JP2003335986A - Ink composition for ink jet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink composition for ink jet recording having improved fixability to a recording material such as paper, gloss paper and OHP sheet abrasion resistance and recorded image density without deteriorating water resistance. <P>SOLUTION: The ink composition for ink jet at least contains water, a water- soluble organic solvent and a pigment. The composition further contains fine particles of a resin having a glass transition temperature of ≤70°C and a dye. The resin particle is polyester resin particle and/or polyurethane resin particle. The pigment is a self-dispersing pigment having a carboxylic acid and/or a sulfonic acid on the surface. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-based ink composition for use in ink jet recording in which ink is ejected and jetted by using mechanical or thermal energy to record on a recording material. The present invention relates to a method for improving the fixability and abrasion resistance to a recording material such as paper, glossy paper, and OHP sheet, and further improving the density of recorded matter without impairing water resistance.

[0002]

2. Description of the Related Art Ink jet recording is a method of forming an ink droplet by using a mechanical or thermal action, discharging and ejecting the ink droplet, and forming an image on a recording material such as paper.
Since this method does not include processes such as development and fixing, which are found in recording methods such as electrophotography, it is easy to downsize the apparatus and at the same time, it is possible to record images at high speed and with low noise. .

As conventional inks for ink jet recording, dye-based inks in which various water-soluble dyes are dissolved in water or a mixed liquid of water and an organic solvent have been used. However, the recorded images formed by the dye-based inks have had problems of fastness such as light resistance and water resistance.

In order to solve these problems, pigment-based inks in which a pigment is dispersed as a coloring material have been developed. However, in the case of dye-based ink, since the color develops when the dye is dyed on the recording material, the surface condition of the recording material has a small effect on the image density. Is aggregated on the surface of the recording material and is fixed to form a color, so that the surface condition of the recording material has a large influence on the image density.

Therefore, the pigment-based ink has a disadvantage that the image density is remarkably deteriorated and the image quality is impaired, depending on the type of recording material. Particularly, plain paper such as copy paper and bond paper is not uniform in the surface state of the paper unlike the ink-jet dedicated paper, so that the image density of the pigment-based ink is a problem.

In order to solve the problem that the density of these pigment inks is low, a technique of adding a dye having a high density has been proposed. For example, JP-A-4-57
Japanese Patent No. 861 describes an aqueous black ink containing carbon black and a dye. According to this ink,
It has the advantages that stable ejection can always be performed even when the driving conditions change and the recording medium is used for a long time, the recorded image is excellent in robustness, and the recorded image has a high density. However, in these improved methods, since a water-soluble dye is used, a completely water-resistant recorded material has not been obtained.

Further, when a pigment is used as a colorant, the fixing property to a recording material such as paper, glossy paper and OHP sheet is not sufficient, and the recording material becomes dirty when the recorded matter is rubbed with a finger, and a marker pen is used. When the recorded matter is marked with, there is a problem in finger touch and abrasion resistance that the recorded matter is easily separated from the surface of the recording material, such as the recording part is soiled. In order to solve these problems, for example, Japanese Patent Laid-Open No. 10-46081 proposes a water-based ink in which a pigment is dispersed and which contains a substantially colorless and transparent polyester suspension. The average image density is not obtained.

As described above, as a pigment-based ink using a pigment as a colorant, an ink sufficiently satisfying the characteristics of image density, water resistance and abrasion resistance has not been obtained yet.

[0009]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to improve the fixability and abrasion resistance to a recording material such as paper, glossy paper and OHP sheet, and further to record the recorded matter without impairing the water resistance. To provide an ink composition for inkjet recording having an improved concentration.

[0010]

The present invention provides an inkjet ink composition comprising at least water, a water-soluble organic solvent, and a pigment, the inkjet ink composition containing resin fine particles having a glass transition temperature of 70 ° C. or lower and a dye. It is a thing.

Although a method of adding a dye has been conventionally proposed as a method for improving the insufficient concentration of the pigment, the water resistance is impaired because the dye is water-soluble by simply adding the dye. Therefore, by adding resin fine particles having a glass transition temperature of 70 ° C. or lower, it is possible to improve the lack of pigment concentration without impairing water resistance even with a water-soluble dye. further,
By using these resin particles, paper, glossy paper and OHP
Even on a recording material such as a sheet, the pigment does not peel off and the fixability and abrasion resistance can be improved.

The present invention is also an ink composition for ink jet, wherein the resin fine particles are polyester resin particles and / or polyurethane resin particles.

When a polyester resin or a polyurethane resin is used for the resin fine particles, it is possible to improve the pigment concentration, water resistance and abrasion resistance.

The present invention is the ink composition for ink jet, wherein the pigment is a self-dispersion pigment having carboxylic acid and / or sulfonic acid on the surface.

Furthermore, the present invention provides glycerin, diethylene glycol, triethylene glycol, propylene glycol, thiodiglycol, polyethylene glycol,
2 pyrrolidone, N-methylpyrrolidone, 1,5-pentanediol, 1,4-butanediol, 1,3-propanediol,
An inkjet ink composition containing at least one organic solvent selected from the group consisting of triethylene glycol monobutyl ether and ethyl carbitol.

Discharge performance can be improved by containing the above organic solvent.

The present invention is also an ink jet ink composition containing at least one dye selected from a water-soluble dye such as a direct dye, an acid dye, a basic dye and a reactive dye.

In the present invention, the dye is added in an amount of 0.5 to 0.5.
The inkjet ink composition contains 2.5% of the ink composition.

Further, the present invention is an ink composition for ink jet, characterized in that the combination of the pigment and the dye of the color material constituting each color is not necessarily the same.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described.
The pigment that can be used in the inkjet ink composition according to the embodiment of the present invention is not particularly limited, but the pigments shown below are preferably used.

As the black pigment, carbon black conventionally used in ink jet ink compositions can be used. Specific examples include furnace black, lamp black, acetylene black and channel black.

Examples of blue pigments include C.I. I. Pigment Blue 1, 2, 15, 15: 1, 15: 2, 15: 3,
15: 4, 15: 6, 16, 17: 1, 56, 60 and 63.

Examples of red pigments include C.I. I. Pigment Red 1, 2, 3, 5, 7, 17, 22, 23, 31,
38, 48: 2 (Ba), 48: 2 (Ca), 48: 3
(Sr), 48: 4 (Mn), 49: 1, 52: 2, 5
3: 1, 57: 1, 60: 1, 63: 1, 63: 2, 6
4: 1, 81, 83, 88, 101, 104, 105,
106, 108, 112, 114, 122, 123, 1
46, 149, 166, 168, 170, 172, 17
7, 178, 179, 185, 190, 193, 209
And 219 and the like.

Examples of yellow pigments include C.I. I. Pigment Yellow 1, 3, 12, 13, 14, 17, 24, 3
4, 35, 37, 42, 53, 55, 74, 81, 8
3, 95, 97, 98, 100, 101, 104, 10
8, 109, 110, 117, 120, 128, 138
And 153 and the like.

In addition to the above pigments, for example, black organic pigments such as aniline black (CI Pigment Black 1), C.I. I. Pigment Orange 1, 2, 5,
7, 13, 14, 15, 16, 34, 36, 38, C.I.
I. Pigment Violet 1, 2, 19, 32, C.I.
I. Pigment Green 1, 4, 36 and C.I. I. Pigment Brown 3, 5, 25, 26 or the like can also be used.

Further, in the present invention, a pigment of which surface active groups are oxidized or subjected to other surface treatment and which requires no dispersant can be preferably used. Since the surface of the pigment that has been subjected to the above-mentioned treatment is rich in carboxyl groups and sulfonic acid groups, it can be self-dispersed in the ink without using a dispersant.

These self-dispersion pigments are prepared, for example, as follows. A pigment is added to a solvent and subjected to high speed shear dispersion with a high speed mixer or the like, or impact dispersion with a bead mill, a jet mill or the like to obtain a slurry pigment dispersion liquid. While slowly stirring the pigment dispersion, a treating agent such as fuming sulfuric acid, sulfuric acid, chlorosulfuric acid and fluorosulfuric acid is added, and the pigment dispersion is heat-treated at 60 to 200 ° C. to impart the dispersibility to the pigment surface. Introduce a group. After removing the solvent from the pigment dispersion liquid, the treatment agent is removed by repeating washing with water, ultrafiltration, reverse osmosis, centrifugation, filtration and the like to obtain a self-dispersion pigment.

The content of the pigment used in the ink jet pigment ink is determined in order to satisfy the desired color tone, density, or desirable physical properties of the printed matter, and depends on the specific gravity and bulk density of the pigment. Although not particularly limited, it is preferably from 1.0 to 20% by weight, more preferably from 1.0 to 15% by weight, based on the total weight of the ink composition. If the pigment content is less than 1.0% by weight, it may not be possible to secure the printing density, and if it exceeds 20% by weight, structural viscosity occurs in the viscosity characteristics of the ink composition, and ejection stability is ensured. May not be possible.

The dye that can be used in the ink composition for ink jet according to the embodiment of the present invention is not particularly limited, but a direct dye, an acid dye, a basic dye and a reactive dye are preferably used. It

Examples of the direct dye include C.I. I.
Direct Black 2, 4, 9, 11, 14, 17, 1
9, 22, 27, 32, 36, 41, 48, 51, 5
6, 62, 71, 74, 75, 77, 78, 80, 10
5, 106, 107, 108, 112, 113, 11
7, 132, 146, 154, 168, 171, 19
4, C.I. I. Direct Blue 1, 2, 6, 8, 12,
15, 22, 25, 34, 69, 70, 71, 72, 7
5, 76, 78, 80, 81, 82, 83, 86, 8
7, 90, 98, 106, 108, 110, 120, 1
23, 158, 163, 165, 192, 193, 19
4, 195, 196, 199, 200, 201, 20
2, 203, 207, 218, 236, 237, 23
9, 246, 258, 287, C.I. I. Direct Red 1, 2, 4, 8, 9, 11, 13, 15, 17, 2
0, 23, 24, 28, 31, 33, 37, 39, 4
4, 46, 47, 48, 51, 59, 62, 63, 7
3, 75, 77, 79, 80, 81, 83, 84, 8
5, 87, 89, 90, 94, 95, 99, 101, 1
08, 110, 145, 189, 197, 224, 22
5, 226, 227, 230, 250, 256, 25
7, C.I. I. Direct Yellow 1, 2, 4, 8, 1
1, 12, 24, 26, 27, 28, 33, 34, 3
9, 41, 42, 44, 48, 50, 51, 58, 7
2, 85, 86, 87, 88, 98, 100, 110,
127, 135, 141, 142, 144, C.I. I. Direct Violet 1, 7, 9, 12, 35, 48,
51, 90, 94, C.I. I. Direct Green 1,
6, 8, 28, 33, 37, 63, 64, C.I. I. Direct Orange 6, 8, 10, 26, 29, 39, 4
1, 49, 51, 62, 102, C.I. I. Direct Brown 1A, 2, 6, 25, 27, 44, 58, 95,
100, 101, 106, 112, 173, 194, 1
95, 209, 210, 211 and the like.

Examples of the acid dyes include C.I. I.
Acid Black 1, 2, 7, 16, 17, 24, 2
6, 28, 31, 41, 48, 52, 58, 60, 6
3, 94, 107, 109, 112, 118, 119,
121, 122, 131, 155, 156, C.I. I. Acid Blue 1, 7, 9, 15, 22, 23, 25, 2
7, 29, 40, 41, 43, 45, 51, 53, 5
5, 56, 59, 62, 78, 80, 81, 83, 9
0, 92, 93, 102, 104, 111, 113, 1
17, 120, 124, 126, 138, 145, 16
7, 171, 175, 183, 229, 234, 23
6, 249, C.I. I. Acid Red 1, 4, 6, 8,
13, 14, 15, 18, 19, 21, 26, 27, 3
0, 32, 34, 35, 37, 40, 42, 44, 5
1, 52, 54, 57, 80, 82, 83, 85, 8
7, 88, 89, 92, 94, 97, 106, 108,
110, 111, 114, 115, 119, 129, 1
31, 134, 135, 143, 144, 152, 15
4, 155, 172, 176, 180, 184, 18
6, 187, 249, 254, 256, 289, 31
7, 318, C.I. I. Acid Yellow 1, 3, 4,
7, 11, 12, 13, 14, 17, 18, 19, 2
3, 25, 29, 34, 36, 38, 40, 41, 4
2, 44, 49, 53, 55, 59, 61, 71, 7
2, 76, 78, 79, 99, 111, 114, 11
6, 122, 135, 142, 161, 172, C.I.
I. Acid Violet 7, 11, 15, 34, 3
5, 41, 43, 49, 51, 75, C.I. I. Acid Green 3, 9, 12, 16, 19, 20, 25, 2
7, 41, 44, C.I. I. Acid Orange 7, 8, 1
0, 19, 20, 24, 28, 33, 41, 45, 5
1, 56, 64, C.I. I. Acid Brown 4, 14 and the like can be mentioned.

Examples of the basic dye include C.I.
I. Basic Black 2, 8, C.I. I. Basic Blue 1, 3, 5, 7, 9, 24, 25, 26, 28, 2
9, C.I. I. Basic Red 1, 2, 9, 12, 1
3, 37, C.I. I. Basic Yellow 1, 2, 11,
14, 21, 32, 36, C.I. I. Basic Violet 1, 3, 7, 10, 14, C.I. I. Basic green 1, 4, C.I. I. Basic orange 2,15,2
1, 22, C.I. I. Basic brown 1, 12 and the like can be mentioned.

Examples of the reactive dye include C.I.
I. Reactive Black 1, 3, 5, 6, 8, 12,
14, 18, C.I. I. Reactive blue 2, 5, 7,
12, 13, 14, 15, 17, 18, 19, 20, 2
1, 25, 27, 28, 37, 38, 40, 41, 6
3, 80, 95, C.I. I. Reactive Red 6, 7,
11, 12, 15, 17, 21, 23, 24, 35, 3
6, 42, 63, 66, 84, 96, 97, 141, 1
47, 180, C.I. I. Reactive Yellow 1, 2,
3, 12, 13, 14, 15, 17, 22, 25, 4
2, 47, 51, 55, 65, 67, C.I. I. Reactive Violet 2, 4, 5, 8, 9, C.I. I. Reactive Green 5, 7, C.I. I. Reactive Orange 2, 5, 7, 16, 20, 24, C.I. I. Reactive Brown 1, 7, 16 and the like can be mentioned.

In addition to the above, C.I. I. Food Black 1, 2, C.I. I. Food blue 1, 2,
C. I. Hood Red 2, 3, 7, 9, 14, 52, 8
7, 92, 94, 102, 104, 105, 106,
C. I. Food Yellow 3, 4, 5, C.I. I. Food Violet 2, C.I. I. Food greens 2, 3 and the like can be mentioned.

Although the content of this dye is not limited, it is preferably in the range of 0.5% to 2.5%. If the content is less than 0.5%, it is difficult to obtain the required concentration, which is not preferable. Also, 2.5%
If it exceeds, the effect as a colorant is saturated and the water resistance is deteriorated, which is not preferable.

Here, the combination of the above-mentioned pigment and the above-mentioned dye of the color material constituting the ink does not necessarily have to be the same color. For example, a combination of black pigment and black dye is usually considered for black ink, but a combination of black pigment and cyan dye or magenta dye may be used.

The resin fine particles that can be used in the ink composition for ink jet according to the embodiment of the present invention are not particularly limited, but polyester resin fine particles and / or polyurethane resin fine particles are preferably used, and more preferable. Polyester resin fine particles are used.

The polyester fine particles of the present invention have a weight average molecular weight of 30,000 or less, a hydroxyl value of 13 or less, an acid value of 20 or less, and a particle diameter of 200 nm or less (preferably 50 nm or less). By containing the polyester fine particles, the ink composition can improve the water resistance after printing. Weight average molecular weight is 30,000
The following is preferable because the viscosity is low and the dispersed particle size can be easily controlled. If the glass transition temperature (Tg) of the polyester fine particles exceeds 70 ° C., the elongation at break (elongation at break) tends to be small and the abrasion resistance is deteriorated.
It is preferable that Tg is 70 ° C. or lower. When printing on a medium such as inkjet-dedicated paper having a coating layer such as glossy paper, the polyester resin fine particles having a low Tg tend to adhere to the medium, so that the Tg is 70.
C. or less is preferable. As such polyester resin fine particles, commercially available products satisfying the above conditions can be used, and examples thereof include Vylonal series manufactured by Toyobo Co., Ltd.

The aqueous medium used in the ink jet recording ink is mainly water, but it is preferable to use a water-soluble organic solvent added to water. Examples of the water-soluble organic solvent include methyl alcohol, ethyl alcohol,
n-propyl alcohol, isopropyl alcohol, n
-Butyl alcohol, sec-butyl alcohol, te
C1-C4 alkyl alcohols such as rt-butyl alcohol, amides such as dimethylformamide and dimethylacetamide, ketones or ketone alcohols such as acetone and diacetone alcohol, ethers such as tetrahydrofuran and dioxane, polyethylene glycol, Polyalkylene glycols such as polypropylene glycol, ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol, diethylene glycol and the like having 2 to 6 alkylene groups Alkylene glycols containing carbon atoms, glycerin, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol Lower alkyl ethers of polyhydric alcohols such as methyl ether, diethylene glycol ethyl ether, triethylene glycol monomethyl ether and triethylene glycol monoethyl ether, N-methyl-2-pyrrolidone, 2-pyrrolidone and 1,3-dimethyl- 2-imidazolidinone etc. are mentioned.

Among many of these water-soluble organic solvents,
Glycerin, diethylene glycol, triethylene glycol, propylene glycol, thiodiglycol, polyethylene glycol, 2 pyrrolidone, N-methylpyrrolidone, 1,5-pentanediol, 1,4-butanediol,
At least one water-soluble organic solvent selected from the group consisting of 1,3 propanediol, triethylene glycol monobutyl ether and ethyl carbitol is preferable. By blending these water-soluble organic solvents, the ejection performance can be improved.

The content of the water-soluble organic solvent in the ink jet recording ink is in the range of 5 to 50% by weight, preferably 5 to 40% by weight, more preferably 10 to 40% by weight based on the total weight of the ink. Is the range. By setting the content within the above range, it is possible to ensure the ejection stability of the pigment ink. When the content of the water-soluble organic solvent is too large, the blending ratio of water becomes low, and when printed, bleeding occurs on the medium or the drying property is significantly reduced, which is not preferable. On the other hand, if the content of the water-soluble organic solvent is too small, the moisture retention of the ink is insufficient and the solid content is dried and solidified at the nozzle, which is not preferable.

The ink jet recording ink is
In addition to the above components, a surfactant, an antifoaming agent, an antiseptic agent, etc. may be added in order to obtain a recording liquid having desired physical properties, if necessary. Further, urea, thiourea, ethylene urea or a derivative thereof may be added as an anti-drying agent for the nozzle.

Specific examples of the surfactant include higher fatty acid salts, alkylsulfates, and anionic surfactants.
Alkyl ether sulfate, alkyl ester sulfate, alkyl aryl ether sulfate, alkyl sulfonate, sulfosuccinate, alkyl allyl and alkyl naphthalene sulfonate, alkyl phosphate, polyoxyethylene alkyl ether phosphate and alkyl aryl There are ether phosphates.

Examples of the cationic surfactant include alkylamine salts, dialkylamine salts, tetraalkylammonium salts, benzalkonium salts, alkylpyridinium salts and imidazolinium salts.

Examples of the amphoteric surfactant include dimethylalkyllauryl betaine, alkylglycine, alkyldi (aminoethyl) glycine and imidazolinium betaine.

As the nonionic surfactant, polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene polyoxypropylene glycol, glycerin ester, sorbitan ester, sucrose ester, polyoxyethylene ether of glycerin ester, It is possible to use polyoxyethylene ether of sorbitan ester, polyoxyethylene ether of sorbitol ester, fatty acid alkanolamide, polyoxyethylene fatty acid amide, amine oxide and polyoxyethylene alkylamine.

Specific examples of the defoaming agent include ethyl alcohol and isopropyl alcohol.

Specific examples of antifungal, antiseptic and rust preventive agents include
Benzoic acid, dichlorophen, hexachlorophen, sorbic acid, p-hydroxybenzoic acid ester, ethylenediaminetetraacetic acid (EDTA), sodium dehydroacetate,
1,2-benzothiazolin-3-one, 3,4-isothiazolin-3-one and the like can be mentioned.

Although various physical properties of the ink jet recording ink can be controlled appropriately, according to a preferred embodiment of the present invention, the viscosity of the ink jet recording ink is 2
5 mPa · sec or less, preferably 15 mPa · sec or less (2
5 ° C). When the viscosity is within this range, the inkjet recording ink can be stably ejected from the ejection head. The surface tension of the ink jet recording ink can be appropriately controlled, but it is 20 to 60 mN /
It is preferably in the range of m (25 ° C.).

In the ink-jet ink composition according to the embodiment of the present invention, for example, a dye is added to water,
After stirring at room temperature to completely dissolve the dye, pigment dispersion, resin fine particles, organic solvent, and other additives are sequentially added, stirred at room temperature for 1 hour, and then filtered with a filter of a desired size. It is obtained by

The present invention will be specifically described based on Examples and Comparative Examples, but the present invention is not limited to the following Examples unless it exceeds the gist.

An ink jet ink composition was prepared according to the formulation shown in FIG. That is, after adding a dye to water and stirring at room temperature to completely dissolve the dye, a pigment dispersion, resin fine particles, an organic solvent, and other additives are sequentially added, and after stirring at room temperature for 1 hour, An inkjet ink composition was obtained by filtering with a 1.0 μm filter. The numerical values in FIG. 1 are parts by weight in all cases, and the total amount is 100.

Recording was carried out on the following medium for evaluation using the ink composition for ink jet obtained as described above. As the inkjet recording apparatus, a modified model of Sharp's inkjet printer AJ2000 was used.
The recorded image was evaluated by the following method. Figure 2 shows the evaluation results
Shown in.

(Evaluation 1) Image Density 2
A solid image of cm x 2 cm is formed on a sharp PPC paper, left for 1 hour, and the recording density at the center of the solid image is X-R.
It was measured with ite 938. Regarding black, those having a density of 1.20 or more are “◯”, and those having a density of 1.15 or more are 1.20 or more.
Those with less than 1. were evaluated as “Δ”, and those with less than 1.15 were evaluated as “x”. Regarding cyan, those having a density of 1.10 or more are “◯”, those having a density of 1.00 or more and less than 1.10 are “Δ”,
Those less than 1.00 were defined as “x”. Regarding magenta, those with a density of 1.00 or higher are marked with "○" and 0.90 with
Those having a value less than 1.00 are rated as “Δ” and those having a value less than 0.90 are designated as “x”. For yellow, the density is 0.7
Those having 5 or more were represented by “◯”, those having 0.70 or more and less than 0.75 were represented by “Δ”, and those having less than 0.70 were represented by “x”.

(Evaluation 2) The water resistance was adjusted to 2 by using the ink composition for inkjet recording prepared.
A solid image of cm × 2 cm was formed on a sharp PPC paper, allowed to stand for 24 hours, exposed to running water for 10 seconds, and dried at room temperature overnight. The state of the ink flowing out from the printed portion in the dried sample was evaluated according to the following 5 grades, and 4 or more were evaluated as “◯”, 3 as “Δ”, and 2 or less as “X”. 5: The printed part does not flow out 4: If you do not see the printed part carefully, you cannot know that the printed part is flowing out 3: The printed part slightly flows out 2: The printed part obviously flows out 1: Printing The color of the part flows out and the original color is discolored

(Evaluation 3) Abrasion resistance 2 was obtained by using the prepared ink composition for ink jet recording.
cm x 2 cm solid image for commercial inkjet O
Form on HP, leave for 1 hour, rub with fingers and eraser,
If the finger, the eraser, and the paper were not stained, the mark was “◯”, and if they were dirty, the mark was “x”.

(Evaluation 4) Marker resistance A character was printed on a sharp PPC paper using the prepared ink composition for ink jet recording, left for 1 hour, and then the character printed with a marker pen was rubbed. If there is bleeding, it is marked as “x”.

(Comprehensive Evaluation) In the above evaluations 1 to 4,
Those without "x" were evaluated as "○" for the overall evaluation, and "x" for other cases.

From the evaluation result of FIG. 2, the glass transition temperature was 7
It can be seen that the images formed by the inkjet ink compositions of Examples 1 to 7 containing the resin fine particles at 0 ° C. or less and the water-soluble dye are excellent in image density, water resistance, abrasion resistance and marker resistance. On the other hand, Comparative Examples 1 to 4 had one or more “x” in the evaluations 1 to 4 and were inferior as the inkjet ink composition.

[0060]

According to the present invention, paper, glossy paper and OHP
It is possible to provide an ink composition for inkjet which is capable of improving the fixability and abrasion resistance to a recording material such as a sheet and further improving the density of a recorded matter without impairing water resistance.

[Brief description of drawings]

FIG. 1 is a chart illustrating materials of ink compositions of Examples and Comparative Examples.

FIG. 2 is a chart illustrating the evaluation results of the ink compositions of Examples and Comparative Examples.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiromi Nakatsu             22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka             Inside the company (72) Inventor Kiyofumi Morimoto             22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka             Inside the company (72) Inventor Yoko Kageyama             22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka             Inside the company (72) Inventor Masaki Kinomoto             22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka             Inside the company F-term (reference) 2C056 EA13 FC01                 2H086 BA52 BA53 BA55 BA56 BA57                       BA58 BA59 BA60 BA62                 4J039 AE04 AE06 BC09 BC13 BC16                       BC50 BC54 BE01 BE02 CA06                       EA36 EA38 EA42 EA43 FA02                       GA24

Claims (7)

[Claims] 1. An inkjet ink composition comprising at least water, a water-soluble organic solvent and a pigment, which contains resin fine particles having a glass transition temperature of 70 ° C. or lower and a dye. 2. The inkjet ink composition according to claim 1, wherein the resin fine particles are polyester resin particles and / or polyurethane resin particles. 3. The ink composition for inkjet according to claim 1, wherein the pigment is a self-dispersion pigment having carboxylic acid and / or sulfonic acid on the surface. 4. Glycerin, diethylene glycol, triethylene glycol, propylene glycol, thiodiglycol, polyethylene glycol, 2 pyrrolidone,
The N-methylpyrrolidone, 1,5 pentane diol, 1,4 butane diol, 1,3 propane diol, triethylene glycol monobutyl ether and at least one organic solvent selected from the group of ethyl carbitol, as claimed in claim 1. The ink composition for inkjet according to any one of claims 1. 5. The ink-jet ink composition according to claim 1, wherein the dye contains at least one of a direct dye, an acid dye, a basic dye and a water-soluble dye such as a reactive dye. object. 6. The ink composition for inkjet according to claim 1, wherein the dye is contained in the range of 0.5 to 2.5%. 7. The ink composition for ink jet according to claim 1, wherein the combination of the pigment and the dye of the color material forming each color is not necessarily the same.