JP2001323193A - Inkjet ink and recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet ink and an ink-jet recording method which has good picture quality and can afford images of high quality with improved stability. SOLUTION: In the inkjet ink comprising a colorant in an aqueous medium, a water-soluble photocurable monomer and/or oligomer having a group capable of causing intermolecular cohesion and, simultaneously, an average molecular weight of 1,000-50,000 is incorporated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink used in an ink jet recording method, and more particularly to an ink jet recording method having improved image storability.

[0002]

2. Description of the Related Art An ink jet recording method for recording information by controlling and ejecting ink onto a recording material is described below.
Since the recording head is not brought into contact with the recording material, there are advantages such as no noise, high-speed recording, and recording on plain paper. The ink used in such an ink jet recording method includes, as basic components, various dyes or pigments and water or a water-soluble organic solvent that dissolves or disperses the dyes, and inks to which various additives are added as necessary. Known and used.

[0003] In recent years, the image quality of images obtained by ink-jet recording has been rapidly improving, and is approaching photographic image quality. In order to achieve such photographic image quality by ink jet recording, improvements are also being made in the surface of the recording paper, and a recording paper provided with a porous layer having minute voids on a highly smooth support has an ink absorbing property. And excellent drying properties,
It is becoming one of the recording papers from which images with the closest photographic quality can be obtained.

[0004] In ink jet recording, a water-soluble dye or pigment is usually used as a coloring material. Water-soluble dyes have high hue and saturation, and can produce beautiful images, but they have high hydrophilicity, so if they are stored for a long time under high humidity after recording, or if water droplets adhere to the recording surface, There was a drawback of bleeding. Further, on a recording medium having a porous layer, there is a defect that oxygen permeability is high due to the porous film due to the porous film, and the recording is easily discolored during storage in a room after recording.

When a pigment is used as a coloring material, defects such as bleeding and fading upon storage in a room are improved. However, because the particles are large, the resulting image has a rough feeling, lacks luster, and because the particles are large, the permeation into the porous layer is poor and the pigment remains on the surface, and disappears when erased with an eraser. There are drawbacks such as
The picture quality was far from good.

On the other hand, since photocurable monomers and oligomers can be cured in a very short time, inks using photocurable monomers and oligomers can give prints with little bleeding on plain paper. The technique is disclosed in JP-A-3-216379, JP-A-5-186725, JP-A-8-048922, and the like.

The inventors of the present invention have conducted intensive studies on ink-jet inks using the photocurable monomers / oligomers. As a result, by using photocurable monomers and oligomers having a group that causes intermolecular aggregation in the ink-jet ink, When a water-soluble dye is used in the ink, it prevents bleeding of an image formed on a recording medium, prevents light deterioration, can suppress fading during indoor storage, and also uses a pigment in the ink. Have found that not only the scratch resistance is improved, but also the roughness and gloss are dramatically improved.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and an object of the present invention is to provide a high-quality image with good image quality and improved storage stability. An object of the present invention is to provide an inkjet ink and an inkjet recording method.

[0009]

The objects of the present invention are as follows: (1) In an ink jet ink containing a colorant in an aqueous medium, the ink has a group capable of aggregating between molecules, and has a weight average molecular weight of 1,000. An inkjet ink comprising a water-soluble photocurable monomer and / or oligomer of not less than 50,000 and not more than 50,000. (2) The inkjet ink according to the above (1), wherein the group that aggregates between molecules is a group represented by the following formula. -(X) m- (C = O) -Y- (Formula) (wherein, X and Y represent an oxygen atom or a nitrogen atom;
Represents 0 or 1. (3) An image forming method, wherein the inkjet ink according to (1) is discharged onto a recording medium having a porous ink image receiving layer to form an image. Achieved by

Hereinafter, the present invention will be described in detail. First, the inkjet ink of the present invention will be described.
The group that agglomerates between molecules of a water-soluble photocurable monomer or oligomer used in an inkjet ink containing a colorant in an aqueous medium refers to a group that forms a hydrogen bond between molecules. It is preferable that two or more groups capable of aggregating between molecules are present in the water-soluble photocurable monomer or oligomer. The group that aggregates between the molecules is preferably
It is a group represented by the following formula (hereinafter, also referred to as “group of the present invention”). -(X) m- (C = O) -Y- (Formula) (wherein, X and Y represent an oxygen atom or a nitrogen atom;
Represents 0 or 1. )

The group that aggregates between molecules of the water-soluble photocurable monomer or oligomer of the present invention is preferably a urethane group or an ester group. The water-soluble photocurable monomer or oligomer used in the present invention has an average weight molecular weight of 1
It is necessary that the number be from 000 to 50,000. If the molecular weight is 1,000 or less, the image storability is not sufficient,
When the molecular weight is 50,000 or more, the viscosity becomes high and cannot be used as an ink. Here, the weight average molecular weight is a value calculated using GPC (gel permeation chromatography) in terms of polystyrene.

The water-soluble photocurable monomers and oligomers of the present invention have radically polymerizable groups such as ethylenically unsaturated groups and epoxy groups in order to impart photocurability. Specific examples of the water-soluble photocurable monomer and oligomer that can be used in the present invention include the following, but the weight average molecular weight is 1,000 or more and 50,000 or more.
The following water-soluble photocurable monomers and oligomers are not limited thereto.

(1) The weight average molecular weight is 1,000 or more and 50
Among the polyurethane oligomers having a (meth) acrylate group of not more than 000, the weight average molecular weight is not less than 1,000 and not more than 5
0000 (for example, UA-R manufactured by Kyoei Chemical Co., Ltd.)
1. UA-7200, UA-W2 manufactured by Shin-Nakamura Chemical
A) (2) Polyester oligomer having a (meth) acrylate group having a weight average molecular weight of 1,000 or more and 50,000 or less (for example, TO-1321 manufactured by Toa Gosei Chemical Co., Ltd .;
-1343)

In the ink-jet ink, the water-soluble photocurable monomer and oligomer of the present invention are preferably used in an amount of 0.1% by weight or more and 50% by weight or less based on the total weight of the ink. If the amount is less than 0.1% by weight, a sufficient effect cannot be obtained. If the amount exceeds 50% by weight, the viscosity of the ink becomes too high to form an image. More preferably, it is used in the range of 1% by weight to 20% by weight based on the total weight of the ink. In the present invention, a photopolymerization initiator can be used as necessary. In the present invention, a photopolymerization initiator is added to an ink-jet ink or a recording medium,
After the image is formed, it may be cured by light irradiation. A known photopolymerization initiator can be used as the photopolymerization initiator.

As the colorant of the present invention, known water-soluble dyes and pigments can be used. The water-soluble dyes that can be used are selected from water-soluble direct dyes, acid dyes, reactive dyes, and basic dyes, and these can be used alone or in combination of two or more. These dyes are appropriately selected as desired, and used after dissolving in a solvent.

<Direct Dye> C.I. I. Direct Yellow 1,4,8,11,1
2,24,26,27,28,33,39,44,5
0,58,85,86,100,110,120,13
2,142,144 C.I. I. Direct Red 1,2,4,9,11,1
3, 17, 20, 23, 24, 28, 31, 33, 3
7, 39, 44, 47, 48, 51, 62, 63, 7
5,79,80,81,83,89,90,94,9
5,99,220,224,227,243 C.I. I. Direct Blue 1,2,6,8,15,2
2,25,71,76,78,80,86,87,9
0,98,106,108,120,123,163,
165, 192, 193, 194, 195, 196, 1
99, 200, 201, 202, 203, 207, 23
6,237 C.I. I. Direct Black 2,3,7,17,1
9, 22, 32, 38, 51, 56, 62, 71, 7
4,75,77,105,108,112,117,1
54

<Acid dye> I. Acid yellow 2,3,7,17,19,
23, 25, 29, 38, 42, 49, 59, 61, 7
2,99 C.I. I. Acid Orange 56, 64 C.I. I. Acid red 1,8,14,18,26,
32, 37, 42, 52, 57, 72, 74, 80, 8
7, 115, 119, 131, 133, 134, 14
3,154,186,249,254,256 C.I. I. Acid Violet 11, 34, 75 C.I. I. Acid Blue 1,7,9,29,87,1
26,138,171,175,183,234,23
6,249 C.I. I. Acid Green 9,12,19,27,4
1 C. I. Acid black 1,2,7,24,26,
48, 52, 58, 60, 94, 107, 109, 11
0, 119, 131, 155

<Reactive dye> C.I. I. Reactive Yellow 1,2,3,13,1
4,15,17,37,42,76,95,168,1
75 C.I. I. Reactive Red 2,6,11,21,2
2,23,24,33,45,111,112,11
4,180,218,226,228,235 C.I. I. Reactive Blue 7,14,15,18,
19, 21, 25, 38, 49, 72, 77, 176
203, 220, 230, 235 C.I. I. Reactive Orange 5,12,13,3
5,95 C.I. I. Reactive Brown 7, 11, 33, 3
7, 46 C.I. I. Reactive Green 8,19 C.I. I. Reactive Violet 2,4,6,8,
21, 22, 25 C.I. I. Reactive Black 5,8,31,39

<Basic dye> C.I. I. Basic Yellow 11, 14, 21, 32 C.I. I. Basic Red 1,2,9,12,13 C.I. I. Basic violet 3, 7, 14 C.I. I. Basic Blue 3,9,24,25

Further, in the present invention, a water-soluble phthalocyanine dye can be used. The water-soluble phthalocyanine dye is a dye having a phthalocyanine skeleton and substituted and modified with a soluble group such as a sulfo group.
I. Direct Blue 199 and Direct B
lue 86 and the like. Further, as the dye that can be used in the present invention, in addition to the above, chelate dye,
An azo dye used in a so-called silver dye bleaching light-sensitive material (for example, Cibachrome manufactured by Ciba-Geigy) can be exemplified.

For the chelate dye, for example, the description in British Patent No. 1,077,484 can be referred to. Regarding the azo dyes used in the silver dye bleaching photosensitive material, for example, British Patent Nos. 1,039,458, 1,004,957, and 1,077
No. 7,628, U.S. Pat. No. 2,612,448 can be referred to.

As the pigment that can be used in the present invention, for example, conventionally known organic and inorganic pigments can be used as the pigment of the present invention. Examples thereof include azo lake pigments, insoluble azo pigments, condensed azo pigments, and chelate azo pigments. Pigments and other polycyclic pigments such as azo pigments, phthalocyanine pigments, perylene and perylene pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, thioindigo pigments, isoindolinone pigments, quinophthaloni pigments, basic dye lakes, and acid dye types Dye lakes such as lakes, nitro pigments,
Organic pigments such as nitroso pigments, aniline black and daylight fluorescent pigments, and inorganic pigments such as carbon black.
These pigments can be used alone or in combination. These pigments are appropriately selected as desired, and used by dispersing in a solvent.

Examples of the dispersant for dispersing the pigment used in the present invention include higher fatty acid salts, alkyl sulfates, alkyl ester sulfates, alkyl sulfonates, sulfosuccinates, naphthalene sulfonates, and alkyl phosphates. Salt, polyoxyalkylene alkyl ether phosphate,
Activator such as polyoxyalkylene alkylphenyl ether, polyoxyethylene polyoxypropylene glycol, glycerin ester, sorbitan ester, polyoxyethylene fatty acid amide, amine oxide, or styrene, styrene derivative, vinyl naphthalene derivative, acrylic acid, acrylic acid Block copolymers, random copolymers and salts thereof comprising two or more monomers selected from derivatives, maleic acid, maleic acid derivatives, itaconic acid, itaconic acid derivatives, fumaric acid, fumaric acid derivatives be able to. Examples of the dispersion method for dispersing the pigment include, for example, a ball mill, a sand mill, an attritor, a roll mill, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a pearl mill, a wet jet mill, a paint shaker, and the like. They can be used in appropriate combination. It is also preferable to use a centrifugal separator and a filter for the purpose of removing coarse particles from the pigment dispersion.

The aqueous medium used in the ink-jet ink of the present invention may contain a water-soluble organic solvent in addition to water. Examples of the water-soluble organic solvent that can be used include alkyl alcohols having 1 to 4 carbon atoms (for example, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol). -Butyl alcohol, isobutyl alcohol, etc.), amides (eg, dimethylformamide, dimethylacetamide, etc.), ketones or keto alcohols (eg, acetone, diacetone alcohol, etc.), ethers (eg, tetrahydrofuran, dioxane, etc.), poly Alkylene glycols (eg, polyethylene glycol,
Polypropylene glycol, etc.), having 2 to 6 alkylene groups.
Alkylene glycols containing carbon atoms (e.g.,
Ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol, diethylene glycol, etc.), glycerin, lower alkyl ethers of polyhydric alcohols (for example, ethylene glycol methyl Ether, diethylene glycol methyl (or ethyl) ether, triethylene glycol monomethyl (or ethyl) ether, and the like.

Among these many water-soluble organic solvents,
Polyhydric alcohols such as diethylene glycol and lower alkyl ethers of polyhydric alcohols such as triethylene glycol monomethyl (or ethyl) ether are preferred. The water-soluble organic solvent is generally used in a range of 10 to 70% by weight based on the total weight of the ink. In the inkjet ink of the present invention, a surfactant can be used in order to accelerate the penetration of the ink droplets after ejection into the recording material. The surfactant that can be used is not particularly limited as long as it has no adverse effect such as storage stability of the ink.

Further, an electric conductivity regulator can be used in the ink-jet ink of the present invention. As the electric conductivity regulator, for example, inorganic salts such as potassium chloride, ammonium chloride, sodium sulfate, sodium nitrate, and sodium chloride, and water-soluble amines such as triethanolamine can be used.

The ink-jet ink of the present invention has ejection stability, compatibility with print heads and ink cartridges,
Depending on the purpose of improving storage stability, image storability, and other various properties, a viscosity adjuster, a specific resistance adjuster, a film forming agent, an ultraviolet absorber, an antioxidant, a fading inhibitor, a rust inhibitor,
Preservatives and the like can also be added.

The ink of the present invention can be used for any on-demand or continuous ink jet recording system. As a discharge method, an electro-mechanical conversion method (for example, a single cavity type,
Double-cavity type, bender type, piston type, shared mode type, shared wall type, etc.), electro-thermal conversion method (eg, thermal inkjet type, bubble jet (registered trademark) type, etc.), electrostatic suction type (eg, Specific examples include an electric field control type, a slit jet type, and the like, and a discharge method (eg, a spark jet type).

The ink-jet ink of the present invention can be recorded on various recording media. Examples of the recording media include plain paper, coated paper, and a swelling type having an ink receiving layer which absorbs ink and swells. Examples of the recording paper include an inkjet recording paper and a void-type inkjet recording paper having a porous ink receiving layer. A recording medium using a resin film such as a polyethylene terephthalate film instead of the base paper can also be used. However, the inkjet ink of the present invention exhibits the best performance when recorded on a recording medium having a porous ink image-receiving layer, for example, a gap type inkjet recording paper or a gap type inkjet film.

[0030]

EXAMPLES The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to the embodiments. Example 1 (Preparation of cyan ink 11)
Cyan ink 11 having the composition shown in Table 1 was prepared through a 4 μm filter. Compound addition amount Photocurable oligomer (Aronix TO-1343) 100 g Photocuring initiator (Ciba Irgacure 2959) 3 g Dye (Direct Blue 199) 50 g Zeneca Proxel GXL (D) 1 g Ethylene glycol 150 g ion exchange water 696

(Preparation of Magenta Ink 11) Magenta ink 11 was prepared in the same manner as cyan ink 11 except that magenta dye (Direct Red 227) was used in place of Direct Blue 199 of cyan ink 11.
Was prepared. (Preparation of Yellow Ink 11) Di of Cyan Ink 11
A yellow ink 11 was prepared in the same manner as the cyan ink 11, except that a yellow dye (Acid Yellow 23) was used instead of the Rect Blue 199.

(Preparation of Cyan Ink 12) The following components were stirred and mixed, and a cyan ink 12 having a composition ratio shown in Table 1 was prepared through a 4 μm filter. Compound addition amount Photocurable oligomer (Aronix TO-1343) 100 g Dye (Direct Blue 199) 50 g Zeneca Proxel GXL (D) 1 g Ethylene glycol 150 g Ion-exchanged water 699 g

(Preparation of Magenta Ink 12) A magenta ink 12 was prepared in the same manner as the cyan ink 12 except that a magenta dye (Direct Red 227) was used instead of the Direct Blue 199 of the cyan ink 12.
Was prepared. (Preparation of Yellow Ink 12) Di of Cyan Ink 12
A yellow ink 12 was prepared in the same manner as the cyan ink 12 except that a yellow dye (Acid Yellow 23) was used in place of the Rect Blue 199.

(Preparation of Cyan Ink 13) The following components were mixed by stirring and passed through a 0.45 μm filter.
The cyan ink 13 having the composition ratio shown in the following was prepared. Compound addition amount Photocurable oligomer (UA-W2A) 50 g Dye (Direct Blue 199) 50 g Zeneca Proxel GXL (D) 1 g Ethylene glycol 100 g Ion-exchanged water 799 g

(Preparation of magenta ink 13) Magenta ink 13 was prepared in the same manner as cyan ink 13 except that magenta dye (Direct Red 227) was used instead of Direct Blue 199 of cyan ink 13.
Was prepared. (Preparation of Yellow Ink 13) Di of Cyan Ink 13
A yellow ink 13 was prepared in the same manner as the cyan ink 13 except that a yellow dye (Acid Yellow 23) was used in place of the Rect Blue 199.

(Preparation of Cyan Ink 14) The following components were mixed by stirring and passed through a 0.45 μm filter.
The cyan ink 14 having the composition ratio shown in the following was prepared. Compound addition amount Photocurable oligomer (A-400) 100 g Dye (Direct Blue 199) 50 g Zeneca Proxel GXL (D) 1 g Ethylene glycol 100 g Ion exchange water 749 g

(Preparation of Magenta Ink 14) The magenta ink 14 was prepared in the same manner as the cyan ink 14 except that the magenta dye (Direct Red 227) was used instead of the Direct Blue 199 of the cyan ink 14.
Was prepared. (Preparation of Yellow Ink 14) Di of Cyan Ink 14
A yellow ink 14 was prepared in the same manner as the cyan ink 14 except that a yellow dye (Acid Yellow 23) was used in place of the Rect Blue 199.

(Preparation of Cyan Ink 15) The following components were stirred and mixed, and a cyan ink 15 having a composition ratio shown in Table 1 was prepared through a 4 μm filter. Compound Addition amount Dye (Direct Blue 199) 50 g Zeneca Proxel GXL (D) 1 g Ethylene glycol 150 g Ion-exchanged water 799 g

(Preparation of magenta ink 15) The magenta ink 15 was prepared in the same manner as the cyan ink 15 except that the magenta dye (Direct Red 227) was used instead of the Direct Blue 199 of the cyan ink 15.
Was prepared. (Preparation of Yellow Ink 15) Di of Cyan Ink 15
A yellow ink 15 was prepared in the same manner as the cyan ink 15 except that a yellow dye (Acid Yellow 23) was used in place of the Rect Blue 199.

<Photocurable oligomer>UA-W2A; polyurethane oligomer, average molecular weight 1
0000 (manufactured by Shin-Nakamura Chemical Co., Ltd.) Aronix TO-1343; polyester oligomer, average molecular weight 2500 (manufactured by Toagosei Co., Ltd.) A-400; diacrylic ester of polyethylene glycol, average molecular weight 400 (manufactured by Shin-Nakamura Chemical Co., Ltd.) Co., Ltd.)

[0041]

[Table 1]

<< Formation of Image >> The prepared yellow, magenta, and cyan inks 11 to 15 were each ejected with the number of ejection nozzles = 64.
Nozzle diameter = 22 μm A color image was formed at 720 dpi on a recording medium shown in Table 2 by discharging with a piezo-type inkjet tester equipped with a head having a discharging frequency of 30 KHZ. << Evaluation of Image >><Bleeding> The obtained image was subjected to an environment of 50 ° C. and 60% RH.
After storing for a week, bleeding was calculated by the following formula, and bleeding was evaluated. Bleeding (%) = (Dot diameter of dot after storage / Dot diameter of dot before storage) × 100 <Indoor fading effect> The obtained image was left for one month in front of a blower, and the cyan density was measured. To determine the concentration residual ratio. Concentration residual rate (%) = (concentration after storage / concentration before storage) x
100 <Evaluation of Light Resistance> The obtained image was irradiated with light of 70,000 lux / hr for 5 days using a xenon fade meter, and then the density of the magenta portion was measured to evaluate the light resistance. Table 2 shows the obtained results.

[0043]

[Table 2]

<Recording Medium> Porous type; Konica inkjet paper Photo-like QP swelling type; Konica inkjet paper Photojet paper Plain paper; Konica Copy NR-A80 paper

From these results, it can be seen that the ink-jet ink of the present invention has less bleeding and improved image storability. Further, it can be seen that excellent effects are also obtained when a recording medium having a porous ink image receiving layer is used as a recording medium and an image is formed on the recording medium.

Example 2 (Preparation of Magenta Pigment Dispersion 1) I. Pigment Red 122 100 g Glycerin 100 g Deionized water 130 g was mixed, and 0.3 mm zirconia beads were mixed in a volume ratio of 6%.
A 0% -filled horizontal bead mill (Ashizawa Co., Ltd., System Zeta Mini) was used to disperse the magenta pigment dispersion 1
I got The average particle size of the particles of the obtained magenta pigment dispersion 1 was 65 nm.

<< Preparation of Magenta Ink 21 >> Magenta Pigment Dispersion 1 160 g Photocurable oligomer (TO-1343) 150 g Diethylene glycol 180 g Glycerin 80 g Perex OT-P (manufactured by Kao Corporation) 5 g Proxel GXL (manufactured by Zeneca) 2 g The above was made up to 1,000 g with ion-exchanged water, and passed twice through a 1-micron millipore filter to prepare ink 21.

<< Preparation of Magenta Ink 22 >> The photocurable monomer / oligomer of magenta ink 21 (TO-13)
It was prepared in exactly the same way except that UA-W2A was used instead of 43). << Preparation of Magenta Ink 23 >> A magenta ink 21 was prepared in exactly the same manner except that A-400 was used in place of the photocurable monomer / oligomer (TO-1343). << Preparation of Magenta Ink 24 >> The magenta ink 21 was prepared in exactly the same manner except that ethylene glycol was used in place of the photocurable monomer / oligomer (TO-1343).

<< Preparation of Evaluation Sample >> Magenta Ink 2
An on-demand inkjet printer with a maximum recording density of 720 × 720 dpi, equipped with a piezo-type head using Nos. 1 to 24, a nozzle hole diameter of 20 microns, a driving frequency of 12 kHz, a nozzle number of 128 per color, and a nozzle density of 180 dpi between the same colors. Then, a uniform image pattern giving a reflection density of 1.8 was recorded on the recording medium shown in Table 3.

<Evaluation of Roughness> The printed evaluation sample image was visually observed, and the roughness was evaluated on a five-point scale, with 5 having no roughness and 1 having roughness. <Evaluation of Scratch Property> An evaluation sample image was attached to a surface plate having flatness, and a plate (3 cm square) to which gauze for disinfection was applied was applied with a load of 2 kg on a surface in contact with the image, and mechanically evaluated for 1
X-Rite 938 (Nippon Lithographic Equipment Co., Ltd.) rubs the image surface by reciprocating 00 times and measures the reflection density of the image before and after rubbing (measurement at three points to obtain an average value);
And the residual ratio of the dye was determined by the following equation. Dye residual ratio (%) = (reflection density after rubbing / reflection density before rubbing) × 100 <Evaluation of glossiness>
60-degree mirror gloss meter True Gloss GM-26
The measurement was performed using PRO (manufactured by Murakami Color Research Laboratory), and the average value was obtained. Table 3 also shows the obtained results.

[0051]

[Table 3]

Example 3 (Preparation of Yellow Pigment Dispersion 1) Magenta Pigment Dispersion 1
In the preparation of C.I. I. Pigment Red 122 instead of C.I. I. Pigment Yellow 128 was used to prepare a yellow pigment dispersion 1 in the same manner. << Preparation of Yellow Ink 31 >> A yellow ink 31 was prepared in the same manner as the ink 21 except that the yellow pigment dispersion 1 was used instead of the magenta pigment dispersion 1 in the preparation of the ink 21 of Example 2.

(Preparation of Cyan Pigment Dispersion 1) In the preparation of magenta pigment dispersion 1, C.I. I. Pigment Red 122 instead of C.I. I. Pigment Blue 15: 3 was used, and a cyan pigment dispersion 1 was prepared in the same manner. << Preparation of Cyan Ink 32 >> A cyan ink 32 was prepared in the same manner as the ink 21 except that the cyan pigment dispersion 1 was used in place of the magenta pigment dispersion 1 in the preparation of the ink 21 of Example 2.

Using the three colors of the prepared yellow ink 31, cyan ink 32 and magenta ink 21 prepared in Example 2, color images Nos. 41 to 43 were prepared. , Abrasion and glossiness were evaluated. Similarly, an ink using the photocurable monomer / oligomer shown in Table 4 was prepared, and an image No. 4 was prepared.
4-49 were created. Table 4 shows the obtained results.

[0055]

[Table 4]

From these results, it can be seen that the ink-jet ink of the present invention has little roughness, provides excellent gloss, and can provide an image excellent in water resistance and scratch resistance.

[0057]

According to the ink-jet ink of the present invention, excellent image quality can be obtained, and a high-quality image with improved storability can be obtained.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C056 EA04 EA05 EA13 FC02 FC06 2H086 BA53 BA59 4J039 AD21 AE04 AE06 BA04 BC39 BC60 BE01 BE03 BE04 BE05 BE06 CA03 CA06 EA05 EA15 EA16 EA17 EA19 EA20 EA24 EA33 EA33

Claims (3)

[Claims] 1. An ink-jet ink containing a colorant in an aqueous medium, a water-soluble photocurable monomer having a group capable of aggregating between molecules and having a weight average molecular weight of 1,000 to 50,000, and / or An inkjet ink comprising an oligomer. 2. The ink-jet ink according to claim 1, wherein the group that aggregates between molecules is a group represented by the following formula. -(X) m- (C = O) -Y- (Formula) (wherein, X and Y represent an oxygen atom or a nitrogen atom;
Represents 0 or 1. ) 3. An inkjet ink according to claim 1, which is ejected onto a recording medium having a porous ink image receiving layer,
An image forming method comprising forming an image.