JP2003003098A - Aqueous printing liquid, printing method and device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide aqueous ink for use in ink jet printing that has enhanced permeability without impairing jet stability and storage stability, an ink jet printing method and a device using the same. SOLUTION: This aqueous ink for use in ink jet printing contains water dispersible or water soluble colorant, wherein it is characterized in that the ink contains polyoxyethylene alkyl ether based surface active agent and polyoxyethylene alkyl ether acetic acid salt based surface active agent.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an aqueous ink suitable for ink jet recording such as an on-demand method such as a piezo method or a thermal method or a continuous jet method such as a charge control method, and particularly excellent characteristics for so-called plain paper. Is a water-based ink.

[0002]

2. Description of the Related Art In recent years, the ink jet recording system has been rapidly spread in recent years because of its advantages such as small size, low price, low running cost and low noise. Electrophotographic transfer paper, printing paper, typewriter paper, wire. Dot printer paper, word processor paper, letter paper,
Inkjet printers that can print on various non-coated plain papers such as report papers are also on the market. In these inkjet printers, inks having improved drying properties have been proposed so that higher quality images can be obtained.

However, image color reproducibility, water resistance,
It is difficult to satisfy all of light resistance, image drying property, image bleeding, and ejection reliability. In particular, in the case of a color printer, even if there is no image quality deterioration in the yellow, magenta, and cyan single-color printing portions, the image quality deterioration easily occurs in the three-color overlapping portion of red, green, and blue. In particular, when drying is performed without using a fixing device, the drying property is improved by increasing the permeability as in JP-A-55-29546, but this causes remarkable blurring of the paper. For this reason,
Up to now, attempts have been made to suppress ink bleeding and enhance penetrability. To give an example, Japanese Patent No. 2894568 discloses a composition containing a dye and a liquid medium, wherein 60% by weight or more of water and 0.2 to 30% by weight are contained in the liquid medium.
An inkjet ink containing an alkylene glycol having 7 to 10 carbon atoms has been proposed. Preferred specific examples of the "alkylene glycol having 7 to 10 carbon atoms" are 1,7-heptanediol, 2,6-heptanediol, 2,4-dimethyl-2,4-pentanediol, 3-ethyl-1, 3-Pentanediol and the like are exemplified. Further, Japanese Patent No. 2714482 discloses that water 100 having at least 6 carbon atoms and having a temperature of 25 ° C is used.
Inkjet inks have been proposed which contain an aliphatic diol compound of a specific structure having a solubility of at least 4.5 parts by weight in parts by weight. As these diol compounds, 2-ethyl-2-methyl-1,3-propanediol, 3,3-dimethyl-1,2-butanediol, 2,
2-diethyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2,4-
Dimethyl-2,4-pentanediol, 2,5-dimethyl-2,5-hexanediol, 5-hexene-1,2
-Diols and the like are exemplified. These are "improved ink bleeding, drying and penetration on plain paper."
However, it is not sufficient in terms of "balanced in terms of bleeding and penetrability" and "reliable in terms of ejection stability and storage stability". In particular, by adding the various substances mentioned above for improving the permeability,
In many cases, even if the penetrability was slightly improved, the reliability of ejection stability and storage stability decreased due to aggregation and precipitation of the coloring material.

Therefore, as a result of extensive studies, the applicant of the present invention proposed an aqueous ink containing 2-ethyl-1,3-hexanediol for the purpose of enhancing the permeability in JP-A-6-157959. However, it was not sufficient in that the dispersion stability of the coloring material is lowered. Furthermore, Japanese Patent Laid-Open No. 6-1
Japanese Patent Publication No. 07990 proposes an aqueous ink containing a polyoxyethylene alkyl ether acetate-based surfactant for the same purpose, and Japanese Patent Laid-Open Publication No. 7-70491 proposes an aqueous ink containing a polyoxyethylene alkyl ether-based surfactant. did. In the former case, the problem of foaming is likely to occur, and in the case of high-speed printing, there is a problem such as poor penetration depending on the paper type, and in the latter case, due to the interaction with the coloring material, the dye ink Had a problem such as a decrease in permeability, and a pigment ink had a decrease in dispersibility. In recent years, due to rapid technological progress, the output speed of inkjet printers has been steadily increasing, and it is not hard to imagine that the speed will increase further in the future. Under such circumstances, it is required that the ink does not cause color bleeding even in high-speed printing, and that after the output, the ink is immediately dried without being contaminated by rubbing. On the other hand, a high-resolution image with minimal blurring is also required at the same time. In addition to satisfying these conditions, highly reliable ink such as ejection stability and storage stability is required. In the current state of the art, the above-mentioned conditions have not been fully satisfied.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and its object is to maintain the ejection stability and the storage stability, which are the problems of the prior art described above. Another object of the present invention is to provide a water-based ink for inkjet recording having improved permeability, an inkjet recording method using the same, and a device using the ink.

[0006]

Means for Solving the Problems The above-mentioned problems are (1) "a water-based ink for ink-jet recording containing a colorant which is dispersed or dissolved in water, which comprises a polyoxyethylene alkyl ether-based surfactant and a polyoxyethylene An aqueous ink for ink jet recording characterized by containing an ethylene alkyl ether acetate-based surfactant ", (2)" a polyoxyethylene alkyl ether-based surfactant is represented by the following general formula (1): The water-based ink for inkjet recording according to item (1) above,

[0007]

Embedded image R ₁ O (CH ₂ CH ₂ O) pH (1) (In the formula (1), R ₁ is an optionally branched alkyl group having 8 to 14 carbon atoms. P is 1 to 30. Represents an integer.) ",
(3) "Aqueous ink for inkjet recording according to the item (2), which has a branched structure of an alkyl group of R _{1 in} the structure represented by the general formula (1)",
(4) “A polyoxyethylene alkyl ether acetate surfactant is represented by the following general formula (2):

[0008]

[Chemical 5] (In the formula (2), R ₂ is an alkyl group having 8 to 14 carbon atoms which may be branched. Q is an integer of 3 to 12, M is an alkali metal ion, a quaternary ammonium, a quaternary phosphonium, or an alkanol. Represents an amine.) ”, (5)“ In addition to the above-mentioned components, the solubility in water at 20 ° C. is 0.
2% by weight or more and less than 4.5% by weight of a polyol is contained, (6) The aqueous ink for ink jet recording according to the above item (1), wherein the polyol is represented by the following general formula (3). The water-based ink for inkjet recording according to item (5) above, which is a 1,3-diol.

[0009]

[Chemical 6] (In the formula (3), R ₁ and R ₂ are hydrogen or an alkyl group, and R ₃ is an alkyl group. R ₁ and R ₂ are not hydrogen at the same time, and R ₁ , R ₂ and R ₃ (Total carbon number is 3 to 9) ", (7)" 1,3-diol is 2
-Ethyl-1,3-hexanediol, wherein the aqueous ink for inkjet recording according to item (6) above is (8) "2,2,4-trimethyl-1 is 1,3 diol. And (3) pentanediol, the aqueous ink for ink jet recording according to the above item (6), (9) "wherein the colorant is a pigment, according to the above item (1). (10) "Ink jet recording water-based ink", (10) "Pigment is dispersed in a surfactant, and the ink jet recording water-based ink according to the above (9)", (11) " The ink for inkjet recording according to item (9), wherein the pigment is dispersed with a polymer dispersant.
Achieved by

Further, the above-mentioned problem is (12) of the present invention, wherein the water-based ink jet recording ink according to any one of (1) to (11) above is ejected as a droplet from a fine ejection port. , And a recording method characterized by forming an image on a recording medium by flying.

Further, the above-mentioned problem is (13) of the present invention, "In an ink cartridge having an ink containing portion containing ink, the ink is the above-mentioned items (1) to (1).
1) An ink cartridge characterized by being the water-based ink for inkjet recording according to any one of 1) above,
(14) “In an ink cartridge having an ink containing portion containing ink and a head portion for ejecting ink droplets, the inkjet recording water-based ink is any one of the items (1) to (11). Or an ink cartridge according to item 1).

Furthermore, the above-mentioned problem is (15) of the present invention.
“An ink jet recording apparatus provided with an ink cartridge having an ink containing portion containing ink and a recording head for ejecting recording droplets, or an ink containing portion containing ink and ejecting ink droplets An ink jet recording apparatus provided with an ink cartridge having the recording head according to item (13), which is provided with the ink cartridge according to item (13) or (14).

By ejecting a water-based ink for ink jet recording containing a colorant dispersed or dissolved in water, a polyoxyethylene alkyl ether type surfactant and a polyoxyethylene alkyl ether acetate type surfactant, It was found that the stability and storage stability can be maintained and the permeability can be increased. When the polyoxyethylene alkyl ether-based surfactant is a compound represented by the following general formula (1),

[0014]

Embedded image R ₁ O (CH ₂ CH ₂ O) pH (1) (In the formula (1), R ₁ is an alkyl group having 8 to 14 carbon atoms which may be branched. P is 1 to 30. Represents an integer.)

The polyoxyethylene alkyl ether acetate-based surfactant is effective when it is represented by the following general formula (2).

[0016]

[Chemical 8] (In the formula (2), R ₂ is an alkyl group having 8 to 14 carbon atoms which may be branched. Q is an integer of 3 to 12, M is an alkali metal ion, a quaternary ammonium, a quaternary phosphonium, or an alkanol. Represents an amine.)

In addition to the above-mentioned components, it is effective to further contain a polyol having a solubility in water at 20 ° C. of 0.2% by weight or more and less than 4.5% by weight. A polyol having a solubility in water at 20 ° C of 0.2% by weight or more and less than 4.5% by weight is easily adsorbed on the surface in a recording liquid containing water as a main component, and has a molecular weight comparable to that of a so-called surfactant. Since it is relatively small, the adsorption rate on the surface is extremely high. That is, by adsorbing the polyol on the surface, it is possible to quickly reduce the surface tension of the liquid like a surfactant. However, since the difference in hydrophilicity / hydrophobicity between polyols is smaller than that of surfactants, it is not possible to obtain high penetrability only with polyols, and it is possible to further improve the penetrability by using the polyols together. it can. When the polyol having a solubility in water at 20 ° C. of 0.2% by weight or more and less than 4.5% by weight is 1,3-diol represented by the following general formula (3), the improvement of the penetration characteristics is more effective. Since it requires only a small amount of addition, it is more preferable in terms of safety and odor. The reason for this is not clear, but since 1,3-diol as represented by the general formula (3) has an asymmetric and branched structure in the molecular structure, the adsorption efficiency and speed on the surface are improved, and thus the permeation is improved. We believe that the efficiency can be improved efficiently.

[0018]

[Chemical 9] (In the formula (3), R ₁ and R ₂ are hydrogen or an alkyl group, and R ₃ is an alkyl group. R ₁ and R ₂ are not hydrogen at the same time, and R ₁ , R ₂ and R ₃ (The total carbon number is 3-9)

More preferably, the 1,3 diol is 2-
It is selected from ethyl-1,3-hexanediol (solubility in water at 20 ° C .: 4.2%) and 2,2,4-trimethyl-1,3-pentanediol (solubility in water at 20 ° C .: 2%). At least one is preferable from the viewpoint of safety and storage stability of the obtained recording liquid. Further, all of them are industrially useful materials, and since they are handled in a relatively large amount, there is an advantage that the ink can be produced at a relatively low cost.

In the present invention, when the colorant is a pigment, particularly a color pigment, and when the pigment is dispersed with a surfactant or a polymer dispersant, agglomeration due to the additive is likely to occur, which is very effective. Target. Further, the present invention relates to a recording method for forming an image on a recording medium by ejecting and ejecting the above ink as droplets from a fine ejection port, an ink cartridge including an ink containing portion containing the above ink, and this ink cartridge. The present invention proposes an inkjet recording apparatus including a recording head for ejecting ink droplets.

The present invention will be described in detail below. The polyoxyethylene alkyl ether type surfactant and the polyoxyethylene alkyl ether acetate type surfactant used in the present invention preferably have the following structures. That is, the polyoxyethylene alkyl ether-based surfactant is represented by the following general formula (1).

[0022]

Embedded image R ₁ O (CH ₂ CH ₂ O) pH (1) (In the formula (1), R ₁ is an alkyl group having 8 to 14 carbon atoms which may be branched. P is 1 to 30. Further, the polyoxyethylene alkyl ether acetate-based surfactant is represented by the following general formula (2).

[0023]

[Chemical 11] (In the formula (2), R ₂ is an alkyl group having 8 to 14 carbon atoms which may be branched. Q is an integer of 3 to 12, M is an alkali metal ion, a quaternary ammonium, a quaternary phosphonium, or an alkanol. Represents an amine.)

The ink of the present invention is excellent in storage stability, has high wettability of the ink with respect to the paper surface and has a high penetration rate into the paper regardless of the paper type, and has a higher permeability as compared with conventionally known inks. , Image deterioration is extremely small. Further, when used in an ink jet recording method, it exhibits excellent ejection characteristics without causing nozzle clogging. Furthermore, such excellent properties can be obtained in combination with various colorants.

Specific examples of the compounds represented by the general formulas (1) and (2) are shown below in the free acid form of the compounds which form salts. First, as the compound represented by the general formula (1),

[0026]

[Table 1]

Examples thereof include, but are not limited to: Moreover, these may be used individually or may be used in mixture of multiple things. Even when it is not easily dissolved in the ink by itself, it can be solubilized by mixing and can exist stably. The present invention exerts a particularly remarkable effect in the case of a compound in which R ₁ of the general formula (1) is branched,
Commercially available surfactants containing this compound as a main component include BT available from Nikko Chemicals Co., Ltd.
Series, the Softanol series available from Nippon Shokubai Co., Ltd., and Dispanol available from NOF CORPORATION. Next, as the compound represented by the general formula (2),

[0028]

[Table 2]

Examples thereof include, but are not limited to: These compounds have particularly high penetrability when q is 6 or less in the general formula (2), but when q is 7 or more, the penetrating effect decreases, but the dispersibility of the colorant improves. Therefore, it can be selected depending on the colorant used. Moreover, these may be used individually or may be used in mixture of multiple things. Even if it is not easily dissolved in the recording liquid by itself, it can be solubilized by mixing and can exist stably. Further, it is preferable to purify and remove the inorganic salt produced as a by-product during the synthesis with an ion exchange resin. Commercially available surfactants containing this compound as a main component include NIKKOL ECT series, NIKKOL AKYPO series available from Nikko Chemicals Co., Ltd., and Beaulite series available from Sanyo Kasei Co., Ltd. Activators can also be used.

The compound represented by the general formula (2) is usually used in the form of a salt, and as its counter ion, an alkali metal ion, quaternary ammonium, quaternary phosphonium,
Alternatively, alkanolamine is preferred. Further, sodium, lithium and / or a quaternary ammonium, quaternary phosphonium or alkanolamine cation represented by the following general formula (4) is used as a counter ion, which is more preferable because the dissolution stability is further increased.

[0031]

[Chemical 12] (In the formula (4), Y represents nitrogen or phosphorus, and R _{1 to} R ₁
Each of ₄ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group, or a halogenated alkyl group. ) For example, in the case of a lithium salt, it is carried out by adding lithium hydroxide. Regarding the quaternary ammonium, phosphonium, and alkanolamine cations of the general formula (4), specifically, the hydroxides shown below are used. It is performed by adding.

[0032]

[Table 3]

Further, the recording liquid of the present invention, together with the polyoxyethylene alkyl ether type surfactant and the polyoxyethylene alkyl ether acetate type surfactant, has a solubility of 0.2 at 20 ° C. in water as described above.
It is more effective to contain the polyol in an amount of not less than 4.5% by weight and not more than 4.5% by weight. In particular, among the polyols, the diol represented by the following general formula (3) is effective, and among them, by containing 2,2,4-trimethyl-1,3-pentanediol, it has extremely high permeability, and It is possible to obtain a stable and highly safe recording liquid without separation in the liquid.

[0034]

[Chemical 13] (In the formula (3), R ₁ and R ₂ are hydrogen or an alkyl group, and R ₃ is an alkyl group. R ₁ and R ₂ are not hydrogen at the same time, and R ₁ , R ₂ and R ₃ (The total carbon number is 3-9)

Next, the amount added in the recording liquid will be described. The total addition amount of the polyoxyethylene alkyl ether type surfactant and the polyoxyethylene alkyl ether acetate type surfactant is 0.01 with respect to the total amount of the recording liquid.
If it is less than 5% by weight, the improvement of permeability will be insufficient, and if it is more than 4% by weight, it will not be stably dissolved in the recording liquid, or the viscosity will increase even if it is dissolved, resulting in storage stability of the recording liquid. However, there is a problem in jetting stability with an inkjet. A more preferable total amount of the polyoxyethylene alkyl ether-based surfactant and the polyoxyethylene alkyl ether acetate-based surfactant added is 0.05% by weight or more and 2% by weight or less. Further, in the case of adding a polyol, if the amount added is less than 0.1% by weight based on the total amount of the recording liquid, the improvement of the penetrability is insufficient, and if it is more than 8% by weight, the amount in the recording liquid is increased. Does not dissolve stably and causes problems in storage stability of recording liquid and jetting stability in inkjet. More preferably, the added amount is 0.5% by weight or more and 5% by weight or less.

The recording liquid of the present invention contains 5% by weight to 50% by weight of a wetting agent for the purpose of preventing clogging due to drying of the recording liquid and improving the dissolution stability of the recording liquid of the present invention. Even if the water in the recording liquid evaporates, the ejection port of the inkjet head is less likely to cause clogging and normal printing can be performed. Even if clogging occurs, normal printing can be performed with a simple cleaning operation. As the wetting agent which can be recovered, a low volatile water-soluble organic solvent is preferable.

As the low volatile water-soluble organic solvent,
Ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol, polypropylene glycol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol , 1,5-pentanediol, 2-methyl-2,4-pentanediol,
1,6-hexanediol, glycerin, 1,2,6-
Hexanetriol, 1,2,4-butanetriol,
Polyhydric alcohols such as 1,2,3-butanetriol and petriol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol Polyhydric alcohol alkyl ethers such as monoethyl ether, polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether; 2
-Nitrogen-containing heterocyclic compounds such as pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethylimidinazolidinone, ε-caprolactam, γ-butyrolactone; formamide, N-methyl Amides such as formamide, N, N-dimethylformamide; monoethanolamine, diethanolamine,
Examples thereof include amines such as triethanolamine, monoethylamine, diethylamine and triethylamine, sulfur-containing compounds such as dimethyl sulfoxide, sulfolane, thiodiethanol and thiodiglycol, propylene carbonate and ethylene carbonate. These solvents may be used alone or in combination with water.

Particularly, from the viewpoint of compatibility with polyoxyethylene alkyl ether type surfactants and polyoxyethylene alkyl ether acetate type surfactants, glycerin, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene. Glycol, tripropylene glycol, 1,3-
Butanediol, 2,3-butanediol, 1,4-butanediol, 1,5-pentanediol, tetraethylene glycol, 1,6-hexanediol, 2-methyl-2,4-pentanediol, polyethylene glycol, 1 , 2,4-butanetriol, 1,2,6-hexanetriol, thiodiglycol, 2-pyrrolidone,
N-methyl-2-pyrrolidone, N-hydroxyethyl-
2-pyrrolidone and 1,3-dimethyl-2-imidazolidinone are preferred. Further, it is preferable to use glycerin and diethylene glycol alone or in combination from the viewpoint of safety and price.

In order to obtain high image quality in the ink jet recording method, it is important to adjust the wettability of the recording liquid with respect to the members constituting the ink jet head. As described above, in order to adjust the wettability, it is possible to further add a surfactant to the recording liquid of the present invention. Examples of the surfactant include anionic surfactants such as ammonium salts of polyoxyethylene alkyl ether sulfates, cationic surfactants such as quaternary ammonium salts, and the like.
Amphoteric surfactants such as imidazoline derivatives, polyoxyethylene alkylphenyl ethers, polyoxyethylene alkyl esters, polyoxyethylene alkylamines, polyoxyethylene alkylamides, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, ethylene oxide of acetylene alcohol Examples include additives such as nonionic surfactants and fluorine-based surfactants. These surfactants are preferably added so that the recording liquid has desired physical properties.

The colorant used in the present invention may be either a dye or a pigment, but the present invention is particularly effective in the case of a color pigment. As the water-soluble dye used as the colorant, dyes classified into acid dyes, direct dyes, basic dyes, reactive dyes and food dyes in the color index are used. These dyes may be used as a mixture of a plurality of types, or may be used as a mixture with other dyes such as pigments if necessary. These colorants are added within a range that does not impair the effects of the present invention.

Specific examples of these dyes include acid dyes and food dyes such as C.I. I. Acid Yellow 17,23,42,4
4,79,142 C.I. I. Acid Red 1,8,13,14,1
8, 26, 27, 35, 37, 42, 52, 82, 8
7, 89, 92, 97, 106, 111, 114, 11
5,134,186,249,254,289 C.I. I. Acid Blue 9,29,45,92,2
49 C.I. I. Acid Black 1,2,7,24,2
6,94 C.I. I. Food Yellow 2,3,4 C.I. I. Hood Red 7, 9, 14 C.I. I. Hood black 1,2

As a direct dye, C.I. I. Direct Yellow 1,12,24,2
6, 33, 44, 50, 120, 132, 142, 14
4,86 C.I. I. Direct Red 1,4,9,13,1
7, 20, 28, 31, 39, 80, 81, 83, 8
9,225,227 C.I. I. Direct Orange 26,29,62,1
02 C. I. Direct Blue 1,2,6,15,2
2,25,71,76,79,86,87,90,9
8, 163, 165, 199, 202 C.I. I. Direct Black 19,22,32,3
8, 51, 56, 71, 74, 75, 77, 154, 1
68,171

As a basic dye, C.I. I. Basic Yellow 1, 2, 11, 13,
14,15,19,21,23,24,25,28,2
9, 32, 36, 40, 41, 45, 49, 51, 5
3,63,465,67,70,73,77,87,9
1 C. I. Basic Red 2,12,13,14,
15, 18, 22, 23, 24, 27, 29, 35, 3
6,38,39,46,49,51,52,54,5
9,68,69,70,73,78,82,102,1
04, 109, 112 C.I. I. Basic Blue 1,3,5,7,9,2
1, 22, 26, 35, 41, 45, 47, 54, 6
2,65,66,67,69,75,77,78,8
9, 92, 93, 105, 117, 120, 122, 1
24, 129, 137, 141, 147, 155 C.I. I. Basic Black 2,8

As a reactive dye, C.I. I. Reactive Black 3, 4, 7, 11,
12, 17 C.I. I. Reactive Yellow 1,5,11,1
3,14,20,21,22,25,40,47,5
1,55,65,67 C.I. I. Reactive Red 1,14,17,2
5,26,32,37,44,46,55,60,6
6,74,79,96,97 C.I. I. Reactive Blue 1,2,7,14,1
5,23,32,35,38,41,63,80,95 etc. can be used. As the dye, an acid dye and a direct dye can be preferably used, and the effects of improving the dissolution stability of the recording liquid of the present invention and excellent in color tone, water resistance and light resistance can be obtained. The addition amount of the dye as a coloring material in the recording liquid composition is preferably 0.5 to 25% by weight, more preferably 2 to 15% by weight.

As the pigment, an inorganic pigment or an organic pigment can be used without any particular limitation. Compared to dyes, it does not dissolve in the recording liquid and is dispersed as particles, so even a recording liquid with the same penetrating characteristics does not easily penetrate deep into the paper, so the image density is high and there is little strikethrough. It is possible to obtain excellent image quality.

As the inorganic pigment, in addition to titanium oxide and iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red and chrome yellow, known methods such as contact method, furnace method and thermal method are used. Carbon black can be used. As the organic pigment, azo pigments (azo lake, insoluble azo pigment, condensed azo pigment,
(Including chelate azo pigments), polycyclic pigments (eg,
Phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, quinoflaron pigments, etc., dye chelates (for example, basic dye chelates, acidic dye mers) Chelate), nitro pigment, nitroso pigment, aniline black, etc. can be used.

Of these pigments, those having a good affinity for water are preferably used. The addition amount of the pigment as a coloring material in the recording liquid composition is preferably 0.5 to 25% by weight, more preferably 2 to 15% by weight.

Specific examples of pigments preferably used in the present invention include furnace black for black,
Lamp black, acetylene black, channel black, and other carbon blacks (CI Pigment Black 7), or copper, iron (CI Pigment Black 1)
1), metals such as titanium oxide, aniline black (C.
I. Pigment Black 1) and other organic pigments. Further, for color, C.I. I. Pigment Yellow 1, 3, 12, 13, 14, 17, 24, 34,
35, 37, 42 (yellow iron oxide), 53, 55, 81,
83, 95, 97, 98, 100, 101, 104, 4
08,109,110,117,120,138,15
0,153, C.I. I. Pigment Orange 5,13,1
6, 17, 36, 43, 51, C.I. I. Pigment Red 1, 2, 3, 5, 17, 22, 23, 31, 38, 4
8: 2, 48: 2 (Permanent Red 2B (C
a)), 48: 3, 48: 4, 49: 1, 52: 2, 5
3: 1, 57: 1 (Brilliant Carmine 6B), 6
0: 1, 63: 1, 63: 2, 64: 1, 81, 83,
88, 101 (Bengara), 104, 105, 106,
108 (Cadmium red), 112, 114, 122
(Quinacridone magenta), 123, 146, 149,
166, 168, 170, 172, 177, 178, 1
79, 185, 190, 193, 209, 219, C.I.
I. Pigment Violet 1 (Rhodamine Rake),
3,5: 1,16,19,23,38, C.I. I. Pigment Blue 1, 2, 15 (Phthalocyanine Blue), 1
5: 1, 15: 2, 15: 3 (phthalocyanine blue), 16, 17: 1, 56, 60, 63, C.I. I. Pigment Green 1, 4, 7, 8, 10, 17, 18,
There are 36 mag.

According to a preferred embodiment of the present invention, the pigment in the recording liquid preferably has an average particle size in the range of 10 nm to 200 nm. The average particle size as used herein refers to a value of 50% of cumulative volume. Volume cumulative percentage 5
To measure the 0% value, the amount of change in the frequency (light frequency) of the light (backscattered light) returning from the particle is measured by irradiating the particles in the recording liquid that undergo Brownian motion with laser light. It is possible to use a method called a dynamic light scattering method (Doppler scattered light analysis) for obtaining the particle size from the above. As a particle size analyzer using this method, Microtrack particle size analyzer UPA150 manufactured by Honeywell Co., Ltd. is applicable. The pigment is preferably added to the recording liquid as a pigment dispersion obtained by dispersing it in an aqueous medium with a dispersant. As a preferable dispersant, a known dispersant used for preparing a conventionally known pigment dispersion liquid can be used. Examples of the polymer dispersant include the following. As a hydrophilic polymer, natural gum arabic, tragum gum, guar gum, karaya gum, locust bean gum, arabinogalactone, pectin, quince seed starch and other plant macromolecules, alginic acid, carrageenan, seaweed macromolecules such as agar, Gelatin, casein, albumin, animal-based polymers such as collagen, xanthene gum, microbial-based polymers such as dextran, in semi-synthetic systems methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, fibrin-based polymers such as carboxymethyl cellulose, Starch-based polymers such as sodium starch glycolate and starch phosphate sodium, seaweed-based polymers such as sodium alginate and propylene glycol alginate, and polyacetals in pure synthetic systems. Acid, polymethacrylic acid, acrylic acid-acrylonitrile copolymer, vinyl acetate-acrylic acid ester copolymer, acrylic acid-acrylic acid alkyl ester copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer Coal, styrene-acrylic acid-acrylic acid alkyl ester copolymer, styrene-methacrylic acid-acrylic acid alkyl ester copolymer, styrene-α
-Methylstyrene-acrylic acid copolymer, styrene-α
-Methylstyrene-acrylic acid copolymer-acrylic acid alkyl ester copolymer, styrene-maleic acid copolymer, vinylnaphthalene-maleic acid copolymer, vinyl acetate-ethylene copolymer, vinyl acetate-fatty acid vinylethylene copolymer Examples thereof include polymers, vinyl acetate-maleic acid ester copolymers, vinyl acetate-crotonic acid copolymers and vinyl acetate-acrylic acid copolymers.

These copolymers have a weight average molecular weight of 3,
It is preferably 000 to 50,000, more preferably 5,000 to 30,000, and most preferably 7.0.
It is 00 to 15,000. The amount of polymer dispersant added is
The pigment may be added appropriately as long as the pigment is stably dispersed and the other effects of the present invention are not lost. The ratio of the pigment to the dispersant is preferably in the range of 1: 0.06 to 1: 3, more preferably 1: 0.125 to 1: 3.

It is also possible to use a water-soluble surfactant as a pigment dispersant. In this case, the increase in ink viscosity with respect to the amount used is smaller than that when a polymer dispersant is used, and it is easy to obtain a pigment ink having good ejection characteristics when used in an inkjet recording method. Specific examples of the water-soluble surfactant used as a pigment dispersant include, for example, anionic surfactants such as alkylallyl or alkylnaphthalene sulfonate, alkyl phosphate, alkyl sulfate, alkyl sulfonate, and alkyl ether sulfate. Salt, alkyl sulfosuccinate, alkyl ester sulfate, alkyl benzene sulfonate, alkyl diphenyl ether disulfonate, alkyl aryl ether phosphate, alkyl aryl ether sulfate, alkyl aryl ether ester sulfate, olefin sulfonate, alkane olefin Sulfonate, polyoxyethylene alkyl ether phosphate, polyoxyethylene alkyl ether sulfate, ether carboxylate, sulfosuccinate, α-sulfo fatty acid ester , Fatty acid salts, condensates of higher fatty acid and an amino acid, a naphthenic acid salt or the like. As the cationic surfactant, an alkylamine salt, a dialkylamine salt, an aliphatic amine salt,
Examples thereof include benzalkonium salt, quaternary ammonium salt, alkylpyridinium salt, imidazolinium salt, sulfonium salt and phosphonium salt. As the nonionic surfactant, polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene glycol ester, polyoxyethylene fatty acid amide,
Polyoxyethylene fatty acid ester, polyoxyethylene polyoxypropylene glycol, glycerin ester, sorbitan ester, sucrose ester, glycerin ester polyoxyethylene ether, sorbitan ester polyoxyethylene ether, sorbitol ester polyoxyethylene ether, fatty acid alkanol Examples include amides, amine oxides, polyoxyethylene alkylamines, glycerin fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, and alkyl (poly) glycoxides. Examples of the amphoteric surfactant include imidazoline derivatives such as imidazolinium betaine, dimethylalkyllauryl betaine, alkylglycine, and alkyldi (aminoethyl) glycine. The amount of the surfactant as the dispersant added may be appropriately selected as long as the pigment is stably dispersed and the other effects of the present invention are not lost.

To the recording liquid of the present invention, conventionally known additives can be added in addition to the above coloring agent, wetting agent and surfactant. For example, a resin emulsion may be added to the aqueous recording liquid of the present invention. Resin emulsion that can be used in the present invention, the continuous phase is water,
It means an emulsion in which the dispersed phase is the following resin component. Examples of the resin component of the dispersed phase include acrylic resin, vinyl acetate resin, styrene-butadiene resin, vinyl chloride resin, acrylic-styrene resin, butadiene resin, and styrene resin. This resin is preferably a polymer having both a hydrophilic portion and a hydrophobic portion. The particle size of these resin components is not particularly limited as long as it forms an emulsion, but is preferably about 150 nm or less, more preferably about 5 to 100 nm.

These resin emulsions can be obtained by mixing resin particles with water, optionally together with a surfactant. Commercially available resin emulsions include Microgel E-1002 and E-5002.
(Styrene-acrylic resin emulsion, manufactured by Nippon Paint Co., Ltd.), Boncoat 4001 (acrylic resin emulsion, manufactured by Dainippon Ink and Chemicals, Inc.), Boncoat 5454 (styrene-acrylic resin emulsion, Dainippon Ink and Chemicals, Inc.) Made), SAE-1
014 (styrene-acrylic resin emulsion, manufactured by Zeon Corporation), Cybinol SK-200 (acrylic resin emulsion, manufactured by Saiden Chemical Co., Ltd.),
And so on. The recording liquid used in the present invention preferably contains a resin emulsion such that the resin component is 0.1 to 40% by weight of the recording liquid, and more preferably 1 to 25% by weight. The resin emulsion has the property of thickening and aggregating, has the effect of suppressing the penetration of the coloring component in the depth direction of the paper, and further has the effect of promoting fixing to the recording material. Further, depending on the type of resin emulsion, a film is formed on the recording material, which has the effect of improving the abrasion resistance of the printed matter. In addition, sodium alginate may be contained. Sodium alginate is a substance contained only in brown algae, and is a hydrophilic polyelectrolyte mainly present as a cell membrane or a cell interstitial substance. Chemically, it is a polymer of D-Mannuronic acid [M] having β-1,4 bond and L-Guluronic acid [G] having α-1,4 bond. It has thickening action, stabilizing action, dispersing action, gelling action, film forming action and the like. When added to an inkjet recording liquid, bleeding of a single color (feathering) and bleeding between different colors (color bleeding) can be improved due to viscosity change due to pH, precipitation by salts, and gelation with polyvalent cations.

As antiseptic and antifungal agents, sodium dehydroacetate, sodium sorbate, 2-pyridinethiol-1
-Sodium oxide, sodium benzoate, sodium pentachlorophenol and the like can be used in the present invention.

As the pH adjuster, any substance can be used as long as it can adjust the pH to a desired value without adversely affecting the prepared recording liquid. Examples thereof include amines such as diethanolamine and triethanolamine, hydroxides of alkali metal elements such as lithium hydroxide, sodium hydroxide and potassium hydroxide, ammonium hydroxide, quaternary ammonium hydroxide and quaternary phosphonium. Examples thereof include hydroxides, carbonates of alkali metals such as lithium carbonate, sodium carbonate and potassium carbonate. Examples of the chelating agent include sodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, and sodium uramildiacetate.

Examples of the rust preventive agent include acidic sulfite,
There are sodium thiosulfate, ammonium thiodiglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, dicyclohexylammonium nitrite and the like. In addition, a water-soluble ultraviolet absorber can be added depending on the purpose.

The recording liquid of the present invention is particularly suitable for use in an ink jet recording method for forming a color image on a recording medium by ejecting and ejecting the aqueous recording liquid as droplets from a fine ejection port. Needless to say, it can be used as a general writing instrument such as a water-based ballpoint pen, a recorder, and a recording liquid for a pen plotter.

When used in the ink jet recording method,
It is necessary to adjust the recording liquid viscosity to a desired value. Although it depends on the ejection force of the head, the viscosity of the recording liquid is generally 10 m.
It is preferably Pa · s or less. If it is larger than 10 mPa · s, it will not be possible to perform sufficient ejection with an inkjet,
Image defects often occur.

A preferable method for performing recording using the recording liquid of the present invention is to apply thermal energy corresponding to a recording signal to the recording liquid, generate droplets by the thermal energy, and form an image on the recording medium. And a method of forming.

The recording medium preferably contains pulp fibers as a main component and has a size degree of 10 s or more and an air permeability of 5 to 50 s. When printing is performed on such a recording medium with the recording liquid of the present invention, even if the recording is performed on both sides of the recording medium by the inkjet recording method, the image on the back side does not hinder the recognition of the image. The sizing degree referred to here is the Steckigt sizing degree test method for paper JIS P8.
122-76, Air Permeability The air permeability of paper and board is determined according to JIS P8117-80. When the size degree is less than 10 s, the recording liquid permeates to the back surface to cause strike-through, and when the air permeability is less than 5 s, the recording liquid permeates to the back surface to cause strike-through. Has no problem in print quality and dryness, but since the filler is added more than necessary, the cost becomes high.
In addition, when this recording medium is used in electrophotographic copying machines and printers, the filling amount is transferred to the photoconductor, fixing roller, etc., causing deterioration of image quality and failure, so it is eventually used as ink jet paper. It has to be done and it is a burden for the consumer to have to use it properly. This enables transfer paper for electrophotography, printing paper, typewriter paper,
It can be handled like various uncoated plain papers such as wire dot printer papers, word processor papers, letter papers, report papers, etc., and accordingly, the user does not have to sort the other plain papers. In terms of production, the existing paper machine can be basically used for production, and the capital investment can be minimized. Further, it can be commonly used for applications of these other recording methods. As the material of the pulp fiber used in the present invention, any type of pulp and treatment method can be appropriately used as long as it does not affect the inkjet process. In addition, non-wood pulp (kenaf, flax, bamboo, seaweed, etc.) or waste paper pulp may be used or may be mainly used. A chemical pulp represented by LBKP and NBKP is preferable. Paper making of these pulps is carried out by a conventional method using known sizing agents, fillers, and other paper making aids as necessary, as in ordinary plain paper.

As the sizing agent, rosin size and AK
D, sodium chloride, potassium chloride, styrene-maleic acid copolymer, quaternary ammonium salt, arnikelic succinic anhydride, petroleum resin-based size, epichlorohydrone, cationic starch, acrylamide and the like. As a filler,
Examples include clay, calcium carbonate, talc, titanium dioxide, synthetic silica and the like. Further, a paper strengthening agent, a yield improving agent, a fixing agent, a dye, and other papermaking auxiliary agents are added.

The recording liquid of the present invention can be applied to a high-speed recording process, which is usually difficult, because it has high permeability and gives a high-quality image without bleeding. That is, in a recording method in which a plurality of recording liquid droplets are ejected and ejected from the same or separate ejection ports to form an image on the recording medium so that at least a part of the pixel area on the recording medium overlaps, By setting the ejection time difference between two recording liquid droplets that cause overlap to be 0.125 milliseconds or less, extremely high speed recording becomes possible. In recent years, the technology for inkjet printers has made remarkable progress and the printing speed has also improved, but in order to maintain high image quality to some extent, dots in adjacent positional relationships are not formed continuously, The other ink was not landed until it penetrated into the paper. That is, while sacrificing the printing speed by a method called so-called multi-pass printing,
It can be said that high-quality printing is achieved. Since the recording liquid of the present invention exhibits extremely high penetration characteristics, it has become possible to perform high-quality printing in a single pass, which could not be achieved in the past.

[0063]

BEST MODE FOR CARRYING OUT THE INVENTION A recording liquid cartridge containing a recording liquid of the present invention and an ink jet recording apparatus equipped with the recording liquid cartridge will be described with reference to the accompanying drawings. It does not impose any limitation on the invention. FIG. 1 is a schematic front view of a mechanical portion of a serial type ink jet recording apparatus in which an ink cartridge having a recording liquid storage portion storing the recording liquid of the present invention is mounted. The mechanism portion of this ink jet recording apparatus has a main supporting guide rod (3) and a sub supporting guide rod (4) which are laterally bridged between the side plates (1) and (2) on both sides in a substantially horizontal positional relationship. The carriage unit (5) is slidably supported in the main scanning direction by the support guide rod (3) and the sub-support guide rod (4). The carriage unit (5) has yellow (Y) ink, magenta (M) ink, cyan (C) ink, and black (B) ink, respectively.
k) four heads (6) for ejecting ink respectively,
The ejection surface (nozzle surface) (6a) is mounted downward, and the heads (6) of the carriage unit (5) have four heads (6) of different colors for supplying ink to the four heads (6). Four ink cartridges (7y), (7m), (7c), and (7k), which are ink supply bodies, are replaceably mounted.

The carriage unit (5) has a drive pulley (drive timing pulley) (9) rotated by a main scanning motor (8) and a driven pulley (idler pulley) (1).
0) and a timing belt (11) which is stretched between the carriage (5) and four heads (6) in the main scanning direction by driving and controlling the main scanning motor (8). I am trying to do it. Also, the side plate (1),
On the bottom plate (12) connecting the (2), the sub-frame (1
3) and (14) are erected, and this subframe (13),
A conveyance roller (15) for feeding the paper (16) in the sub-scanning direction orthogonal to the main scanning direction is rotatably held between (14). Then, a sub-scanning motor (17) is arranged on the side of the sub-frame (14), and the sub-scanning motor (17)
A gear (18) fixed to the rotating shaft of the sub-scanning motor (17) and a gear (19) fixed to the shaft of the conveying roller (15) for transmitting the rotation of the roller to the conveying roller (15). .

Furthermore, the side plate (1) and the sub-frame (1
A reliability maintaining / restoring mechanism (hereinafter, referred to as a “subsystem”) (21) for the head (6) is arranged between the head and (3). The subsystem (21) holds four cap means (22) for capping the ejection surface of each head (6) by a holder (23), and the holder (23) can be swung by a link member (24). The carriage unit (5) abuts on the engaging portion (25) provided on the holder (23) by the movement of the carriage unit (5) in the main scanning direction. The holder (23) is lifted up, the ejection surface (6a) of the inkjet head (6) is capped by the cap means (22), and the carriage unit (5) moves to the printing area side, whereby the carriage unit (5). ), The holder (23) is lifted down to move the cap means (2).
2) is separated from the ejection surface (6a) of the inkjet head (6).

The cap means (22) is connected to the suction pump (27) through the suction tube (26), and an atmosphere opening port is formed to connect the atmosphere opening tube (26) and the atmosphere opening valve. Through the atmosphere. The suction pump (27) discharges the sucked waste liquid to a waste liquid storage tank (not shown) via a drain tube or the like. Further, a wiper blade (28), which is a wiping means made of a fibrous member for wiping the ejection surface (6a) of the inkjet head (6), a foamed member, or an elastic member such as rubber, is provided on the side of the holder (23). The blade arm (29) is attached to an arm (29), and is swingably pivotally supported so that the blade arm (29) is swung by the rotation of a cam which is rotated by a driving means (not shown).

Next, the ink cartridge (7) will be described with reference to FIGS. Here, FIG. 2 is an external perspective view of the ink cartridge before being loaded in the recording apparatus, and FIG. 3 is a front sectional view of the ink cartridge. As shown in FIG. 3, the ink cartridge (7) comprises an ink absorber (42) which absorbs ink of a desired color in a cartridge body (41). Cartridge body (4
1) is formed by adhering or welding an upper lid member (44) to the upper opening of a case (43) having a wide opening at the top, and is made of, for example, a resin molded product. The ink absorber (42) is made of a porous material such as urethane foam, and absorbs ink after being compressed and inserted into the cartridge body (41). Cartridge body (4
An ink supply port (45) for supplying ink to the recording head (6) is formed at the bottom of the case (43) of 1), and a seal ring (4) is formed on the inner peripheral surface of the ink supply port (45).
6) is fitted. Further, the upper lid member (44) is formed with an atmosphere opening port (47). Then, in the cartridge main body (41), in the state before loading, the ink supply port (4
5) The cap member is provided to prevent the ink inside from leaking due to the case (43) being compressed and deformed by the pressure applied to the wide side wall at the time of closing the cartridge 5) at the time of loading or transporting the cartridge, or at the time of vacuum packaging. Wearing (50).

As shown in FIG. 2, the atmosphere opening port (47) is sealed by attaching a film-like sealing member (55) having an oxygen permeability of 100 ml / m ² or more to the upper lid member (44). ing. The seal member (55) is provided with a plurality of grooves (48) formed around the atmosphere opening port (47).
It is also sized to seal even. In this manner, by sealing the atmosphere opening port (47) with the sealing member (55) having an oxygen permeability of 100 ml / m ² or more, the ink cartridge (7) is used as a packaging member such as an aluminum laminate film having no air permeability. When the ink is packed in a reduced pressure state, gas is contained in the ink due to the atmosphere in the space (A) (see FIG. 3) generated when the ink is filled and between the ink absorber (42) and the cartridge body (41). Even when dissolved, the air in the ink is discharged through the seal member (55) to the space between the cartridge body (41) having a high degree of vacuum and the packaging member, and the degassing degree of the ink is improved.

FIG. 4 shows an example of the structure of a recording unit having a recording liquid container containing the recording liquid of the present invention and a head part for ejecting recording droplets. That is, the recording unit (30) is of a serial type, and includes an inkjet head (33), an ink tank (49) for containing a recording liquid supplied to the inkjet head (33), and the ink tank (49). )
A main part is constituted by a lid member (44) for sealing the inside.
The inkjet head (33) has a large number of nozzles (32) for ejecting a recording liquid. The recording liquid is guided from the ink tank (49) to the common liquid chamber (not shown) through the ink supply pipe (not shown), and the nozzle is generated according to the electric signal from the recording apparatus main body input from the electrode (31). It is discharged from (32). Such a type of recording unit has a structure that is often used for a head of a type that can be manufactured at low cost due to its structure, that is, a so-called thermal type or bubble type head that uses thermal energy as a driving power source. The recording liquid of the present invention improves the wettability to the thermal element by adding the component (A) in a recording method such as a bubble method or a thermal method.
Ejection stability and frequency stability are obtained even with a small amount of addition, and safety is high, which is very suitable.

Here, the serial type ink jet recording apparatus as described above has been described. However, the recording liquid of the present invention has the nozzles in an arbitrary arrangement such as a staggered pattern, and has the same resolution as a target image or a fraction thereof. It is also possible to apply the present invention to a recording apparatus having a so-called line head, which is integrated in the density of 1 and is arranged over the width of the recording medium. Further, the recording device mentioned here may be not only an output printer for a PC or a digital camera, but also a device having a composite function in combination with a fax, a scanner, a telephone or the like.

[0071]

EXAMPLES Examples and comparative examples of the present invention will be shown below, but the present invention is not limited thereto. In addition,
The amount (%) of each component described in the examples is based on weight.

Example 1 After mixing and stirring with the following ink formulation, the pH was adjusted to 8 with a 10% aqueous solution of lithium hydroxide. Then, filtration was performed with a membrane filter having an average pore size of 0.1 μm to obtain an ink composition. Ink composition 1 C.I. I. Direct Black 168 4% by weight Glycerin 5% by weight Ethylene glycol 5% by weight Compound (1-7) 0.3% by weight Compound (2-3) 0.7% by weight Ion-exchanged water Remaining amount

(Example 2) An ink composition was prepared in the same manner as in Example 1 except that the following composition was used (sodium hydroxide was used to adjust the pH to 7.5). Composition 2 CI Direct Yellow 142 3.0% by weight Thiodiglycol 8% by weight Compound (1-4) 0.5% by weight Compound (2-4) 0.5% by weight 2,2,4-trimethyl -1,3-Pentanediol 2 wt% Ion-exchanged water Remaining amount

Example 3 After mixing and stirring with the following formulation, the pH was adjusted to 8 with a 10% aqueous solution of lithium hydroxide. Then, filtration was performed with a membrane filter having an average pore size of 0.8 μm to obtain an ink composition. Ink composition 3 CAB-O-JET 200 (sulfone group addition type) 15% by weight Diethylene glycol 6.5% by weight Glycerin 3.5% by weight Compound (1-5) 1.2% by weight Compound (2-2) 0. 8% by weight 2-ethyl-1,3-hexanediol 3% by weight 2-pyrrolidone 2% by weight Ion-exchanged water Remaining amount

Example 4 First, the color pigments shown below were dispersed using a bead mill in the following dispersion formulation.
The resulting aqueous dispersion was mixed and stirred with the following ink formulation, and then adjusted to a pH of 8 with a 10% aqueous lithium hydroxide solution. Then, filtration was performed with a membrane filter having an average pore size of 0.8 μm to obtain an ink composition. Pigment dispersion 1 C.I. I. Pigment Yellow 13 (average particle size 117 nm) 15% by weight styrene-acrylate-methacrylic acid diethanolamine salt copolymer 3% by weight ion-exchanged water residual ink composition 4 pigment dispersion 1 33.3% by weight glycerin 5% by weight diethylene glycol 10 Wt% Compound (1-8) 1.0 wt% Compound (2-7) 1.0 wt% 2-pyrrolidone 2 wt% Ion-exchanged water Remaining amount

(Example 5) In the same manner as in Example 4, first, color pigments were dispersed using a bead mill in the following dispersion formulation. After mixing the resulting aqueous dispersion with the following ink formulation and stirring, 10% lithium hydroxide was added to adjust the pH to 8.
It was adjusted with an aqueous solution. Then, filtration was performed with a membrane filter having an average pore size of 0.8 μm to obtain an ink composition. Pigment dispersion 2 C.I. I. Pigment Yellow 13 (average particle size 117 nm) 15% by weight styrene-acrylate-methacrylic acid diethanolamine salt copolymer 3% by weight ion-exchanged water residual ink composition 5 pigment dispersion 2 33.3% by weight glycerin 5% by weight diethylene glycol 10 Wt% Compound (1-8) 1.0 wt% Compound (2-7) 1.0 wt% 2-Ethyl-1,3-hexanediol 3 wt% 2-Pyrrolidone 2 wt% Ion-exchanged water Remaining amount

Example 6 Pigment Dispersion Liquid 3 was prepared in the same manner as in Example 4 except that the following composition was used, and an ink composition 6 was obtained. Pigment dispersion 3 C.I. I. Pigment Blue 15: 3 (average particle size 123 nm) 15% by weight Styrene-acrylate-methacrylic acid diethanolamine salt copolymer 3% by weight Ion-exchanged water Remaining ink composition 6 Pigment dispersion 3 33.3% by weight Glycerin 3% by weight 1,5-Pentanediol 15% by weight Compound (1-10) 0.3% by weight Compound (2-3) 1.2% by weight 2,2,4-Trimethyl-1,3-pentanediol 5% by weight 2- Pyrrolidone 2% by weight Ion-exchanged water Remaining amount

Example 7 A pigment dispersion 7 was prepared in the same manner as in Example 4 except that the following composition was used, and an ink composition 6 was obtained by using the pigment dispersion 7. Pigment dispersion 4 C.I. I. Pigment Red 122 20% by weight Octylpropenylphenol Ethyleneoxide 50 mol Adduct 15% by weight Ethylene glycol 30% by weight Ion-exchanged water Remaining ink composition 7 Pigment dispersion 4 33.3% by weight Polyethylene glycol (molecular weight 200) 10% by weight % Compound (1-9) 0.4% by weight Compound (2-1) 1.6% by weight 2,2,4-trimethyl-1,3-pentanediol 1% by weight 2-pyrrolidone 2% by weight Ion-exchanged water residue amount

(Comparative Example 1) In Example 1, the compound (1-7) was not added.

(Comparative Example 2) In Example 1, the compound (2-3) was not added.

(Comparative Example 3) In Example 2, the compound (1-4) was not added.

(Comparative Example 4) In Example 2, the compound (2-4) was not added.

(Comparative Example 5) In Example 3, the compound (1-5) was not added.

(Comparative Example 6) In Example 3, the compound (2-2) was not added.

(Comparative Example 7) In Example 4, the compound (1-8) was not added.

(Comparative Example 8) In Example 4, the compound (2-7) was not added.

(Comparative Example 9) In Example 5, the compound (1-8) was not added.

(Comparative Example 10) In Example 5, the compound (2-7) was not added.

(Comparative Example 11) In Example 6, the compound (1-10) was not added.

(Comparative Example 12) In Example 6, the compound (2-3) was not added.

(Comparative Example 13) In Example 7, the compound (1-9) was not added.

(Comparative Example 14) In Example 7, the compound (2-1) was not added.

(Comparative Example 15) In Example 7, the compound (1-9) and the compound (2-1) were not added.

Next, the following tests were conducted on the inks described in the above Examples and Comparative Examples. The evaluation device has a plurality of nozzles, and the ejection amount per droplet from each nozzle is 2
Each of the following items was evaluated using a piezo-type inkjet printer that discharges at 3 pl, and has a so-called droplet passing density of 600 dpi in the most dense state, and the results are shown in Table 1. As the target paper, ordinary PPC paper, bond paper, and recycled paper were used.

1) Image Sharpness (Ink Penetration) A test pattern was printed, and the following five grades were evaluated based on character blurring, color boundary blurring and image density. X: Bleeding of characters and color boundaries are large, and image density is low. Δ: Character blurring, color boundary blurring is large, but image density is high ○: Character blurring, color boundary blurring is small, but image density is low ◎: Character blurring, color boundary blurring is small, and image density is high

2) Ejection stability After the carriage was scanned (empty scan) in a state where ejection was not performed for 60 seconds, 20 drops were printed for each nozzle,
After that, the evaluation of performing the recovery operation (purge 50 drops) was repeated 10 times and compared with the case of continuous printing. The evaluation was made visually by taking a magnified photograph of the dot density of the first drop and the dot ejection direction during printing of 20 drops. The judgment criteria are as shown below.

Regarding the dot density of the first drop, XX: No dot ejection is seen, or dots cannot be confirmed due to transparency. X: Dot density is increased and the pixel diameter is reduced. △: Dotted and unclear dot outline ○: Dot outline is clear, but the color tone is different from the second drop ◎: High density, clear dot outline

Regarding the dot ejection direction, x: the first ejection dot exceeds the line of the second ejection dot. Δ: The ejection direction is slightly disturbed, but it extends to the second ejection row. No ○: No disturbance in the ejection direction, the nozzles are arranged in almost one row

3) Storage stability The following storage test was carried out on the ink sample, and it was judged from changes in average particle diameter and viscosity before and after storage. 5 cycles of heat cycle of storage at 70 ° C. for 10 days, storage at −20 ° C. for 24 hours, and storage at 50 ° C. for 24 hours 5: Judgment criteria ×: Large increase in particle size and viscosity, no fluidity Δ: Particle size, viscosity However, there is almost no change in particle size and viscosity. The above results are shown in Table 1.

[0100]

[Table 1] Discharge stability (direction) is not evaluated when no discharge is performed (indicated by ----)

[0101]

As is apparent from the detailed and specific description above, according to claim 1 of the present invention, an aqueous recording liquid having excellent permeability can be provided without impairing ejection stability and storage stability. According to claims 2 and 3, it is possible to improve the permeability, and according to claim 4, the permeability is improved without impairing ejection stability and storage stability. According to claims 5 to 8, the permeability is further improved. According to claims 9 to 11, a color aqueous recording liquid having a particularly large effect on a pigment and having excellent penetrability without impairing ejection stability and storage stability can be provided. A recording method capable of printing can be provided, and according to claims 13 and 14, an ink cartridge excellent in ejection stability and storage stability can be provided.
5 has an extremely excellent effect that an inkjet recording device capable of high-speed printing can be provided.

[Brief description of drawings]

FIG. 1 is a schematic front view showing a configuration example of a serial type ink jet recording apparatus equipped with an ink cartridge containing a recording liquid of the present invention.

FIG. 2 is an external perspective view of an ink cartridge before being loaded in the recording apparatus according to the present invention.

FIG. 3 is a front sectional view of an ink cartridge according to the present invention.

FIG. 4 is an external perspective view of a recording unit integrated with the recording head of the present invention.

[Explanation of symbols]

1 side plate 2 side plates 3 Main support guide rod 4 Secondary support guide rod 5 Carriage unit 6 heads 6a Discharge surface (nozzle surface) 7 ink cartridges 7c Cyan ink cartridge 7k black ink cartridge 7m magenta ink cartridge 7y yellow ink cartridge 8 Main scanning motor 9 Drive pulley (drive timing pulley) 10 Driven pulley (idler pulley) 11 Timing belt 12 Bottom plate 13 subframes 14 subframes 15 Conveyor roller 16 sheets 17 Sub-scanning motor 18 gears 19 gears 21 Reliability maintenance and recovery mechanism (subsystem) 22 Cap means 23 Holder 24 Ring member 25 Engagement part 26 Suction tube 27 Suction pump 28 Wiper blade 29 blade arm 30 recording units 31 electrodes 32 nozzles 33 heads 41 Cartridge body 42 ink absorber 43 cases 44 Upper lid member 45 ink supply port 46 seal ring 47 Atmosphere opening 48 grooves 49 ink tank 50 Cap member 55 Seal member A space

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Nobuyo Nagai             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh F-term (reference) 2C056 EA05 FC01 FC02                 2H086 BA01 BA53 BA55 BA59                 4J039 AE07 BC07 BC09 BC12 BC27                       BE01 BE02 BE12 BE22 CA03                       CA06 EA42 EA44 EA46 GA24

Claims (15)

[Claims] 1. A water-based ink for ink-jet recording containing a colorant which is dispersed or dissolved in water, which contains a polyoxyethylene alkyl ether-based surfactant and a polyoxyethylene alkyl ether acetate-based surfactant. Characteristic water-based ink for ink-jet recording. 2. The aqueous ink for inkjet recording according to claim 1, wherein the polyoxyethylene alkyl ether-based surfactant is represented by the following general formula (1). Embedded image R ₁ O (CH ₂ CH ₂ O) pH (1) (In the formula (1), R ₁ is an optionally branched alkyl group having 8 to 14 carbon atoms. P is 1 to 30. Represents an integer.) 3. R in the structure represented by the above general formula (1)
_The water-based ink for inkjet recording according to claim 2, wherein the alkyl group of ₁ has a branched structure. 4. The water-based ink for inkjet recording according to claim 2, wherein the polyoxyethylene alkyl ether acetate-based surfactant is represented by the following general formula (2). [Chemical 2] (In the formula (2), R ₂ is an alkyl group having 8 to 14 carbon atoms which may be branched. Q is an integer of 3 to 12, M is an alkali metal ion, quaternary ammonium, quaternary phosphonium, or alkanol. Represents an amine.) 5. The inkjet recording according to claim 1, further comprising a polyol having a solubility in water at 20 ° C. of 0.2% by weight or more and less than 4.5% by weight in addition to the contained components. Water-based ink for use. 6. The water-based ink for ink jet recording according to claim 5, wherein the polyol is 1,3-diol represented by the following general formula (3). [Chemical 3] (In the formula (3), R ₁ and R ₂ are hydrogen or an alkyl group, and R ₃ is an alkyl group. R ₁ and R ₂ are not hydrogen at the same time, and R ₁ , R ₂ and R ₃ (The total carbon number is 3-9) 7. The 1,3-diol is 2-ethyl-1,3.
A water-based ink for inkjet recording according to claim 6, which is hexanediol. 8. The water-based inkjet recording ink according to claim 6, wherein the 1,3 diol is 2,2,4-trimethyl-1,3-pentanediol. 9. The aqueous ink for inkjet recording according to claim 1, wherein the colorant is a pigment. 10. The water-based inkjet recording ink according to claim 9, wherein the pigment is dispersed with a surfactant. 11. The water-based ink for ink jet recording according to claim 9, wherein the pigment is dispersed with a polymer dispersant. 12. A recording method comprising forming an image on a recording medium by ejecting and ejecting the aqueous ink for inkjet recording according to any one of claims 1 to 11 as droplets from a fine ejection port. 13. An ink cartridge comprising an ink containing portion containing ink, wherein the ink is
13. An ink cartridge, which is the water-based ink for inkjet recording according to any one of 1 to 11. 14. The ink according to claim 1, wherein the water-based ink for inkjet recording is an ink cartridge including an ink containing portion containing ink and a head portion for ejecting ink droplets. An ink cartridge characterized in that 15. An ink jet recording apparatus comprising an ink cartridge having an ink containing portion containing ink and a recording head for ejecting recording droplets, or an ink containing portion containing ink, and ink droplets. An ink jet recording apparatus provided with an ink cartridge having a recording head for ejecting ink.
An ink jet recording apparatus comprising the ink cartridge described in 3 or 14.