JPH10114877A - Ink jet recording fluid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ink jet recording fluid which is improved in storage stability, fungus resistance, etc., is free from nozzle clogging and can give prints improved in water resistance, light resistance and color reproducibility by mixing a specified water-soluble dye with polyethyleneimine, a water-soluble organic solvent and water. SOLUTION: This fluid is prepared by filtering and deforming a solution obtained by mixing under agitation 0.1-5wt.% magenta dye being a water-soluble dye (A) represented by the formula [wherein R1 to R3 are each H or an alkyl; X is phenylene, diphenylene, naphthylene or a moiety to give -NR3 -X-R3 N-being 1,4-piperazinylene; M is an alkali metal, a quat. ammonium ion or H; (n) is 1-5; (m) is 1-5; and (l) is 5-(m)], at most 50wt.%, based on component A, another water-soluble dye (B) optionally used to match the hue, 2-8wt.% polyethyleneimine (C) having a molecular weight of 200-10,000, 10-30wt.%, based on component C, water-soluble organic solvent (D) being a polyhydric alcohol having a hydroxyl functionality of 3, an alkylene glycol, an alkylene glycol lower alkyl ether and a mixture thereof an 60-90wt.% water (E).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ink jet recording ink used in an ink jet recording system.

[0002]

2. Description of the Related Art In general, as an ink used in an ink-jet recording system, one obtained by dissolving various water-soluble dyes in water or a medium comprising water and various organic solvents is known. Therefore, yellow, cyan, magenta, and black inks have been put to practical use. The ink used for such color image reproduction is required to be excellent in color reproducibility and the obtained image is excellent in water resistance and light resistance.

However, conventional magenta inks using a water-soluble magenta dye, which have excellent water reproducibility and magenta color reproducibility, are insufficient in water resistance and light resistance, and are excellent in water resistance and light resistance. However, the color reproducibility was inferior and was not sufficiently satisfactory. Further, such a magenta ink is required to be excellent in storage stability to withstand sudden changes in temperature, prevention of clogging of a discharge port of a head, prevention of mold, and the like.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a printed product having excellent water resistance, light fastness and color reproducibility, storage stability to withstand sudden changes in temperature, and prevention of clogging of a discharge port of a head. Another object of the present invention is to provide a water-soluble ink jet recording ink excellent in antifungal property and the like.

[0005]

According to the present invention, there is provided an ink jet recording ink containing at least a water-soluble dye, a water-soluble organic solvent and water, represented by the general formula (A):

Embedded image [Wherein, R ₁ , R ₂ and R ₃ represent a hydrogen atom or an alkyl group, and X represents a substituted or unsubstituted phenylene group, a substituted or unsubstituted diphenylene group, a substituted or unsubstituted naphthylene group, Or -NR ₃ -XR ₃ N- represents a 1,4-piperazinylene group, M represents an alkali metal, a quaternary ammonium or a hydrogen atom, n is an integer of 1 to 5, m is an integer of 1 to 5 And l represents 5-m. And when (R ₁ ) is two or more in the same aryl group, they may represent different groups or atoms (for example, hydrogen and methyl)]; And 2 to 8% by weight.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION As a coloring material (water-soluble dye) used in the ink of the present invention, a reactive dye represented by the general formula (A) is used. By using this dye as a magenta dye, excellent light fastness and water fastness can be obtained. This dye is contained in the ink in the range of 0.1 to 5% by weight, preferably 1 to 4% by weight. When the content of the dye is less than 0.1% by weight, the coloring of the ink becomes insufficient. When the content is more than 5% by weight, the dye in the ink tends to precipitate due to environmental change or the like, and the stability of the ink becomes poor. descend. If necessary to adjust the color tone, other water-soluble dyes (eg, acid dyes, direct dyes, basic dyes, reactive dyes, food dyes, etc.) are also represented by the general formula (A) of the present invention. You may use it in the range of 50 weight% or less with respect to the water-soluble dye used.

The magenta dyes of the general formula (A) suitable for the present invention include the following:

[0008]

Embedded image

[0009]

Embedded image

[0010] The ink of the present invention is also used in the ink based on the total weight of the ink for the purpose of improving the stability of the ink against a sudden change in temperature during storage, improving the ability to prevent clogging, and improving the antifungal property. 2-8% by weight, preferably 3-7%
It is preferred to contain polyethyleneimine by weight. If the amount of polyethyleneimine is less than 2% by weight, the above effect is insufficient, and if it is more than 8% by weight, the storage stability of the ink is reduced. Polyethyleneimine preferably has a molecular weight of 200 to 10,000, more preferably 250 to 2,000. As long as the molecular weight is in this range and water-soluble, it can be used regardless of the degree of branching. Examples of the polyethyleneimine that can be used in the present invention include “Epomin” (registered trademark) SP-series manufactured by Nippon Shokubai Co., Ltd., those obtained by reacting polyethyleneimine with ethylene oxide, those obtained by reacting alcohol or amine, and the like. And derivatives thereof.

The water-soluble organic solvent used in the ink of the present invention is preferably a polyhydric alcohol having 3 hydroxyl groups, a formula: OH (CxH _2x O) _y H (where x and y are 2 ≦ x and 2 (Indicating an integer satisfying ≦ x × y ≦ 6), selected from the group consisting of (mono, di, tri) alkylene glycols, lower alkyl ethers of the above (mono, di, tri) alkylene glycols, and mixtures thereof. Compounds.

Glycerin and the like are exemplified as the polyhydric alcohol having 3 hydroxyl groups.

As the (mono, di, tri) alkylene glycol, ethylene glycol, propylene glycol,
Examples thereof include monoalkylene glycols such as butylene glycol and hexylene glycol, dialkylene glycols such as diethylene glycol and dipropylene glycol, and trialkylene glycols such as triethylene glycol.

Examples of the lower alkyl ether of (mono, di, tri) alkylene glycol include ethylene glycol methyl ether, ethylene glycol ethyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol butyl ether, triethylene glycol butyl ether and the like.

When a polyhydric alcohol is used as the water-soluble organic solvent, it is contained in an amount of 1 to 20% by weight, preferably 6 to 14% by weight, based on the total amount of the ink, and when (mono, di, tri) alkylene glycol is used, Is 1 to 30% by weight, preferably 6 to 1% by weight based on the total weight of the ink.
It is added so as to be 4% by weight. The lower alkyl ether of (mono, di, tri) alkylene glycol is 1
-30% by weight, preferably 4-10% by weight.
The water-soluble organic solvent may be used alone or in combination of two or more.

The total content of polyethyleneimine and the above water-soluble organic solvents is preferably 10 to 30% by weight, more preferably 13 to 25% by weight.

As a solvent for the water-soluble dye of the present invention, water is used together with an organic solvent. The water content is 60% in the ink.
%, Preferably in the range of 70 to 90% by weight.

In addition to the above components, the following various auxiliary materials may be added to the ink of the present invention in order to improve the properties of the ink. If you want to improve the drying properties of the ink and improve the fixability of the ink,
For example, aliphatic alcohols having 1 to 5 carbon atoms, preferably 1 to 3 carbon atoms, such as methyl alcohol, ethyl alcohol, and isopropyl alcohol, are used. It is preferable that these aliphatic alcohols are contained in the ink in an amount of 0.1 to 15% by weight, preferably 1 to 6% by weight.

Further, in order to suppress the bleeding of the ink and to stabilize the ejection property from the nozzle of the ink jet recording apparatus, a surfactant is added to the ink to reduce the surface tension of the ink to 30 to 50 dyne / cm (liquid temperature of 25 ° C.). It is preferable to adjust so that Such a surfactant may be any of a nonionic, anionic and cationic surfactants. However, when an anionic or cationic surfactant is added, a salt is likely to be precipitated. Try to add ionic surfactant. Among the nonionic surfactants, an ethylene oxide adduct of acetylene glycol is particularly preferable from the viewpoint of improving the stability of the surface tension and the viscosity with respect to the temperature change of the ink. The surfactant is contained in the ink in an amount of 0.01 to 5% by weight, preferably 0.1 to 2% by weight.
May be contained within the range.

In order to improve the prevention of precipitation of crystals in the ink, an amphiphilic substance such as urea, amide, cyclic amide, alkanolamine and the like can be added to the ink. Particularly, an alkanolamine such as triethanolamine is preferable. Amphiphile is present in the ink at 0.0
The content may be 1 to 5% by weight, preferably 0.1 to 2% by weight.

Further, in order to improve the storage stability of the ink against a sudden change in temperature and suppress the dot variation, a mixture of NaOH and at least one of NaHCO ₃ or Na ₂ B ₄ O ₇ is used in an amount of 0.01 to 2%. % By weight, preferably 0.05 to 1% by weight. NaO in the mixture
The weight ratio of H to NaHCO ₃ or the like is preferably adjusted to 1: 2 to 1:50, preferably 1: 5 to 1:30.

Further, an alkali metal salt of ethylenediaminetetraacetic acid may be contained in order to prevent clogging of the ink at the nozzle discharge port and to improve the storage stability of the ink against environmental changes in temperature and humidity. Examples of the alkali metal salt of ethylenediaminetetraacetic acid include disodium salt of ethylenediaminetetraacetic acid, trisodium salt of ethylenediaminetetraacetic acid, tetrasodium salt of ethylenediaminetetraacetic acid and the like, and particularly preferred is tetrasodium salt of ethylenediaminetetraacetic acid. If the amount is too small, the effect of the addition is insufficient, and if the amount is too large, the above effect is reduced. Therefore, the addition amount is 0.01 to 2% by weight, preferably 0.05 to 1% by weight in the ink. .

In addition to the above-mentioned components, known additives may be added as necessary. Examples of such additives include a fungicide, a preservative, a pH adjuster, a chelating agent, and an oxygen absorbent. , Rust preventives, quenchers and the like.

The ink for ink-jet recording of the present invention comprises:
Any type of ink jet recording type printer can be applied. In particular, it can be suitably used in an ink jet recording apparatus using a piezo method, and furthermore, an ink diameter (ink amount) ejected by changing a flying voltage of the ink in the piezo method.
It can be particularly suitably used for an ink jet recording apparatus that performs gradation reproduction by changing the image quality.

Now, the present invention will be described in further detail with reference to Examples.

EXAMPLES The components of the following Examples and Comparative Examples were mixed and dissolved with sufficient stirring. After filtering the obtained stirring mixture, it was left still for 1 hour in a vacuum state to prepare a defoamed ink.

Example 1 Composition Composition ratio (% by weight) Water 70.9 Diethylene glycol 10.0 Triethylene glycol 7.0 Polyethyleneimine, "Epomin SP-006" (molecular weight: about 600, manufactured by Nippon Shokubai Co., Ltd.) 6.0 Water-soluble dye [M = Na in compound (3)] 2.6 Surfactant “Olfin-E1010” (manufactured by Nissin Chemical Industry Co., Ltd.) 0.8 Triethanolamine 0.2 NaHCO ₃ / NaOH (19 / 1) 0.2 Tetrasodium ethylenediaminetetraacetate 0.2 Fungicide: 1,2-benzoisothiazolin-3-one 0.1 Ethanol 2.0

Example 2 Composition Composition ratio (% by weight) Water 75.65 Diethylene glycol 10.0 Triethylene glycol butyl ether 7.0 Polyethyleneimine, "Epomin SP-006" 4.5 Water-soluble dye [in compound (3) 1.5 Surfactant “Olfin-E1010” (manufactured by Nissin Chemical Industry Co., Ltd.) 0.8 Triethanolamine 0.2 NaHCO ₃ / NaOH (19: 1) 0.2 Tetrasodium ethylenediaminetetraacetate 0.05 Antifungal agent: 1,2-benzisothiazolin-3-one 0.1

Example 3 Composition Composition ratio (% by weight) Water 72.0 Diethylene glycol 10.0 Triethylene glycol butyl ether 7.0 Polyethyleneimine, "Epomin SP-012" (molecular weight: about 1200, manufactured by Nippon Shokubai Co., Ltd.) 0 Water-soluble dye [M = Na in compound (3)] 2.5 Surfactant “Olphin-E1010” (manufactured by Nissin Chemical Industry Co., Ltd.) 0.8 Triethanolamine 0.2 Na ₂ B ₄ O ₇ / NaOH (19: 1) 0.2 Tetrasodium ethylenediaminetetraacetate 1.7 Fungicide: 1,2-benzoisothiazolin-3-one 0.1 Ethanol 1.5

Example 4 Composition Composition ratio (% by weight) Water 71.5 Diethylene glycol 10.0 Triethylene glycol butyl ether 7.0 Polyethyleneimine "Epomin SP-006" 4.5 Water-soluble dye [for compound (3) M = Na] 4.5 Surfactant “Olfin-E1010” (manufactured by Nissin Chemical Industry Co., Ltd.) 0.8 Triethanolamine 0.2 NaHCO ₃ / NaOH (19: 1) 0.2 Tetrasodium ethylenediaminetetraacetate 0 0.2 Antifungal agent: 1,2-benzisothiazolin-3-one 0.1 isopropyl alcohol 1.0

Example 5 Composition Composition ratio (% by weight) Water 79.6 Diethylene glycol 10.0 Triethylene glycol 4.0 Polyethyleneimine "Epomin SP-006" 2.0 Water-soluble dye [M in the compound (5) = Na] 2.5 Surfactant “Olfin-E1004” (manufactured by Nissin Chemical Industry Co., Ltd.) 1.2 Triethanolamine 0.2 NaHCO ₃ / NaOH (19: 1) 0.2 Tetrasodium ethylenediaminetetraacetate 0.2 2 Antifungal agent: 1,2-benzisothiazolin-3-one 0.1

Example 6 Composition Composition ratio (% by weight) Water 74.5 Diethylene glycol 10.0 Triethylene glycol butyl ether 4.0 Polyethyleneimine "Epomin SP-006" 7.5 Water-soluble dye [for compound (3) M = Na] 2.5 Surfactant “Olfin-E1010” (manufactured by Nissin Chemical Industry Co., Ltd.) 0.8 Triethanolamine 0.2 Na ₂ B ₄ O ₇ / NaOH (19: 1) 0.2 Ethylenediaminetetra Tetrasodium acetate 0.2 Fungicide: 1,2-benzisothiazolin-3-one 0.1

Example 7 Composition Composition ratio (% by weight) Water 73.1 Diethylene glycol 10.0 Triethylene glycol butyl ether 7.0 Polyethyleneimine "Epomin SP-006" 6.0 Water-soluble dye [for compound (3) M = Na] 2.5 Surfactant “Olfin-E1010” (manufactured by Nissin Chemical Industry Co., Ltd.) 0.8 Triethanolamine 0.2 NaHCO ₃ / NaOH (19: 1) 0.2 Tetrasodium ethylenediaminetetraacetate 0 .2

Example 8 Composition Composition ratio (% by weight) Water 81.7 Diethylene glycol 10.0 Polyethyleneimine "Epomin SP-006" 4.5 Water-soluble dye [M = Na in compound (3)] 2.5 Surfactant "polyether modified silicone oil TSF4452" (manufactured by Toshiba Silicone Co., Ltd.) 0.8 Triethanolamine 0.2 Ca (OH) ₂ / NaOH (19: 1) 0.2 Antifungal agent: 1,2-benzo Isothiazolin-3-one 0.1

Comparative Example 1 Composition Composition ratio (% by weight) Water 72.5 Diethylene glycol 10.0 Triethylene glycol butyl ether 7.0 Polyethyleneimine "Epomin SP-006" 4.5 Acid dye CI. 45100 2.5 Interface Activator “Olphin-E1010” (manufactured by Nissin Chemical Industry Co., Ltd.) 0.8 Triethanolamine 0.2 NaHCO ₃ / NaOH (19: 1) 0.2 Ethylenediaminetetraacetate tetrasodium 0.2 Fungicide: 1, 2-Benzoisothiazolin-3-one 0.1 Ethanol 2.0

Comparative Example 2 Composition Composition ratio (% by weight) Water 72.4 Diethylene glycol 10.0 Triethylene glycol 7.0 Polyethyleneimine "Epomin SP-006" 4.5 Direct dye CI Direct Red 227 2.6 surfactant "Olfin -E1010" (manufactured by Nissin chemical industry Co., Ltd.) 0.8 triethanolamine 0.2 NaHCO ₃ / NaOH (19: 1) 0.2 ethylenediaminetetraacetic acid tetrasodium 0.2 fungicide: 1 , 2-Benzoisothiazolin-3-one 0.1 Ethanol 2.0

Comparative Example 3 Composition Composition ratio (% by weight) Water 86.2 Diethylene glycol 10.0 Water-soluble dye [M = Na in compound (3)] 2.5 Surfactant "Polyether-modified silicone oil TSF4452" (Manufactured by Toshiba Silicone Co., Ltd.) 0.8 Triethanolamine 0.2 Ca (OH) ₂ / NaOH (19: 1) 0.2 Fungicide: 1,2-benzoisothiazolin-3-one 0.1

Comparative Example 4 Composition Composition ratio (% by weight) Water 77.8 Diethylene glycol 10.0 Polyethyleneimine "Epomin SP-012" 8.4 Water-soluble dye [M = Na in compound (3)] 2.5 Surfactant "polyether modified silicone oil TSF4452" (manufactured by Toshiba Silicone Co., Ltd.) 0.8 Triethanolamine 0.2 Ca (OH) ₂ / NaOH (19: 1) 0.2 Antifungal agent: 1,2-benzo Isothiazolin-3-one 0.1

25 of the inks of the obtained Examples and Comparative Examples
The surface tension at ℃, the viscosity and the pH, the storage stability against thermal shock, the antifungal test, and the temperature dependence of the surface tension and the viscosity and the water fastness and light fastness of the ink after printing were investigated. In addition, nozzle clogging was measured when the obtained ink was used for printing on an actual machine.
The measuring method is as follows:

1) Storage property against thermal shock The ink stored at 25 ° C. in a polyethylene bottle is kept at −20 ° C. and 50 ° C. for 1 hour, and then returned to 25 ° C. The thermal shock was given repeatedly for one week. Viscosity before and after shock (2
5 ° C.), and the rate of change was ranked as follows. Δ: Change rate 5% or less, Δ: Change rate 10% or less (no problem in practical use), ×: Change rate 10% or more (cannot be used)

2) Water resistance The ink is filled into an ink cartridge of an ink jet printer MJ-500 manufactured by Epson Corporation,
Printed on F paper. For printing, solid color printing was performed on a 5 × 5 mm area, air-dried for 24 hours, and then immersed in pure water for 10 minutes. After being taken out, it was further dried naturally, and the rate of change in concentration before and after the test was measured and calculated using a Sakura densitometer PDA65. Evaluation criteria for the rate of change are the same as in 1).

3) Light fastness The printed matter was irradiated for 200 hours under a sun lamp specified in ASTM D795 (American Material Testing Method), and the density change of the printed matter before and after irradiation was measured. The evaluation criterion for the change rate of the density is the same as in 1).

4) Nozzle clogging test: Using an actual machine, a color chart (20% coverage test chart, A4) of the same color as 100 inks was printed under high temperature and high humidity (35 ° C., 85% RH). It was printed on SF paper manufactured by the company. The nozzle clogging after printing was observed with a microscope. In addition, the nozzles were cleaned with a cleaning rubber blade provided on the MJ-500 for those to which foreign matter had adhered. Evaluation was performed as follows: 〇: No foreign matter adhered around the nozzle, and good use was possible. Δ: Foreign matter adhered around the nozzle, but foreign matter was removed by cleaning. There is no substantial problem in printing performance. X: Foreign matter was adhered around the nozzle, and the dots were thinned and fuzzy. Some nozzles are not recovered by cleaning, and cannot be used.

Incidentally, the evaluation that there is no practical problem of the above-mentioned “Δ” is the evaluation in the binary printing used in the embodiment. Therefore, even when the evaluation of △ is obtained, it is considered that there is a practical disadvantage when the dot diameter is reduced or when the dot diameter is changed to perform gradation printing.

5) Antifungal test A fungus specified in JIS Z 2911 (Testing method for mold resistance) was evaluated in the following procedure. Test strain Aspergillus niger IFO 4407 Chaelomium globosum IFO 6347 Cladosporium cladosporioides IFO 6348 Penicillium citrinum IFO 7784 Rhizopus siolonifer IFO 5411 Preparation of spore suspension
Spores (conidia) were suspended in sterilized 0.005% sodium dioctyl sulfosuccinate solution to give a single spore suspension. An equal amount of each single spore suspension was taken and mixed to obtain a mixed spore suspension. Test Procedure 2 ml of each ink was placed in a plastic petri dish, and 0.2 ml of the mixed spore suspension was inoculated. Cap 28
Stored at ± 2 ° C. and about 97% humidity. After 4 weeks of culture, the growth state of the hypha in the specimen was visually observed and observed with a microscope. 〇: No mold generation. Δ: Mold generation was less than 1/3 of the entire area. The result is equivalent to no change in the cartridge for two years, and there is no practical problem. X: Mold generation is 1/3 or more of the entire area. Not really usable.

6) Temperature Dependence The degree of change in surface tension and viscosity when the ink changes from 5 ° C. to 35 ° C. The rate of change was ranked as in 1). The results are shown in Tables 1 and 2.

[0046]

[Table 1]

[0047]

[Table 2]

[0048]

The ink of the present invention has good storage stability against a sudden temperature change, and has excellent water resistance and light resistance of printing. In addition, there is no clogging of the nozzles due to the use of the ink, and since the physical properties hardly change between 5 ° C. and 35 ° C., which is the temperature at which the ink is usually used, extremely high quality printing is possible. There is no mold during long-term storage.

Claims (6)

[Claims] 1. An ink jet recording ink containing at least a water-soluble dye, a water-soluble organic solvent and water,
General formula (A): [Wherein, R ₁ , R ₂ and R ₃ represent a hydrogen atom or an alkyl group, and X represents a substituted or unsubstituted phenylene group, a substituted or unsubstituted diphenylene group, a substituted or unsubstituted naphthylene group, or -NR ₃ -X-R ₃ N- represents a 1,4-piperazinylene group, M is an alkali metal, represents a quaternary ammonium or a hydrogen atom, n represents an integer of 1 to 5, m is from 1 to 5 Wherein l represents an integer and l represents 5-m], and 0.1 to 5% by weight of a water-soluble dye represented by the following formula: and 2 to 8% by weight of polyethyleneimine. 2. Polyethyleneimine having a molecular weight of 200 to 200.
The ink for inkjet recording according to claim 1, which has a molecular weight of 10,000. 3. The water-soluble organic solvent is a polyhydric alcohol having 3 hydroxyl groups, having the formula: HO (C _x H _2x O) _y H (where x and y are 2 ≦ x and 2 ≦ x × y ≦ (Mono, di, tri) alkylene glycols represented by the formula (1), lower alkyl ethers of the above (mono, di, tri) alkylene glycols, and mixtures thereof. The ink for inkjet recording according to claim 1 or 2. 4. The total content of the above-mentioned polyhydric alcohol, (mono, di, tri) alkylene glycol, (mono, di, tri) alkylene glycol lower alkyl ether and polyethyleneimine is 10 to 30 with respect to the total weight of the ink.
4. The ink jet recording ink according to claim 1, wherein the content is% by weight. 5. The ink jet recording ink according to claim 1, further comprising 0.1 to 15% by weight of an aliphatic alcohol having 1 to 5 carbon atoms based on the total weight of the ink. 6. The ink jet recording ink according to claim 1, further comprising 0.01 to 5% by weight of an alkanolamine based on the total weight of the ink.