JP2002363450A - Aqueous ink composition - Google Patents

Abstract

(57) [Summary] [PROBLEMS] Discharge stability, print quality, fixability, paper compatibility
To provide a water-soluble ink composition which is excellent in point. SOLUTION: A coloring agent, water and hydrophobicity represented by the following formula (1) are provided.
And an acetylene alcohol compound of the following formula (2a):
Highly water-soluble acetylene glycol compounds and / or
Highly water-soluble acetylene alcohol compound of general formula (2b)
And one or more compounds selected from among
It is characterized by having. (1 formula: R₁ ~ R_Three Is H, an alkyl group or an alkyl group
Phenyl group, R₁+ R_Two+ R _Three≧ 5. 2a formula: R_Four ~
R₇ Is an alkyl group having 1 to 30 carbon atoms
Nyl group, R₁₁, R₁₂Is H or a methyl group, and n and m are 0
Integer of ~ 30. 2b: R₈ ~ R_TenIs H, an alkyl group,
R₁₃Is H or a methyl group, and l is an integer of 0 to 30. R₈
+ R₉+ R_Ten<5)

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, and more particularly to a quick-drying water-based ink composition suitable for an ink jet recording method.

[0002]

2. Description of the Related Art Conventionally, aqueous ink compositions generally include:
A surfactant is added for the purpose of (a) improving the printing quality (including paper compatibility), (b) improving the quick drying property, and (c) suppressing bleeding during adjacent multicolor printing. Since the surfactant used in the aqueous ink composition is required to have a high penetration promoting effect on the recording medium and structural characteristics that do not cause problems such as foaming during recording, a nonionic surfactant is used. Is often selected. In particular, acetylene alcohol compound-based and acetylene glycol-based surfactants,
Attention has been paid to the above requirements. Among them, acetylene alcohol compound surfactants are known to have an extremely high penetration promoting effect and to provide excellent printing quality even when added in a small amount (for example, see JP-A-63-13).
No. 9964, JP-A-4-239068, etc.).

[0003]

The acetylene alcohol compound-based surfactant having a structure having a higher hydrophobicity is more preferred because it has a higher penetration promoting effect, but has a lower solubility in water. It turned out that there is a case where attention must be paid to the clogging point.

Accordingly, the present inventors have conducted investigations and studies on the improvement of the solubility of an acetylene alcohol compound surfactant having a highly hydrophobic structure (sometimes simply referred to as “hydrophobic”) in water. However, the aqueous ink composition contains one or more compounds selected from a hydrophobic acetylene alcohol-based surfactant and a highly water-soluble acetylene glycol compound and / or a highly water-soluble acetylene alcohol compound. By using in combination with, it is possible to improve the water solubility of the hydrophobic acetylenic alcohol-based surfactant, so that there is no problem such as foaming, and the ejection stability and clogging point are reduced. In addition, the amount of hydrophobic acetylene alcohol-based surfactant added can be increased, so that In order to improve the permeability, to reduce the running cost, and to increase the permeability due to the effect of promoting the penetration of the highly water-soluble acetylene glycol compound and / or the highly water-soluble acetylene alcohol compound itself added as a solvent, It has been found that when a pigment is used as a coloring agent, excellent properties such as improved fixability (scratch resistance) are exhibited.

The present invention has been made on the basis of the above-mentioned findings, and aims at (a) improving ejection stability, (b) improving printing quality, and (c) fixing property ( (D) reduction of running cost,
(E) An object of the present invention is to provide an aqueous ink composition which is excellent in terms of paper compatibility, and to provide an ink cartridge containing the aqueous ink composition.

[0006]

According to the present invention, in order to achieve the above object, a hydrophobic acetylene alcohol compound, a highly water-soluble acetylene glycol compound and / or a water-soluble acetylene glycol compound are used as additives in an aqueous ink composition. It is used in combination with one or two or more compounds selected from acetylene alcohol compounds having high potency.

That is, the aqueous ink composition of the present invention comprises at least a colorant, water, at least one hydrophobic acetylene alcohol compound represented by the following general formula (1), and the following general formula (2a). And / or one or more compounds selected from highly water-soluble acetylene alcohol compounds represented by the general formula (2b). .

[0008]

Embedded image (In the formula 1, R ₁ , R ₂ and R ₃ each represent a hydrogen atom, an alkyl group or an alkylphenyl group which may have a branch, provided that R ₁ + R ₂ + R ₃ ≧ 5),

Embedded image (In the formula 2a, R ₄ , R ₅ , R ₆ , and R ₇ each represent an alkyl group having 1 to 30 carbon atoms or an alkylphenyl group which may have a branch, and R ₁₁ and R ₁₂ each represent Represents a hydrogen atom or a methyl group, and the subscripts n and m each represent an integer of 0 to 30. In the formula 2b, R ₈ and R
₉ and R ₁₀ each represent a hydrogen atom or an alkyl group which may have a branch, R ₁₃ represents a hydrogen atom or a methyl group, and the subscript 1 represents an integer of 0 to 30. However, R ₈
+ R ₉ + R ₁₀ <5)

Further, an ink cartridge according to the present invention is provided with an ink storage section for storing any one of the aqueous ink compositions described above.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, components used in the aqueous ink composition of the present invention will be described in detail.
In the present invention, "aqueous ink composition", for monochrome recording, means an aqueous black ink composition,
For color printing, it is intended to mean an aqueous color ink composition, specifically an aqueous yellow ink composition, an aqueous magenta ink composition, and an aqueous cyan ink composition, and in some cases, an aqueous black ink composition. .

A water-soluble compound can be further added to the aqueous ink composition of the present invention for the purpose of further improving recording stability such as writing characteristics and ejection characteristics. By adding an appropriate water-soluble compound, a writing instrument such as a pen may have smoother writing characteristics without blurring, and an inkjet recording may have more stable ejection characteristics. As such a water-soluble compound, an organic solvent or a water-soluble solid generally used in an aqueous ink composition can be used, and specifically, ethylene glycol,
Low molecular weight glycols such as diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol; 1,3-propanediol;
1,4-butanediol, 1,5-pentanediol,
Polyols such as 1,6-hexanediol, 1,2,6-hexanetriol, pentaerythritol and glycerin; lower alcohols such as ethanol and propanol; cellosolves such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether; diethylene glycol Carbitols such as monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether; 2-pyrrolidone;
Lactams such as N-methyl-2-pyrrolidone and ε-caprolactam; urea, thiourea, ethylene urea, 1,3-
Ureas such as dimethylimidazolidinones; sugars such as maltitol, sorbitol, gluconolactone, and maltose; The content of the aqueous compound is preferably 1 to 30% by weight, more preferably 5 to 25% by weight, based on the total weight of the aqueous ink composition. If it exceeds 30% by weight, it may be difficult to adjust the viscosity of the aqueous ink composition to a desired range, and the ejection stability may be deteriorated. If it is less than 1% by weight, the desired effect may not be obtained.

In the aqueous ink composition of the present invention, at least one of the hydrophobic acetylene alcohol compounds represented by the above general formula (1) and the above general formula (2)
a) combining a water-soluble acetylene glycol compound represented by a) and / or one or more compounds selected from highly water-soluble acetylene alcohol compounds represented by the general formula (2b); Is what you do. That is, in order to improve the print quality and the quick-drying property, and to improve the bleed deterrence during adjacent multicolor printing, the aqueous acetylene alcohol compound-based interface represented by the general formula (1) is added to the aqueous ink composition. When using activators,
And a water-soluble acetylene glycol compound represented by the general formula (2a) and / or the general formula (2b)
By using in combination with one or more compounds selected from among the highly water-soluble acetylene alcohol compounds represented by the formula, the solubility of the hydrophobic acetylene alcohol compound-based surfactant in water is increased, and the water solubility is high. Combined with the effect of promoting the penetration of the acetylene glycol compound and / or the highly water-soluble acetylene alcohol compound itself, the permeability of the aqueous ink composition to the recording medium is further increased, thereby improving the ejection stability, the print quality, It is also intended to obtain excellent effects in terms of improvement of fixing property (abrasion resistance), reduction of running cost, and improvement of paper compatibility. The solubility of the hydrophobic acetylene alcohol compound represented by the general formula (1) in water at 25 ° C. is 3.5% or less, and the highly water-soluble acetylene glycol compound represented by the general formula (2a) And / or the solubility of the highly water-soluble acetylene alcohol compound represented by the general formula (2b) in water at 25 ° C. is 3.5% or more.

As the acetylene alcohol compound represented by the above general formula (1), two or more compounds having different R ₁ , R ₂ and R ₃ can be used at the same time. The compounds shown in Table 1 below can be mentioned, but of course, the acetylene alcohol compound used in the present invention is not limited to them.

[0014]

[Table 1]

Among the acetylene alcohol compounds represented by the general formula (1), those having a structure having a strong hydrophobicity, that is, those having a larger total number of carbon atoms of R ₁ , R ₂ and R ₃ have a higher penetration promoting effect. Preferred. R ₁ , R ₂ , R _{3 of the} acetylene alcohol compound represented by the above general formula (1)
Is 5 or more, more preferably,
7 or more. And the total content of the acetylene alcohol compound represented by the above general formula (1) contained in the aqueous ink composition is 0.005 to 10% by weight, more preferably 0.01 to 5% by weight. . When the total content of the acetylene alcohol compound is less than 0.005% by weight, a desired penetration effect may not be easily exhibited.
When the content exceeds 10% by weight, it becomes difficult to adjust the viscosity of the aqueous ink composition to a desired range,
There are cases where inconveniences such as instability during ejection due to low water solubility become noticeable.

As the highly water-soluble acetylene glycol compound represented by the above general formula (2a), two or more compounds having different R _{4 to} R ₇ can be used at the same time. Examples include the compounds shown in Table 2, but of course, the compounds used in the present invention are not limited to these.

[0017]

[Table 2]

As the highly water-soluble acetylene alcohol compound represented by the above general formula (2b), two or more compounds having different R _{8 to} R ₁₀ can be used at the same time. 3, but the compounds used in the present invention are not limited thereto.

[0019]

[Table 3]

In addition, the water-soluble acetylene glycol compound represented by the general formula (2a) and / or the general formula (2b) used together to increase the solubility of the hydrophobic acetylene alcohol compound in water. The total content of one or more compounds selected from among the highly water-soluble acetylene alcohol compounds represented in the aqueous ink composition is 0.1 to 10% by weight, more preferably 0.2 to 5% by weight. % By weight. When the amount is less than 0.1% by weight, the desired effect, that is, the effect of sufficiently dissolving the required amount of the acetylene alcohol compound may not be easily exerted, and the ejection stability may be deteriorated. If it exceeds 10% by weight, problems such as difficulty in adjusting the viscosity of the aqueous ink composition to a desired range may occur.

The colorant used in the present invention may be any of a dye and a pigment. Pigments are preferred in terms of light resistance and water resistance. It is also possible to use a pigment and a dye together. When a pigment is used as a colorant, the effect of fixing property (abrasion resistance) by improving permeability is remarkable. The content of the colorant in the aqueous ink composition is preferably about 0.5 to 25% by weight, more preferably about 2 to 15% by weight.

The pigment used is not particularly limited, and may be either an inorganic pigment or an organic pigment. As the inorganic pigment, in addition to titanium oxide and iron oxide, carbon black produced by a known method such as a contact method, a furnace method, and a thermal method can be used. Examples of organic pigments include azo pigments (azo lake pigments, insoluble azo pigments, condensed azo pigments, chelated azo pigments, etc.), phthalocyanine pigments (copper phthalocyanine pigments, metal-free phthalocyanine pigments), condensed polycyclic pigments (anthraquinone pigments, perylene pigments) , Perinone pigments, quinacridone pigments, dioxazine pigments, thioindigo pigments, isoindolinone pigments, quinoflurone pigments, etc.),
Dye lakes (basic dye lakes, acid dye lakes, etc.), nitro pigments, nitroso pigments, aniline black and the like can be used. The particle size of the pigment is preferably 10 μm or less, more preferably 1 μm or less.

Particularly, carbon black used as black ink includes No. 2300, No. 900 and MCF8 manufactured by Mitsubishi Chemical Corporation.
8, No.33, No.40, No.45, No.52, MA7, MA8, MA100, No.2200B
Raven5750, Raven5250, Raven50 manufactured by Columbia
00, Raven3500, Raven1255, Raven700 etc. are Rega1 400R, Rega1 330R, Rega1 660R, Mogul L, Monar manufactured by Cabot.
ch 700, Monarch 800, Monarch 880, Monarch 900, Mon
arch 1OOO, Monarch 11OO, Monarch 1300, Monarch 14
00 etc. are Color Black FW1, ColorBlack manufactured by Degussa
FW2, Color Black FW2V, Color Black FW18, Color Bla
ck FW200, ColorB1ack S150, Color Black S160, Color
Black S170, Printex 35, Printex U, Printex V, Pri
ntex 140U, Special Black 6, Special Black 5, Speci
al Black 4A, Special Black 4, and the like.

Pigments used in the yellow ink include CI Pigment Yellow 1, CI Pigment Yellow 2, C.I.
I. Pigment Yellow 3, CI Pigment Yellow 12, CI Pig
ment Yellow 13, CIPigment Yellow 14C, CIPigmen
t Yellow 16, CI Pigment Yellow 17, CI Pigment Ye
llow 73, CI Pigment Yellow 74, CI Pigment Yellow
75, CI Pigment Yellow 83, CI Pigment Yellow 93,
CIPigment Yellow95, CIPigment Yellow97, CIPi
gment Yellow 98, CI Pigment Yellow 114, CI Pigmen
t Yellow128 、 CIPigment YelloW129 、 CIPigment Ye
llow151 and CI Pigment Yellow 154.

The pigments used in the magenta ink include CI Pigment Red 5, CI Pigment Red 7, CI
Pigment Red 12, CI Pigment Red 48 (Ca), CI Pigmen
t Red 48 (Mn), CI Pigment Red 57 (Ca), CI Pigment
Red 57: 1, CI Pigment Red 112, CI Pigment Red 12
3, CI Pigment Red 168, CI Pigment Red 184, CIP
igment Red 202 and the like.

As the pigment used in the cyan ink,
CIPigment Blue 1, CIPigmentBlue 2, CIPigment
Blue 3, CI Pigment Blue 15: 3, CI Pigment Blue 1
5:34, CI Pigment Blue 16, CI Pigment Blue 22, C.
I. Pigment Blue 60, CIVat Blue 4, CIVat Blue 60
Is mentioned.

In the present invention, at least one functional group such as a sulfone group, a carbonyl group, a carboxyl group, a hydroxyl group, an amino group or a salt thereof or a C1-C10 alkylene group or a phenylene group may be used on the surface thereof. By surface treatment such as bonding through such a bonding group,
What can be dispersed in water without a dispersant (surface-treated pigment) can also be used.

In the present invention, the pigment is preferably used as a pigment dispersion dispersed in an aqueous medium with a dispersant. As a dispersant used for preparing a pigment dispersion, a dispersant generally used for preparing a pigment dispersion, for example, a polymer dispersant or a surfactant can be used. It is clear that the surfactant contained in this pigment dispersion will also function as the surfactant of the aqueous ink composition. Preferred examples of the polymer dispersant include natural polymers, and specific examples thereof include proteins such as glue, gelatin, casein, and albumin; natural gums such as gum arabic and gum tragacanth; glucosides such as savonin; Alginic acid and alginic acid derivatives such as propylene glycol alginate, triethanolamine alginate and ammonium alginate; cellulose derivatives such as methylcellulose, carboxymethylcellulose, hydroxyethylcellulose and ethylhydroxycellulose. Further, preferred examples of the polymer dispersant include synthetic polymers, such as polyvinyl alcohols, polyvinylpyrrolidones, polyacrylic acid, acrylic acid-acrylonitrile copolymer, potassium acrylate-acrylonitrile copolymer, and vinyl acetate. -Acrylic resins such as acrylic ester copolymers and acrylic acid-acrylic ester copolymers; styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, and styrene-methacrylic acid-acrylic acid ester copolymers Styrene-acrylic resins such as styrene-α-methylstyrene-acrylic acid copolymer, styrene-α-methylstyrene-acrylic acid-acrylate copolymer; styrene-maleic acid copolymer, styrene-maleic anhydride Copolymer, vinyl naphthalene-acrylic acid copolymer Body, vinyl naphthalene
Maleic acid copolymer, vinyl acetate-ethylene copolymer, vinyl acetate-fatty acid vinyl ethylene copolymer, vinyl acetate-maleic acid ester copolymer, vinyl acetate-
And vinyl acetate-based copolymers such as crotonic acid copolymer and vinyl acetate-acrylic acid copolymer, and salts thereof. Among them, 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 a molecular structure are preferable.

The pigment dispersion used in the present invention is prepared, for example, by mixing a pigment and a dispersant with water or a mixture of water and a water-soluble organic solvent, and using a disperser (eg, bead mill, ball mill, sand mill, attritor). -, Roll mill, agitate
, A Henschel mixer, a colloid mill, an ultrasonic homogenizer, or a Parr mill).

In the present invention, a direct dye,
Various dyes usually used for ink jet recording, such as acid dyes, food dyes, basic dyes, photoreactive dyes, disperse dyes, vat dyes, soluble vat dyes, and reactive disperse dyes can be used.

[0031] The aqueous ink composition of the present invention may further contain a fixing agent, if necessary. As the fixing agent, water-soluble resins can be used, and water-soluble rosins, alginic acids, polyvinyl alcohol, hydroxypropyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose,
Styrene-acrylic acid resin, styrene-acrylic acid-acrylic acid ester resin, styrene-maleic acid resin, styrene-maleic acid half-ester resin, acrylic acid-acrylic acid ester resin, isobutylene-maleic acid resin,
Rosin-modified maleic resin, polyvinylpyrrolidone, gum arabic starch, polyallylamine, polyvinylamine, polyethyleneimine and the like can be mentioned.

The aqueous ink composition of the present invention may contain other additives, for example, a pH adjuster, a preservative and / or a fungicide. As the pH adjuster, for example,
Examples include various amines such as diethanolamine and triethanolamine, and hydroxides of alkali metals such as sodium hydroxide, potassium hydroxide, and lithium hydroxide.

The aqueous ink composition of the present invention contains 20
The surface tension at ° C is preferably from 20 to 55 mN / m, and more preferably from 25 to 45 mN / m. If it is less than 20 mN / m, a phenomenon that the aqueous ink composition wets the vicinity of the ejection nozzle unevenly may occur, and the ejection stability may be deteriorated. If it exceeds 55 mN / m, the desired permeation effect may not be easily exhibited. Further, the aqueous ink composition of the present invention is preferably used as an ink for inkjet recording.

[0034]

Next, examples of the present invention will be described together with comparative examples.
The present invention will be specifically described, but the present invention is not limited by the following examples.

Examples 1 to 6 and Comparative Examples 1 to 5 (Preparation of aqueous ink composition) 5 g of glycerin, 5 g of diethylene glycol and the additives shown in Examples 1 to 6 and Comparative Examples 1 to 5 in Table 4 were used, respectively. After mixing, ultrapure water was added to make the total amount 100 g. Next, triethanolamine was added to the mixture to adjust the pH to 7.5, and then 25
Stirred at C for 2 hours. After that, using a membrane filter having a diameter of 5 μm, pressure filtration was performed at a pressure of ² kg / cm ² ,
Each aqueous ink composition was obtained. However, the amount of the coloring agent added in Table 4 is a solid content conversion.

[0036]

[Table 4]

Evaluation Test <Evaluation of Discharge Stability> Examples 1 to 6 and Comparative Examples 1 to 5
Was charged into MJ-930C (Seiko Epson Corporation), which is a piezoelectric element type ink jet recording apparatus, and the ejection stability was evaluated by the following method. That is, first, MJ-930C filled with each aqueous ink composition
To perform continuous printing for 20 minutes to check whether the ejection is normal. Next, with respect to the aqueous ink composition from which normal ejection was obtained, a non-printing time of 1 minute is provided immediately after the printing in a state where the head carriage portion is separated from the cap portion, and printing is performed again immediately thereafter. Depending on the state of ejection in both continuous printing and printing after non-printing time,
Discharge stability is determined according to the following classification. The evaluation results are shown in Table 5 below. Judgment A: Normal ejection is performed in both continuous printing and printing after the non-printing time. Judgment B: The ejection in continuous printing is normal, but the ejection is slightly unstable in printing after the non-printing time. Judgment C: The ejection of the continuous printing is normal, but the ejection is unstable in the printing after the non-printing time. Judgment NG: The ejection is unstable in both continuous printing and printing after the non-printing time.

As is clear from Table 5 below, the present invention was compared with the aqueous ink compositions of Comparative Examples 4 and 5 which did not contain a highly water-soluble acetylene glycol compound and / or a highly water-soluble acetylene alcohol compound. The water-based ink composition of Example 1 provides good ejection stability. That is,
An aqueous ink composition comprising a hydrophobic acetylene alcohol compound and a water-soluble acetylene glycol compound and / or a water-soluble acetylene alcohol compound in combination has excellent ejection stability. In addition, even when it contains a highly water-soluble acetylene glycol compound and / or a highly water-soluble acetylene alcohol compound, the addition amount of the hydrophobic acetylene alcohol compound is 10% by weight as in the aqueous ink composition of Comparative Example 3. %, The ejection becomes unstable.

<Evaluation of Print Quality> The aqueous ink compositions of the above Examples 1 to 6 and Comparative Examples 1 to 5 were filled in MJ-930C, which is the above-mentioned ink jet recording apparatus, and 10-point characters were printed on plain paper and recycled paper. Was printed. However, with respect to the aqueous ink compositions of Comparative Examples 3 to 5, the ejection stability was poor, and a recorded matter could not be obtained. The plain paper and recycled paper used in this evaluation were Xerox-P and Xerox-4024 (both trade names: Fuji Xerox Co., Ltd.) as neutral plain paper, and E as acidic plain paper.
PP (trade name: manufactured by Seiko Epson Corporation); Xerox-R (trade name: manufactured by Fuji Xerox Co., Ltd.) as recycled paper; Yamauri (trade name: manufactured by Honshu Paper Co., Ltd.)
Kind. The printed characters were visually evaluated, and the print quality was evaluated according to the following criteria. The evaluation results are shown in Table 5 below. Judgment A: Good printing quality is shown on all evaluated papers. Judgment B: Of the evaluated papers, only two or less types of papers show a decrease in print quality. Judgment C: In three or more types of paper among the evaluated papers,
A decrease in print quality is observed. Judgment NG: In all the evaluated papers, a decrease in print quality is recognized.

As is clear from Table 5 below, the aqueous ink compositions of Examples of the present invention give good print quality with respect to the aqueous ink compositions of Comparative Examples 1 and 2 containing no acetylene alcohol compound. That is, the aqueous ink composition containing the acetylene alcohol compound has excellent printing quality.

<Evaluation of Fixing Property> The aqueous ink compositions of Examples 1 to 6 and Comparative Examples 1 to 5 were charged into MJ-930C, which is the above-mentioned ink jet recording apparatus, and 10-point characters were placed on plain paper and recycled paper. Was evaluated for fixability (abrasion resistance) by the following method. That is, the recorded matter is stored at a temperature of 25 ° C. and a relative humidity of 40.
After placing in an environment of% RH, immediately after printing and after standing overnight, a sheet of the same type as the recording paper is rubbed with a pressure of 300 g / cm ² from above. The state after the rubbing was visually observed and determined according to the following criteria. The obtained results are shown in Table 4 below. Judgment A: Smear due to rubbing does not occur immediately after printing and after leaving overnight. Judgment B: Smearing due to rubbing occurs only immediately after printing. Judgment C: Both immediately after printing and after standing overnight, stains due to rubbing occur. Judgment NG: Immediately after printing and after standing overnight, stains due to rubbing occur, and particularly, immediately after printing, significant stains occur.

As is clear from Table 5 below, the aqueous ink composition of Example of the present invention was compared with the aqueous ink composition of Comparative Example 2 using a pigment as a coloring agent and containing no hydrophobic acetylene alcohol compound. The article gives good fixability.

[0043]

[Table 5]

[0044]

According to the present invention, as described in detail above, at least one of the acetylene alcohol compounds represented by the general formula (1) is added to a water-soluble ink composition as an additive.
Combined use with one or more compounds selected from the highly water-soluble acetylene glycol compounds represented by the general formula (2a) and / or the highly water-soluble acetylene alcohol compounds represented by the general formula (2b) As a result, excellent effects are achieved in terms of ejection stability, printing quality, fixability, and paper compatibility.

Claims (6)

[Claims] 1. A water-soluble acetylene glycol compound represented by the following general formula (2a) and at least one of a hydrophobic acetylene alcohol compound represented by the following general formula (1) and water: And / or one or more compounds selected from highly water-soluble acetylene alcohol compounds represented by the general formula (2b). Embedded image (In the formula, R ₁ , R ₂ , and R ₃ each represent a hydrogen atom, an alkyl group which may have a branch, or an alkylphenyl group, provided that R ₁ + R ₂ + R ₃ ≧ 5.) ] (In the formula 2a, R ₄ , R ₅ , R ₆ , and R ₇ each represent an alkyl group having 1 to 30 carbon atoms or an alkylphenyl group which may have a branch, and R ₁₁ and R ₁₂ each represent Represents a hydrogen atom or a methyl group, and the subscripts n and m each represent an integer of 0 to 30. In the formula 2b, R ₈ and R
₉ and R ₁₀ each represent a hydrogen atom or an alkyl group which may have a branch, R ₁₃ represents a hydrogen atom or a methyl group, and the subscript 1 represents an integer of 0 to 30. However, R ₈
+ R ₉ + R ₁₀ <5) 2. The total content of the acetylene alcohol compound represented by the general formula (1) is 0.01 to 5% by weight based on the total weight of the aqueous ink composition. The total content of one or more compounds selected from the acetylene glycol compound represented by the formula (1) and / or the acetylene alcohol compound represented by the general formula (2b) is 0.1 to the total weight of the aqueous ink composition. ~
The aqueous ink composition according to claim 1, which is 10% by weight. 3. The aqueous ink composition according to claim 1, wherein the aqueous ink composition has a surface tension at 20 ° C. of 20 to 55 mN / m. 4. The colorant according to claim 1, wherein the colorant is a pigment.
4. The aqueous ink composition according to any one of 3. 5. The aqueous ink composition according to claim 1, wherein the aqueous ink composition is for inkjet recording. 6. An ink cartridge provided with an ink storage section for storing the aqueous ink composition according to claim 1.