JPH05148437A - Aqueous ink - Google Patents

Abstract

PURPOSE:To obtain aqueous ink excellent in dryness preventing effect, printing quality and solution stability and especially suitable for ink jet recording by further adding a salt of an amine and a hydroxy group-containing acid to water and a coloring agent. CONSTITUTION:The objective aqueous ink is obtained by adding a salt of an amine and an acid having a hydroxy group and an acidic group to water (preferably ion exchange water and a coloring agent (preferably water-soluble dye). As the amine, an alkanolamine such as triethanolamine or ethylene oxide derivative thereof is preferably used. Furthermore, though the amine and acid form the salt readily even when individually blended in ink, the amine and the acid are each preferably added thereto in amounts of 0.1-10%.

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, and more particularly to a water-based ink having excellent dissolution stability and anti-drying effect and excellent printing quality, and more particularly to a water-based ink suitable for ink jet recording.

[0002]

2. Description of the Related Art Conventional inks for ink jet printers are classified into so-called oil-based inks in which an oil-soluble dye is dissolved in an organic solvent and so-called water-based inks in which a water-soluble dye is dissolved in water. While the oil-based ink has excellent water resistance, it has many problems such as safety and bleeding of printing on odor plain paper. Therefore, water-based ink is often used for general inkjet recording.

Colorants used in water-based inks include
Although pigments and dyes that can be dispersed or dissolved in water have been generally proposed, the usual inkjet recording method is 10 to 20.
Since it is a method of ejecting ink from a fine nozzle of 0 micron, there is always a risk of nozzle clogging. Most of the colorants actually used are water-soluble dyes excellent in dissolution stability, and among them, anionic direct dyes and acid dyes are used. However, water in the water-based ink evaporates,
It has a drawback that nozzle clogging is likely to occur. In order to improve the above drawbacks, various anti-drying agents (wetting agents) have been proposed in the past.

That is, dimethyl sulfoxide; 1,3
-Dimethyl-2-pyrrolidinone; ethylene glycol,
Polyhydric alcohols such as diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, and glycerin; pyrrolidones such as N-methyl-2-pyrrolidone; Has been used for.

Further, in JP-A-58-183768, alkanolamine salts of fatty acids are disclosed in JP-A-58-877.
No. 0 publication discloses ethylenediamine having a specific structure,
In JP-A-60-58478, polyethylene polyamine having a specific structure is disclosed in JP-A-63-215781.
In Japanese Patent Application Laid-Open No. 2003-242242, an aqueous ink containing a polyamine compound and a phosphate compound as essential components is proposed.

[0006]

The above-mentioned anti-drying agent is
When an attempt is made to increase the anti-drying effect, the amount of anti-drying agent added increases and the bleeding of printing deteriorates. Conversely, when an attempt is made to reduce the bleeding of printing, the amount of anti-drying agent added decreases and the anti-drying effect deteriorates It had drawbacks. In view of the above points, it is an object of the present invention to provide a water-based ink having an excellent anti-drying effect, an excellent printing quality, and an excellent solubility stability, particularly an aqueous ink suitable for inkjet recording.

[0007]

The present inventors have arrived at the present invention as a result of intensive studies to solve the above problems.

The present invention relates to an aqueous ink containing water and a colorant, which contains a salt of an amine and an acid having at least one hydroxyl group and an acidic group. is there.

The amine of the present invention is a compound having one or more primary, secondary, and tertiary amines in its chemical structure, and may exhibit solubility in water in an amount not less than the required amount when combined with an acid. Any kind is acceptable, but it is necessary to select the type and molecular weight depending on the dye to be combined.

Specifically, the following compounds are used. Amine 1 triethanolamine amine 2 diethanolamine amine 3 monoethanolamine amine 4 N-methyl-diethanolamine amine 5 N-ethyl-diethanolamine amine 6 ethylenediamine amine 7 diethylenetriamine amine 8 triethylenetetramine amine 9 tetraethylenepentamine amine 10 polyethyleneimine amine 11 Pentamethyldiethylenetriamine amine 12 Tetramethylpropylenediamine amine 13 Tetraethylene pentamine ethylene oxide 3 mol.
Propylene oxide 1 mol adduct Amine 14 Polyallylamine Amine 15 Polyamide polyamine Epichlorohydrin

The acid of the present invention is an acid having one or more hydroxyl groups (hereinafter referred to as "acid"), and shows any solubility in water in a required amount or more when combined with the amine. However, it is necessary to select the type and molecular weight depending on the dye to be combined.

Specifically, they are the following compounds. Acid 1 Glycolic Acid 2 Lactic Acid 3 Citric Acid 4 Tartaric Acid 5 Glyceric Acid 6 Tropaic Acid 7 Tropic Acid 7 Benzyl Acid 8 Ethylene Oxide 2 Mol Adduct of Lactic Acid 9 p-Hydroxybenzoic Acid 10 Glycerophosphoric Acid

The amine salt and the acid salt of the present invention can easily form a salt even if they are separately blended in the ink, and the addition amount of each is not unconditionally specified, but 0.1% to 10%. The range is more preferable, and if possible, it is necessary to suppress the amount of addition so as not to impair the anti-drying effect in consideration of bleeding on the recording paper. The ratio is alkaline when the amine is equal to or more than the equivalent, and acidic when the ratio is equal to or less than that, so it may be set to any pH in accordance with the dissolution stability of the colorant, but the amine and the acid are neutralized with the equivalent amount, You may set to arbitrary pH with another pH adjuster. Also, a plurality of amines and acids may be used in combination,
Compounds other than the above-mentioned compound examples can be used, and when the number of nitrogen atoms in the amine is large, there is also an advantage that the water resistance of the printed matter is improved.

The water-based ink according to the present invention containing a salt of an amine and an acid having one or more hydroxyl groups and an acid group has an excellent anti-drying effect, an excellent printing quality, and a dissolution stability. Are better.

The aqueous ink composition in which the salt comprises an amine and an oxyacid having one or more hydroxyl groups and a carboxyl group as substituents exhibits particularly excellent effects.

The water-based ink composition in which the amine is an alkanolamine and its ethylene oxide derivative has a particularly remarkable improving effect.

The water-based ink composition in which the oxy acid is glycolic acid, lactic acid or glyceric acid has a particularly remarkable improving effect.

Therefore, when the water-based ink of the present invention is used in an ink jet printer, an excellent anti-drying effect and print quality can be obtained, and an excellent dissolution stability can be obtained.

In the present invention, other water-soluble organic solvent may be used in combination, and examples of the water-soluble organic solvent include methyl ether, ethyl ether, isopropyl ether, n-propyl ether and isobutyl ether of ethylene glycol or propylene glycol. , N-butyl ether, glycol ethers such as substituted or unsubstituted phenyl ether, dimethyl ether and diethyl ether; dimethyl sulfoxide; polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol and glycerin; ethanol , Lower alcohols such as isopropyl alcohol, pyrrolidones such as N-methyl-2-pyrrolidone, and the like, and these water-soluble organic solvents include
They can be used alone or in combination. However, the water-soluble organic solvent that can be used in the present invention is not limited to these.

As the colorant, general dyes and pigments can be used, but water-soluble dyes having excellent solubility stability are particularly preferable, and any water-soluble dye can be used. , Basic dyes, direct dyes, reactive dyes, disperse dyes, food dyes, optical brighteners and the like.

Specifically, as the acid dye, for example,
C. I. Acid Black 1, 2, 7, 16, 17,
24, 26, 28, 31, 41, 48, 52, 58, 6
0, 63, 94, 107, 109, 112, 118, 1
19, 121, 122, 131, 155, 156; C.I.
I. Acid Yellow 1,3,4,7,11,12,
13, 14, 17, 18, 19, 23, 25, 29, 3
4,36,38,40,41,42,44,49,5
3,55,59,61,71,72,76,78,7
9, 99, 111, 114, 116, 122, 135,
142, 161, 172; C.I. I. Acid Orange 7,8,10,19,20,24,28,33,41,
45, 51, 56, 64; C.I. I. Acid Red 1,4,6,8,13,14,15,18,19,2
1, 26, 27, 30, 32, 34, 35, 37, 4
0, 42, 51, 52, 54, 57, 80, 82, 8
3,85,87,88,89,92,94,97,10
6, 108, 110, 111, 114, 115, 11
9,129,131,133,134,135,14
3,144,152,154,155,172,17
6,180,184,186,187,249,25
4,256,289,317,318; C.I. I. Acid Violet 7, 11, 15, 34, 35, 41,
43, 49, 51, 75; C.I. I. Acid Blue 1,7,9,15,22,23,25,27,29,4
0, 41, 43, 45, 49, 51, 53, 55, 5
6,59,62,78,80,81,83,90,9
2, 93, 102, 104, 111, 113, 117,
120,124,126,138,145,167,1
71,175,183,229,234,236,24
9; C.I. I. Acid Green 3,9,12,16,1
9, 20, 25, 27, 41, 44; C.I. I. Acid Brown 4, 14 and the like.

Examples of the basic dye include C.I. I. Basic Black 2,8; C.I. I. Basic Yellow 1, 2, 11, 12, 14, 21, 32, 36; C.I.
I. Basic Orange 2,15,21,22; C.I.
I. Basic Red 1, 2, 9, 12, 13, 3
7; C.I. I. Basic Violet 1,3,7,1
0,14; C.I. I. Basic Blue 1, 3, 5,
7, 9, 24, 25, 26, 28, 29; C.I. I. Basic Green 1,4; C.I. I. Basic brown 1, 12 and the like can be mentioned.

Examples of direct dyes include C.I. I. Direct Black 2,4,9,11,14,17,1
9, 22, 27, 32, 36, 38, 41, 48, 4
9,51,56,62,71,74,75,77,7
8, 80, 105, 106, 107, 108, 112,
113, 117, 132, 146, 154, 168, 1
71, 194; C.I. I. Direct Yellow 1, 2,
4,8,11,12,24,26,27,28,33,
34, 39, 41, 42, 44, 48, 502, 51,
58, 72, 85, 86, 87, 88, 98, 100,
110, 127, 135, 141, 142, 144;
C. I. Direct Orange 6,8,10,26,2
9, 41, 49, 51, 102; C.I. I. direct
Red 1, 2, 4, 8, 9, 11, 13, 152, 1
7, 20, 23, 24, 28, 31, 33, 37, 3
9,44,46,47,48,51,59,62,6
3,73,75,77,80,81,83,84,8
5,87,89,90,94,95,99,101,1
08,110,145,189,197,220,22
4,2252,226,227,230,250,25
4,256,257; C.I. I. Direct Violet 1,7,9,12,35,48,51,90,94;
C. I. Direct Blue 1,2,6,8,15,2
2,25,34,69,70,71,72,75,7
6,78,80,81,82,83,86,90,9
8, 106, 108, 110, 120, 123, 15
8,163,165,192,193,194,19
5,196,199,200,201,202,20
3,207,218,236,237,239,24
6,258,287; C.I. I. Direct Green 1, 6, 8, 28, 33, 37, 63, 64; C.I. I.
Direct Brown 1A, 2, 6, 25, 27, 4
4,58,95,100,101,106,112,1
73, 194, 195, 209, 210, 211 and the like.

Examples of reactive dyes include C.I. I. Reactive Black 1,3,5,6,8,12,1
4; C.I. I. Reactive Yellow 1, 2, 3, 1
3,14,15,17; C.I. I. Reactive Orange 2,5,7,16,20,24; C.I. I. Reactive Red 6,7,11,12,15,17,21,2
3,24,35,36,42,63,66,84,18
4; C.I. I. Reactive Violet 2,4,5,5
8, 9; C.I. I. Reactive Blue 2, 5, 7, 1
2,13,14,15,17,18,19,20,2
1,25,27,28,37,38,40,41; C.I.
I. Reactive Green 5,7; C.I. I. Reactive Brown 1, 7, 16 and the like can be mentioned.

Examples of food dyes include C.I. I. Hood Black 1, 2; C.I. I. Hood yellow 2,
4,5; C.I. I. Hood Red 2,3,7,9,1
4, 52, 87, 92, 94, 102, 104, 10
5,106; C.I. I. Hood Violet 2: C.I.
I. Food Blue 1, 2; C.I. I. Food green 2, 3 etc. are mentioned.

Other water-soluble dyes include, for example, "Kayaset Black 9A", "Direct Deep Black XA" and "Direct Special Black AXN" manufactured by Nippon Kayaku Co .; Special Black SP Liquid "," Biscript
"Black SP Liquid", "Levacell Turquoise Blue KS-6GLL", "Pyranin";"JI.BK-2","JI.BK-3" manufactured by Sumitomo Chemical Co., Ltd .; "JP-K81L" manufactured by Orient Chemical Co., Ltd. , "JP-K127
L "," JPK-139 "; C.I. I. Florescent
Brightening Agents 14, 22, 24, 3
2, 84, 85, 86, 87, 90, 134, 166
167, 169, 175, 176, 177 and the like.

These colorants can be used alone or in combination of two or more, and the amount used in the ink composition is 0.1 to 10.
A weight% range is desirable.

The water is preferably one having a purity higher than that of ion-exchanged water in order to prevent the dissolution stability of the dye and the nozzle clogging due to heavy metal ions. The amount of water, water-soluble dye, or water-soluble organic solvent added can be appropriately determined in consideration of the properties required of the ink and the required physical properties.

In addition, additives such as antiseptic / antifungal agents, heavy metal sequestering agents, and pH adjusters can be used in the ink jet recording ink of the present invention.

[0030]

The salt of an amine and an acid according to the present invention not only exhibits extremely strong hygroscopicity and produces a drying prevention effect,
Unlike other inorganic salts, there is little salting out effect on dyes,
It is considered that dissolution stability is not impaired.

[0031]

EXAMPLES Next, the present invention will be described more specifically with reference to Examples and Comparative Examples. The parts in the text are based on weight.

Example 1 Salt of amine 1 and acid 2 3.0 parts Isopropyl alcohol 5.0 parts Diethylene glycol 5.0 parts C.I. I. Direct Black 19 2.0 parts Ion-exchanged water balance The above components were mixed and dissolved, and then filtered through a membrane filter having a pore size of 0.5 μm to obtain an aqueous ink of the present invention.

The aqueous ink obtained did not generate any precipitate even after being left for 6 months. Further, the ink was mounted on a drop-on-demand type inkjet printer using a piezo, and continuous printing and reprinting after standing for 2 weeks were performed, but the ejection stability was good and the printing quality was also good.

Example 2 Salt of amine 4 with acid 1 4.0 parts C.I. I. Food Black 2 3.0 parts Ion-exchanged water balance The above components were mixed and dissolved, and then filtered through a membrane filter having a pore size of 0.5 μm to obtain an aqueous ink of the present invention.

The resulting aqueous ink did not generate any deposits even after being left for 6 months. Further, the recording medium was mounted on a thermal jet type ink jet printer that uses heat energy for recording, and continuous printing and reprinting after standing for 2 weeks were performed, but the ejection stability was good and the printing quality was also good.

Example 3 Salt of amine 11 and acid 3 4.2 parts Diethylene glycol 10.0 parts C.I. I. Direct Blue 199 2.0 parts Ion-exchanged water Remainder After mixing and dissolving the above components, the remaining components were additionally dissolved and filtered with a membrane filter having a pore size of 0.5 μm to obtain an aqueous ink of the present invention.

The resulting water-based ink did not generate any precipitate even after standing for 6 months. Further, the ink jet printer was mounted on a continuous type ink jet printer, and continuous printing and reprinting after standing for 2 weeks were performed, but the ejection stability was good and the printing quality was also good.

Comparative Example 1-1 The components of the amine 1 and the acid 2 in Example 1 were replaced by the acid 2 instead of the salt, and the mixture was dissolved and filtered through a membrane filter having a pore size of 0.5 μm to obtain an aqueous ink. It was

The obtained water-based ink had a slight amount of precipitate generated after standing for 6 months. Further, it was mounted on a drop-on-demand type inkjet printer using a piezo, and continuous printing was performed, but the ejection stability was good. However, two weeks after removing the cap, reprinting revealed that the nozzle was clogged.

Comparative Example 1-2 Amine 1 was replaced with the salt of acid 2 of Example 1, and each component of amine 1 was mixed and dissolved, followed by filtration with a membrane filter having a pore size of 0.5 μm to obtain an aqueous ink. It was

The resulting water-based ink did not generate any precipitate even after standing for 6 months. Further, the ink was mounted on a drop-on-demand type inkjet printer using a piezo, and continuous printing was performed, but the ejection stability was good. However, two weeks after removing the cap, reprinting revealed that the nozzle was clogged.

Comparative Example 2-1 Amine 4 of Example 2 and each component of acid 1 in place of the salt of acid 1 were mixed and dissolved, and filtered through a membrane filter having a pore size of 0.5 μm to obtain an aqueous ink. It was

The obtained water-based ink had a slight amount of precipitate generated after standing for 6 months. Further, the recording was mounted on a thermal jet type ink jet printer that uses thermal energy for recording, and continuous printing was performed, but the ejection stability was good. However, two weeks after removing the cap, reprinting revealed that the nozzle was clogged.

Comparative Example 2-2 Amine 4 of Example 2 and each component of amine 4 in place of the salt of acid 1 were mixed and dissolved, and filtered through a membrane filter having a pore size of 0.5 μm to obtain an aqueous ink. It was

The resulting water-based ink did not generate any precipitate even after standing for 6 months. In addition, when the ink jet printer of the thermal jet type that uses heat energy for recording was used and continuous printing was performed, ejection stability was good. However, two weeks after removing the cap, reprinting revealed that the nozzle was clogged.

Comparative Example 3-1 Amine 11 of Example 3 and each component of acid 3 in place of acid 3 were mixed and dissolved, and filtered through a membrane filter having a pore size of 0.5 μm to obtain an aqueous ink.

The resulting aqueous ink had a slight amount of precipitates generated after standing for 6 months. Further, it was mounted on a continuous type inkjet printer and continuous printing was performed, but the ejection stability was good. However, two weeks after removing the cap, reprinting revealed that the nozzle was clogged.

Comparative Example 3-2 Amine 11 of Example 3 and each component using amine 11 instead of acid 3 were mixed and dissolved, and filtered through a membrane filter having a pore size of 0.5 μm to obtain an aqueous ink.

The resulting water-based ink did not generate any precipitate even after standing for 6 months. In addition, when it was mounted on a continuous type inkjet printer and continuous printing was performed, the ejection stability was good. However, two weeks after removing the cap, reprinting revealed that the nozzle was clogged.

The ink of the present invention can be used not only as a jet printer but also as a water-based ink for any recording system.

[0051]

The water-based ink according to the present invention containing a salt of an amine and an acid having at least one hydroxyl group and an acid group has an excellent anti-drying effect, an excellent printing quality, and a stable dissolution. It has excellent properties.

Therefore, when the water-based ink of the present invention is used in an ink jet printer or the like, an excellent anti-drying effect and print quality can be obtained, and an excellent dissolution stability can be obtained.

Claims (4)

[Claims] 1. An aqueous ink containing water and a colorant, which contains a salt of an amine and an acid having at least one hydroxyl group and an acidic group. 2. The water-based ink according to claim 1, wherein the salt comprises an amine and an oxyacid having at least one hydroxyl group and a carboxyl group. 3. The water-based ink according to claim 1 or 2, wherein the amine is an alkanolamine and an ethylene oxide derivative thereof. 4. The aqueous ink according to claim 2, wherein the oxyacid is glycolic acid, lactic acid, or glyceric acid.