinolium group or the like introduced are preferable. 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 stilbazonium 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. This 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, a resin represented by the following general formula (5) shown in JP-A Nos. 2000-181062 and 2004-189841 is preferable from the viewpoint of reactivity.

In the formula, R ₂ represents a methyl group or a hydrogen atom, n represents 1 or 2, X represents — (CH ₂ ) _m —COO— or —O—, and Y represents an aromatic ring or a single bond. And m represents an integer from 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.

In the formula, R ₃ represents a methyl group or a hydrogen atom, and R ₄ represents a linear or branched alkylene group having 2 to 10 carbon atoms.

  Such an active energy ray-crosslinking resin is preferably contained in an amount of 0.8% by mass to 5.0% by mass with respect to the total mass of the ink. The presence of 0.8% by mass or more improves cross-linking efficiency, and beading and color bleeding are more preferable due to a rapid increase in ink viscosity after cross-linking. In the case of 5.0% by mass or less, it is difficult to adversely affect the physical properties of the ink and the state in the ink head, which is preferable from the viewpoints of light emission properties and ink storage stability.

  In the active energy ray cross-linking resin of the present invention, the main chain having a certain degree of polymerization is cross-linked through a cross-linking bond between side chains, and thus polymerizes through a general chain reaction. The effect of increasing the molecular weight per photon is significantly larger than that of an active energy ray curable resin. On the other hand, in the conventionally known active energy ray curable resins, the number of crosslinking points cannot be controlled, so the physical properties of the cured film cannot be controlled, and the film tends to be hard and brittle.

  In the resin 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.

  Furthermore, almost all of the conventionally known active energy ray-curable inks other than the colorant 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 resin requires only a small amount, and since there are many dry components, the image quality after drying is improved and the fixing property is also good.

(Photopolymerization initiator, sensitizer)
In the present invention, it is also preferable to add a photopolymerization initiator or a sensitizer. These compounds may be dissolved or dispersed in a solvent, or may be chemically bonded to the photosensitive resin.

  There is no restriction | limiting in particular about the photoinitiator and photosensitizer which are applied, A conventionally well-known thing can be used.

  Although there is no restriction | limiting in particular about the photoinitiator and photosensitizer which are applied, A water-soluble thing is preferable from a viewpoint of mixability and reaction efficiency. In particular, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone (HMPK), 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, HMPK) represented by the following general formula (7) from the viewpoint of compatibility with the resin, The ethylene oxide adduct (n = 2 to 5) is 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 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.

  Even if these photoinitiators are grafted to the side chain with respect to the hydrophilic main chain.

(Active energy rays, irradiation method)
The active energy ray as used in the present invention includes, for example, electron beam, ultraviolet ray, α ray, β ray, γ ray, X ray and the like. However, it is dangerous to human body, easy to handle, and industrially used. Electron beams and ultraviolet rays are widely used.

  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 using ultraviolet rays, the light source is 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, for example, having an operating pressure of 0.1 kPa to 1 MPa. A conventionally well-known thing, such as LED, is used.

(Light irradiation conditions after ink landing)
As the irradiation condition of actinic rays, actinic rays are preferably irradiated between 0.001 and 1.0 seconds after ink landing, and more preferably 0.001 to 0.5 seconds. In order to form a high-definition image, it is particularly important that the irradiation timing is as early as possible.

(Installation of lamp)
As a method for irradiating actinic rays, the basic method is disclosed in JP-A-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 applying a collimated light source to a mirror surface provided on the side of the head unit and irradiating the recording unit with UV light is disclosed. Yes. Any of these irradiation methods can be used in the image forming method of the present invention.

  In another preferred embodiment, irradiation with actinic rays is divided into two stages, and actinic rays are first irradiated by the above-described method between 0.001 and 2.0 seconds after ink landing, and further irradiated with actinic rays. It is. By dividing the irradiation of actinic rays into two stages, it is possible to further suppress the shrinkage of the recording material that occurs during ink curing.

(Colorant)
As the color material used in the ink jet ink of the present invention, it is preferable to use a dye or a pigment.

(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.

  Specific examples of dyes applicable to the ink jet ink of the present invention are listed below, but the present invention is not limited to these exemplified dyes.

[Water-soluble dye]
Examples of water-soluble dyes that can be used in the present invention include azo dyes, methine dyes, azomethine dyes, xanthene dyes, quinone dyes, phthalocyanine dyes, triphenylmethane dyes, and diphenylmethane dyes.

<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. Basic Yellow>
1, 2, 11, 13, 15, 19, 21, 28, 29, 32, 36, 40, 41, 45, 51, 63, 67, 70, 73, 91,
<C. I. Basic Orange>
2, 21, 22,
<C. I. Basic Red>
1, 2, 12, 13, 14, 15, 18, 23, 24, 27, 29, 35, 36, 39, 46, 51, 52, 69, 70, 73, 82, 109,
<C. I. Basic Violet>
1, 3, 7, 10, 11, 15, 16, 21, 27, 39,
<C. I. Basic Blue>
1, 3, 7, 9, 21, 22, 26, 41, 45, 47, 52, 54, 65, 69, 75, 77, 92, 100, 105, 117, 124, 129, 147, 151,
<C. I. Basic Green>
1, 4,
<C. I. Basic Brown>
1,
<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.

  Furthermore, examples of the dye include a compound represented by the following general formula (8) or a compound represented by the general formula (9).

In the general formula (8), R ₁ represents a hydrogen atom or a substitutable substituent, and is preferably a hydrogen atom or a phenylcarbonyl group. R ₂ may be different and represents a hydrogen atom or a substitutable substituent, and is preferably a hydrogen atom. R ₃ represents a hydrogen atom or a substitutable substituent, and is preferably a hydrogen atom or an alkyl group. R ₄ represents a hydrogen atom or a substitutable substituent, preferably a hydrogen atom or an aryloxy group. R ₅ may be different and represents a hydrogen atom or a substitutable substituent, and is preferably a sulfonic acid group. n represents an integer of 1 to 4, and m represents an integer of 1 to 5.

  In the general formula (9), X represents a phenyl group or a naphthyl group, may be substituted with a substitutable substituent, and is preferably substituted with a sulfonic acid group or a carboxyl group. Y represents hydrogen ion, sodium ion, potassium ion, lithium ion, ammonium ion or alkylammonium ion. Re may be different and represents a hydrogen atom or a substituent that can be substituted on the naphthalene ring. q represents 1 or 2. p represents an integer of 1 to 4. However, q + p = 5. Z represents a substitutable substituent, and represents a carbonyl group, a sulfonyl group or a group represented by the following general formula (10), and particularly preferably a group represented by the following general formula (10).

In the general formula (10), W ₁ and W ₂ each independently represent a halogen atom, amino group, hydroxyl group, alkylamino group or arylamino group, preferably a halogen atom, hydroxyl group or alkylamino group.

[Disperse dye]
As the disperse dye, various disperse dyes such as azo disperse dyes, quinone disperse dyes, anthraquinone disperse dyes, quinophthalone disperse dyes can be used, and specific compounds thereof are listed below.

<C. I. Disperse Yellow>
3, 4, 5, 7, 9, 13, 23, 24, 30, 33, 34, 42, 44, 49, 50, 51, 54, 56, 58, 60, 63, 64, 66, 68, 71, 74, 76, 79, 82, 83, 85, 86, 88, 90, 91, 93, 98, 99, 100, 104, 108, 114, 116, 118, 119, 122, 124, 126, 135, 140, 141, 149, 160, 162, 163, 164, 165, 179, 180, 182, 183, 184, 186, 192, 198, 199, 202, 204, 210, 211, 215, 216, 218, 224, 227, 231, 232,
<C. I. Disperse Orange>
1, 3, 5, 7, 11, 13, 17, 20, 21, 25, 29, 30, 31, 32, 33, 37, 38, 42, 43, 44, 45, 47, 48, 49, 50, 53, 54, 55, 56, 57, 58, 59, 61, 66, 71, 73, 76, 78, 80, 89, 90, 91, 93, 96, 97, 119, 127, 130, 139, 142,
<C. I. Disperse Red>
1, 4, 5, 7, 11, 12, 13, 15, 17, 27, 43, 44, 50, 52, 53, 54, 55, 56, 58, 59, 60, 65, 72, 73, 74, 75, 76, 78, 81, 82, 86, 88, 90, 91, 92, 93, 96, 103, 105, 106, 107, 108, 110, 111, 113, 117, 118, 121, 122, 126, 127, 128, 131, 132, 134, 135, 137, 143, 145, 146, 151, 152, 153, 154, 157, 159, 164, 167, 169, 177, 179, 181, 183, 184, 185, 188, 189, 190, 191, 192, 200, 201, 202, 203, 205, 206, 207, 210, 221, 224, 225, 227, 229, 23 , 240,257,258,277,278,279,281,288,298,302,303,310,311,312,320,324,328,
<C. I. Disperse Violet>
1, 4, 8, 23, 26, 27, 28, 31, 33, 35, 36, 38, 40, 43, 46, 48, 50, 51, 52, 56, 57, 59, 61, 63, 69, 77,
<C. I. Disperse Green>
9,
<C. I. Disperse Brown>
1, 2, 4, 9, 13, 19,
<C. I. Disperse Blue>
3, 7, 9, 14, 16, 19, 20, 26, 27, 35, 43, 44, 54, 55, 56, 58, 60, 62, 64, 71, 72, 73, 75, 79, 81, 82, 83, 87, 91, 93, 94, 95, 96, 102, 106, 108, 112, 113, 115, 118, 120, 122, 125, 128, 130, 139, 141, 142, 143, 146, 148, 149, 153, 154, 158, 165, 167, 171, 173, 174, 176, 181, 183, 185, 186, 187, 189, 197, 198, 200, 201, 205, 207, 211, 214, 224, 225, 257, 259, 267, 268, 270, 284, 285, 287, 288, 291, 293, 295, 297, 301, 315, 3 0,333,
<C. I. Disperse Black>
1, 3, 10, 24
Etc.

[Pigment]
As the pigment that can be used in the present invention, conventionally known organic and inorganic pigments can be used, but they are anionic 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 cyclic pigments, dye lakes such as acid dye lakes, organic pigments such as nitro pigments, nitroso pigments, aniline black, and daylight fluorescent pigments, and inorganic pigments such as carbon black.

  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.

  As a method for dispersing the pigment, for example, various dispersing machines such as 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, and a paint shaker 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 ink according to the present invention, a self-dispersed pigment in which polar groups such as sulfonic acid and carboxylic acid are pendant on the pigment surface, or a pigment dispersed using a polymer dispersant is preferable.

  The polymer dispersant according to the present invention is not particularly limited, and a water-soluble resin or a water-insoluble resin is used. Examples of these polymers include styrene, styrene derivatives, vinyl naphthalene derivatives, acrylic acid, acrylic acid derivatives, methacrylic acid, methacrylic acid derivatives, maleic acid, maleic acid derivatives, itaconic acid, itaconic acid derivatives, fumaric acid, fumaric acid. Examples thereof include a polymer composed of a single monomer selected from acid derivatives, a copolymer composed of two or more monomers, and salts thereof. Water-soluble polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, cellulose derivatives, gelatin, and polyethylene glycol can also be used.

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

  The average particle size of the pigment dispersion used in the inkjet ink of the present invention is preferably 500 nm or less, more preferably 200 nm or less, preferably 10 nm or more and 200 nm or less, and more preferably 10 nm or more and 150 nm or less. If the average particle size of the pigment dispersion exceeds 500 nm, the dispersion becomes unstable. In addition, even when the average particle size of the pigment dispersion is less than 10 nm, the stability of the pigment dispersion tends to deteriorate, and the storage stability of the ink tends to deteriorate.

  The particle size of the pigment dispersion can be determined by a commercially available particle size measuring device using a light scattering method, an electrophoresis method, a laser Doppler method or the like. It is also possible to obtain a particle image with a transmission electron microscope on at least 100 particles and perform statistical processing on the image using image analysis software such as Image-Pro (manufactured by Media Cybernetics). Is possible.

  Various methods such as 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, and a paint shaker can be used as a pigment dispersion method.

(Water-soluble solvent)
As the solvent according to the present invention, an aqueous liquid medium is preferably used, and as the aqueous liquid medium, a mixed solvent such as water and a water-soluble organic solvent is further 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)
Surfactants preferably used in the ink of the present invention include alkyl sulfates, alkyl ester sulfates, dialkyl sulfosuccinates, alkyl naphthalene sulfonates, alkyl phosphates, polyoxyalkylene alkyl ether phosphates, fatty acids. Anionic surfactants such as salts, nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyalkylene alkyl phenyl ethers, acetylene glycols, polyoxyethylene-polyoxypropylene block copolymers, glycerin esters, sorbitan Activators such as esters, polyoxyethylene fatty acid amides and amine oxides, and cationic surfactants such as alkylamine salts and quaternary ammonium salts.

  These surfactants can also be used as pigment dispersants, and in particular, anionic and nonionic surfactants can be preferably used.

(latex)
In the inkjet ink of the present invention, latex may be added to the ink. Examples thereof include latex such as styrene-butadiene copolymer, polystyrene, acrylonitrile-butadiene copolymer, acrylic ester copolymer, polyurethane, silicon-acrylic copolymer, and acrylic-modified fluororesin. The latex may be obtained by dispersing polymer particles using an emulsifier, or may be dispersed without using an emulsifier. A surfactant is often used as an emulsifier, but a polymer having a water-soluble group such as a sulfonic acid group or a carboxylic acid group (for example, a polymer in which a solubilizing group is graft-bonded, a single group having a solubilizing group). It is also preferable to use a polymer obtained from a monomer and a monomer having an insoluble part.

  Moreover, it is particularly preferable to use soap-free latex in the ink jet ink of the present invention. Soap-free latex is a latex that does not use an emulsifier and a polymer having a water-soluble group such as a sulfonic acid group or a carboxylic acid group (for example, a polymer in which a solubilizing group is graft-bonded, a solubilizing group) It is a latex using a polymer obtained from a monomer having an insoluble part and a monomer having an insoluble part as an emulsifier.

  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.

  In the inkjet ink of the present invention, the average particle size of the polymer particles in the latex is preferably 10 nm or more and 300 nm or less, and more preferably 10 nm or more and 100 nm or less. When the average particle size of the latex exceeds 300 nm, the glossiness of the image is deteriorated, and when it is less than 10 nm, the water resistance and scratch resistance become insufficient. The average particle size of the polymer particles in the latex can be determined by a commercially available particle size measuring instrument using a light scattering method, an electrophoresis method, or a laser Doppler method.

  In the inkjet ink of the present invention, the latex is preferably added so that the solid content is 0.1% by mass or more and 20% by mass or less with respect to the total mass of the ink. It is particularly preferable that the content be 0.5 mass% or more and 10% mass% or less. If the amount of latex solids added is less than 0.1% by mass, it is difficult to exert a sufficient effect on the weather resistance, and if it exceeds 20% by mass, the ink viscosity increases over time and the ink storage stability is increased. There are many problems that arise.

(Outgoing stabilizer for thermal)
The ink jet ink of the present invention may be used in a thermal ink jet printer. At this time, in order to solve the clogging of the head called gogging, (M ¹ ) ₂ SO ₄ , CH ₃ COO (M ¹ ), Ph-COO (M ¹ ) disclosed in Japanese Patent Laid-Open No. 2001-81379. , (M ¹ ) NO ₃ , (M ¹ ) Cl, (M ¹ ) Br, (M ¹ ) I, (M ¹ ) ₂ SO ₃ and (M ¹ ) ₂ CO ₃ may be added. . Here, M ¹ represents an alkali metal, ammonium or organic ammonium, and Ph represents a phenyl group. Examples of the alkali metal include Li, Na, K, Rb, and Cs. Examples of organic ammonium include methylammonium, dimethylammonium, trimethylammonium, ethylammonium, diethylammonium, triethylammonium, trihydroxymethylamine, dihydroxymethylamine, monohydroxymethylamine, monoethanolammonium, diethanolammonium, and triethanol. Ammonium, N-methylmonoethanolammonium, N-methyldiethanolammonium, monopropanolammonium, dipropanolammonium, tripropanolammonium, etc. are mentioned.

(Various additives)
In the present invention, other conventionally known additives can be contained. For example, optical brighteners, antifoaming agents, lubricants, preservatives, thickeners, antistatic agents, matting agents, water-soluble polyvalent metal salts, acid bases, pH adjusters such as buffer solutions, antioxidants, surface tension It is a regulator, a non-resistance modifier, a rust inhibitor, an inorganic pigment, and the like.

<Recording sheet>
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. Further details are described in detail in the “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.

<Various films>
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.

<Various inkjet recording media>
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 of the present invention will be described below, but the present invention is not limited to these examples. In the examples, “%” represents mass% unless otherwise specified.

<Synthesis of Polymer Compound 1>
56 g of glycidyl methacrylate, 48 g of p-hydroxybenzaldehyde, 2 g of pyridine, and 1 g of N-nitroso-phenylhydroxyamine ammonium salt were each put in a reaction vessel and stirred in a hot water bath at 80 ° C. for 8 hours.

  Next, 45 g of a polyvinyl acetate saponified product having a polymerization degree of 300 and a saponification degree 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-2-hydroxypropyloxy) benzaldehyde was added under the condition that the modification rate was 3 mol% with respect to the saponified polyvinyl acetate, and the mixture was stirred at 90 ° C. for 6 hours. After cooling the resulting solution to room temperature, 30 g of basic ion exchange resin was added and stirred for 1 hour. Next, the ion exchange resin was filtered, and Irgacure 2959 (manufactured by Ciba Specialty Chemicals) was mixed here as a photopolymerization initiator at a ratio of 0.1 g with respect to 100 g of a 15% aqueous solution. Dilution gave a 12% aqueous solution of polymer compound 1.

<Synthesis of polymer compound 2>
In the synthesis of polymer compound 1, polymer compound 1 except that the amount of p- (3-methacryloxy-2-hydroxypropyloxy) benzaldehyde was changed to change the crosslinking group modification rate of the polyvinyl acetate saponified product to 0.4 mol%. In the same manner, a 12% aqueous solution of polymer compound 2 was obtained.

<Synthesis of Polymer Compound 3>
A 12% aqueous solution of polymer compound 2 was obtained in the same manner as polymer compound 1 except that the crosslinking group modification rate of the polyvinyl acetate saponified product was changed to 4.5 mol% in the synthesis of polymer compound 1.

<Synthesis of Polymer Compound 4>
A 12% aqueous solution of polymer compound 4 was obtained in the same manner as polymer compound 1 except that the polymerization degree of polyvinyl acetate saponified product was changed to 180 in the synthesis of polymer compound 1.

<Synthesis of Polymer Compound 5>
A 5% aqueous solution of polymer compound 5 was obtained in the same manner as polymer compound 1 except that the polymerization degree of polyvinyl acetate saponified product was changed to 4500 in the synthesis of polymer compound 1.

<Synthesis of Polymer Compound 6>
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 the mixture was stirred for 24 hours while maintaining at 60 ° C. After raising methanol temperature to 95 ° C. and distilling off methanol while adding water, it was treated with an ion exchange resin (Mitsubishi Chemical: PK-216H) to remove pyridine to give an aqueous solution with a nonvolatile content of 15%. Obtained. As a photopolymerization initiator, Irgacure 2959 (manufactured by Ciba Specialty Chemicals) was mixed at a ratio of 0.1 g to 100 g of a 15% aqueous solution, and then diluted with ion-exchanged water to obtain 10% of the polymer compound 6. Obtained.

<Preparation of ink>
(Preparation of pigment dispersion)
(Yellow pigment dispersion)
The following additives were mixed and dispersed using a sand grinder filled with 0.5 mm zirconia beads at a volume ratio of 50% to prepare a yellow pigment dispersion having a yellow pigment content of 10%.

C. I. Pigment Yellow 74 95g
Demall C (Kao Corporation) 65g
Ethylene glycol 100g
Ion exchange water 120g
(Preparation of magenta pigment dispersion)
The following additives were mixed and dispersed using a sand grinder filled with 50% by volume of 0.5 mm zirconia beads to prepare a magenta pigment dispersion having a magenta pigment content of 10%. The average particle size of the magenta pigment particles contained in this magenta pigment dispersion was 83 nm. The particle size was measured using a Zetasizer 1000HS manufactured by Malvern.

C. I. Pigment Red 122 10 parts Jonkrill 61 (acrylic styrene resin dispersant, manufactured by Johnson) 3 parts Glycerin 15 parts Ion-exchanged water 72 parts (Cyan pigment dispersion)
The following additives were mixed and dispersed using a sand grinder filled with 50% by volume of 0.5 mm zirconia beads to prepare a cyan pigment dispersion having a cyan pigment content of 10%.

C. I. Pigment Blue 15: 3 100g
DEMAL C 68g
Diethylene glycol 100g
125g of ion exchange water
(Black pigment dispersion)
The following additives were mixed and dispersed using a sand grinder filled with 50% by volume of 0.5 mm zirconia beads to prepare a black pigment dispersion having a black pigment content of 10%.

Talker Black # 8500 (Tokai Carbon Co., Ltd.) 120g
Jongkrill 62 (Johnson Polymer Co., Ltd.) 59g
Lebenol WX (Kao Corporation) 3g
Diethylene glycol 100g
Ion exchange water 300g
Hereinafter, pigment-type ink sets 1 to 12 were produced.

<< Preparation of ink set 1 >>
Ink set 1 composed of yellow ink Y1, magenta ink M1, cyan ink C1, black ink K1, gray ink Gr1, and light gray ink LGr1 was produced as follows.

(Preparation of yellow ink Y1)
Yellow pigment dispersion 30 parts 12% aqueous solution of polymer compound 1 17 parts Glycerol 7 parts Ethylene glycol 15 parts Diethylene glycol monobutyl ether 2 parts Orphine e1010 (manufactured by Nissin Chemical Co., Ltd.) 0.2 parts Was 100 parts, and yellow ink Y1 was produced.

(Preparation of magenta ink M1)
Magenta ink M1 was produced in the same manner as yellow ink Y1, except that the yellow pigment dispersion was changed to a magenta pigment dispersion in the production of yellow ink Y1.

(Preparation of cyan ink C1)
A cyan ink C1 was produced in the same manner as the yellow ink Y1, except that the yellow pigment dispersion was changed to a cyan pigment dispersion in the production of the yellow ink Y1.

(Preparation of black ink K1)
Black pigment dispersion 30 parts 12% aqueous solution of polymer compound 1 17 parts Glycerol 7 parts Ethylene glycol 15 parts Diethylene glycol monobutyl ether 2 parts Olfine e1010 (manufactured by Nissin Chemical Co., Ltd.) 0.2 parts Was 100 parts, and a black ink K1 was produced.

(Preparation of gray ink Gr1)
A gray ink Gr1 was produced in the same manner as the black ink KI except that the black pigment dispersion was changed to 10 parts in the production of the black ink K1.

(Production of light gray ink LGr1)
A light gray ink LGr1 was produced in the same manner as the black ink KI except that the black pigment dispersion was changed to 2 parts in the production of the black ink K1.

<< Preparation of ink set 2 >>
Ink set 2 including yellow ink Y2, magenta ink M2, cyan ink C2, black ink K2, gray ink Gr2, and light gray ink LGr2 was produced as follows.

(Preparation of yellow ink Y2)
A yellow ink Y2 was prepared in the same manner as in the preparation of the yellow ink Y1, except that a 12% aqueous solution of the polymer compound 2 was used instead of the 12% aqueous solution of the polymer compound 1.

(Preparation of magenta ink M2)
Magenta ink M2 was produced in the same manner as in the production of magenta ink M1, except that a 12% aqueous solution of polymer compound 2 was used instead of the 12% aqueous solution of polymer compound 1.

(Preparation of cyan ink C2)
Cyan ink C2 was prepared in the same manner as in the preparation of cyan ink C1, except that a 12% aqueous solution of polymer compound 2 was used instead of the 12% aqueous solution of polymer compound 1.

(Preparation of black ink K2)
Black ink K2 was produced in the same manner as in the production of black ink K1, except that a 12% aqueous solution of polymer compound 2 was used instead of the 12% aqueous solution of polymer compound 1.

(Preparation of gray ink Gr2)
Gray ink Gr2 was prepared in the same manner as in the preparation of gray ink Gr1, except that a 12% aqueous solution of polymer compound 2 was used instead of the 12% aqueous solution of polymer compound 1.

(Preparation of light gray ink LGr2)
Light gray ink LGr2 was prepared in the same manner as in the preparation of light gray ink LGr1, except that a 12% aqueous solution of polymer compound 2 was used instead of the 12% aqueous solution of polymer compound 1.

<< Preparation of ink set 3 >>
Ink set 3 including yellow ink Y3, magenta ink M3, cyan ink C3, black ink K3, gray ink Gr3, and light gray ink LGr3 was produced as follows.

(Preparation of yellow ink Y3)
A yellow ink Y3 was prepared in the same manner as in the preparation of the yellow ink Y1, except that a 12% aqueous solution of the polymer compound 3 was used instead of the 12% aqueous solution of the polymer compound 1.

(Preparation of magenta ink M3)
Magenta ink M3 was prepared in the same manner as in the preparation of magenta ink M1, except that a 12% aqueous solution of polymer compound 3 was used instead of the 12% aqueous solution of polymer compound 1.

(Preparation of cyan ink C3)
Cyan ink C3 was prepared in the same manner as in the preparation of cyan ink C1, except that a 12% aqueous solution of polymer compound 3 was used instead of the 12% aqueous solution of polymer compound 1.

(Preparation of black ink K3)
Black ink K3 was prepared in the same manner as in the production of black ink K1, except that a 12% aqueous solution of polymer compound 3 was used instead of the 12% aqueous solution of polymer compound 1.

(Preparation of gray ink Gr3)
Gray ink Gr3 was produced in the same manner as in the production of gray ink Gr1, except that a 12% aqueous solution of polymer compound 3 was used instead of the 12% aqueous solution of polymer compound 1.

(Production of light gray ink LGr3)
Light gray ink LGr3 was prepared in the same manner as in the preparation of light gray ink LGr1, except that a 12% aqueous solution of polymer compound 3 was used instead of the 12% aqueous solution of polymer compound 1.

<< Preparation of ink set 4 >>
Ink set 4 composed of yellow ink Y4, magenta ink M4, cyan ink C4, black ink K4, gray ink Gr4, and light gray ink LGr4 was produced as follows.

(Preparation of yellow ink Y4)
A yellow ink Y4 was prepared in the same manner as in the preparation of the yellow ink Y1, except that a 12% aqueous solution of the polymer compound 4 was used instead of the 12% aqueous solution of the polymer compound 1.

(Preparation of magenta ink M4)
Magenta ink M4 was produced in the same manner as in the production of magenta ink M1, except that a 12% aqueous solution of polymer compound 4 was used instead of the 12% aqueous solution of polymer compound 1.

(Preparation of cyan ink C4)
Cyan ink C4 was prepared in the same manner as in the preparation of cyan ink C1, except that a 12% aqueous solution of polymer compound 4 was used instead of the 12% aqueous solution of polymer compound 1.

(Preparation of black ink K4)
A black ink K4 was produced in the same manner as in the production of the black ink K1, except that a 12% aqueous solution of the polymer compound 4 was used instead of the 12% aqueous solution of the polymer compound 1.

(Preparation of gray ink Gr4)
Gray ink Gr4 was produced in the same manner as in the production of gray ink Gr1, except that a 12% aqueous solution of polymer compound 4 was used instead of the 12% aqueous solution of polymer compound 1.

(Production of light gray ink LGr4)
Light gray ink LGr4 was prepared in the same manner as in the preparation of light gray ink LGr1, except that a 12% aqueous solution of polymer compound 4 was used instead of the 12% aqueous solution of polymer compound 1.

<< Preparation of ink set 5 >>
Ink set 5 including yellow ink Y5, magenta ink M5, cyan ink C5, black ink K5, gray ink Gr5, and light gray ink LGr5 was produced as follows.

(Preparation of yellow ink Y5)
Yellow pigment dispersion 30 parts 5% aqueous solution of polymer compound 5 40 parts Glycerol 7 parts Ethylene glycol 15 parts Diethylene glycol monobutyl ether 2 parts Orphine e1010 (manufactured by Nissin Chemical Co., Ltd.) 0.2 parts Was 100 parts, and yellow ink Y5 was produced.

(Preparation of magenta ink M5)
A magenta ink M5 was produced in the same manner as the yellow ink Y5 except that the yellow pigment dispersion was changed to a magenta pigment dispersion in the production of the yellow ink Y5.

(Preparation of cyan ink C5)
A cyan ink C5 was produced in the same manner as the yellow ink Y5 except that the yellow pigment dispersion was changed to a cyan pigment dispersion in the production of the yellow ink Y5.

(Preparation of black ink K5)
Black pigment dispersion 30 parts 5% aqueous solution of polymer compound 5 40 parts Glycerol 7 parts Ethylene glycol 15 parts Diethylene glycol monobutyl ether 2 parts Orphine e1010 (manufactured by Nissin Chemical Co., Ltd.) 0.2 parts Was 100 parts, and a black ink K5 was produced.

(Preparation of gray ink Gr5)
A gray ink Gr5 was produced in the same manner as the black ink K5 except that the black pigment dispersion was changed to 10 parts in the production of the black ink K5.

(Production of light gray ink LGr5)
A light gray ink LGr5 was produced in the same manner as the black ink K5 except that the black pigment dispersion was changed to 2 parts in the production of the black ink K5.

<< Preparation of ink set 6 >>
Ink set 6 including yellow ink Y6, magenta ink M6, cyan ink C6, black ink K6, gray ink Gr6, and light gray ink LGr6 was produced as follows.

(Preparation of yellow ink Y6)
Yellow pigment dispersion 30 parts 12% aqueous solution of polymer compound 1 4.2 parts Glycerol 7 parts Ethylene glycol 15 parts Diethylene glycol monobutyl ether 2 parts Orphine e1010 (manufactured by Nissin Chemical) 0.2 parts In addition, the total amount was 100 parts, and yellow ink Y6 was produced.

(Preparation of magenta ink M6)
A magenta ink M6 was produced in the same manner as the yellow ink Y6 except that the yellow pigment dispersion was changed to a magenta pigment dispersion in the production of the yellow ink Y6.

(Preparation of cyan ink C6)
Cyan ink C6 was produced in the same manner as yellow ink Y6 except that the yellow pigment dispersion was changed to a cyan pigment dispersion in the production of yellow ink Y6.

(Preparation of black ink K6)
A black ink K6 was produced in the same manner as the yellow ink Y6 except that the yellow pigment dispersion was changed to a black pigment dispersion in the production of the yellow ink Y6.

(Preparation of gray ink Gr6)
A gray ink Gr6 was produced in the same manner as the black ink K6 except that the black pigment dispersion was changed to 10 parts in the production of the black ink K6.

(Production of light gray ink LGr6)
A light gray ink LGr6 was produced in the same manner as the black ink K6 except that the black pigment dispersion was changed to 2 parts in the production of the black ink K6.

<< Preparation of ink set 7 >>
An ink set 7 composed of yellow ink Y7, magenta ink M7, cyan ink C7, black ink K7, gray ink Gr7, and light gray ink LGr7 was produced as follows.

(Preparation of yellow ink Y7)
Yellow pigment dispersion 30 parts 12% aqueous solution of polymer compound 1 43 parts Glycerol 7 parts Ethylene glycol 15 parts Diethylene glycol monobutyl ether 2 parts Olfine e1010 (manufactured by Nissin Chemical Co., Ltd.) 0.2 parts Was 100 parts, and yellow ink Y7 was produced.

(Preparation of magenta ink M7)
A magenta ink M7 was produced in the same manner as the yellow ink Y7 except that the yellow pigment dispersion was changed to a magenta pigment dispersion in the production of the yellow ink Y7.

(Preparation of cyan ink C7)
A cyan ink C7 was produced in the same manner as the yellow ink Y7 except that the yellow pigment dispersion was changed to a cyan pigment dispersion in the production of the yellow ink Y7.

(Preparation of black ink K7)
A black ink K7 was produced in the same manner as the yellow ink Y7 except that the yellow pigment dispersion was changed to a black pigment dispersion in the production of the yellow ink Y7.

(Preparation of gray ink Gr7)
A gray ink Gr7 was produced in the same manner as the black ink K7 except that the black pigment dispersion was changed to 10 parts in the production of the black ink K7.

(Production of light gray ink LGr7)
A light gray ink LGr7 was produced in the same manner as the black ink K7 except that the black pigment dispersion was changed to 2 parts in the production of the black ink K7.

<< Preparation of ink set 8 >>
Ink set 8 composed of yellow ink Y8, magenta ink M8, cyan ink C8, black ink K8, gray ink Gr8, and light gray ink LGr8 was produced as follows.

(Preparation of yellow ink Y8)
Yellow pigment dispersion 30 parts 10% aqueous solution of polymer compound 6 20 parts Glycerol 7 parts Ethylene glycol 15 parts Diethylene glycol monobutyl ether 2 parts Olfine e1010 (manufactured by Nissin Chemical Co., Ltd.) 0.2 parts Was 100 parts, and yellow ink Y8 was produced.

(Preparation of magenta ink M8)
A magenta ink M8 was produced in the same manner as the yellow ink Y8 except that the yellow pigment dispersion was changed to a magenta pigment dispersion in the production of the yellow ink Y8.

(Preparation of cyan ink C8)
Cyan ink C8 was produced in the same manner as yellow ink Y8 except that the yellow pigment dispersion was changed to a cyan pigment dispersion in the production of yellow ink Y8.

(Preparation of black ink K8)
A black ink K8 was produced in the same manner as the yellow ink Y8 except that the yellow pigment dispersion was changed to a black pigment dispersion in the production of the yellow ink Y8.

(Preparation of gray ink Gr8)
A gray ink Gr8 was produced in the same manner as the black ink K8 except that the black pigment dispersion was changed to 10 parts in the production of the black ink K8.

(Production of light gray ink LGr8)
A light gray ink LGr8 was produced in the same manner as the black ink K8 except that the black pigment dispersion was changed to 2 parts in the production of the black ink K8.

<< Preparation of ink set 9 >>
Ink set 9 composed of yellow ink Y9, magenta ink M9, cyan ink C9, black ink K9, gray ink Gr9, and light gray ink LGr9 was produced as follows.

(Preparation of yellow ink Y9)
Yellow pigment dispersion 30 parts RSP manufactured by Toyo Gosei Kogyo Co., Ltd. 20 parts Glycerin 7 parts Ethylene glycol 15 parts Diethylene glycol monobutyl ether 2 parts Orphine e1010 (manufactured by Nissin Chemical) 0.2 parts In addition, the total amount was 100 parts, and yellow ink Y9 was produced.

(Preparation of magenta ink M9)
A magenta ink M9 was produced in the same manner as the yellow ink Y9 except that the yellow pigment dispersion was changed to a magenta pigment dispersion in the production of the yellow ink Y9.

(Preparation of cyan ink C9)
Cyan ink C9 was produced in the same manner as yellow ink Y9 except that the yellow pigment dispersion was changed to a cyan pigment dispersion in the production of yellow ink Y9.

(Preparation of black ink K9)
A black ink K9 was produced in the same manner as the yellow ink Y9 except that the yellow pigment dispersion was changed to a black pigment dispersion in the production of the yellow ink Y9.

(Preparation of gray ink Gr9)
A gray ink Gr9 was produced in the same manner as the black ink K9 except that the black pigment dispersion was changed to 10 parts in the production of the black ink K9.

(Production of light gray ink LGr9)
A light gray ink LGr9 was produced in the same manner as the black ink K9 except that the black pigment dispersion was changed to 2 parts in the production of the black ink K9.

<< Preparation of ink set 10 >>
An ink set 10 composed of yellow ink Y1, magenta ink M1, cyan ink C1, black ink K1, and gray ink Gr1 was produced.

<< Preparation of ink set 11 >>
An ink set 11 composed of yellow ink Y1, magenta ink M1, cyan ink C1, black ink K1, and light gray ink LGr1 was produced.

<< Preparation of ink set 12 >>
An ink set 12 including a yellow ink Y1, a magenta ink M1, a cyan ink C1, and a black ink K1 was produced.

  Hereinafter, dye-type ink sets 13 and 14 were produced.

<< Preparation of ink set 13 >>
An ink set 13 composed of yellow ink Y11, magenta ink M11, cyan ink C11, black ink K11, gray ink Gr11, and light gray ink LGr11 was produced as follows.

(Preparation of yellow ink Y11)
C. I. Acid Yellow 23 3 parts 12% aqueous solution of polymer compound 1 17 parts Glycerol 7 parts Ethylene glycol 15 parts Diethylene glycol monobutyl ether 2 parts Olfine e1010 (manufactured by Nissin Chemical Co., Ltd.) 0.2 parts A yellow ink Y11 was produced.

(Preparation of magenta ink M11)
In the production of the yellow ink Y11, C.I. I. Acid Yellow 23 is C.I. I. A magenta ink M11 was produced in the same manner as the yellow ink Y11, except that it was changed to Direct Red 227.

(Preparation of cyan ink C11)
In the production of the yellow ink Y11, C.I. I. Acid Yellow 23 is C.I. I. A cyan ink C11 was produced in the same manner as the yellow ink Y11, except that the color was changed to Direct Blue 199.

(Preparation of black ink K11)
C. I. Food Black2 4 parts 12% aqueous solution of polymer compound 1 17 parts Glycerol 7 parts Ethylene glycol 15 parts Diethylene glycol monobutyl ether 2 parts Orphine e1010 (manufactured by Nissin Chemical Co., Ltd.) 0.2 parts A black ink K11 was produced.

(Preparation of gray ink Gr11)
In the production of the black ink K11, C.I. I. A gray ink Gr11 was produced in the same manner as the black ink K11, except that 1 part of Food Black 2 was used.

(Production of light gray ink LGr11)
In the production of the black ink K11, C.I. I. A light gray ink LGr11 was produced in the same manner as the black ink K11 except that 0.2 parts of Food Black 2 was used.

<< Preparation of ink set 14 >>
An ink set 14 composed of yellow ink Y11, magenta ink M11, cyan ink C11, and black ink K11 was produced.

  The following evaluations were performed for ink sets 1 to 14.

(Evaluation of beading resistance)
Using an on-demand type ink jet printer with a maximum recording density of 720 × 720 dpi using a piezo-type 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) ) 5 cm × 5 cm magenta solid was printed and visually observed, and beading resistance was evaluated according to the following criteria.

  In addition, each ink was continuously ejected, and 0.1 seconds after landing, 120 W / cm metal halide lamps (MAL 400NL manufactured by Nihon Battery Co., Ltd., power supply power 3 kW · hr) disposed at both ends of the piezoelectric head were irradiated.

◎: Uniform image ○: Mottled noise that can be seen when viewed closely is present in less than 5 points Δ: Mottled noise that can be understood when viewed carefully is present in less than 10 points ×: Clear mottled noise is 10 Existence of more than one place XX: There are more than 20 mottled noises. Among these, XX and XX are levels at which there is a problem as a product.

(Evaluation of bleed resistance)
Using an on-demand type ink jet printer with a maximum recording density of 720 × 720 dpi using a piezo-type 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) ), A black thin line having a width of 200 μm was printed on a magenta solid, and then visually observed, and bleed resistance was evaluated according to the following criteria.

  In addition, each ink was continuously ejected, and 0.1 seconds after landing, 120 W / cm metal halide lamps (MAL 400NL manufactured by Nihon Battery Co., Ltd., power supply power 3 kW · hr) disposed at both ends of the piezoelectric head were irradiated.

◎: The boundary between the fine line and the solid is clear. ○: The boundary is slightly blurred, but there is no problem in practical use. △: The boundary is blurred, but practically acceptable. X: Obvious blurring is observed at the boundary, the line width is about 1.5 times, and this is a quality that is a practical problem. XX: The boundary between the fine line and the solid part is unclear. Quality and extremely low bleed resistance (Evaluation of light source dependency)
Using an on-demand type ink jet printer with a maximum recording density of 720 × 720 dpi using a piezo-type 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) ) N4 “Wine and tableware” of high-definition color digital standard image conforming to JIS X 9201-1995 is printed and visually observed under halogen light and tungsten light, respectively, and light source dependency is evaluated according to the following criteria. It was.

  In addition, each ink was continuously ejected, and after landing for 0.1 seconds, 120 W / cm metal halide lamps (MAL 400NL power supply power 3 kW · hr, manufactured by Nihon Battery Co., Ltd.) disposed at both ends of the piezoelectric head were irradiated.

○: The difference between the light source between the halogen light and the tungsten light is small and natural. Δ: The difference between the light source between the halogen light and the tungsten light is felt, but the acceptable level. X: The difference between the light source between the halogen light and the tungsten light is felt strongly. .

(Evaluation of glossiness)
Using an on-demand type ink jet printer with a maximum recording density of 720 × 720 dpi using a piezo-type 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) ) N1 “Portrait” of a high-definition color digital standard image conforming to JIS X 9201-1995 was printed, visually observed, and glossiness was evaluated according to the following criteria.

  In addition, each ink was continuously ejected, and after landing for 0.1 seconds, 120 W / cm metal halide lamps (MAL 400NL power supply power 3 kW · hr, manufactured by Nihon Battery Co., Ltd.) disposed at both ends of the piezoelectric head were irradiated.

◎: There is almost no difference in gloss between the highlight part and the shadow part, and it is natural. ○: The highlight part and the shadow part are slightly different in gloss, but an acceptable level. △: The highlight part and the shadow part are slightly different in gloss. It can be visually observed, and the glossiness of the recording surface is remarkably higher than that of the background. ×: It can be visually observed that the glossiness of the highlight portion and the shadow portion is clearly different, and the glossiness of the recording surface is remarkably higher than that of the background. Table 1 shows the respective evaluation results that the glossiness of the highlight portion and the shadow portion can be visually observed and the glossiness of the recording surface is remarkably lower than that of the base.

  It can be seen that the ink set according to the present invention has good results in color bleed and beading as well as light source dependency and glossiness.

Claims (8)

An ink-jet ink comprising at least a colorant, water, and a polymer compound having a plurality of side chains in a hydrophilic main chain and capable of crosslinking between side chains by irradiation with active energy rays An ink jet ink set comprising two or more ink jet ink sets, wherein the ink jet ink set contains black ink and at least two types of gray inks having different black color material concentrations. The ink-jet ink set according to claim 1, wherein the ink-jet ink set comprises yellow ink, magenta ink, cyan ink, black ink, light gray ink, and gray ink. The inkjet ink set according to claim 1 or 2, wherein the black ink and the color material of at least two types of gray ink are carbon black. 4. The ink according to claim 1, wherein the ink containing the polymer compound contains 0.8 to 5.0 mass% of the polymer compound with respect to the total mass of the ink. Ink set for inkjet. The hydrophilic main chain is a saponified product of polyvinyl acetate, has a saponification degree of 77 to 99%, and a polymerization degree of 200 to 4000, according to any one of claims 1 to 4. Inkjet ink set. The inkjet ink set according to any one of claims 1 to 5, wherein a modification rate of the side chain with respect to the hydrophilic main chain is 0.8 mol% or more and 4 mol% or less. A water-soluble photopolymerization initiator is contained, The ink set for inkjets of any one of Claims 1-6 characterized by the above-mentioned. An ink jet recording method comprising: discharging the ink set for ink jet according to claim 1 onto a recording medium, irradiating the ink jet ink with active energy rays, and drying the ink set.