JP3511043B2 - Ink composition, recording method and recorded matter - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink composition mainly used for ink jet printing, and more specifically, an ink composition having excellent ink ejection stability, no clogging and high printing quality. Regarding

[0002]

2. Description of the Related Art Conventionally, various ink compositions have been proposed for use in ink jet printing.

However, the conventionally proposed ink composition has a problem that the print quality may be deteriorated in the color bleeding. Therefore, as a technique for preventing bleeding, it has been proposed to mix various surfactants, but an ink composition containing a large amount of a surfactant effective for preventing bleeding is inferior in dissolution stability and has a solid content. Was clogged in the ink ejection portion of the printer, and there was a problem that ejection stability deteriorated due to clogging.

Therefore, an object of the present invention is to provide an ink composition which does not cause clogging, has excellent ejection stability, prevents bleeding, and has excellent printing quality.

[0005]

As a result of studies to solve the above problems, the present inventors have found that a compound having a specific structure is highly effective in preventing bleeding as a dispersant for an ink composition. I found that there is. Further, as a result of investigation, it was found that the compound having the specific structure can be contained in the ink composition in an amount such that a sufficient effect can be obtained, and the above-described object can be achieved by using the specific composition. Then, the present invention has been completed.

That is, the present invention contains a colorant, 2-pyrrolidone, a compound represented by the following chemical formula (I), a compound represented by the following chemical formula (II), and a butyl ether solvent, and the chemical formula (I The above object is achieved by providing an ink composition characterized in that the content of the compound represented by (1) is 1% by weight or more in the total amount.

[0007]

[Chemical 3]

[0008]

[Chemical 4]

The present invention also provides the ink composition, wherein the content of the compound represented by the chemical formula (I) is 1 to 3% by weight.

The present invention also provides the ink composition, wherein the content of the compound represented by the chemical formula (II) is 1% by weight or more.

The present invention also provides the ink composition, wherein the butyl ether solvent is triethylene glycol monobutyl ether or diethylene glycol monobutyl ether.

Further, in the present invention, the content of the colorant is
15% by weight or less based on the total amount of the ink composition,
It is intended to provide the ink composition, wherein the content of pyrrolidone is 2% by weight or more in the total amount of the ink composition, and the content of the butyl ether solvent is 4% by weight or more in the total amount of the ink composition.

The present invention further provides the above ink composition containing a polymer dispersant having a carboxyl group in the molecule.

The present invention further provides the above ink composition containing a humectant selected from the group consisting of glycerin, diethylene glycol and ethylene glycol.

The present invention also provides a recording method for forming a recorded matter by depositing the ink composition on a recording medium in a predetermined pattern.

The present invention also provides a recorded matter obtained by depositing the ink composition on a recording medium in a predetermined pattern.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The ink composition of the present invention will be described in more detail below. The present invention provides a colorant, 2-
Pyrrolidone, a compound represented by the following chemical formula (I) (hereinafter referred to as "compound (I)"), the following chemical formula (II)
A compound represented by (hereinafter referred to as "compound (II)"),
And a butyl ether solvent, and the compound (I)
Is contained in a specific content.

[0018]

[Chemical 5]

[0019]

[Chemical 6]

Here, n and m in the compound (II)
Is the number of moles of addition of oxyethylene group, n + m
= 10 is an arbitrary number.

When the compound (I) is used in the conventional ink composition, the compound (I) may not be sufficiently dissolved in the ink composition. Further, if the ink composition contains solids that cannot be completely dissolved, the solids will be clogged in the ink ejection portion of the printer, and clogging will adversely affect ejection stability. Therefore, the content of compound (I) is limited.

In the present invention, the compound (I) is contained in the ink composition in an amount such that a sufficient effect can be obtained by changing the composition of the conventional ink to the above specific composition. It has been made possible. The composition of the present invention can sufficiently dissolve the compound (I),
Further, since the compound (I) is contained in a predetermined amount, clogging does not occur, discharge stability is excellent, bleeding is prevented, and print quality is also excellent.

In more detail, pigments and dyes are used as the colorant used in the present invention.

Examples of the pigment include C.I. I. Pigment Blue 1, 2, 3, 15, 15: 3, 14:34, 15:
4, 16, 22 and 60, C.I. I. Cyan pigments such as Vat Blue 4 and 60; C.I. I. Pigment Red 5,
7, 12, 48 (Ca), 48 (Mn), 57 (C
a), 57: 1, 112, 122, 123, 168, 1
84, 202, 209 and C.I. I. Pigment Violet 19 and other magenta pigments; C.I. I. Pigment Yellow 1, 2, 3, 12, 13, 14c, 16, 17, 7
3,74,75,83,93,95,97,98,10
9,110,114,128,129,138,15
Yellow ink pigments such as 0, 151, 154, 155, 180, 185; No. 2300, No. 900, MCF88, N
o.33, No.40, No.45, No.52, MA7, MA8, MA100, N
2200B (Mitsubishi Chemical), Columbia Raven series, Cabot Monarch series, Degussa ColorBlack series, Printex series, Special
Black ink pigments such as carbon black of the Black series; C.I. I. Pigment Orange 36, 43 and other orange ink pigments; C.I. I. Pigment Green 7,
36 and the like green ink pigments and the like. Each of these pigments may be used alone or in combination of two or more.

The average particle size of the pigment used is from 0.01 to
It is preferably 0.2 μm.

As the dyes, CI direct black 17, 19, 62, 154; CI food black 2; CI reactive black 5; CI acid black 52; CI project fast black 2 and other black dyes, CI direct yellow 11 , 44, 8
6,142,330; CI Acid Yellow 3,38;
CI Basic Yellow 11,51; CI Disperse Yellow 3,5; Yellow dye such as CI Reactive Yellow 2, CI Direct Red 227,23; CI Acid Red 18,52; CI Basic Red 14,
39; magenta dye such as CI Disperse Red 60,
CI Direct Blue 15,199,168; CI Acid Blue 9,40,74; CI Basic Blue 4
1; cyan dyes such as CI Reactive Blue 15 and the like.

Examples of the butyl ether solvent include triethylene glycol monobutyl ether and diethylene glycol monobutyl ether, which may be used alone or in combination.

As the compound (I), Olfine S
TG (trade name, manufactured by Nisshin Chemical Co., Ltd.), Surfynol 104
Commercial products such as (trade name, manufactured by Air Products and Chemicals Inc.) can be used. The specific content of the compound (I) is 1% by weight or more, and preferably 1 to 3% by weight based on the total amount of the ink composition. When the commercial product used is a mixture or a diluted product, the content is the content of the compound (I) itself. If the content is less than 1% by weight, color bleeding may be defective in terms of print quality.

As the compound (II), Surfynol 400 series (trade name, Air Products and Chemica
Commercially available products such as Olfin E1010 (trade name, manufactured by Nisshin Chemical Co., Ltd.) and the like can be used. The content of the compound (II) is preferably 1% by weight or more in the total amount of the ink composition in order to effectively prevent the occurrence of bleeding and improve the print quality, and the content is 1 to 3% by weight. % Is more preferable. When the content of the compound (II) is less than 1% by weight, the dissolution stability of the compound (I) may be difficult. In the present invention, since the compound (II) has a function of promoting the dissolution of the compound (I) by further containing not only the compound (I) but also the compound (II) as a surfactant, It becomes possible to sufficiently dissolve in the ink composition, and therefore, clogging does not occur and excellent ejection stability is achieved,
Bleed is prevented and print quality is excellent.

The content of the colorant is 15% by weight or less in the total amount of the ink composition, the content of 2-pyrrolidone is 2% by weight or more in the total amount of the ink composition, and the butyl ether is The content of the system solvent is preferably 4% by weight or more in the total amount of the ink composition, and the content of the colorant is 2 to 10% by weight in the total amount of the ink composition.
The content of the 2-pyrrolidone is 4 to 6% by weight in the total amount of the ink composition, and the content of the butyl ether solvent is 4 to 10% by weight in the total amount of the ink composition. More preferable.

When the content of the coloring agent exceeds 15% by weight, there is a possibility that printing stability and clogging characteristics may be impaired. The content of the 2-pyrrolidone is less than 2% by weight, or the content of the butyl ether solvent is 4
If it is less than wt%, the compound (I) may not be dissolved, and problems may occur in printing stability and clogging characteristics.

Further, in the present invention, when a pigment is used as a colorant, a dispersant such as a polymer dispersant or a surfactant may be added. Examples of the polymer dispersant include natural polymers and synthetic polymers.

Specific examples of the natural polymer include proteins such as glue, gelatin, casein and albumin; natural gums such as gum arabic and tragacanth:
Glucosides such as saponins; alginic acid and alginic acid derivatives such as propylene glycol alginate, triethanolamine alginate, and ammonium alginate;

Specific examples of the synthetic polymer include polyvinyl alcohols, polyvinylpyrrolidones, polyacrylic acid, acrylic acid-acrylonitrile copolymers, potassium acrylate-acrylonitrile copolymers, vinyl acetate-acrylic acid esters. Acrylic resins such as copolymers, acrylic acid-acrylic acid ester copolymers: styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, styrene-methacrylic acid monoacrylic acid ester copolymers, styrene-α -Styrene-acrylic resin such as methyl styrene-acrylic acid copolymer, styrene-α-methylstyrene-acrylic acid monoacrylic acid ester copolymer: styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, Vinylnaphthalene-acrylic acid copolymer, vinylnaphtha Len-maleic acid copolymer, vinyl acetate-ethylene copolymer, vinyl acetate-fatty acid vinyl ethylene copolymer, vinyl acetate-maleic acid ester copolymer, vinyl acetate-crotonic acid copolymer, vinyl acetate-acrylic Examples thereof include vinyl acetate-based copolymers such as acid copolymers and salts thereof. Among these, a copolymer of a monomer having a hydrophobic group and a monomer having a hydrophilic group, and a polymer composed of a monomer having both a hydrophobic group and a hydrophilic group in the pre-structure are preferable. In the above, a polymer dispersant having a carboxyl group in the molecule such as an acrylic resin or a styrene-acrylic resin is particularly preferably used.

As the above-mentioned surfactant, those used in the ink composition of this type can be used without any particular limitation. For example, an anionic surfactant or a nonionic surfactant is used. It is preferably used.

Examples of the anionic surfactants include sodium dodecylbenzene sulfonate, sodium laurate, ammonium salts of polyoxyethylene alkylethyl sulfate, and the nonionic surfactants include oxyethylene. Examples thereof include alkylethyl, polyoxyethylene alkyl ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylphenylethyl, polyoxyethylene alkylamine, and polyoxyethylene alkylamide. These may be used alone or in combination of two or more.

The amount of the dispersant added is arbitrary, but is preferably 10 to 60 parts by weight with respect to 100 parts by weight of the pigment in the ink composition.

The ink composition of the present invention contains the above colorant,
It is dispersed in a mixed solvent containing the butyl ether solvent through the compounds (I) and (II),
At this time, in the mixed solvent, water, a water-soluble organic solvent, or the like is preferably used as the other solvent mixed with the butyl ether solvent. In the mixed solvent, the mixing ratio of the butyl ether solvent, the water and the water-soluble organic solvent is 2 to 15 parts by weight of the butyl ether solvent and 10 to 40 parts by weight of the water-soluble organic solvent with respect to 100 parts by weight of water. Is preferred.

The water-soluble organic solvent has a boiling point of 25.
Examples thereof include low boiling organic solvents having a temperature of 0 ° C. or lower and high boiling organic solvents having a boiling point of 250 ° C. or higher.

Preferred examples of the low boiling point organic solvent include methanol, ethanol, n-propyl alcohol, iso-propyl alcohol, n-butanol, sec-butanol, tert-butanol, iso-butanol, n-pentanol and the like. Can be mentioned. A monohydric alcohol is particularly preferable. These low boiling point organic solvents are preferable because they have the effect of shortening the drying time of the ink composition.

Preferred examples of the high boiling point organic solvent include ethylene glycol, diethylene glycol,
Polyethylene alcohols such as triethylene glycol, polyethylene glycol, polypropylene glycol, propylene glycol, butylene glycol, 1,2,6-hexanetriol, thioglycol, hexylene glycol, glycerin, trimethylolethane, trimethylolpropane, ethylene glycol. Alkyl ethers of polyhydric alcohols such as monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, urea, N-methyl-2-pyrrolidone, 1,3-dimethyl -2-Imidazolidinone, triethanolamine, etc. are mentioned.

The ink composition of the present invention preferably contains glycerin as a moisturizing agent. Addition of glycerin effectively prevents the ink composition from drying on the front surface of the nozzle of the recording head and prevents the nozzle from clogging. The addition amount of glycerin is preferably 5 to 30 parts by weight in 100 parts by weight of the ink composition. In addition, diethylene glycol, ethylene glycol, or the like can be used as the moisturizing agent.

It may also contain a tertiary amine or an alkali hydroxide. Examples of the tertiary amine include trimethylamine, triethylamine, triethanolamine, dimethylethanolamine, diethylethanolamine, triisopropenolamine and butylethanolamine. Examples of the alkali hydroxide include potassium hydroxide, sodium hydroxide, lithium hydroxide and the like.

It is also possible to include an inorganic oxide colloid (also called an inorganic oxide sol). As such an inorganic oxide colloid, it is possible to use a commercially available product.

Further, an alkylethyl derivative having 3 or more carbon atoms of the pre-polyhydric alcohol, a saccharide, and the like, if necessary,
It is also possible to add a pH adjusting agent, an antiseptic agent, an antifungal agent and the like.

The ink composition of the present invention is preferably used in the form of a dispersion mixture in which the colorant is dispersed in the mixed solvent through the compounds (I) and (II) and the dispersant. Be served. The method of dispersing and mixing in this manner is not particularly limited, and a known method can be appropriately used. Further, it is preferable to remove coarse particles and foreign matters by performing filtration after the dispersion.

The ink composition of the present invention can be particularly preferably used for ink jet recording,
Since it has high penetrability to paper as a recording medium, it has excellent bleed prevention performance and high print quality. Further, it is less likely to cause clogging and is excellent in ejection stability.

The recording method of the present invention is carried out by depositing the above-mentioned ink composition of the present invention on a recording medium in a predetermined pattern to form a recorded product.

The recording medium used at this time is as follows.
It may be either a material having an absorptivity with respect to the ink composition such as paper or a material having a substantially non-absorptivity with respect to the ink composition. In the present invention, since the inkjet recording method is preferably used, a plastic sheet based on polyethylene terephthalate, polycarbonate, polypropylene, polyethylene, polysulfone, ABS resin, polyvinyl chloride, etc .; brass, iron, aluminum, SUS, copper, etc. Recording medium in which the metal surface or non-metal substrate is subjected to metal coating treatment by a method such as vapor deposition; recording medium subjected to water repellent treatment using paper as a substrate;
A recording medium in which the fiber surface of a cloth or the like is not subjected to water repellent treatment or the like; a recording medium made of a so-called ceramic material obtained by firing an inorganic material at a high temperature can be mentioned.

Then, the ink composition is preferably deposited by an ink jet printing method. As a specific example of the inkjet printing method, a known method such as the method described in JP-A-7-125220 can be cited without any particular limitation.

The predetermined pattern is arbitrary,
Various patterns such as text data such as sentences and image data such as photographs and pictures are adopted without particular limitation. Next, a recording method will be described in which a tank containing a foam made of a porous member is filled with the ink composition and is discharged from the tank to a recording head to form a recorded material. FIG. 1 is a cross-sectional view showing the relationship between the tank and the recording head. A tank 7a is provided above the recording head 3a provided on the carriage 2 by a guide shaft 2a. A foam 6a made of a porous material such as polyurethane foam is stored inside the tank 7a.
The tank 7a is provided with a communication hole 9 that communicates with the outside in its lid 8, and a trapezoidal protrusion 10 that is in close contact with the foam 6a is formed on the bottom surface thereof. The ink composition chamber 11 and the blind plug 12 are directed downward from the center of the protrusion 10.
And are provided. By inserting the hollow needle 5 into the blind plug 12, the recording head 3a communicates with the ink composition chamber 11 via the filter chamber 4, so that the ink composition impregnated in the tank 7a is supplied to the recording head 3a. Communication hole 9
At least one of which is a non-breathable non-breathable sealing member 21
The product is sealed under reduced pressure until just before use. Then, it is opened immediately before use, and the tank 7a communicates with the outside through the vent hole 9a. A recording method using an ink pack may be used instead of using the ink cartridge provided with the tank containing the foam as described above. When an ink cartridge provided with a tank accommodating a foam is used, the surfactant is adsorbed on the foam. Therefore, it is preferable to preliminarily contain the surfactant in a larger amount than in the case of using the ink pack.

The recorded matter of the present invention is obtained by adhering the ink composition of the present invention to the recording medium in the predetermined pattern.

[0053]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Unless otherwise specified in the following examples,
"%" Indicates% by weight.

[Example 1] <Ink preparation method> Carbon black and a dispersant were mixed, and glass beads (diameter 1.7 mm, 1.5 times amount (weight) of the mixture) in a sand mill (Yasukawa Seisakusho). And dispersed for 2 hours. Then remove the glass beads,
Other components were added, the mixture was stirred at room temperature for 60 minutes, and filtered through a 5 μm membrane filter to obtain an inkjet recording ink having the following composition.

[0055]   <Composition>   Carbon black 5%   Dispersant (styrene-acrylic acid copolymer) 2%   Glycerin 15%   Diethylene glycol 10%   Triethylene glycol monobutyl ether 10%   2-pyrrolidone 10%   Compound (I) 1.5%   Compound (II) 2%   Water level

[Example 2] An ink composition was prepared in the same manner as in Example 1 except that the composition was changed as follows. <Composition> CI Pigment Yellow 7 45% Dispersant (styrene-acrylic acid copolymer) 1% Glycerin 15% Diethylene glycol 10% Triethylene glycol monobutyl ether 10% 2-Pyrrolidone 10% Compound (I) 2% Compound (II) 2% pure water remaining

Example 3 An ink composition was prepared in the same manner as in Example 1 except that the composition was changed as follows. <Composition> CI Direct Black 195% Glycerin 15% Ethylene glycol 10% Ditoethylene glycol monobutyl ether 5% 2-Pyrrolidone 5% Compound (I) 1% Compound (II) 1% Pure water remaining amount

Example 4 An ink composition was prepared in the same manner as in Example 1 except that the composition was changed as follows. <Composition> CI Direct Yellow 86 4% Glycerin 15% Ethylene glycol 10% Diethylene glycol monobutyl ether 10% 2-Pyrrolidone 10% Compound (I) 3% Compound (II) 2% Pure water Remaining amount [Example 5] Example 1 except that the composition of
An ink composition was prepared in the same manner as in. <Composition> CI Pigment Yellow 128 4% Dispersant (styrene acrylic acid copolymer) 1.5% Glycerin 10% Triethylene glycol monobutyl ether 5% 2-Pyrrolidone 4% Triethanolamine 0.5% EDTA 0.05% Surfynol 104 (Compound (I)) 1.5% Surfynol 465 (Compound (II)) 1.8% Pure water remaining amount

[Comparative Example 1] An ink composition was prepared in the same manner as in Example 1 except that the following composition was used. <Composition> Carbon black 5% Dispersant (styrene-acrylic acid copolymer) 2% Glycerin 15% Triethylene glycol monobutyl ether 10% Compound (I) 1% Pure water Remaining amount

[Comparative Example 2] An ink composition was prepared in the same manner as in Example 1 except that the following composition was used. <Composition> CI Pigment Yellow 7 45% Dispersant (styrene-acrylic acid copolymer) 1% Glycerin 15% 2-Pyrrolidone 10% Compound (I) 1% Pure water Remaining amount

Test Example 1 <Print Stability Evaluation> Inkjet printer (trade name "M
J-930C ", manufactured by Seiko Epson Co., Ltd.), the obtained ink composition is filled in an ink cartridge, and stored in an inkjet recording medium (Seiko Epson Co., Ltd., special glossy film) at room temperature for a long time. Printed continuously below. For each ink composition, the presence or absence of dot omission and ink scattering during printing was observed and evaluated according to the following criteria. The weight of the ejected ink per dot is 0.040 μg, and the resolution is 360 dpi.
The output was × 360 dpi (the same applies to Test Examples 2 and 3 below).

(Evaluation Criteria) A: After 48 hours, dot omission or ink scattering occurred less than 10 times. B: After 24 hours, dot omission or ink scattering occurred less than 10 times, but after 48 hours, dot omission or ink scattering occurred 10 times. C: After 24 hours, dot omission or ink scattering occurred 10 times, and after 48 hours, dot omission or ink scattering exceeded 10 times. D; After 24 hours, dot omission or ink scattering occurred more than 10 times.

Test Example 2 <Clogging Reliability> The printer was filled with the obtained ink composition and continuously recorded on an inkjet recording medium (exclusive gloss film manufactured by Seiko Epson Corporation) for 10 minutes. Printed alphanumeric characters. After that, the printer was stopped, and the printer was left for 2 weeks in an environment of a temperature of 40 ° C. and a humidity of 25% without a cap. After leaving, the alphanumeric characters were printed again, and the number of recovery operations required until the print quality equivalent to that before leaving was obtained was examined. The evaluation was performed according to the following criteria.

(Evaluation Criteria) A: Printing quality equivalent to the initial one was obtained by 0 to 2 times of returning operation. B: The print quality equivalent to that at the initial stage was obtained after 3 to 5 times of returning operation. C: The print quality equivalent to that at the initial stage was not obtained even after 6 or more returning operations.

[Test Example 3] <Presence or absence of bleed> Using the ink composition obtained, an ink jet printer (trade name “MJ-930C”, manufactured by Seiko Epson Corporation) was used to prepare the following combination 2
Make sure that the paper (brand name "Xerox4
No. 024 ”manufactured by Xerox). As a result, occurrence of bleeding between the colors was observed and evaluated according to the following evaluation criteria.

Combination: (1): Ink composition obtained in Example 1 and ink composition obtained in Example 2 (2): Ink composition obtained in Example 3 and obtained in Example 4 Ink Composition (3): Ink Composition Obtained in Comparative Example 1 and Ink Composition Obtained in Comparative Example 2

(Evaluation Criteria) There is no bleeding between the two A colors and the contour is clear. B Whisker-like bleeding occurs between the two colors and print quality is poor.

[Test Example 4] <Light resistance test> The ink composition thus obtained was filled in an exclusive ink cartridge thereof using an inkjet printer (trade name "MJ-930C", manufactured by Seiko Epson Corporation), Printed. The printing output was solid (100% duty). As the print medium, a dedicated glossy film (manufactured by Seiko Epson Corporation) was used. The light resistance of the obtained printed matter was evaluated under the following conditions. First, light irradiation was performed using a xenon weatherometer Ci35A (manufactured by ATLAS), and the printed matter was exposed at a black panel 63 ° C., a relative humidity of 50%, and a 340 nm ultraviolet light emissivity of 0.35 W / m ² . The irradiation conditions were 360 kJ / m ² (light irradiation for 284 hours under the above conditions) or 720 kJ / m ² (light irradiation for 568 hours under the above conditions). After the irradiation, the reflection density of each color component of the printed matter was measured using a spectrophotometer GRETAG SPM (manufactured by GRETAG). The conditions at that time are the light source D50,
Without a light source filter, the white standard was absolute white and the viewing angle was 2 °. The residual density ratio was evaluated according to the following criteria. (Evaluation Criteria) Evaluation A: More than 90% Evaluation B: 80% or more and less than 90% Evaluation C: Less than 80% The results obtained in each test example are shown in Table 1.

[0069]

[Table 1] As can be seen from Table 1, in Examples 1 to 4, Comparative Examples 1 to 2
It was superior in all respects in printing stability, clogging reliability, and bleeding prevention. In addition, C.I.
In Example 5 using I Pigment Yellow 128, the printing stability and clogging reliability were superior to those in Comparative Examples 1 and 2, and the light resistance was better than that in Examples 1 to 4 and Comparative Examples 1 and 2. Was excellent.

[0070]

The ink composition of the present invention does not cause clogging, has excellent ejection stability, prevents bleeding, and has excellent print quality.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a relationship between a tank and ink in a recording method of the present invention.

[Explanation of symbols]

6a ... Foam, 3a ... Recording head, 7a ... Tank

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) C09D 11/00-11/20

Claims (11)

(57) [Claims] 1. A colorant, 2-pyrrolidone, a compound represented by the following chemical formula (I), a compound represented by the following chemical formula (II), and a butyl ether solvent are contained and represented by the above chemical formula (I). An ink composition, wherein the content of the compound is 1% by weight or more based on the total amount. [Chemical 1] [Chemical 2] 2. The ink composition according to claim 1, wherein the content of the compound represented by the chemical formula (I) is 1 to 3% by weight. 3. The ink composition according to claim 1, wherein the content of the compound represented by the chemical formula (II) is 1% by weight or more. 4. The ink composition according to claim 1, wherein the butyl ether solvent is triethylene glycol monobutyl ether or diethylene glycol monobutyl ether. 5. The C.I. I. Pigment
The ink composition according to any one of claims 1 to 4, which is Yellow 128. 6. The content of the colorant is 15% by weight or less in the total amount of the ink composition, the content of the 2-pyrrolidone is 2% by weight or more in the total amount of the ink composition, and the butyl ether system is used. The ink composition according to claim 1, wherein the content of the solvent is 4% by weight or more based on the total amount of the ink composition. 7. The ink composition according to claim 1, further comprising a polymer dispersant having a carboxyl group in the molecule. 8. The ink composition according to claim 1, further comprising a humectant selected from the group consisting of glycerin, diethylene glycol and ethylene glycol. 9. A recording method for forming a recorded matter by depositing the ink composition according to claim 1 on a recording medium in a predetermined pattern. 10. A recording material is formed by filling the ink composition according to any one of claims 1 to 8 into a tank containing a foam made of a porous member inside and discharging the ink composition from the tank to a recording head. Recording method to do. 11. A recorded matter obtained by depositing the ink composition according to claim 1 on a recording medium in a predetermined pattern.