JP2007152658A - Inkjet recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording method which causes no beading, nor color blend, in relation to a medium having little or no ink absorbency, enables attainment of an image of a high image quality and improves in jetting properties. <P>SOLUTION: After ink for inkjet containing at least a coloring agent, water and a polymer compound having a plurality of side chains in a hydrophilic main chain and being capable of forming a crosslink between the side chains is made to impact a recording material, the crosslink is formed by irradiation with an active energy beam. In this inkjet recording method, the value obtained by dividing the illuminance (mW/cm<SP>2</SP>) of the active energy beam at an ink discharge part on an effective wavelength for forming the crosslink by the sensitivity (mJ/cm<SP>2</SP>) of the ink for inkjet, is 1.0×10<SP>-5</SP>to 1.0×10<SP>-1</SP>. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ink jet recording method, and more particularly to an ink jet recording method for recording an image using an active energy ray-curable ink.

  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, for example, 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 is disclosed (for example, see Patent Document 3). In addition, so-called non-aqueous inks containing a pigment as an essential component and tri- or higher functional polyacrylate as a polymerizable material and using a ketone or an alcohol as a main solvent have been proposed (for example, patents). Reference 4).

  Further, an ink using a water-based ultraviolet polymerization monomer has been proposed (see, for example, 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.
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

  An object of the present invention is an ink jet recording which has a low ink absorbability, and furthermore, no beading or color bleeding occurs on a medium having no ink absorbability, and a high quality image can be obtained, and the light output is improved. Is to provide a method.

  The above object of the present invention has been achieved by the following configurations 1 to 8.

1. After landing an ink-jet ink containing at least a colorant, water, and a polymer compound having a plurality of side chains in a hydrophilic main chain and capable of forming a cross-linked bond between the side chains on a recording material, In the inkjet recording method in which the cross-linking is formed by irradiating active energy rays,
The value obtained by dividing the illuminance (mW / cm ² ) of the active energy ray of the ink discharge portion at a wavelength effective for the formation of the cross-linked bond by the sensitivity (mJ / cm ² ) of the ink-jet ink is 1.0 × 10 ^{−. 5 to} 1.0 × 10 ⁻¹

2. The inkjet recording method according to claim 1, wherein the sensitivity of the inkjet ink (mJ / cm ²⁾ is characterized in that in the range of ^{0.1mJ / cm 2 ~200mJ / cm 2} .

3. The inkjet recording method according to the 1 or 2 illuminance of the ink discharge portion of the active energy ray (mW / cm ²⁾ is characterized in that in the range of ^{0.001mW / cm 2 ~1mW / cm 2} .

  4). 4. The inkjet recording method according to any one of 1 to 3, wherein the polymer compound is contained in an amount of 0.8% by mass to 5.0% by mass with respect to the total mass of the inkjet ink.

  5. The hydrophilic main chain is a saponified product of polyvinyl acetate, and the saponified product has a saponification degree of 77 mol% to 99 mol% and an average polymerization degree of 200 as defined in JIS K 6726-1994, respectively. The inkjet recording method according to any one of 1 to 4, wherein the inkjet recording method is.

  6). 6. The ink jet recording method according to any one of 1 to 5, wherein the modification rate of the side chain with respect to the hydrophilic main chain is 0.8 mol% to 4 mol%.

  7). 7. The inkjet recording method according to any one of 1 to 6, wherein the inkjet ink contains a water-soluble photopolymerization initiator.

  8). 8. The ink jet recording method according to any one of 1 to 7, wherein the active energy ray is ultraviolet light.

  According to the present invention, ink jet recording with less ink absorbability, and further, no beading or color bleeding on a medium with no ink absorbability, high image quality, and improved light emission. Could provide a way.

  In the ink jet recording method of the present invention, by using the configuration defined in any one of claims 1 to 8, beading or It was possible to provide an ink jet recording method in which color bleeding did not occur, an image with high image quality was obtained, and the light emission property was improved.

  Hereinafter, details of each component according to the present invention will be sequentially described.

  As a result of intensive studies on the above problems, the present inventor, as a first step, has a plurality of side chains in the hydrophilic main chain, and can be crosslinked between the side chains by irradiating active energy rays. The present inventors have found a clue to solve the above-mentioned problems by incorporating a high molecular compound into the ink.

  However, it has been found that when the ink is emitted from the inkjet head, there is a problem that it is difficult to stably eject the ink when the ink is re-emitted at an emission interval.

  It has also been found that the dots may not be emitted to a normal position, resulting in noise. In particular, in the case of high-definition characters, the problem that noise-like dots are formed around the characters is also highlighted.

<< Inkjet recording method (also referred to as image forming method) >>
The ink jet recording method (also referred to as image forming method) of the present invention will be described.

Based on the knowledge obtained in the first step, the present inventor has further intensively studied the above problems, and as a result, at least a colorant (also referred to as a colorant) as described in claim 1. Ink-jet ink containing water and a polymer compound having a plurality of side chains in the hydrophilic main chain and capable of forming a cross-linking bond between the side chains (the ink for ink-jet recording will be described in detail later) In the ink jet recording method in which the cross-linking bond is formed by irradiating active energy rays after landing on the recording material, the active energy ray of the ink discharge portion at a wavelength effective for the formation of the cross-linking bond. By adjusting the value obtained by dividing the illuminance (mW / cm ² ) by the sensitivity (mJ / cm ² ) of the inkjet ink to be 1.0 × 10 ^{−5 to} 1.0 × 10 ⁻¹ , Overcoming various problems It was found to be able to.

  In the inkjet recording method of the present invention, an inkjet ink (also referred to as an ink composition or the like) to be described later is ejected and drawn on a recording material by an inkjet recording method, and then the ink is cured by irradiation with an active energy ray such as ultraviolet rays. .

(Irradiation method)
Next, as an irradiation method, a basic irradiation method is disclosed in Japanese Patent Application Laid-Open No. 60-132767. According to this, the light source which is an irradiation means 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.

  For example, in US Pat. No. 6,145,795, as an irradiation method, a method using an optical fiber or a method of irradiating a recording unit with active energy rays by applying a collimated light source to a mirror surface provided on the side of the head unit is disclosed. ing. Any of these irradiation methods can be used in the inkjet recording method of the present invention.

(Active energy rays)
The active energy rays according to the present invention include, for example, 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 are widely used.

  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.

<Inkjet ink>
The ink-jet ink according to the present invention will be described.

The ink-jet ink according to the present invention is characterized by a low solid content of about 10% such as a coloring material and a curing component in the ink, and as described later, a high-quality image with high smoothness can be obtained. This is a major difference from the conventional technology. Therefore, since the ink of the present invention causes water to occupy a considerable portion of the ink, if the illuminance of the head portion is high when the ink is dried at the head portion, the concentrated ink gels due to active energy rays and the head portion There is a problem in that defects such as clogging are caused, and as a result, the light emission property is worsened. On the other hand, when the value obtained by dividing the illuminance of the ink discharge portion by the sensitivity of the ink is in the range of 1.0 × 10 ^{−5 to} 1.0 × 10 ⁻¹ , the ink in the image portion is gelled. In the head portion, gelation could be prevented from occurring.

(Ink sensitivity)
The sensitivity of the ink is preferably 0.1 mJ / cm ^{2 to} 200 mJ / cm ² . The image forming method of the present invention is particularly effective for ink having a sensitivity in this range. Further, the illuminance of the ink discharge portion is preferably 0.001 mJ / cm ^{2 to 1} mW / cm ² from the viewpoint of the stability of the emission property. In the present invention, “wavelength effective for ink curing” means the absorption wavelength of the photoinitiator and sensitizer contained in the ink, and by irradiating active energy rays within this wavelength, An ink curing reaction occurs.

(Illuminance of ink ejection part)
The “illuminance of the ink ejection part” means the illuminance in the vicinity of the meniscus from which ink is ejected in the recording head, and the active energy rays irradiated from the recording head and / or from the side of the recording head are the recording material or It is caused by reflection on the platen.

  “Ink sensitivity” means the exposure energy required to cure the ink. The criterion for “curing” is that the ink surface is not touched even if the ink surface is touched by hand. Refers to the level.

  In the present invention, the sensitivity of the ink includes the molecular weight of the crosslinkable polymer compound, the crosslinking group modification rate of the crosslinkable polymer compound, the type of the main chain of the crosslinkable polymer compound, the amount of the crosslinkable polymer compound added, and the initiator. It can be changed depending on the amount.

In the present invention, the ink itself after printing by containing in the ink a polymer compound having a plurality of side chains in the hydrophilic main chain and capable of crosslinking between the side chains by irradiating active energy rays. However, it is possible to suppress the occurrence of color mixing between different colors (color bleed) and mottle (beading) due to overflow of ink on the recording medium due to the curing reaction. 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.

  << Polymer compound >>: Crosslinks are formed between side chains by active energy rays.

  The polymer compound according to the present invention will be described.

  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.

(Saponification degree and average polymerization degree of hydrophilic main chain of polymer compound)
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 defined by JIS K 6726-1994 is 77 mol% to It is preferable that it is 99 mol% and average polymerization degree is 200-4000. Furthermore, the average degree of polymerization is more preferably in the range of 200 to 2000 from the viewpoint of handling.

(Modification rate of side chain to hydrophilic main chain of polymer compound)
The modification rate of the side chain with respect to the main chain is appropriately adjusted for crosslinkability between side chains (also called reactivity), and is preferably 0.3 mol% to 4 mol%, preferably 0.8 mol% to 4 mol%. More preferable from the viewpoint of reactivity.

  As the photodimerization-type modifying group, those in which a diazo group, a cinnamoyl group, a stilbazolium group, a stilquinolinium group or the like is introduced are preferable. For example, the photosensitivity described in JP-A-60-129742 Resin (composition) is mentioned.

  The photosensitive resin described in JP-A-60-129742 is preferably 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. 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. M represents an integer of 0-6. 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 cross-linking 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 polymer compound according to the present invention (also referred to as active energy ray-crosslinked resin), the main chain originally having a certain degree of polymerization is cross-linked through a cross-link between the side chains. The effect of increasing the molecular weight per photon is remarkably large for an active energy ray-curable resin that polymerizes via a simple chain reaction. 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.

  These photopolymerization initiators may be grafted to the side chain with respect to the hydrophilic main chain.

<< Coloring material (also called coloring agent, coloring agent, etc.) >>
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 inkjet 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 substituent, and is preferably a hydrogen atom or a phenylcarbonyl group. R ₂ may be different and represents a hydrogen atom or a substituent, preferably a hydrogen atom. R ₃ represents a hydrogen atom or a substituent, and preferably a hydrogen atom or an alkyl group.

R ₄ represents a hydrogen atom or a substituent, preferably a hydrogen atom or an aryloxy group. R ₅ may be different and represents a hydrogen atom or a 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 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. R _e may be different and represents a hydrogen atom or a substituent. q represents 1 or 2. p represents an integer of 1 to 4. However, q + p = 5. Z represents a substituent, and represents a carboxyl group, an alkylsulfonyl group, an arylsulfonyl 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, an amino group, a hydroxy group, an alkylamino group or an arylamino group, and among them, a halogen atom, a hydroxy group or an alkylamino group is preferable.

《Disperse dye》
The disperse dye used in the present invention will be described.

  As the disperse dye, various disperse dyes such as an azo disperse dye, a quinone disperse dye, an anthraquinone disperse dye, and a quinophthalone disperse dye 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 orange pigments or yellow pigments 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 green pigments or cyan pigments 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.

(Pigment dispersion method)
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% by mass to 10% by mass, and more preferably 0.3% by mass to 5% by mass. These water-soluble resins can be used in combination of two or more.

  The average particle diameter 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, from the viewpoint of improving the stability of the pigment dispersion and improving the storage stability of the resulting ink. It is preferably 10 nm or more and 200 nm or less, and more preferably 10 nm or more and 150 nm or less.

(Measurement of particle size of pigment dispersion)
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.

(Pigment dispersion method)
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.

(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": on paper, also referred to as recording material, 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, per 1m ² coating coated amount on one side 10g before and after the coated paper, the coating amount per 1m ² is one side 5g before and after of lightweight coated paper, Binurikoshi, mat coated paper matte finish, Darukoto paper of dull finish, and newsprint I can list them. 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 μm 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 ink jet 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 nm 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.

<Inkjet recording device>
The ink jet recording apparatus used in the present invention will be described with reference to the drawings as appropriate. In addition, the recording apparatus of drawing is only an example and is not this limitation.

  FIG. 1 is a front view showing an example of a configuration of a main part of an ink jet recording apparatus that can be used in the ink jet recording method of the present invention.

  The recording apparatus 1 includes a head carriage 2, a recording head 3, an irradiation unit 4, a platen unit 5, and the like. In the recording apparatus 1, the platen unit 5 is installed under the recording material P.

  The platen unit 5 has a function of absorbing active energy rays, and absorbs excess active energy rays that have passed through the recording material P. As a result, a high-definition image can be reproduced very stably.

  The recording material P is guided by the guide member 6 and moves from the near side to the far side in FIG. 1 by the operation of the conveying means (not shown). A head scanning unit (not shown) scans the recording head 3 held by the head carriage 2 by reciprocating the head carriage 2 in the Y direction in FIG.

  The head carriage 2 is installed on the upper side of the recording material P, and stores a plurality of recording heads 3 to be described later according to the number of colors used for image printing on the recording material P, with the discharge ports arranged on the lower side. The head carriage 2 is installed with respect to the main body of the recording apparatus 1 in such a manner that it can reciprocate in the Y direction in FIG. 1, and reciprocates in the Y direction in FIG. 1 by driving the head scanning means.

  In FIG. 1, the head carriage 2 is white (W), yellow (Y), magenta (M), cyan (C), black (K), light yellow (Ly), light magenta (Lm), and light cyan (Lc). Although the drawing is carried out assuming that the recording heads 3 of light black (Lk) and white (W) are accommodated, the number of colors of the recording heads 3 accommodated in the head carriage 2 is determined as appropriate. Is.

  The recording head 3 is configured so that the recording material P is ejected from the ejection port by the operation of ejection means (not shown) provided with a plurality of ink jet inks according to the present invention supplied by the ink supply means (not shown). Discharge toward The ink of the present invention ejected by the recording head 3 has a colorant, water, a plurality of side chains in a hydrophilic main chain, and can be cross-linked between the side chains by irradiating active energy rays. It contains a high molecular compound, and the ink gels when irradiated with active energy rays.

  During the scanning in which the recording head 3 moves from one end of the recording material P to the other end of the recording material P in the Y direction in FIG. 1 by driving the head scanning means, a certain area (landing possible area) in the recording material P Ink is ejected as ink droplets to land on the landable area.

  The above scanning is performed as many times as necessary, and after ink is ejected toward one landable area, the recording material P is appropriately moved from the front to the back in FIG. 1 by the conveying means, and scanning by the head scanning means is performed again. In the meantime, the recording head 3 discharges ink to the next landable area adjacent to the landable area in FIG.

  By repeating the above-described operation and ejecting ink from the recording head 3 in conjunction with the head scanning unit and the conveying unit, an image composed of an aggregate of ink droplets is formed on the recording material P.

  The irradiation means 4 irradiates active energy rays. In the present invention, ultraviolet rays are preferred as the active energy ray. In this case, the irradiation unit 4 includes an ultraviolet lamp that emits ultraviolet light in a specific wavelength region with stable exposure energy and a filter that transmits ultraviolet light of a specific wavelength. Here, as the ultraviolet lamp, a mercury lamp, a metal halide lamp, an excimer laser, an ultraviolet laser, a cold cathode tube, a black light, an LED (lighting diode), or the like is applicable.

  The irradiating means 4 has the same shape as the largest one that can be set by the recording apparatus (inkjet printer) 1 among the landable areas where the recording head 3 ejects ink by one scan driven by the head scanning means. It has a shape larger than the possible area.

  The irradiation means 4 is fixed on both sides of the head carriage 2 so as to be substantially parallel to the recording material P.

  As described above, as a means for adjusting the illuminance of the ink discharge portion, not only the entire recording head 3 is shielded, but in addition, the ink discharge of the recording head 3 is determined from the distance h1 between the irradiation means 4 and the recording material P. It is effective to increase the distance h2 between the portion 31 and the recording material P (h1 <h2), or to increase the distance d between the recording head 3 and the irradiation means 4 (d is increased). Further, it is more preferable to provide a bellows structure 7 between the recording head 3 and the irradiation means 4.

  Here, the wavelength of the ultraviolet rays irradiated by the irradiation means 4 can be changed as appropriate by replacing the ultraviolet lamp or filter provided in the irradiation means 4.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these. In the examples, “%” represents mass% unless otherwise specified.

Example 1
Polymer compounds 1 and 2 are synthesized as follows, ink preparation, ink sets 1 to 4 are prepared, and samples 1 to 6 shown in Tables 1 and 2 are manufactured using the ink sets. did.

<< 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 an average polymerization degree of 300 and a saponification degree of 88 mol%, analyzed using the method defined in JIS K 6726-1994, was dispersed in 225 g of ion-exchanged water, 4.5 g of phosphoric acid and p- (3-methacryloxy-2-hydroxypropyloxy) benzaldehyde obtained by the above reaction were added under the condition that the modification rate was 3 mol% with respect to the saponified polyvinyl acetate. 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. A 12% aqueous solution of polymer compound 1 was prepared by dilution.

<< Synthesis of Polymer Compound 2 >>
In the synthesis of polymer compound 1, a 10% aqueous solution of polymer compound 2 was prepared in the same manner as polymer compound 1 except that the polymerization degree of the polyvinyl acetate saponified product was changed to 1700.

<Preparation of ink>
(A) Preparation of pigment dispersion (Preparation of 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 10g
Jonkrill 61
(Acrylic styrene-based resin dispersant, manufactured by Johnson) 3g
Glycerin 15g
Ion exchange water 72g
(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
Subsequently, pigment-type ink sets 1 to 4 were produced.

<< Preparation of Ink Set 1 >>: Pigment Type Ink set 1 comprising yellow ink Y1, magenta ink M1, cyan ink C1 and black ink K1 was prepared as follows.

(Preparation of yellow ink Y1)
Yellow pigment dispersion 20 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 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 20 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 a black ink K1 was produced.

<< Preparation of ink set 2 >>
Ink set 2 composed of yellow ink Y2, magenta ink M2, cyan ink C2, and black ink K2 was produced as follows.

(Preparation of yellow ink Y2)
Yellow pigment dispersion 20 parts 10% aqueous solution of polymer compound 2 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 Y2 was produced.

(Preparation of magenta ink M2)
Magenta ink M2 was produced in the same manner as yellow ink Y2, except that the yellow pigment dispersion was changed to a magenta pigment dispersion in the production of yellow ink Y2.

(Preparation of cyan ink C2)
Cyan ink C2 was produced in the same manner as yellow ink Y2, except that the yellow pigment dispersion was changed to a cyan pigment dispersion in the production of yellow ink Y2.

(Preparation of black ink K2)
Black pigment dispersion 20 parts 10% aqueous solution of polymer compound 2 20 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 K2 was produced.

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

(Preparation of yellow ink Y3)
Yellow pigment dispersion 20 parts 12% aqueous solution of polymer compound 1 9 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 Y3 was produced.

(Preparation of magenta ink M3)
A magenta ink M3 was produced in the same manner as the yellow ink Y3 except that the yellow pigment dispersion was changed to a magenta pigment dispersion in the production of the yellow ink Y3.

(Preparation of cyan ink C3)
A cyan ink C3 was produced in the same manner as the yellow ink Y3 except that the yellow pigment dispersion was changed to a cyan pigment dispersion in the production of the yellow ink Y3.

(Preparation of black ink K3)
Black pigment dispersion 20 parts 12% aqueous solution of polymer compound 1 9 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 black ink K3 was produced.

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

(Preparation of yellow ink Y4)
C. I. Pigment Yellow 74 10 parts Azisper PB821 (manufactured by Ajinomoto Fine Techno) 3 parts Aronix M5700 (manufactured by Toagosei Co., Ltd.) 7 parts Ethylene oxide added 1,6 hexanediol acrylate 72 parts 3-methoxybutyl acrylate 8 parts Irgacure 369 (manufactured by Ciba Specialty Chemicals) 5 parts After mixing and stirring each of the above compositions, the resulting solution was filtered with a filter to prepare an active energy ray-curable yellow ink Y4.

(Preparation of magenta ink M4)
C. I. Pigment Red122 10 parts Ajisper PB821 (manufactured by Ajinomoto Fine Techno) 3 parts Aronix M5700 (manufactured by Toagosei Co., Ltd.) 7 parts Ethylene oxide added 1,6 hexanediol acrylate 72 parts 3-methoxybutyl acrylate 8 parts Irgacure 369 (manufactured by Ciba Specialty Chemicals) 5 parts After mixing and stirring each of the above compositions, the resulting solution was filtered with a filter to prepare an active energy ray-curable magenta ink M4.

(Preparation of cyan ink C4)
C. I. Pigment Blue 15: 3 10 parts Azisper PB821 (manufactured by Ajinomoto Fine Techno) 3 parts Aronix M5700 (manufactured by Toagosei Co., Ltd.) 7 parts Ethylene oxide added 1,6 hexanediol acrylate 72 parts 3-methoxybutyl acrylate 8 parts Irgacure 369 (Ciba Specialty Chemicals) 5 parts After mixing and stirring each of the above compositions, the resulting solution was filtered with a filter to prepare an active energy ray-curable cyan ink C4.

(Preparation of black ink K4)
Carbon black (manufactured by Mitsubishi Chemical Corporation, MA-7) 10 parts Azisper PB821 (manufactured by Ajinomoto Fine Techno) 3 parts Aronix M5700 (manufactured by Toagosei Co., Ltd.) 7 parts Ethylene oxide-added 1,6-hexanediol acrylate 72 parts 3-methoxybutyl acrylate 8 Part Irgacure 369 (manufactured by Ciba Specialty Chemicals) 5 parts After mixing and stirring each of the above compositions, the resulting solution was filtered with a filter to prepare an active energy ray-curable black ink K4.

<Inkjet recording method>
Image printing was performed by an ink jet recording apparatus having a function shown in FIG. 1 using a piezo ink jet nozzle. The ink supply system includes an ink tank, a supply pipe, a front chamber ink tank immediately before the head, a pipe with a filter, and a piezo head. The piezo head was driven and ejected so that 2 to 15 pl multi-size dots could be ejected at a resolution of 720 × 720 dpi (dpi represents 1 inch, that is, the number of dots per 2.54 cm). Irradiation conditions after landing were as shown below. Note that the illuminance of the ink ejection unit was adjusted by adjusting the distance (d) between the light source and the head, which is the irradiation means shown in FIG.

(Irradiation conditions)
(1) Irradiation light source: high-pressure mercury lamp; 80 W / cm (manufactured by Nippon Battery Co., Ltd .: HN-64NL)
(2) Irradiation timing: After landing, irradiation was performed 0.1 seconds later using the irradiation light source.

  (3) Irradiation method: Line light source irradiation was performed from both sides of the recording head.

  (4) Illuminance of the ink discharge portion and its peak wavelength: Irradiation was performed by changing the illuminance as shown in Table 1 at a peak wavelength of 365 nm. Illuminance was confirmed with an illuminometer.

  (5) Irradiation energy was irradiated as “ink sensitivity” in Table 1 at an exposure energy and a peak wavelength of 365 nm. The sensitivity of the ink is a value evaluated by the following method.

(Ink sensitivity (also called curing sensitivity))
Using an on-demand ink jet printer with a maximum recording density of 720 x 720 dpi, using a piezo-type head with 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 (OK Koji Fuji manufactured by Oji Paper) High pressure mercury lamps placed at both ends of the piezo-type head after 80 seconds of printing, each ink was continuously ejected and landed, 0.1 W after landing, 80 W / cm (manufactured by Nippon Battery Co., Ltd .: HN-64NL) ). Immediately thereafter, the image portion was touched with a finger to evaluate the state of hardness of the image surface, and the irradiation energy which was not sticky and had no problem as surface curing sensitivity was defined as ink sensitivity.

(Evaluation of beading resistance)
A 5 cm × 5 cm magenta solid was printed and visually observed on art paper (NK Art Kanfuji N, manufactured by Oji Paper) by the inkjet recording method, and beading resistance was evaluated according to the following criteria.

◎: 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)
A black fine line having a width of 200 μm was printed on art paper (NK Art Kanfuji N, manufactured by Oji Paper Co., Ltd.) by the ink jet recording method, and then visually observed, and bleed resistance was evaluated according to the following criteria.

◎: 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 image smoothness)
N3 “fruit basket”, a high-definition color digital standard image conforming to JIS X 9201-1995, is printed on art paper (NK Art Kanfuji N, manufactured by Oji Paper Co., Ltd.) by the above inkjet recording method, visually observed, and image smoothing is performed according to the following criteria. The feeling was evaluated.

A: There is almost no difference in smoothness between the recording surface and the background, and it is natural. ○: The smoothness of the recording surface and the background is slightly different, but an acceptable level. No: The surface of the recording surface is observed to be rough, and there is clearly no smoothness. XX: A large roughness is felt not only by visual inspection but also by palpation (Evaluation of satellite (spattering of ink))
Using the ink jet recording method, black 8-point characters were printed on high-quality paper (full color PPC paper type 6000 manufactured by Ricoh Co., Ltd.), and the state around the characters (ink jumping: satellite) was enlarged and evaluated.

○: No satellite generation △: Slight satellite generation is observed ×: Many satellites are conspicuous and have practical problems (evaluation of intermittent ejection performance)
By the above ink jet recording method, intermittent operation of continuous discharge for 10 seconds → pause for a fixed time → continuous discharge was performed. At this time, since whether or not the discharge direction is disturbed at the beginning after the discharge pause is determined by the length of the pause time, the stability of intermittent discharge is measured by changing the length of the discharge pause time stepwise. The evaluation was based on the following criteria. The evaluation was performed at an environmental temperature of 23 ° C. and a humidity of 55% RH.

5: Stable discharge even when paused for 31 to 45 seconds 4: Stable discharge even after 21 to 30 seconds pause 3: Stable discharge even after 11 to 20 seconds pause 2: 6 to 10 seconds pause However, stable ejection was performed for only 1 to 5 seconds or less. Tables 1 and 2 show the obtained results. Table 1 shows details of ink sets 1 to 4 used for sample preparation (types of color materials, characteristics of polymer compounds, etc.), and Table 2 shows images using ink sets 1 to 4. The description of the evaluation result of the formed samples 1-6 is shown.

  From Table 2, compared with the comparison, the sample of the present invention has high ink sensitivity and shows good results for all items such as color bleed, beading, image smoothness, satellite, and intermittent ejection. I understand that.

It is a front view which shows the structure of the principal part of the recording device used with the recording method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Recording device 2 Head carriage 3 Recording head 4 Irradiation means 5 Platen part 6 Guide member 7 Bellows structure P Recording material

Claims (8)

After landing an ink-jet ink containing at least a colorant, water, and a polymer compound having a plurality of side chains in a hydrophilic main chain and capable of forming a cross-linked bond between the side chains on a recording material, In the inkjet recording method in which the cross-linking is formed by irradiating active energy rays,
The value obtained by dividing the illuminance (mW / cm ² ) of the active energy ray of the ink discharge portion at a wavelength effective for the formation of the cross-linked bond by the sensitivity (mJ / cm ² ) of the ink-jet ink is 1.0 × 10 ^{−. 5 to} 1.0 × 10 ⁻¹ The inkjet recording method according to claim 1, wherein the sensitivity of the inkjet ink (mJ / cm ²⁾ is characterized in that in the range of ^{0.1mJ / cm 2 ~200mJ / cm 2} . The ink jet recording method according to claim 1 or 2 illuminance of the ink discharge portion of the active energy ray (mW / cm ²⁾ is characterized in that in the range of ^{0.001mW / cm 2 ~1mW / cm 2} . The inkjet recording method according to any one of claims 1 to 3, wherein the polymer compound is contained in an amount of 0.8% by mass to 5.0% by mass with respect to the total mass of the inkjet ink. The hydrophilic main chain is a saponified product of polyvinyl acetate, and the saponified product has a saponification degree of 77 mol% to 99 mol% and an average polymerization degree of 200 as defined in JIS K 6726-1994, respectively. The inkjet recording method according to any one of claims 1 to 4, wherein the inkjet recording method is. The inkjet recording method according to claim 1, wherein the modification rate of the side chain with respect to the hydrophilic main chain is 0.8 mol% to 4 mol%. The inkjet recording method according to claim 1, wherein the inkjet ink contains a water-soluble photopolymerization initiator. The ink jet recording method according to claim 1, wherein the active energy rays are ultraviolet rays.

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