JPH0616982A - Water based ink - Google Patents

Abstract

(57) [Summary] [Purpose] It is suitable for inkjet recording, especially for color printing on plain paper. To provide a water-based cyan ink which is excellent in drying property and has little deterioration in image quality. [Composition] Surface tension of 50 mJ by addition of surfactant
/ M ² or less, and by incorporating a phthalocyanine dye having an alkyl group or an aryl group introduced therein as a water-soluble dye, the alkyl group or the aryl group interacts with a surfactant to have excellent penetrability and to prevent bleeding. It is a water-based cyan ink that is hard to generate.

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 suitable for ink jet recording, and more particularly to a water-based ink composition exhibiting excellent properties as a color ink for so-called plain paper. The water-based ink for water-based writing instruments, recorders and pen plotters. It is also used as.

[0002]

2. Description of the Related Art In recent years, ink jet printers have become popular due to their advantages of low noise and low running cost, and color printers capable of printing on plain paper have been put on the market. However, image color reproducibility, water resistance, light resistance,
It is difficult to satisfy all of the image dryness, image blurring, 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 two-color overlapping portion of red, green, and blue. In particular, when drying is carried out without using a fixing device, as described in JP-A-55-29546, the drying property is improved by increasing the penetrability by adding a surfactant, so that the paper remarkably bleeds. Further, Japanese Patent Laid-Open No. 56-57862 discloses an ink to which a strong basic substance is added, but it is effective for rosin-sized acidic paper, but is not effective for paper using alkyl ketene dimer as a sizing agent. has no effect.

Particularly, a dye usually used in cyan ink is C.I. which is a phthalocyanine derivative. I. In Acid Blue 249 and Direct Blue 86, 87, 199, there has been a problem that bleeding remarkably occurs depending on the paper type when the permeability is increased by a surfactant.

Further, a phthalocyanine dye in which an alkyl chain is introduced for the purpose of improving the water resistance of these conventional dyes is disclosed in JP-B-63-18981 and JP-A-62-149.
Although disclosed in Japanese Patent No. 758, no consideration has been given to improving the drying property of plain paper.
In addition, the reliability is not sufficient so that it is not used yet.

[0005]

SUMMARY OF THE INVENTION A first object of the present invention is to provide an aqueous cyan ink recording composition which satisfies various characteristics as an ink jet ink, is excellent in drying property and has improved image quality deterioration. is there.

A second object of the present invention is to clarify the structure of a phthalocyanine dye that is effectively used in the ink composition, and to provide a water-based cyan ink composition having improved drying properties and less image bleeding.

A third object of the present invention is to provide a cyan ink having excellent storage stability and jetting stability.

A fourth object of the present invention is to provide a water-based ink composition which improves the drying property by using a conventionally known dye in combination and has less image bleeding.

[0009]

The constitution of the present invention for solving the above-mentioned problems is an aqueous ink as described in the claims.

That is, in the present invention, the surface tension is increased to 50 mJ / m by adding a surfactant for the purpose of enhancing the penetrability into paper.
² or less, by incorporating a phthalocyanine dye having an alkyl group or an aryl group introduced as a water-soluble dye, the alkyl chain or aryl group of the dye interacts with a surfactant, so that bleeding can be achieved even if the permeability is improved. The present invention has been completed by finding that it is hard to generate. As the dye having an alkyl chain or an aryl group introduced therein, the one having an alkyl group introduced via a sulfonamide represented by the following general formula (I) is excellent in terms of heat stability of the dye. I found that. On the other hand, the same bleeding-preventing effect can be observed even in the case of introducing an alkyl group or the like with a sulfonic acid ester, but the thermal stability and the like are poor.

General formula

[0012]

[Chemical 3]

M: Cu, Ni Pc: represents a phthalocyanine skeleton.

R ₁ and R ₂ : any one of hydrogen, an alkyl group, an alkyl ether group, an aralkyl group, an aryl group and a hydroxyalkyl group.

X: alkali metal, quaternary ammonium,
Any of the quaternary phosphoniums.

M, n: m is 1 to 2, n is 1 to 3 and 2≤m
+ N ≦ 4 is satisfied.

Further, the phthalocyanine dye (I) of the present invention
It was found that excellent solubility stability is exhibited by using lithium ion as the counter ion of, and quaternary ammonium and quaternary phosphonium represented by the following general formula.

General formula

[0019]

[Chemical 4]

(Y: nitrogen or phosphorus, R _{3 to} R ₆ : alkyl group having 1 to 4 carbon atoms, hydroxylalkyl group, halogenated alkyl group) C.I. which is a conventionally known commercially available phthalocyanine dye.
I. Acid Blue 249, Direct Blue 86, 8
It was found that by mixing 7, 199 and the water-soluble phthalocyanine dye of the above general formula (I), bleeding is unlikely to occur even if the permeability is increased by a surfactant.

The total content of these dyes is 0.1 to 10% by weight, preferably 0.5 to 5% by weight in the ink. If it is less than 0.1% by weight, the concentration cannot be obtained, and if it exceeds 10% by weight, the reliability cannot be obtained. The mixing ratio of the conventionally known commercially available dye and the dye of the general formula (I) varies depending on the combination of the dyes, but preferably 50% or more of the dye is the dye of the general formula (I).

The dye of the general formula (I) can be obtained by chlorsulfolating a phthalocyanine pigment and then reacting the corresponding amine derivative under alkaline conditions, which will be specifically shown below. The free acid type is shown here.

[0023]

[Chemical 5]

[0024]

[Chemical 6]

[0025]

[Chemical 7]

The dye of the general formula (I) can be easily converted into an alkali salt by adding an alkali hydroxide containing a desired alkali ion when the dye is dissolved in water at the time of ink preparation. For example, in the case of a lithium salt, it can be performed by adding lithium hydroxide, and regarding the quaternary ammonium and phosphonium of the general formula (II), specifically, the following hydroxides can be added.

[0027]

[Chemical 8]

[0028]

[Chemical 9]

In the present invention, the counterions of the water-soluble dye (I) do not have to be all sodium, lithium and / or the compound of the above general formula (II), and may be mixed with other alkali ions. it can. Other preferred counterions are triethanolamine and the like. The amount of ions of sodium, lithium and / or the compound of the general formula (II) is preferably 30% or more, more preferably 50% or more based on the number of moles of the hydrophilic dye.

As the surfactant used in the present invention, in the anionic system, fatty acid monocarboxylic acid salts such as sodium laurate, alkylbenzene sulfonic acid salts such as dodecylbenzenesulfonic acid, sodium 2-ethylhexyl sulfosuccinate are used. And the like, sulfosuccinic acid dialkylesters, dodecyl sodium sulfate and other sulfate alkyl salts, dodecyl polyoxyethylene sulfate and other sulfate alkyl polyoxyethylene salts, monolauryl sodium phosphate and other phosphate salts, and the like. Examples of nonionic surfactants include glycerin fatty acid esters such as glycerin monostearate, sorbitan fatty acid esters (Span) such as sorbitan stearate, sucrose fatty acid esters such as sucrose stearate, and polyoxyethylene nonyl. Polyoxyethylene nonylphenyl ether (NP) such as phenyl ether, polyoxyethylene alkyl ethers such as dodecyl polyoxyethylene ether, polyoxyethylene polyoxypropylene block copolymer, polyoxyethylene glycol such as polyoxyethylene glycol oleic acid ester Fatty acid esters, polyoxyethylene sorbitan monopalmitate esters and other polyoxyethylene sorbitan fatty acid esters, lauric acid dietano Ruamido, and the like can be mentioned. As the amphoteric surfactant, N, such as lauryl dimethyl acetic acid betaine,
Examples thereof include 2-alkyl-1-hydroxyethyl-1-carboxymethylimidazolinium betaines such as N-dimethyl-N-alkylaminobetaines and 2-undecyl-N-carboxymethyl-N-hydroxyethylimidazolium betaine. Further, a silicone type surfactant and a fluorine type surfactant are also effective.

The amount of these additives added varies depending on the critical micelle concentration of each surfactant, but is usually 0.1 to 10% by weight, more preferably 0.5 to 5% by weight.

As penetrants added together with these surfactants for the purpose of adjusting the surface tension, diethylene glycol monophenyl ether, ethylene glycol monophenyl ether, ethylene glycol monoallyl ether, diethylene glycol monophenyl ether,
Alkyl and aryl ethers of polyhydric alcohols such as diethylene glycol monobutyl ether, propylene glycol monobutyl ether and tetraethylene glycol chlorophenyl ether, lower alcohols such as ethanol and 2-propanol are mentioned, but diethylene glycol monobutyl ether is particularly preferable. .

The surface tension in the present invention is an index showing the penetrability into paper, and particularly shows the dynamic surface tension in a short time of 1 second or less after the surface is formed, and the static surface tension measured at the saturation time. Is different. As a measuring method, JP-A-63-312
Although any method can be used as long as it can measure the dynamic surface tension of 1 second or less by the conventionally known method described in Japanese Patent No. 37, etc., in the present invention, it was measured using a Wilhelmy type hanging plate type surface tension meter. The value is preferably from 50 mJ / m ² or less surface tension, and more preferably dry can be obtained and excellent and 40 mJ / m ² or less.

The ink of the present invention uses water as a liquid medium, but in order to make the ink have desired physical properties, to prevent the ink from drying, and to improve the dissolution stability of the compound of the present invention. The following water-soluble organic solvents can be used for the purpose of, for example, Polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, hexamethylene glycol, glycerol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether ,
Polyhydric alcohol alkyl ethers such as tetraethylene glycol monomethyl ether and propylene glycol monoethyl ether, polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether; N-methyl-2
-Pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethylimidazolidinone, ε-caprolactam, γ-butyrolactone and other nitrogen-containing heterocyclic compounds; formamide, N-methylformamide, N, N-
Amides such as dimethylformamide; amines such as monoethanolamine, diethanolamine, triethanolamine, monoethylamine, diethylamine and triethylamine, sulfur-containing compounds such as dimethyl sulfoxide, sulfolane and thiodiethanol, propylene carbonate, ethylene carbonate and the like. . These solvents may be used alone or in combination with water.

Among these, particularly preferable are diethylene glycol, thiodiethanol, polyethylene glycol 200 to 600, triethylene glycol, glycerol, and N-methyl-2-pyrrolidone. By using these, high solubility of the present compound and An excellent effect can be obtained for preventing defective injection characteristics due to water evaporation.

To the ink of the present invention, conventionally known additives can be added in addition to the above dye and solvent.

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

As the pH adjustor, any substance can be used as long as it can adjust the pH to 7 or more without adversely affecting the ink to be prepared.

As examples thereof, 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 Examples thereof include quaternary phosphonium hydroxide, 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.

A water-soluble ultraviolet absorber, a water-soluble infrared absorber and a surfactant may be added depending on the purpose.

[0043]

EXAMPLES Examples and comparative examples of the present invention will be shown below.
In addition, the amount (%) of each component described in the examples is based on weight.

Example 1 A composition having the following formulation was dissolved by stirring at 60 ° C., allowed to cool at room temperature, and then adjusted to pH 8 with a 10% aqueous solution of lithium hydroxide, which was adjusted to 0.22 μm. Ink 1 was prepared by filtering with a Teflon filter.

Dye of Specific Example (1) 1% Glycerol 5% Diethylene glycol 10% Triton X-100 (manufactured by Wako Pure Chemical Industries, Ltd., polyoxyethylene (10) octylphenyl ether) 1% Sodium dehydroacetate 0.2% Ion-exchanged water residue Amount Example 2 Ink 2 was prepared in the same manner as in Example 1 except that the following composition was used, and the pH was adjusted to 9 with sodium hydroxide.

Dye of Specific Example (2) 1.5% Diethylene glycol 8% Glycerin 2% Diethylene glycol monobutyl ether 2% BT7 (manufactured by Nikko Chemical Co., polyoxyethylene (7) alkyl ether) 1% Specific example (II-1) 25 % Aqueous solution 1.8% 2-Pyridinethiol-1-oxide sodium 0.2% Ion-exchanged water Remaining amount Example 3 pH was set in the same manner as in Example 1 except that the following composition was used.
Was made 9 with lithium hydroxide to prepare Ink 3.

Dye of Specific Example (3) 1.8% N-Methyl-2-pyrrolidone 5% Glycerol 2% Propylene glycol monobutyl ether 5% BT12 (manufactured by Nikko Chemical, polyoxyethylene (12) alkyl ether) 1% Specific Example (II-3) 25% Aqueous Solution 2% Sodium Dehydroacetate 0.2% Ion-exchanged Water Remaining Example 4 The same procedure as in Example 1 was repeated except that the following composition was used.
Was made 9 with lithium hydroxide to prepare Ink 4.

Dye of Specific Example (4) 1.5% Ethylene Glycol 5% Glycerol 2% SH3746 (Toray Dow Corning Silicone, a polyoxy ethylene chain-containing silicone surfactant) 1% Specific Example (II-4) 25 % Aqueous solution 2% sodium benzoate 0.2% ion-exchanged water residual amount Example 5 The same procedure as in Example 1 was repeated except that the following composition was used.
Was made 9 with sodium hydroxide to prepare an ink 5.

Dye of Specific Example (5) 1% Triethylene glycol 5% Glycerol 2% Fluorosurfactant FC430 (Sumitomo 3M) 0.2% BT12 1% Specific Example (II-2) 25% aqueous solution 1. 5% ion-exchanged water Remaining amount Example 6 The pH was the same as in Example 1 except that the following composition was used.
Was made 8 with lithium hydroxide to prepare an ink 6.

Dye of Specific Example (7) 1.5% Propylene Glycol 8% Hexamethylene Glycol 5% Aerosol OT (Dialkyl sulfosuccinate) 1% Specific Example (II-7) 25% Aqueous solution 2% Ion-exchanged water residue Amount Example 7 The pH was the same as in Example 1 except that the following composition was used.
Was made 9 with lithium hydroxide to prepare Ink 7.

Dye of Specific Example (9) 1.8% N-methyl-2-pyrrolidone 8% Glycerin 5% Ethylene glycol monophenyl ether 2% Dodecyl sulfate sodium salt 1% Sodium benzoate 0.1% Ion-exchanged water residue Amount Example 8 The same procedure as in Example 1 was repeated except that the following composition was used.
Was made 8 with sodium hydroxide to obtain Ink 8.

Dye of Specific Example (11) 1.8% Thiodiethanol 5% Diethylene glycol 10% Sodium dodecylbenzenesulfonate 1% Ion-exchanged water Remaining Example 9 The same as Example 1 except that the following composition was used. , PH
Was made 8 with lithium hydroxide to obtain Ink 9.

Dye of Specific Example (1) 0.8% C.I. I. Direct Blue 199 0.4% Glycerol 5% Diethylene glycol 10% Triton X-100 (manufactured by Wako Pure Chemical Industries, Ltd., polyoxyethylene (10) octylphenyl ether) 1% Sodium dehydroacetate 0.2% Ion-exchanged water Remaining amount Example 10 below The pH was the same as in Example 1 except that the composition was used.
Was made 8 with lithium hydroxide to obtain Ink 9.

Dye of Specific Example (7) 0.8% C.I. I. Acid Blue 249 0.5% Diethylene glycol 10% Glycerin 4% Aerosol OT 1% Sodium dehydroacetate 0.2% Ion-exchanged water Remaining Comparative Example 1 In Example 1, the dye of Specific Example (1) was replaced with C.I. I.
Ink 11 was prepared in the same manner except that Direct Blue 199 was used.

COMPARATIVE EXAMPLE 2 In Example 2, C.I. I.
Ink 1 in the same manner except that Acid Blue 249 was used.
It was set to 2.

Reference Example 1 Ink 13 was prepared in the same manner as in Example 3 except that the specific example (II-3) 25% aqueous solution was replaced with potassium hydroxide to adjust the pH to 9.

[0057]

[Test Results] Next, Examples 1 to 10 and Comparative Example 1,
The following tests were carried out for 2 and Reference Example 1.

1) Image sharpness 300 dp of the thermal ink jet system shown in FIG.
Inkjet printer with i nozzle and FIG.
The laminated PZT shown in Fig. 3 was used to pressurize the liquid chamber channel.
The thermal inkjet printer shown in FIG. 1, which performs printing with an inkjet printer having a nozzle of dpi and visually judges image bleeding, color tone, and density, has an ink discharge nozzle 1, a heating element 2, a substrate 3, a nozzle plate 4, The ink jet printer having the ink liquid chamber 5 and the ink supply pipe 6 and using the laminated PZT shown in FIG. 2 has an ink discharge nozzle 1, a substrate 3, a nozzle plate 4, a common liquid chamber 7, a laminated PZT 8, and a flow path plate. 9 and the flow path 10.

Printing paper was printed on three kinds of commercially available recycled paper, high-quality paper and bond paper.

2) Image Drying Property A filter paper was pressed against the image after printing under a certain condition, and the time until the ink was not transferred to the filter paper was measured. When any of the papers dried within 5 seconds, it was judged as ◯.

3) Water resistance of image The image sample was immersed in water at 30 ° C. for 1 minute, the change in image density before and after immersion was measured by a Macbeth densitometer, and the water resistance (fading rate%) was calculated by the following formula. I asked.

[0062]

[Equation 1]

4) Storage stability Each ink was put in a polyethylene container and stored at -20 ° C, 5 ° C.
It was stored at 20 ° C. and 70 ° C. under each condition for 3 months, and the surface tension after storage, the viscosity, and the presence or absence of precipitation were examined. The product with no change in physical properties under any conditions was rated as ◯.

5) Reliability at the time of printing suspension It is checked how long the printing can be resumed without the cap, cleaning, etc. during operation of the printer having the head shown in FIG. The results of evaluation of the reliability are shown in the table depending on whether the ejection direction shifts or the weight of the ejected droplet changes.

6) Surface tension The following shows the results of determining the dynamic surface tension after 1 second by measuring the time change of the surface tension of each ink with a Wilhelmy hanging plate type surface tensiometer.

[0066]

[Table 1]

[0067]

From the above results, according to the water-based ink of the present invention, the dynamic surface tension of 50 mJ / m ² is increased by the surfactant.
By using the phthalocyanine dye having an alkyl chain or an aryl group introduced therein, it is possible to prevent deterioration of the image quality due to the improvement of the penetration speed in the cyan ink having the improved ink permeability.

Further, according to the present invention, an ink having a fast drying rate and less bleeding, which can be sufficiently used even in a thermal ink jet method, is provided by revealing a particularly thermally stable dye structure of the cyan dye. You can

Furthermore, by selecting the counter ion of the water-soluble dye, it is possible to provide a water-based ink having excellent storage stability and jetting stability.

According to the present invention, conventionally known acidic and direct cyan dyes can be used in combination to provide an ink having less image bleeding and an excellent drying rate.

It is possible to improve water resistance.

Further, according to the present invention, by setting the pH of the ink to 7 or more, it is possible to provide a water-based ink which is stable when the ink is stored and has an excellent image quality improving effect after printing.

With these, the present invention can provide a recording method for forming an excellent color image on plain paper.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of the structure of a thermal inkjet printer suitable for using the ink of the present invention.

FIG. 2 is a schematic diagram showing an example of the structure of an inkjet printer that is also suitable for using the ink of the present invention and uses a laminated PZT for pressurizing a liquid chamber flow path.

[Explanation of symbols]

 1 Ink Discharge Nozzle 2 Heating Element 3 Substrate 4 Nozzle Plate 5 Ink Liquid Chamber 6 Ink Supply Pipe 7 Common Liquid Chamber 8 Laminated PZT 9 Channel Plate 10 Channel

Claims (4)

[Claims] 1. A water-based ink containing a water-soluble dye, water and a wetting agent, the surface tension of which is 50 mJ / m ² or less, and at least one of the water-soluble dyes is a water-soluble phthalocyanine having an alkyl group or an aryl group. A water-based ink characterized by being a dye. 2. The water-soluble phthalocyanine dye is represented by the following general formula (I).
The water-based ink described. General formula: However, in the said General formula (I), it shows M: Cu, NiPc: phthalocyanine skeleton. R ₁ and R ₂ : either hydrogen, an alkyl group, an alkyl ether group, an aralkyl group, an aryl group or a hydroxyalkyl group. X: Any of alkali metal, quaternary ammonium, and quaternary phosphonium. m, n: m is 1 to 2 and n is 1 to 3, satisfying 2 ≦ m + n ≦ 4. 3. The counter ion X in the general formula (I) is sodium, lithium, or any one of quaternary ammonium and quaternary phosphonium represented by the following general formula (II). The water-based ink according to claim 2. General formula: However, in the general formula (II), Y is nitrogen or phosphorus R _{3 to} R ₆ is any one of an alkyl group having 1 to 4 carbon atoms, a hydroxylalkyl group, and a halogenated alkyl group. 4. A C.I. together with a water-soluble phthalocyanine dye.
I. Acid Blue 249, C.I. I. The water-based ink according to any one of claims 1 to 3, which contains at least one dye selected from Direct Blue 86, 87, and 199.